JP4745823B2 - Image forming method - Google Patents

Description

  In the electrophotographic method, the electrostatic latent image formed on an electrostatic latent image carrier such as an electrophotographic photosensitive member or an electrostatic recording derivative is developed with a developer, and the electrostatic latent image carrier is obtained. A development process for forming a toner image thereon, a transfer process for electrostatically transferring the toner image formed on the electrostatic latent image carrier to / from a recording material via / without an intermediate transfer member, The present invention relates to an image forming method including at least a fixing step of fixing a toner image by heating.

  In recent years, there are increasing opportunities for users to output graphic data such as image data and posters captured by digital cameras, digital video cameras, portable terminals, and the like using image forming apparatuses such as digital copying machines and digital LBPs. For this reason, the necessity of outputting an image on the entire surface of paper is increasing as in the development and light printing of a conventional optical film camera. In response to such market needs, proposals have been made to add an image forming function corresponding to a full border to an image forming apparatus (Patent Documents 1 and 2).

  In addition, in order to bring the color and glossiness of the output image closer to that of photographic prints, it has been proposed to limit the thickness, gloss, and strength of the recording material, and to form a full borderless image with no margins by a cutting function or the like. (Patent Document 3). In order to achieve an image quality equivalent to that of film photographs, it is necessary to optimize the toner, recording material, printer, and post-processing process used in the image forming method. There is a wide demand for an image forming method that can output an image corresponding to a full border without adding a post-processing step such as a function.

  Therefore, technical problems related to image formation corresponding to a full border will be described below.

  In the case of image formation corresponding to the entire border, a so-called “rolling offset phenomenon” in which the toner image on the recording material does not separate from the heating member, particularly when a recording material having no margin at the front end enters the fixing nip portion. Tend to occur. This wrapping offset phenomenon is largely due to the characteristics of the toner, and is not yet fully studied in image formation corresponding to the entire borderless area. In the case of a recording material with no margin at the leading edge, the force that pulls the recording material into the fixing nip is directly applied to the toner image, so the toner image at the leading edge is disturbed or the toner is likely to scatter. "Phenomenon" tends to occur. This fixing splatter phenomenon is easily affected by the fluidity of toner and the force for drawing the recording material into the fixing nip, that is, the pressure applied to the fixing nip.

  Further, since it is necessary to form an image larger than the size of the recording material in the transfer portion, the toner tends to wrap around the front, rear, and left and right cut surfaces. Therefore, when the recording material enters the fixing nip portion, in the portion where the recording material of the fixing nip portion does not pass, the toner on the cut surface of the recording material enters the fixing nip portion as it is, such as a heating member or a pressure member. It tends to contaminate the fixing member.

  Therefore, in the case of image formation corresponding to full-frame borders, the above-mentioned phenomenon is a technical problem. Therefore, an image formation method using toner suitable for image formation corresponding to full-frame borders is widely demanded. Yes.

JP 2003-98915 A JP-A-2004-45457 JP 2004-1108020 A

  An object of the present invention is to prevent a winding offset phenomenon in a fixing portion when a recording material having no margin at the front end enters a fixing portion when forming an image having no margin, and to prevent the toner image of the leading end from being formed. It is an object of the present invention to provide an image forming method using toner capable of suppressing fixing scattering phenomenon such as disturbance and toner scattering.

  Another object of the present invention is to suppress the wraparound of toner to the cutting surface of the recording material at the leading edge, the trailing edge, and the right and left edges when forming an image having no borders on the entire surface. An object of the present invention is to provide an image forming method using a toner capable of preventing contamination of a fixing member.

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

The present invention includes a charging step of charging the electrostatic latent image carrier, an electrostatic latent image forming step of forming an electrostatic latent image on the charged electrostatic latent image carrier, and the electrostatic latent image containing toner. Developing with a developer to form a toner image on the electrostatic latent image carrier, a transfer step for electrostatically transferring the toner image formed on the electrostatic latent image carrier to a recording material, and recording In an image forming method having at least a fixing step of fixing a toner image on a material by heating,
i) In the image forming method, a toner image is formed on the electrostatic latent image carrier so that at least one of the main scanning direction and the sub-scanning direction is longer than the length of the recording material, and the toner image is recorded. To be transferred to the material,
ii) The toner has toner particles containing at least a binder resin, a colorant and a release agent, and inorganic fine particles,
The toner particles are obtained by pulverizing a colored resin composition obtained by melt-kneading at least a binder resin, a colorant, and a release agent.
The toner is
a) Storage elastic modulus G ′ (140 ° C.) at 140 ° C. of 1.0 × 10 ³ dN / m ² or more and less than 1.0 × 10 ⁵ dN / m ² b) UV transmittance of 45 to 45 % MeOH aqueous solution is 31 to 61 %
c) Compression degree C obtained from the following formula (1) is 38 to 56%.
Compression degree C (%) = 100 × (PA) / P (1)
(In the formula, A is the loose apparent density (g / cm ³ ), and P is the firm apparent density (g / cm ³ ).)
The present invention relates to an image forming method.

  The present invention also relates to the image forming method, wherein the toner has an average circularity of 0.920 to 0.970.

  The present invention also relates to the image forming method, wherein the toner contains a polyester unit as a main component of the binder resin.

  The present invention also relates to the image forming method, wherein the fixing pressure in the fixing step is 0.03 to 0.30 MPa.

  According to the present invention, in the image forming method according to claim 1, the fixing nip portion is formed when a recording material having no margin at the front end enters the fixing nip portion when an image having no margin is formed. In addition to preventing the winding offset phenomenon in the toner image, it is possible to suppress the fixing scattering phenomenon such as the disturbance of the toner image at the front end and the toner scattering. Further, when the recording materials have different thicknesses, there is an effect that the winding offset phenomenon particularly in thin paper can be suppressed.

Further, according to the present invention, the image forming method according to claim 1 and / or claim 2 , wherein when the image having no border is formed, the toner wraps around the cut surface of the recording material at the transfer portion. In the fixing nip area, especially when a recording material with no margin at the front end enters the fixing section, the fixing scattering phenomenon such as toner image disturbance or toner scattering at the leading end occurs. Can be further suppressed.

According to the present invention, the image forming method according to claim 3 further suppresses the winding offset phenomenon and the fixing splatter phenomenon by the fixing characteristics of the toner using the binder resin containing at least the polyester unit. It has the effect of being able to.

According to the present invention, the image forming method according to claim 4 can reduce the force for drawing the recording material into the fixing nip portion, and the fixing scattering phenomenon can be prevented regardless of the type of the recording material. Further, it is possible to further suppress the contamination and to further suppress the contamination of the fixing member.

  Hereinafter, the best mode for carrying out the present invention will be described in detail.

  First, the physical properties of the toner used in the image forming method of the present invention will be described in detail.

<Toner physical properties>
The toner used in the image forming apparatus of the present invention has toner particles and inorganic fine particles containing at least a binder resin, a colorant and a release agent,
a) Storage elastic modulus G ′ (140 ° C.) at 140 ° C. is 1.0 × 10 ³ dN / m ² or more and less than 1.0 × 10 ⁵ dN / m ² b) UV transmittance with respect to 40% MeOH aqueous solution is 10 to 10%. 80%
Thus, the problem of the present invention is solved.

Specifically, since the storage elastic modulus G ′ (140 ° C.) of the toner is viscoelasticity of 1.0 × 10 ³ dN / m ² or more and less than 1.0 × 10 ⁵ dN / m ² , When forming a no-image, a winding offset phenomenon when a recording material having no margin at the front end enters the fixing nip portion is effectively suppressed. The storage elastic modulus G ′ is an index representing elasticity in a polymer, that is, a reversible property with respect to stress. The storage elastic modulus G ′ of the toner represents a force for restoring the original state when the toner is deformed by heat and pressure in the fixing nip portion. In other words, it indicates whether the molecule forming the toner has a spring-like property. Further, the temperature of 140 ° C. in calculating the storage elastic modulus G ′ of the toner does not necessarily coincide with the fixing setting temperature. For example, the fixing setting temperature is set to 200 ° C., the fixing pressure is 0.10 MPa, and the recording material When the residence time at the fixing nip is 100 msec, the temperature measurement result on the recording material with the thermocouple attached is 140 ° C.

When the storage elastic modulus G ′ (140 ° C.) of the toner is less than 1.0 × 10 ³ dN / m ² , the elasticity of the toner is reduced and the winding offset around the heating member is deteriorated. On the other hand, when the storage elastic modulus G ′ (140 ° C.) is 1.0 × 10 ⁵ dN / m ² or more, it takes a long time to melt by receiving heat from the heating member in the fixing nip. Contamination of the fixing member with toner that does not melt completely deteriorates.

In addition, as a characteristic of the toner in the fixing nip portion, releasability with respect to the fixing member is important. Therefore, when the storage elastic modulus G ′ (140 ° C.) of the toner is in the above range and the UV transmittance of the toner with respect to the 45 % MeOH aqueous solution is 10 to 80%, the toner starts to melt. In addition, the release agent contained in the toner is likely to exude to the surface of the toner particles, the release agent is lubricated between the toner particles, and the release action between the toner layer and the heating member is further improved. The offset phenomenon can be further suppressed. Furthermore, by controlling the exudation of the release agent contained in the toner to the surface of the toner particles, it is possible to control the time until the toner is melted by receiving heat from the heating member in the fixing nip. It has a synergistic effect that can suppress fixing scattering phenomenon such as toner disturbance and toner scattering.

When the UV transmittance of the toner with respect to the 45 % MeOH aqueous solution is less than 10%, the winding offset around the heating member is deteriorated. When the UV transmittance exceeds 80%, the fluidity as a toner deteriorates, and the toner may be fused to the photosensitive member or the transfer member may be contaminated in the development process or the transfer process.

  The toner used in the image forming method of the present invention preferably has an average circularity of 0.920 to 0.970. When the average circularity of the toner is 0.920 to 0.970, the toner can be prevented from wrapping around the cut surface of the recording material at the transfer portion, and contamination of the fixing member can be suppressed. Further, in the fixing nip portion, it is possible to further suppress the fixing scattering phenomenon such as the disturbance of the toner image at the leading end portion and the toner scattering when a recording material having no margin at the leading end enters the fixing portion.

  When the average circularity of the toner exceeds 0.970, the toner approaches a true sphere at the transfer portion, so that the contact area with the recording material is reduced, and the toner on the recording material end surface tends to wrap around the cut surface. Tend to promote. Further, when a recording material having no margin at the tip enters the fixing nip portion, the toner image tends to be disturbed or scattered. On the other hand, when the average circularity of the toner is less than 0.920, the contact area between the toner and the electrophotographic member increases, adhesion to the electrophotographic member due to the mirror force increases, In some cases, missing dots (so-called voids) may occur due to defective transfer in the transfer process.

The toner used in the image forming method of the present invention preferably has a degree of compression C obtained from the following formula (1) of 30 to 60%.
Compression degree C (%) = 100 × (PA) / P (1)
(In the formula, A is the loose apparent density (g / cm ³ ), and P is the firm apparent density (g / cm ³ ).)

  When the toner compression degree C is 30 to 60%, the wraparound of the end face of the recording material to the cut surface of the toner at the time of transfer can be suppressed and contamination of the fixing member can be suppressed. Further, when a recording material having no margin at the leading end enters the fixing nip portion, it is possible to suppress the toner image disturbance and toner scattering at the leading end portion of the toner layer. When the toner compression degree C is less than 30%, the toner tends to scatter during the transfer, so that the toner on the end face of the recording material tends to wrap around the cut surface and promotes contamination of the fixing member. . Further, when a recording material having no margin at the tip enters the fixing nip portion, the toner image tends to be disturbed or scattered. If the toner compression degree C exceeds 60%, the toner image on the recording material may be disturbed by the shearing force of the transfer member during transfer, and an image having excellent dot reproducibility may not be obtained.

  The toner used for the image forming method of the present invention preferably contains at least a polyester unit as a main component of the binder resin. A resin having at least a polyester unit has excellent performance in low-temperature fixability. For this reason, when forming an image corresponding to the entire borderless area, the toner layer needs to be easily melted when a recording material having no margin at the tip enters the fixing nip portion.

  Conventionally, vinyl copolymers such as polyester resins and styrene resins are mainly used as binder resins for toners. Polyester resins have excellent low-temperature fixability, but are said to have the disadvantage that they tend to cause an offset phenomenon at high temperatures. In order to compensate for this drawback, attempts have been made to improve the viscoelastic properties by increasing the molecular weight of the polyester resin. In this case, however, the low-temperature fixability tends to be impaired. In addition, the pulverizability at the time of toner production is also deteriorated, resulting in a binder resin that is not suitable for toner fine particles.

  On the other hand, vinyl copolymers such as styrene resins are excellent in high temperature offset resistance because they are excellent in pulverization during the production of toner and can be easily increased in molecular weight. However, when the molecular weight is lowered or the glass transition temperature is lowered in order to improve the low-temperature fixability, there is a tendency that the blocking resistance and developability deteriorate.

  Therefore, in the present invention, those obtained by mixing and / or hybridizing these resins in order to effectively utilize the advantages of these two kinds of resins and compensate for the disadvantages are more preferably used.

  Next, the material structure of the toner used in the present invention will be described in detail.

<Toner material composition>
As the binder resin that can be used in the present invention, known resins can be used. As described above, it is preferable to contain a polyester unit as the main component of the binder resin. The binder resin preferably used includes (a) a polyester resin, (b) a hybrid resin having a polyester unit and a vinyl copolymer unit, and (c) a mixture of the hybrid resin and the vinyl copolymer. , (D) a mixture of a polyester resin and a vinyl copolymer, (e) a mixture of a hybrid resin and a polyester resin, and (f) a mixture of a polyester resin, a hybrid resin, and a vinyl copolymer. Resin.

  By adjusting the molecular weight distribution of the resins (a) to (f), the viscoelasticity of the toner used in the image forming method of the present invention can be achieved.

  When a polyester resin is used as the binder resin, a polyhydric alcohol, a polyvalent carboxylic acid, a polyvalent carboxylic acid anhydride, a polyvalent carboxylic acid ester, or the like can be used as a raw material monomer. The same applies to the monomers used for producing the polyester unit in the hybrid resin.

  Specifically, for example, as the dihydric alcohol component, polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene (3.3) -2,2-bis ( 4-hydroxyphenyl) propane, polyoxyethylene (2.0) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene (2.0) -polyoxyethylene (2.0) -2,2 -Alkylene oxide adducts of bisphenol A such as bis (4-hydroxyphenyl) propane, polyoxypropylene (6) -2,2-bis (4-hydroxyphenyl) propane, ethylene glycol, diethylene glycol, triethylene glycol, 1, 2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, Opentyl glycol, 1,4-butenediol, 1,5-pentanediol, 1,6-hexanediol, 1,4-cyclohexanedimethanol, dipropylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, bisphenol A And hydrogenated bisphenol A.

  Examples of the trivalent or higher alcohol component include sorbitol, 1,2,3,6-hexanetetrol, 1,4-sorbitan, pentaerythritol, dipentaerythritol, tripentaerythritol, 1,2,4-butanetriol, 1,2,5-pentanetriol, glycerol, 2-methylpropanetriol, 2-methyl-1,2,4-butanetriol, trimethylolethane, trimethylolpropane, 1,3,5-trihydroxymethylbenzene, etc. Can be mentioned.

  Divalent acid components include aromatic dicarboxylic acids such as phthalic acid, isophthalic acid and terephthalic acid or anhydrides; alkyl dicarboxylic acids such as succinic acid, adipic acid, sebacic acid and azelaic acid or anhydrides; Succinic acid substituted with 6 to 12 alkyl groups or anhydrides thereof; unsaturated dicarboxylic acids such as fumaric acid, maleic acid and citraconic acid or anhydrides thereof.

  Examples of the trivalent or higher polyvalent carboxylic acid component for forming a polyester resin having a crosslinking site include 1,2,4-benzenetricarboxylic acid, 1,2,5-benzenetricarboxylic acid, 1,2 , 4-Naphthalenetricarboxylic acid, 2,5,7-naphthalenetricarboxylic acid, 1,2,4,5-benzenetetracarboxylic acid, and anhydrides and ester compounds thereof.

  Among them, in particular, a bisphenol derivative represented by the following general formula (I) is used as a diol component, and a carboxylic acid component (for example, fumaric acid) composed of a divalent or higher carboxylic acid or an acid anhydride thereof, or a lower alkyl ester thereof. A polyester resin obtained by polycondensation using acid, maleic acid, maleic anhydride, phthalic acid, terephthalic acid, trimellitic acid, pyromellitic acid, etc.) as an acid component is preferable because it has good charging characteristics as a color toner. .

  In the binder resin contained in the toner that can be used in the present invention, the “hybrid resin” means a resin in which a vinyl polymer unit and a polyester unit are chemically bonded. Specifically, it is a resin formed by a transesterification reaction between a polyester unit and a vinyl polymer unit obtained by polymerizing a monomer having a carboxylic acid ester group such as (meth) acrylic acid ester, preferably a vinyl polymer. A graft copolymer (or block copolymer) having a trunk polymer and a polyester unit as a branch polymer. In the present invention, “polyester unit” refers to a portion derived from polyester, and “vinyl polymer unit” refers to a portion derived from a vinyl polymer. The polyester monomer constituting the polyester unit is a polyvalent carboxylic acid component and a polyhydric alcohol component, and the vinyl polymer unit is a monomer component having a vinyl group.

  Examples of vinyl monomers for producing vinyl copolymers or vinyl polymer units include styrene; o-methyl styrene, m-methyl styrene, p-methyl styrene, α-methyl styrene, p-phenyl styrene, p. -Ethyl styrene, 2,4-dimethyl styrene, pn-butyl styrene, p-tert-butyl styrene, pn-hexyl styrene, pn-octyl styrene, pn-nonyl styrene, pn- Styrene such as decylstyrene, pn-dodecylstyrene, p-methoxystyrene, p-chlorostyrene, 3,4-dichlorostyrene, m-nitrostyrene, o-nitrostyrene, p-nitrostyrene and derivatives thereof; ethylene , Styrene unsaturated monoolefins such as propylene, butylene and isobutylene; Unsaturated polyenes such as ene and isoprene; vinyl halides such as vinyl chloride, vinylidene chloride, vinyl bromide and vinyl fluoride; vinyl esters such as vinyl acetate, vinyl propionate and vinyl benzoate; methyl methacrylate; Ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-octyl methacrylate, dodecyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, phenyl methacrylate, dimethylaminoethyl methacrylate, Α-methylene aliphatic monocarboxylic acid esters such as diethylaminoethyl methacrylate; methyl acrylate, ethyl acrylate, propyl acrylate, acrylic acid-n-butyl, acrylic acid isobutyl, acrylic acid-n-o Acrylic acid esters such as chill, dodecyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, 2-chloroethyl acrylate, phenyl acrylate; vinyl ethers such as vinyl methyl ether, vinyl ethyl ether, vinyl isobutyl ether; Vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone and methyl isopropenyl ketone; N-vinyl compounds such as N-vinyl pyrrole, N-vinyl carbazole, N-vinyl indole and N-vinyl pyrrolidone; vinyl naphthalenes; acrylonitrile, methacrylate Examples thereof include acrylic acid or methacrylic acid derivatives such as nitrile and acrylamide.

  In addition, unsaturated dibasic acids such as maleic acid, citraconic acid, itaconic acid, alkenyl succinic acid, fumaric acid, mesaconic acid; maleic anhydride, citraconic anhydride, itaconic anhydride, alkenyl succinic anhydride, etc. Unsaturated dibasic acid anhydride; maleic acid methyl half ester, maleic acid ethyl half ester, maleic acid butyl half ester, citraconic acid methyl half ester, citraconic acid ethyl half ester, citraconic acid butyl half ester, itaconic acid methyl half ester, Alkenyl succinic acid half ester, fumaric acid methyl half ester, mesaconic acid methyl half ester unsaturated dibasic acid half ester; dimethylmaleic acid, dimethyl fumaric acid unsaturated dibasic acid ester; acrylic acid, meta Α, β-unsaturated acids such as rillic acid, crotonic acid and cinnamic acid; α, β-unsaturated acid anhydrides such as crotonic acid anhydride and cinnamic anhydride, the α, β-unsaturated acid and lower fatty acids And monomers having a carboxyl group such as alkenylmalonic acid, alkenylglutaric acid, alkenyladipic acid, acid anhydrides and monoesters thereof.

  Further, acrylic acid or methacrylic acid esters such as 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate; 4- (1-hydroxy-1-methylbutyl) styrene, 4- (1-hydroxy-1) -Methylhexyl) Monomers having a hydroxy group such as styrene.

  In the toner that can be used in the present invention, the vinyl copolymer or vinyl polymer unit of the binder resin may have a crosslinked structure crosslinked with a crosslinking agent having two or more vinyl groups. Examples of the crosslinking agent used in this case include aromatic divinyl compounds such as divinylbenzene and divinylnaphthalene; examples of diacrylate compounds linked by an alkyl chain include ethylene glycol diacrylate and 1,3-butylene glycol. Examples include diacrylate, 1,4-butanediol diacrylate, 1,5-pentanediol diacrylate, 1,6-hexanediol diacrylate, neopentyl glycol diacrylate, and those obtained by replacing acrylates of the above compounds with methacrylate. The diacrylate compounds linked by an alkyl chain containing an ether bond include, for example, diethylene glycol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, poly Examples include tylene glycol # 400 diacrylate, polyethylene glycol # 600 diacrylate, dipropylene glycol diacrylate, and those obtained by replacing acrylates of the above compounds with methacrylates; diacrylates linked by a chain containing an aromatic group and an ether bond. Examples of the compounds include polyoxyethylene (2) -2,2-bis (4-hydroxyphenyl) propane diacrylate, polyoxyethylene (4) -2,2-bis (4-hydroxyphenyl) propane diacrylate and the like The thing which replaced the acrylate of the compound of this with the methacrylate is mentioned.

  Polyfunctional cross-linking agents include pentaerythritol triacrylate, trimethylol ethane triacrylate, trimethylol propane triacrylate, tetramethylol methane tetraacrylate, oligoester acrylate, and acrylates of the above compounds replaced with methacrylate; triallylcia Examples include nurate and triallyl trimellitate.

  When producing the hybrid resin, it is preferable that a monomer component capable of reacting with the components of both resin units is contained in one or both of the vinyl polymer unit and the polyester unit. Examples of monomers that can react with the components of the vinyl polymer unit among the monomers constituting the polyester resin unit include unsaturated dicarboxylic acids such as phthalic acid, maleic acid, citraconic acid, and itaconic acid, or anhydrides thereof. It is done. Among the monomers constituting the vinyl polymer unit, those capable of reacting with the components of the polyester unit include those having a carboxyl group or a hydroxy group, and acrylic acid or methacrylic acid esters.

  As a method of obtaining a reaction product of a vinyl polymer unit and a polyester unit, there is a polymer containing a monomer component capable of reacting with each of the vinyl polymer unit and the polyester unit listed above. A method obtained by carrying out the polymerization reaction of one or both resins is preferred.

  Examples of the polymerization initiator used for producing the vinyl copolymer or vinyl polymer unit usable in the present invention include 2,2′-azobisisobutyronitrile, 2,2′-azobis ( 4-methoxy-2,4-dimethylvaleronitrile), 2,2′-azobis (-2,4-dimethylvaleronitrile), 2,2′-azobis (-2methylbutyronitrile), dimethyl-2,2 '-Azobisisobutyrate, 1,1'-azobis (1-cyclohexanecarbonitrile), 2- (carbamoylazo) -isobutyronitrile, 2,2'-azobis (2,4,4-trimethylpentane), 2-phenylazo-2,4-dimethyl-4-methoxyvaleronitrile, 2,2'-azobis (2-methyl-propane), methyl ethyl ketone peroxide Ketone peroxides such as acetylacetone peroxide and cyclohexanone peroxide, 2,2-bis (t-butylperoxy) butane, t-butyl hydroperoxide, cumene hydroperoxide, 1,1,3,3-tetramethyl Butyl hydroperoxide, di-t-butyl peroxide, t-butylcumyl peroxide, di-cumyl peroxide, α, α'-bis (t-butylperoxyisopropyl) benzene, isobutyl peroxide, octanoyl peroxide Decanoyl peroxide, lauroyl peroxide, 3,5,5-trimethylhexanoyl peroxide, benzoyl peroxide, m-trioyl peroxide, di-isopropyl peroxydicarbonate, di-2 Ethyl hexyl peroxydicarbonate, di-n-propyl peroxydicarbonate, di-2-ethoxyethyl peroxycarbonate, di-methoxyisopropyl peroxydicarbonate, di (3-methyl-3-methoxybutyl) peroxycarbonate, Acetylcyclohexylsulfonyl peroxide, t-butylperoxyacetate, t-butylperoxyisobutyrate, t-butylperoxyneodecanoate, t-butylperoxy 2-ethylhexanoate, t-butylperoxylaur Rate, t-butyl peroxybenzoate, t-butyl peroxyisopropyl carbonate, di-t-butyl peroxyisophthalate, t-butyl peroxyallyl carbonate, t-amyl peroxy 2-ethylhexyl Noeto, di -t- butyl peroxy hexahydro terephthalate, di -t- butyl peroxy azelate and the like.

  Examples of the production method for preparing the hybrid resin used in the toner that can be used in the present invention include the production methods shown in the following (1) to (5).

  (1) After separately producing a vinyl polymer and a polyester resin, dissolve and swell in a small amount of an organic solvent, add an esterification catalyst and an alcohol, and heat to synthesize a hybrid resin. Method.

  (2) A method for producing a polyester unit and a hybrid resin component in the presence of a vinyl polymer after the production thereof. The hybrid resin component is added as necessary to the reaction of a vinyl polymer unit (a vinyl monomer can be added if necessary) and a polyester monomer (polyhydric alcohol, polycarboxylic acid), and the unit and monomer as necessary. Produced by reaction with polyester. Also in this case, an organic solvent can be appropriately used.

  (3) A method for producing a vinyl polymer unit and a hybrid resin component in the presence of a polyester resin after the production. The hybrid resin component is produced by a reaction between a polyester unit (a polyester monomer can be added if necessary) and a vinyl monomer, and a reaction between the unit and the monomer and a vinyl polymer unit added as necessary. . Also in this case, an organic solvent can be appropriately used.

  (4) After the vinyl polymer and the polyester resin are produced, either or both of a vinyl monomer and a polyester monomer (polyhydric alcohol, polycarboxylic acid) are added in the presence of these polymer units, and the added monomer. The hybrid resin component can be produced by carrying out a polymerization reaction under conditions according to the conditions. Also in this case, an organic solvent can be appropriately used.

  (5) By mixing a vinyl monomer and a polyester monomer (polyhydric alcohol, polycarboxylic acid, etc.) and continuously performing addition polymerization and condensation polymerization reaction, a vinyl polymer unit, a polyester unit, and a hybrid resin component are obtained. Manufactured. Furthermore, an organic solvent can be used as appropriate.

  In the production methods (1) to (5), a plurality of polymer units having different molecular weights and different degrees of crosslinking can be used for the vinyl polymer unit and the polyester unit.

  The vinyl polymer or vinyl polymer unit in the present invention means a vinyl homopolymer or vinyl copolymer, a vinyl monopolymer unit or a vinyl copolymer unit.

  Furthermore, the molecular weight distribution measured by gel permeation chromatography (GPC) of a resin having a polyester unit that can be used in the present invention has a main peak in the region of molecular weight 3,500 to 15,000, Preferably, it has a molecular weight of 4,000 to 13,000, and Mw / Mn is preferably 3.0 or more, more preferably 5.0 or more. When the main peak is in a region having a molecular weight of less than 3,500, the high temperature offset resistance of the toner decreases. On the other hand, when the main peak is in a region having a molecular weight of more than 15000, sufficient low-temperature fixability of the toner and OHP permeability are deteriorated. Moreover, when Mw / Mn is less than 3.0, good offset resistance is reduced.

  The toner that can be used in the present invention preferably contains a wax as a release agent from the viewpoint of improving the fixability.

  Examples of the wax that can be used in the present invention include the following. Oxides of aliphatic hydrocarbon waxes such as low molecular weight polyethylene, low molecular weight polypropylene, alkylene copolymers, microcrystalline wax, paraffin wax, Fischer-Tropsch wax, and aliphatic hydrocarbon waxes such as oxidized polyethylene wax, or the like Block copolymers of these: waxes mainly composed of fatty acid esters such as carnauba wax, behenyl behenate, and montanic acid ester wax, and those obtained by partially or fully deoxidizing fatty acid esters such as deoxidized carnauba wax Is mentioned. Further, saturated linear fatty acids such as palmitic acid, stearic acid, and montanic acid; unsaturated fatty acids such as brassic acid, eleostearic acid, and valinalic acid; stearyl alcohol, aralkyl alcohol, behenyl alcohol, carnauvyl alcohol, and seryl alcohol Saturated alcohols such as melyl alcohol; polyhydric alcohols such as sorbitol; fatty acids such as palmitic acid, stearic acid, behenic acid, and montanic acid; and stearyl alcohol, aralkyl alcohol, behenyl alcohol, carnauvir alcohol, seryl alcohol, Esters of alcohols such as merisyl alcohol; fatty acid amides such as linoleic acid amide, oleic acid amide, lauric acid amide; methylene bis stearic acid amide, ethylene biscapric acid Saturated fatty acid bisamides such as amide, ethylene bislauric acid amide, hexamethylene bis stearic acid amide; ethylene bis oleic acid amide, hexamethylene bis oleic acid amide, N, N ′ dioleyl adipic acid amide, N, N ′ dioleyl Unsaturated fatty acid amides such as sebacic acid amides; Aromatic bisamides such as m-xylene bisstearic acid amide and N, N ′ distearyl isophthalic acid amides; calcium stearate, calcium laurate, zinc stearate, magnesium stearate, etc. Aliphatic metal salts (generally referred to as metal soaps); waxes grafted with aliphatic hydrocarbon waxes using vinyl monomers such as styrene and acrylic acid; fatty acids such as behenic acid monoglycerides and many others Price Lumpur partial ester; methyl ester compounds having hydroxyl groups obtained by and hydrogenated vegetable oils and the like.

  Examples of the wax that can be particularly preferably used in the present invention include aliphatic hydrocarbon waxes and esterified products that are esters of fatty acids and alcohols. For example, low molecular weight alkylene polymer obtained by radical polymerization of alkylene under high pressure with Ziegler catalyst or metallocene catalyst under low pressure; alkylene polymer obtained by thermally decomposing high molecular weight alkylene polymer; synthesis containing carbon monoxide and hydrogen A synthetic hydrocarbon wax obtained from the distillation residue of hydrocarbons obtained from the gas by the age method or by hydrogenating them is preferred. Further, those obtained by fractionating hydrocarbon wax by press sweating, solvent method, vacuum distillation or fractional crystallization are more preferably used. The hydrocarbon as a base is synthesized by the reaction of carbon monoxide and hydrogen using a metal oxide catalyst (mostly two or more multi-component systems) [for example, the Jintol method, the Hydrocol method (the fluidized catalyst bed Hydrocarbon compounds synthesized by use); hydrocarbons with up to several hundred carbon atoms obtained by the age method (using the identified catalyst bed) from which a large amount of wax-like hydrocarbons can be obtained; alkylene such as ethylene by Ziegler catalyst Polymerized hydrocarbons are preferred because they are linear hydrocarbons with little branching, small and long saturation. In particular, a wax synthesized by a method that does not rely on polymerization of alkylene is also preferred from its molecular weight distribution. Paraffin wax is also preferably used.

  The wax that can be used in the present invention preferably has a peak temperature of the maximum endothermic peak in the range of 30 to 200 ° C. in the endothermic curve in differential scanning calorimetry (DSC). . More preferably, it is in the range of 65 to 125 ° C, and particularly preferably in the range of 65 to 110 ° C. When the maximum endothermic peak is less than 60 ° C., the blocking resistance of the toner deteriorates. Conversely, when the maximum endothermic peak exceeds 130 ° C., the fixability tends to deteriorate.

  As the colorant used in the toner that can be used in the present invention, known dyes and / or pigments are used. Although the pigment alone may be used, it is more preferable from the viewpoint of the image quality of the full-color image that the combination of the dye and the pigment improves the sharpness.

  Examples of the coloring pigment for magenta toner include condensed azo compounds, diketopyrrolopyrrole compounds, anthraquinones, quinacridone compounds, basic dye lake compounds, naphthol compounds, benzimidazolone compounds, thioindigo compounds, and perlin compounds. Specifically, C.I. I. Pigment Red 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 21, 22, 23, 30, 31, 32, 37, 38, 39, 40, 41, 48: 2, 48: 3, 48: 4, 49, 50, 51, 52, 53, 54, 55, 57: 1, 58, 60, 63, 64, 68, 81: 1, 83, 87, 88, 89, 90, 112, 114, 122, 123, 144, 146, 150, 163, 166, 169, 177, 184, 185, 202, 206, 207, 209, 220, 221, 254, C.I. I. Pigment violet 19, C.I. I. Bat red 1, 2, 10, 13, 15, 23, 29, 35, etc. are mentioned.

  Examples of the magenta toner dye include C.I. I. Solvent Red 1, 3, 8, 23, 24, 25, 27, 30, 49, 81, 82, 83, 84, 100, 109, 121, C.I. I. Disper thread 9, C.I. I. Solvent Violet 8, 13, 14, 21, 27, C.I. I. Oil-soluble dyes such as Disper Violet 1, C.I. I. Basic Red 1, 2, 9, 12, 13, 14, 15, 17, 18, 22, 23, 24, 27, 29, 32, 34, 35, 36, 37, 38, 39, 40, C.I. I. Basic dyes such as basic violet 1, 3, 7, 10, 14, 15, 21, 25, 26, 27, and 28 may be mentioned.

  Examples of the color pigment for cyan toner include C.I. I. Pigment Blue 1, 2, 3, 7, 15: 2, 15: 3, 15: 4, 16, 17, 60, 62, 66; I. Bat Blue 6, C.I. I. Examples include Acid Blue 45 or a copper phthalocyanine pigment in which 1 to 5 phthalimidomethyl groups are substituted on a phthalocyanine skeleton having a structure represented by the following formula (B).

  Examples of the colored pigment for yellow include condensed azo compounds, isoindolinone compounds, anthraquinone compounds, azo metal compounds, methine compounds, and allylamide compounds. Specifically, C.I. I. Pigment Yellow 1, 2, 3, 4, 5, 6, 7, 10, 11, 12, 13, 14, 15, 16, 17, 23, 62, 65, 73, 74, 83, 93, 95, 97, 109, 110, 111, 120, 127, 128, 129, 147, 155, 168, 174, 180, 181, 185, 191, C.I. I. Bat yellow 1, 3, 20 and the like. In addition, C.I. I. Direct Green 6, C.I. I. Basic Green 4, C.I. I. Dyes such as Basic Green 6 and Solvent Yellow 162 can also be used.

  As the black colorant that can be used in the present invention, carbon black, iron oxide particles, and those that are toned in black using the yellow / magenta / cyan colorant shown above can be used.

  In addition, in the toner that can be used in the present invention, it is preferable to use a toner obtained by mixing a colorant in advance with the binder resin of the present invention into a master batch. Then, the colorant can be favorably dispersed in the toner by melt-kneading this colorant master batch and other raw materials (binder resin, wax, etc.).

  When a masterbatch is formed using a resin and a colorant that can be used in the present invention, the dispersibility of the colorant does not deteriorate even when a large amount of the colorant is used, and the colorant in the toner particles does not deteriorate. Dispersibility is improved, and color reproducibility such as color mixing and transparency when an image is formed by fixing a plurality of color toners is excellent. Further, a toner having a large covering power on the transfer material can be obtained by making a master batch. Further, by improving the dispersibility of the colorant by making the masterbatch, it is possible to obtain an image having excellent durability stability of the toner charging property and maintaining high image quality.

  The amount of the colorant used in the toner is preferably 0.1 to 15 parts by mass, more preferably 0.5 to 12 parts by mass, and most preferably 2 to 10 parts by mass with respect to 100 parts by mass of the binder resin. This is preferable in terms of color reproducibility and developability.

  A known charge control agent can be used for the toner that can be used in the present invention in order to stabilize the chargeability. The charge control agent varies depending on the type of charge control agent and the physical properties of other toner particle constituent materials, but generally 0.1 to 10 parts by mass per 100 parts by mass of the binder resin is preferably contained in the toner particles. More preferably, 0.1 to 5 parts by mass are contained. As such a charge control agent, there are known one that controls the toner to be negatively charged and one that controls the toner to be positively charged. One or two kinds of various kinds of charge control agents are used depending on the kind and use of the toner. The above can be used.

  Negatively chargeable charge control agents include salicylic acid metal compounds, naphthoic acid metal compounds, dicarboxylic acid metal compounds, polymer compounds having sulfonic acid or carboxylic acid in the side chain, boron compounds, urea compounds, silicon compounds, calixarene Etc. are available. As the positively chargeable charge control agent, a quaternary ammonium salt, a polymer compound having the quaternary ammonium salt in the side chain, a guanidine compound, an imidazole compound, or the like can be used. The charge control agent may be added internally or externally to the toner particles.

  In particular, the color toner that can be used in the present invention is preferably an aromatic carboxylic acid metal compound that is colorless, has a high toner charging speed, and can stably maintain a constant charge amount.

  The toner that can be used in the present invention is preferably used after adjusting the fluidity of the toner by mixing inorganic fine particles with a mixer such as a Henschel mixer after pulverization and classification or after surface modification.

  Examples of the inorganic fine powder that can be used in the present invention include fluorine resin powders such as vinylidene fluoride fine powder and polytetrafluoroethylene fine powder, titanium oxide fine powder, alumina fine powder, wet process silica, and dry process silica. There are fine powdered silica, treated silica obtained by subjecting them to surface treatment with a silane compound, an organosilicon compound, a titanium coupling agent, silicone oil and the like. Among these, wet process silica, dry process silica, titanium oxide fine powder, alumina fine powder and the like are particularly preferably used.

  As a wet process silica, in particular, a sol-gel method in which a solvent is removed from a silica sol suspension obtained by hydrolysis and condensation reaction with a catalyst in an organic solvent in which water is present, and then dried to form particles. There are silica particles that are produced. The silica particles produced by the sol-gel method preferably have a sharp particle size distribution, and spherical particles can be obtained, and particles having a desired particle size distribution can be obtained by changing the reaction time.

The dry process silica is a fine powder produced by vapor phase oxidation of a silicon halogen compound, which is called so-called dry process silica or fumed silica, and is manufactured by a conventionally known technique. . For example, a thermal decomposition oxidation reaction of silicon tetrachloride gas in an oxyhydrogen flame is used, and the basic reaction formula is as follows.
SiCl ₄ + 2H ₂ + O ₂ → SiO ₂ + 4HCl

  In this production process, it is also possible to obtain a composite fine powder of silica and other metal oxides by using other metal halogen compounds such as aluminum chloride or titanium chloride together with silicon halogen compounds. .

  In the case of titanium oxide fine powder, fine particles of titanium oxide obtained by low-temperature oxidation (thermal decomposition, hydrolysis) of sulfuric acid method, chlorine method, volatile titanium compounds such as titanium alkoxide, titanium halide, titanium acetylacetonate are used. . As the crystal system, any of anatase type, rutile type, mixed crystal type thereof, and amorphous type can be used.

  And if it is alumina fine powder, buyer method, improved buyer method, ethylene chlorohydrin method, underwater spark discharge method, organoaluminum hydrolysis method, aluminum alum pyrolysis method, ammonium aluminum carbonate pyrolysis method, aluminum chloride flame Alumina fine powder obtained by a decomposition method is used. As the crystal system, α, β, γ, δ, ξ, η, θ, κ, χ, ρ type, mixed crystal type, amorphous type, α, δ, γ, θ, mixed crystal can be used. A mold or an amorphous material is preferably used.

  As a method for hydrophobizing the inorganic fine powder, it is applied by chemical or physical treatment with an organosilicon compound that reacts or physically adsorbs with the inorganic fine powder.

  As a preferred method, silica fine powder produced by vapor phase oxidation of a silicon halogen compound is treated with an organosilicon compound. Examples of such organosilicon compounds are hexamethyldisilazane, trimethylsilane, trimethylchlorosilane, trimethylethoxysilane, dimethyldichlorosilane, methyltrichlorosilane, allyldimethylchlorosilane, allylphenyldichlorosilane, benzyldimethylchlorosilane. , Bromomethyldimethylchlorosilane, α-chloroethyltrichlorosilane, β-chloroethyltrichlorosilane, chloromethyldimethylchlorosilane, triorganosilylmercaptan, trimethylsilylmercaptan, triorganosilylacrylate, vinyldimethylacetoxysilane, dimethylethoxysilane, dimethyl Dimethoxysilane, diphenyldiethoxysilane, hexamethyldisiloxane, 1,3-divinyltetramethyldisiloxane 1,3-diphenyltetramethyldisiloxane, and dimethylpolysiloxane containing 2 to 12 siloxane units per molecule and containing hydroxyl groups bonded to one Si at each terminal unit. These are used alone or in a mixture of two or more.

  As inorganic fine particles that can be used in the present invention, the above-described wet process silica or dry process silica treated with a coupling agent having an amino group or silicone oil is used as necessary to achieve the object of the present invention. It doesn't matter. The added amount is 0.01 to 8 parts by mass, preferably 0.1 to 4 parts by mass with respect to 100 parts by mass of the toner.

  Next, a procedure for manufacturing toner will be described.

<Toner production method>
The toner used in the present invention is obtained by melt-kneading a binder resin, a colorant, wax, and an arbitrary material, cooling and pulverizing, and performing spheroidizing treatment and classification treatment of the pulverized product as necessary, It is particularly preferable to produce this by mixing the fluidizing agent as necessary.

  First, in the raw material mixing step, as a toner internal additive, at least a resin and a colorant are weighed and mixed in a predetermined amount and mixed. Examples of the mixing apparatus include a double-con mixer, a V-type mixer, a drum-type mixer, a super mixer, a Henschel mixer, and a Nauter mixer.

  Further, the toner raw materials blended and mixed as described above are melt-kneaded to melt the resins and disperse the colorant and the like therein. In the melt-kneading step, for example, a batch kneader such as a pressure kneader or a Banbury mixer, or a continuous kneader can be used. In recent years, single-screw or twin-screw extruders have become mainstream due to the advantage of being capable of continuous production. For example, the KTK type twin screw extruder manufactured by Kobe Steel, the TEM type twin screw extruder manufactured by Toshiba Machine Co., Ltd., the twin screw extruder manufactured by Kay C.K. The Furthermore, the colored resin composition obtained by melt-kneading the toner raw material is rolled by a two-roll roll after melt-kneading, and then cooled through a cooling step of cooling by water cooling or the like.

  The cooled product of the colored resin composition obtained above is then pulverized to a desired particle size in a pulverization step. In the pulverization step, first, coarse pulverization is performed by a crusher, a hammer mill, a feather mill or the like, and further, fine pulverization is performed by a known wind-type pulverizer or mechanical pulverizer. In the pulverization step, the toner is pulverized to a predetermined toner particle size step by step. Further, the obtained finely pulverized product is subjected to surface modification = spheronization treatment in a surface modification step to obtain surface modified particles. After that, if necessary, the surface modified particles are classified into classifiers such as an inertia class elbow jet (manufactured by Nippon Steel & Mining Co., Ltd.), a centrifugal classifier turboplex (manufactured by Hosokawa Micron Co., Ltd.), or a high-voltage winder (new) Classification is performed using a sieving machine such as Tokyo Machine Co., Ltd. to obtain a toner having a weight average particle diameter of 3 to 11 μm.

  The toner coarse powder generated in the classification step is returned to the pulverization step and pulverized. Further, it is preferable in terms of toner productivity that the fine powder generated in the surface modification process is returned to the toner raw material blending process and reused.

  Furthermore, in the method for producing a toner of the present invention, it is preferable that inorganic fine particles for imparting fluidity are externally added to the toner obtained as described above as an external additive. As a method of externally adding an external additive to the toner, a predetermined amount of classified toner and various known external additives are blended, and high-speed agitation is applied to give a shearing force to a powder such as a Henschel mixer, a super mixer, or a Q mixer. It is preferable to stir and mix using a machine as an external additive machine. At this time, since heat is generated inside the external addition machine and agglomerates are easily generated, it is preferable to adjust the temperature by means such as cooling the periphery of the container portion of the external addition machine with water.

  Next, a mechanical pulverizer is preferably used in the toner pulverization step of the present invention.

  FIG. 6 shows an example of a toner particle pulverizer system incorporating the mechanical pulverizer used in the present invention.

  In the mechanical pulverizer 301 shown in FIG. 6, the casing 313, the jacket 316 in the casing 313, through which cooling water can flow, and the rotating body in the casing 313 attached to the central rotating shaft 312 rotate at high speed. A rotor 314 provided with a large number of grooves on the surface, a stator 310 provided with a large number of grooves on the outer surface of the rotor 314 at a constant interval, and a raw material to be treated. A raw material inlet 311 for introduction and a raw material outlet 302 for discharging the processed powder are configured. A space between the rotor 314 and the stator 310 is a grinding zone.

  In the mechanical pulverizer configured as described above, when a predetermined amount of powder raw material is charged into the raw material charging port 311 of the mechanical pulverizer shown in FIG. It is introduced into the processing chamber. The impact generated between the rotor 314 provided with a large number of grooves on the surface rotating at high speed in the pulverization chamber and the stator 310 provided with a large number of grooves on the surface, and the many generated behind this Are pulverized instantaneously by the ultrahigh-speed vortex flow and the high-frequency pressure vibration generated thereby. Thereafter, the material passes through the material discharge port 302 and is discharged. The air carrying the toner particles passes through the pulverization chamber and is discharged out of the apparatus system through the raw material discharge port 302, the pipe 219, the collecting cyclone 229, the bag filter 222, and the suction blower 224. Is done. In the present invention, since the powder raw material is pulverized in this way, it is preferable because a desired pulverization process can be easily performed without increasing the fine powder and coarse powder. These mechanical pulverizers are used in the pulverization step, but may be used in the surface modification step.

  Examples of such a mechanical pulverizer include Kawasaki Heavy Industries Co., Ltd. pulverizer Kryptron, Turbo Industry Co., Ltd. turbo mill, Hosokawa Micron Co., Ltd. Inomizer, Nisshin Engineering Co., Ltd. super rotor, etc. Can do.

  In the present invention, the surface modification apparatus shown in FIG. 7 that can perform classification and surface modification treatment at the same time is preferably used.

  The batch type surface reforming apparatus shown in FIG. 7 includes a cylindrical main body casing 30, a top plate 43 installed on the upper portion of the main body casing so as to be openable and closable; a fine powder discharge section 44 having a fine powder discharge casing and a fine powder discharge pipe; A cooling jacket 31 through which cooling water or antifreeze can be passed; a plurality of square disks 33 on the upper surface, which are attached to the central rotating shaft in the main body casing 30 as surface modification means, in a predetermined direction Dispersion rotor 32, which is a disk-like rotating body that rotates at high speed; liner 34 that is fixedly arranged around dispersion rotor 32 at a constant interval and that has a large number of grooves on the surface facing dispersion rotor 32 A classification rotor 35 for continuously removing fine powder and ultrafine powder having a predetermined particle size or less in the finely pulverized product; cold air inlet 4 for introducing cold air into the main body casing 30; A charging pipe having a raw material charging port 37 and a raw material supplying port 39 formed on the side surface of the main body casing 30 for introducing finely pulverized material (raw material); discharging toner particles after the surface modification treatment to the outside of the main body casing 30; A product discharge pipe having a product discharge port 40 and a product extraction port 42 for opening and closing; an openable and closable raw material installed between the raw material input port 37 and the raw material supply port 39 so that the surface modification time can be freely adjusted A supply valve 38; and a product discharge valve 41 installed between the product discharge port 40 and the product extraction port 42.

  It is preferable for the surface of the liner 34 to have a groove for efficient surface modification of the toner particles. The number of square disks 33 is preferably an even number in consideration of the rotational balance.

  It is preferable that the classification rotor 35 rotates in the same direction as the rotation direction of the dispersion rotor 32 in order to increase the efficiency of classification and the surface modification efficiency of the toner particles.

  The fine powder discharge pipe has a fine powder discharge port 45 for discharging fine powder and ultrafine powder removed by the classification rotor 35 to the outside of the apparatus.

  The surface modifying apparatus has a cylindrical guide ring 36 as a guide means having an axis perpendicular to the top plate 43 in the main body casing 30. The upper end of the guide ring 36 is provided at a predetermined distance from the top plate, and the guide ring is fixed to the main body casing 30 by a support so as to cover at least a part of the classification rotor 36. The lower end of the guide ring 36 is provided at a predetermined distance from the rectangular disk 33 of the dispersion rotor 32.

  In the surface modification apparatus, a space between the classification rotor 35 and the dispersion rotor 32 is guided into a first space 47 outside the guide ring 36 and a second space 48 inside the guide ring 36. Divided by 36. The first space 47 is a space for guiding the finely pulverized product and the surface-modified particles to the classification rotor 35, and the second space guides the finely pulverized product and the surface-modified particles to the dispersion rotor. It is a space for. A gap between the plurality of rectangular disks 33 installed on the dispersion rotor 32 and the liner 34 is a surface modification zone 49, and the classification rotor 35 and a peripheral portion of the classification rotor 35 are classification zones 50. .

  The finely pulverized product introduced into the raw material hopper 380 is supplied into the apparatus from the raw material supply port 39 through the raw material supply port 38 through the raw material supply port 37 via the fixed amount feeder 315. In the surface reforming apparatus, the cold air generated by the cold air generating means 319 is supplied into the main body casing from the cold air inlet 46, and further, the cold water from the cold water generating means 320 is supplied to the cold water jacket 31 to Adjust the temperature to a predetermined temperature. The supplied finely pulverized product swirls in the first space 47 outside the cylindrical guide ring 36 by the swirl flow formed by the suction air volume by the blower 364, the rotation of the dispersion rotor 32 and the rotation of the classification rotor 35. However, the classification process is performed by reaching the classification zone 50 in the vicinity of the classification rotor 35. The direction of the swirl flow formed in the main body casing 30 is the same as the rotation direction of the dispersion rotor 32 and the classification rotor 35.

  Fine powder and super fine powder to be removed by the classifying rotor 35 are sucked from the slit of the classifying rotor 35 by the suction force of the blower 364 and passed through the fine powder discharge port 45 and the cyclone inlet 359 of the fine powder discharge pipe to the cyclone 369 and the bug 362. It is collected. The finely pulverized product from which fine powder and ultrafine powder have been removed reaches the surface modification zone 49 in the vicinity of the dispersion rotor 32 via the second space 48, and the square disk 33 (hammer) provided in the dispersion rotor 32 and the main body. The surface modification treatment of the particles is performed by the liner 34 provided in the casing 30. The particles subjected to the surface modification reach the classification rotor 35 again while turning along the guide ring 36, and fine particles and ultrafine particles are removed from the surface-modified particles by the classification rotor 35 classification. . After performing the treatment for a predetermined time, the discharge valve 41 is opened, and the surface-modified toner particles from which fine powder having a predetermined particle diameter or less and ultrafine powder are removed are taken out from the surface reforming apparatus.

  The toner particles adjusted to a predetermined weight average diameter, adjusted to a predetermined particle size distribution, and further surface-modified to a predetermined circularity are transferred to the external additive adding step by the toner particle transport means 321. .

  The surface reforming apparatus used in the present invention includes a dispersion rotor 32, a finely pulverized product (raw material) input unit 39, a classification rotor 35, and a fine powder discharge unit from the lower side in the vertical direction. Therefore, normally, the drive portion (motor or the like) of the classification rotor 35 is provided further above the classification rotor 35, and the drive portion of the dispersion rotor 32 is provided further below the dispersion rotor 32. The surface reforming apparatus used in the present invention is a finely pulverized product (raw material) classified into a classification rotor, such as a TSP classifier (manufactured by Hosokawa Micron Corporation) having only a classification rotor 35 described in JP-A-2001-259451. It is difficult to supply from the vertically upward direction of 35.

  In the present invention, it is preferable that the tip peripheral speed of the classification rotor 35 having the largest diameter is 30 to 120 m / sec. The tip circumferential speed of the classification rotor is more preferably 50 to 115 m / sec, and further preferably 70 to 110 m / sec. If it is slower than 30 m / sec, the classification yield tends to decrease, and the amount of ultrafine powder tends to increase in the toner particles. If it is faster than 120 m / sec, the problem of increased vibration of the device is likely to occur.

  Furthermore, it is preferable that the tip peripheral speed of the portion with the largest diameter of the dispersion rotor 32 is 20 to 150 m / sec. The tip peripheral speed of the dispersion rotor 32 is more preferably 40 to 140 m / sec, and further preferably 50 to 130 m / sec. When it is slower than 20 m / sec, it is difficult to obtain surface-modified particles having sufficient circularity, which is not preferable. When the speed is higher than 150 m / sec, particles are likely to be fixed inside the apparatus due to the temperature rise inside the apparatus, and the classification yield of the toner particles is likely to be lowered. By setting the tip peripheral speeds of the classification rotor 35 and the dispersion rotor 32 in the above range, the classification yield of the toner particles can be improved and the surface modification of the particles can be performed efficiently.

  The surface modification step described above is preferably used because the UV transmittance of the toner used in the image forming method of the present invention with respect to the 45% MeOH aqueous solution can be adjusted in the range of 10 to 80%.

  Next, the image forming method of the present invention will be described in detail.

<Image forming method>
An example of an image forming apparatus using the image forming method of the present invention is shown in FIG. In FIG. 1, an electrophotographic photosensitive member 1 which is an electrostatic latent image carrier rotates in the direction of an arrow in the figure. The photosensitive member 1 is charged by a charging device 2 as a charging unit, and a laser beam L is projected onto the charged surface of the photosensitive member 1 by an exposure device 3 as an electrostatic latent image forming unit to form an electrostatic latent image. . Thereafter, the electrostatic latent image is visualized as a toner image by the developing device 4 as the developing means, and is transferred to the transfer material P by the transfer device 5 as the transfer means. The transfer material P is the fixing device as the fixing means. 6 is heated and fixed and output as an image. In this transfer means, untransferred toner remaining on the surface of the photosensitive member without being transferred is collected by a cleaning device 7 which is a cleaning means as shown in FIG. 2, or by a smoothing means as shown in FIG. An auxiliary brush charging device 8 applies an electrostatic polarity to the transfer residual toner while applying a bias, and is supplied to the developing device again through the charging device and the electrostatic latent image forming device, or collected by the developing device. May be.

  Here, each step of the image forming method that can be used in the present invention will be described in more detail.

<Charging process>
The charging step is not particularly limited as long as it is a means for charging the surface of the photoconductor to charge the electrophotographic photoconductor. As the charging means, a device for charging the electrophotographic photosensitive member without contact with the electrophotographic photosensitive member, such as a corona charging means, or an electrophotographic photosensitive member by contacting a conductive roller or blade with the electrophotographic photosensitive member. Devices that charge the body can be used.

<Electrostatic latent image forming process>
In the electrostatic latent image forming step, a known exposure apparatus can be used as the exposure means. For example, a semiconductor laser or a light emitting diode is used as the light source, and a scanning optical system unit including a polygon mirror, a lens, and a mirror can be used.

  The area where the electrostatic latent image can be formed includes an area in the main scanning direction and an area in the sub scanning direction. The region in the main scanning direction on the photoconductor is a region from a laser beam irradiation start position to a laser beam irradiation end position in a direction parallel to the rotation axis of the photoconductor. Further, the sub-scanning direction area on the photosensitive member surface is an area from the irradiation position of the first main scanning line to the irradiation position of the last main scanning line in one page of image data.

  The electrostatic latent image forming process will be specifically described. First, a rotating polygon mirror is irradiated with a laser beam from a semiconductor laser as a light source. Then, the laser beam periodically deflected and reflected is focused by the scanning lens, and the photosensitive member rotating in the sub-scanning direction is repeatedly scanned in the main scanning direction orthogonal to the sub-scanning direction. Then, the electrostatic latent image is exposed.

  In the printing mode (also referred to as borderless copying) corresponding to the entire border provided in the image forming apparatus using the image forming method of the present invention, this electrostatic latent image formable area is different.

  That is, the marginless copy has a larger area in the main scanning direction and / or sub-scanning direction of the electrostatic latent image formable area than the margined copy. This is because when marginless copying is performed, there is no margin larger than the size of the recording material in order to correct and erase the margin caused by a small size error between the image size of the image data and the actual size of the recording material. This is because it needs to be reflected in the copy magnification.

  When borderless copy is selected, the exposure apparatus sets the image resolution by setting the main scanning pixel clock and polygon mirror rotation period. The main scanning pixel clock is set by a write clock generation circuit. The polygon mirror rotation period is set by a rotation motor control circuit of the polygon mirror. In addition, the exposure apparatus performs main scanning magnification adjustment and sub-scanning magnification adjustment in the bordered printing mode by finely adjusting the settings of the main scanning pixel clock and the polygon rotation period. Based on this, the main scanning magnification adjustment and the sub scanning magnification adjustment for the borderless image in the borderless copy are performed.

  As described above, the electrostatic latent image formed on the photoreceptor in the electrostatic latent image process is visualized as a toner image by the developer in the development process.

<Development process>
The development process is mainly divided into a one-component contact development method that does not require a carrier and a two-component development method that includes a toner and a carrier, and any of them can be used. In the present invention, a two-component development method will be described as an example from the viewpoint of high image quality, which is a need for borderless copying.

  As a two-component development method, a magnetic brush of a two-component developer having a nonmagnetic toner and a magnetic carrier is formed on a developer carrier (development sleeve) containing a magnet, and the magnetic brush is formed with a developer layer thickness. After coating with a regulating member to a predetermined layer thickness, the magnetic brush is transported to a developing area facing the photoreceptor, and the magnetic brush is applied while applying a predetermined developing bias between the photoreceptor and the developing sleeve in the developing area. Is a method in which the electrostatic latent image is visualized as a toner image by bringing the toner close to or in contact with the surface of the photoreceptor.

  Examples of the magnetic carrier that can be used in such a two-component developer include an iron powder carrier, a ferrite carrier, and a magnetic fine particle dispersed resin carrier in which magnetic fine particles are dispersed in a binder resin. In the iron powder carrier, since the specific resistance of the carrier itself is low, the charge of the electrostatic latent image leaks through the carrier, and the electrostatic latent image may be disturbed, thereby causing an image defect. Also, in the ferrite carrier, although the specific resistance of the carrier itself is relatively high, the magnetic brush tends to be stiff due to the large saturation magnetization, and the magnetic brush has uneven spots on the toner image. There is. Therefore, a magnetic fine particle dispersed resin carrier in which magnetic fine particles are dispersed in a binder resin is preferably used. The magnetic fine particle-dispersed resin carrier has a relatively higher specific resistance than a ferrite carrier, a small saturation magnetization, and a small true specific gravity. Therefore, it is possible to prevent charge leakage of an electrostatic latent image. Furthermore, since the magnetic brush does not become rigid, it is preferable in that a good toner image can be formed without image defects and unevenness in the stitches.

  Further, a resin coating layer may be provided on the surface of the magnetic fine particle dispersed resin carrier. As a material constituting the resin coating layer, at least a binder resin may be used, but conductive fine particles as a resistance adjusting agent, fine particles for forming irregularities, and charge control having a charge imparting property to toner. You may contain additives, such as material. Furthermore, in order to improve the adhesiveness between the carrier surface and the resin coating layer, it may be treated with a coupling agent or the like.

<Transfer process>
The transfer process is a method of transferring the toner image on the surface of the photoconductor to the transfer material without contact with the photoconductor, such as a corona transfer means, or contacting the photoconductor with a transfer member such as a roller or an endless belt. There are methods for transferring a toner image on the body surface onto a transfer material, and any of them can be used.

<Cleaning process>
In addition, as shown in FIG. 2, the image forming method of the present invention may further include a cleaning step 7 for cleaning the transfer residual toner on the photosensitive member after the transfer and before the charging step. In the cleaning process 7, there are known methods such as blade cleaning, fur brush cleaning, roller cleaning, etc., but any of them can be used.

<Leveling process>
Further, in the image forming method of the present invention, as shown in FIG. 3, the transfer residual toner on the photosensitive member is leveled after the transfer and before the charging step, thereby improving the recovery rate of the transfer residual toner at the time of development. Therefore, for the purpose of making the charging polarity of the transfer residual toner uniform, a leveling step 8 having a bias applying means may be further included.

  In the leveling step 8, when the toner is negatively charged, it is preferable to apply a bias for negatively charging the transfer residual toner to reduce adhesion of the transfer residual toner to the charging member in the charging step. This improves the recovery rate of the transfer residual toner during development. Further, as the leveling member, a brush-like member is preferably used. Furthermore, it is preferable to provide a plurality of such leveling members because the transfer residual toner adheres to the charging member and the recovery rate of the transfer residual toner during development increases.

<Fixing process>
For the fixing process, a conventional roll nip type fixing device 6 composed of a pair of rollers as shown in FIG. 1 and a belt nip method corresponding to higher speed and energy saving of the recent image forming apparatus shown in FIG. 4 are used. Any fixing device such as the fixing device 9 may be used. In the present invention, a belt nip method will be described as an example from the viewpoint of speeding up and energy saving of an image forming apparatus and diversification of recording materials.

  In the belt nip method, since at least one member forming the nip is an endless belt, a wide nip (wide nip) can be easily formed, so the heating time of the recording material can be increased, and high-speed fixing is performed. It can be said that it is advantageous. On the other hand, the roll nip method is disadvantageous from the viewpoint of energy saving because the elastic layer needs to be thick in order to form a wide nip so that the heat capacity becomes large. Therefore, a belt nip method that can easily form a wide nip without increasing the thickness of the elastic layer is preferably used in the present invention as a fixing method that has a small heat capacity and can achieve both high speed and energy saving.

  On the other hand, in the belt nip method described above, the applied pressure in the nip is smaller than that in the roll nip method. If the applied pressure is increased in the belt nip method, the belt slips against the rotating body that drives the belt, or the belt moves to the left and right of the roller that stretches the belt. There must be. As described above, the “pressure” in the belt nip method is lighter than that in the roller nip method.

  However, in the image forming method of the present invention, when forming an image corresponding to the entire borderless area, the smaller the pulling force of the recording material into the fixing nip portion, the more the fixing of the toner image at the leading end of the recording material is disturbed or the toner scatters. It is possible to further suppress the scattering phenomenon, further suppress the contamination of the fixing member, and further, when the recording material has a different thickness, the pressure applied at the fixing nip portion is particularly effective from the viewpoint of preventing paper wrinkles and toner image disturbance on thin paper. However, since the light pressure fixing method is preferably used, it can be said that the belt nip method as described above is suitable.

  The fixing pressure in the fixing step of the image forming method of the present invention is preferably 0.03 to 0.30 MPa. By setting the fixing pressure, that is, the pressure applied to the toner image at the fixing nip portion to 0.03 to 0.30 MPa, the force for drawing the recording material into the fixing nip portion can be reduced. Fixation scattering phenomenon such as toner image disturbance and toner scattering on the recording material can be further suppressed, and contamination of the fixing member can be further suppressed. When the fixing pressure exceeds 0.30 MPa, the force for drawing the recording material into the fixing nip portion increases, and the fixing scattering phenomenon such as toner image disturbance or toner scattering on the recording material tends to be deteriorated. . If the fixing pressure is less than 0.03 MPa, the pressure applied to the toner image is too small, and heat may not be transmitted to the toner image, and toner that cannot be melted may contaminate the fixing member.

<Full-color image forming apparatus>
An example of a full color image forming apparatus using the image forming method of the present invention is shown in FIG. The arrows indicating the arrangement and rotation direction of PK, PY, PC, and PM in the drawing are not limited to these. In FIG. 5, the electrophotographic photoreceptors 1K, 1Y, 1C1M, which are electrostatic latent image carriers, rotate in the direction of the arrow in the figure. Each photoconductor is charged by charging devices 2K, 2Y, 2C, and 2M that are charging means, and laser light is applied to the charged surface of each photoconductor by exposure devices 3K, 3Y, 3C, and 3M that are electrostatic latent image forming means. L is projected to form an electrostatic latent image. Thereafter, the electrostatic latent images are visualized as toner images by developing devices 10K, 10Y, 10C, and 10M that are developing means, and transferred to the transfer material P by transfer devices 19K, 19Y, 19C, and 19M that are transfer means. The transfer material P is heated and fixed by the fixing device 12 as a fixing unit and is output as an image. Here, 17K, 17Y, 17C, and 17M are developer carriers, 13 is a transfer belt, and 14 and 15 are drive members for the transfer belt.

  Below, the measuring method concerning this invention is described in detail.

<Measurement of storage elastic modulus G ′ (140 ° C.) of toner>
G ′ (140 ° C.) in the present invention is determined by the following method.

ARES (Rheometric Scientific F.E. Co., Ltd.) was used as a measuring device. Under the following conditions, the storage elastic modulus G ′ in the temperature range of 60 to 200 ° C. was measured.
Measurement jig: A circular parallel plate having a diameter of 8 mm is used. A shallow cup corresponding to a circular parallel plate is used on the actuator side. The gap between the bottom of the shallow cup and the circular plate is about 2 mm.
・ Measurement sample: Toner is used after being pressure-molded into a disk-shaped sample with a diameter of about 8 mm and a height of about 2 mm.
Measurement frequency: 6.28 radians / second Measurement strain setting: The initial value is set to 0.1%, and then the measurement is performed in the automatic measurement mode.
-Sample extension correction: Adjust in automatic measurement mode.
Measurement temperature: The temperature is raised from 60 to 200 ° C. at a rate of 2 ° C. per minute.

  The storage elastic modulus G ′ at 140 ° C. when the storage elastic modulus G ′ was measured in the temperature range of 60 to 200 ° C. by the above method was defined as G ′ (140 ° C.).

<Measurement of wettability of toner with 45% methanol aqueous solution>
The UV transmittance (wettability) in a 45 volume% methanol aqueous solution of the toner is measured as follows. First, an aqueous solution having a volume mixing ratio of methanol: water of 45:55 is prepared. 10 ml of this aqueous solution is placed in a 30 ml sample bottle (Nippon Denka Glass: SV-30), and 20 mg of toner is impregnated on the liquid surface to cover the bottle. Thereafter, the mixture is shaken for 10 seconds at 2.5 S ⁻¹ with a Yayoi type shaker (model: YS-LD). At this time, the angle of shaking is such that the shaking column moves 15 degrees forward and 20 degrees backward, assuming that the vertical (vertical) of the shaker is 0 degree. The sample bottle is fixed to a fixing holder (with the sample bottle lid fixed on the extension at the center of the column) attached to the tip of the column. After removing the sample bottle, the dispersion after 30 seconds is used as a dispersion for measurement.

The dispersion is put into a 1 cm square quartz cell, and the transmittance (%) at a wavelength of 600 nm of the dispersion after 10 minutes is measured using a spectrophotometer MPS2000 (manufactured by Shimadzu Corporation).
Transmittance (%) = I / I ₀ × 100 (I: incident light beam, I ₀ : transmitted light beam)

<Measurement of average circularity of toner>
The average circularity of the toner is measured using a flow type particle image measuring device “FPIA-2100 type” (manufactured by Sysmex Corporation), and is calculated using the following equation.

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

  In the present invention, the circularity is an index indicating the degree of unevenness of the toner particles, and is 1.000 when the toner particles are completely spherical. The more complicated the surface shape, the smaller the circularity.

  The average circularity C, which means the average value of the circularity frequency distribution, is calculated from the following equation, where ci is the circularity (center value) at the dividing point i of the particle size distribution and m is the number of measured particles.

  In addition, “FPIA-2100”, which is a measuring apparatus used in the present invention, calculates the circularity of each particle, and then calculates the average circularity. 1.0 is divided into classes equally divided every 0.01, and the average circularity is calculated using the center value of the division points and the number of measured particles.

  As a specific measuring method, 10 ml of ion-exchanged water from which impure solids have been removed in advance is prepared in a container, and a surfactant, preferably an alkylbenzene sulfonate, is added as a dispersant therein, followed by further measurement. Add 0.02 g of sample and disperse uniformly. As a means for dispersion, an ultrasonic disperser “Tetora 150 type” (manufactured by Nikka Ki Bios Co., Ltd.) is used, and dispersion treatment is performed for 2 minutes to obtain a dispersion for measurement. In that case, it cools suitably so that the temperature of this dispersion may not be 40 degreeC or more. In order to suppress variation in circularity, the installation environment of the apparatus is controlled at 23 ° C. ± 0.5 ° C. so that the temperature inside the flow type particle image analyzer FPIA-2100 is 26 to 27 ° C. Preferably, autofocus is performed using 2 μm latex particles every 2 hours.

  To measure the circularity of the toner particles, the flow type particle image measuring device is used, and the concentration of the dispersion is readjusted so that the toner particle concentration at the time of measurement is 3000 to 10,000 particles / μl. Measure more than one. After the measurement, using this data, data having an equivalent circle diameter of less than 2 μm is cut to determine the average circularity of the toner particles.

  Furthermore, “FPIA-2100”, which is a measuring apparatus used in the present invention, has a thinner sheath flow (7 μm) than “FPIA-1000” that has been used to calculate the shape of the toner. (To 4 μm) and the processing particle image magnification, and the processing resolution of the captured image is improved (256 × 256 → 512 × 512), so that the accuracy of toner shape measurement is improved, thereby making sure the fine particles are more reliable. A device that has achieved supplementation. Therefore, when it is necessary to measure the shape more accurately as in the present invention, the FPIA 2100 that can obtain information on the shape more accurately is more useful.

<Toner compression degree C measurement>
First, a loose apparent density A (g / cm ³ ) was measured using a powder tester PT-R (manufactured by Hosokawa Micron Corporation). The measurement environment was 23 ° C. and 50% RH. In the measurement, the developer was collected in a metal cup having a volume of 100 ml using a sieve having an opening of 75 μm and vibrating with an amplitude of 1 mm, and was scraped to just 100 ml. The loose apparent density A (g / cm ³ ) was calculated from the developer mass collected in the metal cup.

Next, the apparent apparent density P (g / cm ³ ) was measured. Using a sieve with a mesh opening of 75 μm, the developer is replenished so that it overflows from the metallic cup while vibrating with an amplitude of 1 mm, and the metallic cup is tapped up and down 180 times with an amplitude of 18 mm. The solid apparent density P (g / cm ³ ) was calculated from the developer weight after tapping.

And the compression degree C was calculated | required by following formula (1).
Compression degree C (%) = 100 × (PA) / P (1)

<Molecular weight distribution of binder resin and toner by GPC measurement>
The molecular weight of the chromatogram by gel permeation chromatography (GPC) is measured under the following conditions. For the measurement, HLC-8120GPC (manufactured by Tosoh Corporation) was used.

The column was stabilized in a heat chamber at 40 ° C., and tetrahydrofuran (THF) as a solvent was passed through the column at this temperature at a flow rate of 1 ml / min, and the sample concentration was adjusted to 0.05 to 0.6% by mass. About 50 to 200 μl of THF sample solution is injected and measured. In measuring the molecular weight of a sample, the molecular weight distribution of the sample is calculated from the relationship between the logarithmic value of a calibration curve prepared from several types of monodisperse polystyrene standard samples and the number of counts (retention time). Examples of standard polystyrene samples for preparing a calibration curve include those manufactured by Tosoh Corporation or Pressure Chemical Co. The molecular weights manufactured are 6 × 10 ² , 2.1 × 10 ³ , 4 × 10 ³ , 1.75 × 10 ⁴ , 5.1 × 10 ⁴ , 1.1 × 10 ⁵ , 3.9 × 10 ⁵ , 8 ^{.6 × 10 5, 2 × 10} 6, used as a 4.48 × 10 ^6, it is appropriate to use at least about 10 standard polystyrene samples. An RI (refractive index) detector is used as the detector.

As a column, in order to accurately measure a molecular weight region of 10 ^{3 to} 2 × 10 ⁶ , it is preferable to combine a plurality of commercially available polystyrene gel columns. For example, shodex GPC KF-801, 802, 803 manufactured by Showa Denko KK , 804, 805, 806, and 807, and combinations of μ-styragel 500, 10 ³ , 10 ⁴ , and 10 ⁵ manufactured by Waters.

<Measurement of softening point of binder resin and toner by flow tester>
Based on JIS K 7210, measurement is performed with an elevated flow tester. A specific measurement method is shown below. While a 1 cm3 sample was heated at a heating rate of 6 ° C / min using a Koka flow tester (manufactured by Shimadzu Corporation), a load of 1960 N / m2 (20 kg / cm2) was applied by a plunger, and the diameter was 1 mm and the length A nozzle of 1 mm is pushed out, thereby drawing a plunger descending amount (flow value) -temperature curve, where the height of the S-shaped curve is h, the temperature corresponding to h / 2 (half of the resin is The temperature that flows out) is defined as the softening point Tm (° C.) of the resin.

<Measurement of maximum endothermic peak in wax DSC>
The maximum endothermic peak of the toner and the wax can be measured according to ASTM D3418-82 using a differential thermal analyzer (DSC measuring device) and DSC2920 (TA Instruments Japan).

Temperature curve: Temperature increase I (20 ° C. to 200 ° C., temperature increase rate 10 ° C./min)
Temperature drop I (200 ° C to 20 ° C, temperature drop rate 10 ° C / min)
Temperature increase II (20 ° C to 200 ° C, temperature increase rate 10 ° C / min)
As a measuring method, 5 to 20 mg, preferably 10 mg of a measurement sample is accurately weighed. This is put into an aluminum pan, and an empty aluminum pan is used as a reference, and measurement is performed at a temperature rise rate of 10 ° C./min and normal temperature and humidity in a measurement temperature range of 30 to 200 ° C. The maximum endothermic peak of the toner is determined in the process of temperature increase II, the one having the highest height from the baseline in the region above the endothermic peak of the resin Tg, or the endothermic peak of the resin Tg overlaps with another endothermic peak. If this is difficult, the maximum endothermic peak of the toner of the present invention is defined as the highest peak from the maximum peak of the overlapping peaks.

<Measurement of toner particle size distribution>
As a measuring device, Coulter Counter TA-II or Coulter Multisizer II (manufactured by Coulter Inc.) is used. As the electrolytic solution, an about 1% NaCl aqueous solution is used. As the electrolytic solution, an electrolytic solution prepared using primary sodium chloride or, for example, ISOTON (registered trademark) -II (manufactured by Coulter Scientific Japan) can be used.

  As a measurement method, 0.1 to 5 ml of a surfactant (preferably alkylbenzenesulfone hydrochloride) is added as a dispersant to 100 to 150 ml of the electrolytic aqueous solution, and 2 to 20 mg of a measurement sample is further added. The electrolytic solution in which the sample is suspended is dispersed for about 1 to 3 minutes with an ultrasonic disperser, and the volume and number of the sample are measured for each channel by the measuring device using a 100 μm aperture as the aperture. The volume distribution and the number distribution are calculated. From these obtained distributions, the weight average particle diameter (D4) of the sample is determined. As channels, 2.00 to 2.52 μm; 2.52 to 3.17 μm; 3.17 to 4.00 μm; 4.00 to 5.04 μm; 5.04 to 6.35 μm; 6.35 to 8. 00 μm; 8.00 to 10.08 μm; 10.08 to 12.70 μm; 12.70 to 16.00 μm; 16.00 to 20.20 μm; 20.20 to 25.40 μm; 25.40 to 32.00 μm; 13 channels of 32-40.30 μm are used.

  Hereinafter, the present invention will be described in more detail with reference to specific production examples and examples, but the present invention is not limited thereto.

<Production Example 1 of Toner Resin>
30 parts by mass of polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane, 10 parts by mass of polyoxyethylene (2.2) -2,2-bis (4-hydroxyphenyl) propane, Put 20 parts by mass of terephthalic acid, 3 parts by mass of trimellitic anhydride, 27 parts by mass of fumaric acid and dibutyltin oxide into a 4 liter glass four-necked flask, and add four thermometers, stirring rods, condensers and nitrogen inlet tubes. The flask was attached to a neck flask, and this four-neck flask was placed in a mantle heater. Under a nitrogen atmosphere, the reaction time was changed at 210 ° C. to obtain polyester resins (B-1) to (B-3) and (b-1) to (b-2). Table 1 shows the physical properties of the obtained polyester resin.

<Toner resin production example 2>
As a vinyl copolymer material, 10 parts by mass of styrene, 5 parts by mass of 2-ethylhexyl acrylate, 2 parts by mass of fumaric acid, and 5 parts by mass of a dimer of α-methylstyrene were placed in a dropping funnel. . In addition, 25 parts by mass of polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane, 15 parts by mass of polyoxyethylene (2.2) -2,2-bis (4-hydroxyphenyl) propane Part, 9 parts by mass of terephthalic acid, 5 parts by mass of trimellitic anhydride, 24 parts by mass of fumaric acid and dibutyltin oxide are placed in a 4-liter four-necked flask made of glass, and a thermometer, a stir bar, a condenser and a nitrogen inlet tube are placed. The flask was attached to a four-necked flask, and this four-necked flask was placed in a mantle heater. Next, after the inside of the four-necked flask was replaced with nitrogen gas, the temperature was gradually raised while stirring, and while stirring at a temperature of 130 ° C., the monomer of the vinyl copolymer and the cross-linking from the previous dropping funnel The agent and the polymerization initiator were added dropwise over about 4 hours. Subsequently, the temperature was raised to 200 ° C., and the reaction time was changed to obtain hybrid resins (B-4) to (B-6) and (b-3) to (b-4).

  Table 1 shows the physical properties of the obtained hybrid resin.

<Production Example 3 of Toner Resin>
A styrene-acrylic resin was prepared using the following raw materials.

Styrene 83.0 parts by mass n-butyl acrylate 17.0 parts by mass Di-tert-butyl peroxide 1.0 part by mass The above raw materials were dropped into 200 parts by mass of heated xylene over 4 hours. Further, the polymerization reaction was completed under reflux of xylene, and the solvent was distilled off while raising the temperature to 200 ° C. under reduced pressure. Here, the reaction time is changed to styrene-acrylic resins (B-7) to (B-8) and (b-5) to (b-6).

<Toner Production Example 1>
Toner (A-1) was produced using the following materials and production method.

100 mass parts of said polyester resin (B-1) C.I. I. Pigment Blue 15: 3 5 parts by mass paraffin wax (W-1: maximum endothermic peak 73 ° C.) 7 parts by mass After the above materials were mixed with a Henschel mixer (FM-75 type, manufactured by Mitsui Miike Chemical Co., Ltd.), The mixture was melt kneaded with a twin screw extruder set at a temperature of 140 ° C. The obtained kneaded product was cooled and coarsely pulverized to 1 mm or less with a hammer mill to obtain a coarsely pulverized toner. The resulting coarsely pulverized toner was finely pulverized using a mechanical pulverizer as shown in FIG. As pulverization conditions, pulverization processing (processing α) was performed with the rotational speed of the rotor being 100 s ⁻¹ .

Next, the obtained finely pulverized product was removed by using a surface modification treatment apparatus as shown in FIG. 7 while removing fine particles at a classification rotor rotational speed of 120 s ⁻¹ , while dispersing rotor rotational speed of 100 s ⁻¹ (rotational peripheral speed). Was subjected to surface treatment at 130 m / sec) for 60 seconds to obtain a toner classified product.

Then, to 100 parts by mass of the obtained toner classified product, 1.0% by mass of anatase-type titanium oxide (T-1) and 1.0% by mass of hydrophobic silica (S-1) having a BET specific surface area of 130 m ² / g. Was added and mixed with a Henschel mixer (FM-75 type, manufactured by Mitsui Miike Chemical Co., Ltd.) at a rotation speed of 30 s ⁻¹ for 10 minutes to obtain a toner (A-1). The obtained toner (A-1) has a weight average particle diameter (D4) of 5.9 μm, a storage elastic modulus G ′ of 7.6 × 10 ³ dN / m ² , and is stirred and mixed in a 45% methanol solution. The UV transmittance of the toner was 51%, the average circularity was 0.930, and the toner compression degree C was 49%.

<Toner Production Example 2>
Toner (A-2) was obtained in the same manner as in Toner Production Example 1, except that polyester resin (B-2) was used instead of polyester resin (B-1) in Toner Production Example 1. Table 1 shows the physical properties of the obtained toner.

<Toner Production Example 3>
In Toner Production Example 1, polyester resin (B-3) instead of polyester resin (B-1), paraffin wax (W-2: maximum endothermic peak 68 ° C.) instead of paraffin wax (W-1), hydrophobicity Toner (A-3) was obtained in the same manner as in Toner Production Example 1 except that oil-treated hydrophobic silica (S-2) was used instead of silica (S-1). Table 1 shows the physical properties of the obtained toner.

<Toner Production Example 4>
In Toner Production Example 1, as in Toner Production Example 1, except that 50 parts by mass of polyester resin (B-2) and 50 parts by mass of polyester resin (B-3) were used instead of polyester resin (B-1). Thus, toner (A-4) was obtained. Table 1 shows the physical properties of the obtained toner.

<Toner Production Example 5>
In Toner Production Example 1, hybrid resin (B-4) instead of polyester resin (B-1), paraffin wax (W-3: maximum endothermic peak 78 ° C.) instead of paraffin wax (W-1), titanium oxide Toner (A-5) was obtained in the same manner as in Toner Production Example 1 except that rutile type titanium oxide (T-2) was used instead of (T-1). Table 1 shows the physical properties of the obtained toner.

<Toner Production Example 6>
Toner (A-6) was obtained in the same manner as in Toner Production Example 1, except that hybrid resin (B-5) was used instead of polyester resin (B-1) in Toner Production Example 1. Table 1 shows the physical properties of the obtained toner.

<Toner Production Example 7>
In Toner Production Example 1, the same conditions as in Toner Production Example 1 were used except that the surface modification treatment conditions were changed and hydrophobic silica (S-2) was used instead of hydrophobic silica (S-1). A-7) was obtained. Table 1 shows the physical properties of the obtained toner.

<Toner Production Example 8>
In Toner Production Example 1, the same conditions as in Toner Production Example 1 were used except that the surface modification treatment conditions were changed and titanium oxide (T-2) was used instead of titanium oxide (T-1). 8) was obtained. Table 1 shows the physical properties of the obtained toner.

<Toner Production Example 9>
In Toner Production Example 1, hybrid resin (B-6) instead of polyester resin (B-1), paraffin wax (W-2) instead of paraffin wax (W-1), and hydrophobic silica (S-1) A toner (A-9) was obtained in the same manner as in Toner Production Example 1 except that hydrophobic silica (S-2) was used in place of. Table 1 shows the physical properties of the obtained toner.

<Toner Production Example 10>
In Toner Production Example 1, similar to Toner Production Example 1 except that 30 parts by mass of hybrid resin (B-4) and 70 parts by mass of hybrid resin (B-6) were used instead of polyester resin (B-1). Thus, toner (A-10) was obtained. Table 1 shows the physical properties of the obtained toner.

<Toner Production Example 11>
In Toner Production Example 1, styrene acrylic resin (B-7) instead of polyester resin (B-1), ester wax (W-4: maximum endothermic peak 79 ° C.) instead of paraffin wax (W-1), hydrophobic Toner (A-11) was obtained in the same manner as in Toner Production Example 1 except that hydrophobic silica (S-2) was used in place of crystalline silica (S-1). Table 1 shows the physical properties of the obtained toner.

<Toner Production Example 12>
In Toner Production Example 1, styrene acrylic resin (B-8) instead of polyester resin (B-1), ester wax (W-5: maximum endothermic peak 72 ° C.) instead of paraffin wax (W-1), hydrophobic Toner (A-12) was obtained in the same manner as in Toner Production Example 1 except that hydrophobic silica (S-2) was used in place of the functional silica (S-1). Table 1 shows the physical properties of the obtained toner.

<Toner Production Example 13>
In Toner Production Example 1 except that 70 parts by mass of polyester resin (B-2) and 30 parts by mass of styrene acrylic resin (B-8) were used instead of polyester resin (B-1). Similarly, a toner (A-13) was obtained. Table 1 shows the physical properties of the obtained toner.

<Toner Production Example 14>
In Toner Production Example 1, C.I. I. Pigment Blue 15: 3 instead of C.I. I. Toner (A-14) was obtained in the same manner as in Toner Production Example 1 except that 7.5 parts by mass of CI Pigment Red 57: 1 was used. Table 1 shows the physical properties of the obtained toner.

<Toner Production Example 15>
In Toner Production Example 1, C.I. I. Pigment Blue 15: 3 instead of C.I. I. A toner (A-15) was obtained in the same manner as in Toner Production Example 1 except that 9.0 parts by mass of Pigment Yellow 74 was used. Table 1 shows the physical properties of the obtained toner.

<Toner Production Example 16>
In Toner Production Example 1, C.I. I. Toner (A-16) was obtained in the same manner as in Toner Production Example 1 except that 5.5 parts by mass of carbon black was used instead of CI Pigment Blue 15: 3. Table 1 shows the physical properties of the obtained toner.

<Toner Production Example 17>
Toner (a-1) was obtained in the same manner as in Toner Production Example 1, except that polyester resin (b-1) was used instead of polyester resin (B-1) in Toner Production Example 1. Table 1 shows the physical properties of the obtained toner.

<Toner Production Example 18>
In Toner Production Example 1, polyester resin (b-2) instead of polyester resin (B-1), paraffin wax (W-2) instead of paraffin wax (W-1), hydrophobic silica (S-1) A toner (a-2) was obtained in the same manner as in Toner Production Example 1 except that hydrophobic silica (S-2) was used instead of. Table 1 shows the physical properties of the obtained toner.

<Toner Production Example 19>
In Toner Production Example 1, hybrid resin (b-3) instead of polyester resin (B-1), paraffin wax (W-3) instead of paraffin wax (W-1), and titanium oxide (T-1) A toner (a-3) was obtained in the same manner as in Toner Production Example 1 except that titanium oxide (T-2) was used instead. Table 1 shows the physical properties of the obtained toner.

<Toner Production Example 20>
Toner Production Example 1 except that the hybrid resin (b-4) was used instead of the polyester resin (B-1) and the hydrophobic silica (S-2) was used instead of the hydrophobic silica (S-1). In the same manner as in Production Example 1, toner (a-4) was obtained. Table 1 shows the physical properties of the obtained toner.

<Toner Production Example 21>
In Toner Production Example 1, styrene acrylic resin (b-5) instead of polyester resin (B-1), ester wax (W-4) instead of paraffin wax (W-1), hydrophobic silica (S-1) The toner (a-5) was obtained in the same manner as in Toner Production Example 1 except that hydrophobic silica (S-2) was used instead of (). Table 1 shows the physical properties of the obtained toner.

<Toner Production Example 22>
In Toner Production Example 1, styrene acrylic resin (b-6) instead of polyester resin (B-1), ester wax (W-5) instead of paraffin wax (W-1), hydrophobic silica (S-1) ) Was used in the same manner as in Toner Production Example 1 except that hydrophobic silica (S-2) was used instead of hydrophobic silica (S-2) to obtain toner (a-6). Table 1 shows the physical properties of the obtained toner.

<Toner Production Example 23>
In Toner Production Example 1, styrene acrylic resin (B-8) instead of polyester resin (B-1), ester wax (W-5) instead of paraffin wax (W-1), hydrophobic silica (S-1) ) Was used in the same manner as in Toner Production Example 1 except that hydrophobic silica (S-2) was used instead of hydrophobic silica (S-2) to obtain toner (a-7). Table 1 shows the physical properties of the obtained toner.

<Example of production of magnetic fine particle dispersed resin carrier>
Magnetic fine particle-dispersed resin cores were produced using the materials shown below.
-Phenol 10 parts by mass-Formaldehyde solution (37% by mass aqueous solution) 6 parts by mass-Magnetite particles 76 parts by mass-Hematite particles 8 parts by mass The above materials, 5% by mass 28% ammonia water, and 10 parts by mass water are placed in a flask. While stirring and mixing, the temperature was raised to 85 ° C. for 30 minutes and the mixture was allowed to undergo polymerization reaction for 3 hours to be cured. Then, after cooling to 30 degreeC and adding water, the supernatant liquid was removed, the precipitate was washed with water, and then air-dried. Subsequently, this was dried under reduced pressure (5 hPa or less) at a temperature of 60 ° C. to obtain a magnetic fine particle-dispersed resin core in which magnetic fine particles were dispersed.

  Subsequently, 3 parts by mass of a methyl methacrylate macromer having an ethylenically unsaturated group at one end and a weight average molecular weight of 5,000, 46 parts by mass of a monomer having the following compound (C) as a unit, and 51 parts by mass of methyl methacrylate were refluxed. The mixture was added to a four-necked flask equipped with a condenser, a thermometer, a nitrogen suction tube, and a mixing type stirring apparatus. Furthermore, 100 parts by mass of toluene, 100 parts by mass of methyl ethyl ketone, and 2.4 parts by mass of azobisisovaleronitrile were added and kept at 80 ° C. for 10 hours under a nitrogen stream to obtain a graft copolymer solution (solid content 35% by mass).

  0.7 parts by mass of melamine resin (number average particle diameter 0.25 μm), carbon black (number average particle diameter 35 nm, DBP oil absorption 50 ml / 100 g) with respect to 30 parts by mass of the obtained graft copolymer solution. 2 parts by mass and 100 parts by mass of toluene were stirred with a homogenizer to obtain a coating material.

Subsequently, 100 parts by mass of the magnetic fine particle-dispersed resin core was stirred while continuously applying shear stress, and the coating material was gradually added, and the solvent was volatilized at 70 ° C. to perform resin coating on the core surface. . The resin-coated magnetic carrier particles were heat-treated with stirring at 100 ° C. for 2 hours, pulverized, and then classified with a sieve having an aperture of 76 μm. The average particle size was 35 μm, the specific resistance was 5.9 × 10 ⁹ Ω · A magnetic carrier having a cm, a true specific gravity of 3.6 g / cm ³ , a magnetization strength (σ1000) of 51.2 Am ² / kg, and a residual magnetization of 4.9 Am ² / kg was obtained.

<Example 1>
First, a developer was prepared. To 92 parts by mass of the magnetic carrier, 8 parts by mass of toner (A-1) was added and mixed by a tumbler mixer to obtain a developer.

  Next, a Canon full color copier IRC3220N remodeled machine was used as an evaluation machine. As a modification, the exposure unit was replaced with one capable of printing with no borders, the fixing speed was set to 190 mm / s, and a copying machine capable of outputting 40 sheets / minute was obtained. Further, the pressure roller of the fixing device is replaced with a belt, and both the heating roller and the pressure belt are extended by 20 mm in order to make the axial length of the roller correspond to the entire solid image. In addition, the width of the transfer device was expanded by 20 mm.

  Evaluation is N / N under normal temperature and normal humidity (23 ° C., 50% RH), N / L under normal temperature and low humidity (23 ° C., 5% RH), H / H under high temperature and high humidity (30 ° C., 80% RH) Thus, images and evaluation were performed up to 5000 sheets while supplying toner (A-1). The evaluation items and evaluation criteria are shown below. The obtained evaluation results are shown in Table 3.

[Evaluation item]
[Winding offset evaluation]
Before the endurance, the pressing force of the fixing device is set to 0.30 MPa, and an image (printing ratio: 10%) as shown in FIG. 8 is used as a recording material (coated paper (100 g / m ² paper)). And 20 plain sheets (64 g / m ² paper), and 20 images were printed out while adjusting the developing bias so that the toner loading on the recording material was 1.1 mg / cm ² . The winding offset level when 20 sheets were printed was evaluated according to the following criteria.
A: No winding offset occurs in both coated paper and plain paper.
B: No winding offset occurs on coated paper, and no more than two winding offsets occur on plain paper.
C: A winding offset occurs within 2 sheets of coated paper and 5 sheets of plain paper.
D: A winding offset of 5 or less on coated paper and 10 or less on plain paper occurs.
E: A winding offset of 6 sheets or more with coated paper and 11 sheets or more with plain paper occurs.

[Fixed scattering evaluation]
Next, fixing scattering was evaluated according to the following evaluation criteria for an image in which no winding offset occurred during the winding offset evaluation.
A: The image is scattered on the image, and the image is uniform and is a uniform solid image.
B: A slight disturbance of the toner layer at the leading edge of the solid image is observed in the loupe check, but this is a level that does not cause any problem in visual observation.
C: Disturbance of the toner layer at the front end of the solid image is observed by visual confirmation.
D: The toner at the leading edge of the solid image is slightly scattered, and the scattered toner appears on the image at the period of the fixing roller.
E: The toner layer is disturbed in the whole solid image, and the toner scattering is also severe.

[Evaluation of transferability (missing)]
Next, the pressing force of the fixing device was changed to 0.15 MPa, two sheets were passed through the line image as shown in FIG. 9, and transferability (missing) was evaluated according to the following evaluation criteria.
A: An image with high line reproducibility is not seen in the line image.
B: Slight hollowing is observed in the loupe check, but it is a level that is not a problem on visual observation.
C: In the thinnest line (line width: 0.1 mm) by visual confirmation, a void is observed.
D: On the next thin line (line width: 0.2 mm) by visual confirmation, a void is observed.
E: In the thickest line (line width: 0.3 mm) by visual confirmation, a void is observed.

[Fixing member contamination assessment]
Next, the pressing force of the fixing device remains at 0.15 MPa, and an image as shown in FIG. 10 (printing ratio: 10%) is used. As the recording material, plain paper (64 g / m ² paper) is used. While adjusting the developing bias so that the amount of the toner was 1.1 mg / cm ² , the toner was endured up to 5000 sheets while visually observing the fixing roller and the pressure belt every 500 sheets. The fixing member contamination was evaluated according to the following criteria.
A: No fouling of the fixing member is observed even after passing 5000 sheets.
B: After passing 5000 sheets, slight fouling of the fixing member is observed.
C: After 4000 sheets are passed, fusing member contamination is observed.
D: After 2000 sheets are passed, the fixing member is contaminated.
E: Fixing member contamination is observed after passing 500 sheets.

[Image density evaluation]
The density of the fixed image in FIG. 10 before and after the endurance was measured by a densitometer X-Rite500 type, and an average value of 6 points was taken as an image density.
A: Very good (1.50 or more)
B: Good (from 1.40 to less than 1.50)
C: Normal (1.30 or more and less than 1.40)
D: Slightly bad (1.20 or more, less than 1.30: lower limit of practical use level)
E: Bad (less than 1.20)

<Examples 2-6 , Reference Examples 7-8, Examples 9-10, Reference Examples 11-12, Examples 13-16 , Comparative Examples 1-7>
In Example 1, toners (A-2) to (A-16) and (a-1) to (a-7) as shown in Table 2 were used instead of the toner (A-1). Except for the above, image output and evaluation were carried out in the same manner as in Example 1. The evaluation results are shown in Tables 3-4.

It is a schematic diagram showing an example of an image forming apparatus using the image forming method of the present invention. It is a schematic diagram showing an example of an image forming apparatus using the image forming method of the present invention. It is a schematic diagram showing an example of an image forming apparatus using the image forming method of the present invention. It is a schematic diagram showing an example of an image forming apparatus using the image forming method of the present invention. 1 is a schematic diagram illustrating an example of a full-color image forming apparatus using an image forming method of the present invention. It is a schematic diagram which shows an example of the grinding | pulverization apparatus used for this invention. It is a schematic diagram which shows an example of the surface modification apparatus used for this invention. It is explanatory drawing of the image used for winding offset evaluation. It is explanatory drawing of the image used for transferability evaluation. It is explanatory drawing of the image used for fixing member contamination evaluation.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Electrophotographic photoreceptor 2 Charging device 3 Exposure device 4 Developing device 5 Transfer device 6 Fixing device

Claims (4)

A charging step for charging the electrostatic latent image carrier, an electrostatic latent image forming step for forming an electrostatic latent image on the charged electrostatic latent image carrier, and developing the electrostatic latent image with a developer containing toner. A developing step for forming a toner image on the electrostatic latent image carrier, a transfer step for electrostatic transfer of the toner image formed on the electrostatic latent image carrier to the recording material, and a toner on the recording material. In an image forming method having at least a fixing step of fixing an image by heating,
i) In the image forming method, a toner image is formed on the electrostatic latent image carrier so that at least one of the main scanning direction and the sub-scanning direction is longer than the length of the recording material, and the toner image is recorded. To be transferred to the material,
ii) The toner has toner particles containing at least a binder resin, a colorant and a release agent, and inorganic fine particles,
The toner particles are obtained by pulverizing a colored resin composition obtained by melt-kneading at least a binder resin, a colorant, and a release agent.
The toner is
a) Storage elastic modulus G ′ (140 ° C.) at 140 ° C. of 1.0 × 10 ³ dN / m ² or more and less than 1.0 × 10 ⁵ dN / m ² b) UV transmittance of 45 to 45 % MeOH aqueous solution is 31 to 61 %
c) Compression degree C obtained from the following formula (1) is 38 to 56%.
Compression degree C (%) = 100 × (PA) / P (1)
(In the formula, A is the loose apparent density (g / cm ³ ), and P is the firm apparent density (g / cm ³ ).)
An image forming method characterized by that.   The image forming method according to claim 1, wherein the toner has an average circularity of 0.920 to 0.970. The image forming method according to claim 1, wherein the toner contains a polyester unit as a main component of the binder resin. Fixing pressure in the fixing process, the image forming method according to any one of claims 1 to 3, characterized in that a 0.03 to 0.30 MPa.

Images