JP3525234B2 - Treated pigment - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for preventing color separation of a coating composition in which an inorganic pigment and an organic pigment are mixed.

[0002]

2. Description of the Related Art When inorganic pigments and organic pigments are used in combination as pigments in the production of colored paints, printing inks, color plastic moldings, etc., the inorganic pigments and organic pigments are used as a resin and other raw materials by using an appropriate dispersing machine. To obtain a coating composition in which the pigment is dispersed.
The coating composition thus obtained may be distributed as a final product as it is as a colored coating composition, or may be distributed as a color plastic molded product after a molding process.

By the way, a colored coating material is a main element for forming a coating film such as a resin, a sub-element for forming a coating film which is added to the main element in a small amount (both elements are collectively referred to as a coating element (nonvolatile component)), And a solvent or diluent coating auxiliary element (the coating element and the coating auxiliary element are collectively referred to as a transparent paint (color-developing agent)), and a pigment is added and kneaded. Further, the printing ink is manufactured by adding a pigment to a color developing agent in which a resin is dissolved in a solvent. Further, the color plastic molded products that are widely used from household products to building materials are manufactured by kneading a resin and a coloring pigment. Both include the step of uniformly dispersing the pigment in the resin and other raw materials during manufacture.

However, the biggest problem in producing a coating composition in which the above-mentioned inorganic pigments and organic pigments are dispersed is that the color tone of the coating composition tends to change during storage and application of the coating composition. Especially. It is considered that such a change in color tone (color division) is caused by separation of the inorganic pigment and the organic pigment in the coating composition. This color separation can occur in various steps other than the above. For example, it occurs in a pigment dispersion process or a color plastics molding process. As a result, troubles during the manufacturing process, or deterioration of the gloss, tinting strength, and image clarity of the coating film or product finally obtained,
It is known that undesired phenomena such as color separation and floating occur.

The factors that are considered to be the cause of this color separation are as follows: 1) difference in relative movement cheapness of the mixed pigments, 2) convection generated in the paint during drying, and 3) multiple pigments mixed. Aggregation of specific pigments among them is known. In order to prevent these, for example, (a) a method of adding a surfactant such as an alkyl silicone to prevent convection of the paint, (b) adsorbing a polymer having an amino group or a carboxyl group or a long-chain aliphatic compound to the pigment particles. hand,
A method is known in which a plurality of pigments are loosely co-flocculated to a desired degree to prevent color separation. However, the use of the alkyl silicone used in the method (a) is often impaired in recoatability and its use is limited, and the polymer or long-chain aliphatic compound having an amino group or a carboxyl group used in the method (b) is colored. There is a problem that the effect of prevention is small and the effect is lost by the resin.

[0006]

[Problems to be Solved by the Invention] In the production of colored paints, printing inks, color plastic moldings, etc., after mixing resins and other raw materials with inorganic pigments and organic pigments, the color separation between the inorganic pigments and organic pigments It's about providing a way that won't happen.

[0007]

As a result of intensive studies to solve the above problems, the present inventor found that the organic pigment should be treated with a basic functional group in advance in order to prevent color separation between the inorganic pigment and the organic pigment. It has been found that the problem can be solved by treating the inorganic pigment with a dispersant having an acidic functional group as well as the treatment with a dispersant having a. That is, the present invention is a treated pigment comprising an organic pigment treated with a dispersant having a basic functional group and an inorganic pigment treated with a dispersant having an acidic functional group. In the present invention, the dispersant is preferably a polymer dispersant, and particularly, a dispersant having a basic functional group is a urethane polymer dispersant, and a dispersant having an acidic functional group is a carboxylic acid or a salt thereof, a sulfone. A polymer dispersant containing an acid or a salt thereof has a remarkable effect. The present invention is also a coating composition in which the above treated pigment is mixed with a solvent and a resin. Among the resins, the effect is remarkable when blended with urethane, acrylic, polyester or alkyd resin.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Inorganic pigments used in the present invention include titanium dioxide, iron oxide, cadmium sulfide, calcium carbonate,
Examples thereof include barium carbonate, barium sulfate, clay, talc, and yellow lead, and inorganic pigments such as titanium dioxide, which has a pH of the pigment surface of 6 to 10 and which is relatively basic, calcium carbonate, barium sulfate, and the like are preferable.

On the other hand, as the organic pigment used in the present invention,
Carbon black (in the present invention, carbon black which has been conventionally regarded as an inorganic pigment is also treated as an organic pigment), azo type, diazo type, condensed azo type, thioindigo type, indanthrone type, quinacridone type, anthraquinone type, benzimidazolone Examples thereof include organic pigments such as system, perylene system, perinone system, phthalocyanine system, halogenated phthalocyanine system, anthrapyridine system and dioxazine system. Applicable to any organic pigment, but more violently colored carbon black, phthalocyanine-based,
Especially when the dioxazine type is used, a remarkable effect is obtained.

The dispersant having a basic functional group used in the present invention is generally a dispersant having an amino group. In particular, the dispersant used in the coating material field of the present invention is generally a polymer type dispersant having an average molecular weight of 300 or more, and the polymer type is also suitable in the present invention. This is because the polymer type, which is generally considered to be excellent in dispersion stability, is advantageous in producing a coating material.

Specific examples of the above-mentioned polymer type dispersant include the following. 1) A part of the isocyanate group of the polyisocyanate compound is reacted with a compound having one hydroxyl group, and an unreacted part of the polyisocyanate compound is reacted with a compound having an isocyanate group and active hydrogen at both ends. A dispersant obtained by reacting an unreacted isocyanate group with a compound having a substituent having active hydrogen and a tertiary amino group or a heterocyclic group. 2) A polyester having a hydroxyl group at the molecular end obtained by reacting a monocarboxylic acid compound with a monoepoxy compound, an acid anhydride and a lactone, or a compound having a monohydric alcohol, a monoepoxy compound and a lactone, depending on the case. Further, a polyester having a hydroxyl group at the molecular end obtained by reacting an acid anhydride is reacted with a diisocyanate compound, and further a hydroxyl group-containing copolymerizable monomer is reacted to obtain a polyester macromer, or It is obtained by reacting an acid anhydride with any of them, reacting with glycidyl (meth) acrylate to obtain a polyester macromer, and further copolymerizing a copolymerizable monomer containing a tertiary amino group with any of the above polyester macromers. Dispersant. 3) Reaction product of monocarboxylic acid compound and lactone, reaction product of monocarboxylic acid compound and acid anhydride and monoepoxy compound, reaction product of monohydric alcohol and acid anhydride and monoepoxy compound, monohydric alcohol and lactone A compound obtained by reacting an acid anhydride with the reaction product of, or
Any one of the compounds having a carboxyl group at one end obtained by polymerizing a polymerizable vinyl group-containing monomer using a radical chain transfer agent having a carboxyl group and a mercapto group is reacted with a polyepoxy compound, and then in the molecule. A dispersant obtained by reacting an organic amino compound having one secondary amino group. Regarding these three kinds of dispersants, (1) is disclosed in JP-B-2-19844, and (2) is disclosed in JP-A-4-22777.
4 and (3) are described in Japanese Patent Application No. 7-250953.

The average molecular weight of the above dispersant is 1,000.
It is preferably in the range of 100,000. When the average molecular weight is less than 1,000, the polymer component of the dispersant adsorbed on the pigment is not sufficient as a steric repulsion layer and reaggregation of dispersed particles occurs, which is not preferable. Further, even if the average molecular weight exceeds 100,000, it is difficult to produce it with good reproducibility, and if the number average molecular weight of the pigment dispersant exceeds 100,000, it acts as an aggregating agent. There are cases where it is not preferable. Further, the amine value of the above dispersant is preferably in the range of 5 to 200 mgKOH / g, and when the amine value is less than 5 mgKOH / g, the dispersant is insufficiently adsorbed onto the pigment surface, so It is not preferable because it is easily desorbed and the dispersion stability is lowered. Also, the amine value of the dispersant is 200 m.
When it exceeds gKOH / g, the ratio of the three-dimensional repulsion layer to the adsorbed component of the dispersant absorbed on the pigment surface becomes too small,
It is not preferable because sufficient pigment dispersion stability cannot be obtained, and in addition, it may cause deterioration of performance such as water resistance, weather resistance and adhesion of the coating film.

Among them, the dispersants described in the above (1) and (2) are those having a urethane bond in the molecule. Among them, the average molecular weight is 500 to 10,000,
The effect is high when a dispersant having an amine value in the range of 5 to 200 mgKOH / g is used.

The commercially available dispersant having a basic functional group is EFKA Polymer 4 manufactured by EFKA Chemical Company.
00, EFKA polymer 401, EFKA polymer 40
2, EFKA polymer 403, EFKA-46, EFK
A-47, EFKA-49, San Nopco Texahole 277, Hoechst Japan Ltd. Additol XL
203, Disperbyk 160 manufactured by Big Chemie,
161, 162, 163, 164, 165, 166, and the like, among which EFKA manufactured by EFKA Chemical Co., Ltd.
-46, EFKA-47, EFKA-49 and Big Chemie Disperbyk 160, 161, 162, 1
63, 164, 165, 166 are preferred.

The dispersant having an acidic functional group may be one having a carboxylic acid or a salt thereof, or a sulfonic acid or a salt thereof, and more preferably a polymer type having a molecular weight of 300 or more.

Specifically, naphthalenesulfonic acid formalin condensate, naphthalenesulfonic acid formalin condensate Na
Examples thereof include salts, polyester amine salts and carboxyl group-containing polyesters. Suitably, these polyesters have a molecular weight of about 350-8000, preferably 500-5.
It is preferably 000.

Among the above, the carboxyl group-containing polyester can be produced by the following method. That is, acetic acid, propionic acid, caprylic acid, nonanoic acid, capric acid, octylic acid, lauric acid, myristic acid, palmitic acid, stearic acid, isononanoic acid, aliphatic monocarboxylic acids such as arachidic acid, benzoic acid, p-tertiary acid. A compound having one -COOH group such as an aromatic monocarboxylic acid such as ributylbenzoic acid, and p-toluenesulfonic acid or dibutyltin laurate as an initiator, propiolactone, valerolactone, caprolactone or a substituted derivative thereof. Can be obtained by reacting at a temperature of about 100 to 180 ° C.

Another example of polyester is --COOH.
Also included are those obtained by the condensation of a glycol and a dibasic acid in the presence of a compound having one group.

Commercially available products of the dispersant having an acidic functional group are Dimor N, Dimor NL, Dimor RN manufactured by Kao, Labelin manufactured by Daiichi Kogyo Seiyaku Co., Dispar 40 manufactured by Miyoshi Yushi-Seiya Co., Ltd., Polity N manufactured by Lion. -10
0, Solgenes 3000 manufactured by Zeneca, Disperbyk 110 manufactured by Big Chemie, Anti-Terra 2
03, 204, Ajinomoto Co., Azisper PA111, and the like.

The dispersant having an acidic functional group and the dispersant having a basic functional group of the present invention (hereinafter, both of them will be collectively referred to as a dispersant used in the present invention) are usually 1 to the pigment.
200% by weight is used. The dispersant used in the present invention may be in the form of a synthetic reaction liquid without removing the reaction solvent used in the reaction for producing the dispersant, if there is no problem.

In order to obtain the treated pigment of the present invention, an organic pigment and an inorganic pigment are treated with the above-mentioned dispersants, respectively,
The treated pigment may be mixed. As a treatment method, a dry method using a Henschel mixer or the like, or a wet solvent method of removing the solvent after treating in a solvent can be used.
The treated pigments may be mixed with an ordinary stirring device, and examples thereof include a roll mill, a ball mill, a sand grind mill, a paint shaker, a kneader, a dissolver, and an ultrasonic disperser. Further, the resin and solvent used in the present invention may be further added when treating the pigment. In this case, the mixing method may be an integral blending method which is commonly used in the paint field.

The solvent used in the wet solvent method is not limited, but hydrocarbon solvents such as toluene, xylene, high boiling point petroleum hydrocarbons, n-hexane, cyclohexane and n-heptane, halogens such as methylene chloride, chloroform and dichloroethane. Hydrocarbon solvents, dioxane, tetrahydrofuran, butyl ether, butyl ethyl ether, diglyme and other ether solvents, methyl isobutyl ketone, cyclohexanone, isophorone and other ketone solvents, ethyl acetate, butyl acetate, ethylene glycol monoethyl ether acetate, 2 -Ester solvent such as methoxypropyl acetate, alcohol solvent such as methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropanol, butanol ethylene glycol monomethyl ether Ter, in addition to alkylene glycol monoether solvents such as propylene glycol monomethyl ether, amide solvents such as dimethylacetamide, dimethylformamide, and the like, which is appropriately selected depending on the intended use of the coating composition, These may be used alone or in admixture of two or more, as appropriate.

Further, in order to obtain the coating composition of the present invention, the treated pigment obtained above may be kneaded with a solvent and a resin. As a kneading method, an ordinary method such as an integral blending method can be used.

The resin used for producing the coating composition of the present invention is an alkyd resin, polyester resin, acrylic resin, epoxy resin, polyurethane resin, silicone resin, fluororesin, melamine resin, benzoguanamine resin, urea resin, polyamide resin. , Phenol resin, vinyl chloride, polyethylene resin and the like. More preferably, alkyd resin, polyester resin, acrylic resin, and polyurethane resin are most suitable.

As the solvent used for producing the coating composition of the present invention, the solvent used in the wet solvent method can be used. These are appropriately selected depending on the application of the coating composition, and these can be used alone or in admixture of two or more.

As a mixer used in the integral blend, a roll mill, a ball mill, a sand grind mill, a paint shaker, a kneader, a dissolver, an ultrasonic disperser, or the like can be used according to each application of the coating composition.

On the other hand, as described above, a dispersant having a basic functional group, an organic pigment, a coating composition (dispersion paste) consisting of a solvent and a resin, and a dispersant having an acidic functional group, an inorganic substance. A coating composition (dispersion paste) including a pigment, a solvent, and a resin may be produced by an integral blending method or the like, and these may be mixed to produce the coating composition of the present invention. For the mixing in this case, a roll mill, a ball mill, a sand grind mill, a paint shaker, a kneader, a dissolver, an ultrasonic disperser, or the like may be used.

The coating composition of the present invention can be put into the distribution as a product having a concentration which can be used as it is by appropriately adjusting the amount of the solvent in the production thereof, or in the form of a concentrated product. Needless to say, it can be used by diluting it with a solvent and adjusting it to an appropriate concentration by the purchaser.

[0029]

EXAMPLES The present invention will be specifically described below with reference to production examples, examples and comparative examples. In addition, "part" and "%" in each example are based on weight.

(A) Synthesis of Dispersant Production Example 1. Synthesis Example of Dispersant Having Acidic Functional Group Xylene (manufactured by Junsei Chemical Co., Ltd.) in a reaction flask equipped with a thermometer, a stirrer, a nitrogen inlet, a reflux tube and a water separator.
0 parts, 12-hydroxystearic acid (manufactured by Junsei Kagaku) 3
00.0 parts and tetrabutyl titanate (manufactured by Tokyo Kasei)
0.1 part was charged and the temperature was raised to 160 ° C. over 4 hours under a nitrogen stream. The mixture was further heated at 160 ° C for 4 hours (the acid value at this time was about 20 mgKOH / g), and xylene was distilled off at 160 ° C. Then, the mixture was cooled to room temperature, water generated during the heating reaction was separated from xylene in the distillate, and this xylene was returned to the reaction solution. This reaction liquid is hereinafter referred to as Polyester PA-1. The polyester contained in Polyester PA-1 had a number average molecular weight of 2,550 and an acid value of 22.0 mgKOH / g.

Production Example 2. Synthesis of dispersant having basic functional group 1 150.0 parts of xylene, 0.3 part of tetrabutoxy titanate, 44.0 parts of octylic acid, ε in a flask equipped with a stirrer, a reflux tube, a thermometer, and a nitrogen gas introducing tube. -Capturing 556.0 parts of caprolactone, it heated up to 140-160 degreeC. Then, the reaction is carried out at 160 ° C, and the solid content is 79%.
The reaction was terminated at the time. After cooling to room temperature,
249.7 parts of xylene was added to obtain a polyester A having a carboxyl group at one end. The resulting polyester A had a number average molecular weight of 2,100, a solid content of 60.0%, and an acid value of 29.0 mgKOH / g. 300.0 parts of xylene was charged into a flask equipped with a stirrer, a reflux pipe, a thermometer, and a nitrogen gas introduction pipe, and the temperature was raised to 130 to 135 ° C. A mixture of 390.0 parts of glycidyl methacrylate, 210.0 parts of butyl methacrylate and 36.0 parts of tert-butyl peroxy-2-ethylhexaate was added dropwise over 2 hours and then polymerized at 135 ° C. for 1 hour. Let Then, a mixed solution prepared by dissolving 3.0 parts of tertiary butyl peroxy-2-ethylhexaate in 10.0 parts of xylene was added, and a polymerization reaction was further performed at 120 ° C. for 5 hours to complete the reaction. After cooling to room temperature, xylene 5
1.0 part was added to obtain a polyepoxy compound. The obtained polyepoxy compound has a solid content of 62.0%, a number average molecular weight of 4,100, and an epoxy value of 250.0 mgKOH /
It was g.

In a flask equipped with a stirrer, a reflux tube, a thermometer, and a nitrogen gas introducing tube, 35.7 parts of xylene, 45.1 parts of the polyester A obtained above, and 15.7 parts of the polyepoxy compound obtained above were added. A portion was charged and the temperature was raised to 120 ° C. to carry out the reaction. When the acid value became 1 mgKOH / g or less, the mixture was cooled to 60 ° C., and di-n-butylamine 3.
5 parts was added and the temperature was raised to 100 ° C. 4-5 at 100 ° C
A dispersant having a basic functional group (hereinafter, referred to as P
B-1) was obtained. The resulting pigment dispersant 1 had a solid content of 40.1%, a number average molecular weight of 10500, and an amine value of 38.5 mgKOH / g.

Production Example 3. Synthesis of Dispersant Having Basic Functional Group 2 Synthesis was carried out based on the production examples described in JP-A-4-227774. Stirrer, reflux pipe, thermometer, nitrogen gas inlet pipe,
A flask equipped with a dropping tank was charged with 36.8 parts of xylene, 1.0 part of decanol, and 0.1 part of sodium methylate, and heated to 130 to 140 ° C. under nitrogen flow. In the reflux state, 35.7 parts of ε-caprolactone was dropped from the dropping tank over 1 hour. After stirring under reflux for 4 hours, it was confirmed that the solid content after heating and drying at 140 ° C. for 30 minutes reached 45%, and 15.5 parts of butyl glycidyl ether was added dropwise from the dropping tank over 1 hour. 4.5 parts of tolylene diisocyanate was added and stirred at 30 ° C. for 2 hours, it was confirmed that 50% of the isocyanate groups had reacted, and 1.5 parts of 2-hydroxyethyl methacrylate was added. This is 6
The temperature was raised to 0 ° C., the reaction was carried out for 3 hours, and the reaction was terminated when 100% of the isocyanate groups had reacted. The obtained product is designated as Macromer A.

A flask equipped with a stirrer, a reflux tube, a thermometer, and a nitrogen gas inlet tube was charged with 39.0 parts of xylene.
The temperature was raised to 0 ° C., and 1.0 parts and 2, of the above-obtained Macromer A and dimethylaminopropyl acrylamide,
2'-azobis (2,4 dimethylvaleronitrile) 0.
Eight parts of 20% solution were added dropwise from separate dropping tanks over 2 hours. After the dropping, the mixture was reacted at 85 ° C. for 2 hours to obtain a dispersant having a basic functional group (hereinafter referred to as PB-2).

Production Example 4. Synthesis of Dispersant Having Basic Functional Group 3 Synthesis was carried out based on the production examples described in JP-B-2-19844. A flask equipped with a stirrer, a thermometer, and a nitrogen gas introduction tube was charged with 2.9 parts of isononanol and 9 parts of caprolactone.
7.1 parts and 0.002 parts of dibutyltin laurate were mixed under a nitrogen gas flow and heated to 170 ° C. within 1 hour. The reaction was terminated when the solid content reached 99.5%. Polyester B having no solid and a melting point of 60 to 70 ° C. was obtained.

A flask equipped with a stirrer, a reflux tube, a thermometer, and a nitrogen gas inlet tube was charged with 6.3 parts of aromatic-aliphatic polyisocyanate (60% in butyl acetate), 15 parts of ethyl acetate cellosolve, and 36 parts of xylene. The mixture was charged and mixed, and 0.7 part of polyethylene glycol having an average molecular weight of 400, 19.6 parts of the polyester B obtained above, and 0.002 part of dibutyltin dilaurate were added. When the reaction of all OH groups was completed, 0.9 part of 4- (2-hydroxyethyl) -pyridine was added, and the solid content of the reaction mixture was adjusted to 2 with xylene.
It was set to 5%. The reaction mixture was stirred at 60 ° C. for 1 hour until the reaction was complete. The dispersant having a basic functional group (hereinafter referred to as PB-3) thus obtained was colorless and transparent and had a number average molecular weight of 14,000.

(B) Resin Synthesis Example Production Example 5. In a reaction flask equipped with a polyester synthesis thermometer, a stirrer, a nitrogen inlet, a reflux tube and a water separator, a saturated monocarboxylic acid glycidyl ether "CARDULER E-10" (trade name, manufactured by Shell Chemical Co., Ltd.) 90.0 parts, isophthalic acid 150.0 parts,
Adipic acid 155.4 parts, trimethylolpropane 4
5.2 parts and 159.5 parts of neopentyl glycol were charged, and the temperature was raised to 170 to 230 ° C. over 4 hours under a nitrogen stream. After the mixture was ripened at 230 ° C. for 2 hours for esterification, the produced water was removed and the mixture was further heated at 230 ° C. for 4 hours to continue the esterification reaction. Then, 3% of xylene was charged with respect to the total amount charged, and aging was carried out at 230 ° C. until the resin acid value became 11 or less. Then, after cooling to room temperature, 340.2 parts of xylene was added (hereinafter, this mixture is referred to as polyester PE-1).

The polyester contained in this polyester PE-1 has a number average molecular weight of 3200 as measured by GPC (gel filtration column chromatography), a solid content of polyester PE-1 of 60.0%, and a non-solid content. The content was 40% and the hydroxyl value was 100.0 mgKOH / g.

Production Example 6. 348.0 parts of xylene was charged into a reaction flask equipped with an acrylic resin synthesis thermometer, a stirrer, a nitrogen inlet, a reflux tube and a dropping funnel, and the temperature was raised to 85 ° C. And 210.0 parts of methyl methacrylate, 143.0 parts of butyl methacrylate,
2-ethylhexyl methacrylate 70.0 parts, styrene 60.0 parts, acrylic acid 7.0 parts, 2-hydroxyethyl methacrylate 110.0 parts, azobisisobutyronitrile 11.0 parts, dimethylacetamide 30.0 parts The mixed solution was continuously added dropwise over 2 hours and then polymerized at 85 ° C. for 1 hour. Then, a mixed solution prepared by dissolving 1.0 part of azobisisobutyronitrile in 10.0 parts of dimethylacetamide was added, and a polymerization reaction was further performed at 85 ° C. for 5 hours to complete the reaction (hereinafter, this reaction completion liquid Is referred to as acrylic resin AC-1).

The resulting acrylic resin AC-1 had a solid content of 60.1% and a non-solid content of 39.9%, and the acrylic resin contained therein had a number average molecular weight of 11,000 as measured by GPC and a hydroxyl group. Value is 79.0mgKOH /
It was a characteristic of g.

(C) Synthesis of dispersion paste Production Examples 7 to 13. Inorganic pigment dispersion paste synthetic titanium dioxide "Tyoxide TR92 (manufactured by DuPont)" at a compounding ratio as shown in Table 1 was used as PA-1 obtained in Production Example 1 or a commercially available dispersant "Solspers 300".
0 (manufactured by Zeneca, acid value; 30 to 35 mg KOH / g)
(Hereinafter referred to as PA-2), "and" Disperbyk
110 (manufactured by Big Chemie) (hereinafter referred to as PA-3) "
Or a dispersant having the basic functional group of PB-3 obtained in Production Example 4,
And the solvent were uniformly mixed, and the pigment was dispersed with a paint shaker (manufactured by Red Devil Co.) to prepare (inorganic pigment) dispersion pastes P-1 to P5 and PC-1 to PC-2. Table 1 shows the physical properties of the obtained (inorganic pigment) dispersion paste.

The addition amount of the dispersant in the table is the solid content of the pigment dispersant, that is, the addition amount converted into the pigment dispersible compound contained therein, and the viscosity of the dispersion paste is Brookfield viscometer "B type". Viscometer "(manufactured by Tokyo Keiki Co., Ltd.)
The stability of the dispersion paste is stored at 50 ° C. for 5 days, and the viscosities at the initial stage and after 5 days are measured by a B-type viscometer. The result judged to be good was shown.

[0043]

[Table 1]

Production Examples 14-28. Organic pigment dispersion paste synthetic carbon black "FW200 (manufactured by Degussa)", copper phthalocyanine blue "Heliogen Blue L6700F (BAS
Company F) ", dioxazine violet" Hostaperm Vi
"Olet RLS (manufactured by Hoechst)" at PB-1 to PB-obtained in Production Examples 2 to 4 at the compounding ratios shown in Tables 2 and 3.
3 or a commercially available dispersant "Disperbyk 161"
(Manufactured by Big Chemie) (hereinafter referred to as PB-4) "," E
FKA-46 (manufactured by EFKA Chemical Co., amine value; 17
21 mg KOH / g), hereinafter referred to as PB-5) ”, a dispersant having a basic functional group, or a dispersant having an acidic functional group of PA-1 obtained in Production Example 1, and a solvent. Were uniformly mixed, and the pigment was dispersed with a paint shaker (manufactured by Red Devil Co.) to produce (organic pigment) dispersion pastes P-6 to P13 and PC-3 to PC-6. The physical properties of the obtained (organic pigment) dispersion paste are shown in Tables 2 and 3.

The amount of the dispersant added in the table has the same meaning as the viscosity of the dispersion paste and the stability of the dispersion paste as in Table 1.

[0046]

[Table 2]

[0047]

[Table 3]

(D) Evaluation of Prevention of Color Separation Examples 1 to 14 and Comparative Examples 1 to 8 Preparation of Coating Composition Inorganic pigment dispersion paste obtained in Production Examples 7 to 13 and Production Examples 14 to 28. Table 4 shows the organic pigment dispersion paste
Melamine resin "Uvan 220", which was used for producing the solvent and the dispersion paste according to the coating composition of No. 6 to No. 6
(60% solid content, manufactured by Mitsui Toatsu Chemicals, Inc.) and a leveling agent "Modaflow" (10% xylene solution, manufactured by Monsanto Co., Ltd.) were mixed to prepare a coating composition. Then, the obtained coating composition was treated with Ford Cup NO. Dilute thinner (xylene / 2) so that viscosity becomes 25 seconds (25 ° C) at 4
-Methoxypropyl acetate = 1/1 weight ratio). After spray-coating each coating composition obtained above onto a zinc phosphate-treated steel sheet having a thickness of 0.6 mm, it is further coated by flow coating and baked at 140 ° C. for 30 minutes to give a dry film thickness of about 40.
Each test coated plate of μm was obtained. With respect to the obtained test coated plate, the color difference between the adhesion test, spray coating and flow coating was observed, and the ability to prevent color separation was evaluated. The above results are shown in Table 4 to
6 shows.

The adhesion of the coating film was evaluated by the adhesion test in accordance with JIS K5400 8.5.2, and the quality was judged. The color difference (ΔE) between the spray coating and the flow coating was a color difference meter (CR-Minolta Co., Ltd.). 200) and evaluated.

[0050]

[Table 4]

[0051]

[Table 5]

[0052]

[Table 6]

As can be seen from Tables 4 to 6, coating compositions prepared using the organic pigment treated with the dispersant having a basic functional group of the present invention and the inorganic pigment treated with the dispersant having an acidic functional group. It can be seen that the coating film obtained by applying the product has less color separation as compared with the conventional coating films.

─────────────────────────────────────────────────── --- Continuation of the front page (56) References JP-A-5-59318 (JP, A) JP-A-5-59297 (JP, A) JP-A-2-56230 (JP, A) JP-A-64- 51469 (JP, A) JP 57-50535 (JP, A) JP 5-271593 (JP, A) JP 5-65448 (JP, A) JP 6-184474 (JP, A) JP-A-56-118462 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) C09C 3/10 C09C 1/36 C09D 7/12

Claims (8)

(57) [Claims] 1. A treated pigment comprising an organic pigment treated with a dispersant having a basic functional group and an inorganic pigment treated with a dispersant having an acidic functional group. 2. The treated pigment according to claim 1, wherein the dispersant having a basic functional group and the dispersant having an acidic functional group are polymer dispersants. 3. The treated pigment according to claim 1, wherein the dispersant having a basic functional group is a urethane polymer dispersant. 4. The treated pigment according to claim 1, wherein the dispersant having an acidic functional group is a polymer dispersant having a carboxylic acid or a salt thereof or a sulfonic acid or a salt thereof. 5. A coating composition comprising the treated pigment according to any one of claims 1 to 4, a solvent and a resin. 6. The resin according to claim 5, which is a urethane, acrylic, polyester or alkyd resin.
Coating composition. 7. The coating composition according to claim 1, wherein the inorganic pigment is titanium dioxide. 8. The coating composition according to claim 1, wherein the organic pigment is phthalocyanine, dioxazine violet or carbon black.