Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – Processes of preparing a desired or intentional composition...
Reexamination Certificate
1999-10-11
2001-04-24
Seidleck, James J. (Department: 1711)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
Processes of preparing a desired or intentional composition...
C152S209100, C152S525000, C152S547000, C152S564000
Reexamination Certificate
active
06221936
ABSTRACT:
FIELD OF THE INVENTION
This invention relates generally to rubber treads for pneumatic vehicle tires. It relates more specifically to a pneumatic tire with a tread composed of at least one sulfur-cured rubbery polymer and from about 1 phr to about 20 phr of uintahite.
BACKGROUND OF THE INVENTION
A pneumatic tire is a polymeric composite and is a complex system of interacting components, each with specific properties for maximum effectiveness. One of the more important components of a tire is the tread. Since the tread of a tire comes into contact with the road, it is particularly compounded for good traction, good wear characteristics and low rolling resistance. To achieve this combination of properties, blends of various rubbers and other materials (such as fillers, resins, oils and antioxidants) are conventionally used in compounding the tread rubber. The tread of an automobile passenger tire is generally composed of a blend of styrene-butadiene rubber and cis-1,4-polybutadiene rubber. The tread of automobile passenger tires can also contain a wide variety of other rubbery polymers, such as medium vinyl-1,2-polybutadiene rubber, high vinyl-1,2-polybutadiene rubber, 3,4-polyisoprene rubber, isoprene-butadiene rubber, styrene-isoprene rubber and styrene-isoprene-butadiene rubber. Treads for truck and aircraft tires are normally composed of natural rubber or synthetic polyisoprene rubber in blends with synthetic elastomers, such as styrene-butadiene rubber and polybutadiene rubber. However, tread rubbers used in truck and aircraft tires can also contain a wide variety of other rubbery polymers.
It is also important for many tires to exhibit good tear and puncture resistance. This is, of course, because the tire can come into contact with sharp objects and should be capable of resisting puncture or tear. For instance, farm tractor tires frequently run over sharp corn stalks and rocks with sharp edges and should be highly resistant to being punctured by such objects. Earthmover tires also encounter a wide variety of sharp objects at construction sites and must exhibit a high level of resistance to being punctured or torn. Off-the-road tires for trucks and four-wheel-drive vehicles also need to have treads that are highly resistant to tears and punctures.
SUMMARY OF THE INVENTION
This invention is based upon the unexpected discovery that uintahite can be incorporated into tire tread rubber to improve the physical properties thereof. By incorporating uintahite into tire tread rubber compositions, tires with improved tear and puncture resistance can be manufactured. Since uintahite is a relatively low cost material, its incorporation into tires also reduces cost. This is especially true in cases where uintahite is used to replace much more expensive materials, such as gum rosin. Cost reduction is also, of course, realized by simply adding the inexpensive uintahite to standard tire rubber formulations.
This invention more specifically discloses a pneumatic tire which is comprised of a generally toroidal-shaped carcass, an outer circumferential tread which is adapted to be ground contacting, two spaced beads and two sidewalls extending radially from said spaced beads and connecting said tread to said spaced beads, wherein said tread is comprised of at least one rubbery polymer and from about 1 phr to about 20 phr of uintahite. Such a pneumatic tire that has a uintahite containing tread exhibits improved resistance to tears and punctures.
The subject invention further discloses a pneumatic tire having an outer circumferential tread wherein said tread is a sulfur-cured rubber composition which is comprised of at least one rubbery polymer and from about 1 to about 20 phr of uintahite. The sulfur-cured rubber composition will typically be one or more polydiene rubbers; such as, natural rubber, synthetic polyisoprene rubber, styrene-butadiene rubber, cis-1,4-polybutadiene rubber, medium vinyl-1,2-polybutadiene rubber, high vinyl-1,2-polybutadiene rubber, 3,4-polyisoprene rubber, isoprene-butadiene rubber, styrene-isoprene rubber or styrene-isoprene-butadiene rubber.
The present invention also reveals a sulfur-cured tire rubber composition which is comprised of at least one rubbery polymer and from about 1 phr to about 20 phr of uintahite. Sulfur-cured rubber compositions of this type will normally be employed as tire tread compounds. They can additionally be used in tire sidewall, apex, chafer, bead coat, toeguard, innerliner, ply coat, gum strip, coverstrip, overlay or wedge stock compounds.
The sulfur-cured tire rubber compositions of this invention typically do not contain any crosslinked fatty acids or any starch. In other words, the sulfur-cured tire rubber compositions of this invention are typically void of crosslinked fatty acids and also typically void of starch. Thus, the present invention further reveals a sulfur-cured tire rubber composition which is comprised of at least one rubbery polymer and from about 1 phr to about 20 phr of uintahite, wherein the sulfur-cured tire rubber composition is free of crosslinked fatty acids. The subject invention also discloses a sulfur-cured tire rubber composition which is comprised of at least one rubbery polymer and from about 1 phr to about 20 phr of uintahite, wherein the sulfur-cured tire rubber composition is free of starch.
REFERENCES:
patent: 6011093 (2000-01-01), Maly et al.
Bryson Jay Gordon
Maly Neil Arthur
Asinovsky Olga
Seidleck James J.
The Goodyear Tire & Rubber Company
LandOfFree
Tire tread rubber containing uintahite does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Tire tread rubber containing uintahite, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Tire tread rubber containing uintahite will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2473162