# US 2022/0033657 A1 · Aluminas and Methods for Producing Same

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- Number: US 2022/0033657 A1
- Document ID: US20220033657A1
- Status: Published application
- Kind: A1
- Application number: 17/276,524
- Filed: 2019-10-02
- Published: 2022-02-03
- Earliest claimed: 2018-10-03
- Applicants: Sasol (USA) Corporation
- Inventors: Brian Peoples; Allison Hann
- Web page: https://patentgrep.com/patent/US20220033657A1

## CPC

- C09C 1/40: Compounds of aluminium {(C09C1/0009, C09C1/0015, C09C1/0078, C09C1/32 take precedence)}
- C09C 1/407: {Aluminium oxides or hydroxides}
- C01P 2004/51: Particles with a specific particle size distribution
- C01P 2004/64: Nanometer sized, i.e. from 1-100 nanometer
- C01P 2006/22: Rheological behaviour as dispersion, e.g. viscosity, sedimentation stability
- 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}
- C01P: INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS

## Abstract

The present invention is directed to a method for producing a modified alumina by modifying a surface of an alumina with the addition of a phosphono group containing modifier. The invention is further directed to a modified alumina produced according to the method of the present invention and to a modified alumina having specific characteristics.

## Claims

### Claim 1

A method for producing a modified alumina including the steps of:
i) providing an alumina, wherein the alumina is an aluminium oxyhydroxide; and
ii) adding an phosphono group containing modifier to the alumina to produce a surface modified alumina.

### Claim 2 (depends on 1)

2) The method of claim 1 including a further step of aging the alumina before the addition of the phosphono group containing modifier to form an aged alumina having a crystallite size of 35 to 450 Å (as measured on the 120 plane).

### Claim 3 (depends on 1)

3) The method of claim 1 including a further step of aging the surface modified alumina to form an aged surface modified alumina.

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

4) The method of any one of claims 1 to 3 including the further steps of aging the alumina before the addition of the phosphono group containing modifier to form an aged alumina having a crystallite size of 35 to 450 Å (as measured on the 120 plane) and aging the surface modified alumina to form an aged surface modified alumina.

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

5) The method of any one of claims 1 to 4 including drying the surface modified alumina or the aged surface modified alumina.

### Claim 6 (depends on 1)

6) The method of claim 1 wherein the phosphono containing modifier includes an organic phosphorous compound and at least one carboxyl (COOH) group bearing at least one phospono moiety.

### Claim 7 (depends on 6)

7) The method of claim 6 wherein the phosphono moiety includes a primary phosphono-alkylcarboxylic acid, a secondary phosphono-alkylcarboxylic acids, a primary dicarboxylic acid, a secondary alkyl dicarboxylic acid, a primary phosphono-alkyl tricarboxylic acid, a phosphine alkane carboxylic acid or mixtures thereof.

### Claim 8 (depends on 1, 6, 7)

8) The method of any one of claim 1, 6 or 7 wherein the phosphono group containing modifier is added in amounts of from less than 10 wt. % based on the alumina, preferably in amounts between 3 wt. % and 10 wt. % based on the alumina, more preferably in amounts of from less than 8 wt. % based on the alumina, and most preferably in amounts between 3 wt. % and 8 wt. % based on the alumina.

### Claim 9 (depends on 1, 2, 4)

9) The method of any one of claim 1, 2 or 4 wherein the alumina is aged at a temperature of between 100° C. and 200° C. for a period of between 0.5 and 4 hours.

### Claim 10 (depends on 1, 3, 4)

10) The method of any one of claims 1, 3 and 4 wherein the surface modified alumina is aged at a temperature of between 95° C. and 125° C. for a period of between 0.5 and 2 hours.

### Claim 11 (depends on 1, 5)

11) The method of claim 1 or 5 wherein drying takes place at a temperature of between 85° C. and 250° C.

### Claim 12 (depends on 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11)

12) A modified alumina produced according to the method of any one of claims 1 to 11.

### Claim 13

13) A modified alumina including at least one of the following characteristics, preferably more than one of the following characteristics and most preferably all of the following characteristics after dispersion at a pH of 8 or above:
i) an isoelectric point of at a pH of less than 4;
ii) a dispersibility of greater than 90% when dispersed at a loading of 5, 10 or 20% into a basic solutions;
iii) a particle size distribution having a D50 below 250 nm when dispersed at a loading of 5, 10 or 20% into a basic solutions; and/or, preferably and
iv) a viscosity of less than 50 cP at 500 s−1.