Beta-crystalline form of isotactic polypropylene and method for forming the same
OwnerGuan-yi Shi, Jing-yun Zhang +1inventors
InventorsGuan-yi Shi, Jing-yun Zhang, Hesheng Jing
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Abstract
This invention relates to obtaining beta crystalline Phase isotactic polypropylene with high purity and thermal stability simply by melt-crystallization in the presence of a two component beta nucleating agent. The two component beta-nucleating agent is formed by mixing 0.0001-1 weight % of dibasic acid with 0.001-1 weight % oxide, hydroxide or acid salt of a Group IIA metal. Such beta phase polypropylene can be used for the production of high impact strength molding extrusion shapes, microporous film and microporous hollow fiber.
Claims5
A method for producing a beta-crystalline polypropylene material having a K value of 0.85-0.93, which comprises mixing a two-component beta-nucleating agent consisting of an organic dibasic acid and an oxide, a hydroxide, or an inorganic salt of a Group IIA metal, with polypropylene or an ethylene/propylene block copolymer to form a mixture having 0.0001-5% by weight of the organic dibasic acid and 0.001-5% by weight of the oxide, hydroxide, or inorganic acid salt of the Group IIA metal, melting the mixture, and then allowing crystallization of said polymer from the melt in the presence of the beta-nucleating agent.
A method for producing a beta-crystalline polypropylene material having a K value of 0.85-0.93, which comprises mixing an organic dibasic acid with polypropylene or an ethylene-propylene block copolymer containing an oxide, a hydroxide, or an inorganic acid salt of a group IIA metal to form a mixture having 0.0001-5% by weight of said organic dibasic acid and 0.001-5% by weight of said oxide, hydroxide or acid salt of a Group IIA metal;
- melting the mixture;
- and then allowing crystallization of the said polymer from the melt in the presence of said acid and said Group IIA metal oxide, hydroxide, or acid salt.
Dependencies are inferred from the claim text.