JP2006091124A - Electrostatic charge image developing toner, electrostatic charge image developing developer and image forming method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrostatic charge image developing toner having excellent low temperature fixing property and offset resistance and preventing blocking, to provide an electrostatic charge image developing developer and an image forming method using the above toner, and further, to provide an image forming method preventing failure in picture quality such as a stripe image drop-off due to filming of inorganic fine particles on an image carrier. <P>SOLUTION: The electrostatic charge image developing toner contains at least a binder resin, wherein the binder resin contains crystalline polyester and an amorphous polymer. The amorphous polymer contains an aliphatic crosslinked component A and an aromatic crosslinked component B, satisfying 0.1≤[B]/[A]≤0.4, wherein [A] is the content of the component A and [B] is the content of the component B. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an electrostatic charge image developing toner and an image forming method that can be used in an image forming apparatus in an electrophotographic apparatus using an electrophotographic process such as a copying machine, a printer, and a facsimile machine.

  Many methods are known as electrophotographic methods (see, for example, Patent Document 1). In general, a latent image (hereinafter also referred to as an “electrostatic latent image” or an “electrostatic latent image”) is electrically formed on the surface of a photosensitive member (latent image holding member) using a photoconductive substance by various means. And the latent image thus formed is developed using an electrostatic charge image developing toner (hereinafter also simply referred to as “toner”) to form a toner image. An image is formed through a plurality of steps of transferring to a surface of a transfer medium such as paper via a transfer body and fixing by heating, pressurization, heat pressurization, solvent vapor, or the like. Further, the toner remaining on the surface of the photoreceptor is cleaned by various methods as necessary, and is used again for developing the toner image.

  As a fixing technique for fixing the toner image transferred to the surface of the transfer target, a hot roll fixing is performed in which the transfer target having the toner image transferred is inserted between a pair of rolls including a heating roll and a pressure roll and fixed. The law is common. As a similar technique, a fixing method in which one or both of the rolls is replaced with a belt is also known. These techniques, compared to other fixing methods, provide high-speed and robust images, high energy efficiency, and less harm to the environment due to volatilization of solvents and the like.

  On the other hand, the toner image transferred to the surface of the transfer medium through the transfer process is melted by being heated by the fixing member heated in the fixing process, and is fixed to the surface of the transfer target. It is known that in the fixing step, the toner image is not fixed unless the fixing member sufficiently heats not only the toner image but also the transfer target. If the transfer medium is not sufficiently heated, only the toner is melted by the heating from the fixing member, and a so-called cold offset is generated in which the toner adheres to the fixing member.

  Further, when the transfer target or the toner image is excessively heated, the viscosity of the toner is reduced, and so-called hot offset occurs in which part or all of the toner image adheres to the fixing member side. Therefore, it is necessary to set the fixing conditions so that both the cold offset and the hot offset do not occur when the fixing member is used to heat the transfer target or the toner image transferred to the surface thereof.

  On the other hand, in order to save power in the fixing process that occupies a certain amount of power consumption as the demand for energy saving required for image formation increases, and in order to expand the fixing conditions, the toner fixing temperature It is necessary to lower the temperature. By lowering the toner fixing temperature, in addition to the power saving and the expansion of the fixing conditions, the waiting time until the fixing temperature on the surface of the fixing member such as a fixing roll at the time of power input, that is, the so-called warm-up time is shortened. The time can be extended and the life of the fixing member can be extended.

  However, when the fixing temperature of the toner is lowered, the glass transition point of the toner particles is lowered at the same time, and it becomes difficult to achieve compatibility with the storage stability of the toner. In order to achieve both low temperature fixing and toner storage stability, it is necessary to have a so-called sharp melt property in which the viscosity of the toner rapidly decreases in a high temperature region while keeping the glass transition point of the toner at a higher temperature. .

  However, since the resin used for the toner usually has a certain range of glass transition point, molecular weight, etc., in order to obtain the sharp melt property, it is necessary to make the resin composition and molecular weight extremely uniform. In order to obtain such a highly uniform resin, it becomes necessary to adjust the molecular weight of the resin by using a special production method or by treating the resin with chromatography or the like. In this case, the cost for producing a highly uniform resin is inevitably high, and unnecessary resin (waste) is produced when producing a highly uniform resin, which is preferable from the viewpoint of environmental protection in recent years. Absent.

  On the other hand, if the copied images are stored over a long period of time, there may be a problem that a part or all of the images are transferred to the back of the upper upper paper (hereinafter referred to as “document offset”). ). This phenomenon is particularly promoted when an image is stored under conditions of high temperature and high humidity, and the image storage stability is deteriorated. Therefore, an image forming method capable of maintaining a clear image under such conditions is desired.

  Therefore, there is a strong demand for an electrophotographic toner that is fixed at a low temperature and does not generate an offset up to a higher temperature region, so-called a wide fixing latitude, and an image forming method capable of obtaining an image that can withstand document offset.

  As a means for preventing the occurrence of offset, a method using a binder resin blended with a high molecular polymer or a crosslinked polymer (for example, see Patent Document 2, Patent Document 3, etc.) is known. By increasing the surface cohesive force, a means for preventing toner fusion to the surface of the fixing member is taken. However, although these methods are effective in preventing offset, there arises a problem that the fixing temperature rises.

  In order to improve the releasability from the surface of the fixing member, attempts have been made to add low molecular weight components such as polypropylene, polyethylene, alkylamide compounds, and ester compounds to the toner. However, although these methods can also improve the effect of offset resistance, blocking or the like is likely to occur due to long-term storage in a developing machine, and there is a concern about storage stability.

  On the other hand, as a means for lowering the toner fixing temperature, a technique of lowering the glass transition point of toner resin (binder resin) is generally performed. However, if the glass transition point is too low, powder aggregation (blocking) is likely to occur, and toner preservability on a fixed image is lost. Therefore, the lower limit of the glass transition point of the toner is practically 60 ° C. Although the glass transition point is a design point of many commercially available toner resins, at present, it has not been possible to obtain a toner that can be fixed at low temperature by the method of lowering the glass transition point. Although the fixing temperature can be lowered by using a plasticizer, there is a problem that toner blocking occurs during storage or in the developing machine.

  A method of using a crystalline resin as a binder resin has been known for a long time in order to achieve both blocking prevention, image storability, and low-temperature fixability (see, for example, Patent Document 4 and Patent Document 5). However, since the crystalline resin is difficult to grind by the kneading and grinding method and the yield is low, there is a problem that the practicality is poor from the viewpoint of manufacturability. Even if practicality in production can be secured, the fixing temperature can be lowered, but sufficient offset resistance cannot always be obtained. That is, although the melted toner penetrates into the paper, it has an effect of preventing the occurrence of offset, but the melted toner soaks into the paper so that a uniform and high density image cannot be obtained. .

  As means for solving the above problems, many techniques for using a crystalline resin and an amorphous resin in combination, instead of using a crystalline resin alone as a binder resin, have been proposed. It is also known that when a toner is produced by a kneading pulverization method, pulverization is facilitated by the presence of an amorphous resin portion. For example, a method using a crystalline resin and an amorphous resin in combination (for example, see Patent Document 6), or a method using a resin in which a crystalline resin and an amorphous resin are chemically bonded (for example, Patent Document). 7-11)).

  However, when the amorphous resin is more than the crystalline resin, the amorphous resin becomes the continuous phase and the crystalline resin becomes the dispersed phase. In this case, the crystalline resin is covered with the amorphous resin. Therefore, while the problem due to the crystalline resin does not occur, the melting of the entire toner is governed by the softening temperature of the amorphous resin, so that it is difficult to achieve low-temperature fixability.

  On the other hand, in the electrophotographic process, the change in the shape of the toner in the transfer process is an important phenomenon that determines the occurrence of image quality failure such as image omission due to adhesion of toner to the photoreceptor. The toner used has a problem that the shape change is more easily caused than the conventionally used amorphous resin, and an image quality failure such as image omission due to adhesion of the toner to the photoconductor occurs. The change in the shape of the toner in the transfer process increases the contact area between the photoconductor and the toner, and the toner tends to adhere to the photoconductor.

In order to suppress the occurrence of offset, supplying a release agent such as silicone oil to the surface of the fixing roll is widely performed. However, it is difficult to make the supply amount of the release agent constant, and there are problems such as offset when the release agent is too small and oil streaks when there is too much release agent. It was.
Therefore, a method for incorporating a release agent into the toner has been proposed.

  On the other hand, a developer for electrostatic charge development (hereinafter, also simply referred to as “developer”) and inorganic fine particles are externally added to the toner for the purpose of improving and maintaining the fluidity, cleaning property, and transferability of the toner. An attempt is being made. (For example, refer to Patent Documents 12 to 16.)

  In the electrophotographic process, when the toner is coated with a surface layer composed mainly of an amorphous polymer, the toner undergoes a shape change in the transfer process, the internal crystalline resin is exposed, and part of the exposed crystalline resin Adheres to the image carrier and externally added to the toner, the inorganic fine particles adhere to the image carrier (so-called filming), causing streak-like image omission.

Japanese Patent Publication No.42-23910 JP 50-134652 A JP-A-51-23354 Japanese Patent Publication No. 56-13943 Japanese Examined Patent Publication No.62-39428 Japanese Patent Laid-Open No. 2-79860 JP-A-1-163756 Japanese Patent Laid-Open No. 1-163757 JP-A-4-81770 JP-A-4-155351 JP-A-5-44032 JP 59-226355 A Japanese Patent Laid-Open No. 61-23160 JP 63-118757 A Japanese Patent Laid-Open No. 2-1870 JP-A-2-90175

  An object of the present invention is to solve the above problems. That is, the present invention has an object to provide a toner for developing an electrostatic charge image that is excellent in low-temperature fixing and offset resistance and achieves anti-blocking, a developer for developing an electrostatic charge image using the same, and an image forming method. And It is another object of the present invention to provide an image forming method that does not cause image quality problems such as streak-like image omission due to filming of inorganic fine particles on an image carrier.

The above-mentioned subject is achieved by the following present invention. That is, the present invention
(1) An electrostatic charge image developing toner containing at least a binder resin, wherein the binder resin contains a crystalline polyester and an amorphous polymer, and the amorphous polymer is an aliphatic cross-linking component A and an aromatic cross-link. When component A is included, the content of A is [A], and the content of B is [B],
0.1 ≦ [B] / [A] ≦ 0.4
An electrostatic charge image developing toner,
(2) A developer for developing an electrostatic image, comprising the toner according to (1) and a carrier,
(3) an electrostatic charge image forming step for forming an electrostatic charge image on the electrostatic charge image carrier, and a development step for developing the electrostatic charge image with an electrostatic charge image developing developer containing toner to form a toner image. An image forming method comprising: a transfer step of transferring the toner image onto a transfer target; and a fixing step of fixing the toner image, wherein the following formula of the toner remaining on the photoconductor after passing through the transfer nip: The toner according to (1) or the developer for developing an electrostatic charge image according to (2), wherein the toner shape change rate (Tt) represented by (1) is 60 to 100%. Image forming method.
Tt = (h / x) × 100 (1)
Here, x represents the maximum length (μm) of the deformed toner particle projected image, and h represents the deformed toner particle projected image formed on a plane perpendicular to the axis in the maximum length direction of the deformed toner particle projected image. Represents the maximum length (μm).

  As described above, according to the present invention, it is possible to provide a toner and a developer for developing an electrostatic image that are excellent in low-temperature fixing and anti-offset properties and achieve anti-blocking, and further, the toner adheres to the photoreceptor. Therefore, it is possible to provide an image forming method that does not cause an image quality failure such as image omission due to the above.

  Hereinafter, the present invention will be described in the order of toner, toner manufacturing method, developer, image forming method, and toner shape change rate measuring method.

<Toner>
The toner of the present invention is an electrostatic charge image developing toner containing at least a binder resin, a colorant and a release agent, and the binder resin contains a crystalline polyester and an amorphous polymer, and the amorphous polymer. Contains an aliphatic crosslinking component A and an aromatic crosslinking component B, the content of A is [A], and the content of B is [B],
0.1 ≦ [B] / [A] ≦ 0.4
It is a toner for developing an electrostatic charge image. [B] / [A] means the mass ratio of B and A.
In order to suppress the deformation at the time of transfer of the toner containing the crystalline polyester, it can be suppressed to some extent by giving the amorphous polymer strength. However, in order to maintain the low-temperature fixability, the molecular weight of the amorphous polymer must be set to a certain level. Therefore, conventionally, in order to ensure the strength while suppressing the overall molecular weight, the toner is given strength by using a crosslinking component.
However, crystalline polyester is usually aliphatic, and the aliphatic cross-linking component is less affected by steric hindrance etc. to this crystalline polyester and can improve the adhesion between the surface layer and the inside, while improving the strength. I can't let you. Therefore, the strength can be improved while the adhesion is maintained by adding the aromatic crosslinking component at a ratio of 10 to 40% with respect to the aliphatic crosslinking component.

  The toner used in the image forming apparatus of the present invention contains at least a crystalline polyester and an amorphous polymer as a binder resin. In this case, the content of the amorphous polymer contained in the toner is preferably 30% by weight or more of the whole binder resin, more preferably 30 to 50% by weight, and 40 to 50% by weight. More preferably. When the content of the amorphous polymer contained in the toner is less than 30% by weight, the amount of deformation of the toner remaining on the photoconductor after passing through the transfer nip increases, and the image is lost due to adhesion of the toner to the photoconductor. In some cases, image quality failure may occur.

The melting point of the toner used in the image forming apparatus of the present invention is preferably in the range of 45 to 110 ° C, and more preferably in the range of 60 to 90 ° C. Since the toner sharply decreases in viscosity at the boundary of the melting point, blocking occurs when the toner is stored in a temperature environment equal to or higher than the melting point. Therefore, it is preferable that the melting point of the toner is not less than a lower limit temperature in a general high-temperature environment that is exposed when the toner is stored or after an image is formed, that is, not less than 45 ° C. On the other hand, when the melting point exceeds 110 ° C., low-temperature fixing may not be possible.
This melting point can be determined as the melting peak temperature of the input compensated differential scanning calorimetry based on JIS K-7121. The crystalline resin may show a plurality of melting peaks, but the maximum peak is regarded as the melting point.

  “Crystallinity” like the crystalline polyester used in the toner used in the image forming apparatus of the present invention has a clear endothermic peak, not a stepwise endothermic amount change in differential scanning calorimetry (DSC). Specifically, it means that the half-value width of the endothermic peak when measured at a heating rate of 10 ° C./min is within 6 ° C. On the other hand, a resin whose half width exceeds 6 ° C. or a resin in which no clear endothermic peak is observed means an amorphous resin (amorphous polymer). As an amorphous polymer used in the present invention, It is preferable to use a resin that does not have a clear endothermic peak.

  In addition, the “crystalline polyester resin” used in the toner used in the image forming apparatus of the present invention is composed of a component that forms a polyester and other components, in addition to a polymer having a 100% polyester structure. This also means a polymer (copolymer). However, in the latter case, the other component other than the polyester constituting the polymer (copolymer) is 50% by weight or less.

  When the crystalline polyester resin is composed of a monomer other than aliphatic, such as aromatic, the melting point of the crystalline polyester resin is increased, resulting in an increase in the melting point of the finally produced toner and an increase in the fixing temperature of the toner. It is expected to invite. In addition, since the emulsifiability of the resin necessary for producing toner by the emulsification granulation method is deteriorated, it is difficult to control the particle size distribution at the time of toner granulation, and uneven distribution of the colorant tends to occur. On the other hand, when an aromatic sulfonic acid monomer is used as a constituent component in order to lower the melting point and impart emulsifying properties, even if the melting point can be lowered and the emulsifying property can be improved, the electrical resistance necessary for imparting toner chargeability can be reduced. As a result, the application range for satisfying the toner characteristics is narrowed. Therefore, in order to enhance the improvement effect on the low-temperature fixability, it is desirable that the constituent ratio of the aliphatic monomer is 80 mol% or more.

The volume average particle diameter of the toner is preferably about 2 to 10 μm, more preferably 3 to 8 μm, and still more preferably 5 to 7 μm. Further, it is preferable that the toner particle size distribution is narrow, and more specifically, the ratio of the 16% diameter (abbreviated as D16p) and the 84% diameter (D84p) in terms of the smaller toner particle diameter is expressed as a square root. (GSDp), that is, GSDp represented by the following formula is preferably 1.40 or less, more preferably 1.31 or less, and particularly preferably 1.20 to 1.27.
GSDp = {(D84p) / (D16p)} ^0.5
If the volume average particle diameter and GSDp are both in the above ranges, transfer is good even with the toner in the layer farthest from the transfer target in the transfer process of the electrophotographic process.

  The toner shape factor SF1 is preferably in the range of 110 to 140, more preferably 120 to 140. It is well known that spherical toner is easier to transfer in the transfer process in the electrophotographic process, and that irregular toner is easier to clean in the cleaning process. The SF1 range of the present invention is preferable for color reproduction in a region having a small amount.

  As the component constituting the toner of the present invention, as long as it contains at least a crystalline polyester, an amorphous crosslinking component, and an amorphous polymer containing an aromatic crosslinking component as a binder resin, as described above. Although it does not limit, other components, such as a mold release agent, may be included as needed. The method for producing the toner of the present invention is not particularly limited, but it is preferable to use a wet method. Hereinafter, the components and the production method of the toner of the present invention will be described in detail.

-Binder resin: Crystalline polyester resin and other polyester resins-
The crystalline polyester resin used for the toner used in the image forming apparatus of the present invention and all other polyester resins are synthesized from a polyvalent carboxylic acid component and a polyhydric alcohol component. In the present invention, a commercially available product may be used as the polyester resin, or an appropriately synthesized product may be used.

  Examples of the polyvalent carboxylic acid component include oxalic acid, succinic acid, glutaric acid, adipic acid, peric acid, azelaic acid, sebacic acid, 1,9-nonanedicarboxylic acid, 1,10-decanedicarboxylic acid, 1,12 -Aliphatic dicarboxylic acids such as dodecanedicarboxylic acid, 1,14-tetradecanedicarboxylic acid, 1,18-octadecanedicarboxylic acid, phthalic acid, isophthalic acid, terephthalic acid, naphthalene-2,6-dicarboxylic acid, malonic acid, mesaconic acid Aromatic dicarboxylic acids such as dibasic acids such as, and the like, and anhydrides and lower alkyl esters thereof are also included, but not limited thereto.

  Examples of the trivalent or higher carboxylic acid include 1,2,4-benzenetricarboxylic acid, 1,2,5-benzenetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid, and the like, and anhydrides thereof. And the lower alkyl esters. These may be used individually by 1 type and may use 2 or more types together.

  Moreover, as an acid component, it is preferable that the dicarboxylic acid component which has a sulfonic acid group other than the above-mentioned aliphatic dicarboxylic acid and aromatic dicarboxylic acid is contained. The dicarboxylic acid having a sulfonic acid group is effective in that it can favorably disperse a coloring material such as a pigment. Also, when the fine particles are prepared by emulsifying or suspending the entire resin in water, a sulfonic acid group is preferable because it can be emulsified or suspended without using a surfactant as described later. .

  Examples of the dicarboxylic acid having a sulfone group include, but are not limited to, 2-sulfoterephthalic acid sodium salt, 5-sulfoisophthalic acid sodium salt, and sulfosuccinic acid sodium salt. Moreover, these lower alkyl esters, acid anhydrides, etc. are also mentioned. The divalent or higher carboxylic acid component having a sulfonic acid group is preferably contained in an amount of 1 to 15 mol%, more preferably 2 to 10 mol%, based on all carboxylic acid components constituting the polyester. When the content is within the above range, the stability of the emulsified particles is good, the crystallinity of the polyester resin is improved, and the toner diameter can be easily adjusted without adversely affecting the process of coalescence after aggregation. Therefore, it is preferable.

  Furthermore, it is more preferable to contain a dicarboxylic acid component having a double bond in addition to the aforementioned aliphatic dicarboxylic acid and aromatic dicarboxylic acid. A dicarboxylic acid having a double bond can be suitably used to prevent hot offset at the time of fixing in that it can be radically cross-linked through a double bond. Examples of such dicarboxylic acids include, but are not limited to, maleic acid, fumaric acid, 3-hexenedioic acid, and 3-octenedioic acid. In addition, these lower esters, acid anhydrides and the like are also included. Among these, fumaric acid and maleic acid are preferable from the viewpoint of cost.

As the polyhydric alcohol component, an aliphatic diol is preferable, and a linear aliphatic diol having 7 to 20 carbon atoms in the main chain portion is more preferable. When the aliphatic diol is branched, the crystallinity of the polyester resin is lowered and the melting point is lowered, so that toner blocking resistance, image storage stability, and low-temperature fixability may be deteriorated.
Further, it is preferable that the carbon number is in the above range since the melting point is good even when polycondensation with an aromatic dicarboxylic acid, and low-temperature fixing is possible. Furthermore, it is preferable because practical materials are easily available. The carbon number is more preferably 14 or less.

  Specific examples of the aliphatic diol suitably used for the synthesis of the crystalline polyester used in the toner of the present invention include ethylene glycol, 1,3-propanediol, 1,4-butanediol, and 1,5. -Pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12- Examples include, but are not limited to, dodecanediol, 1,13-tridecanediol, 1,14-tetradecanediol, 1,18-octadecanediol, 1,14-eicosandecanediol, and the like. Among these, 1,8-octanediol, 1,9-nonanediol, and 1,10-decanediol are preferable in view of availability.

  Examples of the trivalent or higher alcohol include glycerin, trimethylolethane, trimethylolpropane, pentaerythritol and the like. These may be used individually by 1 type and may use 2 or more types together.

  Among the polyhydric alcohol components, the content of the aliphatic diol component is preferably 80 mol% or more, and more preferably 90% or more. It is preferable that the content of the aliphatic diol component is 80 mol% or more because the crystallinity of the polyester resin is good, a suitable melting point is obtained, and toner blocking resistance, image storage stability, and low-temperature fixability are excellent. .

  If necessary, monovalent acids such as acetic acid and benzoic acid, and monovalent alcohols such as cyclohexanol and benzyl alcohol can be used for the purpose of adjusting the acid value and the hydroxyl value.

-Binder resin: Amorphous polymer-
The amorphous polymer used in the toner of the present invention contains an aliphatic crosslinking component A and an aromatic crosslinking component B. Further, when the content of A is [A] and the content of B is [B], 0.1 ≦ [B] / [A] ≦ 0.4 is satisfied.

Specific examples of the aliphatic crosslinking component include (meth) acrylic acid esters of linear polyhydric alcohols such as butanediol methacrylate, hexanediol acrylate, octanediol methacrylate, decanediol acrylate, and dodecanediol methacrylate; neopentyl glycol dimethacrylate Branched, substituted polyhydric alcohol (meth) acrylates such as 2-hydroxy-1,3-diaacryloxypropane; polyethylene glycol di (meth) acrylate, polypropylene polyethylene glycol di (meth) acrylates; Divinyl acid, divinyl fumarate, vinyl maleate / divinyl, divinyl diglycolate, vinyl itaconate / divinyl, divinyl acetone dicarboxylate, divinyl glutarate, 3,3′-thio Polyvinyl of polyvalent carboxylic acids such as divinyl odipropionate, divinyl trans-aconitic acid / trivinyl, divinyl adipate, divinyl pimelate, divinyl suberate, divinyl azelate, divinyl sebacate, divinyl dodecanedioate, divinyl bramate Examples include esters.
Among these, divinyl adipate is preferably used.

Specific examples of the aromatic crosslinking component include aromatic polyvinyl compounds such as divinylbenzene and divinylnaphthalene; divinyl phthalate, divinyl isophthalate, divinyl terephthalate, divinyl homophthalate, divinyl trimesate / trivinyl, naphthalene dicarboxylic acid Polyvinyl esters of aromatic polyvalent carboxylic acids such as divinyl and divinyl biphenyl carboxylates; divinyl esters of nitrogen-containing aromatic compounds such as divinyl pyridine dicarboxylate; vinyl pyromutinate, vinyl furan carboxylate, pyrrole-2-carboxylic acid Vinyl esters of unsaturated heterocyclic compounds such as vinyl acid and vinyl thiophenecarboxylate.
Of these, divinylbenzene is preferably used.

In the present invention, these crosslinking agents may be used alone or in combination of two or more.
The content of the crosslinking agent is preferably in the range of 0.05 to 5% by weight, more preferably in the range of 0.1 to 1.0% by weight, based on the total amount of polymerizable monomers.

  Examples of the amorphous polymer resin used in the toner of the present invention include conventionally known thermoplastic binder resins, and specific examples include styrenes such as styrene, parachlorostyrene, and α-methylstyrene. Homopolymer or copolymer (styrene resin) of methyl acrylate, ethyl acrylate, n-propyl acrylate, n-butyl acrylate, lauryl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, methacrylic acid Homopolymers or copolymers of vinyl-containing esters such as ethyl, n-propyl methacrylate, lauryl methacrylate, 2-ethylhexyl methacrylate, etc .; vinyl nitriles such as acrylonitrile and methacrylonitrile Homopolymer or copolymer (vinyl resin); vinyl methyl ether, vinyl Homopolymers or copolymers of vinyl ethers such as isobutyl ether (vinyl resins); Homopolymers or copolymers of vinyl ketones such as vinyl methyl ketone, vinyl ethyl ketone, vinyl isopropenyl ketone (vinyl resins); Homopolymers or copolymers of olefins such as ethylene, propylene, butadiene, and isoprene (olefin resins); non-vinyl condensation resins such as epoxy resins, polyester resins, polyurethane resins, polyamide resins, cellulose resins, and polyether resins , And graft polymers of these non-vinyl condensation resins and vinyl monomers. These resins may be used alone or in combination of two or more. Among these resins, vinyl resins are preferable, and copolymers of styrenes and (meth) acrylic esters are particularly preferable.

  In the case of a vinyl resin, it is advantageous in that a resin particle dispersion can be easily prepared by emulsion polymerization or seed polymerization using an ionic surfactant or the like. Examples of the vinyl monomer include acrylic acid, methacrylic acid, maleic acid, cinnamic acid, fumaric acid, vinyl sulfonic acid, ethylene imine, vinyl pyridine, vinyl amine, and other vinyl polymer acids and vinyl polymer bases. The monomer used as a raw material is mentioned.

  In the present invention, the resin particles preferably contain the vinyl monomer as a monomer component. In the present invention, among these vinyl monomers, vinyl polymer acids are more preferable from the viewpoint of ease of formation reaction of vinyl resins, and specifically, acrylic acid, methacrylic acid, maleic acid, cinnamon. A dissociable vinyl monomer having a carboxyl group such as an acid or fumaric acid as a dissociating group is particularly preferred from the viewpoint of controlling the degree of polymerization and the glass transition point.

  The concentration of the dissociating group in the dissociable vinyl monomer is such that, for example, particles such as toner particles are dissolved from the surface as described in “Polymer Latex Chemistry” (Polymer Publishing Society, 1970). Then, it can be determined by a method of quantifying. It should be noted that the molecular weight of the resin and the glass transition point from the surface of the particle to the inside can also be determined by the above method or the like.

  The amorphous polymer used in the toner used in the image forming apparatus of the present invention has a weight average molecular weight (Mw) of 5 by molecular weight measurement by gel permeation chromatography (GPC) method soluble in tetrahydrofuran (THF). The number average molecular weight (Mn) is preferably 2,000 to 100,000, and the molecular weight distribution Mw is preferably 7,000 to 1,000,000, more preferably 7,000 to 500,000. / Mn is preferably 1.5 to 100, more preferably 2 to 60.

  When the weight average molecular weight and the number average molecular weight are smaller than the above ranges, while effective for low-temperature fixability, not only the hot offset resistance is remarkably deteriorated, but also the glass transition point of the toner is lowered. It also tends to adversely affect storage stability such as toner blocking. On the other hand, if the molecular weight is larger than the above range, the hot offset resistance can be sufficiently provided, but the low-temperature fixability is deteriorated and the oozing of the crystalline polyester phase present in the toner is inhibited, so that the document storage stability is reduced. May be adversely affected. Therefore, it is preferable to satisfy the above-mentioned conditions because it is easy to achieve both low-temperature fixability, hot offset resistance, and document storage stability.

  In the present invention, the molecular weight of the resin is measured with a THF solvent using a THF soluble material, GPC / HLC-8120 manufactured by Tosoh Corporation, a column / TSKgel SuperHM-M (15 cm) manufactured by Tosoh Corporation, This is a molecular weight calculated using a molecular weight calibration curve prepared with a monodisperse polystyrene standard sample.

  The acid value of the polyester resin (the number of mg of KOH required to neutralize 1 g of resin) is easy to obtain the molecular weight distribution as described above, and is easy to ensure the granulation property of the toner particles by the emulsion dispersion method. In view of the fact that the environmental stability (stability of chargeability when the temperature and humidity change) of the obtained toner is easily maintained, the acid value is preferably higher, specifically 5 to 50 mgKOH / A range of g is preferred. More preferably, it is 10-40 mgKOH / g. The acid value of the polyester resin can be adjusted by controlling the carboxyl group at the terminal of the polyester according to the blending ratio of the raw polyhydric carboxylic acid and polyhydric alcohol and the reaction rate. Or what has a carboxyl group in the principal chain of polyester is obtained by using trimellitic anhydride as a polyvalent carboxylic acid component.

  The glass transition temperature of the amorphous polymer and the crystalline polyester resin used in the present invention is preferably 35 to 100 ° C., and is 50 to 80 ° C. from the viewpoint of the balance between storage stability and toner fixing property. More preferably. When the glass transition temperature is within the above range, the toner is not blocked during storage or in the developing machine (a phenomenon in which the toner particles are aggregated into a lump), and a good toner fixing temperature can be obtained. Therefore, it is preferable.

-Colorant-
A colorant can also be used for the toner used in the image forming apparatus of the present invention. The colorant used in the toner of the present invention is not particularly limited as long as it is a known colorant, and examples thereof include carbon black such as furnace black, channel black, acetylene black, and thermal black, bengara, bitumen, and titanium oxide. Inorganic pigments, fast yellow, disazo yellow, pyrazolone red, chelate red, brilliant carmine, para brown and other azo pigments, copper phthalocyanine, metal-free phthalocyanine and other phthalocyanine pigments, flavantron yellow, dibromoanthrone orange, perylene red, quinacridone red, Examples thereof include condensed polycyclic pigments such as dioxazine violet.

  Chrome Yellow, Hansa Yellow, Benzidine Yellow, Slen Yellow, Quinoline Yellow, Permanent Orange GTR, Pyrarozone Orange, Vulcan Orange, Watch Young Red, Permanent Red, Dupont Oil Red, Resol Red, Rhodamine B Lake, Lake Red C, Rose Bengal, aniline blue, ultramarine blue, calco oil blue, methylene blue chloride, phthalocyanine blue, phthalocyanine green, malachite green oxalate, C.I. I. Pigment red 48: 1, C.I. I. Pigment red 122, C.I. I. Pigment 57: 1, C.I. I. Pigment yellow 12, C.I. I. Pigment yellow 97, C.I. I. Pigment yellow 17, C.I. I. Pigment yellow 180, C.I. I. Pigment yellow 74, C.I. I. Pigment blue 15: 1, C.I. I. Examples thereof include various pigments such as CI Pigment Blue 15: 3, and these can be used alone or in combination of two or more.

In the toner used in the image forming apparatus of the present invention, the content of the colorant is preferably 1 to 20% by weight, and preferably 1 to 10% by weight with respect to 100 parts by weight of the binder resin. More preferably, it is more preferably 2 to 10% by weight, particularly preferably 2 to 7% by weight, and it is preferably as much as possible as long as the smoothness of the image surface after fixing is not impaired. It is also effective to use a surface-treated colorant or a pigment dispersant as necessary. By appropriately selecting the type of the colorant, yellow toner, magenta toner, cyan toner, black toner and the like can be obtained.
When a magnetic material is used as the black colorant, it is added in the range of 30 to 100% by weight, unlike other colorants.

-Release agent-
The toner of the present invention may contain a release agent. The release agent used is not particularly limited as long as it is a known release agent. For example, natural waxes such as carnauba wax, rice wax, and candelilla wax, low molecular weight polypropylene, low molecular weight polyethylene, sasol wax, Examples include, but are not limited to, synthesis of microcrystalline wax, Fischer-Tropsch wax, paraffin wax, montan wax and the like, and ester-based waxes such as mineral / petroleum wax, fatty acid ester, and montanic acid ester. Moreover, these mold release agents may be used individually by 1 type, and may be used together 2 or more types.

  The melting point of the release agent is preferably 50 ° C. or higher, more preferably 60 ° C. or higher, from the viewpoint of storage stability. Moreover, it is preferable that it is 110 degrees C or less from a viewpoint of offset resistance, and it is more preferable that it is 100 degrees C or less.

The content of the release agent is preferably in the range of 1 to 30 parts by weight and more preferably in the range of 2 to 20 parts by weight with respect to 100 parts by weight of the binder resin. When the content of the release agent is within the above range, the effect of addition of the release agent can be obtained and hot offset at a high temperature is not caused, which is preferable. Furthermore, the charging property is not adversely affected, and the mechanical strength of the toner is not lowered. Also when used as a color toner, it is preferable because no domain remains in the fixed image and good OHP transparency is obtained.
In the present invention, as described below, a toner containing no release agent can also be used.

-Other additives-
In addition to the above-described components, various components such as an internal additive, a charge control agent, inorganic powder (inorganic fine particles), and organic fine particles can be added to the toner of the present invention as necessary. .

  Examples of the internal additive include metals such as ferrite, magnetite, reduced iron, cobalt, nickel, and manganese, alloys, and magnetic materials such as compounds containing these metals.

  Examples of the charge control agent include quaternary ammonium salt compounds, nigrosine compounds, dyes composed of complexes of aluminum, iron, chromium, and triphenylmethane pigments. The inorganic powder is added mainly for the purpose of adjusting the viscoelasticity of the toner. For example, silica, alumina, titania, calcium carbonate, magnesium carbonate, calcium phosphate, cerium oxide, etc. Examples thereof include all inorganic fine particles used as an external additive on the toner surface.

Inorganic fine particles or organic fine particles may be externally added to the surface of the toner of the present invention. In particular, it is preferable to externally add inorganic fine particles.
Examples of inorganic fine particles and organic fine particles that are externally added to the toner surface include the following. Examples of the inorganic fine particles include silica, alumina, titanium oxide, barium titanate, magnesium titanate, calcium titanate, strontium titanate, zinc oxide, silica sand, clay, mica, wollastonite, diatomaceous earth, cerium chloride, Examples include Bengala, chromium oxide, cerium oxide, antimony trioxide, magnesium oxide, zirconium oxide, silicon carbide, and silicon nitride. Among them, silica fine particles and titanium oxide fine particles are preferable, and hydrophobized fine particles are particularly preferable.

  Inorganic fine particles are generally used for the purpose of improving fluidity, transferability, chargeability and the like. The primary particle diameter of the inorganic fine particles is preferably 1 to 200 nm, and the addition amount is preferably 0.01 to 20 parts by weight with respect to 100 parts by weight of the toner.

  Organic fine particles are generally used for the purpose of improving cleaning properties and transfer properties, and specific examples include polystyrene, polymethyl methacrylate, polyvinylidene fluoride, and the like.

<Toner production method>
The method for producing the toner of the present invention is not particularly limited, but it is preferably produced by a wet granulation method. Examples of the wet granulation method include known melt suspension methods, emulsion aggregation methods, and dissolution suspension methods. Among these methods, the emulsion aggregation method is preferably used in the present invention.
When the amorphous polymer is emulsion-polymerized, the aromatic cross-linking component is polymerized earlier and the aliphatic cross-linking component is polymerized later, so that the aromatic cross-linking component is present inside the particle and the aliphatic cross-linking component is present on the particle surface. Become. Therefore, the adhesiveness to the inside can be maintained by the aliphatic cross-linking component while maintaining the strength by the aromatic cross-linking component, which is preferable because the strength as a toner can be maintained.
When using the emulsion aggregation method, the method for producing a toner for developing an electrostatic charge image of the present invention comprises an emulsification step of preparing a dispersion containing at least crystalline polyester fine particles, and forming aggregated particles containing the crystalline polyester in the dispersion. It is preferable to include at least a coagulating step and an attaching step of attaching amorphous polymer fine particles to the surface of the aggregated particles, and further including a fusion step of fusing the aggregated particles by heating. preferable. Hereinafter, each step will be described in detail.

-Emulsification process-
In the emulsification step, the raw material dispersion is a solution in which a binder resin emulsified particle (hereinafter abbreviated as “resin particle”) is mixed with a dispersion containing an aqueous medium and, if necessary, a colorant and a release agent. Is formed by applying a shearing force. Therefore, the binder resin needs to be dispersed in advance as resin particles in the raw material dispersion.

  The average particle diameter of the resin particles is preferably 1 μm or less, and more preferably 0.01 to 1 μm. When the average particle size is within the above range, the particle size distribution of the electrostatic latent image developing toner obtained in the final period is narrow, and free particles are not generated, thereby improving performance and reliability. Therefore, it is preferable. Further, the uneven distribution between the toners is reduced, the dispersion in the toners is improved, and the variation in performance and reliability is advantageous. The volume average particle diameter can be measured using, for example, a Coulter counter.

  Examples of the dispersion medium in the dispersion include an aqueous medium and an organic solvent. Examples of the aqueous medium include water such as distilled water and ion exchange water, and alcohols. These may be used individually by 1 type and may use 2 or more types together. In the present invention, it is preferable to add and mix a surfactant in the aqueous medium. The surfactant is not particularly limited. For example, anionic surfactants such as sulfate ester, sulfonate, phosphate, and soap; amine salts, quaternary ammonium salts, and the like Nonionic surfactants such as polyethylene glycol-based, alkylphenol ethylene oxide adduct-based, polyhydric alcohol-based, and the like. Among these, anionic surfactants and cationic surfactants are preferable. The nonionic surfactant is preferably used in combination with the anionic surfactant or the cationic surfactant. The said surfactant may be used individually by 1 type, and may use 2 or more types together.

  Specific examples of the anionic surfactant include sodium dodecylbenzenesulfonate, sodium dodecylsulfate, sodium alkylnaphthalenesulfonate, sodium dialkylsulfosuccinate and the like. Specific examples of the cationic surfactant include alkylbenzene dimethyl ammonium chloride, alkyl trimethyl ammonium chloride, distearyl ammonium chloride and the like. Among these, ionic surfactants such as anionic surfactants and cationic surfactants are preferable. Examples of the organic solvent include ethyl acetate and toluene, which are appropriately selected according to the binder resin.

  When the resin particle is a homopolymer or copolymer (vinyl resin) of a vinyl monomer such as the ester having a vinyl group, the vinyl nitrile, the vinyl ether, or the vinyl ketone. By conducting emulsion polymerization or seed polymerization of the vinyl monomer in an ionic surfactant, resin particles made of a vinyl monomer homopolymer or copolymer (vinyl resin) are made ionic. A dispersion obtained by dispersing in a surfactant is prepared.

When the resin particle is a resin other than a homopolymer or a copolymer of the vinyl monomer, the resin can be dissolved in an oily solvent having a relatively low solubility in water. The resin is dissolved in the oily solvent, and this solution is dispersed in water together with an ionic surfactant and polymer electrolyte using a disperser such as a homogenizer, and then the oily solvent is evaporated by heating or decompression. Thus, a dispersion liquid in which resin particles made of resin other than vinyl resin are dispersed in an ionic surfactant is prepared.

  On the other hand, when the resin particle is a crystalline polyester and an amorphous polyester resin, it contains a functional group that can become an anionic type by neutralization, and has a self-water dispersibility. A stable aqueous dispersion can be formed under the action of an aqueous medium, all neutralized with a base. In the crystalline polyester and the amorphous polyester resin, the functional group that can become a hydrophilic group by neutralization is an acidic group such as a carboxyl group or a sulfone group. As the neutralizing agent, for example, sodium hydroxide, potassium hydroxide, water Examples thereof include inorganic bases such as lithium oxide, calcium hydroxide, sodium carbonate and ammonia, and organic bases such as diethylamine, triethylamine and isopropylamine.

  Further, when a polyester resin that does not disperse in water, that is, does not have self-water dispersibility, is used as a binder resin, the resin solution and / or an aqueous medium mixed with the resin solution, as described later, 1 μm easily when dispersed with a polymer electrolyte such as a surfactant, polymer acid, polymer base, etc., heated above the melting point, and treated with a homogenizer or pressure discharge type disperser capable of applying a strong shear force The following microparticles can be made. When this ionic surfactant or polymer electrolyte is used, it is appropriate that the concentration in the aqueous medium is about 0.5 to 5 wt%.

  As the colorant mixed with the resin dispersion in the emulsification step, the colorants described above can be used. As a method of dispersing the colorant, any method such as a general dispersion method such as a rotary shearing homogenizer, a ball mill having a medium, a sand mill, or a dyno mill can be used, and the method is not limited at all. If necessary, an aqueous dispersion of these colorants can be prepared using a surfactant, or an organic solvent dispersion of these colorants can be prepared using a dispersant. Hereinafter, such a colorant dispersion may be referred to as a “colored particle dispersion”. As the surfactant and the dispersing agent used for dispersion, the same dispersing agents that can be used when dispersing the binder resin can be used.

  The addition amount of the colorant is preferably 1 to 20% by weight, more preferably 1 to 10% by weight, and more preferably 2 to 10% by weight with respect to the total amount of the binder resin. More preferably, it is 2 to 7% by weight, and it is preferably as much as possible as long as the smoothness of the image surface after fixing is not impaired. When the content of the colorant is increased, the thickness of the image can be reduced when an image having the same density is obtained, which is advantageous in terms of prevention of offset. These colorants may be added to the mixed solvent at the same time as other fine particle components, or may be divided and added in multiple stages.

  As the release agent mixed with the resin dispersion in the emulsification step, the release agent described above can be used. As with the case of emulsifying and dispersing a polyester resin that does not have self-water dispersibility, the release agent is dispersed together with an ionic surfactant or the like in water, heated above the melting point, and can be applied with a strong shearing force. Using a pressure discharge type disperser, the dispersed fine particle diameter is adjusted to 1 μm or less. As the dispersion medium in the release agent dispersion, the same dispersion medium as that for the binder resin can be used.

  In the present invention, as an apparatus for mixing and dispersing the binder resin and the release agent with an aqueous medium, for example, a homomixer (Special Machine Industries Co., Ltd.), a slasher (Mitsui Mine Co., Ltd.), Cavitron (stock) Examples include continuous emulsifying and dispersing machines such as Eurofluid Co., Ltd., Microfluidizer (Mizuho Industrial Co., Ltd.), Menton Gorin homogenizer (Gorin Inc.), Nanomizer (Nanomizer Inc.), Static Mixer (Noritake Company), and the like.

  The content of the resin particles contained in the binder resin dispersion in the emulsification step and the content of each of the colorant and the release agent in the dispersion of the colorant and the release agent are preferably 5 to 50% by weight, More preferably, it is 10 to 40% by weight. It is preferable for the content to be in the above range because the particle size distribution is narrow and good characteristics are obtained.

  In the present invention, other components such as an internal additive, a charge control agent, and an inorganic powder as described above may be dispersed in the binder resin dispersion according to the purpose. The charge control agent in the present invention is preferably made of a material that is difficult to dissolve in water in terms of controlling ionic strength that affects the stability of the aggregation process and the fusion process and reducing wastewater contamination.

  The volume average particle size of the other components is preferably 1 μm or less, and more preferably 0.01 to 1 μm. When the average diameter is within the above range, the particle size distribution of the finally obtained electrostatic latent image developing toner is narrow, and free particles are not generated, so that good performance and reliability can be obtained. preferable. Further, it is advantageous in that uneven distribution between toners is reduced, dispersion in the toner is good, and variations in performance and reliability are reduced.

-Aggregation process-
In the agglomeration step, the resin particles obtained in the emulsification step, and the colorant and release agent dispersion are mixed (hereinafter, this mixture is referred to as “raw material dispersion”), and the temperature near the melting point of the binder resin. In addition, the particles are heated at a temperature equal to or lower than the melting point to form aggregated particles in which the respective dispersed particles are aggregated.

  Aggregated particles are formed by adding a flocculant at room temperature under stirring with a rotary shearing homogenizer to make the pH of the raw material dispersion acidic. The pH is preferably 3.5 to 6 and more preferably 4 to 6 when a vinyl copolymer is used as the amorphous polymer of the binder resin.

  As the aggregating agent used in the aggregating step, a surfactant having a polarity opposite to that of the surfactant used for the dispersant, an inorganic metal salt, and a divalent or higher-valent metal complex can be preferably used. The use of a metal complex is particularly preferred because the amount of surfactant used can be reduced and charging characteristics are improved.

Examples of the inorganic metal salt include metal salts such as calcium chloride, calcium nitrate, barium chloride, magnesium chloride, zinc chloride, aluminum chloride, and aluminum sulfate, and polyaluminum chloride, polyaluminum hydroxide, and calcium polysulfide. Examples thereof include inorganic metal salt polymers. Of these, aluminum salts and polymers thereof are particularly preferred. In order to obtain a sharper particle size distribution, the valence of the inorganic metal salt is bivalent than monovalent, trivalent than bivalent, trivalent than trivalent, and tetravalent than trivalent. The inorganic metal salt polymer is more suitable.
In the agglomeration step, it is preferable to adjust the pH at the stage of stirring and mixing at room temperature in order to suppress rapid aggregation due to heating, and add a dispersion stabilizer as necessary (hereinafter, this stage is referred to as “ Called pre-aggregation step). As the dispersion stabilizer used in this pre-aggregation step, it is preferable to add 1 to 3% of a known nonionic surfactant so as not to change the polarity. It is preferable to add a dispersion stabilizer because the fine particles of the raw material particles can be taken in well in the heat aggregation step, and as a result, a narrow particle size distribution can be obtained. Further, it is effective to add the dispersion stabilizer separately in both the pre-aggregation step and the heat aggregation step.

-Adhesion process-
In the attaching step, the amorphous polymer particles are attached to the surface of the agglomerated particles containing the crystalline polyester (hereinafter abbreviated as “core agglomerated particles”) formed through the agglomeration step, thereby forming a coating layer ( Hereinafter, the core aggregated particle surface provided with a coating layer is abbreviated as “attached aggregated particle”). This coating layer corresponds to the surface layer of the toner of the present invention formed through a fusion process described later. The coating layer can be formed by additionally adding a dispersion containing amorphous polymer particles to the dispersion in which the core aggregated particles are formed in the aggregation process, and other components can be added simultaneously as necessary. It may be added. Also in the adhesion step, the pH and the flocculant are selected in the same manner as in the aggregation step according to the amorphous polymer to be used, and the binder resin having the lowest melting point among the two or more types of binder resins contained in the adhered aggregated particles. Adhesive aggregated particles can be obtained by heating at a temperature below the melting point. This adhesion process is also effective in leading the raw material fine particles that have not been taken into the aggregated particles at the pre-aggregation stage.

-Fusion process-
In the fusion step, under the same agitation as in the agglomeration step, the pH of the suspension of the adhered agglomerated particles is set in the range of 6.5 to 8.5 to stop the agglomeration, and then the binder resin The adhered aggregated particles are fused by heating at a temperature equal to or higher than the melting point. Although depending on the liquidity of the dispersion containing the adhered aggregated particles, if the pH at which aggregation is stopped is not an appropriate pH, the adhered aggregated particles will be scattered during the temperature rising process for coalescence, resulting in poor yield. Become. Moreover, you may implement a fusion process, after obtaining an aggregation process as needed.

  There is no problem if the heating temperature at the time of fusion is not lower than the melting point of the binder resin contained in the adhered and agglomerated particles. The heating time may be performed so that the fusion is sufficiently performed, and may be performed for about 0.5 to 1.5 hours. If it takes more time, the crystalline polyester contained in the core aggregated particles is likely to be exposed on the toner surface. Therefore, although it is effective for fixing property and document storage property, it is not preferable to heat for a long time because it adversely affects charging property.

  In the fusion step, a crosslinking reaction may be performed when the binder resin is heated to the melting point or higher, or after the fusion is completed. In addition, a crosslinking reaction can be performed simultaneously with the fusion. When the crosslinking reaction is performed, for example, an unsaturated sulfonated crystalline polyester resin obtained by copolymerizing a double bond component as a binder resin is used, and a radical reaction is caused to the resin to introduce a crosslinked structure. . At this time, the following polymerization initiator is used.

  Examples of the polymerization initiator include t-butyl peroxy-2-ethylhexanoate, cumyl perpivalate, t-butyl peroxylaurate, benzoyl peroxide, lauroyl peroxide, octanoyl peroxide, di-t. -Butyl peroxide, t-butyl cumyl peroxide, dicumyl peroxide, 2,2'-azobisisobutyronitrile, 2,2'-azobis (2-methylbutyronitrile), 2,2'-azobis (2,4-dimethylvaleronitrile), 2,2′-azobis (4-methoxy-2,4-dimethylvaleronitrile), 1,1-bis (t-butylperoxy) 3,3,5-trimethylcyclohexane 1,1-bis (t-butylperoxy) cyclohexane, 1,4-bis (t-butylperoxyca) Bonyl) cyclohexane, 2,2-bis (t-butylperoxy) octane, n-butyl 4,4-bis (t-butylperoxy) valerate, 2,2-bis (t-butylperoxy) butane, , 3-bis (t-butylperoxyisopropyl) benzene, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane, 2,5-dimethyl-2,5-di (t-butylper) Oxy) hexane, 2,5-dimethyl-2,5-di (benzoylperoxy) hexane, di-t-butyldiperoxyisophthalate, 2,2-bis (4,4-di-t-butylperoxy) (Cyclohexyl) propane, di-t-butylperoxy α-methylsuccinate, di-t-butylperoxydimethylglutarate, di-t-butylperoxyhexahydrotereph Tartrate, di-t-butylperoxyazelate, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane, diethylene glycol-bis (t-butylperoxycarbonate), di-t-butylper Oxytrimethyl adipate, tris (t-butylperoxy) triazine, vinyltris (t-butylperoxy) silane, 2,2'-azobis (2-methylpropionamidine dihydrochloride), 2,2'-azobis [N- (2-carboxyethyl) -2-methylpropionamidine], 4,4′-azobis (4-cyanovaleric acid) and the like.

  These polymerization initiators can be used alone or in combination of two or more. The amount and type of the polymerization initiator are selected depending on the amount of unsaturated sites in the polymer and the type and amount of the coexisting colorant. The polymerization initiator may be mixed with the polymer in advance before the emulsification step, or may be incorporated into the aggregate in the aggregation step. Further, it may be introduced after the fusion step or after the fusion step. In the case where the polymerization initiator is introduced after the aggregation step, the adhesion step, the fusion step, or the fusion step, a solution in which the polymerization initiator is dissolved or emulsified is added to a particle dispersion (resin particle dispersion or the like). These polymerization initiators may be added with known crosslinking agents, chain transfer agents, polymerization inhibitors and the like for the purpose of controlling the degree of polymerization.

  The fused particles obtained by fusing can be made into toner particles through a solid-liquid separation process such as filtration and, if necessary, a washing process and a drying process. In this case, in order to ensure sufficient charging characteristics and reliability as a toner, it is preferable to sufficiently wash in the washing step.

  In the drying process, an arbitrary method such as a normal vibration type fluidized drying method, a spray drying method, a freeze drying method, or a flash jet method can be adopted. The toner particles should have a moisture content after drying of preferably 1.0% or less, more preferably 0.5% or less.

  As described above, various known external additives such as inorganic fine particles and organic fine particles as described above can be added to the toner particles granulated through the drying step as described above according to the purpose.

<Developer>
In the present invention, the above-described toner can be used as it is as a one-component developer or as a two-component developer. When used as a two-component developer, it is used by mixing with a carrier. The developer is preferably used as a two-component developer.
There is no restriction | limiting in particular as a carrier which can be used for a two-component developer, A well-known carrier can be used. Examples thereof include magnetic metals such as iron oxide, nickel and cobalt, magnetic oxides such as ferrite and magnetite, resin-coated carriers having a resin coating layer on the surface of the core material, and magnetic dispersion carriers. Further, a resin-dispersed carrier in which a conductive material or the like is dispersed in a matrix resin may be used.

  Coating resins and matrix resins used for carriers include polyethylene, polypropylene, polystyrene, polyvinyl acetate, polyvinyl alcohol, polyvinyl butyral, polyvinyl chloride, polyvinyl ether, polyvinyl ketone, vinyl chloride-vinyl acetate copolymer, styrene-acrylic. Examples thereof include, but are not limited to, acid copolymers, straight silicone resins composed of organosiloxane bonds or modified products thereof, fluororesins, polyesters, polycarbonates, phenol resins, epoxy resins and the like.

  Examples of the conductive material include metals such as gold, silver, and copper, carbon black, titanium oxide, zinc oxide, barium sulfate, aluminum borate, potassium titanate, and tin oxide, but are not limited thereto. It is not a thing.

  Examples of the core material of the carrier include magnetic metals such as iron, nickel and cobalt, magnetic oxides such as ferrite and magnetite, and glass beads. However, in order to use the carrier for the magnetic brush method, it is a magnetic material. It is preferable. The volume average particle size of the carrier core material is preferably 10 to 500 μm, and more preferably 30 to 100 μm.

  In order to coat the surface of the core material of the carrier with a resin, there may be mentioned a method of coating with a coating layer forming solution in which the coating resin and, if necessary, various additives are dissolved in an appropriate solvent. The solvent is not particularly limited and may be appropriately selected in consideration of the coating resin to be used, coating suitability, and the like.

  Specific resin coating methods include an immersion method in which the carrier core material is immersed in a coating layer forming solution, a spray method in which the coating layer forming solution is sprayed on the surface of the carrier core material, and the carrier core material is fluidized air. And a kneader coater method in which the core material of the carrier and the coating layer forming solution are mixed in a kneader coater and the solvent is removed in a kneader coater.

  The mixing ratio (weight ratio) of the toner of the present invention and the carrier in the two-component developer is preferably in the range of toner: carrier = 1: 100 to 30: 100, and 3: 100 to 20: 100. A range of the degree is more preferable.

<Image forming method>
The image forming method of the present invention includes an electrostatic charge image forming step of forming an electrostatic charge image on the surface of an electrostatic charge image (also referred to as an electrostatic latent image), and an electrostatic charge image formed on the surface of the electrostatic charge support. Developing with a developer containing toner to form a toner image, a transfer step for transferring the toner image formed on the surface of the electrostatic charge image carrier to the surface of the transferred body, and a surface of the transferred body Fixing the transferred toner image. The transfer process may include two or more transfer processes using an intermediate transfer member.

  The developer may be either a one-component system or a two-component system. As each of the above steps, a known step in the image forming method can be used. The image forming method of the present invention may include steps other than the steps described above. In the image forming method of the present invention, a plurality of the above steps may be performed simultaneously.

  As the electrostatic charge image carrier, for example, an electrophotographic photosensitive member and a dielectric recording member can be used. In the case of an electrophotographic photosensitive member, the surface of the electrophotographic photosensitive member is uniformly charged by a corotron charger, a contact charger or the like and then exposed to form an electrostatic image (electrostatic image forming step). Next, the toner particles are adhered to the electrostatic charge image by being brought into contact with or in proximity to a developing roll having a developer layer formed on the surface, thereby forming a toner image on the electrophotographic photosensitive member (developing step). The formed toner image is transferred onto the surface of a transfer medium such as paper using a corotron charger or the like (transfer process). Further, the toner image transferred to the surface of the transfer target is heat-fixed by a fixing device, and a final toner image is formed. Note that a release agent may be supplied to a fixing member in the fixing device in order to prevent an offset or the like at the time of heat fixing by the fixing device.

  The toner of the present invention (including those contained in a two-component developer; hereinafter the same) has a cross-linked structure in the binder resin and is excellent in releasability due to its effect. Therefore, it is possible to reduce the amount of the release agent used or to perform fixing without using the release agent.

The release agent is preferably not used from the viewpoint of eliminating oil adhesion to the transfer target and image after fixing. However, when the supply amount of the release agent is 0 mg / cm ² , the fixing agent is fixed during fixing. When the member and the transfer medium such as paper come into contact with each other, the amount of wear of the fixing member may increase and the durability of the fixing member may decrease. A small amount can be supplied to the fixing member in the range of 8.0 × 10 ⁻³ mg / cm ² or less.

When the supply amount of the release agent exceeds 8.0 × 10 ⁻³ mg / cm ² , the image quality deteriorates due to the release agent adhering to the image surface after fixing, and in particular, transmitted light such as OHP is transmitted. When used, such a phenomenon may be prominent. Further, the adhesion of the release agent to the transfer target becomes remarkable, and stickiness may occur. Furthermore, the larger the supply amount of the release agent, the larger the capacity of the tank for storing the release agent, which causes an increase in the size of the fixing device itself.

  Although there is no restriction | limiting in particular as said mold release agent, For example, liquid mold release agents, such as modified oils, such as dimethyl silicone oil, fluorine oil, fluoro silicone oil, and amino modified silicone oil, are mentioned. Among these, modified oils such as amino-modified silicone oil are preferable because they are adsorbed on the surface of the fixing member and can form a homogeneous release agent layer, because they have excellent wettability to the fixing member. Further, from the viewpoint of forming a homogeneous release agent layer, fluorine oil and fluorosilicone oil are preferable.

  The method for supplying the release agent to the surface of the roller or belt, which is a fixing member used for the thermocompression bonding, is not particularly limited. For example, a pad method using a pad impregnated with a liquid release agent, a web method, Examples thereof include a roller method and a non-contact type shower method (spray method). Among these, a web method and a roller method are preferable. These methods are advantageous in that the release agent can be supplied uniformly and it is easy to control the supply amount. In order to supply the release agent uniformly to the entire fixing member by the shower method, it is necessary to use a separate blade or the like.

The supply amount of the release agent can be measured as follows. That is, when a normal paper (typically a copy paper manufactured by Fuji Xerox Co., Ltd., trade name J paper) used in a general copying machine is passed through a fixing member supplied with a release agent on its surface. The release agent adheres to the plain paper. The attached release agent is extracted using a Soxhlet extractor. Here, hexane is used as the solvent.
By quantifying the amount of the release agent contained in the hexane with an atomic absorption analyzer, the amount of the release agent adhering to the plain paper can be quantified. This amount is defined as the amount of release agent supplied to the fixing member.

  Examples of the transfer target (recording material) to which the toner image is transferred include plain paper, OHP sheet, and the like used in electrophotographic copying machines and printers. In order to further improve the smoothness of the image surface after fixing, it is preferable that the surface of the transfer object is as smooth as possible. For example, coated paper in which the surface of plain paper is coated with a resin or the like, art paper for printing Etc. can be used suitably.

  Since the image forming method of the present invention uses the toner or developer of the present invention, low-temperature fixing is possible and the toner can maintain an appropriate triboelectric charge amount. Therefore, it is excellent in energy saving at the time of image formation, and a good image can be formed while preventing the occurrence of toner scattering and the like.

<Toner shape change rate measuring method>
“Toner shape change rate (Tt)” means that at least 50 toners remaining on the photoreceptor after passing through the transfer nip are sampled, and the maximum length x (μm) of the projected image of each of these deformed toner particles. And the maximum length h (μm) of the deformed toner particle projection image formed on the plane perpendicular to the axis of the maximum length direction of the deformed toner particle projection image is obtained by substituting into the following formula (1). It was obtained by averaging the obtained individual values. Note that the x value and h value of each sampled deformed toner particle were measured using an image analysis apparatus (manufactured by Nexus Co., Ltd .: NEXUS).
Tt (%) = (h / x) × 100 (1)
(Where x represents the maximum length (μm) of the modified toner particle projection image, and h represents the modified toner particle projection formed on a plane perpendicular to the axis of the maximum length direction of the modified toner particle projection image. (It represents the maximum length (μm) of the image.)
In the definition of the x value and the h value, the “toner particle projection image” refers to the plane when the toner is placed between a plane screen and a light source that irradiates light substantially perpendicularly thereto. It means a projected image of the toner particles formed on the screen surface.

In the image forming method of the present invention, the toner shape change rate (Tt) is 60 to 100%, and preferably 70 to 100%.
In the electrophotographic process, the change in the shape of the toner in the transfer process is an important phenomenon that determines whether or not an image quality failure such as image omission due to adhesion of the toner to the photoconductor occurs. This is preferable because an image quality failure such as image omission due to adhesion to the photoreceptor is less likely to occur. It is preferable that the change in the shape of the toner in the transfer process is small (Tt is close to 100) because the contact area between the photoconductor and the toner does not increase and the toner is difficult to adhere to the photoconductor.

EXAMPLES Hereinafter, although an Example demonstrates this invention, this invention is not limited to these Examples.
-Preparation of crystalline polyester resin dispersion-
To a heat-dried three-necked flask, 92.5 mol% dimethyl sebacate and 7.5 mol% 5-t-butylisophthalic acid, ethylene glycol (2 mol times the acid component), and Ti (as a catalyst) OBu) ₄ (0.012% by weight with respect to the acid component), and then the pressure in the container is reduced by depressurization, and the atmosphere is inerted with nitrogen gas. Reflux was performed for 5 hours. Thereafter, excess ethylene glycol was removed by distillation under reduced pressure, the temperature was gradually raised to 230 ° C., and the mixture was stirred for 2 hours. When the mixture became viscous, the molecular weight was confirmed by GPC, and the weight average molecular weight was 13,000. Then, distillation under reduced pressure was stopped and air-cooled to obtain crystalline polyester (1).

  Next, 80 parts by weight of the crystalline polyester (1) and 720 parts by weight of deionized water were placed in a stainless beaker, placed in a warm bath, and heated to 95 ° C. When the crystalline polyester resin was melted, the mixture was stirred at 8,000 rpm using a homogenizer (manufactured by IKA: Ultra Tarrax T50). Next, the emulsion was dispersed while adding 20 parts by weight of an aqueous solution obtained by diluting 1.6 parts by weight of an anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd .: Neogen RK), and the volume average particle size was 0.18 μm. A crystalline polyester resin dispersion (1) [resin particle concentration: 10% by weight] was prepared.

-Preparation of amorphous polymer dispersion (1)-
Styrene: 370 parts by weight nbutyl acrylate: 30 parts by weight Acrylic acid: parts by weight Divinyl adipate: 3.2 parts by weight Divinylbenzene: 0.8 parts by weight Dodecanethiol: 20 parts by weight Tetrabromide Carbon: 4 parts by weight Mixing and dissolving the above, 6 parts by weight of a nonionic surfactant (Sanyo Kasei Co., Ltd .: Nonipol 400) and an anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd.) : Neogen SC) Dispersed in 560 parts by weight of ion-exchanged water, dispersed in a flask, emulsified, slowly mixed for 10 minutes, and ion-exchanged water in which 4 parts by weight of ammonium persulfate was dissolved. After charging 50 parts by weight and carrying out nitrogen substitution, the contents in the flask were heated with an oil bath until the contents reached 70 ° C. while stirring, and emulsion polymerization was continued for 5 hours. Thus, an amorphous polymer dispersion (1) (resin particle concentration: 40) obtained by dispersing resin particles having a volume average particle size of 180 nm, a glass transition point of 59 ° C., and a weight average molecular weight (Mw) of 18,000. % By weight) was prepared.

-Preparation of amorphous polymer dispersion (2)-
・ Divinyl adipate: 3.2 parts by weight ・ Divinylbenzene: 0.8 parts by weight ・ Divinyl adipate: 3.6 parts by weight ・ Amorphous polymer dispersion except that divinylbenzene: 0.4 parts by weight is used Amorphous polymer dispersion (2) was prepared in exactly the same manner as liquid (1). Amorphous polymer dispersion (2) obtained by dispersing resin particles having a volume average particle diameter of 180 nm, a glass transition point of 59 ° C., and a weight average molecular weight of 18,000 (resin particle concentration: 40% by weight) ) Was prepared.

-Preparation of amorphous polymer dispersion (3)-
・ Divinyl adipate: 3.2 parts by weight ・ Divinylbenzene: 0.8 parts by weight ・ Divinyl adipate: 2.9 parts by weight ・ Amorphous polymer dispersion other than using 1.1 parts by weight of divinylbenzene Amorphous polymer dispersion (3) was prepared in exactly the same manner as liquid (1). Amorphous polymer dispersion (3) obtained by dispersing resin particles having a volume average particle size of 180 nm, a glass transition point of 59 ° C., and a weight average molecular weight of 18,000 (resin particle concentration: 40% by weight) ) Was prepared.

-Preparation of amorphous polymer dispersion (4)-
・ Divinyl adipate: 3.2 parts by weight ・ Divinylbenzene: Instead of 0.8 parts by weight ・ Adipic acid divinyl: 3.8 parts by weight ・ Divinylbenzene: Amorphous polymer dispersion except using 0.2 parts by weight An amorphous polymer dispersion (4) was prepared in exactly the same manner as liquid (1). Amorphous polymer dispersion (4) obtained by dispersing resin particles having a volume average particle size of 180 nm, a glass transition point of 59 ° C., and a weight average molecular weight of 18,000 (resin particle concentration: 40% by weight) ) Was prepared.

-Preparation of amorphous polymer dispersion (5)-
・ Divinyl adipate: 3.2 parts by weight ・ Divinylbenzene: 0.8 parts by weight ・ Divinyl adipate: 2.7 parts by weight ・ Amorphous polymer dispersion except that divinylbenzene: 1.3 parts by weight is used Amorphous polymer dispersion (5) was prepared in exactly the same manner as liquid (1). Amorphous polymer dispersion (5) obtained by dispersing resin particles having a volume average particle diameter of 180 nm, a glass transition point of 59 ° C., and a weight average molecular weight of 18,000 (resin particle concentration: 40% by weight) ) Was prepared.

-Preparation of colorant dispersion-
-Cyan pigment (manufactured by Dainichi Seika Co., Ltd., Pigment Blue 15: 3 (copper phthalocyanine)): 1000 parts by weight-Anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd .: Neogen R): 150 parts by weight Ion-exchanged water: 9,000 parts by weight The above is mixed, dissolved, and dispersed for about 1 hour using a high-pressure impact disperser Ultimateizer (manufactured by Sugino Machine Co., Ltd., HJP30006) to disperse the colorant (cyan pigment). Dispersed colorant dispersion (C) was prepared. The average particle diameter of the colorant (cyan pigment) in the colorant dispersion was 0.15 μm, and the colorant particle concentration was 23% by weight.

Example 1
-Production of toner base particles (1)-
Crystalline polyester resin dispersion (1): 600 parts by weight Amorphous polymer dispersion (1): 82.5 parts by weight Colorant dispersion (C): 22.87 parts by weight Nonionic surfactant (IGEPAL CA897): 1.05 weight part The said raw material is put into a 5 L cylindrical stainless steel container, and it disperse-mixes for 30 minutes, applying a shear force at 8,000 rpm by Ultraturrax. Next, 0.14 parts by weight of a 10% nitric acid aqueous solution of polyaluminum chloride as a flocculant began to be dripped to promote preaggregation. When each dispersed particle starts to aggregate, the viscosity of the raw material dispersion itself increases. Therefore, when thickening was started, the above-mentioned aqueous flocculant solution was dropped while confirming the size of the aggregated particle with an optical microscope. At this time, the pH of the raw material dispersion is preferably controlled within the range of 4.2 to 4.5, and the pH is adjusted with 0.3N nitric acid or 1N sodium hydroxide aqueous solution as necessary. When the pH is 4.0 or less, the aggregated particle diameter starts to grow. Therefore, the above range is preferable so that the aggregated particle diameter is not too large. The core was held in the above pH range for about 2 hours to form core aggregated particles. At this time, the volume average particle diameter of the core aggregated particles measured with a Coulter counter [TA-II] type (aperture diameter: 50 μm; manufactured by Beckman-Coulter) was about 2 to 3 μm. Next, 27.5 parts by weight of the amorphous polymer dispersion (1) was additionally added to adhere the amorphous polymer particles to the surface of the core aggregated particles.

  Thereafter, the raw material dispersion was transferred to a polymerization kettle equipped with a stirrer and a thermometer, and started to be heated with a mantle heater to promote the growth of adhered aggregated particles at 40 ° C. Then, granulation is advanced while confirming the size and form of the adhered aggregated particles with an optical microscope and a Coulter counter. When the volume average particle diameter reaches 5.2 μm, the pH is adjusted to fuse the adhered aggregated particles. After raising to 9.0, the temperature was raised to 90 ° C. After confirming that the particles were fused with a microscope, the pH was lowered to 6.5 again while maintaining the temperature at 90 ° C., heating was stopped after 1 hour, and the mixture was allowed to cool. Thereafter, the mixture was sieved with a 45 μm mesh, washed repeatedly with water, and then dried with a vacuum dryer. The volume average particle diameter of the toner base particles (1) granulated as described above was 5.7 μm.

(Quantitative determination of resin composition in toner base particles)
In toner base particles (1), the resin composition of toner base particles prepared using two types of binder resin dispersions was quantified using NMR. Specifically, about 20 mg of toner was weighed into a sample bottle, 1 ml of heavy THF as a solvent was added thereto and dissolved sufficiently, the solution was transferred to an NMR tube, and NMR spectrum measurement was performed. The content of the amorphous polymer was 41 wt%.

-Production of Toner (1)-
Toner base particle (1) was added 1.2 parts by weight of fine titania powder having a volume average particle diameter of 20 nm as an external additive with respect to 100 parts by weight of toner, and mixed with a Henschel mixer to obtain toner (1).

-Production of developer (1)-
A developer (1) was prepared by mixing 5 parts by weight of toner (1) and 100 parts by weight of resin-coated ferrite particles (volume average particle diameter 35 μm).

-Image forming apparatus (1)-
The developer (1) is used instead of the black developer of Docu Center Color 500 manufactured by Fuji Xerox Co., Ltd., the toner (1) is used instead of the black replenisher, and the fixing roll surface temperature at the first copy is 110. An image forming apparatus (1) was modified so as to have a temperature of ° C. Changing the shape of the toner remaining on the photoconductor between the transfer nip and the cleaning blade by turning off the main power during copying in black monochrome mode using an A3 full-face halftone original in an environment of room temperature 22 ° C and humidity 55% RH The rate was measured and found to be 78%.

<Evaluation of toner adhesion and streaky image omission on photoreceptor>
Using the image forming apparatus (1), 5000 copies were made in a black single color mode using a document having an image density of 5% in an environment of room temperature 22 ° C. and humidity 55% RH. After that, one copy was made in the black monochrome mode using the A3 full-page halftone original, and an image quality sample was obtained. The presence or absence of streaky white spots in the image quality sample was visually evaluated. Thereafter, the photoreceptor was taken out, and the presence or absence of toner adhesion on the photoreceptor was visually evaluated.

(Example 2)
Toner base particles (2) were produced in exactly the same manner as toner base particles (1) except that amorphous polymer dispersion (2) was used instead of amorphous polymer dispersion (1). The volume average particle diameter of the granulated toner mother particles (2) was 5.7 μm.

The resin composition in the toner base particles (2) was determined by the same method as in Example 1 and the content of the amorphous polymer was measured. As a result, the content of the amorphous polymer was 45%.
Further, the toner (2), developer (2) and image forming apparatus (2) were obtained in the same manner as in Example 1, and the shape change rate of the toner staying on the photoreceptor was measured, and found to be 62%. It was. In addition, evaluation of toner adhesion and streak image omission on the photoreceptor was performed. The results are shown in Table 1.

(Example 3)
Toner base particles (3) were produced in the same manner as toner base particles (1) except that amorphous polymer dispersion (3) was used instead of amorphous polymer dispersion (1). The volume average particle diameter of the granulated toner base particles (3) was 5.7 μm.

The resin composition in the toner base particles (3) was quantified in the same manner as in Example 1, and the content of the amorphous polymer was measured. As a result, the content of the amorphous polymer was 40%.
Further, the toner (3), developer (3) and image forming apparatus (3) were obtained in the same manner as in Example 1, and the shape change rate of the toner staying on the photoreceptor was measured and found to be 65%. It was. In addition, evaluation of toner adhesion and streak image omission on the photoreceptor was performed. The results are shown in Table 1.

(Comparative Example 1)
Toner base particles (4) were produced in the same manner as toner base particles (1) except that amorphous polymer dispersion (4) was used instead of amorphous polymer dispersion (1). The volume average particle diameter of the granulated toner base particles (4) was 5.7 μm.

The resin composition in the toner base particles (4) was quantified in the same manner as in Example 1, and the content of the amorphous polymer was measured. As a result, the content of the amorphous polymer was 44%.
Further, the toner (4), developer (4) and image forming apparatus (4) were obtained in the same manner as in Example 1, and the shape change rate of the toner remaining on the photosensitive member was measured. It was. In addition, evaluation of toner adhesion and streak image omission on the photoreceptor was performed. The results are shown in Table 1.

(Comparative Example 2)
Toner base particles (5) were produced in the same manner as toner base particles (1), except that amorphous polymer dispersion (5) was used instead of amorphous polymer dispersion (1). The volume average particle diameter of the granulated toner base particles (5) was 5.7 μm.

The resin composition in the toner base particles (5) was determined in the same manner as in Example 1, and the content of the amorphous polymer was measured. As a result, the content of the amorphous polymer was 38%.
Further, the toner (5), developer (5) and image forming apparatus (5) were obtained in the same manner as in Example 1, and the shape change rate of the toner remaining on the photosensitive member was measured and found to be 55%. It was. In addition, evaluation of toner adhesion and streak image omission on the photoreceptor was performed. The results are shown in Table 1.

Example 4
Crystalline polyester resin dispersion (1): 600 parts by weight Amorphous polymer dispersion (1): Instead of 82.5 parts by weight Crystalline polyester resin dispersion (1): 620 parts by weight Amorphous Polymer dispersion (1): Toner base particles (6) were produced in the same manner as toner base particles (1) except that 62 parts by weight were used. The volume average particle diameter of the granulated toner base particles (6) was 5.7 μm.

The resin composition in the toner base particles (6) was quantified by the same method as in Example 1, and the content of the amorphous polymer was measured. As a result, the content of the amorphous polymer was 33%.
Further, the toner (6), developer (6) and image forming apparatus (6) were obtained in the same manner as in Example 1, and the shape change rate of the toner remaining on the photosensitive member was measured. It was. In addition, evaluation of toner adhesion and streak image omission on the photoreceptor was performed. The results are shown in Table 1.

  From the results shown in Table 1, in Examples (1) to (4), there was little toner adhesion on the photoreceptor, and almost no image loss occurred. On the other hand, in Comparative Examples (1) and (2), there was toner adhesion on the photoconductor, so that image omission occurred.

Claims (3)

An electrostatic charge image developing toner containing at least a binder resin,
The binder resin contains crystalline polyester and amorphous polymer,
The amorphous polymer contains an aliphatic cross-linking component A and an aromatic cross-linking component B, and when the content of A is [A] and the content of B is [B],
A toner for developing an electrostatic charge image, wherein 0.1 ≦ [B] / [A] ≦ 0.4.   A developer for developing an electrostatic image, comprising the toner according to claim 1 and a carrier. An electrostatic charge image forming step of forming an electrostatic charge image on the electrostatic charge image carrier;
A developing step of developing the electrostatic charge image with an electrostatic charge image developing developer containing toner to form a toner image;
A transfer step of transferring the toner image onto a transfer target;
A fixing step of fixing the toner image, and an image forming method comprising:
2. The toner according to claim 1, wherein a toner shape change rate (Tt) represented by the following formula (1) of the toner remaining on the photoreceptor after passing through the transfer nip is 60 to 100%: An image forming method using the developer for developing an electrostatic charge image according to claim 2.
Tt = (h / x) × 100 (1)
Here, x represents the maximum length (μm) of the deformed toner particle projected image, and h represents the deformed toner particle projected image formed on a plane perpendicular to the axis in the maximum length direction of the deformed toner particle projected image. Represents the maximum length (μm).