Functional diene polymers, their method of preparation and their use in silica-filled elastomeric compositions which can be used for tires
AssigneeCompagnie Generale des Establissements Michelin-Michelin & Cie
InventorsJean-Noel Gorce, Gerard Labauze
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Abstract
A sulfur-vulcanizable rubber composition of improved hysteresis, comprising ilica as reinforcing filler as well as a diene polymer functionalized with a functionalizing agent having the general formula (Y).sub.m --R.sup. --Si(OR.sup.2).sub.3-n --R.sup.3 n and suitable to be used for the manufacture of tires of reduced resistance to rolling. The functionalized diene polymers are prepared by addition to the living diene polymer under suitable mixing conditions of an amount of functionalizing agent such that the molar ratio of functionalizing agent to the number of active sites is equal to or greater than 1.
Claims24
A process of preparing diene polymers functionalized by means of an epoxidized alkoxysilane compound said functionalized polymers having the general formula (Y).sub.m --R.sup.1 --Si(OR.sup.2).sub.2 --P in which P is the chain of a diene polymer, said process consisting in preparing by catalysis with a polymerization initiator, a living diene polymer and characterized by the fact that there is added, by mixing, to the living polymer a functionalizing agent having the general formula:
- (Y).sub.m --R.sup.1 --Si(OR.sup.2).sub.3-n --R.sup.3 n
- in which
- Y represents the radical ##STR3## R.sup.1 represents an alkyl, cycloalkyl, or aryl radical having from 1 to 10 carbon atoms,
- R.sup.2 represents an alkyl, aryl, cycloalkyl, alkaryl, or aralkyl radical having from 1 to 12 carbon atoms,
- R.sup.3 represents an alkyl, aryl or alkaryl radical having from 1 to 12 carbon atoms,
- R.sup.4 represents a hydrocarbon radical having from 1 to 6 carbon atoms and which may comprise one or more oxygen atoms in the hydrocarbon chain,
- n is a whole number selected from among the values 0 and 1,
- m is a whole number selected from among the values 1 and 2,
- p and q are whole numbers selected from among the values 0, 1, 2, 3 and 4, it being understood that the sum of p+q must represent a whole number between 2 and 5 inclusive, in an amount such that the molar ratio (MR) of functionalizing agent to number of active sites of the initiator is equal to or greater than 1;
- that the agent and the living polymer are allowed to react;
- and that the functionalized polymer is recovered.
A sulfur-vulcanizable rubber composition having the base of a functionalized diene polymer, said functional diene polymer having the general formula (Y).sub.m --R.sup.1 --Si(OR.sup.2).sub.2 --P in which P is the chain of a diene polymer, said composition characterized by the fact that it comprises silica as reinforcing filler and by the fact that the diene polymer is a polymer functionalized with a functionalizing agent having the general formula:
- (Y).sub.m --R.sup.1 --Si(OR.sup.2).sub.3-n --R.sup.3 n
- in which
- Y represents the radical ##STR4## R.sup.1 represents an alkyl, cycloalkyl or aryl radical having from 1 to 10 carbon atoms,
- R.sup.2 represents an alkyl, aryl, cycloalkyl, alkaryl or aralkyl radical having from 1 to 12 carbon atoms,
- R.sup.3 represents an alkyl, aryl or alkaryl radical having from 1 to 12 carbon atoms,
- R.sup.4 represents a hydrocarbon radical having from 1 to 6 carbon atoms and which may comprise one or more oxygen atoms in the hydrocarbon chain,
- n is a whole number selected from among the values 0 and 1,
- m is a whole number selected from among the values 1 and 2,
- p and q are whole numbers selected from among the values 0, 1, 2, 3 and 4, it being understood that the sum of p+q must represent a whole number between 2 and 5 inclusive, which simultaneously satisfies the two relationships:
- ##EQU3## in which:
- Ns represents the number of moles of silicon bound to one polymer chain end of the functionalized polymer,
- Np represents the number of polymer moles before functionalization,
- f(n) represents the functionality of the polymerization initiator,
- Ne represents the number of moles of epoxy function bound to a polymer chain end of the functionalized polymer,
- m has the meaning indicated above.
A tire tread, characterized by the fact that it comprises silica as reinforcing filler and a functionalized diene polymer having the general formula (Y).sub.m --R.sup.1 --Si(OR.sup.2).sub.2 --P in which P is the chain of a diene polymer, and in which the diene polymer is functionalized with a functionalizing agent having the general formula
- (Y).sub.m --R.sup.1 --Si(OR.sup.2).sub.3-n --R.sup.3 n
- in which
- Y represents the radical ##STR5## R.sup.1 represents an alkyl, cycloalkyl or aryl radical having from 1 to 10 carbon atoms,
- R.sup.2 represents an alkyl, aryl, cycloalkyl, alkaryl or aralkyl radical having from 1 to 12 carbon atoms,
- R.sup.3 represents an alkyl, aryl or alkaryl radical having from 1 to 12 carbon atoms,
- R.sup.4 represents a hydrocarbon radical having from 1 to 6 carbon atoms and which may comprise one or more oxygen atoms in the hydrocarbon chain,
- n is a whole number selected from among the values 0 and 1,
- m is a whole number selected from among the values 1 and 2,
- p and q are whole numbers selected from among the values 0, 1, 2, 3 and 4, it being understood that the sum of p+q must represent a whole number between 2 and 5 inclusive, which simultaneously satisfies two relationships:
- ##EQU4## in which:
- Ns represents the number of moles of silicon bound to one polymer chain end of the functionalized polymer,
- Np represents the number of polymer moles before functionalization,
- f(n) represents the functionality of the polymerization initiator,
- Ne represents the number of moles of epoxy function bound to a polymer chain end of the functionalized polymer,
- m has the meaning indicated above.
A tire having a reduced resistance to rolling, characterized by the fact that it has a tread comprising silica as filler and a functionalized diene polymer having the general formula (Y.sub.m)--R.sup.1 --Si(OR.sup.2).sub.2 --P in which P is the chain of a diene polymer and in which the diene polymer is functionalized with a functionalizing agent having the general formula
- (Y).sub.m --R.sup.1 --Si(OR.sup.2).sub.3-n --R.sup.3 n
- in which
- Y represents the radical ##STR6## R.sup.1 represents an alkyl, cycloalkyl or aryl radical having from 1 to 10 carbon atoms,
- R.sup.2 represents an alkyl, aryl, cycloalkyl, alkaryl or aralkyl radical having from 1 to 12 carbon atoms,
- R.sup.3 represents an alkyl, aryl or alkaryl radical having from 1 to 12 carbon atoms,
- R.sup.4 represents a hydrocarbon radical having from 1 to 6 carbon atoms and which may comprise one or more oxygen atoms in the hydrocarbon chain,
- n is a whole number selected from among the values 0 and 1,
- m is a whole number selected from among the values 1 and 2,
- p and q are whole numbers selected from among the values 0, 1, 2, 3 and 4, it being understood that the sum of p+q must represent a whole number between 2 and 5 inclusive, which simultaneously satisfies the two relationships:
- ##EQU5## in which:
- Ns represents the number of moles of silica bound to a polymer chain end of the functionalized polymer,
- Np represents the number of polymer moles before functionalization,
- f(n) represents the functionality of the polymerization initiator,
- Ne represents the number of moles of epoxy function bound to a polymer chain end of the functionalized polymer,
- m has the meaning indicated above.
Dependencies are inferred from the claim text.