Kraft lignin and method for producing same

Abstract

The purpose is to provide a cosmetic, an ink, printed matter, a coating material, an automobile paint, a coating, a plastic, fibers, a film, a black matrix resist, a photospacer resist, cured products thereof, etc., that contain Kraft lignin having absorption ability in the ultraviolet region which cuts absorption in the ultraviolet region.　It was discovered that Kraft lignin having a specific peak in an infrared absorption spectrum measured by a Fourier transform infrared spectrophotometer equipped with an ATR unit has high ultraviolet cutting capacity and can be used especially suitably for cosmetic applications due to the high L* value in color measurement by spectrophotometer, making it possible to solve the above problem.

Description

Kraft lignin and its manufacturing method

[0001] The present invention relates to kraft lignin and a method for producing the same.

[0002] Ultraviolet rays are generally said to accelerate skin aging, cause wrinkles and sagging, as well as cause age spots and skin cancer. Ultraviolet rays in the 280-320 nm UV-B range affect the surface layer of the skin, so excessive exposure tends to cause age spots and skin cancer, while ultraviolet rays in the 320-380 nm UV-A range penetrate deep into the skin, so excessive exposure tends to cause wrinkles and sagging.

[0003] Sunscreens containing UV-blocking agents such as UV absorbers and UV scattering agents are widely used in daily life to protect the skin from UV rays. However, in recent years, there has been a growing movement to ban, restrict, or treat the use of these UV protection agents as a cause for concern from the perspectives of environmental protection and reducing harmful effects on human health.

[0004] For example, the state of Hawaii in the United States has passed a bill banning the sale of sunscreens containing certain synthetic organic chemicals that are known to be harmful to coral reefs. Furthermore, in Europe, the REACH regulations have raised the health hazard of titanium oxide to Category 2 in the GHS classification. Furthermore, UV scattering agents commonly used in sunscreen compositions, such as zinc oxide and cerium oxide, are also categorized as Category 1 or Category 2 in terms of specific target organ toxicity, and therefore cannot necessarily be said to be safe for the human body.

[0005] Given this background, attention has been focused on UV absorbers derived from natural products. Naturally-derived UV absorbers have traditionally been used in cosmetics, including sunscreens, from a safety perspective. However, because many of them are water-soluble, they disperse poorly in oily ingredients and are washed away by sweat during use. For example, UV absorbers extracted from seaweed are sufficiently safe because they are derived from natural products, but they are water-soluble and have issues with water resistance. Furthermore, because their absorption edge is approximately 350 nm, their UV protection against UV-A is insufficient compared to UV-B (Patent Documents 1 and 2). UV absorbers derived from plant-dwelling microorganisms are also sufficiently safe because they are derived from natural products, but while they have UV-A absorption capabilities, they have issues with insufficient UV-B absorption capabilities. Furthermore, they also have issues with water resistance (Patent Document 3).

[0006] On the other hand, UV-blocking agents in which the surface of pigments is coated with UV-blocking agents made from naturally occurring raw materials in order to improve dispersibility in oily components have indeed improved dispersibility, but have only been able to exhibit the UV-absorbing ability that the pigments inherently possess (Reference 4).

[0007] Furthermore, although there is prior art in which naturally occurring lignin is used as an additive for lead-acid batteries, lignin itself has a strong brown to black appearance, and therefore has not been used in paint applications, let alone in cosmetics intended to beautify the appearance (Reference 5).

[0008] When using lignin in cosmetics, paints, and the like, it is preferable that the lignin be microparticulated. However, there has been a problem in that the particle formation concentration is very low and the yield of lignin relative to the volume of the production equipment is low, resulting in very low productivity (Non-Patent Documents 1 and 2).

[0009] Japanese Patent Application Laid-Open No. 8-188521 Japanese Patent Application Laid-Open No. 2004-238519 Japanese Patent Application Laid-Open No. 2013-127027 Japanese Patent Application Laid-Open No. 2018-162400 Japanese Patent Application Laid-Open No. 2003-331908

[0010] Green synthesis of lignin nano- and micro-particles: Physicochemical characterization, bioactive properties and cytotoxicity assessment, International Journal of Biological Macromolecules 163 (2020) 1798-1809Understanding Ligning Aggregation Processes. A Case Study: Budesonide Entrapment and Stimuli Controlled Release from Lignin Nanoparticles, ACS Sustainable Chem. Eng. 2018, 6, 9342-9351

[0011] The problem to be solved by the present invention is to provide kraft lignin that blocks light in the ultraviolet region, and to provide cosmetics, inks, printed materials, paints, automotive paints, coatings, plastics, fibers, films, resists for black matrices, resists for photospacers, and cured products thereof, which contain kraft lignin that has the ability to absorb light in the ultraviolet region.

[0012] As a result of intensive research to solve the above-mentioned problems, the inventors have found that kraft lignin having a specific peak in the infrared absorption spectrum measured by the attenuated total reflection (ATR) method, which is one of the infrared spectroscopy methods, i.e., a Fourier transform infrared spectrophotometer (hereinafter referred to as ATR-FT-IR) equipped with an ATR unit, can be measured by a spectrophotometer to measure L * The inventors have found that the above-mentioned problems can be solved by using the compound in cosmetics because it has a high UV absorption capacity and a high luminance.

[0013] That is, the present invention includes the following.

[0014] [1] Kraft lignin characterized in that in an infrared absorption spectrum measured by ATR-FT-IR, the ratio of the area of ​​the absorption peak at 3000 to 3600 cm-1 to the area of ​​the absorption peak at 1480 to 1540 cm-1 (1480 to 1540 cm-1 / 3000 to 3600 cm-1) is in the range of 3.0 to 6.0, and in color measurement measured with a spectrophotometer, the L* value is in the range of 61 to 80. [2] Kraft lignin according to 1, having a median diameter D50 of 0.1 to 0.8 μm. [3] Kraft lignin having a coating amount of 1.0 mg / cm per unit area in the ISO 24443 measurement method. 2[4] The kraft lignin according to any one of [1] to [3], wherein, when the kraft lignin is applied in an amount of 1.0 mg / cm2 per unit area, the SPF (Sun Protection Factor) value measured using an SPF (Sun Protection Factor) analyzer is in the range of 10 to 50. [5] The kraft lignin according to any one of [1] to [4], wherein, when the kraft lignin is applied in an amount of 1.0 mg / cm2 per unit area, the PA (Protection Grade of UVA) value measured using an SPF (Sun Protection Factor) analyzer is in the range of 10 to 50. [6] The kraft lignin according to any one of [1] to [4], wherein, when the kraft lignin is applied in an amount of 1.0 mg / cm2 per unit area, the PA (Protection Grade of UVA) value measured using an SPF (Sun Protection Factor) analyzer is in the range of 10 to 50. [7] The kraft lignin according to any one of [1] to [4], wherein the kraft lignin has an active radical scavenging ability of 2,2-diphenyl-1-picrylhydrazyl (DPPH) per unit weight of the kraft lignin is 1.0 to 3.0 mgDPPH / mg. [6] A method for producing kraft lignin according to any one of [1] to [5], comprising the steps of:

[0022] dissolving kraft lignin in an organic solvent to obtain a kraft lignin solution;

[0023] adding ice or ice water to the kraft lignin solution, or adding the kraft lignin solution to ice or ice water, to precipitate kraft lignin and obtain the precipitated lignin; and

[0024] filtering, washing, and drying the precipitated kraft lignin to obtain kraft lignin. [7] A method for producing kraft lignin according to any one of [1] to [5], comprising the steps of:

[0025] dissolving kraft lignin in an organic solvent to obtain a kraft lignin solution;

[0026] adding an aqueous solution of a water-soluble metal salt to the kraft lignin solution, or adding the kraft lignin solution to an aqueous solution of a water-soluble metal salt, to precipitate kraft lignin; and

[0027] filtering, washing, and drying the precipitated kraft lignin to obtain kraft lignin. [8] The present invention provides cosmetics, inks, printed materials, paints, automotive paints, coatings, plastics, fibers, films, resists for black matrices, resists for photospacers, and cured products thereof, each containing the kraft lignin according to any one of [1] to [5].

[0015] The kraft lignin of the present invention has a high SPF (Sun Protection Factor) value and a high UVA (Protection Grade of UVA) value, and has a high ultraviolet scattering and reflection ability. * Because of its high UV absorption value, it can be suitably used in white cosmetics, particularly sunscreens, foundations, face packs, and skin care creams. Furthermore, because 2,2-diphenyl-1-picrylhydrazyl (DPPH) has a high active radical scavenging ability, when used in cosmetics it is effective for anti-aging, anti-wrinkle, and anti-blemishes. Furthermore, because of its high UV absorption ability, it can be used as a colorant or additive in a wide range of fields, including inks, printed materials, paints, automotive paints, coatings, plastics, fibers, films, black matrix resists, photospacer resists, and their cured products, in addition to cosmetics.

[0016] FIG. 1 shows an infrared absorption spectrum of the kraft lignin of the present invention measured by ATR-FT-IR.

[0017] The following embodiments of the present invention merely represent some of the embodiments of the present invention, and the present invention is not limited to the described contents as long as the gist of the invention is not significantly deviated from.

[0018] [Lignin] Lignin is one of the main components of plants, and is a phenolic polymer compound found in large amounts in conifers, broad-leaved trees, and grasses. It plays a role in bonding fibers together in the plant cell walls. In the papermaking process, lignin is obtained from black liquor, a by-product of cooking wood chips to produce pulp.

[0019] [Kraft Lignin] Kraft lignin is a type of lignin. The resulting chemical structure of lignin varies depending on the cooking method. As a result, its solubility in solvents, including water, also varies significantly. The present invention relates to kraft lignin. Kraft lignin is obtained from black liquor, a by-product of obtaining pulp from wood chips using the kraft cooking method. Unlike lignin sulfonates, which are lignins obtained using the existing sulfite cooking method, kraft lignin is less soluble in water, has a low molecular weight, contains many thiol groups, and has few sulfonic acid groups.

[0020] The kraft lignin of the present invention is characterized in that in its infrared absorption spectrum measured by ATR-FT-IR, the ratio of the area of ​​the absorption peak at 3000-3600 cm-1 to the area of ​​the absorption peak at 1480-1540 cm-1 (1480-1540 cm-1 / 3000-3600 cm-1) is in the range of 3.0 to 6.0. Unlike known kraft lignins, the kraft lignin exhibits the above-mentioned characteristic infrared absorption spectrum due to the presence of many hydroxyl groups on the surface. The ATR-FT-IR measurement conditions are described below.

[0021] The FT-IR spectroscopy was performed using a Fourier transform infrared spectrophotometer FT / IR-6100 manufactured by JASCO Corporation equipped with an ATR unit.

[0022] The kraft lignin of the present invention is characterized by a large amount of hydroxyl groups involved in antioxidant activity. The amount of hydroxyl groups is measured by ATR-FT-IR and has a peak of 3000 to 3600 cm -1 and the area of ​​the peak at 1480 to 1540 cm indicating a hydrocarbon group. -1 The peak area ratio was calculated.

[0023] The amount of hydroxyl groups is in the range of 2.0 to 5.0 in terms of the area ratio, and the higher the amount of hydroxyl groups, the higher the antioxidant capacity, because the antioxidant capacity depends on the amount of phenolic hydroxyl groups that capture free radicals.

[0024] In ATR-FT-IR, only the part that comes into contact with the prism is reflected in the measurement results, so the finely divided kraft lignin has a hydroxyl group-indicating wavelength of 3000 to 3600 cm.-1 and the area of ​​the peak at 1480 to 1540 cm indicating a hydrocarbon group. -1 The area ratio of the peaks increases.

[0025] The kraft lignin of the present invention is characterized by a median diameter D50 of 0.1 to 0.8 μm. While general kraft lignins have a brownish hue when the median diameter D50 is in the range of 0.1 to 0.8 μm, the kraft lignin of the present invention has a whitish hue and exhibits a color measurement of L * The kraft lignin of the present invention is characterized by a color having a D50 value in the range of 61 to 80. The kraft lignin of the present invention preferably has a D50 of 0.15 to 0.6 μm and an L* value of 65 to 80.

[0026] Furthermore, in the ISO 24443 measurement method, when the amount of kraft lignin applied was 1 mg / cm2 per unit area, the SPF value measured using an SPF analyzer was in the range of 10 to 50, demonstrating that the UV blocking ability is far higher than that of known kraft lignins.

[0027] Furthermore, it was also found that the kraft lignin of the present invention has a high active radical scavenging ability of 2,2-diphenyl-1-picrylhydrazyl (DPPH) per unit weight of kraft lignin of 1.0 to 3.0 mg DPPH / mg.

[0028] Therefore, the kraft lignin of the present invention has a whitish hue and high UV-blocking ability, making it suitable for use in sunscreens, foundations, face packs, and skin care creams. Furthermore, due to the high active radical scavenging ability of 2,2-diphenyl-1-picrylhydrazyl (DPPH), when used in cosmetics, it is effective for anti-aging, anti-wrinkle, and anti-blemish. Furthermore, due to its high UV-absorbing ability, it can be used as a colorant or additive in a wide range of fields, including inks, printed materials, paints, automotive paints, coatings, plastics, fibers, films, black matrix resists, photospacer resists, and their cured products, in addition to cosmetics.

[0029] [Method for Producing Kraft Lignin] The kraft lignin of the present invention can be obtained by dissolving kraft lignin in a good solvent such as an organic solvent, and adding ice, ice water, or a water-soluble metal salt aqueous solution to the kraft lignin solution, or by adding the kraft lignin solution dropwise to ice, ice water, or a water-soluble metal salt aqueous solution.

[0030] The kraft lignin of the present invention is obtained by dissolving the raw material kraft lignin in an organic solvent and then reprecipitation. In a typical reprecipitation process in which a miscible poor solvent is added to a polymer solution to precipitate the polymer, the precipitated polymer has a size of 1 mm to several cm. The reason for such large size precipitation is that the polymer precipitates in the form of sticky fine particles during precipitation and self-aggregates.

[0031] In the present invention, ice, ice water, or a water-soluble metal salt solution is used to prevent the self-aggregation and obtain submicron-sized kraft lignin.

[0032] Specifically, ice, ice water, or a water-soluble metal salt aqueous solution is added as the poor solvent. When ice is added, the lignin precipitates in a cooled state by the ice, so the adhesion of the precipitated microparticles is lost, the precipitated microparticles do not aggregate, the good solvent is removed, and the kraft lignin of the present invention can be obtained in the size of precipitated microparticles. When ice water is added, the kraft lignin of the present invention can be obtained in the form of precipitated microparticles for the same reason as when ice is added. The ice water used in the present invention refers to ice water in which 20 parts by weight or more of ice are added to 100 parts by weight of water, and the temperature is 4°C or lower.

[0033] When a water-soluble metal salt aqueous solution is added as a poor solvent, the dissolved salt penetrates between the adhesive fine particles, preventing the precipitated fine particles from aggregating, and kraft lignin can be obtained in the form of precipitated fine particles.

[0034] Organic solvents that can be used in the production of kraft lignin of the present invention include methanol, ethanol, ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, polypropylene glycol, glycerin, butyl cellosolve, butyl carbitol, glycerin, acetone, tetrahydrofuran (THF), dimethylformamide (DMF), dimethyl sulfoxide (DMSO), and N-methyl-2-pyrrolidinone (NMP), with ethanol and ethylene glycol being particularly preferred. The organic solvent is used in a weight ratio of 2 to 20 times the weight of the raw material kraft lignin. If the kraft lignin dissolves, using a small amount of solvent is cost-effective. However, considering cost and solution viscosity, it is preferable to use the organic solvent in a ratio of 3 to 10 times.

[0035] Examples of water-soluble metal salts that can be used in the water-soluble metal salt aqueous solution used to produce kraft lignin of the present invention include sodium chloride, potassium chloride, calcium chloride, magnesium chloride, sodium sulfate, potassium sulfate, calcium sulfate, magnesium sulfate, sodium acetate, potassium acetate, calcium acetate, magnesium acetate, sodium phosphate, potassium phosphate, calcium phosphate, magnesium phosphate, sodium nitrate, potassium nitrate, calcium nitrate, and magnesium nitrate, but mixtures of these salts may also be used. From a cost perspective, sodium chloride is most preferred. Furthermore, the water-soluble metal salt aqueous solution can be used at a concentration up to the point where it becomes saturated by weight, but is preferably used at a concentration of 1 to 20%.

[0036] The dissolution temperature of the organic solvent during the production of the kraft lignin of the present invention significantly affects the active radical scavenging ability of the resulting kraft lignin, so dissolution is preferably carried out at 100°C or below. More preferably, room temperature is preferred in order to preserve the active radical scavenging ability. Similarly, the temperature during precipitation is preferably controlled at 10°C or below, as this significantly affects particle size. Therefore, the kraft lignin of the present invention is precipitated by adding ice to the kraft lignin solution, or vice versa, by dripping or pouring the kraft lignin solution into ice. The kraft lignin of the present invention exhibits a whitish hue because the particles are prepared without a heating step that would lead to coloration. Furthermore, this production process is characterized by the fact that it does not require a complex continuous process and allows kraft lignin particles to be easily prepared batchwise.

[0037] Furthermore, the substance dropped or added for particle precipitation needs only to be a poor solvent for precipitating kraft lignin. However, in a water-only system, the viscous material immediately after precipitation aggregates, forming large brown particles. Therefore, when using water as a poor solvent, adding a dispersant, additive, or a mixture of water and an organic solvent makes it possible to produce small particles. Regarding precipitation conditions, systems other than those mentioned above can also be used as long as the solubility of kraft lignin is reduced and a state in which precipitation is possible is achieved.

[0038] As the poor solvent, ice or cold water can be used, and ice is particularly suitable because it is easy to suppress the viscosity of the particles immediately after precipitation. When ice, ice water, or cold water is used, additional equipment such as an ice maker or a cooling machine is required, so in consideration of production costs, it is preferable to use a water-soluble metal salt aqueous solution described below.

[0039] Examples of the water-soluble metal salt aqueous solution that can be used include sodium chloride, potassium chloride, calcium chloride, magnesium chloride, sodium sulfate, potassium sulfate, calcium sulfate, magnesium sulfate, sodium acetate, potassium acetate, calcium acetate, magnesium acetate, sodium phosphate, potassium phosphate, calcium phosphate, magnesium phosphate, sodium nitrate, potassium nitrate, calcium nitrate, and magnesium nitrate. Of these water-soluble metal salt aqueous solutions, sodium chloride is most preferred in terms of cost. The water-soluble metal salt aqueous solution can be used at a concentration up to a saturated aqueous solution by weight, but is preferably used at a concentration of 1 to 20%.

[0040] In addition to cosmetics, the kraft lignin of the present invention can be used in a wide range of fields, including inks, printed materials, paints, automotive paints, coatings, plastics, fibers, films, resists for black matrices, resists for photospacers, and cured products thereof. The applications detailed below are examples, and the kraft lignin of the present invention can be used in any application as an additive for the purposes of providing effects such as UV protection, antioxidant properties, and coloring.

[0041] (Cosmetic Applications) When the kraft lignin of the present invention is used as an antioxidant and UV protection agent in foundations, creams, or sunscreen compositions, clay minerals such as talc, synthetic phlogopite, mica, and kaolin are used as extender pigments. Synthetic inorganic powders such as titanium oxide, boron nitride, zinc oxide, aluminum hydroxide, zinc chloride, lithium silicate, magnesium silicate, sodium silicate, tin oxide, iron oxide, barium sulfate, silica, and hydrated silica are used. Silicone polymers and polymeric microparticles are used to provide slipperiness. Examples of silicone polymers that can be used include dimethicone, (stearoxymethicone / dimethicone) copolymer, carboxydecyltrisiloxane, hydrogen dimethicone, tetrahydrotetramethylcyclotetrasiloxane, aminopropyltriethoxysilane, cyclomethicone, dimethiconol, trifluoroalkyldimethyltrimethylsiloxysilicate, hydrogen dimethicone, and methicone. As the polymeric fine particles, nylon-12, (methyl methacrylate / acrylonitrile) copolymer, methyl methacrylate, (hydrogenated polybutadiene / glycol / HDI) copolymer are used.

[0042] Antioxidants and preservatives include BHT, phenoxyethanol, tocopherol, chlorphenexin, methylparaben, ethylparaben, etc. Moisturizing agents include sodium acetyl hyaluronate, sodium hyaluronate, and water-soluble collagen.

[0043] Examples of organic substances that form the organic layer include tri(caprylic / capric)glyceryl, stearic acid, dextrin palmitate, ethylhexylglycerin, glycerin, isobutane, isopentane, tetracene, lauroyl lysine, ascorbic acid, olive fruit oil, hydroxyproline, isotridecyl isononanoate, cetyl ethylhexanoate, ethylhexylglycerin, diethylhexyl succinate, squalane, stearic acid, sorbitan sesquistearate, triethylhexanoin, hydrogenated polyisobutene, hydrogenated lecithin, PG dicaprylate, hydrogenated polyisobutene, hydrogenated castor oil isostearate, sorbitan isostearate, diisostearyl malate, tri(caprylic / capric)glyceryl, BG, sodium lauroyl aspartate, DPG, and isostearyl alcohol. As UV protection agents, in addition to ethylhexyl methoxycinnamate, titanium oxide, zinc oxide, and the like are used as synthetic inorganic powders. When the above materials are emulsified and used, water is used as a medium. For example, when the kraft lignin of the present invention is used to make a foundation, the above raw materials are mixed and then molded into a foundation. The kraft lignin of the present invention can be used, among other cosmetic applications, particularly as a sunscreen. The sunscreen mainly contains the UV protection agent of the present invention, an oily component, and an aqueous component such as water or alcohol, and is preferably in the form of a liquid, emulsion, gel, or cream. The sunscreen can also be used in packs, masks, nonwoven fabrics, etc., containing the sunscreen.

[0044] The oily component may be one or more of higher alcohols, hydrocarbon oils, ester oils, silicones, etc. Hydrocarbon waxes may also be included. When the sunscreen contains an oily component, the content of the oily component is preferably 1 to 99 wt % based on the total weight of the sunscreen.

[0045] The aqueous component can be water used in cosmetics, quasi-drugs, etc., and can be purified water, ion-exchanged water, tap water, etc. The alcohol can be a water-soluble alcohol, and can be one or more selected from lower alcohols, polyhydric alcohols, polyhydric alcohol polymers, glycerin monoalkyl ethers, sugar alcohols, monosaccharides, oligosaccharides, and derivatives thereof.

[0046] In addition to the above-mentioned components, the sunscreen may contain, as needed, powders other than the UV-blocking agent of the present invention, UV-absorbers other than the UV-blocking agent of the present invention, surfactants, water-soluble polymers, moisturizers, film-forming agents, sequestering agents, amino acids, organic amines, polymer emulsions, pH adjusters, skin nutrients, vitamins, antioxidants, fragrances, and the like. Powders other than the kraft lignin of the present invention may be any known or commonly used powder used in ordinary sunscreens, including inorganic powders such as magnesium oxide, calcium carbonate, talc, synthetic mica, mica, kaolin, montmorillonite, zeolite, ceramic powder, boron nitride, and alumina; inorganic pigments such as iron oxide, titanium oxide, zinc oxide, and ultramarine; organic pigments such as Red No. 202, Red No. 204, Yellow No. 4, Yellow No. 202, Blue No. 1, Blue No. 201, Green No. 3, Green No. 204, Orange No. 201, and Orange No. 207; natural pigments such as turmeric pigments, carotene pigments, cochineal pigments, monascus pigments, chlorophyll pigments, spirulina pigments, and squid ink pigments; lakes of natural pigments; and effect pigments such as titanium oxide-coated mica, titanium oxide-coated mica, and titanium oxide-coated glass.

[0047] As the ultraviolet absorber other than the ultraviolet blocking agent of the present invention, benzoic acid-based ultraviolet absorbers, salicylic acid-based ultraviolet absorbers, cinnamic acid-based ultraviolet absorbers, benzophenone-based ultraviolet absorbers, etc. can be used.

[0048] The surfactant may be an anionic surfactant, a cationic surfactant, an amphoteric surfactant, a lipophilic nonionic surfactant, a hydrophilic nonionic surfactant, etc. The content of the surfactant is preferably 5 to 15% by mass relative to the total mass of the cosmetic composition of the present invention.

[0049] As the water-soluble polymer, natural and synthetic water-soluble polymers can be used, and natural polymers include plant-based polymers such as gum arabic, guar gum, and starch, microbial polymers, and animal-based polymers such as collagen and gelatin. Synthetic polymers include starch-based polymers, cellulose-based polymers, alginic acid-based polymers, vinyl-based polymers, and acrylic-based polymers.

[0050] As the moisturizing agent, proteins, mucopolysaccharides, collagen, elastin, and keratin can be used.

[0051] Examples of the film-forming agent that can be used include anionic, cationic, and nonionic film-forming agents. Examples of the sequestering agent that can be used include tetrasodium edetate, sodium citrate, sodium polyphosphate, and ascorbic acid. Examples of the amino acid that can be used include neutral amino acids, basic amino acids, and amino acid derivatives. Examples of the organic amine that can be used include diethanolamine, triethanolamine, and triisopropanolamine. Examples of the polymer emulsion that can be used include acrylic resin emulsions, natural rubber latex, and silicone emulsions. Examples of the pH adjuster that can be used include buffers such as sodium lactate, sodium citrate, and sodium succinate. Examples of the vitamins that can be used include vitamin A, vitamin B1, vitamin B2, vitamin C, and vitamin E. Examples of the antioxidant that can be used include tocopherols, dibutylhydroxytoluene, and gallic acid esters. Examples of the fragrance that can be used include fragrances that are commonly used in sunscreens and are well known and commonly used fragrances.

[0052] Further, other ingredients that can be used include antiseptics, anti-inflammatory agents, whitening agents, activators, blood circulation promoters, anti-inflammatory agents, bactericidal agents, and antiviral agents.

[0053] The sunscreen can be prepared by heating the components to 20 to 80°C or at room temperature and dissolving them with stirring. Any known stirring method can be used, and for example, a blade stirrer, a disperser, a homomixer, or the like can be used. The sunscreen can be obtained by cooling the dissolved and homogenized mixture to room temperature. Depending on the formulation of the cosmetic composition, a liquid cosmetic in the form of a liquid, paste, gel, or the like can be obtained upon cooling.

[0054] (Application to Paints) When the kraft lignin of the present invention is used as a colorant, UV protection agent, or antioxidant in paints, various resins can be used in the paints, such as acrylic resins, melamine resins, epoxy resins, polyester resins, polyurethane resins, polyamide resins, and phenolic resins.

[0055] Solvents used in paints include aromatic solvents such as toluene, xylene, and methoxybenzene; acetate ester solvents such as ethyl acetate, butyl acetate, propylene glycol monomethyl ether acetate, and propylene glycol monoethyl ether acetate; propionate solvents such as ethoxyethyl propionate; alcohol solvents such as methanol, ethanol, propanol, n-butanol, and isobutanol; ether solvents such as butyl cellosolve, propylene glycol monomethyl ether, diethylene glycol ethyl ether, and diethylene glycol dimethyl ether; ketone solvents such as methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; aliphatic hydrocarbon solvents such as hexane; nitrogen compound solvents such as N,N-dimethylformamide, γ-butyrolactam, n-methyl-2-pyrrolidone, aniline, and pyridine; lactone solvents such as γ-butyrolactone; carbamate esters such as a 48:52 mixture of methyl carbamate and ethyl carbamate; and water. Suitable solvents include polar solvents such as propionates, alcohols, ethers, ketones, nitrogen compounds, lactones, and water, which are soluble in water.

[0056] When kraft lignin is dispersed or mixed in a liquid resin to form a resin coating composition, conventional additives such as dispersants, fillers, coating aids, driers, plasticizers, and / or auxiliary compounds can be used. This can be achieved by dispersing or mixing each component alone or several together, by collecting all the components, or by adding them all at once.

[0057] Dispersing machines for dispersing the kraft lignin-containing composition of the present invention prepared for the intended use as described above include, but are not limited to, known dispersing machines such as a Disper, Homomixer, Paint Conditioner, Scandex, Bead Mill, Attritor, Ball Mill, Two-Roll Mill, Three-Roll Mill, and Pressure Kneader. The compound is dispersed by adding a resin and a solvent to achieve a viscosity that allows dispersion using these dispersing machines. The resulting high-concentration paint base has a solids content of 5 to 20%, and is further mixed with a resin and a solvent for use as a paint.

[0058] (Automotive Paint Application) When the kraft lignin of the present invention is used as a colorant in automotive paint, various resins can be used in the paint, such as acrylic resin, melamine resin, epoxy resin, polyester resin, polyurethane resin, polyamide resin, and phenolic resin.

[0059] In recent years, water-based paints or powder electrodeposition paints are suitable for automobile paints in view of VOC control.

[0060] When kraft lignin is dispersed or mixed in a liquid resin or dry blend to form a resin coating composition, conventional additives such as dispersants, fillers, coating aids, driers, plasticizers, and / or auxiliary compounds can be used. This can be achieved by dispersing or mixing each component alone or several together, by collecting all the components, or by adding them all at once.

[0061] (Inkjet Ink Use) The kraft lignin of the present invention can be suitably used in inkjet inks, and in particular, can be suitably used in aqueous inkjet inks as an aqueous compound dispersion obtained by dispersing the kraft lignin using a dispersant or the like. The aqueous compound dispersion can be prepared by preparing a high-concentration aqueous dispersion (compound paste) of the condensed polycyclic organic compound of the present invention, diluting it with a water-soluble solvent and / or water, and adding other additives as necessary.

[0062] The method for dispersing the kraft lignin of the present invention in the water-soluble solvent and / or water to obtain a compound paste is not particularly limited, and it is preferable to use a known dispersion method. The dispersant used may be a known compound dispersant for dispersing in water, or a surfactant may be used. The compound dispersant is preferably an aqueous resin, and preferred examples include polyvinyl alcohols, polyvinylpyrrolidones, urethane resins having anionic or cationic groups, and radical copolymer resins having anionic or cationic groups. Examples of radical copolymer resins having anionic or cationic groups include acrylic resins such as acrylic acid-acrylic acid ester copolymers, styrene-acrylic acid copolymers, styrene-methacrylic acid copolymers, styrene-methacrylic acid-acrylic acid ester copolymers, styrene-α-methylstyrene-acrylic acid copolymers, styrene-α-methylstyrene-acrylic acid-acrylic acid ester copolymers, and other styrene-acrylic resins, styrene-maleic acid copolymers, styrene-maleic anhydride copolymers, vinylnaphthalene-acrylic acid copolymers, and salts of these aqueous resins.

[0063] Examples of compounds for forming salts of the copolymer include alkali metal hydroxides such as sodium hydroxide, potassium hydroxide, and lithium hydroxide, as well as diethylamine, ammonia, ethylamine, triethylamine, propylamine, isopropylamine, dipropylamine, butylamine, isobutylamine, triethanolamine, diethanolamine, aminomethylpropanol, and morpholine. The amount of these salt-forming compounds used is preferably equal to or greater than the neutralization equivalent of the copolymer.

[0064] Of course, commercially available products can also be used, such as the Ajisper PB series manufactured by Ajinomoto Fine-Techno Co., Ltd., the Disperbyk series and BYK series manufactured by BYK Japan Co., Ltd., and the EFKA series manufactured by BASF Japan Ltd.

[0065] Further, examples of dispersion methods include the following (1) and (2). (1) A method of preparing a kraft lignin paste by adding kraft lignin to an aqueous medium containing a kraft lignin dispersant and water, and then dispersing the kraft lignin in the aqueous medium using a stirring and dispersing device. (2) A method of kneading kraft lignin and a kraft lignin dispersant using a kneading machine such as a two-roll mill or a mixer, adding the resulting kneaded mixture to an aqueous medium containing water, and preparing a compound paste using a stirring and dispersing device. (Toner Use) The kraft lignin of the present invention can also be used for toner coloring. When preparing a toner for developing electrostatic images, a film-forming thermoplastic resin that is solid at room temperature, such as a polyester resin, a polyamide resin, a styrene resin, or an acrylic resin, is used as the dispersing resin.

[0066] The toner for developing electrostatic images produced using the kraft lignin of the present invention as a constituent component can be used as a one-component magnetic toner containing a magnetic material (color toner for magnetic one-component development), a non-magnetic one-component color toner containing no magnetic material (color toner for non-magnetic one-component development), or a color toner for a two-component color developer mixed with a carrier (color toner for two-component development).

[0067] The one-component color magnetic toner can be composed of, for example, a colorant, a binder resin, a magnetic powder, and other additives such as a charge control agent (CCA) and a release agent, as is the case with commonly used toners.

[0068] The amount of the kraft lignin of the present invention used in the toner for developing electrostatic images is not particularly limited, but it is preferably used in a proportion of 0.5 to 25 parts by mass per 100 parts by mass of the binder resin, and more preferably 4 to 10 parts by mass per 100 parts by mass of the binder resin in order to further enhance the charging performance of the colorant itself.

[0069] As the binder resin used in the toner for developing electrostatic images, any of the known and commonly used resins exemplified as the thermoplastic resins can be used, but any of synthetic resins, natural resins, natural rubbers, synthetic rubbers, synthetic waxes, etc. that exhibit adhesive properties under application of heat or pressure can also be used.

[0070] (Black Matrix / Photospacer Applications) The kraft lignin of the present invention can be used to form a pattern for the black matrix portion of a color filter or for a photospacer for an LCD by a known method. Typically, a photosensitive composition for pattern formation can be obtained that contains the kraft lignin of the present invention and a photosensitive resin as essential components.

[0071] To prepare the photosensitive composition for pattern formation, for example, the kraft lignin of the present invention, a photosensitive resin, a photopolymerization initiator, and an organic solvent for dissolving the resin are mixed as essential components. A common method for producing the composition is to prepare a dispersion using the kraft lignin of the present invention, an organic solvent, and, if necessary, a dispersant, and then add the photosensitive resin and other components thereto.

[0072] The kraft lignin of the present invention used in the photosensitive composition for pattern formation may optionally contain a yellow compound. Examples of dispersants that may be used as needed include DISPERBYK (registered trademark) 130, 161, 162, 163, 170, LPN-6919, and LPN-21116 manufactured by BYK. Leveling agents, coupling agents, cationic surfactants, and the like may also be used in combination.

[0073] Examples of organic solvents include aromatic solvents such as toluene, xylene, and methoxybenzene; acetate ester solvents such as ethyl acetate, butyl acetate, propylene glycol monomethyl ether acetate, and propylene glycol monoethyl ether acetate; propionate solvents such as ethoxyethyl propionate; alcohol solvents such as methanol and ethanol; ether solvents such as butyl cellosolve, propylene glycol monomethyl ether, diethylene glycol ethyl ether, and diethylene glycol dimethyl ether; ketone solvents such as methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; aliphatic hydrocarbon solvents such as hexane; nitrogen compound solvents such as N,N-dimethylformamide, γ-butyrolactam n-methyl-2-pyrrolidone, aniline, and pyridine; lactone solvents such as γ-butyrolactone; carbamic acid esters such as a 48:52 mixture of methyl carbamate and ethyl carbamate; and water. Suitable organic solvents include polar solvents such as propionates, alcohols, ethers, ketones, nitrogen compounds, lactones, and water, which are soluble in water.

[0074] Examples of usable photosensitive resins include thermoplastic resins such as urethane resins, acrylic resins, polyamic acid resins, polyimide resins, styrene-maleic acid resins, and styrene-maleic anhydride resins; and photopolymerizable monomers such as bifunctional monomers such as 1,6-hexanediol diacrylate, ethylene glycol diacrylate, neopentyl glycol diacrylate, triethylene glycol diacrylate, bis(acryloxyethoxy)bisphenol A, and 3-methylpentanediol diacrylate; and polyfunctional monomers such as trimethylolpropane triacrylate, pentaerythritol triacrylate, tris(2-hydroxyethyl)isocyanate, dipentaerythritol hexaacrylate, and dipentaerythritol pentaacrylate. Examples of photopolymerization initiators include acetophenone, benzophenone, benzyl dimethyl ketal, benzoyl peroxide, 2-chlorothioxanthone, 1,3-bis(4'-azidobenzal)-2-propane, 1,3-bis(4'-azidobenzal)-2-propane-2'-sulfonic acid, 4,4'-diazidostilbene-2,2'-disulfonic acid, etc. The photosensitive composition for black matrix thus prepared can be subjected to pattern exposure with ultraviolet light through a photomask, and then the unexposed portions can be washed with an organic solvent, alkaline water, or the like to form a black matrix or spacer.

[0075] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. In the following examples, "%" in the compositions means "% by weight."

[0076] (Method for Measuring Particle Size Distribution) Particle size distribution was measured using Microtrac Nanowave II manufactured by Microtrac-Bell Inc. Water was used as the measurement medium, and dynamic light scattering of a semiconductor laser with a wavelength of 780 nm was subjected to frequency analysis to measure particle size distribution.

[0077] (Color Measurement) An integrating sphere unit ISN-923 was attached to a spectrophotometer V-770 manufactured by JASCO Corporation, and 0.1 g of a measurement sample was filled into a powder cell PSH-002. From the measured reflection spectrum from 360 to 830 nm, color measurement was performed in accordance with JIS Z 8781-4: 2013, CIE No. 15: 2004, ISO 11664-4: 2008, and ASTM E308: 2008 using the L*a*b* color system.

[0078] (SPF Measurement Method) SPF measurements were performed using a UV-2000S SPF analyzer manufactured by Labsphere in accordance with ISO 24443. A sample was applied to HERIOPLATE HD6 at a rate of 1.0 mg / cm to prepare an SPF measurement sample. For one SPF measurement sample, transmittance measurements were performed at nine different measurement points, and the SPF was calculated from the transmittance values.

[0079] (Hydroxyl group amount measurement) The amount of hydroxyl groups involved in the antioxidant activity of kraft lignin was measured at 3000 to 3600 cm －１ and absorption peaks at 1480-1540 cm －１ The ratio of the absorption peak area (1480-1540 cm －１ / 3000~3600cm －１ ) was measured using a Fourier transform infrared spectrophotometer FT / IR-6100 manufactured by JASCO Corporation. An ATR adapter was attached and the kraft lignin powder was measured as is. The amount of hydroxyl groups was determined as the ratio of hydroxyl groups to hydrocarbon groups. The ratio of hydroxyl groups to hydrocarbon groups was determined using a 3000 to 3600 cm -1 and the area of ​​the peak at 1480 to 1540 cm indicating a hydrocarbon group. -1 The peak area ratio was calculated.

[0080] (Measurement of Active Radical Scavenging Ability) The active radical scavenging ability associated with the antioxidant activity of kraft lignin was measured using 2,2-diphenyl-1-picrylhydrazyl (DPPH). The measurement method and results are shown below. Isopropanol was added to 20 mg of kraft lignin to prepare a 20 mg / L crude dispersion in isopropanol (IPA). This crude dispersion was subjected to ultrasonic dispersion for 30 seconds using a Hielscher UP400S to obtain a kraft lignin / IPA dispersion. Separately, a 0.20 mM IPA solution of 2,2-diphenyl-1-picrylhydrazyl (DPPH) was prepared, and the same amount was mixed with the kraft lignin / IPA dispersion and allowed to stand at room temperature for 2 hours. The absorbance of the solution after standing was measured at 518 nm, and the remaining amount of DPPH was calculated from a calibration curve obtained from the absorbance at 518 nm of 0.20 mM, 0.10 mM, 0.05 mM, and 0.02 mM DPPH / IPA solutions. The remaining amount of DPPH was subtracted from the initial DPPH concentration of 0.1 mM to determine the DPPH active radical scavenging ability of kraft lignin. The DPPH radical scavenging ability is expressed in units of DPPH / mg as the scavenging ability of DPPH active radicals per 1 mg of kraft lignin.

[0081] Example 1: 10 parts by weight of kraft lignin (manufactured by Nippon Paper Industries Co., Ltd.) was dissolved in 40 parts by weight of ethanol (first-grade reagent, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), and the insoluble matter was filtered and removed using filter paper. 200 parts by weight of ice was added to the resulting filtrate while stirring, causing the kraft lignin to precipitate. The resulting kraft lignin suspension was filtered, and the filter residue was washed with 200 parts by weight of ion-exchanged water. Filtration and washing with ion-exchanged water were repeated twice, and the resulting kraft lignin wet cake was vacuum-dried at 40°C for 2 hours. The resulting dried product was pulverized in a mortar to obtain 3 parts by weight of kraft lignin.

[0082] The median diameter, color, SPF value, PA value, ratio of hydroxyl groups to hydrocarbon groups, and active radical scavenging ability of kraft lignin were measured. As a result, the median diameter was 0.581 μm, the color was L ＊ = 73.39, a ＊ = 3.14, b ＊ = 20.69, SPF value is 21.6, PA value is 20.8, 3000-3600 cm－１ and absorption peaks at 1480-1540 cm －１ The ratio of the absorption peak area (1480-1540 cm －１ / 3000~3600cm －１ ) was 3.30, and the active radical scavenging activity was 1.57 mg DPPH / mg.

[0083] Example 2 Four parts by weight of kraft lignin was obtained in the same manner as in Example 1, except that ethanol was replaced with methanol (first-grade reagent, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.).

[0084] The median diameter, color, SPF value, PA value, ratio of hydroxyl groups to hydrocarbon groups, and active radical scavenging ability of kraft lignin were measured in the same manner as in Example 1. As a result, the median diameter was 0.672 μm, the hue was L*=70.71, a*=3.55, b*=20.53, the SPF value was 17.5, the PA value was 17.0, and the active radical scavenging ability was 3000-3600 cm. －１ and absorption peaks at 1480-1540 cm －１ The ratio of the absorption peak area (1480-1540 cm －１ / 3000~3600cm －１ ) was 3.62, and the active radical scavenging activity was 1.27 mg DPPH / mg.

[0085] Example 3 8 parts by weight of a cellulose acetate solution was obtained in the same manner as in Example 1, except that ethanol was replaced with ethylene glycol.

[0086] The median diameter, color, SPF value, PA value, ratio of hydroxyl groups to hydrocarbon groups, and active radical scavenging ability of kraft lignin were measured in the same manner as in Example 1. As a result, the median diameter was 0.629 μm, the color was L* = 61.05, a* = 4.83, b* = 17.06, the SPF value was 41.1, the PA value was 38.9, and the active radical scavenging ability was 3000-3600 cm. －１ and absorption peaks at 1480-1540 cm －１ The ratio of the absorption peak area (1480-1540 cm －１ / 3000~3600cm －１ ) was 4.07, and the active radical scavenging activity was 1.06 mg DPPH / mg.

[0087] Example 4 Seven parts by weight of kraft lignin was obtained in the same manner as in Example 1, except that ethanol was replaced with diethylene glycol.

[0088] The median diameter, color, SPF value, PA value, ratio of hydroxyl groups to hydrocarbon groups, and active radical scavenging ability of kraft lignin were measured in the same manner as in Example 1. As a result, the median diameter was 0.308 μm, the color was L* = 63.93, a* = 4.26, b* = 17.37, the SPF value was 22.2, the PA value was 21.1, and the active radical scavenging ability was 3000-3600 cm. －１ and absorption peaks at 1480-1540 cm －１ The ratio of the absorption peak area (1480-1540 cm －１ / 3000~3600cm －１ ) was 5.00, and the active radical scavenging activity was 1.04 mg DPPH / mg.

[0089] Example 5 8 parts by weight of kraft lignin was obtained in the same manner as in Example 1, except that ethanol was replaced with dimethylformamide.

[0090] The median diameter, color, SPF value, PA value, ratio of hydroxyl groups to hydrocarbon groups, and active radical scavenging ability of kraft lignin were measured in the same manner as in Example 1. As a result, the median diameter was 0.648 μm, the color was L* = 67.98, a* = 3.86, b* = 18.29, the SPF value was 11.6, the PA value was 11.4, and the active radical scavenging ability was 3000-3600 cm. －１ and absorption peaks at 1480-1540 cm －１ The ratio of the absorption peak area (1480-1540 cm －１ / 3000~3600cm －１ ) was 4.61, and the active radical scavenging activity was 0.96 mg DPPH / mg.

[0091] Example 6 8 parts by weight of kraft lignin was obtained in the same manner as in Example 1, except that ethanol was replaced with N,N-dimethylpyrrolidinone.

[0092] The median diameter, color, SPF value, PA value, ratio of hydroxyl groups to hydrocarbon groups, and active radical scavenging ability of kraft lignin were measured in the same manner as in Example 1. As a result, the median diameter was 0.505 μm, the color was L* = 68.69, a* = 3.61, b* = 18.21, the SPF value was 15.1, the PA value was 14.8, and the active radical scavenging ability was 3000-3600 cm. －１ and absorption peaks at 1480-1540 cm －１ The ratio of the absorption peak area (1480-1540 cm －１ / 3000~3600cm －１ ) was 4.64, and the active radical scavenging activity was 1.03 mg DPPH / mg.

[0093] Example 7: 10 parts by weight of kraft lignin was dissolved in 40 parts by weight of ethanol, and the insoluble matter was filtered and removed using filter paper. The resulting filtrate was added to 200 parts by weight of ice to precipitate kraft lignin. The kraft lignin suspension was filtered, and the filter residue was washed with 200 parts by weight of ion-exchanged water. Filtration and washing with ion-exchanged water were repeated twice, and the kraft lignin wet cake was vacuum-dried at 40°C for 2 hours. The resulting dried product was pulverized in a mortar to obtain 3 parts by weight of kraft lignin.

[0094] The median diameter, color, SPF value, PA value, ratio of hydroxyl groups to hydrocarbon groups, and active radical scavenging ability of kraft lignin were measured in the same manner as in Example 1. As a result, the median diameter was 0.595 μm, the color was L* = 72.34, a* = 3.28, b* = 20.64, the SPF value was 20.6, the PA value was 19.8, and the active radical scavenging ability was 3000-3600 cm. －１ and absorption peaks at 1480-1540 cm －１ The ratio of the absorption peak area (1480-1540 cm －１ / 3000~3600cm －１ ) was 3.2, and the active radical scavenging activity was 1.50 mg DPPH / mg.

[0095] Example 8 10 parts by weight of kraft lignin was dissolved in 40 parts by weight of industrial alcohol (Solmix AP-7), and insoluble matter was removed by filtration. 20 parts by weight of ethylene glycol was added to the obtained filtrate, and distillation under reduced pressure at 80°C was performed to obtain 25 parts by weight of an ethylene glycol solution of kraft lignin. 25 parts by weight of 10% saline was added to the obtained ethylene glycol solution of kraft lignin to precipitate kraft lignin. The kraft lignin suspension was filtered, and the filter residue was washed with 45 parts by weight of ion-exchanged water. Filtration and washing with ion-exchanged water were repeated five times, and the kraft lignin wet cake was dried at 40°C for two hours. The obtained dried product was pulverized in a mixer to obtain 5 parts by weight of kraft lignin.

[0096] The median diameter, color, SPF value, PA value, ratio of hydroxyl groups to hydrocarbon groups, and active radical scavenging ability of kraft lignin were measured in the same manner as in Example 1. As a result, the median diameter was 0.595 μm, the color was L* = 69.72, a* = 3.56, b* = 17.73, the SPF value was 23.6, the PA value was 21.8, and the active radical scavenging ability was 3000-3600 cm. －１ and absorption peaks at 1480-1540 cm －１ The ratio of the absorption peak area (1480-1540 cm －１ / 3000~3600cm －１ ) was 3.4, and the active radical scavenging activity was 1.24 mg DPPH / mg.

[0097] (Comparative Example 1) Kraft lignin (manufactured by Nippon Paper Industries Co., Ltd.) before treatment was similarly measured for median diameter, color, SPF value, PA value, ratio of hydroxyl groups to hydrocarbon groups, and active radical scavenging ability. The median diameter was 0.823 μm, the color was L*=51.19, a*=6.58, b*=16.41, the SPF value was 7.9, the PA value was 2.3, and the active radical scavenging ability was 3000-3600 cm. －１ and absorption peaks at 1480-1540 cm －１ The ratio of the absorption peak area (1480-1540 cm －１ / 3000~3600cm －１ ) was 2.83, and the active radical scavenging activity was 0.28 mg DPPH / mg.

[0098] Comparative Example 2 An attempt was made to prepare fine particles in the same manner as in Example 1, except that ice was replaced with water. However, the kraft lignin precipitated in the form of clumps, and it was not possible to prepare particles.

[0099] Comparative Example 3 An attempt was made to prepare particles in the same manner as in Example 1, except that ethanol was replaced with isopropanol, but the kraft lignin did not dissolve, and fine particles could not be prepared.

[0100] Comparative Example 4 An attempt was made to prepare particles in the same manner as in Example 1, except that ethanol was replaced with normal butanol, but the kraft lignin did not dissolve, and fine particles could not be prepared.

[0101] Comparative Example 5 Fine particles were prepared in the same manner as in Example 1, except that ethanol was replaced with acetone, to obtain 6 parts by weight of kraft lignin fine particles.

[0102] The median diameter, color, SPF value, PA value, ratio of hydroxyl groups to hydrocarbon groups, and active radical scavenging ability of the kraft lignin particles were measured in the same manner as in Example 1. The results were: median diameter 2.11 μm, color L* = 54.25, a* = 6.05, b* = 17.39, SPF value 25.5, PA value 23.3, and active radical scavenging ability 3000-3600 cm. －１ and absorption peaks at 1480-1540 cm －１ The ratio of the absorption peak area (1480-1540 cm －１ / 3000~3600cm －１ ) was 3.66, and the active radical scavenging activity was 0.77 mg DPPH / mg.

[0103] Comparative Example 6 An attempt was made to prepare fine particles in the same manner as in Example 1, except that ethanol was replaced with methyl ethyl ketone. However, the kraft lignin precipitated in the form of clumps, and it was not possible to prepare particles.

[0104] Comparative Example 7 An attempt was made to prepare fine particles in the same manner as in Example 1, except that ethanol was replaced with methyl isobutyl ketone. However, the kraft lignin did not dissolve, and fine particles could not be prepared.

[0105] Comparative Example 8 An attempt was made to prepare fine particles in the same manner as in Example 1, except that ethanol was replaced with butyl cellosolve. However, the kraft lignin precipitated in the form of lumps, and fine particles could not be prepared.

[0106] Comparative Example 9 9 parts by weight of kraft lignin fine particles were obtained in the same manner as in Example 1, except that ethanol was replaced with butyl carbitol.

[0107] The median diameter, color, SPF value, PA value, ratio of hydroxyl groups to hydrocarbon groups, and active radical scavenging ability of the kraft lignin microparticles were measured in the same manner as in Example 1. As a result, the median diameter was 5.78 μm, the color was L*=60.00, a*=6.84, b*=23.69, the SPF value was 20.7, the PA value was 20.6, and the active radical scavenging ability was 3000-3600 cm. －１ and absorption peaks at 1480-1540 cm －１ The ratio of the absorption peak area (1480-1540 cm －１ / 3000~3600cm －１ ) was 4.94, and the active radical scavenging activity was 0.61 mg DPPH / mg.

[0108] Comparative Example 10 Eight parts by weight of kraft lignin fine particles were obtained in the same manner as in Example 1, except that ethanol was replaced with tetrahydrofuran.

[0109] The median diameter, color, SPF value, PA value, ratio of hydroxyl groups to hydrocarbon groups, and active radical scavenging ability of the kraft lignin microparticles were measured in the same manner as in Example 1. As a result, the median diameter was 1.92 μm, the color was L* = 54.24, a* = 6.67, b* = 18.57, the SPF value was 29.7, the PA value was 17.6, and the active radical scavenging ability was 3000-3600 cm. －１ and absorption peaks at 1480-1540 cm －１ The ratio of the absorption peak area (1480-1540 cm －１ / 3000~3600cm －１ ) was 3.64, and the active radical scavenging activity was 0.14 mg DPPH / mg.

[0110] Comparative Example 11 An attempt was made to prepare fine particles in the same manner as in Example 1, except that ethanol was replaced with hexyl carbitol, but the kraft lignin did not dissolve, and fine particles could not be prepared.

[0111] Comparative Example 12 8 parts by weight of kraft lignin fine particles were obtained in the same manner as in Example 1, except that 10 parts by weight of kraft lignin was dissolved in 40 parts by weight of N,N-dimethylpyrrolidinone and then heated at 180° C. for 2 hours.

[0112] The median diameter, color, SPF value, PA value, ratio of hydroxyl groups to hydrocarbon groups, and active radical scavenging ability of the kraft lignin microparticles were measured in the same manner as in Example 1. As a result, the median diameter was 0.415 μm, the color was L* = 59.57, a* = 4.64, b* = 16.15, the SPF value was 29.7, the PA value was 18.0, and the active radical scavenging ability was 3000-3600 cm. －１ and absorption peaks at 1480-1540 cm －１ The ratio of the absorption peak area (1480-1540 cm －１ / 3000~3600cm －１ ) was 2.87, and the active radical scavenging activity was 0.904 mg DPPH / mg.

[0113] (Evaluation Example 1) A foundation cosmetic using the kraft lignin of the present invention was evaluated. The foundation cosmetic for evaluation was formulated according to the composition shown in Table 1. A comparative evaluation was carried out with the kraft lignin described in Example 8 of the present invention, the kraft lignin before treatment described in Comparative Example 1, four commercially available lignin materials, and a commercially available foundation cosmetic. The evaluation was carried out by SPF measurement.

[0114] Table 1 shows the formulation of the foundation for evaluation.

[0115]

[0116] SPF measurements were performed in accordance with ISO 24443 using a UV-2000S SPF analyzer manufactured by Labsphere. A sample was applied to HERIOPLATE HD6 at a rate of 0.5 mg / cm2 to prepare an SPF measurement sample. For one SPF measurement sample, transmittance measurements were performed at nine different measurement points, and the SPF was calculated from the transmittance values. The evaluation results are shown in Table 2.

[0117]

[0118] (Evaluation Example 2) A sunscreen cream using the kraft lignin of the present invention was evaluated. The sunscreen cream for evaluation was formulated according to the composition shown in Table 3. A comparative evaluation was carried out with the kraft lignin described in Example 8 of the present invention, the untreated kraft lignin described in Comparative Example 1, and four commercially available lignin materials. The evaluation was carried out by SPF measurement.

[0119] The sunscreen cream formulations for evaluation are shown in Table 3.

[0120]

[0121] SPF measurements were performed in accordance with ISO 24443 using a UV-2000S SPF analyzer manufactured by Labsphere. A sample was applied to HERIOPLATE HD6 at a rate of 2.0 mg / cm2 to prepare an SPF measurement sample. For one SPF measurement sample, transmittance measurements were performed at nine different measurement points, and the SPF was calculated from the transmittance values. The evaluation results are shown in Table 4.

[0122]

Claims

1. Kraft lignin characterized in that in an infrared absorption spectrum measured with a Fourier transform infrared spectrophotometer (ATR-FT-IR) equipped with an ATR unit, the ratio of the heights of the absorption peak at 3000 to 3600 cm-1 and the absorption peak at 1480 to 1540 cm-1 (1480-1540 cm-1 / 3000-3600 cm-1) is in the range of 3.0 to 6.0, and in color measurements measured with a spectrophotometer, the L* value is in the range of 61 to 80, and the median diameter (D50) is 0.1 to 0.8 μm.

2. The kraft lignin according to claim 1, wherein the SPF (Sun Protection Factor) measured using an SPF (Sun Protection Factor) analyzer is in the range of 10 to 50 when the application amount of the kraft lignin is 1 mg / cm2 per unit area in ISO 24443.

3. 3. The kraft lignin according to claim 1 or 2, wherein the PA (Protection Grade of UVA) value measured using an SPF (Sun Protection Factor) analyzer is in the range of 10 to 50 when the application amount of the kraft lignin is 1 mg / cm2 per unit area in ISO 24443.

4. The kraft lignin according to claim 1 or 2, wherein the active radical scavenging ability of 2,2-diphenyl-1-picrylhydrazyl (DPPH) per unit weight of the kraft lignin is 1.0 to 3.0 mg DPPH / mg.

5. A process for dissolving kraft lignin in an organic solvent in an amount of 3 to 10 times by weight relative to the amount of kraft lignin to obtain a kraft lignin solution; Next, a step of adding ice and ice water to the kraft lignin solution to precipitate the kraft lignin and obtain the precipitated lignin; Next, the precipitated kraft lignin is filtered, washed, and dried to obtain kraft lignin; The method for producing kraft lignin according to claim 1 or 2, characterized in that it comprises

6. A step of dissolving the kraft lignin in an organic solvent to obtain a kraft lignin solution; Next, adding a water-soluble metal salt aqueous solution to the kraft lignin solution, or adding the kraft lignin solution to a water-soluble metal salt aqueous solution to precipitate kraft lignin; Next, the precipitated kraft lignin is filtered, washed, and dried to obtain kraft lignin; The method for producing kraft lignin according to claim 1 or 2, characterized in that it comprises

7. 3. A foundation, a sunscreen, a cosmetic, an ink, a printed matter, a paint, an automotive paint, a coating, a plastic, a fiber, a film, a resist for a black matrix, a resist for a photospacer, and a cured product thereof, comprising the kraft lignin according to claim 1 or 2.