Liquid coloring composition, coloring resin composition, and molded body

Abstract

The problem addressed by the present invention is solved by a liquid coloring composition containing a liquid dispersion medium (A), a surfactant (B), and a coloring agent (C), wherein the liquid dispersion medium (A) has a viscosity of 10,000 mPa·s or less at 25°C and a decomposition start temperature of 250°C or higher, the liquid dispersion medium (A) is at least one substance selected from the group consisting of aliphatic polyester resins, polyalkylene glycol resins, polyether ester resins, and aromatic polyvalent carboxylic acid esters, and the surfactant (B) is at least one substance selected from the group consisting of fatty acid esters, higher fatty acid metal salts, and fatty acid amides.

Description

Liquid colored composition, colored resin composition, and molded article

[0001] The present disclosure relates to a liquid colored composition, a colored resin composition, and a molded article and a colored resin composition.

[0002] Plastic molded articles are easy to mold and process, and are therefore used in a wide range of fields, such as electrical and electronic equipment parts, automobile parts, medical parts, food and beverage containers, etc. Plastic molded articles are colored to enhance their decorative properties, and various coloring compositions are added during molding processes such as injection molding and extrusion molding.

[0003] Examples of the coloring composition include dry colors which are powder coloring compositions, solid masterbatches which are pellet-, granular- or particulate-shaped coloring compositions, and liquid masterbatches which are liquid coloring compositions.

[0004] Dry colors are powdery coloring compositions made by mixing colorants such as dyes and pigments with dispersants, so scattering can cause problems with production lines. Furthermore, even when dry colors are melt-kneaded with the base resin of a molded product, the colorant aggregates cannot be sufficiently loosened, which can result in defective appearances in the molded product.

[0005] A solid masterbatch is a colorant composition prepared by melt-kneading a colorant with a resin or the like and granulating the resulting mixture into granules, and is widely used. However, when a solid masterbatch is used to color a molded product having a low colorant concentration, such as a transparent color, it is difficult to obtain a uniformly colored molded product because the amount of masterbatch added is small, and poor appearance such as color unevenness may occur.

[0006] Known methods for uniformly coloring a molded body include improving molding conditions such as extending the time for melt-kneading the solid masterbatch and diluted resin or strengthening the melt-kneading, and reducing the concentration of the colorant in the solid masterbatch and increasing the amount of solid masterbatch added during molding.

[0007] However, the former method reduces productivity due to the long molding cycle. Furthermore, strong mixing can cause partial decomposition of the resin, resulting in a deterioration in physical properties. The latter method raises concerns about the deterioration of the physical properties of the molded product due to the large amount of solid masterbatch added. In particular, when the diluted resin is polycarbonate resin or polymethyl methacrylate resin, its high mechanical properties make it difficult to plasticize, making it difficult to achieve a uniform, transparent color. In addition, the high processing temperatures of polyester resin and polyamide resin reduce the viscosity of the resin during melting, making it difficult to disintegrate the solid masterbatch containing a high concentration of colorant, making it difficult to achieve a uniform color.

[0008] To solve the above problems, methods using a liquid masterbatch are known, as described in Patent Documents 1 and 2. Because of their liquid state, liquid masterbatches have excellent distributability and can uniformly color plastic molded bodies. Patent Document 1 describes a method in which a liquid masterbatch containing a pigment and vegetable oil is added to a thermoplastic resin, while Patent Document 2 describes a method in which a liquid masterbatch containing a fatty acid ester, solid particles, and a surfactant is added to a specific thermoplastic resin.

[0009] JP 2018-188577 A JP 2023-038867 A JP 2023-089368 A JP 2018-131615 A

[0010] However, the liquid coloring compositions described in Patent Documents 1 and 2 do not have sufficient dispersibility of the colorant. Furthermore, when molding a molded article, there is a problem that the physical properties of the diluted resin are reduced.

[0011] Patent Document 3 discloses a liquid masterbatch containing anatase titanium oxide, a metal deactivator, a liquid dispersion medium having a specified viscosity and thermal decomposition onset temperature, and a dispersant. According to the disclosure of Patent Document 3, even when anatase titanium is contained, thickening due to deterioration of the resin component can be suppressed. However, this technology does not improve the dispersibility and storage stability of the liquid masterbatch or improve supply accuracy, and there is room for further investigation into color unevenness in the resulting molded products and variations in color difference between molded products.

[0012] Patent Document 4 discloses a technology for suppressing color unevenness in the resulting molded article and providing mechanical properties using a liquid coloring composition containing a liquid resin with a specific viscosity, a dispersant having a hindered amine structure, and a colorant. However, the technology disclosed in Patent Document 4 does not consider the dispersibility, storage stability, and supply accuracy of the colorant in the liquid coloring composition, and there is room for further consideration regarding color unevenness in the resulting molded article and variations in color difference between molded articles. Furthermore, color unevenness and variations in these molded articles become apparent in molded articles that have transparency and high mechanical strength, but conventional technologies have not yet been able to solve this problem.

[0013] Therefore, an object of the present disclosure is to provide a liquid coloring composition that has excellent dispersibility of a colorant, good storage stability, and supply accuracy, and that can uniformly color a molded product when kneaded into a diluted resin without impairing the appearance of the molded product or the mechanical properties and moldability of the diluted resin, and that can reduce variation in color difference between molded products.An object of the present disclosure is also to provide a molded product using the same that has excellent color unevenness, appearance, mechanical properties, and moldability.

[0014] The present inventors have conducted extensive research to solve the above problems and have completed the present invention. The present invention includes the following embodiments, but is not limited to the following.

[0015] [1] A liquid coloring composition comprising a liquid dispersion medium (A), a surfactant (B), and a colorant (C), wherein the liquid dispersion medium (A) has a viscosity at 25°C of 10,000 mPa·s or less, a decomposition onset temperature of 250°C or higher, and is at least one selected from the group consisting of an aliphatic polyester resin, a polyalkylene glycol resin, a polyetherester resin, and an aromatic polycarboxylic acid ester, and the surfactant (B) is at least one selected from the group consisting of a fatty acid ester, a higher fatty acid metal salt, and a fatty acid amide. [2] The liquid coloring composition according to [1], wherein the fatty acid ester comprises a triglyceride. [3] The liquid coloring composition according to [1] or [2], wherein the mass ratio (B) / (C) of the content of the surfactant (B) to the content of the colorant (C) is 0.01 to 2. [4] The liquid colored composition according to any one of [1] to [3], which contains 1 to 300 parts by mass of the colorant (C) relative to 100 parts by mass of the liquid dispersion medium (A). [5] The liquid colored composition according to any one of [1] to [4], which contains 0.5 to 30 parts by mass of the surfactant (B) relative to 100 parts by mass of the liquid dispersion medium (A). [6] A colored resin composition comprising the liquid colored composition according to any one of [1] to [5] and a diluent resin (D). [7] The colored resin composition according to [6], wherein the diluent resin (D) is at least one resin selected from the group consisting of polycarbonate resin, acrylic resin, polyester resin, and polyamide resin. [8] A molded article molded from the colored resin composition according to [7].

[0016] The present disclosure provides a liquid coloring composition that is excellent in colorant dispersibility, storage stability, and supply accuracy, and that, when mixed with a diluted resin to form a molded article, can uniformly color the molded article without impairing the appearance, mechanical properties, and moldability of the molded article, and can reduce variation in color difference between molded articles. Furthermore, a colored resin composition using the same can provide a molded article that is excellent in appearance, mechanical properties, and moldability.

[0017] The present disclosure will be described in detail below. Needless to say, other embodiments are also included in the scope of the present disclosure as long as they are consistent with the spirit of the present disclosure. Furthermore, in this specification, a numerical range specified using "to" includes the numerical values ​​written before and after "to" as the range of the lower and upper limits. Here, "liquid" refers to being liquid at 25°C. Unless otherwise noted, the various components appearing in this specification may be used independently, either alone or in combination of two or more.

[0018] Liquid Coloring Composition: The liquid coloring composition can be used as a liquid masterbatch to color molded articles. The liquid coloring composition can be melt-kneaded with a diluent resin, which serves as the main component, when molding a plastic molded article. The liquid coloring composition comprises a liquid dispersion medium (A), a surfactant (B), and a colorant (C). The liquid dispersion medium (A) has a viscosity at 25°C of 10,000 mPa·s or less, a decomposition onset temperature of 250°C or higher, and is at least one selected from the group consisting of aliphatic polyester resins, polyalkylene glycol resins, polyetherester resins, and aromatic polycarboxylic acid esters. The surfactant (B) is at least one selected from the group consisting of fatty acid esters, higher fatty acid metal salts, and fatty acid amides.

[0019] In this way, by using at least one selected from the group consisting of fatty acid esters, higher fatty acid metal salts, and fatty acid amides as the surfactant (B) and dispersing the colorant (C) in a specific liquid dispersion medium (A), a liquid coloring composition with excellent storage stability and supply accuracy can be obtained. Furthermore, by mixing the obtained liquid coloring composition with a diluting resin (D) to form a molded product, it is possible to provide a liquid coloring composition that can be uniformly colored without impairing the appearance, mechanical properties, and moldability of the molded product. As a result, the obtained molded product has excellent appearance, mechanical properties, and moldability.

[0020] <Liquid Dispersion Medium (A)> The liquid dispersion medium serves as a dispersion medium for dispersing a colorant. The liquid coloring composition contains a liquid dispersion medium (A). The liquid dispersion medium (A) has a viscosity at 25°C of 10,000 mPa s or less, a decomposition onset temperature of 250°C or higher, and is at least one selected from the group consisting of an aliphatic polyester resin, a polyalkylene glycol resin, a polyether ester resin, and an aromatic polycarboxylic acid ester.

[0021] The viscosity of the liquid dispersion medium (A) at 25°C is 10,000 mPa s or less, preferably 10 to 7,000 mPa s, and more preferably 20 to 5,000 mPa s, from the viewpoints of dispersibility of the colorant (C) and supply accuracy of the liquid colored composition. From the viewpoints of improving supply accuracy and reducing variation in color difference between the obtained molded products, the viscosity of the liquid dispersion medium (A) at 25°C may be 600 mPa s or less, 500 mPa s or less, 200 mPa s or less, or 100 mPa s or less. The viscosity in this specification is a value measured using a B-type viscometer in accordance with JIS K7117-1.

[0022] The decomposition initiation temperature of the liquid dispersion medium (A) is 250°C or higher, preferably 260°C or higher, and more preferably 270°C or higher, from the viewpoint of the moldability and appearance of the molded body. The upper limit of the decomposition initiation temperature is not particularly limited, but from the viewpoint of the viscosity of the liquid dispersion medium (A), it is preferably 320°C or lower. The decomposition initiation temperature in this specification is the temperature at which a 10% loss on heating occurs when the temperature is increased at a heating rate of 10°C / min using a "STA7200" manufactured by Hitachi High-Tech Science Corporation.

[0023] The freezing point of the liquid dispersion medium (A) is preferably −5° C. or lower, more preferably −50° C. to −10° C. In this specification, the freezing point is a value measured in accordance with JIS K0065.

[0024] The liquid dispersion medium (A) contains at least one selected from the group consisting of an aliphatic polyester resin, a polyalkylene glycol resin, a polyetherester resin, and an aromatic polycarboxylic acid ester. From the viewpoint of compatibility with the diluent resin (D), when the diluent resin (D) is a polycarbonate resin, the liquid dispersion medium (A) is preferably an aliphatic polyester resin or an aromatic polycarboxylic acid ester. When the diluent resin (D) is an acrylic resin or a polyamide resin, the liquid dispersion medium (A) is preferably a polyalkylene glycol resin or a polyetherester resin. When the diluent resin (D) is a polyester resin, the liquid dispersion medium (A) is preferably an aliphatic polyester resin, a polyalkylene glycol resin, or a polyetherester resin. Even in such a combination of the liquid dispersion medium (A) and the diluent resin (D), the use of the surfactant (B) can further improve the dispersibility, storage stability, and supply accuracy of the liquid coloring composition, prevent a decrease in the mechanical strength of the resulting molded article, and suppress the occurrence of variations in color difference between molded articles. In particular, when a polycarbonate resin is used as the diluent resin (D), compatibility with the liquid coloring composition is usually difficult to obtain, but the use of the surfactant (B) can exhibit excellent effects.

[0025] [Aliphatic Polyester Resin] The aliphatic polyester resin is a polyester resin obtained by reacting an aliphatic polycarboxylic acid with a polyhydric alcohol.

[0026] The aliphatic polycarboxylic acid constituting the aliphatic polyester resin is not particularly limited as long as it is an aliphatic carboxylic acid having two or more carboxyl groups, and examples thereof include succinic acid, maleic acid, fumaric acid, glutaric acid, adipic acid, sebacic acid, dodecanedicarboxylic acid, tricarballylic acid, 1,3,6-hexatricarboxylic acid, 1,3,5-hexatricarboxylic acid, etc. These aliphatic carboxylic acids may be used alone or in combination of two or more.

[0027] The polyhydric alcohol constituting the aliphatic polyester resin is not particularly limited as long as it is an alcohol having two or more hydroxyl groups, and examples thereof include aliphatic glycols such as ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,2-butanediol, 1,3-butanediol, 2-methyl-1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,8-octanediol, 1,10-decanediol, and 1,12-octadecanediol, and polyalkylene glycols such as diethylene glycol and dipropylene glycol. These may be used alone or in combination of two or more.

[0028] Specific examples of aliphatic polyester resins include Adeka Cizer PN-7160 (manufactured by ADEKA Corporation, viscosity 150 mPa s (25°C), freezing point -42°C, adipic acid polyester resin), Adeka Cizer PN-5090 (manufactured by ADEKA Corporation, viscosity 10,000 mPa s (25°C), freezing point -10°C, adipic acid polyester resin), and the like.

[0029] [Polyalkylene glycol resin] Polyalkylene glycol resins are generally composed of alkylene glycols having a repeating unit with 1 to 6 carbon atoms, but various polyalkylene glycols can be used as long as their viscosity at 25° C. is 10,000 mPa·s or less. From the viewpoints of compatibility and water absorbency, polyalkylene glycol resins having a repeating unit with 2 to 4 carbon atoms are preferred.

[0030] Specific examples of polyalkylene glycol resins include polyethylene glycol, which has two carbon atoms in the repeating unit, polypropylene glycol, which has three carbon atoms in the repeating unit, and polybutylene glycol, which has four carbon atoms in the repeating unit.

[0031] Specific examples of polyalkylene glycol resins include PEG#300 (manufactured by NOF Corporation, viscosity 70 mPa·s (25°C), polyethylene glycol) and Uniol D-1200 (manufactured by NOF Corporation, viscosity 200 mPa·s (25°C), polypropylene glycol).

[0032] [Polyetherester Resin] The polyetherester resin is obtained by esterifying an aliphatic polycarboxylic acid with an alkylene glycol, and the above-mentioned aliphatic polycarboxylic acid and the above-mentioned alkylene glycol can be used.

[0033] Specific examples of polyetherester resins include Adeka Cizer RS-107 (manufactured by ADEKA Corporation, viscosity 20 mPa s (25°C), freezing point -47°C) and Adeka Cizer RS-700 (manufactured by ADEKA Corporation, viscosity 30 mPa s (25°C), freezing point -53°C).

[0034] [Aromatic polycarboxylic acid ester] The aromatic polycarboxylic acid ester is an ester compound obtained by the reaction of an aromatic polycarboxylic acid with an alcohol. The aromatic polycarboxylic acid ester may be either a low molecular weight compound or a high molecular weight compound. In one example, the aromatic polycarboxylic acid ester may be an esterification product of an aromatic polycarboxylic acid with a monoalcohol. In another example, the aromatic polycarboxylic acid ester may be a polycondensation product of an aromatic polycarboxylic acid with a polyhydric alcohol, or a polycondensation product of an aromatic polycarboxylic acid with a glycol.

[0035] The aromatic polycarboxylic acid constituting the aromatic polycarboxylic acid ester is not particularly limited as long as it is an aromatic carboxylic acid having two or more carboxyl groups, and examples thereof include aromatic polycarboxylic acids such as phthalic acid, isophthalic acid, terephthalic acid, trimellitic acid, pyromellitic acid, etc. These aliphatic carboxylic acids may be used alone or in combination of two or more.

[0036] The alcohol constituting the aromatic polycarboxylic acid ester is not particularly limited, and examples thereof include: (1) linear alkyl alcohols such as methanol, ethanol, propanol, butanol, pentanol, hexanol, octanol, nonanol, decanol, undecanol, dodecanol, tridecanol, tetradecanol, pentadecanol, hexadecanol, heptadecanol, octadecanol, nonadecanol, eicosanol, heneicosanol, docosanol, tricosanol, tetracosanol, pentacosanol, hexacosanol, heptacosanol, octacosanol, nonacosanol, and triacontanol; and (2) isopropanol, isobutanol, isohexanol, 2-ethylhexanol, isononanol, isodecanol, isododecanol, and isotridecanol. (3) branched alkyl alcohols such as tetradecenol, isotetradecanol, isopentadecanol, isohexadecanol, isoheptadecanol, isooctadecanol, isononadecanol, isoeicosanol, isoheneicosanol, isodocosanol, isotricosanol, isotetracosanol, 2-decyltetradecanol, isopentacosanol, isohexacosanol, isoheptacosanol, isooctacosanol, isononacosanol, and isotriacontanol; (4) linear alkenyl alcohols such as tetradecenol, hexadecenol, heptadecenol, octadecenol, oleyl alcohol, and nonadecenol; (4) branched alkenyl alcohols such as isohexadecenol and isooctadecenol; and (5) cyclic alkyl alcohols such as cyclopentanol and cyclohexanol. Furthermore, polyhydric alcohols may also be used, and examples of polyhydric alcohols include aliphatic glycols such as ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,2-butanediol, 1,3-butanediol, 2-methyl-1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,8-octanediol, 1,10-decanediol, and 1,12-octadecanediol, and polyalkylene glycols such as diethylene glycol and dipropylene glycol.Further examples include alkylene glycol alkyl ethers, polyalkylene glycol alkyl ethers, and acetate salts thereof in which the hydroxy groups, except for at least one hydroxy group, of these polyhydric alcohols are substituted with alkyl groups. These may be used alone, or two or more types may be used. Among these, monohydric aliphatic alcohols are preferred. Monohydric branched aliphatic alkyl alcohols are particularly preferred. The number of carbon atoms in the alcohol may be 3 to 22, 4 to 18, or 6 to 12, and it is even more preferred if the number of carbon atoms in the monohydric branched aliphatic alkyl alcohol is within these ranges.

[0037] Specific examples of aromatic polycarboxylic acid esters include Adeka Cizer UL-80 (manufactured by ADEKA Corporation, viscosity 450 mPa·s (25°C), pyromellitic acid 2-ethylhexyl ester), Adeka Cizer UL-100 (manufactured by ADEKA Corporation, viscosity 176 mPa·s (25°C), pyromellitic acid alkyl ester), and the like.

[0038] The liquid dispersion medium (A) may be one of the above-mentioned various resins, or a combination of two or more of them. Since the liquid dispersion medium (A) serves as a dispersion medium for the colorant (C), the liquid coloring composition does not need to contain any components other than the resin as an additional liquid dispersion medium. For example, the liquid coloring composition may be a non-aqueous liquid coloring composition, and may not substantially contain water relative to the total mass of the liquid coloring composition, for example, it may be less than 1 mass%.

[0039] <Surfactant (B)> The surfactant (B) is at least one selected from the group consisting of fatty acid esters, higher fatty acid metal salts, and fatty acid amides, with fatty acid esters or higher fatty acid metal salts being preferred. By including these compounds, the liquid coloring composition can improve the dispersibility of the colorant (C) and maintain storage stability. Furthermore, by including these compounds, the supply accuracy of the liquid coloring composition can be improved. By improving the supply accuracy of the liquid coloring composition, the variation in color difference between molded articles obtained can be reduced. This can be more effectively confirmed against the phenomenon of variation in color difference between molded articles obtained even when no clear difference in supply accuracy is observed in the liquid coloring composition. Here, the surfactant refers to a compound having a hydrophilic group and a lipophilic group in its molecule, which has the function of reducing interfacial tension by strong adsorption to the interface of immiscible substances and molecular orientation.

[0040] The surfactant (B) can also function as a dispersant in the liquid colored composition. Here, the dispersant means a substance that interacts with the colorant and has the role of uniformly dispersing the colorant in the liquid dispersion medium.

[0041] The use of the liquid dispersion medium (A) and the surfactant (B) makes it possible to provide a liquid coloring composition that has excellent dispersibility of the colorant (C), good storage stability, and supply accuracy, and that can uniformly color a molded product when kneaded into a diluted resin (D) without impairing the appearance, mechanical properties, or moldability of the molded product. When the surfactant (B) contains at least one of a fatty acid ester, a higher fatty acid metal salt, and a fatty acid amide, supply accuracy can be further improved and variation in color difference between molded products can be reduced.

[0042] The surfactant (B) has a strong interaction with the colorant (C), thereby further enhancing the dispersibility of the colorant (C). Therefore, even when the colorant (C) is at least one of an inorganic pigment and a dye, the dispersibility of the liquid coloring composition is not reduced, and the storage stability and supply accuracy can be improved. This makes it possible to provide molded articles that are uniformly colored and have excellent appearance, while suppressing a decrease in strength. Furthermore, it is possible to reduce the variation in color difference between the resulting molded articles.

[0043] When molding a molded article using a colored resin composition containing a liquid colored composition and a diluted resin (D), variation in color difference between molded articles may occur between molded articles continuously molded by injection molding, extrusion molding, etc. In addition, in injection molding, one part is molded per shot, and variation in color difference may occur between parts.

[0044] [Fatty Acid Ester] Fatty acid esters have a structure in which one or more fatty acids are ester-bonded to an alcohol. Examples of the alcohol include monohydric and polyhydric alcohols. Preferably, the number of oxygen atoms is 8 or less. The monohydric alcohol is preferably a higher alcohol having 6 or more carbon atoms, more preferably a higher alcohol having 10 or more carbon atoms. Examples include myristyl alcohol, stearyl alcohol, and oleyl alcohol. Examples of polyhydric alcohols include dihydric alcohols such as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, neopentyl glycol, and 1,6-hexanediol; and trihydric or higher alcohols such as glycerin, diglycerin, triglycerin, trimethylolethane, trimethylolpropane, pentaerythritol, dipentaerythritol, mannitol, and sorbitol. Among these, glycerin, propylene glycol, pentaerythritol, and dipentaerythritol are preferred, and glycerin and dipentaerythritol are more preferred.

[0045] The fatty acid constituting the fatty acid ester is a monocarboxylic acid having a carboxy group on the hydrocarbon chain. Examples include saturated fatty acids such as caproic acid, caprylic acid, capric acid, undecylic acid, lauric acid, tridecylic acid, myristic acid, palmitic acid, stearic acid, behenic acid, lignocenic acid, cerotic acid, montanic acid, and melissic acid; unsaturated fatty acids such as oleic acid, elaidic acid, linoleic acid, linolenic acid, arachidonic acid, prasidic acid, erucic acid, and ricinoleic acid; hydroxy fatty acids such as 12-hydroxystearic acid; and aliphatic dicarboxylic acids such as adipic acid. Fatty acids having 6 or more carbon atoms are preferred, and fatty acids having 13 or more carbon atoms are more preferred. Among these, myristic acid, palmitic acid, stearic acid, oleic acid, erucic acid, and 12-hydroxystearic acid are preferred, with stearic acid and 12-hydroxystearic acid being particularly preferred. Triglycerides are particularly preferred as the fatty acid ester.

[0046] Triglycerides are esters of fatty acids and glycerin. The carbon atoms of the fatty acids in triglycerides are preferably 10 to 22, more preferably 12 to 20, and even more preferably 14 to 18. The three fatty acids constituting a triglyceride may be the same or some or all of them may be different. Fatty acids in triglycerides include long-chain fatty acids such as stearic acid, lauric acid, ricinoleic acid, octylic acid, montanic acid, and palmitic acid, and derivatives thereof, with fatty acids having hydroxy groups being particularly preferred. Examples of triglycerides include castor oil, coconut oil, olive oil, and hydrogenated products thereof, with hydrogenated castor oil being particularly preferred.

[0047] Hydrogenated castor oil is a hardened castor oil obtained by adding hydrogen to the unsaturated bonds of castor oil, and is a triglyceride of 12-hydroxystearic acid. Specific examples of hydrogenated castor oil include Kawastar CR (manufactured by Kawaken Fine Chemicals Co., Ltd.).

[0048] The higher fatty acid metal salt is a metal salt of a higher fatty acid, preferably a non-alkali metal salt of a higher fatty acid. The number of carbon atoms in the fatty acid of the higher fatty acid metal salt is preferably 10 to 22, more preferably 12 to 20, and even more preferably 14 to 18. Examples of fatty acids in the higher fatty acid metal salt include long-chain fatty acids such as stearic acid, lauric acid, ricinoleic acid, octylic acid, montanic acid, and palmitic acid, and their derivatives. The fatty acids in the higher fatty acid metal salt may have a substituent such as a hydroxy group to enhance adsorption to the colorant (C). Examples of metals include lithium, magnesium, calcium, barium, and zinc, with alkaline earth metals being preferred, and magnesium being more preferred. Due to their good adsorption to the colorant (C), magnesium stearate and its derivatives are preferred as the metal soap, with 12-hydroxymagnesium stearate being more preferred. Specific examples of higher fatty acid metal salts include Sinaka Red SAK-MS-P (manufactured by San-Ace Co., Ltd., magnesium stearate) and MS-6 (manufactured by Nitto Kasei Kogyo Co., Ltd., 12-hydroxy magnesium stearate).

[0049] [Fatty Acid Amide] Fatty acid amide has a structure in which one or more fatty acids are amide-bonded to an amine. Examples of the amine include monovalent and polyvalent amines. Preferred monovalent amines are ammonia and amines having 10 or more carbon atoms. Examples include oleylamine and stearylamine. Preferred polyvalent amines have 3 or less nitrogen atoms. Among these, diamines having 6 or less carbon atoms, such as ethylenediamine and hexamethylenediamine, are preferred.

[0050] Examples of fatty acids constituting the fatty acid amide include the above-mentioned fatty acids, preferably long-chain fatty acids having 13 or more carbon atoms, more preferably stearic acid, 12-hydroxystearic acid, and erucic acid.

[0051] Examples of fatty acid amides include aliphatic monocarboxylic acid amides such as lauric acid amide, palmitic acid amide, oleic acid amide, stearic acid amide, erucic acid amide, behenic acid amide, ricinoleic acid amide, and hydroxystearic acid amide; N-substituted aliphatic monocarboxylic acid amides such as N-oleyl oleic acid amide, N-oleyl stearic acid amide, and N-stearyl oleic acid amide; aliphatic biscarboxylic acid amides such as methylene bisstearic acid amide and ethylene bisstearic acid amide; N,N'-ethylene bis-oleyl amide; N,N'-ethylene bisstearic acid amide; and N,N'-methylene bisstearic acid amide. Preferred are stearic acid amide, erucic acid amide, and N,N'-ethylene bisstearic acid amide.

[0052] The acid value of the surfactant (B) is preferably 180 mgKOH / g or less, and more preferably 140 mgKOH / g or less, from the viewpoint of the dispersibility of the colorant (C) and the mechanical properties due to the compatibility with the diluent resin (D).

[0053] The amine value of the surfactant (B) is preferably 180 mgKOH / g or less, and more preferably 140 mgKOH / g or less, from the viewpoint of the dispersibility of the colorant (C) and the mechanical properties due to the compatibility with the diluent resin (D), for example, the ability to suppress a decrease in the deflection temperature under load.

[0054] From the viewpoint of mechanical properties due to the compatibility of the colorant (C) and the diluent resin (D), for example, to suppress a decrease in the deflection temperature under load, the content of the surfactant (B) is preferably 0.5 parts by mass or more, more preferably 0.8 parts by mass or more, and even more preferably 1 part by mass or more, relative to 100 parts by mass of the liquid dispersion medium (A). Also, it is preferably 30 parts by mass or less, more preferably 20 parts by mass or less, and even more preferably 15 parts by mass or less. When the surfactant (B) contains two or more of fatty acid esters, higher fatty acid metal salts, and fatty acid amides, the total amount thereof is preferably within the above range.

[0055] The liquid coloring composition may further contain other surfactants in addition to the fatty acid ester, higher fatty acid metal salt, fatty acid amide, or a combination thereof. Furthermore, the liquid coloring composition may further contain a dispersant.

[0056] A dispersant-type acrylic resin can be used as the dispersant. The acrylic resin is a polymer containing structural units derived from a (meth)acrylic monomer, and examples thereof include a (meth)acrylic resin and a styrene-acrylic resin. The acrylic resin preferably has at least one polymer block composed of structural units derived from a (meth)acrylic monomer.

[0057] The weight-average molecular weight of the acrylic resin is preferably 500 to 20,000, more preferably 1,000 to 15,000, from the viewpoint of solubility in the liquid dispersion medium (A) and the physical properties of the diluent resin (D). In this specification, the weight-average molecular weight is a value measured by gel permeation chromatography (GPC method) (a measured value obtained using polystyrene as a standard substance and tetrahydrofuran as an eluent).

[0058] Examples of (meth)acrylic monomers constituting acrylic resins include (meth)acrylic acid, methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, amyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, octyl (meth)acrylate, nonyl (meth)acrylate, dodecyl (meth)acrylate, hexadecyl (meth)acrylate, octadecyl (meth)acrylate, cyclohexyl (meth)acrylate, benzyl (meth)acrylate, methoxyethyl (meth)acrylate, butoxyethyl (meth)acrylate, and phenoxyethyl (meth)acrylates such as (meth)acrylate, nonylphenoxyethyl (meth)acrylate, glycidyl (meth)acrylate, dimethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate, isobornyl (meth)acrylate, dicyclopentanyl (meth)acrylate, dicyclopentenyl (meth)acrylate, and dicyclopentenyloxyethyl (meth)acrylate; (meth)acrylic acid or esters thereof; and mono(meth)acrylates having a (poly)alkylene glycol group such as (poly)ethylene glycol, (poly)propylene glycol, and (poly)butylene glycol.

[0059] The styrene-acrylic resin is a copolymer of a styrene monomer and the above-mentioned (meth)acrylic monomer. Examples of the styrene monomer include styrene and α-methylstyrene. The styrene-acrylic resin is preferably a polymer having a styrene polymer block and a (meth)acrylic polymer block.

[0060] The acrylic resin may have a functional group, and examples of the functional group include a hydroxyl group, a carboxyl group, an epoxy group, an alkyl group, and an alkoxysilyl group.

[0061] Specific examples of the acrylic resin include Arfon UP-1000 (manufactured by Toagosei Co., Ltd., weight average molecular weight 3,000, acrylic resin) and Arfon UP-2170 (manufactured by Toagosei Co., Ltd., weight average molecular weight 14,000, styrene-acrylic resin).

[0062] Phosphate ester compounds are surfactants and can also be used as dispersants. Examples of phosphate ester compounds include alkyl phosphates such as tributyl phosphate, trioctyl phosphate, tris(β-chloroethyl)phosphate, tris(β-chloropropyl)phosphate, and tris(dichloropropyl)phosphate; phenyl phosphates such as triphenyl phosphate, tricresyl phosphate, tris(i-properphenyl)phosphate, cresyl diphenyl phosphate, and octyl diphenyl phosphate; alkyl polyoxyethylene phosphate esters such as tributoxyethyl phosphate; and alkylphenol polyoxyethylene phosphate esters, as well as their neutralized salts with sodium, potassium, ammonia, amine, or the like. These phosphate ester compounds may also have an acid value or an amine value. These phosphate ester compounds may be used alone or in combination of two or more. From the viewpoint of the dispersibility and storage stability of the colorant (C), the phosphate ester compound is preferably an alkyl polyoxyethylene phosphate ester or alkylphenol polyoxyethylene phosphate ester having an acid value or an amine value.

[0063] Specific examples of the phosphate ester compound include ADEKA REASOAP PP-70 (manufactured by ADEKA Corporation, phosphate ester), DISPER BYK-102 (manufactured by BYK-Chemie, acid value 101 mgKOH / g), and DISPER BYK-145 (manufactured by BYK-Chemie, acid value 76 mgKOH / g, amine value 71 mgKOH / g).

[0064] When other surfactants and dispersants are used in addition to the fatty acid ester, higher fatty acid metal salt, fatty acid amide, or combinations thereof, the total amount of the other surfactants and dispersants may be 0 to 50 parts by mass, 0 to 20 parts by mass, or 0 to 10 parts by mass per 100 parts by mass of the surfactant (B). Even when no other surfactants and dispersants are used, the use of the fatty acid ester, higher fatty acid metal salt, fatty acid amide, or combinations thereof can be expected to provide the desired effects of the liquid colored composition, and can also provide the desired effects of the resulting molded product.

[0065] <Colorant (C)> The colorant (C) is not particularly limited, and commonly used dyes, pigments, etc. can be used. Examples of dyes include methine dyes, perinone dyes, anthraquinone dyes, etc. Examples of pigments include inorganic pigments such as titanium oxide, chrome titanium iron, red iron oxide, ultramarine, and carbon black, and organic pigments such as azo pigments, quinacridone pigments, perylene pigments, diketopyrrolopyrrole pigments, and phthalocyanine pigments. Rutile titanium oxide is preferred over anatase titanium oxide because it has lower activity and is less likely to induce resin deterioration. Pigments are preferred from the viewpoint of heat resistance, and dyes are preferred from the viewpoint of transparency.

[0066] Examples of the methine dyes include C.I. Solvent Yellow 93 and 179. Examples of the perinone dyes include C.I. Solvent Red 135 and 179, and examples of the anthraquinone dyes include C.I. Solvent Red 52 and 151, Solvent Violet 13 and 36, and Solvent Blue 97. "C.I." stands for Color Index.

[0067] Specific examples of the methine dyes include Macrolex Yellow 3G-FG (manufactured by Lanxess, Solvent Yellow 93) and Macrolex Yellow 6G (manufactured by Lanxess, Solvent Yellow 179). Specific examples of the perinone dyes include Macrolex Red EG GRAN (manufactured by Lanxess, Solvent Red 135) and Macrolex Red E2G GRAN (manufactured by Lanxess, Solvent Red 179). Specific examples of the anthraquinone dye include Sumiplast Red HL5B (manufactured by Sumika Chemtex Co., Ltd., Solvent Red 52), Sumiplast Red HL2B (manufactured by Sumika Chemtex Co., Ltd., Solvent Red 151), Macrolex Violet B-FG (manufactured by Lanxess AG, Solvent Violet 13), Macrolex Violet 3R-FG (manufactured by Lanxess AG, Solvent Violet 36), and Macrolex Blue RR GRAN (manufactured by Lanxess AG, Solvent Blue 97).

[0068] Examples of the inorganic pigments include C.I. Pigment White 6, Pigment Brown 24, Pigment Red 101, Pigment Blue 29, and Pigment Black 7. Examples of the organic pigments include the following organic pigments. Examples of the azo pigments include C.I. Pigment Yellow 180 and 181, Pigment Orange 64, and Pigment Red 144, 166, 214, and 221. Examples of the quinacridone pigments include C.I. Pigment Violet 19 and Pigment Red 122. Examples of the perylene pigments include C.I. Pigment Red 149 and 178. Examples of the diketopyrrolopyrrole pigments include C.I. Pigment Red 254. Examples of the phthalocyanine pigments include C.I. Pigment Blue 15:1, 15:3, Pigment Green 7, 36, etc. These colorants (C) may be used alone or in combination of two or more.

[0069] Specific examples of the inorganic pigment include Typec PF-740 (manufactured by Ishihara Sangyo Kaisha, Ltd., rutile-type titanium oxide, Pigment White 6), Tomatec 42-118A (manufactured by Tokan Material Technology Co., Ltd., Pigment Brown 24), Todacolor 120ED (manufactured by Toda Kogyo Co., Ltd., Pigment Red 101), and Ultramarine No. 1500 (manufactured by Daiichi Chemical Industry Co., Ltd., Pigment Blue 29). Specific examples of the organic pigment include the following: Specific examples of the azo pigments include PV Fast Yellow HG (Pigment Yellow 180, manufactured by Clariant), PV Fast Yellow H3R (Pigment Yellow 181, manufactured by Clariant), Cromophtal Orange K2960 (Pigment Orange 64, manufactured by BASF), Cromophtal Red K3890FP (Pigment Red 144, manufactured by BASF), Cromophtal Scarlet K3540 (Pigment Red 166, manufactured by BASF), Cromophtal Red K3900 (Pigment Red 214, manufactured by BASF), and Cromophtal Red K4035 (Pigment Red 221, manufactured by BASF). Specific examples of the quinacridone pigments include PV Fast Red E4G (Pigment Violet 19, manufactured by Clariant) and PV Fast Pink E-01 (Pigment Red 122, manufactured by Clariant). Specific examples of the perylene pigments include Paliogen Red K3580 (Pigment Red 149, manufactured by BASF) and Paliogen Red K3911 (Pigment Red 178, manufactured by BASF). Specific examples of the diketopyrrolopyrrole pigments include Irgazin Red K3840 (Pigment Red 254, manufactured by BASF). Specific examples of the phthalocyanine pigment include Lionol Blue CB7801 (manufactured by Toyocolor Co., Ltd., Pigment Blue 15:1), Lionol Blue FG7351 (manufactured by Toyocolor Co., Ltd., Pigment Blue 15:3), Lionol Green Y-102 (manufactured by Toyocolor Co., Ltd., Pigment Green 7), and Lionol Green 6Y-501 (manufactured by Toyocolor Co., Ltd., Pigment Green 36).

[0070] The content of the colorant (C) in the liquid colored composition is preferably 1 to 300 parts by mass, more preferably 5 to 250 parts by mass, relative to 100 parts by mass of the liquid dispersion medium (A), from the viewpoints of the dispersibility of the colorant (C) and the supply accuracy of the liquid colored composition.

[0071] When the colorant (C) is an inorganic pigment, the surfactant (B) can further improve dispersibility by including at least one of a fatty acid ester, a higher fatty acid metal salt, and a fatty acid amide, with hydrogenated castor oil being more preferred. When the colorant (C) is a dye, the surfactant (B) can further improve dispersibility by including at least one of a fatty acid ester, a higher fatty acid metal salt, and a fatty acid amide, with hydrogenated castor oil being more preferred. When the colorant (C) is an organic pigment, the surfactant (B) can further improve dispersibility by including at least one of a fatty acid ester, a higher fatty acid metal salt, and a fatty acid amide, but from the viewpoint of dispersibility, it is preferable to use an acrylic resin as a dispersant. Using these surfactants (B) can further improve the adsorption to the colorant (C), improving the sedimentation stability of the colorant (C), and enabling the liquid colored composition to achieve both dispersibility and storage stability.

[0072] From the viewpoint of dispersibility of the colorant (C) and storage stability, the content ratio (B) / (C) of the content of the surfactant (B) to the content of the colorant (C) is preferably from 0.01 to 2, more preferably from 0.05 to 1, and even more preferably from 0.1 to 0.5.

[0073] The total amount of the liquid dispersion medium (A), surfactant (B), and colorant (C) in the liquid coloring composition is preferably 50 to 100 parts by mass, more preferably 70 to 100 parts by mass, and even more preferably 80 to 100 parts by mass, relative to 100 parts by mass of the liquid coloring composition, from the viewpoints of dispersibility and storage stability.

[0074] <Other Additives> The liquid coloring composition may contain any other polymer, antistatic agent, antifoaming agent, matting agent, fluorescent brightener, stabilizer, antioxidant, viscosity modifier, and other additives. Furthermore, the liquid coloring composition may contain a liquid dispersion medium other than the liquid dispersion medium (A), a surfactant other than the surfactant (B), and a dispersant, as long as the effects of the present disclosure are not impaired.

[0075] <Method for producing liquid colored composition> The method for producing the liquid colored composition is not particularly limited, and for example, the liquid dispersion medium (A), the surfactant (B), the colorant (C), and, if necessary, other additives are added, mixed using a Henschel mixer, a tumbler, a disperser, or the like, and dispersed using a Silverson mixer (manufactured by Silverson) or the like, to obtain a liquid colored composition. In addition to the above, any other dispersing device can be used, such as a kneader, a roll mill, a ball mill, or a sand mill. It is preferable to use a bead mill, a Silverson mixer, or a roll mill because they are easy to mold and have excellent dispersibility.

[0076] <<Colored Resin Composition>> The colored resin composition contains the liquid colored composition and diluted resin (D) described above, and is used to mold a molded body. The diluted resin (D) is a base resin that is colored by the liquid colored composition when molding the molded body, and is the main component of the molded body. A thermoplastic resin is mainly used, and is appropriately selected according to the application of the molded body.

[0077] The content of the liquid coloring composition is preferably 0.001 parts by mass or more, more preferably 0.005 parts by mass or more, relative to 100 parts by mass of the diluted resin (D). It is also preferably 10 parts by mass or less, more preferably 5 parts by mass or less, even more preferably 1 part by mass or less, and particularly preferably 0.5 parts by mass or less. This allows for improved processability and mechanical properties. Furthermore, molded articles with excellent appearance can be obtained without color unevenness or colorant aggregates.

[0078] The resin to be colored by the liquid coloring composition is not particularly limited, but examples of the diluent resin (D) include polycarbonate resin, acrylic resin, polyester resin, polyamide resin, polyvinyl chloride resin, polystyrene resin, and cycloolefin copolymer (COC). The liquid coloring composition of the present invention can also be used to suitably color polycarbonate resin, acrylic resin, polyester-based resin, and polyamide-based resin, which are generally difficult to color uniformly. The acrylic resin is preferably polymethyl methacrylate resin.

[0079] [Polycarbonate Resin] Polycarbonate resins can be easily produced by reacting an aromatic dihydroxy compound with a carbonate precursor such as phosgene or a carbonate diester, etc. The reaction can be carried out by a known reaction method, for example, an interfacial method when phosgene is used, or a transesterification method in which the reaction is carried out in a molten state when a carbonate diester is used.

[0080] Examples of the aromatic dihydroxy compound include bis(hydroxyaryl)alkanes such as 2,2-bis(4-hydroxyphenyl)propane (bisphenol A), bis(4-hydroxyphenyl)methane, 1,1-bis(4-hydroxyphenyl)ethane, 2,2-bis(4-hydroxyphenyl)butane, 2,2-bis(4-hydroxyphenyl)octane, bis(4-hydroxyphenyl)phenylmethane, 2,2-bis(4-hydroxy-3-methylphenyl)propane, 1,1-bis(4-hydroxy-3-t-butylphenyl)propane, 2,2-bis(4-hydroxy-3-bromophenyl)propane, 2,2-bis(4-hydroxy-3,5-dibromophenyl)propane, and 2,2-bis(4-hydroxy-3,5-dichlorophenyl)propane; Examples of suitable hydroxyaryl compounds include bis(hydroxyaryl)cycloalkanes such as 1,1-bis(4-hydroxyphenyl)cyclopentane and 1,1-bis(4-hydroxyphenyl)cyclohexane; dihydroxydiaryl ethers such as 4,4'-dihydroxydiphenyl ether and 4,4'-dihydroxy-3,3'-dimethyldiphenyl ether; dihydroxydiaryl sulfides such as 4,4'-dihydroxydiphenyl sulfide and 4,4'-dihydroxy-3,3'-dimethyldiphenyl sulfide; dihydroxydiaryl sulfoxides such as 4,4'-dihydroxydiphenyl sulfoxide and 4,4'-dihydroxy-3,3'-dimethyldiphenyl sulfoxide; and dihydroxydiaryl sulfones such as 4,4'-dihydroxydiphenyl sulfone and 4,4'-dihydroxy-3,3'-dimethyldiphenyl sulfone. These compounds may be used alone or in combination of two or more. In addition to these compounds, piperazine, dipiperidyl hydroquinone, resorcinol, and 4,4'-dihydroxydiphenyl compounds may also be used in combination. Furthermore, branched aromatic polycarbonate resins containing polyfunctional compounds such as phloroglucin can also be used.

[0081] Examples of the carbonate precursor to be reacted with the aromatic dihydroxy compound include phosgene, diaryl carbonates such as diphenyl carbonate and ditolyl carbonate, and dialkyl carbonates such as dimethyl carbonate and diethyl carbonate.

[0082] The viscosity average molecular weight of the polycarbonate resin is preferably 15,000 to 30,000, and more preferably 16,000 to 27,000. The viscosity average molecular weight in this specification is a value converted from the solution viscosity measured at 25°C using methylene chloride as a solvent.

[0083] Specific examples of polycarbonate resins include Iupilon H-4000 (manufactured by Mitsubishi Engineering Plastics Corporation, viscosity average molecular weight 16,000), Iupilon S-3000 (manufactured by Mitsubishi Engineering Plastics Corporation, viscosity average molecular weight 23,000), and Iupilon E-2000 (manufactured by Mitsubishi Engineering Plastics Corporation, viscosity average molecular weight 27,000).

[0084] [Acrylic Resin] Acrylic resins can be obtained by polymerizing the (meth)acrylic monomers exemplified below. Examples of the monomers include (meth)acrylic monomers having an alkyl group, (meth)acrylic monomers having a hydroxyl group, (meth)acrylic monomers having a carboxyl group, (meth)acrylic monomers having a glycidyl group, vinyl esters such as vinyl acetate and vinyl propionate, maleic anhydride, vinyl ether, and styrene. In this specification, "(meth)acrylic" means "acrylic and / or methacrylic," and "(meth)acrylate" means "acrylate and / or methacrylate." Specifically, polymethyl methacrylate (PMMA) resin is preferred.

[0085] [Polyester Resin] The polyester resin can be obtained by polymerizing a carboxylic acid component (a compound having a carboxyl group) and a hydroxyl group component (a compound having a hydroxyl group).

[0086] Examples of the carboxylic acid component constituting the polyester resin include benzoic acid, p-tert-butylbenzoic acid, phthalic anhydride, isophthalic acid, terephthalic acid, succinic anhydride, adipic acid, azelaic acid, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, maleic anhydride, fumaric acid, itaconic acid, tetrachlorophthalic anhydride, 1,4-cyclohexanedicarboxylic acid, trimellitic anhydride, methylcyclohexene tricarboxylic anhydride, pyromellitic anhydride, and ε-caprolactone.

[0087] Examples of the hydroxyl group component constituting the polyester resin include diols such as ethylene glycol, propylene glycol, 1,3-butylene glycol, 1,6-hexanediol, diethylene glycol, dipropylene glycol, neopentyl glycol, triethylene glycol, 3-methylpentanediol, and 1,4-cyclohexanedimethanol, as well as polyfunctional alcohols having three or more hydroxyl groups such as trimethylolethane, trimethylolpropane, trishydroxymethylaminomethane, pentaerythritol, and dipentaerythritol.

[0088] [Polyamide Resin] The polyamide resin can be obtained, for example, by reacting the above-mentioned carboxylic acid component with a compound having two or more amino groups, for example, by subjecting the carboxylic acid component to a dehydration condensation reaction with a compound (Am) having two or more amino groups.

[0089] The compound (Am) having two or more amino groups may be any known compound, and examples thereof include aliphatic polyamines such as ethylenediamine, propylenediamine, trimethylenediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, and triethylenetetramine; aliphatic polyamines including alicyclic polyamines such as isophoronediamine and dicyclohexylmethane-4,4'-diamine; aromatic polyamines such as phenylenediamine and xylylenediamine; and diaminoalcohols such as 1,3-diamino-2-propanol, 1,4-diamino-2-butanol, 1-amino-3-(aminomethyl)-3,5,5-trimethylcyclohexane-1-ol, 4-(2-aminoethyl)-4,7,10-triazadecan-2-ol, and 3-(2-hydroxypropyl)-o-xylene-α,α'-diamine.

[0090] The diluent resin (D) may be one of the various resins described above, or a combination of two or more of them. When the diluent resin (D) is a polycarbonate resin, an acrylic resin, a polyester resin, or a polyamide resin, a molded article with high transparency and excellent mechanical strength can be provided. By including a liquid dispersion medium (A) and a surfactant (B) with a specific resin type in the liquid coloring composition, the compatibility between the liquid coloring composition and the diluent resin (D) is enhanced, preventing a decrease in the transparency and mechanical strength of the resulting molded article. In particular, the microscopic supply accuracy of the liquid coloring composition is improved, thereby reducing color unevenness within the resulting molded article and variation in color difference between molded articles. For example, the content of the colorant (C) in the colored resin composition or a molded article molded therefrom can be 0.01 to 10% by mass, 0.03 to 5% by mass, or 0.05 to 3% by mass. Furthermore, due to this effect, color unevenness and variation can be reduced even in highly transparent molded articles, even with a low concentration of the colorant (C). For example, the content of the colorant (C) in the colored resin composition or the molded article thereof can be 0.01 to 1 mass %, 0.03 to 0.5 mass %, or 0.05 to 0.1 mass %. Even when the diluent resin (D) is a polycarbonate resin or an acrylic resin, particularly a polycarbonate resin or a methyl methacrylate resin, a uniform transparent color can be obtained.

[0091] Because the liquid coloring composition contains a liquid medium (A) with a specific resin type and a surfactant (B), it can improve dispersibility, storage stability, and supply accuracy even when it contains a high concentration of colorant (C). By using a liquid coloring composition containing a high concentration of colorant (C), the contents of liquid medium (A) and surfactant (B) in the resulting molded article can be relatively reduced, thereby further increasing the mechanical strength of the molded article. For example, the amount of colorant (C) per 100 parts by weight of liquid medium (A) may be 0.1 to 500 parts by weight, 1 to 300 parts by weight, or 10 to 120 parts by weight. Furthermore, in this case, it is preferable to use an appropriate amount of surfactant (B) relative to the amount of colorant (C). For example, the amount of surfactant (B) per 100 parts by weight of colorant (C) may be 0.01 to 2 parts by weight, 0.05 to 1 part by weight, or 0.1 to 0.5 parts by weight.

[0092] <Method for Producing Colored Resin Composition> The method for producing the colored resin composition is not particularly limited. For example, the colored resin composition and the diluted resin (D), and further various additives and colorants as necessary, are mixed in a Henschel mixer, tumbler, disperser, or the like, and then melt-kneaded in a batch mixer such as a kneader, roll mill, super mixer, high-speed mixer, ball mill, sand mill, attritor, or Banbury mixer, a single-screw extruder, a twin-screw extruder, or a rotor-type twin-screw kneader to produce a pellet-shaped, powder-shaped, granular, or bead-shaped colored resin composition. Because molding is easy, it is preferable to produce a pellet-shaped colored resin composition using a twin-screw extruder. As a method for producing a colored resin composition into pellets, a common method can be used, such as extruding the resin using an extruder and then granulating it using a pelletizer. Furthermore, by pulverizing these pellet-shaped molded bodies, a powder-shaped or granular colored resin composition can be produced. Alternatively, a molded body can be produced directly from a colored resin composition obtained by melt-kneading the colored resin composition and the diluted resin (D) without first preparing a pellet-shaped colored resin composition.

[0093] <<Molded Article>> The molded article is obtained by molding the colored resin composition described above. The molding method for obtaining a molded article by molding the colored resin composition is not particularly limited. By using a liquid colored composition, uniform coloring can be achieved without reducing the mechanical properties of the diluted resin (D), regardless of the molding method, such as injection molding or extrusion molding. Therefore, even in molded articles with low colorant concentrations, such as transparent colors, it is possible to obtain uniformly colored molded articles, and appearance defects such as color unevenness can be suppressed. For example, even in food packaging sheets made of recycled PET resin, where the content of colorant (C) is as low as 5 ppm or less, uniform coloring can be achieved.

[0094] Specifically, for example, (Method 1) a method of melt-kneading a colored resin composition with pellets of diluted resin (D) or the like to form a colored resin composition and obtaining a molded body, (Method 2) a method of melt-kneading a colored resin composition with diluted resin (D) to form a solid masterbatch or the like of the colored resin composition, and further melt-kneading the resulting solid masterbatch together with pellets of diluted resin (D) or the like to obtain a molded body, (Method 3) a method of melt-kneading a colored resin composition with diluted resin (D) to form a compound, and then using the resulting pellets or the like to melt-knead the compound as is to obtain a molded body, and the like can be mentioned.

[0095] Hereinafter, the present disclosure will be described in more detail based on examples, but the present disclosure is not limited to these examples. In the examples, parts and % represent parts by mass and % by mass, respectively, unless otherwise specified. In addition, blank spaces in the tables indicate that no ingredients are blended.

[0096] The materials used in the examples and comparative examples are as follows. <Liquid dispersion medium (A), etc.> A-1: ​​Adekasizer PN-7160 (manufactured by ADEKA Corporation, aliphatic polyester resin, viscosity at 25°C: 150 mPa·s, decomposition onset temperature: 278°C) A-2: Adekasizer PN-5090 (manufactured by ADEKA Corporation, aliphatic polyester resin, viscosity at 25°C: 10,000 mPa·s, decomposition onset temperature: 295°C) A-3: Uniol D-1200 (manufactured by NOF Corporation, polyalkylene glycol resin, viscosity at 25°C: 200 mPa·s, decomposition onset temperature: 276°C) A-4: Adekasizer UL-80 (manufactured by ADEKA Corporation, aromatic polycarboxylic acid ester, viscosity at 25°C: 450 mPa·s, decomposition onset temperature: 310°C) A-5: Adeka Cizer RS-700 (manufactured by ADEKA Corporation, polyether ester resin, viscosity at 25°C: 30 mPa·s, decomposition onset temperature: 300°C) A'-6: BIOCIZER (manufactured by Riken Vitamin Co., Ltd., acetylated monoglyceride, viscosity at 25°C: 30 mPa·s, decomposition onset temperature: 228°C)

[0097] <Surfactants (B), etc.> B-1: Kawastar CR (manufactured by Kawaken Fine Chemicals Co., Ltd., surfactant: hydrogenated castor oil) B-2: MS-6 (manufactured by Nitto Kasei Kogyo Co., Ltd., surfactant: magnesium 12-hydroxystearate) B-3: Sinaka Red SAK-CS-P (manufactured by San-Ace Co., Ltd., surfactant: magnesium stearate) B'-4: DISPERBYK-145 (manufactured by BYK Japan KK, surfactant: phosphate ester compound, acid value: 76 mg KOH / g, amine value: 71 mg KOH / g) B'-5: ARUFON UP-1000 (manufactured by Toagosei Co., Ltd., acrylic resin) B'-6: Umex 1010 (manufactured by Sanyo Chemical Industries, Ltd., maleic anhydride-modified PP resin, acid value: 52 mKOH / g)

[0098] <Colorant (C)> C-1: Macrolex Violet B (manufactured by Bayer, anthraquinone dye, Solvent Violet 13) C-2: Macrolex Red E2G GRAN (manufactured by Lanxess, perinone dye, Solvent Red 179) C-3: Typec CR-60 (manufactured by Ishihara Sangyo Kaisha, titanium oxide, Pigment White 6) C-4: Paliogen Red K3911 (manufactured by BASF, perylene pigment, Pigment Red 178) C-5: #45L (manufactured by Mitsubishi Chemical Corporation, carbon black, Pigment Black 7)

[0099] <Diluted Resins (D)> D-1: Iupilon H-4000 (polycarbonate resin (PC), manufactured by Mitsubishi Engineering Plastics Corporation) D-2: Acrypet VH (acrylic resin, polymethyl methacrylate resin (PMMA), manufactured by Mitsubishi Chemical Corporation) D-3: Polyester MA-2101M (polyester resin (PET), manufactured by Unitika Ltd.) D-4: Amilan CM3001-N (polyamide resin (PA), manufactured by Toray Industries, Inc.)

[0100] Example 1 Production of Liquid Colored Composition (X-1) 100 parts by mass of a liquid dispersion medium (A-1), 1 part by mass of a surfactant (B-1), and 10 parts by mass of a colorant (C-1) were mixed and dispersed in a bead mill to obtain a liquid colored composition (X-1).

[0101] [Examples 2 to 23] <Production of liquid colored compositions (X-2 to 23)> Liquid colored compositions (X-2 to 23) were produced in the same manner as in the production of liquid colored composition (X-1), except that the materials and contents (parts by mass) were changed to those shown in Table 1.

[0102] Comparative Example 1 (Production of Liquid Colored Composition (Y-1)) 100 parts by mass of the liquid dispersion medium (A-1) and 25 parts by mass of the colorant (C-1) were mixed and dispersed using a bead mill, but the viscosity was high and a liquid resin composition (Y-1) could not be obtained.

[0103] [Comparative Examples 2 to 6] Liquid colored compositions (Y-2 to 6) were produced in the same manner as liquid colored composition (X-1), except that the materials and contents (parts by mass) were changed to those shown in Table 1.

[0104] <Evaluation of Liquid Colored Composition> The dispersibility, storage stability, and supply accuracy of the obtained liquid colored composition were evaluated by the following methods. The results are shown in Table 1.

[0105] <Evaluation of Dispersibility> According to JIS K5600-2-5, points where significant spots began to appear (dense points) on the liquid colored composition were observed using a 100 μm gauge, and the evaluation was performed according to the following criteria: [Evaluation criteria] +++: Dense points ≦ 30 μm or less, very good ++: 30 μm < Dense points ≦ 50 μm, good +: 50 μm < Dense points ≦ 70 μm, practically usable NG: 70 μm < Dense points, not practically usable

[0106] <Storage stability evaluation> The storage stability was evaluated by leaving the obtained liquid colored composition to stand for 30 days, visually checking for separation and sedimentation of the colorant (C) in the liquid colored composition, and evaluating the sedimentation stability according to the following criteria. [Evaluation criteria] +++: No separation or sedimentation, very good ++: Some separation and sedimentation, but uniformed upon stirring, good +: Separation and sedimentation, but uniformed upon stirring, usable NG: Separation and sedimentation, not uniform even upon stirring, unusable

[0107] <Supply Accuracy> The obtained liquid colored composition was supplied for 10 minutes at a flow rate of 10 mL / min using a tube color roller pump RP-NBC (manufactured by Sanyo Technos Co., Ltd.) and a high-strength silicone tube with tube dimensions of 1.6 mm x 3.2 mm. The average discharge amount was calculated every 10 seconds, and the discharge amount that was most different from the set value during the 10-minute supply time: Q ｘ and set flow rate: Q ０ (=10 mL / min) ratio Qx / Q ０ From the values, the feeding accuracy was evaluated according to the following criteria: [Evaluation criteria] +++: 0.9≦Qx / Q ０ ≦1.1, very good ++: 0.85≦Qx / Q ０ < 0.9 or 1.1 < Qx / Q ０ ≦1.15, good +: 0.8≦Qx / Q ０ < 0.85 or 1.15 < Qx / Q ０ ≦1.2, practically usable NG: Qx / Q ０ < 0.8 or 1.2 < Qx / Q０ , not practical

[0108]

[0109]

[0110] [Example 24] <Production of colored resin composition> 1 part by mass of the liquid colored composition (X-1) and 100 parts by mass of the diluted resin (D-1) were mixed and kneaded using a twin-screw extruder (manufactured by The Japan Steel Works, Ltd., TEX25αIII) at a kneading temperature of 280°C and a screw rotation speed of 200 rpm to obtain a colored resin composition (Z-1).

[0111] [Examples 25 to 49, Comparative Examples 7 to 11] Colored resin compositions (Z-2 to 30) were produced in the same manner as in Example 24, except that the materials and contents (parts by mass) were changed to those shown in Table 2.

[0112] [Comparative Example 11] 0.1 parts by mass of colorant (C-1) and 100 parts by mass of dilution resin (D-1) were mixed and kneaded at 280°C using a twin-screw extruder (TEX25αIII, manufactured by The Japan Steel Works, Ltd.) to obtain a colored resin composition (Z-31).

[0113] <Evaluation of Colored Resin Composition> The obtained colored resin compositions were evaluated for processability, color unevenness, appearance, and mechanical properties by the following methods. The results are shown in Table 2.

[0114] <Processability> The discharge amount (Q ０ ) and the discharge amount of the colored resin composition when the liquid colored composition is added (Q ｘ ) ratio (Q ｘ / Q ０ ) was calculated and evaluated according to the following criteria: ｘ / Q ０ The higher the value, the less the change in discharge due to the addition of the liquid coloring composition, and the better the processability. [Evaluation Criteria] +++: Q ｘ / Q ０ ≧0.95, very good ++: 0.90≦Q ｘ / Q ０ <0.95, good +: 0.85≦Q ｘ / Q ０ <0.90, practical NG:Qｘ / Q ０ <0.85, not practical

[0115] <Color Unevenness> Using the obtained colored resin composition, 10 plates of 150 mm x 130 mm x 2 mm were produced using an injection molding machine (manufactured by Toshiba Machine Co., Ltd., injection pressure 100 t), and the five plates molded from the sixth to tenth plates were visually evaluated and evaluated according to the following criteria. [Evaluation criteria] +++: No color unevenness on all five plates, very good ++: Color unevenness was observed on one plate, good +: Color unevenness was observed on two plates, usable NG: Color unevenness was observed on three or more plates, not usable

[0116] <Appearance> The surfaces of the five plates used for the color unevenness evaluation were observed, and the number of plates on which bubbles or flash (volatile components generated during molding that appear on the surface of the molded product) were counted and evaluated according to the following criteria: [Evaluation criteria] +++: No bubbles or flash on any of the five plates, very good ++: One plate on which bubbles or flash were visible, good +: Two plates on which bubbles or flash were visible, usable NG: Three or more plates on which bubbles or flash were visible, not usable

[0117] <Shot-to-Shot Variation> Using the obtained colored resin composition, 50 plates of 150 mm x 130 mm x 2 mm were produced using an injection molding machine (manufactured by Toshiba Machine Co., Ltd., injection pressure 100 t), and the color differences (ΔE) of the plates from the 10th to 49th shots were measured using a spectrophotometer 36dG (manufactured by Komica Minolta) with the 50th shot plate as the standard, and evaluated according to the following criteria. [Evaluation criteria] +++: ΔE≦0.3 for all plates, very good ++: 5 or fewer plates with ΔE > 0.3, good +: 10 or fewer plates with ΔE > 0.3, usable NG: 15 or more plates with ΔE > 0.3, not usable

[0118] <Mechanical Properties> Using the obtained colored resin composition, a multipurpose test piece having a length of 80 mm, a width of 10 mm and a height of 4 mm was molded, and the deflection temperature under load of 1.80 MPa was measured in accordance with JIS K7191-2. ０ ) and the colored resin composition (T ｘ ) ratio (T ｘ / T ０ ) was calculated and evaluated according to the following criteria: ｘ / T ０ The higher the value, the less the deterioration of the mechanical properties due to the liquid colored composition, and the better. [Evaluation Criteria] +++: T ｘ / T ０ ≧0.95, very good ++: 0.90≦T ｘ / T ０ <0.95, good +: 0.85≦T ｘ / T ０ <0.90, practical use NG:T ｘ / T ０ <0.85, not practical

[0119]

[0120] As shown in Tables 1 and 2, the liquid coloring composition of the present disclosure has excellent dispersibility, storage stability, and supply accuracy. Furthermore, by using this liquid coloring composition, molded articles with excellent color unevenness and appearance can be obtained without reducing the processability or mechanical properties of the diluted resin (D), and the shot-to-shot variation of the molded articles was also reduced. By using the liquid coloring composition of the present disclosure, it was confirmed that even when coloring polycarbonate resin, acrylic resin, polyester-based resin, and polyamide-based resin, which are generally considered difficult to color uniformly, molded articles with no color unevenness, excellent appearance, and good mechanical properties can be formed. Note that in Comparative Example 1, the viscosity was high and no liquid coloring composition was obtained, and in Comparative Example 3, the dispersibility of the liquid coloring composition was poor and no molded articles could be formed in either case.

[0121] Although the present invention has been described with reference to the above-mentioned several embodiments, the present invention is not limited to these several embodiments. Various modifications can be made to the configuration and details of the present invention within the scope of the present invention.

[0122] The disclosure of this application is related to the subject matter described in Japanese Patent Application No. 2023-205824, filed December 6, 2023, the entire disclosure of which is incorporated herein by reference.

Claims

1. A liquid coloring composition comprising a liquid dispersion medium (A), a surfactant (B), and a colorant (C), wherein the liquid dispersion medium (A) has a viscosity at 25°C of 10,000 mPa·s or less and a decomposition onset temperature of 250°C or more, and is at least one selected from the group consisting of an aliphatic polyester resin, a polyalkylene glycol resin, a polyether ester resin, and an aromatic polycarboxylic acid ester, and the surfactant (B) is at least one selected from the group consisting of a fatty acid ester, a higher fatty acid metal salt, and a fatty acid amide.

2. The liquid coloring composition of claim 1, wherein said fatty acid ester comprises a triglyceride.

3. The liquid colored composition according to claim 1, wherein the mass ratio (B) / (C) of the content of said surfactant (B) to the content of said colorant (C) is 0.01 to 2.

4. The liquid colored composition according to claim 1, comprising 1 to 300 parts by mass of said colorant (C) per 100 parts by mass of said liquid dispersion medium (A).

5. The liquid colored composition according to claim 1, comprising 0.5 to 30 parts by mass of said surfactant (B) per 100 parts by mass of said liquid dispersion medium (A).

6. A colored resin composition comprising the liquid colored composition according to any one of claims 1 to 5 and a diluent resin (D).

7. The colored resin composition according to claim 6, wherein the diluent resin (D) is at least one resin selected from the group consisting of polycarbonate resins, acrylic resins, polyester resins, and polyamide resins.

8. A molded article obtained by molding the colored resin composition according to claim 7.

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