Patent ID: 7199256

Claim:
A method for preparing an organosilicon compound of the average compositional formula (1): (R 1 O) (3-p) (R 2 ) p Si—R 3 —S m —R 4 —(S n —R 4 ) q —S m —R 3 —Si(R 2 ) p (OR 1 ) (3-p) (1) wherein R 1 and R 2 each are a monovalent hydrocarbon group having 1 to 4 carbon atoms, R 3 and R 4 each are a divalent hydrocarbon group having 1 to 15 carbon atoms, m is a positive number of 1 to 3 on average and n is a positive number of 2 to 4 on average and m is less than n, p is 0, 1, or 2, and q is 1, 2, or 3, the method comprising the step of: reacting a halogen-terminated organosilicon compound of the general formula (2): (R 1 O) (3-p) (R 2 ) p Si—R 3 —S m —R 4 —X (2) wherein R 1 , R 2 , R 3 , R 4 , m and p are as defined above, X is a halogen atom, with an anhydrous alkali metal sulfide or anhydrous alkali metal polysulfide of the general formula(3): M 2 S r (3) wherein M is an alkali metal and r is a positive number of 1 to 4 on average, and optionally a halogen-containing compound of the general formula (4): X—R 4 —X (4) wherein R 4 and X are as defined above and/or sulfur.