US007 118807B2

(12) United States Patent (10) Patent No.: US 7,118,807 B2 Maze et al. (45) Date of Patent: Oct. 10, 2006

(54) USE OF MOO, AS INHIBITOR, 3,827,140 A * 8/1974 Yamagishi et al...... 228/199 AND COMPOSITION 3,874,883 A * 4, 1975 Robitaille et al...... 106.1421 CONTAINING SUCH AN INHIBITOR 3,917,648 A * 1 1/1975 McLeod ...... 524/364

4.277,284 A * 7/1981 Ginsberg et al...... 106.1.05 (75) Inventors: Etienne Maze, Clermont (FR): Carmen 4,305,979 A * 12/1981 Isarai et al...... 427/386 Mocquery, Creil (FR); Benoit Millet, 4,731,295 A * 3/1988 Yamamoto et al...... 428,472 Saint Witz (FR); Antonio Francisco 5,993,523 A * 11/1999 Keemer et al...... 106.1421 Iandoli Espinosa, Sao Paulo (BR) 6,153,270 A 1 1/2000 Russmann et al. 6,270,884 B1* 8/2001 Guhde et al...... 428,323 (73) Assignee: Dacral, S.A., Creil (FR) 6,610.407 B1 8/2003 Homi ...... 428/416 (*) Notice: Subject to any disclaimer, the term of this patent is extended or adjusted under 35 U.S.C. 154(b) by 0 days. FOREIGN PATENT DOCUMENTS (21) Appl. No.: 11/312,320 CA 1182720 A * 2, 1985 EP 147273 A * 11, 1983 (22) Filed: Dec. 20, 2005 EP 174019 B1 3, 1999 (65) Prior Publication Data EP 987317 B1 6, 2002 GB 2091235 A * 7, 1982 US 2006/0188731 A1 Aug. 24, 2006 JP 05-044O90 A * 2/1993 Related U.S. Application Data JP O6100803 A * 7, 1994 JP 08-060039 A * 3, 1996 (63) Continuation of application No. 10/416,375, filed as WO WO 98.21382 A2 5, 1998 application No. PCT/IB01/02764 on Nov. 12, 2001. (30) Foreign Application Priority Data Nov. 13, 2000 (FR) ...... OO 14534 * cited by examiner Primary Examiner—Anthony J. Green (51) Int. Cl. (74) Attorney, Agent, or Firm Wood, Phillips, Katz, Clark B32B I5/04 (2006.01) & Mortimer B32B I5/00 (2006.01) C09D 5/08 (2006.01) (57) ABSTRACT C23F II/I-8 (2006.01) (52) U.S. Cl...... 428/469; 106/14.21; 106/1441: 106/14.44; 428/447; 428/450; 428/457; 428/472 The subject of the invention is the use of MoO, as a (58) Field of Classification Search ...... 106/14.21, corrosion inhibitor, and an anti-corrosion coating composi 106/1441, 14.44; 252/389.31, 389.54; 427/387: tion for parts, characterized in that it comprises:—at 428/447, 450, 457, 469, 472 least one particulate metal:—an organic solvent—a thick See application file for complete search history. ener—a silane-based binder, preferably carrying epoxy (56) References Cited functional groups: molybdenum (MoC)); possibly a silicate of sodium, potassium or lithium, and water. U.S. PATENT DOCUMENTS 3.248,251 A * 4, 1966 Allen ...... 428.559 24 Claims, 1 Drawing Sheet U.S. Patent Oct. 10, 2006 US 7,118,807 B2

SALT SPRAY RESISTANCE O ed Stability 4C (hours) 800 700 600 -- GEOMET-- 2%MoO3 500 -- GEOMET 400 300 200 00 O Age of the bath (weeks) O FIG.

SALT SPRAY RESISTANCE Og red rust Stability 20'C Chours) 700 600 500 -- GEOME -i- 400 -- GEOMET 300 200 100 Age of the bath (weeks)

FG.2 US 7,118,807 B2 1. 2 USE OF MOO, AS CORROSION INHIBITOR, According to one particular feature, the particulate AND COATING COMPOSITION have a lamellar form, the thickness of the flakes being CONTAINING SUCH AN INHIBITOR comprised between 0.05 um and 1 Lum and having a diameter equivalent (Ds) measured by laser diffraction comprised CROSS REFERENCE TO RELATED between 5um and 25 um the subject of the invention is more APPLICATION particularly the use of molybdenum oxide MoC) in a com position containing in aqueous phase. This application is a continuation of prior U.S. application According to another feature of the invention, the molyb Ser. No. 10/416,375 filed on May 12, 2003, which is a U.S. denum oxide MoC) is used in an essentially pure orthor National Stage of PCT/IB2001/02764 filed Nov. 12, 2001, 10 hombic crystalline form, having a molybdenum content which claims priority of FR 0014534 filed Nov. 13, 2000. greater than approximately 60% by mass. The object of the present invention is to develop an Advantageously, the molybdenum oxide MoC), will be anti-corrosion coating for metal parts, preferably a coating used in the anti-corrosion compositions in the form of free of hexavalent , which is endowed with particles having dimensions of between 1 and 200 um. improved anti-corrosion properties. 15 More specifically, the subject of the present invention is The invention applies to metal parts of any type, in anti-corrosion coating compositions for metal parts, which particular made of or cast iron, which need to have comprise: good corrosion behaviour, for example because of their application in the motor-vehicle industry. The geometry of at least one particulate metal; the parts to be treated is of little importance as long as the an organic solvent; anti-corrosion compositions may be applied by reliable and a thickener; industrializable processes. a silane-based binder, preferably carrying epoxy func One of the objects of the present invention is in particular tional groups; to improve the anti-corrosion properties of parts treated molybdenum oxide (MoC)); without using a composition based on hexavalent chromium 25 possibly a silicate of Sodium, potassium or lithium, and; in the formulation of the . Water. Many anti-corrosion treatment solutions based on hexava The relative proportions of the various constituents in lent chromium have been proposed to date. Although they Such a composition may vary widely. However, it has turned are generally satisfactory with regard to the protection of out that the content of molybdenum oxide MoC) is prefer treated metal parts, they are, however, becoming increas 30 ably between 0.5 and 7% and even more preferably in the ingly criticized because of their consequences with regard to region of 2% by weight of the total composition. the toxic risks that they entail and in particular because of The particulate metal present in the composition may be their adverse consequences for the environment. chosen from Zinc, , chromium, manganese, As a consequence, various anti-corrosion treatment com nickel, titanium, their alloys and intermetallic compounds, positions free of hexavalent chromium have been recom 35 and mixtures thereof. It should be pointed out here that if the mended. Some of these compositions are based on a par recommended coating composition is preferably free of ticular metal. Such as Zinc or aluminium. However, when Cr', it may nevertheless contain a certain proportion of Such compositions are in the form of an aqueous dispersion metallic chromium. In practice, it has turned out that the their stability is limited. This precludes long preservation presence of Zinc is highly desirable. and storage times. 40 Advantageously, the particulate metal content is between Within the context of the present invention, the Applicant 10% and 40% by weight of metal with respect to the weight has discovered that it is possible to improve the anti of the composition. corrosion properties and the stability of various anti-corro sion coating compositions by incorporating thereinto molyb Preferably, the anti-corrosion coating composition denum oxide MoC) as corrosion inhibitor. 45 according to the invention contains Zinc and/or aluminium, Hitherto, the use of molybdenum oxide MoC) as a cor and preferably comprises zinc. rosion inhibitor in Systems of aqueous phase has not been As indicated above, this type of composition is mainly of known. Certain molybdates, i.e. MoO, ions, have already aqueous nature and therefore preferably contains from 30% been presented as corrosion inhibitors. However, the Appli to 60% by weight of water. The composition may neverthe cant has been able to show that in a certain number of 50 less be enriched by the presence of an organic Solvent, conventional anti-corrosion compositions the addition of a preferably a water-soluble organic solvent, which makes it molybdate, for example Zinc molybdate, in no way improves possible to improve the anti-corrosion performance of the its properties. composition. For this purpose, the composition will contain, The present invention relates more particularly to the use for example, from 1% to 30% by weight with respect to the of molybdenum oxide MoC) as an agent for enhancing the 55 total composition. However, it seems to be important not to anti-corrosion properties of a coating composition based on exceed this organic solvent content of approximately 30%. a particulate metal containing Zinc or a Zinc alloy in aqueous In an advantageous embodiment of the invention, the phase. This finding has even been extended to composition composition will make use of an organic solvent, for containing hexavalent chromium. This is another object of example consisting of a glycol ether, in particular diethylene the invention. 60 glycol, triethylene glycol and dipropylene glycol. Without in any way wishing to be limited to such an According to another feature of the present invention, the interpretation, it seems that in the particular case of an anti-corrosion composition also contains from 0.005% to anti-corrosion coating composition based on a particulate 2% by weight of a thickening agent, in particular of a metal, the presence of molybdenum oxide MoC) makes it cellulose derivative, more particularly hydroxymethylcellu possible to improve the control of the sacrificial protection 65 lose, hydroxyethylcellulose, hydroxypropylcellulose, exerted by the particulate metal in Suspension in the com hydroxypropylmethylcellulose, Xanthan gum or an associa position. tive thickener of the polyurethane or acrylic type. US 7,118,807 B2 3 4 The composition of the present invention may also con tain mineral rheologic agents of the silica or organophilic -continued clays type. HEUCOPHOS (R) SRPP: hydrated strontium aluminium Such a composition also makes use of a binder, preferably polyphosphate (SrO: 28%; Al2O: 12%; an organofunctional silane, used in an amount of 3% to 20% P-Os: 42%) by weight. The organofunctionality can be represented by HEUCOPHOS (R) ZCP: hydrated Zinc calcium strontium vinyl, methacryloxy and amino, but is preferably epoxy silicate orthophosphate HEUCOPHOS (R) ZCPP: hydrated Zinc calcium aluminium functional for enhanced coating performance as well as strontium silicate orthophosphate composition stability. The silane is advantageously easily (ZnO: 37%; SrO: 5%: AlOs: 3%; P-Os: dispersible in aqueous medium, and is preferably soluble in 10 18%: CaO: 14%; SiO3: 14%) such medium. Preferably, the useful silane is an epoxy HEUCOPHOS (R CAPP: hydrated calcium aluminium silicate polyphosphate (Al2O: 7%; P-Os: 26%; functional silane Such as beta-(3.4-epoxycyclohexyl) ethyl CaO: 31%; SiO: 28%) trimethoxysilane, 4(trimethoxysilyl)butane-1,2 epoxide or Supplier: Devineau: y-glycidoxypropyl-trimethoxysilane. Finally, the anti-corrosion coating compositions accord 15 ACTIROX CR 213: Zinc iron phosphates (ZnO: 66%; PO: ing to the invention may also contain, in addition to the 48%; FeOs: 37%) aforementioned organic solvent, up to a maximum amount Supplier: Lawrence Industries: of approximately 10% by weight of white spirit so as to HALOX (R. SZP 391: Zinc calcium strontium improve the ability of the anti-corrosion compositions to be phosphosilicate applied to the metal parts by spraying, dipping or dip HALOX(R). CZ 170: Zinc orthophosphate spinning. Supplier: Tayca: Advantageously, the composition may also contain a K WHITE (R. 84: aluminium triphosphate (ZnO: 26.5 to silicate of sodium, potassium or lithium, preferably in an 30.5%; Al-Os: 9 to 13%; P-Os: 36 to 40%; SiO: 11 to 15%) amount comprised between 0.05% to 0.5% by weight. Molybdates Naturally, the present invention also relates to anti-cor 25 Supplier: Devineau: rosion coatings which are applied to the metal parts using the ACTIROX CR 102: Zinc molybdates coupled to aforementioned compositions, being applied by spraying, zinc-phosphate-modified agents (ZnO: spinning or dip-spinning followed by a curing operation at 63%; PO: 46%; MoC): 1%) a temperature of between 70° C. and 350° C. for a cure time ACTIROX CR 106: Zinc molybdates coupled to of around 30 minutes. 30 zinc-phosphate-modified agents (ZnO: According to an advantageous embodiment, the anti 67%; PO: 46%; MoC): 1%) corrosion coating will result from an application operation Supplier: Sherwin Williams: involving, prior to the curing operation, an operation of MOLY WHITE (R. MAZP: ZnO, CaCO, Zn(PO4)2, CaMoC) drying the coated metal parts, preferably at a temperature of MOLY WHITE (R. 212: ZnO, CaCO3, CaMoO. 35 Sodium molybdate: Na2MoC) around 70° C. for approximately 20 minutes. Under these Borates conditions, the thickness of the coating thus applied is Supplier: Buckman: between 3 um and 15 um and preferably between 5um and 10 um. BUTROL OR 23: calcium metaborate BUSAN (R) 11M2: barium metaborate BRIEF DESCRIPTION OF THE DRAWINGS 40 Supplier: Lawrence Industries:

HALOX(R) CW 2230: calcium borosilicate FIGS. 1 and 2, respectively, are graphs of salt spray Calcium-doped silica resistance, as a function of bath age, in the examples Supplier: Grace: presented herein below. In the examples presented herein below for comparative 45 SHIELDEX (RACS purposes, various types of corrosion inhibitor were tested Zinc salts within the context of the present study, which was carried Supplier: Henkel: out in order to improve the anti-corrosion properties of ALCOPHOR (R 827: organic Zinc salt various compositions and in particular of the reference Organic inhibitors composition called GEOMETR) which has been described in 50 Supp ier: Ciba-Geigy: U.S. Pat. No. 5,868,819 herein incorporated by reference. IRGACOR (R) 1930: complex of Zirconium and 4-methyl These were the main commercially available corrosion Y-oxobenzenebutanoic acid inhibitors. They have been listed below by broad chemical IRGACOR (R 1405: 4-oxo-4-p-tolybutyric acid with category, specifying each time the origin of the product 4-ethylmorpholine together with its name and its composition. 55 CGCI(R) (IRGACOR 287): polymeric amine salts Supplier: Lawrence Industries:

HALOXFLASH (R X: boric acid, phosphoric acid, Modified zinc phosphates: triethanolamine salts, 2-dimethyl Supplier: Heubach: aminoethanol 60 Zinc passivators HEUCOPHOS (R ZPA: hydrated Zinc aluminium Supplier: Ciba-Geigy: orthophosphate HEUCOPHOS (R) ZMP: hydrated zinc molybdenum IRGAMET OR 42: 2.2 (5-methyl-1H-benzotriazol orthophosphate 1-yl)methyliminobisethanol HEUCOPHOS (R) SAPP: hydrated strontium aluminium IRGAMET OR BTAM: 1H-benzotriazole. polyphosphate (SrO: 31%; Al2O: 12%; 65 POs: 44%; MgSiF6: 0.3%) US 7,118,807 B2 5 6 EXAMPLE 1. In addition, the more particular salt spray resistance results as a function of the age of the bath, and therefore of The standard reference GEOMETR) composition corre its stability at 4°C. and 20° C. respectively, are given in the sponds to: appended FIGS. 1 and 2. Both these figures show very clearly that, in each case, on the one hand, the anti-corrosion performance of the com position containing molybdenum oxide MoC) is markedly Deionized water 38.60% improved and that, on the other hand, the anti-corrosion DPG 10.29% performance is maintained better over time when molybde Boric acid 0.65% 10 SYMPERONIC (R) NP4 1.51% num oxide is added to the composition. SYMPERONIC (R) NP9 1.64% SILOUEST (R) A187 8.66% EXAMPLE 2 Zinc 32.12% Aluminium S.08% SCHWEGO FOAM (R) O.4% Two other types of comparative experiments were carried NIPAR (R) S10 O.71% 15 out, one on a GEOMETR) composition and the other on a AEROSOL (RTRFO O.S3% DACROMETR) composition based on hexavalent chro *Lamellar zinc in the form of an approximately 95% paste in white spirit: mium. zinc 31129/93 of ECKART WERKE; The formulations of these compositions are given in the **Lamellar aluminium in the form of an approximately 70% paste in tables below. DPG:CHROMAL VIII (R) of ECKART WERKE. To carry out the various comparative experiments on the TABLE 2 aforementioned inhibitors, different baths were obtained by adding 1 g of inhibitor to 9 ml of water, the dispersion being GEOMET (R) maintained for 1 hour, then the mixture was added to 90 g 25 Concentrations in Concentrations in of the aforementioned standard GEOMETR) composition Raw materials % without MoO. % with MoO. and then stirred for 3 hours. Deionized water 38.60 37.83 DPG 10.29 10.08 The first layer of this composition to be tested was applied Boric Acid O.65 O.64 using a No. 38 Conway bar. The drying was carried out at SYMPERONIC NP4 (R) 1.51 148 70° C. for approximately 20 minutes and then the curing was 30 SYMPERONIC NP9 (R) 1.64 1.61 SILOUEST (R) A187 8.66 8.47 carried out at 300° C. for approximately 30 minutes. Zinc 32.12 31.48 The second layer was applied using an identical protocol. Aluminium S.O8 4.98 SCHWEGO FOAM (R) 0.4 O.21 The panels thus treated were then tested in a salt spray. NIPAR (R) S10 O.71 O.70 The salt spray resistance results for the various coatings 35 AEROSOL (R TRAO O.S3 O.S2 tested are given in the table below. MoO,88: O 2 *Lamellar zinc in the form of an approximately 95% paste in white spirit: TABLE 1. Zinc 31129/93 of ECKART WERKE; **Lamellar aluminium in the form of an approximately 70% paste in Number of hours 40 DPG:CHROMAL VIII (R) of ECKART WERKE. Nature of the in Salt spray ***MoC): POR from CLIMAX Company inhibitor Name of the inhibitor without red rust SYMPERONIC (R): nonionic Surfactants SILQUEST (R) A187: Y-glycidoxypropyltrimethoxysilane Reference GEOMET 112 SCHWEGO FOAM (R): hydrocarbon-type antifoam Modified Zinc GEOMET + ZPA 134 NIPAR(R) S10: nitropropane phosphates GEOMET -- ZMP 122 AEROSOL (RTR70: anionic surfactant. GEOMET - SAPP 66 45 GEOMET - SRPP 66 GEOMET -- ZCP 66 TABLE 3 GEOMET -- ZCPP 88 GEOMET -- CAPP 66 DACROMET (R) GEOMET - ACTIROX 213 66 GEOMET -- HALOX 391 66 50 Concentrations in % Concentrations in % GEOMET -- K WHITE 84 88 Molybdates GEOMET + ACTIROX 102 66 Raw materials without MoO. with MoO. GEOMET - ACTIROX 106 88 Deionized water 47.86 44.90 GEOMET -- MW 212 88 DPG 15.95 15.63 GEOMET -- MW MZAP 88 PGME acetate 1.56 1.53 GEOMET + NaMoO, 66 55 Chromic acid 3.81 3.73 Borates GEOMET - BUTROL 44 REMCOPAL (R 334 0.72 O.71 GEOMET - BUSAN 112 REMCOPAL (R 339 0.72 O.71 GEOMET -- HALOX 2230 66 Zinc 23.61 23.14 Various GEOMET - SHIELDEX 112 Aluminium 3.06 3.00 GEOMET - ALCOPHOR 827 66 Boric acid 1.30 1.27 GEOMET -- IRGACOR 1930 88 60 ZnO 1.41 1.38 GEOMET -- IRGACOR 1405 88 MoO,88: O 2 GEOMET -- CGCI 88 GEOMET -- HALOXFLASH X 66 *Lamellar zinc in the form of an approximately 95% paste in white spirit: GEOMET -- IRGAMET 42 44 Zinc 31129/93 of ECKART WERKE; GEOMET -- IRGAMETBTAM 66 **Lamellar Aluminium in the form of an approximately 70% paste in Invention GEOMET + MoO* S18 DPG:CHROMAL VIII (R) of ECKART WERKE. 65 ***MoC): POR from CLIMAX Company * MoC): POR from CLIMAX Company REMCOPAL (R): nonionic surfactants. US 7,118,807 B2 7 8 It should be noted that the molybdenum oxide powder was each time introduced into the GEOMETR) or DAC TABLE 5-continued ROMETR) bath by dusting. The bath was homogenized by Composition Composition stirring using a dispersive blade at 450 revolutions per without silicate with silicate minute. (concentrations (concentrations The anti-corrosion compositions tested were applied to 10 Raw materials in %) in %) cmx20 cm cold rolled low carbon steel panels by coating NIPARS10 (R) 0.7 0.7 using the Conway bar, followed by predrying at 70° C. AEROSOL TRAO (R) O.S2 O.S2 during about 20 minutes, and then cured in an oven at 300° MoO. 1 1 C. for 30 minutes. 10 Silicate of sodium grade 42 O O.17 In the case of application to Screws, the compositions Xanthan gum (1) 0.7 0.7 were applied by dip-spinning and then cured under the same (1) Thickening agent in order to control the viscosity of the composition conditions as for the panels. during application The observed salt spray resistance results according to the 15 The composition is applied onto steel panels which have ISO 9227 standard are given schematically in the following previously been degreased, with a Conway rod, in order to table: obtain a weight of a coating layer of 30 g/m. The plates are then cured under the same conditions as previously TABLE 4 described. Salt spray resistance' They are then Submitted to the according to ISO 9227 and to the cohesion test. The results are shown in Coating Without With 2% PRODUCT SUBSTRATE weight** MoO. MoO. following Table 6. Aqueous Panels 32 288 >840 TABLE 6 GEOMET (R) 25 Aqueous Screws 30 144 SO4 Without With GEOMET (R) alkaline alkaline DACROMET (R) Screws 24 600 744 silicate silicate *Number of hours of exposure to salt spray before red rust appears. Salt spray 694 720 **grams per square meter of coated Surface, the thickness of the coatings (number of hours before are comprised between approximately about 6 m and about 8 m. 30 appearance of red rust) It is therefore apparent that introducing molybdenum Cohesion 1.5 5/5 oxide MoC) into compositions in aqueous phase, GEOMETR) or DACROMETR) containing particulate zinc, This table shows that even if the resistance to the cohesion improves the salt spray resistance of the said compositions is not significantly modified, the cohesion on the contrary, is very substantially. 35 highly improved. Another aspect of the invention consists in adding an The invention claimed is: alkaline silicate to the composition in an amount comprised 1. A coated metal Substrate protected with an anti-corro between 0.05% to 0.5% by weight. sion coating which coating is established on said Substrate The addition of alkaline silicate, for example sodium 40 by curing an applied aqueous anti-corrosion coating com silicate, Surprisingly enhances the film cohesion in a worthy position, wherein the coating composition comprises: way. at least one particulate metal; This is particularly illustrated in the following compara an organic solvent; tive example given in Table 5. a thickener; 45 a silane-based binder; EXAMPLE 3 molybdenum oxide; and Water. In this example, the cohesion is evaluated by applying a 2. The coated metal substrate of claim 1, wherein said transparent adhesive paper on the coating Surface and by coating composition contains from 0.5% to 7% by weight of quick pulling off. The cohesion is evaluated according to a 50 scale from 0 (complete pulling off of the coating film) to 5 the molybdenum oxide. 3. The coated metal substrate of claim 2, wherein said (no pulling off at all of the coating film). coating composition contains approximately 2% by weight TABLE 5 of the molybdenum oxide. 55 4. The coated metal substrate of claim 1, wherein said Composition Composition coating composition contains from 10% to 40% by weight of without silicate with silicate the at least one particulate metal. (concentrations (concentrations 5. The coated metal substrate of claim 1, wherein the at Raw materials in %) in %) least one particulate metal is chosen from lamellar Zinc Deionized water 38.13 37.96 and/or lamellar aluminum. Dipropylene glycol 10.08 10.08 60 Boric acid O.64 O.64 6. The coated metal substrate of claim 5, wherein said at Sympéronic NP4 (R) 1.48 148 least one particulate metal comprises lamellar zinc. Sympéronic NP9 (R) 1.61 1.61 7. The coated metal substrate of claim 1, wherein the Silane A187 (R) 8.47 8.47 Zinc 3112993 31.48 31.48 organic solvent is a glycolether. Aluminium CHROMAL VIII (R) 4.98 4.98 65 8. The coated metal substrate of claim 1, wherein the Schwegofoam (R) O.21 O.21 organic solvent is diethylene glycol, triethylene glycol, or dipropylene glycol. US 7,118,807 B2 10 9. The coated metal substrate of claim 1, wherein said 18. The coated metal substrate of claim 1, wherein said coating composition contains from 0.005% to 2% by weight coating composition contains approximately 30% to 60% by of the thickening agent. weight of water. 10. The coated metal substrate of claim 9, wherein said 19. The coated metal substrate of claim 1, wherein the thickening agent is a cellulose derivative. curing of said coating is done at a temperature of between 11. The coated metal substrate of claim 10, wherein said thickening agent is hydroxymethylcellulose, hydroxypropy 7O and 350° C. lcellulose, or hydroxypropylmethylcellulose. 20. The coated metal substrate of claim 1, wherein the 12. The coated metal substrate of claim 9, wherein said curing of said coating lasts approximately 30 minutes. thickening agent is Xanthan gum or a polyurethane or acrylic 10 21. The coated metal substrate of claim 1, wherein said thickener. coating is established by curing an applied coating compo 13. The coated metal substrate of claim 1, wherein said sition which is Subjected to a drying operation after being coating composition contains from 3% to 20% by weight of applied and before being Subjected to the curing. silane, as the silane based binder. 22. The coated metal substrate of claim 21, wherein said 14. The coated metal substrate of claim 13, wherein the 15 coating composition is subjected to the drying operation at silane comprises Y-glycidoxypropyltrimethoxysilane. a temperature of approximately 70° C. for approximately 20 15. The coated metal substrate of claim 1, wherein the minutes. silane based binder carries epoxy functional groups. 16. The coated metal substrate of claim 1, wherein the 23. The coated metal substrate of claim 1, wherein said organic solvent contains up to approximately 10% by weight 20 coating is applied with a thickness of between 3 and 15um. of white spirit. 24. The coated metal substrate of claim 23, wherein the 17. The coated metal substrate of claim 1, wherein said coating is applied with a thickness of between 5 and 10 Lum. coating composition further comprises a silicate of Sodium, potassium, or lithium.