JP5397578B2 - Heat-resistant liquid phenol novolac resin, production method thereof and cured product thereof - Google Patents

Description

TECHNICAL FIELD The present invention relates to a liquid type phenol novolac resin composition capable of obtaining a cured product excellent in low hygroscopicity and heat resistance, a method for producing the same, and a cured epoxy resin product using the same. The present invention relates to a curing agent for semiconductor sealing that is suitable for a fixing material, and particularly suitable for semiconductor sealing materials such as flip chip mounting and chip size packages.
The heat-resistant liquid phenol novolac resin of the present invention can be used as a raw material for epoxidized novolac resin, in addition to being used as a curing agent for epoxy resins in various binders, compounds, coating materials, laminates, molding materials, and the like. it can.

Conventionally, in the field of electronic materials, especially semiconductor (IC) sealing, resin sealing has been the mainstream in terms of productivity, cost, etc., and it has excellent workability, moldability, electrical properties, moisture resistance, mechanical properties, etc. Therefore, at present, epoxy resin compositions are mainly used. Examples of the curing agent include phenol novolac resins, various amines, and acid anhydrides. In particular, phenol novolac resins are mainly used for semiconductor (IC) sealing in terms of heat resistance and reliability. .
In recent years, further downsizing, multi-functionalization of electronic devices, and high integration of semiconductors (ICs) have been remarkably accelerated, and the conventional mounting method for mounting a package on a printed wiring board (PCB) is also the conventional pin insertion. From the method (DIP) to the surface mounting method (BGA, SOP, SiP, CSP) has become mainstream. Further, the flip chip mounting method has begun to be applied as an effective mounting technique for high-density mounting, and is also being used as a sealing material for these.
These are liquid epoxy resins and curing agents such as liquid acid anhydrides, amines, amides, etc., and phenol novolac curing agents are used as semi-solid to solid phenol novolac resins or phenol novolac resins dissolved in solvents. Yes. Sealants using such semi-solid to solid phenol novolac resins are naturally poor in fluidity, and those using solvents have a negative effect on performance because the solvent is included in the sealant after curing. Effect.
It has also been attempted to construct a solvent-free encapsulant using acid anhydride, but the cured encapsulant undergoes hydrolysis in the presence of hot water, for example, pressure cooker test conditions. Since the generated acid corrodes metal substrates such as aluminum and wiring, the moisture resistance life is reduced. Also, amine and amide groups are not preferable from the viewpoint of reliability because they have strong activity.
Furthermore, a heat-resistant liquid phenol novolac resin in which an imide compound is contained in a liquid phenol novolak resin is disclosed (Patent Document 1), but it cannot be said that the fluidity is sufficient.

Japanese Patent Laid-Open No. 2001-214028

  An object of the present invention is to provide a liquid type phenol novolac resin composition that solves the above conventional problems and exhibits fluidity, hygroscopicity, and heat resistance suitable for sealing in the presence of no solvent or a small amount of solvent. It is to provide.

  As a result of intensive studies to achieve the above object, the present inventor has a fluidity, low hygroscopicity, heat resistance, mechanical properties, by dissolving a specific solid phenol novolac resin in a liquid phenol novolac resin. The present inventors have found a liquid phenol novolac resin excellent in curing characteristics with an epoxy resin and have reached the present invention.

That is, an object of the present invention is to provide a heat-resistant liquid in which a solid phenol novolac resin represented by the following general formula (2) and / or general formula (3) is dissolved in a liquid phenol novolac resin represented by the general formula (1). Solved by phenol novolac resin.

（式中ｎは、平均重合度０〜５で、Ｒ１、Ｒ２、Ｒ３、Ｒ４、Ｒ５は同一でも異なっていてもよく、水素又は炭素原子数１〜４の直鎖又は分岐状のアルキル基、又はアリール基を示す。）

(In the formula, n is an average degree of polymerization of 0 to 5, and R1, R2, R3, R4, and R5 may be the same or different, and are hydrogen or a linear or branched alkyl group having 1 to 4 carbon atoms, Or an aryl group.)

（式中ｎは、平均重合度０〜５を示す。）

(In the formula, n represents an average degree of polymerization of 0 to 5.)

（式中ｎは、平均重合度０〜５を示す。）

(In the formula, n represents an average degree of polymerization of 0 to 5.)

  Further, the present invention is characterized in that the liquid phenol novolac resin represented by the general formula (1) is melt-mixed with the solid phenol novolac resin represented by the general formula (2) and / or the general formula (3). This is a method for producing a heat-resistant liquid phenol novolac resin.

  The heat-resistant liquid phenol novolac resin obtained in the present invention is not only excellent in fluidity, low moisture absorption, heat resistance, mechanical properties, and curing properties with epoxy resins, but also used as a raw material for epoxidized novolac resins. it can.

  Hereinafter, the present invention will be described in detail.

In the liquid phenol novolak resin represented by the general formula (1) used in the present invention, R1 to R5 are hydrogen, an alkyl group having 1 to 4 carbon atoms or an aryl group, and may be the same or different. A liquid phenol novolak resin in which the ortho position of R5 is an aryl group and R2 to R4 are hydrogen atoms is preferably used.
N which shows an average degree of polymerization exhibits a liquid state at 25 degreeC, and is 0-5 from a viewpoint of viscosity reduction, 0-3 are preferable and 0-2 are more preferable. Further, from the same viewpoint, the weight average molecular weight of the liquid phenol novolak resin represented by the general formula (1) is preferably 800 or less, and more preferably less than 600.
As solid phenol novolak resin shown by the said General formula (2), the average polymerization degree n is 0-5 from a viewpoint of low viscosity, 0-3 are preferable, and 0-2 are more preferable. Further, from the same viewpoint, the weight average molecular weight of the solid phenol novolak resin represented by the general formula (2) is preferably 800 or less, and more preferably less than 600.
Furthermore, as solid phenol novolak resin shown by the said General formula (3), the average degree of polymerization n is 0-5 from a viewpoint of low viscosity, 0-3 are preferable, and 0-2 are more preferable. From the same viewpoint, the weight average molecular weight of the solid phenol novolac resin represented by the general formula (3) is preferably 900 or less, and more preferably less than 800.
Here, the weight average molecular weight means a weight average molecular weight in terms of polystyrene by GPC analysis.

To form the heat-resistant liquid phenol novolak resin of the present invention, the solid phenol novolak represented by the general formula (2) and / or the general formula (3) in the liquid phenol novolak resin represented by the general formula (1). It is manufactured by dissolving the resin.
Although there is no restriction | limiting in particular as a method to melt | dissolve, the solid phenol novolak resin shown by General formula (2) and / or General formula (3) is melt-mixed in the liquid phenol novolak resin shown by the said General formula (1) This method is simple and preferable.
A method of dissolving the solid phenol novolak resin represented by the general formula (2) and / or the general formula (3) in an organic solvent and mixing with the liquid phenol novolak resin represented by the general formula (1) is also conceivable. It is necessary to consider the point to remove.

  Although the melt mixing temperature in the production method of the present invention depends on the melting point of the solid phenol novolac resin represented by the general formula (2) and / or the general formula (3), it is usually 40 to 250 ° C., 50 to 200 degreeC is preferable and 70 to 170 degreeC is more preferable.

  Moreover, although the melt mixing time in the manufacturing method of this invention is based also on the temperature, it is normally performed within 10 hours.

  The liquid phenol novolak resin of the general formula (1) and the resulting heat-resistant liquid phenol novolak resin used in the present invention are in a liquid state at 25 ° C., and about 1.2 ml of a sample is subjected to an E-type viscometer (Toki The value of the rotational viscosity measured at 25 ° C. using an industrial) is 200 Pa · s or less, preferably 100 Pa · s or less, more preferably 80 Pa · s or less, still more preferably 60 Pa · s or less, most preferably 40 Pa · s or less.

The heat-resistant liquid phenol novolak resin obtained in the present invention has no problem as long as it is liquid at 25 ° C. or has a viscosity of 200 Pa · s or less. The liquid phenol resin represented by the general formula (1) and the general formula (2 ) And / or the ratio of use with the solid phenol novolac resin represented by the general formula (3) is not particularly limited.
However, in consideration of the properties of the individual phenol resins, the solid phenol novolac resin represented by the general formula (2) and / or the general formula (3) with respect to 100 parts by weight of the liquid phenol resin represented by the general formula (1). Is preferably used in an amount of 1 to 40 parts by weight.
In particular, in consideration of fluidity characteristics and heat resistance, the solid phenol novolac resin represented by the general formula (2) and / or the general formula (3) with respect to 100 parts by weight of the liquid phenol resin represented by the general formula (1). Is preferably 1 to 35 parts by weight, more preferably 2 to 30 parts by weight, and most preferably 4 to 30 parts by weight.
In addition, the solid phenol novolac resins represented by the general formula (2) and the general formula (3) used in the present invention may be used alone or in combination of two or more, as long as they are within the allowable usage range. There is no problem.

  The heat-resistant liquid phenol novolak resin obtained in the present invention can be used as it is as a curing agent for epoxy resins in binders, coating materials, laminates, molding materials, etc., and by reacting with epichlorohydrin and epoxy resin. You can also Furthermore, it can also be set as the hardened | cured material using these.

  When the heat-resistant liquid phenol novolac resin of the present invention is used as a curing agent for epoxy resins, the phenol novolac resin, the epoxy resin and the curing accelerator are mixed in a predetermined amount and cured in a temperature range of 100 ° C to 250 ° C. .

Examples of the epoxy resin used include glycidyl ether type epoxy resins such as bisphenol A type epoxy resin, bisphenol F type epoxy resin, cresol novolac type epoxy resin, phenol novolac type epoxy resin, triphenolmethane type epoxy resin, and biphenyl type epoxy resin. And epoxy resins having two or more epoxy groups in the molecule, such as glycidyl ester type epoxy resins, glycidyl amine type epoxy resins, and halogenated epoxy resins. These epoxy resins may be used alone or in combination of two or more.
Preferred epoxy resins include bisphenol A type epoxy resins and bisphenol F type epoxy resins in a liquid state at 25 ° C. from the viewpoint of lowering the viscosity.

  As a hardening accelerator, the well-known hardening accelerator for hardening an epoxy resin with a phenol novolak resin can be used. Examples thereof include organic phosphine compounds and their boron salts, tertiary amines, quaternary ammonium salts, imidazoles and tetraphenylboron salts thereof, among which 25 ° C. from the viewpoint of curability and low viscosity. In liquid, 2-ethyl-4-methylimidazole in a liquid state is preferable.

Regarding the method of reacting the heat-resistant liquid phenol novolak resin of the present invention with epichlorohydrin to form an epoxy resin, for example, an excess of epichlorohydrin is added to the phenol novolac resin and an alkali metal hydroxide such as sodium hydroxide or potassium hydroxide is added. In the presence of, a method of reacting in the range of 50 to 150 ° C., preferably 60 to 120 ° C. for about 1 to 10 hours can be mentioned. In this case, the usage-amount of epichlorohydrin is 2-15 times mole with respect to the hydroxyl equivalent of this phenol novolak resin, Preferably it is 2-10 times mole. Moreover, the usage-amount of the alkali metal hydroxide to be used is 0.8-1.2 times mole with respect to the hydroxyl equivalent of this phenol novolak resin, Preferably it is 0.9-1.1 times mole.
Regarding post-treatment after the reaction, excess epichlorohydrin is distilled off after completion of the reaction, the residue is dissolved in an organic solvent such as methyl isobutyl ketone, filtered, washed with water to remove inorganic salts, and then the organic solvent is distilled off. By leaving, the target epoxy resin can be obtained.

  The epoxy resin thus obtained and the phenol novolac resin can be used as a curing agent to form a new epoxy resin composition.

  The obtained epoxy resin composition can be used by adding or reacting in advance with an inorganic filler, a release agent, a colorant, a coupling agent, a flame retardant, or the like, if necessary. In particular, when used for semiconductor sealing applications, the addition of an inorganic filler is essential. Examples of such inorganic fillers include amorphous silica, crystalline silica, alumina, calcium silicate, calcium carbonate, talc, mica, barium sulfate, etc., and particularly amorphous silica and crystalline silica. Etc. are preferable. Moreover, the mixture ratio of these additives may be the same as the ratio in the well-known epoxy resin composition for semiconductor sealing.

The heat-resistant liquid phenol novolak resin obtained in the present invention can be used as a curing agent for sealing a semiconductor device, and can be used as a sealing material for a semiconductor device by converting the phenol resin into an epoxy resin. Furthermore, it can also be used as a sealing material for semiconductor devices as an epoxy resin composition containing the phenol resin and the obtained epoxy resin.
Available semiconductor devices include lead frames, wiring boards, glass, silicon webs, and other active elements such as semiconductor chips, transistors, diodes, light emitting diodes, thyristors, capacitors, resistors, resistor arrays, coils, switches, etc. Examples include electronic components equipped with passive elements.

Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples. However, the present invention is not limited to these examples. In the text, “parts” indicates parts by weight.

Reference example 1
<Synthesis of liquid phenol novolac resin A represented by the general formula (1)>
In a glass flask having a capacity of 1000 parts by volume equipped with a thermometer, charging / distilling outlet, condenser and stirrer, 536 parts (4.0 mol) of o-allylphenol, 57.1 parts (0.8 mol) of 42% formalin , And 5.4 parts of oxalic acid were placed in a four-necked flask, reacted at 100 ° C. for 5 hours, dehydrated by raising the temperature to 160 ° C., and then unreacted components were removed at a reduced pressure of 40 torr. The rotational viscosity of the obtained liquid phenol novolac resin was 1.7 Pa · s (25 ° C.). The number average molecular weight (Mn) in terms of polystyrene by gel permeation chromatographic analysis (hereinafter sometimes abbreviated as GPC) was 496, and the weight average molecular weight (Mw) was 541.

Reference example 2
<Synthesis of solid phenol novolac resin represented by the general formula (2)>
400 parts phenol (4.26 mole), 46.84 parts salicylaldehyde (0.38 mole), and paratoluene in a 1000-volume glass flask equipped with a thermometer, charging / distilling outlet, condenser and stirrer 1 part of sulfonic acid was placed in a four-necked flask, reacted at 130 ° C. under a nitrogen stream, and cooled to 95 ° C. After neutralization with a 25% aqueous sodium hydroxide solution, 400 parts of pure water of 90 ° C. or higher was added and washed with water. Thereafter, the internal temperature was raised to 150 ° C., and unreacted components were removed by a reduced pressure-steaming treatment. The obtained resin was solid at 25 ° C., and the melt viscosity at 150 ° C. of the resin was 0.9 Pa · s. The number average molecular weight (Mn) in terms of polystyrene by GPC analysis was 554, and the weight average molecular weight (Mw) was 616.

Example 1
<Synthesis of heat-resistant liquid phenol novolac resin>
In a glass flask having a capacity of 500 parts by volume, 100 parts of the liquid phenol novolac resin A of the general formula (1) synthesized in Reference Example 1 and the solid phenol novolac resin of the general formula (2) synthesized in Reference Example 2 above. 4.2 parts was added, and the mixture was stirred at 120 ° C. for 2 hours under a nitrogen stream to obtain a heat-resistant liquid phenol novolac resin. The rotational viscosity of the obtained heat-resistant liquid phenol novolac resin was 3.0 Pa · s (25 ° C.). The number average molecular weight (Mn) in terms of polystyrene by GPC analysis was 498, and the weight average molecular weight (Mw) was 546.

Examples 2-4, Comparative Example 1
It carried out similarly to Example 1 in the composition ratio shown in Table 1 and Table 2.
The physical property values of the obtained resin are shown in Tables 1 and 2.

Reference example 3
<Synthesis of solid phenol novolac resin represented by the general formula (3)>
400 parts phenol (4.26 mol), 406.9 glyoxal 86.9 parts (0.60 mol), and paraffin in a 1000-volume glass flask equipped with a thermometer, charging / distilling outlet, condenser and stirrer One part of toluenesulfonic acid was put into a four-necked flask, reacted at 120 ° C. under a nitrogen stream, and cooled to 80 ° C. After neutralization with a 25% aqueous sodium hydroxide solution, 400 parts of pure water of 90 ° C. or higher was added and washed with water. Thereafter, the internal temperature was raised to 180 ° C., and unreacted components were removed by a reduced pressure-steaming treatment. The obtained resin was solid at 25 ° C., and the melt viscosity at 200 ° C. of the resin was 20 Pa · s. The number average molecular weight (Mn) in terms of polystyrene by GPC analysis was 580, and the weight average molecular weight (Mw) was 746.

Example 5
<Synthesis of heat-resistant liquid phenol novolac resin>
100 parts of the liquid phenol novolac resin A synthesized in Reference Example 1 and 4.2 parts of the solid phenol novolac resin synthesized in Reference Example 3 were added to a glass flask having a capacity of 500 parts by volume, and the mixture was added at 170 ° C. for 2 hours under a nitrogen stream. The mixture was stirred to obtain a heat-resistant liquid phenol novolac resin. The rotational viscosity of the obtained heat-resistant liquid phenol novolac resin was 2.9 Pa · s (25 ° C.). The number average molecular weight (Mn) in terms of polystyrene by GPC analysis was 509, and the weight average molecular weight (Mw) was 589.

Examples 6-7, Comparative Examples 2-3
It carried out similarly to Example 5 in the composition ratio shown in Table 1 and Table 2.
The physical property values of the obtained resin are shown in Tables 1 and 2.

Example 8
<Synthesis of heat-resistant liquid phenol novolac resin>
In a glass flask having a capacity of 500 parts by volume, 100 parts of the liquid phenol novolac resin A synthesized in Reference Example 1 above, 11.4 parts of the solid phenol novolac resin synthesized in Reference Example 2 above, and solid phenol synthesized in Reference Example 3 above 11.4 parts of novolak resin was added and stirred at 170 ° C. for 2 hours under a nitrogen stream to obtain a heat-resistant liquid phenol novolak resin. The rotational viscosity of the obtained heat-resistant liquid phenol novolac resin was 45.9 Pa · s (25 ° C.). The number average molecular weight (Mn) in terms of polystyrene by GPC analysis was 523, and the weight average molecular weight (Mw) was 634.

Reference example 4
<Synthesis of liquid phenol novolac resin B represented by the general formula (1)>
In a glass flask with a capacity of 1000 parts by volume equipped with a thermometer, charging / distilling outlet, condenser and stirrer, 536 parts of o-allylphenol (4.0 moles), 22.9 parts of 42% formalin (0.32 moles) And 5.1 parts of oxalic acid were placed in a four-necked flask, reacted at 100 ° C. for 5 hours, dehydrated by raising the temperature to 160 ° C., and then unreacted components were removed at a reduced pressure of 40 torr. The rotational viscosity of the obtained liquid phenol novolac resin was 0.9 Pa · s (25 ° C.). The number average molecular weight (Mn) in terms of polystyrene by gel permeation chromatographic analysis (hereinafter sometimes abbreviated as GPC) is 465, the weight average molecular weight (Mw) is 495, and the average value of the repeating unit n is 0.2. Met.

Example 9
<Synthesis of heat-resistant liquid phenol novolac resin>
100 parts of the liquid phenol novolac resin B produced in Reference Example 4 and 22.7 parts of the solid phenol novolac resin A synthesized in Reference Example 2 were added to a glass flask having a capacity of 500 parts by volume under a nitrogen stream. The mixture was stirred at 0 ° C. for 2 hours to obtain a heat-resistant liquid phenol novolac resin. The rotational viscosity of the obtained heat-resistant liquid phenol novolac resin was 16.6 Pa · s (25 ° C.). The number average molecular weight (Mn) in terms of polystyrene by GPC analysis was 483, and the weight average molecular weight (Mw) was 526.

Examples 10-11, Comparative Example 4
It carried out similarly to Example 9 in the composition ratio shown in Table 1 and Table 2.
The physical property values of the obtained resin are shown in Tables 1 and 2.

In addition, the analysis method of resin obtained by this invention and a hardening | curing agent is as follows.
Phenol novolac resin (1), gel permeation chromatographic analysis: GPC measurement method ・ Model: HLC-8220, manufactured by Tosoh Corporation ・ Column: TSK-GEL H type
G2000H × L 4
1 G3000H x L
G4000H × L 1 ・ Measurement condition: Column pressure 13.5 MPa
-Solution: Tetrahydrofuran (THF)
-Flow rate: 1 ml / min.
・ Measurement temperature: 40 ℃
・ Detector: Spectrophotometer (UV-8020)
・ RANGE: 2.56 WAVE LENGTH 254nm & RI
(2), ICI viscosity • Set the plate temperature of the ICI cone plate viscometer to 150 ° C.
・ Select the cone to be used according to the sample viscosity.
Place the sample on the center of the hot plate at 150 ° C., and further contact the cone on it.
・ 90 sec. Turn on the motor switch and read the value when the indicated value is stable.
-The average value of n = 2 is taken as the viscosity value.
(3), rotational viscosity (E-type viscosity)
-About 1.2 ml of sample is put in a cup and measured using an E-type viscometer (manufactured by Toki Sangyo Co., Ltd.).
・ Read the value when the indicated value is stable.
(4), OH equivalent (Outline: Method of acetylating with acetyl chloride, decomposing excess acetyl chloride with water and titrating with alkali)
-Weigh accurately 1 g of sample, add 1,4-dioxane; 10 ml and dissolve.
-After confirming dissolution, add 1.5 ml / L acetyl chloride / anhydrous toluene solution; 10 ml, and cool to 0 ° C.
・ Pyridine; 2 ml was added and 1 Hr. In a water bath at 60 ± 1 ° C. React.
-After the reaction, cool and add pure water; 25 ml, and mix well to decompose acetyl chloride.
Add acetone; 25 ml, phenolphthalein.
-Titration is performed using 1 mol / L-potassium hydroxide until the sample solution turns reddish purple.
・ Measure the blank (no sample) at the same time by the above operation.
Calculate by the following formula.
OH equivalent [g / eq. ] = (1000 × W) / (f × (BA))
Where W: sample weight [g]
f: Factor of 1 mol / L-potassium hydroxide = 1.000
B: 1 mol / L-potassium hydroxide amount [ml] required for blank measurement
A: 1 mol / L-potassium hydroxide amount [ml] required for sample measurement

Hardener (5), water absorption measurement 150 ° C. × 5 Hr. + 180 ° C. × 8 Hr. And cast to the following size.
Size: (φ50 ± 1) × (3 ± 0.2) (diameter × thickness: mm)
・ Wipe the surface well and measure the sample weight.
• Place in a 100 ml sample bottle and add 80 ml of pure water.
・ 95 ° C. × 24 Hr. In a hot air circulation dryer. Absorb water.
-24Hr. After that, it is taken out from the dryer, immersed in a low temperature constant temperature water bath and cooled to 25 ° C.
・ After cooling, wipe off the water adhering to the surface and measure the weight.
・ Calculate the water absorption rate by the following formula.
Water absorption [%] = ((B−A) / A) × 100
A: Weight before water absorption [g]
B: Weight after water absorption [g]
(6) Measurement of glass transition temperature (Tg) 150 ° C. × 5 Hr. + 180 ° C. × 8 Hr. The sample cast and cured with is cut into the following sizes.
Size: (50 ± 1) × (40 ± 1) × (100 ± 1) (length × width × height; mm)
Measurement device; the sample was set in TMA-60 (manufactured by SHIMADZU), measured in an _{N 2} atmosphere.
-Temperature rising rate: 3 ° C / min. Measured to 350 ° C., the temperature of the inflection point is obtained and set as the glass transition temperature (Tg).
(7), cured product mechanical properties (elastic modulus / displacement / stress / strain) measurement / 150 ° C. × 5 Hr. + 180 ° C. × 8 Hr. The sample cast and cured with is cut into the following sizes.
・ Size: (75 ± 1) × (6 ± 1) × (4 ± 1) (length × width × thickness: mm)
・ Measuring device: Autograph (Model: AG-5000D manufactured by SHIMADZU)
Head speed: 2 mm / min. Distance between two points: 50 mm A compression bending test is performed at room temperature.

  The physical properties of the phenol novolak resins synthesized in Reference Examples 1 to 4 are shown in Table 2.

Each phenol novolak resin synthesized in Table 1 and Table 2 is used as a curing agent, and as an epoxy resin, Epicoat 828EL (bisphenol A type liquid epoxy resin, epoxy equivalent 186 g / eq) manufactured by Japan Epoxy Resin Co., Ltd. is used as a curing accelerator. 2E4MZ (2-ethyl-4-methylimidazole) manufactured by Kasei Corporation was used. Blended at the same equivalent ratio as the above epoxy resin, heated to 150 ° C, melted and mixed, cast into a mold heated to 150 ° C after vacuum defoaming, and cured at 150 ° C for 5h and at 180 ° C for 8h. An epoxy resin cured product was obtained. Table 3 and Table 4 show the blending and physical properties of the obtained cured epoxy resin.
In the present invention, a phenol novolak resin having both heat resistance and fluidity is produced by a simple method by melt-mixing a liquid phenol novolak resin synthesized in advance and a specific solid phenol novolak resin at a specific ratio. Can do.

Claims (8)

In the liquid phenol novolac resin represented by the following general formula (1),

(In the formula, n represents an average degree of polymerization of 0 to 5, R ₁ represents an allyl group, and R ₂ , R ₃ , R ₄ , and R ₅ represent hydrogen or a linking group CH _2. )
The solid phenol novolak resin represented by the following general formula (2) and / or general formula (3) is dissolved,

(In the formula, n represents an average degree of polymerization of 0 to 5.)

(In the formula, n represents an average degree of polymerization of 0 to 5.)
The solid phenol novolac resin represented by the general formula (2) and / or the general formula (3) is composed of 1 to 40 parts by weight with respect to 100 parts by weight of the liquid phenol novolak resin represented by the general formula (1). A heat-resistant liquid phenol novolak resin characterized by having a rotational viscosity at 200 Pa · s or less.   The heat-resistant liquid phenol novolak resin according to claim 1, wherein the solid phenol novolak resin represented by the general formula (2) and / or the general formula (3) is melt-mixed and dissolved.   The solid phenol novolac resin represented by the general formula (2) and / or the general formula (3) is melt-mixed with the liquid phenol novolak resin represented by the general formula (1). The manufacturing method of the heat-resistant liquid phenol novolak resin of any one.   The hardening | curing agent for epoxy resins containing the heat-resistant liquid phenol novolak resin of any one of Claims 1-2, or the heat-resistant liquid phenol novolak resin obtained by the manufacturing method of Claim 3.   An epoxidized novolak resin obtained by epoxidizing the heat-resistant liquid phenol novolak resin according to any one of claims 1 to 2 or the heat-resistant liquid phenol novolak resin obtained by the production method according to claim 3.   The heat-resistant liquid phenol novolak resin according to any one of claims 1 to 2 or the heat-resistant liquid phenol novolak resin obtained by the production method according to claim 3 and any one of claims 1 to 2. An epoxy resin composition comprising the heat-resistant liquid phenol novolak resin according to claim 3 or an epoxidized novolac resin obtained by epoxidizing the heat-resistant liquid phenol novolak resin obtained by the production method according to claim 3.   Hardened | cured material using the epoxy resin composition of Claim 6.   A semiconductor device comprising the cured product according to claim 7.