JP5308957B2 - Toner for electrostatic charge development - Google Patents

Description

INDUSTRIAL APPLICABILITY The present invention is used in a toner in which resin particles containing a second release agent are added to colored particles containing a first release agent, particularly in an electrophotographic technique used in an image forming apparatus such as a copying machine and a printer. Relating to the toner used.
More specifically, the present invention relates to a toner used in electrophotographic technology, wherein the melting point of the first release agent is lower than the melting point of the second release agent.

  Electrophotographic recording involves uniformly charging an optical semiconductor layer and then exposing the layer to dissipate the charge on the exposed portion as described in US Pat. No. 2,229,769, etc. Then, an electrostatic latent image is formed, and a colored fine powder having a charge called toner is attached to the electrostatic latent image to form a visible image (development process), and the obtained visible image is applied to a transfer material such as paper. After the transfer (transfer process), the process comprises a process of fixing by heating, pressure or other suitable fixing method (fixing process). A cleaning process is also provided for removing the toner remaining on the optical semiconductor after the toner is transferred.

As described above, the toner must have functions required not only in the development process but also in each process such as a transfer process, a fixing process, and a cleaning process.
Typical toner fixing methods include a heat fixing method in which toner is heated and melted and fixed on paper, and a pressure fixing method in which the toner is plastically deformed and fixed on paper by pressure. From the standpoint of image quality and the like later, a heat roll fixing method using a heat roll as a heating medium is most often used.

  In the heat fixing method, the toner must be melted at a temperature as low as possible and fixed to a medium such as paper. In recent years, the demand for low-temperature fixability of toner is particularly high from the viewpoint of energy saving. In order to meet this demand, attempts have been made to lower the resin molecular weight or lower the softening temperature of the toner by adding wax.

However, although these methods are effective for low-temperature fixability, the fixing area is narrowed, so that toner stains on the fixing roller and belt accumulate when running for a long time, resulting in a deterioration in image quality. Had occurred.
In addition, the lowering of the melting point of the toner has a limitation in coexistence of the low temperature fixing property, securing the fixing area and improving the toner durability since the storage stability and durability during long-term running are lowered.

  In recent years, in order to solve these problems, a vinyl polymer coating obtained by emulsifying and polymerizing a vinyl monomer containing a release agent in an aqueous system and / or release agent fine particles which are impregnated release agent fine particles are colored resin. A toner fixed on the surface of fine particles has been proposed (see Patent Document 1). Further, an electrophotographic toner has been proposed in which a release agent is composed of two or more compounds, at least one of which is a microencapsulated release agent and a colored resin (see Patent Document 2).

  Further, the electrostatic charge is obtained by coating the surface of a toner having an average particle diameter of 2 to 20 μm with resin fine particles encapsulating 2 to 50 parts of wax having an average particle diameter of 0.1 to 1 μm and fixing or fusing. An image developing toner has been proposed (see Patent Document 3).

JP-A-8-160660 JP 2006-308877 A JP 2001-235895 A

However, the toners of Patent Documents 1 and 2 have good storage stability because the resin fine particles encapsulating the release agent are dispersed in the toner. However, since the exudation of wax is suppressed, the toner is peeled off at the time of fixing. The problem is that the property is poor and the fixing area is narrow.
In addition, the toner of Patent Document 3 has good releasability because the resin fine particles encapsulating the release agent cover the toner. However, both the toner and the resin fine particle wax are low-temperature wax having a melting point of 60 to 70 ° C. Since it was used, there were problems in terms of storage stability and durability.

  The present invention has been made in view of such circumstances, and the present invention includes a release agent having a different melting point, in which resin fine particles encapsulating a release agent are added to colored particles containing the release agent. The main purpose is to provide a toner with few image defects over a long period of time because it has excellent low-temperature fixing and storage stability, good releasability from the fixing roller, and high transferability by using different colorants and resin fine particles. And

  As a result of intensive research efforts, the present inventor removed resin fine particles encapsulating a release agent having a melting point in a specific temperature range higher than the melting point of the release agent in a colored particle containing at least a release agent having a low melting point. The present inventors have found that the above problems can be solved by toner added as an additive, and have completed the present invention.

  However, according to the present invention, in the toner in which the external additive is added to the colored particles, the colored particles are formed from at least the colorant, the binder, and the first release agent, and the external additive is the second release agent. There is provided a toner comprising resin fine particles encapsulating an agent, wherein the melting point of the first release agent is lower than the melting point of the second release agent.

In addition, according to the present invention, a toner is provided in which the melting point of the first release agent is 0 ° C. to 55 ° C. lower than the melting point of the second release agent.
Further, according to the present invention, there is provided the toner according to claim 1, wherein the melting point of the first release agent is 65 to 85 ° C., and the melting point of the second release agent is 85 to 120 ° C. .

Further, according to the present invention, there is provided a toner in which the softening point of the resin in the colored particles is 110 to 130 ° C., and the softening point of the resin in the resin particles is 120 to 150 ° C.
Further, according to the present invention, there is provided a toner in which the resin fine particles have a volume average particle diameter of 100 to 300 nm.

In addition, according to the present invention, there is provided a toner in which the resin fine particles enclose a hydrocarbon wax as a release agent.
In addition, according to the present invention, there is provided a toner in which the resin fine particles contain Fischer-Tropsch wax or polyethylene wax as a release agent.
Further, according to the present invention, the toner in which the resin fine particles are obtained by a seed polymerization method using Fischer-Tropsch wax or polyethylene wax as a release agent and at least styrene and n-butyl acrylate.

Further, according to the present invention, there is provided a toner in which the colored particles contain a polar wax as a release agent.
Further, according to the present invention, there is provided a toner in which the colored particles contain an ester wax or carnauba wax as a release agent.
Furthermore, according to the present invention, there is provided a toner in which the external additive is added at a ratio of 0.5 to 5 parts by weight with respect to 100 parts by weight of the colored particles.

In the toner according to the present invention, the melting point of the first release agent included in the colored particles is lower than the melting point of the second release agent included in the resin fine particles externally added to the colored particles. A toner that has excellent storage stability and durability, is excellent in low-temperature fixing, has good releasability from a fixing roller, and has high transferability.
In the toner according to the present invention, when the colored particles contain a release agent having a melting point of 65 to 85 ° C., the toner has excellent storability and can be fixed at a low temperature.

  Furthermore, the resin fine particles added to the colored particles contain a release agent having a melting point of 85 to 120 ° C., so that the release of the release agent to the toner can be prevented, and the toner has excellent durability and can be fixed at a low temperature. Toner with good properties can be provided.

Further, since the softening point of the resin in the colored particles is 110 to 130 ° C., good storage stability and a low fixing temperature are possible, and the softening point of the resin in the resin particles is 120 to 150 ° C. As a result, it is possible to provide a toner having good storage and releasability.
Further, since the resin fine particles have a volume average particle diameter of 100 nm to 300 nm, the release agent is completely contained, storage stability and durability are not deteriorated, and adhesion is strong and does not detach from the toner even after long-term running, Provided is a toner that is less likely to cause image defects because transferability is unlikely to deteriorate.

  In addition, since hydrophobic hydrocarbon wax is used, when a release agent-containing fine particle is produced by a wet method, if a highly hydrophilic resin component is used, a resin layer is formed on the surface layer of the resin fine particle, and the resin layer is peeled off inside the resin fine particle. Toner with high release agent content, exfoliation of release agent, long-term storage stability and durability, low release from toner even after long-term running, and low transferability Is provided.

  In addition, the hydrocarbon wax used by the resin fine particles as a release agent, that is, Fischer-Tropsch wax or polyethylene wax has few low molecular components, so that the melting point is sharp, the storage stability does not deteriorate, and the long-term running A toner that is less prone to image defects is provided.

  In addition, since the colored particles have polar wax as a release agent, that is, ester wax or carnauba wax, the polarity of the wax is close to the polarity of the binder resin, the dispersion diameter of the wax is reduced and the release from the toner is reduced. In addition, even if these waxes have a low melting point, since the penetration is relatively small, it is possible to provide a preferable toner because both low-temperature fixing and storage stability can be achieved.

Hereinafter, the present invention will be described in detail.
According to the present invention, in a toner in which an external additive is added to colored particles, the colored particles are formed of at least a colorant, a binder, and a first release agent, and the external additive includes a second release agent. Resin fine particles, wherein the melting point of the first release agent is lower than the melting point of the second release agent.
If the release agent is contained only in the inside of the colored particles, the release agent is difficult to ooze out, and the peelability is not good. However, a toner having better releasability can be obtained by adding resin fine particles encapsulating a release agent to the surface of the colored particles.

  The “resin fine particles encapsulating the second release agent” used in the present invention is described in detail below. For example, a method of seed polymerizing a monomer mixture using wax fine particles as a seed, or a release agent in a resin solvent solution It means resin fine particles encapsulating wax as a release agent in resin fine particles obtained by a method of removing the solvent after phase inversion emulsification in water.

[Colored particles]
Binder resin The binder resin is not particularly limited as long as it is a thermoplastic resin.
Specifically, styrenes such as styrene, parachlorostyrene, and α-methylstyrene; acrylic simple substances such as methyl acrylate, ethyl acrylate, n-propyl acrylate, lauryl acrylate, and 2-ethylhexyl acrylate. A mer; Methacrylic monomer such as methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, lauryl methacrylate, and 2-ethylhexyl methacrylate; Ethylene such as acrylic acid, methacrylic acid, and sodium styrenesulfonate Unsaturated acid monomers; Vinyl nitriles such as acrylonitrile and methacrylonitrile; Vinyl ethers such as vinyl methyl ether and vinyl isobutyl ether; Vinyl kets such as vinyl methyl ketone, vinyl ethyl ketone, and vinyl isopropenyl ketone It can be mentioned resins obtained by polymerization of the kind or the like.

Furthermore, as the binder resin, homopolymers such as monomers such as ethylene, propylene, and olefins such as butadiene; copolymers obtained by combining two or more of these monomers; homopolymers and / or Mixtures of copolymers; Non-vinyl condensation resins such as epoxy resins, polyester resins, polyurethane resins, polyamide resins, cellulose resins, and polyether resins; mixtures of these resins and vinyl resins; vinyl resins in the presence of these resins Examples thereof include a resin such as a graft polymer obtained by polymerizing monomers.
Of the various resins described above, polyester resins and epoxy resins are excellent in terms of low-temperature fixability and durability.

Colorant As the colorant used in the toner of the present invention, various kinds and colors of various colors can be used regardless of whether they are organic or inorganic.
That is, examples of the black colorant include colorants such as carbon black, copper oxide, manganese dioxide, aniline black, activated carbon, nonmagnetic ferrite, magnetic ferrite, and magnetite.

Yellow pigments include yellow lead, zinc yellow, cadmium yellow, yellow iron oxide, mineral fast yellow, nickel titanium yellow, navel yellow, naphthol yellow S, Hansa Yellow G, Hansa Yellow 10G, Benzidine Yellow G, Benzidine Yellow GR, and quinoline. Coloring agents such as yellow lake, permanent yellow NCG, and tartrazine lake can be mentioned.
Examples of the orange pigment include colorants such as red chrome yellow, molybdenum orange, permanent orange GTR, pyrazolone orange, Vulcan orange, indanthrene brilliant orange RK, benzidine orange G, and indanthrene brilliant orange GK.

  Examples of red pigments include bengara, cadmium red, red lead, mercury sulfide, cadmium, permanent red 4R, risol red, pyrazolone red, watching red, calcium salt, lake red C, lake red D, brilliant carmine 6B, eosin lake, Coloring agents such as rhodamine lake B, alizarin lake, and brilliant carmine 3B can be mentioned.

Examples of purple pigments include colorants such as manganese purple, fast violet B, and methyl violet lake.
Examples of blue pigments include colorants such as bitumen, cobalt blue, alkali blue lake, Victoria blue lake, copper phthalocyanine blue, metal-free phthalocyanine blue, phthalocyanine blue partially chlorinated, first sky blue, and induslen blue BC. it can.
Examples of the green pigment include colorants such as chromium green, chromium oxide, pigment green B, micalite green lake, and final yellow green G.

The colorant concentration in the toner of the present invention is preferably in the range of 5 to 12% by weight and more preferably in the range of 6 to 8% by weight with respect to the total toner in the case of a black colorant such as carbon black. It is more preferable.
The colorant concentration in the case of a color image is preferably in the range of 3 to 8% by weight, more preferably in the range of 4 to 6% by weight.

First Release Agent The first release agent contained in the colored particles in the toner according to the present invention has a melting point of 0 ° C. to 55 ° C. than the second release agent contained in the resin fine particles externally added to the colored particles. It is characterized by being low.
More specifically, the melting point of the first release agent in the colored particles is 65 to 85 ° C, more preferably 70 to 80 ° C.

  If the melting point of the release agent is 85 ° C. or higher, the fixing temperature must be set high. If the melting point of the release agent is 65 ° C. or lower, the release agent in the colored particles tends to exude and the storage stability of the toner is reduced. End up.

  Examples of the release agent include various release agents, in particular, low molecular weight polypropylene, polyethylene, oxidized polypropylene, and polyolefin waxes such as polyethylene. By using these release agents, the fixability of the toner of the present invention is improved. Improvement can be achieved.

In the present invention, the release agent in the colored particles is a polar wax.
Moreover, the release agent contained in the colored particles in the present invention is characterized in that the polar wax is an ester wax and a carnauba wax.
The addition amount of the release agent is preferably 1 to 10 parts by weight with respect to 100 parts by weight of the binder resin.

In the toner of the present invention, in addition to the binder resin, the colorant, and the first release agent, agents such as magnetic powder and a charge control agent may be blended as necessary.
Magnetic powder Examples of magnetic powder include magnetic materials such as magnetite, γ-hematite, and various ferrites.

Charge Control Agent There are two types of charge control agents for negatively charged toner and positively charged toner.
As the charge control agent for negatively charged toner, chromium / azo complex dye, iron azo complex dye and cobalt / azo complex dye; salicylic acid, salicylate compound or salicylic acid derivative chromium complex, zinc complex, aluminum complex or boron complex; naphthol Chromium, zinc, aluminum and boron complexes of acids, naphtholate compounds or naphtholic acid derivatives; chromium, zinc, aluminum or boron complexes of benzylic acid, benzylate compounds or benzylic acid derivatives; long chain alkyl carboxylates; Examples include surfactants such as long-chain alkyl sulfonates.

Examples of charge control agents for positively charged toners include derivatives such as nigrosine dyes, nigrosine dye derivatives, triphenylmethane derivatives, quaternary ammonium salts, quaternary phosphonium salts, quaternary pyridinium salts, guanidine salts and amidine salts. it can.
The charge control agent is preferably added in an amount of 0.01 to 5 parts by weight with respect to 100 parts by weight of the binder resin.

  For example, additives added for the purpose of adjusting fluidity, preventing toner filming on the photoreceptor, and improving the cleaning properties of residual toner on the photoreceptor drum include silica, alumina, titania, zirconia, oxidation Inorganic oxides such as tin and zinc oxide, and homo- and copolymer resin fine particles of compounds such as acrylic acid esters, methacrylic acid esters, and styrene, fluororesin fine particles, silicone resin fine particles, stearic acid, etc. Examples include higher fatty acids and metal salts of the higher fatty acids, and agents such as carbon black, graphite fluoride, silicon carbide, and boron nitride.

The addition amount of these various additives is preferably 0.2 to 10 parts by weight with respect to 100 parts by weight of the binder resin.
The softening point of the resin in the colored particles is preferably 110 to 130 ° C, more preferably 115 to 125 ° C.
When the softening point of the resin in the colored particles is 110 ° C. or lower, the storage stability is lowered, and when the temperature is 130 ° C. or higher, the fixing temperature is increased, which causes a problem in terms of energy saving.
The glass transition point of the binder resin is preferably 55 ° C. or higher, more preferably 60 ° C. or higher. Below this, the preservability decreases.

[Resin fine particles]
In the toner according to the present invention, an external additive containing a second release agent is added to the colored particles.

Second release agent The melting point of the second release agent contained in the resin fine particles externally added to the colored particles is preferably 85 to 120 ° C, more preferably 90 to 100 ° C.
When the melting point of the release agent in the resin fine particles is 85 ° C. or less, even if the release agent is contained, since the particle size of the resin fine particles is small, the release agent easily exudes from the resin fine particles, and the storage stability of the toner is reduced. Resulting in.
In addition, when the melting point of the release agent in the resin fine particles is 120 ° C. or higher, the release agent is difficult to melt and the release agent does not easily exude from the resin fine particles. Become.

Examples of the second release agent used for the resin fine particles used in the present invention include, for example, paraffinic, Fischer and olefinic hydrocarbon waxes and natural and synthetic fatty acid ester / fatty acid amides. Polar wax etc. are mentioned.
Among these, since hydrocarbon wax is hydrophobic, when producing release agent-encapsulated fine particles by a wet method, the resin component is composed of a surface layer because of its high hydrophilicity, and the inclusion property of the release agent is increased. Is preferred.

  Among the hydrocarbon waxes, Fischer-Tropsch wax and polyethylene wax are particularly preferable because they have a small number of low molecular components, have a sharp melting point, and do not deteriorate storage stability.

Resin fine particles The method for producing the resin fine particles encapsulating the second release agent is not particularly limited. Preferably, the monomer mixture is seed-polymerized using wax fine particles as a seed, or the release agent is dissolved in a resin solvent solution. A method of removing the solvent after phase inversion emulsification in water is used.
Among these, the seed polymerization method is particularly preferable from the viewpoint of inclusion of the release agent.

  Examples of the initiator used in the seed polymerization method include 2,2′-azobis (2-amidinopropane) dihydrochloride, 4,4′-azobis (4-cyanovaleric acid), 2,2′-azobis [ 2- (5-Methyl-2-imidazolin-2-yl) propane] dihydrochloride, 2,2′-azobis [2-methyl-N- (1,1-bis (hydroxymethyl) -2-hydroxyethyl) Propionamide], 2,2′-azobis [2-methyl-N- (2-hydroxyethyl) propionamide] and the like.

  Examples of the monomer used in the seed polymerization method include acrylics such as methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, and 2-ethylhexyl (meth) acrylate. Mention may be made of ethylenically unsaturated monomers such as alkyl esters of acid or methacrylic acid. These may be used alone or in combination of two or more.

  The ethylenically unsaturated monomer may be polymerized with other copolymerizable monomers. The other copolymerizable monomers are not particularly limited. For example, styrene, α-methylstyrene, vinyl toluene, t-butyl styrene, ethylene, propylene, vinyl acetate, vinyl propionate, acrylonitrile, methacrylonitrile. Etc. These may be used alone or in combination of two or more monomers.

The volume average particle diameter of the resin fine particles is preferably 100 nm to 300 nm.
When the volume average particle size is 100 nm or less, the release agent is not completely contained, so that the storage stability and durability are deteriorated.
Further, when the volume average particle diameter is 300 nm or more, the adhesive force of the resin fine particles is weak, so that the resin particles are detached from the toner by long-term running.

The amount of wax contained in the resin fine particles is 10 to 60 parts by weight, preferably 20 to 40 parts by weight, based on 100 parts by weight of the base resin.
If the amount of wax per 100 parts by weight of the base resin is less than 10 parts by weight, the oilless fixability cannot be sufficiently exhibited, and if it exceeds 60 parts by weight, the effect of imparting oilless fixability is sufficiently exhibited, but storage stability This is not preferable because the properties are deteriorated, the amount of wax used is increased, the cost reduction effect is reduced, and it is difficult to produce the wax-encapsulating resin fine particles.

The softening point of the resin in the resin fine particles is preferably 120 to 150 ° C, more preferably 125 to 145 ° C.
When the softening point of the resin is 120 ° C. or lower, the storage stability of the toner is lowered, and when the temperature is 150 ° C. or higher, the peelability is lowered.
The glass transition point of the binder resin is preferably 60 ° C. or higher, more preferably 65 ° C. or higher. When the glass transition point of the binder resin is 60 ° C. or less, the storage stability is lowered.

The amount of the resin fine particles added as an external additive to 100 parts by weight of the colored particles is in the range of 0.5 to 5 parts by weight, preferably 1 to 3 parts by weight.
When the addition amount of the resin fine particles is less than 0.5 parts by weight with respect to 100 parts by weight of the colored particles, the effect of the second release agent included in the externally added resin fine particles cannot be exhibited.
Further, when the amount of the resin fine particles added to 100 parts by weight of the colored particles is more than 5 parts by weight, the resin fine particles are detached from the toner with the lapse of time, which is not preferable.

  The amount of resin fine particles added is preferably in the range of 2 to 20 parts by weight per 100 parts by weight of toner. More preferably, it is 5 to 10 parts by weight. When the addition amount is 2 parts by weight or less, the effect of expanding the fixing offset area is reduced. On the other hand, if it is 20 parts by weight or more, the viscosity becomes too high and the fixing temperature becomes high.

The toner of the present invention produced by the above-described method is used to form an image on a sheet such as a copy sheet in an image forming apparatus such as a copying apparatus and a printer apparatus.
In the image forming apparatus using the toner of the present invention, when an image is formed on a sheet, the photosensitive drum is uniformly charged, and an optical image based on the image to be formed on the charged photosensitive drum is scanned. An electrostatic latent image is formed, and the formed electrostatic latent image is developed to make a visible image by attaching the toner of the present invention, the obtained visible image is transferred onto a sheet, and the transferred toner Is fixed on a sheet to form an image.

Next, the preparation conditions and evaluation of the toner of the present invention prepared under various conditions and the toner for the comparative sample will be described as examples.
First, a method for producing organic fine particles required for toner will be described.

Production Example 1
Production of resin fine particles MC-1 Polyethylene wax (manufactured by Baker Petrolite Co., Ltd .; melting point 87 ° C., POLYWAX-) with a mixture monomer of 70 parts by weight of styrene, 22 parts by weight of n-butyl acrylate and 2 parts by weight of methacrylic acid. 600 (trade name)) In a solution in which 30 parts by weight were added and heated to uniformly disperse / dissolve, and 3.5 parts by weight of sodium dodecylbenzenesulfonate as an emulsifier was dissolved in 400 ml of ion-exchanged water. The mixture was emulsified with a high-speed shearing emulsifier. 500 g of this emulsified liquid was put into a separable flask having a stirrer, a thermometer, and a nitrogen introducing tube, and after nitrogen substitution, the mixture was heated to 75 ° C.

  Next, 10 ml of an aqueous solution in which 1.35 parts by weight of sodium sulfite (manufactured by Wako Pure Chemical Industries, Ltd.) was dissolved was added to the container and reacted for 2 hours. Thereafter, 5 parts by weight of methyl methacrylate was added, the temperature was raised to 80 ° C., and stirring was further continued for 3 hours. Then, the reaction was terminated to prepare resin fine particles MC-1 having a volume average particle diameter of 145 nm. The emulsion was washed and freeze-dried to produce 100 g of resin fine particle powder. The resin fine particles had a weight average molecular weight of 74,000, Tg of 67 ° C., and a softening point of 132 ° C.

Production Example 2
Production of resin fine particles MC-2 In the production method of resin fine particles MC-1, by changing the release agent to Fischer-Tropsch wax (manufactured by Nippon Seisakusha; melting point 90 ° C., FNP-0090 (trade name)), Resin fine particles MC-2 having a volume average particle diameter of 185 nm, a weight average molecular weight of 72,000, Tg of 66 ° C., and a softening point of 134 ° C. were produced.

Production Example 3
Production of Resin Fine Particle MC-3 In the production method of resin fine particle MC-1, the volume average particle is obtained by changing the release agent to polyethylene wax (manufactured by Baker Petrolite; melting point 118 ° C., POLYWAX-2000 (trade name)). Resin fine particles MC-3 having a diameter of 145 nm, a weight average molecular weight of 77,000, Tg of 68 ° C., and a softening point of 137 ° C. were produced.

Production Example 4
Production of Resin Fine Particle MC-4 In the production method of resin fine particle MC-1, the volume average particle is obtained by changing the release agent to polyethylene wax (manufactured by Baker Petrolite; melting point 77 ° C., POLYWAX-500 (trade name)). Resin fine particles MC-4 having a diameter of 165 nm, a weight average molecular weight of 71,000, Tg of 65 ° C., and a softening point of 115 ° C. were produced.

Production Example 5
Production of Resin Fine Particle MC-5 In the production method of Resin Fine Particle MC-1, the volume average particle is obtained by changing the release agent to paraffin wax (manufactured by Nippon Seisakusha; melting point 75 ° C., HNP-9 (trade name)). Resin fine particles MC-5 having a diameter of 170 nm, a weight average molecular weight of 69,000, Tg of 64 ° C., and a softening point of 114 ° C. were produced.

Production Example 6
Production of Resin Fine Particle MC-6 In the production method of resin fine particle MC-1, the volume average particle diameter is changed by changing the release agent to polyethylene wax (manufactured by Mitsui Chemicals; melting point 126 ° C., high wax 400P (trade name)). Produced resin fine particles MC-4 having a 155 nm, a weight average molecular weight of 70,000, Tg of 67 ° C., and a softening point of 145 ° C.

Production Example 7
Production of resin fine particles MC-7 In the production method of resin fine particles MC-2, by changing the amount of the emulsifier to 5.5 parts by weight, the volume average particle diameter is 85 nm, the weight average molecular weight is 74,000, Tg 67 ° C., Resin fine particles MC-7 having a softening point of 130 ° C. were prepared.

Production Example 8
Production of resin fine particles MC-8 In the production method of resin fine particles MC-2, by changing the amount of the emulsifier to 3.9 parts by weight, the volume average particle diameter is 120 nm, the weight average molecular weight is 72,000, Tg 67 ° C., Resin fine particles MC-8 having a softening point of 132 ° C. were prepared.

Production Example 9
Production of resin fine particles MC-9 In the production method of resin fine particles MC-2, by changing the amount of the emulsifier to 2.3 parts by weight, the volume average particle diameter is 290 nm, the weight average molecular weight is 73,000, Tg 66 ° C., Resin fine particles MC-9 having a softening point of 133 ° C. were produced.

Production Example 10
Production of resin fine particles MC-10 In the production method of resin fine particles MC-2, by changing the amount of the emulsifier to 1.6 parts by weight, the volume average particle diameter is 350 nm, the weight average molecular weight is 75,000, Tg 65 ° C., Resin fine particles MC-10 having a softening point of 133 ° C. were produced.

Production Example 11
Resin fine particles MC-11
In the production method of resin fine particles MC-1, by changing the release agent to ester wax (manufactured by NOF Corporation; melting point 88 ° C., WEP-8 (trade name)), the volume average particle diameter is 150 nm and the weight average molecular weight is Resin fine particles MC-11 having 72,000, Tg of 61 ° C. and a softening point of 125 ° C. were produced.

  The types of wax as a release agent used for the production of the resin fine particles MC-1 to MC-11 produced in the above Production Examples 1 to 11, the melting point thereof, and the volume average particle diameter of the obtained resin fine particles are as follows. It is shown in the table.

Example 1
MW = 10200, MW / MN = 6.8, glass transition temperature Tg = 61 ° C., 1/2 flow softening temperature Tm = 118 ° C., 79 parts by weight of polyester resin having an acid value of 18 KOHmg / g, 40 in advance in the polyester resin 15 parts by weight of a copper phthalocyanine pigment kneaded and preliminarily kneaded and dispersed at a concentration of 5% by weight (pigment concentration 6%), 2 parts by weight of an alkyl salicylic acid metal salt, an ester wax (manufactured by NOF Corporation; melting point 78 ° C.) Part by weight was put into a Henschel mixer and mixed for 10 minutes to obtain 2000 g of a raw material mixture. The obtained raw material was melt kneaded and dispersed with a set temperature of 110 ° C. and a supply amount of 5 kg / H in a Ikegai biaxial kneader PCM-37. The kneaded product thus obtained is subjected to cooling and coarse crushing steps, finely pulverized by a jet type pulverizer, and then subjected to air classification, a substantially normal distribution having a volume average particle diameter of 7.0 μm and a coefficient of variation of about 22. As a result, 1050 g of colored particles adjusted to ˜ were obtained.

Hydrophobic silica fine powder (BET specific surface area 140 m ² ) surface-treated with 2.5 parts by weight of MC-1 fine particles as resin fine particles, a silane coupling agent and dimethyl silicone oil was added to 100 parts by weight of the obtained colored particles. / G) 0.6 parts by weight and 0.4 parts by weight of titanium oxide (BET specific surface area 130 m ² / g) were mixed to obtain 100 g of negative triboelectrically chargeable toner of Example 1.

Example 2
Colored particles were obtained in the same manner as in Example 1 except that the release agent in Example 1 was changed to carnauba wax (manufactured by Toa Kasei Co., Ltd .; melting point 82 ° C.), and the negative friction of Example 2 was obtained using the particles. A chargeable toner was obtained.

Example 3
Colored particles were obtained in the same manner as in Example 1 except that the release agent of Example 1 was changed to ester wax (manufactured by NOF Corporation; melting point 68 ° C.), and negative friction of Example 3 was further obtained using the particles. A chargeable toner was obtained.

Example 4
Except for changing the release agent of Example 1 to paraffin wax (manufactured by Nippon Seiki Co., Ltd .; melting point 75 ° C.), colored particles were obtained in the same manner as in Example 1, and further colored particles were obtained using the particles. Further, a negative triboelectrically chargeable toner of Example 4 was obtained using the particles.

Example 5
A negative triboelectric charge toner of Example 5 was obtained in the same manner as in Example 1 except that the resin fine particles of Example 1 were changed to MC-2.

Example 6
A negative triboelectric charge toner of Example 6 was obtained in the same manner as in Example 1 except that the resin fine particles of Example 1 were changed to MC-3.

Example 7
A negative triboelectric charge toner of Example 7 was obtained in the same manner as in Example 1 except that the resin fine particles of Example 1 were changed to MC-7.

Example 8
A negative triboelectric toner of Example 8 was obtained in the same manner as in Example 1 except that the resin fine particles of Example 1 were changed to MC-8.

Example 9
A negative tribocharging toner of Example 9 was obtained in the same manner as in Example 1 except that the resin fine particles of Example 1 were changed to MC-9.

Example 10
A negative triboelectric toner of Example 10 was obtained in the same manner as in Example 1 except that the resin fine particles of Example 1 were changed to MC-10.

Example 11
A negative triboelectric toner of Example 11 was obtained in the same manner as in Example 1 except that the resin fine particles of Example 1 were changed to MC-11.

Comparative Example 1
The negative electrode of Comparative Example 1 was prepared in the same manner as in Example 1 except that the resin fine particles of Example 1 were changed to a hydrophobic silica fine powder (BET specific surface area of 25 m ² / g) surface-treated with a silane coupling agent. A triboelectrically chargeable toner was obtained.

Comparative Example 2
A negative triboelectric chargeable toner of Comparative Example 2 was obtained in the same manner as in Example 1 except that the resin fine particles of Example 1 were changed to MC-4.

Comparative Example 3
A negative triboelectric chargeable toner of Comparative Example 3 was obtained in the same manner as in Example 1 except that the resin fine particles of Example 1 were changed to MC-5.

Comparative Example 4
A negative frictionally chargeable toner of Comparative Example 4 was obtained in the same manner as in Example 1 except that the resin fine particles of Example 1 were changed to MC-6.

Comparative Example 5
Colored particles were obtained in the same manner as in Example 1 except that the release agent of Example 1 was changed to ester wax (manufactured by NOF Corporation; melting point 62 ° C.), and negative friction of Comparative Example 5 was further obtained using the particles. A chargeable toner was obtained.

Comparative Example 6
Colored particles were obtained in the same manner as in Example 1 except that the release agent in Example 1 was changed to polyethylene wax (manufactured by Baker Petrolite; melting point: 87 ° C.). A triboelectrically chargeable toner was obtained.

  The types of wax as a release agent used in the production of colored particles and toners in Examples 1 to 11 and Comparative Examples 1 to 6, their melting points, and resin fine particles are shown in the following table.

The produced toners of Examples 1 to 11 and Comparative Examples 1 to 6 were evaluated as follows.
Evaluation 1: Volume average particle size measurement of resin fine particles The volume average particle size of organic fine particles is measured using a laser light scattering particle size measuring device DLS-700 (manufactured by Otsuka Electronics Co., Ltd.).

Evaluation 2: Volume average particle diameter measurement of toner particles Using Coulter Multitizer II (manufactured by Coulter, Inc.), the volume average particle diameter of toner particles is measured using a 100 μm aperture.

Evaluation 3: Melting point of mold release agent Using a differential scanning calorimeter (trade name: DSC220, manufactured by Seiko Denshi Kogyo Co., Ltd.), 1 g of a sample was heated from a temperature of 20 ° C. to 200 ° C. at a heating rate of 10 ° C. per minute, Subsequently, the operation of rapidly cooling from 200 ° C. to 20 ° C. was repeated twice, and the DSC curve was measured. The temperature at the top of the endothermic peak corresponding to the melting of the DSC curve measured in the second operation was determined as the melting point of the release agent.

Evaluation 4: Softening point of resin fine particles Using a Koka flow tester (manufactured by Shimadzu Corporation, CFT-500), the temperature at which half of the sample flows out is defined as the softening point (sample: 1 g, heating rate: 6). (C / min, load: 20 kg / cm ² , nozzle: 1 mmφ × 1 mm)

Evaluation 5: Weight average molecular weight of the sample in terms of polystyrene was determined by molecular weight gel permeation chromatography (GPC) of resin fine particles. Equipment used and conditions are as follows. The molecular weight calibration curve was prepared using standard polystyrene.
Apparatus: SYSTEM-11 (trade name, manufactured by Showa Denko KK)
Column: 3 TSKgelαMXL (trade name, manufactured by Tosoh Corporation) Measurement temperature: 40 ° C.
Sample solution: 0.10% tetrahydrofuran solution of sample Injection amount: 100 mL
Detector: Refractive index detector

Evaluation 6: Glass transition point of resin fine particles Measurement was performed at a temperature rising rate of 10 ° C./min using a differential scanning calorimeter (DSC210, manufactured by Seiko Denshi Kogyo Co., Ltd.).

Evaluation 7: Low-temperature fixability evaluation Using an MX-450 machine manufactured by Sharp Corporation, an unfixed image was created on the entire A4 size test paper so that the toner adhesion amount was 1.0 mg / cm ² , and then oilless fixing was performed. Fixing was performed at a predetermined temperature with an external fixing device of the type, and the presence or absence of offset on the paper surface was visually evaluated. The process speed of the fixing machine was 220 mm / second, and 52 g / m ² paper was used for A4 size test paper.
In this evaluation method, the fixing temperature is low:
“G” (good) below 140 ° C;
145 to 155 ° C "NB" (not bad);
“B” (bad) for temperatures above 160 ° C;
In this case, “NB” or higher is set to a level that does not cause a problem in actual use.

Evaluation 8: Peeling evaluation by measuring offset property After leaving the unfixed image in an environment with a humidity of 90% for 24 hours, it is fixed at a predetermined temperature with an external fixing device of an oilless fixing method, and offset to the paper surface. The presence or absence of was visually evaluated. The process speed of the fixing machine was 220 mm / sec.
Under these conditions:
“G” (good) with a fixing area of 45 ° C. or higher;
"NB" (not bad) above 35 ° C;
"B" (bad) for those below 35 ° C;
In this case, “NB” or higher is set to a level that is not problematic in actual use.

Evaluation 9: Transfer efficiency Transfer efficiency is the ratio of toner transferred from the surface of the photosensitive drum to the intermediate transfer belt in the primary transfer, and was calculated with the amount of toner present on the photosensitive drum before transfer being 100%. The toner existing on the photosensitive drum before transfer was sucked using a charge amount measuring device (trade name: 210HS-2A, manufactured by Trek Japan Co., Ltd.), and the amount of the sucked toner was measured. . The amount of toner transferred to the intermediate transfer belt was also obtained in the same manner.
The evaluation criteria are as follows.
“G” (good): transfer efficiency is 90% or more “NB” (not bad): transfer efficiency is 85% or more and less than 90%.
“B” (bad): transfer efficiency is less than 85%.
In addition, “NB” or higher was set to a level at which there is no problem in actual use.

Evaluation 10: Storage stability evaluation by mesh up Toner 100 g was put in a polyethylene container and sealed, and then left in a thermostatic bath at 50 ° C. for 48 hours. The weight of the toner on the mesh was measured after the toner was vibrated at 60 Hz for 1 minute with a vibrating sieve equipped with a 200 mesh net.
The evaluation criteria are as follows, and the mesh-up rate is:
Less than 1.0% is “G” (good);
1.0 to 3.0 is “NB” (not bad);
3.0 or higher "B"(bad);
As a result, the “NB” or higher was set to a level that does not cause any problems in actual use.

  The following table shows the results of evaluating the low-temperature fixability, peelability, transfer porosity, storage stability and comprehensive judgment of the toners prepared in Examples 1 to 11 and Comparative Examples 1 to 6 in accordance with the evaluation methods described above. .

Comprehensive Judgment All three items of “G” were defined as “E” (excellent).
One or more items with “NB” were assigned “G” because there was no problem in actual use.
One with more than one item “B” was assigned “B” due to problems in actual use.

  From the above results, Examples 1 to 1 using resin fine particles MC-1 to MC-3 to MC-7 to 11 using polyethylene or Fischer Tropu having a melting point of 87 ° C. to 119 ° C. and a volume average particle size of 85 to 350 nm as the wax. In No. 11, the evaluation was “E” or “G”, and it was found that the toner was superior to the other comparative examples.

  In the toner according to the present invention, the colored particles contain a release agent having a melting point of 65 to 85 ° C., and the resin fine particles added to the colored particles contain the release agent having a melting point of 85 to 120 ° C. In addition, the presence of a release agent can provide a toner having good releasability and few image defects.

Claims (9)

In the toner in which an external additive is added to the colored particles, the colored particles are formed of at least a colorant, a binder, and a first release agent, and the external additive is a resin fine particle including a second release agent. The toner, wherein the melting point of the first release agent is 68 to 82 ° C., and the melting point of the second release agent is 87 to 120 ° C. Wherein a softening point of the resin is 110-130 ° C. in the colored particles, toner according softening point of the resin of the resin fine particles are to claim 1 which is 120 to 150 ° C.. The fine resin particles, toner according to claim 1 or 2 having a volume average particle diameter of 100 to 300 nm. The fine resin particles, toner according to any one of claims 1 to 3 which encloses a hydrocarbon wax as a release agent. The resin fine particles, Fischer as a release agent - toner according to any one of claims 1-4 for containing a Tropsch wax or polyethylene wax. The resin fine particles, Fischer as a release agent - and Tropsch wax or polyethylene wax, the toner according to any one of claims 1 to 5 which is obtained by seed polymerization method using at least styrene and n- butyl acrylate. The colored particles, toner according to any one of claims 1 to 6 comprising a polar wax as a release agent. The colored particles, toner according to any one of claims 1 to 7 comprising an ester wax or carnauba wax as a release agent. The external additive toner according to any one of claims 1-8, which is added in a proportion of 0.5 to 5 parts by weight with respect to the colored particles to 100 parts by weight.