Black resin composition and molded body

Abstract

One embodiment of the present invention relates to a black resin composition comprising a polyolefin resin (A) and a pigment (B), in which a molded body having a longitudinal direction of 150 mm, a transverse direction of 120 mm, and a thickness of 2 mm, which is molded from the black resin composition by an injection molding machine, has an average transmittance of 1% or less at a wavelength of 380 nm to 800 nm, and an average transmittance of 25% or more at a wavelength of 800 nm to 2500 nm, [Delta] MDS represented by formula (1) is 0.35% or less, and [Delta] TDS represented by formula (2) is 0.35% or less.

Description

Technical Field

[0001] The present invention relates to a black resin composition and a molded body formed from the black resin composition. Background Art

[0002] Plastics are easy to shape and process, so they are used in a wide range of fields such as electrical and electronic equipment parts, automobile parts, medical parts, and food containers. In order to improve the decorative effect, the coloring of plastic molded bodies is becoming popular. In particular, in the field of caps and bottles, multi-colorization is being promoted to differentiate products, and molded bodies with various colors or designs are circulating in the market.

[0003] Regarding these molded bodies, in recent years, from the perspective of effective utilization of resources and protection of the global environment, the demand for the reuse of discarded plastics has become increasingly strong. In order to reuse plastics and avoid degradation of the properties of recycled plastics, it is required to classify resin types such as polyolefins or polyesters to avoid mixing waste plastics of different materials into the recycled waste plastics. As a classification method for waste plastics, a classification method using infrared rays (IR) is known.

[0004] At this time, since the black molded body colored with carbon black does not transmit infrared rays, it is difficult to identify the type of resin using IR. Therefore, there is a demand for the development of a black resin composition that transmits IR and has mechanical identification without using carbon black.

[0005] As a method of producing a black resin composition using a plurality of organic pigments without using carbon black, the techniques disclosed in Patent Document 1 and Patent Document 2 are known.

[0006] Prior art literature

[0007] Patent Literature

[0008] Patent Document 1: Japanese Patent Application Publication No. 2014-214244

[0009] Patent Document 2: Japanese Patent Application Publication No. 2014-63091 Summary of the invention

[0010] Problems to be solved by the invention

[0011] However, in these existing methods, when the polyolefin resin used in the cap or bottle is colored, there are problems such as warping or shrinkage of the molded body. Therefore, if a variety of pigments are used, the change of size cannot be more strictly controlled, and the dimensional stability under high precision cannot be fully achieved. Thus, for example, if it is a lid for beverages, the lid shrinks over time, and the torque when opening the lid increases, which causes the problem that the elderly or women cannot open it. In addition, if the amount of pigment added is reduced in order to reduce the influence of the pigment, the tinting power decreases, so there is a problem that the required design cannot be obtained.

[0012] That is, the purpose of several embodiments of the present invention is to provide a black resin composition and a molded body formed by the black resin composition, wherein the black resin composition can form a molded body as follows: when the polyolefin resin is colored using a variety of pigments, it not only has excellent shielding properties in the visible light region, low brightness, and excellent design, but also shows high transmittance in the near-infrared region while suppressing the increase in dimensional stability and opening torque.

[0013] Technical means of solving problems

[0014] The present inventors have conducted intensive studies to solve the above-mentioned problems and have completed the present invention.

[0015] That is, one embodiment of the present invention relates to a black resin composition comprising a polyolefin resin (A) and a pigment (B), wherein a molded body having a length of 150 mm, a width of 120 mm and a thickness of 2 mm formed from the black resin composition by an injection molding machine has an average transmittance of less than 1% at a wavelength of 380 nm to 800 nm and an average transmittance of more than 25% at a wavelength of 800 nm to 2500 nm, a ΔMDS expressed by the following formula (1) satisfies less than 0.35%, and a ΔTDS expressed by the following formula (2) satisfies less than 0.35%.

[0016] Formula (1) ΔMDS=|X1-X0|

[0017] Formula (2) ΔTDS=|Y1-Y0|

[0018] (In addition, X1 and Y1 are respectively the shrinkage rate in the same direction as the injection direction (machine direction, MD direction) and the shrinkage rate in the direction perpendicular to the injection direction (transverse direction, TD direction) of a molded body with a length of 150 mm, a width of 120 mm, and a thickness of 2 mm formed by an injection molding machine and left to stand at 23° C. and 50% RH for 24 hours,

[0019] X0 and Y0 are respectively the shrinkage rate in the same direction as the injection direction (MD direction) and the shrinkage rate in the direction perpendicular to the injection direction (TD direction) after a molded body with a length of 150 mm, a width of 120 mm and a thickness of 2 mm formed by an injection molding machine is left to stand at 23°C and 50% RH for 24 hours.)

[0020] Another embodiment of the present invention relates to a molded body formed from the black resin composition.

[0021] Still another embodiment of the present invention relates to a cap as the molded body.

[0022] Effects of the Invention

[0023] According to several embodiments of the present invention, a black resin composition and a molded body formed by the black resin composition can be provided, wherein the black resin composition can form a molded body that exhibits high transmittance in the near-infrared region while imparting good design properties when a polyolefin resin is colored using a variety of pigments, thereby suppressing an increase in dimensional stability and opening torque. DETAILED DESCRIPTION

[0024] The embodiment of the present invention will be described in detail below. However, the following description is an example (representative example) of the embodiment of the present invention, and the present invention is not limited to these contents unless exceeding the gist of the invention.

[0025] In addition, in this specification, the numerical range specified using "to" includes the numerical values ​​described before and after "to" as the lower limit and the upper limit of the range.

[0026] In addition, unless otherwise specified, various components appearing in the present specification may be used alone or in combination of two or more.

[0027] In this specification, “CI” stands for Color Index, and “RH” stands for Relative Humidity.

[0028] 《Black resin composition》

[0029] The black resin composition of the present invention comprises a polyolefin resin (A) and a pigment (B). Regarding a molded body having a length of 150 mm, a width of 120 mm and a thickness of 2 mm formed by the black resin composition by an injection molding machine, the average transmittance at a wavelength of 380 nm to 800 nm is less than 1%, and the average transmittance at a wavelength of 800 nm to 2500 nm is more than 25%, the ΔMDS represented by the following formula (1) satisfies less than 0.35%, and the ΔTDS represented by the following formula (2) satisfies less than 0.35%.

[0030] Formula (1) ΔMDS = |X1-X0|

[0031] Formula (2) ΔTDS = |Y1-Y0|

[0032] X1 is the shrinkage rate in the same direction as the injection direction (MD direction) after a molded body with a length of 150 mm, a width of 120 mm and a thickness of 2 mm formed by an injection molding machine is left to stand at 23°C and 50% RH for 24 hours. Y1 is the shrinkage rate in the direction at right angles to the injection direction (TD direction).

[0033] X0 is the shrinkage rate in the same direction as the injection direction (MD direction) after a molded body with a length of 150 mm, a width of 120 mm and a thickness of 2 mm formed by an injection molding machine from a polyolefin resin (A) is left to stand at 23°C and 50% RH for 24 hours. Y0 is the shrinkage rate in the direction at right angles to the injection direction (TD direction).

[0034] In addition, when the polyolefin resin (A) is a mixture, only the molded body of the polyolefin resin (A) having the largest resin ratio in the polyolefin resin (A) can be used to calculate X0 and Y0. When the ratios of multiple resins contained are the same, the molded body of the polyolefin resin (A) having the smallest shrinkage rate can be used as a reference.

[0035] Regarding the shrinkage rate, a plate-shaped formed body with a length of 150 mm, a width of 120 mm and a thickness of 2 mm was used, and the distance between the markings was measured with a precision vernier caliper. Based on the value, the shrinkage rate [%] = measured length [mm] / distance between markings [mm] × 100 was calculated.

[0036] When ΔMDS and ΔTDS are 0.35% or less, it can be said that the dimensional change caused by coloring with the pigment is controlled and that the molded body maintains high-precision dimensional stability.

[0037] ΔMDS is more preferably 0.3% or less, further preferably 0.2% or less, and the closer to 0%, the more preferably. Also, ΔTDS is more preferably 0.3% or less, preferably 0.2% or less, and the closer to 0%, the more preferably.

[0038] When the content is within the above range, it can be said that the molded body has the shrinkage difference controlled at the same level as that of a molded body made of an uncolored resin.

[0039] The average transmittance at a wavelength of 380 nm to 800 nm in the visible light region is preferably 1% or less, more preferably 0.07% or less, and still more preferably 0.06% or less. The lower limit is preferably substantially 0%.

[0040] When the content is within the above range, a molded product having lower brightness and excellent design properties can be formed.

[0041] The average transmittance at a wavelength of 800 nm to 2500 nm in the near-infrared region is 25% or more, more preferably 27% or more, and even more preferably 28% or more. It is not particularly limited, but is preferably 80% or less.

[0042] When the content is within the above range, mechanical visibility is further improved, and the accuracy of classification of waste plastics can be improved.

[0043] The average transmittance is determined by measuring, using a spectrophotometer, a molded body having a length of 150 mm, a width of 120 mm, and a thickness of 2 mm, which is formed from the black resin composition by an injection molding machine.

[0044] As the spectrophotometer, for example, an ultraviolet-visible spectrophotometer UV-3150 manufactured by Shimadzu Corporation can be used.

[0045] The black resin composition is obtained by mixing the pigment (B) with the polyolefin resin (A) at a temperature where the polyolefin resin (A) is molten. In the method for manufacturing the black resin composition, for example, various additives may be further added to the polyolefin resin (A) and the pigment (B) as needed, and a batch mixer, a single-shaft extruder, a double-shaft extruder, a rotor-type double-shaft mixer, etc. such as a kneader, a roller mill, a super mixer, a high-speed mixer, a ball mill, a sand mill, a grinder, a Banbury mixer, etc. may be used to mix or melt-mix to form a granular, powdery, granular or beaded resin composition. Since the mixing force is strong, the subsequent forming process is easy, and therefore it is preferably formed into granules using a single-shaft extruder or a double-shaft extruder.

[0046] The black resin composition may be a composite obtained by mixing a pigment (B) in a desired amount in a polyolefin resin (A) and directly using it for molding, or may be a masterbatch containing a high concentration of the pigment (B) and may be diluted with a diluent resin and then used for molding.

[0047] <Polyolefin resin (A)>

[0048] The polyolefin resin (A) in the present invention is a polymer of olefin monomers such as ethylene, propylene, butene, etc., and may be a block or random copolymer showing a melting point in the range of 40°C to 200°C, or may be a binary copolymer or a ternary copolymer, etc. Specifically, there may be mentioned α-olefin polymers such as linear low-density polyethylene resin (linear low-density polyethylene (LLDPE)), low-density polyethylene resin (LDPE), high-density polyethylene resin (HDPE), and polypropylene resin (PP).

[0049] The polypropylene resin (PP) may be any one of homo-polypropylene (h-PP), block-polypropylene (b-PP), and random-polypropylene (r-PP).

[0050] The polyolefin resin (A) is preferably HDPE or PP having high crystallinity in that the effects of the present invention are easily obtained.

[0051] In addition, the melting point in this specification is a value measured using a differential scanning calorimeter "DSC6200" (manufactured by Seiko Instruments) under the conditions of a temperature range of 40°C to 200°C and a heating rate of 10°C / min.

[0052] When temporarily set as a masterbatch, the MFR (melt flow rate (MFR), also called melt viscosity) of the polyolefin resin (A) is preferably 5 g / 10 min to 100 g / 10 min, and more preferably 10 g / 10 min to 60 g / 10 min. If the MFR of the polyolefin resin (A) is 5 g / 10 min or more, the masterbatch is fully distributed when the masterbatch is added to the diluted resin, which can further suppress the appearance of poor color unevenness and other appearance of the molded body. On the other hand, if the MFR is less than 100 g / 10 min, it is possible to prevent the overall melt viscosity of the system from decreasing during molding and affecting the moldability. The polyolefin resin (A) used in the masterbatch and the diluted resin are preferably the same type of polyolefin resin. For example, when the polyolefin resin (A) used as the diluted resin is HDPE, the polyolefin resin (A) in the masterbatch is also preferably HDPE.

[0053] When the black resin composition is a composite, the MFR of the polyolefin resin (A) is preferably 5 g / 10 minutes or less, and more preferably 0.1 g / 10 minutes to 5 g / 10 minutes. By having the MFR of the polyolefin resin (A) be within the range, formability and dimensional stability can coexist. In some embodiments, when the black resin composition is a composite, when the polyolefin resin (A) is a high-density polyethylene resin (HDPE) or a polypropylene resin (PP), the MFR of the polyolefin resin (A) is preferably 5 g / 10 minutes or less, and more preferably 0.1 g / 10 minutes to 5 g / 10 minutes.

[0054] In addition, MFR in the present invention is a value measured in accordance with Japanese Industrial Standards (JIS) K-7210.

[0055] Specific examples of the polyolefin resin (A) include Novatec LL UJ580 (LLDPE, MFR: 20 g / 10 min, manufactured by Japan Polyethylene Co., Ltd.), Suntec LD M2270 (LDPE, MFR: 7 g / 10 min, manufactured by Asahi Kasei Corporation), Suntec HD J240 (HDPE, MFR: 5 g / 10 min, manufactured by Asahi Kasei Corporation), Suntec HD J300 (HDPE, MFR: 42 g / 10 min, manufactured by Asahi Kasei Corporation), PrimePolypro J229E (PP, MFR: 50 g / 10 min, manufactured by Prime Polymer Co., Ltd.), etc. Furthermore, Nipolon Hard 6530 (HDPE, MFR: 0.1 g / 10 min, manufactured by Tosoh Corporation) can be mentioned.

[0056] The content of the polyolefin resin (A) in 100% by mass of the resin composition is preferably 60% by mass or more and less than 100% by mass, and more preferably 90% by mass or more. If the amount of the polyolefin resin (A) is 60% by mass or more, it is easy to sufficiently maintain the strength of the molded body.

[0057] <Pigment (B)>

[0058] As the pigment (B), at least one selected from the group consisting of an inorganic pigment (B1) and an organic pigment (B2) can be used. Preferred embodiments of the pigment (B) include the following embodiments I and II.

[0059] <Embodiment I of the pigment (B)>

[0060] In some embodiments, as the pigment (B), an organic pigment (B2) or an inorganic pigment (B1) can be used without particular limitation, and a black pigment composition can be prepared by combining a plurality of blue pigments, red pigments, yellow pigments, green pigments, violet pigments, etc.

[0061] Among them, from the viewpoint of low brightness and design of the black molded body, it is preferred to contain a blue pigment, and at least one of a red pigment and a violet pigment, and it is more preferred to further contain a yellow pigment. Of the red pigment and the violet pigment, it is more preferred to contain a red pigment.

[0062] In addition, the red pigment and the violet pigment preferably include at least one selected from the group consisting of CI Pigment Red 122, CI Pigment Red 254, and CI Pigment Violet 19 from the viewpoint of dimensional stability.

[0063] [Inorganic pigment (B1)]

[0064] Examples of the inorganic pigment (B1) include titanium oxide, zinc flower, zinc sulfide, white lead, calcium carbonate, precipitated barium sulfate, white carbon, white aluminum oxide, kaolin, talc, bentonite, black iron oxide, carbon black, cadmium red, Bengala, molybdenum red, molybdate orange, chrome vermilion, chrome yellow, cadmium yellow, yellow iron oxide, titanium yellow, chromium oxide, chrome green, titanium cobalt green, cobalt green, cobalt chrome green, Victoria green, ultramarine, dark blue, cobalt blue, sky blue, cobalt silicon blue, cobalt zinc silicon blue, manganese violet, and cobalt violet.

[0065] [Organic pigment (B2)]

[0066] Examples of the organic pigment (B2) include diketopyrrolopyrrole pigments, azo pigments (e.g., azo, disazo, polyazo, etc.), phthalocyanine pigments (e.g., copper phthalocyanine, halogenated copper phthalocyanine, metal-free phthalocyanine, etc.), anthraquinone pigments (e.g., aminoanthraquinone, diaminodianthraquinone, anthrapyrimidine, flavanthrone, dibenzopyrene-5,10-dione, indanthrone, pyranthrone, isoanthrone violet, etc.), quinacridone pigments, dioxazine pigments, perinone pigments, perylene pigments, thioindigo pigments, isoindoline pigments, isoindolinone pigments, quinophthalone pigments, threne pigments, or metal complex pigments.

[0067] Among these, from the viewpoint of dimensional stability, diketopyrrolopyrrole pigments, azo pigments, phthalocyanine pigments, and quinacridone pigments are preferred, and diketopyrrolopyrrole pigments, monoazo pigments, disazo pigments, copper phthalocyanine pigments, halogenated copper phthalocyanine pigments, and quinacridone pigments are more preferred.

[0068] The pigment (B) preferably does not contain carbon black from the viewpoint of transmittance in the near-infrared region, and the content of carbon black in 100% by mass of the pigment (B) is preferably 0.05% by mass or less.

[0069] In terms of visible light shielding and near-infrared transmittance, the preferred combination of pigment (B) preferably includes a phthalocyanine blue pigment or a cobalt blue pigment, and at least one of a quinacridone red pigment, a diketopyrrolopyrrole red pigment, and a quinacridone violet pigment, and more preferably also includes a monoazo yellow pigment or a disazo yellow pigment.

[0070] In terms of shrinkage, a more preferred combination of pigments (B) is preferably the following combination: a monoazo yellow pigment, a quinacridone red pigment, and a phthalocyanine blue pigment; a monoazo yellow pigment, a diketopyrrolopyrrole red pigment, and a phthalocyanine blue pigment; a monoazo yellow pigment, a quinacridone violet pigment, and a phthalocyanine blue pigment; a disazo yellow pigment, a quinacridone red pigment, and a phthalocyanine blue pigment; a disazo yellow pigment, a diketopyrrolopyrrole red pigment, and a phthalocyanine blue pigment. Pigments; disazo yellow pigments, quinacridone violet pigments and phthalocyanine blue pigments; monoazo yellow pigments, quinacridone red pigments and cobalt blue; monoazo yellow pigments, diketopyrrolopyrrole red pigments, cobalt blue, monoazo yellow pigments, quinacridone violet pigments and cobalt blue; disazo yellow pigments, quinacridone red pigments and cobalt blue; disazo yellow pigments, diketopyrrolopyrrole red pigments and cobalt blue; disazo yellow pigments, quinacridone violet pigments and cobalt blue.

[0071] Furthermore, from the viewpoint of transmittance, as the pigment (B), the following combination is more preferred: monoazo yellow pigment, quinacridone red pigment and phthalocyanine blue pigment; monoazo yellow pigment, diketopyrrolopyrrole red pigment and phthalocyanine blue pigment; monoazo yellow pigment, quinacridone violet pigment and phthalocyanine blue pigment; disazo yellow pigment, quinacridone red pigment and phthalocyanine blue pigment; disazo yellow pigment, diketopyrrolopyrrole red pigment and phthalocyanine blue pigment; disazo yellow pigment, quinacridone violet pigment and phthalocyanine blue pigment.

[0072] Specific examples of the blue pigment, the red pigment, the yellow pigment, the green pigment, and the violet pigment, and further specific examples of the orange pigment will be described later.

[0073] About the content of each pigment, as long as the molded body of 150mm in length, 120mm in width and 2mm in thickness formed by the black resin composition by the injection molding machine satisfies the average transmittance of 380nm-800nm ​​of wavelength 1% or less and the average transmittance of 800nm-2500nm of wavelength 25% or more, there is no particular restriction, but in the case of at least one of the blue pigment, red pigment and violet pigment, with the total amount of pigment (B) 100% by mass as a benchmark, from the viewpoint of design, the blue pigment is preferably 10% to 60% by mass, more preferably 20% to 50% by mass. The red pigment or violet pigment is preferably 20% to 50% by mass, more preferably 30% to 40% by mass. In addition, in the case of both red pigment and violet pigment, the total amount of red pigment and violet pigment is preferably within the range. Other pigments other than blue pigment, red pigment and violet pigment are preferably 10% to 30% by mass, more preferably 15% to 25% by mass. In this case, other pigments are pigments other than blue pigments, red pigments, and violet pigments, and examples thereof include yellow pigments, green pigments, and orange pigments.

[0074] In addition, when a blue pigment and at least one of a red pigment and a violet pigment are included, from the viewpoint of the light-shielding property of the molded body in the visible light region, the content of the blue pigment is preferably 100 to 300 parts by mass, and more preferably 150 to 250 parts by mass, relative to 100 parts by mass of the red pigment and the violet pigment.

[0075] In addition, regarding the amount of each color pigment, in terms of the coexistence of dimensional stability and design, the blue pigment is preferably mixed in 100% by mass of the molded body at 0.05% by mass to 0.8% by mass, and more preferably 0.1% by mass to 0.5% by mass. The red pigment is preferably mixed in 0.05% by mass to 0.5% by mass, and more preferably 0.1% by mass to 0.4% by mass. The yellow pigment is preferably mixed in 0% by mass to 0.5% by mass, and more preferably 0.05% by mass to 0.4% by mass.

[0076] Regarding the content of pigment (B), from the viewpoint of the coexistence of dimensional stability and design, in 100% by mass of the molded body, it is preferably 0.01% by mass or more, more preferably 0.1% by mass or more, and further preferably 0.3% by mass or more. In addition, it is preferably 1% by mass or less, and more preferably less than 0.8% by mass.

[0077] <Embodiment II of the pigment (B)>

[0078] In some embodiments, the pigment (B) comprises an inorganic pigment (B1x), and the inorganic pigment (B1x) is at least any one selected from the group consisting of CI Pigment Brown 29, CI Pigment Black 11, CI Pigment Black 27, CI Pigment Black 33, CI Pigment Black 36, and CI Pigment Green 17.

[0079] This can suppress the occurrence of warping, shrinkage, etc. in the molded body when the polyolefin resin is colored, thereby achieving dimensional stability with high precision.

[0080] From the viewpoint of design, when the pigment (B) includes an inorganic pigment (B1x), the pigment (B) preferably further includes other pigments. In this case, the other pigment is at least one of an organic pigment (B2) and other inorganic pigments (B1y) other than the inorganic pigment (B1x), and more preferably includes an organic pigment (B2).

[0081] [Inorganic pigment (B1x)]

[0082] The inorganic pigment (B1x) is at least one selected from the group consisting of CI Pigment Brown 29, CI Pigment Black 11, CI Pigment Black 27, CI Pigment Black 33, CI Pigment Black 36 and CI Pigment Green 17. One of these may be used alone or two or more of these may be used in combination.

[0083] From the viewpoint of design properties, CI Pigment Brown 29 or CI Pigment Black 33 is preferred.

[0084] Examples of commercially available products include PS24-3950 (manufactured by Fellow) in CI Pigment Brown 29, Bayferrox 306 (manufactured by LANXESS) in CI Pigment Black 11, Daipyroxide Black #9590 (manufactured by Dainichi Seika Industries) in CI Pigment Black 27, Bayferrox 303T (manufactured by LANXESS) in CI Pigment Black 33, Tipaque Black SG-101 (manufactured by Ishihara Sangyo Co., Ltd.) in CI Pigment Black 36, and Shepherd Black 10P922 (manufactured by Shepherd) in CI Pigment Green 17.

[0085] The inorganic pigment (B1x) is preferably blended in an amount of 1.0 to 3.0 mass %, more preferably 1.2 to 2.0 mass %, based on 100 mass % of the molded article. When the inorganic pigment (B1x) is within the above range, higher design properties can be obtained.

[0086] The content of the inorganic pigment (B1x) is preferably 50% by mass or more, more preferably 80% by mass or more, further preferably 90% by mass or more, and particularly preferably 95% by mass or more in 100% by mass of the pigment (B). In addition, it is preferably less than 100% by mass, more preferably 99.99% by mass or less. When the inorganic pigment (B1x) is within the above range, higher design properties can be obtained.

[0087] [Inorganic pigment (B1y)]

[0088] The inorganic pigment (B1y) is an inorganic pigment other than the inorganic pigment (B1x), and examples thereof include titanium oxide, zinc flower, zinc sulfide, white lead, calcium carbonate, precipitated barium sulfate, white carbon, aluminum oxide white, kaolin, talc, bentonite, cadmium red, red iron, molybdenum red, molybdenum orange, chrome vermilion, chrome yellow, cadmium yellow, yellow iron oxide, titanium yellow, chromium oxide, chrome green, titanium cobalt green, cobalt green, cobalt chrome green, Victoria green, ultramarine, dark blue, cobalt blue, sky blue, cobalt silicon blue, cobalt zinc silicon blue, manganese violet, or cobalt violet.

[0089] Among these, green inorganic pigments or blue inorganic pigments are preferred from the viewpoint of design properties, and chrome green, titanium cobalt green, cobalt green, cobalt chrome green, Victoria green ultramarine, dark blue, cobalt blue, sky blue, cobalt silicon blue, or cobalt zinc silicon blue is preferred.

[0090] The pigment (B) preferably does not contain carbon black from the viewpoint of infrared transmittance, and the content of carbon black in 100% by mass of the pigment (B) is preferably 0.05% by mass or less.

[0091] [Organic pigment (B2)]

[0092] As the organic pigment (B2), the examples of the organic pigment (B2) listed in Embodiment 1 can be applied. Preferred examples are also the same as those listed in Embodiment 1.

[0093] There are no particular restrictions on the organic pigment (B2) and inorganic pigment (B1y) as other pigments, and blue pigments, red pigments, violet pigments, yellow pigments, green pigments, orange pigments, etc. can be used. By combining the inorganic pigment (B1x) with these other pigments, a black resin composition can be prepared.

[0094] From the viewpoint of design, blue pigment, red pigment, purple pigment, yellow pigment or green pigment are preferred. Among them, from the viewpoint of low brightness and excellent design of black molded body, other pigments preferably include at least one of blue pigment and green pigment, and more preferably include blue pigment.

[0095] The blue pigment and the green pigment are preferably phthalocyanine blue organic pigments or phthalocyanine green organic pigments, and more preferably CI Pigment Blue 15, CI Pigment Blue 15:1, CI Pigment Blue 15:3 or CI Pigment Green 7.

[0096] In addition, from the viewpoint of dimensional stability, it is preferred that the other pigments include at least one of a red pigment and a violet pigment.

[0097] The red pigment and the violet pigment are preferably diketopyrrolopyrrole red pigments, azo red pigments, quinacridone red pigments, azo yellow pigments or quinacridone violet pigments, and more preferably CI Pigment Red 122, CI Pigment Red 254 or CI Pigment Violet 19.

[0098] Specific examples of the blue pigment, the red pigment, the violet pigment, the yellow pigment, the green pigment, and the orange pigment will be described later.

[0099] From the viewpoint of both dimensional stability and designability, the total content of the organic pigment (B2) and the inorganic pigment (B1y) is preferably 0.001% by mass or more, more preferably 0.1% by mass or more, and further preferably 0.3% by mass or more in 100% by mass of the molded article. It is also preferably 1% by mass or less, and more preferably less than 0.8% by mass.

[0100] From the viewpoint of the coexistence of dimensional stability and designability, the total content of the organic pigment (B2) or the inorganic pigment (B1y) is preferably 50% by mass or less, more preferably 20% by mass or less, further preferably 10% by mass or less, particularly preferably 5% by mass or less, in 100% by mass of the pigment (B). In addition, it is preferably 0.01% by mass or more.

[0101] Regarding the content of each pigment, as long as the molded body with a length of 150 mm, a width of 120 mm, and a thickness of 2 mm formed by the black resin composition by an injection molding machine satisfies the average transmittance of the wavelength of 380 nm-800 nm to be less than 1% and the average transmittance of the wavelength of 800 nm-2500 nm to be more than 25%, there is no particular restriction, but in the case of at least one of the blue pigment and the green pigment, based on the total amount of the pigment (B) 100% by mass, from the viewpoint of design, the blue pigment is preferably 0.1% by mass to 1.2% by mass, more preferably 0.5% by mass to 1.0% by mass. The green pigment is preferably 0.1% by mass to 1.0% by mass, more preferably 0.3% by mass to 0.8% by mass. The other color pigments other than the blue pigment and the green pigment are preferably 0.5% by mass or less, more preferably 0.3% by mass or less.

[0102] In addition, when at least one of a blue pigment and a green pigment is included as another pigment, the blue pigment is preferably 0.1 to 1.2 parts by mass, more preferably 0.5 to 1.0 parts by mass, relative to 100 parts by mass of the content of the inorganic pigment (B1x), from the viewpoint of warping. The green pigment is preferably 0.1 to 1.0 parts by mass, more preferably 0.3 to 0.8 parts by mass.

[0103] <Examples of pigments>

[0104] Specific examples of the blue pigment, the red pigment, the violet pigment, the yellow pigment, the green pigment, and the orange pigment are listed below.

[0105] [Blue pigment]

[0106] Examples of blue pigments include:

[0107] CI Pigment Blue 15, CI Pigment Blue 15:1, CI Pigment Blue 15:3 and other phthalocyanine blue organic pigments,

[0108] CI Pigment Blue 28 and other cobalt-based blue inorganic pigments,

[0109] Ultramarine blue inorganic pigments such as CI Pigment Blue 29, etc.

[0110] Among them, from the viewpoint of dimensional stability, phthalocyanine blue organic pigments or cobalt blue inorganic pigments are preferred. Furthermore, from the viewpoint of near-infrared transmittance, phthalocyanine blue organic pigments are more preferred. Among them, CI Pigment Blue 15:3 is more preferred.

[0111] Examples of commercially available products include Fastogen Blue AR-7 (manufactured by DIC Corporation) in CI Pigment Blue 15, Lionol Blue POBS (manufactured by Toyocolor Corporation) in Pigment Blue 15:1, Lionol Blue FG-7350 (manufactured by Toyocolor Corporation) in Pigment Blue 15:3, Sicopal Blue K6210 (manufactured by BASF Corporation) in CI Pigment Blue 28, and Ultramarine 1500 (manufactured by Resinocolor Corporation) in CI Pigment Blue 29.

[0112] [Red pigment]

[0113] Examples of red pigments include:

[0114] CI Pigment Red 122, CI Pigment Red 207, CI Pigment Red 209 and other quinacridone red organic pigments,

[0115] CI Pigment Red 254, CI Pigment Red 264 and other diketopyrrolopyrrole red organic pigments,

[0116] CI Pigment Red 149, CI Pigment Red 178 and other perylene red organic pigments,

[0117] CI Pigment Red 48:2, CI Pigment Red 144, CI Pigment Red 151, CI Pigment Red 166, CI Pigment Red 208, CI Pigment Red 221 and other azo red organic pigments,

[0118] CI Pigment Red 177 and other anthraquinone red organic pigments,

[0119] Pyrazolone-based red organic pigments such as CI Pigment Red 38, etc.

[0120] Among them, from the viewpoint of dimensional stability, quinacridone red organic pigments or diketopyrrolopyrrole red organic pigments are preferred. Among them, CI Pigment Red 122 or CI Pigment Red 254 is more preferred.

[0121] Examples of commercially available products include TCR12203 Red (manufactured by TrustChem) in CI Pigment Red 122, Cinquasia Scarlet L3080 (manufactured by DIC) in CI Pigment Red 207, Hostaperm Red EG Transparent (manufactured by Clariant) in CI Pigment Red 209, Cinquasia Scarlet L3080 (manufactured by DIC) in CI Pigment Red 149, Paliogen Red K3911 (manufactured by BASF) in CI Pigment Red 178, Lionol Red DWG (manufactured by Toyocolor) in CI Pigment Red 48:2, and Cromophtal Red (manufactured by Clariant) in CI Pigment Red 144. CI Pigment Red 151 Red 202 (manufactured by Arimoto Chemical Industry Co., Ltd.), CI Pigment Red 166 Cromoftal Scarlet D3540 (manufactured by BASF), CI Pigment Red 208 Symuler Fast Red 4598 (manufactured by DIC), CI Pigment Red 221 Cromoftal Red K3830 (manufactured by BASF), CI Pigment Red 177 Fastogen Super Red ATY (manufactured by Clariant), CI Pigment Red 38 Graphtol Red HFG (manufactured by Clariant), CI Pigment Red 254 Cromoftal Red 354 ...208 Symuler Fast Red 4598 (manufactured by DIC), CI Pigment Red 221 Cromoftal Red K3830 (manufactured by BASF), CI Pigment Red 208 Symuler Fast Red 4598 (manufactured by DIC), CI Pigment Red 208 Symuler Fast Red 4598 (manufactured by DIC), CI Pigment Red 221 Examples of the present invention include CI Pigment Red 2028 (manufactured by BASF), Irgazin DPP Rubine TR in CI Pigment Red 264 (manufactured by BASF), and the like.

[0122] [Purple pigment]

[0123] Examples of violet pigments include:

[0124] CI Pigment Violet 15 and other cyan-based purple inorganic pigments,

[0125] CI Pigment Violet 19 and other quinacridone purple organic pigments,

[0126] Dioxazine-based violet organic pigments such as CI Pigment Violet 23, etc.

[0127] Among them, quinacridone-based violet organic pigments are preferred from the viewpoint of dimensional stability. Among them, CI Pigment Violet 19 is more preferred.

[0128] Examples of commercially available products include Ultramarine Violet 12 (manufactured by Fellow) in CI Pigment Violet 15, Chromofine Violet 6845 (manufactured by Dainichi Seika Co., Ltd.) in CI Pigment Violet 19, and PV Fast Violet RL (manufactured by Clariant) in CI Pigment Violet 23.

[0129] [Yellow pigment]

[0130] Examples of yellow pigments include:

[0131] CI Pigment Yellow 150, CI Pigment Yellow 151, CI Pigment Yellow 168, CI Pigment Yellow 169, CI Pigment Yellow 181, CI Pigment Yellow 183 and other monoazo yellow organic pigments,

[0132] CI Pigment Yellow 83, CI Pigment Yellow 180, CI Pigment Yellow 214 and other disazo yellow organic pigments,

[0133] CI Pigment Yellow 53 and other nickel-titanium yellow inorganic pigments,

[0134] CI Pigment Yellow 93, CI Pigment Yellow 95 and other condensed azo yellow organic pigments,

[0135] CI Pigment Yellow 138 and other quinophthalone yellow organic pigments,

[0136] CI Pigment Yellow 109, CI Pigment Yellow 110, CI Pigment Yellow 139 and other isoindolinone yellow organic pigments,

[0137] CI Pigment Yellow 184 and other bismuth-based yellow organic pigments.

[0138] Among them, monoazo yellow organic pigments or disazo yellow organic pigments are preferred from the viewpoint of dimensional stability. Among them, CI Pigment Yellow 180 or CI Pigment Yellow 181 is more preferred.

[0139] Examples of commercially available products include Cromoth Yellow D1085J (manufactured by BASF) in CI Pigment Yellow 150, Cromoth Yellow L 1061HD (manufactured by BASF) in CI Pigment Yellow 151, Paliotol Yellow K1070 (manufactured by BASF) in CI Pigment Yellow 168, Lionol Yellow K2R (manufactured by Toyocolor) in CI Pigment Yellow 169, TCY18001E Yellow (Yellow) (manufactured by Trust Chem) in CI Pigment Yellow 181, Paliotol Yellow 1700 (manufactured by BASF) in CI Pigment Yellow 183, and Chromofine Yellow 83 (manufactured by BASF). Yellow) (manufactured by Dainichi Seika Co., Ltd.), Cromophtal Yellow K1410 in CI Pigment Yellow 180 (manufactured by BASF), PVFast Yellow H9G VP2430 in CI Pigment Yellow 214 (manufactured by Clariant), Sicotan Yellow K1010 in CI Pigment Yellow 53 (manufactured by BASF), Chromofine Yellow 5930 in CI Pigment Yellow 93 (manufactured by Dainichi Seika Co., Ltd.), Chromofine Yellow 5900 in CI Pigment Yellow 95 (manufactured by Dainichi Seika Co., Ltd.), Paliotol Yellow K0961 in CI Pigment Yellow 138 (manufactured by BASF), Irgazin Yellow in CI Pigment Yellow 109 CI Pigment Yellow 184 (manufactured by Fellow), CI Pigment Yellow 184 (manufactured by Lysopac Yellow 6601B (manufactured by Fellow), etc.

[0140] [Green pigment]

[0141] Examples of green pigments include:

[0142] CI Pigment Green 7, CI Pigment Green 36 and other phthalocyanine green organic pigments,

[0143] CI Pigment Green 50 and other cobalt-based green inorganic pigments.

[0144] Among them, phthalocyanine green organic pigments are preferred from the viewpoint of dimensional stability. Among them, CI Pigment Green 7 is more preferred.

[0145] Examples of commercially available products include Fastogen Green BN (manufactured by DIC Corporation) in CI Pigment Green 7, Fastogen Green 2YK (manufactured by DIC Corporation) in Pigment Green 36, and Sicopal Green L9715 (manufactured by BASF Corporation) in Pigment Green 50.

[0146] [Orange pigment]

[0147] Examples of orange pigments include

[0148] CI Pigment Orange 64 and other monoazo orange organic pigments.

[0149] <Optional ingredients>

[0150] The black resin composition of the present invention may contain additives such as metal soap of alkali metal, alkaline earth metal or zinc, hydrotalcite, nonionic surfactant, cationic surfactant, anionic surfactant, amphoteric surfactant, antistatic agent, halogen-based, phosphorus-based or metal oxide flame retardants, antioxidants, ultraviolet absorbers, fillers, etc., within the range not hindering the effect of the present invention.

[0151] "Formed Body"

[0152] The molded body is formed using the black resin composition of the present invention.

[0153] The molding method is not particularly limited, and the molded body can be obtained by extrusion molding, compression molding, injection molding, blow molding, or the like.

[0154] Regarding the molded body, a black resin composition can be obtained by kneading the polyolefin resin (A) with the pigment (B) at a temperature at which the polyolefin resin (A) is molten, and the molded body can be directly formed from the obtained black resin composition, or a masterbatch containing a high concentration of the pigment (B) can be prepared, and then the black resin composition can be obtained by kneading it at a prescribed ratio with a polyolefin resin as a diluent resin during the molding of the molded body, and the molded body can be molded from the obtained black resin composition.

[0155] The diluent resin in this case may be the same resin as the polyolefin resin (A) constituting the masterbatch or may be a different resin, but is preferably the same resin.

[0156] In 100% by mass of the masterbatch, the content of the polyolefin resin (A) is preferably 20% by mass or more, and more preferably 30% to 60% by mass. If the amount of the polyolefin resin (A) is 20% by mass or more, the processability during the production of the masterbatch becomes better. The content of the polyolefin resin (A) is more preferably 40% by mass or more. In addition, it is preferably 80% by mass or less. If the amount of the polyolefin resin (A) is within the range, the processability during the production of the masterbatch becomes better.

[0157] The content of the pigment (B) in 100% by mass of the masterbatch is preferably 1% by mass to 60% by mass, more preferably 5% by mass to 50% by mass, in 100% by mass of the black resin composition.

[0158] The content of the polyolefin resin (A) in 100% by mass of the molded article is preferably 60% by mass or more and less than 100% by mass, and more preferably 90% by mass or more. If the amount of the polyolefin resin (A) is 60% by mass or more, it is easy to sufficiently maintain the strength of the molded article.

[0159] The molded body formed from the black resin composition of the present invention has excellent suppression of warping or shrinkage and good dimensional stability, and can therefore be suitably used for automobile parts, nozzles, caps, trays, mechanical parts, etc. formed by compression molding (compression molding) or injection molding (injection molding) and bottles, cans, tanks, etc. formed by blow molding (direct blow molding, injection blow molding).

[0160] As such, since the molded body is excellent in design and dimensional stability, it can be used in various applications such as automobile parts, nozzles, caps, trays, machine parts, bottles, cans, tanks, etc. Among them, it is preferably used as a cap, and further, since it can suppress the shrinkage of the cap over time and the increase in torque when opening the cap, it can be suitably used even as a beverage cap that requires dimensional stability with higher precision.

[0161] 《Examples of implementation》

[0162] The present invention includes, for example, the following embodiments. The present invention is not limited to the following embodiments.

[0163] [1] A black resin composition comprising a polyolefin resin (A) and a pigment (B), wherein the black resin composition is characterized in that:

[0164] A molded body having a length of 150 mm, a width of 120 mm and a thickness of 2 mm, which is molded from the black resin composition by an injection molding machine, has an average transmittance of 1% or less at a wavelength of 380 nm to 800 nm, and an average transmittance of 25% or more at a wavelength of 800 nm to 2500 nm,

[0165] The ΔMDS represented by the following formula (1) satisfies 0.35% or less, and the ΔTDS represented by the following formula (2) satisfies 0.35% or less;

[0166] Formula (1) ΔMDS = |X1-X0|

[0167] Formula (2) ΔTDS = |Y1-Y0|

[0168] (In addition, X1 and Y1 are respectively the shrinkage rate in the same direction as the injection direction (MD direction) and the shrinkage rate in the direction perpendicular to the injection direction (TD direction) after a molded body with a length of 150 mm, a width of 120 mm and a thickness of 2 mm, which is molded from the black resin composition by an injection molding machine, is left to stand at 23° C. and 50% RH for 24 hours,

[0169] X0 and Y0 are respectively the shrinkage rate in the same direction as the injection direction (MD direction) and the shrinkage rate in the direction perpendicular to the injection direction (TD direction) of a molded body with a length of 150 mm, a width of 120 mm and a thickness of 2 mm formed by an injection molding machine and left to stand at 23°C and 50% RH for 24 hours.

[0170] [2] The black resin composition according to [1], wherein the pigment (B) comprises a blue pigment and at least one of a red pigment and a violet pigment.

[0171] The red pigment and the violet pigment include at least one selected from the group consisting of CI Pigment Red 122, CI Pigment Red 254, and CI Pigment Violet 19.

[0172] [3] The black resin composition according to [2], further comprising 100 to 300 parts by mass of a blue pigment based on 100 parts by mass of the red pigment and the violet pigment.

[0173] [4] The black resin composition according to [2] or [3], wherein the content of the red pigment and the violet pigment is 20% by mass to 40% by mass based on the total amount of the pigment (B).

[0174] [5] A molded article formed from the black resin composition according to any one of [1] to [4].

[0175] [6] A cap, which is the molded article according to [5].

[0176] According to the embodiment, a black resin composition and a molded body formed by the black resin composition can be provided, wherein the black resin composition can form a molded body that exhibits high transmittance in the near-infrared region while imparting good design properties when a polyolefin resin is colored using a variety of pigments, thereby suppressing an increase in dimensional stability and lid opening torque.

[0177] Furthermore, the present invention includes, for example, the following embodiments. The present invention is not limited to the following embodiments.

[0178] [1] A black resin composition comprising a polyolefin resin (A) and a pigment (B), wherein the black resin composition is characterized in that:

[0179] The pigment (B) includes an inorganic pigment (B1x), wherein the inorganic pigment (B1x) is at least one selected from the group consisting of CI Pigment Brown 29, CI Pigment Black 11, CI Pigment Black 27, CI Pigment Black 33, CI Pigment Black 36, and CI Pigment Green 17.

[0180] A molded body having a length of 150 mm, a width of 120 mm and a thickness of 2 mm, which is molded from the black resin composition by an injection molding machine, has an average transmittance of 1% or less at a wavelength of 380 nm to 800 nm, and an average transmittance of 25% or more at a wavelength of 800 nm to 2500 nm,

[0181] The ΔMDS represented by the following formula (1) satisfies 0.35% or less, and the ΔTDS represented by the following formula (2) satisfies 0.35% or less;

[0182] Formula (1) ΔMDS=|X1-X0|

[0183] Formula (2) ΔTDS=|Y1-Y0|

[0184] (In addition, X1 and Y1 are respectively the shrinkage rate in the same direction as the injection direction (MD direction) and the shrinkage rate in the direction perpendicular to the injection direction (TD direction) after a molded body with a length of 150 mm, a width of 120 mm and a thickness of 2 mm, which is molded from the black resin composition by an injection molding machine, is left to stand at 23° C. and 50% RH for 24 hours,

[0185] X0 and Y0 are respectively the shrinkage rate in the same direction as the injection direction (MD direction) and the shrinkage rate in the direction perpendicular to the injection direction (TD direction) of a molded body with a length of 150 mm, a width of 120 mm and a thickness of 2 mm formed by an injection molding machine and left to stand at 23°C and 50% RH for 24 hours.

[0186] [2] The black resin composition according to [1], wherein the pigment (B) further comprises another pigment,

[0187] The other pigment is at least any one of the organic pigment (B2) and the other inorganic pigment (B1y) other than the inorganic pigment (B1x).

[0188] [3] The black resin composition according to [2], wherein the other pigment includes at least one selected from the group consisting of a blue pigment, a red pigment, a violet pigment, a yellow pigment, and a green pigment.

[0189] [4] The black resin composition according to [2] or [3], wherein the organic pigment (B2) comprises at least one selected from the group consisting of phthalocyanine blue pigment, phthalocyanine green pigment, diketopyrrolopyrrole red pigment, azo red pigment, quinacridone red pigment, azo yellow pigment and quinacridone violet pigment.

[0190] [5] A molded article formed from the black resin composition according to any one of [1] to [4].

[0191] [6] A cap, which is the molded article according to [5].

[0192] According to the embodiment, a black resin composition and a molded body formed by the black resin composition can be provided, wherein the black resin composition can form a molded body that exhibits high transmittance in the infrared region while imparting good design properties when the polyolefin resin is colored with a pigment, thereby exhibiting excellent dimensional stability and suppressing an increase in the opening torque.

[0193] The disclosure of this application is related to the subject matter described in Japanese Patent Application No. 2022-094866 filed on June 13, 2022 and Japanese Patent Application No. 2022-194064 filed on December 5, 2022, and all disclosed contents are incorporated herein by reference.

[0194] Example

[0195] Hereinafter, the present invention will be described in more detail based on Examples, but the present invention is not limited to the Examples. In the Examples, "parts" and "%" respectively represent "parts by mass" and "mass %" unless otherwise specified.

[0196] In addition, the blending amounts in the table are parts by mass, and a blank column indicates that no blending is performed.

[0197] In addition, the method for measuring the melt viscosity of the polyolefin resin (A) is as follows.

[0198] [Melt viscosity of polyolefin resin (A)]

[0199] MFR is measured in accordance with JIS (Japanese Industrial Standards) K-7210.

[0200] Materials used in Examples and Comparative Examples are listed below.

[0201] <Polyolefin resin (A)>

[0202] A-1: Hi-Zex 2200J (manufactured by Prime Polymer, MFR: 5 g / 10 min, HDPE)

[0203] A-2: NUC-8008 (manufactured by NUC, MFR: 5g / 10min, LDPE)

[0204] A-3: Excellen FX352 (manufactured by Sumitomo Chemical Co., Ltd., MFR: 4 g / 10 minutes, LLDPE)

[0205] A-4: J105G (manufactured by Prime Polypro, MFR: 9 g / 10 min, h-PP)

[0206] A-5: J-705UG (manufactured by Prime Polypro, MFR: 9 g / 10 min, b-PP)

[0207] A-6: E-333GV (manufactured by Prime Polypro, MFR: 2g / 10min, r-PP)

[0208] In the present specification, “h-PP” means homo-PP, “b-PP” means block PP, and “r-PP” means random PP.

[0209] <Organic pigment (B) used in the examples and comparative examples of <<Example I>>

[0210] [Blue pigment]

[0211] B-1: Sicopal Blue K6210 (manufactured by BASF, CI Pigment Blue 28, cobalt blue)

[0212] B-2: Lionol Blue FG-7350 (manufactured by Toyocolor, CI Pigment Blue 15:3, phthalocyanine blue pigment)

[0213] [Red pigment]

[0214] B-3: Paliogen Red K3580 (manufactured by BASF, CI Pigment Red 149, perylene red pigment)

[0215] B-4: Cromophtal Scarlet D3540 (manufactured by BASF, CI Pigment Red 166, condensed azo red pigment)

[0216] B-5: TCR12203 Red (manufactured by Trust Chem, CI Pigment Red 122, quinacridone red pigment)

[0217] B-6: Cromophtal Red 2028 (manufactured by BASF, CI Pigment Red 254, diketopyrrolopyrrole red pigment)

[0218] [Purple pigment]

[0219] B-7: Cromophtal Red 2020 (CI Pigment Violet 19, quinacridone violet pigment)

[0220] [Yellow pigment]

[0221] B-8: TCY11002 Yellow (Yellow) (manufactured by Trust Chem, CI Pigment Yellow 110, isoindolinone-based yellow pigment)

[0222] B-9: Paliotol Yellow K0961 (manufactured by BASF, CI Pigment Yellow 138, quinophthalone-based yellow pigment)

[0223] B-10: TCY18001E (manufactured by Trust Chem, CI Pigment Yellow 181, monoazo yellow pigment)

[0224] B-11: Cromophtal Yellow K1410 (manufactured by BASF, CI Pigment Yellow 180, disazo yellow pigment)

[0225] B-12: Cromophtal Yellow K1500 (manufactured by BASF, CI Pigment Yellow 95, condensed azo yellow pigment)

[0226] [Other pigments]

[0227] B-13: Fastogen Green BN (manufactured by DIC Corporation, CI Pigment Green 7, phthalocyanine green pigment)

[0228] B-14: Cromophtal Orange K2960 (manufactured by BASF, CI Pigment Orange 64, monoazo orange pigment)

[0229] B-15: Hiblack 200B (manufactured by Orion Engined Carbons, CI Pigment Black 7, carbon black)

[0230] <Pigment (B) used in Examples and Comparative Examples of <<Example II>>

[0231] [Inorganic pigment (B1x)]

[0232] Examples of B1x-1 include PS24-3950 (manufactured by Fellow, CI Pigment Brown 29, iron-chromium composite pigment)

[0233] B1x-2: Bayferrox 306 (manufactured by LANXESS, CI Pigment Black 11, iron oxide pigment)

[0234] B1x-3: Daipyroxide Black #9590 (manufactured by Dainichi Seika Industries, CI Pigment Black 27, cobalt-iron-chromium composite pigment)

[0235] B1x-4: Bayferrox 303T (manufactured by LANXESS, CI Pigment Black 33, manganese iron oxide composite pigment)

[0236] B1x-5: Tipaque Black SG-101 (manufactured by Ishihara Sangyo Co., Ltd., CI Pigment Black 36, calcium titanium manganese composite pigment)

[0237] B1x-6: Shepherd Black 10P922 (manufactured by Shepherd, CI Pigment Green 17, iron-chromium composite pigment), etc.

[0238] [Organic pigment (B2)]

[0239] (Blue paint)

[0240] B2-1: Lionol Blue FG-7350 (manufactured by Toyocolor, CI Pigment Blue 15:3, phthalocyanine blue pigment)

[0241] (Red Pigment)

[0242] B2-2: Paliogen Red K3580 (manufactured by BASF, CI Pigment Red 149, perylene-based red pigment)

[0243] B2-3: Cromophtal Scarlet D3540 (manufactured by BASF, CI Pigment Red 166, condensed azo red pigment)

[0244] B2-4: TCR12203 Red (manufactured by Trust Chem, CI Pigment Red 122, quinacridone red pigment)

[0245] B2-5: Cromophtal Red 2028 (manufactured by BASF, CI Pigment Red 254, diketopyrrolopyrrole red pigment)

[0246] (Purple pigment)

[0247] B2-6: Cromophtal Red 2020 (CI Pigment Violet 19, quinacridone violet pigment)

[0248] (Yellow Pigment)

[0249] B2-7: TCY11002 Yellow (Yellow) (manufactured by Trust Chem, CI Pigment Yellow 110, isoindolinone-based yellow pigment)

[0250] B2-8: Paliotol Yellow K0961 (manufactured by BASF, CI Pigment Yellow 138, quinophthalone-based yellow pigment)

[0251] B2-9: TCY18001E (manufactured by Trust Chem, CI Pigment Yellow 110181, monoazo yellow pigment)

[0252] B2-10: Cromophtal Yellow K1410 (manufactured by BASF, CI Pigment Yellow 180, disazo yellow pigment)

[0253] B2-11: Cromophtal Yellow K1500 (manufactured by BASF, CI Pigment Yellow 95, condensed azo yellow pigment)

[0254] (Green Pigment)

[0255] B2-12: Fastogen Green BN (manufactured by DIC Corporation, CI Pigment Green 7, phthalocyanine green pigment)

[0256] (Orange Pigment)

[0257] B2-13: Cromophtal Orange K2960 (manufactured by BASF, CI Pigment Orange 64, monoazo orange pigment)

[0258] [Inorganic pigment (B1y)]

[0259] (Inorganic pigments other than inorganic pigments (B1x))

[0260] (Red Pigment)

[0261] B1y-1: Bayferrox 105M (manufactured by LANXESS, CI Pigment Red 101, iron oxide)

[0262] (Blue paint)

[0263] B1y-2: Sicopal Blue K6210 (manufactured by BASF, CI Pigment Blue 28, cobalt blue)

[0264] (Yellow Pigment)

[0265] B1y-3: Daipyroxide Yellow #9120 (manufactured by Dainichi Seika Industries, CI Pigment Yellow 53, titanium-nickel-antimony composite pigment)

[0266] (Black pigment)

[0267] B1y-4: Hiblack 200B (manufactured by Orion Engined Carbons, CI Pigment Black 7, carbon black)

[0268] Embodiment 1

[0269] <Example I-1>

[0270] 99.4 parts of a polyolefin resin (A-1), 0.3 parts of a blue pigment (B-2) "Lionol Blue FG-7350 (manufactured by Toyocolor, CI Pigment Blue 15:3, phthalocyanine blue pigment)", 0.2 parts of a red pigment (B-5) "TCR12203 Red (manufactured by Trust Chem, CI Pigment Red 122, quinacridone red pigment)", and 0.1 parts of a yellow pigment (B-10) "TCY18001E (manufactured by Trust Chem, CI Pigment Yellow 181, monoazo yellow pigment)" were mixed, extruded and granulated at 200°C using a twin-screw extruder (manufactured by The Nippon Steel Works, Ltd.) to obtain a granular black resin composition (C-1).

[0271] <Example I-2 to Example I-16, Comparative Example I-1 to Comparative Example I-5>

[0272] Granular black resin compositions (C-2 to C-21) were obtained in the same manner as in Example 1 except that the materials and blending amounts (parts by mass) were changed to those shown in Table I-1 and Table I-2, respectively.

[0273] (Physical properties and evaluation of resin composition and molded article)

[0274] The physical properties and evaluations of the obtained resin composition and molded article were performed by the following methods.

[0275] The shrinkage rate, visible light transmittance, infrared light transmittance, warpage, brightness, and mechanical visibility were measured and evaluated using the plate-shaped molded articles shown below. In addition, the lid opening torque evaluation was measured and evaluated using the lid-shaped molded articles shown below.

[0276] The results are shown in Table I-1 and Table I-2.

[0277] [Manufacturing of a molded body (plate-shaped molded body)]

[0278] The obtained black resin composition was molded using an injection molding machine (manufactured by Toshiba Machine Co., Ltd.) according to the injection conditions described below, and stored in a constant temperature chamber at 23° C. and 50% RH for one day to obtain a plate-shaped molded body.

[0279] The manufacturing conditions of the molded body (plate-shaped molded body) are to use an injection molding machine (manufactured by Toshiba Machine Co., Ltd.) to continuously injection mold 20 sheets at a molding temperature of 220°C and a mold temperature of 40°C during molding. For evaluation purposes, 6 sheets from the 14th to the 19th sheet were stored in a constant temperature chamber at 23°C and 50% RH for one day after molding. Plate-shaped molded bodies were used.

[0280] In addition, as an evaluation standard, a molded plate obtained by molding only the polyolefin resin (A) under the same conditions (sometimes referred to as "natural") was used.

[0281] The mold used for producing the plate-shaped molded body was a mold for producing a plate having a length of 150 mm, a width of 120 mm, and a thickness of 2 mm, with a marking line of 100 mm provided in the injection direction and in the perpendicular direction.

[0282] [Manufacturing of molded body (lid-shaped molded body)]

[0283] The manufacturing conditions of the molded body (lid-shaped molded body) are as follows: using an injection molding machine (manufactured by Toshiba Machine Co., Ltd.), 20 pieces are continuously injection-molded at a molding temperature of 220°C and a mold temperature of 20°C during molding, a thermoplastic resin suitable as a sealing material is in-shell molded on the inner surface of the lid shell, and the gasket is shaped to produce a lid-shaped molded body with a nominal diameter of 28 mm that can be tightly rolled on the mouth of the container.

[0284] For evaluation, six of the 14th to 19th lid-shaped molded bodies were stored in a constant temperature room at 23° C. and 50% RH for one day after molding.

[0285] <Measurement of shrinkage ratio>

[0286] The distance between the marking lines was measured using a precision vernier caliper using the six obtained plate-shaped molded bodies, and the average shrinkage rate in the injection direction and the direction perpendicular thereto was determined from the measured distance. The shrinkage differential rate was calculated using the following formula.

[0287] Formula (1) ΔMDS=|X1-X0|

[0288] Formula (2) ΔTDS=|Y1-Y0|

[0289] (In addition, X1 and Y1 are respectively the shrinkage rate in the same direction as the injection direction (MD direction) and the shrinkage rate in the direction perpendicular to the injection direction (TD direction) after a molded body with a length of 150 mm, a width of 120 mm and a thickness of 2 mm, which is molded from the black resin composition by an injection molding machine, is left to stand at 23° C. and 50% RH for 24 hours,

[0290] X0 and Y0 are respectively the shrinkage rate in the same direction as the injection direction (MD direction) and the shrinkage rate in the direction perpendicular to the injection direction (TD direction) after a molded body with a length of 150 mm, a width of 120 mm and a thickness of 2 mm formed by an injection molding machine is left to stand at 23°C and 50% RH for 24 hours.

[0291] That is, for example, in Example I-1, a plate-shaped molded body 1 having a length of 150 mm, a width of 120 mm, and a thickness of 2 mm formed by a black resin composition (C-1) by an injection molding machine has a shrinkage rate of X1 in the same direction as the injection direction (MD direction) after being left at 23°C and 50% RH for 24 hours after molding, and a shrinkage rate during shrinkage in a direction perpendicular to the injection direction (TD direction) of Y1. A plate-shaped molded body (natural) having a length of 150 mm, a width of 120 mm, and a thickness of 2 mm formed by a polyolefin resin (A-1) by an injection molding machine has a shrinkage rate of X0 in the same direction as the injection direction (MD direction) after being left at 23°C and 50% RH for 24 hours, and a shrinkage rate during shrinkage in a direction perpendicular to the injection direction (TD direction) of Y0.)

[0292] X1: Shrinkage rate of the plate-shaped molded body 1 in the injection direction

[0293] = Length between marking lines in the MD direction of the plate-shaped molded body 1 after standing at 23°C and 50% RH for 24 hours after molding (mm) / distance between marking lines 100 mm×100

[0294] Y1: Shrinkage rate of the plate-shaped molded body 1 in a direction perpendicular to the injection direction

[0295] = TD direction length between marking lines of the plate-shaped formed body 1 after standing at 23°C and 50% RH for 24 hours after forming (mm) / distance between marking lines 100 mm×100

[0296] X0: Shrinkage ratio in the injection direction of a natural molded product using only the polyolefin resin (A-1)

[0297] = Length between marking lines in the MD direction of the natural molded body after standing at 23°C and 50% RH for 24 hours after molding (mm) / distance between marking lines 100 mm×100

[0298] Y0: Shrinkage ratio of a natural molded product using only the polyolefin resin (A-1) in a direction perpendicular to the injection direction

[0299] = TD direction line length of natural molded body after standing at 23°C and 50% RH for 24 hours after molding mm / line distance 100 mm × 100

[0300] <Average transmittance of visible light and average transmittance of near infrared>

[0301] The transmittance of the obtained plate-shaped molded body was measured at 1 nm intervals in a wavelength range of 380 nm to 2500 nm using an ultraviolet visible spectrophotometer UV-3150 manufactured by Shimadzu Corporation, and the average value of the measured transmittance was determined.

[0302] The average transmittance at a wavelength of 380 nm to 800 nm is recorded in the table as the average transmittance in the visible light region, and the average transmittance at a wavelength of 800 nm to 2500 nm is recorded as the average transmittance in the near infrared region.

[0303] <Warp>

[0304] A 2 kg weight was placed on the gate portion of the obtained plate-shaped molded body, and the height of the body floating from the horizontal position was measured. If it was + or more, it was practical.

[0305] [Evaluation criteria]

[0306] +++: No floating

[0307] ++: The floating height is less than 1mm

[0308] +: The floating height is more than 1mm and less than 2mm

[0309] NG: The floating height exceeds 2 mm

[0310] <Brightness>

[0311] The brightness of the molded article was measured using an image spectrophotometer AU Color COLOR7x manufactured by Kurabo Co., Ltd. using a D-65 (10) standard light source. It can be said that the lower the brightness, the better the design, and if it is + or above, it is practical.

[0312] [Evaluation criteria]

[0313] +++: Brightness less than 1.5

[0314] ++: Brightness is 1.5 or higher and less than 2.0

[0315] +: Brightness is 2.0 or higher and less than 2.5

[0316] NG: Brightness is 2.5 or above

[0317] <Mechanical visibility>

[0318] The obtained molded body plate was identified by using a resin identification handheld sensor (RICOH HANDY PLASTIC SENSOR B150) manufactured by Ricoh Co., Ltd. The closer the correlation coefficient is to 1, the higher the possibility of the resin being the resin, and the better the mechanical visibility using IR (infrared), which means that waste plastics can be classified with high accuracy. If it is + or above, it is practical.

[0319] [Evaluation criteria]

[0320] +++: Correlation coefficient is 0.98 or above

[0321] ++: The correlation coefficient is greater than 0.90 and less than 0.98

[0322] +: The correlation coefficient is 0.75 or more and less than 0.90

[0323] NG: Correlation coefficient is less than 0.75

[0324] <Lid opening torque>

[0325] The obtained cap-shaped molded body is rolled up on a heat-resistant 350 ml polyethylene terephthalate (PET) bottle manufactured by Toyo Can Manufacturing Co., Ltd. and filled with warm water at 87°C using a bottle capping machine, and then subjected to a cooling spray treatment at 75°C-3.5 minutes, 55°C-4.5 minutes, 40°C-4.0 minutes, 30°C-6.0 minutes, and 25°C-2.5 minutes. Using a torque meter (TNX-2, Nidec Shimpo Co., Ltd.), the cap of the prepared evaluation sample is rotated in the opening direction at room temperature, and the opening torque T0 at the start of movement is measured.

[0326] After that, the opening torque T1 of the sample stored in a constant temperature room at 23°C and 50 RH for one week was measured, and the change in opening torque T1-T0 was evaluated as shown below. It can be said that the smaller the change in opening torque, the higher the dimensional stability, and if it is + or above, it is practically applicable.

[0327] [Evaluation criteria]

[0328] +++: T1-T0 less than 0.2N·m

[0329] ++: T1-T0 is 0.2N·m or more and less than 0.4N·m

[0330] +: T1-T0 is 0.4 N·m or more and less than 0.6 N·m NG: T1-T0 is 0.6 N·m or more [Table I-1]

[0331] Table I-1.

[0332]

[0333] [Table I-2]

[0334] Table I-2.

[0335]

[0336] Example II

[0337] <Example II-1>

[0338] 98.58 parts of a polyolefin resin (A-1), 1.40 parts of an inorganic pigment (B1x-1) "PS24-3950 (manufactured by Fellow, CI Pigment Brown 29, an iron-chromium composite pigment)", 0.01 parts of a blue organic pigment (B2-1) "Lionol Blue FG-7350 (manufactured by Toyocolor, CI Pigment Blue 15:3, a phthalocyanine blue pigment", and 0.01 parts of a green organic pigment (B2-13) "Fastogen Green BN (manufactured by DIC, CI Pigment Green 7, a phthalocyanine green pigment)" were mixed, extruded and granulated at 200°C using a twin-screw extruder (manufactured by The Nippon Steel Works, Ltd.) to obtain a granular black resin composition (D-1).

[0339] <Example II-2 to Example II-17, Comparative Example II-1 to Comparative Example II-7>

[0340] Granular black resin compositions (D-2 to D-24) were obtained in the same manner as in Example 1 except that the materials and blending amounts (parts by mass) were changed to those shown in Table II-1 to Table II-3.

[0341] (Physical properties and evaluation of resin composition and molded article)

[0342] The physical properties and evaluations of the obtained resin composition and molded article were performed in the same manner as in Example 1. The shrinkage rate was measured in the same manner as in Example 1 except that the distance between the marking lines was changed as described below. The results are shown in Tables II-1 to II-3.

[0343] <Measurement of shrinkage ratio>

[0344] For example, in Example II-1, a molded body (plate-shaped molded body 1) having a length of 150 mm, a width of 120 mm, and a thickness of 2 mm formed by a black resin composition (D-1) by an injection molding machine, after being left at 23°C and 50% RH for 24 hours after molding, has a shrinkage rate of X1 in the direction (MD direction) which is the same as the injection direction, and a shrinkage rate when shrinking in the direction (TD direction) perpendicular to the injection direction is Y1. A molded body (natural) having a length of 150 mm, a width of 120 mm, and a thickness of 2 mm formed by a polyolefin resin (A-1) by an injection molding machine, after being left at 23°C and 50% RH for 24 hours, has a shrinkage rate of X0 in the direction (MD direction) which is the same as the injection direction, and a shrinkage rate when shrinking in the direction (TD direction) perpendicular to the injection direction is Y0.)

[0345] X1: Shrinkage rate of the plate-shaped molded body 1 in the injection direction

[0346] = MD direction length after forming and standing (mm) / vertical 150mm×100

[0347] Y1: Shrinkage rate of the plate-shaped molded body 1 in a direction perpendicular to the injection direction

[0348] = TD direction length after forming and standing (mm) / horizontal 120mm×100

[0349] X0: Natural shrinkage in the injection direction of the polyolefin resin (A-1) alone

[0350] = MD direction length after natural forming and standing (mm) / vertical 150mm×100

[0351] Y0: natural shrinkage ratio in a direction perpendicular to the injection direction when only the polyolefin resin (A-1) is used

[0352] =Natural TD length after forming and standing mm / horizontal 120mm×100 [Table II-1] Table II-1.

[0353]

[0354] [Table II-2]Table II-2.

[0355]

[0356] [Table II-3]

[0357] Table II-3.

[0358]

[0359] As shown in Tables I-1 and I-2 and Tables II-1 to II-3, the black resin composition of the present invention not only has excellent shielding properties in the visible light region, low brightness, and excellent design properties, but also suppresses warping of the molded body and has good dimensional stability. In addition, since it shows high transmittance in the near-infrared region and has excellent mechanical visibility using IR (infrared rays), it can be confirmed that waste plastics can be classified with high accuracy.

[0360] Furthermore, since the increase in the cap opening torque can be suppressed, it was confirmed that the present invention can also be suitably used for a beverage cap.

Claims

1. A black resin composition comprising a polyolefin resin (A) and a pigment (B), wherein: A molded body having a length of 150 mm, a width of 120 mm and a thickness of 2 mm, which is molded from the black resin composition by an injection molding machine, has an average transmittance of 1% or less at a wavelength of 380 nm to 800 nm, and an average transmittance of 25% or more at a wavelength of 800 nm to 2500 nm, ΔMDS represented by the following formula (1) satisfies 0.35% or less, and ΔTDS represented by the following formula (2) satisfies 0.35% or less. Formula (1) ΔMDS=|X1-X0| Formula (2) ΔTDS=|Y1-Y0| (In addition, X1 and Y1 are respectively the shrinkage rate in the same direction as the injection direction (longitudinal direction) and the shrinkage rate in the direction perpendicular to the injection direction (transverse direction) after a molded body with a length of 150 mm, a width of 120 mm and a thickness of 2 mm, which is molded from the black resin composition by an injection molding machine, is left to stand at 23° C. and a relative humidity of 50% for 24 hours, X0 and Y0 are respectively the shrinkage rate in the same direction as the injection direction (longitudinal direction) and the shrinkage rate in the direction perpendicular to the injection direction (transverse direction) after a molded body with a length of 150 mm, a width of 120 mm and a thickness of 2 mm formed by an injection molding machine is left to stand at 23°C and 50% relative humidity for 24 hours.) 2. The black resin composition according to claim 1, wherein The pigment (B) includes a blue pigment, and at least one of a red pigment and a violet pigment, The red pigment and the violet pigment include at least one selected from the group consisting of color index pigment red 122, color index pigment red 254, and color index pigment violet 19.

3. The black resin composition according to claim 2, wherein The blue pigment is contained in an amount of 100 to 300 parts by mass based on 100 parts by mass of the red pigment and the violet pigment.

4. The black resin composition according to claim 2 or 3, wherein The content of the red pigment and the violet pigment is 20% by mass to 40% by mass based on the total amount of the pigment (B).

5. The black resin composition according to claim 1, wherein The pigment (B) includes an inorganic pigment (B1x), and the inorganic pigment (B1x) is at least any one selected from the group consisting of Color Index Pigment Brown 29, Color Index Pigment Black 11, Color Index Pigment Black 27, Color Index Pigment Black 33, Color Index Pigment Black 36, and Color Index Pigment Green 17.

6. The black resin composition according to claim 5, wherein Pigment (B) also contains other pigments, The other pigment is at least any one of the organic pigment (B2) and the other inorganic pigment (B1y) other than the inorganic pigment (B1x).

7. The black resin composition according to claim 6, wherein The other pigments include at least any one selected from the group consisting of a blue pigment, a red pigment, a violet pigment, a yellow pigment, and a green pigment.

8. The black resin composition according to claim 6 or 7, wherein The organic pigment (B2) includes at least one selected from the group consisting of phthalocyanine blue pigments, phthalocyanine green pigments, diketopyrrolopyrrole red pigments, azo red pigments, quinacridone red pigments, azo yellow pigments, and quinacridone violet pigments. 9 . A molded body formed from the black resin composition according to claim 1 .

10. A cap, which is the formed body according to claim 9.

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