| 摘要 |
1400861 Powdered coating materials GROW CHEMICAL CORP 21 Aug 1972 [5 Oct 1971] 38916/72 Heading C4A Powdered coating material is made by finely dividing a liquid coating material comprising a solvent portion, a film forming portion and a pigment in the presence of a coagulating liquid, in which the solvent portion is soluble and the film forming portion and the pigment are insoluble, and diluting the droplets formed with the coagulating liquid so as to precipitate the non-solvent portion of the liquid coating material in powder form. The process can be carried out by adding the liquid coating material to the coagulating liquid, adding the coagulating liquid to the liquid coating material or by adding to the liquid coating material an amount of coagulating liquid which is less than the amount necessary for coagulation and then finely dividing and diluting the mixture in the presence of a further amount of coagulating liquid. The powder precipitated can be screened and oversize and/or undersize particles redissolved and recycled. In examples a liquid paint containing carbon pigment and acrylic ester resin dissolved in acetone and naphtha is precipitated with water and a liquid paint containing titanium dioxide, lampblack, talc and thermoplastic resin dissolved in acetone is precipitated with water.
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