JP2000143996A - Resin composition for coloring, its molded article and production of the article - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a resin composition having excellent smoothness and hiding property, etc., giving a molded article having improved state by improving the high-speed high-temperature processability and having high content of metal oxide by compounding a thermoplastic resin with a metal oxide having specified specific surface area and pore radius. SOLUTION: The objective composition contains (A) a metal oxide at least having a specific surface area of 1-50 m2/g and a pore radius of 50-150 Å and (B) a thermoplastic resin. The component A is preferably titanium dioxide, ultramarine blue, yellow iron oxide, etc., from the viewpoints of color, weather resistance, etc. The component A is preferably surface-treated with a silicone oil or a silane coupling agent. The addition amount of the surface-treating agent is 0.01-10 pts.wt. based on 100 pts.wt. of the component A. The component B is preferably a polyolefin. The objective composition wherein the component A is titanium dioxide and the component B is a polyolefin is preferably formed by melting and kneading both components at 180 deg.C and pelletizing the mixture.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a coloring resin composition containing a metal oxide, a molded article thereof, and a method for producing the molded article. More specifically, the present invention relates to a film having excellent concealing properties, smoothness, light discoloration resistance, and weather discoloration resistance, and particularly to a resin coating paper for photography formed by melt extrusion lamination and a method for producing the same.

[0002]

2. Description of the Related Art Conventionally, pigments using metal oxides include ultramarine blue, yellow iron oxide, titanium yellow, cobalt blue,
Titanium dioxide (hereinafter sometimes referred to as titanium oxide)
These are used in the field of plastic films, that is, packaging applications, building materials applications such as decorative boards, agricultural applications, and laminating applications applied to synthetic paper or release materials. In addition to having water of crystallization, the metal oxide adsorbs a large amount of water due to its hydrophilicity. Therefore, the metal oxide is easily aggregated and the dispersion is insufficient, so that a sufficient hiding property cannot be obtained. Therefore, in order to prevent aggregation of the metal oxide pigment particles and improve dispersibility, various surface treatments with inorganic or organic substances have been performed.

However, even with such a treatment, it is difficult to control the wetting and dispersion of the metal oxide in the thermoplastic resin, so that voids such as air bubbles are formed in the obtained molded product, and high-temperature high-speed processing is particularly difficult. Foaming and agglomeration of the film occurred in the resulting film.

A photographic resin-coated paper in which a paper base mainly composed of natural pulp is coated with a thermoplastic resin layer is disclosed, for example, in Japanese Patent Publication No. 55-12584, in which the base paper is a thermoplastic resin, preferably Techniques for photographic resin-coated paper coated with a polyolefin resin are disclosed. Also, in U.S. Pat. No. 3,501,298, sharpness is defined in the resin layer on the side on which the photographic image forming layer of the photographic resin coating paper on which both sides of the base paper are coated with a polyolefin resin is provided. It is disclosed that titanium dioxide is contained for providing.

As the titanium dioxide contained in the resin layer on the side of the photographic resin-coated paper on which the photographic image forming layer is provided, for example, JP-A-52-35625 and JP-A-5-35625
No. 7,108,849, wherein the surface of titanium dioxide is coated with a hydrous metal oxide such as hydrous aluminum hydroxide and hydrous silicon oxide,
JP-A-52-35625, JP-B-58-4373.
Japanese Patent Application Laid-Open No. 4 (1999) -26, Japanese Patent Publication No. 26655/1986, and the like, those coated or coated with organic substances such as polyhydric alcohols and derivatives thereof, and polyorganosiloxanes and derivatives thereof are known.

[0006] In recent years, in the field of photographic supports, there has been a strong demand for improved productivity, that is, high-speed processability of melt extrusion laminates, for cost reduction. When the polyolefin-based resin composition is melt-extruded and laminated at a high speed, the thickness of the film becomes thin, and a problem arises that a desired hiding property cannot be obtained with the conventional titanium oxide content. In order to solve such a problem, a method of ensuring a desired concealing property by containing a large amount of titanium oxide in the polyolefin-based resin composition has been tried, but various problems have occurred.

That is, even if the above-mentioned various coated titanium dioxides are used, if a thermoplastic resin composition containing a high concentration of titanium dioxide is to be produced, a slit die (T die: At present, agglomeration of titanium dioxide, gas foaming, and the like occur in the molten film cast from the film forming device, and a good film cannot be obtained.

In particular, in the field of melt extruded laminates such as photographic resin-coated paper, the temperature is from 250 to 350.degree.
Although processing at such a high temperature is required, the melt viscosity of the thermoplastic resin under such a high temperature is remarkably reduced, and not only the workability is lowered but also the film state is not smooth and cannot be put to practical use. There was a problem that.

[0009]

DISCLOSURE OF THE INVENTION The present invention solves the above-mentioned problems, and provides a metal oxide which is excellent in smoothness and concealability, and can improve the state of a molded article by improving high-speed high-temperature workability. It is an object of the present invention to provide a coloring resin composition having a high content of, a molded article thereof, and a method for producing the molded article.

[0010]

That is, the first invention is characterized by containing at least a metal oxide having a specific surface area of 1 to 50 m ² / g and a pore radius of 50 to 150 ° and a thermoplastic resin. It is a coloring resin composition.

[0011] The second invention is characterized in that the metal oxide is at least one metal oxide selected from the group consisting of titanium dioxide, ultramarine blue, yellow iron oxide, red iron oxide, titanium yellow, and cobalt blue. The coloring resin composition according to the first invention.

A third aspect of the present invention is a surface-treated metal oxide (a) obtained by treating 100 parts by weight of a metal oxide with 0.01 to 10 parts by weight of a surface treating agent. A coloring resin composition according to the second aspect of the invention.

A fourth invention is directed to a surface-treated metal oxide (a)
The coloring resin composition according to any one of the first to third inventions, comprising 1 to 65% by weight of

According to a fifth aspect of the present invention, there is provided a surface-treated metal oxide (a).
The coloring resin composition according to any one of the first to third inventions, comprising 20 to 85% by weight of

A sixth invention is a molded article using the coloring resin composition according to any one of the first to fifth inventions.

A seventh aspect of the present invention is a method for producing a molded article, comprising molding the coloring resin composition according to any one of the first to fifth aspects at 180 to 350 ° C.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.

The specific surface area of the metal oxide used in the present invention is 1 to 50 m ² / g, more preferably 3 to 45 m ² / g.
² / g. If it is less than 1 m ² / g, the molded article becomes brittle due to poor dispersion, and if it exceeds 50 m ² / g, thermal coagulation occurs, and the molded article is undesirably increased.

The metal oxide used in the present invention has a pore radius of 50 to 150 °, more preferably 60 to 140 °.
Å. If it is less than 50 °, the molded article becomes brittle due to poor dispersion of the metal oxide, and if it exceeds 150 °, irregularities in the molded article increase, which is not preferable.

The specific surface area and the pore radius of the metal oxide were measured using a gas adsorption method pore distribution meter, Micromeritex AS.
Using AP2000 (manufactured by Shimadzu Corporation), 1 g of a sample was weighed in a dedicated cell, dried under reduced pressure at 100 ° C. for 12 hours, and then measured using nitrogen gas.

The metal oxides of the present invention include single metal oxides such as red iron oxide, titanium dioxide, yellow iron oxide and black iron oxide, and complex oxides ultramarine, cobalt blue and titanium yellow. However, when at least one metal oxide selected from the group consisting of titanium dioxide, ultramarine blue, yellow iron oxide, red iron oxide, titanium yellow, and cobalt blue is used as a coloring pigment for plastic film use, color, weather resistance, and concealment are obtained. Excellent in terms of properties and the like.

Ultramarine, which is a composite oxide of the present invention, is a blue pigment containing silicon dioxide, alumina, sodium oxide, and bound sulfur as main components and containing sodium sulfate, ferric oxide, free sulfur and the like as impurities. As titanium yellow, TiO ₂ —BaO—NiO system, TiO ₂ —Sb ₂
O ₃ -NiO-based, such as _{TiO 2 -Sb 2 O 3 -Cr 2} O 3 system is exemplified, and as cobalt blue, CoO
—Al ₂ O ₃ and CoO—Al ₂ O ₃ —Cr ₂ O ₃ .

The iron oxide of the present invention, which is a single metal oxide, contains zinc, magnesium,
Include those containing aluminum or the like, also, the yellow iron oxide, and the like iron oxyhydroxide represented by FeOOH or _{Fe 2 O 3 · H 2 O} .

The titanium dioxide used in the present invention may be either anatase type or rutile type. Also, chlorine method,
It may be manufactured by any method such as a sulfuric acid method.

In order to improve the light stability or dispersibility of the titanium dioxide, its surface is previously coated with an inorganic substance such as aluminum oxide, silicon oxide, calcium oxide, zirconium oxide or a hydrate thereof. Is preferred. With respect to 100% by weight of titanium dioxide, 0.1% of these may be used alone or in combination of two or more.
It is desirable to add 1 to 0.8% by weight (in terms of inorganic oxide).

The titanium dioxide used in the present invention may contain aluminum in order to prevent discoloration to bluish black during high-temperature processing, and 0.02 to 1.0% by weight based on 100% by weight of titanium dioxide. Preferably.

The metal oxide used in the present invention can be used without being subjected to a surface treatment, but a surface-treated product is more preferable. Examples of the surface treatment agent used in the present invention include polyhydric alcohol, alkyldisilazane, alkanolamine, silicone oil, modified silicone, titanium coupling agent, and silane coupling agent. Particularly effective are silicone oils or silane coupling agents. As silicone oil,
Examples thereof include polydimethylsiloxane.

As a silane coupling agent, an alkylsilane coupling agent such as dimethyldimethoxysilane and hexyltrimethoxysilane, N-β (aminoethyl) γ
-Aminopropylmethyldimethoxysilane, N-β (aminoethyl) γ-aminopropylmethyltrimethoxysilane, N-β (aminoethyl) γ-aminopropylmethyltriethoxysilane, γ-aminopropyltriethoxysilane, γ-amino Propyltrimethoxysilane, N
Aminosilane coupling agents such as -phenyl-γ-aminopropyltrimethoxysilane, methacryloxysilane coupling agents such as γ-methacryloxypropyltrimethoxysilane and γ-methacryloxypropylmethyldimethoxysilane, vinyltrimethoxysilane, vinyltris ( vinylsilane coupling agents such as β-methoxyethoxy) silane, γ-glycidoxypropyltrimethoxysilane, β- (3,4-epoxycyclohexyl)
Epoxysilane coupling agents such as ethyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, mercaptosilane coupling agents such as β-mercaptoethyltriethoxysilane, other alkenyl groups,
Or an alkoxysilane having an isocyanate group or the like,
Chlorosilanes, polyalkoxyalkylsiloxanes and the like can be mentioned, and they can be used alone or in combination of two or more.

The surface treating agent used in the present invention is preferably added in an amount of 0.01 to 10 parts by weight based on 100 parts by weight of the metal oxide. If the amount is more than 10 parts by weight, foaming or blemishes are produced in the manufactured molded product due to decomposition of the surface treating agent itself, which is not preferable. If the amount is less than 0.01 part by weight, the amount of the surface treating agent on the surface of the metal oxide is not sufficient, and it is not preferable because a molded article is cracked. Further, when the metal oxide is titanium dioxide, it is more preferable to add 0.1 to 5 parts by weight to 100 parts by weight of titanium dioxide because the state of the molded article becomes extremely good.

As the thermoplastic resin used in the present invention, polyethylene, polypropylene, ethylene-propylene copolymer (including random or block copolymer)
Such as polyolefin, polystyrene, ABS resin, AS
Resins, polyvinyl chloride, polyester, polyacetal, polycarbonate, polyaromatic ethers, polyaromatic esters, polysulfones and the like may be used in combination if necessary. Among these, a molded article having good properties is obtained particularly in polyolefin.

In the coloring resin composition of the present invention, when the metal oxide is titanium dioxide and the thermoplastic resin is polyethylene, the titanium dioxide and the polyethylene are melt-kneaded at 200 ° C. or less, particularly preferably at 180 ° C. or less, It is preferably formed into a pellet. If the kneading is performed at a temperature higher than 200 ° C., a crosslinking reaction, thermal deterioration of the resin, and the like occur, and the formed molded product tends to have many defects.

As the kneader, a batch kneader such as a Banbury mixer, a twin-screw kneader, a single-screw extruder having a kneading function, a rotor-type twin-screw kneader, or the like can be used, but is not particularly limited. .

The coloring resin composition of the present invention contains a pigment at a high concentration, and is diluted with a resin to be colored (thermoplastic resin) at the time of molding, and is provided in the form of a pellet-shaped coloring resin composition (hereinafter, referred to as a thermoplastic resin). A masterbatch), or a resin composition for coloring in the form of pellets (hereinafter referred to as colored pellets) which has a relatively low pigment concentration and is directly used for molding without being diluted with the resin to be colored. There may be. Comparing the masterbatch and the colored pellets, there is no significant difference in the processing steps for obtaining them. However, the cost of the masterbatch is slightly higher than that of the colored pellets due to the high concentration of the pigment. However, in the case of a masterbatch,
Since a molded article can be obtained by diluting the master batch with an inexpensive resin to be colored, a molded article manufactured from the master batch is more inexpensive and preferable than a molded article manufactured from colored pellets.

The colored pellets of the present invention are made of metal oxide 10
It is desirable that the metal oxide (a) treated with 0.01 to 10 parts by weight of the surface treatment agent is contained in 1 to 65% by weight with respect to 0 parts by weight. When the metal oxide concentration is less than 1% by weight, concealing properties
If the physical properties such as color cannot be obtained, and if the content exceeds 65% by weight, defects such as bumps due to aggregation of metal oxides are apt to occur during molding of the molded product, which is not preferable.

When the metal oxide is titanium dioxide in the colored pellets or molded articles of the present invention, the colored pellets or molded articles are treated with 0.1 to 5 parts by weight of a surface treating agent per 100 parts by weight of titanium dioxide. Titanium 10
Preferably, it is contained in an amount of up to 60% by weight. If the concentration of titanium dioxide is less than 10% by weight, sufficient optical characteristics such as hiding properties and whiteness are difficult to obtain, which is not preferable. If the content is more than 60% by weight, defects such as bumps due to agglomeration of titanium easily occur during the production of a molded product, which is not preferable.

The masterbatch of the present invention may contain 20 to 85% by weight of the metal oxide (a) treated with 0.01 to 10 parts by weight of the surface treating agent based on 100 parts by weight of the metal oxide. desirable. If the metal oxide concentration is less than 20% by weight, it is difficult to obtain a sufficient color when diluted, which is not preferable. If it exceeds 85% by weight, it is difficult to uniformly disperse the metal oxide in the production process of the molded article, which is not preferable.

When the metal oxide is titanium dioxide in the masterbatch of the present invention, the masterbatch contains 30 to 80 parts by weight of titanium dioxide treated with 0.1 to 5 parts by weight of a surface treating agent per 100 parts by weight of titanium dioxide. %. If the concentration of titanium dioxide is less than 30% by weight, it is difficult to obtain sufficient optical properties when diluted, which is not preferable. If it exceeds 80% by weight, it is difficult to uniformly disperse titanium dioxide in the production process of the molded product, which is not preferable.

The colored pellets and the masterbatch of the present invention may contain, in addition to the components described above, an effect that does not impair the effect.
Known additives such as other optional pigments, antioxidants, dispersants, and ultraviolet absorbers can be added as necessary. Examples of the antioxidant include a phenolic antioxidant and a phosphorus antioxidant. Further, as a dispersant, a metal soap, that is, a metal salt of a higher fatty acid can be used, and calcium stearate, magnesium stearate, barium stearate, zinc stearate, aluminum stearate, calcium laurate, zinc laurate,
And magnesium laurate. The addition amount of the metal soap is preferably 1 to 8 parts by weight based on 100 parts by weight of the metal oxide.

The molded article of the present invention is produced by molding colored pellets as they are, or by diluting a masterbatch with a resin to be colored (uncolored resin containing no pigment) and molding and producing. As the resin used for the masterbatch, a resin having good compatibility with the resin to be colored is preferably used, and the same resin as the resin to be colored is more preferable.

The coloring resin composition of the present invention can be used to produce films, photographic resin-coated paper, and other plastic molded products.

In the method for producing a molded article of the present invention, when colored pellets are used as the resin composition for coloring, the colored pellets are melted, and are melted at 180 to 350 ° C., preferably at 21 ° C.
It is preferable to mold at 0 to 340 ° C. by injection molding, extrusion molding, blow molding and the like. Within this temperature range, a molded product having excellent workability can be obtained.

Further, in the method for producing a molded article of the present invention,
When a molded article is a film and a colored pellet in which the metal oxide is titanium dioxide is used, the colored pellet is melted and then melt-extruded from a slit die to form a film, which is produced by a type of extrusion T-die method. . The melt extrusion temperature at that time is 250-350 ° C., preferably 270-350 ° C.
340 ° C. Within this temperature range, a good film having a high white thin film can be obtained.

In the method for producing a molded article of the present invention, when a masterbatch is used as the resin composition for coloring, the masterbatch and the resin to be colored (thermoplastic resin for dilution) are melt-kneaded and then mixed at 180 to 350 ° C. , Preferably 210 to
Molding at 340 ° C. by injection molding, extrusion molding, blow molding or the like is preferred. Within this temperature range, a molded product having excellent workability can be obtained. As the thermoplastic resin for dilution, it is preferable to use a thermoplastic resin having good compatibility with that used for preparing the master batch, and more preferably the same resin.

Further, in the method for producing a molded article of the present invention,
When the molded product is a film and a masterbatch in which the metal oxide is titanium dioxide is used, the masterbatch and the resin to be colored (thermoplastic resin for dilution) are melt-kneaded,
It is manufactured by the T-die method. The melt extrusion temperature at that time is 250 to 350 ° C, preferably 270 to 340 ° C. Within this temperature range, a good film having a high white thin film can be obtained.

The thickness of the film formed using the coloring resin composition of the present invention is 5 to 200 μm, preferably 5 to 200 μm.
50 μm, more preferably 5 to 30 μm is desirable.

In the method for producing a molded article of the present invention, when the molded article is photographic resin-coated paper, it is desirable to produce it as follows. That is, colored pellets may be used in the same manner as in the film production described above, or a master batch may be used. These are melted in the same manner as in the production of a film, and the melt is extruded from a slit die onto a paper substrate to form a film, and the paper substrate is coated (this method is also called a melt extrusion lamination method). Suitable temperatures for melt extrusion are the same as for the film production described above. The thickness of the film formed on the paper substrate is desirably 5 to 200 μm, preferably 5 to 50 μm, and more preferably 5 to 30 μm.

[0047]

The present invention will be described in detail below with reference to Examples and Comparative Examples, but these are not intended to limit the present invention. (Example 1) 100 parts by weight of anatase type titanium dioxide was subjected to a surface treatment with 1 part by weight of dimethyldimethoxysilane to obtain a specific surface area of 6.3 m ² / g and a pore radius of 115.6 °.
Was obtained. 60 parts by weight of this surface-treated titanium dioxide is mixed with low-density polyethylene (specific gravity 0.9
23, melt flow rate (hereinafter referred to as MFR)
8 g / 10 min. ) 37.5 parts by weight and 2.5 parts by weight of zinc stearate were mixed, kneaded at 180 ° C using a twin-screw extruder having a kneading function, extruded and cooled, and then pelletized to obtain a master batch. Further, the obtained master batch and low density polyethylene (specific gravity 0.923, M
FR 7.8 g / 10 min. ) With a titanium dioxide concentration of 30
% By weight and using a T-die film molding machine (manufactured by Toyo Seiki) at a molding temperature of 320 ° C. and a rotation speed of 60 r.
The mixture was melt-extruded at pm to obtain a film-shaped molded product having a film thickness of 30 μm. Evaluation tests on the film strength and film state of the molded product were performed as shown below. Similarly, using a T-die film molding machine (manufactured by Toyo Seiki Co., Ltd.), a film-shaped molten mixture having a film thickness of 30 μm is melt-laminated on paper at a molding temperature of 340 ° C. and a rotation speed of 60 rpm. -Created paper. There were no defects such as pinholes on the coating surface (film surface) on the obtained photographic resin coating paper. A state evaluation test on the coating surface (film surface) was performed as shown below. Table 1 shows the results obtained above.

[Evaluation of Film Strength] Evaluation test by cross-section observation of film and film tensile test A: Film gap is extremely small, and film strength is sufficient. ：: The film gap is small, and the film strength is practically no problem. Δ: The film gap is slightly large, and the film strength is poor,
There is a workability problem. X: The film gap is large and the film is brittle.

[Evaluation of Film Condition and Evaluation of Photo-Resin Coating Paper Condition] Visual evaluation test A for film cracks, blemishes and the presence / absence of smoothness. A: Very good. B: No problem in practical use. C: There is a problem in any of film cracking, bumps and smoothness. D: Bad.

Example 2 A film-shaped molded product was obtained in the same manner as in Example 1 except that a surface-treated titanium dioxide having a specific surface area of 8.4 m ² / g and a pore radius of 90.9 ° was used. The same evaluation test as in Example 1 was performed on the molded product. Further, a photographic resin-coated paper was prepared in the same manner as in Example 1 and evaluated in the same manner. Table 1 shows the results obtained above.

Example 3 A film-shaped molded product was obtained in the same manner as in Example 1 except that a surface-treated titanium dioxide having a specific surface area of 7.6 m ² / g and a pore radius of 129.5 ° was used. The same evaluation test as in Example 1 was performed on the molded product. Further, a photographic resin-coated paper was prepared in the same manner as in Example 1 and evaluated in the same manner. Table 1 shows the obtained results.
Shown in

(Comparative Example 1) A masterbatch and a film-like molded product were produced in the same manner as in Example 1 except that a surface-treated titanium dioxide having a specific surface area of 0.4 m ² / g and a pore radius of 160.9 ° was used. And the same molded article was subjected to the same evaluation test as in Example 1. Also, a photographic resin-coated paper was prepared in the same manner as in Example 1 and evaluated in the same manner. Table 1 shows the obtained results.

(Comparative Example 2) Specific surface area 160.5 m ² / g
A masterbatch and a film-like molded product were obtained in the same manner as in Example 1 except that a surface-treated amorphous titanium dioxide having a pore radius of 40.7 ° was used, and the same evaluation as in Example 1 was performed on the molded product. The test was performed. Also, a photographic resin-coated paper was prepared in the same manner as in Example 1 and evaluated in the same manner. Table 1 shows the obtained results.

(Example 4) Rutile type titanium dioxide 100
1 part by weight of polydimethylsiloxane was subjected to a surface treatment with respect to the parts by weight, and the specific surface area was 6.4 m ² / g, and the pore radius was 115 °.
Was obtained. 50 parts by weight of this surface-treated titanium dioxide is mixed with 50 parts by weight of polyethylene terephthalate (softening temperature: 225 ° C., Tg: 77 ° C.), kneaded and extruded at 260 ° C. using a twin-screw extruder having a kneading function, cooled, and then pelletized. Master batch was obtained. Furthermore,
The masterbatch and the polyethylene terephthalate were blended so that the titanium dioxide concentration became 10% by weight.
Using a die film molding machine (manufactured by Toyo Seiki Co., Ltd.), melt extrusion was performed at a molding temperature of 270 ° C. and a rotation speed of 60 rpm, and the film thickness was 30 μm.
m in the form of a film. An evaluation test was performed on the film strength and film state of the molded product. Table 1 shows the results. In addition, even if this film is biaxially stretched (stretching ratio is 2 times), there is no problem due to a film crack or breakage,
It was confirmed that the strength was sufficient.

Comparative Example 3 A masterbatch and a film-like molded product were obtained in the same manner as in Example 4 except that a surface-treated rutile type titanium dioxide having a specific surface area of 0.4 m ² / g and a pore radius of 155 ° was used. The same evaluation test as in Example 4 was performed on the composition. Table 1 shows the results. The film of the composition had many cohesion spots, and was at a practically problematic level.

(Example 5) Titanium yellow (specific gravity 4.4)
-4.7) 2 parts by weight of dimethyldimethoxysilane was subjected to a surface treatment with respect to 100 parts by weight to obtain a surface-treated titanium yellow having a specific surface area of 5 m ² / g and a pore radius of 130 °. 60 parts by weight of this surface-treated titanium yellow is mixed with high-density polyethylene (specific gravity 0.965, MFR 13.0 g / 10 mi)
n. ) 37.5 parts by weight and 2.5 parts by weight of low molecular weight polyethylene wax, kneaded at 200 ° C using a twin screw extruder having a kneading function, extruded and cooled, and then pelletized to obtain a master batch. . Further, the master batch and high-density polyethylene (specific gravity 0.965, MFR1
3.0 g / 10 min. ) Having a titanium yellow concentration of 20
% By weight and using a T-die film molding machine (manufactured by Toyo Seiki) at a molding temperature of 300 ° C. and a rotation speed of 60 r.
The mixture was melt-extruded at pm to obtain a film-shaped molded product having a film thickness of 60 μm. Foaming and the like were not observed in the film of the molded product, which was favorable. An evaluation test was performed on the film strength and film state of the molded product. Table 1 shows the results.

Example 6 Example 5 was repeated except that titanium yellow (specific surface area: 3 m ² / g, pore radius: 120 °) treated similarly to titanium yellow was used in place of titanium yellow of Example 5. Similarly, a master batch and a film-like molded product were obtained. The composition was in a very good condition with few bumps. The same evaluation test as in Example 5 was performed on the molded product. Table 1 shows the results.

Comparative Example 4 A masterbatch and a film-like molded product were obtained in the same manner as in Example 5 except that a surface-treated titanium yellow having a specific surface area of 0.1 m ² / g and a pore radius of 188 ° was used. The molded article has many bumps on the surface,
This was a practically problematic level. The molded article was subjected to an evaluation test in the same manner as in Example 5. Table 1 shows the results.

[0059]

[Table 1]

[0060]

According to the present invention, a plastic molded article having excellent strength and the like can be obtained even if the content of metal oxide is increased.
In particular, it has become possible to provide films, high-temperature melt-laminated films, and especially excellent resin coating paper for photography.

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Masayasu Kawamura 2-3-13 Kyobashi, Chuo-ku, Tokyo Toyo Ink Manufacturing Co., Ltd. F-term (reference) 4J002 BB031 BB121 BB151 BC031 BC061 BD041 BN151 BP021 CB001 CF031 CG001 CH071 CN031 DE096 DE116 DE126 DE136 DE146 DJ006 DK006 FB086 FB096 FB106 FB116 FB126 FB136 FB146 FB156 FB166 FD096

Claims (7)

[Claims] (1) at least a specific surface area of 1 to 50 m ² /
g, a coloring resin composition comprising a metal oxide having a pore radius of 50 to 150 ° and a thermoplastic resin. 2. The metal oxide according to claim 1, wherein the metal oxide is at least one metal oxide selected from the group consisting of titanium dioxide, ultramarine blue, yellow iron oxide, red iron oxide, titanium yellow, and cobalt blue. Coloring resin composition. 3. The coloring according to claim 1, wherein the metal oxide is a surface-treated metal oxide (a) obtained by treating 0.01 to 10 parts by weight of a surface treating agent to 100 parts by weight of a metal oxide. Resin composition. 4. The coloring resin composition according to claim 1, comprising 1 to 65% by weight of the surface-treated metal oxide (a). 5. The surface-treated metal oxide (a) is added in an amount of 20 to 85.
The coloring resin composition according to any one of claims 1 to 3, wherein the coloring resin composition is contained by weight. 6. A molded article using the coloring resin composition according to any one of claims 1 to 5. 7. A method for producing a molded article, comprising molding the coloring resin composition according to claim 1 at 180 to 350 ° C.