JPH08209100A - Urethane-based adhesive - Google Patents

Abstract

PURPOSE: To obtain an urethane-based adhesive composed of a main agent component obtained by mixing a vinyl chloride-vinyl acetate copolymer resin to a thermoplastic polyurethane resin used as a main component and dissolving the mixture in an organic solvent and a specific curing agent component and exhibiting excellent adhesive force to a soft vinyl chloride sheet. CONSTITUTION: This urethane-based adhesive is composed of (A) a main agent component produced by mixing 100 pts.wt. of a thermoplastic polyurethane resin as a main component with preferably 20-100 pts.wt. of a vinyl chloride- vinyl acetate copolymer resin and dissolving the mixture in an organic solvent such as acetone and (B) preferably 3-50 pts.wt. (based on 100 pts.wt. of the thermoplastic polyurethane resin) of a curing agent component consisting of a polyisocyanate compound such as triphenylmethane triisocyanate.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an organic solvent type urethane adhesive which is excellent in adhesion of a soft polyvinyl chloride sheet or film.

[0002]

2. Description of the Related Art Conventionally, solvent-based polyurethane adhesives have excellent flexibility and excellent plasticizer resistance. Therefore, molded products such as polyvinyl chloride sheet or film containing a large amount of plasticizer, Other plastic materials,
It is used in many fields as a universal adhesive because it adheres well to wood and metal.

[0003]

However, there is a problem in that the initial adhesive force immediately after the bonding and the adhesive force due to the plasticizer moving from the adherend to the adhesive interface are lowered.

An object of the present invention is to provide a polyurethane adhesive having excellent adhesion to soft vinyl chloride and excellent initial adhesive strength.

[0005]

SUMMARY OF THE INVENTION The present invention mainly comprises a thermoplastic polyurethane resin, a main component component obtained by mixing a vinyl chloride-vinyl acetate copolymer resin and dissolving it in an organic solvent, and a polyisocyanate compound as a curing agent component. It is a urethane-based adhesive characterized by consisting of.

The main component of the urethane adhesive of the present invention,
The main thermoplastic polyurethane resin is an elastomer having a urethane bond in the molecular chain and is usually a polybasic acid (terephthalic acid, isophthalic acid, phthalic acid, succinic acid, adipic acid, azelaic acid, sebacic acid, etc.) And a dihydric alcohol (ethylene glycol 1,4-butanediol 1,5-pentanediol 1,6-hexanediol, diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol, etc.) are subjected to a condensation reaction to obtain a terminal hydroxyl group. With respect to the saturated polyester resin having, the active hydrogen group and diisocyanate compound (tolylene diisocyanate,
It is a linear polymer that reacts with the isocyanate groups of diphenylmethane diisocyanate, hexamethylene diisocyanate, xylylene diisocyanate, cyclohexylmethane diisocyanate, etc., in approximately equivalent amounts.

Next, the vinyl chloride-vinyl acetate copolymer resin preferably has a vinyl chloride component content of 80 to 97% by weight and a degree of polymerization of about 200 to 800. Further, the copolymer does not necessarily have to be a vinyl chloride component and a vinyl acetate component alone, and may contain a vinyl alcohol component, a maleic acid component and the like within a range that does not impair the object of the present invention. Examples of such vinyl chloride-vinyl acetate copolymer resin include S-REC A, S-REC C, S-REC M (these are manufactured by Sekisui Chemical Co., Ltd.), Denka Vinyl # 1.
000GXT, Denka Vinyl # 1000CX, Denka Vinyl # 1000A, etc. (above, manufactured by Denki Kagaku Kogyo Co., Ltd.), Vinylite VAGH, Vinylite VYLF, Vinylite VMCA, etc. (above, Union Carbide)
Etc.

The vinyl chloride-vinyl acetate copolymer resin is preferably used in an amount of 20 to 100 parts by weight based on 100 parts by weight of the thermoplastic polyurethane resin. A mixing amount of 20 parts by weight or less does not contribute to the improvement of adhesion with vinyl chloride, and a mixing amount of 100 parts by weight or more deteriorates heat resistance.

Examples of the organic solvent that can be used as a solvent include ester-based solvents such as ethyl acetate and butyl acetate, ketone-based solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone, aromatic-based solvents such as xylene and toluene, trichlene and methylene chloride. Examples include chlorine-based materials. These organic solvents can be used alone or in combination.

The polyisocyanate compound as a curing agent component is an isocyanate compound used as a cross-linking agent for an ordinary chloroprene solvent type adhesive or a thermoplastic polyurethane resin (urethane rubber) adhesive, and has a high vapor pressure, and it is harmful to the human body. As long as it is less toxic and easy to handle, for example, triphenylmethane triisocyanate (Dismoder R manufactured by Bayer, 20% methylene chloride solution), triisocyanate phenylthiophosphate (Dismodur RF, 20% chloride) Methylene solution), an isocyanate compound obtained by adding trimethylolpropane to tolylene diisocyanate (Coronate L made by Nippon Polyurethane Co., 75% ethyl acetate solution),
Specific grade MDI (Millionate MR manufactured by Nippon Polyurethane Co., Ltd.) and the like can be mentioned.

The polyisocyanate compound contributes to the improvement of the adhesive strength because the active hydrogen group of the hydroxyl group in the thermoplastic polyurethane resin in the main component reacts and crosslinks, and the amount used is the solid content weight conversion value. Then, it may be selected so as to be 3 to 50 parts with respect to 100 parts of the thermoplastic polyurethane resin.

The polyurethane adhesive according to the present invention is of practical use as a two-component organic solvent type comprising the above-mentioned main component and hardener component. A rosin resin or a rosin derivative such as a rosin resin pentaerythritol ester, a glycerol ester, a hydrogenated rosin resin, or a hydrogenated rosin resin methyl ester may be used as a tackifying resin for the adhesive main component, if necessary. , Triethyleneglycol ester, pentaerythritol ester, rosin ester, polymerized rosin resin, glycerol ester of polymerized rosin resin and the like may be blended in appropriate amounts.

An example will be described below. Parts in the examples indicate parts by weight.

【Example】

Example 1 Thermoplastic polyurethane resin Dismicol 526 (Sumitomo Bayer Urethane, adipic ester TDI type)
100 parts by weight (hereinafter simply referred to as "part"), vinyl chloride-
Vinyl acetate VMGH (manufactured by Union Carbide Co., Ltd.) 50 parts, and neotol 85 (Harima Kasei, rosin ester resin) 150 parts tackifier, 600 parts methylene chloride and 100 methyl ethyl ketone.
Part of the mixture was mixed and dissolved in the mixed solvent to obtain the main ingredient.

A polyisocyanate compound Coronate L (manufactured by Nippon Polyurethane Co.) was used as a curing agent component.

The adhesive of Example 1 was prepared by mixing 100 parts of the main component and 10 parts of the curing agent.

Comparative Example 1 An adhesive of Comparative Example 1 was prepared in the same manner as in Example 1 except that the vinyl chloride-vinyl acetate copolymer resin, vinylite VMGH, was not used.

Next, the adhesive of Example 1 and Comparative Example 1 was applied to a wiping type soft vinyl chloride sheet having a thickness of 180 μm with a 100 μm hand applicator to prepare 3
The test piece was attached to a 12 mm thick MDF (medium density fiber board) which was kept warm at 0 ° C. and pressed with a pinch roll.

This test piece was subjected to 2 at 20 ° C. and 65% RH.
After curing for 4 hours, 180 ° peeling adhesion strength [N / 25 mm] at 20 ° based on JIS K6854, and
Load 0.5kg per 25mm width in 90 ° direction 60
After standing still at 0 ° C, the heat resistance strength for measuring the peeling length [mm] after 24 hours was measured. Also, the fracture state after the measurement was observed. The results are shown in Table 1.

[0019]

[Table 1]

[0020]

INDUSTRIAL APPLICABILITY As described above, the urethane-based adhesive containing vinyl chloride-vinyl acetate of the present invention exhibits excellent adhesive force to a soft vinyl chloride sheet.

Claims (1)

[Claims] 1. A urethane-based composition comprising a thermoplastic polyurethane resin as a main component, a vinyl chloride-vinyl acetate copolymer resin mixed and dissolved in an organic solvent, and a polyisocyanate compound as a curing agent component. adhesive.