JP2002012795A - Method of manufacturing modified pearl gray pigment and high brightness coating material using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of manufacturing a modified pearl gray pigment having a sufficient amount of light reflection and a sufficient flip-flop effect (an effect of varying colors depending on the angle to be seen) and used in high brightness coating films with high surface strength. SOLUTION: The method of manufacturing a modified iridescent luster pigment comprises allowing a scaly pearl gray pigment to settle in a mixed solution of a resin and a solvent, separating and setting the settlings, and the powdering the resulting settlings. Further, the high brightness coating material comprises 1.0 pt.wt. modified pearl gray pigment obtained by the above manufacturing method, <=1.0 pt.wt. coating resin, and 1.0-100.0 pts.wt. solvent as the major components.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a modified pearlescent pigment and a glittering paint using the modified pearlescent pigment, and more particularly to a glittering paint having improved glitter and flip-flop effect. .

[0002]

2. Description of the Related Art In recent years, the exterior of automobiles, building materials, stationery, electric appliances, and the like are often coated with a pearlescent pigment-containing paint to obtain a top coat having an optical interference effect.

[0003] However, a conventional resin composition containing a scaly pearlescent pigment gives a glossy feeling when printed or coated, but does not always have good glitter. The reasons are broadly divided into two types: those in which the pigments are not oriented well and irregular light reflection occurs, and those in which the pigments are not exposed on the surface and are thickly covered with resin.

Japanese Patent Application Laid-Open No. 4-126778 discloses that a coating resin, a pearl pigment (pearl luster pigment) and an organic solvent are the main components, and the coating resin (solid content) is based on 100 parts by weight of the pearl pigment. A toning pearl pigment base composition is described which is from 10 to 300 parts by weight.

[0005]

By the way, in order to prevent the irregular reflection of light, which is one of the causes of the decrease in the glitter, the drying conditions and the like may be adjusted.

On the other hand, in order to prevent the pigment from being thickly covered with the resin, the proportion of the resin in the resin composition containing the pearlescent pigment may be reduced as disclosed in JP-A-4-126778 (for example, With such a constitution, the scaly pearlescent pigment is easily peeled off, and there is a problem in practicality from the viewpoint of surface strength.

[0007] The main object of the present invention is to address the above circumstances,
A brilliant paint capable of forming a coating film having a sufficient amount of light reflection, a sufficient flip-flop effect (effect of different colors depending on the viewing angle) and a high surface strength, and a modified pearlescent pigment used therefor It is to provide a manufacturing method of.

[0008]

The structure of the present invention to achieve the above object is as follows.

That is, the present invention comprises a step of sedimenting a scaly pearlescent pigment in a mixture of a resin and a solvent, a step of separating and solidifying the sediment, and a step of pulverizing the sediment after the solidification. And a method for producing a modified pearlescent pigment.

The method for producing a modified pearlescent pigment according to the present invention further has a further feature that "the mixed liquid comprises the resin solid content of 0.3 to 1 with respect to 1 part by weight of the pearlescent pigment.
0.010 parts by weight of the solvent and 5.0 to 100.0 parts by weight of the solvent "and" the washing and drying steps are further provided after the pulverizing step ".

Further, the glittering paint of the present invention comprises a modified pearlescent pigment obtained by the production method of the present invention, a solvent,
Alternatively, the modified pearlescent pigment, a resin for coating, and a solvent are the main components.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The pearlescent pigment used in the present invention is:
A scaly pigment that exhibits pearl luster based on the effect of light interference. Specifically, natural or synthetic mica is the main component, and these surfaces are coated with metal oxides such as titanium dioxide, iron oxide, and tin oxide. Or those coated with various coloring pigments may be mentioned. The particle size of the mica is not particularly limited, but among commercially available mica (particle size: about 1 to 50 μm), those having a small particle size and as flat as possible are preferable because beautiful color tone and pearl luster are easily exhibited.

In the method for producing a modified pearlescent pigment according to the present invention, first, the scaly pearlescent pigment is settled in a mixture of a resin and a solvent (sedimentation step). At this time, it is preferable that the particles are settled so that the particles of the flaky pigment overlap in a layered manner.

The resin used here is generally used for a coating resin, and is not particularly limited. Specific examples include a polyester resin, an acrylic resin, a vinyl chloride resin, a polyurethane resin, a silicone resin, and a phenol resin, and these may be used alone or in combination.

[0015] The solvent used here is generally blended in the paint, and is not particularly limited. Specific examples include aromatic hydrocarbons such as toluene and xylene, esters such as ethyl acetate and butyl acetate, and ketones such as methyl ethyl ketone and methyl ethyl isobutyl ketone. These solvents are preferably used as a mixture of two or more kinds, and the composition thereof is appropriately selected depending on the solubility in the resin, the pigment dispersibility and the like.

Next, the sediment in the sedimentation step is separated and solidified (separation and solidification step). Specifically, for example, after discharging the supernatant in the mixture in which the flaky pigment has settled,
Remove sediment and dry thoroughly.

Next, the sediment after drying and solidification is pulverized (pulverizing step). In this pulverization step, the particle size is 5 to 2
It is preferable to grind to about 5 μm. Also,
Preferably, after this pulverizing step, the resin is further sufficiently separated by ultrasonic cleaning or the like and dried (washing and drying step).

The glittering paint of the present invention contains the modified pearlescent pigment obtained as described above and a solvent, or the modified pearlescent pigment, a coating resin and a solvent as main components. In addition, the same resin and solvent as those described above can be used as the coating resin and the solvent.

As described above, the resin covering the pigment must be reduced as much as possible in order to enhance the glitter of the coating film. On the other hand, the pigment (modified pearlescent pigment) obtained by the production method of the present invention has a form in which a plurality of flaky pigments are adhered to each other by a resin and overlapped in layers, and the surface thereof is covered with a small amount of resin. Has become. For this reason, the glittering paint of the present invention using such a modified pearlescent pigment, even when a small amount of paint resin is mixed with the pigment, the pigment is directly applied to the surface when performing molding, printing, coating or the like. Since it is not exposed and the individual scale-like pearlescent pigments are hard to peel off, there is little problem in terms of surface strength.

Incidentally, depending on the combination of the resin used for producing the modified pearlescent pigment and the solvent used for the glittering paint, a part of the resin to which the modified pearlescent pigment is adhered may be dissolved. In such a case, it is not always necessary to mix the glittering paint with the paint resin.

In the method for producing a modified pearlescent pigment according to the present invention, the mixture used for sedimentation of the flaky pearlescent pigment contains a resin solid content of from 0.3 to 1 part by weight of the pearlescent pigment. It is preferable to use a mixture of 10.0 parts by weight and 5.0 to 100.0 parts by weight of a solvent.

If the amount of this resin is too small, the adhesion of each flaky pigment in the modified pearlescent pigment becomes insufficient and the surface may not be evenly covered with the resin. In the case of a glittering paint mixed in a small amount, a problem may occur in the surface strength of the coating film. On the other hand, if the amount of the resin is too large or the amount of the solvent is too small, the viscosity of the mixed solution (resin composition) is too high to make it difficult to uniformly disperse the flaky pigment, and as a result, the modified pearl obtained is obtained. The uniformity of the gloss pigment tends to decrease, and the time required for the settling step increases, and the production efficiency decreases. Also, if the amount of the solvent is too large and the viscosity of the mixture is too low,
In some cases, the sedimentation speed is too fast, and the flake pigment does not deposit in a layered manner in the sedimentation step.

Further, the glittering paint of the present invention contains 1 part by weight of the above-mentioned modified pearlescent pigment and a resin solid content of 1.
It is preferable to mix 0 to 10 parts by weight of a solvent in an amount of 0 part by weight or less. If the amount of the resin for coating is too large, the resin covering the modified pearlescent pigment in the coating film becomes thicker,
It becomes difficult to obtain the desired glitter. On the other hand, when the amount of the solvent is too small or too large, not only the coating workability is deteriorated, but also a coating film having poor physical properties is not practical.

[0024]

EXAMPLES Examples of the present invention will be described below, but the present invention is not limited to these examples.

(Examples 1 to 7) A scaly pearlescent pigment was uniformly mixed in a mixture of a resin and a solvent to obtain a resin composition. In addition, the flaky pigment has the product name Preveil Red RG
T (manufactured by Shiseido, average particle size: 11 μm), resin used was Byron 200 (manufactured by Toyobo), and the solvent used was a mixture of methyl ethyl ketone and toluene in a ratio of 1: 1. The amounts (parts by weight) of these components are shown in Table 1.

[0026]

[Table 1]

Using the above resin composition, a modified pearlescent pigment was produced as follows.

First, the above resin composition was placed in a flat-bottomed container and left for a long time to settle the flaky pigment. Thereafter, the supernatant was discharged, and the precipitate was taken out and dried sufficiently. Next, the sediment after drying and solidification was crushed using a mortar, the resin was sufficiently separated by ultrasonic cleaning, and dried again.

According to the scanning electron micrograph, each particle of the modified pearlescent pigment obtained as described above has a plurality of flaky pigments adhered by a resin and overlaps in a layered manner. It was about 11 μm. Further, the surface of each particle was covered with a small amount of resin.

Next, 0.3 parts by weight of a coating resin and 3.
1.0 part by weight of the modified pearlescent pigment was uniformly mixed with 7 parts by weight of the mixture to obtain a glittering paint. The same resin and solvent as those used for the resin composition were used for the coating resin and the solvent.

(Examples 8 to 12) The modified pearlescent pigment obtained in Example 2 was uniformly mixed with a mixture of a coating resin and a solvent to obtain a glittering paint. The blending amounts (parts by weight) are shown in Table 2. The same resin and solvent as those used in the previous examples were used for the coating resin and the solvent.

[0032]

[Table 2]

Comparative Example A scaly pearlescent pigment 1.0 in a mixture of 0.3 parts by weight of a coating resin and 3.7 parts by weight of a solvent.
The parts by weight were uniformly mixed to obtain a glittering paint. The same materials as those used in Examples 1 to 7 were used for these materials.

Using the glitter paints prepared in Examples 1 to 12 and Comparative Example, bar coat No. 7 was applied to a film thickness of about 5 μm, and the light reflection amount, flip-flop effect, and surface strength of the coating film were evaluated as follows.
Table 3 shows the evaluation results.

<Light Reflection Amount> Variable Angle Spectrophotometer GCMS-4
(Made by Murakami Color Research Laboratory), fix the incident angle,
The amount of total reflection was compared from the spectral distribution of diffuse reflectance when the light receiving angle of the sample was changed.

<Flip-Flop Effect> Using a variable-angle spectrophotometer GCMS-4 (manufactured by Murakami Color Research Laboratory), the incident angle was fixed and the diffuse reflectance when the light-receiving angle of the sample was changed. From the spectral distribution, the difference between the maximum value and the minimum value of the reflectance was compared. ◎: color tone change large ○: color tone change Medium △: color tone change Small ×: color tone change almost no

<Surface Strength> Evaluation was made as follows using a pencil scratch coating film hardness tester (pencil hardness H, HB / JIS).
◎… OK at H ○… OK at HB △… NG at HB

[0038]

[Table 3]

As shown in Table 3, Example 1 of the present invention
The glitter paints of Nos. 1 to 12 are relatively improved in the glitter and the flip-flop effect as compared with the paints of Comparative Examples, and can form a coating film having excellent surface strength.

[0040]

As described above, according to the method for producing a modified pearlescent pigment of the present invention, a plurality of flaky pigments are layered and adhered by a resin, and the surface thereof has a small amount of resin. To obtain a pigment covered with the pigment. And, in the glitter paint of the present invention using such a pigment, even if the paint resin to be mixed with the paint is small, the pigment is not exposed to the surface when performing molding, printing, coating, etc. The scaly pearly luster pigment is difficult to peel off, so that it is excellent in surface strength.

In addition, the glitter paint of the present invention has a remarkable improvement in glitter and flip-flop effect as compared with a conventional resin composition containing a pearlescent pigment.

 ──────────────────────────────────────────────────続 き Continuing on the front page F term (reference) 4J037 AA08 AA15 AA22 AA26 CB01 CB08 CB10 CC14 CC22 CC24 CC26 CC28 DD10 DD23 EE03 EE28 EE29 EE33 EE35 EE43 FF09 4J038 CD031 CG141 DA041 DD001 DG001 DL032 KA01 JA05 EA01 KA20 NA01 NA19

Claims (5)

[Claims] 1. A method comprising the steps of: setting a scaly pearlescent pigment in a liquid mixture of a resin and a solvent; separating and solidifying the sediment; and pulverizing the solidified sediment. A method for producing a modified pearlescent pigment. 2. The mixed liquid comprises 0.3 to 10.0 parts by weight of the resin solid content with respect to 1 part by weight of the pearlescent pigment.
The method for producing a modified pearlescent pigment according to claim 1, wherein 5.0 to 100.0 parts by weight of the solvent is mixed. 3. The method for producing a modified pearlescent pigment according to claim 1, further comprising a washing and drying step after the pulverizing step. 4. A modified pearlescent pigment obtained by the production method according to any one of claims 1 to 3, and a solvent, or the modified pearlescent pigment, a coating resin, and a solvent. A brilliant paint characterized by the following. 5. A method according to claim 1, wherein 1.0 parts by weight or less of the solid content of the coating resin and 1.0 to 100.0 parts by weight of the solvent are mixed with 1.0 part by weight of the modified pearlescent pigment. The glitter paint according to claim 4, characterized in that: