JPH059405A - Resin composition for pigment dispersion and preparation thereof - Google Patents

Abstract

PURPOSE:To provide a dispersant which, even when used in a small amount, can disperse pigments to give a low-thixotropy stable dispersion. CONSTITUTION:The title composition comprises (1) a reaction product obtained by reacting a polyamine having at least two primary and/or secondary amino groups with a polyisocyanate having at least two isocyanate groups in such a proportion that the amount of the primary and/or secondary amino groups is stoichiometrically at least equivalent to the isocyanate groups and (2) a resin containing an acidic functional group in an amount of 0.1-2.0 meq per g of the solid matter. The amounts of both components are such that the amount of the basic amino groups contained in component (1) is 0.1-3.0 equivalents based on the acidic functional groups of component (2).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pigment-dispersing resin composition used for blending pigments in the production of paints, inks, plastics and the like, and a method for producing the same.

[0002]

2. Description of the Related Art Since pigments generally have poor dispersibility, they are used by being dispersed in a pigment dispersion resin composition when blended into paints, inks or plastics. If the pigment has poor dispersion stability, the pigment aggregates and exhibits remarkable thixotropic properties. Then, in the paint prepared using the resin composition for pigment dispersion containing the pigment particles thus aggregated, various problems such as a decrease in gloss, a decrease in image clarity, a decrease in coloring power and color separation occur. In such a resin composition for dispersing a pigment, the performance of the pigment cannot be sufficiently exhibited.

For this reason, various improvements in pigment dispersion resin compositions have been proposed in the past.
No. 166318, No. 61-174939, No. 1-141968, No. 2-219.
866 publication. The present inventors have also provided a novel pigment-dispersing resin composition in, for example, JP-A-61-281161. This Japanese Patent Laid-Open No. 61-281
The resin composition for pigment dispersion according to Japanese Patent No. 161 is prepared by using a reaction product of a polyamine and a polyisocyanate as a dispersant, and is a useful composition in which the above problems are considerably solved.

[0004]

However, in this resin composition for dispersing pigments, when the vehicle resin of the paint to be prepared has a low molecular weight or when the amount of acidic functional groups such as carboxyl groups is small, dispersion is achieved. The effect of stability of may not be fully satisfied. In particular, recently there is a tendency for paints to become solid (high solidification) due to the demand for solvent removal.
In addition, there is a tendency for coating properties such as high weather resistance to be highly demanded, but it is necessary to use a low molecular weight low viscosity resin as a vehicle resin to support high solidification, and the amount of acidic functional groups. If the amount is large, the weather resistance and the like are deteriorated, so that it is necessary to use a vehicle resin having a small number of acidic functional groups, and it is difficult to cope with the use of such a vehicle resin.

In order to solve this problem, it has been studied to use a resin composition for dispersing pigments by blending a resin having a high molecular weight or a resin having a high acid value as a dispersant, but sufficient dispersion stability is obtained. In order to bring out the effect, it is necessary to increase the blending amount of this resin, and as a result, it becomes disadvantageous in achieving high solidity of the paint, and the physical properties of the paint film such as weather resistance of the paint deteriorate.

The present invention has been made in view of the above points, and a pigment having a low thixotropic property can be obtained by using a small amount with respect to a pigment without affecting physical properties of a coating such as high solidity of coating material and weather resistance. It is an object of the present invention to provide a pigment-dispersing resin composition capable of stably dispersing a pigment and a method for producing the same.

[0007]

The resin composition for pigment dispersion according to the present invention comprises a polyamine having at least two primary and / or secondary amino groups and a polyisocyanate having at least two isocyanate groups. A reaction product obtained by reacting a nato with a primary and / or secondary amino group to an isocyanate group in a stoichiometrically at least equal amount, and an acidic functional group having a solid content of 1 g. 0.1 to 2.0 milliequivalents of resin per 1 equivalent of acidic functional groups of the resin, the basic amine group contained in the reaction product of the polyamine and polyisocyanate is 0.1 to 0.1 equivalent. It is characterized by being 3.0 equivalents.

Further, in the method for producing a resin composition for pigment dispersion according to the present invention, an acidic functional group is added in an amount of 0.
In a resin containing 1 to 2.0 milliequivalents, a polyamine having at least two primary and / or secondary amino groups and a polyisocyanate having at least two isocyanate groups are added to form an isocyanate group. The primary and / or secondary amino groups are mixed so that they are stoichiometrically at least equal to each other and reacted, and a reaction formation of polyamine and polyisocyanate per 1 equivalent of the acidic functional group of the resin The basic amino group contained in the product is adjusted to 0.1 to 3.0 equivalents.

The present invention will be described in detail below. (Resin) The resin used in the present invention has a basic skeleton composed of an ester chain, a vinyl chain, an acrylic chain, an ether chain or the like, and a part of hydrogen atoms in the molecule is replaced with a halogen atom. You may have something. Among these, acrylic resins, polyester resins and alkyd resins, particularly acrylic resins and polyester resins are preferable. The number average molecular weight of this resin is 800 to 20.
000 (measured by gel permeation chromatography, converted to polystyrene) is preferable, and more preferably 1,000 to 10,000 in terms of number average molecular weight. If the molecular weight is less than 800, the effect of enhancing the dispersion stability of the pigment cannot be sufficiently obtained, and conversely, if the molecular weight exceeds 20,000, the viscosity of the pigment-dispersing resin composition increases, and the high solids of the coating composition Conversion becomes a disadvantage.

As this resin, a resin containing an acidic functional group in an amount of 0.1 to 2.0 milliequivalents per gram of resin solid content is used. The acidic functional group is composed of a carboxyl group, a sulfone group, a phosphoric acid group, etc., but a resin having a carboxyl group as an acidic functional group is mainly used.
When the content of the acidic functional group is less than 0.1 milliequivalent per gram, the effect of increasing the dispersion stability of the pigment cannot be sufficiently obtained, and the content of the acidic functional group is 2.
If it exceeds 0 meq, the physical properties of the coating film such as the weather resistance of the paint prepared using this pigment dispersion resin composition may deteriorate. Here, the acidic functional group (hereinafter, represented by a carboxyl group as a representative) may be arranged at random in the molecule of the resin as in ordinary coating resin,
Those in which three carboxyl groups are arranged only at the terminal of the resin molecule, particularly those in which one to three carboxyl groups are arranged at only one terminal of the resin molecule are preferable. It is advantageous for the carboxyl groups to be located essentially in one or two specific places.
In a resin containing a carboxyl group at random in the molecule, when it is attempted to contain a large amount of the reaction product of polyamine and polyisocyanate, the viscosity rises remarkably and the reaction product is evenly distributed in the resin. It cannot be present and may precipitate or become cloudy. On the other hand, a resin in which a carboxyl group is arranged at a specific position in the molecule has a polyamine and a resin which does not contain an acidic functional group such as a carboxyl group or a carboxyl group in the molecule at random. A large amount of reaction product with polyisocyanate can be contained, which is advantageous in this respect. Further, the resin in which the carboxyl group is arranged at a specific position in the molecule is more likely to take a dispersion stabilizing structure of the pigment due to solvation when adsorbed to the pigment than the resin which is randomly arranged. It is advantageous. Examples of such a resin include a monool having a general formula of Q-OH (wherein Q is an acrylic resin residue or a polyester resin residue) having a number average molecular weight of 800 to 10,000, and a cyclic acid anhydride of a carboxylic acid. There is something obtained by reacting with.

Next, various methods of synthesizing a resin suitable for use in the present invention will be illustrated. <Example 1: Acrylic resin> An acrylic monomer containing no carboxyl group is used as an initiator usually used in the synthesis of an acrylic resin, such as an azo-nitrile compound.
Polymerization is initiated by using 2-azo-bis-isobutyronitrile or t-butyl peroxide as a peroxide compound, and a compound having a carboxyl group such as mercaptoacetic acid or mercaptosuccinic acid is used as a chain transfer agent. As a result, a carboxyl group can be introduced at the terminal of the acrylic prepolymer.

When an acrylic resin is synthesized by polymerizing an acrylic monomer not containing a carboxyl group, an initiator containing a carboxyl group such as 4,4-
A carboxyl group can also be introduced at the terminal of the acrylic prepolymer by initiating the polymerization using azo-bis- (4-cyanopentanoic acid). Further, the carboxyl group can be introduced into the terminal of the acrylic prepolymer by polymerizing an acrylic monomer in which both a chain transfer agent containing a carboxyl group and an initiator containing a carboxyl group are used in combination.

Here, the above-mentioned acrylic monomer not containing a carboxyl group includes a neutral monomer and a functional group-containing monomer. Examples of the neutral monomer include ethylene, propylene, butadiene, isoprene, chloroprene, vinyl chloride, vinyl acetate, methyl vinyl ether, acrylic acid ester (eg, methyl, ethyl, butyl ester), methacrylic acid ester (eg, methyl, ethyl, butyl ester). Etc.), nitrile derivatives (eg acrylonitrile, methacrylonitrile etc.), styrene, styrene derivatives (eg α-methylstyrene etc.)
And so on. Further, as the functional group-containing monomer,
Amide group-containing monomers include acrylamide and methacrylamide, and alkoxy group-containing monomers such as N-
Methoxymethylol acrylamide, N-butoxy methylol acrylamide and the like are used as hydroxyl group-containing monomers such as 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxyethyl methacrylate and 2-hydroxy. Examples include propyl methacrylate and N-methylol acrylamide.

When the acrylic prepolymer (acrylic resin) is polymerized as described above, a known solution polymerization method is used to charge the whole amount, an initiator dropping method, or a monomer dropping method to obtain a temperature not lower than the decomposition temperature of the initiator, usually. Is 70-1
It can be carried out by reacting at a reaction temperature of 70 ° C. for 1 to 8 hours. <Example 2: Acrylic resin> A neutral acrylic monomer is polymerized using a chain transfer agent having a hydroxyl group such as mercaptoethanol to prepare an acrylic monool having a hydroxyl group at one end, which is further reacted with an acid anhydride. By doing so, a carboxyl group can be introduced into the terminal of the acrylic prepolymer.

As the acid anhydride, phthalic anhydride, tetrahydrophthalic anhydride, tetrachlorophthalic anhydride,
Succinic anhydride, maleic anhydride, trimellitic anhydride,
Examples thereof include cyclic anhydrides of carboxylic acids such as pyromellitic dianhydride and benzophenone tetracarboxylic dianhydride. <Example 3: Polyester Resin> A lactone having 6 to 8 carbon atoms is added to a monohydric alcohol such as butanol or lauryl alcohol to carry out a ring-opening polymerization reaction to prepare a polyester monool having a hydroxyl group at one end. The reaction is carried out in a nitrogen atmosphere at a temperature of 120 to 180 ° C., and an organometallic catalyst such as tetrabutyl titanate or dibutyltin laurate can be used as a catalyst. By reacting the obtained polyester monool with an acid anhydride, a polyester resin having a carboxyl group at the terminal can be obtained. Examples of the lactone having 6 to 8 carbon atoms include ε-caprolactam, γ-butyrolactone, δ-valerolactone and the like. As the acid anhydride, those listed above can be mentioned.

<Example 4: Polyester resin> A hydroxycarboxylic acid or monocarboxylic acid is reacted with a lactone having 6 to 8 carbon atoms to obtain a polyester resin having a carboxyl group at the terminal. The reaction is carried out in a nitrogen atmosphere at a temperature of 120 to 180 ° C., and an organometallic catalyst such as tetrabutyl titanate or dibutyltin laurate can be used as a catalyst. Examples of the hydroxycarboxylic acid include hydroxyacetic acid, hydroxystearic acid and dimethylolpropionic acid, and examples of the monocarboxylic acid include acetic acid, benzoic acid, octylic acid, lauric acid and stearic acid. Examples of lactones and acid anhydrides include those listed above.

<Example 5: Polyester resin> A polyester resin having a carboxyl group at a terminal can be obtained by subjecting a hydroxycarboxylic acid such as 12-hydroxystearic acid to a dehydration polycondensation reaction. The reaction is carried out using a known esterification catalyst such as phosphoric acid, p-toluenesulfonic acid, tetra-n-butyl titanate, dibutyltin oxide, etc., and removing the produced water out of the system at a temperature of 120 to 200 ° C. You can do it.

<Example 6: Polyester Resin> Using a monocarboxylic acid as an initiator, a monoepoxy compound and an acid anhydride are reacted at 140 to 160 ° C. in a nitrogen atmosphere. As the reaction catalyst, tetra-n-butyl titanate, dibutyltin oxide, dimethylbenzylamine or the like can be used. As the monocarboxylic acid, those listed above can be used, and as the monoepoxy compound, propylene oxide, lauric acid glycidyl ester, stearic acid glycidyl ester, versatic acid glycidyl ester and the like can be used. In this reaction, the monocarboxylic acid first opens the epoxy group to form a secondary hydroxyl group, and the acid anhydride reacts with this to form a carboxyl group. The monoepoxy compound further reacts with the carboxyl group to generate an ester bond and a secondary hydroxyl group, and the acid anhydride reacts with the secondary hydroxyl group to generate a carboxyl group. By repeating this, the polyester main chain extends. Then, when the end of the reaction is terminated by the reaction with an acid anhydride, a polyester resin having a carboxyl group at one end can be obtained.

With the same reaction mechanism, a monoepoxy compound and an acid anhydride are reacted at 140 to 160 ° C. in a nitrogen atmosphere with a monohydric alcohol as an initiator to give a polyester resin having a carboxyl group at one end. Obtainable. In addition to the resins obtained as in the above examples, other acrylic resins, polyester resins, alkyd resins, amino resins typified by melamine-formaldehyde resins, resins commonly used in the paint and ink industries. Can also be mixed and used together.

(Polyamine) As the polyamine having at least two primary and / or secondary amino groups used in the present invention, ethylenediamine, 1,3-propylenediamine, hexamethylenediamine, diethylenetriamine, dipropylenetriamine, Polyalkylenepolyamines such as triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, polyethyleneimine, alicyclic polyamines such as N, N-bis (γ-aminopropyl) piperazine, N- (β-aminoethyl) piperazine, Examples thereof include aromatic polyamines such as bisaminopyridine, xylylenediamine, metaphenylenediamine, and 4,4′-diaminodiphenylmethane. Among these, polyamines having at least three primary and / or secondary amino groups and polyamines having at least two primary and / or secondary amino groups and at least one tertiary amino group are preferably used. You can In addition, it is advantageous to increase the density of functional groups in the resulting dispersant in order to improve the dispersibility in the pigment. Therefore, it is preferable that the amine equivalent (molecular weight / total number of 1,2,3,3 amino groups) of these polyamines is low, and polyamines of 100 or less, and more preferably 50 or less are advantageous. Examples of this suitable polyamine include diethylenetriamine, triethylenetetramine,
Polyethyleneimine industrially obtained by cationic polymerization of tetraethylenepentamine, pentaethylenehexamine, ethyleneimine, that is, polyalkylenepolyamine such as polyethyleneimine represented by the general formula such as formula (A), N, N-bis Examples thereof include alicyclic polyamines such as (γ-aminopropyl) piperazine and N- (β-aminoethyl) piperazine, and aromatic polyamines such as bisaminopyridine.

[0021]

[Chemical 1]

(Polyisocyanate) As the polyisocyanate having at least two isocyanate groups used in the present invention, tolylene diisocyanate (TDI), 4,4'-diphenylmethane diisocyanate (MDI), Xylylene diisocyanate (XD
I), hexamethylene diisocyanate, hydrogenated MD
Examples thereof include diisocyanate compounds such as I, hydrogenated TDI, hydrogenated XDI, and inphorone diisocyanate, but more preferably polyfunctional polyisocyanates are advantageous. Examples of such a polyisocyanate include compounds represented by formulas (1) to (4) obtained by reacting a polyol with diisocyanate,
A compound represented by the formula (5) obtained from the diisocyanate by a Biuret reaction, a compound represented by the formula (6) to the formula (8) obtained by ring formation of the diisocyanate, or a compound represented by the formula (9) ) And a compound represented by the formula (10).

[0023]

[Chemical 2]

[0024]

[Chemical 3]

[0025]

[Chemical 4]

[0026]

[Chemical 5]

[0027]

[Chemical 6]

The trade names of commercial products containing these compounds as main components are as follows. That is, those containing the compound of formula (1) as the main component are "Coronate HL" manufactured by Nippon Polyurethane Industry Co., Ltd., and those containing the compound of formula (2) as the main component are "Sumijour L" manufactured by Sumitomo Bayer Urethane Co., Ltd. , "Takenate D-1 manufactured by Takeda Pharmaceutical Co., Ltd."
10N ", those containing the compound of formula (4) as the main component are manufactured by Takeda Pharmaceutical Co., Ltd.," Takenate D-120N ", those containing the compound of formula (5) as the main component are manufactured by Takeda Pharmaceutical Co., Ltd. "Takenate D-165N" and "Takenate D
-165N-90CX "," Sumijour N "manufactured by Sumitomo Bayer Urethane Co., Ltd., and those containing a compound of formula (6) as a main component are" Coronate EH "manufactured by Nippon Polyurethane Industry Co., Ltd. and a compound of formula (7). The main component is "Desmodur IL" manufactured by Bayer AG, the main component is a compound of Formula (8) "Desmodur HL" manufactured by Bayer AG, and the compound of Formula (9) is a main component. "Desmodur R" manufactured by Bayer AG, and "Millionate MR" manufactured by Nippon Polyurethane Industry Co., Ltd. are mainly composed of the compound of the formula (10). These products are not pure, but mainly consist of compounds having the structures shown by the respective formulas, and are mixtures with compounds having structures similar to those structures, but all have an average functionality of 2.5 to 6 It has a number of groups (the number of isocyanate groups per average molecular weight).

(Organic Solvent) The pigment dispersion resin composition according to the present invention may contain an organic solvent, if necessary. The solvent that can be used is not particularly limited as long as it is commonly used in the paint and ink industries. For example, toluene, xylene, "Solvesso 100" and "Solvesso 1" manufactured by Esso Standard Co., Ltd.
Hydrocarbon solvent such as 50 ", ester solvent such as ethyl acetate and butyl acetate, ketone solvent such as methyl ethyl ketone and methyl isobutyl ketone, ether solvent such as ethylene glycol monoethyl ether and ethylene glycol mononormal butyl ether, n -Butanol,
Examples thereof include alcohol solvents such as isobutanol.

These solvents can be used alone or in combination of two or more, and the resin composition for pigment dispersion according to the present invention can be produced by dissolving the above resin in these solvents. It can be done easily. The blending amount of the solvent can be arbitrarily set as needed, but it is common to adjust the blending amount of the solvent so that the solid content in the resin composition for pigment dispersion is 5 to 80% by weight. is there. In the production of the pigment dispersion resin composition, it may be more advantageous in the dispersibility of the pigment that the proportion of the solvent is large, the solvent in the pigment dispersion resin composition, after producing the pigment dispersion resin composition, It can also be adjusted by removing it by a technique such as vacuum concentration so that it can be easily handled.

(Blending ratio of polyamine and polyisocyanate) In the present invention, at least two polyamines having a primary and / or secondary amino group and at least 2
The blending ratio with the polyisocyanate having an isocyanate group is preferably set so that the primary and / or secondary amino groups are at least stoichiometrically equivalent to the isocyanate group, In general, it is preferable to adjust the compounding ratio so that the amino group is equal to or more than the equivalent amount of the isocyanate group.

When a polyamine having only primary and / or secondary amino groups is used and blended so that the amino groups are in excess of the isocyanate groups, the primary and / or
Alternatively, it is preferable to use a polyamine containing at least three secondary amino groups, and mix such that at least two amino groups among them react with the isocyanate group.

Even when using a polyamine having a tertiary amino group in addition to the primary and / or secondary amino group, it is necessary that at least two of the primary and / or secondary amino groups react with the isocyanate group. It is preferable to mix them. More preferably, a polyamine containing at least 4 primary and / or secondary amino groups is used, and a polyisocyanate having an average number of functional groups (ie, isocyanate functional groups / average molecular weight) of 2.5 to 6 is used. The polyamine is preferably blended so that at least three amino groups react with the isocyanate groups of the polyisocyanate. In either case, the total amount of the primary amino group, secondary amino group, and tertiary amino group before the reaction is preferably in the range of 1.05 to 5 times the equivalent weight of the isocyanate group.

(Blending Ratio of Polyamine and Polyisocyanate to Resin) In the present invention, the blending ratio of the polyamine and polyisocyanate to the above resin is such that the polyamine and polyisocyanate are equivalent to 1 equivalent of the acidic functional group of the resin. The basic amino group contained in the reaction product with, that is, the unreacted amino group is stoichiometrically adjusted to 0.1 to 3.0 equivalents, and more preferably 0.2 to 2.0 equivalents. It is something to set. The manifestation mechanism of pigment dispersion by the resin composition for pigment dispersion according to the present invention is not clear, but polyurea produced by the reaction of polyamine and polyisocyanate and a resin having an acidic functional group form a huge complex. However, it is considered that this is adsorbed to the pigment and contributes to stabilizing the dispersion of the pigment. Therefore, if the reaction product of polyamine and polyisocyanate contains less than 0.1 equivalent of basic amino groups per equivalent of acidic functional groups of the resin, the formation of this complex will be insufficient. The effect of enhancing the dispersion stability of the pigment cannot be sufficiently obtained. On the contrary, when the basic amino group contained in the reaction product of polyamine and polyisocyanate exceeds 3.0 equivalents per equivalent of acidic functional groups of the resin, the presence of basic functional groups becomes excessive. There is a possibility that the physical properties of the coating film such as hardness and weather resistance may be adversely affected.

The compounding ratio of the polyamine and polyisocyanate to the resin is such that the weight ratio of the total amount of polyamine and polyisocyanate to the resin is 99: 1 to 7.
The range is preferably 0:30, and more preferably 97: 3 to 80:20. If the total amount of the polyamine and the polyisocyanate is too large, the viscosity of the resin composition for pigment dispersion may be significantly increased, which may cause gelation or insolubilization, which is not preferable, and too small a dispersion of the pigment. It is not preferable because the property becomes insufficient.

(Production of Pigment Dispersion Resin Composition) The pigment dispersion resin composition according to the present invention can be produced as follows. That is, first, a resin containing an acidic functional group, a polyamine, and an organic solvent, if necessary, are mixed, and a polyisocyanate is further added to react the polyamine and the polyisocyanate to disperse the pigment according to the present invention. A resin composition can be obtained. At this time, it is preferable to add the polyisocyanate while stirring.
Of course, the polyisocyanate may be mixed first, and then the polyamine may be added and reacted. If necessary, in addition to the resin having the acidic functional group,
Other resins, whether or not they have acidic functional groups
For example, a resin that is usually used in the paint or ink industry, such as an acrylic resin, a polyester resin, an alkyd resin, or an amino resin typified by melamine-formaldehyde resin, is mixed and allowed to react with a polyamine and a polyisocyanate. You can also The reaction can be carried out at room temperature, but if necessary, the reaction may be carried out by heating. The reaction time is usually within 30 minutes.

(Use of Pigment Dispersion Resin Composition) The pigment dispersion resin composition according to the present invention produced as described above is
It is used as a pigment dispersant for preparing a pigment dispersion composition by dispersing a pigment, for example, by adding a pigment and a resin composition according to the present invention, if necessary further adding an organic solvent and a vehicle resin. A pigment dispersion composition can be prepared by mixing with stirring and dispersing this using a disperser. As the disperser, a sand grind mill, a ball mill, a roll mill, an attritor, a dissolver and the like, which are generally used in the paint industry and the ink industry, can be used. As the vehicle resin, resins usually used in the paint and ink industries, such as alkyd resin, polyester resin, acrylic resin, polyamide resin, chlorinated polyolefin resin, polyvinyl acetate resin and the like can be used. The mixing ratio of the pigment and the pigment-dispersing resin composition according to the present invention varies depending on the type of the pigment, but the weight ratio of the solid content of the pigment-dispersing resin composition to the pigment is in the range of 99: 1 to 70:30. Generally preferred.

As the pigment, various inorganic pigments or organic pigments usually used in the paint industry or the printing ink industry can be used. Examples of inorganic pigments include zinc white, titanium oxide, antimony white, red iron oxide, yellow iron oxide, transparent iron oxide, red tan, cadmium yellow, zinc sulfide, lithopone, barium sulfate, lead sulfate, barium carbonate,
Lead white, alumina white, carbon black, etc., and examples of organic pigments are azo, polycondensed azo, metal complex azo, benzimidazolone, phthalocyanine blue, phthalocyanine green, thioindigo, anthraquinone. System, flavanthlon system,
Indanthrene, anthrapyrimidine, pyranthrone, isoindolinone, perylene, perinone,
Such as quinacridone.

[0039]

EXAMPLES Next, the present invention will be specifically illustrated by examples. Example 1 A solvent in column (a) of Table 1 was charged into a reaction vessel equipped with a cooling tube, a stirrer, a nitrogen introducing tube, and a dropping funnel, and heated to 130 ° C. under a nitrogen stream. Next, using a dropping funnel, (a) in Table 1
The monomer in the column was dropped at a constant rate over 3 hours, and at the same time, the initiator solution and the chain transfer agent solution in the column (a) of Table 1 were mixed and dropped at a constant rate in another dropping funnel. Thirty minutes after the dropping was completed, the post-addition solution in the column (a) of Table 1 was added dropwise at a constant rate over 30 minutes to complete the polymerization. After 1 hour, the solution was cooled and taken out from the reaction solution to obtain a resin solution (a) having an acidic functional group (carboxyl group) at the molecular end and a solid content of about 50%.

The solid content of this resin solution, the amount of acidic functional groups in the resin solid content, and the number average molecular weight were measured. The solid content was measured by heating the resin solution at 110 ° C. for 3 hours and drying, and the results are shown in Table 2 in% by weight. The amount of acidic functional groups in the resin solid content was measured by titrating with potassium hydroxide using phenolphthalein as an indicator, and the results are shown in Table 2 with acid value (mgKOH /
It is shown as g). The number average molecular weight was measured by gel permeation chromatography.

Next, to the resin solution (a) prepared as described above, methyl isobutyl ketone as a solvent and tetraethylene pentamine as a polyamine were added in the amounts shown in Table 3 and stirred. "Takenate D-165N" manufactured by Takeda Pharmaceutical Co., Ltd. as polyisocyanate while being stirred.
-90CX "(amine equivalent 200) was added in the addition amount shown in Table 3, and the mixture was further stirred as it was to obtain a resin composition for pigment dispersion (a-1) (a-2) (a-3).

The solid content of the resin composition for pigment dispersion thus obtained was measured by heating at 110 ° C. for 3 hours and drying, and the state of the resin composition for pigment dispersion was observed. Further, the amount (B) of amino groups contained in the reaction product of polyamine and polyisocyanate and the amount (A) of carboxyl groups in the solid content of the resin composition for pigment dispersion were measured, and the ratio of the two was calculated as an equivalent ratio. (B / A). Here, the amount of amino groups was measured by dissolving the pigment-dispersed resin composition in acetic acid and then titrating with perchloric acid.
The end point was determined by potentiometric titration. These results are the third
Shown in the table.

Example 2 In the same manner as in Example 1, the composition in the column (b) of Table 1 was changed to
A resin solution (b) having an acidic functional group (carboxyl group) at the molecular end and having a solid content of about 50% was obtained. Using this resin solution (b), in the same manner as in Example 1, a polyamine or polyisocyanate was added and reacted in the formulation shown in Table 3 to give a resin composition for pigment dispersion (b-1) (b). −
2) (b-3) was obtained.

Example 3 A solid content having an acidic functional group (carboxyl group) at the molecular end was prepared in the same manner as in Example 1 except that the heating temperature was 100 ° C., in the composition of column (c) of Table 1. A resin solution (c) of about 50% was obtained. Using this resin solution (c), in the same manner as in Example 1, a polyamine or polyisocyanate was added according to the formulation shown in Table 3 and the mixture was reacted to give a pigment dispersion resin composition (c-1) (c). -2) (c-3) was obtained.

Example 4 In the same manner as in Example 1, except that the composition in the column (d) of Table 1 was changed to
A resin solution (d) having a solid content of about 50% and having an acidic functional group (carboxyl group) at random in the molecule was obtained. Using this resin solution (d), in the same manner as in Example 1, a polyamine or polyisocyanate was added and reacted in the formulation shown in Table 3 to obtain a pigment dispersion resin composition (d-1).
(D-2) and (d-3) were obtained.

Example 5 In the same manner as in Example 1, the composition in the column (e) of Table 1 was changed to
A resin solution (e) having a solid content of about 50% and having an acidic functional group (carboxyl group) at random in the molecule was obtained. Using this resin solution (e), a polyamine or polyisocyanate having the composition shown in Table 3 was added and reacted in the same manner as in Example 1 to obtain a pigment dispersion resin composition (e-1).
(E-2) and (e-3) were obtained.

Among Examples 1 to 5 above, in Examples 4 and 5 in which the resin having an acidic functional group at random in the molecule was used, the resin composition for pigment dispersion (d) in Example 4 was used. -2) (d-3) or a resin composition (e-2) (e-3) for pigment dispersion in Example 5, which has a high viscosity and becomes a paste or gel. Therefore, it is confirmed that it is preferable to use a resin having an acidic functional group at the molecular end as in Examples 1 to 3 to obtain a stable resin composition for pigment dispersion.

Comparative Example 1 The resin solution (c) obtained in Example 3 was used, and the reaction was then performed in the same manner as in Example 1 with or without addition of polyamine or polyisocyanate in the formulation shown in Table 4. Thereby, a resin composition for pigment dispersion (c-4) (c-5) was obtained. Comparative Example 2 In the same manner as in Example 1, a resin solution (f) was obtained with the composition shown in the column (f) of Table 1. Using this resin solution (f), in the same manner as in Example 1, a polyamine or polyisocyanate was added according to the formulation shown in Table 4 and reacted to give a pigment dispersion resin composition (f-1) (f -2) (f-3) was obtained. (F-2) and (f-3) had extremely high viscosities and could not be used as dispersants.

[0049]

[Table 1]

[0050]

[Table 2]

[0051]

[Table 3]

[0052]

[Table 4]

[0053]

[Table 5]

[0054]

[Table 6]

[0055]

[Table 7]

(Preparation of paint) 50 parts by weight of the resin solution (f), 30 parts by weight of xylene, 20 parts by weight of "Shinkasha Red Y" manufactured by Ciba-Geigy Co., Ltd. as a pigment, and a resin composition (a- 3) (b-3) (c-1)
(C-2) (c-3) (d-1) (e-1) and (c-
4) (c-5) (f-1) was added in an amount of 0 to 30% by weight (converted to a solid content) to the pigment, and the mixture was dispersed by stirring for 1 hour with a paint shaker. After dispersing the pigment in this way, 20 parts by weight of the resin solution (f) and 20 parts by weight of melamine formaldehyde resin varnish "Uban 20N-60 Varnish" manufactured by Mitsui Toatsu Chemicals, Inc. were added, and 20 parts of Ford cup # 4 was added. The paint was prepared by adding thinner in seconds.

This paint was spray coated on a tin plate and then baked at 130 ° C. for 20 minutes to obtain a coating film. The relationship between the 20 ° specular gloss of the coating film thus obtained and the addition amount of the pigment-dispersing resin composition is shown in FIG. Pigment dispersion resin composition (a-3) (b-3) (c-1) (c) obtained in each example.
-2) By adding (c-3) (d-1) (e-1), it is confirmed that the gloss of the coating film can be increased and the dispersibility of the pigment is improved. On the contrary,
In (c-4) and (f-1), the gloss of the coating film could not be increased, and the dispersibility of the pigment was not improved. The hardness of the coating film obtained as described above was measured by pencil hardness. The resin composition for pigment dispersion (a) obtained in each example
-3) (b-3) (c-1) (c-2) (c-3) (d
-1) (e-1) was compounded with "F" regardless of the amount used, which was the same as when not compounded.
On the other hand, the use of the pigment-dispersing resin composition (c-5) can enhance the gloss of the coating film, but since it contains a large amount of amino groups, it has a solid content of 10 relative to the pigment.
The hardness of the coating film decreased from "F" to "B" in terms of pencil hardness when used in an amount of more than 10% by weight.

Example 6 74 parts by weight of n-butanol, 2000 parts by weight of ε-caprolactone “Placcel M” manufactured by Daicel Chemical Industries, Ltd., and 4 parts by weight of dibutyltin oxide were charged in a reaction vessel and reacted at 150 ° C. in a nitrogen atmosphere. Then, a polyester resin having a hydroxyl group at the end is prepared, and the solid content is 50
A resin solution (g) was obtained by dissolving with xylene in wt%.

100 parts by weight of this polyester resin solution (g) was reacted with 3.6 parts by weight of phthalic anhydride at 120 ° C. for 2 hours to obtain a resin having an acidic functional group (carboxyl group) at the molecular end. Then, 4.0 parts by weight of pentaethylenehexamine as a polyamine and "Takenate D-165N-90CX" (amine equivalent 200) manufactured by Takeda Pharmaceutical Co., Ltd. as a polyisocyanate 1
2.0 parts by weight was added and the mixture was reacted with stirring, and the solid content was adjusted to 50% with xylene to obtain a resin composition (g-1) for pigment dispersion.

The above polyester resin solution (g) 10
0 parts by weight and 7.3 parts by weight of trimellitic anhydride at 120 ° C
Was reacted for 2 hours to obtain a resin having an acidic functional group (carboxyl group) at the molecular end. Then, 4.0 parts by weight of pentaethylenehexamine as a polyamine, and “2.0% Takenate D-165N-90CX” manufactured by Takeda Pharmaceutical Co., Ltd. as a polyisocyanate are used.
Add parts by weight and react with stirring. Solid content is 50% with xylene.
The resin composition for pigment dispersion (g-2) was obtained.

Example 7 A 50% xylene 50% solution of "Plaxel 220L" manufactured by Daicel Chemical Industries, Ltd. was used as a polyester resin having hydroxyl groups at both ends of the molecule, and phthalic anhydride 7 was added to 100 parts by weight of the solid content of the resin. Add 4 parts by weight, 120 ° C
The resin having an acidic functional group (carboxyl group) at both ends of the molecule was obtained by reacting for 2 hours. Pentaethylene hexamine 4.
"Takenate D-165N-90CX" manufactured by Takeda Pharmaceutical Co., Ltd. as a polyisocyanate at 0 parts by weight.
2.0 parts by weight was added and the reaction was carried out with stirring, and the solid content was adjusted to 50% with xylene to obtain a resin composition (h) for pigment dispersion.

(Preparation of Pigment Dispersion Composition) Pigment "Chromo Fine Magenta 6880" manufactured by Dainichiseika Co., Ltd. 20
The resin composition for pigment dispersion (g-1) (g-2) is added in parts by weight.
1 to 20 parts by weight of (h) was added to each, and xylene was added to 100 parts by weight, and the mixture was dispersed for 1 hour with a paint shaker to obtain a paste-like pigment dispersion composition.

The viscosity of this pigment dispersion composition was measured using a cone-plate type rotational viscometer (E-type viscometer manufactured by Tokyo Keiki Co., Ltd.) under the conditions of a shear rate of 19.2 / sec and a temperature of 20 ° C. The relationship between the addition amount of the pigment dispersion resin composition and the viscosity is shown in FIG. It is confirmed that the resin compositions for pigment dispersion obtained in Examples 6 and 7 can reduce the thixotropy of the pigment dispersion composition and reduce the viscosity with a small addition amount, and excellent flowability can be obtained. Particularly, the pigment dispersion resin compositions (g-1) and (g-2) were excellent.

A paste-like pigment dispersion composition was obtained in the same manner using the resin solution (g) as it was. The viscosity of this product was measured in the same manner, and the relationship between the addition amount and the viscosity is shown in FIG. It is confirmed that even if the resin solution (g) is used as it is, there is no effect of reducing the thixotropy of the pigment dispersion composition.

[0065]

As described above, the pigment-dispersing resin composition according to the present invention can stably disperse the pigment with a small thixotropic property even when used in a small amount, and also makes the coating high solid and weather resistant. It does not affect the physical properties of the coating film such as properties.

[Brief description of drawings]

FIG. 1 is a graph showing the relationship between the amount of a pigment dispersion resin composition added and the gloss of a coating film.

FIG. 2 is a graph showing the relationship between the addition amount of the pigment dispersion resin composition and the viscosity of the pigment dispersion composition.

Continuation of the front page (51) Int.Cl. ⁵ Identification number Office reference number FI technical display location C09C 3/10 PCE B 6904-4J C09D 175/00 PHP 8620-4J

Claims (5)

[Claims] 1. A polyamine having at least two primary and / or secondary amino groups and a polyisocyanate having at least two isocyanate groups are primary and / or secondary with respect to the isocyanate groups. Of the reaction product obtained by reacting the amino groups of at least stoichiometrically to each other, and a resin containing 0.1 to 2.0 milliequivalents of acidic functional groups per gram of solid content. A resin composition for pigment dispersion, wherein the basic amino group contained in the reaction product of the polyamine and polyisocyanate is 0.1 to 3.0 equivalents per equivalent of the acidic functional group of the resin. object. 2. The resin composition for pigment dispersion according to claim 1, wherein the resin is selected from acrylic resins, polyester resins and alkyd resins, and has a number average molecular weight of 800 to 20,000. 3. The pigment-dispersing resin composition according to claim 1, wherein the resin has 1 to 3 carboxyl groups as acidic functional groups at the terminals of the molecule. 4. The resin composition for pigment dispersion according to claim 1, wherein the resin has 1 to 3 carboxyl groups as acidic functional groups at one end of the molecule. 5. The acidic functional group is added in an amount of 0.
In a resin containing 1 to 2.0 equivalents, a polyamine having at least two primary and / or secondary amino groups and a polyisocyanate having at least two isocyanate groups are used as isocyanate groups. On the other hand, a reaction product of a polyamine and a polyisocyanate per 1 equivalent of an acidic functional group of a resin is prepared by reacting primary and / or secondary amino groups in stoichiometric proportions Is adjusted so that the basic amino group contained in is 0.1 to 3.0 equivalents.