PRODUCCION DE REVESTIMIENTOS CON CLORURO DE POLIVINILO POR EL PROCEDIMIENTO DE SINTERIZACION EN CAPA FLUIDIFICADA

摘要

In a process for coating articles by the fluidized bed sintering process using a pulverent thermoplastic composition which is maintained fluidized by passing a current of inert gas, and in which the article is coated by immersing at a temperature above the softening point of the composition, the latter is obtained by adding a plasticizer in the presence of 0,01-5, preferably 0,5-1 part by weight of water per 100 parts of the composition to a pulverulent thermoplast, consisting of at least one vinyl chloride polymer containing 85-100% vinyl chloride units, which is maintained in vigorous motion, and there is also incorporated with the mixture at least one finely divided inert pigment which may be added with or after the plasticizer. Preferably the thermoplast is polyvinyl chloride and/or a vinyl chloride copolymer with an ester of formula CH2=CH-O-CO-R or CH2=CH-CO-OR wherein R is C1-20 alkyl. The following ingredients are specified: (a) comonomers: vinyl formate, acetate, (preferably), propionate, butyrate and stearate, and methyl (preferably), ethyl, propyl, butyl and ethylhexyl acrylates; (b) plasticizers: phthalic, adipic, sebacic or phosphoric esters, e.g. dioctyl adipate and sebacate, tricresyl phosphate and (di) 2-ethylhexyl, octyl, cyclohexyl, hexyl and octadecyl phthalates; (c) pigments: TiO2, ZnO, Al2O3, ZnS, CaCO3, BaSO4, C, Al, and Cu phthalocyanine and 5:51-dichloro-7:71-dimethylthioindigo; (d) vinyl chloride-acetate maleic acid copolymer or sulphurized oils, e.g. to improve the affinity of the thermoplast for metallic surfaces; (e) stabilizer: n-Bu2Sn-(SCH2CO2CH2CHEt2)2.ALSO:Thermoplastic compositions are obtained by adding a plasticizer in the presence of 0,01-5, preferably 0,5-1 part by weight of water per 100 parts of the composition to a pulverulent thermoplast, consisting of at least one vinyl chloride polymer containing 85-100% vinyl chloride units, which is maintained in vigorous motion, and there is also incorporated with the mixture at least one finely divided inert pigment which may be added with or after the plasticizer. Preferably the thermoplast is polyvinyl chloride and/or a vinyl chloride copolymer with an ester of formula CH2=CH-O-CO-R or CH2=CH-CO-OR wherein R is C1-20 alkyl. The following ingredients are specified:- (a) comonomers: vinyl formate, acetate (preferably), propionate, butyrate and stearate, and methyl (preferably), ethyl, propyl, butyl and ethylhexyl acrylates; (b) plasticizers: phthalic, adipic, sebacic or phosphoric esters, e.g. dioctyl adipate and sebacate, tricresyl phosphate and (di) 2-ethylhexyl, octyl, cyclohexyl, hexyl and octadecyl phthalates; (c) pigments: TiO2, ZnO, Al2O3, ZnS, CaCO3, BaSO4, C, Al, and Cu phthalocyanine and 5:51-dichloro-7:71-dimethylthioindigo; (d) vinyl chloride-acetate maleic acid copolymer or sulphurized oils, e.g. to improve the affinity of the thermoplast for metallic surfaces; (e) stabilizer: n-Bu2Sn(SCH2CO2CH2CHEt2)2.