Classifications

• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
  • C09D163/00—Coating compositions based on epoxy resins; Coating compositions based on derivatives of epoxy resins
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
  • C09D5/00—Coating compositions, e.g. paints, varnishes or lacquers, characterised by their physical nature or the effects produced; Filling pastes
  • C09D5/44—Coating compositions, e.g. paints, varnishes or lacquers, characterised by their physical nature or the effects produced; Filling pastes for electrophoretic applications
  • C09D5/4488—Cathodic paints
  • C09D5/4492—Cathodic paints containing special additives, e.g. grinding agents
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G59/00—Polycondensates containing more than one epoxy group per molecule; Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups
  • C08G59/14—Polycondensates modified by chemical after-treatment
  • C08G59/1433—Polycondensates modified by chemical after-treatment with organic low-molecular-weight compounds
  • C08G59/1438—Polycondensates modified by chemical after-treatment with organic low-molecular-weight compounds containing oxygen
  • C08G59/1444—Monoalcohols
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G59/00—Polycondensates containing more than one epoxy group per molecule; Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups
  • C08G59/14—Polycondensates modified by chemical after-treatment
  • C08G59/1433—Polycondensates modified by chemical after-treatment with organic low-molecular-weight compounds
  • C08G59/1483—Polycondensates modified by chemical after-treatment with organic low-molecular-weight compounds containing sulfur
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L63/00—Compositions of epoxy resins; Compositions of derivatives of epoxy resins
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
  • C09D5/00—Coating compositions, e.g. paints, varnishes or lacquers, characterised by their physical nature or the effects produced; Filling pastes
  • C09D5/44—Coating compositions, e.g. paints, varnishes or lacquers, characterised by their physical nature or the effects produced; Filling pastes for electrophoretic applications
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
  • C09D5/00—Coating compositions, e.g. paints, varnishes or lacquers, characterised by their physical nature or the effects produced; Filling pastes
  • C09D5/44—Coating compositions, e.g. paints, varnishes or lacquers, characterised by their physical nature or the effects produced; Filling pastes for electrophoretic applications
  • C09D5/4419—Coating compositions, e.g. paints, varnishes or lacquers, characterised by their physical nature or the effects produced; Filling pastes for electrophoretic applications with polymers obtained otherwise than by polymerisation reactions only involving carbon-to-carbon unsaturated bonds
  • C09D5/443—Polyepoxides
  • C09D5/4457—Polyepoxides containing special additives, e.g. pigments, polymeric particles

Definitions

• the invention relates to a method for coating electrically conductive substrates, in which
• the substrate is immersed in an aqueous electrocoating bath which contains a cathodically depositable synthetic resin,
• the invention also relates to substrates coated by the process according to the invention and to the electrocoating baths used in the process according to the invention.
• cathodic electrodeposition coating is a coating method which is frequently used primarily for priming and is used in particular for priming automobile bodies. Methods of the type described above are e.g. B. disclosed in the following patent documents: DE-OS-35 18 732,
• the task on which the present invention is based consists in providing a new method according to the preamble of patent claim 1.
• the new method is intended in particular to overcome or reduce the problems of the prior art set out above.
• lacquer films can be obtained which, compared to the lacquer films of the prior art, have less and / or less pronounced surface defects and in overpainted lacquer layers - especially in overpainted lacquer layers that contain alkyd resins as binders - do not cause any damage due to impaired adhesion.
• US Pat. No. 3,975,250 discloses catalytic reactive plasticizers which can be used in electrocoating baths and which are prepared by reacting partially capped polyisocyanates with polyoxypropylene diamines.
• US Pat. No. 4,423,166 discloses an electrodeposition process according to the preamble of claim 1, which is characterized in that the electrodeposition bath contains an adduct of a polyoxyalkylene polyamine and a polyepoxide as an anti-cratering agent.
• the paint films obtained with the process disclosed in US Pat. No. 4,423,166 show a lower tendency to form surface defects, but cause damage in overpainted paint layers that can be attributed to adhesion problems. Such damage occurs in particular in overpainted paint layers, the alkyd resins included as a binder.
• Electrocoating baths for cathodic electrocoating are preferably produced by firstly preparing an aqueous dispersion which contains a cathodically depositable synthetic resin, optionally a crosslinking agent and other customary additives, such as e.g. Defoamers, etc. contains.
• a pigment paste is then incorporated into this aqueous dispersion.
• the pigment paste consists of a rubbing resin and pigments and / or fillers.
• the pigment paste can also contain other additives such as Contain plasticizers, wetting agents, antioxidants, etc.
• pigments or fillers which may be present in the pigment paste are: titanium dioxide, antimony oxide, zinc oxide, basic lead carbonate, basic lead sulfate, barium carbonate, porcelain, clay, Calcium carbonate, aluminum silicate, silicon dioxide, magnesium carbonate, magnesium silicate, cadmium yellow, cadmium red, carbon black, phthalocyanine blue, chrome yellow, toluidyl red and hydrated iron oxide.
• the pigment paste is added to the aqueous dispersion described above in such an amount that the finished electrocoating bath has the properties required for the deposition.
• the weight ratio between pigment or filler and the total amount of cathodically depositable synthetic resin contained in the electrocoating bath is 0.05 to 0.5.
• the electrocoating baths used in accordance with the invention can in principle contain all cathodically separable external or self-crosslinking synthetic resins which are suitable for the production of electrocoating baths.
• the electrocoating baths used according to the invention can also contain mixtures of different cathodically depositable synthetic resins.
• the electrocoating baths which contain cationic amine-modified epoxy resins as cathodically depositable synthetic resins are preferred. Both self- and externally cross-linking cationic amine-modified epoxy resins are known. External crosslinking are preferred cationic amine-modified epoxy resins used.
• Cationic reaction products are formed from cationic amine-modified epoxy resins
• Polyepoxides are understood to mean compounds which contain two or more epoxy groups in the molecule.
• Particularly preferred (A) components are compounds which can be prepared by reacting
• component (b) a compound which reacts monofunctionally to epoxy groups under the given reaction conditions and contains a phenol or thiol group or a mixture of such compounds, components (a) and (b) in a molar ratio of from 10: 1 to 1: 1, preferably 4 : 1 to 1.5: 1, are used and the reaction of component (a) with component (b) is carried out at 100 to 190 ° C., if appropriate in the presence of a catalyst (cf. DE-0S-35 18 770 ).
• compositions which can be prepared by a starter which reacts at 100 to 195 ° C., optionally in the presence of a catalyst, by a monofunctional reactant which either has an alcoholic OH group or a phenolic one
• Diepoxidtheticen optionally together with at least one monoepoxy compound, to an epoxy resin in which The epoxy compound and starter are incorporated in a molar ratio of greater than 2: 1 to 10: 1 (cf. DE-OS-35 18 732).
• Polyepoxides which can be used for the production of the particularly preferred (A) components and also themselves as (A) components are polyglycidyl ethers of polyphenols prepared from polyphenols and epihalohydrins.
• polyphenols e.g. bisphenol A and bisphenol F are very particularly preferably used.
• polyepoxides are polyglycidyl ethers of polyhydric alcohols, e.g. Ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,4-propylene glycol, 1,5-pentanediol, 1,2,6-hexanetriol, glycerin and bis- (4-hydroxycyclohexyl-) 2,2- propane.
• polyhydric alcohols e.g. Ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,4-propylene glycol, 1,5-pentanediol, 1,2,6-hexanetriol, glycerin and bis- (4-hydroxycyclohexyl-) 2,2- propane.
• Polyglycidyl esters of polycarboxylic acids e.g. Oxalic acid, succinic acid, glutaric acid, terephthalic acid, 2,6-naphthalenedicarboxylic acid, dimerized linoleic acid can be used.
• Oxalic acid e.g. Oxalic acid, succinic acid, glutaric acid, terephthalic acid, 2,6-naphthalenedicarboxylic acid, dimerized linoleic acid
• Typical examples are glycidyl adipate and glycidyl phthalate.
• Hydantoine epoxides epoxidized polybutadiene and polyepoxide compounds which are obtained by epoxidizing an olefinically unsaturated aliphatic compound are also suitable.
• Modified polyepoxides are understood to be polyepoxides in which some of the reactive groups have been reacted with a modifying compound.
• modifying compounds are: a) Compounds containing carboxyl groups, such as saturated or unsaturated monocarboxylic acids (eg benzoic acid, linseed oil fatty acid, 2-ethylhexanoic acid, versatic acid), aliphatic, cycloaliphatic and / or aromatic dicarboxylic acids of various chain lengths (eg adipic acid, sebacic acid, isophthalic acid or dimeric fatty acid carboxylic acids) eg lactic acid, dimethylolpropionic acid) and carboxyl-containing polyesters or
• saturated or unsaturated monocarboxylic acids eg benzoic acid, linseed oil fatty acid, 2-ethylhexanoic acid, versatic acid
• aliphatic, cycloaliphatic and / or aromatic dicarboxylic acids of various chain lengths eg adipic acid, sebacic acid, isophthalic acid or dimeric fatty acid carboxylic acids
• N, N'-dialkylalkylenediamines such as dimethylethylene diamine, N.N'-dialkyl polyoxyalkylene amines such as N, N'-dimethyl-polyoxypropylene diamine, cyanoalkylated alkylene diamines such as bis-N.N'-cyanoethyl ethylene diamine, cyanoalkylated polyoxyamine, alkylene amines such as Bis-N.N'-cyanoethylpropoxylenediamine, polyaminoamides such as Versamides, especially reaction products containing terminal amino groups from diamines (eg hexamethylenediamine), polycarboxylic acids, especially dimer fatty acids ⁇ and monocarboxylic acids, especially fatty acids, or the reaction product of one mole of diaminohexane with two mole of the reaction product of one mole of diaminohexane with two mole of the reaction product of one mole of diaminohexane
• hydroxyl groups such as neopentyl glycol, bis-ethoxylated neopentyl glycol, hydroxipivalic acid neopentyl glycol esters, dimethylhydantoin-N, N'-diethanol, 1,6-hexanediol, 2,5-hexanediol, 1,4-bis (hydroximethyl) cyclohexane, 1 , l-isopropylidene-bis- (p-phenoxy) -2-propanol, trimethylolpropane, pentaerythritol or amino alcohols such as triethanolamine, methyldiethanolamine or hydroxyl-containing alkylketimines such as aminomethylpropanediol-1,3-methyl-isobutylketimine or tris (hydroximethyl) aminomine -cyclohexanonketi in and also polyglycol ethers, polyester polyols, polyols, polyo
• component (B) Primary or secondary amines or their salts, salts of tertiary amines or mixtures of these compounds can be used as component (B).
• Water-soluble amines are preferably used as (B) components.
• amines which can be used are mono- and dialkylamines, such as methylamine, ethylamine, propylamine, butylamine, dimethylamine, diethylamine, dipropylamine, methylbutylamine, etc.
• Alkanolamines e.g. Methylethanola in and Diethanola in are used as (B) components.
• Ketimines of polyamines with primary and secondary amino groups can also be used as (B) components.
• Dialkylaminoalkylamines such as, for example, dimethylaminoethylamine, diethylaminopropylamine and dimethylainopropylamine, can also be used as (B) component.
• Secondary amines are preferably used as (B) components.
• component (B) In many cases, several different amines are used as component (B).
• the positive charges required for water dilutability and electrical separability can be introduced into the binder molecules by protonation with water-soluble acids (for example boric acid, formic acid, lactic acid, preferably acetic acid) and / or by using amine salts as (B) components .
• water-soluble acids for example boric acid, formic acid, lactic acid, preferably acetic acid
• amine salts as (B) components .
• the cationic amine-modified epoxy resins used according to the invention are essentially free of epoxy groups, ie their epoxy group content is so low that crosslinking reactions via epoxy groups cannot occur either before or after the coating film has been deposited.
• the cationic amine-modified epoxy resins used according to the invention preferably contain no free epoxy groups.
• the cationic amine-modified epoxy resins can be used both as externally crosslinking synthetic resins and as self-crosslinking synthetic resins.
• Self-crosslinking cationic amine-modified epoxy resins can be obtained, for example, by chemical modification of the cationic amine-modified epoxy resins.
• a self-crosslinking cationic amine-modified epoxy resin. can e.g. are obtained by reacting the cationic amine-modified epoxy resin with a partially blocked polyisocyanate, which has on average one free isocyanate group per molecule and whose blocked isocyanate groups are only unblocked at elevated temperatures.
• Preferred electrocoating baths are obtained if externally crosslinking cationic amine-modified epoxy resins are used as the cathodically depositable synthetic resins in combination with a suitable crosslinking agent.
• crosslinking agents examples include phenoplasts, polyfunctional Mannich bases, melamine resins, benzoguanamine resins, blocked polyisocyanates and compounds which contain at least two groups of the general formula R -0-C0-.
• R 1 R 0-C0-CH 2 -, R 3 -CH0H-CH 2 -, R 4 -CH0R 5 -CH0H-CH -
• R 2 alkyl
• R 3 H, alkyl, R 6 -0-CH or R 6 -C0-0-CH 2 -
• R 4 H or alkyl
• R 5 - H alkyl or aryl
• R alkyl, cycloalkyl or aryl
• Preferred electrocoating baths are obtained when • blocked polyisocyanates and / or compounds containing at least two groups of the general formula R -0-C0- are used as crosslinking agents.
• Any polyisocyanate in which the isocyanate groups have been reacted with a compound can be used as blocked polyisocyanates, so that the blocked polyisocyanate formed is resistant to hydroxyl and amino groups at room temperature, at elevated temperatures, generally in the range of about 90 ° C to about 300 C, but reacts.
• Any organic polyisocyanates suitable for crosslinking can be used in the preparation of the blocked polyisocyanates.
• the isocyanates which are approximately 3 to 36, in particular approximately, are preferred
• diisocyanates Contain 8 to about 15 carbon atoms.
• suitable diisocyanates are hexamethylene diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate and 1-isocyanatomethyl-5-isocyanato-1,3,3-trimethylcyclohexane.
• Polyisocyanates with higher isocyanate functionality can also be used. Examples of this are trimerized hexamethylene diisocyanate and trimerized isophorone diisocyanate. Mixtures of polyisocyanates can also be used.
• organic polyisocyanates which are suitable as crosslinking agents in the invention can also be prepolymers which are derived, for example, from a polyol including a polyether polyol or a polyester polyol. Any suitable aliphatic, cycloaliphatic or aromatic alkyl mono alcohols can be used to block the polyisocyanates.
• Examples include aliphatic alcohols such as methyl, ethyl, chloroethyl, propyl, butyl, amyl, hexyl, heptyl, octyl, nonyl, 3,3,5-trimethylhexyl, decyl and lauryl alcohol ; cycloaliphatic alcohols such as cyclopentanol and cyclohexanol; aromatic alkyl alcohols, such as phenylcarbinol and methylphenylcarbinol.
• blocking agents are hydroxylamines such as ethanolamine, oximes such as methyl ethyl ketone oxime, acetone. oxime and cyclohexanone oxime or amines such as dibutylamine and diisopropylamine.
• hydroxylamines such as ethanolamine
• oximes such as methyl ethyl ketone oxime, acetone.
• the polyisocyanates and blocking agents mentioned can also be used, in suitable proportions, for the preparation of the partially blocked polyisocyanates mentioned above.
• Examples of compounds which contain at least two groups of the general formula R -0-C0- are bis (carbalkoxymethyl) azelate, bis (carbalkoxymethyl) sebacate, bis (carbalkoxymethyl) adipate, bis (carbalkoxymethyl) decana, Bis (carbalkoxymethyl) terephthalate, bis (2-hydroxybutyl) acelate and bis (2-hydroxyethyl) terephthalate.
• the crosslinking agent is generally used in an amount of 5 to 60% by weight, preferably 20 to 40% by weight, based on the total amount of crosslinkable cathodically depositable synthetic resin contained in the electrodeposition paint.
• electrodeposition baths are used in the process according to the invention which contain at least 7.5% by weight of a polyoxyalkylene polyamine or a mixture of several polyoxyalkylene polyamines with different chemical structures, the weight 96 being based on those contained in the electrodeposition bath Total amount of binders relates.
• Polyoxyalkylene polyamines are understood to mean compounds which contain both oxyalkylene groups and at least two amino groups, preferably at least two primary amino groups.
• the polyoxyalkylene polyamines should have a number average molecular weight of about
• polyoxyalkylene polyamines should have an amine equivalent weight of about 69 to about 1800, preferably 200 to 1500, particularly preferably 400 to 1250.
• Polyoxyalkylene polyamines used with preference have a chemical structure according to the general formula (I)
• R H or alkyl radical with 1 to 6 carbon atoms, preferably
• ⁇ CH 3 n 5-60, preferably 20-40
• Polyoxyalkylene polyamines having a chemical structure according to general formula (I) are disclosed in U.S. Patent 3,236,895 at column 2, lines 40-72. Methods for making these polyoxyalkylene polyamines are disclosed in Patent Examples 4, 5, 6, and 8 to 12 found in columns 4 to 9 of U.S. Patent 3,236,895.
• polyoxyalkylene polyamines which contain different oxyalkylene groups
• polyoxyalkylene polyamines which have a chemical structure in accordance with the general formula (II):
• polyox alkylene polyamine derivatives which are obtainable by reacting the polyoxyalkylene polyamines described in US Pat. No. 3,236,895 in column 2, lines 40-72 with acrylonitrile and subsequent hydrogenation of the reaction product. These derivatives have a chemical structure of rak- '• general structural formula (III):
• the electrocoating baths used according to the invention can also contain a mixture of several polyoxyalkylene polyamines with different chemical structures.
• the polyoxyalkylene polyamines or polyoxyalkylene polyamine mixtures can be incorporated into the electrocoating baths at any time during production and also after the electrocoating baths have been completed.
• the Poly ⁇ oxyalkylenpolyamine or. Polyoxyalkylene polyamine mixtures are preferably used for the aqueous dispersion or for a precursor of the aqueous dispersion which contains a cathodically depositable synthetic resin, possibly a crosslinking agent and other usual additives such as defoamers etc. (see p. 4, lines 19ff.) Or for pigment paste or to a preliminary stage of pigment paste (see p.4, lines 26ff.) admitted.
• the polyoxyalkylene polyamine molecules are most likely protonated by the acid contained in the aqueous dispersion or pigment paste.
• the corresponding polyoxyalkylene polyamine or polyoxyalkylene polyamine mixture in protonated form to the aqueous dispersion in question or to a precursor of this dispersion or to the pigment paste or to a precursor of the pigment paste.
• the protonated polyoxyalkylene polyamine or polyoxyalkylene polyamine mixture can be obtained by simply adding a Bronsted acid to the corresponding polyoxyalkylene polyamine or polyoxyalkylene polyamine mixture.
• the total amount of Bronsted acid contained in the finished electrocoating bath is to be selected so that the pH of the electrocoating bath is between 4 and 8, preferably between. 5 and 7.5.
• the amount of polyoxyalkylene polyamine or polyoxyalkylene polyamine mixture contained in the electrocoating baths used in accordance with the invention is at least 7.5% by weight, the% by weight relating to the total amount of binders contained in the electrocoating bath .
• the electrocoating baths used according to the invention must contain at least 7.5 parts by weight of polyoxyalkylene polyamine or polyoxyalkylene polyamine mixture per 100 parts by weight of binder.
• the upper limit of the amount of polyoxyalkylene polyamine or polyoxyalkylene polyamine mixture contained in the electrocoating baths used according to the invention is determined by the plasticizing effect of the polyoxyalkylene-polyamine or polyoxyalkylene-polyamine mixture added is generally from 20 to 40% by weight, the percentage by weight relating to the total amount of binders contained in the electrocoating bath.
• the electrocoating baths used according to the invention preferably contain 8 to 18, particularly preferably 10 to 15, by weight of 96 polyoxyalkylene polyamine or polyoxyalkylene polyamine mixture, the percentages by weight being based on the total amount of binders contained in the electrocoating bath.
• the total amount of binders contained in the electrocoating bath is determined by the amount of cathodically depositable synthetic resin contained in the electrocoating bath. the amount of crosslinking agents that may be present in the electrocoating bath, the amount of rubbing resin contained in the electrocoating bath and the amount of resins that crosslink under the baking conditions may also be added.
• the solids content of the electrocoating baths used according to the invention is preferably 7 to 35 parts by weight, particularly preferably 12 to 25 parts by weight.
• the electrocoating bath is brought into contact with an electrically conductive anode and with the electrically conductive substrate connected as a cathode.
• electrical current passes between the anode and cathode, a firmly adhering lacquer film is deposited on the cathode.
• the temperature of the electrocoating bath should be between 15 to 35 ° C, preferably between 20 to 30 ° C.
• the voltage applied can fluctuate over a wide range and can be, for example, between two and a thousand volts. Typically, however, voltages between 50 and
• the current density is usually
• the coated object is rinsed off and is ready for baking.
• the deposited lacquer films are generally baked at temperatures of 130 to 200 ° C. for a period of 10 to 60 minutes, preferably at 150 to 180 ° C. for a period of 15 to 30 minutes.
• the method according to the invention can be used for coating any electrically conductive substrates, but in particular for coating metals such as steel, aluminum, copper and the like.
• aqueous dispersions which contain a cathodically separable synthetic resin and a crosslinking agent.
• the resin has a solids content of 70.2% and a base content of 0.97 milliequivalents / gram.
• the resulting aqueous dispersion is freed of low-boiling solvents in a Q vacuum distillation and then diluted to a solids content of 33% with deionized water.
• the rubbing resin is mixed intensively with 1162 parts of 3Q deionized water and 22 parts of glacial acetic acid. 880 parts of TiO 2 , 250 parts of an extender based on aluminum silicate, 53 parts of lead silicate and 10 parts of carbon black are then mixed. This mixture is ground in a grinding unit on a 35 Hegman fineness of less than 12 microns.
• 2200 parts by weight of the dispersions according to item 1.3 are mixed with 700 parts of the pigment paste according to item 2.2 and adjusted to a bath solids content of 20% by weight with deionized water.
• the coating films are deposited on phosphated sheet at 300 V for 2 min.
• the bath temperature is 27 ° C.
• the films are baked at 165 ° C for 20 minutes.
• Electrocoating bath 1 dispersion according to 1.3.1 with paste according to 2.2
• Polyoxypropylenediamine content (based on the total amount of binders): 11.9% by weight
• Electrocoating bath 2 dispersion according to item 1.3.2 with paste according to item 2.2 polyoxypropylenediamine content
• Electrocoating bath 3 dispersion according to item 1.3.3 with paste according to item 2.2
• Polyoxypropylenediamine content 0% by weight

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• Life Sciences & Earth Sciences (AREA)
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• Chemical Kinetics & Catalysis (AREA)
• Engineering & Computer Science (AREA)
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• Medicinal Chemistry (AREA)
• Polymers & Plastics (AREA)
• Molecular Biology (AREA)
• General Chemical & Material Sciences (AREA)
• Emergency Medicine (AREA)
• Paints Or Removers (AREA)
• Application Of Or Painting With Fluid Materials (AREA)
• Conductive Materials (AREA)
• Agricultural Chemicals And Associated Chemicals (AREA)

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• 1988
  • 1988-01-22 DE DE3801787A patent/DE3801787A1/de not_active Withdrawn
  • 1988-12-15 AU AU30529/89A patent/AU617152B2/en not_active Ceased
  • 1988-12-15 AT AT88120996T patent/ATE78284T1/de active
  • 1988-12-15 KR KR1019890701740A patent/KR930008750B1/ko not_active IP Right Cessation
  • 1988-12-15 JP JP1502059A patent/JPH083061B2/ja not_active Expired - Lifetime
  • 1988-12-15 EP EP89902202A patent/EP0386156A1/de active Pending
  • 1988-12-15 EP EP19880120996 patent/EP0324951B1/de not_active Expired - Lifetime
  • 1988-12-15 WO PCT/EP1988/001164 patent/WO1989006673A1/de not_active Application Discontinuation
  • 1988-12-15 DE DE8888120996T patent/DE3872867D1/de not_active Expired - Lifetime
  • 1988-12-15 AU AU30529/89A patent/AU3052989A/en active Granted
  • 1988-12-15 BR BR888807879A patent/BR8807879A/pt not_active IP Right Cessation
  • 1988-12-15 ES ES198888120996T patent/ES2034140T3/es not_active Expired - Lifetime
• 1989
  • 1989-01-12 ZA ZA89252A patent/ZA89252B/xx unknown
  • 1989-01-20 CA CA000588746A patent/CA1335395C/en not_active Expired - Fee Related
  • 1989-01-20 CN CN89100299A patent/CN1026009C/zh not_active Expired - Fee Related

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