Propylene glycol based latex material
A rubber composition containing propylene glycol is presented. The rubber composition contains a surfactant, propylene glycol, and any of natural rubber, synthetic rubber, or a mixture of natural and synthetic rubber. The rubber composition is freeze protected for temperature as low as −35° C. and may be used as a tire sealant, among other uses. The surfactant has an HLB level greater than 13. A method of making the rubber composition is also presented. The method entails adding propylene glycol to a surfactant to form a propylene glycol mixture, and combining the propylene glycol mixture with a rubber emulsion. Optionally, a fibrous or non-fibrous filler (e.g., cellulose fiber) may be added to the propylene glycol mixture prior to being combined with rubber. Also optionally, a tackifier and an antioxidant may be added to the rubber emulsion prior to being combined with the propylene glycol mixture.
1 . A rubber composition comprising:
a latex rubber;
a surfactant having a hydrophilic-lipophilic balance level greater than 13; and
propylene glycol.
2 . The composition of claim 1 , wherein propylene glycol constitutes about 10% to 60% of the composition by weight.
3 . The composition of claim 1 , wherein the weight ratio of propylene glycol to the surfactant is between about 1:1000 to 1:10, inclusive.
4 . The composition of claim 1 , wherein the latex rubber comprises at least one of a natural rubber and a synthetic rubber and wherein the ratio of natural rubber to synthetic rubber is between about 1:100 and 100:1.
5 . The composition of claim 1 , wherein the latex rubber comprises at least one of a natural rubber and a synthetic rubber and the synthetic rubber includes one or more of styrene butadiene, acrylo nitrile butadiene, ethylenevinylacetate, chloroprene, vinylpyridene, and butyl rubber.
6 . The composition of claim 1 , wherein the fraction of latex rubber is between about 20% and 60% by weight.
7 . The composition of claim 1 further comprising a tackifier.
8 . The composition of claim 7 , wherein the latex rubber includes a natural rubber, and a weight ratio of the tackifier to the natural rubber is less than 1:5.
9 . The composition of claim 7 , wherein the latex rubber includes a natural rubber, and a weight ratio of the tackifier to the natural rubber is between about 1:20 and about 1:5.
10 . The composition of claim 7 , wherein the latex rubber includes a natural rubber and a synthetic rubber, and a weight ratio of a combination of the natural rubber and the tackifier to the latex rubber is less than about 1:5.
11 . The composition of claim 7 , wherein the ratio is between about 1:5 and about 1:7.
12 . The composition of claim 7 , wherein the tackifier is a hydrocarbon resin.
13 . The composition of claim 1 further comprising a fibrous filler material.
14 . The composition of claim 13 , wherein a weight fraction of the fibrous filler material is less than 10% of the weight of the rubber composition.
15 . The composition of claim 14 , wherein a single one of the fibrous filler material has a length between about 20 and 140 microns.
16 . The composition of claim 15 , wherein the single one of the fibrous filler material has a diameter less than 200 microns.
17 . The composition of claim 13 , wherein a single one of the fibrous filler material has a length between about 30 and 60 microns.
18 . The composition of claim 17 , wherein the single one of the fibrous filler material has a diameter less than about 250 microns.
19 . The composition of claim 18 , wherein a weight of the fibrous filler material is less than 10% of a weight of the rubber composition.
20 . The composition of claim 1 , wherein the surfactant is ethylene oxy.
21 . The composition of claim 1 further comprising a non-fibrous filler material.
22 . The composition of claim 1 further comprising at least one of rust and corrosion inhibitor, a biocide, and a phenolic-type antioxidant.
23 . A method of forming a rubber composition, the method comprising:
adding propylene glycol to a surfactant having an HLB level above 13 to form a propylene glycol mixture; and
combining the propylene glycol mixture with a rubber emulsion.
24 . The method of claim 23 , wherein the propylene glycol is added to achieve a surfactant to propylene glycol ratio that is between about 1:1000 and 1:10 by weight.
25 . The method of claim 23 , wherein the propylene glycol is added to achieve a surfactant to propylene glycol ratio between about 2:100 and 4:100 by weight.
26 . The method of claim 23 , wherein the mixture is combined with the rubber emulsion to achieve a propylene glycol fraction of 10% to 50% by weight.
27 . The method of claim 23 , wherein the mixture is combined with the rubber emulsion to achieve a solid rubber weight fraction of between about 20% to about 60%.
28 . The method of claim 23 further comprising adding a fibrous filler material to the mixture before combining the propylene glycol mixture with the rubber emulsion.
29 . The method of claim 23 further comprising adding an adhesive tackifier to the mixture.
30 . The method of claim 23 further comprising adding an adhesive tackifier to the rubber emulsion before combining with the propylene glycol.
31 . The method claim 23 , wherein the rubber emulsion comprises natural rubber and synthetic rubber.
32 . The method of claim 23 further comprising adding a fibrous filler material to the propylene glycol mixture.
33 . The method of claim 23 further comprising adding about 2 grams to about 200 grams of a cellulose fiber to about 1000 mL of the propylene glycol mixture.