Particulate silica

• US 20090230351A1
• Filed: 05/19/2005
• Published: 09/17/2009
• Est. Priority Date: 05/19/2005
• Status: Active Grant

• Current Assignee: Tokuyama Corporation
• Original Assignee: Tokuyama Corporation
• Inventors: Ishimoto, Ryuji, Nagatani, Yasuhiro, Ariyuki, Masao
• Granted Patent: US 7,824,644 B2
• Time in Patent Office: Days
• US Class Current: 252/182.320
• CPC Class Codes: B41M 5/5218 characterised by inorganic additives, e.g. pigments, clays
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: C01B 33/12 Silica; Hydrates thereof, e.g. lepidoic silicic acid
• CPC Class Codes: C01B 33/183 by oxidation or hydrolysis in the vapour phase of silicon compounds such as halides, trichlorosilane, monosilane
• CPC Class Codes: C01P 2004/64 Nanometer sized, i.e. from 1-100 nanometer
• CPC Class Codes: C01P 2006/12 Surface area
• CPC Class Codes: C01P 2006/22 Rheological behaviour as dispersion, e.g. viscosity, sedimentation stability
• CPC Class Codes: C08K 3/36 Silica
• CPC Class Codes: C09C 1/30 Silicic acid
• CPC Class Codes: C09C 1/3081 Treatment with organo-silicon compounds
• CPC Class Codes: C09D 7/43 Thickening agents
• CPC Class Codes: C09G 1/02 containing abrasives or grinding agents abrasives as such C09K3/14; polishing of semi-conductors H01L
• CPC Class Codes: C09K 3/1436 Composite particles, e.g. coated particles
• CPC Class Codes: C09K 3/1463 Aqueous liquid suspensions
• CPC Class Codes: C09K 3/32 for absorbing liquids to remove pollution, e.g. oil, gasoline, fat
• CPC Class Codes: D21H 17/68 siliceous, e.g. clays
• CPC Class Codes: D21H 19/40 siliceous, e.g. clays
• CPC Class Codes: D21H 21/52 Additives of definite length or shape
• CPC Class Codes: Y10T 428/2993 Silicic or refractory material containing [e.g., tungsten oxide, glass, cement, etc.]

Abstract

There is provided particulate silica which can be suitably used as a viscoelasticity modifier such as a thickener which is added to liquid such as water, a liquid resin or paint to adjust its viscoelastic properties such as viscosity and thixotropic nature, a reinforcer or filler for silicone rubber or sealants, a polishing agent for CMP (Chemical Mechanical Polishing) or a surface coating agent for ink-jet printing paper.

The particulate silica has a BET specific surface area S of 130 to 380 m²/g, and its fractal shape parameter α1 in an α-value analysis target range of 20 to 30 nm satisfies the following equation (1) and its fractal shape parameter α2 in an α-value analysis target range of 30 to 50 nm satisfies the following equation (2).

α1+0.00175S<2.518  (1)

α2+0.00174S<2.105  (2)

Claims

1. Particulate silica having a BET specific surface area (S) of 130 to 380 m²/g, wherein in small-angle X-ray scattering analysis, a fractal shape parameter (α

1) in an α

-value analysis target range of 20 to 30 nm satisfies the following equation (1) and a fractal shape parameter (α

2) in an α

-value analysis target range of 30 to 50 nm satisfies the following equation (2).

α

1+0.00175S<

2.518 

 

(1)

α

2+0.00174S<

2.105 

 

(2)

2. Hydrophobized particulate silica comprising the particulate silica of claim 1 and a hydrophobizing agent on the surface of said particulate silica.

3. An aqueous dispersion comprising the particulate silica of claim 1 dispersed in an aqueous solvent.

4. A thickener for liquid resins which comprises the particulate silica of claim 1.

5. A filler for resins which comprises the particulate silica of claim 1.

6. A filler for ink-jet printing paper which comprises the particulate silica of claim 1.

7. A method for producing particulate silica by flame-hydrolyzing a volatile silicon compound in the presence of hydrogen, wherein mixed gas comprising 20 to 90 vol % of trichlorosilane and 10 to 80 vol % of tetrachlorosilane is used as the volatile silicon compound, and the amount of hydrogen used in flame hydrolysis is 1.20 to 2.20 times the theoretical amount.