Rubber composition suitable for use as a cap ply in a tire
AssigneeBridgestone Americas Tire Operations, LLC
InventorsNatalie Weingart, David R. Stewart, Jamie J. McNutt, Tomohiro Kusano
Life of this patent
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Abstract
Disclosed is a rubber composition suitable for use as a cap ply rubber composition. The rubber composition comprises: (a) at least one natural or synthetic rubbery polymer; (b) from 0.1 to 20 phr of at least one hydrazide compound; (c) from 0.1 to 10 phr of at least one methylene donor; (d) from 0.1 to 10 phr of at least one methylene acceptor resin; and (e) from 0.1 to 10 phr of zinc oxide. A method of making the same is also disclosed.
Claims21
1-15. (canceled)
A cap ply rubber composition comprising:
- (a) at least one natural or synthetic rubbery polymer;
- (b) from 0.1 to 20 phr of at least one hydrazide compound;
- (c) from 0.1 to 10 phr of at least one methylene donor;
- (d) from 0.1 to 10 phr of at least one methylene acceptor resin;
- and
- (e) from 0.1 to 10 phr of zinc oxide.
The cap ply rubber composition of claim 1, wherein the cap ply rubber composition has a tan δ value, measured at 60° C., a 1% strain amplitude and a frequency of 52 Hz of at least 0.01 lower than a comparative composition lacking any hydrazide compound.
The cap ply rubber composition of claim 2, wherein the at least one hydrazide compound comprises 3-hydroxy-N′-(1,3-dimethylbutylidene)-2-naphthoic acid hyrazide.
The cap ply rubber composition of claim 1, wherein the rubbery polymer is selected from the group consisting of polyisoprene, polybutadiene, styrene-butadiene rubber, and combinations thereof.
The cap ply rubber composition of claim 1, wherein the methylene donor is selected from the group consisting of hexamethoxymethylmelamine, hexamethylenetetramine, methoxymethyl melamine, N,N′N″-trimethyl N,N′N″-trimethylolmelamine, hexamethylomelamine, N,N′N″-dimethylolmelamine, N-methylolmelamine, N,N′-dimethylolmelamine, N,N′N″-tris(methoxymethyl)melamine, N,N′N″-tributyl-N,N′N″-trimethyloi-melamine, hexaethoxymethylmelamine, and mixtures thereof.
The rubber composition of claim 1, wherein the methylene acceptor resin is selected from the group consisting of resorcinol, resorcinolic derivatives, monohydric phenols and derivatives thereof, dihydric phenols and derivatives thereof, polyhydric phenols and derivatives thereof, unmodified phenol novolak resins, modified phenol novolak resin, novolak resins, and mixtures thereof.
The cap ply rubber composition of claim 1, wherein the zinc oxide is present in a total amount ranging from 1 to 5 phr, and wherein a portion of the zinc oxide is added in a non-productive mixing stage and the remaining portion of zinc oxide is added in a productive mixing stage.
The cap ply rubber composition of claim 1, wherein said cap ply rubber composition is void of a polymaleimide.
A method for reducing hysteresis in a tire utilizing a cap ply comprising at least one cord layer coated with a skim rubber composition, where the skim rubber composition is made by a process comprising:
- (a) mixing at least one natural or synthetic rubbery polymer with;
- (b) from 0.1 to 20 phr of at least one hydrazide compound;
- (c) from 0.1 to 10 phr of at least one methylene donor;
- (d) from 0.1 to 10 phr of at least one methylene acceptor resin;
- and
- (e) from 0.1 to 10 phr of zinc oxide
- wherein a portion of the zinc oxide is mixed in a non-productive mixing stage and the remaining portion of zinc oxide is mixed in a productive mixing stage.
The method of claim 9, wherein the fiber cord layer comprises fiber cords comprised of nylon, polyester, aramid, polyamine, or rayon.
The method of claim 9, wherein the at least one hydrazide compound comprises 3-hydroxy-N′-(1,3-dimethylbutylidene)-2-naphthoic acid hyrazide.
The method of claim 9, wherein the skim rubber composition has a tan δ value, measured at 60° C., a 1% strain amplitude and a frequency of 52 Hz of at least 0.01 lower than a comparative composition lacking any hydrazide compound.
The method of claim 9, wherein the rubbery polymer is selected from the group consisting of polyisoprene, polybutadiene, styrene-butadiene rubber, and combinations thereof.
The method of claim 9, wherein the methylene donor is selected from the group consisting of hexamethoxymethylmelamine, hexamethylenetetramine, methoxymethyl melamine, N,N′N″-trimethyl N,N′N″-trimethylolmelamine, hexamethylomelamine, N,N′N″-dimethylolmelamine, N-methylolmelamine, N,N′-dimethylolmelamine, N,N′N″-tris(methoxymethyl)melamine, N,N′N″-tributyl-N,N′N″-trimethyloi-melamine, hexaethoxymethylmelamine, and mixtures thereof.
The method of claim 9, wherein the methylene acceptor resin is selected from the group consisting of resorcinol and derivatives thereof, monohydric phenols and derivatives thereof, dihydric phenols and derivatives thereof, polyhydric phenols and derivatives thereof, unmodified phenol novolak resins, modified phenol novolak resin, novolak resins, and mixtures thereof.
A method for preparing a rubber composition comprising mixing:
- (a) at least one natural or synthetic rubbery polymer;
- (b) from 0.1 to 20 phr of at least one hydrazide compound;
- (c) from 0.1 to 10 phr of at least one methylene donor;
- (d) from 0.1 to 10 phr of at least one methylene acceptor resin;
- and
- (e) from 0.1 to 10 phr of zinc oxide;
- wherein a portion of the zinc oxide is mixed in a non-productive mixing stage and the remaining portion of zinc oxide is mixed in a productive mixing stage.
Dependencies are inferred from the claim text.