JPH0449877B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a polyester hot melt adhesive with improved adhesive strength. Polyester-based hot melt adhesives are widely used mainly for textile fabrics. However, it still has poor adhesion to molded materials such as synthetic resin sheets, films, leather, and foams that are widely used in household electrical appliances, cabinets, automobile interiors, and house interiors. However, it cannot be said that the adhesive strength is sufficient for practical use, and there is an urgent need for the development of polyester-based hot melt adhesives with improved adhesive strength for such uses. However, the inventors of the present invention have conducted extensive research to solve this problem, and as a result (1) 40 mol% or more of the acid component is terephthalic acid, and 70 mol% or more of the glycol component is ethylene glycol, 1,4-butanediol, Consists of at least one type of 1.6-hexanediol, and has an intrinsic viscosity of
0.5 or more, 60-95% by weight of crystalline polyester resin with a melting point of 60-220°C (2) Phthalate ester compound with a melting point of 25-150°C,
The present invention was completed by discovering that a hot melt adhesive comprising 40 to 5% by weight of at least one selected from fatty acid ester compounds, sulfonamide compounds, and bifnyl compounds can achieve the object. The polyester resin (1) in the present invention must contain 40 mol% or more of terephthalic acid (including its derivatives) as an acid component. That is, the molar ratio of terephthalic acid and other dicarboxylic acids is 100:0 ~
It's 40:60. If the content of other dicarboxylic acids exceeds 60 mol%, the molecular cohesive force and adhesive force will decrease, making it impossible to achieve the purpose. In addition, as for the glycol component, 70 mol% or more is ethylene glycol, 1.4-butanediol, 1.6-
Must be at least one type of hexanediol. Of course, there is no problem in using other polyhydric alcohols in combination, but if they are used in excess of 30 mol%, the crystallinity of the polyester resin will be impaired, resulting in a decrease in adhesive strength. The intrinsic viscosity of the resin (phenol/1.1.2.2-tetrachloroethane (3/2) mixed liquid, measured at 30℃) is
It must be 0.5 or more; if it is less than 0.5, the resin will be brittle and the adhesive strength will be low. Further, it is necessary that the melting point is 60 to 220°C, and if it is higher than 220°C, the adhesive force will be low, and if it is lower than 60°C, the cohesive force will decrease, resulting in a decrease in adhesive force, which is not preferable. Other dicarboxylic acids other than terephthalic acid for the polyester resin in the present invention include malonic acid,
Examples of diols other than ethylene glycol, 1,4-butanediol, and 1,6-hexanediol include succinic acid, adipic acid, phthalic anhydride, phthalic acid, isophthalic acid, sebacic acid, and azelaic acid. Examples include 1,3-propanediol, 1,4-cyclohexanedimethanol, neopentyl glycol, 1,2-propylene glycol, 1,3-butylene glycol, 1,2-butylene glycol, diethylene glycol, and triethylene glycol. In the resin of the present invention, the diol component is used in a ratio of 1.1 to 2.5 moles per mole of the dicarboxylic acid component, and this is combined with a polycondensation catalyst such as zinc acetate or other esterification reaction catalyst and antimony trioxide. Alternatively, it is produced using an alkyl ester of titanic acid as a catalyst for esterification reaction and polycondensation. The reaction conditions are to react at 180 to 220℃ under normal pressure for 120 to 240 minutes, and once the produced water or alcohol has been distilled off, the system is reduced to an absolute pressure of 100 to 250 mmHg and the esterification reaction is completed in 60 to 120 minutes. . Next, the system was brought to a high vacuum of 1 mmHg or less, and the temperature was rapidly raised to 240-260℃, and at this temperature
Heating is performed for 180 minutes to obtain a polyester resin having the desired intrinsic viscosity. It is essential for the adhesive of the present invention to use at least one selected from phthalate ester compounds, fatty acid ester compounds, sulfonamide compounds, and bifnyl compounds together with the above resin.
Among the above compounds, the melting point is preferably 25 to 150℃.
It is necessary to use a compound having a temperature of 35 to 120°C, that is, a compound that is solid at room temperature. Not only are the above compounds liquid at room temperature, but even solids with a melting point of 25°C or below are mixed, resulting in disadvantages in terms of handling, such as the powder properties of the adhesive, such as blocking properties and fluidity. Not only does this become noticeable, but also the adhesive strength to the base material decreases. Further, even if the melting point is in the range of 25 to 150°C, if a compound other than the above-mentioned compound is used, an adhesive having remarkable adhesive strength as in the present invention cannot be obtained. Typical phthalate ester compounds include dilauryl phthalate, dicyclohexyl phthalate, diphenyl phthalate, disellosolve phthalate, ethyl phthalyl ethyl glycoler, and tetrahydrophthalic acid propylene oxide adduct. The fatty acid in the fatty acid ester compound refers to one having about 4 to 20 carbon atoms. The acids include palmitic acid, lauric acid, stearic acid,
Examples include succinic acid, sebacic acid, octylic acid, adipic acid, and the like. As the ester, an alkyl ester is generally used, but it is of course possible to use not only an alkyl group but also a substituted alkyl group, a cyclic ester, a phenyl group, and the like. Representative examples of such fatty acid ester compounds include methyl cellosolve palmitate, glycerol monolaurate, glycerol monostearate, dibenzyl succinate, dimethyl sebacate, and dibenzyl sebacate. Sulfonamide compounds include O-toluenesulfonamide, P-toluenesulfonamide,
Examples include N-ethyl-P-toluenesulfonamide. Examples of biphenyl compounds include O-nitrobuphenyl hexachloride biphenyl and the like. Of course, the above compounds are not limited to these. The blending ratio of the polyester resin and the compound is 60 to 95% by weight, preferably 70 to 90% by weight, and the latter is preferably 70 to 90% by weight.
40-5% by weight, preferably 30-10% by weight. Anything outside this range will lead to a decrease in adhesive strength. The adhesive used in the present invention may have a
About 5% of inert inorganic powder may be added. Such powders include titanium dioxide, aluminum oxide, tank, gypsum, china clay, bennite, calcium carbonate, silicic acid, and the like. Thus, the adhesive of the present invention is suitably used as an adhesive for synthetic resin films, sheets, and molded articles. Among such synthetic resins, vinyl chloride resin, polyester resin, polyurethane resin,
It has particularly excellent adhesion to films and sheets made of ABS resin, polystyrene resin, polycarbonate, etc. In addition, it also has extremely superior adhesive strength to metals, paper, wood, etc., compared to conventional polyester hot melt adhesives. The adhesive can be used as a hot melt adhesive in any desired form such as powder, tape, film, or sheet for the above-mentioned purposes. That is, the adhesive is sandwiched between base materials of the same or different types and heated and softened using a hot roller, hot press, iron, etc., or the adhesive is melted and melt coated on the base material using a commercially available applicator. Glue. Next, the present invention will be explained in more detail by giving examples. However, "parts" or "%" in the examples are based on weight unless otherwise specified. Manufacture of adhesive: 70 parts of a polyester resin (intrinsic viscosity: 0.84, melting point: 132°C) consisting of 0.6 mol of terephthalic acid, 0.4 mol of adipic acid, 0.4 mol of ethylene glycol, and 0.6 mol of 1,4-butanediol, and dicyclohexyl phthalate (melting point: 65°C). ) in a Brabender at 170°C, and then taken out and cut into chips with a sheet cutter. This will be referred to as Adhesive 1. Furthermore, in place of dicyclohexyl phthalate in adhesive 1, diphenyl phthalate (melting point 44°C,
(Blending amount 5%) (Adhesive 2), Tetrahydrophthalic acid propylene oxide adduct (Melting point 37℃, Blending amount
10%) (adhesive 3), disellosolve phthalate (melting point 31°C, blending amount 10%) (adhesive 4), methyl cellosolve palmitate (melting point 48°C, blending amount 15%) (adhesive 5), glycerol mono Laurate (melting point 63
℃, blending amount 25%) (adhesive 6), glycerol monostearate (melting point 81℃, blending amount 20%) (adhesive 7), P-toluenesulfonamide (melting point 105℃,
Blending amount: 20%) (Adhesive 8), N-ethyl-P-toluenesulfonamide (melting point: 59°C, Blending amount: 15%)
(Adhesive 9), O-nitro biphenyl (melting point 37℃,
An adhesive was manufactured using a compounded amount of 15% (adhesive 10). Incidentally, the above-mentioned compounding amount represents the compounding amount of each compound with respect to the entire adhesive. 0.72 mol of terephthalic acid in place of the polyester resin used in adhesives 1, 2, 5, 8, and 10;
Polyester resin consisting of 0.28 mol of adipic acid, 0.34 mol of ethylene glycol, and 0.66 mol of 1,6-hexanediol (intrinsic viscosity: 0.82, melting point 143°C)
The adhesive was manufactured so that the blended amount was 85% of the total adhesive. Glue 1′ of each adhesive in turn,
2′, 5′, 8′, 10′. Also, in place of the polyester resin used in Adhesives 1, 6, and 9, 0.9 mol of terephthalic acid, 0.1 mol of isophthalic acid, and 0.8 mol of 1,6-hexanediol were used.
mol, polyester resin consisting of 0.2 mol of diethylene glycol (intrinsic viscosity: 0.75, melting point 115°C)
The adhesive was manufactured so that the blended amount was 90% of the total adhesive. Glue 1″ of each adhesive in turn,
6″, 9″. Adhesives 1 to 10, 1', 2', 5', 8', 10' and
The following experiments were conducted using 1", 6", and 9". Experiment 1 (Adhesion of vinyl chloride resin films to each other) The above adhesive was melted to a thickness of 30μ on a vinyl chloride resin film (thickness 150μ). After coating, the same vinyl chloride resin film was placed on top of this and pressure bonded (150℃ x 1Kg/cm ² x 3 seconds), and the adhesive force was measured.However, the adhesive force was measured at 100mm using an autograph. /min
It was determined by T-peeling a 25 mm wide sample. Experiment 2 (Adhesion of ABS resin sheets to each other) Adhesion was carried out in the same manner as in Experiment 1, except that an ABS resin sheet (thickness: 2 mm) was used instead of the vinyl chloride resin film in Experiment 1, and the shear adhesive strength was measured. Experiment 3 (Adhesion between different substrates) The same vinyl chloride resin film used in Experiment 1 was melt-coated with adhesive to a thickness of 30μ, and polycarbonate was adhered to it in the same manner as in Experiment 1. The adhesive force was measured. Experiments 4 to 6 (adhesion of metal, wood, and paper) PVC resin film and iron plate (thickness 0.3 mm)
(Experiment 4), plywood (5mm thick) (Experiment 5), and cardboard (2mm thick) (Experiment 6), which were then hot roll glued from one side at 150℃ x Kg/cm ² x 20m/sec. The adhesive force was measured (amount of adhesive used: 40 g/cm ² ). The measurement results of the adhesive strength of Experiments 1 to 6 are summarized in Table 1. As a symmetrical example, the compounding amount of the compound added in adhesives 1, 3, 5, 8, and 10 was 1% (symmetrical example 1),
Experiments 1 to 6 were conducted by changing the ratio to 40% (symmetrical example 2). Adhesives 1〓, 3〓, 5〓, 8〓, 10〓, 1〓, 3 in order for each control example.
Let 〓, 5〓, 8〓, 10〓. Further, a similar test was conducted using dioctyl phthalate (liquid at room temperature) in place of diphenyl phthalate in Adhesive 2 (Comparative Example 3). The measurement results of adhesive strength in Control Examples 1 to 3 were
They are summarized in the table.

[Table] (Note) The unit in Experiment 2 is Kg/cm ²
, everything else is in Kg/cm.
Ru. Note that all values in Experiment 5.6 are for material failure.

[Table] (Note) Units are the same as in Table 1.

Claims (1)

[Scope of Claims] 1. 40 mol% or more of the acid component is terephthalic acid, 70 mol% or more of the glycol component is at least one of ethylene glycol, 1.4-butanediol, and 1.6-hexanediol, and has an intrinsic viscosity of 0.5 or more. , crystalline polyester resin 60 with melting point 60~220℃
~95% by weight, 2. Phthalate ester compound with a melting point of 25-150°C,
A hot melt adhesive comprising 40 to 5% by weight of at least one selected from fatty acid ester compounds, sulfonamide compounds, and biphenyl compounds (excluding those for textile fabrics).