| 摘要 |
A solution of an organic acid ester of cellulose in a halogen-containing organic solvent contains a minor proportion, e.g. 0.005 to 0.5% by weight of an organotin salt of a carboxylic acid as a corrosion inhibitor. The carboxylic acid may be either a monocarboxylic acid, e.g. acetic, butyric, caproic, lauric, polmitic, oleic or behenic acid, or a dicarboxylic acid, e.g. maleic acid or fumaric acid. The inhibitor may be an alkyltin maleate wherein the alkyl group contains about 2 to 20 carbon atoms, e.g. dibutyltin maleate. Organotin salts of mixed maleic acid and a monocarboxylic acid are also suitable and may have the formula <FORM:1039938/C3/1> wherein R is an alkyl, aryl or aralkyl group and R1 is an alkyl radical. The organotin inhibitor is preferably used in conjunction with a lower alkyl amine nitrite corrosion inhibitor, e.g. 0.001 to 0.1% of 2-hydroxy-propylamine nitrite. In the production of artificial filaments by dry spinning solutions of organic acid esters of cellulose the preferred solvents are chlorine substituted lower alkanes such as methylene chloride and ethylene dichloride. When methylene chloride is used it may contain up to 20% by weight of a volatile alcohol, the percentage being based on the combined weights of methylene chloride and alcohol. The cellulose ester may be the acetate, propionate, butyrate, acetate-propionate and acetate-butyrate, especially cellulose triacetate. The presence of the organotin inhibitor prevents and reduces the corrosion of the stainless steel spinnerets used in dry spinning and the amine nitrite inhibitor if present enhances the inhibition of corrosion in a synergistic manner.
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