JP2839348B2 - Acrylic adhesive composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a two-part acrylic adhesive composition.

[Prior art] The demand for an acrylic adhesive that cures in a short time at room temperature is
It tends to increase year by year from the viewpoint of labor saving, resource saving and energy saving. Conventionally, there are instantaneous adhesives, anaerobic adhesives, two-component acrylic adhesives, etc., which are well known as room-temperature fast-curing acrylic adhesives.

Among these adhesives, the instant adhesive has excellent workability, but generally has low peel strength and impact strength, and is inferior in heat resistance and moisture resistance, so that its use range is extremely limited.

In addition, since the anaerobic adhesive is an adhesive which is cured by pressing the adhesive between the adherends to be bonded and blocking the air, the anaerobic adhesive is exposed to air such as a portion which sticks out from between the adherends when pressed. The adhesive in contact with is not cured. Therefore, when the porous adherend and the clearance between the adherends are large, the adhesive is not sufficiently cured, and poor adhesion is likely to occur.

The two-component acrylic adhesive is generally called a second-generation acrylic adhesive (SGA). Although it is a two-component adhesive, it does not require accurate measurement of the two components, and is extremely rough. It has excellent workability of curing at room temperature for several minutes to tens of minutes at room temperature at the time of only two liquid contact, and also has high peel strength,
It has been widely used because it has an impact strength and also has a good hardening of the exposed portion. However, from the viewpoints of labor saving, resource saving, and energy saving, there is an increasing demand for shortening the curing time of such a two-part acrylic adhesive from several minutes to several tens minutes at ordinary temperature.

Adhesives that cure quickly have been developed to meet such demands. For example, the adhesive disclosed in U.S. Pat. No. 4,348,503 comprises a urethane acrylate, an acrylate monomer, an aromatic perester, an organic acid and a transition metal, and cures with a set time of 45 seconds.
Further, the adhesive disclosed in JP-A-60-199085,
It comprises a specific urethane acrylate, a (meth) acrylate (herein referred to as an acrylate and a methacrylate), a monomer, a peroxyester and a compound forming a redox system with the peroxyester. It consists of an accelerator and is also cured with a fast set time of less than one minute. In addition, JP
The adhesive composition described in -65277 is composed of chlorosulfonated polyethylene, a specific acrylic monomer, cumene hydroperoxide, an aldehyde-amine condensate, and an oxidizing organic compound of a transition metal, and has a content of 5 to 10 seconds. It is disclosed that the resin cures in a curing time of. However, these adhesives are not sufficiently adherent to adherends such as aluminum, stainless steel, and chromate plating, and the range of use is limited.

On the other hand, conventionally, an example in which an acidic phosphorus compound is blended with an acrylic adhesive has been known. For example, it is disclosed that an acidic phosphoric acid compound is used to increase the adhesiveness of an acrylic adhesive to aluminum, stainless steel, chromate plating, etc., but all have fast curing properties sufficient to meet the demand. (JP-A-51-132234, JP-A-58-147477, U.S. Pat. No. 4,731,146).

JP-A-62-177006 discloses a fast-curing, two-pack type photocurable composition, and describes an acidic phosphoric acid ester monomer as an acrylic compound that can be used. However, U.S. Pat.
The specification describes that an acidic phosphoric acid compound slows down the curing rate when it is incorporated into an acrylic adhesive.

Further, an example in which an organic sulfonyl chloride compound is blended with an adhesive containing a polymerizable vinyl monomer and a polymerization catalyst is disclosed in
JP-132119, JP-A-51-7040, JP-A-56-28
No. 259 is disclosed. In these prior arts, the sulfonyl chloride group is said to improve the adhesive performance by improving the curing speed and graft polymerizing the (meth) acrylate monomer starting from the sulfonyl chloride group. An adhesive having both fast curing properties and good adhesion cannot be obtained.

[Problems to be Solved by the Invention] An object of the present invention is to provide a two-pack type acrylic adhesive composition which is fast-curing and excellent in adhesion.

Means for Solving the Problems The inventors of the present invention have conducted intensive studies in view of such a conventional technique, and as a result, by blending a specific compound, a two-liquid composition having a fast curing property and excellent adhesion. It has been found that a type of acrylic adhesive can be obtained, and the present invention has been completed.

That is, the present invention provides a first liquid containing: a) an acrylic compound selected from (meth) acrylic acid and its ester; b) a polymerization initiator selected from peroxyester; c) an organic sulfonyl chloride compound having 1 to 20 carbon atoms. And d) a reaction condensate of an amine and an aldehyde; e) a second liquid containing a copper salt, wherein at least the first liquid of the first liquid and the second liquid contains an acidic phosphorus compound represented by the following general formula (I): An acrylic adhesive composition comprising an acid compound.

Wherein R is an alkyl group, an alkoxyalkyl group or a CH ₂ CRCR ₁ —CO (OR ₂ ) _m — group (where R ₁ is H or C
H _3, R ₂ is _{-C 2 H 4 -, - C} 3 H 6 -, −C ₄ H ₈ −, −C ₆ H ₁₂ − or And m is an integer of 1 to 10. ), And n is 1 or 2. Hereinafter, the present invention will be described in detail.

The acrylic compound selected from (a) component (meth) acrylic acid and its ester used in the first liquid of the acrylic adhesive composition of the present invention may be any compound as long as it is capable of radical polymerization. The following is shown.

A monomer represented by the general formula AOR ₃ .

Wherein A is a (meth) acryloyl group, CH ₂ CHCHCOOCH ₂
—CH (OH) CH ₂ —, or CH ₂ ＣC (CH ₃ ) COOCH ₂ —CH
(OH) CH ₂ —, wherein R ₃ is H, an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group, a benzyl group, a phenyl group, a tetrahydrofurfuryl group, a glycidyl group, a dicyclopentanyl group, a dicyclo Represents a pentenyl group or a (meth) acryloyl group.

Such monomers include, for example, (meth) acrylic acid,
Methyl (meth) acrylate, cyclohexyl (meth) acrylate, benzyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, dicyclopentanyl (meth) acrylate, dicyclopentenyl (meth) acrylate, glycerol (Meth) acrylate, glycerol di (meth) acrylate and the like.

General formula A monomer represented by

In the formula, A and R ₃ are as described above. R ₄ is -C ₂ H ₄
−, −C ₃ H ₆ −, —C ₄ H ₈ — or —C ₆ H ₁₂ —, and p represents 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, phenoxyethyl (meth) acrylate, Cyclopentenyloxyethyl (meth) acrylate, phenoxydiethylene glycol (meth) acrylate, tripropylene glycol di (meth) acrylate, 1,6-
Hexanediol di (meth) acrylate and the like.

General formula A monomer represented by

In the formula, A and R ₄ are as described above. R ₅ represents H or an alkyl group having 1 to 4 carbon atoms, and q represents an integer of 0 to 8.

Such monomers include, for example, 2,2-bis (4-
Methacryloxyphenyl) propane, 2,2-bis (4-
Methacryloxyethoxyphenyl) propane, 2,2-bis (4-methacryloxydiethoxyphenyl) propane, 2,2-bis (4-methacryloxypropoxyphenyl) propane, 2,2-bis (4-methacryloxytetraethoxy) Phenyl) propane and the like.

(Meth) acrylic acid esters of polyhydric alcohols not included in the monomers described in the above and.

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

A urethane prepolymer having a (meth) acryloyloxy group.

Such a monomer can be obtained, for example, by reacting a (meth) acrylate having a hydroxyl group with an organic polyisocyanate and a polyhydric alcohol.
Here, examples of the (meth) acrylate having a hydroxyl group include hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, and hydroxybutyl (meth) acrylate. 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.

As described above, the monomers described above can be used alone or in combination of two or more.
Desirably, at least one of the monomers constituting the component a is a urethane prepolymer having a (meth) acryloyloxy group.

Examples of the polymerization initiator selected from the peroxyesters of the component b used in the present invention include, for example, tertiary butyl peroxybenzoate, tertiary butyl peroxyacetate, tertiary butyl peroxyisobutyrate, tertiary butyl peroxyphthalate, and the like. Among them, tertiary butyl peroxybenzoate is most preferable among the peroxyesters.

Although the components a and b contained in the first liquid have been described,
The preferred blending ratio is 0.1 to 10 parts by weight, particularly preferably 1 to 7 parts by weight, for the component b with respect to 100 parts by weight of the component a.

The organic sulfonyl chloride compound having 1 to 20 carbon atoms used as the component c in the present invention is represented by the formula R ₆ (SO ₂ Cl) _x (where x is an integer of 1 to 5, and R ₆ is an alkyl group having 1 to 20 carbon atoms or an aryl group having 1 to 20 carbon atoms, and R ₆ may contain an oxygen or nitrogen atom.) Examples of this organic sulfonyl chloride compound include methanesulfonyl chloride, ethanesulfonyl chloride,
Alkylsulfonyl chlorides such as 1-butanesulfonyl chloride, benzenesulfonyl chloride, p-toluenesulfonyl chloride, 2-naphthalenesulfonyl chloride, 4,4'-chloride
Arylsulfonyl chlorides such as biphenyldisulfonyl and the like can be mentioned, and two or more of these can be used in combination.

The amount of the organic sulfonyl chloride compound having 1 to 20 carbon atoms of the component c is determined based on the concentration of the sulfonyl chloride group (—SO ₂ Cl) per 100 g of the acrylic compound selected from the component (meth) acrylic acid and its ester. It is preferable to add so that it becomes 0.2 to 6 mmol. The amount added is 0.
If it is less than 2 mmol, the effect of accelerating the curing speed is weak, and
If the amount exceeds 6 mmol, both the adhesive strength and the storage stability of the adhesive decrease.

Further, a photopolymerization initiator can be added to the first liquid. As the photopolymerization initiator, any one can be used without particular limitation, for example, benzyl,
Benzophenone, benzoin ethyl ether, benzyl dimethyl ketal and the like can be mentioned, and it is also possible to use a combination of two or more of these.

The addition amount of the photopolymerization initiator is 0.05 to 7 parts by weight, particularly preferably 0.5 to 5 parts by weight, based on 100 parts by weight of the component a in the first liquid.

Next, the d component and the e component constituting the second liquid will be described.

The reaction condensate of the amine and aldehyde of the d component used in the present invention is, for example, an amine 1 in the presence of an organic acid such as acetic acid or propionic acid or an inorganic acid such as phosphoric acid or sulfuric acid.
At least 1 mole, preferably 1.5 to 3 moles
And those obtained by reacting a mole of aldehyde at 40-70 ° C. Examples of the amine used to obtain the condensate include primary aliphatic amines such as ethylamine, propylamine and butylamine, and primary aromatic amines such as aniline and naphthylamine.
Examples of the aldehyde include aliphatic aldehydes such as formaldehyde, acetaldehyde and propionaldehyde.

The copper salt of the component e is an organic or inorganic salt, and examples thereof include copper acetate, copper naphthenate, copper octenoate, and copper acetylacetone complex.

In order to obtain a second liquid containing the e component and the d component, the method of dissolving or diluting in these volatile organic solvents and using them can uniformly mix the d component and the e component. Also excellent in nature. Examples of the volatile organic solvent include methylene chloride, trichloroethane, acetone, methyl ethyl ketone, ethyl acetate, toluene, methanol, ethanol, and the like. The volatile organic solvent may be used alone or in combination of two or more. Can be.

It is desirable that the concentration of the component d in the second liquid is 1% by weight or more, preferably 10% by weight or more.

The amount of component e is 10% by the concentration of copper itself in the second liquid.
〜10000 ppm, preferably 50-1000 ppm.

The acrylic adhesive composition of the present invention is a two-part acrylic adhesive composition comprising a first liquid and a second liquid, and at least the first liquid of the first liquid and the second liquid has the following general formula: The acidic phosphoric acid compound represented by (I) is contained.

Wherein R is an alkyl group, an alkoxyalkyl group or a CH ₂ CRCR ₁ —CO (OR ₂ ) _m — group (where R ₁ is H or C
H _3, R ₂ is _{-C 2 H 4 -, - C} 3 H 6 -, −C ₄ H ₈ −, −C ₆ H ₁₂ − or And m is an integer of 1 to 10. ), And n is 1 or 2. Examples of the acidic phosphoric acid compound represented by the general formula (I) include butyl acid phosphate, 2-ethylhexyl acid phosphate, butoxyethyl acid phosphate, acid phosphooxyethyl (meth) acrylate, and acid phosphooxypropyl. Examples thereof include (meth) acrylate and bis (2- (meth) acryloyloxyethyl) phosphate. These acidic phosphoric acid compounds can be used alone or in combination of two or more.

The acidic phosphoric acid compound needs to be contained in the first liquid, and may be contained in both the first liquid and the second liquid.

When the acidic phosphoric acid compound is blended only in the first liquid, it is preferably 0.05 to 10 parts by weight, particularly preferably 0.5 to 7 parts by weight, based on 100 parts by weight of the component a in the first liquid. When the compound is mixed in both the first liquid and the second liquid, 0.05 to 10 parts by weight, particularly 0.5 to 7 parts by weight of the first liquid is added to 100 parts by weight of the component a in the first liquid. It is preferable that the concentration of the compound in the second liquid is 0.05
It is preferable that the compounding is performed so as to be 10 to 10% by weight, particularly 0.5 to 7% by weight.

Various additives can be contained in the adhesive composition of the present invention as needed. Fine powder silica, fine powder hydrophobic silica, etc. can be added for adjusting the viscosity and fluidity.

In addition, the acrylic adhesive composition of the present invention can be photocured by adding a photopolymerization initiator to the first liquid and applying ultraviolet rays to the protruding portion, as described above. Paraffin or the like can also be added to the first liquid for curing the protruding portion that cannot be exposed to ultraviolet light.

Further, various polymerization inhibitors for the purpose of improving storage stability,
It is also possible to add additives such as antioxidants.
In addition, various epoxy compounds, plasticizers, fillers, coloring agents, and the like can be added as a stabilizer for the sulfonyl chloride group, if desired.

The acrylic adhesive composition of the present invention cures quickly and in a short time by contacting the first liquid and the second liquid.

When using the acrylic adhesive composition of the present invention, since the curing speed is high, the first liquid is applied to one adherend, the second liquid is applied to the other adherend, and the second liquid is applied. In the case where a volatile solvent is contained, it is desirable to volatilize the volatile solvent and then bond the adhered surfaces of the adherends together. If a protruding part or the like where the first liquid and the second liquid are not contacted by this method occurs, a photopolymerization initiator is added to the first liquid as necessary, and the protruding part is irradiated with ultraviolet light. Can be cured.

Examples Hereinafter, the acrylic adhesive composition of the present invention will be further described with reference to examples.

Examples 1-4 and Comparative Examples 1-3 The component a, component b, component c and the acidic phosphoric acid compound
The first liquid was mixed by the mixing amounts shown in the table.

Further, the d component, the e component, and the solvent were mixed in the amounts shown in Table 1 to obtain a second liquid.

The fixing times of Examples 1 to 4 and Comparative Examples 1 to 3 were measured by the following method using the first liquid and the second liquid of each example, and are shown in Table 1.

Measurement method of fixation time Two iron test specimens for measuring the shear strength described below were used, one of which was coated with the first liquid, and the other was coated with the second liquid. After the solvent was volatilized, the application surfaces of the adherends were put together, and a time required until a load of 4 kg could not be removed by applying a load of 4 kg was defined as a fixing time.

Example 5 and Comparative Example 4 Component a, component b, component c and the acidic phosphoric acid compound
The first liquid was mixed by mixing the amounts shown in the table.

Further, the d component, the e component, and the solvent were mixed at the compounding amounts shown in Table 2 to obtain a second liquid.

Using the first liquid and the second liquid of each example, the fixing time of Example 5 and Comparative Example 4 and the tensile shear strength were measured by the following method, and the results are shown in Table 2.

Measurement method of tensile shear strength According to ASTM D-1002, iron (SPCC, 100 × 25 ×
1.6 mm, acetone degreased), aluminum (A-505
2. Using 100x25x2mm, acetone degreased) or stainless steel (SUS304, 100x25x1.6, acetone degreased), glue each with a superposition length of 12.5mm, and after curing for 24 hours, Instron 1123 Type tensile tester (tensile speed 10
mm / min).

Example 6 and Comparative Example 5 To 100 parts by weight of the first liquid obtained in Example 5, 1 part by weight of benzyldimethyl ketal as a photopolymerization initiator was added and mixed and dissolved to prepare a first liquid. The second liquid obtained in Example 5 was applied to one surface of one of two iron test pieces for tensile shear strength measurement so as not to protrude, and the first liquid was applied to one surface of another test piece. Was adhered so that the application surfaces of the adherends were matched with each other and the first liquid protruded. When the adhesive is exposed to ultraviolet light (TOSQUA 400, manufactured by Toshiba Corporation, lamp output 80 W / cm, irradiation distance 15 cm) for 10 seconds, the exposed part is cured, and the surface of the cured product is touched with a finger. Even tack was completely gone.

When the same test piece was not irradiated with ultraviolet light, the protruding portion remained tacky on the surface after one day or remained uncured.

[Effect of the Invention] The adhesive composition of the present invention has an extremely fast curing rate at room temperature and has excellent adhesion to a wide range of adherends including metals and chromate-treated surfaces, so that the production line can be shortened and streamlined. And the industrial benefits are extremely large.

Claims (2)

(57) [Claims] 1. A first liquid containing: a) an acrylic compound selected from (meth) acrylic acid and its ester; b) a polymerization initiator selected from peroxyester; c) an organic sulfonyl chloride compound having 1 to 20 carbon atoms. And d) a reaction condensate of an amine and an aldehyde; e) a second liquid containing a copper salt, wherein at least the first liquid of the first liquid and the second liquid contains an acidic phosphorus compound represented by the following general formula (I): An acrylic adhesive composition comprising an acid compound. [Wherein, R represents an alkyl group, an alkoxyalkyl group, or a CH ₂ CRCR ₁ —CO (OR ₂ ) _m — group (where R ₁ is H or CH ₃ ,
R ₂ is _{-C 2 H 4 -, - C} 3 H 6 -, −C ₄ H ₈ −, −C ₆ H ₁₂ − or And m is an integer of 1 to 10. ), And n is 1 or 2. ] 2. The acrylic adhesive composition according to claim 1, wherein the first liquid contains a photopolymerization initiator.