JP2012037614A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming device for stably forming a high quality image by using: electrostatic charge image developing toner which is capable of achieving both of low temperature fixability and blocking resistance, has a superior fixing image strength and is excellent in production stability and stable qualities; and an electrophotographic photoreceptor containing a charge transport material having a specific structure.SOLUTION: In an electrophotographic process using electrostatic charge image developing toner and an electrophotographic photoreceptor, the toner comprises at least a binder resin, a colorant and wax and the binder resin is obtained by a first step of polymerizing a long chain (meth)acrylate ester and a second step of polymerizing a vinyl monomer in the presence of the polymer obtained in the first step, and the electrophotographic photoreceptor contains a polyester resin in the outermost surface layer.

Description

  The present invention achieves both low-temperature fixability and blocking resistance, is excellent in fixed image strength, and is further excellent in production stability, and an electrophotographic image containing a specific binder resin in the outermost layer. The present invention relates to an image forming apparatus that stably forms a high-quality image by using a photoreceptor.

  The toner for developing an electrostatic charge image is used for image formation for visualizing an electrostatic charge image in a printer, a copying machine, a facsimile, or the like. Taking an example of electrophotographic image formation, an electrostatic latent image is first formed on a photoreceptor, then developed with toner, transferred to transfer paper, and fixed by heat or the like. Formation takes place. As a toner for developing an electrostatic image at that time, usually, a binder resin and a colorant are dry-mixed with a charge control agent, a release agent, a magnetic material, etc., if necessary, and then melt-kneaded with an extruder or the like. Then, for the purpose of imparting various performances such as fluidity to the toner particles obtained by the so-called melt-kneading pulverization method, which is then pulverized and classified, solid fine particles such as silica were adhered to the surface as external additives. The form is used.

  In recent years, high-definition image quality has been required in image formation for copying machines and printers, and in order to meet this demand, the average particle size of toner particles must be about 3 to 8 μm and the particle size distribution must be narrow. In the melt-kneading pulverization method, it is difficult to control the particle size of the toner particles, and when trying to obtain toner particles having an average particle size in the range of 3 to 8 μm, a large amount of fine powder having a desired particle size or less is produced as a by-product, There was a problem that it was difficult to classify this in the classification process.

As a method for improving such problems in the melt-kneading pulverization method, a production method by a polymerization method such as a suspension polymerization method, an emulsion polymerization aggregation method, or a dissolution suspension method has been proposed instead of the melt-kneading pulverization method. .
The suspension polymerization method is a method for producing toner particles by suspending and dispersing a composition containing a polymerizable monomer, a polymerization initiator, a colorant and the like in an aqueous medium and then polymerizing the suspension. In the emulsion polymerization aggregation method, a polymerizable monomer is emulsified in an aqueous medium containing a polymerization initiator and an emulsifier, and the polymerizable monomer is polymerized with stirring to obtain polymer primary particles, which are then colored. In this method, the primary particles of the polymer are aggregated by adding an agent and, if necessary, a charge control agent, and the obtained aggregated particles are aged to produce toner particles. In the dissolution suspension method, a solution phase obtained by dissolving a binder resin in an organic solvent and adding and dispersing a colorant is dispersed in an aqueous phase containing a dispersant by a mechanical shearing force. The toner particles are produced by removing the organic solvent from the droplets.

  According to these polymerization methods, it is easy to control the particle size of the toner particles, so that it is possible to obtain toner particles that have a small particle size and a narrow particle size distribution and can form a high-definition image quality. In the emulsion polymerization aggregation method, the polymerization of the polymerizable monomer and the granulation of the toner particles are performed within the production process. There is an advantage that the required energy is small, and it is easy to adjust the toner having a small particle diameter, and it is easy to control the particle size distribution and particle diameter.

  With the recent spread of copiers and printers, in addition to demands for image quality, toners that are particularly excellent in high-speed printing and low-energy fixability have been desired, and attempts have been made to improve the low-temperature fixability of toner. It has been. Low temperature fixability, blocking resistance, and high temperature offset resistance are usually in a trade-off relationship, and it is desired to achieve both.

JP 2002-182428 A JP 2002-284866 A JP 2005-234046 A JP 2006-113473 A JP 2005-308995 A Japanese Patent Publication No. 56-13943 JP-A-7-301949 JP-A-8-95294 JP 2005-208653 A

In order to achieve both low-temperature fixability and blocking resistance, a wax is used as an anti-offset agent. However, there is a limit to the wax content in the toner, and if it is used excessively, leakage from the toner occurs and the anti-blocking property is deteriorated. For this reason, there is a limit to improving the low-temperature fixability with wax.
As a method for improving the low-temperature fixability, techniques for improving the low-temperature fixability by including a crystalline polyester resin in an amorphous resin have also been proposed (Patent Documents 1 to 5). When these crystalline polyester resins are dispersed and contained in an incompatible non-crystalline resin, for example, when the non-crystalline resin is a styrene resin, the dispersion domain of the crystalline polyester component is not dispersed sufficiently small. The resulting toner exhibits brittleness, which is a defect of crystalline resin, adhesion to a member during development, and a problem that the temperature range of fixing becomes very small due to a sudden drop in elasticity during heating. was there.

On the other hand, when these crystalline polyester resins are dispersed and contained in a compatible non-crystalline resin, for example, when the non-crystalline resin is a polyester resin, sufficient dispersion can be obtained by dispersing it by melt-kneading. Only a toner having the same defect as that obtained when dispersed in an amorphous resin having poor compatibility was obtained.
When these crystalline and amorphous polyester resins are finely dispersed in water, mixing the amorphous polyester resin in water requires excessive energy and the assistance of an organic solvent, which is costly. When the alkali is used as the dispersion aid, there is a problem that the performance deteriorates due to hydrolysis. Furthermore, the tin-based catalysts that have been widely used in the past to design the molecular weight so that this amorphous polyester resin obtains good fixability have the disadvantage of contaminating the environment, and support good fixability. At present, no safe resin has been obtained.

  On the other hand, a method using a low melting crystalline resin containing a long chain (meth) acrylic acid ester has been proposed (Patent Document 6). These monomers can be easily emulsified and are very suitable for aqueous toner production. However, when such a long-chain (meth) acrylic acid ester polymer is used as a binder resin, brittleness is developed, the fixed image strength is remarkably deteriorated, and image defects are easily caused by bending or scratching ( Patent Document 6). Moreover, when long chain (meth) acrylic acid ester and a vinyl-type monomer are copolymerized (patent documents 7-8), melting | fusing point will fall and blocking resistance will be deteriorated.

  In addition, a method for producing a latex using a long-chain (meth) acrylic acid ester polymer as a core shell with an amorphous resin and using the long-chain (meth) acrylic acid ester polymer as a release agent has also been proposed (Patent Literature). 9). However, these latexes have a high storage elastic modulus in a state where the long-chain (meth) acrylate polymer is melted, and even if the toner is made into a toner, the long-chain (meth) acrylate polymer alone has a releasing effect. Insufficient offset, low gloss, and large latex particle size, there was a problem that coarse powder was generated when agglomerated with the pigment.

  When the toner suitable for low-temperature fixing used in the present invention is used in a high-speed electrophotographic process, it becomes easy to slip through the cleaning blade particularly when the sphericity is large. It is necessary to increase the contact pressure of the cleaning blade against the photosensitive member. In such a case, there is a problem that an external additive, wax, or the like, which is a toner component, is fixed on the photoreceptor and cannot be removed, so that a so-called filming phenomenon easily occurs and remains as an image defect. In order to solve this, a measure to increase the surface hardness of the outermost surface layer of the photosensitive member is generally used, and there is an effect of suppressing the biting of the external additive into the photosensitive member, particularly at the initial use. In order to increase the surface hardness, efforts have been made to put inorganic fine particles in the outermost layer as a filler, or to make the outermost layer into a thermosetting or photocurable resin. However, when an inorganic filler is added, there is always a grain boundary between the inorganic component of the outermost layer and the organic component (resin, charge transporting material, etc.). As a result, the surface gradually causes brittle fracture due to the uniform part, causing poor cleaning and filming, the detached filler component becomes a new source of contamination, and the hard inorganic filler wears the cleaning blade. Risk of poor cleaning. In the case of a curable resin, there is too little film abrasion at the time of endurance, so there are no deposits of discharge products that should originally be scraped and removed, and ozone or nitrogen oxide deterioration components on the surface of the photoreceptor. It remains and is likely to cause image defects. Therefore, none of them was sufficient as a countermeasure. Therefore, it has been necessary to find a photoreceptor surface layer that exhibits surface mechanical properties that match a toner having a small particle size and low-temperature fixability as in the present application.

The present inventor has made studies in order to solve the above-mentioned problems. An electrophotographic photosensitive material containing a toner in which a long-chain (meth) acrylate polymer is dispersed in a vinyl copolymer and a polyester resin on the outermost surface. We found that the problem can be solved by using the body. By using a polyester resin for the outermost surface layer of the photoreceptor, the elastic deformation rate is increased while the surface hardness is high, and even when the toner is used, both filming and poor cleaning are suppressed regardless of the blade contact pressure. It has been found that an image forming apparatus that stably forms a high-quality image can be provided. The present invention is based on this finding, and the gist of the present invention is as follows.
(1) In an image forming apparatus having an electrostatic charge image developing toner and an electrophotographic photosensitive member, the toner contains at least a binder resin, a colorant and a wax, and the binder resin contains a long-chain (meth) acrylic ester. The first step for polymerizing and the second step for polymerizing the vinyl monomer in the presence of the polymer obtained in the first step, and the electrophotographic photosensitive member is the polyester resin first. An image forming apparatus comprising the surface layer.
(2) The image forming apparatus according to (1), wherein the polyester resin is represented by the following formula [1].

(In the formula [1], Ar ^{1 to} Ar ⁴ each independently represents an arylene group which may have a substituent, and X represents a single bond, an oxygen atom, a sulfur atom, or the following formula [2]. Or a group represented by the following formula [3], wherein R ¹ and R ² in the formula [2] each independently represent a hydrogen atom, an alkyl group, or an aryl group, and R ¹ and R 2 ² may be bonded to form a ring, and R ³ in the formula [3] is an alkylene group, an arylene group, or a group represented by the following formula [4], which is represented by the formula [4] R ⁴ and R ⁵ therein independently represent an alkylene group, Ar ⁵ represents an arylene group, and k represents an integer of 0 or more.)

In the formula [1], Y is a single bond, an oxygen atom, a sulfur atom, or a group represented by the following formula [5]. In the formula [5], R ⁶ and R ⁷ are each independently hydrogen. It represents an atom, an alkyl group, an alkoxy group, or an aryl group, and R ⁶ and R ⁷ may combine to form a ring.

(3) X in the formula [1] is an oxygen atom, a sulfur atom, a group represented by the formula [2], or a group represented by the formula [3], The image forming apparatus according to 2).
(4) The image forming apparatus according to (1), wherein the polyester resin includes a structure represented by the following formula [6].

(5) The image formation according to any one of (1) to (4), wherein a toner containing at least a component having 22 or more carbon atoms is used in the ester portion of the long-chain acrylate ester. apparatus.
(6) The image forming apparatus according to any one of (1) to (5), wherein the long-chain (meth) acrylic ester used in the first step is obtained by high-pressure mechanical emulsification.
(7) The image forming apparatus according to any one of (1) to (6), wherein a radical polymerization initiator is used at least during the polymerization in the second step.
(8) The long-chain (meth) acrylic acid ester polymer obtained in the first step is contained in the binder resin in an amount of 1% by mass to 50% by mass, (1) to (7) ).
(9) The image forming apparatus according to any one of (1) to (8), wherein a melting point (Tm) of the toner is Tm ≦ 80 ° C.
(10) The image forming apparatus according to any one of (1) to (9), wherein a melting point (Tm) of the toner satisfies Tm ≧ 40 ° C.
(11) When the storage elastic modulus of the polymer obtained in the first step at 1 Hz at a temperature 20 ° C. higher than the melting point (Tm) of the toner is G ′ (Tm + 20), the following equation (a) is satisfied. The image forming apparatus according to any one of (1) to (10), wherein a toner characterized by the above is used.

G ′ (Tm + 20) ≦ 1 × 10 ³ [Pa] (a)
(12) The image according to any one of (1) to (11), wherein the toner has an endothermic peak at a temperature rise of 45 ° C. or lower in a DSC curve measured by a differential scanning calorimeter. Forming equipment.

  According to the present invention, it is possible to provide an image forming apparatus having both low-temperature fixability and blocking resistance of toner and stable image quality.

1 is a schematic diagram illustrating a main configuration of an embodiment of an image forming apparatus of the present invention. 1 is an X-ray diffraction pattern of oxytitanium phthalocyanine used in Examples. It is the graph which showed the load curve with respect to the indentation depth of a photoconductor.

[1. toner]
First, the toner used in the present invention will be described.
The toner used in the present invention contains at least a colorant, a binder resin, and a wax, and may contain a charge control agent, an external additive, and the like as necessary. The toner used in the present invention is preferably produced by a wet method.

Examples of the wet method include a suspension polymerization method, an emulsion polymerization aggregation method, and a melt suspension method.
The suspension polymerization method is usually obtained by dissolving a colorant and wax in a binder resin monomer, and then suspending the monomer solution as monomer droplets in an aqueous medium by mechanical shearing force and performing polymerization. .
As the emulsion polymerization aggregation method, the polymer primary monomer is usually obtained by emulsifying the polymerizable monomer of the binder resin in an aqueous medium containing a polymerization initiator and an emulsifier, and polymerizing the polymerizable monomer with stirring. In this method, toner particles are produced by obtaining particles, adding a colorant and, if necessary, a charge control agent to aggregate the polymer primary particles, and aging the resulting aggregated particles.

The melt suspension method is usually obtained by dissolving a binder resin, wax or the like in a solvent to obtain an oil phase, suspending the oil phase as oil droplets in an aqueous medium, and then removing the solvent. It is done.
The toner binder resin used in the present invention is a first step of polymerizing a long-chain (meth) acrylic acid ester, and a first step of polymerizing a vinyl monomer in the presence of the polymer obtained in the first step. 2
It is manufactured through a process.

In the first step, a monomer (long chain (meth) acrylic acid ester) solution is prepared, and the monomer solution is dispersed in oil droplets in an aqueous medium (for example, an aqueous surfactant solution). A dispersion of resin particles is prepared by polymerizing the resin. Further, if necessary, a monomer solution may be prepared by dissolving a crystalline substance such as wax in the monomer.
In the second step, a monomer (vinyl monomer) is further added to the dispersion of resin particles obtained in the first step, and the monomer is polymerized in the presence of the resin particles. Resin particles are formed.

The monomers used in the first step and the second step for obtaining the binder resin for the toner used in the present invention may be used singly or in combination.
By obtaining the toner binder resin through the first step and the second step, an electrostatic charge image developing toner excellent in low-temperature fixability and anti-blocking property can be obtained.
Although it is not clear, it is considered that the above-described effects of the electrostatic image developing toner used in the present invention are expressed by the following mechanism. First, a polymer having a single melting point is obtained by first polymerizing a long-chain (meth) acrylic acid ester. Thereafter, since the vinyl monomer is polymerized as the second step, it is possible to suppress the generation of a low melting point component that is considered to be generated by copolymerization of the long-chain (meth) acrylic acid ester and the vinyl monomer.

  Moreover, when polymerizing a vinyl-type monomer, the radical derived from a monomer or an initiator draws out tertiary hydrogen in the acrylic acid part of some long chain (meth) acrylic acid ester polymers, and is grafted. A polymer is formed. This graft polymer becomes a compatibilizer, stabilizes the interface between the long-chain (meth) acrylate polymer and the vinyl polymer, which are crystalline resins, and the long-chain (meth) acrylate in the vinyl copolymer. By obtaining a toner in which a polymer is dispersed, it is considered that a toner having excellent low-temperature fixability and blocking resistance can be produced.

The long chain (meth) acrylic acid ester used in the toner used in the present invention may be linear or branched, and may be unsaturated. Here, the long chain (meth) acrylic acid ester refers to an ester having an average carbon number of 10 or more.
When a long-chain (meth) acrylic acid ester is used alone, the lower limit of the number of carbon atoms in the ester portion is 18 or more, preferably 20 or more, and more preferably 22 or more in order to make the toner melting point a preferable range. It is.

  Further, in the toner used in the present invention, the long chain (meth) acrylic acid ester may be used alone or in combination, but the carbon number of the ester part of the long chain (meth) acrylic acid ester when mixed may be The average is preferably 18 or more, more preferably 19 or more, and particularly preferably 20 or more in order to make the toner melting point within a preferable range. On the other hand, the average upper limit of the carbon number of the ester moiety is usually 40 or less, preferably 36 or less, more preferably 32 or less, from the viewpoint of the melting point of the toner.

  Moreover, it is preferable that the component whose carbon number of the ester part of long-chain (meth) acrylic acid ester is 22 or more is contained at least. Further, the component having 22 or more carbon atoms in the ester portion of the long-chain (meth) acrylate ester tends to have a preferable toner melting point, and therefore preferably 1% or more of the long-chain (meth) acrylate ester. % Or more is more preferable, and 10% or more is particularly preferable. Also, it may be 100%.

Furthermore, in the long-chain (meth) acrylic acid ester used in the toner used in the present invention, it is preferable for the optimization of the toner melting point by crystallization that the component having 12 or more carbon atoms in the ester moiety is 50% or more. Tend. When the number of carbon atoms in the ester portion is too small, the melting point becomes low and the blocking resistance tends to be poor.
The carbon number of the ester portion of the long chain (meth) acrylic acid ester can be measured by DSC, NMR, MS or the like.

Further, it is preferable that the long chain (meth) acrylate used in the toner used in the present invention contains at least a long chain acrylate. When a long-chain acrylate ester is contained, a graft polymer is easily generated due to extraction of tertiary hydrogen, and the compatibility with the vinyl copolymer is increased, so that a uniform toner tends to be obtained.
The (meth) acrylic acid ester used in the toner used in the present invention is not particularly limited, but tetracosyl acrylate, behenyl acrylate, icosyl acrylate, stearyl acrylate, cetyl acrylate, mistyryl acrylate, tetracosyl methacrylate, behenyl Monomers such as methacrylate, icosyl methacrylate, stearyl methacrylate, cetyl methacrylate, and mystyryl methacrylate are preferable for achieving low-temperature fixing.

  In the toner used in the present invention, the melting point of the long chain (meth) acrylate polymer is preferably 100 ° C. or lower, more preferably 80 ° C. or lower, and particularly preferably 70 ° C. or lower. The melting point is preferably 40 ° C. or higher, more preferably 50 ° C. or higher. If the melting point is too high, the effect of reducing the fixing temperature will be poor, and if the melting point is too low, problems may occur in the caking property and storage stability.

Further, when the storage elastic modulus of the polymer obtained in the first step under the conditions of (Tm + 20) ° C. and 1 Hz, which is 20 ° C. higher than the toner melting point (Tm) after the external addition, is G ′ (Tm + 20), It is preferable that the condition of the following formula (a) is satisfied.
G ′ (Tm + 20) ≦ 1 × 10 ³ [Pa] (a)
Further, it is more preferable that G ′ (Tm + 20) ≦ 1 × 10 ² Pa. Furthermore, it is most preferable that G ′ (Tm + 20) ≦ 5 × 10 ¹ Pa. The lower limit of G ′ (Tm + 20) is not particularly limited because the binder resin melts and becomes the measurement limit value of the measuring machine.

When the formula (2) is satisfied, low-temperature fixing is possible. In addition, the binder resin can be easily deformed below the melting point, and the thermal conductivity is improved during fixing. As a result, the uniformity of the fixed image surface is increased, and a toner having particularly excellent gloss performance can be obtained.
The amount of the long-chain (meth) acrylic acid ester polymer used in the second step for obtaining the toner binder resin used in the present invention may be charged so as to be 1 part by mass or more in 100 parts by mass of the binder resin. Preferably, it is 2 parts by mass or more, more preferably 5 parts by mass or more. Moreover, it is preferable to prepare in 50 mass parts or less in 100 mass parts of binder resin, More preferably, it is 45 mass parts or less, More preferably, it is 40 mass parts or less. If the content of the long-chain (meth) acrylic acid ester polymer in the binder resin is too small, the performance such as low-temperature fixability may not be sufficient. If it is too much, the fixed image strength deteriorates, and bending or scratching occurs. May cause image loss.

The polymerization time in the first step for obtaining the binder resin for the toner used in the present invention is not particularly limited, but the polymerization is preferably carried out until the residual monomer after polymerization is less than 1%, usually 5 minutes. The polymerization time is preferably 3 hours or less, and the polymerization is preferably performed at a temperature equal to or higher than the melting point of the monomer used in the first step.
The long-chain (meth) acrylic acid ester used in the first step, which is the production step of the toner binder resin used in the present invention, is mixed with melt, water, surfactant, etc., if necessary, and then subjected to high-pressure mechanical emulsification. It is preferable to do so. Moreover, you may perform a high pressure mechanical emulsification with a wax. By performing high-pressure mechanical emulsification, the diameter of the long-chain (meth) acrylic acid ester or wax dispersion can be reduced. By reducing the diameter of the dispersion before polymerization, the specific surface area of the dispersion increases, and the graft reaction tends to proceed.

In the toner used in the present invention, the volume average particle size of the long chain (meth) acrylic acid ester and wax dispersion is preferably 0.03 μm or more, more preferably 0.05 μm or more, and particularly preferably 0.1 μm or more. . Further, it is preferably 2 μm or less, more preferably 1 μm or less, and particularly preferably 0.5 μm or less.
The apparatus used for the high-pressure mechanical emulsification of the toner used in the present invention is not particularly limited, but it is preferable to use an apparatus having a pump pressure of 5 MPa or more, more preferably 10 MPa or more.

The high-pressure mechanical emulsification is preferably carried out at a temperature equal to or higher than the melting point of the long-chain (meth) acrylic acid ester and the wax. If the emulsification temperature is too low, the particle size of the dispersion tends to be difficult to decrease.
As the vinyl monomer used in the second step, which is a process for producing the toner binder resin used in the present invention, monomers conventionally used in toner binder resins can be used as appropriate. .

For example, as a monomer, a polymerizable monomer having an acidic group (hereinafter sometimes simply referred to as an acidic monomer), a polymerizable monomer having a basic group (hereinafter simply referred to as a basic monomer) A polymerizable monomer having no acidic group or basic group (hereinafter, also referred to as other monomer) may be used. it can.
Examples of the monomer include polymerizable monomers having a carboxyl group such as acrylic acid, methacrylic acid, maleic acid, fumaric acid and cinnamic acid, polymerizable monomers having a sulfonic acid group such as sulfonated styrene, Examples thereof include polymerizable monomers having a sulfonamide group such as vinylbenzenesulfonamide. Examples of the basic monomer include aromatic vinyl compounds having an amino group such as aminostyrene, nitrogen-containing heterocyclic-containing polymerizable monomers such as vinylpyridine and vinylpyrrolidone, dimethylaminoethyl acrylate, diethylaminoethyl methacrylate, etc. And (meth) acrylic acid ester having an amino group. These acidic monomers and basic monomers may be used singly or as a mixture of a plurality of types, and may exist as a salt with a counter ion. Among these, it is preferable to use an acidic monomer, more preferably acrylic acid and / or methacrylic acid.

  Also, styrenes such as styrene, methyl styrene, chlorostyrene, dichlorostyrene, p-tert-butyl styrene, pn-butyl styrene, pn-nonyl styrene, methyl acrylate, ethyl acrylate, propyl acrylate, Acrylic esters such as n-butyl acrylate, isobutyl acrylate, hydroxyethyl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, methacrylic acid Methacrylic acid esters such as hydroxyethyl acid, 2-ethylhexyl methacrylate, acrylamide, N-propylacrylamide, N, N-dimethylacrylamide, N, N-dipropylacrylamide, N, N-dibutyla Riruamido and the like, the polymerizable monomer may be used singly, or may be used in combination.

  Further, when the binder resin is a cross-linked resin, a polyfunctional monomer having radical polymerizability is used together with the above-mentioned monomers, for example, divinylbenzene, hexanediol diacrylate, ethylene glycol dimethacrylate, diethylene glycol diester. Examples include methacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, neopentyl glycol dimethacrylate, neopentyl glycol diacrylate, and diallyl phthalate. It is also possible to use a polymerizable monomer having a reactive group in a pendant group, such as glycidyl methacrylate, methylol acrylamide, acrolein and the like. Among these, radically polymerizable bifunctional polymerizable monomers are preferable, and divinylbenzene and hexanediol diacrylate are particularly preferable. These polyfunctional polymerizable monomers may be used alone or as a mixture of plural kinds.

The polymerization time in the second step for obtaining the binder resin of the toner used in the present invention can be appropriately adjusted by the addition method of the monomer or emulsifier used in the second step, and is not particularly limited. Polymerization is preferably carried out until the remaining monomer is less than 1%. Moreover, it is preferable to perform superposition | polymerization at the temperature more than melting | fusing point of the polymer obtained at the 1st process.
In the production of the toner used in the present invention, the polymerization initiator used in the step of producing the binder resin is not particularly limited in the first step and the second step, but a known polymerization initiator may be used as necessary. The polymerization initiator can be used alone or in combination of two or more. The polymerization initiator includes a radical polymerization initiator and an ionic polymerization initiator. A radical polymerization initiator is preferable for use in water, and when a radical polymerization initiator is used in the second step of obtaining a binder resin, This is particularly preferable because a graft reaction due to hydrogen abstraction is likely to occur.

The radical polymerization initiator includes an organic polymerization initiator and an inorganic polymerization initiator, and hydrogen peroxide and an organic polymerization initiator are preferably used. Inorganic polymerization initiators such as potassium persulfate, sodium persulfate, and ammonium persulfate may need to be used in a large amount, and since a hydrophilic group is generated at the polymerization terminal, there is a tendency to adversely affect charging characteristics.
In particular, as the hydrogen peroxide and the organic polymerization initiator, in the second step of obtaining the binder resin, a ketone peroxide that easily undergoes a graft reaction by hydrogen abstraction and a hydroperoxide containing hydrogen peroxide are preferable. Furthermore, hydroperoxide containing hydrogen peroxide is most preferable.

These polymerization initiators may be added to the polymerization system before, simultaneously with the addition of the monomer, or after the addition, and these addition methods may be combined as necessary.
In the toner used in the present invention, a known chain transfer agent can be used as necessary. Specific examples of the chain transfer agent include t-dodecyl mercaptan, 2-mercaptoethanol, diisopropylxanthogen, carbon tetrachloride, trichlorobromomethane and the like. The chain transfer agent may be used alone or in combination of two or more, and is used in an amount of 0 to 5% by mass based on the polymerizable monomer.

  In the toner used in the present invention, a known suspension stabilizer can be used as necessary. Specific examples of the suspension stabilizer include calcium phosphate, magnesium phosphate calcium hydroxide, magnesium hydroxide and the like. These may be used alone or in combination of two or more, and may be used in an amount of 1 part by mass or more and 10 parts by mass or less with respect to 100 parts by mass of the polymerizable monomer.

Both the polymerization initiator and the suspension stabilizer may be added to the polymerization system at any time before, simultaneously with, or after the addition of the polymerizable monomer. You may combine.
In addition, a pH adjuster, a polymerization degree adjuster, an antifoaming agent, and the like can be appropriately added to the reaction system.

In the toner used in the present invention, when the binder resin is polymerized by emulsion polymerization, known emulsifiers can be used. Among cationic surfactants, anionic surfactants, and nonionic surfactants, One or two or more emulsifiers selected from can be used in combination.
Examples of the cationic surfactant include dodecyl ammonium chloride, dodecyl ammonium bromide, dodecyl trimethyl ammonium bromide, dodecyl pyridinium chloride, dodecyl pyridinium bromide, hexadecyl trimethyl ammonium bromide, and examples of the anionic surfactant include And fatty acid soap such as sodium stearate and sodium dodecanoate, sodium dodecyl sulfate, sodium dodecylbenzenesulfonate, sodium lauryl sulfate and the like. Nonionic surfactants include, for example, polyoxyethylene dodecyl ether, polyoxyethylene hexadecyl ether, polyoxyethylene nonyl phenyl ether, polyoxyethylene lauryl ether, polyoxyethylene sorbitan monooleate ether, monodecanoyl sucrose, etc. Is mentioned.

  In the toner used in the present invention, the amount of the emulsifier is preferably 0.1 parts by mass or more and 10 parts by mass or less with respect to 100 parts by mass of the polymerizable monomer. In addition, these emulsifiers can be used as protective colloids, for example, one or more of partially or completely saponified polyvinyl alcohols such as polyvinyl alcohol and cellulose derivatives such as hydroxyethyl cellulose.

  In the toner used in the present invention, the volume average particle size of the polymer primary particles after multistage polymerization obtained by emulsion polymerization is usually 0.03 μm or more, preferably 0.05 μm or more, more preferably 0.1 μm or more. Usually, it is 3 μm or less, preferably 2 μm or less, more preferably 1 μm or less. If the particle size is too small, it may be difficult to control the aggregation rate in the aggregation process. If the particle size is too large, the particle size of the toner particles obtained by aggregation tends to be large. It may be difficult to obtain toner.

  As the wax used in the toner of the present invention, known waxes can be arbitrarily used. Specifically, olefin waxes such as low molecular weight polyethylene, low molecular weight polypropylene, and copolymerized polyethylene, paraffin wax, and behen. An ester wax having a long chain aliphatic group such as behenyl acid, montanate ester, stearyl stearate, a plant wax such as hydrogenated castor oil carnauba wax, a ketone having a long chain alkyl group such as distearyl ketone, an alkyl group Examples include silicones, higher fatty acids such as stearic acid, long chain fatty acid alcohols, long chain fatty acid polyhydric alcohols such as pentaerythritol, and their partial ester bodies, higher fatty acid amides such as oleic acid amide and stearic acid amide, etc. Preferably paraffin Box or a hydrocarbon, such as Fischer-Tropsch wax, ester wax, and silicone waxes.

  In the toner used in the present invention, a hydrocarbon wax is preferable because of its low compatibility with resins generally used as a binder resin for a toner obtained by a polymerization method. If a wax that is too compatible with the binder resin is used, the wax dissolves in the resin and changes the resin characteristics, making it difficult to achieve both fixing and blocking resistance, and exposing the wax to the toner surface. It may adversely affect the toner performance, for example, it may cause image quality degradation due to release from the toner.

  In the toner used in the present invention, the wax may be used alone or in combination. Among these waxes, in order to improve fixability, the melting point of the wax is preferably 110 ° C. or lower, more preferably 90 ° C. or lower, and particularly preferably 80 ° C. or lower. As a minimum of melting | fusing point, 40 degreeC or more is preferable, More preferably, it is 50 degreeC or more. If the melting point is too high, the effect of reducing the fixing temperature is poor, and if the melting point is too low, problems may occur in the caking property and storage stability.

  In the toner used in the present invention, the amount of wax is preferably 1 part by mass or more, more preferably 2 parts by mass or more, and further preferably 5 parts by mass or more per 100 parts by mass of the toner. Moreover, it is preferable that it is 40 mass parts or less, More preferably, it is 35 mass parts or less, More preferably, it is 30 mass parts or less. If the wax content in the toner is too low, performance such as high temperature offset property may not be sufficient, and if the content is too high, the blocking resistance may not be sufficient, or the wax may leak from the toner. It may become contaminated.

As the colorant for the toner used in the present invention, a known colorant can be arbitrarily used. Specific examples of colorants include carbon black, aniline blue, phthalocyanine blue, phthalocyanine green, Hansa yellow, rhodamine dyes, chrome yellow, quinacridone, benzidine yellow, rose bengal, triallylmethane dye, monoazo, Any known dyes and pigments such as disazo dyes and condensed azo dyes can be used alone or in combination. In the case of a full color toner, it is preferable to use benzidine yellow for yellow, monoazo and condensed azo dyes, magenta for quinacridone and monoazo dyes, and cyan for phthalocyanine blue. The colorant is preferably used so as to be 3 parts by mass or more and 20 parts by mass or less with respect to 100 parts by mass of the polymer primary particles.

  The blending of the colorant in the emulsion polymerization aggregation method is usually performed in an aggregation step. A dispersion of polymer primary particles and a dispersion of colorant particles are mixed to form a mixed dispersion, which is then aggregated to form a particle aggregate. The colorant is preferably used in the state of being dispersed in water in the presence of an emulsifier, and the volume average particle diameter of the colorant particles is 0.01 μm or more, more preferably 0.05 μm or more, and more preferably 3 μm or less. 1 μm.

  When a charge control agent is used in the toner used in the present invention, any known one can be used alone or in combination. For example, a quaternary ammonium salt, basic / electron can be used as a positive charge control agent. As the negatively chargeable charge control agent, metal chelates, organic acid metal salts, metal-containing dyes, nigrosine dyes, amide group-containing compounds, phenol compounds, naphthol compounds and their metal salts, urethane Examples include a bond-containing compound and an acidic or electron-withdrawing organic substance.

  In addition, when the electrostatic image developing toner used in the present invention is used as a toner other than a black toner in a color toner or a full color toner, a charge control agent that is colorless or light-colored and does not impair the color tone of the toner may be used. Preferably, for example, a quaternary ammonium salt compound is used as a positively chargeable charge control agent, and a metal salt, metal complex, or benzylic acid of salicylic acid or alkylsalicylic acid with chromium, zinc, aluminum or the like as a negatively chargeable charge control agent. Hydroxynaphthalene compounds such as metal salts, metal complexes, amide compounds, phenolic compounds, naphthol compounds, phenolamide compounds, 4,4′-methylenebis [2- [N- (4-chlorophenyl) amido] -3-hydroxynaphthalene] preferable.

  In the toner used in the present invention, when a charge control agent is contained in the toner by the emulsion polymerization aggregation method, the charge control agent is added together with a polymerizable monomer or the like at the time of emulsion polymerization, or polymer primary particles and a colorant. Or the like in the agglomeration step, or after the polymer primary particles and the colorant are agglomerated to almost the target particle size. Among these, it is preferable to disperse the charge control agent in water using a surfactant and add it to the aggregation step as a dispersion having a volume average particle size of 0.01 μm or more and 3 μm or less.

The toner used in the present invention may be produced by any polymerization method such as a suspension polymerization method, an emulsion polymerization aggregation method, or a dissolution suspension method, and is not particularly limited.
In the toner used in the present invention, as a method for producing a suspension polymerization toner, a colorant, a polymerization initiator, and, if necessary, a wax, a polar resin, a charge control agent, An additive such as a cross-linking agent is added to prepare a monomer composition that is uniformly dissolved or dispersed. This monomer composition is dispersed in an aqueous medium containing a dispersion stabilizer and the like. Preferably, granulation is performed by adjusting the stirring speed and time so that the droplets of the monomer composition have a desired toner particle size. Thereafter, polymerization is performed by stirring to such an extent that the particle state is maintained and the sedimentation of the particles is prevented by the action of the dispersion stabilizer. These are collected by washing and filtration, and dried to obtain toner mother particles. Further, if necessary, toner can be obtained by external addition or the like.

  As a production method of the emulsion polymerization aggregation method, polymer primary particles of a binder resin monomer obtained by emulsion polymerization, a colorant dispersion, a wax dispersion, etc. are prepared, and these are dispersed in an aqueous medium. By carrying out heating or the like, it undergoes an agglomeration step and an aging step. These are collected by washing and filtration, and dried to obtain toner mother particles. Further, if necessary, toner can be obtained by external addition or the like.

  In the emulsion polymerization aggregation method, the aggregation is usually carried out in a tank equipped with a stirrer, but there are a heating method, a method of adding an electrolyte, and a method of combining them. When polymer primary particles are agglomerated with stirring to obtain particle aggregates of the desired size, the particle size of the particle aggregates is controlled based on the balance between the agglomeration force between the particles and the shearing force due to agitation. However, the cohesive force can be increased by heating or adding an electrolyte.

In the present invention, the electrolyte in the case of performing aggregation by adding an electrolyte may be either an organic salt or an inorganic salt. Specifically, NaCl, KCl, LiCl, Na ₂ SO ₄ , K ₂ SO ₄ , Li ₂ SO ₄ , MgCl ₂ , CaCl ₂ , MgSO ₄ , CaSO ₄ , ZnSO ₄ , Al ₂ (SO ₄ ) ₃ , Fe ₂ (SO ₄ ) ₃ , CH ₃ COONa, C ₆ H ₅ SO ₃ Na, etc. It is done. Of these, inorganic salts having a divalent or higher polyvalent metal cation are preferred.

  In the toner used in the present invention, the amount of electrolyte added varies depending on the type of electrolyte, target particle size, etc., but is preferably 0.05 parts by mass or more with respect to 100 parts by mass of the solid component of the mixed dispersion. 0.1 part by mass or more is more preferable. Further, it is preferably 25 parts by mass or less, more preferably 15 parts by mass or less, and particularly preferably 10 parts by mass or less. If the amount added is too small, the progress of the agglutination reaction will be slow, and there will be problems such as fine powder of 1 μm or less remaining after the agglomeration reaction, or the average particle size of the obtained particle aggregate will not reach the target particle size. If the amount is too large, rapid aggregation tends to occur, making it difficult to control the particle diameter, and the resulting aggregated particles may include problems such as coarse powders and irregular shapes. When the aggregation is performed by adding an electrolyte, the aggregation temperature is 20 ° C. or higher, more preferably 30 ° C. or higher, and 70 ° C. or lower, more preferably 60 ° C. or lower.

The aggregation temperature in the case of performing aggregation only by heating without using an electrolyte is preferably (Tg-20) ° C. or higher, and more preferably (Tg-10) ° C. or higher, where Tg is the glass transition temperature of the polymer primary particles. . Moreover, Tg or less is preferable and (Tg-5) degree C or less is preferable.
The time required for agglomeration is optimized depending on the shape of the apparatus and the processing scale, but in order for the toner particle size to reach the target particle size, it is usually held at the predetermined temperature for at least 30 minutes. desirable. The temperature rise until reaching the predetermined temperature may be raised at a constant rate, or may be raised stepwise.

On the surface of the particle aggregate after the above-described aggregation treatment, particles with resin fine particles attached or fixed can be formed as necessary. By attaching or fixing resin fine particles whose properties are controlled to the surface of the particle aggregate, the chargeability and heat resistance of the obtained toner may be improved, and the toner effect used in the present invention is more remarkable. be able to.
When resin fine particles having a glass transition temperature higher than the glass transition temperature of the polymer primary particles are used as the resin fine particles, it is preferable because blocking resistance can be further improved without impairing fixability. The volume average particle size of the resin fine particles is preferably 0.02 μm or more, and more preferably 0.05 μm or more. Moreover, 3 micrometers or less, Furthermore, 1.5 micrometers or less are preferable. As the resin fine particles, those obtained by emulsion polymerization of monomers similar to the polymerizable monomers used for the above-described polymer primary particles can be used.

The resin fine particles are usually used as a dispersion dispersed in water or a liquid mainly composed of water using a surfactant. However, when a charge control agent is added after the aggregation treatment, charge control is performed on the dispersion containing particle aggregates. It is preferable to add resin fine particles after adding the agent.
In order to increase the stability of the particle aggregate obtained in the aggregation step, it is preferable to perform fusion in the aggregated particles in the aging step after the aggregation step. The temperature of the ripening step is preferably not less than Tg of the polymer primary particles, more preferably not less than 5 ° C higher than Tg, and preferably not more than 80 ° C higher than Tg, more preferably not less than 50 ° C higher than Tg. It is as follows. The time required for the aging step varies depending on the shape of the target toner, but after reaching the glass transition temperature or higher of the polymer primary particles, it is usually held for 0.1 to 10 hours, preferably 1 to 6 hours. Is desirable.

  In addition, it is preferable to add a surfactant or raise the pH value after the aggregation process, preferably before the aging process or during the aging process. As the surfactant used here, one or more emulsifiers can be selected from the emulsifiers that can be used when producing the polymer primary particles. In particular, the emulsifiers used when producing the polymer primary particles. It is preferable to use the same. Although the addition amount in the case of adding surfactant is not limited, Preferably it is 0.1 mass part or more with respect to 100 mass parts of solid components of a mixed dispersion, More preferably, it is 1 mass part or more, More preferably, it is 3 masses It is preferably 20 parts by mass or less, more preferably 15 parts by mass or less, and still more preferably 10 parts by mass or less. After the aggregation process, before the completion of the ripening process, by adding a surfactant or raising the pH value, it is possible to suppress aggregation of the particle aggregates aggregated in the aggregation process, In some cases, the generation of coarse particles can be suppressed.

  By heat treatment in the aging step, the polymer primary particles in the aggregate are fused and integrated, and the toner particle shape as the aggregate becomes close to a spherical shape. The particle aggregate before the aging step is considered to be an aggregate due to electrostatic or physical aggregation of the polymer primary particles, but after the aging step, the polymer primary particles constituting the particle aggregate are fused to each other. In addition, the shape of the toner particles can be made nearly spherical. According to such an aging process, by controlling the temperature and time of the aging process, the shape of the polymer primary particles is agglomerated, a potato type with advanced fusion, a spherical form with further fusion For example, various shapes of toner can be manufactured according to the purpose.

The toner produced by the polymerization method is separated from the aqueous solvent, washed, dried, subjected to external addition treatment as necessary, and used as an electrostatic image developing toner.
Although water is used as the liquid used for washing, it can be washed with an acid or alkali aqueous solution, and it is preferable to use an inorganic acid such as nitric acid, hydrochloric acid or sulfuric acid, or an organic acid such as citric acid. Moreover, it can also wash | clean with warm water or hot water, and these methods can also be used together. Through such a washing step, the suspension stabilizer, the emulsifier, the unreacted residual monomer and the like can be reduced and removed, which is preferable. In the washing step, the liquid to be washed is subjected to, for example, filtration, decantation, etc., so that the colored particles are made into a thick slurry or wet cake, and the operation for dispersing the toner by adding the liquid for washing to this is repeated. preferable. The colored particles after washing are preferably collected in the form of a wet cake in terms of handling in the subsequent drying step.

In the drying process, a fluidized drying method such as a vibration type fluidized drying method or a circulating fluidized drying method, an airflow drying method, a vacuum drying method, a freeze drying method, a spray drying method, a flash jet method, or the like is used. Operating conditions such as temperature, air volume, and degree of reduced pressure in the drying step are appropriately optimized based on the Tg of the colored particles, the shape, mechanism, size, etc. of the apparatus used.
The volume median diameter of the toner base particles of the toner used in the present invention is preferably 3 μm or more, and more preferably 4 μm or more. Moreover, 10 micrometers or less are preferable, Furthermore, 9 micrometers or less are more preferable, and 7 micrometers or less are still more preferable.

  Further, the shape has an average circularity measured by using a flow type particle image analyzer FPIA-3000, preferably 0.90 or more, more preferably 0.92 or more, further preferably 0.94 or more, preferably Is 0.99 or less, more preferably 0.98 or less. If the average circularity is too small, the image density may be lowered due to deterioration of charging due to poor adhesion of the external additive to the colored particles, and if it is too large, the cleaning may be poor due to the shape of the colored particles.

To the toner used in the present invention, externally added fine particles can be added as necessary to improve toner fluidity and charge control properties. Examples of such externally added fine particles include various inorganic or organic fine particles. It can be used by appropriately selecting from among them.
Inorganic fine particles include silicon carbide, boron carbide, titanium carbide, zirconium carbide, hafnium carbide, vanadium carbide, tantalum carbide, niobium carbide, tungsten carbide, chromium carbide, molybdenum carbide, calcium carbide, and other carbides, boron nitride, titanium nitride. , Various nitrides such as zirconium nitride, various borides such as zirconium boride, various oxides such as titanium oxide, calcium oxide, magnesium oxide, zinc oxide, copper oxide, aluminum oxide, cerium oxide, silica, colloidal silica, titanium Various titanate compounds such as calcium oxide, magnesium titanate and strontium titanate, phosphate compounds such as calcium phosphate, sulfides such as molybdenum disulfide and BR> U den, fluorides such as magnesium fluoride and fluorocarbon, stearin Aluminum acid, steary Various metal soaps such as calcium oxide, zinc stearate, and magnesium stearate, talc, bentonite, various carbon blacks, conductive carbon black, magnetite, ferrite, and the like can be used. As the organic fine particles, fine particles such as styrene resin, acrylic resin, epoxy resin, and melamine resin can be used.

  Among these externally added fine particles, silica, titanium oxide, alumina, zinc oxide, various carbon blacks, conductive carbon blacks, and the like are preferably used. Further, the externally added fine particles are obtained by applying the surface of the inorganic or organic fine particles to a silane coupling agent, a titanate coupling agent, a silicone oil, a modified silicone oil, a silicone varnish, a fluorine silane coupling agent, a fluorine silicone oil, What has been subjected to surface treatment such as hydrophobization with a treating agent such as a coupling agent having an amino group or a quaternary ammonium base can also be used. Two or more kinds of the treatment agents can be used in combination.

The average particle size of the externally added fine particles of the toner used in the present invention is preferably 0.001 μm or more, and more preferably 0.005 μm or more. Moreover, 3 micrometers or less are preferable and 1 micrometer or less is more preferable. Also, a plurality of types having different particle sizes can be blended. The average particle diameter of the externally added fine particles can be determined by observation with an electron microscope.
In addition, the externally added fine particles can be used in combination of two or more different types, can be used in combination with those that have been surface-treated and those that have not been surface-treated, or can be used in combination with those that have been surface-treated differently, A positively chargeable one and a negatively chargeable one can be used in appropriate combination.

The content of the externally added fine particles of the toner used in the present invention is preferably 0.01 parts by mass or more, more preferably 0.1 parts by mass or more, preferably 5 parts by mass with respect to 100 parts by mass of the toner particles. Hereinafter, it is more preferably 3 parts by mass or less.
Examples of the method for adding the externally added fine particles include a method using a high-speed stirrer such as a Henschel mixer, a method using an apparatus capable of applying a compressive shear stress, and the like.

Further, inorganic fine powders such as magnetite, ferrite, cerium oxide, strontium titanate, and conductive titania can be added. The amount of these additives used may be appropriately selected depending on the desired performance, and is preferably 0.05 parts by mass or more and 10 parts by mass or less with respect to 100 parts by mass of the toner.
The melting point (Tm) of the toner after the external addition of the toner used in the present invention is preferably 80 ° C. or less, and more preferably 70 ° C. or less. Moreover, it is preferable that it is 40 degreeC or more, and it is still more preferable that it is 50 degreeC or more. If the melting point is within this range, low-temperature fixing and blocking resistance tend to be compatible.

When the storage elastic modulus at a temperature 50 ° C. higher than the melting point (Tm) of the toner after external addition of the toner used in the present invention is G ′ (Tm + 50 ° C.), G ′ (Tm + 50 ° C.) is 1 × 10 6. ⁶ Pa or less is preferable, and 10 Pa or more is preferable.
When the storage elastic modulus at a temperature 100 ° C. higher than the melting point (Tm) of the toner after the external addition of the toner used in the present invention is G ′ (Tm + 100 ° C.), G ′ (Tm + 100 ° C.) is 1 × 10 6. It is preferably ⁵ Pa or less, and preferably 1 Pa or more.

In the toner used in the present invention, when the storage elastic modulus of the toner after external addition at 50 ° C. is G ′ (50 ° C.), G ′ (50 ° C.) is 1 × 10 It is preferably ⁹ Pa or more.
The toner used in the present invention preferably has an endothermic peak at the time of temperature increase of at least 45 ° C. or less when the temperature is first increased in DSC at a rate of 10 ° C./min. What is the first temperature increase?
The temperature rise from -20 ° C to 100 ° C by DSC is shown before the thermal history is added to the obtained toner. The temperature of the endothermic peak is not particularly limited as long as it is 45 ° C. or lower, but is preferably 20 ° C. or higher, and more preferably 25 ° C. or higher. Further, it may have an endothermic peak other than the above peak at 45 ° C. or higher, and preferably has an endothermic peak at 50 ° C. or higher.

The half-value width of the endothermic peak is preferably 10 ° C. or lower, more preferably 8 ° C. or lower.
Most preferred is 5 ° C or lower. If the full width at half maximum is wide, the blocking resistance tends to deteriorate.
The toner used in the present invention does not have an exothermic peak at 45 ° C. or lower during cooling after the first temperature increase in DSC, and does not have an endothermic peak at 45 ° C. or lower during the second temperature increase. Things are preferable. The second temperature increase refers to a temperature increase from −20 ° C. to 100 ° C. by DSC after cooling to −20 ° C. after the first temperature increase by DSC. The component having an endothermic peak of 45 ° C. or less contained in the toner is compatible with the binder resin after heating, and exhibits no exothermic and endothermic peaks at the subsequent temperature decrease and at the time of the subsequent temperature increase. There is a tendency not to cause low temperature fixability and tack after fixing.

  In order to have an endothermic peak at 45 ° C. or lower, there is a method of adding a wax or crystalline resin having an endothermic peak at 45 ° C. or lower to the toner, but this method has a problem that the blocking resistance of the toner is lowered. There is. In contrast, the toner used in the present invention improved the low-temperature fixability without deteriorating the blocking resistance. Although the reason for this is not clear, a resin composed of a crystalline resin and an amorphous resin and having an endothermic peak at 45 ° C. or lower is contained in the binder resin, and this resin is composed of a crystalline resin and an amorphous resin. It is considered that the low-temperature fixability is improved without deteriorating the blocking resistance because the compatibility with both is high and the toner stays in the toner.

  The electrostatic image developing toner used in the present invention may be used in any form of a two-component developer using toner together with a carrier, or a magnetic or non-magnetic one-component developer not using a carrier. When used as a two-component developer, the carrier may be a magnetic substance such as iron powder, magnetite powder, ferrite powder or the like, or a known material such as a resin-coated surface or a magnetic carrier. As the coating resin of the resin coating carrier, generally known styrene resin, acrylic resin, styrene acrylic copolymer resin, silicone resin, modified silicone resin, fluororesin, or a mixture thereof can be used.

[2. Electrophotographic photoreceptor]
Next, the electrophotographic photosensitive member used in the present invention will be described.
The electrophotographic photosensitive member used in the present invention is not particularly limited as long as the outermost layer containing a polyester resin is provided on a conductive support. Among them, those provided with a photosensitive layer containing a polyester resin on the outermost surface are preferable, and a stacked type photoreceptor in which a charge generation layer and a charge transport layer are stacked is more preferable. 1] It is particularly preferable to contain a polyester resin (polyarylate resin) containing a structural unit represented by the formula.

In the formula [1], Ar ^{1 to} Ar ⁴ each independently represent an arylene group which may have a substituent, and X represents a single bond, an oxygen atom, a sulfur atom, or a group represented by the following formula [2]. Or a group represented by the following formula [3], wherein R ¹ and R ² in the formula [2] each independently represent a hydrogen atom, an alkyl group, or an aryl group, and R ¹ and R ² And R ³ in the formula [3] may be an alkylene group, an arylene group, or a group represented by the following formula [4], and in the formula [4] R ⁴ and R ⁵ in the formula independently represent an alkylene group, and Ar ⁵ represents an arylene group. k represents an integer of 0 or more.

In the formula [1], Y is a single bond, an oxygen atom, a sulfur atom, or a group represented by the following formula [5]. In the formula [5], R ⁶ and R ⁷ are each independently hydrogen. It represents an atom, an alkyl group, an alkoxy group, or an aryl group, and R ⁶ and R ⁷ may combine to form a ring.

<Structure>
In the above formula [1], Ar ^{1 to} Ar ⁴ each independently represents an arylene group which may have a substituent. As carbon number which an arylene group has, it is 6 or more normally, and the upper limit is 20 or less normally, Preferably it is 10 or less, More preferably, it is 6. If the number of carbon atoms is too large, the production cost increases and the electrical characteristics may also deteriorate.

Specific examples of Ar ^{1 to} Ar ⁴ include 1,2-phenylene group, 1,3-phenylene group, 1,4-phenylene group, naphthylene group, anthrylene group, phenanthrylene group, and the like. Among these, the arylene group is preferably a 1,4-phenylene group from the viewpoint of electrical characteristics. An arylene group may be used individually by 1 type, and may be used 2 or more types by arbitrary ratios and combinations.

Specific examples of the substituents for Ar ^{1 to} Ar ⁴ include an alkyl group, an aryl group, a halogen group, and an alkoxy group. Among them, considering the mechanical properties as a binder resin for the photosensitive layer and the solubility in the coating solution for forming the photosensitive layer, the alkyl group is preferably a methyl group, an ethyl group, a propyl group, or an isopropyl group, and is preferably an aryl group. Is preferably a phenyl group or a naphthyl group, a halogen group is preferably a fluorine atom, a chlorine atom, a bromine atom or an iodine atom, and an alkoxy group is preferably a methoxy group, an ethoxy group, a propoxy group or a butoxy group.

In addition, when a substituent is an alkyl group, carbon number of the alkyl group is usually 1 or more, and usually 10 or less, preferably 8 or less, more preferably 2 or less.
More specifically, Ar ³ and Ar ⁴ each independently preferably has a substituent number of 0 or more and 2 or less, more preferably has a substituent from the viewpoint of adhesion, and among these, substitution from the viewpoint of wear resistance. It is particularly preferable that the number of groups is one. Moreover, as a substituent, an alkyl group is preferable and a methyl group is particularly preferable.

From the above viewpoint, at least one of Ar ³ and Ar ⁴ is preferably an arylene group having a substituent.
On the other hand, Ar ¹ and Ar ² each independently preferably have 0 or more and 2 or less substituents, and more preferably have no substituents from the viewpoint of wear resistance.
In the formula [1], X is a single bond, an oxygen atom, a sulfur atom, a group represented by the following formula [2], or a group represented by the following formula [3], R ¹ and R ² each independently represent a hydrogen atom, an alkyl group, or an aryl group, and R ¹ and R ² may be bonded to form a ring such as a cycloalkylidene group. R ^{3 in} [3] is an alkylene group, an arylene group, or a group represented by the following formula [4], and R ⁴ and R ^{5 in} formula [4] are each independently an alkylene group. Ar ⁵ represents an arylene group.

In Formula [1], preferred X includes an oxygen atom, a sulfur atom, a structure represented by Formula [2], or a divalent organic residue having a structure represented by Formula [3].
Examples of the alkyl group of R ¹ and R ² in the formula [2] include a methyl group, an ethyl group, a propyl group, and a butyl group, and examples of the aryl group include a phenyl group and a naphthyl group. In addition, examples of the cycloalkylidene group formed by combining R ¹ and R ² in the formula [2] include a cyclopentylidene group, a cyclohexylidene group, and a cycloheptylidene group. Furthermore, examples of the alkylene group represented by R ³ in the formula [3] include a methylene group, an ethylene group, and a propylene group. Examples of the arylene group represented by R ³ in the formula [3] include a phenylene group and a terphenylene group. Specific examples of the group represented by the formula [4] include a group represented by the following formula [7].

Among these, X is preferably an oxygen atom. At that time, k is preferably 1.
In the above formula [1], Y is a single bond, an oxygen atom, a sulfur atom, or a group represented by the above formula [5].
R ⁶ and R ⁷ in the formula [5] each independently represent a hydrogen atom, an alkyl group, an alkoxy group, an aryl group, or a cycloalkylidene group formed by combining R ⁶ and R ⁷ . Considering the mechanical properties as the binder resin for the photosensitive layer and the solubility in the coating solution for forming the photosensitive layer, R ⁶ and R ⁷ in the formula [5] are preferably phenyl groups and naphthyl groups as aryl groups, As an alkoxy group, a methoxy group, an ethoxy group, and a butoxy group are preferable. Moreover, as an alkyl group, a C1-C10 alkyl group is preferable, More preferably, it is C1-C8, Most preferably, it is C1-2. Considering the simplicity of production of the divalent hydroxyaryl component used for producing the polyester resin, Y is a single bond, —O—, —S—, —CH ₂ —, —CH (CH ₃ ) —, —C (CH ₃ ) ₂ — and cyclohexylene are preferable, —CH ₂ —, —CH (CH ₃ ) —, —C (CH ₃ ) ₂ — and cyclohexylene are particularly preferable, and —CH ₂ is particularly preferable. _{2 -, - CH (CH 3} ) - is.

In the electrophotographic photoreceptor used in the present invention, the polyester resin [1] is preferably a polyester resin having a repeating structure represented by the following general formula [8] when k = 1. In the following general formula [8], Ar ^{16 to} Ar ¹⁹ each independently represent an arylene group which may have a substituent, and R ⁸ represents a hydrogen atom or an alkyl group.

In the general formula [8], Ar ^{16 to} Ar ¹⁹ respectively correspond to the Ar ^{1 to} Ar ⁴ and particularly preferably a phenylene group which may have a substituent. Moreover, as a preferable substituent, it is a hydrogen atom or an alkyl group, Most preferably, it is a methyl group. Further, in the general formula [8], Ar ¹⁸ and Ar ¹⁹ are phenylene groups having a methyl group, and Ar ¹⁶ and Ar ¹⁷ are particularly preferably phenylene groups having no substituent. R ⁸ represents a hydrogen atom or an alkyl group. The alkyl group preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and particularly preferably a methyl group.

<Dicarboxylic acid residue>
The dicarboxylic acid component which is a dicarboxylic acid residue in the polyester resin is represented by the following general formula [9].

Ar ¹ , Ar ² , X, and k in the general formula [9] are as described above, and the dicarboxylic acid residues contained in the formula [9] are represented by the following general formulas [I] to [VI]. Examples of structures that can be illustrated. Here, k is an integer of 0 or more, but an integer of 0 to 5 is preferable from the viewpoint of electrical characteristics and scratch resistance, and more preferably 0 or 1.

  In the structure represented by the general formula [9], preferably, k is 1 and X is an oxygen atom, which is represented by the following general formula [10].

Specific examples of the preferable dicarboxylic acid residue represented by the general formula [10] include diphenyl ether-2,2′-dicarboxylic acid residue, diphenyl ether-2,3′-dicarboxylic acid residue, diphenyl ether-2,4 ′. -Dicarboxylic acid residue, diphenyl ether-3,3'-dicarboxylic acid residue, diphenyl ether-3,4'-dicarboxylic acid residue, diphenyl ether-4,4'-dicarboxylic acid residue and the like. Among these, considering the simplicity of production of the dicarboxylic acid component, diphenyl ether-2,2′-dicarboxylic acid residue, diphenyl ether-2,4′-dicarboxylic acid residue, diphenyl ether-4,4′-dicarboxylic acid Residues are more preferred, and diphenyl ether-4,4′-dicarboxylic acid residues are particularly preferred.

Specific examples of the dicarboxylic acid residue represented by the general formula [9] and k = 0 include phthalic acid residue, isophthalic acid residue, terephthalic acid residue, toluene-2,5-dicarboxylic acid residue P-xylene-2,5-dicarboxylic acid residue, naphthalene-1,4-dicarboxylic acid residue, naphthalene-2,3-dicarboxylic acid residue, naphthalene-2,6-dicarboxylic acid residue, biphenyl-2 , 2′-dicarboxylic acid residue, biphenyl-4,4′-dicarboxylic acid residue, preferably phthalic acid residue, isophthalic acid residue, terephthalic acid residue, naphthalene-1,4-dicarboxylic acid Residue, naphthalene-2,6-dicarboxylic acid residue, biphenyl-2,2′-
A dicarboxylic acid residue, a biphenyl-4,4′-dicarboxylic acid residue, particularly preferably
It is an isophthalic acid residue or a terephthalic acid residue, and it is also possible to use a combination of these dicarboxylic acid residues. Preferable specific examples represented by the general formula [9] include the following formula [6]. The ratio of isophthalic acid residue to terephthalic acid residue is usually 50:50, but can be arbitrarily changed. In that case, the higher the ratio of terephthalic acid residues, the better from the viewpoint of electrical characteristics.

  The polyester resin may be a resin that contains another dicarboxylic acid component and includes the general formula [9] in a part of the structure. Specific examples of other dicarboxylic acid residues include adipic acid residues, suberic acid residues, sebacic acid residues, pyridine-2,3-dicarboxylic acid residues, pyridine-2,4-dicarboxylic acid residues, pyridine -2,5-dicarboxylic acid residue, pyridine-2,6-dicarboxylic acid residue, pyridine-3,4-dicarboxylic acid residue, pyridine-3,5-dicarboxylic acid residue, preferably, These are adipic acid residues and sebacic acid residues, and a plurality of these dicarboxylic acid residues can be used in combination.

  In addition, when it has dicarboxylic acid residue [9] which comprises the polyester resin used for this invention, and the other dicarboxylic acid residue mentioned above, dicarboxylic acid residue [9] which comprises the polyester resin used for this invention However, the number of repeating units is preferably 70% or more, more preferably 80% or more, and particularly preferably 90% or more. Most preferably, it has only the dicarboxylic acid residue [11] constituting the present invention, that is, the case where the dicarboxylic acid residue [9] constituting the present invention is 100% as the number of repeating units.

<Physical properties>
In the polyester resin having a repeating structure represented by the general formula [1], the viscosity average molecular weight is arbitrary as long as the effect of the present invention is not significantly impaired, but is preferably 10,000 or more, more preferably 20,000 or more. Further, the upper limit is preferably 70,000 or less, more preferably 50,000 or less. If the value of the viscosity average molecular weight is too small, the mechanical strength of the polyester resin may be insufficient, and if it is too large, the viscosity of the coating solution for forming the photosensitive layer may be too high and the productivity may decrease. is there. In addition, a viscosity average molecular weight can be measured by the method as described in an Example using an Ubbelohde type capillary viscometer etc., for example.

(Conductive support)
There are no particular restrictions on the conductive support, but for example, metal materials such as aluminum, aluminum alloys, stainless steel, copper and nickel, and conductive powders such as metal, carbon and tin oxide can be added to make the conductive material conductive. Mainly used are resin, glass, paper, or the like obtained by depositing or coating the applied resin material or a conductive material such as aluminum, nickel, or ITO (indium tin oxide) on its surface. These may be used alone or in combination of two or more in any combination and ratio. As a form of the conductive support, a drum form, a sheet form, a belt form or the like is used. Furthermore, a conductive material having an appropriate resistance value may be used on a conductive support made of a metal material in order to control conductivity and surface properties and to cover defects.

  Moreover, when using metal materials, such as an aluminum alloy, as an electroconductive support body, you may use, after giving an anodic oxide film. When an anodized film is applied, it is desirable to perform a sealing treatment by a known method. The surface of the conductive support may be smooth, or may be roughened by using a special cutting method or performing a polishing treatment. Further, it may be roughened by mixing particles having an appropriate particle size with the material constituting the conductive support. In order to reduce the cost, it is possible to use the drawing tube as it is without performing the cutting process.

(Underlayer)
An undercoat layer may be provided between the conductive support and the photosensitive layer described later for improving adhesion and blocking properties. As the undercoat layer, a resin, a resin in which particles such as a metal oxide are dispersed, or the like is used.
Examples of metal oxide particles used for the undercoat layer include metal oxide particles containing one metal element such as titanium oxide, aluminum oxide, silicon oxide, zirconium oxide, zinc oxide, iron oxide, calcium titanate, titanium Examples thereof include metal oxide particles containing a plurality of metal elements such as strontium acid and barium titanate. One kind of these particles may be used alone, or a plurality of kinds of particles may be mixed and used. Among these metal oxide particles, titanium oxide and aluminum oxide are preferable, and titanium oxide is particularly preferable. The surface of the titanium oxide particles may be treated with an inorganic substance such as tin oxide, aluminum oxide, antimony oxide, zirconium oxide, or silicon oxide, or an organic substance such as stearic acid, polyol, or silicon. As the crystal form of the titanium oxide particles, any of rutile, anatase, brookite, and amorphous can be used. Moreover, the thing of a several crystal state may be contained.

In addition, various particle sizes of metal oxide particles can be used. Among these, from the viewpoint of characteristics and liquid stability, the average primary particle size is preferably 10 nm or more and 100 nm or less, and particularly 10 nm or more and 50 nm or less. preferable.
The undercoat layer is preferably formed in a form in which metal oxide particles are dispersed in a binder resin. The binder resin used for the undercoat layer is epoxy resin, polyethylene resin, polypropylene resin, acrylic resin, methacrylic resin, polyamide resin, vinyl chloride resin, vinyl acetate resin, phenol resin, polycarbonate resin, polyurethane resin, polyimide resin, chloride resin. Cellulose esters such as vinylidene resin, polyvinyl acetal resin, vinyl chloride-vinyl acetate copolymer, polyvinyl alcohol resin, polyurethane resin, polyacryl resin, polyacrylamide resin, polyvinyl pyrrolidone resin, polyvinyl pyridine resin, water-soluble polyester resin, nitrocellulose Resin, cellulose ether resin, casein, gelatin, polyglutamic acid, starch, starch acetate, amino starch, zirconium chelate compound, zirconium The organic zirconium compound alkoxide compounds, titanyl chelate compounds, organic titanyl compounds such as titanium alkoxide compounds include known binder resins such as a silane coupling agent. These may be used alone or in combination of two or more in any combination and ratio. Moreover, you may use with the hardening | curing form with the hardening | curing agent. Among these, alcohol-soluble copolymerized polyamides, modified polyamides, and the like are preferable because they exhibit good dispersibility and coatability.

The use ratio of the inorganic particles to the binder resin used in the undercoat layer can be arbitrarily selected, but is usually in the range of 10% by mass or more and 500% by mass or less from the viewpoint of the stability of the dispersion and the coating property. Is preferably used.
The thickness of the undercoat layer can be arbitrarily selected, but is usually preferably in the range of 0.1 μm or more and 20 μm or less from the viewpoint of improving the photoreceptor characteristics and coating properties. A known antioxidant or the like may be mixed in the undercoat layer. For the purpose of preventing image defects, pigment particles, resin particles and the like may be included.

(Photosensitive layer)
As the type of the photosensitive layer, a charge generation material and a charge transport material are present in the same layer and are dispersed in a binder resin, a charge generation layer in which a charge generation material is dispersed in a binder resin, and a charge. Examples include a functional separation type (laminated type) composed of two layers of a charge transport layer in which a transport material is dispersed in a binder resin. The photosensitive layer in the invention may be of any type. In addition, as the laminated photosensitive layer, a charge-generating layer and a charge transport layer are laminated in this order from the conductive support side, and conversely, a charge transport layer and a charge generation layer are formed from the conductive support side. There are reverse laminated photosensitive layers provided in order, and any of them can be adopted, but a forward laminated photosensitive layer that can exhibit the most balanced photoconductivity is preferable.

(Laminated photosensitive layer)
-Charge generation layer In the case of a multilayer type photoreceptor (function-separated type photoreceptor), the charge generation layer is formed by binding a charge generation material with a binder resin.
Examples of the charge generation material include inorganic photoconductive materials such as selenium and its alloys, cadmium sulfide, and organic photoconductive materials such as organic pigments. Organic photoconductive materials are preferred, and organic photoconductive materials are particularly preferable. Pigments are preferred. Examples of organic pigments include phthalocyanine pigments, azo pigments, dithioketopyrrolopyrrole pigments, squalene (squarylium) pigments, quinacridone pigments, indigo pigments, perylene pigments, polycyclic quinone pigments, anthanthrone pigments, and benzimidazole pigments. . Among these, phthalocyanine pigments or azo pigments are particularly preferable. When organic pigments are used as the charge generation material, usually, fine particles of these organic pigments are used in the form of a dispersion layer bound with various binder resins.

  When a metal-free phthalocyanine compound or a metal-containing phthalocyanine compound is used as the charge generation material, a highly sensitive photoreceptor can be obtained with respect to a laser beam having a relatively long wavelength, for example, a laser beam having a wavelength around 780 nm. Further, when an azo pigment such as monoazo, diazo, or trisazo is used, white light, laser light having a wavelength around 660 nm, or laser light having a relatively short wavelength (for example, a wavelength in the range of 380 nm to 500 nm). It is possible to obtain a photoreceptor having sufficient sensitivity to the laser beam).

When using a phthalocyanine pigment as the charge generation material, specifically, metal-free phthalocyanine, copper, indium, gallium, tin, titanium, zinc, vanadium, silicon, germanium, aluminum and other metals or oxides thereof, halides, Those having each crystal form of coordinated phthalocyanines such as hydroxides and alkoxides, and phthalocyanine dimers using oxygen atoms as bridging atoms are used. In particular, titanyl phthalocyanines (also known as oxytitanium) such as X-type, τ-type metal-free phthalocyanine, A-type (also known as β-type), B-type (also known as α-type), D-type (also known as Y-type), which are highly sensitive crystal types Phthalocyanine), vanadyl phthalocyanine, chloroindium phthalocyanine, hydroxyindium phthalocyanine, chlorogallium phthalocyanine such as type II, hydroxygallium phthalocyanine such as type V, μ-oxo-gallium phthalocyanine dimer such as type G and type I, type II, etc. The [mu] -oxo-aluminum phthalocyanine dimer is preferred.

  Among these phthalocyanines, A-type (also known as β-type), B-type (also known as α-type), and powder X-ray diffraction angle 2θ (± 0.2 °) are 27.1 ° or 27.3 °. D-type (Y-type) titanyl phthalocyanine, II-type chlorogallium phthalocyanine, V-type hydroxygallium phthalocyanine, hydroxygallium phthalocyanine having the strongest peak at 28.1 °, or 26. Hydroxygallium phthalocyanine having no peak at 2 °, a clear peak at 28.1 °, and a full width at half maximum W of 25.9 ° of 0.1 ° ≦ W ≦ 0.4 ° G-type μ-oxo-gallium phthalocyanine dimer and the like are particularly preferable.

  The phthalocyanine compound may be a single compound or several mixed or mixed crystal states. As the mixed state in the phthalocyanine compound or crystal state here, those obtained by mixing the respective constituent elements later may be used, or the mixed state in the production / treatment process of the phthalocyanine compound such as synthesis, pigmentation, crystallization, etc. It may be the one that gave rise to. As such treatment, acid paste treatment, grinding treatment, solvent treatment and the like are known. In order to generate a mixed crystal state, as described in JP-A-10-48859, two types of crystals are mixed, mechanically ground and made amorphous, and then converted into a specific crystal state by solvent treatment. The method of doing is mentioned.

  When the organic pigments exemplified above are used as the charge generation material, one kind may be used alone, or two or more kinds of pigments may be mixed and used. In this case, it is preferable to use a combination of two or more kinds of charge generating materials having spectral sensitivity characteristics in different spectral regions of the visible region and the near red region, and among them, a disazo pigment, a trisazo pigment and a phthalocyanine pigment are preferably used in combination. More preferred.

  The binder resin used for the charge generation layer is not particularly limited.For example, polyvinyl butyral resin, polyvinyl formal resin, polyvinyl acetal resin such as partially acetalized polyvinyl butyral resin in which a part of butyral is modified with formal or acetal, Polyarylate resin, polycarbonate resin, polyester resin, modified ether-based polyester resin, phenoxy resin, polyvinyl chloride resin, polyvinylidene chloride resin, polyvinyl acetate resin, polystyrene resin, acrylic resin, methacrylic resin, polyacrylamide resin, polyamide resin, Polyvinyl pyridine resin, cellulose resin, polyurethane resin, epoxy resin, silicone resin, polyvinyl alcohol resin, polyvinyl pyrrolidone resin, casein, vinyl chloride Vinyl chloride-vinyl acetate copolymer such as vinyl acetate copolymer, hydroxy-modified vinyl chloride-vinyl acetate copolymer, carboxyl-modified vinyl chloride-vinyl acetate copolymer, vinyl chloride-vinyl acetate-maleic anhydride copolymer Insulating resin such as polymer, styrene-butadiene copolymer, vinylidene chloride-acrylonitrile copolymer, styrene-alkyd resin, silicon-alkyd resin, phenol-formaldehyde resin, poly-N-vinylcarbazole, polyvinylanthracene, polyvinylperylene Organic photoconductive polymers such as Any one of these binder resins may be used alone, or two or more thereof may be mixed and used in any combination.

Specifically, the charge generation layer is prepared by dispersing the charge generation material in a solution obtained by dissolving the above-described binder resin in an organic solvent to prepare a coating solution, and then applying this on the conductive support (when an undercoat layer is provided). Is formed by coating (on the undercoat layer).
The solvent used for preparing the coating solution is not particularly limited as long as it dissolves the binder resin. For example, saturated aliphatic solvents such as pentane, hexane, octane, and nonane, and aromatics such as toluene, xylene, and anisole. Group solvents, halogenated aromatic solvents such as chlorobenzene, dichlorobenzene, chloronaphthalene, amide solvents such as dimethylformamide, N-methyl-2-pyrrolidone, methanol, ethanol, isopropanol, n-butanol, benzyl alcohol, etc. Alcohol solvents, aliphatic polyhydric alcohols such as glycerin and polyethylene glycol, chain or cyclic ketone solvents such as acetone, cyclohexanone, methyl ethyl ketone, 4-methoxy-4-methyl-2-pentanone, methyl formate, ethyl acetate, Acetic acid n-bu Chains such as ester solvents such as benzene, halogenated hydrocarbon solvents such as methylene chloride, chloroform, 1,2-dichloroethane, diethyl ether, dimethoxyethane, tetrahydrofuran, 1,4-dioxane, methyl cellosolve, ethyl cellosolve, etc. Or cyclic ether solvents, acetonitrile, dimethyl sulfoxide, sulfolane, aprotic polar solvents such as hexamethylphosphoric triamide, n-butylamine, isopropanolamine, diethylamine, triethanolamine, ethylenediamine, triethylenediamine, triethylamine-containing nitrogen Compound, mineral oil such as ligroin, water and the like. Any one of these may be used alone, or two or more of these may be used in combination. In addition, when providing the above-mentioned undercoat layer, what does not melt | dissolve this undercoat layer is preferable.

  In the charge generation layer, the compounding ratio (mass ratio) of the binder resin and the charge generation material is usually 10 parts by mass or more, preferably 30 parts by mass or more, and usually 1000 parts by mass with respect to 100 parts by mass of the binder resin. The range is not more than part by mass, preferably not more than 500 parts by mass. The film thickness of the electrification generation layer is usually in the range of 0.1 μm or more, preferably 0.15 μm or more, and usually 10 μm or less, preferably 0.6 μm or less. If the ratio of the charge generation material is too high, the stability of the coating solution may be reduced due to aggregation of the charge generation material. On the other hand, if the ratio of the charge generating material is too low, the sensitivity of the photoreceptor may be lowered.

As a method for dispersing the charge generation material, a known dispersion method such as a ball mill dispersion method, an attritor dispersion method, or a sand mill dispersion method can be used. At this time, it is effective to refine the particles to a particle size in the range of 0.5 μm or less, preferably 0.3 μm or less, more preferably 0.15 μm or less.
-Charge transport layer The charge transport layer of the multilayer photoreceptor contains a charge transport material and usually contains a binder resin and other components used as necessary. Specifically, such a charge transport layer is prepared by dissolving or dispersing a charge transport material or the like and a binder resin in a solvent to prepare a coating solution. In addition, in the case of a reverse lamination type photosensitive layer, it can be obtained by coating and drying on a conductive support (on the undercoat layer when an undercoat layer is provided).

  As the charge transport material, a known carbazole derivative, hydrazone compound, aromatic amine derivative, enamine derivative, butadiene derivative, and a material in which a plurality of these derivatives are bonded are preferable. More specifically, it is described in JP-A-2-230255, JP-A-63-225660, JP-A-58-198043, JP-B-58-32372, and JP-B-7-21646. Compounds are preferably used. Any one of these charge transport materials may be used alone, or a plurality of types may be used in any combination.

The thickness of the charge transport layer is not particularly limited, but is usually 5 μm or more, preferably 10 μm or more, and usually 50 μm or less, preferably 45 μm or less, from the viewpoint of long life, image stability, and high resolution. Is in the range of 30 μm or less.
<Single layer type photosensitive layer>
In addition to the charge generation material and the charge transport material, the single-layer type photosensitive layer is formed using a binder resin in order to ensure film strength, as with the charge transport layer of the multilayer photoreceptor. Specifically, a charge generation material, a charge transport material, and various binder resins are dissolved or dispersed in a solvent to prepare a coating solution, and on a conductive support (or an undercoat layer when an undercoat layer is provided). It can be obtained by coating and drying.

The types of the charge transport material and the binder resin and the usage ratios thereof are the same as those described for the charge transport layer of the multilayer photoreceptor. A charge generating material is further dispersed in a charge transport medium comprising these charge transport material and binder resin.
As the charge generation material, the same materials as those described for the charge generation layer of the multilayer photoreceptor can be used. However, in the case of a photosensitive layer of a single layer type photoreceptor, it is necessary to sufficiently reduce the particle size of the charge generating material. Specifically, the range is usually 1 μm or less, preferably 0.5 μm or less.

If the amount of the charge generating material dispersed in the single-layer type photosensitive layer is too small, sufficient sensitivity cannot be obtained, but if it is too large, there are adverse effects such as a decrease in chargeability and a decrease in sensitivity. The total amount of the layer-type photosensitive layer is usually 0.5% by mass or more, preferably 1% by mass or more, and usually 50% by mass or less, preferably 20% by mass or less.
Further, the use ratio of the binder resin and the charge generating material in the single-layer type photosensitive layer is such that the charge generating material is usually 0.1 parts by mass or more, preferably 1 part by mass or more, and usually 100 parts by mass of the binder resin It is 30 mass parts or less, Preferably it is set as the range of 10 mass parts or less.

The film thickness of the single-layer type photosensitive layer is usually 5 μm or more, preferably 10 μm or more, and usually 100 μm or less, preferably 50 μm or less.
<Other functional layers>
For the purpose of improving film-forming properties, flexibility, coating properties, stain resistance, gas resistance, light resistance, etc., in both the photosensitive layer and each layer constituting it, both in the multilayer type photosensitive member and the single layer type photosensitive member. Additives such as well-known antioxidants, plasticizers, ultraviolet absorbers, electron-withdrawing compounds, leveling agents, and visible light shielding agents may be included. An overcoat layer may be provided on the outermost surface of the photoreceptor.

  Further, in both the laminated type photoreceptor and the single layer type photoreceptor, the photosensitive layer formed by the above procedure may be the uppermost layer, that is, the surface layer, but another layer may be provided on the photosensitive layer and used as the surface layer. Good. For example, a protective layer may be provided for the purpose of preventing the photosensitive layer from being worn out or preventing or reducing the deterioration of the photosensitive layer due to discharge products generated from a charger or the like. The protective layer can be formed by including the charge transport material used for the charge transport layer or other conductive material in the binder resin of the present application. As a conductive material used for the protective layer, metal oxides such as antimony oxide, indium oxide, tin oxide, titanium oxide, tin oxide-antimony oxide, aluminum oxide, and zinc oxide can be used. It is not limited. When the outermost layer is a protective layer, a polyester resin is used in the protective layer.

<Mechanical properties of outermost layer>
Outermost layer, from the viewpoint of preventing external additives due to scratches or sticking of toner (filming), the universal hardness is usually at 180 N / mm ² or more, preferably 195 N / mm ² or more, more preferably 200N / Mm ² or more, more preferably 210 N / mm ² or more. From the viewpoint of preventing poor cleaning, scratches, and filming, the elastic deformation rate is usually 35% or more, preferably 38% or more, more preferably 40% or more, and still more preferably 43% or more.

For a toner having a hard core and a hard shell (before fixing) as used in the present application, the outermost surface of the photoreceptor has high hardness and is easily elastically deformed (not easily plastically deformed). It is preferable that both of the above conditions be satisfied, and that the surface of the photoreceptor is microscopically uniform and that there is no grain boundary that causes breakage. Therefore, when the surface hardness is increased by adding an inorganic filler, there is a possibility that the microscopic uniformity is insufficient and brittle fracture is caused, or the inorganic filler wears the cleaning blade. In addition, in the case where the surface is made of a curable resin, there is a problem that the discharge product and the surface oxidation-modified product are not cleaned and removed because the curable resin is not easily worn. Is difficult to use. In addition, since the curing reaction such as crosslinking does not proceed 100% in the curable resin, there is always an unreacted residue, so that part is another component in the outermost layer or other member such as a cleaning blade. Chemical reactions with components can lead to image defects. Therefore, by including the polyester resin of the electrophotographic photosensitive member in the outermost layer, it has a thermoplastic and uniform surface composition, that is, high compatibility with other components such as additives such as charge transport materials and antioxidants. In addition, an electrophotographic photosensitive member having an outermost layer having both a high surface hardness and a high elastic deformation rate is obtained, so that a toner having a hard core and a hard shell having crystallinity (before fixing) as used in the present application can be obtained. On the other hand, it is preferably used.

<Method for forming each layer>
Each layer constituting the above-described photoreceptor is formed by dip coating, spray coating, nozzle coating, bar coating, roll coating, blade coating on a conductive support obtained by dissolving or dispersing a substance to be contained in a solvent. It is formed by repeating a coating / drying step sequentially for each layer by a known method such as coating.

  There are no particular restrictions on the solvent or dispersion medium used for the preparation of the coating solution, but specific examples include alcohols such as methanol, ethanol, propanol and 2-methoxyethanol, tetrahydrofuran, 1,4-dioxane, dimethoxyethane and the like. Ethers, esters such as methyl formate and ethyl acetate, acetone, methyl ethyl ketone, cyclohexanone, ketones such as 4-methoxy-4-methyl-2-pentanone, aromatic hydrocarbons such as benzene, toluene, xylene, dichloromethane, Chlorinated hydrocarbons such as chloroform, 1,2-dichloroethane, 1,1,2-trichloroethane, 1,1,1-trichloroethane, tetrachloroethane, 1,2-dichloropropane, trichloroethylene, n-butylamine, isopropanolamine, Diethyl Min, triethanolamine, ethylenediamine, nitrogen-containing compounds such as triethylenediamine, acetonitrile, N- methylpyrrolidone, N, N- dimethylformamide, aprotic polar solvents such as dimethyl sulfoxide and the like. Moreover, these may be used individually by 1 type and may use 2 or more types together by arbitrary combinations and kinds.

The amount of the solvent or the dispersion medium used is not particularly limited, but considering the purpose of each layer and the properties of the selected solvent / dispersion medium, it is appropriately determined so that the physical properties such as the solid content concentration and viscosity of the coating liquid are within a desired range. It is preferable to adjust.
For example, in the case of a charge transport layer of a single layer type photoreceptor or a function separation type photoreceptor, the solid content concentration of the coating solution is usually 5% by mass or more, preferably 10% by mass or more, and usually 40% by mass or less. The range is preferably 35% by mass or less. In addition, the viscosity of the coating solution is usually 10 mPa · s or higher, preferably 50 mPa · s or higher, and usually 500 mPa · s or lower, preferably 400 mPa · s or lower, at the temperature during use.

  In the case of a charge generation layer of a multilayer photoreceptor, the solid content concentration of the coating solution is usually 0.1% by mass or more, preferably 1% by mass or more, and usually 15% by mass or less, preferably 10% by mass. % Or less. In addition, the viscosity of the coating solution is usually 0.01 mPa · s or higher, preferably 0.1 mPa · s or higher, and usually 20 mPa · s or lower, preferably 10 mPa · s or lower, at the temperature during use.

Examples of the coating method include a dip coating method, a spray coating method, a spinner coating method, a bead coating method, a wire bar coating method, a blade coating method, a roller coating method, an air knife coating method, and a curtain coating method. Other known coating methods can also be used.
The coating solution is preferably dried by touching at room temperature, followed by heating or drying in a temperature range of usually 30 ° C. or more and 200 ° C. or less for 1 minute to 2 hours, while still or blowing. Further, the heating temperature may be constant, or heating may be performed while changing the temperature during drying.

<Image forming apparatus>
Next, an embodiment of an image forming apparatus having the toner and the electrophotographic photosensitive member used in the present invention (an image forming apparatus of the present invention) will be described with reference to FIG. However, the embodiment is not limited to the following description, and can be arbitrarily modified without departing from the gist of the present invention.

As shown in FIG. 1, the image forming apparatus includes an electrophotographic photosensitive member 1, a charging device 2, an exposure device 3, and a developing device 4, and further, a transfer device 5, a cleaning device 6, and a fixing device as necessary. A device 7 is provided.
The electrophotographic photoreceptor 1 is not particularly limited as long as it is the above-described electrophotographic photoreceptor of the present invention, but in FIG. 1, as an example, a drum in which the above-described photosensitive layer is formed on the surface of a cylindrical conductive support. The photoconductor is shown. A charging device 2, an exposure device 3, a developing device 4, a transfer device 5, and a cleaning device 6 are arranged along the outer peripheral surface of the electrophotographic photoreceptor 1.

  The charging device 2 charges the electrophotographic photosensitive member 1 and uniformly charges the surface of the electrophotographic photosensitive member 1 to a predetermined potential. As the charging device, a corona charging device such as a corotron or a scorotron, a direct charging device (contact type charging device) for charging a direct charging member to which a voltage is applied by contacting the photosensitive member surface, and the like are often used. Examples of the direct charging device include a charging roller and a charging brush. In FIG. 1, a roller-type charging device (charging roller) is shown as an example of the charging device 2. As the direct charging means, either charging with air discharge or injection charging without air discharge is possible. Moreover, as a voltage applied at the time of charging, it is possible to use only a direct current voltage or to superimpose an alternating current on a direct current.

  The type of the exposure apparatus 3 is not particularly limited as long as it can expose the electrophotographic photoreceptor 1 to form an electrostatic latent image on the photosensitive surface of the electrophotographic photoreceptor 1. Specific examples include halogen lamps, fluorescent lamps, lasers such as semiconductor lasers and He—Ne lasers, LEDs, and the like. Further, exposure may be performed by a photoreceptor internal exposure method. The light used for the exposure is arbitrary. For example, if exposure is performed with monochromatic light with a wavelength of 780 nm, monochromatic light with a wavelength of 600 nm to 700 nm, slightly shorter wavelength, monochromatic light with a wavelength of 380 nm to 500 nm, or the like. Good.

  The type of the developing device 4 is not particularly limited, and an arbitrary device such as a dry development method such as cascade development, one-component insulating toner development, one-component conductive toner development, or two-component magnetic brush development, or a wet development method is used. be able to. In FIG. 1, the developing device 4 includes a developing tank 41, an agitator 42, a supply roller 43, a developing roller 44, and a regulating member 45, and has a configuration in which toner T is stored inside the developing tank 41. . Further, a replenishing device (not shown) for replenishing the toner T may be attached to the developing device 4 as necessary. This replenishing device is configured to be able to replenish toner T from a container such as a bottle or a cartridge.

The supply roller 43 is formed from a conductive sponge or the like. The developing roller 44 is made of a metal roll such as iron, stainless steel, aluminum, or nickel, or a resin roll obtained by coating such a metal roll with a silicon resin, a urethane resin, a fluorine resin, or the like. The surface of the developing roller 44 may be smoothed or roughened as necessary.
The developing roller 44 is disposed between the electrophotographic photoreceptor 1 and the supply roller 43 and is in contact with the electrophotographic photoreceptor 1 and the supply roller 43, respectively. The supply roller 43 and the developing roller 44 are rotated by a rotation drive mechanism (not shown). The supply roller 43 carries the stored toner T and supplies it to the developing roller 44. The developing roller 44 carries the toner T supplied by the supply roller 43 and contacts the surface of the electrophotographic photosensitive member 1.

  The regulating member 45 is formed of a resin blade such as silicon resin or urethane resin, a metal blade such as stainless steel, aluminum, copper, brass, phosphor bronze, or a blade obtained by coating such a metal blade with a resin. The regulating member 45 contacts the developing roller 44 and is pressed against the developing roller 44 side with a predetermined force by a spring or the like (a general blade linear pressure is 5 to 500 g / cm). If necessary, the regulating member 45 may be provided with a function of imparting charging to the toner T by frictional charging with the toner T.

The agitator 42 is rotated by a rotation driving mechanism, and agitates the toner T and conveys the toner T to the supply roller 43 side. A plurality of agitators 42 may be provided with different blade shapes and sizes.
The type of the transfer device 5 is not particularly limited, and an apparatus using an arbitrary system such as an electrostatic transfer method such as corona transfer, roller transfer, or belt transfer, a pressure transfer method, or an adhesive transfer method can be used. . Here, it is assumed that the transfer device 5 includes a transfer charger, a transfer roller, a transfer belt, and the like disposed so as to face the electrophotographic photoreceptor 1. The transfer device 5 applies a predetermined voltage value (transfer voltage) having a polarity opposite to the charging potential of the toner T, and transfers the toner image formed on the electrophotographic photosensitive member 1 to a recording paper (paper, medium) P. Is.

  There is no restriction | limiting in particular about the cleaning apparatus 6, Arbitrary cleaning apparatuses, such as a brush cleaner, a magnetic brush cleaner, an electrostatic brush cleaner, a magnetic roller cleaner, a blade cleaner, can be used. The cleaning device 6 is for scraping off residual toner adhering to the photoreceptor 1 with a cleaning member and collecting the residual toner. However, when there is little or almost no toner remaining on the surface of the photoreceptor, the cleaning device 6 may be omitted.

  The fixing device 7 includes an upper fixing member (fixing roller) 71 and a lower fixing member (fixing roller) 72, and a heating device 73 is provided inside the fixing member 71 or 72. FIG. 1 shows an example in which a heating device 73 is provided inside the upper fixing member 71. The upper and lower fixing members 71 and 72 are known heat fixings such as a fixing roll in which a metal base tube such as stainless steel or aluminum is coated with silicon rubber, a fixing roll in which Teflon (registered trademark) resin is coated, or a fixing sheet. A member can be used. Further, each of the fixing members 71 and 72 may be configured to supply a release agent such as silicon oil in order to improve releasability, or may be configured to forcibly apply pressure to each other by a spring or the like.

When the toner transferred onto the recording paper P passes between the upper fixing member 71 and the lower fixing member 72 heated to a predetermined temperature, the toner is heated to a molten state and cooled after passing through the recording paper. Toner is fixed on P.
The type of the fixing device is not particularly limited, and a fixing device of an arbitrary method such as heat roller fixing, flash fixing, oven fixing, pressure fixing, or the like can be provided.

In the electrophotographic apparatus configured as described above, an image is recorded as follows. That is, first, the surface (photosensitive surface) of the photoreceptor 1 is charged to a predetermined potential (for example, −600 V) by the charging device 2. At this time, charging may be performed by a DC voltage, or charging may be performed by superimposing an AC voltage on the DC voltage.
Subsequently, the photosensitive surface of the charged photoreceptor 1 is exposed by the exposure device 3 according to the image to be recorded, and an electrostatic latent image is formed on the photosensitive surface. The developing device 4 develops the electrostatic latent image formed on the photosensitive surface of the photoreceptor 1.

The developing device 4 thins the toner T supplied by the supply roller 43 with a regulating member (developing blade) 45 and has a predetermined polarity (here, the same polarity as the charging potential of the photosensitive member 1) and the negative polarity. ), And conveyed while being carried on the developing roller 44 to be brought into contact with the surface of the photoreceptor 1.
When the charged toner T carried on the developing roller 44 comes into contact with the surface of the photoreceptor 1, a toner image corresponding to the electrostatic latent image is formed on the photosensitive surface of the photoreceptor 1. This toner image is transferred onto the recording paper P by the transfer device 5. Thereafter, the toner remaining on the photosensitive surface of the photoreceptor 1 without being transferred is removed by the cleaning device 6.

After the transfer of the toner image onto the recording paper P, the final image is obtained by passing the fixing device 7 and thermally fixing the toner image onto the recording paper P.
In addition to the above-described configuration, the image forming apparatus may be configured to perform, for example, a static elimination process. The neutralization step is a step of neutralizing the electrophotographic photosensitive member by exposing the electrophotographic photosensitive member, and a fluorescent lamp, an LED, or the like is used as the neutralizing device. In addition, the light used in the static elimination process is often light having an exposure energy that is at least three times that of the exposure light.

The image forming apparatus may be further modified. For example, the image forming apparatus may be configured to perform a pre-exposure process, an auxiliary charging process, or the like, or may be configured to perform offset printing. A full-color tandem system configuration using toner may be used.
The electrophotographic photosensitive member 1 is combined with one or more of the charging device 2, the exposure device 3, the developing device 4, the transfer device 5, the cleaning device 6, and the fixing device 7 to form an integrated cartridge ( The electrophotographic photosensitive member cartridge may be configured to be detachable from a main body of an electrophotographic apparatus such as a copying machine or a laser beam printer. In this case, for example, when the electrophotographic photosensitive member 1 and other members are deteriorated, the electrophotographic photosensitive member cartridge is removed from the main body of the image forming apparatus, and another new electrophotographic photosensitive member cartridge is mounted on the main body of the image forming apparatus. This facilitates maintenance and management of the image forming apparatus.

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples unless it exceeds the gist. In the following examples, “part” means “part by mass”. The actual image test was conducted by mounting the toner of the present invention and a photoreceptor on a tandem full color printer LaserJet 4650 manufactured by Hewlett-Packard.
Each particle diameter, circularity, electrical conductivity, thermal characteristics, etc. were measured as follows.

<Volume average diameter measurement (MV)>
The volume average diameter (MV) of particles with a volume average diameter (MV) of less than 1 micron is from Nikkiso Co., Ltd. Model Microtrac Nanotrac150 (hereinafter abbreviated as Nanotrack) and analysis software Microtrac Particle Analyzer Ver10.1.2-019EE The method described in the instruction manual using the ion-exchanged water having an electric conductivity of 0.5 μS / cm as the solvent, the solvent refractive index: 1.333, the measuring time: 600 seconds, and the number of times of measurement: once. Measured with Other setting conditions were particle refractive index: 1.59, transparency: transmission, shape: true sphere, density: 1.04.

<Volume median diameter measurement (Dv50)>
The volume median diameter (Dv50) of particles with a volume median diameter (Dv50) of 1 micron or more is measured using the Beckman Coulter Multisizer III (aperture diameter 100 μm: hereinafter abbreviated as Multisizer). Using II as a dispersion medium, the dispersion was dispersed so that the dispersoid concentration was 0.03%.

<Average circularity>
The “average circularity” in the present invention is measured as follows and is defined as follows. That is, the toner base particles are dispersed in a dispersion medium (Isoton II, manufactured by Beckman Coulter, Inc.) in a range of 5720 to 7140 particles / μL, and a flow type particle image analyzer (manufactured by Sysmex Corporation, FPIA3000) is used. Measured under the following apparatus conditions, the value is defined as “average circularity”. In the present invention, the same measurement is performed three times, and an arithmetic average value of three “average circularity” is adopted as the “average circularity”.
・ Mode: HPF
-HPF analysis amount: 0.35 μL
-Number of HPF detected: 8,000-10,000 The following are measured by the above device and automatically calculated and displayed in the above device, but "roundness" is defined by the following formula The

[Circularity] = [Perimeter of a circle with the same area as the projected particle area] / [Perimeter of projected particle image]
Then, the number of HPF detected is 8,000 to 10,000, and the arithmetic average (arithmetic mean) of the circularity of each particle is displayed on the apparatus as “average circularity”.
<Thermal characteristics>
Main peak of the endothermic curve when the temperature is increased from 30 ° C to 120 ° C at a rate of 10 ° C / min using the Seiko Electronics Co., Ltd. thermal analyzer DSC220CU. Measure the melting point, heat of fusion, half-width of melting peak, and then measure the crystallization temperature and half-width of crystallization peak from the exothermic curve when the temperature was lowered from 120 ° C to 30 ° C at a rate of 10 ° C / min. did.

<Weight average molecular weight (Mw)>
The THF-soluble component of the polymer primary particle dispersion was measured by gel permeation chromatography (GPC) under the following conditions.
Apparatus: GPC apparatus HLC-8020 manufactured by Tosoh Corporation, column: PL-gel Mixed-B 10 μ manufactured by Polymer Laboratories, solvent: THF, sample concentration: 0.1% by mass, calibration curve: standard polystyrene <loss elastic modulus of toner, Storage modulus>
The loss elastic modulus and storage elastic modulus of the toner were measured under the following conditions.

Equipment: ARES manufactured by TA Instruments Japan, Temperature condition: Temperature rising from 30 ° C to 200 ° C at a rate of 4 ° C / min Plate: Parallel plate (diameter 8mm), Frequency: 1Hz, Initial value of measured strain: 0.1%
As a measurement sample, about 0.25 g of toner was molded into a cylindrical sample having a diameter of about 8 mm and a height of about 5 mm using a hot press machine (50 ° C., 10 kg, 5 min).

(I) Toner <Preparation of Emulsion Liquid A1>
100 parts of behenyl acrylate, 25 parts of paraffin wax (Nippon Seiwa Co., Ltd., HNP-9, melting point 82 ° C.), 20%, BR> H sodium decylbenzenesulfonate aqueous solution (Daiichi Kogyo Seiyaku Co., Ltd., Neogen S20D) Hereafter, abbreviated as 20% DBS aqueous solution) 1.1 parts and 359 parts of demineralized water were heated to 90 ° C. and stirred for 10 minutes using a homomixer (Mark IIf model, manufactured by Tokushu Kika Kogyo Co., Ltd.). Next, under heating at 90 ° C., circulation emulsification is started under a pressure of 20 MPa using a high pressure emulsifier, and the particle diameter is measured with Nanotrac and dispersed until the volume average particle diameter (MV) is 500 nm or less. An emulsion A1 was prepared. The final particle size (MV) was 277 nm.

<Preparation of polymer primary particle dispersion C1>
<First step>
A reactor equipped with a stirrer (three blades), a heating / cooling device, a concentrating device, and a raw material / auxiliary charging device, 194.8 parts of emulsion A1 and 197 parts of demineralized water (monomer added in the second step) And the temperature was raised to 90 ° C. under a nitrogen stream while stirring.

Thereafter, 4.16 parts of an 8% aqueous hydrogen peroxide solution and an 8% L-(+) ascorbic acid aqueous solution were added while stirring was continued. G '(Tm + 20) of the freeze-dried latex product obtained in the first step
Was 6.8 × 10 ⁻¹ Pa.
<Second step>
The following monomer / emulsifier mixture was added to the liquid of the first step over 5 hours. Simultaneously with the start of dropping of the mixture of monomers and emulsifier solution, dropping of the following aqueous initiator solution 1 was also started. Thereafter, the aqueous initiator solution 2 was further added over 2 hours. Thereafter, the inner temperature was maintained at 90 ° C. for 1 hour under stirring.
[Monomers]
Styrene 76.3 parts Butyl acrylate 23.7 parts Acrylic acid 1.5 parts Hexanediol diacrylate 1.0 part Trichlorobromomethane 1.0 part [Emulsifier aqueous solution]
20% DBS aqueous solution 1.0 part demineralized water 67.3 parts [initiator aqueous solution 1]
8% aqueous hydrogen peroxide solution 17.2 parts 8% L-(+) ascorbic acid aqueous solution 17.2 parts [initiator aqueous solution 2]
8% L-(+) Ascorbic acid aqueous solution 14.2 parts After the completion of the polymerization reaction, the mixture was cooled to obtain a milky white primary polymer particle dispersion C1. The volume average particle diameter (MV) measured using a nanotrack was 245 nm. The weight average molecular weight (Mw) was 75,000.

<Manufacture of toner mother particles E1>
A mixer equipped with a stirrer (double helical blade), heating / cooling device, concentrating device, and each raw material / auxiliary charging device was charged with 80 parts (solid content) of polymer primary particle dispersion C1 and the internal temperature was set to 26 ° C. Then, 0.05 parts (solid content) of 20% DBS aqueous solution was added and mixed uniformly. Further, a 5% aqueous solution of ferrous sulfate (0.53 parts as FeSO ₄ .7H ₂ O) was added over 5 minutes, and stirring was continued for 5 minutes to mix uniformly. Subsequently, 4.4 parts (solid content) of cyan pigment dispersion (EP750 manufactured by Dainichi Seika Co., Ltd.) was added over 5 minutes and mixed uniformly, and then 100 parts of demineralized water was added dropwise. During this time, the internal temperature was kept at 26 ° C. Thereafter, the temperature was raised to 51 ° C. over 40 minutes, and further raised to 53 ° C. over 30 minutes. Here, the volume median particle size (Dv50) was measured using a multisizer, and it was 4.9 μm. Thereafter, 20 parts (solid content) of the polymer primary particle dispersion C1 was added over 3 minutes and held there for 30 minutes, and then 6 parts of 20% DBS aqueous solution (solid content) was added over 10 minutes. The temperature was raised to 95 ° C. over 60 minutes and held for 30 minutes.

Thereafter, the slurry obtained by cooling to 30 ° C. over 20 minutes was extracted, and suction filtered with an aspirator using 5 types C (No. 5C, manufactured by Toyo Roshi Kaisha, Ltd.). The cake remaining on the filter paper is transferred to a stainless steel container with an internal volume of 10 L equipped with a stirrer (propeller blade), added with 8 kg of ion-exchanged water having an electric conductivity of 1 μS / cm, and uniformly dispersed by stirring at 50 rpm. Thereafter, stirring was continued for 30 minutes.

  After that, using 5 C filter paper again, suction filtration with an aspirator, the solid matter remaining on the filter paper was again equipped with a stirrer (propeller blade), containing 8 kg of ion-exchanged water with an electric conductivity of 1 μS / cm The product was transferred to a stainless steel container having a volume of 10 L and uniformly dispersed by stirring at 50 rpm, and stirring was continued for 30 minutes. When this process was repeated 5 times, the electrical conductivity of the filtrate was 2 μS / cm.

The obtained cake was spread on a stainless steel bat so as to have a height of 20 mm, and dried in a blow dryer set at 40 ° C. for 48 hours to obtain toner mother particles E1.
The volume median particle size (Dv50) of the toner base particles E1 measured using Multisizer III is 5.
The average circularity measured by a flow type particle analyzer was 0.971.
<Manufacture of development toner F1>
Into Kyoritsu Riko Co., Ltd. sample mill KR-3, 100 parts of toner base particles E1 were introduced.
Subsequently, 2.04 parts of colloidal silica having a volume average primary particle diameter of 80 nm and 0.36 parts of large particle diameter silica having a volume average primary particle diameter of 30 nm were added and stirred and mixed for a total of 5 minutes. Thereafter, 0.30 part of titania particles having a volume average primary particle size of 250 nm treated with alumina and 0.76 part of small particle size silica having a volume average primary particle size of 10 nm are added, stirred and mixed for a total of 6 minutes, and sieved. Thus, developing toner F1 was obtained.

The toner F1 had G ′ (50) of 3.11 × 10 ⁹ Pa, G ′ (Tm + 50) of 1.77 × 10 ⁵ Pa, and G ′ (Tm + 100) of 2.92 × 10 ⁴ Pa.
<Blocking resistance>
10 g of developing toner is put into a cylindrical container having an inner diameter of 3 cm and a height of 6 cm, a load of 20 g is put on it, left in an environment of 50 ° C. and 40% RH for 24 hours, and then the toner is taken out of the container and loaded from above. The degree of aggregation was confirmed by applying.
A (good): It collapses with a load of less than 50 g.
○ (Practical use possible): Although aggregated, it collapses under a load of less than 500 g.
Δ (insufficient): Agglomerated and collapses under a load of 500 g or more and less than 1500 g.
X (Unusable): Aggregates and does not collapse unless a load of 1500 g or more is applied.

(II) Photoconductor <Manufacture of photoconductor P1>
The following undercoat layer dispersion is dip-coated on an aluminum (3003) tube having a diameter of 30 mm and a length of 260.5 mm so that the film thickness after drying is 1.25 μm, dried and undercoated. A layer was formed.

The undercoat layer dispersion was prepared by the following method. That is, a rutile type titanium oxide having an average primary particle size of 40 nm (“TTO55N” manufactured by Ishihara Sangyo Co., Ltd.) and 3% by mass of methyldimethoxysilane (“TSL8117” manufactured by Toshiba Silicone Co., Ltd.) with respect to the titanium oxide were flowed at high speed. Disperse the surface-treated titanium oxide obtained by mixing at high speed with a rotary mixing speed of 34.5 m / sec using a ball mill of methanol / 1-propanol. Thus, a dispersion slurry of hydrophobized titanium oxide was obtained. The dispersion slurry, a mixed solvent of methanol / 1-propanol / toluene, and ε-caprolactam [compound represented by the following formula (F)] / bis (4-amino-3-methylcyclohexyl) methane [the following formula ( G)] / hexamethylenediamine [compound represented by the following formula (H)] / decamethylene dicarboxylic acid [compound represented by the following formula (I)] / octadecamethylene dicarboxylic acid [following formula The compound molar ratio of the compound represented by (J) is 60%
/ 15% / 5% / 15% / 5% of the copolymerized polyamide pellets are heated and stirred and mixed to dissolve the polyamide pellets, and then subjected to ultrasonic dispersion treatment to obtain methanol / 1- An undercoat layer dispersion having a solid content concentration of 18.0% and containing a propanol / toluene mass ratio of 7/1/2 and a hydrophobically-treated titanium oxide / copolymerized polyamide at a mass ratio of 3/1.

  Next, 10 parts of oxytitanium phthalocyanine having a powder X-ray diffraction spectrum shown in FIG. In addition to 150 parts of 2-dimethoxyethane, a pigment dispersion A was prepared by pulverizing and dispersing with a sand grind mill. Next, 10 parts of β-type (A-type) oxytitanium phthalocyanine was added to 150 parts of 1,2-dimethoxyethane, and pulverized and dispersed in a sand grind mill to prepare pigment dispersion B. 128 parts of pigment dispersion A thus obtained, 32 parts of pigment dispersion B, and 5% 1,2-dimethoxyethane solution of polyvinyl butyral (trade name # 6000C, manufactured by Denki Kagaku Kogyo Co., Ltd.) 100 And a suitable amount of 1,2-dimethoxyethane were mixed to finally prepare a dispersion for a charge generation layer having a solid content concentration of 4.0%.

This charge generation layer dispersion was dip-coated on the above undercoat layer so that the film thickness after drying was 0.3 μm, and then dried to form a charge generation layer.
Next, 80 parts of a mixture (molar ratio 2: 1) of the following charge transport materials CT-1a and CT-1b, 100 parts of polyester resin PE-1 (viscosity average molecular weight is 43,000) comprising the following structural units: As an antioxidant, 8 parts by weight of IRGANOX 1076, manufactured by Ciba Specialty Chemicals, and 0.1 part of silicone oil as a leveling agent, 640 parts of a mixed solvent of tetrahydrofuran and toluene (80% by weight of tetrahydrofuran, 20% by weight of toluene) And a coating solution for forming a charge transport layer was prepared. This solution is applied onto the above-described charge generation layer using an applicator so that the film thickness after drying is 25 μm, and dried at 125 ° C. for 20 minutes to form a charge transport layer, thereby producing a photoreceptor P1. did.

<Measurement of surface hardness of photoreceptor>
The universal hardness of the surface of the photoreceptor was measured using FischerSCOPE H100C manufactured by Fischer in an environment of a temperature of 25 ° C. and a relative humidity of 50%. The universal hardness value is a value obtained when the indentation is pushed down to an indentation load of 5 mN, and is a value defined by the following formula from the indentation depth at that time. In the measurement in this region, the influence of the hardness of the substrate (aluminum tube) can be eliminated.

Universal hardness (N / mm ² ) = Test load (N) / Vickers indenter surface area under test load (mm ² )
<Measurement of elastic deformation rate of photoconductor>
The elastic deformation rate of the photoreceptor was measured using FischerSCOPE H100C manufactured by Fischer in an environment of a temperature of 25 ° C. and a relative humidity of 50%. For the measurement, a Vickers square pyramid diamond indenter having a facing angle of 136 ° is used. The measurement conditions are set as follows, the load applied to the indenter and the indentation depth under the load are continuously read, and profiles as shown in FIG. 3 plotted on the Y axis and the X axis are obtained.
・ Measurement conditions Maximum indentation load 5mN
Load required time 10 seconds Unloading required time 10 seconds The above elastic deformation rate is a value defined by the following formula, and the work performed by the film due to elasticity at the time of unloading with respect to the total work required for indentation. It is a ratio.

Elastic deformation rate (%) = (We / Wt) × 100
In the above formula, the total work Wt (nJ) indicates the area surrounded by A-B-D-A in FIG. 4, and the elastic deformation work We (nJ) is the area surrounded by C-B-D-C. Indicates. As the elastic deformation rate is larger, the deformation with respect to the load is less likely to remain, and when the elastic deformation rate is 100, it means that no deformation remains.

(III) Image test
The obtained toner and photoreceptor are mounted on a tandem full-color printer LaserJet 4650 manufactured by Hewlett-Packard, and 8000 sheets are continuously printed at a printing rate of 5% at an ambient temperature of 23 ° C. and a relative humidity of 50%. Background), presence / absence of cleaning failure, remaining amount of toner (PC fog) on the photoreceptor after transfer / before cleaning, occurrence of toner adhesion (filming) on the photoreceptor were examined.

<Measurement method of fog>
Using an image forming apparatus, the color difference of the white background of each standard paper (OKI Excellent White) before printing and after continuous printing was measured with X-Rite 938 (manufactured by X-Rite), and the magnitude of ΔE Thus, the following criteria were used.
○ (Good): △ E <0.8
Δ (slightly generated): 0.8 ≦ ΔE <1.2
X (Generation): 1.2 ≦ ΔE
<Cleaning evaluation of photoconductor>
The degree of occurrence of stripe unevenness due to poor toner cleaning on the white background of the photoreceptor was evaluated.
○ (No cleaning occurs)
△ (partial occurrence)
× (Overall occurrence)
<PC fogging measurement method>
A tape was affixed and peeled off between the transfer / cleaning blades of the photoreceptor in the image forming apparatus, and the residual toner was sampled. The tape was affixed to a standard paper (OKI Excellent White), the influence of the tape portion was subtracted, and the color difference was measured with X-Rite 938 (manufactured by X-Rite).
○ (Good): ΔE <1.2
Δ (decent): 1.2 ≦ ΔE <1.5
× (defect): 1.5 ≦ ΔE
<Evaluation of photoconductor filming>
After continuous printing, the photosensitive member was taken out from the cartridge, and air was strongly applied to blow out the residual toner sufficiently. Then, the toner component remaining on the photosensitive member (strongly fixed component), that is, the degree of filming component was evaluated.
○ (No filming)
△ (partial occurrence)
× (Overall occurrence)
Table 1 shows the toner, photoconductor and image test results.

The toner was produced by the following method, and the same P1 as in Example 1 was used as the photoreceptor, and evaluation was performed in the same manner as in Example 1. The results are shown in Table-1.
<Preparation of emulsion A2>
An emulsion A2 was prepared in the same manner as A1, except that the composition was 100 parts behenyl acrylate, 100 parts stearyl acrylate, 2.2 parts 20% DBS aqueous solution, and 798 parts demineralized water. The final particle size (MV) was 360 nm.

<Preparation of emulsion A3>
The composition is 100 parts paraffin wax (Nippon Seiwa Co., Ltd., HNP-9, melting point 82 ° C.), 6.91 parts stearyl acrylate, 3.3 parts decaglycerin decabehenate (acid value 3.2, hydroxyl value 27). An emulsion A3 was prepared in the same manner as A1, except that 1.415 parts of 20% DBS aqueous solution and 255.9 parts of demineralized water were used. The final particle size (MV) was 225 nm.

<Preparation of polymer primary particle dispersion C2>
Polymer primary particle dispersion C2 was obtained in the same manner as C1, except that 181.6 parts of emulsion A2 and 41.8 parts of emulsion A3 were used instead of emulsion A1, and the amount of water was 199 parts. . The volume average particle diameter (MV) is 230 nm, and the weight average molecular weight (Mw) is 57,000. G ′ (Tm + 20) of the lyophilized latex obtained in the first step is 9.2 × 10 ⁻¹ P
a.

<Manufacture of toner mother particles E2>
Toner base particle E2 is produced in the same manner as E1, except that C2 is used instead of polymer primary particle dispersion C1 and the temperature is raised to 52 ° C. over 40 minutes and further raised to 55 ° C. over 60 minutes. Got. The volume median particle size (Dv50) was 5.4 μm, and the average circularity measured by a flow particle analyzer was 0.972.

<Manufacture of developing toner F2>
A developing toner F2 was obtained in the same manner as F1, except that E2 was used instead of the toner base particles E1.
The toner F2 had G ′ (50) of 2.16 × 10 ⁹ Pa, G ′ (Tm + 50) of 2.27 × 10 ⁵ Pa, and G ′ (Tm + 100) of 2.87 × 10 ⁴ Pa.

  Except for using PE-2 (viscosity average molecular weight of 40,000, isophthalic acid: terephthalic acid = 50: 50) instead of PE-1 as the binder resin of the charge transport layer of the photoreceptor P1 in Example 1. Were produced and evaluated in the same manner as in Example 1. The results are shown in Table-1.

[Comparative Example 1]
<Preparation of polymer primary particle dispersion C3>
A polymer primary particle dispersion C3 was obtained in the same manner as in C1, except that the 8% aqueous hydrogen peroxide solution and the 8% L-(+) ascorbic acid aqueous solution in the first step were not added. The volume average particle size (MV) was 234 nm and the weight average molecular weight (Mw) was 40,000.

<Manufacture of toner mother particles E3>
Toner base particles E3 were produced in the same manner as E1 except that C3 was used in place of the polymer primary particle dispersion C1, but they aggregated during drying and were not at a level that could be used as toner base particles.
[Comparative Example 2]
<Preparation of polymer primary particle dispersion C4>
A reactor equipped with a stirrer (three blades), a heating / cooling device, a concentrating device, and a raw material / auxiliary charging device was charged with 100 parts of emulsion A1, and the temperature was raised to 90 ° C. under a nitrogen stream while stirring . Thereafter, 4.16 parts of an 8% aqueous hydrogen peroxide solution and an 8% L-(+) ascorbic acid aqueous solution were added while stirring was continued to obtain a polymer primary particle dispersion C4.

<Preparation of polymer primary particle dispersion C5>
The emulsion A3 was used in place of the emulsion A1, and the mixture of monomers and emulsifier solution was added over 5 hours without adding the 8% aqueous hydrogen peroxide solution and the 8% L-(+) ascorbic acid aqueous solution. In the same manner as in C1, a polymer primary particle dispersion C5 was obtained. Volume average particle size (MV)
Was 210 nm, and the weight average molecular weight (Mw) was 55,000.

<Manufacture of toner mother particle E4>
Toner mother particles E4 were obtained in the same manner as in E1, except that a mixed liquid of C4 and C5 was used instead of the polymer primary particle dispersion C1. The volume median particle size (Dv50) was 7.2 μm, and the average circularity measured by a flow particle analyzer was 0.924.
<Manufacture of development toner F4>
A developing toner F4 was produced in the same manner as F1 except that E4 was used in place of the toner base particles E1, but the silica fine particles were repelled by the toner base particles and were not at a level usable as a developing toner. .

[Comparative Example 3]
The photoconductor as in Example 1 except that the following PC-1 (viscosity average molecular weight is 40,000) was used instead of PE-1 as the binder resin in the charge transport layer of the photoconductor P1 in Example 1. CP1 was produced and evaluated. The results are shown in Table-1.

[Comparative Example 4]
The photoconductor in the same manner as in Example 1 except that the binder resin in the charge transport layer of the photoconductor P1 in Example 1 is replaced with PE-1 and the following PC-2 (viscosity average molecular weight is 40,000) is used. CP2 was prepared and evaluated. The results are shown in Table-1.

As shown in Table 1, Examples 1 to 3 were all good results. On the other hand, Comparative Examples 1 and 2 could not be used as toner base particles or developing toner. Further, Comparative Examples 3 and 4 using a polycarbonate resin as the binder resin for the charge transport layer had inadequate results, particularly with respect to PC fogging. There was a significant difference in PC fog, but a large PC fog means that there is a large amount of residual toner, and a cleaning failure when the cleaning blade has deteriorated after continuing the printing durability test. This is a major factor in potential quality defects in the sense that it can lead to charging roller contamination when slipping through. The reason why the polycarbonate resin of the comparative example has a larger PC fog than the polyester resin of the example is that the polyester resin is transferred to a toner having a small particle diameter and excellent low-temperature fixability like the present toner. It is mentioned that it is excellent in the release property in time. The photoreceptors P1 and P2 are advantageous in maintaining transferability at the time of durability of a toner using the crystallinity of a resin having a long-chain alkyl group, which is excellent in low particle size and low-temperature fixability like the present toner. I understand. Further, it can be presumed that the photoconductor CP2 of Comparative Example 4 is inferior in cleaning and filming evaluation, and that the surface hardness and elastic deformation rate of the photoconductor are low. From the above, it can be seen that the combination of the toner and the photoreceptor of the present application expresses good image characteristics.

1 Photoconductor (Electrophotographic photoconductor)
2 Charging device (charging roller; charging unit)
3 Exposure equipment (exposure section)
4 Development device (development unit)
DESCRIPTION OF SYMBOLS 5 Transfer apparatus 6 Cleaning apparatus 7 Fixing apparatus 41 Developing tank 42 Agitator 43 Supply roller 44 Developing roller 45 Control member 71 Upper fixing member (fixing roller)
72 Lower fixing member (fixing roller)
73 Heating device T Toner

Claims (12)

  In an image forming apparatus having an electrostatic charge image developing toner and an electrophotographic photosensitive member, the toner contains at least a binder resin, a colorant, and a wax, and the binder resin polymerizes a long-chain (meth) acrylate ester. The first step is produced through a second step of polymerizing a vinyl monomer in the presence of the polymer obtained in the first step, and the electrophotographic photosensitive member comprises a polyester resin as an outermost surface layer. An image forming apparatus comprising: 2. The image forming apparatus according to claim 1, wherein the polyester resin is represented by the following formula (1).

(In the formula [1], Ar ^{1 to} Ar ⁴ each independently represents an arylene group which may have a substituent, and X represents a single bond, an oxygen atom, a sulfur atom, or the following formula [2]. Or a group represented by the following formula [3], wherein R ¹ and R ² in the formula [2] each independently represent a hydrogen atom, an alkyl group, or an aryl group, and R ¹ and R 2 ² may be bonded to form a ring, and R ³ in the formula [3] is an alkylene group, an arylene group, or a group represented by the following formula [4], which is represented by the formula [4] R ⁴ and R ⁵ therein independently represent an alkylene group, Ar ⁵ represents an arylene group, and k represents an integer of 0 or more.)

In the formula [1], Y is a single bond, an oxygen atom, a sulfur atom, or a group represented by the following formula [5]. In the formula [5], R ⁶ and R ⁷ are each independently hydrogen. It represents an atom, an alkyl group, an alkoxy group, or an aryl group, and R ⁶ and R ⁷ may combine to form a ring.

The X in the formula [1] is an oxygen atom, a sulfur atom, a group represented by the formula [2], or a group represented by the formula [3]. The image forming apparatus described. The image forming apparatus according to claim 1, wherein the polyester resin includes a structure represented by the following formula [6].

  5. The image forming apparatus according to claim 1, wherein a toner containing at least a component having 22 or more carbon atoms is used in the ester portion of the long-chain acrylic acid ester.   6. The image forming apparatus according to claim 1, wherein the long-chain (meth) acrylic ester used in the first step is obtained by high-pressure mechanical emulsification.   The image forming apparatus according to claim 1, wherein a radical polymerization initiator is used at least during the polymerization in the second step.   The long-chain (meth) acrylic acid ester polymer obtained in the first step is contained in the binder resin in an amount of 1% by mass to 50% by mass, according to any one of claims 1 to 7. The image forming apparatus described.   The image forming apparatus according to claim 1, wherein a melting point (Tm) of the toner satisfies Tm ≦ 80 ° C.   The image forming apparatus according to claim 1, wherein the toner has a melting point (Tm) of Tm ≧ 40 ° C. When the storage elastic modulus of the polymer obtained in the first step at 1 Hz at a temperature 20 ° C. higher than the melting point (Tm) of the toner is G ′ (Tm + 20), the following formula (2) is satisfied. The image forming apparatus according to claim 1, wherein the toner is used.
G ′ (Tm + 20) ≦ 1 × 10 ³ [Pa] (2)   12. The image forming apparatus according to claim 1, wherein the toner has an endothermic peak at a temperature rise of 45 ° C. or less in a DSC curve measured by a differential scanning calorimeter.

Images