abstract |
An expandable resin composition comprising: (A) 100 parts by weight of HDPE (high density polyethylene) having a DSC melting point of about 127 to about 136 degrees C.; a density of 0.945 to 0.967 gram per cubic centimeter; and a melt flow rate of about 0.1 to about 10 grams per 10 minutes, and for each 100 parts by weight of component (A), (B) about 2 to about 50 parts by weight of polypropylene having a DSC melting point of at least about 130 degrees C.; (C) about 50 to about 200 parts by weight of an ethylene/alpha-olefin copolymer, prepared with a metallocene catalyst, having a DSC melting point of about 98 to about 121 degrees C.; a density of 0.900 to 0.935 gram per cubic centimeter; and a melt flow rate of about 0.5 to about 3 grams per 10 minutes; (D) about 0.1 to about 5 parts by weight of a polysiloxane-polyether block copolymer having the following formula:R3-Si-O-R2(SiO)m-RX(SiO)n-SiR3 wherein each R is independently a monovalent alkyl, alkoxy, hydroxy, aryl, or aralkyl group; X has the formula: -(CH2)p-(O)q-(CtH2tO)s-R'; R' is the same as R above and (CtH2tO)s is a radical group of ethylene oxide or propylene oxide polymer; and m is 5 to 300; n is 2 to 20; p is 0 or 2; q is 0 or 1; t is 2 or 3; and s is 5 to 100; and (E) about 0.02 to about 5 parts by weight of a nucleating agent selected from the group consisting of azodicarbonamide, talc, and mixtures thereof. |