JPH04139276A - Pigment dispersion liquid and paint - Google Patents

Abstract

PURPOSE:To obtain a pigment dispersicon liquid storable over a long period without causing the coagulation and precipitation of pigment particles and having excellent dispersion stability by compounding a pigment, an organic solvent and a dispersing agent consisting of a copolymer of a specific unsaturated carboxylic acid (or its ester containing bicyclo group). CONSTITUTION:The objective dispersion liquid having high fluidity contains (A) a pigment such as titanium dioxide and yellow iron oxide, (B) an organic solvent such as xylene and toluene and (C) a copolymer containing an alpha,beta-unsaturated carboxylic acid ester containing bicyclo group [e.g. isobornyl (meth) acrylate] and an alpha,beta-unsaturated carboxylic acid [e.g. (meth)acrylic acid] as essential components. The amount of the bicyclo group-containing ester in the copolymer is >=60wt.%.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides toluene, xylene, Tsurpez 100 (manufactured by Exxon), Tsurpez 200 (manufactured by Exxon),
When fine powder solids such as inorganic or organic pigments are dispersed in various organic solvents such as mineral turpentine, excellent fluidity, dispersion stability, and easy dispersibility can be imparted to the dispersion system. Dispersants, especially non-aqueous dispersion type acrylic resins (N, A, D), mineral turpentine soluble modified acrylic resins, alkyd resins, fatty acid-modified epoxy resins, chlorinated rubber resins, etc., and aliphatic organic solvents as diluents. Or, it relates to a pigment dispersion using a dispersant that has good compatibility with a paint or ink vehicle polymer used as a solvent, and its scope of application relates to general coating compositions such as printing inks and paints. It is something.

[Prior Art] Generally, organic or inorganic pigments, which are constituent components of color material compositions for various coatings such as printing inks and paints, are composed of fine powders. When fine pigment particles are dispersed in organic liquids containing vehicle polymers, such as in printing inks and paints, the fluidity and storage stability at high pigment concentrations, especially for vehicle polymers using aliphatic organic solvents, can be reduced. , it is difficult to obtain one with excellent dispersion stability, and often causes various problems that seriously affect the manufacturing process and the quality of the obtained product.

For example, in non-aqueous dispersion type acrylic resin,
Disversion destruction occurs during the pigment dispersion process.

Furthermore, in aliphatic organic solvents, it is difficult to adsorb the vehicle polymer onto the pigment surface, and the degree of pigment aggregation is large, so printing inks and paints using such pigment dispersions are
Compared to printing inks and paints that maintain a stable dispersion state, color density, coloring power, and sharpness during color development are inferior, and the painted surface loses smoothness due to unevenness due to coarse aggregates, and gloss is also reduced. This tends to cause the coated objects and printed materials to lose their commercial value.

Various methods have been proposed to solve these problems. For example, (1) a method using a dedicated pigment dispersion vehicle polymer for non-aqueous dispersion type acrylic resin, and (2) a method of using an ester vehicle polymer such as alkyd resin and fatty acid-modified epoxy resin, as described in U.S. Patent No. 3,940,353. A method of dispersing pigments using the disclosed copolymer containing 40 to 60% by weight of isobornyl acrylate as a dispersant, (3) nonionic, anionic, and cationic surfactant Aluha aliphatic polycarboxylic acid (4) JP-A-55112273, British Patent No. 1313745, U.S. Patent No. 42
Urea derivatives disclosed in Publication No. 94620 etc.,
British Patent No. 1445104, Special Publication No. 58-244
Urethane derivatives disclosed in Publication No. 33, JP-A-60-166318, etc., or U.S. Pat.
A method of dispersing pigments using an amide derivative, as disclosed in Japanese Patent No. 17682, is known.

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

[Means for Solving the Problems] As a result of extensive research in order to solve the problems of the above-mentioned conventional techniques, the present inventors dispersed fine powdery solids, especially organic and inorganic pigments, in an organic solvent. In this case, the inventors have discovered that a stable pigment dispersion that solves the above problems can be formed by using a specific modified acrylic polymer as a dispersant, and have completed the present invention.

That is, the present invention comprises a pigment, an organic solvent, a bicyclo group-containing ester of an α,β-unsaturated carboxylic acid, and an α,β-unsaturated carboxylic acid as essential components, and an α,β-unsaturated carboxylic acid. A pigment dispersion comprising a copolymer containing more than 60% by weight of a bicyclo group-containing ester of an acid, and a paint vehicle comprising this pigment dispersion and an aliphatic organic solvent as a diluent or solvent. The object of the present invention is to provide a paint characterized by containing a polymer.

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

Examples of the bicyclo group-containing ester of α,β-unsaturated carboxylic acid used as a dispersant in the present invention include α,β-
Examples include isobornyl esters of unsaturated carboxylic acids, and among them, (meth)acrylic acid isobornyl esters represented by the following formula (1) are particularly preferred.

R (wherein X is -CH, -CH(CH,)- or -C(
CH=)2'' and R each represent a hydrogen atom or a methyl group.) The content of the bicyclo group-containing ester of α,β-unsaturated carboxylic acid in the copolymer used in the present invention is usually more than 60%. In particular, 63 to 80% by weight has good compatibility with vehicle polymers using aliphatic organic solvents as diluents or solvents, and has excellent stability of paints when colored with pigment dispersions. is preferred.

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

The copolymer can be prepared by known polymerization methods. However, in consideration of the use as a pigment dispersion, it is preferable to use a solution polymerization method because it eliminates the need for dissolving the copolymer in a solvent.

When a solution polymerization method is employed, radical polymerization initiators such as azobisisobutyronitrile, benzoyl peroxide, and ditertiary-butyl peroxide can be used as the polymerization initiator.

Examples of polymerization solvents include 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 aromatic solvents are particularly preferred.

The amount used is preferably 60% by weight or less so that the viscosity can be adjusted later.

The copolymer used in the present invention allows a substantially satisfactory pigment dispersion to be obtained even if the molecular weight changes, but there is no risk of deterioration of the physical properties of the coating film, and the viscosity is appropriate, making it easy to adjust the viscosity by dilution. A weight average molecular weight of 1,000 to
A copolymer having a weight average molecular weight of 3.500 to 20,000 is particularly preferred.

The pigments 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 and selenides such as zinc sulfide and cadmium yellow; (4) ferrocyanides; (5) chromates such as zinc and molybdenum red; and 6) sulfates such as precipitated barium sulfate. System; (7
) Carbonate-based materials such as calcium carbonate; (8) Silicate-based materials such as clay and ultramarine; (9) Phosphate-based materials such as manganese violet; (10) Carbon-based materials such as carbon black; (11) Zinc powder, nickel Examples of organic pigments include 1) azo pigments; (2) lake pigments; (3) phthalocyanine pigments; and (4) condensed polycyclic pigments (perylene, quinacridone, etc.). , isoindolinone, dioxazine, etc.).

The weight ratio of pigment/organic solvent/dispersant in the pigment dispersion of the present invention is not particularly technically limited, but is generally (1
0-70)/(5-70)/(5-85).

The preparation of the pigment dispersion of the present invention can be carried out, for example, by mixing together a solution of the pigment, dispersant in an organic solvent, and, if necessary, an additional organic solvent in a suitable dispersing apparatus, and Examples of dispersion equipment that can be used include ball mills, roll mills, homomixer sand mills, attritors, etc., which are commonly used in the paint industry.

Examples of the organic solvent used in the pigment dispersion of the present invention include toluene, xylene, and Tsurpez 100 (Exxon 1).
, Aromatic organic solvents such as Tsurpez 200 (manufactured by Exxon); Aliphatic organic solvents such as Mineral Turben, V, M&P, and Natsuta; Ester solvents such as ethyl acetate, butyl acetate, and cellosolve acetate; Methyl ethyl ketone, methyl Examples include ketone solvents such as isobutyl ketone, which can be used alone or in a mixture of two or more, but a mixture of an aromatic solvent and an aliphatic organic solvent is particularly preferred.

The blending ratio of the pigment dispersion of the present invention to the vehicle polymer depends on the type of pigment in the dispersion, the degree of coloring required, etc., and can be varied within a wide range, and is not particularly limited. It ranges from 0.1 to 100 parts by weight per 100 parts by weight of polymer.

The vehicle polymer used with the pigment dispersion of the present invention to obtain printing inks and paints is not particularly limited, and includes those using aromatic organic solvents as diluents or solvents, non-aqueous dispersion type acrylic resins, and turpentine resins. Any resin that uses an aliphatic organic solvent as a diluent or solvent can be used, such as soluble acrylic resin, alkyd resin, fatty acid-modified epoxy resin, and chlorinated rubber resin.

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

[Example] The present invention will be described in more detail below with reference to Production Examples, Examples, and Comparative Examples. In addition, all parts and percentages in the examples are based on weight.

Production Example 1 28 parts of methyl methacrylate, 8 parts of ethyl acrylate,
1 part of methacrylic acid, 63 parts of inbornyl acrylate,
0.5 parts of azobisisobutyronitrile, 18 parts of xylene.
5 parts and 35.5 parts of Tsurpetz 2000 were reacted for 10 hours in a reactor equipped with a stirrer, a thermometer and a condenser to obtain the copolymer (A-
1) 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 approximately 6,500.

Production Example 2 Methyl methacrylate 15 parts, methacrylic acid 0, 5 parts,
Diethylaminoethyl methacrylate 0.5 parts, inbornyl acrylate 78 parts, ethyl acrylate 6 parts, azobisisobutyronitrile 0.5 parts, bovine siren 18.5 parts
and 35.5 parts of Tsurpetz 2000 were reacted for 12 hours in a reactor equipped with a stirrer, a thermometer and a condenser to obtain the copolymer (A-2) used as a dispersant in the present invention.
) was obtained.

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

Production Example 3 37 parts of methyl methacrylate, 62 parts of 2-ethylhexyl acrylate, 1 part of methacrylic acid, 0.0 parts of azobisisobutyronitrile. 5 parts of xylene, 18.5 parts of xylene, and 35.5 parts of Tsurpetz 200 were reacted for 10 hours in a reactor equipped with a stirrer, a thermometer, and a condenser to obtain a copolymer (B-1) for comparison.

The obtained copolymer (B-1) is colorless and transparent and has a nonvolatile content of 6.
3.8%, viscosity 16 ps (25°C), weight average molecular weight approximately 9,500.

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

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 approximately 7,400.

Example 1 Red iron oxide [manufactured by Toda Kogyo Co., Ltd.; 50 parts of Todacolor 120R, 45 parts of copolymer (A-1) and Tsurupetz 2]
Weighed 5 parts of 00 into a 200 a+Q glass bottle together with 120 parts of glass beads (diameter t, 5 m/m, same hereinafter), and stirred for 1 hour with Red Devil Paint Conditioner to deflocculate and disperse. , a pigment dispersion of the present invention was obtained.

This pigment dispersion exhibited good fluidity and had a viscosity of 950 cps at 25°C. Further, no separation of the pigment was observed even after storage for 10 days.

Next, a non-aqueous dispersion type acrylic resin [manufactured by Dainippon Ink and Chemicals Co., Ltd.; Acridic A-185] was used.
/ Acridic A-18860/40 (solid content weight ratio) mixture], turpentine soluble acrylic resin [manufactured by Dainippon Ink & Chemicals Co., Ltd.; Acridic 54-113:
l or thermosetting alkyd resin [Dainippon Ink and Chemicals (
Manufactured by Becksol 134/Superbe Nokamin G
White enamel prepared using a mixture of 32l-60=70/30 (solid content weight ratio) as a vehicle (titanium oxide/resin solid content/thinner weight ratio = 20/40/4)
0) 20 parts of each were added, 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, lightly rub the applied surface with your finger to observe the state of color separation (color difference between the area rubbed with your finger and the area not rubbed with your finger). did. As a result, no color separation was observed in 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 Isumi Shiki Co., Ltd.; Cyanine Blue 4033], 53 parts of copolymer (A-2), and 25 parts of Tsurupets 20025 were weighed into a 200IIQ glass bottle together with 120 parts of glass peas, The pigment dispersion liquid of the present invention was obtained by shaking for 1 hour using a paint conditioner manufactured by Red Devil Co., Ltd. to peptize and disperse the pigment.

This pigment dispersion exhibited good fluidity and had a viscosity of 650 cps at 25°C. Also, no separation of the pigment was observed even 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, and no color separation was observed, and the gloss of the coating film was also good.

Example 3 18 parts of quinacridone red pigment [manufactured by Dainippon Ink Chemical Co., Ltd.; Fastgen Super Re Nodo YE],
Weighed 50 parts of copolymer (A-1), 5 parts of mineral turpentine, 5 parts of xylene, and 22 parts of Tsurpetz 100 together with 120 parts of glass beads into a 200 n+Q glass bottle, and shaken with Red Devil paint conditioner for 2 hours. This was followed by peptization and dispersion to obtain a pigment dispersion of the present invention.

This pigment dispersion exhibited good fluidity and had a viscosity of 460 cps at 25°C. Further, no separation of the pigment was observed even after storage for 10 days.

Next, drying oil fatty acid ester Epoquin [manufactured by Inu Nippon Ink Kagaku Kogyo Co., Ltd.; after esterification using Epiclon 4050 and soybean oil fatty acid at a ratio of 50150 (solid weight ratio), xylene/mineral turpentine = 171 ( (weight ratio) dissolved in a mixed solvent with a solid content of 50%.

acid value = 8.2], chlorinated rubber resin [manufactured by Asahi Denka Kogyo Co., Ltd.; CR-50 and Hitachi Chemical Co., Ltd.; Phthalkyto 2]
A mixture of 10/25 (solid content weight ratio) of 65-70,
Turpentine soluble acrylic resin [Dainippon Ink & Chemicals Co., Ltd.
White enamel (titanium oxide/resin solid content/thinner weight ratio = 20/ 40/4
0) 20 parts of each were added, 4 parts of each of the pigment dispersions prepared above were added, and the mixture was uniformly mixed and stirred with a spatula.

Each mixed enamel was applied onto art paper with a 100 micron doctor blade, and after 30 seconds a part of the applied surface was rubbed (rubbed with a finger to observe the state of color separation.As a result, for each mixed enamel. No color separation was observed, and the coating film had good gloss.

Example 4 Carbon black [manufactured by Degussa; Special 100] 2
0 parts, copolymer (A-2) 55 parts and Tsurpets 15
0 25 parts with 120 parts of glass peas, 200 parts
(d) It was weighed into a glass bottle and shaken for 1 hour with a paint conditioner manufactured by Red Devil Co., Ltd. to deflocculate and disperse it, to obtain a pigment dispersion of the present invention.

This pigment dispersion exhibited good fluidity and had a viscosity of 300 cps at 25°C. Further, no separation of the pigment was observed even after storage for 10 days.

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

Comparative Example 1 Red iron oxide [manufactured by Toda Kogyo Co., Ltd.; 55 parts of Todacolor 120R, 45 parts of copolymer (B-1) and Tsurupetz 2]
005 parts, together with 120 parts of glass beads, 200 r
Weigh it into an xrQ glass bottle, shake it for 1 hour with Red Devil's paint conditioner to deflocculate it, and
A pigment dispersion liquid for comparison was obtained.

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

Next, a test was conducted in the same manner as in Example 3 except that this pigment dispersion was used, and there was no color separation in all cases, except that there was little color separation in the mixture with white enamel prepared from the alkyd resin. , generation of agglomerated particles was observed.

Comparative Example 2 Phthalocyanine Blue manufactured by Yamaba Shiki Co., Ltd.; Cyanine Blue 4033] 22 parts, copolymer (B-2) 53 parts,
Mineral turpentine 7 parts and Norjipets 200 1
8 parts, together with 120 parts of glass peas, were weighed into a 200 mQ glass bottle, and shaken for 1 hour with a paint conditioner manufactured by Nododevil Co., Ltd. to deflocculate and disperse, to obtain a pigment dispersion for comparison.0 This pigment dispersion The liquid exhibited good fluidity and had a viscosity of 810 cps at 25°C. Further, no separation of the pigment was observed even after storage for 10 days.

Next, a test was conducted in the same manner as in Example 3 except that this pigment dispersion was used, and all other whites were tested, except that white enanel prepared from a non-aqueous dispersion type acrylic resin showed less color separation. Color separation was observed due to the mixing of enamel colors.

Example 5 Azo red pigment [manufactured by Hoechst; Tuba Palm Red F5
Weigh out 18 parts of RK copolymer, 57 parts of copolymer (A-2), 15 parts of xylene, and 10 parts of mineral turpentine together with 120 parts of glass beads into a 200 d glass bottle, and shake for 1 hour with Red Devil paint conditioner. The pigment dispersion of the present invention was obtained by peptizing and dispersing the powder.

This pigment dispersion exhibited good fluidity and had a viscosity of 540 cps at 25°C. Further, no separation of the pigment was observed even after storage for 10 days.

Next, a room temperature drying alkyd resin [manufactured by Dainippon Ink & Chemicals Co., Ltd.; Beccosol J-535], a non-aqueous dispersion type acrylic resin [Dainippon Ink & Chemicals Co., Ltd.]
Acridic A-186], alkyd-modified acrylic resin [Dainippon Ink & Chemicals Co., Ltd.; Acridic A-169], or nitrified cotton lacquer [nitrified cotton (Asahi Kasei Industries, Ltd.; HIGI/2)]. Coconut oil-modified alkyd resin (manufactured by Inu Nippon Ink Chemical Industry Co., Ltd.; Beccosol J52
A clear paint prepared using a 40/40/20 (solid weight ratio) mixture of 4-IM-60) and a solubility agent (dibutyl phthalate) as a vehicle (resin solid content/thinner weight ratio = 40/ 60) Take 20 parts of each, add 5 parts of the pigment dispersion prepared above to each, and uniformly mix and stir with a spatula to obtain a mixed enamel. Each mixed enamel was applied onto art paper with a 150 micron doctor blade and allowed to air dry. As a result, all mixed enamels had good gloss and specular gloss reflectance (60°-60°) of 85 or higher.

Comparative Example 3 Azo red pigment [manufactured by Hoechst; Tsubaba Balm Red F5
RK] 18 parts, copolymer (B-1) 57 parts, xylene 1
5 parts and 10 parts of mineral turpentine, 1 part of glass peas
Weighed into a 200 rnQ glass bottle with 20 parts,
The mixture was shaken for 1 hour using a paint conditioner manufactured by Red Devil Co., Ltd. to deflocculate and disperse it, thereby obtaining a pigment dispersion for comparison.

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

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

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

Therefore, the pigment dispersion of the present invention is not limited to vehicle polymers for paints or inks that use aromatic organic solvents as diluents or solvents, but also non-aqueous dispersion type acrylic resins, turpentine-soluble acrylic resins, and alkyds. It has good compatibility with vehicle polymers for paints or inks that use aliphatic organic solvents as diluents or solvents, such as resins, fatty acid-modified epoxy resins, and chlorinated rubber resins, and there are no limitations caused by these vehicle polymers. It can be widely used for coloring printing inks and paints (clear and white paints) made of any vehicle polymer.

Claims (1)

[Scope of Claims] 1. A pigment, an organic solvent, a bicyclo group-containing ester of an α,β-unsaturated carboxylic acid, and an α,β-unsaturated carboxylic acid as essential components; A pigment dispersion comprising a copolymer containing more than 60% by weight of a bicyclo group-containing ester of a saturated carboxylic acid. 2. The pigment dispersion according to claim 1, wherein the bicyclo group-containing ester of an α,β-unsaturated carboxylic acid is an isobornyl ester of an α,β-unsaturated carboxylic acid. 3. The pigment dispersion according to claim 1 or 2, wherein the copolymer contains 63 to 80% by weight of a bicyclo group-containing ester of an α,β-unsaturated carboxylic acid. 4. The pigment dispersion according to claim 1, 2 or 3, wherein the organic solvent is a mixed solvent of an aromatic organic solvent and an aliphatic organic solvent. 5. A paint comprising the pigment dispersion according to claim 1, 2, 3 or 4 and a paint vehicle polymer using an aliphatic organic solvent as a diluent or solvent.