Single-layer microporous foil for batteries having shut-off function
AssigneeTreofan Germany GmbH & Co. KG
InventorsBertram Schmitz, Detlef Busch
Life of this patent
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Abstract
Single-layer or multilayer, biaxially oriented, microporous foil having a shut-off function, which comprises propylene homopolymer and propylene block copolymer, polyethylene and β-nucleating agent.
Claims20
A biaxially oriented, single-layer, microporous foil with shut-off function whose microporosity is created by converting β-crystalline polypropylene when the foil is stretched, and which contains propylene homopolymer and propylene block copolymer and β-nucleating agent and polyethylene, wherein the foil has a Gurley value of 50 to 5000 s, an e-modulus in the lengthwise direction of 300-1800 N/mm2, and of 400-3000 N/mm2 in the transverse direction, and wherein after heat treatment of the foil by exposure to a temperature of 130° C. for 5 minutes the foil exhibits a Gurley value of at least 5000 s and wherein the Gurley value after the heat treatment is at least 1000 s higher than before the heat treatment.
A biaxially oriented, single layer, microporous foil having a shut-off function comprising:
- propylene homopolymer;
- propylene block copolymer;
- β-nucleating agent;
- and polyethylene;
- and wherein the foil has a Gurley value of 50 to 5000 s;
- and wherein the shut-off function comprises an increase of at least 1000 s in the Gurley value of the foil after heat treatment at a temperature of 130° C. for 5 minutes.
A battery separator comprising a biaxially oriented single layer microporous foil having a shut-off function comprising:
- propylene homopolymer;
- propylene block copolymer B-nucleating agent;
- and polyethylene;
- and wherein the battery separator has a Gurley value of 50 to 5000 s;
- and wherein the shut-off function comprises an increase of at least 1000 s in the Gurley value of the battery separator after heat treatment of the battery separator at a temperature of 130° C. for 5 minutes.
Dependencies are inferred from the claim text.