JPH09122472A - Dispersant and colorant - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a dispersant and a colorant free from various problem such as the deterioration of gloss of a coat when applied, degradation of clearness, opaqueness, a decrease in tinting strength and color separation and capable of stably dispeising pigments. SOLUTION: This dispersant is used for the dispersion of pigment and is composed of an ester methacrylate polymer comprising essential components such as an aromatic vinyl monomer, a monomer of ester methacrylate containing primary-tertiary amino groups and a monomer of ester methacrylate containing a quaternary ammonium group produced by an aromatic compound as monomer components.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a dispersant for pigments and a colorant using the dispersant, and more specifically, surface treatments for various paints such as paints for woodwork and paints for construction materials, artificial leather, synthetic leather and the like. In addition to the ink field of adhesives, gravure inks, offset inks, various resin fields of thermoplastic resins, thermosetting resins, adhesives, etc., in addition, since the light transmittance of the formed coating film is good , A pigment dispersant and a colorant which are useful in many fields such as the field of color filters.

[0002]

2. Description of the Related Art Conventionally, pigments generally have poor dispersibility in a medium as they are, and therefore, when blended in paints, inks or resins, the pigments are dispersed in a pigment dispersion resin (dispersant). Used as a color concentrate or a colorant, but when the dispersibility of the pigment in such a resin dispersant is poor, the pigment agglomerates. For inks, paints, resin molded products, etc. prepared using a colorant containing pigment particles, the resulting coating film may have various effects such as a decrease in gloss, a decrease in sharpness, an opacity, a decrease in coloring power and a color separation. However, such a colorant cannot sufficiently exhibit the performance of the pigment when it is made into an ink or a paint, or when the resin is colored.

[0003]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to reduce the gloss, the sharpness, and the opacity of a coating or colored resin when the coating is formed from ink or paint or the resin is colored. It is an object of the present invention to provide a dispersant capable of stably dispersing a pigment and a colorant containing the dispersant, which eliminates various problems such as deterioration in color, deterioration of coloring power and color separation.

[0004]

The above objects are achieved by the present invention described below. That is, in the present invention, as a monomer component, an aromatic vinyl monomer, a primary to tertiary amino group-containing (meth) acrylic acid ester monomer, and an aromatic compound are used.
A dispersant for a pigment, which comprises a (meth) acrylic acid ester-based polymer containing a (meth) acrylic acid ester monomer having a graded ammonium group as an essential component, and a colorant containing the dispersant. .

According to the present invention, the side chain has an aromatic group from 1 to
It was found that an acrylic acid ester-based polymer having a tertiary amino group and a quaternary ammonium group as a pendant is excellent as a pigment dispersant. In the dispersant,
The above-mentioned aromatic group exhibits excellent affinity for pigments (particularly organic pigments), primary to tertiary amino groups and quaternary ammonium group exhibit excellent wettability to pigments, and an acrylic ester as a main chain The base polymer has excellent compatibility with the vehicle of ink, paint, or the material to be colored such as resin.
Therefore, the colored article with the colorant of the present invention is excellent in gloss, vividness, transparency, coloring power and color separation prevention property, and in particular, no aggregation of pigments is observed, and it is very excellent in transparency equivalent to coloring with a dye. To feel.

[0006]

Next, the present invention will be described in more detail with reference to preferred embodiments. The main chain of the dispersant of the present invention is an acrylic acid ester polymer, and the main chain is characterized by having an aromatic ring, a primary to tertiary amino group, and a quaternized ammonium group as a side chain. The dispersant is
It is manufactured by the following method. (1) A method of polymerizing the necessary monomer components and then quaternizing a part of the primary to tertiary amino groups in the obtained polymer. (2) A method of copolymerizing a quaternized monomer as a monomer with another monomer.

In the dispersant of the present invention, examples of the aromatic vinyl monomer which is an essential monomer component include, for example, styrene, α-methylstyrene, vinyltoluene, vinylnaphthalene, vinylanthracene, vinylanthraquinone and aromatic amine (meth). ) Acrylamide, (meth) acrylate of a hydroxyl group-containing aromatic compound, and the like. As the aromatic amine, aniline, benzylamine,
Examples thereof include naphthylamine, aminoanthracene, aminoanthraquinone and derivatives thereof. Examples of the hydroxyl group-containing aromatic compound include hydroxyl group-containing compounds corresponding to the above amino compounds.

The above aromatic vinyl monomer is not generally determined by its aromatic group in the dispersant of the present invention, but is generally 10 per 100 parts by weight of the polymer.
-60 parts by weight, preferably 20 to 50 parts by weight. When the content of the aromatic vinyl monomer is less than 10 parts by weight, the effect of improving the pigment dispersibility of the obtained dispersant is small, and when it exceeds 60 parts by weight, the Tg of the obtained dispersant becomes too high. In some cases, the compatibility with the material to be colored is reduced, and color unevenness may occur in the material to be colored.

In the dispersant of the present invention, as the acrylate ester monomer containing a primary to tertiary amino group, which is an essential monomer component, for example, N-alkylaminoalkyl (meth) acrylate, N, N-dialkylaminoalkyl ( (Meth) acrylate, γ- (N-alkylamino) -β-hydroxy-propyl (meth) acrylate, γ- (N-dialkylamino) -β-hydroxy-
Propyl (meth) acrylate, γ- (N, N-dialkylamino) -β-hydroxy-propyl (meth) acrylate, N, N-dialkylaminoalkyl (meth)
Acrylamide and the like can be mentioned. The alkyl group in these monomers is C _{1 to} C ₂₀ , preferably C ₁
To C ₆ alkyl groups.

The above-mentioned primary to tertiary amino group-containing acrylic acid ester monomers are not unconditionally determined in relation to other monomers in the dispersant of the present invention, but generally 2 to 15 per 100 parts by weight of the polymer. It is used in an amount of about 10 parts by weight, preferably 5 to 10 parts by weight. 1-3
If the content of the primary amino group-containing acrylic acid ester monomer is less than 2 parts by weight, the wettability of the obtained dispersant to the pigment is insufficient, and if it exceeds 15 parts by weight, the hydrophilicity of the obtained dispersant is high. The property becomes too high, and the compatibility with hydrophobic ink media, paint media, or various resins decreases.

In the dispersant of the present invention, the quaternary ammonium group-containing acrylic acid ester monomer, which is an essential monomer component, is a quaternized product of the above-mentioned primary to tertiary amino group-containing acrylic acid ester monomers, for example, 4 As the quaternizing agent, alkyl halides such as methyl chloride, methyl bromide, methyl iodide, ethyl chloride, ethyl bromide and ethyl iodide can be used, but the preferred quaternizing agent is an aromatic compound. Specific examples thereof include benzyl chloride, benzyl bromide, benzyl iodide, chloromethylnaphthalene, bromomethylnaphthalene, methyl iodonaphthalene, and their derivatives. By using the acrylic ester monomer quaternized with these aromatic compounds, the dispersibility of the pigment is further improved.
These quaternary ammonium groups have a predetermined ratio of 1 to 3 amino groups in the polymer after polymerization of the monomer composition.
It may be quaternized and introduced into the polymer, or polymerization may be carried out using a quaternized monomer to introduce a quaternary ammonium group into the polymer.

The quaternary ammonium group-containing acrylic acid ester monomer is not generally determined in the dispersant of the present invention in relation to other monomers, but is generally 1 to 10 parts by weight per 100 parts by weight of the polymer. , Preferably 3 to 8 parts by weight. When the content of the quaternized ammonium group-containing acrylic acid ester monomer is less than 1 part by weight, the wettability of the resulting dispersant with respect to the pigment and the dispersion stability are insufficient. On the other hand, if it exceeds 10 parts by weight, the hydrophilicity of the resulting dispersant becomes too high and the compatibility with the hydrophobic ink medium, coating medium, or various resins decreases.

In the present invention, in addition to the above monomers, other monomers can be copolymerized depending on the type of pigment, the material of the material to be colored and the like. The other monomer may be any monomer as long as it is a monomer copolymerizable with the above-mentioned monomer, and examples thereof include (meth) acrylic acid, itaconic acid, maleic acid, fumaric acid, etc. 1-20 alkyl (eg, methyl, ethyl, propyl, butyl, pentyl, cyclohexyl, etc.) esters, aryl esters, arylalkyl esters, and further (meth) acrylic acid and polyols,
For example, ethylene glycol, diethylene glycol,
Triethylene glycol, tetramethylene glycol,
Polyethylene glycol, propylene glycol, dipropylene glycol, polypropylene glycol, 1,
3-pentanediol, 1,4-butanediol, 1,
Monoesters such as 6-hexanediol, glycerin, diglycerin, etc., alkoxyethyl (meth) acrylate, vinyl acetate, (meth) acrylonitrile, (meth)
Examples thereof include acrylamide, vinyl chloride, vinylidene chloride, vinyl pyridine and the like.

The above-mentioned copolymerizable monomer is not generally determined in the dispersant of the present invention in relation to other monomers, but is generally 0 to 70 parts by weight, preferably 30 parts by weight per 100 parts by weight of the polymer. Used in a proportion of -60 parts by weight. As these copolymerizable monomers, it is preferable to use hydrophobic monomers or hydroxyl group-containing monomers.

The dispersant of the present invention is prepared by mixing the above-mentioned monomers at a predetermined ratio or by sequentially adding them as the polymerization proceeds, for example, a conventionally known mixed polymerization method such as a solution polymerization method, a suspension polymerization method or an emulsification method. It can be obtained by any polymerization method such as a polymerization method. When a polymer having a hydroxyl group at the terminal is required, another monomer is polymerized first, and then the hydroxyl group-containing monomer is added dropwise to the polymerization solution during the polymerization to carry out the polymerization.

If necessary, known additives such as polymerization regulators and chain transfer agents may be used to appropriately adjust the molecular weight of the resulting polymer. Although the molecular weight of the dispersant of the present invention thus obtained is not particularly limited, it is in the range of about 1,000 to 100,000 considering the dispersibility of the pigment, the viscosity of the colorant, and the like. The preferred range is 3,000 to 50,000.

The pigment used in the present invention is a pigment that has been conventionally used in various fields, and any known pigment can be used in the present invention. Specifically, phthalocyanine type, azo type, condensed azo type, azo lake type, anthraquinone type, perylene / perinone type, indigo / thioindigo type, isoindolinone type, azomethine azo type, dioxazine type, quinacridone type, aniline black type, Organic pigments such as triphenylmethane type, carbon black type, titanium oxide type, iron oxide type, iron hydroxide type, chromium oxide type, spinel type firing type, chromic acid type, chrome vermillion type, dark blue type, aluminum powder type , Bronze powder system and the like. These pigments may be in any form, and these pigments may be subjected to various dispersion treatments by various known methods.

The colorant of the present invention can be obtained by kneading the dispersant and the pigment with a kneader such as a sand grind mill, a ball mill, an attritor mill or a three roll mill. At this time, the dispersant is used in the range of about 10 to 500 parts by weight per 100 parts by weight of the pigment. When kneading the dispersant and the pigment, for example, by mixing the dispersant with a powdery pigment (with an appropriate amount of an organic solvent as necessary), for example, by mixing and kneading meat in a three-roll mill, It is possible to obtain a colorant having excellent transparency with very few aggregated particles of the pigment. The colorant obtained may be in the form of powder, chips, paste containing an organic solvent, or liquid in which an organic solvent is a medium, and the shape thereof is not particularly limited and may be selected depending on the coloring application. Further, the colorant may include various additives such as an organic solvent, a film-forming resin that is not present in a large amount, a flame retardant, an antioxidant, an ultraviolet absorber, a plasticizer, and a surfactant depending on the target coloring material. It can be added.

The colorant of the present invention obtained as described above is, for example, various paints such as paints for woodwork and paints for building materials, surface treatment agents for artificial leather, synthetic leather, inks such as gravure ink and offset ink. Fields, thermoplastic resins, thermosetting resins, various resin fields such as adhesives, as well as other, because the light transmittance of the coating film formed is good,
It is useful in many fields such as the color filter field.

[0020]

EXAMPLES The present invention will be described more specifically with reference to Examples and Comparative Examples below. In the following, "parts" and "%" are based on weight unless otherwise specified. Example 1 Methyl methacrylate 5.0 parts Butyl methacrylate 46.5 parts Styrene 38.5 parts N, N-Dimethylaminoethyl methacrylate 5.0 parts N, N, N-Dimethyl-benzylammonium ethyl methacrylate 5.0 parts Toluene 500 Parts The above components were mixed and dissolved, and 2.0 parts of azobisisobutyronitrile was dissolved in this solution. This was polymerized at 85 to 90 ° C. for 5 hours to obtain a viscous polymerization solution. Toluene was distilled off from the polymerization solution to obtain a paste-like dispersant having a solid content of about 30%.

Examples 2 to 5 and Comparative Examples 1 to 2 The monomer composition in Example 1 was changed to the monomer composition shown in Table 1 below, and the dispersants of the present invention and Comparative Examples were obtained in the same manner as in Example 1 below. It was The molecular weight of the obtained dispersant is shown in Table 2.
It is as follows. The numerical values in the column of Table 1 are parts by weight.
Table 1

Table 2

Example 6 100 parts of the dispersant of Example 1 (solid content 30%) and a disazo yellow pigment (Seika Fast Yellow 2 manufactured by Dainichi Seika Kogyo Co., Ltd.)
720) 60 parts of cyclohexanone and 240 parts of cyclohexanone were premixed with a disper and then passed through a three-roll mill for 2 passes to obtain a paste-like colorant of the present invention. Examples 7 to 12 and Comparative Examples 3 to 5 The dispersant and the pigment in Example 6 were changed as shown in Table 3 below, and the pigment was dispersed by an appropriate kneader to obtain the colorants of the present invention and the comparative example. Obtained. The numerical values in the column are parts by weight.

Table 3

Resin Synthesis Example 1 To 150 parts of 1,4-adipate having an average molecular weight of 2,000 and 4.4 parts of 1,3-butanediol, 34.3 parts of isophorone diisocyanate was added, and the mixture was mixed at 4 ° C. at 100 ° C. After reacting for a time, N, N-dimethylformamide was added to 470.
Add 9 parts and add isophoronediamine 1 with a dropping funnel.
3.1 parts was gradually added dropwise, solid content 30%, viscosity 200P
a. s polyurethane resin (PU-1) (molecular weight about 10
10,000) was obtained.

Resin Synthesis Example 2 150 parts of 1,4-adipate having an average molecular weight of 1,500,
1,4-Butanediol 18.5 parts, N, N-dimethylformamide 287.0 parts and methyl ethyl ketone 28
To 7.5 parts of the mixture, 77.5 parts of diphenylmethane-4,4-diisocyanate was added and reacted at 80 ° C. for 5 hours to give a solid content of 30% and a viscosity of 500 dPa.s. Polyurethane resin (PU-2) of s (molecular weight about 150,000) was obtained.

25 parts of colorant of Example 6, polyurethane resin
100 parts of fat (PU-1) and solvent (N, N-dimethyl)
50 parts of formamide) is thoroughly stirred with a disper and painted yellow
Charge No. 1) was obtained. Similarly, apply the composition shown in the table below.
Got paid. Table 4* 1: Dianal made by Mitsubishi Rayon  * 2: MPR-TAO manufactured by Nissin Chemical Industry  * 3: Zeon 400 * 150S Made by Zeon Corporation  * 4: Phtalkid manufactured by Hitachi Chemical

Each coating material obtained in the above Examples and Comparative Examples was applied onto a polypropylene film with a clearance of 50 μm and dried to obtain each coated product. The results for these coatings are shown in Table 5 below.

Table 5 In addition, No. 8 to 10 are comparative examples.

The evaluation methods in Table 5 are as follows. 1. Coloring power, gloss, transparency and sharpness ⊙; extremely good ∘; good Δ; somewhat good ×; poor Color separation (comparison between paint immediately after stirring and paint left for 15 hours) ○: No color separation ×: Color separation Haze

[0032]

EFFECT OF THE INVENTION According to the present invention as described above, an acrylate polymer having an aromatic group, a primary to tertiary amino group and a quaternary ammonium group as a pendant in its side chain is excellent as a dispersant for pigments. I found that. In the dispersant, the aromatic group exhibits excellent affinity for pigments (particularly organic pigments), and the primary to secondary amino groups are 4 and 4.
The quaternary ammonium group shows excellent wettability to the pigment,
The acrylic ester polymer, which is the main chain, has excellent compatibility with coloring materials such as vehicles of inks and paints or resins. Therefore, the colored article with the colorant of the present invention is excellent in gloss, vividness, transparency, coloring power, and color separation prevention property, in particular, no aggregation of pigment is observed, and it is very excellent in transparency equivalent to coloring with a dye. To feel.

Front Page Continuation (72) Inventor Masayuki Inabe 1-7-6 Nihonbashi-Bakurocho, Chuo-ku, Tokyo Dainichi Seika Kogyo Co., Ltd.

Claims (7)

[Claims] 1. As a monomer component, an aromatic vinyl monomer, a (meth) acrylic acid ester monomer containing a primary to tertiary amino group and a (meth) acrylic acid ester monomer having an ammonium group quaternized with an aromatic compound are used. A dispersant for a pigment, comprising a (meth) acrylic acid ester-based polymer as an essential component. 2. The pigment dispersant according to claim 1, which contains other copolymerizable monomer components. 3. The pigment dispersant according to claim 1, wherein the other copolymerizable monomer component contains a (meth) acrylic acid ester monomer. 3. The pigment dispersant according to claim 1, wherein the aromatic vinyl monomer is selected from styrene, vinylnaphthalene, vinylanthracene and derivatives thereof. 4. The pigment dispersant according to claim 1, wherein the (meth) acrylic acid ester monomer containing a primary to tertiary amino group is a dialkylaminoalkyl ester of (meth) acrylic acid. 5. A (meth) acrylic acid ester monomer having an ammonium group quaternized with an aromatic compound,
The dispersant for a pigment according to claim 1, which is obtained by quaternizing a dialkylaminoalkyl ester of (meth) acrylic acid with an aromatic compound. 6. The pigment dispersant according to claim 1, wherein the monomer component ratio is in the following range. (Meth) acrylic acid ester monomer 0 to 70 parts by weight Aromatic vinyl monomer 10 to 60 parts by weight Primary to tertiary amino group-containing (meth) acrylic acid ester monomer 2 to 15 parts by weight Quaternary ammonium group-containing (meth) acrylic acid Ester monomer 1 to 10 parts by weight 7. A pigment and a dispersant, wherein the dispersant comprises:
A colorant, which is the dispersant according to claim 1.