Halogenated wax grafted to low molecular weight polymer
A wax-polymer compound includes (a) a polymer component that is a polymerized unsaturated monomer, optionally copolymerized with a vinyl-aromatic monomer, and (b) a halogenated hydrocarbon wax component. The polymer component is grafted to the halogenated hydrocarbon wax component, and the wax-polymer compound has a number average molecular weight of about 1,000 to about 100,000. A method of making the wax-polymer compound and a coated silica particle are also disclosed.
1. A tire component comprising:
a rubber elastomer comprising a polymerized unsaturated monomer and optionally a polymerized vinyl-aromatic monomer, the rubber elastomer having a number average molecular weight of about 100,000 to about 1,000,000;
a filler in an amount of about 5 to about 200 phr, the filler comprising carbon black, silica, or both; and
a wax-polymer additive that includes:
(a) a polymer component that is a polymerized unsaturated monomer, optionally copolymerized with a vinyl-aromatic monomer, and
(b) a halogenated hydrocarbon wax component;
the polymer component being grafted to the halogenated hydrocarbon wax component, the wax-polymer additive having a number average molecular weight of about 1,000 to about 100,000.
2. The tire component of claim 1 , wherein the filler comprises silica.
3. The tire component of claim 1 , wherein the tire component is a tire tread.
4. The tire component of claim 1 , wherein the halogenated hydrocarbon wax component is a solid at 0° C.
5. The tire component of claim 1 , wherein a number average molecular weight of the polymer component is about 500 to about 20,000.
6. The tire component of claim 1 , wherein the wax component comprises a branched or unbranched C 20 to C 40 alkane wax.
7. The tire component of claim 1 , wherein the polymer component is grafted to the halogenated hydrocarbon wax component at more than one graft location.
8. The tire component of claim 1 , wherein the halogenated hydrocarbon wax component is halogenated along a hydrocarbon chain backbone of the wax.
9. The tire component of claim 1 , wherein the rubber elastomer comprises a styrene-butadiene rubber.
10. The tire component of claim 1 , wherein the polymer component is copolymerized with the vinyl-aromatic monomer.
11. The tire component of claim 1 , further comprising about 5 phr or less of processing oil and the filler includes carbon black, wherein the tire component, pre-vulcanization, has a Mooney viscosity (ML1+4, 103° C., RPA) of about 20 to about 60.
12. The tire component of claim 1 , wherein the filler includes carbon black, and the tire component has a bound rubber content of about 31% to about 50%.
13. A method for making a composition comprising:
mixing:
a rubber elastomer comprising a polymerized unsaturated monomer and optionally a polymerized vinyl-aromatic monomer, the elastomer having a number average molecular weight of about 100,000 to about 1,000,000;
a filler in an amount of about 5 to about 200 phr, the filler comprising carbon black, silica, or both;
a wax-polymer additive that includes:
(a) a polymer component that is a polymerized unsaturated monomer, optionally copolymerized with a vinyl-aromatic monomer, and
(b) a halogenated hydrocarbon wax component,
the polymer component grafted to the halogenated hydrocarbon wax component, the wax-polymer additive having a number average molecular weight of about 1,000 to about 100,000; and
curing the composition.
14. The method of claim 13 , wherein the halogenated hydrocarbon wax component is present in a ratio with the polymer component in a range of about 1:1 to about 1:20.
15. The method of claim 13 , wherein the polymer component comprises two or more polymer chains that are bonded to a single halogenated hydrocarbon wax.
16. The method of claim 13 , wherein the rubber elastomer comprises a styrene-butadiene rubber.
17. The method of claim 13 , wherein the curing step comprises vulcanizing.
18. The method of claim 13 , wherein the filler comprises silica.
19. The method of claim 13 , wherein the polymer component is polymerized in the same container as the mixing of the wax-polymer compound.
20. A coated silica compound comprising:
silica coated with a wax-polymer compound, the wax-polymer compound comprising:
(a) a polymer component that is a polymerized unsaturated monomer, optionally copolymerized with a vinyl-aromatic monomer, and
(b) a halogenated hydrocarbon wax component;
the polymer component grafted to the halogenated hydrocarbon wax component, the wax-polymer compound having a number average molecular weight of about 1,000 to about 100,000.