Reinforced precipitated silica

• US 5,094,829 A
• Filed: 06/21/1990
• Issued: 03/10/1992
• Est. Priority Date: 06/21/1990
• Status: Expired due to Term

• Current Assignee: PPG Industries Incorporated (Nouryon BV)
• Original Assignee: PPG Industries Incorporated (Nouryon BV)
• Inventors: Okel, Timothy A., Krivak, Thomas G., Wagner, Melvin P.
• Primary Examiner(s): Chaudhuri, Olik
• Assistant Examiner(s): HORTON, KENNETH
• Application Number:
  US07/541,679
• Time in Patent Office: 628 Days
• Field of Search: 423/335, 423/339, 424/49, 502/8
• US Class Current: 423/339
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: C01B 33/193 of aqueous solutions of silicates
• CPC Class Codes: C01P 2002/02 Amorphous compounds
• CPC Class Codes: C01P 2004/04 obtained by TEM, STEM, STM or AFM
• CPC Class Codes: C01P 2004/50 Agglomerated particles
• CPC Class Codes: C01P 2004/61 Micrometer sized, i.e. from 1-100 micrometer
• CPC Class Codes: C01P 2004/64 Nanometer sized, i.e. from 1-100 nanometer
• CPC Class Codes: C01P 2006/10 Solid density
• CPC Class Codes: C01P 2006/12 Surface area
• CPC Class Codes: C01P 2006/14 Pore volume
• CPC Class Codes: C01P 2006/16 Pore diameter
• CPC Class Codes: C01P 2006/17 Pore diameter distribution
• CPC Class Codes: C01P 2006/80 Compositional purity
• CPC Class Codes: C01P 2006/82 water content
• CPC Class Codes: C01P 2006/90 Other properties not specified above
• CPC Class Codes: C08K 3/36 Silica
• CPC Class Codes: C08L 83/04 Polysiloxanes
• CPC Class Codes: C09C 1/30 Silicic acid
• CPC Class Codes: C09C 1/3081 Treatment with organo-silicon compounds

Abstract

Reinforced precipitated silica having, on a coating-free and impregnant-free basis, a surface area of from about 220 to about 340 square meters per gram, a pore diameter at the maximum of the volume pore size distribution function of from about 9 to about 20 nanometers, and a total intruded volume of from about 2.6 to about 4.4 cubic centimeters per gram, is produced by a process wherein precipitated silica is heavily reinforced using a multiplicity of precipitation and aging steps.

Claims

1. Reinforced amorphous precipitated silica having, on a coating-free and impregnant-free basis, a surface area of from about 220 to about 340 square meters per gram, a pore diameter at the maximum of the volume pore size distribution function of from about 9 to about 20 nanometers, and a total intruded volume of from about 2.6 to about 4.4 cubic centimeters per gram.

2. The reinforced amorphous precipitated silica of claim 1 wherein said surface area is from about 220 to about 300 square meters per gram.

3. The reinforced amorphous precipitated silica of claim 1 wherein said surface area is from about 220 to about 270 square meters per gram.

4. The reinforced amorphous precipitated silica of claim 1 wherein said pore diameter at the maximum of the volume pore size distribution function is from about 13 to about 18 nanometers.

5. The reinforced amorphous precipitated silica of claim 1 wherein said total intruded volume is from about 3 to about 4.4 cubic centimeters per gram.

6. The reinforced amorphous precipitated silica of claim 1 which contains less than about 0.5 percent by weight alkali metal salt.

7. The reinforced amorphous precipitated silica of claim 1 which contains less than about 0.2 percent by weight alkali metal salt.

8. The reinforced amorphous precipitated silica of claim 1 which is hydrophobic.

9. The reinforced amorphous precipitated silica of claim 8 which comprises silicone oil or condensation residue thereof.

10. The reinforced amorphous precipitated silica of claim 1 wherein:

(a) said pore diameter at the maximum of the volume pore size distribution function is from about 13 to about 18 nanometers; and

(b) said total intruded volume is from about 3 to about 4.4 cubic centimeters per gram.

11. The reinforced amorphous precipitated silica of claim 10 wherein said surface area is from about 220 to about 300 square meters per gram.

12. The reinforced amorphous precipitated silica of claim 10 wherein said surface area is from about 220 to about 270 square meters per gram.