JPH08120057A - Epoxy resin composition - Google Patents

Abstract

PURPOSE: To obtain an epoxy resin compsn. which is easy to handle and gives a cured item excellent in heat resistance and high-temp. strengths by compounding an epoxy resin and a curative therefor each having a biphenyl backbone. CONSTITUTION: This resin compsn. contains, as the essential components, an epoxy resin having a biphenyl backbone represented by the formula [wherein each R is independently H, a halogen, an alkyl, an alkoxy, optionally a substd. phenyl, optionally a substd. aralkyl, or a divalent or higher hydrocarbon group having the other end or ends connected to other backbone or backbones] and a curative therefor having a biphenyl backbone represented by formula I. The content of the biphenyl backbone of the compsn. is 28-48wt.% provided the mol.wt. of the backbone is 144.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an epoxy resin composition which gives a cured product which is easy to handle and has high heat resistance, that is, a cured product which is excellent in strength at high temperatures.

[0002]

2. Description of the Related Art In recent years, as the applications of polymer materials have expanded and the usage conditions have become more severe, various characteristics required for polymer materials have become more severe. In some applications, polymeric materials are exposed to high temperatures,
Since it softens and its strength is insufficient, or it decomposes and deteriorates, problems such as long-term unusability occur.

Epoxy resin compositions are used in various fields such as lamination, coating, adhesion, sealing and molding, but for the reasons described above, the bisphenol A type epoxy resin which is generally used at present is used. However, the epoxy resin composition that has been used cannot satisfy the required characteristics sufficiently.

In order to improve heat resistance, it has been attempted to use a polyfunctional epoxy resin such as a novolac type epoxy resin, a trifunctional type epoxy resin or a tetrafunctional type epoxy resin, but curing of these epoxy resins is attempted. However, these epoxy resins have the drawbacks in handling that they are not sufficiently strong at high temperatures, and those epoxy resins have a high softening point and a high viscosity and their compatibility with a curing agent is not good.

[0005]

SUMMARY OF THE INVENTION The present invention is intended to provide an epoxy resin composition which is easy to handle and has a high heat resistance, that is, a cured product which is excellent in strength at high temperature.

[0006]

Means for Solving the Problems As a result of various studies to solve the above problems, the present inventors have used an epoxy resin containing a biphenyl skeleton as an epoxy resin and a biphenyl as an epoxy resin curing agent. The purpose could be achieved by using an epoxy resin curing agent containing a skeleton.

That is, the epoxy resin composition of the present invention comprises (a) the general formula (I)

[0008]

Embedded image (In the formula, each R is a hydrogen atom, a halogen atom, an alkyl group,
It is an alkoxy group, a substituted or unsubstituted phenyl group, a substituted or unsubstituted aralkyl group, or a divalent or higher hydrocarbon group having the other end linked to another skeleton, and each R is the same or different. May be. ) An epoxy resin containing a biphenyl skeleton represented by

(B) General formula (I)

[0010]

[Chemical 4] (In the formula, each R is a hydrogen atom, a halogen atom, an alkyl group,
It is an alkoxy group, a substituted or unsubstituted phenyl group, a substituted or unsubstituted aralkyl group, or a divalent or higher hydrocarbon group having the other end linked to another skeleton, and each R is the same or different. May be. The epoxy resin curing agent containing a biphenyl skeleton represented by) is contained as an essential component, and the content of the biphenyl skeleton with respect to the total amount of all epoxy resins and all the epoxy resin curing agents is such that the molecular weight of the biphenyl skeleton is 144. The composition has a calculated value of 28 to 48% by weight.

The biphenyl skeleton represented by the above general formula (I) used in the epoxy resin composition of the present invention (hereinafter sometimes referred to as "the same biphenyl skeleton" or simply "biphenyl skeleton") is contained. As the epoxy resin to be, various epoxy resins obtained by subjecting various phenols containing the same biphenyl skeleton, various amines or various carboxylic acids and epihalohydrin to condensation reaction in the presence of alkali, can give.

Examples of phenols containing the same biphenyl skeleton as raw materials for producing the epoxy resin include 4,4'-biphenol and 3,3'-dimethyl-4,
4'-biphenol, 3,5-dimethyl-4,4'-biphenol, 3,3'-dibutyl-4,4'-biphenol, 3,5-dibutyl-4,4'-biphenol,
3,3'-diphenyl-4,4'-biphenol, 3,
3'-dibromo-4,4'-biphenol, 3,3 ',
5,5'-tetramethyl-4,4'-biphenol,
3,3'-Dimethyl-5,5'-dibutyl-4,4'-
Biphenol, 3,3 ', 5,5'-tetrabutyl-
4,4′-dihydroxybiphenyls such as 4,4′-biphenol, 3,3 ′, 5,5′-tetrabromo-4,4′-biphenol; these various 4,4′-dihydroxybiphenyls and formaldehyde , Acetaldehyde, propylaldehyde, butyraldehyde, benzaldehyde, hydroxybenzaldehyde, crotonaldehyde, glyoxal and other polyhydric phenol resins obtained by condensation reaction with various aldehydes; phenol, cresol, xylenol, propylphenol, bromophenol, bisphenol A, bisphenol F, bisphenol AD, hydroquinone, methylhydroquinone, dimethylhydroquinone, dibutylhydroquinone, resorcin, methylresorcin, biphenol, dihydroxynaphtha Emissions, dihydroxydiphenyl ether, phenol novolak resin, cresol novolak resin, bisphenol A novolak resin, dicyclopentadiene phenol resin, terpene phenol resin, phenol aralkyl resin, various phenols and biphenyls such as naphthol novolak resin -4,
4'-dialdehyde, 4-hydroxybiphenyl-4 '
-Polyhydric phenol resins obtained by condensation reaction with aldehydes containing various biphenyl skeletons such as aldehydes; the above-mentioned various phenols and 4,4'-dihydroxymethylbiphenyl, 4,4'-diisopropenyl Examples thereof include polyhydric phenol resins obtained by condensation reaction with biphenyl and the like.

As the amines containing the same biphenyl skeleton as the raw material for producing the epoxy resin, for example, 4,4'-diaminobiphenyl, 3,3'-dimethyl-4,4'-diaminobiphenyl, 3, 5-dimethyl-4,4'-diaminobiphenyl, 3,3 ', 5,5'
-4,4'-diaminobiphenyls such as tetramethyl-4,4'-diaminobiphenyl; various types of these 4,
4'-diaminobiphenyls, formaldehyde, acetaldehyde, propyl aldehyde, butyraldehyde, benzaldehyde, hydroxybenzaldehyde,
Polyvalent amino resins obtained by condensation reaction with various aldehydes such as crotonaldehyde and glyoxal; various amines such as aniline, methylaniline and diaminodiphenylmethane, and biphenyl-4,4′-dialdehyde and 4-amino Polyfunctional amino resins obtained by condensation reaction with aldehydes containing various biphenyl skeletons such as biphenyl-4′-aldehyde; various amines and 4,
Examples thereof include polyvalent amino resins obtained by condensation reaction with 4′-dihydroxymethylbiphenyl, 4,4′-diisopropenylbiphenyl and the like.

Further, as the carboxylic acids having the same biphenyl skeleton as a raw material for producing the epoxy resin, for example, biphenyl-4,4'-dicarboxylic acid,
3,3'-dimethylbiphenyl-4,4'-dicarboxylic acid, 3,5-dimethylbiphenyl-4,4'-dicarboxylic acid, 3,3 ', 5,5'-tetramethylbiphenyl-
Biphenyl-4,4'-, such as 4,4'-dicarboxylic acid
Polyphenolic resin obtained by condensation reaction of dicarboxylic acids, various phenols or various amines with various aldehydes containing a biphenyl skeleton such as biphenyl-4-aldehyde-4′-carboxylic acid and a carboxyl group Alternatively, a polyvalent amino resin may be used.

The biphenyl skeleton used in the present invention can be obtained by reacting one or a mixture of two or more phenols, amines or carboxylic acids containing these various biphenyl skeletons with epihalohydrin by a conventional method. An epoxy resin containing is obtained.

Among these various epoxy resins having a biphenyl skeleton, epoxy resins obtained from various phenols having a biphenyl skeleton are preferable from the viewpoint of cured properties. More preferable is an epoxy resin produced from at least one phenol compound selected from biphenol and tetramethylbiphenol and epihalohydrin.

An epoxy resin derived from 3,3 ', 5,5'-tetramethyl-4,4'-biphenol is, for example, Epicoat YX4000 (trade name of Yuka Shell Epoxy Co., Ltd.) A mixed epoxy resin of an epoxy resin derived from ', 5,5'-tetramethyl-4,4'-biphenol and an epoxy resin derived from 4,4'-biphenol is, for example, Epicoat YL6121H (Oilized shell Since it is commercially available as Epoxy Co., Ltd., the present invention can be carried out using these commercially available products.

Further, in the epoxy resin composition of the present invention, in order to adjust the content of the above-mentioned biphenyl skeleton within the above-mentioned predetermined range, or to adjust the handleability and cured physical properties of the resin composition, etc. In addition, the specific epoxy resin containing the above-mentioned biphenyl skeleton can be mixed with other epoxy resins and used.

Other epoxy resins which can be used as a mixture include, for example, bisphenol A, bisphenol F, bisphenol AD, hydroquinone,
Methylhydroquinone, dibutylhydroquinone, resorcin, methylresorcin, dihydroxydiphenylether, dihydroxynaphthalene, phenol novolac resin, cresol novolac resin, bisphenol A
Various phenols such as novolac resin, dicyclopentadiene phenol resin, terpene phenol resin, phenol aralkyl resin, naphthol novolac resin, brominated bisphenol A, brominated phenol novolac resin, and these various phenols, hydroxybenzaldehyde, Crotonaldehyde, various phenolic compounds such as polyhydric phenol resins obtained by condensation reaction with various aldehydes such as glyoxal,
Epoxy resin produced from epihalohydrin; various amine compounds such as diaminodiphenylmethane, aminophenol, xylenediamine, and epoxy resin produced from epihalohydrin; various carboxylic acids such as methylhexahydrophthalic acid and dimer acid, An epoxy resin produced from epihalohydrin and the like can be mentioned.

The proportion of these other epoxy resins used is
The content of the same biphenyl skeleton with respect to the total amount of all epoxy resins and all epoxy resin curing agents is in the above range (28 to
48% by weight).

Next, as the epoxy resin curing agent containing the biphenyl skeleton represented by the general formula (I) used in the epoxy resin composition of the present invention, various phenols containing the same biphenyl skeleton, Examples include various amines containing a biphenyl skeleton, various carboxylic acids containing the same biphenyl skeleton, and various active esters containing the same biphenyl skeleton.

Examples of the phenols having the same biphenyl skeleton as the epoxy resin curing agent include the same phenols as those mentioned above as a raw material for producing the epoxy resin having the same biphenyl skeleton.

As the amines having the same biphenyl skeleton as the epoxy resin curing agent, there may be mentioned the same amines as those mentioned above as a raw material for producing the epoxy resin having the same biphenyl skeleton.

Examples of the carboxylic acids containing the same biphenyl skeleton as the epoxy resin curing agent include the same carboxylic acids as described above as the raw material for producing the epoxy resin containing the same biphenyl skeleton.

Further, as the active ester containing the same biphenyl skeleton as the epoxy resin curing agent,
Various phenols similar to those described above as a raw material for producing the epoxy resin containing the same biphenyl skeleton,
Ester compounds esterified with various carboxylic acids such as acetic acid, propionic acid, benzoic acid, acrylic acid or naphthoic acid; carboxylic acids similar to those described above as a raw material for producing the epoxy resin containing the same biphenyl skeleton. And ester compounds esterified with methanol, ethanol, phenol, naphthol and the like.

Among these various epoxy resin hardeners containing a biphenyl skeleton, phenols containing a biphenyl skeleton or active esters containing a biphenyl skeleton are preferable from the viewpoint of cured physical properties.

Further, in the epoxy resin composition of the present invention, in order to adjust the content of the same biphenyl skeleton within the above-mentioned predetermined range, or to adjust the handleability and cured physical properties of the resin composition, etc. The other epoxy resin curing agent other than the specific epoxy resin curing agent containing the same biphenyl skeleton can be used together (mixed and used).

Other epoxy resin curing agents that can be used in combination are bisphenol A, bisphenol F, bisphenol AD, hydroquinone, resorcin, methylresorcin, dihydroxynaphthalene, dihydroxydiphenyl ether, phenol novolac resin, cresol novolac resin. , Various phenols such as bisphenol A novolac resin, dicyclopentadiene phenol resin, terpene phenol resin, phenol aralkyl resin, naphthol novolac resin, brominated bisphenol A, brominated phenol novolac resin; these various phenols and hydroxy Polyphenolic resin obtained by condensation reaction with various aldehydes such as benzaldehyde, crotonaldehyde, glyoxal Various phenol resins; active ester compounds obtained by esterifying all or part of the phenolic hydroxyl groups of these various phenols (resins) with benzoate or acetate; methyltetrahydrophthalic anhydride, hexahydro Acid anhydrides such as phthalic anhydride, pyromellitic dianhydride, methyl nadic acid and the like; amines such as diethylenetriamine, isophoronediamine, diaminodiphenylmethane, diaminodiphenylsulfone and dicyandiamide.

The proportion of these other epoxy resin curing agents used is such that the content of the same biphenyl skeleton with respect to the total amount of all epoxy resins and all epoxy resin curing agents is in the above range (28 to 48% by weight). is there.

The amount of the epoxy resin curing agent used in the epoxy resin composition of the present invention is such that the total amount of groups that react with the epoxy groups in all the epoxy resin curing agent components is 1 mol of the epoxy groups in all the epoxy resin components. The amount is preferably 0.5 to 2.0 mol, more preferably 0.7 to 1.2.
It is the amount that becomes a mole.

The content of the same biphenyl skeleton with respect to the total amount of all epoxy resins and all epoxy resin curing agents in the present invention is 28 to 48% by weight, preferably 30 to 45% by a value calculated with the molecular weight of the same biphenyl skeleton being 144. The content of the biphenyl skeleton of the epoxy resin containing the biphenyl skeleton to be used or the curing agent of the epoxy resin containing the biphenyl skeleton is too low, or the mixture may be used by mixing. If the content of the biphenyl skeleton is less than the above range due to too much ratio of the epoxy resin or other epoxy resin curing agent, the strength of the cured product at high temperature will decrease, and it will be used again. High content of biphenyl skeleton in epoxy resin containing biphenyl skeleton and epoxy resin curing agent containing biphenyl skeleton If the content of the biphenyl skeleton is more than the above range due to an excessively small proportion of other epoxy resin or other epoxy resin curing agent used by mixing or mixing, the softening point of the epoxy resin composition This is because the viscosity of the composition increases and the compatibility between the epoxy resin and the curing agent deteriorates, so that the handling of the composition deteriorates and the cured physical properties become nonuniform.

Various additives can be added to the epoxy resin composition of the present invention in the same manner as other general epoxy resin compositions. Examples of these various additives include a curing accelerator, a filler, a coupling agent, a flame retardant, a plasticizer, a solvent, a reactive diluent, a pigment, and the like, and these may be appropriately blended as necessary. it can.

Examples of the curing accelerator include imidazoles such as 2-methylimidazole and 2-ethyl-4-methylimidazole; 2,4,6-tris (dimethylaminomethyl) phenol, benzyldimethylamine, 1,5. -Diazabicyclo (5,4,0) -7-undecene (DBU), 3- (3,4-dichlorophenyl)
Amines such as -1,1-dimethylurea (DCMU); tributylphosphine, triphenylphosphine,
Examples thereof include organic phosphorus compounds such as tris (dimethoxyphenyl) phosphine, and various salts thereof.

Examples of the filler include fused silica, crystalline silica, glass powder, alumina, calcium carbonate and the like. Further, examples of the flame retardant include antimony trioxide, phosphoric acid, and the like, and the flame retardancy can be achieved by using a part of the epoxy resin used as a brominated epoxy resin.

Since the epoxy resin composition of the present invention gives a cured product which is easy to handle and has high heat resistance, that is, a cured product having excellent strength at high temperature, it can be used for adhesion, casting, sealing,
It can be advantageously used for applications such as molding, lamination and painting.

[0036]

[Examples] Further detailed description will be given below with reference to production examples of epoxy resin curing agents, examples and comparative examples.

Epoxy resin curing agent production example 1 Internal volume 1000 ml equipped with thermometer, stirrer and cooling tube
In a three-necked flask containing 93 g of 4,4′-biphenol,
Phenol 188g, methoxypropanol 400g,
Then, 3 g of oxalic acid was charged, and the temperature was raised to 100 ° C. to uniformly dissolve the oxalic acid. Then, 36% formaldehyde aqueous solution 1
20 g was added dropwise over 1 hour while maintaining the internal temperature of the above solution at 100 ° C. Then, the mixture was kept at 100 ° C. for 3 hours for reaction.

Subsequently, water and methoxypropanol are distilled off while gradually raising the temperature of the reaction product, and finally 180
C., kept under reduced pressure of 3 mmHg for 3 hours to completely remove water, methoxypropanol and unreacted phenol,
An epoxy resin curing agent containing a biphenyl skeleton was obtained.

This epoxy resin curing agent has a phenolic hydroxyl group equivalent of 100 g / eq. It was a yellow-red solid having a softening point of 94 ° C. and a biphenyl skeleton content of 29% by weight.

Epoxy resin curing agent production example 2 Internal volume 2000 ml equipped with thermometer, stirrer and cooling tube
In a three-necked flask containing 93 g of 4,4′-biphenol,
And pyridine (300 g) were charged, and the temperature was raised to 50 ° C. to uniformly dissolve them. Then add 105 g of acetic anhydride to the solution.
Was added dropwise over 1 hour while maintaining the internal temperature of the solution at 60 ° C., and then the solution was kept at 60 ° C. for 3 hours to cause a reaction.

Subsequently, after adding 500 g of methyl isobutyl ketone to the reaction product to dissolve it, the product was washed with water to remove the by-product salt, and further methyl isobutyl ketone was removed under reduced pressure to obtain an epoxy resin curing agent.

This epoxy resin curing agent has an active ester group equivalent of 110 g / eq. It was a yellow solid having a softening point of 61 ° C. and a biphenyl skeleton content of 65% by weight.

Examples 1 to 4 and Comparative Examples 1 to 4 As shown in Table 1, a commercially available epoxy resin was used as the epoxy resin, and the epoxy resin obtained in the above production example was used as the epoxy resin curing agent. Commercially available curing agents were used, and triphenylphosphine was also used as a curing accelerator, and these were compounded in a combination as shown in Table 1 to prepare various epoxy resin compositions.

For the actual compounding and curing, first, the epoxy resin and the curing agent are melt-mixed at a temperature of 100 to 120 ° C. for 5 minutes, then the curing accelerator is rapidly mixed and poured into a mold, and the mixture is heated to 180 ° C. Heated for 8 hours to cure. However, in the case of Comparative Example 4, the compatibility between the resin and the curing agent was poor and the casting operation could not be performed.

The content of biphenyl skeleton of each of the obtained resin compositions is as shown in Table 1, and the bending strength and bending elasticity at 230 ° C. of each test piece obtained by cutting the above-mentioned cast cured product. The results of the rate tests are shown in Table 1, respectively.

[0046]

[Table 1]

Note to Table 1 Commercial product A: 3,3 ', 5,5'-tetramethyl-4,
Epoxy resin derived from 4'-biphenol (Okaka Shell Epoxy Co., Ltd. trade name Epikote YX400
0, epoxy equivalent 186, biphenyl skeleton content 41% by weight) commercial product B: an epoxy resin derived from 4,4′-biphenol, 3,3 ′, 5,5′-tetramethyl-4,
Mixture with an epoxy resin derived from 4'-biphenol (Yuka Kachel Epoxy Co., Ltd. trade name Epicoat YL6121H, epoxy equivalent 172, biphenyl skeleton content 45% by weight) Commercial product C: Orthocresol novolac type epoxy resin (oil Ciel Epoxy Co., Ltd. Product name Epicoat 18
0S65, epoxy equivalent 210) Commercial product D: 4,4′-biphenol (biphenol skeleton content 77% by weight) Commercial product E: phenol novolac resin (manufactured by Gunei Chemical Co., Ltd., hydroxyl equivalent 103, softening point 85 ° C.) * 1: The resin composition had poor compatibility and could not be cast,
Since a test piece could not be created, it could not be measured.

As is clear from Table 1, the epoxy resin compositions of the respective examples have a significantly higher flexural strength and flexural modulus at high temperature (230 ° C.) than those of the epoxy resin compositions of Comparative Examples 1 to 3 for curing. It is suitable for the production of molded products used at high temperatures, since it can be used to provide molded products.

[0049]

The epoxy resin composition of the present invention gives a cured product having a low melt viscosity, good compatibility, excellent handleability and high heat resistance, that is, high strength at high temperatures. Therefore, it can be advantageously used in the fields of adhesion, casting, sealing, molding, lamination and the like.

Claims (3)

[Claims] 1. (a) General formula (I): (In the formula, each R is a hydrogen atom, a halogen atom, an alkyl group,
It is an alkoxy group, a substituted or unsubstituted phenyl group, a substituted or unsubstituted aralkyl group, or a divalent or higher hydrocarbon group having the other end linked to another skeleton, and each R is the same or different. May be. ) An epoxy resin containing a biphenyl skeleton represented by the formula (b), and (b) the general formula (I): (In the formula, each R is a hydrogen atom, a halogen atom, an alkyl group,
It is an alkoxy group, a substituted or unsubstituted phenyl group, a substituted or unsubstituted aralkyl group, or a divalent or higher hydrocarbon group having the other end linked to another skeleton, and each R is the same or different. May be. The epoxy resin curing agent containing a biphenyl skeleton represented by) is contained as an essential component, and the content of the biphenyl skeleton with respect to the total amount of all epoxy resins and all the epoxy resin curing agents is such that the molecular weight of the biphenyl skeleton is 144. An epoxy resin composition, which has a calculated value of 28 to 48% by weight. 2. The epoxy according to claim 1, wherein the epoxy resin containing a biphenyl skeleton is an epoxy resin obtained by reacting at least one phenol compound selected from biphenol and tetramethylbiphenol with epihalohydrin. Resin composition. 3. The epoxy resin composition according to claim 1, wherein the epoxy resin curing agent containing a biphenyl skeleton is at least one selected from a biphenyl skeleton-containing phenol compound and a biphenyl skeleton-containing active ester compound. Stuff.