JPH03149279A - Heat resistant adhesive composition - 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] [Field of Industrial Application] The present invention relates to a heat-resistant adhesive used for bonding textile products such as woven fabrics and non-woven fabrics to plastic sheets such as soft polyvinyl chloride sheets and polyurethane sheets. Regarding the composition.

[Prior Art] Polyurethane/polyfunctional incyanate adhesives have conventionally been used as heat-resistant adhesives for woven fabrics/plastic sheets.

The polyurethane/polyfunctional isocyanate adhesive described above is a good adhesive that is easy to use, does not impair the flexibility of the adhesive, and provides strong adhesive strength, heat resistance, and durability.

[Problems to be Solved by the Invention] In polyurethane heat-resistant adhesives that have been commonly used, the curing agent used therein is a trifunctional or higher functional polyisocyanate. Therefore, the obtained adhesive was a thermosetting three-dimensional crosslinked product, which had a major drawback of poor stability from coating to lamination (uncoated pot life).

Therefore, in this type of processing, it is necessary to carry out the process from coating to lamination in a continuous process, or to impose process constraints such as significantly limiting the time from coating to lamination.

The present invention aims to eliminate the deficiencies of the prior art described above.

[Means for Solving the Problem 1] The present inventors have conducted extensive research in order to obtain a heat-resistant adhesive that can be laminated at a relatively low temperature around ISO ℃ at any time after coating. As a result, it was discovered that a polyurethane adhesive using a bifunctional polyisocyanate prepolymer as a curing agent has excellent workability, adhesiveness, and heat resistance, and the present invention was achieved.

That is, the present invention provides a heat-resistant adhesive composition comprising a polyurethane resin having a heat softening temperature of less than 100° C. and a bifunctional polyisocyanate prepolymer having a molecular weight of less than 4000 as the curing agent 2. It is something to do.

The present invention will be explained in more detail below.

The bifunctional polyisocyanate prepolymer with a molecular weight of less than 4,000 used in the present invention is prepared by combining a bifunctional polyol and a bifunctional isocyanate with N G Olo H according to a conventional method.
It can be easily obtained by reacting at a ratio of 1.1 or more and, if necessary, using a small amount of a chain extender.

As the bifunctional polyol used in the present invention, conventionally known polyols used in ordinary polyurethane production are used.
They can be used alone or in combination of two or more. The molecular weight of the polyol is preferably 3000 or less. When a polyol with a molecular weight of 3000 or more is used, the N of the resulting polyisocyanate prepolymer is
This is because the GO content inevitably becomes low and a sufficient improvement in heat resistance due to curing cannot be expected.

Preferably, the polyol used in the present invention has a terminal group of hydroxyl group and a molecular weight of 700 to 4.
000 polyethylene adipate, polyethylene propylene adipate, polyethylene butylene adipate, polydiethylene adipate, polybutylene adipate, polyethylene succinate, polybutylene succinate,
Polyethylene sebacate, polybutylene sebacate, polytetramethylene ether glycol caprolactoneol, polyhexamethylene adipate, carbonate polyol, polyethylene glycol,
Examples include polygelopyrene glycol.

The bifunctional isocyanate used in the present invention is a compound having at least two incyanate groups in an aliphatic or aromatic compound, and has been widely used as a synthetic raw material for polyurethane resins. It is.

Any of these known difunctional incyanates are useful in the present invention. Particularly preferred bifunctional incyanates are as follows.

Tolylene diisocyanate, 4-methoxy-1,3-7
x Nylene diisocyanate, 4-isopropyl-1,3
-phenylene diisocyanate, 4-chloro-1,3-
Phenyl diisocyanate, 4-butoxy-1,3-
Phenyl diisocyanate, 2,4-diisocyanate-diphenyl ether, menthylene diisocyanate, 4,4'-methylenebis(phenylisocyanate)
, shuryl diisocyanate, l,5-sphthalene diisocyanate, penzidine diisocyanate 1-% o
-Nitrobenzidine diisocyanate, 4,4-dibenzyl diisocyanate, l*4-tetramethylene diisocyanate, l,6-tetramethylene diisocyanate, 1,10-decamethylene diisocyanate, 1,4-
Cyclohexylene diisocyanate, xylylene diisocyanate 1-,4,4-methylenebis(cyclohexyl isocyanate), U,S-tetrahydronaphthalene diisocyanate, isophorone diisocyanate, and the like.

Furthermore, the chain extenders used in the present invention include ethylene glycol, propylene glycol, diethylene glycol,
Examples include 1,4-butanediol, 1,6-hexanediol and water.

Furthermore, the polyurethane resin having a heat softening temperature of less than 100°C, which is the main ingredient of the adhesive composition of the present invention, has a molecular weight of 50°C.
0 to 3000 difunctional linear polymer glycols, such as one or two dihydroxy polyesters, dihydroxy polyesteramides, polyether glycols, etc.
A mixture of more than one species and the above-mentioned organic polyisocyanate,
It is produced by reacting in a solvent in the presence of a catalyst - or by reacting the polymer glycol and the organic polyisocyanate without the use of a solvent in a mixer such as a Nigu, or continuously in a twin screw extruder. It was manufactured by

When producing the heat-resistant adhesive composition of the present invention, 2 to 100 parts by weight of the bifunctional polyisocyanate prepolymer having a molecular weight of less than 4000 is blended with 100 parts by weight of the polyurethane resin having a heat softening temperature of less than 100°C. .

If it is less than 2 parts by weight, the heat resistance will not be sufficient, and if it exceeds 100 parts by weight, the original performance of the adhesive will not be exhibited and it will not be economical, which is not preferable.

[Example J Hereinafter, the present invention will be specifically explained with reference to Examples.

Example 1 800 parts by weight of polybutylene adipate (molecular weight approximately 500) and 800 parts by weight of MD I were mixed into a 2-t flask equipped with a thermometer, stirrer, and distillation tube, heated to 80°C, and reacted for 3 hours. Ta. Remove the reactant from the flask,
After cooling, a bifunctional polyisocyanate prepolymer (referred to as curing agent A) was obtained.

The NCO% of the obtained curing agent A was 8.1% (theoretical value 8.4
%)Met.

Eighty-eight parts by weight of this curing agent was added to 400 parts by weight of a thermoplastic polyurethane resin solution (manufactured by Bayer AG, trade name: Desmocol 400T, 25% methyl ethyl ketone solution) to obtain a heat-resistant adhesive composition.

Its physical properties are shown in Table 1.

Example 2 12 parts by weight of the curing agent A of Example 1 was added to a thermoplastic polyurethane resin solution (manufactured by Bayer AG, trade name: Desmocol 40).
0T, 25% methyl ethyl ketone solution) to obtain a heat-resistant adhesive composition. Its physical properties are shown in Table 1.

Example 3 Instead of polybutylene adipate in Example 1, poly-
A bifunctional polyisocyanate prepolymer (referred to as curing agent B) was obtained in the same manner as in Example 1, except that 1000 parts by weight of ε-caprolactone polyol (molecular weight approximately 1000) and 500 parts by weight of MDI were used. Ta. The NCO% of the obtained curing agent B was 5.6% (theoretical value 5.6%)
Met.

12 parts by weight of this curing agent B was added to a thermoplastic polyurethane resin solution (manufactured by Bayer AG, trade name: Desmocol 4).
00T, 25% methyl ethyl ketone solution) to obtain a heat-resistant adhesive composition.

Its physical properties are shown in Table 1.

Example 4 18 parts by weight of the curing agent B of Example 3 was added to a thermoplastic polyurethane resin solution (manufactured by Bayer AG, trade name: Desmocol 40).
0T, 25% methyl ethyl ketone solution) to obtain a heat-resistant adhesive composition. Its physical properties are shown in Table 1.

Example 5 Instead of polybutylene adipate in Example 1, 100% polytetramethylene glycol (molecular weight approximately 2000) was used.
A bifunctional polyisocyanate prepolymer (referred to as curing agent C) was obtained in the same manner as in Example 1, except that 0 part by weight was used and the amount of MDI was 250 parts by weight. The NCO% of the obtained curing agent C was 3-3% (theoretical value 3.4%).

20 parts by weight of this curing agent C was added to a thermoplastic polyurethane resin solution (manufactured by Bayer AG, trade name: Desmocol 400T).
, 25% methyl ethyl ketone solution) to obtain a heat-resistant adhesive composition.

Its physical properties are shown in Table 1.

Example 6 30 parts by weight of the curing agent C of Example 5 was added to a thermoplastic polyurethane resin solution (manufactured by Bayer AG, trade name: Desmocol 40).
0T, 25% methyl ethyl ketone solution) to obtain a heat-resistant adhesive composition. Its physical properties are shown in Table 1.

Comparative Example 1 A trifunctional polyisocyanate (manufactured by Oguchi Seika Kogyo Co., Ltd., trade name: Seirypon UD-C) was used as a curing agent.

Using 5 parts by weight of NC0% 12-14%), this was added to a thermoplastic polyurethane resin solution (manufactured by Bayer AG, trade name: Desmocol 400T, 25% methyl ethyl ketone solution) 4
00 parts by weight to obtain an adhesive composition. Its physical properties are shown in Table 1-2.

Comparative Example 2 An adhesive composition was obtained in the same manner as Comparative Example 1, except that 15 parts by weight of the trifunctional polyisocyanate of Comparative Example 1 was used.

Its physical properties are shown in Table 1.

Comparative Example 3 The thermoplastic polyurethane resin solutions of Examples and Comparative Examples without any curing agent were used as adhesives, and the physical properties were investigated. Table 1 shows the results.

Nari 1 The physical property test was conducted as follows.

(1) Film Physical Properties A film with a thickness of 50 μm was prepared and a tensile test was conducted at a tensile speed of 200 taII/im.

(2) A load of 450ylc layer 2 was applied to a film having a heat softening temperature of 507z, and the temperature was raised at a rate of 2°C/sin, and the temperature at which the film broke was defined as the heat softening temperature.

(3) Suitability for pre-coating Tetron taffeta was coated with adhesive and dried (129 solids/m). This and soft PVC were laminated at 150°C immediately after drying and after being coated for one week. After aging, adhesive was applied. The strength was measured by a method according to JIS K 6854.

[Effect of the Invention J] Since the adhesive composition of the present invention uses a bifunctional polyisocyanate prepolymer as a curing agent, a high-temperature thermoplastic cured product can be obtained. Furthermore, the heat resistance temperature can be arbitrarily selected from the thermosetting temperature of the base polyurethane resin to 180° C. depending on the addition ratio of the curing agent, and the thermal reactivation temperature can be freely set.

Utilizing these characteristics, the pot life of the coating, which has been regarded as a drawback in industry, has been improved, and lamination processing can be carried out at a relatively low temperature of around 150° C. at any time after coating.

Claims (1)

[Claims] 1. A heat-resistant adhesive composition comprising a polyurethane resin having a heat softening temperature of less than 100° C. and a bifunctional polyisocyanate prepolymer having a molecular weight of less than 4,000 as a curing agent.