Kuraray Co., Ltd.

Masanari Uno

Koichi Wada

Kazushige Ishiura

Kazuhiko Maekawa

Shiroh Kishii

Hiroshi Hayashihara

Masaki Ikuji

Hajime Kitano

Shigeru Kawahara

Atsushi Itoh

A process for production of a thermoplastic elastomer composition by melt-kneading a mixture in one step to thereby conduct dynamic crosslinking, wherein the mixture comprises a hydrogenated block copolymer (a) which is prepared by hydrogenating a block copolymer comprising a vinyl aromatic polymer block (A) and a conjugated diene polymer block (B) and has number-average molecular weight of 200000 or above and, if necessary, a non-hydrogenated block copolymer (a) comprising a vinyl aromatic polymer block (A) and a conjugated diene polymer block (B), and contains a non-aromatic rubber softening agent (b), a peroxide-crosslinkable olefin resin (c) having a density of 0.94 g/cmor above, a peroxide-decomposable olefin resin (d), an organic peroxide (e), and a crosslinking aid (f), the amount of (b) being 50 to 250 parts by mass per 100 parts by mass of the sum of (a) +(a), the amount of (c) being 2.5 to 50 parts by mass per 100 parts by mass of (a); and the amount of (d) being 0.5 to 10 times that of (c) by mass.

Process for production of thermoplatic elastomer composition

A polymer composition obtainable by subjecting a particular crosslinkable polymer composition to dynamic crosslinking. The crosslinkable polymer composition contains. (a) a block copolymer comprising two or more polymer blocks of a vinyl aromatic compound and one or more (hydrogenated) polymer blocks of a conjugated diene; (b) an olefin copolymer having a density of 0.88 to 0.92 g/cmand obtained through copolymerization of ethylene and an &#x3b1;-olefin having 4 to 12 carbon atoms; (c) a softening agent; and (d) an organic peroxide in respective amounts that satisfy the following relational expressions {circle around (1)} to {circle around (3)}:0.66&#x2266;Wb/Wa&#x2266;4{circle around (1)}0&#x2266;/()&#x2266;0.25{circle around (2)}0.001&#x2266;/()&#x2266;0.01{circle around (3)}wherein Wa, Wb, Wc and Wd represent the respective amounts (by mass) of the components (a), (b), (c) and (d), that are present in the polymer composition prior to the dynamic crosslinking. The polymer composition of the present invention is based on a thermoplastic elastomer that has various improved properties, including moldability, abrasion resistance, scratch resistance, hydrolysis resistance, softness, rubber elasticity, grip, shock absorbance, oil resistance, lightweightness and mechanical strength, and has these properties in a well-balanced manner.

Polymer composition

A thermoplastic polymer composition is provided that includes 100 parts by weight of a block copolymer and/or its hydrogenate having polymer blocks of an aromatic vinyl compound and polymer blocks of a conjugated diene compound, and from 5 to 95 parts by weight of a block copolymer having polymer blocks of an aromatic vinyl compound and/or an olefinic compound and polymer blocks having a constitutional unit derived from a (meth) acrylic compound, a laminate containing a layer of the composition, and a hot-melt adhesive that includes the composition. Because it has good melt adhesiveness, the composition of the invention can firmly adhere in melt to various polar or non-polar materials. Using the composition, it is easy to produce laminates having a layer of the composition and a layer of some other material, through melt shaping or any other melt adhesion techniques. Since the composition of the invention is satisfactorily elastic and flexible, the laminates having a layer of the composition on their surface are flexible and elastic and have a good feel, and, in addition, they are safe because of their shock absorbability and cushionability.

Thermoplastic polymer composition having a thermoplastic elastic polymer

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Ibaraki, Japan

Masanari Uno