TWI870006B - Method for producing branched polyester, solvent-type pigment dispersion composition and solvent-type coating composition containing the branched polyester - Google Patents

Abstract

Subject The present invention provides a solvent-type pigment dispersion composition comprising a resin having good compatibility with various pigment dispersion slurries and/or various resins, and further provides a high-concentration solvent-type pigment dispersion composition. Solution A solvent-type pigment dispersion composition is a solvent-type pigment dispersion composition comprising a branched polyester (A), a pigment dispersion resin (B), a pigment (C) and an organic solvent (D), wherein the branched polyester (A) contains a polyol (a1) having a reactive functional group having three or more functions, a dicarboxylic acid and/or a dicarboxylic anhydride (a2), and a monoepoxy compound (a3) having a long-chain alkyl group as constituent components.

Description

Method for producing branched polyester, solvent-type pigment dispersion composition and solvent-type coating composition containing the branched polyester

The present invention relates to a solvent-type pigment dispersion composition and a solvent-type coating composition.

Generally, paints widely use organic and/or inorganic pigments for the purpose of coloring, light blocking, aesthetics, and rust protection. These pigments are dispersed to make a pigment dispersion composition (also called pigment dispersion slurry).

Prepare the pigment dispersion composition corresponding to the number of colors, mix them in a way that becomes the target color, and further add resins and additives corresponding to the performance (purpose) of the paint to produce the final coloring paint composition.

Here, when mixing multiple pigment dispersion compositions, or when mixing a resin and/or an additive with a pigment dispersion composition, the dispersion stability of the pigment is sometimes insufficient and re-agglomerates, or the fluidity deteriorates, or the color shifts or the gloss is insufficient when the coating is made. To solve this problem, various proposals have been made so far.

For example, Patent Documents 1 to 3 propose to add pigment derivatives with the same skeleton as the pigment to be dispersed during pigment dispersion, or to use pigments treated with such pigment derivatives, etc. However, the methods based on such proposals have the following disadvantages: not only the pigment dispersion effect is not sufficient, but also because a variety of pigment derivatives are required, the versatility is poor, and the manufacturing is expensive, etc.

In addition, for example, Patent Document 4 proposes a polyester resin prepared from an acid component and an alcohol component, wherein the acid component contains a straight-chain acid with a carbon number of 12 or more in an amount of 25% by weight or less based on the total monomer amount of the polyester resin as a pigment dispersing resin, but the compatibility and other properties are not sufficient.

In addition, it is expected that the required coating appearance will become more and more diverse in the future, and correspondingly, the pigment dispersion performance for various color materials will be required.

In addition, in recent years, considering the protection of the earth's environment, the coating industry urgently needs to reduce the amount of organic solvents in coatings to decompose their high solid components. As a method of decomposing high solid components, research is usually conducted in the direction of reducing the viscosity of coating resins by lowering the molecular weight. However, if the molecular weight of the resin is reduced, problems such as reduced curing properties or reduced coating film performance will occur.

As a method to achieve high solid composition of coatings, in addition to lowering the molecular weight of coating resins, high pigment concentration of coatings can also be cited (reducing the amount of resin used to disperse the same amount of pigment). However, if you want to make the coating highly pigment-concentrated, there will be the following problems: it is easy to cause the viscosity of the pigment dispersion composition, the aggregation of pigments in the pigment dispersion composition and/or the coating, and the poor dilution (let down) stability during coating, etc., making it difficult to obtain a stable pigment dispersion composition and/or coating.

[Prior Art Literature] [Patent Literature]

Patent document 1: Japanese Patent Publication No. 59-96175

Patent document 2: Japanese Patent Publication No. 02-36252

Patent document 3: Japanese Patent Publication No. 10-81849

Patent document 4: Japanese Patent Publication No. 8-507571

The problem that this invention aims to solve is to provide a solvent-type pigment dispersion composition containing a resin that has good compatibility with various resins, and further to provide a high-concentration solvent-type pigment dispersion composition.

Under such circumstances, the inventors of the present invention have made great efforts to study and found that the above-mentioned problem can be solved by using a solvent-type pigment dispersion composition containing a certain amount of branched polyester (A) with a specific structure. Moreover, the inventors of the present invention have found, based on a large number of erroneous attempts, that by using a branched polyester with a specific structure and characteristic value, a branched polyester resin with good compatibility (solubility) with relatively low-polarity solvents and resins can be provided, and thus a relatively high-concentration solvent-type pigment dispersion composition can be provided. The present invention is based on this novel insight.

Therefore, the present invention provides the following items.

Item 1. A solvent-type pigment dispersion composition, which is a solvent-type pigment dispersion composition containing a branched polyester (A), a pigment dispersing resin (B), a pigment (C) and an organic solvent (D), wherein the branched polyester (A) contains a polyol (a1) having a reactive functional group with three or more functions, a dicarboxylic acid and/or a dicarboxylic anhydride (a2), and a monoepoxy compound (a3) having a long-chain alkyl group as constituent components.

Item 2. A solvent-type pigment dispersion composition as described in Item 1 above, wherein the branched polyester (A) further contains a chain extender (a4) as a constituent component.

Item 3. A solvent-type pigment dispersion composition as described in item 1 or 2 above, wherein the acid value of the branched polyester (A) is less than 10 mgKOH/g, the number average molecular weight is 500 to 50,000, the hydroxyl value is 1 to 200 mgKOH/g, and the degree of branching is 2.5 to 7.

Item 4. A solvent-type pigment dispersion composition as described in any one of items 1 to 3 above, wherein the monoepoxy compound (a3) is a monoepoxy compound having a carbon number of 6 or more.

Item 5. A solvent-type pigment dispersion composition as described in any one of Items 1 to 4 above, which contains 5 to 70% by mass of branched polyester (A) based on the solid component of the solvent-type pigment dispersion composition.

Item 6. A solvent-type pigment dispersion composition as described in any one of Items 1 to 5 above, which contains 5 to 70% by mass of pigment (C) based on the total mass of the solvent-type pigment dispersion composition.

Item 7. A solvent-type coating composition obtained by mixing a plurality of (multiple colors) solvent-type pigment dispersion compositions as described in any one of Items 1 to 6 above.

Item 8. A method for manufacturing a solvent-based paint composition, which comprises preparing a plurality of (multiple colors) solvent-based pigment dispersion compositions as described in any one of items 1 to 6 above, and adding the plurality of solvent-based pigment dispersion compositions into the same paint tank for mixing to adjust the color.

Item 9. A method for producing a branched polyester, which is a method for producing a branched polyester (A), comprising the steps of performing step 1-1 and step 1-2 in sequence: step 1-1: reacting a component comprising a polyol (a1) having a reactive functional group having three or more functional groups with a dicarboxylic acid and/or a dicarboxylic anhydride (a2) to form an intermediate product; step 1-2: reacting a component comprising the intermediate product with a monoepoxy compound (a3) having a long-chain alkyl group.

Item 10. The method for producing branched polyester as described in Item 9 above, wherein the following steps are included after the above steps 1-1 and 1-2: Step 1-3: a step of further reacting the components containing the chain extender (a4).

Item 11. A method for producing a branched polyester as described in Item 9 above, wherein the acid value of the polyol (a1) having three or more reactive functional groups is less than 10 mgKOH/g.

Item 12. A method for producing a branched polyester, which is a method for producing a branched polyester (A), comprising the step of performing step 2-1: Step 2-1: a step of reacting components comprising a polyol (a1) having a reactive functional group having three or more functions, a dicarboxylic acid and/or a dicarboxylic anhydride (a2), and a monoepoxy compound (a3) having a long-chain alkyl group simultaneously.

Item 13. A method for producing a branched polyester as described in Item 12, wherein the method comprises the following steps after the aforementioned step 2-1: Step 2-2: a step of further reacting the components containing the chain extender (a4).

Item 14. A method for producing a branched polyester as described in any one of Items 9 to 13 above, wherein the acid value of the polyol (a1) having three or more reactive functional groups is less than 10 mgKOH/g.

Item 15. A method for producing a solvent-type pigment dispersion composition, which is obtained by mixing the branched polyester (A) obtained by the production method of any one of items 9 to 14 above, the pigment dispersion resin (B), the pigment (C) and the organic solvent (D), and then using a medium to disperse the pigment.

Item 16. A method for producing a solvent-type pigment dispersion composition as described in Item 15 above, wherein the solvent-type pigment dispersion composition contains 5 to 70% by mass of branched polyester (A) based on the solid component of the solvent-type pigment dispersion composition.

Item 17. A method for producing a solvent-type pigment dispersion composition as described in Item 15 above, wherein the solvent-type pigment dispersion composition contains 5 to 70% by mass of pigment based on the total mass of the solvent-type pigment dispersion composition.

According to the present invention, a solvent-type pigment dispersion composition and/or solvent-type coating composition with excellent compatibility (including dispersion stability and storage stability) can be obtained. In addition, high solid composition differentiation (high concentration) of the solvent-type pigment dispersion composition and/or solvent-type coating composition can be achieved, and a coating film with excellent finish can be obtained.

The present invention is described in detail below.

In addition, the present invention is not limited to the following implementation methods, and should be understood to include various variations that are implemented within the scope of the present invention.

Solvent-type pigment dispersion composition

In one embodiment, the present invention provides a solvent-type pigment dispersion composition containing a branched polyester (A), a pigment dispersing resin (B), a pigment (C) and an organic solvent (D).

Branched polyester (A)

The branched polyester (A) contains as constituents a polyol (a1) having a reactive functional group having three or more functional groups, a dicarboxylic acid and/or a dicarboxylic anhydride (a2), and a monoepoxy compound (a3) having a long-chain alkyl group. In the present invention, the branched polyester (A) contains as constituents a component comprising component (a1), component (a2), and component (a3), which means that the branched polyester (A) is obtained by a method comprising a step of (co)polymerizing raw materials comprising component (a1), component (a2), and component (a3). Here, the "step of (co)polymerizing the raw materials including component (a1), component (a2) and component (a3)" includes not only the step of copolymerizing the raw materials including all of the above components (a1), component (a2) and component (a3) by a one-stage reaction, but also the step of first reacting a part of the above components (a1), component (a2) and component (a3) and then reacting the obtained reaction product with the remaining components in a multi-stage reaction.

Polyols with three or more reactive functional groups (a1)

The above-mentioned polyol (a1) having three or more reactive functional groups is a polyol having three or more reactive functional groups and two or more hydroxyl groups.

The reactive functional group is specifically a functional group selected from the group consisting of hydroxyl group, carboxyl group, amine group and thiol group.

Among them, as the above-mentioned component (a1), it is particularly preferred that all reactive functional groups are hydroxyl groups and the compound has 3 or more (trifunctional) hydroxyl groups.

Examples of polyols having trifunctional hydroxyl groups include glycerol, trihydroxymethylpropane, trihydroxymethylethane, trihydroxymethylbutane, 3,5,5-trimethyl-2,2-dihydroxymethylhexane-1-ol, 1,2,6-hexanetriol, trihydroxyethyl isocyanurate, etc., and one type may be used alone or two or more types may be used in combination.

Examples of polyols having tetrafunctional hydroxyl groups include erythritol, pentaerythritol, di(trihydroxymethylpropane), diglycerol, and di(trihydroxymethylethane), and one or more of them may be used alone or in combination.

Examples of polyols having hydroxyl groups with five or more functional groups include dipentatriol, tripentatriol, xylitol, and sorbitol, and one or more of these can be used alone or in combination.

In addition, examples of polyols having two or more functional hydroxyl groups and one or more functional carboxyl groups include dihydroxycarboxylic acids (e.g., dihydroxymethylacetic acid, dihydroxymethylbutyric acid, dihydroxymethylpropionic acid, dihydroxymethylbutyric acid, dihydroxymethylvaleric acid), trihydroxycarboxylic acids, and dihydroxydicarboxylic acids, and one or more of these can be used alone or in combination.

In addition, as a polyol having two or more functional hydroxyl groups and one or more functional amine groups, for example, dihydroxyamines (for example, diethanolamine, dipropanolamine) can be used alone or in combination of two or more.

Among them, from the perspective of reactivity, it is preferred to use a polyol having a trifunctional hydroxyl group.

In addition, bifunctional polyols and/or monofunctional alcohols can also be used in combination with the above-mentioned polyol (a1) having trifunctional or higher reactive functional groups as needed.

Examples of the bifunctional polyol include ethylene glycol, propylene glycol, diethylene glycol, 1,3-propanediol, tetraethylene glycol, triethylene glycol, dipropylene glycol, 1,4-butanediol, 1,3-butanediol, 2,3-butanediol, 1,2-butanediol, 2-methyl-1,3-propanediol, 3-methyl-1,2-butanediol, 2-butyl-2-ethyl-1,3-propanediol, 1,2-pentanediol, 1,5-pentanediol, 1,4-pentanediol, 2,4-pentanediol, 2,3-dimethyl-1,3-propanediol, butanediol, 3-methyl-4,3-pentanediol, 3-methyl-1,5-pentanediol, 2,2,4-trimethyl-1,3-pentanediol, 1,6-hexanediol, 1,5-hexanediol, 1,4-hexanediol, 2,5-hexanediol, neopentyl glycol, 1,4-cyclohexanedimethanol, tricyclodecanedimethanol, hydroxy neopentyl glycol pivalate, hydrogenated bisphenol A, hydrogenated bisphenol F, dihydroxymethyl propionic acid and other diols; polylactone diols formed by adding lactone compounds such as ε-caprolactone to these diols; ester diol compounds such as bis(hydroxyethyl) terephthalate; alkylene oxide adducts of bisphenol A, polyethylene glycol, polypropylene glycol, polybutylene glycol and other polyether diol compounds, etc., can be used alone or in combination of two or more.

Examples of monofunctional alcohols include methanol, ethanol, propanol, butanol, stearyl alcohol, 2-phenoxyethanol, etc., and one type may be used alone or two or more types may be used in combination.

As a component constituting the branched polyester (A), in terms of low branching, it is preferred that it substantially does not contain bifunctional polyols and/or monofunctional alcohols, and it is particularly preferred that it substantially does not contain monofunctional alcohols. The above-mentioned "substantially does not contain" means that the content of the polyol (a1) having trifunctional or more reactive functional groups is preferably 10 mol% or less, more preferably 5 mol% or less, further preferably 1 mol% or less, and particularly preferably 0 mol%.

Dicarboxylic acid and/or dicarboxylic anhydride (a2)

As the above-mentioned dicarboxylic acid and/or dicarboxylic anhydride (a2), for example, phthalic acid, isophthalic acid, terephthalic acid, succinic acid, glutaric acid, adipic acid, azelaic acid, sebacic acid, tetrahydrophthalic acid, hexahydrophthalic acid, succinic acid, fumaric acid, itaconic acid and other dicarboxylic acids, or their anhydrides, etc., can be used alone or in combination of two or more. Among them, from the viewpoint of reactivity and the viewpoint that no condensation water is generated during the reaction, dicarboxylic anhydride is preferred. By inhibiting condensation water, for example, when an isocyanate compound is used as a chain extender (a4), the reaction between condensation water and isocyanate can be inhibited, resulting in partial deactivation of the isocyanate group, so it is preferred.

In addition, trifunctional or higher polycarboxylic acids and/or monofunctional carboxylic acids may also be used together with the above-mentioned dicarboxylic acids and/or dicarboxylic anhydrides (a2) as needed.

Examples of trifunctional or higher polycarboxylic acids include trimellitic acid, pyromellitic acid, benzophenonetetracarboxylic acid, 1,3,5-benzenetricarboxylic acid, ethylene glycol di(dehydrated trimellitic acid ester), glycerol tri(dehydrated trimellitic acid ester), 1,2,3,4-butanetetracarboxylic acid, 1,4,5,8-naphthalenetetracarboxylic acid, etc. One type may be used alone or two or more types may be used in combination.

Examples of monofunctional carboxylic acids include acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, heptanoic acid, caprylic acid, stearic acid, oleic acid, linoleic acid, cyclohexanecarboxylic acid, and benzoic acid. One type may be used alone or two or more types may be used in combination.

As a component constituting the branched polyester (A), the monofunctional carboxylic acid is preferably less in terms of promoting the high molecular weight (hydrophobicity) of the branched part. Preferably, the content of the monofunctional carboxylic acid is preferably 50 mol% or less, more preferably 20 mol% or less, further preferably 10 mol% or less, and particularly preferably 0 mol% based on the content of the dicarboxylic acid and/or dicarboxylic anhydride (a2).

In addition, from the perspective of inhibiting gelation, it is preferred that the polycarboxylic acid with three or more functional groups is substantially free of content. The above-mentioned "substantially free of content" means that the content of dicarboxylic acid and/or dicarboxylic anhydride (a2) is preferably 10 mol% or less, more preferably 5 mol% or less, further preferably 1 mol% or less, and particularly preferably 0 mol%.

Monoepoxy compounds with long-chain alkyl groups (a3)

The monoepoxy compound (a3) having a long-chain alkyl group is a monoepoxy compound having an alkyl group with 4 or more carbon atoms, which can make the branched polyester (A) hydrophobic and improve the compatibility. Specifically, for example, there can be cited: glycidyl trimethylacetate, glycidyl hexanoate, glycidyl cyclohexanecarboxylate, glycidyl 2-ethylhexanoate, glycidyl isononanoate, glycidyl caprate, glycidyl undecanoate, glycidyl laurate, glycidyl myristic acid, glycidyl palmitate, glycidyl stearate, Cardura E10 (manufactured by Japan Epoxy Resin Co., Ltd., neodecanoic acid monoglycidyl) and other glycidyl ethers; glycidyl ethers such as butyl glycidyl ether, phenyl glycidyl ether, and decyl glycidyl ether; and α-olefin monocyclic oxides such as styrene oxide and AOEX24 (manufactured by Daicel Chemical Industries, α-olefin monocyclic oxide mixture).

In addition, the above-mentioned alkyl groups with more than 4 carbon atoms also include those having substituents such as hydroxyl groups. Specific examples of such compounds include 1,2-epoxyoctanol, hydroxyoctyl glycidyl ether, etc.

The monocyclic oxide compound (a3) having a long chain alkyl group can be used alone or in combination of two or more. Among them, from the viewpoint of compatibility, the lower limit of the carbon number is preferably 3 or more, and more preferably 6 or more. As the range of the carbon number of the monocyclic oxide compound (a3), for example, a monocyclic oxide compound having a alkyl group with a carbon number of 3 or more and 30 or less is preferred, a alkyl group with a carbon number of 6 or more and 30 or less is more preferred, and a alkyl group with a carbon number of 8 or more and 20 or less is further preferred.

Chain extender (a4)

The branched polyester (A) may further contain a chain extender (a4) as part of the constituent components. As the chain extender (a4), any compound having a reactive functional group that can connect the branched polyester (A) to each other can be preferably used. In order to prevent gelation, the reactive functional group is preferably present in two in the compound. Specifically, for example, chain extenders such as diisocyanate compounds, carbonate compounds such as diphenyl carbonate, and silicate compounds can be used. Among them, diisocyanate compounds are preferred because they can improve physical properties by generating urethane bonds in the resin skeleton.

As the above-mentioned diisocyanate compound, any known compound can be used without limitation as long as it has two isocyanate groups. Specifically, examples thereof include 2,4-toluene diisocyanate, a mixture of 2,4-toluene diisocyanate and 2,6-toluene diisocyanate, diphenylmethane diisocyanate, 1,5-naphthalene diisocyanate, xylylene diisocyanate, hydrogenated xylylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate and other known diisocyanates. One type can be used alone or two or more types can be used in combination.

As the carbonate compounds mentioned above, specifically, for example, diphenyl carbonate, ditolyl carbonate, bis(chlorophenyl) carbonate, m-tolyl carbonate, dinaphthyl carbonate, dimethyl carbonate, diethyl carbonate, dibutyl carbonate, ethylene carbonate, dipentyl carbonate, dicyclohexyl carbonate, etc. can be cited. In addition, carbonate compounds containing the same or different hydroxyl compounds derived from hydroxyl compounds such as phenols and alcohols can be cited, and one type can be used alone or two or more types can be used in combination.

As the above-mentioned silicate compound, specifically, for example, tetramethoxysilane, dimethoxydiphenylsilane, dimethoxydimethylsilane, diphenyldihydroxysilane, etc. can be cited, and one type can be used alone or two or more types can be used in combination.

The preferred implementation method of the method for producing the branched polyester (A) is described in detail in the following section "Method for producing branched polyester (A)".

Method for producing branched polyester (A)

The branched polyester (A) obtained by the production method of the present invention contains as constituent components a polyol (a1) having a reactive functional group with three or more functional groups, a dicarboxylic acid and/or a dicarboxylic anhydride (a2), and a monoepoxy compound (a3) having a long-chain alkyl group, and further contains a chain extender (a4) as a constituent component as necessary.

In the preferred embodiment of the present invention, as a method for producing the branched polyester (A), the following two methods (stage reaction and batch reaction) can be used, and both can be preferably used.

Manufacturing method of the first sample (stage reaction)

The first aspect of the production method (stage reaction) is a method for producing a branched polyester comprising the steps of performing step 1-1 and step 1-2 in sequence: step 1-1: a step of reacting a component comprising a polyol (a1) having a reactive functional group having three or more functions with a dicarboxylic acid and/or a dicarboxylic anhydride (a2) to form an intermediate product; step 1-2: a step of reacting a component comprising the aforementioned intermediate product with a monoepoxy compound (a3) having a long-chain alkyl group.

Furthermore, it is preferred that the following steps are included after the above steps 1-1 and 1-2: Step 1-3: a step of further reacting the components containing the chain extender (a4).

In addition, the manufacturing method of the present invention also includes adding other steps before, after and/or during the above-mentioned step 1-1, step 1-2 and step 1-3 which can be applied as needed.

Second aspect manufacturing method (batch reaction)

The second aspect of the production method (batch reaction) is a method for producing branched polyesters comprising the step of performing step 2-1: Step 2-1: a step of reacting components including a polyol (a1) having a reactive functional group having three or more functions, a dicarboxylic acid and/or a dicarboxylic anhydride (a2), and a monoepoxy compound (a3) having a long-chain alkyl group simultaneously.

Furthermore, it is preferred that the following step is included after the above step 2-1: Step 2-2: a step of further reacting the components including the chain extender (a4).

In addition, the manufacturing method of the present invention also includes adding other steps before, after and/or during the above-mentioned step 2-1 and the step 2-2 which can be applied as needed.

In the present invention, any manufacturing method can be preferably used, but from the perspectives of fewer steps, energy saving, inhibiting the high molecular weight of the resin, and inhibiting condensation water, the second manufacturing method (batch reaction) can be preferably used.

The synthesis conditions in the first and second aspects are not particularly limited. For example, the synthesis can be performed in the following manner: in the above steps 1-1 to 1-2 and step 2-1, heating is performed at 90 to 250°C for 5 to 10 hours to perform an esterification reaction between a hydroxyl group and a carboxyl group (including an ester exchange reaction) and/or an esterification reaction between an epoxide group and a carboxyl group. As a catalyst at this time, known catalysts such as dibutyltin oxide, antimony trioxide, zinc acetate, manganese acetate, cobalt acetate, calcium acetate, lead acetate, tetrabutyl titanate, and tetraisopropyl titanate can be used.

In the reaction of the chain extender (a4) in step 1-3 and step 2-2 (for example, the urethanization reaction of a hydroxyl group and an isocyanate group), which can be carried out as needed, a known catalyst (for example, an organic tin catalyst, a bismuth catalyst, a lead catalyst, a zinc catalyst, etc.) can also be used, for example, by heating at 60 to 200°C (preferably 60 to 100°C from the viewpoint of suppressing high molecular weight) for 1 to 10 hours to carry out the reaction.

The components constituting the branched polyester (A) are described in detail below.

Polyols with three or more reactive functional groups (a1)

As the above-mentioned polyol (a1) having reactive functional groups of three or more functional groups, dicarboxylic acid and/or dicarboxylic anhydride (a2), monoepoxy compound (a3) having a long-chain alkyl group, and chain extender (a4), those described in the above-mentioned "branched polyester (A)" can be used.

As a characteristic value of the branched polyester (A), from the viewpoint of satisfying various coating properties by reacting with a crosslinking agent during coating, the hydroxyl value of the branched polyester (A) is preferably 1 to 200 mgKOH/g, more preferably 10 to 140 mgKOH/g, and further preferably 20 to 100 mgKOH/g.

In addition, the acid value of the branched polyester (A) is 50 mgKOH/g or less, preferably 15 mgKOH/g or less, more preferably 10 mgKOH/g or less, further preferably 0.1 mgKOH/g or more and 10 mgKOH/g or less, and particularly preferably 0.1 mgKOH/g or more and 5 mgKOH/g or less.

The branched polyester (A) of the present invention is a low-polarity resin that improves compatibility in solvent-type pigment dispersion compositions, so a low acid value that increases polarity is preferred.

In addition, the number average molecular weight of the branched polyester (A) is preferably about 500 to 50,000, more preferably about 1,000 to 10,000, and further preferably about 1,400 to 5,000.

In addition, from the perspective of compatibility and resin synthesis reaction, the branching degree of the branched polyester (A) is preferably 2.5 or more and 7 or less, more preferably 3.0 or more and 6.5 or less, and further preferably 3.5 or more and 5.5 or less.

Here, the "branching degree" of the present invention is the average theoretical value of one resin molecule when all the resin raw materials are reacted, and is calculated based on the number of branches of the resin skeleton based on the polyol (a1) and the chain extender (a4), without considering the branching at the end of the resin (for example, the terminal alkyl group of the monoepoxy compound has a branched structure, etc.).

Furthermore, the number of reactive functional groups of the polyol (a1) and the number of connected terminals when the resin terminals are connected to each other using a chain extender based on the chain extender (a4) are subtracted.

Specifically, for example, when 1 mol of trifunctional polyol, 3 mol of dicarboxylic acid, and 3 mol of monoepoxy compound are used as raw materials for branched polyester, the branching degree of the resin is 3. When 0.5 mol of diisocyanate is further used as a chain extender in the additional reaction, the branching degree is 4.

In addition, the branching degree of a resin with no branches in the resin skeleton (two ends) is 2.

In this specification, the number average molecular weight and weight average molecular weight are values obtained by converting the retention time (retention capacity) measured using a gel permeation chromatograph (GPC) into the molecular weight of polystyrene by the retention time (retention capacity) of a standard polystyrene of known molecular weight measured under the same conditions. Specifically, "HLC8120GPC" (trade name, manufactured by Tosoh Corporation) was used as a gel permeation chromatograph, and "TSKgel G-4000HXL", "TSKgel G-3000HXL", "TSKgel G-2500HXL" and "TSKgel G-2000HXL" (trade names, all manufactured by Tosoh Corporation) were used as columns. The measurement was performed under the conditions of tetrahydrofuran as the mobile phase, a measurement temperature of 40°C, a flow rate of 1mL/min and a detector RI.

The amounts of the polyol (a1) having reactive functional groups with three or more functional groups, the dicarboxylic acid and/or dicarboxylic anhydride (a2), the monoepoxy compound (a3) having a long-chain alkyl group, and the chain extender (a4) are as follows.

As the amount of component (a2) to be formulated, based on the total amount of component (a1), component (a2) is preferably 100 mol% or more, more preferably 100 mol% to 500 mol%, and further preferably 200 mol% to 400 mol%.

As the amount of component (a3), based on the total amount of component (a2), component (a3) is preferably 30 mol% to 300 mol%, more preferably 50 mol% to 200 mol%, and further preferably 75 mol% to 150 mol%.

The amount of component (a3) to be added based on the total amount of component (a1) is preferably 100 mol% or more, more preferably 100 mol% to 500 mol%, and even more preferably 200 mol% to 400 mol%.

In addition, the amount of component (a4) to be added is preferably 0 mol% to 300 mol%, more preferably 20 mol% to 200 mol%, and further preferably 40 mol% to 100 mol%, based on the total amount of component (a1).

Although the reason why the branched polyester (A) obtained by the manufacturing method of the present invention has excellent compatibility (dispersibility, storage stability) with various resin components is not known in detail, it is believed that it is due to the presence of relatively low-polarity alkyl components at the ends of the branched resins and the relatively low acid value (low polarity).

In addition, it is believed that the relatively low molecular weight helps with compatibility and high concentration.

In addition, the branched polyester obtained by the manufacturing method of the present invention can be preferably used as a branched polyester suitable for solvent-type pigment dispersion composition, so it can also be said to be a branched polyester suitable for solvent-type pigment dispersion composition.

Pigment dispersing resin (B)

The pigment dispersing resin is not particularly limited, and preferably acrylic resins, polyester resins other than component (a1), alkyd resins, polyether resins, urethane resins, etc., preferably those having anionic, cationic, and non-ionic adsorption functional groups. In addition, commercially available products may also be used.

Pigment (C)

As the above-mentioned pigment (C), known pigments can be used without limitation, for example: coloring pigments, physical pigments, glossy pigments, etc.

類顏料、二酮吡咯并吡咯類顏料等。 Examples of the coloring pigment include titanium oxide, zinc oxide, carbon black, red iron, molybdenum red, Prussian blue, cobalt blue, azo pigments, phthalocyanine pigments, quinacridone pigments, isoindoline pigments, vat pigments, perylene pigments, dioxane pigments, and the like.

Pigments, diketopyrrolopyrrole pigments, etc.

Examples of the above-mentioned physical pigments include clay, kaolin, barium sulfate, barium carbonate, calcium carbonate, talc, silicon dioxide, aluminum oxide white, etc.

Examples of the above-mentioned bright pigments include aluminum (including vapor-deposited aluminum), copper, zinc, brass, nickel, glass flakes, aluminum oxide, mica, aluminum oxide coated with titanium oxide and/or iron oxide, and mica coated with titanium oxide and/or iron oxide. Among aluminum pigments, there are non-leafing aluminum pigments and leafing aluminum pigments, both of which can be used.

Organic solvent (D)

烷、乙二醇單甲醚、乙二醇單乙醚、乙二醇單乙醚、乙二醇單丁醚、二乙二醇等醚類溶劑；乙酸乙酯、乙酸正丁酯、乙酸異丁酯、乙二醇單甲醚乙酸酯、丁基卡必醇乙酸酯等酯類溶劑；甲基乙基酮、甲基異丁基酮、二異丁基酮等酮類溶劑；乙醇、異丙醇、正丁醇、二級丁醇、異丁醇等醇類溶劑；Ecuamide(商品名，出光興產股份有限公司製)、N,N-二甲基甲醯胺、N,N-二甲基乙醯胺、N-甲基甲醯胺、N-甲基乙醯胺、N-甲基丙醯胺、N-甲基-2-吡咯啶酮等醯胺類溶劑等以往公知之溶劑。它們可單獨使用1種或併用2種以上。 Examples of the organic solvent (D) include hydrocarbon solvents such as n-butane, n-hexane, n-heptane, n-octane, cyclopentane, cyclohexane, mineral oil, and cyclobutane; aromatic solvents such as solvent oil, toluene, and xylene; ketone solvents such as methyl isobutyl ketone; n-butyl ether, dimethylbenzene, and the like;

Ether solvents include ether solvents such as oxane, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, and diethylene glycol; ester solvents such as ethyl acetate, n-butyl acetate, isobutyl acetate, ethylene glycol monomethyl ether acetate, and butyl carbitol acetate; ketone solvents such as methyl ethyl ketone, methyl isobutyl ketone, and diisobutyl ketone; alcohol solvents such as ethanol, isopropanol, n-butanol, dibutyl alcohol, and isobutanol; amide solvents such as Ecuamide (trade name, manufactured by Idemitsu Kosan Co., Ltd.), N,N-dimethylformamide, N,N-dimethylacetamide, N-methylformamide, N-methylacetamide, N-methylpropionamide, and N-methyl-2-pyrrolidone, and the like, and the like. These may be used alone or in combination of two or more.

In addition, if it is a small amount, water can be contained within the range to be dissolved, preferably less than 10% by mass of the entire solvent, more preferably less than 5% by mass, and further preferably less than 1% by mass.

Other ingredients

The solvent-type pigment dispersion composition of the present invention may contain various resins, additives, etc. as other ingredients.

Examples of the above-mentioned resin include polyester resins other than branched polyester (A), acrylic resins, epoxy resins, polyether resins, alkyd resins, urethane resins, silicone resins, polycarbonate resins, silicate resins, chlorinated resins, fluorinated resins, and composite resins thereof.

類吸收劑、水楊酸衍生物類吸收劑、二苯甲酮類吸收劑等)、光穩定劑(例如，受阻胺類等)、增黏劑、消泡劑、表面調整劑、防沉澱劑、防鏽劑、螯合劑(乙醯丙酮等)、脫水劑、中和劑、塑化劑等公知之塗料用添加劑。 As the above-mentioned additive, for example, an ultraviolet absorber (for example, benzotriazole absorber, tri

The invention relates to coating additives which are known in the art, such as light stabilizers (such as light absorbers, salicylic acid derivative absorbers, benzophenone absorbers, etc.), light stabilizers (such as hindered amines, etc.), thickeners, defoamers, surface conditioners, anti-precipitation agents, anti-rust agents, chelating agents (such as acetylacetone), dehydrating agents, neutralizers, plasticizers, etc.

In addition, the solvent-type pigment dispersion composition of the present invention is a pigment dispersion composition for coloring, so it is preferred that it substantially does not contain a curing agent, and the curing agent is preferably mixed during the manufacture of the coating.

The solvent-type pigment dispersion composition of the present invention described above may be a composition containing one coloring pigment.

The solvent-type pigment dispersion composition of the present invention is a composition containing the aforementioned branched polyester (A), pigment dispersion resin (B), pigment (C) and organic solvent (D). The manufacturing method thereof is to mix the components including the pigment dispersion resin (B), pigment (C) and organic solvent (D), and disperse the pigment to prepare a liquid slurry. In addition, the branched polyester (A) can be prepared before and/or after the pigment dispersion, but it is preferably mixed with the components (B), (C) and (D) before the pigment dispersion, and the pigment is dispersed together with them.

As a method for dispersing the pigment, known methods can be used without limitation, for example, a bead mill, ultrasonic homogenizer, high pressure homogenizer, paint oscillator, ball mill, roller mill, sand mill, sand grinder, DYNO-MILL, Nanomizer and other dispersers can be used, and a dispersion method using a medium is particularly preferred.

The solid component of the solvent-based pigment dispersion composition of the present invention is preferably 20 to 85% by mass, more preferably 30 to 70% by mass, and further preferably 35 to 75% by mass.

In addition, the solvent-type pigment dispersion composition of the present invention is required to contain a high concentration of pigment. Based on the total mass of the solvent-type pigment dispersion composition, it is preferred to contain 5 to 70 mass% of pigment (C), more preferably 15 to 65 mass%, and even more preferably 20 to 60 mass%.

In addition, based on the solid components of the solvent-type pigment dispersion composition, it is preferred to contain 5 to 70 mass % of the branched polyester (A), more preferably 7 to 60 mass %, and even more preferably 10 to 55 mass %.

In addition, based on the solid component of the solvent-type pigment dispersion composition, it is preferred to contain 1 to 50 mass % of the pigment dispersion resin (B), more preferably 2 to 35 mass %, and even more preferably 3 to 20 mass %.

According to the present invention, by using a solvent-type pigment dispersion composition containing a certain amount of branched polyester (A) having a specific structure, the following problems can be solved: providing a solvent-type pigment dispersion composition containing a resin that has good compatibility with various pigment dispersion slurries and various resins, and further providing a high-concentration solvent-type pigment dispersion composition.

Solvent-based coating composition

As a second aspect of the present invention, a plurality of (multiple colors) of the above-mentioned solvent-based pigment dispersion compositions can be prepared, mixed in a manner to form a target color, and further mixed with a base coating, resin and/or additive corresponding to the target to produce a solvent-based coating composition. In addition, the above-mentioned base coating is a coating composition containing various resins and/or additives without coloring pigments, or a coating containing various white resins and/or additives, and can contain physical pigments as needed.

As a method for manufacturing the above-mentioned solvent-based paint composition, the solvent-based pigment dispersion composition (plural kinds) of the present invention and the base paint, resin and/or additives as required can be added to a mixing tank, and the mixture is fully stirred and mixed using a rotary stirring blade to obtain a colored paint composition.

In addition, the solvent-type pigment dispersion composition of the present invention has good compatibility, so it can also be preferably used in a mixing method (coloring method) that does not use a rotating stirring blade.

For example, in the above mixing step, the solvent-based pigment dispersion composition (plural kinds) of the present invention and the base paint, resin and/or additives as required can be added to the same paint tank, the paint tank cover is closed, and a mixing method (coloring method) of uniformly mixing the mixture using a vibrating tank is used to obtain a solvent-based paint composition.

By using the above mixing method, a paint tank as a product can be manufactured without using a mixing tank, so the paint can be manufactured efficiently and economically. In addition, the generation of cleaning solvents caused by cleaning the mixing tank can be reduced.

The above solvent-based coating composition is preferably finally mixed with a curing agent and applied to the coated object to form a coating film cross-linked by the curing agent. The curing agent is preferably melamine resin, polyisocyanate compound and/or blocked polyisocyanate compound, etc.

The above-mentioned solvent-based coating composition can be used, for example, without limitation, for coating purposes of automobiles, electrical products, steel furniture, office supplies, building materials, buildings, bridges, etc., excluding ink and inkjet applications.

Implementation example

The present invention is further described in detail below using manufacturing examples, implementation examples, and comparative examples, but the present invention is not limited thereto. "Parts" in each example represent parts by mass, and "%" represents mass %.

Production of branched polyester (A)

Implementation Example (1-1)

In a reactor equipped with a stirrer, reflux cooler, water separator and thermometer, add 136.5 parts of trihydroxymethylpropane, 444 parts of phthalic anhydride and 735 parts of monoglycidyl neodecanoate, and react at 180°C for 3 hours. (No condensation water is produced)

Then, 84 parts of hexamethylene diisocyanate were reacted at 100°C for 2 hours, and then "Swazol 1000" (trade name, manufactured by Cosmo Oil, an aromatic organic solvent) was added while cooling. As a result, a branched polyester (A-1) solution with an acid value of 3 mgKOH/g, a hydroxyl value of 83 mgKOH/g, a number average molecular weight of 2400, and a branching degree of 4.0 and a solid component content of 50% was obtained.

Implementation examples (1-16)

Add 137 parts of trihydroxymethylpropane and 444 parts of phthalic anhydride to a reactor equipped with a stirrer, reflux cooler, water separator and thermometer, and react at 180°C for 3 hours. (Produce a certain amount of condensation water)

Then, 735 parts of neodecanoic acid monoglycidyl ester was added and reacted at 180°C for 3 hours. Then, 84 parts of hexamethylene diisocyanate were reacted at 100°C for 2 hours, and "Swazol 1000" (trade name, made by Cosmo Oil, aromatic organic solvent) was added while cooling. As a result, a branched polyester (A-16) solution with an acid value of 3 mgKOH/g, a hydroxyl value of 83 mgKOH/g, a number average molecular weight of 2400, and a branching degree of 4.0 and a solid component content of 50% was obtained.

Implementation Examples (1-2) to (1-15), Comparative Examples (1-1) and (1-2)

Polyesters (A-2) to (A-15), (A-17) and (A-18) were produced in the same manner as in Example 1 except that the types and blending amounts were set as shown in Table 1 below. The characteristic values of the resins are shown in the table.

TMP: trihydroxymethylpropane

G: Glycerin

PE: Pentaerythritol

DMPA: dihydroxymethylpropionic acid

1,6HD: 1,6-hexanediol

HHPA: Hexahydrophthalic anhydride

PA: Phthalic anhydride

BA: Benzoic acid

NDGE: Neodecanoic acid monoglycidyl ester

BGE: n-butyl glycidyl ether

HMDI: Hexamethylene diisocyanate

IPDI: isophorone diisocyanate

The abbreviations in Table 1 above are as above.

Manufacturing Example 1 Manufacturing of pigment dispersion resin

Add 300 parts of "Swazol 1500" (trade name, manufactured by Cosmo Oil, aromatic organic solvent) to a production flask equipped with a thermometer, thermostat, stirrer, reflux cooler and dropping device, raise the temperature to 115°C, and dropwise add the monomer composition of the following composition over 3 hours while stirring and mixing in a nitrogen flow.

<Monomer composition>

<Catalyst mixture>

然後，於相同溫度下花1小時滴加上述催化劑混合液，於115℃熟成1小時後，添加「Swazol 1500」(商品名，Cosmo Oil公司製，芳香族類有機溶劑)，而獲得固體組分50%之顏料分散樹脂溶液。

Then, the catalyst mixture was added dropwise at the same temperature for 1 hour, and after ripening at 115°C for 1 hour, "Swazol 1500" (trade name, manufactured by Cosmo Oil Company, aromatic organic solvent) was added to obtain a pigment dispersion resin solution with a solid component of 50%.

Manufacturing of solvent-based pigment dispersion compositions

Example 1A

20g (solid component 10g) of the polyester resin (A-1) solution obtained in Example 1-1, 10g (solid component 5g) of the pigment dispersion resin solution obtained in Preparation Example 1, 25g of carbon black, and 30g of "Swazol 1000" (trade name, manufactured by Cosmo Oil, aromatic organic solvent) were added to a 225ml wide-mouthed glass bottle, 100g of glass beads with a diameter of about 1.5mm were added as a dispersion medium and sealed, and dispersed for 60 minutes using DASH2000-K DISPERSER (trade name, manufactured by LAU, vibration-type paint conditioner), thereby obtaining a solvent-type pigment dispersion composition (X-1A).

Example 1B

Replace 25g of carbon black in the solvent-type pigment dispersion composition (X-1A) of the above-mentioned Example 1A with 35g of red iron ore, and produce a solvent-type pigment dispersion composition (X-1B) of a different color in the same manner.

Examples 2A to 17A and Comparative Examples 1A to 3A

Except for the formulation (resin type and formulation amount) of Table 2 below, the solvent-type pigment dispersion compositions (X-2A) to (X-20A) are obtained in the same manner as the solvent-type pigment dispersion composition (X-1A) of Example 1A.

Examples 2B to 17B and Comparative Examples 1B to 3B

Except for the formulation (resin type and formulation amount) of Table 2 below, solvent-type pigment dispersion compositions (X-2B) to (X-20B) were obtained in the same manner as the solvent-type pigment dispersion composition (X-1B) of Example 1B.

That is, the pigment dispersion compositions (X-1A) to (X-20A) of the black series (A series) containing carbon black and the pigment dispersion compositions (X-1B) to (X-20B) of the red series (B series) containing red iron oxide are respectively manufactured.

In addition, the mixing amounts in Table 2 above are the values of the solid components.

In addition, the above Table 2 shows the results of the evaluation test described later. (Example 1C is the evaluation result of the coating containing the components of the solvent-type pigment dispersion composition of Example 1A and Example 1B respectively.

Other implementation examples and comparative examples are also evaluated in the same way)

The solvent-based pigment dispersion composition (solvent-based coating composition) of the present invention requires all evaluation tests to be qualified. "×" in each evaluation test means failure, and the rest means passing.

<Evaluation test>

Coating appearance

The pigment dispersion composition of the black series (A series) containing carbon black obtained in the embodiment and comparative example with a solid component of 100 parts of "Cera M Retan White" (trade name, acrylic/urethane weak solvent paint) manufactured by Kansai Paint Co., Ltd. and the pigment dispersion composition of the red series (B series) containing red iron oxide with a solid component of 10 parts were prepared, and the mixture was stirred in a disperser for 30 minutes to produce a coating composition (disperser stirred product).

Then, the coating was applied using an applicator in such a way that the dried coating film became 50 μm. After drying at room temperature for 3 days, the appearance of the coating film was visually evaluated based on the following criteria.

○: Both gloss and clarity are very good, △: Either the gloss or clarity is slightly poor, ×: Both the gloss and clarity are significantly poor.

In-can color tinting

With respect to 100 parts of the solid component of "Cera M Retan White" (trade name, acrylic/urethane weak solvent paint) manufactured by Kansai Paint Co., Ltd., the black series (A series) pigment dispersion composition containing carbon black obtained in the examples and comparative examples was mixed into the paint can in a manner that the solid component was 10 parts, and the red series (B series) pigment dispersion composition containing iron red was further mixed into the paint can in a manner that the solid component was 10 parts. Then, the lid was put on, and the can was shaken for 20 minutes to mix, thereby manufacturing the paint composition (tinting product in the can).

In addition, the same formulation was stirred in a disperser for 30 minutes to prepare a coating composition (disperser stirred product).

As described above, each coating composition mixed by the two methods was applied to a tinplate using an applicator within 1 hour after production so that the dry coating film became 50μm, and visual evaluation was performed based on the following criteria.

○: No color difference was observed between the color mixed product in the can and the product mixed by the disperser, △: A slight color difference was observed between the color mixed product in the can and the product mixed by the disperser, ×: A clear color difference was observed between the color mixed product in the can and the product mixed by the disperser.

Color grading stability (storage stability)

The coating composition (mixed by a disperser) produced in the above coating appearance evaluation test was sprayed on the tinplate within 1 hour after production (dry coating 50μm), and after drying at room temperature for 3 days, the same coating composition was used for coating using a brush and roller. Visual evaluation was performed based on the following criteria. In this evaluation, in addition to storage stability, color unevenness based on the type of coating (differences in shear speed, etc.) can also be observed.

○: There is no color difference on the painted surface using spray, brush, or roller.

△: Slight color difference was observed on the painted surface using spray, brush, and roller.

×: The color difference is clearly visible on the painted surface using spray, brush, or roller.

(without)

Claims (13)

A solvent-type pigment dispersion composition comprises a branched polyester (A), a pigment dispersing resin (B), a pigment (C) and an organic solvent (D), wherein the branched polyester (A) comprises a polyol (a1) having a reactive functional group having three or more functions, a dicarboxylic acid and/or a dicarboxylic anhydride (a2), and a monoepoxy compound (a3) having a long-chain alkyl group as constituent components; The solid content of the pigment dispersion composition is 20 to 85% by mass; and the solvent-type pigment dispersion composition contains 5 to 70% by mass of branched polyester (A) based on the solid content of the solvent-type pigment dispersion composition, 1 to 50% by mass of pigment dispersion resin (B) based on the solid content of the solvent-type pigment dispersion composition, and 5 to 70% by mass of pigment (C) based on the total mass of the solvent-type pigment dispersion composition. The solvent-type pigment dispersion composition as claimed in claim 1, wherein the branched polyester (A) further contains a chain extender (a4) as a constituent component. The solvent-type pigment dispersion composition of claim 1, wherein the acid value of the branched polyester (A) is less than 10 mgKOH/g, the number average molecular weight is 500 to 50,000, the hydroxyl value is 1 to 200 mgKOH/g, and the degree of branching is 2.5 to 7. The solvent-type pigment dispersion composition of claim 1, wherein the monoepoxy compound (a3) is a monoepoxy compound having a carbon number of 6 or more. A solvent-type coating composition obtained by mixing a plurality of (multiple colors) solvent-type pigment dispersion compositions such as any one of claims 1 to 4. A method for manufacturing a solvent-based paint composition, which comprises preparing a plurality of (multiple colors) solvent-based pigment dispersion compositions such as any one of claims 1 to 4, adding the plurality of solvent-based pigment dispersion compositions into the same paint tank for mixing to adjust the color. A method for producing a branched polyester, which is a method for producing a branched polyester (A), comprising the steps of sequentially performing step 1-1 and step 1-2: step 1-1: reacting a component comprising a polyol (a1) having a reactive functional group having three or more functions with a dicarboxylic acid and/or a dicarboxylic anhydride (a2) to form an intermediate product; step 1-2: reacting a component comprising the intermediate product with a monoepoxy compound (a3) having a long-chain alkyl group; the amount of component (a2) is 100 mol% or more based on the total amount of component (a1), and the amount of component (a3) is 100 mol% or more based on the total amount of component (a1). The method for producing branched polyester as claimed in claim 7, wherein the following steps are included after steps 1-1 and 1-2: Step 1-3: a step of further reacting the components containing the chain extender (a4). The method for producing branched polyester as claimed in claim 7, wherein the acid value of the aforementioned polyol (a1) having three or more reactive functional groups is less than 10 mgKOH/g. A method for producing a branched polyester, which is a method for producing a branched polyester (A), comprises the step of performing step 2-1: Step 2-1: a step of reacting components including a polyol (a1) having a reactive functional group having three or more functions, a dicarboxylic acid and/or a dicarboxylic anhydride (a2), and a monoepoxy compound (a3) having a long-chain alkyl group simultaneously. The method for producing branched polyester as claimed in claim 10, wherein the following steps are included after step 2-1: Step 2-2: a step of further reacting the components containing the chain extender (a4). The method for producing branched polyester as claimed in claim 10, wherein the acid value of the aforementioned polyol (a1) having reactive functional groups with three or more functional groups is less than 10 mgKOH/g. A method for producing a solvent-type pigment dispersion composition, which comprises mixing a branched polyester (A) obtained by the production method of any one of claims 7 to 12, a pigment dispersion resin (B), a pigment (C), and an organic solvent (D), and then dispersing the pigment using a medium to obtain the composition; the solid component of the solvent-type pigment dispersion composition is 20 to 85% by weight; and the solvent-type pigment dispersion composition contains 5 to 70% by weight of the branched polyester (A) based on the solid component of the solvent-type pigment dispersion composition, 1 to 50% by weight of the pigment dispersion resin (B) based on the solid component of the solvent-type pigment dispersion composition, and 5 to 70% by weight of the pigment (C) based on the total mass of the solvent-type pigment dispersion composition.