Composition for increasing the friction of surfaces on ice
United States Patent [191 Craven Apr. 15, 1975 [75] Inventor: James M. Craven, Wilmington, Del.  
 [73] Assignee: E. I. du Pont de Nemours and Company, Wilmington, Del.  
 [22] Filed: Dec. 27, 1973 [21] Appl. No.: 428,722  
 [56] References Cited UNITED STATES PATENTS 2,739,135 3/1956 Delang 260/998.13 3,350,342 10/1967 Begley 260/336 3,475,205 10/1969 Byers ..ll7/l39 Enriquez 252/428 Wright 260/876 B Primary Examiner-Allan Lieberman [57] ABSTRACT The composition of this invention is utilized to increase the friction of surfaces on ice such as the tread surfaces on automobile and truck tires; the composition contains 525% by weight of a soluble elastomer such as a styrene-butadiene-styrene block copolymer; 43-92.99% by weight of a solvent for the elastomer; 2-20% by weight of dispersed, hard, inorganic particles, such as diatomaceous earth, having a particle size of 0.2 to 105 microns; and optionally, 0.0l-2% by weight of an antisettling agent for the particles; an aerosol composition is another aspect of this invention which contains 25-95% by volume of the above composition and 755% by volume of ,a propellant.  
 4 Claims, N0 Drawings COMPOSITION FOR INCREASING THE FRICTION OF SURFACES ON ICE BACKGROUND OF THE INVENTION stuck. Compositions previously used for this purpose either did not adhere to the tire, wore off the tire after only a short distance of travel, did not provide the necessary level of friction, or clogged the nozzle or valve of the dispensing vessel. v  
  The novel composition of this invention contains a binder and fine particles and has excellent adherence to rubber substrates such as tire treads, provides a high level of&#39;friction on icy roads, and is easily dispensed from a vessel without clogging the nozzle or .valve of the dispensing vessel.  
  SUMMARY OF THE INVENTION he composition of this invention consists essentially -257( by weight of a soluble elastomer;  
 43-92.997( by weight of a solvent for the elastomer having a high evaporation rate;  
 2-207( by weight of dispersed. hard, inorganic particles having a particle size of 0.2 to 105 microns; and optionally 0.01-27! by weight of an antisettling agent for said particles; 7  
 : another aspect of this invention comprises an aerosol composition of 25 to 95% by volume of the novel composition and 75 to 5% by volume of a propellant.  
 DESCRIPTION OF THE INVENTION The novel composition of thisinvention contains an elastomer which may be dissolved or dispersed in a liquid. Preferably, the elastomer is dissolved in the liquid. The composition contains about 5-25)? by weight of the elastomer, but preferably about 7-l572 by weight of the elastomer is used. 7  
  The following elastomers can be used in the novel composition: styrene-butadiene-styrene block copolymer rubber; chlorosulfonated polyethylene, polyester or polyether polyurethanes, polyureas, poly(methylacrylate). Preferably, the elastomers have a Shore Hardness of 30A to 80D and more preferably about 50-70A. The styrene-butadiene-styrene block copolymer rubbers are preferred and form a high-quality composition with excellent adhesion to conventional automobile and trucktires.  
  The novel composition contains about 43-92997: by weight of a solvent for the elastomer. If the elastomer is dispersed, a blend of a solvent and a nonsolvent can .be used. Preferably, a solvent for the elastomer is used.  
  ane, hexane, toluene, methyl ethyl ketone, methylene chloride, acetone, tetrahydrofuran, naphtha, diethyl ether, methyl isobutyl ketone, carbon tetrachloride, xylene, benzene,.chloroform, carbon disulfide, l,l,2,2- tetrachloroethane. Preferably, about 69.5-88.5% by weight of an organic solvent is used, and the preferred organic solvents are cyclohexane, hexane, toluene, and methyl ethyl ketone, and mixtures thereof.  
  To provide the necessary level of friction, the novel composition contains about 2-207: by weight of hard, inorganic particles such as diatomaceous earth, silicon carbide, aluminum oxide, silica, calcium carbonate, clay, magnesium silicate, calcium sulfate, potassium aluminum silicate, mica, barium sulfate, calcium silicate, aluminum silicate or crushed glass. Preferred are particles of diatomaceous earth, silicon carbide and aluminum oxide. To be effective in providing a high level of friction, the particles have a size of about 0.2 to 105 microns and preferably 5 to 62 microns and,  
 &#39; more preferably, 10 to 44 microns. In one preferred embodiment of this invention, the novel composition contains 4-1571 by weight of diatomaceous earth particles.  
  To keep the aforementioned particles in the novel composition from hard settling and to retard flocculation of the particles, preferably about 0.01-27r of an antisettling agent is used. Typical antisettling agents are aluminum stearate, hydrous magnesium aluminum silicate, alkylol amine salts of unsaturated fatty acids, calcium stearate, zinc stearate, fumed silica, zinc palmitate, dispersions ofBentone&#34; clay, aluminum octoate and other metallic soaps. About 05-1 5% by weight of aluminum stearate forms a high-quality composition wherein the particles do not hard settle but can be easily redisposed in the&#39;container with moderate agitation.  
  One particularly high-quality composition contains about 7-157: by weight of a styrene-butadiene-styrene block copolymer rubber;  
 69.5-88.57r by weight of an organic solvent for the rubber such as cyclohexane, hexane, toluene, methyl ethyl ketone, or mixtures of these solvents;  
 4-15% by weight. of diatomaceous earth particles having a particle size of 10 to 44 microns; 0.5-l.57( by weight of aluminum stearate.  
  The novel composition of this invention can be used as an aerosol. This is accomplished by charging about 1 25 to 95 percent by volume of the novel composition thane or mixtures of one or more of these propellants with trichloromonofluoromethane, or dichlorotetrafluoroethane. Hydrocarbon gases such as butane, propane, isobutane or mixtures thereof can be used. Compressed gases such as carbon dioxide, nitrous oxide, nitrogen or mixtures of two or more of these propellants can be used with the above hydrocarbon or halogenated hydrocarbon propellants. One preferred propellant comprises a mixture of trichloromonofluoromethane and carbon dioxide.  
  The novel composition can be applied by brushing, dipping, spraying and the like; but the preferred method is to apply the composition as an aerosol spray. The composition is applied to a dry thickness of about 0.5-5 mils; but, preferably, about 1-2 mils are applied.  
 The novel composition can be applied to a variety of substrates such as to hydrocarbon rubber compounds as are conventionally used for automobile and truck tire treads. The novel composition can be applied to the shoe and boot soles of a variety of materials such as polyvinyl chloride, leather. natural and synthetic hydrocarbon rubbers and the like. to skis to slow the rate of descent for beginners, to crutch tips and the like.  
  Obviously, the foremost use of the novel composition is as a tire-traction-promoting compound. and the composition is applied to the tread of automobile or truck tires to provide a high-friction surface. This surface is about 1-2 mils in thickness and remains on the tire at least 5-10 miles. depending on road conditions.  
  The following examples illustrate the invention. All parts and percentages are by weight unless otherwise indicated.  
 EXAMPLE 1 The following ingredients are blended together to form a composition:  
 Parts by Weight Kraton&#34; l 102- (Styrene-hutadicne-styrene block copolymer rubber having a tensile strength of 400 psi*. an ultimate elongation of 880%. a viscosity of 400 centipoises measured at polymer solids in toluene at 23C) 9.3] (yclohe xane 43.61 Hexane 36.90 &#34;Celite White Mist&#34; particles (diatomaceous earth having a particle size of less than 300 mesh [50 microns]) 9.27 Aluminum stearate anti-settling agent 0.90  
 psi-pounds per square inch The copolymer rubber and solvents are charged into a mixing vessel and stirred until the rubber is dissolved. The particles and the anti-settling agent are added and the composition is stirred until the particles are uniformly dispersed. The resulting composition has a solids content of about 19.5% by weight. The composition is stable and does not hard settle The particles can be redispersed with slight agitation even after long periods of standing on a shelf.  
  The above composition is sprayed onto the tread surface of the two rear tires of a Vega sedan weighing 2480 lbs. to provide a uniformly thick film on each of the tires. The sedan is in an ice skating rink and is fastened with nylon towing straps to a post. A dynamometer is fastened to one strap attached to the post and the second strap is attached to the sedan. The pulling force in pounds of the sedan is measured on ice at 0C and on ice at 8C. The pulling force is measured for the same sedan with untreated tires under the same ice temperature conditions. The same sedan is then equipped with two studded snow tires, and the pulling force is measured under the above conditions.  
  The results of the above tests are recorded in the following table:  
 DYNAMOMETER TESTS WITH VEGA SEDAN ON ICE SKATING RINK Pull (pounds) From 2480 Pound Vega on lce lce Temperature 0C 8C Pull Pull Maxi- Wheels Maxi- Wheels mum mum Pull Spinning Pull Spinning Untreated tires 3] 25 266 7l Treated tires 190 100 347 87 Studded snow tires 234 82 327 l07 The test results show a significant improvement in the amount of pull in pounds of the treated tires in I comparison to the untreated tires. Under some conditions the treated tires even have a greater pull than studded snow tires.  
 EXAMPLE 2 EXAMPLE 3 The following compositions are prepared: Composition A B C Kraton&#34; 1 I02 rubber (described in Example 1) Cyclohexanc l Hexane l Celite White Mist particles (described in Example I) Bentone dispersion (disperion of hydrous magnesium aluminum silicate mineral) 0.  
 Texaphor antisettling agent Anti-Terra A (alkylol amine salt of an unsaturated fatty acid) TOTAL 2.60 l2. l0 l0.30  
  As in Example l, the constituents for the composition are charged into a mixing vessel and thoroughly blended together to uniformly disperse the particles. Each of the above compositions is stable for long periods of time and can easily be redispersed, and each of the compositions provides traction to automobile tires as illustrated in Example 1.  
 The invention claimed is;  
 l. A composition consisting essentially of 5-257c by weight of a soluble elastomer having a- Shore A Hardness of 30A to D and consisting essentially of a styrene-butadiene-styrene block c0- polymer rubber;  
 7-l571 by weight of a styrene-butadiene-styrene block copolymer rubber;  
 69.588.5% by weight of an organic solvent for said rubber;  
 4-157: by weight of diatomaceous earth particles having a particle size of 5 to 62 microns and 0.5-1.5% by weight of aluminum stearate.  
 4. The composition of claim 3 in which the organic 0 solvent is selected from the group consisting of cyclohexane, hexane, toluene, methyl ethyl ketone, and mixtures of these solvents.