JPS6264880A - Adhesive - Google Patents

Abstract

PURPOSE:To provide an adhesive which is excellent in initial bonding strength, hydrolysis resistance, heat resistance and durability and enables high-speed bonding and which comprises a particular polyester polyurethane and an isocyanate compd. CONSTITUTION:A mixed diol comprising 50-100wt% 8-12C alpha,omega-dialkanediol (e.g., 1,9-nonanediol) and 50-0wt% 7C or lower low-molecular diol (e.g., ethylene glycol) is reacted with a 6-12C aliphatic or arom. dicarboxylic acid (e.g., adipic acid) to obtain a polyester polyol having an MW of 1,000-10,000. The polyester polyol is reacted with an org. diisocyanate (e.g., 2,4-tolylene diisocyanate) to obtain a polyester polyurethane having a number-average MW of 10,000-70,000 and having a hydroxyl group at its both ends. 100pts.wt. polyester polyurethane is blended with 5-40pts.wt. compd. having at least three isocyanate groups in its molecule to obtain an adhesive. A vinyl chloride resin is bonded to other base material through the adhesive.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an adhesive with excellent adhesive properties, chemical and physical properties, which is composed of a polyester polyurethane and a compound having three or more isocyanate groups in the molecule. . In particular, the present invention relates to an adhesive having extremely excellent performance when the adherend is a vinyl chloride resin.

Prior art flexible plastics contain a number of plasticizers. Therefore, during adhesion, the plasticizer migrates to the N and N surfaces in contact, so sufficient consideration must be given to selecting the adhesive. Polybutylene adipate glycol is an adhesive (hereinafter referred to as "poly9-9-urethane") obtained from a polymeric polyol such as polyhexamethylene adipate glycol and an organic polyisocyanate (hereinafter referred to as polyester-based polyurethane) as a living body. Polyurethane-based ship-saving agents (6) exhibit excellent performance as adhesives for soft PVC because they prevent the migration of plasticizers through the crystallization of the polyurethane. Therefore, these polyurethane adhesives are suitable for bonding semi-rigid or rigid PVC, films such as acrylic resin, AB8 resin, non-woven fabrics of chemical fibers such as polyamide and polyester, fabrics such as knitted and woven fabrics, and even polyethylene. , polypropylene, urethane 7 ohm, artificial leather, synthetic leather, footwear,
Widely used for adhesive processing of bags, etc.

Problems to be Solved by the Invention However, the polyurethane adhesive described above still has a slow crystallization speed, and therefore its initial adhesive strength is still high. Therefore, for example, when vinyl chloride resin is bonded, the adhesive strength is sufficiently satisfactory (7).

Furthermore, these polyurethane adhesives are hydrolytic resistant,
In particular, it has drawbacks such as insufficient hot water resistance and a decrease in adhesive strength over time, causing various problems.

The purpose of the present invention is to provide a hardening polyurethane adhesive that has excellent initial adhesion strength, can be bonded at high speed, has excellent heat resistance and hot water resistance, and is durable with little performance deterioration over time. ! :) For.

Another object of the present invention is to provide a polyurethane adhesive Mk suitable for adhering vinyl chloride resin.

Means for Solving the Problems According to the book T. Akira, the above purpose is to solve the problem by
The average molecule t1ooo to 1000 (
Number average molecule @ 10,000 to 700 obtained by reacting the polyester polyol of No. 1 with an organic diisocyanate
Polyester polyurethane with hydroxyl groups at both ends of 00 (
This is achieved by an adhesive consisting of ~ (base agent) and a compound (13) having three or more isocyanate groups in the molecule (curing agent).

The polyester polyurethane used as the main ingredient in the adhesive of the present invention is an α,ω-alkanediol having 8 to 12 carbon atoms alone or/fi, a polyester polyol made from a mixed glycol and dicarboxylic acid containing the diol as a living body, and an organic diisocyanate. It can be obtained by reacting in a conventional manner.

Here, as an example of α,ω-alkanediol, in, 8
-Octanediol% 1.9-nonanediol, 1,
Mention may be made of 10-decanediol and 1,12-dodecanediol. Among them, 1,9-nonanediol is preferred.

α during the synthesis of the polyester polyol.

It is most preferable to use ω-alkanediol alone from the viewpoint of effectiveness, but when used in combination with a low molecular weight diol having 7 or less carbon atoms, it should generally be 50% by weight or more, although it varies depending on the type of low molecular weight diol. is important. α
The polyester polyol obtained using ω-alkanediol has extremely high crystallinity, and a characteristic feature is that even if low molecular weight diol is copolymerized within a range not exceeding 50 times JIk, s, the crystallinity does not decrease. of 1,4-butanediol is smaller than that of polyester polyol whose main component is 1°6-hexanediol.

In addition, examples of diols having 7 or less carbon atoms that can be used in combination within a range not exceeding 50% by weight include ethylene glycol, 1
, 4-butanediol, 1,6-hexanediol, diethylene glycol, neopentyl glycol, 3-methyl-1,5-bentanediol, and the like.

In some cases, a small amount of polyol having three or more hydroxyl groups, including triols such as trimethylolpropane and glycerin, may be used.

The ninth dicarboxylic acid for producing the polyester polyol is preferably an aliphatic or aromatic dicarboxylic acid having 6 to 12 carbon atoms. Among them, azelaic acid and adipic acid are particularly preferred.

When heat resistance is required, aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, and phthalic acid are preferably used.

These dicarboxylic acids may be used alone or in combination of two or more.

The polyester polyols are prepared by methods similar to those used in the production of polyethylene terephthalate, polybutylene terephthalate, polybutylene adipate or polyhexamethylene adipate, namely transesterification or direct esterification followed by melt polymerization. It can be produced by condensation reaction.

The polynister polyol has hydroxyl groups at both ends of the molecule, and the total number of hydroxyl groups in the polyester polyol is preferably 2 or more, preferably 2 to 4, and more preferably 2. The number of hydroxyl groups is appropriately controlled by selecting the polyol used.

The molecular weight of the above polyester polyol is 1,000 to i
o, ooo, preferably in the range of 2,000 to g, ooo. If it is outside this range, the initial adhesive strength or final adhesive strength will be significantly reduced, which is not preferable.

Suitable organic diisocyanates used for producing the polyester polyurethane used in the present invention are known aliphatic, cycloaliphatic or aromatic organic diisocyanates having two isocyanate groups in the molecule. % Particularly preferably used examples include 2.4-)lylene diiso7anate, 2,6-tolylene diisocyanate, 4.4'
-diphenylmethane diisocyanate, hexamethylene diisocyanate, inphorone diisocyanate, 4.
Examples include 4'-dicyclohexylmethane diisocyanate.

The polyester polyurethane is produced by reacting the polyester polyol with an organic diisocyanate in a conventional manner. At that time, if necessary, a chain extender having a molecular weight of 500 or less may be used.

The molecular weight of the above polyester poly9 urethane is 10.00
In the range of 0 to 70.000, preferably 15.00
It ranges from 0 to 40.000. If the molecular weight is outside these ranges, either the initial adhesive strength, final adhesive strength, or heat resistance will be poor.

81 The compound having three or more isocyanate groups in the molecule used as a curing agent in the adhesive of the present invention is a polyisocyanate of triisocyanate or more. Preferably used examples include compounds in which all of the hydroxyl groups of polyols such as trimethylolpropane, glycerin, and pentaerythritol are urethanized with tolylene diisocyanate, xylylene diisocyanate, or hexamethylene diisocyanate.

In the present invention, the compound having three or more incyanato groups in the molecule, that is, the curing agent, is blended in a proportion of 5 to 50 parts by weight, preferably 8 to 40 parts by weight, based on 100 parts by weight of the polyester-based polyurethane base material. It is desirable that it be within the range.

If the blending ratio is within this range, an adhesive with significantly improved adhesive strength, heat resistance, and solvent resistance can be obtained.The adhesive of the present invention may be dissolved in an organic solvent before use. . Suitable organic solvents include ethyl acetate, methyl ethyl ketone, tetrahydrofuran, and toluene. Further, the base agent may be used in the form of an aqueous dispersion by a conventional method. Furthermore, additives such as fillers, extenders, thickeners, dyes, pigments, deterioration inhibitors, etc. commonly used in adhesives may be added.

In addition, adhesive sea bream #! This can usually be carried out by mixing a polyester polyurethane (A) and a compound (B) having three or more incyanato groups in the molecule.

Similar to conventional polyurethane adhesives, the adhesive of the present invention can be applied to plastics such as vinyl chloride resin, acrylic resin, ABS resin, polyolefin, polyurethane, fabrics, plastic foam, leather, footwear, bags, etc. or adhesive processing. Used when In particular, when at least one of the adherends is made of vinyl chloride resin, the initial adhesive strength is excellent,
It is an adhesive that can be bonded at high speed, has excellent heat resistance, hot water resistance, and excellent durability.

EXAMPLES Hereinafter, the present invention will be explained in more detail with reference to Examples and Comparative Examples. The polyols, polyisocyanates, and chain extenders that are raw materials for polyurethane used in the examples are indicated using abbreviations, and the relationship between the abbreviations and the compounds is as follows.

J'J lower margin 11 - Examples 1 to 4 and Comparative Examples 1 to 2 Polynisderdiol, diisocyanate and chain extender shown in Table 2 were mixed in a mixed solvent of toluene/methyl ethyl ketone (mixture kik ratio 1/1). was added to give a solid content of 50114i% and reacted to obtain a solution of polyester polyurethane having a hydroxyl group at the molecular end and having the number average molecular weight shown in Table 2.

TMP for 100 layers of the obtained polyurethane solution
-15 parts by weight of TDI adduct (Coronate L) was blended, and then diluted with ethyl acetate to form a 20-tes solution. Remove dirt from the surface of the soft PVC sheet, cut it into small strips, and apply the solution to the strips @129/a! After 10 minutes of oven time, the small piece was stacked on a small piece to which the solution had not been applied, and then pressed with a hand roller 2 to form a test sheet.

This sheet does not come off easily even if you try to peel it off by hand, indicating that high-speed adhesion is possible. After 13 hours, 180 degree peel strength was measured (measurement conditions: tensile speed f2
0 an/min s' Mr 25eta). Further, the bonded test sheet was immersed in hot water at 90° C. for 10 days, and then the adhesive strength was measured under the same measurement conditions as above. 3rd result
Shown in the table. Although the test sheet was left indoors for one year, there was only a slight decrease in adhesiveness and hydrolysis resistance.

Table 3: Effects of the Invention The adhesive of the present invention has excellent initial adhesive strength, can be bonded at high speed, and has excellent hydrolysis resistance, heat resistance, hot water resistance, and durability.

Claims (4)

[Claims] (1) consisting of an α,ω-alkanediol having 8 to 12 carbon atoms alone or this diol and another diol;
A number average molecular weight 1 obtained by reacting a polyester polyol with an average molecular weight of 1,000 to 10,000 synthesized from a mixed glycol containing at least 50% by weight of ω-alkanediol and a dicarboxylic acid with an organic diisocyanate.
An adhesive comprising a polyester polyurethane (A) having 0,000 to 70,000 hydroxyl groups at both ends and a compound (B) having three or more isocyanate groups in the molecule. (2) The adhesive according to claim 1, wherein the α,ω-alkanediol is 1,9-nonanediol. (3) The adhesive according to claim 1, wherein the dicarboxylic acid is azelaic acid or adipic acid. (4) The compounding ratio of the compound (B) having three or more isocyanate groups in the molecule is 5 to 40 parts by weight based on 100 parts by weight of the polyester polyurethane (A), and at least one of the adherends is chlorinated. The adhesive according to claim 1, which is a vinyl resin.