Organic flatting agents and method of preparation
AssigneePPG Industries, Inc.
InventorsMarco Wismer, Karl F. Schimmel, Rodger G. Temple
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Abstract
Solid organic inert flatting agents are prepared by reacting urea or phenol and formaldehyde in a basic aqueous medium to provide a prepolymer solution, then blending the prepolymer in the presence of a protective colloid-forming material, subsequently acidifying the basic prepolymer solution so that particles are formed and precipitated in the presence of a colloid-forming material, as spheroidal beads, and finally collecting and, if desired, drying the urea or phenol formaldehyde particulate beads. These beads have a high flatting efficiency and may be incorporated in resinous vehicles to provide compositions that produce low glass coatings of desirable properties.
Claims4
A coating composition comprising a film forming resinous vehicle and incorporated therein agglomerated particulate beads having a gross particle size of from about 1 to about 50 microns in an amount sufficient to have a flatting effect on films of said filmforming material, wherein said beads consist essentially of urea or phenol and formaldehyde prepared by the method comprising:
- A. reacting a urea or a phenol and a formaldehyde, wherein the molar ratio of the urea to the formaldehyde is from about 1:1 to about 3:0.5 and wherein the molar ratio of the phenol to the formaldehyde is from about 1:1 to about 1:3, in a basic aqueous medium to form a prepolymer;
- B. blending said prepolymer with a hydroxyfunctional protective colloid-forming material;
- C. polymerizing the prepolymer by acidifying the mixture thus formed under agitation, thereby forming particulate beads and agglomerating said beads to a gross particle size of from about 1 micron to about 50 microns;
- and
- D. collecting said urea or phenol-formaldehyde particulate beads.
Dependencies are inferred from the claim text.