JP2671528B2 - Instant adhesive composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Purpose of the Invention "Industrial field of application" The present invention relates to an instant adhesive composition containing 2-cyanoacrylic acid ester as a main component, and includes metal, plastic, rubber, It is intended to provide an instant adhesive composition having excellent fast curing property and adhesive strength in various materials such as ceramics and wood and having high water resistance.

Instant adhesives containing 2-cyanoacrylic acid ester as a main component have the property of being easily anionically polymerized by the adsorbed moisture on the surface of the adherend and rapidly curing, and thus have been widely used in various industrial fields, medical fields, It is used in the leisure field and even in ordinary households. The adhesive composition of the present invention can be widely used in these fields similarly to the conventional instant adhesives, and can be used for more applications because of its excellent water resistance.

"Prior Art" Various methods for increasing the adhesive water resistance of a 2-cyanoacrylic ester instant adhesive have been studied. As one of the methods, for 2-cyanoacrylic acid ester
A method of adding an amount of 1,1-disubstituted diene represented by the following general formula in an amount of more than 50% by weight and not more than 95% by weight (JP-B-62-62).
−28835) has been proposed.

(In the formula, R ₁ is hydrogen, an alkyl group having 1 to 5 carbon atoms, an aryl group, an aralkyl group, or halogen; R ₂ is hydrogen or an alkyl group having 1 to 5 carbon atoms;
Are the same or different and each is selected from a cyano group and a carboxylic acid ester group.) In addition, a method of adding a dicarboxylic acid or an α-ketocarboxylic acid to a 2-cyanoacrylic acid ester (Japanese Patent Publication No. 58-
18955, JP-B-58-30908), a method of adding dimethyl vinyl ethynyl carbinol / fluorinated ether (JP-B-SHO)
59-14510), and a method of introducing fluorine into the alkyl group of 2-cyanoacrylic acid ester (Japanese Patent Publication Nos. 47-25139 and 47-29488).

"Problems to be Solved by the Invention" Among the above methods, the method described in Japanese Patent Publication No. 62-28835 provides fairly good water resistance. However, since the amount of 1,1-disubstituted dienes such as 2-cyano-2,4-pentadienoic acid ester whose anionic polymerizability is much smaller than that of 2-cyanoacrylic acid ester is included, the adhesion rate is slow. is there. When the amount of stabilizer is reduced or a curing accelerator is added to obtain a sufficient adhesion rate, the storage stability of the composition is significantly reduced. Also,
When the 1,1-di-substituted diene unit is increased, the polarity of the cured product is lowered and the adhesiveness to metals is lowered.

On the other hand, methods other than the above cannot obtain practical water resistance. Since the polymer of 2-cyanoacrylic acid ester is a hydrolyzable polymer, it is considered that sufficient water resistance cannot be obtained only by adding a modifier or introducing fluorine into an alkyl group.

An object of the present invention is to solve such problems of the prior art, to provide an instant adhesive composition having excellent fast curing property, adhesive strength, and high water resistance.

(B) Structure of the Invention "Means for Solving Problems" The inventors of the present invention have conducted extensive studies to solve the above problems, and as a result, 2-cyano-acrylic acid ester has 2-cyano-
The present invention has been completed by finding that the above problems can be solved by using a combination of 2,4-pentadienoic acid ester, hydrophobic silica and a specific curing accelerator.

That is, the present invention relates to an instant adhesive composition comprising the following four components.

(1) 2-Cyanoacrylic acid ester (2) 2-Cyano-2,4-pentadienoic acid ester (3) Hydrophobic silica (4) Crown ether, polyalkylene oxide or derivative thereof In the instant adhesive composition of the present invention According to this, it is possible to provide an adhesive having excellent fast curing property and adhesive strength and having high water resistance.

○ 2-Cyanoacrylic Acid Ester The 2-cyanoacrylic acid ester used in the present invention includes all those normally used for instant adhesives.

Specific examples thereof include esters such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, pentyl, hexyl, cyclohexyl, 2-methoxyethyl and 2-ethoxyethyl.

2-Cyano-2,4-pentadienoic acid ester As the 2-cyano-2,4-pentadienoic acid ester used in the present invention, specifically, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec- Esters such as butyl, pentyl, hexyl, heptyl, octyl and cyclohexyl can be mentioned. As the ester group becomes larger, the rapid curing property, the adhesive strength, and the water resistance tend to decrease. Therefore, preferred for the present invention are methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl. Can be mentioned.

Hydrophobic silica The hydrophobic silica used in the present invention is a compound capable of reacting with a hydroxyl group existing on the surface of the hydrophilic silica in some form to form a hydrophobic group or adsorbed on the surface of the hydrophilic silica. A compound capable of forming a hydrophobic layer (hereinafter referred to as a surface treatment agent) and hydrophilic silica are brought into contact with each other in the presence or absence of a solvent, and preferably heated to change the surface of the hydrophilic silica to be hydrophobic. It is obtained by doing.

Examples of the hydrophilic silica as a raw material include fumed silica wet silica and the like, and the particle size of the primary particles is 1 to 100 μm.
m is preferable, and 5 to 50 μm is more preferable. As such a fine particle silica, for example, there is a highly dispersible amorphous silica obtained by hydrolyzing silicon tetrachloride in an oxyhydrogen flame. In addition, when hydrolyzed in an oxyhydrogen flame, titanium chloride, aluminum chloride, chlorides such as iron chloride coexist and alumina-containing silica, titanium oxide-containing silica, iron oxide-containing silica may be used in the present invention. Can be.

Examples of the surface treatment agent which changes the surface state of the hydrophilic silica into a hydrophobic silica include alkyl-, aryl-, and aralkyl-based silane coupling agents having a hydrophobic group such as n-octyltrialkoxysilane, dimethyldichlorosilane, and hexamethyldihexane. Examples thereof include silylating agents such as silazanes, silicone oils such as polydimethylsiloxane, higher alcohols such as stearyl alcohol, and higher fatty acids such as stearic acid.

As the hydrophobic silica in the present invention, a hydrophobic silica obtained by adding a dimethylsilyl group or a trimethylsilyl group to the surface of the hydrophilic silica, that is, a hydrophilic silica surface-treated with a so-called dimethylsilylating agent or trimethylsilylating agent Is preferably used.

Specific examples of the dimethyl silylating agent and the trimethyl silylating agent include dimethyldichlorosilane, dimethyldimethoxysilane, dimethyldiethoxysilane, dimethyldiacetoxysilane, in addition to hexamethyldisilazane,
Dimethylditrifluoroacetoxysilane, hexamethylcyclotrisilazane, trimethylchlorosilane, trimethylbromosilane, N, O-bis (trimethylsilyl) carbamate, N, N-diethylaminotrimethylsilane, N, N-dimethylaminotrimethylsilane, hexamethyldioxane , N-trimethylsilylimidazole, bis (trimethylsilyl) acetamide, bis (trimethylsilyl) trifluoroacetamide, bis (trimethylsilyl) urea, 2-trimethylsilokin-2-penten-4-one, trimethylsilylacetamide, trimethylsilyl-N, N'- Examples thereof include diphenylurea, 3-trimethylsilyl-2-oxazolidinone, and bis (trimethylsiloxy) dimethylsilane.

The hydrophobic silica used in the present invention can be obtained by the above-mentioned method, but it is possible to replace it with commercially available hydrophobic silica.

Commercially available hydrophobic silica includes AEROSIL R805 (Degussa) surface-treated with n-octyltrimethoxysilane.
AEROSIL R202 surface-treated with silicone oil)
(Manufactured by Degussa), AEROSIL R972, R974, R976 (all manufactured by Degussa) surface-treated with a dimethylsilylating agent,
AEROSIL R811, surface-treated with trimethylsilylating agent,
R812 (all manufactured by Degussa) and the like can be mentioned, which are 150 ± 20, 80 ± 20, 110 ± 20, 170 ± 2, respectively.
Specific surface area of 0, 250 ± 25, 150 ± 20, ²⁰⁰ ± 20 m ² / g, 50, 6
It is a hydrophobic fumed silica having a hydrophobicity of 5, 40, 35, 30, 60, 60. As another hydrophobic silica, there is Cab-O-Sil N70-TS (manufactured by CABOT), which is 100 ±
It has a specific surface area of 20 m ² / g and is reported to have been treated with an organosilicon compound.

○ Crown ether Crown ether is sometimes used as a general term for hetero macrocyclic compounds, but in the present invention, it means a macro cyclic polyether in which the hetero atom is only oxygen, specifically, 15-crown-5, 18-crown-6, dibenzo-18-crown-6, benzo-15-crown-5, dibenzo-24-crown-8, dibenzo-30-crown-1
0, tribenzo-18-crown-6, asym-dibenzo-2
2-crown-6, dibenzo-14-crown-4, dicyclohexyl-18-crown-6, dicyclohexyl-
24-crown-8, cyclohexyl-12-crown-
4,1,2-decalyl-15-crown-5,1,2-naphtho-
15-crown-5,3,4,5-naphthyl-16-crown-
5,1,2-methylbenzo-18-crown-6,1,2-methylbenzo-5,6-methylbenzo-18-crown-6,1,2
-Tert-butyl-18-crown-6,1,2-vinylbenzo-15-crown-5,1,2 vinylbenzo-18-crown-6,1,2-tert-butylcyclohexyl-18-crown-6, asym- Cibenzo-22-crown-6,1,2-benzo-1,4-benzo-5-oxygen-20-crown-
It is 7 mag.

○ Polyalkylene oxide Polyalkylene oxide is an alkylene oxide such as ethylene oxide, propylene oxide, butylene oxide, trimethylene oxide, tetramethylene oxide (tetrahydrofuran), 1,3-dioxolane, trioxane, and tetraoxane, and hydrogen of the alkylene group is halogen. 1 of compounds such as epichlorohydrin, epibromohydrin, glycidol, styrene oxide substituted with atoms, hydroxyl groups, phenyl groups, etc.
It means a polymer containing two or more species as a main component and also includes an aggregate containing a compound such as formaldehyde, acetaldehyde or glycerin as a main component.

The degree of polymerization of these polymers used in the present invention is 2
It is necessary to be above, preferably about 4 to 3000, but it is needless to say that depending on the case, a polymer having a degree of polymerization of up to 10,000 or more can be used. The molecular weight, which is related to the degree of polymerization, is 400 or more 1
It is preferably, 000,000 or less, more preferably 1,000 or more and 1,000 or less. A polymer having a degree of polymerization of 1 and a polymer having a small degree of polymerization (the same applies to the molecular weight) have a small effect of promoting set time, and it is difficult to obtain a composition having the performance targeted by the invention. Further, when the molecular weight is so high that the degree of polymerization far exceeds 10,000, the compatibility with 2-cyanoacrylate tends to decrease, and it is difficult to dissolve it in them to obtain a uniform composition. Become. Degree of polymerization is 2
In the above cases, the reason why it has the effect of promoting the set time is not clear, but it is presumed that the oxygen molecules in the chain-like polyalkylene oxide are arranged with the metal or the like.

In addition, the one in which the carbon number of the alkylene group is in the range of 2 to 6 is excellent in the effect of promoting the set time,
It is preferable for the present invention, and among them, ethylene, propylene, isopropylene, tetramethylene or a combination thereof is preferable, and propylene, tetramethylene or a combination thereof is particularly preferable.

Specific examples of the polyalkylene oxide used in the present invention include the following.

Diethyl glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, polypropylene glycol, poly 1,3-propylene glycol, polytrimethylene oxide, polytetramethylene oxide, polyepichlorohydrin, poly 3,3-bis (chloromethyl) Butylene oxide, polytetramethylene ether glycol, poly 1,3-dioxolane, poly 2,2
-Bis (chloromethyl) propylene oxide, ethylene oxide-propylene oxide block polymer, polyglycerin such as diglycerin, triglycerin and tetraglycerin, formaldehyde condensate, acetaldehyde condensate and trioxane polymer. In addition, various polyalkylene oxides commercially available as polyether-type urethane curing polyols can also be used in the present invention.

○ Polyalkylene oxide derivative The polyalkylene oxide derivative in the present invention is represented by an ester of the above polyalkylene oxide and an acid and an ether of a hydroxy group-containing compound, and those are preferable. Not particularly limited to, those having various substituents at the terminal of the molecule, those having other bonding parts inside the polyalkylene oxide, those having a polyalkylene oxide structure inside the molecule In that case, the intended effect of the present invention can be obtained. Examples of the acid that can form the ester include acetic acid, propionic acid, butyric acid, isobutyric acid, pivalic acid, pentanoic acid, n-hexanoic acid, 2-methyl-pentanoic acid, t-butylacetic acid, n-heptanoic acid, n-octanoic acid. Acid, n-decanoic acid, lauric acid, palmitic acid, stearic acid, oleic acid, cyclohexylcarboxylic acid, cyclopentylcarboxylic acid,
Cyclopropylcarboxylic acid, acrylic acid, methacrylic acid, maleic acid, itaconic acid, naphthenic acid, benzoic acid,
β-naphthylcarboxylic acid, p-toluenecarboxylic acid, furancarboxylic acid, p-chlorobenzoic acid, monochloroacetic acid, cyanoacetic acid, glycolic acid, lactic acid, phenyloxypropionic acid, succinic acid, glutaric acid, adibic acid, sebacic acid, Examples thereof include butanetetracarboxylic acid, aconitic acid, propane-1,2,3-tricarboxylic acid, citric acid, orthophthalic acid, isophthalic acid and trimellitic acid. As the hydroxy group-containing compound that can form ether, methinol, ethanol, propanol, isopropanol, butanol, isobutanol,
Hexanol, cyclohexanol, 2-ethyloctanol, decanol, lauryl alcohol, cesyl alcohol, stearyl alcohol, oleyl alcohol,
Phenol, α-naphthol, β-naphthol, cresol, t-butylphenol, octylphenol, nonylphenol, p-chlorophenol, resole, bisphenol A, 2-chloroethanol, ethylene cyanohydrin, trifluoroethanol, benzyl alcohol, 1,4 -Butanediol, 1,6-hexanediol,
Glycerin, sorbitol, hydrogenated bisphenol A,
Examples thereof include hydroxy group-containing compounds such as trimethylolpropane.

Specific examples of the ester or ether as the polyalkylene oxide derivative include diethylene glycol monoalkyl ether (eg, alkyl is methyl,
Ethyl, propyl, butyl, etc.) diethylene glycol dialkyl ether (where alkyl is, for example, methyl,
Ethyl, propyl, butyl, etc.), polyethylene glycol monoalkyl ether (eg, alkyl is methyl, ethyl, propyl, lauryl, cesyl, stearyl, oleyl, etc.), polypropylene glycol monoalkyl ether (eg, alkyl is methyl, ethyl, lauryl, etc.) Propyl, stearyl, cesyl, oleyl, perfluoroalkyl, etc.), polyethylene glycol monoaryl ether (as aryl, for example,
Octylphenyl, nonylphenyl, etc.), polyethylene glycol dialkyl ether, polyethylene glycol monoalkyl ester (eg, acetate, trifluoroacetate, laurate, stearate, oleate, methacrylate, etc.), polyethylene glycol diester, polypropylene glycol diester, bisphenol A -Polyalkylene oxide adduct (for example, ethylene, propylene, etc. as alkylene, the same applies hereinafter), hydrogenated bisphenol A-polyalkylene oxide adduct, trimethylolpropane-polyalkylene oxide adduct, glycerin-polyalkylene oxide adduct, polyoxyethylene. Sorbitan ester, tetraoleic acid-polyoxyethylene sorbit, adipi Acid-polyalkylene oxide adduct, trimellitic acid-polyalkylene oxide adduct, isocyanate compound-polyalkylene oxide adduct, phosphoric acid-polyalkylene oxide adduct, silicic acid-polyalkylene oxide adduct, (polyoxyalkylene) Examples include polysilanolates, (polyoxyalkylene) polyesters, (polyoxyalkylene) polyphosphates.

○ Other additives In addition to the above-mentioned components, the composition of the present invention contains various additives that are usually added to a 2-cyanoacrylate ester-based instant adhesive, such as an anionic polymerization inhibitor and a radical polymerization inhibitor. , Thickeners, plasticizers, dyes, pigments, fragrances and the like can be similarly added.

The anionic polymerization inhibitor is for preventing anionic polymerization due to water content in the composition, specifically, SO
₂ , SO ₃ , NO, NO ₂ , HCl, H ₃ PO ₄ , acidic phosphate ester,
Examples thereof include aromatic sulfonic acid, alkyl sulfonic acid, propane sultone, trifluoromethane sulfonic acid and perfluoroalkyl carboxylic acid. The preferred blending amount is 1
˜1000 ppm, more preferably 5 to 100 ppm.

The radical polymerization inhibitor is mainly added for the purpose of preventing radical polymerization or anaerobic polymerization caused by light hitting during storage, specifically, phenol, cresol, hydroquinone, hydroquinone monomethyl ether, catechol, Examples include pyrogallol. A preferred blending amount is 10 to 10,000 ppm, more preferably
It is 100 to 5000 ppm.

Although the thickener is added for the purpose of adjusting the viscosity of the adhesive, it also has the effect of improving the dispersion stability of the hydrophobic silica. Specific examples thereof include polymethyl methacrylate, polymethyl acrylate, polyvinyl acetate, cellulose ester and the like. The compounding amount is usually 1 to 10% by weight.

In addition, the same applies to carboxylic acids, dicarboxylic acids and their anhydrides and acrylic rubber, urethane rubber, and other elastomers used to improve impact adhesion strength and peel adhesion strength in 2-cyanoacrylic ester instant adhesives. Can be blended with.

○ Blending Ratio For the present invention, the blending ratio of 2-cyano-2,4-pentadienoic acid ester to 2-cyanoacrylic acid ester is
It is preferably 10% by weight or more and 50% by weight or less.
If it is less than 10% by weight, sufficient water resistance cannot be obtained, while
If it exceeds 50% by weight, it becomes difficult to obtain sufficient fast curing property and adhesive strength.

The preferable blending ratio of hydrophobic silica and crown ether, polyalkylene oxide or its derivative varies depending on the kind thereof and is not particularly limited, but generally 2-cyanoacrylic acid ester, 2-cyano-2,4 pentadienoic acid ester. Preferably for a mixture of
They are 1 to 30% by weight and 0.001 to 10% by weight, respectively. More preferably, 3 to 20% by weight and 0.003 to 1 respectively
% By weight. If the blending ratio of the hydrophobic silica is less than 1% by weight, sufficient water resistance and adhesive strength cannot be obtained, while
If it exceeds 30% by weight, the rapid curing property, the adhesive strength and the storage stability tend to decrease. In addition, the mixing ratio of crown ether, polyalkylene oxide or its derivative is 0.00
If the amount is less than 1% by weight, sufficient fast curing property and adhesive strength cannot be obtained. On the other hand, if the amount is more than 10% by weight, the rapid curing property does not increase so much, but the adhesive strength and storage stability tend to be remarkably reduced. is there.

"Action" The instant adhesive composition of the present invention has excellent fast-curing property and adhesive strength in the adhesion of various materials and, in addition, has a high degree of water resistance that cannot be considered by conventional instant adhesives. The present invention greatly expands the application of the instant adhesive.

Although the mechanism by which such an action is expressed is not clear, it is mainly due to the introduction of 2-cyano-2,4-pentadienoic acid ester into the polymer chain that the hydrolyzability is reduced and the hydrophobic silica is compounded. It is considered that the decrease in water absorption contributes to the development of high water resistance. But,
The water resistance is low when the proportion of 1,1-disubstituted dienes such as 2-cyano-2,4-pentadienoic acid ester is 50% by weight or less based on 2-cyanoacrylic acid ester.
28835, the onset of action as in the present invention is completely unexpected.

"Examples and Comparative Examples" Examples 1-14 14 compositions shown in Table 1 were prepared according to the present invention. In the table, the amounts of stabilizer, crown ether and others are 2-cyanoacrylic acid ester and 2-cyano-2,4-
The blending ratio is based on the mixture of pentadienoic acid ester, and the blending amounts of the thickener and the hydrophobic silica are wt%. Table 1 shows the results of measuring the set time of stainless steel in an atmosphere of 23 ° C./60% RH using this product. Also, 23 ℃ / 60% RH
The adhesive strength under normal conditions of the tensile shear test piece of stainless steel adhered under ambient atmosphere and the adhesive strength after being immersed in warm water at 50 ° C. for 168 hours were measured. The results are shown in Table 1, and in each case, high adhesive strength was obtained. Furthermore, when 3 g of the composition was filled in an aluminum tube and a stability test under heating at 60 ° C. was performed, it was confirmed that there was no change for 20 days or more and that the stability was practically sufficient. In addition, in order to make a more practical evaluation of water resistance, the composition of Example 1 was used to perform tensile shear adhesion between chrome platings, 180 ° peel adhesion between chrome plating and EPDM, and glass. EPD
Similar to stainless steel, a water resistance test was performed for 180 ° peel adhesion strength with M. The results are shown in Table 2, and all have good water resistance.

Comparative Example 1 The same test as in Example 1 was conducted using ethyl 2-cyanoacrylate, and the results are shown in Tables 2 and 3 above. The normal adhesive strength was good, but there was almost no water resistance.

Comparative Example 2 The same test as in Example 1 was conducted using a composition prepared by mixing ethyl 2-cyanoacrylate and methyl 2-cyano-2,4-pentadienoate in a ratio of 40/60. And shown in Table 3. The set time was slow, and the normal adhesive strength of various materials was low. The water resistance in the adhesion of stainless steel and chrome plating was quite good, but in the adhesion of chrome plating and EPDM and glass and EPDM, the normal adhesive strength was low and the water resistance was also low.

Comparative Examples 3 to 8 Six kinds of compositions other than the present invention were blended based on ethyl 2-cyanoacrylate and methyl 2-cyano-2,4-pentadienoate, and the same tests as in Examples 2 to 14 were conducted. I went. The results are shown in Table 3 above, but there was a problem in any of quick-curing property, normal-state adhesive strength, and water resistance, and the performance targeted by the present invention was not obtained.

(C) Effect of the Invention The instant adhesive composition of the present invention comprises metal, plastic,
The present invention provides an instant adhesive having excellent quick-curing property and adhesive strength in various materials such as rubber, ceramics, wood, etc., and having a high degree of water resistance. It is widely used in many applications and contributes greatly to adhesion in various industries, medical fields, leisure fields, and general households.

Claims (1)

(57) [Claims] 1. An instant adhesive composition comprising the following four components. (1) 2-Cyanoacrylic acid ester (2) 2-Cyano-2,4-pentadienoic acid ester (3) Hydrophobic silica (4) Crown ether, polyalkylene oxide or its derivative