摘要:
IT HAS BEEN FOUND THAT WHEN FLEXIBLE WEBS (SUCH AS THOSE OF POLYMERIC FILMS HAVING GOOD DIMEMSIONABLE STABILITY AND SUBSTANTIALLY NO SOLUBILITY IN THE DOPE SYSTEMS BEING USED) ARE UTILIZED AS TEMPORARY SUPPORTS UPON WHICH CELLULOSE ESTER DOPE SOLUTIONS ARE CAST IN THE MANUFACTURE OF "REVERSE OSMOSIS" MEMBRANES, THE RESULTING GELLED MEMBRANES ARE ORDINARILY DIFFICULT TO REMOVE FROM THE FLEXIBLE WEB. DRAMATICALLY ENHANCED RELEASABILITY OF THE GELLED MEMBRANES FROM SUCH FLEXIBLE SUPPORTS RESULTS IF THE SURFACE OF THE FLEXIBLE SUPPORT IS FIRST MADE VERY HYDROPHYLIC.
摘要:
Coating compositions, suitable for use as a subbing layer on oriented polyester sheeting in making photographic films (see Groups VIII and XX) comprise (by weight):-0,25 to 1% gelatin. 0,5 to 6% terpolymer of (a) 80-90% vinyl or vinylidene chloride, (b) 9-19% vinyl ester of a C2-4 saturated fatty acid or a C1-4 alkyl acrylate, and (c) 0,5 to 3% of an alpha p unsaturated alpha-beta dicarboxylic acid or anhydride. 5 to 30% phenol or a mono-C1-4 alkyl substituted phenol. 0 to 0,03% gelatin hardener (e.g. chromium chloride hexahydrate). Balance C1-3 alkane dichloride, up to 25% of which may be replaced by methanol. Unsaturated dicarboxylic acids specified are itaconic and maleic. An optional second subbing layer coating composition specified consists of 0,6 to 1,75% gelatin, 0,06 to 0,15% acid dispersing agent therefor (e.g. acetic), 0,1 to 0,8% of the same terpolymer, 1 to 3,5% water, 0 to 0,03% hardener, 60 to 80% alkane dichloride and 38,24 to 13,77% methanol. In one of the specific examples (4) the coating composition of the invention used for the first subbing layer also contains 1% titanium dioxide and 0,5% ground glass. Specification 777,215 is referred to.