JP2020006369A - Manufacturing method of particles - Google Patents

Abstract

To prevent a decline in a collection rate of particles caused by generation of fibrous product materials, etc. as a molten body is solidified in a fibrous state before turned into particles or a fused state, when the molten body obtained by mixing a molten resin and a liquefied carbon dioxide is discharged from a nozzle, and the discharged molten body is suddenly cooled down.SOLUTION: A manufacturing method of particles sprays a molten body while supplying a second compressive fluid containing nitrogen. As the second compressive fluid contains nitrogen, a temperature drop by the Joule-Thompson effect can be mitigated accompanying a pressure change when the molten body is sprayed. Thereby, the solidification of the sprayed molten body before turning into particles can be prevented, so that an effect of improvement of a collection rate of particles can be achieved.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a method for producing particles using a compressible fluid.

  BACKGROUND ART Conventionally, various particulate products have been manufactured by processing a resin based on its physical properties. For example, there is known a method for producing a toner as an example of powder by melt-kneading a composition comprising a resin and an additive, cooling, solidifying, pulverizing, and classifying (see Patent Document 1). However, when a toner is produced by this method, there is a problem that fine powder generated by pulverization is mixed into the toner, and the basic characteristics of the toner such as chargeability, fixability and heat-resistant storage stability are deteriorated.

  As a method for producing a toner without pulverizing a resin or the like, a method of emulsifying and dispersing a colored resin solution is known (see Patent Document 2). According to this method, a colored resin solution comprising a polyester resin, a colorant, and a water-insoluble organic solvent is emulsified and dispersed in water to form an O / W emulsion, and then the organic solvent is removed to form the colored resin particles. Formed and aggregated to obtain toner particles. However, when a toner is manufactured by this method, there is a problem that the burden on the environment is increased because an organic solvent is used.

  As a method for producing a toner without using an organic solvent, a method using liquefied carbon dioxide has been proposed (see Patent Document 3). According to this method, a molten polyester resin and liquefied carbon dioxide are mixed with a static mixer, and the resulting mixture is discharged from a nozzle attached to the tip of the static mixer under an atmosphere of atmospheric pressure and 20 ° C., and expanded under reduced pressure. Then, a toner is manufactured.

  However, when a melt as a mixture obtained by mixing a molten resin and liquefied carbon dioxide is discharged from a nozzle, the discharged melt is rapidly cooled. As a result, the melt solidifies in a fibrous state or a coalesced state before being formed into particles, so that the generation of fibrous products or the like causes a problem that the particle recovery rate is reduced.

  The invention according to claim 1 includes a melting step of bringing the first compressive fluid into contact with the pressurized plastic material to melt the pressurized plastic material, and adding a nitrogen to the melt obtained by melting the pressurized plastic material. A granulating step of injecting and granulating the melt while supplying a second compressive fluid including the following.

  As described above, according to the method for producing particles of the present invention, the melt is injected while the second compressive fluid containing nitrogen is supplied. By including nitrogen in the second compressive fluid, a decrease in temperature due to the Joule-Thomson effect caused by a pressure change when the melt is injected can be reduced. Thereby, since it is possible to suppress the injected melt from solidifying in a state before the particles are formed into particles, there is an effect that the recovery rate of the particles is improved.

It is a figure which shows the relationship between the glass transition temperature (vertical axis) and pressure (horizontal axis) of a pressure plastic material. FIG. 2 is a general phase diagram showing the state of a substance with respect to temperature and pressure. FIG. 4 is a phase diagram for defining a range of a compressible fluid. It is a schematic diagram which shows an example of a particle manufacturing apparatus. FIG. 1 is a schematic diagram illustrating an image forming apparatus according to an embodiment of the present disclosure. It is a schematic diagram which shows an example of a particle manufacturing apparatus.

[First Embodiment]
Hereinafter, a first embodiment of the present invention will be described. In the method for producing particles according to the present embodiment, the first compressive fluid is brought into contact with the pressurized plastic material to melt the pressurized plastic material, and while supplying the second meltable fluid to the obtained melt, The melt is sprayed and granulated. In the present embodiment, “melt” means a state in which a raw material such as a pressure plastic material is swollen and plasticized and liquefied by contact with a compressive fluid. In the present embodiment, the raw material is a material from which the particles are manufactured, and means a material that is a constituent component of the particles.

<< Raw materials >>
First, raw materials such as a pressure plastic material used in the manufacturing method of the present embodiment will be described.

<Pressure plastic material>
First, the pressure plastic material will be described with reference to FIG. FIG. 1 is a diagram showing the relationship between the glass transition temperature (vertical axis) and the pressure (horizontal axis) of a pressure-plastic material. In the present embodiment, the pressure-plastic material is a material having a property that the glass transition temperature (Tg) is reduced by applying pressure, and more specifically, the plasticity is obtained by applying pressure without applying heat. Means the material to be converted. The pressure plastic material plasticizes at a temperature below the glass transition temperature of the pressure plastic material at atmospheric pressure when pressure is applied, for example, by contact with a compressible fluid.

  FIG. 1 shows the relationship between the glass transition temperature (vertical axis) and the pressure (horizontal axis) of polystyrene as an example of a pressure plastic material in the presence of carbon dioxide. As shown in FIG. 1, there is a correlation between the glass transition temperature and pressure of polystyrene, and the slope is negative. Materials such as polystyrene in which the slope of the change in the glass transition temperature with respect to the applied pressure is negative can be referred to as a pressure plastic material. This inclination differs depending on the type, composition, molecular weight, and the like of the thermoplastic material. This slope is, for example, −9 ° C./MPa for polystyrene, −9 ° C./MPa for styrene-acrylic resin, −8 ° C./MPa for amorphous polyester resin, −2 ° C./MPa for crystalline polyester. MPa, -8 ° C / MPa for a polyol resin, -7 ° C / MPa for a urethane resin, -11 ° C / MPa for a polyarylate resin, and -10 ° C / MPa for a polycarbonate resin. In addition, this inclination can be determined based on the measurement result when measuring the glass transition temperature while changing the pressure using a C-80 high-pressure calorimeter device manufactured by SETARAM. In this case, the sample is set in the high-pressure measurement cell, and after replacing the inside of the cell with carbon dioxide, the glass transition temperature can be measured by applying a predetermined pressure. Further, the inclination can be determined based on the amount of change in the glass transition temperature when the pressure is changed from the atmospheric pressure (0.1 MPa) to 10 MPa.

  The gradient of the change of the glass transition temperature with respect to the pressure is preferably -1 ° C / MPa or less, more preferably -5 ° C / MPa or less, and even more preferably -10 ° C / MPa or less. There is no limit on the lower limit of the slope. On the other hand, if the gradient is larger than -1 ° C / MPa, the plasticization becomes insufficient when pressure is applied without applying heat, and the melt cannot be reduced in viscosity. There is. As the pressure plastic material, a material having a viscosity of 500 mPa · s or less under a condition of 30 MPa or less is preferable. In this case, the viscosity may be reduced to 500 mPa · s or less under the condition of 30 MPa or less by applying heat of the melting point or less at normal pressure to the pressure plastic material.

  The pressure plastic material is not particularly limited and can be appropriately selected depending on the intended purpose.For example, polyester resin, vinyl resin, urethane resin, polyol resin, polyamide resin, epoxy resin, rosin, modified rosin, terbene resin, Examples include phenolic resins, aliphatic or alicyclic hydrocarbon resins, aromatic petroleum resins, chlorinated paraffins, paraffin waxes, polyethylene, and polypropylene. These may be used alone or in combination of two or more.

  The polyester resin is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include a modified polyester, an unmodified polyester, an amorphous polyester, and a crystalline polyester.

  As the polyol resin, a polyether polyol resin having an epoxy skeleton is used, and (i) an epoxy resin, (ii) an alkylene oxide adduct of a dihydric phenol or its glycidyl ether, and (iii) active hydrogen that reacts with an epoxy group. A polyol resin or the like obtained by reacting a compound having the same is preferably used. The vinyl resin is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include polymers of styrene such as polystyrene, poly-p-chlorostyrene, and polyvinyltoluene and their substituted polymers; styrene-p-chlorostyrene Copolymer, styrene-propylene copolymer, styrene-vinyltoluene copolymer, styrene-vinylnaphthalene copolymer, styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer, styrene-butyl acrylate Copolymer, styrene-octyl acrylate copolymer, styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, styrene-butyl methacrylate copolymer, styrene-α-chloromethyl methacrylate copolymer Coal, styrene-acrylonitrile copolymer, styrene-bi Styrene copolymers such as methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-acrylonitrile-indene copolymer, styrene-maleic acid copolymer and styrene-maleic acid ester copolymer Coalescing; polymethyl methacrylate, polybutyl methacrylate, polyvinyl chloride, polyvinyl acetate, vinyl propionate, (meth) acrylamide, vinyl methyl ether, vinyl ethyl ether, vinyl isobutyl ether, vinyl methyl ketone, N-vinyl pyrrolidone, N- Examples thereof include polymers of monomers such as vinylpyridine and butadiene, copolymers of two or more of these monomers, and mixtures thereof.

<Other raw materials>
In the production method of the present embodiment, other raw materials can be used in combination with the above-described thermoplastic resin in accordance with the characteristics and processability of the produced particles. Hereinafter, raw materials such as a colorant, a surfactant, a dispersant, a release agent, a charge control agent, and a crystalline polyester will be described on the assumption that the particles produced according to the present embodiment are toners.

(Colorant)
The colorant is not particularly limited, and can be appropriately selected from known pigments and dyes according to the purpose. The addition amount of these coloring agents is not particularly limited and can be appropriately selected according to the degree of coloring, but is preferably 1 part by mass or more and 50 parts by mass or less with respect to 100 parts by mass of the pressure plastic material. These colorants may be used alone or in combination of two or more.

  Examples of the coloring agent include carbon black, nigrosine dye, iron black, naphthol yellow S, Hansa yellow (10G, 5G, G), cadmium yellow, yellow iron oxide, ocher, graphite, titanium yellow, and polyazo yellow. , Oil Yellow, Hansa Yellow (GR, A, RN, R), Pigment Yellow L, Benzidine Yellow (G, GR), Permanent Yellow (NCG), Vulcan Fast Yellow (5G, R), Tartrazine Lake, Quinoline Yellow Lake , Anthrazan Yellow BGL, Isoindolinone Yellow, Bengala, Lead Tan, Lead Vermilion, Cadmium Red, Cadmium Mercury Red, Antimony Vermilion, Permanent Red 4R, Para Red, Phisaed Red, Parachlor Ortho Nitroaniline Red, Risor Fast Curlet G, Brilliant Fast Scarlet, Brilliant Carmine BS, Permanent Red (F2R, F4R, FRL, FRLL, F4RH), Fast Scarlet VD, Belcan Fast Rubin B, Brilliant Scarlet G, Lysole Rubin GX, Permanent Red F5R, Brilliant Carmine 6B, Pigment Scarlett 3B, Bordeaux 5B, Toluidine Maroon, Permanent Bordeaux F2K, Helio Bordeaux BL, Bordeaux 10B, Bon Maroon Light, Bon Maroon Museum, Eosin Lake, Rhodamine Lake B, Rhodamine Lake Y, Alizarin Lake, Thio Indigo Red B, Thioindigo maroon, oil red, quinacridone red, pyrazolone red, polyazo red, chrome vermilli , Benzidine orange, perinone orange, oil orange, cobalt blue, cerulean blue, alkali blue lake, peacock blue lake, victoria blue lake, metal-free phthalocyanine blue, phthalocyanine blue, fast sky blue, indanthrene blue (RS, BC ), Indigo, ultramarine, navy blue, anthraquinone blue, fast violet B, methyl violet lake, cobalt violet, manganese purple, dioxane violet, anthraquinone violet, chrome green, zinc green, chromium oxide, pyridian, emerald green, pigment green B, naphthol Green B, Green Gold, Acid Green Lake, Malachite Green Lake, Phthalocyanine Green, Anthraquinone Green, titanium oxide, zinc white, lithobon, and the like.

  Examples of the dye include C.I. I. C. SOLVENT YELLOW (6, 9, 17, 31, 35, 100, 102, 103, 105); I. SOLVENT ORANGE (2, 7, 13, 14, 66), C.I. I. C. SOLVENT RED (5, 16, 17, 18, 19, 22, 23, 143.145, 146, 149, 150, 151, 157, 158), C.I. I. SOLVENT VIOLET (31, 32, 33, 37), C.I. I. SOLVENT BLUE (22, 63, 78, 83-86, 191, 194, 195, 104), C.I. I. SOLVENT GREEN (24, 25), C.I. I. SOLVENT BROWN (3, 9). Commercially available dyes include Aizen SOT dyes Yellow-1,3,4, Orange-1,2,3, Scarlet-1, Red-1,2,3, Brown-2 and Blue- made by Hodogaya Chemical Co., Ltd. 1,2, Violet-1, Green-1,2,3, Black-1,4,6,8; Sudan dye Yellow-146,150, Orange-220, Red-290,380,460, manufactured by BASF. Blue-670: Diaresin Yellow-3G, F, H2G, HG, HC, HL, Orange-HS, G, Red-GG, S, HS, A, K, H5B, Violet-D, Blue- J, G, N, K, P, H3G, 4G, Green-C, Brown-A; Oil color YEllow manufactured by Orient Chemical Industries, Ltd. 3G, GG-S, # 105, Orange-PS, PR, # 201, Scarlet- # 308, Red-5B, Brown-GR, # 416, Green-BG, # 502, Blue-BOS, IIN, Black-HBB , # 803, EB, EX; Sumiplast Blue GP, OR, Red FB, 3B, Yellow FL7G, GC manufactured by Sumitomo Chemical Co., Ltd .; Kayalon polyester black EX-SF300, Kayaset Red-B, manufactured by Nippon Kayaku Co., Ltd. Blue A-2R, and the like.

(Surfactant)
When the particles produced by the production method of the present embodiment are toners, it is preferable that the raw material contains a surfactant. The surfactant is not particularly limited as long as it has a portion having an affinity for the compressible fluid and a portion having an affinity for the toner in the same molecule, and may be appropriately selected depending on the purpose. it can. When the first compressive fluid is carbon dioxide, the surfactant may be a fluorine-based surfactant or a silicone-based surfactant; a compound having a bulky functional group such as a carbonyl group, a short hydrocarbon group, or a propylene oxide group. And the like. Among these, fluorine surfactants, silicone surfactants, carbonyl group-containing compounds, and polyethylene glycol (PEG) group-containing compounds are preferred. These surfactants may be oligomers or polymers.

  As the fluorinated surfactant, a compound having a perfluoroalkyl group having 1 to 30 carbon atoms is suitably used. Among these, a high molecular weight fluorine-based surfactant is preferable from the viewpoints of surface activity, charging performance when a toner is used, and durability. Here, an example of the structural unit of the fluorine-based surfactant is shown in Formulas (1-1) and (1-2).

R ₁ in the formulas (1-1) and (1-2) represents a hydrogen atom or a lower alkyl group having 1 to 4 carbon atoms (eg, a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group) , Sec-butyl group, tert-butyl group, etc.). R ₂ in the formula (1-1) represents an alkylene group (for example, a methylene group, an ethylene group, a propylene group, an isoprene group, a 2-hydroxypropylene group, a butylene group, a 2-hydroxybutylene group, and the like). Rf in the formulas (1-1) and (1-2) represents a perfluoroalkyl group or a perfluoroalkenyl group having 1 to 30 carbon atoms. Among them, a fluorine-based surfactant in which R ₁ is a hydrogen atom or a methyl group, R ₂ is a methylene group or an ethylene group, and Rf is a perfluoroalkyl group having 7 to 10 carbon atoms is preferable. Note that an oligomer or a polymer is formed by bonding a plurality of structural units of the formulas (1-1) and (1-2). In this case, a homopolymer, a block copolymer, a random copolymer, or the like may be formed in consideration of affinity with the toner. Each terminal of the oligomer or polymer is, but not limited to, a hydrogen atom.

  The silicone surfactant is not particularly limited as long as it is a compound having a siloxane bond, and may be a low molecular compound or a high molecular compound. Among these, compounds containing a polydimethylsiloxane (PDMS) group represented by the structural formula (2) are preferable. These may be compounds such as a homopolymer, a block copolymer, and a random copolymer in consideration of the affinity with the toner.

In the formula (2), R _{1 ″} represents a hydrogen atom, a lower alkyl group having 1 to 4 carbon atoms, n represents the number of repetitions, and R _{2 ″} represents a hydrogen atom, a hydroxyl group, having 1 to 10 carbon atoms. Represents an alkyl group.

  The carbonyl group-containing compound is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include aliphatic polyesters, polyacrylates, and acrylic resins. The PEG group-containing compound is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include PEG group-containing polyacrylate and polyethylene glycol resin.

  These surfactants polymerize vinyl monomers such as Rf group-containing vinyl monomers, PDMS group-containing vinyl monomers, and PEG group-containing vinyl monomers, or copolymerize these vinyl monomers with other vinyl monomers. To obtain. Examples of the vinyl monomer include a styrene monomer, an acrylate monomer, and a methacrylate monomer. Many of these vinyl monomers are commercially available, and can be appropriately used according to the purpose. In addition, as the surfactant, those in which an Rf group, a PDMS group, or a PEG group is a main chain of an oligomer or a polymer, and a COOH group, an OH group, an amino group, a pyrrolidone skeleton, or the like is introduced into a side chain can be used. .

  The fluorine-containing surfactant is synthesized by polymerizing a fluorine-based vinyl monomer in a fluorine-based solvent such as HCFC225. Further, in order to reduce the environmental load, a fluorine-based vinyl monomer can be polymerized using supercritical carbon dioxide as a solvent instead of HCFC225. A large number of raw materials having a structure similar to the compound having a perfluoroalkyl group are commercially available (for example, see the catalog of ADAMAX), and various surfactants can be obtained by using them. For details of the production method, see Fluoropolymer Handbook (edited by Takaomi Satokawa, published by Nikkan Kogyo Shimbun). 730-P. 732 is used.

  Further, the silicone surfactant can be obtained by polymerizing a vinyl polymerizable monomer as a raw material. In this case, a supercritical fluid (especially supercritical carbon dioxide) may be used as the solvent. A large number of compounds having a structure similar to polydimethylsiloxane are commercially available (for example, see the catalog of ADAMAX), and a silicone-based surfactant can be obtained by using them. In particular, a silicon-containing compound (trade name: MONASIL-PCA, manufactured by Croda) exhibits good granulation properties.

  The content of the surfactant in the raw material of the toner is preferably 0.01% by mass to 30% by mass, and more preferably 0.1% by mass to 20% by mass.

(Dispersant)
The dispersant is not particularly limited and may be appropriately selected depending on the purpose. Examples thereof include organic fine particles and inorganic fine particles. Among these, acrylic-modified inorganic fine particles, silicone-modified inorganic fine particles, fluorine-modified inorganic fine particles, fluorinated organic fine particles, silicone-based organic fine particles, and the like are preferable, and acrylic-modified inorganic fine particles are more preferable. It is preferable that these dispersants melt in the compressible fluid.

  Examples of the organic fine particles include silicone-modified and fluorine-modified acrylic fine particles that are insoluble in a supercritical fluid. Examples of the inorganic fine particles include polyphosphate metal salts such as calcium phosphate, magnesium phosphate, aluminum phosphate, and zinc phosphate; carbonates such as calcium carbonate and magnesium carbonate; and inorganic salts such as calcium metasilicate, calcium sulfate, and barium sulfate. And inorganic oxides such as calcium hydroxide, magnesium hydroxide, aluminum hydroxide, silica, titanium oxide, bentonite, and alumina. Among these, silica is preferable.

  Examples of the acrylic-modified inorganic fine particles include, for example, those obtained by modifying the residual OH groups present on the surface of the inorganic fine particles with a silane coupling agent containing a fluorine atom. The following reaction formula shows an example in the case where the surface of silica is modified using 3- (Trimethyoxysil) propymethacrylate.

The acrylic-modified silica obtained by this method has a high affinity for supercritical carbon dioxide on the silica side and a high affinity for the toner on the acrylate side. If the purpose is the same, the surface modification may be performed by another method without using the method based on the reaction formula. Next, specific examples of the silane coupling agent containing a fluorine atom are shown below.
(4-1) CF ₃ (CH ₂ ) ₂ SiCl ₃
(4-2) CF ₃ (CF ₂ ) ₅ SiCl ₃
(4-3) CF ₃ (CF ₂ ) ₅ (CH ₂ ) ₂ SiCl ₃
(4-4) CF ₃ (CF ₂ ) ₇ (CH ₂ ) ₂ SiCl ₃
(4-5) CF ₃ (CF ₂ ) ₇ CH ₂ CH ₂ Si (OCH ₃ ) _{3
(4-6) CF 3 (CF 2} ) 7 (CH 2) 2 Si (CH 3) Cl 2
_{(4-7) CF 3 (CH 2} ) 2 Si (OCH 3) 3
_{(4-8) CF 3 (CH 2} ) 2 Si (CH 3) (OCH 3) 2
_{(4-9) CF 3 (CF 2} ) 3 (CH 2) 2 Si (OCH 3) 3
_{(4-10) CF 3 (CF 2} ) 5 CONH (CH 2) 2 Si (OC 2 H 5) 3
(4-11) CF ₃ (CF ₂ ) ₄ COO (CH ₂ ) ₂ Si (OCH ₃ ) _{3
(4-12) CF 3 (CF 2} ) 7 (CH 2) 2 Si (OCH 3) 3
_{(4-13) CF 3 (CF 2} ) 7 (CH 2) 2 Si (CH 3) (OCH 3) 2
_{(4-14) CF 3 (CF 2} ) 7 SO 2 NH (CH 2) 3 Si (OC 2 H 5) 3
_{(4-15) CF 3 (CF 2} ) 8 (CH 2) 2 Si (OCH 3) 3

  The content of these dispersants in the raw material of the toner is preferably 0.1% by mass to 30% by mass, and more preferably 0.2% by mass to 20% by mass. The dispersant is preferably used alone, but other surfactants may be used in combination in consideration of control of toner particle size and toner charging performance.

(Release agent)
The release agent is not particularly limited and can be appropriately selected from known ones according to the purpose. For example, waxes and the like are preferred. Examples of the waxes include low molecular weight polyolefin waxes, synthetic hydrocarbon waxes, natural waxes, petroleum waxes, higher fatty acids and metal salts thereof, higher fatty acid amides, and various modified waxes thereof. These may be used alone or in combination of two or more.

  Examples of the low molecular weight polyolefin wax include a low molecular weight polyethylene wax, a low molecular weight polypropylene wax and the like. Examples of the synthetic hydrocarbon wax include Fischer-Tropsch wax. Examples of natural waxes include beeswax, carnauba wax, candelilla wax, rice wax, montan wax and the like. Examples of petroleum waxes include paraffin wax, microcrystalline wax and the like. Examples of higher fatty acids and metal salts thereof include stearic acid, palmitic acid, myristic acid, zinc stearate, calcium stearate and the like.

  The melting points of these release agents are not particularly limited and may be appropriately selected depending on the purpose. However, the melting points are preferably from 40 ° C to 160 ° C, more preferably from 50 ° C to 120 ° C, and from 60 ° C to 90 ° C. C. or lower is particularly preferred. If the melting point is lower than 40 ° C., the heat-resistant storage stability may be reduced. If the melting point is higher than 160 ° C., cold offset may easily occur during fixing at a low temperature, and the paper may be wound around a fixing machine. May occur. The cold offset means that in the heat roller fixing method, a part of the toner image is removed by electrostatic attraction because the vicinity of the interface between the toner and the paper is not sufficiently melted, and is also referred to as a low-temperature offset.

  The addition amount of these release agents is not particularly limited and may be appropriately selected depending on the intended purpose; however, the amount is preferably 1 part by mass or more and 20 parts by mass or less, and more preferably 3 parts by mass or more with respect to 100 parts by mass of the thermoplastic material. 15 parts by mass or less is more preferable. If the amount of the release agent is less than 1 part by mass, the effect of the release agent may not be sufficiently obtained, and if it is more than 20 parts by mass, the heat-resistant storage stability may decrease.

(Charge control agent)
The charge control agent is not particularly limited and can be appropriately selected from known ones according to the purpose.However, when a colored one is used, the color tone may change, and therefore a material that is colorless or nearly white is used. preferable. Examples of such a charge control agent include a nigrosine dye, a triphenylmethane dye, a chromium-containing metal complex dye, a molybdate chelate pigment, a rhodamine dye, an alkoxy amine, and a quaternary ammonium salt (fluorine-modified quaternary ammonium salt). Salts, alkyl amides, phosphorus simple substance or compound thereof, tungsten simple substance or compound thereof, fluorine-based activator, metal salt of salicylic acid, metal salt of salicylic acid derivative and the like. Among these, salicylic acid metal salts and metal salts of salicylic acid derivatives are preferred. These may be used alone or in combination of two or more. The metal used for the metal salt is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include aluminum, zinc, titanium, strontium, boron, silicon, nickel, iron, chromium, and zirconium. Can be

  Commercially available charge control agents include, for example, quaternary ammonium salt Bontron P-51, oxynaphthoic acid-based metal complex E-82, salicylic acid-based metal complex E-84, and phenol-based condensate E-89. (Above, manufactured by Orient Chemical Industry Co., Ltd.), TP-302 and TP-415 of quaternary ammonium salt molybdenum complex, TN-105 of salicylic acid metal complex (above, manufactured by Hodogaya Chemical Industry Co., Ltd.), and quaternary ammonium salt Copy Charge PSY VP2038, Copy Blue PR of a triphenylmethane derivative, Copy Charge NEG VP2036 of a quaternary ammonium salt, Copy Charge NX VP434 (all from Hoechst), LRA-901, LR-147 of a boron complex (Nippon Carlit) Co., Ltd.), quinacridone, azo pigments, other sulfonic acid groups, carbo And high molecular compounds having a functional group such as a xyl group or a quaternary ammonium salt.

  The addition amount of these charge control agents is not particularly limited and can be appropriately selected depending on the purpose. However, the amount is preferably 0.5 parts by mass or more and 5 parts by mass or less, and more preferably 1 part by mass with respect to 100 parts by mass of the thermoplastic material. And more preferably 3 parts by mass or less. If the addition amount is less than 0.5 parts by mass, the charging characteristics of the toner may be deteriorated. If the addition amount exceeds 5 parts by mass, the chargeability of the toner becomes too large, and the effect of the main charge control agent is reduced. As a result, the electrostatic attraction force with the developing roller increases, which may cause a decrease in developer fluidity and a decrease in image density.

(Crystalline polyester)
The crystalline polyester is not particularly limited and can be appropriately selected from known polyesters according to the purpose.However, in terms of excellent low-temperature fixability, the molecular weight distribution is sharp and the molecular weight is low. Is preferred. In such a crystalline polyester, in the distribution of the molecular weight M by GPC of the soluble portion of o-dichlorobenzene, the peak position in the molecular weight distribution diagram in which the horizontal axis is log (M) and the vertical axis is mass% is 3 The peak half width is 1.5 or less, the weight average molecular weight (Mw) is 1,000 or more and 30,000 or less, and the number average molecular weight (Mn) is 500 or more and 6, 000 or less and Mw / Mn of 2 or more and 8 or less are more preferable.

The melting point and the F1 / 2 temperature of the crystalline polyester are preferably low as long as the heat-resistant storage stability is not deteriorated, and the DSC endothermic peak temperature is more preferably 50 ° C. or more and 150 ° C. or less. Here, the F1 / 2 temperature was measured using an elevated flow tester CFT-500 (manufactured by Shimadzu Corporation) and the sample was 1 cm ² under the conditions of a die diameter of 1 mm, a pressure of 10 kg / cm ² , and a heating rate of 3 ° C./min. Is measured at a temperature corresponding to a half of the time from the outflow start point to the outflow end point at the time of melting out. If the melting point and the F1 / 2 temperature are less than 50 ° C., the heat-resistant storage stability deteriorates, and blocking tends to occur at the temperature inside the developing device. Can not be obtained.

  The acid value of the crystalline polyester is preferably 5 mgKOH / g or more, more preferably 10 mgKOH / g or more, in view of affinity between paper and resin and low-temperature fixability. The acid value of the crystalline polyester is preferably 45 mgKOH / g or less from the viewpoint of hot offset property. The hydroxyl value of the crystalline polyester is preferably from 0 mgKOH / g to 50 mgKOH / g, more preferably from 5 mgKOH / g to 50 mgKOH / g, from the viewpoint of low-temperature fixability and charging characteristics.

  The amount of the crystalline polyester to be added is not particularly limited and may be appropriately selected depending on the purpose. However, the amount is preferably from 0 parts by mass to 900 parts by mass, and more preferably from 0.5 parts by mass to 100 parts by mass of the thermoplastic material. It is more preferably at least 500 parts by mass and particularly preferably at least 1 part by mass and up to 100 parts by mass. If the amount is less than 1 part by mass, the low-temperature fixing property may not be exhibited, and if it exceeds 900 parts by mass, the hot offset property may decrease.

(Other components)
Other components that may be used together with the pressure plastic material include a fluidity improver, a cleaning improver, and the like. The fluidity improver means a substance which can be subjected to a surface treatment to increase the hydrophobicity of the toner and prevent deterioration of the fluidity and charging properties even under high humidity. Examples of the fluidity improver include a silane coupling agent, a silylating agent, a silane coupling agent having an alkyl fluoride group, an organic titanate-based coupling agent, an aluminum-based coupling agent, a silicone oil, and a modified silicone oil. Is exemplified.

  The cleaning property improving agent means one added to the toner composition in order to remove the developer after transfer remaining on the photoreceptor or the primary transfer medium. Examples of such a cleaning improver include fatty acid metal salts such as zinc stearate, calcium stearate, and stearic acid, polymethyl methacrylate fine particles, and polymer fine particles manufactured by soap-free emulsion polymerization such as polystyrene fine particles. . As the polymer fine particles, those having a relatively narrow particle size distribution are preferable, and those having a volume average particle size of 0.01 μm or more and 1 μm or less are preferable.

<< Compressible fluid >>
Next, a compressive fluid used in the manufacturing method of the present embodiment will be described with reference to FIGS. FIG. 2 is a phase diagram showing the state of a substance with respect to temperature and pressure. FIG. 3 is a phase diagram for defining the range of the compressible fluid. Compressible fluids have properties such as fast mass transfer and heat transfer, low viscosity, etc., and their density, dielectric constant, solubility parameter, free volume, etc. change continuously continuously by changing temperature and pressure. Have the property of Since the compressive fluid has extremely low interfacial tension as compared with the organic solvent, it can follow even a small undulation (surface) and can be wet with the compressive fluid. Also, by returning the compressive fluid to normal pressure, it is easy to separate it from the product such as toner, and it can be collected and reused. Thereby, in the manufacturing method of the present embodiment, the load on the environment during the manufacturing can be reduced as compared with the case where water, an organic solvent, or the like is used.

  The “compressible fluid” in the present embodiment means that the substance exists in any of the regions (1), (2), and (3) shown in FIG. 3 in the phase diagram shown in FIG. Means the state at the time. In such a region, it is known that the substance has a very high density and exhibits a behavior different from that at normal temperature and normal pressure. When the substance exists in the region (1), it becomes a supercritical fluid. The supercritical fluid is a fluid that exists as a non-condensable high-density fluid in a temperature / pressure region exceeding a limit (critical point) at which a gas and a liquid can coexist, and does not condense even when compressed. When the substance exists in the region (2), the substance becomes a liquid. In the present embodiment, the substance is obtained by compressing a substance that is in a gaseous state at normal temperature (25 ° C.) and normal pressure (1 atm). Liquefied gas. When the substance exists in the region (3), the substance is in a gaseous state. In the present embodiment, the substance is a high-pressure gas having a pressure equal to or more than １ ／ (１ ／ Pc) of the critical pressure (Pc).

  In the present embodiment, examples of the substance that can be used as the compressive fluid include, for example, carbon monoxide, carbon dioxide, nitrous oxide, nitrogen, air, oxygen, argon, helium, neon, krypton, methane, ethane, and propane. , 2,3-dimethylbutane, ethylene, ammonia, normal butane, isobutane, normal pentane, isobutane, chlorotrifluoromethane and the like. These compressive fluids may be used by mixing two or more kinds of substances.

  In the manufacturing method of the present embodiment, the first compressive fluid is not particularly limited as long as it can melt the pressure-plastic material, but can easily create a supercritical state, and is nonflammable and safe. When producing a toner, a toner having a hydrophobic surface can be obtained. Therefore, carbon dioxide is preferably used.

  In the manufacturing method of the present embodiment, as the second compressive fluid, a compressive fluid containing nitrogen, which is a substance having a maximum reversal temperature of 800 K or less, is preferably used. Here, containing nitrogen means containing nitrogen molecules, and it can be said that air also contains nitrogen. Nitrogen has a maximum reversal temperature of 620 K, which is lower than that of substances such as carbon dioxide (maximum reversal temperature of 1500 K). As a result, the decrease in temperature based on the Joule-Thomson effect when the pressure of nitrogen is reduced is smaller than when the pressure of carbon dioxide or the like is reduced. On the other hand, if the maximum reversal temperature of the second compressible fluid is too high, such as carbon dioxide, the cooling by the Joule-Thomson effect becomes excessive when the melt is injected, and the melt becomes particles. By solidifying beforehand, a fibrous or coalesced product may be mixed. If the cooling is excessive, the melt solidifies inside a nozzle or the like for injecting the melt, and it becomes impossible to produce small-sized particles having a narrow particle size distribution for a long time.

  In the present embodiment, the compressible fluid can be used together with an entrainer (cosolvent). Examples of the entrainer include alcohols such as methanol, ethanol and propanol, ketones such as acetone and methyl ethyl ketone, and organic solvents such as toluene, ethyl acetate and tetrahydrofuran.

  When the particles produced by the production method of the present embodiment are toners, other fluids can be used in addition to the compressive fluid. As the other fluid, a fluid that can easily control the solubility of the toner composition is preferable. Specific examples include methane, ethane, propane, butane, ethylene and the like.

<< Particle Production Equipment >>
Subsequently, a particle manufacturing apparatus used in the present embodiment will be described with reference to FIG. FIG. 4 is a schematic diagram illustrating an example of the particle manufacturing apparatus. The particle manufacturing apparatus 1 includes a cylinder 11, a pump 12a, a valve 13a, a high-pressure cell 14, a pump 12b, and a valve connected by ultra-high pressure pipes (30a, 30b, 30c, 30d, 30e, 30f) to form a first path. 13b. Further, the particle manufacturing apparatus 1 heats the inside of the ultrahigh-pressure pipe 30i with the cylinder 21, the pump 22, and the valve 23 connected by the ultrahigh-pressure pipes (30g, 30h, 30i) to form the second path. And the heater 26. Further, the particle manufacturing apparatus 1 includes a mixing device 31 whose ends are connected to respective ends of the first path pipe 30f and the second path pipe 30i, and a nozzle 32 that is connected to the other end of the mixing apparatus 31. And

  The cylinder 11 installed on the first path is a pressure-resistant container for storing and supplying the first compressible fluid. The cylinder 11 may store a gas (gas) or a solid that becomes a compressible fluid by being heated or pressurized in the process of being supplied to the high-pressure cell 14 or in the high-pressure cell 14. In this case, the gas or solid stored in the cylinder 11 is heated or pressurized, so as to be in the state (1), (2), or (3) in the phase diagram of FIG. . The pump 12a is a device that sends out the compressible fluid stored in the cylinder 11 toward the high-pressure cell 14 on the first path. The valve 13a is a device for opening and closing a path between the pump 12a and the high-pressure cell 14 to adjust or shut off the flow rate of the compressible fluid.

  The high-pressure cell 14 has a temperature controller, and brings a compressive fluid supplied through the valve 13a into contact with a pressure-plastic material previously filled in the high-pressure cell 14 at a predetermined temperature, thereby obtaining a pressure plasticity. This is a device for melting the material. The high pressure cell 14 is provided with a back pressure valve 14a, and the pressure in the high pressure cell 14 can be adjusted by opening and closing the back pressure valve 14a. Further, a stirrer is attached to the high-pressure cell 14, whereby the compressive fluid and the pressurized plastic material can be stirred and mixed.

  The pump 12b is a device that sends out the melt in the high-pressure cell 14 to the mixing device 31 side. The valve 13b is a device for opening and closing the path between the pump 12b and the mixing device 31 to adjust or shut off the flow rate of the melt obtained by melting the pressure plastic material. In the present embodiment, the particle manufacturing apparatus 1 does not directly inject the melt in the high-pressure cell 14 but injects it from the nozzle 32 after passing through the ultrahigh-pressure pipes (30d, 30e, 30f). As a result, the compressible fluid mixed in the high-pressure cell 14 is sufficiently diffused into the pressure-plastic material, so that the processability is improved.

  The cylinder 21 of the particle manufacturing apparatus 1 is a pressure-resistant container for storing and supplying a second compressible fluid containing nitrogen. The cylinder 21 may store a gas (gas) or a solid that is heated or pressurized to become a compressible fluid in the process of being supplied to the mixing device 31. In this case, the gas or solid stored in the cylinder 21 is heated or pressurized, so as to be in the state (1), (2), or (3) in the phase diagram of FIG. .

  The pump 22 is a device that sends out the second compressible fluid stored in the cylinder 21 to the mixing device 31 side. The valve 23 is a device for opening and closing the path between the pump 22 and the mixing device 31 to adjust or shut off the flow rate of the second compressible fluid.

  The heater 26 is a device for heating the compressible fluid passing through the ultrahigh-pressure pipe 30i. Since the compressible fluid heated by the heater 26 is cooled at the outlet of the heater 26 by the Joule-Thomson effect, it is sufficiently heated and the supercritical fluid (1) in the phase diagram of FIG. Is preferable.

  The mixing device 31 of the particle manufacturing device 1 is a device that mixes the melt supplied from the first path and the second compressive fluid supplied from the second path. The other end of the mixing device 31 is connected to the nozzle 32. In the present embodiment, the mixing device 31 has a mechanism of turbulent mixing in order to uniformly mix the compressible fluid and the pressure plastic material. Specific examples of the mixing device 31 include a well-known T-shaped joint, a swirl mixer that actively uses a swirl flow, and a center collision type mixer in which two liquids collide in a mixing section.

  Note that, for example, when a fluid having different viscosities such as a molten resin and a compressible fluid is mixed using a static mixer as described in Patent Document 3, it is difficult to uniformly mix both fluids. There are many cases. The static mixer has a mixing element (element) in a tubular housing. This element does not have a movable part, and a plurality of baffle plates are arranged along the axial direction about the tube axis. In the case of using the static mixer, the fluid is subjected to a dividing, inverting, and inverting action by an element provided in the pipe while being moved in the tubular housing, and is mixed. Further, as another type of static mixer, there is known a mixer in which a large number of elements formed of honeycomb-shaped plates constituted by polygonal small chambers are superposed. In such a static mixer, the fluid is subjected to dispersion, inversion, and vortex action by sequentially moving the small chamber inside the tube from the center to the outside of the tube and from the outside to the center to be mixed.

  However, when a high-viscosity fluid such as resin and a low-viscosity fluid such as a compressible fluid are passed through these static mixers, the low-viscosity fluid is not subjected to the mixing action by the elements, and the in-pipe element and the Through the gaps, and cannot be mixed homogeneously. As a countermeasure against poor mixing, methods such as complicating the element structure and increasing the length of the mixer can be considered.However, these countermeasures are not effective measures for preventing the low-viscosity fluid from passing through. Problems such as an increase in pressure loss, an increase in the size of the apparatus, and an increase in cleaning labor are caused.

  The nozzle 32 is a device that injects the melt. The nozzle 32 is connected to the mixing device 31 at one end. This allows the melt to be injected into the atmosphere by the pressure difference from the nozzle 32 while supplying the second compressive fluid. In this case, by supplying the second compressive fluid to the melt, the pressure loss in the nozzle 32 can be prevented, so that a decrease in temperature based on the Joule-Thomson effect is suppressed and workability is improved. This makes it possible to produce particles even when the amount of the wax component added to the raw material is small and the molecular weight of the pressure plastic material is high.

  The type of the nozzle 32 is not particularly limited, but a direct nozzle is preferably used. The diameter of the nozzle 32 is not particularly limited as long as the pressure at the time of injection can be kept constant. However, if the pressure is too large, the pressure at the time of injection is too low to increase the viscosity of the melt, making it difficult to obtain fine particles. There is. Further, in order to maintain the pressure in the nozzle 32, the pump 22 or the like may need to be upsized. On the other hand, if the nozzle diameter is too small, the melt tends to be clogged with the nozzle 32, and it may be difficult to obtain the target fine particles. Therefore, the nozzle diameter has no upper limit, and the lower limit is preferably 5 μm or more, more preferably 20 μm or more, and particularly preferably 50 μm or more.

<<< Each process of particle production >>>
Next, each step of manufacturing a toner as an example of particles using the particle manufacturing apparatus 1 of FIG. 4 will be described. The method for producing particles according to the present embodiment includes a melting step in which the first compressive fluid is brought into contact with the pressurized plastic material to melt the pressurized plastic material, and a process in which nitrogen is added to the melt obtained by melting the pressurized plastic material. And granulating by injecting a melt while supplying a second compressive fluid containing

<Melting process>
First, the melting step in the method for producing particles of the present embodiment will be described. As described above, in the present embodiment, “molten” means a state in which a raw material such as a pressure plastic material is swollen and plasticized and liquefied by contact with a compressive fluid. Conventionally, a method of depositing a substance in a supercritical fluid through a decompression step is known as a rapid expansion method. Among the rapid expansion methods, the discharge target used in the method known as the RESS (Rapid Expansion of Supercritical Solutions) method is a material in which a solute is dissolved in a compressible fluid, and the material that becomes a solute in the compressible fluid. Are homogeneously compatible with each other. On the other hand, in the present embodiment, the PGSS method (Particles from Gas Saturated Solutions) of the rapid expansion method is used. As described above, the melt to be discharged in the PGSS method is obtained by lowering the viscosity of the pressurized plastic material by contacting and wetting the pressurized fluid into the pressurized plastic material. An interface exists between the body and the body. In other words, the discharge target in the RESS method is a phase in a compressible fluid-solid equilibrium state, whereas in the PGSS method, it is a phase in a gas-liquid equilibrium state. The phase state of the subject before expansion is different.

  In the melting step, first, the high-pressure cell 14 is filled with raw materials such as a pressure plastic material and a colorant. In this case, when the raw material contains a plurality of components, these components may be mixed in advance by a mixer or the like and then melt-kneaded by a roll mill or the like before filling the raw material. Next, the high-pressure cell 14 is closed, and the raw materials are stirred by the stirring device of the high-pressure cell 14. Subsequently, the first compressive fluid stored in the cylinder 11 is pressurized by operating the pump 12a, and the first compressive fluid is supplied into the high-pressure cell 14 by opening the valve 13a. In the present embodiment, a carbon dioxide gas (carbon dioxide) cylinder is used as the cylinder 11. The temperature in the high-pressure cell 14 is adjusted by a temperature controller to a temperature at which the supplied carbon dioxide becomes a compressive fluid. The upper limit of the temperature in the high-pressure cell 14 is not particularly limited and may be appropriately selected depending on the intended purpose. However, the upper limit is preferably equal to or lower than the thermal decomposition temperature of the pressure-sensitive plastic material at atmospheric pressure. The following is more preferred. In the present embodiment, the thermal decomposition temperature means the temperature at which the weight of the sample starts to decrease due to thermal decomposition in the measurement of a thermal analysis device (TGA: Thermo Gravimetry Analyzer). When the temperature in the high-pressure cell 14 exceeds the thermal decomposition temperature, the pressure plastic material is oxidized, or the molecular chains are cut to be deteriorated to deteriorate the durability, and the color tone and transparency of the toner as a product are reduced. Properties, fixing characteristics, heat-resistant storage stability, and charging performance are reduced. Further, energy consumption by the heat treatment increases.

  The pressure in the high-pressure cell 14 is adjusted to a predetermined pressure by adjusting the pump 12a and the back pressure valve 14a. In the melting step of the method for producing particles of the present embodiment, the pressure applied to the raw material such as the pressure plastic material in the high-pressure cell 14 is not particularly limited and may be appropriately selected depending on the purpose. It is preferably at least 10 MPa and at most 200 MPa, particularly preferably at least 31 MPa and at most 100 MPa. If the pressure in the high-pressure cell 14 is smaller than 1 MPa, a plasticizing effect sufficient to granulate the pressure plastic material may not be obtained. There is no problem if the pressure in the high-pressure cell 14 is high, but the higher the pressure, the heavier the device and the higher the equipment cost.

  In the high-pressure cell 14, the compressible fluid and the raw material including the pressure-plastic material come into contact with each other, so that the pressure-plastic material melts. In this case, the melt is stirred by the stirrer until the viscosity of the melt obtained by melting the pressure plastic material becomes constant. The viscosity of the melt is not particularly limited as long as it can be ejected by the nozzle 32, but the lower the viscosity, the more it is possible to inject even if the nozzle diameter is reduced, and it is easy to atomize. For this reason, the viscosity of the melt is preferably 500 mPa · s or less, more preferably 300 mPa · s or less, even more preferably 100 mPa · s or less, in order to obtain a toner that realizes high image quality. Is preferably 20 mPa · s or less. If the viscosity of the melt is greater than 500 mPa · s, it may be difficult to form particles, or coarse particles, fibrous materials, foaming, coalescence, etc. may occur. In this embodiment, since the pressure plastic material is used, the pressure of the compressible fluid promotes the reduction of the viscosity of the pressure plastic material. A melt of viscosity is obtained.

<Granulation process>
Subsequently, the granulating step in the method for producing particles of the present embodiment will be described. First, the pump 22 is operated and the valve 23 is opened to supply the second compressive fluid stored in the cylinder 21 to the mixing device 31. In this embodiment, a nitrogen cylinder is used as the cylinder 21. The pressure of the second compressive fluid to be supplied is not particularly limited and may be appropriately selected depending on the purpose. However, the pressure is preferably 1 MPa or more, more preferably 10 MPa or more and 200 MPa or less, and particularly preferably 31 MPa or more and 100 MPa or less. preferable. If the pressure applied to the second compressive fluid is smaller than 1 MPa, a plasticizing effect sufficient to granulate the pressure plastic material may not be obtained. There is no problem no matter how high the pressure is, but the higher the pressure, the heavier the equipment and the higher the equipment cost. The supplied second compressive fluid is heated by the heater 26 in the ultrahigh-pressure pipe 30i. The set temperature of the heater 26 is not particularly limited as long as the supplied nitrogen becomes a compressive fluid.

  Next, the melt of the pressure plastic material in the high pressure cell 14 is supplied to the mixing device 31 by operating the pump 12b and opening the valve 13b. At this time, the pump 12a, the back pressure valve 14a, the temperature controller and the like are controlled so that the temperature and the pressure in the high-pressure cell 14 are kept constant. In this case, the pressure in the high-pressure cell 14 is not particularly limited, but may be equal to the pressure of the compressible fluid supplied from the second path. The melt supplied from the high-pressure cell 14 and the second compressive fluid supplied from the cylinder 21 are uniformly mixed by the mixing device 31. Thereby, while supplying the second compressive fluid to the melt, the melt can be jetted from the nozzle 32 under atmospheric pressure by a pressure difference.

  In this case, since the solid content concentration of the melt injected by the supply of the second compressive fluid decreases, the viscosity of the melt can be further reduced. As a result, not only the temperature of the melt to be sprayed is controlled to be constant, but also the spray speed (linear velocity at the outlet) increases, and the shearing force on the melt due to the improvement of the linear velocity at the outlet increases. In addition, by using nitrogen as the second compressive fluid, a decrease in temperature due to the Joule-Thomson effect due to a pressure change in the vicinity of the nozzle 32 is reduced, so that the nozzle 32 is less likely to be clogged. The melt injected from the nozzle 32 is solidified after being turned into particles. In this case, due to the synergistic effect of lowering the viscosity of the melt and lowering the solid content, uniform fine particles without coalescence can be obtained over a long period of time. Further, the effect of uniformly stabilizing the shape of the produced particles can be obtained.

<<<< Particle >>>>
In the present embodiment, an example in which the toner is manufactured has been described. However, the particles to be manufactured are not limited thereto, and may be appropriately selected according to the purpose. For example, particles of daily necessities, pharmaceuticals, cosmetics, and the like may be used. The shape, size, material, and the like of the particles produced by the production method of the present embodiment are appropriately selected depending on the purpose of the product and the like, and are not particularly limited. According to the production method of the present embodiment, by using a compressive fluid, it is possible to produce particles without using an organic solvent. As a result, particles substantially containing no organic solvent are obtained. In addition, that a particle does not contain an organic solvent substantially means that the content of the organic solvent in the particle measured by the following measurement methods is below the detection limit.

(Method of measuring residual solvent)
The residual solvent amount of the particles is measured by the following measuring method. After adding 2 parts by mass of 2-propanol to 1 part by mass of the particles to be measured and dispersing them by ultrasonic waves for 30 minutes, the mixture is stored in a refrigerator (5 ° C.) for at least one day to extract the solvent in the particles. The supernatant is analyzed by gas chromatography (GC-14A, SHIMADZU), and the solvent concentration in the particles is determined by quantifying the solvent and residual monomers. The measurement conditions at the time of such analysis are as follows.
Equipment: Shimadzu GC-14A
Column: CBP20-M 50-0.25
Detector: FID
Injection volume: 1-5 μl
Carrier gas: He 2.5 kg / cm2
Hydrogen flow rate: 0.6 kg / cm2
Air flow rate: 0.5 kg / cm2
Chart speed: 5mm / min
Sensitivity: Range101 × Atten20
Column temperature: 40 ° C
Injection Temp ： 150 ℃

<<< toner >>>
The toner produced by the production method of the present embodiment has, for example, an image density, an average circularity, a mass average particle diameter, and a mass average particle diameter as described below, although there are no particular restrictions on the characteristics such as its shape and size. It is preferable to have a ratio (mass average particle diameter / number average particle diameter) of the number and the number average particle diameter.

  As for the image density of the toner, a density value measured using a spectrometer (manufactured by X-Rite, 938 spectrodensitometer) is preferably 1.90 or more, more preferably 2.00 or more, and more preferably 2.10 or more. Particularly preferred. If the image density is less than 1.90, the image density is low, and high image quality may not be obtained. Here, the image density is determined, for example, using image Neo 450 (manufactured by Ricoh Co., Ltd.) and the amount of the developer attached to the copy paper (TYPE6000 <70W>, manufactured by Ricoh Co., Ltd.) is 1.00 ± 0.05 mg / forming a solid image of cm 2 at a surface temperature of the fixing roller of 160 ± 2 ° C., measuring image densities at arbitrary six points in the obtained solid image using the above spectrometer, and calculating an average value thereof. Can be measured.

  The average circularity of the toner is a value obtained by dividing the perimeter of an equivalent circle having the same projected area as the shape of the toner by the perimeter of the actual particles, for example, preferably 0.900 or more and 0.980 or less, and 0.950 or more. 0.975 or less is more preferable. Further, particles having an average circularity of less than 0.94 are preferably 15% by mass or less. If the average circularity is less than 0.900, satisfactory transferability and high quality images without dust may not be obtained. On the other hand, when the average circularity exceeds 0.980, in an image forming system employing blade cleaning or the like, cleaning failure occurs on the photoreceptor and the transfer belt, and stains on the image, such as a photographic image In the case of forming an image having a high image area ratio, the toner that has formed an untransferred image due to a paper feed failure or the like may become untransferred toner on the photoreceptor and cause the background of the accumulated image to occur. Alternatively, the charging roller or the like that contacts and charges the photoconductor may be contaminated, and the original charging ability may not be exhibited.

Here, the average circularity can be measured using a flow type particle image analyzer (Flow Particle Image Analyzer), for example, a flow type particle image analyzer FPIA-2000 manufactured by Toa Medical Electronics Co., Ltd. In this case, fine dust is removed by passing through a filter, and as a result, the number of particles in a measurement range (for example, a circle equivalent diameter of 0.60 μm or more and less than 159.21 μm) is adjusted to 20 or less in 10 ⁻³ cm ³ of water. Prepare the water. Next, several drops of a nonionic surfactant (preferably Contaminone N manufactured by Wako Pure Chemical Industries, Ltd.) are added to 10 ml of water containing the particles, and 5 mg of a measurement sample is further added. , UH-50) at 20 kHz and 50 W / 10 cm 3 for 1 minute, and further for a total of 5 minutes. The sample dispersion particle concentration of the measurement sample obtained by distributed processing 4,000 ^{/ 10} -3 cm ³ or more 8,000 ^{/ 10} -3 cm ³ or less (as the target particles measuring circle equivalent diameter range) The particle size distribution of particles having an equivalent circle diameter of 0.60 μm or more and less than 159.21 μm is measured.

  The measurement of the average circularity is performed by passing the sample dispersion liquid through a flow path (spread along the flow direction) of a flat and flat transparent flow cell (thickness: about 200 μm). Here, a strobe and a CCD camera are mounted so as to be located on opposite sides of the flow cell so as to form an optical path that passes through the flow cell in a direction intersecting the thickness of the flow cell. While the sample dispersion is flowing, strobe light is applied at 1/30 second intervals to obtain an image of the particles flowing through the flow cell. As a result, each particle is captured as a two-dimensional image having a fixed range parallel to the flow cell. From the area of the two-dimensional image of each particle, the diameter of a circle having the same area is calculated as the equivalent circle diameter.

  Thus, in about 1 minute, the equivalent circle diameter of 1,200 or more particles is measured, and the number based on the equivalent circle diameter distribution and the ratio (number%) of the particles having the specified equivalent circle diameter are calculated. The results (frequency% and cumulative%) can be obtained by dividing the range from 0.06 μm to 400 μm into 226 channels (divided into 30 channels per octave). In actual measurement, particles are measured in a range where the equivalent circle diameter is 0.60 μm or more and less than 159.21 μm.

  The mass average particle diameter of the toner is not particularly limited and may be appropriately selected depending on the intended purpose; however, it is preferably 3 μm or more and 10 μm or less, more preferably 3 μm or more and 8 μm or less. If the mass average particle diameter is less than 3 μm, in a two-component developer, the toner may fuse to the surface of the carrier during long-term stirring in a developing device, and may reduce the charging ability of the carrier. With the agent, filming of the toner on the developing roller and thinning of the toner may easily cause toner fusion to members such as a blade. When the mass average particle diameter exceeds 10 μm, it is difficult to obtain a high-resolution and high-quality image, and when the balance of the toner in the developer is performed, the fluctuation of the particle diameter of the toner increases. There is.

  The ratio of the mass average particle diameter to the number average particle diameter (mass average particle diameter / number average particle diameter) in the toner is preferably from 1.00 to 1.25, more preferably from 1.00 to 1.10. . When the ratio of the mass average particle diameter to the number average particle diameter (mass average particle diameter / number average particle diameter) exceeds 1.25, in the case of the two-component developer, the toner is formed on the surface of the carrier during long-term stirring in the developing device. May fuse to lower the charging ability of the carrier. Further, when the ratio of the mass average particle diameter to the number average particle diameter (mass average particle diameter / number average particle diameter) exceeds 1.25, in the one-component developer, filming of the toner onto the developing roller, In some cases, the toner becomes thinner, and the fusion of the toner to members such as a blade is likely to occur.Furthermore, it becomes difficult to obtain a high-resolution and high-quality image. In such a case, the variation in the particle size of the toner may increase.

  The mass average particle diameter and the ratio of the mass average particle diameter to the number average particle diameter (mass average particle diameter / number average particle diameter) are measured using, for example, a particle size analyzer “Coulter Counter TAII” manufactured by Coulter Electronics Co., Ltd. Can be measured.

<< Developer >>
Next, the developer according to the exemplary embodiment will be described. The developer according to the exemplary embodiment is not particularly limited as long as it has the toner manufactured by the above manufacturing method, and is appropriately selected depending on the purpose. Specific examples of the developer include a one-component developer having the toner manufactured by the above-described manufacturing method and a two-component developer having the toner manufactured by the above-described manufacturing method and a magnetic carrier. May be. Examples of the toner include color toners such as yellow, cyan, magenta, and black, and clear toners.

(Magnetic carrier)
The magnetic carrier is not particularly limited as long as it contains a magnetic material, and is appropriately selected according to the purpose. Specific examples of the magnetic carrier include hematite, iron powder, magnetite, and ferrite. The content of the magnetic carrier is preferably from 5% by mass to 50% by mass, more preferably from 10% by mass to 30% by mass, based on 100 parts by mass of the toner.

<< Image Forming Apparatus >>
Subsequently, the image forming apparatus according to the present embodiment will be described with reference to FIG. FIG. 5 is a schematic diagram illustrating an image forming apparatus according to an embodiment of the present invention. The image forming apparatus 200 develops the electrostatic latent image into a visible image using the toner manufactured by the above manufacturing method, transfers the visible image to a sheet as an example of a recording medium, and fixes the image. Form an image. In the present embodiment, an example in which the image forming apparatus 200 is an electrophotographic printer will be described. However, the present invention is not limited to this, and may be a copying machine, a facsimile, or the like.

  As shown in FIG. 5, the image forming apparatus 200 includes a paper feed unit 210, a transport unit 220, an image forming unit 230, a transfer unit 240, and a fixing unit 250.

  As shown in FIG. 5, the paper supply unit 210 includes a paper supply cassette 211 on which paper to be supplied is loaded, and a paper supply roller 212 for supplying paper loaded on the paper supply cassette 211 one by one. It has.

  The transport unit 220 sandwiches a roller 221 that transports the paper fed by the paper feed roller 212 in the direction of the transfer unit 240 and a leading end of the paper transported by the roller 221 and waits for the paper at a predetermined timing. The image forming apparatus includes a pair of timing rollers 222 that send out the toner to the transfer unit 240 and a paper discharge roller 223 that discharges the paper on which the toner is fixed by the fixing unit 250 to a paper discharge tray 224.

  The image forming unit 230 includes, at predetermined intervals, an image forming unit Y that forms an image using a developer having yellow toner (toner Y) in order from the left to the right in FIG. An image forming unit C using a developer having a cyan toner (toner C), an image forming unit M using a developer having a magenta toner (toner M), and a black toner (toner K). An image forming unit K using the developed developer and an exposing device 233 are provided. Each of the above toners (Y, C, M, K) is a toner obtained by the above manufacturing method.

  In FIG. 5, the four image forming units have substantially the same mechanical configuration except for the developer used for each. Each image forming unit is provided rotatably clockwise in FIG. 5, and carries a photosensitive drum (231Y, 231C, 231M, 231K) carrying an electrostatic latent image and a toner image, and photosensitive drums (231Y, 231C, 231M). , 231K) and the toner cartridges (237Y, 237C, 237M, 232K) for supplying the toners (Y, C, M, K) of the respective colors. 237K) and the electrostatic latent image formed on the surface of the photosensitive drum (231Y, 231C, 231M, 231K) by the exposure device 233 using the toner supplied from the toner cartridge (237Y, 237C, 237M, 237K). Each developing device (234Y, 234C, 234M, 234K) for developing an image and toner on the transfer medium (235Y, 235C, 235M, 235K) for neutralizing the surface of the photosensitive drums (231Y, 231C, 231M, 231K) after the primary transfer, and neutralization by the neutralizers (235Y, 235C, 235M, 235K). Cleaning devices (236Y, 236C, 236M, 236K) for removing transfer residual toner remaining on the surfaces of the respective photosensitive drums (231Y, 231C, 231M, 231K).

  The exposure device 233 reflects the laser beam L emitted from the light source 233a based on the image information by a polygon mirror (233bY, 233bC, 233bM, 233bK) rotated by a motor and exposes the photosensitive drum (231Y, 231C, 231M). , 231K). Thus, an electrostatic latent image based on the image information is formed on the photosensitive drum 231.

  The transfer unit 240 includes a driving roller 241 and a driven roller 242, an intermediate transfer belt 243 as a transfer medium that is wound around these rollers, and is rotatable counterclockwise in FIG. Primary transfer rollers (244Y, 244C, 244M, 244K) provided opposite to the photosensitive drum 231 with the belt 243 interposed therebetween, and secondary opposed rollers with the intermediate transfer belt 243 interposed at the transfer position of the toner image onto the paper 245, and a secondary transfer roller 246 provided opposite to the secondary transfer roller 245.

  In the transfer unit 240, the primary transfer roller 244 is applied with a primary transfer bias, so that each toner image formed on the surface of the photosensitive drum 231 is transferred (primary transfer) onto the intermediate transfer belt 243. Further, by applying a secondary transfer bias to the secondary transfer roller 246, the toner image on the intermediate transfer belt 243 is transferred to the paper being transported between the secondary transfer roller 246 and the secondary opposing roller 245. (Secondary transfer).

  The fixing unit 250 includes a heating roller 251 for heating the paper to a temperature higher than the minimum fixing temperature of the toner, and a contact surface (nip portion) which is rotatably pressed against the heating roller 251 and pressurized. ) Is formed. In the exemplary embodiment, the fixing lower limit temperature means a lower limit temperature at which the toner is fixed.

  In the image forming apparatus according to the present embodiment, the toner manufactured by the manufacturing method according to the present embodiment has a sharp particle size distribution, and has good toner characteristics such as chargeability, environmental properties, and stability over time. High quality images can be formed.

[Second embodiment]
Subsequently, a second embodiment of the present invention will be described. In the following description, points different from the first embodiment will be described, and description of points common to the first embodiment will be omitted.
<< Particle Production Equipment >>
First, the particle manufacturing apparatus used in the present embodiment will be described with reference to FIG. FIG. 6 is a schematic diagram illustrating an example of the particle manufacturing apparatus. 6, means, mechanisms, devices, and the like that are common to the particle manufacturing apparatus 1 of FIG. 4 are denoted by the same reference numerals.

  The particle manufacturing apparatus 2 includes a cylinder 11, a pump 12a, a valve 13a, a cell 24, and a pump connected as shown in FIG. 6 by ultrahigh pressure pipes (30a, 30b, 30c, 30d, 30e, 30f, 30j, 30k). The particle manufacturing apparatus 1 according to the first embodiment is different from the particle manufacturing apparatus 1 according to the first embodiment in having a valve 12b, a valve 13b, a valve 13c, a mixing device 17, and a heater 16.

  The cylinder 11 is a pressure-resistant container for storing and supplying the first compressive fluid. The cylinder 11 may store a gas (gas) or a solid that becomes a compressible fluid by being heated or pressurized in the process of being supplied to the cell 24 or in the cell 24. In this case, the gas or solid stored in the cylinder 11 is heated or pressurized to be in the state (1), (2), or (3) in the phase diagram of FIG. The pump 12 a is a device that sends out the compressible fluid stored in the cylinder 11 in the direction of the mixing device 17. The valve 13a is a device for opening and closing the path between the pump 12a and the mixing device 17 to adjust or shut off the flow rate of the compressible fluid. The heater 16 heats the compressible fluid passing through the ultrahigh-pressure pipe 30c.

  The cell 24 is a device that has a temperature controller and heats the pressurized plastic material by bringing the pressurized plastic material pre-filled in the cell 24 into contact at a predetermined temperature. The cell 24 is provided with a stirrer, which can stir the compressible fluid and the pressure plastic material to uniformly heat them.

  The pump 12b is a device that sends out the pressure plastic material in the cell 24 to the mixing device 17 side. The valve 13b is a device for opening and closing the path between the pump 12b and the mixing device 17 to adjust or shut off the flow rate of the melt obtained by melting the pressure plastic material.

  The mixing device 17 is a device that mixes the pressurized plastic material supplied from the high-pressure cell and the first compressive fluid supplied from the cylinder 11. Specific examples of the mixing device 17 include a well-known T-shaped joint, a swirl mixer that actively uses a swirl flow, and a center collision type mixer in which two liquids collide in a mixing section. The valve 13c is a device for opening and closing the path between the mixing device 17 and the mixing device 31 to adjust or shut off the flow rate of the melt.

<<< Each process of particle production >>>
Next, each step of manufacturing a toner as an example of particles using the particle manufacturing apparatus 2 of FIG. 6 will be described. In the method for producing particles according to the second embodiment, a pre-heated pressure plastic material is brought into contact with a first compressive fluid, and a second compressive fluid containing nitrogen is supplied to the obtained melt. Meanwhile, the melt is sprayed and granulated.

<Melting process>
First, the melting step in the method for producing particles of the present embodiment will be described. In the melting step, first, raw materials such as a pressure plastic material and a colorant are filled in the cells 24. In this case, when the raw material contains a plurality of components, these components may be mixed in advance by a mixer or the like and then melt-kneaded by a roll mill or the like before filling the raw material. Next, the cell 24 is closed, and the raw materials are stirred and heated by the stirring device of the cell 24. The temperature in the cell 24 at this time is not particularly limited as long as the pressure plastic material is plasticized. This plasticizes the pressure plastic material.

  Subsequently, the pump 12a is operated to pressurize carbon dioxide as the first compressive fluid stored in the cylinder 11, and the valve 13a is opened to supply the first compressive fluid to the mixing device 17. . In the present embodiment, a carbon dioxide gas (carbon dioxide) cylinder is used as the cylinder 11. The pressure applied to the compressible fluid by the pump 12a can be substantially equal to the pressure applied to the second compressible fluid by the pump 22. The supplied first compressive fluid is heated by the heater 16 in the ultrahigh-pressure pipe 30c. The set temperature of the heater 16 is not particularly limited as long as the supplied carbon dioxide becomes a compressive fluid.

  Subsequently, the pump 12b is operated to open the valve 13b. Thereby, the pressurized plastic material supplied from the cell 24 and the first compressive fluid supplied from the cylinder 11 are continuously contacted by the mixing device 17 and are uniformly mixed. This causes the pressure plastic material to melt. The viscosity of the melt obtained by melting the pressure-plastic material is not particularly limited as long as it can be injected by the nozzle 32, but the lower the viscosity, the easier it is to atomize at the time of injection. It is preferably at most s. If the viscosity of the melt is greater than 20 mPa · s, it may be difficult to form particles, or coarse particles, fibrous materials, foaming, coalescence, etc. may occur. Further, when the product is a toner, it may be difficult to produce the required uniform fine particles having a size of 4 to 8 μm.

<Granulation process>
Subsequently, the granulating step in the method for producing particles of the present embodiment will be described. First, the pump 22 is operated and the valve 23 is opened to supply the second compressive fluid stored in the cylinder 21 to the mixing device 31. In this embodiment, a nitrogen cylinder is used as the cylinder 21. The pressure of the supplied second compressive fluid is not particularly limited, and can be approximately the same as that in the first embodiment. The supplied second compressive fluid is heated by the heater 26 in the ultrahigh-pressure pipe 30i. The set temperature of the heater 26 is not particularly limited as long as the supplied nitrogen becomes a compressive fluid.

  Next, by opening the valve 13 c, the melt obtained by melting the pressurized plastic material in the mixing device 17 is supplied to the mixing device 31. Thereby, the melt supplied from the cell 24 and the second compressive fluid supplied from the cylinder 21 are uniformly mixed by the mixing device 31. The melt mixed by the mixing device 31 is continuously injected from the nozzle 32 under atmospheric pressure by a pressure difference. In this way, the melt can be ejected from the nozzle 32 while supplying the second compressive fluid. The melt injected from the nozzle 32 is solidified after being turned into particles. According to the method for producing particles of the second embodiment, particles can be produced without using a high-pressure cell, so that the effect of reducing the weight of the apparatus can be obtained.

<< Supplement to the embodiment >>
In each of the above embodiments, the case where the manufacturing apparatus used in the method for manufacturing particles is the particle manufacturing apparatus (1, 2) shown in FIG. 4 or FIG. 6 is not limited thereto. Instead of the particle manufacturing apparatus (1, 2), a general injection device used in the PGSS method may be used which is provided with each means of the second path, the mixing means 31, and the like.

  In the above embodiment, the case where the melt containing the pressure plastic material and the compressive fluid is injected into the atmosphere has been described, but the present invention is not limited to this. In this case, the melt can be injected into an environment where the pressure is higher than the atmosphere and lower than the pressure inside the nozzle 32. In this case, the controllability of the particle diameter and the particle diameter distribution can be improved by controlling the injection velocity (the exit linear velocity). Further, in this case, the cooling of the melt injected from the nozzle 32 by the Joule-Thomson effect can be reduced, so that the heating of the heater 26 can be suppressed, and effects such as energy saving and cost reduction can be obtained.

Next, the present invention will be described more specifically with reference to Examples and Comparative Examples, but the present invention is not limited to the following Examples. In the examples, all parts are parts by mass.

-Synthesis of polyester resin 1 (pressure plastic resin)-
In a reaction vessel equipped with a cooling pipe, a stirrer, and a nitrogen inlet pipe, 229 parts of bisphenol A ethylene oxide 2 mol adduct, 529 parts of bisphenol A propylene oxide 3 mol adduct, 208 parts of terephthalic acid, 46 parts of adipic acid and dibutyl Two parts of tin oxide were added and reacted at 230 ° C. and normal pressure for 8 hours. After the reaction was further performed at a reduced pressure of 10 to 15 mmHg at 5:00, 44 parts of trimellitic anhydride was added to the reaction vessel and reacted at 180 ° C. and normal pressure for 2 hours to obtain [polyester resin 1]. The obtained polyester resin 1 had a number average molecular weight of 2500, a weight average molecular weight of 6,700, a Tg of 43 ° C., an acid value of 25, and a gradient in a graph showing the relationship between pressure and glass transition temperature of −10 ° C./MPa. Note that a C-80 high-pressure calorimeter manufactured by SETARAM was used for measuring the glass transition temperature and the slope. In the measurement, a sample was set in a high-pressure measurement cell, and the inside of the cell was replaced with carbon dioxide, and then pressurized to a predetermined pressure. The rate of temperature rise was 0.5 ° C./min, and the temperature was raised to 200 ° C. to measure the glass transition temperature.

-Synthesis of polyester resin 2 (pressure plastic resin)-
25 mol of 1,4-butanediol, 23.75 mol of fumaric acid, 1.65 mol of trimellitic anhydride, 1.25 mol of hydroquinone were placed in a 5-liter four-necked flask equipped with a nitrogen inlet tube, a dehydrating tube, a stirrer and a thermocouple. Then, after reacting at 160 ° C. for 5 hours, the temperature was raised to 200 ° C. and reacted for 1 hour. The mixture was further reacted at 8.3 KPa for 1 hour to obtain [crystalline polyester resin 2]. The obtained [crystalline polyester resin 2] had a melting point of 119 ° C, Mn of 710, Mw of 2,100, an acid value of 24 and a hydroxyl value of 28. The gradient of the change of the glass transition temperature with respect to the pressure of the [polyester resin 3] measured by the same method as above was -5 ° C / MPa.

-Polylactic acid resin-
Toyobo's polylactic acid-based resin Viroecol (registered trademark) BE-400 was used. The gradient of the change in the glass transition temperature with respect to the pressure of the [polylactic acid resin] measured in the same manner as above was −20 ° C./MPa.

-Synthesis of polyester resin 3 (pressure plastic resin)-
343 parts of bisphenol A ethylene oxide 2 mol adduct, 166 parts of isophthalic acid and 2 parts of dibutyltin oxide are placed in a reaction vessel equipped with a cooling pipe, a stirrer and a nitrogen introduction pipe, and reacted at 230 ° C. for 8 hours under normal pressure. I let it. After further reacting at a reduced pressure of 10 to 15 mmHg for 5 hours, the mixture was cooled to 110 ° C., 17 parts of isophorone diisocyanate was added in toluene, reacted at 110 ° C. for 5 hours, and then desolvated to obtain [urethane-modified polyester resin 3 -1] was obtained. The obtained [urethane-modified polyester resin 3-1] had a weight average molecular weight of 72,000 and an isocyanate content of 0.7%.

  On the other hand, 570 parts of bisphenol A ethylene oxide 2 mol adduct and 217 parts of terephthalic acid were reacted at 230 ° C. for 6 hours under normal pressure to obtain unmodified [polyester resin 3-2]. The obtained [Polyester resin 3-2] had a number average molecular weight of 2,400, a hydroxyl value of 51, and an oxidation of 5. 200 parts of the obtained [urethane-modified polyester resin 3-1] and 800 parts of the [polyester resin 3-2] are dissolved and mixed in 2,000 parts of ethyl acetate to obtain a resin solution, and a part of the resin solution is dried under reduced pressure. Then, the resin component was isolated to obtain [polyester resin 3]. The gradient of the change in the glass transition temperature with respect to the pressure of the [polyester resin 3] measured in the same manner as above was −3 ° C./MPa.

-Example 1-
In Example 1, resin particles were manufactured using the particle manufacturing apparatus 1 of FIG. In Example 1, a carbon dioxide gas (carbon dioxide) cylinder was used as the cylinder 11. Further, a nitrogen cylinder was used as the cylinder 21.

  [Polyester resin 1] was charged into the high-pressure cell 14 of the particle manufacturing apparatus 1 shown in FIG. 4, carbon dioxide was introduced as the first compressive fluid at 160 ° C. and 2 MPa, and the mixture was stirred for 1 hour. . At this time, the viscosity of the obtained melt was 450 mPa · s. The viscosity of the melt was measured using a viscosity measuring device (VISCOlab PVT) manufactured by Cambridge Viscocity. In the measurement, a sample was set in the measuring section, the temperature and pressure were controlled, and the point at which the viscosity became constant was defined as the viscosity at that temperature and pressure. Next, the valve 23 was opened, the pump 22 and the heater 26 were operated, and supercritical nitrogen as a second compressive fluid was injected from the nozzle 32 so as to maintain 2 MPa and 160 ° C. In this state, the valve 13b was opened, the pump 12b was operated, and the melt was injected while supplying the second compressive fluid to the melt. At this time, by adjusting the pump 12a and the back pressure valve 14a, the inside of the high pressure cell 14 was maintained at a constant temperature of 160 ° C. and a pressure of 2 MPa. The sprayed melt was solidified after being granulated to obtain [Resin Particle 1]. The particles of [Resin Particle 1] obtained immediately after the start of the injection had a volume average particle diameter (Dv) of 65.3 μm, a number average particle diameter (Dn) of 8.9 μm, and Dv / Dn of 7.33. The particles of [Resin Particle 1] obtained later had a volume average particle diameter (Dv) of 68.5 μm, a number average particle diameter (Dn) of 8.8 μm, and Dv / Dn 7.78. The particle recovery ratio, which is the mass of the collected [resin particles 1] with respect to the mass of the input raw materials, was 80%. The volume average particle diameter and the ratio of the volume average particle diameter to the number average particle diameter (volume average particle diameter / number average particle diameter) were measured using a particle size analyzer “Coulter Counter TAII” manufactured by Coulter Electronics. It was measured.

-Examples 2 to 4
[Resin Particles 2 to 4] were obtained in the same manner as in Example 1, except that the processing temperature, the processing pressure, and the nozzle diameter were changed to the values shown in Table 1. Tables 1 and 2 show the viscosity, volume average particle diameter (Dv), number average particle diameter (Dn), Dv / Dn, and recovery rate of the melt measured in the same manner as in Example 1.

Example 5
Except that [Polyester Resin 1] is changed to [Polyester Resin 2] and the processing temperature, processing pressure, and nozzle diameter are changed to the values shown in Table 1, the same operation as in Example 1 is performed, and [Resin Particles 5]. I got Tables 1 and 2 show the viscosity, volume average particle diameter (Dv), number average particle diameter (Dn), Dv / Dn, and recovery rate of the melt measured in the same manner as in Example 1.

-Example 6-
In Example 6, a toner was manufactured using the particle manufacturing apparatus 2 of FIG. In Example 6, a carbon dioxide gas (carbon dioxide) cylinder was used as the cylinder 11. Further, a nitrogen cylinder was used as the cylinder 21.

(raw materials)
Polyester resin 1 95 parts Colorant (copper phthalocyanine blue) 5 parts Paraffin wax (melting point 79 ° C.) 5 parts The above-mentioned toner raw materials were mixed by a mixer, melt-kneaded by a two-roll mill, and the kneaded material was rolled and cooled. This kneaded material was put into the cell 24 of the particle manufacturing apparatus 2 shown in FIG. 6, and was heated to 150 ° C. to be plasticized. The pump 12a was operated, the valve 13a was opened, and carbon dioxide was introduced as the first compressive fluid at 150 ° C. and 40 MPa. Further, the pump 12b was operated, the valve 13b was opened, and the plasticized kneaded material and the first compressive fluid were continuously brought into contact with each other and mixed by the mixing device 17. Next, the valve 23 was opened, and using the pump 22 and the heater 26, supercritical nitrogen as a second compressive fluid was injected from the nozzle 32 so as to maintain 40 MPa and 150 ° C. In this state, the valve 13c was opened, and the melt was continuously injected from the nozzle 32 while supplying the second compressive fluid to the melt obtained by contacting the kneaded material with the first compressive fluid. . At this time, the melt passing through the mixing device 17 was maintained at a constant temperature of 150 ° C. and a constant pressure of 40 MPa by adjusting the pumps 12a and 12b. The jetted melt was solidified after being formed into particles, and [Toner 6] was obtained. Tables 1 and 2 show the viscosity, number average particle size (Dn), Dv / Dn, and recovery of the melt measured in the same manner as in Example 1.

-Example 7-
[Toner 7] was obtained in the same manner as in Example 6, except that the processing temperature and the processing pressure were changed to the values shown in Table 1. Tables 1 and 2 show the viscosity, volume average particle diameter (Dv), number average particle diameter (Dn), Dv / Dn, and recovery rate of the melt measured in the same manner as in Example 1.

-Example 8-
[Toner 8] was manufactured in the same manner as in Example 6, except that [Polyester resin 1] as the toner raw material was changed to [Polylactic acid resin], and the processing temperature and processing pressure were changed to the values shown in Table 1. Obtained. Tables 1 and 2 show the viscosity, volume average particle diameter (Dv), number average particle diameter (Dn), Dv / Dn, and recovery rate of the melt measured in the same manner as in Example 1.

-Example 9-
[Toner 9] was obtained in the same manner as in Example 7, except that the cylinder 21 was changed from a nitrogen cylinder to an air cylinder. Tables 1 and 2 show the melt viscosity, volume average particle diameter (Dv), number average particle diameter (Dn), Dv / Dn, and recovery rate of [Toner 9] measured in the same manner as in Example 1. .

-Comparative Example 1-
(Toner raw materials)
350 g of polyester resin
Coloring agent (copper phthalocyanine blue) 2.5 parts Trimethylolpropane tribeneneate (melting point 58 degrees) 12.5 parts Resin dissolution with a stirrer and temperature measuring device, which can be set up to a premises pressure of 30 MPa and a premises temperature of 290 ° C After raising the temperature of the bath 500 ml to 150 ° C., the above-mentioned toner raw materials were charged and melted. Next, a molten resin and 10 g of liquefied carbon dioxide were injected into a static mixer having an inner diameter of 5 mm and 30 elements using a pressurizing pump. At this time, the pressure in the static mixer was set to 8 MPa. An operation of injecting a mixture of carbon dioxide and resin under atmospheric pressure from a nozzle with a hole diameter of 50 μm attached to the tip of the static mixer was performed, but the plasticization of the toner melt was insufficient and granulation could not be performed. Was.

-Comparative Example 2-
The same operation as in Example 6 was carried out except that the processing pressure and the nozzle diameter were changed to the values shown in Table 1, but the plasticization of the toner melt was insufficient and granulation could not be performed.

-Comparative Example 3-
[Comparative Toner 3] was obtained in the same manner as in Example 7, except that the cylinder 21 was changed from a nitrogen cylinder to a carbon dioxide cylinder. Tables 1 and 2 show the melt viscosity, volume average particle diameter (Dv), number average particle diameter (Dn), Dv / Dn, and recovery rate of [Comparative Toner 3] measured in the same manner as in Example 1. Show.

  0.7 parts by mass of hydrophobic silica and 0.3 parts by mass of hydrophobic titanium oxide are added to 100 parts by mass of each of the toners [toner 6 to 9, comparative toner 3], and the mixture is added to the mixture using a Henschel mixer. Mixing was performed for 5 minutes at a peripheral speed of 8 m / s. The mixed powder was passed through a mesh having an opening of 100 μm to remove coarse powder. Next, 5% by mass of the toner subjected to the external additive treatment and 95% by mass of a copper-zinc ferrite carrier coated with a silicone resin and having an average particle diameter of 40 μm are tumbled and stirred by a container. The mixture was uniformly mixed and charged using a mixer to prepare a two-component system [Developers 6 to 9, Comparative Developer 3]. The toners used in [Developers 6 to 9 and Comparative developer 3] correspond to [Toners 6 to 9 and Comparative toner 3] in this order. Incidentally, for [Comparative Toner 1, 2], the two-component developer was not adjusted.

  Further, 0.7 parts by mass of hydrophobic silica and 0.3 parts by mass of hydrophobic titanium oxide were added to 100 parts by mass of each of [Toner 6 to 9, Comparative toner 3], and the peripheral speed was 8 m / s using a Henschel mixer. Was mixed for 5 minutes to prepare a one-component system [Developers 16 to 19, Comparative developer 13]. The toners used in [Developers 16 to 19 and Comparative developer 13] correspond to [Toners 6 to 9 and Comparative toner 3] in this order. Incidentally, for [Comparative Toner 1, 2], a one-component developer was not adjusted.

  For each of the obtained developers, an image forming apparatus (IPSio Color 8100 manufactured by Ricoh Co., Ltd. was used for evaluation of the two-component developer, and imageio Neo C200 manufactured by Ricoh Co., Ltd. was used for evaluation of the one-component developer). ), An image was output, and evaluated as follows. Table 3 shows the results.

<Image density>
After outputting a solid image with a low adhesion amount of 0.3 ± 0.1 mg / cm 2, which is a low adhesion amount on a plain paper transfer paper (manufactured by Ricoh Co., Ltd., type 6200), the image density was measured with a densitometer X-Rite And the following criteria.
〔Evaluation criteria〕
◎: image density of 1.4 or more．: 1.35 or more and less than 1.4 Δ: 1.3 or more and less than 1.35 ×: less than 1.3

<Toner scattering>
In an environment of a temperature of 40 ° C. and a humidity of 90% RH, an image forming apparatus (IPSiO Color 8100, manufactured by Ricoh Co., Ltd.) was modified to an oil-less fixing system, and an image machine was used. % Chart The toner contamination state in the copying machine after the 100,000 sheet continuous output durability test was performed was visually evaluated according to the following criteria.
〔Evaluation criteria〕
A: Good condition without any toner stain observed.
：: Slight stain observed, no problem.
Δ: Slight stain is observed.
×: Very dirty outside the allowable range, which is a problem.

<Transferability>
After transferring the image area ratio chart of 20% from the photoconductor to the paper, the transfer residual toner on the photoconductor immediately before cleaning is transferred to white paper with Scotch tape (manufactured by Sumitomo 3M Limited), and the transferred toner is transferred to a Macbeth reflection densitometer RD514. It was measured and evaluated according to the following criteria.
〔Evaluation criteria〕
A: Difference from blank is less than 0.005.
：: The difference from the blank is 0.005 to 0.010.
Δ: The difference from the blank is 0.011 to 0.02.
X: The difference from the blank exceeds 0.02.

<Charging stability>
Using each of the toners and a character image pattern having an image area ratio of 12%, a continuous 100,000-sheet output durability test was performed, and the change in the charge amount at that time was evaluated. A small amount of the developer was sampled from the sleeve, and the change in charge amount was determined by a blow-off method.
〔Evaluation criteria〕
：: Change in charge amount is less than 5 μc / g.
Δ: Change in charge amount is 5 μc / g or more and 10 μc / g or less.
X: The change in the charge amount exceeds 10 μc / g.

<Filming property>
After 1000 sheets of band charts with image area ratios of 100%, 75%, and 50% were output, filming on the developing roller and the photosensitive member was observed, and evaluated based on the following criteria.
〔Evaluation criteria〕
◎: Filming did not occur at all.
：: Filming can be slightly observed.
B: Filming occurs in a streak shape.
×: Filming has occurred on the entire surface.

<Cleaning properties>
The transfer residual toner on the photoreceptor that has passed the cleaning process after outputting 1000 sheets of the image area ratio 95% chart is transferred to a blank sheet of paper using Scotch tape (manufactured by Sumitomo 3M Limited) and measured with a Macbeth reflection densitometer RD514. Was evaluated according to the following criteria.
〔Evaluation criteria〕
A: Difference from blank is less than 0.005.
：: The difference from the blank is 0.005 to 0.010.
Δ: The difference from the blank is 0.011 to 0.02.
X: The difference from the blank exceeds 0.02.

<Comprehensive evaluation>
Of the evaluation results of each evaluation item, ◎ was 1 point, ○ was 0 point, Δ was −1 point, and × was −2 points, and comprehensive evaluation was performed based on the total points.
◎: 4 to 5 total points ○: 0 to 3 total points △: -3 to -1 total points ×: -4 or less total points

DESCRIPTION OF SYMBOLS 1 Particle manufacturing apparatus 2 Particle manufacturing apparatus 11, 22 Cylinders 12a, 12b, 22 Pumps 13a, 13b, 23 Valve 14 High-pressure cell 16, 26 Heater 24 Cell 17, 31 Mixing device 32 Nozzle 200 Image forming device 210 Feeding unit 211 Supply Paper cassette 212 Paper feed roller 220 Transport unit 221 Roller 222 Timing roller 223 Discharge roller 224 Discharge tray 230 Image forming unit 231 Photosensitive drum (an example of an electrostatic latent image carrier)
232 Charger 233 Exposure unit (an example of an electrostatic latent image forming unit)
234 Developing device (an example of developing means)
235 Static eliminator 236 Cleaner 237 Toner cartridge 240 Transfer unit (an example of a transfer unit)
241 drive roller 242 driven roller 243 intermediate transfer belt 244 primary transfer roller 245 secondary opposing roller 246 secondary transfer roller 250 fixing unit (an example of a fixing unit)
251 Heating roller 252 Pressure roller T Toner

Japanese Patent No. 2677785 JP-A-10-20552 Japanese Patent No. 41113452

The invention according to claim 1 includes a melting step of bringing the first compressive fluid into contact with the pressurized plastic material to melt the pressurized plastic material, and adding a nitrogen to the melt obtained by melting the pressurized plastic material. a supply step of supplying a second compressed fluid comprising a granulation step of granulating by vacuum the melt by injecting supplied the melt said second compressive fluid, the The first compressible fluid and the second compressible fluid independently compress a supercritical fluid, a substance that is in a gaseous state at normal temperature (25 ° C.) and normal pressure (1 atm). A liquefied gas obtained as described above or a high-pressure gas whose pressure is equal to or more than 臨界 (１ ／ Pc) of the critical pressure (Pc) .

Claims (14)

A melting step of contacting the first compressive fluid with the pressurized plastic material to melt the pressurized plastic material;
A granulating step of granulating by spraying the melt while supplying a second compressive fluid containing nitrogen to the melt obtained by melting the pressure plastic material,
A method for producing particles, comprising:   The method according to claim 1, wherein, in the melting step, the pressurized plastic material heated and plasticized in advance is brought into contact with the first compressive fluid.   The method according to claim 1, wherein the melt has a viscosity of 500 mPa · s or less.   The method for producing particles according to claim 3, wherein the viscosity of the melt is 20 mPa · s or less.   The particle according to any one of claims 1 to 4, wherein a gradient of a change in a glass transition temperature of the plastic material with respect to a pressure applied to the plastic material is −5 ° C./MPa or less. Manufacturing method.   The method for producing particles according to claim 5, wherein a gradient of a change in the glass transition temperature of the plastic material with respect to the pressure applied to the plastic material is -10C / MPa or less.   The method according to any one of claims 1 to 6, wherein in the melting step, the first compressive fluid and the pressure plastic material are brought into continuous contact without using a static mixer. Method for producing particles. In the melting step, the first compressive fluid and the pressurized plastic material are continuously brought into contact with each other, and in the granulation step, the melt is sprayed to continuously granulate. The method for producing particles according to any one of claims 1 to 7.   The method according to any one of claims 1 to 8, wherein the pressure plastic material is a polyester resin.   The method for producing particles according to any one of claims 1 to 9, wherein the first compressive fluid contains carbon dioxide.   The method according to any one of claims 1 to 10, wherein the pressure plastic material is a raw material of a toner.   A toner produced by the method for producing particles according to claim 11, wherein the toner substantially does not contain an organic solvent.   A developer comprising the toner according to claim 12. An electrostatic latent image carrier,
Electrostatic latent image forming means for forming an electrostatic latent image on the electrostatic latent image carrier,
Developing means for developing the electrostatic latent image formed by the electrostatic latent image forming means into a visible image using the toner according to claim 12;
Transfer means for transferring the visible image developed by the developing means to a recording medium,
Fixing means for fixing the transfer image transferred by the transfer means to the recording medium,
An image forming apparatus comprising: