Dyed lustrous pigments

Claim 2

In a colored lustrous pigment composition comprising translucent micaceous flakes coated with a dyestuff, the improvement wherein said dyestuff is an aluminum lake fixed onto the surface of the micaceous pigment by a smooth and uniform intermediate coating of aluminum hydroxide, the aluminum of said aluminum hydroxide being a chemically bound portion of said aluminum lake, the pigment composition being substantially devoid of agglomerated flakes and being substantially color fast.

Claim 3

A colored pigment composition according to claim 1, wherein said aluminum lake is present in a concentration of 0.001 - 5% by weight of the total composition.

Claim 4

A pigment composition according to claim 1, wherein interposed between said coating of aluminum hydroxide and micaceous flakes is a coating of a metal oxide selected from the group consisting of titanium dioxide, zirconium oxide and mixtures thereof.

Claim 5

A pigment composition according to claim 1, wherein said aluminum lake is a madder dye.

Claim 6

A pigment composition according to claim 1, wherein said aluminum hydroxide coating has a thickness of 1 - 100 nm.

Claim 7

A pigment composition according to claim 1, wherein said aluminum lake is formed from an azo dye.

Claim 8

A pigment composition comprising a micaceous pigment coated with a chelation compound of aluminum, said chelation compound having a solubility at 22° C. of less than 1 g. per liter of water and being capable of being reacted with a diazotized amine to form an azo dyestuff, wherein interposed between said chelation compound and said micaceous pigment is a smooth and uniform coating of aluminum hydroxide, the aluminum of said hydroxide being a part of said chelation compound.

Claim 9

A pigment composition comprising a micaceous pigment coated with a chelation compound of aluminum, said chelation compound having a solubility at 22° C. of less than 1 g. per liter of water and being capable of being reacted with a diazotized amine to form an azo dyestuff, wherein interposed between said chelation compound and said micaceous pigment is a smooth and uniform coating of aluminum hydroxide, the aluminum of said hydroxide being a part of said chelation compound.

Claim 10

A process for the production of the pigment composition of claim 1, comprising reacting translucent micaceous flakes coated with aluminum hydroxide with an aqueous solution of an organic hydroxyl group-containing dyestuff capable of forming an aluminum lake with aluminum ions.

Claim 11

A process according to claim 8, wherein said dyestuff forms a salt with aluminum ions.

Claim 12

A process according to claim 8, wherein interposed between said coating of aluminum hydroxide and micaceous flakes is a coating of a metal oxide selected from the group consisting of titanium dioxide, zirconium oxide and mixtures thereof.

Claim 13

A process for the production of the pigment composition of claim 1, comprising reacting translucent micaceous flakes coated with aluminum hydroxide with a solution of a chelate former which forms a precipitate with aluminum ions said precipitate having a solubility at 22° C. of less than 1 g. per liter of water, thereby forming a bound chelate compound with aluminum ions on said micaceous flakes, and conducting a coupling reaction with diazotized amine and said chelation compound to form said aluminum lake.

Claim 14

A process according to claim 11, wherein interposed between said coating of aluminum hydroxide and micaceous flakes is a coating of a metal oxide selected from the group consisting of titanium dioxide, zirconium oxide and mixtures thereof.

Claim 15

A pigment composition according to claim 1 wherein said aluminum hydroxide coating is precipitated and deposited on said micaceous flakes while the latter are suspended in water.

Claim 16

A pigment composition according to claim 7 wherein said aluminum hydroxide coating is precipitated and deposited on said micaceous flakes while the latter are suspended in water.

Claim 17

A pigment composition according to claim 1 wherein said aluminum hydroxide coating has a thickness of 4-45 nm.

Claim 18

A pigment composition according to claim 3 wherein said coating of metal oxide is coating of titanium dioxide having sufficient thickness to yield a blue interference color and wherein said dyestuff is an aluminum lake of 2, 4, 5, 7-tetraiodofluorscein, the resulting pigment composition being strong violet pink.

Claim 19

A pigment composition according to claim 3 wherein said coating of metal oxide is a coating of titanium dioxide having sufficient thickness to yield a green interference color and wherein said dyestuff is an aluminum lake of chlorophyll, the resulting pigment composition being blue green.

Claim 20

A pigment composition according to claim 3 wherein said coating of metal oxide is a coating of titanium dioxide having sufficient thickness to yield a blue interference color and wherein said dyestuff is an aluminum lake of indigo-di-sulphonic acid, the resulting pigment composition being violet streaked light blue.

Claim 21

A pigment composition according to claim 3 wherein said coating of metal oxide is a coating of titanium dioxide having sufficient thickness to yield a red interference color and wherein said dyestuff is an aluminum lake of 4'-(4"-sulpho-1"-phenylazo)-7'-sulpho-1'-naphthylaza)-1-hydroxy-8-acetylaminonaphthalene-3,5-disulphonic acid, the resulting pigment composition being violet.

Claim 22

A pigment composisiont according to claim 1 wherein interposed between said coating of aluminum hyudroxide and micaceous falkes is coating of titanium dioxide on the micaceous flakes and a coating of ferric oxide on titanium dioxide, yielding a strong yellow interference color, and wherein the dyestuff is an aluminum lake of 2-(4-sulpho-1-naphthylazo)-1-naphthol-4-sulphonic acid, the resultant pigment composition being gold ochre.

Claim 23

A pigment composition according to claim 7 further comprising an azo dyestuff bonded to the chelation compound through the reaction of a diazotized amine therewith, the pigment composition being substantially color fast and substantially devoid of agglomerated flakes.