| 摘要 |
813,846. Laminates; coated cellulosic films. UNION CARBIDE CORPORATION. April 4, 1956 [April 18, 1955], No. 10246/56. Class 140. [Also in Group XXXVI] A two- or multi-layer film suitable as an electrode separator in a dry cell electric battery comprises a layer of a water-soluble non-fibrous alkyl cellulose ether or hydroxy- or carboxysubstituted alkyl cellulose ether or salt of a carboxy-substituted alkyl cellulose ether adhered by a partially hydrated alkyl cellulose ether or derivative as above to a layer of waterinsoluble alkali-soluble non-fibrous alkyl cellulose ether or an insolubilized film of a watersoluble alkyl cellulose ether. Typical suitable water-soluble non-fibrous cellulose ethers or derivatives are methyl or ethyl cellulose, hydroxyethyl or hydroxypropyl cellulose, and sodium carboxymethyl cellulose. The waterinsoluble ether layer may be formed by treatment of the water-soluble ether with citric or tannic acids or a melamine-formaldehyde resin as in Specification 603,927 [Group XXXVI] in the mix used for casting, and the water-soluble cellulose ether may be either (a) applied as a preformed film when the adhering material may be a preformed layer, paste, or dough of partially hydrated water-soluble cellulose ether or formed in situ on the water-soluble film by the application to either or both of the layers to be joined of an organic liquid which does not react with them, e.g. lower alkyl alcohols and ketones, containing up to 4 per cent water; or (b) spread as an aqueous self-adhering paste or dough. One of the two layers may contain an identifying dye. The film is dried e.g. at 130‹ C. under tension. If mercuric chloride is incorporated in the water-soluble layer for amalgamation with the zinc can of the battery which it contacts, drying should be effected at not more than 40‹ C. If desired, water-soluble cellulose ether layers may be applied to both sides of the waterinsoluble layer. |
