KR100300360B1 - THERMOPLASTIC Rubber ELASTOMER - Google Patents

Abstract

PURPOSE: Provided is a thermoplastic elastomer, which can be used for elastic bands excellent in tensile strength, tearing strength, elongation, flexibility, elasticity, and restoring force. CONSTITUTION: The thermoplastic elastomer is produced by mixing 40-60wt% of a styrene butadiene styrene block copolymer(SBS-A), 60-40wt% of a styrene butadiene styrene block copolymer(SBS-B), and optionally 1-5wt% of a thermoplastic synthetic resin selected from the group consisting of polypropylene, polyethylene, and polystyrene, wherein the SBS-A contains 30-35wt% of styrene and 70-65wt% of butadiene and has a 300% tensile stress of 40-50Kgf/cm¬2, a tensile strength of 250-285Kgf/cm¬2, an elongation rate of 840-865%, a hardness(Shore-A, 5sec) of 70-78, and the SBS-B contains 37-43wt% of styrene and 63-57wt% of butadiene and has a 300% tensile stress of 60-72Kgf/cm¬2, a tensile strength of 300-340Kgf/cm¬2, an elongation rate of 875-885%, and a hardness of 85-97.

Description

Thermoplastic Rubber Elastomer {THERMOPLASTIC Rubber ELASTOMER}

The present invention relates to a thermoplastic rubber elastomer for producing an elastic band (Band) for tying various packages, small items or hair.

Conventional elastic bands are manufactured using thermoplastic polyurethane (Thermoplastic Polyurethane) as a main raw material, and thus, in case of the bands used for various packaging materials due to the high raw material price, there is a drawback that the packaging cost is expensive, and the band made of the material Tensile strength, rupture strength, tear strength and elongation rate are weak, and thus flexibility, elasticity and resilience are weak, but too hard to handle.

The present invention is a mixture or mixture of two kinds of styrene butadiene styrene copolymer (SBS), which is a styrene block copolymer (SBC), to improve the drawbacks of the conventional elastic band as described above. The thermoplastic rubber elastomer produced by mixing the mixture with the thermoplastic synthetic resin is used as the main material of the elastic band, so that the elastic band made of the material has excellent tensile strength, tear strength and elongation, and thus flexibility, elasticity and resilience. If this is described in detail as an example as follows.

Styrene content is 30-35wt%, Butadiene content is 70-65wt%, 300% tensile stress is 40-50Kgf / cm ² , tensile strength is 250-285Kgf / cm ² , Styrene butadiene styrene block copolymer (hereinafter abbreviated as SBS-A) with elongation of 840 ~ 865% and hardness (Shore-A.5sec) of 70-78 , Content of styrene is 37 ~ 43wt%, content of butadiene is 63 ~ 57wt%, 300% tensile stress is 63 ~ 72Kgf / cm ² , tensile strength is 300 ~ 340Kgf / cm ² , elongation is 875 ~ 885 %, Styrene butadiene styrene block copolymer (hardness of SBS-B) with 85-97% hardness or mixed with only 60-40 wt% of polypropylene (PP), polyethylene (PE), 1 to 5 wt% of any one thermoplastic synthetic resin selected from polystyrene synthetic resins (PS) is mixed and kneaded and stirred at room temperature for 0.5 to 5 minutes. The mixture was left in the air for 30 minutes, kneaded and kneaded again, cooled, and pelletized, granulated or powdered to obtain a thermoplastic rubber elastomer.

Example;

SBS-A 45wt% with styrene content of 32wt%, butadiene content of 68%, 300% tensile stress of 42Kgf / cm ² , tensile strength of 260Kgf / cm ² , elongation of 845% and hardness of 72 the 39wt% content and is a 61wt% butadiene content, 300% tensile stress and 65Kgf / cm ² and the 300Kgf / cm ² tensile strength, elongation at break is 880% and a hardness of from about 3wt% 90 of SBS-B to 55wt% PS After mixing for about 1 minute at room temperature, and left in the air for about 40 minutes, then kneading and cooling again to obtain a pellet obtained by using a band banding device to obtain an elastic band using a conventional ASTM test method The physical properties were tested by the results as shown in Table 1.

Shore A 82 Density (g / cm ³ ) 0.95 Tensile Strength (Kgf / cm ² ) 295 Elongation (%) 870 Abrasion Degree (NBS,%) 140 Tear strength (Kgf / cm) 90 300% tensile stress (Kgf / cm ² ) 56 Melt index at 190 ° C / 5kg (g / 10min) 8

Claims (3)

The content of styrene is 30-35wt%, the content of butadiene is 70-65wt%, the 300% tensile stress is 40-50Kgf / cm ² , the tensile strength is 250-285Kgf / cm ² , 40-60 wt% of styrene butadiene styrene block copolymer (SBS-A) with elongation of 840 ~ 865%, hardness (Shore-A.5sec) of 70-78, and styrene content of 37-43wt%, Styrene with butadiene content of 63 ~ 57wt%, 300% tensile stress of 60 ~ 72Kgf / cm ² , tensile strength of 300 ~ 340Kgf / cm ² , elongation of 875 ~ 885%, hardness of 85 ~ 97 Butadiene styrene block copolymer (SBS-B) 60 ~ 40wt% mixture was kneaded and stirred at room temperature for 0.5 to 5 minutes and then left in the air for 5 to 30 minutes, then kneaded again and cooled to pellet The thermoplastic rubber elastomer characterized in that any one selected from granules or powder. (delete) (New) The thermoplastic rubber elastomer according to claim 1, wherein 1 to 5 wt% of any one thermoplastic synthetic resin selected from polypropylene, polyethylene, and polystyrene synthetic resin is mixed with the mixture of SBS-A and SBS-B.