JPS6262875A - Adhesive composition - Google Patents

Abstract

PURPOSE:An adhesive, containing a specific polyfunctional polymerizable monomer, monofunctional polymerizable monomer, rubbery elastic polymer having the low second-order glass transition point, etc., in respective specific amounts, having high peeling strength and bonding strength in wetting and useful for bonding ceramic materials. CONSTITUTION:An adhesive composition consisting of (A) 0.1-20wt%, based on total polymerizable monomers, polyfunctional polymerizable monomer expressed by the formula (R1 is H or methyl; R2 is 6-20C alkylene), (B) 80-99.9wt%, based on the total polymerizable monomers, at least one monofunctional polymerizable monomer copolymerizable with the monomer (A), preferably (meth)acrylic acid ester based monomer, (C) 10-200pts.wt. based on 100pts.wt. total polymerizable monomers, rubbery elastic polymer preferably nitrile rubber or chlorosulfonated polyethylene, having <=10 deg.C send-order glass transition point and (D) 0.01-20pts.wt., based on 100pts.wt. total polymerizable monomers, polymerization initiator, preferably oxidation-reduction based initiator capable of initiating polymerization at room temperature.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an adhesive composition having excellent adhesive strength to metal materials, ceramic materials, polymeric materials, and the like. That is, the present adhesive composition is used as an adhesive for materials of the same or different types in the fields of transportation components such as automobiles and aircraft, electronic equipment, building materials, household use, and the like.

[Conventional technology]

Conventionally, adhesives used in the above-mentioned applications include, for example, sulfur-containing compositions selected from the group consisting of chlorosulfonated polyethylene and mixtures of sulfonyl chloride and chlorinated polyethylene, and (meth)acrylic monomers. and an initiator (Japanese Patent Publication No. 53-41
699); Also, an adhesive composition consisting of a butadiene-containing polymer elastomer, an acrylic monomer, an ethylenically unsaturated non-acrylic monomer, methacrylic acid, and a redox catalyst (Japanese Patent Publication No. 53-Z41O3); an acrylic acid alkyl ester and a diene Adhesive base composition consisting of a graft polymer obtained from a thread rubber polymer, a vinyl monomer, and a radical polymerization initiator (Japanese Patent Publication No. 58-34513)
)It has been known. However, for these adhesives, the effect of adding a polyfunctional polymerizable monomer that acts as a crosslinking agent has not been discussed, nor has a suitable composition been selected.

[Problem that the invention seeks to solve]

The above-mentioned Special Publication No. 53-24103, Special Publication No. 53-4169
The problem with the adhesive specifically disclosed in Japanese Patent Publication No. 58-34513g is that the peel strength in normal or wet conditions is low. Another problem is that the peel strength is low when heated at high temperatures.

Therefore, an object of the present invention is to obtain an adhesive composition that has high peel strength and high adhesive strength when wet.

[Means for solving problems]

In order to solve the above-mentioned problems, the present inventor conducted intensive studies and found that a specific amount of a specific polyfunctional polymerizable monomer represented by the general formula [1] described below was used in an adhesive, and By adding a specific proportion of a polymerizable monofunctional polymerizable monomer and further adding a rubber-like elastic polymer with a secondary glass transition point of 1O and below, an adhesive with high peel strength and high temperature and humidity resistance is created. The present invention was achieved based on the recognition that the following could be obtained.

That is, the present invention provides: A, a polyfunctional polymerizable monomer represented by the general formula [1] 0.1
~20% by weight (based on all polymerizable monomers) of 6 to 20 alkylene groups. ) B, 80 to 99.9% by weight (based on the total polymerizable monomers) of at least one yuzu monofunctional polymerizable monomer that can be copolymerized with the polyfunctional polymerizable monomer C, secondary glass transition Rubber-like elastic polymer with a point of 10°C or less 10 to 200 parts by weight (based on 100 parts by weight of all polymerizable monomers) D1 polymerization initiator 0.01 to 20 parts by weight (based on 100 parts by weight of all polymerizable monomers) ).

The polyfunctional polymerizable monomer represented by the general formula [1] used in the present invention includes 1,6-hexanethiol di(
Examples include meth)acrylate, 1.9-nonanediol di(meth)acrylate, and 1.12-dodecanediol di(meth)acrylate.

Usually, when the amount of the monomer having an alkylene group with n of 5 or less in the polyfunctional polymerizable monomer of the general formula (1) is increased, the heat resistance of the resulting adhesive is improved, but at the same time, the elasticity is also increased. However, when a monomer represented by the general formula [1] having a long-chain alkylene group with n of 6 or more is used as in the present invention, excellent heat resistance is maintained. However, since the elasticity does not increase, a decrease in peel strength can be prevented. However, when n is 20 or more, the resulting adhesive becomes brittle, which is not preferable. In other words, the presence of a long-chain alkylene group with n of 6 to 20 causes crosslinking, which not only increases the cohesive force but also imparts scorchability, which improves the peeling force under normal conditions, and also improves the peeling force when heated. Strength is also improved. It also has the effect of improving water resistance due to the hydrophobic action of long-chain alkylene.

In the present invention, a particularly preferred polyfunctional polymerizable monomer is a monomer having a linear alkylene group having 9 to 12 carbon atoms in R2 in the general formula (1).

Further, in the present invention, it is important that the polyfunctional polymerizable monomer is used in an amount of 0.1 to 20% by weight based on the total polymerizable monomers. When the amount added is less than 0.1% by weight, the effect is not expressed, and when the amount added is more than 20% by weight, the crosslink density of the cured product increases too much, resulting in loss of flexibility. Peel strength decreases. A particularly preferable addition amount is in the range of 2 to 15% by weight.

The monofunctional polymerizable monomer used in the present invention may be anything as long as it can be copolymerized with the above-mentioned polyfunctional polymerizable monomer.

The (meth)acrylic acid ester monomers described below are preferred, but monomers other than the (meth)acrylic acid ester monomers such as styrene, chlorostyrene, α-methylstyrene, acetic acid vinyl, ( Also used are meth)acrylic acid amide, maleic acid, maleic anhydride, fumaric acid, (meth)acrylonitrile, (meth)acrylic acid, and the like.

Such a monomer is usually used in combination with an esmyl (meth)acrylate monomer. The (meth)acrylic acid ester monomer preferably used in the present invention has 50 or less carbon atoms, and specifically, methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl-(meth)acrylate, etc. Acrylate, 1so-buty)v (meth)acrylate, n-hexyl-(meth)acrylate, 2-ethylhexy)V(meth)acrylate, Bendi/L/(meth)acrylate, Lauryl(meth)acrylate, Stearyl (meth)acrylate, 2-hydroxypropyl(meth)acrylate, dimethylaminoethyl(meth)acrylate, diethylaminoethyl(meth)acrylate, furfury)V(meth)acrylate, etc. .

It is necessary that these monofunctional polymerizable monomers be contained in the form of 80 to 99.9 fii based on the total polymerizable monomers. 8
Even if it is less than 0% by weight or more than 99.9% by weight, it is difficult to obtain excellent peel strength.The preferred content of the monofunctional polymerizable monomer is 85 to 98% by weight.

In the adhesive of the present invention, the monofunctional polymerizable monomer is copolymerized with the polyfunctional polymerizable monomer, and is blended or copolymerized with the rubber-like elastic polymer that is a component of the adhesive to harden the adhesive. plays an important role in properties, physical properties, and adhesive properties.

The rubber-like elastic polymer used in the present invention is not particularly limited as long as it has a secondary glass transition point of 100 C or less, but it is preferable that it is uniformly dissolved in the polymerizable monomer, and is generally unvulcanized. rubbery polymers are used. Preferably used rubber-like elastic polymers include:
Polyisoprene rubber (CR), polyisoprene rubber (B
R), acrylonitrile-butadiene rubber (NBR) (
= nitrile rubber), styrene butadiene rubber (SBR)
, polyisoprene rubber (IR), neoprene rubber, chlorosulfonated polyethylene (trade name: Hypalon, chlorine content 25-70% by weight, sulfonyl chloride moiety 3-1
60 mmol/100 g of polymer, melt index 4
~5UO), styrene-acrylonitrile rubber, polyacrylate rubber, polyvinyl alkyl ether, etc., and in particular, acrylonitrile-butadiene rubber and tolyl rubber) t7'v is preferably chlorosulfonated polyethylene.
L. Such a rubber-like elastic polymer has a total polymerizable monomer content of 10
It is used in an amount of 10 to 200 parts by weight per 0 parts by weight.

The presence of a rubber-like elastic polymer having a secondary glass transition point of 10° C. or less in the adhesive of the present invention is effective in improving the impact strength and peeling strength of the adhesive layer. If the amount of the rubber-like elastic polymer is less than 10 parts by weight (based on 100 parts by weight of the total polymerizable monomer), this effect will not be sufficiently expressed;
If the amount is more than 1 part by weight, the adhesive layer becomes too flexible and the tensile adhesive strength decreases on the contrary. In particular, in the adhesive of the present invention, due to the presence of specific amounts of the above-mentioned polyfunctional polymerizable monomer and rubber-like elastic polymer, it is possible to obtain a high peel strength that has not been previously obtained.

The polymerization initiator used in the present invention is a general term for all initiators that promote curing, including photosensitizers, and is 0.00% relative to the total polymerizable monomer. O1 to 20 parts by weight are used. The amount of this heavy initiator is 0.01
If it is less than 20% by weight, the polymerization reaction will not go well, and if it is more than 20% by weight, rapid heat generation will occur, and the nail hardware obtained under such conditions will be distorted and have poor physical properties. I don't like it. Among initiators, the method of adding a photosensitizer and curing by irradiating with ultraviolet or visible light, and the method of adding a redox catalyst and curing at around room temperature, can bond in a short time and are less affected by heating. It is also advantageous in terms of adhesion properties.

Examples of ultraviolet sensitizers include benzoins such as benzoin methyl ether and benzoin ethyl ether, benzyl diacetyl, α, β-naphthalene, α-diketones such as 2,3-pentadione, anthraquinone, and fenanthate V.
Quinones such as quinone, camphorquinone, and 2-methylanthoquinone; phenyl ketones such as acetophenone and benzophenone; and diphenyl disulfide;
Examples include di-β-naphthyl sulfide and dithiocarbamate.

Although some of the above-mentioned quinones and α-diketones can be cured alone as visible light sensitizers, curing is accelerated when used in combination with a reducing agent, which is advantageous as an adhesive.

In this case, it is necessary to separately hold the quinones or α-diketone and the reducing agent as the adhesive and divide the adhesive into two liquids.

It 7C agent is triethanolamine, N, N
-Tertiary amines such as dimethylaniline, thioureas such as allyl thiourea, thiourea such as J, 0-) IJ 1,000 urea, benzenesulfinic acid sotaya toluenesulfinate sodium and aromatic sulfinates are preferred. It is mentioned as.

Redox catalysts that can be cured in a relatively short time at room temperature include hydrogen peroxide/Fe2' ring system, cumene hydroperoquine)'/p62'?salt!, benzoyl peroxide/N, N- Dialkylaniline derivative system, ascorbic acid/CuzJ system, organic sulfinic acid (or its salt)/
Amine/peroxide system, bency peroxide lv/cobalt naphthenate, hydroperoxide/tertiary amine/sulfonyl chloride, peroxide/thiourea derivative, peroxide/thiourea derivative/organic acid copper salt, peroxide Oxide/aldehyde-amine condensate, cumene hydroperoxide/N
, N-dimethylaniline/cobalt naphthenate/sodium benzenesphinate, but are not limited thereto.

When the above-mentioned initiator is composed of an oxidizing agent and a reducing agent, it is desirable to keep the oxidizing agent and the reducing agent separately and use a two-component type.

In addition to the above-mentioned constituent components, a volatile organic solvent may be added to the #: adhesive of the present invention, if necessary. Addition of a volatile organic solvent is advantageous in order to improve wetting of the adhesive to the adherend and to increase the solubility of the polymer or polymerization initiator. Further, in order to improve the storage stability of the adhesive and adjust the curing time, a polymerization inhibitor, antioxidant, etc. can be added as necessary.

〔Effect of the invention〕

The adhesive of the present invention has excellent adhesion to various metal materials (iron, stainless steel, aluminum, copper, zinc, tin, brass, etc.), ceramics, and glass materials. In particular, it has excellent peel strength and adhesive strength when wet. Therefore, the adhesive of the present invention can be applied to transportation parts and equipment such as automobiles and aircraft, electronic equipment,
Useful as an adhesive in building materials, ceramics and household applications. It is also used as an undercoat material and coating material for paints and paints. Especially under high humidity atmosphere or (
・Q when used in environments where there are many opportunities to come into contact with fresh water.
The adhesion strength is shown in f.

〔Example〕

The present invention will be explained in more detail with reference to Examples. The treatment of adherends, the adhesion method, the tensile shear test, and the T-peel test were conducted as follows.

Treatment of adherend: After sanding with #240 sandpaper, degreasing was performed with acetone.

Adhesion method: After applying the adhesive to the adherend, pressing was performed using a spacer so that the adhesive layer had a thickness of 200 μm. The pressure bonding was carried out at 25°C for 15 minutes, and the sample after bonding was cured for one day (25°C) and the adhesive strength was measured.

Tensile shear test: the adherend is 1.6 t for metal
pm thickness. Measurement of tensile shear strength is JISK685
0. When wet, the test piece (cold rolled M) was immersed in warm water at 70°C for 10 days and then returned to room temperature for measurement.

T-peel test: The adherend is 0.5m thick and JISK
Measurement was performed according to 6854.

Example 1 and Comparative Examples Adhesives having various compositions as shown in Table 1 below were prepared. Table 2 shows the measurement results of adhesive strength.

Below is a blank Table 2: Measurement results of various adhesive strengths Note: The adherend was a JIS G314t cold rolled steel plate. Excellent strength, and
It can be seen that it is also extremely resistant to hot water. That is, as shown in Comparative Examples 1-A and ]-H, when ethylene glycol dimethacrylate was used as the polyfunctional polymerizable monolayer, the peel strength was low, and the heat resistance and rime properties were also poor.

Example 2 and Comparative Example 2 Adhesives like those shown in Table 3 below? Made by A.

The adhesion test results are shown in Table 4.

Note) The adherend is JIS G3141 cold-rolled steel plate. As is clear, there is a long-chain alkyl-containing polyfunctional polymerizable monomer, which is the special mold of the adhesive of the present invention. Otherwise, the dynamic shear strength will decrease significantly, and the addition of 20
It can be seen that when the weight exceeds % (total polymerizable monomer), the peel strength decreases significantly.

Example 3 The results of adhesion tests on various adherends are shown in Table 7. 69, and also shows that it has excellent adhesive strength to non-metallic materials such as plastic and glass.

Patent applicant RiRashi Co., Ltd. Acting Patent Attorney Ken Honda

Claims (1)

[Claims] (1) A, 0.1 to 20% by weight of a polyfunctional polymerizable monomer represented by the general formula [1] (based on the total polymerizable monomers) ▲ Numerical formulas, chemical formulas, tables, etc. Yes▼[1] (R_1 is hydrogen or methyl group, R_2 has 6 to 2 carbon atoms
0 alkylene group. ) B. 80 to 99.9% by weight of at least one monofunctional polymerizable monomer copolymerizable with the polyfunctional polymerizable monomer (based on the total polymerizable monomers) C. Secondary glass transition point 10 to 200 parts by weight of a rubber-like elastic polymer having a temperature of 10°C or less (based on 100 parts by weight of all polymerizable monomers) D. 0.01 to 20 parts by weight of a polymerization initiator (based on 100 parts by weight of all polymerizable monomers) An adhesive composition consisting of: (2) The adhesive composition according to claim 1, wherein the rubbery elastic polymer having a secondary glass transition point of 10° C. or lower is nitrile rubber or chlorosulfonated polyethylene. (3) The adhesive composition according to claim 1 or 2, wherein at least one monofunctional polymerizable monomer is a (meth)acrylic acid ester monomer. (4) Claims 1, 2, or 3, wherein the polymerization initiator is a photosensitizer that can be activated by irradiation with ultraviolet rays or visible light to initiate polymerization. adhesive composition. (5) The adhesive composition according to claim 1, 2, or 3, wherein the polymerization initiator is an oxidation-reduction initiator that can initiate polymerization at room temperature. (6) The adhesive composition according to claim 5, wherein the oxidizing agent and the reducing agent in the oxidation-reduction initiator are held separately and are at least two-part.