| 摘要 |
Terpolymers comprise 80 to 93 weight per cent vinylidene chloride, from 4.5 to 19.5 weight per cent of acrylonitrile, alkyl esters of acrylic and methacrylic acids having from 1 to 18 carbon atoms in the alkyl group, or vinyl chloride, and from 0.5 to 2.5 weight per cent of glycidyl acrylate or methacrylate, or a non-carboxylic acid salt of vinyl benzyl amine or 2-aminoethyl acrylate. The non-carboxylic acid should be an acid capable of neutralizing the basicity of the pendant groups from the monomer preferably to form oil-soluble salts. Examples of suitable non-carboxylic acids are the mineral acids such as sulphuric, nitric, hydrochloric acids, the oil-soluble organic sulphonic acids such as methane-, benzene,-toluene-, 2-naphthalene sulphonic acids. The copolymerization may be conducted in aqueous emulsions containing a catalyst, e.g. potassium persulphate and conventional emulsifying and/ or dispersing agents. Alternatively the monomeric components may be polymerized in bulk without added diluent, or in organic solvent reaction media. In Example 1 a charge comprising water, potassium persulphate, diisopropyldixanthogen, dioctyl ester of sodium sulphosuccinic acid, acrylonitrile, vinylidene chloride, glycidyl acrylate is placed in a glass reaction vessel and polymerized at 60 DEG C. for 16 hours, thereafter freeze coagulated, thawed, filtered and dried. The terpolymer is dissolved in tetrahydrofuran to form a lacquer.ALSO:Moistureproof, heat sealable, flexible, transparent films are produced by coating regenerated cellulose film with a coating composition comprising a terpolymer obtained by polymerizing a mixture of 80 to 93 weight per cent of vinylidene chloride, 4.5 to 19.5 weight per cent of a copolymerizable monoethylenically unsaturated monomer, and 0.5 to 2.5 weight weight per cent of glycidyl acrylate or methacrylate or a non-carboxylic acid salt of vinylbenzyl amine or 2-aminoethyl methacrylate as anchoring agent. The copolymerizable monoethylenically unsaturated monomers may be acrylonitrile, alkyl esters of acrylic and methacrylic acids having from 1 to 18 carbon atoms in the alkyl group, or vinyl chloride. The monomers may be copolymerized in aqueous emulsions containing a catalyst e.g. potassium persulphate and emulsifying and/or dispersing agents; in bulk without added diluent; or in appropriate organic solvent reaction media. The anchoring agent may be mixed with the remaining monomers in an aqueous medium containing the catalyst, or the monomeric mixture can be premixed and added to the aqueous medium containing the catalyst. The terpolymer may be coated on the regenerated cellulose film by any suitable technique and may be applied as an organic solvent solution e.g. in tetrahydrofuran or from aqueous emulsion. The coating may be applied using a thin, stainless steel wire-wound film casting rod. The acids used to form the salts of vinylbenzyl amine or 2-aminoethyl methacrylate are those capable of neutralizing the basicity of the basic group pendant from the monomer. It is preferred that the acid and basic groups form an oil-soluble, neutralized entity. The acids may be mineral acids such as sulphuric, nitric and hydrochloric acids, and the oil-soluble organic sulphonic acids, such as methane sulphonic acid, benzene sulphonic acid, toluene sulphonic acid and 2-naphthalene sulphonic acid. The coated film may be conditioned at say 50% relative humidity at 25 DEG C. |
