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 comprising a structure with long chain branches, and (Y) 1 to 95% by weight of a sequentially polymerized propylene-based block copolymer wherein said resin (Y) comprises:
(Y-1) a propylene (co)polymer, and(Y-2) a propylene-ethylene copolymer, and wherein said resin (X) has: (X-i): a melt flow rate (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) where
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 the total amount of said resin (X), and wherein said block copolymer (Y) has: (Y-i): a weight ratio of 50 to 99% of (Y-1) and 1 to 50% of (Y-2) where said ratio is calculated based on the total weight of said block copolymer (Y) regarded as 100% by weight, and (Y-ii): an MFR of said block copolymer (Y) of 0.1 to 200.0 g/10 minutes, (Y-iii): a melting point of said block copolymer (Y) of more than 155° C., (Y-iv): an ethylene content of said (Y-2) of 11.0% or more and less than 60.0% by weight, wherein said ethylene content is calculated based on the total weight of monomers comprising (Y-2) regarded as 100% by weight, and (Y-v): the intrinsic viscosity [η] of said (Y-2) measured at 135° C. in decalin is
greater than or equal to 5.3 dl/g when said ethylene content of said (Y-2) is 11.0% or more and 38.0% or less by weight, orgreater than or equal to 7.3 dl/g when said ethylene content of said (Y-2) is greater than 38.0% and less than 60.0% by weight.