JPH05105830A - Color matching of colored nacreous pigment - Google Patents

Abstract

PURPOSE:To reduce the main-hour required for performing the color matching of a colored nacreous pigment by simplifying the color matching. CONSTITUTION:A process for performing the color matching of a colored nacreous pigment comprising a transparent or translucent flaky base, a light interference part comprising a TiO2 layer which covers the entire surface of the base, a light absorption part comprising a lower oxide of titanium scattered on the surface of the TiO2 layer and a metallically lustrous part scattered on the surface of the TiO2 layer, wherein the color matching is performed by utilizing the finding that the color tone (Lz, az, bz) in the Lab color space of a pigment mixture prepared by mixing xwt.% pigment X in the colored nacreous pigment, represented by (Lx, ax, bx) with ywt.% pigment Y in the colored nacreous pigment (Ly, ay, by) (x+y=100) satisfies the formula: (Lz, az, bz)=Lx+y(Ly-Lx)/100, ax+y(ay-ax), bx+y(by-bx)/100.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel method for toning a colored pearlescent pigment used as a colorant for paints and cosmetics.

[0002]

2. Description of the Related Art For example, pearlescent mica pigments are known as pigments used for top coatings for automobiles. This pearlescent mica pigment has a structure in which TiO ₂ is coated on the entire surface of mica, and is used for design coating using interference color due to the high refractive index of TiO ₂ .

However, since pearlescent mica pigments have poor hiding power and metallic luster, various improved products have been proposed. For example, Japanese Patent Application Laid-Open No. 57-161055 discloses a pigment having a metal coating layer formed by plating on the entire surface of mica. Further, JP-A-59-126468 and JP-A-60-60163 disclose a pigment in which a low-order titanium oxide layer is formed on the entire surface of mica powder and the entire surface is further coated with a TiO ₂ layer. It is disclosed.

However, the pigment disclosed in Japanese Unexamined Patent Publication (Kokai) No. 57-161055 has an extremely high metallic luster because the entire surface is coated with a plating metal, but no interference color is obtained and the color is not obtained. There is no depth. Also, JP-A-59-126
Although the pigments disclosed in JP-A No. 468 and JP-A No. 60-60163 have interference colors and object colors with a certain level of strength, they have a problem of poor metallic luster and hiding power.

In order to solve the problems of the prior application example, the inventors of the present invention have conducted extensive studies, and have filed a patent application No. 3-5083.
No. 4 proposes a colored pearlescent pigment having a new design effect. This pigment is composed of a transparent or semi-transparent scale-like base material, an optical interference part composed of a TiO ₂ layer coated on the entire surface of the base material, and titanium particles formed in a dotted pattern on the surface of the TiO ₂ layer. It is composed of a light absorption part made of a low-order oxide and a metallic luster part having a metallic luster formed on the surface of the TiO ₂ layer in a scattered manner. And the reflection and scattering effect of the metal, comprising the interferences caused by the TiO ₂ layer, the three optical effect of the colored effect by partial reduction of the TiO ₂ layer has excellent coloring pearlescent.

[0006]

By the way, the above-mentioned colored pearlescent pigment is usually produced in a batch method by using a powder sputtering apparatus having a special structure, as disclosed in JP-A-2-295524. It In such a case, a slight variation occurs in the coating amount of titanium metal, the coating speed, and the like, and the fine structure of the film changes. Therefore, the metallic luster, the intensity of interference color, and the coloring power of low-order titanium oxide are variously changed between manufacturing lots. That is, in the case of industrially producing a pigment having such a complex film structure and optical characteristics, it is quite difficult at present to manage the variation in color tone between production lots to a constant level.

Therefore, it is conceivable to adjust the reference color for each manufacturing lot. However, since this colored pearlescent pigment has a completely different mechanism of color development from conventional general organic pigments and inorganic pigments, it is impossible to perform strict color matching using general organic pigments and inorganic pigments. Therefore, it is necessary to adjust the color using another colored pearlescent pigment having a different color tone. However, in the case of pigment toning, it is generally difficult to determine the color tone only with the pigment, so it is necessary to determine the color tone after dispersing the pigment in a vehicle such as a resin liquid. The toning work is a complicated work that requires a lot of trial and error by skilled persons, and there is a problem in that a large number of man-hours are required.

The present invention has been made in view of the above circumstances, and simplifies the color matching operation of colored pearlescent pigments,
The purpose is to reduce man-hours.

[0009]

The method of toning according to the present invention for solving the above-mentioned problems is based on optical interference consisting of a transparent or semi-transparent scale-like base material and a TiO ₂ layer coated on the entire surface of the base material. and parts, and a light absorbing portion made of low order oxides of titanium which are formed on the unevenness distribution on the surface of the TiO ₂ layer, a metallic luster portion having metallic luster formed in a scattered point-like manner on the surface of the TiO ₂ layer A method for toning a colored pearlescent pigment, comprising: (Lx, ax, bx) x weight% of the pigment X of the colored pearlescent pigment represented by (Lx, ax, bx) and (Ly, ay, The color tone (Lz, az, bz) of the mixed pigment Z obtained by mixing y% by weight (x + y = 100) of the pigment Y of the colored pearlescent pigment represented by
A method for adjusting the color of a colored pearlescent pigment, characterized in that the color is adjusted by following the formula. (Lz, az, bz) = {Lx + y (Ly-Lx) / 100, ax + y (ay-ax) / 100, bx + y (by-bx) / 100} (1) First, The colored pearlescent pigment to which the toning method is applied will be described.

The base material forms the base material of the pigment, and transparent or semitransparent scale-like materials such as mica, glass foil, molybdenum disulfide and MIO are used. Mica that naturally occurs as scale-like crystals is particularly preferable, and natural mica such as muscovite, biotite, phlogopite and synthetic mica can be used. Usually, a scale-like material having a ratio of (thickness / length) of (1 to 5) / 100 is used as the base material, the average thickness is about 500 to 1000 Å, and the length of one piece is 3 to 50.
It is about μm.

The TiO ₂ layer is a conventional pearl mica TiO _2.
It is similar to the _two layers and is coated on the entire surface of the substrate. Depending on the thickness of the TiO ₂ layer, interference colors of various color tones can be developed as shown in Table 1.

[0012]

[Table 1] The most important feature of the pigment targeted by the present invention is that it has a light-absorbing portion and a metallic luster portion which are formed on the surface of the TiO ₂ layer in a scattered manner. Here, the light absorbing portion is composed of a low-order oxide of titanium. The low-order oxide of titanium has reflection / absorption characteristics, unlike TiO ₂ which is colorless and transparent. Therefore, it has an object color of blue to brown to black, and various colors are obtained in combination with the interference color of the TiO ₂ layer. This light absorbing portion can be formed by locally reducing the TiO ₂ layer. Further, the lower oxide of titanium may be attached to the surface of the TiO ₂ layer in a scattered manner. As will be described later, it is particularly convenient to form the metallic luster portion at the same time.

The metallic luster portion has metallic luster and is formed by a chemical method such as electroplating or electroless plating, or a physical method such as sputtering, vapor deposition or ion plating, and is made of titanium, zirconium, tungsten, nickel, aluminum, silver, It can be formed in a dotted shape from platinum, gold or the like. For example, when metallic titanium is deposited on the TiO ₂ layer by sputtering, a portion of the TiO ₂ layer is reduced at the same time as the metallic titanium is deposited, and a light absorbing portion made of a lower oxide of titanium is formed at the same time as the metallic luster portion. be able to.

[0014] Light-absorbing portion and the metallic gloss portion, the total projected area on that TiO ₂ layers with respect to the total surface area of the TiO ₂ layer 0.
It is desirable to form it in the range of 03 to 98%. If it is less than 0.03%, the hiding power is lowered and almost no metallic luster is observed. On the other hand, when it is more than 98%, the metallic luster feeling becomes strong, and both the interference color and the coloring power due to light absorption become weak. The light absorbing part and the metallic luster part are made of Ti
_They may be formed separately on the O ₂ layer, or may be formed by further stacking a metallic luster portion on the light absorbing portion.

[0015] In the pigment to which the present invention is directed, as shown in FIG. 2, for example, reflected light B reflected at the interface between the reflected light A and the TiO ₂ layer 101 and the substrate 100 is reflected by the TiO ₂ layer 101 surface There was interference and colored interference colors determined by the (refractive index of the TiO ₂ layer thickness × TiO ₂ layer). In addition, the light absorption section 1
In 02, a part of the incident light is absorbed, and the reflected light C develops the object color of the light absorbing portion 102. Furthermore, metallic luster part 10
A metallic luster is obtained by the reflected light D reflected at 3. Therefore, it is possible to obtain a deep and unique colored metallic tone color, which is a combination of the reflected light, the interference light, the absorbed light and the metallic luster.

Here, the hiding power of the pigment generally becomes smaller as more light is transmitted through the pigment. In this pigment, a part of the light F that has passed through the base material is absorbed by the light absorbing portion 102 on the opposite side, so that the amount of light that is transmitted is smaller and the hiding power is improved as compared with the conventional mica pigment. Further, when viewed in a shade, the light absorbing function of the light absorbing portion 102 reduces diffused reflection and produces vivid color, and thus has a large contrast with a front view and exhibits a good flip-flop property.

Further, the reflected light E that has passed through the pigment, is reflected by the base or the surface of another pigment, and is incident on the pigment again and transmitted, is recombined with the reflected light A and the reflected light B to weaken the interference light. However, in the pigment targeted by the present invention, a part of the light that has passed through the base material is absorbed by the light absorbing portion 102 on the opposite side, and also passes through the pigment and is reflected by the base or the surface of another pigment to enter the pigment again. Since a part of the generated light is also absorbed by the light absorbing portion 102, the light amount of the reflected light E is reduced as compared with the conventional pearlescent mica pigment. This prevents the interference light from being weakened, and produces a strong interference color.

Therefore, this pigment is very useful as a top coat paint for automobiles because it gives a metallic luster, strong interference color, and color development by the object color of the light absorbing portion, and has a large hiding power. The inventors of the present invention, as a result of diligent research on the coloring of the above-mentioned colored pearlescent pigment,
This pigment has (1) the basic color is determined by the thickness of the TiO ₂ layer, (2) the shade of the color changes depending on the amount of metallic titanium sputtered, and (3) the same color system with shades of color. In the case of the pigment of No. 3, the line connecting the colorimetric values becomes almost a straight line, and the color tone of the mixed product changes according to the arithmetic mean rule, and the present invention has been completed, and the present invention has been completed.

That is, the greatest feature of the present invention is x weight% of the pigment X of the colored pearlescent pigment represented by (Lx, ax, bx) and (Ly, ay, by) in the Lab type color display method. The color tone (Lz, az, bz) of the mixed pigment Z mixed with y% by weight (x + y = 100) of the pigment Y of the colored pearlescent pigment is adjusted according to the following formula (1). There is a place to color. (Lz, az, bz) = {Lx + y (Ly-Lx) / 100, ax + y (ay-ax) / 100, bx + y (by-bx) / 100} (1) As a color display method, JIS-Z-8
730 and the like can be used. Further, the color measurement can be performed using a known color difference meter or the like.
However, since it is difficult to measure the color of the pigment as it is, it is necessary to measure the color of the pigment dispersed in the vehicle or coated with the vehicle.

[0020]

In the toning method of the present invention, the Lab values of the pigment X and the pigment Y are first measured, and the values are substituted into the equation (1) to determine the mixture amount y of the pigment Y. The Lab value of the mixed pigment Z is calculated. Since this calculated value is in good agreement with the colorimetric value of the mixed pigment Z actually mixed, the color tone can be simulated before the actual mixing. Further, although the equation (1) is a two-component equation, even if there are three or more components, it can be simulated by developing the equation (1).

Incidentally, in the case of ordinary organic pigments or inorganic pigments, such a relationship does not hold, so that the color is adjusted based on the intuition of the color matching operator. Therefore, according to the toning method of the present invention, even if variations in color tone occur between manufacturing lots, the reference color can be toned only by mixing a predetermined amount of dark or light color pigment from the lot. Therefore, it is possible to avoid the complicated color-adjusting work that is often performed by a skilled person, such as trial and error, and to significantly reduce the number of steps. The pigments added during toning are
For example, it can be easily obtained by adjusting the sputtering amount of titanium metal.

[0022]

EXAMPLES The present invention will be specifically described below with reference to examples.
It [Production of Pigment A] FIGS. 1 and 2 show the face targeted by the present invention.
The schematic sectional drawing of a material is shown. This pigment is used as a scaly substrate
All mica 100 and the entire surface of mica 100 are coated and formed.
TiO ₂Layer 101 and TiO₂Scattered on the surface of layer 101
-Shaped light-absorbing part made of low-order oxide of titanium
102 and the light absorbing portion 102 are formed in a dotted pattern on the surface.
Consists of a metallic luster portion 103 made of metallic titanium
Has been done. Hereinafter, a method for producing this pigment will be described. (Production of pearl mica pigment) Mica flakes (diameter 10 to
20 μm, thickness about 0.5 μm) 50 g, ion-exchanged water
It was added to 500 ml and sufficiently stirred to uniformly disperse.
An aqueous solution of titanyl sulfate having a concentration of 40% by weight was added to the obtained dispersion.
Add 158.2 ml, heat with stirring and boil for 6 hours.
I raised it. After cooling, it is filtered, washed with water, and baked at 900 ° C.
Surface is TiO₂Red pearl mica pigment coated with 9
0 g was obtained. (Explanation of powder sputtering apparatus) Next, referring to FIG. 3 and FIG.
Use the powder sputtering device shown in
Metallic titanium was sputtered on the squid pigment.
This powder sputtering apparatus includes a reduced pressure heat treatment chamber 1 and
Rotating barrel type sputtering chamber 2 and fluid jet mill
3 and a powder filter 4.

The reduced-pressure heat treatment chamber 1 is a container that is electrically resistance-heated and communicates with a main exhaust system 6 and an advanced exhaust system 7 via a filter 5. The main exhaust system 6 is a mechanical vacuum pump, and the advanced exhaust system 7 is a combination of a cryosorption pump, a turbo molecular pump or a mechanical booster pump, and a cooling trap. The reduced pressure heat treatment chamber 1 includes a screw feeder 9 and a motor 40 that rotates the screw feeder 9, and is configured to drop the reduced pressure heat treated fine powder 8 into a conduit 10 that feeds the rotary barrel type sputtering chamber 2. There is.

The rotary barrel type sputtering chamber 2 (hereinafter simply referred to as a barrel) is a rotary cylinder having a structure like a ball mill as shown in FIG. 4, one side wall of which serves as a bearing for the shaft which also serves as the conduit 10. Is axially supported via a magnetic seal 30. The other side wall is pivotally supported by the shaft 12 that functions as a rotating shaft via a magnetic seal 30. A sputtering device 50 is held facing the tip of the shaft 12. The attitude is not vertical and has a tilt determined by the position of the powder bed caused by the rotation of the barrel 2 as will be explained later. The sputtering device 50 is operated by a high frequency current supplied from a power source (not shown) supplied through the shaft 12.

The conduit 10 communicates with the reduced pressure heat treatment chamber 1 via a valve 121. The conduit 10 enters the barrel 2 horizontally from one side wall of the barrel 2 and curves downward again to reach near the bottom of the barrel 2. In this case, the curve is not directed vertically downwards, but at the position where a fluidized bed of fine powder is produced by the rotation of the barrel 2. Inside this conduit 10, a pipe 19 is provided which communicates with the main exhaust system 6, the advanced exhaust system 7 and the inert gas supply source 31. Furthermore, the conduit 10 is in communication with a conduit 11 for supplying fine powder to the fluid jet mill 3 via a valve 122.

The barrel 2 is supported by a support roll 13. The support roll 13 is connected to the rotation shaft of the motor 14 via a belt 15 and drives the barrel 2 to rotate by the rotation of the motor 14. The fluid jet mill 3 has a propeller 2 that rotates at high speed by a motor 20.
1 and is configured so that the fine powder conveyed from the conduit 11 collides with the propeller 21. The discharge side of the fluid jet mill 3 communicates with a circulation pipe 23 provided with a valve 22, and the circulation pipe 23 further communicates with the reduced pressure heat treatment chamber 1. And in the lower part of the valve 22 of the circulation pipe 23,
A powder filter 4 with a valve 24 is connected. The powder filter 4 is a trap that communicates with an exhaust system 26 via a cylindrical filter 25. (Formation of light absorbing portion and metallic luster portion) 90 g of the above-described pearl mica pigment is put into the barrel 2 of the powder sputtering apparatus, and the depressurized heat treatment chamber 1 is depressurized to 2 × 10 ⁻⁵ Torr. Then, argon gas is gradually supplied from the pipe 31 to supply the pigment to the fluid jet mill 3, and the propeller 2
1 and then dispersed into primary particles to be collected in the reduced pressure heat treatment chamber 1. Reduced pressure heat treatment chamber 1 to 2 × 10 ^-2 Torr
The pressure was reduced to 100 ° C., and the temperature was raised to 100 ° C. with a heater to dry and degas the collected pigment for 30 minutes.

Next, the pigment was transferred into the barrel 2 previously replaced with argon gas, and while the barrel 2 was rotated at 5 rpm, sputtering with a bipolar magnetron was started under a reduced pressure of 2 × 10 ^-2 Torr. .. The conditions are that the target is metallic titanium, the power is 0.2 kw × 2, the frequency is 13.56 MHz, and the temperature of the pigment is 200 ° C. or lower. And about 0.05% (2.0
Wt%) metallic titanium was coated. This step 6
Repeated times, a total of 12.0 wt% metal titanium was coated.

After completion of coating, argon gas was supplied from the pipe 31 into the barrel 2, and the obtained pigment was collected in the powder filter 4. (Evaluation) The obtained pigment A had a red pearl luster.
Acrylic pigment A is used so that PWC becomes 10%.
25m on black and white hiding test paper mixed with melamine clear paint
It was applied with an il bar coater. And 30 at 140 ° C
The coating film was formed by baking and drying. For this coating film, the color tone on the surface of each of the white background and the black background is measured and the performance (dichromaticity) in which the color tone varies depending on the overall hiding property, the feeling of cloudiness (transparency), the metallic luster, and the viewing angle is observed. It was sensory judged by. The results are shown in FIG. 5 and Table 2, respectively.
From Table 2, it can be seen that this coating film develops a strong interference color, has a metallic luster and is excellent in hiding power. [Production of Pigment B] Pigment B was produced in the same manner as in Example 1 except that the coating amount of metallic titanium by sputtering was 10.0% by weight. Then, the results of making a paint similar to Pigment A and evaluating similarly are shown in FIG. 5 and Table 2. [Production of Pigment C] Pigment C was produced in the same manner as in Example 1 except that the coating amount of metallic titanium by sputtering was 8.0% by weight. Then, the results of making a paint similar to Pigment A and evaluating similarly are shown in FIG. 5 and Table 2. [Production of Pigment D] Pigment D was produced in the same manner as in Example 1 except that the coating amount of metallic titanium by sputtering was 6.0% by weight. Then, the results of making a paint similar to Pigment A and evaluating similarly are shown in FIG. 5 and Table 2. (Example 1) A pigment D is selected as the pigment X, and a pigment A is used as the pigment Y. And 6.7 parts by weight of pigment A and pigment D
3.3 parts by weight were mixed and dispersed in an acrylic / melamine clear paint with a stirrer so that PWC was 10%.
This paint was applied to a black and white hiding test paper with a 25 mil bar coater and baked at 140 ° C. for 30 minutes to form a coating film.

The color tone of each of the white and black backgrounds was measured with a color difference meter and evaluated in the same manner as for pigment A. The results are shown in FIG. 5 and Table 2. By the way, the colorimetric value of pigment X (pigment A) (Lx, a
x, bx) = (27.0,5.3, -0.9) and the colorimetric value of pigment Y (pigment D) (Ly, ay, by) = (30.2,11.1, -1.6), and the amount of each mixture x = 67 weight % And y = 33% by weight, the colorimetric value of the mixed pigment Z can be calculated as follows by substituting the numerical values into the equation (1).

Lz = 27.0 + 33 (30.2-27.0) /100=28.1 az = 5.3 + 33 (11.1-5.3) /100=7.2 bz = -0.9 + 33 (-1.6 + 0.9) /100=-1.1 This calculation As shown in Table 2, it can be seen that the values match the colorimetric values of the actual mixed pigment Z very well. It can also be seen that it is close to the colorimetric value of pigment B. (Example 2) The mixing ratio of the pigment A and the pigment D is 33 by weight.
5 and Table 2 show the results of mixing and making paint in the same manner as in Example 1 except that the pair 67 was used. Similarly, when calculated from the equation (1), Lz = 29.1, az =
Since 9.2 and bz = -1.4, it can be seen that the colorimetric values of the actual mixed pigment Z are in very good agreement. It can also be seen that it is close to the colorimetric value of pigment C. (Comparative Pigment E) Organic pigment "Permanent Red F5"
R ”(manufactured by Dainichiseika Co., Ltd.) was used to make a paint similar to Pigment A, and the results of the same evaluation are shown in FIG. (Comparative Example 1) Comparative pigment E and the above pigment D were mixed in a weight ratio of 6
Same as Example 1 except that the mixture was 7:33. The results are shown in FIG. 6 and Table 2. (Comparative Example 2) Comparative pigment E and the above pigment D were mixed in a weight ratio of 3
The procedure is the same as in Example 1 except that the mixing ratio is 3:67. The results are shown in FIG. 6 and Table 2.

[0031]

[Table 2] That is, the average amount of sputtering calculated by the pigment Z mixed in Examples 1 and 2 is the same as the pigment B and the pigment C, but the color tone measured or calculated is also the pigment B and the pigment C. Shows the same value as. Therefore, you can predict the color tone without actually mixing,
The number of steps required for color matching can be significantly reduced.

When a general organic pigment is used, as shown in FIG.
As is clear from the above, the plot of the colorimetric value is not linear. Therefore, it is difficult to predict the color tone at the time of mixing by using a simple calculation formula, and the number of man-hours for toning is large.
Furthermore, when an organic pigment is used, all of the hiding properties, transparency, metallic luster and dichroism are significantly reduced, and it cannot be used for color matching of colored pearlescent pigments.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view of a pigment that is the subject of the present invention.

FIG. 2 is an explanatory diagram showing an optical action of a pigment which is a target of the present invention.

FIG. 3 is a front view of the powder sputtering apparatus.

FIG. 4 is a side view of the powder sputtering apparatus.

FIG. 5 is a graph showing a relationship between a Ti sputtering amount and a color tone in an example.

FIG. 6 is a graph showing a relationship between a pigment mixing ratio and a color tone of a comparative example.

[Explanation of symbols]

100: Mica (scaly substrate) 101: T
iO ₂ layer (light interference part) 102: low-order oxide of Ti (light absorption part) 103: metallic Ti (metallic luster part)

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroshi Ito 1 Toyota Town, Toyota City, Aichi Prefecture, Toyota Motor Co., Ltd. (72) Inventor Noriyuki Suzuki, 1 Toyota Town, Aichi Prefecture, Toyota Motor Co., Ltd.

Claims (1)

[Claims] 1. A transparent or semitransparent scale-like base material, an optical interference part composed of a TiO ₂ layer formed by coating on the entire surface of the base material, and dot-like formation on the surface of the TiO ₂ layer. A method for adjusting the color of a colored pearlescent pigment, comprising: a light absorbing part made of a low-order oxide of titanium; and a metallic luster part having a metallic luster formed in a scattered manner on the surface of the TiO ₂ layer. Of the pigment X of the colored pearlescent pigment represented by (Lx, ax, bx) and the pigment Y of the colored pearlescent pigment represented by (Ly, ay, by) in the Lab-based color display method. y% by weight (x + y =
100) is used to adjust the color tone (Lz, az, bz) of the mixed pigment Z according to the following formula (1), and a method for adjusting the color of the colored pearlescent pigment is characterized. (Lz, az, bz) = {Lx + y (Ly-Lx) / 100, ax + y (ay-ax) / 100, bx + y (by-bx) / 100} (1)