| 摘要 |
<p>832,664. Filling leather. FARBENFABRIKEN BAYER A.G. May 7, 1958 [May 17, 1957], No. 14671/58. Class 76. Leather is filled by treating it with an aqueous dispersion of finely-divided fillers in the presence of water-soluble dispersing-agents precipitable by acids, said agents being obtained by condensation of one or more carbamides (such as dicyandiamide) with formaldehyde in a non- acidic medium containing a water-soluble salt of an organic sulphonic acid (such as the sodium salt of dinaphthyl methane disulphonic acid) and finishing the treating process by adjusting to an acid pH value. The addition of acid reagent for adjustment may be dispensed with if the leather possesses at the end of the treatment a high acidity. The products to be used as dispersing agents may be obtained as in Specification 827,473, or in U.S.A. Specifications 2,737,504 and 2,884,403. The fillers used include finely-divided silicic acid, aluminium oxide, carbon black, iron oxide pigments, china clay, talc, and other specified inorganic fillers, or organic fillers such as polyvinyl chloride, cellulose, starch and its ethers and other specified organic fillers.</p> |
