# US 10,479,901 B2 · Magnetic multilayer pigment flake and coating composition

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- Number: US 10,479,901 B2
- Document ID: US10479901B2
- Status: Granted
- Kind: B2
- Application number: 15/812,824
- Filed: 2017-11-14
- Published: 2018-03-08
- Granted: 2019-11-19
- Earliest claimed: 2010-06-30
- Assignees: Viavi Solutions Inc.
- Applicants: Viavi Solutions Inc.
- Inventors: Vladimir P. Raksha; Paul T. Kohlmann; Cornelis Jan Delst; Paul G. Coombs
- Web page: https://patentgrep.com/patent/US10479901B2

## CPC

- C09D 7/62: modified by treatment with other compounds
- 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}
- C09D 5/32: Radiation-absorbing paints {(protection against X-, gamma- or corpuscular radiation G21F)}
- C09D 7/70: {characterised by shape, e.g. fibres, flakes or microspheres}
- C09D 11/037: characterised by the pigment
- C09D 17/004: {containing an inorganic pigment}
- H01F 1/01: of inorganic materials (H01F1/44 takes precedence)
- H01F 1/0306: {Metals or alloys, e.g. LAVES phase alloys of the MgCu2-type (H01F1/0304 takes precedence)}
- H01F 1/28: dispersed or suspended in a bonding agent
- C01P 2004/54: Particles characterised by their aspect ratio, i.e. the ratio of sizes in the longest to the shortest dimension
- C01P 2004/61: Micrometer sized, i.e. from 1-100 micrometer
- C01P 2006/42: Magnetic properties
- C01P 2006/60: Optical properties, e.g. expressed in CIELAB-values
- C09C 2200/1054: the core consisting of a metal
- C09C 2210/00: Special effects or uses of interference pigments
- H01F 1/26: by macromolecular organic substances
- C09D: COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR (cosmetics A61K; processes for applying liquids or other fluent materials to surfaces, in general, B05D; staining wood B27K5/02; glazes or vitreous enamels C03C; natural resins, French polish, drying-oils, driers, turpentine, per se, C09F; polishing compositions other than French polish, ski waxes C09G; adhesives or use of materials as adhesives C09J; materials for sealing or packing joints or covers C09K3/10; materials for stopping leaks C09K3/12; processes for the electrolytic or electrophoretic production of coatings C25D)
- C09C: TREATMENT OF INORGANIC MATERIALS, OTHER THAN FIBROUS FILLERS, TO ENHANCE THEIR PIGMENTING OR FILLING PROPERTIES (treatment of materials specially adapted to enhance their filling properties in mortars, concrete or artificial stone C04B14/00, C04B18/00, C04B20/00); PREPARATION OF CARBON BLACK {; PREPARATION OF INORGANIC MATERIALS WHICH ARE NO SINGLE CHEMICAL COMPOUNDS AND WHICH ARE MAINLY USED AS PIGMENTS OR FILLERS}
- H01F: MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- C01P: INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS

## Abstract

The present invention provides a magnetic multilayer pigment flake and a magnetic coating composition that are relatively safe for human health and the environment. The pigment flake includes one or more magnetic layers of a magnetic alloy and one or more dielectric layers of a dielectric material. The magnetic alloy is an iron-chromium alloy or an iron-chromium-aluminum alloy, having a substantially nickel-free composition. The coating composition includes a plurality of the pigment flakes disposed in a binder medium.

## Claims

### Claim 1

A symmetric pigment flake, comprising:
a plurality of semi-transparent absorbing magnetic layers;
a plurality of dielectric layers; and
a plurality of opaque reflecting magnetic layers; and
wherein two opaque reflecting magnetic layers of the plurality of opaque reflecting magnetic layers have a larger physical thickness than that of two other opaque reflecting magnetic layers.

### Claim 2 (depends on 1)

The symmetric pigment flake of claim 1, wherein each opaque reflecting magnetic layer has a physical thickness that is larger than that of each of the plurality of semi-transparent absorbing magnetic layers.

### Claim 3 (depends on 1)

The symmetric pigment flake of claim 1, wherein three dielectric layers of the plurality of dielectric layers have a same physical thickness.

### Claim 4 (depends on 3)

The symmetric pigment flake of claim 3, wherein the three dielectric layers each have a smaller physical thickness than that of two other dielectric layers of the plurality of dielectric layers.

### Claim 5 (depends on 1)

The symmetric pigment flake of claim 1, wherein the two opaque reflecting magnetic layers each have a physical thickness that is larger than that of each of the plurality of semi-transparent absorbing magnetic layers.

### Claim 6 (depends on 1)

The symmetric pigment flake of claim 1, wherein a physical thickness of one of the plurality of dielectric layers is smaller than that of two other of the plurality of dielectric layers.

### Claim 7 (depends on 6)

The symmetric pigment flake of claim 6, wherein the plurality of dielectric layers includes three sets of dielectric layers each with a different physical thickness.

### Claim 8 (depends on 1)

The symmetric pigment flake of claim 1, wherein the plurality of semi-transparent absorbing magnetic layers includes a first semi-transparent absorbing magnetic layer and a second semi-transparent absorbing magnetic layer.

### Claim 9 (depends on 1)

The symmetric pigment flake of claim 1, wherein the plurality of dielectric layers includes a first dielectric layer, a second dielectric layer, a third dielectric layer, a fourth dielectric layer, and fifth dielectric layer.

### Claim 10 (depends on 1)

The symmetric pigment flake of claim 1, wherein the plurality of opaque reflecting magnetic layers includes a first opaque reflecting magnetic layer, a second opaque reflecting magnetic layer, a third opaque reflecting magnetic layer, and a fourth opaque reflecting magnetic layer.

### Claim 11 (depends on 1)

The symmetric pigment flake of claim 1, wherein the flake has an aspect ratio of at least 2:1.

### Claim 12 (depends on 1)

The symmetric pigment flake of claim 1, wherein the plurality of semi-transparent absorbing magnetic layers and the plurality of opaque reflecting magnetic layers include a same magnetic alloy.

### Claim 13 (depends on 1)

The symmetric pigment flake of claim 1, wherein the plurality of semi-transparent absorbing magnetic layers and the plurality of opaque reflecting magnetic layers include a different magnetic alloy.

### Claim 14 (depends on 1)

The symmetric pigment flake of claim 1, wherein the plurality of semi-transparent absorbing magnetic layers each have a physical thickness of about 3 nm to about 50 nm.

### Claim 15 (depends on 1)

The symmetric pigment flake of claim 1, wherein the plurality of opaque reflecting magnetic layers each have a physical thickness of about 20 nm to about 1000 nm.

### Claim 16 (depends on 1)

The symmetric pigment flake of claim 1, wherein the plurality of dielectric layers each have a physical thickness of about 100 nm to about 5000 nm.

### Claim 17 (depends on 1)

The symmetric pigment flake of claim 1, wherein the pigment flake has an interference layer structure that provides a color-shifting effect.

### Claim 18 (depends on 1)

The symmetric pigment flake of claim 1, wherein the two opaque reflecting magnetic layers having a larger physical thickness of the plurality of opaque reflecting magnetic layers are between the two other opaque reflecting magnetic layers.

### Claim 19 (depends on 6)

The symmetric pigment flake of claim 6, wherein a smaller transparent dielectric layer is between the two opaque reflecting magnetic layers having a larger physical thickness.

### Claim 20 (depends on 6)

The symmetric pigment flake of claim 6, wherein a smaller transparent dielectric layer is between the two other of the plurality of dielectric layers.