Corrosion prevention constituent for surface coatings

Abstract

A corrosion-preventing soyabean-glycerol alkyd resin is preprared by combng soyabean oil and glycerol in a reaction kettle, and after heating to about 400.degree. F., fused litharge is loaded. The temperature is then increased to about 440.degree. F. and held until a clear solution is formed. Phthalic anhydride is then loaded and heat gained cautiously to about 450.degree. F. Butylphenol resin is loaded. Then China wood oil is loaded. A first carbon dioxide blow is commenced. Then a second carbon dioxide blow is initiated. The mixture is then cooled to about 425.degree. F. and held. The mixture is dropped into xylene and thinned with Varnish Makers' and Painter's Naptha (petroleum thinner) prior to use with the barium metaborate corrosion preventer compound of this invention which was developed to replace chromium which has reduced availability due to exportation restrictions from the major supplier country. The corrosion prevention surface primer coating composition of this invention comprises a weight percent range of 30-32 of the above soyabean-glycerol alkyd resin; 36-38 weight percent barium metaborate; 6-7 weight percent phenol formaldehyde; metal compound additives of titanium dioxide 5-6 weight percent, black iron oxide 1-2 weight percent, magnesium silicate 5-7 weight percent, and aluminum silicate; of 0.3 to 0.6, pertroleum thinner 10.0-12.2 weight percent; butanol 0.4 to 0.8 weight percent; and napthenate drying agents 0.1 to 0.3 weight percent each of cobalt napthenate, manganese naphthenate, and iron napthenate.

Description

BACKGROUND OF THE INVENTION

Chromium has been extensively used in corrosive inhibiting compositions and mixtures. For example, zinc chromate, also known as pigment yellow 36, has been used as pigment in paints, varnishes, oil colors, linoleum, rubber etc.

With the reduced availability of chromium because of restrictions placed on its exportation by a principle supplier country, it becomes critical to develop alternate materials for use as corrosion-inhibiting ingredients in surface coatings for defense and commercial uses.

Therefore, an object of this invention is to provide a non-critical source of a corrosion preventer.

A further object of this invention is to provide a corrosion preventer compound which is easily formulatd into an alkyl resin used in the production of fast drying coatings for light metal alloys surfaces.

SUMMARY OF THE INVENTION

The corrosion preventer compound of this invention is barium metaborate which is formulated with a corrosion-preventing alkyd resin to yield a surface coating with improved corrosion resistance properties as compared with a similar primer coating employing the standard zinc chromate corrosion preventer.

The corrosion-preventing alkyd resin is further defined in Table I by the ingredients it contains and by the manufacturing procedure therefor set forth under Table I below.

TABLE I______________________________________COMPARISON AND METHOD OF MANUFACTURE OF ACORROSION - PREVENTING ALKYD RESININGREDIENT/MANUFACTURE WEIGHTPROCEDURE CHARACTERISTICS (lbs)______________________________________INGREDIENTSSoyabean Oil 175.0Glycerol 90.5Fused litharge .25Phthalic anhydride 161.0Butylphenol resin 13.5China wood oil 88.5Xylene 353.5Varnish Makers & Painters' Naptha 151.5(petroleum thinner)______________________________________MANUFACTURING PROCEDURE TEMPER-TIME ATURE OPERATION______________________________________ Soyabean oil loaded into reaction kettle Glycerol loaded0:00 Heat on1:30 400.degree. F. Litharge loaded2:00 440.degree. F. Gained2:30 440.degree. F. Hold until clear solution formed2:30 430.degree. F. Phthalic anhydride loaded2:45 450.degree. F. Gained cautiously4:30 450.degree. F. Butylphenol resin loaded4:40 450.degree. F. China wood oil loaded4:50 450.degree. F. 20 CFM carbon dioxide blow5:20 450.degree. F. 30 CFM carbon dioxide blow Allowed to cool to 425.degree. F.5:40 425.degree. F. Held until desired viscosity is obtained6:30 425.degree. F. Dropped into xylene Thinned with Varnish Makers' & Painters' Naphtha (petroleum thinner)______________________________________

DESCRIPTION OF THE PREFERRED EMBODIMENT

Barium metaborate is employed as corrosion preventer compound in a corrosion-resistant primer coat formulation set forth in Table II. The soyabean-glycerol alkyd resin employed in this formulation is prepared by the manufacturing procedure set forth in Table I hereinabove.

TABLE II__________________________________________________________________________A COMPARISON OF THE COMPOSITION OF CORROSION -RESISTANT PRIMER COATS Parts by WEIGHT Parts by WEIGHTINGREDIENT COMPOSITION A % COMPOSITION B % Range %__________________________________________________________________________Zinc chromate 74.3 37.15 0 0 0Barium metaborate 0 0 74.3 36.00-38.00 37.15(corrosion preventercompound)Metal compound additives:Titanium dioxide 10.9 5.45 10.9 5.00-6.00 5.45Black iron oxide 2.9 1.45 2.9 1.00-2.00 1.45Magnesium silicate 10.9 5.45 10.9 5.00-7.50 5.45Aluminum stearate 1.0 0.50 1.0 0.30-0.60 0.50Phenol-formaldehyde dis- 13.2 6.60 13.2 6.00-7.00 6.60persion resinSoyabean-glycerol 62.2 31.10 62.2 30.00-32.00 31.10alkyd resin (TABLE I)Petroleum thinner 22.4 11.20 22.4 10.00-12.20 11.20n-Butanol 1.3 0.65 1.3 0.40-0.80 0.65Napthenate drying agent:Cobalt naphthenate 0.3 0.15 0.3 0.10-0.30 0.15Manganese naphthenate 0.3 0.15 0.3 0.10-0.30 0.15Iron naphthenate 0.3 0.15 0.3 0.10-0.30 0.15 100.00 100.00__________________________________________________________________________

The evaluation of surface coating composition A and composition B is set forth below under Table III.

TABLE III______________________________________EVALUATION OF SURFACE COATINGS______________________________________Surface steelNumber of coats 1Undercoat noneMethod of application sprayReducer xylene______________________________________

Evaluation of the corrosion resistance of these primers was carried out by spraying, after thinning with xylene, to spray viscosity, of one coat (4-mil thickness) onto bonderized steel panels. All surfaces were sprayed, including the edges of the panels. The panels were allowed to air-dry for 72 hours. The panels were then lowered into distilled water and allowed to remain until signs of corrosion were detected.

Composition A started to show signs of corrosion after 45 days, whereas Composition B did not show corrosion even after 60 days. At that time it was obvious that the test had effectively established the superior corrosion resistance of Composition B, and the test was discontinued.

Claims

1. A corrosion prevention surface primer coating composition as specified in weight percent ranges set forth in Table II hereinbelow for the ingredients comprising a corrosion-preventing soyabean-glycerol alkyd resin; a corrosion preventer compound barium metaborate; a dispersion resin; metal compounds as additives; petroleum thinner; n-butanol, and napthenate drying agents, said corrosion-preventing soyabean-glycerol alkyd resin prepared from the ingredients and by the manufacture procedure set forth under Table I as follows:

TABLE I______________________________________INGREDIENTS/MANUFACTURE PROCEDUREINGREDIENTS WEIGHT (lbs)______________________________________Soyabean oil 175.0Glycerol 90.5Fused litharge .25Phthalic anhydride 161.0Butylphenol resin 13.5China wood oil 88.5Xylene 353.5Petroleum thinner 151.5______________________________________MANUFACTURING PROCEDURE TEMPER-TIME ATURE OPERATION______________________________________ Soyabean oil loaded into reaction kettle Glycerol loaded0:00 Heat on1:30 400.degree. F. Litharge loaded2:00 440.degree. F. Gained2:30 440.degree. F. Hold until clear solution formed2:30 440.degree. F. Phthalic anhydride loaded2:45 450.degree. F. Gained cautiously4:30 450.degree. F. Butylphenol resin loaded4:40 450.degree. F. China wood oil loaded4:50 450.degree. F. 20 CFM carbon dioxide blow5:20 450.degree. F. 30 CFM carbon dioxide blow Allowed to cool to 425.degree. F.5:40 425.degree. F. Held6:30 425.degree. F. Dropped into xylene Thinned with petroleum thinner,______________________________________

said Table II identified hereinabove and set forth hereinbelow with ingredients and composition weight percent range as follows:

TABLE II______________________________________CompositionIngredients Weight Percent, Range______________________________________Corrosion-preventing 30.00-32.00soyabean-glycerol alkydresin (Table I)Barium metaborate (corrosion 36.00-38.00preventer compound)Phenol-formaldehyde (dis- 6.00-7.00persion resin)Metal compound additives:titanium dioxide 5.00-6.00black iron oxide 1.00-2.00magnesium silicate 5.00-7.50aluminum silicate 0.30-0.60Petroleum thinner 10.00-12.20 -n-Butanol 0.40-0.80Naphthenate drying agents:cobalt naphthenate 0.10-0.30manganese naphthenate 0.10-0.30iron naphthenate 0.10-0.30.______________________________________

2. The corrosion prevention surface primer coating composition as defined in Table II of claim 1 wherein said composition ingredient weight percents are as set forth in Table III as follows:

TABLE III______________________________________CompositionIngredients Weight Percent______________________________________Corrosion-preventing soyabean-glycerol alkyd 31.10resin prepared from ingredients and bymanufacture procedure of Table IBarium metaborate (corrosion preventer 37.15compound)Phenol-formaldehyde dispersion resin 6.60Metal compound additives:titanium dioxide 5.45black iron oxide 1.45magnesium silicate 5.45aluminum silicate 0.50Petroleum thinner 11.20n-Butanol 0.65Napthenate drying agent:cobalt naphthenate 0.15manganese naphthenate 0.15iron naphthenate 0.15TOTAL 100.00.______________________________________