JP4959114B2 - Electrodeposition coating composition, electrodeposition bath management method and electrodeposition coating system - Google Patents

Description

  The present invention relates to an electrodeposition coating composition containing a pigment having excellent sedimentation stability, an electrodeposition bath management method and an electrodeposition coating system using the same.

  Electrodeposition coating is a coating method performed by immersing a coating object as an electrode in an electrodeposition coating composition and applying a voltage. This method can be applied even to a coating object having a complicated shape. Since it can be applied to the details and can be applied automatically and continuously, it is widely put into practical use as an undercoating method for an object having a large and complicated shape such as an automobile body.

  In general, a large amount of anti-rust pigments and extender pigments are added to electrodeposition paint compositions for the purpose of improving the anti-rust effect and physical properties of the coating film. Color pigments such as titanium white (titanium oxide), and hiding power High carbon black etc. are added as needed. These pigments are in a state of being dispersed in a solvent in the coating composition. Many of these pigments generally have a high specific gravity, so that precipitation tends to occur in the electrodeposition coating composition. For example, in a conventional electrodeposition coating composition containing an inorganic pigment, the inorganic pigment settles upon standing for only a few hours. And since the settled pigment aggregates strongly, it is very difficult to return to the original dispersed state even if stirring is performed again. In order to prevent such agglomeration, the electrodeposition tank and replenishment tank containing the electrodeposition coating composition need to be constantly stirred, which is a burden on the equipment and energy costs of the painter.

  As a method for preventing precipitation of pigments and the like, it can be considered to omit components such as pigments. However, by omitting components such as pigments, there is a concern that the physical properties of the coating film may be lowered, such as the corrosion resistance. JP-A-9-328641 (Patent Document 1) discloses a cationic electrodeposition coating composition having a sedimentation amount of 5.0 mg / hour or less. This cationic electrodeposition coating composition is achieved by omitting the sedimenting component as described above.

  On the other hand, as another method for improving the sedimentation stability of the electrodeposition coating composition, for example, a method using a specific pigment can be mentioned. For example, JP-A-6-340832 (Patent Document 2) contains 0.1 to 40 parts by weight of spherical high-purity amorphous silica powder with respect to 100 parts by weight of resin solid content of an electrodeposition paint. A characteristic electrodeposition coating composition is described. It is described that by using this spherical high-purity amorphous silica powder, sedimentation of titanium white, rust preventive pigment, etc. in the electrodeposition paint bath can be prevented. However, in this method, the sedimentation degree after standing for 5 hours is used as a sedimentation evaluation method, and it cannot be said that the sedimentation prevention effect is sufficient.

  International Publication No. 00/44840 pamphlet (Patent Document 3) includes an electrodeposition coating comprising a coating resin, a pigment, and water modified with a fatty acid obtained by enzymatic decomposition of vegetable oils and fats. A composition is described. Here, the fatty acid is used for modifying the resin for coating, and is different from the present invention in which the dispersion of the pigment is stabilized.

Japanese Patent Laid-Open No. 9-328641 JP-A-6-340832 International Publication No. 00/44840 Pamphlet

  It is an object of the present invention to solve the problems of the prior art. More specifically, an object of the present invention is to provide an electrodeposition coating composition having excellent sedimentation stability, including a pigment, particularly an inorganic pigment.

  The present invention relates to (a) a fatty acid, a derivative of fatty acid, an amine compound and a pigment settling inhibitor selected from the group consisting of one or a mixture of two or more thereof, and (b) an electrodeposition coating composition containing a pigment. The object is achieved by this.

  In the above electrodeposition coating composition, (a) a pigment settling inhibitor selected from the group consisting of fatty acids, fatty acid derivatives, amine compounds and mixtures of one or more of them, and (b) pigments are pigments It is preferably contained in the paste.

  The electrodeposition coating composition may be either cationic or anionic, and in the case of cationic, in addition to the components (a) and (b), a cationic resin, a block polyisocyanate curing agent, and Contains a curing catalyst. In the case of anionic, in addition to the components (a) and (b), an anionic resin, a curing agent and a curing catalyst are included.

  The fatty acid derivative may be a fatty acid ester, a fatty acid amide compound, or an ethylene oxide ring-opening adduct of a fatty acid ester or a fatty acid amide compound.

  The fatty acid preferably has 4 to 22 carbon atoms.

  In the amine compound, an alkyl group having 4 to 22 carbon atoms is preferably bonded to a nitrogen atom.

  The pigment settling inhibitor (a) is preferably contained in an amount of 0.1 to 20 parts by weight with respect to 100 parts by weight of the pigment.

The present invention also provides (a) a pigment dispersion preventing paste selected from the group consisting of fatty acids, fatty acid derivatives, amine compounds and mixtures of one or more of them, and (b) a pigment dispersion paste containing a pigment. A preparation step to prepare, and a dispersion step of dispersing the cationic resin, the blocked polyisocyanate curing agent, and the pigment dispersion paste in an aqueous medium,
A method for producing a cationic electrodeposition coating composition is provided.

Furthermore, the present invention provides (a) a pigment dispersion preventing paste selected from the group consisting of fatty acids, fatty acid derivatives, amine compounds and mixtures of one or more of them, and (b) a pigment dispersion paste containing a pigment. A preparation step to prepare, and a dispersion step of dispersing the anionic resin, the curing agent, and the pigment dispersion paste in an aqueous medium,
A method for producing an anionic electrodeposition coating composition is also provided.

  In the present invention, at the time of electrodeposition coating, a part of the electrodeposition bath is taken out and returned to the electrodeposition bath by a pump to circulate and stir the electrodeposition bath. When electrodeposition coating is not performed, the circulation pump is turned on. There is also provided an electrodeposition bath management method that stops, wherein the electrodeposition coating composition in the electrodeposition bath is as described above.

  The present invention further provides an electrodeposition bath containing the above-mentioned electrodeposition coating composition for electrodeposition-coating an object to be coated, a first water-washing bath for rinsing the electrodeposition-coated object, and the object to be coated A second water-washing bath for further washing with water, wherein a part of the electrodeposition bath in the electrodeposition bath is taken out and returned to the original bath by a pump, and the circulation stirring is performed by a stirring blade. An electrodeposition coating system is also provided in which energy is saved by switching to agitation using.

  The present invention also provides an electrodeposition bath containing the above-mentioned electrodeposition coating composition for electrodeposition-coating an object to be coated, a first water-washing bath for rinsing the electrodeposition-coated object, and the object to be coated An electrodeposition coating system having a second water-washing bath for washing with water, wherein the liquid in the first water-washing bath is stirred by a stirring blade.

  In the present invention, an electrodeposition bath containing the above-mentioned electrodeposition coating composition for electrodeposition-coating an article to be coated, a first water-washing bath for washing the electrodeposition-coated article with water, and further washing the article with water It is also possible to provide an electrodeposition coating system having a second water-washing bath, in which the liquid in the second water-washing bath is stirred by stirring blades.

  The electrodeposition coating composition of the present invention has few precipitates even when left standing for a long time. Therefore, constant stirring in storage of the electrodeposition coating composition and constant stirring of the electrodeposition tank in electrodeposition coating are not required, and stirring can be omitted or intermittently stirred. Thereby, the coating cost in electrodeposition coating can be reduced. In addition, according to the present invention, it is also possible to provide a paint containing an inorganic pigment and having little pigment sediment. When a pigment having a high refractive index and a high hiding power, such as titanium white, is included as the inorganic pigment, an electrodeposition coating composition capable of obtaining an electrodeposition coating film having high whiteness and high hiding power can be provided.

  The electrodeposition paint composition of the present invention can be classified into two types: a cationic electrodeposition paint using a cationic resin as a main resin, and an anion electrodeposition paint using an anion resin as a main resin. The electrodeposition coating composition of the present invention is used in a concept including all. First, the cationic electrodeposition coating composition will be described. The anion electrodeposition coating composition will be described later.

Cationic electrodeposition coating composition The cationic electrodeposition coating composition of the present invention contains a binder resin containing a cationic resin and a block polyisocyanate curing agent, a catalyst, and (a) a fatty acid, a fatty acid derivative, an amine compound, and It includes a pigment anti-settling agent selected from the group consisting of one or a mixture of two or more thereof, and (b) a pigment. In the present specification, “fatty acid” and “derivative of fatty acid” are sometimes collectively referred to as “fatty acids”.

Cationic Resin The cationic resin used in the present invention includes an epoxy resin modified with an amine. The cationic resin may be a known resin described in JP-A Nos. 54-4978 and 56-34186.

  Cationic resins typically open all of the epoxy rings of bisphenol-type epoxy resins with active hydrogen compounds that can introduce cationic groups, or some epoxy rings with other active hydrogen compounds. And the remaining epoxy ring is opened with an active hydrogen compound capable of introducing a cationic group.

  A typical example of the bisphenol type epoxy resin is a bisphenol A type or bisphenol F type epoxy resin. As the former commercial product, there are Epicoat 828 (manufactured by Yuka Shell Epoxy Co., Epoxy Equivalent 180-190), Epicoat 1001 (Same, Epoxy Equivalent 450-500), Epicoat 1010 (Same, Epoxy Equivalent 3000-4000) Examples of the latter commercially available product include Epicoat 807 (same as above, epoxy equivalent 170).

  Active hydrogen compounds that can introduce a cationic group include primary amines, secondary amines, tertiary amine acid salts, sulfides and acid mixtures. In order to prepare the primary, secondary or / and tertiary amino group-containing epoxy resin of the present invention, an acid salt of a primary amine, secondary amine, or tertiary amine is used as an active hydrogen compound capable of introducing a cationic group. Use.

  Specific examples include butylamine, octylamine, diethylamine, dibutylamine, methylbutylamine, monoethanolamine, diethanolamine, N-methylethanolamine, triethylamine hydrochloride, N, N-dimethylethanolamine acetate, diethyl disulfide / acetic acid mixture, etc. In addition, there are secondary amines in which primary amines such as aminoethylethanolamine ketimine and diethylenetriamine diketimine are blocked. A plurality of amines may be used in combination.

The blocked polyisocyanate curing agent cationic electrodeposition coating composition contains a blocked polyisocyanate curing agent obtained by blocking polyisocyanate with a blocking agent. Here, the polyisocyanate means a compound having two or more isocyanate groups in one molecule. The polyisocyanate may be, for example, any of aliphatic, alicyclic, aromatic and aromatic-aliphatic.

  Specific examples of polyisocyanates include aromatic diisocyanates such as tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), p-phenylene diisocyanate, and naphthalene diisocyanate; hexamethylene diisocyanate (HDI), 2,2,4- C3-C12 aliphatic diisocyanates such as trimethylhexane diisocyanate and lysine diisocyanate; 1,4-cyclohexane diisocyanate (CDI), isophorone diisocyanate (IPDI), 4,4'-dicyclohexylmethane diisocyanate (hydrogenated MDI) Methylcyclohexane diisocyanate, isopropylidene dicyclohexyl-4,4'-diisocyanate, and 1,3-diisocyanatomethyl cyclohexyl Carbon such as xane (hydrogenated XDI), hydrogenated TDI, 2,5- or 2,6-bis (isocyanatomethyl) -bicyclo [2.2.1] heptane (also referred to as norbornane diisocyanate). Aliphatic diisocyanates having a number of 5 to 18; aliphatic diisocyanates having aromatic rings such as xylylene diisocyanate (XDI) and tetramethylxylylene diisocyanate (TMXDI); modified products of these diisocyanates (urethanes, carbodiimides, Uretdione, uretoimine, burette and / or isocyanurate modified product); and the like. These may be used alone or in combination of two or more.

  Adducts or prepolymers obtained by reacting polyisocyanates with polyhydric alcohols such as ethylene glycol, propylene glycol, trimethylolpropane and hexanetriol at an NCO / OH ratio of 2 or more may also be used as the block polyisocyanate curing agent.

  Preferred specific examples of the aliphatic polyisocyanate or alicyclic polyisocyanate include hexamethylene diisocyanate, hydrogenated TDI, hydrogenated MDI, hydrogenated XDI, IPDI, norbornane diisocyanate, their dimer (biuret), and trimer. (Isocyanurate) etc. are mentioned.

  The blocking agent is added to a polyisocyanate group and is stable at ordinary temperature, but can regenerate a free isocyanate group when heated to a temperature higher than the dissociation temperature.

  As the blocking agent, when low temperature curing (160 ° C. or lower) is desired, lactam blocking agents such as ε-caprolactam, δ-valerolactam, γ-butyrolactam and β-propiolactam, and formaldoxime, acetoald It is preferable to use an oxime blocking agent such as oxime, acetoxime, methyl ethyl ketoxime, diacetyl monooxime, and cyclohexane oxime.

Pigment (b)
The cationic electrodeposition coating composition of the present invention contains a commonly used pigment. As the pigment, an inorganic pigment, an organic pigment, carbon black or a combination thereof is contained. As inorganic pigments, for example, colored pigments such as titanium white, carbon black and bengara, extender pigments such as kaolin, talc, aluminum silicate, calcium carbonate, mica, clay and silica, zinc phosphate, iron phosphate, phosphorus Anti-corrosive pigments such as aluminum phosphate, calcium phosphate, zinc phosphite, zinc cyanide, zinc oxide, aluminum tripolyphosphate, zinc molybdate, aluminum molybdate, calcium molybdate and aluminum phosphomolybdate, aluminum phosphomolybdate Is mentioned. In the present specification, the “organic pigment” is used in the concept of contrasting with an inorganic pigment. Examples of organic pigments include phthalocyanine blue, phthalocyanine green, monoazo yellow, disazo yellow, benzimidazolone yellow, quinacridone red, monoazo red, boriazo red, and berylene red.

  In the present invention, any of the above pigments can be used. These may be used alone or in combination of two or more. For example, by using titanium oxide which is a color pigment, an electrodeposition coating composition having high whiteness and high hiding power can be obtained, and an electrodeposition coating composition having excellent sedimentation stability can be produced. In addition, for example, by using silica or kaolin as an extender pigment, it is possible to improve repellency prevention, chipping resistance, coating film hardness, weather resistance, adhesion, etc., and coating film with improved rust prevention properties. An electrodeposition coating film having excellent physical properties and performance can be obtained, and an electrodeposition coating composition having excellent sedimentation stability can be produced. Furthermore, for example, by using aluminum phosphate or calcium molybdate that is a rust preventive pigment, it is possible to obtain an electrodeposited coating film that has improved coating film rust prevention properties and excellent coating physical properties, and is stable in sedimentation. A cationic electrodeposition coating composition having excellent properties can be produced.

  The pigment is generally contained in the cationic electrodeposition coating composition in an amount that occupies a lower limit of 1% by weight and an upper limit of 60% by weight with respect to the total solid content of the cationic electrodeposition coating composition. The upper limit is preferably 30% by weight.

Curing Catalyst In the cationic electrodeposition coating composition of the present invention, a curing catalyst can be added to promote dissociation of the blocking agent of the blocked polyisocyanate curing agent. The curing catalyst used in the present invention is not particularly limited as long as it promotes dissociation of the blocking agent of the curing agent, and a typical catalyst includes a tin catalyst. Examples of the tin catalyst include solid catalysts such as dibutyltin oxide, dioctyltin oxide, monobutyltin oxide and mixtures thereof, liquid tin catalysts such as dibutyltin dilaurate, and mixtures thereof.

  The said curing catalyst is mix | blended in the quantity of 0.5-10 mass% with respect to the resin solid content in an electrodeposition coating material, Preferably it is 1-5 mass%.

Cationic Acrylic Resin The cationic electrodeposition coating composition of the present invention preferably contains a cationic acrylic resin. By including this, it is possible to prevent a decrease in oil repellency that may occur when the content of the inorganic pigment is low. The cationic acrylic resin can be produced by a ring-opening addition reaction between an acrylic copolymer containing a plurality of oxirane rings in the molecule and an amine. Such acrylic polymers include (i) glycidyl (meth) acrylate and (ii) hydroxyl group-containing acrylic monomers such as 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, Plaxel FA and FM It is obtained by copolymerizing an addition reaction product of 2-hydroxyethyl (meth) acrylate and caprolactone known as a series with (iii) other acrylic and / or non-acrylic monomers. Examples of other acrylic and non-acrylic monomers are methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) ) Acrylate, t-butyl (meth) acrylate, cyclohexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, styrene, vinyl ketone, α-methylstyrene, (meth) acrylonitrile, (meth) acrylamide, Such as vinyl acetate.

  This oxy ring-containing acrylic resin is composed of a primary amine, a secondary amine or a tertiary amine acid in the same manner as when the oxirane ring of an epoxy resin is opened with an amine to introduce a cationic group. The ring can be opened by reaction with a salt to form a cationic acrylic resin.

  As another method, a cationic acrylic resin can be directly produced by copolymerizing an acrylic monomer having an amino group with another monomer. In this case, N, N-dimethylaminoethyl (meth) acrylate, N, N-di-t-butylaminoethyl (meth) instead of glycidyl (meth) acrylate previously used for the production of the oxirane ring-containing acrylic resin. Cationic acrylic resins are obtained directly by using acrylic monomers containing amino groups such as acrylates and copolymerizing them with acrylic monomers containing hydroxyl groups and other acrylic and / or non-acrylic monomers.

  The cationic acrylic resin is a conventional method so that the number average molecular weight of the polymer is in the range of 1,000 to 20,000, preferably 2,000 to 10,000, more preferably 5,000 to 10,000. Can be obtained by copolymerizing the monomers.

  The compounding quantity of a cationic acrylic resin is 10-100 weight part with respect to 100 weight part of resin solid content in an electrodeposition coating material.

Pigment settling inhibitor (a)
The cationic electrodeposition coating composition of the present invention is an anti-settling pigment pigment selected from the group consisting of fatty acids, fatty acid derivatives (both are referred to as fatty acids), amine compounds and mixtures of one or more of them. Contains agents. In the present invention, the dispersion stability of the pigment contained in the coating composition is improved by adding the pigment anti-settling agent (a) to the electrodeposition coating composition. And even if it is an electrodeposition coating composition containing an inorganic pigment, a coating composition with few pigment deposits can be manufactured even if an electrodeposition coating is left still.

  The fatty acids are fatty acids or derivatives thereof as described above. Examples of fatty acids include linear saturated fatty acids, branched saturated fatty acids, and unsaturated fatty acids. Examples of fatty acid derivatives include fatty acid esters obtained by modifying the above fatty acids with alcohols, polyhydric alcohols (glycerin, ethylene glycol, polyethylene glycol, etc.), fatty acid ethylene oxide adducts or fatty acid propylene oxides modified with ethylene oxide or propylene oxide. Adducts, fatty acid amide compounds modified with amine compounds, and polyfunctional fatty acids are included. These fatty acid esters or fatty acid amide compounds also include those obtained by ring-opening addition of ethylene oxide (ethylene oxide ring-opening adduct). These fatty acids contain chemical bonds such as unsaturated bonds, ether bonds and ester bonds, functional groups such as hydroxyl groups, amino groups and carbonyl groups, and heteroatoms such as oxygen, nitrogen, sulfur and halogen in the molecular skeleton. You may go out. Polyfunctional carboxylic acids and the like are also included in the fatty acid derivatives. As fatty acid derivatives, it is more preferable to use fatty acid esters, fatty acid amide compounds, and these ethylene oxide ring-opening adducts.

  The fatty acids used in the present invention are preferably fatty acids having 4 to 22 carbon atoms and derivatives thereof, more preferably fatty acids having 7 to 20 carbon atoms and derivatives thereof.

Specific fatty acids include, for example, the following compounds:
(1) linear saturated fatty acid arachidic acid, tricosanoic acid, behenic acid, heneicosanoic acid, eicosanoic acid, nonadecanoic acid, stearic acid, heptadecanoic acid, palmitic acid, pentadecanoic acid, myristic acid, tridecanoic acid, lauric acid, capric acid, capryl Acid, octanoic acid, heptanoic acid, hexanoic acid, valeric acid, butyric acid, etc., refined stearic acid (450V, 550V, 700V), etc. manufactured by Kao Corporation;
(2) Branched saturated fatty acid isostearic acid, methyltetradecanoic acid, methylheptadecanoic acid, methyloctadecanoic acid, isovaleric acid and the like;
(3) unsaturated fatty acid oleic acid, ricinoleic acid, linoleic acid, linolenic acid, eleostearic acid, elaidic acid, palmitoleic acid, arachidonic acid, undecenoic acid, sorbic acid, crotonic acid and the like;
(4) Multifunctional carboxylic acid suberic acid, azelaic acid, sebacic acid, brassylic acid, phthalic acid, dodecanedioic acid, tetrahydrophthalic acid, hexahydrophthalic acid, tetrabromophthalic acid, tetrachlorophthalic acid, 3-tert-butyl Adipic acid, trimellitic acid, pyromellitic acid, etc .;
(5) Hetero atom-containing fatty acid hexyloxyacetic acid, dimethylolpropionic acid, dimethylolbutanoic acid, salicylic acid, benzoic acid, p-butoxybenzoic acid, N-acetylglycine, N-acetyl-β-alanine, thioctic acid and the like;
(6) Fatty acid ester (alcohol ester type)
Lion's Kadenax (GS-90, SO-80C), Kao's Rheodor (SP-L10, SP-P10, SP-S10V, SP-S30V, AS-10, AO-10, AO-15V), Kao Rheodor Super SP-L10 manufactured by Kao, Emazol manufactured by Kao Corporation (L-10 (F), P-10 (F), S-10V, O-10V), etc .;
(7) Fatty acid ester (ethylene glycol, polyethylene glycol ester type)
Lion Rionon (DT-600S, DEH-40), Asahi Denka Kogyo Adekaestor (OEG-102, OEG-106), etc .;
(8) Fatty acid methyl ester (ethylene oxide, propylene oxide addition system)
Lion Leo Fat (LA-110M-95, OC-0503M), Kao Emanon (1112,3199,3299,4110, CH-25, CH-40, CH-60 (K), CH-80), etc. (9) Fatty acid ethylene oxide adducts Lion's Esophat (O / 15, O / 20,60 / 15), Asahi Denka Kogyo's Adekaestor (TL-144, TL-161, TL-162, S-60, S-80, T-81, T-82), Kao Rheodor (TW-L120, TW-L106, TW-P120, TW-S120V, TW-S106, TW-S320V, TW-O120V, TW-O106V, TW-O320V, TW-IS399C, 430,440,460), Kao's Leodoll Super TW-L120, etc .;
(10) Fatty acid ester (glycerin ester type)
(11) Fatty acid amide compounds such as Kao's Exel T-95, VS-95, O-95R, 200, 300, 122V, P-40S) and Kao's Rheodor (MS-50, MS-60, MO-60, MS165V) A saturated fatty acid monoamide compound that is lauric acid amide, stearic acid amide, palmitic acid amide, caproic acid amide, caprylic acid amide, capric acid amide, myristic acid amide, stearic acid amide, behenic acid amide, hydroxystearic acid amide and the like;
(12) Unsaturated fatty acid monoamide oleic acid amide, erucic acid amide, ricinoleic acid amide, palmitic acid amide, behenic acid amide, brassinic acid amide, esylic acid amide, linoleic acid amide, linolenic acid amide, rice sugar Examples of these industrial products such as fatty acid amide and palm fatty acid amide include Kao wax (EB-G, EB-P, EB-FF, 85-P, 220, 230-2) manufactured by Kao Corporation, and fatty acid amide manufactured by Kao Corporation. S, T, ON, E), Adekasol YA manufactured by Asahi Denka Kogyo Co., Ltd. and the like;
(13) Saturated fatty acid bisamides that are fatty acid amide compounds, methylene bis-stearic acid amide, ethylene bis-capric acid amide, ethylene bis-lauric acid amide, ethylene bis-stearic acid amide, ethylene bis-isostearic acid amide, ethylene bis-hydroxystearic acid amide, ethylene Bisbehenic acid amide, hexamethylene bisstearic acid amide, hexamethylene bisbehenic acid amide, hexamethylene bishydroxystearic acid amide, N, N′-distearyl adipic acid amide, N, N′-distearyl sebacic acid amide, methylene Bispalmitic acid amide, ethylene bispalmitic acid amide, methylene bisbehenic acid amide, ethylene bisbehenic acid amide, hexaethylene bispalmitic acid amide, etc .;
(14) Unsaturated fatty acid bisamides that are fatty acid amide compounds, ethylene bisoleic acid amide, hexamethylene bisoleic acid amide, N, N′-dioleyl adipic acid amide, N, N′-dioleyl sebacic acid amide, and the like;
(15) Substituted amides which are fatty acid amide compounds N-stearyl stearic acid amide, N-oleyl oleic acid amide, N-stearyl oleic acid amide, N-oleyl stearic acid amide, N-stearyl erucic acid amide, N-oleyl palmitic acid Acid amides;
(16) Aromatic bisamides methylol stearic acid amides which are fatty acid amide compounds; methylol amides such as methylol behenic acid amide, N, N-distearylisophthalic acid amide, metaxylylene bis stearic acid amide;
(18) Branched amides which are fatty acid amide compounds N′-2-hydroxyethyl stearamide, N.I. N'-ethylenebisoleic acid amide, N.I. N'-xylenebisstearic acid amide, N.I. N′-dioleoyl adipate amide, N.I. N′-dioleoyl sebacic acid amide, N.I. N′-distearyl isophthalic acid amide, etc.
(19) Alkanolamides which are fatty acid amide compounds: coconut oil fatty acid monoethanolamide, lauric acid monoethanolamide, myristic acid monoethanolamide, oleic acid monoethanolamide, coconut oil fatty acid diethanolamide, lauric acid diethanolamide, myristic acid diethanolamide Industrial products such as lime, dioleamide, oleic acid diethanolamide, palm oil fatty acid monopropanolamide, lauric acid monopropanolamide, myristic acid monopropanolamide, oleic acid monopropanolamide, polyoxyalkylene alkanolamide ), Lion's armor slip (CP, E, EY), etc .;
However, it is not limited to these.

  The amine compound is preferably an amine compound in which an alkyl chain having 4 or more carbon atoms is bonded to a nitrogen atom. There may be one alkyl chain bonded to the nitrogen atom, or two or more alkyl chains may be bonded. As these amine compounds, any of primary, secondary and tertiary amines may be used. These amine compounds may have a plurality of amino groups in the skeleton, or the skeleton itself may be modified with ethylene oxide or the like. The amine compound used in the present invention preferably has 4 to 22 carbon atoms in the alkyl chain, more preferably 7 to 20 carbon atoms in the alkyl chain.

Specific examples of amine compounds include the following:
(1) Primary amine compound (1-1) Aliphatic mono- and polyamine compounds
n-butylamine, amylamine, n-hexylamine, heptylamine, n-octylamine, nonylamine, laurylamine, tetradecylamine, cetylamine, stearylamine, 2,4-butanediamine, 1,6-hexamethylenediamine, 1, Aliphatic primary amine compounds such as 8-octamethylenediamine,
(1-2) Alicyclic mono- and polyamine compounds cyclohexylamine, 1,3- and 1,4-diaminocyclohexane, 1,3- and 1,4-bis (aminomethyl) cyclohexane, 3-aminomethyl-3, Alicyclic primary amine compounds such as 5,5-trimethyl-1-aminocyclohexane, bis (4-aminocyclohexyl) methane, 1-methyl-2,4-diaminocyclohexane, 1-methyl-2,6-diaminocyclohexane Kind,
(1-3) Aromatic mono- and polyamine compounds aniline, meta and paratoluidine, naphthylamine, 1,3- and 1,4-phenylenediamine, 1-methyl-2,4-diaminobenzene, 1-methyl-2,6 -Aromatic primary amine compounds such as diaminobenzene, 2,4,-and 4,4, -diaminodiphenylmethane, 4,4, -diaminobiphenyl, 1,5- and 2,6-naphthalenediamine,
(1-4) Aralkyl mono and polyamine compounds
Aralkyl primary amine compounds such as 1,3- and 1,4-bis (aminomethyl) benzene, 1,5- and 2,6-bis (aminomethyl) naphthalene,
These industrial products include Lion's Armin CD, OD, TD, HT, 8D, 12D, 14D, 16D, 18D), Kao's Farmin (CS, 08D, 20D, 80, 86T, O, T), etc. Listed;
(2) Secondary amine compounds di-n-butylamine, diisoamylamine, dibenzylamine, methyldiethylethylenediamine, methylaniline, piperidine, 1,2,3,4-tetrahydroisoquinoline, 6-methoxy-1,2,3 Secondary amines such as, 4-tetrahydroisoquinoline, morpholine, N-methyl-glucamine, glucosamine, t-butylamine,
These industrial products include Kao's Farmin (D86) and the like;
(3) tertiary amine compounds such as tri (n-butyl) amine, tetramethylethylenediamine, 1-methylpiperidine, 1-methylpyrrolidine, 4-dimethylaminopyridine, triethylenediamine, bisdimethylaminoethyl ether, triisopropanolamine, etc. Grade amines,
These industrial products include Lion's Armin (DMMCD, DMTD, DMMHTD, DM12D, DM14D, DM16D, DM18D, DM22D, M2HT, M2O, M210D), Kao's Farmin (DM24C, DM0898, DM1098, DM2098, DM2465, DM2463) DM2458, DM4098, DM4662, DM6098, DM6875, DM8680, DM8098, DM2285, M2-2095, T-08) and the like;
(4) Alkanolamine Kao Aminone (PK-02S, L-02), etc .;
(5) Modified amine (5-1) Alkylamine Ethylene oxide adduct Lion Esomin (C / 12, C / 15, C / 25, T / 12, T / 15, T / 25, S / 15, S / 25, O / 12, O / 17, O / 20, HT / 12, HT / 14, HT / 17), Lion esomide (HT / 15, HT / 60, O / 15), Asahi Denka Kogyo Co., Ltd. Made Adekasol (CO, COA, CMA, YA-6), Kao Amit (105,320);
However, it is not limited to these.

  These fatty acids and amine compounds may be used either alone or in combination of two or more.

  Although the mechanism of action by which the dispersibility of the pigment is improved by adding a fatty acid or an amine compound is not clear, for example, the arrangement of a structure of a monomolecular film or a structure of a bimolecular film of a fatty acid with respect to the pigment Therefore, it is considered that this increases the resistance of the pigment to water and prevents the pigment from settling. The fatty acids or amine compounds used in the present invention have a high ability to be arranged in a structure such as a molecular film, and are excellent in the performance of preventing the precipitation of the pigment.

  The pigment settling inhibitor (a) is contained in the electrodeposition coating composition in an amount occupying the lower limit of 0.1 part by weight and the upper limit of 20 parts by weight with respect to 100 parts by weight of the pigment contained in the electrodeposition coating composition. The lower limit is preferably 0.5 parts by weight, and more preferably 1 part by weight. The upper limit is preferably 15 parts by weight, and more preferably 10 parts by weight.

When a cationic pigment dispersion paste pigment is used as a component of an electrodeposition paint, generally, the pigment is dispersed in an aqueous medium at a high concentration together with a resin called a pigment dispersion resin to make a paste. This is because the pigment is in a powder form, and it is difficult to disperse in a single step in a low concentration uniform state used in the electrodeposition coating composition. Such a paste is generally called a pigment dispersion paste. When a catalyst is used, it may be added when preparing this pigment dispersion paste, or the catalyst may be added in another paint manufacturing process.

  As the cationic pigment dispersion resin varnish, generally, a cationic or nonionic low molecular weight surfactant, a modified epoxy resin having a quaternary ammonium group and / or a tertiary sulfonium group, or the like is used. As the aqueous medium, ion-exchanged water or water containing a small amount of alcohol is used. Generally, the pigment-dispersed resin varnish is used in a solid content of 20 to 40 parts by mass, and the pigment and tin catalyst are used in a ratio of 60 to 80 parts by mass.

Cationic electrodeposition coating composition The cationic electrodeposition coating composition of the present invention comprises a cationic resin and a block polyisocyanate curing agent dispersed in an aqueous medium (cationic main emulsion), a cationic acrylic resin and a block polyisocyanate. It is prepared by mixing a hardener dispersed in an aqueous medium (subemulsion), a pigment dispersion paste, and deionized water at a predetermined ratio.

  In the preparation of the electrodeposition coating composition of the present invention, the pigment settling inhibitor (a) can be added at any dispersion / mixing stage. The pigment settling inhibitor (a) is preferably added to the above-mentioned cationic pigment dispersion paste and then mixed with other components such as a cationic main emulsion. In this case, it is because it is excellent in the performance which prevents sedimentation of a pigment.

  As the aqueous medium, ion-exchanged water or water containing a small amount of alcohol is used. The aqueous medium contains a neutralizing agent in order to improve the dispersibility of the cationic resin. Neutralizing agents are inorganic or organic acids such as hydrochloric acid, nitric acid, phosphoric acid, formic acid, acetic acid, lactic acid. The amount is that which achieves a neutralization rate of at least 20%, preferably 30-60%.

  The amount of the block polyisocyanate curing agent is sufficient to react with active hydrogen-containing functional groups such as primary, secondary or / and tertiary amino groups and hydroxyl groups in the cationic resin during curing to give a good cured coating film. It should be sufficient and generally ranges from 90/10 to 50/50, preferably 80/20 to 65/35, expressed as a weight ratio of cationic resin to blocked polyisocyanate curing agent.

  The electrodeposition paint can contain conventional paint additives such as water-miscible organic solvents, surfactants, antioxidants, and UV absorbers.

  The electrodeposition coating composition of the present invention is electrodeposited onto an article by a method well known to those skilled in the art to form a cured coating film. The object to be coated when performing electrodeposition coating using this cationic electrodeposition coating composition is preferably a conductor that has been subjected to surface treatment such as zinc phosphate treatment in advance by dipping, spraying method, etc. The surface treatment may not be performed. In addition, the conductor is not particularly limited as long as it can become a cathode in performing electrodeposition coating, and a metal substrate is preferable.

The conditions under which electrodeposition is performed are generally the same as those used for other types of electrodeposition coating. The applied voltage may vary greatly and may range from 1 volt to several hundred volts. The current density is usually about 10 amperes / m ^{2 to} 160 amperes / m ² and tends to decrease during electrodeposition.

  After electrodeposition, the coating is baked at normal temperature, for example, in a baking furnace, in an oven or with an infrared heat lamp. The baking temperature may vary but is usually about 140 ° C to 180 ° C.

Anionic electrodeposition coating composition The electrodeposition coating composition of the present invention may be an anionic electrodeposition coating composition. Hereinafter, the anionic case will be described.

  The anionic electrodeposition coating composition of the present invention can be formed by replacing the cationic resins of the cationic electrodeposition coating composition with anionic. Hereinafter, only parts different from the cationic electrodeposition coating composition will be described.

In the anionic resin anionic electrodeposition coating composition, an anionic resin is used instead of the cationic resin. As the anionic resin used in the present invention, a resin having a carboxyl group and optionally further a hydroxyl group, which is well known in the field of electrodeposition coating, can be used. As the anionic resin, for example, an acrylic resin having a carboxyl group or a polyurethane resin having a carboxyl group is preferably used, and an acrylic resin having a carboxyl group and a hydroxyl group or a polyurethane resin having a carboxyl group and a hydroxyl group is particularly preferably used. This is because the coating film is excellent in weather resistance and smoothness.

  Examples of the acrylic resin having a carboxyl group and a hydroxyl group include, for example, a carboxyl group-containing unsaturated monomer, a hydroxyl group-containing acrylic monomer, and, if necessary, other polymerizable monomers. A copolymer obtained by radical polymerization of a monomer can be used.

  The carboxyl group-containing unsaturated monomer is a compound having at least one carboxyl group and polymerizable unsaturated bond in one molecule, for example, (meth) acrylic acid, itaconic acid, maleic acid, caprolactone-modified carboxyl group Examples thereof include (meth) acrylic monomers.

  A hydroxyl group-containing acrylic monomer is a compound having at least one hydroxyl group and a polymerizable unsaturated bond in one molecule. For example, hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meta ) Hydroxyalkyl (meth) acrylates such as acrylates; (poly) ethylene glycol mono (meth) acrylates, (poly) alkylene glycol mono (meth) acrylates such as (poly) propylene glycol mono (meth) acrylates; Monomers and β-propiolactone, dimethylpropiolactone, butyrolactone, γ-valerolactone, γ-caprolactone, γ-caprolactone, γ-laurolactone, ε-caprolactone, δ-caprolactone, etc. Examples of commercially available products include Plaxel FM1 (trade name, caprolactone-modified (meth) acrylic acid hydroxyesters), Plaxel FM2 (same as left), and Placcel FM3 (same as left). ), Plaxel FA1 (same as left), Plaxel FA2 (same as left), Plaxel FA3 (same as left), and the like.

The other polymerizable monomer is a compound having at least one polymerizable unsaturated bond in one molecule other than the above carboxyl group-containing unsaturated monomer and hydroxyl group-containing acrylic monomer, For example, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, hexyl (meth) acrylate, octyl (meth) acrylate, lauryl (meth) acrylate , (meth) alkyl or cycloalkyl esters of C ₁ -C ₁₈ (meth) acrylic acid such as cyclohexyl acrylate; styrene, alpha-methyl styrene, aromatic polymerizable monomers such as vinyl toluene; (meth) acrylic (Meth) acrylamido such as acid amide, N-butoxymethyl (meth) acrylamide, N-methylol (meth) acrylamide And derivatives thereof; (meth) acrylonitrile compounds; γ- (meth) acryloxypropyltrimethoxysilane, γ- (meth) acryloxypropylmethyldimethoxysilane, γ- (meth) acryloxypropyltriethoxysilane, vinyltrimethoxy Examples include alkoxysilyl group-containing polymerizable monomers such as silane.

  As a blending ratio of these monomers, it is preferable to use the carboxyl group-containing unsaturated monomer within the range of 3 to 30% by weight, particularly 4 to 20% by weight, based on the total weight of the monomers. The hydroxyl group-containing acrylic monomer is preferably used in the range of 3 to 40% by weight, particularly 5 to 30% by weight, based on the total weight of the monomers.

  A conventionally known solution polymerization method or the like can be adopted as a method for radically copolymerizing these monomers.

  Examples of the polyurethane resin having a carboxyl group and a hydroxyl group include those obtained by subjecting a polyisocyanate compound, polyols and dihydroxycarboxylic acid to a urethanization reaction by an equivalent ratio of excess hydroxyl group by a one-shot method or a multistage method. It is done.

  The polyisocyanate compound is a compound having two or more isocyanate groups in one molecule, and examples thereof include aliphatic diisocyanates such as hexamethylene diisocyanate, trimethylhexane diisocyanate, and lysine diisocyanate; cyclohexane diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate, and methylcyclohexyl. An alicyclic diisocyanate such as silylene diisocyanate is preferably used.

  Polyols are compounds having two or more hydroxyl groups in one molecule, for example, polymerization or copolymerization (blocking) of alkylene oxide (ethylene oxide, propylene oxide, butylene oxide, etc.) and / or heterocyclic ether (tetrahydrofuran). Or random) polyether diols obtained by, for example, polyethylene glycol, polypropylene glycol, polyethylene-propylene (block or random) glycol, polytetramethylene ether glycol, polyhexamethylene ether glycol, polyoctamethylene ether glycol, etc .; dicarboxylic acid (Adipic acid, succinic acid, sebacic acid, glutaric acid, maleic acid, fumaric acid, phthalic acid, etc.) and glycol (ethylene glycol, propylene glycol, Diol, hexanediol, neopentyl glycol, bishydroxymethylcyclohexane and the like) polyester diols obtained by condensation polymerization such as polyethylene adipate, polybutylene adipate, polyhexamethylene adipate, polyneopentyl adipate, polyethylene-butylene adipate, Examples include polyneopentyl-hexyl adipate and the like; polylactone diols such as polycaprolactone diol and poly-3-methylvalerolactone diol; polycarbonate diols; a mixture of two or more selected from these. These polyols can generally have a number average molecular weight in the range of 500 or more, preferably 500 to 5000, more preferably 1000 to 3000.

  As the polyols, low molecular weight polyols having two or more hydroxyl groups in one molecule and having a number average molecular weight of less than 500 can also be used. Specifically, glycols and their alkylene oxide low molar adducts (molecular weight less than 500) mentioned above as raw materials for polyester diols; trihydric alcohols such as glycerin, trimethylolethane, trimethylolpropane and the like and their low alkylene oxides. Mole adduct (molecular weight less than 500); a mixture of two or more selected from these, and the like.

  In a system in which a polyol having a number average molecular weight of 500 or more and a low molecular weight polyol having a number average molecular weight of less than 500 are used in combination, the composition ratio of these two polyols is 80 based on the total amount of both polyols. ˜99.9% by weight, in particular 90 to 99.5% by weight, the latter being preferably in the range of 20 to 0.1% by weight, in particular 10 to 0.5% by weight.

  Dihydroxycarboxylic acid is a compound having two hydroxyl groups and one carboxyl group in one molecule, and examples thereof include dimethylolacetic acid, dimethylolpropionic acid, dimethylolbutyric acid, and dimethylolbutanoic acid.

  The urethanation reaction with the polyisocyanate compound, polyols and dihydroxycarboxylic acid described above can be carried out by a method known per se.

In the curing agent anionic electrodeposition coating composition, examples of the curing agent for the anionic resin include melamine resin and block polyisocyanate.

As the melamine resin, ether in which part or all of the methylol group of methylolmelamine obtained by reacting melamine with formaldehyde or the like is modified with one or more alcohols selected from C _{1 to} C ₁₀ monoalcohols. A melamine resin can be used. The melamine resin may contain an imino group, a methylol group, or other functional groups.

  As the block polyisocyanate, the block polyisocyanate curing agent exemplified in the above cationic electrodeposition coating composition can be used.

Pigment settling inhibitor (a)
The pigment anti-settling agent (a) used in the anionic electrodeposition coating composition is the same as that in the cationic electrodeposition coating composition.

When the anionic pigment-dispersed paste electrodeposition paint contains a pigment, it is preferable to prepare the pigment in the form of a pigment-dispersed paste from the viewpoint of easy dispersion of the pigment. An anionic pigment dispersion paste can be prepared by dispersing a pigment in an anionic pigment dispersion resin. As the pigment, the pigments exemplified in the above cationic electrodeposition coating composition can be used.

  For example, a modified acrylic resin having an acrylic ester, acrylic acid and an azonitrile compound can be used as the anionic pigment dispersion resin. As the aqueous medium, the above-mentioned aqueous medium, for example, ion exchange water or the like is used.

  An anionic pigment dispersion paste can be prepared by adding the above-mentioned anionic pigment dispersion resin, a pigment and a neutralizing agent, and dispersing or dissolving them.

  Generally, the anionic pigment dispersion paste is prepared to a solid content of 35 to 70% by weight, preferably 40 to 65% by weight.

  An anionic pigment dispersion paste is prepared by mixing an anionic pigment dispersion resin and a pigment, and, if necessary, a neutralizing agent such as triethylamine and an aqueous medium, and then the pigment in the mixture has a predetermined uniform particle size. Until it becomes, it can disperse | distribute and obtain using normal dispersion apparatuses, such as a ball mill and a sand grind mill.

Preparation of anionic electrodeposition coating composition The anionic electrodeposition coating composition of the present invention is prepared by dispersing the above-mentioned anionic resin and anionic pigment dispersion paste in an aqueous medium. Usually, the aqueous medium contains a neutralized base (amine or alkali compound) in order to neutralize the anionic resin and improve the dispersibility. Specifically, the amine used as the neutralizing base has a low molecular weight having 3 or less carbon atoms, and is different from the above-described pigment settling inhibitor. When the number of carbon atoms is such, the interaction with the resin becomes larger than the interaction with the pigment, so that the effect of the pigment as an anti-settling agent is lost. Examples of neutralizing bases include ammonia; diethylamine, ethylethanolamine, diethanolamine, monoethanolamine, monopropanolamine, isopropanolamine, ethylaminoethylamine, hydroxyethylamine, diethylenetriamine and other organic amines; sodium hydroxide, potassium hydroxide, etc. Basic compounds such as alkali metal hydroxides. The aqueous medium is water or a mixture of water and the above organic solvent. It is preferable to use ion exchange water as water.

  In the preparation of the anionic electrodeposition coating composition of the present invention, the pigment settling inhibitor (a) can be added at any dispersion / mixing stage. The pigment settling inhibitor (a) is preferably added to the anionic pigment dispersion paste and then mixed with other components such as an anionic main emulsion. In this case, it is because it is excellent in the performance which prevents sedimentation of a pigment. In addition, the compounding quantity of a fatty acid or an amine compound is the same as the case of a cationic electrodeposition coating composition.

  The amount of the curing agent is generally 90/10 to 50/50, preferably in the range of 80/20 to 50/50, expressed as a solid weight ratio (anionic resin / curing agent) between the anionic resin and the curing agent. is there. The amount of neutralizing base is that which is sufficient to neutralize at least 30%, preferably 50-120% of the anionic groups of the anionic resin.

  The electrodeposition coating of the anion electrodeposition coating composition is usually performed by applying a voltage of 1 to 400 V between the object to be coated as the anode and the cathode. During electrodeposition coating, the bath temperature of the coating composition is adjusted to 10 to 45 ° C, preferably 15 to 30 ° C, and pH is adjusted to 6.0 to 9.0, preferably 7.0 to 8.0.

  The electrodeposition process includes a process of immersing a coating object in the anionic electrodeposition coating composition, and a process of depositing a film by applying a voltage between the coating object as an anode and a cathode. Moreover, although the voltage application time varies depending on the electrodeposition conditions, it can generally be set to 30 seconds to 5 minutes. After completion of the electrodeposition process, the cured coating film is obtained by baking at 100 to 200 ° C., preferably 120 to 180 ° C., for 10 to 60 minutes as it is or after washing with water.

The obtained film thickness is preferably 5 to 30 μm, particularly 7 to 20 μm, as a cured coating film.

  The electrodeposition coating composition of the present invention has very little sedimentation of the pigment component even if the stirring of the electrodeposition bath is stopped, so there is no problem even if the stirring of the electrodeposition bath is stopped when not coated. However, it is preferable to stir in the tank in order to remove the reaction gas generated during deposition of the coating during electrodeposition coating or to diffuse reaction heat generated during deposition of the coating. With conventional paints, it is necessary to stir the electrodeposition bath even when it is not painted. However, since the electrodeposition paint of the present invention can stop stirring when it is not painted at night, on holidays, etc., It is possible to significantly reduce the electric energy cost required for stirring the bath.

  As shown in FIG. 1, stirring of the electrodeposition bath is generally performed by taking a part of the electrodeposition bath and returning it to the electrodeposition bath using a pump. In the figure, the electrodeposition bath 1 is provided with an overflow tank 2, and the electrodeposition paint is present in both tanks. A part of the electrodeposition bath 1 and a part of the overflow tank are also sent to the pump 3 and returned to the electrodeposition bath through the filter 4, but at this time, ejected from the nozzle 6 of the riser 5 in the electrodeposition bath 1. And stir. However, of course, it is not limited to this method.

  For example, as shown in FIG. 2, a method of inserting a blade for stirring (stirring blade 11) into the electrodeposition bath is also conceivable. In this case, it is not possible to use the circulation stirring system shown in FIG. Accordingly, only a stirring blade is required for the circulating stirring device, and the equipment cost and energy cost are greatly improved. As described above, the stirring itself is necessary for the removal of the reaction gas and the diffusion of the reaction heat, but simple stirring with stirring blades is sufficient during electrodeposition coating, and the coating composition of the present invention is used. If used, stirring can be stopped when not painted, which greatly contributes to a reduction in energy costs.

  Further, the circulating stirring as described in FIG. 1 is also performed in the management of a washing bath performed after electrodeposition. An example is schematically shown in FIG. In FIG. 3, 30 indicates an electrodeposition bath, 31 indicates a first water-washing bath, and 32 indicates a second water-washing bath. Part of the electrodeposition bath 30 is separated into moisture by an ultrafilter (UF) 33, the paint is returned to the electrodeposition bath 30, and the moisture is used in the washing baths (31 and 32). Usually, after the water is used in the second washing bath 32, a part thereof is returned to the first washing bath 31 and further returned to the electrodeposition bath 30. In both the first water-washing bath 31 and the second water-washing bath 32, stirring is performed by a circulation stirring system indicated by 34 and 35. This agitation is necessary to maintain the dispersed state because the electrodeposition paint is brought into the water-washing bath while adhering to the object. When the coating material of the present invention is used, the sedimentation is extremely less than that of the conventional electrodeposition coating material. Therefore, the conventional circulation stirring as shown in FIG. 3 is not particularly necessary, and the stirring blade 36 as shown in FIG. The agitation used is sufficient, greatly reducing equipment costs and energy costs.

  The present invention will be described in more detail with reference to examples. The present invention should not be construed as limited to these examples. In these examples, “parts” and “%” are by weight unless otherwise specified.

Production Example 1
Preparation of cationic resin A reaction vessel equipped with a stirrer, a cooling tube, a nitrogen introduction tube and a thermometer, 99.8 parts of Epicoat 1001 (Oilized Shell Epoxy, bisphenol A type epoxy resin having an epoxy equivalent of 475), Epicoat 1004 (manufactured by Yuka Shell Epoxy, bisphenol A type epoxy resin having an epoxy equivalent of 950) 850.2 parts, 55 parts of nonylphenol, 193.3 parts of methyl isobutyl ketone (MIBK) and 4.5 g of benzyldimethylamine were added at 140 ° C. For 4 hours to obtain a resin having an epoxy equivalent of 1175. Here, 69.1 parts of ethylene glycol n-hexyl ether, 35.4 parts of MIBK solution (solid content 78% by weight) of MIBK ketimine product of 2-aminoethylethanolamine, 26.5 parts of N-methylethanolamine and 37 of diethanolamine 37 .1 part was added. This was reacted at 120 ° C. for 2 hours to obtain the desired resin. The SP of this cationic resin was 11.4.

Production Example 2
Preparation of cationic acrylic resin In a flask equipped with a stirrer, a cooling tube, a nitrogen introducing tube and a dropping funnel, 50.7 parts of styrene, 10.0 parts of methyl methacrylate, 20.1 parts of n-butyl acrylate, 2-hydroxyethyl A mixture of 10.2 parts of methacrylate, 9.2 parts of glycidyl methacrylate, and 4.0 parts of t-butyl peroctoate was dropped from a dropping funnel over 3 hours. After completion of dropping, the mixture was kept at 115 ° C. for about 1 hour, 0.5 part of t-butyl peroctoate was dropped, and kept at 115 ° C. for about 30 minutes to obtain a resin solution having a solid content of 65%. A resin solution having a number average molecular weight (Mn) of 5000 was obtained. After cooling, 5.1 parts of N-methylethanolamine was added thereto and reacted at 120 ° C. for 2 hours under a nitrogen atmosphere to obtain a cationic acrylic resin solution having a solid content of about 66%. The SP of this cationic acrylic resin was 9.7.

Production Example 3
Preparation of block polyisocyanate curing agent In a five-necked flask equipped with a reflux condenser, a stirrer, a dropping funnel and a nitrogen introduction tube, 199.1 parts of hexamethylene diisocyanate trimer (Coronate EH) and 31.6 of methyl isobutyl ketone The part was prepared and heated and held at 40 ° C. in a nitrogen atmosphere. To this was added 0.2 part of dibutyltin dilaurate, and further 87.0 parts of methylethylketoxime was added dropwise over 2 hours from the dropping funnel. After completion of the addition, the reaction was carried out at 70 ° C. until the peak of the isocyanate group disappeared by IR spectrum. It was. After completion of the reaction, 38.1 parts of methyl isobutyl ketone and 1.6 parts of butanol were added and cooled to obtain a block polyisocyanate crosslinking agent having a solid content of 80%.

Production Example 4
Preparation of Epoxy Resin Pigment Dispersion Resin 382 parts of Epicoat 828 and 118 parts of bisphenol A were placed in a reaction vessel and heated to 150 to 160 ° C. in a nitrogen atmosphere. The reaction mixture was reacted at 150-160 ° C. until the epoxy equivalent reached 500. Subsequently, after cooling the reaction mixture to 140 to 145 ° C., 203 parts of 2-ethylhexanol half-blocked toluene diisocyanate was added. The reaction mixture was kept at 140-145 ° C. for about 1 hour and then 209 parts dipropylene glycol monobutyl ether was added. Next, the reaction mixture was cooled to 90 ° C. or lower, and 272 parts of 1- (2-hydroxyethylthio) propan-2-ol, 134 parts of dimethylolpropionic acid, and 144 parts of deionized water were added. This mixture was reacted at 65 to 75 ° C. until an acid value of about 8 was obtained to obtain a pigment dispersing resin. This was cooled and diluted with deionized water to a solids content of 30% to obtain a varnish for pigment dispersion.

Production Example 5
Preparation of Cationic Main Emulsion The cationic resin of Production Example 1 and the polyisocyanate cross-linking agent of Production Example 3 were mixed as a solid content in a ratio of 70:30, neutralized with acetic acid to a neutralization rate of 40%, and deionized water Was added and diluted slowly, and then methyl isobutyl ketone and deionized water were removed so that the non-volatile content was 37% by mass to obtain a cationic main emulsion.

Production Example 6
Preparation of Cationic Acrylic Resin Emulsion In the same manner as in Production Example 5, an emulsion having a non-volatile content of 33% containing the cationic acrylic resin of Production Example 2 and the crosslinking agent of Production Example 3 in a ratio of 70:30 as a solid content was prepared. .

Production Example 7
Preparation of Cationic Pigment Paste A cationic pigment paste was prepared by dispersing the following blending amount.

  In the above table, carbon black: manufactured by Mitsubishi Chemical Corporation, MA-100, titanium oxide: manufactured by Ishihara Sangyo Co., Ltd., Type CR-97.

Example 1
35 parts by weight of the cationic main emulsion of Production Example 5, 4 parts by weight of the cationic acrylic resin emulsion of Production Example 6, 13.3 parts by weight of the cationic pigment dispersion paste of Production Example 7, and 47.4 parts by weight of deionized water Mixing was performed to obtain a cationic electrodeposition coating composition.

  The following settling test was performed on the obtained cationic electrodeposition coating composition. The cationic electrodeposition coating composition was poured into a test tube having a diameter of 20 mm to a height of 100 mm. The test tube was left to generate a precipitate. The thickness (mm) of the precipitate generated after 7 days of standing was measured and used as the amount of sediment. Table 2 shows the measured sedimentation amount (mm). Table 2 shows the nonvolatile content (% by weight) and pH of the electrodeposition coating composition.

  The obtained cationic electrodeposition coating composition was electrodeposited on a cold-rolled steel sheet treated with zinc phosphate, washed with water, and baked at 140 ° C. for 20 minutes. Table 2 shows the thickness of the obtained cured coating film. Further, the appearance of the cured coating film was visually evaluated. The case where no abnormality was observed was evaluated as “no abnormality”, and the case where abnormality could be visually confirmed was evaluated as “abnormal”.

Example 2
A cationic electrodeposition coating composition was prepared in the same manner as in Example 1 except that 5 parts by weight of heptanoic acid was used instead of 1 part by weight of heptanoic acid in the production of the cationic pigment dispersion paste of Production Example 7. Evaluation was performed in the same manner as in Example 1 using the obtained coating composition. The obtained results are shown in Table 2.

Example 3
A cationic electrodeposition coating composition was prepared in the same manner as in Example 1 except that 2 parts by weight of caprylic acid was used instead of 1 part by weight of heptanoic acid in the production of the cationic pigment dispersion paste of Production Example 7. Evaluation was performed in the same manner as in Example 1 using the obtained coating composition. The obtained results are shown in Table 2.

Example 4
Example 1 with the exception that 2 parts by weight of CADENAX GS-90 (produced by Lion Corporation, alcohol ester fatty acid ester) was used instead of 1 part by weight of heptanoic acid in the production of the cationic pigment dispersion paste of Production Example 7. Similarly, a cationic electrodeposition coating composition was prepared. Evaluation was performed in the same manner as in Example 1 using the obtained coating composition. The obtained results are shown in Table 2.

Example 5
Example 1 except that 5 parts by weight of Kadenax GS-90 (produced by Lion Corporation, alcohol ester fatty acid ester) was used instead of 1 part by weight of heptanoic acid in the production of the cationic pigment dispersion paste of Production Example 7. Similarly, a cationic electrodeposition coating composition was prepared. Evaluation was performed in the same manner as in Example 1 using the obtained coating composition. The obtained results are shown in Table 2.

Example 6
Example 1 with the exception that 2 parts by weight of Kao wax EB-G (unsaturated fatty acid monoamide) was used in place of 1 part by weight of heptanoic acid in the production of the cationic pigment dispersion paste of Production Example 7. Similarly, a cationic electrodeposition coating composition was prepared. Evaluation was performed in the same manner as in Example 1 using the obtained coating composition. The obtained results are shown in Table 2.

Example 7
Example 1 except that 5 parts by weight of Rhedol MS-50 (manufactured by Kao Corporation, glycerin ester fatty acid ester) was used instead of 1 part by weight of heptanoic acid in the production of the cationic pigment dispersion paste of Production Example 7. Similarly, a cationic electrodeposition coating composition was prepared. Evaluation was performed in the same manner as in Example 1 using the obtained coating composition. The obtained results are shown in Table 2.

Example 8
In the production of the cationic pigment dispersion paste of Production Example 7, a cation was obtained in the same manner as in Example 1 except that 2 parts by weight of Armido O (Lion Corporation, alkanolamide) was used instead of 1 part by weight of heptanoic acid. An electrodeposition coating composition was prepared. Evaluation was performed in the same manner as in Example 1 using the obtained coating composition. The obtained results are shown in Table 3.

Example 9
Example 1 except that 5 parts by weight of Esomine C / 12 (manufactured by Lion Corporation, alkylamine ethylene oxide added amine) was used instead of 1 part by weight of heptanoic acid in the production of the cationic pigment dispersion paste of Production Example 7. In the same manner as above, a cationic electrodeposition coating composition was prepared. Evaluation was performed in the same manner as in Example 1 using the obtained coating composition. The obtained results are shown in Table 3.

Comparative Example 1
A cationic electrodeposition coating composition was prepared in the same manner as in Example 1 except that 1 part by weight of heptanoic acid was not added in the production of the cationic pigment dispersion paste of Production Example 7. Evaluation was performed in the same manner as in Example 1 using the obtained coating composition. The obtained results are shown in Table 3.

Production Example 8
Preparation of resin for dispersing anionic pigment Disperse 700 parts by weight of isopropyl alcohol in a 2 L reaction vessel equipped with a stirrer, a cooling pipe, a nitrogen introduction pipe, and a thermometer connected to a temperature controller, and heat to 80 ° C. in a nitrogen atmosphere. did. In a reaction vessel, 210 parts by weight of methyl methacrylate, 196 parts by weight of butyl acrylate, 140 parts by weight of styrene, 84 parts by weight of 2-hydroxyethyl methacrylate, 70 parts by weight of acrylic acid, and 7 parts by weight of azobisdimethylvaleronitryl The solution was added dropwise at a constant rate over 3 hours, and then kept at 80 ° C. for 2 hours, whereby an acrylic copolymer for pigment dispersion having a solid content of 50%, an acid value of 78 mgKOH / g, a hydroxyl value of 52 mgKOH / g, and a weight average molecular weight of 28000 was obtained. A polymer resin (an anionic pigment dispersing resin) was obtained.

Production Example 9
Preparation of anionic pigment dispersion paste Anionic pigment dispersion resin of Production Example 8 (solid content 50%, molecular weight 28000, acid value 78, hydroxyl value 52) 100 parts titanium oxide (Taipeku CR-95, Ishihara Sangyo Co., Ltd.) 120 parts) and 5 parts of triethylamine and 115 parts of deionized water were added to obtain an anionic pigment dispersion paste having a solid content of 50%.

Production Example 10
Preparation of acrylic copolymer resin A 2 L reaction vessel equipped with a stirrer, a cooling tube, a nitrogen introduction tube, and a thermometer connected to a temperature controller was charged with 700 parts of isopropyl alcohol and heated to 80 ° C. in a nitrogen atmosphere. 322 parts of methyl methacrylate (MMA), 140 parts of butyl acrylate (nBA), 105 parts of styrene (St), 84 parts of 2-hydroxyethyl methacrylate (HEMA), 49 parts of acrylic acid (AA), azobisdimethylvaleronitrile An acrylic copolymer resin having an acid value of 55 mgKOH / g, a hydroxyl value of 52 mgKOH / g, and a weight average molecular weight of 30000 is obtained by dropping 7 parts of the mixed solution at a constant rate in 3 hours and then holding at 80 ° C. for 2 hours. It was.

Example 10
While mixing and stirring 313 parts of the acrylic copolymer resin of Production Example 10, 86 parts of Cymel 285-100 (manufactured by Cytec Co., Ltd.) which is a melamine resin as a curing agent, and 11 parts of triethylamine, the anionic pigment dispersion paste of Production Example 9 In contrast, 255 parts of heptanoic acid in an amount of 2% by weight with respect to the contained pigment was added, mixed and stirred, and 3035 parts of ion-exchanged water was further added to prepare an anionic electrodeposition coating composition. did. The resulting coating composition was subjected to a sedimentation test in the same manner as described above, and the amount of sediment (mm) after standing for 7 days was measured. Table 4 shows the obtained results.

  The obtained anion electrodeposition coating composition was coated on a silver base material obtained by subjecting a 6063S aluminum alloy plate to an alumite treatment (alumite film thickness 9 μm) and sealing treatment (immersion in hot water at 85 ° C. for 3 minutes). A DC voltage of 150 to 250 V was applied for 3 minutes, and electrodeposition was applied to achieve a predetermined film thickness. Thereafter, baking was performed at 180 ° C. for 30 minutes and drying was performed to obtain a cured electrodeposition coating film. The film thickness of the obtained cured coating film was measured. Further, the appearance of the cured coating film was visually evaluated. The case where no abnormality was observed was evaluated as “no abnormality”, and the case where abnormality could be visually confirmed was evaluated as “abnormal”. Further, as a gloss value of the cured coating film, a 60 ° specular reflectance was measured using a gloss meter (manufactured by BYK-Gardner GmbH). Table 4 shows the obtained results.

Example 11
An anionic electrodeposition coating composition was prepared in the same manner as in Example 10 except that caprylic acid in an amount of 2% by weight with respect to the contained pigment was added to the anionic pigment dispersion paste of Production Example 9. And evaluated. Table 4 shows the obtained results.

Example 12
To the anionic pigment dispersion paste of Production Example 9, except that Kadenax GS-90 (produced by Lion Corporation, alcohol ester fatty acid ester) was added in an amount of 1.8% by weight with respect to the contained pigment. In the same manner as in Example 10, an anionic electrodeposition coating composition was prepared and evaluated. Table 4 shows the obtained results.

Example 13
Except for adding an amount of 5% by weight of Cadenax GS-90 (produced by Lion Corporation, alcohol ester fatty acid ester) to the anionic pigment dispersion paste of Production Example 9 In the same manner as in No. 10, an anionic electrodeposition coating composition was prepared and evaluated. Table 4 shows the obtained results.

Example 14
Except that Kao wax EB-G (Kao Co., Ltd., unsaturated fatty acid monoamide) was added to the anionic pigment dispersion paste of Production Example 9 in an amount of 2% by weight based on the contained pigment. In the same manner as in No. 10, an anionic electrodeposition coating composition was prepared and evaluated. Table 4 shows the obtained results.

Example 15
Except that Rheidol MS-50 (produced by Kao Corporation, glycerin ester fatty acid ester) was added to the anionic pigment dispersion paste of Production Example 9 in an amount of 5% by weight based on the contained pigment. In the same manner as in No. 10, an anionic electrodeposition coating composition was prepared and evaluated. The results obtained are shown in Table 5.

Example 16
The same procedure as in Example 10 was performed, except that Armide O (an alkanolamide manufactured by Lion Corporation) in an amount of 2% by weight with respect to the contained pigment was added to the anionic pigment dispersion paste of Production Example 9. Anionic electrodeposition coating compositions were prepared and evaluated. The results obtained are shown in Table 5.

Example 17
Except for adding an amount of 2% by weight of Esomine C / 12 (produced by Lion Corporation, alkylamine ethylene oxide added amine) to the anionic pigment dispersion paste of Production Example 9 In the same manner as in Example 10, an anionic electrodeposition coating composition was prepared and evaluated. The results obtained are shown in Table 5.

Comparative Example 2
An anionic electrodeposition coating composition was prepared and evaluated in the same manner as in Example 10 except that fatty acids and the like were not added to the anionic pigment dispersion paste of Production Example 9. The results obtained are shown in Table 5.

  As can be seen from the examples and comparative examples, it is confirmed that the electrodeposition coating composition of the present invention is an electrodeposition coating composition excellent in sedimentation stability in each stage as compared with the electrodeposition coating composition of the comparative example. It was done.

It is a figure which shows typically the relationship between the electrodeposition bath used by this invention, and a circulation stirring system. In the electrodeposition bath of this invention, it is a figure which shows typically the aspect which uses a stirring apparatus, without using a circulation stirring system. It is a schematic diagram which shows the relationship between an electrodeposition bath and the 1st water-washing bath and 2nd water-washing bath which have a circulation stirring system. It is a schematic diagram which shows the relationship between an electrodeposition bath and the 1st water-washing bath and the 2nd water-washing bath which provided the stirring blade.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Electrodeposition bath 2 ... Overflow tank 3 ... Pump 4 ... Filter 5 ... Riser 6 ... Nozzle 11 ... Stirring blade 30 ... Electrodeposition bath 31 ... First washing bath 32 ... Second washing bath 33 ... Ultrafilter (UF)
34 and 35: Circulating stirring system 36: Stirring blades.

Claims (6)

(A) a fatty acid having 4 to 22 carbon atoms, a derivative of a fatty acid having 4 to 22 carbon atoms, or a pigment antisettling agent which is a mixture of the two, and (b) a pigment paste containing a pigment, and
(C) Any of the following components (c1) to (c3):
(C1) cationic resin, block polyisocyanate curing agent and curing catalyst,
(C2) anionic resin, block polyisocyanate curing agent and curing catalyst, or
(C3) anionic resin and melamine resin,
An electrodeposition coating composition containing
The curing catalyst is added at the time of preparing the pigment paste or added in another paint manufacturing process,
When the obtained electrodeposition coating composition is put in a test tube having a diameter of 20 mm to a height of 100 mm and the thickness (mm) of the precipitate generated after standing for 7 days is defined as the amount of sedimentation, the sedimentation amount is less than 5 mm. Electrodeposition paint composition.   The electrodeposition coating composition according to claim 1, wherein the fatty acid derivative is a fatty acid ester, a fatty acid amide compound, or an ethylene oxide ring-opening adduct of a fatty acid ester or a fatty acid amide compound.   The electrodeposition coating composition according to claim 1, wherein the pigment settling inhibitor (a) is contained in an amount of 0.1 to 20 parts by weight with respect to 100 parts by weight of the pigment. (A) Fatty acids having 4 to 22 carbon atoms, derivatives of fatty acids having 4 to 22 carbon atoms, or these two types A pigment antisettling agent which is a mixture of: (b) a pigment paste containing a pigment; and
(C) Any of the following components (c1) to (c3):
(C1) cationic resin, block polyisocyanate curing agent and curing catalyst,
(C2) anionic resin, block polyisocyanate curing agent and curing catalyst, or
(C3) anionic resin and melamine resin,
A method for producing an electrodeposition coating composition according to claim 1, comprising
A preparation step of preparing a pigment paste comprising the component (a) and the component (b), and
  A dispersion step of dispersing the obtained pigment paste and component (c) in an aqueous medium;
  However, the curing catalyst must be added at the time of pigment paste preparation or added during other paint manufacturing processes. When,
And the obtained electrodeposition coating composition is placed in a test tube having a diameter of 20 mm up to a height of 100 mm. When the amount of sediment (mm) generated after standing for 7 days is defined as the sedimentation amount, the sedimentation amount is 5 mm. The method for producing an electrodeposition coating composition according to claim 1, wherein (A) C4-C22 fatty acid, C4-C22 fatty acid derivative, or pigment anti-settling agent which is a mixture of these two types, (b) Preparation step for preparing pigment paste containing pigment and curing catalyst A dispersion step of dispersing the cationic resin, the blocked polyisocyanate curing agent, and the pigment paste in an aqueous medium,
A method for producing a cationic electrodeposition coating composition, comprising: depositing the resulting electrodeposition coating composition into a test tube having a diameter of 20 mm up to a height of 100 mm and allowing the precipitate formed after standing for 7 days to A method for producing a cationic electrodeposition coating composition, wherein the amount of sedimentation is less than 5 mm when the thickness (mm) is the amount of sedimentation. A preparation step of preparing a pigment paste containing (a) a fatty acid having 4 to 22 carbon atoms, a derivative of a fatty acid having 4 to 22 carbon atoms, or a mixture of these two, and (b) a pigment, and An anionic resin, a melamine resin , and the pigment paste are dispersed in an aqueous medium, a dispersion step;
The obtained electrodeposition coating composition is placed in a test tube having a diameter of 20 mm up to a height of 100 mm and the precipitate formed after standing for 7 days is included. A method for producing an anionic electrodeposition coating composition, wherein the amount of sedimentation is less than 5 mm when the thickness (mm) is the amount of sedimentation.

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