JP2008031286A - Toning method for powder coating material and powder coating material for full color - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a toning method for a powder coating material forming a coating film having an approximately uniform color distribution with no defects such as segregation of color, ununiform feeling and shade, and a powder coating material for full color. <P>SOLUTION: In the toning method for the powder coating material, a plurality of colors of powder coating materials having a predetermined color and a pigment processed article are formulated at a desired ratio, and the desired color is prepared by a dry blend using a mixing apparatus. As the powder coating material, a yellow (Y) powder coating, a magenta (M) powder coating and a cyan (C) powder coating are used, and as the pigment processed article, a magenta pigment processed article in which a magenta pigment is mixed with aluminum oxide or silica and a cyan pigment processed article in which a cyan pigment is mixed with aluminum oxide or silica are used. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a toning method for blending a plurality of powder paints and toning and a powder paint for full color.

  Powder coating is spreading in the field of home appliances and the like because it is coated with air as a medium without using a solvent and has high safety and little influence on the environment. Powder coatings used for powder coating are generally manufactured by blending a colorant or other additives in the binder resin that is the basis of the powder, melt-kneading, pulverizing, and classifying. . The powder coating material thus manufactured is charged to a certain polarity by friction, corona discharge or the like, and then electrostatically attached to the surface of the object to be coated. Thereafter, the adhering powder coating is heated and melted. Alternatively, by inserting a preheated article into the powder paint suspended in the air current, and melting and flowing the powder paint on the surface of the article using the preheating. A continuous coating film is formed on the surface of the object to be coated.

  The powder coating is preliminarily adjusted to a predetermined color by adding a colorant adjusted to the target color in the binder resin that is the basis of the powder, and melt-kneading. Manufactured in a state. This manufacturing method is suitable for so-called large lot painting that consumes a large amount of paint of the same color, such as home appliances, but in the case of small lot painting that requires small amounts of multicolor paint, It is not an efficient manufacturing method. In the case of small lots, several types of powder paints toned to a predetermined color are prepared according to the target color and dry blended using a mixing device such as a rotary blade mixer. Therefore, a method for producing a powder coating material having a predetermined color has been studied as an efficient method.

In Patent Document 1, powder coatings of so-called three primary colors of yellow (Y), magenta (M), and cyan (C) and black (K) are used, and predetermined amounts thereof are adhered to an object to be coated. A baking powder coating method is disclosed.
JP 09-262536 A

  However, in the case of the powder coating method described in Patent Document 1, there is a problem that defects such as color segregation, mottledness, and shading occur in the coating film formed by baking. In addition, blending is performed by blending a light-transmitting powder coating that is preliminarily adjusted to the three primary colors of yellow (Y), magenta (M), and cyan (C) according to the target color. In the case where a coating film is formed using a later powder coating material, there is a problem that the formed coating film similarly has defects such as color segregation, mottled feeling, and shading. In particular, when the light yellow (Y) is blended with a small amount of dark cyan (C) or magenta (M), and when magenta (M) is blended with a small amount of cyan (C), the above-mentioned defects are noticeable. Is done.

  Such a case will be described with reference to the color circle diagram of the conventional three-color powder paint of yellow (Y), magenta (M), and cyan (C) shown in FIG. 2. Description of the Related Art Conventionally, when an attempt is made to produce a powder coating having the shaded area shown in FIG. 2 by dry blending, there has been a problem that defects such as color segregation, mottledness, and shading occur particularly in the coating film.

  The object of the present invention has been made in view of the above-mentioned problems, and the object of the present invention is color segregation, mottled feeling, despite dry blending of a plurality of color powder paints, It is an object of the present invention to provide a novel powder coating color-matching method and a full-color powder coating that can form a coating film having a substantially uniform color without defects such as shading.

  The present invention has the following technical configuration, and thereby the above-described problems have been solved. That is, the method for toning a powder coating of the present invention is a method of blending a powder coating having a predetermined color and a pigment-treated product in a desired ratio and forming a desired color by dry blending using a mixing device. A yellow (Y) powder coating, a magenta (M) powder coating, and a cyan (C) powder coating are used as the powder coating, and a magenta pigment is aluminum oxide as the pigment-treated product. Alternatively, a magenta pigment-treated product mixed with silica and a cyan pigment-treated product obtained by mixing a cyan pigment with aluminum oxide or silica are used.

  In the present invention, when the powder paint and the pigment-treated product are blended and a desired color is obtained by dry blending using a mixing device, the total amount of the powder paint and the pigment-treated product is The pigment-treated product is preferably less than 5% by weight.

  The full color powder coating of the present invention comprises a yellow (Y) powder coating, a magenta (M) powder coating and a cyan (C) powder coating, a magenta pigment-treated product in which a magenta pigment is mixed with aluminum oxide or silica, and It is characterized by comprising a powder paint in which a cyan pigment is treated with a cyan pigment mixed with aluminum oxide or silica and a desired color is formed by dry blending with a mixing device.

  According to the toning method of the powder coating material of the present invention, it is possible to form a coating film having a substantially uniform color without defects such as color segregation, mottled feeling, and shading. That is, in the present invention, yellow (Y) powder paint, magenta (M) powder paint, and cyan (C) powder paint are used, and magenta pigment is mixed with aluminum oxide or silica as the pigment-treated product. By using a magenta pigment-treated product and a cyan pigment-treated product obtained by mixing a cyan pigment with aluminum oxide or silica and dry-blending them, it is possible to realize a full-color powder coating. Further, according to the method for toning a powder coating of the present invention, powder coatings of various hues can be produced by dry blending without kneading, and a small variety of full-color powder coatings can be economically produced. Can be manufactured automatically.

The powder coating material used for this invention is demonstrated.
The powder coating used in the present invention contains a binder resin, a colorant, and, if desired, a curing agent and other additives. As the binder resin, polyester resin, epoxy resin, acrylic resin, phenol resin, xylene resin, urea resin, melamine resin, and the like can be used. Appropriate positive chargeability can be obtained by adhering to the surface. Examples of the curing agent include isocyanate, amine, polyamide, acid anhydride, polysulfide, trifluoroboric acid, acid dihydrazide, and imidazole. Examples of other additives include fillers such as barium sulfate, calcium carbonate, aluminum oxide, and calcium silicate, acrylic oligomers, flow agents such as silicone resins, and antifoaming agents.

Next, the colorant used for the powder coating is described.
Examples of yellow (Y) colorants include condensed azo pigments, isoindoline pigments, and benzimidazolone pigments. Among these, the condensed azo pigments include C.I. I. Pigment yellow 93, C.I. I. Pigment yellow 94, and C.I. I. Pigment Yellow 95 and the like. Examples of isoindoline pigments include C.I. I. Pigment yellow 109, C.I. I. Pigment Yellow 110 and the like. Further, benzimidazolone pigments include C.I. I. Pigment yellow 154 and the like. Other examples of yellow colorants other than those described above include inorganic pigments such as yellow iron oxide, ocher, yellow lead, zinc yellow, cadmium yellow, and antimony yellow, and C.I. I. Pigment yellow 1, C.I. I. Pigment yellow 3, C.I. I. Pigment yellow 12, C.I. I. Pigment yellow 13, C.I. I. Pigment yellow 16, C.I. I. Pigment yellow 17, C.I. I. Pigment yellow 55, C.I. I. Pigment yellow 65, C.I. I. Pigment yellow 73, C.I. I. Pigment yellow 74, C.I. I. Pigment yellow 83, C.I. I. Pigment yellow 97, C.I. I. Pigment yellow 98, C.I. I. Pigment yellow 115, C.I. I. Pigment yellow 130, C.I. I. Pigment yellow 133, C.I. I. Pigment yellow 138, C.I. I. Organic pigments such as C.I. Pigment Yellow 169, C.I. I. Solvent Yellow 16, C.I. I. Solvent Yellow 33, C.I. I. Solvent Yellow 56, C.I. I. Solvent Yellow 60, C.I. I. Solvent Yellow 61, C.I. I. Solvent Yellow 162, C.I. I. Acid Yellow 1, C.I. I. And dyes such as Acid Yellow 23. The blending amount of the yellow colorant is 1.0 to 20 with respect to 100 parts by weight of the binder resin so that a clear color can be obtained and the translucency of the powder coating is not lowered. It is set in the range of about parts by weight, preferably 1.5 to 8.0 parts by weight, more preferably 2.5 to 4.0 parts by weight, and particularly preferably 2.5 to 3.5 parts by weight.

  As the magenta (M) colorant, for example, a quinacridone pigment is used. Specific examples of such quinacridone pigments include C.I. I. Pigment Red 122. Examples of other magenta colorants other than those described above include inorganic pigments such as Bengala, cadmium red, red lead, mercury cadmium sulfide, manganese purple, reddish yellow lead, molybdenum orange, and the like. I. Pigment red 3, C.I. I. Pigment red 38, C.I. I. Pigment red 48: 2, C.I. I. Pigment red 49: 1, C.I. I. Pigment red 49: 2, C.I. I. Pigment red 50, C.I. I. Pigment red 57, C.I. I. Pigment red 60, C.I. I. Pigment red 81, C.I. I. Pigment red 90, permanent red FNG, C.I. I. Pigment violet 3, C.I. I. Pigment violet 25, C.I. I. Pigment orange 5, C.I. I. Pigment orange 13, C.I. I. Examples thereof include organic pigments such as CI Pigment Orange 16, and dyes such as Spiron Red, Indanthrene Brilliant Orange RK and Indanthrene Brilliant Orange GK. In the case of a magenta (M) powder coating, the amount of the magenta colorant is 100 parts by weight of the binder resin considering that a clear color can be obtained and the translucency of the powder coating is not lowered. 1.0 to 20 parts by weight, preferably 2.0 to 8.0 parts by weight, more preferably 2.5 to 4.0 parts by weight, and particularly preferably 2.5 to 3.5 parts by weight. Set to range.

  As the cyan (C) colorant, a phthalocyanine pigment is particularly preferably used. Specific examples of such phthalocyanine pigments include copper phthalocyanine pigments such as C.I. I. Pigment blue 15 and derivatives thereof. Examples thereof include chlorinated products thereof and barium salts of sulfonic acids of copper phthalocyanine (CI Pigment Blue 17). Moreover, a metal-free phthalocyanine pigment (CI pigment blue 16) etc. can also be used. Other cyan colorants other than the above include inorganic pigments such as Prussian blue and cobalt blue, C.I. I. Pigment blue 18, C.I. I. Organic pigments such as CI Pigment Blue 16; I. Bat Blue 6, C.I. I. And dyes such as Solvent Blue 70. In the case of cyan (C) powder paint, the blending amount of these cyan colorants is 100 weights of the binder resin considering that a clear color can be obtained and the translucency of the powder paint does not deteriorate. 1.0 to 20 parts by weight with respect to parts, preferably 2.0 to 8.0 parts by weight, more preferably 2.5 to 4.0 parts by weight, and particularly preferably 2.5 to 3.5 parts by weight. Is set in the range.

  The powder coating material in the present invention can be obtained by dry-mixing the binder resin and the colorant, kneading and classifying after hot-melt kneading. In addition, it can be prepared by employing a polymerization method such as a suspension polymerization method or an emulsion polymerization method.

  Next, the pigment processed product will be described. The magenta pigment-treated product used in the present invention can be produced by mixing a magenta pigment with aluminum oxide or silica. A cyan pigment treated product can be produced by mixing a cyan pigment with aluminum oxide or silica. As the pigment, the same pigments as those described in the magenta colorant and cyan colorant can be used. The particle size of the pigment to be treated is preferably 1 μm or less.

  The treatment of these pigments (surface treatment) can be carried out by mixing the pigment with aluminum oxide or silica as a surface treatment agent and performing dry mixing by mechanical mixing. Examples of the mixer used for dry mixing include a V-type blender, a cone-type blender, a Nauter mixer, a Henschel mixer, and a super mixer. When using a tribo-charging type coating gun system, aluminum oxide may be used as the surface treatment agent, and when using a corona charging type coating gun system, silica may be used as the surface treatment agent.

  The particle size of aluminum oxide or silica as the surface treatment agent is preferably in the range of 10 to 40 nm. The amount of the surface treatment agent added to the pigment is preferably in the range of 5 to 30 parts by weight with respect to 100 parts by weight of the pigment.

  In the present invention, in addition to yellow (Y) powder coating, magenta (M) powder coating, and cyan (C) powder coating, a total of five hues of magenta pigment-treated product and cyan pigment-treated product are used as primary colors. .

  The present invention will be described with reference to FIG. FIG. 1 is a hue circle diagram of a powder paint and a pigment-treated product used in the toning method of the present invention. In the figure, YYM represents a yellow-red hue, MMC represents a purple hue, and YYC represents a yellow-green hue. As shown in FIG. 1, powder coatings having hues (YYM, MMC, YYC) in the range in which defects such as color segregation, mottledness, and shading have occurred in the coating film (the shaded areas in FIG. 2) , Yellow (Y) powder coating, magenta (M) powder coating, or cyan (C) powder coating is produced by dry blending a magenta pigment-treated product or a cyan pigment-treated product. In addition, powder coatings of other hues can be produced by dry blending appropriately combining yellow (Y) powder coating, magenta (M) powder coating, and cyan (C) powder coating. As a result, it becomes possible to produce powder paints of all hues that do not cause coating film defects by dry blending, and the powder paints can be made full color.

  In the present invention, when the pigment-treated product is mixed with the powder coating and dry blended, the pigment-treated product is less than 5% by weight, preferably less than 1% by weight, more preferably 0.01%, based on the powder coating. It mix | blends so that it may become -0.6weight%. If the blending amount exceeds 5% by weight, the color of the pigment-treated product is too dark, and the coating film has defects such as color segregation, mottled feeling, and shading, so the above range is set.

  The particle diameter of the powder coating material used in the present invention is preferably in the range of a volume average particle diameter of 5 to 20 μm (measured value with Coulter Counter TAII type). Powder particles having a volume average particle diameter of less than 5 μm are not practical as a powder coating because they tend to agglomerate due to an increase in interparticle force due to van der Waals force and the like, and fluidity as a powder deteriorates. . Further, if such small particle size powder particles are to be manufactured by a general melt-kneading and pulverization classification method, a large amount of energy is required in the pulverization classification process, and thus the manufacturing cost is considerably increased. On the other hand, if the volume average particle diameter exceeds 20 μm, a thin and uniform powder adhesion layer cannot be obtained on the surface to be coated, and therefore a good thin film cannot be obtained.

  In the toning method of the present invention, the powder paint obtained by the above method and the pigment-treated product are blended at a desired ratio, and a desired color is toned by dry blending using a mixing apparatus. The blending method is not particularly limited. A dry mixing method using a high speed mixer such as a Henschel mixer or a super mixer can be employed.

[Examples and Comparative Examples]
Next, the toning method of the present invention will be described in more detail using examples and comparative examples. In addition, the following "part" means a weight part.

1) Preparation of powder coating material for each color (1) Yellow (Y) powder coating material Polyester resin (manufactured by Iupika Japan: GV-180) 84 parts Curing agent (manufactured by McOter: Alcure 4000) 16 parts Flowing agent ( 1 part antifoaming agent (manufactured by Midori Chemical Co., Ltd .: benzoin) 1 part yellow pigment (manufactured by Clariant Co., Ltd .: Toner Yellow HG) 3 parts It is melt-kneaded with a pressure kneader under a temperature condition of 110 ° C., and after cooling, coarsely pulverized with a hammer crusher. Thereafter, a powder coating material having a volume average particle diameter of 10 μm was obtained by an air classifier while pulverizing with a jet mill.

(2) Magenta (M) powder paint A volume average particle size of 10 μm was obtained by the same production method as described above except that the yellow pigment was changed to 3 parts of a magenta pigment (manufactured by Dainichi Seika Co., Ltd .: Chromofine Magenta 6878). A powder coating was obtained.

(3) Cyan (C) powder coating A powder having a volume average particle diameter of 10 μm by the same production method as described above except that the yellow pigment is changed to 3 parts of a cyan pigment (manufactured by Dainichi Seika Co., Ltd .: phthalocyanine blue 4920). A body paint was obtained.

2) Preparation of pigment-treated product (1) Magenta pigment-treated product (for tribo)
Magenta pigment (Daiichi Seika Chemicals Co., Ltd .: Chromofine Magenta 6878) 80 parts Aluminum Oxide (Degussa Co .: Alumina C) 20 parts The raw materials having the above blending ratio are mixed with a Henschel mixer, and then passed through a sieve (74 μm). Thus, a magenta pigment-treated product (for tribo) was obtained.

(2) Cyan pigment processed product (for tribo)
Cyan pigment (manufactured by Dainichi Seika Co., Ltd .: Phthalocyanine Blue 4920 80 parts Aluminum oxide (Degussa Co., Ltd .: Alumina C) 20 parts The raw materials having the above blending ratio were mixed with a Henschel mixer, and then passed through a sieve (74 μm). A cyan pigment treated product (for tribo) was obtained.

(3) Magenta pigment treated product (for corona)
Magenta pigment (Daiichi Seika Co., Ltd .: Chromofine Magenta 6878) 80 parts Silica (Degussa Co., Ltd .: Aerosil R972) 20 parts The raw materials having the above blending ratio are mixed in a Henschel mixer, and then passed through a sieve (74 μm). Thus, a magenta pigment-treated product (for corona) was obtained.

3) Toning

Yellowish red The yellow (Y) powder coating was added so that the magenta pigment-treated product (for tribo) was 0.2% by weight, and dry blended with a Henschel mixer.
-Yellowish green A yellow pigment (Y) powder coating was added so that the cyan pigment treated product (for tribo) was 0.2% by weight, and dry blended with a Henschel mixer.
-Purple A cyan (C) powder coating material was added so that the magenta pigment-treated product (for tribo) was 0.2% by weight, and dry blended with a Henschel mixer.

Yellowish red Yellow (Y) powder paint was added so that the magenta pigment-treated product (for corona) was 0.2% by weight, and dry blended with a Henschel mixer.

[Comparative Example 1]
Yellowish red Yellow (Y) powder paint and magenta (M) powder paint were blended at a weight ratio of 75/25 and dry blended.
Yellowish green Yellow (Y) powder paint and cyan (C) powder paint were blended so as to have a weight ratio of 75/25 and dry blended.
Purple A magenta (M) powder paint and a cyan (C) powder paint were blended so as to have a weight ratio of 75/25 and dry blended.

[Comparative Example 2]
Yellowish red A magenta pigment was added to a yellow (Y) powder coating so as to be 0.2% by weight and dry blended.

[Painting]
Each powder coating material of Example 1, Comparative Example 1 and Comparative Example 2 was applied to a white test piece (trade name: PB-137T manufactured by Partec Co., Ltd.) of 0.8 mm × 70 mm × 150 mm with a tribo type powder coating machine, Baking was performed at 180 ° C. for 20 minutes to obtain a coated plate having a coating film. In addition, the film thickness of the coating film was adjusted to be 20 to 30 μm.

  Further, the powder coating material of Example 2 was applied to a white test piece (product name: PB-137T manufactured by Partec Co., Ltd.) of 0.8 mm × 70 mm × 150 mm with a corona type powder coating machine, and baked at 180 ° C. for 20 minutes. A coated plate having a coating film was obtained. In addition, the film thickness of the coating film was adjusted to be 20 to 30 μm.

  When the formed coating film is visually observed, the color segregation, the one without mottled feeling is evaluated as ○ in the color mixing column, the one is evaluated as ×, and the one without density is ○ in the cohesive column. Things were rated as x. Moreover, in the column of comprehensive judgment, the case where the coating film which can endure practical use was evaluated as (circle), and the case of the coating film which cannot be practically used was evaluated as x. The results are shown in Table 1 together with the hue and blending material.

[Evaluation results]
As is clear from the results in Table 1, in Examples 1 and 2, the color mixing property, cohesiveness, and comprehensive judgment were all evaluated as “good”. Further, as is apparent from the results of Examples 1 and 2, in the present invention, a powder coating applicable to both tribo-type powder coating and corona-type powder coating could be used.

  On the other hand, in the case of Comparative Example 1 in which only the powder coating material was dry blended, the color mixing property and the comprehensive judgment were evaluated as x. Moreover, in the case of the comparative example 2 which dry-blended the powder coating material and the pigment which has not been pre-processed, the color mixing property, cohesiveness, and comprehensive determination became evaluation x.

It is a hue ring diagram by the powder coating material and pigment processed product used for the toning method of this invention. FIG. 3 is a hue circle diagram of three color powder coating materials of yellow (Y), magenta (M), and cyan (C).

Claims (3)

  A toning method for a powder coating comprising blending a plurality of color powder paints having a predetermined color and a pigment-treated product in a desired ratio, and toning the desired color by dry blending using a mixing device, A yellow (Y) powder paint, a magenta (M) powder paint, and a cyan (C) powder paint are used as the powder paint, and the magenta pigment obtained by mixing the magenta pigment with aluminum oxide or silica as the pigment-treated product. A toning method for a powder coating, characterized by using a treated product and a cyan pigment treated product obtained by mixing a cyan pigment with aluminum oxide or silica.   When the powder paint and the pigment-treated product are blended and a desired color is obtained by dry blending using a mixing device, the pigment-treated product is used with respect to the total amount of the powder paint and the pigment-treated product. 2. The method for toning a powder coating material according to claim 1, wherein the color mixing method is less than 5% by weight.   Yellow (Y) powder paint, magenta (M) powder paint and cyan (C) powder paint, magenta pigment treated product in which magenta pigment is mixed with aluminum oxide or silica, and cyan pigment are mixed in aluminum oxide or silica A powder coating for full color, comprising a cyan pigment-treated product and a powder coating in which a desired color is formed by dry blending using a mixing device.

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