JP2006298983A - Granular chromatic colored resin composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technique for suppressing generation of a molded product having defective external appearances caused by formation of colored resin deformed matter or by contamination with solid foreign matter in the manufacture of a resin molded product used for various applications by molding a chromatic colored thermoplastic resin composition. <P>SOLUTION: The granular chromatic colored resin composition for manufacturing the resin molded product is obtained by adding a white pigment, and preferably further a small amount of a black pigment to a mixture of an unused thermoplastic resin component and a chromatic colored pigment and subsequently granulating, and a sheet prepared from the resin composition has a lightness (L<SP>*</SP>) and a light transmittance satisfying the relationship of the formula: 1,300≤(L<SP>*</SP>×B)≤4,000 [wherein L<SP>*</SP>is a lightness of the sheet having a thickness of 3 mm prepared from the resin composition; and B is a total light transmittance (%) of the sheet having a thickness of 50 μm prepared from the resin composition]. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention provides various chromatic colors such as resin moldings for electrical products, resin moldings for storage containers, resin moldings for office equipment, automobile bumpers, automotive interior parts, and automotive molded parts such as automotive exterior parts. The present invention relates to a granular chromatic resin composition that is advantageously used in the production of a resin molded product.

  Room cooler outdoor unit housing, room cooler wind vane, washing machine base, washing tub, balancer, exterior panel, refrigerator lower grill, transport handle, evaporating dish, food storage case, small refrigerator upper table, copier Various chromatic resin moldings such as panels, housings, paper trays, automobile bumpers, automobile interior parts, and automobile exterior parts are usually used in thermoplastic resins such as unused polyolefin resins and ABS resins. Thermoplastic resin composition prepared by adding coloring pigments and, if necessary, additional components such as fillers and elastomer resins (raw material compositions composed of such unused materials are usually called virgin materials) (E.g., powder, pellets, flakes, granules, pulverized products) are heated and melted and introduced into a forming die, and then cooled. It has been produced by. In such a granular product manufacturing process or molded product molding process, a colored resin modified product may be formed by local overheating of the resin melt and mixed into the molded product, and may float in the air. Or fine solid foreign substances adhering to the molding machine may be mixed into the raw resin granules or the resin melt and get mixed into the molded product. When these resin-modified products and solid foreign substances are mixed in the resin molding beyond a certain level, the presence of the colored resin-modified products and solid foreign bodies will appear on the surface of the molding. In particular, since such colored resin-modified products and solid foreign substances are often dark, they are easily noticeable when mixed in a relatively light-colored resin molded product. In addition, an electric product, a stored product, office supplies, or an automobile part in which a resin molded product in which contamination of a colored resin or a solid foreign substance has been manifested on the surface is mounted as a constituent member is not preferable because its commercial value is low. Therefore, resin molded products with colored resin modified products or solid foreign substances appearing on the surface are usually coated on the surface where the foreign substances are exposed, and the foreign matter is covered with the coating film, or defective products are used. As a raw material for resin moldings that are not a problem even if such resin-modified products or solid foreign substances are mixed on the surface of the molding are being studied.

  On the other hand, the demand for recycling of various materials in recent years has increased, and resin products that make up electrical products, automobile parts or office supplies are also required to be highly recycled. Manufacturers, manufacturers of resin moldings to be mounted on electrical products, automobiles and office supplies, material manufacturers supplying materials for those resin moldings, and companies that dispose of used electrical products, automobiles and office supplies Each company is working on recycling of various resin materials. Such recycling objects are roughly classified into defective products (usually called process defective products) generated during the production of the above-mentioned resin molded products, and the molded products are actually used as electrical products, automobile parts or office supplies. It is divided into collected products separated from electrical products, automobile parts, office supplies, etc. that are used by the company and then disposed of.

  In Patent Document 1, a pulverized product of a thermoplastic resin product containing a black pigment, a mixture of a pulverized product of a thermoplastic resin product containing a black pigment and a pulverized product of a thermoplastic resin product containing a chromatic pigment, or Prepare a heated melt by mixing and heating a white pigment and a chromatic pigment to a pulverized product of two or more kinds of chromatic pigments having different hues, and then heating the solid melt into a solid particulate form. A method for producing a chromatic color regenerated resin granular material by converting to a product is disclosed.

  In Patent Document 2, a small amount of a cured resin is mixed, and a light-shielding material such as a white pigment, a black pigment, or a chromatic pigment is added to a pulverized thermoplastic resin product containing a black pigment or a chromatic pigment. 1 type or two or more types of conductive pigments are mixed to prepare a heated melt, and then the heated melt is converted into a solid granular material, so that a thermoplastic resin product with a film such as an automobile bumper is applied to the surface coating. There is a disclosure that a recycled resin granular material that can be reused in many directions can be obtained without removing.

WO 03/095531 A1 brochure WO 03/089500 A1 brochure

  Regarding the resin product pulverized product obtained by recovering and pulverizing the thermoplastic resin product containing the black pigment or the chromatic pigment, it is necessary to carry out a regeneration operation as described in Patent Documents 1 and 2 above. At the same time, it has been found that it can be reused by utilizing a method of regenerating by additionally adding a light shielding pigment.

  However, in the known method, the light shielding pigment to be added while recognizing the state of contamination of the crushed thermoplastic resin product by solid foreign matters at the time of the regeneration operation of the pulverized thermoplastic resin product. There is a complication that the type and amount of addition must be determined.

  The main object of the present invention is to mold a chromatic thermoplastic resin composition (virgin material) to produce a chromatic colored resin molded product used as a component of electrical products, automobile parts, office supplies, etc. An object of the present invention is to provide a technique capable of suppressing the generation of a molded article having a defective appearance, which has been conventionally discarded as a defective process product, due to the formation of a colored resin-modified product generated during the process and the mixing of solid foreign substances.

  It is another object of the present invention to add a new light-shielding pigment or to add a new light-shielding pigment when reusing a pulverized product of used chromatic thermoplastic resin products. It also provides technology that does not require fine adjustment.

  The inventor of the present invention usually uses a white pigment (preferably when producing a granular resin composition prepared by adding a filler and a chromatic pigment to an unused thermoplastic resin component such as polyolefin resin or ABS resin. (In combination with a small amount of black pigment) under certain conditions, even if a small amount of colored resin-modified product or solid foreign matter is mixed in the molded product produced by heating and melting, mixing them It has been found that it is possible to prevent (invisibility) the material from appearing on the surface of the resin molded product from which the product is obtained.

The present invention relates to a granular chromatic resin composition comprising an unused thermoplastic resin component, a chromatic pigment, and a white pigment, and the brightness (L ^* ) and light transmittance of a sheet prepared from the resin composition The granular chromatic resin composition is characterized in that the relationship satisfies the following formula.

1300 ≦ (L ^* × B) ≦ 4000

However, L ^* is the brightness of a sheet having a thickness of 3 mm prepared from the resin composition, and B is the total light transmittance (%) of a sheet having a thickness of 50 μm prepared from the resin composition.

  The present invention also resides in a chromatic color resin molded product obtained by heating and melting the granular chromatic color resin composition described above and then molding.

Preferred embodiments of the granular chromatic resin composition of the present invention are as follows.
(1) The granular chromatic color resin composition further contains a black pigment.
(2) The granular chromatic color resin composition contains a filler.
(3) The thermoplastic resin component is mainly composed of polyolefin.
(4) The total light transmittance represented by B of the sheet prepared from the granular chromatic resin composition of the present invention is in the range of 15 to 60% (more preferably in the range of 18 to 55, more preferably in the range of 20 to 50). , Particularly preferably in the range of 25 to 48).
(5) The content of the white pigment in the granular chromatic resin composition of the present invention is 1% by mass or more and 20% by mass or less (more preferably in the range of 1 to 20% by mass, more preferably 1.5 to 18% by mass). %, Particularly preferably in the range of 2 to 15% by mass, most preferably in the range of 3 to 12% by mass).
(6) The white pigment contained in the granular chromatic resin composition of the present invention is titanium dioxide.
(7) The content of the black pigment in the granular chromatic resin composition of the present invention is 0.01% by mass or more and 1.0% by mass or less (more preferably in the range of 0.05 to 0.8% by mass, More preferably, it is in the range of 0.01 to 0.5 mass%, particularly preferably in the range of 0.012 to 0.3 mass%, and the content of the black pigment is less than the content of the white pigment.
(8) The black pigment contained in the granular chromatic resin composition of the present invention is iron black.
(9) The whiteness of a 3 mm thick sheet prepared from the granular resin composition of the present invention is less than 55.
(10) (L ^* × B) is 1300 or more and 4000 or less (preferably 1500 to 4000, more preferably 1800 to 4000, particularly preferably 2000 to 3800).

  By using the granular chromatic resin composition of the present invention, conventionally, when a granular chromatic resin composition (virgin material) is thermoformed to produce a resin molded product, a colored resin-modified product is formed or a solid foreign substance is mixed. It is possible to suppress the generation of a molded article having a defective appearance that has been generated by the process and discarded as a defective product.

  Furthermore, the chromatic resin molded product produced using the granular chromatic resin composition of the present invention does not require the addition of a new light-shielding pigment when reusing the pulverized product after use. Alternatively, fine adjustment of the amount of new light-shielding pigment added becomes unnecessary.

  The granular chromatic resin composition of the present invention contains an unused thermoplastic resin component such as an unused polyolefin resin or ABS, a chromatic pigment and a white pigment, and preferably further contains a black pigment. Furthermore, a filler may be contained. Further, the thermoplastic resin component may contain an elastomer resin.

  Examples of thermoplastic resins include polyolefin resins, ABS resins, polycarbonate resins, polyurethane resins, styrene resins, ABS resins (acrylonitrile-butadiene-styrene resins), polyester resins such as polybutylene terephthalate and polyethylene terephthalate, modified Polyphenyl ether resins such as polyphenylene ether and polyphenylene sulfide, polyacrylic acid resins such as polymethyl methacrylate, polyamide resins such as 6-nylon, 66-nylon, 12-nylon and 6 / 12-nylon, polysulfone And so on.

  Examples of polyolefin resins include polypropylene resins such as crystalline polypropylene, polyethylene resins such as high density polyethylene and low density polyethylene, and mixtures of these resins.

  The elastomer resin is a thermoplastic low crystalline elastomer that does not have a clear yield point or a thermoplastic amorphous elastomer resin that does not have a clear melting point and yield point and has rubber elasticity at room temperature. Can be used. Specific examples of the elastomer that can be used include thermoplastic elastomers such as styrene elastomers, olefin elastomers, polyester elastomers, polyamide elastomers, and polyurethane elastomers. Elastomer resins may be used alone or in combination of two or more.

  If desired, when the granular chromatic resin composition of the present invention is produced, a recycled resin component may be used in a relatively small amount mixed with an unused thermoplastic resin component (virgin material). Good.

  As a filler used when making a granular chromatic resin composition contain a filler, an organic filler and an inorganic filler except a pigment can be used, but an inorganic filler is preferable. These fillers are preferably light shielding fillers. The filler is preferably added in an amount of 40 parts by mass or less with respect to 100 parts by mass of the thermoplastic resin component.

  Inorganic fillers include talc, clay, mica, silica, diatomaceous earth, moss heidi, tismo, wollastonite, montmorillonite, bentonite, dolomite, dosonite, silicates, carbon fiber, glass fiber, barium ferrite, beryllium oxide, water Aluminum oxide (magnesium hydroxide, basic magnesium carbonate, calcium carbonate, magnesium carbonate, magnesium sulfate, calcium sulfate, barium sulfate, ammonium sulfate, calcium sulfite, calcium oxalate, molybdenum sulfide, zinc borate, barium metaborate, calcium borate , Sodium borate, or zinc, copper, iron, lead, aluminum, nickel, chromium, titanium, manganese, tin, platinum, tungsten, gold, magnesium, cobalt, strontium And metal oxides of these metals, alloys such as stainless steel, solder and brass, powders of metal ceramics such as silicon carbide, silicon nitride, zirconia, aluminum nitride and titanium carbide, fibrous whiskers and fibers, etc. Particularly preferred are talc and mica.

  Known pigments can be used without limitation, for example, inorganic pigments such as metal oxides, hydroxides, sulfides, chromates, carbonates, sulfates and silicates; azo series, diphenylmethane series And organic pigments such as triphenylmethane, phthalocyanine, nitro, nitroso, anthraquinone, quinacridone red, benzidine, and condensed polycyclic. Further, it may be colored fibers or glossy metal particles. There is no restriction | limiting in particular about the hue of a chromatic color pigment, Any things, such as yellow, blue, red, and green, can be used. Two or more kinds of these pigments can be used in combination.

  Specific examples of chromatic pigments that can be used in the present invention include inorganic pigments such as petals, ultramarine blue, cobalt blue, titanium yellow, bitumen, zinc sulfide, barium yellow, cobalt blue, and cobalt green; quinacridone red, polyazo Yellow, anthraquinone red, anthraquinone yellow, polyazo red, azo lake yellow, berylene, phthalocyanine blue, phthalocyanine green, isoindolinone yellow, watching red, permanent red, para red, toluidine maroon, benzidine yellow, first sky blue, brilliant carmine 6B Organic pigments such as, colored fibers, glossy metal particles, and the like. These pigments can be used in combination of two or more.

  The average particle diameter of titanium yellow is not particularly limited, but is preferably 0.1 to 1.5 μm, more preferably 0.5 to 1.3 μm, more preferably 0.7 to 1.1 μm, and particularly 0.8 to 1 μm. Is preferable because it is excellent in dispersibility, handleability, and workability. The DOP oil absorption amount of titanium yellow is not particularly limited, but is preferably 15 to 40 (cc / 100 g), more preferably 20 to 35 (cc / 100 g), and particularly preferably 20 to 30 (cc / 100 g). It is. The pH of titanium yellow is not particularly limited, but is preferably in the range of 6 to 10, particularly preferably 7 to 9.

  As the ultramarine, those conventionally used for pigments can be used without limitation. The average particle diameter of ultramarine is not particularly limited, but is preferably 0.1 to 5 μm, more preferably 0.5 to 4 μm, more preferably 0.8 to 3.5 μm, and particularly preferably 1 to 3 μm. . These are preferable because they are excellent in dispersibility, handleability and workability. The DOP oil absorption amount of ultramarine is not particularly limited, but is preferably 20 to 50 (cc / 100 g), more preferably 25 to 40 (cc / 100 g), and particularly preferably 30 to 35 (cc / 100 g). The pH of ultramarine is not particularly limited, but is preferably in the range of 5 to 11, more preferably 5.5 to 11, and particularly preferably 7 to 11.

  As the phthalocyanine blue, those conventionally used for pigments can be used without limitation, and those produced by, for example, the Waller method or the phthalonitrile method can be used. The particle shape of phthalocyanine blue is not particularly limited, but α type, β type, and the like can be used. The average particle size of phthalocyanine blue is not particularly limited, but is preferably 0.01 to 2 μm, more preferably 0.05 to 1.5 μm, more preferably 0.1 to 0.4 μm, and particularly preferably 0.1 to 1 μm. Range.

  As the phthalocyanine green, those conventionally used for pigments can be used without limitation, and for example, those produced by the Waller method or the phthaloetril method can be used. The particle shape of phthalocyanene green is not particularly limited, and α-type, β-type, and the like can be used. The average particle size of phthalocyanine green is not particularly limited, but is preferably 0.01 to 2 μm, more preferably 0.05 to 1.5 μm, more preferably 0.1 to 0.4 μm, and particularly preferably 0.1 to 0.1 μm. The range is 1 μm. The pH of phthalocyanine green is not particularly limited, but is preferably 4 to 9, and more preferably 4 to 8.

  As the petal, those conventionally used for pigments can be used without limitation. The particle shape of the petal is not particularly limited, but an equiaxed crystal system or the like can be used. The average particle diameter of the petal is not particularly limited, but is preferably 0.01 to 1 μm, more preferably 0.05 to 0.5 μm, more preferably 0.08 to 0.4 μm, and particularly preferably 0.1 to 0.1 μm. The range is 0.3 μm. The amount of DOP oil absorption of the petal is not particularly limited, but is preferably 10 to 50 (cc / 100 g), more preferably 12 to 40 (cc / 100 g), and particularly preferably 15 to 30 (cc / 100 g). is there. The pH of the valve is not particularly limited but is preferably in the range of 4-8, more preferably 5-7.

  As quinacridone red, those conventionally used for pigments can be used without limitation. The particle shape of quinacridone red is not particularly limited, and α-type, β-type, γ-type and the like can be used. The average particle size of quinacridone red is not particularly limited, but is preferably 0.01 to 2 μm, more preferably 0.05 to 1.5 μm, and particularly preferably 0.1 to 1 μm. As anthraquinone red, those conventionally used for pigments can be used without limitation. The average particle size of anthraquinone red is not particularly limited, but is preferably 0.01 to 2 μm, more preferably 0.05 to 1.5 μm, and particularly preferably 0.1 to 1 μm. Although not limited to the pH of anthraquinone red, it is preferably in the range of 4-9.

  Examples of white pigments include titanium dioxide, white lead, and zinc oxide. Particularly preferred is titanium dioxide.

  As titanium dioxide, those conventionally used for pigments can be used, and for example, those produced by the chlorine method or sulfuric acid method can be used. The thing manufactured by the chlorine method is preferable. The particle shape is not particularly limited, but tetragonal, rutile, and anatase types can be used, and tetragonal and rutile types are particularly preferable. The average particle diameter is not particularly limited, but is preferably 0.01 to 0.5 μm, more preferably 0.05 to 0.5 μm, more preferably 0.1 to 0.4 μm, and particularly preferably 0.2 to 0.00. 3 μm particles are excellent in dispersibility, handleability and workability. The DOP oil absorption amount of titanium dioxide is not particularly limited, but is preferably 5 to 40 (cc / 100 g), more preferably 8 to 30 (cc / 100 g), more preferably 10 to 20 (cc / 100 g), particularly preferably. Is 12 to 18 (cc / 100 g). Two or more types of white pigments can be used in combination.

  Examples of the black pigment include carbon black and iron black. The black pigment can impart high light shielding properties to the resin molded product. Two or more black pigments can be used in combination.

  As the carbon black, those conventionally used for pigments can be used. For example, carbon black, acetylene black, lamp black, channel black, ketjen black, etc. produced by the furnace method or the channel method are used. Can do. Carbon black can be oxidized. As the carbon black, it is particularly preferable to use furnace black produced by the furnace method because it has excellent appearance uniformity and dispersibility, and the effects of improving the blackness and gloss of the resulting molded product are large. The average particle size of carbon black is not particularly limited, but is preferably 0.001 to 0.3 μm, more preferably 0.005 to 0.2 μm, more preferably 0.01 to 0.1 μm, and particularly preferably 0.00. Those having a thickness of 01 to 0.03 μm are preferable because they are excellent in dispersibility, handleability, and workability, and exhibit high effects in improving blackness and gloss.

  As the iron black, black iron oxide obtained by a firing method can be used. The particle shape of the iron black is not particularly limited, but a polyhedral shape such as an octahedron, a spherical shape, and the like can be used, and an octahedron is particularly preferable. The average particle size of iron black is not particularly limited, but is preferably 0.05 to 0.4 μm, more preferably 0.15 to 0.35 μm, and particularly preferably 0.2 to 0.35 μm. The DOP oil absorption amount of iron black is not particularly limited, but is preferably 10 to 80 (cc / 100 g), more preferably 15 to 50 (cc / 100 g), more preferably 20 to 40 (cc / 100 g), and particularly preferably. Is in the range of 25-35 (cc / 100 g). The pH of the iron black is not limited, but is preferably 9 to 11, and particularly preferably 9 to 10.

  The black pigment added to the granular chromatic resin composition of the present invention is preferably iron black, which is weaker in black color than carbon black. That is, iron black having such characteristics can be easily adjusted to an appropriate brightness and light transmittance by adjusting the amount of addition.

  If desired, the granular chromatic resin composition of the present invention may further contain various resin additives (eg, dispersants such as calcium stearate, lubricants, antistatic agents, surfactants, nucleating agents, ultraviolet absorbers, oxidation agents). Inhibitors, flame retardants) can also be added.

  Other additive components such as chromatic pigments, white pigments, and black pigments to be added as desired may be added directly to unused thermoplastic resin components as they are, or a resin composition containing a high concentration pigment in advance ( After preparing a master batch, a method of mixing with a resin composition to which no pigment is added (master batch technology) may be used. A masterbatch technique using various pigments and resin components is already known.

The example of the manufacturing method of the granular chromatic resin composition of this invention is shown below.
(1) Add the chromatic color pigment and white pigment, which are estimated to be appropriate amounts, to the unused particles of the thermoplastic resin component, and optionally black pigment, and add fillers and various resin additives as necessary. To obtain a granular chromatic resin composition as a mixture.
(2) The above mixture is melt-kneaded, and then sheet-like test pieces for measuring lightness and light transmittance are produced directly or via a granular material.
(3) The lightness and light transmittance of the sheet-like test piece are measured, and the results of the measurement are compared with the conditions shown in the above formulas. Judging. If the product of lightness and light transmittance (%) of the test piece exceeds 4000, or less than 1300, change the type and amount of chromatic pigment, white pigment, black pigment, etc. as appropriate. Returning to the step (1). When the product of the lightness and light transmittance (%) of the test piece is 1300 or more and 4000 or less, it is used as a granular chromatic resin composition according to the present invention.
By performing the above operations, a granular chromatic resin composition that can be used for molding having a desired color tone, appearance, and physical properties can be produced.

  In the present invention, there are no particular limitations on the mixing method, mixing device, and mixing equipment of the unused thermoplastic resin component granules and each additive component, and there are no particular restrictions on the known single-screw extruder (kneader), twin-screw extruder. (Kneading machine), mixing and / or kneading of tandem type kneaders, calenders, Banbury mixers, kneading rolls, brabenders, plastographs, kneaders, etc., in which a twin screw extruder and a single screw extruder (kneader) are connected in series A device or the like can be used.

  The granular chromatic resin composition of the present invention is a chromatic color for various applications using known molding and molding methods such as extrusion molding, sheet molding, injection molding, injection compression molding, gas injection injection molding, probe molding, and vacuum molding. It can be used for the production of a resin molded product.

  Further, from the granular chromatic color resin composition of the present invention, a chromatic color resin molding having a glossy surface, a chromatic color resin molding having irregularities and patterns such as a drawing, or a chromatic color resin molding having smooth irregularities and patterns. A chromatic resin molded product having an arbitrary surface state such as a product can be obtained. The granular chromatic resin composition of the present invention is intended for those having a whiteness of less than 55.

  EXAMPLES Hereinafter, although an Example and a comparative example are given and this invention is demonstrated, this invention is not limited to these Examples.

(1) Measurement of whiteness and hue Using an injection molding machine with resin pellets having a clamping force of 130 tons, mold: square plate (100 mm x 100 mm x 3 mm; single side: skin pattern, single side: mirror surface), molding temperature: C1-C2-C3-C4 = 180-190-200-210 ° C., injection pressure: P1-P2-P3-P4 = 108-98-88-78 MPa, injection speed: V1-V2-V3-V4 = 30-30 A test piece (thickness: 3 mm) was molded under injection conditions of −20 to 20%, screw back pressure: free, screw rotation speed: 60%, mold temperature: 40 ° C., cycle: injection 10 seconds, and cooling 20 seconds. Measure the L ^* , a ^* , b ^* , L, a, and b using the SM-4 colorimeter of Suga Test Instruments Co., Ltd. Lightness and hue were obtained.

(2) Measurement of light transmittance Using a hot press molding machine with a clamping force of 40 tons, a resin pellet is sandwiched between photographic ferrotype plates (spacer: 70 × 50 × 0.05 mmt), heating plate temperature is 230 ° C., preheating time 2 minutes, defoaming treatment time 1 minute, pressurization time 1 minute (pressure: 100 kg / cm ² ), cooling temperature 20 ° C, cooling time 2 minutes. A test specimen was obtained.
The total light transmittance was measured for this test piece using a turbidimeter (turbidimeter NDH2000 manufactured by Nippon Denshoku Industries Co., Ltd.), and the total light transmittance (%) was defined as the light transmittance (%). The light source used was a halogen lamp rating of 5V9W, the light entrance opening diameter was 20 mmφ, and five points of the film were measured and averaged.

(3) Preparation of test piece and appearance evaluation method of drawn surface 0.05 parts by mass of iron powder having an average particle size of 0.3 mm is added to 100 parts by mass of resin pellets, and dried for 5 minutes using a platter manufactured by Platec. Blended. Next, a test piece (100 mm × 100 mm × 3 mm, one surface having a skin-like shape and the other surface having a mirror surface) is molded under the above injection molding conditions. Whether or not the presence of the powder was conspicuous in appearance was determined by visual observation. The visual observation results were evaluated in three stages according to the following criteria.
1: Presence of solid foreign matter on both the mirror surface and the skin-squeezed surface is visible (failed)
2: The presence of solid foreign matter is visible on the mirror surface, but the presence of solid foreign matter is hardly visible on the skin-squeezed surface (pass)
3: The presence of solid foreign matter is not visible on both the mirror surface and the leather surface (pass)

<Materials used>
(1) Polyolefin resin: crystalline polypropylene (virgin resin, MFR = 30 g / 10 min, ethylene / propylene block copolymer having an ethylene content of 7% by mass)
(2) White pigment: Titanium dioxide (addition amount is described in Table 1 as mass% with respect to polyolefin resin)
(3) Chromatic pigments: petal, ultramarine, isoindoline A (Ciba Specialty Chemicals, Chromophthal Orange 2G), isoindoline B (Ciba Specialty Chemicals, Irgazine Yellow 3RLT-N) (addition amount relative to polyolefin resin) (The mass% is described in Table 1)
(4) Black pigment: Iron black (added amount is listed in Table 1 as mass% with respect to polyolefin resin)
(5) Dispersant: Calcium stearate (added amount is listed in Table 1 as mass% with respect to polyolefin resin)
(6) Antioxidant: Irgaphos 168 (addition amount is described in Table 1 as mass% with respect to polyolefin resin)

[Examples 1-3, Comparative Examples 1-3]
<Manufacture of resin pellets>
To 100 parts by weight of polyolefin resin, white pigment, black pigment, chromatic color pigment, dispersant, and antioxidant are added in the amounts shown in Table 1, and after dry blending using a Platec tumbler, Using an axial kneader (UME 40-48T, manufactured by Ube Industries), melt kneading was performed under conditions of a barrel temperature of 220 ° C. and a throughput of 60 kg / hour to obtain resin pellets.

Table 1
────────────────────────────────────
Comparative Examples Comparative Examples Examples Examples Comparative Examples Examples
1 2 1 2 3 3
────────────────────────────────────
Color Colorless Orange Orange Orange Blue Blue────────────────────────────────────
<Pigment addition amount>
Petal----0.008 0.008
Ultramarine----0.250 0.550
Iron black---0.030 0.020 0.100
Titanium dioxide-0.400 1.920 12.000 0.100 1.070
Isoindoline A-0.040 0.070 0.660--
Isoindoline B-0.150 0.480 3.400--
Dispersant 0.100 0.100 0.100 0.100 0.100 0.100
Antioxidant 0.050 0.050 0.050 0.050 0.050 0.050
────────────────────────────────────

Color tone L ^* 76.28 73.34 74.79 74.65 57.36 57.85
a ^* -0.86 21.62 22.07 20.70 -4.05 -4.04
b ^* -2.65 49.91 49.93 47.18 -15.45 -15.68
Whiteness W 70.83 49.37 49.84 51.17 48.09 48.50
────────────────────────────────────
Light transmittance (%) 97.88 72.69 50.81 43.76 70.23 44.51
────────────────────────────────────
L ^* x Light transmittance 7455 5331 3800 3267 4028 2575
────────────────────────────────────
Appearance evaluation 1 1 2 3 1 3
────────────────────────────────────

  From the results described in Table 1, the granular chromatic color resin composition of the present invention has a high light shielding ability of solid foreign matters mixed inside the molded product molded from the resin composition, and therefore resin molding used for various applications. It turns out that it is suitable for the manufacture of things.

Claims (11)

A granular chromatic resin composition comprising an unused thermoplastic resin component, a chromatic pigment and a white pigment, wherein the relationship between the lightness (L ^* ) and light transmittance of a sheet prepared from the resin composition is A granular chromatic resin composition characterized by satisfying:

1300 ≦ (L ^* × B) ≦ 4000

[L ^* is the brightness of a sheet having a thickness of 3 mm prepared from the resin composition, and B is the total light transmittance (%) of a sheet having a thickness of 50 μm prepared from the resin composition].   The granular chromatic resin composition according to claim 1, wherein the resin composition further contains a black pigment.   The granular chromatic resin composition according to claim 1 or 2, wherein the resin composition contains a filler.   The granular chromatic resin composition according to any one of claims 1 to 3, wherein the thermoplastic resin component contains polyolefin as a main component.   The granular chromatic resin composition according to any one of claims 1 to 4, wherein a sheet prepared from the resin composition exhibits a whiteness of less than 55.   The granular chromatic resin composition according to any one of claims 1 to 5, wherein the total light transmittance represented by B of the sheet prepared from the resin composition is in the range of 15 to 60%.   The granular chromatic resin composition according to any one of claims 1 to 6, wherein the content of the white pigment in the granular resin composition is 1% by mass or more and 20% by mass or less.   The granular chromatic resin composition according to any one of claims 1 to 7, wherein the white pigment is titanium dioxide.   The granular chromatic resin composition according to any one of claims 2 to 8, wherein the content of the black pigment in the resin composition is 0.01% by mass or more and less than 1.0% by mass.   The granular chromatic resin composition according to any one of claims 2 to 9, wherein the black pigment is iron black. A chromatic resin molded article obtained by heating and melting the granular chromatic resin composition according to any one of claims 1 to 10, and then molding the resin composition.