JPH0122847B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to an epoxy resin composition, and more particularly to a liquid epoxy resin composition that can be completely cured at a relatively low temperature and has excellent heat resistance and peel strength. Conventionally, adhesives that cure at room temperature or relatively low temperatures below 80°C have had the disadvantage that those with high heat resistance have weak peeling force, and those with strong peeling force have low heat resistance. Conventional film adhesives have relatively excellent heat resistance and peel strength, but the shape of the surface to be bonded is limited to flat surfaces, it is necessary to use heat of 120°C or higher, and the work requires equipment. From the above points, it has the disadvantage of being complicated. The present invention was made to overcome these drawbacks, and aims to provide a composition that cures at a relatively low temperature and has excellent heat resistance and peel strength, and is particularly useful as an adhesive. As a result of intensive studies, the inventors of the present invention have found that NBR-based epoxy gun fat, which has an epoxy group introduced into the inner chain of the molecule of acrylonitrile-butadiene copolymer rubber (NBR), polyfunctional epoxy resin, bisphenol A, epichlorohydrin type epoxy resin (bisphenol A and epichlorohydrin), a liquid NBR having an epoxy group or an amino group at the end, and a specific amount of an aliphatic amine having both a primary amino group and a tertiary amino group in the molecule. The inventors have found that the object is satisfied and have arrived at the present invention. That is, the present invention provides (A) an epoxy resin obtained by adding two or more epoxy groups to the inner chain of the molecule of NBR, (B) an epoxy resin having three or more epoxy groups in the molecule, and (C) bisphenol. Diepoxide resin obtained from A and epichlorohydrin, (D) NBR resin having an epoxy group (D-1) or an amino group (D-2) at both ends of the main chain, and (E) a primary amino group in the molecule. An epoxy resin composition containing an aliphatic amine having both a tertiary amino group and a tertiary amino group, wherein (A) 10 to 85 parts by weight of component, 10 to 85 parts of component (B)
75 parts by weight, 5 to 75 parts by weight of component (C) and component (D) [(D-1) component and/or (D-2) component]
are blended in a proportion of 0.5 to 50 parts by weight, and component (A),
Component (D-2), component (E) and other optional components based on the total number of moles (G) of epoxy groups in component (B), component (C), component (D-1) and other optional components The component (E) is blended so that the ratio ((F)/(G)) of the total number of moles (F) of active hydrogen that can react with the epoxy groups therein is 0.5 to 1.0. The above epoxy resin composition. The epoxy resin composition of the present invention is used as a structural adhesive for structures that require high heat resistance and high peeling force as an adhesive that is applied and aged at a temperature of 80°C or lower, and is in liquid form. Therefore, it is particularly effective for precise bonding of curved surfaces. It can also be used as a casting material for castings that require high dimensional accuracy. In the present invention, the epoxy resin obtained by adding two or more epoxy groups to the inner chain of the NBR molecule refers to the epoxy resin obtained by carboxylating the cyano group in the side chain of NBR by a normal method, and bisphenol type epoxy resin (two or more It is an epoxy resin obtained by adding functional groups. In addition, (B) epoxy resin having three or more epoxy groups in the molecule refers to diamine compounds such as 4,
Epoxy resin or novolac obtained by condensation of 4'-diaminodiphenylmethane, metaxylylene diamine, 4,4'-diaminodicyclohexylmethane, paraphenylene diamine, 4,4'-diaminodiphenyl sulfone, etc. and epichlorohydrin. A novolac epoxy resin obtained by reaction of a resin with epichlorohydrin is used. Generally, this epoxy resin is preferably liquid, that is, one with a melting point of 0° C. or lower, but even a resin that is solid at room temperature can be used by melting and dissolving it in a liquid bisphenol A epichlorohydrin type epoxy resin. Further, two or more of these polyfunctional epoxy resins can be used in combination. The diepoxide resin (C) obtained from bisphenol A and epichlorohydrin in the present invention refers to diglycidyl ether compounds obtained by the reaction of bisphenol A and epichlorohydrin, such as Epicote 828, 834,
1001, 1004, 1007, 1009, 1045 (registered trademark, epoxy resin manufactured by Shell Chemical Co.), etc. In the present invention, two or more of these epoxy resins may be mixed. In addition, (D) NBR resin having epoxy groups or amino groups at both ends of the main chain is a resin obtained by adding bisphenol A diglycidyl ether to a NBR polymer carboxylated at both ends. or terminally carboxylated
Refers to a resin obtained by reacting NBR with a difunctional amine compound such as aminoethylpiperazine. (E) As the aliphatic amine having both a primary amino group and a tertiary amino group in the molecule, a compound having the structural formula shown below is used. In the present invention, all of the above-mentioned components (A) to (E) are essential, and the blending amounts are: component (A),
For 100 parts by weight of the total amount of component (B) and component (C),
10 to 85 parts by weight of component (A), 10 to 75 parts by weight of component (B),
It is necessary to blend component (C) in a proportion of 5 to 75 parts by weight and component (D) in a proportion of 0.5 to 50 parts by weight. If component (A) is less than 10 parts by weight, the peel strength will be poor, and if it exceeds 85 parts by weight, the heat resistance will be somewhat poor and the peel strength will drop considerably. If the amount of component (B) is less than 10 parts by weight, the peel strength will be significantly lowered, and if it is more than 75 parts by weight, the heat resistance will be slightly improved but the peel strength will be significantly lowered. When the amount of component (C) is less than 5 parts by weight, not only the peel strength but also the heat resistance is lowered, and when it exceeds 75 parts by weight, although the heat resistance is slightly improved, the peel strength is significantly lowered. Addition of component (D) is effective in improving the adhesive strength between the metal and the adhesive interface, but if it is less than 0.5 parts by weight, the peeling force will decrease, and if it exceeds 50 parts by weight, it will cause tensile shearing at room temperature and high temperature. Power is significantly reduced. In this way, (A) to (D) 4
It is necessary to include these components, and the resulting epoxy resin composition will have high properties only if the amounts thereof are within a specific range. The addition of component (E) is necessary to improve the heat resistance of the cured product, and when used as an adhesive, it improves the wettability between the adherend and the adhesive, resulting in good adhesion. give. The amount of component (E) added is determined by the ratio of the total number of moles of active hydrogen (F) that can react with the epoxy groups in the epoxy resin composition to the total number of moles of epoxy groups (G) in the epoxy resin composition, i.e. The (F)/(G) ratio is
It is added in a range of 0.5 to 1.0. (F)／(G)
When the ratio exceeds 1.0, peel strength increases, but heat resistance rapidly decreases. Moreover, if the ratio is less than 0.5, the peel strength will be significantly lowered, which is not preferable. In addition, in the present invention, it is possible to add other components having an epoxy group in addition to the essential components (A), (B), (C), and (D-1) having an epoxy group. ), it is also possible to add other components having amino groups in addition to component (E), but in any case, if the other components are added in an amount exceeding 20 equivalent % of the composition, the present invention will not be effective. No effect will be obtained.
Other epoxy group-containing components include polyglycidyl ethers of phenol formaldehyde novolac having an average of 36 oxirane groups in the molecule, such as commercially available resins with the trade name "DEN438" or diglycidyl ethers of polypropylene oxide, such as "DER736". Polyglycol polyepoxides, such as commercially available resins such as "Epon872", which are synthesized by the reaction of bisphenol A diglycidyl ether and aliphatic dimer acids, These are so-called alicyclic epoxy resins having epoxy groups, such as "ERL-4221". Other amino group-containing components include aliphatic amines such as ethylenediamine, ethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, dimethylamine, diethylamine, N,N'-diethylethylenediamine, and methyliminobis. propylamine,
Bis(hexamethylene)triamine, cyanoethylated polyamine, etc., and aromatic amines such as p-phenylene diamino, benzidine, 4,
4'-diaminodiphenylmethane, stilbendiamine, 4,4'-diaminostilbene, toluidine, 4,4'-methylene-bis-orthochloroaniline, 4,4'-diaminodiphenyl ether,
4,4'-diaminodiphenyl disulfide, 4,
4'-diaminophenyl sulfone, metaphenylene diamine, metaxylylene diamine, diamino pyridine, 2,4-diamino-1,3,5-triazine, melamine, etc. Other amines include menthanediamine, N-amino Ethylpiperazine, 1,3-diaminocyclohexane, isophoronediamine, N,N'-bis(oxyethyl)diethylenetriamine, N(oxyethyl)diethylenetriamine, N(2-oxypropyl)ethylenediamine, imidazoline, various imidazole compounds, as well as trimethylamine, triethylamine, tri-n-propylamine, benzyldimethylamine, α-methylbenzyldimethylamine,
2-dimethylaminomethylphenol, 2,4,
6-tris(dimethylaminomethyl)phenol, hexamethylenetetramine, triethylenediamine, N-methylmorpholine, pyridine, β-
Examples include tertiary amines such as picoline, quinaldine, N,N'-dimethylaniline, N,N'-dimethylpiperane, and triethanolamine, as well as dicyandiamide, biguanidide compounds, dihydrazide compounds, acrylamide, t-butylacrylamide, etc. and amide compounds such as polyamide. In the present invention, an adduct of a component having an amino group and a component having an epoxy group is created,
They can also be used in combination. The adduct is obtained by a conventional method, and is obtained by adding individual components having an epoxy group or a mixture thereof to excess amine and reacting them. The above used in the epoxy resin composition of the present invention
Extenders, fillers, pigments, etc. are used as compounding agents other than the five components (A) to (E), such as coal tar, glass fiber, asbestos fiber, boron fiber,
Carbon fiber, cellulose, polyethylene powder, polypropylene powder, quartz powder, mineral silicates such as mica, asbestos powder, and slate powder, kaolin, aluminum oxide trihydrate, aluminum hydroxide, chiyolk powder, gypsum, calcium carbonate. ,,
antimony trioxide, zinc oxide, bentone, silica aerosol, lithon, barite, titanium dioxide, carbon black, graphite, portland cement, oxide color pigments such as iron oxide,
Alternatively, there are metal powders such as aluminum powder, iron powder, copper powder, etc., and any of these can be used depending on the purpose. Additionally, solvents such as benzene, toluene, xylene, methyl isobutyl ketone, methyl ethyl ketone, cellosolve, etc., ester plasticizers such as ethylhexyl phthalate, dibutyl phthalate, ethylene glycol dibenzoate, ether plasticizers such as bisphenol A, ethylene oxide, propylene, etc. Plasticizers such as those added with several oxides and terminated with monool, phosphate ester salts such as tricresyl phosphate, and halogenated hydrocarbons such as chlorinated paraffin may be added. . Furthermore, tertiary amines, phenol compounds, which are conventionally known as curing accelerators for epoxy resins,
Alcohols and other Lewis acids may be added. Hereinafter, the present invention will be specifically explained based on Examples and Comparative Examples, but the present invention is not limited thereto. Note that all compounding units in Table 2 are parts by weight. Examples 1 to 14 and Comparative Examples 1 to 10 Each component shown in Table 1 was combined (A) to (D) in Table 2.
A viscous liquid epoxy resin composition was obtained by thoroughly mixing the components or other components with a paint mill. (C) When there are two or more components, melt and mix them at 160°C or higher in advance, then cool to room temperature,
Add components (A) and (B) to this and mix with a paint mill, then add components (D) and (E) and knead for more than 10 minutes on a glass plate to obtain the viscous liquid epoxy resin composition. get. When an adduct is used, the epoxy group-containing component is reacted with the amino group-containing component at a desired adduct ratio, and this is mixed with the remaining epoxy group-containing component to obtain the composition. The viscous liquid epoxy resin composition obtained in this way is applied to a metal piece for a test piece whose surface has been etched with chromic acid, fixed on a jig, and detonated at a rate of 0.2 to 0.3 kg/cm ² . Leave it crimped indoors overnight. This test piece was placed in a constant air bath and post-cured for 2 hours at 80±1°C. After this, the properties of the cured test piece were measured and a second
Shown in the table. Properties were evaluated using T-peel, normal temperature and high temperature tensile shear force, and T-peel, normal temperature and high temperature tensile shear force were measured in accordance with MMM-A-132. In addition, (F)/(G) is the total number of moles of active hydrogen that can react with the epoxy groups in the epoxy resin composition (F) relative to the total moles of epoxy groups in the epoxy resin composition (G).
This is the ratio of

【table】

【table】

【table】

[Table] As shown in Table 2, within the scope of the present invention (D)
In Examples 1 to 4, in which the ingredients and the blending amount of component (E) were changed, and the material of component (C) was changed, T-type peeling,
Tensile shear strength at room temperature and high temperature is in a desirable range. In Comparative Example 1, component (D) was not added, so it was inferior in T-shaped peeling, whereas in Comparative Example 2, a large amount of component (D) was blended, so it was inferior in tensile shear strength at room temperature and high temperature. In Comparative Example 3, component (D) was not added and the (F)/(G) ratio was
This is an example of 1.0 or more, but the tensile shear strength at room temperature and high temperature is extremely poor. Comparative Example 4 is an example in which component (D) was not added and the (F)/(G) ratio was less than 0.5, but T-shaped peeling was extremely poor. Comparative Example 5 is an example in which polyamide amine (l) was added instead of component (E), but the tensile shear strength at room temperature and high temperature was poor. Comparative Examples 6 and 7 are also examples in which 1,3-bisaminomethylcyclohexane (k) and liquefied diaminodiphenylmethane (m) were added in place of component (E), respectively. Not only the tensile shear force but also the T-shaped peeling was extremely poor and interfacial peeling occurred. In Examples 5 to 7, the blending amounts or materials of components (A) to (E) were changed, but all exhibited desirable physical properties. In Example 7, a relatively large amount of zinc oxide (n) was added in addition to components (A) to (E), but no influence was seen on the physical properties. Examples 8 to 10 are examples using adduct bodies, and all exhibited favorable physical properties. Comparative Example 8 was an example in which component (A) was not added, but T-shaped peeling was poor and interfacial peeling occurred. Examples 11 to 13 are examples in which the amounts of components (A) to (C) were particularly varied, and all exhibited desirable physical properties. Comparative Example 9 was an example in which component (B) was not added, and Comparative Example 10 was an example in which component (C) was not added, but in both cases, T-shaped peeling was poor and interfacial peeling occurred. Example 14 is an example in which NBR resin (g) having an epoxy group at the end was used as component (D), and favorable physical properties were also obtained in this case. As explained above, the present invention is a liquid composition that has excellent heat resistance and peel strength and can be completely cured at a relatively low temperature of 80°C. Therefore, in place of conventional room-temperature curing adhesives, which have been used at the expense of heat resistance or peel strength, it is necessary to avoid high temperatures during construction due to dimensional accuracy or material deterioration. It is suitable for use as a structural adhesive in fields where force is required, and because it is liquid, it can be applied to adhesive surfaces with complex shapes, and is also useful as a casting material for cast products. be.

Claims (1)

[Scope of Claims] 1 (a) an epoxy resin obtained by adding two or more epoxy groups to the molecular side chain of an acrylonitrile butadiene copolymer rubber; (B) an epoxy resin having three or more epoxy groups in the molecule; resin, (C) diepoxide resin obtained from bisphenol A and epichlorohydrin, (D) acrylonitrile butadiene copolymer resin having epoxy or amino groups at both ends of the main chain, and (E) primary in the molecule. An epoxy resin composition containing a fatty acid amine having both an amino group and a tertiary amino group, wherein (A) is ) component 10 to 85 parts by weight, component (B) 10 to 85 parts by weight
75 parts by weight, 5 to 75 parts by weight of component (C) and component (D)
The total number of moles of active hydrogen that can react with the epoxy groups in the epoxy resin composition (F ) ratio ((F)/(G)) is 0.5~
1.0.