JPS63152613A - Novel heat-resistant epoxy resin - Google Patents

Abstract

PURPOSE:To obtain the titled trifunctional resin, capable of providing cured articles having excellent heat resistance as well as low modulus of elasticity and useful as molding and powder coating materials without blocking, by using a specific trisphenolic compound and (beta-methyl)epihalohydrin. CONSTITUTION:A trifunctional epoxy resin obtained from (A) a trisphenolic compound expressed by the formula (R1 is H, methyl or tert-butyl; R2 is tert- butyl; R3 and R4 are H or 1-4C alkyl), preferably 1,1,3-tris(2-methyl-4-hydroxy-5- tert-butylphenyl)butane, etc., and (B) a (beta-methyl)epihalohydrin.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a new heat-resistant epoxy resin, and more specifically, it provides a cured product with excellent heat resistance and a low elastic modulus, and further has a softening point as an epoxy resin. This invention relates to a new heat-resistant epoxy resin that is useful for applications such as molding materials and powder coatings, and which does not block due to its high heat resistance.

(Prior art and its problems) Epoxy resins are used for molding materials, adhesives, powder coatings, composite materials, etc., but in order to improve their heat resistance, phenol novolac type epoxy resins, orthocresol Polyfunctional epoxy resins such as novolac type epoxy resins are used. Although cured products of these epoxy resins have excellent heat resistance, they have a high modulus of elasticity and are brittle, so they have the drawback of being susceptible to cracking due to heat shock and having low reliability.

U.S. Pat. No. 2,885,385 and U.S. Pat. No. 3,218,370 disclose 1,1,3-tris(p-glycidoxyphenyl)propane and 1.1
．． 3-tris(3,5-dimethyl-4-glycidoxyphenyl)propane is described. However, these compounds themselves have low softening points (the former is semi-solid at room temperature, and the latter has a softening point of about 60°C), so when using these compounds as molding materials or powder coatings, They have the disadvantage of causing blocking, and furthermore, cured products made from these compounds also have a disadvantage of low heat resistance.

(Objective of the invention) The present invention has a high softening point and does not cause blocking when prepared into molding materials or powder coatings, has excellent heat resistance, and has a low elastic modulus that causes cracks to occur due to heat shock. An object of the present invention is to provide a novel trifunctional epoxy resin from which a cured product with excellent heat shock resistance can be obtained.

(Structure of the Invention) The present invention provides the following general formula, where R1 is a hydrogen atom, a methyl group, or a tertiary butyl group, R2 is a tertiary butyl group, and R5 is a hydrogen atom or a carbon atom 1 R4 is a lower alkyl group containing 1 to 4 carbon atoms, and R4 is a hydrogen atom or a lower alkyl group containing 1 to 4 carbon atoms, and they may not all be the same.

This is a novel heat-resistant epoxy resin characterized in that it is a trifunctional epoxy resin obtained from a trisphenol compound represented by the following formula, shrimp herohydrin or β-methyl ester, and herrohydrin.

(Effect of the invention) The epoxy resin of the present invention has a cured product obtained from the epoxy resin that
It has excellent heat resistance equivalent to or better than the cured product made from orthocresol novolac type epoxy resin, which is conventionally known as an epoxy resin with excellent heat resistance, and also has excellent heat shock resistance due to its low elastic modulus. Remarkably excellent effects can be achieved.

Furthermore, the epoxy resin of the present invention has a softening point of about 100°C, which is much higher than that of the known trifunctional epoxy resin having a similar structure, and therefore, it can be used as a molding material. It is possible to achieve an extremely excellent effect of not exhibiting a blocking phenomenon when preparing a powder coating.

The reason why the epoxy resin of the present invention exhibits such excellent effects is presumed to be due to the bulky tertiary butyl group introduced into its benzene skeleton.

(Preferred Embodiment of the Invention) The heat-resistant epoxy resin of the present invention has the following general formula, where R1 is a hydrogen atom, a methyl group or a tertiary butyl group, R2 is a tertiary butyl group, and R3 is , a hydrogen atom or a lower alkyl group containing 1 to 4 carbon atoms, and R3 is a hydrogen atom or a lower alkyl group containing 1 to 4 carbon atoms, and they may not all be the same.

It is a trifunctional epoxy resin obtained from a trisphenol compound represented by and shrimp halohydrin or β-methyl shrimp halohydrin.

Among the trifunctional epoxy resins of the present invention, a particularly preferable epoxy resin contains 1 as the above trisphenol compound.
,1. :3-tris(2-methyl-4-hydroxy-5
-tertiary butylphenyl)butane, 1,1,3-tris(
3-Methyl-4-hydroxy-5-tert-butylphenyl)butane, s, 1.3-tris(3,5-ditert-butyl-4-hydroxyphenyl)butane, 1.1.3-tris(3 -tertiary-butyl-4-hydroxyphenyl)butane, 1,1,3-tris(2,5-ditertiary-butyl-4-hydroxyphenyl)butane,! , 1.3-tris(2-
Tertiary butyl-4-hydroxy-5-methylphenyl)butane, 2,2゜4-tris(2-methyl-4-hydroxy-5-tertiary butylphenyl)butane, 2,2.4-tris(3- Methyl-4-hydroxy-5-tert-butylphenyl)butane, 2,2.4-tris(3゜5-ditert-butyl-4-hydroxyphenyl)butane, 2,2.4
-)-Lis(3-tert-butyl-4-hydroxyphenyl)butane, 2,2,4-tris(2,5-ditert-butyl-4-hydroxyphenyl)butane, 2,2,4-tris( 2-tertiary butyl-4-hydroxy-5-methylphenyl)butane, 1.1. ．． 3-tris(2-methyl-4
-hydrotertiary-5-tertiarybutylphenyl)propane, 1
, 1,3-tris(3-methyl-4-hydroxy-5-
tert-butylphenyl)propane, 1.1.3-t-lis(3,5-ditert-butyl-4-hydroxyphenyl)propane, 1,1.3-tris(3-tert-butyl-4-hydroxy phenyl)propane, 1,1,3-tris(2
, 5-ditert-butyl-4-hydroxyphenyl)propane, 1,1.3-tris(2-tert-butyl-4-hydroxy-5-methylphenyl)propane, etc. be. The above trisphenol compound can be obtained by adding an appropriate dialkyl-substituted phenol to an aliphatic unsaturated aldehyde or an aliphatic saturated ketone such as acrolein, methacrolein, crotonaldehyde, or methyl vinyl ketone.

Further, as the shrimp halohydrin or β-methyle and halohydrin to be reacted with the above trisphenol compound, it is preferable to use epichlorohydrin or β-methylepichlorohydrin because it can be easily produced on a large scale industrially.

Specific examples of the trifunctional epoxy resin of the present invention include 1,
1.3-)-Lis(2-methyl-4-glycidoxy-5
-tertiary butylphenyl)butane, 1,s,3-tris(
3-Methyl-4-glycidoxy-5-tertiary butylphenyl)butane, 1゜1゜3-tris(3,5-ditertiarybutyl-4-glycidoxyphenyl)butane, 1,1.3-
Tris (3-tertiary butyl-4-glycidoxyphenyl)
Butane, 1,1,3-tris(2,5-ditert-butyl-
4-glycidoxyphenyl)butane, 1.1.3-tris(2-tert-butyl-4-glycidoxy-5-methylphenyl)butane, 2°2.4-1lis(2-methyl-4
-glycidoxy-5-tertiary butylphenyl)butane, 2
．． 2゜4-tris(3-methyl-4-glycidoxy-5
-tertiary butylphenyl)butane, 2,2,4-tris(
3,5-ditert-butyl-4-glycidoxyphenyl)butane, 2,2,4-tris(3-tert-butyl-4-glycidoxyphenyl)butane, 2.2.4-)-lis (2
, 5-ditert-butyl-4-glycidoxyphenyl)butane, 2,2,4-tris(2-tert-butyl-4-glycidoxy-5-methylphenyl)butane, 1,1,3-tris( 2-Methyl-4-glycidoxy-5-tert-butylphenyl)propane, 1,1.3-)-lis(3-methyl-4-glycidoxy-5-tert-butylphenyl)propane, 1,1.3- Tris(3,5-ditert-butyl-4
-glycidoxyphenyl)propane, 1,1.3-tris(3-tert-butyl-4-glycidoxyphenyl)propane, 1,1°3-tris(2,5-di-tert-butyl-4
-glycidoxyphenyl)propane, 1,1.3-)-
Examples include lis(2-tertiary butyl-4-hydroxy-5-methylphenyl)propane.

The epoxy resin of the present invention is produced by etherifying the trisphenol compound and shrimp halohydrin or β-methyl shrimp halohydrin in the presence of a suitable etherification catalyst, and then dehydrohalogenating the compound. The above-mentioned etherification step and dehydrohalogenation step may be performed separately, or may be performed substantially simultaneously within the same system.

Trisphenol compounds and shrimp halohydrin or β-
The usage ratio of methyl shrimp halohydrin is 1 mole of trisphenol compound, shrimp halohydrin or β
-Methylevihalohydrin is preferably 3 to 30 moles.

The etherification catalyst used in the above etherification step includes tertiary amines such as trimethylamine and triethylamine, tertiary phosphines such as triphenylphosphine and tributylphosphine, tetramethylammonium chloride, tetramethylammonium bromide, and tetratylylammonium chloride. , tetraethylammonium bromide, quaternary ammonium salts such as choline chloride, quaternary phosphonium salts such as tetramethylphosphonium bromide, tetramethylphosphonium iodide, triphenylpropylphosphonium bromide, and tertiary salts such as benzyldibutylsulfonium chloride and benzyldimethylsulfonium chloride. Examples include sulfonium salts, alkali metal hydroxides such as sodium hydroxide, potassium hydroxide, and lithium hydroxide.

In particular, quaternary ammonium salts are preferred as catalysts for carrying out only the etherification step. In order to carry out the etherification step and the dehydrohalogenation step at the same time, it is preferable to use an alkali metal hydroxide as a catalyst, particularly sodium hydroxide.

The amount of the etherification catalyst used for the etherification step is preferably 0.005 to 5 mol% based on 1 equivalent of the phenolic hydroxyl group of the trisphenol compound used. When the hydrogen step is carried out simultaneously, it is preferable to use the alkali metal hydroxide in an amount of 1 mole or more, preferably 1.02 to 1.05 times, per equivalent of the phenolic hydroxyl group of the trisphenol compound used. .

The etherification step is preferably carried out by reacting at a temperature of 60 to 110° C. under normal pressure for about 1 to 12 hours. Even when the etherification step and the dehydrohalogenation step are carried out simultaneously, they can be carried out under the above reaction conditions.

When the dehydrohalogenation step is performed subsequent to the etherification step, an alkali metal hydroxide as described above is added to the etherification reaction product mixture in an amount of 1 to 1 phenolic hydroxyl group of the trisphenol compound used. It is preferable to add at least twice the mole, preferably 1.02 to 105 times the mole, and carry out the dehydrohalogenation reaction at a temperature of 60 to 100° C. while removing by-product water from the reaction system under reduced pressure.

In addition, in order to suppress the formation of gel, the degree of the first dehydrohalogenation is set to 1 mole or less of the amount of alkali metal hydroxide used per 1 equivalent of phenolic hydroxyl group,
After the reaction, dehydrohalogenation can be further carried out using a necessary amount of alkali metal hydroxide.

The produced trifunctional epoxy resin can be purified by a known purification method for general polyfunctional epoxy resins. For example, unreacted shrimp halohydrin or β-methyl shrimp halohydrin is distilled off from the reaction product mixture, hydrocarbon and water are added to this, and the epoxy resin is added to the hydrocarbon phase and the sodium halide is added to the water phase in 8 rows. After that, the hydrocarbon phase is separated, and then an aqueous alkali hydroxide solution is added to the hydrocarbon phase, and after stirring, an aqueous sodium dihydrogen phosphate solution is added to neutralize it, the hydrocarbon phase is separated, and this is subjected to azeotropic distillation. The purified trifunctional epoxy resin can be obtained by removing the water by removing the water and then vacuum distilling the hydrocarbon phase to remove the hydrocarbons.

The trifunctional epoxy resin of the present invention usually has a softening point of 80 to 140°C by the ring and ball method, and an epoxy equivalent of 22
0 to 380.

The trifunctional epoxy resin of the present invention is a composition containing curing agents such as aliphatic amine type, aromatic amine type, amine adduct, dicyandiamide, and acid anhydride, which are known as curing agents for ordinary epoxy resins. It can be used in the production of molding materials, powder coatings, etc.

The amount of hardening agent used is f! of the hardening agent. It varies depending on the type i, and for example, when polyamines are used, the ratio of the epoxy equivalent to the active hydrogen equivalent is used as a guideline. A curing accelerator may also be used if necessary.

When used as a paint, a general-purpose colorant (pigment)
, fillers, solvents, defoaming agents, etc., and in the case of casting materials, various fillers can be used. When used as an epoxy resin composition for laminates,
Generally, aromatic hydrocarbons such as toluene and xylene,
It is prepared in the form of a festival using a solvent such as ketones such as aretone, methyl ethyl ketone, and methyl isobutyl ketone. The prepared epoxy resin composition is impregnated into a reinforcing base material such as glass cloth, carbon fiber, glass fiber, paper, asbestos, polyester fiber, aromatic polyamide fiber (trade name: Kevlar), and this is used as a prepreg. After that, it is heated and pressed in a press to form a laminate.

When producing a cured product from the trifunctional epoxy resin of the present invention, known epoxy resins such as bisphenol-type epoxy resin, alicyclic epoxy resin, halogen-containing bisphenol-type epoxy resin, phenol novolac-type epoxy resin, orthocresol novolac-type epoxy resin, etc. epoxy resin,
It can also be blended into the epoxy resin of the present invention in an amount within a range that does not impede the excellent properties of the epoxy resin of the present invention.

Example 1 1.1.3-)-Lis(2-methyl-4-hydroxy-
450 g of 5-tertiary butylphenyl)butane.

1150 g of epichlorohydrin and 6.81 g of tetramethylammonium chloride in a capacity of 2 I equipped with a stirrer and a reflux condenser! The mixture was charged into a four-hole glass flask and reacted at 100°C for 3 hours.

Thereafter, the mixture was cooled to 70° C., and 197 g of a 48% aqueous sodium hydroxide solution was continuously added dropwise over 2 hours while maintaining this temperature. At this time, reduce the pressure in the system to 130 to 290
The pressure was reduced to mmHg, and the produced water was removed from the system, and the azeotropic epichlorohydrin was returned to the system. After the dropwise addition was completed, water was removed from the system until no water was observed to be produced, and unreacted epichlorohydrin was then distilled out of the system. 400g of xylene and 480g of water for the residue
was added and stirred to transfer the generated common salt to the aqueous phase, and then allowed to stand, and the separated aqueous phase was removed.

Next, 7.6% of a 48% sodium hydroxide aqueous solution was added to the oil phase.
After stirring at 90° C. for 2 hours, 5 g of 30% aqueous sodium dihydrogen phosphate mQ7N 54 was added to perform neutralization. Thereafter, the mixture was allowed to stand to separate an oil phase and an aqueous phase, and after the aqueous phase was removed, water was removed by azeotropic distillation and salts were filtered out using a 4G filter.

Xylene was completely removed from the oil phase under reduced pressure of 5 mmHg and 150°C, and 1.1.3-)-lis(2-methyl-4-glycidoxy-5-tertiary butyl) having an epoxy equivalent of 263 and a softening point of 98°C was obtained. 510 g of phenyl)butane were obtained. Infrared absorption spectrum (KB
, tablets) are shown in FIG.

Application example 1 100 parts by weight of the epoxy resin 2 obtained in Example 1, 66 parts by weight of methylnorbornene-2,3-dicarphonic anhydride [Kayaba FMCD, manufactured by Nippon Kagami Co., Ltd.], and 2-ethyl-4-methyl Imidazole [Manufactured by Shikoku Kasei Kogyo ■, 2E
4MZ) 1 part of 1 ml was heated at 100°C for 3 hours and then at 230°C.
The mixture was heated and mixed for 2 hours to cure. The following properties of the obtained cured product were measured.

Glass transition υ temperature: Based on differential scanning calorimetry.

Bending strength: According to JrS 16911.

Flexural modulus: According to JISK-6911.

The results are shown in Table 1.

Application example 2 50 parts by weight of the epoxy resin obtained in Example 1, bisphenol A type epoxy resin [manufactured by Mitsui Petrochemical Industries, Ltd., EP
OMIK R-140) 50 parts by weight, 78 parts by weight of methylnorbornene-2,3-dicarboxylic anhydride and 2
- using 1 part by weight of ethyl-4-methylimidazole,
It was cured in the same manner as in Application Example 1, and the physical properties of the obtained cured product were measured. The results are shown in Table 1.

Comparative Application Example 1 Orthocresol novolac was mixed with 100 parts by weight of epoxy resin (Nippon Kajimi Co., Ltd., EOCN-104, epoxy equivalent 213, softening point 91°C), methylnorbornene-2,3-
81 parts by weight of dicarboxylic anhydride and 2-ethyl-4-
Using 1 part by weight of methylimidazole, it was cured in the same manner as in Application Example 1, and the physical properties of the obtained cured product were measured. The results are shown in Table 1.

Comparative application example 2 1.1.3-1-Lis(3,5-dimethyl-4-glycidoxyphenyl)propane (epoxy equivalent: 206, softening point: 56°C) 100 parts, methylnorbornene-2,3
-83 parts by weight of dicarboxylic anhydride and 2-ethyl-4
- Using 1 part by weight of methylimidazole, it was cured in the same manner as in Application Example 1, and the physical properties of the obtained cured product were measured.

The results are shown in Table 1.

Table 1

[Brief explanation of the drawing]

Figure 1 shows the 1,1,3-tris(2) obtained in Example 1.
-Methyl-4-glycidoxy-5-tertiary butylphenyl)butane is an infrared absorption spectrum diagram.

Claims (1)

[Claims] (1) General formula below ▲ Numerical formulas, chemical formulas, tables, etc. are included ▼ In the formula, R_1 is a hydrogen atom, methyl group, or tertiary butyl group, R_2 is a tertiary butyl group, and R_3 is a hydrogen atom or a lower alkyl group containing 1 to 4 carbon atoms, and R_4 is a hydrogen atom or a lower alkyl group containing 1 to 4 carbon atoms, and they may not all be the same. A novel heat-resistant epoxy resin characterized in that it is a trifunctional epoxy resin obtained from a trisphenol compound represented by the following formula and epihalohydrin or β-methylepihalohydrin.