JPS6018561A - Primer composition for α-cyanoacrylate adhesive - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a primer composition for α-cyanoacrylate adhesives.

α-Cyanoacrylate adhesives generally have the following formula: This adhesive is an anionic polymerizable adhesive whose main component is a cyanoacrylate monomer represented by an oxy group or an allyloxy group. It has excellent adhesive properties and is widely used in various industrial fields and in general households.

However, such α-7 anoacrylate adhesives
When applied to adherends with porous surfaces such as cloth, leather, and wood, the adhesive soaks into the adherend, making it impossible to bond effectively, and since it is an anionic polymerization type, On acidic surfaces such as wood, the curing speed is slow and the essential purpose of instant adhesion cannot be achieved.

Conventionally, various measures have been taken to eliminate the above-mentioned drawbacks when bonding adherends with such porous or acidic surfaces, that is, adherends with difficult-to-adhesive surfaces, using α-cyanoacrylate adhesives. A proposal was made. The most effective measure is to pre-treat the adhesive surface with a primer. Conventionally, primers used for this purpose have been prepared by dissolving or dispersing various inorganic and organic compounds listed below in water, methanol, ethanol, acetone, etc.

(1) Basic metal hydroxides such as sodium hydroxide and potassium hydroxide (2) Basic salts such as sodium acetate, potassium carbonate, and sodium borate (3) Metal oxides such as zinc oxide and magnesium oxide (2) Inorganic salts such as calcium chloride and sodium chloride (3) Amines such as lower fatty amines, lower alkanolamines, aromatic amines, and alicyclic amines (2) Formamide, acetamide, Acid amides such as dimethylacetamide and malonamide (7) Nitrogen-containing heterocompounds such as piperidine, pyridine, and mole 7-olin (7) Sodium halam dodecylbenzenesulfonate, polyoxyethylene lauryl (surfactants such as amines) Ply i- is applied to the surface of the adherend that has an adhesive surface, and after wiping off the excess primer with paper or cloth as necessary, the α-cyanoacrylate-based primer is applied to the coated surface. By applying an adhesive and pasting together, even adherends having difficult-to-adhesive surfaces can be easily and quickly bonded.

However, the conventional primers described above generally have disadvantages in that they tend to stain adherends such as wood, and the pretreatment effect of the primer lasts for a very short time.

In other words, if the standing time (hereinafter referred to as "open time") from application of the primer to adhesion becomes long, the pretreatment effect deteriorates significantly. For this reason, with conventional primers, it is necessary to complete the adhesion work within a certain short period of time after applying the primer, which is extremely inconvenient in practice, and from the viewpoint of adhesive users. There was a need for a primer with a long-lasting pretreatment effect.

Further, as a primer capable of sustaining such a pretreatment effect, N,N-di-lower alkyl-P (or m
) - Toluidine as a base and a combination of saccharin and ascorbic acid or isoascorbic acid have been proposed (Japanese Patent Application Laid-open No. 1121-g).

However, although this primer has a considerable improvement effect compared to conventional primers, the pretreatment effect clearly deteriorates when the oven time exceeds 2'1 hour, so it cannot be said to be fully satisfactory. .

Furthermore, conventional primers also have the drawback of not having sufficient initial adhesive strength.

The present inventors have conducted various studies to improve the above-mentioned drawbacks of conventional primers, and as a result, they have arrived at the primer composition of the present invention as a primer that can achieve the objective.

That is, the primer composition for an α-cyanoacrylate adhesive of the present invention comprises a carboxyl group-containing polymer compound, a solvent with a boiling point of 10OC or less, and dimethylformamide, dimethylacetamide, N-methylpyrrolidone, 2
- Contains at least seven high-boiling compounds selected from the group consisting of oxazoline, ε-caprolactone, γ-butyrolactone, dimethyl sulfoxide, sulfolane, ethylene carbonate and hyfurobylene carbonate.
, the composition has a pH of 3 to IO.

The primer composition of the present invention is excellent in various respects as a primer for α-cyanoacrylate adhesives, and its pretreatment effect is extremely long-lasting, for example, even after an open time of 7 weeks. It can sufficiently exhibit the pretreatment effect and can provide adhesion with extremely high initial adhesion strength.

It goes without saying that the primer composition of the present invention can also be used as a primer for adherends other than those having the above-mentioned difficult-to-adhesive surfaces, such as various types of plastics, metals, glass, etc. be.

The carboxyl group-containing polymer compound used in the present invention includes, for example, polymerizable unsulfated carboxylic acids such as acrylic acid, methacrylic acid, maleic acid, crotonic acid, cinnamic acid, and itaconic acid, or derivatives thereof (such as monomethylmaleic acid). , dichloromaleic acid, α-methylcinnamic acid, methoxycinnamic acid, dichlorocinnamic acid, etc.).

In the case of a copolymer, examples of the comonomer include acrylic ester, methacrylic ester, vinyl acetate, vinyl chloride, vinylitine chloride, styrene, ethylene, propylene, and butylene. Furthermore, the copolymerized monomers include divinylbenzene, methylbisacrylamide, polyallyl sucrose, allyl group-containing acrylate, triallyl cyanurate, polyethylene glycol di(meth)acrylate, polyallylethyl, trimetachlorotriazine, Using polyfunctional compounds (crosslinking agents) such as trimethylene sulfone, triallylamine, allyl esters of phosphoric acid or phosphorous acid, tetravinylsilane, tetraallylsilane, tin or germanium derivatives of tetravinylsilane or tetraallylsilane, and allylamide phosphorus compounds. The polymer (copolymer) obtained by copolymerizing a small amount of such a polyfunctional monomer is a crosslinked polymer, and such a crosslinked polymer has a large molecular weight, It has a high solution viscosity and is particularly preferred as a carboxyl group-containing polymer compound used in the present invention. In addition, the carboxyl group-containing polymer compound has a viscosity (hereinafter referred to as
This is called "aqueous solution viscosity." ) is particularly preferred.

The content of the unsaturated carboxylic acid type pure component in the carboxyl group-containing polymer compound used in the present invention is 3 mol 5 or more, preferably 20 mol % or more.

In addition, since such carboxyl group-containing polymer compounds are widely commercially available under various trade names, suitable ones can be appropriately selected and used from these commercially available products in the present invention. Commercially available products include, for example, Carbo Ball Zal I Otsu, Dori Io, Dori Il/, Dori 317 (the above are Gutdrich product names), Hibis Wako 103, Dori IO'l, Dori 703 (the above are Wako Pure Yakusha product name, cross-linked acrylic acid polymer), Tamanori S-
//ri, G-3I) (the above is a trade name of Arayo Kagakusha Co., Ltd., vinyl acetate-maleic anhydride copolymer), Isopan 06, Isopan 10 (the above is a trade name of Kuraray Co., Ltd., isobutylene-maleic anhydride copolymer) CA-3IOH (product name of Kindai Kagaku Co., Ltd., styrene-maleic acid copolymer), Demol EP, CA-3IOH (product name of Kao Soap Co., Ltd., maleic acid-based polymer)
, Shion P W / / 0% same / / l (the above is a product name of Nippon Cotton Pharmaceutical Co., Ltd., crosslinked acrylic acid polymer),
Frimal ASE-1o (trade name of Rohm & Haas Co., Ltd., methacrylic acid copolymer) and the like can be mentioned.

The content ratio of the carboxyl group-containing polymer compound in the primer composition of the present invention is usually 0.007 to . 20% by weight, preferably o, oor to 10% by weight. If the content is too low, the primer performance will deteriorate, and if it is too high, the adhesive strength will be reduced.

Examples of the solvent with a boiling point of 10OC or less in the present invention include water, hydrophilic solvents such as methanol, ethanol, gropanol, acetone, tetrahydro-7rane, and methyl ethyl ketone, and these solvents can be used alone or in combination of two or more. It can also be used with a mixed solvent. These solvents mainly act as a solvent for the carboxyl group-containing polymer compound and the entire composition, and have the effect of facilitating the application of the primer composition.

The polymeric compound used in the present invention is selected from the group consisting of dimethylformamide, dimethylacetamide, N-methylpyrrolidone, co-oxazinone, ε-caprolactone, γ-butyrolactone, dimethyl sulfoxide, sulfolane, ethylene di-bonate and propylene carbonate. Seven types of these polymer compounds may be used alone, or two or more types may be used in combination.

In the present invention, the stone high boiling point compound exhibits an excellent effect on improving initial adhesive strength.

Although the details of its mechanism of action are not necessarily clear, the high-boiling point compound remains at the adhesive interface and acts like a plasticizer on the cured α-cyanoacrylate adhesive, thereby contributing to improving the initial adhesion. It is assumed that there are.

The proportion of high-boiling compounds in the primer composition of the present invention is usually 7 to 70% by weight, preferably! -! It is 0% by weight. If the ratio is too low, the effect of improving the initial adhesive strength will not be sufficiently exhibited, and if the ratio is too high, the adhesive strength will be reduced.

The pH of the primer composition of the present invention is adjusted within the range of 1 to 1O1, preferably 6 to 1O1. Such pH adjustment can be carried out using various basic compounds as pH adjusters. For example, sodium hydroxide, potassium hydroxide, calcium hydroxide, monoethanolamine, jetanolamine, triethanolamine, tolyl (or i)-propaturamine, ethylamine, diethylamine, triethylamine, propylamine, butylamine, stearylamine, oleylamine , ammonia, morpholine, cecylmorpholine, ethylenediamine, ethylenediamine polyethylene (or polypropylene) oxide adduct, alkylamine polyalkylene oxide adduct (e.g. oleylamine polyethylene oxide adduct, laurylamine polyethylene oxide adduct, etc.), N,N'-diamine Lower alkylene para (
or meta)-toluidine (e.g. N,N'-dimethyl para-toluidine, N,N'-diethyl para-toluidine, N,N'-dimethyl meta-toluidine, etc.), polyamide amine, etc. as a pH adjuster, and these PH
The pH of the composition is adjusted to a desired value by adding one kind of regulator alone or by adding two or more kinds in combination. In addition, there are no particular restrictions on the timing of adding the pH adjuster,
It can be added at any stage of primer composition preparation. Therefore, in some cases, a carboxyl group-containing polymer compound is prepared using an alkaline agent (P
It is also possible to prepare the primer composition of the present invention using one neutralized with H adjuster).

The primer composition of the present invention can contain other components as necessary.

For example, other solvents such as dioxane, toluene, glycerin, ethylene glycol, tripropylene glycol, fillers such as calcium carbonate, clay, talc, etc., polyethylene glycol, polypropylene glycol, liquid paraffin, chlorinated paraffin, waxes, and interfaces. Activators, coloring agents such as dyes and pigments, gelling agents, anionic polymerization promoters, and the like can be added to the primer composition of the present invention.

For reference, the primer composition of the present invention exhibits excellent remover performance when used as it is as a remover for various adhesives. For example, it has excellent remover performance against α-cyanoacrylate adhesives, rubber adhesives, cellulose adhesives, acrylic adhesives, vinyl acetate resin adhesives, urethane adhesives, etc. This is surprising and at the same time extremely advantageous for the practical application of the primer composition of the present invention.

Specifically, the primer composition of the present invention exhibits excellent effects for improving the adhesion of α-cyanoacrylate adhesives to adherends having difficult-to-adhesive surfaces as described above. However, it is surprising that the same composition has a peeling effect (remover effect) on the adhesive layer of the same α-cyanoacrylate adhesive once adhesively cured.

This is because, in general, the performance as an adhesive primer and the adhesive remover performance, which is the ability to peel off a hardened adhesive, are originally contradictory (or mutually contradictory) performances.

In addition, at sites where adhesives, particularly α-cyanoacrylate adhesives, are used, it is often necessary to peel off the cured adhesive at the same time as bonding. For example, α-cyanoacrylate adhesives are instant adhesives, so if you try to re-attach a piece that has been pasted together, the adhesive will have instantly hardened, and the adhesive will be stuck to the adherend. The same applies to cases where the adhesive accidentally adheres to areas other than the adhesive part, the skin of the worker, or various other objects. Once the α-cyanoacrylate adhesive has hardened, it is extremely difficult to peel it off (removal), and if you try to forcefully peel it off, you may damage the article or your skin. However, the primer composition of the present invention can be used as a remover as it is in such cases and has an excellent remover effect. This is an extremely advantageous point in the above). In addition,
It is believed that such remover performance in the primer composition of the present invention is mainly based on the action of the specific high-boiling compound contained therein.

The present invention will be described in detail below with reference to Examples and Comparative Examples.

Examples 7-g Comparative Examples/-g As shown in Table 7, various carboxyl group-containing polymer compounds, various solvents with boiling points below 100 t:', various high boiling point compounds, and various PH adjusters were combined. Use in conjunction with
The primer compositions of Examples/~g and Comparative Examples/~g are listed in the table/Notes/...trade name of a crosslinked carboxyl group-containing polymer manufactured by Gutdrich. Aqueous solution viscosity is 'Ag000cpsO *2... Trade name of crosslinked acrylic acid polymer manufactured by Wako Pure Chemical Industries. Aqueous solution viscosity decrease: 1000 ps0 Hata 3: Trade name of ethylenediamine polyethylene oxide adduct manufactured by Asahi Denka Co., Ltd.

*t...Nippon Nyukazai Co., Ltd.'s alkylamine polyethylene oxide adduct product name.

*j... "Actual/" and "Ratio/" are abbreviations for "Example/" and "Comparative Example/", respectively. The following applies accordingly.

Examples and Comparative Examples As shown in Table 2, primer compositions of Examples and Comparative Examples were prepared by combining various components.

Notes to Table 2 */...Same as note 1 for table/.

The primer compositions obtained in each of the above Examples and Comparative Examples were applied to two birch veneers (2j x 100 x 3 mm).
Immediately after the open time listed in Table 3 has elapsed, a commercially available α-cyanoacrylate adhesive (trade name: 3000 Gold, manufactured by Cemedine Co., Ltd.) is applied to the coated surface of one of the veneers, and This and the veneer coated with only the primer were pasted together and pressed together to form an area of 3. / 2 jσ, its set time and after lamination - / 77 It was measured according to the set time measurement method, and the tensile shear strength was measured at the tensile shear rate /Qmm/min.

The test results are shown in Table 3.

For reference, Table 3 also lists the remover performance when each primer composition was used directly as an IJ remover. In the remover performance test, the above-mentioned commercially available α-cyanoacrylate adhesive was applied to a copper plate, the primer composition was applied onto the coating film that was left to cure for 7 weeks, and after 2≠ hours it was wiped off with a cotton canvas. The removal state of the cured coating film was examined and evaluated when the coating was removed.
It is.

*2... Rimper performance evaluation was performed in accordance with the following.

○ It can be completely removed by wiping it with a cotton canvas. -It's here.

× Most of it can be removed by wiping it with a cotton canvas. I couldn't come.

Hata 3...In addition, 7 without primer treatment
The tensile shear strength after minutes is -Q, kff/cm", 4tg
The same intensity after hours was A, 2kff/crn''.

yM≠...Comparative example 10. /,? The birch wood veneer coated with the above formulation turned yellow on the coated surface after 72 hours and after 1A hour.

As is clear from the results in Table 3, the compositions of each example (and even the compositions of comparative examples whose pH is within the range of ), but there was no negative effect on set time at all. In addition, the compositions of each example containing a high boiling point compound exhibit an excellent effect on improving the initial adhesive strength of the adhesive.

Patent applicant: Cemedine Co., Ltd.

Claims (1)

[Claims] /) Carboxyl group-containing polymer compound, boiling point 10θC
At least one of the following solvents is selected from the group consisting of dimethylformamide, dimethylacetamide, N-methylpyrrolidone, 2-oxazoline, ε-caprolactone, γ-butyrolactone, dimethylsulfoxide, sulfolane, ethylene carbonate and propylene carbonate. 1! A primer composition for an α-cyanoacrylate adhesive, which contains a high boiling point compound and has a pH of from j to 10. 2) The composition according to claim 7, wherein the carboxyl group-containing polymer compound is a crosslinked polymer compound. J) PH adjustment is triethanolaminy,) li%
(1d=)-7' Lovanolamine, amine polyalkylene oxide adduct in alcohol, ethylenediamine polyalkylene oxide adduct, and sodium hydroxide. A composition according to claim 1 or 2, comprising: