Hydrolysable silanes
View Patent ↗This invention relates to hydrolysable silanes useful in the modification of elastomers, and as coupling agents for diene elastomer compositions containing a filler. In particular the invention relates to novel hydrolysable silanes containing an aziridine ring herein named (Az).
1. A hydrolysable silane of the formula R a R′ 3-a Si-A-OC(O)-(Az)-Z wherein Z represents a hydrocarbyl or substituted hydrocarbyl group having 1 to 40 carbon atoms; R represents a hydrolysable group; R′ represents a hydrocarbyl group having 1 to 8 carbon atoms; a has a value in the range 1 to 3 inclusive; and A represents a divalent organic spacer linkage having at least one carbon atom, Az represents an aziridine ring wherein Z is bonded to Az through its nitrogen atom.
2. A hydrolysable silane according to claim 1 , characterised in that each group R is an alkoxy group having 1 to 4 carbon atoms.
3. A hydrolysable silane according to claim 2 , characterised in that each group R is an ethoxy group.
4. A hydrolysable silane according to claim 1 , characterised in that a=3.
5. A hydrolysable silane according to claim 1 , characterised in that A represents an alkylene group having 2 to 6 carbon atoms.
6. A hydrolysable silane according to claim 1 , characterised in that Z represents an alkyl group having 1 to 6 carbon atoms.
7. A hydrolysable silane according to claim 1 , characterised in that Z represents an aryl group having 6 to 10 carbon atoms.
8. A hydrolysable silane according to claim 1 , characterised in that Z represents a substituted alkyl group of the formula -A′-SiR a R′ 3-a in which R, R′ and a are defined as in claim 1 and A′ represents a divalent organic spacer linkage having at least one carbon atom separating the silicon atom from the aziridine ring.
9. A hydrolysable silane according to claim 1 of the formula (C 2 H 5 O) 3 Si—(CH 2 ) 3 —OC(O)-Az-(CH 2 ) 3 —Si(C 2 H 5 O) 3 .
10. A process for the preparation of a hydrolysable silane of the formula R a R′ 3-a Si-A-OC(O)-(Az)-Z as defined in claim 1 , characterised in that a substituted alkyl 2,3-dibromopropionate of the formula R a R′ 3-a Si-A-OC(O)—CHBr—CH 2 Br is reacted with an amine of the formula Z—NH 2 .
11. A substituted alkyl 2,3-dibromopropionate of the formula R a R′ 3-a Si-A-OC(O)—CHBr—CH 2 Br, wherein R represents a hydrolysable group; R′ represents a hydrocarbyl group having 1 to 8 carbon atoms; a has a value in the range 1 to 3 inclusive; and A represents a divalent organic spacer linkage having at least one carbon atom.