JPH07331163A - Water-base coating composition and aluminum material coated therewith - Google Patents

Abstract

PURPOSE:To obtain a coating compsn. which is excellent in electrodeposition properties and can form a coating film excellent in corrosion resistance on an Al material by using a specific acrylic-modified epoxy resin, a lubricant powder, silica particles, a silane coupling agent, and water as the main components. CONSTITUTION:A water-dilutable acrylic-modified epoxy resin is produced by grafting a polymerizable unsatd. monomer component contg. a carboxylated polymerizable unsatd. monomer (e.g. acrylic acid) onto a bisphenol epoxy resin through a polybasic acid having a polymerizable unsatd. group or its anhydride (e.g. maleic anhydride) and neutralizing the resulting product. A water-base coating compsn. is prepd. by using the acrylic-modified epoxy resin, a lubricant powder (e.g. molybdenum disulfide), silica particles, a silane coupling agent (e.g. vinyltriethoxysilane), and water as the main components. The compsn. is applied to the surface of an aluminum material to give a coated aluminum material excellent in formability, etc.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a coating composition capable of forming a coating film excellent in corrosion resistance, electrodeposition coating property and the like on the surface of an aluminum material, and a molding processability having the coating film of the coating composition. The present invention relates to a coated aluminum material having excellent chemical conversion treatability.

[0002]

2. Description of the Related Art In recent years, lightweight aluminum materials made of aluminum or aluminum alloys have come to be used as outer panels for automobile bodies and the like, and automobile bodies made of a combination of steel and aluminum materials have come to the market. It came out. For example, an automobile body made of a combination of such a steel material and an aluminum material is manufactured by assembling steel material and aluminum material that are independently formed, degreased, and chemically treated, and then sequentially and continuously subjected to electrodeposition coating and intermediate coating. It is manufactured by painting and top-coating. However, conventional aluminum materials have poor press-molding workability, and aluminum materials are less likely to degrease the press oil and rust-preventing oil used during molding compared to steel materials. When chemical conversion treatment is applied, uneven chemical conversion treatment occurs on the surface, corrosion resistance, secondary resistance to water adhesion, etc. is reduced, and aluminum is eluted during chemical conversion treatment. There was a problem that progress was hindered. Further, since the steel material and the aluminum material are used in combination, there is a problem that electrolytic corrosion of the aluminum material occurs due to contact with different metals.

On the other hand, in order to improve the above-mentioned problems, for example, forming workability, a method of changing the metal composition in the aluminum alloy (JP-A-58-171547, JP-A-61-201748, JP-A-61-201748).
61-201749, JP-A-62-27544, etc.), a method for roughening the surface of an aluminum material (JP-A-61-276707, JP-A-1-276707).
No. 21047 etc.), etc., but none of the above has been solved regarding the corrosion resistance, water resistant secondary adhesion, and electrolytic corrosion prevention. Further, in order to prevent uneven chemical conversion treatment, for example, a method of chemically cleaning the surface of an aluminum material (JP-A 1-240675,
JP-A-1-279788, JP-A-2-57692, etc.), a method of completely degreasing by lowering the viscosity of rust preventive oil (JP-A-2-115385, etc.), etc., and using the same aluminum material and steel material There is a method (Japanese Unexamined Patent Publication No. 61-104089, etc.) in which the surface area ratio of the two is specified in order to enable chemical conversion treatment, but none of them has solved the molding workability.

Further, in the above method, the surface of the aluminum material is preliminarily subjected to a surface treatment, and the coated aluminum material coated with a paint is used for forming and assembling with a steel material (Japanese Patent Laid-Open No. 3-180218, Japanese Patent Laid-Open No. 3-182218). No. 4-9476) has been proposed, but the coating film is likely to peel off in the chemical conversion treatment in the post process, resulting in reduced corrosion resistance, poor electrocoatability in the post process, and further moldability. Etc., there is a problem that the chemical conversion treatment resistance,
The above-mentioned paints having practical properties satisfying the corrosion resistance, molding processability, electrodeposition paintability, etc. have not yet been developed. Therefore, in order to solve such a problem, the inventors of the present invention, for an aluminum material, contain an epoxy resin composed of a bisphenol skeleton composed of a bisphenol A skeleton and a bisphenol F skeleton and an epichlorohydrin skeleton and a lubricant powder. Developed an organic solvent type coating composition and applied for a patent (JP-A-4-
No. 277577). However, the coated aluminum material coated with the paint has a chemical conversion treatment resistance, which is higher than that of the conventional method described above.
Although corrosion resistance, molding processability, and electrodeposition paintability have improved,
At present, in terms of corrosion resistance, molding processability, etc., higher performance has been demanded since the time of application, and in view of environmental measures, there is a strong demand for water-based paints.

[0005]

In view of the above situation, the present invention can form a coating film having excellent chemical conversion treatment resistance, corrosion resistance, molding workability, electrodeposition coating property, etc. on the surface of an aluminum material. It is an object to provide a water-based coating composition and a coated aluminum material coated with the water-based coating composition.

[0006]

[Means for Solving the Problems] That is, in order to achieve the above object, the present invention provides an aqueous coating composition containing (i) to (v) as a main component and a coating obtained by coating the surface of an aluminum material with the coating composition. Provide aluminum material. (I) Obtained by graft-polymerizing a polymerizable unsaturated monomer component containing a carboxyl group-containing polymerizable unsaturated monomer via a polymerizable unsaturated group-containing polybasic acid or an acid anhydride thereof onto a bisphenol type epoxy resin. An acrylic-modified epoxy resin that can be diluted with water by neutralizing it with a neutralizing agent, (ii) lubricant powder, (iii) silica particles, (i)
v) a silane coupling agent, and (v) water.

The present invention will be described in detail below. The acrylic modified epoxy resin (i) used in the present invention is preferably produced, for example, as follows. That is,
By introducing a polymerizable unsaturated group into the bisphenol type epoxy resin by heating and reacting the bisphenol type epoxy resin with the polymerizable unsaturated group-containing polybasic acid or an acid anhydride thereof in the presence of a reaction catalyst. Then, the bisphenol type epoxy resin having a polymerizable unsaturated group and the polymerizable unsaturated monomer component are heated and reacted to cause graft polymerization to produce an acrylic modified epoxy resin. As the bisphenol type epoxy resin, a bisphenol A type epoxy resin, a bisphenol F type epoxy resin or a mixture thereof can be used, and the epoxy equivalent is 170 to.
Those of 3500, preferably 800-2500 are suitable.

Specific examples of these bisphenol type epoxy resins include Epicoat 80.
1, 802, 807, 815, 819, 825, 82
7, 828, 834, 1001, 1002, 1003,
1004, 1007, 1010 (trade name of Yuka Shell Epoxy Co., Ltd.); DER317, 324, 325, 330,
331J, 337, 343, 361, 661, 662
(Trade name of Dow Chemical Co.); Epicron 840, 8
50, 855, 1050, 1055 [trade name of Dainippon Ink and Chemicals, Inc.]; Araldite GY250, 26
Commercial products such as 0, 280, 255, 257, 6071, 7072 (trade name, manufactured by Ciba-Geigy) are available. Representative examples of the polymerizable unsaturated group-containing polybasic acid or acid anhydride thereof include maleic acid, fumaric acid, itaconic acid, citraconic acid, and acid anhydrides thereof.

Examples of the polymerizable unsaturated monomer component include carboxyl group-containing polymerizable unsaturated monomers such as (meth) acrylic acid, maleic acid, fumaric acid, itaconic acid and maleic anhydride as essential constituent monomers. Further, a hydroxy group-containing monomer such as hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, and hydroxybutyl (meth) acrylate; an acetoacetyl group-containing monomer such as acetoacetoxyethyl (meth) acrylate; ) Methyl acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, cyclohexyl (meth) acrylate, etc. (Meth) acrylic acid ester monomer; styrene, vinyl Substituted styrene monomers such as rutoluene and methylstyrene; (meth) acrylonitrile / vinyl chloride, vinyl acetate, vinyl propionate, dialkyl maleate, etc. are available, and these monomers are used alone or in combination of two or more kinds. . Examples of the reaction catalyst include tertiary amines such as triethylamine, quaternary ammonium salt compounds such as tetramethylammonium chloride, lithium compounds such as lithium chloride and lithium bromide, imidazole compounds such as butylimidazole, sodium acetate, sodium pheno Rate, 1,8-diazabicyclo (5.4.0) -7.undecene, sodium hydroxide, potassium hydroxide and the like.

The reaction of the bisphenol type epoxy resin with the polymerizable unsaturated group-containing polybasic acid or its acid anhydride is carried out so that the polymerizable unsaturated monomer component can be grafted onto the bisphenol type epoxy resin as described above. This is done to introduce a group. Therefore, the equivalent ratio of the epoxy group of the bisphenol type epoxy resin and the carboxyl group of the polymerizable unsaturated group-containing polybasic acid or its acid anhydride is 1: 0.05 to 0.8, preferably 1: 0.1. ~ 0.3 is suitable. Incidentally, when the polybasic acid or its acid anhydride is less than the above range, the number of grafting active points for grafting the polymerizable unsaturated monomer component decreases, and the effect of modification with an acrylic resin, that is, the solvent of the acrylic modified epoxy resin Therefore, the solubility or dispersion stability in water tends to decrease, and the flexibility of the obtained coating film tends to decrease. On the other hand, if the amount exceeds the above range, gelation tends to occur easily during the graft polymerization reaction. A polymerizable unsaturated group is introduced by the reaction of a bisphenol type epoxy resin with a polymerizable unsaturated group-containing polybasic acid or an acid anhydride thereof, and the polymerizable unsaturated group is grafted with a polymerizable unsaturated monomer component. The acrylic modified epoxy resin is produced by using a carboxyl group-containing polymerizable unsaturated monomer as an essential component as the polymerizable unsaturated monomer component used at that time.

The carboxyl group-containing polymerizable unsaturated monomer imparts a carboxyl group to the resin so that it can be dissolved or stably dispersed in water as a solvent by neutralizing the resulting acrylic modified epoxy resin with a neutralizing agent. To use. The carboxyl group also contributes to the improvement of the adhesiveness of the coating film obtained. Therefore, the amount of the carboxyl group-containing polymerizable unsaturated monomer used is such that the resulting acrylic-modified epoxy resin has an acid value of about 20 or more, preferably 40 to 200.
An appropriate amount is Further, in order to improve the adhesion of the coating film and the storage stability of the coating composition, a hydroxyl group-containing monomer in an amount such that the hydroxyl value of the acrylic modified epoxy resin is about 10 to 50 is used in combination with the polymerizable unsaturated monomer component. It is desirable to do. Further, in order to improve the adhesiveness, corrosion resistance, boiling water resistance, alkali resistance, etc. of the obtained coating film, it is desirable to include 1 to 20% by weight of the polymerizable unsaturated monomer component of the acetoacetyl group-containing polymerizable unsaturated monomer. .

The acrylic modified epoxy resin used in the present invention has a weight average molecular weight of about 2,000 to 100,000.
A value of 0, preferably 4,000 to 70,000 is suitable. The weight ratio of the bisphenol type epoxy resin to the polymerizable unsaturated monomer which is graft-polymerized is preferably 4: 6 to 9: 1. When the amount of the polymerizable unsaturated monomer is less than the above range, the flexibility of the coating film obtained and the corrosion resistance of the molded portion tend to decrease, while when it is more than the above range, the bisphenol type epoxy resin is relatively high. It tends to decrease, and the adhesion and corrosion resistance of the resulting coating film tend to decrease.

The acryl-modified epoxy resin used in the present invention is neutralized with a neutralizing agent and used in a water-dilutable state so that it can be dissolved or stably dispersed in water.
Typical examples of the neutralizing agent include ammonia, methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, triethylamine, dimethylethanolamine, monoethanolamine, diethanolamine, triethanolamine and morpholine. The lubricant powder (i
It is desirable for i) to maintain the powder shape not only at room temperature but also after the coating film is formed. The lubricant powder is compounded to roughen the surface of the obtained coating film and to provide lubricity, thereby lowering the dynamic friction coefficient and improving the formability of the coated aluminum material, especially the press formability. . Representative examples of such lubricant powder include synthetic wax powder and solid lubricant powder. Examples of synthetic wax powders are synthetic hydrocarbons; fatty acid esters; fatty acid nitrogen derivatives such as fatty acid amides and substituted amides; modified waxes such as montan wax derivatives and montan oxide waxes; polymer compounds such as polyester waxes; chlorinated paraffins. Synthetic wax powder having a high saponification value and a high melting point is particularly desirable.

Examples of solid lubricant powders include layered solid lubricants such as graphite, molybdenum disulfide, tungsten disulfide, boron nitride and graphite fluoride; polyvinyl chloride, polystyrene, polymethyl (meth) acrylate, polyamide, Plastic lubricants such as high-density polyethylene, polypropylene, and polytetrafluoroethylene; metal soaps such as fatty acid calcium, barium, lithium, zinc, or aluminum are preferable, and plastic lubricants and metal soaps having particularly high surface lubricity are preferable. The particle size of the lubricant powder used in the present invention is about the average particle size.
A suitable range is 0.1 to 20 μm, preferably 0.5 to 12 μm. If the average particle size is less than 0.1 μm, the lubricant particles are less likely to be exposed on the coating film and the lubricity becomes insufficient, resulting in poor moldability. Conversely, if it exceeds 20 μm, the coating film The film-forming property and the coating stability of the product are deteriorated. The lubricant powder is
Water-soluble or water-dispersible acrylic modified epoxy resin (i) 1
1 to 50 parts by weight, preferably 3 to 100 parts by weight
Add 40 parts by weight. By adjusting the blending amount, the lubricity of the coating film is exhibited, and the physical and chemical strength of the coating film becomes appropriate. Silica particles used in the present invention (iii)
When present in the coating film, it roughens the coating film and, at the same time, the silanol groups present on the surface of the silica particles combine with the aluminum material, and contributes to the improvement of the corrosion resistance and molding processability of the coated aluminum material. Typical examples of the silica particles include water-dispersed uniform colloidal silica, water-dispersed aggregated colloidal silica, and water-dispersible powdered fumed silica.

Examples of commercially available water-dispersed uniform colloidal silica include Adelite AT-20N (trade name of Asahi Denka Kogyo KK), Snowtex ST-Nup, Snowtex-up, Snowtex 20, Snowtex 3
0, Snowtex 40, Snowtex C, Snowtex N, Snowtex O, Snowtex S, Snowtex OL [above Nissan Chemical Industries, Ltd. product name]
Etc. Examples of commercially available water-dispersed aggregated colloidal silica include PT-3025 (trade name, manufactured by Nissan Chemical Industries, Ltd.). Examples of commercially available water-dispersible powdered fumed silica include Aerosil 130, Aerosil 200, and Aerosil 30.
0, Aerosil 380, Aerosil RX200, Aerosil R202, Aerosil T805, Aerosil R80
5, Aerosil OX50, Aerosil MOX80, Aerosil MOX170, Aerosil COK84 (all manufactured by Nippon Aerosil Co., Ltd., trade name) and the like. The silica particles used in the present invention have a particle diameter of 0.01 to 2 μm, particularly 0.1 to 1.5 μm in a water-dispersed state in order to enhance the effect of roughening the coating film. Most preferred. When the particle size of the silica particles is smaller than 0.01 μm, the surface roughness of the coating film becomes insufficient, and thus the moldability becomes poor. Also,
If the particle size exceeds 2 μm, the film-forming property (adhesion) of the coating film and the stability of the coating composition tend to decrease.

The silica particles are used in an amount of about 5 to 100 parts by weight (in terms of solid content), preferably 8 to 80 parts by weight, based on 100 parts by weight of the water-soluble or water-dispersible acrylic modified epoxy resin (i).
It is suitable to blend in parts by weight. When the content of silica particles is smaller than the above range, roughening of the coating film becomes insufficient, and conversely, when it is large, the film-forming property of the coating film and the stability of the coating composition tend to decrease. The use of the silane coupling agent (iv) in the present invention has the property of aligning with respect to the surface of the aluminum material when this component is applied, so that a uniform barrier layer is formed on the surface of the aluminum material. ,
This is because it greatly contributes to the improvement of corrosion resistance. Further, it is recognized that the silane coupling agent reacts with the acrylic modified epoxy resin (i) and the silica particles (iii) during baking, and as a result, it greatly contributes to the improvement of the adhesiveness of the coating film and the fixation of the silica particles. Examples of the silane coupling agent used in the present invention include r-chloropyrtrimethoxysilane,
Vinyltrichlorosilane, vinyltriethoxysilane,
Vinyltrimethoxysilane, vinyltris (β-methoxyethoxy) silane, r-methacryloxypropyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, r-glycidoxypropyltrimethoxysilane, r-mercaptopropyltrimethoxysilane, r-aminopropyltriethoxysilane, N-β- (aminoethyl) aminopropyltrimethoxysilane, r-ureidopropyltriethoxysilane, r-glycidoxypropylmethyldiethoxysilane, There are r-glycidoxypropyldimethyl, r-glycidoxypropyldimethylethoxysilane and the like.

The silane coupling agent is about 0.01 to 100 parts by weight of the acrylic modified epoxy resin (i).
It is suitable to add 10 parts by weight (in terms of fixed amount), preferably 0.05 to 8 parts by weight. Note that the effect cannot be obtained when the content of the silane coupling agent is less than the above range,
On the contrary, if the amount is large, the stability of the coating composition tends to decrease.
The coating composition of the present invention comprises the acrylic modified epoxy resin (i), lubricant powder (ii) and silica particles (iii) described above.
And a silane coupling agent (iv) as an essential constituent, which are uniformly dispersed or dissolved in water to obtain a coating composition having a solid content of about 10 to 40% by weight. If necessary, various solvents and additives are added to the coating composition of the present invention. For example, water-soluble organic solvents, melamine resins, cross-linking agents such as benzoguanamine resins, organic or inorganic pigments,
It is an additive such as a dispersant, an antisettling agent, a leveling agent, or various modified resins. Next, a method for producing the coated aluminum material of the present invention will be described. In the present invention, any aluminum material used for ordinary applications of molded products can be used without particular limitation. For example, non-heat treatment type
Al-Mg type 5000 series alloy, heat treatment type Al-Cu-Mg type 2
000 series alloy, heat treatment type Al-Mg-Zn type 7000 series alloy, heat treatment type Al-Mg-Si type 6000 series alloy, non-heat treatment type Al-Mn type 3000 series alloy and 4000 series alloy, non-heat treatment type pure Typical examples include aluminum-based wrought 1000 series materials.

The aluminum material may be processed by a conventional means. For example, chromium chromate,
Chromium treatment such as reaction type chromate treatment such as phosphoric acid chromate, coating type chromate treatment, electrolytic type chromate treatment or zircon phosphate treatment, silane coupling treatment, titanium coupling treatment, zircon coupling treatment, aluminum coupling treatment, etc. It is an aluminum material that has been subjected to a surface treatment, such as a non-chromium treatment. The coated aluminum material of the present invention is coated with the above-mentioned coating composition on the surface of these aluminum materials by means of spraying, roll coating, shower coating or the like,
A coated aluminum material is produced by curing at a temperature of 0 ° C, preferably 100 to 250 ° C. A thin film with a thickness of about several μm will exhibit sufficient performance, but it does not prevent further increase in thickness. For example, for example,
It is preferable to apply this film so as to have a thickness of 0.1 to 10 μm, particularly 1 to 5 μm. Further, the coating composition of the present invention,
0.1 to 13 g / m ² dry weight on aluminum material, especially 1
It is preferable to apply at a rate of ˜7 g / m ² . The coated aluminum material thus obtained can be used in the fields of automobile bodies, home electric appliances, building materials, etc. by applying electrodeposition coating or ordinary topcoat coating.

[0019]

EFFECT OF THE INVENTION By coating the coating composition of the present invention on an aluminum material, a coated aluminum material and a coated aluminum product having excellent corrosion resistance, electrodeposition coating property, adhesiveness, and moldability can be obtained. In particular, when a coated aluminum material of the present invention is used as an aluminum material when manufacturing an automobile body using a steel material and an aluminum material in combination, excellent durability, that is, alkali degreasing resistance against alkali treatment in the degreasing step is obtained. In addition, in the subsequent chemical conversion treatment such as zinc phosphate treatment, a chemical conversion film is formed only on the steel material, and no chemical conversion film is formed on the coated aluminum material. Therefore, the coated aluminum material of the present invention eliminates the disadvantages of chemical conversion treatment unevenness that occurs in conventional aluminum materials, has good chemical conversion treatment resistance, and furthermore electrolytic corrosion of the aluminum material due to the contact of different metals between the steel material and the coated aluminum material. It is a coated aluminum material with high practical value, which has various effects such as prevention.

[0020]

EXAMPLES The present invention will now be described in more detail with reference to examples. In the examples, "part" and "%" are shown by weight. [Preparation of polymerizable unsaturated group-containing epoxy resin solution (A)]
A reaction device equipped with a stirrer, a reflux condenser, a nitrogen gas introduction device, and a thermometer was charged with 696 parts of bisphenol A type epoxy resin [Epicoat 1007 (trade name of Yuka Shell Epoxy Co., epoxy equivalent 1750 to 2200) and butyl cellosolve]. After 350 parts were charged and dissolved by heating, 2 parts of fumaric acid and 0.1 part of triethylamine were added with stirring while introducing nitrogen gas, and the mixture was reacted at 130 ° C. for 5 hours to give a polymerizable unsaturated polymer having a solid content of 67%. A group-containing epoxy resin solution (A) was obtained. The epoxy group of the epoxy resin and the carboxyl group of the polybasic acid were reacted at an equivalent ratio of 1: 0.1. [Preparation of polymerizable unsaturated group-containing epoxy resin solution (B)]
The resin solution (A) except that the fumaric acid was changed to 4 parts
A polymerizable unsaturated group-containing epoxy resin solution (B) having a solid content of 67% was obtained in the same manner as in the above preparation method. The reaction was carried out with the epoxy group of the epoxy resin and the carboxyl group of the polybasic acid having an equivalent ratio of 1: 0.2.

[Preparation of Polymerizable Unsaturated Group-Containing Epoxy Resin Solution (C)] Polymerization with a solid content of 67% was carried out in the same manner as in the preparation of the resin solution (A) except that the fumaric acid was changed to 6 parts. An unsaturated group-containing epoxy resin solution (C) was obtained. The epoxy group of the epoxy resin and the carboxyl group of the polybasic acid were reacted at an equivalent ratio of 1: 0.3. [Preparation of Acrylic Modified Epoxy Resin Aqueous Solution (1)] 105 parts of the polymerizable unsaturated group-containing epoxy resin solution (B) was charged in the reactor and heated to 90 ° C., and 16.2 parts of styrene and butyl acrylate were added thereto. 8 parts, acrylic acid 5.
A mixture of 8 parts, 2.4 parts of azoisobutyronitrile and 20 parts of ethylene glycol monobutyl ether was added dropwise over 2 hours with stirring, and the mixture was further reacted at the same temperature for 4 hours. After cooling to 50 ° C, dimethylethanolamine
A mixture of 5.7 parts and 170 parts of ion-exchanged water was added dropwise over 30 minutes with stirring to give an acrylic-modified epoxy resin (acid value 45, molecular weight 42,000, epoxy resin / acrylic monomer = 7) with a solid content of 30%. / 3) An aqueous solution (1) was obtained.

[Acrylic modified epoxy resin aqueous solution (2)
Preparation] The polymerizable unsaturated monomer component was added to styrene 12.8
Part, butyl acrylate 6.4 parts, acrylic acid 5.8 parts, and acetoacetoxymethacrylate 5 parts, except that the acrylic modified epoxy resin aqueous solution (1) is prepared in the same manner as described above, and the solid content is 30%. A modified epoxy resin (acid value 45, molecular weight 52,000, epoxy resin / acrylic monomer = 7/3) aqueous solution (2) was obtained. [Preparation of Acrylic Modified Epoxy Resin Aqueous Solution (3)] Polymerizable unsaturated monomer component was added to styrene 8.8 parts, butyl acrylate 6.4 parts, acrylic acid 5.8 parts, 2-hydroxyethyl methacrylate 4 parts, acetoacetoxy. Acrylic modified epoxy resin (acid value: 45, molecular weight: 500,00, solid content: 30%) was prepared in the same manner as in the preparation of the acrylic modified epoxy resin aqueous solution (1) except that the amount of the methacrylate was changed to 5 parts.
0, epoxy resin / acrylic monomer = 7/3) to obtain an aqueous solution (3). [Preparation of Acrylic Modified Epoxy Resin Aqueous Solution (4)] A polymerizable unsaturated monomer component was added to 8.8 parts of styrene, 6.4 parts of butyl acrylate, 5.8 parts of acrylic acid, 4.0 parts of 2-hydroxyethyl methacrylate, Acrylic modified epoxy resin (acid value 45, molecular weight 45,000, epoxy resin / acrylic monomer) with a solid content of 30% was prepared in the same manner as in the preparation method of the acrylic modified epoxy resin aqueous solution (1) except that methyl methacrylate was changed to 5 parts. = 7/3) Water-based liquid (4)
Got

[Acrylic modified epoxy resin aqueous solution (5)
Preparation] The polymerizable unsaturated group-containing epoxy resin solution (A)
And change the polymerizable unsaturated monomer component to styrene 12.8
Parts, butyl acrylate 6.4 parts, acrylic acid 5.8 parts, acetoacetoxy methacrylate 5 parts, except
Acrylic modified epoxy resin aqueous solution (5) having a solid content of 30% was prepared in the same manner as in the preparation method of acrylic modified epoxy resin aqueous solution (1) (acid value 45, molecular weight 40,000, epoxy resin / acrylic monomer = 7/3). Obtained. [Preparation of Acrylic Modified Epoxy Resin Aqueous Solution (6)] The polymerizable unsaturated group-containing epoxy resin solution was changed to 75 parts (C), and the polymerizable unsaturated monomer component was styrene 25 parts, butyl acrylate 10.2 parts, and acrylic. Acrylic-modified epoxy resin with a solid content of 30%, in the same manner as in the preparation of the acrylic-modified epoxy resin aqueous solution (1) except that the acid was changed to 5.8 parts, 2-hydroxyethyl methacrylate 4 parts, and acetoacetoxy methacrylate 5 parts. (Acid value 45, molecular weight 45,000, epoxy resin / acrylic monomer = 5 /
5) An aqueous solution (6) was obtained.

Examples 1 to 6 and Comparative Examples 1 to 4 Mixtures of acrylic modified epoxy resin aqueous solution, lubricant powder, silica particles and silane coupling agent shown in Tables 1 and 2 were diluted with deionized water. A paint having a solid content of 20% was prepared. The paints obtained were applied to various types of aluminum materials (thickness 1.0 mm) which had been subjected to various types of undercoating as shown in Tables 1 and 2, and the dry film thickness was 3 μm
Roll coating, and baking to reach a maximum plate temperature of 150 ° C in 30 seconds, corrosion resistance, moldability, alkali resistance, chemical conversion treatment resistance, electrodeposition paintability, topcoat adhesion,
Each test of water resistance, slip resistance, and paint stability was carried out, and the results are shown in Table 3. As is clear from Table 3, Examples 1 to 6 which are coating compositions of the present invention had excellent coating film performance. On the other hand, Comparative Example 1 containing no lubricant powder
Has poor moldability, Comparative Example 2 containing no silica particles has poor corrosion resistance, Comparative Example 3 containing no silane coupling agent has poor water resistance, and silica particles, silane Comparative Example 4 containing no coupling agent had poor corrosion resistance and the like.

[0025]

[Table 1] Table 1 Practical example 1 2 3 4 5 6 Aluminium 5000 series 6000 series 2000 series 5000 series 2000 series 6000 series Go alloy alloy gold (applied gold (black alloy gold (unprocessed gold (silver (uncoated Treated Chromememe (untreated) Nucleated) Treated) Tromate treated) Ring agent treated) Treated) Treated) Acrylic modified (1) (2) (3) (4) (5) (6) Epoxy resin Aqueous solution Solid content (parts) 100 100 100 100 100 100 Lubricant powder Fatty acid Polyethytetra stearyl molybdenum diester Fatty acid ester Lenwaffle fluoric acid Carlybdenster Stell coated Xroethium lenwax Note 1) Note 2) Note 3) Note 4) Note 5) Note 1) Compounding amount (part) 15 3 8 40 25 32 Synthetic silica particles Water dispersion Water dispersion Hue water dispersion Condensation Left water dispersion Uniform colloid Agglomerate colloid Collective colloid Uniform colloid Idarsi Iridica Silica Durcili Idar Silica Rica Carica Note 6) Note 7) Note 8) Note 7) Note 6) Solid content (part) 80 10 20 50 8 30 Silane cap Epoxy Same as left Amine Same as left Mercap Same as left Pulling agent Silane-based silatan-based syccyllic ring-curing Ranking Agent Purpuring agent Compounding amount (part) 8 2 5 0.05 0.08 2

[0026]

[Table 2]Table 2  Comparative example 1 2 3 4 Aluminum alloy material 5000 series alloy Same as left Same as left 2000 series alloy (Undercoating) (Coating type (untreated) Lomate treatmentReason) Acrylic modified epoxy (1) (1) (2) (3) Resin solutionSolids content (part) 100 100 100 100 Lubricant powder Fatty acid S Same as on the left Tetrafluorether ethylene oxide Note 1) X Note 3) Compounding amount (part) 0 40 15 15 Silica particles Water dispersion uniform Water dispersion uniform Colloidal Colloidal silica Silica Note 6) Note 6)Solid content (part) 90 0 80 0 Silane cup Epoxy-based Same as left Silane coupling agentCompounding amount (part) 8 100 0

[0027]

[Table 3] Table 3 Example Comparative Example 1 2 3 4 5 6 1 2 3 4 4 Corrosion resistance Note 9) ◎ ◎ ◎ ○ ○ ○ ○ △ × △ × Coating processability Note 10) ◎ ◎ ◎ ◎ ◎ ◎ ◎ × △ ○ △ Alkali resistance Note 11 ) ◎ ◎ ◎ ◎ ◎ ◎ ◎ △ △ × △ Film resistance to chemical conversion treatment Note 12) ◎ ◎ ◎ ◎ ◎ ◎ ◎ △ △ × △ Electrodeposition coatability Note 13) ◎ ◎ ◎ ◎ ◎ ◎ ◎ ○ × ○ × Adhesive topcoat adhesion Note 14) ◎ ◎ ◎ ◎ ◎ ◎ ◎ ○ × △ × Water resistance Note 15) ◎ ◎ ◎ ○ ○ ○ △ × × × Sliding Note 16) ◎ ◎ ◎ ◎ ◎ ◎ × △ ○ △ Paint stability Note 17) ◎ ◎ ◎ ◎ ◎ ◎ ◎ △ ○ ○ ○

Note 1) Average particle size 10 μm Note 2) Average particle size 1 μm Note 3) Average particle size 5 μm Note 4) Average particle size 3 μm Note 5) Average particle size 1 μm Note 6) Average particle size 0.01 μm Note 7) Average particle size 0.5 μm Note 8) Average particle size 0.2 μm Note 9) After spraying 5% saline solution at 35 ° C for 4 hours,
A cycle corrosion test was conducted with a step of drying at 0 ° C. for 2 hours and standing at 50 ° C. and 95% RH (wet) for 2 hours as one cycle, and the white rust generation state after 100 cycles was evaluated. ◎ ・ ・ ・ ・ White rust did not occur (area ratio) ○ ・ ・ ・ ・ White rust less than 5% (area ratio) △ ・ ・ ・ ・ White rust less than 15% (area ratio) × ・ ・ ・ ・ White rust 15 % Over (area ratio)

Note 10) Five test plates with 90 mmφ punching
Cylindrical drawing with 0 mmφ and 25 mm depth (BHF = 1 ton)
After processing, spray 5% saline at 35 ° C. for 4 hours, then
A cycle corrosion test was conducted with a cycle of drying at 0 ° C. for 2 hours and standing at 50 ° C. and 95% RH (wet) for 2 hours as one cycle, and the white rust generation state after 50 cycles was evaluated. ◎: No white rust ○: White rust less than 5% (area ratio) △: White rust less than 15% (area ratio) ×: White rust more than 15% (area ratio) Note 11) Test plate with alkaline degreasing liquid at 45 ° C Immerse in "Granda Cleaner 26F" (product name of Million Chemical Co., Ltd.) for 5 minutes, wash with water, dry, cut 100 1 mm squares with a cutter knife, perform a peeling test using cellophane tape, and check the residual rate of the coating film. It was measured. ◎: No peeling ○: Peeling within 5% △: Peeling 5 to 35% ×: Peeling over 35% Note 12) The test plate was immersed in a zinc phosphate treatment solution at 45 ° C for 5 minutes, washed with water and dried to observe the coating film did. ◎: No coating peeling, uniform coating as before chemical conversion treatment ○: Little coating peeling (less than 5%) △: Coating peeling (5% or more) ×: Full peeling of coating

Note 13) The surface of the test plate was coated with an amine-added epoxy resin-blocked isocyanate type cationic electrodeposition coating under the conditions of a bath temperature of 28 ° C. and 100 V × 3 minutes, and then baked at 165 ° C. for 20 minutes. , Coating film (area 1
00 cm ² ) The appearance was observed. ◎: Gas pin and crater generation 0 points ○: 〃 1 to 5 points △: 〃 6 to 20 points ×: 〃 20 points or more Note 14) 1 mm of the cationic electrodeposition coated plate obtained in Note 13)
100 pieces of cross stitch were cut with a cutter knife, a peeling test was performed using cellophane tape, and the residual rate of the electrodeposition coating film was measured. ◎: 100% ○: 95-99% △: 90-94% ×: 89% or less Note 15) The cationic electrodeposition coated plate obtained in Note 13) 40
After being immersed in water at ℃ and dried, a peeling test was performed in the same manner as in Note 14) to measure the residual rate of the electrodeposition coating film. ◎: Remaining rate after immersion for 600 hours 100% ○: 〃 500 〃 100% △: 〃 500 〃 90-99% ×: 〃 500 〃 89% or less

Note 16) Using a surface measuring device HEIDON-14 (manufactured by Shinto Kagaku Co., Ltd.), load 50 g, ball indenter ¢ 10 m
The measurement was performed under the conditions of m and a moving speed of 50 mm / min. ◎: Dynamic friction coefficient less than 0.10 ○: 〃 0.10 to less than 0.20 △: 〃 0.20 to less than 0.35 ×: 〃 0.35 or more Note 17) 50 paints of each Example and Comparative Example After standing still at room temperature for 3 weeks, the paint state was observed after standing at room temperature for 1 day. ⊚: Some separation occurred, redispersion possible with stirring for 15 minutes ◯: Some separation occurred, redispersion possible with stirring for 30 minutes Δ: A considerable amount of separation occurred, redispersion possible with stirring for 30 minutes ×: Corresponding amount Is generated and cannot be redispersed by stirring for 30 minutes

 ─────────────────────────────────────────────────── --- Continuation of the front page (72) Inventor Teiichi Tonomura 1-10-7 Kusanagi, Yamato-shi, Kanagawa Prefecture (72) Inventor Hiroharu Sasaki 7 1414-46, Shimonagata, Nishinasuno-cho, Nasu-gun, Tochigi Prefecture (72) Invention Toshiharu Ohata 3-172-1 Shimonagata, Nishinasuno-cho, Nasu-gun, Tochigi Prefecture Co-op Cherry B-104

Claims (5)

[Claims] 1. (i) A bisphenol type epoxy resin is grafted with a polymerizable unsaturated monomer component containing a carboxyl group-containing polymerizable unsaturated monomer through a polymerizable unsaturated group-containing polybasic acid or an acid anhydride thereof. Acrylic-modified epoxy resin that is polymerized and becomes water-dilutable by neutralization, (ii) lubricant powder, (iii) silica particles, (iv) silane coupling agent, and (v) water as main components Water-based coating composition. 2. The polymerizable unsaturated monomer component comprises an acetoacetyl group-containing polymerizable unsaturated monomer.
The water-based coating composition as described in 1. 3. The weight ratio of the bisphenol type epoxy resin and the polymerizable unsaturated monomer component graft-polymerized to the epoxy resin in the acrylic modified epoxy resin is 4: 6 to 9: 1. 2. The water-based coating composition according to 2. 4. Acrylic modified epoxy resin (i) 100
1 to 50 parts by weight of the lubricant powder (ii), 5 to 100 parts by weight of the silica particles (iii) (silica solid content), and 0 of the silane coupling agent (iv) (fixed content) based on parts by weight. .0
The water-based coating composition according to claim 1, 2 or 3, wherein 1 to 10 parts by weight is blended and the solid content is 10 to 40% by weight. 5. The aluminum material surface according to claim 1, 2,
A coated aluminum material coated with the coating composition according to any one of 3 and 4.