Patent GB-790477-A (GB)
Title: Improved process of making oil-in-water polyester resin emulsion pigment printing colour concentrates
IPC: D06P1/44
Filed: 1954-04-30
Abstract: An oil-in-water emulsion colour concentrate is prepared by dispersing a pigment in water with the aid of a fatty alcohol sulphate, and emulsifying into the dispersion, while maintaining the pigment deflocculated, and in the presence of a protective colloid, a water-insoluble resinous polyester containing residues of a polyunsaturated monocarboxylic acid derived from a natural fat or oil.  Preferably the polyester is used as a solution.  The fatty alcohol sulphate, e.g. sodium lauryl sulphate, acts as emulsifying agent for the resin as well as dispersing agent for the pigment. Suitable resins referred to are condensation products of bisphenol and epichlorohydrin esterified with fatty acids as specified above; styrenated fatty acid-modified alkyds; styrenated oils; oil-modified alkyds; and pentaerythritol-glycerine mixed esters of maleic anhydride-modified fatty acids.  A number of commercially available resins are mentioned under their Trade names. Particularly suitable resins are those called E-polyesters in Specification 774,078, [Group IV (a)].  Organic solvent soluble urea- or melamine-formaldehyde resins may be included in the oil phase of the emulsions.  A number of emulsifying agents which may be used in addition to the fatty alcohol sulphates, and a number of protective colloids are specifically mentioned in the Specification.  Preferred kind of pigments are phthalocyanine pigments, insoluble azo pigments, vat pigments and carbon blacks. Preferably the dispersing action of the fatty alcohol sulphate is aided by addition of a sodium alkyl naphthalene sulphonate. Protective colloids, e.g. casein or methylcellulose, may also be added to the pigment dispersion.  The resin may be slowly added to the pigment dispersion, or the pigment dispersion may be slowly stirred into the resin.  In the second case a water-in-oil emulsion is first formed and inversion then takes place.  In either case the colour concentrates may be homogenized, e.g. by colloid milling.  It is also possible to feed the two phases simultaneously in the right proportions to the emulsifying equipment. In a typical example: (A) a phthalocyamine blue presscaro is mixed with sodium lauryl sulphate and sodum alkyl naphthalene sulphonate in a high-speed turbine mixer, with addition of an aqueous mixture containing ammonium caseinate, further sodium lauryl sulphate, preservatives, an anti-foaming agent, methyl cellulose, ammonia and a sequestrating agent.  The final dispersion contains 66.97 per cent water.  (B) A 50 per cent xylol solution of E-polyester B as described in Specification 774,078, [Group IV (a)], is mixed with a 50 per cent solution in butylalcohol-xylol of a butyl-modified melamine resin, and with lead, cobalt and zinc naphthenate driers. The pigment dispersion, more methylcellulose an aqueous polyamide dispersion (Acravac C), more ammonium caseinate, and more sodium lauryl sulphate are then mixed in a high-speed turbine mixer with slow addition of the resin mixture to produce a colour concentrate containing 12.68 per cent pigment.  The product can, if desired, be emulsion polymerized by adjustment of the pH to 10-11 with ammonia and addition of a little hydrogenperoxide with agitation. Specifications 597,868, 642,652, 774,080, [Group IV (a)], also are referred to.  Reference has been directed by the Comptroller to Specifications 774,078, [Group IV (a)], and 774,079.ALSO:An oil-in-water emulsion colour concentrate is prepared by dispersing a pigment in water with the aid of a fatty alcohol sulphate, and emulsifying into the dispersion, while maintaining the pigment deflocculated, and in the presence of a protective colloid, a water-insoluble resinous polyester containing residues of a polyunsaturated monocarboxylic acid derived from a natural fat or oil.  Preferably the polyester is used as a solution.  The fatty alcohol sulphate, e.g. sodium lauryl sulphate, acts as emulsifying agent for the resin as well as dispersing agent for the pigment. Suitable resins referred to are condensation products of bisphenol and epichlorohydrin esterified with fatty acids as specified above; styrenated fatty acid-modified alkyds; styrenated oils; oil-modified alkyds; and pentaerythritol-glycerine mixed esters of maleic anhydride-modified fatty acids.  A number of commercially available resins are mentioned under their Trade names. Particularly suitable resins are those called E-polyesters in Specification 774,078. Organic solvent soluble urea- or melamine-formaldehyde resins may be included in the oil phase of the emulsions.  A number of emulsifying agents which may be used in addition to the fatty alcohol sulphates, and a number of protection colloids are specifically mentioned in the Specification.  Preferred kinds of pigments are phthalocyanine pigments, insoluble azo pigments, vat pigments and carbon blacks. Preferably the dispersing action of the fatty alcohol sulphate is aided by addition of a sodium alkyl naphthalene sulphonate. Protective colloids, e.g. casein or methylcellulose may also be added to the pigment dispersion.  The resin may be slowly added to the pigment dispersion, or the pigment dispersion may be slowly stirred into the resin.  In the second case a water-in-oil emulsion is first formed and inversion then takes place.  In either case the colour concentrates may be homogenized, e.g. by colloid milling.  It is also possible to feed the two phases simultaneously in the right proportions to the emulsifying equipment.  In a typical example (A) a phthalocyanine blue press cake is mixed with sodium lauryl sulphate and sodium alkyl naphthalene sulphonate in a high-speed turbine mixer, with addition of an aqueous mixture containing ammonium caseinate, further sodium lauryl sulphate, preservatives, an anti-foaming agent, methyl cellulose, ammonia and a sequesrtating agent.  The final dispersion contains 66.97 per cent water.  (B) A 50 per cent xylol solution of E-polyester B as described in Specification 774,078 is mixed with a 50 per cent solution in butyl alcohol-xylol of a butyl-modified melamine resin, and with lead, cobalt and zinc naphthenate driers.  The pigment dispersion, more methylcellulose, an aqueous polyamide dispersion (Acrawax C), more ammonium caseinate, and more sodium lauryl sulphate are then mixed in a high-speed turbine mixer with slow addition of the resin mixture to produce a colour concentrate containing 12.68 per cent pigment.  The product can, if desired, be emulsion polymerized by adjustment of the pH to 10-11 with ammonia and addition of a little hydrogen peroxide with agitation. Specifications 597,868, [Group IV], 642,652 and 774,080 also are referred to.  Reference has been directed by the Comptroller to Specifications 774,078 and 774,079, [Group IV (c)]