JP2011059340A - New photosensitive resin composition and application of the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a photosensitive resin composition, aphotosensitive resin composition solution, a photosensitive resin film, a polyimide insulating film, and a printed wiring board with an insulating film which can be micro-fabricated owing to its photosensitivity, can be developed with a dilute aqueous alkali solution, can be cured at low temperatures (200°C or lower), exhibits flexibility, excels in electric-insulation reliability, resistance to the heat of soldering, organic solvent resistance and flame retardancy, is reduced in the warpage of the substrate after being cured and excellent in adhesion to a sealant, and avoids the bleed-out of a flame retardant component from a cured film. <P>SOLUTION: The photosensitive resin composition includes at least (A) a partially imidized polyimide precursor having an urethane bond, (B) photosensitive resin, (C) a photopolymerization initiator, and (D) a reactant flame retardant. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  Since this invention has photosensitivity, it can be finely processed, can be developed with a dilute alkaline aqueous solution, can be cured at a low temperature (200 ° C. or less), has high flexibility, electrical insulation reliability, and solder heat resistance. , Photosensitive resin composition excellent in organic solvent resistance and flame retardancy, small warping of the substrate after curing, excellent adhesion to the sealant, and suppressed bleeding out of the flame retardant component from the cured film The present invention relates to a photosensitive resin composition solution, a resin film, an insulating film, and a printed wiring board with an insulating film obtained therefrom.

  Polyimide resins are widely used in electrical and electronic applications because of their excellent heat resistance, electrical insulation reliability, chemical resistance, and mechanical properties. For example, it is used to form insulating films and protective coatings on semiconductor devices, base materials such as flexible circuit boards and integrated circuits, surface protective materials, and further, interlayer insulating films and protective films for fine circuits. .

  In particular, when used as a surface protection material for a flexible circuit board, a coverlay film obtained by applying an adhesive to a molded body such as a polyimide film has been used. When bonding this coverlay film on a flexible circuit board, there is a method in which an opening is provided in advance by a method such as punching in a terminal portion of a circuit or a joint portion with a component, and after aligning, a method of thermocompression bonding by a hot press or the like is used. It is common.

  However, it is difficult to provide a high-accuracy opening in a thin coverlay film, and since the alignment at the time of lamination is often performed manually, the positional accuracy is poor and the workability of the lamination is also poor. The cost was high.

  On the other hand, a liquid cover coat ink or the like may be used as a surface protective material for a circuit board. In particular, a liquid cover coat ink having a photosensitive function is preferably used when fine processing is required. Yes.

  As the liquid cover coat ink, for example, a photosensitive ink mainly composed of an epoxy resin or the like (generally also referred to as a solder resist) is used, but this ink is excellent in electrical insulation reliability as an insulating material, Since the mechanical properties such as flexibility are poor and the curing shrinkage is large, when the substrate is laminated on a thin and flexible circuit board such as a flexible circuit board, the warpage of the board becomes large and it is difficult to use it for a flexible circuit board.

  On the other hand, a polyimide-based photosensitive ink using a polyimide resin or a polyimide precursor has also been proposed. For example, a polyimide precursor having no photosensitivity per se, a polymerizable monomer or oligomer, and the polymerizable monomer or oligomer. A photosensitive heat-resistant resin composition comprising a polymerization initiator is proposed (for example, see Patent Document 1).

  In recent years, various proposals have been made that can exhibit flexibility and high electrical insulation reliability as liquid cover coat ink for flexible circuit boards.

  For example, a photosensitive resin composition containing a terminal half-esterified imidosiloxane oligomer has been proposed (see, for example, Patent Documents 2 to 3).

  Also proposed is a photosensitive resin composition containing a photopolymerizable unsaturated compound including a urethane compound having an ethylenically unsaturated bond, which is excellent in flexibility, photocurability, insulation and flame retardancy and can be alkali-developed. (For example, refer to Patent Document 4).

  In addition, a phosphorus-containing alkali-soluble resin and a phosphorus-containing photopolymerizable compound that are excellent in all of alkali developability, flame retardancy, and coating properties, and can efficiently form a cured film having sufficient flame retardancy with high resolution. The photosensitive resin composition containing is proposed (for example, refer patent document 5).

Japanese Patent Laid-Open No. 4-18450 JP 2000-212446 A JP 2001-215702 A JP 2000-241969 A JP 2007-304542 A

  However, the photosensitive heat-resistant resin comprising a polyimide precursor that does not have photosensitivity per se described in Patent Document 1, a polymerizable monomer or oligomer, and a polymerization initiator of the polymerizable monomer or oligomer. When the composition is used as a circuit board material, since the polyimide precursor has a large molecular weight and low solvent solubility, when the polyimide precursor solution is used, the concentration of the solute cannot be adjusted to a high concentration. When forming a coating film, it is necessary to volatilize a large amount of solvent, which is a problem of poor productivity. Further, when performing fine processing by patterning, it is necessary to develop with N-methyl-2-pyrrolidone, then rinse with ethyl alcohol, and further imidize, and the heating temperature exceeds 250 to 300 ° C. Since it is necessary to imidize at a temperature, for example, when used for a protective film such as a flexible circuit board, there is a limitation that an organic solvent is required for the processing process, and the circuit board material cannot withstand high temperatures. There was a problem such as.

  Moreover, when the cured film formed from the resin composition containing the terminal half-esterified imide siloxane oligomer described in Patent Documents 2 to 3 is used as a circuit board material, impurities contained in the siloxane diamine are cured film. There is also a problem of bleeding out from the surface and inducing a malfunction of the semiconductor, a problem of poor wettability on the surface of the obtained cured film, and poor adhesion with various sealants.

  When the cured film formed from the photosensitive resin composition described in Patent Documents 4 to 5 above is used as a surface protective film for a flexible circuit board, the photosensitive resin composition contains a polyimide resin or a polyimide precursor. Compared with the case of using a cured film formed from the above, it has poor electrical insulation reliability and heat resistance under high temperature and high humidity, and in Patent Document 4 described above, a condensed phosphate ester type is used for the purpose of imparting flame retardancy. Addition-type flame retardants are added, and hydrolysis of this flame retardant significantly reduces the electrical insulation reliability. In addition, condensed phosphate ester-based additive flame retardants bleed out and organic solvents from the cured film There was a problem such as elution into a gold plating bath.

  In addition, when a cured film formed from the photosensitive resin composition described in Patent Document 5 is used as a surface protective film for a flexible circuit board, the photosensitive resin composition contains a polyimide resin or a polyimide precursor. Compared with the case where the cured film formed from the above is used, there is a problem that the cured film becomes brittle and lacks flexibility, the curing shrinkage of the cured film increases, and the flexible circuit board largely warps.

  In view of the above situation, the problem of the present invention is that it has photosensitivity, can be finely processed, can be developed with a dilute alkaline aqueous solution, can be cured at a low temperature (200 ° C. or less), has high flexibility, Excellent insulation reliability, solder heat resistance, organic solvent resistance, flame retardancy, low warpage of cured substrate, excellent adhesion to sealant, and bleed out of flame retardant components from cured film An object of the present invention is to provide a photosensitive resin composition, a photosensitive resin composition solution, a photosensitive resin film, a polyimide insulating film, and a printed wiring board with an insulating film.

  As a result of intensive studies to solve the above problems, the present inventors have at least (A) a polyimide precursor having a partially imidized urethane bond, (B) a photosensitive resin, (C) a photopolymerization initiator, (D ) Photosensitive resin composition characterized by containing a reactive flame retardant, because it has photosensitivity, it can be finely processed, can be developed with dilute alkaline aqueous solution, and can be cured at low temperature (200 ° C or less) Excellent flexibility, electrical insulation reliability, solder heat resistance, organic solvent resistance, flame resistance, low warpage of the substrate after curing, excellent adhesion to the sealant, and from the cured film It was found that a photosensitive resin composition in which no bleed-out of the flame retardant component occurs can be obtained.

  That is, the photosensitive resin composition according to the present invention comprises at least (A) a polyimide precursor having a partially imidized urethane bond, (B) a photosensitive resin, (C) a photopolymerization initiator, and (D) reactivity. It is characterized by containing a flame retardant.

  In the photosensitive resin composition concerning this invention, it is preferable that the said (A) polyimide precursor contains a polycarbonate frame | skeleton further.

  In the photosensitive resin composition according to the present invention, the (A) polyimide precursor is at least (a) a diol compound represented by the following general formula (1) and (b) represented by the following general formula (2). A terminal isocyanate compound by reacting with a diisocyanate compound to be synthesized, and then (c) a tetracarboxylic dianhydride represented by the following general formula (3) is reacted to synthesize a terminal acid anhydride urethane imide oligomer, (D) It is preferably obtained by addition reaction of a diamine represented by the following general formula (4).

(In the formula, R represents a divalent organic group.)

(In the formula, X represents a divalent organic group.)

(In the formula, Y represents a tetravalent organic group.)

(In the formula, Z represents a divalent organic group.)

  Moreover, in the photosensitive resin composition concerning this invention, it is preferable that the said (a) diol compound contains the polycarbonate diol shown by following General formula (5) at least.

(In the formula, plural R _{1 s} each independently represent a divalent organic group, and m is an integer of 1 to 20.)

  Moreover, in the photosensitive resin composition concerning this invention, it is preferable that the said (A) polyimide precursor contains a carboxyl group further in a side chain.

  In the photosensitive resin composition according to the present invention, (A) a polyimide precursor having a partially imidized urethane bond, (B) a photosensitive resin, and (C) a photopolymerization initiator are (A) a partial imide. (B) 10 to 200 parts by weight of the photosensitive resin and (C) 0.1 to 50 parts by weight of the photopolymerization initiator with respect to 100 parts by weight of the solid content of the polyimide precursor having a urethane bond. It is preferable that they are blended so that

  Moreover, in the photosensitive resin composition concerning this invention, it is preferable that the said (D) reactive flame retardant is a phosphorus compound which has an at least 1 photosensitive group in a molecule | numerator.

  Moreover, in the photosensitive resin composition concerning this invention, it is preferable that said photosensitive group is a (meth) acryloyl group.

  Moreover, in the photosensitive resin composition concerning this invention, the mixing | blending ratio of the said (D) reactive flame retardant is (A) the polyimide precursor which has the urethane bond which carried out the partial imidization, (B) photosensitive resin, ( C) It is preferable to mix | blend so that it may become 1-100 weight part with respect to 100 weight part of solid content which totaled the photoinitiator.

  Moreover, in the photosensitive resin composition concerning this invention, it is preferable to contain (E) thermosetting resin further.

  Moreover, in the photosensitive resin composition concerning this invention, the compounding ratio of the said (E) thermosetting resin is (A) the polyimide precursor which has the urethane group which was partially imidized, (B) photosensitive resin, ( C) It is preferable to mix | blend so that it may become 0.5-100 weight part with respect to 100 weight part of solid content which totaled the photoinitiator.

  Moreover, the photosensitive resin composition solution concerning this invention is a thing obtained by melt | dissolving the said photosensitive resin composition in the organic solvent.

  Moreover, the resin film concerning this invention is obtained by drying, after apply | coating the said photosensitive resin composition solution to a base-material surface.

  The insulating film according to the present invention is obtained by curing the resin film.

  The printed wiring board with an insulating film according to the present invention is obtained by coating the insulating film on the printed wiring board.

  As described above, the photosensitive resin composition of the present invention comprises at least (A) a polyimide precursor having a partially imidized urethane bond, (B) a photosensitive resin, (C) a photopolymerization initiator, and (D). Since it has a structure containing a reactive flame retardant, the cured film obtained from the photosensitive resin composition of the present invention is rich in flexibility, electrical insulation reliability, solder heat resistance, organic solvent resistance, flame resistance In addition to having excellent physical properties, the warpage after curing is small, the adhesiveness with the sealant is excellent, and the bleed-out of the flame retardant component from the cured film is suppressed. Therefore, the photosensitive resin composition of the present invention can be used for protective films of various circuit boards and exhibits excellent effects.

Schematic diagram measuring the amount of warping of the film

  Hereinafter, the present invention will be described in detail.

<Photosensitive resin composition>
The photosensitive resin composition of the present invention comprises at least (A) a polyimide precursor having a partially imidized urethane bond, (B) a photosensitive resin, (C) a photopolymerization initiator, and (D) a reaction. The flame retardant should just be contained.

  In addition, about the polyimide precursor which has the urethane bond (A) partially imidized in the photosensitive resin composition of this invention, although the polyimide precursor containing a polycarbonate frame | skeleton is used more preferably, it is limited to this. It is not a thing.

  The photosensitive resin composition of the present invention comprises (A) a polyimide precursor having a partially imidized urethane bond, (B) a photosensitive resin, (C) a photopolymerization initiator, and (D) a reaction. In addition to the flame retardant, (E) a thermosetting resin may be further contained.

  Here, at least (A) a polyimide precursor having a partially imidized urethane bond, (B) a photosensitive resin, (C) a photopolymerization initiator, and (D) a reactive flame retardant. The present inventors have found that the photosensitive resin composition to be contained is excellent in various properties, but this is presumed to be due to the following reasons. In other words, (A) a polyimide precursor having a partially imidized urethane bond has an imide skeleton and a urethane bond in the molecule, and therefore heat resistance and electrical insulation reliability derived from the imide skeleton, and chemical resistance derived from the urethane bond. In addition, since the polymer has a carboxyl group in the molecule, it becomes soluble in a developer typified by a dilute alkaline aqueous solution and can be finely processed by exposure and development. Among them, a polyimide precursor having a partially imidized urethane bond obtained by using a polycarbonate diol surprisingly has a large amount of carboxyl groups in the molecule because of the excellent chemical resistance of the polycarbonate skeleton. Nevertheless, the exposed part (cured part) has no damage such as swelling or dissolution of the coating film by the developer, and the unexposed part (uncured part) is short because it contains many carboxyl groups in the molecule. It dissolves in the development time, and a pattern with very good resolution can be obtained.

  In addition, (A) a polyimide precursor having a partially imidized urethane bond has a partially imide skeleton, so that it is very stable even when stored at room temperature for a long time in a solution state. Since it has an acid skeleton, it has excellent solubility in a solvent.

  In addition, the imidization reaction for cyclizing the amic acid skeleton proceeds at a temperature of 200 ° C. or lower and about 150 to 170 ° C. This is a urethane bond and raw material diol contained in a polyimide precursor having a partially imidized urethane bond. Due to the flexibility derived from the components and the high mobility of the molecular skeleton, molecular motion actively occurs even in the curing temperature range of about 150 to 170 ° C., and the imidization reaction proceeds to cyclize the amic acid skeleton. I guess.

  In addition, since the molecular skeleton does not contain a siloxane skeleton, the resulting cured film surface has good wettability, not only very good adhesion to various members, but also derived from the siloxane component from the cured film Therefore, when a cured film is used as an insulating film of a printed wiring board, the semiconductor does not malfunction.

  The reactive flame retardant as component (D) reacts and is incorporated into the composition while forming a three-dimensional network structure in the step of curing the photosensitive resin composition. The cured film obtained from this product has excellent heat resistance and chemical resistance, excellent electrical insulation reliability under high temperature and high humidity, no bleed out of flame retardant components from the cured film, and the cured film surface is not sticky Not only is the pencil hardness high, but also surprisingly, a cured film with high flexibility is obtained, and the cured film has a very small curing shrinkage. For example, it can be used as a surface insulating film of a flexible printed circuit board. If it occurs, the flexible printed wiring board is hardly warped. This is excellent in flexibility of a cured film obtained by imidizing a polyimide precursor having a partially imidized urethane bond, and a molecular chain in which a polyimide precursor having a partially imidized urethane bond is imidized. Because the flame retardant enters the molecular chain in the mesh gap, the molecular chain network imidized with the polyimide precursor having a partially imidized urethane bond plays a role in relieving stress generated during curing I guess that. Further, the photosensitive resin composition of the present invention can exhibit a sufficient flame retardant effect even with a low addition amount of the component (D) alone, but this is because aromatic and imide groups are present in the cured film. Since it contains, the thermal decomposition start temperature of a cured film is high, and since it contains many nitrogen atoms derived from a urethane bond and an imide group, it is estimated that it is because it is excellent in the combustion suppression effect at the time of combustion.

  Hereinafter, (A) a polyimide precursor having a partially imidized urethane bond, (B) a photosensitive resin, (C) a photopolymerization initiator, (D) a reactive flame retardant, (E) a thermosetting resin, etc. And the mixing method of (A) to (D) or (A) to (E) will be described.

<(A) Polyimide precursor having a partially imidized urethane bond>
The polyimide precursor having a partially imidized urethane bond used in the present invention is a number average molecular weight having at least a polyamic acid structure and a urethane structure inside the molecular chain, and the imide ring is partially closed. Is a polyimide precursor in terms of polyethylene glycol of 1000 or more, more preferably 5000 or more. With such a structure, it is possible to increase the concentration of the solution when dissolved in a solvent, and it is difficult to cause a change with time in viscosity (molecular weight change) of the solution when stored at room temperature. It becomes possible.

  More specifically, in the present invention, a polyimide precursor having a partially imidized urethane bond is represented by the following general formula (6).

(In the formula, R and X each independently represent a divalent organic group, and m represents an integer of 1 or more.)
It has at least one repeating unit having a urethane bond represented by the following general formula (7)

(Wherein R ² independently represents a divalent organic group, Y independently represents a tetravalent organic group, and n represents an integer of 1 or more) and General formula (8)

(In the formula, each Z independently represents a divalent organic group, each Y independently represents a tetravalent organic group, and p represents an integer of 1 or more.)
It is a compound which has a polyamic acid structure shown by these.

  The number average molecular weight of the polyimide precursor having a partially imidized urethane bond of the present invention is preferably 1,000 or more and 1,000,000 or less, more preferably 5,000 or more and 500, in terms of polyethylene glycol. 1,000 or less, particularly preferably 10,000 or more and 200,000 or less. By controlling the reaction to a number average molecular weight within the above range, the concentration of the solution when dissolved in a solvent can be increased, and the viscosity of the solution can be kept low, which is preferable.

  In addition, since the polyimide precursor having a partially imidized urethane bond of the present invention has a flexible urethane bond in the structure, the imidization reaction for cyclizing the amic acid skeleton can proceed at a low temperature of 200 ° C. or lower. Is possible. Moreover, the cured film formed using this is excellent in the softness | flexibility and the wettability of the cured film surface, and adhesiveness with various sealing agents is favorable.

  Further, the polyimide precursor having a partially imidized urethane bond of the present invention preferably contains a polycarbonate skeleton in the structure. By adopting such a structure, it becomes possible to further improve the heat resistance, flexibility, water resistance, chemical resistance, and electrical insulation reliability under high temperature and high humidity of the obtained cured film.

  The polyimide precursor having a partially imidized urethane bond used in the present invention is not particularly limited as long as it has the above structure, but more preferably at least (a) the following general Formula (1)

(In the formula, R represents a divalent organic group.)
(B) the following general formula (2)

(In the formula, X represents a divalent organic group.)
The terminal isocyanate compound is synthesized by reacting with the diisocyanate compound represented by formula (3), and then (c) the following general formula (3)

(In the formula, Y represents a tetravalent organic group.)
The terminal acid anhydride urethane imide oligomer is synthesized by reacting the tetracarboxylic dianhydride represented by the general formula (4).

(In the formula, Z represents a divalent organic group.)
It is obtained by reacting a diamine compound represented by

<(A) Diol compound>
The (a) diol compound used in the present invention is a branched or straight-chain compound having two hydroxyl groups in the molecule represented by the general formula (1).

(Wherein R represents a divalent organic group).

  (A) The diol compound is not particularly limited as long as it has the above structure. For example, ethylene glycol, diethylene glycol, propylene glycol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, neo Pentyl glycol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, 1,8-octanediol, 2-methyl-1,8-octanediol, 1,9-nonanediol, 1,10-decane Diols, alkylene diols such as 1,4-cyclohexanediol and 1,4-cyclohexanedimethanol, dimethylolpropionic acid (2,2-bis (hydroxymethyl) propionic acid), dimethylolbutanoic acid (2,2-bis ( Hydroxymethyl) butanoic acid), 2,3-dihydroxybenzoic acid, 2 Carboxyl group-containing diols such as 4-dihydroxybenzoic acid, 2,5-dihydroxybenzoic acid, 2,6-dihydroxybenzoic acid, 3,4-dihydroxybenzoic acid, 3,5-dihydroxybenzoic acid, polyethylene glycol, polypropylene glycol, Polytetramethylene glycol, polyoxyalkylene diols such as random copolymers of tetramethylene glycol and neopentyl glycol, polyester diols obtained by reacting polyhydric alcohols with polybasic acids, polycarbonate diols having a carbonate skeleton, γ -Polycaprolactone diol obtained by ring-opening addition reaction of lactones such as butyl lactone, ε-caprolactone, δ-valerolactone, bisphenol A, ethylene oxide adduct of bisphenol A, bisphenol Examples include a propylene oxide adduct of Nord A, hydrogenated bisphenol A, an ethylene oxide adduct of hydrogenated bisphenol A, a propylene oxide adduct of hydrogenated bisphenol A, and these can be used alone or in combination of two or more. .

  (A) As a diol compound, following General formula (5)

(In the formula, plural R _{1 s} each independently represent a divalent organic group, and m is an integer of 1 to 20.)
It is particularly preferable to use a polycarbonate diol represented by This is preferable in that the heat resistance, flexibility, water resistance, chemical resistance, and electrical insulation reliability under high temperature and high humidity of the obtained cured film can be further improved.

  More specifically, examples of the polycarbonate diol include trade names PCDL T-4671, T-4672, T-4691, T-4692, T-5650J, T-5651, T-5651 manufactured by Asahi Kasei Chemicals Corporation. , T-6001, T-6002, Daicel Chemical Industries, Ltd. Product Name Plaxel CD CD205, CD205PL, CD205HL, CD210, CD210PL, CD210HL, CD220, CD220PL, CD220HL, Kuraray Co., Ltd. product name Kuraray Polyol C-1015N , C-1050, C-1065N, C-1090, C-2015N, C-2065N, C-2090, Nippon Polyurethane Industry Co., Ltd., trade names NIPPOLAN 981, 980R, 982R These can be used alone or in combinations of two or more. The number average molecular weight of the polycarbonate diol is preferably 500 to 5000, more preferably 750 to 2500, and particularly preferably 1000 to 2000 in terms of polystyrene. When the number average molecular weight of the polycarbonate diol is within the above range, it is preferable in that the chemical resistance and flexibility of the obtained cured film can be improved. When the number average molecular weight is less than 500, the flexibility of the resulting cured film may be reduced. When the number average molecular weight is 5000 or more, the solvent solubility of the polyimide precursor having a partially imidized urethane bond is reduced. There is a case.

  More preferably, by combining the polycarbonate diol and the carboxyl group-containing diol, a carboxyl group can be introduced into the side chain of the polyimide precursor having a partially imidized urethane bond. Thereby, the branch point of the main chain of the polyimide precursor having a partially imidized urethane bond increases, the crystallinity is lowered, and the solvent solubility of the polyimide precursor having a partially imidized urethane bond is improved. It is preferable in that

<(B) Diisocyanate compound>
The (b) diisocyanate compound used in the present invention is a compound having two isocyanate groups in the molecule, represented by the general formula (2).

(Wherein X represents a divalent organic group).

  Examples of the (b) diisocyanate compound include diphenylmethane-2,4'-diisocyanate, 3,2'- or 3,3'- or 4,2'- or 4,3'- or 5,2'- or 5,3'- or 6,2'- or 6,3'-dimethyldiphenylmethane-2,4'-diisocyanate, 3,2'- or 3,3'- or 4,2'- or 4,3'- Or 5,2'- or 5,3'- or 6,2'- or 6,3'-diethyldiphenylmethane-2,4'-diisocyanate, 3,2'- or 3,3'- or 4,2 ' -Or 4,3'- or 5,2'- or 5,3'- or 6,2'- or 6,3'-dimethoxydiphenylmethane-2,4'-diisocyanate, diphenylmethane-4,4'-diisocyanate, Diphenylmethane-3,3'-diiso Anate, diphenylmethane-3,4'-diisocyanate, diphenyl ether-4,4'-diisocyanate, benzophenone-4,4'-diisocyanate, diphenylsulfone-4,4'-diisocyanate, tolylene-2,4-diisocyanate, tolylene-2 , 6-diisocyanate, m-xylylene diisocyanate, p-xylylene diisocyanate, naphthalene-2,6-diisocyanate, 4,4 '-[2,2-bis (4-phenoxyphenyl) propane] diisocyanate Compounds, hydrogenated diphenylmethane diisocyanate, hydrogenated xylylene diisocyanate, isophorone diisocyanate, norbornene diisocyanate, etc., hexamethylene diisocyanate Sulfonate, trimethyl hexamethylene diisocyanate, aliphatic diisocyanate compounds and the like such as lysine diisocyanate, and these may be used alone or in combinations of two or more. Use of these is preferable for increasing the heat resistance of the resulting cured film. Moreover, you may use what was stabilized with the blocking agent required in order to avoid a change over time. Such blocking agents include alcohol, phenol, oxime and the like, but are not particularly limited.

  (B) As the diisocyanate compound, diphenylmethane-4,4'-diisocyanate, diphenylmethane-3,3'-diisocyanate, diphenylmethane-3,4'-diisocyanate, tolylene-2,4-diisocyanate, tolylene-2,6-diisocyanate It is particularly preferable to use norbornene diisocyanate. Thereby, it is preferable at the point which can improve the heat resistance of the cured film obtained, and water resistance further.

  In order to improve the developability of the photosensitive resin composition, (b) tolylene-2,6-diisocyanate, tolylene-2,4-diisocyanate and 1,6-hexamethylene diisocyanate are suitable as the diisocyanate compound. Used for.

<Method for synthesizing terminal isocyanate compound>
The method for synthesizing a terminal isocyanate compound obtained by reacting (a) a diol compound and (b) a diisocyanate compound used in the present invention is the ratio of the number of hydroxyl groups to the number of isocyanate groups. Is reacted in a solvent-free or organic solvent such that isocyanate group / hydroxyl group = 1 or more and 2.10 or less, more preferably 1.10 or more and 2.10 or less, and further preferably 1.90 or more and 2.10 or less. Can be obtained.

  When two or more types of (a) diol compounds are used, the reaction with (b) diisocyanate compound may be carried out after mixing two or more types of (a) diol compounds. You may react a compound and (b) diisocyanate compound separately. Moreover, after reacting (a) diol compound and (b) diisocyanate compound, the obtained terminal isocyanate compound is further reacted with another (a) diol compound, and this is further reacted with (b) diisocyanate compound. May be. The same applies when two or more types of (b) diisocyanate compounds are used. In this way, a desired terminal isocyanate compound can be produced.

  The reaction temperature between (a) and (b) is preferably 40 to 160 ° C, more preferably 60 to 150 ° C. If it is less than 40 ° C., the reaction time becomes too long. If it exceeds 160 ° C., a three-dimensional reaction occurs during the reaction and gelation tends to occur. The reaction time can be appropriately selected depending on the scale of the batch and the reaction conditions employed. If necessary, the reaction may be performed in the presence of a catalyst such as a tertiary amine, an alkali metal, an alkaline earth metal, a metal such as tin, zinc, titanium, cobalt, or a metalloid compound.

  The above reaction can be carried out in the absence of a solvent. However, in order to control the reaction, it is desirable to carry out the reaction in an organic solvent system. For example, examples of the organic solvent include sulfoxide solvents such as dimethyl sulfoxide and diethyl sulfoxide, N , N-dimethylformamide, formamide solvents such as N, N-diethylformamide, N, N-dimethylacetamide, acetamide solvents such as N, N-diethylacetamide, N-methyl-2-pyrrolidone, N-vinyl-2 Examples include pyrrolidone solvents such as -pyrrolidone, hexamethylphosphoramide, and γ-butyrolactone. Further, if necessary, these organic polar solvents can be used in combination with an aromatic hydrocarbon such as xylene or toluene.

  Furthermore, for example, methyl monoglyme (1,2-dimethoxyethane), methyldiglyme (bis (2-methoxyether) ether), methyltriglyme (1,2-bis (2-methoxyethoxy) ethane), methyltetraglyme (Bis [2- (2-methoxyethoxyethyl)] ether), ethyl monoglyme (1,2-diethoxyethane), ethyldiglyme (bis (2-ethoxyethyl) ether), butyldiglyme (bis (2 Symmetric glycol diethers such as -butoxyethyl) ether), methyl acetate, ethyl acetate, isopropyl acetate, n-propyl acetate, butyl acetate, propylene glycol monomethyl ether acetate, ethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether Cetate (also known as carbitol acetate, 2- (2-butoxyethoxy) ethyl acetate), diethylene glycol monobutyl ether acetate, 3-methoxybutyl acetate, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, dipropylene glycol methyl ether Acetates such as acetate, propylene glycol diacetate, 1,3-butylene glycol diacetate, dipropylene glycol methyl ether, tripropylene glycol methyl ether, propylene glycol n-propyl ether, dipropylene glycol n-propyl ether, propylene glycol n-butyl ether, dipropylene glycol n-butyl ether, tripylene glycol n Propyl ether, propylene glycol phenyl ether, dipropylene glycol dimethyl ether, 1,3-dioxolane, ethylene glycol monobutyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, a solvent may be used ethers such as ethyl ether also ethylene glycol. Of these, symmetrical glycol diethers are preferably used because side reactions are unlikely to occur.

  The amount of solvent used in the reaction is desirably such that the solute weight concentration in the reaction solution, that is, the solution concentration is 5% by weight or more and 90% by weight or less. The solute weight concentration in the reaction solution is more preferably 10 wt% or more and 80 wt% or less. When the solution concentration is 5% or less, the polymerization reaction is difficult to occur, the reaction rate is lowered, and a desired structural substance may not be obtained.

  Moreover, the terminal isocyanate compound obtained by the said reaction can also block the isocyanate group of the resin terminal after completion | finish of synthesis | combination with blocking agents, such as alcohol, lactams, and oximes.

<Terminal acid anhydride urethane imide oligomer>
The terminal acid anhydride urethane imide oligomer used in the present invention can be obtained by reacting the terminal isocyanate compound obtained as described above with tetracarboxylic dianhydride. At this time, the blending amount of the terminal isocyanate compound and the tetracarboxylic dianhydride is preferably such that the ratio of the number of isocyanate groups to the number of acid dianhydride groups is acid dianhydride group / isocyanate group = 2.10 or less, It is more preferably 1.10 or more and 2.10 or less, and further preferably 1.90 or more and 2.10 or less. Moreover, the solvent used at the time of the synthesis | combination of the said terminal isocyanate compound may be used for reaction of a terminal isocyanate compound and tetracarboxylic dianhydride as it is, and also said solvent can be added in addition.

<Tetracarboxylic dianhydride>
Examples of the tetracarboxylic dianhydride used for the synthesis of the polyimide precursor having a partially imidized urethane bond in the present invention include 3,3 ′, 4,4′-benzophenone tetracarboxylic dianhydride, pyromellitic, for example. Acid dianhydride, 3,3 ′, 4,4′-oxydiphthalic dianhydride, 2,2-bis [4- (3,4-dicarboxyphenoxy) phenyl] propane dianhydride, 2,2-bis (4-hydroxyphenyl) propanedibenzoate-3,3 ′, 4,4′-tetracarboxylic dianhydride, 3,3 ′, 4,4′-diphenylsulfone tetracarboxylic dianhydride, 3,3 ′ , 4,4′-biphenyltetracarboxylic dianhydride, 2,3,3 ′, 4-biphenyltetracarboxylic dianhydride, 5- (2,5-dioxotetrahydro-3-furanyl) -3-methyl -3- It can be used tetracarboxylic acid dianhydride such as Rohekisen 1,2-dicarboxylic anhydride.

  More preferably, the tetracarboxylic dianhydride used in the synthesis of the polyimide precursor having a partially imidized urethane bond is 2,2-bis [4- (3,4-dicarboxyphenoxy) phenyl] propane-2. Anhydride, 3,3 ′, 4,4′-diphenylsulfonetetracarboxylic dianhydride, 3,3 ′, 4,4′-oxydiphthalic dianhydride. The use of these can improve the solubility of the polyimide precursor having a partially imidized urethane bond obtained in an organic solvent, and is preferable for improving the chemical resistance of the resulting cured film.

  The tetracarboxylic dianhydride is 2,2-bis [4- (3,4-dicarboxyphenoxy) phenyl] propane dianhydride or 5- (2,5-dioxotetrahydro-3-furanyl). It is more preferable to use -3-methyl-3-cyclohexene-1,2-dicarboxylic acid anhydride from the viewpoint of compatibility with other materials in the photosensitive resin composition.

  The amount of the tetracarboxylic dianhydride used in the present invention is as follows when the amount of the polyol (more specifically, the diol compound) used in the production of the terminal isocyanate compound is 1 mol. When used in a proportion of 50 mol or more and 4.00 mol or less, the polyimide precursor having a partially imidized urethane bond is preferably flexible, and the particularly preferred range of use is 1.70 mol or more and 3. It is to be used at a ratio of 00 mol or less. This is preferable because tetracarboxylic dianhydride that does not contribute to the reaction can be reduced.

<Method for producing terminal acid anhydride urethane imide oligomer>
Various methods are mentioned as a reaction method of the terminal isocyanate compound and tetracarboxylic dianhydride in the method for producing a polyimide precursor having a partially imidized urethane bond. The typical method is illustrated below. However, any method may be used as long as tetracarboxylic dianhydride is arranged at the terminal.

  Method 1: A terminal isocyanate compound is gradually added to a solution in which tetracarboxylic dianhydride is dispersed or dissolved in an organic solvent. The reaction temperature at this time is 100 ° C. or higher and 300 ° C. or lower, more preferably 140 ° C. or higher and 250 ° C. or lower. It is preferred that the reaction occurs and imidization proceeds at the same time when the terminal isocyanate compound is added by heating to such a temperature. However, after the terminal isocyanate compound and tetracarboxylic dianhydride are completely dissolved at a low temperature, a method of imidizing by heating to a high temperature may be used.

  Method 2: A terminal isocyanate compound is gradually added and dissolved in a solution in which tetracarboxylic dianhydride is dispersed or dissolved in an organic solvent. Imidization can be carried out by drawing a vacuum while heating and drying a uniformly dissolved solution heated to 100 ° C. or higher and 250 ° C. or lower.

<Method for synthesizing polyimide precursor having partially imidized urethane bond>
A polyimide precursor having a partially imidized urethane bond can be obtained by reacting a terminal amino acid anhydride urethane imide oligomer obtained by the above method with a diamino compound.

  The diamino compound used in the present invention is a compound having two or more amino groups. Preferably, the general formula (4)

(In the formula, Z represents a divalent organic group.)
Is an aromatic diamine.

  More specific examples of the diamino compound include m-phenylenediamine, o-phenylenediamine, p-phenylenediamine, m-aminobenzylamine, p-aminobenzylamine, bis (3-aminophenyl) sulfide, (3 -Aminophenyl) (4-aminophenyl) sulfide, bis (4-aminophenyl) sulfide, bis (3-aminophenyl) sulfoxide, (3-aminophenyl) (4-aminophenyl) sulfoxide, bis (4-aminophenyl) ) Sulphoxide, bis (3-aminophenyl) sulfone, (3-aminophenyl) (4-aminophenyl) sulfone, bis (4-aminophenyl) sulfone, 3,4'-diaminobenzophenone, 4,4'-diaminobenzophenone 3,3′-diaminobenzophenone, , 3′-diaminodiphenylmethane, 3,4′-diaminodiphenylmethane, 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenylether, 3,3′-diaminodiphenylether, 3,4′-diaminodiphenylether, bis [4 -(3-aminophenoxy) phenyl] sulfoxide, bis [4- (aminophenoxy) phenyl] sulfoxide, (4-aminophenoxyphenyl) (3-aminophenoxyphenyl) phenyl] sulfoxide, bis [4- (3-aminophenoxy) ) Phenyl] sulfone, bis [4- (4-aminophenoxy) phenyl] sulfone, (4-aminophenoxyphenyl) (3-aminophenoxyphenyl) phenyl] sulfone, bis [4- (3-aminophenoxy) phenyl] sulfi Bis [4- (aminophenoxy) phenyl] sulfide, (4-aminophenoxyphenyl) (3-aminophenoxyphenyl) phenyl] sulfide, 3,3′-diaminobenzanilide, 3,4′-diaminobenzanilide, 4 , 4'-diaminobenzanilide, bis [4- (3-aminophenoxy) phenyl] methane, bis [4- (4-aminophenoxy) phenyl] methane, [4- (4-aminophenoxyphenyl)] [4- (3-aminophenoxyphenyl)] methane, 1,1-bis [4- (3-aminophenoxy) phenyl] ethane, 1,1-bis [4- (4-aminophenoxy) phenyl] ethane, 1,1- [4- (4-Aminophenoxyphenyl)] [4- (3-aminophenoxyphenyl)] ethane, 1,2-bis [4- (3-a Nophenoxy) phenyl] ethane, 1,2-bis [4- (4-aminophenoxy) phenyl] ethane, 1,2- [4- (4-aminophenoxyphenyl)] [4- (3-aminophenoxyphenyl) ] Ethane, 2,2-bis [4- (3-aminophenoxy) phenyl] propane, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 2,2- [4- (4-amino) Phenoxyphenyl)] [4- (3-aminophenoxyphenyl)] propane, 2,2-bis [3- (3-aminophenoxy) phenyl] -1,1,1,3,3,3-hexafluoropropane, 2,2-bis [4- (4-aminophenoxy) phenyl] -1,1,1,3,3,3-hexafluoropropane, 2,2- [4- (4-aminophenoxyphenyl)] [4 -(3-Ami Phenoxyphenyl)]-1,1,1,3,3,3-hexafluoropropane, 1,3-bis (3-aminophenoxy) benzene, 1,4-bis (3-aminophenoxy) benzene, 1,4 -Bis (4-aminophenoxy) benzene, 1,3-bis (4-aminophenoxy) benzene, 4,4'-bis (4-aminophenoxy) biphenyl, 4,4'-bis (3-aminophenoxy) biphenyl Bis [4- (3-aminophenoxy) phenyl] ketone, bis [4- (4-aminophenoxy) phenyl] ketone, bis [4- (3-aminophenoxy) phenyl] ether, bis [4- (4- Aminophenoxy) phenyl] ether, polytetramethylene oxide-di-P-aminobenzoate, poly (tetramethylene / 3-methyltetramethyl) Ether) glycol bis (4-aminobenzoate), trimethylene-bis (4-aminobenzoate), p-phenylene-bis (4-aminobenzoate), m-phenylene-bis (4-aminobenzoate), bisphenol A-bis ( 4-aminobenzoate), 2,4-diaminobenzoic acid, 2,5-diaminobenzoic acid, 3,5-diaminobenzoic acid, 3,3′-diamino-4,4′-dicarboxybiphenyl, 4,4 ′ -Diamino-3,3'-dicarboxybiphenyl, 4,4'-diamino-2,2'-dicarboxybiphenyl, [bis (4-amino-2-carboxy) phenyl] methane, [bis (4-amino- 3-carboxy) phenyl] methane, [bis (3-amino-4-carboxy) phenyl] methane, [bis (3-amino-5-carboxy) phenyl] methane, , 2-bis [3-amino-4-carboxyphenyl] propane, 2,2-bis [4-amino-3-carboxyphenyl] propane, 2,2-bis [3-amino-4-carboxyphenyl] hexafluoro Propane, 2,2-bis [4-amino-3-carboxyphenyl] hexafluoropropane, 3,3′-diamino-4,4′-dicarboxydiphenyl ether, 4,4′-diamino-3,3′-di Carboxydiphenyl ether, 4,4′-diamino-2,2′-dicarboxydiphenyl ether, 3,3′-diamino-4,4′-dicarboxydiphenyl sulfone, 4,4′-diamino-3,3′-dicarboxy Diphenylsulfone, 4,4′-diamino-2,2′-dicarboxydiphenylsulfone, 2,3-diaminophenol, 2, Diaminophenols such as 4-diaminophenol, 2,5-diaminophenol, 3,5-diaminophenol, 3,3′-diamino-4,4′-dihydroxybiphenyl, 4,4′-diamino-3,3 ′ Hydroxybiphenyl compounds such as -dihydroxybiphenyl, 4,4'-diamino-2,2'-dihydroxybiphenyl, 4,4'-diamino-2,2 ', 5,5'-tetrahydroxybiphenyl, 3,3' Dihydroxydiphenylmethanes such as -diamino-4,4'-dihydroxydiphenylmethane, 4,4'-diamino-3,3'-dihydroxydiphenylmethane, 4,4'-diamino-2,2'-dihydroxydiphenylmethane, 2,2- Bis [3-amino-4-hydroxyphenyl] propane, 2,2-bis [4-amino-3- Bis [hydroxyphenyl] propanes such as droxyphenyl] propane, 2,2-bis [3-amino-4-hydroxyphenyl] hexafluoropropane, 2,2-bis [3-amino-4-hydroxyphenyl] hexa Bis [hyhydroxyphenyl] hexafluoropropanes such as fluoropropane, 3,3′-diamino-4,4′-dihydroxydiphenyl ether, 4,4′-diamino-3,3′-dihydroxydiphenyl ether, 4,4′- Hydroxydiphenyl ethers such as diamino-2,2′-dihydroxydiphenyl ether, 3,3′-diamino-4,4′-dihydroxydiphenyl sulfone, 4,4′-diamino-3,3′-dihydroxydiphenyl sulfone, 4,4 '-Diamino-2,2'-dihydroxydiphenylsulfur Dihydroxydiphenyl sulphones such as 3,3′-diamino-4,4′-dihydroxydiphenyl sulfide, 4,4′-diamino-3,3′-dihydroxydiphenyl sulfide, 4,4′-diamino-2, Dihydroxydiphenyl sulfides such as 2′-dihydroxydiphenyl sulfide, 3,3′-diamino-4,4′-dihydroxydiphenyl sulfoxide, 4,4′-diamino-3,3′-dihydroxydiphenyl sulfoxide, 4,4′- Dihydroxydiphenyl sulfoxides such as diamino-2,2′-dihydroxydiphenyl sulfoxide, and bis [(hydroxyphenyl) phenyl] alkane compounds such as 2,2-bis [4- (4-amino-3-hydroxyphenoxy) phenyl] propane 4,4′-bis (4- Bis [(hydroxyphenoxy) biphenyl compounds such as mino-3-hydroxyphenoxy) biphenyl, bis [(hydroxyphenoxy) such as 2,2-bis [4- (4-amino-3-hydroxyphenoxy) phenyl] sulfone Phenyl] sulfone compound, 4,4′-diamino-3,3′-dihydroxydiphenylmethane, 4,4′-diamino-2,2′-dihydroxydiphenylmethane, 2,2-bis [3-amino-4-carboxy Bis (hydroxyphenoxy) biphenyl compounds such as phenyl] propane and 4,4′-bis (4-amino-3-hydroxyphenoxy) biphenyl. These can be used alone or in combination of two or more.

  More preferably, the diamino compound used in the synthesis of the polyimide precursor having a partially imidized urethane bond is m-phenylenediamine, bis (3-aminophenyl) sulfone, bis (4-aminophenyl) sulfone, 3, 3′-diaminodiphenylmethane, bis [4- (3-aminophenoxy) phenyl] sulfone, bis [4- (3-aminophenoxy) phenyl] methane, 2,2-bis [4- (4-aminophenoxy) phenyl] Propane, 1,3-bis (3-aminophenoxy) benzene, 1,4-bis (3-aminophenoxy) benzene, 1,4-bis (4-aminophenoxy) benzene, 1,3-bis (4-amino) Aromatic diamines such as phenoxy) benzene. Since the heat resistance of the cured film obtained by using said aromatic diamine improves, it is desirable.

<(B) Photosensitive resin>
The photosensitive resin (B) in the present invention is a resin in which a chemical bond is formed by a photopolymerization initiator. Among these, a resin having at least one unsaturated double bond in the molecule is preferable. Furthermore, the unsaturated double bond is an acryl group (CH ₂ ═CH— group), a methacryloyl group (CH═C (CH ₃ ) — group) or a vinyl group (—CH═CH— group). Is preferred.

  Examples of the photosensitive resin (B) include bisphenol F EO modified (n = 2 to 50) diacrylate, bisphenol A EO modified (n = 2 to 50) diacrylate, and bisphenol S EO modified (n = 2 to 50). Diacrylate, bisphenol F EO modified (n = 2-50) dimethacrylate, bisphenol A EO modified (n = 2-50) dimethacrylate, bisphenol S EO modified (n = 2-50) dimethacrylate, 1,6-hexane Diol diacrylate, neopentyl glycol diacrylate, ethylene glycol diacrylate, pentaerythritol diacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, dipentaerythritol hexaacrylate, tetramethyl Propane tetraacrylate, tetraethylene glycol diacrylate, 1,6-hexanediol dimethacrylate, neopentyl glycol dimethacrylate, ethylene glycol dimethacrylate, pentaerythritol dimethacrylate, trimethylolpropane trimethacrylate, pentaerythritol trimethacrylate, dipenta Erythritol hexamethacrylate, tetramethylolpropane tetramethacrylate, tetraethylene glycol dimethacrylate, methoxydiethylene glycol methacrylate, methoxypolyethylene glycol methacrylate, β-methacryloyloxyethyl hydrogen phthalate, β-methacryloyloxyethyl hydrogen succinate, 3-chloro-2- Hide Xylpropyl methacrylate, stearyl methacrylate, phenoxyethyl acrylate, phenoxydiethylene glycol acrylate, phenoxy polyethylene glycol acrylate, β-acryloyloxyethyl hydrogen succinate, lauryl acrylate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, polyethylene glycol Dimethacrylate, 1,3-butylene glycol dimethacrylate, 1,6-hexanediol dimethacrylate, neopentyl glycol dimethacrylate, polypropylene glycol dimethacrylate, 2-hydroxy-1,3-dimethacryloxypropane, 2,2-bis [4- (Methacryloxyethoxy ) Phenyl] propane, 2,2-bis [4- (methacryloxy diethoxy) phenyl] propane, 2,2-bis [4- (methacryloxy polyethoxy) phenyl] propane, polyethylene glycol diacrylate, tripropylene glycol diacrylate, Polypropylene glycol diacrylate, 2,2-bis [4- (acryloxydiethoxy) phenyl] propane, 2,2-bis [4- (acryloxypolyethoxy) phenyl] propane, 2-hydroxy-1-acryloxy-3-methacryl Roxypropane, trimethylolpropane trimethacrylate, tetramethylolmethane triacrylate, tetramethylolmethane tetraacrylate, methoxydipropylene glycol methacrylate, methoxytriethylene group Cole acrylate, nonylphenoxy polyethylene glycol acrylate, nonyl phenoxy polypropylene glycol acrylate, 1-acryloyloxypropyl-2-phthalate, isostearyl acrylate, polyoxyethylene alkyl ether acrylate, nonylphenoxyethylene glycol acrylate, polypropylene glycol dimethacrylate, 1,4 -Butanediol dimethacrylate, 3-methyl-1,5-pentanediol dimethacrylate, 1,6-mexanediol dimethacrylate, 1,9-nonanediol methacrylate, 2,4-diethyl-1,5-pentanediol di Methacrylate, 1,4-cyclohexanedimethanol dimethacrylate, dipropylene glycol diacrylate, Tricyclodecane dimethanol diacrylate, 2,2-hydrogenated bis [4- (acryloxy polyethoxy) phenyl] propane, 2,2-bis [4- (acryloxy polypropoxy) phenyl] propane, 2,4-diethyl -1,5-pentanediol diacrylate, ethoxylated tomethylolpropane triacrylate, propoxylated tomethylolpropane triacrylate, isocyanuric acid tri (ethane acrylate), pentathritol tetraacrylate, ethoxylated pentathritol tetraacrylate, propoxylation Pentathritol tetraacrylate, ditrimethylolpropane tetraacrylate, dipentaerythritol polyacrylate, triallyl isocyanurate, glycidyl methacrylate, glycidyl ali Ether, 1,3,5-triacryloylhexahydro-s-triazine, triallyl1,3,5-benzenecarboxylate, triallylamine, triallyl citrate, triallyl phosphate, arborbital, diallylamine, diallyldimethylsilane, diallyl Disulfide, diallyl ether, zalyl sialate, diallyl isophthalate, diallyl terephthalate, 1,3-dialyloxy-2-propanol, diallyl sulfide diallyl maleate, 4,4′-isopropylidene diphenol dimethacrylate, 4,4′-isopropyl Redene diphenol diacrylate and the like are preferable, but are not limited thereto. In particular, the repeating unit of EO (ethylene oxide) contained in one molecule of diacrylate or methacrylate is preferably in the range of 2-50, more preferably 2-40. By using an EO repeating unit in the range of 2 to 50, the solubility of the photosensitive resin composition in an aqueous developer typified by an alkaline aqueous solution is improved, and the development time is shortened. Furthermore, it is difficult for stress to remain in the cured film obtained by curing the photosensitive resin composition. For example, among the printed wiring boards, when laminated on a flexible printed wiring board based on a polyimide resin, curling of the printed wiring board is prevented. Features such as being able to be suppressed.

  In particular, it is particularly preferable to use the EO-modified diacrylate or dimethacrylate together with an acrylic resin having 3 or more acrylic groups or methacrylic groups in order to improve developability. For example, ethoxylated isocyanuric acid EO-modified triacrylate, Ethoxylated isocyanuric acid EO modified trimethacrylate, ethoxylated trimethylolpropane triacrylate, ethoxylated trimethylolpropane triacrylate, ethoxylated trimethylolpropane triacrylate, trimethylolpropane triacrylate, propoxylated trimethylolpropane triacrylate, pentaerythritol tri Acrylate, ethoxylated pentaerythritol tetraacrylate, ethoxylated pentaerythritol tetraacrylate, ditrimethyl Propanetetraacrylate, ditrimethylolpropane tetraacrylate, propoxylated pentaerythritol tetraacrylate, pentaerythritol tetraacrylate, dipentaerythritol hexaacrylate, 2,2,2-trisacryloyloxymethyl ethyl succinic acid, 2,2, 2-trisacryloyloxymethylethylphthalic acid, propoxylated ditrimethylolpropane tetraacrylate, propoxylated dipentaerythritol hexaacrylate, ethoxylated isocyanuric acid triacrylate, ε-caprolactone modified tris- (2-acryloxyethyl) isocyanurate, Caprolactone-modified ditrimethylolpropane tetraacrylate, the following general formula (9)

(Wherein a + b = 6 and n = 12.), A compound represented by the following general formula (10)

(Wherein a + b = 4 and n = 4), a compound represented by the following formula (11)

A compound represented by the following general formula (12)

(Where m = 1, a = 2, b = 4, or m = 1, a = 3, b = 3, or m = 1, a = 6, b = 0, or m = 2, a = 6 , B = 0.), A compound represented by the following general formula (13)

(Wherein a + b + c = 3.6), a compound represented by the following formula (14)

A compound represented by the following general formula (15)

An acrylic resin such as a compound represented by the formula (where m · a = 3, a + b = 3, where “m · a” is a product of m and a) is preferably used.

  In addition, hydroxyl groups in the molecular structure skeleton such as 2-hydroxy-3-phenoxypropyl acrylate, monohydroxyethyl acrylate phthalate, ω-carboxy-polycaprolactone monoacrylate, acrylic acid dimer, pentaerythritol tri and tetraacrylate, Those having a carbonyl group are also preferably used.

  In addition, any photosensitive resin such as an epoxy-modified acrylic (methacrylic) resin, a urethane-modified acrylic (methacrylic) resin, or a polyester-modified acrylic (methacrylic) resin may be used.

  In addition, although it is also possible to use 1 type as a photosensitive resin, using 2 or more types together is preferable when improving the heat resistance of the cured film after photocuring.

<(C) Photopolymerization initiator>
The (C) photopolymerization initiator in the present invention is a compound that is activated by energy such as UV and starts and accelerates the reaction of the photosensitive resin. Examples of the (C) photopolymerization initiator include Mihilaz ketone, 4,4′-bis (diethylamino) benzophenone, 4,4 ′, 4 ″ -tris (dimethylamino) triphenylmethane, and 2,2 ′. -Bis (2-chlorophenyl) -4,4 ', 5,5'-tetraphenyl-1,2'-diimidazole, acetophenone, benzoin, 2-methylbenzoin, benzoin methyl ether, benzoin ethyl ether, Benzoin isopropyl ether, benzoin isobutyl ether, 2-t-butylanthraquinone, 1,2-benzo-9,10-anthraquinone, methylanthraquinone, thioxanthone, 2,4-diethylthioxanthone, 2-isopropylthioxanthone, 1- Hydroxycyclohexyl phenyl ketone, diacetylbenzyl, benzyldimethyl Ketal, benzyldiethylketal, 2 (2′-furylethylidene) -4,6-bis (trichloromethyl) -S-triazine, 2 [2 ′ (5 ″ -methylfuryl) ethylidene] -4, 6-bis (trichloromethyl) -S-triazine, 2 (p-methoxyphenyl) -4,6-bis (trichloromethyl) -S-triazine, 2,6-di (p-azidobenzal) -4-methylcyclohexanone, 4,4′-diazidochalcone, di (tetraalkylammonium) -4,4′-diazidostilbene-2,2′-disulfonate, 2,2-dimethoxy-1,2-diphenylethane-1-one 1-hydroxy-cyclohexyl-phenyl-ketone, 2-hydroxy-2-methyl-1-phenyl-propan-1-one, 1- [4- (2-hydroxyethoxy)- Enyl] -2-hydroxy-2-methyl-1-propan-1-one, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropan-1-one, 2-benzyl-2- Dimethylamino-1- (4-morpholinophenyl) -butane-1, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, bis (2,6-dimethoxybenzoyl) -2,4,4- Trimethyl-pentylphosphine oxide, 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide, 2-hydroxy-2-methyl-1-phenyl-propane-1-ketone, bis (n5-2,4-cyclopentadiene -1-yl) -bis (2,6-difluoro-3- (1H-pyrrol-1-yl) -phenyl) titanium, 1,2- Kutanonedione, 1- [4- (phenylthio)-, 2- (O-benzoyloxime)], iododium, (4-methylphenyl) [4- (2-methylpropyl) phenyl] -hexafluorophosphate (1 -), Ethyl-4-dimethylaminobenzoate, 2-ethylhexyl-4-dimethylaminobenzoate, ethanone, 1- [9-ethyl-6- (2-methylbenzoyl) -9H-carbazol-3-yl]-, 1 -(O-acetyloxyome) etc. are mentioned. The photopolymerization initiator is desirably selected as appropriate, and it is desirable to use a mixture of one or more.

  In the photosensitive resin composition of the present invention, the component (A), the component (B) and the component (C) are 10 to 200 parts by weight of the component (B) with respect to 100 parts by weight of the solid content of the component (A). (C) It is preferable to mix | blend a component so that it may become 0.1-50 weight part.

  The blending ratio is preferable because various properties (such as electrical insulation reliability) of the cured product and insulating film finally obtained are improved.

  When the photosensitive resin of the component (B) is less than the above range, the heat resistance of the cured film after photocuring the photosensitive resin composition is lowered, and the contrast when exposed and developed is difficult to be applied. Therefore, it may not be preferable. If the amount is too large, the coating film obtained by applying the photosensitive resin composition onto the substrate and drying the solvent will become more sticky, resulting in decreased productivity and increased crosslink density. If it is too much, the cured film becomes brittle and easily cracked, which may not be preferable. For this reason, it is possible to set the resolution at the time of exposure / development to an optimal range by setting the value within the above range.

  (C) When there are few photoinitiators than the said range, the hardening reaction of the acrylic resin at the time of light irradiation hardly occurs, and hardening may become inadequate in many cases. Moreover, when there is too much, adjustment of light irradiation amount becomes difficult and may be in an overexposure state. Therefore, in order to advance the photocuring reaction efficiently, it is preferable to adjust within the above range.

<(D) Reactive flame retardant>
The (D) reactive flame retardant in the present invention has a reactive group capable of reacting with at least one other compound in the substance, and when added to a flammable substance such as plastic, wood, fiber, etc. A substance that can impart flame retardancy to a substance.

  In particular, when the reactive flame retardant is a phosphorus compound having a phosphorus atom in the molecule, it is preferable because no harmful gas is generated during combustion.

  Examples of the reactive group include a thermosetting group such as a hydroxyl group, an epoxy group, a carboxyl group, an amino group, and an isocyanate group, and a photosensitive group such as a vinyl group and a (meth) acryloyl group. When the reactive flame retardant has a photosensitive group as a reactive group, when the photosensitive resin composition is irradiated with energy such as UV and photocured, a part of the photosensitive group in the flame retardant is photosensitive. Since it reacts with the components in the resin composition to form a three-dimensional network structure, it is preferable because the resulting cured film has improved heat resistance, chemical resistance, and electrical insulation reliability.

  In particular, in the reactive group in the present invention, when the photosensitive group is a (meth) acryloyl group and is contained in the molecule, the reactivity of the reactive flame retardant is improved and the photosensitive resin composition is reduced. This is preferable because it can be cured by energy.

  Specific examples of the phosphorus compound having at least one (meth) acryloyl group in the molecule include, for example, tris (acryloyloxyethyl) phosphate, diphenyl-2-methacryloyloxyethyl phosphate, and the like. Is the following formula (16), (17) or (18)

And a compound having 1 to 4 (meth) acryloyl groups in the molecule, and / or a compound having 1 to 4 vinyl groups in the molecule, and / or (meth) acryloyl in the molecule. And compounds having a group and an epoxy group bonded directly or via another compound.

  When a phosphorus compound having at least one (meth) acryloyl group in the molecule is used, the hydrolysis resistance of the cured film obtained by curing the photosensitive resin composition under high temperature and high humidity is improved. Moreover, the bleed-out of the flame retardant component from the cured film can be suppressed.

  Moreover, the phosphorus compound which has at least 1 (meth) acryloyl group in the said molecule | numerator can be used individually or in combination of 2 or more types.

  The component (D) in the photosensitive resin composition of the present invention is preferably 1 to 100 parts by weight, more preferably 100 parts by weight with respect to 100 parts by weight of the components (A), (B), and (C). Is 5 to 50 parts by weight, particularly preferably 10 to 30 parts by weight.

  By adjusting the amount of the component (D) within the above range, sufficient flame retardancy is imparted to the photosensitive resin composition, and the cured film obtained by curing the photosensitive resin composition has heat resistance and resistance. It is preferable because chemical properties and electrical insulation reliability are improved.

  When the component (D) is less than the above range, the flame retardancy of the cured film obtained by curing the photosensitive resin composition may be inferior. Moreover, when there are more (D) components than the said range, the solubility with respect to the developing solution of the photosensitive resin composition falls, and fine processing may become difficult.

<(E) Thermosetting resin>
As the thermosetting resin used in the photosensitive resin composition of the present invention, epoxy resin, isocyanate resin, block isocyanate resin, bismaleimide resin, bisallyl nadiimide resin, acrylic resin, methacrylic resin, hydrosilyl cured resin, allyl cured Thermosetting resins such as resins and unsaturated polyester resins; side chain reactive group type thermosetting having reactive groups such as allyl group, vinyl group, alkoxysilyl group, hydrosilyl group at the side chain or terminal of the polymer chain Can be used. What is necessary is just to use the said thermosetting component, ie, (E) thermosetting resin, combining suitably 1 type (s) or 2 or more types.

  (E) As a thermosetting resin, it is more preferable to use an epoxy resin and a block isocyanate resin among these. By containing these components, heat resistance can be imparted to a cured film obtained by curing the photosensitive resin composition, and adhesion to a conductor such as a metal foil or a circuit board can be imparted.

  The epoxy resin contains at least two epoxy groups in the molecule, and is bisphenol A type epoxy resin, bisphenol AD type epoxy resin, bisphenol S type epoxy resin, bisphenol F type epoxy resin, bisphenol A novolac type epoxy resin. , Hydrogenated bisphenol A type epoxy resin, ethylene oxide adduct bisphenol A type epoxy resin, propylene oxide adduct bisphenol A type epoxy resin, novolac type epoxy resin, glycidyl ester type epoxy resin, biphenyl type epoxy resin, phenol novolac type epoxy resin, Alkylphenol novolac type epoxy resin, polyglycol type epoxy resin, cycloaliphatic epoxy resin, cyclopentadiene type epoxy resin, dicyclopentadi Emission type epoxy resin, cresol novolak type epoxy resins, glycidyl amine type epoxy resins, naphthalene type epoxy resins, urethane modified epoxy resins, rubber-modified epoxy resin, an epoxy resin such as epoxy-modified polysiloxane. These epoxy resins may be used alone or in combination of two or more at any ratio.

  Examples of the epoxy resin include, for example, the product name Epicron HP-4700 of a naphthalene type tetrafunctional epoxy resin manufactured by Dainippon Ink and Chemicals Co., Ltd. The name Epicron N-740, Epicron EXA-7240, which is a high heat resistance epoxy resin, Epicron N-660, N-665, N-670, N-680, N-655-, which is a cresol novolac type polyfunctional epoxy resin EXP, trade name of phenol novolac type epoxy resin Epicron N-740, trade name of tetraphenylethane type epoxy resin, Epicron ETePE, trade name of triphenylmethane type epoxy resin, Epicron ETrPM, trade name of Japan Epoxy Resin Co., Ltd. Bisphenol A type epoxy resin such as Tote Kasei Co., Ltd., bisphenol F type epoxy resin such as YDF-170 manufactured by Toto Kasei Co., Ltd. Phenol novolac type epoxy resin such as trade name EPPN-201 manufactured by Dow Chemical Co., Ltd., and trade name EOCN-125S, 103S, 104S manufactured by Nippon Kayaku Co., Ltd. Novolac type epoxy resin, trade name Epon 1031S manufactured by Japan Epoxy Resins Co., Ltd., trade name Araldite 0163 manufactured by Ciba Specialty Chemicals Co., Ltd., trade names Denacol EX-611, EX-614 manufactured by Nagase Chemical Co., Ltd. EX-614B, EX-622, EX-512, EX-521, EX 421, EX-411, EX-321 and other polyfunctional epoxy resins, Japan Epoxy Resin Co., Ltd. trade name Epicoat 604, Toto Kasei Co., Ltd. trade name YH434, Mitsubishi Gas Chemical Co., Ltd. trade name TETRAD-X, TERRAD-C, Nippon Kayaku Co., Ltd. trade name GAN, Sumitomo Chemical Co., Ltd. trade name ELM-120, etc. Amine type epoxy resin, Ciba Specialty Chemicals Co., Ltd. Heterocycle-containing epoxy resins such as the name Araldite PT810, and alicyclic epoxy resins such as ERL4234, 4299, 4221, and 4206 manufactured by UCC, and the like can be used alone or in combination of two or more.

  In addition to the epoxy resin, an epoxy compound having only one epoxy group in one molecule, for example, n-butyl glycidyl ether, phenyl glycidyl ether, dibromophenyl glycidyl ether, dibromocresyl glycidyl ether and the like may be used. In addition, alicyclic epoxy compounds such as 3,4-epoxycyclohexyl and methyl (3,4-epoxycyclohexane) carboxylate can be used in combination.

  Among these epoxy resins, an epoxy resin having two or more epoxy groups in one molecule is particularly preferable from the viewpoint of improving the heat resistance, solvent resistance, chemical resistance and moisture resistance of the photosensitive resin composition.

  The blocked isocyanate resin is a compound that is inactive at room temperature and is heated to dissociate blocking agents such as oximes, diketones, phenols, caprolactams, etc., and regenerate isocyanate groups. Product names Duranate 17B-60PX, Duranate TPA-B80E, Duranate MF-B60X, Duranate MF-K60X, Duranate E402-B80T, Asahi Kasei Chemicals Co., Ltd. Trade names Takenate B-830, Takenate B- 815N, Takenate B-846N, Takenate B-882N, trade names Coronate AP-M, Coronate 2503, Coronate 2507, Coronate 2513, Coronate 2515, Millionone manufactured by Nippon Polyurethane Industry Co., Ltd. Preparative MS-50 and the like. Particularly, the blocked isocyanate resin suitably used in the present invention is a block isocyanate compound such as hexamethylene diisocyanate type isocyanurate type, biuret type, adduct type, etc. whose dissociation temperature of the blocking agent is 160 ° C. or less, hydrogenated diphenylmethane diisocyanate type, This is an additive xylylene diisocyanate block isocyanate resin.

  It is preferable to use the above-mentioned blocked isocyanate resin because high adhesiveness with a base material can be imparted to the cured film obtained when the photosensitive resin composition is cured.

  These blocked isocyanate resins can be used alone or in combination of two or more.

  In the photosensitive resin composition of the present invention, examples of the thermosetting resin curing agent include phenol resins such as phenol novolac type phenol resins, cresol novolac type phenol resins, and naphthalene type phenol resins, amino resins, and urea resins. Melamine resins, dicyandiamide, dihydrazine compounds, imidazole compounds, Lewis acids, Bronsted acid salts, polymercaptan compounds and the like can be used in combination.

  The amount of the thermosetting resin used in the photosensitive resin composition of the present invention includes (A) a polyimide precursor having a partially imidized urethane bond, (B) a photosensitive resin, and (C) a photopolymerization initiator. It is preferable to blend so as to be 0.5 to 100 parts by weight with respect to 100 parts by weight of the total solid content. Particularly preferred is 1.0 to 50 parts by weight. It is preferable to add it in the above range since the heat resistance, chemical resistance and electrical insulation reliability of the cured film of the photosensitive resin composition can be improved.

  When the thermosetting resin of the component (E) is less than the above range, it is difficult to obtain the effect by adding, and when it is too much, the photosensitive resin composition is applied on the substrate. Further, since the stickiness of the coating film obtained by drying the solvent increases, the productivity decreases, and when the crosslinking density becomes too high, the cured film becomes brittle and easily cracked, which is not preferable.

  Moreover, in the photosensitive resin composition of this invention, you may use a hardening accelerator with a thermosetting resin. Such curing accelerators are not particularly limited, but include, for example, phosphine compounds such as triphenylphosphine; amine compounds such as tertiary amine, trimethanolamine, triethanolamine, and tetraethanolamine; 1,8-diaza -Borate compounds such as bicyclo [5,4,0] -7-undecenium tetraphenylborate, imidazole, 2-ethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-undecyl Imidazoles such as imidazole, 1-benzyl-2-methylimidazole, 2-heptadecylimidazole, 2-isopropylimidazole, 2,4-dimethylimidazole, 2-phenyl-4-methylimidazole; 2-methylimidazoline, 2-ethyl Imidazoline, 2 Imidazolines such as isopropylimidazoline, 2-phenylimidazoline, 2-undecylimidazoline, 2,4-dimethylimidazoline, 2-phenyl-4-methylimidazoline; 2,4-diamino-6- [2′-methylimidazolyl- ( 1 ′)]-ethyl-s-triazine, 2,4-diamino-6- [2′-undecylimidazolyl- (1 ′)]-ethyl-s-triazine, 2,4-diamino-6- [2 ′ And azine-based imidazoles such as -ethyl-4'-methylimidazolyl- (1 ')]-ethyl-s-triazine. Of these, 2-ethyl-4-methylimidazole, 2-phenyl-4-methylimidazole, 2,4-diamino-6- [2′-undecylimidazolyl- ( It is more preferable to use imidazoles such as 1 ′)]-ethyl-s-triazine.

<Other ingredients>
Various additives such as a filler, an adhesion assistant, an antifoaming agent, a leveling agent, a flame retardant, a colorant, and a polymerization inhibitor can be further added to the photosensitive resin composition of the present invention as necessary. As the filler, fine inorganic fillers such as silica, mica, talc, barium sulfate, wollastonite, and calcium carbonate, and fine organic polymer fillers may be contained. Moreover, as said antifoamer, a silicon type compound, an acryl-type compound, etc. can be contained, for example. Moreover, as said leveling agent, a silicon type compound, an acryl-type compound, etc. can be contained, for example. Moreover, as said flame retardant, a phosphate ester type compound, a halogen-containing compound, a metal hydroxide, an organic phosphorus compound etc. can be contained, for example. Moreover, as said coloring agent, a phthalocyanine type compound, an azo type compound, carbon black, a titanium oxide etc. can be contained, for example. Moreover, as said adhesion assistant (it is also called adhesiveness imparting agent), a silane coupling agent, a triazole type compound, a tetrazole type compound, a triazine type compound, etc. can be contained. Moreover, as said polymerization inhibitor, hydroquinone, hydroquinone monomethyl ether, etc. can be contained, for example. The above various additives can be used alone or in combination of two or more. Moreover, it is desirable to select each content suitably.

<Photosensitive resin composition solution>
The photosensitive resin composition of the present invention has high solubility in various organic solvents, for example, sulfoxide solvents such as dimethyl sulfoxide and diethyl sulfoxide, and formamide systems such as N, N-dimethylformamide and N, N-diethylformamide. Solvents, acetamide solvents such as N, N-dimethylacetamide, N, N-diethylacetamide, pyrrolidone solvents such as N-methyl-2-pyrrolidone and N-vinyl-2-pyrrolidone, phenol, o-, m- or Phenolic solvents such as p-cresol, xylenol, halogenated phenol, catechol, or hexamethylphosphoramide, γ-butyrolactone, methylmonoglyme (1,2-dimethoxyethane), methyldiglyme (bis (2-methoxyether) ) Ether), Methylto Glyme (1,2-bis (2-methoxyethoxy) ethane), methyltetraglyme (bis [2- (2-methoxyethoxyethyl)] ether), ethyl monoglyme (1,2-diethoxyethane), ethyl dig Symmetric glycol diethers such as lime (bis (2-ethoxyethyl) ether), butyldiglyme (bis (2-butoxyethyl) ether), γ-butyrolactone, N-methyl-2-pyrrolidone, methyl acetate, ethyl acetate , Isopropyl acetate, n-propyl acetate, butyl acetate, propylene glycol monomethyl ether acetate, ethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate (also known as carbitol acetate, 2- (2-butoxyethoxy) acetate )), Acetates such as diethylene glycol monobutyl ether acetate, 3-methoxybutyl acetate, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, dipropylene glycol methyl ether acetate, propylene glycol diacetate, 1,3-butylene glycol diacetate Dipropylene glycol methyl ether, tripropylene glycol methyl ether, propylene glycol n-propyl ether, dipropylene glycol n-propyl ether, propylene glycol n-butyl ether, dipropylene glycol n-butyl ether, tripylene glycol n-propyl ether , Propylene glycol phenyl ether, dipropylene glycol Lumpur dimethyl ether, 1,3-dioxolane, ethylene glycol monobutyl ether, diethylene glycol monoethyl ether, can be used diethylene glycol monobutyl ether, a solvent of ethers such as ethyl ether also ethylene glycol. In addition, as said solvent, low boiling point hexane, acetone, toluene, xylene etc. can be used together as needed.

  Among these, symmetric glycol diethers are particularly preferable because the photosensitive resin composition has high solubility.

  The photosensitive resin composition solution obtained by dissolving the photosensitive resin composition of the present invention in an organic solvent has a total solid content of 100 parts by weight of the components (A) to (D) or (A) to (E). On the other hand, the organic solvent is preferably blended in an amount of 10 to 100 parts by weight.

  By making the photosensitive resin composition solution within this range, the film reduction rate after drying becomes small, and the viscosity and viscosity of the photosensitive resin composition solution should be adjusted within the appropriate range for coating such as screen printing. This is desirable.

  When the organic solvent is less than the above range, the viscosity of the photosensitive resin composition solution becomes very high, coating becomes difficult, and foam entrainment during coating and leveling properties may be inferior. On the other hand, when the amount is larger than the above range, the viscosity of the photosensitive resin composition solution becomes very low, coating becomes difficult, and the circuit coverage may be inferior.

<Method for mixing photosensitive resin composition>
The photosensitive resin composition of the present invention is obtained by uniformly mixing the above components (A) to (D) or (A) to (E) and, if necessary, the above other components. A method for uniformly mixing the above components is not particularly limited, and may be mixed using a general kneading apparatus such as a three roll or bead mill apparatus. Moreover, when the viscosity of a solution is low, you may mix using a general stirring apparatus.

<Usage method of photosensitive resin composition>
A cured film or pattern can be formed as follows using the photosensitive resin composition of the present invention directly or after preparing the photosensitive resin composition solution. First, the photosensitive resin composition is applied to a substrate. Alternatively, the photosensitive resin composition solution is applied to a substrate and dried to remove the organic solvent. The substrate can be applied by screen printing, curtain roll, river roll, spray coating, spin coating using a spinner, or the like. Drying of the coating film (preferably thickness: 5 to 100 μm, particularly 10 to 100 μm) is performed at 120 ° C. or less, preferably 40 to 100 ° C.

  After the coating film is dried, a negative photomask is placed on the dried coating film and irradiated with actinic rays such as ultraviolet rays, visible rays, and electron beams. Next, the relief pattern can be obtained by washing out the unexposed portion with a developer using various methods such as shower, paddle, immersion, or ultrasonic wave. Since the time until the pattern is exposed varies depending on the spraying pressure and flow rate of the developing device and the temperature of the etching solution, it is desirable to find the optimum device conditions as appropriate.

  As the developer, an alkaline aqueous solution is preferably used. This developer may contain a water-soluble organic solvent such as methanol, ethanol, n-propanol, isopropanol, or N-methyl-2-pyrrolidone. Examples of the alkaline compound that gives the alkaline aqueous solution include hydroxides, carbonates, hydrogen carbonates, amine compounds, and the like of alkali metals, alkaline earth metals, or ammonium ions, specifically sodium hydroxide. , Potassium hydroxide, ammonium hydroxide, sodium carbonate, potassium carbonate, ammonium carbonate, sodium bicarbonate, potassium bicarbonate, ammonium bicarbonate, tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetraisopropylammonium Hydroxide, N-methyldiethanolamine, N-ethyldiethanolamine, N, N-dimethylethanolamine, triethanolamine, triisopropanolamine, trii Such as propylamine can be mentioned, the aqueous solution is a compound other than this as long as it exhibits basicity can also be naturally used. The concentration of the alkaline compound that can be suitably used in the development step of the photosensitive resin composition of the present invention is preferably 0.01 to 20% by weight, particularly preferably 0.02 to 10% by weight. Further, the temperature of the developer depends on the composition of the photosensitive resin composition and the composition of the alkali developer, and is generally 0 ° C. or higher and 80 ° C. or lower, more generally 10 ° C. or higher and 60 ° C. or lower. Is preferably used.

  The relief pattern formed by the development process is rinsed to remove unnecessary residues. Examples of the rinsing liquid include water and acidic aqueous solutions.

  Next, heat treatment is performed on the obtained relief pattern. By performing heat treatment to imidize a polyimide precursor having a partially imidized urethane bond, a cured film having high heat resistance can be obtained. The thickness of the cured film is determined in consideration of the wiring thickness and the like, but is preferably about 2 to 50 μm. It is desired that the final curing temperature at this time can be imidized by heating at a low temperature for the purpose of preventing oxidation of the wiring and the like and not reducing the adhesion between the wiring and the substrate.

  The imidization temperature at this time is preferably 100 ° C. or higher and 250 ° C. or lower, more preferably 120 ° C. or higher and 200 ° C. or lower, and particularly preferably 130 ° C. or higher and 180 ° C. or lower. If the final heating temperature is high, the wiring is oxidatively deteriorated, which is not desirable.

  The cured film formed from the photosensitive resin composition of the present invention has excellent heat resistance, electrical and mechanical properties, and particularly excellent flexibility.

  In addition, for example, the insulating film obtained from the photosensitive resin composition preferably has a thickness of about 2 to 50 μm and a resolution of at least 10 μm after photocuring, particularly a resolution of about 10 to 1000 μm. For this reason, the insulating film obtained from the photosensitive resin composition is particularly suitable as an insulating material for a high-density flexible substrate. Furthermore, it is used for various photo-curing wiring coating protective agents, photosensitive heat-resistant adhesives, electric wire / cable insulation coatings, and the like.

  In addition, this invention can provide the same insulating material, even if it uses the resin film obtained by apply | coating the said photosensitive resin composition solution to the base-material surface, and drying.

  EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited to these examples.

[Synthesis Example 1]
<Synthesis of polyimide precursor having partially imidized urethane bond>
In a separable flask pressurized with nitrogen, methyltriglyme (= 1,2-bis (2-methoxyethoxy) ethane) (95 g) was charged as a polymerization solvent, and 20.7 g (norbornene diisocyanate) was added thereto. 0.1004 mol) was added and heated to 80 ° C. to dissolve. To this solution, 50.0 g (0.025 mol) of polycarbonate diol (manufactured by Asahi Kasei Corporation: trade name PCDL T5652, polycarbonate diol represented by the following general formula (19), average molecular weight 2000), and dimethylolbutane A solution of 7.4 g (0.050 mol) of acid (2,2-bis (hydroxymethyl) butanoic acid) in methyltriglyme (50.0 g) was added over 1 hour.

(In the formula, q, r, and s are integers of 1 or more.)

  This solution was heated and stirred at 80 ° C. for 5 hours. After completion of the reaction, 3,22 '(4,0') benzophenone tetracarboxylic dianhydride (BTDA) 32.22 g (0.100 mol) and methyltriglyme (52.0 g) were added to the above reaction solution. did. After the addition, the mixture was heated to 200 ° C. and reacted for 3 hours. The terminal acid anhydride urethane imide oligomer solution was obtained by performing the said reaction. After completion of the reaction, the reaction solution was cooled to about 5 ° C. with ice.

  To this solution, 21.92 g (0.075 mol) of 1,3-bis (3-aminophenoxy) benzene was added and stirred at 5 ° C. for 4 hours to give the partially imidized urethane bond of the present invention. A polyimide precursor was obtained (weight average molecular weight 80,000, number average molecular weight 30,000).

  The solute concentration of this solution was 40%, and the viscosity of the solution was 750 poise at 23 ° C. This synthetic resin is abbreviated as resin A.

[Synthesis Example 2]
<Synthesis of polyimide precursor having partially imidized urethane bond>
In a separable flask pressurized with nitrogen, methyltriglyme (= 1,2-bis (2-methoxyethoxy) ethane) (66.5 g) was charged as a polymerization solvent, and norbornene diisocyanate was added to 10. 3 g (0.050 mol) was charged and dissolved by heating to 80 ° C. To this solution, 50.0 g (0.025 mol) of polycarbonate diol (manufactured by Asahi Kasei Co., Ltd .: trade name PCDL T5652, polycarbonate diol represented by the following general formula (19), average molecular weight 2000) was added to methyltriglyme ( A solution dissolved in 50.0 g) was added over 1 hour.

(In the formula, q, r, and s are integers of 1 or more.)

  This solution was heated and stirred at 80 ° C. for 5 hours. After completion of the reaction, 31.02 g (0.100 mol) of 3,3 ′, 4,4′-oxydiphthalic dianhydride (hereinafter referred to as ODPA) and methyltriglyme (52.0 g) were added to the above reaction solution. . After the addition, the mixture was heated to 200 ° C. and reacted for 3 hours. The terminal acid anhydride urethane imide oligomer solution was obtained by performing the said reaction. After completion of the reaction, the reaction solution was cooled to about 5 ° C. with ice.

  To this solution, 21.92 g (0.075 mol) of 1,3-bis (3-aminophenoxy) benzene was added and stirred at 5 ° C. for 4 hours to give the partially imidized urethane bond of the present invention. A polyimide precursor was obtained (weight average molecular weight 90,000, number average molecular weight 35,000).

  The solute concentration of this solution was 40%, and the viscosity of the solution was 800 poise at 23 ° C. This synthetic resin is abbreviated as resin B.

<Synthesis of reactive flame retardant>
[Synthesis Example 3]
An HCA-HQ represented by the following formula (17) (trade name: 9,10-dihydro-9-oxa-10- (2 manufactured by Sanko Co., Ltd.) was added to a 1 L reactor equipped with a stirrer, a reflux condenser, and a thermometer. , 5-dihydroxyphenyl) phosphaphenanthrene-10-oxide) 32.4 g (0.100 mol), glycidyl methacrylate 28.4 g (0.200 mol) and xylene 300 g were added, and the temperature was raised to 120 ° C., uniformly. After confirming that it was, TPP (triphenylphosphine) dissolved in xylene was added to 500 ppm with respect to the reaction mixture. Next, the reaction was carried out for 5 Hrs while maintaining the temperature at 120 ° C. After completion of the reaction, xylene was removed by evaporation under reduced pressure at 100 ° C. to obtain a pale yellow viscous liquid. The phosphorus content by elemental analysis of the product was 5.1% by mass. The obtained compound is abbreviated as reactive flame retardant A.

[Synthesis Example 4]
In a 1 L reactor equipped with a stirrer, a reflux condenser, and a thermometer, 31.0 g (0.100 mol) of diphenylphosphinylhydroquinone represented by the following formula (18), 28.4 g (0.200 mol) of glycidyl methacrylate After adding 300 g of xylene and raising the temperature to 120 ° C. and confirming that it was uniform, TPP (triphenylphosphine) dissolved in xylene was added to 500 ppm with respect to the reaction mixture. Next, the reaction was carried out for 5 Hrs while maintaining the temperature at 120 ° C. After completion of the reaction, xylene was removed by evaporation under reduced pressure at 100 ° C. to obtain a pale yellow viscous liquid. The phosphorus content by elemental analysis of the product was 4.9% by mass. The obtained compound is abbreviated as reactive flame retardant B.

[Synthesis Example 5]
An HCA represented by the following formula (16) (trade name: 9,10-dihydro-9-oxa-10-phosphaphenanthrene- manufactured by Sanko Co., Ltd.) was added to a 1 L reactor equipped with a stirrer, a reflux condenser, and a thermometer. 10-oxide) 21.5 g (0.100 mol), bisphenol A type epoxy acrylate (manufactured by Nippon Kayaku Kogyo Co., Ltd., trade name: Kayarad R-115) 51.4 g (0.100 mol) and xylene 300 g Then, after confirming that the temperature was raised to 120 ° C. and became uniform, the reaction was carried out for 5 hours while maintaining the temperature at 120 ° C. After completion of the reaction, xylene was removed by evaporation at 100 ° C. under reduced pressure to obtain a pale yellow viscous liquid. The phosphorus content by elemental analysis of the product was 4.2% by mass. The obtained compound is abbreviated as reactive flame retardant C.

(Examples 1-5)
<Preparation of photosensitive resin composition>
(A) The polyimide precursor having a partially imidized urethane bond obtained in Synthesis Examples 1-2, (B) a photosensitive resin, (C) a photopolymerization initiator, and obtained in Synthesis Examples 3-5 ( D) A reactive flame retardant, (E) a thermosetting resin, and other components were added to prepare a photosensitive resin composition. Table 1 shows the blending amount of each constituent raw material in the resin solid content and the kind of the raw material. In addition, 1,2-bis (2-methoxyethoxy) ethane which is a solvent in the table is the total amount of solvent including the solvent and the like contained in the above synthetic resin solution and the like. The following evaluation was carried out by completely defoaming the foam in the solution with a defoaming device.

<1> Product name NK Ester A-9300 (ethoxylated isocyanuric acid triacrylate) manufactured by Shin-Nakamura Chemical Co., Ltd.
<2> Product name NK ester BPE-1300 (bisphenol A EO-modified diacrylate) manufactured by Shin-Nakamura Chemical Co., Ltd.
<3> Product name of photopolymerization initiator manufactured by Ciba Japan Co., Ltd. <4> Product name of cresol novolac type polyfunctional epoxy resin manufactured by Dainippon Ink Chemical Co., Ltd. <5> Product name of silica particles manufactured by Nippon Aerosil Co., Ltd.

<Preparation of coating film on polyimide film>
The above photosensitive resin composition was cast and applied to an area of 100 mm × 100 mm on a 75 μm polyimide film (manufactured by Kaneka Corporation: trade name 75 NPI) using a Baker type applicator so that the final dry thickness was 25 μm. After drying at 80 ° C. for 20 minutes, a negative photomask with a line width / space width of 50 mm × 50 mm = 100 μm / 100 μm was placed and irradiated with ultraviolet rays with an integrated exposure amount of 300 mJ / cm ² to be exposed. Subsequently, spray development was performed for 60 seconds at a discharge pressure of 1.0 kgf / mm ² using a solution obtained by heating a 1.0 wt% sodium carbonate aqueous solution to 30 ° C. After development, the film was sufficiently washed with pure water, and then cured by heating in an oven at 160 ° C. for 90 minutes to prepare a cured film of the photosensitive resin composition.

<Evaluation of cured film>
The obtained cured film was evaluated for the following items. The evaluation results are shown in Table 2.

(I) Photosensitivity evaluation The photosensitivity evaluation of the photosensitive resin composition was determined by observing the surface of the cured film obtained in the above item <Preparation of coating film on polyimide film>.
◯: A clear photosensitive pattern with a line width / space width = 100/100 μm is drawn on the polyimide film surface, the line does not shake due to the peeling of the line portion, and there is no residual residue in the space portion. thing.
Δ: A clear line width / space width = 100/100 μm photosensitive pattern is drawn on the polyimide film surface, and the line portion is shaken due to peeling, but there is no undissolved residue in the space portion. thing.
×: A clear line width / space width = 100/100 μm photosensitive pattern was not drawn on the surface of the polyimide film, the line portion was peeled off, and a dissolution residue was generated in the space portion.

(Ii) Adhesiveness of cured film The adhesive strength of the cured film obtained in the above item <Preparation of coating film on polyimide film> was evaluated by a cross-cut tape method according to JIS K5400.
○: No peeling by cross-cut tape method Δ: 95% or more of the squares remain ×: The residual quantity of the squares is less than 80%

(Iii) Solvent resistance The solvent resistance of the cured film obtained in the above item <Preparation of coating film on polyimide film> was evaluated. In the evaluation method, the film was dipped in methyl ethyl ketone at 25 ° C. for 15 minutes and then air-dried, and the state of the film surface was observed.
○: There is no abnormality in the coating film.
X: Abnormality such as swelling or peeling occurs in the coating film.

(Iv) Flexibility A cured film laminated film of a photosensitive resin composition on the surface of a polyimide film having a thickness of 25 μm (Apical 25NPI manufactured by Kaneka Corporation) in the same manner as in the above item <Preparation of coating film on polyimide film>. Was made. The cured film laminated film was cut into a 30 mm × 10 mm strip, bent 10 times at 180 ° at 15 mm, and the coating film was visually confirmed to check for cracks.
○: The cured film has no cracks Δ: The cured film has some cracks ×: The cured film has cracks

(V) Insulation reliability Line width / space width = 100 μm on flexible copper-clad laminate (copper foil thickness 12 μm, polyimide film is Apical 25 NPI manufactured by Kaneka Co., Ltd., and copper foil is bonded with polyimide adhesive) A / 100 μm comb-shaped pattern was prepared, immersed in a 10% by volume sulfuric acid aqueous solution for 1 minute, washed with pure water, and subjected to a copper foil surface treatment. Then, the cured film of the photosensitive resin composition was produced on the comb pattern by the method similar to the above-mentioned <Preparation of the coating film on a polyimide film> method, and the test piece was adjusted. A 100 V direct current was applied to both terminals of the test piece in an environmental test machine at 85 ° C. and 85% RH, and changes in the insulation resistance value and occurrence of migration were observed.
○: A resistance value of 10 8 or more in 1000 hours after the start of the test and no occurrence of migration, dendrite, etc. ×: An occurrence of migration, dendrite, etc. in 1000 hours after the start of the test

(Vi) Wettability The wettability of the cured film obtained in the above item <Preparation of coating film on polyimide film> was evaluated according to JIS K6768.

(Vii) Solder heat resistance A cured film of a photosensitive resin composition is laminated on the surface of a 75 μm-thick polyimide film (Apical 75NPI manufactured by Kaneka Corporation) in the same manner as in the above item <Preparation of coating film on polyimide film>. A film was prepared.

The coated film was floated so that the surface coated with the cured film of the photosensitive resin composition was in contact with a solder bath completely dissolved at 260 ° C., and then pulled up 10 seconds later. The operation was performed three times, and the adhesive strength of the cured film was evaluated by a cross-cut tape method according to JIS K5400.
○: No peeling by cross-cut tape method Δ: 95% or more of the squares remain ×: The residual quantity of the squares is less than 80%

(Viii) Warpage A cured film laminated film of a photosensitive resin composition is applied to the surface of a 25 μm-thick polyimide film (Apical 25NPI manufactured by Kaneka Corporation) in the same manner as in the above item <Preparation of coating film on polyimide film>. Produced.

  The cured film was cut into a film having an area of 50 mm × 50 mm and placed on a smooth table so that the coating film was on the upper surface, and the warp height of the film edge was measured. A schematic diagram of the measurement site is shown in FIG. The smaller the amount of warpage on the polyimide film surface, the smaller the stress on the surface of the printed wiring board and the lower the amount of warping of the printed wiring board. The warp amount is preferably 5 mm or less.

(Ix) Flame retardancy In accordance with the flame retardancy test standard UL94 for plastic materials, a flame retardancy test was performed as follows. A cured film laminated film of a photosensitive resin composition was prepared on both sides of a polyimide film having a thickness of 25 μm (Apical 25NPI manufactured by Kaneka Corporation) in the same manner as in the above item <Preparation of coating film on polyimide film>. Cut out the sample prepared above into dimensions: 50 mm width x 200 mm length x 75 μm thickness (including the thickness of the polyimide film), put a marked line at 125 mm, round it into a cylinder with a diameter of about 13 mm, and above the marked line PI tape was affixed so that there was no gap in the overlapping part (75 mm location) and the upper part, and 20 flame retardant test tubes were prepared. Of these, 10 were treated at (1) 23 ° C./50% relative humidity / 48 hours, and the remaining 10 were treated at (2) 70 ° C. for 168 hours and then cooled in a desiccator containing anhydrous calcium chloride for 4 hours or more. The upper part of these samples is clamped and fixed vertically, and a burner flame is brought close to the lower part of the sample for 10 seconds to ignite. After 10 seconds, remove the burner flame and measure how many seconds after the flame or burning of the sample has disappeared.
○: For each condition ((1), (2)), the flame and combustion stopped within 5 seconds on average (average of 10) after the flame of the burner was moved away from the sample, and self-extinguishment within 10 seconds at maximum X: Some samples do not extinguish within 10 seconds, or flame rises to the top of the sample and burns

(X) Bleed-out The test piece after the above insulation reliability test was observed to observe a minute bulge on the surface of the test piece, a bulge on the copper wiring, a seepage of oily substances, and the like.
○: Swelled on the surface of the test piece and the copper wiring in 1000 hours after starting the test, and no abnormality such as oozing out was observed. ×: Swelled and oozed out on the surface of the test piece and the copper wiring in 1000 hours after starting the test. Any abnormalities such as

(Comparative Example 1)
Hexamethylenediamine (27.3 g, 0.235 mol) was dissolved in dimethylacetamide (240 g), and 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride (37.8 g, 0.118 mol) was added over 30 minutes. By gradually adding, an oligomer having a polyamide bond was obtained. After stirring uniformly for 1 hour, 30.2 g (0.094 mol) of 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride was added and stirring was continued for 1 hour to obtain a viscous solution. (Solute concentration 14% by weight). 50.0 g of the obtained polyimide precursor varnish (polyimide precursor: 14.5% by weight), 10.0 g of the phosphazene compound obtained in Synthesis Example 5 above, 1.0 g of 2,2-dimethoxy-2-phenylacetophenone, 10.0 g of methyl ethyl ketone was mixed and stirred at room temperature for 1 hour to obtain a photosensitive resin composition.

  An attempt was made to prepare a test piece of this composition in the same manner as in Example 1, but it did not exhibit solubility in a 1.0 wt% sodium carbonate aqueous solution as a developer, and pattern formation by exposure and development was impossible. there were. Although the physical property value of the test piece obtained by heating at 160 ° C. for 90 minutes was evaluated in the same manner as in Example 1, the imidation reaction of the polyimide precursor did not proceed by heating at 160 ° C. for 90 minutes. Therefore, good results were not obtained for all characteristics.

(Comparative Example 2)
A glass flask having a capacity of 2000 ml was charged with 176.09 g (598.5 mmol) of 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride and 254.26 g of methyltriglyme under a nitrogen atmosphere at 180 ° C. And stirred with heating. α, ω-bis (3-aminopropyl) polydimethylsiloxane (manufactured by Shin-Etsu Chemical Co., Ltd., KF8010, average molecular weight 830) 250.25 g (301.5 mmol) and 100 g of methyltriglyme were added and stirred uniformly at 180 ° C. for 60 minutes. Went. Further, 42.51 g (148.5 mmol) of bis (3-carboxy, 4-aminophenyl) methane and 100 g of methyltriglyme were added to this reaction solution, and the mixture was heated and stirred at 180 ° C. for 6 hours. This solution is a half-esterified solution.

  Separately from the above reaction apparatus, in a glass container with a capacity of 500 ml blocked from light, isocyanuric acid tris (2-acryloyloxyethyl) [manufactured by Toagosei Co., Ltd., M-315] 126.9 g (300 mmol) and methyl jig 120 g of lime was charged and stirred and dissolved at room temperature in a nitrogen atmosphere. Next, 83.0 g (100 mmol) of α, ω-bis (3-aminopropyl) polydimethylsiloxane (manufactured by Shin-Etsu Chemical Co., Ltd., KF8010, average molecular weight 830) and 52.9 g of diglyme were added, and the mixture was further stirred for 2 hours. A reaction solution of a photosensitive monomer in which one tris (2-acryloyloxyethyl) isocyanurate was added to both ends of diaminopolysiloxane was obtained. This solution is used as a photosensitive monomer solution.

  Next, 1.25 g of 2-hydroxyethyl methacrylate and 15.39 g of a photosensitive monomer solution are added to 50 g of the half esterified solution, and 2.57 g of Irgacure 907 (manufactured by Ciba Specialty Chemicals Co., Ltd.) is used as a photopolymerization initiator. 2,4-diethylthioxanthone (Nippon Kayaku Co., Ltd., DETX) 0.51 g, p-dimethylaminobenzoic acid ethyl ester (Nippon Kayaku Co., Ltd., EDMAB) 1.02 g, silicon-based antifoaming agent (Dow Corning) , DB-100) 0.13 g, Aerosil (average particle size: 0.01 μm) 2.56 g, talc (average particle size: 1.8 μm) 5.19 g, and stirred at room temperature (25 ° C.) for 2 hours. The mixture was allowed to stand for 1 hour, and then uniformly mixed by a three roll mill to obtain a photosensitive imidosiloxane oligomer composition.

  50 g of this photosensitive imidosiloxane oligomer composition, 3.2 g of an epoxy resin (Japan Epoxy Resin Co., Ltd., Epicoat 152) and 0.032 g of 2-ethyl-4-methylimidazole were added and stirred for 1 hour at room temperature. A functional resin composition was obtained.

  The physical properties of this composition were evaluated in the same manner as in Example 1. The results are listed in Table 3.

(Comparative Example 3)
After introducing air into a reaction vessel equipped with a stirrer, thermometer, cooling tube and air introduction tube, 196.8 g of polycarbonate diol (manufactured by Daicel Chemical Industries, Plaxel CD205PL, average molecular weight 500), dimethylolbutanoic acid (Mitsubishi) Chemical Co., Ltd.) 58.3 g, Diethylene glycol (Nisso Maruzen Chemical Co., Ltd.) 37.6 g, 1,4-cyclohexanedimethanol monoacrylate (Mitsubishi Chemical Corporation) 148.1 g, p-methoxyphenol (Wako Pure Chemical Industries, Ltd.) 0.55 g, dibutyltin laurate (Tokyo Fine Chemicals Co., Ltd., L101) 0.55 g and methyl ethyl ketone (Tonen Kagaku Co., Ltd.) 110.2 g were charged under an air stream. The temperature was raised to 65 ° C. with stirring. 305.9 g of trimethylhexamethylene diisocyanate (manufactured by Huls Japan Co., Ltd., VESTANAT TMDI) was charged into the dropping vessel and uniformly dropped into the reaction vessel over 3 hours while maintaining the temperature at 65 ± 3 ° C. After completion of the dropping, the dropping container was washed with 76.5 parts of methyl ethyl ketone, and the washing solution was directly put into the reaction container. The mixture was further kept warm for 2 hours with stirring, and then heated to 75 ° C. Thereafter, stirring and heating were continued at 75 ± 3 ° C. until the isocyanate peak in the infrared absorption spectrum disappeared. The isocyanate peak disappeared in about 6 to 8 hours. After confirming the disappearance of this peak, the temperature was lowered to 60 ° C., 9.3 g of methanol (manufactured by Wako Pure Chemical Industries, Ltd.) was added, and the mixture was kept at 60 ± 3 ° C. for 30 minutes. Thereafter, 56.4 g of methyl ethyl ketone was added to obtain a transparent resin solution. This resin had a solid content of 75.6%, an acid value of 22.2 mg KOH / g, and a viscosity of 1,810 cP. 62.5 g of the obtained resin solution (solid content 50 g), 2,2′-bis (4-methacryloxypentaethoxyphenyl) propane 30 g, (methacrylic acid, methyl methacrylate and butyl acrylate in a weight ratio of 22:71 : A copolymer having a weight average molecular weight of 80,000 and an acid value of 143 mgKOH / g copolymerized at a ratio of 7 was dissolved in methyl cellosolve / toluene (6/4, weight ratio) to a solid content of 40% by weight. 162.5 g (solid content 65 g), benzophenone 3.5 g, N, N′-tetraethyl-4,4′-diaminobenzophenone 0.1 g, hexamethylene-based isocyanurate type isocyanate compound and methyl ethyl ketone oxime are reacted. 20 g of a 75 wt% methyl ethyl ketone solution of the blocked isocyanate compound obtained 15g), CR747 (condensed phosphoric acid ester-based additive-type flame retardant) 40 g, and stirred for 1 hour at room temperature in acetone 85 g, to obtain a photosensitive resin composition.

  The physical properties of this composition were evaluated in the same manner as in Example 1. The results are listed in Table 3.

(Comparative Example 4)
To a flask equipped with a stirrer, reflux condenser, dropping funnel, thermometer and nitrogen gas introduction tube, a mixed solution of propylene glycol monomethyl ether 60.0 g and toluene 40.0 g (hereinafter referred to as “solution s”) was added, and nitrogen was added. It stirred in the state heated at 80 degreeC, blowing in gas. On the other hand, as the polymerizable monomer, 20.0 g of methacrylic acid, 20.0 g of methyl methacrylate, and diphenyl- (2-methacryloyloxyethyl) phosphate (trade name “MR-260”, manufactured by Daihachi Chemical Industry Co., Ltd.) A solution in which 60.0 g of phosphorus (8.3 mass%) and 1.0 g of azobisisobutyronitrile are mixed (hereinafter referred to as “solution a”) and heated to 80 ° C. Solution a was added dropwise to the mixture over 3 hours, and the mixture was further stirred at 80 ° C. for 9 hours. Then, the phosphorus containing alkali-soluble resin solution (solid content: 41.0 mass%) was obtained by diluting with 45.0 g of propylene glycol monomethyl ether. The obtained phosphorus-containing alkali-soluble resin had a weight average molecular weight of 100,000, an acid value of 131 mgKOH / g, and a phosphorus content in the resin of 5.0% by mass. 156 g of the obtained phosphorus-containing alkali-soluble resin solution (solid content: 70 g), 35 g of the reactive flame retardant C obtained in Synthesis Example 5 above, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone -1 (manufactured by Ciba Specialty Chemicals, trade name “Irgacure 369”), 75 mass% methyl ethyl ketone solution of isocyanurate methyl ethyl ketone oxime block based on hexamethylene diisocyanate base isocyanate (manufactured by Sumika Bayer Urethane Co., Ltd., (Product name “BL3175”) 20 g (solid content 15 g) and methyl ethyl ketone 20 g were added and stirred at room temperature for 1 hour to obtain a photosensitive resin composition.

  The physical properties of this composition were evaluated in the same manner as in Example 1. The results are listed in Table 3.

DESCRIPTION OF SYMBOLS 1 Polyimide film which laminated the photosensitive resin composition 2 Warpage amount 3 Smooth stand

Claims (15)

  A photosensitive resin comprising at least (A) a polyimide precursor having a partially imidized urethane bond, (B) a photosensitive resin, (C) a photopolymerization initiator, and (D) a reactive flame retardant. Composition.   The photosensitive resin composition according to claim 1, wherein the polyimide precursor (A) further contains a polycarbonate skeleton. The above (A) polyimide precursor synthesizes a terminal isocyanate compound by reacting at least (a) a diol compound represented by the following general formula (1) and (b) a diisocyanate compound represented by the following general formula (2). Then, (c) a tetracarboxylic dianhydride represented by the following general formula (3) is reacted to synthesize a terminal acid anhydride urethane imide oligomer, and (d) a diamine represented by the following general formula (4) The photosensitive resin composition according to claim 1, which is obtained by addition reaction.

(In the formula, R represents a divalent organic group.)

(In the formula, X represents a divalent organic group.)

(In the formula, Y represents a tetravalent organic group.)

(In the formula, Z represents a divalent organic group.) The photosensitive resin composition according to claim 3, wherein the (a) diol compound contains at least a polycarbonate diol represented by the following general formula (5).

(In the formula, plural R _{1 s} each independently represent a divalent organic group, and m is an integer of 1 to 20.)   The photosensitive resin composition according to claim 1, wherein the polyimide precursor (A) further contains a carboxyl group in a side chain.   In the photosensitive resin composition, (A) a polyimide precursor having a partially imidized urethane bond, (B) a photosensitive resin, and (C) a photopolymerization initiator, (A) a partially imidized urethane bond. (B) 10 to 200 parts by weight of the photosensitive resin, and (C) the photopolymerization initiator is 0.1 to 50 parts by weight based on 100 parts by weight of the solid content of the polyimide precursor. The photosensitive resin composition of any one of Claims 1-5 characterized by the above-mentioned.   The photosensitive resin composition according to claim 1, wherein the (D) reactive flame retardant is a phosphorus compound having at least one photosensitive group in the molecule.   The photosensitive resin composition according to claim 7, wherein the photosensitive group according to claim 7 is a (meth) acryloyl group.   The blending ratio of the (D) reactive flame retardant is (A) a polyimide component having a partially imidized urethane bond, (B) a photosensitive resin, and (C) a total solid content of 100% by weight of a photopolymerization initiator. It mix | blends so that it may become 1-100 weight part with respect to a part, The photosensitive resin composition of any one of Claims 1-8 characterized by the above-mentioned.   Furthermore, (E) thermosetting resin is contained, The photosensitive resin composition of any one of Claims 1-9 characterized by the above-mentioned.   The blending ratio of the (E) thermosetting resin is (A) a polyimide content having a partially imidized urethane bond, (B) a photosensitive resin, and (C) a total solid content of 100 weight by photopolymerization initiator. It mix | blends so that it may become 0.5-100 weight part with respect to a part, The photosensitive resin composition of any one of Claims 1-10 characterized by the above-mentioned.   The photosensitive resin composition solution obtained by melt | dissolving the photosensitive resin composition of any one of Claims 1-11 in an organic solvent at least.   The resin film obtained by apply | coating the photosensitive resin composition solution of Claim 12 to the base-material surface, and drying.   An insulating film obtained by curing the resin film according to claim 13.   The printed wiring board with an insulating film which coat | covered the insulating film of Claim 14 on the printed wiring board.

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