JP2524710B2 - Pigment composition - Google Patents

Description

TECHNICAL FIELD The present invention relates to a pigment composition, and more particularly to a pigment composition useful as a non-aqueous paint.

(Prior art and its problems) Conventionally, various organic pigments and inorganic pigments have been used as a coloring material for paints, but only one type of pigment is used to bring out various desired color tones. However, it is rarely used and is often used as a mixed pigment of two or more kinds.

Various pigments have different surface properties in the vehicle, especially different interfacial potentials, depending on their structures, manufacturing conditions, treatment conditions, etc., and various cautions are required for the combination of pigments. If neglected in many cases, coaggregation occurs in the vehicle due to the difference in interfacial potential and the dispersibility of the pigment is reduced, the sharpness and coloring power of the pigment are reduced, and the gloss of the coating film surface is reduced, Further, there arises a problem that it becomes unusable due to a time-dependent thickening phenomenon that fluidity is lowered during storage of the paint.

In addition, it is very common to use an organic pigment and an inorganic pigment together, but due to the difference in the properties of the organic pigment and the inorganic pigment, for example, the affinity for the vehicle, the sedimentation property in the vehicle, etc. A so-called color separation phenomenon, in which the pigment and the inorganic pigment are separated from each other, often occurs.

Furthermore, in paints, various different vehicles are used depending on the application, but few of the same pigments can be used satisfactorily for these various vehicles, and it is necessary to prepare pigments for each vehicle. There's a problem.

Various surface treatment agents for pigments have been proposed as a method for solving such a problem, but with conventional surface treatment agents,
It is not possible to solve the above various problems at the same time,
In particular, with regard to mixed pigments, even if one problem can be solved, another problem arises, and many of them lack versatility.

For example, JP-A-58-215461 discloses the use of an acrylic polymer having a tertiary amino group as a treating agent for pigments. Since the acrylic polymer used in this method is a basic polymer, it is soluble in an acid aqueous solution, but is insoluble in a medium to alkaline aqueous solution, so that the pigment effectively coats the polymer. In order to achieve this, it is necessary to make the polymer in the form of an emulsion during the production of the polymer or the treatment of the pigment, and at this time, the use of a surfactant is indispensable.

Therefore, a surfactant is inevitably mixed in the obtained treated pigment, and when this treated pigment is used in a coating composition, the presence of the surfactant lowers the water resistance of the coating film, resulting in deterioration of the coating film. In addition, there is a problem that it is highly selective with respect to the vehicle and, when a mixed pigment is used, there is almost no effect in preventing color separation.

(Means for Solving Problems) As a result of earnest research to solve the problems of the prior art as described above, the present inventor found that when a specific (meth) acrylic acid-based polymer is used as a treating agent for a pigment. Is a pigment composition for paints having excellent sharpness, tinting strength, color separation prevention property, storage stability, non-selectivity with respect to vehicle, etc. without using any surfactant during the treatment of the pigment. The present invention has been completed by finding that it can be obtained.

That is, the present invention comprises a mixture of two or more kinds of pigments having different surface properties and a (meth) acrylic acid-based polymer, and the (meth) acrylic acid-based polymer has the following formula (I).
100 parts by weight of (meth) acrylic acid ester monomer and 3 to 20 parts by weight of (meth) acrylic acid, and 15
A copolymer composed of less than 0% by weight to 0% by weight of styrene, or a (meth) acrylic acid alkyl ester other than a (meth) acrylic acid-based monomer modified with a mono- or polyalkylene glycol or a derivative thereof. And a pigment composition for non-aqueous paints.

(However, R ₁ in the above formula is H or CH ₃ , X is a C ₂ or more alkylene group which may have a hydroxyl group, and R ₂ and
R ₃ is a hydrogen atom or an alkyl group which may have a hydroxyl group, but is not a hydrogen atom at the same time. ) (Function) Even if a mixture of two or more pigments having different surface properties,
By treatment with a specific treatment agent, when used as a coloring material for non-aqueous paints, good dispersibility, fluidity,
Provided is a pigment composition having long-term storage stability and color separation resistance.

(Preferred Embodiment) Next, the present invention will be described in more detail with reference to preferred embodiments.

The (meth) acrylic acid-based polymers described above, which are used in the present invention and which characterize the present invention mainly (the term refers to both acrylic and methacrylic), have a basic structure in their structure. It is a polymer having both a tertiary amino group and an acidic carboxyl group at the same time, and its main feature is that it is a so-called amphoteric polymer.

By using such an amphoteric polymer as a treating agent for two or more kinds of mixed pigments having different surface properties, various problems of the prior art are solved and the object of the present invention is achieved.

The (meth) acrylic acid-based polymer is obtained by copolymerizing (meth) acrylic acid with the monomer of the formula (I). Such monomers of formula (I) are known per se, and any of the known monomers can be used.
It is an ester compound of acrylic acid and an alkanolamine such as dimethylethanolamine, diethylethanolamine, dipropylethanolamine, dibutylethanolamine, dimethylpropanolamine and dimethylbutanolamine, or a salt thereof or a quaternary ammonium salt.

Further, a (meth) acrylic acid-based monomer modified with a third monomer, for example, styrene, or a mono- or polyalkylene glycol or a derivative thereof (meth).
Other monomers such as alkyl acrylate can also be copolymerized at the same time.

However, in the case of copolymerizing these third monomers, the amount of these third monomers is preferably less than 15% by weight in the total amount of the monomers, and the amount of these third monomers is 15% by weight or more. In that case, the effect peculiar to the present invention decreases, which is not preferable.

Further, the ratio of the (meth) acrylic acid and the monomer of the above formula (I) used is such that the weight ratio of the two is 100% of the monomer of the formula (I).
A suitable range is 3 to 20 parts by weight of (meth) acrylic acid per part by weight. If the amount of (meth) acrylic acid used is too large, the basicity of the polymer will be insufficient, while
If the amount of acrylic acid used is too small, the acidity of the polymer will be insufficient, the solubility and dispersion stability of the polymer in water will be insufficient, and it will be necessary to use a surfactant during the treatment of the mixed pigment. Sharpness, coloring power, storage stability,
It is not preferable because the color separation preventing property, the non-selectivity with respect to the vehicle and the like decrease.

Although the molecular weight of the amphoteric (meth) acrylic acid-based polymer as described above is not particularly limited, it is generally about 1,000 to 200,000.
The degree is suitable. The copolymerization method may be any conventionally known copolymerization method, but a preferred method is an organic solvent which dissolves the monomer and the produced polymer, and an organic solvent which is miscible with water to some extent, for example, an alcohol or an ester. Hydrophilic solvents such as, ketones, ethers, glycols and the like. By using such a hydrophilic organic solvent to obtain a polymerization solution, it can be immediately used as a treatment agent for mixed pigments.

That is, in general, pigments are often produced in an aqueous medium, and since various pigmentation treatments are performed in the aqueous medium, the above solution is added as it is during the production or treatment of such a pigment. Because you can do it. Of course, a solvent other than the above may be used, or the polymer may be once separated and then used.

Furthermore, depending on the polymer, there are cases where the solubility in a solvent or water is insufficient, and in such a case, use another solvent with a large dissolving power, or use an acid or an alkali. Good.

The pigment used in the present invention may be any conventionally known organic or inorganic pigment, and as the organic pigment, for example, phthalocyanine-based, anthraquinone-based, quinacridone-based, azo-based, indigo-based, quinophthalone-based, Any organic pigment such as isoindolinone-based, quinazoline-based, dioxazine-based, anthrone-based, perinone-based, perylene-based, picoline-based can be used, and as the inorganic pigment, titanium oxide-based, iron oxide-based, Iron hydroxide-based, chromium oxide-based, spinel-type baked pigments, lead octoate-based, vermilion chromate-based, dark blue-based, aluminum powder, bronze powder, and the like.Extensive pigments include calcium carbonate-based, barium sulfate-based, and silicon oxide. Any inorganic pigment such as a pigment, an aluminum hydroxide or carbon black can be used.

In the present invention, the above various pigments are not used alone, but are used as a mixed pigment of two or more kinds having different surface properties, and the combination thereof is organic-organic, inorganic-inorganic, organic- Any combination of inorganic and the like may be used, and the mixing ratio of the two is not particularly limited, but generally one pigment in the mixed pigment is at least 0.1% by weight.
Above, preferably 1% by weight or more.

The amount of the (meth) acrylic acid-based polymer added to the mixed pigment is generally about 0.1 to 20 parts by weight of the (meth) acrylic acid-based polymer per 100 parts by weight of the pigment, and the addition amount is 0.1% by weight. If the amount is less than the above range, the effect of the present invention is difficult to obtain. On the other hand, if the amount exceeds 20% by weight, various physical properties of the pigment are rather deteriorated, which is not preferable.

The method for treating the pigment with the (meth) acrylic acid-based polymer may be any method as long as both are uniformly mixed. For example, when the pigment is in the form of lumps or powders, a tumbler or a high-speed rotating mixer is used. While pulverizing or mixing the pigment in a mixer such as, a method of gradually adding the solution of the (meth) acrylic acid-based polymer to uniformly mix,
When the pigment is in the form of an aqueous paste, a method of mixing them and mixing and kneading them uniformly with a roll, a kneader, etc., and in the case of a slurry-like pigment, a method of uniformly mixing them with a mixer such as a Tyzor bar, etc. Further, in the case of an azo pigment, a method in which it is added in advance to the aqueous medium at the time of its production, and two or more kinds of pigments are separately added as described above (meth)
A method of mixing two or more kinds treated with an acrylic acid-based polymer or a method of previously adding the above-mentioned (meth) acrylic acid-based polymer to the vehicle when the pigment is dispersed in the vehicle may be used.

The pigment composition of the present invention obtained as described above may be in the form of paste or slurry, or may be in the form of any of those obtained by filtering, drying and crushing them.

(Example) Next, the present invention will be described more specifically with reference to Examples and Comparative Examples. In the text, “part” or “%” is based on weight unless otherwise specified.

Example 1 6.7 parts of methacrylic acid and 94.3 parts of dimethylaminoethyl methacrylate are added to 230 parts of methyl ethyl ketone and uniformly dispersed.

Of this, 6.3 parts of azobisisobutyronitrile (hereinafter A
IBN) is added as a polymerization initiator, and gradually heated to 65 ° C with stirring. After completing the polymerization at 65 ° C or higher for 5 hours, the mixture is cooled to room temperature. At this time, the copolymer is dissolved in the solvent, and the content of the active ingredient in the solution is
It was 30%.

Next, put 100 parts of CI Pigment Red 5 and 36 100 parts of CI Pigment Orange into a hensyl mixer 20 and sprinkle 7.8 parts of the above copolymer solution evenly over 5 minutes while mixing at high speed. The solvent contained in was volatilized to obtain a pigment composition of the present invention treated with a copolymer.

Example 2 13.2 parts of acrylic acid and 109.7 parts of dimethylaminoethyl methacrylate and 200 parts of methyl ethyl ketone and
Disperse evenly in a mixed solvent of 100 parts of methyl alcohol. After adding 7.4 parts of AIBN, the mixture was gradually heated to the boiling point, and further reacted at the boiling point for 7 hours. The active ingredient in the obtained copolymer solution was 28.5%.

C. 10.5 parts of the above copolymer solution was treated in the same manner as in Example 1.
I. Pigment Red 5 and CI Pigment Orange 36 1:
One part of 200 parts of mixed pigment was processed to obtain the improved pigment composition of the present invention.

Example 3 5.6 parts acrylic acid and 102.7 parts diethylaminoethyl acrylate are added into 230 parts methyl ethyl ketone,
AIBN 6.3 parts was added and polymerization was carried out at 65 ° C. or higher for 5 hours to obtain a copolymer solution containing 31% of the active ingredient.

This copolymer solution was mixed in the same manner as in Example 1 with a 1: 1 mixed pigment of CI Pigment Red 5 and CI Pigment Orange 36 so that the active ingredient content was 1.5% to obtain a pigment composition of the present invention.

Example 4 4.8 parts of styrene, 4.0 parts of methacrylic acid and 109.7 parts of dimethylaminoethyl methacrylate are uniformly dispersed in 200 parts of methyl ethyl ketone, 7.4 parts of AIBN is added, and gradually heated with stirring. Further, the polymerization was completed at 65 ° C. or higher for 5 hours and then cooled to room temperature to obtain a copolymer solution containing 39% of the active ingredient.

This copolymer solution was uniformly mixed in the same manner as in Example 1 with a 1: 1 mixed pigment of CI Pigment Red 5 and CI Pigment Orange 36 so that the amount of the active ingredient was 2%. Got

Example 5 8.4 parts of butyl acrylate, 2.6 parts of methacrylic acid and 70 parts of dimethylaminoethyl methacrylate are dispersed in 128 parts of methyl ethyl ketone, 5 parts of AIBN are added, and 65 parts of
The polymerization was completed at 5 ° C or higher for 5 hours.

The effective component of this copolymer solution was 39%. 10.3 parts of the above copolymer solution was treated in the same manner as in Example 1 to 200 parts of a 1: 1 mixed pigment of CI Pigment Red 5 and CI Pigment Orange 36 to obtain an improved pigment composition of the present invention.

Example 6 Copolymer obtained in Example 1 in a mixed pigment slurry prepared by dispersing 100 parts of CI Pigment Red 5 and 100 parts of CI Pigment Orange 36 in water according to a conventional method using a mixer such as a dissolver. Add 35 parts of solution and add another 30
After mixing for a minute, the mixture was filtered, dried, and ground to obtain a pigment composition of the present invention, which was a mixed pigment treated with a copolymer.

Example 7 In order to evaluate the effects of the pigment compositions obtained in Examples 1 to 6, a paint having the following composition was prepared.

Formulation (1) Pigment 10 parts Alkyd resin varnish (nonvolatile content 60%) 26.4 parts Melamine resin varnish (nonvolatile content 50%) 13.6 parts Thinner (xylene / n-butanol = 8/2) 20 parts Mixing after dispersion Varnish (alkyd / melamine = 7/3 (solid content)) 48.3 parts Blend (2) Pigment 10 parts Oil-free polyester resin varnish (nonvolatile content 60%)
26.4 parts Melamine resin varnish (non-volatile content 50%) 13.6 parts Swazol # 1500 (Maruzen Sekiyu KK) 20 parts Mixed varnish added after dispersion (polyester / melamine = 7/3 (solids)) 48.3 parts The mixture was placed in a container, glass beads were added, and the mixture was dispersed with a paint shaker (manufactured by Red Devil Co.) to prepare a paint.

Comparative Example 1 Using a 1: 1 mixed pigment of CI Pigment Red 5 and CI Pigment Orange 36 before treatment, a paint was prepared according to Example 7 together with the pigment compositions of Examples 1 to 6, and the physical properties were evaluated by the following evaluation methods. Comparative evaluation was performed and the results shown in Table 1 below were obtained.

Evaluation method (1) Fluidity The obtained paint was measured with a B-type viscometer (manufactured by Tokyo Keiki Co., Ltd.) 6,
Measure the viscosity at 12, 30, 60 rpm (Measuring temperature: 25 ± 2
C) Each viscosity value and TI value (η6 / η60) were used for judgment. The judgment was made in three stages: ◯: excellent, Δ: good, and x: inferior.

(2) Vividness The obtained paint has a final paint viscosity of Ford Cup # 4.
Adjust it with a thinner so that it will be 23 seconds, spray it on a tin plate with an air spray gun, then bake it and cure it, and visually and visually measure the incident angle 60 ° gloss and 20 ° gloss to check the sharpness of the coated surface. A comprehensive evaluation was performed. Judgment is ○:
Excellent, Δ: good, ×: inferior.

(3) Dispersion stability Put the obtained coating material in a constant temperature bath at 25 ℃ for 30 days and 50 ℃.
The above-mentioned (1) fluidity and (2) sharpness of the enamel stored under the condition of × 7 days were evaluated. The judgment was made in three stages of ◯: good, Δ: rather good, and x: bad.

(4) Color separation The obtained dark color paint is mixed with the titanium white paint, or titanium white pigment is mixed in advance with the chromatic color pigment, and the chromatic color pigment: titanium white pigment = 1: 20 is mixed. Such a light-colored paint was prepared and evaluated by spraying on a panel, flow coating, and rubbing test.

The judgment was made in three stages of ◯: good, Δ: rather good, and x: bad.

Example 8 10 parts of a mixed pigment obtained by mixing CI pigment violet 19 and CI pigment orange 36 in a ratio of 1: 1, 26.4 parts of an alkyd resin-based varnish (nonvolatile content: 60%), 20 parts of xylol, and the co-weight obtained in Example 1 The pigment composition of the present invention (primary color base enamel) containing a vehicle was prepared by repeatedly kneading together with 1.0 part of the coalesce on a three-roll three times.

30 parts of alkyd resin varnish (60% non-volatile content) and melamine resin varnish (50 non-volatile content) of this primary color base enamel
%) Was thoroughly mixed with 25 parts to prepare a primary color paint.

Comparative Example 2 A primary color paint was obtained in the same manner as in Example 8 except that the (meth) acrylic acid-based polymer was not used. The primary color paint for comparison and the primary color paint of Example 8 were compared and evaluated according to the evaluation method of Comparative Example 1, and the results shown in Table 2 below were obtained.

Example 9 A 1: 1 mixed pigment of CI Pigment Violet 19 and CI Pigment Orange 36 was dispersed and compounded, 1.0 part of the copolymer obtained in Example 5 was added, and the mixture was dispersed according to Formula (2) of Example 7. The prepared pigment composition of the present invention in the form of a primary color paint was prepared.

Comparative Example 3 The primary color paint prepared in the same manner as in Example 9 except that the (meth) acrylic acid-based polymer was not used in Example 9, and the evaluation of the primary color paint obtained in Example 9 and Comparative Example 1 Comparative evaluation was performed according to the method, and the results shown in Table 3 below were obtained.

Example 10 The copolymer solution obtained in Example 3 was uniformly mixed with the mixed pigment having the composition (weight ratio) shown in Table 4 below so that the active ingredient was 3%, and the mixture was mixed according to the method of Example 1. A polymer-treated pigment composition of the invention was obtained.

Comparative Example 4 The pigment composition of the present invention obtained in Example 10 was dispersed and prepared according to the formulation (1) of Example 7 to obtain a primary color paint (A).

Separately, the same mixed pigment as described in Example 10 which has not been treated with the copolymer obtained in Example 3 is similarly made into a paint according to the formulation (2) of Example 7 to obtain a primary color paint (B). It was
The obtained primary color paint (A) corresponds to the corresponding primary color paint (B)
And a comparative evaluation according to the evaluation method of Comparative Example 1,
I got a table.

(Effects) According to the present invention as described above, when the pigment composition of the present invention is used as a coloring material for a non-aqueous paint, it has good dispersibility and fluidity, and it can be stored for a long time. Also, since the dispersed pigments do not aggregate, there is no reduction in coloring power, vividness and the like and storage phenomenon during storage.

Therefore, it is possible to provide a coating film having high sharpness, tinting strength, gloss and the like even when used after being stored for a long period of time.

Further, the pigment composition of the present invention does not cause color separation in the paint even if the mixed pigment is a mixture of an organic pigment having a small specific gravity and an inorganic pigment having a large specific gravity such as titanium oxide. Yes, and has no selectivity for various vehicles, for example, for baking type vehicles such as melamine / alkyd resin, acrylic / melamine resin, etc., as well as for room temperature drying type vehicles such as NC lacquer, NC / polyamide resin, etc. However, similarly, it has high suitability such as good fluidity, dispersibility, and dispersion stability, and gives an excellent gloss coating film.

Furthermore, since the pigment composition of the present invention does not require the use of any surfactant during its production, the presence of these surfactants does not cause the water resistance of the coating film to decrease and various other defects.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Ken Okura 2-23-11 Denenchofu, Ota-ku, Tokyo (56) References JP-A-60-123564 (JP, A)

Claims (4)

(57) [Claims] 1. A mixture of two or more pigments having different surface properties and a (meth) acrylic acid-based polymer, wherein the (meth) acrylic acid-based polymer is a (meth) of the following formula (I):
Modified with 100 parts by weight of an acrylate-based monomer, 3 to 20 parts by weight of (meth) acrylic acid, and less than 15% to 0% by weight of styrene, or a mono- or polyalkylene glycol or its derivative ( A pigment composition for non-aqueous paints, which is a copolymer composed of a (meth) acrylic acid alkyl ester other than a (meth) acrylic acid-based monomer. (However, R ₁ in the above formula is H or CH ₃ , X is a C ₂ or more alkylene group which may have a hydroxyl group, and R ₂ and
R ₃ is a hydrogen atom or an alkyl group which may have a hydroxyl group, but is not a hydrogen atom at the same time. ) 2. A (meth) acrylic acid-based polymer is a pigment 10.
The pigment composition according to claim (1), which is present in an amount of 0.1 to 20% by weight per 0 part by weight. 3. The pigment composition according to claim 1, wherein the two or more pigments are organic pigments and inorganic pigments. 4. The pigment composition according to claim 1, wherein the two or more kinds of pigments are different kinds of organic pigments.