JPS62195052A - Pigment dispersion - Google Patents

Abstract

PURPOSE:A pigment dispersion, consisting of a pigment, dispersion stabilizer and organic dispersing medium, the dispersion stabilizer being solid fine particles having a specific particle diameter and adsorbed and flocculated on the surface of the pigment with improved dispersion stability without deteriorating film performance, etc., and useful for coating materials. CONSTITUTION:A pigment dispersion obtained by blending (A) a pigment, preferably organic pigment, e.g. phthalocyanine based pigment, etc., with (B) a dispersion stabilizer, preferably non-aqueous dispersion particles having a primary particle diameter of <=1/2, preferably 1/2-1/20 and <=0.1mum based on the particle diameter of the component (A) and adsorbed and flocculated on the surface of the component (A) and (C) an organic dispersing medium, e.g. xylene, etc. The dispersion is produced by a method for blending the components (A) with (B) and dispersing the resultant blend in the component (C). The weight ratio of the components (A) to (B) is preferably 100:2-250 and the ratio of the component (A) is preferably <=80wt% based on the pigment dispersion.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a pigment dispersion, and more particularly to a pigment dispersion with excellent dispersion stability that can prevent co-aggregation of pigments of the same type and different types in organic solvent-based paints.

Conventionally, in quick-solution paints or inks containing pigments, problems such as difficulty in dispersing pigments during production, agglomeration and sedimentation of pigments during storage, resulting in a decrease in the coloring effect of the picture surface, flooding (color separation), and floating ( lifting), loss of gloss,
It is known that undesirable phenomena such as discoloration over time occur. Various improvement methods have been attempted to solve these problems. For example, (1) a method of dispersing pigments using a wetting agent such as a nonionic, anionic, or cationic surfactant, or an aliphatic polycarboxylic acid as an auxiliary agent;
(2) British Patent Nos. 1108261 and 1159252,
and (3) a method of dispersing pigments using an amphiphilic substance in which a material-compatible substance and a medium-compatible substance are combined, as disclosed in 1346298841; There are known methods to reduce this and prevent the occurrence of floating.

However, the above-mentioned known methods have sufficiently improved the above-mentioned drawbacks, but on the contrary, the disadvantages caused by the above-mentioned additives seen in the conventional methods, i.e., secondary adverse effects such as deterioration of coating film performance and coating condition. The reality is that it is unavoidable.

Accordingly, an object of the present invention is to provide a pigment dispersion liquid in which a stable pigment dispersion can be easily obtained without deteriorating the coating performance and coating condition.

Conventionally, in order to improve the dispersion stability of pigments, the main focus has been on adsorbing polymers that have affinity for the pigment and good solubility in vehicles such as dispersion media, and Selection is an important deciding factor. Important factors that determine this include affinity with the pigment (prefecture name), solubility in the vehicle, compatibility with various polymers and additives after being made into a paint, and selectivity of the developed paint. All factors influence the dispersion stability of the pigment.

For example, if the type of solvent or coating resin changes, the polymer adsorbed to the pigment may show a good dissolution state, shrink into a coil shape and lose its ability to prevent pigment aggregation, or the polymer adsorbed to the pigment may The dispersant polymer is desorbed and loses its ability to inhibit pigment aggregation, resulting in insufficient dispersion stabilization. In this way, when using a polymer as a pigment dispersion stabilizer, it is greatly influenced by its interaction with the surrounding composition components, so the selection of the polymer is subject to various conditions and constraints. However, there is a problem in that the applications are often limited.

Therefore, the present inventors have discovered that it is possible to solve the above-mentioned problems that occur when using a polymer as a pigment dispersion stabilizer. As a result of extensive research in order to obtain a highly stable pigment dispersion that does not inhibit pigment dispersion stability, we found that the above-mentioned problems can be resolved by using a specific solid substance as a dispersion stabilizer instead of a polymer. This discovery led to the completion of the present invention.

Thus, according to the present invention, in a pigment dispersion liquid consisting of a pigment, a dispersion stabilizer, and an organic dispersion medium, the dispersion stabilizer is solid fine particles whose primary particle diameter is 1/2 or less of the U pigment particle diameter. A pigment dispersion liquid is provided, which is characterized in that the pigment is adsorbed and aggregated on the surface of the pigment.

Generally, for solid substances such as pigments, the solid-solid interaction is stronger than the solid-liquid interaction, resulting in adsorption.

Strong cohesion. Furthermore, since the interaction force between solids having different particle sizes becomes even stronger, the orthorhombic dispersion obtained in the present invention exhibits excellent dispersion stability. In this way, there are many advantages to adsorbing solids to pigments, and the adsorbed state is highly stable.

In the present invention, the pigment used for stabilization may be any of organic pigments and inorganic pigments commonly used in commercially available paints, paints, plastics, and the like. In particular, organic pigments are suitable pigments because they have a remarkable stabilizing effect.

Organic pigments include natural dye-based pigments, nitroso-based pigments,
Examples include nitro pigments, azo pigments, phthalocyanine pigments, basic dye pigments, and quinacridone red, quinacridone violet, perylene red, perylene scarlet, dioxazine violet, and isoindolinone yellow. The amount of the pigment used as exemplified above is preferably 80% by weight or less of the pigment dispersion, and 80% by weight or less of the pigment dispersion.
If it exceeds % by weight, it may become difficult to handle due to increased viscosity.

The organic dispersion medium used in the present invention can be arbitrarily selected as long as it is a solvent that does not react with the resin in the paint and the applied dispersion stabilizer, and also a solvent that does not affect solubility. For example, aromatic systems such as xylene, toluene, and solvent naphtha, aliphatic systems such as hexane, mineral spirit, and ethylcyclohexane, ethyl acetate, and acetic acid n-
Examples include ester solvents such as butyl and cellosolve acetate.

The dispersion stabilizer used in the present invention is in the form of solid fine particles in the air or in a liquid, and has a primary particle size of 0.1 μm or less, and has good dispersion stability of the dispersion solution by itself. These are particles that exhibit a surface potential (zeta potential) in a solution, and also exhibit cohesion with the target pigment in a mixed fraction system.

Such dispersion stabilizers include, for example, -COOH, -OH, -NH, -NH2, -8O3H on the particle surface.

Non-aqueous dispersion particles with functional groups such as -PO3, colloid particles such as aerosols, TlO2 fine particles, A/-203 fine particles, BaSO4 fine particles, 5i0
2 fine particles, CaCO3 fine particles, Fe2O3 fine particles, etc. Among these, non-aqueous dispersion particles, which are organic ionic fine particles, are preferred because they exhibit strong aggregation properties with pigments. Typical commercially available inorganic solid fine particles are illustrated below.

The pigment dispersion of the present invention contains the solid stabilizing fine particles in an amount of 5 to 250 parts by weight based on 100 parts by weight of the pigment. The mixed piece of pigment and solid fine particles is determined according to the particle size ratio of each, and 1/2 of the pigment particle size.
It is preferable to use fine particles having a particle size of 1/20 to 1/20. For example, organic pigment (particle size 0.3 μm) 100
When applying inorganic solid fine particles (0.03 μ?yL) to parts by weight, 50 to 200 parts by weight is preferable.

The method for producing the pigment dispersion of the present invention includes a method in which a dispersion consisting only of the target pigment and a fine particle colloid solution are strongly mixed together, and a co-dispersion method in which the target pigment and fine particle colloid are mixed and then dispersed. There is a method of manufacturing. When evaluated from the viewpoint of dispersion stabilization efficiency, a production method using a codispersion method is more preferable.

When producing the above dispersion, amino resin, alkyd resin, polyester resin, epoxy resin, acrylic resin,
Known coating resins such as polyvinyl chloride, polyvinyl acetate, polystyrene, polybutadiene, rosin, and ester gum otake fiber aX derivatives can be mixed into the pigment dispersion of the present invention.

Examples of devices used for dispersion include paint shakers, roll mills, colloid mills, ball mills, sand mills, and attritors. In some cases, a fine and stable pigment dispersion can be easily obtained by dispersion alone.

The pigment dispersion of the present invention produced as described above has a characteristic that its dispersion stability is not easily affected by the type of solvent and resin, so even if the dispersion contains resin, it will not be affected. Can be used with paint systems that do not have On the other hand, if a resin that can be applied to a wide range of coating systems is used as the dispersion resin, the resulting -orthorhombic dispersion can be made into a dispersion that can be commonly applied to a wide range of coating systems.

Flooding and 70-ting phenomena can be further suppressed by using a surface tension modifier such as silicone thread in combination with the pigment dispersion of the present invention or the paint enamel produced therefrom.

Next, the present invention will be explained in detail using examples.

"Parts" and "%" in examples are "parts by weight" and "% by weight"
”.

Example 1 In a 225ω mayonnaise bottle, 20 parts of pigment (1), 1 part of NAD (1) with a solid content of 40%, 20 parts of xylene
．． 4 parts and 18 parts of alkyd resin (1) were thoroughly mixed;
Furthermore, 150 parts of hard alumina beads having a diameter of 5 φ were added and dispersed for 1 hour using a Peytosker.

After the dispersion was completed, aminoalkyd resin (1) was added to the dispersion paste in an amount of -20 parts per 100 parts of total resin solid content to form a paint. Similarly, this dispersion paste was also made into a paint using amino alkyd resin (2) to create two types of paint. Furthermore, a mixed paint was created by combining these paints with aminoalkyd white paint, which is currently used industrially.

The evaluation results of the properties of these single color mixed color paints and the condition of the coated surfaces are shown in Table 1 along with the following comparative examples.

Pigment (I) Copper phthalocyanine blue NA manufactured by Ni-Dainichisei Chemical Co., Ltd.
D (1): Manufactured by Kansai Paint Co., Ltd., non-aqueous dispersion; trade name NT-302 Alkyd resin (1): Solid content 65% Coconut oil fatty acid modified alkyd resin Amino alkyd resin (1): Coconut oil fatty acid modified alkyd resin / Melamine resin = 70730 (solid content ratio) Amino alkyd resin (2): Coconut oil fatty acid modified alkyd resin / Oil-free polyester resin / Melamine resin - 35/3
5/30 (Solid content ratio) Comparative Example 1 In the same container as in Example 1, 20 parts of pigment (1), 30.4 parts of Xyrezi and 18 parts of alkyd resin (1) were mixed,
150 parts of hard alumina beads having a diameter of 5Wmφ were processed and dispersed in a paint shaker for 1 hour. After dispersion, amino alkyd resin (υ) was added to the dispersion paste in an amount of 20 parts per 100 parts of total resin solids to form a paint. Similarly, amino alkyd resin (2) was used to form a paint. They also turned these into paints and created a mixture of these paints and white paint.

Table 1 shows the evaluation results of the properties of these single-color and mixed-color paints and the condition of the painted surfaces coated with them.

Comparative Example 2 In the same container as Example 1, 20 parts of pigment (1) and dispersant (
1) 3.4 parts, xylene 28.7 parts and alkyd resin (
1) Mix 18 parts and add 1 hard alumina bead with a diameter of 5 wφ.
50 parts were added and dispersed in a paint shaker for 1 hour.

After the dispersion was completed, aminoalkyd resin (1) was added to the dispersion paste in an amount of 20 parts per 100 parts of the total resin solid content to form a paint. Similarly, amino alkyd resin (
2) was also used to make a paint, and a mixed paint was also created using these paints and a white paint.

Table 1 shows the evaluation results of the properties of these single-color and mixed-color paints and the condition of the painted surfaces coated with them.

Dispersant (1): DDT-102 manufactured by Kansai Paint Co., Ltd. *1:
Viscosity (voids) at shear speed of 490° *2: C
a5son Yield value *3: Color mixing stability by cylinder test with white paint
A system that coagulates is shown as XS. A stable system that does not coagulate is shown as ○.

*4: Measured on a paint film with a pigment weight ratio of white/pigment (1) = 5/1 As described above, the pigment dispersion of the present invention (Example 1) has a Good viscosity and monochromatic gloss,
In particular, there was no dependence on the type of paint, the stability of mixed colors was significantly improved, and the gloss of mixed color coatings was greatly improved.

Example 2 Pigment (2) 15 parts, 30 in a 2250C mayonnaise bottle
After thoroughly mixing 25 parts of % coroiglusilic acid strength (1), 7.1 parts of xylene, and 15.4 parts of alkyd resin (2), 150 parts of diameter 5IIIll@I quality alumina was added and mixed for 1 hour using a paint shaker. and dispersed. After dispersion is complete, add aminoalkyto resin (
1) was added to make a paint. Similarly, amino alkyd resin (2
) were also used to make paints, and a mixture of these paints and white paint was created.

Table 2 shows the properties of these single-color and mixed-color paints and the evaluation results of the condition of the painted surfaces.
: NALCO84S S-258 (manufactured by Nalco, USA) Alkyd resin (2): Cardura modified alkyd resin Comparative Example 3 In the same container as Example 2, 15 parts of pigment (2), 2 parts of xylene
After thoroughly mixing 4.6 parts of alkyd resin (2) and 15.4 parts of alkyd resin (2), 150 parts of hard alumina beads with a diameter of 5+nφ were added and dispersed for 1 hour using a paint shaker. After the dispersion was completed, a paint was prepared in the same manner as in Example 2.

These evaluation results are shown in Table-2.

Comparative Example 4 In the same container as Example 2, 15 parts of pigment (2) and dispersant (2
) 2.5 parts, xylene 22.1 parts and alkyd resin (2
) After thoroughly mixing 15.4 parts of Rumi mold, 1150 parts of a hard mold with a diameter of 5 mφ was added and dispersed for 1 hour using a paint shaker. After the dispersion was completed, a paint was prepared in the same manner as in Example 2. These evaluation results are shown in Table-2.

Dispersant (2): Kansai Paint DDS-531 Example 1
As in the case of , a paint was obtained that showed no dependence on the paint type and showed good dispersion stability.

Example 3 After thoroughly mixing 15 parts of pigment (3), 22.5 parts of fine parita (1), 24.6 parts of xylene, and 15.4 parts of alkyd resin (2) in a 225CC mayonnaise bottle, the diameter was +111!1φ. 150 parts of hard alumina beads were added and dispersed in a paint shaker for 1 hour. After the dispersion was completed, aminoalkyd resin (1) was added to the dispersion paste in an amount of 30 parts per 100 parts of total resin solids to form a paint. Similarly, the amino alkyd resin (2) was also used to form a paint, and a mixed paint was created by combining these paints and white paint.

Table 3 shows the properties of these single-color and mixed-color paints and the evaluation results of the condition of the painted surfaces.

Pigment (3): Quinacridone Red Fine Particle Barita (manufactured by Toyo Soda Co., Ltd.) (1): BF-20, manufactured by Sakai Chemical Co., Ltd. Comparative Example 5 15 parts of pigment (3) in the same container as in Example 3, 2 parts of xylene
After mixing 4.6 parts and 15.4 parts of alkyd resin (2), dispersion was carried out under the same conditions as in Example 3, and the same coating was prepared. These evaluation results are shown in Table-3.

Comparative Example 6 In the same container as Example 3, pigment (3115 parts, dispersant (2)
2.25 parts, xylene 23.75 parts and alkyd resin 1
After mixing 4 parts, dispersion was carried out under the same conditions as in Example 3, and the same coating material was prepared. These evaluation results are shown in Table-3.

As the above evaluation results show, the pigment dispersion prepared using the P+1 type dispersion stabilizer exhibits good dispersion stability not only for the pigment alone but also for the mixed system with the Pigment type pigment. It is clear that it is not easily affected by the paint resin composition used.

Although examples of systems in which the target pigment and the H-type dispersion stabilizer are efficiently compatible have been introduced above, the present invention is not limited to these examples.

Claims (4)

[Claims] (1) In a pigment dispersion liquid consisting of a pigment, a dispersion stabilizer, and an organic dispersion medium, the dispersion stabilizer is solid fine particles whose primary particle size is 1/2 or less of the pigment particle size, and the pigment A pigment dispersion liquid characterized by adsorption and agglomeration on the surface. (2) The pigment dispersion according to claim 1, wherein the solid fine particles are inorganic fine pigment particles, colloid particles, and non-aqueous dispersion particles having a primary particle diameter of 0.1 μm or less. (3) The pigment dispersion according to claim 1, wherein the pigment is an organic pigment. (4) 2 to 25 solid fine particles per 100 parts by weight of pigment
Claims 1 to 3 containing within the range of 0 parts by weight
Pigment dispersion liquid described in Section 1.