Liquid coloring composition, coloring resin composition, and molded article

Abstract

The problem of the present invention is solved by a liquid coloring composition comprising: a liquid dispersion medium (A) having a viscosity of 10,000 mPa.s or less at 25 DEG C, a decomposition initiation temperature of 250 DEG C or more, and a viscosity of 2,000 mPa.s or less at 25 DEG C, a surfactant (B), and a coloring agent (C), the liquid dispersion medium (A) having a viscosity of 2,000 mPa.s or less at 25 DEG C, and the surfactant (B) being a liquid dispersion medium (A) having a viscosity of 2,000 mPa.s or less at 25 DEG C; the surfactant (A) is at least one selected from the group consisting of aliphatic polyester resin, polyalkylene glycol resin, polyether ester resin and aromatic polycarboxylic acid ester, and the surfactant (B) is at least one selected from the group consisting of fatty acid ester, higher fatty acid metal salt and fatty acid amide.

Description

Technical Field

[0001] This disclosure relates to a liquid coloring composition, a coloring resin composition, and a molded article and a coloring resin composition. Background Technology

[0002] Plastic molded parts are widely used in a wide range of fields, including electrical and electronic equipment parts, automotive parts, medical parts, and food and beverage containers, due to their ease of molding and processing. To enhance the decorative properties of plastic molded parts, various coloring compositions are added during molding processes such as injection molding and extrusion molding.

[0003] Examples of the coloring composition include dry pigments as powdered coloring compositions, solid masterbatches as spherical, granular, or particulate coloring compositions, and liquid masterbatches as liquid coloring compositions.

[0004] Dry pigments are powdered coloring compositions made by mixing colorants such as dyes and pigments with dispersants. Therefore, contamination of the manufacturing line due to scattering can sometimes become a problem. In addition, even if dry pigments are melt-blended with the main resin of the molded body, it is not possible to fully loosen the aggregates of colorants, sometimes resulting in unsightly parts in the molded body.

[0005] Solid masterbatch is a colorant composition made by melt-mixing colorants in resins or the like and then granulating it into granules, and it is widely used. However, when solid masterbatch is used for coloring molded articles with low concentrations of colorants such as translucent colors, it is difficult to produce molded articles with uniform coloring due to the small amount of masterbatch added, and sometimes uneven coloring and appearance defects may occur.

[0006] To achieve uniform coloring of the molded body, the following methods are known: extending the melt mixing time of the solid masterbatch and diluted resin, improving molding conditions such as enhancing melt mixing, reducing the colorant concentration in the solid masterbatch, and increasing the amount of solid masterbatch added during molding.

[0007] However, in the former method, productivity is reduced due to the time-consuming molding cycle. Additionally, issues such as partial resin decomposition and reduced physical properties sometimes arise due to intense mixing. In the latter method, there are concerns about reduced physical properties of the molded article due to increased addition of solid masterbatch. Especially when the diluted resin is polycarbonate or polymethyl methacrylate, its high mechanical properties make plasticization difficult, hindering uniform coloring. Polyester and polyamide resins also experience viscosity reduction during melting due to high processing temperatures; therefore, poor dissolution of the solid masterbatch containing high concentrations of colorant makes uniform coloring difficult.

[0008] To address the aforementioned problem, methods using liquid masterbatches, as described in Patent Documents 1 and 2, are known. Because liquid masterbatches are liquid, they exhibit excellent distributability and can uniformly color plastic molded articles. Patent Document 1 describes a method for adding a liquid masterbatch containing pigments and vegetable oils to a thermoplastic resin, while Patent Document 2 describes a method for adding a liquid masterbatch containing fatty acid esters, solid particles, and surfactants to a specific thermoplastic resin.

[0009] Existing technical documents

[0010] Patent documents

[0011] Patent Document 1: Japanese Patent Application Publication No. 2018-188577

[0012] Patent Document 2: Japanese Patent Application Publication No. 2023-038867

[0013] Patent Document 3: Japanese Patent Application Publication No. 2023-089368

[0014] Patent Document 4: Japanese Patent Application Publication No. 2018-131615 Summary of the Invention

[0015] The problem that the invention aims to solve

[0016] However, in the liquid coloring compositions described in Patent Documents 1 and 2, the colorant is not sufficiently dispersed. Consequently, when molding the molded article, the reduced physical properties of the diluted resin sometimes become a problem.

[0017] Patent Document 3 discloses a liquid masterbatch comprising anatase titanium oxide, a metal passivator, a liquid dispersion medium with specifically specified viscosity and thermal decomposition start temperature, and a dispersant. According to Patent Document 3, even when anatase titanium is included, thickening caused by the deterioration of the resin components can be suppressed. However, this technology does not further improve dispersibility and storage stability in the liquid masterbatch, nor does it improve supply accuracy; the resulting molded articles exhibit uneven color and color differences between molded articles warrant further investigation.

[0018] Patent Document 4 discloses a technique that uses a liquid coloring composition comprising a liquid resin with a specifically specified viscosity, a dispersant having a hindered amine structure, and a colorant to suppress color unevenness and achieve mechanical properties in the obtained molded article. However, the technique disclosed in Patent Document 4 does not address the dispersibility, storage stability, and supply accuracy of the colorant in the liquid coloring composition. Therefore, color unevenness and color differences between molded articles warrant further investigation. Furthermore, these color unevenness and deviations are evident in molded articles possessing transparency and high mechanical strength, issues that have not yet been resolved in the prior art.

[0019] Therefore, the present disclosure aims to provide a liquid coloring composition in which the colorant exhibits excellent dispersibility, good storage stability, and good supply precision, enabling uniform coloring without impairing the appearance of the molded article or the mechanical properties and formability of the diluted resin when incorporated into the resin, and reducing color deviation between molded articles. Furthermore, it provides a molded article exhibiting excellent color uniformity, appearance, mechanical properties, and formability when using the said liquid coloring composition.

[0020] Technical means to solve the problem

[0021] The inventors have conducted diligent research to solve the aforementioned problem, resulting in this invention. This invention includes the following embodiments. However, the embodiments of this invention are not limited to these.

[0022] [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 of less than 10,000 mPa·s at 25°C, a decomposition start temperature of more than 250°C, and is at least one selected from the group consisting of aliphatic polyester resins, polyalkylene glycol resins, polyether ester resins, and aromatic polycarboxylic acid esters, and 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.

[0023] [2] The liquid coloring composition according to [1], wherein the fatty acid ester comprises a triglyceride.

[0024] [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.

[0025] [4] The liquid coloring composition according to any one of [1] to [3], wherein, relative to 100 parts by mass of the liquid dispersion medium (A), it comprises 1 to 300 parts by mass of the colorant (C).

[0026] [5] The liquid coloring composition according to any one of [1] to [4], wherein 0.5 to 30 parts by mass of the surfactant (B) are contained relative to 100 parts by mass of the liquid dispersion medium (A).

[0027] [6] A coloring resin composition comprising a liquid coloring composition according to any one of [1] to [5] and a diluent resin (D).

[0028] [7] The coloring resin composition according to [6], wherein the diluent resin (D) is at least one selected from the group consisting of polycarbonate resin, acrylic resin, polyester resin and polyamide resin.

[0029] [8] A molded body is formed from the coloring resin composition according to [7].

[0030] The effects of the invention

[0031] This disclosure provides a liquid coloring composition in which the colorant exhibits excellent dispersibility, storage stability, and supply precision, enabling uniform coloring without impairing the appearance, mechanical properties, or formability of the molded article when mixed with a diluted resin and molded, and reducing color deviation between molded articles. Furthermore, by using the coloring resin composition of the liquid coloring composition, a molded article with excellent appearance, mechanical properties, and formability can be provided. Detailed Implementation

[0032] The present disclosure will now be described in detail. Furthermore, other embodiments are naturally included within the scope of this disclosure as long as they conform to its spirit. Additionally, the numerical range specifically specified by “~” in this specification includes the range of values ​​before and after the “~” as both lower and upper limits.

[0033] Here, "liquid" refers to a liquid state at 25°C.

[0034] Unless otherwise specified, each ingredient mentioned in this instruction manual may be used independently or in combination with two or more ingredients.

[0035] Liquid coloring compositions

[0036] Liquid coloring compositions can be used as liquid masterbatches to color molded articles.

[0037] The liquid coloring composition can be used by melt-blending with a diluted resin as the main agent when molding plastic molded articles.

[0038] The liquid coloring composition comprises: a liquid dispersion medium (A), a surfactant (B), and a colorant (C), wherein the liquid dispersion medium (A) has a viscosity of less than 10,000 mPa·s at 25°C, a decomposition start temperature of more than 250°C, and is at least one selected from the group consisting of aliphatic polyester resins, polyalkylene glycol resins, polyether ester resins, and aromatic polycarboxylic acid esters, and 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.

[0039] Thus, by using at least one of the group consisting of fatty acid esters, higher fatty acid metal salts, and fatty acid amides as a surfactant (B), and dispersing the colorant (C) in a specific liquid dispersion medium (A), a liquid coloring composition with excellent storage stability and supply precision can be prepared. Furthermore, by mixing the obtained liquid coloring composition with a diluted resin (D) and molding it into a molded article, a liquid coloring composition that can uniformly color the molded article without impairing its appearance, mechanical properties, or formability can be provided. As a result, the obtained molded article has excellent appearance, mechanical properties, and formability.

[0040] <Liquid Dispersion Medium (A)>

[0041] Liquid dispersion media serve as dispersion media to disperse colorants.

[0042] The liquid coloring composition comprises a liquid dispersion medium (A). The liquid dispersion medium (A) has a viscosity of less than 10,000 mPa·s at 25°C, a decomposition start temperature of more than 250°C, and is at least one selected from the group consisting of aliphatic polyester resins, polyalkylene glycol resins, polyether ester resins, and aromatic polycarboxylic acid esters.

[0043] From the viewpoint of the dispersibility of the colorant (C) and the supply accuracy of the liquid coloring composition, the viscosity of the liquid dispersion medium (A) at 25°C is 10,000 mPa·s or less, preferably 10 mPa·s to 7,000 mPa·s, and more preferably 20 mPa·s to 5,000 mPa·s. From the viewpoint of improving supply accuracy and reducing the deviation in color difference between the obtained molded articles, the viscosity of the liquid dispersion medium (A) at 25°C can 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 obtained by measuring according to Japanese Industrial Standards (JIS) K7117-1 using a Type B viscometer.

[0044] Furthermore, from the viewpoint of the formability and appearance of the molded article, the decomposition start temperature of the liquid dispersion medium (A) is 250°C or higher, preferably 260°C or higher, and even more preferably 270°C or higher. There is no particular upper limit to the decomposition start temperature, but from the viewpoint of the viscosity of the liquid dispersion medium (A), it is preferably 320°C or lower. The decomposition start temperature in this specification is the temperature at which a 10% reduction in heating occurs when using a Hitachi High-Tech Science “STA7200” at a heating rate of 10°C / min.

[0045] The freezing point of the liquid dispersion medium (A) is preferably below -5°C, more preferably -50°C to -10°C. The freezing point in this specification is a value obtained by measurement in accordance with JIS K0065.

[0046] The liquid dispersion medium (A) comprises at least one selected from the group consisting of aliphatic polyester resins, polyalkylene glycol resins, polyether ester resins, and aromatic polycarboxylic acid esters. Regarding the compatibility of the liquid dispersion medium (A) 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 polyether ester 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 polyether ester resin. In this combination of liquid dispersion medium (A) and diluent resin (D), by using a surfactant (B), the dispersibility and storage stability of the liquid coloring composition, as well as the supply accuracy, can be further improved. This can prevent a decrease in mechanical strength in the obtained molded articles and suppress the generation of color differences between molded articles. In cases where polycarbonate resin is used as the diluent resin (D), it is generally not easy to obtain compatibility with the liquid coloring composition, but excellent results can be achieved by using surfactant (B).

[0047] [Aliphatic polyester resin]

[0048] Aliphatic polyester resin is a polyester resin obtained by reacting aliphatic polycarboxylic acids with polyols.

[0049] There are no particular restrictions on the aliphatic polycarboxylic acids that constitute aliphatic polyester resins, as long as they have two or more carboxyl groups. Examples include: succinic acid, maleic acid, fumaric acid, glutaric acid, adipic acid, sebacic acid, dodecanedicarboxylic acid, protanetricarboxylic acid, 1,3,6-hexatricarboxylic acid, and 1,3,5-hexatricarboxylic acid. These aliphatic carboxylic acids can be used alone or in combination with two or more.

[0050] There are no particular restrictions on the polyols constituting aliphatic polyester resins, as long as they are alcohols with two or more hydroxyl groups. Examples include: ethylene glycol, 1,2-propanediol, 1,3-propanediol, 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, 1,12-octadecanediol, and other aliphatic diols, as well as polyalkylene glycols such as diethylene glycol and dipropylene glycol. These can be used individually or in combination.

[0051] Specific examples of aliphatic polyester resins include Adekacizer PN-7160 (manufactured by ADEKA, viscosity 150 mPa·s (25°C), freezing point -42°C, adipic acid polyester resin) and Adekacizer PN-5090 (manufactured by ADEKA, viscosity 10,000 mPa·s (25°C), freezing point -10°C, adipic acid polyester resin), etc.

[0052] [Polyalkyldiol resin]

[0053] Polyalkylene glycol resins are generally composed of alkylene glycols having repeating units with 1 to 6 carbon atoms, but various polyalkylene glycols can be used as long as the viscosity at 25°C is below 10,000 mPa·s. From the viewpoint of compatibility and water absorption, polyalkylene glycol resins having repeating units with 2 to 4 carbon atoms are preferred.

[0054] Specific examples of polyalkylene glycol resins include polyethylene glycol with 2 carbon atoms in the repeating unit, polypropylene glycol with 3 carbon atoms in the repeating unit, and polybutanediol with 4 carbon atoms in the repeating unit.

[0055] Specific examples of polyalkylene glycol resins include PEG#300 (manufactured by Nippon Oil Corporation, viscosity 70 mPa·s (25°C), polyethylene glycol) and UNIOL D-1200 (manufactured by Nippon Oil Corporation, viscosity 200 mPa·s (25°C), polypropylene glycol).

[0056] [Polyether ester resin]

[0057] The polyether ester resin is a resin formed by esterifying an aliphatic polycarboxylic acid with an alkyl diol, and the aliphatic polycarboxylic acid and the alkyl diol can be used.

[0058] Specific examples of polyether ester resins include: Adekacizer RS-107 (manufactured by ADEKA, viscosity 20 mPa·s (25℃), freezing point -47℃), Adekacizer RS-700 (manufactured by ADEKA, viscosity 30 mPa·s (25℃), freezing point -53℃), etc.

[0059] [Aromatic polycarboxylic acid esters]

[0060] Aromatic polycarboxylic acid esters are ester compounds obtained by the reaction of aromatic polycarboxylic acids with alcohols. Aromatic polycarboxylic acid esters can be either low-molecular-weight or high-molecular-weight compounds. In one example, an aromatic polycarboxylic acid ester can be an esterification of an aromatic polycarboxylic acid and a monool. In other examples, an aromatic polycarboxylic acid ester can be a condensation polymer of an aromatic polycarboxylic acid and a polyol, or a condensation polymer of an aromatic polycarboxylic acid and a diol.

[0061] There are no particular restrictions on the aromatic polycarboxylic acids that constitute aromatic polycarboxylic acid esters, as long as they have two or more carboxyl groups. Examples include phthalic acid, isophthalic acid, terephthalic acid, trimellitic acid, and pyromellitic acid. These aliphatic carboxylic acids can be used alone or in combination.

[0062] There are no particular restrictions on the alcohols that constitute aromatic polycarboxylic acid esters. Examples include: (1) straight-chain alkyl alcohols such as methanol, ethanol, propanol, butanol, pentanol, hexanol, octanol, nonanol, decanol, undecyl alcohol, dodecanol, tridecanol, tetradecanol, pentadecyl alcohol, hexadecyl alcohol, heptadecanol, octadecyl alcohol, nonadecanol, eicosyl alcohol, octadecyl alcohol, octadecyl alcohol, octadecyl alcohol, triadecyl alcohol, hexadecyl alcohol, octadecyl alcohol, triadecyl alcohol, and triadecyl alcohol; (2) isopropanol, isobutanol, isohexanol, 2-ethylhexanol, isononol, isodecanol, isodecanol, isodecanol, isodecanol, isodecanol, isodecanol, isodecanol, isodecanol, isodecanol, and isodecanol. Branched alkyl alcohols such as isoeicoserotonol, isoeicoserotonol, isoeicoserotonol, isoeicoserotonol, isoeicoserotonol, 2-decyltetradecyl alcohol, isoeicoserotonol, isoeicoserotonol, isoeicoserotonol, isoeicoserotonol, isoeicoserotonol, isoeicoserotonol, isoeicoserotonol, etc.; (3) Straight-chain alkenyl alcohols such as tetradecenol, hexadecenol, heptadecenol, octadecenol, oleyl alcohol, nonadecenol, etc.; (4) Branched alkenyl alcohols such as isoechoserotonol, isoeicoserotonol, etc.; (5) Cyclic alkyl alcohols such as cyclopentanol, cyclohexanol, etc. Furthermore, polyols can also be used. Examples of polyols include: ethylene glycol, 1,2-propanediol, 1,3-propanediol, 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, 1,12-octadecanediol, and other aliphatic diols, as well as polyalkylene glycols such as diethylene glycol and dipropylene glycol. Additionally, examples of polyols include alkylene glycol alkyl ethers, polyalkylene glycol alkyl ethers, or acetate salts thereof, in which at least one hydroxyl group is substituted with an alkyl group. One or more of these can be used. Monobasic aliphatic alcohols are preferred. Monobasic branched aliphatic alkyl alcohols are particularly preferred. In addition, the number of carbon atoms in alcohols can be 3–22, 4–18, or 6–12, and the number of carbon atoms in monobranched aliphatic alkyl alcohols can be within these ranges.

[0063] Specific examples of aromatic polycarboxylic acid esters include Adekacizer UL-80 (manufactured by ADEKA, viscosity 450 mPa·s (25°C), 2-ethylhexyl pyromellitic acid) and Adekacizer UL-100 (manufactured by ADEKA, viscosity 176 mPa·s (25°C), alkyl pyromellitic acid).

[0064] The liquid dispersion medium (A) can be used alone with one of the various resins, or in combination with two or more. Since the liquid dispersion medium (A) functions as a dispersion medium for the colorant (C), the liquid coloring composition may also exclude 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 substantially exclude water relative to the total mass of the liquid coloring composition, for example, less than 1% by mass.

[0065] <Surfactant (B)>

[0066] Surfactant (B) is at least one selected from the group consisting of fatty acid esters, higher fatty acid metal salts, and fatty acid amides, preferably fatty acid esters or higher fatty acid metal salts. 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 feeding precision of the liquid coloring composition can be improved. By improving the feeding precision of the liquid coloring composition, color difference deviations between molded articles can be reduced in the obtained molded articles. This effect can be further confirmed for the phenomenon that color difference deviations occur between the obtained molded articles even when no significant difference in feeding precision is observed in the liquid coloring composition. Here, surfactant refers to a compound having both hydrophilic and lipophilic groups in its molecule, and having the effect of reducing interfacial tension through strong adsorption of immiscible substances to the interface and molecular orientation.

[0067] Surfactant (B) can also function as a dispersant in liquid coloring compositions. Here, a dispersant is a compound that interacts with the colorant and disperses the colorant uniformly in the liquid dispersion medium.

[0068] By using a liquid dispersion medium (A) and a surfactant (B), a liquid coloring composition can be provided, wherein the colorant (C) exhibits excellent dispersibility, good storage stability, and good supply precision, enabling uniform coloring without impairing the appearance, mechanical properties, or formability of the molded article when incorporated into the diluted resin (D). By including at least one of fatty acid esters, higher fatty acid metal salts, and fatty acid amides in the surfactant (B), the supply precision can be further improved, reducing color difference deviations between molded articles.

[0069] Because of the strong interaction between the surfactant (B) and the colorant (C), the dispersibility of the colorant (C) can be further improved. Therefore, even when the colorant (C) is at least one of inorganic pigments and dyes, the dispersibility of the liquid coloring composition is not reduced, thus improving storage stability and supply accuracy. As a result, it is possible to provide molded articles with suppressed strength reduction, uniform coloring, and excellent appearance. Furthermore, the deviation in color difference between the obtained molded articles can be reduced.

[0070] Regarding color differences between molded parts, when molding parts using a coloring resin composition containing a liquid coloring composition and a diluted resin (D), color differences sometimes occur between molded parts formed continuously by injection molding, extrusion molding, etc. In addition, in injection molding, one part is formed per shot, but color differences sometimes occur between parts.

[0071] [Fatty acid esters]

[0072] Fatty acid esters have a structure formed by ester bonding of one or more fatty acids with an alcohol. Examples of alcohols include monohydric alcohols and polyhydric alcohols. Preferably, the number of oxygen atoms is 8 or less. Monohydric alcohols are preferably higher alcohols with 6 or more carbon atoms, more preferably higher alcohols with 10 or more carbon atoms. Examples include myristol, 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 glycerol, diglycerol, triglycerol, trimethylolethane, trimethylolpropane, pentaerythritol, dipentaerythritol, mannitol, and sorbitol. Glycerol, propylene glycol, pentaerythritol, and dipentaerythritol are preferred, more preferably glycerol and dipentaerythritol.

[0073] The fatty acids constituting fatty acid esters are monocarboxylic acids having a carboxyl group on their hydrocarbon chain. Examples include: saturated fatty acids such as hexanoic acid, octanoic acid, capric acid, undecanoic acid, lauric acid, tridecanoic acid, myristic acid, palmitic acid, stearic acid, behenic acid, lignoceric acid, cerotic acid, lignic acid, and melissic acid; unsaturated fatty acids such as oleic acid, transoleic acid, linoleic acid, linolenic acid, arachidonic acid, pracidic acid, erucic acid, and ricinoleic acid; hydroxy fatty acids such as 12-hydroxystearic acid; and aliphatic dicarboxylic acids such as adipic acid. Fatty acids with 6 or more carbon atoms are preferred, and fatty acids with 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, and stearic acid and 12-hydroxystearic acid are particularly preferred. Triglycerides are particularly preferred as fatty acid esters.

[0074] Triglycerides are esters of fatty acids and glycerol. The carbon content of the fatty acids in triglycerides is preferably 10-22, more preferably 12-20, and even more preferably 14-18. The three fatty acids constituting the triglyceride may be the same or may be partially or completely different. Examples of fatty acids that can be triglycerides include long-chain fatty acids such as stearic acid, lauric acid, ricinoleic acid, caprylic acid, linoleic acid, and palmitic acid, and their derivatives, with fatty acids containing hydroxyl groups being particularly preferred. Examples of triglycerides include, for example, castor oil, coconut oil, olive oil, and their hydrogenated derivatives, with hydrogenated castor oil being preferred.

[0075] Hydrogenated castor oil is a hardened castor oil produced by adding hydrogen to the unsaturated bonds of castor oil. It is a triglyceride ester of 12-hydroxystearic acid. Specific examples of hydrogenated castor oil include Kawastar CR (manufactured by Kawaken Fine Chemicals).

[0076] 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 fatty acid in the higher fatty acid metal salt preferably has 10 to 22 carbon atoms, more preferably 12 to 20, and even more preferably 14 to 18. Examples of fatty acids that can be used as higher fatty acid metal salts include long-chain fatty acids such as stearic acid, lauric acid, ricinoleic acid, caprylic acid, linoleic acid, and palmitic acid, and their derivatives. To improve the adsorption of colorant (C), the fatty acid in the higher fatty acid metal salt may also have substituents such as hydroxyl groups. Examples of metals include lithium, magnesium, calcium, barium, and zinc, among which alkaline earth metals are preferred, and magnesium is more preferred. Because of its good adsorption of colorant (C), the metal soap is preferably magnesium stearate and its derivatives, more preferably magnesium 12-hydroxystearate. Specific examples of higher fatty acid metal salts include SHINACA LEAD SAK-MS-P (manufactured by SUN ACE, magnesium stearate) and MS-6 (manufactured by Nitto Kasei Corporation, magnesium 12-hydroxystearate).

[0077] [Fatty acid amide]

[0078] Fatty acid amides have a structure formed by the amide bond of one or more fatty acids and amines.

[0079] Examples of amines include monoamines and polyamines. Monoamines are preferably ammonia or amines with 10 or more carbon atoms. Examples include oleylamine and stearylamine. Polyamines are preferably diamines with 3 or fewer nitrogen atoms. Among them, diamines with 6 or fewer carbon atoms, such as ethylenediamine and hexamethylenediamine, are preferred.

[0080] Examples of fatty acids constituting fatty acid amides include the aforementioned fatty acids. Long-chain fatty acids with 13 or more carbon atoms are preferred, and stearic acid, 12-hydroxystearic acid, and erucic acid are more preferred.

[0081] Examples of fatty acid amides include: aliphatic monocarboxylic acid amides such as lauryl amide, palmitamide, oleamide, stearamide, erucamide, benzyl amide, ricinoleamide, and hydroxystearamide; N-substituted aliphatic monocarboxylic acid amides such as N-oleyl oleamide, N-oleyl stearamide, and N-stearyl oleamide; aliphatic dicarboxylic acid amides such as methylene bis-stearamide and ethylene bis-stearamide; N,N'-ethylene-bis-oleamide; N,N'-ethylene bis-stearamide; and N,N'-methylene bis-stearamide. Stearamide, erucamide, and N,N'-ethylene bis-stearamide are preferred.

[0082] From the viewpoint of the dispersibility of the colorant (C) and the mechanical properties based on its compatibility with the diluted resin (D), the acid value of the surfactant (B) is preferably 180 mgKOH / g or less, and more preferably 140 mgKOH / g or less.

[0083] In terms of the dispersibility of the colorant (C) and the mechanical properties based on its compatibility with the diluted resin (D), such as the ability to suppress the decrease in load flexural temperature, the amine value of the surfactant (B) is preferably 180 mgKOH / g or less, and more preferably 140 mgKOH / g or less.

[0084] Regarding the content of surfactant (B), from the viewpoint of the mechanical properties of the compatibility between colorant (C) and diluent resin (D), such as the ability to suppress the decrease in load flexural temperature, it 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 liquid dispersion medium (A). Furthermore, 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 surfactant (B) contains two or more of fatty acid esters, higher fatty acid metal salts, and fatty acid amides, their combined amount is preferably within the aforementioned range.

[0085] In addition to containing fatty acid esters, higher fatty acid metal salts, fatty acid amides, or combinations thereof, liquid coloring compositions may also contain other surfactants. Furthermore, liquid coloring compositions may also contain dispersants.

[0086] As a dispersant, a dispersant-type acrylic resin can be used. Acrylic resin is a polymer containing a constituent unit derived from a (meth)acrylic acid monomer, and examples include (meth)acrylic acid resins and styrene-acrylic acid resins. Preferably, the acrylic resin has at least one polymer block containing a constituent unit derived from a (meth)acrylic acid monomer.

[0087] From the viewpoint of solubility in the liquid dispersion medium (A) and the physical properties of the diluted resin (D), the weight-average molecular weight of the acrylic resin is preferably 500 to 20,000, and more preferably 1,000 to 15,000. In this specification, the weight-average molecular weight is a value obtained by gel permeation chromatography (GPC) (the value obtained using polystyrene as a standard and tetrahydrofuran as the eluent).

[0088] Examples of (meth)acrylic acid monomers constituting acrylic resins include: (meth)acrylic acid, methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, pentyl (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, and (meth)acrylic acid. Butoxyethyl ester, phenoxyethyl ester (meth)acrylate, nonylphenoxyethyl ester (meth)acrylate, glycidyl ester (meth)acrylate, dimethylaminoethyl ester (meth)acrylate, diethylaminoethyl ester (meth)acrylate, isobornyl ester (meth)acrylate, dicyclopentyl ester (meth)acrylate, dicyclopentenyl ester (meth)acrylate, dicyclopentenoxyethyl ester (meth)acrylate, etc. (meth)acrylates, mono(meth)acrylates having (poly)ethylene glycol, (poly)propylene glycol, (poly)butanediol, etc. (meth)acrylates or their esters, etc.

[0089] Styrene-acrylic resin is a copolymer of styrene monomer and (meth)acrylic acid monomer. Examples of styrene monomers include styrene and α-methylstyrene. Styrene-acrylic resin is preferably a polymer having styrene polymer blocks and (meth)acrylic acid polymer blocks.

[0090] Acrylic resins can have functional groups, such as hydroxyl, carboxyl, epoxy, alkyl, alkoxysilyl, etc.

[0091] Specific examples of acrylic resins include: ARUFON UP-1000 (manufactured by Dong-A Synthetic Co., Ltd., with a weight average molecular weight of 3,000, an acrylic resin), ARUFON UP-2170 (manufactured by Dong-A Synthetic Co., Ltd., with a weight average molecular weight of 14,000, a styrene-acrylic resin), etc.

[0092] 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, tri(β-chloroethyl) phosphate, tri(β-chloropropyl) phosphate, tri(dichloropropyl) phosphate, etc., or phenyl phosphates such as trimethylbenzyl phosphate, tri(isopropylphenyl) phosphate, tolyl diphenyl phosphate, octyl diphenyl phosphate, etc., alkyl polyoxyethylene phosphates such as tributoxyethyl phosphate, alkylphenol polyoxyethylene phosphates, and their neutralizing salts such as sodium, potassium, ammonia, and amines. Furthermore, these phosphate ester compounds may also have acid values ​​or amine values. These phosphate ester compounds can be used alone or in combination of two or more. From the viewpoint of the dispersibility and storage stability of the colorant (C), phosphate ester compounds are preferably alkyl polyoxyethylene phosphates or alkylphenol polyoxyethylene phosphates having acid values ​​or amine values.

[0093] Specific examples of phosphate ester compounds include: ADEKA REASOAP PP-70 (manufactured by ADEKA, phosphate ester), DISPER BYK-102 (manufactured by BYK-Chemie, acid value 101 mgKOH / g), DISPER BYK-145 (manufactured by BYK-Chemie, acid value 76 mgKOH / g, amine value 71 mgKOH / g), etc.

[0094] When other surfactants and dispersants are used in addition to fatty acid esters, higher fatty acid metal salts, fatty acid amides, or combinations thereof, the total amount of other surfactants and dispersants relative to 100 parts by weight of surfactant (B) can be 0 to 50 parts by weight, 0 to 20 parts by weight, or 0 to 10 parts by weight. Even without further use of other surfactants and dispersants, the effects of the liquid coloring composition and the obtained molded article can be expected by using fatty acid esters, higher fatty acid metal salts, fatty acid amides, or combinations thereof.

[0095] <Colorant (C)>

[0096] There are no particular restrictions on the colorant (C), and commonly used dyes, pigments, etc. can be used.

[0097] Examples of dyes include: methylene dyes, violet ketone dyes, anthraquinone dyes, etc.

[0098] Examples of suitable pigments include inorganic pigments such as titanium dioxide, chrome titanium yellow, iron oxide red, ultramarine, and carbon black; and organic pigments such as azo pigments, quinacridone pigments, perylene pigments, diketopyrrolopyrrole pigments, and phthalocyanine pigments. Regarding titanium dioxide, compared to anatase, rutile has lower reactivity and is less likely to induce resin degradation; therefore, rutile is preferred.

[0099] From the viewpoint of heat resistance, pigments are preferred; from the viewpoint of transparency, dyes are preferred.

[0100] Examples of methylene-based dyes include, for example, Solvent Yellow 93 and 179 (CI). Examples of violet-based dyes include Solvent Red 135 and 179 (CI). Examples of anthraquinone-based dyes include Solvent Red 52 and 151, Solvent Violet 13 and 36, and Solvent Blue 97 (CI). Furthermore, "CI" refers to the Colour Index.

[0101] Specific examples of the methylene 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 violet ketone 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 dyes mentioned above include: Sumiplast Red HL5B (manufactured by SumikaChemtex, Solvent Red 52), Sumiplast Red HL2B (manufactured by SumikaChemtex, Solvent Red 151), Macrolex Violet B-FG (manufactured by Lanxess, Solvent Violet 13), Macrolex Violet 3R-FG (manufactured by Lanxess, Solvent Violet 36), and Macrolex Blue RR GRAN (manufactured by Lanxess, Solvent Blue 97), etc.

[0102] Examples of inorganic pigments include: CI pigment white 6, pigment brown 24, pigment red 101, pigment blue 29, pigment black 7, etc.

[0103] Examples of organic pigments include: Azo pigments include: CI Pigment Yellow 180, 181; Pigment Orange 64; Pigment Red 144, 166, 214, 221, etc. Quinacridone pigments include: CI Pigment Violet 19; Pigment Red 122, etc. Perylene pigments include: CI Pigment Red 149, 178, etc. Diketopyrrolopyrrole pigments include: CI Pigment Red 254, etc. Phthalocyanine pigments include: CI Pigment Blue 15:1, 15:3; Pigment Green 7, 36, etc.

[0104] These colorants (C) can be used alone or in combination with more than one.

[0105] Specific examples of the inorganic pigments mentioned above include: Tipaque PF-740 (manufactured by Ishihara Sangyo Co., Ltd., rutile titanium dioxide, pigment white 6), Tomatec 42-118A (manufactured by Tokan Materials & Technology Co., Ltd., pigment brown 24), Toda Color 120ED (manufactured by Toda Kogyo Co., Ltd., pigment red 101), and Ultramarine No. 1500 (manufactured by Daiichi Chemical Co., Ltd., pigment blue 29), etc.

[0106] Specific examples of the organic pigments mentioned above include the following. Specific examples of the azo pigments mentioned above include: PV Fast Yellow HG (manufactured by Clariant, Pigment Yellow 180), PV Fast Yellow H3R (manufactured by Clariant, Pigment Yellow 181), Cromophthalal Orange K2960 (manufactured by BASF, Pigment Orange 64), Cromophthalal Red K3890FP (manufactured by BASF, Pigment Red 144), Cromophthalal Scarlet K3540 (manufactured by BASF, Pigment Red 166), Cromophthalal Red K3900 (manufactured by BASF, Pigment Red 214), Cromophthalal Red K4035 (manufactured by BASF, Pigment Red 221), etc. Specific examples of the quinacridone pigments include: PV Fast Red E4G (manufactured by Clariant, Pigment Violet 19), PV Fast Pink E-01 (manufactured by Clariant, Pigment Red 122), etc. Specific examples of the perylene pigments include: Paliogen Red K3580 (manufactured by BASF, Pigment Red 149), Paliogen Red K3911 (manufactured by BASF, Pigment Red 178), etc. Specific examples of the diketopyrrolopyrrole pigments include: Irgazin Red K3840 (manufactured by BASF, Pigment Red 254), etc. Specific examples of the phthalocyanine pigments mentioned above include: Lionol Blue CB7801 (manufactured by TOYOCOLOR, pigment blue 15:1), Lionol Blue FG7351 (manufactured by TOYOCOLOR, pigment blue 15:3), Lionol Green Y-102 (manufactured by TOYOCOLOR, pigment green 7), and Lionol Green 6Y-501 (manufactured by TOYOCOLOR, pigment green 36), etc.

[0107] From the viewpoint of the dispersibility of the colorant (C) and the supply precision of the liquid coloring composition, the content of the colorant (C) in the liquid coloring composition is preferably 1 to 300 parts by mass relative to 100 parts by mass of the liquid dispersion medium (A), and more preferably 5 to 250 parts by mass.

[0108] When the colorant (C) is an inorganic pigment, the dispersibility can be further improved by the surfactant (B) comprising at least one of fatty acid esters, higher fatty acid metal salts, and fatty acid amides, wherein hydrogenated castor oil is preferred.

[0109] When the colorant (C) is a dye, the dispersibility can be further improved by the surfactant (B) comprising at least one of fatty acid esters, higher fatty acid metal salts, and fatty acid amides, wherein hydrogenated castor oil is preferred.

[0110] When the colorant (C) is an organic pigment, the dispersibility can be further improved by the surfactant (B) containing at least one of fatty acid esters, higher fatty acid metal salts, and fatty acid amides. Therefore, from the viewpoint of dispersibility, it is preferable to use acrylic resin as a dispersant.

[0111] By using these surfactants (B), the adsorption of colorant (C) is further improved, and the sedimentation stability of colorant (C) becomes better, thus balancing the dispersibility and storage stability of the liquid coloring composition.

[0112] From the viewpoint of the dispersibility and storage stability of the colorant (C), the content ratio of surfactant (B) to colorant (C) (B) / (C) is preferably 0.01 to 2, more preferably 0.05 to 1, and even more preferably 0.1 to 0.5.

[0113] From the viewpoint of dispersibility and storage stability, the total amount of 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.

[0114] <Other Additives>

[0115] The liquid coloring composition may contain any other polymers, antistatic agents, defoamers, matting agents, fluorescent whitening agents, stabilizers, antioxidants, viscosity modifiers, and other additives.

[0116] Additionally, liquid dispersion media other than liquid dispersion media (A), surfactants other than surfactants (B), and dispersants may be included to the extent that the effects of this disclosure are not impaired.

[0117] <Method for manufacturing liquid coloring composition>

[0118] The method for manufacturing the liquid coloring composition is not particularly limited. For example, the liquid coloring composition can be obtained by adding a liquid dispersion medium (A), a surfactant (B), a colorant (C), and other additives as needed, mixing them using a Henschel mixer, a tumbler, a disperser, etc., and dispersing them using a Silverson mixer (manufactured by Silverson Corporation). In addition to the aforementioned apparatus, any device such as a kneader, roller mill, ball mill, or sand mill can be used for dispersion. For the reasons of ease of molding and excellent dispersibility, a ball mill, a Silverson mixer, or a roller mill is preferred.

[0119] Coloring Resin Compositions

[0120] The coloring resin composition comprises the liquid coloring composition described herein and a diluted resin (D) for molding into a molded article.

[0121] Diluent resin (D) is the main resin used for coloring the molded body through a liquid coloring composition, becoming the main component of the molded body. Thermoplastic resins are primarily used, and the appropriate resin is selected based on the intended use of the molded body.

[0122] The content of the liquid coloring composition relative to 100 parts by weight of the diluted resin (D) is preferably 0.001 parts by weight or more, more preferably 0.005 parts by weight or more. Furthermore, it is preferably 10 parts by weight or less, more preferably 5 parts by weight or less, and even more preferably 1 part by weight or less, particularly preferably 0.5 parts by weight or less.

[0123] This results in superior processability and mechanical properties. Furthermore, it allows for the production of molded articles with excellent appearance, free from color inconsistencies or colorant agglomerates.

[0124] There are no particular limitations on the resins that can be colored by liquid coloring compositions. Examples of diluent resins (D) include: polycarbonate resins, acrylic resins, polyester resins, polyamide resins, polyvinyl chloride resins, polystyrene resins, cycloolefin copolymers (COC), etc.

[0125] The liquid coloring composition of the invention can also be suitably used for coloring polycarbonate resins, acrylic resins, polyester resins, and polyamide resins that are generally difficult to color uniformly. The acrylic resin is preferably polymethyl methacrylate resin.

[0126] [Polycarbonate resin]

[0127] Polycarbonate resins are readily manufactured by reacting aromatic dihydroxy compounds with carbonate precursors such as phosgene or diesters. The reaction can be a known reaction; for example, when using phosgene, it can be obtained via an interfacial process, and when using diesters, it can be obtained via transesterification, where the reaction occurs in a molten state.

[0128] Examples of such aromatic dihydroxy compounds include: 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-tert-butylphenyl)propane, 2,2-bis(4-hydroxy-3-bromophenyl)propane, 2,2-bis(4-hydroxy-3,5-dibromophenyl)propane, 2,2-bis(4-hydroxy-3,5-dichlorophenyl)propane, and other bis(hydroxyaryl)alkanes. Classes include: 1,1-bis(4-hydroxyphenyl)cyclopentane, 1,1-bis(4-hydroxyphenyl)cyclohexane, and other bis(hydroxyaryl)cycloalkanes; 4,4'-dihydroxydiphenyl ether, 4,4'-dihydroxy-3,3'-dimethyldiphenyl ether, and other dihydroxydiaryl ethers; 4,4'-dihydroxydiphenyl sulfide, 4,4'-dihydroxy-3,3'-dimethyldiphenyl sulfide, and other dihydroxydiaryl sulfoxides; 4,4'-dihydroxydiphenyl sulfoxide, 4,4'-dihydroxy-3,3'-dimethyldiphenyl sulfoxide, and other dihydroxydiaryl sulfoxides; 4,4'-dihydroxydiphenyl sulfone, 4,4'-dihydroxy-3,3'-dimethyldiphenyl sulfone, and other dihydroxydiaryl sulfones, etc. These can be used alone or in combination of two or more. In addition to these, piperazine, dipiperidinylhydroquinone, resorcinol, and 4,4'-dihydroxydiphenyl compounds can also be mixed and used. Furthermore, branched aromatic polycarbonate resins containing polyfunctional compounds such as phloroglucinol can also be used.

[0129] Examples of carbonate precursors that react with the aromatic dihydroxy compounds include: phosgene, diphenyl carbonate, dimethyl carbonate, and other diaryl carbonate esters; dimethyl carbonate, diethyl carbonate, and other dialkyl carbonate esters.

[0130] The viscosity-average molecular weight of the polycarbonate resin is preferably 15,000 to 30,000, more preferably 16,000 to 27,000.

[0131] Furthermore, the viscosity-average molecular weight in this specification is a value calculated using dichloromethane as the solvent and based on the solution viscosity measured at 25°C.

[0132] Specific examples of polycarbonate resins include: Iupilon H-4000 (manufactured by Mitsubishi Engineering Plastics, with an average molecular weight of 16,000), Iupilon S-3000 (manufactured by Mitsubishi Engineering Plastics, with an average molecular weight of 23,000), and Iupilon E-2000 (manufactured by Mitsubishi Engineering Plastics, with an average molecular weight of 27,000).

[0133] [Acrylic resin]

[0134] Acrylic resins can be obtained by polymerizing (meth)acrylic monomers exemplified below. Examples of monomers include: (meth)acrylic monomers having alkyl groups, (meth)acrylic monomers having hydroxyl groups, (meth)acrylic monomers having carboxyl groups, (meth)acrylic monomers having glycidyl groups, vinyl esters such as vinyl acetate or vinyl propionate, maleic anhydride, vinyl ethers, styrene, etc. Furthermore, in this specification, "(meth)acrylic acid" refers to "acrylic acid and / or methacrylic acid," and "(meth)acrylate" refers to "acrylate and / or methacrylate." Specifically, polymethyl methacrylate (PMMA) resin is preferred.

[0135] [Polyester resin]

[0136] Polyester resins can be obtained by polymerizing a carboxylic acid component (a compound with a carboxyl group) with a hydroxyl component (a compound with a hydroxyl group).

[0137] Examples of carboxylic acid components that constitute polyester resins 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, methylcyclohexenetricarboxylic anhydride, pyromellitic anhydride, ε-caprolactone, etc.

[0138] Examples of hydroxyl components that constitute polyester resins include: ethylene glycol, propylene glycol, 1,3-butanediol, 1,6-hexanediol, diethylene glycol, dipropylene glycol, neopentyl glycol, triethylene glycol, 3-methylpentanediol, 1,4-cyclohexanediol, and other diols, as well as polyfunctional alcohols with three or more hydroxyl groups such as trimethylolethane, trimethylolpropane, trihydroxymethylaminomethane, pentaerythritol, and dipentaerythritol.

[0139] [Polyamide resin]

[0140] Polyamide resins can be obtained, for example, by reacting the carboxylic acid component with a compound having two or more amino groups. For instance, the carboxylic acid component can be obtained by undergoing a dehydration condensation reaction with a compound (Am) having two or more amino groups.

[0141] As compounds having two or more amino groups (Am), known compounds can be used, such as: aliphatic polyamines such as ethylenediamine, propylenediamine, trimethylenediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, and triethylenetetramine; aliphatic polyamines containing alicyclic polyamines such as isophorone diamine and dicyclohexylmethane-4,4'-diamine; aromatic polyamines such as phenylenediamine and xylenediamine; and diamino alcohols 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-triazadecane-2-ol, and 3-(2-hydroxypropyl)-o-xylene-α,α'-diamine.

[0142] The diluent resin (D) can be used alone or in combination with two or more of the various resins described above. When the diluent resin (D) is a polycarbonate resin, acrylic resin, polyester resin, or 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) of a specifically designated resin type in the liquid coloring composition, the compatibility between the liquid coloring composition and the diluent resin (D) is improved, preventing a decrease in the transparency and mechanical strength of the obtained molded article. In particular, since the microscopic supply precision of the liquid coloring composition is improved, color inhomogeneity within the molded article and color difference deviation between molded articles can be reduced. For example, the content of the colorant (C) can be set to 0.01% to 10% by mass, 0.03% to 5% by mass, or 0.05% to 3% by mass relative to the coloring resin composition or the molded article obtained therefrom. Furthermore, through this effect, even with a low concentration of colorant (C), color inhomogeneity and deviation can be reduced in molded articles with high transparency. For example, the content of colorant (C) can be set to 0.01% to 1% by mass, 0.03% to 0.5% by mass, or 0.05% to 0.1% by mass relative to the coloring resin composition or the molded body obtained therefrom. Even when the diluted resin (D) is polycarbonate resin and acrylic resin, especially polycarbonate resin and methyl methacrylate resin, a uniform transparent coloring can be obtained.

[0143] Because the liquid coloring composition contains a liquid medium (A) of a specifically designated resin type and a surfactant (B), even with a high concentration of colorant (C), dispersibility, storage stability, and supply accuracy can be improved. By using a liquid coloring composition containing a high concentration of colorant (C), the content of liquid medium (A) and surfactant (B) in the obtained molded article can be relatively reduced, further improving the mechanical strength of the molded article. For example, relative to 100 parts by weight of liquid medium (A), the colorant (C) can be 0.1 parts by weight to 500 parts by weight, 1 part by weight to 300 parts by weight, or 10 parts by weight to 120 parts by weight. Furthermore, in this case, a suitable amount of surfactant (B) can be used relative to the colorant (C). For example, relative to 100 parts by weight of colorant (C), the surfactant (B) can be 0.01 parts by weight to 2 parts by weight, 0.05 parts by weight to 1 part by weight, or 0.1 parts by weight to 0.5 parts by weight.

[0144] <Method for manufacturing coloring resin composition>

[0145] There are no particular limitations on the manufacturing method of the coloring resin composition. For example, the coloring resin composition can be added to a diluted resin (D), and various additives or colorants as needed. After mixing using a Henschel mixer, drum mill, disperser, etc., the mixture can be melt-kneaded using a kneader, roller mill, super mixer, high-speed mixer, ball mill, sand mill, grinder, batch mixer such as a Banbury mixer, single-spindle extruder, twin-spindle extruder, rotor-type twin-spindle mixer, etc., to produce a spherical, powdery, granular, or bead-shaped coloring resin composition. Since molding and processing are easy, it is preferable to use a twin-spindle extruder to produce a granular coloring resin composition.

[0146] As a manufacturing method for forming the coloring resin composition into granules, a general method can be used, which involves extrusion using an extruder followed by granulation using a granulator. Alternatively, by crushing these granular shapes, the coloring resin composition can be produced in powder or granular form.

[0147] Alternatively, the molded article can be directly formed from a coloring resin composition obtained by melt-blending a coloring resin composition with a diluted resin (D) without using a granular coloring resin composition.

[0148] "Formed Body"

[0149] The molded article is formed from the coloring resin composition described above. There are no particular limitations on the molding method used to obtain the molded article by molding the coloring resin composition. By using the liquid coloring 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.

[0150] Therefore, even molded articles with low concentrations of colorants such as transparent colorants can be made into molded articles with uniform coloring, and appearance defects such as uneven coloring can be suppressed.

[0151] For example, food packaging sheets using recycled polyethylene terephthalate (PET) resin can be uniformly colored even with a low addition amount of colorant (C) of less than 5 ppm.

[0152] Specifically, examples include: (Method 1) a method of obtaining a molded article by melt-mixing a coloring resin composition with pellets of diluent resin (D) to form a coloring resin composition; (Method 2) a method of obtaining a molded article by using a coloring resin composition obtained by melt-mixing a coloring resin composition with diluent resin (D) to form a solid masterbatch, and then melt-mixing it with pellets of diluent resin (D); (Method 3) a method of obtaining a molded article by melt-mixing a coloring resin composition with diluent resin (D) to form a composite, and then directly melt-mixing it with a substance that has been temporarily formed into pellets.

[0153] Example

[0154] The present disclosure will now be described in more detail based on embodiments, but the present disclosure is not limited to the embodiments. In the embodiments, parts and % represent parts by mass and percentage by mass, respectively, unless otherwise specified. In addition, empty columns in the table indicate unmixed portions.

[0155] The following shows the materials used in the embodiments and comparative examples.

[0156] <Liquid dispersion media (A) etc.>

[0157] A-1: Adekacizer PN-7160 (manufactured by ADEKA, aliphatic polyester resin, viscosity at 25°C: 150 mPa·s, decomposition start temperature: 278°C)

[0158] A-2: Adekacizer PN-5090 (manufactured by ADEKA, aliphatic polyester resin, viscosity at 25°C: 10,000 mPa·s, decomposition start temperature: 295°C)

[0159] A-3: UNIOL D-1200 (manufactured by Nippon Oil Company, polyalkylene glycol resin, viscosity at 25°C: 200 mPa·s, decomposition start temperature: 276°C)

[0160] A-4: Adekacizer UL-80 (manufactured by ADEKA, aromatic polycarboxylic acid ester, viscosity at 25°C: 450 mPa·s, decomposition start temperature: 310°C)

[0161] A-5: Adekacizer RS-700 (manufactured by ADEKA, polyether ester resin, viscosity at 25°C: 30 mPa·s, decomposition start temperature: 300°C)

[0162] A'-6: Biocizer (manufactured by Riken Vitamin Co., Ltd., acetylated monoglyceride, viscosity at 25°C: 30 mPa·s, decomposition onset temperature: 228°C)

[0163] <Surfactant (B) etc.>

[0164] B-1: Kawastar CR (manufactured by Kawaken Fine Chemicals, surfactant: hydrogenated castor oil)

[0165] B-2: MS-6 (manufactured by Nitto Kasei Corporation, surfactant: magnesium 12-hydroxystearate)

[0166] B-3: SHINACA LEAD SAK-CS-P (manufactured by SUN ACE, surfactant: magnesium stearate)

[0167] B'-4: DISPER BYK-145 (manufactured by BYK-Chemie Japan, surfactant: phosphate ester compound, acid value: 76 mgKOH / g, amine value: 71 mgKOH / g)

[0168] B'-5: ARUFON UP-1000 (manufactured by Dong-A Synthetic Co., Ltd., acrylic resin)

[0169] B'-6: Youmex 1010 (manufactured by Sanyo Chemical Co., Ltd., maleic anhydride modified polypropylene (PP) resin, acid value: 52 mKOH / g)

[0170] <Colorant (C)>

[0171] C-1: Macrolex Violet B (manufactured by Bayer, anthraquinone dye, solvent violet 13)

[0172] C-2: Macrolex Red E2G GRAN (manufactured by Lanxess, a violet ketone dye, Solvent Red 179)

[0173] C-3: Tipaque CR-60 (manufactured by Ishihara Sangyo Co., Ltd., titanium dioxide, pigment white 6)

[0174] C-4: Paligen Red K3911 (manufactured by BASF, perylene pigment, Pigment Red 178)

[0175] C-5: #45L (Manufactured by Mitsubishi Chemical Corporation, Carbon Black, Pigment Black 7)

[0176] <Dilution Resin (D)>

[0177] D-1: Iupilon H-4000 (polycarbonate (PC) resin, manufactured by Mitsubishi Engineering Plastics)

[0178] D-2: Acrypet VH (acrylic resin, polymethyl methacrylate (PMMA) resin, manufactured by Mitsubishi Chemical Corporation)

[0179] D-3: Polyester MA-2101M (Polyester resin (PET), manufactured by Unitika)

[0180] D-4: Amilan CM3001-N (Polyamide resin (PA), manufactured by Toray Industries, Inc.)

[0181] [Example 1]

[0182] <Preparation of the liquid coloring composition (X-1)>

[0183] 100 parts by weight of liquid dispersion medium (A-1), 1 part by weight of surfactant (B-1), and 10 parts by weight of colorant (C-1) are mixed and dispersed using a bead mill to obtain liquid coloring composition (X-1).

[0184] [Examples 2-23]

[0185] <Preparation of liquid coloring compositions (X-2 to X-23)>

[0186] Except for changing the materials and contents (parts by mass) shown in Table 1, liquid coloring compositions (X-2 to X-23) were manufactured using the same method as liquid coloring composition (X-1).

[0187] [Comparative Example 1]

[0188] (Preparation of liquid coloring composition (Y-1))

[0189] 100 parts by weight of liquid dispersion medium (A-1) and 25 parts by weight of colorant (C-1) were mixed and dispersed using a bead mill, but the viscosity was high and the liquid resin composition (Y-1) could not be obtained.

[0190] [Comparative Examples 2-6]

[0191] Except for changing the materials and contents (parts by mass) as shown in Table 1, liquid coloring compositions (Y-2 to Y-6) were manufactured using the same method as liquid coloring composition (X-1).

[0192] <Evaluation of Liquid Coloring Compositions>

[0193] The dispersibility, storage stability, and supply accuracy of the obtained liquid coloring compositions were evaluated using the following methods. The results are shown in Table 1.

[0194] <Dispersion Evaluation>

[0195] In accordance with JIS K5600-2-5, using a 100 μm gauge, observe the points (dense spots) where significant spots begin to appear in the liquid coloring composition, and evaluate them according to the following criteria.

[0196] [Evaluation Criteria]

[0197] +++: Dense points ≤30 μm, very good.

[0198] ++: 30 μm < dense points ≤ 50 μm, good

[0199] +: 50 μm < dense point ≦ 70 μm, practically usable

[0200] NG: 70 μm < dense point, not practical.

[0201] <Evaluation of Preservation Stability>

[0202] Regarding storage stability, the obtained liquid coloring composition was left to stand for 30 days, and the separation and sedimentation of the colorant (C) in the liquid coloring composition were visually confirmed. The sedimentation stability was evaluated according to the following criteria.

[0203] [Evaluation Criteria]

[0204] +++: No separation, settling, excellent.

[0205] ++: There was some separation and sedimentation, but it became homogeneous and good when stirred.

[0206] +: There is separation and sedimentation, but it becomes homogeneous when stirred and is ready for practical use.

[0207] NG: Separation and sedimentation occur; even stirring will not produce a homogeneous mixture, rendering it unusable.

[0208] <Supply Accuracy>

[0209] The obtained liquid coloring composition was supplied for 10 minutes at a flow rate of 10 mL / min using an RP-NBC tube color roller pump (manufactured by Sanyo-Technos) and a high-strength silicone tube with a tube size of 1.6 mm × 3.2 mm. The average ejection volume was calculated every 10 seconds, based on the ejection volume furthest from the set value during the 10-minute supply period: Q x The ratio Q to the set flow rate: Q0 (=10 mL / min) x The value of / Q0 is used to evaluate the accuracy of supply according to the following criteria.

[0210] [Evaluation Criteria]

[0211] +++:0.9≦Q x / Q0≦1.1, Very good

[0212] ++: 0.85≦Q x / Q0 < 0.9 or 1.1 < Q x / Q0≦1.15, Good

[0213] +:0.8≦Q x / Q0 < 0.85 or 1.15 < Q x / Q0≦1.2, capable of practical use

[0214] NG: Q x / Q0 < 0.8 or 1.2 < Q x / Q0, not usable

[0215] [Table 1-1]

[0216]

[0217] [Table 1-2]

[0218]

[0219] [Example 24]

[0220] <Preparation of Coloring Resin Composition>

[0221] One part by weight of liquid coloring composition (X-1) and 100 parts by weight of diluted resin (D-1) were mixed and kneaded using a twin-screw extruder (manufactured by Nippon Steel Works, TEX25αIII) at a mixing temperature of 280°C and a screw speed of 200 rpm to obtain coloring resin composition (Z-1).

[0222] [Examples 25-49, Comparative Examples 7-11]

[0223] Except for changing the materials and contents (parts by mass) as shown in Table 2, the colored resin compositions (Z-2 to Z-30) were manufactured using the same method as in Example 24.

[0224] [Comparative Example 11]

[0225] 0.1 parts by weight of colorant (C-1) and 100 parts by weight of diluted resin (D-1) were mixed and kneaded at 280°C using a twin-screw extruder (manufactured by Nippon Steel Works, TEX25αIII) to obtain a colored resin composition (Z-31).

[0226] <Evaluation of Colored Resin Compositions>

[0227] The processability, color uniformity, appearance, and mechanical properties of the obtained colored resin compositions were evaluated using the following methods. The results are shown in Table 2.

[0228] <Processability>

[0229] Calculate the ejection amount (Q0) when extruding only the diluted resin (D) and the ejection amount (Q) of the coloring resin composition when the liquid coloring composition is added. x The ratio of (Q) x / Q0), evaluated according to the following criteria. Q x The higher the / Q0 value, the less variation in spraying caused by the addition of liquid coloring composition, indicating good processability.

[0230] [Evaluation Criteria]

[0231] +++:Q x / Q0≧0.95, Very good

[0232] ++:0.90≦Q x / Q0 < 0.95, good

[0233] +:0.85≦Q x / Q0 < 0.90, which is practical

[0234] NG: Q x / Q0 < 0.85, therefore not practical.

[0235] Uneven color

[0236] Using the obtained colored resin composition, 10 sheets of 150 mm × 130 mm × 2 mm were made using an injection molding machine (manufactured by Toshiba Machine Co., Ltd., injection pressure 100 t). Five sheets, from the 6th to the 10th sheet, were visually evaluated according to the following criteria.

[0237] [Evaluation Criteria]

[0238] +++: All 5 boards showed no color unevenness, excellent quality.

[0239] ++: One board with uneven coloring was confirmed; good.

[0240] +: It can be confirmed that there are 2 boards with uneven coloring, which are usable.

[0241] NG: More than 3 boards have been found to have uneven coloring, making them unusable.

[0242] <Appearance>

[0243] Observe the surface of the 5 plates used in the color unevenness evaluation, count the number of plates in which bubbles or flashes (the phenomenon of volatile components generated during molding appearing on the surface of the molded body) can be identified, and evaluate according to the following criteria.

[0244] [Evaluation Criteria]

[0245] +++: All 5 sheets were free of bubbles or flash, excellent quality.

[0246] ++: One board with visible bubbles or flashes is confirmed; good.

[0247] +: Two boards with visible bubbles or flashes are confirmed and are usable.

[0248] NG: If more than 3 boards show bubbles or flashes, the board cannot be used.

[0249] <Inter-shot deviation>

[0250] Using the obtained colored resin composition, 50 plates of 150 mm × 130 mm × 2 mm were made using an injection molding machine (manufactured by Toshiba Machine Co., Ltd., injection pressure 100 t). Using the plate from the 50th injection as the standard, the color difference (ΔE) of the plates from the 10th to the 49th injection was measured using a spectrophotometer 36dG (manufactured by Konica Minolta Co., Ltd.), and evaluated according to the following criteria.

[0251] [Evaluation Criteria]

[0252] +++: ΔE ≦ 0.3 for all boards, very good.

[0253] ++: There are fewer than 5 boards with ΔE > 0.3, which is considered good.

[0254] +: The number of boards with ΔE > 0.3 is less than 10, which is practical.

[0255] NG: There are more than 15 boards with ΔE > 0.3, making them unusable.

[0256] <Mechanical Properties>

[0257] Multi-object test specimens (80 mm long × 10 mm wide × 4 mm high) were formed using the obtained colored resin composition. The flexural temperature under a load of 1.80 MPa was determined according to JIS K7191-2. The flexural temperature (T0) of the uncolored diluted resin (D) and the flexural temperature (T0) of the colored resin composition were calculated. x The ratio of (T) x / T0), evaluated according to the following criteria. T x The higher the / T0 value, the less the mechanical properties are reduced due to the liquid coloring composition, which can be considered good.

[0258] [Evaluation Criteria]

[0259] +++:T x / T0≧0.95, Very good

[0260] ++:0.90≦T x / T0 < 0.95, good

[0261] +:0.85≦T x / T0 < 0.90, which is practical

[0262] NG:T x / T0 < 0.85, making it impractical.

[0263] [Table 2]

[0264] Table 2.

[0265]

[0266] As shown in Tables 1 and 2, the liquid coloring composition disclosed herein exhibits excellent dispersibility, storage stability, and supply precision. Furthermore, by using the liquid coloring composition, molded articles with uneven color and excellent appearance can be obtained without reducing the processability or mechanical properties of the diluted resin (D), thereby also reducing the deviation between injections of the molded articles.

[0267] By using the liquid coloring composition disclosed herein, it has been confirmed that even polycarbonate resins, acrylic resins, polyester resins, and polyamide resins, which are usually difficult to color uniformly, can be molded into molded articles with no color unevenness, excellent appearance, and good mechanical properties.

[0268] Furthermore, in Comparative Example 1, the viscosity was high, making it impossible to obtain a liquid coloring composition; in Comparative Example 3, the dispersibility of the liquid coloring composition was poor, making it impossible to form a molded article.

[0269] The present invention has been described with reference to several embodiments, but the present invention is not limited to these embodiments. Various modifications can be made to the structure or details of the present invention within the scope of the present invention.

[0270] The disclosure of this application is related to the subject matter described in Japanese Patent Application No. 2023-205824, filed on December 6, 2023, and all of its disclosure is incorporated herein by reference.

Claims

1. A liquid coloring composition comprising: 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 of less than 10,000 mPa·s at 25°C, a decomposition onset temperature of more than 250°C, and is at least one selected from the group consisting of aliphatic polyester resins, polyalkylene glycol resins, polyether ester 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.

2. The liquid coloring composition according to claim 1, wherein, The fatty acid esters include triglycerides.

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

4. The liquid coloring composition according to claim 1, wherein, The colorant (C) comprises 1 to 300 parts by mass relative to 100 parts by mass of the liquid dispersion medium (A).

5. The liquid coloring composition according to claim 1, wherein, The surfactant (B) comprises 0.5 to 30 parts by mass relative to 100 parts by mass of the liquid dispersion medium (A).

6. A coloring resin composition comprising the liquid coloring composition as described in any one of claims 1 to 5 and a diluent resin (D).

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

8. A molded body formed from the coloring resin composition as described in claim 7.

Images