POLYPROPYLENE-BASED RESIN COMPOSITION AND FOAM SHEET

摘要

Provided is a polypropylene-based resin composition which gives uniform and fine cells and from which a foamed sheet and thermoform excellent in appearance, thermoformability, impact resistance, lightness, stiffness, heat resistance, heat insulating properties, oil resistance and the like can be produced. A polypropylene-based resin composition comprising (X) 5 to 99% by weight of a polypropylene resin having a structure with long chain branches, and (Y) 1 to 95% by weight of a propylene-based block copolymer produced by sequential polymerization, which block copolymer comprises (Y-1) a propylene (co)polymer and (Y-2) a propylene-ethylene copolymer, said resin (X) having properties (X-i) to (X-iv) and said block copolymer (Y) having properties (Y-i) to (Y-v), and the like.

主权项

1. A polypropylene-based resin composition comprising:
(X) 5 to 99% by weight of a polypropylene resin having a structure with long chain branches, and (Y) 1 to 95% by weight of a propylene-based block copolymer produced by sequential polymerization, which comprises:
(Y-1) a propylene (co)polymer, and(Y-2) a propylene-ethylene copolymer, wherein the resin (X) has the following properties (X-i) to (X-iv):
(X-i): MFR of 0.1 to 30.0 g/10 minutes,(X-ii): a molecular weight distribution Mw/Mn of 3.0 to 10.0 measured by GPC and Mz/Mw of 2.5 to 10.0,(X-iii): a melt tension (MT) (unit: g) satisfying the relationship:
log(MT)≧−0.9×log(MFR)+0.7, orMT≧15,(X-iv): a content of p-xylene soluble components (CXS) at 25° C. of less than 5% by weight based on a total amount of the resin (X), and the block copolymer (Y) has the following properties (Y-i) to (Y-v):
(Y-i): ratios of the amounts of the (Y-1) and (Y-2) of 50 to 99% by weight and 1 to 50% by weight, respectively, with the proviso that each ratio is calculated based on a total of 100% by weight of the block copolymer (Y),(Y-ii): MFR of the block copolymer (Y) of 0.1 to 200.0 g/10 minutes,(Y-iii): melting point of the block copolymer (Y) of more than 155° C.,(Y-iv): an ethylene content of the (Y-2) of 11.0 to 38.0% by weight, with the proviso that the ethylene content is calculated based on a total of 100% by weight of monomers constructing the (Y-2), and(Y-v): an intrinsic viscosity [η] (unit: dl/g) of the (Y-2) measured at 135° C. in decalin of 5.3 or more.