JPH0977990A - Pigment dispersant and pigment composition containing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a pigment dispersant which can disperse a pigment well and can be produced industrially advantageously and a pigment compsn. contg. the same. SOLUTION: This dispersant is obtd. by reacting an acrylic polymer having acid chloride groups with an org. colorant and/or a heterocyclic compd. having a prim or sec-amino group.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dispersant for pigment particles, and more particularly to a pigment dispersant for improving the suitability for use of printing inks and paints, and a pigment composition using the same.

[0002]

2. Description of the Related Art Generally, in various coatings or ink compositions, practically useful pigments exhibiting a clear color tone and high tinting strength are composed of fine particles. However, it is difficult to obtain a stable dispersion of fine particles of pigment, and it is known that the dispersion state of the particles causes various problems that seriously affect the manufacturing operation and the value of the obtained product. . Particularly in water, most pigments have extremely poor suitability for aqueous vehicles such as pigment dispersibility as compared with non-aqueous vehicles, so it is not possible to obtain a stable dispersion composed of finer particles than non-aqueous. More difficult. Dispersions containing pigments consisting of fine particles often exhibit high viscosities, causing difficulties in removing and shipping the dispersion from the disperser. In some cases, the dispersion may gel during storage and become unusable. Alternatively, when different kinds of pigments are mixed and used, a phenomenon such as color separation or sedimentation due to aggregation of the pigments may cause color unevenness or a marked decrease in coloring power in a color-developed product. Furthermore, in the case of such an unstable dispersion, the surface state of the coating film of the color-developed product is likely to be impaired, and, for example, lowering of gloss and poor leveling may occur.

Many proposals have been made so far in order to solve the above various problems. The contents can be roughly classified into the following three categories according to the technical method. 1. As is found in USP 3370971 and USP 2965511, pigment particles are coated with a colorless compound such as silicon oxide, aluminum oxide and tertiary butyl benzoic acid. 2. As represented by Japanese Examined Patent Publication No. 41-2466 and USP 2855403, it is obtained by using an organic pigment as a base skeleton and introducing a substituent such as a sulfone group, a sulfonamide group, an aminomethyl group and a phthalimidomethyl group into a side chain. It is a method of mixing the compound. 3. This is a method of mixing a polymer dispersant represented by JP-B-57-25251 and JP-A-61-285266.

In the case of the above 2, compared with the case of 1, the effect regarding the non-aggregation property of the pigment in the non-aqueous vehicle, the crystal stability, etc. is remarkably large, and a sufficient effect can be obtained even by a relatively simple mixing method. Often obtained. However, the effect of each compound is greatly influenced by the composition of the vehicle used, and no compound having a wide range of versatility effective for all vehicles has been found. In the case of 3 above, it is a method that is relatively versatile and has little influence of the vehicle composition, but since the interaction between the polymer dispersant and the pigment particles is weak, a sufficient effect can be obtained in terms of pigment dispersion stability. Often not.

On the other hand, as a polymer type dispersant in which an organic dye and a polymer are bonded, a non-aqueous type dispersant is disclosed in JP-A-4-139262
JP-A-6-65521 and JP-A-7-41689 disclose water-based ones. It is considered that since the interaction between the organic dye contained in the polymer dispersant and the pigment particles becomes strong, the adsorption of the polymer dispersant to the pigment particles is promoted and the dispersibility is improved. However,
The polymer dispersant described in the publication is one that binds an organic dye and a polymer by a reaction between a carboxyl group or a sulfonic acid group and a hydroxyl group or an amino group,
Considering the reactivity of each functional group and the solubility of the organic dye, the reaction rate between the polymer and the organic dye is poor, and it cannot be said to be an industrially advantageous method.

[0006]

DISCLOSURE OF THE INVENTION The present invention improves the above-mentioned various drawbacks, can disperse a pigment well in both aqueous and non-aqueous manner, and can be produced industrially advantageously, and a pigment dispersant. A pigment composition using the same is provided.

[0007]

[Means for Solving the Problems] That is, the first invention relates to an acrylic polymer having an acid chloride group, and a first invention.
A pigment dispersant obtained by reacting an organic dye having a primary amino group or a secondary amino group and / or a heterocycle, wherein the second invention is a pigment containing the pigment and the pigment dispersant of the first invention. It is a composition.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below.
Acrylic polymer having an acid chloride group used in the present invention, for example, a monomer having a radical polymerizable unsaturated bond such as methacryloyl chloride and an acid chloride group, and other radical polymerizable unsaturated bond. The method of copolymerizing with a monomer having, or after synthesizing the polymer using the α, β-ethylenically unsaturated carboxylic acid-containing monomer, thionyl chloride, phosphorus trichloride or oxalyl dichloride in the polymer is added. Obtained by the method of reacting with a carboxylic acid.

In the present invention, the acrylic polymer is basically a monomer having a radical polymerizable unsaturated bond as long as it is dissolved in a solvent of a pigment dispersion system after introducing an organic dye or the like. Is a resin having a weight average molecular weight of 3,000 to 200,000 and an acid value of 1 to 200. Examples of the monomer having a radical-polymerizable unsaturated bond include (meth) acrylic acid, crotonic acid, maleic acid, fumaric acid, citraconic acid, itaconic acid, and other α, β-ethylenically unsaturated carboxylic acids, and N. , N-dimethylaminoethyl (meth) acrylate, N, N-dimethylaminopropyl (meth) acrylate, N, N-dimethylaminobutyl (meth) acrylate, N, N-diethylaminoethyl (meth) acrylate, N, N- Diethylaminopropyl (meth) acrylate, N-ethylaminoethyl (meth) acrylate, N-propylaminoamino (meth) acrylate, N-butylaminoethyl (meth) acrylate, (meth) acrylamide, N, N-
Dimethylaminoethyl (meth) acrylamide, N, N
-Dimethylaminopropyl (meth) acrylamide,
N, N-dimethylaminobutyl (meth) acrylamide, N, N-diethylaminoethyl (meth) acrylamide, N, N-diethylaminopropyl (meth) acrylamide, N-ethylaminoethyl (meth) acrylamide, N-propylaminoethyl ( Α, β-ethylenically unsaturated nitrogen-containing monomers such as (meth) acrylamide and N-butylaminoethyl (meth) acrylamide, and further vinylpyrrolidones, vinylpyridines, vinylimidazoles, vinylcarbazoles, vinylquinolines And unsaturated monomers having a nitrogen-containing heterocycle such as vinylpiperidines. As the monomer having a radical-polymerizable unsaturated bond other than the above, (meth) acrylic acid alkyl esters, (meth) acrylic acid hydroxyalkyl esters, vinyl aromatic compounds, and the like can be used. ) Examples of alkyl acrylates include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, hexyl (meth) acrylate, and (meth) acrylic acid. Examples include 2-ethylhexyl and lauryl (meth) acrylate. Moreover, 2-hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, etc. are mentioned as an example of (meth) acrylic acid hydroxyalkyl ester. Further, examples of the vinyl aromatic compound include styrene, α-methylstyrene, styrenesulfonic acid, vinyltoluene, p-chlorostyrene and the like. In addition, acrylonitrile, vinyl acetate, etc. can be used.

The pigment dispersant of the present invention can be applied to both aqueous and non-aqueous systems. When used in an aqueous system, water, and in some cases, water-miscible solvent such as alcohol solvent or glycol ether solvent is used. The solvent may be replaced with a mixed solvent, and the free carboxylic acid in the polymer may be neutralized with ammonia or an organic amine, or the nitrogen-containing basic group in the polymer may be neutralized with an inorganic acid or an organic acid before use.

The radical polymerization of the above-mentioned monomer is a conventionally known method, for example, the reaction temperature is about 50 ° C to 220 ° C.
As the polymerization solvent, there are cellosolve type solvents, carbitol type solvents, glyme type solvents, cellosolve acetate type solvents, alcohol type solvents, aromatic hydrocarbon type solvents, ketone type solvents, ether type solvents, water, etc. The single solvent or the mixed system can be mentioned.

Examples of the organic dye used in the present invention include phthalocyanine type, insoluble azo type, azo lake type, anthraquinone type, quinacridone type, dioxazine type, diketopyrrolopyrrole type, anthrapyridine type,
Ansanthurones, indanthrone, flavanthrone, perinone, perylene, thioindigo, etc. Examples of the heterocycle include thiophene, furan, xanthene, pyrrole, imidazole, isoindoline, isoindolinone, benzimidazolone, indole, quinoline, carbazole, acridine, acridone, and anthraquinone. Alternatively, the heterocycle has a primary amino group or a secondary amino group introduced according to a conventional method. For example, an amino group is introduced by introducing a phthalimide group into an organic dye or a heterocycle and then hydrolyzing it.

The bond between the organic dye and / or the heterocycle and the polymer is formed by combining the primary amino group or the secondary amino group in the organic dye and / or the heterocycle with the acid chloride group in the acrylic polymer. , Water, alcohol, acetone, or a reaction solvent such as N, N-dimethylformamide, in some cases, in the presence of an alkali catalyst, to give rise to the reaction, and then the solvent may be removed. Since the acid chloride group is much more reactive than the carboxyl group and the sulfone group, it is possible to carry out the reaction with an amino group or the like under milder conditions, and further it is possible to obtain the target product in a high yield. In this respect, the present invention utilizing such a group is industrially very excellent.

The pigment dispersant of the present invention exerts an excellent dispersing effect on pigments which are generally commercially available. For example, soluble and insoluble azo pigments, azo pigments such as condensed azo pigments,
Phthalocyanine pigments, quinacridone pigments, isoindolinone pigments, perylene / perinone pigments, dioxazine pigments, anthraquinone pigments, diketopyrrolopyrrole pigments, anthrapyrimidine pigments, ansanthrone pigments, indanthrone pigments , Organic pigments such as flavanthron-based pigments and thioindigo-based pigments, and inorganic pigments such as carbon black, titanium oxide, yellow lead, cadmium yellow, cadmium red, rouge, iron black, zinc white, navy blue, ultramarine it can. The content of the pigment dispersant of the present invention in the pigment is 0.5 to 100 parts by weight of the pigment.
100 parts by weight is preferred. If the amount is less than 0.5 parts by weight, the effect of dispersing the pigment is small, which is not preferable. Further, even if it is used in an amount of more than 100 parts by weight, the effect of the used amount cannot be obtained and the coating film performance is adversely affected.

The method of using the pigment dispersant of the present invention includes:
For example, there are the following methods. 1. A pigment composition obtained by previously mixing a pigment and a pigment dispersant is added to and dispersed in a non-aqueous vehicle or an aqueous vehicle. 2. A pigment and a pigment dispersant are added to a non-aqueous or aqueous vehicle and dispersed. 3. The pigment and the pigment dispersant are separately dispersed in a non-aqueous or aqueous vehicle in advance, and the resulting dispersion is mixed. In this case, the pigment dispersant may be dispersed only with the solvent. 4. After dispersing the pigment in the non-aqueous or aqueous vehicle, the pigment dispersant is added to the obtained pigment dispersion. The desired effects can be obtained by any of these methods.

As a method for preparing the pigment composition, a sufficient dispersion effect can be obtained by simply mixing the pigment powder and the pigment dispersant of the present invention. However, a kneader, a roll, an attritor, a super mill, and various pulverizers. , Mechanically mixing with a disperser or the like, or adding a solution containing the pigment dispersant of the present invention to a suspension system of pigment or water or an organic solvent to deposit the pigment dispersant on the pigment surface, or to add strong sulfuric acid or the like. Even better results can be obtained by performing a careful mixing method such as co-dissolving an organic pigment and a pigment dispersant in a solvent having a dissolving power and coprecipitating with a poor solvent such as water. Further, a non-aqueous or aqueous vehicle, or for dispersing or mixing a pigment or a pigment dispersant in a solvent, as a dispersing machine, a dissolver, a high speed mixer, a homomixer, a kneader, a roll mill,
The pigment can be well dispersed by using a sand mill or an attritor.

[0017]

EXAMPLES The present invention will be described below based on examples.
In the examples, “parts” and “%” are “parts by weight” and “% by weight”, respectively.
Respectively.

Production Example 1 300 g of toluene was charged into a four-necked flask equipped with a thermometer, a stirrer, a reflux condenser and a nitrogen gas inlet tube, and 60
Heated to ° C. Next, a mixture of acrylic acid 10 parts, ethyl acrylate 114 parts, methyl methacrylate 101 parts, vinyl acetate 25 parts, methacryloyl chloride 5 parts and AIBN (manufactured by Wako Pure Chemical Industries, Ltd.) 5 parts toluene 100 parts was introduced with nitrogen gas. While dropping, it took about 2 hours. Further, the reaction was carried out for 2 hours while maintaining the same temperature to obtain a polymer solution. The number average molecular weight of this polymer is 900
The acid value was 0 and the acid value was 30 mg · KOH / g. Further, 28.9 parts of aminomethyl copper phthalocyanine was added to a mixture containing 300 parts of toluene and 11.1 parts of triethylamine, and the mixture was reacted at 90 ° C. for 2 hours. Unreacted materials and solvent were removed to obtain a paste containing 256 parts of compound (a).

Production Example 2 To a four-necked flask equipped with a thermometer, a stirrer, a reflux condenser and a nitrogen gas inlet tube, 350 g of toluene was charged, and 60
Heated to ° C. Next, a mixture of acrylic acid 3 parts, ethyl acrylate 121 parts, methyl methacrylate 101 parts, vinyl acetate 25 parts, methacryloyl chloride 4 parts and AIBN (manufactured by Wako Pure Chemical Industries, Ltd.) 2 parts toluene 50 parts was introduced with nitrogen gas. While dropping, it took about 2 hours. Further, the reaction was carried out for 2 hours while maintaining the same temperature to obtain a polymer solution. The number average molecular weight of this polymer is 200
00, the acid value was 10 mg · KOH / g. Further, 23.2 parts of aminomethylcopper phthalocyanine was added to a mixture containing 300 parts of toluene and 7.7 parts of triethylamine, and the mixture was reacted at 90 ° C. for 2 hours. Unreacted materials and solvent were removed to obtain a paste containing 250 parts of compound (b).

Production Example 3 400 parts of water was added to the paste containing 100 parts of the compound (a) obtained in Production Example 1 to replace the solvent with water, and the mixture was neutralized with dimethylaminoethanol to prepare an aqueous solution of the compound (c). I got a paste. The aqueous paste had a pH of 8.3.

Production Example 4 To a four-necked flask equipped with a thermometer, a stirrer, a reflux condenser, and a nitrogen gas inlet tube was charged 350 g of toluene, and 60
Heated to ° C. Next, a mixture of acrylic acid 19 parts, ethyl acrylate 113 parts, methyl methacrylate 93 parts, vinyl acetate 25 parts, methacryloyl chloride 4 parts and AIBN (Wako Pure Chemical Industries, Ltd.) 2 parts toluene 50 parts was introduced with nitrogen gas. While dropping, it took about 2 hours. Further, the reaction was carried out for 2 hours while maintaining the same temperature to obtain a polymer solution. The number average molecular weight of this polymer is 250
00, the acid value was 60 mg · KOH / g. Further, 23.2 parts of aminomethyl copper phthalocyanine was added to a mixture containing 300 parts of methanol and 7.7 parts of triethylamine, and the mixture was reacted at 90 ° C. for 2 hours. Unreacted materials and solvent were removed to obtain a paste containing 252 parts of compound (d). 40 parts of water was added to a paste containing 100 parts of this compound (d).
After 0 part was added and the solvent was replaced with water, the mixture was neutralized with dimethylaminoethanol to obtain an aqueous paste of compound (e).
The aqueous paste had a pH of 8.1.

Production Example 5 After synthesizing 28.9 parts of aminomethylcopper phthalocyanine of Production Example 1 to 16.3 parts of aminomethylquinacridone, the unreacted material and solvent were removed to give compound (f) 245.
A paste containing parts was obtained. To a paste containing 100 parts of this compound (f) was added 400 parts of water to replace the solvent with water, and the mixture was neutralized with dimethylaminoethanol to give the compound (g).
An aqueous paste of was obtained. This aqueous paste has a pH of 8.
It was one.

Production Example 6 After synthesizing 28.9 parts of aminomethylcopper phthalocyanine of Production Example 1 into 10.7 parts of 2-aminoanthraquinone, unreacted materials and solvent were removed to contain 238 parts of compound (h). I got a paste. After adding 400 parts of water to a paste containing 100 parts of this compound (h) and replacing the solvent with water,
Neutralization with dimethylaminoethanol gave an aqueous paste of compound (i). This aqueous paste had a pH of 8.0.

Production Example 7 After synthesizing 23.2 parts of aminomethylcopper phthalocyanine of Production Example 2 to 13.1 parts of aminomethylquinacridone, the unreacted substances and solvent were removed to give compound (j) 239.
A paste containing parts was obtained.

Production Example 8 After synthesizing 23.2 parts of aminomethylcopper phthalocyanine of Production Example 2 into 23.7 parts of aminomethyldioxazine, the unreacted material and solvent were removed to give compound (k) 252.
A paste containing parts was obtained.

Production Example 9 After 23.2 parts of aminomethylcopper phthalocyanine of Production Example 2 was replaced with 8.5 parts of 2-aminoanthraquinone, the unreacted material and solvent were removed to contain 235 parts of compound (l). I got a paste.

Production Example 10 After 23.2 parts of aminomethylcopper phthalocyanine of Production Example 4 was changed to 13.1 parts of aminomethylquinacridone, the unreacted material and solvent were removed to give compound (m) 242.
A paste containing parts was obtained. To a paste containing 100 parts of this compound (m) was added 400 parts of water to replace the solvent with water, and the mixture was neutralized with dimethylaminoethanol to give the compound (n).
An aqueous paste of was obtained. This aqueous paste has a pH of 8.
It was 2.

Production Example 11 After 23.2 parts of aminomethylcopper phthalocyanine of Production Example 4 was changed to 8.5 parts of 2-aminoanthraquinone, the unreacted material and solvent were removed to give compound (o) 235.
A paste containing parts was obtained. To a paste containing 100 parts of this compound (o), 400 parts of water was added, the solvent was replaced with water, and the mixture was neutralized with dimethylaminoethanol to give the compound (p).
An aqueous paste of was obtained. This aqueous paste has a pH of 8.
It was 4.

Production Example 12 After 23.2 parts of aminomethyl copper phthalocyanine of Production Example 4 was changed to 23.7 parts of aminomethyldioxazine, the unreacted substances and the solvent were removed to give compound (q) 250.
A paste containing parts was obtained. After adding 400 parts of water to a paste containing 100 parts of this compound (q) and substituting the solvent with water, it was neutralized with dimethylaminoethanol to give the compound (r).
An aqueous paste of was obtained. This aqueous paste has a pH of 8.
It was 2.

Examples 1 to 18 and Comparative Examples 1 to 7 As shown in Table 1, pigments and alkyd resins synthesized in Production Examples ("Phtalkid 133-6" manufactured by Hitachi Chemical Co., Ltd.).
0 ”) and xylene are mixed and dispersed, and then melamine resin (“ Uban 20SE6 ”manufactured by Mitsui Cytec Co., Ltd.)
0 ") was blended to obtain an alkyd resin / amino resin based coating material. When the viscosity of each paint was measured, as shown in Table 1, the one according to the present invention had smaller thixotropy (TI value) than the comparative example, and showed excellent fluidity. In addition, the viscosity of the above paint was adjusted with a Ford cup # 4 for 20 seconds, and an intermediate coated plate (a steel plate preliminarily coated with a primer paint and water-polished) had a dry coating film thickness of about 30 μm. It was painted with air spray, left standing for 10 minutes, and then baked at 140 ° C. for 30 minutes. As shown in Table 1, the coating film gloss of the present invention was also superior to that of the comparative example. In addition, non-aggregation and non-crystallinity were evaluated based on color separation stability, which is particularly problematic in practical use. The paint is cut with a titanium oxide base paint so that the ratio of the pigment to the titanium oxide is 1/10, and a light color paint is prepared. Then, when diluted with xylene and adjusted in viscosity and then injected into a test tube and observed the change of the glass wall surface, the one according to the present invention showed less color separation over time than the comparative example.

[0031]

[Table 1]

Examples 19 to 31, Comparative Examples 8 to 14 As shown in Table 2, pigments, compounds synthesized in Production Examples, water-soluble acrylic copolymer resin solutions (weight average molecular weight 250
00, acid value 60 mg KOH / g, acrylic acid / ethyl acrylate / methyl methacrylate / vinyl acetate copolymer, solid content 20%) and ion-exchanged water were mixed and dispersed, and then melamine resin (Mitsui Cytec Co., Ltd.). Made "Cymel 30
3 ”) was blended to obtain a water-based acrylic resin / amino resin-based coating material. The resulting waterborne paint was developed on a PET film with a 4 mil film applicator and baked at 140 ° C for 30 minutes. As shown in Table 2, the coating gloss of the present invention was superior to that of the comparative example.

[0033]

[Table 2]

[0034]

Industrial Applicability According to the present invention, it is possible to remarkably improve the suitability for use such as non-aggregation and fluidity, and the sharpness of the color tone and gloss of the coating material in the aqueous and non-aqueous pigment dispersion liquids such as ink and paint. I was able to.

Claims (2)

[Claims] 1. A pigment dispersant characterized by reacting an acrylic polymer having an acid chloride group with an organic dye and / or a heterocycle having a primary amino group or a secondary amino group. . 2. A pigment composition comprising a pigment and the pigment dispersant according to claim 1.