JP6175876B2 - Polyolefin resin composition and molded body - Google Patents

Description

  The present invention relates to a polyolefin resin composition having excellent pigment dispersibility and good molded product productivity, and a molded product obtained by molding this polyolefin resin composition.

  In recent years, polyolefin resins such as polyethylene, polypropylene, and polybutene are one of the general-purpose resins that are most widely used in the fields of automobiles, home appliances, and the like because they have excellent basic properties such as light weight and high rigidity. . In these applications, the polyolefin resin is usually used as a coloring material to which a pigment is added. When a pigment is added to the polyolefin resin, a dispersant is generally added to improve the dispersibility of the pigment.

  As such a dispersant, Patent Document 1 proposes a dispersant using an alkyl methacrylate polymer having an alkyl group having 2 or more carbon atoms. However, in the method proposed in Patent Document 1, although the undispersed material derived from the pigment is reduced, there is a problem that color unevenness occurs in a molded product obtained from this resin composition.

  In addition, as a dispersant for a pigment for a polyolefin resin, a fatty acid metal salt such as magnesium stearate, aluminum stearate or calcium stearate, or a polyolefin wax such as polyethylene wax or polypropylene wax is generally used. For example, Patent Document 2 proposes calcium stearate as a pigment dispersant.

International publication 2011/096596 pamphlet JP-A-8-81592

  However, although fatty acid metal salts such as calcium stearate improve the dispersibility of the pigment in the resin composition, there is an effect of lubricity, so that the ejection amount of the resin composition is reduced in extrusion molding and the like, It had the subject that productivity of a molded object fell.

  An object of the present invention is to provide a polyolefin resin composition having excellent dispersibility of pigments in a resin composition and good molded product productivity. Another object of the present invention is to provide a molded article obtained from a polyolefin resin composition and having an excellent molded appearance without color unevenness.

  The present invention is a polyolefin resin composition comprising a polyolefin resin (A), a pigment (B), a first dispersant (C) and a second dispersant (D), wherein the first dispersant (C) Is a fatty acid metal salt and / or a wax, and the second dispersant (D) contains an alkyl methacrylate polymer containing 50% by mass or more of an alkyl methacrylate (d1) unit having an alkyl group having 2 or more carbon atoms. It is a polyolefin resin composition.

  Moreover, this invention is a molded object obtained by shape | molding the said polyolefin resin composition.

  The polyolefin resin composition of the present invention is excellent in the dispersibility of the pigment in the resin composition, and the productivity of the molded article is good. Moreover, the molded object obtained from this polyolefin resin composition does not have a color nonuniformity, and is excellent in an external appearance.

  Hereinafter, the polyolefin resin composition and molded article of the present invention will be described. In the present specification, “(co) polymer” means “homopolymer” or “copolymer”. “(Meth) acrylate” means “acrylate” or “methacrylate”.

[Polyolefin resin (A)]
In the present invention, a known polyolefin resin can be used as the polyolefin resin (A), and examples thereof include the following. Polypropylene (PP), high density polyethylene (HDPE), low density polyethylene (LDPE), linear low density polyethylene (LLDPE), poly-1-butene, polyisobutylene, ethylene-propylene random copolymer or block copolymer Polymer, ethylene-propylene-1-butene random copolymer or block copolymer, ethylene-propylene-diene terpolymer, ethylene or copolymer of propylene and cyclopentadiene, ethylene or propylene and 50% by mass A random copolymer, block copolymer or graft polymer obtained from the following vinyl monomers (for example, vinyl acetate, methacrylic acid ester, acrylic acid ester, aromatic vinyl monomer, etc.). These polyolefin resin (A) may be used individually by 1 type, and may use 2 or more types together.

Among these, polypropylene, ethylene-propylene random copolymer or block copolymer, ethylene-propylene-1-butene random copolymer or block copolymer, ethylene-propylene-diene terpolymer, propylene And a copolymer of cyclopentadiene, a random copolymer obtained from propylene and 50% by mass or less of a vinyl monomer, a block copolymer or a graft polymer are preferred, and a random copolymer of polypropylene and ethylene-propylene More preferred are a polymer or block copolymer, a random copolymer of ethylene-propylene-1-butene, a block copolymer, or an ethylene-propylene-diene terpolymer.
It is excellent in the dispersibility of the 2nd dispersing agent (D) mentioned later that it is a (co) polymer of propylene.

[Pigment (B)]
In the present invention, the pigment (B) is not particularly limited as long as it is generally used as a pigment for polyolefin resins, and examples thereof include the following. Organic pigments such as azo, phthalocyanine, quinacridone, dioxazine, perylene, and isoindolinone; and inorganic pigments such as titanium oxide, petal, red lead, carbon black, iron black, ultramarine, and cobalt blue; Is mentioned. These organic pigments and inorganic pigments may be used alone or in combination of two or more.

  The content of the pigment (B) in the polyolefin resin composition of the present invention is preferably 0.01 to 5 parts by mass, and 0.05 to 2 parts by mass with respect to 100 parts by mass of the polyolefin resin (A). It is more preferable that When the content of the pigment (B) is 0.01 parts by mass or more, an excellent coloring effect can be obtained in the molded body. Further, when the content of the pigment (B) is 5 parts by mass or less, it is possible to suppress the appearance defect of the molded body derived from the undispersed pigment (B).

[First dispersant (C)]
In the present invention, as the first dispersant (C), at least one of known fatty acid metal salts and waxes known as pigment dispersants is used. Examples of the fatty acid metal salt include calcium stearate, magnesium stearate, aluminum stearate, zinc stearate and the like. Examples of the wax include natural waxes such as montan wax, paraffin wax, and carnauba wax; and synthetic waxes such as polyethylene wax, polypropylene wax, and montanic acid ester wax. These 1st dispersing agents (C) may be used individually by 1 type, and may use 2 or more types together.

  The content of the first dispersant (C) in the polyolefin resin composition of the present invention is preferably 0.01 to 5 parts by mass with respect to 100 parts by mass of the polyolefin resin (A). More preferably, it is ˜2 parts by mass. When the content of the first dispersant (C) is 0.01 parts by mass or more, the dispersibility of the pigment (B) in the polyolefin resin (A) is excellent. Further, when the content of the first dispersant (C) is 5 parts by mass or less, the slipperiness of the polyolefin resin composition can be suppressed, and the decrease in the discharge amount of the resin composition in extrusion molding can be suppressed. .

[Second Dispersant (D)]
In the present invention, the second dispersant (D) is an alkyl methacrylate polymer (hereinafter simply referred to as “alkyl methacrylate polymer” containing 50% by mass or more of an alkyl methacrylate (d1) unit having an alkyl group having 2 or more carbon atoms. In some cases). That is, the polymer is a (co) polymer having 50 to 100% by mass of an alkyl methacrylate (d1) unit having an alkyl group having 2 or more carbon atoms and 50 to 0% by mass of another monomer (d2) unit. is there.

  Examples of the alkyl methacrylate (d1) used as a raw material for the alkyl methacrylate (d1) unit having an alkyl group having 2 or more carbon atoms include the following. Ethyl methacrylate, n-propyl methacrylate, i-propyl methacrylate, n-butyl methacrylate, i-butyl methacrylate, sec-butyl methacrylate, t-butyl methacrylate, n-hexyl methacrylate, cyclohexyl methacrylate, n-octyl methacrylate, 2-ethylhexyl methacrylate , Dodecyl methacrylate, stearyl methacrylate. These may be used alone or in combination of two or more.

  Among these, alkyl methacrylate having an alkyl group having 2 to 6 carbon atoms is preferable, alkyl methacrylate having 4 alkyl atoms is more preferable, and i-butyl methacrylate is particularly preferable. When the carbon number of the alkyl group of the alkyl methacrylate (d1) is 2 or more, the dispersibility of the pigment (B) in the polyolefin resin (A) is excellent. Moreover, it is excellent in the powder handleability of a 2nd dispersing agent (D) as carbon number of an alkyl group is 6 or less. When the alkyl group has 4 carbon atoms, the dispersibility of the pigment (B) in the polyolefin resin (A) is further improved. When the alkyl group is i-butyl methacrylate, the dispersibility of the pigment (B) in the polyolefin resin (A) is particularly excellent.

  Examples of the other monomer (d2) used as the copolymerizable component include the following. Aromatic vinyl monomers such as styrene, α-methylstyrene and chlorostyrene; (meth) acrylic acid; n-butyl acrylate; methyl (meth) acrylate; vinyl cyanide monomers such as (meth) acrylonitrile; Vinyl ether monomers such as ether and vinyl ethyl ether; vinyl carboxylate monomers such as vinyl acetate and vinyl butyrate; olefins such as ethylene, propylene and butylene. These other monomers (d2) may be used individually by 1 type, and may use 2 or more types together.

  The content of the alkyl methacrylate (d1) unit having an alkyl group having 2 or more carbon atoms in the alkyl methacrylate polymer of the present invention is preferably 60% by mass or more, and more preferably 70% by mass or more. Preferably, it is 85 mass% or more. When the content of the alkyl methacrylate (d1) unit is 60% by mass or more, the dispersibility of the pigment (B) in the polyolefin resin (A) is excellent.

  In the second dispersant (D), the same alkyl methacrylate polymer may be used alone, or two or more polymers having different compositions, molecular weights, particle sizes, etc. may be used in combination. .

  The mass average molecular weight of the alkyl methacrylate polymer is preferably 10,000 to 2,000,000, more preferably 10,000 to 500,000, still more preferably 10,000 to 145,000, It is particularly preferably 20,000 to 130,000, and most preferably 25,000 to 100,000. When the mass average molecular weight of the alkyl methacrylate polymer is 15,000 or more, the powder dispersant of the second dispersant (D) is excellent. Further, when the alkyl methacrylate polymer has a mass average molecular weight of 2 million or less, the dispersibility of the pigment (B) in the polyolefin resin (A) is excellent. A method for measuring the weight average molecular weight of the alkyl methacrylate polymer will be described later.

  The content of the second dispersant (D) in the polyolefin resin composition is preferably 0.01 to 10 parts by mass, and 0.1 to 5 parts by mass with respect to 100 parts by mass of the polyolefin resin (A). More preferably, it is 0.2 parts by mass to 3 parts by mass. When the content of the second dispersant (D) is 0.01 parts by mass or more, the dispersibility of the pigment (B) in the polyolefin resin (A) is excellent. Moreover, the dispersibility of a pigment (B) can be improved, without changing the basic property of polyolefin resin as content of a 2nd dispersing agent (D) is 10 mass parts or less.

[Polymerization method]
Examples of the polymerization method of the alkyl methacrylate polymer of the present invention include known polymerization methods such as emulsion polymerization, soap-free emulsion polymerization, fine suspension polymerization, suspension polymerization, bulk polymerization, and solution polymerization. Among these polymerization methods, the alkyl methacrylate polymer is obtained in the form of powder or granules and is excellent in dispersibility of the second dispersant (D) in the polyolefin resin (A). A polymerization method, a soap-free emulsion polymerization method, and a suspension polymerization method are preferable, and an emulsion polymerization method is more preferable.

  The particle structure in the case of performing polymerization using a polymerization method capable of obtaining a particle structure such as emulsion polymerization or soap-free emulsion polymerization may be a single layer structure or a multilayer structure. When the particle structure is a multilayer structure, it is preferably a three-layer structure or less from the viewpoint of economy.

  As an emulsifier in the emulsion polymerization, a known emulsifier can be used, and examples thereof include an anionic emulsifier, a nonionic emulsifier, a polymer emulsifier, and a reactive emulsifier having an unsaturated double bond capable of radical polymerization in the molecule. .

Examples of the anionic emulsifier include the following. “New Call 560SF”, “New Call 562SF”, “New Call 707SF”, “New Call 707SN”, “New Call 714SF”, “New Call 723SF”, “New Call 740SF”, “New Call 2308SF”, “New Call "Call 2320SN", "New Call 1305SN", "New Call 271A", "New Call 271NH", "New Call 210", "New Call 220", "New Call RA331", and "New Call RA332" (all products "Latemul B-118E", "Lebenol WZ", and "Neopelex G15" (both trade names, manufactured by Kao Corporation); "Hitenol N08" (trade name, Daiichi Kogyo Seiyaku Co., Ltd.).
Examples of the nonionic emulsifier include “Nonipol 200” and “New Pole PE-68” (both trade names, manufactured by Sanyo Chemical Industries, Ltd.).
Examples of the polymer emulsifier include polyvinyl alcohol, polyhydroxyethyl (meth) acrylate, polyhydroxypropyl (meth) acrylate, and polyvinylpyrrolidone.
Examples of reactive emulsifiers include the following. “Antox MS-60” and “Antox MS-2N” (both trade names, manufactured by Nippon Emulsifier Co., Ltd.); “Eleminol JS-2” (trade names, manufactured by Sanyo Chemical Industries, Ltd.); -120 "," Latemul S-180 "," Latemul S-180A ", and" Latemul PD-104 "(all trade names, manufactured by Kao Corporation);" Adekaria Soap SR-10 "and" Adeka " Rear soap SE-10 (all trade names, manufactured by ADEKA Corporation); "Aqualon KH-05", "Aqualon KH-10", and "Aquaron HS-10" (all trade names, Daiichi Kogyo Seiyaku) Reactive anionic emulsifiers, etc. “Adekalia Soap NE-10”, “Adekalia Soap ER-10”, “Adekalia Soap NE-20”, “Adekalia Soap ER-20”, “Adekalia Soap NE-30”, “Adekalia Soap ER” -30 "," ADEKA rear soap NE-40 ", and" ADEKA rear soap ER-40 "(all trade names, manufactured by ADEKA Corporation);" AQUARON RN-10 "," AQUARON RN-20 "," Reactive nonionic emulsifiers such as Aqualon RN-30 and Aqualon RN-50 (both trade names, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.).
These emulsifiers may be used individually by 1 type, and may use 2 or more types together.

As the polymerization initiator, a known radical polymerization initiator can be used, and examples thereof include the following. Persulfate compounds such as potassium persulfate, sodium persulfate, ammonium persulfate; azobisisobutyronitrile, 2,2′-azobis (2-methylbutyronitrile), 2,2′-azobis (2,4 Oil-soluble azo compounds such as 2-dimethylvaleronitrile), 2,2′-azobis (4-methoxy-2,4-dimethylvaleronitrile), 2-phenylazo-4-methoxy-2,4-dimethylvaleronitrile; 2 , 2′-azobis {2-methyl-N- [1,1-bis (hydroxymethyl) -2-hydroxyethyl] propionamide}, 2,2′-azobis {2-methyl-N- [2- (1 -Hydroxyethyl)] propionamide}, 2,2′-azobis {2-methyl-N- [2- (1-hydroxybutyl)] propionamide}, 2,2′-azobis [2- (5 -Methyl-2-imidazolin-2-yl) propane] and salts thereof, 2,2′-azobis [2- (2-imidazolin-2-yl) propane] and salts thereof, 2,2′-azobis [2- (3,4,5,6-tetrahydropyrimidin-2-yl) propane] and salts thereof, 2,2′-azobis {2- [1- (2-hydroxyethyl) -2-imidazolin-2-yl] propane And its salts, 2,2′-azobis (2-methylpropionamidine) and its salts, 2,2′-azobis (2-methylpropionamidine) and its salts, 2,2′-azobis [N- (2 -Carboxyethyl) -2-methylpropionamidine] and water-soluble azo compounds thereof such as salts thereof; benzoyl peroxide, cumene hydroperoxide, t-butyl hydroperoxide, t-butyl Peroxy-2-ethylhexanoate, t- butyl peroxy isobutyrate or the like organic peroxides.
These radical polymerization initiators may be used alone or in combination of two or more. Moreover, when superposing | polymerizing by an emulsion polymerization method, reducing agents, such as sodium bisulfite, ferrous sulfate, ascorbate, can also be used in combination with the said radical polymerization initiator.

  The method for adjusting the mass average molecular weight of the polymer is not particularly limited, and examples thereof include a method for adjusting the amount of polymerization initiator used and a method for adjusting the amount of chain transfer agent used.

  Examples of the chain transfer agent include the following. Mercaptans such as n-dodecyl mercaptan, t-dodecyl mercaptan, n-octyl mercaptan, n-tetradecyl mercaptan, n-hexyl mercaptan, n-butyl mercaptan; halogen compounds such as carbon tetrachloride and ethylene bromide; α-methyl Styrene dimer. These chain transfer agents may be used individually by 1 type, and may use 2 or more types together. The amount of chain transfer agent used can be appropriately adjusted according to the mass average molecular weight of the alkyl methacrylate polymer, the type of chain transfer agent, the composition ratio of the monomers, and the like.

[Polymerization of polymer]
The polymer thus produced is usually recovered as a powder. The method for pulverizing the polymer is not particularly limited, and can be appropriately selected depending on the polymerization method. For example, examples of the powdering method in the case of emulsion polymerization include a coagulation method, a spray drying method, a centrifugal separation method, and a freeze drying method. Among these pulverization methods, the coagulation method and the spray drying method are preferable from the viewpoint of the homogeneity of the powder.

  When a polymer latex is pulverized using a coagulation method, the latex is brought into contact with a coagulant at 30 to 90 ° C., coagulated with stirring to form a slurry, and dehydrated and dried to obtain a powder. be able to. Examples of the coagulant include inorganic acids such as hydrochloric acid, sulfuric acid, nitric acid, and phosphoric acid; organic acids such as formic acid and acetic acid; inorganic salts such as aluminum sulfate, magnesium sulfate, and calcium sulfate; and organic salts such as calcium acetate. .

  When the polymer latex is pulverized using the spray drying method, the latex can be spray-dried under conditions of an inlet temperature of 120 to 220 ° C and an outlet temperature of 40 to 90 ° C to obtain a powder. The outlet temperature is preferably 40 to 80 ° C, and more preferably 40 to 70 ° C, from the viewpoint of pulverization of the polymer powder into primary particles.

In addition to the alkyl methacrylate polymer, the second dispersant (D) is a filler, a flame retardant, a stabilizer, a crystal nucleating agent, a foaming agent, as long as the original properties of the polyolefin resin (A) are not impaired. You may further mix | blend various additives, such as blocking prevention and antistatic.
The content of various additives is preferably 30% by mass or less, more preferably 10% by mass or less, in 100% by mass of the total amount of the second dispersant (D). When the content of the various additives is 30% by mass or less, the dispersibility of the pigment (B) in the polyolefin resin (A) is excellent.

[Polyolefin resin composition]
The polyolefin resin composition of this invention can be obtained by mixing each structural component. As a mixing method, known melt-kneading methods such as extrusion kneading and roll kneading can be used. The melt kneading method is not particularly limited, and the polyolefin resin (A), the pigment (B), the first dispersant (C) and the second dispersant (D) can be melt kneaded at the same time. Further, after mastering a master batch by melting and kneading the whole amount of the pigment (B), the first dispersant (C) and the second dispersant (D) and a part of the polyolefin resin (A), the master The batch and the remainder of the polyolefin resin (A) can be melt-kneaded. The melt kneading temperature can be appropriately set according to the type of the polyolefin resin (A). The melt kneading temperature is preferably 160 to 280 ° C, and more preferably 180 to 240 ° C.

The polyolefin resin composition of the present invention may further contain additives such as a filler, a flame retardant, a stabilizer, a crystal nucleating agent, a foaming agent, antiblocking, and antistatic, as necessary.
The content of these additives in the polyolefin resin composition is preferably 0.01 to 10 parts by mass with respect to 100 parts by mass of the polyolefin resin (A). When the content of these additives is 0.01 parts by mass or more, the effects of various additives are excellent, and when the content is 10 parts by mass or less, the original characteristics of the resulting polyolefin resin composition are not impaired.

[Molded body]
The molded product of the present invention is obtained by molding the polyolefin resin composition of the present invention. As a molding method of the molded body, a known molding method can be used, and examples thereof include methods such as extrusion molding, injection molding, calendar molding, blow molding, thermoforming, foam molding, and melt spinning.

  The molded body of the present invention is suitable for a sheet material such as an optical sheet, a film material such as a food film, an automobile member, a household appliance member, a medical member, and a building member.

    Hereinafter, the present invention will be described by way of examples. “Parts” and “%” in the examples indicate “parts by mass” and “% by mass”. Prior to the examples, various evaluation methods and methods for producing a dispersant will be described.

(1) Mass average molecular weight The tetrahydrofuran soluble part of the alkyl methacrylate polymer was used as a sample and subjected to molecular weight measurement using gel permeation chromatography (GPC).
The measurement conditions of GPC are as follows, and the mass average molecular weight was determined from a calibration curve using standard polystyrene.
Equipment: “HLC8220” manufactured by Tosoh Corporation
Column: “TSKgel SuperMultipore HZ-H” manufactured by Tosoh Corporation (inner diameter 4.6 mm × length 15 cm × 2, exclusion limit 4 × 10 ⁷ (estimated)),
Eluent: THF,
Eluent flow rate: 0.35 ml / min,
Measurement temperature: 40 ° C.
Sample injection volume: 10 μl (sample concentration 0.1%).

(2) Dispersibility of pigment (number of undispersed pigments)
A sheet molded body (width 80 mm, length 300 mm, thickness 0.3 mm) was observed with a stereomicroscope for an area of 1000 cm ² (arbitrary portion of width 5 cm, length 20 cm, 10 locations), and length of 200 μm. The number of undispersed pigments in excess of was counted. The average value of the number of undispersed materials per 100 cm ² was determined, and the dispersibility was evaluated according to the following criteria.
A: The number of undispersed pigments is 5/100 cm ² or less.
B: Not dispersion number of the pigment exceeds 5/100 cm ^2, 10 or / 100 cm ² or less.
C: The number of undispersed pigments exceeds 10/100 cm ² .

(3) Productivity of molded product (discharge amount of sheet molded product)
At the time of sheet forming, a molded product produced per minute was collected, and the discharge amount (g / min) was determined from the mass. Under the same molding conditions, the higher the discharge rate, the better the productivity.

(4) Appearance of molded product (color unevenness)
The appearance of the obtained sheet molded body was visually evaluated according to the following criteria.
A: Color unevenness is not recognized in the sheet molding.
B: Color unevenness is observed in the sheet molding.

[Production Example 1]
In a separable flask (capacity 5 liters) equipped with a thermometer, a nitrogen introduction tube, a cooling tube and a stirrer, 300 parts (3000 grams) of ion-exchanged water, 98 parts of i-butyl methacrylate, 2 parts of n-butyl acrylate, n -1 part of octyl mercaptan and 1.1 parts of sodium dodecylbenzenesulfonate were added, and the atmosphere in the flask was replaced with nitrogen by passing a nitrogen stream through the separable flask. Next, the internal temperature was raised to 60 ° C., and 0.15 part of potassium persulfate and 5 parts of deionized water were added. Thereafter, heating and stirring were continued for 2 hours to complete the polymerization, and an alkyl methacrylate polymer latex was obtained.
The resulting latex was cooled to 25 ° C. Thereafter, this latex was dropped into a 70 ° C. solution containing 5 parts of calcium acetate and 495 parts of water, and the temperature of the solution was raised to 90 ° C. to coagulate the polymer. The obtained coagulated product was separated, washed with water, and then dried at 60 ° C. for 12 hours to obtain an alkyl methacrylate polymer powder. This powder was used as a dispersant (D1). The results of measuring the weight average molecular weight of this dispersant (D1) are shown in Table 1.

[Production Examples 2 to 5]
An alkyl methacrylate polymer was obtained in the same manner as in Production Example 1 except that the composition of the monomer component and the amount of the chain transfer agent were changed as shown in Table 1.
The obtained alkyl methacrylate polymer powder was used as dispersants (D2) to (D5). Table 1 shows the results obtained by measuring the mass average molecular weights of the dispersants (D2) to (D6).

The abbreviations in Table 1 are as shown below.
i-BMA: i-butyl methacrylate n-BMA: n-butyl methacrylate n-BA: n-butyl acrylate MMA: methyl methacrylate

[Example 1]
Polypropylene resin “NOVATEC-PP FY-4” (trade name, manufactured by Nippon Polypro Co., Ltd., melt flow rate: 5 g / 10 min) as polyolefin resin (A), and blue pigment “Ultramarine 1900” as pigment (B) (Trade name, manufactured by Daiichi Kasei Kogyo Co., Ltd.) 0.5 part, 0.2 part of calcium stearate as the first dispersant (C), and dispersant (D1) 0.002 as the second dispersant (D). Three parts were blended and mixed by hand blend to prepare a polyolefin resin composition. Thereafter, in a φ25 mm single screw extruder (model name “TP-25”, manufactured by Thermo Plastics Industries, Ltd., L / D = 20) equipped with a T die mold (width 100 mm, lip interval 0.5 mm) This resin composition was supplied and extrusion molded under the conditions of a screw speed of 30 rpm and a cylinder temperature of 190 ° C. to obtain a sheet molded body.
Table 2 shows the evaluation results of the productivity of the sheet molded body, the dispersibility of the pigment in the sheet molded body, and the appearance of the sheet molded body. The abbreviations described in Table 2 indicate the compounds in Table 3.

[Examples 2 to 7 and Comparative Examples 1 to 4]
A sheet molded body was obtained in the same manner as in Example 1 except that the composition of the resin composition was changed to the values shown in Table 2. The evaluation results are shown in Table 2.

  As is clear from Table 2, in Examples 1 to 7 using the polyolefin resin composition of the present invention, the sheet molded article has excellent pigment dispersibility and high productivity, and the sheet molded article has uneven color. There was no appearance. On the other hand, in the comparative example 1 which does not contain the 1st dispersing agent (C), color unevenness was recognized by the sheet molded object and the external appearance was inferior. In addition, the sheet molded bodies obtained in Comparative Examples 2 to 4 that did not contain the second dispersant (D) had poor pigment dispersibility and poor productivity.

  A molded product obtained by molding the polyolefin resin composition of the present invention has excellent pigment dispersibility, high productivity, and excellent appearance without color unevenness, such as toys, stationery and other miscellaneous goods, packaging materials, It is suitable for food containers, medical materials, building materials, automobile parts, OA equipment, home appliances and the like.

Claims (5)

A polyolefin resin composition comprising a polyolefin resin (A), a pigment (B), a first dispersant (C) and a second dispersant (D), wherein the first dispersant (C) is a fatty acid metal salt The second dispersant (D) includes an alkyl methacrylate polymer containing 50% by mass or more of an alkyl methacrylate (d1) unit having an alkyl group having 2 or more carbon atoms , and the first dispersant the content of (C) is, relative to the polyolefin resin (a) 100 parts by mass of, Ru 0.01 to 5 mass parts der polyolefin resin composition.   The polyolefin resin composition according to claim 1, wherein the alkyl methacrylate polymer has a mass average molecular weight of 10,000 to 2,000,000.   The polyolefin resin composition according to claim 1 or 2, wherein the (d1) unit is an alkyl methacrylate unit having an alkyl group having 4 carbon atoms.   The polyolefin resin composition according to any one of claims 1 to 3, wherein the (d1) unit is an i-butyl methacrylate unit.   The molded object obtained by shape | molding the polyolefin resin composition as described in any one of Claims 1-4.