WO1999012660A1 - Procede de formation de films de revetement multicouches - Google Patents

Procede de formation de films de revetement multicouches Download PDF

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Publication number
WO1999012660A1
WO1999012660A1 PCT/JP1998/004099 JP9804099W WO9912660A1 WO 1999012660 A1 WO1999012660 A1 WO 1999012660A1 JP 9804099 W JP9804099 W JP 9804099W WO 9912660 A1 WO9912660 A1 WO 9912660A1
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WIPO (PCT)
Prior art keywords
coating film
bismuth
coating
curing
compound
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PCT/JP1998/004099
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English (en)
Japanese (ja)
Inventor
Tetsuya Yokoyama
Akira Kasari
Takeshi Yawata
Tadayoshi Hiraki
Yasuhiro Tomisaki
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Kansai Paint Co., Ltd.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
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Application filed by Kansai Paint Co., Ltd. filed Critical Kansai Paint Co., Ltd.
Priority to CA002303027A priority Critical patent/CA2303027A1/fr
Priority to EP98941831A priority patent/EP1027938A4/fr
Publication of WO1999012660A1 publication Critical patent/WO1999012660A1/fr

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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05D—PROCESSES FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05D7/00—Processes, other than flocking, specially adapted for applying liquids or other fluent materials to particular surfaces or for applying particular liquids or other fluent materials
    • B05D7/50—Multilayers
    • B05D7/52—Two layers
    • B05D7/54—No clear coat specified
    • B05D7/542—No clear coat specified the two layers being cured or baked together

Definitions

  • the present invention is formed in a method of forming a multilayer coating film by coating a cationic electrodeposition coating material and an aqueous intermediate coating material with an “et-on-et” coating, and then heating and cross-linking and curing both coating films together. Finish appearance of multi-layer coatings (smoothness, gloss, etc.) ⁇ Improving the interlayer adhesion of both coatings.
  • this multi-layer coating film has insufficient finished appearance such as smoothness and luster, and it has been difficult to eliminate this defect even by applying a top coat.
  • An object of the present invention is to solve the above-mentioned problems in a multilayer coating film composed of a cationic electrodeposition coating film and an aqueous intermediate coating film, and to provide a method for forming a multilayer coating film having excellent finished appearance and interlayer adhesion.
  • the purpose of this study was to use a block polyisocyanate compound as a cross-linking agent for both cationic electrodeposition coatings and aqueous intermediate coatings, and to cross-link and cure electrodeposition coatings. It can be achieved by adjusting the reaction so that it starts earlier than the intermediate coating film. As a result, the finished appearance of the multilayer coating film (smoothness, gloss, etc.) Are found to be improved, and the present invention
  • the present invention relates to a method of applying a cationic electrodeposition coating composition (A) containing a block polyisocyanate compound as a cross-linking agent and curing the formed electrodeposition coating film without curing the electrodeposition coating film.
  • An aqueous intermediate coating (B) containing a polyisocyanate compound as a crosslinking agent is applied to form an intermediate coating, and then heated to cure both coatings together to form a multilayer coating.
  • a method for forming a multilayer coating film characterized in that the crosslinking and curing reaction of the electrodeposition coating film is adjusted to start earlier than the crosslinking and curing reaction of the intermediate coating film.
  • the measurement of the time of the initiation of crosslinking and curing of the coating film of the cationic electrodeposition coating material (A) and the aqueous intermediate coating material (B) is performed using a pendulum-type viscoelasticity measuring device (manufactured by Toyo Ball Douin, Leo Vibron DDV-OPA type) This is performed using In concrete terms, the weight 2 2 g, using a pendulum inertia Mome down bets 8 5 0 g ⁇ cm 2, thickness 3 0 / painted on the steel sheet so as to zm uncured film after curing The pendulum is placed on a plate and heated at a predetermined temperature (for example, 140 to 180 ° C) for crosslinking and curing the coating film while vibrating the pendulum, and the value of the logarithmic decay rate of the pendulum is applied.
  • a predetermined temperature for example, 140 to 180 ° C
  • crosslinking and curing start time The time required from the start of heating to the time of the start of crosslinking and curing is referred to as “curing start time”. The shorter the time, the faster the crosslinking and curing reaction starts.
  • the comparison of the timing of cross-linking curing of both coatings is based on the results measured at the same temperature.
  • the cationic electrodeposition paint (A) used in the method of the present invention contains a block poly isocyanate compound as a crosslinking agent, and preferably has a base resin (A-1) having a hydroxyl group and a cationic group. It is a cationic electrodeposition coating composition containing a block poly isocyanate compound (A-2).
  • the base resin (A-1) the hydroxyl group participates in a crosslinking reaction with the block polyisocynate compound, and the cationic group contributes to form a stable aqueous dispersion.
  • Examples of (A-1) include the following.
  • the base resin (A-1) is a cationizing agent for the epoxy group of the polyepoxide resin which is included in the above (i) and which is excellent in anticorrosion obtained by the reaction between the polyphenol compound and epichlorohydrin. Is a product obtained by reacting
  • the polyepoxide resin is a low molecular weight or high molecular weight compound having two or more epoxy groups in one molecule, and is at least 200, preferably 400 to 400, more preferably 800. Those having a number average molecular weight in the range of 2,000 to 2,000 are suitable.
  • a polyepoxide resin those known per se can be used, for example, a polyphenol compound which can be produced by reacting a polyphenol compound with epichlorohydrin in the presence of an alcohol. Of polyglycidyl ethers. Examples of the polyphenol compounds that can be used here include bis (4-hydroxyphenyl) 1-2,2-propane, 4,4'-dihydroxybenzobenzophenone, and bis (4-hydroxyphenyl).
  • those particularly suitable for producing the base resin (A-1) have a number average molecular weight of at least about 380, preferably about 800 to about 200, And a polyglycidyl ether of a polyphenol compound having an epoxy equivalent of 190 to 200, preferably 40 to 100. This includes those partially reacted with polyols, polyether polyols, polyester polyols, polyamide amines, polycarboxylic acids, polyisocyanate compounds, etc., as well as ⁇ -force products. Those obtained by graft polymerization of acrylonitrile and acrylic monomers may also be used.
  • the reaction product (i) between the polyepoxy resin and the cationizing agent can be obtained by reacting most or all of the epoxy groups of the polyepoxide resin with the cationizing agent.
  • an amine compound such as a primary amine, a secondary amine, a tertiary amine, or a polyamine can be used.
  • an amine compound such as a primary amine, a secondary amine, a tertiary amine, or a polyamine.
  • a cationic group-containing resin by introducing a cationic group such as a secondary amino group, a tertiary amino group, or a quaternary ammonium base into the polyepoxy resin. it can.
  • Examples of the primary amine compound include methylamine, ethylamine, n-propylamine, isopropylamine, monoethanolamine, n-propanolamine, and isopropanolamine.
  • Examples of the secondary amine compound include getylamine, diethanolamine, di-n-propanolamine, diisopropanolamine, N-methylethanolamine, N-ethylethanolamine, and the like.
  • Examples of the tertiary amine compound include triethylamine, triethanolamine, N, N-dimethylethanolamine, N-methylethanolamine, N, N-ethylethylamine, and N-ethylethylamine.
  • polyamines examples include ethylenediamine, diethylenetriamine, hydroxyxethylaminoethylamine, ethylaminoethylamine, methylaminopropylamine, and dimethylamine. Noethylamine, dimethylaminopropylamine, and the like.
  • a basic compound such as ammonia, hydroxyamine, hydrazine, hydroxyshetyl hydrazine, N-hydroxyshetyl imidazoline is used as a cationizing agent, which is used as an epoxy group of the polyepoxy resin.
  • the basic group formed by the reaction may be converted to a cationic group by protonation with an acid.
  • Preferred acids that can be used are water-soluble organic carboxylic acids such as formic acid, acetic acid, glycolic acid, and lactic acid.
  • hydroxyl group contained in these cationic group-containing resins include, for example, a reaction with alkanolamine as the above-mentioned cationizing agent, and ring opening of force prolactone which may be introduced into a polyepoxide resin.
  • primary hydroxyl groups introduced by reaction with alkanolamine are preferred because of their excellent cross-linking reactivity with block polyisocyanate compounds (cross-linking agents).
  • cross-linking agents block polyisocyanate compounds
  • the content of the hydroxyl group in the base resin (A-1) is 20 equivalents in terms of hydroxyl equivalent. 5,000, especially 60 to 3,000, more preferably 100 to 1,000 mg KOHZg, and particularly, the primary hydroxyl group equivalent is in the range of 200 to 1,000 mg KOH / g. Is preferred.
  • the content of the cationic group is preferably at least the minimum necessary for stably dispersing the base resin in water, and is generally 3 to 3 in terms of KOH (mgZg solid content) (amine value). It is preferably in the range of 200, especially 5 to 150, more particularly 10 to 80.
  • the base resin (A-1) does not contain free epoxy groups in principle.
  • the block polyisocyanate compound (A-2) used as a cross-linking agent in the cationic electrodeposition coating (A) is a compound in which substantially all of the isocyanate groups of the polyisocyanate compound are volatile active hydrogen compounds. (Blocking agent) reacts and blocks it and renders it inactive at room temperature. When heated to a predetermined temperature or higher, the blocking agent dissociates and the original isocyanate group is regenerated, and the base resin (A — Involves in crosslinking reaction with 1).
  • Polyisocyanate compounds are aliphatic, alicyclic, and aromatic compounds having two or more free isocyanate groups in one molecule, such as hexamethylene diisocyanate and trimethylene diisocyanate.
  • Aliphatic diisocyanates such as sodium, tetramethylene diisocyanate, dimer monoacid diisocyanate, and lysine diisocyanate; isophorone diisocyanate, methylene bis (cyclohexyl isocyanate), methylcyclohexyl Alicyclic diisocyanates such as sandiisocyanate, cyclohexanediisocyanate, and cyclopentanediisocyanate; xylylene diisocyanate, tridiethylene isocyanate, diphenyl methane diisocyanate Aromatic diisocyanates such as polyisocyanate, naphthalene diisocyanate, and toluidine diisocyanate
  • Examples of the blocking agent used for temporary blocking of the isocyanate group of the polyisocyanate compound include phenol, cresol, xylenol, p-ethylphenol, o-isopropylphenol, p-isopropylphenol — Tert —butylphenol, p-tert-octylpheno
  • p-Phenol, thymol, p-naphthol, p-ditropanol, p-phenol-based blocking agents such as chlorophenol; methanol, ethanol, propanol, butanol, amyl alcohol, ethylene glycol, ethylene glycol monomethyl ether , Ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, propylene glycol monomethyl ether, methyl sorb, butyl sorb, methyl carbitol, benzyl alcohol, phenyl sorb, furfuryla Alcohol-based blocking agents such as norecol, cyclohexanol, methyl glycolate, butyl glycolate, diacetone alcohol, methyl lactate, and ethyl lactate; Active methylene blocking agents such as tilacetone, dimethyl malonate, getyl malonate, and ethyl acetate; mercapt
  • Imid-based blocking agents diphenylamine, xylidine, dibutylamine, phenylnaphthylamine, aniline, carbazole and other amine-based blocking agents; imidazole, 2-ethylimidazole, etc.
  • Imidazole blocking agents urea blocking agents such as urea, thiourea and ethylene urea; carbamate blocking agents such as phenyl N-phenylcarbamate and 2-oxazolidone; ethyleneimine, propyleneimidone Blocking agents such as imamidoxoxime, formaldoxime, acetoaldoxime, acetoxime, methylethylketoxime, diacetyl monooxime, cyclohexanone oxime, etc .; sodium bisulfite, potassium bisulfite Sulfite block such as Agents: ⁇ -caprolactam, 5-valerolactam, abutyrolactam, ⁇ -prop. Lactam blocking agents such as piolactam;
  • the reaction between the polyisocyanate compound and the active hydrogen compound (blocking agent) for preparing the block polyisocyanate compound ( ⁇ -2) can be carried out by a method known per se, and the resulting block is obtained. It is desirable that the polyisocyanate compound does not substantially contain a free isocyanate group.
  • the mixing ratio of the base resin (A-1) and the block polysocyanate compound ( ⁇ -2) is not particularly limited, but is generally based on the total solid weight of both components.
  • the base resin ( ⁇ -1) is 40 to 90%, particularly 50 to 80%
  • the block polyisocyanate compound ( ⁇ -2) is 60 to 10%, particularly 50 to 20.0%. It is preferably within the range of 0%.
  • Cationic electrodeposition paint ( ⁇ ) is used to remove the cationic groups in the base resin ( ⁇ -1). It can be prepared by neutralizing with acidic compounds such as acetic acid, formic acid, lactic acid, and phosphoric acid, and dispersing and mixing in water together with the block polyisocynate compound.
  • the pH of the aqueous dispersion is 3 to 9, especially 5 to 5. It is preferably within the range of 7, and the resin solid content concentration is suitably within the range of 5 to 30% by weight.
  • the cationic electrodeposition paint (A) may include, if necessary, a hydroxide of a metal selected from aluminum, nickel, zinc, stotium, zirconium, molybdenum, tin, antimony, lanthanum, tungsten, etc.
  • a curing catalyst having an anti-oxidation property such as an oxide, an organic acid salt, or an inorganic acid salt; an extender pigment; a coloring pigment; an anti-pigment pigment;
  • tin octoate dibutyltin dilaurate, a manganese-containing compound, and a cobalt-containing compound are used.
  • a curing catalyst such as dibutyltin maleate, dibutyltin diacetate, dibutyltin dilaurethmercaptide-triethylenediamine, and dimethyltin dichloride can be blended.
  • the compounding amount is generally 0.1 to 10 parts by weight, particularly 0.5 to 2 parts by weight, per 100 parts by weight of the total of the base resin (A-1) and the block polyisocyanate compound (A-2).
  • a bismuth-containing compound (A-3) is further used as the cationic electrodeposition coating material (A), in addition to the aforementioned base resin (A-1) and block polyisocyanate compound (A-2). It is desirable to use the lead-free cationic electrodeposition paint contained. As a result, environmental health It is possible to form an electrodeposition coating film having excellent anti-corrosion properties and curability without using a lead compound which is a problem.
  • bismuth-containing compounds that can be added to the cationic electrodeposition coating (A) include bismuth oxides, hydroxides, salts with inorganic or organic acids, and include, for example, bismuth hydroxide, bismuth trioxide, and nitric acid.
  • Bismuth, bismuth benzoate, bismuth citrate, bismuth oxycarbonate, bismuth gaylate and the like are mentioned, and among them, bismuth hydroxide is preferred.
  • These bismuth-containing compounds are generally used in an amount of 0.1 to 10 parts by weight, especially 0.1 part by weight, per 100 parts by weight of the total of the base resin (A-1) and the block polyisocyanate compound (A-2). It can be blended in the range of 15 to 7.5 parts by weight, more particularly 0.2 to 5 parts by weight.
  • the bismuth-containing compound (A-3) a water-insoluble bismuth compound and a compound represented by the formula
  • R 1 represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms
  • R 2 represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms
  • n is 0 or 1
  • An aliphatic carboxylic acid-modified bismuth compound obtained by mixing and dispersing the aliphatic carboxylic acid shown in an aqueous medium in the presence of a dispersant, if necessary, disperses uniformly and stably in a water-insoluble form.
  • Bismuth aqueous dispersion paste can be used.
  • a water-dispersed paste containing a boronic acid-modified bismuth compound (hereinafter referred to as an aqueous dispersion paste of bismuth or simply a water-dispersed paste) is a method in which a water-insoluble bismuth compound and an aliphatic carboxylic acid represented by the above formula are dissolved in an aqueous medium. And by mixing and dispersing in the presence of a dispersant. At that time, the aliphatic carboxylic acid is used in such a ratio that the water-insoluble aliphatic carboxylic acid-modified bismuth compound is mainly produced.
  • the content of the water-soluble bismuth compound in the supernatant obtained by subjecting the aqueous dispersion of bismuth to centrifugal separation (at 1200 rpm for 30 minutes) is calculated as the weight of the metal bismuth,
  • the total amount of the water-insoluble bismuth compound used in the above is preferably about 40% or less, particularly about 30% or less, and more preferably about 20% or less.
  • Examples of the water-insoluble bismuth compound used in the preparation of such an aqueous dispersion paste of bismuth include, for example, bismuth oxide, bismuth hydroxide, basic bismuth carbonate, and the like having a solubility in water at 20 ° C of 0.0.
  • Bismuth compounds having a weight of 0.1 g or less are preferred, with bismuth oxide being particularly preferred.
  • the aliphatic carboxylic acid represented by the above formula is used for the purpose of converting the water-insoluble bismuth compound into a sufficiently uniform dispersion in an aqueous medium, and specifically, for example, Droxyacetic acid, lactic acid- Aliphatic hydroxycarboxylic acids such as hydroxypropionic acid; and aliphatic alkoxycarboxylic acids such as methoxyacetic acid, ethoxyacetic acid, and 3-methoxypropionic acid.
  • Droxyacetic acid lactic acid- Aliphatic hydroxycarboxylic acids such as hydroxypropionic acid
  • aliphatic alkoxycarboxylic acids such as methoxyacetic acid, ethoxyacetic acid, and 3-methoxypropionic acid.
  • lactic acid particularly L-lactic acid and methoxyacetic acid, are preferred. These can be used alone or in combination of two or more.
  • the aliphatic carboxylic acid may be used in combination with another organic acid, for example, acetic acid
  • the amount of the above-mentioned aliphatic cationic acid to be used is within a range in which the obtained aliphatic carboxylic acid-modified bismuth compound may be in a water-insoluble state, and varies depending on the kind of the aliphatic carboxylic acid used.
  • the molar ratio to the amount of bismuth in the water-insoluble bismuth compound is usually in the range of 0.5 to 1.7, preferably 0.75 to 1.3.
  • the molar ratio is based on the amount of bismuth in the water-insoluble bismuth compound.
  • the ratio can be generally in the range of 0.25 to 2.5, preferably 0.5 to 1.3.
  • a cationic dispersing resin or a surfactant known per se in the field of cationic electrodeposition coatings can be used without any limitation.
  • the cationic dispersing resin include those for electrodeposition coating described below.
  • the base resin can be appropriately selected and used from those listed.
  • resins such as tertiary amine type, quaternary ammonium salt type, and tertiary sulfonium salt type are exemplified.
  • the surfactant include nonionic surfactants such as acetylene glycol-based, polyethylene glycol-based, and polyhydric alcohol-based surfactants having an HLB in the range of 3 to 18, preferably 5 to 15. .
  • the amount of the dispersant used can vary depending on the type thereof, the amount of the water-insoluble bismuth compound used, and the like. It is preferably in the range of 1 to 150 parts by weight, particularly 10 to 100 parts by weight based on 0 parts by weight.
  • the production of the aqueous dispersion paste of bismuth using the water-insoluble bismuth compound, the aliphatic carboxylic acid and the dispersant described above can be performed in the same manner as the production of the pigment paste used in the cationic electrodeposition paint.
  • an aliphatic carboxylic acid and a water-insoluble bismuth compound are added to water containing a dispersant, and the mixture is dispersed in a dispersing mixer such as a ball mill or a sand mill. Can be manufactured.
  • the resulting water-dispersed pastes can generally have a solids concentration of 10 to 70% by weight, preferably 30 to 60% by weight.
  • the aqueous dispersion paste of bismuth may be prepared as a pigment paste by adding pigments used in ordinary cationic electrodeposition paints.
  • a pigment paste is prepared by blending a pigment dispersing resin, a neutralizing agent, and pigments, and performing a dispersion treatment in a dispersion mixer such as a ball mill or a sand mill, and then dispersing the bismuth in water. Paste can be added.
  • a neutralizing agent used for neutralizing the pigment dispersing resin for example, organic acids such as acetic acid, formic acid, and lactic acid can be used.
  • pigment-dispersing resin for example, a conventionally known pigment-dispersing resin can be used without any limitation.
  • a cation-type dispersing resin similar to that used for preparing the bismuth-dispersed paste can be used.
  • any pigment can be used without particular limitation as long as it is a pigment generally used in electrodeposition paints.
  • coloring pigments such as titanium oxide, carbon black, and red iron; , Talc, calcium carbonate, silica and other extenders; aluminum limolybdate, Waterproof pigments such as aluminum tripolyphosphate are mentioned.
  • an aqueous dispersion paste of bismuth or a pigment paste containing the aqueous dispersion paste can be blended with the binder-resin component of the cationic electrodeposition paint.
  • the bismuth dispersion base has a bismuth metal content of 0.1 per 100 parts by weight of the base resin (A-1) and the block polyisocyanate compound (A-2) in total. To 10 parts by weight, preferably 0.3 to 7 parts by weight, and more preferably 0.5 to 5 parts by weight.
  • the cross-linking and curing reaction of the cationic electrodeposition coating (A) coating film needs to start earlier than the cross-linking and curing reaction of the intermediate coating (B) coating film located in the upper layer.
  • the difference between the curing temperatures of the two coating films is preferably in the range of 5 to 20 ° C, particularly preferably in the range of 5 to 15 ° C.
  • the start time of the cross-linking curing reaction of the cationic electrodeposition coating (A) coating film can be easily controlled by, for example, appropriately selecting the type and the amount of the polyisocyanate compound, the blocking agent, the curing catalyst, and the like.
  • the “curing start time” from the start of heating to the start of cross-linking curing is suitably between 5 and 15 minutes in the coating process.
  • the object to be coated is a power source, carbon
  • the plate is preferably used as an anode, with a bath temperature of 20 to 35 ° C, a voltage of 100 to 400 V, a current density of 0.01 to 5 A, and an energization time of 1 to 10 minutes.
  • the coating film thickness can be about 10 to about a cured film.
  • the object to be coated include a substrate having a conductive metal surface, in particular, an automobile body, an electric product and the like.
  • the aqueous intermediate coating containing a block polyisocyanate compound as a cross-linking agent is applied to the coated surface without curing the coated film. Paint (B) is applied.
  • the aqueous intermediate coating composition (B) is an aqueous coating composition containing a block polyisocyanate compound as a crosslinking agent, and is preferably a base resin having a functional group capable of undergoing a crosslinking reaction with an isocyanate group such as a hydroxyl group.
  • This is a water-based paint containing (B-1) and a block polyisocyanate compound (B-2), which are mixed and dispersed in water.
  • Examples of the base resin (B-1) having a functional group capable of undergoing a crosslinking reaction with an isocyanate group such as a hydroxyl group in the aqueous intermediate coating material (B) include, for example, a polyester resin having two or more hydroxyl groups in one molecule. Acrylic resins are particularly preferred.
  • the hydroxyl group-containing polyester resin can be produced by subjecting a polybasic acid and a polyhydric alcohol to an esterification reaction by a method known per se, and has a number average molecular weight of 1,000 to 50,000, particularly 2,000 to 2,000, and a hydroxyl group.
  • the value is preferably from 20 to 200 mg KOHZg, especially from 50 to 150 mg K ⁇ H / g, and the acid value is preferably not more than 10 OmgKOHZg, especially from 10 to 70 mgK0HZg.
  • a polybasic acid is a compound having two or more carboxyl groups in one molecule.
  • phthalic acid isophthalic acid, terephthalic acid, succinic acid, adipic acid, azellanic acid, sebacic acid, tetrahydrophthalic acid, and hexakis
  • examples include phthalic acid, maleic acid, maleic acid, fumaric acid, itaconic acid, trimellitic acid, pyromellitic acid and anhydrides thereof.
  • Polyhydric alcohols are compounds having two or more hydroxyl groups in one molecule, such as ethylene glycol, propylene glycol, diethylene glycol, butylene glycol, hexanediol, diethylene glycol, dipropylene glycol, neopentyl glycol, Examples include hydrogenated bisphenol A, triethyleneglycol, glycerin, trimethylol-l-ethane, trimethyl-l-luppan, and pentaerythritol.
  • a hydroxyl group-containing acrylic resin can be produced by copolymerizing a hydroxyl group-containing polymerizable monomer and a polymerizable monomer component containing an acryl-based monomer under ordinary conditions.
  • the number average molecular weight is 1000 to 5000, especially 2000 to 20000, the hydroxyl value is 20 to 200 mg KOH / g, especially 50 to 150 mg KOH / g, and the acid value is 1 O Omg KOHZg or less, especially 20 to 7 Omg KOHZg. preferable.
  • the hydroxyl group-containing polymerizable monomer is a compound having at least one hydroxyl group and at least one polymerizable unsaturated bond in one molecule. Examples thereof include hydroxyxethyl (meta) acrylate, hydroxypropyl (meta). ) Monoesters of glycols having 2 to 20 carbon atoms and (meth) acrylic acid, such as acrylates and hydroxybutyl (meth) acrylates.
  • Examples of the acryl monomer include monoesters of (meth) acrylic acid and a monohydric alcohol having 1 to 22 carbon atoms, such as methyl acrylate and methyl acrylate.
  • hydroxyl-containing acrylic resin In the production of the hydroxyl-containing acrylic resin, other polymerizable monomers other than these hydroxyl-containing polymerizable monomers and acryl-based monomers can be used in combination.
  • polymerizable monomers include, for example, C 2 of (meta) allylic acid such as methoxybutyl acrylate, methoxybutyl methacrylate, methoxethyl acrylate, methoxyl ethyl methacrylate, and the like.
  • N-Jimechirua Mi Noechiruaku Li rate N, N-Jimechirua Mi Noechirume Tak Li rate
  • N, N-Jechiru A Mi Noechiruaku Li rate N, N-Jechirua Minoethyl methyl acrylate, N-t—Butylaminoethyl acrylate, N—t—Butylaminoethyl methacrylate, N, N-Dimethylaminopropyl acrylate, N, N-Dimethylaminopropyl methacrylate
  • Amino (meta) acrylic monomers such as acrylates
  • acrylamide, methacrylic N-methylacrylamide, N-methylacrylamide, N-ethylacrylamide, N-ethylacrylamide, N-butylacrylamide, N-butylacrylamide, N-butylacrylamide, N-butylmethacrylamide (Meth) acrylamide monomers such as N, N-d
  • the block polyisocyanate compound ( ⁇ -2) is a cross-linking agent for the base resin ( ⁇ -1), and has been specifically described as a cross-linking agent in the cationic electrodeposition paint ( ⁇ ).
  • One or more compounds selected from those exemplified as the block polyisocyanate compound (II-2) can be used.
  • the mixing ratio of the base resin ( ⁇ -1) and the block poly isocyanate compound ( ⁇ -2) is not particularly limited, but based on the total solid weight of both components.
  • the base resin ( ⁇ -1) may be in the range of 40 to 90%, especially 50 to 80%, and the block polyisocyanate compound ( ⁇ -2) may be in the range of 60 to 10%, especially 50 to 20%. preferable.
  • the aqueous intermediate coating ( ⁇ ) is composed of a base resin ( ⁇ -1) and a block polyisocyanate compound ( ⁇ -2), and a curing catalyst, extender, It may contain a coloring pigment, a surface conditioner and the like.
  • a curing catalyst one or more selected from those exemplified for the cationic electrodeposition coating ( ⁇ ) can be used.
  • the compounding amounts thereof are based on the base resin ( ⁇ -1) and the block polyisocynate. It is generally suitable that the amount is in the range of 0.1 to 10 parts by weight, especially 0.5 to 2 parts by weight, per 100 parts by weight of the compound ( ⁇ -2).
  • the timing of the start of crosslinking and curing of the coating of the aqueous intermediate coating ( ⁇ ) is determined based on the timing of starting the crosslinking of the coating of the cationic electrodeposition coating ( ⁇ ) located thereunder. More specifically, the cross-linking and curing reaction of the cationic electrodeposition paint (A) is started 0.5 to 10 minutes, especially 5 to 10 minutes later than the start of the cross-linking and curing reaction. Is preferred.
  • the “curing start time” required from the start of heating of the coating film of the aqueous intermediate coating material (B) to the start of cross-linking curing is the “curing start time” of the coating film of the cationic electrodeposition paint (A).
  • the difference is between 0.5 and 10 minutes, especially between 5 and 10 minutes.
  • the timing of the start of crosslinking and curing of the coating film of the aqueous intermediate coating composition (B) can be easily controlled by, for example, appropriately selecting the type and the amount of the polyisocyanate compound, the blocking agent, the curing catalyst, and the like.
  • the onset of the cross-linking and curing reaction of the coating of the aqueous intermediate coating (B) is later than the onset of the cross-linking and curing of the coating of the cationic electrodeposition coating (A). In 5.5 to 20 minutes, especially between 10 and 15 minutes is suitable.
  • the aqueous intermediate coating (B) is obtained by uniformly mixing and dispersing the base resin (B-1) and the block polyisocyanate compound (B-2) and optionally other additives in water. It is preferable that the solid content concentration is adjusted in the range of 20 to 70% by weight.
  • the cationic electrodeposition coating (A) is applied and, if necessary, dried at a temperature of 120 ° C. or less without curing, and then the aqueous intermediate coating (B) is coated on the electrodeposition coating. After coating, both films are heated and crosslinked and cured together.
  • the aqueous intermediate coating (B) is applied by electrostatic coating, airless spraying, air spraying, etc., and its film thickness is about 5 to about 80 m, especially about 15 to about 35 m, based on the cured coating. A range of ⁇ m is suitable.
  • both cation electrodeposition coating (A) coating and waterborne intermediate coating (B) coating were applied.
  • the heating temperature for curing the bridge is equal to or higher than the dissociation temperature of the block polyisocyanate compound contained in the coating film, but is usually about 130 to about 180 ° C.
  • the coating film can be hardened by baking for a minute.
  • a top coat such as a solid paint, a metallic paint, and a clear paint is coated on the multilayer coating film formed by the method of the present invention by a known method, for example, 1 coat 1 coat. Painted by wake-up method (1C1B), 2-coat 1-bake method (2C1B), 2-coat 2-bake method (2C2B), 3-coat 1-bake method (3C1B) can do.
  • the measurement of the cross-linking start time of the electrodeposited coating film and the aqueous intermediate coating film was performed using a pendulum type viscoelasticity meter (Toyo Baldwin, Leo Vibron DDV-OPA type).
  • Polyester resin (1) 1) Polyester resin (1):
  • Acrylic resin (1) 210 parts of styrene, 294 parts of n-butyl methacrylate, 253 parts of hydroxybutyl acrylate, 200 parts of 2-ethylhexyl methacrylate, and 30 parts of acrylic acid are placed in a reaction vessel and placed at 5 ° C at 120 ° C. After reacting for an hour, an acryl resin having a number average molecular weight of about 20,000, an acid value of 25 mg KOHZg, and a hydroxyl value of 95 mg KOHZg was obtained.
  • Bisphenol A type epoxy resin with epoxy equivalent of 630 (Epico 1002 (trade name, manufactured by Shell Chemical Co., Ltd.)) 1,260 parts are dissolved in 450 parts of butyl ether solvent, 132 parts of ⁇ -nonylphenol and 105 parts of N-methylethanolamine Then, the mixture was heated to 140 ° C. and reacted at the same temperature to obtain an additional epoxy resin having a solid content of 77% and an amine value of 52.
  • To 130 parts of this resin were added 30 parts of block polyisocyanate compound (curing agent) and 1.3 parts of polypropylene glycol (number average molecular weight 4000), and then 2.1 parts of acetic acid was added to make it water-soluble. 20% aqueous lead acetate solution 6.5 parts are added, then deionized water is gradually added and dispersed to obtain an emulsion having a solid content of 30%.
  • the above block polyisocyanate compound is obtained by reacting 174 parts of 2,6-tolylene diisocyanate with 85 parts of polycaprolactone diol having a hydroxyl equivalent of 425 to 2-ethylhexyl alcohol monoether of ethylene glycol. (Blocking agent).
  • the “dispersion paste of bismuth” was prepared as follows.
  • Aliphatic hexafunctional block polyisocyanate compound A hexameric methylene diisocyanate trimer is blocked with methylethylketoxime.
  • Titanium white pigment "Tika J R 806J (manufactured by Tika, trade name)” (Note 4) Riki Bon Black: “Mitsubishi Riki Bon Black M-100"
  • Polyester resin 1000 parts, Dimethylaminoethanol (Note 1) 40 parts, Aliphatic trifunctional block polyisocyanate compound (Note 5) 410 parts, Titanium white pigment (Note 3) 1400 parts And 20 parts of carbon black (Note 4) were mixed and dispersed in 1800 parts of deionized water to obtain an aqueous intermediate coating (2).
  • Acrylic resin 1000 parts, dimethylaminoethanol (Note 1) Mix 40 parts, aliphatic trifunctional block polyisocyanate compound (Note 5) 410 parts, titanium white pigment (Note 3) 1400 parts and carbon black (Note 4) 20 parts with 1800 parts of deionized water It was dispersed to obtain an aqueous intermediate coating (3).
  • Polyester resin (2) 1 00 parts, dimethylaminoethanol (Note 1) 40 parts, aliphatic trifunctional block polyisocyanate compound (Note 6) 410 parts, Titanium white pigment (Note 3) 1400 parts 20 parts were mixed and dispersed in 1800 parts of deionized water to obtain an aqueous intermediate coating (2).
  • Aliphatic trifunctional block polyisocyanate compound A hexamethylene diisocyanate trimer was blocked with ethyl malonate.
  • Polyester resin 1000 parts, Dimethylaminoethanol (Note 1) 40 parts, Melamine resin (Note 7) 300 parts, Titanium white pigment (Note 3) 1 400 parts and Rikibon black (Note 4) 20 parts was mixed and dispersed in 1800 parts of deionized water to obtain an aqueous intermediate coating composition (5).
  • Cathode dipped steel sheet treated with zinc phosphate is immersed in a cathodic electrodeposition paint (1) to (3) as a cathode, and electrodeposited at 30 ° C and 200 V for 3 minutes. 25 / m), dried at 100 ° C for 10 minutes, and then Each of the paints (1) to (5) was applied by air spray (thickness of the cured film is 30 to 35 ⁇ m), and then heated at 170 ° C for 30 minutes to crosslink and cure both films.
  • the test method is as follows.
  • Gloss 60 degree specular reflectance.
  • Sharpness The result of measurement with an image clarity measuring device (IMAGE CLARITY METER, manufactured by Suga Test Instruments Co., Ltd.).
  • the numbers in the table are ICM values, and take values in the range of 0 to 100. The larger the value, the better the sharpness (image clarity). If the ICM value is 80 or more, the sharpness is extremely good.
  • Impact resistance Using a Dupont-type impact tester, drop a weight of 500 g with a striker core of 1 inch and 2 inches with the coating surface facing upward. No drop occurs on the coating film. Cm).
  • Moisture resistance The test plate was allowed to stand for 72 hours under the conditions of 50 ° C and a humidity of 95%, and the appearance and adhesion of the coating film were examined. Appearance evaluation: ⁇ indicates no abnormality, ⁇ indicates slight blistering, and X indicates slight blistering. Adhesion is performed using a taper test (a 1m x 1mm gobber, 100 pieces) tape peeling test.

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  • Life Sciences & Earth Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Wood Science & Technology (AREA)
  • Application Of Or Painting With Fluid Materials (AREA)
  • Paints Or Removers (AREA)

Abstract

Cette invention concerne un procédé de formation d'un film de revêtement multicouches, lequel procédé comprend les étapes suivantes: appliquer une matière de revêtement par électrodéposition cationique qui contient un composé de polyisocyanate bloqué en qualité d'agent de réticulation; appliquer sur le film de revêtement obtenu par électrodéposition une matière de revêtement intermédiaire à base d'eau qui contient un composé de polyisocyanate bloqué en qualité d'agent de réticulation, ceci de manière à former un film de revêtement intermédiaire sans solidification du film de revêtement obtenu par électrodéposition; et enfin, chauffer les deux films de revêtement de manière à les solidifier simultanément. Ce procédé se caractérise en ce que les matières de revêtement sont contrôlées de manière à ce que la réaction de solidification et de réticulation du film de revêtement appliqué par électrodéposition commence avant celle du film de revêtement intermédiaire. Ce procédé permet d'obtenir un film de revêtement multicouches qui possède un meilleur aspect de finition (lissé, brillant, etc.), une bonne adhérence inter-laminaire entre les films de revêtement, etc.
PCT/JP1998/004099 1997-09-11 1998-09-11 Procede de formation de films de revetement multicouches WO1999012660A1 (fr)

Priority Applications (2)

Application Number Priority Date Filing Date Title
CA002303027A CA2303027A1 (fr) 1997-09-11 1998-09-11 Procede de formation de films de revetement multicouches
EP98941831A EP1027938A4 (fr) 1997-09-11 1998-09-11 Procede de formation de films de revetement multicouches

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP24658197 1997-09-11
JP9/246581 1997-09-11

Publications (1)

Publication Number Publication Date
WO1999012660A1 true WO1999012660A1 (fr) 1999-03-18

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EP (1) EP1027938A4 (fr)
CA (1) CA2303027A1 (fr)
WO (1) WO1999012660A1 (fr)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1046431A2 (fr) * 1999-04-19 2000-10-25 Kansai Paint Co., Ltd. Procédé pour l'élaboration de peintures multicouches
JP2001152088A (ja) * 1999-11-24 2001-06-05 Kansai Paint Co Ltd カチオン電着塗料組成物
JP2003525321A (ja) * 2000-03-01 2003-08-26 ビーエーエスエフ コーティングス アクチェンゲゼルシャフト 導電性支持体上に多層コーティングを製造する方法

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2017082076A (ja) * 2015-10-27 2017-05-18 旭化成株式会社 ポリイソシアネート組成物、塗料組成物及び塗装方法
CN113278130B (zh) * 2021-05-19 2022-08-05 万华化学集团股份有限公司 一种改性hdi三聚体、单组份聚氨酯胶及其制备方法、路面铺装材料

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS60251973A (ja) * 1984-05-25 1985-12-12 Nippon Paint Co Ltd 複層塗膜形成方法
JPS6473099A (en) * 1987-09-14 1989-03-17 Nissan Motor Electrodeposition coating method
JPH06228796A (ja) * 1992-10-23 1994-08-16 Herberts Gmbh 多層コーティングの製法
JPH07163936A (ja) * 1993-09-17 1995-06-27 Herberts Gmbh 多層ラッカーコーティングの製造方法

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS60251973A (ja) * 1984-05-25 1985-12-12 Nippon Paint Co Ltd 複層塗膜形成方法
JPS6473099A (en) * 1987-09-14 1989-03-17 Nissan Motor Electrodeposition coating method
JPH06228796A (ja) * 1992-10-23 1994-08-16 Herberts Gmbh 多層コーティングの製法
JPH07163936A (ja) * 1993-09-17 1995-06-27 Herberts Gmbh 多層ラッカーコーティングの製造方法

Non-Patent Citations (1)

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Title
See also references of EP1027938A4 *

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1046431A2 (fr) * 1999-04-19 2000-10-25 Kansai Paint Co., Ltd. Procédé pour l'élaboration de peintures multicouches
EP1046431A3 (fr) * 1999-04-19 2003-05-07 Kansai Paint Co., Ltd. Procédé pour l'élaboration de peintures multicouches
JP2001152088A (ja) * 1999-11-24 2001-06-05 Kansai Paint Co Ltd カチオン電着塗料組成物
JP2003525321A (ja) * 2000-03-01 2003-08-26 ビーエーエスエフ コーティングス アクチェンゲゼルシャフト 導電性支持体上に多層コーティングを製造する方法

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CA2303027A1 (fr) 1999-03-18
EP1027938A1 (fr) 2000-08-16

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