V-ribbed belt and method for producing same
A V-ribbed belt includes a compression rubber layer containing a vulcanizate of a rubber composition, a tension member, and a tension layer, and has a side part of the compression rubber layer being a ground surface coming into contact with pulleys, and a bottom part of the compression rubber layer being a non-ground surface not coming into contact with pulleys. The V-ribbed belt has, on a surface of the bottom part, a composite layer containing a fiber assembly and a vulcanizate. The fiber assembly contains a heat-resistant fiber which is not melted at a vulcanization temperature of the rubber composition and has a weight per unit area of 25 g/m 2 or less. The vulcanizate of the rubber composition impregnated among fibers of the fiber assembly.
1. A V-ribbed belt comprising:
a compression rubber layer containing a vulcanizate of a rubber composition, and having a side part being a ground surface coming into contact with pulleys and a bottom part being a non-ground surface not coming into contact with pulleys;
a tension member;
a tension layer; and,
a composite layer, on a surface of the bottom part, containing a fiber assembly that contains a heat-resistant fiber which is not melted at a vulcanization temperature of the rubber composition, and that has a weight per unit area of 8 to 20 g/m 2 , and a vulcanizate of the rubber composition impregnated among fibers of the fiber assembly,
wherein the heat-resistant fiber contains a long fiber,
wherein the compression rubber layer forms a continuous phase with the vulcanizate of the rubber composition.
2. The V-ribbed belt according to claim 1 , wherein the heat-resistant fiber contains a polyester fiber.
3. The V-ribbed belt according to claim 1 , wherein the fiber assembly has a nonwoven fiber structure.
4. The V-ribbed belt according to claim 1 , wherein the heat-resistant fiber has an average fiber diameter of 1 to 50 μm.
5. The V-ribbed belt according to claim 1 , wherein the heat-resistant fibers are not fused with each other.
6. The V-ribbed belt according to claim 1 , wherein the compression rubber layer contains a short fiber.
7. The V-ribbed belt according to claim 1 , wherein the fiber assembly has a nonwoven fiber structure, the heat-resistant fiber is oriented in a predetermined direction, and a longitudinal direction of the heat-resistant fiber is in parallel to a longitudinal direction of the belt.
8. The V-ribbed belt according to claim 1 , wherein the compression rubber layer has a rib part, and the rib part has an average thickness of 54% or less relative to an average thickness of the entire V-ribbed belt.
9. A production method of the V-ribbed belt according to claim 1 , the method comprising:
attaching a tension layer member for forming a tension layer in a cylindrical drum;
winding a cord as a tension member;
winding an unvulcanized rubber sheet for forming a compression rubber layer;
winding a fiber assembly containing a heat-resistant fiber on the wound unvulcanized rubber sheet;
vulcanizing a belt molded body obtained by the attaching, winding the cord, winding the unvulcanized rubber sheet, and winding the fiber assembly to obtain a vulcanized belt sleeve; and
grinding only a side part of the compression rubber layer on a fiber assembly side of the vulcanized belt sleeve to achieve molding.
10. The production method according to claim 9 , wherein the fiber assembly has an average thickness of 0.03 to 0.15 mm.