US 2785989 A
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United States Patent METALLIC SOAPS OF FATTY ACIDS AND POLY- HYDROXY MONOCARBOXYLIC ACIDS Gerald M. Davis, Clark, and Maynard B. Winston, Woodbridge, N. 1., assignors to American Cyanamid Company, New York, N. Y., a corporation of Maine No Drawing. Application March 29, 1954, Serial No. 419,612
7 Claims. (Cl. 106-243) This invention relates to polyvalent metal soaps capable of forming fluid solutions in organic solvents when dissolved therein in amounts up to 30% and to coating, impregnation, sealing and waterproofing compositions containing them.
The coating and waterproofing properties of the polyvalent metal salts or soaps, better known in the art as metallic soaps, has been well recognized and their application to the above-mentioned and similar uses is now firmly established. The most convenient method of applying such polyvalent metal soaps to various surfaces such as wood, paper, cloth, leather, masonry, and the like, has been to make up a solution thereof in an organic solvent and to spray the same on the surface to be treated. Various volatile organic solvents have been used in the preparation of such polyvalent metal soap solutions, the more common ones including the aliphatic and aromatic hydrocarbons and their halogenated derivatives. While .the foregoing practice has found some success in the art, "many difliculties have been encountered, inasmuch as when more than about 2% or 3% of some soaps are dissolved in some organic solvents, the resulting mass either thickens to such an extent or actually forms a solidified gel, as to render it substantially useless as a sprayable coating or waterproofing composition. While the thickened mass or solidified gel can be heated to render it less viscous, the application thereof in a heated state is occasionally dangerous due to the volatile and inflammable nature of the solvents used and is usually unsatisfactory for most purposes. Furthermore, the application of solutions containing only from 2% to 3% of the polyvalent metal soap is also highly commercially impractical in view of the low concentration of the solids in the solution, which factor additionally increases the cost of the product due to large amounts of solvent necessary.
Various efforts have been made to solve the foregoing problems by increasing the soap concentration without undesirably decreasing the fluidity of the resulting solution. Peptizing agents having an acidic nature, such as acetic acid, phenol, tartaric acid, oxalic acid, and the like, have been used to increase the soap concentration in. a solvent without affecting the fluidity thereof. This proposal has proven to be undesirable commercially in view of the corrosive character imparted to the composition by such acidic agents. Another effort has involved the use of the ethanolamines, or the ethanolamine salts of the higher fatty acids, for the purpose of increasing the concentration of polyvalent metal soap solution. A solution produced according to this teaching also has not found too widespread success.
A principal object of the present invention is to overcome the foregoing defects and other disadvantages.
Another principal object of the present invention is to provide an improved, relatively highly concentrated polyvalent metal soap solution of low viscosity.
A further principal object of the present invention is and waterproofing composition.
A still further principal object of the invention is to provide fluid polyvalent metal soap solutions suitable as coating and waterproofing compositions containing up to 30% polyvalentmetal soap concentrations.
It has now been found that the foregoing and other objects of the present invention may be achieved by the use of a polyhydroxy monocarboxylic acid, such as gluconic acid, mannonic acid, and the like, in conjunction with the fatty acid, or equivalent acid, used in the formation of the polyvalent metal salt or soap. It has been found that the use of the polyhydroxy monocarboxylic acid remarkably reduces the viscosity of the resulting commercial compositions whereby readily sprayable solutions containing high percentages of the mixed metallic salts or soaps can be prepared.
Gluconic acid is a pentahydroxy monocarboxylic acid, having the formula C5Hs(OH)5COOH, and is more specifically known as 1,2,3,4,5-pentahydroxy caproic acid. It normally exists as a white, odorless powder having a melting point of C. and is soluble in water. It is found in stereoisomeric dextroand levoforms, as well as mixtures of the same. Mannonic acid is a stereoisomer, or epimer, of gluconic acid, also has the formula C5Hs(OH)5COOH butpossesses a slightly higher melting point than gluconic acid. It similarly exists in dextroand levoforms, as well as mixtures of the same. These acids are members of the sugar acidseries which can be converted from one form to another by various conversion reactions, such as epiinerization by heating in quinoline or pyridine. It is to be appreciated that in the following disclosure, Whenever the terms gluconic acid or mannonic acid appear, such is intended to include the various isomeric and epimeric forms individually or as mixtures. It is further to be noted that the metallic salts thereof are sometimes referred to as metallic soaps.
In the preparation of the composition of the invention, any suitable water-insoluble polyvalent metal soap of a higher fatty acid or similar acid maybe employed. Examples of such soaps include the polyvalent metal soaps of fatty acids containing from 8 to 22 or more carbon atoms, such as, for example, the aluminum, calcium, magnesium, zinc, etc., soaps of caprylic, capric, lauric, myristic, palmitic, stearic, arachidic, behenic, oleic, palmitoleic, lauroleic, myristoleic, linoleic, ricinoleic, and the like acids, as well as branched-chain acids having an equal number of carbon atoms. Mixtures of acids such as hydrogenated fish oil fatty acids, hydrogenated cottonseed oil fatty acids, hydrogenated soy bean fatty acids, hydrogenated tallow fatty acids, etc., are similarly usable. While any suitable polyvalent metal soap may be used in accordance with the invention, the aluminum soaps are preferred, and particularly aluminum stearate, palmitate or other saturated soaps of this metal.
The invention will be further described in greater detail by the following specific example. It should be understood, however, that although these examples may set forth in particular detail some of the more specific features of the invention, they are given primarily for purposes of illustration of preferred preparations and resulting evaluations and the invention in its broader aspects is not to be construed as limited thereto.
Example 1 A soap solution was prepared from 232 grams of Snodottee acids (essentially hydrogenated saturated fatty acids derived from marine origin comprising 6% C14; 28% C16; 26% C18; 25% C20; 2-3% unsaturated acids), 40 grams of 98% sodium hydroxide and 3000 grams of water. This solution was heated to a temperature of approximately 65 to 70 C. and a second solution comprising 600 grams of saturated alum solution and 50 grams 30f gluconic acid was added thereto. This addition repre- 3 sented 17.8% by weight of gluconic acid based on the total weight of the acids used. The precipitate which formed was very grainy. It was filtered, washed and dried overnight at a temperature of approximately 80 C. The material was very sticky while 'hot but, after cooling to room temperature, it became quite brittle.
A solution of 15% of this material was dissolved in commercial toluene and formed a.clear, thin solution. No change was noted in the viscosity characteristics of this solution when it was heated to approximately 75 C.
The 15% solution in toluol was sufliciently thin and fluid to permit spraying on various textile materials such as cotton, wool, asbestos, rockwool, and the like. A 2530% solution was formed in toluol and was used to coat and waterproof heavier materials such as wood shingles, cement, plaster, variousbuilding materials, and the like. This solution having a higher concentration formed a thick layer on drying and had excellent waterproofing characteristics. A 15% solution in Stoddard Solution was made up and found to be easily sprayable on a canvas tent .to make the article waterproof. The same concentrations of aluminum stearate in the same solvents were found to be very thick and viscous and could not be satisfactorily sprayed or used as a dipping or painting solution.
Example 2 A sodium soap solution of a fatty acid mixture was formed from 500 grams of Hydrofol 405 (having the approximate composition: 70.5% stearic acid; 28.0% palmitic acid; 1.5% myristic acid; 6% unsaturated acids), 100 grams of 98% sodium hydroxide and 1600 grams of water. This solution was heated to a temperature of approximately 65 to 70 Cvand to its was added a solution of 1500 grams of water, 250 grams of alum and 100 grams of 50% gluconic acid solution. (9.1% by weight of gluconic acids based on the total weight of the acids used.) The precipitate which formed was very grainy and formed a smooth filter cake which was washed on a laboratory crock and dried overnight at a temperature of approximately 70 C.
A 15 solution of toluol was thin, clear and quite fluid, both at room temperature and at 75 C. A 15% solution in Solvesso (petroleum solvents having a boiling point range of 95 C.290 C.) remained fluid over a similar range.
A laboratory analysis indicated the following values:
Ash "percents- 8.66 Washed ash do 7.41 Water soluble do 1.25 Acid value 24.36
Solutions of the aluminum soap in various organic solvents such as petroleum ether, naphtha, xylene, cyclohexane, trichlorobenzene, carbon tetrachloride, Stoddard Solvent, chloroform, alpha pinene, beta pinene, turpentine, etc., were foundto be clear and thin and were easily sprayable up to 15 to 20% concentration.
Example 3 A sodium soap solution of mixed fatty acids was formed from 500 grams of Hydrofol 405, 100 grams of 98% sodium hydroxide and 1600 grams of water. This solution was heated to a temperature of approximately 65 to 70 C. and to it was added a solution comprising 1500 grams of water, 250 grams of alum, and 50 grams of 50% gluconic acid solution. The gluconic acid represented 4.8% by weight of the total acids used.
The precipitate was grainy and sticky and was filtered, washed and dried overnight in an oven maintained. at a temperature of approximately 70 C. A 15% solution in toluene was thin and clear and sprayable both at room temperature and at 75 C.
A laboratory analysis indicated the following specifications:
Ash "percent" 9.58 Washed ash do 7.23 Water soluble do 2.35 Acid value 17.9
Example 4 A A sodium soap of mixed fatty acids was formed from 500 grams of Emersol 110 (a mixture of Chi-C18 acids having an iodine value of 9-15), 100 grams of 98% sodium hydroxide and 1600 grams of water. This solution was heated to a temperature of approximately 65 C. and to it was added 1500 grams of water, 250 grams of alum and 100 grams of 50% gluconic acid solution.
The remainder of the process set forth in Example 1 was followed substantially as set forth therein and the resulting product was found to be slightly more fluid than the product resulting from Example 1.
Example 5 A sodium soap of mixed fatty acids was formed from 50 grams of Hydrofol 405 (acids derived from hydrogenated oils of vegetable, animal and marine origin, normally comprising Chi-C18 acids), 10 grams of 98% sodium hydroxide and 1600 grams of water. This solut-ion was heated to a temperature of approximately 65 to C. and to it was added a solution containing 150 grams of water, 25 grams of alum and 10 grams of a 50% mannonic acid solution.
The temperature maintained during the precipitation was in the range of approximately 65 to 70 C. The precipitate was grainy, and was filtered, washed and dried overnight in an oven maintained at a temperature of approximately C.
A 15 solution of the dried material was soluble in toluene. Wood shingles were coated with this solution and found to be waterproof.
Example 6 The procedures set forth in Example 1 were followed substantially as set forth therein with the exception that Hystrene S97 containing 97% stearic acid was used in lieu of the mixed fatty acids. The resulting aluminum soap formed then and clear 152% toluene solutions which could be easily sprayed on various textile articles and building materials.
Example 7 The procedures set forth in Example 2 were followed substantially as set forth therein except that the gluconic acid and the mixed fatty acids were combined and reacted with the sodium hydroxide prior to the addition of the alum solution. Substantially the same polyvalent metal soap (aluminum) was obtained having substantially the same properties and characteristics.
The quantity of the polyhydroxy monocarboxylic acid used in proportion to the total acid used may be varied within wide limits. As little as 1% or less of gluconic acid by weight has affected the viscosity characteristics of the resulting soap composition. When a higher percentage of gluconic acid was used, the resulting soap composition became more fluid, due apparently to the greater number of'gluconate radicals attached to the metallic element and the lesser number of fatty acid radicals similarly attached. Compositions containing up to 100% gluconic acid and no other acid have been prepared but the higher cost of such compositions renders them commercially impracticable as coating, impregnating, sealing or waterproofing agents. In general, it may be stated that compositions containing from about 1% to about 25% by weight are economically and industrially most desirable.
As shown primarily in Example 2, the metallic soaps are soluble iira very wide range of solvents without becoming too thick or gelatinous .to use readily. It was observed that in many cases, aluminum steal-ate could not form the thin and clear concentrated solutions which were possible by the addition of the polyhydroxy monocarboxylic acid during the soap formation.
This viscosity-reducing ch racteristic created by the use of such an acid is also of value in increasing the fluidity, when desired, of other compounded compositions such as greases, waxes, soaps, paints, varnishes, rubber, plastics, cosmetics, adhesives, etc.
Although we have described several specific examples of our inventive concept, we consider the same not to be limited thereby nor to the specific substances mentioned therein but to include various other compounds of equivalent constitution as set forth in the claims appended hereto. It is understood that any suitable changes, modifications and variations may be made without departing from the spirit and scope of the invention.
What we claim is:
1. A waterproofing composition comprising a volatile organic hydrocarbon solvent containing a metal soap of from about 75% to about 99% by Weight of a fatty acid containing from 8 to 22 carbon atoms and from about 1% to about 25% by weight of a pentahydroxy monocarboxylic acid, said metal being selected from the group consisting of aluminum, zinc, calcium and magnesium.
2. A waterproofing composition comprising a volatile organic hydrocarbon solvent containing a metal soap of from about 75% to about 99% by weight of a fatty acid containing from 8 to 22 carbon atoms and from about 1% to about 99% by weight of gluconic acid, said metal being selected from the group consisting of aluminum, zinc, calcium and magnesium.
3. A waterproofing composition comprising a volatile organic hydrocarbon solvent containing an aluminum soap of from about to about 99% by weight of a fatty acid containing from 8 to 22 carbon atoms from about 1% to about 25 by weight of gluconic acid.
4. A waterproofing composition comprising a volatile organic hydrocarbon solvent containing an aluminum soap of from about 75% to about 99% by weight of stearic acid and from about 1% to about 25% by weight or" gluconic acid.
5. A metal soap of a mixture of from 99 to 75 parts by weight of a fatty acid containing from S to 22 carbon atoms and from 1 to 25 parts of a pentahydroxymonocarboxylic acid, said metal being selected from the group consisting of aluminum, zinc, calcium and magnesium.
6. A metal soap of a mixture of from 99 to 75 parts by Weight of a fatty acid containing from 8 to 22 carbon atoms and from i to 25 parts of gluconic acid, said metal being selected from the group consisting of aluminum, zinc, calcium and magnesium.
7. An aluminum soap of a mixture of from 99 to 75 part by weight of stearic acid and from 1 to 25 parts of gluconic acid.
References Qited in the file of this patent UNITED STATES PATENTS 1,900,693 Coolidge Mar. 7, 1933 2,081,407 Munich May 25, 1937 2,223,158 Licata et al Nov. 26, 1940 2,350,688 Licata et al. June 6, 1944 2,626,897 Young et al Jan. 27, 1953 2,628,195 Allison et al. Feb. 10, 1953