Claims
- 1. A method for increasing the bulk density of fumed silica comprising:
- (A) adding to a suitable mixing vessel:
- (1) a low bulk density fumed silica, and
- (2) at least 60% by weight based on the weight of (1) of organopolysiloxane liquid effective for densifying said low bulk density material;
- (B) mixing said low bulk density material and said organopolysiloxane liquid for an amount of time effective to decrease the volume of said low bulk density material; and
- (C) removing substantially all of said organopolysiloxane liquid from said low bulk density material so as to provide a material substantially free of agglomerates and grit and having an increased bulk density.
- 2. The method of claim 1 wherein the organopolysiloxane liquid is a non-polar liquid.
- 3. The method of claim 1 wherein the organopolysiloxane liquid is selected from the group consisting of octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, octamethyltrisiloxane and decamethyltetrasiloxane.
- 4. The method of claim 1 wherein organopolysiloxane liquid is octamethylcyclotetrasiloxane.
- 5. The method of claim 1 wherein in step (A) the organopolysiloxane liquid is added to the mixing vessel by spraying while the low bulk density material is turbulently mixed.
- 6. The method of claim 1 wherein the low bulk density fumed silica was previously partially densified.
- 7. The method of claim 6 wherein partial densification was effected by mechanical means.
- 8. The method of claim 1 wherein removal of substantially all of the organopolysiloxane liquid is effected by evaporation.
- 9. A method for increasing the bulk density of fumed silica, comprising:
- (A) adding to a suitable mixing vessel:
- (1) 100 parts by weight fumed silica and
- (2) at least 60 parts by weight octamethylcyclotetrasiloxane;
- (B) mixing said fumed silica and said octamethylcyclotetrasiloxane for about one minute; and
- (C) evaporating substantially all of said octamethylcyclotetrasiloxane so as to provide fumed silica having an increased bulk density.
- 10. The method of claim 9, further comprising after step (C), treating said fumed silica with octamethylcyclotetrasiloxane by heating at a temperature of at least 250.degree. C.
Parent Case Info
This application is a continuation of application Ser. No. 641,083, filed 08/15/84, now abandoned.
US Referenced Citations (13)
Non-Patent Literature Citations (3)
Entry |
Hawley, Condensed Chemical Dictionary 8th Ed. Van Nostrand 1971, p. 784. |
McGraw-Hill Encyclopedia of Chemistry N.Y. 1982, p. 941. |
Van Nostrand Scientific Encyclopedia 6th Ed. N.Y. 1983. |
Continuations (1)
|
Number |
Date |
Country |
Parent |
641083 |
Aug 1984 |
|