Method for producing polysaccharide-containing particles, precursor polysaccharide-containing particles, and polysaccharide-containing particles

Abstract

The present invention provides a polysaccharide-containing particle production method including a spray-drying step and a desalination step, wherein, at the spray-drying step, a dispersion including polysaccharides in salt form is spray-dried to obtain precursor polysaccharide-containing particles, and at the desalination step, the polysaccharides in salt form included in the precursor polysaccharide-containing particles are brought into contact with a desalination agent to desalinate the polysaccharides in salt form with the desalination agent and thus obtain polysaccharide-containing particles.

Description

Technical Field

[0001] The present invention relates to a method for producing polysaccharide-containing particles, precursor polysaccharide-containing particles, and polysaccharide-containing particles.

Background Art

[0002] Conventionally, particles containing polysaccharides have been widely used as additives in cosmetics, pharmaceuticals, foods, paints, and the like. For example, Patent Document 1 discloses a method for producing fine particles characterized by spray-drying an aqueous solution in which a water-soluble polysaccharide and a reactive resin or a water-soluble cross-linking agent are dissolved to form granules, and heat-treating the obtained particles to cross-link and insolubilize them in water. Further, Patent Document 2 discloses a method for producing polysaccharide-containing particles, comprising a spray-drying step of obtaining a precursor by spray-drying a solution containing a polysaccharide and a polyhydric alcohol, and a heat-treatment step of heating the precursor obtained in the spray-drying step to obtain polysaccharide-containing particles.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] The conventional technologies described above all utilize crosslinking agents, insolubilizing polysaccharide-containing particles by reacting them with the crosslinking agent. The resulting particles contain both the crosslinking agent and the crosslinked structure. In recent years, many industries, including the cosmetics industry, have demanded the use of materials that are non-toxic to ecosystems, highly biodegradable, and that reduce the amount of organic solvents used. Technologies that insolubilize water-soluble polysaccharides by crosslinking have sometimes been unacceptable due to the chemical reaction involved and the potential for degradability of the resulting particles. Furthermore, the insolubilization process sometimes requires high-temperature, long-duration heating, which can cause discoloration of the polysaccharide-containing particles.

[0005] This invention has been made in view of these circumstances, and provides a method for producing polysaccharide-containing particles using a desalting agent. [Means for solving the problem]

[0006] According to the present invention, a method for producing polysaccharide-containing particles, A method for producing polysaccharide-containing particles, comprising a spray drying step and a desalting step, In the aforementioned spray drying step, a dispersion containing polysaccharides in a salt state is spray-dried to obtain precursor polysaccharide-containing particles. The desalting step involves contacting the salted polysaccharides contained in the precursor polysaccharide-containing particles with a desalting agent, and the desalting agent is used to desalt the salted polysaccharides to obtain polysaccharide-containing particles.

[0007] Through diligent research, the inventors discovered that polysaccharide-containing particles that are poorly soluble in water and have little coloration can be obtained by a manufacturing method comprising a spray-drying step of spray-drying a dispersion containing polysaccharides in a salt state to obtain precursor polysaccharide-containing particles, and a desalting step of contacting the salt state polysaccharides with a desalting agent to desalt the salt state polysaccharides with the desalting agent to obtain polysaccharide-containing particles, thereby completing the present invention.

[0008] The following are examples of various embodiments of the present invention. The embodiments shown below can be combined with each other. [1] A method for producing polysaccharide-containing particles, comprising a spray drying step and a desalting step, wherein in the spray drying step, a dispersion containing polysaccharides in a salt state is spray-dried to obtain precursor polysaccharide-containing particles, and in the desalting step, a desalting agent is brought into contact with the polysaccharides in a salt state contained in the precursor polysaccharide-containing particles, and the polysaccharides in a salt state are desalted with the desalting agent to obtain polysaccharide-containing particles. [2] The desalting step includes a heat treatment step, in which the precursor polysaccharide-containing particles are heated while a desalting agent is in contact with the salted polysaccharide to desalt the salted polysaccharide with the desalting agent and obtain polysaccharide-containing particles. The manufacturing method according to [1]. A method for manufacturing according to [3][1], wherein the dispersion further comprises inorganic particles. A method for manufacturing according to any one of [4][1] to [3], wherein the desalting agent is a nitrogen-containing compound, a carboxylic acid, or an alcohol. A method for producing a nitrogen-containing compound as described in [5][4], wherein the nitrogen-containing compound is at least one selected from the group consisting of carbamide, amine, acid amide, and nitrogen-containing heterocyclic compound. A method for producing a product according to any one of [6][1] to [5], wherein the polysaccharide is at least one selected from the group consisting of chitosan, cellulose, and derivatives thereof. A manufacturing method according to any one of [7][1] to [6], wherein when the polysaccharide-containing particles are immersed in water, the solid color difference ΔE is 0 to 60, and the color difference ΔE is a value relative to standard white in the L*a*b* color space. A manufacturing method according to [8][2], wherein the heat treatment step is performed at a temperature of 100°C or higher and less than 200°C. [9] Precursor polysaccharide-containing particles comprising a polysaccharide in a salt state and a desalting agent capable of desalting the polysaccharide in a salt state.

[10] Polysaccharide-containing particles comprising a polysaccharide and a neutralizing agent, wherein the neutralizing agent is capable of neutralizing an acid or base that can form a salt with the polysaccharide. Polysaccharide-containing particles as described in

[11]

[10] , wherein the solubility when immersed in water at 25°C for 7 days is 50% by mass or less. Polysaccharide-containing particles as described in

[12]

[10] or

[11] , further comprising inorganic particles. [Effects of the Invention]

[0009] The present invention provides a method for producing polysaccharide-containing particles, which involves desalting polysaccharides in a salted state using a desalting agent. This mechanism allows for the production of polysaccharide-containing particles that are poorly soluble in water and have minimal coloration. Furthermore, the obtained polysaccharide-containing particles can be used in a variety of applications, taking advantage of their properties, such as external cosmetic preparations, paint additives, pharmaceutical additives, resin composition additives, film additives to impart optical or antiblocking properties, and process components for firing and polishing. They are particularly suitable for use in cosmetics. [Modes for carrying out the invention]

[0010] The present invention will be described in detail below with reference to embodiments of the present invention. The present invention is not limited in any way by these descriptions. The features of the embodiments of the present invention shown below can be combined with each other. Furthermore, each feature constitutes an invention independently.

[0011] 1. Method for producing polysaccharide-containing particles The present invention relates to a method for producing polysaccharide-containing particles, which includes a spray drying step and a desalting step, and optionally includes a heat treatment step. In the spray drying step, a dispersion containing polysaccharides in a salt state is spray-dried to obtain precursor polysaccharide-containing particles. In the desalting step, a desalting agent is brought into contact with the polysaccharides in a salt state contained in the precursor polysaccharide-containing particles, and the polysaccharides in a salt state are desalted with the desalting agent to obtain polysaccharide-containing particles.

[0012] In the manufacturing method of the present invention, a desalting agent is brought into contact with a polysaccharide in a salt state. In the manufacturing method of the present invention, the desalting agent can be added at any step as long as a state in which the desalting agent is brought into contact with the polysaccharide in a salt state can be formed during the desalting step. The desalting agent can also be added, for example, in the dispersion preparation step. In this case, in the dispersion preparation step, a dispersion containing salted polysaccharides and a desalting agent is prepared, and the dispersion is spray-dried to obtain precursor polysaccharide-containing particles containing salted polysaccharides and a desalting agent. In this case, it is preferable that the desalting step includes a heat treatment step. When a desalting agent is added to the dispersion, it is preferable to appropriately select the types of salted polysaccharides and desalting agent, and as an example, it is preferable to select a combination in which desalting does not proceed easily at room temperature. The desalting agent can also be added, for example, after obtaining precursor polysaccharide-containing particles (in this case, the precursor polysaccharide-containing particles do not need to contain the desalting agent) in a spray-drying process. In this case, the desalting agent can be added to the obtained precursor polysaccharide-containing particles by immersing them in a solution containing the desalting agent, spraying and / or coating them with a solution containing the desalting agent, or exposing them to a gas containing the desalting agent, thereby creating a state in which the desalting agent comes into contact with the salted polysaccharides. In one embodiment of the present invention, after obtaining precursor polysaccharide-containing particles in a spray drying step, a desalting agent can be brought into contact with them. In this case, a heat treatment step can be performed, or it can be omitted. In one embodiment of the present invention, even if a heat treatment step is not performed afterward, water resistance can be improved. From the viewpoint of suppressing discoloration, it is preferable not to perform a heat treatment step after contact with the desalting agent. If there is no heat treatment step, it is preferable to appropriately select the type of polysaccharide in the salt state and the type of desalting agent, and as an example, it is preferable to select a combination in which desalting proceeds at room temperature. In a manufacturing method according to one embodiment of the present invention, it is preferable to include at least one of the above-described methods for adding a desalting agent. In a manufacturing method according to one embodiment of the present invention, it is preferable to obtain precursor polysaccharide-containing particles in a spray drying step and then contact them with a desalting agent.

[0013] 1.1 Dispersion preparation process A method for producing polysaccharide-containing particles according to one embodiment of the present invention may include a dispersion preparation step. In the dispersion preparation step, a dispersion containing a polysaccharide in a salt state is prepared. The dispersion contains a polysaccharide in a salt state and may further contain a desalting agent if the desalting agent is added in the dispersion preparation step. Further, the dispersion may contain inorganic particles.

[0014] Examples of the solvent for the dispersion include water, an organic solvent, or a mixed solvent of water and an organic solvent. Among these, it is preferable to contain water, and it is more preferable to be water. Examples of water include natural water, purified water, distilled water, ion-exchanged water, pure water, etc. Among these, ion-exchanged water is preferable. Examples of the organic solvent include aliphatic monohydric alcohols such as methanol, ethanol, and isopropyl alcohol, ketones such as acetone, methyl ethyl ketone, and methyl isobutyl ketone, and aromatic compounds such as toluene and xylene. For example, a mixed solvent of water and an organic solvent may also be used. Note that the solvent may not contain an alcohol having 3 or more carbon atoms and may not contain an alcohol.

[0015] 1.1.1 Polysaccharide in a salt state The dispersion contains a polysaccharide in a salt state. The dispersion may be obtained by adding a polysaccharide in a salt state, that is, a polysaccharide salt, to a solvent, or may be obtained by adding a polysaccharide and a salt-forming agent to a solvent. The polysaccharide in a salt state may be one kind of compound. The polysaccharide in a salt state may contain two or more kinds of compounds.

[0016] Examples of polysaccharides include glucosamine-based substances and molecules containing glucose units. Examples of glucosamine-based substances include chitosan, which is β-1,4-glucosamine, and chitin, which is β-1,4-N-acetylglucosamine. Examples of molecules containing glucose units include β-glucan. Examples of β-glucan include β-1,4-glucan and β-1,3-glucan. Examples of β-1,4-glucan include cellulose, cellulose acetate, ethyl cellulose, methyl cellulose, carboxymethyl cellulose, carboxyethyl cellulose, hydroxyethyl cellulose, and hydroxypropyl methyl cellulose. Examples of β-1,3-glucan include curdlan and paramylon. Also, examples include alginic acid, which is a block polymer of β-D-mannuronic acid and α-L-guluronic acid. Furthermore, derivatives thereof can also be included. The polysaccharide is preferably at least one selected from the group consisting of chitosan, cellulose, and derivatives thereof.

[0017] Examples of polysaccharide salts include the salts of the polysaccharides described above. Examples of salt-forming agents include acids or bases that can form the polysaccharide in a salt state. As an example, when the polysaccharide is chitosan, an acid can be used as the salt-forming agent. Examples of acids include organic acids such as carboxylic acids and inorganic acids such as hydrochloric acid and sulfuric acid. Examples of carboxylic acids include the carboxylic acids listed as desalting agents described later. As another example, when the polysaccharide is carboxymethyl cellulose, a base can be used as the salt-forming agent. Examples of bases include nitrogen-containing compounds and inorganic bases such as aluminum hydroxide and potassium hydroxide. Examples of nitrogen-containing compounds include the nitrogen-containing compounds listed as desalting agents described later.

[0018] It is preferable that the polysaccharide in its salt state is soluble in water. The polysaccharide in its salt state can have higher solubility than the desalted polysaccharide contained in the polysaccharide-containing particles described later. Specifically, the polysaccharide in its salt state can have a solubility of 80% by mass or more when immersed in water at 25°C for 7 days. The solubility of the polysaccharide in its salt state when immersed in water at 25°C for 7 days may be, for example, 80, 85, 90, 95, 96, 97, 98, 99, or 100% by mass, and may be within the range of any two of the values ​​exemplified here.

[0019] 1.1.2 Desalination agent When a desalting agent is added in the dispersion preparation process, the dispersion may contain the desalting agent, and the desalting agent is not particularly limited as long as it is a compound that neutralizes the acid or base that forms a salt with polysaccharides, thereby desalting, or a compound that promotes desalting. The desalting agent may also include those that do not have a desalting function under normal temperature and atmospheric pressure conditions, but become capable of desalting when energy such as heating or light is applied. The desalting agent may be a base, an acid, or an alcohol, and may be a base, an acid, or an alcohol with 3 or more carbon atoms. Examples of desalting agents that become capable of desalting when energy such as heating or light is applied include photo(thermal) base generators and photo(thermal) acid generators, and one example is a curing agent for epoxy resins. The desalting agent may be a base if the salt forming agent is an acid, and the desalting agent may be an acid if the salt forming agent is a base. The mechanism by which alcohol functions as a desalting agent is not entirely clear, but it is presumed that one reason is that the crystal structure is selectively shaped by the addition of alcohol. The desalting agent can be a nitrogen-containing compound, a carboxylic acid, or an alcohol; it can be a nitrogen-containing compound, a carboxylic acid, or a monohydric alcohol; or it can be a nitrogen-containing compound, a carboxylic acid, or a monohydric alcohol having 3 or more carbon atoms. When the heat treatment step described later is performed, it is more preferable that the desalting agent has heat resistance that remains in the resulting polysaccharide-containing particles.

[0020] The nitrogen-containing compound can be at least one selected from the group consisting of carbamides, amines, acid amides, and nitrogen-containing heterocyclic compounds. Examples of carbamides include urea and urea derivatives. Specifically, examples include urea, methylurea, ethylurea, propylurea, butylurea, isobutylurea, 1,1-dimethylurea, 1,3-dimethylurea, 1,1-diethylurea, 1,3-diethylurea, tetramethylurea, 1,1,3,3-tetraethylurea, and 1,1,3,3-tetrabutylurea. Among these, urea and tetramethylurea are particularly preferred from the viewpoint of desalting effect. Examples of amines include compounds having an amine structure, such as alkylamines like ammonia, methylamine, ethylamine, n-propylamine, n-butylamine, n-amylamine, and n-hexylamine; alkanolamines like methanolamine, triethanolamine, diethanolamine, monoethanolamine, propanolamine, isopropanolamine, and diisopropanolamine; and polyamines like ethylenediamine, putrescine, cadaverine, hexamethylenediamine, and polyethylenediamine. Examples of acid amides include compounds having a structure formed by the dehydration condensation of ammonia or a primary or secondary amine with an oxoacid, such as niacinamide, acetanilide, acetic acid amide, ε-caprolactam, and γ-butyrolactam. Examples of nitrogen-containing heterocyclic compounds include pyridines such as pyridine, niacin, 2-methylpyridine, 3-methylpyridine, 4-methylpyridine, 2-hydroxy-4-methylpyridine, 2-hydroxy-6-methylpyridine, 2-hydroxypyridine, 3-hydroxypyridine, and 4-hydroxypyridine; pyrrolidines such as 1-methylpyrrolidine, 1-ethylpyrrolidine, 1-(2-hydroxyethyl)pyrrolidine, and 2-(2-hydroxyethyl)-1-methylpyrrolidine; and 1- Examples of suitable materials include piperidines such as methylpiperidine, 1-ethylpiperidine, 1-(2-hydroxyethyl)piperidine, 1-(hydroxymethyl)piperidine, 3-hydroxy-1-methylpiperidine, 4-hydroxy-1-methylpiperidine, and 1,4-dimethylpiperidine; piperazines such as 1-methylpiperazine and 1-ethylpiperazine; natural extracts containing nitrogen-containing heterocycles; nucleic acids such as purine bases and pyrimidine bases; and niacin is particularly preferred from the viewpoint of desalting effect. From the viewpoint of desalting effect, the nitrogen-containing compound preferably contains one or more selected from polyethylenediamine, ammonia, urea, tetramethylurea, and niacin. The desalting agent, and especially the nitrogen-containing compound, preferably has a pH of 7 or higher, for example, 7, 8, 9, 10, 11, 12, 13, or 14, and may be within the range of any two of the values ​​exemplified here. The nitrogen-containing compound is preferably strongly basic, and polyethylenediamine and ammonia are more preferred.

[0021] Examples of carboxylic acids include saturated fatty acids such as formic acid, acetic acid, propionic acid, and butyric acid; hydroxy acids such as lactic acid, malic acid, and citric acid; and dicarboxylic acids such as oxalic acid, succinic acid, and adipic acid.

[0022] Examples of alcohols include monohydric alcohols such as 1-propyl alcohol, isopropyl alcohol, and 1-butanol; dihydric alcohols such as ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, neopentyl glycol, 1,6-hexanediol, diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, polyethylene glycol, and polypropylene glycol; and trihydric or higher polyhydric alcohols such as glycerin, diglycerin, erythritol, trimethylolethane, trimethylolpropane, pentaerythritol, dipentaerythritol, and sorbitol. From the viewpoint of desalting effect, monohydric alcohols are preferred, and isopropyl alcohol is more preferred. Methanol and ethanol are undesirable because they have poor desalting effect. Since alcohols may volatilize due to the heat during spray drying and a sufficient desalting effect may not be obtained, it is preferable to obtain precursor polysaccharide-containing particles in the spray drying process and then contact them with the desalting agent. With desalting agents other than carbamide, water resistance can be improved by contacting the desalting agent with precursor polysaccharide-containing particles obtained through a spray-drying process, and the subsequent heat treatment step is optional. When using carbamide as the desalting agent, it is preferable to perform the heat treatment step. When a desalination agent is added to a dispersion and spray-dried, it is preferable that the desalination agent has a boiling point of 70°C or higher. In this case, the boiling points of the desalination agent may be, for example, 70, 80, 90, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, or 200°C, and may be within the range of any two of the values ​​exemplified here. When a desalting agent is brought into contact with precursor polysaccharide-containing particles obtained by a spray drying process, a desalting agent with low water solubility can be used. When a desalting agent is brought into contact with precursor polysaccharide-containing particles obtained by a spray drying process, polyethylenediamine, ammonia, isopropyl alcohol, aqueous solutions of alkali metal salts, aqueous solutions of alkaline earth metals, tertiary amines such as tetrahydroxypropylethylenediamine and dimethylaminoethanol, and primary amines such as 1-amino-3-undecanoxypropane are more preferable as desalting agents.

[0023] 1.1.3 Inorganic particles The dispersion may contain inorganic particles. Examples of inorganic particles include titanium dioxide, zirconium oxide, zinc oxide, cerium oxide, magnesium oxide, barium sulfate, calcium sulfate, magnesium sulfate, calcium carbonate, magnesium carbonate, talc, mica, kaolin, sericite, muscovite, synthetic mica, phlogopite, rose mica, biotite, lithium mica, silicic acid, anhydrous silicic acid, aluminum silicate, magnesium silicate, aluminum magnesium silicate, calcium silicate, barium silicate, strontium silicate, tungstate metal salts, hydroxyapatite, vermiculite, hydylite, bentonite, montmorillonite, hectorite, zeolite, dicalcium phosphate, alumina, aluminum hydroxide, boron nitride, boron nitride, silica, and the like. The inorganic particles are preferably plate-shaped or flaky, and more preferably mica. The mica may be natural or synthetic mica.

[0024] The average particle size of inorganic particles can be 5 to 100 μm, for example, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, and 100 μm, and may be within the range of any two of the values ​​exemplified here. The average particle size can be the volume-averaged diameter obtained by laser diffraction scattering. The aspect ratio of inorganic particles can be 20 to 200, for example, 20, 40, 60, 80, 100, 120, 140, 160, 180, and 200, and may be within the range of any two of the values ​​exemplified here. The aspect ratio can be the major axis / thickness of the inorganic particle.

[0025] 1.1.4 Content of each component in the dispersion The dispersion may contain 0.05 to 35% by mass of polysaccharides in salt form. The concentration of polysaccharide salts in the dispersion may be, for example, 0.05, 0.1, 0.5, 1, 5, 0, 5, 10, 15, 20, 25, 30, or 35% by mass, and may be within the range of any two of the values ​​exemplified here. When the dispersion is obtained by adding polysaccharides and a salt-forming agent to a solvent, 1 to 300 parts by mass of the salt-forming agent may be added per 100 parts by mass of polysaccharides. The content of the salt-forming agent per 100 parts by mass of polysaccharides may be, for example, 0, 50, 100, 150, 200, 250, or 300 parts by mass, and may be within the range of any two of the values ​​exemplified here.

[0026] If the dispersion contains a desalting agent, it may contain 0.1 to 10.0% by mass of the desalting agent. The concentration of the desalting agent in the dispersion is, for example, 0.1, 0.2, 0.3, 0.5, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, 5.0, 5.5, 6.0, 6.5, 7.0, 7.5, 8.0, 8.5, 9.0, 9.5, or 10.0% by mass, and may be within the range of any two of the values ​​exemplified here. Preferably, the dispersion contains 1 part by mass or more of the desalting agent per 100 parts by mass of the polysaccharide in salt state. The content of the desalting agent per 100 parts by mass of the polysaccharide in salt state in the dispersion is, for example, 1, 2, 3, 5, 10, 15, 20, 25, or 30 parts by mass, and may be within the range of any two of the values ​​exemplified here. Furthermore, the desalting agent plays a role in promoting the desalting of polysaccharides in a salty state, and from the viewpoint that it is preferable for it to remain in the polysaccharide-containing particles as a neutralizing agent thereafter, it is preferable to add an excess of the desalting agent so that it remains after the manufacturing process according to one embodiment of the present invention, or, if a heat treatment process is performed, so that it remains after the heat treatment process.

[0027] If the dispersion contains inorganic particles (e.g., mica), the concentration of inorganic particles in the dispersion can be 0.1 to 70% by mass. The concentration of inorganic particles can be, for example, 0.1, 0.5, 1, 5, 0, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 60, or 70% by mass, and may be within the range of any two of the values ​​exemplified here. Preferably, the dispersion contains 10 parts by mass or more of polysaccharides in a salt state per 100 parts by mass of inorganic particles. The content of polysaccharides in salt form relative to 100 parts by mass of inorganic particles in the dispersion is, for example, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 110, 120, 130, 140, 150, 200, 250, 300, 350, 400, 450, 500, 550, 600, 650, 700, 750, 800, 850, 900, 950, 1000, 1050, 1100, 1150, and 1200 parts by mass, and may be within the range of any two of the values ​​exemplified here. By adjusting the type and amount of inorganic particles and polysaccharides in salt form in the dispersion, the structure and physical properties of the resulting polysaccharide-containing particles can be adjusted. For example, by making the concentration of polysaccharides in the salt state in the dispersion sufficiently high, and by making the content of polysaccharides in the salt state relative to the inorganic particles sufficiently high, it is possible to obtain polysaccharide-containing particles that include inorganic particles sufficiently coated with a polysaccharide-containing coating layer. Also, as an example, especially when the inorganic particles are plate-like particles or flake-like particles such as mica, it is possible to obtain polysaccharide-containing particles that are composite particles in which a sufficient number and size of polysaccharide-containing spherical particles are attached to the surface of the inorganic particles or the coating layer. Inorganic particles sufficiently coated with a coating layer, or composite particles in which a sufficient number and size of polysaccharide-containing spherical particles are attached to the surface of the inorganic particles or the coating layer, can constitute a powder with a low average friction coefficient and a high soft-focus coefficient.

[0028] The dispersion may contain known components to the extent that it does not impair the effects of the present invention. Examples of known components include those that may be included in the precursor polysaccharide-containing particles described later.

[0029] The viscosity of the dispersion is preferably 1 Pa·s or less. By achieving such a viscosity, polysaccharide-containing particles with an appropriate shape and / or structure can be obtained. In the dispersion preparation step, treatments to adjust the viscosity and rheological properties of the dispersion may be performed as needed. For example, treatments to lower the viscosity, especially the dynamic viscosity under high shear, or treatments to impart pseudoplasticity or thixotropy can be performed. These treatments can be carried out, for example, by adding a dispersant or by reducing the molecular weight of organic materials.

[0030] The dispersion can be prepared by stirring with a known stirrer, such as a disperser mixer, homomixer, or high-pressure homogenizer.

[0031] The order of mixing in the dispersion preparation process is not particularly limited. For example, if the dispersion contains polysaccharides in a salt state and a desalting agent, the polysaccharide salt (or polysaccharides and a salt-forming agent) may be added to the solvent and mixed to prepare a dispersion containing the polysaccharides in a salt state first, and then the desalting agent may be added. By mixing in this order, the precipitation of polysaccharides can be prevented.

[0032] 1.2 Spray drying process In the spray drying process, a dispersion containing polysaccharides in a salt state is spray-dried to obtain precursor polysaccharide-containing particles. The precursor polysaccharide-containing particles according to the present invention contain polysaccharides in a salt state, may contain a desalting agent capable of desalting the polysaccharides in a salt state, and may further contain inorganic particles.

[0033] In the spray drying process, precursor polysaccharide-containing particles can be obtained by supplying the dispersion to a spray dryer adjusted to a predetermined temperature and spraying it. The spray dryer is not particularly limited as long as it is a spray dryer used in the normal production of granules. • Raw material tanks for storing dispersions, • Raw material supply pump that supplies dispersion liquid, • A nozzle (four-fluid nozzle, two-fluid nozzle, or one-fluid nozzle) or rotating disk that forms the dispersion into fine droplets, • Drying chamber for drying and granulating droplets, • A blower, filter, heater, and other equipment for supplying dried and heated air or inert gas to the drying chamber. • Collectors for recovering composite powder precursors using methods such as two-point collection, cyclone, or bag filter (these may also be heatable collectors). It can be equipped with the following: By adjusting the droplet formation conditions and drying conditions in the spray drying process, the shape, structure, and physical properties of the resulting precursor polysaccharide-containing particles can be controlled.

[0034] In the spray drying process, the outlet temperature of the spray dryer can be set to 70-250°C. The outlet temperature can be, for example, 70, 80, 90, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200, 210, 220, 230, 240, or 250°C, and may be within the range of any two of the values ​​exemplified here. If the dispersion contains a desalting agent, in the spray drying process, some of the salted polysaccharides in the resulting precursor polysaccharide-containing particles may be desalted by the desalting agent. In other words, the spray drying process can also serve as the desalination process described later. Furthermore, the spray drying process can also serve as the heat treatment process described later, for example, by adjusting the drying conditions after granulation, or by adding a heating function to the spray dryer or by providing a heating chamber that can heat and hold for a certain period of time.

[0035] 3.3 Desalination process In the desalting process, a desalting agent is brought into contact with the salted polysaccharides contained in the precursor polysaccharide-containing particles, and the salted polysaccharides are desalted by the desalting agent to obtain polysaccharide-containing particles. The desalination process may involve heating, and may include the following heat treatment steps.

[0036] Generally, methods for improving water resistance are known, such as forming a crosslinked structure using a crosslinking agent, or modifying the entire material or its surface. However, these methods have sometimes been unacceptable due to the involvement of chemical reactions and the potential for worsening the decomposability of the resulting particles. In the present invention, a desalting agent is brought into contact with a polysaccharide in a salt state during the heat treatment process. The desalting agent desalts the polysaccharide in the salt state, increasing its crystallinity and thereby improving water resistance (reducing solubility). According to the present invention, it is presumed that contact with the desalting agent promotes the desalting and / or improvement of crystallinity of the polysaccharide in a salt state, easily creating a strong and robust state in which polysaccharide molecules are more tightly hydrogen-bonded, thereby improving water resistance. According to one embodiment of the present invention, yellowing of the material due to heating can be prevented. Furthermore, compared to cases where a desalting agent is not included, water resistance can be improved with no heat treatment or with low temperature and / or short heat treatment time, thus preventing yellowing of the material.

[0037] As described above, in the manufacturing method of the present invention, the desalting agent may be added at any step as long as a state in which the desalting agent is in contact with the polysaccharide in a salt state can be formed, and it may also be added after obtaining precursor polysaccharide-containing particles in the spray drying step. A manufacturing method according to one embodiment of the present invention may include a desalting agent addition step before and / or during the heat treatment step. In this case, in the desalting agent addition step, the desalting agent can be added by, for example, immersing the obtained precursor polysaccharide-containing particles in a solution containing the desalting agent, spraying and / or coating the solution containing the desalting agent, or exposing them to a gas containing the desalting agent, thereby forming a state in which the desalting agent is in contact with the polysaccharide in a salt state. Examples of desalting agents include the desalting agents listed in the dispersion preparation step. Furthermore, when preparing a solution containing the desalting agent, the solution may contain 0.1 to 90.0% by mass of the desalting agent. The concentration of the desalting agent in the solution is, for example, 0.1, 0.2, 0.3, 0.5, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, 5.0, 5.5, 6.0, 6.5, 7.0, 7.5, 8.0, 8.5, 9.0, 9.5, 10.0, 20.0, 30.0, 40.0, 50.0, 60.0, 70.0, 80.0, or 90.0% by mass, and may be within the range of any two of the values ​​exemplified here. The amount of desalting agent to be added is preferably 10 parts by mass or more, more preferably 40 parts by mass or more, and most preferably 100 parts by mass or more, per 100 parts by mass of the salted polysaccharide contained in the precursor polysaccharide-containing particles. The upper limit is preferably 400 parts by mass or less, more preferably less than 200 parts by mass, and most preferably 180 parts by mass or less. The amount of desalting agent per 100 parts by mass of salted polysaccharides contained in precursor polysaccharide-containing particles is, for example, 1, 2, 3, 5, 10, 15, 20, 25, 30, 50, 100, 200, 300, or 400 parts by mass, and may be within the range of any two of the values ​​exemplified here. The upper limit is preferably 400 parts by mass or less, more preferably less than 200 parts by mass, and most preferably 180 parts by mass or less. Furthermore, if the desalting agent contains a base (or acid), the amount of base (or acid) in the solution containing the desalting agent that comes into contact with 100 parts by mass of salted polysaccharides contained in the precursor polysaccharide-containing particles can be 1 to 150 parts by mass, for example, 1, 2, 3, 5, 10, 15, 20, 25, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, or 150 parts by mass, and may be within the range of any two of the values ​​exemplified here.

[0038] As described above, the desalting step may include a heat treatment step, in which precursor polysaccharide-containing particles are heated while in contact with a desalting agent to desalt the polysaccharide in a salt state, thereby obtaining polysaccharide-containing particles.

[0039] In the heat treatment process, it is preferable to perform the heat treatment at a temperature of 100°C or higher and less than 200°C. The heat treatment temperature may be, for example, 100, 105, 110, 115, 120, 125, 130, 135, 140, 145, 150, 155, 160, 165, 170, 175, 180, 185, 190, 195°C, or less than 200°C, and may be within the range of any two of the values ​​exemplified here. The heat treatment time can be, for example, 1, 5, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200, 210, 220, 230, 240, 250, 260, 270, 280, 290, or 300 minutes, and may be within the range of any two of the values ​​exemplified here. For example, the heat treatment can be performed under the following condition A. A. At a temperature of 100°C or higher but less than 150°C for 20 minutes or more. The heating temperature for condition A can be 100°C or higher and less than 150°C, for example, 100, 105, 110, 115, 120, 125, 130, 135, 140, 145°C, and less than 150°C, and may be within the range of any two of the values ​​exemplified here. The heating time for condition A can be 20 minutes or more, for example, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200, 210, 220, 230, 240, 250, 260, 270, 280, 290, and 300 minutes, and may be within the range of any two of the values ​​exemplified here. As another example, the heat treatment can be carried out under the following condition B. B. 150°C or higher, but less than 200°C, for 1 minute or more, but less than 90 minutes. The heating temperature for condition B can be 150°C or higher and less than 200°C, for example, 150, 155, 160, 165, 170, 175, 180, 185, 190, 195°C, and less than 200°C, and may be within the range of any two of the values ​​exemplified here. The heating time for condition B can be 1 minute or higher and less than 90 minutes, for example, 1, 2, 3, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85 minutes, and less than 90 minutes, and may be within the range of any two of the values ​​exemplified here. Yellowing and discoloration of the precursor polysaccharide-containing particles can be prevented by heating at a low temperature for a long time or at a high temperature for a short time. Preferably, the heating conditions are such that the color difference ΔE of the solid content when the resulting polysaccharide-containing particles are immersed in water is between 0 and 60. For example, the color difference ΔE of the solid content when the resulting polysaccharide-containing particles are immersed in water is 0, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, or 60, and the temperature and time are such that they fall within the range of any two of the values ​​exemplified here.

[0040] A manufacturing method according to one embodiment of the present invention may include a washing step after the desalination step. In the washing step, excess desalination agent can be removed by dehydration and washing. The dehydration step is optional, and some desalination agent may remain after the dehydration step.

[0041] The precursor polysaccharide-containing particles and polysaccharide-containing particles according to the present invention will be described below. Precursor polysaccharide-containing particles can be obtained by spray-drying a dispersion containing polysaccharides in a salt state (and, if necessary, a desalting agent) in the aforementioned spray-drying process.

[0042] 2. Precursor polysaccharide-containing particles The precursor polysaccharide-containing particles according to the present invention contain polysaccharides in a salt state. The precursor polysaccharide-containing particles according to one embodiment of the present invention contain polysaccharides in a salt state and a desalting agent capable of desalting polysaccharides in a salt state. In the case of the precursor polysaccharide-containing particles according to one embodiment of the present invention, if a desalting agent is included, a portion of the polysaccharides in a salt state in the precursor polysaccharide-containing particles may be desalted by the desalting agent, that is, they may contain desalted polysaccharides. Examples of polysaccharides in a salt state, desalting agent, and polysaccharides include the polysaccharides in a salt state, desalting agent, and polysaccharides listed in the description of the dispersion preparation step of the method for producing polysaccharide-containing particles.

[0043] When the precursor polysaccharide-containing particles contain a desalting agent, it is preferable that the desalting agent be present in an amount of 0.1 parts by mass or more per 100 parts by mass of the total amount of polysaccharides in the salt state and polysaccharides in the precursor polysaccharide-containing particles. The content of the desalting agent per 100 parts by mass of polysaccharides in the salt state in the dispersion is, for example, 0.1, 0.2, 0.3, 0.5, 1, 2, 3, 5, 10, 15, 20, 25, or 30 parts by mass, and may be within the range of any two of the values ​​exemplified here.

[0044] The precursor polysaccharide-containing particles can be spherical particles. Spherical particles include approximately spherical particles, but are intended to be particles with a rounded shape. The maximum diameter / minimum diameter of the spherical particles is preferably 0.5 to 1.5, and more preferably 0.8 to 1.2. In addition, the spherical particles may include hemispherical (lens-like, etc.) particles or spherical shapes that are partially flattened or cut, but it is preferable that at least half of the particles have a maximum diameter / minimum diameter within the above numerical range. Furthermore, the spherical particles can be smooth with few indentations or wrinkles on the surface.

[0045] The average particle size of the spherical particles can be 10 μm or less. The average particle size can be between 0.1 and 10 μm, for example, 0.1, 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10 μm, and may be within the range of any two of the values ​​exemplified here. The average particle size of the spherical particles can be measured by SEM observation. The average particle size can be determined by measuring the particle size of each spherical particle and taking the average value.

[0046] The precursor polysaccharide-containing particles may further contain inorganic particles. Examples of inorganic particles include those listed in the description of the dispersion preparation step in the method for producing polysaccharide-containing particles.

[0047] When the precursor polysaccharide-containing particles include inorganic particles (for example, mica), it is preferable that the precursor polysaccharide-containing particles contain a total of 10 parts by mass or more of polysaccharides and polysaccharides in a salt state per 100 parts by mass of inorganic particles. The total content of polysaccharides in salt form and other polysaccharides per 100 parts by mass of inorganic particles in the dispersion is, for example, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 110, 120, 130, 140, 150, 200, 250, 300, 350, 400, 450, 500, 550, 600, 650, 700, 750, 800, 850, 900, 950, 1000, 1050, 1100, 1150, and 1200 parts by mass, and may be within the range of any two of the values ​​exemplified here.

[0048] If the precursor polysaccharide-containing particles also contain inorganic particles, the precursor polysaccharide-containing particles can be composite particles comprising inorganic particles, a coating layer, and spherical particles. Here, the coating layer can be a coating layer for the inorganic particles. The spherical particles may be attached to the inorganic particles or the coating layer covering the inorganic particles. Furthermore, the coating layer and spherical particles may contain polysaccharides in a salted state, and may also contain a desalting agent capable of desalting polysaccharides in a salted state, or may contain desalted polysaccharides.

[0049] The structure and physical properties of the resulting polysaccharide-containing particles can be adjusted by adjusting the type and amount of inorganic particles, as well as the salt-state polysaccharides and polysaccharides in the precursor polysaccharide-containing particles. For example, by making the concentration of the salt-state polysaccharides and polysaccharides in the precursor polysaccharide-containing particles sufficiently high, and by making the content of the salt-state polysaccharides and polysaccharides relative to the inorganic particles sufficiently high, precursor polysaccharide-containing particles can be obtained that include inorganic particles sufficiently coated with a coating layer containing salt-state polysaccharides and polysaccharides. These precursor polysaccharide-containing particles can be used to obtain polysaccharide-containing particles that can constitute a powder with a high soft-focus coefficient. Furthermore, as an example, particularly when the inorganic particles are plate-like particles or flake-like particles such as mica, precursor polysaccharide-containing particles that are composite particles in which a sufficient number and size of spherical precursor polysaccharide-containing particles are attached to the surface of the inorganic particles or the coating layer can be obtained. These precursor polysaccharide-containing particles can be used to obtain polysaccharide-containing particles that can constitute a powder with a low average friction coefficient and a high soft-focus coefficient.

[0050] When precursor polysaccharide-containing particles contain inorganic particles, it is preferable that at least a portion of the inorganic particles are coated with a coating layer, and that the entire inorganic particles are coated with the coating layer. As mentioned above, the coating layer may contain polysaccharides in a salt state, a desalting agent capable of desalting polysaccharides in a salt state, or desalted polysaccharides. The fact that the inorganic particles are coated with a coating layer can be confirmed by SEM observation, EDS (energy-dispersive X-ray analysis), or by redissolving the coating layer covering the inorganic particles and confirming its mass. According to the precursor polysaccharide-containing particles of the present invention, polysaccharide-containing particles containing inorganic particles coated with a polysaccharide-containing coating layer can be obtained through a heat treatment process. Since the inorganic particles are coated with a coating layer, such polysaccharide-containing particles can constitute a powder with excellent soft-focus properties.

[0051] When precursor polysaccharide-containing particles contain inorganic particles, at least one spherical particle may be attached to the inorganic particles and / or the coating layer within the precursor polysaccharide-containing particles. For example, if the inorganic particles are plate-like or flaky particles such as mica, it is preferable that at least one spherical particle is attached to both main surfaces of the inorganic particles, either directly or via the coating layer. Hereinafter, "particles attached to inorganic particles" refers to particles attached to the inorganic particles either directly or via the coating layer. The number of spherical particles attached to one inorganic particle may be, for example, 1, 2, 3, 5, 9, 10, 15, 20, 15, 30, 31, 40, 50, 60, 70, 80, 90, or 100, and may be within the range of any two of the values ​​exemplified here. The presence or absence of spherical particles attached to inorganic particles, and the number of spherical particles attached to one inorganic particle, can be confirmed by observing the polysaccharide-containing particles with a scanning electron microscope (SEM). Furthermore, it is not necessary for some of the spherical particles to be attached to the inorganic particles, and the precursor polysaccharide-containing particles containing inorganic particles according to one embodiment of the present invention may also contain spherical particles that are not attached to the inorganic particles.

[0052] The precursor polysaccharide-containing particles according to one embodiment of the present invention may contain a total of 50 parts by mass or more of salted polysaccharides, polysaccharides, salt-forming agents (and optionally inorganic particles) per 100 parts by mass of the precursor polysaccharide-containing particles, for example, 50, 60, 70, 80, 90, or 100 parts by mass, and may be within the range of any two of the values ​​exemplified herein. The precursor polysaccharide-containing particles according to one embodiment of the present invention may also consist of salted polysaccharides, polysaccharides, salt-forming agents (and optionally inorganic particles).

[0053] The precursor polysaccharide-containing particles according to one embodiment of the present invention may contain known components used in polysaccharide-containing particles, such as known components used in cosmetics, to the extent that they do not impair the effects of the present invention. Examples of known components include organic powders, oily components, surfactants, UV absorbers, humectants, anti-fading agents, antioxidants, defoamers, preservatives, fragrances, solubilizers, plasticizers, viscosity modifiers, skin beautifying ingredients (whitening agents, cell activators, skin roughness improving agents, blood circulation promoters, skin astringents, anti-seborrheic agents, etc.), vitamins, amino acids, antiperspirants, alcohols, film-forming agents, anti-inflammatory agents, cooling agents, nucleic acids, hormones, inclusion compounds, pH adjusters, chelating agents, and the like.

[0054] 3. Polysaccharide-containing particles Polysaccharide-containing particles can be obtained by contacting a desalting agent with a polysaccharide in a salt state and desalting the polysaccharide with the desalting agent. The polysaccharide-containing particles according to the present invention contain polysaccharides and a neutralizing agent. Here, the neutralizing agent is a substance that can neutralize an acid or base capable of forming a salt with polysaccharides. The neutralizing agent can be a desalting agent that is contained in the precursor polysaccharide-containing particles and remains in the polysaccharide-containing particles even after the desalting and heat treatment steps. The polysaccharide-containing particles may contain polysaccharides in a salt state that were not desalted in the desalting and heat treatment steps, but from the viewpoint of improving water resistance, it is preferable that the content of polysaccharides in a salt state is low. The amount of polysaccharides in a salt state can be confirmed by the solubility evaluation described later. The polysaccharide-containing particles may also not contain polysaccharides in a salt state. Examples of polysaccharides and polysaccharides in a salt state include the polysaccharides and polysaccharides in a salt state listed in the description of the dispersion preparation step of the method for producing polysaccharide-containing particles. Examples of neutralizing agents include the desalting agents listed in the description of the dispersion preparation step in the method for producing polysaccharide-containing particles.

[0055] Furthermore, it is preferable that the solubility of the desalted polysaccharide after immersion in water at 25°C for 7 days is less than 80% by mass. The solubility of the desalted polysaccharide after immersion in water at 25°C for 7 days may be, for example, 0, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75% by mass, or less than 80% by mass, and may be within the range of any two of the values ​​exemplified here.

[0056] The polysaccharide-containing particles preferably contain 0.01 parts by mass or more of a desalting agent per 100 parts by mass of the total polysaccharides in the polysaccharide-containing particles and polysaccharides in salt form. The content of the desalting agent per 100 parts by mass of polysaccharides in salt form in the dispersion is, for example, 0.01, 0.02, 0.03, 0.05, 0.1, 0.2, 0.3, 0.5, 1, 2, 3, 5, 10, 15, 20, 25, or 30 parts by mass, and may be within the range of any two of the values ​​exemplified here.

[0057] Polysaccharide-containing particles can be obtained by desalting polysaccharides in a salty state using a desalting agent, and their shape and average particle size can be the same as those of precursor polysaccharide-containing particles.

[0058] The polysaccharide-containing particles may also contain inorganic particles. Examples of inorganic particles include those listed in the description of the dispersion preparation step in the method for producing polysaccharide-containing particles.

[0059] When the polysaccharide-containing particles include inorganic particles (for example, mica), it is preferable that the polysaccharide-containing particles contain a total of 10 parts by mass or more of polysaccharides and polysaccharides in salt form per 100 parts by mass of inorganic particles. The total content of polysaccharides and polysaccharides in salt form per 100 parts by mass of inorganic particles in the dispersion is, for example, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 110, 120, 130, 140, 150, 200, 250, 300, 350, 400, 450, 500, 550, 600, 650, 700, 750, 800, 850, 900, 950, 1000, 1050, 1100, 1150, and 1200 parts by mass, and may be within the range of any two of the values ​​exemplified here.

[0060] When polysaccharide-containing particles also contain inorganic particles, the polysaccharide-containing particles can be composite particles comprising inorganic particles, a coating layer, and spherical particles. Here, the coating layer can be a coating on the inorganic particles. The spherical particles may be attached to the inorganic particles or the coating layer covering the inorganic particles. Furthermore, the coating layer and spherical particles may contain polysaccharides and a neutralizing agent capable of neutralizing acids or bases that can form salts with polysaccharides, and may also contain polysaccharides in a salt state.

[0061] The structure and physical properties of polysaccharide-containing particles can be adjusted by adjusting the type and amount of inorganic particles, as well as polysaccharides and polysaccharides in salt form, within the polysaccharide-containing particles. For example, by making the concentration of polysaccharides and polysaccharides in salt form in the polysaccharide-containing particles sufficiently high, and by making the content of polysaccharides and polysaccharides in salt form relative to the inorganic particles sufficiently high, polysaccharide-containing particles can be made that include inorganic particles sufficiently coated with a coating layer containing polysaccharides and polysaccharides in salt form. Such polysaccharide-containing particles can constitute a powder with a high soft-focus coefficient. Furthermore, as an example, if the inorganic particles are plate-like particles or flake-like particles such as mica, the polysaccharide-containing particles become composite particles in which a sufficient number and size of polysaccharide-containing spherical particles are attached to the surface of the inorganic particles or the coating layer. Such polysaccharide-containing particles can constitute a powder with a low average friction coefficient and a high soft-focus coefficient.

[0062] When polysaccharide-containing particles also contain inorganic particles, it is preferable that at least a portion of the inorganic particles are coated with a coating layer, and that the entire inorganic particles are coated with the coating layer. As mentioned above, the coating layer contains polysaccharides and a neutralizing agent capable of neutralizing acids or bases that can form salts with polysaccharides, and may also contain polysaccharides in a salt state. The fact that inorganic particles are coated with a coating layer can be confirmed by SEM observation, EDS (energy-dispersive X-ray analysis), or by separating precursor polysaccharide-containing particles, redissolving the coating layer that coats the inorganic particles, and confirming its mass. Because the polysaccharide-containing particles according to the present invention are coated with a coating layer, they can constitute a powder with excellent soft-focus properties.

[0063] When polysaccharide-containing particles also contain inorganic particles, at least one spherical particle may be attached to the inorganic particles and / or the coating layer within the polysaccharide-containing particles. For example, if the inorganic particles are plate-like or flaky particles such as mica, it is preferable that at least one spherical particle is attached to both main surfaces of the inorganic particles, either directly or via the coating layer. Hereinafter, "particles attached to inorganic particles" refers to particles attached to the inorganic particles directly or via the coating layer. The number of spherical particles attached to one inorganic particle may be, for example, 1, 2, 3, 5, 9, 10, 15, 20, 15, 30, 31, 40, 50, 60, 70, 80, 90, or 100, and may be within the range of any two of the values ​​exemplified here. The presence or absence of spherical particles attached to inorganic particles, and the number of spherical particles attached to one inorganic particle, can be confirmed by observing the polysaccharide-containing particles with a scanning electron microscope (SEM). Furthermore, it is not necessary for some of the spherical particles to be attached to the inorganic particles, and the polysaccharide-containing particles containing inorganic particles according to one embodiment of the present invention may also contain spherical particles that are not attached to the inorganic particles.

[0064] The polysaccharide-containing particles according to one embodiment of the present invention may contain a total of 50 parts by mass or more of polysaccharides, polysaccharides in salt form, a neutralizing agent (and inorganic particles if necessary) per 100 parts by mass of polysaccharide-containing particles, for example, 50, 60, 70, 80, 90, or 100 parts by mass, and may be within the range of any two of the values ​​exemplified herein. The polysaccharide-containing particles according to one embodiment of the present invention may also consist of polysaccharides, polysaccharides in salt form, a neutralizing agent (and inorganic particles if necessary).

[0065] Polysaccharide-containing particles according to one embodiment of the present invention may contain known components used in polysaccharide-containing particles, such as known components used in cosmetics, to the extent that they do not impair the effects of the present invention. Examples of known components include those listed as known components that precursor polysaccharide-containing particles may contain.

[0066] 3.1 Physical properties of polysaccharide-containing particles The polysaccharide-containing particles according to one embodiment of the present invention preferably have a solubility of 50% by mass or less, and more preferably 30% by mass or less, when immersed in water at 25°C for 7 days, from the viewpoint of water resistance suitable for use as a cosmetic powder. For example, these values ​​may be 0, 5, 10, 15, 20, 25, 30, 35, 40, 45, or 50% by mass, and may be within the range of any two of the values ​​exemplified here. The solubility of the composite powder when immersed in water at 25°C for 7 days can be calculated by immersing the polysaccharide-containing particles in ion-exchanged water at 25°C for 7 days, and using the following formula from the mass Ag of the polysaccharide-containing particles before immersion and the mass Bg of the residue after immersion. [Solubility (mass%)]=(AB) / A×100 The solubility of polysaccharide-containing particles can be controlled by adjusting the type and amount of polysaccharide, as well as the manufacturing conditions during the production of the polysaccharide-containing particles (the type and amount of salt-state polysaccharide and desalting agent added to the dispersion, and the heat treatment temperature and time). In this case, if the polysaccharide-containing particles also contain inorganic particles, it is more preferable that the solubility of the residue (components including polysaccharides and neutralizing agents) remaining after removing the inorganic particles from the polysaccharide-containing particles is as described above.

[0067] In one embodiment of the present invention, it is preferable that no gelation or swelling is observed when 1 g of polysaccharide-containing particles is immersed in 10 times the amount of ion-exchanged water at 25°C for 7 days. Furthermore, it is preferable that the polysaccharide-containing particles have lower solubility than the precursor polysaccharide-containing particles before the desalting process. The difference between the solubility of the polysaccharide-containing particles after immersion in 25°C water for 7 days and the solubility of the precursor polysaccharide-containing particles after immersion in 25°C water for 7 days is, for example, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95% by mass, and may be within the range of any two of the values ​​exemplified here.

[0068] In one embodiment of the present invention, polysaccharide-containing particles preferably have a solid color difference ΔE of 0 to 60 when the polysaccharide-containing particles are immersed in water. When the color difference ΔE is within the above range, yellowing and discoloration are suppressed, making them useful as external cosmetics and paint additives. ΔE can be a value relative to standard white in the L*a*b* color space. The color difference ΔE can be, for example, 0, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, or 60, and may be within the range of any two of the values ​​exemplified here. The solid color difference ΔE of polysaccharide-containing particles when immersed in water can be controlled by adjusting the type and amount of polysaccharide, as well as the manufacturing conditions during the production of the polysaccharide-containing particles (type and amount of salted polysaccharide and desalting agent blended in the dispersion, and heat treatment temperature and time), particularly the heat treatment temperature and time.

[0069] It is preferable that polysaccharide-containing particles are biodegradable. Biodegradability means that the polymer decomposes and disappears in the global environment, such as soil and seawater, and / or decomposes and disappears in living organisms. For example, it is preferable that polysaccharide-containing particles have a BOD degradation rate of 60% or more when exposed to activated sludge for 28 days, according to OECD TG301C. Also, for example, it is preferable that polysaccharide-containing particles have a degradation rate of 60% or more when buried in soil, or a relative degradation rate of 90% or more relative to cellulose, according to JIS K 6955 (ISO 17556). Also, for example, it is preferable that polysaccharide-containing particles have a relative degradation rate of 60% or more relative to cellulose when left standing in seawater and sandy sediment, according to ISO 19679. However, if the polysaccharide-containing particles contain inorganic particles, it is preferable that the biodegradability of the residue (components including polysaccharides and neutralizing agents) after removing the inorganic particles from the polysaccharide-containing particles is as described above.

[0070] Polysaccharide-containing particles according to one embodiment of the present invention, especially when inorganic particles are included, can have a soft focus coefficient (SFF) of 0.86 or higher, and can be between 0.86 and 1.40. The soft focus coefficient can be, for example, 0.86, 0.90, 0.95, 1.00, 1.05, 1.10, 1.15, 1.20, 1.25, 1.3, 1.35, or 1.40, and may be within the range of any two of the values ​​exemplified here. The soft focus coefficient can be measured by applying the polysaccharide-containing particles to a skin material such as BioSkin and using a variable-angle photometer. The light source can be fixed at 45°, and the sensor can be scanned from 0° to 180° to measure the brightness at each angle. The ratio of the brightness at two points (brightness at 65° / brightness at 135°) can be used as the soft focus coefficient. By setting the soft focus coefficient to be above the lower limit mentioned above, cosmetics with suppressed glare can be obtained. By setting the soft focus coefficient above the lower limit mentioned above, it is possible to create bright cosmetics that take advantage of the high brightness of the inorganic particles themselves, such as mica, which are extender pigments. The soft focus coefficient can be adjusted by the type and structure of the polysaccharide-containing particles. In particular, it can be adjusted by controlling the amount of the coating layer on the inorganic particles such as mica, as well as the number and size of the spherical particles.

[0071] The polysaccharide-containing particles according to one embodiment of the present invention, especially when inorganic particles are included, can have an average friction coefficient (MIU) of 0.75 or less, and can be between 0.40 and 0.75. The average friction coefficient can be, for example, 0.40, 0.45, 0.50, 0.55, 0.60, 0.65, 0.70, or 0.75, and may be within the range of any two of the values ​​exemplified here. The average friction coefficient can be determined by applying the polysaccharide-containing particles to a skin material such as BioSkin and scanning it using a friction tester, and can be specifically measured by the method described in the examples. When the average friction coefficient is above the lower limit, the cosmetic powder can be maintained in an even state after application to the skin, and a cosmetic with excellent longevity can be obtained. In addition, there is less collapse or detachment during or after molding by compression, etc., and it has excellent moldability. When the average friction coefficient is below the upper limit, a cosmetic that is smooth, does not feel sticky, and can be applied uniformly can be obtained. The average coefficient of friction can be adjusted by the type and structure of the polysaccharide-containing particles, and in particular, by controlling the number and size of spherical particles adhering to inorganic particles such as mica.

[0072] The polysaccharide-containing particles according to one embodiment of the present invention preferably have a porosity of 50% or less, for example, 0, 10, 20, 30, 40, 50%, and may be within the range of any two of the values ​​exemplified herein. The polysaccharide-containing particles according to one embodiment of the present invention may be made free of porous particles.

[0073] According to one embodiment of the present invention, polysaccharide-containing particles can be obtained that are poorly soluble in water and have little coloration by a mechanism in which polysaccharides in a salt state are desalted using a desalting agent. According to one embodiment of the present invention, polysaccharide-containing particles that do not contain crosslinking agents or crosslinking structures can be obtained. According to one embodiment of the present invention, polysaccharide-containing particles that are non-toxic to ecosystems, highly biodegradable, and reduce the amount of organic solvents used can be obtained, thus meeting the industry's need to create more environmentally friendly products. The polysaccharide-containing particles according to the present invention possess the above-mentioned properties, and are poorly soluble in water and have minimal coloration. Therefore, taking advantage of these properties, they can be used in a variety of applications, such as external cosmetic preparations, paint additives, pharmaceutical additives, resin composition additives, film additives for imparting optical or antiblocking properties, and process components for firing, polishing, etc. They are particularly suitable for use in cosmetics.

[0074] Cosmetics can include liquid, gel, and solid forms, such as foundation, face powder, eyeshadow, eyeliner, eyebrow products, blush, lipstick, and nail polish. Polysaccharide-containing particles containing inorganic particles according to one embodiment of the present invention include inorganic particles sufficiently coated with a coating layer containing polysaccharides and polysaccharides in a salt state, and further, composite particles in which a sufficient number and size of sugar-containing spherical particles are attached to the surface of the inorganic particles or the coating layer. With these polysaccharide-containing particles, it is possible to obtain a powder with a low average friction coefficient and a high soft-focus coefficient, that is, cosmetics with excellent slipperiness and soft-focus properties can be obtained. [Examples]

[0075] The present invention will be described in more detail below based on examples, but the present invention is not limited to these examples.

[0076] (Example 1) <Dispersion liquid preparation process> Chitosan (Koyo Chitosan FL-80, manufactured by Koyo Chemical Co., Ltd.) and acetic acid were added to water and mixed. Urea was further added to the resulting aqueous solution to prepare a dispersion containing a salt-state polysaccharide with a chitosan concentration of 5% by mass, an acetic acid concentration of 5% by mass, and a urea concentration of 0.5% by mass, as well as a desalting agent.

[0077] <Spray drying process> Using a two-fluid nozzle type laboratory spray dryer, the inlet temperature of the spray dryer was set to 200°C, and spray drying was performed to obtain precursor polysaccharide-containing particles 1 that included a desalting agent. When the inlet temperature of the spray dryer was set to 200°C, the outlet temperature was 70-120°C.

[0078] <Heat treatment process> The precursor polysaccharide-containing particles 1, which contained the obtained desalting agent, were heated at 120°C for 240 minutes under an atmospheric environment to obtain polysaccharide-containing particles 1.

[0079] When the shape of the obtained polysaccharide-containing particles 1 was observed using SEM, it was confirmed that spherical particles with a particle diameter of 0.1 to 10 μm were formed.

[0080] (Examples 2-18, Comparative Examples 1-8) The dispersion formulation and heat treatment conditions were as described in Tables 1 to 3, and polysaccharide-containing particles 2 to 18 were obtained.

[0081] (Example 19) <Dispersion liquid preparation process> Mica (average particle size 20 μm), chitosan (Koyo Chitosan FL-80, manufactured by Koyo Chemical Co., Ltd.), and acetic acid were added to water and mixed. Urea was further added to the resulting aqueous solution to prepare a dispersion with a mica concentration of 5% by mass, a chitosan concentration of 5% by mass, an acetic acid concentration of 5% by mass, and a urea concentration of 0.5% by mass.

[0082] Polysaccharide-containing particles 19 were obtained by performing a spray drying process and a heat treatment process, similar to Example 1.

[0083] When the shape of the obtained polysaccharide-containing particles 19 was observed by SEM, it was confirmed that the mica was coated with polysaccharide, and that 10 to 30 spherical polysaccharide-containing particles with a particle size of 0.1 to 10 μm were attached to each mica particle. Furthermore, the mean coefficient of friction (MIU), evaluated using the method described later, was found to be 0.54. Similarly, the soft focus coefficient (SFF), measured using the method described later, was found to be 1.05.

[0084] (Example 20) <Dispersion liquid preparation process> Chitosan (Koyo Chitosan FL-80, manufactured by Koyo Chemical Co., Ltd.) and acetic acid were added to water and mixed. A dispersion 20 without a desalting agent was prepared, with a chitosan concentration of 5% by mass and an acetic acid concentration of 5% by mass.

[0085] <Spray drying process> Using a two-fluid nozzle type laboratory spray dryer, the inlet temperature of the spray dryer was set to 200°C, and spray drying was performed to obtain precursor polysaccharide-containing particles 1 that included a desalting agent. When the inlet temperature of the spray dryer was set to 200°C, the outlet temperature was 70-120°C.

[0086] <Desalination process> A solution containing a desalting agent was prepared by mixing 10 g of a 30% aqueous solution of ammonia (containing 3 g of ammonia), 6 g of water, and 2 g of methanol. 5 g of the resulting precursor polysaccharide-containing particles were added to an aqueous alcohol solution prepared by mixing 5 g of water and 5 g of methanol and stirred. While maintaining dispersion through stirring, the desalting agent solution was slowly added. After adding the desalting agent solution, the mixture was stirred for 3 hours, then filtered by suction filtration using a mesh. The resulting cake was washed with 100 g of tap water and filtered by suction filtration. After thoroughly removing moisture by suction filtration, the mixture was dried in a dryer at 50°C for 5 hours to obtain polysaccharide-containing particles 20. All of the above operations were performed at room temperature (23°C).

[0087] (Examples 21-27) Polysaccharide-containing particles 21-27 were obtained in the same manner as in Example 20, except that the dispersant formulation and the type of nitrogen-containing compound were as shown in Table 4. The amounts of each desalting agent in the desalting step in Table 4 are shown relative to 5 parts by mass of the precursor polysaccharide-containing particles.

[0088] (Example 28) <Dispersion preparation process and spray drying process> Dispersion 28 was obtained in the same manner as in Example 1, except that the composition of the dispersion was as shown in Table 4. Furthermore, a spray-drying process was performed in the same manner as in Example 1 to obtain precursor polysaccharide-containing particles 28.

[0089] <Desalination process> 5 g of the obtained precursor polysaccharide-containing particles were added to an aqueous alcohol solution prepared by mixing 5 g of water and 10 g of isopropyl alcohol and stirred. While maintaining the dispersion state through stirring, the solution containing the above-mentioned desalting agent was slowly added. After adding the desalting agent solution, the mixture was stirred for 3 hours, then filtered by suction filtration using a mesh, and the resulting cake was washed with 100 g of tap water and filtered by suction filtration. After thoroughly removing the moisture by suction filtration, the mixture was dried in a dryer at 50°C for 5 hours to obtain polysaccharide-containing particles 28. All of the above operations were performed at room temperature (23°C).

[0090] <Examples 29, 30> Polysaccharide-containing particles 29 and 30 were obtained in the same manner as in Example 28, except that methanol and ethanol were used instead of isopropyl alcohol, and the type and amount of desalting agent used in the desalting process were as shown in Table 4.

[0091] The raw materials used in the production of the dispersion are listed below. Natural mica: Average particle size 20 μm, Chitosan: Manufactured by Koyo Chemical Co., Ltd., Koyo Chitosan FL-80, Deacetylation degree 75% or higher CMC-NH4 (Carboxymethylcellulose ammonium): Nichirin Chemical Industry Co., Ltd., Kikkolate NA-3L

[0092] (Evaluation of polysaccharide-containing particles) <Color difference (ΔE) of particles relative to standard white when immersed in water> The obtained polysaccharide-containing particles were immersed in deionized water, and the color of the solid content was measured in the L*a*b* color space using a color reader CR-13 (manufactured by Konica Minolta). The color difference ΔE from the reference white (L=100, a=b=0) was calculated and evaluated according to the following evaluation criteria. The results are shown in Tables 1 to 4.

[0093] <Solubility> One g of polysaccharide-containing particles was immersed in 10 times its mass of deionized water at 25°C for 7 days. The mixture was then filtered by suction using a glass fiber filter. The residue captured by the filter was dried in a dryer at 100°C for 2 hours, and the mass of the residue was calculated. Let the mass of the sample before immersion be Ag and the mass of the residue be Bg. The solubility of each sample was calculated using the following formula and evaluated according to the following evaluation criteria. The results are shown in Tables 1 to 4. [Solubility (mass%)]=(AB) / A×100 ○: 30% or less △: More than 30%, less than 50% ×: More than 50%

[0094] <State of particles when immersed in water> One g of polysaccharide-containing particles was immersed in 10 times its volume of ion-exchanged water at 25°C for 7 days, and its condition was observed. ×: A state in which polysaccharide-containing particles have absorbed and / or dissolved water, resulting in gelation. △: Polysaccharide-containing particles have precipitated in water, and the particles have absorbed at least some of the water, swollen, and increased in volume. ○: Polysaccharide-containing particles precipitate in water, and no swelling of the particles is observed.

[0095] <Average coefficient of friction (MIU)> The obtained polysaccharide-containing particles 19 were added to BioSkin (manufactured by Viewlux) at a concentration of 1 mg / cm³. 2 After application, the friction coefficient was measured using a KES friction tester at a speed of 1 mm / s with a load of 50 N, scanning 30 mm. The average value over the central 20 mm was defined as the average friction coefficient (MIU).

[0096] <Soft Focus Factor (SFF)> The obtained polysaccharide-containing particles 19 were added to BioSkin (manufactured by Viewlux) at a concentration of 10 mg / cm³. 2The composite powder was applied, and the soft focus coefficient was evaluated using a variable-angle photometer (GC-5000L, manufactured by Nippon Denshoku Industries Co., Ltd.). Specifically, the light source was fixed at a 45° position, and the sensor was scanned from 0° to 180° across the BioSkin surface coated with the composite powder to measure the luminance at each angle. The ratio of the luminances at two points (luminance at 65° / luminance at 135°) was defined as the soft focus coefficient.

[0097] [Table 1]

[0098] [Table 2]

[0099] [Table 3]

[0100] [Table 4]

Claims

1. A method for producing polysaccharide-containing particles, This process includes a spray drying step and a desalting step. In the aforementioned spray drying step, a dispersion containing polysaccharides in a salt state is spray-dried to obtain precursor polysaccharide-containing particles. In the desalting step, the salted polysaccharide is desalted with a desalting agent to obtain polysaccharide-containing particles. In the aforementioned manufacturing method, I) Add the desalting agent to the dispersion and / or, II) After obtaining the precursor polysaccharide-containing particles in the spray drying step, the desalting agent is added, and the desalting agent is brought into contact with the salted polysaccharides contained in the precursor polysaccharide-containing particles. When the polysaccharide-containing particles are immersed in water, the color difference ΔE of the solid content is 0 to 60. The aforementioned color difference ΔE is a value relative to the reference white in the L*a*b* color space, A method for producing the polysaccharide-containing particles, wherein the solubility of the particles after immersion in water at 25°C for 7 days is 50% by mass or less.

2. The manufacturing method according to Claim 1, The desalting step includes a heat treatment step, In the aforementioned heat treatment step, the precursor polysaccharide-containing particles are heated while in contact with the salted polysaccharide and the desalting agent, thereby desalting the salted polysaccharide with the desalting agent to obtain polysaccharide-containing particles.

3. A method for manufacturing according to claim 1 or claim 2, wherein the dispersion further comprises inorganic particles.

4. A manufacturing method according to claim 1 or claim 2, A method for producing the desalting agent, wherein the desalting agent is a nitrogen-containing compound, a carboxylic acid, or an alcohol.

5. A manufacturing method according to claim 4, A method for producing the nitrogen-containing compound, wherein the nitrogen-containing compound is at least one selected from the group consisting of carbamides, amines, acid amides, and nitrogen-containing heterocyclic compounds.

6. A manufacturing method according to claim 1 or claim 2, A method for producing the polysaccharide, wherein the polysaccharide is at least one selected from the group consisting of chitosan, cellulose, and derivatives thereof.

7. A manufacturing method according to claim 2, A manufacturing method comprising performing the heat treatment process at a temperature of 100°C or higher and less than 200°C.

8. A manufacturing method according to claim 1 or claim 2, In the aforementioned manufacturing method, I) When adding the desalting agent to the dispersion, The dispersion contains 1 to 30 parts by mass of the desalting agent per 100 parts by mass of the salted polysaccharide, II) After obtaining the precursor polysaccharide-containing particles in the spray drying step, if the desalting agent is added and the desalting agent is brought into contact with the salted polysaccharides contained in the precursor polysaccharide-containing particles, The desalting agent is added to the precursor polysaccharide-containing particles by immersing them in a solution containing the desalting agent, spraying and / or coating them with a solution containing the desalting agent, or exposing them to a gas containing the desalting agent. A manufacturing method wherein the amount of the desalting agent to be added is 1 to 400 parts by mass per 100 parts by mass of polysaccharides in the salt state contained in the precursor polysaccharide-containing particles.

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