Polyolefin-based composite resin composition having high strength and low linear expansion

A polyolefin-based composite resin composition having high strength and low linear thermal expansion comprising:

• (i) 30-80% by weight of a crystalline ethylene-propylene copolymer:
• (ii) 5-40% by weight of an ethylene-□-olefin copolymer:
• (iii) 5-40% by weight of an inorganic fortifier;
• and
• (iv) additives, wherein said ethylene-α-olefin copolymer contains 20-50% by weight of propylene and 5-20 % by weight of ethylene-propylene copolymer rubber having a melt index of 0.1-5 g/10 mm (230° C., 2.16 kg).

A polyolefin-based composite resin composition having high strength and low linear thermal expansion comprising:

• (i) 30-80% by weight of a crystalline ethylene-propylene copolymer;
• (ii) 5-40% by weight of an ethylene-α-olefin copolymer;
• (iii) 5-40% by weight of an inorganic fortifier;
• and
• (iv) additives, wherein said ethylene-α-olefin copolymer contains 20-50% by weight of octene and 5-20% by weight of ethylene-octene copolymer rubber having a melt index of 0.1-15 g/10 mm (230° C., 2.16 kg).

A polyolefin-based composite resin composition having high strength and low linear thermal expansion comprising:

• between about 45% and about 55% by weight of a crystalline ethylene-propylene copolymer, wherein at least 30% by weight of the composition comprises a crystalline ethylene-propylene copolymer with a melt index of between about 40 and about 60;
• between about 20 and about 30% by weight of an ethylene-α-olefin copolymer, wherein at least 5-20% by weight of the ethylene-α-olefin is an ethylene-propylene copolymer containing 20-50% by weight of propylene and 5-20% by weight of ethylene-propylene copolymer rubber having a melt index of about 0.5 to about 4 g/10 mm (230° C., 2.16 kg), or contains 20-50% by weight of octene and 5-20% by weight of ethylene-octene copolymer rubber having a melt index of about 3 to about 15 g10 mm (230° C., 2.16 kg), or a mixture thereof between about 20 and about 30% by weight of an inorganic fortifier with an aspect ratio of at least 6 and with an average particle size of between about 1 and about 8 microns;
• and
• between about 0.2 and about 3% of additives.

A polyolefin-based composite resin composition having high strength and low linear thermal expansion comprising:

• between about 40% and about 60% by weight of a crystalline ethylene-propylene copolymer manufactured by polymerization of monomers in the presence of a combinatory catalyst, a Ziegler-Natta type catalyst, and an alkylaluminium compound or under a catalyst containing a titanium compound or a magnesium compound and containing between about 18 and about 34% of ethylene-propylene rubber, wherein the degree of crystallinity is between about 20 and about 30% and the melt index of the crystalline ethylene-propylene copolymer of the present invention is preferred to be between about 5 and about 60 g/10 mm (210° C., 2.16 kg);
• between about 15 and about 35% by weight of an ethylene-α-olefin copolymer wherein the α-olefin is selected from the group consisting of 1-propylene, 1-butene, 1-hexene, 1-octene, or mixtures thereof, wherein the ethylene-α-olefin copolymer is polymerized from monomers using a Ziegler-Natta catalyst, a vanadium-based catalyst, a chromium-based catalyst, or mixtures thereof, and comprise between 20 and 50% by weight of the α-olefin, and at least 5% by weight of ethylene-α-olefin copolymer rubber;
• between about 15and about 30% by weight of an inorganic fortifier with an aspect ratio of at least 6 and with an average particle size of between about 1 and about 8 microns;
• and
• between about 0.2 and about 3% of additives.