Asahi Kasei Kabushiki Kaisha

Asahi Kasei Kogyo Kabushiki Kaisha

Jun Yonezawa

Eiji Sasaya

Kiyoo Kato

Takashi Sato

Shinichi Sekikawa

Hiromi Nakafutami

A hydrogenated block copolymer has at least two polymer blocks A each having an aromatic vinyl hydrocarbon compound monomer unit and at least two hydrogenated polymer blocks B each having a hydrogenated butadiene monomer unit. At least 90% of olefinically unsaturated double bonds in the polymer blocks mainly having a butadiene monomer unit before hydrogenation have been hydrogenated. At least one of the locks at the terminal of the hydrogenated block copolymer is the polymer block B. The proportion of the terminal polymer blocks B in the hydrogenated block copolymer is 0.1 wt % to 9.1 wt %. The proportion of the aromatic vinyl hydrocarbon compound in the hydrogenated block copolymer is 25 wt % to 80 wt %. The 1,2-bond content of the polymer blocks having a butadiene monomer unit before hydrogenation averages 60 mol % to 99 mol %. The resulting resin composition improves the balance among the appearance of its molded article, tensile elongation at break and moldability.

Hydrogenated block copolymer

A hydrogenated block copolymer which comprises at least two polymer blocks A each mainly comprising an aromatic vinyl hydrocarbon compound monomer unit and at least two hydrogenated polymer blocks B each mainly comprising a butadiene monomer unit, at least 90% of the olefinically unsaturated double bonds in said polymer block mainly comprising a butadiene monomer unit before hydrogenation having been hydrogenated, wherein at least one of the block at the terminal of the hydrogenated block copolymer is the polymer block B, wherein the proportion of the terminal polymer blocks B in the hydrogenated block copolymer is at least 0.1 wt % but less than 9.1 wt %, wherein the proportion of the aromatic vinyl hydrocarbon compound in the hydrogenated block copolymer exceeds 10 wt % but less than 25 wt %, wherein the 1,2-bond content of the polymer blocks mainly comprising a butadiene monomer unit before hydrogenation is, on average, at least 62 mole % but less than 99 mol %, and wherein the difference &Dgr;Tc (Tc1&minus;Tc2) between the crystallization initiating temperature (Tc1) of the isotactic homopolypropylene and the crystallization initiating temperature (Tc2) of a mixture thereof with the hydrogenated block copolymer is at least 1.5&deg; C.

A hydrogenated block copolymer comprising: two polymer blocks A mainly comprising vinylaromatic hydrocarbon compound monomer units; and one hydrogenated polymer block B mainly comprising butadiene monomer units, in which at least 90% of olefinically unsaturated double bonds contained in a polymer block mainly comprising butadiene monomer units before hydrogenation have been hydrogenated, wherein a bonding vinylaromatic hydrocarbon compound content in the hydrogenated block copolymer is higher than 13 wt % but lower than 25 wt %, a 1,2-bond content in the unhydrogenated polymer block mainly comprising butadiene monomer units is higher than 40 mol % but lower than 60 mol %, and the copolymer has a quantity of heat of crystal fusion (&Dgr;H) smaller than 0.05 J/g, an order-disorder transition temperature of 200&deg; C. or higher, and a melt flow rate (MFR) value, as determined in accordance with JIS K7210 under the conditions of a temperature of 230&deg; C. and a load of 2.16 kg, of from not smaller than 0.1 g/10 min to smaller than 30 g/10 min. By incorporating the copolymer into a polypropylene resin, a composition which is suitable for giving a molded article having an excellent balance among impact resistance, brittle temperature, rigidity, heat distortion resistance, and tensile elongation at break, can be obtained.

Hydrogenated block copolymer and polypropylene resin composition containing the same

A hydrogenated block copolymer comprising: at least two polymer blocks A mainly comprising vinylaromatic hydrocarbon compound monomer units; and at least two polymer blocks B mainly comprising hydrogenated conjugated diene compound monomer units, in which at least 90% of the olefinically unsaturated double bonds contained in the unhydrogenated polymer block mainly comprising the conjugated diene compound monomer units is hydrogenated, wherein at least one of the terminal blocks is a polymer block B, the proportion of the terminal polymer block B in the hydrogenated block copolymer being 0.1% by weight or higher and lower than 9.1% by weight, and wherein the content of the vinylaromatic hydrocarbon compound units in the hydrogenated block copolymer is 12% by weight or higher and lower than 25% by weight. Also disclosed are a resin composition containing the hydrogenated block copolymer, and a molded article of the resin composition.

Growing community of inventors

Yokohama, Japan

Jun Yonezawa