| 摘要 |
<p>A terpolymer for use in coating a film having a base of regenerated cellulose is produced by polymerizing a monomer mixture consisting of 0.5 to 25% by weight of alpha, beta-unsaturated aldehyde, 10 to 94.5% by weight of vinylidene chloride and 5.0 to 89.5% by weight of a different vinyl or vinylidene monomer copolymerizable therewith. The aldehyde may be acrolein or methacrolein. The vinyl or vinylidene monomer may be acrylonitrile and/or methylacrylate. The copolymer may be prepared by emulsion or suspension polymerization in an aqueous medium, or solution polymerization in a mixture of methyl ethyl ketone, methyl isobutyl ketone and toluene. Initiators that may be employed are potassium persulphate, azobisisobutyronitrile, or sodium metabisulphite. Emulsifying or dispersing agents, e.g. sodium dodecyl benzene sulphate may also be present.ALSO:Moistureproof film having a base of regenerated cellulose is produced by polymerizing a monomer mixture consisting of 0.5 to 25% by weight of alpha, beta-unsaturated aldehyde, 10 to 94.5% by weight of vinylidene chloride and 5.0 to 89.5% by weight of a different vinyl o vinylidene monomer copolymerizable therewith, coating the thus obtained copolymer on the base film and heat-treating the coated film at elevated temperatures. The aldheyde may be acrolein and alpha- or beta-substituted acrolein in which the substituents are alkyl groups or halogens, e.g. crotonaldehyde, methacrolein and alphachloro-acrolein. The vinyl or vinylidene monomer may be one or more of acrylonitrile, methacrylonitrile, alkyl-, cycloalkyl- or phenyl esters of acrylic or methacrylic acid, examples of which are given, vinyl acetate, vinyl chloride and alkyl vinyl ether, and may be present in an amount from 5 to 90% by weight based on the total weight of the mixture. The heat treatment may be carried out between 80 and 150 DEG C. The copolymer may be prepared by emulsion or suspension polymerization in an aqueous medium, solution polymerization in organic medium, precipitation polymerization, and bulk polymerization without use of any polymerization medium. The polymerization may be carried out in an atmosphere of nitrogen. Initiators that may be employed include hydrogen peroxide, persulphates, perborates, azo compounds, organo metallic compounds, organic peroxides and hydroperoxides, and organic peracids. Activating agents specified are salts of heavy metals, sulphites, acid sulphites and like substances commonly employed as initiators in conventional redox polymerization. Emulsifying or dispersing agents, and chain transfer reagents may also be present.</p> |
