United States Patent [19]
Chevallier
[li] Patent Number: 4,708,859 [45] Date of Patent: Nov. 24, 1987
[54] SILICA WITH A HIGH OIL ABSORPTION CAPABILITY AND A CONTROLLED PRIMARY STRUCTURE AND PROCESS FOR THE PRODUCTION THEREOF
[75] Inventor: Yvonick Chevallier, Decines, France
[73] Assignee: Rhone-Poulenc Chimie, France
[21] Appl. No.: 879,492
[22] Filed: Jun. 24, 1986
Related U.S. Application Data
[63] Continuation of Ser. No. 753,874, Jul. 1 1, 1985, abandoned.
[30] Foreign Application Priority Data
Jul. 11, 1984 [FR] France 84 11004
[51] Int. CI.4 C01B 33/18; C01B 33/12
[52] U.S. CI 423/339; 423/335
[58] Field of Search 423/335, 339
[56] References Cited
U.S. PATENT DOCUMENTS
2,466,842 4/1949 Elston 252/313
2,577,485 12/1951 Rule 252/313
2,871,099 1/1959 Ziese 23/182
2,956,957 10/1960 Armstrong et al 252/313
3,337,299 8/1967 Burke, Jr 23/182
3,480,390 11/1969 Reinhardt et al 23/182
3,954,944 10/1976 Aldcroft et al 423/339
4,127,641 11/1978 Aldcroft et al 423/339
4,144,321 3/1979 Wason 423/339
4,191,742 3/1980 Wason et al 423/339
4,356,107 10/1982 Payne 252/313 S
4,590,052 5/1986 Chevallier et al 423/339
Primary Examiner—John Doll
Assistant Examiner—Lori S. Freeman
Attorney, Agent, or Firm—Finnegan, Henderson,
Farabow Garrett & Dunner
[57] ABSTRACT
Precipitation silicas, in the form of aggregates as shown in FIG. 1, having a mean projected area of the aggregates which is higher than about 8,000 nm2 and preferably is higher than about 15,000 nm2. The present invention also concerns a process for the production of precipitation silica by maintaining a constant-volume reaction medium to provide a suitable colloids of silica, reacting the colloids with an electrolyte and consolidating the resulting product by the addition of a solution of silicate and an acidifying agent to obtain a precipitation silica.
15 Claims, 6 Drawing Figures
