JP2008015230A - Toner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a toner excellent in low temperature fixing property, causing no contamination on a pressure roller, and capable of forming an image of high density without causing fog or melt-sticking of the toner even in long-term use in a high temperature and high humidity environment. <P>SOLUTION: The toner contains at least a binder resin, crystalline polyester and a release agent, wherein the acid value and the hydroxyl value of the crystalline polyester are controlled to the respective specified ranges and the flow start temperature (Tfb) of the toner measured by a flow tester and the melting point (Tm1) of the crystalline polyester satisfy a specified relation. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a toner used in a recording method using an electrophotographic method, an electrostatic recording method, a magnetic recording method, a toner jet method, or the like.

  Many methods are known as electrophotographic methods. Generally, an electrostatic latent image is formed on an electrostatic charge image carrier (hereinafter also referred to as a “photosensitive member”) by using a photoconductive substance by various means. The latent image is then developed with toner to form a visible image, and the toner image is transferred onto a recording medium such as paper as necessary, and then the toner image is fixed on the recording medium with heat or pressure. To obtain a copy. Such image forming apparatuses include copying machines and printers.

  In these printers and copiers, the transition from analog to digital has progressed in recent years, and there is a strong demand for high speed and low power consumption while at the same time being excellent in reproducibility of latent images and high resolution. Here, for example, when focusing on the printer, the ratio of the power consumption in the fixing process to the total power consumption is considerably large, and the power consumption increases as the fixing temperature increases. Further, when the fixing temperature becomes high, problems such as curling of the printout paper after fixing also occur, and there is a great demand for lowering the fixing temperature.

  In addition, there is a strong demand for on-demand in printers and copiers, and so-called surf fixing devices and electromagnetic induction fixing devices have been developed in recent years. However, although these fixing devices are extremely excellent in on-demand characteristics, it is also difficult to apply pressure and more difficult to fix than conventional heat roller type fixing devices.

  Furthermore, since printers are also required to support various materials, there is a great demand for toners having good fixability in a wide temperature range. In addition to demands for reducing power consumption, as the speed of printers and copiers increases, there is also a need to improve the durability and stability of toner in various environments.

  Many studies have been made on low-temperature fixing. For example, a small particle size toner containing a crystalline polyester has been proposed as a toner that has excellent fixability and can form an image with high resolution ( Patent Document 1). Further, in a toner having a crystalline polyester and an amorphous resin, by adjusting the dispersed domain diameter of the crystalline polyester, it has excellent low-temperature fixability and good storage stability, and a high-quality image can be obtained. A toner has been proposed (see Patent Document 2).

  Furthermore, a toner having a resin with a controlled softening point and glass transition temperature, a crystalline polyester, and a high-melting polyolefin has been proposed, and exhibits good fixability in heat roller fixing (see Patent Document 3).

  Thus, although the fixing property is improved to some extent by using crystalline polyester, there is still room for improvement. Furthermore, since crystalline polyester is easy to adsorb | suck a water | moisture content, there also exists a problem that the developability in a high-temperature, high-humidity environment will fall large.

  On the other hand, a toner is disclosed in which the environmental difference in charge amount is improved by making the hydroxyl value and acid value of the crystalline polyester not more than a specific value (see Patent Reference 4). However, since this toner has a low acid value and hydroxyl value of the crystalline polyester, its affinity with paper is insufficient and the fixing property is poor. For this reason, there has been proposed a toner having a crystalline polyester having a unique X-ray diffraction pattern and another polyester and defining the relationship between the softening temperatures of the polyesters (see Patent Reference 5). In addition, a toner using a plurality of binder resins and a crystalline polyester having a low hydroxyl value and low acid value has been proposed (see Patent Reference 6). However, even if such a toner is used, the compatibility between durability stability and low-temperature fixability in a high-temperature and high-humidity environment has not been sufficiently achieved, and there is room for further improvement.

  Further, the printers, copiers, faxes, and the like as described above are increasingly demanded for miniaturization, high speed, and high durability. However, there are problems that must be solved in order to meet this demand. In other words, once offset toner adheres and accumulates on the pressure roller facing the heat roll in the heat roll fixing method and the pressure roller facing the heat resistant film in the pressure heating method, “pressure roller dirt” There is a phenomenon. When this phenomenon progresses and the accumulation amount increases, the paper is wound around the pressure roller, causing paper jam. Therefore, in order to reduce the size, it is necessary to solve this pressure roller contamination in order to simplify the fixing device such as removing a cleaning member that removes the offset toner and to realize the requirement of high durability. .

JP-A-4-184358 JP 2002-287426 A JP-A-62-276666 Japanese Patent No. 2931899 JP 2003-167384 A JP 2003-262978 A

  The present invention has been made in view of the above-described problems of the prior art, has excellent low-temperature fixability, does not cause a decrease in density even when used in a high-temperature and high-humidity environment, and forms a clear image free from fogging and streaks. It is an object to provide a toner that can be used.

  As a result of diligent studies to solve the above problems, a crystalline polyester having a specific acid value and hydroxyl value is used, and the melting point of the crystalline polyester and the starting temperature of the toner measured by a flow tester satisfy a specific relationship. The present inventors have found that a toner having excellent low-temperature fixability and good developability even in a high-temperature and high-humidity environment can be obtained.

That is, according to the present invention, in a toner containing at least a binder resin, a crystalline polyester, and a release agent, the crystalline polyester has an acid value of 4.0 mgKOH / g or less and a hydroxyl value of 5.0 mgKOH / g or less. ,
The toner outflow start temperature (Tfb) and the crystalline polyester melting point (Tm1) measured by a flow tester are expressed by the following formula (1).
Tm1 ≦ Tfb ≦ Tm1 + 12 ° C. (1)
The toner satisfies the above relationship.

According to the present invention, it is possible to provide a toner that is excellent in low-temperature fixability, does not cause a decrease in density even when used in a high-temperature and high-humidity environment, and can form a clear image free from fogging and streaks.

In the toner of the present invention, in a toner containing at least a binder resin, a crystalline polyester, and a release agent, the crystalline polyester has an acid value of 4.0 mgKOH / g or less and a hydroxyl value of 5.0 mgKOH / g or less. ,
The toner outflow start temperature (Tfb) and the crystalline polyester melting point (Tm1) measured by a flow tester are expressed by the following formula (1).
Tm1 ≦ Tfb ≦ Tm1 + 12 ° C. The toner satisfies the relationship (1).

  As a result of intensive studies by the present inventors, a crystalline polyester having specific values of acid value and hydroxyl value was used, and the melting point of the crystalline polyester and the outflow start temperature of the toner satisfy a specific relationship, whereby low temperature fixing and high temperature It has become possible to achieve both developability in a high humidity environment.

  First, it has been found that good low-temperature fixability can be obtained when the melting point of the crystalline polyester and the start-of-flow temperature of the toner satisfy the relationship of Tm1 ≦ Tfb ≦ Tm1 + 12 ° C., preferably Tm1 ≦ Tfb ≦ Tm1 + 6 ° C.

  As will be understood from Examples and Comparative Examples described later, the outflow start temperature of the toner is lowered by adding crystalline polyester and controlling the presence state of the crystalline polyester.

This is because crystalline polyester is not compatible with the binder resin in the temperature range near the melting point, so the crystalline polyester is melted by the heat received from the fixing device, and the toner has a “liquid core structure”. it is conceivable that. In this state, the toner subjected to the pressure from the fixing device is quickly deformed, and accordingly, the release agent oozes out and anchoring to the transfer medium occurs, so that favorable low-temperature fixing is possible.
Therefore, in the present invention, it is necessary that the toner satisfies the relationship of Tm1 ≦ Tfb ≦ Tm1 + 12 ° C.

  Reference documents 2, 5 and the like specify the softening temperature of the binder resin or toner, but the “softening temperature” depends greatly on the molecular weight of the resin or toner, the insoluble matter, etc. There was no correlation.

  When Tfb is higher than Tm1 + 12 ° C., the presence state of the crystalline polyester is not suitable for promoting the deformation of the toner, and the outflow start temperature of the toner does not decrease. Therefore, since the effect of adding crystalline polyester does not appear, it is difficult to obtain good low-temperature fixability. In addition, when Tfb is lower than Tm1, the binder resin is too soft, which may cause toner fusion to the toner carrier and the like during long-term use. Further, in such a case, the crystalline polyester is often compatible with the binder resin at the time of toner production, and the durability tends to be inferior. Or, since the melting point of the crystalline polyester is too high, the effect of addition does not appear, and the fixing temperature does not decrease.

  In addition, by setting the acid value of the crystalline polyester to 4.0 mgKOH / g or less and the hydroxyl value to 5.0 mgKOH / g or less, phase separation between the crystalline polyester and the binder resin is promoted, and a liquid core structure is likely to be obtained. Therefore, the deformation of the toner is further promoted, and the low-temperature fixability is further improved.

  On the other hand, taking a “liquid core structure” when receiving heat from the fixing device also suggests that the crystalline polyester is less exposed to the toner surface.

  Furthermore, even if there is a partially exposed crystalline polyester, the acid value and the hydroxyl value are low (= there is no hydroxyl group or carboxyl group that easily adsorbs moisture), so the chargeability may be impaired even in a high temperature and high humidity environment. And good developability can be maintained.

  When a toner is produced by a production method in an aqueous medium, which is a preferred production method in the present invention, a crystalline polyester having a low acid value and a hydroxyl value is less hydrophilic and therefore hardly exists in the vicinity of the toner surface layer. The developability is improved, which is preferable.

  Therefore, in the present invention, it is important that the hydroxyl value of the crystalline polyester is 5.0 mgKOH / g or less, and the acid value is 4.0 mgKOH / g or less, more preferably 2.5 mgKOH / g or less.

Further, the toner is easily deformed, and when the acid value and hydroxyl value of the crystalline polyester are low, the stain on the pressure roller can be improved.
This is because the releasability to the pressure roller is improved due to the low acid value and hydroxyl value of the crystalline polyester, and the toner is easily deformed. This is due to the synergistic effect that the exudation of the conductive polyester becomes very good.

  As described above, a synergistic effect is obtained by using a crystalline polyester having a low acid value and a hydroxyl value, and setting the relationship between the melting point (Tm1) of the crystalline polyester and the outflow start temperature (Tfb) of the toner to Tm1 ≦ Tfb ≦ Tm1 + 12 ° C. Makes it possible to obtain extremely good low-temperature fixability without pressure roller stains, and to obtain high-density, high-definition images that are free from deterioration in development, fogging, and streaking even in high-temperature and high-humidity environments. Can do.

  Tm1 can be adjusted by selecting an arbitrary crystalline polyester, but Tfb largely depends on the melting point of the crystalline polyester and the toner production method (this will be described later). Tm1 is defined as the peak top temperature of the endothermic peak of the crystalline polyester in DSC (Differential Scanning Calorimetry) measurement. The measurement of the peak top temperature of the endothermic peak by DSC is performed according to “ASTM D 3417-99”.

  In the present invention, in the endothermic curve obtained by differential scanning calorimetry (DSC) measurement, the crystalline polyester preferably has a peak top (Tm2) of an endothermic peak in the range of 60 to 95 ° C. When the melting point of the crystalline polyester is less than 60 ° C., the storage stability of the toner tends to be inferior. On the other hand, if the melting point of the crystalline polyester is higher than 95 ° C., good low-temperature fixability cannot be obtained. Further, in the case where the toner is obtained by the suspension polymerization method, which is a more preferable toner production method in the present invention, the solubility of the crystalline polyester in the polymerizable monomer is likely to deteriorate, and the magnetic powder or crystalline Since the dispersibility of the toner constituting material such as polyester is deteriorated, the fog is increased.

  The number average molecular weight of the crystalline polyester used in the toner of the present invention is preferably 2,000 to 10,000, and more preferably 2,000 to 6,000. When the number average molecular weight of the crystalline polyester is less than 2,000, the compatibility with the binder resin is increased at the time of producing the toner, and the toner is likely to be deteriorated or fused. On the other hand, if the number average molecular weight of the crystalline polyester is larger than 10,000, it is difficult to obtain good dispersibility, and further, the response to heat is lowered (it takes time to melt, etc.). Sex worsens.

  The toner of the present invention preferably contains 3 to 30% by mass of crystalline polyester with respect to the binder resin. When the content of the crystalline polyester is less than 3% by mass, the above-described effects of the present invention are not sufficiently obtained. Further, if the content of the crystalline polyester is more than 30% by mass, it is not preferable because it tends to cause poor dispersion and deteriorates durability.

  The crystalline polyester can be obtained by reacting a divalent or higher polyvalent carboxylic acid with a diol. Among these, a polyester mainly composed of an aliphatic diol and an aliphatic dicarboxylic acid is preferable because of high crystallinity.

  Examples of alcohol monomers for obtaining such a crystalline polyester include ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, dipropylene glycol, trimethylene glycol, and tetramethylene. Examples include glycol, pentamethylene glycol, hexamethylene glycol, octamethylene glycol, nonamethylene glycol, decamethylene glycol, neopentyl glycol, and 1,4-butadiene glycol.

  Further, in the present invention, the above alcohol monomer is used as a main component, but in addition to the above components, divalent compounds such as polyoxyethylenated bisphenol A, polyoxypropylenated bisphenol A, 1,4-cyclohexanedimethanol and the like. Alcohols such as 1,3,5-trihydroxymethylbenzene, pentaerythritol, dipentaerythritol, tripentaerythritol, 1,2,4-butanetriol, 1,2,5-pentanetriol, glycerin, Trivalent alcohols such as 2-methylpropanetriol, 2-methyl-1,2,4-butanetriol, trimethylolethane, and trimethylolpropane may be used.

  Examples of the carboxylic acid monomer for obtaining the crystalline polyester include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, speric acid, glutaconic acid, azelaic acid, sebacic acid, nonanedicarboxylic acid, Decanedicarboxylic acid, undecanedicarboxylic acid, dodecanedicarboxylic acid, maleic acid, fumaric acid, mesaconic acid, citraconic acid, itaconic acid, isophthalic acid, terephthalic acid, n-dodecyl succinic acid, n-dedecenyl succinic acid, cyclohexanedicarboxylic acid, these Examples include acid anhydrides and lower alkyl esters.

In the present invention, the dicarboxylic acid as described above is used as a main component, but a trivalent or higher polyvalent carboxylic acid may be used in addition to the above components.
Trivalent or higher polyvalent carboxylic acid components include trimellitic acid, 2,5,7-naphthalenetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid, pyromellitic acid, 1,2,4-butanetricarboxylic acid, Examples thereof include 1,2,5-hexanetricarboxylic acid, 1,3-dicarboxyl-2-methyl-2-methylenecarboxypropane, and derivatives such as acid anhydrides or lower alkyl esters thereof.

  The polyester resin of the present invention can be produced by an ordinary polyester synthesis method. For example, after a dicarboxylic acid component and a dial alcohol component are esterified or transesterified, they are subjected to a polycondensation reaction under reduced pressure or by introducing nitrogen gas to obtain a polyester resin.

  In the esterification or transesterification reaction, an ordinary esterification catalyst or transesterification catalyst such as sulfuric acid, titanium butoxide, dibutyltin oxide, manganese acetate, and magnesium acetate can be used as necessary. Regarding polymerization, known polymerization catalysts such as titanium butoxide, dibutyltin oxide, tin acetate, zinc acetate, tin disulfide, antimony trioxide, germanium oxide and the like can be used. The polymerization temperature and the amount of catalyst are not particularly limited, and may be arbitrarily selected as necessary.

Further, in order to adjust the acid value and hydroxyl value of the crystalline polyester, which is an essential requirement of the present invention, it is necessary to seal the hydroxyl group or carboxyl group at the end of the polymer.
Monocarboxylic acid and monoalcohol can be used for end-capping. Examples of monocarboxylic acids include benzoic acid, naphthalenecarboxylic acid, salicylic acid, 4-methylbenzoic acid, 3-methylbenzoic acid, phenoxyacetic acid, biphenylcarboxylic acid, acetic acid, propionic acid, butyric acid, octanoic acid, decanoic acid, dodecanoic acid, And monocarboxylic acids such as stearic acid. As the monoalcohol, methanol, ethanol, propanol, isopropanol, butanol, and higher alcohol can be used.

Only one type of crystalline polyester may be used, or a plurality of types may be used in combination. Furthermore, in addition to the crystalline polyester, an amorphous polyester may be included in the toner.
In the present invention, the crystalline polyester refers to a polyester having an endothermic peak at the time of temperature rise and an exothermic peak at the time of temperature fall in the endothermic curve obtained by differential scanning calorimetry (DSC) measurement. D 3417-99 ".

  The toner of the present invention has one or more release agents, and the melting point (Tm2) of at least one release agent and the melting point (Tm1) of the crystalline polyester satisfy the relationship of Tm2 ≦ Tm1 + 10 ° C. It is preferable that the relationship of Tm2 ≦ Tm1 is satisfied.

  Crystalline polyester is not compatible with binder resin and release agent, and it is generally known that crystalline substances expand in volume when melted. The same applies to release agent and crystalline polyester. there were. Therefore, the melting point (Tm2) of at least one release agent contained in the toner is not higher than the melting point (Tm1) of the crystalline polyester + 10 ° C., that is, Tm2 ≦ Tm1 + 10 ° C. It is considered that the crystalline polyester extrudes the melted release agent, promotes the release of the release agent, and provides good release properties.

  From the viewpoint of achieving both the effect of adding the release agent and the long-term storage stability of the toner, the content is preferably 2 to 30% by mass with respect to the binder resin. If the content of the release agent is less than 2% by mass, the effect of adding the release agent as described above cannot be obtained sufficiently. On the other hand, if it exceeds 30% by mass, the long-term storage stability is deteriorated, and the dispersibility of the toner material such as a release agent, magnetic powder, and pigment is deteriorated, resulting in an increase in fog.

A known release agent can be used for the toner of the present invention. Specifically, petroleum waxes such as paraffin wax, microcrystalline wax, petrolactam and derivatives thereof; montan wax and derivatives thereof; hydrocarbon waxes and derivatives thereof by the Fischer-Tropsch method; polyolefin waxes and derivatives thereof typified by polyethylene; Natural waxes such as carnauba wax and candelilla wax and their derivatives. Here, the derivatives include oxides, block copolymers with vinyl monomers, and graft modified products. Furthermore, fatty acids such as higher aliphatic alcohols, stearic acid and palmitic acid and compounds thereof; acid amide waxes, ester waxes, ketones, hydrogenated castor oil and derivatives thereof; plant waxes; animal waxes and the like can also be used.
These release agents used in the present invention may be of one type or a plurality of types may be used in combination.

  The toner of the present invention contains crystalline polyester, one or more release agents, and a binder resin. Examples of the binder resin used in the present invention include styrene such as polystyrene and polyvinyltoluene, and substitution thereof. Homopolymers: styrene-propylene copolymer, styrene-vinyltoluene copolymer, styrene-vinylnaphthalene copolymer, styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer, styrene-acrylic Acid butyl copolymer, styrene-octyl acrylate copolymer, styrene-dimethylaminoethyl acrylate copolymer, styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, styrene-methacrylic Acid butyl copolymer, styrene-dimethylaminoethyl methacrylate copolymer, styrene -Vinyl methyl ether copolymer, styrene-vinyl ethyl ether copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-maleic acid copolymer, styrene- Styrene copolymers such as maleic acid ester copolymer; polymethyl methacrylate, polybutyl methacrylate, polyvinyl acetate, polyethylene, polypropylene, polyvinyl butyral, silicone resin, polyester resin, polyamide resin, epoxy resin, polyacrylic acid resin These can be used, and these can be used alone or in combination. Of these, styrene copolymers and polyester resins are particularly preferred from the standpoints of development characteristics and fixability.

  In the toner of the present invention, a charge control agent may be blended as necessary to improve charging characteristics. As the charge control agent, a known one can be used, but a charge control agent that has a high charging speed and can stably maintain a constant charge amount is particularly preferable. Further, when the toner is directly produced using a polymerization method as described later, a charge control agent having a low polymerization inhibitory property and substantially free from a solubilized product in an aqueous dispersion medium is particularly preferred. Among charge control agents, as specific compounds of negative charge control agents, metal compounds of aromatic carboxylic acids such as salicylic acid, alkyl salicylic acid, dialkyl salicylic acid, naphthoic acid, dicarboxylic acid; metal salts of azo dyes or azo pigments Or a metal complex; a polymer compound having a sulfonic acid or carboxylic acid group in the side chain; a boron compound; a urea compound; a silicon compound; and a calixarene. Examples of the positive charge control agent include a quaternary ammonium salt, a polymer compound having the quaternary ammonium salt in the side chain, a guanidine compound, a nigrosine compound, and an imidazole compound.

  As a method for adding a charge control agent to the toner, a method of adding the charge control agent to the inside of the toner particles, and in the case of producing the toner by suspension polymerization, the charge control agent is added to the polymerizable monomer composition before granulation. The method is generally used to add seeds by adding a polymerizable monomer in which a charge control agent is dissolved and suspended during polymerization during the formation of oil droplets in water or after polymerization. Polymerization can be performed to uniformly cover the toner surface. In the case where an organometallic compound is used as the charge control agent, it is also possible to introduce the compound by adding these compounds to the toner particles, applying a shear and mixing and stirring.

  The amount of these charge control agents used is determined by the toner production method including the type of binder resin, the presence or absence of other additives, and the dispersion method, and is not uniquely determined. When added internally to the particles, it is preferably in the range of 0.1 to 10 parts by mass, more preferably 0.1 to 5 parts by mass with respect to 100 parts by mass of the binder resin. Further, when externally added to the toner particles, the amount is preferably 0.005 to 1.0 part by mass, more preferably 0.01 to 0.3 part by mass with respect to 100 parts by mass of the toner.

  The toner of the present invention contains a colorant that matches the target color. As the colorant used in the toner of the present invention, any of known organic pigments or dyes, carbon black, magnetic powder, and the like can be used.

  As the cyan colorant, copper phthalocyanine compounds and derivatives thereof, anthraquinone compounds, basic dye lake compounds, and the like can be used. Specifically, C.I. I. Pigment blue 1, C.I. I. Pigment blue 7, C.I. I. Pigment blue 15, C.I. I. Pigment blue 15: 1, C.I. I. Pigment blue 15: 2, C.I. I. Pigment blue 15: 3, C.I. I. Pigment blue 15: 4, C.I. I. Pigment blue 60, C.I. I. Pigment blue 62, C.I. I. And CI Pigment Blue 66.

  As the magenta colorant, condensed azo compounds, diketopyrrolopyrrole compounds, anthraquinones, quinacridone compounds, basic dye lake compounds, naphthol compounds, benzimidazolone compounds, thioindigo compounds, and perylene compounds are used. Specifically, C.I. I. Pigment Red 2, C.I. I. Pigment Red 3, C.I. I. Pigment Red 5, C.I. I. Pigment Red 6, C.I. I. Pigment red 7, C.I. I. Pigment violet 19, C.I. I. Pigment red 23, C.I. I. Pigment red 48: 2, C.I. I. Pigment red 48: 3, C.I. I. Pigment red 48: 4, C.I. I. Pigment red 57: 1, C.I. I. Pigment red 81: 1, C.I. I. Pigment red 122, C.I. I. Pigment red 144, C.I. I. Pigment red 146, C.I. I. Pigment red 166, C.I. I. Pigment red 169, C.I. I. Pigment red 177, C.I. I. Pigment red 184, C.I. I. Pigment red 185, C.I. I. Pigment red 202, C.I. I. Pigment red 206, C.I. I. Pigment red 220, C.I. I. Pigment red 221, C.I. I. And CI Pigment Red 254.

  As the yellow colorant, compounds represented by condensed azo compounds, isoindolinone compounds, anthraquinone compounds, azo metal complexes, methine compounds, and allylamide compounds are used. Specifically, C.I. I. Pigment yellow 12, C.I. I. Pigment yellow 13, C.I. I. Pigment yellow 14, C.I. I. Pigment yellow 15, C.I. I. Pigment yellow 17, C.I. I. Pigment yellow 62, C.I. I. Pigment yellow 74, C.I. I. Pigment yellow 83, C.I. I. Pigment yellow 93, C.I. I. Pigment yellow 94, C.I. I. Pigment yellow 95, C.I. I. Pigment yellow 97, C.I. I. Pigment yellow 109, C.I. I. Pigment yellow 110, C.I. I. Pigment yellow 111, C.I. I. Pigment yellow 120, C.I. I. Pigment yellow 127, C.I. I. Pigment yellow 128, C.I. I. Pigment yellow 129, C.I. I. Pigment yellow 147, C.I. I. Pigment yellow 151, C.I. I. Pigment yellow 154, C.I. I. Pigment yellow 168, C.I. I. Pigment yellow 174, C.I. I. Pigment yellow 175, C.I. I. Pigment yellow 176, C.I. I. Pigment yellow 180, C.I. I. Pigment yellow 181, C.I. I. Pigment yellow 191, C.I. I. And CI Pigment Yellow 194.

  These colorants can be used singly or in combination of two or more, and also in a solid solution state. The colorant used in the toner of the present invention is appropriately selected from the viewpoints of hue angle, saturation, brightness, light resistance, OHP transparency, and dispersibility in the toner. Further, the addition amount of the colorant is preferably 1 to 20 parts by mass with respect to 100 parts by mass of the binder resin.

  Further, as the black colorant, carbon black, magnetic powder, and a color toned to black using the yellow / magenta / cyan colorant are used. When carbon black is used as the black colorant, the addition amount is preferably 1 to 20 parts by mass with respect to 100 parts by mass of the binder resin.

  When the toner of the present invention is used as a magnetic toner, magnetic powder can be used as a colorant. When magnetic powder is used as the black colorant, the magnetic powder is preferably used in an amount of 20 to 150 parts by mass with respect to 100 parts by mass of the binder resin. When the added amount of the magnetic powder is less than 20 parts by mass, the fixability is improved, but the coloring power of the toner is poor and fogging is difficult to suppress. On the other hand, if the amount exceeds 150 parts by mass, the fixability is deteriorated and the holding force by the magnetic force of the toner carrier is increased, so that the developability may be deteriorated.

  The content of the magnetic powder in the toner can be measured using a thermal analyzer TGA7 manufactured by PerkinElmer. The measurement method is as follows: the toner is heated from room temperature to 900 ° C. at a temperature increase rate of 25 ° C./min in a nitrogen atmosphere; The mass is approximately the amount of magnetic powder.

  In the present invention, when a toner is produced using a polymerization method, it is necessary to pay attention to the polymerization inhibition property and water phase transfer property of the colorant. Therefore, the colorant is preferably subjected to surface modification, for example, a hydrophobic treatment with a substance that does not inhibit polymerization. In particular, since dyes and carbon black have many polymerization-inhibiting properties, care must be taken when using them.

  About carbon black, you may process with the substance which reacts with the surface functional group of carbon black, for example, polyorganosiloxane.

When magnetic powder is used in the toner of the present invention, the magnetic powder is mainly composed of magnetic iron oxide such as triiron tetroxide and γ-iron oxide, and phosphorus, cobalt, nickel, copper, magnesium, Elements such as manganese, aluminum, and silicon may be included. These magnetic powders is preferably a BET specific surface area by nitrogen adsorption method is 2~30m ² / g, more preferably 3~28m ² / g. Further, those having a Mohs hardness of 5 to 7 are preferred. The shape of the magnetic powder includes polyhedron, octahedron, hexahedron, spherical shape, needle shape, flake shape, etc., but those having low anisotropy such as polyhedron, octahedron, hexahedron, spherical shape, etc. It is preferable for increasing the ratio.

  The magnetic powder preferably has a volume average particle size of 0.10 to 0.40 μm. In general, the smaller the particle size of the magnetic powder, the higher the coloring power, but the magnetic powder tends to aggregate, and the uniform dispersibility of the magnetic powder in the toner is inferior. In addition, when the volume average particle size is 0.10 μm or less, the magnetic powder itself becomes reddish black, so that the image becomes particularly reddish in a halftone image, which is not preferable because it is not a high-quality image. . On the other hand, when the volume average particle size is 0.40 μm or more, the coloring power of the toner is insufficient, and in the suspension polymerization method (described later) which is a preferable method for producing the toner of the present invention, uniform dispersion becomes difficult.

  The volume average particle size of the magnetic powder can be measured using a transmission electron microscope. Specifically, after sufficiently dispersing toner particles to be observed in an epoxy resin, a cured product obtained by curing for 2 days in an atmosphere at a temperature of 40 ° C. is used as a flaky sample by a microtome. In an electron microscope (TEM), 100 magnetic powder particle diameters in the field of view are measured with a photograph with an enlargement magnification of 10,000 to 40,000 times. Then, the volume average particle diameter is calculated based on the equivalent diameter of a circle equal to the projected area of the magnetic powder. It is also possible to measure the particle size with an image analyzer.

  The magnetic powder used for the toner of the present invention can be produced, for example, by the following method. An aqueous solution containing ferrous hydroxide is prepared by adding an alkali such as sodium hydroxide in an amount equivalent to or greater than the iron component to the ferrous salt aqueous solution. Air was blown in while maintaining the pH of the prepared aqueous solution at pH 7 or higher, and ferrous hydroxide was oxidized while heating the aqueous solution to 70 ° C. or higher. First, seed crystals serving as the core of the magnetic iron oxide powder were formed. Generate.

  Next, an aqueous solution containing about 1 equivalent of ferrous sulfate is added to the slurry-like liquid containing seed crystals based on the amount of alkali added previously. While maintaining the pH of the solution at 5 to 10, the reaction of ferrous hydroxide proceeds while blowing air to grow a magnetic iron oxide powder with the seed crystal as a core. At this time, it is possible to control the shape and magnetic properties of the magnetic powder by selecting an arbitrary pH, reaction temperature, and stirring conditions. As the oxidation reaction proceeds, the pH of the liquid shifts to the acidic side, but the pH of the liquid is preferably not less than 5. A magnetic powder can be obtained by filtering, washing, and drying the magnetic material thus obtained by a conventional method.

  In the present invention, when the toner is produced by a polymerization method, it is very preferable to subject the surface of the magnetic powder to a hydrophobic treatment. When the surface treatment is performed by a dry method, the coupling agent treatment is performed on the magnetic powder that has been washed, filtered, and dried. When wet surface treatment is performed, after the oxidation reaction is completed, the dried material is redispersed, or after completion of the oxidation reaction, the iron oxide powder obtained by washing and filtering is not dried, but another aqueous medium. Add the silane coupling agent while stirring the re-dispersed liquid sufficiently, increase the temperature after hydrolysis, or adjust the pH of the dispersion to the alkaline range after hydrolysis. It can also be done. Among these, from the viewpoint of performing a uniform surface treatment, it is preferable to carry out the surface treatment by reslurry as it is without drying after filtration and washing after completion of the oxidation reaction.

  In order to treat the surface of the magnetic powder wet, that is, to treat the magnetic powder with a coupling agent in an aqueous medium, first, the magnetic powder is sufficiently dispersed in the aqueous medium to have a primary particle size, and then settled. Stir with a stirring blade to prevent aggregation. Next, an arbitrary amount of coupling agent is added to the above dispersion, and the surface treatment is performed while hydrolyzing the coupling agent. At this time, the dispersion is sufficiently dispersed so as not to aggregate while using a device such as a pin mill or a line mill. More preferably, the surface treatment is carried out.

  Here, the aqueous medium is a medium containing water as a main component. Specific examples include water itself, water added with a small amount of surfactant, water added with a pH adjusting agent, and water added with an organic solvent. As the surfactant, nonionic surfactants such as polyvinyl alcohol are preferable. It is preferable to add the surfactant in an amount of 0.1 to 5.0% by mass with respect to water. Examples of the pH adjusting agent include inorganic acids such as hydrochloric acid. Examples of the organic solvent include alcohols.

Examples of the coupling agent that can be used in the surface treatment of the magnetic powder in the present invention include a silane coupling agent and a titanium coupling agent. More preferably used is a silane coupling agent, which is represented by the general formula (I).
R _m SiY _n (I)
[Wherein, R represents an alkoxy group, m represents an integer of 1 to 3, Y represents a functional group such as an alkyl group, a vinyl group, an epoxy group, or a (meth) acryl group, and n represents 1 to 3] Indicates an integer. However, m + n = 4. ]

  Examples of the silane coupling agent represented by the general formula (I) include vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris (β-methoxyethoxy) silane, β- (3,4 epoxy cyclohexyl) ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-aminopropyltriethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, Vinyltriacetoxysilane, methyltrimethoxysilane, dimethyldimethoxysilane, phenyltrimethoxysilane, diphenyldimethoxysilane, methyltriethoxysilane, dimethyldiethoxysilane, phenyltriethoxysilane, diphenyl Diethoxysilane, n-butyltrimethoxysilane, isobutyltrimethoxysilane, trimethylmethoxysilane, n-hexyltrimethoxysilane, n-octyltrimethoxysilane, n-octyltriethoxysilane, n-decyltrimethoxysilane, hydroxypropyl Examples include trimethoxysilane, n-hexadecyltrimethoxysilane, and n-octadecyltrimethoxysilane.

Among these, from the viewpoint of imparting high hydrophobicity to the magnetic powder, it is preferable to use an alkyltrialkoxysilane coupling agent represented by the following general formula (II).
_{C p H 2p + 1 -Si- (} OC q H 2q + 1) 3 (II)
[In formula, p shows the integer of 2-20, q shows the integer of 1-3. ]

  When p in the above formula is smaller than 2, it is difficult to sufficiently impart hydrophobicity to the magnetic powder, and when p is larger than 20, hydrophobicity is sufficient. It is unfavorable because it increases. Further, when q is larger than 3, the reactivity of the silane coupling agent is lowered and the hydrophobicity is not sufficiently performed. Therefore, p in the formula is an integer of 2 to 20 (more preferably, an integer of 3 to 15). It is preferable to use an alkyltrialkoxysilane coupling agent in which q is an integer of 1 to 3 (more preferably an integer of 1 or 2).

  When using the said silane coupling agent, it is possible to process independently or to process in combination of several types. When using several types together, you may process separately with each coupling agent, and may process simultaneously.

  The total amount of the coupling agent used is preferably 0.9 to 3.0 parts by mass with respect to 100 parts by mass of the magnetic powder, and the treatment is performed according to the surface area of the magnetic powder, the reactivity of the coupling agent, and the like. It is important to adjust the amount of agent.

  In the present invention, other colorants may be used in combination with the magnetic powder. Examples of the colorant that can be used in combination include magnetic or nonmagnetic inorganic compounds in addition to the above-described known dyes and pigments. Specifically, ferromagnetic metal particles such as cobalt and nickel; or alloys obtained by adding chromium, manganese, copper, zinc, aluminum, rare earth elements, etc .; particles such as hematite, titanium black, nigrosine dye / pigment, carbon Examples thereof include black and phthalocyanine. These are also preferably used by treating the surface.

  The toner of the present invention has a main peak peak top in the molecular weight range of 5,000 to 50,000 in the molecular weight distribution measured by gel permeation chromatography (GPC) of the THF (tetrahydrofuran) soluble content of the toner. It is preferable that the peak top be present in the range of 7,000 to 40,000. When the peak top is less than 5,000, there is a problem in the storage stability of the toner, or the toner is remarkably deteriorated after long-term use. On the other hand, when the peak top is in a range exceeding 50,000, the low-temperature fixability is deteriorated.

  The resin component of the toner of the present invention preferably has a THF-insoluble content, and the amount thereof is 5 to 65% by mass with respect to the resin component of the toner. If the THF-insoluble content is less than 5%, the low-temperature fixability is good, but high-temperature offset tends to occur, which is not preferable. On the other hand, if the THF-insoluble content is more than 65%, exudation of the release agent component is inhibited at the time of fixing, and the toner is difficult to be plastically deformed and it is difficult to obtain good low-temperature fixability.

The THF insoluble content of the resin component of the toner is measured as follows. Toner particles or 1 g of toner are precisely weighed and charged into a cylindrical filter paper, and Soxhlet extracted with 200 ml of THF for 20 hours. Thereafter, the cylindrical filter paper is taken out and vacuum-dried at 40 ° C. for 20 hours, and then the residue mass is measured. The THF-insoluble matter is calculated from the following formula. The resin component of the toner is a component obtained by removing the magnetic powder, pigment, charge control agent, release agent component, external additive and the like from the toner. Taking into account whether it is soluble or insoluble, the THF-insoluble matter based on the resin component is calculated.
THF insoluble matter (%) = (W2-W3) / (W1-W3-W4) × 100
(W1 is the mass of the toner, W2 is the mass of the residue, W3 is the mass of the component insoluble in THF other than the resin component of the toner, and W4 is the mass of the component soluble in THF other than the resin component of the toner. Show.)

  The molecular weight of the THF soluble part of the toner and the amount of the THF insoluble part of the resin component of the toner can be determined by appropriately selecting the binder resin to be used and the kneading conditions when the toner is produced by the pulverization method. In the case of producing a toner, it can be arbitrarily changed by appropriately selecting the combination of the type and amount of the polymerization initiator and the crosslinking agent to be used. It can also be adjusted by using a chain transfer agent or the like.

  The glass transition temperature (Tg) of the toner of the present invention is preferably 40 to 70 ° C. When the glass transition temperature is less than 40 ° C., the storage stability is lowered, and the toner is liable to deteriorate during long-term use. Therefore, the glass transition temperature of the toner is preferably 40 to 70 ° C. in consideration of the balance between fixability, storage stability and developability.

  The toner of the present invention preferably has a weight average particle diameter of 3 to 12 μm, more preferably 4 to 9 μm in order to faithfully develop finer latent image dots in order to achieve high image quality. is there. When the weight average particle diameter is less than 3 μm, the fluidity and agitation as a powder decrease, and it becomes difficult to uniformly charge individual toner particles. Furthermore, the smaller the particle size, the more difficult it is to obtain a uniform dispersion of the mold release agent and the crystalline polyester, which tends to cause an increase in fog and the like. On the other hand, if the weight average particle diameter is larger than 12 μm, the fog is improved, but it is difficult to improve the image quality as described above, and the fixability is deteriorated.

  The toner of the present invention preferably has an average circularity of 0.960 or more because fogging is reduced and low-temperature fixability is improved. This is because when the average circularity of the toner is 0.960 or more, that is, when the shape of the toner is spherical or close to it, the toner is excellent in fluidity, so that uniform triboelectric chargeability is easily obtained. It is thought to reduce.

  Further, it is considered that the spherical toner is densely packed on a medium such as paper. In the fixing process, the toner is not only anchored to the paper but also fused with other toner particles, and the spherical toner that is closely packed is also advantageous in this respect. It is considered that the fixing property is greatly improved by a synergistic effect with the use of. In the circularity distribution of the toner, when the mode circularity is 0.98 or more, the above action becomes more remarkable, which is more preferable.

The toner of the present invention preferably has a core-shell structure in order to improve storage stability and developability. This is because by having the shell layer, the surface property of the toner becomes uniform, the fluidity improves, and the charging property becomes uniform.
Further, since the high molecular weight shell uniformly covers the surface layer, the release agent does not ooze out even during long-term storage, and storage stability is improved.

  Therefore, it is preferable to use an amorphous high molecular weight material for the shell layer, and from the viewpoint of charging stability, the acid value is preferably 5.0 to 20.0 mgKOH / g. When the acid value of the high molecular weight substance used for the shell layer is larger than 20.0 mgKOH / g, the chargeability of the toner is adversely affected and the developability in a high temperature and high humidity environment is deteriorated. On the other hand, when the acid value of the high molecular weight substance used in the shell layer is less than 5.0 mgKOH / g, it is easy to be compatible with the crystalline polyester, and the storage stability is inferior, which is not preferable.

  As a specific method for forming the shell, the core particles are embedded with fine particles for shells, or in the production method in an aqueous medium, which is a preferred method for producing the toner of the present invention, the core particles are made of superfine shells. It is possible to form a shell layer by attaching fine particles and drying. In addition, in the suspension suspension method and suspension polymerization method, the acid value and hydrophilicity of the high molecular weight polymer for the shell are utilized to make the shell unevenly distributed at the interface with water, that is, near the toner surface. It is possible to do. Furthermore, a shell can be formed by infiltrating a monomer on the surface of the core particle and polymerizing by a so-called seed polymerization method.

  Examples of the high molecular weight material for the shell layer include styrene such as polystyrene and polyvinyltoluene, and homopolymers of substituted styrene; styrene-propylene copolymer, styrene-vinyltoluene copolymer, styrene-vinylnaphthalene copolymer, Styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer, styrene-butyl acrylate copolymer, styrene-octyl acrylate copolymer, styrene-dimethylaminoethyl acrylate copolymer, styrene-meta Methyl acrylate copolymer, styrene-ethyl methacrylate copolymer, styrene-butyl methacrylate copolymer, styrene-dimethylaminoethyl methacrylate copolymer, styrene-vinyl methyl ether copolymer, styrene-vinyl Ethyl ether copolymer, styrene Styrene copolymers such as vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-maleic acid copolymer, styrene-maleic acid ester copolymer; polymethyl methacrylate, poly Butyl methacrylate, polyvinyl acetate, polyethylene, polypropylene, polyvinyl butyral, silicone resin, polyester resin, styrene-polyester copolymer, poly (meth) acrylate-polyester copolymer, polyamide resin, epoxy resin, polyacrylic acid resin, terpene There exist resin, a phenol resin, etc., These can be used individually or in mixture of 2 or more types. Moreover, you may introduce | transduce functional groups, such as an amino group, a carboxyl group, a hydroxyl group, a sulfonic acid group, a glycidyl group, a nitrile group, in these polymers.

  As addition amount of these resin, 1-30 mass parts is preferable in total with respect to 100 mass parts of polymerizable monomers. If the amount is less than 1 part by mass, the effect of addition is small.

Among these resins, polyester is particularly preferable because it exhibits the above effect.
As the polyester resin used in the present invention, a saturated polyester resin, an unsaturated polyester resin, or both can be appropriately selected.
The polyester resin used for this invention is a normal thing comprised from the alcohol component and an acid component, and both components are illustrated below.

［式中、Ｒはエチレンまたはプロピレン基であり、ｘ，ｙはそれぞれ１以上の整数であり、かつｘ＋ｙの平均値は２〜１０である。］、あるいは式（Ｉ）の化合物の水添物、
また、式（ＩＩ）で示されるジオール；

、あるいは式（ＩＩ）の化合物の水添物のジオールが挙げられる。 As alcohol components, ethylene glycol, propylene glycol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, diethylene glycol, triethylene glycol, 1,5-pentanediol, 1,6-hexane Diol, neopentyl glycol, 2-ethyl-1,3-hexanediol, cyclohexanedimethanol, butenediol, octenediol, cyclohexenedimethanol, hydrogenated bisphenol A, and bisphenol derivatives represented by formula (I);

[Wherein, R is an ethylene or propylene group, x and y are each an integer of 1 or more, and the average value of x + y is 2 to 10. Or hydrogenated compounds of the formula (I),
A diol represented by the formula (II);

Or diols of hydrogenated compounds of the formula (II).

  Divalent carboxylic acids include benzene dicarboxylic acids such as phthalic acid, terephthalic acid, isophthalic acid, and phthalic anhydride or anhydrides thereof; alkyl dicarboxylic acids such as succinic acid, adipic acid, sebacic acid, and azelaic acid, or anhydrides thereof; Furthermore, succinic acid substituted with an alkyl or alkenyl group having 6 to 18 carbon atoms or an anhydride thereof; unsaturated dicarboxylic acid such as fumaric acid, maleic acid, citraconic acid, itaconic acid or the anhydride thereof may be used.

  In addition, polyhydric alcohols such as glycerin, pentaerythritol, sorbit, sorbitan, and oxyalkylene ethers of novolac type phenol resins can be cited as the alcohol component, and trimellitic acid, pyromellitic acid, 1,2,3,4- Examples thereof include polyvalent carboxylic acids such as butanetetracarboxylic acid, benzophenonetetracarboxylic acid and anhydrides thereof.

  Among the polyester resins, the alkylene oxide adduct of bisphenol A, which is excellent in charging characteristics and environmental stability and balanced in other electrophotographic characteristics, is preferably used. In the case of this compound, the average number of added moles of alkylene oxide is preferably 2 to 10 in terms of fixability and toner durability.

  It is preferable that 45-55 mol% of the polyester resin in this invention is an alcohol component, and 55-45 mol% is an acid component in all the components.

  The number average molecular weight of the high molecular weight body forming the shell is preferably 2500 to 10,000. A number average molecular weight of 2500 or less is not preferable because developability, blocking resistance, and durability tend to deteriorate. On the other hand, if the number average molecular weight exceeds 10,000, the developability and durability are improved, but the low-temperature fixability is deteriorated. The number average molecular weight can be measured by the GPC described above.

  The toner of the present invention comprises toner particles containing at least a binder resin, a crystalline polyester, and a release agent, and additives such as inorganic fine powder added to the toner particles as necessary. The toner of the present invention can be produced by any known method. First, when producing by a pulverization method, for example, a binder resin, a colorant, a crystalline polyester, a release agent, a charge control agent and other necessary components and other additives are added to a Henschel mixer, a ball mill, etc. Mix thoroughly with a mixer, then melt and knead using a heat kneader such as a heated roll, kneader, or extruder to disperse or dissolve the toner material, cool and solidify, grind, classify, and surface treatment as necessary To obtain toner particles. Either the classification or the surface treatment may be performed first. In the classification step, it is preferable to use a multi-division classifier in terms of production efficiency.

  However, when the toner is manufactured by such a pulverization method, the relationship between Tm1 and Tfb varies depending on the kneading conditions and the like, and thus satisfies the condition of Tm1 ≦ Tfb ≦ Tm1 + 12 [° C.], which is an essential requirement of the present invention. As such, manufacturing conditions and the like must be selected. Specifically, when melt-kneading at a high temperature, the crystalline polyester becomes compatible with the binder resin, and Tfb falls below Tm1. On the other hand, when melt-kneading at a low temperature without applying a share, the dispersibility of the crystalline polyester becomes poor, and Tfb becomes higher than Tm1 + 12 ° C. Therefore, in order to obtain a toner satisfying the relationship of Tm1 ≦ Tfb ≦ Tm1 + 12 [° C.], which is an essential constituent element of the present invention, the crystalline polyester is finely pulverized and then mixed with other toner materials, and the share is applied at a low temperature. It is preferable to melt and knead.

  The pulverization step can be performed by a method using a known pulverizer such as a mechanical impact type or a jet type. Further, in order to obtain a toner having a preferable circularity (0.960 or more) of the present invention, it is preferable to further pulverize by applying heat or to perform an auxiliary mechanical shock treatment. Further, a hot water bath method in which finely pulverized (classified as necessary) toner particles are dispersed in hot water, a method of passing in a hot air stream, or the like may be used.

  As a method of applying mechanical impact force, for example, a method using a mechanical impact type pulverizer such as a kryptron system manufactured by Kawasaki Heavy Industries, Ltd. or a turbo mill manufactured by Turbo Industry, a mechano-fusion system manufactured by Hosokawa Micron Co., Ltd., or Nara Machinery Co., Ltd. There is a method of applying a mechanical impact force to the toner by a force such as a compressive force or a frictional force by pressing the toner against the inside of the casing by a centrifugal force with a blade rotating at high speed, as in a device such as a hybridization system manufactured by the manufacturer.

  The toner of the present invention can also be produced by a pulverization method as described above. However, toner particles obtained by this pulverization method are generally irregular in shape, and an average circularity suitable for the present invention is 0.00. In order to obtain a physical property of 960 or more, it is necessary to perform mechanical / thermal or some special treatment, resulting in poor productivity. Therefore, the toner of the present invention is preferably produced in an aqueous medium by a dispersion polymerization method, an association aggregation method, a dissolution suspension method, a suspension polymerization method, and the like. It is easy to fill and very preferable.

  In the suspension polymerization method, a polymerizable monomer and a colorant (in addition, a polymerization initiator, a crosslinking agent, a charge control agent, and other additives as necessary) are uniformly dissolved or dispersed to form a polymerizable monomer. After preparing the composition, the polymerizable monomer composition is dispersed in a continuous layer containing a dispersion stabilizer (for example, an aqueous phase) using an appropriate stirrer, and simultaneously subjected to a polymerization reaction to obtain a desired particle size. A toner having the above is obtained. Since the toner obtained by this suspension polymerization method (hereinafter also referred to as “polymerized toner”) has individual toner particle shapes that are substantially spherical, the physical property requirement suitable for the present invention is an average circularity of 0.960 or more. It is easy to obtain a toner that satisfies the requirements. Furthermore, since the toner has a relatively uniform charge amount distribution, an improvement in image quality can be expected.

  A method for producing toner by suspension polymerization will be described below. Suspension polymerization toner is generally a component necessary as a toner such as a colorant, a crystalline polyester, a release agent, a charge control agent, and a crosslinking agent in a polymerizable monomer constituting a toner composition, that is, a binder resin. And other additives such as a polymer, a dispersant and the like, and an aqueous medium containing a dispersion stabilizer containing a polymerizable monomer composition that is uniformly dissolved or dispersed by a disperser or the like It can be produced by suspending in it and polymerizing it.

In the production of the polymerized toner according to the present invention, examples of the polymerizable monomer constituting the polymerizable monomer composition include the following.
Examples of the polymerizable monomer include styrene monomers such as styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, p-methoxystyrene, and p-ethylstyrene; methyl acrylate, ethyl acrylate, Acrylate esters such as n-butyl acrylate, isobutyl acrylate, n-propyl acrylate, n-octyl acrylate, dodecyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, 2-chloroethyl acrylate, and phenyl acrylate , Methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-octyl methacrylate, dodecyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, phenyl methacrylate, Methacrylic acid dimethyl aminoethyl, methacrylic acid esters such as diethylaminoethyl methacrylate; and other acrylonitrile, methacrylonitrile, and the like monomers acrylamide. These monomers can be used alone or in combination. Among the above-mentioned monomers, styrene or a styrene derivative is preferably used alone or mixed with other monomers from the viewpoint of developing characteristics and durability of the toner.

  As a polymerization initiator used in the production of the toner of the present invention by a polymerization method, a polymerization initiator having a half-life of 0.5 to 30 hours in a polymerization reaction is 0.5 to 20 mass based on a polymerizable monomer. When the polymerization reaction is carried out using a part addition amount, a polymer having a maximum between 5,000 and 50,000 in molecular weight can be obtained, and the toner can be provided with desirable strength and suitable melting characteristics.

  Specific examples of the polymerization initiator include 2,2′-azobis- (2,4-dimethylvaleronitrile), 2,2′-azobisisobutyronitrile, 1,1′-azobis (cyclohexane-1- Carbonitrile), 2,2′-azobis-4-methoxy-2,4-dimethylvaleronitrile, azo or isoazo polymerization initiators such as azobisisobutyronitrile, benzoyl peroxide, methyl ethyl ketone peroxide, diisopropyl peroxide Peroxide polymerization initiators such as oxycarbonate, cumene hydroperoxide, 2,4-dichlorobenzoyl peroxide, lauroyl peroxide, t-butylperoxy 2-ethylhexanoate, t-butylperoxypivalate, etc. Can be mentioned.

  When the toner of the present invention is produced by a polymerization method, a crosslinking agent may be added, and a preferable addition amount is 0.001 to 15% by mass with respect to 100 parts by mass of the polymerizable monomer.

  Here, as the crosslinking agent, a compound having two or more polymerizable double bonds is mainly used, for example, an aromatic divinyl compound such as divinylbenzene, divinylnaphthalene, etc .; for example, ethylene glycol diacrylate, ethylene glycol diester Carboxylic acid ester having two double bonds such as methacrylate, 1,3-butanediol dimethacrylate, etc .; Divinyl compounds such as divinylaniline, divinyl ether, divinyl sulfide, divinyl sulfone, etc .; and having three or more vinyl groups Are used alone or as a mixture of two or more.

  In the method for producing the toner of the present invention by a polymerization method, generally, the above-described toner composition or the like is appropriately added, and uniformly dissolved or dispersed by a dispersing machine such as a homogenizer, a ball mill, a colloid mill, or an ultrasonic dispersing machine. The polymerizable monomer composition is suspended in an aqueous medium containing a dispersion stabilizer. At this time, the particle size of the obtained toner particles becomes sharper by using a high-speed disperser such as a high-speed stirrer or an ultrasonic disperser to obtain a desired toner particle size at a stretch. The polymerization initiator may be added at the same time as other additives are added to the polymerizable monomer, or may be mixed immediately before being suspended in the aqueous medium. Also, a polymerization initiator dissolved in a polymerizable monomer or solvent can be added immediately after granulation and before starting the polymerization reaction. After granulation, stirring may be performed using a normal stirrer to such an extent that the particle state is maintained and particle floating and sedimentation are prevented.

  When the toner of the present invention is produced, known surfactants, organic dispersants and inorganic dispersants can be used as the dispersion stabilizer. In particular, inorganic dispersants are less likely to produce harmful ultrafine powders, and because of their steric hindrance, dispersion stability is obtained, so even if the reaction temperature is changed, stability is not easily lost, and washing is easy and does not adversely affect the toner. Therefore, it can be preferably used. Examples of such inorganic dispersants include tricalcium phosphate, magnesium phosphate, aluminum phosphate, zinc phosphate, phosphate polyvalent metal salts such as hydroxyapatite, carbonates such as calcium carbonate and magnesium carbonate, calcium metasuccinate, calcium sulfate, Examples thereof include inorganic salts such as barium sulfate and inorganic compounds such as calcium hydroxide, magnesium hydroxide, and aluminum hydroxide.

  As for these inorganic dispersing agents, it is desirable to use 0.2-20 mass parts with respect to 100 mass parts of polymerizable monomers. Moreover, the said dispersion stabilizer may be used independently and may use multiple types together. Furthermore, you may use 0.001-0.1 mass part surfactant together.

  When these inorganic dispersants are used, they may be used as they are, but in order to obtain finer particles, the inorganic dispersant particles can be generated and used in an aqueous medium. For example, in the case of tricalcium phosphate, a sodium phosphate aqueous solution and a calcium chloride aqueous solution can be mixed under high-speed stirring to produce water-insoluble calcium phosphate, which enables more uniform and fine dispersion. At the same time, water-soluble sodium chloride salt is produced as a by-product. However, if water-soluble salt is present in the aqueous medium, dissolution of the polymerizable monomer in water is suppressed, and ultrafine toner is generated by emulsion polymerization. This is more convenient.

  Examples of the surfactant include sodium dodecylbenzene sulfate, sodium tetradecyl sulfate, sodium pentadecyl sulfate, sodium octyl sulfate, sodium oleate, sodium laurate, sodium stearate, potassium stearate and the like.

  In the step of polymerizing the polymerizable monomer, the polymerization temperature is set to 40 ° C. or higher, generally 50 to 90 ° C. When the polymerization is carried out in this temperature range, the release agent to be sealed inside precipitates by phase separation, and the encapsulation becomes more complete. Moreover, it is preferable to raise the reaction temperature to the melting point of the crystalline polyester or higher when the conversion rate of the polymerizable monomer is 50 to 100%. This is presumably because when the toner is produced by the suspension polymerization method, the crystalline polyester forms domains inside the toner particles or exists in a finely dispersed state. Therefore, when the temperature is raised above the melting point of the crystalline polyester, the crystalline polyester finely dispersed in the toner forms a proper domain. As a result, the effects described so far are more suitably exhibited, and it is possible to satisfy the relationship of Tm1 ≦ Tfb ≦ Tm1 + 12 [° C.], which is an essential requirement of the present invention. Furthermore, the crystalline polyester that has not been able to form crystals properly during polymerization of the polymerizable monomer can be raised in crystallinity by raising the temperature to the melting point or higher, and it is difficult for toner deterioration and fusion to occur even in long-term use. Become.

  After the polymerization of the polymerizable monomer is completed, the obtained polymer particles are filtered, washed and dried by a known method to obtain toner particles. The toner of the present invention can be obtained by mixing the toner particles with inorganic fine powder as will be described later, if necessary, and adhering them to the surface of the toner particles. It is also possible to insert a classification step in the manufacturing process (before mixing the inorganic fine powder) to cut coarse powder and fine powder contained in the toner particles.

  In the present invention, an inorganic fine powder having a number average primary particle size of 4 to 80 nm, more preferably 6 to 40 nm, is added to the toner particles as a fluidizing agent. Inorganic fine powder is added to improve toner fluidity and charge uniformity of toner particles. By adjusting the inorganic fine powder to hydrophobic treatment, it is possible to adjust the toner charge amount and improve environmental stability. This is also a preferred form of the present invention.

  When the number average primary particle size of the inorganic fine powder is larger than 80 nm, or when the inorganic fine powder of 80 nm or less is not added, good toner fluidity cannot be obtained, and charge imparting to the toner particles is not possible. Non-uniformity is likely to occur, and problems such as an increase in fog, a decrease in image density, and an increase in consumption are likely to occur. On the other hand, when the number average primary particle size of the inorganic fine powder is smaller than 4 nm, the fineness of the inorganic fine powder becomes stronger, and the particle size distribution has strong cohesiveness that is difficult to break even by crushing treatment instead of the primary particles. It is not preferable because the aggregate easily participates in development, and the image defect is liable to be caused by damaging the image carrier or the toner carrier.

  In the present invention, the number average primary particle size of the inorganic fine powder is determined by using a photograph of the toner magnified with a scanning electron microscope and further using an elemental analysis means such as XMA attached to the scanning electron microscope. Measure 100 or more primary particles of inorganic fine powder adhering to the toner surface or free from the toner particle surface while contrasting the photograph of the toner mapped with the contained element. It can be measured by determining the average primary particle size, that is, the number average primary particle size.

Silica, titanium oxide, alumina, etc. can be used as the inorganic fine powder used in the present invention. As the fine silica powder, for example, both a so-called dry method produced by vapor phase oxidation of silicon halide or dry silica called fumed silica, and so-called wet silica produced from water glass or the like can be used. However, dry silica is preferred because it has few silanol groups on the surface and inside of the silica fine powder, and few production residues such as Na ₂ O and SO ₃ ²⁻ . Further, in dry silica, it is also possible to obtain a composite fine powder of silica and other metal oxides by using other metal halides such as aluminum chloride and titanium chloride together with silicon halides in the production process, They are also included in dry silica.

  The addition amount of the inorganic fine powder having a number average primary particle size of 4 to 80 nm is preferably 0.1 to 3.0% by mass with respect to the toner particles. The effect is not sufficient, and if it is 3.0% by mass or more, the fixability becomes worse. The content of the inorganic fine powder can be quantified using a calibration curve prepared from a standard sample using fluorescent X-ray analysis.

  In the present invention, the inorganic fine powder is preferably a hydrophobized product because the environmental stability of the toner can be improved. When the inorganic fine powder added to the toner absorbs moisture, the charge amount of the toner particles is remarkably reduced, the charge amount is likely to be non-uniform, and toner scattering is likely to occur. Treatment agents used for hydrophobizing inorganic fine powders include silicone varnishes, various modified silicone varnishes, silicone oils, various modified silicone oils, silane compounds, silane coupling agents, other organic silicon compounds, and organic titanium compounds. May be used alone or in combination of two or more.

  Among the above-mentioned treatment agents, those treated with silicone oil are preferable, and more preferably, toner particles treated with silicone oil at the same time as or after hydrophobizing inorganic fine powder with a silane compound are used even in a high humidity environment. It is preferable to keep the charge amount of toner high and prevent toner scattering. As a method for treating such inorganic fine powder, for example, as a first-stage reaction, a silanization reaction is performed with a silane compound and silanol groups are eliminated by chemical bonds, and then a hydrophobic reaction is performed on the surface with silicone oil as a second-stage reaction. The method for forming the thin film can be applied.

The silicone oil may have a viscosity at 25 ° C. is 10~200,000mm ² / s, more preferably from 3,000~80,000mm ² / s. When the viscosity of the silicone oil is less than 10 mm ² / s, the treated inorganic fine powder lacks stability and tends to cause image quality degradation due to heat and mechanical stress. In addition, when the viscosity of the silicone oil exceeds 200,000 mm ² / s, it tends to be difficult to uniformly treat the inorganic fine powder.

  As the silicone oil used, for example, dimethyl silicone oil, methylphenyl silicone oil, α-methylstyrene modified silicone oil, chlorophenyl silicone oil, fluorine modified silicone oil and the like are particularly preferable.

  Examples of the method for treating the inorganic fine powder with silicone oil include a method of directly mixing the inorganic fine powder treated with the silane compound and the silicone oil using a mixer such as a Henschel mixer, or a method of treating the inorganic fine powder with the silicone oil. The method of spraying is mentioned. Alternatively, after dissolving or dispersing silicone oil in an appropriate solvent, an inorganic fine powder may be added and mixed to remove the solvent. A spraying method is more preferred because it produces relatively few aggregates of inorganic fine powder.

  The treatment amount of the silicone oil is preferably 1 to 40 parts by mass, more preferably 3 to 35 parts by mass with respect to 100 parts by mass of the inorganic fine powder. If the amount of silicone oil is too small, good hydrophobicity cannot be obtained, and if it is too large, problems such as fogging tend to occur.

In order to impart good fluidity to the toner, the inorganic fine powder used in the present invention preferably has a specific surface area measured by the BET method by nitrogen adsorption in the range of ²⁰ to 350 m ² / g, preferably 25 to 300 m. More preferable is ² / g. The specific surface area is calculated using the BET multipoint method by adsorbing nitrogen gas to the sample surface using a specific surface area measuring device Autosorb 1 (manufactured by Yuasa Ionics) according to the BET method.

In the present invention, for the purpose of improving cleaning properties, the primary particle size exceeds 30 nm (preferably the specific surface area is less than 50 m ² / g), more preferably the primary particle size is 50 nm or more (preferably the specific surface area is 30 m ^2). It is also one of preferable modes to add inorganic or organic fine particles close to spherical shape (less than / g) to the toner particles. As such fine particles, for example, spherical silica particles, spherical polymethylsilsesquioxane particles, spherical resin particles and the like are preferably used.

  In the toner of the present invention, other additives within a range that does not have a substantial adverse effect, for example, a lubricant powder such as fluororesin powder, zinc stearate powder, polyvinylidene fluoride powder; cerium oxide powder, silicon carbide powder, A small amount of an abrasive such as strontium titanate powder; a fluidity-imparting agent such as titanium oxide powder or aluminum oxide powder; an anti-caking agent; or organic fine particles and inorganic fine particles having opposite polarity can be used in small amounts. It is also possible to use the surface of these additives after hydrophobizing them.

Next, a method for measuring each physical property related to the toner of the present invention will be described.
(1) Release agent, melting point of crystalline polyester (Tm1 and Tm2), and glass transition temperature (Tg) of toner
The measurement of the peak top of the endothermic peak of the release agent and the crystalline polyester is performed according to ASTM D 3417-99. Further, the glass transition temperature (Tg) of the toner is measured according to ASTM D 3418-99. For these measurements, for example, DSC-7 manufactured by PerkinElmer, DSC2920 manufactured by TA Instruments, and Q1000 manufactured by TA Instruments can be used. The temperature correction of the device detection unit uses the melting points of indium and zinc, and the correction of heat uses the heat of fusion of indium. An aluminum pan is used as a measurement sample, and an empty pan is set for control and measured.

Since crystalline polyester is easily compatible with the binder resin when heated, the toner of the present invention is measured using the modulated mode under the following conditions, and the toner is obtained from the DSC curve at the first temperature rise. The glass transition temperature (Tg) and the melting point of the release agent and crystalline polyester are determined.
<Measurement conditions>
・ Equilibration at 20 ° C. for 1 minute ・ Modulation of 1.5 ° C./min is applied and the temperature is raised to 180 ° C. at 2 ° C./min ・ Equilibration is maintained at 180 ° C. for 5 minutes ・ Modulation at 1.5 ° C./min And then drop to 20 ° C at 2 ° C / min

(2) Toner Outflow Start Temperature In the present invention, the toner outflow start temperature (Tfb) is measured using a flow tester CFT-500D (manufactured by Shimadzu Corporation). About 1.5 g of a 60 mesh pass product is weighed, and this is pressurized using a molding machine with a load of 10 MPa for 1 minute to obtain a measurement sample. Apply a load of 10 kgf to this sample, measure the plunger drop amount of the flow tester by the temperature rising method at a temperature rising rate of 4.0 ° C./min, a die diameter of 1.0 mm, and a die length of 1.0 mm, and start the outflow The temperature (Tfb) is obtained.

(3) Average particle size and particle size distribution of toner The weight average particle size and particle size distribution of the toner of the present invention can be measured by various methods using a Coulter Counter TA-II type or Coulter Multisizer (manufactured by Coulter). It is. In the present invention, a Coulter Multisizer (manufactured by Coulter Inc.) is used, and an interface (manufactured by Nikkiki) and a PC9801 personal computer (manufactured by NEC) for outputting the number distribution and volume distribution are connected thereto. As the electrolytic solution, a 1% NaCl aqueous solution prepared using primary sodium chloride is used. As such an electrolytic solution, for example, ISOTON R-II (manufactured by Coulter Scientific Japan) can be used.

  The measurement procedure is as follows. 0.1 to 5 ml of a surfactant, preferably alkylbenzene sulfonate, is added as a dispersant to 100 to 150 ml of the electrolyte solution, and 2 to 20 mg of a measurement sample is further added. The electrolyte solution in which the sample is suspended is subjected to a dispersion treatment with an ultrasonic disperser for about 1 to 3 minutes, and the number distribution of toner particles of 2 μm or more is measured using the 100 μm aperture as the aperture by the Coulter Multisizer. calculate. Based on this, the weight average particle diameter is determined.

ここで、「粒子投影面積」とは二値化されたトナー粒子像の面積であり、「粒子投影像の周囲長」とは該トナー粒子像のエッジ点を結んで得られる輪郭線の長さと定義する。測定は、５１２×５１２の画像処理解像度（０．３μｍ×０．３μｍの画素）で画像処理した時の粒子像の周囲長を用いる。 (4) Average circularity and mode circularity of the toner The average circularity and the mode circularity of the toner are measured using a flow type particle image measuring device “FPIA-2100 type” (manufactured by Sysmex Corporation). Use to calculate.

Here, the “particle projected area” is the area of the binarized toner particle image, and the “peripheral length of the particle projected image” is the length of the contour line obtained by connecting the edge points of the toner particle image. Define. The measurement uses the perimeter of the particle image when image processing is performed at an image processing resolution of 512 × 512 (pixels of 0.3 μm × 0.3 μm).

また、モード円形度は円形度頻度分布において、もっとも頻度が高い円形度の値である。 In the present invention, the circularity is an index indicating the degree of unevenness of the toner particles, and is 1.000 when the toner particles are completely spherical. The more complicated the surface shape, the smaller the circularity. The average circularity C, which means the average value of the circularity frequency distribution, is calculated from the following equation, where ci is the circularity (center value) at the dividing point i of the particle size distribution and m is the number of measured particles.

The mode circularity is a circularity value having the highest frequency in the circularity frequency distribution.

  In addition, in “FPIA-2100” which is a measuring apparatus used in the present invention, after calculating the circularity of each particle, the circularity of the particles is calculated based on the obtained circularity in calculating the average circularity and the circularity standard deviation. The degree of 0.4 to 1.0 is divided into classes equally divided every 0.01, and the average circularity and circularity standard deviation are calculated using the center value of the division points and the number of measured particles.

  The measurement procedure is as follows. A dispersion liquid is prepared by dispersing about 5 mg of toner in 10 ml of water in which about 0.1 mg of a surfactant is dissolved, and ultrasonic waves (20 kHz, 50 W) are irradiated on the dispersion liquid for 5 minutes. Measurement is performed with the above apparatus at 20,000 particles / μl, and the average circularity of a particle group having a circle equivalent diameter of 3 μm or more is obtained.

  In this measurement, the reason for measuring the circularity only for the particle group having an equivalent circle diameter of 3 μm or more is as follows. The group of particles having an equivalent circle diameter of less than 3 μm includes a group of external additives that exist independently from the toner particles. The influence of these external additives is eliminated, and the toner particles are more accurately circular. This is to obtain the degree. In order to suppress variation in circularity, the installation environment of the apparatus is controlled at 23 ° C. ± 0.5 ° C. so that the temperature inside the flow type particle image analyzer FPIA-2100 is 26 to 27 ° C. In addition, the autofocusing is preferably performed using 2 μm latex particles every two hours.

  Furthermore, “FPIA-2100”, which is a measuring apparatus used in the present invention, improves the magnification of the processed particle image as compared with “FPIA-1000” conventionally used for calculating the shape of the toner. Furthermore, the accuracy of toner shape measurement has been improved by improving the processing resolution of the captured image (256 × 256 → 512 × 512), thereby achieving more reliable capture of fine particles. Therefore, when it is necessary to measure the shape more accurately as in the present invention, the FPIA-2100 that can obtain information on the shape more accurately is more useful.

(5) Measurement of molecular weight of THF soluble part of toner The molecular weight of the resin component soluble in THF of the toner by GPC is measured as follows. A solution obtained by allowing the toner to stand still in THF at room temperature for 24 hours is filtered through a solvent-resistant membrane filter having a pore diameter of 0.2 μm to obtain a sample solution, and measurement is performed under the following conditions. In preparing the sample solution, the amount of THF is adjusted so that the concentration of the component soluble in THF is 0.4 to 0.6% by mass.
Apparatus: High-speed GPC HLC8120 GPC (manufactured by Tosoh Corporation)
Column: Seven series of Shodex KF-801, 802, 803, 804, 805, 806, 807 (manufactured by Showa Denko KK)
Eluent: THF
Flow rate: 1.0 ml / min
Oven temperature: 40.0 ° C
Sample injection amount: 0.10 ml

  In calculating the molecular weight of the sample, standard polystyrene resin (TSO standard polystyrene F-850, F-450, F-288, F-128, F-80, F-40, F-20, F- manufactured by Tosoh Corporation) was used. 10, F-4, F-2, F-1, A-5000, A-2500, A-1000, A-500).

(6) Molecular weight of crystalline polyester After 0.03 g of crystalline polyester was dispersed and dissolved in 10 ml of o-dichlorobenzene, it was shaken with a shaker at 135 ° C. for 24 hours, filtered through a 0.2 μm filter, and the filtrate. Is used as a sample and analyzed under the following conditions.
[Analysis conditions]
Separation column: Shodex (TSK GMHHR-H HT20) × 2
Column temperature: 135 ° C
Mobile phase solvent: o-dichlorobenzene mobile phase flow rate: 1.0 ml / min.
Sample concentration: about 0.3%
Injection volume: 300 μl
Detector: Differential refractive index detector Shodex RI-71
In calculating the molecular weight of the sample, standard polystyrene resin (TSO standard polystyrene F-850, F-450, F-288, F-128, F-80, F-40, F-20, F- manufactured by Tosoh Corporation) was used. 10, F-4, F-2, F-1, A-5000, A-2500, A-1000, A-500).

(7) Method for Measuring Acid Value of Resin The acid value of the resin is measured according to JIS K1557-1970. A specific measurement method is shown below. About 2 g of the pulverized sample is precisely weighed (W (g)). A sample is put into a 200 ml Erlenmeyer flask, 100 ml of a mixed solution of toluene / ethanol (2: 1) is added and dissolved for 5 hours. Add phenolphthalein solution as indicator. 0.1N KOH is also titrated with a burette using an alcohol solution. The amount of the KOH solution at this time is S (ml). A blank test is performed, and the amount of the KOH solution at this time is defined as B (ml).
The acid value is calculated by the following formula.
Acid value = [(SB) × f × 5.61] / W
(F: Factor of KOH solution)

(8) Method for measuring hydroxyl value of resin A sample is precisely weighed in a 100 ml eggplant flask, and 5 ml of an acetylating reagent is correctly added thereto. Then, it is immersed in a bath at 100 ° C. ± 5 ° C. and heated. After 1-2 hours, the flask is removed from the bath and allowed to cool, and then water is added and shaken to decompose acetic anhydride. Furthermore, in order to complete the decomposition, the flask is again heated in a bath for 10 minutes or more and allowed to cool, and then the wall of the flask is thoroughly washed with an organic solvent. This solution is subjected to potentiometric titration with an N / 2 potassium hydroxide ethyl alcohol solution using a glass electrode to obtain a hydroxyl value (according to JIS K0070-1966).

Next, an example of an image forming apparatus that can suitably use the toner of the present invention will be specifically described with reference to FIG. In FIG. 1, reference numeral 100 denotes a photosensitive drum, which is provided with a primary charging roller 117, a developing device 140 having a developing sleeve 102, a transfer charging roller 114, a cleaner 116, a register roller 124, and the like. The photosensitive drum 100 is charged to, for example, −600 V by the primary charging roller 117 (applied voltages are, for example, an AC voltage of 1.85 kVpp and a DC voltage of −620 Vdc). Then, exposure is performed by irradiating the photoreceptor 100 with the laser beam 123 by the laser generator 121, and an electrostatic latent image corresponding to the target image is formed. The electrostatic latent image on the photosensitive drum 100 is developed with a one-component magnetic toner by the developing device 140 to become a toner image, and the toner image is transferred onto the transfer material by the transfer roller 114 that is in contact with the photoconductor via the transfer material. Transcribed. The transfer material on which the toner image is placed is conveyed to the fixing device 126 by the conveying belt 125 or the like and fixed on the transfer material. Further, the toner remaining on the photoconductor after the transfer is cleaned by the cleaner 116.
Although the magnetic one-component jumping development type image forming apparatus is shown here, the toner of the present invention may be a magnetic toner or a non-magnetic toner, and may be a one-component development method or a two-component development development method. Any toner may be used. The toner of the present invention can be applied to either a jumping development system or a contact development system.

  Hereinafter, the present invention will be described more specifically with reference to production examples and examples, but these do not limit the present invention in any way. “Parts” described below indicates “parts by mass” unless otherwise specified.

<Production example of magnetic powder>
In the ferrous sulfate aqueous solution, l. Add 0 to 1.1 equivalents of caustic soda solution, 0.4 mass% sodium hexametaphosphate in terms of phosphorus element, and 1.0 mass% sodium silicate in terms of silicon element, and mix to contain ferrous hydroxide An aqueous solution was prepared. While maintaining the pH of this aqueous solution at 8 using sulfuric acid and caustic soda solution, air was blown in and an oxidation reaction was performed at 85 ° C. to prepare a slurry liquid having seed crystals.

  Next, after adding ferrous sulfate aqueous solution so that it becomes 0.9 to 1.2 equivalent to the existing alkali amount (sodium component of caustic soda) to this slurry liquid, the pH of the slurry liquid is adjusted to sulfuric acid and caustic soda solution. The slurry was maintained at 7.6 and the oxidation reaction was advanced while blowing air to obtain a slurry liquid containing magnetic iron oxide. After the slurry liquid was filtered and washed, a hydrous slurry liquid was generated. At this time, a small sample of the water-containing slurry was collected and the water content was measured. Next, this water-containing slurry is put into another aqueous medium without being dried, and sufficiently redispersed with a pin mill while stirring and circulating the slurry, and the pH of the redispersed liquid is adjusted to about 4.8. Add 1.5 parts of n-hexyltrimethoxysilane coupling agent to the magnetic iron oxide with sufficient stirring (the amount of magnetic iron oxide was calculated as the water content minus the water content) to hydrolyze went. Thereafter, the mixture was sufficiently stirred and dispersed with a pin mill while circulating the slurry, the pH of the dispersion was adjusted to 8.9, a condensation reaction was performed, and a coupling treatment was performed. The produced hydrophobic magnetic powder is filtered through a drum filter and thoroughly washed, and then dried at 120 ° C. for 1 hour and at 100 ° C. for 60 minutes. 22 μm of magnetic powder 1 was obtained.

<Production Example of Crystalline Polyester 1>
In a reaction apparatus equipped with a stirrer, a thermometer, and an outflow cooler, 230.3 parts (1.0 mol part) of 1,10-decanedicarboxylic acid, 108.2 parts (1.02 mol part) of diethylene glycol, tetrabutyl titanate 50 parts were added and esterification was performed at 190 ° C. for 5 hours. Thereafter, the temperature was raised to 220 ° C., the pressure inside the system was gradually reduced, and a polycondensation reaction was performed at 150 Pa for 2 hours. After the reaction system was cooled to room temperature, 30.5 parts by mass (0.25 mol part) of benzoic acid was added, and further reacted at 220 ° C. for 3 hours to obtain polyester 1. The physical properties of the obtained polyester 1 are shown in Table 1.

<Production Example of Crystalline Polyester 2>
In the production of the crystalline polyester 1, the reaction was carried out by changing the addition amount of tetrabutyl titanate to 0.68 parts and setting the polycondensation reaction time to 1 hour. After cooling the reaction system to room temperature, 72.2 parts (0.59 mole part) of benzoic acid was added, and further reacted at 220 ° C. for 3 hours to obtain polyester 2. The physical properties of the obtained polyester 2 are shown in Table 1.

<Production Example of Crystalline Polyester 3>
In the production of the crystalline polyester 1, the reaction was carried out by changing the addition amount of tetrabutyl titanate to 0.42 parts and setting the polycondensation reaction time to 3 hours. After the reaction system was cooled back to room temperature, 22.2 parts (0.18 mole part) of benzoic acid was added and reacted at 220 ° C. for 3 hours to obtain polyester 3. Table 1 shows the physical properties of Polyester 3 obtained.

<Production Example of Crystalline Polyester 4>
In the production of the crystalline polyester 1, the reaction was carried out by changing the addition amount of tetrabutyl titanate to 0.33 parts and setting the polycondensation reaction time to 4 hours. After cooling the reaction system to room temperature, 13.3 parts (0.11 mole part) of benzoic acid was added, and the mixture was further reacted at 220 ° C. for 3 hours to obtain polyester 4. The physical properties of the obtained polyester 4 are shown in Table 1.

<Production Example of Crystalline Polyester 5>
A reactor equipped with a stirrer, a thermometer, and an outflow cooler is charged with 146.1 parts (1.0 mole part) of adipic acid, 108.2 parts (1.02 mole part) of diethylene glycol, and 0.50 parts by weight of tetrabutyl titanate. The polycondensation reaction was carried out in the same manner as in the production of crystalline polyester 1. After cooling the reaction system to room temperature, 30.5 parts by mass (0.25 mol part) of benzoic acid was added, and further reacted at 220 ° C. for 3 hours to obtain polyester 5. Table 1 shows the physical properties of Polyester 5 obtained.

<Production Example of Crystalline Polyester 6>
A reactor equipped with a stirrer, a thermometer, and an outlet cooler is charged with 118.1 parts (1.0 mole part) of succinic acid, 63.3 parts (1.02 mole part) of ethylene glycol, and 0.50 part of tetrabutyl titanate. The polycondensation reaction was carried out in the same manner as in the production of crystalline polyester 1. After returning to normal temperature, 30.5 parts (0.25 mole part) of benzoic acid was added and reacted at 220 ° C. for 3 hours to obtain polyester 6. The physical properties of the obtained polyester 6 are shown in Table 1.

<Production Example of Crystalline Polyester 7>
In a reaction apparatus equipped with a stirrer, a thermometer, and an outflow cooler, 230.3 parts (1.0 mol part) of 1,10-decanedicarboxylic acid, 108.2 parts (1.02 mol part) of diethylene glycol, tetrabutyl titanate 50 parts were added and esterification was performed at 190 ° C. for 5 hours. Thereafter, the temperature of the reaction system was raised to 220 ° C., the pressure inside the system was gradually reduced, and a polycondensation reaction was performed at 150 Pa for 2 hours. After the reaction system was once cooled to room temperature, 30.5 parts (0.25 mol part) of benzoic acid and 2.7 parts (0.013 mol part) of trimellitic acid were added, and further reacted at 220 ° C. for 3 hours to obtain polyester 7. Table 1 shows the physical properties of Polyester 7 obtained.

<Production example of crystalline polyester 8>
In a reaction apparatus equipped with a stirrer, a thermometer, and an outflow cooler, 230.3 parts (1.0 mol part) of 1,10-decanedicarboxylic acid, 108.2 parts (1.02 mol part) of diethylene glycol, tetrabutyl titanate 50 parts were added and esterification was performed at 190 ° C. for 5 hours. Thereafter, the temperature of the reaction system was raised to 220 ° C., the pressure inside the system was gradually reduced, and a polycondensation reaction was performed at 150 Pa for 2 hours. After cooling the reaction system to room temperature, 30.5 parts (0.25 mol part) of benzoic acid and 4.4 parts (0.021 mol part) of trimellitic acid were added, and further reacted at 220 ° C. for 3 hours to obtain polyester 8. The physical properties of the obtained polyester 8 are shown in Table 1.

<Production example of crystalline polyester 9>
In a reaction apparatus equipped with a stirrer, a thermometer, and an outflow cooler, 230.3 parts (1.0 mol part) of 1,10-decanedicarboxylic acid, 108.2 parts (1.02 mol part) of diethylene glycol, tetrabutyl titanate 50 parts were added and esterification was performed at 190 ° C. for 5 hours. Thereafter, the temperature of the reaction system was raised to 220 ° C., the pressure inside the system was gradually reduced, and a polycondensation reaction was performed at 150 Pa for 2 hours. After cooling the reaction system to room temperature, 24.4 parts by mass (0.20 mol part) of benzoic acid was added, and the mixture was further reacted at 220 ° C. for 3 hours to obtain polyester 9. The physical properties of the obtained polyester 9 are shown in Table 1.

<Production Example of Magnetic Toner 1>
After adding 450 parts of 0.1 M Na ₃ PO ₄ aqueous solution to 720 parts of ion-exchanged water and heating to 60 ° C., 67.7 parts of 1.0 M CaCl ₂ aqueous solution is added to contain a dispersion stabilizer. An aqueous medium was obtained.
-Styrene 78.0 parts-N-butyl acrylate 22.0 parts-Divinylbenzene 0.53 parts-Crystalline polyester 1 10.0 parts-Monoazo dye iron complex (T-77: manufactured by Hodogaya Chemical Co., Ltd.) 1.0 Parts / magnetic powder 1 90.0 parts / saturated polyester resin 10.0 parts (saturated polyester resin obtained by condensation reaction of EO (ethylene oxide) adduct of bisphenol A and terephthalic acid: number average molecular weight (Mn) = 5000; acid value = 12 mgKOH / g; Tg = 68 ° C)

  The above formulation was uniformly dispersed and mixed using an attritor (Mitsui Miike Chemical Co., Ltd.) to obtain a monomer composition. The monomer composition was heated to 60 ° C., 10 parts of paraffin wax (melting point: 78 ° C.) was added, mixed and dissolved therein, and then the polymerization initiator 2,2′-azobis (2,4-dimethyl). Valeronitrile) 4.5 parts was dissolved.

The monomer composition was charged into the aqueous medium, and granulated by stirring at 12000 rpm for 10 minutes with a TK homomixer (Special Machine Industries Co., Ltd.) in an N ₂ atmosphere at 60 ° C. Thereafter, the reaction was carried out at 70 ° C. for 5 hours while stirring with a paddle stirring blade, and then the temperature was raised to 90 ° C. and the mixture was stirred for 2 hours. After completion of the reaction, the suspension was slowly cooled to 40 ° C. at 5 ° C./10 min, acid-washed with hydrochloric acid, filtered, washed with water, and dried to obtain toner particles 1.

On the other hand, silica having a number average primary particle size of 12 nm was treated with hexamethyldisilazane and then with silicone oil to obtain a hydrophobic silica fine powder having a BET value of 120 m ² / g after treatment. 1.0 part of this hydrophobic silica fine powder and 100 parts of the toner particles 1 were mixed with a Henschel mixer (Mitsui Miike Chemical Co., Ltd.) to obtain a magnetic toner 1 having a weight average particle diameter of 7.5 μm. . Table 2 shows the physical properties of the magnetic toner 1.

<Production Example of Magnetic Toner 2>
A magnetic toner 2 was obtained in the same manner as in the above production example except that ester wax (stearyl stearate; melting point: 63 ° C.) was used instead of paraffin wax in the production example of magnetic toner 1. Table 2 shows the physical properties of the magnetic toner 2.

<Production Example of Magnetic Toner 3>
A magnetic toner 3 was obtained in the same manner as in the above production example except that the crystalline polyester 2 was used in place of the crystalline polyester 1 in the production example of the magnetic toner 1. Table 2 shows the physical properties of the magnetic toner 3.

<Production Example of Magnetic Toner 4>
A magnetic toner 4 was obtained in the same manner as in the above production example except that the crystalline polyester 3 was used instead of the crystalline polyester 1 in the production example of the magnetic toner 1. Table 2 shows the physical properties of the magnetic toner 4.

<Production Example of Magnetic Toner 5>
A magnetic toner 5 was obtained in the same manner as in the above production example except that the crystalline polyester 4 was used in place of the crystalline polyester 1 in the production example of the magnetic toner 1. Table 2 shows the physical properties of the magnetic toner 5.

<Production Example of Magnetic Toner 6>
A magnetic toner 6 was obtained in the same manner as in the above production example except that the crystalline polyester 5 was used instead of the crystalline polyester 1 in the production example of the magnetic toner 2. Table 2 shows the physical properties of the magnetic toner 6.

<Production Example of Magnetic Toner 7>
In the production example of the magnetic toner 1, the magnetic toner was used in the same manner as in the above production example except that the crystalline polyester 6 was used instead of the crystalline polyester 1, the reaction was performed for 5 hours after granulation, and the temperature was raised to 98 ° C. 7 was obtained. Table 2 shows the physical properties of the magnetic toner 7.

<Production Example of Magnetic Toner 8>
A magnetic toner 8 was obtained in the same manner as in the above production example except that the crystalline polyester 7 was used instead of the crystalline polyester 1 in the production example of the magnetic toner 1. Table 2 shows the physical properties of the magnetic toner 8.

<Production example of magnetic toner 9>
Magnetic toner 9 was obtained in the same manner as in the above production example, except that in the production example of magnetic toner 1, crystalline polyester 8 was used instead of crystalline polyester 1. Table 2 shows the physical properties of the magnetic toner 9.

<Production example of magnetic toner 10>
A magnetic toner 10 was obtained in the same manner as in the above production example except that the crystalline polyester 9 was used in place of the crystalline polyester 1 in the production example of the magnetic toner 1. Table 2 shows the physical properties of the magnetic toner 10.

<Production example of magnetic toner 11>
In the magnetic toner 1 production example, after stirring at 90 ° C. for 2 hours, the suspension was quenched at 20 ° C./min, washed with acid, filtered / washed with water, and dried. Magnetic toner 11 was obtained. Table 2 shows the physical properties of the magnetic toner 11.

<Production example of magnetic toner 12>
In the production example of magnetic toner 1, magnetic toner 12 was obtained in the same manner as in the above production example except that the amount of crystalline polyester was changed from 10 parts by mass to 2 parts by mass. Table 2 shows the physical properties of the magnetic toner 12.

<Production example of magnetic toner 13>
In the production example of the magnetic toner 1, the magnetic toner 13 was obtained in the same manner as in the above production example except that the amount of the crystalline polyester was changed from 10 parts by mass to 31 parts by mass. Table 2 shows the physical properties of the magnetic toner 13.

<Production example of magnetic toner 14>
A magnetic toner 14 was obtained in the same manner as in the above production example except that the amount of paraffin wax in the production example of the magnetic toner 1 was changed from 10 parts by mass to 1 part by mass. Table 2 shows the physical properties of the magnetic toner 14.

<Production example of magnetic toner 15>
In the production example of magnetic toner 1, magnetic toner 15 was obtained in the same manner as in the above production example except that the amount of paraffin wax was changed from 10 parts by mass to 31 parts by mass. Table 2 shows the physical properties of the magnetic toner 15.

<Production example of magnetic toner 16>
Magnetic toner 16 was obtained in the same manner as in the above production example, except that in the production example of magnetic toner 1, paraffin wax (melting point: 78 ° C.) was replaced with microcrystalline wax (melting point: 85 ° C.). Table 2 shows the physical properties of the magnetic toner 16.

<Production example of magnetic toner 17>
Magnetic toner 17 was obtained in the same manner as in the above production example except that in the production example of magnetic toner 1, paraffin wax (melting point: 78 ° C.) was replaced with polyethylene wax (melting point: 95 ° C.). Table 2 shows the physical properties of the magnetic toner 17.

<Production example of magnetic toner 18>
Magnetic toner 18 was obtained in the same manner as in the above production example, except that in the production example of magnetic toner 1, the amount of divinylbenzene was changed from 0.53 parts to 0.10 parts. Table 2 shows the physical properties of the magnetic toner 18.

<Production example of magnetic toner 19>
A magnetic toner 19 was obtained in the same manner as in the above production example, except that in the production example of the magnetic toner 1, the amount of divinylbenzene was changed from 0.53 parts to 1.20 parts. Table 2 shows the physical properties of the magnetic toner 19.

<Production example of magnetic toner 20>
A magnetic toner 20 was obtained in the same manner as in the above production example except that the crystalline polyester 1 was not used in the production example of the magnetic toner 1. Table 2 shows the physical properties of the magnetic toner 20.

<Production example of magnetic toner 21>
A magnetic toner 21 was obtained in the same manner as in the above production example except that no paraffin wax was used in the production example of the magnetic toner 1. Table 2 shows the physical properties of the magnetic toner 21.

<Example 1>
(Image forming device)
As an image forming apparatus, a modified LBP3000 (manufactured by Canon) was used. Here, a process speed was set to 110 mm / sec, and a developing bias in which an alternating electric field of 1.5 kVpp and a frequency of 2200 Hz was superimposed on a DC voltage Vdc of −430 V was used. Under these conditions, the magnetic toner 1 is used, and the printing rate is set using 8 points of A characters in a normal temperature and humidity environment (23 ° C., 60% RH) and a high temperature and high humidity environment (32.5 ° C., 80% RH). An image endurance test of 2500 sheets was performed in intermittent mode with an image of 4%. As the recording medium, A4 75 g / m ² paper was used. As a result, there was no fog on the non-image area at the beginning and after the endurance test, the image density was 1.4 or more, and a high-definition image without scattering was obtained.

Further, a halftone image was formed using FOX RIVER BOND paper so that the image density was 0.6 to 0.65, and the image was fixed by changing the temperature of the fixing device. Thereafter, the fixed image was rubbed 10 times with a Silbon paper applied with a weight of 50 g / cm ² , and the temperature at which the density reduction rate of the fixed image after the rub was 10% was defined as the fixing start temperature. In addition, a solid image was formed on A4 75 g / m ² paper so that the toner mass per unit area was 0.6 mg / cm ^2, and the temperature at which the fixing device was offset by variously changing the temperature of the fixing device was examined. . Whether or not high temperature offset was performed was determined by visually observing the image on the paper, and the highest temperature (fixing end temperature) at which high temperature offset was not found was obtained. As a result, the fixing start temperature of the magnetic toner 1 was 165 ° C., and the fixing end temperature was 230 ° C.

Furthermore, 5000 sheets of continuous durability were performed using a 10 mm × 10 mm grid chart in a normal temperature and humidity environment, and the fouling of the pressure roller of the fixing device was evaluated. As the transfer medium, 75 g / m ² paper having a calcium carbonate content of 30% was used. The evaluation results are shown in Table 3.

  The evaluation methods for each evaluation performed in the examples and comparative examples of the present invention and the judgment criteria thereof will be described below.

<Image density>
The image density formed a solid image portion, and the density of the solid image was measured with a Macbeth reflection densitometer (manufactured by Macbeth).

<Fog>
A white image was output, and the reflectance was measured using a REFECTMETER MODEL TC-6DS manufactured by Tokyo Denshoku. On the other hand, the reflectance of the transfer paper (standard paper) before white image formation was measured in the same manner. As filters, a green filter was used for black and magenta toners, an amber filter was used for cyan toners, and a blue filter was used for yellow toners. The fog was calculated from the reflectance before and after the white image output using the following formula.
Fog (reflectance) (%)
= Reflectance of standard paper (%)-reflectance of white image sample (%)
The evaluation criteria for fogging are as follows.
A: Very good (less than 1.5%)
B: Good (1.5% or more and less than 2.5%)
C: Normal (2.5% or more and less than 4.0%)
D: Poor (4% or more)

<Toner fusion>
After the endurance test, it was judged by visual observation whether or not toner fusion occurred on the toner carrier, and evaluation was performed according to the following criteria.
A: Fusion has not occurred.
B: Slight fusion occurred but good level.
C: Although fusion has occurred, it is a level that does not appear in the image and there is no practical problem.
D: Fusing has occurred and is not preferable for practical use at a level where streaks are generated on the image.

<Pressure roller dirt>
The pressure roller dirt was evaluated according to the following criteria.
A: Pressure roller dirt is not generated B: Pressure roller is dirty, but there is no problem in practical use C: Pressure roller dirt is noticeably generated and practically unfavorable level

<Examples 2 to 16>
The image endurance test and the fixing test were performed in the same manner as in Example 1 except that the magnetic toners 2 to 8 and 12 to 19 were used. As a result, each of the toners showed an image of a level that was practically satisfactory at the beginning and after the endurance test, and showed good fixability. The evaluation results are shown in Tables 3 and 4.

<Comparative Examples 1-5>
An image forming test and a fixing test were conducted in the same manner as in Example 1 except that the magnetic toners 9 to 11, 20, and 21 were used. As a result, in the case of the magnetic toners 9 and 10, the density was lowered in a high temperature and high humidity environment, and the pressure roller was significantly stained. In the case of the magnetic toner 11, although the low-temperature fixability is good, the toner fusing occurred during the durability in the high-temperature and high-humidity environment. In the case of the magnetic toners 20 and 21, a good image was obtained through durability, but the low-temperature fixability was poor. The evaluation results are shown in Tables 3 and 4.

<Production example of magnetic toner 22>
After the crystalline polyester 1 was sufficiently cooled with liquid nitrogen, the crystalline polyester was finely pulverized to a particle size of 1 μm or less with a scramjet mill (manufactured by Deoksugaku Kosakusho).
Styrene / n-butyl acrylate copolymer (mass ratio 78/22) 79.0 parts Finely pulverized crystalline polyester 1 10.0 parts Paraffin wax 10.0 parts Monoazo dye iron complex (manufactured by T-77 Hodogaya Chemical Co., Ltd.) 1.0 part Magnetic powder 1 90.0 parts Saturated polyester used in Toner Production Example 1 10.0 parts

  Next, the above materials are mixed in a blender, melt kneaded with a biaxial extruder heated to 100 ° C., the cooled kneaded product is coarsely pulverized with a hammer mill, and the coarsely pulverized product is finely pulverized with a jet mill. The pulverized product was subjected to air classification to obtain magnetic toner particles 22. Thereafter, the magnetic toner particles 22 were processed twice at 6000 rpm for 3 minutes using a hybridizer (manufactured by Nara Machinery Co., Ltd.) to obtain magnetic toner particles 22 ′. 100 parts of the magnetic toner particles 22 ′ and 1.0 part by mass of silica used in the production example of the magnetic toner 1 are mixed with a Henschel mixer (Mitsui Miike Chemical Co., Ltd.), and the number average particle diameter is 7.4 μm. Toner 22 was prepared. Table 5 shows the physical properties of the magnetic toner 22.

<Production example of magnetic toner 23>
In the production example of the magnetic toner 22, the magnetic toner is produced in the same manner as in the production example of the magnetic toner 22 except that the crystalline polyester 1 is not cooled with liquid nitrogen but is finely pulverized by a scramjet mill (manufactured by Tokuju Factory). Got 23. Table 5 shows the physical properties of the magnetic toner 23.

<Production example of magnetic toner 24>
In the production example of the magnetic toner 22, a magnetic toner 24 was obtained in the same manner as in the production example of the magnetic toner 22 except that the crystalline polyester 1 was used without being pulverized. Table 5 shows the physical properties of the magnetic toner 24.

<Production example of magnetic toner 25>
In the production of the magnetic toner 22, the magnetic toner 25 was obtained in the same manner as in the production example of the magnetic toner 22 except that the temperature of the biaxial extruder was changed to 150 ° C. Table 5 shows the physical properties of the magnetic toner 25.

<Manufacture of magnetic toner 26>
(Preparation of resin fine particle dispersion)
Styrene 303 parts
n Butyl acrylate 105 parts Divinylbenzene 2 parts Dodecanethiol 6 parts Carbon tetrabromide 4 parts The above ingredients were mixed and dissolved to prepare a solution.
Further, 6 parts of a nonionic surfactant and 10 parts of an anionic surfactant were dissolved in 550 parts of ion-exchanged water in a flask, and the above solution was added and dispersed and emulsified in the flask. To the obtained emulsion, 50 parts by mass of ion-exchanged water in which 5 parts by mass of ammonium persulfate was dissolved was added while slowly stirring and mixing for 10 minutes. Next, after sufficiently replacing the system with nitrogen, the mixture was heated to 70 ° C. in an oil bath with stirring, and emulsion polymerization was continued for 5 hours to disperse the anionic resin fine particles containing resin fine particles having an average particle size of 160 nm. A liquid was obtained.

(Preparation of magnetic dispersion)
Magnetic powder 1 150 parts Nonionic surfactant 10 parts Ion-exchanged water 400 parts The above components were mixed and dissolved, and dispersed with a homogenizer for 10 minutes to obtain a magnetic dispersion.

(Preparation of release agent dispersion)
Paraffin wax (melting point peak temperature 78 ° C) 50 parts Cationic surfactant 5.5 parts Ion exchange water 200 parts The above components are subjected to dispersion treatment with a pressure discharge type homogenizer and contain release agent particles having a center diameter of 0.16 µm An agent dispersion was obtained.

(Preparation of crystalline polyester dispersion)
Crystalline polyester 1 50 parts Cationic surfactant 5.5 parts Ion-exchanged water 200 parts The above components are subjected to a dispersion treatment with a pressure discharge type homogenizer to obtain a crystalline polyester dispersion containing crystalline polyester particles having a center diameter of 0.35 μm. It was.

(Manufacture of toner)
Resin fine particle dispersion 200 parts Magnetic substance dispersion 283 parts Release agent dispersion 64 parts Crystalline polyester dispersion 64 parts Polyaluminum chloride 1.23 parts Thoroughly mix and disperse the above ingredients with a homogenizer, then add to flask and heat The mixture was heated to an aggregation temperature of 58 ° C. while stirring in an oil bath. Thereafter, after maintaining at 58 ° C. for 60 minutes, 30 parts of the resin fine particle dispersion 1 was further added and gently stirred.

  Thereafter, the pH of the system was adjusted to 7.0 with a 0.5 mol / L sodium hydroxide aqueous solution, and then the flask was sealed and heated to 90 ° C. while continuing stirring. Thereafter, the pH was lowered to 4.0 and held for 5 hours. After completion of the reaction, the mixture was gradually cooled to room temperature at 5 ° C. for 10 min, filtered, sufficiently washed with ion exchange water, filtered, washed and dried to obtain magnetic particles 26. 100 parts by mass of the obtained magnetic particles 26 and 1.0 part of silica used in the production of the magnetic toner 1 were mixed with a Henschel mixer (Mitsui Miike Chemical Co., Ltd.), and the number average particle diameter was 7.3 μm. Toner 26 was obtained. Table 5 shows the physical properties of the magnetic toner 26.

<Manufacture of magnetic toner 27>
After adding 450 parts of 0.1 M Na ₃ PO ₄ aqueous solution to 720 parts of ion-exchanged water and heating to 60 ° C., 67.7 parts of 1.0 M CaCl ₂ aqueous solution is added to contain a dispersion stabilizer. An aqueous medium was obtained.

Styrene / n-butyl acrylate copolymer (mass ratio 78/22)
79.0 parts Crystalline polyester 1 10.0 parts Paraffin wax 10.0 parts Iron complex of monoazo dye (manufactured by T-77 Hodogaya Chemical Co., Ltd.) 1.0 part Magnetic powder 1 90.0 parts In Toner Production Example 1 Saturated polyester used 10.0 parts Methyl ethyl ketone 80 parts Ethyl acetate 80 parts A mixture of the above components was dispersed for 3 hours using an attritor (Mitsui Metals Co., Ltd.) to prepare a dispersion.

Next, the dispersion was put into the aqueous medium, and the mixture was granulated by stirring at 12000 rpm for 10 minutes in a TK homomixer (Special Machine Industries Co., Ltd.) in an N ₂ atmosphere at 60 ° C. Thereafter, the propeller stirrer was changed, the rotation speed of the stirrer was maintained at 150 rpm, the internal temperature was raised to 95 ° C. and held for 3 hours to adjust the toner particle dispersion. Next, this toner particle dispersion was slowly cooled to room temperature at 5 ° C./10 min, acid washed with hydrochloric acid, filtered, washed with water, and dried to obtain toner particles 27.
100 parts by mass of the toner particles 27 and 1.0 part by mass of the hydrophobic silica fine powder used in the production of the magnetic toner 1 were mixed with a Henschel mixer (Mitsui Miike Chemical Co., Ltd.), and the weight average particle diameter was 7.2. A μm magnetic toner 27 was obtained. Table 5 shows the physical properties of the magnetic toner 27.

<Manufacture of magnetic toner 28>
In the production of the magnetic toner 27, the concentration of the Na ₃ PO ₄ aqueous solution was changed from 0.10M to 0.13M, the concentration of the CaCl ₂ aqueous solution was changed from 1.0M to 1.3M, and the saturated polyester used in Toner Production Example 1 was changed. A magnetic toner 28 was obtained in the same manner as in the production of the magnetic toner 27 except that it was not used. Table 5 shows the physical properties of the magnetic toner 28.

<Examples 17 to 21>
The image endurance test and the fixing test were performed in the same manner as in Example 1 except that the magnetic toners 22, 23, and 26 to 28 were used. As a result, in any of the toners, an image having a level that is practically satisfactory at the beginning and after the endurance test was obtained, and good fixability was exhibited. The evaluation results are shown in Tables 6 and 7.

<Comparative Examples 6 and 7>
Except that the magnetic toners 24 and 25 were used, an image output test and a fixing test were performed in the same manner as in Example 1. As a result, in the case of the magnetic toners 24 and 25, toner fusion and fogging occurred at a high level. The evaluation results are shown in Tables 6 and 7.

FIG. 3 is a schematic cross-sectional view showing an example of an image forming apparatus that can suitably use the toner of the present invention.

Explanation of symbols

100 Photosensitive drum (image carrier, charged body)
102 Developing sleeve (magnetic toner carrier)
114 Transfer charging roller (transfer member)
116 Cleaner 117 Primary charging roller (contact charging member)
121 Laser generator (latent image forming means, exposure device)
124 register roller 125 transport belt 126 fixing device 140 developing device 141 stirring member

Claims (17)

In a toner containing at least a binder resin, a crystalline polyester, and a release agent, the acid value of the crystalline polyester is 4.0 mgKOH / g or less, the hydroxyl value is 5.0 mgKOH / g or less, and a flow tester The toner outflow start temperature (Tfb) and the melting point (Tm1) of the crystalline polyester measured by the following formula (1):
Tm1 ≦ Tfb ≦ Tm1 + 12 ° C. (1)
A toner characterized by satisfying the following relationship:   The toner according to claim 1, wherein an acid value of the crystalline polyester is 2.5 mgKOH / g or less. The toner outflow start temperature (Tfb) and the crystalline polyester melting point (Tm1) measured by the flow tester are expressed by the following formula (2):
Tm1 ≦ Tfb ≦ Tm1 + 6 ° C. (2)
The toner according to claim 1, wherein the toner satisfies the relationship: The melting point (Tm2) of at least one release agent contained in the toner and the melting point (Tm1) of the crystalline polyester are represented by the following formula (3):
Tm2 ≦ Tm1 + 10 ° C. (3)
The toner according to claim 1, wherein the toner satisfies the relationship: The melting point (Tm2) of at least one release agent contained in the toner and the melting point (Tm1) of the crystalline polyester are expressed by the following formula (4):
Tm2 ≦ Tm1 (4)
The toner according to claim 1, wherein the toner satisfies the relationship:   The toner according to claim 1, wherein the release agent is contained in an amount of 2 to 30% by mass with respect to the binder resin.   The toner according to claim 1, wherein the crystalline polyester has a number average molecular weight of 2,000 to 10,000.   The toner according to claim 1, wherein the crystalline polyester has a number average molecular weight of 2000 to 6000.   The toner according to claim 1, wherein the crystalline polyester has a peak top of an endothermic peak in a range of 60 to 95 ° C. in an endothermic curve obtained by measurement with a differential scanning calorimeter (DSC). .   The toner according to claim 1, wherein the crystalline polyester is contained in an amount of 3 to 30% by mass with respect to the binder resin.   The toner according to claim 1, wherein a THF-insoluble content of the resin component of the toner is 5 to 65%.   The toner according to claim 1, wherein an average circularity of the toner is 0.960 or more.   The toner according to claim 1, wherein the toner has a mode circularity of 0.980 or more.   The toner according to claim 1, wherein the toner has a core-shell structure.   The toner according to claim 14, wherein the shell having the core-shell structure is formed of an amorphous high molecular weight material.   The toner according to claim 14, wherein the amorphous high molecular weight material forming the shell is polyester. The toner according to claim 1, wherein the toner is a toner produced in an aqueous medium.

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