WO1987007627A1

WO1987007627A1 - Corrosion-inhibiting coating compositions for metals

Info

Publication number: WO1987007627A1
Application number: PCT/US1987/001322
Authority: WO
Inventors: Harold H. Christhilf; Steven D. Clark
Original assignee: Witco Corporation
Priority date: 1986-06-12
Filing date: 1987-06-04
Publication date: 1987-12-17
Also published as: EP0309472A4; JPH02500450A; EP0309472A1

Abstract

An anticorrosive composition comprising an inorganic-organic complex in the form of a solution and/or a colloidal dispersion in a volatile organic solvent of a thixotropic overbased alkaline earth metal, e.g., calcium, organic sulfonate, complexed with an alkaline earth metal, e.g., calcium carbonate; and a synthetic drying oil such as long oil alkyds, or a mixture of said synthetic drying oil with a natural drying oil (modified or unmodified) such as linseed oil or bodied linseed oil, said synthetic drying oil constituting from about 15 to 60 wt % of said composition; or where said natural drying oil is used to constitute up to 4O wt. % of the synthetic drying oil, and a paint drier.

Description

CORROSION-INHIBITING COATING COMPOSITIONS FOR METALS

DESCRIPTION

Technical Field

Our present invention is concerned with the preparation of novel liquid corrosion-inhibiting coating compositions, of the type hereafter described, which are effective, when applied in thin films on ferrous and non-ferrous, particularly ferrous, metals and steels, and which, when dried and/or cured, form hard, non-tacky dry films, which are highly effective for the prevention or inhibition of corrosion or rusting of such of said metals which are susceptible to corrosion or rusting.

Background Prior Art

Over a period of a great many years, numerous coating compositions have been proposed, and many of which have been used commercially, for the coating of ferrous and non-ferrous metals, which are susceptible to rust or corrosion, to prevent or to inhibit such rust or corrosion. As has long been known, rust or corrosion is caused by environmental conditions, such as contact of the metal surfaces by water; by air, particularly moist air; and by various ' chemicals or other materials which come into contact with the metal surfaces. While, in most cases, ferrous metals such as iron and steels represent the areas where rust and corrosion problems are particularly encountered, various non-ferrous metals, for instance, aluminum, are also subject to corrosion. The corrosion-inhibiting compositions which have been suggested, or which have been or are currently being commercially used, fall, generally speaking, into two classes, one being compositions which form coatings in relatively thin films and which are soft, and are commonly of a character such that they may readily be stripped off or removed from the metal surfaces, for example. by organic solvents, where it is necessary to remove the coatings at periodic intervals to carry out repairs or the like on the metal surfaces, after which they are recoated; and the other comprises compositions which form coatings in relatively thin films and which are hard and of a character such that they are, and are intended as, essentially permanent coatings and are removable only with great difficulty.

Since the coating compositions of our present invention are of the type which involve the use of inorganic-organic complexes which comprise thixotropic overbased alkaline earth metal organic sulfonates complexed with inorganic alkaline earth metal carbonates, as one of the essential ingredients of 3aid coating compositions, it is to be noted that the prior art has long known of such inorganic-organic complexes, and of corrosion-inhibiting coating compositions which contain, as one of the ingredients thereof, the aforesaid inorganic-organic complexes.

The use as corrosion-inhibiting coating compositions, which contain thixotropic, or grease-like or gel-like thixotropic, alkaline earth metal organic sulfonates complexed with alkaline earth metal carbonates, with or without admixture with polymers, petrolatums, microcrystalline or other waxes, plasticizers, and resins, in a carrier or diluent of non-volatile or volatile (or mixtures of non-volatile and volatile) hydrocarbons and/or other organic liquid solvents, is well-known to the art and is disclosed in such U.S. Patents as Nos. 3,925,087; 3,45-3,124; 3,492,231; 3,565,672; 3,565,843; 3,661,622; 3,746,643; 3,816,310; and 4,495,225, and other patents referred to in the specifications of such patents. Various of such corrosion-inhibiting compositions are known to have a certain utility for a variety of purposes, some including float coating or flotation coating of the insides of tanks, e.g., ballast tanks for ships, barges, off-shore oil rigs, etc., wherein, for instance, the tank is filled with water, the lighter-than-water corrosion-inhibiting composition is poured onto the surface of the water, and the water is then drained from the tank, and the floating layer of anti-corrosion agent deposits on the .side walls and bottom of the tank as the water drains out. Other uses for various of said corrosion-inhibiting compositions include, for instance, automobile and truck body undercoatings, maintenance coatings, and others for use in other environments.

Patent No. 3,925,087 discloses corrosion-inhibiting compositions which comprise (a) about 10 to about 30% by weight of a rust-inhibitive grease-like concentrate comprising a thixotropic inorganic-organic complex stably dispersed in an essenti-all inert liquid oil phase in an amount not to exceed 4 parts, per part of said complex, said inorganic-organic complex comprising a thixotropic overbased alkaline earth metal, particularly calcium, organic sulfonate complexed with calcium carbonate; (b) about 2 to about 10%, by weight, of a drying oil, particularly tung oil, or synthetic drying oil, said drying oil or synthetic drying oil being misσible with a diluent oil selected from the group consisting of aliphatic hydrocarbon diluents, cycloaliphatic hydrocarbon diluents, aromatic hydrocarbon diluents, and mixtures thereof boiling at temperatures above 150° C; and (c) from at least 60% by weight to essentially the balance of said compositions being such diluent oil.

The said Patent No. 3,925,087 expressly states, in Column 6, Lines 36-43, that "too much of the drying oil apparently leads to the formation of cracks in the skin * * *." From 3 to 9% by weight of drying oil is adequate, 6-8% by weight b'eing preferred.

The said Patent No. 3,925,087 also makes reference, in Column 1, last paragraph, leading over through Line 21 of Column 2, to one commercial source of inorganic-organic complex compositions which comprise gel-like thixotropic overbased calcium organic sulfonates complexed with calcium carbonate, which compositions contain, or may contain, a petroleum resin or a wax or the like, all distributed throughout a hydrocarbon solvent. Reference is made to products commercially sold under the trademark "SACI", two of such "SACI" products, namely, "SACI"-200 and "SACI"-300, being specifically disclosed as exemplary of such "SACI" products. ("SACI" is a registered trademark and has been owned by Witσo Corporation, New York, New York, since 1973). Such "SACI" products are stated to constitute formulations containing the aforementioned thixotropic overbased calcium organic sulfonates complexed with calcium carbonate, namely, the inorganic-organic complexes used as one of the ingredients of the corrosion-inhibiting compositions of said Patent No. 3,925,087, but that the "SACI" products generally are not the inorganic-organic complexes per se. The patent discloses the use of the "SACI"-200 and "SACI"-300 products, as they are commercially marketed and sold, in the production of the corrosion-inhibiting or rust-inhibiting compositions of said patent.

In Column 4, Lines 40-56, of said patent, it is pointed out that, since typical grease-like concentrates of the inorganic-organic complex, e.g., such as the "SACI" products, contain more than 25%, and typically 50-70%, by weight of the complex per se, the proportions of the essential ingredients of the corrosion-inhibiting compositions of the invention of said patent, can be restated as follows: a. about 5 to 15% by weight of the inorganic complex; b. about 2 to about 10% by weight of the drying oil; and c. essentially the balance to 100% (e.g., at least 75% by weight) of hydrocarbon oil diluent. It then states that the active ingredients, expressed in such manner, are in a _fc complex/drying oil ratio of about 1:1-3:1; and that dilution of the active ingredients to, for example, the 50-300 cps level, permits deposition of at least 1.0 gram of these active ingredients per square meter of metal to be protected.

The said Patent No. 3,925,087 contains 25 Examples, exclusive of four Examples (C-l to C-4) which contained only a "SACI" product and a naphthenic oil, without any drying oil, as Control Formulations; of the Nos. 1 to 25 Examples, some contain only a naphthenic oil solution of tung oil without any "SACI"; others contain a naphthenic oil solution of "SACI"-200, or "SACI"-300 (Examples 2 and 17-19) and tung oil with no drier, falling withi-n the scope of the invention of said patent; others contain a naphthenic oil solution of "SACI"-200 and linseed oil, with or without driers, apparently falling within the scope of said invention; and others comprise a naphthenic oil solution of "SACI"-200, and tung oil in amounts of 20 and 30 wt.% of the formulation (Examples 14 and 15) and falling outside of the scope of the invention of said patent. The patent also states that the corrosion-inhibiting compositions of the invention thereof may contain petroleum resins or waxes, which may be added, or which-may be present in the particular "SACI" product utilized, as, for instance, "SACI"-300 (see Column 1, last paragraph thereof, and Example 2). The compositions 14, 15 and 16, shown in the last paragraph of Column 8 of Patent No. 3,925,087, disclose, respectively, the following formulations:

Ingredient In Per Cent By Weight

Naphthenic "SACI" Tung

Example Oil 200 Oil

14 75.0 5.0 20

15 65.0 5.0 30

16 75.0 15.0 10

By reference to Table I in Column 10 of said patent, Saltspray Tests of the aforementioned Examples 14, 15 and 16 show time periods of 5, 6 and 28 hours, respectively, before Failure, which are tantamount to utter failure or inoperativeness of such compositions in corrosion resistance in standard Saltspray tests. Indeed, in the file wrapper contents of Patent No. 3,925,087, in the AMENDMENT filed March 10, 1975, in the first paragraph at Page 9 of said AMENDMENT, reference is specifically made to "increasing the proportion of tung oil" at the expense of the "SACI" also results "in rapid failure of the coating", specific reference being made to the aforesaid Examples 14-16 of said Patent. Indeed, even with as high as 10% of tung oil in admixture with the naphthenic oil and the "SACI"-200 (Example 16 of the Patent) Saltspray test failure occurred at the end of 28 hours which, as the same AMENDMENT states on the same Page 9, showed a "substantial falling off of the performance when the amount of drying oil exceeds the claimed maximum level" (to-wit, 10% tung oil), it being asserted that the amount of tung oil be "about 10% or less, more preferably about 9% or less." Even Examples 5, 6 and 7 showed Saltspray test results which, from a practical standpoint, were commercially valueless in contrast to the corrosion-inhibiting compositions of Examples 1, 2 and 3, and other compositions presumably forming a part of the invention of said Patent but with hardly effective Saltspray test values.

The corrosion-inhibiting compositions of said Patent are stated to form solid protective coatings which are soft or tacky, rather than brittle, and have little or no tendency to crack. They are stated to be particularly adapted for the coating of the inside of tanks and can be applied by spraying but are best applied by a flotation coating procedure, and that they possess the advantageous property of the entire protective coating on a metal surface of said corrosion-inhibiting compositions being easily stripped off with unheated degreasing solvents.

With regard to the disclosures of the aforementioned prior art patents, Nos. 3,453,124 and 3,565,843, which patents are referred to in Column 2 of said Patent No. 3,925,087, said patents are disclosed as describing, illustratively, what said Patent No. 3,925,087 refers to as the rust-inhibitive, grease-like concentrate comprising the thixotropic inorganic/organic complex stably dispersed in an essentially inert liquid oily phase constituent of the corrosion-inhibiting compositions of the invention of said Patent No. 3,925,087. A more complete discussion of the disclosure of said Patent Nos. 3,453,124 and 3,565,843, as well as the other above-cited patents, is believed to be here in order and is noted below.

Patent No. 3,453,124 discloses, among other things, the preparation of inorganic-organic complexes in the form of thixotropic overbased alkaline earth metal (such as calcium) organic sulfonates complexed with alkaline earth metal (such as calcium) carbonates, dispersed, in the form of colloidal particles, in oil carriers such as mineral oils or other non-volatile carriers or media, as well as other carriers or media which are volatile, such as mineral spirits, and, also, mixtures of non-volatile and volatile carriers or media. It also discloses corrosion-inhibiting coating compositions for the treatment of ferrous and non-ferrous metals which comprise, as essential components of the invention of said patent, reaction products of the aforesaid inorganic-organic complexes, colloidally dispersed in said carriers or media, with phosphoric acid esters of alcohols. In Column 40, Lines 48-75, of said patent, it is stated that particularly useful corrosion-inhibiting compositions are obtained when certain types of hydrocarbon resins are added to the aforesaid reaction products, in that said resins impart to the coating compositions the property of forming coatings on the metals which are firm rather than being soft and greasy, firm coatings being advantageous because they provide additional resistance to abrasion, dirt pickup, gravel pickup, etc.; and they avoid the disadvantages of soft grease-like coatings which are easily removed by contact of such coatings by humans and animals.

The said Patent No. 3,453,124 also discloses, in Columns 43 and 44, the results of comparative corrosion tests with illustrative corrosion-inhibiting compositions of said patent and with commercial automobile undercoating compositions, which latter include an identified petrolatum undercoating composition; an undercoating composition not specifically identified, but stating that it comprised SAE 40 oil, a rust-inhibitor, and a drying oil; a petroleum base translucent film (otherwise unidentified); and an asphalt cutback undercoating composition (also otherwise unidentified) ; in which comparative tests of corrosion-inhibiting compositions made in accordance with the claimed invention of said patent are shown to be superior to those corrosion-inhibiting compositions with which comparison was made.

Patent No. 3,492,231 discloses methods for the preparation of the inorganic-organic complexes and their utility in the production of corrosion-inhibiting compositions for use on metals. Various of such inorganic-organic complexes have long been known to the art, and they are illustrative of certain of the many compositions which heretofore have been known to the art dealing with corrosion-inhibiting compositions containing said complexes.

Patent No. 3,565,672 discloses methods for the preparation of mineral oil solutions of inorganic-organic complexes, which are disclosed as possessing utility as corrosion-inhibitors, the complexes, as such, being but one of the ingredients which can be used in the particular combination of ingredients which, in certain proportions, constitute the novel and highly-improved corrosion-inhibitor compositions of our present invention.

Patent No. 3,565,843 discloses organic rust-inhibiting compositions which form hard coatings which are almost tack-free to the touch by spraying on metal surfaces, which compositions comprise (a) about 10 to 35 wt.% of an inorganic-organic complex in the form of an overbased alkaline earth metal organic sulfonate which has been admixed with aqueous ammonia under conditions to form a gel, which is, in fact, a thixotropic gel; (b) about 5 to 15 wt.% of a coating material selected from the group consisting of a hydrocarbon polymer resin and a combination of a hydrocarbon polymer resin, an ethylene-vinyl acetate copolymer having a specified melt index, and a wax, and wherein said hydrocarbon polymer resin has a specified molecular weight and a specified softening point; and (c) about 55 to 85 wt.% of a hydrocarbon solvent having a boiling point range of about 270° to 450° F.

Patent No. 3,661,622 discloses, among other subject matter, the preparation of thixotropic overbased alkaline earth metal, particularly calcium, organic sulfonates, complexed with an alkaline earth metal, particularly calcium, carbonate; the admixture therewith of certain polymers such as low-density polyethylene, polypropylene, etc.; copolymers of the foregoing with vinyl monomers such as ethylene-vinyl acetate; polymethyl methacrylate and others; and the preparation of corrosion-inhibiting primer coating compositions containing the aforesaid ingredients. The inclusion of the polymers, as is pointed out in Column 11, Lines 45-65, serves, among other functions, to produce films which are harder, tougher and less tacky than primer compositions which do not contain such polymers. The primer compositions are stated to be desirably applied to metal surfaces to be coated in the form of a volatile organic solvent solution, said primer composition solution being applied by brush coating or by spraying, and evaporating the volatile organic solvent from the primer composition film, after which a conventional paint is applied.

Patent No. 3,746,643 discloses viscous, high-melting point corrosion- or rust-inhibiting coating compositions for metals which comprise a solution in a volatile hydrocarbon solvent, such as Stoddard solvent, which solution may also contain some mineral oil, of an inorganic-organic complex in the form of a thixotropic overbased alkaline earth metal organic sulfonate complexed with an alkaline earth metal carbonate, and which coating compositions contain certain proportions of macrocrystalline wax. The novelty in this patent resides in the incorporation of macrocrystalline wax into the composition, which imparts an unexpected marked increase in the resistance to rusting of dip-coated steel panels, as demonstrated by Weatherometer testing, over similar coating compositions not containing microcrystalline wax, or over similar coating compositions containing ordinary paraffin waxes.

Patent No. 3,816,310 discloses methods for the preparation of coating compositions which have particular utility as rust-inhibitors, as well as rust-inhibitor greases. This patent discloses methods of preparing inorganic-organic complexes in the form of thixotropic overbased alkaline earth metal, particularly calcium, organic sulfonates, complexed with an alkaline earth metal, particularly calcium, carbonate, dissolved or dispersed in a non-volatile carrier, such as mineral oils, or a volatile organic solvent, such as Stoddard solvent, or a mixture of non-volatile carriers and volatile - organic solvents. Compositions made in accordance with this patent can be applied, by spraying or painting, to a metal surface to coat said surface and protect it against rusting, and it is stated that such

-15-

compositions have particular utility for rust-proofing automobile underbodies.

It has also been known to the art, as shown by U.S. Patent No. 4,150,192, to prepare corrosion-inhibitor compositions or rust-inhibitors which comprise mixtures containing thixotropic overbased calcium sulfonate/σalσium carbonate complexes; oxidized petrolatums; non-volatile diluent oils exemplified by mineral oils; microcrystalline waxes; particulate fillers such as powdered aluminum, basic lead silico-chromate, zinc molybdate, and the like; hydrocarbon-derived thermoplastic resins; silica pigments; and plasticizers. Such corrosion-inhibiting compositions, as prepared and used, are in the form of hot-melt compositions and are radically different from the corrosion-inhibiting compositions of our present invention not only because they are hot-melt compositions but, also, because the compositions set instantly, for instance, within about 10 seconds, on the ferrous metal substrate and the coatings formed are soft. For numbers of important uses to which the corrosion-inhibiting compositions of our present invention are particularly advantageous and highly effective, as, for instance, as pipe varnishes in steel mills which produce steel pipe, the compositions of said patent would have no commercial utility; and the same is true in regard to many other uses which the corrosion-inhibiting ^• compositions of our present invention are especially satisfactory and for which uses the compositions of said patent would be of no commercial value.

Patent No. 4,495,225, which is generally somewhat related to the above-mentioned Patent No. 3,925,087, discloses corrosion-inhibiting compositions which contain a corrosion-inhibiting grease-like concentrate of a thixotropic overbased calcium sulfonate-calcium carbonate complex dispersed in a mineral oil, the mineral oil constituting from 20 to 60 wt.% of the compositions; from about 5 to 25% of a drying oil; and specified low ranges of special drier compositions, to-wit, those selected from two different groups of driers, namely, (1) a first metal drier selected from the group consisting of copper carboxylate compounds, rare earth carboxylate compounds and mixtures thereof, and (2) a second metal drier consisting of zinc carboxylate compounds. At the bottom of Column 2, last three lines, leading over to Column 3, this patent states that the coating compositions of said patent cure to a "solid but soft protective layer. " The patent discloses that the corrosion-inhibiting comositions of this patent may contain petrolatums, oxidized petrolatums, hydrocarbon diluent oils, polyisobutylenes to provide improved adhesion to.metal surfaces, pigments such as aluminum pigments and carbon black, and skin-preventing agents.

In addition to the disclosure in the aforementioned Patent Nos. 3,925,087 and 4,495,225 of certain "SACI" products as commercial sources of products for or containing the known rust-inhibiting thixotropic inorganic-organic complexes used as one of the ingredients in the preparation of the novel corrosion-inhibiting compositions of ^' our present invention, there are also known to the art other "SACI" corrosion-inhibiting products which contain as an ingredient thereof thixotropic inorganic-organic complexes of the type which are disclosed in the particular "SACI" products which are referred to in Patents Nos. 3,925,087 and 4,495,225, some of which "SACI" products can also conveniently be used in the preparation of the novel corrosion-inhibiting compositions of the present invention. Such additional "SACI" products are disclosed in various Technical Data sheets dealing with various "SACI" products.

We refer below to Technical Data sheets with respect to various other "SACI" products, which contain, as one of the ingredients thereof, thixotropic overbased calcium organic sulfonate/σalcium carbonate complexes, independently of the matter of convenience or inconvenience of the use or attempted use thereof, as a practical matter, as a source of said complexes for use of said complexes in accordance with our present invention.

With further respect to the Technical Data sheets in regard to those products identified as "SACI"-100 and 100A, "SACI"-200 and 200A, "SACI"-300 and 300A, "SACI"-2400, "SACI"-2452 and "SACI"-2460, except as noted hereafter, the aforesaid "SACI" products contain a thixotropic overbased calcium organic sulfonate/calcium carbonate complex colloidally dispersed in a volatile hydrocarbon solvent (mineral spirits), or in a paraffinic mineral oil, or in a mixture of said mineral spirits and said mineral oil. The organic sulfonate part of the thixotropic overbased calcium organic sulfonate-calσium carbonate complexes of the aforesaid "SACI" products is derived from the use of branched chain or linear/straight chain monoalkylbenzene or dialkylbenzene sulfonic acids or mixtures of such sulfonic acids, the alkyl radical or radicals each containing at least 12 carbon atoms and generally in the range of from 12 to 30 carbon atoms.

^IISACI"-100 and 100A concentrates are colloidal dispersions of said complex in a mixture of mineral spirits and a paraffinic mineral oil. "SACI"-100A also contains oxidized petrolatums for improved anti-corrosion properties. "SACI"-100 products contain 60, 50 or 40 wt.% solids. Coatings made with its listed basic compositions are generally stated to be formulated with waxes (refined and unrefined); petrolatums; oxidized petrolatums, those having an Acid No. of 15-20 being recommended; pigments; resins; and asphalts. Coatings made with "SACI"-100 and 100A concentrates are stated to produce films which are soft, oily and self-healing. Salt fog tests on "SACI"-100 and 100A show 500 hours to failure for "SACI"-100; 600 hours to failure for "SACI"-100A with a dry film thickness of 0.5 mil; 1000 hours to failure for "SACI"-100 and 1200 hours to failure for "SACI"-100A with a dry film thickness of 1.0 mil.

"SACI"-200 and 200A are^' colloidal dispersions of said complex in a paraffinic mineral oil. "SACI"-200A contains 36 wt.% of said complex and 64 wt.% mineral oil. "SACI"-200A also contains oxidized petrolatum. The other statements made as to "SACI"-100 and 100A are applicable to "SACI"-200 and 200A.

"SACI"-300.is a colloidal dispersion of a thixotropic overbased inorganic-organic complex in mineral spirits containing about 35 wt.% of said complex and about 37 wt.% of said mineral spirits, with minor proportions of a microcrystalline wax and a paraffinic mineral oil to provide corrosion-inhibiting compositions which are stated to have exceptional protection properties in salt water immersion and salt atmospheres; that typical applications include outdoor parts storage, automobile body rust protection, coatings for underground pipe, marine applications and protection of overseas shipments; that "SACI" 300 wax-like coatings can be used in organic solvent dilutions or in combination with asphalts or petrolatums where long-term protection and relative ease of removal are important; and that the films resulting from using the basic formulation of SACI are firm and waxy. "SACI"-300A is similar to "SACI"-300; but it also contains oxidized petrolatum. Salt fog tests on "SACI"-300 and "SACI"-300A show, among other thicknesses of dry films, 300+ hours to failure for "SACI"-300 with a 0.5 mil dry film thickness and 800+ hours to failure with "SACI"-300A with the same film thickness; and, where the film thickness is 1.0 mil, 800+ hours to failure for "SACI"-300 and 1500+ hours to failure for "SACI"-300A. With films of 5.0 mil thickness, "SACI"-300 showed failure after 2000+ hours, and "SACI"-300A showed failure at 3000+ hours.

Other commercial "SACI" products are, as noted above, "SACI"-2400, "SACI"-2452 and "SACI"-2460. These "SACI" products are all corrosion-preventive concentrates in the form of mineral spirits-wax colloidal dispersions. They are stated to have a high content of the thixotropic inorganic-organic complex (65 wt.% solids in "SACI"-2400, 52 wt.% in "SACI"-2452, and 60 wt.% in "SACI"-2460) . They are stated to be formulatable with both refined and unrefined waxes, petrolatums and oxidized petrolatums, resins, polymers, asphalts, oils, and aliphatic and aromatic solvents to achieve virtually any solids, activity and/or viscosity level desired. Salt fog data are presented utilizing dry film thicknesses of 0.5 mil and 1.0 mil, hours to failure with 0.5 mil being 500, and hours to failure with.1.0 mil_being 1100.

"SACI"-700 is a colloidal dispersion of said complex in mineral spirits, the non-volatile solids content of which, namely, the thixotropic overbased complex (TBN is 250), is substantially 50 wt.%, and the mineral spirits content of which is substantially 50 wt.%. It is stated in "SACI"-700 Technical Data sheets that the "SACI"-700 must be used with an added plasticizer or resin for effective protection; and, generally, that "SACI"-700 can be formulated with hydrocarbon resins, asphalts, waxes, mastics, petrolatums and oils to produce a variety of effective coatings. Also shown are the results of salt spray and humidity cabinet corrosion tests.

"SACI"-760 is a colloidal dispersion in mineral spirits of a thixotropic overbased calcium organic sulfonate complexed with calcium carbonate (TBN is 265), the non-volatile solids content of which, namely, the thixotropic overbased complex, is substantially 60 wt.%, and the mineral spirits content of which is substantially 40 wt.%. The organic portion of said organic sulfonate is derived from a linear alkylbenzene sulfonic acid.

Generally speaking, the various "SACI" products are stated to be capable of being formulated with one or more of refined and unrefined waxes, petrolatums, resins, polymers, asphalts, oils, and aliphatic and aromatic solvents to achieve various levels of solids, activity, and/or viscosity.

Summary of the Invention

Our present invention is based upon discoveries that novel improved corrosion-inhibiting coating compositions can be obtained which are characterized by a combination of particular properties and which have enhanced utilities over various of the corrosion-inhibiting coating compositions which have heretofore been known to the art.

The corrosion-inhibiting compositions of our present invention (hereafter, for convenience, sometimes called "compositions" or "coating compositions") are in the form of free-flowing liquids which are capable of being applied as thin films on the surfaces of metal substrates which are to be protected against corrosion or rusting, and contain, as essential ingredients, (a) inorganic-organic complexes in the form of thixotropic overbased alkaline earth metal, particularly calcium, organic sulfonates completed with alkaline earth metal, particularly calcium,- carbonates; (b) synthetic drying oils particularly per se, or mixtures of synthetic drying oils with drying oils, in which latter case it is especially advantageous that such mixtures contain substantially predominating proportions or amounts of the synthetic drying oils over the proportions or amounts of the drying oils; (c) driers, commonly and desirably of the type of paint driers; and (d) volatile organic solvents, particularly volatile hydrocarbon solvents; the aforesaid (a), (b) and (σ) ingredients being dissolved and/or colloidally dispersed in said (d) solvent to provide free-flowing homogeneous compositions which may be deposited on the metal substrate by the usual coating procedures, for example, by brushing, but more desirably by spray-drying.

The novel and improved corrosion-inhibiting compositions of our ** present invention are generally characterized by the following properties: These include the production, on drying and/or curing, at room temperatures or ambient temperatures, of thin liquid films of said compositions, for instance, from about 0.5 to 6 mils, or even appreciably greater, but preferably about 1 to about 3.5 mils, in a drying and/or curing time of about 1 to about 6 hours, particularly about 1 to 2 hours; the dry and/or cured films are characterized by being firm or hard, but generally not brittle, and are non-oily or essentially non-oily and free or essentially free of tack to the human touch* they have a strong adherence to the metal substrate and possess a permanence so as not to be readily removable or stripped off from the metal substrate by means of unheated usual degreasing solvents; and, generally speaking, are removable by other means only with substantial difficulty in those instances where removability may be sought without damaging the underlying surfaces of the metal substrate. Advantageously, the foregoing combination of ingredients are used in conjunction with one, and particularly more than one, supplemental ingredient or ingredients which are described hereafter in detail. Detailed Description

We have disclosed above the combination of ingredients which we regard as being essential in the novel corrosion-inhibitor compositions of our present invention, and have stated that said ingredients are used in certain ranges of proportions. The said ranges of proportions are approximately as follows in terms of wt.%

of the corrosion-inhibiting compositions:

wt.%

(a) Inorganic-organic complex 20 to in the form of a thixotropic 50, overbased alkaline earth particularly metal organic sulfonate 15 to 30 complex with an alkaline earth metal carbonate¹

(b) Synthetic drying oil, or 15 to 60, mixture of synthetic particularly drying oil and drying 15 to 35, oil in which mixture synthetic drying the synthetic drying oil used oil largely solely; 15 to predominates over the 50 synthetic drying oil drying oil with a drying oil, said drying oil constituting up to about 40%, particularly about

20 to 40% of the synthetic drying oil

(c) Drier(s) 0.3 to 2

(d) Volatile organic 10 to 70% solvent particularly

15 to 55, better still

30 to 50

With regard to the (a) ingredient, various inorganic-organic complexes in the form of thixotropic overbased alkaline earth metal, particularly calcium, organic sulfonates complexed with alkaline earth metal.

1. Based on solids content. particularly calcium, carbonates, can be used in accordance with our invention. Such inorganic-organic complexes are, as is well-known, water-insoluble but are colloidally dispersible in volatile organic solvents, most commonly of hydrocarbon aliphatic or cycloaliphatic character. As previously noted, they are disclosed in the various patents referred to above. As has also been indicated above, the aforesaid complexes are most desirably derived from the use of branch chain or linear or straight chain monoalkylbenzene sulfonic acids or dialkylbenzene sulfonic acids, or mixtures of such sulfonic acids in which the dialkylbenzene sulfonic acids advantageously predominate, and the alkyl groups of which contain predominately from 12 to 30 carbon atoms, more particularly predominately from 12 to 22 carbon atoms. One of such well-known sources is the material commonly called "postdodecylbenzene" sulfonate, which is a sulfonic acid of a bottoms product from the manufacture of dodecylbenzene in which the alkyl groups are branch chain, and another is a sulfonic acid of a generally corresponding bottoms product but in which the alkyl groups are linear or straight chain and which bottoms are commonly known as "NAB" bottoms. These inorganic-organic complexes, in the case of the calcium compounds, are commonly characterized by the formula (RSO3)2Ca:CaCθ3, where R is an akylbenzene radical of the foregoing type. A broader formula is shown, for instance, in the aforementioned U.S. Patent No. 3,453,124, which discloses thixotropic alkaline earth metal organic sulfonate/alkaline earth metal carbonate complexes which are useful in the preparation of the corrosion-inhibiting compositions of our present invention. Those inorganic-organic complexes which are particularly useful in the practice of our invention have base numbers in the range of about 200 to 350; or, stated in terms of their metal ratios, they have metal ratios of at least 4.5, and particularly in the range of about 7 to about 12. Although any thixotropic overbased calcium sulfonate/calcium carbonate complex is acceptable or reasonably satisfactory in the production of the novel corrosion-inhibiting compositions of our present invention, particularly advantageous as a convenient commerce source of such cδmplexes is "SACI"-760. If it is desired to utilize as a starting material with a higher content of the complex, or a lower content of mineral spirits, for use in the preparation of corrosion-inhibiting compositions made in accordance with our present invention, all that need be done is to take a given weight of the "SACI"-760, and heat it, at say 225° F, to drive off the desired amount of the mineral spirits so as to provide a total solid products complex, or a complex having any desired wt.% of mineral spirits less than 40 wt.%.

With respect to the (b) ingredient, namely, the synthetic drying oil, or the mixture of the synthetic drying oil and the drying oil in which the synthetic drying oil largely predominates over the drying oil, we may point out, first, the following:

As used herein by us, the term "synthetic drying oil" is intended to mean materials which have good to excellent drying properties- at room temperatures or ambient temperatures and which, generally speaking, may be in the form of resins or resinous materials, and which comprise polymers or copolymers, illustrative examples of which are ethylenically-unsaturated polycarboxylic acid esters of aliphatic polyhydric alcohols, in which said polyhydric alcohols contain at least three hydroxyl groups and examples of which polyhydric alcohols are glycerine, trimethyol propane and pentaerythritol, and in which the polycarboxylic acids are preferably phthalic acid or phthalic anhydride, or maleic acid or maleic anhydride, and with ethylenically-unsaturated oils such as linseed oils or similar drying oils or the long oil fatty acids thereof, such as linseed oil fatty acids or tall oil fatty acids (TOFA) . These include long oil alkyds or oil-modified alkyd resins, and phenolic-modified alkyds. The hydroxyl values of such alkyds are variable, those having hydroxyl values in the range of about 60 to about 125 being particularly preferred. The term "synthetic drying oils" also includes resins or resinous materials, having good to excellent relatively fast drying properties at room temperatures or ambient temperatures, which are chemically structurally modifications of the alkyd resins or are chemically structurally different from the long oil alkyd resins. Modified alkyd resins which have good to excellent drying properties include acrylic and vinyl modified alkyds. Alkyd resin or resinous driers can also be modified by a post addition of phenolics, acrylics and vinyls in which the drying characteristics of the starting alkyds are varied, but, so long as the thus-modified alkyds have good to excellent drying properties reasonably akin to those of the long oil alkyds, their use is within the scope of our invention. Other resin or resinous materials which have good to excellent drying properties include certain epoxy esters and certain polybutadienes. Some of these resins, although possessing drying properties, may not be commercially useful because of adverse effects or costs as, for example, polybutadienes which, because of certain physical properties thereof, cannot be used in the proportions required for use in accordance with our invention, although they can be used in small proportions, for instance, of the order of 1 to 2 or 3%, to obtain special effects in conjunction, for example, with long oil alkyds where the latter are used in proportions of at least 15 wt.% of the corrosion-inhibiting compositions. At least some of the aforesaid resins or resinous materials which have good to excellent drying properties which, on oxidation, serve to form or produce hard, non-tacky, essentially non-oily films, are commonly referred to as convertible resins or binders. Others fall into the category of thermoplastic resins of the type which form such films through volatile solvent evaporation. Such thermoplastic resins, which may be of the type of acrylic, vinyl and hydrocarbon resins, when admixed with convertible resins, improve drying and/or curing times, film hardness, and resistance to organic solvents and various chemicals. No novelty is claimed by us per se in synthetic drying oils. In those instances where post-modified alkyds are utilized, they are generally employed as a minor part of the convertible resins, such as the long oil alkyds, and a minor part of the corrosion- inhibiting compositions, such post-modified alkyds constituting from about 2 to 15 wt.%, preferably about 2 to about 6 wt.%, of the corrosion-inhibiting compositions.

Synthetic drying oils are sold under various trademarks illustrative of which are "BECKOSOL" (Reichhold Chemical Company); "AROPLAZ", for example, "AROPLAZ 1266-M-60, 1266-M-70 and 1271 (Ashland Chemical Company); epoxy ester resins such as those sold under the trademarks "EPOTUF", preferably "EPOTUF" No. 37- 004, and "UROTUF" (Reichhold Chemical Company); and certain of the "RICON" resins, preferably "RICON" 100 and/or 156 (Colorado Chemical Specialties, Inc.).

As used herein by us, the term "drying oils", which per se are well-known to the art, is intended to mean natural drying oils which have good to excellent drying properties at room temperatures or ambient temperatures which, generally speaking, comprise ethylenically-unsaturated triglycerides of. higher fatty or other ethylenically-unsaturated monocarboxylic acids, illustrative of which are linseed oil, soya bean oil, dehydrated castor oil, tung oil, walnut oil, oiticica oil, safflower oil and fish oils, as well as such modified oils exemplified by oxygenated drying oils such as, for instance, oxygenated or blown or heat-bodied or polymerized or isomerized oils of the foregoing natural drying oils. In place of glycerin, other aliphatic polyhydric alcohols containing at least 3, generally from 3 to 6, hydroxyl groups can be reacted with higher molecular weight ethylenically-unsaturated monocarboxylic acids containing mainly from 16 to 22 carbon atoms to produce said drying oils. Generally speaking, the preferred drying oils, which are used in conjunction or together with the synthetic drying oils, are raw linseed oil or bodied linseed oils per se, as they are and long have been known to the art.

With respect to the (c) ingredient, namely, the driers, they are well-known to the art and are commonly used in various types of compositions, including corrosion-inhibiting compositions in which synthetic drying oils, or drying oils, are utilized. The driers which are utilized in the corrosion-inhibiting compositions of our invention can be and • desirably are driers which, typically, are of the paint drier type. They are, generally speaking, polyvalent, usually divalent, metal salts of soap-forming carboxylic acids. Illustrative examples of such driers are naphthenates, tallates, and octoates of such metals as cobalt, zirconium, lead, nickel, zinc, chromium and manganese, or mixtures of two or more of such driers. We prefer to use mixtures of cobalt naphthenates and zirconium octoates.. The drier is used in distinctly small proportions, generally in the range of about 0.3 to about 2 wt.% of the corrosion-inhibiting composition, the amount depending, in part, on the wt.% of the synthetic drying oil, or the above-described mixtures of synthetic drying oils and drying oils, used in any of the corrosion-inhibiting compositions of our present invention. We prefer to use mixtures of cobalt naphthenate and zirconium octoate in a wt. ratio of about 1:13.3.

With respect to the (d) ingredient, that is, the volatile organic solvent, such solvents can be of aliphatic, cycloaliphatic or aromatic character, and include hydrocarbons, chlorinated hydrocarbons, alcohols, ketones and ethers which are compatible in the .system. Preferred volatile organic solvents are aliphatic solvents, especially suitable being odorless mineral spirits because of its low toxicity and relatively low cost as well as its advantageous flash point; and, also, VM&P. Other volatile organic solvents which can be used are disclosed in the above-mentioned Patent No. 3,453,124, in Column 3, the disσlosure of which volatile solvents is herein incorporated by reference.

We come, now, to a consideration of supplemental ingredients one or more than one of which can be used in producing corrosion-inhibiting compositions of our invention for obtaining particular effects or imparting certain properties to corrosion-inhibiting compositions. In general, each of the following ingredients has been used heretofore in particular corrosion-inhibiting compositions known to the art of the type which utilize as one of the ingredients thereof the inorganic-organic complexes described in the aforementioned prior art patents and Technical Data sheets.

Petrolatums and/or oxidized petrolatums, and, also, microcrystalline waxes, crude and refined, can be used in the corrosion-inhibiting compositions of our invention. They are, as indicated above, per se, well-known to the art and are articles of commerce. Illustrative of the oxidized petrolatums are those sold by ALOX Corporation under ALOX Nos. 100D, 102, 600 and 601. Those oxidized petrolatums where the extent of oxidation is such as to provide acid numbers in the range of about 10 to 130 are most suitable for the purposes of our present invention-, particularly oxidized petrolatums having acid numbers in the range of 15 to 60. The product sold under the trademark "SOCCO-R-H-15" (Metal Lubricants Co., Harvey, Illinois) is illustrative of a synthetic oxidized petrolatum which is used and sold for use in formulations of rust preventatives and is blended with metal or synthetic sulfonates to produce corrosion inhibitors.

The petrolatums, the oxidized petrolatums, and the microcrystalline wax act, in certain respects, generally as self-healers, they serve to inhibit or prevent overcuring and embrittlement of the coatings, and they also function to lower water-sensitivity. Where utilized, they may be employed in variable minor proportions, generally in the range of about 2 to about 6 wt.% of. the corrosion-inhibiting compositions of our invention.

The epoxidized oils which may be used in the corrosion-inhibiting compositions made in accordance with our invention are, per se, well-known to the art. When used, they serve to promote compatibility and to improve flexibility of the coatings on metals and, also, to enhance the adhesion of the coatings to the metal surfaces. They have little effect on salt fog performances. Illustrative epoxidized oils are those prepared by the epoxidation of triglyceride oils, particularly, drying oils of natural or synthetic character, among which are tung oil, dehydrated castor oil, corn oil, cottonseed oil, soya bean oil, walnut oil, and fish oils. Particularly satisfactory is epoxidized linseed oil, exemplified by the product sold under the trademark "DRAPEX" (Argus Chemical Corporation), in which the epoxide equivalent is 10.4. It is preferred to use epoxidized oils which have high oxirane contents. They may be utilized in distinctly minor proportions, generally from about 2 to 6 wt.% of our corrosion-inhibiting compositions. Non-drying oil type resins and. certain waxes can also be incorporated into the corrosion-inhibiting compositions of our invention, and they can be of otherwise diversified types. Those which fall into this category are hard resins and hard waxes which are water-insoluble and soluble or colloidally-dispersible in volatile organic solvents. They include, by way of illustration, hydrocarbon resins (petroleum and non-petroleum), unmodified or modified, and sold under such trademarks as "PICCOPALE" (Hercules, Inc.), "BETAPRENE" (Reichhold Chemical Company); and thermoplastic resins of various types such as acrylic resins and some of which are sold under the trademark "ACRYLOID"-acrylic resins (Rohm & Haas Co.); and vinyl resins such as those sold under the trademark "GEON" (B.F. Goodrich Chemical). Illustrative hard waxes are polyethylene waxes, carnauba wax and montan waxes as well as certain synthetic waxes. To the extent such resins or waxes are used, the proportions thereof are somewhat variable, but it is preferred that they do not be used in amounts exceeding 5 wt.%, generally from about 1 to about 3%, of our corrosion-inhibiting compositions. To the extent that the corrosion-inhibitor coated metal surfaces are used in an environment to which they are subjected to exposure to ultraviolet rays, and resultingly to ultraviolet degradation, known agents which prevent or inhibit ultraviolet degradation can be included in appropriate amounts or proportions in corrosion-inhibiting compositions of our invention. An illustrative ultraviolet absorber, useful in corrosion-inhibiting compositions made in accordance with our present invention, particularly where exposure to outdoor sunlight is involved and the coatings are clear, is the product sold under the trademark "TINUVIN" (Ciba-Geigy Corporation). Its use is generally in proportions of less than 1 wt.% of the corrosion-inhibiting compositions.

Pigments represent another of the optional ingredients of the corrosion-inhibiting compositions of our invention. Generally, they have the property of enhancing to a substantial extent the ability of the corrosion-inhibiting coatings produced by the compositions of our invention to withstand any adverse effects of ultraviolet rays which may be encountered in outdoor exposure environments. Illustrative examples of such pigments are titanium dioxide, zinc oxide, iron oxides, carbon black, lamp black, Moly Orange; and organic dyes such as Phthalo Greens, Phthalo Blues, and organic reds and yellows. If used in our corrosion-inhibiting compositions, the proportions thereof may range ^* from a fraction of 1 to about 18 wt.% of our i. compositions.

Extenders also are optional ingredients in the corrosion-inhibiting compositions of our invention. They are generally similar in the functions which they perform in our corrosion-inhibiting compositions to the pigments except that certain of said extenders do not impart any color or impart only relatively little color to our compositions. They tend to have a favorable effect in salt fog and QUV test results, reducing film drying time, enhancing film hardness, and increasing resistance to ultraviolet rays. Illustrative examples of extenders are clays, talcs, calcium carbonates, mica, and silicas. If used, the proportions thereof are variable but may conveniently range, for instance, up to about 35 wt.% of our corrosion-inhibiting compositions.

Polybutenes can be used in the corrosion-inhibiting compositions of our invention. If used, they serve to improve compatibility, play a favorable role in preventing or reducing any tendency of embrittlement in the coating, and they also enhance adhesion of the cured films to the metal substrate. If used, the proportions thereof are variable, but may conveniently range, for instance, from 2 to about 6 wt.% of our corrosion-inhibiting compositions.

Still another of the optional ingredients which can be incorporated into the corrosion-inhibiting compositions of our present invention are plasticizers, generally of the type which are used in paint compositions. They have the properties of tending to reduce embrittlement of the films or coatings produced by the compositions of our invention. Illustrative examples of such plasticizers are phthalate esters, for example, dioctyl phthalate; trimellitates, for instance, trioctyltrimellitate; and adipates, for instance, dioctyl adipate. If used, the proportions thereof may range up to about 12 wt.%, generally from about 2 to 5 wt.% of our corrosion-inhibiting compositions.

It is also generally desirable, in particular situations, to include in our compositions anti-skinning agents, particularly suitable being that sold under the trade designation "Exskin II" (Methyl Ethyl*Ketoxime) which is used in very minor proportions, generally well less than^'l wt.%, usually about 0.3 to 0.4 wt.%.

It is particularly desirable that the corrosion-inhibiting compositions of our present invention do not contain any mineral oils, paraffinic or naphthenic. Small proportions may be used, but not in sufficient amounts to adversely affect the hard, non-tacky, essentially non-oily coatings produced in the use of the corrosion-inhibiting compositions of our present invention. If used, the proportions, based on the weight of our corrosion-inhibiting compositions, are distinctly minor, generally in the range of about 1 to about 3%. They serve to prevent or reduce possible over-curing or embrittlement of the coatings and may have other minor effects in other regards, as, for instance, the ability to bleed out of a cured film and prevent or inhibit corrosion in a damaged area, enhance or increase ^'rust prevention by lowering water-sensitivity, and increasing metal-wetting properties of the coatings. As we have noted above, in the novel compositions of our. invention, the use of mineral oils is unnecessary, with due regard for the properties which they possess, and, indeed, the necessity therefor in very high proportions in various prior art corrosion-inhibiting compositions to achieve operative effectiveness.

The following EXAMPLES of corrosion-inhibiting coating compositions made in accordance with the present invention are given by way of illustration only and not by way of limitation as numerous other compositions can readily be prepared in light of the teachings and guiding principles disclosed above. (Also included with said EXAMPLES are Ranges of Wt.% modifications of said EXAMPLES without any material changes in the properties and utilities of said illustrative EXAMPLES proper). All parts listed are by wt.% of said compositions. They include preferred embodiments of the invention. We consider EXAMPLES 1 and 5 as constituting, generally, the best embodiments of our invention for use as pipe varnish compositions, although they have many other areas of usage as highly effective corrosion-inhibiting compositions. We consider EXAMPLE 2 as the best embodiment of our invention for overall use, in a variety of environments such as automotive maintenance, industrial and, also, various non-automotive environments such as on bridges, where fast-drying, hard, non-tacky, essentially non-oily highly-permanent coatings are an important desideratum; as well as effective corrosion resistance in aggressive salt environments, where the corrosion-inhibiting compositions of our invention are applied to somewhat rusted or poorly-prepared metal substrate surfaces, primarily but not limited to different grades of carbon steel. Our corrosion-inhibiting compositions also allow, in many instances, for good film build and application even on the bottom side of horizontal surfaces without any appreciable dripping or loss of.the applied liquid coating prior to at least partial drying and/or curing occurring.

It is to be understood that compositions which function best in certain environments may not, though reasonably or highly effective, necessarily be the best embodiments when used in other environments. Overall, what has been set forth above as being considered the best embodiments of our invention is, generally speaking, correct. All of said compositions are, however, highly advantageous in various environments or for various corrosion-inhibiting uses.

In the following EXAMPLES, "SACI"-760 is used as the source of the inorganic-organic complex, in this case the thixotropic overbased calcium sulfonate/calcium carbonate complex which, as has been noted above, contains 60 wt.% of said non-volatile (N.V.) complex and 40 wt.% of mineral spirits, it also being pointed out that the TBN of the complex is approximately 265. It can readily be determined by simple arithmetic what the wt.% is of the said inorganic-organic complex present in the corrosion-inhibiting coating compositions of said EXAMPLES, and the total amount of the mineral spirits present in said coating compositions by adding together the mineral spirits shown as a separate ingredient and that contributed by the "SACI"-760. As has previously been indicated, separately-prepared thixotropic inorganic-organic complexes free or essentially free of organic solvents can be used as the complex ingredient of the corrosion-inhibiting compositions of our present invention, but it is distinctly more convenient to use commercial products, such as certain of the "SACI" products, particularly "SACI"-760^'or "SACI"-700, as the source of said complexes.

The situation is similar, for instance, in the case of other ingredients which are employed in the preparation of the corrosion-inhibiting compositions of our present invention, as, for instance, using synthetic drying oils as they are commercially produced and sold in the form, e.g. of solutions in organic solvents, or pigments in the form of pastes, in arriving at the predetermined particular proportions of the ingredients desired in various of the corrosion-inhibiting compositions of our present invention. Generally speaking, the synthetic drying oils and such metal pigments as the aluminum pigment pastes are commercially marketed in the form of admixtures with volatile organic solvents such as mineral spirits. The aluminum pigment pastes, for instance, are commonly marketed in such admixtures with 70 N.V.

The order of the mixing or blending of the ingredients is not critical, any convenient orders of addition being generally satisfactory. When, in the preparation of the corrosion-inhibiting compositions of our invention, stripping of volatile organic solvent is desired to be carried out, blending order is in order only to exclude the drier(s), and epoxidized oils if used in the compositions; and, after the stripping, then to add the drier(s) and the epoxidized oil. The heat reached during stripping would cause or tend to cause gelling if the driers and/or the epoxidized oil were present in the composition when the stripping step was carried out.

EXAMPLE 1

(Wt.% Range)

Thixotropic Overbased Calcium Sulfonate/Calcium Carbonate Complex (60 N.V.) ("SACI"-760) 33.9 32 -34

Long Oil Alkyd (70 N.V.) 26.74 28 -32

Phenolic Modified Alkyd (50 N.V. ) 2.89 2-4

Crude Microcrystalline Wax 4.08 2-6

Mineral Spirits 31.08 28 -32

Paint Driers 0.7 0 . 3-1

Anti-Skinning Agent 0.61 0 . 3- •0 . 8

Performance: QUV - 330 hours Salt Fog: 1 ml DFT* - 900 hours Scribe: 1.5 mil DFT* - 500 hours - 1mm undercutting

Film: Hard; set to touch 1 hour

* (Dry film thickness) EXAMPLE 2

(Wt.% Range)

Thixotropic

Overbased Calcium

Sulfonate/Calcium

Carbonate Complex

(60 N.V.) ("SACI"-760) 50.35 48-54

Long Oil Alkyd (70 N.V.) 27.32 25-30

Boiled Linseed Oil 10.07 8-12

Crude Microcrystalline Wax 5.46 4-6

Polybutene 5.46 4-6

Paint Driers 0.9 0.6-1.2

Anti-Skinning Agent 0.44 0.3-0.6

Performance: QUV - 420 hours average

Salt Fog: 0.5 ml DFT* - 700 hours; 1.0 mil

DFT* - 950 hours Scribe: 3.5 mil DFT* - 500 hours - 1mm undercutting Dry Time: 4 hours

* (Dry film thickness)

EXAMPLE 3

(Wt.% Range)

Thixotropic Overbased Calcium Sulfonate/Calσium Carbonate Complex (60 N.V.) ("SACI"-760) 41.8 40-43

Long Oil Alkyd (70 N.V.) 22.63 ^' 20-25

Boiled Linseed Oil 8.5 7.5-10

Crude Microcrystalline Wax 4.3 4-6

Polybutene 4.3 4-6

Powdered Iron Oxide Pigment 17.75 15-20

Paint Driers 0.37 0.3-0.5

Anti-Skinning Agent 0.35 0.3-0.5

Performance:

Corrosion tests have been running for approximately 1000 hours without showing corrosion and said tests are continuing. EXAMPLE 4

(Wt . % Range )

Thixotropic Overbased Calcium Sulfonate/Calσium Ca'rbonate Complex (60 N.V.) ("SACI"-760) 47.0 45-50

Long Oil Alkyd (70 N.V.) 25.5 24-27

Boiled Linseed Oil 9.4 8-10

Crude Microcrystalline Wax 5.1 4-6

Polybutene 5.2 4-6

Aluminum Pigment Paste (70 N.V.) 6.6 6-8

Paint Driers 0.8 0.5-1

Anti-Skinning Agent 0.4 0.3-0.5

Performance: QUV - 4,000 hours, no rust Salt Fog: 1.0 ml DFT* - 1,296 hours Scribe: 3.5 mil DFT* - 500 hours - 1mm undercutting Film: Hard; to touch 1 hour

* (Dry film thickness) EXAMPLE 5

(Wt . % Range )

Thixotropic Overbased Calcium Sulfonate/Calcium Carbonate Complex (60 N.V.) ("SACI"-760) 32.72 30-35

Long Oil Alkyd (70 N.V.) 25.9 24-27

Phenolic Modified Alkyd (50 N.V.) 2.8 2-3.2

Crude Microcrystalline Wax 4.0 2-6

Polybutadiene

("RICON" 104 and/or 156) 1.8 1.5-2.5

Varsol 31.5 28-32

Carbon Black 0.25 0.2-0.35

Paint Driers 0.68 0.5-0.75

Anti-Skinning Agent 0.35 0.3-0.4

Performance: ^• QUV - 330 hours Salt Fog: 1 ml DFT* - 720 hours Scribe: 1.5 mil DFT* - 500 hours - 1-2 mm undercutting

* (Dry film thickness) EXAMPLB 6

(Wt . % Range )

Thixotropic Overbased Calcium Sulfonate/Calcium Carbonate Complex (60 N.V.) ("SACI"-760) 27.9 25-30

Epoxy Ester (60 N.V. ) (37-004) 20.9 18-22

Boiled Linseed Oil 7.0 6-8

Talc (Extender) 27.9 26-30

Crude Microcrystalline Wax 2.8 2-4

Mineral Spirits 10.3 .9-12

Epoxidized Linseed Oil 2.8 2-3.2

Paint Driers 0.4 0.3-0.6

Performance: QUV - 665 hours

Salt Fog: 1.0 ml DFT* - 450 hours

Dry time: about 1/2 hour

Hardness: very hard

* (Dry film thickness)

In said Performance Tests reported, the Salt Fog salt tests were run according to ASTM B-117 but using Q-panels coated with the specified dry film mil thickness of said compositions. Some coated panels were scribed down the center of the panel and were run for 500 hours in a Harshaw spray apparatus containing 5% salt solution. Failure is defined when more than 3 mm creep by rust from the scribe line occurs.

Generally speaking, in at least most instances, corrosion-inhibiting compositions, and/or films produced by the use of such compositions on metal substrates, made in accordance with our present invention have definitely improved properties or advantages, or various combinations of improved properties or advantages, in relation to one or more of at least the following considerations set forth below, over corrosion-inhibiting compositions and/or films utilizing overbased thixotropic inorganic-organic complexes as one of the ingredients of said compositions but where such compositions do not contain synthetic drying oils or natural drying oils and driers, as well as over corrosion-inhibiting compositions and/or films utilizing as one of the ingredients thereof overbased thixotropic inorganic-organic complexes, which compositions also contain drying oils, synthetic or natural, as shown in the above-cited Patent No. 3,925,087, or which contain drying oils, as shown in the above-cited Patent No. 4,495,225: corrosion resistance, as evidenced by salt spray and salt fog testing procedures, or accelerated weathering (i.e., QUV); film hardness; abrasion resistance; adhesion of the film to the metal substrate surfaces; and generally higher extent of permanence. It is recognized, and expressly shown by many of the corrosion-inhibiting compositions disclosed in the above-cited prior art, that numbers of or most of the aforementioned supplemental ingredients specifically mentioned have heretofore been used in various corrosion-inhibiting compositions, including corrosion-inhibiting compositions of the type which contain inorganic-organic complexes in the form of thixotropic overbased alkaline earth metal organic sulfonates complexed with alkaline earth metal carbonates, as well as those which also contain drying oils (Patent No. 4,495,225) or drying oils or synthetic drying oils (Patent No. 3,925,087). We do not; therefore, claim any patentable novelty broadly in the aspect of the use of such known supplemental ingredients in corrosion-inhibiting compositions within the scope of their use and utility in the corrosion-inhibiting compositions in which the prior art shows their usage, which prior art compositions do not disclose our new and improved corrosion-inhibiting compositions, independently of the matter of the inclusion therein of said supplemental ingredients.

As we have noted above, corrosion-inhibiting compositions of our invention have a wide range of uses in environments in which their properties are such that they overcome problems which various prior art and prior-known corrosion-inhibiting compositions have not been adequately satisfactory. Thus, for instance, a number of particular problems which has long plagued the steel pipe industries which has centered around seeking satisfactory or even reasonably satisfactory so-called pipe varnish compositions for steel pipe during storage under atmospheric or weather conditions or the like. Even today, in large steel-producing plants which, among other things, produce steel pipe, so-called varnish compositions which are commercially used are commonly characterized, when applied to the steel pipe, by the usual spraying or otherwise coating of presently-used pipe varnish compositions, by sagging which results in an uneven film build. In illustrative instances, the application of the pipe varnish compositions produces a film thickness of as little as 0.5 mils at the top of the pipe while, at the bottom of the pipe, there is an overbuild of film thickness, as well as literal dripping, creating undesirable "housekeeping" problems. Moreover, due to the marginal corrosion protection properties of various presently-used pipe varnish compositions and the inconsistent and ^• non-uniform film build, high rejection rates after outdoor storage of the varnished or coated steel pipe are encountered, being not uncommonly in excess of 30% after 6 months of outdoor storage. Such deficiencies have caused the rejection of appreciable amounts of steel pipe after outdoor storage with consequent substantial economic loss.

Traditional pipe varnishes comprise or consist of low-cost, quick-drying alkyd resins cut back to about 50% solids with volatile organic solvents. Due to better solvency and a relatively fast evaporation rate, a solvent such as xylene is commonly used. This choice of such solvents creates an extreme fire hazard in plant operations as the flash point is generally in the range of 70-85° F. Such traditional pipe varnish compositions commonly have marginal corrosion resistance. They commonly give only 100-200 hours salt fog protection at 1 mil dry film thickness. The relatively low solids content gives traditional pipe varnish compositions bad film build and application characteristics. When spray applied to a hopefully consistent 2 mils film thickness, such pipe varnish compositions, as indicated above, display very bad film sag (running) on curved surfaces.

Many efforts have been made over a substantial period of time to solve the problems and to attempt to arrive at suitable, or at least reasonably suitable, pipe varnish compositions. Certain of such efforts have involved the utilization in admixture with hydrocarbon resins such as ESCOREZ (Exxon ^■Company) of known volatile organic solvent-based wax-modified rust or corrosion-inhibiting compositions of the type of thixotropic overbased calcium organic sulfonates complexed with calcium carbonate, and in certain cases in conjunction with one or more additional ingredients, particularly more than one, selected from the group of petrolatums; oxidized petrolatums; waxes such as slack wax, and crude or refined microcrystalline waxes (non-oxidized or oxidized); and the like. While the use of such proposed pipe varnish compositions brings about certain improvements in relation to producing films having appreciably reduced sagging problems and in various other respects, other deficiencies, such as, for instance, the extent of resistance to deterioration in relation to ultraviolet light (U.V.) and inadequacy of film hardness, and also cost factors, has resulted in a failure commercially satisfactorily to meet the problems.

Those of the corrosion-inhibitor compositions of our present invention which are of especial utility as pipe varnishes in steel mills are characterized by particularly effective corrosion resistance, water displacement, thixotropy, U.V. resistance and film hardness and effective short dry time of the films

We refer to copending Patent Application Serial No. 705,148, filed February 25, 1985; and copending Patent Application Serial No. 745,762, filed June 17, 1985, of which we are aware since one of us is one of the joint inventors in each of said Patent Applications which, in common with our present Application, are owned by the same Assignee. The inventions disclosed in each of said Patent Applications are concerned with corrosion-inhibiting compositions which are of the type which include, as constituents thereof, (a) an inorganic-organic complex in the form of a thixotropic overbased alkaline earth metal organic sulfonate complex with an alkaline earth metal carbonate, (b) a drying oil or a synthetic drying oil, and (σ) a drier, in certain proportions, with or without various other ingredients, which compositions, after application in the form of a thin film on a metal surface and drying and/or curing, form a hard, essentially non-oily coating. The corrosion-inhibiting compositions disclosed and claimed in said copending Applications constitute various definite improvements over corrosion-inhibiting compositions previously known to the art. The corrosion-inhibiting compositions disclosed and claimed in our present Application constitute further improvements not only over the prior art patents and publications discussed above but also constitute further improvements and provide additional advantages for various corrosion-inhibiting purposes over the corrosion-inhibiting compositions disclosed in said copending Applications.

As illustrative of the improvements of corrosion-inhibiting compositions made in accordance with our present invention over those disclosed in the aforementioned copending Applications, the following TABLE shows a comparison of the properties of the best embodiment of which we are aware for use as a pipe varnish composition disclosed more particularly in said copending Application Serial No. 745,762 with one of the two essentially equally best compositions of our present Application for use as a pipe varnish.

TABLE: PERFORMANCE COMPARISON OF FORMULAS

MRT Stands for MAGNAFLUX RETENTION TEST METHOD which is a method which actually measures the cracks and defects in an iron or steel member usually before coating and commonly after coating with a corrosion-inhibiting coating. The Magnaflux test is a test of the pipe itself. If free from cracks or similar defects, the Magnaflux particles should not adhere to the coating at the end of testing the steel pipe for defects. This Test Method is a

2. EXAMPLE 2 of copending Application Serial No. 745,762.

3. EXAMPLE 5 of our present Application. well-recognized and published test. It was carried out by us as follows:

1. Knife coat a Q panel with corrosion-inhibiting composition to dry r film thickness of 1.5 mils.

2. Allow panel to air dry 24 hours.

3. Dip panel into Magnaflux iron filings and shake off excess.

4. Brush lightly to remove any excess filings which are not tightly bound.

5. Evaluate arbitrarily of a scale of 0-5.

0 - complete release - no filings present.

1 - excellent - only slight trace remaining.

2 - marginal pass - some filings are noted.

3 - marginally poor - more filings left.

4 - poor - much of surface covered.

5 - very poor - area almost completely covered.

3-5 are fails.

It is apparent from the foregoing TABLE that the illustrative corrosion-inhibiting composition of EXAMPLE 5 of our present application is superior in numbers of respects to the best composition for use as a pipe varnish of which we are aware in numbers of the tests, notably in the Angle Face Rust test, the QUV test, and the MRT test.

Our present patent application is also clearly distinguished from the corrosion-inhibiting compositions which are disclosed and claimed in the aforementioned co-pending patent applications.

Claims

«. ~ C—L ~ —AI —M —S

1. A corrosion-inhibiting composition in the form of a liquid solution and/or a colloidal dispersion including the following ingredients in substantially the following proportions by wt.% of the composition:

(a) Inorganic-organic complex in the form of a thixotropic overbased alkaline earth metal organic sulfonate complexed with an alkaline earth metal carbonate 20 to 50

(b) Synthetic drying oil, or a mixture which includes a synthetic drying oil in conjunction with a drying oil and in which the synthetic drying oil is present in proportions substantially in excess of the proportions of the drying oil, and 15 to 60 synthetic drying oil used solely; or 15 to 50 synthetic drying oil with drying oil, said drying oil constituting up to about 40% of the synthetic drying oil

(c) Drier(s) 0.3 to 2

(d) Volatile organic solvent 10 to 70; said corrosion-inhibiting composition, after application in the form of a thin film on a ferrous or non-ferrous metal surface and drying and/or curing in a period of about 1 to about 6 hours at room temperatures or ambient temperatures, forming a hard, non-tacky, substantially non-oily coating which is essentially not removable by unheated organic solvents generally or, if otherwise removable, such removability is accomplished with substantial difficulty and potential damage to surfaces of the metal.

2. A composition according to Claim

1, in which the alkaline earth metal is calcium.

3. A composition according to Claim

2, in which the inorganic-organic complex is a calcium organic sulfonate complexed with calcium carbonate and in which the organic part is an alkylbenzene in which alkyl contains from 12 to 30 carbon atoms.

4. A composition according to Claim 2, in which the (b) synthetic drying oil comprises a long oil alkyd.

5. A composition according to Claim 2, in which the (a) ingredient constitutes from about 15 to about 30 wt.%.

6. A composition according to Claim 3, which includes from about 2 to about 6 wt.% microcrystalline wax.

7. A composition according to Claim 3, which includes from about 2 to about 6 wt.% polybutene.

8. A composition according to Claim

3, which includes about 2 to about 6 wt.% of a phenolic modified alkyd.

9. A composition according to Claim

4, in which the volatile organic solvent is a member of the group of mineral spirits and VM&P.

10. A corrosion-inhibiting composition in the form of a liquid solution and/or a colloidal dispersion including the following ingredients in substantially the following proportions by wt.% of the composition:

(a) Inorganic-organic complex in the form of a thixotropic overbased calcium organic sulfonate complexed with calcium carbonate, in which the organic part of said sulfonate is a mixture of monoalkyl- and dialkyl-benzenes in which alkyl contains predominately from 12 to 18 carbon atoms, said complex having a base number in the range of about 200 to about 350 15 to 30

(b) Long oil alkyd drying oil having a hydroxyl value in the range of about 60 to about 125, or a mixture which includes said long oil alkyd drying oil in . conjunction with a drying oil 15 to 35 said long oil alkyd used solely; or 15 to 50 said long oil alkyd with said drying oil, said drying oil constituting up to about 40% of the long oil alkyd ( c ) Drier ( s ) 0. 3 to 2

(d) Volatile hydrocarbon solvent 15 to 55;

said corrosion-inhibiting composition, after application in the form of a thin film on a ferrous or non-ferrous metal surface and drying and/or curing in a period of about 1 to about 6 hours at room temperatures or ambient temperatures, forming a hard, non-tacky, substantially non-oily coating which is essentially not removable by unheated organic solvents generally or, if otherwise rem'ovable, such removability is accomplished with substantial difficulty and potential damage to surfaces of the metal.

11. A composition according to. Claim 10, in which the long oil of said long oil alkyd resin drying oil is tall oil.

12. A composition according to Claim

10, in which said volatile hydrocarbon solvent is a member of the group of mineral spirits and VM&P.

13. A composition according to Claim

11, which includes from about 2 to about 6 wt.% icrocrystalline wax.

14. A composition according to Claim 10, in which the hereafter-stated ingredients are present in approximately the stated proportions:

(a) Ingredient 32 to 34%

(b) Long Oil alkyd resin drying oil 28. to 32%

(σ) Volatile hydrocarbon solvent is selected from group of mineral spirits and VM&P 28 to 32%

and in which said compositio includes 2 to 6% microcrystalline wax and 2 to 4% of a phenolic modified long oil alkyd resin drying oil.

15. A composition according to Claim 10, in which the hereafter-stated ingredients are present in approximately the stated proportions:

(a) Ingredient 47-52

(b) Long oil alkyd resin drying oil 25-30

(c) Volatile hydrocarbon solvent selected from the group of mineral spirits and VM&P 18-25

and in which said drying oil is boiled linseed oil and which constitutes 8 to 12%, and in which said composition includes 4 to 6% polybutene, and 4 to 6% of a miσrocrystalline wax.

16. A composition according to Claim 10, in which the hereafter-stated ingredients are present in approximately the stated proportions:

(a) Ingredient 38-43

(b) Long oil alkyd resin drying oil 20-25

(σ) Volatile hydrocarbon solvent selected from the group of mineral spirits and VM&P 15-20

and in which said drying oil is boiled linseed oil and which constitutes 7 to 10%, and in which said composition includes 4 to 6% polybutene, and 16 to 19% of an iron"oxide pigment.

17. A composition according to Claim 10, in which the hereafter-stated ingredients are present in approximately the stated proportions:

(a) Ingredient 45-50

(b) Long oil alkyd resin drying oil 22-28

(c) Volatile hydrocarbon solvent selected from the group of mineral spirits and VM&P 16-20

and in which said drying oil is boiled linseed oil and which constitutes 7 to 11%, and in which said composition includes 4 to 6% polybutene, 4 to 6% of a microcrystalline wax, and 5 to 8% of an aluminum pigment paste.

18. A composition according to Claim 10, in which the hereafter-stated ingredients are present in approximately the stated proportions:

(a) Ingredient 30-35

(b) Long oil alkyd resin drying oil 24-28

(σ) Volatile hydrocarbon solvent 40-45

and in which said composition includes 2 to 4% of a phenolic-modified long oil alkyd drying oil, 1 to 3% of a polybutadiene, 4 to 6% of a miσrocrystalline wax,, and 0.2 to 1% of carbon black.

19. A composition according to Claim 10, in which the hereafter-stated ingredients are present in approximately the stated proportions:

(a) Ingredient 25-30

(b) Epoxy ester drying oil 18-22

(σ) Volatile hydrocarbon solvent selected from the group of mineral spirits and VM&P 18-23

and in which said drying oil is boiled linseed oil and which constitutes 6 to 8%, and in which said composition includes 2 to 4% epoxidized linseed oil, and 2 to 4% of a microcrystalline wax. ♦

20. A method for inhibiting the

■ corrosion of a metal surface, which comprises depositing on said surface a film of the composition of Claim 1 and then drying said film.

21. A method for inhibiting the corrosion of a metal surface, which comprises depositing on said surface a film of the composition of Claim 10 and then drying said film.

22. A metal article which has been protected against corrosion by the deposit on the surface thereof of the composition of Claim 1, followed by drying of said composition.

23. A metal article which has been protected against corrosion by the deposit on the surface thereof of the composition of Claim 10, followed by drying of said composition.