JP2013216847A - Method for producing particle, particle, toner, developing agent and image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a production method of a toner using liquefied carbon dioxide, without using an organic solvent.SOLUTION: A production method of a particle comprises the steps of: bringing a compressible fluid such as liquefied carbon dioxide into contact with a pressure plastic material; promoting plasticization of the pressure plastic material by pressure of the compressive fluid; mixing the compressive fluid and the pressure plastic material more uniformly; melting the pressure plastic material so that viscosity of obtained melt is lowered to 500 mPa s or less to be easily granulated; and granulating the melt by spraying.

Description

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

  Conventionally, various particulate products have been manufactured by processing a resin based on its physical properties. For example, a method of manufacturing a toner as an example of particles by melting and kneading a composition comprising a resin and an additive, cooling, solidifying, pulverizing, and classifying is known (see Patent Document 1). However, when the toner is produced by this method, there is a problem that the fine powder generated by pulverization is mixed in the toner, and the basic characteristics of the toner such as charging property, fixing property, and heat storage stability are deteriorated.

  As a method for producing toner without pulverizing 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 obtain colored resin particles. The toner particles are formed and aggregated to obtain toner particles. However, when a toner is produced by this method, there is a problem that an environmental load increases because an organic solvent is used.

  As a method for producing 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 into an atmosphere at 20 ° C. and decompressed. To produce a toner.

  However, when a molten resin and a compressive fluid such as liquefied carbon dioxide are mixed, a homogeneous mixture cannot be obtained due to a difference in viscosity between the molten resin and the compressive fluid, and the viscosity of the mixture cannot be reduced. As a result, when the mixture is ejected from the nozzle and discharged, the mixture is solidified before being granulated, thereby causing a problem that granulation becomes impossible.

  The invention according to claim 1 includes a melting step in which a compressive fluid and a pressure plastic material are brought into contact with each other to melt the pressure plastic material, and a melt obtained by melting the pressure plastic material is injected. And a granulating step for granulating, wherein the melt has a viscosity of 500 mPa · s or less.

  As described above, according to the method for producing particles of the present invention, the compressive fluid and the pressure plastic material are brought into contact with each other. In this case, since the plasticization of the pressure plastic material is promoted by the pressure of the compressive fluid, the compressive fluid and the pressure plastic material can be mixed more uniformly. Thereby, since the melt obtained by melting the pressure plastic material can be reduced in viscosity, there is an effect that it is easy to granulate.

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

  Hereinafter, an embodiment of the present invention will be described. In the method for producing particles according to this embodiment, a compressive fluid and a pressure plastic material are brought into contact with each other to melt the pressure plastic material, and the obtained melt having a viscosity of 500 mPa · s or less is sprayed and granulated. In the present embodiment, “melting” means a state in which a raw material such as a pressure plastic material comes into contact with a compressive fluid and is plasticized or liquefied while swelling. Moreover, in this embodiment, a raw material is a material from which particles are manufactured, and means a material that is a constituent component of 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 pressure (horizontal axis) of a pressure plastic material. In this embodiment, the pressure plastic material is a material having a property of lowering the glass transition temperature (Tg) when pressure is applied. More specifically, the pressure plastic material is plasticized by applying pressure without applying heat. It means the material to be converted. A pressure plastic material plasticizes at a temperature below the glass transition temperature at atmospheric pressure of the pressure plastic material when pressure is applied, for example, by contact with a compressive fluid.

  FIG. 1 shows the relationship between the glass transition temperature (vertical axis) and 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. A material such as polystyrene, which has a negative slope of change in glass transition temperature with respect to applied pressure, can be said to be a pressure plastic material. This inclination varies depending on the type, composition, molecular weight, and the like of the pressure plastic 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./for crystalline polyester. It was -8 ° C / MPa in the case of MPa, polyol resin, -7 ° C / MPa in the case of urethane resin, -11 ° C / MPa in the case of polyarylate resin, and -10 ° C / MPa in the case of polycarbonate resin. In addition, this inclination can be determined based on the measurement result when changing a pressure and measuring a glass transition temperature using the C-80 high pressure calorimeter apparatus by SETARAM. In this case, after setting a sample in a high-pressure measurement cell and replacing the inside of the cell with carbon dioxide, the glass transition temperature can be measured by pressurizing to a predetermined pressure. In addition, the inclination can be determined based on the amount of change in the glass transition temperature when the pressure is changed from atmospheric pressure (0.1 MPa) to 10 MPa.

  The slope of the change in the glass transition temperature with respect to the pressure is preferably −1 ° C./MPa or less, more preferably −5 ° C./MPa or less, and further preferably −10 ° C./MPa or less. There is no limit to the lower limit of the slope. In addition, when this inclination is larger than −1 ° C./MPa, when pressure is applied without applying heat, plasticization becomes insufficient, and the melt cannot be lowered in viscosity, so that granulation becomes difficult. There is. Further, as the pressure plastic material, those having a viscosity of 500 mPa · s or less under conditions of 30 MPa or less are preferable. In this case, the pressure may be set to 500 mPa · s or less under conditions of 30 MPa or less by applying heat below the melting point at normal pressure to the pressure plastic material.

  The pressure plastic material is preferably a resin having at least a carbonyl structure — (C═O) —. The carbonyl structure consists of oxygen with high electronegativity and π bond with carbon, and π bond electrons are strongly attracted to oxygen, oxygen is negatively polarized, and carbon is positively polarized. Becomes higher. Further, when the compressive fluid is carbon dioxide, the carbonyl structure is similar to the structure of carbon dioxide, so it is presumed that the affinity between carbon dioxide and the pressure plastic material is increased. By these actions, the effect of plasticizing the pressure plastic material by the compressive fluid is enhanced. The pressure plastic material having at least a carbonyl structure is not particularly limited and may be appropriately selected depending on the intended purpose. For example, polyester resin, urethane resin, polyol resin, polyamide resin, rosin, modified rosin, terbene resin Etc. The pressure plastic material is not limited to those having a carbonyl structure, and can be appropriately selected depending on the purpose. For example, vinyl resin, epoxy resin, phenol resin, aliphatic or alicyclic hydrocarbon resin, Aromatic petroleum resins, chlorinated paraffin, paraffin wax, polyethylene, polypropylene, and the like can be mentioned. These pressure plastic materials may be used individually by 1 type, and may use 2 or more types together.

  There is no restriction | limiting in particular as a polyester resin, According to the objective, it can select suitably, For example, modified polyester, unmodified polyester, amorphous polyester, crystalline polyester, polylactic acid resin etc. are mentioned.

  There is no restriction | limiting in particular as a polylactic acid resin, According to the objective, it can select suitably, For example, a polylactic acid resin of a L-form, D-form, or a racemic body, a stereolactic acid polylactic acid resin, and a polylactic acid type | system | group Examples thereof include block copolymerization.

  A polyether polyol resin having an epoxy skeleton is used as the polyol resin, and (ii) an epoxy resin, (ii) an alkylene oxide adduct of a dihydric phenol or a glycidyl ether thereof, and (iii) an 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. There is no restriction | limiting in particular as a vinyl resin, According to the objective, it can select suitably, For example, styrene, such as polystyrene, poly p-chlorostyrene, polyvinyltoluene, and its substituted polymer; 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 Polymer, styrene-acrylonitrile copolymer, styrene-vinyl Styrene copolymers such as rumethyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-acrylonitrile-indene copolymer, styrene-maleic acid copolymer, styrene-maleic acid ester copolymer Combined; 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 a polymer of monomers such as vinyl pyridine and butadiene, a copolymer composed of two or more of these monomers, or a mixture thereof. There is no restriction | limiting in particular as said urethane resin, According to the objective, it can select suitably.

<Other raw materials>
In the manufacturing method of the present embodiment, other raw materials can be used in combination with the above-described pressure plastic resin, depending on the characteristics and processability of the particles to be manufactured. 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 this embodiment are toner.

(Coloring agent)
There is no restriction | limiting in particular as a coloring agent, According to the objective, it can select suitably from well-known pigments and dyes. The addition amount of these colorants is not particularly limited and may be appropriately selected depending on the degree of coloration, 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 colorant include carbon black, nigrosine dye, iron black, naphthol yellow S, Hansa yellow (10G, 5G, G), cadmium yellow, yellow iron oxide, ocher, yellow lead, 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, Red Dan, Lead Zhu, Cadmium Red, Cadmium Mercury Red, Antimony Zhu, Permanent Red 4R, Para Red, Faise Red, Parachlor Ortho Nitroaniline Red, Risor Fast Carlet G, Brilliant Fast Scarlet, Brilliant Carmine B, Permanent Red (F2R, F4R, FRL, FRLL, F4RH), Fast Scarlet VD, Belkan Fast Rubin B, Brilliant Scarlet G, Resol Rubin GX, Permanent Red F5R, Brilliant Carmine 6B, Pigment Scarlet 3B, Bordeaux 5B, Toluidine Maroon, Permanent Bordeaux F2K, Helio Bordeaux BL, Bordeaux 10B, Bon Maroon Light, Bon Maroon Medium, Eosin Lake, Rhodamine Lake B, Rhodamine Lake Y, Alizarin Lake, Thioindigo Red B, Thioindigo maroon, oil red, quinacridone red, pyrazolone red, polyazo red, chrome vermil , Benzidine Orange, Perinone Orange, Oil Orange, Cobalt Blue, Cerulean Blue, Alkaline Blue Lake, Peacock Blue Lake, Victoria Blue Lake, Metal Free Phthalocyanine Blue, Phthalocyanine Blue, Fast Sky Blue, Indanthrene Blue (RS, BC ), Indigo, Ultramarine Blue, Bituminous Blue, Anthraquinone Blue, Fast Violet B, Methyl Violet Lake, Cobalt Purple, Manganese Purple, Dioxane Violet, Anthraquinone Violet, Chrome Green, Zinc Green, Chrome 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, litbon, etc. are mentioned.

  Examples of the dye include C.I. I. SOLVENT YELLOW (6, 9, 17, 31, 35, 100, 102, 103, 105), C.I. I. SOLVENT ORANGE (2, 7, 13, 14, 66), C.I. I. 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. SOLVEN BLUE (22, 63, 78, 83-86, 191, 194, 195, 104), C.I. I. SOLVEN GREEN (24, 25), C.I. I. SOLVEN BROWN (3, 9) and the like. Commercially available dyes include Aizen SOT dyes Yellow-1,3,4, Orange-1,2,3, Scarlet-1, Red-1,2,3, Brown-2, Blue- manufactured by Hodogaya Chemical Co., Ltd. 1, 2, Violet-1, Green-1, 2, 3, Black-1, 4, 6, 8; Sudan dyes Yellow-146, 150, Orange-220, Red-290, 380, 460, manufactured by BASF Blue-670; Dialresin Yellow-3G, F, H2G, HG, HC, HL, Orange-HS, G, Red-GG, S, HS, A, K, H5B, Violet-D, Blue-, manufactured by Mitsubishi Kasei 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, Kaya Set Red-B manufactured by Nippon Kayaku Co., Ltd. And blue A-2R.

(Surfactant)
When the particles produced by the production method of the present embodiment are toner, 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 a compressive fluid and a portion having an affinity for a toner in the same molecule, and may be appropriately selected according to the purpose. it can. In the case where the first compressive fluid is carbon dioxide, as the surfactant, a fluorine-based surfactant, 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 Compounds having a parent carbon dioxide group such as are preferred. Among these, a fluorine-based surfactant, a silicone-based surfactant, a carbonyl group-containing compound, and a polyethylene glycol (PEG) group-containing compound are preferable. These surfactants may be oligomers or polymers.

  As the fluorine-based surfactant, a compound having a C 1-30 perfluoroalkyl group is suitably used. Among these, a high molecular weight fluorosurfactant is preferable from the viewpoint of the surface active ability, charging performance and durability performance when used as a toner. Here, an example of the structural unit of the fluorosurfactant is shown in the formula (1-1) and the formula (1-2).

R ₁ in the formula (1-1) and formula (1-2) is a hydrogen atom or a lower alkyl group having 1 to 4 carbon atoms (for example, 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 (eg, methylene group, ethylene group, propylene group, isoprene group, 2-hydroxypropylene group, butylene group, 2-hydroxybutylene group, etc.). Rf in the formula (1-1) and the formula (1-2) represents a perfluoroalkyl group or a perfluoroalkenyl group having 1 to 30 carbon atoms. Among these, 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. In addition, an oligomer or a polymer is formed by combining a plurality of structural units of formulas (1-1) and (1-2). In this case, in consideration of the affinity with the toner, a homopolymer, a block copolymer, a random copolymer or the like may be formed. Each end of the oligomer or polymer is not particularly limited, but is 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, a compound containing a polydimethylsiloxane (PDMS) group represented by the structural formula (2) is preferable. In consideration of affinity with the toner, these may be compounds such as homopolymers, block copolymers, and random copolymers.

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

  There is no restriction | limiting in particular as a carbonyl group containing compound, According to the objective, it can select suitably, For example, aliphatic polyester, polyacrylate, an acrylic resin etc. are mentioned. There is no restriction | limiting in particular as a PEG group containing compound, According to the objective, it can select suitably, For example, PEG group containing polyacrylate, polyethyleneglycol resin, etc. are mentioned.

  These surfactants polymerize vinyl monomers such as Rf group-containing vinyl monomers, PDMS group-containing vinyl monomers, PEG group-containing vinyl monomers, or copolymerize these vinyl monomers with other vinyl monomers. Can be obtained. Examples of vinyl monomers include styrene monomers, acrylate monomers, and methacrylate monomers. Many of these vinyl monomers are commercially available and can be used as appropriate according to the purpose. Further, as the surfactant, Rf group, PDMS group, PEG group can be used as the main chain of the oligomer or polymer, and COOH group, OH group, amino group, pyrrolidone skeleton, etc. can be introduced into the side chain. .

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

  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 is preferable) may be used as a solvent. Many compounds having a structure similar to polydimethylsiloxane are commercially available (see, for example, the catalog of AMAX Co.), and silicone surfactants can also be obtained 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)
There is no restriction | limiting in particular as a dispersing agent, According to the objective, it can select suitably, For example, organic particulates, inorganic particulates, etc. can be mentioned. Among these, acrylic modified inorganic fine particles, silicone modified inorganic fine particles, fluorine modified inorganic fine particles, fluorine-containing organic fine particles, silicone organic fine particles and the like are preferable, and acrylic modified inorganic fine particles are more preferable. These dispersants are preferably those that melt into the compressive fluid.

  Examples of the organic fine particles include silicone-modified products and fluorine-modified products of acrylic fine particles that are insoluble in the supercritical fluid. Inorganic fine particles include, for example, polyvalent metal phosphates such as calcium phosphate, magnesium phosphate, aluminum phosphate and zinc phosphate, carbonates such as calcium carbonate and magnesium carbonate, inorganic salts such as calcium metasuccinate, 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 those obtained by modifying 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 of modifying the surface of silica using 3- (Trimethoxysil) propyl methacrylate.

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 toner on the acrylate side. If the purpose is the same, surface modification may be performed by another method without using the method based on this 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 toner particle size control and toner charging performance.

(Release agent)
There is no restriction | limiting in particular as a mold release agent, According to the objective, it can select suitably from well-known things, For example, waxes etc. are mentioned suitably. 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 individually by 1 type and may use 2 or more types together.

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

  There is no restriction | limiting in particular as melting | fusing point of these mold release agents, Although it can select suitably according to the objective, 40 to 160 degreeC is preferable, 50 to 120 degreeC is more preferable, 60 to 90 degreeC is more preferable. A temperature of not higher than ° C is particularly preferred. If the melting point is less than 40 ° C., the heat resistant storage stability may be lowered. If the melting point exceeds 160 ° C., cold offset may easily occur at the time of fixing at a low temperature, and paper may be wound around a fixing machine. May occur. The cold offset means that, in the heat roller fixing method, the vicinity of the interface between the toner and the paper is not sufficiently melted so that a part of the toner image is removed by electrostatic adsorption, and is also called a low temperature offset.

  The addition amount of these release agents is not particularly limited and can be appropriately selected according to the purpose. However, it is preferably 1 part by mass or more and 20 parts by mass or less, and 3 parts by mass or more with respect to 100 parts by mass of the pressure plastic material. 15 parts by mass or less is more preferable. When the addition amount of the release agent is less than 1 part by mass, the effect of the release agent may not be sufficiently obtained, and when it is more than 20 parts by mass, the heat resistant storage stability may be lowered.

(Charge control agent)
The charge control agent is not particularly limited and can be appropriately selected from known ones according to the purpose. However, since a color tone may change when a colored one is used, a colorless or nearly white material is used. preferable. Examples of such charge control agents include nigrosine dyes, triphenylmethane dyes, chromium-containing metal complex dyes, molybdate chelate pigments, rhodamine dyes, alkoxy amines, quaternary ammonium salts (fluorine-modified quaternary ammonium salts). Salt), alkylamide, phosphorus alone or a compound thereof, tungsten alone or a compound thereof, fluorine-based activator, salicylic acid metal salt, salicylic acid derivative metal salt, and the like. Among these, salicylic acid metal salts and metal salts of salicylic acid derivatives are preferred. These may be used individually by 1 type and may use 2 or more types together. There is no restriction | limiting in particular as a metal used for a metal salt, According to the objective, it can select suitably, For example, aluminum, zinc, titanium, strontium, boron, silicon, nickel, iron, chromium, zirconium, etc. are mentioned. It is done.

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

  The addition amount of these charge control agents is not particularly limited and may be appropriately selected depending on the purpose. However, it is preferably 0.5 parts by mass or more and 5 parts by mass or less with respect to 100 parts by mass of the pressure plastic material. More preferred is 3 parts by mass or more. When the addition amount is less than 0.5 parts by mass, the charging characteristics of the toner may be deteriorated. When 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. The electrostatic attraction force with the developing roller is increased, and the fluidity of the developer and the image density may be reduced.

(Crystalline polyester)
The crystalline polyester is not particularly limited and can be appropriately selected from known ones according to the purpose. However, the crystalline polyester has a sharp molecular weight distribution and a low molecular weight in terms of excellent low-temperature fixability. Is preferred. As such a crystalline polyester, the molecular weight M distribution by GPC of soluble part of o-dichlorobenzene has a peak position of 3 in the molecular weight distribution chart in which the horizontal axis represents log (M) and the vertical axis represents mass%. 0.5 to 4.0, 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, More preferably, 000 or less and Mw / Mn of 2 or more and 8 or less.

The melting point and 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 higher and 150 ° C. or lower. Here, the F1 / 2 temperature is a sample of 1 cm ² under the conditions of an elevated flow tester CFT-500 (manufactured by Shimadzu Corporation), a die diameter of 1 mm, a pressure of 10 kg / cm ² , and a heating rate of 3 ° C./min. Measured at a temperature corresponding to ½ from the outflow start point to the end point of the outflow when melted out. When the melting point and F1 / 2 temperature are less than 50 ° C., heat-resistant storage stability is deteriorated, and blocking easily occurs at the temperature inside the developing device. Cannot be obtained.

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

  The addition amount of the crystalline polyester is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 0 part by mass or more and 900 parts by mass or less, and 0.5 parts by mass with respect to 100 parts by mass of the pressure plastic material. The amount is more preferably 500 parts by mass or less, and particularly preferably 1 part by mass or more and 100 parts by mass or less. When the addition amount is less than 1 part by mass, the low-temperature fixability may not be exhibited, and when it exceeds 900 parts by mass, the hot offset property may be deteriorated.

(Other ingredients)
Examples of other components that may be used together with the pressure plastic material include a fluidity improver and a cleaning property improver. The fluidity improver means a material that can surface-treat the toner to increase hydrophobicity and prevent deterioration of fluidity and charging characteristics even under high humidity. Examples of fluidity improvers include silane coupling agents, silylating agents, silane coupling agents having an alkyl fluoride group, organic titanate coupling agents, aluminum coupling agents, silicone oils, and modified silicone oils. Illustrated.

  The cleaning property improving agent means an agent added to the toner composition in order to remove the transferred developer remaining on the photosensitive member or the primary transfer medium. Examples of such cleaning improvers include fatty acid metal salts such as zinc stearate, calcium stearate, stearic acid, polymer fine particles produced by soap-free emulsion polymerization such as polymethyl methacrylate fine particles, polystyrene fine particles, and the like. . The fine polymer particles preferably have a relatively narrow particle size distribution, and those having a volume average particle size of 0.01 μm or more and 1 μm or less are suitable.

<< Compressive fluid >>
Next, the 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. A compressible fluid has properties such as rapid mass transfer and heat transfer and low viscosity, and its density, dielectric constant, solubility parameter, free volume, etc. change continuously and greatly by changing temperature and pressure. It has the property to do. Since the compressive fluid has an extremely low interfacial tension as compared with the organic solvent, even a minute undulation (surface) can follow and be wetted with the compressive fluid. Further, by returning the compressive fluid to normal pressure, it can be easily separated from the product such as toner, and can be recovered and reused. Thereby, in the manufacturing method of this embodiment, compared with the case where water, an organic solvent, etc. are used, the load to the environment at the time of manufacture can be reduced.

  In the present embodiment, the “compressible fluid” means that a substance exists in any of the regions (1), (2), and (3) shown in FIG. 3 in the phase diagram shown in FIG. It means the state of time. In such a region, it is known that the substance has a very high density and behaves differently from that at normal temperature and pressure. In addition, when a substance exists in the area | region of (1), it becomes a supercritical fluid. A supercritical fluid is a fluid that exists as a non-condensable high-density fluid in a temperature and pressure region that exceeds the limit (critical point) at which gas and liquid can coexist, and does not condense even when compressed. Further, when the substance is present in the region (2), it becomes a liquid, but in this embodiment, it is obtained by compressing a substance that is in a gaseous state at normal temperature (25 ° C.) and normal pressure (1 atm). Represents liquefied gas. Further, when the substance is present in the region (3), it is in a gaseous state, but in the present embodiment, it represents a high pressure gas whose pressure is 1/2 (1/2 Pc) or more of the critical pressure (Pc).

  In the present embodiment, examples of substances that can be used as the compressive fluid include carbon monoxide, carbon dioxide, dinitrogen monoxide, 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 compressive fluid for melting the pressure plastic material (hereinafter also referred to as the first compressive fluid) is not particularly limited, but can easily create a supercritical state and is nonflammable. In the case of producing toner, carbon dioxide is preferably used because a toner having a hydrophobic surface can be obtained. Carbon dioxide has good affinity with the carbonyl structure.

  In the manufacturing method of the present embodiment, a second compressive fluid may be used separately from the first compressive fluid. The second compressive fluid is supplied to the melt when the melt is ejected. Examples of the second compressive fluid include, but are not particularly limited to, substances that can be used as the compressible fluid described above. However, the second incompressible fluid is a substance such as oxygen or nitrogen having a maximum inversion temperature of 800 K or less, and includes nitrogen. A sex fluid 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 620K and a lower maximum reversal temperature than substances such as carbon dioxide (maximum reversal temperature 1500K). Thereby, the temperature reduction based on the Joule-Thomson effect when the nitrogen pressure is reduced is smaller than that when the pressure of carbon dioxide or the like is reduced. On the other hand, if the maximum reversal temperature of the second compressive fluid is too high, such as carbon dioxide, when the melt is injected, cooling due to the Joule-Thompson effect becomes excessive, and the melt becomes particles. By solidifying before, a fibrous or coalesced product may be mixed. In addition, when the cooling is excessive, the melt is solidified 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 over a long period of time.

  Moreover, in this embodiment, a compressive fluid can also be used 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.

  In addition, when the particles produced by the production method of the present embodiment are toner, other fluids can be used in combination with the compressive fluid. The other fluid is preferably one that can easily control the solubility of the toner composition. Specific examples include methane, ethane, propane, butane, ethylene and the like.

<< Particle production equipment >>
Subsequently, the particle manufacturing apparatus used in the present embodiment will be described with reference to FIGS. 4 to 6. 4 to 6 are schematic views showing an example of the particle manufacturing apparatus. First, the particle manufacturing apparatus 1 will be described with reference to FIG. The particle manufacturing apparatus 1 includes a cylinder 11, a pump 12 a, a valve 13 a, a high-pressure cell 14, a pump 12 b, a valve 13 b, and a nozzle 32 that are connected by ultra high pressure pipes (30 a, 30 b, 30 c, 30 d, 30 e, 30 f). .

  The cylinder 11 is a pressure vessel for storing and supplying the first compressive fluid. The cylinder 11 may store a gas (gas) or a solid that is a compressible fluid in the course of being supplied to the high-pressure cell 14 or heated or pressurized in the high-pressure cell 14. 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 12a is a device that sends out the compressible fluid stored in the cylinder 11 to the high-pressure cell 14 side. 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 block the flow rate of the compressive fluid.

  The high pressure cell 14 has a temperature regulator, and a compressive fluid supplied via the valve 13a and a pressure plastic material previously filled in the high pressure cell 14 are brought into contact with each other at a predetermined temperature. An apparatus for melting a material. A back pressure valve 14a is attached to the high pressure cell 14, and the pressure in the high pressure cell 14 can be adjusted by opening and closing the back pressure valve 14a. In addition, a stirring device is attached to the high-pressure cell 14 so that the compressive fluid and the pressure plastic material can be stirred and mixed.

  The pump 12b is a device that sends the melt in the high-pressure cell 14 to the nozzle 32 side. The valve 13b is a device for adjusting or blocking the flow rate of the melt obtained by opening and closing the path between the pump 12b and the nozzle 32 and melting the pressure plastic material. The nozzle 32 is a device that is provided at an end of the ultrahigh pressure pipe 30f and injects a melt. Although it does not specifically limit as a kind of nozzle 32, A direct injection nozzle is used suitably. The diameter of the nozzle 32 is not particularly limited as long as the pressure at the time of injection can be maintained constant, but if it is too large, the melt viscosity increases due to the pressure at the time of injection being too low, making it difficult to obtain fine particles. There is. Moreover, the supply pump for maintaining the pressure may need to be enlarged. On the other hand, when the nozzle diameter is too small, the melt is likely to be clogged with the nozzle 32, and it may be difficult to obtain the targeted fine particles. Therefore, the upper limit of the nozzle diameter is preferably 500 μm or less, more preferably 300 μm or less, and even more preferably 100 μm or less. Moreover, as a minimum of a nozzle diameter, it is preferable that it is 5 micrometers or more, It is more preferable that it is 20 micrometers or more, It is further more preferable that it is 50 micrometers or more.

  In the particle manufacturing apparatus 1, the melt in the high-pressure cell 14 is not directly injected, but is injected from the nozzle 32 after passing through the ultrahigh-pressure pipes (30d, 30e, 30f). As a result, the compressive fluid mixed in the high pressure cell 14 is sufficiently diffused into the pressure plastic material, so that the workability is improved.

  Next, the particle manufacturing apparatus 2 will be described with reference to FIG. In the description of the particle manufacturing apparatus 2, means, mechanisms, apparatuses, and the like that are common to the particle manufacturing apparatus 1 of FIG. 4 are denoted by the same reference numerals and description thereof is omitted.

  The particle manufacturing apparatus 2 includes a cell 24, a pump 12b, a valve 13b, a mixing device 17, a valve 13c, and a nozzle 32 which are connected by ultra high pressure pipes (30d, 30e, 30j, 30k, 30f). In the particle manufacturing apparatus 2, the valve 13a is connected to the mixing apparatus 17 by an ultrahigh pressure pipe 30c. Further, a heater 16 is provided in the super high pressure pipe 30c.

  The cylinder 11 is a pressure vessel for storing and supplying the first compressive fluid. The cylinder 11 may store a gas (gas) or solid that is heated by the heater 16 or pressurized by the pump 12a to become a compressible fluid. 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 cell 24 has a temperature controller and is a device for heating the pressure plastic material previously filled in the cell 24. A stirring device is attached to the cell 24, whereby the pressure plastic material can be stirred and heated uniformly.

  The mixing device 17 is a device that continuously contacts and mixes the pressure plastic material supplied from the cell 24 and the first compressive fluid supplied from the cylinder 11. Specific examples of the mixing device 17 include a known T-shaped joint, a swirl mixer that positively utilizes a swirl flow, and a center collision type mixer in which two liquids collide in a mixing unit. The valve 13c is a device for adjusting or blocking the flow rate of the melt by opening and closing the path between the mixing device 17 and the nozzle 32.

  When the particle manufacturing apparatus 2 is used, particles can be manufactured without using the high-pressure cell 14, and the apparatus can be reduced in weight. In the particle manufacturing apparatus 2, the pressure plastic material supplied from the cell 24 and the first compressive fluid supplied from the cylinder 11 are continuously brought into contact with each other by the mixing device 17 so that the pressure plastic material is melted in advance. . Thereby, since a compressive fluid and a pressure plastic material can be mixed with a fixed ratio, a homogeneous melt can be obtained.

  Next, the particle manufacturing apparatus 3 will be described with reference to FIG. In the description of the particle manufacturing apparatus 3, means, mechanisms, apparatuses, and the like that are common to the particle manufacturing apparatus 2 of FIG. 5 are denoted by the same reference numerals and description thereof is omitted.

  The particle manufacturing apparatus 2 includes a cylinder 21, a pump 22, and a valve 23 that are connected by an ultrahigh pressure pipe (30 g, 30 h). In addition, the particle manufacturing apparatus 2 includes a mixing device 31 that is connected to the nozzle 32, connected to the valve 13c by the ultrahigh pressure pipe 30f, and connected to the valve 23 by the ultrahigh pressure pipe 30i. A heater 16 is provided in the ultra high pressure pipe 30i.

  The cylinder 21 is a pressure vessel for storing and supplying the second compressive fluid. The cylinder 21 may store a gas (gas) or a solid that is heated by the heater 26 or pressurized by the pump 22 to become a compressible fluid. In this case, the gas or solid stored in the cylinder 21 is heated or pressurized 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 compressible fluid stored in the cylinder 21 in the direction of the mixing device 31. The valve 23 is a device for adjusting or blocking the flow rate of the compressive fluid by opening and closing a path between the pump 22 and the mixing device 31.

  The mixing device 31 is a device that mixes the melt supplied from the mixing device 17 and the second compressive fluid supplied from the cylinder 21 by continuously contacting them. Specific examples of the mixing device 31 include a known T-shaped joint, a swirl mixer that positively utilizes a swirl flow, and a center collision type mixer in which two liquids collide in a mixing unit.

  In the particle manufacturing apparatus 3, the melt is injected from the nozzle 32 while supplying the second compressive fluid to the melt by the mixing device 31. In this case, the viscosity of the melt of the pressure plastic material can be lowered by the pressure of the second compressive fluid, so that the 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.

  In the particle production apparatus (1, 2, 3), a known joint or the like is used as the mixing apparatus (17, 31). By the way, when mixing fluids having different viscosities such as a molten resin and a compressible fluid using a static mixer as described in Patent Document 3, it is difficult to mix both fluids homogeneously. 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 around the tube axis. In the case of using this static mixer, the fluid is mixed by being divided, converted, and inverted by an element installed in the pipe in the process of moving in the tubular housing. Another type of static mixer is known in which a large number of elements composed of honeycomb-shaped plates composed of polygonal chambers are arranged in a superposed manner. In such a static mixer, the fluid is mixed by being subjected to dispersion, inversion, and vortex action by sequentially moving a small chamber inside the tube from the center to the outside in the tube and from the outside to the center.

  However, when a high-viscosity fluid such as a resin and a low-viscosity fluid such as a compressive fluid are passed through these static mixers, the low-viscosity fluid is not subjected to the mixing action by the element, and the in-tube element and the tube housing It will pass through the gaps of and can not be mixed homogeneously. As countermeasures for mixing failure, methods such as complication of element structure and lengthening of the mixer can be considered, but these countermeasures are not effective prevention measures for low-viscosity fluid flow-through phenomenon. This causes problems such as an increase in pressure loss, an increase in size of the apparatus, and an increase in cleaning labor.

<< Each step of particle production >>
Then, each process when manufacturing the toner as an example of particle | grains using a particle manufacturing apparatus (1,2,3) is demonstrated. The method for producing particles of the present embodiment includes a melting step in which a compressive fluid and a pressure plastic material are brought into contact with each other to melt the pressure plastic material, and a melt having a viscosity of 500 mPa · s or less obtained by melting the pressure plastic material. And a granulating step of granulating the body by spraying.

<Melting process>
First, the melting step in the method for producing particles of this embodiment will be described. As described above, in this embodiment, “melting” means a state in which a raw material such as a pressure plastic material comes into contact with a compressive fluid and is plasticized or liquefied while swelling. Conventionally, a method for precipitating a substance in a supercritical fluid through a pressure reduction process is known as a rapid expansion of supercritical solutions (RESS) method. A discharge target used in a method known as the RESS method is obtained by dissolving a solute material in a compressible fluid, and the compressible fluid and the solute material are in a uniform state. On the other hand, in the present embodiment, a gas saturated solution suspension (PGSS) method is used. As described above, the melt to be discharged in the PGSS method is obtained by reducing the viscosity of the pressure plastic material by contacting and moistening the compressive fluid in the pressure plastic material. An interface exists between the body and the body. That is, the discharge target in the RESS method is a phase of a compressible fluid-solid equilibrium state, whereas in the PGSS method, it is a phase of a compressible fluid-liquid equilibrium state, and the same compressive fluid is used. Even in the discharge method, the phase state before discharge of the discharge target is different.

  When the particle manufacturing apparatus 1 is used, in the melting step, first, raw materials such as a pressure plastic material and a colorant are filled in the high pressure cell 14. In this case, when the raw material includes a plurality of components, these components may be mixed in advance with a mixer or the like and melt-kneaded with a roll mill or the like before the raw material is filled. Next, the high pressure cell 14 is sealed, and the raw material is stirred by the stirring device of the high pressure cell 14. Subsequently, the pump 12 a is operated to pressurize the first compressive fluid stored in the cylinder 11 and the valve 13 a is opened to supply the first compressive fluid into the high-pressure cell 14. In the present embodiment, a carbon dioxide (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 can be appropriately selected depending on the purpose, but is preferably not higher than the thermal decomposition temperature of the pressure plastic material under atmospheric pressure, and the melting point temperature. The following is more preferable. In the present embodiment, the thermal decomposition temperature means a starting temperature of weight reduction accompanying thermal decomposition of a sample in measurement by a thermal analyzer (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 chain is broken to deteriorate the durability, and the color tone and transparency of the toner as a product are decreased. , Fixing properties, heat-resistant storage stability, and charging performance are deteriorated. In addition, energy consumption due to 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 according to the purpose. The above is preferable, 10 MPa or more and 200 MPa or less is more preferable, and 31 MPa or more and 100 MPa or less is particularly preferable. If the pressure in the high-pressure cell 14 is less than 1 MPa, a plasticizing effect that can granulate the pressure-plastic material may not be obtained. No matter how high the pressure in the high-pressure cell 14 is, there is no problem, but the higher the pressure, the heavier the apparatus and the higher the equipment cost.

  In the high-pressure cell 14, the pressure plastic material melts when the compressive fluid and the raw material including the pressure plastic material come into contact with each other. In this case, the melt is stirred by the stirring device 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 is a viscosity that can be ejected by the nozzle 32. However, the lower the viscosity, the smaller the nozzle diameter, and the easier it is to spray. For this reason, the viscosity of the melt is preferably 500 mPa · s or less, more preferably 300 mPa · s or less, and further preferably 100 mPa · s or less, in order to obtain a toner that realizes high image quality. Is preferably 20 mPa · s or less. When the viscosity of the melt is larger than 500 mPa · s, it may be difficult to form particles, or coarse particles, fibrous materials, foaming, coalescence, and the like may occur. In this embodiment, since the pressure plastic material is used, the pressure of the compressive fluid promotes the lowering of the viscosity of the pressure plastic material. Therefore, the pressure plastic material and the compressive fluid are homogeneously mixed to reduce the pressure. A viscous melt is obtained.

  When using the particle production apparatus (2, 3), in the melting step, first, raw materials such as a pressure plastic material and a colorant are filled in the cell 24. In this case, when the raw material includes a plurality of components, these components may be mixed in advance with a mixer or the like and melt-kneaded with a roll mill or the like before the raw material is filled. Next, the cell 24 is sealed, 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. As a result, the pressure plastic material is plasticized.

  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 (carbon dioxide) cylinder is used as the cylinder 11. The supplied first compressive fluid is heated by the heater 16 in the ultra high 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 and the valve 13b is opened. As a result, the pressure plastic material supplied from the cell 24 and the first compressive fluid supplied from the cylinder 11 are continuously brought into contact with each other by the mixing device 17 and mixed uniformly. Thereby, the pressure plastic material is melted. The viscosity of the melt obtained by melting the pressure plastic material is preferably 500 mPa · s or less, more preferably 300 mPa · s or less, and more preferably 100 mPa · s or less, as described above. In order to obtain a toner that achieves high image quality, it is preferably 20 mPa · s or less. In the particle production apparatus (2, 3), the pressure plastic material is plasticized in advance in the cell 24, thereby reducing the difference in viscosity between the pressure plastic material and the compressive fluid as much as possible, and bringing them into contact with each other for mixing. Therefore, a more homogeneous melt can be obtained. In the cell 24, the pressure plastic material is plasticized by heat in advance, but the pressure plastic material may be plasticized by pressure, or the pressure plastic material may be plasticized by heat and pressure in advance.

<Granulation process>
Then, the granulation process in the manufacturing method of particle | grains is demonstrated. When the particle production apparatus (1, 2) is used, the mixture obtained by contacting the compressive fluid and the pressure plastic material in the high pressure cell 14 or the mixing apparatus 17 is ejected from the nozzle 32 by opening the valve 13c. To do. At this time, the back pressure valve 14a, the pumps (12a, 12b), the temperature regulator, and the like are controlled so that the temperature and pressure of the high pressure cell 14 or the cell 24 are maintained constant. In this case, the magnitude of the pressure in the high pressure cell 14 or the mixing device 17 is not particularly limited. The melt sprayed from the nozzle 32 becomes particles and then solidifies. When the particle production apparatus 2 is used, the pressure plastic material and the compressive fluid are continuously brought into contact with each other by the mixing device 17 and the obtained melt is supplied to the nozzle 32. Can be granulated.

  When using the particle manufacturing apparatus 3, first, the pump 22 is operated to open the valve 23, thereby supplying the second compressible fluid stored in the cylinder 21 to the mixing apparatus 31. In the present 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 can be appropriately selected according to the purpose, but is preferably 1 MPa or more, more preferably 10 MPa or more and 200 MPa or less, and particularly 31 MPa or more and 100 MPa or less. preferable. If the pressure applied to the second compressive fluid is less than 1 MPa, a plasticizing effect that can granulate the pressure plastic material may not be obtained. No matter how high the pressure is, there is no problem, 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 ultra high pressure pipe 30i. The set temperature of the heater 26 is not particularly limited as long as the supplied nitrogen is a temperature at which the supplied nitrogen becomes a compressive fluid.

  Next, the pumps (12 a, 12 b) are operated to supply the melt of pressure plastic material from the mixing device 17 to the mixing device 31. At this time, the pumps (12a, 12b), the temperature regulator, and the like are controlled so that the temperature and pressure in the cell 24 are kept constant. In this case, the pressure in the cell 24 is not particularly limited, but may be equal to the pressure of the compressive fluid supplied from the second path. The melt supplied from the mixing device 17 and the second compressive fluid supplied from the cylinder 21 are uniformly mixed by the mixing device 31. Thereby, a melt can be injected under atmospheric pressure from a nozzle 32 by a pressure difference, supplying the 2nd compressive fluid to a melt.

  In this case, since the solid content concentration of the melt injected by the supply of the second compressive fluid is lowered, the viscosity of the melt can be further reduced. As a result, not only the temperature of the injected melt is controlled to be constant, but also the injection speed (outlet linear velocity) is increased, and the shearing force on the melt due to the improvement in the outlet linear velocity is also increased. Further, by using nitrogen as the second compressive fluid, the temperature drop due to the Joule-Thomson effect accompanying the pressure change in the vicinity of the nozzle 32 is alleviated, so that the nozzle 32 is less likely to be clogged. The melt sprayed from the nozzle 32 becomes particles and then solidifies. In this case, uniform fine particles without coalescence can be obtained over a long period of time due to the synergistic effect of lowering the viscosity of the melt and lowering the solid content. Moreover, the effect that the shape of the particle | grains manufactured is stabilized uniformly is acquired. When the particle production apparatus 3 is used, the pressure plastic material and the compressive fluid are continuously brought into contact with the mixing apparatus 17 and the obtained melt is supplied to the nozzle 32. Can be granulated.

<<< Particle >>>
In the present embodiment, an example of producing a toner has been described. However, the produced particles are not limited thereto, and may be appropriately selected according to the purpose, and may be particles such as daily necessities, pharmaceuticals, and cosmetics. The shape, size, material, and the like of the particles produced by the production method of the present embodiment are appropriately selected according to the purpose of the product and are not particularly limited. According to the production method of the present embodiment, particles can be produced without using an organic solvent by using a compressive fluid. Thereby, the particle | grains which do not contain an organic solvent substantially are obtained. In addition, that a particle | grain does not contain an organic solvent substantially means that content of the organic solvent in the particle | grains measured with the following measuring methods is below a detection limit.

(Measurement method of 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 with ultrasonic waves for 30 minutes, the mixture is stored in a refrigerator (5 ° C.) for 1 day or longer to extract the solvent in the particles. The supernatant is analyzed by gas chromatography (GC-14A, SHIMADZU), and the solvent concentration is measured by quantifying the solvent and residual monomers in the particles. 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 2.5kg / 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 ° C

  Moreover, the particle | grains of this embodiment may have a cavity inside, when a compressive fluid changes to gas at a granulation process. In this case, the average of the maximum ferret diameter of this cavity is 10 nm or more and less than 500 nm, and preferably 10 nm or more and less than 300 nm. The maximum ferret diameter is a diameter at which the interval between parallel lines is the largest when the target is sandwiched between parallel lines. The average of the maximum ferret diameter of the cavity is determined as follows. The cross section of the particle is observed with an electron microscope or the like, a cross-sectional photograph is taken, and the cross-sectional photograph is processed and binarized using image processing software to identify the cavity. Thirty points are selected in descending order of the diameter of the identified maximum ferret diameter of the cavity, and the average is taken as the average of the maximum ferret diameter of the cavity.

  When the particles have cavities, for example, when used as toner, it is possible to reduce power consumption when fixing the toner on the recording material. Further, the added external additive such as hydrophobic silica is difficult to be buried and the life of the toner is prolonged. Furthermore, since it is possible to reduce the agitation stress applied when charging by mixing with the carrier, there is an effect that energy required for the agitation can be reduced.

<< Toner >>
The toner manufactured by the manufacturing method of the present embodiment is not particularly limited in terms of characteristics such as shape and size, but the following image density, average circularity, mass average particle diameter, mass average particle diameter And the ratio of the number average particle diameter (mass average particle diameter / number average particle diameter).

  The toner image density is preferably 1.90 or more, more preferably 2.00 or more, and 2.10 or more, as measured by a spectrometer (X-Light, 938 Spectrodensitometer). Particularly preferred. If the image density is less than 1.90, the image density may be low and high image quality may not be obtained. Here, the image density is, for example, imagio Neo 450 (manufactured by Ricoh Co., Ltd.), and the amount of developer attached to copy paper (TYPE6000 <70W>, manufactured by Ricoh Co., Ltd.) A solid image of cm2 is formed with a surface temperature of the fixing roller of 160 ± 2 ° C., and the image density at any six positions in the obtained solid image is measured using the spectrometer, and the average value is calculated. Can be measured.

  The average circularity of the toner is a value obtained by dividing the circumference of an equivalent circle having the same projected shape as the shape of the toner by the circumference of the actual particle, and is preferably 0.900 or more and 0.980 or less, preferably 0.950 or more. 0.975 or less is more preferable. Moreover, it is preferable that the particle | grains whose average circularity is less than 0.94 are 15 mass% or less. If the average circularity is less than 0.900, satisfactory transferability and high-quality images without dust may not be obtained. If the average circularity exceeds 0.980, in an image forming system employing blade cleaning or the like, a cleaning failure occurs on the photosensitive member or the transfer belt, and dirt on the image, for example, a photographic image, etc. In the case of image formation with a high image area ratio, the toner on which an untransferred image has been formed due to poor paper feed or the like may become a transfer residual toner on the photosensitive member, resulting in background smearing of the accumulated image. Or, it may contaminate the charging roller for charging the photoreceptor in contact with the photosensitive member, and the original charging ability may not be exhibited.

Here, the average circularity can be measured using a flow particle image analyzer (Flow Particle Image Analyzer), for example, a flow particle image analyzer FPIA-2000 manufactured by Toa Medical Electronics Co., Ltd. In this case, fine dust is removed through a filter, and as a result, the number of particles in the measurement range (for example, an equivalent circle diameter of 0.60 μm or more and less than 159.21 μm) is adjusted to 20 or less in 10 ⁻³ cm ³ water. Prepare the prepared water. Next, several drops of a nonionic surfactant (preferably Contaminone N manufactured by Wako Pure Chemical Industries, Ltd.) is added to 10 ml of water containing the particles, and 5 mg of a measurement sample is added, and an ultrasonic disperser (manufactured by SMT) , UH-50) for 1 minute under the conditions of 20 kHz and 50 W / 10 cm 3, and further for a total of 5 minutes. A sample dispersion in which the particle concentration of the measurement sample obtained by the dispersion treatment is 4,000 / 10 ⁻³ cm ³ or more and 8,000 / 10 ⁻³ cm ³ or less (for particles in the equivalent diameter range of the measurement circle) 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 average circularity is measured by passing the sample dispersion through a flat and flat transparent flow cell (thickness: about 200 μm) flow path (expanding along the flow direction). Here, in order to form an optical path that crosses and passes through the thickness of the flow cell, the strobe and the CCD camera are mounted on the flow cell so as to be located on opposite sides of each other. While the sample dispersion is flowing, strobe light is irradiated at 1/30 second intervals to obtain an image of the particles flowing through the flow cell. As a result, each particle is photographed as a two-dimensional image having a certain 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.

  Thereby, 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 particles having the prescribed equivalent circle diameter are calculated. The result (frequency% and cumulative%) can be obtained by dividing the range from 0.06 μm to 400 μm into 226 channels (divided into 30 channels for one octave). In actual measurement, particles are measured in the 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, but is preferably 3 μm or more and 10 μm or less, and more preferably 3 μm or more and 8 μm or less. When the mass average particle size is less than 3 μm, in the case of a two-component developer, the toner may be fused to the surface of the carrier during a long period of stirring in the developing device, and the charging ability of the carrier may be reduced. In the case of the agent, toner filming on the developing roller and toner thinning are likely to cause toner fusion to a member such as a blade. Further, if the mass average particle diameter exceeds 10 μm, it becomes 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 toner particle diameter 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, the two-component developer has a toner on the surface of the carrier during long-term agitation in the developing device. May be fused to reduce 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, with one-component developer, filming of toner on the developing roller, The toner is thinned and toner fusion to a member such as a blade is likely to occur. Also, it becomes difficult to obtain a high-resolution and high-quality image, and the balance of the toner in the developer is reduced. In such a case, the toner particle size may vary greatly.

  For the mass average particle size and the ratio of the mass average particle size to the number average particle size (mass average particle size / number average particle size), for example, a particle size measuring device “Coulter Counter TAII” manufactured by Coulter Electronics Co., Ltd. is used. Can be measured.

<< Developer >>
Next, the developer according to this 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 according to the purpose. Specific examples of the developer include a one-component developer having a toner manufactured by the above-described manufacturing method and a two-component developer having a toner and a magnetic carrier manufactured by the above-described manufacturing method. May be. Examples of the toner include colored toners such as yellow, cyan, magenta, and black, and clear toner.

(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 5% by mass or more and 50% by mass or less, and more preferably 10% by mass or more and 30% by mass or less with respect to 100 parts by mass of the toner.

<< Image forming apparatus >>
Next, the image forming apparatus according to the present embodiment will be described with reference to FIG. FIG. 7 is a schematic diagram showing 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, and transfers and fixes the visible image onto a sheet as an example of a recording medium. Form an image. In this 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 illustrated in FIG. 7, the image forming apparatus 200 includes a paper feeding unit 210, a transport unit 220, an image forming unit 230, a transfer unit 240, and a fixing unit 250.

  As shown in FIG. 7, the paper feeding unit 210 includes a paper feeding cassette 211 in which papers to be fed are stacked, and a paper feeding roller 212 that feeds the papers stacked in the paper feeding cassette 211 one by one. It has.

  The transport unit 220 waits between a roller 221 that transports the paper fed by the paper feed roller 212 in the direction of the transfer unit 240 and the leading end of the paper transported by the roller 221, and the paper is loaded at a predetermined timing. A pair of timing rollers 222 that are sent 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 the paper discharge tray 224 are provided.

  The image forming unit 230 includes 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 cyan toner (toner C), an image forming unit M using a developer having magenta toner (toner M), and a black toner (toner K). The image forming unit K using the developed developer and an exposure device 233 are provided. Each of the toners (Y, C, M, K) is a toner obtained by the above manufacturing method.

  In FIG. 7, the four image forming units have substantially the same mechanical configuration except that the developers used are different. Each image forming unit is rotatably provided in FIG. 7, and is provided with a photosensitive drum (231Y, 231C, 231M, 231K) that carries an electrostatic latent image and a toner image, and a photosensitive drum (231Y, 231C, 231M). , 231K) to uniformly charge the surface of each of the chargers (232Y, 232C, 232M, 232K) and the toner cartridges (237Y, 237C, 237M, 237K) for supplying the toners (Y, C, M, K) of the respective colors. 237K) and an electrostatic latent image formed on the surface of the photosensitive drum (231Y, 231C, 231M, 231K) by the exposure device 233 using toner supplied from the toner cartridge (237Y, 237C, 237M, 237K). Each developing device (234Y, 234C, 234M, 234K) for developing the image, and toner on the transfer medium The static eliminators (235Y, 235C, 235M, 235K) for neutralizing the surface of the photosensitive drum (231Y, 231C, 231M, 231K) after the primary transfer of the toner and the static eliminators (235Y, 235C, 235M, 235K) And cleaning devices (236Y, 236C, 236M, 236K) for removing transfer residual toner remaining on the surfaces of the photosensitive drums (231Y, 231C, 231M, 231K).

  The exposure unit 233 reflects the laser light L emitted from the light source 233a based on the image information by the polygon mirrors (233bY, 233bC, 233bM, 233bK) that are rotationally driven by a motor, and the photosensitive drums (231Y, 231C, 231M). , 231K). As a result, an electrostatic latent image based on the image information is formed on the photosensitive drum 231.

  The transfer unit 240 includes a drive roller 241 and a driven roller 242, an intermediate transfer belt 243 as a transfer medium that is stretched over these rollers and can rotate counterclockwise in FIG. 7 as the drive roller 241 is driven, and an intermediate transfer belt A primary transfer roller (244Y, 244C, 244M, 244K) provided opposite to the photosensitive drum 231 with the belt 243 interposed therebetween, and a secondary opposing roller with the intermediate transfer belt 243 interposed at the transfer position of the toner image onto the paper. And a secondary transfer roller 246 provided to face the H.245.

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

  The fixing unit 250 is provided with a heater inside, and a heating roller 251 that heats the paper to a temperature higher than the fixing lower limit temperature of the toner, and a contact surface (nip portion) by pressing the heating roller 251 so as to be rotatable. ) To form a pressure roller 252. In the present 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 produced by the production method of the present embodiment having a sharp particle size distribution and good toner characteristics such as chargeability, environmental properties, and stability over time is used. A high-quality image can be formed.

<< Supplement of Embodiment >>
In each of the above embodiments, the case where the manufacturing apparatus used in the particle manufacturing method is the particle manufacturing apparatus (1, 2, 3) shown in FIGS. 4 to 6 is described, but the present invention is not limited to this.

  Although the said embodiment demonstrated the case where the melt containing a pressure plastic material and a compressive fluid was injected in air | atmosphere, it does not restrict to this. In this case, the melt can be injected into an environment in which the pressure of the melt is higher than that in the atmosphere and the pressure is lower than in the nozzle 32. In this case, controllability of the particle size and particle size distribution can be improved by controlling the injection speed (exit linear velocity). Further, in this case, since the cooling by the Joule-Thomson effect of the melt sprayed from the nozzle 32 can be mitigated, the heating of the heater 26 can be suppressed, and effects such as energy saving and cost reduction can be obtained.

EXAMPLES Next, although an Example and a comparative example are given and this invention is demonstrated more concretely, this invention is not restrict | limited to the following Example. In the examples, all parts represent parts by mass.

-Synthesis of polyester resin 1 (pressure plastic resin)-
In a reaction vessel equipped with a condenser, a stirrer and a nitrogen inlet tube, 229 parts of bisphenol A ethylene oxide 2-mole adduct, 529 parts of bisphenol A propylene oxide 3-mole adduct, 208 parts terephthalic acid, 46 parts adipic acid and dibutyl 2 parts of tin oxide was added and reacted at 230 ° C. for 8 hours at normal pressure. Further, after 5 hours of reaction at a reduced pressure of 10 to 15 mmHg, 44 parts of trimellitic anhydride was put in a 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 6700, Tg of 43 ° C., an acid value of 25, and a slope of change in glass transition temperature with respect to pressure was −10 ° C./MPa. In addition, the C-80 high-pressure calorimeter apparatus made from SETARAM was used for the measurement of glass transition temperature and inclination. For 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 temperature rising rate was 0.5 ° C./min, the temperature was raised to 200 ° C., and the glass transition temperature was measured.

-Polylactic acid resin-
Polylactic acid resin Viro Ecole (registered trademark) BE-400 manufactured by Toyobo Co., Ltd. was used. The slope of the change in glass transition temperature with respect to the pressure of [polylactic acid resin] measured by the same method as described above was −20 ° C./MPa.

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

  On the other hand, in the same manner as above, 570 parts of bisphenol A ethylene oxide 2-mole adduct and 217 parts of terephthalic acid were reacted at 230 ° C. for 6 hours at normal pressure to obtain unmodified [polyester resin 2-2]. The obtained [Polyester resin 2-2] had a number average molecular weight of 2400, a hydroxyl value of 51, and an oxidation of 5. 200 parts of the obtained [urethane-modified polyester resin 2-1] and 800 parts of [polyester resin 2-2] were dissolved and mixed in 2000 parts of ethyl acetate to obtain a resin solution, and then a part was dried under reduced pressure Then, the resin content was isolated to obtain [Polyester Resin 2]. The slope of the change in glass transition temperature with respect to the pressure of [Polyester resin 2] measured by the same method as described above was −3 ° C./MPa.

-Synthesis of polyester resin 3 (pressure plastic resin)-
-Synthesis of crystalline polyester-
A 5-liter four-necked flask equipped with a nitrogen introduction tube, a dehydration tube, a stirrer and a thermocouple was added to 25 mol of 1,4-butanediol, 23.75 mol of fumaric acid, 1.65 mol of trimellitic anhydride, hydroquinone 5 .3 g was added and reacted at 160 ° C. for 5 hours, then heated to 200 ° C. and reacted for 1 hour. Furthermore, it was reacted at 8.3 KPa for 1 hour to obtain [Polyester resin 3]. The obtained [Polyester resin 3] had a melting point of 119 ° C., Mn710, Mw2100, an acid value of 24, and a hydroxyl value of 28. The slope of the change in the glass transition temperature with respect to the pressure of [Polyester resin 3] measured by the same method as described above was −5 ° C./MPa.

-Synthesis of polyester resin 4 (pressure plastic resin)-
In a reaction vessel equipped with a cooling pipe, a stirrer and a nitrogen introducing pipe, 283 parts by mass of sebacic acid, 215 parts by mass of 1,6-hexanediol and 1 part by mass of titanium dihydroxybis (triethanolaminate) as a condensation catalyst are placed. The reaction was carried out for 8 hours at 180 ° C. while distilling off the produced water under a nitrogen stream. Next, while gradually raising the temperature to 220 ° C., the reaction was carried out for 4 hours while distilling off the water and 1,6-hexanediol produced under a nitrogen stream, and the Mw was about 17 under a reduced pressure of 5 mmHg to 20 mmHg. The reaction was continued until it reached 1,000, and [Polyester resin 4] (crystalline polyester resin) having a melting point of 63 ° C. was obtained. The slope of the change in glass transition temperature with respect to the pressure of [Polyester resin 4] measured by the same method as described above was −12 ° C./MPa.

-Synthesis of polyurethane resin 1 (pressure plastic resin)-
In a reaction vessel equipped with a cooling pipe, a stirrer and a nitrogen introducing pipe, 283 parts by mass of sebacic acid, 215 parts by mass of 1,6-hexanediol and 1 part by mass of titanium dihydroxybis (triethanolaminate) as a condensation catalyst are placed. The reaction was carried out for 8 hours at 180 ° C. while distilling off the produced water under a nitrogen stream. Next, while gradually raising the temperature to 220 ° C., the reaction was carried out for 4 hours while distilling off the water and 1,6-hexanediol produced under a nitrogen stream, and the Mw was about 6 under a reduced pressure of 5 mmHg to 20 mmHg. The reaction was carried out until reaching 1,000. 249 parts by mass of the obtained crystalline resin was transferred into a reaction vessel equipped with a cooling tube, a stirrer and a nitrogen introduction tube, 250 parts by mass of ethyl acetate and 9 parts by mass of hexamethylene diisocyanate (HDI) were added, For 5 hours at 80 ° C. Next, ethyl acetate was distilled off under reduced pressure to obtain [Polyurethane Resin 1] (crystalline polyurethane resin) having an Mw of approximately 20,000 and a melting point of 65 ° C. The slope of the change in the glass transition temperature with respect to the pressure of [Polyurethane resin 1] measured by the same method as described above was −15 ° C./MPa.

-Polyphenylene sulfide resin-
Polyphenylene sulfide resin Torelina (registered trademark) 3030 manufactured by Toray Industries, Inc. was used. The slope of the change in glass transition temperature with respect to the pressure of [polyphenylene sulfide resin] measured by the same method as described above was −1 ° C./MPa.

Example 1
In Example 1, toner was manufactured using the particle manufacturing apparatus 2 of FIG. In Example 1, a carbon dioxide (carbon dioxide) cylinder was used as the cylinder 11. [Polyester resin 1] was put into the cell 24 of the particle production apparatus 2 shown in FIG. 5 and plasticized by heating to 160 ° C. The pump 12a was operated, the valve 13a was opened, and carbon dioxide was introduced as a first compressive fluid at 160 ° C. and 2 MPa. Further, the pump 12b was operated, the valve 13b was opened, and the plasticized [polyester resin 1] kneaded material and the first compressive fluid were mixed by the mixing device 17. The viscosity of the melt obtained by the mixing device 17 was 450 mPa · s. For measurement of the viscosity of the melt, a vibration viscometer (XL7) manufactured by Hydramotion was used. In this case, a sample and a compressive fluid (carbon dioxide) were put into a high-pressure cell, and the viscosity was measured under the conditions of 160 ° C. and 2 MPa. In this state, the valve 13c was opened, the pumps 12a and 12b were operated, and the melt was injected from the nozzle 32 having a hole diameter of 100 μm. The injected melt was made into particles and then solidified to obtain [Resin Particles 1]. The obtained [Resin particles 1] had a volume average particle diameter (Dv) of 72.6 μm, a number average particle diameter (Dn) of 9.3 μm, and Dv / Dn of 7.81. The volume average particle diameter and the ratio between the volume average particle diameter and the number average particle diameter (volume average particle diameter / number average particle diameter) are measured using a particle size measuring device “Coulter Counter TAII” manufactured by Coulter Electronics. It was measured.

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

-Example 5
(raw materials)
Polyester resin 1 95 parts Colorant (copper phthalocyanine blue) 5 parts Paraffin wax (melting point 79 ° C) 5 parts The raw materials of the toner were mixed with a mixer, melted and kneaded with a two-roll mill, and the kneaded product was rolled and cooled. This kneaded material was put into the cell 24 of the particle production apparatus 2 shown in FIG. Thereafter, the processing temperature, the processing pressure, and the nozzle diameter were changed to the values shown in Table 1, and the same operation as in Example 1 was performed to obtain [Toner 5]. Table 1 shows the melt viscosity, volume average particle diameter (Dv), number average particle diameter (Dn), and Dv / Dn measured in the same manner as in Example 1.

-Example 6
In Example 6, toner was manufactured using the particle manufacturing apparatus 3 of FIG. In Example 6, a carbon dioxide (carbon dioxide) cylinder was used as the cylinder 11. Further, a nitrogen cylinder was used as the cylinder 21.

  The same toner raw materials as in Example 5 were mixed with a mixer, melted and kneaded with a two-roll mill, and the kneaded product was rolled and cooled. This kneaded material was put into the cell 24 of the particle production apparatus 3 shown in FIG. 6 and heated to 130 ° C. to be plasticized. The pump 12a was operated, the valve 13a was opened, and carbon dioxide was introduced as a first compressive fluid at 130 ° C. and 65 MPa. Moreover, the pump 12b was operated, the valve 13b was opened, and the plasticized kneaded material and the first compressive fluid were mixed by the mixing device 17. Next, the valve 23 was opened, and supercritical nitrogen as the second compressive fluid was injected from the nozzle 32 so as to maintain 65 MPa and 135 ° C. using the pump 22 and the heater 26. In this state, the valve 13c was opened, and the melt was sprayed from the nozzle 32 while supplying the second compressive fluid to the melt obtained by the contact between the kneaded material and the first compressive fluid. At this time, by adjusting the pump 12a, the pump 12b, and the back pressure valve 14a, the melt passing through the mixing device 17 was maintained at a constant temperature of 130 ° C. and a pressure of 65 MPa. The sprayed melt was granulated and then solidified to obtain [Toner 6]. Table 1 shows the melt viscosity, number average particle diameter (Dn), and Dv / Dn measured in the same manner as in Example 1.

-Example 7-
[Toner] was operated in the same manner as in Example 5 except that [polyester resin 1] of the toner raw material was changed to [polylactic acid resin] and the processing temperature, processing pressure, and nozzle diameter were changed to the values shown in Table 1. 7] was obtained. Table 1 shows the melt viscosity, volume average particle diameter (Dv), number average particle diameter (Dn), and Dv / Dn measured in the same manner as in Example 1.

-Example 8-
[Polyester resin 1] was changed to [Polyester resin 3], and the treatment temperature, treatment pressure, and nozzle diameter were changed to the values shown in Table 1, and the same operation as in Example 1 was carried out to [Resin particles 8]. Got. Table 1 shows the melt viscosity, volume average particle diameter (Dv), number average particle diameter (Dn), and Dv / Dn measured in the same manner as in Example 1.

-Example 9-
[Toner 9] was obtained in the same manner as in Example 5 except that [Polyester resin 1] was changed to [Polyester resin 4] and the processing temperature and processing pressure were changed to the values shown in Table 2. Table 2 shows the melt viscosity, volume average particle diameter (Dv), number average particle diameter (Dn), and Dv / Dn measured in the same manner as in Example 1.

-Example 10-
[Toner 10] was obtained in the same manner as in Example 5, except that [Polyester resin 1] was changed to [Polyurethane resin 1] and the processing temperature and processing pressure were changed to the values shown in Table 2. Table 2 shows the melt viscosity, volume average particle diameter (Dv), number average particle diameter (Dn), and Dv / Dn measured in the same manner as in Example 1.

  The average of the maximum ferret diameter of each toner cavity was determined as follows. The cross section of the particles was observed with an electron microscope or the like, a cross-sectional photograph was taken, the cross-sectional photograph was processed using image processing software (ImageJ), and binarized to identify the cavity. Thirty points were selected in descending order of the diameter of the identified maximum ferret diameter of the cavity, and the average was taken as the average of the maximum ferret diameter of the cavity.

-Comparative Example 1-
(Toner raw material)
50 g of polyester resin 2
Colorant (copper phthalocyanine blue) 2.5 parts Trimethylolpropane tribenate (melting point 58 ° C.) 12.5 parts Resin dissolution that has a stirrer and a temperature measuring device and can be set up to a pressure of 30 MPa and a temperature of 290 ° C. The temperature of the tank was raised to 150 ° C., and then the toner raw material was charged and melted. Next, 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 pressure pump. At this time, the static mixer internal pressure was set to 8 MPa. Although the 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, the toner melt was not sufficiently plasticized and could not be granulated. It was.

-Comparative Example 2-
The same operation as in Example 1 was performed except that [Polyester Resin 1] was changed to [Polyphenylene Sulfide Resin 1] and the processing temperature, processing pressure, and nozzle diameter were changed to the values shown in Table 2. The melt was not sufficiently plasticized and could not be granulated.

  To 100 parts by mass of each [Toner 5 to 7, 9, 10] thus obtained, 0.7 part by mass of hydrophobic silica and 0.3 part by mass of hydrophobized titanium oxide were added, and the mixture was added using a Henschel mixer. The mixture was mixed for 5 minutes at a peripheral speed of 8 m / s. The powder after mixing was passed through a mesh having an opening of 100 μm to remove coarse powder. Next, a type of tumbler in which the container rolls and stirs 5% by mass of the toner subjected to the external additive treatment and 95% by mass of a copper-zinc ferrite carrier having an average particle diameter of 40 μm coated with a silicone resin. Using a mixer, the mixture was uniformly mixed and charged to prepare a two-component [developer 5-7, 9, 10]. The toners used in [Developers 5 to 7, 9, and 10] sequentially correspond to the above [Toners 5 to 7, 9, and 10].

  Further, 0.7 parts by mass of hydrophobic silica and 0.3 parts by mass of hydrophobized titanium oxide were added to 100 parts by mass of each [Toner 5 to 7, 9, 10], and the peripheral speed was 8 m / s using a Henschel mixer. The mixture was mixed for 5 minutes under the above conditions to prepare a one-component [developer 15-17, 19, 20]. The toners used in [Developers 15 to 17, 19, and 20] sequentially correspond to the above [Toners 5 to 7, 9, and 10].

  For each developer obtained, an image forming apparatus (IPSio Color 8100 manufactured by Ricoh Co., Ltd. was used for the evaluation of the two-component developer, and Imagio Neo C200 manufactured by Ricoh Co., Ltd. was used for the evaluation of the one-component developer. The image was output and evaluated as follows. The results are shown in Tables 3 and 4.

<Image density>
After outputting a solid image at an adhesion amount of 0.3 ± 0.1 mg / cm2, which is a low adhesion amount on plain paper transfer paper (manufactured by Ricoh Co., Ltd., type 6200), the image density is measured by a densitometer X-Rite (X-Rite). ) And evaluated according to the following criteria.
〔Evaluation criteria〕
A: Image density of 1.4 or more O: 1.35 or more and less than 1.4 Δ: 1.3 or more and less than 1.35 ×: Less than 1.3 was evaluated as “x”.

<Toner scattering>
In an environment of a temperature of 40 ° C. and a humidity of 90% RH, an image forming apparatus (Ricoh Co., Ltd., IPSiO Color 8100) was remodeled to an oil-less fixing system and tuned to an evaluation machine. The toner contamination state in the copier after the% chart continuous 100,000 sheet output durability test was visually evaluated according to the following criteria.
〔Evaluation criteria〕
A: The toner is not observed at all and is in a good state.
○: Slight dirt is observed, and there is no problem.
Δ: Slightly dirty.
X: Very dirty and out of the allowable range.

<Transferability>
After the image area ratio 20% chart is transferred from the photoconductor to the paper, the transfer residual toner on the photoconductor immediately before the cleaning is transferred to a white paper with a scotch tape (manufactured by Sumitomo 3M Co., Ltd.), and is transferred to a Macbeth reflection densitometer RD514 type. Measured and evaluated according to the following criteria.
〔Evaluation criteria〕
A: The difference from the blank is less than 0.005.
(Circle): The difference with a blank is 0.005-0.010.
(Triangle | delta): The difference with a blank is 0.011-0.02.
X: The difference with a blank exceeds 0.02.

<Charging stability>
Using each toner, a continuous 100,000 sheet output durability test was conducted using a character image pattern with an image area ratio of 12%, and the change in the charge amount at that time was evaluated. A small amount of developer was collected from the sleeve, the change in charge amount was determined by the blow-off method, and evaluated according to the following criteria.
〔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: Change in charge amount exceeds 10 μc / g.

<Filming properties>
Filming on the developing roller after outputting 1000 sheets of band charts with image area ratios of 100%, 75%, and 50% and filming on the photoreceptor were observed and evaluated according to the following criteria.
〔Evaluation criteria〕
A: Filming does not occur at all.
○: The occurrence of filming can be confirmed slightly.
Δ: Filming occurs in streaks.
X: Filming has occurred on the entire surface.

<Cleanability>
The transfer residual toner on the photosensitive member that has passed the cleaning process after outputting 1,000 sheets of a 95% image area ratio chart is transferred to white paper with Scotch tape (manufactured by Sumitomo 3M Limited), and measured with a Macbeth reflection densitometer RD514 type. The evaluation was made according to the following criteria.
〔Evaluation criteria〕
A: The difference from the blank is less than 0.005.
(Circle): The difference with a blank is 0.005-0.010.
(Triangle | delta): The difference with a blank is 0.011-0.02.
X: The difference with a blank exceeds 0.02.

<Comprehensive evaluation>
The evaluation result of each evaluation item was 1 point, ○ was 0 point, Δ was −1 point, and × was −2 point, and the total evaluation was performed based on the total points.
〔Evaluation criteria〕
◎: Total score is 4 to 5 ○: Total score is 0 to 3 △: Total score is -3 to -1 -1 ×: Total score is -4 or less

DESCRIPTION OF SYMBOLS 1 Particle manufacturing apparatus 2 Particle manufacturing apparatus 11, 21 Cylinder 12a, 12b, 22 Pump 13a, 13b, 23 Valve 14 High pressure cell 16, 26 Heater 24 Cell 17, 31 Mixing apparatus 32 Nozzle 200 Image forming apparatus 210 Paper feed part 211 Supply Paper cassette 212 Paper feed roller 220 Transport unit 221 Roller 222 Timing roller 223 Paper discharge roller 224 Paper 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 electrostatic latent image forming means)
234 Developing device (an example of developing means)
235 Static eliminator 236 Cleaning device 237 Toner cartridge 240 Transfer section (an example of transfer means)
241 Driving roller 242 Driven roller 243 Intermediate transfer belt 244 Primary transfer roller 245 Secondary counter roller 246 Secondary transfer roller 250 Fixing section (an example of fixing means)
251 Heating roller 252 Pressure roller T Toner

Japanese Patent No. 2,676,685 Japanese Patent Laid-Open No. 10-20552 Japanese Patent No. 4113451

Claims (16)

A melting step of contacting the compressive fluid and the pressure plastic material to melt the pressure plastic material;
A granulation step of granulating the molten material obtained by melting the pressure plastic material,
The method for producing particles, wherein the melt has a viscosity of 500 mPa · s or less.   The method for producing particles according to claim 1, wherein the pressure plastic material is a resin having a carbonyl structure.   The method for producing particles according to claim 1, wherein the melt has a viscosity of 20 mPa · s or less.   The particle according to any one of claims 1 to 3, wherein a slope of a change in a glass transition temperature of the pressure plastic material with respect to a pressure applied to the pressure plastic material is -5 ° C / MPa or less. Manufacturing method.   The method for producing particles according to claim 4, wherein an inclination of a change in the glass transition temperature of the pressure plastic material with respect to the pressure applied to the pressure plastic material is −10 ° C./MPa or less.   The method for producing particles according to any one of claims 1 to 5, wherein, in the granulation step, the melt is sprayed while a compressive fluid is supplied to the melt. In the melting step, the compressive fluid and the pressure plastic material are continuously contacted,
The method for producing particles according to any one of claims 1 to 6, wherein in the granulation step, the melt is sprayed and continuously granulated.   The method for producing particles according to claim 7, wherein in the melting step, the compressive fluid and the pressure plastic material are continuously contacted without using a static mixer.   The method for producing particles according to claim 1, 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 compressive fluid contains carbon dioxide.   The method for producing particles according to any one of claims 1 to 10, wherein, in the melting step, the compressive fluid is brought into contact with the pressure plastic material heated and plasticized.   A particle produced by the method for producing a particle according to any one of claims 1 to 11, and substantially free of an organic solvent.   A toner produced by the method for producing particles according to any one of claims 1 to 11, wherein the pressure plastic material is a raw material of the toner and contains substantially no organic solvent.   A developer comprising the toner according to claim 13. An electrostatic latent image carrier;
An 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 13;
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:   Particles containing a pressure plastic material and having cavities having an average maximum ferret diameter of 10 nm or more and less than 500 nm.

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