TIRE SEALANT

Abstract

An efficient tire sealant that is environmentally friendly or less damaging to the environment, which is characterized by a high stability, good processability, and safe application. The tire sealant includes approximately 5 wt. % to approximately 50 wt. % of a bio-based aliphatic diol; approximately 5 wt. % to approximately 70 wt. % natural rubber latex; and approximately 0.001 wt. % to approximately 10 wt. % of a water-soluble polymer as an additive for adjusting and/or influencing a freezing point of the tire sealant.

Claims

1. A tire sealant, comprising: approximately 5 wt. % to approximately 50 wt. % of a bio-based aliphatic alcohol; approximately 5 wt. % to approximately 70 wt. % rubber latex; approximately 0.001 wt. % to approximately 1 wt. % of a water-soluble polymer as an additive for adjusting and/or influencing a freezing point of the tire sealant.

2. The tire sealant according to claim 1, wherein the water-soluble polymer serving as an additive for adjusting and/or influencing the freezing point of the tire sealant is configured so as to suppress the freezing point of the tire sealant disproportionately to its concentration, unlike the bio-based aliphatic alcohol serving as the anti-freeze agent.

3. The tire sealant according to claim 1, wherein the water-soluble polymer serving as an additive for adjusting and/or influencing the freezing point of the tire sealant is selected from partially hydrolyzed polyvinyl alcohol, at least one polyvinyl alcohol oligomer and combinations thereof.

4. The tire sealant according to claim 1, wherein the water-soluble polymer serving as an additive for adjusting and/or influencing the freezing point of the tire sealant is selected from a polyethylene glycol (PEG), a derivative thereof, polyvinylpyrrolidone (PVP), polyacrylic acid (PAA), a polyacrylamide, a polyoxazoline, a polyphosphate, polyglycerin, hydroxyethyl starch, a polyamide, a hydrophilic polysaccharide, a sucrose epichlorohydrin copolymer, and combinations thereof.

5. The tire sealant according to claim 1, wherein the bio-based aliphatic alcohol is selected from 1,3-propanediol, ethylene glycol, propylene glycol, glycerol, and combinations thereof.

6. The tire sealant according to claim 1, wherein the tire sealant further comprises: approximately 2 wt. % to approximately 70 wt. % of synthetic rubber latex, wherein the synthetic rubber latex is selected from polybutadiene rubber, styrene butadiene rubber, acrylonitrile butadiene rubber, ethylene vinyl acetate rubber, chloroprene rubber, vinyl pyridine rubber, butyl rubber, and carboxylated versions thereof, and combinations thereof.

7. The tire sealant according to claim 1, wherein the tire sealant comprises a carboxylated styrene butadiene rubber dispersion.

8. The tire sealant according to claim 7, wherein the tire sealant has a dry rubber content between approximately 2.5 wt. % and approximately 10 wt. %.

9. The tire sealant of claim 1, wherein the tire sealant further comprises: approximately 2 wt. % to approximately 30 wt. % additional water.

10. The tire sealant according to claim 1, wherein the tire sealant further comprises: up to approximately 5 wt. % of at least one surfactant, wherein the at least one surfactant is selected from a non-ionic, anionic, cationic, amphoteric surfactant, polyoxyethylene alkyl ether, polyoxyethylene alkylamine, polyoxyethylene alkylamide, polyoxyethylene resin ester, fatty alcohol ethoxylate, and fatty alcohol polyglycol ether, and combinations thereof.

11. The tire sealant according to claim 1, wherein the tire sealant further comprises: up to approximately 15 wt. % of a tackifying agent, wherein the tackifying agent is selected from at least one of terpene resin, a phenolic resin, a terpene phenolic resin, a colophonium resin, a xylene resin, polyvinyl ester, polyvinyl alcohol, polyvinylpyrrolidone and combinations thereof.

12. The tire sealant according to claim 11, wherein the tackifying agent comprises a resin-based resin emulsion, having a dry content between approximately 40 wt. % and approximately 70 wt.

13. The tire sealant according to claim 1, wherein the tire sealant further comprises: approximately 0.1 wt. % to approximately 5 wt. % of a bulking agent and/or fibers, wherein the bulking agent is selected from the group consisting of calcium carbonate, barium carbonate, silicon dioxide, titanium dioxide, calcium sulfate, barium sulfate, aluminum oxide, and combinations thereof; and/or wherein the tire sealant further comprises at least one of the following: anti-aging agents, antioxidants, pigments, plasticizers, thixotropic agents, UV absorbents, flame retardants, dispersants, dehydrating agents, antistatics, and gelling agents.

14. The tire sealant according to claim 1, wherein the tire sealant comprises: approximately 15 wt. % to approximately 50 wt. % ethylene glycol and approximately 0.001 wt. % to approximately 1 wt. % of a partially hydrolyzed key-polyvinyl alcohol as an additive for adjusting and/or influencing the freezing point of the tire sealant; or approximately 15 wt. % to approximately 50 wt. % propylene glycol and approximately 0.001 wt. % to approximately 1 wt. % partially hydrolyzed K-polyvinyl alcohol as an additive for adjusting and/or influencing the freezing point of the tire sealant; or approximately 5 wt. % to approximately 25 wt. % 1,3-propanediol and approximately 0.001 wt. % to approximately 1 wt. % in particular partially hydrolyzed polyvinyl alcohol as an additive for adjusting and/or influencing the freezing point of the tire sealant; or approximately 15 wt. % to approximately 50 wt. % glycerol and approximately 0.001 wt. % to approximately 1 wt. % in particular partially hydrolyzed low-molecular-polyvinyl alcohol as an additive for adjusting and/or influencing the freezing point of the tire sealant.

15. The tire sealant according to claim 1, wherein the tire sealant comprises: approximately 25 wt. % to approximately 40 wt. %; of bio-based aliphatic alcohol, approximately 0.001 wt. % to approximately 0.2 wt. % polyvinyl alcohol; approximately 23 wt. % to approximately 30 wt. %; additional water; and approximately 25% to approximately 35% of a rubber.

16. The tire sealant according to claim 15 further comprising at least one additive.

17. A tire sealant, comprising: approximately 5 wt. % to approximately 50 wt. % of a bio-based aliphatic alcohol; approximately 5 wt. % to approximately 70 wt. % rubber latex; approximately 0.001 wt. % to approximately 0.1 wt. % of a water-soluble polymer as an additive for adjusting and/or influencing a freezing point of the tire sealant.

18. The tire sealant according to claim 17, wherein the water-soluble polymer serving as an additive for adjusting and/or influencing the freezing point of the tire sealant is selected from partially hydrolyzed polyvinyl alcohol, at least one polyvinyl alcohol oligomer, and combinations thereof.

19. The tire sealant according to claim 17, wherein the bio-based aliphatic alcohol is selected from 1,3-propanediol, ethylene glycol, propylene glycol, glycerol, and combinations thereof.

20. The tire sealant according to claim 17, wherein the tire sealant comprises: approximately 15 wt. % to approximately 50 wt. % ethylene glycol and approximately 0.001 wt. % to approximately 0.1 wt. % of a partially hydrolyzed polyvinyl alcohol as an additive for adjusting and/or influencing the freezing point of the tire sealant; or approximately 15 wt. % to approximately 50 wt. % propylene glycol and approximately 0.001 wt. % to approximately 0.1 wt. % partially hydrolyzed polyvinyl alcohol as an additive for adjusting and/or influencing the freezing point of the tire sealant; or approximately 5 wt. % to approximately 25 wt. % 1,3-propanediol and approximately 0.001 wt. % to approximately 0.1 wt. % in particular partially hydrolyzed polyvinyl alcohol as an additive for adjusting and/or influencing the freezing point of the tire sealant; or approximately 15 wt. % to approximately 50 wt. % glycerol and approximately 0.001 wt. % to approximately 0.1 wt. % in particular partially hydrolyzed alcohol as an additive for adjusting and/or influencing the freezing point of the tire sealant.

Description

DESCRIPTION OF PREFERRED EMBODIMENTS

[0028] According to embodiments of the tire sealant according to the invention, the anti-freeze additive comprises in particular partially hydrolyzed low-molecular-weight polyvinyl alcohol and/or at least one polyvinyl alcohol oligomer.

[0029] Of course, other anti-freeze polymers are possible, as well. In this regard, good results have also been achieved with polyethylene glycol (PEG) or a derivative thereof. The same applies in the transferred sense to polyvinyl pyrrolidone (PVP), polyacrylic acid (PAA), polyacrylamide, polyoxazoline, polyphosphate, polyglycerin in particular with low molecular weight, hydroxyethyl starch, polyamide, in particular poly-L-hydroxyproline and/or hydrophilic polysaccharide, in particular sucrose epichlorohydrin copolymer.

[0030] For the in particular and preferably bio-based aliphatic diol serving as the anti-freeze agent, 1,3-propanediol and/or combinations thereof and/or ethylene glycol and/or propylene glycol and/or glycerol is preferably considered.

[0031] The in particular and preferably bio-based aliphatic diol can be contained, in particular in an amount less than 50 wt. % and preferably less than 45 wt. % in the tire sealant. As explained above, suitable aliphatic diols comprise propane-1,3-diol and combinations thereof, in particular 1,3-propanediol, 2-methyl-2-propyl-1,3-propanediol, neopentyl glycol and combinations thereof, wherein 1,3-propanediol is in particular suitable. According to embodiments, the preferably bio-based aliphatic diol, such as propane-1,3-diol, is the only anti-freeze agent in the tire sealant.

[0032] The tire sealant can be free of or substantially free of methylene glycol, propylene glycol, glycerol, sorbitol, glycol ethers, potassium acetate, trimethylglycine, dimethyl sulfoxide, and other alternative anti-freeze agents. The term substantially free means that the anti-freeze agent contains at least approximately 95 parts by weight of the preferably bio-based aliphatic diol and no more than approximately 5 wt. % of another anti-freeze component. According to alternative embodiments, such alternative anti-freeze agents can be used in combination with the preferably bio-based aliphatic diol.

[0033] The rubber latex, in particular natural rubber latex, can be contained at approximately 5 wt. % to approximately 70 wt. % in the tire sealant. The rubber latex, in particular natural rubber latex, can be substantially free of coagulation agents and preferably has an average particle size of approximately 400 ?m or less. This can be achieved by producing a highly-filtered rubber latex, in that the rubber latex is filtered through a mesh screen. The mesh screen can have openings of approximately 300 to 500 ?m, preferably approximately 400 ?m. In particular, the natural rubber latex can also be biodegradable.

[0034] According to embodiments of the tire sealant according to the invention, the tire sealant comprises between approximately 2 wt. % and approximately 70 wt. % synthetic rubber latex. The synthetic rubber latex preferably comprises polybutadiene rubber, styrene butadiene rubber, acrylonitrile butadiene rubber, ethylene vinyl acetate rubber, chloroprene rubber, vinyl pyridine rubber, butyl rubber, and/or carboxylated versions thereof. As with natural rubber latex, the synthetic rubber latex can contain an amount of water required in order to form the latex.

[0035] Preferably, the tire sealant comprises a carboxylated styrene butadiene rubber dispersion, in particular with dry rubber between approximately 20 wt. % and approximately 70 wt. %, and more preferably between approximately 40 wt. % and approximately 50 wt. %. In particular, the tire sealant can have a dry rubber content between approximately 2.5 wt. % and approximately 10 wt. %.

[0036] The tire sealant preferably also comprises additional water. In particular, the tire sealant has between approximately 2 wt. % and approximately 30 wt. %, and preferably between approximately 2 wt. % and approximately 25 wt. % additional water. In this context, additional water means water that is not already a component of the rubber latex, in particular the rubber latex dispersion.

[0037] Additionally, the tire sealant can comprise up to approximately 5% of at least a surfactant. This can be, in particular, a non-ionic, anionic, cationic, and/or amphoteric surfactant. Preferably, polyoxyethylene alkyl ether, polyoxyethylene alkylamine, polyoxyethylene alkylamide, polyoxyethylene resin ester, fatty alcohol ethoxylate, and/or fatty alcohol polyglycol ether is considered as the surfactant.

[0038] Alternatively, or additionally, the tire sealant can also comprise between approximately 0.1 wt. % and approximately 5 wt. % of a bulking agent and/or fibers. The bulking agent is preferably selected from the group consisting of calcium carbonate, barium carbonate, silicon dioxide, titanium dioxide, calcium sulfate, barium sulfate, aluminum oxide, and combinations thereof.

[0039] Alternatively, or additionally, the tire sealant can contain anti-aging agents, antioxidants, pigments, plasticizers, thixotropic agents, UV absorbents, flame retardants, dispersants, dehydrating agents, antistatics, and/or gelling agents.

[0040] According to a preferred implementation of the tire sealant, the tire sealant comprises between approximately 15 wt. % and approximately 50 wt. % ethylene glycol, or preferably between approximately 15 wt. % and approximately 25 wt. % 1,2 or 1,3 propanediol, and between approximately 0.001 wt. % and approximately 10 wt. % in particular partially hydrolyzed low-molecular-weight polyvinyl alcohol as an anti-freeze additive.

[0041] According to an alternative composition, the tire sealant comprises between approximately 15 wt. % and approximately 50 wt. % propylene glycol and between approximately 0.001 wt. % and approximately 10 wt. % of an in particular partially hydrolyzed low-molecular-weight polyvinyl alcohol as an anti-freeze additive. Instead of approximately 15 wt. % to approximately 50 wt. % propylene glycol, the tire sealant can comprise approximately 5 wt. % to approximately 25 wt. % of a 1,3-propanediol and approximately 5 wt. % to approximately 20 wt. 20% glycerine.

[0042] In a further alternative embodiment, the tire sealant comprises between approximately 5 wt. % to approximately 25 wt. % 1,3-propanediol and preferably between approximately 2 wt. % and approximately 35 wt. % 1,3-propanediol, and between approximately 0.001 wt. % and approximately 10 wt. % of an in particular partially hydrolyzed low-molecular-weight polyvinyl alcohol as an anti-freeze additive.

[0043] In yet another implementation of the tire sealant, it comprises between approximately 15 wt. % and approximately 50 wt. % glycerol and between approximately 0.001 wt. % and approximately 10 wt. % of an in particular partially hydrolyzed low-molecular-weight polyvinyl alcohol as an anti-freeze additive.

[0044] Studies have shown that, in all of the aforementioned design variants, despite the reduced anti-freeze in comparison to conventional tire sealants, reduced viscosity can be achieved even at up to ?45? C.

[0045] In a particularly preferred design variant of the tire sealant, the tire sealant comprises approximately 25 wt. % to approximately 40 wt. %, and preferably approximately 30 wt. % to approximately 34 wt. %, and even more preferably approximately 31 wt. % to approximately 33 wt. % of an in particular bio-based aliphatic diol, in particular ethylene glycol, propylene glycol, glycerine, and/or 1,3-propanediol.

[0046] As an anti-freeze additive in this tire sealant composition, approximately 0.001 wt. % to approximately 0.2 wt. %, in particular approximately 0.05 wt. % to approximately 0.1 wt. %, and preferably approximately 0.07 wt. % to approximately 0.08 wt. % polyvinyl alcohol is used.

[0047] Additionally, the tire sealant composition comprises approximately 23 wt. % to approximately 30 wt. %, and preferably from approximately 25 wt. % to approximately 29 wt. % additional water, and approximately 25 wt. % to approximately 35 wt. %, and preferably approximately 25 wt. % to approximately 32 wt. % of a rubber, in particular a rubber dispersion.

[0048] With the tire sealant compositions mentioned above, a freezing point of below ?30? C. and even below ?40? can be achieved (depending on the proportion of the anti-freeze additive).