Sealant product, laminate thereof, and pneumatic tire constructed therewith
First Claim
1. A self-sealing pneumatic tire having an inner liner and a substantially fully cured generally flat, bare layer of puncture sealant in which all of a curative is used up to cure the sealant having high molecular weight to low molecular weight elastomers present in a weight ratio from greater than 1, to 10, and more processing aid than there is high molecular weight elastomer, so as to have before curing a peak Mooney viscosity at room temperature in the range from above 70 to about 110, said tire and sealant cured in a curing process, said cured sealant being adhered to at least a portion of said inner liner with edges of said sealant smoothly blended into the sidewalls of said tire without the sealant being restrained by any external restraining means, said cured sealant having its radially inward surface coated with a detackifier which is not a self-supporting film but remains on said surface after it is contacted with a curing bladder, said cured sealant having a peak Mooney viscosity at 150°
- F. in the range above 15 but below 30, which viscosity is high enough to negate flow of the sealant at a temperature up to 200°
F. and vehicle speeds up to 70 mph, on which vehicle the tire is mounted, yet low enough to permit a puncturing object when withdrawn, to draw sufficient sealant into the puncture it causes, so as to seal the puncture.
10 Assignments
0 Petitions
Accused Products
Abstract
A carcass for a self-sealing pneumatic tire is constructed by starting with an extruded thin flat strip of puncture sealant both surfaces of which are detackified. The strip is place on a building drum and its upper surface is wiped clean so that an inner liner may be adhered to it. Thereafter, the carcass is conventionally completed with superimposed successive layers of belts, and tread along with bead rings, etc. The carcass is then cured in a conventional curing press so that the sealant is cured by contact with the curing bladder. The curing sealant is not restrained in any way, but does not flow. Alternatively, a laminate of the sealant is formed with the inner liner, with only the exposed surface of the sealant detackified so that it adheres neither to the building drum nor to the curing bladder. The detackifier remains on the sealant. The recipe for this effective sealant product requires a ratio of high molecular weight elastomer to low molecular weight elastomer greater than 1; also, that there be at least as much, by weight processing aid as there is high mol wt elastomer. Such a recipe has a room temperature peak Mooney viscosity above 70, and, after curing, a peak Mooney viscosity at 150° F. in the range above 15 but below 30. A combination of homogenizer and tackifier facilitates maintaining the necessary viscosity of the uncured sealant recipe. The tire provides excellent self-sealing results.
65 Citations
10 Claims
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1. A self-sealing pneumatic tire having an inner liner and a substantially fully cured generally flat, bare layer of puncture sealant in which all of a curative is used up to cure the sealant having high molecular weight to low molecular weight elastomers present in a weight ratio from greater than 1, to 10, and more processing aid than there is high molecular weight elastomer, so as to have before curing a peak Mooney viscosity at room temperature in the range from above 70 to about 110, said tire and sealant cured in a curing process, said cured sealant being adhered to at least a portion of said inner liner with edges of said sealant smoothly blended into the sidewalls of said tire without the sealant being restrained by any external restraining means, said cured sealant having its radially inward surface coated with a detackifier which is not a self-supporting film but remains on said surface after it is contacted with a curing bladder, said cured sealant having a peak Mooney viscosity at 150°
- F. in the range above 15 but below 30, which viscosity is high enough to negate flow of the sealant at a temperature up to 200°
F. and vehicle speeds up to 70 mph, on which vehicle the tire is mounted, yet low enough to permit a puncturing object when withdrawn, to draw sufficient sealant into the puncture it causes, so as to seal the puncture. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
- F. in the range above 15 but below 30, which viscosity is high enough to negate flow of the sealant at a temperature up to 200°
Specification