Process for preparing polymers and compositions thereof
AssigneeThe Lubrizol Corporation
InventorsMarina Baum, Barton J. Schober, Mark Davies, Daniel C. Visger, John R. Johnson
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Abstract
The present invention provides a process for preparing a polymer, employing the steps of: (1) contacting a free radical initiator; a chain transfer agent containing a thiocarbonyl thio group and a free radical leaving group; and a radically polymerisable monomer, to form a polymer chain; and (2) contacting the polymer chain of step (1) with at least one of a polyvalent coupling agent, a polymerization inhibitor, a grafting acylating agent, an amine and an oil of lubricating viscosity. The invention further provides compositions and uses for the polymer.
Claims20
A process for preparing a polymer and a lubricating composition thereof, comprising the steps of:
- (1) contacting:
- (i) a free radical initiator;
- (ii) a chain transfer agent containing a thiocarbonyl thio group and a free radical leaving group;
- and
- (iii) a radically polymerisable monomer, to form a polymer chain;
- wherein the process of step (1) is a controlled radical polymerisation process with living characteristics;
- and at least about 50% of the polymer chains from step (1) contain a reactive end group capable of reacting with a polyvalent coupling agent;
- (2) contacting the polymer prepared by step (1) with a polyvalent coupling agent to form a star-polymer,
- wherein the star-polymer is a block-arm star polymer or a hetero-arm star polymer;
- and
- wherein the star polymer is derived from at least two monomers comprising:
- (a) at least 50 wt % of a mixture of C12 to C15 alkyl substituted (meth)acrylate monomers;
- and
- (b) less than 50 wt % of an alkyl (meth)acrylate monomer containing 1 to 30 carbon atoms in the alkyl group, other than the C12 to C15 alkyl substituted (meth)acrylate monomer;
- (c) optionally containing less than 20 wt % styrene;
- and
- (d) optionally containing less than 10 wt % alkyl (meth)acrylamide,
- and wherein the star-polymer has about 2 to about 50 arms present on the star polymer;
- (3) optionally contacting the polymer prepared by step (1) or step (2) with a polymerisation inhibitor;
- and
- (4) mixing the polymer prepared by step (2) or step (3) with an oil of lubricating viscosity to form a lubricating composition.
A process for preparing a polymer and a lubricating composition thereof, comprising the steps of:
- (1) contacting:
- (i) a free radical initiator;
- (ii) a chain transfer agent containing a thiocarbonyl thio group and a free radical leaving group;
- and
- (iii) a radically polymerisable monomer, to form a polymer chain;
- wherein the process of step (1) is a controlled radical polymerisation process with living characteristics;
- and at least about 50% of the polymer chains from step (1) contain a reactive end group capable of reacting with a polyvalent coupling agent;
- (2) contacting the polymer prepared by step (1) with a polyvalent coupling agent of the general formula:
- W—(Y)n
- where
- Y is a functionality capable of covalently reacting with an alkyl radical or an oxygen-centered radical;
- W is a hydrocarbyl group;
- and
- n=2 or more to form a star-polymer,
- wherein the star polymer is derived from at least two monomers comprising:
- (a) at least 50 wt % of a mixture of C12 to C15 alkyl substituted (meth)acrylate monomers;
- and
- (b) less than 50 wt % of an alkyl (meth)acrylate monomer containing 1 to 30 carbon atoms in the alkyl group, other than the C12 to C15 substituted alkyl (meth)acrylate monomer;
- (c) optionally containing less than 20 wt % styrene;
- and
- (d) optionally containing less than 10 wt % alkyl (meth)acrylamide,
- and wherein the star-polymer has about 2 to about 50 arms present on the star polymer;
- (3) optionally contacting the polymer prepared by step (1) or step (2) with a polymerisation inhibitor;
- and
- (4) mixing the polymer prepared by step (2) or step (3) with an oil of lubricating viscosity to form a lubricating composition.
Dependencies are inferred from the claim text.