JPS61174221A - Photocurable composition - Google Patents

Abstract

PURPOSE:To obtain a photocurable composition which can give a cured product excellent in electrical properties, free from contamination of a plating solution and suitable as a liquid crystal, by mixing an epoxy resin with a photosensitive aromatic onium salt and a sensitizer having a polymerizable substituent. CONSTITUTION:A photocurable composition comprising 100pts.wt. epoxy resin (A), 0.1-5pts.wt. photosensitive aromatic onium salt (B) and 0.001-0.5pt.wt. photosensitizer having a photopolymerizable substituent. Examples of especially useful epoxy resins (A) include alicyclic epoxy resin, bisphenol A epoxy resin and bisphenol F epoxy resin. Examples of the photosensitive aromatic onium salts (B) include triphenylphenacylphosphonium tetrafluoroborate, etc. The photosensitizers (C) are derivatives of the formula: X-Y (wherein X is a polymerizable substituent and Y is a polynuclear aromatic or heterocyclic compound).

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a novel photocurable composition. In more detail, we will develop electrical properties, adhesive properties, and liquid crystal suitability suitable for use as insulating materials and resist materials for electrical equipment, and especially as sealing and sealing materials in the manufacture of flat display cables such as liquid crystal cells. The present invention relates to a photocurable composition that provides a hard 1L product having the following characteristics.

[Conventional technology]

In recent years, the process of curing resin by light irradiation has attracted attention from the viewpoint of energy saving and workability. Among these, cationic photopolymerization of epoxy resins has a wide selection range of epoxy resins and shrinkage during curing is less than that of photoradical polymerization of acrylics, resulting in high Tg and high adhesive strength due to structural regularity. is expected.

Such prior art documents include: Japanese Patent Publication No. 52-1427;
No. 7, Special Publication No. 52-14278, Special Publication No. 52-142
No. 79, etc., but the above-mentioned simple combination of epoxy resin and photosensitive onium salt has a slow curing speed and lacks internal curing properties when curing thick walls, making it difficult to use it in the manufacturing process as an adhesive. It had drawbacks that made it unusable for image forming processes.

In addition, when a large amount of onium salt, which is a photoinitiator, is used to accelerate the curing speed, many decomposition products of the aromatic onium salt are generated, which deteriorates the electrical properties in insulation applications.
Metsukiresist material and L-'i (represent plating solution contamination,
Furthermore, as a liquid crystal sealing material, it greatly deteriorates suitability for liquid crystals.

On the other hand, the use of sensitizers has been studied in an attempt to effectively utilize photosensitive onium salts and improve the curing speed.

As such prior art document, JP-A-59-147001
Publication and S. P. Pappas et al;
“Photographic 5science and
Engineering"μs2('3), 140
(1979) is exemplified. In this sensitized system, it was possible to improve the curing speed and reduce the amount of onium salt decomposition products by optimizing the amount of onium salt used.
On the other hand, the cured product contains a low-molecular sensitizer, and the elution of these low-molecular compounds still poses a problem in terms of electrical properties, plating solution contamination, and suitability for liquid crystals.

[Problem that the invention seeks to solve]

In view of the fact that the above-mentioned problems of the prior art are caused by the inclusion of a large amount of elutable low molecules in the cured product after photocuring, the present invention aims to reduce the amount of elutable low molecules that remain in the cured product. electrical properties by finding compositions that reduce the amount of
An object of the present invention is to provide a photocurable composition that provides a cured product with excellent plating solution stain resistance and liquid crystal suitability.

[Failure to solve the problem]

As a result of intensive studies in view of the above-mentioned points, the present inventors have discovered that by adding a sensitizer having a polymerizable substituent to a photocationic polymerization system using an aromatic onium salt of an epoxy resin, the conventional niboxy - A composition with a faster curing speed and good internal curability compared to the case of using only an onium salt was obtained. Furthermore, it has been found that in this system, the amount of onium salt added to provide the optimum cured product is lower than when no sensitizer is added. In addition, elution of the sensitizer from the cured product obtained by irradiating a composition using a sensitizer with a polymerizable substituent is different from that when a sensitizer without a polymerizable substituent is used. The inventors have found that the cured product has extremely good electrical characteristics, plating solution contamination resistance, liquid crystal suitability, etc., and has completed the present invention.

That is, in the present invention, component (3) of the epoxy resin 100
Parts by weight, 0.1 to 5 parts by weight of component (B) of a photosensitive onium salt, and sensitizer (C) components 0001 to 05 having a polymerizable substituent as essential components. It is a curable composition, and is a photocurable composition that is rapidly cured by irradiation with active energy rays.

The present invention will be explained in detail below.

The epoxy resin that is the causative component used in the present invention is a compound having two or more oxirane rings either inside the resin, at the end, or in the cyclic structure. (1976), Chapters 2 to 5 can be used.

Particularly useful epoxy resins include l) alicyclic epoxy resins, such as Union Carbide (U, C, C0) trade name ERL;
-4221, 4289, 42o6, 4234, 4205, 4299, UVR-6100i Ciba Geigy product names CY-179, CY-178, CY-
180, CY-175; Chisso ■ brand names CX-221, CX-289, C
X-206, CX-301, CX-313i Daicel product name Celoxide-202111) Bisphenol A type epoxy resin, e.g. oily shell niboxy ■
Product names: Epicote 827, Epicote 828, Epicote 834, Epicote 8
36, 1001, 1004, 1007; Ciba Geigy product name Araldite CY252, Ciba Geigy C
Y250. Same CY260. Same CY280. Same 6o7
1, 6084, 6097 i Dow Chemical Company's trade name DER330, 331, 337, 661, 664; Dainippon Ink & Chemicals ■ trade name Epicron SOO.

Same 1010. Same 1000. 3010; Tobu Kasei's product master d)-to YD-128, YD-134,
YD-8125 111) Bisphenol F type resin, for example, oil-based shell epoxy ■ trade name Epicote 807 Tobu Kasei ■ trade name Ko &) - F-170i Dainippon Ink Chemical ■ trade name Evicron 830, same 1 Novolak Yani 4! 'Xylic resins, such as oily shell niboxy, trade names Epicote 152 and Epicote 154; Dow Chemical Company's trade names DEN-431 and Epicote 438;
439; Ciba Geigy product name EPN-1138, ECN-1
235: Dainippon Ink Chemical ■ trade name Ebicuron N-740,
Hydrogenated bisphenol A diglycidyl ether resins such as N-680, N-695, N-565, and N-57, for example, Adekal Resin EP-4080vl manufactured by Mudenka Kogyo ■.
) Epoxidized polybutadiene a) Epoxidized polybutadiene obtained by treating a butadiene homopolymer or butadiene copolymer (hereinafter abbreviated as butadiene-based polymer) with an organic peroxide to epoxidize the double bonds in the constituent units, e.g. Epoxidized butadiene BF-1000, BF- obtained by treating 1,2-polybutadiene with peracetic acid
2000 (trade name of Adeka Argus) etc. b) Terminal epoxidized butadiene-based polymers with epoxy groups introduced at the molecular ends by telomerization during polymerization, such as butadiene alone or copolymerizable with butadiene, hexadiene, A reaction intermediate (living polymer) obtained by performing living anionic polymerization of a mixture of other monomers such as isoprene at low temperatures in the presence of an alkali metal catalyst such as sodium or lithium.
Examples include terminal epoxidized butadiene-based polymers obtained by treating the polymer with a halogenated alkylene oxide represented by the general formula, such as epichlorohydrin, to introduce an epoxy group at the end of the polymer chain. Furthermore, resins obtained by chain-extending the above-mentioned engineered poxy resin with polyhydric alcohols, polyhydric amines, polyhydric carboxylic acids, etc. can be used. These various epoxy resins as component (3) may be used alone or in a mixture of two or more.

As the photosensitive aromatic onium salt of component (B) used in the present invention, aromatic onium salts of Group IV a group disclosed in Japanese Patent Publication No. 52-14277, Japanese Patent Publication No. 52-14
Aromatic onium salts of Ma group elements shown in Publication No. 278 and Va shown in Japanese Patent Publication No. 52-14279
Aromatic onium salts of group elements can be used.

More specifically, for example, triphenylphenacylphosphonium tetrafluoroborate, triphenyl hexafluoroantimonate, diphenyliodonium tetrafluoroborate, and the like can be used.

These onium salts release Lewis acids upon irradiation with active energy rays such as ultraviolet and violet rays, which initiate cationic polymerization of epoxy. The amount of the photosensitive aromatic onium salt (B) component used is 0.1 to 5 parts by weight, preferably 0.5 to 5 parts by weight, per 100 parts by weight of component (3).
4 parts by weight. If the amount of onium salt added is less than 0.1 part by weight, curing by active energy rays will be insufficient, and the cured product will have a low Tg and insufficient barrier properties. On the other hand, if the amount added is more than the upper limit of 5 parts by weight, the decomposition product of the aromatic onium salt will remain in the resin after photocuring, and this will elute and deteriorate the electrical properties, plating solution contamination, and liquid crystal suitability. .

If the aromatic onium salt is insufficiently compatible with the epoxy resin as the carrier component, the onium salt may be dissolved in a suitable solvent such as acetonitrile, propylene carbonate, or cellosolve solvent.

The sensitizer having a polymerizable substituent as component (C) used in the present invention is 320 to 500 expressed by the following formula.
They are derivatives of polynuclear aromatic compounds and derivatives of polynuclear heterocyclic compounds that have absorption in the ultraviolet and visible nm regions and have polymerizable substituents in the molecule.

Examples of the polymerizable substituent X include vinyl, vinyl ether, isopropenyl, acryloyl, methacryloyl, allyl, eixyglycidyl groups, or substituents containing bicycloorthoesters, spiroorthoesters, and spiroorthocarbonates. is exemplified.

Examples of the polynuclear aromatic compound or polynuclear heterocyclic compound Y include naphthalene, anthracene, phenanthrene, pyrene,
Naphthacene, R-rylene, pentacene, etc. Polynuclear heterocyclic compounds such as quinoline, phthalazine, quinoxaline, acridine, phenazine, phenanthroline, phenothiazine, eosin, methyleosine, etc.; As derivatives, the above compounds include hydroxy, methoxy, amine, carboxyl, nitro, Examples include compounds into which one or more substituents such as chloro and bromo, or two or more substituents are introduced.

The amount of the sensitizer (C) component used is 0.001 to 0.5 parts by weight per 100 parts by weight of the prisoner component. If the sensitizer exceeds the above-mentioned maximum limit of 0.5 parts by weight, even though it has a polymerizable substituent, components eluted from the cured product will deteriorate, resulting in a decrease in the properties of the sensitizer. Furthermore, upon curing, the curing properties tend to be poor. On the other hand, if the amount is less than the above-mentioned minimum limit of 0.001 parts by weight, the effect of adding the sensitizer, that is, the effect of improving curability and improving the properties of the cured product will not be significant.

In addition to the above-mentioned components (8) to (C), the resin composition according to the present invention may optionally contain photocationic polymerization, photoradical Acrylic ester or methacrylic ester monomers can be used within a range that does not impair the effects of the present invention in order to effect curing by a polymerization system. The amount of the acrylic ester or methacrylic ester monomer used is within 40 parts by weight per 100 parts by weight of component (A).

In addition, a solvent can be used in the resin composition according to the present invention for the purpose of improving its workability depending on the application, but this solvent may be a ketone type, ester type, ether type, aliphatic type or Various solvents belonging to aromatic hydrocarbons are used.

The amount of the solvent used is preferably within 20% by weight in the composition. The resin composition according to the present invention may contain a reactive diluent having one or more epoxy groups in the molecule in order to reduce the viscosity of the composition or adjust the reactivity. Examples of the reactive diluent mentioned here include t-butyl glycidyl ether, allyl glycidyl-13 ether, 2-ethylhexyl glycidyl ether,
Phenyl glycidyl ether, P-7'' tylphenyl glycidyl ether, glycerin glycidyl ether, neopentyl glycol diglycidyl ether, etc. can be used.

The amount of the reactive diluent to be used is within a range that does not impair the good properties and adhesive properties of the cured product, which are the objectives of the present invention, and is preferably within 20 parts by weight per 100 parts by weight of the active ingredient.

Furthermore, various modifying additives can be added to the resin composition according to the present invention as required for modifying physical properties or for purposes of use.

For example, granular or acicular spacers to maintain appropriate spacing between liquid crystal cells during the manufacture of liquid crystal cells; fillers such as silica and glass beads; silicone-based or titanate-based and other coupling agents; thixotropic agents such as Aerosil and bentone for imparting screen printability; leveling agents such as Florade; extender pigments such as aluminum hydroxide and barium hydroxide; petroleum resins, Improved polymeric materials such as rosin, nylon, and acrylic resins can also be included.

In order to cure the resin composition according to the present invention, a wavelength of 320
Ultraviolet and visible light of ~500 nm is effective. Examples of this radiation source include a low-pressure mercury lamp, a red-pressure mercury lamp, an ultra-pressure mercury lamp, a metal lydranzo, and an argon gas laser.

Other active energy rays that can be used for curing include X-rays and electron beams. Furthermore, although the present composition is sufficiently cured by irradiation with active energy rays and exhibits properties that meet the intended purpose, even better properties can be obtained by leaving it in a heating chamber after irradiation.

An example of this temperature range is 50 to 80°C for 2 to 20 hours.

The photocurable composition of the present invention can be used as a protective and insulating coating, inkuri ink, sealant, photoresist, solder resist, holating, laminating adhesive, and various other adhesives. be done. The initiation mechanism of the aromatic onium salt, which is a photocationic initiator, is particularly useful as an adhesive for forming glass cells of flat display elements such as liquid crystal cells. For example, in the case of a sulfonium salt, Ar/' (where X- is BF4- or PF6-
Still Ar-S"X AsF6- or 5bF6
-, Ar, Ar', Ar''Ar'' represents a monovalent aromatic hydrocarbon group. )ArgS+X--by force-
〉”, (Ar3.S”X)”2Ar”
-〉Ar -Ar Ar'+ZH-n ArH+Z'' Aromatic onium salt decomposes when irradiated with light, and H in the formula
A protonic acid having cationic polymerization ability indicated by X is released. This photodecomposition reaction occurs due to the absorption of ultraviolet light and visible light by the cation moiety exemplified by Arts+ in the formula. However, this cation part is J, V, Cr1vello
Report of et, al; Journal of Po
polymer Science Polymer Chem
istry Edition"17.977-999
(1979), the maximum absorption wavelength (the wavelength of the absorption peak apex is referred to as λmax; a single compound may have a plurality of wavelengths) is usually at a short ultraviolet wavelength of 300 nm or less.

For this reason, the bright line of a mercury lamp, which is a light source often used for photocuring, is the l line (365 nm) and the t i! i! (436nm
) and irradiation with argon laser, whose use has been considered in recent years, did not initiate cationic polymerization. Also, these λ
The molecular extinction coefficient ε of aromatic onium salt at max is 2
When considering the QOOO degree and the energy distribution in the wavelengths of various light sources, a large value was obtained.

For this reason, as an adhesive for glass cell sealing, which is one of the main uses of the present composition, it is recommended that the composition be cured for a long time by passing through soda glass, which absorbs most of the light of 300 nm or less. Light irradiation was necessary.

In some cases, 11111
11-17= Since a thick overlay was required, the attenuation of light inside the composition was large due to the above-mentioned size of ε, and therefore the amount of active species for cationic polymerization generated inside the composition was small. Therefore, there was a need for improvements that would fundamentally improve photosensitivity, such as poor internal curing properties, or increasing the amount of aromatic onium salts with the knowledge that this would increase the amount of eluted components. 0 It is known that a sensitizer (photosenaitizer) is used in photosensitive resins for the purpose of expanding the wavelength range to which they are sensitive. Most of these polymerization systems involve radicals, but S. P. Pappas et.
a 1'; “Photographic 5 cien
ce and Engineering ”23+(3
), 140 (1979) and U.S. Patent No. 4,06C
No. 4054.

The effectiveness of such addition of a sensitizer is not only limited to the above-mentioned curability and expansion of the photosensitive wavelength range, but also to the effective use of the photoinitiator within the composition. It is also effective from the point of view of reducing.

However, it has been found that in such a low molecular weight sensitizing system, the elution of the sensitizer itself, which is a low molecular weight compound, becomes a problem. In addition, when a sensitizer having a polymerizable substituent is used, the sensitizer is incorporated into the cured product through chemical bonding when the composition is cured by light irradiation. It was found that the elution of the sensitizer was at an extremely low level and did not increase over time.

The effect of adding a sensitizer in the composition of the present invention cannot be evaluated under appropriate conditions by simply examining the shortening of curing time, as used in the published literature, due to the above-mentioned elution problem. Here, the present inventors measured the temperature dispersion of the dynamic viscoelasticity of the cured film and evaluated the effectiveness of adding the sensitizer based on the Tg and molecular weight between crosslinking points of the cured product obtained. shows the relationship between the amount of sensitizer added, the Tg of the cured product, and the molecular weight between crosslinking points.

From FIG. 1, J and Tg increase and the molecule f(Me) between crosslinking points decreases by adding a sensitizer. The other curve has a maximum, and as the amount of sensitizer added further increases, Tg gradually decreases and M
c increases.

From this, it is clear that the addition of a sensitizer has the effect of improving the properties of the cured product. Furthermore, since excessive addition of a sensitizer deteriorates the properties of the cured product, it is clear that there is an appropriate range for the amount of sensitizer used.

On the other hand, the amount of eluted components was determined by an extraction test of the cured product. The relationship between the amount of sensitizer added and the amount of sensitizer eluted when the cured film obtained from the sensitizer was extracted is shown.

It is clear from FIG. 2 that the use of a sensitizer having a polymerizable substituent significantly reduces the elution of the sensitizer.

〔Example〕

Next, the present invention will be specifically explained with reference to examples, but the present invention is not limited only to these examples. In addition,
Parts in the examples are parts by weight.

Example 1 Molecular weight approximately 1.50 produced by anion living method
Epoxidized 1,2-2-liptadiene BF-1000 with an oxygen content of 7.7% (Adeka Argus) product name) 5
Alicyclic engineered poxy resin ER, which corresponds to the prison component like Part 0
50 parts of L-4299 (product name of U, C, C Company) are mixed well. Next, 1 part of triphenylsulfonium hexafluoroantimonate (50% propylene carbonate solution) as component (B) and vinylanthracene as sensitizer (C) component were added in the amounts shown in the following table, and kneaded well. and table-
Curable compositions (j-, A) to (,!7D) were obtained.

-21= Example 2 20.5 parts of methyleosin and 111 parts of epichlorohydrin were placed in a four-bottle flask equipped with a reflux condenser, a temperature needle, and a stirring device, and 5 parts of the solvent dimethylformamide were added.
0 parts, catalyst crown ether (15-crown −
5) After reacting at 80 U in the presence of 0.7 parts for 3 days, washing with water → extraction with diethyl ether → recrystallization, 19.5 parts of sensitizer methyleosine-glycidyl having a polymerizable substituent. Obtained ether.

Next, 100 parts of bisphenol A type epoxy resin epoxy resin having an epoxy equivalent of 175) YD-8125 (trade name of Tobu Kasei), 2 parts of triphenylphenacylphosphonium tetrafluoroborate (50% solution of propylene carbonate), and the method described above were added. Sensitizer methyleosin-glycidyl ether I with a polymerizable substituent synthesized in
10-2 parts of X were mixed and kneaded thoroughly to obtain a photocurable composition [2] of the present invention.

Comparative Example 1 A composition obtained by removing only the sensitizer vinylanthracene from the composition of Example 1 was thoroughly kneaded to obtain a photocurable composition [3] which was outside the scope of the claims of the present invention.

Comparative Example 2 The sensitizer vinyl anthracene having a polymerizable substituent was removed from the composition of Example 1, and the sensitizer anthracene not having a polymerizable substituent was substituted as shown in Table B below. The photocurable compositions (4-A) to (4-C) of Table B, which are outside the scope of the claims of the present invention, were obtained by adding the violet particles as shown and kneading them well.

Comparative Example 3 A composition obtained by removing only the sensitizer methyleosin-glycidyl ether from the composition of Example 2 was taken and thoroughly kneaded to obtain a photocurable composition [5] which deviates from the scope of the claims of the present invention.

Comparative Example 4 The sensitizer methyleosin-glycidyl ether having a polymerizable substituent was removed from the composition of Example 2 and replaced with the sensitizer methyleosin 1Xl without a polymerizable substituent.
0-2 parts was added and kneaded thoroughly to obtain a photocurable composition [6] which deviates from the scope of the claims of the present invention.

(1-A) obtained in Example 1.2 and Comparative Examples 1 to 4 above
)~('1-D], [2], [3], [4-A]~('
Curing properties and cured product properties 4 were measured using the compositions 4-C:], [5], and [6] in the following manner.

<Curing property measurement> Photocurable resin obtained in Examples and Comparative Examples [1-B]
, [2], [3], (4-, B), [5], and [6] were coated onto a JIS-G-3303 tin plate using a 6 m, IT doctor blade, and then heated using a high pressure mercury lamp (80 m).
A cured coating film was formed by irradiating light for a predetermined period of time from a distance of 10 crrL using a lens (W/cm), and the pencil hardness of the coating film was measured. The dynamic viscoelasticity measuring device Rheopipron DDV-1[1-EA
(manufactured by Toyo Baldwin), displacement ±0025 kaku,
Dynamic viscoelasticity was measured at a frequency of 35 Herz and a heating rate of 2°C/min, and the Tg and molecular weight between crosslinking points of the resulting cured product (where Tg is conveniently expressed as loss modulus (E >>)
Using the peak temperature of , the molecular cap between crosslinking points was determined from rubber elasticity theory. ), still, remove the above peeling film with THF.
Extraction was carried out at 0°C for 150 hours, GPC (Kell) 2-myesimine chromatography) analysis was performed, and the W detector peak height was determined. There is [:'1-A)~
(1-D:), according to the above method using [3] (however,
3.5 seconds of irradiation to form a cured coating film), calculate the Tg of the cured product and the molecular weight between crosslinking points, and calculate the amount of sensitizer added and the Tg of the cured product.
The relationship between the molecular weight and the molecular weight between crosslinking points is shown in FIG.

Furthermore, photocurable compositions containing a sensitizer vinyl anthracene having a polymerizable substituent and a sensitizer anthracene not having a polymerizable substituent and varying the amount thereof are used (1-A).
Using ~(1-D) and [4-A] ~ (4-C), the amount of sensitizer eluted from the cured product was measured according to the method described above (however, a cured coating film was formed by irradiation for 3.5 seconds). Figure 2 shows the relationship between the amount of sensitizer added and the amount of sensitizer eluted from the cured product.

<Measurement of liquid crystal cell sealing characteristics> Example 2 and Comparative Example 1.2 were applied to a glass plate that had been subjected to ion diffusion prevention treatment, electrode formation, and orientation treatment by a conventional method.
&r1-13), [3], and [4-B) in order to impart thixotropic properties to each composition, Aerosil +380'5 = 5 parts to 100 parts of flaky silica was added. and kneaded well to form a screen printing ink ([1-B]', [3]', (4-B) respectively).
) was applied to the outer periphery of the cell by screen printing. Next, the same treated glass plate used for the tip was placed on top and pressed and bonded. This was irradiated with light for a predetermined period of time from a distance of 10 cWL using a high-pressure mercury lamp (80 W/cm) in the crimped state to cure the composition. Next, the liquid crystal was sealed using a vacuum method.The cell manufactured in 1-B)' was filled with (1-B), below [3]' with [3], and [4-B]' with [4-B]. ] The liquid crystal injection port was sealed using the resin composition of
The composition was cured by irradiating it with light for a predetermined period of time from a distance of , thereby producing liquid crystal cells A to C. Next, performance tests such as sealing properties, high temperature and high temperature and high humidity durability, liquid crystal cell drive current value change rate, cold and heat cycle resistance, etc. were conducted for each sample A to C of the liquid crystal cells produced in this way. The results are shown in Table 2.

<Suitability for Metsuki Resist> [2] and [5] obtained in Example 2 and Comparative Example 3.4
], [6] was applied to a thickness of 30 μm on a Garaef IF substrate, and the composition was cured by irradiating it with light for a predetermined time at a distance of 10 crn using a high-pressure mercury lamp (80 W/cm). Product DF was obtained. This D-F sample was immersed in an electroless copper plating bath for 10 hours and 40°C, 95% R.
After HX 96 hours of moisture resistance, conductive ink was used to create a comb-shaped pattern! The turns were stamped and the surface resistance was measured. The results are shown in Table 3.

〔note〕

1) High-pressure mercury lamp (80W/tan), distance o: Initial current value of liquid crystal cell I^2 80℃, 90cm RH ) High pressure mercury lamp (80W/aa), distance 10cm
[Effects of the Invention] The photocurable composition obtained in the present invention is shown in Table 1 and Table 1.
As is clear from the figure, it has better curability and a higher Tg than the conventional photocationic system. Furthermore, the light wavelength range effectively used for photocuring is expanded to longer wavelengths. However, as is clear from Table 1 and Figure 2, the components eluted from the photocured product have been reduced, and Table 2 and Figure
From the table results, it is clear that the photocurable composition obtained in the present invention is useful as an insulating material, a resist material, and a sealing and sealing material.

[Brief explanation of drawings]

Figure 1 shows results obtained from viscoelasticity measurements of photocured products using photocurable compositions [1'-A) to (1-D] and [3] obtained in Examples and Comparative Examples of the present invention. The Tg and the molecular weight between crosslinking points (Mc) are plotted against the amount of sensitizer added. It is a figure in which the elution amount of the sensitizer obtained from the extraction test of the photocured material using A) to (4-C) is plotted against the amount of sensitizer added. In addition, in FIG. 2, for convenience, the extinction coefficient due to the difference in the sensitizer was corrected and expressed relatively by the GPC UV detector peak intensity.

Claims (1)

[Claims] (1) (A) 100 parts by weight of an epoxy resin, (B) 0.1 to 5 parts by weight of a photosensitive aromatic onium salt, and (C) 0.001 to 0.0 parts by weight of a sensitizer having a polymerizable substituent. A photocurable composition comprising 5 parts by weight as an essential component.