Wear resistant belts, and a process for their manufacture

1. A toothed power transmission belt having a tensile-loaded body portion composed of an elastomeric material, a plurality of spaced teeth bonded with and disposed along at least the inner periphery of the body portion, a fabric cover element having voids therein and positioned intimately along at least a portion of the outer surface of said body portion's inner periphery, made according to the method characterized in that:

a) said fabric cover element is immersed in a first treatment composition containing at least one cross-linkable component, to effect a pick-up rate of from about 1% to about 25%, based on the dry fabric weight to fill only a portion of said voids;

b) a wear-resistant composite comprising at least one binder constituent and at least one friction-modifying constituent is applied to a first surface of said fabric cover element forming the power transmitting surface of said belt, to fill a portion of said voids at said first surface;

c) the fabric cover element is applied to the outer surface of said belt; and

d) the belt is vulcanized;

and further characterized in that said wear-resistant composite comprising at least one friction-modifying constituent penetrates at least a portion of the total thickness of the fabric cover element, and is substantially separated from the elastomeric belt body by a boundary, and that the binder is abrasion-resistart.

2. The power transmission belt of claim 1 wherein said boundary comprises at least one of said first treatment composition and a second treatment material containing at least one cross-linkable constituent.

3. The power transmission belt of claim 1 wherein said boundary comprises said fabric cover element, said fabric cover element possessing a weave, a warp and weft yarn type and a warp and weft yarn quantity, which define a porosity, said porosity being characterized in that said composite penetrates less than the entire thickness of said fabric cover element.

4. The power transmission belt of claim 1 further comprising the step of applying at least one additional rubber bonding adhesive composition to a second surface of the fabric cover element opposite the power transmitting surface, prior to said vulcanization.

5. A toothed power transmission belt comprising a fabric cover element positioned intimately along at least a portion of the outer surface of an elastomeric belt body, said fabric cover element characterized by a generally alternating arrangement of yarns and voids; a wear-resistant composite comprising at least one binder constituent and at least one friction-modifying constituent bonded to at least a first surface of said fabric cover element forming a power transmitting surface of the belt; and characterized in that:

said fabric cover element bears a first coating of a first treatment composition containing at least one cross-linkable component contained within only a portion of said voids and present on said yarns in an amount from about 1% to about 25% based on the dry fabric weight;

the binder constituent possesses abrasion resistance; and

at least a portion of said wear-resistant composite is present as a second coating within at least a portion of the total thickness of said fabric cover element such that at least a portion of said friction-modifying constituent resides within a portion of said voids in said fabric cover element, and is separated from at least a portion of said binder constituent by a boundary; and at least a portion of said wear-resistant composite is polymerized and exhibits flexibility approaching or exceeding 100% extension.

6. The power transmission belt of claim 5 further comprising a boundary between at least a portion of said friction-modifying constituent and said body portion.

7. The power transmission belt of claim 5 wherein the wear-resistant composite resides within only a portion of the total thickness of the fabric cover element, on the power-transmitting surface of the belt, with the portion of the fabric cover element making contact with the elastomeric belt body being substantially free of the wear-resistant composite.

8. A toothed power transmission belt adapted to mate with a pulley, comprising an elastomeric belt body;

a porous fabric cover element comprised of yarns formed of individual fibers producing interstitial spaces and voids, having one side joined to the belt body; and the opposite side forming a power-transmitting surface adapted to drive or be driven by the pulley;

a first treatment composition containing at least one cross-linkable component coating the fabric cover element, and present on said yarns in an amount from about 1% to about 25% based on the dry fabric weight, such that a portion of the voids or interstitial spaces formed between the individual fibers and yarns of the fabric cover element remain free of the first composition;

a wear-resistant composite comprising at least one abrasion-resistant binder constituent and at least one friction-modifying constituent residing within such voids or interstitial spaces within only a portion of the total thickness of the fabric cover element, on the power-transmitting side of the belt; and

a second composition containing at least one cross-linkable material, residing at the one side of the fabric cover element adjacent the belt body, and constituting a boundary separating the wear-resistant composite from the belt body.

9. The power transmission belt of claim 8 wherein an adhesive is positioned between and joins the second composition and the belt body.

10. The power transmission belt of claim 8 wherein one or both of the and second compositions are formed of resorcinol formaldehyde latex.

11. The power transmission belt of claim 8 wherein the wear-resistant composite is a dispersion of a fluoropolymer in the abrasion-resistant binder.

12. The power transmission belt of claim 8 wherein the wear-resistant composite exhibits substantial flexibility approaching or exceeding 100% extension.