# US 5,707,440 A · Inorganic filler material with retention properties, and method and use of such material

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 5,707,440 A
- Document ID: US5707440A
- Status: Granted
- Kind: A
- Application number: 08/319,822
- Filed: 1994-10-07
- Granted: 1998-01-13
- Earliest claimed: 1993-10-07
- Assignees: Heraeus Kulzer GmbH
- Inventors: Xu Hengchang; Joachim Nagel
- Web page: https://patentgrep.com/patent/US5707440A

## CPC

- A61K 6/887: Compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds
- C03C 17/007: {containing a dispersed phase, e.g. particles, fibres or flakes, in a continuous phase}
- C08K 9/02: Ingredients treated with inorganic substances
- C09C 1/28: Compounds of silicon {(C09C1/0009, C09C1/0015, C09C1/0078 take precedence)}
- C09C 3/06: Treatment with inorganic compounds {(C09C3/006, C09C3/048 take precedence)}
- C01P 2002/02: Amorphous compounds
- C01P 2004/61: Micrometer sized, i.e. from 1-100 micrometer
- C01P 2004/62: Submicrometer sized, i.e. from 0.1-1 micrometer
- C03C 2217/42: consisting of particles only
- Y10T 428/2991: Coated
- Y10T 428/2993: Silicic or refractory material containing [e.g., tungsten oxide, glass, cement, etc.]
- Y10T 428/2996: Glass particles or spheres
- A61K: PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES (devices or methods specially adapted for bringing pharmaceutical products into particular physical or administering forms A61J3/00; chemical aspects of, or use of materials for deodorisation of air, for disinfection or sterilisation, or for bandages, dressings, absorbent pads or surgical articles A61L; soap compositions C11D)
- C03C: CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
- C08K: Use of inorganic or non-macromolecular organic substances as compounding ingredients (paints, inks, varnishes, dyes, polishes, adhesives C09)
- 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
- Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION

## Abstract

A finely divided inorganic filler material is a sintered composite which consists of larger macro-filler particles of glass and of smaller micro-filler particles of glass or ceramics partially covering the macro-filler particle and firmly connected to it by sintering. Plastic materials reinforced with the filler are distinguished by improved abrasion resistance.

## Claims

### Claim 1

A method for producing a finely divided inorganic filler comprising composite filler particles made of macro-filler particles and micro-filler particles; and wherein the composite filler particle has a mean particle size between 0.3 and 12 micrometers; comprising the steps of
providing macro-filler particles and micro-filler particles wherein the macro-filler particles are larger than the micro-filler particles and have a lower melting point, the macro-filler particles consist of glass and have a mean particle size between 0.2 and 10 micrometers, and the micro-filler particles consist of a nitride, carbide or oxide of one of the elements silicon, zirconium or aluminum and have a mean particle size between 0.01 and 1.5 micrometers;
mixing the macro-filler particles and the micro-filler particles to produce an intimate mixture thereof;
sintering the mixture to secure the micro-filler particles to the surface of the macro-filler particles to form a sintered product;
dispersing the sintered product in a liquid using ultrasonic waves;
allowing coarser sintered product particles to settle from the dispersion; and
centrifuging the dispersion to recover the finely divided inorganic filler.

### Claim 2 (depends on 1)

The method in accordance with claim 1, wherein the macro-filler particles have a melting point at least 40.degree. C. lower than the micro-filler particles and the sintering step comprises heating the mixture to melt the surface of the macro-filler particles.

### Claim 3 (depends on 1)

The method in accordance with claim 1, wherein the mixture of macro-filler particles and micro-filler particles is sintered in the range of 650.degree. to 1200.degree. C.

### Claim 4 (depends on 1)

The method in accordance with claim 1, wherein the macro-filler particles are made of borosilicate glass or aluminosilicate glass.

### Claim 5 (depends on 1)

The method in accordance with claim 1, wherein the micro-filler particles consist of SiO.sub.2, ZrO.sub.2 or Al.sub.2 O.sub.3.

### Claim 6 (depends on 1)

The method in accordance with claim 1, further comprising treating the composite filler with a silane.

### Claim 7 (depends on 6)

The method in accordance with claim 6, wherein the silane is 3-methacryloyl oxypropyl trimethoxy silane.

### Claim 8 (depends on 1)

The method in accordance with claim 1, wherein the macro-filler particles and the micro-filler particles are present in a weight ratio of 1:1-12.

### Claim 9 (depends on 8)

The method in accordance with claim 8, wherein
the macro-filler particles have a mean particle size between 0.2 and 2 micrometers and a melting point at least 40.degree. C. lower than the micro-filler particles; and the sintering step comprises heating the mixture to soften or melt the surface of the macro-filler particles.

### Claim 10 (depends on 9)

The method in accordance with claim 9, wherein
the mixture of macro-filler particles and micro-filler particles is sintered in the range of 650.degree. to 1200.degree. C.;
the macro-filler particles are made of borosilicate glass or aluminosilicate glass; and
the micro-filler particles are made of SiO.sub.2, ZrO.sub.2 or Al.sub.2 O.sub.3.

### Claim 11 (depends on 10)

The method in accordance with claim 10, further comprising treating the composite filler with a silane, and
wherein the silane is 3-methacryloyl oxypropyl trimethoxy silane.

### Claim 12 (depends on 1)

The method in accordance with claim 1, wherein
the macro-filler particles and the micro-filler particles are present in a weight ratio of 1:1-12;
the macro-filler particles have a melting point at least 40.degree. C. lower than the micro-filler particles and the sintering step comprises heating the mixture to soften or melt the surface of the macro-filler particles;
the macro-filler particles are made of borosilicate glass or aluminosilicate glass; and
the micro-filler particles are made of SiO.sub.2, ZrO.sub.2 or Al.sub.2 O.sub.3.

### Claim 13 (depends on 1)

The method in accordance with claim 1 further comprising that the sintered product is ground prior to ultrasonic treatment.

### Claim 14 (depends on 1)

The method of claim 1 wherein the macro-filler particles have a mean particle size between 0.2 and 2 micrometers and the micro-filler particles have a mean particle size between 0.01 and 0.3 micrometers.