US2627474A - Rust preventive compositions containing a wax-soap base - Google Patents

Description

'terials for oxidation treatment.

Patented Feb. 3, 1953 RUST PREVENTIVE COMPOSITIONS CON- TAINING A WAX-SOAP BASE Joseph W. Romberg, Port Neches, Tex., assignor to The Texas Company, New York, N. Y., a

corporation of Delaware No Drawing. Application November 8, 1949, Serial No. 126,248

3 Claims.

This invention relates to oil compositions of metallic soaps of oxidized parafiins adapted as coatings to prevent rusting of ferrous and nonferrous metals and contemplates the incorporation of silicones in the compositions.

Certain rust preventive compositions are composed of oil solutions of metallic soaps of the hydrocarbon derivatives of the partial oxidation of parafiin base hydrocarbons cutback with solvents such as naphtha to form liquid materials adapted to be applied to metal surfaces. After the composition is applied to the metal surface, the solvent evaporates leaving an oil soap film which adheres to the metal and protects it from rusting. It is desirable that the evaporation of the solvent shall leave a non-tacky film adherent to the metal. The present invention is based on the discovery that the addition of very small proportions of silicone to the oil soap composition greatly accelerates the evaporation of the solvent and the drying of the composition on the metal surface.

The invention accordingly contemplates a method of decreasing the drying time of these antirust soap compositions by the incorporation of silicone therein and the preparation of quick drying soap compositions containing silicone which are adapted to be applied to metal surfaces to prevent rusting.

In accordance with the invention acidic constituents formed by the partial oxidation of parafiin hydrocarbons are saponified with metal oxides or hydroxides to produce mixtures of metallic soaps and para-fiin hydrocarbons, a plasticizing agent is added to the-oil-soap prod- .uct, the mixture is cutback with a solvent and a small proportion of silicone is incorporated in the mixture. The composition consists largely of the soap mixture and a solvent such as naphtha with a small proportion of a plasticizing agent and relatively minute proportions of silicone.

The oxidation products used in the practice of the invention are obtained from the partial oxidation of paraifin wax, preferably from the partial oxidation of oil wax mixtures, such for example, as crude scale wax and slack wax. Crude scale wax will contain some 3-5% of oil and slack wax will contain some -20% of oil; such oil-wax mixtures are well adapted as the ma- The partial oxidation products of these oil wax mixtures yield upon saponification soap mixtures which are even more satisfactory in the final composition than when made from practically pure paraflin wax.

The soaps may be prepared with various metal oxides or hydroxides. In view of thejsuperior anti-rust properties of litharge orred lead, this lead oxide is apreferred ingredient for the soap preparation. Usually, however, it is desirable to employ a modifying soap with the lead soap.

'Thus, the lead soap of oxidized wax may produce a soap which is too soft for some purposes and on the other hand a calcium soap of the oxidized wax produces a very high melting point soap which tends to be crumbly. By adding a relatively small portion of the calcium soap to the lead soap a very satisfactory soap mixture may be obtained; for instance, by adding sufficient calcium hydroxide to the litharg'e for re action with the oxidized paraffins to give a soap of 155 F. melting point, a very satisfactory material was obtained. In general, the saponification number of the soap product should not exceed about 200 since soaps with higher saponification numbers are less readily cut with the naphtha solvent.

The solvent employed in the mixture is a petroleum distillate having the general distillation characteristics of not less than about per cent over at 350 F. with end points approximating 400 to 410 F. In view of safety regulations, it is desirable that the flash of the naphtha be not lower than about 100 F. on the Tagliabue closed cup.

The anti-rust composition will contain about 40 to 50 per cent by weight of thesoap orsoaps of the oxidized paraiiins and approximately 45 to per cent by weight of the naphtha solvent.

It is desirable to incorporate a plasticizer in the composition in order to provide flexibility, particularly to prevent cracking, checking or peeling of the film. at low temperatures. The plasticizer is a high boiling and high flash petroleum residual oil of the type known as cylinder stock. The cylinder stock is added to the composition in relatively small proportions of the order of about 5 per cent by weight.

The silicones useful for the purposes of the present invention include the polymeric organic silicon oxide condensation products. These products are sometimes referred to as organo siloxanes. structurally these compounds are composed essentially of a plurality of silicon atoms linked together through oxygen atoms with each silicon atom having attached to it at least one organic radical. The oily liquid condensation products obtained by the polymerization of organosilane diols (each silicon atom having attached two organic radicals) such as, for example, the dimethyl silicones, are especially well adapted for the purposes of the present invention. The silicone is added in comparatively minute proportions, a mere fraction of a per cent, and functions to greatly increase the drying rate of the composition.

Metallic soap waxate cutbacks, without the addition of the silicones, will frequently retain the solvent for a considerable length of time. It is common for these waxate cutbacks to leave soft films on the metal after 24 hours and sometimes longer periods. It appears that with these compositions there may be the formation of a skin which retards further drying. The addition of the silicone greatly accelerates the drying rate so as to yield a firm dry film in a matter of two or three hours.

By way of example, a composition was prepared containing the following ingredients, the proportions being by weight:

Per cent Lead calcium .soap of oxidized slack wax 45 Cylinder stock 5 Stoddard solvent 50 This mixture upon being subjected to the drying test was not completely dry in 24 hours. Two compositions containing silicone polymer were composed of the following ingredients, the proportions being by weight:

Per cent Lead calcium soap of oxidized slack wax 44.9 46.9 Cylinder stock 5.0 5.0 Dimethyl silicone 0.1 0.1 Stoddard solvent 50.0 48.0

These mixtures upon being given the dryin test were dry in two hours. The silicone incorporated in the mixtures Was a dimethyl silicone polymer obtained from the Dow Corning Corporation under the trade name of 200 Dow Corning Fluid and having a viscosity of 1,000 centipoises.

The effect of the silicone in reducing the drying time of the soap waxate cutbacks is synergistic. Thus, when the silicone is added to the naphtha solvent itself, there is no effect on the flash point of the solvent. It would be expected therefore that the addition of the silicone to the metallic soap waxate naphtha composition would not effect the evaporation of the solvent in the mixture. But the fact is that the addition of the silicone to the soap waxate naphtha mixture does produce the unexpected result of greatly accelerating the evaporating rate.

In a series of tests it was found that additions of the dimethyl silicone polymer in amounts as low as 0.001 per cent by Weight gave definite improvement in the drying time and that increased percentages of 0.01 per cent and 0.03 per cent produced increased effects in reducing the drying time. The maximum reduction in drying time was obtained with about 0.1 per cent of the silicone. This small percentage gives such satisfactory results that there appears to be no need of increasin the proportion of silicone above this small amount. Viscosity difierences in the silicone polymers do not appear to have any material effect on the drying time. Thus in comparing a dimethyl silicone having a viscosity of 100 centipoises with one having a viscosity of 1,000 centipoises it was found that there was no material difference in effect on the drying time.

When applying these oil compositions of metallic soaps of oxidized paraffins to metal surfaces,

non-tacky protective films are formed on the surfaces upon the drying of the solvent. These compositions are well suited for antirust compositions in cases where very thin films of protective coating are desired; thus, for example, these compositions may be used in producing adherent films having a thickness of the order of 0.002 inch.

I claim:

1. A quick drying liquid composition adapted for application to metal surfaces to prevent rusting that comprises as essential ingredients about 40-50% by weight of a waxate consisting of a wax-soap composition composed of metallic soaps of the acids of oxidized paraffin wax and the associated non-acid constituents thereof, about 5% by weight of petroleum cylinder stock as plasticizer, about 45-55% by weight of naphtha and a relatively minute portion of the order of 0.001- 0.1% by weight of liquid dimethyl silicone effective to decrease the dryin time of the composition when applied to metal surfaces, said composition being adapted upon the volatization of the naphtha to leave a non-tacky, adherent film on the metal surface.

2. A quick drying liquid composition adapted for application to metal surfaces to prevent rusting that comprises as essential ingredients about 40-50% by weight of a waxate consisting of an oil-wax-soap composition composed of metallic soaps of the acids of an oxidized paraffin wax-oil mixture and the associated non-acid constituents thereof, about 5% by weight of petroleum cylinder stock as plasticizer, about 45-55% by weight of naphtha and a relatively minute portion of the order of 0.001-0.1% by weight of liquid dimethyl silicone effective to decrease the drying time of the composition when applied to metal surfaces, said composition being adapted upon the volatization of the naphtha to leave a non-tacky, adherent film on the metal surface.

3. A quick drying liquid composition adapted for application to metal surfaces to prevent rusting that comprises as essential ingredients about 40-50% by weight of a waxate consisting of an oilwax-soap composition composed of the leadcalcium soaps of the acids of oxidized slack wax and the associated non-acid constituents thereof, about 5% by weight of petroleum cylinder stock as plasticizer, about 45-55% by weight of naphtha and a relatively minute portion of the order of 0.001-0.1% by weight of liquid dimethyl silicone effective to decrease the drying time of the composition when applied to metal surfaces, said composition being adapted upon the volatization of the naphtha to leave a non-tacky, adherent film on the metal surface.

JOSEPH W. ROMBERG.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,242,837 Shields May 20, 1941 2,375,007 Larsen et a1. May 1, 1945 2,421,672 Wilson et a1 June 3, 1947 2,453,816 Schindler et a1 Nov. 16, 1948 2,456,642 Merker Dec, 21, 1.948

FOREIGN PATENTS Number Country Date 600,693 Great Britain Apr. 15, 1948

Claims (1)

1. A QUICK DRYING LIQUID COMPOSITION ADAPTED FOR APPLICATION TO METAL SURFACES TO PREVENT RUSTING THAT COMPRISES AS ESSENTIAL INGREDIENTS ABOUT 40-50% BY WEIGHT OF A WAXATE CONSISTING OF A WAX-SOAP COMPOSITION COMPOSED OF METALLIC SOAPS OF THE ACIDS OF OXIDIZED PARAFFIN WAX AND THE ASSOCIATED NON-ACID CONSTITUENTS THEREOF, ABOUT 5% BY WEIGHT OF PETROLEUM CYLINDER STOCK AS PLASTICIZER, ABOUT 45-55% BY WEIGHT OF NAPHTHA AND A RELATIVELY MINUTE PORTION OF THE ORDER OF 0.0010.1% BY WEIGHT OF LIQUID DIMETHYL SILICONE EFFECTIVE TO DECREASE THE DRYING TIME OF THE COMPOSITION WHEN APPLIED TO METAL SURFACES, SAID COMPOSITION BEING ADAPTED UPON THE VOLATIZATION OF THE NAPHTHA TO LEAVE A NON-TACKY, ADHERENT FILM ON THE METAL SURFACE.