The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 28, 1986
Filed:
Jun. 25, 1984
David J Huebner, Midland, MI (US);
John C Saam, Midland, MI (US);
Dow Corning Corporation, Midland, MI (US);
Abstract
This invention is a method of producing a latex of crosslinked polydiorganosiloxane reinforced with colloidal silica. The method allows the production of a latex having a relatively high amount of silica present in relation to the polymer because the water used to form the emulsion can be that present in the acidic colloidal silica sol used in the method. The high solids latex can be useful as a caulking material. The method homogenizes a hydroxyl endblocked polydiorganosiloxane, a silane of the formula R'.sub.a Si(OR.sup.3).sub.4-a where R' is a monovalent hydrocarbon radical of up to 12 carbon atoms, R.sup.3 is an alkyl radical of 1 to 6 carbon atoms, a partial hydrolyzate, or mixture of silane and hydrolyzate, and a is 0 or 1; a surface active anionic catalyst of the formulae R.sup.2 C.sub.6 H.sub.4 SO.sub.3 H wherein R.sup.2 is a monovalent hydrocarbon radical of at least 6 carbon atoms, R.sup.2 OSO.sub.2 OH, or ##STR1## wherein R.sup.4 is H or R.sup.2 ; and greater than 1 part by weight of colloidal silica present as an acidic sol in water. This homogenized mixture is an oil-in-water emulsion. This emulsion is maintained at a temperature of 15.degree. to 30.degree. C. for at least 5 hours at a pH of less than 5 until a crosslinked polymer is formed. The product is a latex which produces an elastomer upon removal of the water at room temperature. Shelf stable products are produced by adjusting the pH to from 7 to 12.5.