US3505226A - Stabilization of organic substrates - Google Patents

Description

United States Patent U.S. Cl. 252--49.6 20 Claims ABSTRACT OF THE DISCLOSURE Stabilization of organic substrates by incorporating therein a stabilizing concentration of a boron ester of a hydroxyalkyl-heterocyclic compound. One example is the stabilization of plastics and another example is the stabilization of hydrocarbon distillates.

CROSS REFERENCE TO RELATED APPLICATIONS This is a continuation-in-part of application Ser. No. 370,079, filed May 25, 1964, now U.S. Patent No. 3,446,- 808, issued May 27, 1969.

DESCRIPTION OF THE INVENTION This invention relates to the stabilization of organic substrates by incorporating therein a novel additive comprising a boron ester of a hydroxyalkyl-heterocyclic compound.

In a preferred embodiment the additive is a boron ester of an N-hydroxyalkyl-heterocyclic saturated compound. A particularly preferred additive is a boron ester of an N-hydroxyalkyl-piperazine and preferably of N- hydroxyalkyl-N-alkyl-piperazine. In a preferred embodiment the N'-alkyl substituent is of secondary alkyl configuration. Accordingly, particularly preferred additives of the present invention include borate of N-hydroxyethyl-N-isopropyl-piperazine, borate of N-hydroxyethyl- N'-secbutyl-piperazine, borate of N-hydroXy-ethyl N'- sec-pentylpiperazine, borate of N-hydroXyethyl-N-sechexyl'piperazine, borate of N-hydroXyethyl-N'-sec-heptyl piperazine, borate of bLhydroxyethyl-N'-sec-octy1-piperazine, borate of N-hydroxyethyl-N-sec-nonyl-piperazine, borate of N-hydroxyethyl-N'-sec-decyl'piperazine, borate of N-hydroxyethyl-N'-sec-undecyl-piperazine, borate of N-hydroxyethyl-N-sec-dodecyl-piperazine, borate of N- hydroxyethyl-N'-sec-tridecyl-piperazine, borate of N-hydroXyethyl-N-sec-tetradecyl-piperazine, borate of N-hydroxyethyl N sec-pentadecyl piperazine, borate of N- hydroXyethylN-sec-hexadecyl-piperazine, borate of N- hydroxylethyl N sec-heptadecyl-piperazine, borate of N-hydroxyethyl-N'-set octadecyl-piperazine, borate of N- hydroxyethyl N-sec-nonadecyl-piperazine, N-hydroxyethyl-N'-sec-eicosyl-piperazine, etc. In still another embodiment the additive is a boron ester of N-hydroxyethyl- N-cycloalkyl-piperazine, the cycloalkyl preferably being cyclohexyl, although it may be cyclobutyl, cyclopentyl, cycloheptyl, cyclooctyl, cyclononyl, cyclodecyl, cycloundecyl, cyclododecyl, etc. In still another embodiment the piperazine may be substituted on the ring by alkyl, cycloalkyl or aryl groups. It is understood that the hydroxyethyl group may be replaced by hydroxypropyl, hydroxybutyl, hydroxypentyl, hydroxyhexyl, hydroxyheptyl, hydroxyoctyl, etc.

The particular compounds set forth above are derivatives of piperazine in which the nitrogen atoms are in a position para to each other. Another embodiment comprises the boron esters of corresponding compounds prepared from hexahydropyrimidine, in which the nitrogen atoms are in a position meta to each other, and from hexahydropyridazine, in which the nitrogen atoms are n a position ortho to each other. Illustrative compounds in this embodiment include borate of N-hydroxyalkyl- N'-sec-alkyl-hexahydropyrimidine, in which the hydroxyalkyl moiety contains from 1 to 8 or more carbon atoms and in which the sec-alkyl group contains from 3 to 20 or more carbon atoms, borate of N-hydroxyalkyl-N'- cycloalkyl-hexahydropyrimidine, in which the cycloalkyl preferably is cyclohexyl, although it may contain from 4 to 12 or more carbon atoms in the cycloalkyl group and the hydroxyalkyl moiety contains from 1 to 8 carbon atoms, borate of N-hydroxyalkyl-N-sec-alkyl-hexahydropyridazine, in which the hydroxyalkyl moiety contains from 1 to 8 or more carbon atoms and in which the sec-alkyl group contains from 3 to 20 or more carbon atoms, borate of N-hydroxyalkyl-N'-cycloalkyl-hexahydropyridazine, in which the cycloalkyl preferably is cyclohexyl, although it may contain from 4 to 12 or more carbon atoms in the cycloalkyl group and the hydroxyalkyl moiety contains from 1 to 8 carbon atoms. Here again, the ring may be substituted by alkyl, cycloalkyl or aryl groups.

In another embodiment the additive of the present invention is a boron ester of N-hydroxyalkyl-piperidine and preferably of N-hydroxyalkyl-piperidine containing hydrocarbon substituents attached to the ring. Illustrative compounds in this embodiment include borate of p-secalkyl-N-hydroXyalkyl-piperidine in which the sec-alkyl group contains from 3 to 20 or more carbon atoms and in which the hydroxyalkyl moiety contains from 2 to 8 or more carbon atoms. In another embodiment the alkyl substituent may be in the orthoor meta-position. In still another embodiment, two alkyl substituents are attached to the piperidine ring and these may be in the 2,3-, 2,4-, 2,5-, 2,6-, 3,4-, or 3,5-positi0ns. The alkyl groups preferably are sec-alkyl of from 3 to 20 or more carbon atoms each although, in another embodiment, one of the alkyl groups may be a primary alkyl group of from 1 to 20 carbon atoms and the other is a secalkyl group of from 3 to 20 carbon atoms.

In still another embodiment the additive of the present invention is a boron ester of an N-hydroxyalkyl-heterocyclic saturated five membered ring. Borates of N-hydroxyalkylN sec-alkyl-imidazolidine and N-hydroxyalkyl-N-cycloalkyl-imidazolidine are the preferred compounds. In the imidazolidine ring the nitrogens are in 1,3- positions in the five membered ring. Other compounds include boron ester of N-hydroxyalkyl'pyrrolidine, boron ester of N-hydroxyalkylpyrazolidine, boron ester of N- hydroxyalkyl-hydrogenated 1,2,3-triazole, boron ester of N-hydroXyalkyl-hydrogenated 1,2,4-triazole, etc., and preferably these compounds containing a substituent, preferably sec-alkyl or cycloalkyl, attached to the ring and/ or to one or more of the nitrogen atoms in the compounds containing more than one nitrogen atom. In still another embodiment the additive comprises a boron ester of N- hydroxy-hydrogenated indole, boron ester of N-hydroxyalkyl-hydrogenated carbazole, boron ester of N-hydroxyalkyl-hydrogenated quinoline, boron ester of N-hydroxyalkyl-hydrogenated acridine, boron ester of N-hydroxyalkylhydrogenated phenazine, etc. Here again, it is understood that the hydroxyalkyl moiety may contain from 2 to 8 or more carbon atoms and that alkyl, cycloalkyl or aryl substituents may be attached to the ring or to one of the nitrogen atoms for compounds containing more than one nitrogen atom.

The preferred N-hydroXyalkyl-heterocyclic saturated compounds for use in the present invention are prepared in any suitable manner. In some cases, the N-hydroxyalkyl-heterocyclic saturated compound may be purchased in the open market and then is reacted with suitable borylating agent as will be hereinafter described. When the N-hydroxyalkyl-heterocyclic compound is not available commercially, it may be prepared in any suitable manner. For example, piperazine may first be subjected to oxyalkylenation and, when a substituent is to be attached to the other nitrogen atom, this is effective by reductive alkylation. In another method, piperazine may first be subjected to reductive alkylation and then is subjected to oxyalkylenation. The oxyalkylenation is effected in any suitable manner and may be accomplished by charging the piperazine or N-alkyl-piperazine into a reaction zone and passing alkylene oxide, particularly ethylene oxide, into the reaction zone. The alkylene oxide is used in a proportion of one mole thereof per each nitrogen atom to be oxyalkylenated. In the case of piperazine, equal mole proportions of alkylene oxide and piperazine are employed. When desired, an excess of one of the reactants may be present in order to insure complete reaction. The oxyalkylenation reaction readily occurs at a low temperature which may range from room temperature to 150 C. in the absence of a catalyst. As hereinbefore set forth, ethylene oxide is preferred. Other alkylene oxides include propylene oxide, butylene oxide, pentylene oxide, hexylene oxide, etc., as well as styrene oxide, epichlorohydrin, etc. When oxyalkylenation is conducted first, the reaction products are fractionated or otherwise treated to separate the mono-oxyalkylenated product from the reaction mixture.

As hereinbefore set forth, in a preferred embodiment the piperazine or N-hydroxyalkyl-piperazine is subjected to reductive alkylation. In one embodiment the reductive alkylation is effected using a ketone in order to prepare the corresponding N-hydroxyalkyl-N-sec-alkyl-piperazine. Any suitable ketone may be used and will be selected to produce the desired substituent. Illustrative preferred ketones include acetone, methyl ethyl ketone, methyl propyl ketone, methyl butyl ketone, methyl pentyl ketone, methyl hexyl ketone, methyl heptyl ketone, methyl octyl ketone, methyl nonyl ketone, methyl decyl ketone, etc., diethyl ketone, ethyl propyl ketone, ethyl butyl ketone, ethyl pentyl ketone, ethyl hexyl ketone, ethyl heptyl ketone, ethyl octyl ketone, ethyl nonyl ketone, etc., dipropyl ketone, propyl butyl ketone, propyl pentyl ketone, propyl hexyl ketone, propyl heptyl ketone, propyl octyl ketone, etc., dibutyl ketone, butyl pentyl ketone, butyl hexyl ketone, butyl heptyl ketone, butyl octyl ketone, etc., dipentyl ketone, pentyl hexyl ketone, pentyl heptyl ketone, pentyl octyl ketone, etc., dihexyl ketone, hexyl heptyl ketone, hexyl octyl ketone, etc., diheptyl ketone, heptyl octyl ketone, dioctyl ketone, etc. It is understood that the ketone may be of straight or branched chain configuration. Cycloalkyl ketones include particularly cyclohexanone. Ketones are available commercially or may be synthesized as required. A number of ketones and particularly the higher boiling ketones are available as mixtures which are either products or by-products of commercial operations. These mixtures generally are available at comparatively low cost and, as another advantage of the present invention, the mixtures may be used without the added time and expense of separating specific compounds in pure state. One such mixture available commercially is Stearone which is diheptadecyl ketone.

The reductive alkylation of the ketone and piperazine or hydroxyalkyl-piperazine is effected in any suitable manner. The reaction is effected using at least one mole of ketone per mole of nitrogen atom to be reductively alkylated. In the case of piperazine, this means equal mole proportions of ketone and piperazine. When reacting hydroxyalkyl-ated-piperazine an excess of ketone, which may range up to about 20 mole proportions of ketone per 1 mole proportion of heterocyclic nitrogen compound, generally is employed to insure complete reaction. In one embodiment the reaction is effected in the presence of hydrogen and a suitable reductive alkylation catalyst in one step, which may be either continuous or batch type operation. Ar v suitable reductive alkylation catalyst is em loyed including those containing nickel, platinum, palladium, etc., preferably composited 'with a suitable support. A particularly preferred catalyst comprises a composite of platinu'm and alumina, which may or may not contain combined halogen. The platinum generally is present in the catalyst in a concentration of from about 0.1 to about 2% by weight of the final catalyst and the halogen, when present, is in a concentration of total halogen of from about 0.01% to about 1% by weight of the final catalyst, the' halogen preferably comprising fluorine and/or chlorine. Another suitable catalyst comprises an intimate mixture of copper oxide, chromium oxide and barium oxide. When using the platinum catalyst, the temperature generally will be within the range of from about to about 260 C. and a hydrogen pressure of from about to about 3000 pounds per square inch or more.

In a continuous type operation, the catalyst is disposed as a fixed bed in a reaction zone and the N-hydroxyalkyl-piperazine, ketone and hydrogen, at the required temperature and pressure, are passed through the catalyst in either upward or downward flow. The reactor efiluent is separted into a hydrogen stream and unreacted products, all or part of which may be recycled to the reaction zone, and the alkylated N-hydroxyalkyl-piperazine is separated from the other products. In a batch type operation, the N-hydroxy-alky-l-piperazine, ketone and catalyst are disposed in a reaction zone which is pressured with hydrogen and then heated to the desired temperature. After cooling, the products are separated to recover the alkylated N-hydroxy-alkyl-piperazine. While the one-step process generally is preferred, it is understood that the reaction may be effected in two steps. In the first step, effected in the absence of hydrogen, the Schiff base is first prepared and then is dehydrogenated in a separate step to form the alkylated N-hydroxyalkyl-piperazine.

In another embodiment of the invention the N-hydroxy-alkyl heterocyclic compound contains unsaturation in the heterocyclic ring. Illustrative 6-member heterocyclic compounds in this embodiment include pyridine, dihydropyridine, tetr ahydropyridine, pyrimidine, dihydropyrimidine, tetrahydropyrimidine, pyrazine, dihydropyrazine, tetr-ahydropyrazine, pyridazine, dihydropyrid-azine, tetrahydropyridazine, 1,2,3-triazine and the dihydro derivative, indole and the di or tetrahydro derivatives, quinoline and the dihydro or tetrahydro derivatives, carbazole and the dihydro, tetrahydro, hexahydro or octahydro derivatives, acridine and the dihydro, tetrahydro, hexahydro or octahydro derivatives, phenazine and the dihydro, tetrahydro, hexahydro or octahydro derivatives thereof, etc. Here again it is understood that at least one of the nitrogen atoms is substituted with a hydroxyalkyl group which will be selected from those hereinbefore set forth. Also, it is understood that, in compounds containing more than one nitrogen atom, the other nitrogen atom may be substituted with a hydrocarbyl group as hereinbefore set forth. Also the carbon atoms of the heterocyclic compound may be substituted with a hydrocarbyl group and particularly alkyl groups of from one to 30 carbon atoms. Five member heterocyclic compounds containing unsaturation in the heterocyclic ring include imidazole, imidazoline, pyrazole, pyrazoline, thiazole, thiazoline, oxazole, oxazoline, isoxazole, isoxazoline, 1,2,3-triazole, 1,2,3-triazoline, 1,2,4-triazole, 1,2,4-triazoline, pyrrol, pyrroline, etc. Here again at least one of the nitrogen atoms contains a hydroxyalkyl attachment and, where more than one nitrogen is present, the other nitrogen atom or atoms may be substituted with a hydrocarbyl group as hereinbefore described. Also, one or more of the carbon atoms of the heterocyclic ring may be substituted with a hydrocarbyl group selected from those hereinbefore set forth.

In still another embodiment of the invention,'the hydroxyalkyl group is attached to a carbon atom of the heterocyclic ring and one or more, when present, of the nitrogen atoms may be substituted with a hydrocarbyl group from those hereinbefore set forth. The heterocyclic moiety also will be selected from those described herein 5 before. Illustrative examples include 1-hydrocarby1-2- hydroxyalkyl-hexahydro pyrimidine and a specific compound in this embodiment is included in the examples appended to present specifications.

As hereinbefore set forth the N-hydroxyalkyl-heterocyclic saturated compounds are preferred for use in preparing the boron ester. However, the N-hydroxyalkylheterocyclic compounds containing unsaturat-ion in the heterocyclic ring also may be used for preparing the boron ester, with the understanding that the boron ester thereof will not necessarily be equivalent as an additive in the same or different substrate. Also, it is understood that the saturated and unsaturated heterocyclic compounds having the hydroxyalkyl attached to a nucleus carbon atom may be used in preparing the boron ester and here again the resultant additive will not necessarily be equivalent for use in the same or different substrate.

The hydroxyalkyl-heterocyclic compound now is reacted With a borylating agent. Any suitable borylating agent may be used. A particularly preferred borylating agent is boric acid or boric oxide. Other borylating agents include trialkyl borates in which the alkyl groups preferably contain from 1 to 4 carbon atoms each. In the use of the latter type borylating agent, the reaction is effected by transesterification and, accordingly, there is no advantage to using trialkyl borates containing more than 4 carbon atoms in each alkyl group, although the higher boiling trialkyl borates may be used when satisfactory and advantages appear therefor. Still other borylating agents include alkyl boric acid, dialkyl boric acid, boric oxide, boric acid complex, cycloalkyl boric acid, aryl boric acid, dicycloalkyl boric acid, diaryl boric acid, or substitution products of these with alkoxy, alkyl and/ or halo groups, etc. In another embodiment the borylating agent is a boronate of the formula RB(OH) and, in still another embodiment, it is a borinate of the formula R --B-OH, where R is hydrogen, alkyl, aryl or cycloalkyl. When R is alkyl, it preferably contains from one to 20 carbon atoms. When R is aryl, it preferably is phenyl, although it may be naphthyl, anthracyl, etc. When R is cycloalkyl, it preferably is cyclohexyl, although it may be cyclopropyl, cyclobutyl, cyclopentyl, cycloheptyl, cyclooctyl, cyclononyl, cyclodecyl, cycloundecyl, cyclododecyl, etc. Also it is understood that the aryl or cycloalkyl nucleus may be substituted with one or more of alkoxy, alkyl or halo groups.

The reaction of the borylating agent and the hydroxyalkyl-heterocyclic compound is effected in any suitable manner. The ortho-borates are formed by heating and stirring the reactants at a temperature up to about 100 C. and thus within the range of from about 60 to about 100 C. when using boric acid. The meta borates are formed at temperatures above about 100 C. and thus may be within the range of from about 100 to about 200 C. or more. The higher temperature of from about 100 to about 200 C. is used when employing trialkyl borates in order to effect the transesterification reaction. In one method the reactants are refluxed in the presence of a solvent. Any suitable solvent may be used and advantageously comprises an aromatic hydrocarbon solvent including benzene, toluene, xylene, ethylbenzene, cumene, etc. Other solvents include n-hexane, n-heptane, n-octane, chlorinated hydrocarbons, etc., or mixtures thereof. The use of a solvent is particularly preferred when boric acid is used as the borylating agent. When using a trialkyl borate as the borylating agent, the solvent may be omitted. While no catalyst normally is required, a catalyst may be used when employing the trialkyl borate. Any suitable catalyst may be employed including sodium hydrogen sulfate, potassium hydrogen sulfate, tin oxide, polyalkyl tin derivatives, alkoxy tin derivatives, polyalkyl titanium derivatives, alkoxy titanium derivatives, trialkyl or trialkoxy aluminum, etc. The borylating agent and hydroxyalkyl-heterocyclic compound generally are used in a mole proportion within the range of from about 0.3 to

6 1 mole proportions of borylating agent per one mole proportion of hydroxyalkyl-heterocyclic compound.

In another embodiment, an alcohol, including aliphatic or aromatic alcohol, or mercaptan, including aliphatic or aromatic mercaptan, is included in the reaction charge to satisfy one or two of the valences of the boron. When used, the alcohol or mercaptan is employed in an amount of from about 1 to 2 mole proportions thereof per 1 mole proportion of the N-hydroxyalkyl-heterocyclic compound. Preferred aliphatic alcohols include methanol, isopropanol, butanol, sec-butyl alcohol, pentanol, hexanol, heptanol, octanol, nonanol, decanol, undecanol, dodecanol, tridecanol, tetradecanol, pentadecanol, hexadecanol, heptadecanol, octadecanol, nonadecanol, eicosanol, etc. Preferred aromatic alcohols include phenol, cresol, xylenol, etc. The alcohol or aromatic phenol moiety may be substituted with alkoxy groups or thioalkoxy groups. Preferred mercaptans include butyl mercaptan, pentyl mercaptan, hexyl mercaptan, heptyl mercaptan, octyl mercaptan, nonyl mercaptan, decyl mercaptan, undecyl mercaptan, dodecyl mercaptan, etc., and thiophenol, thiocresol, thioxyleno-l, etc.

As hereinbefore set forth, the reaction is readily effected by refluxing the borylating agent and hydroxyalkyl-heterocyclic compound, with or without solvent and/or catalyst as required. Refluxing is continued until the required amount of water when using boric acid or alcohol when using trialkyl borate is collected. Following completion of the reaction, the solvent and alcohol, if any, are removed by vacuum distillation. The borylated hydroxyalkyl-heterocyclic compound generally is recovered as a liquid and used as such or, when desired, the product may be retained in the solvent and used as such or the product may be prepared as a solution in a different solvent and used in this manner.

The exact structure of the borylated product will vary with the proportions of reactants employed, with the particular borylating agent, with the conditions under which the borylating is effected and whether an extraneous alcohol or mercaptan is used. For example, when reacting 3 mole proportions of N-hydroxyethyl-N'-alkylpiperazine with 1 mole proportion of boric acid, it is believed that the triester is formed in which all valences of the boron are satisfied by the piperazyl ethoxy radical formed by the liberation of water. When equal mole proportions of the N-hydroxyethyl-N-alkyl-piperazine and boric acid are reacted at a higher temperature, the metaborate is formed. When the reaction is effected using an extraneous alcohol or mercaptan in addition to the N-hydroxyethyl-N-alkyl-piperazine, the resulting borate will be a mixed borate in which one or two valences of the boron are satisfied by the hydroxyalkyl-piperazine and the remaining valence or valences of the boron are satisfied by the alcohol or mercaptan. When employing a trialkyl borate as the borylating agent, either complete or partial transesterification occurs, depending upon the proportions of reactants and conditions of operation.

Regardless of the specific reactants and the concentrations thereof, the additives of the present invention all will contain a carbon-oxygen-boron linkage. In other words, at least one valence of the boron will react with the 'hydroxyl group of the hydroxyalkyl moiety. This is an essential feature of the additives of the present invention.

From the above discussion, it will be seen that the exact structure of the boron ester may vary and also that the product may consist of a mixture of compounds. Accordingly, the additives of the present invention are being claimed generically. It is understood that the different borylated compounds meeting the requirements as hereinbefore set forth may be used for the purposes of the present invention but that the different additives are not necessarily equivalent in their effectiveness in the same or different substrate.

The additives of the present invention possess varied utility. They are of especial utility in substrates exposed to weather and in this embodiment the compounds of the present invention serve as weathering stabilizers. Although the mechanism in which these compounds function is not completely understood, these compounds serve to protect substrates which undergo ultraviolet light induced oxidation. In addition, the compounds of the present invention possess anti-static properties and adhesion improving properties. The compounds are also effective as antioxidants, peroxide dccomposers and bactericides, especially for petroleum products. Also, they may serve as dye sites in plastics. Furthermore, they are of ready solubility in most substrates. The substrates normally subject to exposure to weather include plastics, resins, paints, varnishes, other coatings, fibers, textiles, etc.

Illustrative plastics which are stabilized by the additives of the present invention include polyolefins and particularly polyethylene, polypropylene, polybutylene, mixed ethylene propylene polymers, mixed ethylene butylene polymers, mixed propylene butylene polymers, etc. The solid olefin polymers are used in many applications including electrical insulation, light weight outdoor furniture, awnings, cover for greenhouses, fibers, etc. In many of these applications the solid olefin polymer is exposed to sunlight and air.

Another plastic being used commercially on a large scale is polystyrene and is stabilized in the present invention. The polystyrene type resins are particularly useful in the manufacture of molded or machined articles which find application in such goods as windows, optical goods, automobile panels, molded household articles, etc. One disadvantage of polystyrene is its tendency to deteriorate when exposed to direct sunlight and air for extended periods of time. Other plasticsgwhich are stabilized in accordance with the present invention include ABS (acrylonitrile-butadiene-styrene), ANS (copolymer of acrylonitrile and styrene), polyphenyl ether (polyphenyl oxide), and their reaction products with styrene, etc.

Other plastics being commercially on a large scale are in the textile class and include nylon (polyamide), Perlon L or 6-nylon (poylamide), Dacron (terephthalic acid and ethylene glycol), Orlon (polyacrylonitrile), Acrilan (polyacrylonitrile modified with vinyl acetate), rayon, etc. Here again, deterioration occurs due to ultraviolet light and oxidation and is inhibited in the present invention. In addition, the additives of the present invention may serve as dye sites in plastics. This is especially desirable in plastics used for textiles as, for example, use of plastics for carpeting, fabrics, etc. Furthermore, the additives of the present invention inhibit discoloration and, therefore, the color of the product will remain true, Which also is of considerable advantage in the case of clear products.

Still other plastics which are stabilized in the present invention, are prepared from other monomers and are available commercially. Illustrative examples include polyurethanes, both the urethane foams and the rigid resins, epoxy resins, polycarbonates, etc. Still other illustrative examples include phenol-formaldehyde resins, urea-formaldehyde resins, melamine-formaldehyde resins, acryloid plastics which are derived from methyl, ethyl and higher alkyl acrylates and methacrylates as monomers used in the polymerization or their co and ter polymers. Other polymers include polyacetals, especially polyformaldehydes such as Delrin and Celcon. Still other substrates include vinyl, acrylic, nitrocellulose based coatings; especially cellulose acetate, cellulose acetate butyrate, ethyl cellulose, etc. Still other substrates are polyesters, including linear or cross-linked, reinforced polyesters, laminate polyesters, etc., various latexes, lacquers, alkylds, varnishes, polishes, stains, pigments, dyes, textile finishing formulations, etc.

It is understood that the plastic may be fabricated into any desired finished product including moldings,

castings, fibers, films, sheets, rods, tubing or other shapes.

Rubber is composed of polymers of conjugated 1,3- diense, either as polymers therof or copolymers thereof with other polymerizable compounds, and the rubbers, both natural and synthetic, are included as solid polymers in the present specification and claims. These rubbers are stabilized in accordance with the present invention. Synthetic rubbers include SBR rubber (copolymer of butadiene and styrene), Buna N (copolymer of butadiene and acrylonitrile), butyl rubber (copolymer of butadiene and isobutylene), neoprene rubber (chloroprene polymer), Thiokol rubber (polysulfide), silicone rubber, etc. The natural rubbers include hevea rubber, caoutchouc, balata, gutta percha, etc. It is well known that rubber undergoes deterioration due to oxygen and, when exposed to direct sunlight for extended periods of time, also undergoes deterioration from this source.

The above are illustrative examples of various plastics and resins which are improved by the additives of the present invention. As hereinabove set forth, still other substrates include paints, varnishes, drying oils, pigments, rust preventative coatings, wax coatings, protective coatings, etc. It is understood that the compounds of the present invention may be used in any coating which is subject to exposure to ultraviolet light, oxidation, heat, etc. While the compounds are especially useful in materials subject to such exposure, it is understood that the compounds of the present invention also may be used advantageously in other coatings, plastics, resins, paints, etc., which normally are not exposed outdoors.

The compounds of the present invention also are of utility as additives in other organic substrates including, for example, hydrocarbon distillates. Illustrative hydrocarbon distillates include gasoline, naphtha, kerosene, jet fuel, solvents, fuel oil, burner oil, range oil, diesel oil, marine oil, turbine oil, cutting oil, rolling oil, soluble oil, drawing oil, slushing oil, lubricating oil, fingerprint remover, wax, fat, grease, etc. In the oils, the compounds of the present invention serve to inhibit oxidative deterioration, thermal deterioration, etc., thereby retarding and/ or preventing sediment formation, dispersion of sediment when formed, preventing and/or retarding discoloration, rust or corrosion inhibitor, detergent, etc. In gasoline, the additive improves the combustion characteristics of the gasoline.

In many applications it is advantageous to utilize the compounds of the present invention in conjunction with other additives. For example, particularly improved results are obtained in the stabilization of plastics, apparently due to a synergistic effect, when the compound of the present invention is used in admixture with a phenolic antioxidant including particularly 2,6-ditertiarybutyl-4-methylphenol. Other inhibitors which may be used generally will be of the phenolic or amine type and include phenyl-alpha-naphthylamine, phenyl-beta-naphthylamine, phenothiazine, Nonox WSP, Nonox C1, dialkylated phenols, trialkylated phenols including 2,4-dimethyl-6-tertiarybutylphenol, etc., Santonox R, Santowhite, alkyl-alkoxyphenols, 2246 (2,2-'methylene-bis-(4- methyl-G-tert-butylphenol and (2,2 methylene bis-(4- ethyl-6 tert butylphenol, diphenyl-p-phenylenediamine, 1,1,3-tris (2 methyl-4-hydroxy-5-t-butylphenyl)butane, 703 (2,6-di-tert-butyl alpha dimethylamino-p-cresol), 4,4'bis-(2-methyl-6-tert-butylphenol); 4,4 thio-bis-(6- tert-butyl-o-cresol); 4,4 bis (2,6-di-tert-butylphenol); 4,4-methylene-bis-(2,6-di-tert-butylpheno1); Salol (sali cylic acid esters), p-octyl-phenylsalicylate, various phosgene alkylated phenol reaction products, various alkoxyalkyldihydroxybenzophenones, polyalkyldihydroxybenzophenones, tetrahydroxybenzophenones, 2,4,5-trihydroxybutyrophenone, etc., and especially such hydroxybenzophenones as 2,2'-dihydroxy-4-octoxybenzophenone, 2,2- dihydroxy-4-decoxy-benzophenone, 2,2 dihydroxy-4-dodecoxybenzophenone, 2,2'-dihydroxy-4-octadecoxybenzophenone, etc., in general any alkoxy or cycloalkoxy substituted 2,2 dihydroxybenzophenone, 2 hydroxy 4'- octoxybenzophenone, 2-hydroxy-4'-decoxybenzophenone, 2-hydroxy-4-dodecoxy, etc., and in general any alkoxy or cycloalkoxy substituted 2 hydroxybenzophenone. Other ultraviolet light stabilizers include nickel-bisdithiocarbamates and especially nickel bis-dibutyldithiocarbamate, nickel bis-dihydroxypolyalkylphenol sulfides, especially [2,2-thiobis-(4 t octylphenolato)]-nbutylamine nickel (II), dilauryl beta-mereaptodipropionate, dihydroxytetralkyl sulfides, dihydroxytetralkyl methanes, various trithiophosphites as trilaurylthiophosphite, dialkylphosphites, trialkylphosphites, high molecular weight nitriles, various Mannich bases, various N-hydroxyphenylbenzotriazoles such as 2-(2'-hydroxy-5-octylphenyl)- benzotriazole, 2-(2' hydroxy-5-dodecylphenyl)-benzotriazole, 2-(2' hydroxy-5'-octoxyphenyl)-benzotriazole, 2- 2'-hydroxy-5-dodecoxyphenyl) -benzotriazole, Tinuvin 326, etc, in general, any alkyl or alkoxyphenyl substituted benzotriazole, etc. The additional inhibitor may be used in a concentration of from about 1% to about 75% by weight of the compound of the present invention. Generally, the additional inhibitor will be used in a concentration within the range of from about 0.001% to about 3% and more particularly from about 0.001% to about 3% and more particularly from about 0.01% to about 2% by weight of the substrate. When used in gasoline, kerosene, diesel fuel, or fuel oil, the additional additive may comprise the metal deactivator as, for example, disalicylal diaminopropane, ethylene diamine tetraacetic acid, etc., dyes, detergents, surface active agents, antiknock agents, cetane improvers, etc. As specifically required, such additional additives are used in conventional concentrations.

The additive of the present invention will be used in a stabilizing concentration which will depend upon the particular substrate. The additive may be used in a concentration as low as 0.0001% to about 5% but generally will be used in a concentration of from about 0.01% to about 2% by weight of the substrate. When used in hydrocarbon distillate and particularly gasoline, kerosene, diesel fuel, or fuel oil, the additive generally is used in a concentration of from about 0.000l% to about 0.5%. The additive is incorporated in the substrate in any suitable manner. For example, when it is incorporated into a plastic, resin or the like, it may be added to the hot melt with stirring, generally in a Banbury mixer, extruder or other device. When it is added to a liquid, it is incorporated into the liquid with intimate stirring. When it is added to a multicomponent mixture as, for example, grease, it may be added to one of the components and, in this manner, incorporated into the final mix or it may be added directly into the final mix.

In another embodiment the additive of the present invention serves as a biocide and, in this embodiment, will be used in very low concentrations which may range from to 200 parts per million of the substrate.

The additive of the present invention may be utilized as such or prepared as a solution in a suitable solvent including alcohols and particularly methanol, ethanol, propanol, butanol, etc., hydrocarbons and particularly benzene, toluene, xylene, eumene, decalin, etc.

The following examples are introduced to illustrate further the novelty and utility of the present invention but not with the intention of unduly limiting the same.

EXAMPLE I The additive of this example was prepared by the reaction of 3 mole proportions of N-hydroxyethyl-N-sec-octyl-piperazine with 1 mole proportion of boric acid. The N-hydroXyethyl-N-sec-octyl-piperazine was prepared as follows. Hydroxyethyl-piperazine, which is available in the open market, was subjected to reductive alkylation by reacting 240 g. of hydroxyethyl-piperazine and 500 g. of methyl hexyl ketone at 160 C. in the presence of hydrogen and an alumina-platinum catalyst containing about 0.3% by weight of platinum. The resultant N-hydroxyethyl-N'-sec-octyl-piperazine was analyzed and found to have a basic nitrogen of 8.27 meq./g. and a basic mole combining weight of 121 which corresponds to the theoretical basic mole combining weight of 121. The product had an index of refraction n of 1.4787.

Borylation of the N-hydroxyethyl-N'-sec-octyl-piperazine, prepared in the above manner, was effected by refluxing 72.6 g. (0.3 mole) thereof and 6.18 g. (0.1 mole) of boric acid in the presence of 100 g. of benzene at C. Heating and refluxing was continued until a total of about 5 cc. of Water was collected. Following completion of the reaction, the benzene was removed by distil lation at 160 C. under water pump vacuum, and the borated product was recovered as a liquid which contained 1.24% by weight of boron which corresponds to a theoretical boron content of 1.47% by weight for the triester. It is believed that the triester is of the following structure:

In the above structure the hydrogens attached to the carbon atoms have been omitted in the interest of simplicity.

EXAMPLE II The additive of this example is prepared by reacting N- hyclroxyethyl-Nsec-octyl-piperazine with tri-n-butyl b0- rate. This is a transesterification reaction and is effected by heating and refluxing 3 mole proportions of N-hydroxyethyl-N-sec-octyl-piperazine and 1 mole proportion of trin-butyl borate at a temperature of about 160 C. The refluxing is continued until the required amount of butanol is collected, the butanol resulting from the transesterification reaction. Following completion of the reaction, the borated product is recovered as a liquid.

EXAMPLE III The additive of this example is prepared by reacting boric acid with N-hydroxypropyl-N-cyclohexyl-hexahydropyrimidine. Hexahydropyrimidine is oxypropylenated by reacting equal mole proportions of propylene oxide with hexahydropyrimidine, and the resulting N-hydroxypropylyrimidine is subjected to reductive alkylation with cyclohexanone in the presence of an alumina-platinum catalyst. One mole proportion of the resultant N-hydroxypropyl-N'-cyclohexyl-hexahydropyrimidine is subjected to heating and refluxing with 0.33 mole proportions of boric acid in the presence of benzene solvent. Following completion of the reaction, the product is recovered as a solution in benzene.

EXAMPLE IV The additive of this example is the meta-borate formed by the reaction of p-octyl-N-hydroxyethyl-piperidine and boric acid. The reaction is effected by heating and refluxin-g equal mole proportions of poctyl-N-hydroxyethylpiperidine and boric acid in the presence of g. of xylene. The temperature of reaction is above C. and the refluxing is continued until the desired amount of water is collected.

EXAMPLE V The additive of this example is prepared by the reaction of N-hydroxyethyl-N-decyl-hexahydropyridazine. Specifically, 2 mole proportions of N-hydroxyethyl-N'- decyl-hexahydropyridazine and 1 mole proportion of boric acid are heated and refluxed in the presence of benzene solvent. The refluxing is continued until the desired amount of Water is collected. The borated product is recovered as a solution in benzene.

EXAMPLE v1 The additive of this example is prepared by heating and refluxing a mixture of 1 mole proportion of boric acid, 2 mole proportions of N-hydroxyethyl-N'-hexyl-piperazine and 1 mole proportion of isooctyl alcohol in the presence of benzene solvent. The reaction is continued until the desired amount of water is collected, after which the borated product is subjected to vacuum distillation to remove the benzene solvent.

EXAMPLE VII The additive of this example is prepared by heating and refluxing 2 mole proportions of N-hydroxyethyl-N'-dodecyl-piperazine, 1 mole proportion of butyl mercaptan and 1 mole proportion of boric acid in the presence of benzene solvent. The heating and refluxing is continued until the reaction is completed, after which the reaction mixture is subjected to vacuum distillation to remove the benzene solvent.

EXAMPLE VIII EXAMPLE IX The borate of this example is prepared by subjecting l-hydroxyethyl-Z-rnethyl glyoxalidine to reductive alkylation with methyl hexyl ketone in the presence of hydrogen and alumina-platinum catalyst. The resultant product is reacted in a proportion of 3 moles thereof with 1 mole of boric acid by heating and refluxing in the presence of benzene solvent. Following completion of the reaction, the borated product is recovered as a solution in benzene.

EXAMPLE X As hereinbefore set forth, the additive of the present invention is useful as a weathering agent in plastics. The plastic of this example is solid polypropylene. The solid polypropylene without inhibitor is stated to have properties substantially as follows:

TABLE I Specific gravity 0.9100.92O Refractive index, n 1.510 Heat distortion temperature:

at 66 p.s.i. load C 116 at 264 p.s.i. load C 66 Tensile yield strength, p.s.i.

(ASTM D638-58T) (0.2" per min.) 4700 Total elongation, percent 300400 Stiffness flexural (ASTM D747-50) 1O p.s.i 1.8 Shore hardness (ASTM D676-55T) 74D The polypropylene was milled in a two-roll heated mill of conventional commercial design and the additive, when employed, was incorporated in the sample during the milling. The samples were pressed into sheets of about 17 mil. thickness and cut into plaques of about 1%" X 1%.". The plaques were inserted into plastic holders, afiixed onto a rotating drum and exposed to carbon arc rays at about 52 C. in a Weather-Ometer. The samples were examined periodically by infrared analysis to determine the carbonyl band at 1715 cm.- which is reported as the carbonyl number. The higher intensity of the carbonyl band indicates a higher carbonyl concentration (expressed as carbonyl number) and accordingly increased deterioration.

A sample of the pblypropylene without inhibitor developed a carbonyl number of greater than 1000* within hours of exposure in the Weather-Ometer. Another sample of the same polypropylene containing 0.15% by weight of 2,5-ditertiarylbutyl-4-rnethylphenol developed a carbonyl number over 1000 within 360 hours of exposure in the Weather-Ometer.

Another sample of the solid polypropylene containing 1% by weight of the borated compound of Example I and 0.15% by weight of 2,6-ditertiarybutyl-4-methylphenol was evaluated in the Weather-Ometer in the same manner. After 1100 hours of exposure in the Weather- Ometer, the carbonyl number of this sample was 240. As another important advantage of the additive of the present invention, the sample of polypropylene containing this additive, even after exposure in the Weather-Ometer for this long period of time, still remained clear and did not undergo discoloration.

EXAMPLE XI The solid polypropylene plastic of Example I also was evaluated for physical properties after exposure in the Weather-Ometer. Dumb-bell specimens (1" wide, 4%" long and 0.020" thick with the neck being 1" long and A" wide) were exposed in the Weather-Ometer in the same manner described in Example X and then the physical properties were evaluated in an Instrom Universal tester. In general, the Instrom Universal tester is a machine in which the dumb-bell specimen is gripped firmly at the top and bottom. A constant pull of two inches per minute is exerted downwardly and the following data are obtained: 1) the percent elongation until rupture occurs, (2) the tensile strength which is the pounds per square inch of force at which rupture occurs, (3) the pull strength which is the pounds per square inch of elongation between the yield point and the tensile strength and (4) the elastic modulus which also is reported in pounds per square inch. The data in the following table report the results of such evaluations for (1) a sample of the polypropylene without additive and (2) a sample of the polypropylene containing 1% by Weight of the additive of Example I and 0.15% by weight of 2,6-ditertiarybutyl-4-methylphenol. In each case, these data were obtained prior to exposure in the Weather-Ometer and after 480 hours. The sample containing the additive also was evaluated after 720 hours of exposure in the Weather- Ometer.

TABLE II Elastic modulus, Elongation, percent Tensile strength, p.s.i. Pull strength, p.s.i. p.s.1, 10 Additive 0 480 720 0 480 720 0 V 480 720 0 480 720 None 555 4,785 2,400 Composition oiExampleX 503 426 380 4,110 3,390 3,315 2,500 2,620 2,725 5 14 5.27 4 82 From the data in the above table, it will be seen that the control sample (not containing an additive) lost all of its desirable physical properties after exposure in the Weather-Ometer for 480 hours. In contrast, the sample containing the additive composition of Example X still re tained a considerable portion of these desired physical properties even after exposure in the Weather-Ometer for 720 hours.

EXAMPLE XII The plastic of this example is solid polyethylene of the high density type. An inhibited product of this polyethylene is marketed commercially under the trade name of Fortiflex. A batch of this polyethylene free of inhibitor is obtained and is cut into plaques in the same manner described in Example X and evaluated in the Weather- Ometer. A sample of this polyethylene without inhibitor, when evaluated in the Weather-Ometer, increases from a carbonyl number of 28 to a carbonyl number of 855 within 624 hours. In contrast, another sample of the polyethylene containing 1% by Weight of the borated compound of Example II does not develop a carbonyl number of above 800 for a considerably longer period of time.

EXAMPLE XIII The additive of Example III is incorporated in a concentration of 1% by weight in polystyrene and serves to inhibit deterioration of the polystyrene upon exposure to weathering.

- EXAMPLE XIV The compound of Example I is used in a concentration of 0.3% by weight as an additive in gasoline and serves to improve the combustion characteristics of the gasoline, as well as serving as an anti-static agent therein.

EXAMPLE XV The additive of this example is the borate of l-hydroxyethyl-Z-heptadecyl-imidazoline and was prepared by refluxing 51 g. (0.134 mole) and 2.76 g. (0.0446 mole) of boric acid in the presence of about 100 g. of benzene. The refluxing was continued for about 6 hours and a total of 1.7 cc. of water was collected. The reaction mixture was filtered and the solvent subsequently removed by distillation at a temperature of 150 C. under water pump vacuum. The product was analyzed and found to have a boron content of 0.93% which corresponds to the theoretical boron content of 0.93%. The product had a basic nitrogen of 2.49 meq./ g.

It is believed that the triester is formed in which each of the three hydroxyl groups of the boric acid reacts with a hydroxyl group of three moleculesof the imidazoline.

EXAMPLE XVI The additive of this example is one in which the hydroxyalkyl is attached to a carbon atom of the heterocyclic compound. The heterocyclic compound used in this preparation is 1-alkyl-2-(l-hydroxyethyl)-tetrahydropyrimidine, in which the alkyl is derived from tallow and contains predominantly 16 to 18 carbon atoms. The additive was prepared by refluxing about 200 g. (0.3 hydroxyl equivalents plus slight excess) and 6.18 g. (0.1 mole plus 0.3 excess) of boric acid in 100 g. of benzene. The refluxing was continued for about 9 hours, after which time a total of 6 cc. of water was collected. Following completion of the reaction, the reaction mixture was filtered and the solvent was evaporated at 170 C. under water pump vacuum. The product had a basic nitrogen of 1.77 meq./g. and a boron content of 0.37%. Here again it is believed that the triester was formed and is of the following structure:

Here again, the hydrogens attached to the carbon atoms have been omitted in the interest of simplicity.

EXAMPLE XVII As hereinbefore set forth the additive of the present invention also is particularly applicable for use to stabilize fuel oil. One method of evaluating fuel oil is by color stability. The method used in this example is AST M D- 1500, in which a rating of 8 is practically black and lower numbers are proportionately lighter. The samples are run in a No. 2 fuel oil and the color is determined in a Lumitron Colorimeter. A control sample of the fuel (not containing an additive), when evaluated in the above manner had a rating of 8. Another sample of the fuel oil containing 48 parts per million of the boron ester prepared as described in Example XV, when evaluated in the above manner, had a color rating of 5.5 Another sample of the fuel oil contained 44 parts per million of the boron ester and 8.8 parts per million of a copper deactivator (disalicyla1 diaminopropane). This sample also had a color rating of 5.5. Still another sample of the fuel oil contained 88 parts per million of the boron ester and 8.8 parts per million of the copper deactivator. This sample had a color rating of 3.

In addition to the color rating, sediment formed during the evaluation was filtered off and measured. The control sample had a sediment of 13.4 mg./ ml. The samples containing both the boron ester and metal deactivator had sediment contents of 4.1 and 4.3 mg./l00 ml., respectively.

EXAMPLE XVIII The additive prepared as described in Example XV also was evaluated in No. 2 fuel oil according to the method referred to as the Socony Mobil Anti-Screen Clogging Test. In general, this method comprises forming an emulsion of carbon black, oil and water. The emulsion then is circulated at room temperature through a screen, after which the carbon black accumulated on the screen is washed off and measured. The results are rated on the basis of the percent of carbon black dispersed, which is the difference between the amount of carbon black retained on the screen as compared to the amount of carbon black used in forming the emulsion.

A sample of the emulsion containing 25 p.p.m. of the boron ester prepared as described in Example XV was in Example XVI. This sample also had a rating of 96%.

In another evaluation, the sample of emulsion contained 25 p.p.m. of the additive prepared as described in Example XVI. This sample also had a rating of 96%. The results of Examples 17 and 18 demonstrate the potency of the additives of the present invention to stabilize fuel oil.

I claim as my invention:

1. Organic substance normally subject to oxidative deterioration containing, as a stabilizer against such deterioration, from about 0.001% to about 5% by weight of a boron ester of a hydroxyalkyl-heterocyclic compound, at least one valence of the boron atom being satisfied by a bond between the boron and the oxygen of said hydroxyalkyl group, said compound being:

(a) N hydroxyalkyl-menonitrogen-heterocyclic compound free of unsaturation in the heterocyclic ring and selected from the group consisting of piperidine, pyrrolidine, hydrogenated indole, hydrogenated carbazole, hydrogenated quinoline and hydrogenated acridine, the hydroxyalkyl group containing up to about 8 carbon atoms; or

(b) N hydroxyalkyl N hydrocarbyl polynitrogen-heterocyclic compound, the hydroxyalkyl group containing up to about 8 carbon atoms, the hydrocarbyl being alkyl containing from 3 to about 20 carbon atoms or cycloalkyl containing from 4 to 12 carbon atoms in the ring, and the heterocyclic compound being free of unsaturation in the heterocyclic ring and being selected from the group consisting of piperazine, hexahydropyrimidine, hexahydropyridazine, imidazolidine, pyrazolidine, hydro genated triazole and hydrogenated phenazine; or (c) N hydroxyalkyl heterocyclic unsaturated compound selected from the group consisting of pyridine, dihydropyridine, tetrahydropyridine, pyrimidine, dihydropyrimidine, tetrahydropyrimidine, pyrazine, dihydropyrazine, tetrahydropyrazine, pyridazine, dihydropyridazine, tetrahydropyridazine, 1,2,3-triazine, dihydro 1,2,3 triazine, indole, dihydroindole, tetrahydroindole, quinoline, dihydroquinoline, tetrahydroquinoline, carbazole, dihydrocarbazole, tetrahydrocarbazole, hexahydrocarbazole, octahydrocarbazole, acridine, dihydroacridine, tetrahydroacridine, hexahydroacridine, octahydroacridine, phenazine, dihydrophenazine, tetrahydrophenazine, heXahYdmphenazine and octahydrophenazine, the hydroxyalkyl group containing up to about 8 carbon atoms; or (d) hydroxyalkyl N hydrocarbyl heterocyclic compounds in which the hydroxyalkyl contains up to about 8 carbon atoms and is attached to a nuclear carbon of the heterocyclic ring, the hydrocarbyl is C -C alkyl or C C cycloalkyl, and the heterocyclic compound is selected from the group consisting of those set forth in paragraphs (a), (b) and (c) above. 2. The substance of claim 1, wherein said compound i a boron ester of N-hydroxyalkyl-N'-alkyl-piperazine.

3. The substance of claim 1, wherein said boron ester is a borate of N-hydroxyethyl-N'-sec-octyl-piperazine.

4. The substance of claim 1, wherein said boron ester is a borate of N-hydroxyalkyl-N'-cycloalkyl-piperazine, the cycloalkyl containing from 4 to 12 carbon atoms in the ring.

5. The substance of claim 4 wherein said boron ester is a borate of N-hydroxyethyl-N'-cyclohexyl-piperazine. 6. The substance of claim 1 wherein said boron ester is a borate of N-hydroxyalkyl-N-alkyl-hexahydro-pyrimidine.

7. The substance of claim 1 wherein said boron ester is 16 a borate of N-hydroxyalkyl-N-cycloalkyl-hexahydropy rimidine.

8. The substance of claim 1 where said boron ester is a borate of N-hydroxyalkyl-N'-alkyl-hexahydropyridazine.

9. The substance of claim 1 where said boron ester is a borate of N- hydroxyethyl-N-sec-alkyl-hexahydropyridazlne.

10. The substance of claim 1 wherein said boron ester is a borate of an N-hydroxyalkyl-imidazoline.

11. The substance of claim 10 wherein said borate is a borate of 1-hydroxyethyl-2-alkyl-imidazoline.

12. The substance of claim 1 wherein the hydroxyalkyl group is attached to a nuclear carbon atom.

13. The substance of claim 12 wherein said boron ester is a borate of 1-alky1-2-hydroxyalkyl-tetrahydropyrimidine.

14. The substance of claim 13 wherein said boron ester is a borate of l-alkyl of 16 to 18 carbon atoms-2(1-hydroxyethyl)-tetrahydropyrimidine.

15. The substance of claim 1 being plastic.

16. The substance of claim 15 being solid polyolefins.

17. The substance of claim 1 being hydrocarbon distillate.

18. The substance of claim 17 being gasoline.

19. The substance of claim 17 being kerosene.

20. The substance of claim 17 being fuel oil.

References Cited UNITED STATES PATENTS 2,721,181 10/1955 Lawrence et al 25249.6 2,878,256 3/1959 Hunter et a1 44-63 x 3,102,871 9/1963 Spacht 44-63 X DANIEL E. WYMAN, Primary Examiner W. J. SHINE, Assistant Examiner US. Cl. X.R.