JP2017082031A - Polyamide resin fine particles and method for producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide polyamide resin fine particles suitable for the application of cosmetic and coating having high oil absorption properties, and a method for producing the same.SOLUTION: The polyamide resin fine particles of the present invention are polyamide resin fine particles containing 0.0001 mass% or more and 10 mass% or less of a ketoester compound having a volume average particle size of 1-100 μm. The polyamide resin fine particles can be obtained by dissolving polyamide resin in an organic solvent containing a ketoester compound and bringing the obtained solution into contact with a poor solvent of the polyamide resin or lowering a temperature of the polyamide resin solution to precipitate the polyamide resin.SELECTED DRAWING: None

Description

  The present invention relates to polyamide resin fine particles and a method for producing the same, and more particularly to polyamide resin fine particles comprising a ketoester compound useful as a substance having a function such as a fragrance and a method for producing the same.

  The polymer fine particles are fine particles made of a polymer and generally have a diameter ranging from several tens of nm to several hundreds of μm.

  Unlike polymer molded products such as films, fibers, injection molded products, and extrusion molded products, polymer fine particles are used to improve and modify various materials by taking advantage of the large specific surface area and the fine structure of the fine particles. Yes. Major applications include cosmetic modifiers, rheology modifiers such as toner additives and paints, medical diagnostic inspection agents, additives to molded articles such as automotive materials and building materials. In particular, in recent years, it has come to be used as a raw material for additive manufacturing (3D printer), which is a technique for producing tailor-made molded products in combination with high-precision laser processing technology.

  Examples of methods for producing these polyamide resin fine particles include a method of obtaining fine particles by melting and kneading two types of polymers that are not compatible with each other and then removing the medium component (Patent Documents 1 and 2), and dissolving in a solvent such as phenol. By adding a poor solvent or lowering the temperature to precipitate particles (Patent Documents 3 to 5, Non-Patent Documents 1 and 2), and depositing fine particles while polymerizing cyclic lactam monomers in the medium And a method of spray-drying a polyamide solution (Patent Documents 6 to 9).

  However, additives with higher functionality have been demanded from various fields including cosmetics and paints, and in particular, particles containing aroma components have been demanded.

  The above-described prior art has no specific disclosure of adding a fragrance, and such particles and a method for producing the same have been desired.

JP 2007-277546 A JP 2007-231038 A JP 2002-80629 A JP 2006-169373 A JP 2005-54153 A Special table 2007-515500 gazette JP 2007-106895 A JP 2005-248180 A JP 2005-307096 A

Journal of Applied Polymer Science, Vol. 45, 173-1788 (published in 1992) Journal of Applied Polymer Science, Vol. 54, 1363-1369 (published in 1994)

  An object of the present invention is to provide polyamide resin fine particles having excellent oil absorption and hydrophilicity and having a porous property suitable for cosmetic foundations, paint thickeners, etc., and in a more preferred embodiment, the particle size distribution is narrow, An object of the present invention is to provide polyamide resin fine particles having excellent powder handling properties.

In order to solve the above problems, the present inventors have intensively studied and as a result, have reached the following invention.
(1) Polyamide resin fine particles having a volume average particle diameter of 1 to 100 μm and comprising a keto ester compound of 0.0001% by mass to 10% by mass.
(2) The polyamide resin fine particles as described above, wherein the polyamide resin is polyamide 11 or polyamide 12.
(3) The polyamide resin fine particles according to any one of the above, wherein the particle size distribution index is 1 to 3.
(4) The linseed oil absorption is 100 to 1000 mL / 100 g, any one of the above-mentioned polyamide resin fine particles.
(5) The ketoester compound is ethyl acetoacetate, methyl acetoacetate, ethyl 2-hexylacetoacetate, ethyl benzylacetoacetate, methyl levulinate, ethyl levulinate, butyl levulinate, isoamyl levulinate, methyl pyruvate, ethyl pyruvate Any one of the above-mentioned polyamide resin fine particles, which is at least one compound selected from the group consisting of methyl dihydrojasmonate, dimethyl malonate and diethyl malonate.
(6) A method for producing polyamide resin fine particles, in which a polyamide resin is dissolved in an organic solvent containing a ketoester compound, a poor solvent of the polyamide resin is brought into contact with the obtained solution, and polyamide resin fine particles are precipitated.
(7) The method for producing polyamide resin fine particles as described above, wherein the poor solvent of the polyamide resin is at least one selected from ethanol, methanol and water.
(8) A method for producing polyamide resin fine particles in which a polyamide resin is heated and dissolved in an organic solvent containing a ketoester compound, the temperature of the resulting solution is lowered, and polyamide resin fine particles are precipitated.

  Since the polyamide resin fine particles of the present invention have a porous shape and a high specific surface area, they are excellent in oil absorption and use a ketoester compound. From the characteristic, it has the characteristic that the retention performance of an aromatic component is high. From these characteristics, according to the present invention, polyamide resin fine particles suitable for applications such as cosmetics and paint additives can be obtained.

  The polyamide resin fine particles of the present invention have extremely high oil absorbency, and in a preferred form, the particle size distribution is narrow, and the fluidity and handleability are excellent. Furthermore, from these points, cosmetic materials such as foundations, lipsticks, and scrub agents for male cosmetics, gloss additives, paint additives such as matting finishes, light diffusing agents, plastic sol paste resins, powder blocking materials, powders Body fluidity improver, lubricant, rubber compounding agent, abrasive, thickener, filter agent and filter aid, gelling agent, flocculant, paint additive, oil absorbent, mold release agent, plastic film Various modifiers such as sheet slipperiness improver, antiblocking agent, surface hardness improver, toughness improver, liquid crystal display spacer, chromatography filler, cosmetic foundation substrate / additive, for microcapsules Auxiliaries, medical materials such as drug delivery systems / diagnostics, fragrance / agrochemical retention agents, chemical reaction catalysts and carriers, gas adsorbents, Mick machining sintered material, standard particles for measurement and analysis can be used particles for food industry, powder coating material, and the toner and the like for electrophotographic development.

FIG. 1 is a scanning electron micrograph in place of a drawing of polyamide 12 fine particles produced in Example 1. FIG. 2 is a scanning electron micrograph in place of a drawing of the polyamide 11 fine particles produced in Example 2. FIG. 3 is a scanning electron micrograph in place of a drawing of the polyamide 11 fine particles produced in Example 3.

  Next, the polyamide resin fine particles and the production method of the present invention will be described in detail.

  The polyamide resin fine particles of the present invention are polyamide resin fine particles having a volume average particle diameter of 1 to 100 μm and containing a keto ester compound of 0.0001 mass% to 10 mass%.

  The ketoester compound used in the present invention refers to a compound further having a carbonyl group in the molecule of the ester compound, such as α-ketoester, β-ketoester, γ-ketoester, α-diester and β-diester. Point to.

  In general, ketoester compounds are known to be aromatic components, and are particularly known to be used as perfumes.

  Specific examples of ketoester compounds include ethyl acetoacetate, methyl acetoacetate, isobutyl acetoacetate, tertbutyl acetoacetate, allyl acetoacetate, acetoacetate (2-methoxyethyl), ethyl 2-methylacetoacetate, and ethyl 2-ethylacetoacetate. , Methyl propionyl acetate, ethyl propionyl acetate, ethyl butyryl acetate, ethyl isobutyryl acetate, methyl 4,4-dimethyl-3-oxopentanoate, methyl 4,4-dimethoxy-3-oxovalerate, diethyl 4-oxopimelate, 2- Ethyl hexyl acetoacetate, ethyl benzylacetoacetate, methyl levulinate, ethyl levulinate, butyl levulinate, isoamyl levulinate, methyl pyruvate, ethyl pyruvate, methyl dihydrojasmonate, 3-methyl-2-oxobuta Diethyl esters of malonic acid such as ethyl acid, ethyl 4-acetylbutanoate, 4-acetoxy-2-butanone, dimethyl malonate and diethyl malonate, dimethyl succinate and dialkyl esters of succinic acid such as diethyl succinate, dimethyl fumarate, Dialkyl fumarate such as diethyl fumarate, dialkyl maleate such as dimethyl maleate and diethyl maleate, itaconic acid dialkyl esters such as dimethyl itaconate and diethyl itaconate, dimethyl cyclohexanedicarboxylate and diethyl cyclohexanedicarboxylate And cyclohexanedicarboxylic acid diesters.

  In addition, the ketoester compound is preferably a liquid at normal temperature from the viewpoint of ease of use in the process of producing particles described later. From this point of view, the ketoester compounds include ethyl acetoacetate, methyl acetoacetate, ethyl 2-hexylacetoacetate, ethyl benzylacetoacetate, methyl levulinate, ethyl levulinate, butyl levulinate, isoamyl levulinate, methyl pyruvate, pyruvine Ethyl acid, methyl dihydrojasmonate and dimethyl malonate and diethyl malonate are preferred, and ethyl acetoacetate, methyl acetoacetate and ethyl 2-hexylacetoacetate are more preferred.

  The polyamide constituting the polyamide resin fine particles in the present invention includes a polyamide obtained by polycondensation of a lactam having three or more members, a polymerizable aminocarboxylic acid, a dibasic acid and a diamine or a salt thereof, or a mixture thereof. It is done.

  Examples of such polyamides include polyundecamide (nylon 11), polydodecamide (nylon 12), polycaproamide (nylon 6), polyhexamethylene adipamide (nylon 66), polypentamethylene adipa. Amide (nylon 56), polytetramethylene sebacamide (nylon 410), polypentamethylene sebacamide (nylon 510), polyhexamethylene sebacamide (nylon 610), polydecamethylene sebacamide (nylon 1010), Polypentamethylene terephthalamide (nylon 5T), polyhexamethylene terephthalamide (nylon 6T), polydecamethylene terephthalamide (nylon 10T), a copolymer of 4,4′-diaminodicyclohexylmethane and dodecaic acid (for example, For example, “TROG MID (registered trademark) “CX7233, manufactured by Daicel Evonik Co., Ltd.), 3,3′-dimethyl-4,4′-diaminodicyclohexylmethane, isophthalic acid and 12-aminododecanoic acid copolymer (for example, For example, “Grillamide (registered trademark)” TR55, manufactured by Ms. Chemie Japan Co., Ltd.), 3,3′-dimethyl-4,4′-diaminodicyclohexylmethane and dodecadioic acid copolymer (for example, “Grillamide (registered trademark)” TR90, manufactured by Emschemy Japan Co., Ltd.), 3,3′-dimethyl-4,4′-diaminodicyclohexylmethane, a copolymer of isophthalic acid and 12-aminododecanoic acid, and 3, A mixture of 3'-dimethyl-4,4'-diaminodicyclohexylmethane and a copolymer of dodecadioic acid (for example, " Riruamido (registered trademark) "TR70LX, Emusukemi Japan Co., Ltd.), and the like.

  Among these polyamide resins, polyundecamide (nylon 11) and polydodecamide (nylon 12) are particularly preferable because of their solubility in ketoester compounds.

  The molecular weight and molecular weight distribution of the polyamide resin are not particularly limited as long as they are substantially soluble, but the weight average molecular weight is easy to maintain the particle structure and improves hydrolysis resistance. , Preferably it is 1,000 or more, More preferably, it is 5,000 or more, More preferably, it is 10,000 or more, Most preferably, it is 20,000 or more. The upper limit is not particularly limited, but if specified, it is 10 million or less, more preferably 1 million or less, further preferably 300,000 or less, particularly preferably 200,000 or less, and particularly preferably 100,000. Or less, and most preferably 50,000 or less.

  The weight average molecular weight herein is a weight average molecular weight in terms of polymethyl methacrylate (PMMA) measured by gel permeation chromatography (GPC) using hexafluoroisopropanol as a solvent.

  The volume average particle diameter of the polyamide resin particles in the present invention is usually 1000 μm or less, 100 μm or less according to a preferred embodiment, 70 μm or less according to a more preferred embodiment, and 50 μm or less according to a more preferred embodiment, particularly According to a preferred embodiment, it is 30 μm or less, according to a particularly preferred embodiment, it is 20 μm or less, and according to a most preferred embodiment, it is 15 μm or less. The lower limit of the volume average particle diameter is usually 50 nm or more, 100 nm or more according to a preferred embodiment, 500 nm or more according to a more preferred embodiment, 1 μm or more according to a more preferred embodiment, and a particularly preferred embodiment. According to a particularly preferable aspect, it is 3 micrometers or more, and according to the most preferable aspect, it is possible to manufacture a thing of 5 micrometers or more.

  The particle size distribution is preferably 3 or less as a particle size distribution index, 2.5 or less according to a more preferred embodiment, 2 or less according to a more preferred embodiment, and 1.8 according to a particularly preferred embodiment. According to a remarkably preferred embodiment, it is 1.5 or less, and according to a most preferred embodiment, it is possible to produce a product of 1.2 or less. The preferred lower limit of the particle size distribution is 1.

  The polyamide resin particles referred to in the present invention are porous. Therefore, it is measured using a laser diffraction / light scattering particle size distribution meter (Microtrac MT3300EXII manufactured by Nikkiso Co., Ltd.) that can be measured with higher accuracy than the volume average particle diameter calculated based on the morphology of the particles observed in the micrograph. The volume average particle diameter is defined as the volume average particle diameter of the polyamide resin particles of the present invention.

  More specifically, the volume average particle diameter of the polyamide resin fine particles is determined by a wet laser diffraction / scattering method (manufactured by Nikkiso Co., Ltd., model: Microtrac MT3300EXII), using a dispersion medium for measurement as water and a refractive index of the substance of 1 .53, the refractive index of the dispersion medium is set to 1.333, and the volume average particle diameter is measured with a polyamide resin fine particle dispersion in which polyamide resin fine particles are predispersed in ion-exchanged water. The particle size distribution index representing the particle size distribution is a value obtained by dividing the volume average particle size measured by the particle size distribution meter by the number average particle size.

  The polyamide resin particles of the present invention are characterized by containing the ketoester compound. As described above, the ketoester compound is a chemical substance having a functionality such as a fragrance, so far, polyamide resin particles containing the ketoester compound have not been known. The polyamide resin particles of the present invention are useful compared to conventional polyamide resin particles as highly functional polymer fine particles having a function of having an aroma.

  The content of the ketoester contained in the polyamide resin particles in the present invention is preferably an amount that functions as an aroma component, and although it depends on the environment in which the polyamide resin particles are used, it is 0 with respect to the mass of the polyamide resin particles. 0.001% by mass or more, preferably 0.001% by mass or more, more preferably 0.01% by mass or more, still more preferably 0.1% by mass or more, and particularly preferably 0.2% by mass. % Or more. The upper limit is generally 10% by mass or less, preferably 5% by mass or less, more preferably 3% by mass or less, particularly preferably 2% by mass or less, and particularly preferably 1% by mass. % Or less.

  The content of the ketoester compound in the polyamide resin particles can be confirmed using a gas chromatography method.

  The polyamide resin fine particles comprising the ketoester compound of the present invention are different from known microcapsule type resin particles, that is, having a form in which a liquid substance is coated with a polymer, and the ketoester compound is composed of polyamide resin particles. This is considered to be a solid solution in the amorphous phase.

  A more preferable form of the polyamide resin fine particles of the present invention is that it is porous. The polyamide particles obtained by the production method described later have a specific surface area larger than that of conventionally known polyamide particles because a state in which polymer crystalline structures are gathered is formed. In some cases, a scaly polymer crystal structure may be observed. As a result, the amount of linseed oil absorption, which is an index representing lipophilicity, increases, and a material that is highly practical in the cosmetics and paint fields is created.

  The linseed oil absorption of the polyamide resin fine particles of the present invention is preferably 100 ml / 100 g or more, more preferably 150 ml / 100 g or more, further preferably 200 ml / 100 g or more, particularly preferably 300 ml / 100 g or more, Remarkably preferably 400 ml / 100 g or more, most preferably 500 ml / 100 g or more. Further, the higher the oil absorption, the better. The upper limit is not particularly defined, but is actually 1000 ml / 100 g. Here, the amount of linseed oil absorbed is a value measured by Japanese Industrial Standard (JIS standard) JIS K5101-13-1: 2004 “Pigment Test Method Purified Sesame Oil Method”.

  If the oil absorption of linseed oil is in this range, the oil absorption is high, and the retention performance of the ketoester compound as an aroma component is improved, and it can be suitably used as an additive for cosmetics and paints.

  The shape of the polyamide resin fine particles in the present invention is preferably close to a true sphere.

  The sphericity of the polyamide resin fine particles used in the present invention is preferably 60 or more, more preferably 70 or more, still more preferably 80 or more, and particularly preferably 90 or more.

  When the sphericity is in the above range, the texture such as slipperiness is improved, and the viscosity can be easily controlled when added to a paint or the like.

  The sphericity is calculated according to the following formula (1) from the average of 30 randomly selected particles by observing the particles with a scanning electron microscope, measuring the short diameter and the long diameter.

  Here, n represents the number of measurements, and the number is 30.

  As a method for producing the polyamide resin fine particles of the present invention, the present inventors have described that “the polyamide resin is dissolved in an organic solvent containing a ketoester compound, and a poor solvent of the polyamide resin is brought into contact with the obtained solution to obtain polyamide resin fine particles. The manufacturing method of the polyamide resin microparticles | fine-particles which precipitate is disclosed.

  In the above, whether the polyamide resin is dissolved or not is whether or not it dissolves more than 0.001% by mass in the organic solvent containing the ketoester compound at the temperature at which the present invention is carried out, that is, the temperature at which the polyamide resin is dissolved. Determine with.

  The organic solvent in the present invention is preferably a polar solvent, an ether solvent, a β-diketone compound, a keto ester compound, or the like from the viewpoint that porous particles are easily obtained.

  In the case where the polyamide resin is polycaproamide (polyamide 6), the technology is disclosed in Patent Document 3, but in recent years, particles with higher porosity have been demanded. In order to obtain particles with higher porosity, it is necessary to balance the particle precipitation process and the polymer crystallization process, and therefore the selection of the solvent is important. When a solvent with too high solubility is used, the solvent remains inside the fine particles after the fine particles are precipitated, and fusion between particles is likely to occur during solid-liquid separation such as filtration. It tends to grow. However, the use of a polar solvent, an ether solvent, a β-diketone compound, or a ketoester compound is extremely advantageous because fusion is unlikely to occur and particles having a narrow particle size distribution and easy to handle can be obtained.

  Specifically, polar solvents other than keto ester compounds as organic solvents include N-methylpyrrolidone, dimethyl sulfoxide, N, N-dimethylformamide, N, N-dimethylacetamide, propylene carbonate, trimethyl phosphoric acid, 1,3 -Dimethyl-2-imidazolidinone, sulfolane and the like.

  Examples of ether solvents include aliphatic chain ethers such as dimethyl ether, diethyl ether, dipropyl ether, diisopropyl ether, dibutyl ether, dipentyl ether, dihexyl ether, dioctyl ether, diisoamyl ether, tert-amyl methyl ether, and tert-butyl. Ethyl ether, butyl methyl ether, butyl ethyl ether, 1-methoxyethane (monoglyme), 1-ethoxyethane, 1,2-dimethoxyethane (diglyme), ethylene glycol diethyl ether, 2-methoxyethyl ether, di (ethylene glycol) Examples are diethyl ether, di (ethylene glycol) dibutyl ether and triethylene glycol dimethyl ether.

  Examples of the aliphatic cyclic ether include tetrahydrofuran, 2-methyltetrahydrofuran, 2,5-dimethyltetrahydrofuran, 2,2,5,5-tetramethylhydrofuran, 2,3-dihydrofuran, 2,5-dihydrofuran, Tetrahydropyran, 3-methyltetrahydropyran, 1,3-dioxolane, 2-methyl-1,3-dioxolane, 2,2-dimethyl-1,3-dioxolane, 4-methyl-1,3-dioxolane, 2-n -Butyl-1,3-dioxolane, 2,2-di-n-propyl-1,3-dioxolane, 2-ethyl-2-methyl-1,3-dioxolane, 2,2-di-n-propyl-4 -Methyl-1,3-dioxolane, 2,2-diisopropyl-4-methyl-1,3-dioxolane, 2-n-butyl-4-methyl 1,3-dioxolane, 2-n-propyl-4-methyl-1,3-dioxolane, 2-methyl-2-isobutyl-4-methyl-1,3-dioxolane, 2-n-butyl-4-ethyl- 1,3-dioxolane, 2,2-di-n-propyl-4-methyl-1,3-dioxolane, 1,3-dioxane, 4-methyl-1,3-dioxane, 2-n-butyl-4- Examples include methyl-1,3-dioxane, 1,4-dioxane, 2-n-propyl-1,3-dioxepane and 1,3,5-trioxane.

  Examples of the aromatic ether include anisole, phenetole (ethylphenol), diphenyl ether, 3-phenoxytoluene, p-tolyl ether, 1,3-diphenoxybenzene, 1,2-diphenoxyethane, and the like.

  Of these, dipropyl ether, diisopropyl ether, dibutyl ether, 1-ethoxyethane, 1,2-dimethoxy are taken into consideration from the viewpoint of industrial ease of use, economical viewpoint, and easy production of porous particles. Ethane (diglyme), ethylene glycol diethyl ether, 2-methoxyethyl ether, di (ethylene glycol) diethyl ether, tetrahydrofuran, 2-methyltetrahydrofuran, tetrahydropyran, 1,3-dioxolane, 2-methyl-1,3-dioxolane, 1,4-dioxane and anisole are preferred, more preferably 1-ethoxyethane, 1,2-dimethoxyethane (diglyme), ethylene glycol diethyl ether, 2-methoxyethyl ether, di (ethylene glycol) diethyl. Ether, tetrahydrofuran, 2-methyltetrahydrofuran, tetrahydropyran, 1,3-dioxolane, 2-methyl-1,3-dioxolane, 1,4-dioxane, more preferably tetrahydrofuran, 2-methyltetrahydrofuran, tetrahydropyran, 1,3-dioxolane, 2-methyl-1,3-dioxolane and 1,4-dioxane, particularly preferably tetrahydrofuran, tetrahydropyran and 1,3-dioxolane.

  Examples of the β-diketone compound include 2,4-pentanedione, 3-methyl-2,4-pentanedione, 3-ethyl-2,4-pentanedione, 3-chloro-2,4-pentanedione, , 1,1-trifluoro-2,4-pentanedione, 1,1,1,5,5,5-hexafluoro-2,4-pentanedione, 2,2,6,6-tetramethyl-3, 5-heptanedione, 2-acetylcyclohexanone, 1,3-cyclopentanedione, 2-methyl-1,3-cyclopentanedione, 1,3-cyclohexanedione, 2-methyl-1,3-cyclohexanedione, 5- Methyl-1,3-cyclohexanedione, 5,5-dimethyl-1,3-cyclohexanedione, 1-benzoylacetone, dibenzoylmethane, 1- (2-hydroxyphenol Le) -3-phenyl-1,3-propanediol and 4,4,4-trifluoro-1-phenyl-1,3-butanedione, and the like.

  The ketoester compound contained in the organic solvent is as described above. The keto ester compound is preferably a liquid at the temperature at which the particles are formed, and a liquid keto ester compound is particularly preferably used at a temperature of 25 ° C. By doing in this way, ketoester compound itself can be used as an organic solvent. Examples of such ketoester compounds include ethyl acetoacetate, methyl acetoacetate, isobutyl acetoacetate, methyl pyruvate, ethyl pyruvate, ethyl 4-acetylbutanoate, 4-acetoxy-2-butanone, methyl levulinate, levulin Examples include ethyl acid and dimethyl maleate and diethyl maleate.

  Each of the organic solvents other than the ketoester compound and the ketoester compound can contain a plurality of types. Moreover, an organic solvent can be comprised only with a ketoester compound.

  The content of the ketoester compound in the organic solvent is preferably 0.0001% by mass or more, more preferably 0.001% by mass or more, and still more preferably 0.01% by mass or more as a preferable content. . From the standpoint of retaining the aroma component, it is particularly preferably 0.1% by mass or more, and particularly preferably 1% by mass or more. Further, the upper limit as the content is preferably 90% by mass or more, more preferably 95% by mass or more, and particularly preferably 100% by mass.

  From the viewpoint of obtaining particles having a relatively small particle size and a small particle size distribution, the organic solvent is preferably composed only of a ketoester, or one other organic solvent. Further, since the types of contents are reduced, there is a feature that the separation process at the time of recycling the used solvent is simplified.

  In the present invention, the poor solvent for the polyamide resin brought into contact with the emulsion refers to a solvent that does not dissolve the polyamide resin. The fact that the polyamide resin is not dissolved means that the solubility of the polyamide resin in the poor solvent is 0.001% by mass or less, more preferably 0.0005% by mass or less, more preferably 0 at the temperature at which the poor solvent is contacted. 0.0001% by mass or less.

  In one method for producing the polyamide resin fine particles of the present invention, a poor solvent for the polyamide resin is used. The poor solvent is preferably a solvent that is uniformly mixed with a solvent for dissolving the polyamide resin. Thereby, the polyamide resin fine particles can be efficiently precipitated.

  The poor solvent used in the present invention varies depending on the type of polyamide resin used and the types of both the polyamide resin used and the polymer different from the polyamide resin. Specific examples of the poor solvent include pentane, hexane, heptane, octane, nonane, n-decane, n-dodecane, n-tridecane, cyclohexane, cyclopentane and other aliphatic hydrocarbon solvents, benzene, toluene, Examples thereof include aromatic hydrocarbon solvents such as xylene, alcohol solvents such as methanol, ethanol, 1-propanol and 2-propanol, and a solvent selected from at least one of water.

  The poor solvent is preferably an aromatic hydrocarbon solvent, an aliphatic hydrocarbon solvent, an alcohol solvent and water from the viewpoint of efficiently precipitating the polyamide resin, and more preferably an alcohol solvent and water. Particularly preferred are ethanol, methanol and water.

  In the present invention, by appropriately selecting and combining an organic solvent for dissolving the polyamide resin and a poor solvent for the polyamide resin, the polyamide resin can be efficiently precipitated to obtain polymer fine particles.

  Further, as another method for forming the polyamide resin fine particles in the present invention, the polyamide resin is heated and dissolved in an organic solvent containing a ketoester compound, and the temperature of the resulting solution is lowered, whereby the polyamide resin is efficiently obtained. Similar fine particles can also be formed by precipitation to obtain polymer fine particles.

  In order to make fine particles, the steps of dissolving the polyamide resin and precipitating the fine particles can be performed in an ordinary reaction vessel.

  In the present invention, from the viewpoint of industrial feasibility, the lower limit of the temperature at which the polyamide resin dissolution step and the fine particle precipitation step are performed is −50 ° C., preferably −20 ° C., more preferably 0 ° C. Further, it is preferably 10 ° C., particularly preferably 20 ° C., particularly preferably 30 ° C., and most preferably 40 ° C. The upper limit is preferably 300 ° C., more preferably 260 ° C., further preferably 230 ° C., particularly preferably 200 ° C., particularly preferably 190 ° C., and most preferably 180 ° C. It is.

  In the present invention, the concentration of the polyamide resin in the polyamide resin solution at the time of producing the polyamide resin fine particles is premised on being within a possible range that can be dissolved in the organic solvent containing the ketoester compound. Preferably it is more than 0.001% by mass, more preferably more than 0.005% by mass, still more preferably more than 0.01% by mass, and particularly preferably more than 0.5% by mass. Further, the upper limit is preferably less than 50% by mass, more preferably less than 30% by mass, still more preferably less than 20% by mass, and particularly preferably less than 10% by mass.

  The pressure in the step of dissolving the polyamide resin and depositing the fine particles is in the range of normal pressure to 10 atm from the viewpoint of industrial feasibility. A preferred lower limit is 1 atmosphere. A preferable upper limit of the pressure is 5 atm, more preferably 3 atm, and further preferably 2 atm.

  Moreover, it is preferable to use an inert gas for the reaction tank. Specifically, nitrogen, helium, argon and carbon dioxide are preferable, and nitrogen and argon are more preferable.

  The dissolution of the polyamide resin is preferably carried out with stirring. In the case of stirring with a stirring blade, although depending on the shape of the stirring blade, the stirring speed is preferably 50 rpm to 1,200 rpm, more preferably 100 rpm to 1,000 rpm, further preferably 200 rpm to 800 rpm, Particularly preferred is 300 rpm to 600 rpm.

  Specific examples of the stirring blade include a propeller type, paddle type, flat paddle type, turbine type, double cone type, single cone type, single ribbon type, double ribbon type, screw type and helical ribbon type. As long as a sufficient shearing force can be applied to the system, it is not limited to these. Moreover, in order to perform efficient stirring, a baffle plate etc. can be installed in a tank.

  The polyamide resin solution thus obtained is subsequently subjected to a step of depositing fine particles.

  In order to obtain polyamide resin fine particles, a poor solvent for the polyamide resin is brought into contact with the polyamide resin solution produced in the above-described step to precipitate the fine particles.

  When the poor solvent for the polyamide resin is brought into contact with the polyamide resin solution, it is preferably carried out while stirring. In the case of stirring with a stirring blade, although depending on the shape of the stirring blade, the stirring speed is preferably 50 rpm to 1,200 rpm, more preferably 100 rpm to 1,000 rpm, further preferably 200 rpm to 800 rpm, Particularly preferred is 300 rpm to 600 rpm.

  When a poor solvent is used when the polyamide resin fine particles are precipitated, the method of contacting with the polyamide resin solution may be a method of putting the polyamide resin solution in the poor solvent or a method of putting the poor solvent in the polyamide resin solution. A method of adding a poor solvent to the resin solution is preferably used.

  At this time, the method for introducing the poor solvent is not particularly limited as long as the polymer fine particles produced in the present invention can be obtained. Either the continuous addition method or the batch addition method may be used, but the polyamide resin fine particles are aggregated when the poor solvent is added. -It is preferable to use a continuous addition method in order to prevent fusion and coalescence and an increase in particle size distribution or formation of a mass exceeding 1000 μm.

  The continuous addition method in the present invention refers to a method in which the poor solvent to be added is added a plurality of times or continuously within a predetermined time. The batch addition method refers to a method in which a poor solvent is added at once in a short time. The short time here is less than 1 minute.

  The time for adding the poor solvent is 1 minute or more, preferably 5 minutes or more, more preferably 10 minutes or more, still more preferably 20 minutes or more, particularly preferably 30 minutes or more, and extremely preferably. Is one hour or more. The upper limit is not particularly limited, but is within 50 hours, preferably within 20 hours, more preferably within 10 hours, and particularly preferably within 5 hours.

  If it is carried out in a time shorter than this range, the particle size distribution may be increased or a lump may be generated due to aggregation, fusion, and coalescence of the polyamide resin fine particles. Moreover, when it implements in the time longer than this, when industrial implementation is considered, it is unrealistic.

  By carrying out within this time range, when the polyamide resin solution is converted into polymer fine particles, aggregation between the fine particles can be suppressed, and polymer fine particles having a small particle size distribution can be obtained.

  The amount of the poor solvent to be added may be an amount sufficient for precipitation of fine particles, and the lower limit is 0.1 parts by mass or more, preferably 0.2 parts per 1 part by mass of the total mass of the polyamide resin solution. It is at least part by mass, more preferably at least 0.3 part by mass, particularly preferably at least 0.5 part by mass. The upper limit is not particularly limited, but is preferably 10 parts by mass or less, more preferably 5 parts by mass or less, still more preferably 3 parts by mass or less, particularly preferably 2 parts by mass or less, and extremely preferably. Is 1 part by mass or less.

  The contact time between the poor solvent and the polyamide resin solution may be a sufficient time for the fine particles to precipitate, but in order to cause sufficient precipitation and to obtain efficient productivity, the poor solvent is preferably used. It is 1 minute or more after completion of the addition, more preferably 5 minutes or more, further preferably 10 minutes or more, particularly preferably 20 minutes or more, and extremely preferably 30 minutes or more. The upper limit is not particularly limited, but is preferably 50 hours or less, more preferably 10 hours or less, further preferably 5 hours or less, particularly preferably 4 hours or less, and particularly preferably 3 hours or less. It is. At this time, in order to promote precipitation of polyamide resin fine particles, stirring may be stopped and the mixture may be left standing. By doing so, aggregation between fine particles can be suppressed, and polymer fine particles having a small particle size distribution can be obtained.

  The liquid in which the polymer fine particles thus prepared are dispersed is subjected to solid-liquid separation by a generally known method such as filtration, vacuum filtration, pressure filtration, centrifugal separation, centrifugal filtration, spray drying, etc. Can be obtained.

  The polymer fine particles separated by solid-liquid separation are washed with a solvent or the like as necessary to remove attached or contained impurities, etc., and are purified.

  In the production method of the present invention, it is possible to recycle by reusing the solvent separated in the solid-liquid separation step performed when obtaining the fine particle powder.

  The solvent obtained by solid-liquid separation is a mixture of an organic solvent containing a ketoester compound and a poor solvent. By removing the poor solvent from this solvent, it can be reused as a solvent for forming an emulsion.

  The method for removing the poor solvent is usually performed by a known method, and specific examples include simple distillation, vacuum distillation, precision distillation, thin-film distillation, extraction, and membrane separation. Distillation and precision distillation are preferably used.

  When performing distillation operations such as simple distillation and vacuum distillation, as in the case of polymer fine particle production, the system is heated, and there is a possibility of promoting thermal decomposition of polyamide resin and organic solvent. It is preferably carried out in a state, more preferably in an inert atmosphere. Specifically, it is particularly preferable to carry out under nitrogen, helium, argon and carbon dioxide conditions. In addition, a phenolic compound can be added again as an antioxidant.

  When recycling the organic solvent containing the used ketoester compound, it is preferable to remove the poor solvent as much as possible. Specifically, the residual amount of the poor solvent is preferably 10% by mass or less, more preferably 5% by mass or less, still more preferably 3% by mass or less, with respect to the organic solvent containing the keto ester compound to be recycled. Especially preferably, it is 1 mass% or less. When exceeding this range, the particle size distribution of the fine particles becomes large or the particles aggregate.

  The amount of the poor solvent in the solvent containing the ketoester compound used for recycling can be measured by a generally known method, and can be measured by a gas chromatography method, a Karl Fischer method, or the like.

  In the operation of removing the poor solvent, in reality, the ketoester compound and the organic solvent other than the ketoester compound may be lost. Therefore, it is preferable to appropriately adjust the initial composition ratio.

  Thus, since the polyamide resin fine particles prepared by the method of the present invention can obtain particles having a small particle size distribution, the texture and feel are greatly improved compared to the polyamide resin fine particles obtained by the conventional method. Also, it has good fluidity when added with paint.

  From these facts, the polyamide resin fine particles obtained by the present invention can be used extremely usefully and practically in various industrial applications.

  Specific examples of usages include the following.

  Specifically, facial cleansers, sunscreen agents, cleansing agents, lotions, emulsions, serums, creams, cold creams, after shaving lotions, shaving soaps, oil blotting papers, matifant agents and other skin care product additives, foundations Cosmetics such as, Ooiro, Water Oshii, Mascara, Face Powder, Virgin, Eyebrow, Mascara, Eyeline, Eye Shadow, Eye Shadow Base, Nose Shadow, Lipstick, Gloss, Hobe, Ogre, Manicure, Top Coat, etc. Additives for hair care products such as its modifier, shampoo, dry shampoo, conditioner, rinse, rinse-in shampoo, treatment, hair tonic, hair styling, hair oil, pomade, hair coloring agent. Perfume, eau de cologne, deodorant, baby powder, toothpaste, mouthwash, lip balm, soap and other amenity product additives, toner additives, paint and other rheology modifiers, medical diagnostic tests, automotive materials, construction Mechanical property improvers for molded products such as materials, mechanical property improvers such as films and fibers, raw materials for resin molded products such as rapid prototyping and rapid manufacturing, flash molding materials, paste resins for plastic sol, powder Blocking materials, powder fluidity improvers, lubricants, rubber compounding agents, abrasives, thickeners, filter agents and filter aids, gelling agents, flocculants, paint additives, oil absorbing agents, mold release agents , Plastic film / sheet slipperiness improver, antiblocking agent, gloss control agent, matte finish agent, light diffusing agent, high surface hardness Various modifiers such as upper agents and toughness improvers, spacers for liquid crystal display devices, chromatographic fillers, base materials and additives for cosmetic foundations, auxiliary agents for microcapsules, drug delivery systems and diagnostic agents Materials, perfume and pesticide retention agents, catalysts for chemical reactions and their supports, gas adsorbents, sintered materials for ceramic processing, standard particles for measurement and analysis, particles for the food industry, powder coating materials, Further, it can be used for toner for electrophotographic development.

  In addition, the polyamide resin fine particles of the present invention can use raw materials derived from non-fossil raw materials and have properties as environmentally-friendly materials, so there is a possibility of replacing conventionally used polymer fine particles. .

  Specific examples of the resin molded body, film, fiber, etc. include, for example, electrical equipment housings, OA equipment housings, various covers, various gears, various cases, sensors, LED lamps, connectors, sockets, resistors, Relay case, switch, coil bobbin, condenser, variable capacitor case, optical pickup, oscillator, various terminal boards, transformer, plug, printed wiring board, tuner, speaker, microphone, headphones, small motor, magnetic head base, power module, housing Electrical / electronic parts such as semiconductors, LCDs, motor brush holders, parabolic antennas, computer-related parts; VTR parts, TV parts, irons, hair dryers, rice cooker parts, microwave oven parts, acoustic parts, audio equipments Audio equipment parts such as o-laser disk (registered trademark) / compact disk, lighting parts, refrigerator parts, air conditioner parts, typewriter parts, word processor parts, home appliances, office computer parts, office computer parts, telephones Related parts, facsimile-related parts, copier-related parts, cleaning jigs, oil-less bearings, stern bearings, underwater bearings and other bearings, motor-related parts such as motor parts, lighters, typewriters, microscopes, binoculars , Optical equipment such as cameras and watches, precision machinery related parts; alternator terminals, alternator connectors, IC regulators, various valves such as exhaust gas valves, fuel-related / exhaust / intake system pipes, air intake nozzle snorkel, intake Ma Hold, fuel pump, engine coolant joint, carburetor main body, carburetor spacer, exhaust gas sensor, coolant sensor, oil temperature sensor, brake pad wear sensor, throttle position sensor, crankshaft position sensor, air flow meter, thermostat for air conditioner Base, heating hot air flow control valve, brush holder for radiator motor, water pump impeller, turbine vane, wiper motor related parts, dust distributor, starter switch, starter relay, transmission wire harness, window washer nozzle, air conditioner panel switch board , Coil for fuel related solenoid valve, connector for fuse, horn terminal, electrical equipment Examples include a component insulating plate, a step motor rotor, a lamp socket, a lamp reflector, a lamp housing, a brake piston, a solenoid bobbin, an engine oil filter, and an ignition device case. In addition, because of its excellent transparency and heat resistance, it is used as a component for optical recording / communications, such as imaging equipment, such as cameras, VTRs, projection TVs, viewfinders, filters, prisms, and Fresnel lenses. Various optical disk (CD, DVD, etc.) substrates, various disk substrate protective films, optical disk player pickup lenses, optical fibers, optical switches, optical connectors, and other information equipment-related components such as liquid crystal displays, flat panel displays, plasma display light guide plates, Fresnel Lens, polarizing plate, polarizing plate protective film, retardation film, light diffusion film, viewing angle widening film, reflective film, antireflection film, antiglare film, brightness enhancement film, prism sheet, pickup lens, touch panel For parts related to transportation equipment such as light guide films and covers, such as tail lamp lenses, head lamp lenses, inner lenses, amber caps, reflectors, extensions, side mirrors, rearview mirrors, side visors, instrument needles, instrument covers, and window glass As medical equipment-related parts such as representative glazing, eyeglass lenses, eyeglass frames, contact lenses, endoscopes, optical cells for analysis, etc., as building material-related parts, such as lighting windows, road translucent plates, lighting covers, signboards, transparent The present invention can also be applied to light-proof sound insulation walls and bathtub materials, and is extremely useful for these various applications.

  Next, the polyamide resin fine particles of the present invention and the production method thereof will be described in detail based on examples, but the present invention is not limited thereto.

(1) Volume average particle size and particle size distribution measuring method:
The volume average particle size and the particle size distribution index of the polyamide resin fine particles referred to in the present invention were measured using a Microtrac MT3300EXII manufactured by Nikkiso Co., Ltd. Is. The particle size distribution index was a numerical value obtained by dividing the measured volume average particle size by the number average particle size. The measurement conditions are as follows.
-Equipment used: Nikkiso Co., Ltd., Microtrac MT3300EXII
Company analysis software DMS Ver. 11.0.0-246K
Measurement dispersion medium: ion exchange water (electric conductivity is 0.05 μS / cm)
Solvent refractive index: 1.333
-Measurement time: 10 seconds-Number of measurements: 1-Particle refractive index: 1.53
-Permeability: Transmission / Shape: Non-spherical.

(2) Molecular weight measurement of polyamide resin The weight average molecular weight was calculated by comparing with a calibration curve with polymethyl methacrylate using a gel permeation chromatography method.
Apparatus: LC system manufactured by Waters Co., Ltd. Column: HFIP-806M x 2 manufactured by Showa Denko KK Mobile phase: sodium trifluoroacetate 10 mmol / L hexafluoroisopropanol solution Flow rate: 1.0 ml / min
-Detection: differential refractometer-Column temperature: 30 ° C.

(3) Measurement of linseed oil absorption:
In evaluating oil absorption, which is an index of the porosity of the polyamide resin fine particles, Japanese Industrial Standard (JIS Standard) JIS K5101-13-1: 2004 “Pigment Test Method Purified Sesame Oil Method” was used. About 100 mg of polyamide resin fine particles were precisely weighed on a watch glass, refined linseed oil (manufactured by Kanto Chemical Co., Inc.) was gradually added dropwise with a burette, and kneaded with a palette knife. The dropping and kneading were repeated until a sample lump was formed, and the point at which the paste became a smooth hardness was taken as the end point. The amount of oil absorption (ml / 100 g) was calculated from the amount of refined linseed oil used for the dropwise addition.

(4) Evaluation of ketoester compound content in polyamide resin fine particles:
An absolute calibration curve method by gas chromatography was used to evaluate the ketoester compound content in the polyamide resin fine particles.
-Equipment: GC7890B manufactured by Agilent Technologies
・ Column: DB-WAX manufactured by Agilent Technologies
・ Carrier gas: He
Detection: FID method.

(Example 1) <Method for producing polyamide 12 fine particles using ethyl acetoacetate solvent>
In a 200 ml 4-neck separable flask, 0.05 g of polyamide 12 (“Amilan” CM5051F manufactured by Toray Industries, Inc.) as a polyamide resin and 99.95 g of ketoester compound ethyl acetoacetate as a constituent material of an organic solvent are added. The mixture was heated to a temperature of 180 ° C. and stirred until the polymer was completely dissolved. Thereafter, the temperature of the system was lowered to 60 ° C. while stirring was continued. Subsequently, 50 g of ethanol as a poor solvent was dropped over 2 minutes. After all the ethanol was added, the mixture was further stirred for 5 minutes. Subsequently, 50 g of ion-exchanged water was added dropwise over 2 minutes. After the entire amount of ion-exchanged water was added, the mixture was further stirred for 5 minutes. Thereafter, the stirring was stopped and the mixture was allowed to stand at 25 ° C. for 1 hour. The obtained suspension was filtered, washed with 50 g of a mixed solvent having a ratio of ethanol and ion-exchanged water of 1: 1, and filtered. The obtained cake was vacuum-dried at a temperature of 50 ° C. for 10 hours to obtain 0.04 g of a powdery white solid.

  When the obtained powder was analyzed by a particle size distribution analyzer, it was polyamide resin fine particles having a volume average particle diameter of 26.9 μm and a particle diameter distribution index of 1.27. Oil absorption of linseed oil was 151 ml / 100 g and contained 0.4% by mass of ethyl acetoacetate. The solubility (25 ° C.) of the polyamide with respect to ethanol as a poor solvent and ion exchange was 0.0001% by mass or less. A scanning electron micrograph of the obtained fine particles is shown in FIG.

(Example 2) <Method 1 for producing polyamide 11 fine particles using ethyl acetoacetate and N-methylpyrrolidone solvent>
In a 200 ml four-neck separable flask, 2.00 g of polyamide 11 (“Rilsan” BMNO manufactured by Arkema Co., Ltd.) as a polyamide resin, 50.0 g of ethyl acetoacetate as a ketoester compound as a constituent material of an organic solvent, organic 48.0 g of N-methylpyrrolidone was added as a solvent, heated to a temperature of 180 ° C., and stirred until the polymer was completely dissolved. Thereafter, the temperature of the system was lowered to 25 ° C. while stirring was continued. Thereafter, the stirring was stopped and the mixture was allowed to stand at 25 ° C. for 1 hour. The obtained suspension was filtered, washed with 50 g of a mixed solvent having a ratio of ethanol and ion-exchanged water of 1: 1, and filtered. The obtained cake was vacuum-dried at a temperature of 50 ° C. for 10 hours to obtain 1.71 g of a powdery white solid.

  When the obtained powder was analyzed by a particle size distribution analyzer, it was a polyamide resin fine particle having a volume average particle diameter of 25.4 μm and a particle diameter distribution index of 1.82. Oil absorption of linseed oil was 208 ml / 100 g and contained 0.5% by mass of ethyl acetoacetate. The solubility (25 ° C.) of the polyamide with respect to ethanol as a poor solvent and ion exchange was 0.0001% by mass or less. A scanning electron micrograph of the obtained fine particles is shown in FIG.

(Example 3) <Method 2 for producing polyamide 11 fine particles using ethyl acetoacetate and N-methylpyrrolidone solvent>
In a 200 ml four-necked separable flask, 0.5 g of polyamide 11 (“Rilsan” BMNO manufactured by Arkema Co., Ltd.) as a polyamide resin, 50.0 g of ethyl acetoacetate as a ketoester compound as an organic solvent constituent, organic 49.5 g of N-methylpyrrolidone was added as a solvent, heated to a temperature of 180 ° C., and stirred until the polymer was completely dissolved. Thereafter, the temperature of the system was lowered to 60 ° C. while stirring was continued. Subsequently, 50 g of ethanol as a poor solvent was dropped over 2 minutes. After all the ethanol was added, the mixture was further stirred for 5 minutes. Thereafter, the stirring was stopped and the mixture was allowed to stand at 25 ° C. for 1 hour. The obtained suspension was filtered, washed with 50 g of a mixed solvent having a ratio of ethanol and ion-exchanged water of 1: 1, and filtered. The obtained cake was vacuum-dried at a temperature of 50 ° C. for 10 hours to obtain 0.4 g of a powdery white solid.

  When the obtained powder was analyzed by a particle size distribution analyzer, it was a polyamide resin fine particle having a volume average particle size of 32.4 μm and a particle size distribution index of 2.40. The oil absorption of linseed oil was 284 ml / 100 g and contained 0.5% by mass of ethyl acetoacetate. The solubility (25 ° C.) of the polyamide with respect to ethanol as a poor solvent and ion exchange was 0.0001% by mass or less. A scanning electron micrograph of the obtained fine particles is shown in FIG.

Claims (8)

  Polyamide resin fine particles having a volume average particle diameter of 1 to 100 μm and comprising a keto ester compound of 0.0001% by mass to 10% by mass. 2. The polyamide resin fine particles according to claim 1, wherein the polyamide resin is polyamide 11 or polyamide 12.   The polyamide resin fine particles according to claim 1 or 2, wherein the particle size distribution index is 1 to 3.   The linseed oil absorption is 100 to 1000 mL / 100 g, polyamide resin fine particles according to any one of claims 1 to 3.   Ketoester compound is ethyl acetoacetate, methyl acetoacetate, ethyl 2-hexylacetoacetate, ethyl benzylacetoacetate, methyl levulinate, ethyl levulinate, butyl levulinate, isoamyl levulinate, methyl pyruvate, ethyl pyruvate, dihydrojasmon 5. The polyamide resin fine particle according to claim 1, which is at least one compound selected from the group consisting of methyl acid, dimethyl malonate and diethyl malonate.   A method for producing polyamide resin fine particles, wherein a polyamide resin is dissolved in an organic solvent containing a ketoester compound, a poor solvent of the polyamide resin is brought into contact with the obtained solution, and polyamide resin fine particles are precipitated.   7. The method for producing fine polyamide resin particles according to claim 6, wherein the poor solvent for the polyamide resin is at least one selected from ethanol, methanol and water.   A method for producing polyamide resin fine particles, wherein a polyamide resin is heated and dissolved in an organic solvent containing a ketoester compound, the temperature of the resulting solution is lowered, and polyamide resin fine particles are precipitated.