Coagulation coating process

Claim 2

A process for coating a substrate comprising: (A) providing said substrate with a surface coating of a dry coagulating compound; and (B) exposing said coated substrate to an aqueous composition which, except for solvents, reactive and nonreactive pigments and other nonreactive particulate material, consists essentially of an organic film-forming material consisting essentially of (i) at least fifty (50) weight percent of a chemically ionizable, organic film-former which (a) has at least 12 carbon atoms per molecule, (b) is at least partially ionized such that it is substantially soluble in said aqueous composition, and (c) coagulates in the presence of said coagulating compound; and (ii) a remainder of an organic film-former which is not chemically ionizable.

Claim 3

A process in accordance with claim 1, wherein said coagulating compound is selected from the group consisting of (i) bases having a pH greater than 10, (ii) basic salts, and (iii) mixtures of (i) and (ii), and said organic film-former is selected from basic monomers and resins having one or more nitrogens in their molecular structure and is at least partially neutralized by a water soluble acid compound.

Claim 4

A process in accordance with claim 2 wherein said basic salts are selected from the group consisting of carbonates, silicates, oxalates, salicylates and formates of alkali earth metals.

Claim 5

A process in accordance with claim 2 wherein said bases are alkali earth metal hydroxides.

Claim 6

A process in accordance with claim 1, wherein the concentration of organic film-forming material in said aqueous composition is maintained in the range of about 0.2 to about 40 weight percent and said composition includes particulate material which is (i) codeposited with said organic film-forming material and (ii) present in said composition in an amount such that the weight ratio of particulate material to organic film-forming material in said composition is in the range of 1:9 to 30:1.

Claim 7

A process in accordance with claim 5 wherein said substrate and said particulate material are both metal, said particulate material being present in said bath such that the weight ratio of metal particles to organic film-forming material is in the range of 1:1 to 20:1.

Claim 8

A process in accordance with claim 6 wherein said substrate is heated, after said organic film-forming material and metal particles are codeposited thereon, in an ambient essentially inert to the metal particles and said coating to a decomposition temperature above the temperature required to decompose the organic film-forming material in said coating and below the diffusion temperature for said particles, maintaining said decomposition temperature until said coating is essentially decomposed and gaseous products thereof are formed in the heating zone, essentially evacuating said gaseous products from said heating zone, maintaining said substrate in said heating zone in an ambient essentially inert to the metal particles and raising the temperature of said heating zone to the diffusion temperature of the metal, and maintaining said diffusion temperature and said ambient for a time necessary to effect the desired diffusion coating.

Claim 9

A process in accordance with claim 5 wherein said particulate material is selected from the group consisting of ceramic frit, metal particles and mixtures thereof and is present in such an amount that the particulate material to organic film-forming material weight ratio is in the range of 1:1 to 20:1.

Claim 10

A process in accordance with claim 8 wherein said substrate is heated after said organic film-forming material and said particulate material are codeposited, to a temperature sufficient to vaporize said organic film-forming material.

Claim 11

A process in accordance with claim 9 wherein said particulate material is ceramic frit and said substrate is heated after vaporization of said organic film-forming material to a temperature for a time sufficient to unitize said ceramic frit on the surface of said substrate.

Claim 12

A process in accordance with claim 1, wherein said coagulating compound is a metal salt having a pH of less than 7.0 and said organic film-former is a polycarboxylic acid resin which is at least partially neutralized with a water soluble base.

Claim 13

A process in accordance with claim 11, wherein said polycarboxylic acid resin is synthetic and has (i) an electrical equivalent weight between about 1,000 and about 20,000, and (ii) an acid number between about 30 and about 300.

Claim 14

A process in accordance with claim 11, wherein said metal salt is a salt of a First Transition Series metal.

Claim 15

A process in accordance with claim 11, wherein said salt has a pH of between about 3.5 and about 4.5 and is selected from the group consisting of nickel chloride, cupric chloride, cobaltous chloride, cupric nitrate, nickel nitrate, cupric sulfate, zinc chloride and mixtures thereof.

Claim 16

A process in accordance with claim 11, wherein said substrate is a metal and said salt is formed at least in part by treating said substrate with an acid.

Claim 17

A process in accordance with claim 11, wherein said metal salt is nickel chloride, said organic film-former is included in said aqueous composition in a concentration of between about 0.2 and about 40 weight percent, and said chemically ionizable organic film-former consists essentially of a synthetic polycarboxylic acid resin which (i) has an electrical equivalent weight between about 1,000 and about 20,000, (ii) has an acid number between about 30 and about 300, (iii) is prepared by coupling a linseed oil with maleic anhydride, and (iv) is at least partially neutralized with a water soluble amine.

Claim 18

A process in accordance with claim 16, wherein said aqueous composition includes particulate material which is (i) codeposited with said organic film-forming material and (ii) present in said composition in an amount such that the weight ratio of particulate material to organic film-forming material in said composition is in the range of 1:9 to 30:1.

Claim 19

A process in accordance with claim 17, wherein said particulate material is selected from the group consisting of ceramic frit, metal particles and mixtures thereof and is present in such an amount that the particulate material to organic film-forming material weight ratio is in the range of 1:1 to 20:1.

Claim 20

A process in accordance with claim 18, wherein said substrate is heated after said organic film-forming material and said particulate material are codeposited, to a temperature sufficient to vaporize said organic film-forming material.

Claim 21

A process in accordance with claim 19, wherein said particulate material in ceramic frit and said substrate is heated after vaporization of said organic film-forming material to a temperature for a time sufficient to unitize said ceramic frit on the surface of said substrate.

Claim 22

A process in accordance with claim 17, wherein said substrate and said particulate material are both metal, said particulate material being present in said aqueous composition such that the weight ratio of metal particles to organic film-forming material is in the range of 1:1 to 20:1.

Claim 23

A process in accordance with claim 21, wherein said substrate is heated, after said organic film-forming material and metal particles are codeposited thereon, in an ambient essentially inert to the metal particles and said coating to a decomposition temperature above the temperature required to decompose the organic film-forming material in said coating and below the diffusion temperature for said particles, maintaining said decomposition temperature until said coating is essentially decomposed and gaseous products thereof are formed in the heating zone, essentially evacuating said gaseous products from said heating zone, maintaining said substrate in said heating zone in an ambient essentially inert to the metal particles and raising the temperature of said heating zone to the diffusion temperature of the metal, and maintaining said diffusion temperature and said ambient for a time necessary to effect the desired diffusion coating.

Claim 24

A process for coating a substrate comprising: (A) providing said substrate with a surface coating of a dry coagulating compound; and (B) immersing said coated substrate in an aqueous bath which, except for solvent, consists essentially of: (1) between about 0.2 and about 40 weight percent based on the total weight of the bath of an organic film-forming material consisting essentially of (a) at least about fifty (50) weight percent of a chemically ionizable, organic film-former which (i) has at least 12 carbon atoms per molecule, (ii) is at least partially ionized such that it is substantially soluble in said aqueous bath, and (iii) coagulates and deposits on said substrate in the presence of said coagulating compound, and (b) a remainder of an organic film-former which is not chemically ionizable; and (2) particulate material which is (a) codeposited with said organic film-forming material, and (b) present in said aqueous bath in an amount such that the weight ratio of particulate material to organic film-forming material in said bath is in the range of 1:9 to 30:1.

Claim 25

A process for coating a substrate comprising: (A) providing said substrate with a surface coating of a dry coagulating compound; and (B) immersing said coated substrate in an aqueous bath which, except for solvent, consists essentially of: (1) between about 0.2 and about 40 weight percent based on the total weight of the bath of an organic film-forming material consisting essentially of (a) at least about fifty (50) weight percent of a chemically ionizable, organic film-former which (i) has at least 12 carbon atoms per molecule, (ii) is at least partially ionized such that it is substantially soluble in said aqueous bath, and (iii) coagulates and deposits on said substrate in the presence of said coagulating compound, and (b) a remainder of an organic film-former which is not chemically ionizable; and (2) particulate material which is (a) codeposited with said organic film-forming material, and (b) present in said aqueous bath in an amount such that the weight ratio of particulate material to organic film-forming material in said bath is in the range of 1:9 to 30:1.

Claim 26

A process in accordance with claim 23, wherein said coagulating compound is a metal salt having a pH of less than 7.0 and said organic film-former is a polycarboxylic resin which is at least partially neutralized with a water soluble base.

Claim 27

A process in accordance with claim 24, wherein said polycarboxylic acid resin is synthetic and has (i) an electrical equivalent weight between about 1,000 and about 20,000, and (ii) an acid number between about 30 and about 300.

Claim 28

A process in accordance with claim 24 wherein said salt is selected from the group consisting of nickel chloride, cupric chloride, cobaltous chloride, cupric nitrate, nickel nitrate, cupric sulfate, zinc chloride and mixtures thereof.

Claim 29

A process in accordance with claim 23, wherein said coagulating compound is selected from the group consisting of (i) bases having a pH greater than 10, (ii) basic salts, and (iii) mixtures of (i) and (ii), and said organic film-former is selected from basic monomers and resins having one or more nitrogens in their molecular structure and is at least partially neutralized by a water soluble acid compound.

Claim 30

A process for modifying the surface of a metal substrate of which the major component by weight is selected from cobalt, nickel and iron and constitutes at least 40 weight percent of said substrate, said process comprising (a) providing said substrate with a surface coating of a dry coagulating compound, (b) codepositing by coagulation on said metal substrate a coating of (I) metal particles having an average diameter in the range of 0.5 to 20 microns and selected from (A) aluminum comprising particles wherein the weight ratio of aluminum to other metal is in the range of 200:1 to 1:3 and which are selected from (1) aluminum alloy particles, (2) a mixture of aluminum particles and particles of at least one other metal, (3) a mixture of aluminum particles and particles of at least one metal oxide, and (4) a mixture of aluminum particles and particles of at least one alloy, or (B) aluminum particles; and (II) a heat fugitive organic film-forming material consisting essentially of at least 50 weight percent of a chemically ionizable, organic film-former having at least 12 carbon atoms per molecule and a remainder of organic film-former which is not chemically ionizable, in a metal particle to organic film-forming material weight ratio in excess of 3:1, from an aqueous dispersion forming a coating bath which, except for solvent, consists essentially of said metal particles and said organic film-forming material, said chemically ionizable organic film-former being at least partically ionized and adapted to coagulate and deposit in the presence of said coagulating compound, and wherein (A) the weight ratio of metal particles in said bath to organic film-forming material in said bath is maintained above 3:1, (B) the concentration of organic film-forming material in said bath is maintained in the range of about 0.2 to about 7 weight percent based on the total weight of the bath, and (C) the total weight of non-volatile solids in said bath is maintained below about 35 weight percent of said bath, and (C) heating said substrate and resultant codeposition coating thereon in a heating zone in an ambient essentially inert to said metal particles and said coating to a decomposition temperature above the temperature required to decompose the organic film-forming material in said coating and below the diffusion temperature of said metal particles, maintaining said decomposition temperature until said organic film forming material is essentially decomposed and gaseous products thereof are formed in said heating zone, essentially evacuating said gaseous products from said heating zone, maintaining said substrate in said heating zone in an ambient essentially inert to the metal particles and raising the temperature of said heating zone to a diffusion temperature of at least 50° above melting point of aluminum and below about 2200° F., and maintaining said diffusion temperature and said ambient for a time in excess of about 1 hour.

Claim 31

A process for modifying the surface of a metal substrate of which the major component by weight is selected from cobalt, nickel and iron and constitutes at least 40 weight percent of said substrate, said process comprising (a) providing said substrate with a surface coating of a dry coagulating compound, (b) codepositing by coagulation on said metal substrate a coating of (I) metal particles having an average diameter in the range of 0.5 to 20 microns and selected from (A) aluminum comprising particles wherein the weight ratio of aluminum to other metal is in the range of 200:1 to 1:3 and which are selected from (1) aluminum alloy particles, (2) a mixture of aluminum particles and particles of at least one other metal, (3) a mixture of aluminum particles and particles of at least one metal oxide, and (4) a mixture of aluminum particles and particles of at least one alloy, or (B) aluminum particles; and (II) a heat fugitive organic film-forming material consisting essentially of at least 50 weight percent of a chemically ionizable, organic film-former having at least 12 carbon atoms per molecule and a remainder of organic film-former which is not chemically ionizable, in a metal particle to organic film-forming material weight ratio in excess of 3:1, from an aqueous dispersion forming a coating bath which, except for solvent, consists essentially of said metal particles and said organic film-forming material, said chemically ionizable organic film-former being at least partically ionized and adapted to coagulate and deposit in the presence of said coagulating compound, and wherein (A) the weight ratio of metal particles in said bath to organic film-forming material in said bath is maintained above 3:1, (B) the concentration of organic film-forming material in said bath is maintained in the range of about 0.2 to about 7 weight percent based on the total weight of the bath, and (C) the total weight of non-volatile solids in said bath is maintained below about 35 weight percent of said bath, and (C) heating said substrate and resultant codeposition coating thereon in a heating zone in an ambient essentially inert to said metal particles and said coating to a decomposition temperature above the temperature required to decompose the organic film-forming material in said coating and below the diffusion temperature of said metal particles, maintaining said decomposition temperature until said organic film forming material is essentially decomposed and gaseous products thereof are formed in said heating zone, essentially evacuating said gaseous products from said heating zone, maintaining said substrate in said heating zone in an ambient essentially inert to the metal particles and raising the temperature of said heating zone to a diffusion temperature of at least 50° above melting point of aluminum and below about 2200° F., and maintaining said diffusion temperature and said ambient for a time in excess of about 1 hour.

Claim 32

A process in accordance with claim 28, wherein said coagulating compound is a metal salt having a pH of less than 7.0 and said organic film-former is a synthetic polycarboxylic resin which is at least partially neutralized with a water soluble base.

Claim 33

A process in accordance with claim 29, wherein said metal salt is formed at least in part by treating said substrate with an acid.

Claim 34

A process in accordance with claim 29 wherein said polycarboxylic acid resin has (i) an electrical equivalent weight between about 1,000 and about 20,000, and (ii) an acid number between about 30 and about 300.

Claim 35

A process in accordance with claim 29 wherein said salt is selected from the group consisting of nickel chloride, cupric chloride, cobaltous chloride, cupric nitrate, nickel nitrate, cupric sulfate, zinc chloride and mixtures thereof.

Claim 36

A process in accordance with claim 28 wherein said coating has an average depth of about 3 and about 7 mils and said diffusion temperature is in the range of about 1300° F. to bout 2100° F.

Claim 37

A process in accordance with claim 28 wherein said weight ratio of metal particles in said bath to organic film-forming material in said bath is maintained in the range of 5:1 to 20:1.

Claim 38

A process in accordance with claim 28 wherein said concentration of organic film-forming material in said bath is maintained in the range of about 0.2 to about 2 weight percent.

Claim 39

A process in accordance with claim 28, wherein said coagulating compound is selected from the group consisting of (i) bases having a pH greater than 10.0, (ii) basic salts and (iii) mixtures thereof, and said organic film-former is selected from basic monomers and resins having one or more nitrogens in their molecular structure and is at least partially neutralized by a water soluble acid compound.