JPS61247745A - Thermoplastic resin composition for sole of footwear - Google Patents

Abstract

PURPOSE:To provide the title resin compsn. having excellent anti-slipping properties and suitable as the sole of footwear, by mixing an ethylene/vinyl chloride resin having a high degree of polymn., a partially crosslinked acrylonitrile/ butadiene copolymer and a phthalate plasticizer in a specified weight ratio. CONSTITUTION:100 pts.wt. ethylene/vinyl chloride resin having a degree of polymn. of 1800-2800, 5-30 pts. wt. partially crosslinked acrylonitrile/butadiene copolymer and 120-150 pts. wt. phthalate plasticizer (e.g. dioctyl phthalate or dibutyl phthalate) are mixed to obtain the desired thermoplastic resin compsn. for the sole of footwear. By using the ethylene/vinyl chloride copolymer resin having a high degree of polymn., a large quantity of the plasticizer can be added, whereby a resin compsn. which is soft, has excellent elasticity and is hardly slippable, can be obtd. without lowering characteristics.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a thermoplastic resin composition for soles of footwear having excellent anti-slip properties.

(Prior art) Conventionally, thermoplastic resins, plasticizers and other lubricants, stabilizers,
2. Description of the Related Art Injection molded footwear, in which soles are formed by injection molding using a thermoplastic resin composition mixed with fillers, pigments, etc., is well known. In particular, straight polyvinyl chloride compounds are easily processable, inexpensive, and have excellent abrasion resistance, weather resistance, etc., and are widely used.

(The problem that the invention is trying to solve) However,
Traditionally used injection molded footwear soles made from thermoplastic resins have the disadvantage of poor cold resistance and slip resistance, which can lead to slips and falls on snow or ice while walking, especially in cold areas during the winter. It also caused danger and was a major drawback as a footwear sole.

(Means for Solving the Problems) In the present invention, by conducting various studies on thermoplastic resin compositions, we have solved the above-mentioned drawbacks, and in particular, we have created a thermoplastic resin composition suitable for footwear soles that eliminates slipperiness. This is what I got.

That is, the present invention uses 100 parts by weight of a high polymerization degree ethylene/vinyl chloride resin with a resin polymerization degree of 1800 to 2800, 5 to 30 parts by weight of a partially crosslinked acrylonitrile butadiene copolymer, and 120 to 150 parts by weight of a phthalate ester bile agent. The present invention relates to a thermoplastic resin composition for footwear soles comprising: As the plasticizer, it is essential to use a heptatalic acid ester plasticizer, but a small amount of a polyester-based, naphthene-based, or paraffin-based plasticizer such as NBR or other synthetic rubber may also be used in combination.

These plasticizers are used in an amount of 120 to 150 parts by weight per 100 parts by weight of the thermoplastic polymer. Examples of phthalate ester plasticizers include dioctyl phthalate, dimethyl phthalate, diethyl phthalate, diisobutyl phthalate, dibutyl heptathalate, cyheptyl phthalate, dinonyl heptathalate, diindecyl phthalate, ditridecyl phthalate, dicyclohexyl heptathalate, etc. be. Common additives added to thermoplastic polymer mixtures such as lubricants, stabilizers, fillers, blowing agents, pigments, etc. can be added in appropriate amounts to the composition of the present invention as well as to conventional compositions. . About 1 to 35 parts by weight are suitable.

(Function) Conventional thermoplastic resin compositions for injection molded footwear soles have a relatively low degree of polymerization of thermoplastic polymers, especially polyvinyl chloride (950 to 1800), so they have poor plasticizer absorption ability. The plasticizer mixed with this is also low, and the thermoplastic polymer is
00 parts by weight, it was possible to add only a small amount of 80 to 115 parts by weight. Therefore, even if a large amount of plasticizer is added in an attempt to soften the hardness of the thermoplastic resin composition, the polyvinyl chloride polymer cannot absorb the plasticizer completely, resulting in ooting and bleeding, and the physical properties are also reduced. It's something you end up doing. In the present invention, the resin polymerization degree is 1800.
By using an ethylene/vinyl chloride copolymer resin with a high polymerization degree of ~2800, it is possible to add a large amount of plasticizer (120 to 150 parts by weight per 100 parts by weight) without deteriorating the physical properties. A resin composition that is soft, highly elastic, and non-slip can be obtained. Furthermore, since the ethylene/vinyl chloride copolymer resin itself has good flow, a partially crosslinked acrylonitrile butadiene copolymer having rubber elasticity (which has poor flow) can be added to improve the rubber elasticity.

(Effects) The footwear soles made of the thermoplastic resin composition for footwear soles of the present invention are resistant to slipping even on snow and ice, and can be worn on concrete, vinyl tiles, iron plates, decorative plywood, etc., unlike rubber soles. Equivalent slip resistance can be obtained.

In addition, since a large amount of plasticizer can be added, the specific gravity of the resin composition itself is reduced, and the weight of the sole is 10 to 15% lower than that of conventional products.
The weight is also reduced. Furthermore, if necessary, a blowing agent such as azodicarbonamide, P, P'-oxybis-(benzenesulfonylhydraded), etc.
By adding 5 parts by weight of L5 to make the shoe sole a foamed material, the weight can be further reduced by 10 to 15%, and a shoe sole with good rubber elasticity and compression set can be obtained. (The specific gravity of the polyvinyl chloride polymer is about 1.4 and the specific gravity of the plasticizer is about 0.92 to 1.12.

) As described above, the thermoplastic resin composition according to the present invention has lower hardness than conventional compositions, and has improved elasticity.
In particular, it has a high slip resistance, making it difficult to slip, making it an extremely excellent material for footwear soles.

(Example of the present invention) Examples of the present invention will be shown below.

In Comparative Examples 1 to 3 and Examples 1 to 6, each composition was stirred and mixed under the same conditions, heated and formed into a shoe sole using an injection molding machine, and a test piece was extracted from the sole to measure the physical properties. I did it.

As a result of measuring the physical properties of Examples 1 to 6 of the present invention and Comparative Example 1 of the current composition, in the case of Examples 1 to 6, the hardness was lower than that of Comparative Example I.
K is lower than that, and a softer product is obtained. Furthermore, the slip resistance values were all higher than those of Comparative Example 1, indicating that the composition of the present invention is extremely less slippery than the conventional composition. In addition, the rebound elasticity value is also larger than that of Comparative Example 1, indicating that a product with high elasticity similar to rubber can be obtained.

The degree of processing is as good as in Comparative Example 1. Moreover, Comparative Example 2 is inferior to those of Examples in terms of slip resistance, rebound, etc., and is also poor in workability. Comparative Example 3 is inferior in workability compared to the Example.

Claims (1)

[Claims] (1) A footwear sole consisting of 100 parts by weight of a high polymerization degree ethylene/vinyl chloride resin with a resin polymerization degree of 1800 to 2800, 5 to 30 parts by weight of a partially crosslinked acrylonitrile butadiene copolymer, and 120 to 150 parts by weight of a phthalate ester plasticizer. thermoplastic resin composition for use.