JP2014167597A - Manufacturing method of toner, toner, developer, and manufacturing method of particle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of a toner having excellent chargeability and fixability.SOLUTION: A manufacturing method of a toner containing a binder resin including a pressure plastic material, and a mold release agent includes: a mixing step of continuously supplying and merging the pressure plastic material and the mold release agent to continuously form a mixture of those, and continuously supplying the resulting mixture to the subsequent step (melting step); the melting step of bringing a first compressive fluid into contact with the mixture to melt the mixture; and a granulating step of injecting a molten body obtained in the melting step to granulate the molten body.

Description

  The present invention relates to a toner manufacturing method, a toner, a developer, and a particle manufacturing method.

  As a method for fixing a toner image formed on an image support such as paper, a heat roller fixing method in which the image support is fixed by passing between a heating roller and a pressure roller is widely used. In order to prevent the offset phenomenon that the melted toner adheres to the heating roller, in recent years, a technique has been adopted in which a release agent such as wax is added to the toner so as to impart releasability to the toner itself.

  On the other hand, as a toner production method, a kneaded material obtained by melting and kneading a raw material containing additives such as a thermoplastic resin and a release agent is cooled and solidified, and then pulverized to form particles. It has been known. At this time, in Patent Document 1, in order to control the particle shape of the toner, a raw material containing a thermoplastic resin is kneaded and pulverized in an aqueous solvent in the presence of hydrophilic inorganic fine particles. A method for producing toner by removing the toner is disclosed.

  However, in the toner manufacturing method disclosed in Patent Document 1, it is difficult to control the particle size of the release agent particles dispersed in the thermoplastic resin. For this reason, the release agent of coarse particles may be mixed into the toner alone, and the chargeability and fixability of the toner may deteriorate.

  Therefore, an object of the present invention is to provide a method for producing a toner excellent in chargeability and fixability.

According to the present invention,
A method for producing a toner comprising a binder resin containing a pressure plastic material and a release agent,
A mixing step of continuously forming the mixture by continuously supplying and joining the pressure plastic material and the release agent, and continuously supplying to the next step (melting step);
A melting step of contacting the first compressive fluid and the mixture to melt the mixture;
A granulation step of spraying and granulating the melt obtained in the melting step;
A method for producing a toner having the above is provided.

  According to the present invention, it is possible to provide a method for producing a toner excellent in chargeability and fixability.

FIG. 1 is a schematic diagram for explaining an example of the toner of this embodiment. FIG. 2 is a diagram for explaining an example of the pressure plastic material in the present embodiment, and is a schematic diagram showing the relationship between the glass transition temperature and the pressure. FIG. 3 is an example of a phase diagram for explaining the state of a substance under a certain temperature and pressure condition. FIG. 4 is an example of a phase diagram for explaining the compressible fluid in the present embodiment. FIG. 5 is a schematic view of a particle manufacturing apparatus according to an embodiment of the present invention. FIG. 6 is a schematic view of a particle manufacturing apparatus according to another embodiment of the present invention. FIG. 7 is a schematic view showing an image forming apparatus according to the present embodiment.

  Hereinafter, the present invention will be described in more detail with reference to the drawings. In the present embodiment, a novel toner manufacturing method will be described as an example, but the toner manufacturing method of the present embodiment can also be applied to a method for manufacturing particles other than toner.

  Note that. In this embodiment, “melting” means that a material such as a pressure plastic material swells when it comes into contact with a compressive fluid, and is plasticized, semi-liquefied, liquefied, and a pressure plastic material. It refers to plasticizing, semi-liquefying, or liquefying by heating a material such as. Further, in this embodiment, the “raw material” refers to a material containing particle constituents for producing particles (toner in this embodiment).

  First, an outline of toner manufactured by the toner manufacturing method of the present embodiment will be described.

  The toner manufactured by the toner manufacturing method of the present embodiment (that is, the toner of the present embodiment) has a binder resin containing a pressure plastic material and a release agent, and is a “particulate” mold release. Contains multiple agents.

  Here, the “particulate” release agent means a release agent present in a substantially spherical shape in the toner, and the aspect ratio of the release agent cross-sectional shape when the cross section of the toner is observed with an electron microscope ( It means a substantially circular mold release agent having a major axis / minor axis) of 1 to 2. The toner according to the exemplary embodiment includes only such a particulate release agent. For example, the release agent having a cross section of the toner has a so-called needle shape or a shape that is not clearly circular due to unevenness. Is not included.

  To calculate the aspect ratio of the release agent, first, observe the cross section of the toner with an electron microscope, take a cross-sectional photograph, process the cross-sectional photograph with image processing software, and binarize it to identify the release agent part. To do. Then, the aspect ratio of the identified release agent is calculated as a value obtained by dividing the major axis of the release agent by the minor axis of the release agent.

  FIG. 1 is a schematic diagram for explaining an example of the toner of the present embodiment. Specifically, FIG. 1A is a cross-sectional SEM image of the toner of this embodiment, and FIG. 1B is a cross-sectional TEM image of a conventional toner.

  As is clear from a comparison between FIG. 1A and FIG. 1B, the toner of this embodiment contains a plurality of “particulate” release agents. In this case, although not limited, it is preferable that the toner of the exemplary embodiment forms a sea-island structure by a pressure plastic material that forms a sea phase and particles of a release agent that forms an island phase. Moreover, it is preferable that the particle | grains of a mold release agent have a substantially spherical shape, and the average of the maximum ferret diameter of the particle | grains of a mold release agent is 300 nm or more and less than 1.5 micrometers.

  The toner of this embodiment contains a plurality of “particulate” release agents, the release agent particles have a substantially spherical shape, and the average maximum ferret diameter of the release agent particles is 300 nm or more and less than 1.5 μm. By doing so, it is possible to efficiently prevent toner spent due to the needle-like release agent particles generated in the conventional toner protruding from the binder resin. The maximum ferret diameter refers to a diameter at which the interval between parallel lines is the largest when the object is sandwiched between parallel lines.

  The binder resin is not particularly limited as long as it contains a crystalline resin in an amount of 50% by mass or more based on the binder resin, and can be appropriately selected depending on the purpose. Further, the binder resin may be a binder resin in which a crystalline resin and an amorphous resin are used in combination, but it is preferable that the main component of the binder resin is substantially a crystalline resin.

  The content of the crystalline resin with respect to the binder resin is not particularly limited as long as it is 50% by mass or more, and can be appropriately selected according to the purpose. However, it is preferably 65% by mass or more, more preferably 80% by mass or more, and 95% by mass from the viewpoint of maximizing the compatibility of excellent low-temperature fixability and heat-resistant storage stability due to the crystalline resin. The above is more preferable. When the content of the crystalline resin is less than 50% by mass, the heat steepness of the binder resin cannot be expressed on the viscoelastic properties of the toner, and it may be difficult to achieve both low-temperature fixability and heat-resistant storage stability.

  The “crystalline” resin in the present embodiment is the ratio between the softening temperature measured by the Kaohashi flow tester and the maximum peak temperature of the heat of fusion measured by a differential scanning calorimeter (DSC) (softening temperature). / Maximum peak temperature of heat of fusion) is within the range of 0.8 to 1.55. By being a parameter within this range, it has the property of being sharply softened by heat.

  An “amorphous” resin refers to a resin having a ratio between the softening temperature and the maximum peak temperature of heat of fusion (softening temperature / maximum peak temperature of heat of fusion) of greater than 1.55. By being a parameter within this range, it has the property of being softened gently by heat.

  The softening temperature of the resin and toner can be measured using a Koka flow tester (for example, CFT-500D (manufactured by Shimadzu Corporation)). As a measuring method, first, 1 g of resin as a sample is heated at a heating rate of 6 ° C./min, a load of 1.96 MPa is applied by a plunger, extruded from a nozzle having a diameter of 1 mm and a length of 1 mm, and a flow against temperature The plunger drop amount of the tester was plotted, and the temperature at which half the sample flowed out was defined as the softening temperature.

  The maximum peak temperature of the heat of fusion of the resin and toner can be measured using a differential scanning calorimeter (DSC) (for example, TA-60WS and DSC-60 (manufactured by Shimadzu Corporation)). As a measurement method, first, a measurement sample was melted at 130 ° C. as a pretreatment, and then the temperature was lowered from 130 ° C. to 70 ° C. at a rate of 1.0 ° C./minute, and then from 70 ° C. to 10 ° C., 0.5 ° C. Decrease the temperature at a rate of / min. Here, by DSC, the temperature is increased at a rate of temperature increase of 20 ° C./min to measure the endothermic change, and a graph of “endothermic amount” and “temperature” is drawn. The endothermic peak temperature at 100 ° C. is defined as “Ta *”. When there are a plurality of endothermic peaks, the temperature of the peak with the largest endothermic amount is Ta *. Thereafter, the sample is stored at (Ta * −10) ° C. for 6 hours, and further stored at (Ta * −15) ° C. for 6 hours. Next, the sample was cooled to 0 ° C. by DSC at a temperature decrease rate of 10 ° C./min, and then the temperature was increased at a temperature increase rate of 20 ° C./min to measure the endothermic change. The temperature corresponding to the maximum peak of the calorific value was taken as the maximum peak temperature of the heat of fusion.

  The pressure plastic material is preferably a crystalline resin having pressure plasticity. When the pressure plastic material is a crystalline resin, a toner can be obtained by melting the crystalline resin with a compressive fluid and performing spray granulation by a method described later without using an organic solvent.

  In the toner manufacturing method of the present embodiment, the colorant can be uniformly dispersed. In the conventional toner manufacturing method mainly comprising a crystalline resin, it has been difficult to uniformly disperse the colorant in the toner. However, in the toner manufacturing method of this embodiment, the colorant can be uniformly dispersed.

  Next, the raw material of the toner of this embodiment will be described.

[Pressure plastic material]
The pressure plastic material, which is one of the raw materials in the toner manufacturing method of the present invention, will be described. In FIG. 2, it is a figure for demonstrating the example of the pressure plastic material in this embodiment, Comprising: The schematic which shows the relationship between a glass transition temperature and a pressure is shown. In FIG. 2, the vertical axis represents the glass transition temperature and the horizontal axis represents the pressure.

  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 refers to the material to be converted. Therefore, the pressure plastic material is plasticized at a temperature lower than the glass transition temperature of the pressure plastic material at atmospheric pressure, for example, by contacting with the compressive fluid described later.

  FIG. 2 shows the relationship between the glass transition temperature and pressure of polystyrene in the presence of carbon dioxide as an example of a pressure plastic material. As is clear from FIG. 2, the glass transition temperature and pressure of polystyrene have a correlation, and the inclination is negative on the axis of FIG. A pressure plastic material usually has a negative slope of change in glass transition temperature with respect to applied pressure, such as polystyrene. This inclination varies depending on the type, composition, molecular weight, and the like of the pressure plastic material.

  As an example, the inclination described above is polystyrene; −9 ° C./MPa, styrene-acrylic resin; −9 ° C./MPa, amorphous polyester resin; −8 ° C./MPa, crystalline polyester; MPa, polyol resin: −8 ° C./MPa, urethane resin: −7 ° C./MPa, polyarylate resin: −11 ° C./MPa, polycarbonate resin: −10 ° C./MPa.

  As an example of the measuring method of inclination, it can obtain | require by measuring a glass transition temperature by changing a pressure using the C-80 high pressure calorimeter apparatus made from SETARAM. In this embodiment, a sample was set in a high-pressure measurement cell, the inside of the cell was replaced with carbon dioxide, and then the glass transition temperature was measured by pressurizing to a predetermined pressure. The slope in the present invention was determined based on the amount of change in the glass transition temperature when the pressure was 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 of the pressure plastic material used in the present embodiment is not particularly limited, but is preferably −1 ° C./MPa or less, and more preferably −5 ° C./MPa or less. Preferably, it is −10 ° C./MPa or less. When the slope of the change in the glass transition temperature with respect to the pressure is larger than −1 ° C./MPa, the plasticization becomes insufficient when the pressure is applied without applying heat, and it becomes difficult to reduce the viscosity of the melt described later. Granulation may be difficult.

  The pressure plastic material used in the present embodiment is preferably a material having a viscosity of 500 mPa · s or less when a pressure of 30 MPa or less is applied. In this case, the pressure plastic material may be heated to a temperature less than the melting point at normal pressure so that the viscosity becomes 500 mPa · s or less under the condition of 30 MPa or less.

  The pressure plastic material is not particularly limited. For example, polyester resin, vinyl resin, urethane resin, polyol resin, polyamide resin, epoxy resin, rosin, modified rosin, terbene resin, phenol resin, aliphatic or alicyclic carbonization. Examples thereof include hydrogen resin, aromatic petroleum resin, chlorinated paraffin, paraffin wax, polyethylene, and polypropylene. These may be used alone or in combination of two or more.

  The polyester resin is not particularly limited, and examples thereof include modified polyester, unmodified polyester, amorphous polyester, crystalline polyester, and polylactic acid resin.

  The polylactic acid resin is not particularly limited, and examples thereof include L-form, D-form or racemic polylactic acid resin, stereocomplex polylactic acid resin, and polylactic acid block copolymer.

  As the polyol resin, a polyether polyol resin having an epoxy skeleton can be used, and (i) an epoxy resin, (ii) an alkylene oxide adduct of dihydric phenol or a glycidyl ether thereof, (iii) a reaction with an epoxy group A polyol resin or the like obtained by reacting a compound having active hydrogen to be used can be suitably used.

  Although there is no restriction | limiting in particular as a vinyl resin, For example, styrene, such as a 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 Polymer, styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, styrene-butyl methacrylate copolymer, styrene-α-chloromethyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene -Vinylmethylketone copolymer, styrene Styrene copolymers such as butadiene copolymer, styrene-isoprene copolymer, styrene-acrylonitrile-indene copolymer, styrene-maleic acid copolymer, styrene-maleic acid ester copolymer; polymethyl methacrylate, poly Simple substances such as butyl 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-vinyl pyridine, butadiene, etc. Examples thereof include a polymer of a monomer, a copolymer composed of two or more of these monomers, or a mixture thereof.

  There is no restriction | limiting in particular as a urethane resin, According to the objective, it can select suitably and can be used.

  In the present embodiment, the pressure plastic material preferably includes a resin having a carbonyl group. The carbonyl group has a structure in which an oxygen atom having high electronegativity is bonded to a carbon atom by a π bond. The π-bonded electrons are strongly attracted to the oxygen atom, the oxygen atom is negatively polarized, and the carbon atom is positively polarized. Therefore, a resin having a carbonyl group is highly reactive. In addition, when carbon dioxide is used as a compressive fluid to be described later, the carbonyl structure has a structure similar to the molecular structure of carbon dioxide, so that it is assumed that the affinity between carbon dioxide and the pressure plastic material is increased. Therefore, it is considered that the plasticization of the pressure plastic material by the compressive fluid is facilitated.

(Crystalline resin)
As described above, the binder resin preferably includes a crystalline resin. The crystalline resin is not particularly limited as long as it has crystallinity, and can be appropriately selected according to the purpose. For example, polyester resin, polyurethane resin, polyurea resin, polyamide resin, polyether resin, vinyl Examples thereof include resins and modified crystalline resins. These may be used alone or in combination of two or more. Among these, it is preferable to use a polyester resin, a polyurethane resin, a polyurea resin, a polyamide resin, or a polyether resin, and it is preferable to use a resin having at least one of a urethane skeleton and a urea skeleton. It is more preferable to use a type polyester resin and a composite resin containing the linear type polyester resin.

  Here, preferable examples of the resin having at least one of a urethane skeleton and a urea skeleton include the polyurethane resin, the polyurea resin, the urethane-modified polyester resin, and the urea-modified polyester resin. The urethane-modified polyester resin is a resin obtained by reacting a polyester resin having an isocyanate group at a terminal with a polyol. The urea-modified polyester resin is a resin obtained by reacting a polyester resin having an isocyanate group at a terminal with amines.

  The maximum peak temperature of the heat of fusion of the crystalline resin is preferably in the range of 45 ° C. to 70 ° C., and in the range of 53 ° C. to 65 ° C., from the viewpoint of achieving both low temperature fixability and heat resistant storage stability. It is more preferable that it is in the range of 58 ° C to 62 ° C. When the maximum peak temperature is lower than 45 ° C., the low-temperature fixability is improved but the heat-resistant storage stability may be deteriorated. When the maximum peak temperature is higher than 70 ° C., the heat-resistant storage stability is improved but the low-temperature fixability may be deteriorated. .

  The ratio of the softening temperature of the crystalline resin to the maximum peak temperature of the heat of fusion (softening temperature / maximum peak temperature of the heat of fusion) is in the range of 0.8 to 1.55 as described above. It is preferably in the range of 1.25, more preferably in the range of 0.9 to 1.2, and still more preferably in the range of 0.9 to 1.19. Generally, the smaller the ratio, the more preferable the resin is because it has a property of softening sharply, and both low-temperature fixability and heat-resistant storage stability can be achieved.

In the viscoelastic properties of the crystalline resin, the storage elastic modulus G ′ at (maximum peak temperature of heat of fusion) + 20 ° C. is preferably 5.0 × 10 ⁶ Pa · s or less, 1.0 × 10 ¹ Pa · s to More preferably, it is in the range of 5.0 × 10 ⁵ Pa · s, and still more preferably in the range of 1.0 × 10 ¹ Pa · s to 1.0 × 10 ⁴ Pa · s. Further, the loss elastic modulus G ″ at (the maximum peak temperature of heat of fusion) + 20 ° C. is preferably 5.0 × 10 ⁶ Pa · s or less, and 1.0 × 10 ¹ Pa · s to 5.0 × 10 ^5. More preferably, it is in the range of Pa · s, and still more preferably in the range of 1.0 × 10 ¹ Pa · s to 1.0 × 10 ⁴ Pa · s. In consideration of the increase in G ′ and G ″ by dispersing the colorant and the layered inorganic mineral in the binder resin in the viscoelastic characteristics of the toner of the present invention, (maximum peak temperature of heat of fusion) +20 The values of G ′ and G ″ at ° C. are preferably in the range of 1.0 × 10 ³ Pa · s to 5.0 × 10 ⁶ Pa · s.

  The viscoelastic properties of the crystalline resin can be adjusted by adjusting the ratio between the crystalline monomer and the amorphous monomer constituting the resin, the molecular weight of the resin, and the like. For example, generally, when the ratio of the crystalline monomer is increased, the value of G ′ (Ta + 20) is decreased.

  The dynamic viscoelastic characteristic values (storage elastic modulus G ′, loss elastic modulus G ″) of the resin and toner are measured using a dynamic viscoelasticity measuring apparatus (for example, ARES (manufactured by TA Instruments)). In this case, for example, measurement is performed under the condition of a frequency of 1 Hz First, a sample is formed into a pellet having a diameter of 8 mm and a thickness of 1 mm to 2 mm, and fixed to a parallel plate having a diameter of 8 mm, and then stabilized at 40 ° C. The temperature is increased to 200 ° C. at a rate of temperature increase of 2.0 ° C./min at a frequency of 1 Hz (6.28 rad / s) and a strain amount of 0.1% (strain amount control mode).

  The weight average molecular weight (Mw) of the crystalline resin is preferably in the range of 2,000 to 100,000 and more preferably in the range of 5,000 to 60,000 from the viewpoint of fixability. Preferably, it exists in the range of 8,000-30,000. When the weight average molecular weight is less than 2,000, the hot offset resistance tends to deteriorate, and when it exceeds 100,000, the low-temperature fixability tends to deteriorate.

  In this embodiment, the weight average molecular weight (Mw) of the resin can be measured using a gel permeation chromatography (GPC) measuring device (for example, GPC-8220 GPC (manufactured by Tosoh Corporation)). As the column, TSKgel SuperHZM-H 15 cm triplet (manufactured by Tosoh Corporation) was used. The resin to be measured was made into a 0.15 mass% solution in tetrahydrofuran (THF) (containing a stabilizer, manufactured by Wako Pure Chemical Industries), filtered through a 0.2 μm filter, and the filtrate was used as a sample. 100 μl of the THF sample solution was injected into the measuring apparatus, and measurement was performed at a flow rate of 0.35 ml / min in an environment at a temperature of 40 ° C. In measuring the molecular weight of the sample, it was calculated from the relationship between the logarithmic value of the calibration curve prepared from several types of monodisperse polystyrene standard samples and the number of counts. Standard polystyrene samples include Showdex STANDARD Std. No S-7300, S-210, S-390, S-875, S-1980, S-10.9, S-629, S-3.0, S-0.580, and toluene were used. An RI (refractive index) detector was used as the detector.

[Release agent]
Although there is no restriction | limiting in particular as a mold release agent, 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 alone or in combination of two or more.

  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.

  The melting point of the release agent described above is not particularly limited, but is preferably, for example, 40 ° C. or higher and 160 ° C. or lower, more preferably 50 ° C. or higher and 120 ° C. or lower, and 60 ° C. or higher and 90 ° C. or lower. Further preferred. When the melting point of the release agent is less than 40 ° C., the heat resistant storage stability of the toner may be lowered. On the other hand, when the melting point of the release agent exceeds 160 ° C., a cold offset (low temperature offset) may easily occur during fixing at a low temperature. In addition, paper wrapping around the fixing machine may occur. Note that the cold offset is, for example, in the heat roller fixing method, because the toner is not sufficiently melted near the interface between the toner and the fixing medium (for example, paper), and a part of the toner image is removed by electrostatic adsorption. It is to be.

  The addition amount of the release agent is preferably 1 part by mass or more and 20 parts by mass or less, more preferably 3 parts by mass or more and 15 parts by mass or less with respect to 100 parts by mass of the toner. 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. On the other hand, when the addition amount of the release agent exceeds 20 parts by mass, the heat resistant storage stability of the toner may be lowered.

  In the toner manufacturing method of the present embodiment, the release agent and the pressure plastic material are separately melted in advance, and then continuously supplied to the mixing device so that each has a predetermined mass ratio. The release agent and the pressure plastic material that have joined in the mixing apparatus are immediately mixed to form a mixture. At this time, it is preferable to continuously supply the obtained mixture to the next step. In general, the release agent and the pressure plastic material have different specific gravities. Therefore, when these are melted simultaneously in the same container, the release agent and the pressure plastic material may be two-phase separated, and the obtained toner may not have a desired amount of the release agent.

[Other ingredients]
Other components may be added to the toner of the exemplary embodiment as necessary. Specifically, materials such as a colorant, a surfactant, a dispersant, a charge control agent, and a crystalline polyester may be added.

(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.

  Specific examples of the colorant include, for example, carbon black, nigrosine dye, iron black, naphthol yellow S, Hansa yellow (10G, 5G, G), cadmium yellow, yellow iron oxide, ocher, yellow lead, titanium. Yellow, 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 Rake, Quinoline Yellow Lake, Anthrazan Yellow BGL, Isoindolinone Yellow, Bengala, Red Dan, Lead Zhu, Cadmium Red, Cadmium Mercury Red, Antimon Zhu, Permanent Red 4R, Para Red, Faise Red, Parachlor Orthonitroaniline red, lyso Rufast Scarlet G, Brilliant Fast Scarlet, Brilliant Carmine BS, 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, black Muver Million, 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, bitumen, anthraquinone blue, fast violet B, methyl violet lake, cobalt purple, manganese purple, dioxane violet, anthraquinone violet, chrome green, zinc green, chromium oxide, pyridian, emerald green, pigment green B , Naphthol Green B, Green Gold, Acid Green Lake, Malachite Green Lake, Phthalocyanine Green, Blue Nthraquinone green, titanium oxide, zinc white, lithobon, and the like can be mentioned.

  Specific 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 may also be used. Examples of 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 YEllo 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. , Blue A-2R, and the like.

  There is no restriction | limiting in particular as addition amount of a coloring agent, Although it can select suitably according to desired coloring degree, It is preferable that it is 1 to 50 mass parts with respect to 100 mass parts of pressure plastic materials. In addition, the colorant mentioned above may be used individually by 1 type, and may be used in combination of 2 or more types.

(Surfactant)
The toner according to the exemplary embodiment preferably includes a surfactant as a raw material. The surfactant in the present embodiment means that having a portion having affinity for a compressive fluid described later and a portion having affinity for toner in the same molecule.

  Although there is no restriction | limiting in particular as surfactant, When the 1st compressive fluid is a carbon dioxide, fluorine-type surfactant, silicone type surfactant; Bulkiness, such as a carbonyl group, a hydrocarbon group, a propylene oxide group, etc. It is preferable to use a compound having a parent carbon dioxide group such as a compound having a high functional group. Among the surfactants described above, it is preferable to use a fluorine-based surfactant, a silicone-based surfactant, a carbonyl group-containing compound, or a polyethylene glycol (PEG) group-containing compound. These surfactants may be in the form of oligomers or polymers.

  As a fluorine-type surfactant in this embodiment, the compound which has a C1-C30 perfluoroalkyl group can be used preferably. Among these, it is preferable to use a high molecular weight fluorine-based surfactant from the viewpoints of surface activity, charging performance and durability 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 the formula (1-2) each independently represents 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). , N-butyl group, sec-butyl group, tert-butyl group, etc.).

R ₂ in the formula (1-1) refers to an alkylene group (for example, a methylene group, an ethylene group, a propylene group, an isoprene group, a 2-hydroxypropylene group, a butylene group, a 2-hydroxybutylene group, 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 the above-mentioned, it is possible to use a fluorosurfactant 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. preferable.

  In addition, an oligomer or a polymer is formed by combining a plurality of structural units of the formulas (1-1) and (1-2). In this case, a homopolymer, a block copolymer, a random copolymer, or the like may be formed according to the affinity with the toner. Each end of the oligomer or polymer is not particularly limited, but is usually a hydrogen atom.

  The silicone surfactant of this embodiment 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, it is preferable to use a compound containing a polydimethylsiloxane (PDMS) group represented by the formula (2). The silicone-based surfactant of the present embodiment may be in the form of a homopolymer, a block copolymer, a random copolymer, etc. depending on the affinity with the toner.

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

  Although there is no restriction | limiting in particular as a carbonyl group containing compound of this embodiment, For example, aliphatic polyester, polyacrylate, an acrylic resin, etc. are mentioned.

  Although there is no restriction | limiting in particular as a PEG group containing compound of this embodiment, For example, PEG group containing polyacrylate, polyethyleneglycol resin, etc. are mentioned.

  The surfactant of this embodiment described above is obtained by polymerizing vinyl monomers such as Rf group-containing vinyl monomers, PDMS group-containing vinyl monomers, PEG group-containing vinyl monomers, or these vinyl monomers and other vinyl monomers. Can be produced by copolymerization. Examples of vinyl monomers include styrene monomers, acrylate monomers, and methacrylate monomers. In addition, you may use what is marketed for these vinyl monomers.

  Further, as the surfactant, Rf group, PDMS group or PEG group may be the main chain of the oligomer or polymer, and COOH group, OH group, amino group, pyrrolidone skeleton, etc. introduced into the side chain may be used. good.

  The fluorine group-containing surfactant of this embodiment is synthesized by polymerizing a fluorinated vinyl monomer in a fluorinated solvent such as HCFC225. Further, instead of HCFC 225, a fluorinated vinyl monomer may be polymerized using supercritical carbon dioxide as a solvent. 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. As a specific method for producing the surfactant, a method described in a fluororesin handbook (published by Takaomi Satokawa, published by Nikkan Kogyo Shimbun, p. 730 to p. 732) can be used.

  Moreover, the silicone type surfactant of this embodiment can be manufactured by superposing | polymerizing the vinyl polymerizable monomer used as the raw material. As a solvent for polymerization, a supercritical fluid (supercritical carbon oxide) can be used. Many raw materials having a structure similar to that of polydimethylsiloxane are commercially available (see, for example, the catalog of AMAX Co.), and even when they are used, a silicone surfactant can be obtained. Among these, it is preferable to use a silicon-containing compound (trade name: MONASIL-PCA, manufactured by CRODA Co., Ltd.) because good granulation properties can be obtained.

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

(Dispersant)
The dispersant is not particularly limited, and for example, organic fine particles and inorganic fine particles can be used. Among these, it is preferable to use 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. More preferably it is used. It is preferable to use a dispersant that melts into a compressive fluid described later.

  Examples of the organic fine particles described above 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, it is preferable to use silica.

  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. As a specific example, an example of modifying the surface of silica using 3- (trimethylsilyl) propyl methacrylate as a silane coupling agent is shown.

The acrylic-modified silica obtained in the above reaction formula example has a high affinity for supercritical carbon dioxide on the silica side and a high affinity for toner on the acrylate side. Note that this modification example is merely an example, and for example, surface modification of silica may be performed by other methods.

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 ;
Etc. can be used.

  The content of the dispersant is preferably 0.1% by mass to 30% by mass with respect to the raw material of the toner. The above-mentioned dispersant is preferably used alone, but from the viewpoint of controlling the toner particle size and toner chargeability, other surfactants may be used in combination.

(Charge control agent)
Although there is no restriction | limiting in particular as a charge control agent, When a colored charge control agent is used, since a color tone may change, it is preferable to use a colorless or near-white charge control agent.

  Examples of specific charge control agents include, for example, nigrosine dyes, triphenylmethane dyes, chromium-containing metal complex dyes, molybdate chelate pigments, rhodamine dyes, alkoxy amines, quaternary ammonium salts (fluorine-modified 4 Secondary ammonium salts or compounds thereof, tungsten simple substances or compounds thereof, fluorine activators, metal salts of salicylic acid, metal salts of salicylic acid derivatives, and the like. Among the charge control agents described above, it is preferable to use a metal salt of a salicylic acid metal salt or a salicylic acid derivative. These may be used alone or in combination of two or more.

  The metal used for the metal salt is not particularly limited, and examples thereof include aluminum, zinc, titanium, strontium, boron, silicon, nickel, iron, chromium, and zirconium.

  A commercially available product may be used as the charge control agent. Examples of commercially available charge control agents include quaternary ammonium salt Bontron P-51, oxynaphthoic acid metal complex E-82, salicylic acid metal complex E-84, and phenol condensate E. -89 (above, Orient Chemical Industry Co., Ltd.), quaternary ammonium salt molybdenum complex TP-302, TP-415, salicylic acid metal complex TN-105 (above, Hodogaya Chemical Industry Co., Ltd.), quaternary ammonium Copy charge PSY VP2038 of salt, copy blue PR of triphenylmethane derivative, copy charge of quaternary ammonium salt NEG VP2036, copy charge NX VP434 (manufactured by Hoechst), LRA-901, LR-147 of boron complex ( Nippon Carlit Co., Ltd.), quinacridone, azo pigments, other sulfonic acid groups, potassium Examples thereof include a polymer compound having a functional group such as a ruboxyl group or a quaternary ammonium salt.

  The addition amount of the charge control agent is not particularly limited, but is preferably 0.5 parts by mass or more and 5 parts by mass or less, and preferably 1 part by mass or more and 3 parts by mass or less with respect to 100 parts by mass of the above-described pressure plastic material. It is more preferable that When the addition amount of the charge control agent is less than 0.5 parts by mass, the charging characteristics of the toner may be deteriorated. On the other hand, when the addition amount of the charge control agent exceeds 5 parts by mass, the chargeability of the toner becomes too large, so that the effect of the main charge control agent is diminished and the electrostatic attractive force with the developing roller is increased. In some cases, the fluidity of the developer is lowered and the image density is lowered.

(Still other ingredients)
The toner of this embodiment may further contain other components. Still other components include a fluidity improver and a cleaning property improver. The fluidity improver refers to an agent having a function of performing a surface treatment on a toner to improve hydrophobicity and prevent deterioration of fluidity characteristics and charging characteristics even under high humidity.

  Specific examples of the fluidity improver in the present embodiment include a silane coupling agent, a silylating agent, a silane coupling agent having a fluorinated alkyl group, an organic titanate coupling agent, an aluminum coupling agent, and silicone oil. , Modified silicone oil, and the like.

  The cleaning property improving agent in the present embodiment refers to one having a function of removing the developer after transfer remaining on the photoreceptor or the primary transfer medium.

  Specific examples of the cleaning improver include fatty acid metal salts such as zinc stearate, calcium stearate and stearic acid, polymer fine particles produced by soap-free emulsion polymerization such as polymethyl methacrylate fine particles and polystyrene fine particles.

  As the polymer fine particles, those having a relatively narrow particle size distribution are preferably used, and those having a volume average particle size of 0.01 μm or more and 1 μm or less are preferably used.

[Compressible fluid]
Next, the compressible fluid used in the present embodiment will be described with reference to the drawings.

  FIG. 3 shows an example of a phase diagram for explaining the state of a substance under a certain temperature and pressure condition. FIG. 4 shows an example of a phase diagram for explaining the compressible fluid in the present embodiment.

  The compressible fluid in this embodiment has properties such as fast mass transfer and heat transfer and low viscosity, and density, dielectric constant, solubility parameter, free deposition, etc. are continuously changed by changing temperature and pressure. It has a property that changes greatly. In general, a compressive fluid has a smaller interfacial tension than an organic solvent, and therefore can follow even a minute undulation (surface) and can be wet with a compressive fluid.

  Further, when a compressible fluid is used as a reaction field, it is easy to separate and remove from a product such as toner by returning to normal pressure, and it is easy to collect and reuse. Therefore, in the toner manufacturing method of the present embodiment, it is possible to reduce the burden on the environment at the time of manufacturing as compared with the conventional manufacturing method using water, an organic solvent, or the like.

  The “compressible fluid” in the present embodiment refers to a substance that exists in any region of (1), (2), or (3) in FIG. 4 in the phase diagram represented in FIG. Means. 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 refers to a fluid that exists as a non-condensable dense fluid in a temperature and / or pressure range 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).

  Specific examples of substances that can be used as the compressive fluid in the present embodiment include, for example, carbon monoxide, carbon dioxide, dinitrogen monoxide, nitrogen, air, oxygen, argon, helium, neon, krypton, and methane. Ethane, propane, 2,3-dimethylbutane, ethylene, ammonia, normal butane, isobutane, normal pentane, isobutane, chlorotrifluoromethane, and the like. These compressive fluids may be used alone or in combination of two or more.

  In the present embodiment, the compressive fluid for melting the pressure plastic material (hereinafter also referred to as a first compressive fluid) is not particularly limited, but a supercritical state can be easily created among the compressible fluids described above. Carbon dioxide is preferably used from the viewpoint of non-flammability and high safety, and when a toner is produced, a toner having a hydrophobic surface can be obtained.

  In the manufacturing method of the present embodiment, a second compressive fluid that is supplied to the melt when the melt is ejected may be used separately from the first compressive fluid.

  The second compressive fluid is not particularly limited, and the compressive fluid described above can be used, but is a compressive fluid (oxygen, nitrogen, etc.) having a maximum reversal temperature of 800 K or less, and contains nitrogen. It is preferred to use a compressible fluid. In addition, the term “containing nitrogen” as used herein means containing nitrogen molecules, and examples thereof include air.

  Nitrogen has a maximum reversal temperature of 620K and a lower maximum reversal temperature compared to substances such as carbon dioxide (maximum reversal temperature 1500K). Thereby, when the pressure of nitrogen is lowered, the temperature drop based on the Joule-Thompson effect is smaller than when the pressure of carbon dioxide or the like is lowered. On the other hand, when a compressive fluid having a high maximum reversal temperature, such as carbon dioxide, is used as the second compressive fluid, cooling by the Joule-Thomson effect becomes excessive when the melt is injected. There is a case. Thereby, since the melt is solidified before being granulated, a fibrous or coalesced product may be mixed. In addition, if the cooling is excessive, the melt is solidified inside a nozzle or the like that injects the melt, so that depending on the reaction time, it may be difficult to produce particles with a small particle size distribution. .

  In the present embodiment, the compressive fluid may be used in combination with an entrainer (cosolvent). Specific 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 toner of the exemplary embodiment is manufactured, in order to easily control the solubility of the toner composition, other fluids may be used in combination with the above-described compressive fluid. Specific examples of other fluids include methane, ethane, propane, butane, and ethylene.

[Particle production equipment]
Next, a particle manufacturing apparatus that can be used in the present embodiment will be described with reference to FIG. In FIG. 5, the schematic of the particle | grain manufacturing apparatus based on one Embodiment of this invention is shown.

  In FIG. 5, the particle production apparatus 1 includes a cell 11, a pump 12, a valve 13, a mixing apparatus 14, a mixing apparatus 15, a back pressure valve 16, and a nozzle 17 that are super high pressure pipes (10 a, 10 b, 10 c, 10 d, 10 e, 10 f). ) Through the above-described configuration.

  In the particle production apparatus 1, the cell 21, the pump 22, and the valve 23 are connected in this order via an ultrahigh pressure pipe (10g, 10h), and the valve 23 is a mixing apparatus via the ultrahigh pressure pipe (10i). 14.

  Further, in the particle production apparatus 1, a cylinder 31, a pump 32, and a valve 33 are connected via an ultra high pressure pipe (10j, 10k), and the valve 33 is connected to the mixing apparatus 15 via an ultra high pressure pipe (10l). Has been. In addition, a heater 38 is installed so that the inside of the ultrahigh pressure pipe 10l can be heated.

  The cell 11 has a temperature controller (not shown) and has a function of heating the pressure plastic material previously filled in the cell 11. In addition, a stirring device is attached to the cell 11 so that the pressure plastic material can be stirred and heated uniformly.

  The pump 12 has a function of sending the pressure plastic material in the cell 11 to the mixing device 14 side. The valve 13 can open and close the path between the pump 12 and the mixing device 14 to adjust the flow rate of the pressure plastic material.

  The cell 21 has a temperature controller (not shown), and has a function of heating the release agent previously filled in the cell 21. Further, the cell 21 is provided with a stirring device, whereby the release agent can be stirred and heated uniformly.

  The pump 22 has a function of sending the release agent in the cell 21 to the mixing device 15 side. The valve 23 can open and close the path between the pump 22 and the mixing device 14 to adjust the flow rate of the release agent.

  The mixing device 14 has a function of continuously contacting and mixing the pressure plastic material supplied from the cell 11 and the release agent supplied from the cell 21. Specific examples of the mixing device 14 include a known T-shaped joint, a swirl mixer having a swirl flow, and a center collision type mixer in which two liquids collide with each other in a mixing unit.

  The cylinder 31 is a pressure vessel for storing the first compressive fluid and supplying it to the mixing device 15. As the compressive fluid stored in the cylinder 31, air, nitrogen, and carbon dioxide are preferably used for reasons such as cost and safety, and among these, carbon dioxide is more preferably used. Note that the substance stored in the cylinder 31 may be in a state of gas, liquid, or the like as long as the temperature is adjusted in the mixing device 15 to become a compressible fluid (first compressive fluid).

  The pump 32 has a function of sending out the compressible fluid stored in the cylinder 31 to the mixing device 15 side.

  The valve 33 has a function of adjusting (including shutting off) the flow rate of the compressive fluid by opening and closing a path between the pump 32 and the mixing device 15.

  The mixing device 15 has a function of continuously contacting and mixing the pressure plastic material containing the release agent supplied from the mixing device 14 and the first compressive fluid supplied from the cylinder 31. The mixing device 15 is not particularly limited as long as the pressure plastic material containing the release agent and the first compressive fluid can be homogeneously mixed. It may be a mixing device.

  The back pressure valve 16 has a function of adjusting (including shutting off) the flow rate and pressure of the melt supplied from the mixing device 15 by opening and closing the path between the mixing device 15 and the nozzle 17.

  Although it does not specifically limit as the nozzle 17, It is preferable to use a direct spray nozzle. The diameter of the nozzle 17 is not particularly limited as long as the pressure at the time of injection can be maintained constant. However, when the diameter of the nozzle 17 is too large, the pressure at the time of injection decreases, the melt viscosity increases, and fine particles are obtained. Can be difficult. Moreover, the supply pump for maintaining the pressure may need to be enlarged. On the other hand, when the nozzle diameter of the nozzle 17 is too small, the melt may be easily clogged with the nozzle 17. From the above viewpoint, the nozzle diameter of the nozzle 17 is preferably 500 μm or less, more preferably 300 μm or less, and further preferably 100 μm or less. Further, the nozzle diameter of the nozzle 117 is preferably 5 μm or more, more preferably 20 μm or more, and further preferably 50 μm or more. In order to prevent clogging of the nozzle 17, a porous filter (not shown) may be installed between the back pressure valve 16 and the nozzle 17.

  Next, with reference to FIG. 6, another embodiment of the particle manufacturing apparatus will be described. FIG. 6 shows a schematic diagram of a particle production apparatus according to another embodiment of the present invention.

  In the description of the particle manufacturing apparatus 2 in FIG. 6, the same reference numerals are used for the means, mechanisms or apparatuses common to the particle manufacturing apparatus 1 in FIG. 5, and the description may be omitted.

  In the particle production apparatus 2, the cell 11, the pump 12, the valve 13, the mixing apparatus 14, the mixing apparatus 15, the back pressure valve 16, and the nozzle 17 are connected via ultra high pressure pipes (10a, 10b, 10c, 10d, 10e, 10f). , In this order.

  In the particle production apparatus 2, a cell 21, a pump 22, and a valve 23 are connected in this order via an ultrahigh pressure pipe (10g, 10h), and the valve 23 is a mixing apparatus via an ultrahigh pressure pipe (10i). 14.

  Further, in the particle production apparatus 2, a cylinder 31, a pump 32, and a valve 33 are connected via an ultrahigh pressure pipe (10j, 10k), and the valve 33 is connected to the mixing apparatus 15 via an ultrahigh pressure pipe (10l). Has been. In addition, a heater 38 is installed so that the inside of the ultrahigh pressure pipe 10l can be heated.

  Furthermore, in the particle production apparatus 2, a cylinder 41, a pump 42, and a back pressure valve 46 are connected via an ultra high pressure pipe (10m, 10n), and the back pressure valve 46 is connected to the ultra high pressure pipe 10f by an ultra high pressure pipe 10o. Has been. In addition, a heater 48 is installed, and the super high pressure pipe 10o can be heated.

  The cylinder 41 is a pressure vessel for storing and supplying the second compressive fluid. As the second compressive fluid, it is preferable to use air, nitrogen, argon, helium, carbon dioxide for reasons such as safety. Among these, air, nitrogen, carbon dioxide are used from the viewpoint of cost and the like. It is preferable to do. In addition, the state of the substance stored in the cylinder 41 is a gas or a liquid, and may be made a compressive fluid in the middle path.

  The pump 42 has a function of sending the second compressive fluid stored in the cylinder 41 to the nozzle 17 side. The back pressure valve 46 has a function of adjusting (including shutting off) the flow rate of the second compressive fluid by opening and closing the path between the pump 42 and the nozzle 17. At this time, a pressure accumulator (not shown) may be installed between the pump 42 and the back pressure valve 46.

  The compressive fluid heated by the heater 48 is cooled at the outlet of the nozzle 17 by the Joule-Thomson effect. Therefore, it is preferable that the compressive fluid is sufficiently heated by the heater 48 to be in the state of the supercritical fluid (1) shown in the phase diagram of FIG.

  In the particle manufacturing apparatus 2 described above, the melt is injected from the nozzle 17 while supplying the second compressive fluid to the raw material melt including the first compressive fluid obtained by the mixing apparatus 15. In this case, since the viscosity of the melt of the pressure plastic material can be lowered by the pressure of the second compressive fluid, process design with high workability can be achieved. Thereby, even if the amount of the release agent component added to the raw material is small and the molecular weight of the pressure plastic material is high, particles can be produced efficiently.

  In the particle production apparatus (1, 2), a known joint or the like is used as the mixing apparatus (14, 15). However, in conventional static mixers, for example, when fluids having different viscosities, such as molten resin and compressive fluid, are mixed, it is often difficult to mix both fluids uniformly. Therefore, it is preferable that the static mixer of this embodiment has the mixing element in the 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. When such a static mixer is used, 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. Further, in the static mixer according to another embodiment, an element in which a large number of elements composed of honeycomb-like plates composed of polygonal chambers are superposed may be used. In this type of static mixer, the fluid is mixed by being dispersed, inverted, and swirled by sequentially moving a small chamber inside the tube from the center to the outside of 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 allowed to pass through these static mixers, the low-viscosity fluid is not subjected to mixing action by the element, and the in-tube element and the tube housing May pass through the gap, and may not be homogeneously mixed. As countermeasures against this 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.

[Toner Production Method]
Next, a toner manufacturing method using the particle manufacturing apparatus (1, 2) according to an embodiment of the present invention will be described.

The toner manufacturing method of the present embodiment is a toner manufacturing method including a binder resin containing a pressure plastic material and a release agent,
A mixing step of continuously forming the mixture by continuously supplying and joining the pressure plastic material and the release agent, and continuously supplying to the next step (melting step);
A melting step of contacting the first compressive fluid and the mixture to melt the mixture;
A granulation step of spraying and granulating the melt obtained in the melting step;
Have

(Mixing process)
When using the particle production apparatus (1, 2), in the melting step, first, raw materials such as a pressure plastic material and other materials (for example, a colorant) are filled in the cell 11. When other materials such as a colorant are included as raw materials, it is preferable that these components are mixed in advance with a mixer or the like, melted and kneaded with a roll mill or the like, and then charged into the cell 11.

  The release agent is filled in the cell 21.

  Next, the cell 11 is sealed, and the pressure plastic material is melted by stirring and heating the raw material with the stirring device of the cell 11. The temperature in the cell 11 is not particularly limited as long as the pressure plastic material melts.

  Similarly, the cell 21 is sealed, and the release agent is melted by stirring and heating the release agent by the stirring device of the cell 21. The temperature in the cell 21 is not particularly limited as long as the release agent is melted.

  Next, the pump 12 is operated and the valve 13 is opened. Similarly, the pump 22 is operated and the valve 23 is opened. By this operation, the pressure plastic material supplied from the cell 11 and the release agent supplied from the cell 21 are continuously brought into contact with each other in the mixing device 14 and mixed uniformly.

  Note that the release agent may be melt-kneaded with other raw materials in advance and filled in the cell 11, but in this case, depending on the properties of the pressure plastic material and the release agent, the release agent may be separated in the cell 11. . Therefore, in this embodiment, a predetermined amount of the release agent can be reliably contained in the toner by supplying the pressure plastic material and the release agent using different cells.

(Melting process by contact with compressible fluid)
Next, a melting process in which a raw material such as a pressure plastic material is swollen by being brought into contact with a compressive fluid and plasticized, semi-liquefied, or liquefied will be described.

  The pump 32 is operated to pressurize the first compressive fluid stored in the cylinder 31 and the valve 33 is opened. As a result, the first compressive fluid is supplied into the mixing device 15. In the present embodiment, a carbon dioxide (carbon dioxide) cylinder is used as the cylinder 31.

  The supplied first compressive fluid is heated by the heater 38 in the ultra high pressure pipe 10l. The set temperature of the heater 38 is not particularly limited as long as the supplied carbon dioxide becomes a compressible fluid, but is preferably a temperature lower than the melting point of the release agent.

  The mixture of the release agent and the pressure plastic material supplied from the mixing device 14 and the first compressive fluid supplied from the cylinder 31 are continuously contacted in the mixing device 15 to be uniformly mixed. The Thereby, the mixture melts.

  The viscosity of the melt obtained by melting the mixture is preferably 500 mPa · s or less.

  In the embodiment using the particle production apparatus (1, 2), the pressure plastic material is previously melted in the cell 11 so that the viscosity difference between the pressure plastic material and the compressive fluid is reduced as much as possible. Can be mixed. Therefore, a more homogeneous melt can be obtained. In the present embodiment, the pressure plastic material is melted by applying heat, but the pressure plastic material may be melted by applying pressure. Further, the pressure plastic material may be melted by applying both heat and pressure.

(Granulation process)
Next, a granulation process for producing particles (in this embodiment, toner) by jetting the melt obtained by the melting process will be described.

  The granulation step is carried out by spraying the pressure plastic material melt from the nozzle 17 and granulating.

  Methods for granulating fine particles using carbon dioxide as the compressive fluid include a RESS method (Rapid Expansion of Supercritical Solution) and a PGSS method (Particles from Gas Saturated Solution).

  The RESS method is a rapid expansion method in which a material that becomes a solute is saturated and dissolved in a supercritical fluid under high pressure, and fine particles are precipitated by utilizing a rapid decrease in solubility due to rapid decompression from a nozzle.

  In the RESS method, the pressure of the supercritical fluid instantaneously decreases to atmospheric pressure at the nozzle outlet, and the saturated solubility of the solute decreases accordingly. That is, a large degree of supersaturation is achieved in a very short time, and as a result, a large number of fine aggregate nuclei are generated and deposited with little growth. As a result, submicron particles can be obtained.

  On the other hand, in the PGSS method, a supercritical fluid is saturatedly dissolved in a melt of a pressure plastic material (in the present invention, operated at a saturated dissolution concentration or less), and liquid is sprayed through a nozzle to rapidly reduce the pressure. The solubility of the supercritical fluid that has been dissolved in the melt due to the reduced pressure rapidly decreases, and this becomes bubbles to break up the melt, and fine particles are generated by the cooling effect accompanying adiabatic expansion.

  When using the particle manufacturing apparatus 1, the melt obtained by contacting the compressive fluid and the mixture in the mixing device 15 is injected from the nozzle 17 by opening the back pressure valve 16. At this time, the pumps (12, 22, 32), a temperature controller (not shown), and the like are controlled so that the temperatures of the cells 11, 21, and the mixing devices 14, 15 are maintained constant. In addition, the pressure in the mixing apparatus 15 is not specifically limited.

  The melt injected from the nozzle 17 becomes particles and then solidifies. When the particle production apparatus 1 is used, the mixture and the compressive fluid are continuously brought into contact with each other by the mixing apparatus 15 and the obtained melt is supplied to the nozzle 17. Can be granulated.

  When using the particle production apparatus 2, the pump 42 is operated to open the back pressure valve 46, whereby the second compressible fluid stored in the cylinder 41 is supplied to the nozzle 17. In the present embodiment, a nitrogen cylinder is used as the cylinder 41.

  The pressure of the second compressive fluid to be supplied is not particularly limited, but is preferably 1 MPa or more, more preferably 10 MPa or more and 200 MPa or less, and particularly preferably 31 MPa or more and 100 MPa or less. When the pressure applied to the second compressive fluid is less than 1 MPa, the plasticizing effect to the extent that the pressure plastic material can be granulated may not be obtained. On the other hand, there is no particular upper limit on the pressure, but the equipment cost increases as the pressure increases.

  The supplied second compressive fluid is heated by the heater 48 in the ultra high pressure pipe 10o. The set temperature of the heater 48 is not particularly limited as long as the supplied nitrogen is a temperature at which the supplied nitrogen becomes a compressive fluid and is a temperature lower than the melting point of the release agent.

  Next, the back pressure valve 16 is operated to supply a melt of pressure plastic material from the mixing device 15 to the nozzle 17. Thereby, a melt can be injected under atmospheric pressure from a nozzle 17 by a pressure difference, supplying the 2nd compressive fluid to a melt.

  In the embodiment in which the second compressive fluid is supplied, since the solid content concentration of the melt to be injected is lowered, it is preferable because 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 (exit line speed) is increased, and the shearing force on the melt is increased due to the improvement of the exit line speed. 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 17 is alleviated, so that the nozzle 17 is hardly clogged.

  The melt injected from the nozzle 17 becomes particles and then solidifies. In this case, uniform fine particles without coalescence can be produced over a long period of time due to the synergistic effect of lowering the viscosity of the melt and lowering the solid content concentration. In addition, the shape of the particles to be produced is also stabilized uniformly.

[Particles obtained in this embodiment]
In the method for producing particles (toner) according to the present embodiment, particles (toner) can be produced without using an organic solvent by using a compressive fluid. Therefore, particles substantially free of organic solvent can be obtained. In addition, the term “particles do not substantially contain an organic solvent” as used herein refers to a state in which the content of the (organic) solvent in the particles measured by the following measurement method is below the detection limit.

A method for measuring the residual solvent in the particles will be described below. 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 using gas chromatography (GC-14A, SHIMADZU), and the residual solvent concentration is measured by quantifying the solvent and residual monomers in the particles. In the present embodiment, the measurement conditions during the analysis are as follows.
Apparatus: Shimadzu GC-14A;
Column: CBP20-M 50-0.25;
Detector: FID;
Injection volume: 1-5 μl;
Carrier gas: He 2.5 kg / cm ² ;
Hydrogen flow rate: 0.6 kg / cm ² ;
Air flow rate: 0.5 kg / cm ² ;
Chart speed: 5 mm / min;
Sensitivity: Range101 × Atten20;
Column temperature: 40 ° C;
Injection Temp: 150 ° C .;
It was.

  Further, the average of the maximum ferret diameter of the release agent particles and cavities is obtained as follows. The cross section of the particles is observed with an electron microscope or the like, a cross-sectional photograph is taken, the cross-sectional photograph is processed with image processing software, and binarized to identify the release agent part or the cavity part. Among the maximum release diameter of the identified release agent particles or cavities, 30 points were selected in order from the largest, and the average was taken as the average of the maximum release diameter of the release agent or cavity.

[toner]
When the toner is produced according to the exemplary embodiment, the shape, size, and other characteristics of the obtained toner are not particularly limited, but image density, average circularity, mass average particle diameter, mass average particle diameter as shown below A toner having a ratio (mass average particle size / number average particle size) to the number average particle size is preferable.

The image density of the toner is a density value measured using a spectrometer (manufactured by X-Light, 938 Spectrodensitometer), preferably 1.90 or more, and more preferably 2.00 or more. More preferably, it is more preferably 2.10 or more. When the toner image density is less than 1.90, the image density is low, so that a high-quality image may not be obtained. The image density of the toner 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.) is 1.00 ± 0.00. A solid image of 05 mg / cm ² was formed under the condition that the surface temperature of the fixing roller was 160 ± 2 ° C., and the image density at any six locations in the obtained solid image was measured using the spectrometer. It can measure by measuring and calculating the average value.

  The average circularity of the toner can be defined by 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. 0.950 or more and 0.975 or less is more preferable. Further, the toner particles having an average circularity of less than 0.94 are preferably 15% by mass or less. When the average circularity is less than 0.900, satisfactory transferability and high quality images free from dust may not be obtained. Further, when the average circularity exceeds 0.980, in an image forming system employing blade cleaning or the like, a cleaning failure may occur on the photoreceptor or the transfer belt, and stains on the image may occur. . Specifically, for example, in the case of forming an image with a high image area ratio such as a photographic image, the toner that has formed an untransferred image due to poor paper feed or the like is stored on the photosensitive member as a transfer residual toner. Dirt may occur. In addition, the charging roller that contacts and charges the photosensitive member may be contaminated, and the original charging ability may not be exhibited.

The average circularity referred to here 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, first, fine dust is removed by passing through a filter. As a result, the number of particles in a measurement range (for example, an equivalent circle diameter of 0.60 μm or more and less than 159.21 μm) in 10 ⁻³ cm ³ water is 20 or less. Prepare the water adjusted so that 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) is added. , 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 flow path (expanding along the flow direction) of a flat and flat transparent flow cell (thickness: about 200 μm). 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 opposite to each other. While the sample dispersion is flowing, strobe light is irradiated at 1/30 second intervals to obtain an image of 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, 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, the toner may be fused to the surface of the carrier during a long period of stirring in the developing device with a two-component developer, and the charging ability of the carrier may be reduced. In addition, in the case of a one-component developer, toner filming on the developing roller and toner thinning are likely to cause toner fusion to a member such as a blade. Further, when the mass average particle diameter exceeds 10 μm, it may be technically difficult to obtain a high-resolution and high-quality image. In addition, when the balance of the toner in the developer is performed, the variation in the particle diameter of the toner may become large.

  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 1.00 or more and 1.25 or less, and is 1.00 or more and 1.10 or less. More preferably. 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 a two-component developer, the 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 may be thinned and toner fusion to a member such as a blade may occur easily, and it may be technically difficult to obtain a high-resolution and high-quality image. Further, when the balance of the toner in the developer is performed, the variation in the toner particle diameter may become large.

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.

  The content of the release agent in the toner can be determined from, for example, endothermic characteristics by differential scanning calorimetry (DSC) measurement. In the present embodiment, the measurement conditions during the DSC measurement are as follows.

Apparatus: DSC-60A (manufactured by Shimadzu Corporation);
Temperature increase rate: 1 ° C / min, 10 ° C / min, or 20 ° C / min;
Measurement start temperature: 20 ° C .;
Measurement end temperature: 180 ° C;
It was.

  Specifically, about 5 mg of a sample is precisely weighed and placed in a silver pan, and measurement is performed. A silver empty pan is used as a reference.

  When the toner is used as a sample, when the maximum endothermic peak (endothermic peak derived from the binder resin) does not overlap with the endothermic peak of the release agent, each peak is separated from the peak derived from the binder resin and the release mold. It can be the peak of the agent. On the other hand, when the toner is used as a sample, if the endothermic peak of the release agent overlaps the maximum endothermic peak of the binder resin, it is necessary to separate each peak. Peak separation in DSC measurement can be performed by a known method.

  Next, DSC measurement of the release agent alone is performed to obtain endothermic characteristics. The release agent content in the toner can be determined from this endothermic peak and the above-mentioned peak in the DSC measurement of the toner. When the release agent is easily compatible with the resin component, it is necessary to consider the compatibility ratio in the content of the release agent. The compatibility is calculated based on the endothermic amount of the molten mixture obtained in advance and the endothermic amount of the release agent alone, which are obtained by mixing the molten mixture of the resin component and the release agent at a predetermined ratio. Calculated from the value divided by the calculated theoretical endothermic amount.

  In addition, content of components other than a binder resin component can be measured by a well-known analysis means. If analysis is difficult, determine the amount of residual ash from the toner, and add the amount of components other than the binder resin to be incinerated, such as a release agent, as the content of components other than the binder resin. Then, it can be determined by subtracting from the toner mass.

  The incineration residual ash content in the toner is obtained by the following procedure. About 2 g of toner is placed in a pre-weighed 30 ml magnetic crucible. Put the crucible in an electric furnace, heat at about 900 ° C. for about 3 hours, let cool in the electric furnace, let it cool in a desiccator at room temperature for more than 1 hour, weigh the mass of the crucible containing the incineration residual ash, Incineration residual ash is calculated by subtracting the mass of the crucible.

  The maximum endothermic peak is a peak where the endothermic amount is maximum when there are a plurality of peaks. In the maximum endothermic peak, the temperature width at half the height (1 / 2h) is obtained with respect to the peak height (h), and this is defined as the half width.

[Developer]
Next, a developer using the toner of this embodiment will be described. The developer according to this embodiment is not particularly limited as long as it has the above-described toner, and can be a one-component developer or a two-component developer having a toner and a magnetic carrier.

  In addition, as described above, color toners such as yellow, cyan, magenta, and black may be used, and colorless and transparent clear toners may be used.

(Magnetic carrier)
The magnetic carrier of the two-component developer described above is not particularly limited as long as it contains a magnetic material, and examples thereof 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 view showing the image forming apparatus according to the present embodiment.

  The image forming apparatus 200 develops the electrostatic latent image into a visible image using the toner manufactured by the above-described particle manufacturing method, transfers the visible image to a sheet as an example of a recording medium, and fixes the image. To 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 case, and may be a copying machine, a facsimile, or the like.

  As shown in FIG. 7, the image forming apparatus 200 includes a paper feed unit 210, a transport unit 220, an image forming unit 230, a transfer unit 240, and a fixing unit 250.

  The sheet feeding unit 210 includes a sheet feeding cassette 211 on which sheets to be fed are stacked, and a sheet feeding roller 212 that feeds sheets stacked on the sheet feeding cassette 211 one by one.

  The conveyance unit 220 waits between a roller 221 that conveys the sheet fed by the sheet feed roller 212 in the direction of the transfer unit 240 and a leading end of the sheet conveyed by the roller 221, and waits for the sheet 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.

  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 configuration except that the developers used are different. In FIG. 7, each image forming unit is provided so as to be rotatable clockwise, and a photosensitive drum (231Y, 231C, 231M, 231K) for carrying an electrostatic latent image and a toner image, and a photosensitive drum (231Y). , 231C, 231M, 231K) uniformly charging the surface of each charger (232Y, 232C, 232M, 232K), and each toner cartridge (237Y, 237Y, 232K, 232K, 232K) 237C, 237M, 237K) and the toner supplied from the toner cartridge (237Y, 237C, 237M, 237K) with the electrostatic latent image formed on the surface of the photosensitive drum (231Y, 231C, 231M, 231K) by the exposure device 233. Developing devices (234Y, 234C, 234M, 234K) that develop toner images using toner, and transfer Each static eliminator (235Y, 235C, 235M, 235K) for neutralizing the surface of the photosensitive drum (231Y, 231C, 231M, 231K) after the toner image is primarily transferred to the body, and a static eliminator (235Y, 235C, 235M, Each cleaning device (236Y, 236C, 236M, 236K) for removing the transfer residual toner remaining on the surface of each photosensitive drum (231Y, 231C, 231M, 231K) that has been neutralized by 235K).

  The exposure unit 233 reflects the laser light L emitted from the light source 233a on the basis of 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 is driven by a drive roller 241 and a driven roller 242, and 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. A primary transfer roller (244Y, 244C, 244M, 244K) provided opposite to the photosensitive drum 231 with the transfer belt 243 interposed therebetween, and a secondary opposing roller with the intermediate transfer belt 243 interposed therebetween at the transfer position of the toner image onto the paper. And a secondary transfer roller 246 provided to face the roller 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 includes 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 pressably presses the heating roller 251 against the contact surface (nip). Part) is formed. In the present exemplary embodiment, the fixing lower limit temperature means a lower limit temperature at which the toner is fixed.

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

  In the above-described embodiment, the case where the manufacturing apparatus used for the particle manufacturing method is the particle manufacturing apparatus (1, 2) shown in FIGS. 5 to 6 is described. However, the present invention is limited to this case. Not.

  Moreover, although embodiment mentioned above demonstrated the case where the melt containing a pressure plastic material and a compressive fluid was injected in air | atmosphere, this invention is not limited to this case. In addition, the melt can be injected into an environment in which the pressure of the melt is higher than that in the atmosphere and lower than that in the nozzle 32. At this time, 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.

[Example]
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 addition, in the following, a part refers to a mass part.

(Synthesis of polyester resin 1 (pressure plastic material))
In a reaction vessel equipped with a condenser, a stirrer and a nitrogen introduction 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 allowed to react at 230 ° C. for 8 hours under normal pressure. Moreover, after making it react under reduced pressure of 10-15 mmHg for 5 hours, 44 parts of trimellitic anhydride was put into the reaction container, and [polyester resin 1] was obtained by making it react at 180 degreeC and a normal pressure for 2 hours.

  The obtained [Polyester Resin 1] had 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. In the measurement, first, a sample was set in a high-pressure measurement cell, the inside of the cell was replaced with carbon dioxide, and then pressurized to a predetermined pressure. And the glass transition temperature was measured by heating up to 200 degreeC with the temperature increase rate of 0.5 degree-C / min.

(Synthesis of polyester resin 2 (pressure plastic material))
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. Furthermore, by reacting under a reduced pressure of 5 mmHg to 20 mmHg until the weight average molecular weight reached about 17,000, [Polyester Resin 2] (crystalline polyester resin) having a melting point of 63 ° C. was obtained. The gradient of the change in glass transition temperature with respect to the pressure of [Polyester resin 2] was −5 ° C./MPa.

(Synthesis of polyurethane resin 1 (pressure plastic material))
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. Then, 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. Furthermore, the reaction was performed under a reduced pressure of 5 mmHg to 20 mmHg until the weight average molecular weight reached about 6,000. 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. Thereafter, 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 glass transition temperature with respect to the pressure of [Polyurethane resin 1] was −6 ° C./MPa.

  Table 1 shows a summary of parameters such as glass transition temperature Tg, melting point Ta, and softening temperature Tb of the various resins obtained.

Example 1
In Example 1, toner was manufactured using the particle manufacturing apparatus 2 of FIG. A carbon dioxide (carbon dioxide) cylinder was used as the cylinder 31 and a nitrogen cylinder was used as the cylinder 41.

In Example 1, as a raw material,
95 parts of polyester resin 1;
5 parts of a colorant (copper phthalocyanine blue);
5 parts of paraffin wax (melting point 79 ° C.);
It was used.

  The raw materials excluding the paraffin wax were mixed with a mixer and then melt-kneaded using a two-roll mill, and the kneaded product was rolled and cooled. This kneaded material was put into the cell 11 of the particle production apparatus 2 of FIG. 6 and heated to 150 ° C.

  Paraffin wax was put into the cell 21 of the particle production apparatus 2 and heated to 150 ° C.

  Next, the pump 12 was operated, the valve 13 was opened, and the kneaded material was supplied to the mixing device 14. Moreover, the pump 22 was operated, the valve 23 was opened, and the paraffin wax was supplied to the mixing device 14, whereby the mixture and the paraffin wax were mixed by the mixing device 14 to obtain a raw material mixture.

  Next, the pump 32 was operated, the valve 33 was opened, and carbon dioxide was introduced as a first compressive fluid at 150 ° C. and 65 MPa. Further, the raw material mixture obtained by the mixing device 14 is supplied to the mixing device 15, and the raw material mixture and the first compressive fluid are continuously brought into contact with each other and mixed by the mixing device 15 to obtain a melt. .

  The viscosity of the obtained melt was 4 mPa · s. In addition, the viscosity of the melt was measured using a vibration viscometer (XL7) manufactured by Hydramotion under the following conditions. A sample and a compressible fluid (carbon dioxide) were introduced into a high-pressure cell, and the viscosity was measured under conditions of 150 ° C. and 65 MPa.

  Next, the back pressure valve 46 was opened, and using the pump 42 and the heater 48, supercritical nitrogen was injected from the nozzle 17 as the second compressive fluid so as to maintain 65 MPa and 150 ° C. A nozzle 17 having a hole diameter of 100 μm was used. By opening the back pressure valve 116 in this state, the melt obtained by the contact between the raw material mixture and the first compressive fluid is continuously injected from the nozzle 17 while supplying the second compressive fluid. did. A porous filter was installed between the back pressure valve 16 and the nozzle 17.

  The pump 12, the pump 22, the pump 32, the back pressure valve 16 and the back pressure valve 46 were adjusted so that the melt passing through the ultrahigh pressure pipe 10f was constant at a temperature of 100 ° C. and a pressure of 65 MPa. The injected melt was solidified after being granulated. The solidified toner was designated as [Toner 1].

  The obtained [Toner 1] particles had a volume average particle diameter (Dv) of 5.3 μm, a number average particle diameter (Dn) of 4.7 μm, and Dv / Dn of 1.13. 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.

  Further, the residual solvent concentration in the particles of the obtained [Toner 1] was below the detection limit. The residual solvent concentration was measured using a gas chromatography (GC-14A) manufactured by Shimadzu Corporation.

  The content of the release agent in the particles of the obtained [Toner 1] was 4.8% by mass. The release agent content was determined by the method described above from the endothermic characteristics measured using an automatic differential scanning calorimeter (DSC-60A) manufactured by Shimadzu Corporation.

  Table 2 shows various production conditions in Example 1 and other examples and comparative examples described later.

(Examples 2 to 6)
Except that [Polyester Resin 1] used in Example 1 was changed to [Polyester Resin 2] and the processing temperature, processing pressure, and nozzle diameter were changed to the values shown in Examples 2 to 6 in Table 2, this was carried out. [Toners 2 to 6] were obtained in the same manner as in Example 1.

(Examples 7 and 8)
Except for changing [Polyester resin 1] used in Example 1 to [Polyurethane resin 1] and changing the processing temperature, processing pressure, and nozzle diameter to the values shown in Example 7 and Example 8 of Table 2, [Toners 7 and 8] were obtained in the same manner as in Example 1.

(Comparative Example 1)
Bisphenol A ethylene oxide 2-mole adduct, unmodified polyester (a) obtained from terephthalic acid and phthalic anhydride, bisphenol A ethylene oxide 2-mole adduct, isophthalic acid, terephthalic acid, phthalic anhydride and isophorone diisocyanate Obtained from the isocyanate group-containing prepolymer (b) (Mw: 35000).

  A ketimine compound (c) was obtained from isophoronediamine and methyl ethyl ketone.

  In a beaker, 20 parts of the prepolymer (b), 55 parts of polyester (a), and 78.6 parts of ethyl acetate were added and dissolved by stirring. Next, 10 parts of rice wax (melting point: 61 ° C.) and 4 parts of carbon black were added as a release agent, and the mixture was stirred using a TK homomixer at 40 ° C., 12000 rpm, for 5 minutes. Then, it grind | pulverized on 20 degreeC and the conditions for 30 minutes using the bead mill. The resulting dispersion is hereinafter referred to as toner material oil dispersion (d).

  In a beaker, add 306 parts of ion-exchanged water, 265 parts of a 10% tricalcium phosphate suspension, and 0.2 part of sodium dodecylbenzenesulfonate, and stir using a TK homomixer at 12000 rpm to disperse in water. A liquid (e) was obtained. To the aqueous dispersion liquid (e), 2.7 parts of the toner material oil dispersion liquid (d) and the ketimine compound (c) were added and stirred to advance the urea reaction.

  The dispersion after the reaction (viscosity: 3500 mPa · s) is removed under reduced pressure at a temperature of 50 ° C. or less within 1 hour, and then filtered, washed, dried, and then air-classified, A spherical [Comparative Toner 1] was obtained.

  To 100 parts by mass of the toner obtained in each Example and Comparative Example, 0.7 part by mass of hydrophobic silica and 0.3 part by mass of hydrophobized titanium oxide were added, and the peripheral speed was 8 m / s using a Henschel mixer. Mix for 5 minutes under conditions. The powder after mixing was passed through a mesh having an opening of 100 μm to remove coarse powder.

  In each of the toners obtained in each example, a plurality of release agents were included in the pressure plastic material in the form of particles. On the other hand, in the toner obtained in the comparative example, a part of the release agent was not included in the pressure plastic material, and an area where the release agent protruded from the pressure plastic material was observed.

  Next, 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 are rolled and stirred. Two-component [Developers 1, 2, 3, 7, 10] were prepared by uniformly mixing and charging using a tumbler mixer. The toner used in [Developers 1, 2, 3, 7, 10] corresponds to [Toner 1, 2, 3, 7, comparative toner 1]. For [Toners 4 to 6 and 8], a two-component developer was not prepared.

  Further, 0.7 parts by mass of hydrophobic silica and 0.3 parts by mass of hydrophobic titanium oxide were added to 100 parts by mass of [Toners 1, 2, 3, 7, Comparative toner 1], and the mixture was circulated with a Henschel mixer. The mixture was mixed for 5 minutes under the condition of a speed of 8 m / s to prepare a one-component [developer 11, 12, 13, 17, 20]. The toners used in [Developers 11, 12, 13, 17, 20] correspond to [Toners 1, 2, 3, 7, comparative toner 1], respectively. For [Toners 4 to 6 and 8], a one-component developer was not prepared.

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

[Image density]
After outputting a solid image at an adhesion amount of 0.3 ± 0.1 mg / cm ² , which is a low adhesion amount on plain paper transfer paper (Type 6200, manufactured by Ricoh Co., Ltd.), 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 higher;
○: 1.35 or more and less than 1.4;
Δ: 1.3 or more and less than 1.35;
X: less than 1.3;
It was.

[Toner scattering]
In an environment of a temperature of 40 ° C. and a humidity of 90% RH, an evaluation machine was used that was tuned by remodeling the image forming apparatus (manufactured by Ricoh Co., Ltd., IPSiOColor 8100) to an oilless fixing system. Using the above-described evaluation machine, an image area ratio 5% chart continuous 100,000 sheet output durability test was performed using each developer, and the toner contamination state in the copying machine 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 does not cause a problem;
Δ: Slight dirt is observed;
×: very dirty outside the allowable range, causing a problem;
It was.

[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.). Measured and evaluated according to the following criteria.

(Evaluation criteria)
A: The difference from the blank is less than 0.005;
○: The difference from the blank is 0.005 to 0.010;
(Triangle | delta): The difference with a blank is 0.011-0.02;
X: The difference from the blank exceeds 0.02.
It was.

[Charging stability]
Using each developer, 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;
It was.

[Filming properties]
Filming on the developing roller after the output of 1000 band charts with an image area ratio of 100%, 75%, and 50% and filming on the photoreceptor were observed and evaluated according to the following criteria.

(Evaluation criteria)
A: No filming occurred at all;
○: A slight filming can be confirmed;
Δ: Filming occurs in streaks;
×: Filming occurs on the entire surface;
It was.

[Cleanability]
Transfer residual toner on the photosensitive member that has passed the cleaning process after outputting 1,000 sheets of an image area ratio 95% chart is transferred to a white paper with Scotch tape (manufactured by Sumitomo 3M Limited), and measured with a Macbeth reflection densitometer RD514 type. And evaluated according to the following criteria.

(Evaluation criteria)
A: The difference from the blank is less than 0.005;
○: The difference from the blank is 0.005 to less than 0.011;
(Triangle | delta): The difference with a blank is 0.011-0.020 or less;
X: The difference with a blank exceeds 0.020;
It was.

[Fixability]
A fixing belt of an electrophotographic copying machine (IPSiOCX8800, manufactured by Ricoh Co., Ltd.) using a Teflon (registered trademark) roller as a fixing roller is used to change the temperature of the fixing belt, A solid image having a toner adhesion amount of 0.85 ± 0.1 mg / cm ² was formed on a thick transfer paper type 6200 (manufactured by Ricoh Co., Ltd.) and copy printing paper <135> (manufactured by NBS Ricoh Co., Ltd.). At this time, the upper limit temperature at which hot offset does not occur on plain paper was taken as the fixing upper limit temperature. Further, the lower limit temperature at which the residual ratio of the image density after rubbing the solid image with a pad was 70% or more was defined as the minimum fixing temperature.

(Evaluation criteria for maximum fixing temperature)
A: Fixing upper limit temperature is 190 ° C. or higher;
○: The fixing upper limit temperature is 180 ° C. or higher and lower than 190 ° C .;
Δ: Fixing upper limit temperature is 170 ° C. or higher and lower than 180 ° C .;
×: Fixing upper limit temperature is less than 170 ° C .;
It was.

(Evaluation criteria for minimum fixing temperature)
A: Fixing lower limit temperature is less than 115 ° C .;
○: Fixing lower limit temperature is 115 ° C. or higher and lower than 125 ° C .;
Δ: Fixing lower limit temperature is 125 ° C. or higher and lower than 155 ° C .;
X: The fixing lower limit temperature is 155 ° C. or higher;
It was.

DESCRIPTION OF SYMBOLS 1 Particle production apparatus 2 Particle production apparatus 11, 21 Cell 31, 41 Cylinder 12, 22, 32, 42 Pump 13, 23, 33, 43 Valve 16, 46 Back pressure valve 38, 48 Heater 14, 15 Mixing apparatus 17 Nozzle T Toner

JP-A-9-34167

Claims (11)

A method for producing a toner comprising a binder resin containing a pressure plastic material and a release agent,
A mixing step of continuously forming the mixture by continuously supplying and joining the pressure plastic material and the release agent, and continuously supplying to the next step;
A melting step of contacting the first compressive fluid and the mixture to melt the mixture;
A granulation step of spraying and granulating the melt obtained in the melting step;
A method for producing a toner comprising: The granulation step includes a step of supplying a second compressive fluid to the melt.
The method for producing a toner according to claim 1.   The toner manufacturing method according to claim 1, wherein the second compressive fluid includes nitrogen. The toner contains 1% by mass or more of the release agent;
The toner according to claim 1. The pressure plastic material includes a resin having a carbonyl structure.
The method for producing a toner according to claim 1. The pressure plastic material includes a crystalline resin,
The method for producing a toner according to claim 1.   The method for producing a toner according to claim 1, wherein the melt has a viscosity of 500 mPa · s or less.   The method for producing a toner according to claim 1, wherein the first compressive fluid includes carbon dioxide.   The toner manufacturing method according to claim 1, wherein no organic solvent is used.   A toner comprising a plurality of the particulate release agents produced by the toner production method according to claim 1. A method for producing particles in which a sea-island structure is formed by a pressure plastic material that forms a sea phase and a plurality of dispersed particles that form an island phase,
A mixing step of continuously forming the mixture by continuously supplying and merging the pressure plastic material and the dispersed particles, and continuously supplying to the next step;
A melting step of contacting the first compressive fluid and the mixture to melt the mixture;
A granulation step of spraying and granulating the melt obtained in the melting step;
A method for producing particles having