Claims
- 1. A method for the continuous preparation of liquid silicone rubber base comprising:continuously supplying solely to an upper mixing compartment of a continuous mixing apparatus (A) 100 weight parts polyorganosiloxane that has a viscosity at 25° C. of 100 to 500,000 mPa·s comprising at least 2 silicon-bonded alkenyl groups in each molecule, (B) 0 to 200 weight parts electrically nonconductive inorganic filler, and (C) 0.1 to 700 weight parts electrically conductive filler with a specific surface area of at least 0.5 m2/g, wherein the combined quantity of components (B) and (C) is from 5 to 700 weight parts thereby forming a mixture, where the continuous mixing apparatus comprises a cylindrical body casing having a starting material feed opening only at the top of the cylindrical body casing, a mixture discharge outlet at the bottom of the cylindrical body casing, a rotating disk positioned within the casing dividing the cylindrical body casing into the upper mixing compartment and a lower mixing compartment where the rotating disk has at least one scraper extending therefrom into the lower mixing compartment and adapted for scraping the interior wall of the cylindrical body casing forming the lower mixing compartment and the ratio of the diameter of the rotating disk to the inside diameter of the casing is 0.80 to 0.95 thereby creating a flow space between the circumference of the rotating disk and the interior wall of the cylindrical body casing for the mixture, where the internal wall of the cylindrical body casing forming the lower mixing compartment provides an unobstructed flow for the mixture from the upper mixing compartment and where rotation of the rotating disk provides mixing in the upper mixing compartment and further mixing of the mixture as it flows through the flow space formed between the circumference of the rotating disk and the interior wall of the cylindrical body casing and by action of the scraper extending therefrom into the lower mixing compartment; and discharging the mixture through the discharge outlet.
- 2. The method of claim 1 in which the polyorganosiloxane is polydiorganosiloxane, component (B) is reinforcing silica, and component (C) is carbon black.
- 3. The method of claim 1 where 1 to 150 weight parts component (B) to 100 parts component (A) are continuously supplied to the continuous mixing apparatus.
- 4. The method of claim 1 where 5 to 60 weight parts component (B) to 100 parts component (A) are continuously supplied to the continuous mixing apparatus.
- 5. The method of claim 1 where component (C) has a specific surface area of at least 10 m2/g and is continuously supplied at 0.1 to 50 weight parts per 100 weight parts component (A) to the continuous mixing apparatus.
- 6. The method of claim 1 where component (C) is a metal micropowder and is supplied at 100 to 700 weight parts per 100 weight parts component (A).
- 7. The method of claim 1 where components (A) through (C) are mixed at a temperature of 30° C. to 300° C.
- 8. The method of claim 1 where component (C) is a metal micropowder and components (A) through (C) are mixed below the melting point of the metal micropowder.
- 9. The method of claim 1 where the rotating disk rotates at a speed between 400 rpm and 3000 rpm.
- 10. The method of claim 1 where component (C) has a surface are of at least 10 m2/g and the rotating disk rotates at a speed of 400 rpm to 1500 rpm.
- 11. The method of claim 1 where the ratio of the diameter of the rotating disk to the inside diameter of the cylindrical body casing is 0.85 to 0.9.
Priority Claims (2)
Number |
Date |
Country |
Kind |
8-280362 |
Sep 1996 |
JP |
|
9-166610 |
Jun 1997 |
JP |
|
Parent Case Info
This application is a continuation of Ser. No. 08/941,429 filed Sep. 30, 1997, now abandoned.
US Referenced Citations (4)
Number |
Name |
Date |
Kind |
4946893 |
Saito et al. |
Aug 1990 |
|
5352724 |
Fujiki et al. |
Oct 1994 |
|
5599102 |
Hamada et al. |
Feb 1997 |
|
6019498 |
Hamada et al. |
Feb 2000 |
|
Continuations (1)
|
Number |
Date |
Country |
Parent |
08/941429 |
Sep 1997 |
US |
Child |
09/383433 |
|
US |