Microporous plastic member such as a battery separator and process for making same
A process for producing a microporous plastic member useful as a battery separator comprises the following operations: forming a coherent dough by mixing a vinyl chloride resin with a plasticizing amount of a first solvent and with finely divided particles of a filler which contains volatilizable releasable constituent by heating and which shrinks substantially and irreversibly upon release of the volatilizable constituent, an example of which is hydrated silica; forming the solvent-containing dough into a shaped member; extracting the first solvent from the member before any substantial evaporation of solvent occurs by contacting it with a second solvent in a liquid bath at a temperature substantially below the boiling point of any liquid present, the second solvent being one which is capable of dissolving the first solvent without dissolving the resin and the filler, thereby deplasticizing the member by extractively removing the first solvent from the member; and thereafter heating the member at an elevated temperature but below the softening point of the resin until the filler is shrunk within the member by release of its volatilizable content. 10 claims.
- Assignee:
- Aktiebolaget Tudor
- Patent Number(s):
- US 4153760
- OSTI ID:
- 5692166
- Country of Publication:
- United States
- Language:
- English
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Microporous film battery separator
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Related Subjects
250903* -- Energy Storage-- Batteries-- Materials
Components
& Auxiliaries
ADSORBENTS
BATTERY SEPARATORS
CHEMICAL PREPARATION
CHLORINATED ALIPHATIC HYDROCARBONS
FABRICATION
HALOGENATED ALIPHATIC HYDROCARBONS
KETONES
ORGANIC CHLORINE COMPOUNDS
ORGANIC COMPOUNDS
ORGANIC HALOGEN COMPOUNDS
ORGANIC POLYMERS
PETROCHEMICALS
PETROLEUM PRODUCTS
PLASTICS
POLYMERS
POLYVINYLS
PVC
SILICA GEL
SOLVENTS
SYNTHESIS