JPS6320317A - Epoxy resin composition - Google Patents

Abstract

PURPOSE:To obtain the title composition excellent in shear bonding strength and peel bonding strength, by mixing an epoxy resin with an alkoxymethyl group-substituted polyamide and a curing agent. CONSTITUTION:100pts.wt. epoxy resin (a) having an epoxy equivalent of 100-3,500 and, preferably, at least two epoxy groups in the molecule (e.g., bisphenol A epoxy resin) is mixed with 3-120pts.wt. N-alkoxymethyl group- substituted polyamide (b) of an MW of 1,000-70,000 and the formula (wherein R and R' are each an organic group, R'' is alkyl and m, n and l are integers), e.g., N-methoxymethyl group-substituted 6-nylon) and a curing agent (c) selected from among dicyandiamide types, imidazole types, acid anhydride types, phenol types, acid hydrazide types, boron fluoride compound types, amineimide types and tert. amine types and, optionally, cure accelerators, at most 5pts.wt. silane coupling agents, fillers, pigments, antioxidants, dispersants, etc. (d).

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to an epoxy resin composition, and its object is to provide an epoxy resin composition that has high shear adhesive strength and excellent peel adhesive strength. be.

[Conventional technology]

Epoxy resin has excellent properties such as electrical insulation, Wl + heat resistance, corrosion resistance, and adhesiveness, and its usage forms include liquid,
It is used in a variety of fields because it comes in paste, sheet, and powder forms. In addition, various formulations are sinterable, and the properties of the cured product can be varied depending on the purpose of use, which is one of the reasons why it is widely used.

However, even with epoxy resins having such excellent properties, it is difficult to achieve both contradictory properties of high shear adhesive strength and high peel adhesive strength.

In order to satisfy both of these characteristics, a composition consisting of an epoxy resin and a normal polyamide resin has been developed, but in this conventional composition, the epoxy resin and polyamide resin cannot be separated at a curing temperature of about 180°C or lower. Since it does not react and simply becomes a dispersed or molten state, no significant improvement in peel adhesion can be expected. In addition, in order to make the terminal firing groups of the epoxy resin and polyamide resin react with each other, the temperature is 200°C.
A higher curing temperature was required, and the range of application was naturally limited.

[Problem that the invention seeks to solve]

The problem to be solved by this invention is to develop an epoxy resin adhesive composition that has both high peel adhesion and high shear adhesion. An object of the present invention is to solve the above-mentioned disadvantages of the above-mentioned adhesive composition.

[Means for solving problems]

This problem is solved by using as polyamide in conventional compositions of epoxy resin and polyamide, in particular polyamides in which some of the amide groups have been replaced by alkoxymethyl groups.

That is, as a result of urgent studies to solve the above-mentioned problems, the inventors of the present invention solved the drawbacks of the above-mentioned prior art by using an epoxy resin, a polyamide resin in which a part of the amide group is substituted with an alkoxymethyl group, and a curing agent. We have found a solution to this problem and have come up with the present invention. That is, the present invention relates to an epoxy resin composition characterized by containing an epoxy resin, a curing agent, and an alkoxymethyl group-substituted polyamide.

[Structure and operation of the invention]

The epoxy equivalent of the epoxy resin used in the present invention is usually about 100 to 3,500, and those having an average of two or more epoxy groups in one molecule are preferably used. As such epoxy resin, bisphenol A type epoxy resin is suitable, but bisphenol F type epoxy resin, cycloaliphatic epoxy resin, hydantoin epoxy resin, novolac type epoxy resin,
Glycidyl ester type epoxy resin etc. alone or in combination
It is possible to use a mixture of more than one species.

The polyamide used in the present invention has the following general formula (A
) ...... (A) (However, in the formula, R and M are the same or different organic groups, R
' is an alkyl group, and m, n and l are the same or different integers) are used.

In other words, the polyamide represented by the general formula (A) can be said to have a part of the amide group in the molecule substituted with an alkoxymethyl group. When such a polyamide resin is used, the alkoxymethyl group reacts with the remaining active hydrogen of the amide group during heat curing of the epoxy resin, resulting in three-dimensional crosslinking of the polyamide resin. Therefore, the three-dimensional cured network of the epoxy resin and the three-dimensional cured network of the polyamide resin form an interpenetrating network, making it possible to achieve both the rigidity of the epoxy resin and the toughness of the polyamide resin. In this case, the alkoxymethyl groups of the polyamide may react with the hydroxyl groups in the epoxy resin during heat curing of the epoxy resin, and molecules of the polyamide resin may be contained in the epoxy resin curing line, but even with such a structure, the above-mentioned Similarly, it is possible to achieve both rigidity and toughness.

On the other hand, when a polyamide resin that does not contain alkoxymethyl groups is used, it does not react with the epoxy resin at normal curing temperatures, so the linear polyamide resin is simply dispersed in the three-dimensional cured network of the epoxy resin. It is difficult to achieve both rigidity and toughness.

Base resins for polyamide resins substituted with N-alkoxymethyl groups include 6-nylon, 6.6-nylon, and 6-nylon.
, 10-nylon, 1)-nylon, 12-nylon,
Examples include copolymerized nylon. Further, the content of alkoxymethyl groups is usually 10 to 45 mo1% in a polyamide resin, preferably 20 to 35 mo1% in a polyamide resin substituted with an alkoxymethyl group. In this case, R'' of the alkoxy group (CH20RN) can be exemplified by methyl, ethyl, propyl, etc., with methyl being particularly preferred.

As a polyamide resin, its molecular weight is 1000 to 700.
00, preferably about 5,000 to 30,000.

The amount of polyamide added is preferably 3 to 120 parts by weight per 100 parts by weight of the epoxy resin.
If the amount is less than 3 parts by weight, the polyamide resin cannot exhibit its toughness, and if it exceeds 120 parts by weight, the rigidity of the resin may not be maintained.

As the curing agent used in the present invention, since it is necessary to simultaneously advance the reaction of the alkoxymethyl group contained in the polyamide resin during the curing reaction of the epoxy resin, dicyandiamide-based curing agents for heat curing, imidazole, etc. type, acid anhydride type, phenol type, acid hydrazide type,
A boron fluoride compound type, an amine imide type, and a tertiary amine type are preferably used. Further, these curing agents may be used in combination with a curing accelerator as appropriate.

In the present invention, adhesion can be further improved by using a silane coupling agent as an additive. The reason for this is not necessarily clear, but it is thought that the use of a silane camping agent improves the wettability with the fully curved surface.

The silane coupling agent used here includes, for example, Silane compounds represented by hydrolyzable groups such as halogen and alkoxy groups are suitable, and specific examples include γ-aminopropyl triethoxysilane and vinyl triacetoxysilane.

Such a silane coupling agent is usually used in an amount of 5 parts by weight or less, preferably 0.2 parts by weight, per 100 parts by weight of the epoxy resin.
~3 parts by weight are used.

In addition, in the present invention, fillers and pigments such as silica, clay, gypsum, calcium carbonate, quartz powder, kaolin, mica, alumina, hydrated alumina, talc, dolomite, zircon, titanium compounds, molybdenum compounds, antimony compounds, Various conventionally known additives such as anti-aging agents and dispersants can be added.

〔Example〕

Hereinafter, the present invention will be specifically explained with reference to Examples. Note that parts in the examples indicate parts by weight.

Example 1 100 parts of bisphenol A epoxy resin with an epoxy equivalent of 170 to 180, N-methoxymethyl group pentavalent 6-nylon (however, methoxymethyl group substitution amount 30s + O1%) 2
0 part was dissolved in a mixing pot at 60 to 80°C for 5 hours, and after cooling to room temperature, 5 parts of dicyanfucimide, 3-(3,
3 parts of 4-dichlorophenyl)-1,1-dimethylurea was added and mixed for 2 hours at room temperature to obtain an epoxy resin composition.

Table 1 shows the properties of the cured product after heat curing at 160°C for 30 minutes.

Comparative Example 1 The same procedure as in Example 1 was carried out except that 20 parts of normal egg weight m6-nylon was used instead of the N-methoxymethyl group-substituted 6-nylon used in Example 1.

The results are shown in Table 1.

Comparative Example 2 Epoxy resin, dicyandiamide, 3-(3
,4-dichlorophenyl)-1,1-dimethylurea was dissolved and mixed for 2 hours at room temperature in a mixing pot to obtain an epoxy resin composition. Results first
Shown in the table.

Example 2 Bisphenol A of epoxy ff1950-1000
100 parts of type epoxy resin powder, N-methoxymethyl group-substituted 6-nylon (methoxymethyl group substitution number 30 mo1
%) powder, 50 parts of a phenolic compound powder consisting of a bisphenol A/epichlorohydrin condensate with an average molecular weight of 850, 0.3 parts of 2-methylimidazole, 30 parts of calcium carbonate, γ-glyndoxypropyltrimethoxysilane. 1 part of finely powdered silica were mixed in a triblend to obtain an epoxy resin composition. Table 1 shows the curing characteristics after heat curing at 180°C for 30 minutes.

Example 3 The same procedure as in Example 2 was carried out except that 2 parts of the N-methoxymethyl substituent 6-nylon of Example 2 was used.

The results are shown in Table 1.

Example 4 N-methoxymethyl substituent 6-nylon 15 of Example 2
The same procedure as in Example 2 was carried out except that 0 part was used. Results first
Shown in the table.

Comparative Example 3 The same procedure as in Example 2 was carried out except that the N-methoxymethyl group-substituted 6-nylon of Example 2 was not used. The results are shown in Table 1.

Comparative Example 4 The same procedure as in Example 2 was carried out except that only the N-methoxymethyl group-substituted 6-nylon powder of Example 2 was used. The results are shown in Table 1.

However, the measurement methods for each physical property in Table 1 are as follows.

0 Gel time: Measured on a hot plate at each curing temperature. 0 Tensile break adhesion: According to JIS-6850, force
Steel plate (SPCC-3D, 100×25
1.6 tffim) at 20°C.

OT peelable adhesive crab according to JIS-6854, steel plate (
Measured at 20°C using SPCC-3D, 100 x 25 x 0.8'm++).

0 elongation: hardened test piece <100XIOXItlI
I1)) tensile speed 0.5 arm/min, 20℃
Measured in.

〔Effect of the invention〕

As is clear from the above-mentioned Examples and Comparative Examples, the epoxy resin composition of the present invention makes it possible to obtain an epoxy resin composition that has both high shear adhesive strength and commercial and commercial/I release adhesive strength.

(that's all)

Claims (4)

[Claims] (1) An epoxy resin composition comprising an epoxy resin, a curing agent, and an alkoxymethyl group-substituted polyamide. (2) The epoxy resin composition according to claim 1, which contains 3 to 120 parts by weight of the polyamide resin per 100 parts by weight of the epoxy resin. (3) A patent claim in which the curing agent is at least one selected from dicyandiamide type, imidazole type, acid anhydride type, phenol type, acid hydrazide type, fluoroboron compound type, amine imide type, and tertiary amine type. Range 1
The epoxy resin composition according to item 1 or 2. (4) The epoxy resin composition according to any one of claims 1 to 3, further comprising a silane coupling agent.