JPH0229106B2 - SETSUCHAKUZAISOSEIBUTSU - Google Patents

Description

[Detailed description of the invention]

The present invention relates to adhesive compositions with improved adhesive properties and heat resistance. Styrene-butadiene-styrene block copolymer (hereinafter referred to as SBS) or styrene-isoprene-styrene block copolymer (hereinafter referred to as SIS)
) has a unique physically cross-linked structure, easy solubility in organic solvents, stress-strain physical properties, high cohesive strength, and high elasticity, making it suitable for hot melt adhesives, coating materials,
It is used as a sealant material, etc. As a result of various studies aimed at improving the performance of the above-mentioned SBS or SIS as an adhesive, the present inventors found that terpene resin and chlorinated polyethylene of a specific molecular weight or chlorinated ethylene-vinyl acetate copolymer were added to the adhesive. The inventors have discovered that a composition containing the following significantly improves adhesive strength and also provides excellent heat resistance, leading to the present invention. That is, the present invention provides (a) SBS or SIS; (b)
It is an adhesive composition containing a terpene resin and (c) a chlorinated ethylene polymer obtained by chlorinating polyethylene or ethylene-vinyl acetate copolymer with a molecular weight of 10,000 to 100,000. The SBS or SIS of the present invention is preferably a block copolymer made by copolymerizing polybutadiene or polyisoprene with a styrene monomer, and usually 70-86% by weight of polybutadiene or polyisoprene and 30-14% by weight of styrene monomer.
A block copolymer obtained by weight% copolymerization having a viscosity of a 10% by weight toluene solution at 20°C of 10 to 100 centipoise is preferably used. Terpene resins are generally used as adhesion aids because of their excellent compatibility with elastomers and their adhesive properties. A solution having a viscosity of 1 to 20 centipoise is preferably used. The chlorinated ethylene-based polymer used in the present invention is preferably a rubber-like material obtained by chlorinating polyethylene or ethylene-vinyl acetate copolymer with a molecular weight of 10,000 to 100,000 while adjusting the raw material to eliminate residual crystals. . Solubility parameter (SP value) of this rubbery substance
The measured value by turbidity titration method is 9.1 to 10.0,
SP value of polystyrene part of SBS or SIS above
8.9, the SP value of the polybutadiene portion was 8.4, and the SP value of the polyisoprene portion was close to 8.1, so their compatibility in the presence of an organic solvent was very good. Note that the SP value referred to here is a measure of compatibility, and when the SP values of the two are similar, it is presumed that the two are compatible. The chlorinated ethylene polymer used in the present invention has a relatively high molecular weight, so it is thermally stable, and has high tensile strength and high elongation. Therefore, when this is blended with SBS or SIS, it is thought to play a role in mitigating the high cohesive force of SBS or SIS, and improve the heat resistance and peeling strength when adhering them. If the raw material molecular weight of the chlorinated ethylene polymer of the present invention is less than 10,000, the rubber elasticity such as tensile strength and elongation rate will be lowered, and furthermore, the thermal stability will be poor, which is not preferable. In addition, if the raw material molecular weight exceeds 100,000, the viscosity of the solution of the obtained chlorinated product will be extremely high, which will impair workability and will also reduce the amount to be added to SBS or SIS, which will not achieve the desired effect of the present invention. I don't get it. The chlorine content of chlorinated ethylene polymers is usually
30 to 50% by weight is preferred. If the amount is less than this range, there will be a problem in solubility in organic solvents, and if it exceeds this range, the heat resistance will decrease, which is not preferable. In addition, if the raw material for the chlorinated ethylene polymer is an ethylene-vinyl acetate copolymer, the vinyl acetate content in the copolymer should be 20% from the viewpoint of rubber elasticity and thermal stability.
Preferably, it is less than % by weight. The ratio of each component of the composition of the present invention is (a) SBS or
SIS 100 parts by weight, (b) terpene resin 30 to 150 parts by weight,
(c) A suitable range of 2 to 30 parts by weight of the chlorinated ethylene polymer. If the terpene resin of component (b) is outside the above range, the adhesive strength will decrease. Further, if the amount of the chlorinated ethylene polymer (c) is less than 2 parts by weight, the improvement effect will be small, and if it exceeds 30 parts by weight, both adhesive strength and heat resistance will decrease, which is not preferable. Various commonly used additives can be added to the composition of the present invention. For example, calcium carbonate, talc,
There are clay, mica, asbestos, alumina, Erosil, etc., and it is also possible to color with inorganic pigments and organic pigments. The composition of the present invention is used by dissolving it in an organic solvent. The organic solvent used is based on an aromatic compound such as benzene, toluene, or xylene, to which a small amount of ketones, alcohols, cellosolves, or hydrocarbon solvents are added. In addition to adhesives, the composition of the present invention can also be used as a primer coating, a sealant, and the like. This will be explained below using examples. In addition, the peel strength and heat resistance temperature in each example are based on the following test method. Peel strength A polyacetal plate with a thickness of 0.4 mm and a size of 20 mm x 150 mm is made into an L-shaped plate with an adhesive part of 20 mm x 40 mm.
Using two sheets of this, apply the composition of each example to the adhesive part, and after volatilizing the solvent, overlap them and let them stand for 30 minutes at room temperature.
Adhesion was achieved by applying a pressure of Kg/cm ² . These two L-shaped plates were pulled up and down at room temperature using a tensile tester, and the 90° peel strength with the adhesive surface was measured. Heat Resistant Temperature Two L-shaped plates were bonded together in the same manner as in the case of peel strength measurement. A constant load of 30g is applied on the top and bottom of these two L-shaped plates in an air oven, and in this state, the temperature is heated at a rate of 1℃/min.The temperature when the adhesive part is peeled off by 15mm is the heat resistance. Shown as temperature. Examples 1 to 6, Comparative Examples 1 to 5 Each composition shown in Table 1 was dissolved in toluene to form a 30% by weight solution. Using these adhesive solutions, the peel strength and heat resistance temperature were measured and are also shown in Table 1. The chlorinated polyethylene used in each example has a molecular weight of 50,000.
SIS is a rubber-like polymer with a chlorine content of 45% by weight that is chlorinated in aqueous suspension using polyethylene as a raw material.
TR1107” (viscosity of 10% by weight toluene solution at 20°C 60 centipoise), terpene resin is Nippon Zeon’s synthetic terpene resin “Quinton A-100”
(softening point 100℃).

[Table] Examples 7 to 8, Comparative Example 6 Chlorine content when polyethylene with a molecular weight of 20,000 is chlorinated in aqueous suspension as chlorinated polyethylene
"Califlex TR1101" manufactured by Ciel Chemical Co., Ltd. is used as SBS using 40% by weight of rubbery chlorinated material.
(Viscosity of 10% by weight toluene solution at 20°C: 80 centipoise); The same procedure as in Examples 1 to 6 was used except that the synthetic terpene resin “Quinton B-170” manufactured by Nippon Zeon Co., Ltd. (softening point: 70°C) was used as the terpene resin. The peel strength and heat resistance temperature were measured, and the results are shown in Table 2.

[Table] Examples 9-10 Instead of chlorinated polyethylene, molecular weight 30000
The procedure was the same as in Examples 1 to 6, except that a rubbery chlorinated product having a chlorine content of 40% by weight, which was obtained by chlorinating an ethylene-vinyl acetate copolymer (vinyl acetate content: 10% by weight) under aqueous suspension as a raw material, was used. We conducted physical property tests using
The results are shown in Table 3.

[Table] Comparative Example 7 Among the chlorinated products with a chlorine content of 35% by weight obtained by chlorinating polyethylene with a molecular weight of 8,000 and 150,000 in aqueous suspension, it is extremely difficult to chlorinate the polyethylene with a molecular weight of 8,000 because the melting point of the raw material polyethylene is low. The obtained chlorinated product was also plastic-like and had a low adhesion-improving effect. In addition, those with a molecular weight of 150,000 had an extremely high toluene solution viscosity, and in order to lower the viscosity to a practical level, the composition content had to be increased to about 5% by weight, making it impractical as an adhesive.

Claims (1)

[Scope of Claims] 1 (a) Styrene-butadiene-styrene block copolymer or styrene-isoprene-styrene block copolymer (b) Terpene resin (c) Polyethylene or ethylene-vinyl acetate copolymer with a molecular weight of 10,000 to 100,000 A chlorinated ethylene polymer obtained by chlorinating a substance. An adhesive composition containing each of the above components (a), (b), and (c).