Use of comb polymers for reducing fuel consumption
The present invention relates to the use of comb polymers comprising, in the main chain, repeat units which are derived from polyolefin-based macromonomers, and repeat units which are derived from low molecular weight monomers selected from the group consisting of styrene monomers having 8 to 17 carbon atoms, alkyl (meth)acrylates having 1 to 10 carbon atoms in the alcohol group, vinyl esters having 1 to 11 carbon atoms in the acyl group, vinyl ethers having 1 to 10 carbon atoms in the alcohol group, (di)alkyl fumarates having 1 to 10 carbon atoms in the alcohol group, (di)alkyl maleates having 1 to 10 carbon atoms in the alcohol group and mixtures of these monomers, where the molar degree of branching is in the range of 0.1 to 10 mol % and the comb polymer comprises a total of at least 80% by weight, based on the weight of the repeat units, of repeat units which are derived from polyolefin-based macromonomers and repeat units which are derived from low molecular weight monomers selected from the group consisting of styrene monomers having 8 to 17 carbon atoms, alkyl (meth)acrylates having 1 to 10 carbon atoms in the alcohol group, vinyl esters having 1 to 11 carbon atoms in the acyl group, vinyl ethers having 1 to 10 carbon atoms in the alcohol group, (di)alkyl fumarates having 1 to 10 carbon atoms in the alcohol group, (di)alkyl maleates having 1 to 10 carbon atoms in the alcohol group and mixtures of these monomers, for reducing the fuel consumption of vehicles.
1. An additive for reducing fuel consumption of a vehicle, comprising a comb polymer of repeat units comprising:
11-23 wt % of a hydrogenated polybutadiene macromonomer,
65-84 wt % of n-butyl methacrylate, and
up to 13 wt % of styrene,
wherein
the hydrogenated polybutadiene macromonomer is copolymerizable with the n-butyl methacrylate and styrene,
wt % is based on the total weight of the comb polymer, and
wherein
the comb polymer comprises a main chain and a side chain,
the main chain comprises copolymerized units of methacrylates and styrene,
a molar degree of branching of the comb polymer is 0.3-0.5 mol %,
a weight average molecular weight of the comb polymer is from 312,000 to 374,000 g/mol, and
a glass transition temperature of the main chain of the comb polymer is in the range of 0 to 90° C.
2. The additive according to claim 1 , wherein the comb polymer comprises:
8-15 wt % of the hydrogenated polybutadiene macromonomer,
68-84 wt % of n-butyl methacrylate,
styrene up to 13 wt %, and
further comprises up to 5 wt % of an alkyl methacrylate mixture having 12 to 14 carbon atoms in the alkyl groups.
3. The additive according to claim 1 , wherein the content of styrene is from 5 to 13% by weight.
4. A lubricant oil formulation comprising the additive according to claim 1 .
5. The lubricant oil formulation according to claim 4 , further comprising at least one base oil selected from the group consisting of API group I, II, III, IV and group V.
6. The lubricant oil formulation according to claim 4 , further comprising at least one additional additive.
7. The lubricant oil formulation according to claim 6 , wherein the additive is at least one selected from the group consisting of a viscosity index improver, a pour point improver, a dispersant, a detergent, a defoamer, a corrosion inhibitor, an antioxidant, an antiwear additive, an extreme pressure additive and a friction modifier.
8. The lubricant oil formulation according to claim 4 , wherein a difference between a high-temperature high-shear viscosity at 100° C. and 150° C. of the lubricant is from 2.5 to 4 mPA·s according to ASTM D 4683.
9. The additive of claim 2 , wherein the comb polymer consists of:
8-15 wt % of the hydrogenated polybutadiene macromonomer,
68-84 wt % of n-butyl methacrylate,
up to 13 wt % of styrene, and
up to 5 wt % of the alkyl methacrylate mixture having 12 to 14 carbon atoms in the alkyl groups.
10. The additive of claim 9 , wherein the comb polymer consists of:
11 wt % of a hydrogenated polybutadiene macromonomer having a Mn of 4,800 g/mol,
84 wt % of n-butyl methacrylate, and
5 wt % of an alkyl methacrylate mixture having 12 to 14 carbon atoms in the alkyl groups.
11. A lubricant oil formulation comprising:
the additive according to claim 2 ; and
at least one base oil selected from the group consisting of API group I, II, III, IV and group V;
wherein a difference between a high-temperature high-shear viscosity at 100° C. and 150° C. of the lubricant is from 2.5 to 4 mPA·s according to ASTM D 4683.
12. A lubricant oil formulation comprising:
the additive according to claim 9 ; and
at least one base oil selected from the group consisting of API group I, II, III, IV and group V;
wherein a difference between a high-temperature high-shear viscosity at 100° C. and 150° C. of the lubricant is from 2.5 to 4 mPA·s according to ASTM D 4683.
13. A lubricant oil formulation comprising:
the additive according to claim 10 ; and
at least one base oil selected from the group consisting of API group I, II, III, IV and group V;
wherein a difference between a high-temperature high-shear viscosity at 100° C. and 150° C. of the lubricant is from 2.5 to 4 mPA·s according to ASTM D 4683.