| 摘要 |
Aq. dispersion contains polymer granules with or of a polymer with epoxy gps. and dihydroxy gps. derived from the hydrolysis of epoxy gps. The polymer pref. contains recurring units of the formulae -CHR2 CR2-A-B (in which B is (1) -CH-CH2 and (2) -CH(OH)-CH2OH). R1 is H or a short-chain (1-2C)alkyl gp. R2 is R1 or halogen. A is a divalent organic gp., pref. alkylene, (alkylene)oxyalkylene (di)carbonyloxyalkylene, carbonitrilo(oxyalkylene) or carbonyl-amino). The claims cover the use of the dispersion as photographic coating compsn. It can be used in both insensitive and photosensitive layers. Unlike other aq. dispersions, it can be mixed with hydrophillic colloids (gelatin) and treated with hydrophobic (photographic) substances. If organic solvents are present, they do not cause agglomeration of the polymer. The dispersion is stable and does not lead to staining through interaction with a colour developer or discolouration of the developed image. There is no redn. in speed or increase in fog and the coated photographic base has better dimensional stability and curling properties and much better scratch and pressure resistance flexibility and drying. |
