| 摘要 |
Flat paint consists of a dispersion at a particle volume concentration of 20-75%, of non-coalescing elastomeric particles (which may contain up to 40% by wt. of pigment) of 3-150 microns in size, in an elastomeric-film-forming vehicle phase, at least 5% of which is non-volatile elastomer film-forming organic material. The vehicle phase is made up of volatile liquid solvent or dispersant and of non-volatile material. 60-100% by weight of the non-volatile material of the vehicle phase is elastomer film-forming material, the remaining 0-40% being pigment. The total volume of any dispersed pigment in the vehicle phase and the entire volume of all other particles in the paint equal to or greater than 3 microns in size accounts for no more than 85% of the total volume of non-volatile material in the paint. Thickeners or plasticizers may be added to the paint, as we.l as small quantities of rigid particles above 3 microns in size, e.g. glass or metal beads. Elastomeric particles used in the examples are of polyurethane, e.g. water-cured dispersed droplets of a waxy-solid isocyanate-terminated polyester prepolymer with chrome oxide and phthalocyanine green pigments; or ground particles of polyurethane formed by curing an isocyanate - terminated polyester prepolymer with 1,4-butanediol, and containing, if desired, carbon black. Vehicle phases used in the examples are a dispersion in xylol and Cellosolve acetate of a waxy-solid 4,41-diphenylmethane di-isocyanate terminated polyester prepolymer and 1,4-butanediol; an aqueous dispersion of a copolymer of 60% methyl and 40% ethyl acrylate; a plastisol of finely-divided polyvinyl chloride in dioctyl phthalate and naphtha. Example 5 uses a dispersion in cyclohexanone of elastomeric polyurethane from polyester and diphenyl diisocyanate, with aliphatic glycol as a curing agent. |
