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Publication numberUS3216956 A
Publication typeGrant
Publication dateNov 9, 1965
Filing dateFeb 21, 1962
Priority dateFeb 21, 1962
Publication numberUS 3216956 A, US 3216956A, US-A-3216956, US3216956 A, US3216956A
InventorsCraig Willis G
Original AssigneeLubrizol Corp
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Metal-free acylated organic phosphate complexes as corrosion inhibitors
US 3216956 A
Abstract  available in
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Description  (OCR text may contain errors)

United States Fatent O 3,216,956 METAL-FREE ACYLATED ORGANIC PHOSPHATE COlWPLEXES AS CDRROSION INHIBITORS Willis G. Craig, Willoughby, Ohio, assignor to The Lubrizol Corporation, Wicklilfe, Ohio, a corporation of Ohio N Drawing. Filed Feb. 21, 1962, Ser. No. 174,691 11 Claims. (Cl. 260-23) The present invention relates to novel, metal-free, acylated organic phosphate complexes and processes for their preparation. In a more particular sense, it relates to corrosion-inhibiting coating compositions for metals comprising the aforesaid complexes.

The corrosion of metal surfaces is of obvious economic significance in many industrial applications and, as a consequence, the inhibition of such corrosion is a matter of prime consideration. It is particularly significant to users of steel and other ferrous alloys. The corrosion of such ferrous metal alloys is largely a matter of rust formation, which in turn involves the overall conversion of the free metal to its oxide.

The theory which best explains such oxidation of ferrous metal surfaces postulates the essential presence of both water and oxygen. Even minute traces of moisture are sufiicient, according to this theory, to induce the dissolution of iron therein and the formation of ferrous hydroxide until the water becomes saturated with ferrous ions. The presence of oxygen causes oxidation of the resulting ferrous hydroxide to ferric hydroxide, which then settles out of solution and is ultimately converted to ferric oxide or rust.

The above sequence of reactions can be prevented, or at least in large measure inhibited, by relatively impermeable coatings which have the effect of excluding moisture and/or oxygen from contact with the ferrous metal surface. Such coatings are, of course, subject to abrasion and other forms of physical deformation and to the extent that these coatings are penetrated or otherwise harmed by such influences they become ineffective for the desired purpose. It is important that such coatings provide complete protection for all of the ferrous metal surface. If there is any portion of such a surface which is not so protected, regardless of hoW small the unprotected surface may be, the degree of protection afforded is considerably less than required. A satisfactory corrosion-inhibiting coating then must have the ability to resist weathering, abrasion, chalking or powdering, alligatoring, and undercutting so that a uniform and complete protective film is maintained upon the metal surface. Alligatoring and undercutting are terms commonly used in the protective coating art to describe, respectively, the shrinkage of a coating to form a discontinuous, broken surface having a pattern akin to that of alligator skin and the separation of a coating from the metal substrate in the area adjacent to a scratch or score. In some instances, undercutting may be so severe that most, if not all, of the coating separates from the metal substrate.

Various derivatives of acid esters of phosphoric or phosphorothioic acids have been investigated by workers engaged in the task of providing protective coatings for metal. In U.S. Patent 2,080,299, for example, Benning et al. proposed the treatment of ferrous metals with phosphate acid esters or their alkali metal and ammonium salts to prevent rusting. Somewhat similarly, Butler and Le Suer (US. Patents 2,861,907 and 2,820,723) find that salt-esters of complex phosphorothioic acids are effective in preventing or retarding the corrosion of metals.

Although such known derivatives of phosphoric and phosphorothioic acids have provided means for combatting the corrosion of metals, they have not been completely satisfactory because of certain inherent shortcomings. The simple salt-esters of phosphoric acid are read- 3 ,216,956 Patented Nov. 9, 1965 ily washed or abraded from a metallic surface and thus provide complete protection only in a favorable environment. The saltesters of phosphorothioic acids, on the other hand, have the disadvantage, under certain conditions, of developing an objectionable odor reminiscent of hydrogen sulfide, particularly when a film of such a salt-ester comes in contact with water or humid atmospheres.

A further disadvantage of these known derivatives of phosphoric and phosphorothioic acids is that they form oily or tacky coatings which are not susceptible to the subsequent application of top-coats of siccative organic coating compositions such as paint, varnish, lacquer, enamel, and the like. Thus, their use has been limited to metal articles such as bulk castings, metal fasteners, firearm parts, iron cables, etc., which do not require a hard-film protective coating.

It is, therefore, a principal object of the present invention to provide novel, acylated organic phosphate complexes and processes for their preparation.

Another object is to provide corrosion-inhibiting coating compositions for metals, especially ferrous metals, which compositions comprise acylated organic phosphate complexes.

A further object is to provide novel coating compositions for metals, which compositions are resistant to weathering, abrasion, chalking, alligatoring, and undercutting.

A still further object is to provide means for improving the corrosion-inhibiting characteristics of known, siccative, organic coating compositions.

These and other objects of the invention are achieved by providing an acylated organic phosphate complex prepared by the process which comprises the reaction of:

(A) One mole of a phosphorus-containing reagent se lected from the group consisting of phosphorus pentoxide and phosphoric acids.

(B) From about 0.2 to about 5 moles of a copolymer of allyl alcohol and a styrene,

(C) From about 0.5 to about 5 moles of an alkyl phenol,

and

(D) From about 0.5 to about 4 moles per mole of (B) employed of an unsaturated aliphatic carboxylic acid compound selected from the group consisting of high molecular weight unsaturated aliphatic carboxylic acids containing at least about 12 carbon atoms and esters of such acids,

at a temperature within the range from about 50 C. to about 300 C. for about 0.5 to about 30 hours.

The term strong acid number as used herein denotes the number of milligrams of potassium hydroxide required to neutralize one gram of solvent-free reaction mixture in the presence of an indicator such as bromphenol blue or methyl orange which changes color in the region of pH 4. Acid-base neutralizations or titrations conducted in this manner measure acidity due to acid phosphates, but do not measure acidity due to carboxylic acids.

Thin films of the acylated organic phosphate complexes of the present invention are remarkably effective in protecting metal surfaces, especially ferrous metal surfaces, against the ravages of corrosion. The complexes are also useful as ingredients in known, siccative, organic coating compositions such as paints, varnishes, lacquers, primers, synthetic resins, and enamels, to which compositions they impart enhanced corrosion-inhibiting characteristics. When used in this manner, a minor proportion, generally from about 0.1 to about 25 percent, of an acylated organic phosphate complex of this invention is blended with a major proportion, generally from about 99.9 to about percent, of a siccative organic coating composition.

3 REAGENT A As indicated earlier, the phosphorus-containing reagent A is selected from the group consisting of phosphorus pentoxide and phosphoric acids. For reasons of conven-ience, economy, and reactivity in the process of the invention, phosphorus pentoxide is generally preferred.

Where it is desired to employ phosphoric acids, any of the several available phosphoric acids such as polyphosphoric, orthophosphoric, metaphosphoric, or pyrophosphoric acid may be used either alone or in admixture as this reagent. It is also feasible to use mixtures of phosphorus pentoxide with one or more of these phosphoric acids. Phosphoric acid, if employed, will generally be the ordinary, commercial 85 percent or 100 percent orthophospho-ric acid, although more dilute acids containing at least about 25 percent H PO are also usable.

REAGENT B This reagent is a copolymer of to 90 mole-percent of allyl alcohol with 90 to 10 mole-percent of a styrene. Especially useful for the purposes of this invention are copolymers prepared from approximately equimolar amounts of the two monomers and having an average molecular weight within the range from about 500 to about 5,000.

A particular preference is expressed for a copolymer of approximately equimolar amounts of allyl alcohol and styrene having an average molecular weight of about 1,'l00l,l50. Such a copolymer is available commercially under the trade designation, Polyol X-450. Similar copolymers of lesser or greater average molecular weight are also available commercially such as Monsanto RI- 100, which has an average molecular weight of about 1,580.

The term a styrene as used herein refers to styrene or any of the various substituted styrenes such as halogen-substituted styrenes, hydrocarbon-substituted styrenes, alkoxy-styrenes, acyloxy-styrenes, nitro-styrenes, etc. Examples of such substituted styrenes include p-chloro styrene, p-ethylstyrene, o-phenylstyrene, p-methoxystyrene, m-nitrostyrene, alpha-methylstyrene, and the like. In most instances, however, it is preferred to use styrene itself by reason of its low cost, commercial availability, and excellence as a raw material in the preparation of reagent B.

REAGENT C This reagent may be either a mono-alkyl or a polyalkyl phenol. The alkyl groups may be of any size, ranging from methyl up to alkyl groups derived from olefin polymers having molecular weights as high as 50,000 or more. Preferably the alkyl phenol is a mono-alkyl phenol in which the alkyl group contains from one to about 30 carbon atoms, preferably at least about 4 carbon atoms. Typical examples of useful alkyl phenols include, e.g., ortho, meta, and para-cresols; ortho, meta, and paraethyl phenols; para-isopropyl phenols, para-tertiary butylphenol, ortho n-amylphenol, para-tertiary amylphenol, heptylphenol, diisobutylphenol, n-decylphenol, wax-alkyL ated alpha-naphthol, wax-alkylated phenol, and polyisobutene-substituted phenols in which the polyisobutene substituent contains from about 12 to about 76 carbon atoms. The alkyl phenol may also contain substituent groups such as, e.g., chloro, fluoro, nitro, alkoxy, sulfide, nitroso, etc. A particular preference is expressed for para-tertiary amylphenol, a compound which is available under the trade designation Pentaphen. Also useful are polyhydric phenols such as alkylated resorcinols, alkylated catechols, alkylated pyrogallols, and their substitution products.

REAGENT D Reagent D, the unsaturated aliphatic carboxylic acid compound, is a high molecular weight unsaturated aliphatic carboxylic acid containing at least 12 carbon atoms and/ or an ester thereof. Illustrative of materials useful as this reagent includes, for example, linoleic acid, linolenic acid, linseed oil, tung oil, tung oil acids, methyl linoleate, ethyl linolenate, chloroleic acid, phenyloleic acid, oleic acid, behenolic acid, palmitolic acid, ricinoleic acid, ricinstearolic acid, and mixtures of any of the foregoing.

Especially preferred are the unsaturated aliphatic carboxylic acids and/ or esters thereof which contain at least two carbon-to-carbon double bonds such as linoleic acid, linseed oil, and linolenic acid. A particular preference is expressed for linoleic acid and tung oil, both of which are readily available, staple articles of commerce. It is not necessary that the unsaturated acids and/or esters thereof be chemically pure materials. Crude linoleic acid obtained, for example, from the processing of tall oil has been found to be very suitable as reagent D herein.

The process for the formation of the acylated organic phosphate complex may be carried out in any one of several different ways such as, for example: (1) preparing a mixture of reagents A, B, C, and D and then heating such mixture at a temperature within the range from about 50 C. to about 300 C., preferably from 80160 C., for about 0.5 to about 30 hours; (2) heating reagent B, the copolymer of allyl alcohol and a styrene, with reagent D, the unsaturated aliphatic carboxylic acid compound, at a temperature within the range from about 50 C. to about 300 C., preferably 80200 C., to effect acylation of the copolymer and then adding reagents A and C and continuing the heating, the total reaction time from about 0.5 to about 30 hours; and (3) heating reagents A, B, and C, at a temperature within the range from about 50 C. to about 300 C., preferably 150 C., and then effecting the acylation of such intermediate product with reagent D, the unsaturated aliphatic carboxylic acid compound, at temperatures within the range from about 50 C. to about 300 C., preferably 200 C., the total reaction time being from about 0.5 to about 30 hours.

Generally it is most convenient to conduct the process of this invention in the presence of an inert, volatile solvent which serves to reduce the viscosity of the reaction mass. The solvent may remain in the final product, if desired, to facilitate its application to metal surfaces. Any of the solvents ordinarily employed in the paint and varnish industry may be used for the purpose such as, e.g., benzene, xylene, toluene, mesitylene, cyclohexane, methylcyclohexane, aromatic petroleum spirits, chlorobenzene, trichloroethylene, ethylene dichloride, dioxane, turpentine, diisopropyl ether, and the like. Mixtures of one or more of the foregoing may also be used. In some instances, however, it is preferred to conduct the process in the absence of the solvent and then, optionally, to dilute the acylated organic phosphate complex with the desired solvent or mixture of solvents prior to its application to a metal surface. This is generally the most advantageous and economical procedure in instances where the acylated organic phosphate complex is to be shipped to some distant point. It is also the preferred procedure in instances where the solvent employed in diluting the acylated organic phosphate complex is a solvent such as isobutyl alcohol or octyl alcohol which is chemically reactive with one or more of reagents A-D, inclusive.

The precise chemical composition of the acylated or ganic phosphate complex of this invention is not known. It is believed, however, that the phosphorus-containing reagent and the unsaturated aliphatic carboxylic acid compound phosphorylate and acylate the organic hydroxy compounds present to form, respectively, acid phosphate ester groups and carboxylic acid ester groups. Other reactants such as polymerization and/or etherification may also occur during the process and it is not intended that the theories and evidence presented herein be interpreted in any manner which would limit the scope of the invention, except as defined by the appended claims.

The following examples are presented to illustrate specific modes of carrying out the process of this invention.

All parts are by weight unless otherwise specified. The strong acid number is reported for the solvent-free acylated organic phosphate complex and is determined using bromphenol blue as the end point indicator.

Example 1 210 parts (0.75 mole) of lineoleic acid, 288 parts (0.25 mole) of Polyol X450, 283 parts of xylene solvent, and 4 parts of para toluenesulfonic acid catalyst are introduced into a reaction vessel and stirred thoroughly. The whole is then heated to about 143 C. and maintained at this temperature for 4 hours while water of esterification is removed by means of a side-arm water trap. The crude acylated Polyol X-450 thus obtained is washed with 500 parts of water to remove the esterification catalyst and then it is dried by azeotropic distillation, returning the xylene by means of a side-arm water trap.

949 parts (0.24 mole) of the acylated Polyol X450, 79 parts (0.48 mole) of Pentaphen, 36 parts (0.25 mole) of phosphorus pentoxide, and 115 parts of xylene solvent arev reacted at the reflux temperature (ca. 143 C.) for 6 hours.

The resulting 50 percent solution in xylene of the desired acylated organic phosphate complex shows the following analysis.

Percent phosphorus 1.28 Strong acid No. 49

Example 2 100 parts of the product of Example 1 is heated to 130 C./80 mm. Hg to remove the xylene solvent and then 27 parts of isooctyl alcohol is added. The resulting product is a 65 percent solution of the acylated organic phosphate complex in isooctyl alcohol.

Example 3 The experiment described in Example 1 is repeated, except that isobutyl alcohol is employed in lieu of isooctyl alcohol. The product is a 65 percent solution of the acylated organic phosphate complex in isobutyl alcohol.

Example 4 575 parts (0.5 mole) of Polyol X450, 468 parts (0.5 mole) of boiled linseed oil, 164 parts (1.0 mole) of Pentaphen, 71 parts (0.5 mole) of phosphorus pentoxide, and 1278 parts of xylene are placed in a flask and stirred vigorously. The whole is refluxed for 6 hours while water is removed by means of a side-arm water trap. The product, a 50 percent solution of the desired acylated organic phosphate complex in xylene, shows the following analysis.

Percent phosphorus 1.15 Strong acid No 42 Example 5 460 parts (0.4 mole) of Polyol X450 is acylated with 336 parts (1.2 moles) of linoleic acid in 775 parts of xylene solvent over a period of hours at the reflux temperature.

1451 parts (0.38 mole) of the above acylated Polyol X450, 125 parts (0.76 mole) of Pentaphen, 54 parts (0.38 mole) of phosphorus pentoxide, and 179 parts of xylene solvent are heated for 8 hours at the reflux temperature. The product, a 50 percent solution of the acylated organic phosphate complex in xylene solvent, shows the following analysis.

Percent phopsphorus 1.33 Strong acid No. 52

Example 6 575 parts (0.5 mole) of Polyol X450, 598 parts (2.0 moles) of methyl linoleate, 164 parts (1.0 mole) of Pentaphen, 71 parts (0.5 mole) of phosphorus pentoxide, and 1408 parts of xylene solvent are introduced into a 6 reaction vessel and stirred vigorously. The whole is then heated for 6 hours at the reflux temperature while water is removed by means of a side-arm water trap. The product, a 50 percent solution of the acylated organic phosphate complex in xylene solvent, shows the following analysis.

Percent phosphorus 0.99 Strong acid No. 36

Example 7 575 parts (0.5 mole) of Polyol X450, 431 parts (1.5 moles) of methyl linoleate, 164 parts (1.0 mole) of Pentaphen, 71 parts (0.5 mole) of phophorus pentoxide, and 1241 parts of xylene solvent are introduced into a reaction vessel and stirred vigorously. The whole is then heated for 6 hours at the reflux temperature and the water of reaction is removed by means of a side-arm water trap. The product, a 50 percent solution of the acylated organic phosphate complex in xylene solvent, shows hte following analysis.

Percent phosphorus 1.26 Strong acid No. 54

Example 8 575 parts (0.5 mole) of Polyol X450 is acylated with 140 parts (0.5 mole) of linoleic acid and 112 parts (0.5 mole) of tung oil acids in 800 parts of xylene solvent over a period of 8 hours at the reflux temperature. The water of esterification evolved is removed by means of a side-arm water trap.

1500 parts (0.75 mole) of the above acylated Polyol X450, 249 parts (1.52 moles) of Pentaphen, 107 parts (0.75 mole) of phosphorus pentoxide, and 356 parts of xylene are introduced into a reaction vessel and stirred vigorously. The whole is then heated for 6 hours at the reflux temperature. The resulting product, a 50 percent solution of the acylated organic phosphate complex in xylene, shows the following analysis.

Percent phosphorus 2.19 Strong acid No. 76

Example 9 575 parts (0.5 mole) of Polyol X450 is acylated with 420 parts (1.5 moles) of linoleic acid in 968 parts of xylene solvent containing 0.5 part of para toluenesulfonic acid as an esterification catalyst. The acylation is effected by heating the whole for a period of 12 hours at the reflux temperature while the water of esterification is removed by means of a side-arm water trap.

1271 parts (0.33 mole) of the above acylated Polyol X450, 492 parts (3.0 moles) of Pentaphen, 142 parts 1.0 mole) of phosphorus pentoxide, and 633 parts of xylene solvent are introduced into a reaction vessel and stirred vigorously. The whole is then heated at the reflux temperature for 6 hours to yield the product, a 50 percent solution of an acylated organic phosphate complex in xylene. It shows the following analysis.

Percent phosphorus 2.25 Strong acid No.

Example 10 522 parts (0.4 mole) of an acylated Polyol X450 prepared in the manner set forth in Example 9, 392 parts (2.4 moles) of Pentaphen, 114 parts (0.8 mole) of phosphorus pentoxide, and 506 parts of xylene solvent are stirred together for 6 hours at about 143 C. The product, a 50 percent solution of the acylated organic phosphate complex in xylene, shows the following analysis.

Percent phosphorus 3.01 Strong acid No. 112

7 Example 11 1042 parts (0.8 mole) of an acylated Polyol X-450 prepared in the manner set forth in Example 9, 197 parts (1.2 moles) of Pentaphen, 57 parts (0.4 mole) of phosphorus pentoxide, and 254 parts of xylene are introduced into a reaction vessel and stirred vigorously. The whole is heated for hours at the reflux temperature while water is removed by means of a side-arm water trap. The product, a 50 percent solution of the acylated organic phosphate complex in xylene, shows the following analysis.

Percent phosphorus 1.50 Strong acid No. 66

Example 12 750 parts (0.5 mole) of Polyol X-450 is acylated with 112 parts (0.5 mole) of tung oil acids in xylene solution (853 parts of xylene) over a period of 6 hours at the reflux temperature. The water of esterification is removed by means of a side-arm water trap.

1355 parts (0.5 mole) of this acylated Polyol X-450, 246 parts (1.5 moles) of Pentaphen, 71 parts (0.5 mole) of phosphorus pentoxide, and 317 parts of xylene solvent are introduced into a flask and stirred vigorously. The whole is stirred for 6 hours at the reflux temperature while water is removed by means of a side-arm water trap. The product, a 50 percent solution of the acylated organic phosphate complex in xylene, shows the following analysis.

Percent phosphorus 1.58 Strong acid No. 56

Example 13 460 parts (0.4 mole) of Polyol X450 is acylated with 336 parts (1.2 moles) of linolenic acid in xylene solution over a period of 6 hours at the reflux temperature. The water of esterification is removed by means of a side-arm water trap.

1451 parts (0.38 mole) of the above acylated Polyol X450, 125 parts (0.76 mole) of Pentaphen, 54 parts (0.38 mole) of phosphorus pentoxide, and 179 parts of xylene solvent are introduced into a flask and stirred vigorously. The whole is then refluxed for 6 hours while water is removed by means of a side-arm water trap. The product, a 50 percent solution of the acylated organic phosphate complex in xylene, shows the fol lowing analysis.

Percent phosphorus 1.31 Strong acid No. 56

Example 14 431 parts (0.375 mole) of Polyol X-450 is acylated with 140 parts (0.50 mole) of linoleic acid in 864 parts of xylene solvent over a period of 7 hours at the reflux temperature while water of esterification is removed by means of a side-arm water trap. Thereafter, 231 parts (1.41 moles) of Pentaphen and 71 parts (0.50 mole) of phosphorus pentoxide are added and the whole is refluxed for an additional 7 hours. The product, a 50 percent solution of the acylated organic phosphate complex in xylene, shows the following analysis.

Percent phosphorus 1.83 Strong acid No. 76

Example 15 575 parts (0.50 mole) of Polyol X-450 is acylated with 110 parts (0.39 mole) of linoleic acid in xylene solution over a period of 4 hours at the reflux temperature while water of esterification is removed by means of a side-arm water trap.

1200 parts (0.44 mole) of this acylated Poyol X-450, 63 parts (0.39 mole) of Pentaphen, 28 parts (0.20 mole) of phosphorus pentoxide, and 91 parts of xylene are placed in a flask and stirred vigorously. The whole is then heated 6 hours at the reflux temperature to prepare the product, which is a 50 percent solution in xylene of the desired acylated organic phosphate complex. It shows the following analysis.

Percent phosphorus 0.87 Strong acid No. 34

Example 16 575 parts (0.50 mole) of Polyol X450 is acylated with 187 parts (0.67 mole) of linoleic acid in 750 parts of xylene solvent over a period of 6 hours at the reflux temperature. The water of esterification is removed by means of a side-arm water trap.

1200 parts (0.40 mole) of this acylated Polyol X-450, 21 parts (0.13 mole) of Pentaphen, 25 parts (0.18 mole) of phosphorus pentoxide, and 46 parts of xylene solvent are introduced into a flask and stirred vigorously. The whole is heated for 6 hours at the reflux temperature. The product, a 50 percent solution in xylene of the acylated organic phosphate complex, shows the following analysis.

Percent phosphorus 0.81 Strong acid No. 32 Example 17 575 parts (0.5 mole) of Polyol X-450 is acylated with 746 parts (2.67 moles) of linoleic acid in 1000 parts of xylene solvent over a period of 10 hours at the reflux temperature. The water of esterification is removed by means of a side-arm water trap.

1890 parts (0.50 mole) of this acylate Polyol X-450, 63 parts (0.38 mole) of Pentaphen, and 3 2 parts (0.23 mole) of phosphorus pentoxide are introduced into a flask and stirred vigorously. The whole is then heated 6 hours at the reflux temperature. The product, a 58 percent solution of the acylate organic phosphate complex in xylene, shows the following analysis.

Percent phosphorus 0.76 Strong acid No. 31

Example 18 575 parts (0.50 mole) of Polyol X-450 is acylated with 287 parts (1.0 mole) of tung oil acids in xylene solvent (844 parts) over a period of 8 hours at the reflux temperature. The water of esterification is removed by means of a side-arm water trap.

1300 parts (0.39 mole) of this acylated Polyol X-450, 191 parts (1.16 moles) of Pentaphen, 55 parts (0.39 mole) of phosphorus pentoxide, and 246 parts of xylene solvent are introduced into a flask and stirred vigorously. The whole is then refluxed for 4 hours. The product, a 50 percent solution of the acylated organic phosphate complex in xylene, shows the following analysis.

Percent phosphorus 1.38 Strong acid No. 46

Example 19 575 parts (0.5 mole) of Polyol X-450 is acylated with 423 parts (1.5 moles) of oleic acid in 971 parts of xylene solvent over a period of 8 hours at the reflux temperature. The water of esterification is removed by means of a sidearm water trap.

1300 parts (0.34 mole) of this acylated Polyol X-450, 111 parts (0.68 mole) of Pentaphen, 48 parts (0.34 mole) of phosphorus pentoxide, and 159 parts of xylene solvent are introduced into a flask and stirred vigorously. The whole is then refluxed for 8 hours at about C. while the water of reaction is removed by means of a side-arm water trap. The product, a 50 percent of the acylated organic phosphate complex in xylene, shows the following analysis.

Percent phosphorus 1.11 Strong acid No. 46

9 Example 20 575 parts (0.5 mole) of Polyol X-450 is acylated with 141 parts (0.5 mole) of oleic acid in 707 parts of xylene solvent over a period of 8 hours at 140 C. The water of esterification is removed by means of a sidearm water trap.

1364 parts (0.48 mole) of this acylated Polyol X4SO, 237 parts (1.45 mole) of Pentaphen, 68 parts (0.48 mole) of phosphorus pentoxide, and 305 parts of xylene solvent are introduced into a flask and stirred vigorously. The whole is then heated 8 hours at the reflux temperature while the water of reaction is removed by means of a side-arm water trap. The product, a 50 percent solution of the acylated organic phosphate complex in xylene, eshows the following ananysis.

Percent phosphorus 1.53 Strong acid No. 54

Example 21 1725 parts (1.5 moles) of Polyol X-450, 1260 parts (4.5 moles) of linoleic acid, and 2904 parts of xylene solvent are refluxed for 6 hours while the water of esteri fication is removed by means of a side-arm water trap.

5808 parts (1.5 moles) of the resulting acylated Polyol X450, 492 parts (3.0 moles) of Pentaphen, 214 parts (1.5 moles) of phosphorus pentoxide, and 706 parts of xylene solvent are introduced into a flask and stirred vigorously. The whole is then refluxed for 8 hours while the water of reaction is removed by means of a side-arm water trap. The product, a 50 percent solution of the desired acylated organic phosphate complex in xylene, shows the following analysis.

Percent phosphorus 1.27 Strong acid No. 60

Example 22 300 parts (0.26 mole) of Polyol X450 is acylated with 194 parts (0.68 mole) of linoleic acid in 713 parts of xylene solvent over a period of 6 hours at the reflux temperature. The water of esterification is removed by means of a side-arm water trap. 171 parts (1.04 moles) of Pentaphen and 48 parts (0.34 mole) of phosphorus pentoxide are added to the reaction vessel and the whole is refluxed for an additional 6 hours, water being removed by means of a side-arm water trap. The product, a 50 percent solution of the acylated organic phosphate complex in xylene, shows the following analysis.

Percent phosphorus 1.56 Strong acid No. 64

Example 23 575 parts (0.5 mole) of Polyol X-450 is acylated with 140 parts (0.5 mole) of linoleic acid in 707. parts of xylene solvent containing parts of para toluenesulfonic acid catalyst over a period of 4 hours at the reflux temperature. The water of esterification is removed by means of a side-arm water trap and the reaction mixture is washed with warm water to remove the small amount of snlfonic acid catalyst employed.

530 parts (0.32 mole) of this acylated Polyol X-450, 52 parts (0.32 mole) of Pentaphen, 23 parts (0.16 mole) of phosphorus pentoxide, and 75 parts of xylene are introduced into a flask and stirred vigorously. The whole is then heated the reflux temperature for about 6 hours. The product, a 50 percent solution of the acylated organic phosphate complex in xylene, shows the following analysis.

Percent phosphorus 1.37 Strong acid No. 46

Example 24 549 parts (0.33 mole) of an acylated Polyol X-450 prepared in the manner set forth in Example 23 above,

10 162 parts (0.99 mole.) of Pentaphen, 42 parts (0.33 mole) of phosphorus pentoxide, and 400 parts of xylene solvent are introduced into a flask and stirred vigorously. The whole is heated for 6 hours at the reflux temperature to yield the desired product, a 42 percent solution of the acylated organic phosphate complex in xylene. The product has the following analysis.

Percent phosphorus 1.23 Strong acid No. 55

Example 25 1150 parts (1.0 mole) of Polyol X450, 852 parts (3.0 moles) of crude. linoleic acid derived. from tall OH, 2400 parts of xylene solvent, 328 parts (2.0 moles) of Pentaphen, and 142 .parts (1.0 mole) of phosphorus pentoxide are introduced into a reaction flask fitted with a side-arm water trap. The whole is heated for 4.5 hours at the reflux temperature to yield the product, a 50 percent solution of the acylated organic phosphate complex in xylene. It shows the fol-lowing analysis.

Percent phosphorus 1.14 Strong acid No 62 Example 26 863 parts (0.75 mole) of Polyol X-450, 639 parts (2.25 moles) of crude linoleic acid, 1700 parts of xylene solvent, 246 parts (1.5 moles) of Pentaphen, and 142 parts (1.0 mole) of phosphorus pentoxide are introduced into a flask equipped with a side-arm water trap. The whole is stirred and heated for 9 hours at the reflux temperature while the Water of reaction is removed as formed. The product, a 52 percent solution of the acylated organic phosphate complex in xylene, shows the following analysis.

Percent phosphorus 1.54 Strong acid No. 48

Example 27 1150 parts (1.0 mole) of Polyol X-450, 852 parts (3.0 moles) of linoleic acid, 1209 parts of xylene solvent, 328 parts (2.0 moles) of Pentaphen, and 230 parts (2.0 moles) of commercial, percent orthophosphoric acid are introduced into a flask equipped with a side-arm water trap. The whole is stirred and heated at the reflux temperature for 6.5 hours to yield the product, a 66.6 percent solution of the acylated organic phosphate complex in xylene. It shows the following analysis.

Percent phosphorus 1.21 Strong acid No. 45

Example 28 Percent phosphorus 2.47 Strong acid No. 60

Example 29 719 parts (0.625 mole) of Polyol X-450, 164 parts (1.0 mole) of Pentaphen, and 71 parts (0.5 mole) of phosphorus pentoxide, and 952 parts of xylene solvent are introduced into a flask fitted with a stirrer and a sidearm water trap. The whole is refluxed for 6 hours while the water of reaction is removed as formed.

494 parts (0.641 mole) of the resulting organic phosphate complex is acylated with 179 parts (0.641 mole) of linoleic acid over a 7 hour period at 154 C. The water of esterification is removed as formed by means of a side-arm water trap. The product, a 63 percent solution of the acylated organic phosphate complex in xylene, shows the following analysis.

Percent phosphorus 1.02 Strong acid No 32 Example 30 2155 parts (1.875 moles) of Polyol X-450 is acylated with 706 parts (2.5 moles) of crude linoleic acid derived from tall oil in 2310 parts of xylene solvent over a period of hours at 147 C. The water of esterification is removed by means of a side-arm water trap. Thereafter 1155 parts (7.05 moles) of Pentaphen and 355 parts (2.5 moles) of phosphorus pentoxide are added and the whole is heated for an additional 2 hours at 151 C. The product, a 65 percent solution of the acylated organic phosphate complex in xylene, shows the following analysis.

Percent phosphorus 2.26

Strong acid No. 59

Example 31 383 parts (0.33 mole) of Polyol X-450, 284 parts (1.0 mole) of linoleic acid, and 5 ml. of commercial, 85 percent phosphoric acid are heated for 3 hours at 140- 147 C. while the water of esterification is permitted to escape from the reaction vessel. Thereafter, 109 parts (0.66 mole) of Pentaphen and 77 parts (0.66 mole) of commercial, 85 percent phosphoric acid are added and the whole is heated for an additional 14.5 hours at 143-l50 C., While the water of reaction is removed as formed by means of a side-arm water trap. The solventfree, acylated organic phosphate complex is diluted with 254 .parts of aromatic petroleum spirits to lessen its viscosity. The product shows the following analysis.

Percent phosphorus 2.11 Strong acid No. 69

Example 32 863 parts (0.75 mole) of Polyol X-450 is acylated with 639 parts (2.25 moles) of linoleic acid in 1461 parts of xylene solvent over a period of 7.5 hours at 142-144 C. The water of esterification is removed as formed by means of a side-arm water trap. Thereafter, 246 parts (1.5 moles) of Pentaphen, 388 parts of xylene solvent, and 142 parts mole) of phosphorus pentoxide are added and the whole is heated for an additional 6 hours at 143 C. The water of reaction is removed by means of the side-arm water trap. The product, a 50 percent solution of the acylated organic phosphate complex in xylene, shows the following analysis.

Percent phosphorus 1.42 Strong acid No. 72

Example 33 383 parts (0.33 mole) of Polyol X-450 is acylated with 284 parts (1.0 mole) of linoleic acid in the presence of 5 ml. of commercial, 85 percent phosphoric acid as catalyst over a period of about 2.5 hours at 140-150 C. The water of esterification evolved is collected by means of a side-arm water trap. Thereafter, 109 parts (0.66 mole) of Pentaphen and 47.5 parts (0.33 mole) of phosphorus pentoxide are added and the whole is heated for one hour at 130152 C. and an additional 3.5 hours at 103-l29 C. The viscous, acylated organic phosphate complex is diluted with 258 parts of aromatic petroleum spirits to facilitate handling. The product shows the following analysis.

Percent phosphorus 1.94 Strong acid No 53 A number of laboratory and outdoor exposure tests were carried out to determine the utility of the hereindescribed acylated organic phosphate complexes as protective coating compositions per se for metals and as ingredients in siccative organic coating compositions such as paints, varnishes, lacquers, primers, synthetic resins, enamels, etc. They are also useful as ingredients in water base or emulsion paints such as synthetic latex paints derived from acrylic resins, polyvinyl alcohol resins, alkyd resins, etc., by emulsification thereof with water, as well as water-soluble paints or primers derived from water-soluble alkyd resins, acrylic resins, and the like. The complexes of this invention may be applied to metal surfaces by any one of the methods ordinarily used in the paint and varnish industry such as brushing, spraying, dip-coating, flow-coating, roller-coating, and the like. The viscosity of the complex or the coating composition containing the complex may be adjusted for the particular method of application selected by adding a suitable amount of a solvent such as benzene, xylene, mesitylene, aromatic petroleum spirits, turpentine, or other appropriate solvents. The metal surface which has been thus coated is then dried either by exposure to air or by means of a baking procedure. A dried film thickness of the complex or the coating composition containing the complex ranging from about 0.01 mil to about 4 mils, preferably 0.02-2 mils, is usually required to provide adequate protection for the metal surface. Coatings heavier than 4 mils can be used, if desired, but they normally contribute little in the way of additional protection. In some instances, it is desirable to admix the complex with a pigment such as titanium dioxide, chrome green, aluminum powder, carbon black, iron oxide, or zinc chromate. In some instances it is also desirable to include conventional improving agents such as pigment extenders, anti-skinning agents, driers, gloss agents, color stabilizers, etc.

Example A Three 4-inch x 8-inch panels of clean, degreased, galvanized, 20-gauge SAE 1020 cold-rolled steel were coated in the manner set forth below; scribed with a pointed instrument to yield a V beginning one inch from a bottom corner of the panel, extending to one inch from the opposite side, and returning to a point one inch from the other bottom corner; and then exposed at a 45 angle for a period of one year to the weather prevailing in the Great Lakes region of the United States.

Thereafter, the panels were inspected for loss of the coating in the area adjacent to the scribe or score. The latter, designated as the undercut rating, is the average loss of coating from each side of the scribe expressed as an integer which represents the number of thirtyseconds of an inch of such loss.

It will be noted that a complex of this invention was substantially more effective than a widely used commercial primer in reducing the extent of undercutting, despite the fact that the film thickness of the complex was only one-tenth that of the commercial primer.

Example B Four 4-inch x 8-inch panels of clean, degreased, 20- gauge SAE 1020 cold-rolled steel were brush-coated, re-

13 spectively, with four different aluminum pigmented paints to yield films having a dry thickness of 0.5-* -0.1 mil. Each panel was V-scribed on the front face and then exposed at a 45 angle for a period of 15 months to the Weather prevailing in the Great Lakes region. The front and rear faces of each panel were inspected for rusting and rated on a scale of to 10, zero denoting a completely rusted panel and 10 denoting a rust-free panel.

It will be noted that an aluminum-pigmented complex of this invention was superior to three known aluminumpigmented paints in inhibiting the rusting of plain steel.

Example C Three 4-inch x 8-inch panels of rusted, ZO-gauge SAE 1020 cold-rolled steel (rusted by exposure to the weather for 2 months) were provided, respectively, with films of 1.7:02 mil thickness (measured on the dried film) of several protective coating compositions. The coated, pre-rusted panels were then exposed at a 45 angle for one year to the weather prevailing in the Great Lakes region and inspected for a break-through of the rust. The front and rear faces of each panel were given a rerust rating on a scale of zero to 10, zero denoting a completely re-rusted panel and 10 denoting a rust-free panel (i.e., free from visible surface rust).

Outdoor Exposure Test, Re-rust Rating Protective Coating Composition Front Rear face face Equal parts by weight of a commercial alkyd spar varnish and the product of Example 1 10 10 Equal parts by weight of linseed oil and the product of Example 1 9 10 Commercial plasticized organic phosphate paint. 0 1

The above results point out the utility of the complexes of the present invention as rust-inhibiting ingredients in known siccative organic coating compositions.

Example D Five pre-rusted, 4-inch x 8-inch panels of 20-gauge SAE 1020 cold-rolled steel were brush-coated, respectively, with different primers, brush-coated with a good, commercial, white enamel, and then exposed at a 45 angle for 17 months to the weather prevailing in the Great Lakes region. The front and rear faces of each panel were inspected for a break-through of the rust and rated as in Example C.

The above results point out the utility of the complexes of this invention as primers for pre-rusted steel which is to receive a top-coat of a known siccative organic finish.

Example E Three Z-foot sections of degreased, 2-inch x 2-inch x 43-inch hot-rolled angle iron were brush-coated, respectively, with three different protective coating compositions to yield a film, when dry, of 2:0.3 mil thickness. The coated angle irons were exposed in inverted-V fashion for 4 months to the weather prevailing in the Great Lakes region and then inspected for the condition of the coating and the development of rust.

Protective Coating Composition Outdoor Exposure Test,

Inspectors Remarks Coating has become chalky; rust developing beneath it has Stained the coating.

Another commercial organic Do.

phosphate resin.

Product of Example 21 Commercial organic phosphate resin.

Coating is clear and hard; no rust beneath it.

These results illustrate the utility of the complexes of this invention as protective coating materials per se for hot-rolled, heavy-gauge iron.

Example F Three Meehanite (calcium silicide-treated cast iron) castings having the form of an open box were dip-coated, respectively, in three different protective coating compositions, allowed to air-dry, and then exposed with the open side inverted for 3.5 months to the weather prevailing in the Great Lakes region. The castings were then visually inspected to determine the extent to which they had rusted.

Outdoor exposure test, percent of total Protective coating composition: area rusted Commercial alkyd spar varnish 50 Commercial organic phosphate resin 30 Product of Example 21 10 Example G Water Immersion Test, Condition of Coating on Panel Immersed at Protective Coating Composition Ambient temperature Commercial organic phosphate Surface covered Surface turned resin. with loose white and powder. powdery. Product of Example 21 Surface clear Surface lost and hard. some of its gloss. Product of Example 18 ..do D0.

The above test results show the ability of the complexes of the present invention to withstand deterioration in the presence of Water.

Example H Three 4-inch x 8-inch panels of clean, degreased, 20- gauge SAE 1020 cold-rolled steel were spray-coated, respectively, with three different chrome green-pigmented coating compositions and allowed to air dry. Thereafter, each coated panel was line-scribed with a pointed instrument to yield a vertical scribe beginning one-inch from 1 5 the top of the panel and ending one inch from the bottom thereof.

The coated and scribed panels were subjected to a Salt Fog Corrosion test for 120 hours. The apparatus used for this test is described in ASTM procedure Bll7-57T. It consists of a chamber in which a mist or fog of 5 percent aqueous sodium chloride solution is maintained in contact with the panels at 95i2 F. The panels were then removed from the chamber and scraped vigorously with a putty knife to remove any coating which had separated from the metal substrate. Each panel was inspected to determine the percent of the total area thereof which was still covered with an adherent coating (reported as elcnt Of cOatin adheled).

Salt fog COII'OSlOll test ercent of Protective coating composition: fi adhered In addition to their utility as protective coating materials for ferrous metals, the acylated organic phosphate complexes of this invention are useful in protecting non-fer rous metals and alloys thereof such as aluminum, magnesium, copper, brass, bronze, white metal, etc., against corrosion. They are also useful as protective coating materials on galvanized ferrous surfaces, on plated metal surfaces such as, e.g., copper-plated, nickel-plated, and cadrnium-plated ferrous surfaces, and on phosphated metal surfaces. They are also useful as protective coating materials on chromated aluminum or chnomated zinc surfaces, i.e., aluminum or zinc surfaces which have been treated with an aqueous solution of chromic acid and/ or a derivative thereof such as a metal chromate or dichromate, an amine chromate, ammonium chromate, etc. Particularly fine results are obtained when the coating compositions of the present invention are applied over a metal surface which has been phosphated by means of a novel aqueous phosphating solution containing as essential ingredients zinc ion, phosphate ion, nitrate ion, and a cation selected from the group consisting of lithium, beryllium, magnesium, calcium, strontium, cadmium, and barium. Such phosphating solutions, which provide a dense, adherent, micro-crystalline or amorphous phosphate coating upon the metal substrate, are described in detail in copending US. application, Ser. No. 373,449, now US. Patent 3,090,709, filed August 10, 1953. It is intended that the entire disclosure of Ser. No. 373,449 be incorporated herein by reference.

What is claimed is:

1. An acylated organic phosphate complex prepared by the process which comprises the reaction of:

(A) one mole of a phosphorus-containing reagent selected from the group consisting of phosphorus pentoxide and phosphoric acids,

(B) from about 0.2 to about 5 moles of a co-polymer of allyl alcohol and a styrene,

(C) from about 0.5 to about 5 moles of an alkylphenol,

and

(D) from about 0.5 to about 4 moles per mole of (B) employed of an unsaturated aliphatic mono-carboxylic acid compound selected from the group consisting of high molecular weight unsaturated aliphatic carboxylic acids containing at least about 12 carbon atoms and esters of such acids, at a temperature within the range from about 50 C. to about 300 C. for about 0.5 to about 30 hours.

2. A complex in accordance with claim 1 characterized further in that the phosphorus-containing reagent of (A) is phosphorus pentoxide.

3. A complex in accordance with claim 1 characterized further in that the copolymer of (B) is a copolymer of about equimolar amounts of allyl alcohol and styrene and has an average molecular weight in the range from about 500 to about 5,000.

4. A complex in accordance with claim 1 characterized further in that the alkylphenol of (C) is para-tertiary amylphenol.

5. A complex in accordance with claim 1 characterized further in that the unsaturated aliphatic carboxylic acid compound of (D) is linoleic acid.

6. A complex in accordance with claim 1 characterized further in that the copolymer of (B) is first acylated with the unsaturated aliphatic carboxylic acid compound of (D) and then such acylated copolymer is reacted with the phosphorus-containing reagent of (A) and the alkylphenol of (C).

7. A method for inhibiting the corrosion of a metal surface which consists of applying thereto a film comprising the complex of claim 1.

8. A method in accordance with claim 7 wherein said film comprises a major proportion of a siccative organic coating composition and a min-or proportion of the complex of claim 1.

9. A method in accordance with claim 7 characterized further in that the metal surface is a ferrous metal surface.

10. A metal article the metal surface of which has been protected against corrosion in accordance with the method of claim 7.

11. A metal article the metal surface of which has been protected against corrosion in accordance with the method of claim 8.

References Cited by the Examiner UNITED STATES PATENTS 2,005,619 6/35 Graves 252-32.5 2,894,938 7/59 Chapin et a1 260-881 3,055,865 9/62 Craig 106-14 FOREIGN PATENTS 757,043 9/ 56 Great Britain.

LEON I. BERCOVITZ, Primary Examiner. ALPHONSO D. SULLIVAN, Examiner.

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US2005619 *Nov 10, 1934Jun 18, 1935Du PontEsters of acids of phosphorus
US2894938 *Jan 12, 1955Jul 14, 1959Monsanto ChemicalsCopolymer of a styrene compound and an unsaturated alcohol
US3055865 *Aug 22, 1960Sep 25, 1962Lubrizol CorpProcess of preparing film-forming compositions
GB757043A * Title not available
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3984500 *Oct 14, 1975Oct 5, 1976Ford Motor CompanyRadiation polymerizable coating composition containing an unsaturated phosphoric ester
US4242243 *Jul 18, 1979Dec 30, 1980E. I. Du Pont De Nemours And CompanyHigh solids ambient temperature curing coatings of acrylic-fatty acid drying oil resins
US4380035 *Sep 4, 1980Apr 12, 1983Tdk Electronics Co., Ltd.Magnetic tape cassette
USRE31309 *Jul 7, 1981Jul 12, 1983E. I. Du Pont De Nemours And CompanyHigh solids ambient temperature curing coatings of acrylic-fatty acid drying oil resins
Classifications
U.S. Classification525/149, 106/14.34, 528/167, 528/205, 525/133.5, 428/463, 524/136, 524/353, 252/389.2, 428/461, 524/318
International ClassificationC09D5/08, C08G79/00, C08G79/04
Cooperative ClassificationC09D5/086, C08G79/04
European ClassificationC08G79/04, C09D5/08B4