| abstract |
1,169,227. Cross-linked cellulose ethers. BEXFORD Ltd. 9 Nov., 1967 [17 Nov., 1966; 15 May, 1967], Nos. 51573/66 and 22441/67. Heading C3A. [Also in Division G2] Hydroxypropyl- and hydroxypropyl methyl cellulose ethers are crosslinked by reaction with one of the following cross-linking agents preferably in acid conditions: (i) water-soluble cationic polyamide resins; (ii) urea formaldehyde condensators; (iii) hexamethylolmelamine, dimethylol urea, dimethylol ethylene urea, dimethylol-ethyl triezene, tetra (hydroxymethyl) phosphonium chloride, di- and trimethylol phenyl, di-methylol p-cresol, trimethylolmelamine; (iv) certain carboxylic acid anhydrides and dianhydrides; (v) glyoxal, glutardialdehyde, sucindialdehyde and aldehyde-starch; (vi) titanium or zirconium tetraalkoxides; and (vii) tannic acid. Cross-linking may occur by drying the cellulose ether/crosslinking agent solution or by heating the solution. The cellulose ethers are used in photographic materials (see Division G2). |