| 摘要 |
1303120 Increasing the molecular weight of polymers INTERNATIONAL BUSINESS MACHINES CORP 29 July 1970 [2 Sept 1969] 36665/70 Heading C3P [Also in Division G2] A process for increasing the molecular weight of a photosensitive polymeric ester of cinnamic acid, e.g. polyvinyl cinnamate (prepared by esterifying polyvinyl alcohol with cinnamoyl chloride), comprises dissolving the polymeric ester in an inert solvent and treating the polymeric ester with a base at a temperature which is sufficiently low to avoid significant saponification of the polymeric ester. Solvents specified are cyclohexanone, methylene chloride, chlorobenzene and tetrahydrofuran. The base used may be inorganic or organic, e.g. sodium or potassium hydroxide, ammonium hydroxide, sodium carbonate, n-butylamine or triethylamine; the base is suitably used in the form of an aqueous solution. In illustrated procedures the treatment is effected at room temperature. The photosensitive polymers can be exposed, e.g. to U.V. light in the presence of a thiazolinetype photoinitiator, to produce photoresists. |
