JPH09188860A - Adhesive composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an adhesive compsn. improved in initial adhesive power and its heat resistance and excellent in sprayability by combining a major component mainly comprising a specific chloropene latex and contg. specified amts. of an acrylic or SBR latex and an anionic surfactant with a curative. SOLUTION: This adhesive compsn. is of a two-component type and is a combination of a major component comprising 100 pts.wt. (solid basis) anionic chloroprene latex, 1-100 pts.wt. (solid basis) acrylic and/or SBR latex, and 0.01-10 pts.wt. nonionic or anionic surfactant with a polyvalent-meal salt as the curative.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a two-component water-based adhesive for porous substrates such as urethane foam.

[0002]

2. Description of the Related Art Solvent-based adhesives such as urethane-based adhesives, chloroprene-based adhesives, and acrylonitrile-butadiene rubber-based adhesives are mainly used as adhesives for forming plastic foams in automobile interior materials. It was However, there is a problem of occupational safety and health in the factory, a risk of fire, and a pollution problem due to environmental pollution. Therefore, there is an increasing demand for solvent-free adhesives from the viewpoint of resource saving.

On the other hand, pressure-sensitive acrylic emulsion adhesives have begun to be marketed in response to the recent needs for solvent-free type adhesives.
Further improvement in heat resistance, workability, etc. is required, and it has not been put to practical use.

Among the recent composite materials, as seen in molded ceilings, molded doors, etc., the composite materials have shifted to deep-draw molding, the appearance of foams having increased foam strength due to the composition change of urethane foam, and Practical problems have arisen due to increased heat resistance requirements, and improvements are unavoidable.

[0005]

SUMMARY OF THE INVENTION The object of the present invention is to solve problems of occupational safety and health, environmental pollution, etc. by using an aqueous emulsion type adhesive composition, and further, the cushioning property and texture of urethane foam. It is an object of the present invention to provide an adhesive composition which is excellent in initial adhesive strength and heat resistant adhesive strength without spoiling the adhesive property, and is also excellent in spray application property and storage stability of the adhesive composition itself.

[0006]

The present invention is based on 100 parts by weight of the solid content of anionic chloroprene latex.
1 to 100 parts by weight of acrylic emulsion or / and SBR latex as solid content, and 0.0% of nonionic or / and anionic surfactant as solid content.
An adhesive composition comprising two liquids of a main agent component containing 1 to 10 parts by weight and a curing agent component containing a polyvalent metal salt as a main component.

The anionic chloroprene latex used in the present invention has a solid content of 40 to 70 currently marketed.
%, Preferably 50-60%, viscosity 10-10,000 cp
It is a chloroprene latex which has a high crystallization rate of s, PH 7 to 13 and an excellent cohesive force.

The acrylic emulsion is mainly composed of ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, etc., vinyl compounds such as styrene, methyl methacrylate, acrylonitrile and the like, and acrylic acid, methacrylic acid, itacone as functional group monomers. An emulsion obtained by copolymerizing an acid, acrylic amide, methylol acrylic amide, hydroxyethyl acrylate, hydroxyethyl methacrylate, etc., and usually has a glass transition temperature (Tg) of 0 to -60 ° C, preferably 0 to
-30 ° C, viscosity 10 to 10000 cps, preferably 10
~ 1000 cps, solid content 40-70%, preferably 40
-60%, PH4-11 acrylic emulsion.

The SBR latex is acrylic acid, methacrylic acid, itaconic acid, acryl amide, methylol acryl as a functional group monomer at a copolymerization monomer ratio of styrene and butadiene of 1/9 to 9/1 by weight. Glass transition temperature (Tg) of copolymerization of amide, hydroxyethyl acrylate, hydroxyethyl methacrylate, etc. 0 to -60 ° C, viscosity 50 to 10000 cps, preferably 50 to 500 cps, solid content 40 to 60%, PH6
˜11 commercially available SBR latexes are mentioned.

Acrylic emulsion or / and S
The content of the BR latex is 1 to 100 relative to 100 parts by weight of the solid content of the anionic chloroprene latex.
Parts by weight, preferably 40 to 60 parts by weight. If the content ratio is too low, no improvement in cohesive force and heat resistance of the coating film is observed, and if it is too high, the mechanical stability of the system deteriorates,
Storability and coating workability deteriorate.

The content ratio of the acrylic emulsion and the SBR latex is not particularly limited, but in order to increase heat resistance, a large amount of acrylic emulsion having a high film-forming temperature is blended, and SBR is used for the purpose of cost reduction. Add a lot of system emulsion.

As the nonionic surfactant, polyoxyethylene lauryl ether, polyoxyethylene cetyl ether, polyoxyethylene stearyl ether,
Examples include polyoxyethylene alkyl ethers such as polyoxyethylene oleyl ether, polyoxyethylene octyl phenyl ether, and polyoxyethylene nonyl phenyl ether, polyoxyethylene alkyl allyl ether, and polyoxyethylene derivatives.

Examples of the anionic surfactant include fatty acid salt, alkyl sulfate salt, alkylbenzene sulfonate and the like.

The content ratio of the nonionic and / or anionic surfactant is 0.01 to 10 parts by weight, preferably 0.1 to 2 parts by weight, as solid content.

The content ratio of the nonionic surfactant and the anionic surfactant is such that nonionic / anion = 5/1 to 3 /
About 1 is preferable.

Next, the polyvalent metal salt serving as the curing agent component is
Acetic acid such as magnesium, barium, aluminum, manganese and iron, organic salts such as oxalic acid, tartaric acid and benzoic acid,
There are also metal salts such as chlorides, bromides, iodides, nitrates and sulfates and some chelate salts, which are dissolved in water or alcohol and used at a concentration of 0.1 to 50% by weight.

The adhesive of the present invention includes a tackifier such as rosin and petroleum resin, a filler such as calcium carbonate,
A plasticizer such as DBP or DOP, a coloring agent, a preservative, a viscosity adjusting agent and the like can be added as appropriate.

In the present invention, when the anionic surfactant in the main component comes into contact with the polyvalent metal salt in the hardener component, the latex (or emulsion) is rapidly broken and the particles are fused together. Then, a resin layer is formed and a film is formed to have tackiness and exhibit an initial adhesive force.

The method of using the two-component adhesive of the present invention is as follows:
Since the above reaction is carried out in a tank or in a tube, the main component and the curing agent component are used in a separate coating. As a method therefor, a spray gun having two or more nozzles is used.
Main component and hardener component are sprayed separately, and contacted in air or on the adherend, and applied to one adherend in a state where the latex (or emulsion) is destroyed or very unstable. After the layer is formed, the other adherend is pressure-bonded, the main component is applied to one adherend, the curing agent component is applied to the other adherend, and then both adherends are contacted with each other. There is a method in which an adhesive layer is formed and pressure-bonded to adhere.

The type of the adherend is not limited at all, but in the case of instant bonding with a spray or the like, a porous material capable of dissipating water is used for one or both of them. It is desirable to use various foams, wood,
Examples include threading, fiber, felt, hardboard, and glass fiber.

[0021]

【Example】

Examples 1 to 3 Anionic chloroprene latex constituting the main component (Denka chloroprene latex LA-50, solid content 50%, PH12 or more), acrylic emulsion (Mitsubishi Yuka Birdish Co., Ltd.) , Room temperature crosslinkable acrylic emulsion, Acronal Y
J-2740D, solid content 48%, PH 7.5-9.5),
SBR latex (Takeda Pharmaceutical Co., Ltd., Crosslen SK-73, solid content 42%, PH 11.0), nonionic surfactant (Kao Corporation, polyoxyethylene nonylphenyl ether, Emulgen 910, HLB1).
2.2), anionic surfactants (Kao Corporation, sodium lauryl sulfate, Emal 10 needles) are shown in Table 1.
The parts (parts by weight) shown in Table 1 were blended to prepare a base material for the adhesives of Examples 1 to 3.

As the polyvalent metal salt of the hardener component, a 20% aqueous solution of calcium nitrate Ca (NO ₃ ) ₂ was used as the hardener.

Comparative Example 1 The adhesive of Comparative Example 1 was prepared by removing the acrylic emulsion from Example 1.

Comparative Example 2 The adhesive of Comparative Example 2 was prepared by removing the anionic surfactant from Example 3.

Comparative Example 3 The adhesive of Comparative Example 3 was prepared by removing the acrylic emulsion and the nonionic surfactant in Example 1.

Next, for the purpose of measuring the T-type peeling adhesive strength, 90 parts of the main agent and 10 parts of the curing agent were spray-mixed onto the canvas of the adherend and one side of the canvas using a double-headed gun spray. Then, apply about 100 g / m ² and bond them without drying time, measure the initial adhesive strength immediately after pressing with a pinch roller and the heat resistant adhesive strength at 60 ° C after curing for 3 days at 20 ° C, and measure The values are shown in Table 1.

Next, for the purpose of measuring the spray coating performance, an air gun with a diameter of 2 mm (Iwata coating machine, air spray gun W-88) was used, and the atomizing air pressure was 3 Kg / cm ² and the discharge rate was 1 Kg / min. The coating is continuously applied for 30 minutes under the conditions, and the time until clogging of the gun nozzle portion is measured, and the measured values are shown in Table 1.

[0028]

[Table 1]

[0029]

As described above, the adhesive composition of the present invention is
The initial adhesive strength and heat resistant adhesive strength are excellent, and the spray coating property is also good, which contributes to improving the productivity of the bonding work.

Claims (1)

[Claims] 1. An acrylic emulsion or / and SBR latex as a solid content of 1 to 1 relative to 100 parts by weight of a solid content of an anionic chloroprene latex.
It is composed of two liquids: a main component containing 00 parts by weight, 0.01 to 10 parts by weight of a nonionic or / and anionic surfactant as a solid content, and a curing agent component containing a polyvalent metal salt as a main component. An adhesive composition comprising: