[go: up one dir, main page]

WO2023276585A1 - Procédé pour la production d'une particule composite et particule composite - Google Patents

Procédé pour la production d'une particule composite et particule composite Download PDF

Info

Publication number
WO2023276585A1
WO2023276585A1 PCT/JP2022/022996 JP2022022996W WO2023276585A1 WO 2023276585 A1 WO2023276585 A1 WO 2023276585A1 JP 2022022996 W JP2022022996 W JP 2022022996W WO 2023276585 A1 WO2023276585 A1 WO 2023276585A1
Authority
WO
WIPO (PCT)
Prior art keywords
cellulose
composite particles
micronized cellulose
ion
organic onium
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
PCT/JP2022/022996
Other languages
English (en)
Japanese (ja)
Inventor
佑美 大林
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Toppan Inc
Original Assignee
Toppan Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Toppan Inc filed Critical Toppan Inc
Publication of WO2023276585A1 publication Critical patent/WO2023276585A1/fr
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

Links

Images

Classifications

    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
    • C08F2/00—Processes of polymerisation
    • C08F2/44—Polymerisation in the presence of compounding ingredients, e.g. plasticisers, dyestuffs, fillers
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J3/00—Processes of treating or compounding macromolecular substances
    • C08J3/12—Powdering or granulating
    • C08J3/16—Powdering or granulating by coagulating dispersions

Definitions

  • the present invention relates to a method for producing composite particles composed of micronized cellulose and core particles, and the composite particles.
  • Patent Document 1 discloses that fine cellulose fibers, that is, cellulose nanofibers (hereinafter also referred to as "CNF”) can be obtained by repeatedly mechanically treating wood cellulose with a blender or a grinder.
  • CNFs obtained by this method are described as having a minor axis diameter of 10 to 50 nm and a major axis diameter of 1 ⁇ m to 10 mm.
  • This CNF is one-fifth the weight of steel and more than five times stronger than steel, and has a huge specific surface area of 250 m 2 /g or more. ing.
  • the method of chemical treatment is not particularly limited, but a method of introducing an ionic functional group into the cellulose fiber to make it easier to refine is preferable.
  • Non-Patent Document 1 discloses a method of selectively phosphating the surface of cellulose fine fibers using phosphating. ing.
  • Patent Literature 2 discloses carboxymethylation by reacting cellulose with monochloroacetic acid or sodium monochloroacetate in a highly concentrated alkaline aqueous solution.
  • a carboxyl group may be introduced by directly reacting a carboxylic acid anhydride compound such as maleic acid or phthalic acid gasified in an autoclave with cellulose.
  • TEMPO 2,2,6,6-tetramethylpiperidinyl-1-oxy radical
  • Patent Document 3 The oxidation reaction using TEMPO as a catalyst (TEMPO oxidation reaction) is an environmentally friendly chemical modification that progresses in an aqueous system at normal temperature and pressure. When applied to cellulose in wood, there is no reaction inside the crystal. It does not proceed, and only alcoholic primary carbons possessed by cellulose molecular chains on the crystal surface can be selectively converted into carboxyl groups.
  • CSNF Cellulose single nanofibers
  • Wood-derived CSNF obtained from wood by TEMPO oxidation reaction is a structure having a high aspect ratio with a short axis diameter of about 3 nm and a long axis diameter of several tens of nm to several ⁇ m. has been reported to have high transparency.
  • Patent Document 4 describes that a laminated film obtained by coating and drying a CSNF dispersion has gas barrier properties.
  • Patent Document 5 describes that a dispersion in which highly refined cellulose is dispersed in an organic solvent can be obtained by surface modification in which organic onium cations are arranged as counterions of cationic finely divided cellulose.
  • Patent Document 6 describes an aqueous coating liquid containing TEMPO-oxidized CNF. It is described that this water-based coating liquid has good coatability, and that a laminate having barrier properties can be obtained by coating it on the anchor layer.
  • Patent Document 7 discloses a coating liquid containing TEMPO-oxidized CNF in which carbon fine particles are dispersed and stabilized by the influence of the entanglement and thickening properties of cellulose nanofibers with a high aspect ratio, and the charge derived from the carboxy group. ing.
  • the problem is that the solid content concentration of the obtained CNF dispersion is as low as about 0.1 to 5%.
  • the solid content concentration of the obtained CNF dispersion is as low as about 0.1 to 5%.
  • it is transported together with a large amount of solvent, which increases transportation costs and greatly affects business feasibility.
  • problems such as poor addition efficiency due to low solid content concentration and difficulty in compounding when water, which is a solvent, is not compatible with resin. be.
  • countermeasures such as refrigerated storage and antiseptic treatment are required, which may cause an increase in cost.
  • the micronized cellulose will aggregate, keratinize, or form a film, and the expected function will not be stable when used as an additive. and may not appear. Furthermore, since the solid content concentration of CNF is low, a large amount of energy is required for the solvent removal process itself by drying, which is a hurdle to business feasibility.
  • Patent Document 8 describes composite particles containing a coating layer composed of cellulose fibers and a polymer covered with the coating layer.
  • this composite particle since the cellulose fiber and the polymer are integrated, they can be easily separated by filtration and distributed as powder. The redispersibility of the powder is also good.
  • Patent Document 8 Although the composite particles described in Patent Document 8 are excellent as a material that exhibits the properties of CNF as described above, there is room for improvement in that the types of applicable polymers are limited. When forming composite particles from a resin material that is difficult to apply, the yield drops significantly, the particle size distribution of the obtained particles increases, and the amount of CNF present on the surface of the particles is small. There are various problems such as not fully demonstrating
  • an object of the present invention is to provide composite particles of cellulose fibers that are excellent in handleability and have high versatility, and a method for producing the same.
  • a first aspect of the present invention is a method for producing composite particles.
  • This production method includes a first step of defibrating a cellulose raw material in a dispersion solvent to obtain a micronized cellulose dispersion in which micronized cellulose is dispersed, and adding an organic onium compound or an amine to the micronized cellulose dispersion. a second step of obtaining an ion-bonded micronized cellulose dispersion containing micronized cellulose bound with organic onium ions or ammonium ions; and a fourth step of solidifying the core particle precursor to form core particles and obtaining composite particles in which the core particles are coated with micronized cellulose that is inseparably bound to the core particles.
  • a second aspect of the present invention comprises a core particle comprising at least one polymer, and micronized cellulose having anionic functional groups disposed on the surface of the core particle inseparably bound to the core particle.
  • Composite particles In this composite particle, organic onium ions or ammonium ions are bound to at least part of the micronized cellulose.
  • FIG. 1 is a schematic diagram of a composite particle according to one embodiment of the present invention
  • FIG. It is a figure which shows an example of the manufacturing method of the same composite particle.
  • 4 is a graph showing the results of measuring the spectral transmission spectrum of an aqueous dispersion of cellulose nanofibers according to an example. It is a graph which shows the result of having performed steady-state viscoelasticity measurement using the rheometer with respect to the same aqueous dispersion.
  • 4 is a scanning electron microscope image of composite particles according to an example.
  • 4 is a scanning electron microscope image of composite particles according to an example.
  • 4 is a scanning electron microscope image of composite particles according to an example.
  • 4 is a scanning electron microscope image of composite particles according to an example.
  • 4 is a scanning electron microscope image of composite particles according to a comparative example.
  • 4 is a scanning electron microscope image of composite particles according to a comparative example. 4 is a graph showing particle size distributions of composite particles according to Examples and Comparative Examples
  • FIG. 1 shows a schematic diagram of a composite particle 5 according to this embodiment.
  • Composite particle 5 comprises core particle 3 and micronized cellulose 1 located on the surface of core particle 3 .
  • the micronized cellulose 1 is combined with the core particle 3 and is inseparable.
  • the mode of bonding between the micronized cellulose 1 and the core particles 3 is not particularly limited. It is preferable to form the coating layer 10 which consists of layers.
  • Organic onium cations or amines 7a are bound to at least part of the micronized cellulose 1 as counter cations.
  • the ionized state of the organic onium compound may be referred to as “organic onium ion” or “organic onium cation”.
  • the term "amine” as used herein includes partially or wholly ionized ammonium ions.
  • organic onium compound/amine an organic onium compound or an amine, or an organic onium cation or an ammonium ion
  • organic onium compound/amine organic onium cation (or organic onium ion)/ammonium ion
  • Composite particles 5 of the present embodiment are produced in an O/W type Pickering emulsion using micronized cellulose 1 to which organic onium ions/ammonium ions 7a are bound as counter cations (counter ions) of anionic functional groups. It is obtained by solidifying a core particle precursor (hereinafter also simply referred to as “droplets”) present as (oil phase, oil particles, dispersed phase).
  • a core particle precursor hereinafter also simply referred to as “droplets” present as (oil phase, oil particles, dispersed phase).
  • the core particle precursor may be any material as long as it solidifies to form a core particle, and is, for example, a polymerizable compound, a molten polymer, or a dissolved polymer. Solidification of the core particle precursor can be accomplished in a variety of ways. For example, a monomer having a polymerizable functional group (hereinafter also referred to as a "polymerizable monomer”) is used as a core particle precursor, and a polymerization granulation method (emulsion polymerization method, suspension polymerization method) in which particles are formed in the polymerization process.
  • a polymerizable monomer emulsion polymerization method, suspension polymerization method
  • solidifying the core particle precursor means (A) polymerizing the polymerizable monomer droplets, (B) cooling the molten polymer droplets to solidify them, and (C) dissolving the It is a concept that includes all of solidification by removing the solvent from the polymer droplets.
  • the O/W Pickering emulsion is stabilized by adsorption of the micronized cellulose 1 on the interface of droplets containing the core particle precursor dispersed in the dispersion solvent of the continuous phase (aqueous phase).
  • aqueous phase a continuous phase
  • composite particles 5 can be produced using the emulsion as a template.
  • the "stabilized state of the emulsion” means a state in which the droplet size of the emulsion does not change even if it is allowed to stand still for a long period of time (for example, 12 hours).
  • the emulsion is unstable, some of the droplets coalesce over time, causing the particle size distribution of the droplets to shift to a larger size compared to the initial stage, or to cause variations in the particle size distribution. Furthermore, in some cases separation of oil and water phases occurs. As a result, the yield of the composite particles obtained may decrease, and the particle diameters of the composite particles may become non-uniform.
  • finely divided cellulose 1 in which organic onium ions/ammonium ions 7a are bonded as counter ions of anionic functional groups a stable O/W type Pickering emulsion is formed with many core particle precursors. Therefore, composite particles 5 having a small particle size and uniformity can be obtained at a high yield.
  • micronized cellulose 1 which is solid particles that have been micronized to submicron order, is adsorbed on the interface of droplets by physical force, forming a cellulose barrier against the aqueous phase. Once adsorbed and an interface is formed, the emulsion structure is stabilized because greater energy is required for desorption.
  • the micronized cellulose 1 has amphipathic properties, and the hydrophobic side of the micronized cellulose 1 is adsorbed to droplets having hydrophobicity, and the hydrophilic side of the micronized cellulose 1 is directed to the hydrophilic dispersion solvent. As a result, the effect of improving the stability of the droplet interface is also presumed.
  • the adsorptive power of the micronized cellulose 1 at this interface is determined by the high affinity of the solid particles for the oil phase and the aqueous phase, that is, the affinity of the micronized cellulose 1 for the core particle precursor and the dispersion solvent of the micronized cellulose 1. depends on both the affinity for
  • the affinity of the micronized cellulose 1 for droplets containing the core precursor is increased, and the adsorptive power is improved.
  • a stable O/W-type Pickering emulsion can be formed using a large amount of core precursor, and composite particles 5 having a small particle size and a uniform particle size can be obtained at a high yield.
  • an organic onium compound / amine is used, and the counter ion of the anionic functional group of the finely divided cellulose 1 is an organic onium ion / A method using ammonium ions 7a is preferred.
  • an organic onium compound/ A method of adding an amine and stirring for a while is mentioned.
  • the term “inseparable” indicating the bonding state between the core particles 3 and the micronized cellulose 1 means that the micronized cellulose 1 and the core particles 3 cannot be separated even after performing a predetermined separation operation. However, it means that the state of covering the core particles 3 with the micronized cellulose 1 is maintained.
  • the predetermined separation operation is, for example, an operation of centrifuging the dispersion containing the composite particles 5 to remove the supernatant, then adding a solvent and redispersing to purify and wash the composite particles 5, or a membrane filter. An operation of repeating the operation of washing with a solvent repeatedly by filtration washing using is mentioned.
  • the coating state of the core particles 3 with the micronized cellulose 1 can be confirmed by surface observation of the composite particles 5 with a scanning electron microscope (SEM). Although the detailed mechanism by which the micronized cellulose 1 and the core particles 3 are inseparably bonded has not been clarified, the composite particles 5 are produced using an O/W emulsion stabilized by the micronized cellulose 1 as a template. Therefore, when the solidification of the droplet proceeds while the micronized cellulose 1 is in contact with the droplet inside the emulsion, part of the micronized cellulose 1 is fixed while remaining in the droplet, and finally the core It is believed that the particles 3 and micronized cellulose 1 are inseparably bound. O/W emulsions are also called oil-in-water emulsions, in which water is a continuous phase in which oil is dispersed as oil droplets (oil particles).
  • the composite particles 5 are produced using an O/W emulsion stabilized by the micronized cellulose 1 as a template, one of their characteristics is that they have a shape close to a true sphere derived from the O/W emulsion.
  • composite particles 5 having a uniform particle size can be obtained from a stable O/W emulsion.
  • the coating layer 10 containing the micronized cellulose 1 is formed on the surface of the spherical core particle 3 with a relatively uniform thickness.
  • the composite particles 5 of the present embodiment are spherical, and preferably spherical.
  • the micronized cellulose 1 forms a stable O/W-type Pickering emulsion, whereby spherical composite particles 5 can be obtained.
  • the index of sphericity can be evaluated from circularity.
  • the degree of circularity is preferably 0.6 or more, more preferably 0.7 or more, and still more preferably 0.9 or more.
  • the circularity can be calculated as the average circularity of 1000 or more particles measured by an image analysis type particle size distribution meter.
  • the calculated average circularity may be used as an index of the sphericity.
  • the particle size of the composite particles 5 can be confirmed by optical microscope observation.
  • the average particle size can be calculated by taking the average value of the diameters of the composite particles 5 after randomly measuring 100 locations.
  • the calculated average particle diameter may be used as the particle diameter of the composite particles 5 .
  • the average particle diameter is not particularly limited, it is preferably 0.01 ⁇ m or more and 1000 ⁇ m or less.
  • the average particle size is more preferably 0.05 ⁇ m or more and 100 ⁇ m or less, and still more preferably 0.10 ⁇ m or more and 50 ⁇ m or less.
  • Composite particles 5 having a small average particle size can be obtained by the micronized cellulose 1 adsorbing to the liquid-liquid interface to form a stable Pickering emulsion.
  • the maximum particle size of the composite particles 5 can be obtained by randomly measuring 100 composite particles 5 with an optical microscope and taking the maximum value of the diameter. Although not particularly limited, the maximum particle size of the composite particles 5 is preferably 200 ⁇ m or less, more preferably 100 ⁇ m or less, and even more preferably 50 ⁇ m or less. Since the composite particles 5 in the present embodiment can be obtained using a stable emulsion as a template, the maximum particle size is small.
  • a particle size distribution analyzer such as a laser diffraction particle size distribution analyzer or an image analysis particle size distribution analyzer can also be used to measure the particle size.
  • the micronized cellulose 1 preferably forms a coating layer 10 on the surface of the core particles 3 .
  • the coating layer 10 preferably covers the entire surface of the core particle 3, but does not necessarily have to cover the entire surface.
  • the thickness of the coating layer 10 composed of the micronized cellulose 1 is not particularly limited, it is preferably 3 nm or more and 1000 nm or less.
  • the average thickness of the coating layer 10 is obtained by cutting a resin piece in which the composite particles 5 are fixed with the embedding resin with a microtome and performing SEM observation. It is obtained by randomly measuring 100 points and calculating the arithmetic mean value.
  • Another feature of the composite particles 5 is that the coating layer 10 has a uniform thickness.
  • the coefficient of variation of the value of the thickness of the coating layer 10 (the standard deviation of 30 points randomly extracted from the 100 points described above) is preferably 0.5 or less, more preferably 0.4 or less.
  • the micronized cellulose 1 in the present embodiment is a fiber made of cellulose or a cellulose derivative and having a number average minor axis diameter of 1 nm or more and 1000 nm or less, such as cellulose nanofiber (CNF).
  • CNF is micronized cellulose 1 that can be obtained by pulverizing a cellulose raw material obtained from wood or the like into ultrafine fibers, and is safe and biodegradable.
  • the micronized cellulose 1 preferably has a fibrous shape derived from a microfibril structure. Specifically, the micronized cellulose 1 is fibrous, has a number average minor axis diameter of 1 nm or more and 1000 nm or less, a number average major axis diameter of 50 nm or more, and a number average minor axis diameter of is preferably 5 times or more. Moreover, the crystallinity of the micronized cellulose 1 is preferably 50% or more. The crystal structure of the micronized cellulose 1 is preferably cellulose I type.
  • the crystal surface of the micronized cellulose 1 of the present embodiment preferably has an anionic functional group.
  • the anionic functional group include, but are not particularly limited to, a carboxy group, a phosphate group, and a sulfo group. Among them, a carboxy group and a phosphate group are preferred, and a carboxy group is preferred because of ease of selective introduction to the cellulose crystal surface.
  • the micronized cellulose 1 in the present embodiment is not particularly limited, it has an anionic functional group on the crystal surface, and the content of the anionic functional group is 0.1 mmol/g or more and 5.0 mmol per micronized cellulose. /g or less. More preferably, it is 0.5 mmol/g or more and 2.0 mmol/g or less. If it is less than 0.1 mmol/g, the stability of the emulsion may deteriorate, resulting in a wide particle size distribution. Moreover, if it exceeds 5.0 mmol/g, it may become difficult to stably produce the composite particles 5 .
  • the amount of anionic functional groups on the surface side of the micronized cellulose 1 bonded to the composite particles 5 in the present embodiment is preferably 0.01 ⁇ mol/g or more per composite particle, more preferably 0.10 ⁇ mol/g. g or more and preferably 100 ⁇ mol/g or less, more preferably 50 ⁇ mol/g or less, and even more preferably 10 ⁇ mol/g or less. If it is less than 0.01 ⁇ mol/g, the emulsion stability may be poor and the particle size distribution may become wide. Moreover, if it exceeds 100 ⁇ mol/g, it may become difficult to stably produce the composite particles 5 .
  • the amount of anionic functional groups on the micronized cellulose 1 and on the surface side of the micronized cellulose 1 bound to the composite particles 5 is not particularly limited, but can be measured by electrical conductivity titration. Take a sample in a beaker, disperse it in ion-exchanged water, add 0.01 mol/L sodium chloride aqueous solution, add 0.1 mol/L hydrochloric acid while stirring, adjust the pH to 2 as a whole, and perform automatic titration.
  • the average bonding amount of the organic onium ion/ammonium ion 7a in the micronized cellulose 1 is preferably 0.02 mmol/g or more, more preferably 0.2 mmol/g or more per micronized cellulose from the viewpoint of emulsion stability. Yes, preferably 3 mmol/g or less, more preferably 2.5 mmol/g or less, still more preferably 2 mmol/g or less. Any two or more organic onium ions/ammonium ions 7a may be introduced into the micronized cellulose 1 at the same time. It is preferable that the total amount is within the above range.
  • the average binding amount (mmol/g) of organic onium ion/ammonium ion 7a can be measured by a known method. For example, it can be calculated by titration, IR measurement, or the like.
  • the average binding amount of the organic onium ion/ammonium ion 7a in the micronized cellulose 1 used in the present embodiment is preferably 0.01 equivalent or more, more preferably 0.05 equivalent or more with respect to the anionic functional group. and is preferably 0.8 equivalents or less, more preferably 0.50 equivalents or less, and still more preferably 0.30 equivalents or less.
  • the average binding amount is 0.01 equivalent or more and 0.8 equivalent or less, the surface of the micronized cellulose 1 can be sufficiently hydrophobized, a stable O/W emulsion can be formed, the particle size is small, This is preferable because uniform composite particles 5 can be obtained at a high yield.
  • the binding amount of the organic onium ion/ammonium ion 7a is less than 0.01 equivalent, the surface of the micronized cellulose 1 is not sufficiently hydrophobized, and the particle size tends to vary, resulting in a decrease in yield. On the other hand, if it exceeds 0.8 equivalents, the organic onium ion/ammonium ion 7a may decompose the micronized cellulose 1 or lower the affinity for the dispersion medium, which is not preferable.
  • the average binding amount (equivalent) of the organic onium ion/ammonium ion 7a is defined by A being the average binding amount (mmol/g) of the organic onium ion/ammonium ion 7a per micronized cellulose, and the amount of anionic functional groups per micronized cellulose. If (mmol/g) is B, it can be calculated as A/B.
  • the average binding amount of organic onium ions/ammonium ions 7a bound to the surface side of the micronized cellulose 1 of the composite particles 5 is preferably 0.01 ⁇ mol/g or more per composite particle, more preferably 0.01 ⁇ mol/g or more, from the viewpoint of emulsion stability. is 0.1 ⁇ mol/g or more, preferably 100 ⁇ mol/g or less, more preferably 50 ⁇ mol/g or less, still more preferably 10 ⁇ mol/g or less. When the average bonding amount of organic onium ions/ammonium ions 7a is within this range, the composite particles 5 have good dispersibility. Any two or more organic onium ions/ammonium ions 7a may be introduced into the micronized cellulose 1 at the same time.
  • the average binding amount ( ⁇ mol/g) of organic onium ion/ammonium ion 7a can be measured by a known method. For example, by washing the composite particles 5 with an acid such as hydrochloric acid, the organic onium ions/ammonium ions 7a can be separated from the composite particles 5 and calculated by liquid chromatography, titration, IR measurement, or the like.
  • the average binding amount of the organic onium ions/ammonium ions 7a bound to the surface side of the micronized cellulose 1 of the composite particles 5 is 0 with respect to the anionic functional groups present on the surface of the micronized cellulose 1 bonded to the composite particles 5. It is preferably 0.01 equivalent or more, more preferably 0.05 equivalent or more, and preferably 1.00 equivalent or less, more preferably 0.50 equivalent or less, and still more preferably 0.25 equivalent or less. be. When the average bonding amount of organic onium ions/ammonium ions 7a is within this range, the dispersibility and stability of the micronized cellulose 1 are good, so composite particles 5 with high dispersion stability can be obtained in a high yield.
  • the average bonding amount (equivalent) of the organic onium ion/ammonium ion 7a is determined by C being the average bonding amount (mmol/g) of the organic onium ion/ammonium ion 7a per composite particle, and the amount of anionic functional groups per composite particle (mmol /g) is D, it can be calculated as C/D.
  • the contact angle to water of the film produced using the micronized cellulose 1 is 45° or more, and more preferably 50° or more.
  • the contact angle was measured by pouring a 0.5% aqueous dispersion of micronized cellulose 1 into a 5 cm x 5 cm container, drying it at a temperature of 30°C and humidity of 80%, and then drying the film under a nitrogen atmosphere.
  • the contact angle can be obtained by dropping 2 ⁇ l of pure water using a contact angle meter (manufactured by Kyowa Interface Science Co., Ltd., PCA-1).
  • a cationic substance other than the organic onium ion/ammonium ion 7a may be bound as a counter ion.
  • cationic substances include, but are not limited to, alkali metals such as sodium ions, potassium ions and lithium ions, and metal ions such as alkaline earth metals such as magnesium ions and calcium ions. From the viewpoint of the dispersion stability of the micronized cellulose 1, alkali metal ions such as sodium ions, potassium ions, and lithium ions are preferred.
  • the binding equivalent of the cationic substance other than the organic onium ion/ammonium ion 7a is preferably 0.02 mmol/g or more per 1 micronized cellulose, from the viewpoint of the dispersion stability and emulsion stability of the micronized cellulose 1, More preferably, it is 0.2 mmol/g or more. Also, it is preferably 3 mmol/g or less, more preferably 2.5 mmol/g or less, still more preferably 2 mmol/g or less. Any two or more cationic substances may be introduced into the micronized cellulose 1 at the same time.
  • the average binding amount (mmol/g) of the cationic substance can be measured by a known method.
  • the EPMA (Electron Probe Micro Analyzer) method using an electron beam microanalyzer, X-ray fluorescence analysis, and ICP (Inductively Coupled Plasma) emission spectrometry are examples of simple methods for elemental analysis.
  • the amount of the cationic substance that binds to the anionic functional group is not particularly limited, it is 0.95 equivalent or less, preferably 0.90 or less, more preferably 0.80, relative to the anionic functional group of the micronized cellulose 1. It is below. If the amount of cationic substance exceeds 0.95 equivalents, the emulsion stability may be low, resulting in low yield and broad particle size distribution.
  • the average binding amount (equivalent) of the cationic substance is defined by E as the average binding amount (mmol/g) of the cationic substance per 1 micronized cellulose, and the anionic functional group content (mmol/g) per 1 micronized cellulose. If B is used, the calculation can be performed by E/B.
  • the binding equivalent of the cationic substance other than the organic onium ion/ammonium ion 7a is preferably 0.01 ⁇ mol/g or more per composite particle, more preferably It is 0.1 ⁇ mol/g or more. Also, it is preferably 100 ⁇ mol/g or less, more preferably 50 ⁇ mol/g or less, and even more preferably 10 ⁇ mol/g or less. When the binding amount of the cationic substance is within this range, the composite particles 5 have good dispersibility. Any two or more cationic substances may be introduced into the micronized cellulose 1 on the surface of the composite particles 5 at the same time.
  • the average binding amount ( ⁇ mol/g) of the cationic substance can be measured by a known method.
  • a known method for example, in the case of metal ions, an EPMA method using an electron beam microanalyzer, a fluorescent X-ray analysis method, an elemental analysis by ICP emission spectrometry, and the like can be exemplified as simple methods.
  • the composite particles 5 may be washed with an acid such as hydrochloric acid to separate the cationic substance and then analyzed by elemental analysis or the like.
  • the average binding amount of the cationic substance bound to the surface side of the micronized cellulose 1 of the composite particles 5 is 0.01 equivalent or more with respect to the anionic functional groups present on the surface of the micronized cellulose 1 bonded to the composite particles 5. is preferably 0.05 equivalents or more, preferably 1.00 equivalents or less, more preferably 0.50 equivalents or less, and even more preferably 0.25 equivalents or less. .
  • the average binding amount of the cationic substance is within this range, the stability of the micronized cellulose 1 is good, the emulsion stability is good, and the composite particles 5 can be obtained in a high yield. The dispersibility of is also improved.
  • the average binding amount (equivalent) of the cationic substance is given by the average binding amount (mmol/g) of the cationic substance per composite particle, F, and the anionic functional group amount (mmol/g) per composite particle, D. It can be calculated in F/D.
  • the core particles 3 preferably contain at least one type of polymer.
  • a known polymer can be used as the polymer, and a polymer obtained by polymerizing a polymerizable monomer by a known method may be used.
  • polymers examples include acrylic polymers, epoxy polymers, polyester polymers, amino polymers, silicone polymers, fluorine polymers, and urethane/isocyanate polymers.
  • a biodegradable polymer can be used for the core particle 3 of this embodiment.
  • the polymer is preferably a biodegradable polymer.
  • Biodegradability refers to a polymer that decomposes and disappears in the global environment such as soil and seawater, and/or a polymer that decomposes and disappears in vivo. In general, polymers are degraded by enzymes possessed by microorganisms in soil or seawater, whereas in vivo they are degraded by physicochemical hydrolysis without the need for enzymes.
  • Degradation of a polymer means that the polymer becomes low-molecular-weight or water-soluble and loses its shape.
  • Decomposition of the polymer is not particularly limited, but occurs by hydrolysis of the main chain, side chains and cross-linking points, and oxidative decomposition of the main chain.
  • Biodegradable polymers include natural polymers derived from nature and synthetic polymers.
  • natural polymers include polysaccharides produced by plants (cellulose, starch, alginic acid, etc.), polysaccharides produced by animals (chitin, chitosan, hyaluronic acid, etc.), proteins (collagen, gelatin, albumin, etc.), and those produced by microorganisms. polyester (poly(3-hydroxyalkanoate)), polysaccharide (hyaluronic acid, etc.) and the like.
  • Synthetic polymers include, for example, aliphatic polyesters, polyols, and polycarbonates.
  • Fatty acid polyesters include, for example, glycol-dicarboxylic acid polycondensation systems (polyethylene succinate, polybutylene succinate, etc.), polylactides (polyglycolic acid, polylactic acid, etc.), polylactones ( ⁇ -caprolactone, ⁇ -caprolactone, etc.). , and others (polybutylene terephthalate, adipate, etc.).
  • polyols examples include polyvinyl alcohol.
  • polycarbonate examples include polyester carbonate.
  • polyacid anhydrides polycyanoacrylates, polyorthoesters, polyphosphazenes, etc. are also biodegradable synthetic polymers.
  • the core particles 3 may contain other components in addition to the polymer.
  • colorants oil absorbers, light shielding agents (ultraviolet absorbers, ultraviolet scattering agents, etc.), antibacterial agents, antioxidants, antiperspirants, antifoaming agents, antistatic agents, binders, bleaching agents, chelating agents, Deodorizing ingredients, fragrances, fragrances, anti-dandruff actives, emollients, insect repellents, preservatives, natural extracts, beauty ingredients, pH adjusters, vitamins, amino acids, hormones, oils and waxes and other oil-based ingredients , surfactants, inorganic particles (titanium oxide, silica, clay, etc.), and the like.
  • the content of other components in the composite particles 5 is not particularly limited, and is preferably within a range in which the composite particles 5 can stably maintain their shape.
  • the content of other components is preferably 0.001 parts by mass or more and 80 parts by mass or less when the composite particles 5 are 100 parts by mass.
  • the method for producing composite particles according to the present embodiment includes a first step of defibrating a cellulose raw material in a dispersion solvent 4 to obtain a micronized cellulose dispersion in which micronized cellulose 1 is dispersed, and a micronized cellulose dispersion.
  • the composite particles 5 obtained by the above production method are obtained as a dispersion.
  • a dry solid of composite particles 5 with good handleability is obtained.
  • the method of removing the dispersion solvent 4 is not particularly limited, and examples thereof include a method of removing the dispersion solvent 4 by a centrifugal separation method or a filtration method, and a method of removing the dispersion solvent 4 by evaporating it in an oven or the like.
  • a dry solid of composite particles 5 may be obtained by purification and drying. At this time, the dry solid matter of the composite particles 5 obtained does not form a film or an aggregate, but is a fine powder.
  • the reason for this is not clear, in the case of the dispersion containing the composite particles 5, since the composite particles 5 are substantially spherical composite particles 5 in which the micronized cellulose 1 is immobilized on the surface, even if the dispersion solvent 4 is removed, the micronized
  • the cellulose 1 does not agglomerate and the adjacent composite particles are only in point contact with each other. Since the composite particles 5 do not aggregate, it is easy to redisperse the composite particles 5 obtained as a dry powder in a solvent. show gender.
  • the dry powder of the composite particles 5 is a dry solid that contains almost no solvent and is redispersible in a solvent.
  • the solid content can be 80% or more, Further, it can be 90% or more, and further can be 95% or more. Since the dispersion of the composite particles 5 can be almost easily removed from the solvent, favorable effects can be obtained from the viewpoints of reduction in transportation costs, prevention of spoilage, improvement in addition rate, and improvement in kneading efficiency with the resin. Even when the solid content is increased to 80% or more by drying, the micronized cellulose 1 easily absorbs moisture. The following may occur.
  • the solid content of the dry powder containing the composite particles 5 should be 80% or more. It should be said that any dry solid obtained through the process of is included in the technical scope of the present invention. Each step of the manufacturing method will be described in detail below.
  • the first step is a step of defibrating the cellulose raw material in the dispersion solvent 4 to obtain a fine cellulose dispersion.
  • various cellulose raw materials are dispersed in the dispersion solvent 4 to form a suspension.
  • the concentration of the cellulose raw material in the suspension is preferably 0.1% or more and less than 10%. If the concentration of the cellulose raw material in the suspension is less than 0.1%, the amount of solvent becomes excessive, which tends to impair productivity, which is not preferable. Further, if the concentration of the cellulose raw material in the suspension is 10% or more, the suspension will rapidly increase in viscosity as the cellulose raw material is defibrated, and uniform defibration tends to become difficult, which is not preferable. .
  • the dispersion solvent 4 used for preparing the suspension preferably contains 50% or more water. If the proportion of water in the suspension is less than 50%, the dispersion of the micronized cellulose 1 tends to be inhibited in the process of obtaining a micronized cellulose dispersion by fibrillating the cellulose raw material in the dispersion solvent 4, which will be described later.
  • a hydrophilic solvent is preferable as the solvent contained in addition to water.
  • the hydrophilic solvent is not particularly limited, but alcohols such as methanol, ethanol and isopropanol, and cyclic ethers such as tetrahydrofuran are preferred. If necessary, the pH of the suspension may be adjusted, for example, in order to increase the dispersibility of the cellulose and the micronized cellulose 1 to be produced.
  • alkaline aqueous solutions used for pH adjustment include sodium hydroxide aqueous solution, lithium hydroxide aqueous solution, potassium hydroxide aqueous solution, ammonia aqueous solution, tetramethylammonium hydroxide (tetramethylammonium hydroxide, TMAH) aqueous solution, and tetraethylammonium hydroxide.
  • organic onium compounds such as (tetraethylammonium hydroxide, TEAH) aqueous solution, tetrabutylammonium hydroxide (tetrabutylammonium hydroxide, TBAH) aqueous solution, and benzyltrimethylammonium hydroxide aqueous solution;
  • TEAH tetraethylammonium hydroxide
  • TBAH tetrabutylammonium hydroxide
  • benzyltrimethylammonium hydroxide aqueous solution benzyltrimethylammonium hydroxide aqueous solution
  • a sodium hydroxide aqueous solution is preferable from the viewpoint of cost.
  • the suspension is subjected to a physical defibration process to refine the cellulose raw material.
  • the method of physical fibrillation treatment is not particularly limited, but for example, high pressure homogenizer, ultra high pressure homogenizer, ball mill, roll mill, cutter mill, planetary mill, jet mill, attritor, grinder, juicer mixer, homomixer, ultrasonic homogenizer. , nanogenizer, and mechanical treatments such as underwater counter-collision.
  • the cellulose in the suspension is made finer, and at least one side of the structure is made finer to the order of nanometers (micronized cellulose 1) dispersion liquid. can be obtained.
  • the number average minor axis diameter and the number average major axis diameter of the micronized cellulose 1 to be obtained can be adjusted by the time and frequency of the physical defibration treatment at this time.
  • a dispersion (micronized cellulose dispersion) of the micronized cellulose 1, which is micronized so that at least one side of the structure is on the order of nanometers, is obtained.
  • the resulting dispersion can be used as it is or after dilution, concentration, etc., as a stabilizer for an O/W emulsion, which will be described later.
  • the dispersion of the micronized cellulose 1 may optionally contain other components other than the cellulose and the components used for adjusting the pH within a range that does not impair the effects of the present invention.
  • the other components are not particularly limited, and can be appropriately selected from known additives according to the use of the composite particles 5 and the like.
  • organometallic compounds such as alkoxysilanes or hydrolysates thereof, inorganic layered compounds, inorganic acicular minerals, antifoaming agents, inorganic particles, organic particles, lubricants, antioxidants, antistatic agents, Ultraviolet absorbers, stabilizers, magnetic powders, orientation promoters, plasticizers, cross-linking agents, magnetic substances, pharmaceuticals, agricultural chemicals, fragrances, adhesives, enzymes, pigments, dyes, deodorants, metals, metal oxides, inorganic oxides and the like.
  • the micronized cellulose 1 usually has a fiber shape derived from a microfibril structure
  • the micronized cellulose 1 used in the production method of the present embodiment preferably has a fiber shape within the range shown below. That is, the shape of the micronized cellulose 1 is preferably fibrous.
  • the number average minor axis diameter of the fibrous micronized cellulose 1 should be 1 nm or more and 1000 nm or less, preferably 2 nm or more and 500 nm or less.
  • the number average minor axis diameter is not particularly limited, but it is preferably five times or more the number average minor axis diameter. If the number average major axis diameter is less than five times the number average minor axis diameter, it tends to be difficult to sufficiently control the size and shape of the composite particles 5, which is not preferable.
  • the number average minor axis diameter of the micronized cellulose 1 is obtained by measuring the minor axis diameter (minimum diameter) of 100 fibers by, for example, transmission electron microscope observation or atomic force microscope observation, and calculating the average value thereof.
  • the number average major axis diameter of the micronized cellulose 1 is obtained by measuring the major axis diameter (maximum diameter) of 100 fibers by, for example, transmission electron microscopy or atomic force microscopy, and calculating the average value. .
  • raw materials composed of type I cellulose crystals include, in addition to natural wood cellulose, non-wood natural cellulose such as cotton linter, bamboo, hemp, bagasse, kenaf, bacterial cellulose, sea squirt cellulose, and valonia cellulose. can be used. Furthermore, regenerated cellulose represented by rayon fibers and cupra fibers composed of cellulose type II crystals can also be used. It is preferable to use wood-based natural cellulose as a raw material because of the ease of material procurement.
  • the wood-based natural cellulose is not particularly limited. For example, softwood pulp, hardwood pulp, waste paper pulp, and the like, which are generally used for producing cellulose nanofibers, can be used. Softwood pulp is preferred because of its ease of refining and miniaturization.
  • the micronized cellulose raw material is chemically modified. More specifically, it is preferable that an anionic functional group is introduced to the crystal surface of the micronized cellulose raw material. This is because the presence of an anionic functional group on the surface of the cellulose crystals facilitates penetration of the solvent into the space between the cellulose crystals due to the effect of osmotic pressure, thereby facilitating the miniaturization of the cellulose raw material.
  • the type and introduction method of the anionic functional group to be introduced into the crystal surface of cellulose are not particularly limited, and a carboxy group and a phosphate group, such as a carboxy group, a phosphate group, and a sulfo group, are preferred.
  • a carboxy group is preferred because of its ease of selective introduction to the cellulose crystal surface.
  • the method of introducing carboxyl groups onto the surface of cellulose fibers is not particularly limited. Specifically, for example, carboxymethylation may be performed by reacting cellulose with monochloroacetic acid or sodium monochloroacetate in a high-concentration alkaline aqueous solution. Alternatively, a carboxyl group may be introduced by directly reacting a carboxylic acid anhydride compound such as maleic acid or phthalic acid gasified in an autoclave with cellulose. Furthermore, under relatively mild conditions of an aqueous system, a co-oxidant is added in the presence of an N-oxyl compound such as TEMPO, which has a high selectivity for the oxidation of alcoholic primary carbon while maintaining the structure as much as possible. You may use the method used. Oxidation using an N-oxyl compound is more preferable for the selectivity of the carboxy group-introducing site and the reduction of the environmental load.
  • examples of the N-oxyl compound include TEMPO (2,2,6,6-tetramethylpiperidinyl-1-oxy radical), 2,2,6,6-tetramethyl-4-hydroxypiperidine- 1-oxyl, 4-methoxy-2,2,6,6-tetramethylpiperidine-N-oxyl, 4-ethoxy-2,2,6,6-tetramethylpiperidine-N-oxyl, 4-acetamido-2, 2,6,6-tetramethylpiperidine-N-oxyl, and the like.
  • TEMPO which has high reactivity, is preferable.
  • the amount of the N-oxyl compound to be used is not particularly limited and may be the amount required for the catalyst. Usually, it is about 0.01 to 5.0% by mass based on the solid content of wood-based natural cellulose to be oxidized.
  • an oxidation method using an N-oxyl compound for example, wood-based natural cellulose is dispersed in water, and an oxidation treatment is performed in the presence of an N-oxyl compound. At this time, it is preferable to use a co-oxidizing agent together with the N-oxyl compound.
  • the N-oxyl compound is sequentially oxidized by the co-oxidizing agent in the reaction system to form an oxoammonium salt, and the oxoammonium salt oxidizes the cellulose.
  • this oxidation treatment the oxidation reaction proceeds smoothly even under mild conditions, and the introduction efficiency of the carboxy group is improved. If the oxidation treatment is performed under mild conditions, the crystalline structure of cellulose can be easily maintained.
  • co-oxidants examples include halogens, hypohalous acids, halogenous acids and perhalogenates, salts thereof, halogen oxides, nitrogen oxides, peroxides, etc., which can promote the oxidation reaction. Any oxidizing agent, if any, can be used. Sodium hypochlorite is preferred because of its availability and reactivity.
  • the amount of the co-oxidizing agent to be used is not particularly limited and may be an amount capable of promoting the oxidation reaction. Usually, it is about 1 to 200% by mass based on the solid content of the wood-based natural cellulose to be oxidized.
  • At least one compound selected from the group consisting of bromides and iodides may be used in combination with the N-oxyl compound and the co-oxidizing agent.
  • the oxidation reaction can proceed smoothly, and the introduction efficiency of the carboxy group can be improved.
  • sodium bromide or lithium bromide is preferable, and sodium bromide is more preferable in terms of cost and stability.
  • the amount of the compound to be used is not particularly limited as long as it can promote the oxidation reaction. Usually, it is about 1 to 50% by mass based on the solid content of the wood-based natural cellulose to be oxidized.
  • the reaction temperature of the oxidation reaction is preferably 4° C. or higher and 80° C. or lower, more preferably 10° C. or higher and 70° C. or lower.
  • the reaction temperature of the oxidation reaction is lower than 4°C, the reactivity of the reagent tends to decrease and the reaction time tends to become longer.
  • the reaction temperature of the oxidation reaction exceeds 80°C, the side reaction is accelerated, the cellulose sample becomes low-molecular, and the highly crystalline, rigid, micronized cellulose 1-fiber structure collapses, stabilizing the O/W emulsion. It tends to be difficult to use as an agent.
  • the reaction time of the oxidation treatment can be appropriately set in consideration of the reaction temperature, the desired amount of carboxy groups, etc., and is not particularly limited, but is usually about 10 minutes to 5 hours.
  • the pH of the reaction system during the oxidation reaction is not particularly limited, it is preferably 9-11.
  • the pH is 9 or more, the reaction can proceed efficiently. If the pH exceeds 11, side reactions may proceed and the decomposition of the sample cellulose may be accelerated.
  • the oxidation treatment as the oxidation progresses, carboxyl groups are generated and the pH in the system decreases, so it is preferable to maintain the pH of the reaction system at 9 to 11 during the oxidation treatment.
  • a method of maintaining the pH of the reaction system at 9 to 11 for example, a method of adding an alkaline aqueous solution according to the decrease in pH can be mentioned.
  • alkaline aqueous solutions include sodium hydroxide aqueous solution, lithium hydroxide aqueous solution, potassium hydroxide aqueous solution, ammonia aqueous solution, tetramethylammonium hydroxide (tetramethylammonium hydroxide, TMAH) aqueous solution, tetraethylammonium hydroxide (tetraethylammonium hydroxide , TEAH) aqueous solution, tetrabutylammonium hydroxide (tetrabutylammonium hydroxide, TBAH) aqueous solution, and organic onium compounds such as benzyltrimethylammonium hydroxide aqueous solution.
  • TMAH tetramethylammonium hydroxide
  • TEAH tetraethylammonium hydroxide
  • TBAH tetrabutylammonium hydroxide
  • organic onium compounds such as benzyltrimethylammonium hydro
  • a sodium hydroxide aqueous solution, a lithium hydroxide aqueous solution, and a potassium hydroxide aqueous solution are preferable from the viewpoint of cost.
  • a cationic substance contained in the alkaline aqueous solution used to maintain the pH during the oxidation reaction binds as a counterion to the carboxy group generated by the oxidation reaction.
  • the cationic substance of the counter ion of the carboxy group of the TEMPO-oxidized cellulose is preferably alkali metal ions such as sodium ion, potassium ion and lithium ion, and metal ions such as alkaline earth metal such as magnesium ion and calcium ion.
  • the organic onium ion/ammonium ion 7a has a strong ionization tendency. easily binds to the anionic functional group of the micronized cellulose 1 as a counterion.
  • the oxidation reaction by the N-oxyl compound can be stopped, for example, by adding alcohol to the reaction system. At this time, it is preferable to keep the pH of the reaction system within the above range.
  • alcohol to be added for example, low-molecular-weight alcohols such as methanol, ethanol and propanol are preferable in order to quickly complete the reaction, and ethanol is particularly preferable in view of the safety of by-products produced by the reaction.
  • the reaction solution after the oxidation treatment may be directly subjected to the micronization step, but in order to remove catalysts such as N-oxyl compounds, impurities, etc., the oxidized cellulose contained in the reaction solution is recovered and washed with a washing solution.
  • the TEMPO-oxidized cellulose can be collected by a known method such as filtration using a glass filter or a nylon mesh with a pore size of 20 ⁇ m. Pure water or an acidic solution such as hydrochloric acid is preferable as the cleaning liquid used for cleaning the TEMPO-oxidized cellulose.
  • the counterions of the carboxyl groups of the TEMPO-oxidized cellulose are maintained without being replaced, so the counterions of the carboxyl groups of the TEMPO-oxidized cellulose after washing become metal ions. Also, by washing with an acid such as hydrochloric acid, it is possible to remove at least part of the counterions and convert the carboxy groups of the TEMPO-oxidized cellulose to COOH.
  • the carboxy group of TEMPO-oxidized cellulose is COOH or the counter ion is a metal ion
  • the organic onium ion/ammonium ion 7a has a strong ionization tendency. easily binds to the anionic functional group of the micronized cellulose 1 as a counterion.
  • TEMPO-oxidized cellulose nanofibers (hereinafter also referred to as TEMPO-oxidized CNF, cellulose single nanofibers, CSNF) having a uniform fiber width of about 3 nm are obtained.
  • TEMPO-oxidized CNF cellulose single nanofibers
  • CSNF cellulose single nanofibers
  • the CSNF used in the present embodiment can be obtained by a process of oxidizing a cellulose raw material and a process of pulverizing and dispersing it.
  • the content of carboxyl groups to be introduced into CSNF is preferably 0.1 mmol/g or more and 5.0 mmol/g or less, more preferably 0.5 mmol/g or more and 2.0 mmol/g or less.
  • the amount of carboxyl groups is less than 0.1 mmol/g, there is a tendency that it becomes difficult to make the cellulose fine and uniformly disperse it, because the solvent penetration action due to the osmotic pressure effect does not work between the cellulose microfibrils. be.
  • the cellulose microfibrils become low-molecular-weight due to a side reaction accompanying the chemical treatment, so that highly crystalline, rigid, micronized cellulose 1 fibers cannot be obtained, and O/W type. It tends to be difficult to use as an emulsion stabilizer.
  • the counter ion of the carboxyl group of CSNF obtained by the step of oxidizing the cellulose raw material, filtering and washing, and finely dispersing into a dispersion liquid is sodium ion, It becomes metal ions such as alkali metals such as potassium ions and lithium ions, and alkaline earth metals such as magnesium ions and calcium ions.
  • the counterion of the carboxy group of CSNF is a metal ion, the surface of CSNF is highly hydrophilic.
  • the amount of metal ions bound to CSNF is preferably 0.1 mmol/g or more and 5.0 mmol/g or less, and is preferably 0.5 mmol/g or more and 2.0 mmol/g or less. more preferred.
  • the binding amount of metal ions is less than 0.1 mmol/g, the solvent penetration action due to the osmotic pressure effect does not work between the cellulose microfibrils, making it difficult to make the cellulose fine and uniformly disperse it.
  • the cellulose microfibrils become low-molecular-weight due to side reactions accompanying the chemical treatment, making it impossible to obtain a highly crystalline, rigid, micronized cellulose 1-fiber structure. It tends to be difficult to use as a stabilizer for O/W emulsions.
  • the metal ion content can be examined by various analytical methods. For example, the EPMA method using an electron beam microanalyzer, X-ray fluorescence analysis, and elemental analysis such as ICP emission spectrometry can be easily examined. can.
  • an organic onium compound/amine is added to the micronized cellulose dispersion obtained in the first step and stirred to convert the micronized cellulose 1 contained in the micronized cellulose dispersion into organic onium ions/ammonium ions.
  • the anionic functional group of the micronized cellulose 1 can easily be paired. Ions can be exchanged.
  • the cationic substance as the counter ion of the anionic functional group is a metal ion such as sodium ion.
  • Micronized cellulose 1 can be obtained by filtering and washing TEMPO-oxidized cellulose with metal ions as counter ions, suspending it in dispersion solvent 4, and subjecting it to physical fibrillation.
  • preparation of micronized cellulose to which organic onium cations/ammonium ions 7a are bound by conventional methods is complicated.
  • an acid is added to the oxidation reaction solution to adjust the inside of the system to be acidic, and the carboxylic acid is separated by filtration.
  • /amine is added and stirred to bind organic onium ions/ammonium ions 7a, and this suspension is subjected to a physical defibration treatment to form fine particles having anionic functional groups to which organic onium ions/ammonium ions 7a are bound.
  • a modified cellulose 1 is prepared.
  • organic onium ions/ammonium ions 7a are produced by a simple method of adding an organic onium compound/amine in the second step to the micronized cellulose 1 obtained in the first step and stirring.
  • An ionically bound micronized cellulose dispersion containing bound micronized cellulose 1 can be obtained. Hydrophobicity is thereby imparted to a part of the micronized cellulose 1 .
  • the anionic finely divided cellulose 1 to which an organic onium compound/amine is added may form a salt with a cationic substance as a counterion, but may not contain a cationic substance.
  • the cationic substance of the counter ion preferably has a stronger ionization tendency than the organic onium ion/ammonium ion 7a. The stronger the ionization tendency of the cationic substance, the more efficiently counter ion substitution proceeds, which is preferable.
  • the cationic substance of the counter ion is preferably, for example, an alkali metal ion such as sodium ion, potassium ion or lithium ion, or a metal ion such as alkaline earth metal ion such as magnesium ion or calcium ion. Even after binding organic onium ions/ammonium ions 7a to the anionic functional groups of at least a portion of the micronized cellulose 1, the cationic substance may remain in a portion of the anionic functional groups. Although the amount of the cationic substance remaining in the anionic functional group is not particularly limited, it is 0.95 equivalent or less, preferably 0.90 equivalent or less, more preferably 0.95 equivalent or less, relative to the anionic functional group of the micronized cellulose 1.
  • the content of cationic substances in the micronized cellulose 1 can be examined by various analytical methods.
  • the cationic substance is a metal
  • an EPMA method using an electron beam microanalyzer, elemental analysis by fluorescent X-ray analysis, and the like can be exemplified as simple methods.
  • the micronized cellulose 1 is repeatedly washed under acidic conditions, then purified by repeatedly washing with pure water, and then subjected to the physical defibration treatment described above again. I can give an example.
  • the amount of the organic ammonium compound/amine added to the micronized cellulose dispersion is preferably 0.01 equivalent or more and 2 equivalents or less with respect to the anionic functional group contained in the micronized cellulose 1.
  • the amount added is 0.02 equivalent or more and 1.8 equivalent or less
  • the surface of the micronized cellulose 1 can be sufficiently hydrophobized, a stable O/W emulsion can be formed, and the particle size is uniform. It is preferable because the composite particles 5 can be obtained with a high yield.
  • the amount of the organic onium compound/amine added is less than 0.01 equivalent, the hydrophobization of the surface of the micronized cellulose 1 is not sufficient, and the particle size tends to vary, and the yield may decrease.
  • the amount exceeds 2 equivalents excessive addition of the organic onium compound/amine may cause decomposition of the micronized cellulose 1 or decrease in affinity to the dispersion medium, which is not preferable.
  • the average binding amount of the organic onium ion/ammonium ion 7a in the micronized cellulose 1 is 0.01 equivalent or more, preferably 0.05 equivalent or more, preferably 0.8 equivalent or less, and preferably 0.8 equivalent or less with respect to the anionic functional group. is 0.50 equivalents or less, more preferably 0.30 equivalents or less.
  • the average bonding amount of the organic onium ion/ammonium ion 7a is within this range, the dispersibility and stability of the micronized cellulose 1 are improved.
  • the average binding amount (equivalent) of the organic onium ion/ammonium ion 7a is defined by A being the average binding amount (mmol/g) of the organic onium ion/ammonium ion 7a per micronized cellulose, and the amount of anionic functional groups per micronized cellulose. If (mmol/g) is B, it can be calculated as A/B.
  • A the average binding amount of the organic onium ion/ammonium ion 7a per micronized cellulose
  • B it can be calculated as A/B.
  • the average binding amount is 0.01 equivalent or more and 0.8 equivalent or less, the surface of the micronized cellulose 1 can be sufficiently hydrophobized, a stable O/W emulsion can be formed, the particle size is small, This is preferable because uniform composite particles 5 can be obtained at a high yield.
  • the binding amount of the organic onium ion/ammonium ion 7a is less than 0.01 equivalent, the surface of the micronized cellulose 1 is not sufficiently hydrophobized, and the particle size tends to vary, resulting in a decrease in yield. On the other hand, if it exceeds 0.8 equivalents, the organic onium ion/ammonium ion 7a may decompose the micronized cellulose 1 or lower the affinity for the dispersion medium, which is not preferable.
  • the type of organic onium compound/amine may be one type, or two or more types may be mixed and used.
  • organic oniums or amines having different structures of hydroxyl groups or hydrocarbon groups may be mixed and used.
  • the hydrocarbon group may be linear or branched.
  • Water is suitable as the dispersion solvent 4 when the organic onium compound/amine is added to the micronized cellulose 1, and it is preferable that the water content is 50% or more.
  • the proportion of micronized cellulose 1 in the dispersion is preferably 0.1% or more and less than 10%. If it is less than 0.1%, the amount of the solvent becomes excessive when defibrating the cellulose raw material in the first step, which impairs productivity, which is not preferable.
  • the yield of the composite particles 5 decreases, and the particle diameter tends to vary. If it is 10% or more, the suspension will rapidly thicken as the cellulose raw material is defibrated, making it difficult to perform a uniform fibrillation treatment, which is not preferable. Moreover, since the viscosity of the dispersion liquid of micronized cellulose 1 increases, it becomes difficult to form an O/W emulsion in the third step.
  • the method of obtaining the micronized cellulose dispersion containing the micronized cellulose 1 to which the organic onium ions/ammonium ions 7a are bound is not particularly limited. may be added to the dispersion and stirred to obtain the dispersion.
  • concentration of the organic onium compound/amine in the aqueous solution in which the organic onium compound/amine is dissolved is not particularly limited, it is preferably 0.01M or more and 5.0M or less.
  • the pH of the dispersion liquid of micronized cellulose 1 to which the organic onium compound/amine is added is not particularly limited, and is preferably 4 or more and 12 or less, more preferably 6 or more and 10 or less.
  • the anionic functional groups of the micronized cellulose 1 are likely to be ionized, and the osmotic pressure effect makes it easier for the solvent to penetrate between the fibers of the micronized cellulose 1, increasing the dispersion stability of the micronized cellulose 1. .
  • the pH after adding the organic onium compound/amine to the micronized cellulose 1 is preferably 4 or more and 12 or less.
  • the anionic functional group of the micronized cellulose 1 is ionized, so that the solvent easily penetrates between the fibers of the micronized cellulose 1 due to the osmotic pressure effect, and the micronized cellulose 1 is dispersed. Increased stability.
  • the pH is less than 4, the dispersibility of the micronized cellulose 1 is lowered.
  • the pH exceeds 12
  • the anionic finely divided cellulose 1 undergoes a peeling reaction or alkali hydrolysis, resulting in a low molecular weight, and terminal aldehydes and double bond formation accelerate yellowing of the dispersion. , unfavorable.
  • the temperature at which the organic onium compound/amine is added to the micronized cellulose 1 and stirred is not particularly limited, it is preferably 4°C or higher and 80°C or lower, more preferably 10°C or higher and 70°C or lower. If the temperature is less than 4° C., the exchange efficiency of the counter ion will be poor. If the temperature exceeds 80° C., the cellulose tends to have a low molecular weight and the fibrous structure of the highly crystalline rigid micronized cellulose 1 collapses, making it difficult to use it as a stabilizer for O/W emulsions.
  • the stirring time can be appropriately set in consideration of the temperature, the desired amount of anionic functional groups, etc., and is not particularly limited, but is usually about 10 minutes to 5 hours.
  • the organic onium compound in this embodiment has a cation structure of the structural formula shown in Chemical formula 1.
  • M is a nitrogen atom, a phosphorus atom, a hydrogen atom, or a sulfur atom
  • R1, R2, R3, and R4 are a hydrogen atom, a hydrocarbon group, or a hydrocarbon group containing a hetero atom.
  • the organic onium compound is ammonia.
  • R1, R2, R3, and R4 are hydrogen atoms, it is a primary amine, two when it is a secondary amine, one when it is a tertiary amine, and zero when it is a quaternary amine, Both are organic onium compounds in the present embodiment.
  • hydrocarbon groups containing heteroatoms include alkyl groups, alkylene groups, oxyalkylene groups, aralkyl groups, aryl groups, and aromatic groups.
  • R1, R2, R3 and R4 may form a ring.
  • Examples of quaternary ammonium compounds in which M is a nitrogen atom in the above structural formula include tetraethylammonium hydroxide (TEAH), tetraethylammonium chloride, tetrabutylammonium hydroxide (TBAH), tetrabutylammonium chloride, didecyl dimethylammonium chloride, lauryltrimethylammonium chloride, dilauryldimethylchloride, stearyltrimethylammonium chloride, distearyldimethylammonium chloride, cetyltrimethylammonium chloride, alkylbenzyldimethylammonium chloride, coconut amine.
  • TEAH tetraethylammonium hydroxide
  • TBAH tetrabutylammonium hydroxide
  • didecyl dimethylammonium chloride lauryltrimethylammonium chloride, dilauryldimethylchloride, ste
  • Examples of quaternary phosphonium compounds in which M is a phosphorus atom in the above structural formula include tetramethylphosphonium hydroxide, tetraethylphosphonium hydroxide, tetrapropylphosphonium hydroxide, tetrabutylphosphonium hydroxide, and benzyltrimethylphosphonium hydroxide. , benzyltriethylphosphonium hydroxide, hexadecyltrimethylphosphonium hydroxide and the like.
  • the primary amine, secondary amine, and tertiary amine in the present embodiment have the structures shown in formulas (1), (2), and (3) of chemical formula 2, respectively.
  • the structures when these are ionized to become ammonium ions with a cationic structure are (1)', (2)', and (3)', respectively.
  • (1)' is a primary ammonium ion
  • (2)' is a secondary ammonium ion
  • (3)' is a tertiary ammonium ion.
  • R1 to R6 are either a hydrocarbon group or a hydrocarbon group containing a heteroatom.
  • Primary amine, secondary amine and tertiary amine include methylamine, ethylamine, propylamine, butylamine, n-octylamine, dimethylamine, diethylamine, dipropylamine, dibutylamine, hexylamine and 2-ethylamine.
  • PEG- NH 2 polyethylene glycolamine
  • EO/PO ethylene oxide/propylene oxide
  • the counter ion of the cationic structure of the organic onium compound/amine is not particularly limited.
  • the counter ion of the cation structure of the organic onium compound include nitrate ion, sulfate ion, hydroxide ion, chloride ion, bromide ion, iodide ion and the like.
  • the use of a salt organic onium compound in which the counter ion of the cationic structure is a chloride ion or a bromide ion can suppress the increase in pH even when added to the finely divided cellulose dispersion, making it easy to control the pH.
  • the organic onium compound may be a hydrate.
  • an inorganic alkali containing a metal salt such as an alkali metal or an alkaline earth metal may be added in addition to the organic onium compound.
  • the micronized cellulose 1 obtained by adding an organic onium compound/amine to the micronized cellulose 1 and combining the organic onium ion/ammonium ion 7a has a higher dispersion than when an inorganic alkali having a metal ion as a counter ion is used. good dispersion stability. This is because the use of an organic onium compound/amine has a larger ion diameter of the counter ion of the anionic site of the micronized cellulose 1, and thus has a greater effect of separating the micronized cellulose 1 from each other in the dispersion solvent 4. it is conceivable that.
  • the dispersion contains an organic onium compound/amine
  • the viscosity and thixotropy of the dispersion can be reduced compared to inorganic alkali, which is advantageous in terms of ease of emulsification in the third step described below and subsequent handling.
  • the micronized cellulose 1 interacting with the organic onium compound/amine through ionic bonds is reduced in hydrophilicity due to the steric repulsion or hydrophobizing action based on the organic onium ion/ammonium ion 7a.
  • the affinity of the liquid core particle precursor 2 to the emulsion droplets is increased in the third step, which will be described later, and the stability of the droplets 6 is improved.
  • the obtained micronized cellulose dispersion may contain other ingredients other than cellulose and the ingredients used for adjusting the pH, if necessary, within a range that does not impair the effects of the present invention.
  • Other components are not particularly limited, and can be appropriately selected from known additives according to the use of the composite particles 5 and the like.
  • organic metal compounds such as alkoxysilanes or hydrolysates thereof, inorganic layered compounds, inorganic acicular minerals, antifoaming agents, inorganic particles, organic particles, lubricants, antioxidants, antistatic agents, UV absorbers, stabilizers, magnetic powders, orientation accelerators, plasticizers, cross-linking agents, magnetic substances, pharmaceuticals, agricultural chemicals, fragrances, adhesives, enzymes, pigments, dyes, deodorants, metals, metal oxides, inorganic oxidation things, etc.
  • organic metal compounds such as alkoxysilanes or hydrolysates thereof, inorganic layered compounds, inorganic acicular minerals, antifoaming agents, inorganic particles, organic particles, lubricants, antioxidants, antistatic agents, UV absorbers, stabilizers, magnetic powders, orientation accelerators, plasticizers, cross-linking agents, magnetic substances, pharmaceuticals, agricultural chemicals, fragrances, adhesives, enzymes, pigments, dyes, deodorants, metals, metal oxide
  • the third step is a step of stabilizing the liquid droplets 6 containing the core particle precursor 2 as an emulsion in the dispersion liquid of the micronized cellulose to which the organic onium ions/ammonium ions 7a are bonded obtained in the second step. .
  • a liquid oil phase (dispersed phase) containing the core particle precursor 2 is added to the dispersion (aqueous phase, dispersed phase) obtained in the second step, and as shown in FIG.
  • Droplets 6 containing the core particle precursor 2 are dispersed in the dispersion liquid.
  • the surfaces of the droplets 6 are coated with the micronized cellulose 1, and an O/W emulsion stabilized by the coating layer 10 is produced.
  • micronized cellulose 1 obtained in the second step to which the organic onium ions/ammonium ions 7a are bonded and at least a portion of the surface of which is hydrophobized even if a wide variety of core particle precursors 2 are used,
  • the micronized cellulose 1 is stably adsorbed on the droplets 6, and a stable O/W emulsion can be obtained.
  • the method for producing an O/W emulsion is not particularly limited, but general emulsification treatments such as various homogenizer treatments and mechanical stirring treatments can be used.
  • Mechanical treatments such as ball mills, roll mills, cutter mills, planetary mills, jet mills, attritors, grinders, juicer mixers, homomixers, ultrasonic homogenizers, nanogenizers, underwater counter-impingement, and paint shakers. Also, a plurality of mechanical treatments may be used in combination.
  • a polymerizable monomer is added to the micronized cellulose dispersion obtained in the first step to form a mixed solvent, and the tip of the ultrasonic homogenizer is inserted into the mixed solvent to perform ultrasonic treatment.
  • the processing conditions of the ultrasonic homogenizer are not particularly limited, but, for example, the frequency is generally 20 kHz or higher and the output is generally 10 W/cm 2 or higher.
  • the treatment time is also not particularly limited, but is usually about 10 seconds to 1 hour.
  • the droplets 6 containing the core particle precursor 2 are dispersed in the dispersion liquid, emulsification progresses, and further, the finely divided cellulose is selectively formed at the liquid/liquid interface between the droplets 6 and the dispersion liquid.
  • adsorbing 1 droplets 6 are coated with micronized cellulose 1 to form a stable structure as an O/W emulsion.
  • Such an emulsion stabilized by adsorption of a solid substance to the liquid/liquid interface is academically called a "Pickering emulsion".
  • cellulose has hydrophilic sites derived from hydroxyl groups and hydrophobic sites derived from hydrocarbon groups in its molecular structure. Since it exhibits amphiphilicity from , it is thought that it adsorbs to the liquid/liquid interface between the hydrophobic monomer and the hydrophilic solvent due to the amphiphilicity.
  • the O/W emulsion structure can be confirmed by optical microscope observation.
  • the particle size of the O/W emulsion is not particularly limited, it is usually preferably about 0.1 ⁇ m to 1000 ⁇ m.
  • the average particle size of the emulsion is preferably 0.1 ⁇ m or more and 100 ⁇ m or less, more preferably 0.1 ⁇ m or more and 50 ⁇ m or less, and still more preferably 0.1 ⁇ m or more and 20 ⁇ m or less.
  • the average particle size of the emulsion is not particularly limited, but can be calculated by measuring the particle size of 100 emulsion droplets with an optical microscope and averaging them.
  • the thickness of the coating layer 10 formed on the surface layer of the droplet 6 is not particularly limited, but is usually about 3 nm to 1000 nm.
  • the thickness of the coating layer 10 can be measured using, for example, a cryo-TEM (Transmission Electron Microscope).
  • the liquid oil phase (dispersed phase) containing the core particle precursor 2 may contain the core particle precursor 2 and form an O/W emulsion as the droplets 6. In order to stably form , it is preferably incompatible with the dispersion liquid of the micronized cellulose 1 and hydrophobic.
  • the core particle precursor 2 is a precursor that solidifies to form the core particles 3 by chemical change or physicochemical change.
  • the compound having polymerizability includes a monomer having a polymerizable functional group (polymerizable monomer), an oligomer having a polymerizable functional group (polymerizable oligomer), and a polymer having a polymerizable functional group (polymerizable polymer). and the like, which can form a solid polymer by a polymerization reaction.
  • Melting polymers include those that are thermoplastic polymers that melt into a liquid state by heating and undergo a phase transition to become a solid at room temperature.
  • the (C) dissolved polymer includes a non-curable polymer that dissolves into a liquid state with a solvent and becomes solid at room temperature when the solvent is removed.
  • the polymerizable monomer has at least one polymerizable functional group.
  • a polymerizable monomer having one polymerizable functional group is also called a monofunctional monomer.
  • a polymerizable monomer having two or more polymerizable functional groups is also called a polyfunctional monomer.
  • the type of the polymerizable monomer is not particularly limited, examples thereof include (meth)acrylic monomers and vinyl monomers.
  • a polymerizable monomer having a cyclic ether structure such as an epoxy group or an oxetane structure (eg, ⁇ -caprolactone, etc.) can also be used. Note that the notation of "(meth)acrylate” includes both "acrylate” and "methacrylate”.
  • Examples of monofunctional (meth)acrylic monomers include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, t-butyl (meth)acrylate, glycidyl (meth)acrylate, acryloylmorpholine, N-vinylpyrrolidone, tetrahydrofurfuryl acrylate, cyclohexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isobornyl ( meth)acrylate, isodecyl (meth)acrylate, lauryl (meth)acrylate, tridecyl (meth)acrylate, cetyl (meth)acrylate, stearyl (meth)acrylate, benzyl (meth)acrylate, 2-ethoxyethyl (me
  • bifunctional (meth)acrylic monomers include ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, butanediol di(meth)acrylate, hexanediol di(meth)acrylate, nonanediol di(meth)acrylate.
  • acrylate ethoxylated hexanediol di(meth)acrylate, propoxylated hexanediol di(meth)acrylate, diethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate)
  • Di(meth)acrylates such as (meth)acrylates, neopentyl glycol di(meth)acrylates, ethoxylated neopentyl glycol di(meth)acrylates, tripropylene glycol di(meth)acrylates, and neopentyl glycol hydroxypivalate di(meth)acrylates meth)acrylate and the like.
  • trifunctional or higher (meth)acrylic monomers examples include trimethylolpropane tri(meth)acrylate, ethoxylated trimethylolpropane tri(meth)acrylate, propoxylated trimethylolpropane tri(meth)acrylate, tris-2-hydroxy Ethyl isocyanurate tri(meth)acrylate, tri(meth)acrylate such as glycerin tri(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol tri(meth)acrylate, ditrimethylolpropane tri(meth)acrylate, etc.
  • Trifunctional (meth)acrylate compounds pentaerythritol tetra (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, dipentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, ditrimethylolpropane penta ( Trifunctional or higher polyfunctional (meth)acrylate compounds such as meth)acrylate, dipentaerythritol hexa(meth)acrylate, ditrimethylolpropane hexa(meth)acrylate, and some of these (meth)acrylates are alkyl groups or ⁇ - Polyfunctional (meth)acrylate compounds substituted with caprolactone, and the like.
  • monofunctional vinyl-based monomers liquids which are incompatible with water at room temperature, such as vinyl ether-based, vinyl ester-based, aromatic vinyl-based, particularly styrene and styrene-based monomers, are preferred.
  • (meth)acrylates among monofunctional vinyl-based monomers include methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, t-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, lauryl ( meth)acrylate, alkyl (meth)acrylate, tridecyl (meth)acrylate, stearyl (meth)acrylate, cyclohexyl (meth)acrylate, benzyl (meth)acrylate, isobornyl (meth)acrylate, glycidyl (meth)acrylate, tetrahydrofurfuryl ( meth)acrylate, allyl (meth)
  • the monofunctional aromatic vinyl monomers include styrene, ⁇ -methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, ethylstyrene, isopropenyltoluene, isobutyltoluene, tert-butylstyrene, vinyl naphthalene, vinylbiphenyl, 1,1-diphenylethylene, and the like.
  • Polyfunctional vinyl-based monomers include polyfunctional groups having unsaturated bonds such as divinylbenzene. Liquids that are incompatible with water at room temperature are preferred.
  • polyfunctional vinyl-based monomers specifically include (1) divinyls such as divinylbenzene, 1,2,4-trivinylbenzene and 1,3,5-trivinylbenzene, and (2) ethylene glycol.
  • Dimethacrylate diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, 1,3-propylene glycol dimethacrylate, 1,4-butylene glycol dimethacrylate, 1,6-hexamethylene glycol dimethacrylate, neopentyl glycol dimethacrylate Dimethacrylates such as methacrylate, dipropylene glycol dimethacrylate, polypropylene glycol dimethacrylate, 2,2-bis(4-methacryloxydiethoxyphenyl)propane, (3) trimethylolpropane trimethacrylate, triethylolethane trimethacrylate, etc.
  • trimethacrylates (4) ethylene glycol diacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, polyethylene glycol diacrylate, 1,3-dipropylene glycol diacrylate, 1,4-dibutylene glycol diacrylate, 1,6 - hexylene glycol diacrylate, neopentyl glycol diacrylate, dipropylene glycol diacrylate, polypropylene glycol diacrylate, 2,2-bis(4-acryloxypropoxyphenyl)propane, 2,2-bis(4-acryloxydi (5) triacrylates such as trimethylolpropane triacrylate and triethylolethane triacrylate; (6) tetraacrylates such as tetramethylolmethane tetraacrylate; Examples include tetramethylenebis(ethyl fumarate), hexamethylenebis(acrylamide), triallyl cyanurate and triallyl isocyanurate.
  • functional styrene monomers include divinylbenzene, trivinylbenzene, divinyltoluene, divinylnaphthalene, divinylxylene, divinylbiphenyl, bis(vinylphenyl)methane, bis(vinylphenyl)ethane, bis(vinyl phenyl)propane, bis(vinylphenyl)butane, and the like.
  • polyether resins polyester resins, polyurethane resins, epoxy resins, alkyd resins, spiroacetal resins, polybutadiene resins, polythiol polyene resins, etc. having at least one or more polymerizable functional groups
  • the material is not particularly limited.
  • the various polymerizable monomers described above may be used alone, or two or more of them may be used in combination.
  • the thermoplastic polymer preferably has a melting point of 40°C or higher and 80°C or lower. If the melting point is lower than 40° C., it becomes difficult to maintain the shape as a solid at room temperature, which is not preferable because the usage environment is extremely restricted. On the other hand, if the melting point exceeds 80° C., it is difficult to maintain the molten state in the finely divided cellulose dispersion in terms of the production process, which is not preferred. More preferably, the melting point is 45°C or higher and 75°C or lower. Also, the melt flow rate (MFR) above the melting point is preferably 10 or more. If the MFR is less than 10, the emulsification treatment described above requires a large amount of emulsifying energy, which is not preferable.
  • MFR melt flow rate
  • the non-curable polymer is one that dissolves in a solvent other than water and has a liquid state.
  • the solvent for dissolving the non-curable polymer preferably has a water solubility of 20 g or more and 2000 g or less per 1 L of water at 20°C. If it is less than 20 g, the affinity between the droplets containing the solvent and the micronized cellulose 1 is low, and the emulsion stabilizing effect of the micronized cellulose 1 is reduced. On the other hand, if it is more than 2000 g, the droplets cannot maintain their shape due to the high diffusion speed of the solvent in the finely divided cellulose dispersion. As a result, the droplet covering effect of the micronized cellulose 1 is impaired.
  • thermoplastic polymer and the non-curable polymer are not limited as long as the functions of the present embodiment are not impaired.
  • the various monofunctional monomers described above polymers starting from polymerizable monomers having a cyclic ether structure such as an epoxy group or an oxetane structure, or polyether resins, polyester resins, polyurethane resins, epoxy resins, and alkyd resins. , spiroacetal resins, polybutadiene resins, polythiolpolyene resins, and the like can be used.
  • Biodegradable polymers can also be used as thermoplastic polymers and non-curable polymers.
  • the biodegradable polymer is not particularly limited as long as it is biodegradable and does not dissolve in water.
  • cellulose acetate derivatives such as cellulose acetate, cellulose acetate butyrate, and cellulose acetate propionate.
  • polysaccharides such as chitin and chitosan
  • polylactic acids such as polylactic acid and copolymers of lactic acid and other hydroxycarboxylic acids
  • dibasic acid polyesters such as polybutylene succinate, polyethylene succinate and polybutylene adipate
  • Polycaprolactones such as polycaprolactone, copolymers of caprolactone and hydroxycarboxylic acid
  • polyhydroxybutyrates such as polyhydroxybutyrate, copolymers of polyhydroxybutyrate and hydroxycarboxylic acid, polyhydroxybutyric acid
  • poly Examples include aliphatic polyesters such as copolymers of hydroxybutyric acid and other hydroxycarboxylic acids, polyamino acids, polyester polycarbonates, and natural resins such as rosin. These compounds can be used alone or in combination of two or more.
  • the weight ratio of the micronized cellulose dispersion (aqueous phase, continuous phase) and the core particle precursor 2 in the third step is not particularly limited. is preferably 1 part by mass or more and 50 parts by mass or less. If the amount of the core particle precursor 2 is 1 part by mass or less, the yield of the composite particles 5 will decrease.
  • a polymerization initiator may be contained in advance.
  • general polymerization initiators include radical initiators such as organic peroxides and azo polymerization initiators.
  • organic peroxides examples include peroxyketals, hydroperoxides, dialkyl peroxides, diacyl peroxides, peroxycarbonates, and peroxyesters.
  • ADVN, AIBN, etc. can be illustrated as an azo polymerization initiator.
  • AIBN 2,2-azobis(isobutyronitrile)
  • AMBN 2,2-azobis(2-methylbutyronitrile)
  • ADVN 2,2-azobis(2,4-dimethylvaleronitrile)
  • ACVA 4,4-azobis(4-cyanovaleric acid)
  • ACVA 1, 1-azobis(1-acetoxy-1-phenylethane
  • 2,2- Azobis(2-methylamidinopropane) dihydrochloride 2,2-azobis[2-(2-imidazolin-2-yl)propane], 2,2-azobis[2-methyl-N-(2-hydroxyethyl) propion
  • the droplets of the emulsion contain the polymerization initiator when the O/W emulsion is formed.
  • the polymerization reaction for polymerizing the monomer inside the droplets of the emulsion proceeds more easily.
  • the weight ratio of the polymerizable monomer and the polymerization initiator in the third step is not particularly limited, it is usually preferable that the polymerization initiator is 0.1 parts by mass or more with respect to 100 parts by mass of the polymerizable monomer. If the amount of the polymerization initiator is less than 0.1 parts by mass, the polymerization reaction does not proceed sufficiently, and the yield of the composite particles 5 decreases, which is not preferable.
  • a method of obtaining a molten polymer by melting a thermoplastic polymer for example, a polymer that is solid at room temperature is melted to make it liquid. While the molten polymer is mechanically treated with an ultrasonic homogenizer or the like as described above, the dispersion of micronized cellulose 1 obtained in the second step is heated to a temperature at which the molten state of the polymer can be maintained.
  • the addition of molten polymer preferably stabilizes the molten polymer droplets as an O/W emulsion in the dispersion.
  • the solvent for dissolving the non-curable polymer to prepare the dissolved polymer is not particularly limited, but it is preferable to use an organic solvent in order to stabilize the emulsion.
  • an organic solvent for example, toluene, xylene, ethyl acetate, butyl acetate, methyl ethyl ketone (MEK), methyl isobutyl ketone (MIBK), isophorone, cellosolve acetate, isophorone, Solvesso 100, trichlene, hexane, chloroform, dichloromethane, dichloroethane, isooctane, nonane, etc. are used. be able to.
  • the mass ratio of the non-curable polymer and solvent is not particularly limited.
  • the weight of the solvent is preferably 0.005 parts by mass or more and 900 parts by mass or less, more preferably 0.1 parts by mass or more and 400 parts by mass or less per 100 parts by mass of the non-curable polymer. is preferred.
  • the liquid oil phase (dispersed phase) containing the core particle precursor 2 may contain functional components other than the polymerization initiator in advance.
  • functional components include solvents, magnetic substances, pharmaceuticals, agricultural chemicals, fragrances, adhesives, enzymes, pigments, dyes, deodorants, metals, metal oxides, inorganic oxides, and the like.
  • the functional component can be contained inside the core particle of the manufactured composite particles 5, and the function can be expressed according to the application. It becomes possible.
  • the fourth step is a step of solidifying the core particle precursor 2 to solidify the droplets 6 to obtain the composite particles 5 in which the core particles 3 are coated with the coating layer 10. be.
  • the method for solidifying the core particle precursor 2 is not particularly limited.
  • a compound having polymerizability is used as the core particle precursor 2, it can be solidified by polymerizing by heating, ultraviolet irradiation, or the like.
  • a molten polymer is used as the core particle precursor 2
  • the molten polymer can be cooled and solidified.
  • a dissolved polymer is used as the core particle precursor 2
  • the polymer can be solidified by removing the solvent by a method of diffusing the solvent inside the droplets 6 into the dispersion solvent 4 or a method of evaporating the solvent.
  • the polymerization method is not particularly limited, and can be appropriately determined depending on the type of polymerizable monomer and the type of polymerization initiator used.
  • An example of the polymerization method is a suspension polymerization method.
  • a specific suspension polymerization method is also not particularly limited, and a known method can be used.
  • the core particle precursor 2 can be solidified by heating the O/W emulsion obtained in the third step while stirring.
  • the stirring method is also not particularly limited, and a known method can be used. Specifically, a disper or a stirrer can be used. In some cases, it can be solidified only by heat treatment without stirring.
  • the temperature conditions during heating can be appropriately determined depending on the type of polymerizable monomer and the type of polymerization initiator, and may be, for example, 20° C. or higher and 150° C. or lower. If the temperature is less than 20°C, the polymerization reaction rate may decrease, and if it exceeds 150°C, the micronized cellulose 1 may be denatured.
  • the time for the polymerization reaction can be appropriately determined depending on the type of polymerizable monomer and the type of polymerization initiator, and may be, for example, about 1 hour to 24 hours.
  • the polymerization reaction may be carried out by ultraviolet irradiation treatment, which is a type of electromagnetic waves. In addition to electromagnetic waves, particle beams such as electron beams may be used.
  • thermoplastic polymer When using a thermoplastic polymer, it is solidified by phase transition of the molten polymer. Cooling is the typical method of phase transition. At this time, the degree of crystallinity of the thermoplastic polymer can be controlled by controlling the cooling rate. Specific cooling methods include a method of diffusing in water or ice water, a method of contacting with a coolant such as liquid nitrogen, and a method of standing to cool.
  • a method for removing the solvent is not particularly limited, and examples thereof include a heating method, a pressure reduction method, an electromagnetic wave irradiation method, and a combination thereof.
  • the method for evaporating the solvent of the dissolved polymer is to evaporate and remove the solvent by heating and/or drying under reduced pressure.
  • the boiling point of the solvent is lower than that of water, it is possible to selectively remove the solvent.
  • the solvent can be efficiently removed by heating under reduced pressure conditions.
  • the heating temperature is preferably 20° C. or higher and 100° C. or lower, and the pressure is preferably 600 mHg or higher and 750 mmHg or lower.
  • the method of diffusing the solvent of the dissolved polymer into the dispersion solvent 4 is, specifically, to diffuse the solvent inside the droplets 6 into the dispersion solvent 4 by adding another solvent or salt to the O/W emulsion liquid. .
  • the solvent with low solubility in the dispersion solvent 4 diffuses into the aqueous phase of the dispersion solvent 4 over time, the dissolved polymer can be precipitated and solidified as particles.
  • substantially spherical composite particles 5 in which the polymer-containing core particles 3 are coated with the micronized cellulose 1 are obtained.
  • organic onium cations/ammonium ions 7a are bound to at least part of the micronized cellulose 1 existing on the surface.
  • the particle size of the composite particles 5 is relatively uniform, and the degree of uniformity is high.
  • the dispersion liquid is in a state in which the composite particles 5, a large amount of water, and the finely divided cellulose 1 that is not integrated with the core particles 3 and are free are mixed.
  • the recovery/purification method for extracting only the composite particles 5 from the dispersion liquid include washing by centrifugation and washing by filtration.
  • a known method can be used as a washing method by centrifugation.
  • the composite particles 5 in the dispersion are sedimented by centrifugation, the supernatant is removed, and the operation of redispersing in a mixed solvent of water and methanol is repeated, and the residual solvent is finally removed from the sediment obtained by centrifugation.
  • Composite particles 5 can be recovered by removing them.
  • a known method can also be used for filtration and washing. For example, suction filtration is repeated with water and methanol using a polytetrafluoroethylene (PTFE) membrane filter with a pore size of 0.1 ⁇ m, and finally the composite particles 5 are obtained by removing the residual solvent from the paste remaining on the membrane filter. can be recovered.
  • the method for removing the residual solvent is not particularly limited, and it can be carried out by air drying or heat drying in an oven.
  • the dry solid matter containing the composite particles 5 does not form a film or an aggregate, but is obtained as a fine powder.
  • the core particles 3 and the micronized cellulose 1 are inseparably bonded, and even after recovery and purification of only the composite particles 5, the micronized cellulose 1 and the core particles 3 cannot be separated. Therefore, the state of covering the core particles 3 with the micronized cellulose 1 is maintained.
  • the yield of the composite particles 5 obtained by the above steps is preferably 30% or more, more preferably 50% or more, still more preferably 60% or more.
  • the yield can be calculated as follows: Weight (g) of dry solid matter of composite particles 5/weight (g) of resin of core particle precursor 2 used for production ⁇ 100.
  • the fifth step is to remove the organic onium cation/ammonium ion 7a from the composite particles 5 obtained.
  • the fifth step is performed after the fourth step as necessary, and may be omitted if unnecessary in view of the use of the composite particles 5 and the like.
  • part of the micronized cellulose 1 has organic onium cations/ammonium ions 7a as counterions.
  • organic onium cation/ammonium ion 7a is not preferable in relation to the use of the composite particles 5, or when a cationic substance different from the organic onium cation/ammonium ion 7a is desired to be bound to the micronized cellulose 1 as an ionic bond.
  • a fifth step may be performed to remove the organic onium cation/ammonium ion 7a.
  • Ion exchange is mentioned as a method for removing the organic onium cation/ammonium ion 7a.
  • the organic onium cations/ammonium ions 7a can be removed by dispersing the composite particles 5 having the organic onium cations/ammonium ions 7a in an aqueous solution containing an acidic compound and then washing with pure water. After removing the organic onium cations/ammonium ions 7a, a desired cationic compound may be added to bond a cationic substance different from the organic onium cations/ammonium ions 7a to the anionic functional groups of the micronized cellulose 1 by ionic bonding. I do not care.
  • the composite particles 5 according to this embodiment have the micronized cellulose 1 present as the coating layer 10 on the surface. Moreover, the composite particles 5 have high biocompatibility and good dispersion stability derived from the micronized cellulose 1 .
  • the core particles 3 can be formed from a wide variety of resins, and composite particles that can be used in a wide variety of applications can be easily produced. obtained by the method. For example, thermoplastic composite particles, which have been difficult to produce in the past, can be easily produced.
  • micronized cellulose 1 acquires hydrophobicity due to the organic onium cations/ammonium ions 7a, thereby becoming amphiphilic.
  • the yield of the composite particles 5 is remarkably improved, the particle size distribution is made uniform, and the material is excellent.
  • the dry solid of the composite particles 5 exhibits the material properties of the micronized cellulose 1, but is obtained as a fine powder, and since there is no agglomeration of the particles, it can be easily dispersed again in a solvent. be. Since the micronized cellulose 1 and the core particles 3 are inseparably bonded, stable dispersion derived from the characteristics of the micronized cellulose 1 is exhibited even after redispersion.
  • the method for producing the composite particles 5 according to the present embodiment can easily obtain particles exhibiting the properties of the micronized cellulose 1 in a dry state and in a circulable state. Therefore, effects such as low environmental load, reduction in transportation costs, reduction in spoilage risk, improvement in addition efficiency as an additive, and improvement in kneading efficiency with hydrophobic resin can be expected.
  • Example 1> (First step: step of obtaining a micronized cellulose dispersion) (TEMPO oxidation of wood cellulose) 70 g of softwood kraft pulp was suspended in 3500 g of distilled water, and a solution prepared by dissolving 0.7 g of TEMPO and 7 g of sodium bromide in 350 g of distilled water was added and cooled to 20°C. 450 g of an aqueous sodium hypochlorite solution having a density of 1.15 g/mL and 2 mol/L was added dropwise to initiate an oxidation reaction.
  • TEMPO oxidation of wood cellulose 70 g of softwood kraft pulp was suspended in 3500 g of distilled water, and a solution prepared by dissolving 0.7 g of TEMPO and 7 g of sodium bromide in 350 g of distilled water was added and cooled to 20°C.
  • the temperature in the system was always kept at 20° C., and the decrease in pH during the reaction was kept at pH 10 by adding a 0.5N sodium hydroxide aqueous solution.
  • a 0.5N sodium hydroxide aqueous solution When the total added amount of sodium hydroxide reached 3.0 mmol/g with respect to the mass of cellulose, about 100 mL of ethanol was added to terminate the reaction. Thereafter, filtration and washing with distilled water were repeated using a glass filter to obtain TEMPO oxidized cellulose (oxidized cellulose, oxidized pulp).
  • the carboxy group content of the oxidized cellulose before dispersion treatment was calculated by the following method. 0.2 g of oxidized cellulose in terms of dry mass was placed in a beaker, and 80 mL of ion-exchanged water was added.
  • the crystallinity of TEMPO-oxidized cellulose was calculated.
  • TEMPO oxidized cellulose using a sample horizontal multipurpose X-ray diffractometer (trade name: Ultima III, manufactured by Rigaku), X-ray output: (40 kv, 40 mA), X in the range of 5 ° ⁇ 2 ⁇ ⁇ 35 ° A line diffraction pattern was measured. Since the obtained X-ray diffraction pattern is derived from the cellulose type I crystal structure, the crystallinity of the TEMPO-oxidized cellulose was calculated using the following formula (2) by the method shown below.
  • the number average axis diameter of the long axis of the micronized cellulose was obtained by measuring the long axis diameter (maximum diameter) of 100 fibers from an image observed with an atomic force microscope and calculating the average value. By similarly measuring the short axis diameter of the fiber, the number average axial diameter of the short axis of the micronized cellulose was calculated.
  • the rheology of a dispersion containing 0.5% by mass of micronized cellulose was measured using a rheometer (trade name: AR2000ex, manufactured by TA Instruments) with a cone plate having an inclination angle of 1°.
  • the temperature of the measurement part was adjusted to 25° C., and the shear viscosity was continuously measured at a shear rate of 0.01 s ⁇ 1 to 1000 s ⁇ 1 .
  • the results are shown in FIG.
  • the micronized cellulose dispersion exhibited thixotropic properties.
  • Table 1 shows shear viscosities at shear rates of 10 s ⁇ 1 and 100 s ⁇ 1 .
  • the micronized cellulose aqueous dispersion exhibited high transparency. Further, the number average short axis diameter of the micronized cellulose (TEMPO-oxidized CNF) contained in the micronized cellulose aqueous dispersion was 3 nm, and the number average long axis diameter was 831 nm. Furthermore, FIG. 4 shows the results of steady-state viscoelasticity measurement using a rheometer. As is clear from FIG. 4, the micronized cellulose dispersion exhibited thixotropic properties.
  • Step of producing O/W type emulsion 10 g of monofunctional methacrylate and isobornyl methacrylate (hereinafter also referred to as “IB-X”), which are polymerizable monomers, were used as the core particle precursor, and 2,2-azobis-2,4, which is a polymerization initiator, was used.
  • IB-X monofunctional methacrylate and isobornyl methacrylate
  • 2,2-azobis-2,4 which is a polymerization initiator
  • ADVN dimethylvaleronitrile
  • the total amount of the IB-X/ADVN mixed solution was added to 40 g of micronized cellulose dispersion having a concentration of 1%.
  • the IB-X/ADVN mixed solution and the dispersion separated into two phases with high transparency.
  • the shaft of an ultrasonic homogenizer was inserted from the liquid surface of the upper phase in the liquid mixture in which the two phases were separated, and ultrasonic homogenizer treatment was performed for 3 minutes under the conditions of a frequency of 24 kHz and an output of 400 W.
  • the mixture After being treated with an ultrasonic homogenizer, the mixture turned into a cloudy emulsion.
  • one drop of the mixed liquid was dropped on a slide glass, sealed with a cover glass, and observed with an optical microscope, a large number of IB-X emulsion droplets of several ⁇ m or less were observed, and the dispersion was stabilized as an O/W emulsion. The situation was confirmed.
  • the supernatant was removed by decantation to collect the sediment, which was then repeatedly washed with pure water and methanol using a PTFE membrane filter with a pore size of 0.1 ⁇ m.
  • the composite particles thus purified and recovered were re-dispersed in pure water at a concentration of 1%, and the particle size was measured using a particle shape image analyzer (PITA-04, Seishin Enterprise Co., Ltd.). It was 1.3 ⁇ m.
  • PITA-04 Seishin Enterprise Co., Ltd.
  • FIGS. 5A and 5B SEM images of the dry powder are shown in FIGS. 5A and 5B.
  • FIG. 5A is an image at a magnification of 20,000 times
  • FIG. 5B is an image at a magnification of 50,000 times.
  • the polymerization reaction was carried out using the O/W type emulsion droplet as a template, so that a large number of spherical composite particles 5 derived from the shape of the emulsion droplet were obtained, and the particle size was uniform. It can be seen from FIG. 5A that once higher. As shown in FIG.
  • FIG. 5B shows an image of the composite particles after repeated filtration and washing. Therefore, in the composite particles 5 of the present example, the core particles 3 and the micronized cellulose 1 are bonded and inseparable. was shown to be in (Particle size distribution of composite particles)
  • FIG. 8 shows the results of measuring the particle size distribution of the dry powder with a particle size distribution analyzer LS-13320 manufactured by Beckman Coulter. The particle size distribution of Example 1, with an average particle size (median value) of 1.3 ⁇ m, was almost within the range of 10 ⁇ m or less, showing good agreement with the SEM image.
  • Example 2 Composite particles according to Examples 2 to 8 were produced in the same manner as in Example 1, except that the following organic onium compounds were used in place of the organic onium compound tetrabutylammonium chloride (TBACl) as the alkaline species. .
  • TBACl organic onium compound tetrabutylammonium chloride
  • Example 2 Tetrabutylammonium Bromide (TBABr)
  • Example 3 Tetrabutylammonium Hydroxide (TBAH)
  • Example 4 Tetramethylammonium Hydroxide (TMAH)
  • DMSA Dimethylstearylamine
  • Example 7 Stearylamine
  • Example 9 to 12 Composites according to Examples 9 to 12 were prepared in the same manner as in Example 3, except that the following amount of tetrabutylammonium hydroxide (TBAH), an organic onium compound, was added to the carboxy groups of the micronized cellulose. Particles were produced.
  • TBAH tetrabutylammonium hydroxide
  • Example 10 0.05 equivalents
  • Example 11 0.25 equivalents
  • Example 12 0.50 equivalents
  • Example 13 Composite particles according to Examples 13 to 15 were produced in the same manner as in Example 1, except that the following monomers/oligomers were used as core particle precursors instead of IB-X.
  • Example 13 Monofunctional Acrylate Isobornyl Acrylate (IB-XA)
  • Example 14 Monofunctional Vinyl Monomer p-Methylstyrene (p-MeSt)
  • Example 15 Difunctional Urethane Acrylate Oligomer (UA4200)
  • Example 16 Polycaprolactone (PCL, molecular weight 10,000) was used as a core particle precursor.
  • PCL polycaprolactone
  • a 20% MEK solution of PCL was added to the micronized cellulose dispersion. After heating this dispersion to 75° C. and subjecting it to an ultrasonic homogenizer treatment to form an O/W emulsion, in the fourth step, instead of performing a polymerization reaction, the droplets were solidified by cooling with ice water.
  • a composite particle according to Example 16 was produced under the same conditions as in Example 1 except for the above.
  • Example 17 The same as in Example 1, except that instead of TEMPO-oxidized CNF, CM-CNF obtained by performing the carboxymethylation (hereinafter also referred to as "CM-conversion") treatment described in Patent Document 2 was used. Composite particles according to Example 17 were produced under the conditions.
  • Example 18 In Example 1, instead of TEMPO oxidation, a phosphorylated CNF dispersion obtained by performing a phosphorylation treatment according to Non-Patent Document 1 cited as a prior art document was used. Composite particles according to Example 18 were produced under the same conditions as in .
  • the purified and collected composite particles were air-dried, and further vacuum-dried at room temperature of 25° C. for 24 hours to obtain dry powder.
  • the resulting dry powder was analyzed by X-ray photoelectron spectroscopy (XPS), nitrogen origin derived from TBACl was not detected, confirming that organic onium cations were removed.
  • the dry powder was again added to pure water and sonicated, showing good redispersion. All examples were subjected to the above treatment, and removal of organic onium cations and satisfactory redispersion were confirmed.
  • the fifth step was not performed.
  • Table 2 summarizes the contents of Examples and Comparative Examples.
  • Table 3 shows the evaluation results of Examples and Comparative Examples. Evaluation items and criteria are as follows.
  • emulsion stability After the O/W type emulsion obtained in the third step was allowed to stand for 24 hours, the O/W type emulsion was observed with an optical microscope, and the diameter of 100 droplets was measured. It was taken as the droplet diameter. If the emulsion stability is low, the droplet size becomes large due to instability such as creaming, aggregation, and coalescence of droplets. Emulsion stability was evaluated as follows. ⁇ (good): The maximum droplet diameter is 50 ⁇ m or less. x (bad): the maximum droplet size exceeds 50 ⁇ m. (Possibility of preparing composite particles) Whether composite particles can be produced was evaluated as follows.
  • ⁇ Yield of composite particles The yield of the composite particles was calculated by multiplying the weight (g) of the obtained composite particles/the resin weight (g) of the core particle precursor used for production ⁇ 100.
  • ⁇ Average particle size of composite particles The average particle size of the composite particles was determined using a particle shape image analyzer (PITA-04). When coarse resin lumps were present, they were removed and measured.
  • - Particle Size Uniformity of Composite Particles The particle size of 100 particles was measured by optical microscope observation, and the difference between the maximum and minimum particle sizes was calculated as the particle size range. The particle size uniformity of the composite particles was evaluated in the following two stages. ⁇ (good): The particle size range is 50 ⁇ m or less. ⁇ (bad): The particle size range exceeds 50 ⁇ m.
  • FIGS. 6A and 6B show SEM images of composite particles according to Example 10.
  • FIG. 6A The magnifications of FIGS. 6A and 6B are the same as in FIGS. 5A and 5B, respectively.
  • FIG. 6A many fine spherical particles with a size of several ⁇ m or less are produced as a whole, and as shown in FIG. It can be seen that Also, from the particle size distribution shown in FIG. 8, it can be confirmed that fine particles are produced in Example 10 as a whole.
  • various core precursors and core particles other than IB-X such as IB-XA, pMe-St, UA4200, and PCL, have high yields and particle diameters. Uniform composite particles could be obtained.
  • examples 17 and 18 even when using finely divided cellulose having various anionic functional groups other than TEMPO oxidation, such as CM and phosphate esterification, organic onium compounds/amines are added afterward. By a simple addition method, the surface of the micronized cellulose was hydrophobized, and composite particles with a uniform particle size could be obtained at a high yield.
  • Composite particles could also be obtained in Comparative Examples 1 to 7, but as shown in Table 3, the emulsion stability was low and the yield was lower than in Examples 1 to 18. It was large and the uniformity of particle size was low.
  • 7A and 7B show SEM images of dry powder of composite particles according to Comparative Example 2.
  • FIG. The magnifications of FIGS. 7A and 7B are similar to FIGS. 5A and 5B, respectively.
  • FIG. 7A in Comparative Example 1, a large number of coarsened composite particles exist and the particle size distribution is not uniform. In the coarsened composite particles, as shown in FIG. 7B, most of the surface of the core particles was exposed, and only a small amount of finely divided cellulose was bound.
  • Comparative Example 2 When the composite particles of Comparative Examples 1 to 8 were observed with an optical microscope, the maximum particle size was 50 ⁇ m or more, and there was a possibility that the cell of the particle size distribution meter PITA-04 was clogged, so particle size distribution measurement could not be performed. I didn't.
  • Comparative Example 2 coarse particles were removed, and the particle size distribution was evaluated using a particle size distribution meter. That is, the particle size distribution of Comparative Example 2 shown in FIG. 8 is the particle size distribution after removing coarse particles. As shown in FIG. 8, the particle size of Comparative Example 2 tended to be larger than those of Examples 1 and 10, and the variation in particle size was also large.
  • the composite particles according to the present invention have favorable effects from the viewpoint of industrial implementation, such as improving the addition efficiency as an additive and the efficiency of kneading with a resin, and contributing to cost reduction from the viewpoint of improving transportation efficiency and preventing spoilage. can get.
  • the composite particles can be used for coloring materials, adsorbents, cosmetic pigments, sustained-release materials, deodorants, antibacterial medical materials, personal care products, etc.
  • Antibacterial products for supplies, packaging materials, dye-sensitized solar cells, photoelectric conversion materials, photothermal conversion materials, heat shielding materials, optical filters, Raman enhancement elements, image display elements, magnetic powders, catalyst carriers, drug delivery systems, etc. can be applied to

Landscapes

  • Chemical & Material Sciences (AREA)
  • Health & Medical Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Medicinal Chemistry (AREA)
  • Polymers & Plastics (AREA)
  • Organic Chemistry (AREA)
  • Dispersion Chemistry (AREA)
  • Processes Of Treating Macromolecular Substances (AREA)
  • Compositions Of Macromolecular Compounds (AREA)
  • Biological Depolymerization Polymers (AREA)
  • Polysaccharides And Polysaccharide Derivatives (AREA)

Abstract

L'invention concerne un procédé pour la production d'une particule composite, comprenant : une première étape de fibrillation d'un matériau de départ cellulosique dans un solvant de dispersion pour obtenir une dispersion de cellulose de taille microfine dans laquelle de la cellulose de taille microfine est dispersée ; une deuxième étape d'addition d'un composé d'onium organique ou d'une amine à la dispersion de cellulose de taille microfine pour obtenir une dispersion de cellulose de taille microfine contenant une cellulose de taille microfine liée à des ions, dans laquelle un ion onium organique ou un ion ammonium est lié ; une troisième étape de stabilisation, sous forme d'une émulsion dans la dispersion de cellulose de taille microfine liée aux ions, de gouttelettes contenant un précurseur de particule de coeur ; et une quatrième étape de solidification du précurseur de particule de coeur pour le convertir en une particule de coeur et obtenir une particule composite dans laquelle la particule de coeur est revêtue d'une cellulose de taille microfine qui est liée de façon inséparable à la particule de coeur.
PCT/JP2022/022996 2021-06-28 2022-06-07 Procédé pour la production d'une particule composite et particule composite Ceased WO2023276585A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2021-106675 2021-06-28
JP2021106675A JP2023005014A (ja) 2021-06-28 2021-06-28 複合粒子の製造方法および複合粒子

Publications (1)

Publication Number Publication Date
WO2023276585A1 true WO2023276585A1 (fr) 2023-01-05

Family

ID=84690264

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2022/022996 Ceased WO2023276585A1 (fr) 2021-06-28 2022-06-07 Procédé pour la production d'une particule composite et particule composite

Country Status (2)

Country Link
JP (1) JP2023005014A (fr)
WO (1) WO2023276585A1 (fr)

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2010059304A (ja) * 2008-09-03 2010-03-18 Teijin Ltd エポキシ樹脂コンポジット
JP2013014741A (ja) * 2011-06-07 2013-01-24 Kao Corp 樹脂改質用添加剤及びその製造方法
WO2018123985A1 (fr) * 2016-12-27 2018-07-05 花王株式会社 Composition de résine
JP2019038949A (ja) * 2017-08-25 2019-03-14 国立研究開発法人森林研究・整備機構 複合粒子の製造方法とその製造方法で得られる複合粒子
WO2019135384A1 (fr) * 2018-01-05 2019-07-11 凸版印刷株式会社 Particules composites, procédé de production de particules composites, poudre sèche et composition de résine pour moulage
WO2019208802A1 (fr) * 2018-04-27 2019-10-31 凸版印刷株式会社 Particules composites, procédé de production de particules composites, poudre sèche, composition destinée à être appliquée sur la peau et procédé de production d'une composition destinée à être appliquée sur la peau
WO2020170995A1 (fr) * 2019-02-19 2020-08-27 凸版印刷株式会社 Particules composites, composition de particules composites et procédé de production de composition de particules composites
WO2021002290A1 (fr) * 2019-07-01 2021-01-07 凸版印刷株式会社 Particule composite et procédé de production d'une particule composite

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2010059304A (ja) * 2008-09-03 2010-03-18 Teijin Ltd エポキシ樹脂コンポジット
JP2013014741A (ja) * 2011-06-07 2013-01-24 Kao Corp 樹脂改質用添加剤及びその製造方法
WO2018123985A1 (fr) * 2016-12-27 2018-07-05 花王株式会社 Composition de résine
JP2019038949A (ja) * 2017-08-25 2019-03-14 国立研究開発法人森林研究・整備機構 複合粒子の製造方法とその製造方法で得られる複合粒子
WO2019135384A1 (fr) * 2018-01-05 2019-07-11 凸版印刷株式会社 Particules composites, procédé de production de particules composites, poudre sèche et composition de résine pour moulage
WO2019208802A1 (fr) * 2018-04-27 2019-10-31 凸版印刷株式会社 Particules composites, procédé de production de particules composites, poudre sèche, composition destinée à être appliquée sur la peau et procédé de production d'une composition destinée à être appliquée sur la peau
WO2020170995A1 (fr) * 2019-02-19 2020-08-27 凸版印刷株式会社 Particules composites, composition de particules composites et procédé de production de composition de particules composites
WO2021002290A1 (fr) * 2019-07-01 2021-01-07 凸版印刷株式会社 Particule composite et procédé de production d'une particule composite

Also Published As

Publication number Publication date
JP2023005014A (ja) 2023-01-18

Similar Documents

Publication Publication Date Title
JP7501712B2 (ja) 複合粒子の製造方法
JP7234590B2 (ja) 塗工用組成物
US20230320972A1 (en) Composite particles, method of producing composite particles and dry powder of composite particles, skin application composition and method of producing the skin application composition
CN113454146B (zh) 复合粒子、复合粒子组合物及复合粒子组合物的制造方法
JP7472446B2 (ja) 機能性複合粒子及びその製造方法
JP7601352B2 (ja) 複合粒子の製造方法
JP7067246B2 (ja) 複合粒子、複合粒子の製造方法および乾燥粉体
JP7420336B2 (ja) 複合粒子の製造方法
JP7298283B2 (ja) 徐放性複合粒子、成形体および徐放性複合粒子の製造方法
WO2023276585A1 (fr) Procédé pour la production d'une particule composite et particule composite
JP7424098B2 (ja) 道路舗装用組成物および成形体
JP7581650B2 (ja) 複合粒子および複合粒子の製造方法
JP7753783B2 (ja) 複合粒子及び導電性粒子、導電性粒子の製造方法、導電性接着剤
JP2024027834A (ja) 複合粒子及び複合粒子の製造方法
JP7342350B2 (ja) 皮膚塗布用組成物および皮膚塗布用組成物の製造方法
JP2023163358A (ja) 蛍光色素吸着繊維、蛍光色素吸着複合粒子、成形体、蛍光色素吸着繊維の製造方法及び蛍光色素吸着複合粒子の製造方法
JP2023094067A (ja) 複合粒子
JP2023021630A (ja) 複合粒子および複合粒子の製造方法
JP2020186338A (ja) フッ素含有ポリマー複合粒子、フッ素含有ポリマー複合粒子の製造方法、乾燥粉体及び研磨剤
JP2023094123A (ja) 複合粒子
JP2023123006A (ja) 複合粒子
JP2022065470A (ja) 溶剤溶解性複合粒子、溶剤溶解性複合粒子の製造方法および溶剤溶解性複合粒子混合樹脂組成物

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 22832742

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 22832742

Country of ref document: EP

Kind code of ref document: A1