US2978423A

US2978423A - Anti-rust compositions

Info

Publication number: US2978423A
Application number: US670398A
Authority: US
Inventors: Tirtiaux Robert; Signouret Jean Baptiste
Original assignee: Esso Standard SA
Current assignee: Esso SA
Priority date: 1956-07-11
Filing date: 1957-07-08
Publication date: 1961-04-04
Anticipated expiration: 1978-04-04
Also published as: GB807670A; FR1155969A; DE1067955B

Description

ANTI-RUST COMPOSITIONS Robert Tirtiaux, Notre-Dame de Gravenchon, and Jean Baptiste Signouret, Pau, France, assignors to Esso Standard Societe Anonyme Frangaise, Paris, France, a body corporate of France phenol formaldehyde copolymers and to the use of these copolymers in anti-rust compositions.

Rust inhibiting agents are known which will retard rust formation of an iron surface. It is believed that rusting is catalysed by the existence of centres of rust and that the rust inhibiting agent destroys the auto-catalytic effect of the rust by destroying the gel-like structure of the rust. Another and more obvious method of preventing corrosion of an iron surface is to completely protect the surface, by means of an impermeable skin, from the elfects of the surrounding atmosphere.

It has been found difiicult to permanently protect a metal surface by means of oil unless fresh,applications of oil are periodically applied. Even with thick oils and oils which have been thickened by the addition of petrolatum, the oil film does not remain continuous, and rusting will occur. It is believed that protection of an iron surface against rust by means of an oil film is not possible for two reasons. Firstly, the oil film breaks up and leaves active centres of the surface unprotected from the atmosphere; and secondly, that condensed water has a greater aifinity for the metal surface than the oil and in time the water displaces the oil on the surface of the metal.

.The present investigation was undertaken in order to devise a copolymer which, when added to a lubricating oil, would give a composition that would form a lasting and impermeable film on the metal surface. A suitable polymer as described hereafter, derived from phenol and formaldehyde was devised, and on further experimentation, it was discovered that if alkaline metal naphthenates or sulphonates were added to an oil solution of this copolymer, an eflicient rust inhibiting composition was obtained. This discovery was unexpected since the composition Was found to be far superior to either a composition consisting of lubricating oil and the copolymer, or a composition of lubricating oil and the alkaline metal naphthenates or sulphonates. The effectiveness of the composition of the present invention is dependent on the synergistic effect of the copolymer and the alkaline salts of sulphonates or naphthonates when in an oil solution.

The rust inhibiting composition of the present invention comprises an oil, alkoxylated phenol formaldehyde copolymer and an oil-soluble alkaline metal naphthenate h or sulphonate.

United States Patent F thenates or sulphonates may be dispersed in a drying oil, I Pigments such as which may be natural or synthetic. metal oxides may be included. It is desirable to include in the rust preventing compositions bitumons or coal tar.

The copolymers of the present invention are prepared by copolymerising formaldehyde, which may be in the iform of a formaldehyde polymer, with an alkoxylated phenol. The term alkoxylated phenol refers to the product obtained by reacting an alkylene oxide with a phenol. h

The preferred phenols are mono and di-alkyl derivatives of phenol in which the alkyl group or alkyl groups each contain from 6 to 20 carbon atoms and preferably from 6 to 12 carbon atoms. The alkyl phenols may be formed by alkylating a phenol with an olefin in the presence of a Fried'el-Crafts catalyst; the alkyl phenols soobtained having branch chain alkyl groups. Suitable examples of alkyl phenols are n-octyl phenol, iso-octyl phenol, ditertiary butyl phenol, isobutyl phenol, amyl phenol and heptyl phenol. The alkyl groups are prefer-' ably situated ortho or para with respect to the phenolic group.

The alkylene oxide 'used to prepare the alkoxylated phenol may have from 2 to 6 carbon atoms and prefer" The alkoxyl ably is ethylene oxide or propylene oxide. ated phenol may be prepared by reacting the alkylene l oxide, such as ethylene oxide, with a phenol in the presonce of a suitable inert solvent, such as hydrocarbon, in the presence of catalytic amounts of a Friedel-Crafts catalyst such as boron trifluoride. It is preferable to fix from 1 to 4 mols of the alkylene oxide on 1 mol of the 1 alkyl phenol. Alternatively, the alkoxylated alkyl phenol The oil that may be used in the compositionmay be synthetic, natural or mineral oil. For reasons of economy it is preferable to use a mineral oil which may be a lubricating oil such as a spindle oil having a viscosity of to S.U.S. at 100 F., or a cylinder oil. An oil with a viscosity within the range 100 to 500 S.U.S. at 100 F. may be used. In order to increase the viscosity of the composition petrolatum may be added until a consistency similar to that of vaseline is obtained.

When it is desired to use the composition in rust preventing paints, the copolymer and alkaline metal naph may be prepared by condensing a polyal-kylene glycol, preferably containing from 1 to 4 glycol residues, with the alkyl phenol.

The alkoxylated phenol may be copolymerised with the formaldehyde in the presence of an alkaline or Friedel- Crafts catalyst. Ammonia and sodium hydroxide and potassium hydroxide are suitable alkylene catalysts, and.

boron trifluoride in the form of boron trifluoride/ether complex, is a particularly preferred Friedel-Crafts catalyst. The copolymerisation may be affected by heating a mixture of the alkoxylated alkyl phenol, preferably ethoxylated phenol, and formaldehyde at a temperature of to C. for a period for 5 to 7 hours and preferably for a' period of about 6 hours.

Ammonia may be included in the copolymer by copolymerising formaldehyde, ammonia and the alkoxylated phenol. The copolymerisation may be carried out by heating formaldehyde, ammonia and alkoxylated alkyl; phenol at a temperature of 150 to 160 C. for 5 to 7 hours, preferably for a time of about 6 hours. The best method of copolymerising with ammonia is to inject am: monia into a mixture of the alkoxylated alkyl phenol and formaldehyde at a low temperature, for example 50 to 60. C., for a period of 5 to 6 hours, stopping the addition of ammonia andthen heating the reactants to a higher temperature of the order of 100 to 160 C. and prefer: ably to 100 to 110 C., and maintaining the heating at the higher'temperature for a period of 5 to 7 hours.

The product of the-- polymerisation process may be .freed of volatile materials by stripping in vacuo and dispolymer.

solved in mineral oil to give a concentrate of the co- A suitable copolymer concentrate contains about 50 wt. percent of the copolymer.

The preparationv of resin A and resin B serves as an illustration of the process used to prepare the copolymers.

2,978,423 Patented Apr. 4, 19 61 reacted at 120 to 130 C. using 0.5% of boron trifluoride/ether complex as catalyst, and the alkoxylated octyl phenol (100 g.), so obtained was copolymerrsed with trioxymethylene (15 g.) using 0.5 g. boron tritluoride/ether complex as catalyst, at a temperature between 110 and 120 C. for 6 hours. The product was then dispersed in a mineral oil (100 g.) of viscosity index 140 and viscosity at 37.8 C. of 32.1 centistokes. Filtration at 120 C. gave a 50% solution of resin A.

EXAMPLE 2 Preparation of resin B The ethoxylated octyl phenol, prepared as in Example 1 (100 g.), was copolymerised with trioxymethylene (15 g.) using boron trifluoride/ether complex as a catalyst, at 60 to 65 C. for 5 hours. During this stage of the process ammonia was continuously injected into the monomer mixture. Injection of the ammonia was then stopped and the heating was continued for a further 2 hours at 150 C., and the product so obtained was dispersed in spindle oil (100 g.). Filtration at 120 C. afforded 50% concentrate of resin B.

The properties of compositions according to the present invention containing resin A and resin B are shown in Tables I and II. The concentrates may be conveniently diluted to prepare the desired compositions which may contain from 0.1 to by weight of the copolymer, and preferably from 0.5 to 5% by weight of the copolymer.

The sulphonates are alkaline metal sulphonates, sodium being the preferred alkaline metal. The sulphonates may be oil-soluble petroleum sulphonates such as the mahogany acids. The sulphonates may be a mixture of sulphonates containing from 12 to 25 carbon atoms and preferably from 14 to 18 carbon atoms or a molecular weight of 400 to 600. It is preferred that the composition of the present invention contains from 0.5 to 5% by weight of alkaline metal sulphonates.

Oil-soluble alkaline metal naphthenates may be used in place of the sulphonates. Sodium naphthenates are preferred having from 8 to 18 carbon atoms per molecule.

It has also been discovered that the composition may be particularly improved by the addition of animal fatty oils or wool fats such as suintine, lanolin, degras. The advantages derived from the addition of suintine, which may be added to the order of 10 wt. percent are clearly demonstrated in Table I. It is also desirable to include in the composition polyvalent metal salts of sulphenated fatty acids, naphthenic acids, or phenols. Examples of suitable polyvalent metals for use in salts are lead, copper, iron, tin, zinc and manganese. The inclusion of lead naphthenates and/or zinc naphthenate of the order of 2 /2 wt. percent is advantageous.

It is also desirable to include in the composition up to 10% of polyalcohols of natural animal or vegetable origin such as suintine, degras, lanolin, spermacetic oil, beeswax and Chinese wax.

The synergism exhibited by the composition of the present invention is demonstrated by Table I and Table II.

TABLE I 10 subjected to these conditons to show the first signs of rust, measures the resistance time of the anti-rust composition in question and therefore, its eflicacy.

TABLE II Compgsition; Humidification test. time in hours A. 5 wt. percent lanolin 10 wt. percent sodium sulphonates 1 710 35 wt. percent naphthenic oil 100 SUS at 100 F. 20 B. 98.4 wt. percent composition A plus 1.6 wt.

percent resin A 790 C. 98.4 wt. percent composition A plus 1.6 wt.

percent resin B 800 D. 10 wt. percent lanolin 10 wt. percent sodium sulphonates 1 460 80 wt. percent white spirit E. 98.4 wt. percent composition D plus 1.6 wt.

percent resin A 500 F. 98.4 wt. percent composition D plus 1.6 wt. percent resin B -2 500 1 The sodium sulphonates were sodium petroleum sulphonates with a molecular weight of 440460.

The humidification test referred to in Table II. was

measured in a humidity cabinet fitted with an air line delivering a fixed rate of air, a water heater and a thermostat to maintain a temperature of 100 F., and an air line delivering air through diffusion discs at a specified rate. The test panels are of mild steel which is sand-blasted to a uniform rust-free surface and then 1. A rust inhibiting composition consisting essentially of oil, about 0.1 to 10.0 wt. percent of a polymeric material consisting of an alkoxylated alkyl phenolformaldchyde copolymer and about 0.05 to 5.0 wt. percent of an oil soluble material selected from the group consisting of alkali metal sulfonates of 12 to 25 carbon atoms and alkali metal naphthenates of 8 to 18 carbon atoms, and

' wherein said alkoxylated alkyl phenols contains about one to four C to C alkylene oxy groups per molecule and about one to two C to C alkyl groups per molecule.

2. A rust inhibiting composition consisting essentially of a major proportion of mineral oil, about 0.1 to 10.0 wt. percent of a polymeric material prepared by copolymerizing a group of reactants consisting of formaldehyde, ammonia and an alkoxylated alkyl phenol, and about 0.5 to 5.0 wt. percent of an oil soluble material selected from the group consisting of alkali metal sulfonates of Anti-rust compositions Percentages by weight Formula VII VIII IX X XI XII Oil of viscosity at 37.8 C.,

32.1 centistokes 95.8 94.2 94.2 95

Oil of viscosity at 37.8 C.,

centistokes Resin A (50% solution) Resin B (50% solution) Nn. sulphonate of molecular weight about 500(50%soln.)- 4.2 4. 2 4.2 4.2 Suintine Humidification test, Time in a hours 20 520 490 12 12 15 5 12 to 25 carbon atoms and alkali metal naphthenatcs of 8 to 18 carbon atms,'and wherein said alkoxylated alkyl phenol contains about one to four C to C alkylene oxy groups per molecule and about one to two C to C alkyl groups per molecule.

3. A rust inhibiting composition consisting essentially of a major proportion of mineral oil, about 0.5 to 5.0 wt. percent of a polymeric material consisting of an ethoxylated alkyl phenolformaldehyde copolymer, about 0.05 to 5.0 wt. percent of an oil soluble sodium sulfonate of 12 to 25 carbon atoms, and up to 10 wt. percent of a material selected from the group consisting of suintine and lanolin, wherein said ethoxylated alkyl phenol contains one to two C to C alkyl groups per molecule.

4. A method of preventing rusting of iron surfaces which comprises coating said surface with a film of a rust inhibiting composition comprising a major proportion of mineral oil, 0.1 to 10.0 wt. percent of an alkoxylated alkyl phenol-formaldehyde copolymer, and about 0.05 to .0 wt. percent of an oil soluble material selected from the group consisting of alkali metal sulphonates of 12 to 25 carbon atoms and alkali metal naphthenates of 8 to 18 carbon atoms, wherein said alkoxylated alkyl phenol contains about one to four 0, to C alkylene oxy groups per molecule and about one to two C to C alkyl groups per molecule. I

I 5. A method of preventing rusting of iron surface which comprises coating said surface with a film of a rust inhibiting composition comprising a major amount of mineral oil, 0.5 to 5.0 wt. percent of an ethoxylated alkyl phenol-formaldehyde copolymer, and about 0.05 to 5.0 wt. percent of an oil soluble sodium sulphonate of 12 to 25 carbon atoms and wherein said ethoxylated alkyl phenol contains about one to four ethylene oxy groups per molecule and about one to two C to C alkyl groups per molecule.

References Cited in the file of this patent UNITED STATES PATENTS OTHER REFERENCES Baker et al.: Polar-Type Rust Inhibitors, pages 2338- 2347, Industrial and Engineering Chemistry, volumn 40, No. 12 (December 1948).

Claims

1. A RUST INHIBITING COMPOSITION CONSISTING ESSENTIALLY OF OIL, ABOUT 0.1 TO 10.0 WT. PERCENT OF A POLYMERIC MATERIAL CONSISTING OF AN ALKOXYLATED ALKYL PHENOLFORMALDEHYDE COPOLYMER AND ABOUT 0.05 TO 5.0 WT. PERCENT OF AN OIL SOLUBLE MATERIAL SELECTED FROM THE GROUP CONSISTING OF ALKALI METAL SULFONATES OF 12 TO 25 CARBON ATOMS AND ALKALI METAL NAPHTHENATES OF 8 TO 18 CARBON ATOMS, AND WHEREIN SAID ALKOXYLATED ALKYL PHENOLS CONTAINS ABOUT ONE TO FOUR C2 TO C6 ALKYLENE OXY GROUPS PER MOLECULE AND ABOUT ONE TO TWO C6 TO C20 ALKYL GROUPS PER MOLECULE.