초록

The invention relates to an endless vehicular rubber track designed for extreme cold temperature working environment. The invention particularly relates to such track having a combination of tread, supporting carcass and guide lug components of rubber compositions intended for such purpose.

대표청구항 ▼

1. An endless rubber track designed to encompass at least one drive wheel and at least one driven wheel wherein said track is comprised of:(A) an outer rubber tread component comprised of a plurality of spaced apart, raised lugs designed to be ground-contacting,(B) a unitary(1) rubber carcass compon

1. An endless rubber track designed to encompass at least one drive wheel and at least one driven wheel wherein said track is comprised of:(A) an outer rubber tread component comprised of a plurality of spaced apart, raised lugs designed to be ground-contacting,(B) a unitary(1) rubber carcass component integral with, underlying and supporting said tread component, and(2) a guide lug component comprised of a plurality of spaced apart rubber guide lugs positioned on and integral with the outer exposed surface of said carcass component, wherein said guide lugs are designed to be engaged and/or guided by one or more of said drive and driven wheels, wherein(a) said tread component is of a rubber composition exclusive of elastomers having a Tg higher than −50° C., which comprises, based upon 100 parts by weight elastomers (phr),(1) about 15 to about 40 phr of cis 1,4-polybutadiene elastomer having a Tg within a range of about −90° C. to about −115° C., and(2) about 85 to about 60 phr of cis 1,4-polyisoprene rubber having a Tg within a range of about −70° C. to about −80° C.,(3) about 38 to about 80 phr of reinforcing filler comprised of about 35 to about 65 phr of rubber reinforcing carbon black and about 3 to about 15 phr of aggregates of precipitated silica; and exclusive of a coupling agent having a moiety reactive with silanol groups on the surface of said silica and another moiety interactive with said elastomer(s),(4) sulfur curative in a range of about 0.75 to about 1.75 phr and a sulfenamide sulfur cure accelerator,(5) zero to about 10 phr of rubber processing oil selected from at least one of aromatic, naphthenic and paraffinic rubber processing oil and their mixtures, and wherein(b) said unitary carcass and said guide lug components are of a unitary rubber composition, exclusive of elastomers having a Tg higher than −50° C., comprised of, based on parts by weight per 100 parts by weight rubber (phr):(1) about 80 to about 100 phr of cis 1,4-polyisoprene natural rubber having a Tg within a range of about −70° C. to about −80° C., and(2) zero to about 20 phr of synthetic cis 1,4-polyisoprene rubber having a Tg within a range of about −70° C. to about −80° C.,(3) about 38 to about 75 phr of reinforcing filler comprised of about 35 to about 60 phr of rubber reinforcing carbon black and about 3 to about 15 phr of aggregates of precipitated silica, and a coupling agent having a moiety reactive with silanol groups on the surface of said silica and another moiety interactive with said elastomer(s),(4) sulfur curative in a range of about 0.75 to about 1.75 phr and a sulfenamide sulfur cure accelerator(5) zero to about 10 phr of rubber processing oil selected from at least one of aromatic, naphthenic and paraffinic rubber processing oil and their mixtures,(6) about 5 to about 10 phr of rubber plasticizer, other than an oil, wherein said plasticizer is selected from adipates, azelates, gluterates, oleates, hexoates, tallates and trimellitates, and their mixtures having a freeze (melt) point of lower than −45° C. 2. A sulfur-vulcanized track of claim 1. 3. The track of claim 2 wherein said carbon black for said tread component is selected from at least one of N220 and N234. 4. A vehicle having at least two endless rubber track systems, namely a track system on each side of the vehicle, for driving said vehicle over the ground, said track systems individually comprised of the track of claim 3, a plurality of wheels engaged with said vehicle and encompassed by said track wherein at least one of said wheels is a drive wheel. 5. The track of claim 2 wherein said antidegradant is selected from at least one of polymerized 2,2,4-trimethyl 1,2-dihydroquinoline, N-1,3-dimethylbutyl-N′-phenyl para-phenylenediamine and mixed aryl-p-phenylenediamines. 6. A vehicle having at least two endless rubber track syste ms, namely a track system on each side of the vehicle, for driving said vehicle over the ground, said track systems individually comprised of the track of claim 5, a plurality of wheels engaged with said vehicle and encompassed by said track; wherein at least one of said wheels is a drive wheel. 7. The track of claim 2 wherein said unitary carcass and drive lug rubber composition is exclusive of any of aromatic, naphthenic and paraffinic oil. 8. A vehicle having at least two endless rubber track systems, namely a track system on each side of the vehicle, for driving said vehicle over the ground, said track systems individually comprised of the track of claim 7, plurality of wheels engaged with said vehicle and encompassed by said track; wherein at least one of said wheels is a drive wheel. 9. The track of said claim 2 wherein said plasticizer is selected from at least one of alkyl alkyldiester adipate, diioctyl adipate, dioctyl adipate, polyester adipate, diisooctyl adipate, dioctyl azelate, dialkyl diether gluterate, dibutoxyethoxyethyl gluteratate, dibutoxyethyl glutarate, diisodecyl glutarate, alkyl oleate, butyl oleate, dioctyl sebacate, isooctyl tallate, triisooctyl trimellitate, trioctyl trimellitate, linear trimellitate, polyethylene glycol 400 di-2-ethylhexoate, tetraethylene glycol di-2-ethylhexoate, tetraethylene glycol di-2-ethyhlhexoate, and diisooctyl dodecanedioate, and their mixtures. 10. A vehicle having at least two opposing endless rubber track systems, namely a track system on each side of the vehicle, for driving said vehicle over the ground, said track systems individually comprised of the track of claim 2, a plurality of wheels engaged with said vehicle and encompassed by said track wherein at least one of said wheels is a drive wheel. 11. The track of claim 2 wherein said carcass and said guide lug components are of a unitary rubber composition, exclusive of elastomers having a Tg higher than −50° C., comprised of elastomers, based on parts by weight per 100 parts by weight rubber (phr), as:(A) about 85 to about 90 phr of cis 1,4-polyisoprene natural rubber having a Tg within a range of about −70° C. to about −80° C., and(B) about 15 to about 10 phr of synthetic cis 1,4-polyisoprene rubber having a Tg within a range of about −70° C. to about −80° C.