Thermoplastic elastomer composition and method for producing same

Abstract

The present invention is a thermoplastic elastomer composition which is obtained by dynamically crosslinking an ethylene / Alpha-olefin / non-conjugated polyene copolymer (A), a polyolefin resin (B), 1-200 parts by mass of a softening agent (C) per 100 parts by mass of the total of the copolymer (A) and the resin (B), and a crosslinking agent (D) with use of a batch mixer under conditions satisfying the following conditions (1)-(4). (1) 50 <=P1 <=300 (In this connection, P1 is defined by formula (i). P1 = Gamma ave. * Log(t1) (i) (In formula (i), t1 represents the retention time (sec) after the introduction of the crosslinking agent (D), and Gamma ave. represents the average rate (sec-1) of the shear rates Gamma at t1.)) (2) 900 <=P2 <=1450 (In this connection, P2 is defined by formula (ii). P2 = (Tave. + 273) * Log(t1) (ii) (In formula (ii), Tave. represents the average resin temperature (DEG C) after the introduction of the crosslinking agent (D), and t1 represents the retention time (sec) after the introduction of the crosslinking agent (D).)) (3) -2.5 <=P3 <=1.5 (In this connection, P3 is defined by formula (iii). P3 = Log(t1 / t2) (iii) (In formula (iii), t1 represents the retention time (sec) after the introduction of the crosslinking agent (D), and t2 represents the time (sec) necessary for the residual amount of the crosslinking agent (D) to be 1 ppm or less of the introduced amount thereof at the average resin temperature Tave. after the introduction of the crosslinking agent (D).)) (4) The crosslinking agent (D) is introduced into a batch mixer after the introduction of the ethylene / Alpha-olefin / non-conjugated polyene copolymer (A), the polyolefin resin (B) and the softening agent (C). A thermoplastic elastomer composition according to the present invention is able to produce a molded body that has excellent appearance and excellent mechanical properties such as rubber elasticity, while being capable of increasing the melt density and the extrusion amount, thereby improving the productivity.

Description

technical field [0001] The present invention relates to a thermoplastic elastomer composition and a method for producing the same. More specifically, the present invention relates to a thermoplastic elastomer composition and a method for producing the thermoplastic elastomer composition capable of efficiently producing molded articles having excellent mechanical properties such as rubber elasticity and appearance. Background technique [0002] A thermoplastic elastomer composition obtained by dynamically heat-treating rubber and polyolefin resin in the presence of a crosslinking agent. Usually, the rubber component constitutes a soft segment (soft phase) that imparts flexibility, and the polyolefin resin constitutes a A hard segment (hard phase) that provides a pseudo-crosslinked structure has a structure in which a phase formed of a soft segment (hereinafter referred to as an island phase) is dispersed in a phase formed of a hard segment (hereinafter referred to as a sea pha...

AI Technical Summary

Problems solved by technology

However, when a twin-screw extruder is used, the dispersion of the island phase may not be sufficient, and thus a composition having excellent mechanical properties and appearance cannot be obtained in many cases

For example, in Patent Documents 1 to 4, the production method of a thermoplastic elastomer composition using a twin-screw extruder is disclosed, but the dispersibility of the island phase in the obtained thermoplastic elastomer composition is not necessarily satisfactory, and it is desired to develop A method for producing a thermoplastic elastomer composition capable of further improving the dispersibility of the island phase and producing a molded article having more excellent mechanical properties and appearance

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