Patent GB-937365-A (GB)
Title: Improvements in and relating to pigments
Inventor: BYBALSKI JACK NORBERT
IPC: C09C3/08
Filed: 1960-05-24
Abstract: Pigment particles are uniformly coated with from 0.05 to 5% by weight (based on the weight of dry pigment) of a mixture containing from 0,25 to 10 parts by weight of a quaternary ammonium compound having the formula <FORM:0937365/III/1> (wherein R is an aliphatic hydrocarbon radical containing from 8 to 22 carbon atoms, R1 is a lower alkyl radical having from 1 to 3 carbon atoms, and X is a halogen) per part by weight of a tertiary aliphatic amine having the formula <FORM:0937365/III/2> (wherein R is as above, and x and y are integers whose sum is from 2 to 10).  The coated pigment particles may be produced by adding the quaternary ammonium compound-tertiary amine mixture, in which the amine is present as a salt, to an aqueous suspension of the pigment, adding, with agitation, a dilute solution of an alkali metal hydroxide to convert the tertiary amine salt to the free amine, and separating the coated pigment particles from the aqueous phase.  Alternatively, the quaternary ammonium compound-tertiary amine mixture may be incorporated in organophilic media, such as oils, oleoresinous materials, rubber and plastics, and a dry pigment or water-wet pigment cake added. Pigments mentioned include iron blue, chrome yellow, chrome orange, chrome green, zinc chromate, calcium carbonate, calcium silicate, ultramarine, titanium dioxide, black iron oxide, red iron oxide, zinc oxide, lithopone, white lead, azo-type toners, aluminium hydroxide cake, carbon black and zinc sulphide-containing pigments.  Examples describe the use of the coated pigments in natural and synthetic rubber mixes, polyvinyl chloride plastisols and linseed oil varnish vehicles.ALSO:Pigment particles are uniformly coated with from 0,05 to 5% by weight (based on the weight of dry pigment) of a mixture containing from 0,25 to 10 parts by weight of a quaternary ammonium compound having the formula <FORM:0937365/IV(a)/1> (wherein R is an aliphatic hydrocarbon radical containing from 8 to 22 carbon atoms, R1 is a lower alkyl radical having from 1 to 3 carbon atoms, and X is a halogen) per part by weight of a tertiary aliphatic amine having the formula <FORM:0937365/IV(a)/2> (wherein R is as above, and x and y are integers whose sum is from 2 to 10).  The coated pigment particles may be produced by adding the quaternary ammonium compound-tertiary amine mixture, in which the amine is present as a salt, to an aqueous suspension of the pigment, adding, with agitation, a dilute solution of an alkali metal hydroxide to convert the tertiary amine salt to the free amine, and separating the coated pigment particles from the aqueous phase.  Alternatively, the quaternary ammonium compound-tertiary amine mixture may be incorporated in organophilic media, such as oils, oleoresinous materials, rubber and plastics, and a dry pigment or water-wet pigment cake added. Pigments mentioned include iron blue, chrome yellow, chrome orange, chrome green, zinc chromate, calcium carbonate, calcium silicate, ultramarine, titanium dioxide, black iron oxide, red iron oxide, zinc oxide, lithopone, white lead, azo-type toners, aluminium hydroxide cake, carbon black and zinc sulphide-containing pigments.  Examples describe the use of the coated pigments in natural and synthetic rubber mixes and polyvinyl chloride plastisols.