JP2021147557A - Resin composition for molding coloring, molding, and masterbatch - Google Patents

Abstract

To provide a resin composition for molding coloring, a masterbatch, and a molding, which can suppress a bronze phenomenon.SOLUTION: A resin composition for molding coloring contains a pearl pigment and a thermoplastic resin. When a particle diameter corresponding to a cumulative 50%-particle size in a volume-based cumulative fraction by a laser diffraction scattering method of the pearl pigment is represented by D50, and a particle diameter corresponding to a cumulative 75%-particle size is represented by D75, (a) D50 is 1.0 μm or more and 35 μm or less, and (b) (D75-D50)/D50 is 0.5 or less.SELECTED DRAWING: None

Description

The present invention relates to a resin composition for coloring a molded product, a molded product, and a masterbatch.

Conventionally, pearl pigments are known to exhibit metallic luster, and various resin molded products using pearl pigments have been developed. For example, Patent Document 1 discloses that a molded product made of a thermoplastic resin composition containing 0.5 to 50% by mass of a synthetic mica pearl pigment has a metallic luster.

On the other hand, in the resin molded body that has been three-dimensionally processed, the reflection of light changes depending on the difference in the angle observed by the user. Therefore, a phenomenon in which the color, impression, aesthetics, etc. felt by the user are different occurs, and as a result, the quality image on the appearance may be deteriorated and the sense of unity may be impaired. A bronze phenomenon similar to metallic luster is known as a cause of such a phenomenon.
There are various factors that cause the bronze phenomenon, and the details of the mechanism are not clear. As a result of seeing such things, it is presumed that the bronze phenomenon is observed.

Japanese Unexamined Patent Publication No. 2006-9035

Therefore, as a result of diligent studies to suppress the bronze phenomenon in the resin molded body, the present inventors have made a pearl pigment by blending a pearl pigment having a specific particle size distribution into the resin molded body, contrary to the prior art. We have obtained a new finding that the bronze phenomenon can be reduced while suppressing the metallic luster caused by the resin.

The present invention is a resin composition for coloring a molded product, which comprises a pearl pigment and a thermoplastic resin.
When the particle size corresponding to the cumulative 50% of the cumulative fraction of the pearl pigment by the laser diffraction / scattering method is D _50, and the particle size corresponding to the cumulative 75% is D ₇₅ .
(A) D ₅₀ is 1.0 μm or more and 35 μm or less, and (b) (D _75- D ₅₀ ) / D ₅₀ is 0.5 or less.
A resin composition for coloring a molded product is provided.

The present invention provides a molded product using the resin composition for coloring a molded product.

The present invention provides a master batch made of the above-mentioned resin composition for coloring a molded product.

According to the present invention, a resin composition for coloring a molded product, a master batch, and a molded product capable of suppressing the bronze phenomenon are provided.

Hereinafter, embodiments of the present invention will be described. In the present specification, the term "abbreviation" means to include a range in consideration of manufacturing tolerances, assembly variations, etc., unless otherwise specified explicitly. In the present specification, the notation "a to b" in the description of the numerical range means a or more and b or less unless otherwise specified. For example, "1 to 5% by mass" means "1% by mass or more and 5% by mass or less".

<Resin composition for coloring molded products>
In the present embodiment, the resin composition for coloring a molded product contains a pearl pigment and a thermoplastic resin, and the pearl pigment has a predetermined particle size distribution. The resin composition for coloring a molded product of the present embodiment is preferably used mainly for a molded product in which suppression of the bronze phenomenon is preferred. Hereinafter, each component will be described in detail.

[Pearl pigment]
In this embodiment, the pearl pigment is used to suppress the bronze phenomenon. A pearl pigment is a pigment that exhibits a pearly luster.
In the pearl pigment of the present embodiment, the particle size corresponding to the cumulative 50% in the volume-based cumulative fraction of the cumulative particle size distribution by the laser diffraction / scattering method is D _50, and the particle size corresponding to the cumulative 75% is D ₇₅ . When you do
(A) D ₅₀ is 1.0 μm or more and 35 μm or less, and (b) (D _75- D ₅₀ ) / D ₅₀ is 0.5 or less.

That is, while the condition (a) specifies the central particle size of the pearl pigment, the condition (b) suppresses the variation in the particle size and reduces the proportion of the pearl pigment on the larger particle size distribution. Moreover, the variation in particle size distribution is suppressed. It is presumed that this makes it possible to effectively suppress glare caused by the pearl pigment while reducing the bronze feeling by utilizing the luster (reflection and interference of light) of the pearl pigment.
Among them, there are various factors that cause the bronze phenomenon, and the details of the mechanism are not clear. However, in the present embodiment, bronze is suppressed by controlling the particle size and particle size distribution of the pearl pigment for the following reasons. It is presumed that can be suppressed. That is, the color that changes depending on the viewing angle that occurs in the color that is felt as bronze and the color change that is felt due to the difference in angle due to the pearl pigment (that is, the metallic luster due to the reflection and interference of light of the pearl pigment) match. It is presumed that the reflection of light is appropriately controlled in the entire molded body.

The lower limit of D ₅₀ is 1.0 μm or more, preferably 5.0 μm or more, and more preferably 9.0 μm or more from the viewpoint of obtaining the bronze suppressing effect of the pearl pigment. On the other hand, _{the upper limit of D 50} is 35 μm or less, preferably 30 μm or less, and more preferably 25 μm or less from the viewpoint of suppressing the occurrence of metallic luster and glare caused by the pearl pigment.
Further, (D _75- D ₅₀ ) / D ₅₀ is 0.5 or less from the viewpoint of effectively suppressing glare caused by the pearl pigment by suppressing the variation in the particle size distribution on the side where the particle size is large. , 0.4 or less, more preferably 0.3 or less.

Examples of the pearl pigment include those in which the surface of the base material is coated with a metal oxide, scaly foil pieces such as basic lead carbonate, lead hydrogen arsenate, and bismuth oxide, fish scale powder, shell pieces, and pearl pieces. .. Among them, those in which the surface of the base material is coated with a metal oxide are preferable from the viewpoint that the hue and pearly feeling exhibited by the pearl pigment can be adjusted and the bronze phenomenon is stably suppressed.
Examples of the metal oxide include titanium oxide and iron oxide. The metal oxide may be one layer or two or more layers, and for example, an iron oxide layer may be laminated on a titanium oxide layer. It is preferable that the base material is coated with the titanium oxide layer from the viewpoint of effectively suppressing the bronze phenomenon. The coating is not limited to the case where the whole is continuous, and may have an uncovered region in a part thereof.
Further, by adjusting the thickness of the metal oxide layer, it becomes easy to control the hue and pearl color of the pearl pigment. The thickness of the metal oxide layer is appropriately adjusted according to the intended use and purpose, and examples thereof include 40 to 160 nm.
Examples of the above-mentioned base material include one or more selected from muscovite, biotite, phlogopite, mica such as synthetic phlogopite, mica, glass, alumina, and silica. The shape of the base material may be flaky from the viewpoint of exhibiting the luster peculiar to the pearl pigment.

The aspect ratio of the pearl pigment is not particularly limited, but may be, for example, 5 to 100 or 10 to 80.

The content of the pearl pigment is preferably 0.001% by mass or more, more preferably 0.002% by mass or more, and further preferably 0.003% by mass or more with respect to the molded product. As a result, the bronze phenomenon can be effectively suppressed while maintaining the suppression of glare caused by the pearl pigment.
On the other hand, the content of the pearl pigment is preferably 10% by mass or less, more preferably 5% by mass or less, further preferably 1% by mass or less, still more preferably 0.4% by mass or less, based on the molded product. As a result, it is possible to reduce glare caused by pearls while suppressing the bronze phenomenon.
That is, the bronze phenomenon can be effectively suppressed by controlling the mass of the pearl pigment with respect to the total mass of the molded product obtained by using the resin composition for coloring the molded product of the present embodiment.

The resin composition for coloring the molded product of the present embodiment may further contain a pigment other than the pearl pigment described later. In this case, the total content of the pigment is preferably 0.01% by mass or more, more preferably 0.02% by mass or more, still more preferably 0.03% by mass or more, based on the molded product. On the other hand, the total content of the pigment is preferably 10% by mass or less, more preferably 5% by mass or less, further preferably 3% by mass or less, still more preferably 1% by mass or less, based on the molded product.

[Thermoplastic resin]
The thermoplastic resin is not particularly limited as long as it is a resin used in the resin composition for coloring a molded product, and a known resin can be used. Examples of the thermoplastic resin include polyolefin resin, polystyrene resin, acrylonitrile-butadiene-styrene (ABS) resin, polycarbonate resin, polyamide resin, polyester resin, polybutylene terephthalate resin, and polymethyl methacrylate resin (PMMA). One or more selected species may be mentioned. Among them, a polyolefin resin is preferable, and a polyethylene resin or a polypropylene resin is more preferable, from the viewpoint of effectively suppressing the bronze phenomenon.

[Use of resin composition for coloring molded article]
The resin composition for coloring a molded product of the present embodiment can be produced by a known method, and may be used, for example, as a masterbatch described later, or may be used in a compound together with various optional components.
The compound means the entire amount of the resin composition which is the raw material of the molded product. The compound may contain a powdery dry color as a coloring component. The dry color is a pigment wrapped in metal soap, hardened castor oil, polyethylene wax, or the like.

<Masterbatch>
The masterbatch of the present embodiment is made by using the above-mentioned resin composition for coloring a molded product, and is pelletized together with various additives added as needed. Since the masterbatch is concentrated, it is diluted with a diluting resin and used at the time of manufacturing the molded product.

The concentration of the pearl pigment contained in the masterbatch is set according to the finally obtained molded product, but may be set as follows, for example.
The concentration of the pearl pigment contained in the masterbatch is, for example, preferably 0.01 to 30% by mass, more preferably 0.05 to 20% by mass, and further preferably 0.5 to 15% by mass with respect to the entire masterbatch. preferable. By setting the concentration of the pearl pigment to the above lower limit value or more, the bronze phenomenon can be easily suppressed, and by setting the concentration to the above upper limit value or less, glare due to the pearl pigment can be stably suppressed.

The masterbatch includes pigments other than pearl pigments, ester-based waxes, metal soaps, polyethylene waxes, antioxidants, UV absorbers, antistatic agents, and other stabilizers, flame retardants, as long as the effects of the present invention are not impaired. Various additives such as a surfactant may be added.

The pigment other than the pearl pigment may be either an inorganic pigment or an organic pigment. For example, black inorganic pigments such as carbon black, black iron oxide (triiron tetraoxide), black titanium oxide, copper manganese black, copper chrome black, and cobalt black: cyanine black, and black organic pigments such as aniline black: phthalocyanine blue. Phthalocyanine pigments such as phthalocyanine green: azo yellow lake, azo lake red, mono azo yellow and other azo pigments: quinacridone pigments, perylene pigments, quinophthalone pigments, anthraquinone pigments and other polycyclic pigments: ultramarine, cobalt, petals, titanium oxide , Nickel titanium yellow, chromium titanium yellow and other inorganic pigments may be contained. As these pigments, one kind or two or more kinds can be used.
Among them, it is preferable to contain black pigment, phthalocyanine pigment, ultramarine blue, cobalt and the like from the viewpoint of effectively suppressing the bronze phenomenon due to the synergistic effect with the pearl pigment. Further, it is preferable to appropriately combine the hue of the light of the pearl pigment in the L ^* a ^* b ^* color coordinates and the hue of the main L ^* a ^* b ^{* color coordinates of the pigment other than the pearl pigment.}

The content of the entire pigment (total of pearl pigment and pigments other than pearl pigment) is preferably 1 part by mass or more and 2 parts by mass or more with respect to 100 parts by mass of the thermoplastic resin of the masterbatch. It is preferably 4 parts by mass or more, and more preferably 4 parts by mass or more. As a result, the molded product can be colored in a desired color while suppressing the bronze phenomenon.
On the other hand, the content of the entire pigment (total of pearl pigment and pigments other than pearl pigment) is preferably 50 parts by mass or less, preferably 20 parts by mass or less, with respect to 100 parts by mass of the thermoplastic resin of the masterbatch. Is more preferable. As a result, the pigment can be satisfactorily kneaded with the thermoplastic resin.

Ester waxes are used to facilitate uniform blending of pigments. The ester wax preferably has a softening temperature of about 100 ° C. or lower. For example, monotanic acid wax, hardened castor oil, etc., which are solid at room temperature, are preferable, and montanic acid and one or more aliphatic dihydric alcohols such as ethylene glycol, 1,4-butanediol, and 1,6-hexanediol are used. It is more preferable that it is an ester of. Examples of commercially available products include Hoechst's product "Hoechst Wax E" and BASF's product "E Wax BASF".

In addition, 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 polymers, and those obtained by thermally decomposing polyethylene. From the viewpoint of improving the dispersibility of pigments, ethylene is used at high temperature and high pressure. The one polymerized below is preferable. Further, the obtained polymer may be oxidized or acid-modified. Examples of commercially available products include "High Wax" manufactured by Mitsui Chemicals, Inc. and "AC" manufactured by Honeywell.

[Manufacturing method of masterbatch]
The masterbatch in this embodiment is manufactured as follows.
First, for example, a normal kneader such as a Bambari mixer, a kneader, or a twin-screw extruder is used to knead the pearl pigment, the thermoplastic resin, and other necessary additives, and the pearl pigment is kneaded into the thermoplastic resin. Next, a masterbatch is obtained by discharging a mixture of the pearl pigment and the thermoplastic resin from the die of the kneader.

[Resin for dilution]
The dilution resin is a main raw material used as a material for a molded product, which will be described later, and is a resin for diluting the above-mentioned masterbatch at the time of molding the molded product.
As the dilution resin, the same resin as the above-mentioned thermoplastic resin is used. For example, a polyolefin resin such as polyethylene and polypropylene, a styrene resin, an acrylonitrile-butadiene-styrene (ABS) resin, a polycarbonate resin, a polyamide resin, and a polyester resin. , And polymethyl methacrylate resin (PMMA) and the like. These may be used individually by 1 type, and may be used in mixture of 2 or more type. Of these, a polyolefin resin is preferable from the viewpoint of effectively suppressing the generation of bronze.
The dilution resin may be the same as or different from the thermoplastic resin contained in the masterbatch, but from the viewpoint of improving various properties of the molded product, the same type of thermoplastic resin may be used. Is preferable.

Further, in the present embodiment, the masterbatch is preferably diluted 5 to 100 times, more preferably 10 to 50 times, with a dilution resin.

<Molded body>
The molded product comprises the above-mentioned resin composition for coloring the molded product.
Further, as a method for producing the molded product, a known method can be used. For example, the resin composition for coloring a molded product is placed in a mold or a method of blow molding, extrusion molding, inflation molding, film molding with a T-die, or injection molding together with an additive as required, and press molding. There is a way to do it. In either method, the effect of suppressing the occurrence of the bronze phenomenon can be obtained.

The molded product of the present embodiment has the bronze phenomenon suppressed. It can be used in the fields of electronic / electrical / OA equipment, furniture, miscellaneous goods, automobile exterior / interior parts, etc., where appearance is emphasized and processed into various shapes.

Although the embodiments of the present invention have been described above, these are examples of the present invention, and various configurations other than the above can be adopted.

Next, the present invention will be described in detail by way of examples, but the content of the present invention is not limited to the examples.

<Examples and Comparative Examples>
(material)
The materials used in the examples and comparative examples are as follows.
[Thermoplastic resin]
-Polyethylene "Petrosen 353" Manufacturer: Tosoh Corporation [Pearl pigment]
・ "Iriodin (R) 221 Rutile Fine Blue" (Iriogin 221) Manufacturer: Merck Co., Ltd. ・ "Iriodin (R) 289 Rutile Fine Blue" (Iriogin 289) Manufacturer: Merck Co., Ltd. [Other pigments]
-Pigment (blue) "Ultramarine No. 8000" Manufacturer: Daiichi Kasei Kogyo Co., Ltd.-Pigment (blue) "Lionol Blue SL" Manufacturer: Toyo Color Co., Ltd.-Pigment (red) "Cinquasia Pink K4430FP" Manufacturer: BASF, pigment (black) "Carbon # 30B" Manufacturer: Mitsubishi Chemical Co., Ltd., pigment (black) "Carbon BP880" Manufacturer: Cabot

(Creating a masterbatch)
Using the above materials, the pearl pigment, other pigments, and the thermoplastic resin are biaxially arranged so as to have the composition shown in Table 1 (mass%, where "%" in the table indicates "mass%"). Using an extruder, kneading was performed at a molding temperature of 50 to 160 ° C. and an extruder rotation speed of 200 rpm, and the obtained kneaded product was discharged from a die to obtain a masterbatch.

(Creation of molded product)
A molding material was prepared by mixing 1 part by mass of each of the obtained master batches with a polyethylene resin (“Petrosen 353” manufactured by Tosoh Corporation) as a dilution resin so as to have the dilution concentration shown in Table 1. .. A molded product (resin plate: size 80 × 50 mm, thickness 2 mm) was prepared from the obtained molding material by an injection molding machine.

<Evaluation>
The following evaluations were made for each of the pearl pigment and the resin plate. The results are shown in Table 1.

(Diffraction of particle size of pearl pigment by laser diffraction scattering method)
Particle size diffraction was performed by a laser diffraction / scattering method (laser diffraction / scattering type particle size distribution measuring device, manufactured by HORIBA, "LA-960") to determine D ₅₀ (μm) and D ₇₅ (μm) of pearl pigments. ..

(Evaluation of bronze phenomenon)
Five experts visually observe the surface color of each prepared resin plate from various angles, observe the presence or absence of subtle hue changes (bronze phenomenon) that cannot be measured with a colorimeter, and use the following criteria. evaluated. The results are shown in Table 1.
⊚: Five experts judged that there was no change in hue.
〇: Three of the five experts judged that there was no change in hue, but two judged that there was a change in hue.
X: Five experts judged that there was a change in hue.

The bronze phenomenon was suppressed in all of Examples 1 to 5, whereas the bronze phenomenon was observed in Comparative Examples 1 to 4. Specifically, in Examples 1 to 4, the black tint did not change even when the angle was changed. In Example 5, although the bronze phenomenon was suppressed, there was an opinion that it may be felt that a bright material was blended. Comparative Examples 1, 2 and 4 were bronze in black and yellowish black depending on the angle. Comparative Example 3, the large D ₅₀ of the pearl pigments, for the color of the pearl color and other pigments are not tuned, bronze feeling was felt strongly.

Claims (8)

A resin composition for coloring a molded product containing a pearl pigment and a thermoplastic resin.
When the particle size corresponding to the cumulative 50% of the cumulative fraction of the pearl pigment by the laser diffraction / scattering method is D _50, and the particle size corresponding to the cumulative 75% is D ₇₅ .
(A) A resin composition for coloring a molded product, wherein _{D 50} is 1.0 μm or more and 35 μm or less, and (b) (D _75- D ₅₀ ) / D _{50 is 0.5 or less.} The resin composition for coloring a molded product according to claim 1, wherein the content of the pearl pigment is 0.001% by mass or more and 10% by mass or less with respect to the entire molded product. The resin composition for coloring a molded product according to claim 1 or 2, wherein the surface of the base material is coated with a metal oxide. The resin composition for coloring a molded product according to claim 3, wherein the base material is one or more selected from mica, mica, glass, alumina, and silica. The resin composition for coloring a molded product according to any one of claims 1 to 4, further comprising a pigment other than the pearl pigment. The thermoplastic resin is selected from polyolefin resin, polystyrene resin, acrylonitrile-butadiene-styrene (ABS) resin, polycarbonate resin, polyamide resin, polyester resin, polybutylene terephthalate resin, and polymethyl methacrylate resin (PMMA). The resin composition for coloring a molded body according to any one of claims 1 to 5, which comprises one kind or two or more kinds. A masterbatch using the resin composition for coloring a molded product according to any one of claims 1 to 6. A molded product using the resin composition for coloring a molded product according to any one of claims 1 to 6.