# US 2013/0152827 A1 · Polysiloxane-Coated Iron Oxide Pigments

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- Number: US 2013/0152827 A1
- Document ID: US20130152827A1
- Status: Published application
- Kind: A1
- Application number: 13/643,014
- Filed: 2011-04-21
- Published: 2013-06-20
- Earliest claimed: 2010-04-23
- Assignees: Rockwood Italia S.p.A.
- Inventors: Gerardo Ripandelli; Daniela Fontana
- Web page: https://patentgrep.com/patent/US20130152827A1

## CPC

- C04B 14/308: {Iron oxide}
- C04B 20/1051: {Organo-metallic compounds; Organo-silicon compounds, e.g. bentone}
- C09C 1/24: Oxides of iron
- C04B 2103/54: Pigments; Dyes
- C04B 2111/21: Efflorescence resistance
- C04B: LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE {(roofing granules E04D7/005)}; CERAMICS (devitrified glass-ceramics C03C10/00); REFRACTORIES; TREATMENT OF NATURAL STONE
- 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}

## Abstract

The present invention relates to iron oxide particles, consisting of a core and a coating, wherein the core is essentially selected from FeO(OH), Fe2O3, or Fe3O4, and mixtures thereof, and the coating comprises a polysiloxane coating, wherein the polysiloxane coating is present in an amount of 0.1% to 10% by weight based on the weight of the core.

## Claims

### Claim 1

Iron oxide particles, consisting of a core and a coating,
wherein the core is essentially selected from FeO(OH), Fe2O3, or Fe3O4, and mixtures thereof, and the coating comprises a polysiloxane coating, wherein the polysiloxane coating is present in an amount of 0.1% to 10% by weight based on the weight of the core.

### Claim 2 (depends on 1)

Iron oxide particles according to claim 1,
wherein the polysiloxane coating is present in an amount of 0.3% to 5% by weight, preferably 0.5% to 3% by weight, more preferably 0.75% to 3% by weight, even more preferably 1% to 3% by weight, based on the weight of the core.

### Claim 3 (depends on 1, 2)

Iron oxide particles according to claim 1 or claim 2,
wherein the polysiloxane is selected from polyalkylsiloxane, polyalkoxysiloxane, and polyarylsiloxane.

### Claim 4 (depends on 1, 2, 3)

Iron oxide particles according to any one of claims 1-3,
wherein the polysiloxane is a polydimethylsiloxane, polydiethylsiloxane, polydipropylsiloxane or polydiphenylsiloxane, and preferably is polydimethylsiloxane.

### Claim 5 (depends on 1, 2, 3, 4)

Iron oxide particles according to any one of claims 1-4,
wherein the polysiloxane has a viscosity of 2 to 2000 cps, preferably has a viscosity of 10 to 1500 cps, and more preferably has a viscosity of 50 to 500 cps.

### Claim 6 (depends on 1, 2, 3, 4, 5)

Iron oxide particles according to any one of claims 1-5,
wherein the core is essentially spherical, cubical or acicular.

### Claim 7 (depends on 1, 2, 3, 4, 5, 6)

Iron oxide particles according to any one of claims 1-6,
wherein the particles have an average particle size of 0.01 to 2 μm, preferably 0.1 to 1 μm.

### Claim 8 (depends on 7)

Iron oxide particles according to claim 7,
wherein the iron oxide particles are present in powder form.

### Claim 9 (depends on 1, 2, 3, 4, 5, 6, 7, 8)

Iron oxide granulate obtainable from the iron oxide particles according to any one of claims 1 to 8,
wherein the iron oxide particles are present in granulated form having a particles size of 0.05 to 1 mm.

### Claim 10 (depends on 1, 2, 3, 4, 5, 6, 7, 8, 9)

Cementitious composition, comprising iron oxide particles or an iron oxide granulate according to any one of claims 1 to 9.

### Claim 11 (depends on 10)

Cementitious composition according to claim 10,
wherein the iron oxide particles are included in the composition in an amount of up to 8% by weight, preferably is included in an amount of 1% to 6% by weight based on the dry weight of the cement content of the cementitious composition.

### Claim 12 (depends on 1, 2, 3, 4, 5, 6, 7, 8, 9)

Use of iron oxide particles or iron oxide granulate according to any one of claims 1 to 9 for coloring a cementitious material.

### Claim 13 (depends on 12)

Use according to claim 12 for reducing porosity of the material produced from the cementitious material.

### Claim 14 (depends on 12, 13)

Use according to claim 12 or claim 13 for reducing efflorescence of the material produced from the cementitious material.

### Claim 15 (depends on 12, 13, 14)

Use according to any one of claims 12 to 14,
wherein the cementitious material is concrete.