JP2697277B2 - Pigment dispersion liquid - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to inorganic or organic solvents such as toluene, xylene, Solvesso 100 (manufactured by Esson), Solvesso 200 (manufactured by Esson), and mineral terpenes. When fine powdered solids such as organic pigments are dispersed,
Dispersants capable of imparting excellent fluidity and dispersion stability to the dispersion system, easy dispersibility, especially non-aqueous dispersion type acrylic resin (NAD), mineral turpen soluble type modified acrylic resin, alkyd resin, The present invention relates to a pigment dispersion using a dispersant having a good compatibility with a vehicle or polymer for paint or ink using an aliphatic organic solvent as a diluent or solvent, such as a fatty acid-modified epoxy resin or a chlorinated rubber resin. Thus, its application range relates to coating compositions in general, such as printing inks and paints.

[Prior Art] Generally, an organic or inorganic pigment which is a component of a coloring material composition for various coatings such as a printing ink or a paint is formed of a fine powder. As in printing inks and paints,
When fine pigment particles are dispersed in an organic liquid containing a vehicle polymer, especially in a vehicle polymer using an aliphatic organic solvent, excellent fluidity, storage stability and dispersion stability at a high pigment concentration are obtained. Difficult to get things,
It often causes a variety of problems that have a significant effect on the manufacturing process as well as the quality of the resulting product.

For example, in the case of a non-aqueous dispersion type acrylic resin, the dispersion is broken during the pigment dispersion step. Also, in an aliphatic organic solvent, it is difficult to adsorb the vehicle polymer on the pigment surface, the degree of aggregation of the pigment is large, and a printing ink or paint using such a pigment dispersion has a stable dispersion state. Compared with the holding printing ink and paint, the color density at the time of color development, coloring power, sharpness is inferior, the coating surface loses smoothness due to unevenness due to coarse aggregates, and the gloss tends to decrease, Therefore, the commercial value of the object to be coated or the printed matter is lost.

Conventionally, various methods have been proposed to solve these problems. For example, (1) Non-aqueous dispersion type acrylic resin is a method using a dedicated pigment dispersing vehicle polymer, and (2) Ester vehicle polymer such as alkyd resin and fatty acid modified epoxy resin is described in US Pat. No. 3,940,353. A method of dispersing a pigment using a copolymer containing 40 to 60% by weight of the disclosed isobornyl acrylate, (2) a nonionic, anionic, cationic surfactant or an aliphatic polycarboxylic acid A method of dispersing a pigment by using a wetting agent such as the above as an auxiliary, (4) JP-A-55-112273, British Patent No. 13
No. 13745, U.S. Pat. No. 4,294,620, urea derivatives, and urethanes disclosed in British Patent No. 1,445,104, JP-B-58-24433, JP-A-60-166318, etc. Derivatives or US Patent No. 4317
A method of dispersing a pigment using an amide derivative disclosed in, for example, Japanese Patent No. 682 is known.

[Problems to be Solved by the Invention] However, the method using the dedicated pigment dispersing vehicle polymer as in the above (1) is effective only when the non-aqueous dispersion type acrylic resin is used as the vehicle polymer. The pigment dispersion obtained as in (2) is effective for those using an aromatic organic solvent such as xylene or toluene as a diluent or solvent, but diluting an aliphatic organic solvent. No effect was obtained with those used as agents or solvents.

[Means for Solving the Problems] The present inventors have conducted intensive studies to solve the problems of the prior art, and as a result, dispersed a fine powdery solid, particularly an organic or inorganic pigment, in an organic solvent. In this case, it has been found that the use of a specific modified acrylic polymer as a dispersant makes it possible to form a stable pigment dispersion that has solved the above-mentioned problems, and has completed the present invention.

That is, the present invention comprises a pigment, an organic solvent, and a copolymer for a dispersant, wherein the dispersant is an isobornyl ester of an α, β-unsaturated carboxylic acid and an α, β-unsaturated A copolymer having a weight average molecular weight of 1,000 to 50,000 containing carboxylic acid as an essential monomer component and containing 63 to 80% by weight of an isobornyl ester of an α, β-unsaturated carboxylic acid in the monomer component; The solvent / dispersant weight ratio is (10-70) / (5-7
0) / (5-80), a pigment dispersion,
And a paint comprising the pigment dispersion and a dye vehicle polymer containing an aliphatic organic solvent as a diluent or solvent.

Hereinafter, the dispersant used in the pigment dispersion of the present invention will be described in detail.

As the isobornyl ester of an α, β-unsaturated carboxylic acid used in the copolymer for a dispersant in the present invention, isobornyl (meth) acrylate represented by the following general formula (1) is particularly preferable. It is suitable.

(Wherein, X is _{-CH 2 -, - CH (CH} 3) - or -C (CH _3)
2- , M and R each represent a hydrogen atom or a methyl group. The content of the isobornyl ester of α, β-unsaturated carboxylic acid in the copolymer used in the present invention generally needs to be more than 63%, and in particular, an aliphatic organic solvent is used as a diluent or Good compatibility with vehicle polymer as solvent,
Excellent paint stability when colored with a pigment dispersion
It needs to be 63 to 80% by weight.

As the α, β-unsaturated carboxylic acid, methacrylic acid and acrylic acid are preferred, and methacrylic acid is particularly preferred.

The copolymer can be prepared by a known polymerization method. However, considering the use as a pigment dispersion, the solution polymerization method is preferred in that the operation of dissolving this copolymer in a solvent becomes unnecessary.

When the solution polymerization method is adopted, as the polymerization initiator, for example, a radical polymerization initiator such as azobisisobutyronitrile, benzoyl peroxide, and di-tert-butyl peroxide can be used.

As the polymerization solvent, for example, toluene, xylene and other high-boiling aromatic solvents; ester solvents such as ethyl acetate, butyl acetate and cellosolve acetate; ketone solvents such as methyl ethyl ketone and methyl isobutyl ketone; methyl alcohol; Alcohol solvents such as ethyl alcohol and butyl alcohol can be used alone or in combination, and among them, aromatic solvents are preferable. The amount used is 60% by weight so that the viscosity can be adjusted later
The following is preferred.

The copolymer used in the present invention can obtain a substantially satisfactory pigment dispersion even if the molecular weight changes, but there is no risk of causing a decrease in physical properties of the coating film, and the viscosity is appropriate. It is unnecessary, and in that a pigment dispersion having good pigment dispersibility can be easily obtained, the weight average molecular weight is 1,000 to 50,
000 copolymers are preferred, and especially the weight average molecular weight is
3,500-20,000 copolymers are particularly preferred.

Examples of the pigment used in the pigment dispersion of the present invention include, as inorganic pigments, (1) metal oxides such as titanium dioxide, red iron oxide and chromium oxide; (2) hydroxides such as alumina white and yellow iron oxide; (3) Sulfides such as zinc sulfide and cadmium yellow; selenides; (4) ferrocyanides; (5) chromates such as zinc and molybdenum red; (6) sulfates such as precipitated barium sulfate. system;
(7) carbonates such as calcium carbonate; (8) clay,
Silicates such as ultramarine blue; (9) phosphates such as manganese violet; (10) carbons such as carbon black; (11) metallics such as zinc powder and nickel powder; and organic pigments. Examples of (1) azo pigments: (2) lake pigments; (3) phthalocyanine pigments; (4) condensed polycyclic pigments (perylene, quinacridone,
Isoindolinone, dioxazine, etc.).

The weight ratio of the pigment / organic solvent / dispersant in the pigment dispersion of the present invention is not particularly limited, but is generally (10-70) / (5-70) / (5-80). .

The pigment dispersion of the present invention can be prepared, for example, by mixing together a pigment, a dispersant in an organic solvent, and, if necessary, an additional organic solvent in a suitable dispersing apparatus. Ball mills, roll mills, and ball mills commonly used in the paint industry
Examples include a homomixer, a sand mill, and an attritor.

Examples of the organic solvent used in the pigment dispersion of the present invention include aromatic organic solvents such as toluene, xylene, Solvesso 100 (manufactured by Exxon), Solvesso 200 (manufactured by Esson); mineral terpenes, V.M & P. naphtha, etc. Aliphatic organic solvents; ester solvents such as ethyl acetate, butyl acetate, and cellosolve acetate; ketone solvents such as methyl ethyl ketone and methyl isobutyl ketone; and these may be used alone or as a mixture of two or more. Among them, a mixture of an aromatic solvent and an aliphatic organic solvent is preferred.

The mixing ratio of the pigment dispersion of the present invention to the vehicle polymer depends on the kind of the pigment in the dispersion and the required degree of coloring, and can be changed in a wide range, and is not particularly limited. Per 100 parts by weight of polymer
It is in the range of 0.1 to 100 parts by weight.

The vehicle polymer to be used together with the pigment dispersion of the present invention in obtaining a printing ink or paint is not particularly limited, and may use an aromatic organic solvent as a diluent or a solvent, a non-aqueous dispersion type acrylic resin, or a terpen. Any of those using an aliphatic organic solvent as a diluent or a solvent, such as a soluble acrylic resin, an alkyd resin, a fatty acid-modified epoxy resin, and a chlorinated rubber resin, can be used.

As the diluent or solvent used here, any organic solvent used in the pigment dispersion of the present invention can be used.

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to Production Examples, Examples, and Comparative Examples. All parts and percentages in the examples are on a weight basis.

Production Example 1 28 parts of methyl methacrylate, 8 parts of ethyl acrylate,
1 part of methacrylic acid, 63 parts of isobornyl acrylate, 0.5 part of azobisisobutyronitrile, 18.5 parts of xylene and 35.5 parts of Solvesso 200 were reacted for 10 hours in a reactor equipped with a stirrer, thermometer and condenser, A copolymer (A-1) used as a dispersant in the present invention was obtained.

The obtained copolymer (A-1) was pale yellow and transparent, had a nonvolatile content of 64.7%, a viscosity of 28 ps (25 ° C.), and a weight average molecular weight of about 6,500.
Met.

Production Example 2 15 parts of methyl methacrylate, 0.5 part of methacrylic acid, 0.5 part of diethylaminoethyl methacrylate, 78 parts of isobornyl acrylate, 6 parts of ethyl acrylate, 0.5 part of azobisisobutyronitrile, 18.5 parts of xylene, and 35.5 parts of Solvesso 200 Was reacted in a reactor equipped with a stirrer, thermometer and condenser for 12 hours to obtain a copolymer (A-2) used as a dispersant in the present invention.

The obtained copolymer (A-2) was pale yellow and transparent, had a nonvolatile content of 64.2%, a viscosity of 35 ps (25 ° C.), and a weight average molecular weight of about 11,000.
Met.

Production Example 3 Methyl methacrylate 37 parts, 2-ethylhexyl acrylate 62 parts, methacrylic acid 1 part, azobisisobutyronitrile 0.5 part, xylene 18.5 parts and Solvesso 200 3
5.5 parts were reacted for 10 hours in a reactor equipped with a stirrer, a thermometer and a condenser, and a copolymer for comparison (B)
-1) was obtained.

The obtained copolymer (B-1) is colorless and transparent and has a non-volatile content.
The polymer had a viscosity of 63.8%, a viscosity of 16 ps (25 ° C.), and a weight average molecular weight of about 9,500.

Production Example 4 48 parts of methyl methacrylate, 51 parts of isobornyl methacrylate, 0.5 part of methacrylic acid, 0.5 part of diethylaminoethyl methacrylate, 0.5 part of azobisisobutyronitrile,
27 parts of xylene and 27 parts of Solvesso 200 were reacted in a reactor equipped with a stirrer, a thermometer and a condenser for 10 hours to obtain a copolymer (B-2) for comparison.

The obtained copolymer (B-2) was pale yellow and transparent, had a nonvolatile content of 64.7%, a viscosity of 14 ps (25 ° C.), and a weight average molecular weight of about 7,40.
It was 0.

Example 1 Red iron oxide [manufactured by Toda Kogyo KK; Todacolor 120R] 50
Parts, 45 parts of copolymer (A-1) and Solvesso 2005
Parts were weighed into a 200 ml glass bottle together with 120 parts of glass beads (1.5 m / m in diameter, the same applies hereinafter), shaken for 1 hour with a paint conditioner manufactured by Red Devil Co., and deflocculated to obtain a pigment dispersion of the present invention. I got

This pigment dispersion had good fluidity and a viscosity at 25 ° C. of 950 cps. No pigment separation was observed after storage for 10 days.

Next, a non-aqueous dispersion type acrylic resin [manufactured by Dainippon Ink and Chemicals, Inc .;
Mixture of Acridic A-188 = 60/40 (weight ratio of solids)], terpene soluble acrylic resin [manufactured by Dainippon Ink and Chemicals, Incorporated; Acrydic 54-113] or thermosetting alkyd resin [Large A mixture of Becsol 134 / Super-Beckamine G-821-60 = 70/30 (solid content weight ratio) manufactured by Nippon Ink Chemical Industry Co., Ltd.] as a vehicle. 20 parts each of the thinner weight ratio = 20/40/40), 2 parts of each of the pigment dispersions prepared above were added, and the mixture was uniformly mixed and stirred with a spatula to obtain a mixed enamel.

Apply each mixed enamel onto art paper with a 100-micron doctor blade, and after 30 seconds, rub the coated surface lightly with your finger to observe the color separation (the color of the part that was not rubbed with the finger rubbed) did. As a result, no color separation was observed for any of the mixed enamels. The gloss of the coating film after drying (baking) was also good.

Example 2 22 parts of phthalocyanine blue [manufactured by Sanyo Dye Co., Ltd .; cyanine blue 4033], 53 parts of copolymer (A-2) and 25 parts of Solvesso 200 were added together with 120 parts of glass beads to 200 ml.
It was weighed and placed in a glass bottle, shaken for 1 hour with a paint conditioner manufactured by Red Devil Co., and deflocculated to obtain a pigment dispersion of the present invention.

This pigment dispersion had good fluidity and a viscosity at 25 ° C. of 650 cps. No pigment separation was observed after storage for 10 days.

Next, a test was conducted in the same manner as in Example 1 except that this pigment dispersion was used. As a result, no color separation was observed and the gloss of the coating film was good.

Example 3 18 parts of quinacridone red pigment [manufactured by Dainippon Ink and Chemicals, Incorporated; Fastgen Super Red YE] 18 parts, copolymer (A-1) 50 parts, mineral terpene 5 parts, xylene 5 parts and Solvesso 100 22 The part was weighed together with 120 parts of glass beads in a 200 ml glass bottle, shaken with a paint conditioner manufactured by Red Devil Co. for 2 hours and peptized to obtain a pigment dispersion of the present invention.

This pigment dispersion had good fluidity and a viscosity at 25 ° C. of 460 cps. No pigment separation was observed after storage for 10 days.

Then, a drying oil fatty acid ester epoxy [manufactured by Dainippon Ink and Chemicals, Incorporated; epicron 4050 and soybean oil fatty acid were esterified using 50/50 (weight ratio of solid content), and then xylene / mineral terpene = 1 / 1 (weight ratio) mixed solvent dissolved at 50% solids. Acid value = 8.2], chlorinated rubber resin [Asahi Denka Kogyo Co., Ltd.]
CR-50 and Hitachi Chemical Co., Ltd .; Phthalkid 265-70
Of 10/25 (solid content ratio by weight), terpene soluble acrylic resin [manufactured by Dainippon Ink and Chemicals, Inc .; Acrydic 56-1148] or alkyd resin [manufactured by Hitachi Chemical Co., Ltd .; D601] as a vehicle, take 20 parts of each of the prepared white enamels (weight ratio of titanium oxide / resin solids / thinner = 20/40/40), and add 4 parts of each of the pigment dispersions prepared above, The mixture was uniformly mixed and stirred with a spatula. Each mixed enamel was applied on art paper with a 100-micron doctor blade, and after 30 seconds, a part of the applied surface was rubbed lightly with a finger to observe the state of color separation. As a result, no color separation was observed for any of the mixed enamels, and the gloss of the coating film was good.

Example 4 Carbon Black [Degussa; Special 100] 20
Parts, copolymer (A-2) 55 parts and Solvesso 150 25
The portion was weighed together with 120 parts of glass beads in a 200 ml glass bottle, shaken for 1 hour with a paint conditioner manufactured by Red Devil Co., and deflocculated to obtain a pigment dispersion of the present invention.

This pigment dispersion had good fluidity and a viscosity at 25 ° C. of 300 cps. No pigment separation was observed after storage for 10 days.

Then, a test was carried out in the same manner as in Example 3 except that this pigment dispersion was used. As a result, no color separation was observed and the gloss of the coating film was good.

Comparative Example 1 Red iron oxide [manufactured by Toda Kogyo KK; Todacolor 120R] 55
Parts, 45 parts of copolymer (B-1) and Solvesso 2005
The portion was weighed together with 120 parts of glass beads in a 200 ml glass bottle, shaken for 1 hour with a paint conditioner manufactured by Red Devil Co., and deflocculated to obtain a pigment dispersion for comparison.

This pigment dispersion had good fluidity and a viscosity at 25 ° C. of 650 cps. However, separation of the pigment was observed even after storage for 2 days.

Then, a test was conducted in the same manner as in Example 3 except that this pigment dispersion was used. As a result, there was color separation except for a mixture of white enamel prepared from an alkyd resin with a small amount of color separation. Generation of aggregated particles was observed.

Comparative Example 2 A phthalocyanine blue [manufactured by Sanyo Dye Co., Ltd .; cyanine blue 4033] (22 parts), copolymer (B-2) 53 parts, mineral terpen 7 parts and Solvesso 200 18 parts, together with 120 parts of glass beads, and 200 ml glass bottle The mixture was shaken with a paint conditioner manufactured by Red Devil Co. for 1 hour to disintegrate and disperse to obtain a pigment dispersion of the present invention.

This pigment dispersion had good fluidity and a viscosity at 25 ° C. of 810 cps. No pigment separation was observed after storage for 10 days.

Next, a test was carried out in the same manner as in Example 3 except that this pigment dispersion was used. As a result, all of the other white pigments were used, except that color separation was small with white enanel prepared from a non-aqueous dispersion-based acrylic resin. Color separation was observed in the enamel color mixture.

Example 5 Azo red pigment [manufactured by Hoechst; Nova Palm Red F5]
RK] 18 parts, 57 parts of copolymer (A-2), 15 parts of xylene and 10 parts of mineral terpen were weighed together with 120 parts of glass beads in a 200 ml glass bottle and shaken with a paint conditioner manufactured by Red Devil for 1 hour. The resulting mixture was peptized and dispersed to obtain a pigment dispersion of the present invention.

This pigment dispersion had good fluidity and a viscosity at 25 ° C. of 50 cps. No pigment separation was observed after storage for 10 days.

Next, a room temperature drying type alkyd resin [manufactured by Dainippon Ink and Chemicals, Inc .; Beccosol J-535], a non-aqueous dispersion type acrylic resin [Dainippon Ink and Chemicals, Inc.]
Acrydic A-186], alkyd-modified acrylic resin [Dainippon Ink & Chemicals, Ltd .; Acrydic A-169] or nitrified cotton lacquer [nitrified cotton (Asahi Kasei Kogyo; HIG1 / 2)] Palm oil-modified alkyd resin (manufactured by Dainippon Ink and Chemicals, Inc .; Veccosol J524-1M-60)
Mixture of 40/40/20 (solids weight ratio) of rosin and solubilizer (dibutyl phthalate)] as a vehicle (clear resin weight ratio of resin solids / thinner = 40/60) 2
0 parts were taken, 5 parts of each of the pigment dispersions prepared above was added, and the mixture was uniformly mixed and stirred with a spatula to obtain a mixed enamel. Each mixed enamel was applied on art paper with a 150 micron doctor blade and allowed to air dry. As a result, the gloss was good in any of the mixed enamels, and the specular gloss reflectance (60 ° -60 °) was 85 or more.

Comparative Example 3 Azo-based red pigment [manufactured by Hoechst; Nova Palm Red F5
RK], 18 parts, 57 parts of copolymer (B-2), 15 parts of xylene and 10 parts of mineral terpen were weighed together with 120 parts of glass beads in a 200 ml glass bottle, and shaken with a paint conditioner manufactured by Red Devil for 1 hour. The resulting mixture was peptized and dispersed to obtain a pigment dispersion of the present invention.

This pigment dispersion had good fluidity and a viscosity at 25 ° C. of 1,050 cps. However, separation of the pigment was observed after storage for 10 days.

Next, a test was carried out in the same manner as in Example 5 except that this pigment dispersion was used. As a result, a glossy coating film was obtained with respect to the alkyd-modified acrylic, but with respect to other enamels, the gloss was significantly reduced. .

[Effect of the Invention] In the pigment dispersion of the present invention thus obtained, the pigment is dispersed very uniformly and finely, and the pigment particles hardly aggregate or settle even when stored for a long time.

Thus, the pigment dispersion of the present invention is not limited to vehicle polymers for paints or inks using an aromatic organic solvent as a diluent or solvent, but also non-aqueous dispersion type acrylic resins, terpene soluble acrylic resins, alkyds Resins, fatty acid-modified epoxy resins, chlorinated rubber resins, etc., have good compatibility with coating or ink vehicle polymers using aliphatic organic solvents as diluents or solvents, and there are no restrictions due to these vehicle polymers. Printing inks and paints (clear and white paints) consisting of any vehicle polymer
It can be widely used for coloring.

Claims (3)

(57) [Claims] 1. A pigment, an organic solvent, and a copolymer for a dispersant, wherein the dispersant is an isobornyl ester of an α, β-unsaturated carboxylic acid and an α, β-unsaturated carboxylic acid. Acid as an essential monomer component and isobornyl ester of an α, β-unsaturated carboxylic acid in the monomer component
It is a copolymer having a weight-average molecular weight of 1,000 to 50,000 including a weight percentage of pigment / organic solvent / dispersant (10-70) /
(5 to 70) / (5 to 80). 2. The pigment dispersion according to claim 1, wherein the organic solvent is a mixed solvent of an aromatic organic solvent and an aliphatic organic solvent. 3. A paint comprising the pigment dispersion according to claim 1 and a vehicle polymer for paint containing an aliphatic organic solvent as a diluent or solvent.