KR910006391B1 - Composition of polyester adhersives - Google Patents

Abstract

The hot-melt adhesive composition is composed of (1) diacid component containing 60-90 mol.% terephthalic acid, 5-35 mol.% isophthalic acid, 5-35 mol.% dimeric acid of carbon number 36 with 99% purity, and (2) diol component containing 5-40 mol.% ethylene glycol and 60-95 mol.% hexamethylene glycol. The total content of isophthalic acid and dimeric acid in the composition is 10-40 mol.%. The adhesive is used in the adhesion of polyester films, fibers and shoes.

Description

Hot Melt Copolymerized Polyester Adhesive Composition

The present invention relates to a hot melt polyester adhesive. More specifically, the present invention relates to a heat-melting copolymerized polyester adhesive composition composed of terephthalic acid, isophthalic acid and high purity diacid as a diacid component, and composed of ethylene glycol and hexamethylene glycol as an el wool component.

In recent years, the hot melt adhesive has been rapidly increasing in demand due to its pollution-free, energy-saving and excellent workability.

Conventional polyester-based hot melt adhesives are mostly composed of terephthalic acid, isophthalic acid, fat having 30 or less carbon atoms, or dicarboxylic acid, as acid components. For example, Japanese Patent Publication No. 34-3238 (95 to 65% by weight of terephthalic acid, 5 to 35% by weight of isophthalic acid), U.S. Patent Nos. 3,090,772 and 3,212,115 are mainly composed of terephthalic acid and isophthalic acid. , No. 3,232,813 (terephthalic acid 70 to 90 mol%, isophthalic acid 10 to 30 mol%), and examples of using polyesters composed of aromatic dicarboxylic acid containing terephthalic acid as an acid component and aliphatic dicarboxylic acid having 30 or less carbon atoms US Patent Publication Nos. 2,623,303, 2,765,250, 2,765,251, Japanese Patent Application Publication Nos. 50-130830, US Patent Publication No. 3,421,944, and the like.

Because of the high content of aromatic dicarboxylic acid and low carbon number of dicarboxylic acid in such conventional polyester acid components, there is a drawback that the melt viscosity is high and the softening point of the resin is high and the adhesion to the adherend is remarkably inferior. In order to lower the melt viscosity, there is a method of increasing the content of aliphatic dicarboxylic acid, but if the content of aliphatic dicarboxylic acid is increased, the melting point is sharply lowered and the adhesive strength is also lowered, so that the content of aliphatic dicarboxylic acid cannot be too high.

Conventional copolyester having a high content of aromatic dicarboxylic acid as an acid component has high crystallinity and crystallization rate because of high rigidity and symmetry of molecules. Heat-melt adhesives using such a copolyester as an active ingredient are highly likely to undergo crystallization immediately after application, and thus the adhesive may not sufficiently penetrate between the adherends and thus may not exhibit adhesive force.

In order to avoid this phenomenon, there is a method of applying at a temperature higher than the operating temperature of the hot melt adhesive (softening point +20 to 40 ° C) or higher (softening point + 40 ° C or more), but in this case, pyrolysis of adhesive components due to high temperature However, there is a drawback that must be accompanied by the risk of thermal decomposition of the adherend.

The present inventors have conducted various studies to overcome the above-mentioned drawbacks, and have thus obtained a novel copolyester composition capable of lowering the melt viscosity without lowering the adhesive strength and completing the present invention. That is, the heat-melting polyester of the present invention comprises (1) 60 to 90 mol% of terephthalic acid, (2) 5 to 35 mol% of isophthalic acid and (3) 5 to 35 mol% of isophthalic acid (3) 5 to 35 mol% of high purity dimer acid containing 98% or more of dimer acid having 36 carbon atoms, and as diol component, (4) 5 to 40 mol% of ethylene glycol and (5) 60 to 95 mol It consists of% hexamethylene glycol, It is characterized by the mole% which combined (2) and (3) in the said diacid component comprised 10-40 mol% in all the diacid phase parts.

Particularly, since dimer acid having 36 carbon atoms among the diacid components constituting the polyester of the present invention has a purity of 98% or more, it is possible to produce a polymer having a high degree of polymerization unlike a dimer acid having a low purity (90% or less of dimer acid). Do. In the embodiment of the present invention, even when a small amount was added using the brand PRIPOL 1009 of Unichema, it was confirmed that the melt viscosity of the copolyester is significantly lowered, thereby greatly improving workability.

The copolymerized polyester has an extreme viscosity (using a mixed solvent of phenol / 1.1.2,2-tetra chloroethane = 6/4 weight ratio, measured at 25 ° C.) of 0.3 dl / g or more, especially 0.3 to 1.5 dl / g. It is preferable.

If the intrinsic viscosity is 0.3 dl / g or less, since the molecular weight of the copolyester is low, the cohesive force is low, and the adhesive force, heat resistance, strength, etc. as the adhesive are lowered, which is not preferable. The softening point is preferably 180 ° C or lower, particularly 60 to 150 ° C. The preparation of the copolyesters according to the invention is in accordance with conventional methods.

For example, there is a method of polymerizing terephthalic acid or its ester-forming derivative, isophthalic acid or its ester-forming derivative, having its high purity dimer acid or its ester-forming derivative having 36 carbon atoms after direct esterification or transesterification with the diol component. It is well known that any catalyst, stabilizer, modifier and additive can be used. In addition, as the diacid component for producing the copolymerized polyester, terephthalic acid or its ester-forming derivative isophthalic acid or its ester-forming derivative can be used.

In preparing the polyester of the present invention, it is possible to change the order of input of each of the diacid component and diol component, which is possible according to a conventional method. It is also well known that in the direct esterification reaction and transesterification reaction, the reaction may proceed by adding the diacid component and the next component in the presence of the direct esterification of the diacid component and the diol component or the transesterification reaction product.

The hot melt polyester adhesive composition of the present invention has a softening point of 60 to 150 ° C. and an intrinsic viscosity range of 0.3 to 1.5 dl / g. The polyester of the present invention has a high adhesive strength and a low melt viscosity unlike conventional heat-melt polyester adhesives, and is excellent in adhesion to adherends.

In particular, the polyester of the present invention is processed into a fiber, film, sheet, powder, pellet, block, rod (Rod) can be used for a wide range of applications, such as fiber bonding, polyester film bonding, shoe bonding. The process of processing the above polyester onto fibers, films, sheets, powders, pallets, rods is possible by known conventional methods.

In the following Examples and Comparative Examples show a method for producing a hot melt co-polyester of the present invention. Unless otherwise specified, units are based on mole percent. The measuring method of the described physical property of the present invention is based on the following method.

* Extreme viscosity of the polymer (dl / g)

Measured at 25 ° C. using a solution of phenol / 1,1,2,2-tetrachloroethanol in a 6/4 weight ratio

* Adhesion to adherend

After melt-coating polyma on a 1 mm thick stainless steel plate at 210 ° C. to 100 μm, it is cooled to room temperature, and 100 eyes (10cm × 10cm) like a checkerboard are made with an NK cutter. Stick the cello tape on this surface and leave for 1 minute to remove the cello tape. The adhesion was evaluated by the number of checkerboard eyes attached to the cello tape.

* Shear Adhesion (㎏ / ㎠)

It measured based on JISK 6850-72. That is, a film-like adhesive is placed between two test pieces (1.6 mm x 1 cm x 10 cm), and thermocompression-bonding is carried out at 230 ° C. for 5 kg / cm 2 for 2 minutes (the thickness of the adhesive layer after thermo-compression is 100 µ), using a tensile tester. Tensile strength at the time of pulling two test pieces horizontally with respect to an adhesive piece at the speed | rate of 20 mm / min at 23 degreeC, respectively, was measured.

* Carboxyl number (meq / ㎏)

Measure by titration with KOH.

Example 1

Terephthalic acid, isophthalic acid, high-purity dimer acid (using Unichema trade name PRIPOL 1009), ethylene glycol, and hexamethylene glycol were polymerized in a conventional manner to make 60 mole percent terephthalic acid, 30 mole percent isophthalic acid, and dimer acid 10 in all the diacid components. A polyester composed of 40 mol% ethylene glycol hexamethylene glycol 62 mol% in mol% and the total diol components was synthesized. The intrinsic viscosity of the resulting polyester was 0.650 dl / g carboxyl number was 17 meq / kg.

[Example 2-6, Comparative Example 1-3]

It carried out by the same method as Example (1), and obtained the copolyester as each polymer composition was as Table.

TABLE 1

The symbol in the above table means the following.

TPA: Terephthalic Acid

IPA: isophthalic acid

DMA: Dimer acid

SA: Sebacic Acid

AA: adipic acid

HG: Hexamethylene glycol

EG: ethylene glycol

Claims (2)

In preparing a polyester composition with a diacid component and a diol component, 5 containing at least 98% of 60 to 90 mol% of terephthalic acid, 5 to 35 mol% of isophthalic acid and 36 carbon atoms of dimer acid as the diacid component. A hot melt copolymer polyester adhesive composition containing from 35 to 35 mole percent high purity dimer acid and containing 5 to 40 mole percent ethylene glycol and 60 to 95 mole percent hexamethylene glycol as the diol component. . The hot melt copolymer polyester adhesive composition according to claim 1, wherein the total content of isophthalic acid and dimer acid is 10 to 40 mol% in the diacid component.