JP2509847B2 - Fast curing adhesive and bonding method - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a two-liquid fractional coating type quick-setting adhesive and a bonding method thereof.

[0002]

2. Description of the Related Art Recently, in the wood industry and the like, there has been an attempt to continuously mass-produce a production process by a conveyor system, and an adhesive having a high adhesion speed has been demanded. A cyanoacrylate instant adhesive is considered for this purpose, but it is not practical because of its high price. Further, as a two-component differential coating type quick-setting adhesive, a urea resin adhesive is used as the component A, and a strong acid such as phosphoric acid is mixed with an aqueous solution of a polymer compound such as polyvinyl alcohol (PVA) to be the component B. However, it has been on the market for quite some time. However, this strong acid has a drawback that it accelerates the aging property of the urea resin system and deteriorates the strength of the wood itself, and is not widely used.

Further, it consists of an aqueous solution of a soluble protein having an amide bond in the molecule, or an aqueous solution of a synthetic polymer compound having an imide group and a first solution comprising an aqueous emulsion and a second solution comprising an aqueous solution of a water-soluble dialdehyde compound. A fast-curing adhesive composition (Japanese Patent Publication No. 63-17871) is also disclosed.

Further, a first liquid consisting of an aqueous solution and / or an aqueous emulsion of a polymer compound having an acetoacetyl group in the molecule and a fast-curing aqueous adhesive consisting of a second liquid consisting of an aqueous solution of an aldehyde compound are bonded. A method (Japanese Patent Publication No. 1-60190) is also disclosed.

Further, a first liquid consisting of an aqueous solution and / or an aqueous emulsion with a polymer compound having an acetoacetyl group in the molecule, and an instantaneous curing aqueous adhesive consisting of a second liquid consisting of an aqueous solution of a hydrazine compound. A bonding method (Japanese Patent Publication No. 1-60192) is also disclosed.

However, the above-mentioned two-liquid fractional coating type adhesive has the following drawbacks.

[0007]

A cyanoacrylate-based instant adhesive is expensive and unrealistic. A urea resin-based adhesive is used as the component A, and an aqueous solution of a polymer compound is mixed with a strong acid such as phosphoric acid to be used as the component B. In the product,
It is not widely used because it has the drawback of promoting the aging properties of the urea resin system and deteriorating the strength of the wood itself. Further, in a two-liquid fractional coating type adhesive composition utilizing a crosslinking reaction between a polymer having an imide group in the molecule and a dialdehyde,
Since the crosslinking reaction is a reversible reaction due to heat, there is a problem in durability. Further, a polymer compound having an acetoacetyl group in the molecule has a problem that it has a high storage stability as an aqueous solution and a high dependency of a crosslinking reaction by PH.

[0008]

DISCLOSURE OF THE INVENTION The present invention comprises a solution A comprising an aqueous solution and / or an aqueous emulsion of a polymer compound having a hydrazito group and / or a hydrazine group in the molecule, and an aqueous solution or dispersion solution of a carboxyl compound. It is a fast-curing adhesive consisting of two liquids, B liquid, and
This is a bonding method in which the two liquids of the A liquid and the B liquid are separately applied and the adherends are stuck together.

In the present invention, a hydrazide group and / or
Alternatively, a polymer compound having a hydrazine group means that a multicomponent copolymer of polymerizable α, β-unsaturated compounds and maleic anhydride is reacted with hydrazine, and a part of maleic anhydride in the molecule is hydrazide. It is a polymer compound that can be obtained by hydrating and / or hydrazinizing it, and can be dissolved in water as it is, or a basic substance (alkali metal carbonate, ammonium carbonate, ammonium phosphate, alkaline weak acid salt such as borax). , A hydroxide of an alkaline earth metal, or a water-soluble basic organic compound such as ammonia, ethanolamines, morpholine, etc.) is added to solubilize the solution into an aqueous solution. Or
After solubilizing the above multicomponent copolymer into an aqueous solution,
It can also be obtained by hydrazidation and / or hydrazination.

Examples of these multi-component copolymers are vinyl acetate-maleic anhydride, styrene-maleic anhydride, isobutylene-maleic anhydride, acrylic acid esters-maleic anhydride, methacrylic acid esters-maleic anhydride. And so on.

As the aqueous emulsion, an emulsion obtained by homoemulsifying mainly vinyl monomers such as vinyl acetate, acrylic acid ester and methacrylic acid ester, and emulsion polymerization of ethylene-vinyl acetate or acrylic acid ester. Such as a synthetic resin emulsion such as a copolymer emulsion and a rubber latex which is a rubber emulsion polymer such as natural rubber, isoprene rubber, styrene-butadiene rubber, butadiene rubber, butyl rubber, chloroprene rubber, nitrile rubber, and carboxyl groups thereof. There is a modified rubber latex with a functional group introduced,
These synthetic resin emulsions and rubber latices may be used alone or in admixture of two or more.

In the preparation of the solution A in the present invention, a 1-60% by weight aqueous solution of the polymer compound having a hydrazide group and / or a hydrazine group in the molecule obtained as described above, usually 10 Mix to an aqueous emulsion at a concentration of 50% to prepare a liquid A.

Next, as the aqueous solution or dispersion of the carboxyl compound, which is the liquid B in the present invention, oxalic acid,
Aqueous solutions or dispersions of malonic acid, menoxalic acid, oxaloacetic acid, succinic acid, malic acid, fumaric acid, maleic acid are preferred. The suitable concentration of the aqueous solution is usually 1 to 50%.

The adhesive of the present invention contains, in addition to the above-mentioned essential components, a filler (calcium carbonate, kaolin, clay, etc.), a plasticizer, a preservative, a coloring agent, a surfactant, and a viscosity adjusting agent, if necessary. Agents and the like can be added as appropriate.

Next, as a bonding method for adhering adherends using the fast-curing adhesive of the present invention, the liquid A and the liquid B are separately applied to the adhesive surfaces of the adherends and the adhesive surfaces are adhered. A method of contacting and pressing, for example, applying liquid A to the surface of wood,
There is a method in which the liquid B is applied to the surface of a slate plate or the like and immediately both surfaces are brought into contact with each other and pressed to bond them.

As a method of spraying the liquid A and the liquid B onto the adherend at the same time so that the spraying areas overlap each other, for example, either air spray or airless spray may be used.
Two spray guns or a double-headed spray gun can be used.

Further, a method of sticking the other adherend to the surface of one adherend on which the liquid A and the liquid B are applied separately, for example, a porous plate such as wood, plywood, particle board, slate plate, etc. There is a method of attaching a porous adherend such as foam or paper to the surface coated with the liquid A and the liquid B with an application tool such as a spray or a brush. The amount of adhesive to be applied is 10 to A liquid.
300 g / m ² (solid content), (a carboxyl compound) B solution 1 to 50 g / m ² are suitable.

[0018]

In general, a water-based adhesive cannot obtain a sufficient final adhesive strength at room temperature unless it is pressed for a considerably long time. However, the fast-curing adhesive of the present invention is left alone after being pressed for a short time. Sufficient final adhesive strength is obtained after curing. In this case, what is important is to apply the two solutions separately without mixing them.

This is because the reaction between the hydrazide group or hydrazine group and the carboxyl compound is so fast that when mixed and applied, gelation occurs during mixing and the gelled product does not exhibit adhesiveness. Next, the present invention will be described with reference to examples.

[0020]

【Example】

Example 1 In a four-necked flask equipped with a reflux condenser, isobutylene-maleic anhydride copolymer (trade name "Isoban 06", manufactured by Kuraray Isoprene Chemical Co., Ltd.) 54 parts by weight (hereinafter referred to as "part"), a solubilizer 25% ammonia water for industrial use as a mixture of 6 parts and 246 parts of water were added, and the mixture was stirred at 90 ° C. for 5
After reacting for a time to obtain a water-soluble isobutylene-maleic anhydride copolymer, and further using a suitable funnel, 6.7 parts of hydrazine hydrate (80% hydrated hydrazine, manufactured by Nippon Hydrazine Industry Co., Ltd.) was applied. By reacting for 1 hour, a 20% aqueous solution of a copolymer having a hydrazide group and / or a hydrazine group was obtained. To 100 parts of this aqueous solution, 150 parts of a 58% resin content acrylic emulsion adhesive (trade name "Aika Aibon RAX-70", manufactured by Aika Kogyo Co., Ltd.) and 50 parts of calcium carbonate as a filler are added, stirred and mixed, and liquid A is added. And Also, 20% of oxalic acid
The aqueous solution was designated as solution B. The two liquids of the above liquids A and B were used as the adhesive of Example 1.

Example 2 As the solution A, the same solution A as in Example 1 was used. As the solution B, a mixture of 50 parts of a 20% aqueous solution of oxalic acid and 2.5 parts of glycerin diglycidyl ether was used. The above-mentioned two liquids, A liquid and B liquid, were used as the adhesive of Example 2.

Comparative Example 1 The adhesive of Comparative Example 1 was prepared by using only the liquid A of Example 1.

Comparative Test Using the adhesives of Examples 1 and 2 and Comparative Example 1, JIS K
Table 1 shows the results of measuring the adhesive strength according to the method shown in "Testing method for split adhesive strength of adhesive".

The outline of the test method is as follows. Particle board (80 mm × 80 mm × 10 mm) and medium specific gravity fiber board (MDF) (85 mm × 80 mm × 2 mm), two pieces of adherends. Liquid A is applied to the particle board side of about 150 g / m
Apply ² times, apply the amount of solution B to the MDF side of about 30 g / m ² , adhere both sides closely, and immediately press at about 2 kg / cm ² for 5 seconds, immediately after decompressing, and after 24 hours (aging). ) Was measured. The ambient temperature in the test is 20
° C.

[0025]

[Table 1]

Claims (5)

(57) [Claims] 1. A liquid A comprising an aqueous solution and / or an aqueous emulsion of a polymer compound having a hydrazide group and / or a hydrazine group in the molecule and a liquid B comprising an aqueous solution or dispersion of a carboxyl compound. A fast-curing adhesive characterized in that 2. A liquid A comprising an aqueous solution and / or an aqueous emulsion of a polymer compound having a hydrazide group and / or a hydrazine group in a molecule, and a liquid B comprising an aqueous solution or dispersion of a carboxyl compound. A bonding method characterized by separately applying and adhering adherends. 3. The bonding method according to claim 2, wherein the method of separately applying and adhering the adherends is to separately apply the liquid A and the liquid B to the adhesive surface of the adherend and then to contact the adhesive surfaces. . 4. The bonding method according to claim 2, wherein the separately applying method is to spray the solutions A and B at the same time, mix them in the form of mist droplets, and apply the mixture to the adherend. 5. The method of separately applying and adhering an adherend, according to claim 2, wherein one of the adherends is separately superposed with the solution A and the solution B, and the other adherend is applied. Bonding method.