JPS59147014A - Epoxy resin compositon - Google Patents

Abstract

PURPOSE:The titled composition curable at normal temperature, having improved adhesiveness at extremely low temperature, obtained by blending a specific epoxy resin mixed system with a specified curing agent mixed system in a specific ratio, adding a specific amount of an inorganic fibrous substance to at least one mixed system. CONSTITUTION:An epoxy resin mixed system consisting essentially of a nonalicyclic epoxy resin (e.g., glycidyl ether resin, etc.) having >=1.7 epoxy group per molecule on an average and about 70-1,000 epoxy equivalent is blended with a curing agent mixed system consisting essentially of 15-95wt% polyether polyamine such as polyoxyethyleneamine, etc. and 85-5wt% liquid acrylonitrile- butadiene copolymer having >=1.7 primary and secondary amino groups per molecule on an average in such a way that an amount of active hydrogen in amino group of the curing agent mixed system is 0.2-2.0 equivalent based on epoxy group, and at least one of the blended systems is blended with 10-65wt% inorganic fibrous material (e.g., asbestos, etc.) to give the desired epoxy resin composition.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a two-part epoxy resin composition that can be cured at room temperature and has excellent adhesive properties at extremely low temperatures.

BACKGROUND OF THE INVENTION With the spread of liquefied natural gas and technologies such as cryo-pulverization, frozen foods, and freeze-drying, an increasing number of structures are exposed to extremely low temperatures of minus 100 degrees Celsius. Joints of such structures are mainly joined by physical and mechanical methods. The reason for this is that very few reliable and excellent adhesives that can be used at extremely low temperatures have been found. In other words, at such extremely low temperatures, a large thermal stress is applied between the adhesive and the adherend, which causes a peeling phenomenon at the interface between the adhesive and the adherend, resulting in loss of adhesive strength. Cracks occur in the adhesive and the adhesive function is lost.

However, depending on the type of structure exposed to extremely low temperatures, physical or mechanical bonding may be impossible or difficult, and it is desirable to develop highly reliable adhesives that can be used under such conditions. ing.

An object of the present invention is to provide an epoxy resin composition that can be easily cured at room temperature and has excellent adhesion even at extremely low temperatures.

That is, this invention has an average of 1.7 or more epoxy groups per molecule, and an epoxy equivalent of about 70 to i,
15 to 95% by weight of a polyether polyamine having an average of 1.7 or more primary to secondary amino groups per molecule; A curing agent compounding system containing 85 to 5% by weight of a liquid acrylonitrile-phtadiene copolymer having an average of L7 or more primary or secondary amino groups per molecule, and the curing agent compounding system is The amount of active hydrogen in the 7 primary to secondary amide groups contained in the epoxy resin compound is 0.2 to 0.2 to
An epoxy resin composition characterized in that the ratio is set to be 2.0 equivalent, and one or both of the two blending systems contains an inorganic fibrous material in an amount of 10 to 65% by weight based on the entire composition. It is related to things.

The epoxy resin that constitutes the main component of the epoxy resin compounding system in this invention has an average of 1.7 or more molecules per molecule, preferably an average of 1.7 to 3.0 molecules, and more preferably an average of 1.7 molecules per molecule.
~2.3 epoxy groups and an epoxy equivalent (weight) of about 70 to 1,000, preferably about 70 to 50
0 non-alicyclic epoxy resin is used. If the number of epoxy groups is less than the above or the epoxy equivalent is outside the above range, a cured product with excellent mechanical strength etc. cannot be obtained, and alicyclic epoxy resins are unsuitable due to poor room temperature curability.

Examples of such non-alicyclic epoxy resins include: Namely, epoxidized cyclic silane, epoxidized soybean oil, polyglycidyl ester of polycarboxylic acid,
+ poxidized polyolefins and glycidyl ether resins. Among these, glycidyl ether resin is preferred.

Examples of the polycarboxylic acid polyglycidyl ester include diglycidyl ester of lyluin dimer acid and triglycidyl ester of lyluin trimer acid.

Suitable glycidyl ether resins include polyallyl glycidyl ether/lz, diglycidyl ether of chlorendiol, diglycidyl ether of dioxanediol, diglycidyl ether of endomethylenecyclohexanediol, epoxy novolak resins, alkanediol diglycidyl ether, alkanes. Examples include triol triglycidyl ether. More desirable glycidyl ether resins include alkanediol diglycidyl ethers represented by the following formula.

(In the formula, X is an alkylene or alkylidene group having 1 to 1 carbon atoms, preferably 2 to 6 carbon atoms, and n is 1 to
20, preferably 1-15. ) Suitable alkanediol diglycidyl ethers include ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, novelbutanediol diglycidyl ether, and the like.

Other more desirable glycidyl ether resins having 2 to 10 carbon atoms. In particular, there are alkanetriol triglycidyl ethers having 3 to 1o alkanetriyl groups, such as glyceryl triglycidyl eniter, triglycidyl ether of trimethylolpropane, and the like. Still other more desirable glycidyl ether resins are di- and polyglycidyl ethers of bisphenols represented by the following formula.

(In the formula, 艮 is a divalent radical containing at least 1 to 8 atoms selected from the group consisting of C, O, S, and N, preferably an alkylene or alkylidene group having 1 to 8 carbon atoms, more preferably is an alkylene or alkylidene group having 1 to 6 carbon atoms.) Among the above, suitable bisphenols include methylene bisphenol, impropylidene bisphenol, butylidene bisphenol, octylidene bisphenol,
Examples include bisphenol sulfide, hisphenol sulfone, bisphenol ester, and bisphenol amine. In particular, excellent results were obtained using improvylidene bisphenol.

Suitable glycidyl ethers include the di- and polyglycidyl ethers of isopropylidene bisphenol represented by the formula:

(In the formula, n is O to 20, preferably O to 2.) The polyether polyamine, which is the main component of the curing agent compound system of the present invention, has an average of 7 primary to secondary amide groups per molecule. It contains 1.7 or more pieces, preferably 1.7 to 4.0 pieces on average, and more preferably 1.7 to 3.3 pieces on average. Among such polyether polyamines, aliphatic ones are preferable, and such examples include polyoxyethylene amine, polyoxypropylene amine, etc.
EPOMIC Dodo Q692°/Q691 (manufactured by Mitsui Petrochemical Epohishi Co., Ltd.), Yudo Q6
93, Q694, etc.

The liquid acrylonitrile-butadiene copolymer having an amino group, which is the other main component of the curing agent blend system of this invention, is 1
On average 1.7-3, preferably 1.7-2.
It contains three primary to secondary amine groups,
Particularly preferably, those having the above-mentioned primary or secondary amino groups at at least both ends of the molecule are used. Such liquid copolymers generally contain a liquid acrylonitrile-butadiene copolymer having a carboxyl group, an ester group, or an acyl chloride group, and at least two primary to secondary copolymers.
It can be easily produced by reacting with at least one aliphatic, alicyclic or heterocyclic amine containing a class amine group. The general structural formula of a preferred liquid copolymer having 7 primary or secondary amide groups at both ends of the molecule is represented by the following formula.

0 0 111 Y-C-B-C-Y (wherein Y is an aliphatic, cycloaliphatic, heterocyclic or aromatic amine containing at least two primary or secondary diamino groups) (B is a monovalent radical obtained by removing hydrogen from group 7, and B is the copolymer main chain consisting of butadiene-acrylonitrile) Carboxyl group used to obtain such an amino group-containing liquid copolymer For example, a liquid copolymer having acrylonitrile 18 to
46% by weight, 82-54% by weight of butadiene and less than 15% by weight of carboxyl group-containing monomers. This liquid copolymer having a carboxyl group can be esterified with an aliphatic monohydric alcohol by a well-known method to obtain a liquid copolymer having an ester group. Further, the liquid copolymer having a carboxyl group can be converted into an acid chloride by a well-known method to form a liquid copolymer having an acyl chloride group.

The amine that reacts well with the liquid copolymer having a carboxyl group, ester group or acyl chloride group has at least 2, preferably 2 primary or secondary amine groups and has 1 carbon atom. ~20, preferably 1-12
There are aliphatic amines. Also suitable are cycloaliphatic amines having at least 2, preferably 2 primary or secondary amino groups and having 4 to 20, preferably 4 to 12 carbon atoms. Furthermore, it has at least 2, preferably 2 primary or secondary amino groups, and has 2 to 2 carbon atoms.
It is also possible to use 20, preferably 2 to 12, heterocyclic amines.

Suitable examples of such amines include ethylenediamine, 1,2-propanediamine, 1,3-propanediamine, 1,4-butanediamine, 2-methyl-1,2-
Propanediamine, 1,5-pentanediamine, l.6
-hexanediamine, l・7-hebutanediamine, ■・
8-octanediamine, l-10-decanediamine, 1
・Aliphatic amines such as 12-dodecanediamine: diethylenetriamine, triethylenetetramine, tetraethylenepentamine, bis(hexamethylene)triamine, 3
・Aliphatic polyamines such as 3-iminobispropylamine: Alicyclic diamines and polyamines such as 1・2-diaminocyclohexane, ■・3-p-menthanediamine:
and 4-(aminomethyl)piperidine, piperazine, and N-(aminoalkyl)piperazine having 1 to 12 carbon atoms, preferably 1 to 6 carbon atoms in each alkyl group (e.g., N-(2-amineethyl)piperazine, (3-
Heterocyclic diamines and polyamines such as aminopropyl)piperazine, N,N-bis(3-aminopropyl)piperazine, etc.).

More preferred amines are those containing at least two 81- to secondary amine groups having different reactivities. When amine 7 groups with different reactivities are present, termination reaction by amine is more likely to occur than coupling between liquid copolymers, and moreover, the amount of excess amine required to avoid coupling may be smaller. Preferred amines include, for example:
Several alicyclic amines such as 1,3-P-menthanediamine, 4-(aminemethyl)piperidine and N-(aminoalkyl) having from 1 to 12 carbon atoms, preferably from 1 to 6 carbon atoms in the alkyl group. There are several heterocyclic amines such as piperazine (eg, N-(2-amineethyl)piperazine, N-(3-aminepropyl)piperazine, etc.). In particular, N
Good results are obtained with -(2-aminoethyl)piperazine.

The amount of liquid acrylonitrile-butadiene copolymer having an amine group added to the polyether polyamine is 5
It should range from 85% to 85% by weight. If used beyond this range, the expected effect may not be obtained. That is, if it is less than 5% by weight, it will not be possible to relieve the stress caused by curing shrinkage of the epoxy resin, and the adhesion will be poor when subjected to temperature changes.
If it exceeds 100%, the comb component becomes too large and the properties as an epoxy resin deteriorate, resulting in a decrease in adhesion.

The epoxy resin compounding system and curing agent compounding system of the present invention can contain various optional components in addition to the above-mentioned main components. Examples include reinforcing fillers such as carbon black, metal salts of carbonates and silicates, glass, asbestos and papers; inorganic and organic colorants such as metal oxides and metal chlorides; petroleum, castor oil. lubricants and plasticizers such as , glycerin, silicones, aromatic and paraffinic oils, and alkyl and aromatic esters such as phthalic acid, sebacic acid, trimellitic acid; G-E-butylhalacresol, 2.2'
-methylenebis(4-ethyl-6-t-butylphenol), 2,2-thiobis(4-methyl-6-[-butylphenol), 4,4'-butylidenebis(6-[-butyl-nl-cresol), tris (3・5-G[-
butyl-4-hydroxybenzyl)in cyanurate,
hexahydro3,5-tris-β-(3,5-';-
L-butyl-4-hydroxyphenyl)propionyl
Antioxidants and stabilizers such as triazine, tetrakis-methylene-3(3,5-di[-butyl-4'-hydroxyphenyl)propionate methane, distearyl thiodipropionate, tri(nonylated phenyl)phosphite It is a drug.

In addition, one or both of the two compounding systems, usually the curing agent compounding system, may contain a curing aid or curing agent for the purpose of promoting or assisting the reaction between the epoxy resin and the polyether polyamine or liquid copolymer. As a promoter, BF3
-amine complexes, hexahydrophthalic anhydride, dicyandiamide, imidazoles such as 2-ethyl-4-methyl-imidazole, triethylenetetramine, modified aliphatic polyamines, modified aromatic polyamines, etc. may be blended.

Furthermore, chain extenders, crosslinking agents, etc. can be blended, and such substances include dibasic acids such as azelaic acid and fumaric acid, and 1,6-hexanedithiol, 1,8-
There are dimercaptans such as octanedithiol. Furthermore, maleic anhydride, koic anhydride, phthalic anhydride,
Acid anhydrides such as hexanohydrophthalic anhydride; 4.4
-dicyclopentyl methylene isocyanate, 4.4'
- Diisocyanates such as diphenylmethylene diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 1,4-phenylene diisocyanate; ethylenediamine, 2,2-propanediamine, 1,3-propanediamine, 1,4 -butanediamine, 2-methyl-1,2-propanediamine, ■・
5-pentanediamine, 1,6-hexanediamine, 1
・7-hebutanediamine, ■・8-octanediamine,
Aliphatic amines such as 1,10-decanediamine, 1,12-toticanediamine, diethylenetriamine, ]・
Aliphatic polyamines such as lyethylenetetramine, tetraethylenepentamine, bis(hexamethylene)triamine, 3,3-iminobispropylamine; alicyclic polyamines such as 1,2-diaminocyclohexane, 1,8-P-menthanediamine Diamines and polyamines: 4-(ami/methyl)piperidine, piperazine, and N-( in which each alkyl group has 1 to 12 carbon atoms, preferably 1 to 6 carbon atoms)
aminoalkyl)piperazine (e.g., N-(2-aminoethyl)piperazine, N-(3-aminopropyl)piperazine, N,N'-bis(3-aminopropyl)
Heterocyclic diamines and polyamines such as piperazine; and 1,4-dibromobutane, 1,3-dibromobutane, 1,4-dichlorobutane, 1,2-dichloroethane, 1,4-shortbutane, 1,6- C1-C12 aliphatic dihalogenates such as dichlorohexane and the like, preferably C1-C8 aliphatic tribromides and/or dichlorides.

Other suitable and more desirable chain extenders and/or crosslinking agents include those having 6 to 2 carbon atoms;
4, especially dihydroxy aromatic compounds having 6 to 18 carbon atoms. These compounds include catechol, resorcinol, 3-hydroxybenzyl alcohol, 4-hydroxybenzyl alcohol, 1,3-dihydroxynaphthalene, 1,5-dihydroxynaphthalene, 1,7-dihydroxynaphthalene, and the like. Even more desirable is bisphenol represented by the following formula.

(wherein R is a divalent radical containing 1 to 8 atoms of at least one selected from the group consisting of C, O, S, and N, preferably an alkylene or alkylidene group having 1 to 8 carbon atoms, (Preferably, it is an alkylene or alkylidene group having 1 to 6 carbon atoms.) Suitable bisphenols include methylene bisphenol,
Examples include inpropylidene bisphenol, butylidene hisphenol, octylidene bisphenol, bisphenol zulfite, bisphenol sulfone, hisphenol ether, and bisphenol amine.

In this invention, it is important to further blend an inorganic fibrous material into one or both of the epoxy resin blend system and curing agent blend system consisting of the above-mentioned components. Examples of the inorganic fibrous material include asbestos, calcium silicate, glass fiber, carbon fiber, etc., and the fiber length is generally 1 micron or more, preferably 10 to 2 microns,
000 microns is used.

The blending amount of these inorganic fibrous substances is 0 to 65% by weight, preferably 15 to 60% by weight of the entire epoxy resin composition. No effect of addition was observed when 10% by weight was added, and 6
If it exceeds 5% by weight, the viscosity of the composition becomes too high, resulting in poor wetting to adherends and impaired adhesion.

The epoxy resin composition of the present invention configured as described above is easily cured at room temperature, and the resulting cured product exhibits excellent adhesion not only at room temperature but also at extremely low temperatures, and has excellent adhesion between both room temperature and extremely low temperatures. It is ideal as an adhesive for structures used at extremely low temperatures because its adhesion remains unchanged even after repeated large temperature changes.

Examples of this invention are shown below. Note that parts refer to parts by weight.

Examples and Comparative Examples Epicor) i28 (Bisphenol Au diglycidyl ether manufactured by Shell Chemical Co., Ltd.; Epoxy equivalent: 185-19
2. Average number of epoxy groups per molecule 1.9), to un-36 (propy V glycol type flexible epoxy resin manufactured by Dow; epoxy equivalent 175-205. Average number of epoxy groups per molecule 1.9), Milled fiber MF-A
(Glass fiber made by Asahi Fiberglass: 10 microns in diameter, 30-100 microns in length), 5s-so (
Calcium carbonate (manufactured by Nitto Funka Co., Ltd.) was mixed at 80°C in a stirring mixing pot at the mixing ratio shown in Table 1, and R-1 to I
A system containing seven types of epoxy resins, ζ-7, was used.

Table 1 On the other hand, Hiker ATBN (manufactured by Ube Industries, Ltd., containing approximately 16.4% by weight of acrylonitrile having 7 amino groups at both ends of the molecule,
Copolymer with butadiene content of about 67.2% by weight, active amine hydrogen equivalent 1,700, average number of amine groups per molecule 1.9), EPOMI C, Q 692 (polyether polyamine manufactured by Mitsui Petrochemical Epoxy Co., Ltd.; active Amine hydrogen equivalent 100 - average number of amine groups per molecule 1.9)
, Sanmide 315 (polyamide amine manufactured by Sanso Kagaku Co., Ltd.;
Active hydrogen equivalent: 125. Average number of amino groups per molecule: 5
．． 5), Milled fiber MF-A (described above), 5s-s
o (described above) were mixed at 60° C. in a stirring mixing pot at the mixing ratios shown in Table 2 below to obtain eight curing agent combination systems H-1 to H-8.

Using equal weights of the above epoxy resin blend system (R-1 to R-7) and curing agent blend system (H-1 to H-8),
Nine types of epoxy resin compositions, including a comparative example, were prepared by combining them as shown in the table.

This composition was mixed and cured, and the properties of the cured product at room temperature and cryogenic temperature (cryogenic cyclability, shear adhesive strength) were investigated as shown below.The results are shown in Table 3. Met.

<Cryogenic cyclability> As shown in Figure 1, it has a width of 50m and a length of 60+++m.

Mixture 2 in an unhardened state is poured onto a steel plate 1 with a thickness of 3.2 mm.
The coating was applied to a length of 40 rIn and a thickness of 2 cylinders, and left in an atmosphere of 50° C. for 10 days to harden. After creating a test piece in this way, the test piece is immersed in liquid nitrogen (-196°C) for 1 hour, and then this test piece is left in an atmosphere of 20°C for 2 hours. This is considered as one cycle, and 10 cycles are repeated, and it is observed whether or not cracks occur on the surface of the cured product and whether or not peeling occurs.

Shear adhesive strength〉 Figure 2 (As shown in Figure 8, the width is 30 mm, the length is 100 mm,
Apply the uncured mixture 4 to a JIS -3141 cold rolled steel plate 3 with a thickness of 1.6 to a width of 20 rrn, length of 15 rrn, and thickness of 0.5 run, and leave it in an atmosphere at room temperature for one month. and harden. The aforementioned cryogenic cycle is repeated 10 times on this test piece.

Thereafter, as shown in FIG. 2 (13), a mixture 5 of 100 parts of Epicoat ≠ 828 (described above) and 50 parts of Sanmide +3is (described above) was used as an adhesive on this test piece, and the cured mixture 4 It was applied to the surface 4a to a thickness of 0.1 mm or less, and the medium was 30 mm and the length was 100 mm.

JIS-C;-3141 cold rolled steel plate 6 with a thickness of 1.6
The two were placed on top of each other and pressed using two stationery double clips, and left at room temperature for 3 days to harden the adhesive.

After creating the test piece 7 for measuring shear adhesive strength in this manner, the shear adhesive strength of the cured mixture 4 was measured using Tensilon UTM-5000B (tensile tester manufactured by Toyo Baldwin) at a tensile rate of 150 rrn/min at 20°C. did.

Shear adhesive strength was similarly measured for test pieces that were not subjected to the cryogenic cycle after curing Mixture 4 at room temperature.

Table 3 a) A is a system containing an epoxy resin, and B is a system containing a curing agent.

b) C is no cryogenic cycle, D is cryogenic cycle 10
This is the value after

As is clear from Table 3, when the epoxy resin composition according to the present invention is used, a cured product exhibiting excellent adhesion even when exposed to an extremely low temperature atmosphere can be obtained.

[Brief explanation of drawings]

Figures 1 and 2 (A+, (B) are explanatory diagrams for explaining the method of testing the properties of cured products. Patent applicant: Nitto Electric Industry Co., Ltd. -%

Claims (1)

[Claims] (1) An epoxy resin compound system mainly composed of a non-alicyclic epoxy resin having an average of 1.7 or more epoxy groups per molecule and an epoxy equivalent of about 70 to 1,000, and a primary 15 to 95% by weight of a polyether polyamine having an average of 1.7 or more secondary amino groups per molecule and an average of 1 to 7 primary or secondary amino groups per molecule.
．． and a curing agent compounded system mainly composed of 85 to 5% by weight of a liquid acrylonitrile-butadiene copolymer having 7 or more acrylonitrile-butadiene copolymers, and the curing agent compounded system contains the above-mentioned primary to secondary amine groups. The amount of active hydrogen is set at a ratio of 0.2 to 2.0 equivalents relative to the epoxy groups in the epoxy resin blending system, and an inorganic fibrous material is included in either or both of the blending systems. 10~ of all things
An epoxy resin composition characterized by containing 65% by weight.