JPH0222373A - Acrylic adhesive composition - Google Patents

Abstract

PURPOSE:To provide an acrylic adhesive composition composed of a specific ethylene-acrylate copolymer, an acrylic monomer and an organic peroxide and having high curing rate and adhesive strength. CONSTITUTION:The objective composition contains (A) a copolymer composed of ethylene, an alkyl(meth)acrylate and an alpha,beta-ethylenic unsaturated carboxylic acid (derivative), (B) a polymerizable acrylic monomer and (C) an organic peroxide. The amounts of the components A and B are 2-50 wt.% and 98-50 wt.% based on A+B, respectively, and the amount of the component C is 0.5-15 wt.% based on the sum of A, B and C.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an acrylic adhesive composition with excellent adhesive strength.

[Conventional technology]

Conventionally, curable resin compositions have been used in many fields, and adhesives are one of the main fields of use.

Typical examples include epoxy adhesives and acrylic polymer adhesives (1), which are known as adhesives that are liquid at room temperature and easy to work with.

However, many of these adhesives are not sufficient in terms of adhesive strength, particularly in terms of peelability, splitting, and impact strength, and improvements are desired.

[Problem to be solved by the invention]

The present invention was made to improve the above-mentioned situation, and its purpose is to provide a product that is significantly improved in terms of peelability, splitting, and impact strength compared to conventional products, and is a liquid with a fast curing speed at room temperature. An object of the present invention is to provide a fast acrylic adhesive composition.

[Means for solving cia] The acrylic adhesive composition of the present invention (hereinafter referred to as 1, composition) is a composition containing the following components A, B, and C, and the sum of A and B. A is 2-50% of the weight, B is 9%
8 to 50%, C is 0 to the total weight of A, B, and C.
．． It is characterized by being 5 to 15%.

A: Ethylene, alkyl (meth)acrylate, α, β
- A copolymer comprising an ethylenically unsaturated carboxylic acid or a derivative thereof.

B: Polymerizable acrylic monomer C: Organic supercatalyzed product The present invention will be explained in more detail below. Among the components constituting copolymer A, the alkyl (meth)acrylate preferably has an alkyl group of 1 to 6 carbon atoms,
Specific examples include the following.

Methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, butyl acrylate, butyl methacrylate, hexyl acrylate.

Moreover, among the components constituting copolymer A, the following can be exemplified as α,β-ethylenically unsaturated carboxylic acids or derivatives thereof.

Acrylic acid, methacrylic acid, crotonic acid, itaconic acid,
Unionized carboxylic acids such as maleic acid, fumaric acid, citraconic acid, methyl hydrogen maleate, methyl hydrogen fumarate,
Monoesters of dicarboxylic acids such as methyl hydrogen itaconate, acid anhydrides such as maleic anhydride, citraconic anhydride, itaconic anhydride, and fumaric anhydride.

In the present invention, as for the ratio of each component to copolymer A, ethylene ranges from 60 to 97.5 (weight i%,
(same below), preferably 69 to 94 inches. When the ratio of ethylene is less than 60%, the molecular weight of copolymer A becomes small, and when the composition of the present invention is used as an adhesive, the peel strength is particularly insufficient, and the molecular weight exceeds 97.51. This is not preferable because the solubility of copolymer A in polymerizable acrylic monomer B becomes insufficient.

In addition, the ratio of alkyl (meth)acrylate is 2 to 30
Unfortunately, it is preferably 5 to 25%. If the ratio of alkyl (meth)acrylate is less than 2%, the solubility of copolymer A in polymerizable acrylic monomer B will be insufficient;
If the molecular weight of the copolymer A exceeds 1, the molecular weight of the copolymer A becomes small, and especially when the composition of the present invention is used as an adhesive, the peel strength becomes small.

Furthermore, the ratio of α, β-ethylenically unsaturated carboxylic acid or its derivative is 0.5 to 10%, preferably 1%.
~6%. If the ratio is less than 0.5%, the adhesive strength will be insufficient when the composition of the present invention is used as an adhesive. Furthermore, if the ratio exceeds 10, disadvantages such as a low molecular weight of the copolymer and a low peel strength are inevitable.

Next, the polymerizable acrylic monomer B in the present invention is:
They are typified by acrylic acid, methacrylic acid, and esters derived from these. for example,
Acrylic acid, methacrylic acid, methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate,
Methyl methacrylate, ethyl methacrylate, butyl methacrylate, 2-ethylhexyl methacrylate, lauryl methacrylate, 2-hydroxyethyl methacrylate, 3-hydroxypropyl methacrylate, cyclohexyl methacrylate, glycidyl methacrylate, stearyl methacrylate, methoxypolyethylene glycol methacrylate, tetrahydrofurfuryl methacrylate, inbornyl methacrylate, benzyl methacrylate, 2-
Methacryloyloxyethylsuccinic acid, 2-methacryloyloxyethyl phthalic acid, 2-methacryloyloxyethylmaleic acid, 2-hydroxybutyl methacrylate, caprolactone methacrylate, ethylene glycol dimethacrylate, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, glycerine dimethacrylate methacrylate), 1,4-butanediol dimethacrylate, neopentyl glycol dimethacrylate, etc., but the present invention is not limited to these examples.

In addition, in the present invention, it is also possible to use two or more of the above-mentioned polymerizable acrylic monomers B in combination.

Next, the organic peroxide C in the present invention is used as a curing agent, and is typified by hydrono, monooxide, peroxy ester, and the like. Specific examples thereof include t-butylnodronoderoxide, cumene/)idoronodaroxide, p-menthano1hydro-oxide, 1-butylnohydro-oxy-P,
t-butyl no-oxybenzoate, t-butyl/
4'-oxyacetate, t-butyl A? -oxypivalate, etc., and 281 or more of these can also be used in combination in the present invention.

Each of the components A, B, and C in the present invention needs to satisfy the following weight ratio. First, A is 2 to 50% of the total weight of A and B, preferably 10 to 30%, and B is 98%.
~50%, preferably 90-70%. If component A is below the above range, it will not be possible to improve the peel strength, which is the objective of the invention, and if it exceeds the above range, problems will occur in terms of compatibility with component B.

In addition, the ratio of the C component to the total weight of the A-B s C components must be 0.5 to 15%, and 2 to 1%.
A range of 0 coefficient is preferable; when the C component is less than 0.5 flaws, the curing reaction of the composition becomes insufficient, and when it exceeds 15 flaws, the adhesive strength decreases.

The composition of the present invention can further improve performance such as impact strength by using various elastomers together.

In that case, the elastomer must have bath-dissolvable properties in the compositions of the invention; examples of such elastomers include chlorosulfonated polyethylene.

Examples include chlorinated polyethylene, chlorinated propylene, polybutadiene, polyisoprene, styrene-butadiene copolymer, acrylonitrile-butadiene copolymer, polychloroprene, I-urethane, and elastomeric saturated polyester.

The elastomer may be an oligomer or a polymer. Particularly in the case of the former, those having a functional group such as a hydroxyl group, a carboxyl group, an amino group, or a vinyl group at the terminal or side chain are preferred. The appropriate amount of elastomer to be blended is at most 50 inches based on the total weight of A, B, and C.

When bonding adherends together using the composition of the present invention,
The adherends can be bonded together by applying the composition to the surface of one adherend, bonding it to another adherend, and then heating. The heating temperature at this time is preferably in the range of 50 to 100°C.

Moreover, it is preferable that the composition of the present invention is used in combination with a curing accelerator using this as a main ingredient. When used together with a curing accelerator,
This is because it can be rapidly cured and bonded at room temperature.

As the curing accelerator, compounds that react with peroxides to generate radicals at room temperature and promote polymerization of the composition, such as organic amine compounds and metal soaps, can be used.

That is, the organic amine compounds mainly include diethylenetriamine, dimethylaniline, tetramethylmethaxylene diamine, a condensate of aniline and butyraldehyde, etc., and these may be used after being diluted with a solvent depending on the case.

In addition, metal soaps are mainly made of
Octoe acid co/? In some cases, these compounds can be diluted with a solvent or the above-mentioned component B and sealed.

The amount of the curing accelerator to be used varies depending on the composition* (main ingredient) used and cannot be determined unconditionally, but it is generally about 10 to 500 t to 'jILf of peroxide in the main ingredient. A thickener, a leveling agent, a titanium agent, etc. may be added to the main agent and curing accelerator.

When using a base agent and a curing accelerator together, you can mix them together, apply this mixture to the surface of the adherend, and immediately laminate them together for bonding. body r
IrJ, a curing accelerator is applied to the surface of the other adherend, and the fabric surfaces of both chambers are pasted together and rubbed lightly to mix the main ingredient with the curing accelerator, cause a curing reaction, and bond. You may.

The time required to achieve adhesion varies depending on the type of base agent and curing accelerator, but is generally 1 to 60 minutes.

Adherents to which the composition of the present invention can be bonded include metals such as iron, stainless steel, copper, aluminum, and zinc, glass, polystyrene, polycarbonate, ABS resin, surface oxidized ethylene, and surface oxidized polypropylene. , plastics such as area resins, phenolic resins, engineering resins, ceramics such as ceramic tiles, alumina sintered bodies, silica sintered bodies, and co-9
Examples include mu.

〔Example〕

Hereinafter, the present invention will be explained in more detail with reference to Examples and Comparative Examples.

Example 1 Copolymer consisting of 80% ethylene, 16% methyl methacrylate, and 4% maleic anhydride (number average molecule t12000
) 18 parts (by weight, same hereinafter), 40 parts of inbornyl methacrylate, and 1 part of chlorosulfonated polyethylene
2 parts, 10 parts of methacrylic acid, and 3 parts of trimethylolglopantrimethacrylate (!:, t-butyl g-
A composition was prepared by thoroughly mixing and dissolving 7 parts of oxybiparate.

An adhesion test on a steel plate was conducted using this composition as a main ingredient and a mixture of a condensate of aniline and butyraldehyde and tin octoate as a curing accelerator.

The laminating method was as follows: First, a base agent was applied to one side of a steel plate prepared according to JIS K 6850, a curing accelerator was applied to the other side of the steel plate, and both sides were laminated and lightly rubbed.

After leaving it at room temperature for 2 hours, the shear adhesive strength was measured at 30°C, and it was 175 to 9f/cm.
Met.

Further, a test piece of a steel plate was prepared according to JIS K 6854, and the peel strength of the steel plate bonded using the same method as the shear adhesive strength was measured, and it was found to be 11 kgf/25 m at 30°.

Comparative Example 1 A base resin was prepared in the same manner as in Example 1, except that the addition of the copolymer of ethylene, methyl methacrylate, and maleic anhydride in the base resin was omitted.

Thereafter, a steel plate adhesion test was conducted in the same manner as in Example 1.

Originally, the shear adhesive strength at 30℃ was 153k.
gf/cm2, peel strength is 5.8 klFf/25
In particular, the latter value was significantly inferior to that of Example 1.

Example 2 90% ethylene, 8% ethyl acrylate, 2% itaconic acid
Copolymer (number average molecular weight 34,000) consisting of 10
parts, 40 parts of 2-hydroxybutyl methacrylate,
18 parts of 2-methacryloyloxyethylsuccinic acid, 8 parts of neopentyl glycol dimethacrylate, 4 parts of trimethylolgulon triacrylate, and an acrylonitrile-butadiene copolymer oligomer (molecule [ 3500) 15 copies and -
A composition was prepared by thoroughly mixing and dissolving 5 parts of butyl nooxybenzoate. Using this composition as a main ingredient and the curing accelerator used in Example 1, the following adhesion test was conducted.

First, a base resin was applied to one side of an ABS resin board prepared according to K JIS K 6850 K as in Example 1, and AB
A curing accelerator was applied to the other side of the S resin plate, and both sides were pasted together and lightly rubbed. After standing at room temperature for 1 hour, the shear adhesive strength was measured at 30° C., and it was found that the bond strength was 130 kgf/z, and the material was completely destroyed.

In addition, ABS resin plate test pieces were prepared in accordance with JIS K 6855 and bonded using the same method as for the shear adhesive strength.
When the impact adhesive strength of the BS resin plate was measured, it was 8 kg f cm/2 at 30°C.

Comparative Example 2 A base resin was prepared in the same manner as in Example 2, except that the addition of the copolymer of ethylene, ethyl acrylate, and itaconic acid in the base resin was omitted.

Thereafter, an adhesion test for the ABS resin plate was conducted in the same manner as in Example 2.

As a result, the shear adhesive strength at 30℃ was 130kg.
f/1M, all materials were destroyed, but the impact adhesive strength was 5 II f cynics 2, which was inferior to Example 2.

Example 3 Copolymer consisting of 78% ethylene, 17% butyl acrylate, and 5% maleic anhydride (number average molecule f10200
) 40 parts and 2-hydroxybutylac')L/-)4
0 parts and 2-methacryloyloxyethylsuccinic acid io
A composition was prepared by thoroughly mixing and dissolving M, 3 parts of )+J methylolpronotane trimethacrylate, and 7 parts of t-butyl-oxypenzoate. Using this composition as a main ingredient and the curing accelerator used in Example 1,
The following adhesion test was conducted.

The bonding method was as follows: First, a base agent was applied to one side of an aluminum plate prepared according to JIS-K 6850, a curing accelerator was applied to the other side of the aluminum plate, and both sides were laminated and lightly rubbed.

After leaving it at room temperature for 2 hours, the shear adhesive strength was measured at 30°C and found to be 180 Yuf/IM. Also, test pieces of aluminum plate according to JIS K6854! ! When we measured the peel strength of an aluminum plate made of aluminum and bonded using the same method as the shear adhesive, it was found that the peel strength was 9 at 30℃.
．． It was 5 klFf/25 m.

〔Effect of the invention〕

The composition of the present invention is liquid at room temperature and has a fast curing speed.
Easy to work with. Moreover, adhesive strength, especially peelability,
It has excellent splitting and impact strength, and can be applied to a wide range of adhesives such as metals, ceramics, and plastics.

Claims (2)

[Claims] (1) Ethylene, alkyl (meth)acrylate and α,
An adhesive composition comprising a copolymer A made of a β-ethylenically unsaturated carboxylic acid or a derivative of the acid, a polymerizable acrylic monomer B, and an organic peroxide C, A is 2-50% and B is 98-50% of the total weight
, and C is 0.5 to 15 with respect to the total weight of A, B, and C.
%. (2) The weight ratio of the constituent components of the copolymer A is 60 to 97.5% ethylene and 2% alkyl (meth)acrylate.
30%, α,β-ethylenically unsaturated carboxylic acid or a derivative of said acid 0.5 to 10%
) The acrylic adhesive composition described in item 1.