Low molecular weight polymers and their use as dispersion AIDS
Disclosed are low molecular weight polymers formed from monomers comprising ethylene, an alpha-olefin, and optionally a non-conjugated diene, and the use of such polymers to improve the dispersion of reinforcing agents into high molecular weight polymers.
1 . A polymer formed from monomers comprising ethylene; CH 2 ═CHQ wherein Q is C 1 -C 8 alkyl; and optionally a non-conjugated polyene; wherein
a) ethylene is present in an amount of from about 67% to about 75% by weight;
b) the non-conjugated polyene is present in an amount of from about 0% to about 30% by weight; and
c) CH 2 ═CHQ is present in an amount of from about 15% to about 40% by weight;
said polymer having a viscosity average molecular weight of from about 4,000 to about 30,000 and being a solid at room temperature.
2 . The polymer of claim 1 , wherein the non-conjugated polyene is selected from the group consisting of 5-ethylidene-2-norbornene, 1,4-hexadiene and dicyclopentadiene.
3 . The polymer of claim 2 , wherein Q is methyl.
4 . The polymer of claim 3 , wherein the polyene component is present in an amount of from about 1% to about 20% by weight.
5 . The polymer of claim 4 , wherein the polyene component is present in an amount of from about 3% to about 15% by weight.
6 . The polymer of claim 1 , wherein the CH 2 ═CHQ component is present in an amount of from about 20% to about 35% by weight.
7 . The polymer of claim 6 , wherein the CH 2 ═CHQ component is present in an amount of from about 22% to about 30% by weight.
8 . The polymer of claim 1 , wherein the polymer has a viscosity average molecular weight of from about 5,000 to about 10,000.
9 . The polymer of claim 1 , wherein the polymer yields about 10 mm or less in a needle penetration test.
10 . The polymer of claim 1 , wherein said polymer further comprises a reinforcing agent.
11 . The polymer of claim 10 , wherein the reinforcing agent is selected from the group consisting of aramid fibers, cotton, polyesters, fiberglass, and mixtures thereof.
12 . The polymer of claim 11 , wherein the reinforcing agent comprises aramid fibers.
13 . The polymer of claim 10 , wherein the reinforcing agent is present in an amount of up to about 70% by weight.
14 . A composition which comprises:
a) a polymer formed from monomers comprising ethylene; CH 2 ═CHQ wherein Q is C 1 -C 8 alkyl; and optionally a non-conjugated polyene; wherein
i) ethylene is present in an amount of from about 67% to about 75% by weight;
ii) the polyene is present in an amount of from about 0% to about 30% by weight; and
iii) CH 2 ═CHQ is present in an amount of from about 15% to about 40% by weight;
said polymer having a viscosity average molecular weight of from about 4,000 to about 30,000;
b) a reinforcing agent; and
c) a high molecular weight polymer.
15 . The composition of claim 14 , wherein the non-conjugated polyene is selected from the group consisting of 5-ethylidene-2-norbornene, 1,4-hexadiene and dicyclopentadiene.
16 . The composition of claim 15 , wherein Q is methyl.
17 . The composition of claim 16 , wherein the polyene component is present in an amount of from about 1% to about 20% by weight.
18 . The composition of claim 17 , wherein the polyene component is present in an amount of from about 3% to about 15% by weight.
19 . The composition of claim 14 , wherein the CH 2 ═CHQ component is present in an amount of from about 20% to about 35% by weight.
20 . The composition of claim 19 , wherein the CH 2 ═CHQ component is present in an amount of from about 22% to about 30% by weight.
21 . The composition of claim 14 , wherein the polymer of part a) has a viscosity average molecular weight of from about 5,000 to about 10,000.
22 . The composition of claim 14 , wherein the polymer of part a) yields about 10 mm or less in a needle penetration test.
23 . The composition of claim 14 , wherein the reinforcing agent is selected from the group consisting of aramid fibers, cotton, polyesters, fiberglass, and mixtures thereof.
24 . The composition of claim 23 , wherein the reinforcing agent comprises aramid fibers.
25 . The composition of claim 14 , wherein the high molecular weight polymer is selected from the group consisting of natural rubber and synthetic rubber.
26 . The composition of claim 25 , wherein the synthetic rubber is selected from the group consisting of ethylene/alphaolefin/nonconjugated polyene (EPDM) rubbers, styrene/butadiene rubbers, acrylonitrile/butadiene (NBR) rubbers, polychloroprene and sulfur modified polychloroprene, and polybutadiene rubbers.
27 . A moulded article made from the composition of claim 14 .
28 . The article of claim 27 , wherein the article is selected from the group consisting of a v-belt, a timing belt, a conveyor belt, a drive belt, a hose, a seal, a diaphragm, a cable and a roll cover.