Friction transmission belt and manufacturing method therefor
A friction transmission belt has a rubber layer forming a pulley contacting portion. The rubber layer is made of a rubber composition containing a crosslinked rubber component and crosslinked polyolefin particles. Examples of the crosslinked polyolefin particles can contain ultrahigh molecular weight polyolefin particles having an average molecular weight of 500,000 or more.
1. A friction transmission belt comprising a rubber layer forming a pulley contacting portion, wherein
the rubber layer is made by crosslinking an uncrosslinked rubber composition comprising an uncrosslinked rubber component and radiation-crosslinked polyolefin particles.
2. The friction transmission belt of claim 1 , wherein
with the radiation-crosslinked polyolefin particles contain ultrahigh molecular weight polyolefin particles having an average molecular weight of 500,000 or more.
3. The friction transmission belt of claim 1 , wherein
the radiation-crosslinked polyolefin particles contain crosslinked polyethylene particles.
4. The friction transmission belt of claim 1 , wherein
a content of the radiation-crosslinked polyolefin particles in the uncrosslinked rubber composition is 20 parts by mass or more and 100 parts by mass or less with respect to 100 parts by mass of the uncrosslinked rubber component.
5. The friction transmission belt of claim 1 , wherein
the uncrosslinked rubber composition further contains uncrosslinked polyolefin particles.
6. The friction transmission belt of claim 1 , further comprising
a core rubber portion covered with the rubber layer.
7. The friction transmission belt of claim 6 , wherein
the core rubber portion is made of a rubber composition in which a content of the radiation-crosslinked polyolefin particles with respect to 100 parts by mass of a rubber component is smaller than the content of the radiation-crosslinked polyolefin particles with respect to 100 parts by mass of the uncrosslinked rubber component of the rubber layer, or a rubber composition not containing the radiation-crosslinked polyolefin particles.
8. The friction transmission belt of claim 1 , wherein the rubber layer is made of a porous rubber.
9. A method for forming the friction transmission belt according to claim 1 comprising heating and pressing an uncrosslinked rubber composition prepared by mixing an uncrosslinked rubber component and radiation-crosslinked polyolefin particles, and thereby crosslinking the uncrosslinked rubber composition.
10. The method of claim 9 , wherein
the radiation-crosslinked polyolefin particles are prepared by irradiating uncrosslinked polyolefin particles with radiation.
11. The method of claim 9 , wherein the radiation-crosslinked polyolefin particles are formed into clusters, further comprising fusing and integrating the clusters by the heating into a spherical or ellipsoidal shape.
12. A friction transmission belt comprising a rubber layer forming a pulley contacting portion, wherein
the rubber layer is made of a rubber composition containing a crosslinked rubber component and crosslinked polyolefin particles, and
the crosslinked polyolefin particles contain crosslinked polyolefin hollow particles having hollow portions.
13. A friction transmission belt comprising a rubber layer forming a pulley contacting portion, wherein
the rubber layer is made of a rubber composition containing a crosslinked rubber component and crosslinked polyolefin particles prepared by irradiating uncrosslinked polyolefin particles with radiation.