JPS6155113A - Cresol novolak epoxy resin and its production - Google Patents

Abstract

PURPOSE:To obtain the titled linear high-MW resin which can give a cured product excellent in heat resistance, flexibility and impact resistance, by reacting a specified linear high-MW cresol novolak resin with an epihalohydrin in the presence of an alkali metal hydroxide. CONSTITUTION:1mol of cresol (mixture) comprising 10-1mol of o-cresol and 0- 9mol of p-cresol is polycondensed with 0.7-1.mol of HCHO or a compound which generates HCHO upon heat decomposition, such as trioxane, at 95 deg.C or above in the presence of 0.01-20pts.wt., per 100pts.wt. cresol, acidic catalyst in 150-300pts.wt., per 100pts.wt. cresol, solvent such as a 3-12C aliphatic alcohol to obtain a linear high-MW cresol novolak resin having a softening point >=120 deg.C and a number-average MW>=1,500 (as determined in N,N-dimethylacetamide by a vapor pressure method). This resin is reacted with an excess of an epihalohydrin at 60-150 deg.C in the presence of an alkali metal hydroxide to obtain the titled linear high-MW resin having an epoxy equivalent weight of 176- 280, a number-average MW>=2,000 (as determined by the above method) and a softening point of 100-300 deg.C.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a high molecular weight cresol novolak epoxy resin suitable for casting materials, resin faces for reinforcing glass fibers, and resins for powder coatings, and a method for producing the same. Since the cured product of the resin of the present invention has high heat resistance and mechanical strength, the resin of the present invention is useful as an electrical equipment sealant and an aircraft structural material.

[Conventional technology]

Epoxy resins have excellent heat resistance, mechanical strength, and electrical properties, and are therefore widely used in fields such as paints, electrical insulation materials, casting materials, and structural materials.

These epoxy resins are generally bisphenol diglycidyl ethers produced from bisphenol A and epichlorohydrin and having about two epoxy groups in one molecule (Japanese Patent Laid-Open No. 55-11892.0,
No. 58-74726, No. 58-7472.7, Special Publication No. 32. -1548, British Patent No. 1.001,364
In recent years, with the development of small electrical products, LSIs, ICs, and aerospace equipment, epoxy resins that provide cured products with higher heat resistance and mechanical strength are required. The so-called polyfunctional epoxy resins having the following groups came into use.

When a polyfunctional epoxy resin is used, mechanical properties and electrical properties are improved because the crosslinking density increases after the curing reaction. Examples of such polyfunctional epoxy resins include tetraepoxide of methylene dianiline, tetraepoxide of diaminodiphenylmethane, Tetraglycidyl ether of tetraphenolethane is known, but these epoxy resins have a low molecular weight, the number of epoxy groups in the molecule is at most 4, and the heat resistance temperature is only a cured product slightly over 200°C. Not obtained. Furthermore, epoxy resins having amino groups in the molecule have poor storage stability, tend to gel, and have the disadvantage of high water absorption.

Furthermore, as a polyfunctional epoxy resin, polyepoxide of phenol novolak resin (for example, Epicoat 154) is used.
oil-based shell epoxy (trade name), ortho-cresol novolak resin polyepoxide (e.g. BOCNI 04
Products such as 8 Nippon Kayaku (trade name) have been put to practical use in insulating paints, semiconductor encapsulation materials, FRTP structural materials, printed wiring boards, etc. that require heat resistance and high strength. The number average molecular weight of the phenol novolak or cresol novolak, which is the raw material for these epoxy resins, is Fi2so~1,000, and is represented by the following formula: ] Since the epoxy resin has trinuclear to pentanuclear bodies, the number of molecular bones of this epoxy resin is about 1,400 at most. Therefore, the heat resistance temperature of cured products of these epoxy resins is at most 2.00°C, and the reality is that epoxy resins with higher heat resistance are desired.

[Problem that the invention seeks to solve]

An object of the present invention is to provide a polyfunctional epoxy resin that has heat resistance of 230° C. or higher and provides a cured product with excellent mechanical strength.

[Means for solving problems]

In order to improve the heat resistance of the cured product, the present inventor filed an application based on the knowledge that if the raw material cresol novolac is more polynuclear, an epoxy resin with more epoxy groups can be obtained. It is soluble in organic solvents such as ethers and ketones, has a number average molecular weight of 1,500 or more, and has a softening point of 12
Linear Novo2 Tsuku Resin (Patent Application 1987-1165)
No. 10, No. 59-131864) is used as a polyphenol raw material, and by reacting it with epichlorohydrin in the presence of caustic soda, an epoxy resin that provides a cured product with excellent heat resistance, which is the object of the present invention, can be obtained. Can be provided.

[Structure of the invention]

The first aspect of the present invention is that the epoxy equivalent is 176 to 280.
Number average molecular weight measured by vapor pressure method in D,N,N-dimethylacetamide solvent is 2,000-7, Q OO
The present invention provides a linear high molecular weight cresol novolak epoxy resin.

The second aspect of the present invention is a linear high molecular weight cresol novolac resin having a softening point of 120° C. or higher and a number average molecular weight of 1,500 or higher as measured by vapor pressure method in an N,N-dimethylacetamide solvent. Epoxy equivalent is 176-2 by reacting shrimp halohydrin in the presence of an alkali metal hydroxide.
The present invention provides a method for producing a linear high molecular weight cresol novolak epoxy resin having a number average molecular weight of 2,000 or more as measured by vapor pressure method in a fi, N, N-dimethylacetamide solvent.

(Cresol novolac resin) Cresol novolac resin, which is a raw material for epoxy resin, is made of ortho-cresol or ortho-cresol and para-cresol in a molar ratio of 1 as described in the specification of the earlier application.
Mixed cresol and aldehyde mixed at a ratio of 020 to 1:9 are mixed into aliphatic alcohol having 3 to 12 carbon atoms, glycol ether having 3 to 6 carbon atoms, benzyl alcohol and 2 to 6 carbon atoms. υ by polycondensation of aliphatic carboxylic acids in the presence of an acidic catalyst in a selected solvent.
The obtained linear polymer has a softening point of 120° C. or higher and a number average molecular weight of 1500 or higher as measured by vapor pressure method in an N,N-dimethylacetamide solvent.

(Cresol) Even if the cresol to be reacted with the aldehyde is orthocresol alone, it is less than 90 mol%, preferably 3
0 to 70 mol% may be replaced with para-cresol.

The use of para-cresol contributes to improving the heat resistance of the resin, but reduces the solubility of the resin in solvents.

(Aldehyde) As the aldehyde, trioxane or paraformaldehyde, which generates cyformaldehyde by thermal decomposition, is used.

In particular, trioxane or paraformaldehyde is preferred in order to reduce the water content in the reaction system.

For 1 mole of phenols, formaldehyde is 0.
It is used in a proportion of 7 to 1.5 mol, preferably 0.9 to 1.3 mol. If the aldehyde content is low, only a low molecular weight cresol novolac resin can be obtained. Moreover, if a large amount is used, the resin tends to gel.

(Solvent) The alcohol used as the reaction solvent is suitably one with a high boiling point and good solubility for the novolak resin, such as l,7' lobanol, butanol, amyl alcohol, hexanol, methoxyethanol, ethoxyethanol, butoxyethanol, etc. Glycol ethers, benzyl alcohol, etc.

Examples of organic carboxylic acids include formic acid, acetic acid, propionic acid, butyric acid, and the like.

The solvent is 150 to 30 parts by weight per 100 parts by weight of cresol.
It is used in a proportion of 0 parts by weight.

(Acidic Catalyst) As the catalyst, protonic acids such as hydrochloric acid, nitric acid, sulfuric acid, phosphoric acid, toluenesulfonic acid, oxalic acid, methanesulfonic acid, and perchloric acid are used. JP-A-57-113, JP-A No. 56-
Boron trifluoride, which is preferred in Publication No. 92908,
Lewis acids such as boron trifluoride ether complex, ternary trifluoride diamium, tin tetrachloride, and zinc chloride are unsuitable.

The catalyst is 0.01 to 2 parts by weight per 100 parts by weight of cresol.
It is used in an amount of 0 parts by weight, preferably 1 to 15 parts by weight.

(Polycondensation reaction) The reaction can be carried out by: ■Pour the raw materials cresol, aldehyde, solvent, and catalyst into a reaction container and slowly heat them without stirring to reach the reaction temperature, or ■Cresol raw materials and the reaction solvent. After charging the catalyst and the reaction temperature, add a solution of the aldehyde and the catalyst in an alcohol or carboxylic acid solvent, or charge the raw materials cresol, aldehyde, and solvent into a reaction vessel and react while stirring. Either heat it to near temperature and dropwise drop a solvent in which the catalyst or acid catalyst is dissolved.

When producing a random copolymer resin of ortho-cresol and para-cresol, it is necessary to thoroughly mix both cresols in advance.

The reaction is carried out at 95°C or higher, preferably ilo, 5°C to 150°C.
It will be held at At low temperatures, the reaction progresses slowly, and at high temperatures, gel components are likely to occur.

If there is a lot of water in the reaction system, formaldehyde will be consumed in side reactions, the amount used for polymerization will decrease, and the molecular weight will not increase. Furthermore, if the polymer 11 novolak resin has a high water content, it will become insoluble in the solvent and will precipitate, resulting in a heterogeneous reaction, making it difficult to form into a polymer. The reaction is carried out at a water content of 15% by weight or less, preferably 10% by weight or less. It is also effective to carry out the reaction using a solvent such as n-butanol, which is azeotropic with water and can be separated, while refluxing to remove water produced along with the reaction.

(Purification) After the completion of the reaction, separation of the cresol novolac resin can be performed using a water-soluble solvent such as methoxyethanol, ethoxyethanol, acetic acid, formic acid, etc.
Pour into ~20 times the volume of water and re-precipitate and recover as a water-insoluble resin. Further, when a water-insoluble solvent is used as the solvent, the catalyst is removed by washing with water or neutralization, and then the solvent is distilled off and the molten resin is recovered by extraction.

(Cresol novolac resin) Ortho-cresol novolak resin is a carboxylic acid such as acetic acid and propionic acid; alkyl alcohols such as methanol, ethanol, and butanol; ketones such as methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; ethyl acetate, acetic acid Esters such as butyl;
Easily soluble in ethers such as tetrahydrofuran and dioxane; and glycol ethers such as methoxyethanol and butoxycetanol.

Furthermore, the resin obtained is a linear polymer because it is easily soluble in these various solvents and no insoluble gel content is observed.

The number average molecular weight by vPo using methyl ethyl ketone as a solvent was 1,500 to 5,000, and when the ratio Q of the weight average molecular weight to number average molecular weight was measured using gel permeation chromatography using tetrahydrofuran as a solvent, it was found to be 1. It was .5-12.

In addition, this resin has a softening point measurement method of measuring the temperature at which the resin powder flows and becomes transparent under a microscope, and the temperature is 120℃ to 3QO℃.
It showed a softening point of .

On the other hand, cresol novolac resin obtained from a mixture of ortho-cresol and para-cresol is a random copolymer], is soluble in ethers such as tetrahydrofuran and dioxane, dimethylacetamide, and dimethylformamide, and has an insoluble gel component. Since you can't see it at all,
The resulting resin is a linear polymer.

The solubility in a solvent varies depending on the molar ratio of ortho-cresol and para-cresol and the molecular weight. The higher the molar ratio of para-cresol and the higher the molecular weight, the less soluble it becomes. For example, resins with a molar ratio of para-cresol and orthocresol of 515 and a softening point of 145°C or higher include ketones such as acetone and methyl ethyl ketone; glycol ethers such as methoxyethanol and ethoxyethanol; esters such as ethyl acetate; and epichlorohydrin. Although it is soluble in alcohols such as methanol and ethanol, it is poorly soluble in alcohols such as methanol and ethanol.

Polymerization of para-cresol in ethoxyethanol with para-formaldehyde and a sulfuric acid catalyst produces a linear high molecular weight para-cresol novolak resin with a softening point of over 300°C. However, this resin has poor solubility in solvents, and is hardly soluble in the above-mentioned solvents except tetrahydrofuran, dioxane, dimethylformamide, and dimethylacetamide.

〔Epoxy resin〕

There are two methods for producing polyglycidyl ether by reacting the high molecular weight linear cresol novolak resin with epihalohydrin.

(11 Ri L/Sole novolac resin and excess shrimp hydrin are reacted in the coexistence of an alkali metal hydroxide,
One-step method for producing polyglycidyl ether by simultaneously carrying out addition reaction of epihalohydrin to cresol novolac resin and ring-closing reaction to form an epoxy ring (2) Cresol novolak resin and excess epihalohydrin are combined into a phosphonium salt or quaternary ammonium salt. A two-step method for producing polyglycidyl ether t-11J by carrying out an addition reaction in the presence of a catalyst such as, and then carrying out a ring-closing reaction by adding an alkali metal hydroxide.

Of these two methods, the latter two-step method is preferable to the one-step method because the yield is higher and the content of high molecular weight substances in the resulting polyglycidyl ether is lower.

In the above-mentioned method, the reaction is carried out at a temperature ranging from 60 to 150°C, preferably from 80 to 120°C. The amount of shrimp halohydrin to be blended is 2 to 20 times the mole, preferably 8 to 12 moles, per equivalent of phenolic OH contained in the cresol novolac resin. The alkali metal hydroxide is at least equimolar to the phenol hydroxyl group of the cresol novolac resin, preferably 1.05 to 1.
．． Use 5 times the mole amount.

In addition, in the latter two-stage method, the addition reaction in the first stage is 40
It is carried out at ~150°C, preferably 70-140°C, and the subsequent ring-closing reaction is carried out at 20-150°C, preferably 40-80°C.
It will be held in The amount of catalyst is 0.1 to 5 mol relative to the resol novolak resin, and the amounts of shrimp halohydrin and alkali metal hydroxide are the same as in the one-stage method.

The subsequent ring-closing reaction in the one-stage method and the two-stage method can be carried out under normal pressure or reduced pressure (50 to 200 mHg) while continuously removing the produced sulfur water from the system by azeotroping with the shrimp halohydrin. good.

After the completion of these reactions, the reaction solution is filtered using a filter aid (for example, celite, etc.) to remove by-product salts, and unreacted shrimp halohydrin is recovered under reduced pressure to obtain a product or the reaction solution is filtered. After recovering unreacted shrimp halohydrin under reduced pressure, it is dissolved in a water-soluble organic solvent, such as methyl isobutyl ketone, cyclohexanone, etc., and this solution is brought into contact with water or hot water to remove inorganic impurities such as salt. Purification is carried out by dissolving in a phase and then distilling off the organic solvent.

Alternatively, dehydrochloric acid may be removed in a water-soluble solvent such as dioxane or tetrahydrofuran, followed by reprecipitation purification by adding the resin solution into 5 to 10 times the amount of water with stirring.

Examples of the raw shrimp halohydrin include epichlorohydrin, shrimp halohydrin, β-methylepichlorohydrin, and β-methyl shrimp bromohydrin.

In addition, potassium hydroxide,
Examples include sodium hydroxide.

Furthermore, examples of catalysts used in the first-stage addition reaction in the two-stage process include quaternary ammonium salts and phosphites. Examples of the quaternary ammonium salt include tetramethylammonium chloride, tetraethylammonium bromide, triethylmethylammonium chloride, tetraethylammonium iodide, and cetyltriethylammonium bromide. Examples of the phosphite include triphenylphosphonium halides (eg iodide, bromide, chloride), triphenylethylphosphonium diethyl phosphate and phosphite. A particularly preferred catalyst is tetramethylammonium chloride or tetraethylammonium bromide.

The high molecular weight cresol novolac epoxy resin produced in this manner has a number average molecular weight of 2,000 to 7,000 as measured by the steam process method (VPO) using dioxane or dimethylacetamide as a solvent.

In addition, the softening point measurement method uses a microscope to measure the temperature at which resin powder softens, flows, and becomes transparent.
It shows a softening point exceeding ℃.

This linear high molecular weight cresol novolak epoxy resin is soluble in organic solvents such as dioxane, dimethylacetamide, tetrahydrofuran, methyl ethyl ketone, chloroform, and cyclohexanone.

This cresol novolak epoxy resin, resin alone,
Alternatively, it can be used in combination with other epoxy compounds to serve as an epoxy resin. In other words, if this cresol novolac epoxy resin is used alone or in combination with one or more other epoxy compounds and is subjected to a curing (crosslinking) reaction with an appropriate curing agent, heat resistance and flexibility can be improved. sex,
It becomes a cured product with high impact resistance. There are no particular restrictions on the other epoxy compounds used in combination, and various epoxy compounds may be used in combination depending on the intended use. Other epoxy compounds used in combination include, for example, polyglycidyl ethers such as bisphenol A or bromobisphenol A; polyglycidyl esters such as phthalic acid and cyclohequinanedicarboxylic acid; or polyglycidyl amines with aniline or toluidine, etc. These are used in combination with the high molecular weight cresol novolak epoxy resin of the present invention in a proportion of 10 to 80% by weight in the epoxy compound.

(Curing Agent) As the curing agent for curing this cresol novolak epoxy resin, various curing agents similar to those used in known epoxy resins can be used. For example, aliphatic amines, aromatic amines, heterocyclic amines, Lewis acids such as boron trifluoride and their salts, organic acids, organic acid anhydrides, urea or their derivatives, and polymercaptan. Examples include the following. Specific examples include aromatic amines such as diaminodiphenylmethane, diaminodiphenylsulfone, and 2,4-diamino-m-xylene;
Imidazole or imidazole substitutes such as 2-methylimidazole, 2.4.5-triphenylimidazole, 1-cyanethyl-2-methylimidazole, or salts of these with organic acids; fumaric acid, trimellitic acid, hexahydrophthal Organic carboxylic acids such as acids; organic acid anhydrides such as phthalic anhydride, endomethylenetetrahydrophthalic anhydride, and hexahydrophthalic anhydride; urea derivatives such as dicyandiamide, melamine, and guanamine; triethylenetetramine, diethylenetriamine, xylylenediamine , aliphatic polyamines such as isophorone diamine, and adducts thereof with epoxy compounds such as ethylene oxide and propylene oxide, or acrylic compounds such as acrylonitrile and acrylic acid, etc. can be used.

Furthermore, polyhydric phenols such as phenol novolak resin, cresol novolak resin, and tetrahydroxyphenylethane can be used as a curing agent, and if necessary, amines can be used as an accelerator.

Furthermore, in addition to the curing agent, this high molecular weight cresol novolak epoxy resin may optionally contain plasticizers, organic solvents, reactive diluents, extenders, fillers, reinforcing agents, pigments, flame retardants, etc. Various additives such as thickeners and flexibility-imparting agents can be blended.

The cresol novolak epoxy resin of the present invention is a linear polymer that was previously considered impossible, and has a higher molecular weight and a higher softening point than the cresol novolac epoxy resins known so far. Therefore, the cured product of the linear high molecular weight cresol novolac epoxy resin of the present invention has superior heat resistance and strength compared to conventional products. Therefore, this cresol novolak epoxy resin can be used for laminated materials,
It can be used in the fields of molding materials, adhesives, and paints.

That is, a glass cloth is impregnated with a curable resin composition containing this epoxy resin and a curing agent dissolved in a solvent such as tetrahydrofuran or methyl ethyl ketone, dried to form a Gripreg, and then roughly layered with copper foil and several sheets of prepreg. By hot pressing, a copper-clad laminate for printed wiring boards can be manufactured.

Furthermore, a curing accelerator, a filler such as silica, and a lubricant are added to this composition, and the mixture is kneaded on heated rolls to produce a molding comparand. This compound is further molded using a transfer molding machine or the like and used for semiconductor encapsulation and mechanical parts.

Furthermore, an adhesive can be manufactured by blending a resin such as nylon, polyester, polyvinyl butyral, or carboxyl group-containing butadiene nitrile rubber with this curable resin composition, and adding a filler if necessary.

Furthermore, a filler is added to the polymeric ortho-cresol novolac epoxy resin, a curing agent, and a curing accelerator, and the mixture is kneaded with heated rolls, cooled, pulverized with a pulverizer, and classified with a sieve to prepare a powder coating. I can do it.

Next, the present invention will be explained in more detail using examples.

[Production example of novolak resin]

Example 1 o-, l'L'''/-1082, paraformaldehyde 322, and ethyl cellosolve 240? were placed in a reactor together with 10f of sulfuric acid and heated to 115°C with stirring.
The reaction was carried out for 4 hours.

After the reaction was completed, 172 NaHCO3 and 30 f of water were added to neutralize, and the reaction solution was poured into 2 cups of water while stirring at high speed, and the precipitated resin was separated and dried to form resin 1152.
I got it.

This resin was soluble in methanol, ethanol, phthanol, octatool, methyl cellosolve, ethyl cellosolve, tetrahydrofuran, dioxane, acetone, methyl ethyl ketone, ethyl acetate, and epichlorohydrin, and no gel content was observed.

When the molecular weight of this resin was measured by a steam method (40°C in methyl ethyl ketone), the number average molecular weight was 2,600. Further, the softening point of the resin determined by microscopy was 155°C. Furthermore, the Q value of the tetrahydrofuran solution was 3.0 as determined by gel permutation chromatography analysis.

Example 2 p-cresol 54P, o-cresol 542, paraformaldehyde 32t1 and ethyl cellosolve 2409
was put into a reactor with sulfuric acid 105', and 11
The reaction was carried out at 5°C for 4 hours. Reaction completed f & 17t NaH
After neutralizing by adding COa and 30 f of water, the reaction solution was poured into 2 cups of water while stirring at high speed, and the precipitated resin was separated from each other and dried to obtain a 115 F novolak resin.

The Mn of this resin obtained by the steam method (methyl ethyl ketone, 40°C) is 2800. The Q value according to gel permeation chromatography analysis of tetrahydrofuran solution is 2.
4. The softening point determined by microscopy was 200°C or higher.

Further, this resin was soluble in acetone, methyl ethyl ketone, methoxyethanol, ethoxyethanol, tetrahydrofuran, dioxane, dimethylformamide, dimethylacetamide, ethyl acetate, and epichlorohydrin.

Example 3 o-cresol 1089. Paraformaldehyde 29
．． 31FXIt-butano-#240 ft-p-toluenesulfonic acid 1 was placed in a reactor with 15F while stirring.
The reaction was carried out at a temperature of 10°C to 115°C for 4 hours. The reaction was carried out while removing the water produced at this time from the system using a separator.

Reaction completed After neutralization and washing with 3001F water containing FiNaHCO317f, the butanol phase was separated, heated to distill off the butanol, and the resin was extracted at 190°C and cooled to 1152
of resin was obtained.

Number average molecular weight Fi of Kome O-cresol novolak resin
1. 'loo, the softening point was 130°C.

Example 1 High molecular weight 0-cresol novolak resin obtained in Production Example 1 602, epichlorohydrin 462.5? and 4.02 ml of tetramethylammonium bromide were charged into a three-necked flask, and the reaction was carried out under reflux (117° C.) for 2 hours with stirring.

After that, the reaction solution was cooled to 60°C, a water separator was attached, 422% of sodium hydroxide was added, and under reduced pressure (150-100°C)
A ring-closing reaction was performed with [Hg ).

The produced water was continuously removed from the system by azeotroping with epichlorohydrin, and the reaction was terminated when the produced water reached 18 ml.

Unreacted epichlorohydrin 0.1-50 wHg
.

Collected at 60 to 110°C, added 120P'i of dioxane to dissolve the product, and after the by-produced sodium chloride was poured into 1 ton of water with stirring, re-sedimented and the resin was washed door to door. Dry.

The epoxy resin produced had a softening point of 126° C. as determined by 230X microscopy. Further, the number average molecular weight determined by the steam method was ≦950.

This resin is not soluble in tetrahydrofuran, dioxane, dimethylformamide, dimethylacetamide, methyl ethyl ketone, cyclohexanone, methoxyethyl acetate, chloroform, benzene, toluene, xylene, methanol, ethanol, butanol, methoxyethanol, ethoxyethanol, butoxy It was insoluble in ethanol.

The infrared absorption spectrum of this product is shown in FIG.

Example 2.3 Each of the high molecular weight cresol novolak resins obtained in Production Example 2.3 was mixed with 60? A high molecular weight cresol novolac epoxy resin was produced in the same manner as in Example 1 except that the resin was used.

The epoxy at of this epoxy resin is 235.225, and the softening point by microscopy is 200°C or higher, 105
It was ℃. In addition, the number average molecular weight by the steam method is 4
It was 200,2850.

Comparative Example 1 0-cresol 108f, 37% formalin 73? and 0.11!7 of concentrated hydrochloric acid were placed in a reactor, and the mixture was reacted at 85° C. for 1 hour and then for a further 4 hours under reflux.

After the reaction, 100 f of water was added to precipitate the resin, and the water was removed by decantation, followed by dehydration under a reduced pressure of 100x Hg, and the molten resin was taken out at 150°C, heated to solidify, and then crushed.

The number average molecular weight of this resin determined by the steam method was 580, and the softening point determined by microscopy was 73°C.

Ortho-cresol novolac resin 60 thus obtained
r, 462.59% of epichlorohydrin and 4.02% of tetramethylammonium bromide were charged into a reaction vessel, an addition reaction was carried out in the same manner as in Example 1, and further dehydrochloric acid epoxidation was performed with 422% of sodium hydroxide, and the same as in Example 1 was carried out. A resin was obtained by post-treatment. The epoxy weight of the produced resin was 220, and the softening point as determined by microscopy was 49°C (the softening point as determined by the durance method was 70°C).

Application example 1.2 25 parts of diaminodiphenylsulfone was blended with 100 parts by weight of the high molecular weight cresol novolac epoxy resin obtained in Examples 1 and 3, and after melt-mixing at 180°C, the mixture was thoroughly degassed and placed in the mold. It was poured into a mold and pre-cured at 180°C for 1 hour.
Post-curing was carried out at 40° C. for 4 hours to obtain a cured product having the physical properties shown in Table 1.

Comparative Application Example 1 A cured product was produced in the same manner as Application Example 1, except that the cresol novolak epoxy resin obtained in Comparative Example 1 was used instead of the epoxy resin. Table 1 shows the physical properties of this cured product.

Application Example 3 To 100 parts by weight of the high molecular weight cresol novolac epoxy resin obtained in Example 2, 48 parts of a phenol novolac resin with a number average molecular weight of 400, 20,000 parts of silica, and 1 part of BF3.2 methylimidazolyl salt were added. Add part to 1
Mixed wire for 10 minutes with a heated roll at 50℃, cooled, and crushed at 25℃.
Compression molding was carried out at a pressure of 80 Kq/ca in a mold at 0°C, the mold was removed after 20 minutes, and further post-curing was performed at 240°C for 4 hours.

Table 2 shows the physical properties of the cured product.

Comparative Application Example 2 A cured product was produced in the same manner as Application Example 3, except that the cresol novolak epoxy resin obtained in Comparative Example 1 was used as the epoxy resin. The physical properties are shown in Table-2.

Table-1 Table-2

[Brief explanation of drawings]

PI3 diagram is an infrared absorption spectrum diagram of the cresol novolac epoxy resin obtained in Example 1.

Claims (1)

[Claims] 1), the epoxy equivalent is 176 to 280, N, N-
The number average molecular weight measured by vapor pressure method in dimethylacetamide solvent is 2,000 to 7,000, and the softening point is 10.
Linear high molecular weight cresol novolac epoxy resin with a temperature of 0 to 300°C. 2) A linear high molecular weight cresol novolac resin with a softening point of 120° C. or higher and a number average molecular weight of 1500 or higher as measured by vapor pressure method in an N,N-dimethylacetamide solvent and epihalohydrin in the presence of an alkali metal hydroxide. The epoxy equivalent is 176 to 280, and N
, a method for producing a linear high molecular weight cresol novolac epoxy resin having a number average molecular weight of 2,000 or more as measured by vapor pressure method in an N-dimethylacetamide solvent. 3) The linear cresol novolac resin is an aliphatic compound having 3 to 12 carbon atoms, which is a mixture of ortho-cresol or a mixed cresol obtained by mixing ortho-cresol and para-cresol in a molar ratio of 10:0 to 1:9, and an aldehyde. It must be obtained by polycondensation in the presence of an acidic catalyst in a solvent selected from alcohol, glycol ether having 3 to 6 carbon atoms, benzyl alcohol, and aliphatic carboxylic acid having 2 to 6 carbon atoms. The manufacturing method according to claim 2, characterized in that: