JPS59136320A - Epoxy resin composition - Google Patents

Abstract

PURPOSE:To provide an epoxy resin composition having excellent heat resistance, mechanical and electrical properties, and transparency, and suitable for lamination, etc., by using an epoxy resin obtained by modifying triglycidyl isocyanurate, a polyepoxide compound and dicyandiamide as the components. CONSTITUTION:The objective composition contains (A) an epoxy resin prepared by reacting 1mol of neopentyl glycol of formula I with 2mol of hexahydrophthalic anhydride of formula II, and reacting the resultant diester dicarboxylic acid of formula III with 2-4mol of triglycidyl isocyanurate, (B) preferably 30- 250pts.wt., based on 100pts.wt. of the component A, of a polyepoxide compound (e.g. a reaction product of bisphenol A and epichlorohydrin) and (C) dicyandiamide. EFFECT:Since inexpensive and harmless dicyandiamide is used as a hardner in place of toxic aromatic diamine, the composition has high safety.

Description

Detailed Description of the Invention The present invention consists of an epoxy resin (A) modified with triglycidyl isocyanurate, a polyepoxide compound (B) and dicyandiamide (C), and is suitable for impregnation and lamination resins, adhesives, paints and casting. The present invention relates to thermosetting resin compositions used in products and the like.

In recent years, there has been an increasing demand for higher performance resin materials, and this also applies to epoxy resins.

Heat resistance 0 It is desired to improve mechanical properties, electrical properties, etc., but in order to improve the above properties, aromatic diamines, which are highly toxic and require special consideration when used as a curing agent, are used as curing agents. is said to be used. Therefore, it has been eagerly desired to obtain a composition that has good properties such as heat resistance by using a curing agent that is less toxic, hardly freezes, and is inexpensive.

In view of these points, the present inventors have developed an epoxy resin composition that does not use aromatic diamine, which is problematic due to its toxicity, as a curing agent, and has excellent heat resistance, zero mechanical properties, and electrical properties. As a result of further studies, we have arrived at the present invention.

That is, 1 the present invention is an epoxy resin (Al) obtained by reacting 17 neopentyl glycol and 2 moles of hexahydrophthalic anhydride, and further reacting 2 to 4 moles of triglycidyl in cyanurate; ), and (2) an epoxy resin composition characterized by containing dicyandiamide (C).

The present inventors believe that this composition does not use aromatic diamine, which is problematic due to its toxicity, as a curing agent, but uses dicyandiamide, which has low or almost no toxicity and is inexpensive, and has particularly improved heat resistance. 1. We have discovered that the epoxy resin composition has excellent mechanical properties as well as electrical properties. 1. We have completed the present invention. Furthermore, the composition of the present invention has 0
It has also been found that the composition has a new characteristic of being superior in transparency compared to ordinary epoxy resin compositions.

Component (A) used in the epoxy resin composition of the present invention is an epoxy resin modified with triglycidyl isocyanurate. L-liglycidyl isocyanurate has been known as an epoxy resin raw material with excellent heat resistance, weather resistance, and electrical properties at high temperatures, but it has a relatively high melting point (
) 100°C), and has extremely poor solubility in the various solvents currently used for epoxy resins, such as acetone, methyl ethyl ketone, ethyl cellosolve, butyl acetate, etc., and is still incompatible with other epoxy resins. It has the disadvantage that it is difficult to obtain a uniform solution-mixed composition because of the poor viscosity.

Therefore, it has been difficult to apply the resin to the wide range of applications that general epoxy resins have, such as adhesives, paints, and molding applications.

The present inventors solved these difficulties by reacting 1 mole of neopentyl glycol with 2 moles of hexahydrophthalic anhydride and further reacting with 2 to 4 moles of triglycidyl isocyanurate to obtain an epoxy resin. solved.

That is, the reaction between 1 mole of neopentyl glycol and hexahydrophthalic anhydride mainly reacts as follows to obtain a diester dicarboxylic acid.

The epoxy resin obtained by reacting the diester dicarboxylic acid with triglycidyl isocyanurate with 2 to 4 moles of triglycidyl isocyanurate has a lower melting point than that of triglycidyl in cyanurate, and can be used in organic solvents such as acetone, methyl ethyl ketone, ethyl It was found that it dissolves well in cellosolve, tetrahydrofuran, dimethylformamide, etc. In addition, general polyepoxide compounds 1 such as bisphenol A type epoxy resin, bisphenol FW epoxy resin,
Bisphenol A alkylene oxide addition type epoxy resin, hydrogenated bisphenol A type epoxy mJlW, Jl [
It has been found that it exhibits good compatibility with phenol A-type epoxy resins, phenolic epoxy resins, alicyclic epoxy resins, butadiene-modified epoxy resins, and the like. When the amount ratio of triglycidyl isocyanurate to the diester-dicarboxylic acid is 4 moles or more,
Solubility in organic solvents, compatibility with other epoxy resins, or lowering of melting point is insufficient.

Further, when the amount ratio of triglycidyl isocyanurate is 2 moles or less, the heat resistance and mechanical properties of the cured product are poor.

Good properties cannot be obtained in terms of electrical properties, etc.

As the polyepoxide compound of component (B) in the present invention, known compounds can be used.

For example, bisphenol A, resorcinol, bis-(P-
A polyepoxide compound obtained by reacting a polyhydric phenol such as oxyphenyl)methane, 2-2-bis-(4'-oxy 5/5/-dibromophenyl)propane with epichlorohydrin, phenol or cresol and formaldehyde under acidic conditions. Examples include polyepoxide compounds obtained by further reacting the condensation product obtained by reacting with epichlorohydrin, polyglycidyl esters of hydroaromatic carboxylic acids, polyglycidyl esters and ethers of alicyclic alcohols.

Components (Al and component (B) in the thermosetting composition of the present invention
The composition ratio of component (B) to 1 part by weight of component (A) IO can be appropriately selected depending on the application and desired heat resistance. It is preferable to choose. If component (B) is below 30%, the composition using dicyandiamide as a hardening agent is insufficient in terms of bending strength at high temperatures;
If the paper weight is 50 or more, the desired performance of the present application will not be achieved sufficiently.

Dicyandiamide (C) is used as a curing agent, and its product: is an epoxy selected from the above two groups; 1)
It is preferable to set it as 8-20y with respect to 1 gram equivalent of epoxy groups of I fat.

In addition to the above six components, the curable composition of the present invention may optionally contain a curing accelerator and an extender.

Fillers, reinforcing agents, pigments, organic fillers, 0T plastics.

Flow regulators, flame-resistant substances, etc. can be added. Examples of the curing accelerator include 6th class amines such as d-benzyldimethylamine, imidazoles such as N-methylimidazole, and hydrazides such as cono-phosphoric acid hydrazide.

Examples of extenders, fillers, and reinforcing agents include inorganic compounds such as talc, Ceracola 1 quartz powder, alumina, gamma lyca, mica, and inorganic fibers such as glass fibers and carbon fibers.

Suitable organic solvents for impregnating and applying the laminate-curing composition to adhesives, etc. include acetone, methyl ethyl ketone, dimethyl formamide, dimethyl acetamide, etc.; In order to improve the properties, it is preferable to select a mixed solvent of the above-mentioned solvents.

The epoxy resin composition of the present invention is used inter alia in the field of impregnation, laminates, adhesives and paints, but also in the field of cast molded and compression molded products. Moreover, it does not use aromatic diamides, which are problematic due to their toxicity, as a curing agent, and is particularly improved in heat resistance and transparency, and exhibits excellent mechanical and electrical properties.

Hereinafter, the present invention will be specifically explained with reference to Examples.

Example (1) Synthesis stirrer for diester dicarboxylic acid, I
Hexahydrophthalic anhydride 41a620y (4,
02 mol) and neopentyl glycol 209.5
After taking Y (2.01 mol) and thoroughly purging the inside of the flask with nitrogen.

Heat. Fifty minutes after the start of heating, the temperature was raised to 140°C, and the mixture was further reacted at 140°C for 90 minutes, and then cooled. Slightly yellowish color with acid equivalent weight of 204. A glassy product was obtained at room temperature.

(2) Synthesis of epoxy resin (A) Triglycidyl in cyanurate (Nissan Chemical Co., Ltd. H) having an epoxy equivalent of 101 was added to a flask equipped with a stirrer, a thermometer, and a nitrogen gas inlet tube.
After removing f and sufficiently purging the inside of the flask with nitrogen, it is heated and melted.

The diester dicarboxylic acid 6452 synthesized in (1) is placed in a dropping funnel and heated to about 130°C in advance, and when the temperature of the molten triglycidyl isocyanurate reaches 135°C, the diester dicarboxylic acid is added dropwise.

While adjusting the temperature of the reaction mixture to 140°C,
Diester dicarboxylic acid was added dropwise over 50 minutes. After further reacting at 140°C for 30 minutes, the reaction product (A) (epoxy resin (A) was poured into a stainless steel vat.
shall be. ) were collected. This reaction product is 60-65℃
It is a colorless and transparent solid with a melting point of . The epoxy equivalent was 255, and it was completely dissolved in frozen acetone, methyl ethyl ketone, dimethyl formamide, etc. Using this epoxy resin (A)k, a laminate was made as described below.

Bending properties, transparency and volume resistivity were measured.

Note that all "parts" below mean "parts by weight."

Epoxy resin (component (A)) 100 parts, Ehiko) +8
28 (manufactured by Shell Chemical Co., Ltd., dicrycidyl ether of bisphenol A component (B)) 100 parts, dicyandiamide (component (C)) a, part a, N.

N-dimethylbenzylamine 04 parts, acetone 44 parts,
Pheno was prepared from 70 parts of dimethylformamide. Pheno was a colorless and transparent solution. Glass cloth (manufactured by Nittobo, WE18, 104BZ2) with dimensions 26 + milk
21 A piece cut into I6 size was impregnated with the above pheno, and after air drying, it was precured in an open air at 160°C.
Staged) Noripreg cloth was created. That's 21
Cut into L angle, stack 9 sheets at 170°C, 20"l/;1
, Pressed for 11 minutes, and further post-cured at 170°C for 1 hour. A test piece was cut out from the laminate thus obtained, and its physical properties were measured. The results are shown in Table 1.

Example 2 and the epoxy resin (A) synthesized in Example 1 (2).

Table 1 by changing the ratio of Epicor) San828 (component (B))
A phenol having the composition shown in was prepared, a laminate was prepared in the same manner as in Example 1, and its physical properties were measured. As shown in Table 1, the laminate has a much higher bending strength retention rate when heated than the comparative example, and has excellent heat resistance, as well as excellent transparency.

Comparative Example A phenol was prepared using Epicote Φ1001 (component (B)) (manufactured by Shell) with the composition shown in Table 1, and a laminate was prepared in the same manner as in Example 1, and the physical properties were measured. The results are shown in Table 1.

In addition, instead of Epicor + # + 1001, Epicor)
When $828 was used, the resin sagged significantly when the glass cloth impregnated with phenol was air-dried, and it was impossible to create a laminate from the cloth when B-staged.

Example 6 Diester dicarboxylic acid 905y synthesized in Example 1
and triglycidyl isocyanurate) 200.1
From f/, epoxy resin (
A) was synthesized.

The epoxy resin (A) was a colorless and transparent solid with a melting point of 60-70'C, and the epoxy equivalent was 192.

It also completely dissolved in acetone, methyl ethyl ketone, dimethyl formamide, etc. Using this epoxy resin (A), a phenol having the composition shown in Table 1 was prepared, a laminate was prepared in the same manner as in Example 1, and its physical properties were measured.

As shown in Table 1, a laminated board with excellent heat resistance and transparency was obtained.

13-

Claims (2)

[Claims] (1) 1 mol of neohentyl glycol and 2 mol of hexahydrophthalic anhydride are reacted. Epoxy resin (A) obtained by further reacting 2 to 4 moles of triglycidyl isocyanurate. An epoxy resin composition comprising a polyepoxide compound (B) and a dicyandiamide (0). (2) Based on 100 parts by weight of the above epoxy resin (A). The composition according to claim 1, wherein the polyepoxide compound (B) is 30 to 250 parts by weight.