JP2019189696A - Dry color, resin molding material, molded body and method for producing them, and method for evaluating dry color - Google Patents

Abstract

To provide a dry color capable of obtaining uniform jet-black color, a molding material and a molded body.SOLUTION: A dry color contains a black pigment and a dispersant, and satisfies the following conditions. (Condition) When a resin plate is created by mixing 100 pts.wt. of polypropylene having a melt flow rate 30 g/10 min (JIS K7210:1999) and a density of 0.9 g/cm(JIS K7112:1999) with respect to 1 pt.wt. of the dry color, and injection molding the mixture with the use of a die polished with polishing cloth paper with particle size #800 (JIS R 6001:1998), avalue and bvalue in Labcolor system of the surface of the resin plate satisfy specific conditions.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a dry color, a resin molding material, a molded body, a production method thereof, and a dry color evaluation method.

  Conventionally, as a method of obtaining a colored resin molded body, a dry color in which a pigment is dispersed in a dispersant in advance and a resin that is a material of the resin molded body to be colored are mixed and then molded. Things have been done. Such a dry color is produced by mixing a pigment to be colored and a dispersant together with various additives added as necessary.

  For example, Patent Document 1 discloses a resin composition using a polyolefin resin, a carbon nanotube, and a specific wax. More specifically, it is disclosed that a specific wax is dispersed in a polyolefin resin in a state where the surface of the carbon nanotube is coated, thereby obtaining a jet black tone having a bluish color and a high blackness. .

  On the other hand, in resin molded products that have been subjected to three-dimensional processing, the reflection of light changes due to the difference in angle observed by the user, resulting in a phenomenon in which the user feels the color, impression, aesthetics, etc. As a result, the quality image on the appearance deteriorates and the sense of unity may be impaired. As one of the causes of such a phenomenon, a bronze phenomenon is known.

As a method for evaluating the bronze phenomenon, for example, in Patent Document 2, a multi-angle spectrocolorimeter is used, and the reflection at 550 nm of the base line and 650 nm of the peak top at the light receiving angle having the highest reflectance in the red wavelength region. It is disclosed that the intensity ratio is obtained and the bronze phenomenon can be reduced as the reflection intensity ratio is smaller.
Further, Patent Document 3 uses a three-dimensional variable angle spectrocolorimetry system to irradiate a recorded image with light from a 45 ° direction and to receive light at a 45 ° position in the reverse direction. It is disclosed that the bronze is less conspicuous as the saturation of the regular reflection light is smaller. In this document, the bronze color saturation is C ^* = √ (a ^* ^ 2 + b ^* ^ 2).

JP2013-209494A JP 2011-144271 A JP2013-252698A

In recent years, a higher level of unity has been demanded as the aesthetic sense of users has improved. In particular, in black resin molded products that have been three-dimensionally processed, the color that the user feels as a result of changes in the reflection of light due to unevenness of the resin molded products in addition to the difference in angle observed by the user Since taste, impression, aesthetics, etc. may differ, a jet black tone with a more unified feeling is required.
Therefore, it was not possible to obtain a uniform jet black at a higher level than required by the user simply by suppressing the bronze phenomenon.

As a result of intensive studies, the present inventor has found that satisfying a specific condition in a dry color is effective as a design guideline for solving the above-described problem.
That is, the present inventor, as a cause of different colors, impressions, aesthetics, etc. felt by the user, L ^{* of the} light received by the change in the position of the light source when the fixed resin molding is irradiated with light ^. It was noted that the a ^* value and b ^* value in the a ^* b ^* color system are different. Then, a new design guideline is set for fluctuations in the a ^* value and b ^* value under specific conditions, and the user can hold the resin molded product at any angle by satisfying a certain condition for the a ^* value and the b ^* value. As a result, it became difficult to perceive differences in color, impression, aesthetics, etc., and as a result, it was found for the first time that a uniform jet black at a high level could be obtained, and the present invention was completed.

The present invention provides a dry color that includes a black pigment and a dispersant and satisfies the following conditions.
(conditions)
100 parts by weight of polypropylene having a melt flow rate of 30 g / 10 min (JIS K7210: 1999) and a density of 0.9 g / cm ³ (JIS K7112: 1999) is mixed with 1 part by weight of the dry color to obtain a particle size of # 800 (JIS). R 6001: 1998) When using a mold polished with abrasive cloth, a resin plate was prepared by injection molding.
The a ^* value and b ^* value in the L ^* a ^* b ^* color system on the surface of the resin plate satisfy the following expressions (1) to (4).
D = [(a ^* value ₂₀₋ a ^* value ₄₅ ) ² + (b ^* value ₂₀₋ b ^* value ₄₅ ) ² ] ^1/2 + [(a ^* value ₄₅ −a ^* value ₇₅ ) ² + (b ^* The value ₄₅ -b ^* value ₇₅₎ ^{2] 1/2} + ^{[(a *} value ₇₅ -a ^* value ₁₁₀₎ ² + ^{(b *} value ₇₅ -b ^* value ₁₁₀₎ ^{2] 1/2} (1)
D <4.3 (2)
Δa ^* <2.5 (3)
Δb ^* <3.6 (4)
(In the formula, a ^* value ₂₀ , a ^* value ₄₅ , a ^* value ₇₅ , a ^* value ₁₁₀ , b ^* value ₂₀ , b ^* value ₄₅ , b ^* value ₇₅ , and b ^* value ₁₁₀ are equal to each other in multi-directional illumination. Using a directional light-receiving multi-angle colorimeter, each a ^* value when the perpendicular is 45 °, the light receiving part is 90 °, and the light source is 20 °, 45 °, 75 °, and 110 °, b ^{* Indicates} value.
.Delta.a ^* = (maximum value of the ^{a *} value _20, ^{a *} value _45, ^{a *} value _75, ^{a *} value ₁₁₀₎ - ^{(a *} value _20, ^{a *} value _45, ^{a *} value _75, ^{a *} value ₁₁₀ Minimum value)
Δb ^* = (b ^* value ₂₀ , b ^* value ₄₅ , b ^* value ₇₅ , b ^* value ₁₁₀ maximum value) − (b ^* value ₂₀ , b ^* value ₄₅ , b ^* value ₇₅ , b ^* value ₁₁₀ Minimum value))

  ADVANTAGE OF THE INVENTION According to this invention, the dry color which can obtain the uniform jet black at a high level, a molding material, and a molded object are provided.

  The above-described object and other objects, features, and advantages will become more apparent from the preferred embodiments described below and the accompanying drawings.

It is the figure which showed typically the multi-angle colorimeter which concerns on this embodiment. It is a schematic diagram for demonstrating the evaluation method in an Example.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. “JIS” is an industrial standard established by the competent minister in response to a report from the Japan Industrial Standards Committee based on the Industrial Standardization Act, and is one of Japan's national standards. “# 800” indicates a predetermined particle distribution of fine powder.

  FIG. 1 is a diagram schematically showing a multi-angle illumination unidirectional light-receiving multi-angle colorimeter according to the present embodiment. As shown in FIG. 1, the multi-angle colorimeter 100 includes light sources 210, 220, 230, and 240 and a light receiving unit 300, and multi-directional illumination that irradiates an object from four different directions and receives light in one direction. A one-way light receiving system is used. When the normal line n (perpendicular line) is 45 ° and the light receiving part is 90 °, the light source 210 is 20 °, the light source 220 is 45 °, the light source 230 is 75 °, and the light source 240 is 110 °.

Light emitted from each of the light sources 210, 220, 230, and 240 in order toward the resin plate P is reflected by the surface of the resin plate P, and the reflected light is parallel to a normal angle of 45 °. The light is received by the light receiving unit 300, and the color in the L ^* a ^* b ^* color system is determined (when the normal is 45 °, the position of the light receiving unit 300 is 90 °).

  For example, “CE-741GL” (manufactured by Macbeth) can be used as the multi-angle colorimeter with a multi-directional illumination and one-way light reception.

-Resin plate The resin plate is prepared by mixing 100 parts by weight of polypropylene having a melt flow rate of 30 g / 10 min (JIS K7210: 1999) and a density of 0.9 g / cm ³ (JIS K7112: 1999) with 1 part by weight of the dry color. , And produced by injection molding using a mold polished with abrasive cloth of particle size # 800 (JIS R 6001: 1998).

  The resin plate has a flat surface and preferably has a thickness of 2 to 3 mm.

The L ^* a ^* b ^* color system a ^* value and b ^* value on the surface of the resin plate satisfy the following formulas (1) to (4).
D = [(a ^* value ₂₀₋ a ^* value ₄₅ ) ² + (b ^* value ₂₀₋ b ^* value ₄₅ ) ² ] ^1/2 + [(a ^* value ₄₅ −a ^* value ₇₅ ) ² + (b ^* The value ₄₅ -b ^* value ₇₅₎ ^{2] 1/2} + ^{[(a *} value ₇₅ -a ^* value ₁₁₀₎ ² + ^{(b *} value ₇₅ -b ^* value ₁₁₀₎ ^{2] 1/2} (1)
D <4.3 (2)
Δa ^* <2.5 (3)
Δb ^* <3.6 (4)
(In the formula, a ^* value ₂₀ , a ^* value ₄₅ , a ^* value ₇₅ , a ^* value ₁₁₀ , b ^* value ₂₀ , b ^* value ₄₅ , b ^* value ₇₅ , and b ^* value ₁₁₀ are equal to each other in multi-directional illumination. Using a directional light-receiving multi-angle colorimeter, each a ^* value when the perpendicular is 45 °, the light receiving part is 90 °, and the light source is 20 °, 45 °, 75 °, and 110 °, b ^{* Indicates} value.
.Delta.a ^* = (maximum value of the ^{a *} value _20, ^{a *} value _45, ^{a *} value _75, ^{a *} value ₁₁₀₎ - ^{(a *} value _20, ^{a *} value _45, ^{a *} value _75, ^{a *} value ₁₁₀ Minimum value)
Δb ^* = (b ^* value ₂₀ , b ^* value ₄₅ , b ^* value ₇₅ , b ^* value ₁₁₀ maximum value) − (b ^* value ₂₀ , b ^* value ₄₅ , b ^* value ₇₅ , b ^* value ₁₁₀ Minimum value))

Here, in the conventional bronze phenomenon evaluation method as disclosed in Patent Documents 2 and 3, since the light received when light is irradiated from one direction is evaluated, a three-dimensional resin molding is performed. It was not well suited for assessing the body. Further, the technique disclosed in Patent Document 2 focuses on the reflectance of the red wavelength, and evaluates that the bronze phenomenon is smaller as the reflection intensity ratio is smaller. That is, since only redness for light in one direction is evaluated, a uniform jet black at a high level has not been obtained.
On the other hand, the conditions satisfied by the dry color in the present embodiment reproduce the situation in which the user actually uses the resin molded body by changing the position of the light source in multiple steps. In addition, the condition satisfied by the dry color in the present embodiment focuses on the variation distance of the a ^* value and the b ^* value due to the difference in the position of the light source, and therefore, simply focuses on the Δa ^* value and the Δb ^* value. In addition, differences in color, impression, aesthetics, etc. in the molded body can be reduced, and a high level of jet black can be obtained.

In the equation, D is the total sum when the variation due to the difference in the position of the light source between the a ^* value and the b ^* value is calculated as the distance. That is, a molded body having a uniform jet black can be obtained even if the light source and the user are in all directions, such as when the position where the user observes the resin molded body or when the position of the light source changes. .

  D is less than 4.3, more preferably less than 2.5, and even more preferably less than 1.8 from the viewpoint of obtaining a more uniform jet black.

The difference Δa ^* between the maximum value and the minimum value of the a ^* value is less than 2.5, preferably 2.3 or less, and more preferably 1.9 or less. As a result, a more uniform jet black is obtained.

The a ^* value is preferably in the range of -15 to 15.

The difference Δb ^* between the maximum value and the minimum value of the b ^* value is less than 3.6, preferably 3.4 or less, and more preferably 2.2 or less. As a result, a more uniform jet black is obtained.

The b ^* value is preferably in the range of -15 to 15.

The L ^* value of the resin plate is preferably 35 or less. As a result, a deep black color is obtained. The L ^* value of the resin plate is measured using an integrating sphere spectrophotometer.

  As for the surface of the resin plate, the surface of the metal mold | die grind | polished with the abrasive cloth paper of particle size # 800 (JISR6001: 1998) is transcribe | transferred. A known method may be used as a polishing method for the mold.

In order for the a ^* value and b ^* value on the surface of the resin plate to satisfy the formulas (1) to (4), the present inventor has found that the present invention devises a method different from the conventional method. Specifically, it is important to appropriately combine and adjust the following conditions.
(I) Combination of dispersant and black pigment (ii) Selection of black pigment (iii) Method for producing dry color (iv) Combination of black pigment and other pigment

・ Dry color (black pigment)
The black pigment may be either an inorganic pigment or an organic pigment, such as carbon black, black iron oxide (triiron tetroxide), black titanium oxide, copper manganese black, copper chrome black, and cobalt black. Examples include inorganic pigments, organic pigments such as cyanine black, and aniline black. A black pigment may be used individually by 1 type, and may be used in combination of 2 or more type.

Among black pigments, carbon black is preferable from the viewpoint of obtaining a uniform jet black. Examples of carbon black include channel black, oil furnace black, gas furnace black, thermal black, acetylene black, bone black and the like.
The content of carbon black is preferably 50% by mass or more, more preferably 80% by mass or more, and 95% by mass or more from the viewpoint of obtaining a uniform jet black with respect to the entire black pigment. Is more preferable. The content of carbon black may be 100% by mass with respect to the entire black pigment.

The shape of the black pigment is preferably particulate.
The average primary particle diameter of the black pigment is preferably 5 nm or more from the viewpoint of obtaining a uniform jet black, more preferably 10 nm or more, and from the viewpoint of reducing lightness and obtaining good dispersibility, 5 μm or less. It is preferable that it is 1 micrometer or less.
Further, from the same viewpoint, the average primary particle size of carbon black is preferably 5 nm or more, more preferably 12 nm or more, on the other hand, preferably 1 μm or less, more preferably 500 nm or less. Preferably, it is 100 nm or less.

  The average primary particle diameter of the black pigment is obtained by obtaining a primary particle image of the pigment by observation with a transmission electron microscope (TEM), measuring the particle diameter of each of about 200 to 300 pigment particles, and calculating the average value. It is done.

The specific surface area of carbon black is preferably 10 m ² / g or more, more preferably 20 m ² / g or more, and 100 m ² / g or more from the viewpoint of obtaining a uniform jet black. On the other hand, it is preferably 400 m ² / g or less, more preferably 300 m ² / g or less, from the viewpoint of suppressing aggregation of the black pigment and obtaining a uniform black color.

  The specific surface area of carbon black can be measured according to JIS K6217-2.

  The black pigment may have a surface physically or chemically treated. Thereby, good dispersibility is obtained.

(Dispersant)
The dispersant is used for processing as a dry color into powder or paste. Examples of the dispersant include metal soaps such as calcium stearate, zinc stearate, magnesium stearate, lithium stearate and the like, fatty acid amides such as stearic acid amide, ethylene bisamide, ester wax, polyethylene wax, silane coupling agent. And other dispersants. These may be used individually by 1 type and may mix 2 or more types.
From the viewpoint of obtaining an effectively unified jet black, a metal stearate is preferable, and magnesium stearate is more preferable.

  Ester wax is used to facilitate uniform blending of pigments. The ester wax preferably has a softening temperature of about 100 ° C. or lower. For example, montanic acid wax solid at room temperature, hydrogenated castor oil and the like are preferable, and aliphatic dihydric alcohol of montanic acid and one or more of ethylene glycol, 1,4-butanediol, 1,6-hexanediol and the like It is more preferable that the ester is. Examples of commercially available products include Hoechst's product “Hoechst Wax E”, BASF's product “E Wax BASF”, and the like.

  Polyethylene wax is used to facilitate uniform blending of pigments. The polyethylene wax preferably has a softening point of 115 ° C. or lower. Examples include those obtained by polymerizing ethylene under high temperature and high pressure, those obtained by separating and purifying low molecular weight components of polyethylene polymer, or those obtained by thermally decomposing polyethylene. Those polymerized below are preferred. Further, the obtained polymer may be oxidized or acid-modified. Commercially available products include “High Wax” manufactured by Mitsui Chemicals, “AC” manufactured by Honeywell.

(Other ingredients)
For dry colors, pigments other than black pigments, ester waxes, polyethylene waxes, antioxidants, ultraviolet absorbers, antistatic agents, and other stabilizers, flame retardants, and interfaces are within the range that does not impair the effects of the present invention. Various additives such as an activator may be added.

  As the pigment other than the black pigment, either an inorganic pigment or an organic pigment may be used. For example, phthalocyanine pigments such as phthalocyanine blue and phthalocyanine green: azo pigments such as azo yellow lake, azo lake red, and monoazo yellow: organic pigments such as polycyclic pigments such as quinacridone pigments, perylene pigments, quinophthalone pigments, and anthraquinone pigments; Inorganic pigments such as ultramarine blue, cobalt, petal, titanium oxide, nickel titanium yellow, and chrome titanium yellow may be contained. These pigments can be used alone or in combination of two or more.

These pigments can be used in combination as appropriate according to the primary average particle diameter, specific surface area, a ^* value, b ^* value, L ^* value, etc. of the black pigment, whereby a uniform jet black can be obtained.
Of these, phthalocyanine pigments are preferably used. Moreover, when using 2 or more types, it is preferable to use so that it may become a complementary color relationship. For example, when a red organic pigment is used, a sense of unity can be obtained by combining a green organic pigment.

  The content of the black pigment is preferably 10 to 100% by mass, more preferably 10 to 90% by mass, and more preferably 30 to 30% by mass with respect to the entire pigment from the viewpoint of obtaining an effectively unified jet black. More preferably, it is 90 mass%.

  The content of the entire pigment is preferably 30 parts by weight or more, and more preferably 50 parts by weight or more with respect to 100 parts by weight of the dispersant. As a result, a uniform jet black is obtained. On the other hand, the content of the entire pigment is preferably 100 parts by weight or less, and more preferably 95 parts by weight or less with respect to 100 parts by weight of the dispersant. Thereby, a pigment can be knead | mixed favorably with respect to a dispersing agent.

-Manufacturing method of dry color The dry color in this embodiment is manufactured as follows.
First, for example, a black pigment, other pigments, a dispersant, and other additives as necessary are mixed using a normal mixer such as a high speed mixer, and the black pigment is kneaded into the dispersant at a high concentration. At this time, control is performed so as to satisfy the above-mentioned specific conditions by setting time, mixer rotation speed, preparation amount, etc. according to the primary average particle diameter, specific surface area, and blending amount of the dispersant with the black pigment. can do. Preferably, the mixer rotation speed is 800 rpm, and more preferably, the mixer rotation speed is 1600 rpm.
Next, a dry color is obtained by discharging the mixture of the black pigment and the dispersant from the mixer.

  According to the dry color of this embodiment, unified jet black can be obtained by satisfy | filling the said specific conditions. In addition, in the prior art, particularly when the light source is sunlight, there was a tendency to feel subtle changes in color, texture, impression, aesthetics, etc., but this was reduced by the dry color of this embodiment. it can. In addition, the above-mentioned index of the specific condition may be set according to the primary average particle diameter, specific surface area, blending amount of the dispersant, etc. with respect to the black pigment, time, mixing speed, etc. It is adjusted by the combination. Therefore, the range of pigment selection can be expanded without using a specific pigment.

  In addition, the standard jet black is a resin molded body produced using the dry color of the present embodiment, when the reflection of light changes due to the difference in angle observed by the user, unevenness of the resin molded body, etc. In addition, it is intended to reduce the unevenness such as color, texture, impression, and aesthetics that the user feels through vision, and to feel lofty black. In addition, the standard jet black includes those that reduce reflection of light and give a calm impression by black.

-Dry color evaluation method A dry color evaluation method including a black pigment and a dispersant, and the dry color is evaluated according to whether or not the following conditions are satisfied.
(conditions)
100 parts by weight of polypropylene having a melt flow rate of 30 g / 10 min (JIS K7210: 1999) and a density of 0.9 g / cm ³ (JIS K7112: 1999) is mixed with 1 part by weight of the dry color to obtain a particle size of # 800 (JIS). R 6001: 1998) When using a mold polished with abrasive cloth, a resin plate was prepared by injection molding.
The a ^* value and b ^* value in the L ^* a ^* b ^* color system on the surface of the resin plate satisfy the following expressions (1) to (4).
D = [(a ^* value ₂₀₋ a ^* value ₄₅ ) ² + (b ^* value ₂₀₋ b ^* value ₄₅ ) ² ] ^1/2 + [(a ^* value ₄₅ −a ^* value ₇₅ ) ² + (b ^* The value ₄₅ -b ^* value ₇₅₎ ^{2] 1/2} + ^{[(a *} value ₇₅ -a ^* value ₁₁₀₎ ² + ^{(b *} value ₇₅ -b ^* value ₁₁₀₎ ^{2] 1/2} (1)
D <4.3 (2)
Δa ^* <2.5 (3)
Δb ^* <3.6 (4)
(In the formula, a ^* value ₂₀ , a ^* value ₄₅ , a ^* value ₇₅ , a ^* value ₁₁₀ , b ^* value ₂₀ , b ^* value ₄₅ , b ^* value ₇₅ , and b ^* value ₁₁₀ are equal to each other in multi-directional illumination. Using a directional light-receiving multi-angle colorimeter, each a ^* value when the perpendicular is 45 °, the light receiving part is 90 °, and the light source is 20 °, 45 °, 75 °, and 110 °, b ^{* Indicates} value.
.Delta.a ^* = (maximum value of the ^{a *} value _20, ^{a *} value _45, ^{a *} value _75, ^{a *} value ₁₁₀₎ - ^{(a *} value _20, ^{a *} value _45, ^{a *} value _75, ^{a *} value ₁₁₀ Minimum value)
Δb ^* = (b ^* value ₂₀ , b ^* value ₄₅ , b ^* value ₇₅ , b ^* value ₁₁₀ maximum value) − (b ^* value ₂₀ , b ^* value ₄₅ , b ^* value ₇₅ , b ^* value ₁₁₀ Minimum value))

  Whether or not a uniform jet black can be obtained can be evaluated depending on whether or not the specific condition is satisfied. That is, since evaluation can be performed using a dry color, it is possible to determine in advance whether a uniform jet black can be obtained without actually manufacturing a resin molding material and a molded body.

-Resin molding material A resin molding material contains the dry color mentioned above and resin for dilution.
Moreover, the manufacturing method of a resin molding material includes the process of mixing with the dry color mentioned above, resin for dilution, and the additive as needed. The mixing method is not particularly limited, and a known method can be used.
It is also possible to prepare a pellet by diluting the dry color with a dilution resin, and use the pellet as a resin molding material.

The dilution resin is a main raw material that becomes a material of the molded body, and is used as a resin for diluting the dry color. The dilution resin is not particularly limited. For example, polyolefin resin such as polyethylene and polypropylene, polystyrene resin, acrylonitrile butadiene styrene (ABS) resin, polycarbonate resin, polyamide resin, polyethylene terephthalate resin, polybutylene terephthalate resin, poly Examples thereof include methyl methacrylate resin (PMMA).
These may be used individually by 1 type and may mix 2 or more types.

-Molded object A molded object contains the resin molding material mentioned above.
Moreover, the manufacturing method of a molded object includes the process of injection-molding the said resin molding material with the additive as needed. The injection molding is not particularly limited, and a known method can be used.

  The molded body of the present embodiment is a uniform jet black at a high level. Appearance is important, and it can be used in the fields of electronic / electrical / OA equipment processed into various shapes, furniture, miscellaneous goods, automobile interior parts, and the like. Especially, it is suitable in the use for which a uniform jet black is required.

As mentioned above, although embodiment of this invention was described with reference to drawings, these are the illustrations of this invention, Various structures other than the above are also employable.
For example, a dry color containing a black pigment and a dispersant and satisfying the above conditions can be used together with a dilution resin to produce a resin molding material.

  EXAMPLES Next, although an Example demonstrates this invention in detail, the content of this invention is not restricted to an Example.

(Pigment)
The pigments used in Examples and Comparative Examples are as follows.
Black 7 (product name: MONARCH880: manufacturer Cabot), primary average particle diameter 16 nm, specific surface area 220 m ² / g
・ Green7 (Product name Heliogen Green K8730: manufacturer BASF)
・ Blue15: 1 (Product name Lionol Blue SL: Manufacturer Toyocolor Co., Ltd.)
・ Red122 (Product name Cinquasia Pink K4430FP: manufacturer BASF)
・ Green7 (Product name Heliogen Green K8730: manufacturer BASF)

(Dry color creation)
-Examples 1-4 and Comparative Examples 1-4
A mixture of zinc stearate SZ-2000 (manufactured by Sakai Chemical Industry Co., Ltd.) and calcium stearate SC-100 (manufactured by Sakai Chemical Industry Co., Ltd.) so that the total pigment concentration in the dry color is as shown in Table 1. After mixing with zinc stearate and calcium stearate in the same amount), all pigments were mixed for 10 minutes at a mixer rotation speed of 1100 rpm using a 10 L high speed mixer (Mitsui Miike Chemical Co., Ltd.). A dry color was obtained by discharging the mixture.
The composition of all pigments was as shown in Tables 2 and 3.

(Create resin plate)
First, 100 parts by weight of polypropylene (Novatech PP BC03B, melt flow rate 30 g / 10 min (JIS K7210: 1999), density 0.9 g / cm ³ (JIS K7112: 1999), 1 part by weight of the obtained dry color. Polypro Co., Ltd.) was kneaded with a continuous twin screw extruder, and a resin plate was prepared by injection molding using a mold polished with abrasive cloth paper of particle size # 800 (JIS R 6001: 1998).
The prepared resin plate had a size of 80 × 50 mm and a thickness of 2 mm.

(Measurement)
With respect to the resin plate, using a multi-angle illumination unidirectional light-receiving multi-angle colorimeter (“CE-741GL” (manufactured by Macbeth)), the vertical line is 45 °, the light receiving unit is 90 °, the light source is 20 °, 45 The respective a ^* values and b ^* values when measured at °, 75 °, and 110 ° were measured.
In addition, the difference between the maximum value and the minimum value of the measured a ^* value is Δa ^* , and the difference between the maximum value and the minimum value of the measured b ^* value is Δb ^* .
The results are shown in Tables 2-7.

(Calculation of D)
D was calculated by fitting to the following equation (1). The results are shown in Tables 2-7.
D = [(a ^* value ₂₀₋ a ^* value ₄₅ ) ² + (b ^* value ₂₀₋ b ^* value ₄₅ ) ² ] ^1/2 + [(a ^* value ₄₅ −a ^* value ₇₅ ) ² + (b ^* The value ₄₅ -b ^* value ₇₅₎ ^{2] 1/2} + ^{[(a *} value ₇₅ -a ^* value ₁₁₀₎ ² + ^{(b *} value ₇₅ -b ^* value ₁₁₀₎ ^{2] 1/2} (1)
(In the formula, a ^* value ₂₀ , a ^* value ₄₅ , a ^* value ₇₅ , a ^* value ₁₁₀ , b ^* value ₂₀ , b ^* value ₄₅ , b ^* value ₇₅ , and b ^* value ₁₁₀ are equal to each other in multi-directional illumination. Using a directional light-receiving type multi-angle colorimeter, each a ^* value when the perpendicular is 45 °, the light receiving part is 90 °, and the light source is 20 °, 45 °, 75 °, and 110 °, b ^{* Indicates} value.)

(Evaluation)
Evaluation was performed as follows.
As shown in FIGS. 2 (a) to 2 (d) under a natural light (sunlight) from 10 am to 2 pm outdoors on a sunny day, a normal line n (perpendicular) to the resin plate P is 45. The position of the resin plate P is determined so that the observer is 90 °, the resin plate P is not in the shadow of the observer, and the angle of the resin plate P is changed to 20 °, 45 °, 75 °, and 110 °. The appearance of P was visually observed. As a result of the observation, the unified jet black of the resin plate P was evaluated in four stages of 1-4. The lower the value, the more unified jet black was obtained. The results are shown in Table 9.

100 Multi-angle colorimeter 210 Light source 220 Light source 230 Light source 240 Light source 300 Light receiving part P Resin plate

Claims (14)

A dry color containing a black pigment and a dispersant and satisfying the following conditions.
(conditions)
100 parts by weight of polypropylene having a melt flow rate of 30 g / 10 min (JIS K7210: 1999) and a density of 0.9 g / cm ³ (JIS K7112: 1999) is mixed with 1 part by weight of the dry color to obtain a particle size of # 800 (JIS). R 6001: 1998) When using a mold polished with abrasive cloth, a resin plate was prepared by injection molding.
The a ^* value and b ^* value in the L ^* a ^* b ^* color system on the surface of the resin plate satisfy the following expressions (1) to (4).
D = [(a ^* value ₂₀₋ a ^* value ₄₅ ) ² + (b ^* value ₂₀₋ b ^* value ₄₅ ) ² ] ^1/2 + [(a ^* value ₄₅ −a ^* value ₇₅ ) ² + (b ^* The value ₄₅ -b ^* value ₇₅₎ ^{2] 1/2} + ^{[(a *} value ₇₅ -a ^* value ₁₁₀₎ ² + ^{(b *} value ₇₅ -b ^* value ₁₁₀₎ ^{2] 1/2} (1)
D <4.3 (2)
Δa ^* <2.5 (3)
Δb ^* <3.6 (4)
(In the formula, a ^* value ₂₀ , a ^* value ₄₅ , a ^* value ₇₅ , a ^* value ₁₁₀ , b ^* value ₂₀ , b ^* value ₄₅ , b ^* value ₇₅ , and b ^* value ₁₁₀ are equal to each other in multi-directional illumination. Using a directional light-receiving type multi-angle colorimeter, each a ^* value when the perpendicular is 45 °, the light receiving part is 90 °, and the light source is 20 °, 45 °, 75 °, and 110 °, b ^{* Indicates} value.
.Delta.a ^* = (maximum value of the ^{a *} value _20, ^{a *} value _45, ^{a *} value _75, ^{a *} value ₁₁₀₎ - ^{(a *} value _20, ^{a *} value _45, ^{a *} value _75, ^{a *} value ₁₁₀ Minimum value)
Δb ^* = (b ^* value ₂₀ , b ^* value ₄₅ , b ^* value ₇₅ , b ^* value ₁₁₀ maximum value) − (b ^* value ₂₀ , b ^* value ₄₅ , b ^* value ₇₅ , b ^* value ₁₁₀ Minimum value)) The dry color according to claim 1,
A dry color, wherein the black pigment comprises carbon black. The dry color according to claim 1 or 2,
The dry color whose average primary particle diameter of the said black pigment is 5 nm-1 micrometer. The dry color according to claim 2,
The dry color whose specific surface area of the said carbon black is 10-400 m < ² > / g. The dry color according to any one of claims 2 to 4,
A dry color in which the black pigment consists of carbon black only. The dry color according to any one of claims 1 to 5,
A dry color containing a pigment other than the black pigment. The dry color according to any one of claims 1 to 6,
The dispersant is at least one selected from the group consisting of calcium stearate, zinc stearate, magnesium stearate, lithium stearate, stearic acid amide, ethylene bisamide, fatty acid amide, ester wax, polyethylene wax, and silane coupling agent. Including dry color. The dry color according to claim 7,
The dry color in which the dispersant includes any one of calcium stearate, zinc stearate, magnesium stearate, and lithium stearate. The dry collar according to any one of claims 6 to 8,
The other pigment includes one or more selected from phthalocyanine pigments, azo pigments, polycyclic pigments, ultramarine blue, cobalt, petiole, titanium oxide, nickel titanium yellow, and chrome titanium yellow. Color.   The resin molding material containing the dry color as described in any one of Claims 1 thru | or 9, and resin for dilution.   The molded object containing the resin molding material of Claim 10.   The manufacturing method of the resin molding material including the process of mixing the dry color as described in any one of Claims 1 thru | or 9, and resin for dilution.     The manufacturing method of a molded object including the process of injection-molding the resin molding material of Claim 10. A dry color evaluation method comprising a black pigment and a dispersant, wherein the dry color evaluation method evaluates whether or not the following conditions are satisfied.
(conditions)
100 parts by weight of polypropylene having a melt flow rate of 30 g / 10 min (JIS K7210: 1999) and a density of 0.9 g / cm ³ (JIS K7112: 1999) is mixed with 1 part by weight of the dry color to obtain a particle size of # 800 (JIS). R 6001: 1998) When using a mold polished with abrasive cloth, a resin plate was prepared by injection molding.
The a ^* value and b ^* value in the L ^* a ^* b ^* color system on the surface of the resin plate satisfy the following expressions (1) to (4).
D = [(a ^* value ₂₀₋ a ^* value ₄₅ ) ² + (b ^* value ₂₀₋ b ^* value ₄₅ ) ² ] ^1/2 + [(a ^* value ₄₅ −a ^* value ₇₅ ) ² + (b ^* The value ₄₅ -b ^* value ₇₅₎ ^{2] 1/2} + ^{[(a *} value ₇₅ -a ^* value ₁₁₀₎ ² + ^{(b *} value ₇₅ -b ^* value ₁₁₀₎ ^{2] 1/2} (1)
D <4.3 (2)
Δa ^* <2.5 (3)
Δb ^* <3.6 (4)
(In the formula, a ^* value ₂₀ , a ^* value ₄₅ , a ^* value ₇₅ , a ^* value ₁₁₀ , b ^* value ₂₀ , b ^* value ₄₅ , b ^* value ₇₅ , and b ^* value ₁₁₀ are equal to each other in multi-directional illumination. Using a directional light-receiving multi-angle colorimeter, each a ^* value when the perpendicular is 45 °, the light receiving part is 90 °, and the light source is 20 °, 45 °, 75 °, and 110 °, b ^{* Indicates} value.
.Delta.a ^* = (maximum value of the ^{a *} value _20, ^{a *} value _45, ^{a *} value _75, ^{a *} value ₁₁₀₎ - ^{(a *} value _20, ^{a *} value _45, ^{a *} value _75, ^{a *} value ₁₁₀ Minimum value)
Δb ^* = (b ^* value ₂₀ , b ^* value ₄₅ , b ^* value ₇₅ , b ^* value ₁₁₀ maximum value) − (b ^* value ₂₀ , b ^* value ₄₅ , b ^* value ₇₅ , b ^* value ₁₁₀ Minimum value))

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