Preparation and use of improved pearlescent pigments of high light fastness

• US 4,323,554 A
• Filed: 07/11/1980
• Issued: 04/06/1982
• Est. Priority Date: 07/13/1979
• Status: Expired due to Term

• Current Assignee: Merck Patent GmbH (Merck & Co., Inc.)
• Original Assignee: Merck Patent GmbH (Merck & Co., Inc.)
• Inventors: Bernhard, Horst
• Primary Examiner(s): Albrecht, Dennis L.
• Application Number:
  US06/167,598
• Time in Patent Office: 634 Days
• Field of Search: 106/291, 106/308 B, 427/118, 427/220, 428/324, 428/363, 428/403, 424/63, 424/64, 424/69
• US Class Current: 424/63
• CPC Class Codes: C01P 2004/20 extending in two dimensions, e.g. plate-like
• CPC Class Codes: C01P 2004/84 one phase coated with the other
• CPC Class Codes: C09C 1/0015 Pigments exhibiting interference colours, e.g. transparent platelets of appropriate thinness or flaky substrates, e.g. mica, bearing appropriate thin transparent coatings
• CPC Class Codes: C09C 2200/102 the core consisting of glass or silicate material like mica or clays, e.g. kaolin
• CPC Class Codes: C09C 2200/401 Inorganic protective coating
• CPC Class Codes: C09C 2200/403 Low molecular weight materials, e.g. fatty acids
• CPC Class Codes: C09C 2200/404 comprising additional functional groups, e.g. -NH2, -C=C- or -SO3
• CPC Class Codes: C09C 2220/10 Wet methods, e.g. co-precipitation
• CPC Class Codes: Y10T 428/2911 Mica flake
• CPC Class Codes: Y10T 428/2991 Coated

Abstract

Colored material-containing pearlescent pigments based on mica flakes coated with metal oxide contain as colored material, a colored aluminum lake which is fixed as a water-insoluble compound on the surface of the pigment particles, the lake being formed from a precipitated aluminum hydroxide layer, wherein the aluminum hydroxide layer forming the colored lake contains 1 to 50% by weight of a compound of the formula ##STR1## wherein X is hydroxy or carboxy, Y is hydrogen or alkyl or alkenyl of 10 to 20 carbon atoms and Z is hydrogen, or alkyl or alkenyl of 10 to 20 carbon atoms, or the grouping ##STR2## said compound having a molecular weight of at least 150 and a solubility in water at a pH of 5-9 of at least 0.05 g/l, and said compound being precipitated onto the flakes together with the aluminum hydroxide layer. A process for the production of these pigments is also provided, as are cosmetics containing them.

Claims

1. A colored material-containing pearlescent pigment comprising mica flakes coated with a metal oxide, the colored material being a colored aluminum lake which is fixed as a water-insoluble compound on the surface of the pigment particles, the lake being formed by a precipitated aluminum hydroxide layer, wherein the aluminum hydroxide layer forming the colored lake contains an amount in the range of 1 to 50% by weight, sufficient to increase the light fastness of said pigment, of a compound of the formula ##STR5## wherein X is hydroxy or carboxy;

Y is hyrdrogen, or alkyl or alkenyl of 10 to 20 carbon atoms; and

Z is hydrogen, alkyl or alkenyl of 10 to 20 carbon atoms, or the grouping ##STR6## the compound having a molecular weight of at least 150 and a solubility in water at a pH of 5-9 of at least 0.05 g/l, and the compound being precipitated onto the metal oxide coated mica flakes together with the aluminum hydroxide layer.

2. A pigment of claim 1 wherein the light fastness increasing compound is sorbitol, oleic acid, stearic acid, palmitic acid, linolic acid, polyvinyl alcohol or polyacrylic acid.

3. A pigment of claim 1 containing 5-30% by weight of the light fastness increasing compound.

4. A pigment of claim 1 wherein the aluminum hydroxide layer contains 3 to 20% by weight of polyvinyl alcohol.

5. A pigment of claim 1 or 4, wherein the ratio of the number of groups X originating from the compound of said formula, to the number of molecules of Al(OH)₃ in the aluminum hydroxide layer is 1:

2 to 1;

10.

6. A process for producing the colored material-containing pearlescent pigment of claim 1 comprising precipitating an aluminum hydroxide layer onto mica flakes coated with metal oxide, and subsequently or simultaneously reacting the flakes with a solution of an hydroxy group-containing compound which, directly or with the intermediate formation of a sparingly soluble aluminum chelate followed by subsequent reaction thereof with a diazotized amine, is able to form a water-insoluble colored aluminum lake, wherein the precipitation of the aluminum hydroxide layer forming the colored lake takes place in the presence of such an amount of a compound of the formula recited in claim 1 that this compound is incorporated into the aluminum hydroxide layer in an amount of from 1 to 50% by weight, referred to Al(OH)₃.

7. A colored material-containing pearlescent pigment, produced by the process of claim 6.

8. A colored composition containing an amount of the pigment of claim 1 sufficient to alter the appearance of the composition, and a base ingredient which is different from said pigment.

9. A cosmetic composition containing an amount of the pigment of claim 1 sufficient to alter the appearance of the composition and a cosmetically acceptable carrier.