JP2009258538A - Toner for electrostatic charge image development and method of manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a toner for electrostatic charge image development, which achieves low-temperature fixing, has superior heat-resistant storage properties, can obtain print images free from image defects such as hollow transfer, and irregular density occurring at a halftone section, even if many sheets are printed, and prevents odors from occurring at the time of heat fixing; and to provide a method of producing the same. <P>SOLUTION: The toner for electrostatic charge image development contains a resin prepared by copolymerizing a polymerizable monomer containing a compound expressed by general formula (1) In the toner, the composition ratio of the compound expressed by general formula (1) to the resin is 20 to 45 mass%; the volatilized amount of the compound expressed by general formula (1) is 1 to 500 ppm with respect to the toner for electrostatic charge image development; the toner contains a compound of 1 to 1,000 ppm, the compound being selected from aromatic carboxylic acid, aliphatic carboxylic acid and aliphatic alcohol; and the glass transition temperature of the toner is 20 to 40°C. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an electrostatic image developing toner and a method for producing the same.

In recent years, vigorous research has been carried out to reduce power consumption when a printer or a copier is moving. In addition, with the increasing use of printers in offices due to the penetration of the Internet environment, and the expansion of usage opportunities in offices and homes in various forms due to the trend of the times such as home use of digital devices such as printers and facsimiles Reducing low-grade power and power costs is an inevitable issue. Therefore, printers and copiers are required to achieve low temperature fixing by reducing the heat and energy required for fixing to achieve the problem. As an example, a technique is disclosed in which a fixed image can be formed at a lower temperature than conventional by containing a low-melting wax or lowering the glass transition point of a resin forming a toner ( For example, see Patent Document 1).
JP 2001-42564 A (wax)

  In order to enable low-temperature fixing, generally, the glass transition point of the resin forming the toner is lowered to cope with it.

  In order to lower the glass transition point, it is necessary to increase the amount of a polymerizable monomer (hereinafter also referred to as a monomer) having a low glass transition point as represented by the general formula (1). Is low in polymerization reactivity and tends to remain (residual) in the toner particles as an unreacted monomer during polymerization. As a result, the unreacted residual monomer acts as a plasticizer, causing the toner particles to block during storage, causing problems, and causing toner agglomerates in the developing device, resulting in image defects and the like. It was.

  In addition, when a resin having a wide molecular weight distribution is used, there is a problem in that it is difficult to melt partially and causes fixing failure.

  The present invention has been made in view of the above problems, and the object of the present invention is to enable low-temperature fixing, excellent heat-resistant storage, and image defects such as transfer omission and uneven density of halftone portions even when a large number of sheets are printed. It is an object of the present invention to provide a toner for developing an electrostatic image and a method for producing the same, in which a print image free from odor is obtained and no odor is generated during heat fixing.

  The above object of the present invention is achieved by the following configurations.

1.
In the electrostatic image developing toner having a resin obtained by copolymerizing a polymerizable monomer containing a compound represented by the following general formula (1):
The compound represented by the general formula (1) is 20 to 45% by mass with respect to the resin in a composition ratio,
The amount of volatilization of the compound represented by the general formula (1) is 1 to 500 ppm with respect to the electrostatic image developing toner,
Containing 1-1000 ppm of a compound selected from aromatic carboxylic acid, aliphatic carboxylic acid, aliphatic alcohol,
A toner for developing an electrostatic charge image, having a glass transition point of 20 to 45 ° C.

Formula _{(1) H 3 C = CR} 1 -COOR 2
(In the formula, R ₁ represents H or CH ₃ , and R ₂ represents a long-chain alkyl group having 3 to 22 carbon atoms or a cyclic alkyl group.)
2.
2. The electrostatic image developing toner according to 1, wherein the resin has a weight average molecular weight (Mw) of 10,000 to 50,000 and Mw / Mn of 1.5 to 4.

3.
Electrostatic charge image development comprising a step of copolymerizing a polymerizable monomer containing a compound represented by the following general formula (1) to polymerize resin particles, and a step of aggregating and fusing the resin particles and colorant particles In the manufacturing method of the toner,
In the polymerization step, n polymerization reactions are performed (where n is an integer of 2 or more)
The polymerization initiator is added in two or more portions,
A method for producing an electrostatic charge image developing toner, comprising adding an oil-soluble polymerization initiator at a later stage of the n-th polymerization reaction.

Formula _{(1) H 3 C = CR} 1 -COOR 2
(In the formula, R ₁ represents H or CH ₃ , and R ₂ represents a long-chain alkyl group having 3 to 22 carbon atoms or a cyclic alkyl group.)

  The electrostatic image developing toner of the present invention and the method for producing the same are capable of low-temperature fixing, excellent heat-resistant storage stability, and print images free from image defects such as transfer omission and uneven density in halftone areas even after printing many sheets. As well as an excellent effect that no odor is generated during heat fixing.

  The inventors of the present invention are capable of low-temperature fixing, have excellent heat-resistant storage properties, and can obtain a printed image having no image defects such as transfer omission and uneven density in a halftone portion even when a large number of sheets are printed. An excellent electrostatic charge image developing toner (hereinafter, also simply referred to as “toner”) that does not generate toner was studied.

  As a result of various studies, it has been found that an electrostatic image developing toner having a resin obtained by copolymerizing a polymerizable monomer containing a compound having a specific structure can achieve the object of the present invention.

Specifically, the toner of the present invention contains a resin obtained by copolymerizing a polymerizable monomer containing a compound represented by the following general formula (1),
The compound represented by the general formula (1) is 20 to 45% by mass with respect to the resin in a composition ratio,
The volatilization amount of the compound represented by the general formula (1) is 1 to 500 ppm with respect to the toner,
It contains 1 to 1000 ppm of a compound selected from aromatic carboxylic acid, aliphatic carboxylic acid and aliphatic alcohol, and has a glass transition point of 20 to 45 ° C.

Formula _{(1) H 3 C = CR} 1 -COOR 2
(In the formula, R ₁ represents H or CH ₃ , and R ₂ represents a long-chain alkyl group having 3 to 22 carbon atoms or a cyclic alkyl group.)
Hereinafter, the present invention will be described in detail.

[Technical idea of the present invention]
In order to obtain a toner that can be fixed at low temperature, it is necessary to lower the glass transition point (hereinafter also referred to as Tg) of the toner. For that purpose, a large amount of polymerizable monomer capable of lowering Tg as represented by the general formula (1) must be used.

  However, since the compound represented by the general formula (1) has lower polymerization reactivity than styrene, it tends to remain in the toner particles as an unreacted monomer during polymerization.

  Furthermore, the compound represented by the general formula (1) has a strong odor, and if it remains in a large amount in the toner particles, it is vaporized by heating at the time of fixing, and an odor is generated.

  Further, if a large amount of the compound represented by the general formula (1) remains in the toner particles, a plasticizer effect is brought about on the toner. The plasticizer effect here is advantageous for low-temperature fixability because the toner melts at a lower temperature, but the heat-resistant storage stability is reduced and the toner particles tend to aggregate during storage, resulting in a lower temperature. It is necessary to store in Further, toner agglomerates may occur in the developing device, which may cause image defects.

  In the present invention, the amount of the general formula (1) remaining in the toner particles when a toner is produced from a resin obtained by polymerization using a compound that lowers the Tg as represented by the general formula (1). It has been found that the problem of low-temperature fixability, odor and heat-resistant storage stability can be solved by setting the toner to 1 to 500 ppm with respect to the total mass of the toner.

  The inventors of the present application have found that the toner in which the amount of the general formula (1) remaining in the toner particles is 1 to 500 ppm with respect to the total mass of the toner is a polymerization added at the initial stage of polymerization in a multistage polymerization reaction After the initiator is consumed in a multistage reaction, in other words, by adding an oil-soluble polymerization initiator at the latter stage of the polymerization reaction, the polymerization reaction of the compound represented by the general formula (1) having low reactivity It was found that the remaining amount of the unreacted compound represented by the general formula (1) remaining in the toner can be reduced.

  That is, after adding the oil-soluble polymerization initiator, the polymerization reaction by the added polymerization initiator is newly started by keeping the temperature for a certain time, and the reaction of the polymerizable monomer remaining in the reaction system Is promoted. Furthermore, after adding an oil-soluble polymerization initiator, by raising the polymerization temperature, all of the polymerization initiator remaining in the system is decomposed and the polymerization initiator is rapidly decomposed. Furthermore, the reaction of the unreacted monomer can be promoted.

  Further, in order to promote the lowering of Tg, it is necessary to set the molecular weight low, and a method of increasing the amount of the polymerization initiator as compared with the conventional method is adopted. However, in this method, the polymerization reaction is promoted and the oligomer (2 amounts) is used. The amount of low molecular weight components such as isomers and trimers) also increases, which adversely affects heat-resistant storage properties. For this reason, while suppressing the total amount of polymerization initiator, after the polymerization initiator added in the initial stage of polymerization has been sufficiently consumed, the polymerization can proceed in a desirable state by adding an additional (oil-soluble) polymerization initiator. It becomes possible.

  First, terms used in the present invention will be described.

  The toner in the present invention is a general term for toner particles. Toner particles are particles obtained by adding an external additive to colored particles. The colored particles are particles obtained by aggregating and fusing resin particles and colorant particles.

  Next, the compound represented by the general formula (1) will be described.

<< Compound Represented by Formula (1) >>
The compound represented by the general formula (1) used in the present invention is a compound represented by the following formula.

Formula _{(1) H 3 C = CR} 1 -COOR 2
(In the formula, R ₁ represents H or CH ₃ , and R ₂ represents a long-chain alkyl group having 3 to 22 carbon atoms or a cyclic alkyl group.)
Specific compounds include propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, t-butyl methacrylate, isobutyl methacrylate, n-octyl methacrylate, 2-ethylhexyl methacrylate, lauryl methacrylate, propyl acrylate , Isopropyl acrylate, n-butyl acrylate, t-butyl acrylate, isobutyl acrylate, n-octyl acrylate, 2-ethylhexyl acrylate, and lauryl acrylate. Among these, isopropyl acrylate, n-butyl acrylate, 2-ethylhexyl acrylate, and lauryl acrylate are preferable.

<< Composition ratio of compound represented by general formula (1) to resin >>
The composition ratio of the compound represented by the general formula (1) to the resin is 20 to 45% by mass, preferably 20 to 30% by mass. By setting the composition ratio to 20% by mass or more, low-temperature fixability can be secured, and by setting it to 45% by mass or less, heat-resistant storage stability can be secured.

<< Volatilization amount of the compound represented by the general formula (1) >>
In the toner of the present invention, the volatilization amount of the compound represented by the general formula (1) is 1 to 500 ppm, preferably 10 to 400 ppm, based on the total mass of the toner.

  By setting the volatilization amount of the compound represented by the general formula (1) to 1 ppm or more, a toner can be produced with high productivity, and the generation of odor can be suppressed by heating during fixing.

  By setting it to 500 ppm or less, it is possible to prevent the generation of odor and toner aggregation in the developing device by heating at the time of fixing, and to secure the heat-resistant storage property of the toner.

(Quantification method for volatilization)
The volatilization amount of the compound represented by the general formula (1) can be quantified by headspace gas chromatography.

  In the headspace gas chromatography method, toner is sealed in a container, heated to a heat fixing temperature of the image forming apparatus (for example, 170 ° C.), and the gas in the container is quickly discharged while the container is full of volatile components. It is injected into a gas chromatograph, and volatile components are quantified while performing mass spectrometry and identifying the compound.

  As a method for measuring impurities derived from resins and trace amounts of additives, a method in which a resin or toner is dissolved in a solvent and injected into a gas chromatograph is well known. It is preferable to apply the above-mentioned headspace method in order to measure the total amount of volatile components because the peak of a small amount of additive component to be hidden may be hidden. In the headspace method, all peaks of volatile components can be observed by gas chromatograph, and analysis methods using electromagnetic interaction are used to quantify volatile substances and monomers with high accuracy. Can also be performed.

(Measurement condition)
1. Sample collection A 0.8 g sample is collected in a 20 ml headspace vial. Since the amount of the sample is necessary to calculate the area per mass, it is weighed to 0.01 g. Seal the headspace vial with a dedicated crimper.

2. Heating the sample Place the headspace vial in a 170 ° C constant temperature bath and heat for 30 minutes.

3. Setting of Gas Chromatographic Separation Conditions A column coated with a silicone oil SE-30 coated with silicone oil SE-30 so as to have a mass ratio of 15% is packed in a column having an inner diameter of 2.5 mm and a length of 30 m is used as a separation column. The separation column is equipped with a gas chromatograph, and He is used as a carrier to flow at 50 ml / min. The temperature of the separation column is set at 40 ° C. and held for 3 minutes, and then the temperature is raised to 200 ° C. at 10 ° C./min.

4). Sample injection Remove the vial from the thermostat and immediately inject 1 ml with a gas tight syringe.

5. Calculation Monomer quantification is calculated using a calibration curve prepared in advance for each monomer.

  6). The following configuration is preferable as the apparatus.

(A) Headspace conditions Headspace device: HP7694 Head Space Sampler (manufactured by Hewlett-Packard Company)
Temperature conditions: transfer line 200 ° C, loop temperature 200 ° C
Sample amount: 0.8 g / 20 ml vial (b) GC / MS conditions GC: HP5890 (manufactured by Hewlett-Packard Company)
MS: HP5971 (manufactured by Hewlett-Packard Company)
Column: HP-624 (30 m x inner diameter 0.25 mm)
Oven temperature: initial temperature 40 ° C. (holding time 3 minutes), heating rate 10 ° C./min, ultimate temperature 200 ° C. (holding time 5 minutes)
Measurement mode: SIM (select ion monitor) mode Specific examples of volatile substances quantified by headspace gas chromatography include monomers styrene, o-methylstyrene, acrylic acid, methacrylic acid, ethyl acrylate, acrylic acid Examples include butyl, a crosslinkable monomer, n-octyl mercaptan, n-decyl mercaptan, and the like.
<< Compound selected from aromatic carboxylic acid, aliphatic carboxylic acid, aliphatic alcohol >>
The toner of the present invention is characterized by containing 1 to 1000 ppm, preferably 10 to 600 ppm of a compound selected from aromatic carboxylic acid, aliphatic carboxylic acid, and aliphatic alcohol.

  By containing 1 to 1000 ppm of a compound selected from an aromatic carboxylic acid, an aliphatic carboxylic acid, and an aliphatic alcohol, an effect of odor during heat fixing can be recognized.

  The content of the compound selected from aromatic carboxylic acid, aliphatic carboxylic acid and aliphatic alcohol can be controlled by the kind and amount of the oil-soluble polymerization initiator added additionally.

(Quantification method of content)
The content of a compound selected from an aromatic carboxylic acid, an aliphatic carboxylic acid, and an aliphatic alcohol can be quantified by the same quantification method as the volatilization amount of the compound represented by the general formula (1).

<Glass transition point of toner>
The toner of the present invention has a glass transition point (Tg) of 20 to 45 ° C, preferably 25 to 40 ° C. When Tg is 20 ° C. or higher, heat-resistant storage stability can be secured, and when Tg is 45 ° C. or lower, low-temperature fixability can be secured.

  In order to make Tg into the range of 20-45 degreeC, the kind and quantity of the monomer which form copolymer resin are adjusted. Propyl acrylate, propyl methacrylate, butyl acrylate, 2-ethylhexyl acrylate, lauryl acrylate, and the like are monomers that lower Tg, and styrene, methyl methacrylate, methacrylic acid, and the like are monomers that increase Tg.

(Measurement method of Tg)
Tg can be measured by a differential scanning calorimetry method, for example, using a DSC-7 differential scanning calorimeter (Perkin Elmer) or a TAC7 / DX thermal analyzer controller (Perkin Elmer).

  As a measurement procedure, toner 4.5 to 5.0 mg is precisely weighed to 0.01 mg, sealed in an aluminum pan (KITNO.0219-0041), and set in a DSC-7 sample holder. The reference used an empty aluminum pan. As measurement conditions, the measurement temperature is 0 to 200 ° C., the temperature increase rate is 10 ° C./min, the temperature decrease rate is 10 ° C./min, and the heat-cool-heat control is performed, and the analysis is performed based on the data in the 2nd Heat. went.

  Tg draws an extension line of the baseline before the rise of the first endothermic peak and a tangent line indicating the maximum inclination between the rising portion of the first endothermic peak and the peak apex, and the intersection is defined as Tg.

<Molecular weight of resin, polymerization ratio>
The resin constituting the toner of the present invention preferably has a weight average molecular weight (Mw) of 10,000 to 50,000 and Mw / Mn of 2 to 4.

  A resin having a weight average molecular weight (Mw) and Mw / Mn in the above ranges can be prepared by appropriately selecting the type and amount of the polymerizable monomer (monomer) and the amount and type of the polymerization initiator.

  By using a resin having a weight average molecular weight (Mw) of 10,000 or more, heat-resistant storage stability can be secured, and by using a resin having a weight average molecular weight of 50,000 or less, low-temperature fixability can be secured. Further, when the molecular weight distribution (Mw / Mn) is 4 or less, it is not difficult to melt partially, and no fixing failure is caused. When it is 2 or more, low temperature fixability can be secured.

(Measurement of molecular weight)
The molecular weight of the resin can be measured using a gel permeation chromatograph (GPC).

  As a method for measuring the molecular weight of the resin by GPC, a sample (toner) is dissolved in tetrahydrofuran so as to be 1 mg / ml. As dissolution conditions, it is carried out at room temperature for 5 minutes using an ultrasonic disperser. Next, after processing with a membrane filter having a pore size of 0.2 μm, 10 μl of sample solution is injected into GPC.

  The measurement conditions for GPC are shown below.

Apparatus: HLC-8220 (manufactured by Tosoh Corporation)
Column: TSKguardcolum + TSKgelSuperHZM-M 3 series (manufactured by Tosoh Corporation)
Column temperature: 40 ° C
Solvent: Tetrahydrofuran Flow rate: 0.2 ml / min Detector: Refractive index detector (RI detector)
In the measurement of the molecular weight of a sample, the molecular weight distribution of the sample is calculated using a calibration curve measured using monodisperse polystyrene standard particles. Ten polystyrenes for calibration curve measurement were used.

(Measurement of polymerization rate (Mw / Mn))
The polymerization rate was calculated based on the area ratio of around Mw = 500 in the GPC measurement chart.

  Specifically, a part of the polymerization reaction solution was collected, immediately after solid-liquid separation and dried, and the polymerization rate of the collected resin was calculated by the following formula in the same measurement method as the molecular weight of the resin.

  Polymerization rate = (total peak area of Mw = 500 or more) / (total peak area of Mw = 500 or less) Note that the peak of Mw = 500 or less does not include a solvent peak.

<Material used to form toner>
Materials used for forming the toner of the present invention include polymerizable monomer colorants other than the compound represented by the general formula (1), wax (hereinafter also referred to as mold release agent), polymerization initiator, chain Examples thereof include a transfer agent, a dispersion stabilizer, and a surfactant.

(Polymerizable monomer other than the compound represented by the general formula (1))
Examples of polymerizable monomers (monomers) other than the compound represented by the general formula (1) include styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, α-methylstyrene, p-chlorostyrene, 3,4-dichlorostyrene, p-phenylstyrene, p-ethylstyrene, 2,4-dimethylstyrene, p-tert-butylstyrene, pn-hexylstyrene, pn-octylstyrene, pn-nonyl Styrene such as styrene, pn-decylstyrene, pn-dodecylstyrene, or styrene derivatives, methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, isopropyl methacrylate, isobutyl methacrylate, t-butyl methacrylate, N-octyl methacrylate, 2-ethylhexyl methacrylate, methacryl Stearyl, lauryl methacrylate, phenyl methacrylate, diethylaminoethyl methacrylate, methacrylic acid ester derivatives such as dimethylaminoethyl methacrylate, acrylic acid ester derivatives such as stearyl acrylate and phenyl acrylate, and olefins such as ethylene, propylene, and isobutylene , Vinyl halides such as vinyl chloride, vinylidene chloride, vinyl bromide, vinyl fluoride, vinylidene fluoride, vinyl esters such as vinyl propionate, vinyl acetate, vinyl benzoate, vinyl methyl ether, vinyl ethyl ether, etc. N-vinylation of vinyl ethers, vinyl ketones such as vinyl methyl ketone, vinyl ethyl ketone, vinyl hexyl ketone, N-vinyl carbazole, N-vinyl indole, N-vinyl pyrrolidone, etc. Examples thereof include vinyl compounds such as compounds, vinyl naphthalene and vinyl pyridine, and acrylic acid or methacrylic acid derivatives such as acrylonitrile, methacrylonitrile and acrylamide. These vinyl monomers can be used alone or in combination.

  Further, it is more preferable to use a combination of monomers having an ionic dissociation group as the polymerizable monomer constituting the resin. For example, it has a substituent such as a carboxyl group, a sulfonic acid group, a phosphoric acid group as a constituent group of the monomer, specifically, acrylic acid, methacrylic acid, maleic acid, itaconic acid, cinnamic acid, fumar Acid, maleic acid monoalkyl ester, itaconic acid monoalkyl ester, styrene sulfonic acid, allyl sulfosuccinic acid, 2-acrylamido-2-methylpropane sulfonic acid, acid phosphooxyethyl methacrylate, 3-chloro-2-acid phosphooxy And propyl methacrylate.

  Furthermore, multifunctional such as divinylbenzene, ethylene glycol dimethacrylate, ethylene glycol diacrylate, diethylene glycol dimethacrylate, diethylene glycol diacrylate, triethylene glycol dimethacrylate, triethylene glycol diacrylate, neopentyl glycol dimethacrylate, neopentyl glycol diacrylate, etc. It is also possible to use a crosslinkable resin by using a functional vinyl.

(Coloring agent)
As the colorant, carbon black, a magnetic material, a dye, a pigment, and the like can be arbitrarily used. As the carbon black, channel black, furnace black, acetylene black, thermal black, lamp black, and the like are used. Magnetic materials include ferromagnetic metals such as iron, nickel and cobalt, alloys containing these metals, compounds of ferromagnetic metals such as ferrite and magnetite, alloys that do not contain ferromagnetic metals but exhibit ferromagnetism by heat treatment, For example, a kind of alloy called Heusler alloy such as manganese-copper-aluminum, manganese-copper-tin, chromium dioxide, or the like can be used.

  Examples of the dye include C.I. I. Solvent Red 1, 49, 52, 58, 63, 111, 122, C.I. I. Solvent Yellow 19, 44, 77, 79, 81, 82, 93, 98, 103, 104, 112, 162, C.I. I. Solvent Blue 25, 36, 60, 70, 93, 95, etc. can be used, and mixtures thereof can also be used. Examples of the pigment include C.I. I. Pigment Red 5, 48: 1, 53: 1, 57: 1, 122, 139, 144, 149, 166, 177, 178, 222, C.I. I. Pigment Orange 31 and 43, C.I. I. Pigment Yellow 14, 17, 74, 93, 94, 138, 156, 158, 180, 185, C.I. I. Pigment green 7, C.I. I. Pigment Blue 15: 3, 60, etc. can be used, and a mixture thereof can also be used. The number average primary particle size varies depending on the type, but is preferably about 10 to 200 nm.

  As a method for adding a colorant, the polymer particles are colored by adding resin particles at the stage of agglomeration by addition of a flocculant. The colorant can be used by treating the surface with a coupling agent or the like.

(wax)
A conventionally well-known thing can be used as a wax. Specifically, polyolefin waxes such as polyethylene wax and polypropylene wax, long chain hydrocarbon waxes such as paraffin wax and sazol wax, dialkyl ketone waxes such as distearyl ketone, carnauba wax, montan wax, trimethylolpropane. Tribehenate, pentaerythritol tetramyristate, pentaerythritol tetrastearate, pentaerythritol tetrabehenate, pentaerythritol diacetate dibehenate, glycerin tribehenate, 1,18-octadecanediol distearate, trimellit Ester waxes such as acid tristearyl and distearyl maleate, amides such as ethylenediamine dibehenyl amide and trimellitic acid tristearyl amide Box, and the like.

  The melting point of the wax is usually 40 to 160 ° C, preferably 50 to 120 ° C, more preferably 60 to 90 ° C. By setting the melting point within the above range, the heat-resistant storage stability of the toner is ensured, and stable toner image formation can be performed without causing cold offset or the like even when fixing at a low temperature. Further, the wax content in the toner particles is preferably 1 to 30% by mass, more preferably 5 to 20% by mass.

  Next, a polymerization initiator, a chain transfer agent, and a surfactant will be described.

(Polymerization initiator)
As the polymerization initiator, a water-soluble polymerization initiator and an oil-soluble polymerization initiator are used.

  Examples of the water-soluble polymerization initiator include persulfates such as potassium persulfate and ammonium persulfate, azobisaminodipropane acetate, azobiscyanovaleric acid and its salts, hydrogen peroxide and the like.

  Examples of oil-soluble polymerization initiators include 2,2′-azobis- (2,4-dimethylvaleronitrile), 2,2′-azobisisobutyronitrile, 1,1′-azobis (cyclohexane-1-carbohydrate). Nitriles), 2,2'-azobis-4-methoxy-2,4-dimethylvaleronitrile, azo- or diazo-based polymerization initiators such as azobisisobutyronitrile, benzoyl peroxide, methyl ethyl ketone peroxide, diisopropyl peroxycarbonate , Cumene hydroperoxide, t-butyl hydroperoxide, di-t-butyl peroxide, dicumyl peroxide, 2,4-dichlorobenzoyl peroxide, lauroyl peroxide, 2,2-bis- (4,4- t-butylperoxycyclohexyl) propane, tris- ( - butyl peroxy) peroxide polymerization initiator or a peroxide such as triazine can be mentioned polymeric initiators having a side chain.

(Chain transfer agent)
In the present invention, a chain transfer agent can be used for the purpose of adjusting the molecular weight of the resin.

  The chain transfer agent is not particularly limited, and examples thereof include mercaptans such as octyl mercaptan, dodecyl mercaptan, tert-dodecyl mercaptan, n-octyl-3-mercaptopropionate, terpinolene, carbon tetrabromide and α-methyl. A styrene dimer etc. can be mentioned.

(Dispersion stabilizer)
In addition, a dispersion stabilizer can be used in order to appropriately disperse the polymerizable monomer and the like in the reaction system. Dispersion stabilizers include tricalcium phosphate, magnesium phosphate, zinc phosphate, aluminum phosphate, calcium carbonate, magnesium carbonate, calcium hydroxide, magnesium hydroxide, aluminum hydroxide, calcium metasilicate, calcium sulfate, barium sulfate , Bentonite, silica, alumina and the like. Furthermore, those generally used as surfactants such as polyvinyl alcohol, gelatin, methylcellulose, sodium dodecylbenzenesulfonate, ethylene oxide adduct, and higher alcohol sodium sulfate can be used as the dispersion stabilizer.

(Surfactant)
Next, the surfactant will be described.

  In order to perform polymerization using the above-described polymerizable monomer, it is necessary to disperse oil droplets in an aqueous medium using a surfactant. Although it does not specifically limit as surfactant which can be used in this case, The following ionic surfactant can be mentioned as an example of a suitable thing.

  Examples of the ionic surfactant include sulfonates (sodium dodecylbenzenesulfonate, sodium arylalkylpolyethersulfonate, 3,3-disulfonediphenylurea-4,4-diazobis-amino-8-naphthol-6-sulfonic acid). Sodium, ortho-carboxybenzene-azodimethylaniline, 2,2,5,5-tetramethyl-triphenylmethane-4,4-diazo-bis-β-naphthol-6-sulfonic acid sodium salt), sulfate ester salt ( Sodium dodecyl sulfate, sodium tetradecyl sulfate, sodium pentadecyl sulfate, sodium octyl sulfate, etc., fatty acid salts (sodium oleate, sodium laurate, sodium caprate, sodium caprylate, sodium caproate, stearic acid) Potassium, calcium oleate and the like).

  Nonionic surfactants can also be used. Specifically, polyethylene oxide, polypropylene oxide, combination of polypropylene oxide and polyethylene oxide, ester of polyethylene glycol and higher fatty acid, alkylphenol polyethylene oxide, ester of higher fatty acid and polyethylene glycol, ester of higher fatty acid and polypropylene oxide, sorbitan ester Etc.

<Method for producing toner>
Next, a toner manufacturing method will be described.

  The toner production method includes a step of copolymerizing a polymerizable monomer containing the compound represented by the general formula (1) to form resin particles, and a step of aggregating and fusing the resin particles and colorant particles. Have

  The toner production method according to the present invention is characterized in that after the polymerization initiator is added in the step of forming the resin particles, the polymerization reaction is allowed to proceed at least twice, and an additional oil-soluble polymerization initiator is added later in the polymerization. To complete the polymerization.

  As described above, after the polymerization initiator added at the initial stage of the polymerization is sufficiently consumed, the remaining polymerizable monomer can be reduced by adding an oil-soluble polymerization initiator additionally.

  Furthermore, even after the addition of an oil-soluble polymerization initiator, the polymerization is carried out gently by keeping the temperature for a certain period of time, and then the polymerization initiator remaining in the system is removed by raising the temperature. All of them are decomposed, and it is possible to further promote the reaction of unreacted monomers by rapidly decomposing the polymerization initiator.

  If the amount of the polymerization initiator is made as usual, polymerization at the oligomer level is promoted, and as a result, the heat resistant storage stability is adversely affected. For this reason, it is possible to proceed in a desired state by adding an additional polymerization initiator after the polymerization initiator added in the initial stage of polymerization is sufficiently consumed while suppressing the total amount of polymerization initiator.

  The polymerization rate can be calculated by the method described above (measurement of the polymerization rate).

  Hereinafter, a toner production method will be described by taking multilayer resin particles (core / shell structured particles) as an example.

Specifically, it can be produced through the following steps.
(1) Dissolution / dispersion step of dissolving or dispersing the release agent in the polymerizable monomer (2) Polymerization step of polymerizing the polymerizable monomer to produce a dispersion of resin particles (3) In an aqueous medium Aggregation / fusion process for aggregating and fusing resin particles and colorant particles to obtain core particles (association particles) (4) First aging process (5) for adjusting the shape by aging the core particles with thermal energy Shell forming step in which colored particles having a core / shell structure are formed by adding resin particles for the shell to the core particle dispersion and aggregating and fusing the shell particles on the surface of the core particles (6) Core / shell structure A second aging step for adjusting the shape of the colored particles having a core / shell structure by aging the colored particles with thermal energy (7) The colored particles are separated from the cooled colored particle dispersion by solid-liquid separation. Cleaning process to remove surfactants from the surface (8) Cleaning process And drying process of drying the colored particle also after the drying step if necessary,
(9) Step of adding an external additive to the dried colored particles Each step will be described below.

(1) Dissolution / dispersion step This step is a step of preparing a radical polymerizable monomer solution in which a release agent compound is dissolved in a radical polymerizable monomer and the release agent compound is mixed.

(2) Polymerization step In a preferred example of this polymerization step, a radical polymerizable monomer solution in which a wax is dissolved or dispersed in an aqueous medium containing a surfactant having a critical micelle concentration (CMC) or less is added. Then, mechanical energy is applied to form droplets, and then a water-soluble polymerization initiator is added. After the water-soluble polymerization initiator added at the initial stage of the polymerization is sufficiently consumed, an oil-soluble polymerization initiator is added. Additional additions allow the polymerization to proceed in the desired state.

  In such a polymerization process, mechanical energy is imparted and forcedly emulsified (formation of droplets) is essential. Examples of the mechanical energy applying means include strong stirring such as homomixer, ultrasonic wave, and manton gorin, or ultrasonic vibration energy applying means.

  By this polymerization step, resin particles containing a wax and a binder resin are obtained. Such resin particles may be colored fine particles or non-colored fine particles. The colored resin particles can be obtained by polymerizing a monomer composition containing a colorant. In addition, when using uncolored resin particles, the dispersion of the colorant particles is added to the dispersion of the resin particles in the aggregation / fusion process described later to melt the resin particles and the colorant particles. Color particles can be obtained by attaching.

  The polymerization temperature may be any temperature as long as it is equal to or higher than the lowest radical generation temperature of the polymerization initiator, but for example, a range of 50 to 90 ° C. is used. However, it is also possible to perform polymerization at room temperature or higher by using a polymerization initiator that starts at room temperature, for example, a combination of hydrogen peroxide and a reducing agent (ascorbic acid).

  Since the polymerizable monomer represented by the general formula (1) generally has low reactivity and is likely to remain unreacted in the reaction system, the addition of a polymerization initiator during this polymerization step It can be controlled by the method.

  In order to reduce the unreacted polymerizable monomer, an oil-soluble polymerization initiator is added at a later stage of polymerization. The amount added is preferably 10% by mass or more of the total amount of the polymerization initiator.

  Furthermore, in order to accelerate the polymerization reaction of the unreacted compound represented by the general formula (1), it is preferable to increase the temperature after adding an oil-soluble polymerization initiator.

  By passing through the said process, the volatilization amount of the compound represented by General formula (1) can be controlled to 1-500 ppm with respect to a toner.

  The compound selected from aromatic carboxylic acid, aliphatic carboxylic acid, and aliphatic alcohol can be controlled to 1 to 1000 ppm depending on the amount and type of the oil-soluble polymerization initiator.

(3) Aggregation / fusion process As a method of aggregation / fusion, a salting out / fusion method using resin particles (colored or non-colored resin particles) obtained by the polymerization process is preferable. Further, in the aggregation / fusion process, the resin particles and the colorant particles can be aggregated / fused together with the fine particles of the internal additive such as wax fine particles and charge control agent.

  In this case, “salting out / fusion” means that aggregation and fusion are advanced in parallel, and when the particles grow to a desired particle size, an aggregation terminator is added to stop the particle growth, and further necessary. The heating for controlling the particle shape according to the above is performed continuously.

  The “aqueous medium” in the agglomeration / fusion step is one in which the main component (50% by mass or more) is made of water. Examples of components other than water include organic solvents that dissolve in water, such as methanol, ethanol, isopropanol, butanol, acetone, methyl ethyl ketone, and tetrahydrofuran.

  The colorant particles can be produced by dispersing the colorant in an aqueous medium. The dispersion treatment of the colorant is performed in a state where the surfactant concentration is set to a critical micelle concentration (CMC) or more in water. The disperser used for the dispersion treatment of the colorant is not particularly limited, but preferably an ultrasonic disperser, a mechanical homogenizer, a pressure disperser such as a manton gorin or a pressure homogenizer, a sand grinder, a Getzmann mill, a diamond fine mill, or the like. A medium type disperser is mentioned. Examples of the surfactant used include the same surfactants as those described above. The colorant (fine particles) may be surface-modified. In the surface modification method of the colorant, the colorant is dispersed in a solvent, the surface modifier is added to the dispersion, and the system is reacted by raising the temperature. After completion of the reaction, the colorant is separated by filtration, washed and filtered with the same solvent, and dried to obtain a colorant (pigment) treated with the surface modifier.

  The salting-out / fusion method, which is a preferred agglomeration / fusion method, is a salting-out method comprising alkali metal salt, alkaline earth metal salt, trivalent salt, etc. in water in which resin particles and colorant particles are present The agent is added as an aggregating agent having a critical agglomeration concentration or higher, and then the salting-out proceeds by heating to a temperature higher than the glass transition point of the resin particles and higher than the melting peak temperature of the mixture. It is a process to be performed. Here, the alkali metal salt and alkaline earth metal salt which are salting-out agents include lithium, potassium, sodium and the like as the alkali metal, and magnesium, calcium, strontium, barium and the like as the alkaline earth metal. Preferably, potassium, sodium, magnesium, calcium, and barium are used.

  When agglomeration and fusion are performed by salting out / fusion, it is preferable to make the time allowed to stand after adding the salting-out agent as short as possible. The reason for this is not clear, but there is a problem that the aggregation state of the particles varies depending on the standing time after salting out, the particle size distribution becomes unstable, and the surface property of the fused toner varies. appear. The temperature for adding the salting-out agent needs to be at least the glass transition point of the resin particles. The reason for this is that if the temperature at which the salting-out agent is added is equal to or higher than the glass transition point of the resin particles, the salting-out / fusion of the resin particles proceeds rapidly, but the particle size cannot be controlled. There arises a problem that particles having a particle size are generated. The range of the addition temperature may be equal to or lower than the glass transition point of the resin, but is generally preferably 20 to 45 ° C.

  Further, the salting-out agent is added below the glass transition point of the resin particles, and then the temperature is raised as quickly as possible, and the temperature is above the glass transition point of the resin particles and above the melting peak temperature (° C.) of the mixture. Heat to. The time until this temperature rise is preferably less than 1 hour. Further, although it is necessary to quickly raise the temperature, the rate of temperature rise is preferably 0.25 ° C./min or more. The upper limit is not particularly clear, but if the temperature is increased instantaneously, salting out proceeds rapidly, so there is a problem that particle size control is difficult, and 5 ° C./min or less is preferable. By this fusion step, a dispersion of associated particles (core particles) formed by salting out / fusion of resin particles and arbitrary fine particles is obtained.

(4) First aging step And, in the present invention, by controlling the heating temperature of the coagulation / fusion step and particularly the heating temperature and time of the first aging step, the particle size is constant and the distribution is narrow. The core particle surface is controlled so as to have a smooth but uniform shape. Specifically, the heating temperature is lowered in the aggregation / fusion process to suppress the progress of fusion between the resin particles to promote homogenization, the heating temperature is lowered in the first aging process, and the time The surface of the core particles is controlled to have a uniform shape by increasing the length.

(5) Shelling step In the shelling step, the resin particle dispersion for the shell is added to the core particle dispersion to agglomerate and fuse the shell resin particles on the surface of the core particle, and the shell is formed on the core particle surface. The resin particles are coated to form colored particles.

  Specifically, the core particle dispersion is added with a dispersion of resin particles for shells while maintaining the temperature in the above-described aggregation / fusion process and the first aging process, and it takes several hours while continuing heating and stirring. Then, the resin particles for shell are slowly coated on the surface of the core particles to form colored particles. The heating and stirring time is preferably 1 to 7 hours, particularly preferably 3 to 5 hours.

(6) Second ripening step Resin for shell which is added to a core particle after adding a terminator such as sodium chloride at the stage where colored particles have reached a predetermined particle size by shelling to stop particle growth. Heating and stirring are continued for several hours in order to fuse the particles. In the shelling step, a shell having a thickness of 100 to 300 nm is formed on the surface of the core particle. In this way, resin particles are fixed to the surface of the core particles to form a shell, and rounded and colored particles having a uniform shape are formed.

  It is possible to control the shape of the colored particles in the true sphere direction by setting the time of the second aging step longer or by setting the aging temperature higher.

(7) Cooling Step / Solid-Liquid Separation / Washing Step This step is a step of cooling (rapid cooling) the dispersion of the colored particles. As a cooling treatment condition, cooling is performed at a cooling rate of 1 to 20 ° C./min. The cooling treatment method is not particularly limited, and examples thereof include a method of cooling by introducing a refrigerant from the outside of the reaction vessel, and a method of cooling by directly introducing cold water into the reaction system.

  In this solid-liquid separation / washing step, a solid-liquid separation process for solid-liquid separation of the colored particles from the dispersion of colored particles cooled to a predetermined temperature in the above-described step, and a solid-liquid separated toner cake (in a wet state) A cleaning treatment is performed to remove deposits such as a surfactant and a salting-out agent from an aggregate obtained by agglomerating certain colored particles into a cake. Here, the filtration method is not particularly limited, such as a centrifugal separation method, a vacuum filtration method using Nutsche or the like, a filtration method using a filter press or the like.

(8) Drying step This step is a step of drying the washed cake to obtain dried colored particles. Examples of the dryer used in this step include a spray dryer, a vacuum freeze dryer, a vacuum dryer, etc., a stationary shelf dryer, a mobile shelf dryer, a fluidized bed dryer, a rotary dryer. It is preferable to use a stirring dryer or the like. The water content of the dried colored particles is preferably 5% by mass or less, more preferably 2% by mass or less. In addition, when the dried colored particles are aggregated by weak interparticle attractive force, the aggregate may be crushed. Here, as the crushing treatment apparatus, a mechanical crushing apparatus such as a jet mill, a Henschel mixer, a coffee mill, or a food processor can be used.

(9) External Addition Processing Step This step is a step for preparing a toner by mixing an external additive with dried colored particles.

  As an external additive mixing device, a mechanical mixing device such as a Henschel mixer or a coffee mill can be used.

(Resin particle diameter)
The mass average particle diameter (dispersed particle diameter) of the resin particles is preferably in the range of 10 to 1000 nm, more preferably 30 to 300 nm.

  The mass average particle diameter is measured using an electrophoretic light scattering photometer “ELS-800” (manufactured by Otsuka Electronics Co., Ltd.).

(Toner particle diameter)
The toner of the present invention preferably has a volume-based median diameter (D ₅₀ ) of 3 to 8 μm. This is because with this particle size, reproducibility of image quality corresponding to high image quality can be expected.

The median diameter (D ₅₀ ) on the basis of the volume of toner is measured and calculated using a device in which a computer system for data processing (Beckman Coulter) is connected to Coulter Multisizer 3 (Beckman Coulter). Can be obtained.

  As a measurement procedure, 0.02 g of toner is blended with 20 ml of a surfactant solution (for example, a surfactant solution obtained by diluting a neutral detergent containing a surfactant component 10 times with pure water for the purpose of dispersing the toner). After that, ultrasonic dispersion is performed for 1 minute to prepare a toner dispersion. This toner dispersion is poured into a beaker containing ISOTON II (manufactured by Beckman Coulter) in a sample stand with a pipette until the display density of the measuring instrument becomes 5% to 10%. By setting this concentration range, a reproducible measurement value can be obtained. In the measuring machine, the measurement particle count is 25000, the aperture diameter is 50 μm, and the frequency value is calculated by dividing the measurement range of 1 to 30 μm into 256 parts. The particle diameter of 50% from the larger volume integrated fraction is defined as the median diameter on the volume basis.

<Developer>
The toner of the present invention can be used as a one-component developer, a non-magnetic one-component developer, or a two-component developer.

  When used as a one-component developer, examples include a non-magnetic one-component developer or a magnetic one-component developer containing about 0.1 to 0.5 μm magnetic particles in a toner. be able to. Further, it can be mixed with a carrier and used as a two-component developer. In this case, conventionally known materials typified by iron-containing magnetic particles such as iron, ferrite, and magnetite can be used as the magnetic particles of the carrier, but ferrite particles or magnetite particles are particularly preferable. The volume average particle diameter of the carrier is preferably 15 to 100 μm, more preferably 20 to 80 μm.

The measurement of the median diameter (D ₅₀ ) based on the volume of the carrier can be measured using a laser diffraction particle size distribution measuring device “HELOS” (manufactured by Sympathec).

  The carrier is preferably a coating carrier in which magnetic particles are further coated with a resin, or a so-called resin dispersion type carrier in which magnetic particles are dispersed in a resin. The resin composition for coating is not particularly limited, and for example, olefin resin, styrene resin, styrene-acrylic resin, silicone resin, ester resin, fluorine-containing polymer resin, or the like is used. Moreover, it does not specifically limit as resin for comprising a resin dispersion type carrier, A well-known thing can be used, For example, a styrene-acrylic-type resin, a polyester resin, a fluorine resin, a phenol resin etc. are used. be able to.

  Further, the mixing ratio of the carrier and the toner is preferably in the range of carrier: toner = 1: 1 to 50: 1 by mass ratio.

<< Image Forming Method and Image Forming Apparatus >>
Next, an image forming method and an image forming apparatus that can use the toner of the present invention will be described. The toner of the present invention is preferably used in, for example, a high-speed full-color image forming apparatus having a printing speed of 300 mm / sec or higher (65 sheets / min output performance in terms of A4 size paper) or higher. Specifically, a printer or the like that can create a large amount of documents on demand in a short time. Further, the present invention can be applied to an image forming method in which the temperature of the fixing roller is 150 ° C. or lower, preferably 130 ° C. or lower.

  FIG. 1 is a schematic view showing an example of an image forming apparatus that can use the toner of the present invention.

  In FIG. 1, 1Y, 1M, 1C and 1K are photoreceptors, 4Y, 4M, 4C and 4K are developing devices, 5Y, 5M, 5C and 5K are primary transfer rolls as primary transfer means, and 5A is a secondary transfer. Secondary transfer rolls as means, 6Y, 6M, 6C and 6K are cleaning devices, 7 is an intermediate transfer member unit, 24 is a heat roll type fixing device, and 70 is an intermediate transfer member.

  This image forming apparatus is called a tandem color image forming apparatus, and includes a plurality of sets of image forming units 10Y, 10M, 10C, and 10K, an endless belt-shaped intermediate transfer body unit 7 as a transfer unit, and a recording member P. An endless belt-shaped sheet feeding / conveying means 21 and a heat roll type fixing device 24 as a fixing means. A document image reading device SC is disposed on the upper part of the main body A of the image forming apparatus.

  As one of the different color toner images formed on each photoconductor, an image forming unit 10Y that forms a yellow image includes a drum-shaped photoconductor 1Y as a first photoconductor, and a periphery of the photoconductor 1Y. A charging unit 2Y, an exposure unit 3Y, a developing unit 4Y, a primary transfer roll 5Y as a primary transfer unit, and a cleaning unit 6Y. An image forming unit 10M that forms a magenta image as another different color toner image is disposed around a drum-shaped photoconductor 1M as a first photoconductor, and the photoconductor 1M. A charging unit 2M, an exposure unit 3M, a developing unit 4M, a primary transfer roll 5M as a primary transfer unit, and a cleaning unit 6M. In addition, an image forming unit 10C that forms a cyan image as another different color toner image is disposed around the photoconductor 1C as a drum-type photoconductor 1C as a first photoconductor. The charging unit 2C, the exposure unit 3C, the developing unit 4C, the primary transfer roll 5C as the primary transfer unit, and the cleaning unit 6C are provided. Further, an image forming unit 10K that forms a black image as one of other different color toner images is disposed around a drum-shaped photosensitive member 1K as a first photosensitive member, and the photosensitive member 1K. It has a charging means 2K, an exposure means 3K, a developing means 4K, a primary transfer roll 5K as a primary transfer means, and a cleaning means 6K.

  The endless belt-like intermediate transfer body unit 7 has an endless belt-like intermediate transfer body 70 as an intermediate transfer endless belt-like second image carrier that is wound around a plurality of rolls and is rotatably supported.

  Each color image formed by the image forming units 10Y, 10M, 10C, and 10K is sequentially transferred onto the rotating endless belt-shaped intermediate transfer body 70 by the primary transfer rolls 5Y, 5M, 5C, and 5K, and is combined. A colored image is formed. A recording member P such as a sheet as a transfer material accommodated in the sheet feeding cassette 20 is fed by the sheet feeding / conveying means 21, passes through a plurality of intermediate rolls 22 A, 22 B, 22 C, 22 D, and a registration roll 23, and is secondary A color image is transferred onto the recording member P at a time by being conveyed to a secondary transfer roll 5A as a transfer means. The recording member P to which the color image has been transferred is fixed by the heat roll type fixing device 24, is sandwiched by the paper discharge roll 25, and is placed on the paper discharge tray 26 outside the apparatus.

  On the other hand, after the color image is transferred to the recording member P by the secondary transfer roll 5A, the residual toner is removed from the endless belt-shaped intermediate transfer body 70 from which the recording member P is separated by the curvature by the cleaning means 6A.

  During the image forming process, the primary transfer roll 5K is always in pressure contact with the photoreceptor 1K. The other primary transfer rolls 5Y, 5M, and 5C are in pressure contact with the corresponding photoreceptors 1Y, 1M, and 1C, respectively, only during color image formation.

  The secondary transfer roll 5A comes into pressure contact with the endless belt-shaped intermediate transfer body 70 only when the recording member P passes through the secondary transfer roll 5A and secondary transfer is performed.

  Further, the housing 8 can be pulled out from the apparatus main body A through the support rails 82L and 82R.

  The housing 8 includes image forming units 10Y, 10M, 10C, and 10K, and an endless belt-shaped intermediate transfer body unit 7.

  The image forming units 10Y, 10M, 10C, and 10K are arranged in tandem in the vertical direction. An endless belt-shaped intermediate transfer body unit 7 is disposed on the left side of the photoreceptors 1Y, 1M, 1C, and 1K in the figure. The endless belt-shaped intermediate transfer body unit 7 includes an endless belt-shaped intermediate transfer body 70 that can be rotated by winding rolls 71, 72, 73, 74, and 76, primary transfer rolls 5Y, 5M, 5C, and 5K, and a cleaning unit. 6A.

  The image forming units 10Y, 10M, 10C, and 10K and the endless belt-shaped intermediate transfer body unit 7 are integrally pulled out from the main body A by the drawer operation of the housing 8.

  In this way, toner images are formed on the photoreceptors 1Y, 1M, 1C, and 1K by charging, exposure, and development, and the toner images of the respective colors are superimposed on the endless belt-shaped intermediate transfer body 70, and are collectively applied to the recording member P. The image is transferred and fixed by the fixing device 24 by pressing and heating. The photoreceptors 1Y, 1M, 1C, and 1K after transferring the toner image to the recording member P are cleaned with the cleaning device 6A to remove the toner remaining on the photoreceptor, and then the above-described charging, exposure, and development cycle. The next image formation is performed.

  In FIG. 1, 1Y, 1M, 1C and 1K are photosensitive members, 4Y, 4M, 4C and 4K are developing means, 5Y, 5M, 5C and 5K are primary transfer rolls as primary transfer means, and 5A is a secondary transfer. Secondary transfer rolls as means, 6Y, 6M, 6C and 6K are cleaning means, 7 is an intermediate transfer member unit, 24 is a heat roll type fixing device, and 70 is an intermediate transfer member.

  The toner of the present invention employs a so-called low-temperature fixing technology that can fix a toner image at a temperature lower than the current fixing temperature by setting the glass transition temperature to 20 to 45 ° C. That is, even if the transfer material on which the toner image formed with the toner of the present invention is formed is subjected to a fixing treatment under the condition that the surface temperature of the heating roll is 90 to 150 ° C., for example, at the place where the transfer material is bent As a result, a stable crease fixing strength or the like for evaluating the fixing property of the toner can be obtained.

  When the toner of the present invention is used in an image forming apparatus compatible with low-temperature fixing, the surface temperature of the heating member in the fixing device is set in the above range, particularly less than 140 ° C., and the surface temperature of the heating member is set less than 130 ° C. Is possible.

  Specific examples of the fixing device include a fixing device using a heating roll shown in FIG. Further, when the toner of the present invention is used, the fixing device is required to efficiently supply the heat supplied from the heating member to the transfer material, and either the heating member or the pressure member has a heat resistant belt. A fixing device called a belt fixing using a toner is preferable.

  FIG. 2 is a schematic diagram illustrating an example of a heat fixing type fixing device (a type using a pressure roll and a heat roll).

  The fixing device 24 shown in FIG. 2 includes a heating roll 240 and a pressure roll 241 in contact with the heating roll 240. In FIG. 2, 246 is a separation claw, and P is a transfer material (transfer paper) on which the toner image 17 is formed.

  The heating roll 240a has, for example, a coating layer 82 made of a fluororesin or an elastic body formed on the surface of the cored bar 240a, and includes a heating member 244 made of a linear heater.

  The core metal 240 is made of metal and has an inner diameter of 10 to 70 mm. Although the metal which comprises the metal core 240 is not specifically limited, For example, metals, such as iron, aluminum, copper, and these alloys can be mentioned.

  The thickness of the core metal 240a is 0.1 to 15 mm, and is preferably determined in consideration of a balance between a request for energy saving (thinning) and strength (depending on constituent materials). For example, in order to maintain the same strength as that of a cored bar made of iron of 0.57 mm with a cored bar made of aluminum, the wall thickness needs to be 0.8 mm.

  Examples of the fluororesin constituting the surface of the coating layer 240c include polytetrafluoroethylene (PTFE) and tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA).

  The thickness of the coating layer 240c made of a fluororesin is 10 to 500 μm, preferably 20 to 400 μm.

  In addition, as the elastic body constituting the coating layer 240c, it is preferable to use silicon rubber, silicon sponge rubber, or the like having good heat resistance such as LTV, RTV, and HTV.

  The Asker C hardness of the elastic body constituting the coating layer 240c is less than 80 °, preferably less than 60 °.

  Moreover, 0.1-30 mm is preferable and, as for the thickness of the coating layer 240c, 0.1-20 mm is more preferable.

  As the heating member 244, a halogen heater can be preferably used.

  The pressure roll 250 is formed by forming a coating layer 250b made of an elastic body on the surface of the cored bar 250a. The elastic body constituting the covering layer 250b is not particularly limited, and examples thereof include various soft rubbers such as urethane rubber and silicon rubber, and sponge rubber. Among these, silicon rubber and silicon sponge rubber are preferable.

  The thickness of the coating layer 250b is preferably 0.1 to 30 mm, and more preferably 0.1 to 20 mm.

  The fixing temperature (surface temperature of the heating roll 240) is a temperature at which the temperature of the transfer material can be set to around 100 ° C. during fixing, and is 70 to 180 ° C., although it depends on the fixing linear speed described later. The fixing linear velocity is preferably 80 to 640 mm / sec, and the nip width between the heating roll 240 and the pressure roll 250 is set to 8 to 40 mm, preferably 11 to 30 mm.

  The separation claw 246 is provided to prevent the transfer material heat-fixed on the heating roll 240 from being wound around the heating roll.

  FIG. 3 is a schematic view showing an example of a heat fixing type fixing device (a type using a seamless belt and a heating roll).

  The fixing device 24 shown in FIG. 3 is a type using a belt and a heating roll to ensure a nip width, and is pressed against the heating roll 240 via the heating roll 240, the seamless belt 241, and the seamless belt 241. The pressure pad (pressure member) 242a, the pressure pad (pressure member) 242b, and the lubricant supply member 243 constitute main parts.

  The heating roll 240 is formed of a heat-resistant elastic layer 240b and a release layer (heat-resistant resin layer) 240c around a metal core (cylindrical core) 240a, and a heat source is provided inside the core 240a. A halogen lamp 244 is arranged. The surface temperature of the heating roll 240 is measured by the temperature sensor 245, and the halogen lamp 244 is feedback-controlled by a temperature control (not shown) based on the measurement signal, so that the surface of the heating roll 240 is adjusted to a constant temperature. The seamless belt 241 is in contact with the heating roll 240 so as to be wound at a predetermined angle, thereby forming a nip portion.

  Inside the seamless belt 241, a pressure pad 242 having a low friction layer on its surface is disposed in a state of being pressed against the heating roll 240 via the seamless belt 241. The pressure pad 242 is provided with a pressure pad 242a to which a strong nip pressure is applied and a pressure pad 242b to which a weak nip pressure is applied, and is held by a holder 242c made of metal or the like.

  A belt traveling guide is attached to the holder 242c so that the seamless belt 241 slides and rotates smoothly. The belt running guide is preferably a member having a low coefficient of friction because it rubs against the inner surface of the seamless belt 241, and a member having low thermal conductivity is preferred so that heat is not easily taken from the seamless belt 241. A specific example of the material of the seamless belt 241 is, for example, polyimide.

  The toner image 17 formed with the toner of the present invention is finally transferred onto the transfer material P, and fixed on the transfer material by a fixing process to form an image. The transfer material P used for the image formation is a support for holding a toner image, and is usually called an image support, a recording material, or transfer paper. Specifically, various transfer materials such as plain paper and fine paper from thin paper to thick paper, coated printing paper such as art paper and coated paper, commercially available Japanese paper and postcard paper, plastic film for OHP, cloth, etc. However, it is not limited to these.

  EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited to these embodiments.

<Production of toner>
Hereinafter, preparation of toner will be described.

<Preparation of resin particles>
[Preparation of Resin Particle 1]
(First polymerization)
Styrene 209 parts by weight n-butyl acrylate 141 parts by weight Methacrylic acid 25 parts by weight n-Octyl mercaptan 5 parts by weight of monomer mixture is placed in a stainless steel kettle equipped with a stirrer, and pentaerythritol tetrabehenate ester 100 A part by mass was added, heated to 70 ° C. and dissolved to prepare a monomer solution.

  Meanwhile, a surfactant solution prepared by dissolving 2 parts by mass of sodium polyoxyethylene (2) dodecyl ether sulfate in 1350 parts by mass of ion-exchanged water is heated to 70 ° C., added to the monomer solution, mixed, Dispersion was performed at 70 ° C. for 30 minutes using a mechanical disperser CLEARMIX (manufactured by M Technique Co., Ltd.) to prepare an emulsified dispersion.

  Next, a polymerization initiator solution in which 11.3 parts by mass of potassium persulfate (water-soluble polymerization initiator) was dissolved in 225 parts by mass of ion-exchanged water was added to this emulsified dispersion. Polymerization was performed by heating and stirring for 5 hours to obtain latex (resin fine particles). This is designated as “Latex 1”.

(Second polymerization (formation of outer layer))
To the latex 1 obtained as described above, an initiator solution in which 10 parts by mass of potassium persulfate is dissolved in 190 parts by mass of ion-exchanged water is added, and under a temperature condition of 80 ° C.,
Styrene 286.5 parts by mass n-butyl acrylate (n-BA) 192.7 parts by mass Methacrylic acid 34.9 parts by mass n-octyl mercaptan 7.0 parts by mass was added dropwise over 1 hour. After completion of the dropwise addition, the polymerization was advanced while measuring the polymerization rate with GPC. When the polymerization rate reached 90%, 4.5 parts by mass of benzoyl peroxide (oil-soluble polymerization initiator) was added. The system was heated and stirred at 90 ° C. for 1 hour to complete the polymerization reaction, and then cooled to 28 ° C. to obtain a latex. This latex is referred to as “resin particle 1 (core latex)”.

[Preparation of Resin Particle 2]
(First polymerization)
Styrene 199 parts by weight n-butyl acrylate 151 parts by weight Methacrylic acid 25 parts by weight n-octyl mercaptan 5 parts by weight (second polymerization (formation of outer layer))
Styrene 272.3 parts by mass n-butyl acrylate 206.9 parts by mass Methacrylic acid 34.9 parts by mass n-octyl mercaptan 7.0 parts by mass Except for changing the composition ratio of the first polymerization and the second polymerization as described above. “Resin particles 2” were produced in the same manner as in the production of resin particles 1.

[Preparation of Resin Particle 3]
(First polymerization)
Styrene 231 parts by weight 2-ethylhexyl acrylate (n-EHA) 118 parts by weight Methacrylic acid 25 parts by weight n-octyl mercaptan 5 parts by weight (second polymerization (formation of outer layer))
Styrene 316.9 parts by mass 2-ethylhexyl acrylate 162.3 parts by mass Methacrylic acid 34.9 parts by mass n-octyl mercaptan 7.0 parts by mass Except for changing the composition ratio of the first polymerization and the second polymerization as described above. “Resin particles 3” were produced in the same manner as in the production of the resin particles 1.

[Preparation of Resin Particle 4]
(First polymerization)
Styrene 220 parts by mass n-butyl acrylate 130 parts by mass Methacrylic acid 25 parts by mass n-octyl mercaptan 5 parts by mass (second polymerization (formation of outer layer))
Styrene 301.7 parts by weight n-butyl acrylate 177.5 parts by weight Methacrylic acid 34.9 parts by weight n-octyl mercaptan 7.0 parts by weight Except for changing the composition ratio of the first polymerization and the second polymerization as described above. “Resin particles 4” were produced in the same manner as in the production of the resin particles 1.

[Preparation of resin particles 5]
(First polymerization)
Styrene 220 parts by mass n-butyl acrylate 130 parts by mass Methacrylic acid 25 parts by mass n-octyl mercaptan 5 parts by mass (second polymerization (formation of outer layer))
Styrene 301.7 parts by weight n-butyl acrylate 177.5 parts by weight Methacrylic acid 34.9 parts by weight n-octyl mercaptan 7.0 parts by weight The composition ratio of the first polymerization and the second polymerization was changed as described above, and benzoyl “Resin particles 5” were produced in the same manner as in the production of the resin particles 1 by adding 0.04 parts by mass of peroxide.

[Preparation of Resin Particle 6]
(First polymerization)
Styrene 276 parts by weight Lauryl acrylate 74 parts by weight Methacrylic acid 25 parts by weight n-octyl mercaptan 5 parts by weight (second polymerization (formation of outer layer))
Styrene 377.8 parts by weight Lauryl acrylate 101.4 parts by weight Methacrylic acid 34.9 parts by weight n-Octyl mercaptan 7.0 parts by weight Resin particles except that the composition ratio of the first polymerization and the second polymerization was changed as described above “Resin particles 6” were produced in the same manner as in 1.

[Preparation of Resin Particle 7]
(First polymerization)
Styrene 183 parts by mass n-butyl acrylate 167 parts by mass Methacrylic acid 25 parts by mass n-octyl mercaptan 5 parts by mass (second polymerization (formation of outer layer))
Styrene 251.0 parts by weight n-butyl acrylate 228.2 parts by weight Methacrylic acid 34.9 parts by weight n-octyl mercaptan 7.0 parts by weight Except for changing the composition ratio of the first polymerization and the second polymerization as described above. “Resin particles 7” were produced in the same manner as in the production of the resin particles 1.

[Preparation of resin particles 8]
“Resin particles 8” were produced in the same manner as in the production of the resin particles 1 except that the polymerization initiator to be added was not added at the latter stage of the second polymerization.

[Preparation of resin particles 9]
“Resin particles 9” were prepared in the same manner as the resin particles 1 except that the polymerization initiator to be added was changed to 3.0 parts by mass of potassium persulfate at the latter stage of the second polymerization.

[Preparation of Resin Particle 10]
(First polymerization)
Styrene 294 parts by weight Lauryl acrylate 55 parts by weight Methacrylic acid 25 parts by weight n-octyl mercaptan 5 parts by weight (second polymerization (formation of outer layer))
Styrene 403.1 parts by weight Lauryl acrylate 76.1 parts by weight Methacrylic acid 34.9 parts by weight n-Octyl mercaptan 7.0 parts by weight Resin particles except that the composition ratio of the first polymerization and the second polymerization was changed as described above “Resin particles 10” were produced in the same manner as in 1.

[Production of Resin Particles 11]
(First polymerization)
Styrene 294 parts by mass n-butyl acrylate 56 parts by mass Methacrylic acid 25 parts by mass n-octyl mercaptan 5 parts by mass (second polymerization (formation of outer layer))
Styrene 403.1 parts by mass n-butyl acrylate 76.1 parts by mass Methacrylic acid 34.9 parts by mass n-octyl mercaptan 7.0 parts by mass Except for changing the composition ratio of the first polymerization and the second polymerization as described above. “Resin particles 11” were produced in the same manner as in the production of the resin particles 1.

[Production of Resin Particles 12]
(First polymerization)
Styrene 165 parts by weight n-butyl acrylate 185 parts by weight Methacrylic acid 25 parts by weight n-octyl mercaptan 5 parts by weight (second polymerization (formation of outer layer))
Styrene 225.7 parts by mass n-butyl acrylate 253.6 parts by mass Methacrylic acid 34.9 parts by mass n-octyl mercaptan 7.0 parts by mass Except for changing the composition ratio of the first polymerization and the second polymerization as described above. “Resin particles 12” were produced in the same manner as in the production of the resin particles 1.

[Preparation of Resin Particle 13]
(First polymerization)
Styrene 255 parts by mass n-butyl acrylate 94 parts by mass Methacrylic acid 25 parts by mass n-octyl mercaptan 5 parts by mass (second polymerization (formation of outer layer))
Styrene 349.9 parts by weight n-butyl acrylate 129.3 parts by weight Methacrylic acid 34.9 parts by weight n-octyl mercaptan 7.0 parts by weight The composition ratio of the first polymerization and the second polymerization was changed as described above, and benzoyl “Resin particles 13” were produced in the same manner as in the production of the resin particles 1 except that 10 parts by mass of peroxide was added.

[Production of Resin Particles 14]
(First polymerization)
Styrene 242 parts by mass n-butyl acrylate 107 parts by mass Methacrylic acid 25 parts by mass n-octyl mercaptan 5 parts by mass (second polymerization (formation of outer layer))
Styrene 332.2 parts by mass n-butyl acrylate 147.1 parts by mass Methacrylic acid 34.9 parts by mass n-octyl mercaptan 7.0 parts by mass The composition ratio of the first polymerization and the second polymerization was changed as described above, and benzoyl “Resin particles 14” were produced in the same manner as in the production of the resin particles 1 by adding 10 parts by mass of peroxide.

<Preparation of resin particles for shell>
In a stainless steel kettle (SUS kettle) equipped with a stirrer, temperature sensor, cooling pipe, and nitrogen introducing device, a surfactant solution in which 8 parts by mass of sodium dodecyl sulfate was dissolved in 3000 parts by mass of ion-exchanged water was charged under a nitrogen stream. While stirring at a stirring speed of 230 rpm, the liquid temperature was raised to 80 ° C.

  To this surfactant solution, a polymerization initiator solution in which 10 parts by mass of potassium persulfate was dissolved in 200 parts by mass of ion-exchanged water was added and the temperature was adjusted to 80 ° C. Then, the following monomer mixture was added dropwise over 100 minutes. The system was polymerized by heating and stirring at 80 ° C. for 2 hours to produce “shell resin particles”.

Styrene 570 parts by mass n-butyl acrylate 165 parts by mass Methacrylic acid 70 parts by mass n-octyl mercaptan 5.5 parts by mass <Preparation of Toner 1>
(Preparation of Colorant Particle Dispersion 1)
90 parts by mass of sodium polyoxyethylene (2) dodecyl ether sulfate was dissolved in 1600 parts by mass of ion-exchanged water with stirring. While stirring this solution, 400 parts by mass of carbon black “Regal 330” (manufactured by Cabot) was gradually added, and then dispersed using a stirrer “Claremix” (manufactured by M Technique). Colorant particle dispersion 1 was prepared.

(Aggregation / fusion process) (Preparation of core particle 1)
420.7 parts by mass (solid content conversion) of “resin particles 1”, 900 parts by mass of ion-exchanged water, and 200 parts by mass of “colorant particle dispersion 1”, a temperature sensor, a cooling pipe, a nitrogen introducing device, The mixture was stirred in a reaction vessel equipped with a stirrer. After adjusting the temperature in a container to 30 degreeC, 5 mol / liter sodium hydroxide aqueous solution was added to this solution, and pH was adjusted to 8-11.

Next, an aqueous solution obtained by dissolving 2 parts by mass of magnesium chloride hexahydrate in 1000 parts by mass of ion-exchanged water was added over 10 minutes at 30 ° C. with stirring. After standing for 3 minutes, the temperature was raised and the system was heated to 65 ° C. over 60 minutes. While confirming the particle diameter with the Coulter Multisizer 3, when aggregation was advanced until the median diameter (D ₅₀ ) on the volume basis reached 6.5 μm, 40.2 parts by mass of sodium chloride was added to 1000 parts by mass of ion-exchanged water. The aqueous solution dissolved in the part was added to stop the growth of the particle size, and further, the fusion was continued by heating and stirring at a liquid temperature of 70 ° C. for 1 hour as a ripening treatment to produce “core particle 1”.

(Formation of shell layer (shelling operation))
Next, 96 parts by mass (solid content conversion) of resin particles for shells are added at 65 ° C., and an aqueous solution in which 2 parts by mass of magnesium chloride hexahydrate is dissolved in 1000 parts by mass of ion-exchanged water is added over 10 minutes. Then, the temperature was raised to 70 ° C. (shelling temperature), and stirring was continued for 1 hour to fuse “resin particle 1 for shell layer” onto the surface of the core particle 1, and then 20 minutes at 75 ° C. An aging treatment was performed to form a shell layer.

Here, 40.2 parts by mass of sodium chloride was added, the mixture was cooled to 30 ° C. at 8 ° C./min, and the produced fused particles were filtered and repeatedly washed with ion-exchanged water at 45 ° C. By drying with warm air, “colored particles 1” having a volume-based median diameter (D ₅₀ ) of 6.6 μm and having a shell layer on the surface of the core particles were produced.

(External additive treatment)
1% by mass of hydrophobic silica (number average primary particle size = 12 nm, degree of hydrophobicity = 68) and 1.2% of hydrophobic titanium oxide (number average primary particle size = 20 nm, degree of hydrophobicity = 63) are added to the colored particles 1. “Toner 1” was prepared by adding a mass% and mixing with a Henschel mixer.

<Preparation of Toner 2-15>
“Toners 2-15” were prepared in the same manner except that the resin particles 1 used in the preparation of the toner 1 were changed to “resin particles 2-15”.

  Table 1 shows the compound represented by the general formula (1) used for the preparation of the toner, the polymerization initiator added in the latter stage, the volatilization amount of the compound represented by the general formula (1), aromatic carboxylic acid, aliphatic The content of a compound selected from carboxylic acid and aliphatic alcohol, Tg, Mw, and Mw / Mn are shown.

  The volatilization amount of the compound represented by the general formula (1), the content of the compound selected from aromatic carboxylic acid, aliphatic carboxylic acid, and aliphatic alcohol, Tg, Mw, and Mw / Mn are described above. It is the value obtained by measuring by the method.

<Production of developer>
Next, a ferrite carrier coated with a silicone resin and having a volume average particle diameter of 50 μm was mixed with each of the toners prepared above, and “Developers 1 to 15” having a toner concentration of 6% by mass were prepared.

<Evaluation>
For the evaluation, a digital color multi-function peripheral “bizhub PRO C500” (manufactured by Konica Minolta Business Technologies) was used, the toner and the developer prepared above were loaded in order, printed, and the following items were evaluated.

  The printing was performed using an image with an image portion of 10% (an original image in which a character image is 7%, a human face photo, a solid white image, and a solid black image are each divided into quarters). In the evaluation, ◎ and ○ were acceptable.

<Low temperature fixability>
Evaluation of low-temperature fixability is performed in an environment of 20 ° C. and 55% RH, and the surface temperature of the heating roller of the fixing device of the evaluation machine is changed in increments of 10 ° C. within the range of the print paper surface temperature of 80 to 150 ° C. The toner image was fixed at each temperature to produce a print image. In creating the print image, A4 size high quality paper (80 g / m ² ) was used as the print paper.

  The fixing strength of the printed image obtained by fixing is fixed using a method in accordance with the mending tape peeling method described in Chapter 9 Section 1.4 of “Basics and Applications of Electrophotographic Technology: Electrophotographic Society”. The rate was evaluated.

Specifically, after creating a 2.54 cm square solid black print image with a toner adhesion amount of 0.6 mg / cm ² , the image density before and after peeling with a scotch mending tape (manufactured by Sumitomo 3M) was measured. The residual ratio of image density was determined as a fixing ratio.

  The printing paper surface temperature at which the fixing rate is 95% or more is defined as the minimum fixing temperature. The print paper surface temperature was measured with a non-contact thermometer. The image density was measured with a reflection densitometer “RD-918” (manufactured by Macbeth).

Evaluation criteria A: Fixing is possible at a minimum fixing temperature of less than 100 ° C. ○: Fixing is possible at a minimum fixing temperature of 100 ° C. or more and less than 130 ° C. ×: Fixing is possible at a minimum fixing temperature of 130 ° C. or more.

<Transfer missing>
For missing images, 100 half-tone images with an image density of 0.4 were printed on both sides of A4 size fine paper (64 g / m ² ), and the occurrence of white spots due to missing images was visually evaluated.

Evaluation criteria ◎: No transfer omission ○: 1 to 5 transfer omissions exist only on the back surface per 100 prints, but there is no practical problem because it cannot be done without staring. There are 5 or more clear transfer omissions, which is a practical problem.

<Uneven density of halftone part>
The density unevenness of the halftone portion was evaluated by visual observation of the 100th image printed by the evaluation of transfer omission.

Evaluation Criteria ◎: No density unevenness is recognized ○: Slight density unevenness is confirmed, but there is no problem in practical use ×: The density unevenness is recognized, and there is practical problem <Odor during image formation>
Ten people engaged in the light printing industry were asked to become monitors, and the evaluation was based on “the number of people who are bothered by odors and the number of people who are not concerned” at the fixing section after 10,000 sheets were printed.

Evaluation Criteria ◎: Eight or more of 10 people do not care about odor ○: Six or more of 10 people are worried about odor, but are not uncomfortable ×: More than 5 out of 10 people are odorous Complained of discomfort.

<Heat resistant storage>
100 g of each toner was allowed to stand for 24 hours under conditions of 55 ° C. and 90% RH, and then sieved with a sieve having an opening of 45 μm. The amount (ratio) of the aggregate remaining on the sieve was used for heat-resistant storage stability (toner storage stability). ) Was evaluated.

Evaluation Criteria A: Less than 5% by mass remaining on the sieve, very little agglomeration, excellent (no agglomeration even if transported in summer without any heat insulation packaging)
○: The amount remaining on the sieve is 5-30% by mass and the amount of agglomeration is small and good (no agglomeration even if transported in the summer with cardboard packaging only)
X: The amount remaining on the sieve is more than 30% by mass, the amount of aggregation is large, and there is a practical problem (needs cold transport).

  Table 2 shows the evaluation results.

  From Table 2, “Toners 1 to 7” used in Examples 1 to 7 have no image defects such as low-temperature fixability and heat-resistant storage, transfer omission, and density unevenness in the halftone portion, and odors are noticed during heat fixing. It can be seen that there is no problem with heat-resistant storage. On the other hand, it can be seen that “Toners 8 to 15” used in Comparative Examples 1 to 8 have a problem in any of the above evaluation items.

FIG. 2 is a schematic diagram illustrating an example of an image forming apparatus that can use the toner of the present invention. It is the schematic which shows an example of the fixing apparatus (a type using a pressure roll and a heating roll) of a heat fixing system. It is the schematic which shows an example of the fixing apparatus (type using a seam level and a heating roll) of a heat fixing system.

Explanation of symbols

1 Photoconductor (Photoconductor drum)
4 Development device (toner cartridge)
6 Cleaning Device 7 Intermediate Transfer Belt 10 Image Forming Unit 24 Fixing Device 240 Heating Roll 241 Seamless Belt P Transfer Material (Recording Material)

Claims (3)

In the electrostatic image developing toner having a resin obtained by copolymerizing a polymerizable monomer containing a compound represented by the following general formula (1):
The compound represented by the general formula (1) is 20 to 45% by mass with respect to the resin in a composition ratio,
The amount of volatilization of the compound represented by the general formula (1) is 1 to 500 ppm with respect to the electrostatic image developing toner,
Containing 1-1000 ppm of a compound selected from aromatic carboxylic acid, aliphatic carboxylic acid, aliphatic alcohol,
A toner for developing an electrostatic charge image, having a glass transition point of 20 to 45 ° C.
Formula _{(1) H 3 C = CR} 1 -COOR 2
(In the formula, R ₁ represents H or CH ₃ , and R ₂ represents a long-chain alkyl group having 3 to 22 carbon atoms or a cyclic alkyl group.) 2. The electrostatic charge image developing toner according to claim 1, wherein the resin has a weight average molecular weight (Mw) of 10,000 to 50,000 and Mw / Mn of 1.5 to 4. 3. Electrostatic charge image development comprising a step of copolymerizing a polymerizable monomer containing a compound represented by the following general formula (1) to polymerize resin particles, and a step of aggregating and fusing the resin particles and colorant particles In the manufacturing method of the toner,
In the polymerization step, n polymerization reactions are performed (where n is an integer of 2 or more)
The polymerization initiator is added in two or more portions,
A method for producing an electrostatic charge image developing toner, comprising adding an oil-soluble polymerization initiator at a later stage of the n-th polymerization reaction.
Formula _{(1) H 3 C = CR} 1 -COOR 2
(In the formula, R ₁ represents H or CH ₃ , and R ₂ represents a long-chain alkyl group having 3 to 22 carbon atoms or a cyclic alkyl group.)

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