JP3680661B2 - Image forming method - Google Patents

Description

【０１０４】
【発明の効果】
本発明は、上記の構成を採用することにより、平滑性、透明性、混色性、発色性に優れた定着画像の形成が可能になり、かつ、非定着シートの剥離性、耐ＨＯＴ性（ホットオフセット性）にも優れ、信頼性の高い画像の形成を可能にした。特に、フルカラー画像の形成において高画質で信頼性の高い画像を容易にかつ簡便に形成することのできるようになった。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for forming an image by developing an electrostatic latent image by an electrophotographic method using toner for developing an electrostatic image.
[0002]
[Prior art]
A method of visualizing image information through an electrostatic charge image, such as electrophotography, is currently widely used in various fields. In the electrophotographic method, an electrostatic image is formed on a photoreceptor through a charging process, an exposure process, and the like, developed with a developer, transferred, fixed, and visualized.
[0003]
As the developer used here, a two-component developer containing a toner and a carrier and a one-component developer containing a magnetic toner and a non-magnetic toner are known. The toner is usually produced by a melt-kneading pulverization method. In this kneading and pulverization method, a thermoplastic resin or the like is melt-kneaded together with a pigment, a charge control agent, a release agent such as wax, etc., and after cooling, the melt-kneaded material is finely pulverized and classified to produce desired toner particles. It is. The toner produced by the melt-kneading pulverization method is used by adding inorganic fine particles or organic fine particles to the surface for the purpose of improving fluidity and cleaning properties.
[0004]
The toner particles produced by the melt-kneading pulverization method are usually irregular in shape, and the surface composition is not uniform. Since the shape and surface composition of the toner particles slightly change depending on the pulverization property and pulverization conditions of the material used, it is difficult to control these intentionally. In particular, toner particles produced by a melt-kneading pulverization method using a material having high pulverization properties are subjected to mechanical forces such as various shearing forces inside the developing machine, and are further pulverized and pulverized, or the shape thereof is changed. Or As a result, in the two-component developer, finely divided toner particles adhere to the carrier surface, and the charge deterioration of the developer is accelerated. As a result, the toner particles are scattered, or the developing property is lowered with the change in the shape of the toner, thereby deteriorating the image quality.
[0005]
If the shape of the toner particles is indeterminate, sufficient fluidity cannot be secured even if the flow aid is added, and the fine particles of the flow aid move to the recesses of the toner particles by the mechanical force applied during use. In other words, there is a problem that the fluidity is lowered with time, and developability, transferability, cleaning property, etc. are deteriorated. Further, when such toner is collected by the cleaning process, returned to the developing machine, and reused, there is a problem that image quality is liable to deteriorate. In order to prevent these problems, it is conceivable to further increase the addition amount of the fluidity aid, but there arises a problem that black spots are generated on the photoreceptor or fluidity aid particles are scattered.
[0006]
On the other hand, in a toner formed by internally adding a release agent such as wax, the release agent may be exposed on the surface of the toner particles depending on the combination with the thermoplastic resin. In particular, a toner composed of a combination of a resin imparted with elasticity by a high molecular weight component, which is slightly pulverized, and a brittle wax such as polyethylene, exhibits much exposure of polyethylene on the surface. Such toner is advantageous for releasability at the time of fixing and cleaning of untransferred toner on the photoreceptor, but polyethylene on the surface of the toner particle is the surface of the toner particle by mechanical force such as shearing force in the developing machine. And then easily migrates to a developing roll, a photoconductor, a carrier and the like to contaminate them, resulting in a decrease in reliability as a developer.
[0007]
In addition, for example, JP-A-8-44111 and JP-A-8-286416 propose a suspension polymerization method. The suspension polymerization method is a method in which a polymerizable monomer is dispersed and suspended in an aqueous medium together with a colorant, a release agent, and the like, and the polymerizable monomer is polymerized to obtain toner particles. In this suspension polymerization method, for example, it is also possible to obtain toner particles having a multilayer structure in which a wax as a release agent is coated with a binder resin.
[0008]
However, this suspension polymerization method requires the particles to be adjusted to an appropriate size in the suspended state. For this purpose, it is necessary to stir the dispersion strongly and at high speed. In general, it is extremely difficult to uniformly stir a liquid having a viscosity like water at high speed. Inhomogeneous mixing liberates the release agent and generates a large amount of toner with a remarkably little or no release agent content, resulting in increased compositional unevenness among the toner particles and the required fixing of the toner. There is a problem in that various properties such as property and chargeability cannot be sufficiently satisfied.
[0009]
In recent years, an emulsion polymerization aggregation and fusion method has been proposed as a toner production method capable of intentionally controlling particle shape and surface composition. In this emulsion polymerization aggregation and fusion method, a resin dispersion is prepared by emulsion polymerization, a colorant dispersion in which a colorant is dispersed in a solvent, and a dispersion in which a release agent is dispersed. In this method, aggregated particles corresponding to the toner particle diameter are mixed to form toner particles, which are then fused by heating to obtain toner particles. In this emulsion polymerization aggregation and fusion method, the shape can be arbitrarily controlled by selecting the heating temperature condition, and the chargeability and durability can be improved.
[0010]
In such an electrophotographic process, in order to maintain stable performance of the toner even under various mechanical stresses, the surface hardness is controlled within a range that does not impair the exposure of the release agent to the toner surface or impair the fixability. It is necessary to increase the mechanical strength of the toner itself, and to satisfy both sufficient charging property and fixing property.
[0011]
In particular, along with the recent progress of color images, there is a significant tendency to reduce the diameter of toner in order to realize highly accurate images. However, with the simple reduction in size while maintaining the conventional particle size distribution, the presence of the fine powder side toner causes problems such as carrier and photoconductor contamination and toner scattering, and it is possible to simultaneously achieve high image quality and high reliability. Have difficulty. For this reason, it is necessary to sharpen the particle size distribution and to reduce the particle size. The aggregation / fusion coalescence method makes it possible to provide an excellent toner in these respects.
[0012]
In a full-color machine, since a desired color is reproduced by stacking color toners, the amount of toner used increases, and it is necessary to mix the toner sufficiently. In color mixing, it is essential to improve color reproducibility and OHP transparency.
Generally, a polyolefin-based wax is internally added to the release agent component for the purpose of preventing low temperature offset during fixing. At the same time, a small amount of silicone oil is uniformly applied to the fixing roller to improve the high temperature offset property. For this reason, silicone oil may adhere to the output transfer member, which may cause sticky discomfort.
[0013]
Therefore, an oilless fixing toner in which a large amount of a release agent component is included in the toner has been proposed. However, the addition of a large amount of the release agent is useful to some extent for improving the peelability, but the binder component and the release agent component are compatible, and the release agent cannot be oozed out uniformly and stably. Peeling stability is difficult to obtain. In addition, the free component of the release agent may cause charging inhibition.
Further, when the dispersibility of the pigment in the toner is lowered, it interacts with the release agent to form a pigment aggregate, which causes problems such as OHP transparency inhibition and color development inhibition.
[0014]
In order to improve the peelability of the fixing sheet, a method has been proposed in which a crosslinking component is added to the binder resin to improve the cohesive force. However, since the melt viscosity of the binder resin increases, the smoothness of the fixed image surface As a result, the glossiness and OHP transparency of the fixed image are deteriorated, and there is a possibility that sufficient color mixing property cannot be obtained in a full-color image.
[0015]
In addition, a method has been proposed to improve the cohesive strength of the binder resin by adding a high molecular weight component, but because the entanglement density of the binder resin was not controlled by adjusting the amount of the crosslinking agent, the releasability It has been difficult to achieve both OHP transparency and stability.
[0016]
[Problems to be solved by the invention]
The present invention eliminates the above-mentioned problems and enables formation of an image excellent in smoothness, transparency, color mixing, and color development when forming an image on a transparent transfer member, and peeling of a non-fixed sheet It is an object of the present invention to provide a method for forming an image having excellent image quality and HOT resistance (hot offset property), and having high image quality and high reliability.
[0017]
[Means for Solving the Problems]
  As a result of intensive studies to solve the above-mentioned problems, the present inventors have made the solution possible by adopting the following means.
  (1) In the image forming method including the step of forming a latent image on the electrostatic latent image holding member, the step of developing the latent image with a developer, and the step of fixing the developed image on the transparent transfer member, the transparent The transfer body has a resin layer on the surface, and the developer is crosslinked by at least one of the crosslinking agents represented by the following general formula.TheUsing a toner containing a binder resin and a colorant, the toner has a crosslink density Me of 1.6 × 10 6 determined by a temperature dispersion measurement method in dynamic viscoelasticity.^-8~ 3.5 × 10^-6An image forming method, wherein the glossiness Gs of the fixing surface is 80% or more when melted and fixed on the transparent transfer member.
  H₂C = CR-CO-O-Xn-CO-CR = CH₂
  (In the formula, n is an integer of 3 to 15, and X is CH.₂Or CH₂CH₂O and R are H or CH₃Represents. )
  H₂C = CR-CO-O-Xn-CH₂CH₂O-CO-CR = CH₂
  (In the formula, n is an integer of 4 to 14, and X is CH.₂, R is H or CH₃Represents. )
[0018]
(2) The image forming method as described in (1) above, wherein the colorant is at least one of yellow, magenta and cyan.
  (3) The image forming method as described in (1) or (2) above, wherein an average particle diameter of the colorant in the toner is 0.5 μm or less.
  (4) The image forming method as described in any one of (1) to (3) above, wherein the toner is produced by an aggregation / fusion / unification method.
(5) The image forming method as described in any one of (1) to (4) above, wherein the toner contains at least one release agent.
[0019]
  (6) The above (1) to (5), wherein the transparent transfer body is a transparent film containing a polyester polymer, a styrene / acrylic polymer, a polyamide polymer, a polyimide polymer, or the like. The image forming method according to any one of the above.
(7) The resin layer of the transparent transfer body has a weight average molecular weight of not less than 30,000, preferably in the range of 30,000 to 1,000,000, such as styrene / acrylic copolymer, polyester copolymer, vinyl chloride copolymer. The image forming method as described in any one of (1) to (6) above, which comprises a polymer, a vinyl acetate copolymer and the like.
(8) The image forming method according to any one of (1) to (7), wherein the fixing is oilless fixing.
(9) The image forming method according to any one of (1) to (8), wherein in the fixing step, a fixing temperature is adjusted to a range of 80 to 200 ° C.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
The present invention provides an image forming method including a step of forming a latent image on an electrostatic latent image holding member, a step of developing the latent image with a developer, and a step of fixing the developed image on a transparent transfer member. The crosslink density Me of the toner obtained by the temperature dispersion measurement method in dynamic viscoelasticity is 1.6 × 10^-8~ 3.5 × 10^-6A proper cross-linking (entanglement) structure of the resin of the fixed image is ensured by forming a fixed image having a glossiness of Gs of 80% or more on a transparent transfer body having a resin layer on the surface using a toner of / Kmol. Can suppress the decrease in hot offset property, maintain moderate mobility of resin molecular chains, and improve the smoothness of the image surface, improving the transparency, color development, and color mixing of fixed images. It has become possible to obtain high image quality. This was particularly effective for full-color images. Crosslink density Me is 3.5 × 10^-6If it exceeds / Kmol, low-temperature fixing tends to be difficult and gloss cannot be obtained.
[0021]
The toner used in the present invention can be produced, for example, by the following method. That is, at least a resin particle dispersion in which resin particles are dispersed and a colorant dispersion in which a colorant is dispersed are mixed, and an inorganic metal having a bivalent or higher charge dissolved in the dispersion medium of the mixture. A coagulant containing salt is added to agglomerate the resin particles and the colorant to prepare an aggregated particle dispersion in which the aggregated particles are dispersed. Thereafter, a release agent particle dispersion obtained by dispersing release agent particles as necessary, and a fine particle dispersion of other components may be added alone or mixed to add release agent particles to the surface of the aggregated particles and Fine particles are attached, and then heated and fused to a temperature equal to or higher than the glass transition point of the resin particles to form toner particles.
[0022]
In the above manufacturing method, before the heat fusion step, a resin particle dispersion is further added as necessary, and after adhering the resin particles to the surface of the aggregated particles and adjusting the adhered particle dispersion, heat fusion is performed. It is preferable to form toner particles.
[0023]
In the aggregation step, the mixed resin particles and the colorant are aggregated by heteroaggregation to form aggregated particles. In the fusing step, toner particles are formed including colorant particles, resin particles, release agent particles, and the like. In the attaching step, the core-shell structure can be formed by uniformly attaching the resin particles to the surface of the aggregated particles as mother particles in the dispersion.
[0024]
In the production of the toner of the present invention, examples of the resin used in the resin particle dispersion include thermoplastic resins. Specifically, styrenes such as styrene, parachlorostyrene, and α-methylstyrene are used alone. Polymer or copolymer (styrene resin); methyl acrylate, ethyl acrylate, n-propyl acrylate, n-butyl acrylate, lauryl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, Homopolymers or copolymers of vinyl groups such as n-propyl methacrylate, lauryl methacrylate and 2-ethylhexyl methacrylate (vinyl resins); single weights of vinyl nitriles such as acrylonitrile and methacrylonitrile Polymer or copolymer (vinyl resin); vinyl methyl ether, vinyl Homopolymers or copolymers of vinyl ethers such as ruisobutyl ether (vinyl resins); Homopolymers or copolymers of vinyl methyl ketone, vinyl ethyl ketone, vinyl isopropenyl ketones (vinyl resins); ethylene, Homopolymers or copolymers of olefins such as propylene, butadiene, and isoprene (olefin resins); non-vinyl condensation resins such as epoxy resins, polyester resins, polyurethane resins, polyamide resins, cellulose resins, and polyether resins; and Examples thereof include graft polymers of these non-vinyl condensation resins and vinyl monomers. These resins may be used alone or in combination of two or more.
[0025]
The average particle size of the resin particles in the resin particle dispersion is usually 1 μm or less, preferably 0.01 to 1 μm. When the average particle diameter exceeds 1 μm, the particle size distribution of the finally obtained electrostatic image developing toner is broadened, or free particles are generated, which tends to deteriorate the performance and reliability of the toner. When the average particle size is within the above range, the above disadvantages are eliminated, the uneven distribution among the toners is reduced, the dispersion in the toners is improved, and the variation in performance and reliability is advantageously reduced. The average particle diameter can be measured using, for example, a Coulter counter.
[0026]
In the toner used in the present invention, it is desirable to add a crosslinking agent component in order to impart flexibility to the resin. Specifically, a bifunctional monomer having the following general formula is preferable.
H₂C = CR-CO-O-Xn-CO-CR = CH₂
(In the formula, n is an integer of 3 to 15, and X is CH.₂Or CH₂CH₂O and R are H or C H_ThreeRepresents. )
H₂C = CR-CO-O-Xn-CH₂CH₂O-CO-CR = CH₂
(In the formula, n is an integer of 4 to 14, and X is CH.₂, R is H or CH_ThreeRepresents. )
The amount of the crosslinking agent component added is preferably in the range of 0.1 to 1.5% by weight based on the weight of the resin. If it is less than 0.1% by weight, the chargeability is improved, but a crosslinked structure is hardly obtained, and the hot offset property may be deteriorated. On the other hand, if it exceeds 1.5% by weight, the fixability is greatly impaired.
[0027]
The crosslinking agent (bifunctional monomer) that can be used in the present invention is not particularly limited as long as it is represented by the above general formula. For example, ethylene diacrylate, ethylene dimethacrylate, diethylene glycol diacrylate, Diethylene glycol methacrylate, triethylene glycol diacrylate, triethylene glycol dimethacrylate, decaethylene glycol diacrylate, decaethylene glycol dimethacrylate, pentaethylene glycol diacrylate, pentaethylene glycol dimethacrylate, pentacontactor diacrylate, dimataacrylic acid Examples include pentacontahector, decanediol diacrylate, and decanediol dimethacrylate.
[0028]
The cross-linked structure (entangled structure) in the present invention is obtained by measuring storage elastic modulus G ′, loss elastic modulus G ″, and loss tangent tan δ by dynamic viscoelasticity measurement (temperature dispersion measurement) by a sinusoidal vibration method.
Specifically, the toner is formed into a tablet, set on a parallel plate having an 8 mm diameter, and after normal force is set to 0, vibration is applied at a vibration frequency of 1 rad / sec. The measurement starts at 40 ° C and continues to 200 ° C. The measurement time interval is 120 seconds, and the rate of temperature increase after the start of measurement is 1 ° C./min. During the measurement, the strain amount is appropriately maintained at each measurement temperature, and adjusted appropriately so that an appropriate measurement value can be obtained.
[0029]
  When a rubbery flat region (plateau region) is observed, the apparent crosslink density is calculated from the following equation using the value of the storage elastic modulus G ′ at the center temperature, and this is used as the crosslink density Me of the present invention. .
    Me = G ′ / 3φRT
(Where φ is the front factor, Me: Apparent crosslink density, R: Gas constant, T: Temperature,G ':Storage modulus of rubbery area
[0030]
In general, the crosslinking (entanglement) of the molecular chain of the binder resin inside the toner affects the magnitude of the cohesive force of the binder resin itself. That is, the formation of the cross-linking (entanglement) restricts the freedom of movement of the molecular chain itself of the binder, thereby increasing the rigidity of the binder resin itself and decreasing the meltability of the binder resin itself. This increase in cross-linking (entanglement) improves the hot offset resistance at the time of fixing, but greatly reduces the glossiness of the image on an OHP sheet or the like.
[0031]
The toner used in the present invention has a crosslink density of 1.6 × 10 6.^-8~ 3.5 × 10^-6/ Kmol, preferably 2.0 × 10^-8~ 3.2 × 10^-6/ Kmol is suitable, and the crosslink density is 1.6 × 10^-8If it is less than / Kmol, since a substantial cross-linked structure is not formed, the hot offset property decreases, and 3.5 × 10^-6If it exceeds / Kmol, the mobility of the molecular chain of the binder resin itself is inhibited, so the meltability of the binder resin is lowered, the smoothness and glossiness of the fixed image is deteriorated, and the transparency in the OHP sheet is lowered. There is a case.
[0032]
Examples of the colorant for the toner used in the present invention include carbon black, chrome yellow, hansa yellow, benzidine yellow, sren yellow, quinoline yellow, permanent orange GTR, pyrazolone orange, vulcan orange, watch young red, permanent red, and brilliant. Carmine 3B, Brilliant Carmine 6B, Dupont Oil Red, Pyrazolone Red, Risor Red, Rhodamine B Lake, Lake Red C, Rose Bengal, Aniline Blue, Ultramarine Blue, Calco Oil Blue, Methylene Blue Chloride, Phthalocyanine Blue, Phthalocyanine Green, Malachite Green Pigments such as oxalate; acridine, xanthene, azo, benzoquinone, azine, anthraquino System, dioxazine, thiazine, azomethine, indigo, thioindigo, phthalocyanine, aniline black, polymethine, triphenylmethane dyes, diphenylmethane dyes, thiazole-based, include dyes such as xanthene. These colorants may be used alone or in combination of two or more.
[0033]
The average particle diameter of the colorant particles in the colorant particle dispersion is 1.0 μm or less, preferably 0.01 to 0.5 μm. When the average particle diameter exceeds 1.0 μm, the particle size distribution of the toner becomes too wide, and free particles are generated, which tends to cause deterioration in performance and reliability. When the average particle size is within the above range, the above disadvantages are eliminated, uneven distribution among the toners is reduced, dispersion in the toner is improved, and variations in performance and reliability are advantageously reduced. In addition, the said average particle diameter can be measured using a laser diffraction type particle size distribution measuring machine etc., for example.
The average particle diameter of the colorant in the toner is 0.5 μm or less, preferably 0.01 to 0.4 μm. Beyond this range, problems occur in the color developability, color reproducibility, and OHP transparency of the fixed image. This average particle diameter can be measured, for example, with a transmission electron microscope (TEM).
[0034]
The toner release agent used in the present invention preferably has poor compatibility with the binder resin. When the compatibility is high, the binder resin is easily plasticized by the release agent, and the viscosity of the toner is lowered at the time of high-temperature fixing, and offset is likely to occur, or the resin particles existing on the toner surface are plasticized to form glass on the toner surface. It lowers the transition point and deteriorates the fluidity of the toner.
[0035]
Examples of the release agent include low molecular weight polyolefins such as polyethylene, polypropylene, and polybutene; silicones having a softening point by heating; fatty acid amides such as oleic acid amide, erucic acid amide, ricinoleic acid amide, and stearic acid amide; Plant waxes such as uba wax, rice wax, candelilla wax, tree wax, jojoba oil; animal waxes such as beeswax; minerals and petroleum such as montan wax, ozokerite, ceresin, paraffin wax, microcrystalline wax, Fischer-Tropsch wax Waxes; ester waxes of higher alcohols and higher alcohols such as stearyl stearate and behenyl behenate; butyl stearate, propyl oleate, glyceryl monostearate, distearin Ester waxes of higher fatty acids such as glycerides and pentaerythritol tetrabehenate and unit or polyhydric lower alcohols; higher fatty acids such as diethylene glycol monostearate, dipropylene glycol distearate, distearic diglyceride and tetrastearic acid triglyceride Ester waxes composed of polyhydric alcohol multimers; sorbitan higher fatty acid ester waxes such as sorbitan monostearate; cholesterol higher fatty acid ester waxes such as cholesteryl stearate, etc., and these may be used alone. Two or more kinds may be used in combination.
[0036]
The average particle size of the release agent particles in the release agent particle dispersion is 1.0 μm or less, preferably 0.01 to 1.0 μm. When the average particle size exceeds 1.0 μm, the particle size distribution of the toner becomes too wide, and free particles are generated, which easily deteriorates performance and reliability. When the average particle size is within the above range, the above disadvantages are eliminated, and uneven distribution among the toners is reduced, dispersion in the toners is improved, and variations in performance and reliability are advantageously reduced. In addition, the said average particle diameter can be measured using a laser diffraction type particle size distribution measuring device, a centrifugal particle size distribution measuring device, etc., for example.
[0037]
The release agent particles are dispersed in an aqueous medium such as water together with a polymer electrolyte such as an ionic surfactant, a polymer acid, and a polymer base, and can be heated to a temperature higher than the melting point to apply a strong shearing force. When processed using a homogenizer or a pressure discharge type disperser, it can be easily adjusted to fine particles of 1.0 μm or less.
The binder resin constituting the resin particles of the toner is not particularly limited in combination with the colorant or the release agent, and can be freely selected as appropriate according to the purpose.
[0038]
The toner of the present invention includes an internal additive, a charge control agent, an inorganic powder, an organic powder in a resin particle dispersion, a colorant dispersion, a release agent dispersion and / or a mixed dispersion thereof depending on the purpose. It is possible to disperse other components (particles) such as bodies, lubricants, and abrasives. Examples of the internal additive that can be used include metals such as ferrite, magnetite, reduced iron, cobalt, manganese, and nickel, alloys, and magnetic materials such as compounds containing these metals.
[0039]
As the charge control agent, for example, a quaternary ammonium salt compound, a nigrosine compound, a dye composed of a complex of aluminum, iron, chromium, a triphenylmethane pigment, or the like can be used. The charge control agent in the present invention is preferably made of a material that is difficult to dissolve in water in order to control the ionic strength that affects the stability at the time of aggregation or fusion and to prevent contamination of wastewater.
[0040]
As the inorganic powder, for example, all particles usually used as an external additive on the toner surface such as silica, titania, calcium carbonate, magnesium carbonate, tricalcium phosphate, cerium oxide can be used.
As the organic powder, for example, all particles usually used as an external additive on the surface of the toner, such as vinyl resin, polyester resin, and silicone resin, can be used.
These inorganic powders and organic powders can also be used as fluidity aids and cleaning aids.
[0041]
Examples of the lubricant include fatty acid amides such as ethylene bisstearyl amide and oleic acid amide, and fatty acid metal salts such as zinc stearate and calcium stearate.
As said abrasive | polishing agent, the above-mentioned silica, alumina, cerium oxide etc. are mentioned, for example.
[0042]
The average particle size of the other components is 1.0 μm or less, preferably 0.01 to 1.0 μm. When the average particle size exceeds 1.0 μm, the particle size distribution of the toner is excessively widened to generate free particles, which easily deteriorates performance and reliability. When the average particle size is within the above range, the above disadvantages are eliminated, the uneven distribution between the toners is reduced, the dispersion in the toner is improved, and the variation in performance and reliability is advantageous. In addition, the said average particle diameter can be measured using a laser diffraction type particle size distribution measuring device, a centrifugal particle size distribution measuring device, etc., for example.
[0043]
When the resin particle dispersion, the colorant dispersion, and the release agent dispersion are mixed, the content of the colorant is suitably 50% by weight or less, preferably 2 to 40% by weight.
The content of the release agent is also 50% by weight or less, preferably 2 to 40% by weight.
Further, the content of the other components only needs to be a level that does not hinder the object of the present invention, and is generally very small, specifically in the range of 0.01 to 5% by weight, preferably 0.00. A range of 5 to 2% by weight is suitable.
[0044]
Examples of the dispersion medium of the resin particle dispersion, the colorant dispersion, the release agent dispersion, and the dispersion of other component particles include an aqueous medium. Examples of the aqueous medium include water such as distilled water and ion exchange water, alcohol, and the like. These may be used alone or in combination of two or more.
[0045]
Moreover, it is preferable to add and mix a surfactant in the aqueous medium. This surfactant is advantageous in ensuring the dispersion stability of the particles and the storage stability of the dispersion. It is also effective for the stability of the aggregated particles in the aggregation process. Examples of the surfactant include anionic surfactants such as sulfate ester, sulfonate, phosphate, and soap; cationic surfactants such as amine salt type and quaternary ammonium salt type; polyethylene Nonionic surfactants such as glycols, alkylphenol ethylene oxide adducts, polyhydric alcohols and the like can be mentioned. Among these, an ionic surfactant is preferable, and an anionic surfactant and a cationic surfactant are more preferable. The nonionic surfactant is preferably used in combination with an anionic surfactant or a cationic surfactant. The said surfactant may be used independently and may use 2 or more types together.
[0046]
Specific examples of anionic surfactants include fatty acid soaps such as potassium laurate, sodium oleate, and castor oil sodium; sulfates such as octyl sulfate, lauryl sulfate, lauryl ether sulfate, and nonyl phenyl ether sulfate; lauryl sulfonate Alkyl naphthalene sulfonate sodium such as dodecylbenzene sulfonate, triisopropyl naphthalene sulfonate, dibutyl naphthalene sulfonate, naphthalene sulfonate formalin condensate, monooctyl sulfosuccinate, dioctyl sulfosuccinate, lauric acid amide sulfonate, oleic acid amide sulfonate, etc. Sulfonates: lauryl phosphate, isopropyl phosphate, nonylphenyl ether phosphate Phosphoric acid esters such as Feto; dialkyl sulfosuccinate salts such as sodium dioctyl sulfosuccinate, such as sulfosuccinate salts such as sodium lauryl sulfosuccinate 2.
[0047]
Specific examples of the cationic surfactant include laurylamine hydrochloride, stearylamine hydrochloride, oleylamine acetate, stearylamine acetate, stearylaminopropylamine acetate, and other amine salts; lauryltrimethylammonium chloride, dilauryldimethylammonium Chloride, distearyl ammonium chloride, distearyl dimethyl ammonium chloride, lauryl dihydroxyethyl methyl ammonium chloride, oleyl bis polyoxyethylene methyl ammonium chloride, lauroyl aminopropyl dimethyl ethyl ammonium etosulphate, lauroyl aminopropyl dimethyl hydroxyethyl ammonium perchlorate, alkylbenzene dimethyl Ammonium chloride, alkyltri And quaternary ammonium salts such as chill ammonium chloride.
[0048]
Specific examples of the nonionic surfactant include alkyl ethers such as polyoxyethylene octyl ether, polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether; polyoxyethylene octyl phenyl ether, polyoxy Alkyl phenyl ethers such as ethylene nonyl phenyl ether; alkyl esters such as polyoxyethylene laurate, polyoxyethylene stearate, polyoxyethylene oleate; polyoxyethylene lauryl amino ether, polyoxyethylene stearyl amino ether, polyoxyethylene Alkylamines such as oleyl amino ether, polyoxyethylene soybean amino ether, polyoxyethylene beef tallow amino ether; Alkyl amides such as ethylene lauric acid amide, polyoxyethylene stearic acid amide, polyoxyethylene oleic acid amide; vegetable oil ethers such as polyoxyethylene castor oil ether and polyoxyethylene rapeseed oil ether; lauric acid diethanolamide, stearic acid Alkanolamides such as diethanolamide and oleic acid diethanolamide; sorbitan ester ethers such as polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monopalmitate, polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan monooleate Etc.
[0049]
In order to improve the dispersion stability of the colorant in the aqueous medium, a titanate coupling agent, rosin, a water-soluble polymer, etc. are used as a dispersion aid for lowering the energy of the colorant in the toner. be able to.
[0050]
Examples of the flocculant used in the aggregation step include inorganic metal salts having a charge of 2 or more. A general inorganic metal compound or a polymer thereof is used after being dissolved in a resin fine particle dispersion. The metal elements constituting the inorganic metal salt are 2A, 3A, 4A, 5A, 6A in the periodic table (long period table). , 7A, 8, 1B, 2B, and 3B, and has a charge of 2 or more, and dissolves in the form of ions in an agglomeration system of resin fine particles. Specific examples include metal salts such as calcium chloride, calcium nitrate, barium chloride, magnesium chloride, zinc chloride, aluminum chloride, and aluminum sulfate, and inorganic metal salt weights such as polyaluminum chloride, polyaluminum hydroxide, and calcium polysulfide. There are mergers. Among these, an aluminum salt and a polymer thereof are particularly preferable. In general, in order to obtain a sharper particle size distribution, even if the valence of the inorganic metal salt is 2 valences from 1 valence, 3 valences from 2 valences, 4 valences from 3 valences, the same valence, Inorganic metal salt polymers are more suitable.
[0051]
The content of the surfactant in the dispersion liquid may be a level that does not inhibit the present invention, and is generally small. Specifically, a range of 0.01 to 10% by weight, preferably 0.05 to 5% by weight, more preferably 0.1 to 2% by weight is appropriate. If the content is less than 0.01% by weight, dispersions such as resin particle dispersions, colorant dispersions, and release agent dispersions become unstable, causing agglomeration and stabilizing between particles during aggregation. Since the properties are different, there are problems such as the release of specific particles. On the other hand, if it exceeds 10% by weight, it is not preferable because the particle size distribution of the particles becomes too wide and it becomes difficult to control the particle size.
[0052]
There is no restriction | limiting in particular in the adjustment method of a resin particle dispersion, Although it can employ | adopt suitably according to the objective, For example, it can adjust as follows.
If the resin constituting the resin particles is a homopolymer or copolymer (vinyl resin) of vinyl monomers such as esters having vinyl groups, vinyl nitriles, vinyl ethers, vinyl ketones, etc., vinyl It is preferable to prepare a dispersion of vinyl monomer homopolymer or copolymer (vinyl resin) particles by conducting emulsion polymerization or seed polymerization in an ionic surfactant.
[0053]
When the resin constituting the resin particles is a resin other than the homopolymer or copolymer of the vinyl monomer, if the resin is dissolved in an oily solvent having a relatively low solubility in water, After the resin is dissolved in an oily solvent, it is added to water together with the ionic surfactant and polymer electrolyte, dispersed in fine particles using a disperser such as a homogenizer, and then heated or reduced in pressure, It is preferable to adjust by evaporating the solvent.
[0054]
The colorant dispersion can be adjusted, for example, by dispersing the colorant in an aqueous medium such as a surfactant.
The release agent dispersion is, for example, dispersed in water together with a polymer electrolyte such as an ionic surfactant, a polymer acid, or a polymer base, and then heated to a temperature higher than the melting point, while homogenizer or pressure discharge. By applying a strong shearing force using a mold disperser, the release agent can be made fine and adjusted.
[0055]
The particle dispersion liquid of other components can be adjusted by, for example, dispersing it in an aqueous medium such as a surfactant together with a colorant.
The dispersing means is not particularly limited, and known dispersing devices such as a rotary shearing homogenizer, a ball mill having media, a sand mill, and a dyno mill can be used.
[0056]
The toner of the present invention can increase the color image density by increasing the amount of pigment added in the toner, and a toner having a desired color tone can be obtained. Further, the pigment dispersibility in the toner is important for improving smoothness, transparency, color mixing, and color development in a transparent film image.
Unlike the case where the toner is produced by a kneading and pulverizing method, a toner having a small average particle size and a sharp particle size distribution can be obtained.
[0057]
The developer used in the present invention is not particularly limited except that it contains the toner described above, and appropriate components can be blended depending on the purpose. That is, the toner may be used alone to prepare as a one-component electrostatic image developer, or may be prepared as a two-component electrostatic image developer in combination with a carrier.
The carrier is not particularly limited, and for example, a known carrier such as a resin-coated carrier described in JP-A Nos. 62-39879 and 56-11461 can be used.
[0058]
Specific examples of the carrier include the following resin-coated carriers. That is, examples of the carrier core particles include ordinary iron powder, ferrite, and magnetite molding, and the average particle size is suitably in the range of 30 to 200 μm.
Examples of the carrier coating resin include styrenes such as styrene, parachlorostyrene, and α-methylstyrene, methyl acrylate, ethyl acrylate, n-propyl acrylate, lauryl acrylate, 2-ethylhexyl acrylate, and methacrylic acid. Α-methylene fatty acid monocarboxylic acids such as methyl, n-propyl methacrylate, lauryl methacrylate and 2-ethylhexyl methacrylate, nitrogen-containing acrylics such as dimethylaminoethyl methacrylate, vinylnitriles such as acrylonitrile and methacrylonitrile, 2 -Vinyl pyridines such as vinyl pyridine and 4-vinyl pyridine, vinyl ethers such as vinyl methyl ether and vinyl isobutyl ether, vinyl kets such as vinyl methyl ketone, vinyl ethyl ketone and vinyl isoprobenyl ketone. Tones, olefins such as ethylene and propylene, homopolymers such as vinyl-based fluorine-containing monomers such as vinylidene fluoride, tetrafluoroethylene and hexafluoroethylene, or copolymers composed of two or more monomers, and methyl Examples thereof include silicones such as silicone and methylphenyl silicone, polyesters containing bisphenol and glycol, epoxy resins, polyurethane resins, polyamide resins, cellulose resins, polyether resins, and polycarbonate resins. These resins may be used alone or in combination of two or more. The amount of the coating resin is suitably in the range of 0.1 to 10 parts by weight, preferably in the range of 0.5 to 3.0 parts by weight with respect to 100 parts by weight of the core particles.
[0059]
For the production of the carrier, a heating kneader, a heating Henschel mixer, a UM mixer, or the like can be used. Depending on the amount of the coating resin, a heating fluidized rolling bed, a heating kiln, or the like can be used.
The mixing ratio of the toner and the carrier in the developer is not particularly limited and can be appropriately selected depending on the purpose.
[0060]
The transparent transfer member used in the present invention may be a film of styrene / acrylic copolymer or polyester copolymer. The thickness of this film is suitably in the range of 0.1 to 0.2 mm.
Further, the transparent transfer body of the present invention includes a resin coating layer containing a resin having a weight average molecular weight of 30,000 or more, preferably 30,000 to 1,000,000. When the weight average molecular weight is less than 30,000, the resin coating layer is significantly melted at the time of fixing, resulting in a defective fixed image. Specific examples of the resin of the resin coating layer include styrene / acrylic polymers, polyester polymers, vinyl chloride polymers, vinyl acetate polymers, and the like. These are excellent in light transmittance, workability and the like. The thickness of this resin coating layer is in the range of 0.1 to 0.3 μm, preferably in the range of 0.1 to 0.2 μm.
[0061]
The image forming method of the present invention includes an electrostatic latent image forming step, a toner image forming step, a transfer step, and a cleaning step. Each process itself is a general process, and is described in, for example, Japanese Patent Laid-Open Nos. 56-40868 and 49-91231. The image forming method of the present invention can be carried out using an image forming apparatus such as a copier or a facsimile machine known per se.
[0062]
The electrostatic latent image forming step is a step of forming an electrostatic latent image on the electrostatic latent image carrier, and the toner image forming step is a toner image obtained by developing the electrostatic latent image with a developer layer on the developer carrier. Is a step of forming. The developer layer is not particularly limited as long as it contains the toner according to the present invention. The transfer process is a process of transferring the toner image onto the transfer body, and the cleaning process is a process of removing the electrostatic charge image developer remaining on the electrostatic latent image carrier.
[0063]
The fixing temperature at the time of fixing in the image forming process is desirably in the range of 80 to 200 ° C. If it is too low, the toner will not dissolve sufficiently and a good fixed image cannot be obtained. Moreover, when too high, problems, such as offset to a heat roll, will arise.
[0064]
【Example】
EXAMPLES Hereinafter, although an Example demonstrates this invention in more detail, this invention is not restrict | limited by these Examples. In the following, “part” means part by weight.
The glossiness of the transparent film on which the toner has been melt-fixed was measured using a gloss meter manufactured by Murakami Color Co., Ltd. The average particle size and the average volume particle distribution GSDv of the toner were measured using a Coulter counter (TA2 type, manufactured by Coulter). The average particle diameters of the resin particles, the colorant particles, and the release agent particles were measured using a laser diffraction particle size distribution analyzer (LA-700, manufactured by Horiba, Ltd.).
[0065]
The electrostatic image developer is evaluated by oilless fixing using a modified VIVECE400 machine manufactured by Fuji Xerox Co., Ltd., and image formation is performed at a fixing temperature of 160 ° C. The smoothness, transparency, and color developability of the resulting image. The color mixing property was visually evaluated.
The smoothness was determined to be poor if it was in a rough state due to unevenness or the like, and good when such a state was not observed.
Transparency was judged to be poor if the transmitted light was turbid, and good when such a state was not observed.
The color developability was poor when the intermediate color was thin, and good when it was clear.
The color mixing property was determined to be poor if the color overlap portion of two or more colors was cloudy, and good if clear.
For the hot offset property, an image was formed in the same manner as described above at a fixing temperature of 200 ° C., and the offset state of the obtained image was examined.
[0066]
-Preparation of resin particle dispersion (1)-
Styrene 350 parts
Butyl acrylate: 50 parts
Acrylic acid ... 8 parts
Carbon tetrabromide ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ 4 parts
(All are manufactured by Wako Pure Chemical Industries, Ltd.)
Cross-linking agent (manufactured by Shin-Nakamura Chemical; NK ester) ... 2 parts
H₂C = CR-CO-O- (CH₂)₉-OCH₂-CO-CH = CH₂
A solution was prepared by mixing and dissolving the above components. On the other hand, 8 parts of a nonionic surfactant (Sanyo Kasei Co., Ltd., Nonipol 8.5) and an anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd., Neogen SC) 7 parts dissolved in 585 parts ion-exchanged water, added with the above solution, dispersed and emulsified in a flask, and slowly mixed for 10 minutes, while ion-exchanged water in which 3 parts ammonium persulfate (manufactured by Wako Pure Chemical Industries) was dissolved After 50 parts were charged and nitrogen substitution was performed, the contents in the flask were heated with an oil bath until the contents reached 70 ° C. while stirring, and the emulsion polymerization was continued for 6 hours. Thereafter, the reaction solution was cooled to room temperature to prepare a resin particle dispersion. Subsequently, when a part of the resin particle dispersion was left on an oven at 80 ° C. to remove moisture and the properties of the residue were measured, the average particle size of the resin particles was 150 nm, the glass transition point was 57 ° C., The weight average molecular weight was 45,000.
[0067]
-Preparation of resin particle dispersion (2)-
Styrene 350 parts
Butyl acrylate: 50 parts
Acrylic acid ... 8 parts
Carbon tetrabromide ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ 4 parts
(All are manufactured by Wako Pure Chemical Industries, Ltd.)
Cross-linking agent (manufactured by Shin-Nakamura Chemical; NK ester) ... 10 parts
H₂C = CR-CO-O- (CH₂)₉-OCH₂-CO-CH = CH₂
A solution was prepared by mixing and dissolving the above components. On the other hand, 8 parts of a nonionic surfactant (Sanyo Kasei Co., Ltd., Nonipol 8.5) and an anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd., Neogen SC) 7 parts dissolved in 585 parts ion-exchanged water, added with the above solution, dispersed and emulsified in a flask, and slowly mixed for 10 minutes, while ion-exchanged water in which 3 parts ammonium persulfate (manufactured by Wako Pure Chemical Industries) was dissolved After 50 parts were charged and nitrogen substitution was performed, the contents in the flask were heated with an oil bath until the contents reached 70 ° C. while stirring, and the emulsion polymerization was continued for 6 hours. Thereafter, the reaction solution was cooled to room temperature to prepare a resin particle dispersion. Subsequently, when a part of the resin particle dispersion was left on an oven at 80 ° C. to remove moisture and the characteristics of the residue were measured, the average particle size of the resin particles was 145 nm, the glass transition point was 57 ° C., The weight average molecular weight was 47,000.
[0068]
-Preparation of resin particle dispersion (3)-
Styrene 350 parts
Butyl acrylate: 50 parts
Acrylic acid ... 8 parts
Carbon tetrabromide ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ 4 parts
(All are manufactured by Wako Pure Chemical Industries, Ltd.)
Cross-linking agent (manufactured by Shin-Nakamura Chemical; NK ester) ... 0.3 part
H₂C = CR-CO-O- (CH₂)₉-OCH₂-CO-CH = CH₂
A solution was prepared by mixing and dissolving the above components. On the other hand, 8 parts of a nonionic surfactant (Sanyo Kasei Co., Ltd., Nonipol 8.5) and an anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd., Neogen SC) 7 parts dissolved in 585 parts ion-exchanged water, added with the above solution, dispersed and emulsified in a flask, and slowly mixed for 10 minutes, while ion-exchanged water in which 3 parts ammonium persulfate (manufactured by Wako Pure Chemical Industries) was dissolved After 50 parts were charged and nitrogen substitution was performed, the contents in the flask were heated with an oil bath until the contents reached 70 ° C. while stirring, and the emulsion polymerization was continued for 6 hours. Thereafter, the reaction solution was cooled to room temperature to prepare a resin particle dispersion. Subsequently, when a part of the resin particle dispersion was left on an oven at 80 ° C. to remove moisture and the characteristics of the residue were measured, the average particle size of the resin particles was 140 nm, the glass transition point was 57 ° C., The weight average molecular weight was 43,000.
[0069]
―Preparation of colorant dispersion (1) ―
Phthalocyanine pigment: 70 parts
(Daiichi Seika Co., Ltd., PVFASTBLUE)
Anionic surfactant 3 parts
(Wako Pure Chemical Industries, Ltd.)
Bis (dioctylpyrophosphate) oxyacetate titanate
(Shin-Etsu Chemical Co., Ltd.) 3 parts
Ion-exchanged water ... 300 parts
The above components were mixed and dissolved, and dispersed using a homogenizer (manufactured by IKA, Ultra Tarrax) to prepare a cyan colorant dispersion (1) having an average particle size of 160 nm.
[0070]
―Preparation of colorant dispersion (2) ―
Magenta pigment ... 70 parts
(Daiichi Seika Co., Ltd., Kinacridon R122)
Anionic surfactant 3 parts
(Wako Pure Chemical Industries, Ltd.)
Ion-exchanged water ... 300 parts
The above components were mixed and dissolved, and dispersed using a homogenizer (manufactured by IKA, Ultra Tarrax) to prepare a cyan colorant dispersion (2) having an average particle size of 160 nm.
[0071]
-Preparation of colorant dispersion (3)-
Yellow pigment 70 parts
(Daiichi Seika Co., Ltd., Chromo Fine Yellow PY93)
Anionic surfactant 3 parts
(Wako Pure Chemical Industries, Ltd.)
Ion-exchanged water ... 300 parts
The above components were mixed and dissolved, and dispersed using a homogenizer (manufactured by IKA, Ultra Tarrax) to prepare a cyan colorant dispersion (3) having an average particle size of 160 nm.
[0072]
-Preparation of release agent particle dispersion-
100 parts of paraffin wax
(Nippon Seiwa Co., Ltd., HNP0190, melting point 90 ° C)
Anionic surfactant 3.5 parts
(Lion Corporation, Ripar 860K)
Ion-exchanged water ... 500 parts
The above components were mixed and dissolved, dispersed using a homogenizer (Ultra Turrax, manufactured by IKA), and then dispersed using a pressure discharge type homogenizer to prepare a release agent particle dispersion having an average particle size of 180 nm.
[0073]
[Example 1]
(Preparation of aggregated particle dispersion)
Resin particle dispersion (1) 300 parts
Colorant dispersion (1) 15 parts
Release agent particle dispersion ... 25 parts
Zinc chloride ... 1 part
Ion-exchanged water: 500 parts
The components were placed in a round stainless steel flask, dispersed using a homogenizer (IKA, Ultra Turrax T50), and then heated to 55 ° C. with stirring in an oil bath for heating. After maintaining at 55 ° C. for 30 minutes, observation with an optical microscope confirmed that aggregated particles having an average particle diameter of about 4.8 μm were formed.
[0074]
(Preparation of adherent particle dispersion)
To this agglomerated particle dispersion, 70 parts of the resin particle dispersion (1) was gently added, and the temperature of the heating oil bath was raised and maintained at 56 ° C. for 1 hour. When observed with an optical microscope, it was confirmed that adhered particles having an average particle diameter of about 5.4 μm were formed.
[0075]
(Fusion of adhered particles)
The pH at 56 ° C. of the adhered particle dispersion was measured and found to be 2.5. 1N NaOH aqueous solution was added to this dispersion to adjust the pH at 56 ° C. to 6.5, and the adhered particles were stabilized. Then, the mixture was heated to 95 ° C. while continuing stirring, and then maintained for 6 hours. Adherent particles were fused. The reaction product was filtered, sufficiently washed with ion exchange water, and then dried with a vacuum dryer to obtain toner particles.
[0076]
(Evaluation of toner particles)
The obtained toner particles had an average particle size of 5.4 μm and a GSDv of 1.23. To 100 parts of the toner particles, 1 part of colloidal silica (manufactured by Nippon Aerosil Co., Ltd., R972) was externally added and mixed using a Henschel mixer to obtain an electrostatic image developing toner.
The obtained toner crosslink density was measured by a dynamic viscoelasticity temperature dispersion measurement method.^-7/ Kmol. When the cross section of the toner particles was observed with a transmission electron microscope (TEM), the average particle diameter of the pigment particles was 300 nm.
[0077]
(Preparation of electrostatic charge image developer)
100 parts of ferrite particles (manufactured by Powdertech Co., Ltd., average particle size 50 μm) and 1.5 parts of a methacrylate resin (Mitsubishi Rayon Co., Ltd., molecular weight 95,000) are placed in a pressure kneader together with 500 parts of toluene, and then at room temperature for 15 minutes. After stirring and mixing, the temperature was raised to 70 ° C. while mixing under reduced pressure to distill off toluene, followed by cooling and classification using a 105 μm sieve to prepare a resin-coated carrier.
The resin-coated carrier and the toner were mixed to prepare a two-component electrostatic charge image developer having a toner concentration of 7% by weight.
[0078]
(Image evaluation)
Using this electrostatic charge image developer, an image was formed on a transparent film made of polyethylene terephthalate having a 0.2 μm thick resin layer of a styrene / methyl methacrylate copolymer having a weight average molecular weight of 50,000. As a result of the evaluation, the surface gloss, smoothness, color developability, color mixing, and transparency were good, and the glossiness Gs was 90%. The hot offset property was also good.
[0079]
[Example 2]
(Preparation of aggregated particle dispersion)
Resin particle dispersion (1) 300 parts
Colorant dispersion (2) 15 parts
Release agent particle dispersion ... 25 parts
Zinc chloride ... 1 part
Ion-exchanged water: 500 parts
The components were placed in a round stainless steel flask, dispersed using a homogenizer (IKA, Ultra Turrax T50), and then heated to 55 ° C. with stirring in an oil bath for heating. After maintaining at 55 ° C. for 30 minutes, observation with an optical microscope confirmed that aggregated particles having an average particle diameter of about 5.2 μm were formed.
[0080]
(Preparation of adherent particle dispersion)
To this agglomerated particle dispersion, 150 parts of the resin particle dispersion (1) was gently added, and the temperature of the heating oil bath was raised and maintained at 56 ° C. for 2 hours. When observed with an optical microscope, it was confirmed that adhered particles having an average particle diameter of about 5.7 μm were formed.
[0081]
(Fusion of adhered particles)
It was 3.0 when pH at 56 degrees C of the said adhesion particle dispersion was measured. 1N NaOH aqueous solution was added to this dispersion to adjust the pH at 56 ° C. to 8.0, and the adhering particles were stabilized. Then, the mixture was heated to 93 ° C. while stirring, and then maintained for 5 hours. Adherent particles were fused. The reaction product was filtered, sufficiently washed with ion exchange water, and then dried with a vacuum dryer to obtain toner particles.
[0082]
(Evaluation of toner particles)
The obtained toner particles had an average particle size of 5.6 μm and a GSDv of 1.21. To 100 parts of the toner particles, 1 part of colloidal silica (manufactured by Nippon Aerosil Co., Ltd., R972) was externally added and mixed using a Henschel mixer to obtain an electrostatic image developing toner.
The obtained toner crosslink density was measured by a dynamic viscoelastic temperature dispersion measurement method.^-7/ Kmol. When the cross section of the toner particles was observed with a transmission electron microscope (TEM), the average particle diameter of the pigment particles was 280 nm.
[0083]
(Preparation of electrostatic charge image developer)
100 parts of ferrite particles (manufactured by Powdertech Co., Ltd., average particle size 50 μm) and 1.5 parts of a methacrylate resin (Mitsubishi Rayon Co., Ltd., molecular weight 95,000) are placed in a pressure kneader together with 500 parts of toluene, and then at room temperature for 15 minutes. After stirring and mixing, the temperature was raised to 70 ° C. while mixing under reduced pressure to distill off toluene, followed by cooling and classification using a 105 μm sieve to prepare a resin-coated carrier.
The resin-coated carrier and the toner were mixed to prepare a two-component electrostatic charge image developer having a toner concentration of 7% by weight.
[0084]
(Image evaluation)
Using this electrostatic charge image developer, an image was formed on a transparent film made of polyethylene terephthalate having a 0.2 μm thick resin layer of a styrene / methyl methacrylate copolymer having a weight average molecular weight of 50,000. As a result of the evaluation, the surface gloss, smoothness, color development, color mixing, and transparency were good, and the glossiness Gs was 95%. The hot offset property was also good.
[0085]
Example 3
(Preparation of aggregated particle dispersion)
Resin particle dispersion (1) ... 300 parts
Colorant dispersion (3) 15 parts
Release agent dispersion ・ ・ ・ ・ ・ ・ ・ ・ ・ 25 parts
Polyaluminum hydroxide: 1 part
(Pho2S manufactured by Asada Chemical Co., Ltd.)
Ion-exchanged water ... 500 parts
The components were placed in a round stainless steel flask, dispersed using a homogenizer (IKA, Ultra Turrax T50), and then heated to 55 ° C. with stirring in an oil bath for heating. After maintaining at 55 ° C. for 30 minutes, observation with an optical microscope confirmed that aggregated particles having an average particle diameter of about 5.9 μm were formed.
[0086]
(Preparation of adherent particle dispersion)
To this agglomerated particle dispersion, 50 parts of the resin particle dispersion (1) was gently added, and the temperature of the heating oil bath was raised and maintained at 56 ° C. for 2 hours. When observed with an optical microscope, it was confirmed that adhered particles having an average particle diameter of about 6.1 μm were formed.
[0087]
(Fusion of adhered particles)
The pH at 56 ° C. of the adhered particle dispersion was measured and found to be 2.7. A 1N NaOH aqueous solution was added to this dispersion to adjust the pH at 56 ° C. to 8.0, and the adhered particles were stabilized. Then, the mixture was heated to 93 ° C. while continuing stirring, and then maintained for 7 hours. Adherent particles were fused. The reaction product was filtered, sufficiently washed with ion exchange water, and then dried with a vacuum dryer to obtain toner particles.
[0088]
(Evaluation of toner particles)
The obtained toner particles had an average particle size of 5.1 μm and a GSDv of 1.19. To 100 parts of the toner particles, 1 part of colloidal silica (manufactured by Nippon Aerosil Co., Ltd., R972) was externally added and mixed using a Henschel mixer to obtain an electrostatic image developing toner.
When the crosslink density of the obtained toner was measured by a dynamic viscoelasticity temperature dispersion measurement method, 5.4 × 10 5 was obtained.^-7/ Kmol. When the cross section of the toner particles was observed with a transmission electron microscope (TEM), the average particle diameter of the pigment particles was 340 nm.
[0089]
(Preparation of electrostatic charge image developer)
100 parts of ferrite particles (manufactured by Powdertech Co., Ltd., average particle size 50 μm) and 1.5 parts of a methacrylate resin (Mitsubishi Rayon Co., Ltd., molecular weight 95,000) are placed in a pressure kneader together with 500 parts of toluene, and then at room temperature for 15 minutes. After stirring and mixing, the temperature was raised to 70 ° C. while mixing under reduced pressure to distill off toluene, followed by cooling and classification using a 105 μm sieve to prepare a resin-coated carrier.
The resin-coated carrier and the toner were mixed to prepare a two-component electrostatic charge image developer having a toner concentration of 7% by weight.
[0090]
(Image evaluation)
Using this electrostatic charge image developer, an image was formed on a transparent film made of polyethylene terephthalate having a 0.2 μm thick resin layer of a styrene / methyl methacrylate copolymer having a weight average molecular weight of 50,000. As a result, the surface gloss, smoothness, color developability, color mixing, and transparency were good, and the glossiness Gs was 83%. The hot offset property was also good.
[0091]
[Comparative Example 1]
(Preparation of aggregated particle dispersion)
Resin particle dispersion (2) 300 parts
Colorant dispersion (2) 15 parts
Release agent dispersion ・ ・ ・ ・ ・ ・ ・ ・ ・ 25 parts
Zinc chloride ... 1 part
Ion-exchanged water ... 500 parts
The components were placed in a round stainless steel flask, dispersed using a homogenizer (IKA, Ultra Turrax T50), and then heated to 55 ° C. with stirring in an oil bath for heating. After maintaining at 55 ° C. for 30 minutes, observation with an optical microscope confirmed that aggregated particles having an average particle diameter of about 4.8 μm were formed.
[0092]
(Preparation of adherent particle dispersion)
To this agglomerated particle dispersion, 70 parts of the resin particle dispersion (2) was gently added, and the temperature of the heating oil bath was raised and maintained at 56 ° C. for 1 hour. When observed with an optical microscope, it was confirmed that adhered particles having an average particle diameter of about 5.4 μm were formed.
[0093]
(Fusion of adhered particles)
The pH at 56 ° C. of the adhered particle dispersion was measured and found to be 2.5. 1N NaOH aqueous solution was added to this dispersion to adjust the pH at 56 ° C. to 6.0, and the adhered particles were stabilized. Then, the mixture was heated to 93 ° C. while continuing stirring, and then maintained for 5 hours. Adherent particles were fused. The reaction product was filtered, sufficiently washed with ion exchange water, and then dried with a vacuum dryer to obtain toner particles.
[0094]
(Evaluation of toner particles)
The obtained toner particles had an average particle size of 5.1 μm and a GSDv of 1.19. To 100 parts of the toner particles, 1 part of colloidal silica (manufactured by Nippon Aerosil Co., Ltd., R972) was externally added and mixed using a Henschel mixer to obtain an electrostatic image developing toner.
The crosslink density of the obtained toner was measured by a dynamic viscoelasticity temperature dispersion measurement method.^-Five/ Kmol. When the cross section of the toner particles was observed with a transmission electron microscope (TEM), the average particle diameter of the pigment particles was 360 nm.
[0095]
(Preparation of electrostatic charge image developer)
100 parts of ferrite particles (manufactured by Powdertech Co., Ltd., average particle size 50 μm) and 1.5 parts of a methacrylate resin (Mitsubishi Rayon Co., Ltd., molecular weight 95,000) are placed in a pressure kneader together with 500 parts of toluene, and then at room temperature for 15 minutes. After stirring and mixing, the temperature was raised to 70 ° C. while mixing under reduced pressure to distill off toluene, followed by cooling and classification using a 105 μm sieve to prepare a resin-coated carrier.
The resin-coated carrier and the toner were mixed to prepare a two-component electrostatic charge image developer having a toner concentration of 7% by weight.
[0096]
(Image evaluation)
Using this electrostatic charge image developer, an image was formed on a transparent film made of polyethylene terephthalate having a 0.2 μm thick resin layer of a styrene / methyl methacrylate copolymer having a weight average molecular weight of 50,000. As a result of the evaluation, the surface gloss was poor, the smoothness was somewhat rough, the color development was slightly thin, the color mixing was turbid, the transparency was slightly turbid, and the gloss Gs was 46%. Met. Also, the hot offset property was good.
[0097]
[Comparative Example 2]
(Preparation of aggregated particle dispersion)
Resin particle dispersion (3) 300 parts
Colorant dispersion (2) 15 parts
Release agent dispersion ・ ・ ・ ・ ・ ・ ・ ・ ・ 25 parts
Zinc chloride ... 1 part
Ion-exchanged water ... 500 parts
The components were placed in a round stainless steel flask, dispersed using a homogenizer (IKA, Ultra Turrax T50), and then heated to 55 ° C. with stirring in an oil bath for heating. After maintaining at 55 ° C. for 30 minutes, observation with an optical microscope confirmed that aggregated particles having an average particle diameter of about 5.2 μm were formed.
[0098]
(Preparation of adherent particle dispersion)
To this agglomerated particle dispersion, 150 parts of the resin particle dispersion (3) was gently added, and the temperature of the heating oil bath was raised and maintained at 56 ° C. for 2 hours. When observed with an optical microscope, it was confirmed that adhered particles having an average particle diameter of about 5.7 μm were formed.
[0099]
(Fusion of adhered particles)
It was 3.0 when pH at 56 degrees C of the said adhesion particle dispersion was measured. 1N NaOH aqueous solution was added to this dispersion to adjust the pH at 56 ° C. to 8.0, and the adhering particles were stabilized. Then, the mixture was heated to 93 ° C. while stirring, and then maintained for 5 hours. Adherent particles were fused. The reaction product was filtered, sufficiently washed with ion exchange water, and then dried with a vacuum dryer to obtain toner particles.
[0100]
(Evaluation of toner particles)
The obtained toner particles had an average particle size of 5.1 μm and a GSDv of 1.20. To 100 parts of the toner particles, 1 part of colloidal silica (manufactured by Nippon Aerosil Co., Ltd., R972) was externally added and mixed using a Henschel mixer to obtain an electrostatic image developing toner.
The crosslinking density of the obtained toner was measured by a dynamic viscoelasticity temperature dispersion measurement method, and found to be 8.2 × 10.^-9/ Kmol. When the cross section of the toner particles was observed with a transmission electron microscope (TEM), the average particle diameter of the pigment particles was 310 nm.
[0101]
(Preparation of electrostatic charge image developer)
100 parts of ferrite particles (manufactured by Powdertech Co., Ltd., average particle size 50 μm) and 1.5 parts of a methacrylate resin (Mitsubishi Rayon Co., Ltd., molecular weight 95,000) are placed in a pressure kneader together with 500 parts of toluene, and then at room temperature for 15 minutes. After stirring and mixing, the temperature was raised to 70 ° C. while mixing under reduced pressure to distill off toluene, followed by cooling and classification using a 105 μm sieve to prepare a resin-coated carrier.
The resin-coated carrier and the toner were mixed to prepare a two-component electrostatic charge image developer having a toner concentration of 7% by weight.
[0102]
(Image evaluation)
Using this electrostatic charge image developer, an image was formed on a transparent film made of polyethylene terephthalate having a 0.2 μm thick resin layer of a styrene / methyl methacrylate copolymer having a weight average molecular weight of 50,000. As a result of the evaluation, the surface gloss, smoothness, color developability, color mixing, and transparency were good, and the glossiness Gs was 93%. However, hot offset occurred at 180 ° C.
[0103]
[Table 1]

[0104]
【The invention's effect】
By adopting the above-described configuration, the present invention enables formation of a fixed image having excellent smoothness, transparency, color mixing, and color development, as well as non-fixing sheet peelability and HOT resistance (hot). It has excellent offset properties and enables highly reliable image formation. In particular, it has become possible to easily and easily form a high-quality and reliable image in the formation of a full-color image.

Claims (2)

In the image forming method comprising the steps of forming a latent image on an electrostatic latent image holding member, developing the latent image with a developer, and fixing the developed image on the transparent transfer member, the transparent transfer member comprises: A dynamic viscoelasticity using a toner having a resin layer on the surface, wherein the developer includes a binder resin and a colorant that are crosslinked by at least one of the crosslinking agents represented by the following general formula: The cross-linking density Me of the toner determined by the temperature dispersion measurement method in the above is 1.6 × 10 ^{−8 to} 3.5 × 10 ⁻⁶ / Kmol, and the gloss of the fixing surface when melt-fixed on the transparent transfer member An image forming method, wherein the degree Gs is 80% or more.
_{H 2 C = CR-CO-} O-Xn-CO-CR = CH 2
(Wherein, n 3-15 integer, X is CH ₂ or _CH 2 _CH 2 O, R represents H or CH _{3.)
H 2 C = CR-CO-} O-Xn-CH 2 CH 2 O-CO-CR = CH 2
(Wherein, n an integer of 4 to 14, X is _CH 2, R represents H or CH _3.)   2. The image forming method according to claim 1, wherein the fixing is oilless fixing.