JP2001164199A - Alpha-cyanoacrylate-based adhesive composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an α-cyanoacrylate-based adhesive composition especially excellent in fast curing properties in adhesion of hardly adhesive materials such as acrylics, chromium plating, nickel plating, polyesters (FRP), Bakelite, EPDM rubbers and the like or of porous materials such as papers, woods, leathers, ceramics and the like, as well as excellent in shelf stability. SOLUTION: The α-cyanoacrylate-based adhesive composition comprises 0.05-5.0 wt.%, based on α-cyanoacrylate, of 12-crown-4-ether having a pH of 10 wt.% diluted aqueous solution of 8.0 or lower.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an .alpha.-cyanoacrylate adhesive composition having excellent fast-curing properties and excellent storage stability. The adhesive composition of the present invention is acrylic, chrome-plated, nickel-plated, polyester
(FRP), bakelite, EPDM rubber and the like, which are particularly preferable for bonding difficult-to-bond materials and porous materials such as paper, wood, leather and ceramics.

[0002]

2. Description of the Related Art Since α-cyanoacrylate is extremely susceptible to anionic polymerization due to anionic active species such as moisture on the solid surface and air, alkali substances, etc., it is polymerized and cured in a short time without adding a catalyst or heating. Because of its properties, it is widely used as an instant adhesive for rubber, plastic, metal, glass and the like.

[0003] However, conventional α-cyanoacrylate-based adhesives include acryl, chromium plating, nickel plating, polyester (FRP), bakelite, EPDM rubber, etc., which are difficult to adhere to, and paper, wood, etc., which are porous materials.
In the bonding of adherends such as leather and ceramics, the quick-curing property is not sufficient, and improvement of the performance is strongly desired.

[0004] In order to solve these problems, Showa 50
Over 60 years, various compounds have been searched for as polymerization accelerators, and various additives such as polyethylene glycol derivatives, calixarenes, crown ethers and the like have been developed. For example, JP-A-54-28342 discloses a polyethylene glycol derivative and JP-A-60-179482.
Japanese Patent Application Laid-Open Publication No. HEI 7-125 discloses calixarenes. Japanese Patent Publication No. 55-2238 describes that crown ethers are effective as a curing accelerator for adhesion to paper and wood.

[0005] However, even when these additives are used, an instant adhesive having excellent fast curing properties and excellent storage stability has not been obtained. For example,
In the case where crown ethers (15-crown-5-ether, 18-crown-6-ether, dicyclohexyl-18-crown-6-ether) described in JP-B-55-2238 are used as additives. If the amount of addition is increased and the quick-curing property is increased, the storage stability is impaired, and it cannot be put to practical use. Conversely, if the added amount is reduced to an amount that does not impair the storage stability, there is a drawback that excellent fast curability cannot be obtained.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide acrylic, chromium plating, nickel plating, polyester (F)
Α-cyanoacrylate which has particularly excellent fast-curing properties in the adhesion of difficult-to-bond materials such as RP), bakelite and EPDM rubber and porous materials such as paper, wood, leather and ceramics, and at the same time has excellent storage stability. An object of the present invention is to provide a system-based adhesive composition.

[0007]

Means for Solving the Problems The inventors of the present invention have made intensive studies to solve the problems and found that a specific amount of 12-crown-4-ether in a specific pH range is added to α-cyanoacrylate. Due to this, it has particularly excellent fast-curing properties in bonding hard-to-bond materials such as acrylic, chrome-plated, nickel-plated, polyester (FRP), bakelite, and EPDM rubber and porous materials such as paper, wood, leather, and ceramics. At the same time, they found that an α-cyanoacrylate adhesive composition having excellent storage stability was obtained, and completed the present invention.

That is, the present invention relates to α-cyanoacrylate by adding 0.05% to 5.0% of 12-crown-4-ether having a pH of a 10% by weight aqueous solution of not more than 8.0.
The present invention relates to an α-cyanoacrylate adhesive composition characterized by containing 0% by weight.

Hereinafter, the present invention will be described in detail. As the α-cyanoacrylate used in the present invention, α-cyanoacrylate represented by the following one-way system is suitably used.

[0010]

Embedded image (Wherein R represents an optionally substituted hydrocarbon residue having 1 to 16 carbon atoms)

Specific examples of the compound include, for example, methyl, ethyl, n-propyl and i-cyanoacrylic acid.
Propyl, n-butyl, i-butyl, sec-butyl,
Esters such as octyl, neopentyl, cyclohexyl, ethylhexyl, dodecyl, allyl, methoxyethyl, ethoxyethyl, methoxypropyl, benzyl, phenyl, silyl, chloroethyl and the like can be mentioned. These α-cyanoacrylates can be used alone or in combination of two or more.

[0012] 12-crown-4- used in the present invention
Ethers are synthesized by known methods. A general synthesis method is described in JP-A-54-119483, and JP-B-59-119483.
27351, JP-B-59-519, JP-A-53-98985, Tetrahedron L
eters, Vol. 37, No14,2463-2
466 <1996> and the like.

The present inventors have found that there is a correlation between the pH of a 10% by weight aqueous solution of 12-crown-4-ether and the performance of the adhesive composition, and that the pH of the 12-crown-4 ether is 8.0 or less. -It has been found that excellent performance can be obtained by selectively using ether.

According to the above findings, in the present invention, 12
-P of 10% by weight aqueous solution of crown-4-ether
Select and use those having an H of 8.0 or less.
-7.5 are more preferred. If the pH exceeds 8.0, the storage stability of the α-cyanoacrylate will be remarkably deteriorated, and it will not be able to withstand practical use. The addition amount is 0.0
The range is preferably 5 to 5.0% by weight, and more preferably 0.1 to 3.0% by weight. If the amount is too small, the curing speed is insufficient, while if the amount is too large, the storage stability deteriorates.

The pH of the crown ether is measured by preparing a 10% by weight aqueous solution of crown ether diluted with distilled water having a pH of 7.0 to 7.5.
It is measured at 25 ° C. with a pH meter based on IS.

It is preferable to add an anionic polymerization inhibitor to the α-cyanoacrylate adhesive composition of the present invention. As the anionic polymerization inhibitor, specifically, sulfur dioxide, methanesulfonic acid, trifluoromethanesulfonic acid, p-toluenesulfonic acid, boron trifluoride diethyl ether, HBF ₄ , and trialkyl borate are preferably used. These compounds can be used alone or in combination of two or more depending on the purpose. The amount of the anionic polymerization inhibitor is preferably 0.1 to 100 ppm,
0.5 to 50 ppm is a more preferable range.

The α-cyanoacrylate adhesive composition of the present invention further comprises a radical polymerization inhibitor, if necessary. Examples of the radical polymerization inhibitor include hydroquinone, hydroquinone monomethyl ether, t-
Butyl catechol, catechol, pyrogallol and the like. The amount of the radical polymerization inhibitor added is usually 10 to 1
0000 ppm, preferably 50 to 5000 ppm.

The α-cyanoacrylate adhesive composition of the present invention may further comprise a plasticizer, a coloring agent, a fragrance, a solvent, an adhesive strength improver, a thickener, an inorganic filler, etc., depending on the application. The acrylate monomer can be appropriately added and blended within a range that does not inhibit the storage stability of the acrylate monomer.

Examples of the plasticizer include dimethyl phthalate, diethyl phthalate, dibutyl phthalate,
Examples thereof include 2-ethylhexyl phthalate, diisodecyl phthalate, trimethyl acetyl citrate, triethyl acetyl citrate, and tributyl acetyl citrate.

Examples of the thickener include various compounds known as thickeners for α-cyanoacrylate.
For example, polymethyl methacrylate (PMMA), acrylic rubber, polyester, polyvinyl chloride, polystyrene, cellulose ester, polyalkyl-α-cyanoacrylate, ethylene-vinyl acetate copolymer, and the like can be mentioned. These may be used in combination.

As the inorganic filler, hydrophobic silica, hydrophilic silica or the like can be added as a thixotropic agent.

[0022]

The α-cyanoacrylate-based adhesive composition of the present invention can be used for acrylic, chromium-plated, nickel-plated, polyester (FRP), bakelite, EPDM rubber, etc., for which improvement in quick-curing properties has been strongly demanded. It has excellent fast-curing properties and excellent storage stability for adherends such as porous materials such as paper, wood, leather, and ceramics, and also has excellent storage stability for general adherends. Also has very good fast-curing properties.

[0023]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples.

The measuring method in the examples was based on the following method. Set time (Evaluation of quick-curing property) Measurement was performed according to JIS K6838 using paper, ebony, Yonematsu, EPDM, and acrylic as adherends. (Unit: seconds) Storage stability 2 g of the prepared adhesive composition was filled in a poly bottle,
The number of days of gelation under an atmosphere of 95 ° C. and 95% RH was measured. pH Measurement A 10% by weight diluted aqueous solution of crown ether was prepared using distilled water having a pH of 7.0 to 7.5, and the pH was measured at 25 ° C. using a pH meter manufactured by Horiba, Ltd.

Examples 1-2 With respect to the ethyl-α-cyanoacrylate monomer, 10 ppm of HBF ₄ as an anionic polymerization inhibitor, 1500 ppm of hydroquinone as a radical polymerization inhibitor, and polymethyl methacrylate as a thickener (Sumitomo Chemical Industries, Ltd.) 5% by weight) and 12-crown-4-ether whose pH of a 10% by weight diluted aqueous solution is 8.0 or less is further added in the amount shown in Table 1 to obtain an adhesive composition. Was prepared. Table 1 shows the set time and storage stability of this adhesive composition.

Comparative Examples 1 to 5 Based on ethyl-α-cyanoacrylate monomer, 10 ppm of HBF ₄ as an anionic polymerization inhibitor, 1500 ppm of hydroquinone as a radical polymerization inhibitor, and polymethyl methacrylate as a thickener (Sumitomo Chemical Industries, Ltd.) 5% by weight), and the pH of a 10% by weight diluted aqueous solution is adjusted to 12-crown-4-ether (SIGMA reagent), 15-crown-5-ether (Tokyo Kasei reagent) described in Table 1. An adhesive composition was prepared by further adding 18-crown-6-ether (Tokyo Kasei Reagent) or calixarene (Aldrich Reagent) in the amounts shown in Table 1. Table 1 shows the set time and storage stability of this adhesive composition as comparative examples.

Examples 3 to 6 10 ppm of HBF ₄ as an anionic polymerization inhibitor and 1500 ppm and 1 ppm of hydroquinone as a radical polymerization inhibitor with respect to ethyl-α-cyanoacrylate monomer
12-crown-4-ether having a pH of 8.0 or less in a 0% by weight diluted aqueous solution was added in the amount shown in Table-2. Further, as an additive, 5% by weight of an acrylic rubber (Leocoat manufactured by Daiichi Race Co., Ltd.) in Example 4, 1.5% by weight of dibutyl phthalate in Example 5, and 0.1% by weight of pyrogallol in Example 6 were added. An adhesive composition was prepared. Table 1 shows the set time and storage stability of these adhesive compositions.
2 is shown.

Examples 7 to 10 For each of the following α-cyanoacrylate monomers, 10 ppm of HBF ₄ as an anionic polymerization inhibitor and 1,500 p of hydroquinone as a radical polymerization inhibitor were used.
pm and 5% by weight of polymethyl methacrylate (manufactured by Sumitomo Chemical Co., Ltd.) as a thickener and 12-crown-4-ether having a pH of a diluted aqueous solution of 10% by weight or less of pH 8.0 or less are listed in Table-3. Was added to prepare an adhesive composition.
Table 1 shows the set time and storage stability of this adhesive composition.
3 is shown. Example 7: methyl cyanoacrylate (indicated as MC in the table), Example 8: isopropyl cyanoacrylate (indicated as IPC in the table), Example 9: methoxyethyl cyanoacrylate (indicated as MEC in the table), practice Example 10: Ethoxyethyl cyanoacrylate (referred to as EEC in the table)

[0029]

[Table-1]

[0030]

[Table-2]

[0031]

[Table-3]

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Tsuki Wakatsuki 4-2-1, Nishi Mikuni, Yodogawa-ku, Osaka F-term in Taoka Chemical Industry Co., Ltd. (reference) 4J040 FA121 HA246 HB46 HD13 HD39 JA01 JB04 KA19 LA05 LA06 MA02 MA04 MA08 MA09 MA10 MA12 MA13

Claims (2)

[Claims] (1) A 10% by weight aqueous solution containing 0.05 to 5.0% by weight of 12-crown-4-ether having a pH of 8.0 or less based on α-cyanoacrylate. Α-cyanoacrylate adhesive composition. 2. An anionic polymerization inhibitor having a concentration of 0.1 to 100 pp.
The α-cyanoacrylate adhesive composition according to claim 1, wherein m is contained.