Process for coating metallic surfaces with a silane-rich composition

Abstract

A method for coating a metallic surface with an aqueous composition for pretreating before applying another coating or for treating said metallic surface. In addition to water, the composition contains a) at least one hydrolysable or at least partially hydrolyzed silane; b) at least one metal chelate, if necessary, also c) at least one organic film former, d) at least one long-chain alcohol that serves as a film forming aid or e) at least one inorganic compound in particle form.

1 - 43 . (canceled) 
     
     
         44 . A process for coating a metallic surface with an aqueous composition, which can be largely or completely free from chromium (VI) compounds, for pretreatment before a further coating or for treatment, wherein the metallic surface is at least one of clean, pickled, cleaned or pretreated, comprising contacting said metallic surface with the aqueous composition and forming a film on the metallic surface; and
 drying and optionally curing the film;
 wherein the dried and optionally cured film has a layer thickness in the range from 0.01 to 10 μm 
   wherein the aqueous composition comprises water and   a) at least one of a hydrolyzable or at least partly hydrolyzed silane;   b) at least one alkali metal lactate;   c) at least one organic film-forming agent which contains at least one of a water-soluble or water-dispersed organic polymer or copolymer with an acid number in the range from 3 to 250, wherein the content of organic film-forming agent, based on the solids content, is from 10 to 45 wt. %; and   d) optionally at least one long-chain alcohol as a film-forming auxiliary;   wherein the aqueous composition is free of Ti/Zr hexafluoride.   
     
     
         45 . A process for coating a metallic surface with an aqueous composition, which can be largely or completely free from chromium (VI) compounds, for pretreatment before a further coating or for treatment, wherein the metallic surface is at least one of clean, pickled, cleaned or pretreated, comprising contacting said metallic surface with the aqueous composition and forming a film on the metallic surface; and
 drying and optionally curing the film;
 wherein the dried and optionally cured film has a layer thickness in the range from 0.01 to 10 μm 
   wherein the aqueous composition comprises water and   a) at least one of a hydrolyzable or at least partly hydrolyzed silane;   b) at least one chelate selected from the group consisting of alkali metal lactate, ammonium lactate, a citrate, a dialkyl citrate and a dialkylester citrate;   c) at least one organic film-forming agent which contains at least one of a water-soluble or water-dispersed organic polymer or copolymer with an acid number in the range from 3 to 250, wherein the content of organic film-forming agent, based on the solids content, is from 10 to 45 wt. %; and   d) optionally at least one long-chain alcohol as a film-forming auxiliary;   wherein the aqueous composition is free of Ti/Zr hexafluoride.   
     
     
         46 . The process according to  claim 45 , wherein the aqueous composition further comprises at least one component e) selected from the group consisting of
 e 1 ) at least one inorganic compound in particle form with an average particle diameter, measured on a scanning electron microscope, in the range from 0.005 to 0.3 μm diameter,   e2) at least one lubricant,   e3) at least one organic corrosion inhibitor,   e4) at least one anticorrosion pigment,   e5) at least one agent for neutralization or/and for steric stabilization of the synthetic resins,   e6) at least one organic solvent,   e7) at least one siloxane and   e8) at least one chromium (VI) compound.   
     
     
         47 . The process according  claim 45 , wherein the organic film-forming agent is a synthetic resin mixture of at least one polymer, at least one copolymer which comprises a content of synthetic resin based on acrylate, epoxide, ethylene, urea-formaldehyde, phenol, polyester, polyurethane, styrene, styrene-butadiene or vinyl. 
     
     
         48 . The process  claim 45 , wherein the organic film-forming agent comprises a synthetic resin having a content of an organic polymer, a copolymer or mixtures thereof based on at least one of polyethyleneimine, polyvinyl alcohol, polyvinylphenol, polyvinylpyrrolidone or polyaspartic acid. 
     
     
         49 . The process  claim 45 , wherein the organic film-forming agent contains a content of at least one copolymer with an acid number in the range from 3 to 80, to the extent of at least 50 wt. % of the synthetic resins added. 
     
     
         50 . The process  claim 45 , wherein the organic film-forming agent contains at least one component based on at least one of
 acrylic-polyester-polyurethane copolymer,   acrylic-polyester-polyurethane-styrene copolymer,   acrylic acid ester,   acrylic acid ester-methacrylic acid ester, optionally with free acids or/and acrylonitrile,   ethylene-acrylic mixture,   ethylene-acrylic copolymer,   ethylene-acrylic-polyester copolymer,   ethylene-acrylic-polyurethane copolymer,   ethylene-acrylic-polyester-polyurethane copolymer,   ethylene-acrylic-polyester-polyurethane-styrene copolymer,   ethylene-acrylic-styrene copolymer,   polyester resins with free carboxyl groups combined with melamine-formaldehyde resins,   a synthetic resin mixture or a copolymer based on acrylate and styrene, a synthetic resin mixture or a copolymer based on styrene-butadiene,   a synthetic resin mixture or a copolymer of acrylate and epoxide,   based on an acrylic-modified polyester containing carboxyl groups together with melamine-formaldehyde and ethylene-acrylic copolymer, polycarbonate-polyurethane,   polyester-polyurethane,   styrene,   styrene-vinyl acetate,   vinyl acetate, vinyl ester or   vinyl ether.   
     
     
         51 . The process  claim 45 , wherein at least 30 wt. % of the organic film-forming agent added comprises film-formable thermoplastic resins. 
     
     
         52 . The process  claim 45 , wherein the molecular weights of synthetic resins in the aqueous composition added are in the range of at least 1,000 u. 
     
     
         53 . The process  claim 45 , wherein the organic film-forming agents added comprise at least 40 wt. % of high molecular-weight polymers. 
     
     
         54 . The process  claim 45 , wherein the organic film-forming agents comprise synthetic resins, wherein acid groups of synthetic resins are stabilized with ammonia, an amine or an alkali metal compound. 
     
     
         55 . The process  claim 45 , wherein the aqueous composition contains 0.1 to 980 g/l of the organic film-forming agent. 
     
     
         56 . The process  claim 45 , wherein the aqueous composition contains an acyloxysilane, an alkoxysilane, a silane with at least one amino group, a silane with a succinic acid group or a succinic acid anhydride group, a bis-silyl-silane, a silane with at least one epoxide group, a (meth)acrylato-silane, a multi-silyl-silane, an ureidosilane, a vinylsilane, a silanol or a siloxane having a composition which corresponds thereto. 
     
     
         57 . The process  claim 45 , wherein the aqueous composition contains at least one silane selected from the group consisting of
 glycidoxyalkyltrialkoxysilane,   methacryloxyalkyltrialkoxysilane,   (trialkoxysilyl)alkyl-succinic acid-silane,   aminoalkylaminoalkylalkyldialkoxysilane,   (epoxycycloalkyl)alkyltrialkoxysilane,   bis-(trialkoxysilylalkyl)amine,   bis-(trialkoxysilypethane,   (epoxyalkyl)trialkoxysilane,   aminoalkyltrialkoxysilane,   ureidoalkyltrialkoxysilane,   N-(trialkoxysilylalkyl)alkylenediamine,   N-(aminoalkyl)aminoalkyltrialkoxysilane,   N-(trialkoxysilylalkyl)dialkylenetriamine, poly(aminoalkyl)alkyldialkoxysilane,   tris(trialkoxysilyl)alkyl isocyanurate,   ureidoalkyltrialkoxysilane and   acetoxysilane.   
     
     
         58 . The process  claim 45 , wherein the aqueous composition contains at least one silane selected from the group consisting of
 3-glycidoxypropyltriethoxysilane,   3-glycidoxypropyltrimethoxysilane,   3-methacryloxypropyltriethoxysilane,   3-methacryloxypropyltrimethoxysilane,   3-(triethoxysilyl)propyl-succinic acid-silane,   aminoethylaminopropylmethyldiethoxysilane   aminoethylaminopropylmethyldimethoxysilane,   beta-(3,4-epoxycyclohexyl)ethyltriethoxysilane,   beta-(3,4-epoxycyclohexyl)ethyltrimethoxysilane,   beta-(3,4-epoxycyclohexyl)methyltriethoxysilane,   beta-(3,4-epoxycyclohexyl)methyltrimethoxysilane,   gamma-(3,4-epoxycyclohexyl)propyltriethoxysilane,   gamma-(3,4-epoxycyclohexyl)propyltrimethoxysilane,   bis(triethoxysilylpropyl)amine,   bis(trimethoxysilylpropyl)amine,   (3,4-epoxybutyl)triethoxysilane,   (3,4-epoxybutyl)trimethoxysilane,   gamma-aminopropyltriethoxysilane,   gamma-aminopropyltrimethoxysilane,   gamma-ureidopropyltrialkoxysilane,   N-(3-(trimethoxysilyl)propyl)ethylenediamine,   N-beta-(aminoethyl)-gamma-aminopropyltriethoxy-silane,   N-beta-(aminoethyl)-gamma-aminopropyltrimethoxysilane,   N-(gamma-triethoxysilylpropyl)diethylenetriamine,   N-(gamma-trimethoxysilylpropyl)diethylene-triamine,   N-(gamma-triethoxysilylpropyl)dimethylene-triamine,   N-(gamma-trimethoxysilylpropyl)dimethylene-triamine,   poly(aminoalkyl)ethyldialkoxysilane,   poly(aminoalkyl)methyldialkoxysilane,   tris(3-(triethoxysilyl)propyl)isocyanurate   tris(3-(trimethoxysilyl)propyl)isocyanurate and   vinyltriacetoxysilane.   
     
     
         59 . The process  claim 45 , wherein the content of the at least one silane in the aqueous composition, including the reaction products formed therefrom, is from 0.1 to 50 g/l. 
     
     
         60 . The process  claim 45 , wherein the at least one metal chelate is selected from chelate complexes based on acetylacetonates, acetoacetates, acetonates, alkylenediamines, amines, lactates, carboxylic acids, citrates or glycols, the content of the at least one chelate in the aqueous composition, and any reaction products formed therefrom. 
     
     
         61 . The process  claim 45 , wherein the at least one metal chelate is analkali metal lactate. 
     
     
         62 . The process  claim 45 , wherein a finely divided powder, a dispersion or a suspension is added as inorganic compound in particle form. 
     
     
         63 . The process  claim 45 , wherein the inorganic compound in particle form comprising at least one compound of aluminum, barium, cerium, calcium, lanthanum, silicon, titanium, yttrium, zinc or zirconium. 
     
     
         64 . The process  claim 45 , wherein particles based on at least one of aluminum oxide, barium sulfate, cerium dioxide, silicon dioxide, silicate, titanium oxide, yttrium oxide, zinc oxide or zirconium oxide are added to the aqueous composition as an inorganic compound in particle form. 
     
     
         65 . The process  claim 45 , wherein the aqueous composition contains 0.1 to 500 g/l of the at least one inorganic compound in particle form. 
     
     
         66 . The process  claim 45 , wherein the aqueous composition contains at least one organic corrosion inhibitor based on an amine, a TPA-amine complex, an alkylaminoethanol, a zinc salt of aminocarboxylate, a zinc salt of 5-nitro-isophthalic acid, a zinc salt of cyanic acid, a polymeric amino salt with fatty acid, a metal salt of a sulfonic acid, at least one amino and transition metal complex of toluenepropionic acid, 2-mercapto-benzothiazolyl-succinic acid or an ammonium salt thereof a conductive polymer, or a thiol, wherein the content of organic corrosion inhibitor in the aqueous composition is in the range from 0.01 to 5 wt. %. 
     
     
         67 . The process  claim 45 , wherein the aqueous composition contains at least one basic crosslinking agent based on at least one of titanium, hafnium or zirconium as a cation, a carbonate or ammonium carbonate as an anion, and wherein the content of such crosslinking agents in the aqueous composition is in the range of from 0.01 to 3 wt. %. 
     
     
         68 . The process  claim 45 , wherein no inorganic acids or organic carboxylic acids are added to the aqueous composition. 
     
     
         69 . The process  claim 45 , wherein the film forming auxiliary is at least one long-chain alcohol selected from the group consisting of a diol, a butyl glycol a butyl diglycol, an esteralcohol, an ethylene glycol, an ethylene glycol ether a glycol ether, a polyether a polyethylene glycol, a polyethylene glycol ether, a polyglycol, a polypropylene glycol, a propylene glycol, a propylene glycol ether, a polypropylene glycol ether, a glycol ether, trimethylpentanediol diisobutyrate or a derivative thereof, wherein the content of long-chain alcohol in the aqueous composition is in the range from 0.01 to 10 wt. %. 
     
     
         70 . The process  claim 45 , wherein at least one wax selected from the group consisting of paraffins, polyethylenes and polypropylenes, is present as the lubricant, wherein the content of waxes in the aqueous composition is in the range from 0.01 to 5 wt. %. 
     
     
         71 . The process  claim 45 , wherein the aqueous composition comprises a lubricant, said lubricant comprising wax together with a polymer mixture or a copolymer, said polymer or copolymer comprising ethylene and acrylic acid as the lubricant. 
     
     
         72 . The process  claim 45 , wherein the film is cured partly by drying and film formation and partly by actinic radiation, cationic polymerization or/and thermal crosslinking. 
     
     
         73 . The process  claim 45 , wherein the aqueous composition contains at least one additive selected from the group consisting a biocide, a defoamer or a wetting agent. 
     
     
         74 . The process  claim 45 , wherein the aqueous composition is applied to the metallic surface at a temperature in the range from 5 to 50° C. 
     
     
         75 . The process  claim 45 , wherein the metallic surface is kept at temperatures in the range from 5 to 60° C. during application of the film coating. 
     
     
         76 . The process  claim 45 , wherein the coated metallic surface is dried at a temperature in the range from 20 to 400° C. 
     
     
         77 . The process  claim 45 , wherein coated surface is on a strip is wound up to a coil, optionally after cooling to a temperature in the range from 40 to 70° C. 
     
     
         78 . The process  claim 45 , wherein the aqueous composition is applied by rolling on, flooding, knife-coating on, spraying, misting, brushing or dipping and optionally by subsequent squeezing off with a roller. 
     
     
         79 . The process  claim 45 , wherein the dried and optionally also cured film has a pendulum hardness of 30 to 190 s, measured with a König pendulum hardness tester in accordance with DIN 53157. 
     
     
         80 . The process  claim 45 , wherein the dried and optionally also cured film has a flexibility such that on bending over a conical mandrel in a mandrel flex test substantially in accordance with DIN ISO 6860 for a mandrel of 3.2 mm to 38 mm but without tearing the test area longer than 2 mm that are detectable on subsequent wetting with copper sulfate by a change in color due to deposition of copper on the torn-open metallic surface are formed. 
     
     
         81 . The process  claim 45 , wherein at least one coating of printing ink, foil, lacquer, lacquer-like material, powder coating, adhesive or/and adhesive carrier is applied to the dried and optionally also cured film. 
     
     
         82 . The process  claim 45 , wherein metal surface is on metal components, strips or strip sections, and wherein the resultant coated metal components, strips or strip sections are shaped, lacquered, coated with a polymer printed, glued, hot-soldered, welded or joined to one another or to other elements by clinching or other joining techniques. 
     
     
         83 . An aqueous composition for pretreatment of a metallic surface before a further coating or for treatment of that surface, wherein the composition comprises water and
 a) at least one hydrolyzable or at least partly hydrolyzed silane,   b) at least one chelate selected from the group consisting of alkali metal lactate, ammonium lactate, a citrate, a dialkyl citrate and a dialkylester citrate;   c) at least one organic film-forming agent which contains at least one water-soluble or water dispersed organic polymer or copolymer with an acid number in the range from 3 to 250, the content of organic film-forming agent, based on the solids content, being 10 to 45 wt. %, and   d) optionally at least one long-chain alcohol as a film-forming auxiliary,
 wherein the amounts ratio of a) to b), in each case including the reaction products formed therefrom, is in the range from 0.1:1 to 10:1; 
   wherein the aqueous composition is free of Ti/Zr hexafluoride.   
     
     
         84 . The aqueous composition according to  claim 45 , wherein the composition also contains at least one inorganic compound in particle form. 
     
     
         85 . A substrate coated by the process according to  claim 45 , wherein the substrate is a wire, strip, sheet metal or a component for a wire coil, a wire braid, a steel strip, a metal sheet, a lining, a screen, a vehicle body or a component of a vehicle body, a component of a vehicle, trailer, mobile home or missile, a cover, a housing, a lamp, a light, a traffic light element, a piece of furniture or furniture element, an element of a domestic appliance, a frame, a profile, a shaped component of complicated geometry, a crash barrier, heater or fence element, a bumper, a component of or with at least one tube or a profile, a window, door or bicycle frame or an item of hardware or a spectacle frame. 
     
     
         86 . The process of  claim 45 , wherein the organic film-forming agent contains at least two component based on at least one of
 acrylic-polyester-polyurethane copolymer,   acrylic-polyester-polyurethane-styrene copolymer,   acrylic acid ester,   acrylic acid ester-methacrylic acid ester, optionally with free acids or/and acrylonitrile,   ethylene-acrylic mixture,   ethylene-acrylic copolymer,   ethylene-acrylic-polyester copolymer,   ethylene-acrylic-polyurethane copolymer,   ethylene-acrylic-polyester-polyurethane copolymer,   ethylene-acrylic-polyester-polyurethane-styrene copolymer,   ethylene-acrylic-styrene copolymer,   polyester resins with free carboxyl groups combined with melamine-formaldehyde resins,   at least one of a synthetic resin mixture or copolymer based on acrylate and styrene,   at least one of a synthetic resin mixture or copolymer based on styrene-butadiene,   at least one of a synthetic resin mixture or copolymer of acrylate and epoxide,   based on an acrylic-modified polyester containing carboxyl groups together with melamine-formaldehyde and ethylene-acrylic copolymer, polycarbonate-polyurethane,   polyester-polyurethane,   styrene,   styrene-vinyl acetate,   vinyl acetate,   vinyl ester or   vinyl ether.   
     
     
         87 . The process of  claim 45 , wherein the organic film-forming agents comprise synthetic resins. 
     
     
         88 . A process for coating a metallic surface with an aqueous composition, which can be largely or completely free from chromium (VI) compounds, for pretreatment before a further coating or for treatment, wherein the metallic surface is at least one of clean, pickled, cleaned or pretreated, comprising contacting said metallic surface with the aqueous composition and forming a film on the metallic surface; and
 drying the film;
 wherein the dried film has a layer thickness in the range from 0.01 to 10 μm 
   wherein the aqueous composition comprises water and   a) at least one of an hydrolyzable or at least partly hydrolyzed silane;   b) at least one chelate selected from the group consisting of alkali metal lactate, ammonium lactate, a citrate, a dialkyl citrate and a dialkylester citrate;   c) at least one organic film-forming agent having an acid number in the range from 3 to 250, wherein the organic film-forming agent, based on the solids content, is present in an amount of from 10 to 45 wt. % and is water soluble or water dispersible; and   d) at least one long-chain alcohol as a film-forming auxiliary;   wherein the aqueous composition is free of Ti/Zr hexafluoride.   
     
     
         89 . The process of  claim 87 , wherein the aqueous composition further comprises at least one component selected from the group consisting of an inorganic compound in particle form with an average particle diameter measured on a scanning electron microscope in the range from 0.005 to 0.3 μm diameter, a lubricant, an organic corrosion inhibitor, an anticorrosion pigment, and an organic solvent. 
     
     
         90 . The process of  claim 45 , wherein the inorganic compound in particle form comprising at least one compound of aluminum, barium, cerium, calcium, lanthanum, silicon, yttrium, or zinc. 
     
     
         91 . The process of  claim 45 , wherein particles based on at least one of aluminum oxide, barium sulfate, cerium dioxide, silicon dioxide, silicate, yttrium oxide, or zinc oxide are added to the aqueous composition as an inorganic compound in particle form. 
     
     
         92 . The process of  claim 87 , wherein the inorganic compound in particle form comprising at least one compound of aluminum, barium, cerium, calcium, lanthanum, silicon, yttrium, or zinc. 
     
     
         93 . The process of  claim 87 , wherein particles based on at least one of aluminum oxide, barium sulfate, cerium dioxide, silicon dioxide, silicate, yttrium oxide, or zinc oxide are added to the aqueous composition as an inorganic compound in particle form. 
     
     
         94 . An aqueous composition for pretreatment of a metallic surface before a further coating or for treatment of that surface, wherein the composition has a solids content and comprises water and
 a) at least one hydrolyzable or at least partly hydrolyzed silane,   b) at least one chelate selected from the group consisting of alkali metal lactate, ammonium lactate, a citrate, a dialkyl citrate and a dialkylester citrate;   c) at least one water-soluble or water dispersed organic polymer or copolymer with an acid number in the range from 3 to 250, the content of organic film-forming agent, based on the solids content, being 10 to 45 wt. %, and   wherein the ratio of a) to b) including the reaction products formed therefrom, ranges from 0.1:1 to 10:1;   wherein the aqueous composition is free of Ti/Zr hexafluoride.   
     
     
         95 . The process of  claim 45 , wherein the pH of the aqueous composition is 6 to 10.5. 
     
     
         96 . The aqueous composition according to  claim 83 , wherein the pH of the aqueous composition is 6 to 10.5. 
     
     
         97 . The aqueous composition according to  claim 93 , wherein the pH of the aqueous composition is 6 to 10.5. 
     
     
         98 . The process of  claim 45 , wherein the ratio of silane content to chelate content is 0.2:1 to 5:1. 
     
     
         99 . The aqueous composition of  claim 83 , wherein the ratio of silane content to chelate content is 0.2:1 to 5:1. 
     
     
         100 . The aqueous composition of  claim 93 , wherein the ratio of silane content to chelate content is 0.2:1 to 5:1. 
     
     
         101 . The process of  claim 94 , wherein the ratio of silane content to chelate content is 0.2:1 to 5:1. 
     
     
         102 . The aqueous composition of  claim 96 , wherein the ratio of silane content to chelate content is 0.2:1 to 5:1. 
     
     
         103 . The aqueous composition of  claim 97 , wherein the ratio of silane content to chelate content is 0.2:1 to 5:1.