JPH0987590A - Adhesive composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an adhesive compsn. which contains a polymerizable vinyl monomer, cures in a short time, and adheres to an adhered with a high peeling strength. SOLUTION: Water in an amt. of 0.02wt.% is incorporated into an adhesive compsn. contg. a polymerizable vinyl monomer, an org. peroxide, a reducing agent. and (meth)acrylic acid. The vinyl monomer is a polymerizable (meth) acrylic acid deriv. The compsn. is of a two-pack type. comprising the first pack and the second pack. The peroxide is contained in the first pack, and the reducing agent, in the second pack.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an adhesive composition containing a polymerizable vinyl monomer. Specifically, it relates to an adhesive composition in which the polymerizable vinyl monomer is a polymerizable (meth) acrylic acid derivative.

[0002]

2. Description of the Related Art The demand for room-temperature fast-curing adhesives that cure at room temperature in a short time tends to increase year by year because of labor saving, resource saving, energy saving and the like. Conventionally, as a room temperature fast-curing adhesive, a two-component fast-curing epoxy adhesive, an anaerobic adhesive, an instant adhesive, and a second-generation acrylic adhesive (SG
A) is known.

[0003] The two-pack type fast-curing epoxy-based adhesive measures and mixes a main agent and a curing agent, applies the mixture to an adherend, and cures by a reaction between the main agent and the curing agent. However, the two-component fast-curing epoxy adhesive may cause a significant decrease in strength when the main component and the curing agent are not sufficiently measured and mixed, and
Even when the weighing and mixing are sufficiently performed, there is a disadvantage that the peel strength and the impact strength are low.

The anaerobic adhesive is cured by pressing the adhesive composition between adherends to block air.
However, when a part of the adhesive composition comes out of the adherend during the pressure bonding, there is a disadvantage that the come-off part does not cure because it comes into contact with air. Further, there is a drawback that it does not cure even when the clearance between adherends is large.

Instant adhesives usually contain cyanoacrylate as a main component and are excellent in workability. However, there was a drawback that peel strength and impact strength were low. In addition, there is a disadvantage that the range of use is extremely limited due to poor moisture resistance and water resistance.

Although SGA is a two-part type, it does not require accurate metering of the two parts, and even incomplete metering or mixing (sometimes only contact between the two parts) cures at room temperature in minutes or tens of minutes. For,
Excellent workability. Moreover, SGA has been widely used because of its high peeling strength and impact strength, and the good hardening of the humped portion. However, such an SGA is disclosed in, for example, Japanese Patent Application Laid-Open No. 49-132119 and Japanese Patent Application Laid-Open No. 53-254.
Although disclosed in Japanese Patent Laid-Open No. 3 etc., there is a drawback that the adhesiveness to the adherend is not sufficient.

In order to solve these drawbacks, Japanese Patent Laid-Open No.
Japanese Patent Publication No. 179204 discloses that the adhesiveness of an adhesive composition is improved by adding water to the adhesive composition containing a polymerizable vinyl monomer.

[0008]

In recent years, it has been required to improve the productivity of the bonded body of adherends using the adhesive composition. Therefore, an adhesive composition having a shorter fixing time than ever has been required. However, in order to shorten the fixing time, it is necessary to change the amounts of the main components of the adhesive composition such as the polymerizable vinyl monomer, the organic peroxide and the reducing agent, in which case the original SGA There is a problem that the characteristic peel strength is reduced.

The present invention has been made in order to solve these problems, and an object thereof is to provide an adhesive composition which has a short fixing time and a high peel strength with respect to an adherend. And As a result of intensive studies, the present inventors have obtained the finding that an adhesive composition containing water and (meth) acrylic acid achieves this object, and completed the present invention. .

[0010]

Means for Solving the Problems That is, the present invention provides an adhesive composition containing (1) a polymerizable vinyl monomer, (2) an organic peroxide, (3) a reducing agent, and (4) (meth) acrylic acid. Yes, 0.02-5% by weight
It is an adhesive composition characterized by containing the water of. Further, the adhesive composition is a two-component adhesive composition comprising a first liquid and a second liquid, wherein the first liquid contains an organic peroxide and the second liquid contains a reducing agent. Which is a two-component adhesive composition.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below.
The polymerizable vinyl monomer (1) used in the present invention may be any as long as it is radically polymerizable. Above all, it is more preferable that the polymerizable vinyl monomer is a polymerizable (meth) acrylic acid derivative from the viewpoint of the curing speed and the like. The polymerizable (meth) acrylic acid derivative is preferably 70 parts by weight or more in 100 parts by weight of the polymerizable vinyl monomer, and it is more preferable that all the polymerizable vinyl monomers are the polymerizable (meth) acrylic acid derivative.

Here, the polymerizable (meth) acrylic acid derivative means a polymerizable acrylic acid derivative and / or a polymerizable methacrylic acid derivative. These are usually used in liquid or solid form. Examples of the polymerizable (meth) acrylic acid derivative include the following.

General formula Z-O-R₁ The monomer shown by. In the formula, Z is (meth) acryloyl
Group, ch₂= CHCOOCH₂−CH (OH) CH₂-Group or CH ₂ = C (CH_Three)
COOCH₂−CH (OH) CH₂Represents a group, R₁Is a carbon number of 1 to 20
Alkyl group, cycloalkyl group, benzyl group, phenyl
Group, tetrahydrofurfuryl group, glycidyl group, disic
Ropentyl group, dicyclopentenyl group or (meth) ac
Indicates a liloyl group.

Examples of such a monomer include methyl (meth) acrylate, cyclohexyl (meth) acrylate, benzyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, and dicyclopentyl (meth) acrylate. , Dicyclopentenyl (meth) acrylate,
Examples thereof include glycerol (meth) acrylate and glycerol di (meth) acrylate.

A monomer represented by the general formula Z—O— (R ₂ O) _p —R ₁ . In the formula, Z and R ₁ are as described above. R ₂ is _{-C 2 H 4 -, - C} 3 H 6 -, - CH 2 CH (CH 3) -, - C 4 H 8
- or -C ₆ H ₁₂ - indicates, p is an integer of 1 to 25.

Examples of such a monomer include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, ethoxyethyl (meth) acrylate, polyethylene glycol (meth) acrylate and phenoxyethyl (meth). Acrylate,
Examples thereof include dicyclopentenyloxyethyl (meth) acrylate, phenoxydiethylene glycol (meth) acrylate, tripropylene glycol di (meth) acrylate, and 1,6-hexanediol di (meth) acrylate.

General formula

Embedded image The monomer shown by. In the formula, Z and R ₂ are as described above. R ₃ represents hydrogen or an alkyl group having 1 to 4 carbon atoms, q
Represents an integer of 0 to 8.

Examples of such a monomer include 2,2
-Bis (4- (meth) acryloxyphenyl) propane, 2,2-bis (4- (meth) acryloxyethoxyphenyl) propane, 2,2-bis (4- (meth) acryloxydiethoxyphenyl) propane 2,2-bis (4- (meth) acryloxypropoxyphenyl) propane, 2,2-bis (4- (meth) acryloxytetraethoxyphenyl) propane, and the like.

A (meth) acrylic acid ester of a polyhydric alcohol which is not contained in the above-mentioned or monomer.

Examples of such a monomer include trimethylolpropane tri (meth) acrylate, neopentyl glycol di (meth) acrylate, pentaerythritol tetra (meth) acrylate and dipentaerythritol hexa (meth) acrylate. To be

A urethane prepolymer having a (meth) acryloyloxy group. Such a monomer can be obtained, for example, by reacting a (meth) acrylic acid ester having a hydroxyl group, an organic polyisocyanate and a polyhydric alcohol.

Examples of the (meth) acrylic acid ester having a hydroxyl group include hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate and the like.

Examples of the organic polyisocyanate include toluene diisocyanate, 4,4-diphenylmethane diisocyanate, hexamethylene diisocyanate and isophorone diisocyanate.

Examples of the polyhydric alcohol include polyethylene glycol, polypropylene glycol, polytetramethylene glycol, polyester polyol and the like.

An acidic phosphoric acid compound represented by the following general formula (I):

Embedded image Wherein, R _{CH 2 = CR 4 CO (OR} 5) m - group (wherein, R ₄ is hydrogen or methyl, R ₅ is _{-C 2 H 4 -, - C} 3 H 6 -, - CH 2 CH (CH ₃ )
−, −C ₄ H ₈ −, −C ₆ H ₁₂ − or

Embedded image And m represents an integer of 1 to 10. ), And n is 1
Or an integer of 2.

Examples of the acidic phosphoric acid compound represented by the general formula (I) include acid phosphooxyethyl (meth) acrylate, acid phosphooxypropyl (meth) acrylate or bis (2- (meth) acryloyloxyethyl) phosphine. Examples include fate. that's all,
The monomer of ,,, or may be used alone or in combination of two or more.

Examples of the polymerizable vinyl monomer other than the polymerizable (meth) acrylic acid derivative include styrene and α
-Alkylstyrene, divinylbenzene, vinyl ether, divinyl ether, N-vinylpyrrolidone, 2-vinylpyridine, or vinyl ester such as vinyl acetate or vinyl propionate.

Further, a polymerizable substance other than the polymerizable vinyl monomer can be used in combination with the adhesive composition of the present invention. Examples of the substance include maleic acid having a polymerizable unsaturated bond, maleic anhydride, fumaric acid, itaconic acid,
Polycarboxylic acids such as itaconic anhydride or citraconic acid,
Examples thereof include monocarboxylic acids such as crotonic acid and isocrotonic acid, and polymerizable olefinic hydrocarbons having 6 or more carbon atoms.

When a polymerizable substance other than the polymerizable vinyl monomer is used, the amount of the substance used depends on the curing rate and the like.
It is preferably less than 30 parts by weight in 100 parts by weight of the polymerizable vinyl monomer used. One or more of these can be used.

The organic peroxide (2) used in the present invention is, for example, cumene hydroperoxide, paramenthane hydroperoxide, tertiary butyl hydroperoxide, diisopropylbenzene dihydroperoxide, methyl ethyl ketone peroxide, benzoyl peroxide. Examples thereof include oxide or tertiary butyl peroxybenzoate. Among them, cumene hydroperoxide is preferred from the viewpoint of reactivity.

The amount of the organic peroxide used is preferably 0.1 to 20 parts by weight with respect to 100 parts by weight of the polymerizable vinyl monomer. If the amount is less than 0.1 parts by weight, the curing rate is slow, and if it exceeds 20 parts by weight, the storage stability may be deteriorated.

The reducing agent (3) used in the present invention may be any known reducing agent that reacts with the organic peroxide to generate radicals. As a typical reducing agent, for example,
Examples thereof include tertiary amines, thiourea derivatives and metal salts.

Examples of the tertiary amine include triethylamine, tripropylamine, tributylamine, N, N-dimethylparatoluidine and the like. Examples of the thiourea derivative include 2-mercaptobenzimidazole, methylthiourea, cibutylthiourea, tetramethylthiourea, ethylenethiourea and the like.
Examples of the metal salt include cobalt naphthenate, copper naphthenate, vanadyl acetylacetone, and the like.

The amount of the reducing agent used is the polymerizable vinyl monomer 1
0.05 to 15 parts by weight is preferable with respect to 00 parts by weight.
If the amount is less than 0.05 parts by weight, the curing rate will be slow, and if it exceeds 20 parts by weight, unreacted reducing agent will remain and the adhesive strength may decrease.

The (4) (meth) acrylic acid used in the present invention means acrylic acid and / or methacrylic acid, and has effects of shortening the curing rate and improving the adhesive strength.
In particular, it has the effect of increasing the adhesive strength of the adherend covered with the metal and the corrosion-resistant metal oxide film.

The amount of (meth) acrylic acid used is preferably 0.5 to 20 parts by weight with respect to 100 parts by weight of the polymerizable vinyl monomer. When the amount of (meth) acrylic acid is less than 0.5 parts by weight, the effect of increasing the curing speed and the adhesive strength is small,
On the other hand, if the amount exceeds 20 parts by weight, the adhesive strength is rather lowered, and especially the alkali resistance may be reduced. Among (meth) acrylic acid, methacrylic acid is preferable from the viewpoint of safety.

The adhesive composition of the present invention preferably contains 0.02 to 5% by weight of water in the adhesive composition,
It is more preferable to contain 0.25 to 4% by weight. If the concentration of water is less than 0.02% by weight, the effect of improving the adhesiveness is small, and if it exceeds 5% by weight, the effect of improving the adhesiveness is not observed and water may be separated.

Water used in the present invention is not particularly limited,
For example, water that is usually obtained, or distilled water, ion-exchanged water, degassed water, or purified water such as water obtained by microfiltration of these is available. Further, water containing a polymer substance such as polyvinylpyrrolidone, polyethylene oxide, alkyl celluloses or polyvinyl alcohol, or water containing a surfactant may be used. Further, water in the state of water-based synthetic resin emulsion or rubber latex may be used.

The content concentration of water is adjusted so that the concentration of water in the adhesive composition used in the present invention is 0.02 to 5% by weight. When the adhesive composition is a two-component type, the content concentration of water is adjusted so that the concentration of water in the liquid obtained by mixing the first liquid and the second liquid is 0.02 to 5% by weight.

Any amount of water can be added to the adhesive composition to contain a predetermined amount of water. However, a method of adjusting the amount of water by adding or dehydrating water to the adhesive composition is used. It is common. In addition, a predetermined amount of water may be contained in advance in a substance to be used such as a polymerizable vinyl monomer, an organic peroxide or a reducing agent. A known stirrer, a line mixer, a mixing type applicator, or the like can be used to uniformly contain water.

In the present invention, an elastomer component may be used in the adhesive composition in order to improve the peel strength and impact strength. As the elastomer component, for example, those which can be dissolved or dispersed in the polymerizable vinyl monomer are preferable, and those which can be dissolved or dispersed in the polymerizable (meth) acrylic acid derivative are more preferable.

Examples of such an elastomer component include various synthetic rubbers such as acrylonitrile-butadiene rubber, styrene-butadiene rubber, chloroprene rubber and butadiene rubber, and natural rubber.
Among these, acrylonitrile-butadiene rubber is preferred from the viewpoint of solubility and adhesion to the polymerizable vinyl monomer. These elastomer components can be used alone or in combination of two or more as long as they have good compatibility.

The amount of the elastomer component of the present invention used is preferably 5 to 40 parts by weight with respect to 100 parts by weight of the polymerizable vinyl monomer. If it is less than 5 parts by weight, the viscosity and the adhesiveness may be lowered, and if it exceeds 40 parts by weight, the viscosity may be too high and work may be inconvenient.

In addition to this, for the purpose of adjusting viscosity and fluidity, methyl methacrylate-butadiene-styrene copolymer (MB
S), chlorosulfonated polyethylene, polyurethane, styrene-acrylonitrile copolymer, acrylonitrile-styrene-butadiene copolymer, thermoplastic polymer such as polymethylmethacrylate or linear polyurethane, or fine powder silica should also be used. You can

Further, the adhesive composition of the present invention may use various paraffins in order to accelerate the curing of the portion in contact with air. Examples of paraffins include
Paraffin, microcrystalline wax, carnauba wax, beeswax, lanolin, spermaceti, ceresin or candelilla wax and the like can be mentioned. Of these, paraffin is preferred. The melting point of paraffins is preferably 40 to 100 ° C.

The amount of paraffins used is preferably 0.1 to 5 parts by weight with respect to 100 parts by weight of the polymerizable vinyl monomer. If the amount is less than 0.1 part by weight, curing of the portion in contact with the air may be deteriorated, and if it exceeds 5 parts by weight, the adhesive strength may be reduced.

Further, various antioxidants including a polymerization inhibitor can be used for the purpose of improving storage stability. Examples of the antioxidant include hydroquinone, hydroquinone monomethyl ether, 2,6-ditertiarybutyl-p-cresol, 2,2′-methylenebis (4-methyl-6-tertiarybutylphenol),
Triphenyl phosphite, phenothiazine, N-isopropyl-N'-phenyl-p-phenylenediamine and the like can be mentioned. Among these, hydroquinone monomethyl ether is preferable.

The amount of the antioxidant used is preferably 0.001 to 3 parts by weight with respect to 100 parts by weight of the polymerizable vinyl monomer. If the amount is less than 0.001 part by weight, there is no effect, and if it exceeds 3 parts by weight, the curing strength may be reduced. In addition to these, if desired, a plasticizer, a filler,
It is also possible to use already known substances such as colorants or rust inhibitors.

As an embodiment of the present invention, use as a two-pack type adhesive composition can be mentioned. For the two-part type, do not mix during storage of all the essential components of the adhesive composition of the present invention, the adhesive composition is divided into a first liquid and a second liquid, the organic peroxide in the first liquid, The reducing agent is stored separately in the second liquid. The two-pack type is preferable because it is excellent in storage stability. In this case, contact both by applying both solutions simultaneously or separately,
By curing, it can be used as a two-component adhesive composition.

In another embodiment, either or both of the first liquid and the second liquid are preliminarily mixed with a polymerizable vinyl monomer, (meth) acrylic acid, water and other optional components, and both are mixed at the time of curing. Can be used as a one-pack type adhesive composition.

In the present invention, the adherend is bonded or coated with the cured body of the adhesive composition to form a composite. Regarding various materials of the adherend, there is no limitation such as paper, wood, ceramics, glass, ceramics, rubber, plastic, mortar, concrete or metal, but when the adherend is a metal, it shows an excellent adhesive effect, The best adhesion effect is obtained when the body is made of steel.

[0052]

The present invention will be described in more detail with reference to the following examples. In addition, hereinafter, the unit of the amount of each substance used is shown in parts by weight. The following abbreviations were used for each substance. Abbreviation N-220SH: Acrylonitrile-butadiene rubber (Nippon Synthetic Rubber Co., Ltd.) MMA: Methyl methacrylate 2HEMA: 2-Hydroxyethyl methacrylate P-56: Paraffin (mp 56 ° C) CHP: Cumene hydroperoxide MEHQ: Hydroquinone Monomethyl ether ETU: Ethylenethiourea MA: Methacrylic acid

Various physical properties were measured as follows. [Moisture Concentration] The moisture concentration of the adhesive composition was measured by using a trace moisture measuring device CA-03 type (Mitsubishi Kasei Co., Ltd.).

[Fixing Time] According to JIS K-6850 tensile shear strength test method, iron test pieces (SPCC, 100
× 25 × 1.6 mmt, bonding surface sand blasting) were laminated (lapped length 12.5 mm) to measure the tensile shear strength, and the time from the bonding to the breaking load of 4 kgf was measured as the fixing time.

[Peeling Strength and Destruction State] JIS K-6
According to 854, one test piece (200 × 25 × 1.2 m
m, SPCC-D untreated) with the first liquid applied to one side,
If there is a second liquid, another test piece (200 x 25
The second liquid was applied to one surface of (0.4 mm × untreated SPCC-D). Immediately thereafter, the coated surfaces were overlaid and bonded together, and then aged at room temperature for 24 hours to obtain a peel strength measurement sample. In addition, in order to make the thickness of the adhesive composition layer uniform, a small amount of glass beads having a particle diameter of 100 μm was added. The peel strength (unit: kg / 25 mm) of the sample is 100 mm / tensile speed under the environment of temperature 23 ° C and humidity 50%.
Measured in minutes. Regarding peel strength, good reproducibility was shown in the case of cohesive failure, but poor reproducibility in the case of interfacial peeling.

(Example 1 and Comparative Example 1) Each of the substances except for cumene hydroperoxide and water (ion-exchanged water) were mixed in the amounts shown in Table 1 to prepare a liquid having a composition having a water content shown in Table 1. did. Then, cumene hydroperoxide was mixed and immediately adhered, and the fixing time and the peel strength were measured. The results are also shown in Table 1.

[0057]

[Table 1]

(Examples 2 to 7 and Comparative Examples 2 to 5) Moistures shown in Tables 2 and 3 by mixing each substance and water (ion-exchanged water) in the amounts used in Tables 2 and 3 An adhesive composition consisting of a first liquid and a second liquid having a concentration was prepared, and the fixing time and the peel strength were measured. The results are also shown in Tables 2 and 3.

[0059]

[Table 2]

[0060]

[Table 3]

(Comparative Example 6) A test was conducted in the same manner as in Example 1 except that maleic acid was used instead of methacrylic acid in the amounts shown in Table 4. The results are shown in Table 4.

[0062]

[Table 4]

[0063]

By the adhesive composition of the present invention, a bonded body having a short fixing time and a high peeling strength with respect to an adherend can be obtained. In particular, by shortening the fixing time, the productivity of the bonded body of the adherends can be improved, and its industrial advantage is extremely large.

Claims (6)

[Claims] 1. An adhesive composition containing (1) a polymerizable vinyl monomer, (2) an organic peroxide, (3) a reducing agent, and (4) (meth) acrylic acid, said adhesive composition. An adhesive composition characterized in that it contains 0.02 to 5% by weight of water. 2. The polymerizable vinyl monomer is polymerizable (meth).
The adhesive composition according to claim 1, which is an acrylic acid derivative. 3. The two-component adhesive composition according to claim 1 or 2, wherein the adhesive composition comprises a first liquid and a second liquid, and the first liquid contains an organic peroxide. A two-pack type adhesive composition, wherein the two-pack contains a reducing agent. 4. A cured product of the adhesive composition according to claim 1, claim 2, or claim 3. 5. A composite body coated or bonded with the cured body according to claim 4. 6. The bonded body according to claim 5 or 6, wherein the adherend is a metal.