Tire Compositions and Methods for Making Thereof
A tire composition is disclosed. The composition comprises a rubber component and based on 100 parts by weight (phr) of the rubber component, 50-200 phr of covered silica, with the covered silica comprising silica core and a first resin covering the silica core, wherein the first resin is not chemically bonded to the silica core. The silica core is covered with the first resin by mixing a slurry comprising silica core with a mixture containing the first resin as a solution, an aqueous dispersion; or a solution by dissolving the first resin in a solvent.
1 . A tire composition comprising a blend of:
a rubber component and based on 100 parts by weight (phr) of the rubber component;
from 50 phr to 200 phr of a resin-covered silica, wherein the covered silica comprises silica particulates coated with a first resin,
from 50 phr to 200 phr of at least one filler;
from 0 phr to 50 phr of a plasticizer; and
from 0 to 50 phr of a second resin,
wherein the first resin and the second resin are the same or different, and selected from the group consisting of coumarone-indene resin, petroleum hydrocarbon resin, terpene polymers, styrene-alpha-methylstyrene resins, terpene phenol resin, rosin derived resins and copolymers and mixtures thereof.
2 . The tire composition of claim 1 , wherein the silica core is coated with the first resin by
providing a slurry mixture comprising the first resin in any of a solution, an aqueous dispersion, or a solution by dissolving the first resin in a solvent;
mixing the slurry mixture comprising the silica particulates with the mixture comprising the first resin for the first resin to coat at least a surface of the silica particulates; and
drying the mixture to recover the resin-covered silica.
3 . The tire composition of claim 1 , comprising from 50 phr to 150 phr of covered silica.
4 . The tire composition of claim 1 , wherein the silica particulates comprise untreated, precipitated silica, crystalline silica, colloidal silica, aluminum silicates, calcium silicates, fumed silica, and mixtures thereof.
5 . The tire composition of claim 1 , wherein the silica particulates comprise precipitated silica having a CTAB specific surface area ranging from 60 to 200 m 2 /g.
6 . The tire composition of claim 1 , wherein the silica particulates comprise precipitated silica having a BET surface area, as measured using nitrogen gas, from 40 to 600 m 2 /g.
7 . The tire composition of claim 1 , wherein the first resin is a terpene resin comprising α-pinene, β-pinene, δ-3 carene, limonene, dipentene, β-phellandrene and pyrolysates of α-pinene, β-pinene, δ-3 carene, δ-2 carene, turpentine, dipentene, limonene, and combinations thereof.
8 . The tire composition of claim 1 , wherein the first resin comprises a terpene-based resin, an α-methyl styrene (“AMS”) resin, a rosin, a rosin ester-derived resin, or combinations thereof.
9 . The tire composition of claim 1 , wherein the terpene-based resin is selected from polyterpene resins and terpene phenol resins.
10 . The tire composition of claim 1 , wherein the first resin comprises petroleum resins.
11 . The tire composition of claim 10 , wherein the first resin comprises coumarone-indene resins, indene resins, aromatic vinyl polymers obtained by polymerizing α-methylstyrene and/or styrene, C9 hydrocarbon resins, resins derived from cyclopentadiene homopolymer or copolymer resins, dicyclopentadienehomopolymer or copolymer resins, C5 fraction homopolymer or copolymer resins, C9 fraction homopolymer or copolymer resins, alpha-methylstyrene homopolymer or copolymer resins, and combinations thereof.
12 . The tire composition of claim 1 , wherein the rubber component is selected from the group of natural rubber (NR), styrene-butadiene rubber (SBR), butadiene rubber (BR), synthetic polyisoprene rubber, epoxylated natural rubber, polybutadiene rubber, nitrile-hydrogenated butadiene rubber NHBR, hydrogenated styrene-butadiene rubber HSBR, ethylene propylene diene monomer rubber, ethylene propylene rubber, maleic acid-modified ethylene propylene rubber, butyl rubber, isobutylene-aromatic vinyl or diene monomer copolymers, brominated-NR, chlorinated-NR, brominated isobutylene p-methylstyrene copolymer, chloroprene rubber, epichlorohydrin homopolymers rubber, epichlorohydrin-ethylene oxide or allyl glycidyl ether copolymer rubbers, epichlorohydrin-ethylene oxide-allyl glycidyl ether terpolymer rubbers, chlorosulfonated polyethylene, chlorinated polyethylene, maleic acid-modified chlorinated polyethylene, methylvinyl silicone rubber, dimethyl silicone rubber, methylphenylvinyl silicone rubber, polysulfide rubber, vinylidene fluoride rubbers, tetrafluoroethylene-propylene rubbers, fluorinated silicone rubbers, fluorinated phosphagen rubbers, styrene elastomers, thermoplastic olefin elastomers, polyester elastomers, urethane elastomers, and polyamide elastomers.
13 . The tire composition of claim 1 , wherein the tire composition has a reduction in rolling resistance expressed as tan δ at 60° C. of at least 3% less the tan δ at 60° C. of a composition with an equal amount of uncoated silica particulates and first resin, as separate components.
14 . The tire composition of claim 1 , wherein the tire composition has an increase in wet grip resistance expressed as tan δ at 0° C. of at least 5% more than the tan δ at 0° C. of a composition with an equal amount of uncoated silica particulates and first resin, as separate components.
15 . The tire composition of claim 1 , wherein the tire composition has a rolling resistance expressed as tan δ at 60° C. of less than 0.20 and a tan δ at 0° C. of at least 0.50.
16 . The tire composition of claim 1 , wherein the tire composition has DIN abrasion relative volume loss of less than 150 mm 3 .
17 . A method for preparing a tire rubber composition comprising:
providing 100 parts by weight (phr) of a rubber component
providing from 50 phr to 200 phr of a resin-covered silica, wherein the covered silica comprises silica particulates coated a resin selected from the group consisting of coumarone-indene resin, petroleum hydrocarbon resin, terpene polymers, styrene-alpha-methylstyrene resins, terpene phenol resin, rosin derived resins and copolymers and/or mixtures thereof;
optionally providing up to 50 phr of a plasticizer; and
mixing the rubber component, the resin covered silica, the optional plasticizer to form mixture;
thermomechanically kneading the mixture; and
incorporating a cross-linking system into the mixture forming a blend.
18 . The method of claim 17 , wherein the first resin comprises a terpene-based resin, an α-methyl styrene (“AMS”) resin, a rosin, a rosin ester-derived resin, or combinations thereof.
19 . The method of claim 17 , wherein providing the resin covered silica comprises:
providing a slurry mixture comprising the resin in any of a solution, an aqueous dispersion, or a solution by dissolving the resin in a solvent;
mixing the slurry mixture comprising the silica particulates with the mixture comprising the resin for the resin to coat at least a surface of the silica particulates; and
drying the mixture to recover the resin-covered silica.
20 . A tire made by the method of claim 17 .