JP2007271939A - Toner for developing electrostatic image - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a toner for developing electrostatic images which is balanced between storage stability and fixability at low temperatures and is excellent in offset resistance and printing durability. <P>SOLUTION: The toner for developing electrostatic images contains colored resin particles containing a binder resin, a coloring agent and a mold release agent, wherein the mold release agent is composed of: an aliphatic hydrocarbon polymer having a peak top molecular weight of ≥10,000 and a melting point of ≤70°C (1); and a low-molecular-weight wax having a peak top molecular weight of ≤5,000 (2). <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a toner for developing an electrostatic image that can be used for developing an apparatus using electrophotography such as a copying machine, a facsimile machine, and a printer.

  In an image forming apparatus using an electrophotographic method such as a copying machine, a facsimile machine, and a printer, an electrostatic latent image formed on a photoreceptor is firstly an electrostatic image developing toner (hereinafter also simply referred to as “toner”). )), And then the formed toner image is transferred onto a recording material such as paper or an OHP sheet, and then fixed by various methods such as heating, pressurization, and solvent vapor to form an image. Is done.

  In recent years, these image forming apparatuses are required to reduce energy consumption and increase printing speed. Of the electrophotographic image forming processes, a process that consumes a lot of energy is a process of fixing toner onto a recording material (fixing process). As a fixing method, a method of fixing by heating and pressing with a fixing roll is generally used. In this method, it is usually necessary to increase the temperature of the fixing roll at the time of fixing. Lowering the temperature of the fixing roll at the time of fixing is required from the viewpoint of energy saving. In addition, the fact that fixing at a low temperature is possible can cope with an increase in printing speed. From this viewpoint, it is required to lower the temperature of the fixing roll at the time of fixing.

  In order to obtain a toner having a low minimum fixing temperature, that is, a toner having excellent low-temperature fixability, a conventional method using a binder resin having a low glass transition temperature, a method of adding a resin having a low melting point or a low molecular weight, a release agent, etc. For example, a method of incorporating a low softening point substance having releasability such as wax into the toner has been proposed.

On the other hand, toners are required to have storability, offset resistance, and printing durability as characteristics contrary to low-temperature fixability.
Preservability is a characteristic that indicates the difficulty of toner aggregation (blocking) when the toner is stored at high temperature. This characteristic requires that the toner does not aggregate when the toner is transported or when the temperature in the printer rises due to heat generated by fixing during printing.
The anti-offset property is a characteristic indicating the width of the temperature range in which fixing is possible. In particular, a toner capable of low-temperature fixing needs to obtain stable print quality even when the temperature of the fixing roll rises and falls, and therefore, it is required that the toner does not fuse to the fixing roll even at a high fixing temperature. .
The printing durability is a characteristic that can maintain the printing quality even when a large number of sheets are printed. There is a demand for less deterioration of the toner due to stress received by the toner in the toner cartridge due to the printing of a large number of sheets.

  In order to solve the above required problems, Patent Document 1 discloses an ester wax (corresponding to “low molecular weight wax”) and a hydrocarbon wax (“aliphatic carbonization”) having a melting point in the temperature range of 55 to 120 ° C. The toner is characterized in that the melting point of the ester wax is lower (Claim 1), and the weight average molecular weight (Mw) of the ester wax is 350-1 500, the hydrocarbon wax has a weight average molecular weight (Mw) of 300 to 4,000 (claims 3 and 4).

  Patent Document 2 discloses polyester as a binder resin, ester wax (corresponding to “low molecular weight wax”) and petroleum wax (corresponding to part of paraffin wax “aliphatic hydrocarbon polymer”) as a release agent. The toner for developing an electrostatic charge image contained therein is disclosed (Claims 1 and 2). Further, it is described that the melting point of the petroleum wax is preferably 70 ° C. or more, and the molecular weight of the ester wax and the petroleum wax is described. Has not been.

  Furthermore, Patent Document 3 was obtained by polymerizing a monomer in the presence of a high melting point wax (polyethylene wax (corresponding to “aliphatic hydrocarbon polymer”)) having a melting point of 75 to 140 ° C. An electrophotographic toner comprising a wax-containing resin and a low-melting wax having a melting point of 50 to 90 ° C. (ester wax (corresponding to “low molecular weight wax”)) is disclosed (claims 1 to 3). In addition, the molecular weights of ester wax and polyethylene wax are not described.

  However, the toners of Patent Documents 1 to 3 satisfy the recent high demand level of maintaining the balance between the low-temperature fixability and the storage stability at a high level and also having the offset resistance and the printing durability. It was insufficient.

JP 2004-251932 A JP 2005-141189 A JP 2003-5431 A

  SUMMARY OF THE INVENTION An object of the present invention is to provide a toner for developing an electrostatic charge image that has a good balance between storage stability and low-temperature fixability, and is excellent in offset resistance and printing durability.

  As a result of intensive studies, the present inventors have solved the above-described problems with a toner for developing an electrostatic image using a high molecular weight, low melting point aliphatic hydrocarbon polymer and a low molecular weight wax as a release agent. I found what I can do.

  That is, according to the present invention, in the toner for developing an electrostatic image including colored resin particles containing a binder resin, a colorant, and a release agent, the release agent has (1) a peak top molecular weight of 10, An electrostatic charge image developing toner comprising an aliphatic hydrocarbon polymer having a melting point of 000 or more and a melting point of 70 ° C. or less, and (2) a low molecular weight wax having a peak top molecular weight of 5,000 or less. Is done.

  In the present invention, the low molecular weight wax is preferably an ester wax, and the aliphatic hydrocarbon polymer is an α-olefin polymer obtained by polymerizing an α-olefin monomer having 10 or more carbon atoms. More preferably.

In the present invention, the melting point of the aliphatic hydrocarbon polymer is preferably not more than the melting point of the low molecular weight wax, and the content ratio of the aliphatic hydrocarbon polymer to the low molecular weight wax ( The content of the aliphatic hydrocarbon polymer / the content of the low molecular weight wax) is preferably 98/2 to 25/75.
Furthermore, according to the present invention, the colored resin particles are preferably particles produced by a wet method.

  According to the present invention, there is provided a toner for developing an electrostatic charge image that balances the storage stability and low-temperature fixability of the toner, and is excellent in offset resistance and printing durability.

  The electrostatic charge image developing toner of the present invention will be described below.

  The electrostatic image developing toner of the present invention (in the present invention, “electrostatic image developing toner” is also simply referred to as “toner”) contains colored resin particles. The colored resin particles contain a binder resin, a colorant, and a release agent. The release agent includes (1) a peak top molecular weight of 10,000 or more and a melting point of 70 ° C. or less. An aliphatic hydrocarbon polymer and (2) a low molecular weight wax having a peak top molecular weight of 5,000 or less are used in combination. Furthermore, you may contain other additives, such as a charge control agent, as needed.

  Specific examples of the binder resin include resins conventionally used for toners such as vinyl resins such as polystyrene and styrene-butyl acrylate copolymers, polyester resins, epoxy resins, and cyclic isoprene rubber. it can. The number average molecular weight of the binder resin is not particularly limited, but is usually 2,000 to 50,000, preferably 3,000 to 30,000.

  In the present invention, a colorant is used. As the colorant, various pigments and dyes used in the toner field can be used. When producing a color toner, colorants of cyan, yellow and magenta can be used in addition to black and white.

Black colorants include carbon black, titanium black, and nigrosine-based dyes and pigments; magnetic powders such as cobalt, nickel, magnetite, iron tetroxide, manganese iron oxide, zinc iron oxide, and nickel iron oxide Or the like can be used. The carbon black preferably has a primary particle diameter of 20 to 40 nm. When the carbon black is in this range, the carbon black can be uniformly dispersed in the toner and fogging is reduced.
As a white colorant, titanium white or the like can be used.

  Examples of cyan colorants include copper phthalocyanine compounds, derivatives thereof, and anthraquinone compounds. I. And CI Pigment Blue 2, 3, 15, 15, 15: 1, 15: 2, 15: 3, 15: 4, 16, 17: 1, and 60.

  As the yellow colorant, monoazo pigments, azo pigments such as disazo pigments, and compounds such as condensed polycyclic pigments are used. I. Pigment Yellow 3, 12, 12, 13, 15, 17, 62, 65, 73, 74, 83, 93, 97, 120, 138, 155, 180, 181, 185, 186, 213, and the like.

  As the magenta colorant, compounds such as monoazo pigments, azo pigments such as disazo pigments, and condensed polycyclic pigments are used. Specifically, C.I. I. Pigment Red 31, 48, 57: 1, 58, 60, 63, 64, 68, 81, 83, 87, 88, 89, 90, 112, 114 122, 123, 144, 146, 146, 149, 150, 163, 170, 184, 185, 187, 202, 206, 207, 209, 213, 251 and C.I. I. Pigment violet 19 and the like.

  The amount of each colorant is usually 1 to 50 parts by weight, preferably 1 to 20 parts by weight, and particularly preferably 1 to 10 parts by weight with respect to 100 parts by weight of the binder resin.

  In the present invention, the peak top molecular weight is 10,000 or more and the melting point is 70 ° C. or less as a release agent in order to improve the storage stability and low-temperature fixability of toner, offset resistance and printing durability. A high molecular weight, low melting point aliphatic hydrocarbon polymer and a low molecular weight wax having a peak top molecular weight of 5,000 or less are used in combination.

  The aliphatic hydrocarbon polymer used in the present invention is a polymer obtained by polymerizing an aliphatic hydrocarbon monomer that is a hydrocarbon not containing an aromatic ring among hydrocarbons composed of only carbon atoms and hydrogen atoms. is there.

  Specific materials that can be used as the aliphatic hydrocarbon polymer include, for example, paraffin wax, microcrystalline wax, Fischer-Tropsch wax, α-olefin polymer, and other waxes.

  Among them, an α-olefin polymer obtained by polymerizing an α-olefin monomer having 10 or more carbon atoms is preferable, more preferably the carbon number is 16 or more, and further preferably 18 to 24. Especially preferably, it is 22 or more and 24 or less. If the carbon number exceeds this range, the resulting toner may be inferior in low-temperature fixability, and if it is less than this range, there may be a problem in storage stability. The α-olefin monomer is preferably purified by a method such as distillation.

  Specific examples of such preferable α-olefin monomers include 1-decene, 1-undecene, 1-dodecene, 1-tridecene, 1-tetradecene, 1-pentadecene, 1-hexadecene, 1-heptadecene, 1- Examples include octadecene, 1-nonadecene, 1-eicosene, 1-henecocene, 1-docosene, 1-tricosene, 1-tetracocene, 1-pentacocene, 1-hexacocene, and the like, preferably 1-eicosene, 1-docosene, 1 -Tetracocene, 1-hexacocene.

In the present invention, a metallocene compound is preferably used as a catalyst in the polymerization of the α-olefin monomer to obtain the α-olefin polymer.
Examples of the metallocene compound include dimethylsilylene bis (2-methyl-4,5-benzoindenyl) zirconium dichloride, dimethylsilylene bis (2-methyl-4-phenylindenyl) zirconium dichloride, dimethylsilylene bis (2-methyl- 4-naphthylindenyl) zirconium dichloride, dimethylsilylenebis (2-methylindenyl) zirconium dichloride, ethylenebis (2-methylindenyl) zirconium dichloride, (1,2'-dimethylsilylene) (2,1'-dimethyl) Silylene) bis (3-trimethylsilylmethyl-indenyl) zirconium dichloride, (1,2'-dimethylsilylene) (2,1'-dimethylsilylene) (3-trimethylsilylmethyl-indenyl) (indenyl) zirconium Mudichloride, (1,2'-dimethylsilylene) (2,1'-dimethylsilylene) bis (indenyl) zirconium dichloride, (1,2'-dimethylsilylene) (2,1'-dimethylsilylene) bis (3- n-butyl-indenyl) zirconium dichloride, (1,2′-dimethylsilylene) (2,1′-dimethylsilylene) (n-butyl-indenyl) (indenyl) zirconium dichloride, (1,2′-dimethylsilylene) ( 2,1′-dimethylsilylene) bis (indenyl) zirconium dichloride, 1,1′-dimethylsilylenebis (2-ethyl-4- (2-fluoro-4-biphenylyl) -4H-azurenyl) zirconium dichloride, and dimethylsilylene (Cyclopentadienyl) (2,4-dimethyl-4H-1-azule Z) Zirconium dichloride compounds such as zirconium dichloride, and zirconium compounds such as compounds in which the dichloride of these zirconium dichloride compounds is substituted with dimethyl or dibenzyl; and titanium compounds in which zirconium in these zirconium compounds is substituted with titanium; . Moreover, said metallocene compound may use 1 type, or may use 2 or more types together. In addition to the metallocene compound, an organoaluminum compound such as triisobutylaluminum and an organoboron compound such as dimethylanilinium tetrakispentafluorophenylborate are preferably used as the catalyst.

  In the present invention, in addition to the above-mentioned specific aliphatic hydrocarbon polymer, a low molecular weight wax having a peak top molecular weight of 5,000 or less is used in combination as a release agent. By using this low molecular weight wax, the effect of improving the offset resistance can be obtained.

  Low molecular weight waxes include, for example, animal and plant waxes such as candelilla, carnauba, rice, wood wax, and jojoba; petroleum waxes such as paraffin, microcrystalline, and petrolactam, and natural waxes such as modified waxes; and low molecular weights. Polyolefin wax such as polyethylene, low molecular weight polypropylene, and low molecular weight polybutylene; Fischer-Tropsch wax; fatty acid ester of linear saturated monohydric alcohol, fatty acid ester of glycerin, fatty acid ester of pentaerythritol, fatty acid ester of diglycerin, dipentaerythritol Ester waxes such as fatty acid esters of polyglycerin, fatty acid esters of polyglycerol, ester amide waxes, ketone waxes, substituted urea compounds, synthetic waxes, etc. It is. Among these, ester wax is preferable.

  Among ester waxes, compounds having a branch number of 3 or more are preferable from the viewpoint of solubility in monomers during toner synthesis. Specifically, glycerol tristearate, glycerol tribehenate, pentaerythritol tetrapalmitate, penta Examples include erythritol tetrastearate, diglycerin tetrapalmitate, diglycerin tetrastearate, dipentaerythritol hexamyristate, and dipentaerythritol hexapalmitate.

In the present invention, the peak top molecular weight of the release agent is measured by a gel permeation chromatograph (GPC) method. Specifically, it can be measured as follows.
As a measuring device, a GPC measuring device (manufactured by Waters, trade name: Alliance GPC2000) is used. As the sample solution to be injected, 240 μl of 1,2,4-trichlorobenzene (including 300 ppm of dibutylhydroxytoluene) solution having a concentration of 1 mg / ml for polymer and 0.5 mg / ml for wax is used, and the column is mixed. Using a polystyrene gel column (trade name: GMHHR-H (S) HT, manufactured by Tosoh Corporation), measurement is performed under the conditions of a column temperature of 145 ° C. and a flow rate of 1.0 ml / min. For detection, an infrared detector is used and a wavelength of 3.41 μm is used.

  The peak top molecular weight (Mp) of the aliphatic hydrocarbon polymer is more preferably 10,000 to 100,000, still more preferably 20,000 to 90,000. When the peak top molecular weight of the aliphatic hydrocarbon polymer is within the above range, the balance between the storage stability of the toner and the low-temperature fixability is good, and the printing durability is excellent.

  The peak top molecular weight (Mp) of the low molecular weight wax used in combination with the aliphatic hydrocarbon polymer is preferably 500 to 5,000, more preferably 1,000 to 4,500.

  The melting point of the release agent used in the present invention is a melting point defined as a temperature at the top of a peak in a DSC curve obtained by a differential scanning calorimeter (DSC). When there are a plurality of peaks, the temperature obtained by averaging the temperatures of the peaks is taken as the melting point. The DSC curve of the aliphatic hydrocarbon polymer used in the present invention preferably has only one peak, and this one peak may have a shoulder, but it is more preferable not to have a shoulder. preferable.

  In the present invention, the melting point of the aliphatic hydrocarbon polymer is 70 ° C. or lower, preferably 40 ° C. or higher and lower than 70 ° C., more preferably 45 ° C. or higher and lower than 65 ° C. When the melting point of the aliphatic hydrocarbon polymer is in the above range, the obtained toner is preferable because it has a good balance between storage stability and low-temperature fixability and is excellent in printing durability.

  The melting point of the low molecular weight wax is preferably 50 to 100 ° C., more preferably 60 to 90 ° C., preferably higher than the melting point of the aliphatic hydrocarbon polymer, and the melting point of the aliphatic hydrocarbon polymer. The temperature difference is preferably 50 ° C. or less, more preferably 30 ° C. or less, and further preferably 20 ° C. or less. When the melting point of the low molecular weight wax is in the above range, the obtained toner is preferable because both the storage stability and the low-temperature fixability are excellent.

  In this invention, the measurement of a mold release agent by a differential scanning calorimeter (DSC) is performed based on ASTM D3418-82, and a commercially available differential scanning calorimeter can be used. Examples of commercially available differential scanning calorimeters include a differential scanning calorimeter (trade name: RDC-220, manufactured by Seiko Instruments Inc.). In addition, this measurement is performed under conditions where the temperature is increased from −20 ° C. to 100 ° C. at 10 ° C./min.

  In the present invention, the content of the release agent is preferably 4 to 60 parts by weight, more preferably 6 to 50 parts by weight, and still more preferably 8 to 40 parts by weight with respect to 100 parts by weight of the binder resin. It is. In the release agent, the ratio of the content of the aliphatic hydrocarbon polymer to the low molecular weight wax (the content of the aliphatic hydrocarbon polymer / the content of the low molecular weight wax) is 98/2 to 25 / 75 is preferred, 96/4 to 50/50 is more preferred, and 94/6 to 55/45 is even more preferred. When the content of the release agent is within this range, the effect of the specific release agent in the present application can be sufficiently obtained.

  In the present invention, the colored resin particles preferably contain a charge control agent. When producing a negatively chargeable toner, a negatively chargeable charge control agent is mainly used, and when producing a positively chargeable toner, a positively chargeable charge control agent is mainly used. A small amount of a charge control agent having a polarity opposite to that of the main charge control agent may be used.

  Positively chargeable charge control agents include nigrosine dyes, quaternary ammonium salts, triaminotriphenylmethane compounds, imidazole compounds, polyamine resins, quaternary ammonium group-containing copolymers, and quaternary ammonium salt groups. There are charge control resins such as copolymers.

Examples of negatively chargeable charge control agents include azo dyes containing metals such as Cr, Co, Al, and Fe, salicylic acid metal compounds, alkyl salicylic acid metal compounds, sulfonic acid group-containing copolymers, and sulfonates. Examples thereof include charge control resins such as group-containing copolymers, carboxylic acid group-containing copolymers, and carboxylate group-containing copolymers.
In the present invention, the charge control agent is preferably a charge control resin because the printing durability of the toner is improved. When the charge control resin is used, the addition amount is usually 0.01 to 30 parts by weight, preferably 0.3 to 25 parts by weight with respect to 100 parts by weight of the binder resin.

  In the present invention, the method for producing the colored resin particles includes a dry method such as a pulverization method, and a wet method such as an emulsion polymerization aggregation method, a dispersion polymerization method, a suspension polymerization method, and a dissolution suspension method. The wet method is preferable because it is easy to obtain a toner excellent in printing characteristics such as the property. Among them, polymerization methods such as emulsion polymerization aggregation method, dispersion polymerization method, and suspension polymerization method are more preferable because a toner having a relatively small particle size distribution on the order of microns can be produced and an image with excellent image quality can be obtained. The suspension polymerization method is more preferable.

  As a wet method, the emulsion polymerization aggregation method polymerizes emulsified polymerizable monomers to obtain resin fine particles, and aggregates them with a colorant or the like to produce colored resin particles. In the dissolution suspension method, a solution in which a toner component such as a binder resin or a colorant is dissolved or dispersed in an organic solvent is formed into droplets in an aqueous medium, and the organic solvent is removed to produce colored resin particles. Each of which is a known method.

  When the colored resin particles are produced by employing the suspension polymerization method, which is a more preferred method for producing the toner of the present invention, the following process is performed. First, a polymerizable monomer, a colorant, a release agent, and, if necessary, other additives such as a charge control agent are mixed to obtain a polymerizable monomer composition. After this polymerizable monomer composition is placed in an aqueous medium containing a dispersion stabilizer, droplet formation is performed. Thereafter, polymerization is carried out in the presence of a polymerization initiator to obtain an aqueous dispersion of colored resin particles. This aqueous dispersion is washed, dehydrated and dried to obtain dried colored resin particles. The dried colored resin particles are classified as necessary, mixed with an external additive, and a carrier is further added as necessary to obtain a toner.

The polymerizable monomer is a main component that serves as a binder resin and refers to a polymerizable compound. In the aforementioned components such as the colorant, the weight of the binder resin used as the basis for the amount is substantially equal to the weight of the polymerizable monomer and can be replaced with the weight of the polymerizable monomer.
It is preferable to use a monovinyl monomer as the main component of the polymerizable monomer. The monovinyl monomer, styrene, acrylic acid, and methacrylic acid; vinyl toluene, and α- styrene derivative conductor methyl styrene and methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, 2 Acrylic esters such as ethylhexyl and dimethylaminoethyl acrylate; methacrylates such as methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, 2-ethylhexyl methacrylate, and dimethylaminoethyl methacrylate; acrylamide, Amide compounds such as methacrylamide; olefins such as ethylene, propylene, and butylene; vinyl halides and vinylidene halides such as vinyl chloride, vinylidene chloride, and vinyl fluoride; vinyl acetate, and Vinyl esters such as vinyl propionate; vinyl ethers such as vinyl methyl ether and vinyl ethyl ether; vinyl ketones such as vinyl methyl ketone and methyl isopropenyl ketone; 2-vinyl pyridine, 4-vinyl pyridine and N-vinyl pyrrolidone, etc. And a nitrogen-containing vinyl compound. These monovinyl monomers may be used alone or in combination. Of these, styrene, styrene derivatives, acrylic acid esters, and methacrylic acid esters are preferably used as monovinyl monomers.

  The monovinyl monomer is preferably selected so that the glass transition temperature (hereinafter referred to as Tg) of the polymer obtained by polymerizing the monovinyl monomer is 80 ° C. or lower. By using monovinyl monomers alone or in combination of two or more, the Tg of the polymer can be adjusted to a desired range.

  In order to improve hot offset, it is preferable to use any crosslinkable monomer together with the monovinyl monomer as part of the polymerizable monomer. A crosslinkable monomer refers to a monomer having two or more polymerizable functional groups. Examples of the crosslinking monomer include aromatic divinyl compounds such as divinylbenzene, divinylnaphthalene, and derivatives thereof; unsaturated polycarboxylic acid esters of polyhydric alcohols such as ethylene glycol dimethacrylate and diethylene glycol dimethacrylate; N, N -Other divinyl compounds such as divinylaniline and divinyl ether; compounds having three or more vinyl groups; These crosslinkable monomers can be used alone or in combination of two or more. The crosslinkable monomer is used in an amount of 0.1 to 5 parts by weight, preferably 0.3 to 2 parts by weight, based on 100 parts by weight of the monovinyl monomer.

  Furthermore, it is preferable to use a macromonomer as a part of the polymerizable monomer because the balance between the storage stability and low-temperature fixability of the obtained toner is improved. The macromonomer has a polymerizable carbon-carbon unsaturated double bond at the end of the molecular chain, and is a reactive oligomer or polymer having a number average molecular weight of 1,000 to 30,000. The macromonomer is preferably one that gives a polymer having a higher Tg than the Tg of the polymer obtained by polymerizing only the monovinyl monomer. The amount of the macromonomer is usually 0.01 to 10 parts by weight, preferably 0.03 to 5 parts by weight, and more preferably 0.05 to 1 part by weight with respect to 100 parts by weight of the monovinyl monomer.

  In the polymerization of the polymerizable monomer, it is preferable to use a molecular weight modifier as another additive. Examples of the molecular weight modifier include mercaptan compounds such as t-dodecyl mercaptan, n-dodecyl mercaptan, n-octyl mercaptan, and 2,2,4,6,6-pentamethylheptane-4-thiol.

  The polymerizable monomer composition obtained as described above is dispersed in an aqueous medium containing a dispersion stabilizer, and after adding a polymerization initiator, droplets of the polymerizable monomer composition are formed. Do. The method of forming the droplet is not particularly limited, but for example, an in-line type emulsifying disperser (manufactured by Ebara Seisakusho, trade name: Ebara Milder), a high speed emulsifying disperser (manufactured by Tokushu Kika Kogyo Co., Ltd., trade name: TK homomixer) (MARK II type) and the like capable of strong stirring.

The aqueous medium contains water as a main component, and a solvent that can be dissolved in water, such as lower alcohol and lower ketone, can also be used in combination.
The aqueous medium preferably contains a dispersion stabilizer. Examples of the dispersion stabilizer include sulfates such as barium sulfate and calcium sulfate; carbonates such as barium carbonate, calcium carbonate and magnesium carbonate; phosphates such as calcium phosphate; metal oxides such as aluminum oxide and titanium oxide; Metal hydroxides such as aluminum hydroxide, magnesium hydroxide, and ferric hydroxide; water-soluble polymers such as polyvinyl alcohol, methyl cellulose, and gelatin; anionic surfactants, cationic interfaces And organic compounds such as surfactants such as surfactants, nonionic surfactants, and amphoteric surfactants. The said dispersion stabilizer can be used 1 type or in combination of 2 or more types. Among them, the dispersion stabilizer containing a metal compound, particularly a colloid of a poorly water-soluble metal hydroxide, can narrow the particle size distribution of the colored resin particles, and the residual amount of the dispersion stabilizer after washing is small. The obtained toner is preferable because an image can be clearly reproduced and environmental stability is not deteriorated.

Examples of the polymerization initiator used for polymerization of the polymerizable monomer composition include potassium persulfate and persulfates such as ammonium persulfate; 4,4′-azobis (4-cyanovaleric acid), 2,2 ′. -Azobis (2-methyl-N- (2-hydroxyethyl) propionamide, 2,2'-azobis (2-amidinopropane) dihydrochloride, 2,2'-azobis (2,4-dimethylvaleronitrile), and Azo compounds such as 2,2′-azobisisobutyronitrile; di-t-butyl peroxide, benzoyl peroxide, t-butylperoxy-2-ethylhexanoate, t-hexylperoxy-2-ethyl Hexanoate, t-butyl peroxypivalate, diisopropyl peroxydicarbonate, di-t-butyl peroxyisophthalate, and t Examples thereof include organic peroxides such as butyl peroxyisobutyrate, etc. In addition, a redox initiator in which the above polymerization initiator and a reducing agent are combined may be used. It is preferable to use an organic peroxide because it can be reduced and durability is good.
As described above, the polymerization initiator may be added after the polymerizable monomer composition is dispersed in the aqueous medium and before droplet formation, but is added to the polymerizable monomer composition. May be.
The addition amount of the polymerization initiator is preferably 0.1 to 20 parts by weight, more preferably 1.0 to 10 parts by weight, with respect to 100 parts by weight of the monovinyl monomer.

As described above, droplets of the polymerizable monomer composition are formed, the aqueous medium containing the obtained polymerizable monomer composition droplets is heated, polymerization is started, and the colored resin particles An aqueous dispersion is obtained.
The polymerization temperature of the polymerizable monomer composition is preferably 50 ° C. or higher, more preferably 60 to 95 ° C. The polymerization reaction time is preferably 1 to 20 hours, more preferably 2 to 15 hours.

  The colored resin particles may be used in the toner as they are. However, the colored resin particles may be used as a core layer, and a colored resin particle having a so-called core-shell structure obtained by forming a shell layer different from the core layer on the outer side. preferable. Colored resin particles with a core-shell structure cover the core layer made of a material with a low softening point with a material having a higher softening point, thereby lowering the minimum fixing temperature (low temperature fixing property) and preventing aggregation during storage. Balance with (preservability).

  There is no restriction | limiting in particular as a method of manufacturing the colored resin particle of a core shell structure using the colored resin particle obtained by the polymerization method mentioned above, It can manufacture by a conventionally well-known method. An in situ polymerization method and a phase separation method are preferable from the viewpoint of production efficiency.

A method for producing colored resin particles having a core-shell structure by an in situ polymerization method will be described below.
Polymerization is performed by adding a polymerizable monomer (shell polymerizable monomer) and a polymerization initiator for forming a shell layer into an aqueous medium in which colored resin particles obtained by the polymerization method are dispersed. Thus, colored resin particles having a core-shell structure can be obtained.

  As the polymerizable monomer for the shell, those similar to the monovinyl monomer described above can be used. Among them, it is preferable to use monomers such as styrene, acrylonitrile, and methyl methacrylate, which can obtain a polymer having a Tg exceeding 80 ° C., alone or in combination of two or more.

  Polymerization initiators used for polymerization of the polymerizable monomer for shell include potassium persulfate and persulfate metal salts such as ammonium persulfate; 2,2′-azobis (2-methyl-N- (2-hydroxyethyl) Water-soluble polymerization initiators such as azo compounds such as propionamide) and 2,2′-azobis- (2-methyl-N- (1,1-bis (hydroxymethyl) 2-hydroxyethyl) propionamide); Can be mentioned. The amount of the polymerization initiator is preferably 0.1 to 30 parts by weight, more preferably 1 to 20 parts by weight with respect to 100 parts by weight of the polymerizable monomer for shell.

  The aqueous dispersion of colored resin particles obtained by the polymerization is subjected to filtration, washing to remove the dispersion stabilizer, dehydration, and drying after the completion of the polymerization. Is obtained.

  As the above washing method, when an inorganic compound such as an inorganic hydroxide is used as a dispersion stabilizer, the dispersion stabilizer is dissolved in water by adding an acid or alkali to the aqueous dispersion of colored resin particles. It is preferable to remove. When a colloid of a hardly water-soluble inorganic hydroxide is used as the dispersion stabilizer, it is preferable to adjust the pH of the colored resin particle aqueous dispersion to 6.5 or less by adding an acid. As the acid to be added, inorganic acids such as sulfuric acid, hydrochloric acid and nitric acid, and organic acids such as formic acid and acetic acid can be used.

  Various known methods can be used for the method of dehydration and filtration, and are not particularly limited. Examples thereof include a centrifugal filtration method, a vacuum filtration method, and a pressure filtration method. Also, the drying method is not particularly limited, and various methods can be used.

  When the colored resin particles are produced by employing a pulverization method which is a dry method, the following process is performed. Specifically, first, a binder resin, a colorant, a release agent, and optionally a charge control agent are further mixed using a mixer such as a ball mill, a V-type mixer, a Henschel mixer, a high-speed dissolver, an internal mixer, or the like. Mix. Next, the mixture obtained as described above is kneaded while being heated using a pressure kneader, a single screw extruder kneader, a twin screw extruder kneader, a roller or the like. The obtained kneaded material is coarsely pulverized using a pulverizer such as a hammer mill, a cutter mill, or a roller mill. Furthermore, after finely pulverizing using a pulverizer such as a jet mill and a high-speed rotary pulverizer, the resin is classified into a desired particle size by a classifier such as an air classifier and an airflow classifier, and a colored resin obtained by a pulverization method. Get particles. As the colorant used in the pulverization method and the charge control agent used as required, those mentioned in the above-described polymerization method can be used. It is the same weight part which read the weight part reference | standard as 100 weight part reference | standard of binder resin.

  The colored resin particles obtained by the above pulverization method can be made into core-shell structured colored resin particles by a method such as an in situ polymerization method in the same manner as the colored resin particles obtained by the polymerization method described above.

  The toner of the present invention may be used as the toner by using the colored resin particles as they are or by using the colored resin particles and carrier particles (ferrite, iron powder, etc.). In addition, using a high-speed stirrer (for example, Henschel mixer (trade name, manufactured by Mitsui Mining Co., Ltd.)), the colored resin particles and the external additive are mixed to form a one-component toner, or colored resin particles, In addition, it is preferable to mix the external additive and carrier particles to obtain a two-component toner.

  External additives include silica, titanium oxide, aluminum oxide, zinc oxide, tin oxide, calcium carbonate, calcium phosphate, cerium oxide and other inorganic fine particles; polymethyl methacrylate resin, silicone resin, melamine resin, etc. Fine particles are mentioned. Among these, inorganic fine particles are preferable, silica and titanium oxide are more preferable, and silica is more preferable. The addition amount of the external additive is 0.1 to 6 parts by weight, preferably 0.2 to 5.0 parts by weight with respect to 100 parts by weight of the colored resin particles.

  The volume average particle diameter (Dv) of the toner is preferably 3 to 15 μm, and more preferably 4 to 12 μm. If Dv is less than these ranges, the fluidity of the toner may decrease, transferability may deteriorate, blurring may occur, and image density may decrease, and if these ranges are exceeded, the resolution of the image decreases. There is a case.

  The ratio (Dv / Dp) of the volume average particle diameter (Dv) to the number average particle diameter (Dp), which represents the particle size distribution of the toner of the present invention, is preferably 1.00 to 1.30, and more preferably. Is 1.00-1.20. When Dv / Dp exceeds these ranges, blurring may occur, and transferability, image density, and resolution may decrease. Dv and Dp can be measured using, for example, a particle size measuring device (Beckman Coulter, trade name: Multisizer II).

  The present invention will be described in more detail with reference to examples, but the present invention is not limited to the following examples. Parts and% are based on weight unless otherwise specified.

The test methods performed in this example are as follows.
(Measurement of thermal properties of release agent by differential scanning calorimetry (DSC))
The thermal characteristics such as the melting point of the release agent were measured using a differential scanning calorimeter (trade name: RDC-220, manufactured by Seiko Instruments Inc.). 6-8 mg of the release agent was weighed in the sample holder and measured under the condition of increasing the temperature from −20 ° C. to 100 ° C. at 10 ° C./min to obtain a DSC curve. From this, the peak peak of the DSC curve was specified as the melting point (TmD).

(Peak top molecular weight of release agent)
The peak top molecular weight of the release agent was determined as a molecular weight in terms of polystyrene measured by a gel permeation chromatograph (GPC) method.
Specifically, a GPC measurement device (manufactured by Waters, trade name: Alliance GPC2000) was used as the measurement device. The solution to be injected was 240 μl of a 1,2,4-trichlorobenzene (including 300 ppm dibutylhydroxytoluene) solution having a concentration of 0.5 mg / ml, and the column was a mixed polystyrene gel column (manufactured by Tosoh Corporation) (Trade name: GMHHR-H (S) HT), and measurement was performed under the conditions of a column temperature of 145 ° C. and a flow rate of 1.0 ml / min. For detection, an infrared detector was used, and a wavelength of 3.41 μm was used.

(Toner particle size)
The volume average particle diameter Dv, the number average particle diameter Dp, and the particle diameter distribution Dv / Dp of the toner were measured with a particle diameter measuring machine (Beckman Coulter, trade name: Multisizer II). The measurement with this multisizer was performed under the conditions of an aperture diameter: 100 μm, a medium: Isoton II, a concentration of 10%, and a measurement particle number: 100,000.
Specifically, 0.2 g of toner was placed in a beaker, and an alkylbenzenesulfonic acid aqueous solution (manufactured by Fuji Film Co., Ltd., trade name: Drywell) was added as a dispersant. Then, 2 ml of the medium was added to wet the toner, 10 ml of the medium was further added, and the mixture was dispersed with an ultrasonic disperser for 1 minute, and then measured with the particle size measuring instrument.

(Toner storability)
10 g of toner was put in a sealable container (made of polyethylene, capacity: 100 ml), sealed, and then submerged in a thermostatic water tank maintained at a temperature of 55 ° C. After 8 hours, the container was taken out from the constant temperature water bath, and the toner in the container was placed on a 42 mesh sieve. At this time, the toner is gently taken out from the container and carefully transferred to a sieve so as not to destroy the toner aggregation structure in the container. The sieve on which the toner was placed was vibrated for 30 seconds under a condition of an amplitude of 1 mm using a powder measuring machine (manufactured by Hosokawa Micron Corporation, trade name: PowderTester), and then the weight of the toner remaining on the sieve was measured and agglomerated. The toner weight was used. The ratio (% by weight) of the weight of the aggregated toner to the weight of the toner initially placed in the container was calculated. Each sample was measured three times, and the average value was used as an index of storage stability.

(Volume specific resistance of toner)
3.9 g of toner is pressure-molded under a pressure of 100 kg / cm ² for 1 minute using a molding machine (trade name: BRM-30, manufactured by Maekawa Test Instruments Co., Ltd.), and a disk having a diameter of 5 cm and a thickness of 2 mm. A sample for measurement was obtained. The obtained measurement sample was measured under the conditions of a temperature of 30 ° C. and a frequency of 1 kHz with a dielectric loss measuring device (trade name: TRS-10 type, manufactured by Ando Electric Co., Ltd.), and a volume resistivity was obtained.

(Minimum toner fixing temperature (low-temperature fixability))
A fixing test was performed using a printer that was modified so that the temperature of the fixing roll portion of a commercially available non-magnetic one-component developing type printer (printing speed: 28 sheets of A4 size / 1 minute) could be changed. In the fixing test, black solid (print density 100%) is printed, the temperature of the fixing roll of the modified printer is changed, the toner fixing rate at each temperature is measured, and the relationship between temperature and fixing rate is obtained. I went.
The fixing rate was calculated from the ratio of the image density before and after the tape was peeled off in the black solid (printing density 100%) printing area. That is, when the image density before tape peeling is ID (front) and the image density after tape peeling is ID (back), the fixing ratio can be calculated by the following equation.
Fixing rate (%) = (ID (back) / ID (front)) × 100
Here, the tape peeling operation means that an adhesive tape (manufactured by Sumitomo 3M Co., Ltd., trade name: Scotch Mending Tape 810-3-18) is applied to the measurement portion of the test paper, and is pressed and adhered at a constant pressure. It is a series of operations for peeling the adhesive tape in a direction along the paper at a constant speed. The image density was measured using a reflection type image density meter (trade name: RD914, manufactured by Macbeth Co., Ltd.).
In this fixing test, the lowest fixing roll temperature at which the fixing rate exceeded 80% was evaluated as the minimum fixing temperature of the toner.

(Offset resistance of toner)
A commercially available non-magnetic one-component developing type printer (printing speed: 14 sheets of A4 size / 1 minute) was used so that the temperature of the fixing roll portion could be changed. In the offset resistance test, the temperature of the fixing roll of this modified printer is changed from 150 ° C. to 220 ° C. by 10 ° C., and the print has black solid (print density 100%) and white solid (print density 0%). The pattern was printed, the white solid part on the paper was observed at each temperature, and the presence or absence of offset was confirmed visually. When the temperature at which the offset at a high temperature occurred was less than 200 ° C., it was evaluated as “x”, when it was 200 ° C. to 220 ° C., and when it was 220 ° C. or more, it was evaluated as “good”.

(Durability of printing)
A commercially available non-magnetic one-component developing type printer (printing speed: 24 sheets of A4 size / 1 minute) was used. The toner is put into the developing device of this printer and left for 24 hours in a room temperature and normal humidity (N / N) environment at a temperature of 23 ° C. and a humidity of 50% RH, and then 17,000 sheets with a 1% print density in the same environment. Continuous printing was performed. Continuous printing is interrupted every 1,000 sheets, black solid printing (printing density 100%) is performed, and the printing density of the solid printing part is measured with a reflective image densitometer (product name: RD914, manufactured by Macbeth). It was measured. Further, after that, white solid printing (printing density 0%) is performed, the printer is stopped in the middle of the white solid printing, and the toner in the non-image area on the photoconductor after development is adhesive tape (manufactured by Sumitomo 3M, Product name: Scotch mending tape 810-3-18) and adhered to printing paper. Next, the whiteness (B) of the printing paper on which the adhesive tape was affixed was measured with a whiteness meter (manufactured by Nippon Denshoku). Similarly, an unused adhesive tape was affixed to the printing paper, the whiteness (A) was measured as a reference, and the whiteness difference (A)-(B) was defined as the fog value (%). Smaller values indicate better fogging.
The number of continuous prints capable of maintaining an image quality with a print density of 1.3 or more and a fog value of 5% or less was examined.

(Production Example 1) Wax A
(Catalyst production example)
(A) Production of (1,2'-dimethylsilylene) (2,1'-dimethylsilylene) bis (3-trimethylsilylmethylindenyl) zirconium dichloride In a 200 ml Schlenk bottle under a nitrogen stream, (1,2'- After adding 2.5 g (7.2 mmol) of dimethylsilylene) (2,1′-dimethylsilylene) bis (indene) and 100 ml of ether, the mixture was cooled to −78 ° C., and n-butyllithium (n-BuLi) Hexane solution (concentration 1.6 mol / l) 9.0 ml (14.8 mmol) was added, and the mixture was returned to room temperature and stirred for 12 hours.
The solvent was distilled off from the resulting solution, and the remaining solid was washed with 20 ml of hexane and then dried under reduced pressure to obtain (1,2′-dimethylsilylene) (2,1′-dimethylsilylene) bis (indene). Was obtained quantitatively as a white solid.

Next, the obtained lithium salt (6.97 mmol) of (1,2′-dimethylsilylene) (2,1′-dimethylsilylene) bis (indene) was dissolved in 50 ml of tetrahydrofuran (THF) in a Schlenk bottle. Then, 2.1 ml (14.2 mmol) of iodomethyltrimethylsilane was slowly added dropwise at room temperature and stirred for 12 hours.
After stirring, the solvent was distilled off and 50 ml of ether was added. Further, a saturated aqueous solution of ammonium chloride was added thereto, washed, the aqueous phase was separated, the organic phase was dried, the solvent was removed, and (1,2'-dimethylsilylene) (2,1'-dimethyl) Silylene) bis (3-trimethylsilylmethylindene) 3.04 g (5.9 mmol) was obtained (yield 84%).

The (1,2′-dimethylsilylene) (2,1′-dimethylsilylene) bis (3-trimethylsilylmethylindene) 3.04 g (5.9 mmol) obtained above and 50 ml of ether were placed in a Schlenk bottle under a nitrogen stream. The mixture was cooled to −78 ° C., 7.4 ml (11.8 mmol) of a hexane solution (1.6 mol / l) of n-butyllithium (n-BuLi) was added, and the mixture was returned to room temperature and stirred for 12 hours. did.
From the stirred solution, the solvent was distilled off, and the remaining solid was washed with 40 ml of hexane to obtain 3.06 g of an ether adduct of lithium salt.
When ¹ H-NMR of the ether adduct of this lithium salt was measured, the following results were obtained.
¹ H-NMR (90 MHz, THF-d8): δ 0.04 (s, —SiMe ₃ , 18H), 0.48 (s, —Me ₂ Si—, 12H), 1.10 (t, —CH ₃ , _{6H), 2.59 (s, -CH} 2 -, 4H), 3.38 (q, -CH 2 -, 4H), 6.2-7.7 (m, Ar-H, 8H)

Under a nitrogen stream, 3.06 g of the ether adduct of the lithium salt obtained above was suspended in 50 ml of toluene, cooled to −78 ° C., and 1.2 g of zirconium tetrachloride previously cooled to −78 ° C. (5 0.1 mmol) in toluene (20 ml) was added dropwise, and the mixture was returned to room temperature and stirred for 6 hours.
After the solvent of the obtained solution was distilled off, the remaining solid was recrystallized from dichloromethane to obtain (1,2'-dimethylsilylene) (2,1'-dimethylsilylene) bis (3-trimethylsilylmethylindenyl). 0.9 g (1.33 mmol) of yellow microcrystals of zirconium dichloride was obtained (yield 26%).
When ¹ H-NMR of this yellow microcrystal was measured, the following result was obtained.
¹ H-NMR (90 MHz, CDCl ₃ ): δ0.0 (s, -SiMe _3- , 18H), 1.02-1.12 (s, -Me ₃ Si-, 12H), 2.51 (dd, _{-CH 2 -, 4H), 7.1-7.6} (m, Ar-H, 8H)

(Monomer preparation)
An α-olefin (made by Idemitsu Kosan Co., Ltd., trade name: Linearlen 2024) is distilled under reduced pressure (2 to 14 mmHg) at a distillation temperature of 140 to 230 ° C., and the composition is C22: 63.5%, C24. : A 36.5% α-olefin fraction was obtained. The obtained α-olefin fraction was introduced into a heat-dried 5 liter Schlenk bottle and dehydrated with dry nitrogen and activated alumina for 8 hours.

(Α-olefin polymerization)
In a 10 liter autoclave that had been dried by heating, 5 liters of a dehydrated α-olefin fraction was added and the temperature was raised to a polymerization temperature of 75 ° C., and then 12 mmol of triisobutylaluminum was obtained in the above catalyst preparation example (1, 2′-dimethylsilylene) (2,1′-dimethylsilylene) bis (3-trimethylsilylmethylindenyl) zirconium dichloride 25 μmol (toluene slurry (20 μmol / mL, 1.25 mL)) and dimethylanilinium tetrakispentafluorophenylborate 100 μmol (toluene slurry (20 μmol / mL, 5 mL)) was added, 0.05 MPa of hydrogen was introduced, and the polymerization temperature was maintained for 4 hours to carry out the polymerization reaction.
After the completion of the polymerization reaction, the obtained reaction product was precipitated with acetone, and then the solvent was distilled off by heating and decompression to dryness to obtain 1.7 kg of α-olefin copolymer. did.

Example 1
78 parts of styrene and 22 parts of n-butyl acrylate as monovinyl monomers (Tg of copolymer obtained by copolymerizing these monomers = 50 ° C.), polymethacrylate macromonomer (Toa Manufactured by Synthetic Chemical Industry Co., Ltd., trade name: AA6, Tg = 94 ° C.) 0.3 part, divinylbenzene 0.7 part as a crosslinking monomer, t-dodecyl mercaptan 1.85 part as a molecular weight regulator, and black 7 parts of carbon black (trade name: # 25B, manufactured by Mitsubishi Chemical Corporation) as a colorant was wet pulverized using a media type wet pulverizer. In the mixture obtained by wet pulverization, 1 part of charge control resin (manufactured by Fujikura Kasei Co., Ltd., trade name: Acrybase FCA-207P) as a charge control agent and wax A (obtained in Production Example 1) as a release agent 8 parts of aliphatic hydrocarbon polymer) and 2 parts of wax B (manufactured by NOF Corporation, trade name: WEP6) were added, mixed and dissolved to obtain a polymerizable monomer composition.

  On the other hand, to an aqueous solution in which 8.6 parts of magnesium chloride is dissolved in 170 parts of ion-exchanged water, an aqueous solution in which 4.8 parts of sodium hydroxide is dissolved in 50 parts of ion-exchanged water is gradually added with stirring to obtain magnesium hydroxide. A colloidal dispersion was prepared.

  A polymerizable monomer composition is put into the magnesium hydroxide colloid dispersion (magnesium hydroxide colloid amount 3.5 parts) obtained as described above, and the mixture is further stirred, and t-butyl persulfate is used as a polymerization initiator there. 6 parts of oxy-isobutyrate (manufactured by NOF Corporation, trade name: Perbutyl IB) was added. The dispersion with the polymerization initiator added was dispersed at a rotational speed of 15,000 rpm with an in-line type emulsifying disperser (trade name: Ebara Milder MDN303V, manufactured by Ebara Seisakusho Co., Ltd.). Droplets were formed.

  The droplet-formed dispersion is placed in a reactor, and the polymerization reaction is carried out by raising the temperature to 95 ° C. After the polymerization conversion rate reaches almost 100%, methyl methacrylate (shell polymerizable monomer) 1 part of the resulting polymer (Tg = 105 ° C.) was added to the reactor. Subsequently, 2,2′-azobis (2-methyl-N- (2-hydroxyethyl) -propionamide) (manufactured by Wako Pure Chemical Industries, Ltd., trade name: VA-086, water-soluble) 0 as a polymerization initiator for shell .1 part was dissolved in 10 parts of water and added to the reactor. Furthermore, after maintaining the polymerization at 95 ° C. for 4 hours and continuing the polymerization, the reaction was stopped by cooling with water to obtain an aqueous dispersion of colored resin particles having a core-shell structure.

  While stirring the aqueous dispersion of the obtained colored resin particles, washing with an acid to which sulfuric acid is added until the pH becomes 4.5 or less (25 ° C., 10 minutes), followed by filtration and dehydration, and further drying. Then, dried colored resin particles were obtained.

  100 parts of dried colored resin particles, 1 part of silica fine particles hydrophobized with cyclic silazane (number primary average particle size: 7 nm) and silica fine particles hydrophobized with amino-modified silicone oil (number primary average particle size) : 35 nm) 1 part was added and mixed using a high-speed stirrer (trade name: Henschel mixer, manufactured by Mitsui Mining Co., Ltd.) to prepare a non-magnetic one-component toner for developing an electrostatic image. The test results are shown in Table 2.

(Example 2)
In Example 1, as a release agent, 8 parts of wax A and 6 parts of wax A instead of 2 parts of wax B and 4 parts of wax C (manufactured by NOF Corporation, trade name: WEP7) were used. An electrostatic image developing toner was prepared in the same manner as in Example 1. The test results are shown in Table 2.

(Example 3)
In Example 2, the toner for developing an electrostatic charge image was prepared in the same manner as in Example 2 except that the amount of wax added was changed to 18 parts of wax A and 2 parts of wax C, respectively. Prepared. The test results are shown in Table 2.

(Comparative Example 1)
In Example 1, an electrostatic charge image developing toner was prepared in the same manner as in Example 1 except that wax B was not used as the release agent and only 10 parts of wax A was used. The test results are shown in Table 2.

(Comparative Example 2)
In Example 1, an electrostatic charge image developing toner was prepared in the same manner as in Example 1 except that wax A was not used as the release agent and only 10 parts of wax B was used. The test results are shown in Table 2.

(Comparative Example 3)
In Example 1, instead of 8 parts of wax A and 2 parts of wax B, 8 parts of wax B and 2 parts of wax D (product name: PW130, manufactured by Nippon Seiki Co., Ltd.) were used as a release agent. Example 1 except that the dispersion of the polymerizable monomer composition or droplets thereof was heated and maintained at 50 ° C. while being heated from dissolution of the release agent to the temperature rise during polymerization. A toner for developing an electrostatic image was prepared in the same manner as described above. The test results are shown in Table 2.

(Comparative Example 4)
In Example 1, instead of 8 parts of wax A and 2 parts of wax B, 8 parts of wax C and 2 parts of wax E (product name: FT100, manufactured by Nippon Seiki Co., Ltd.) were used as a release agent. A toner for developing an electrostatic charge image was prepared in the same manner as in Example 1 except for the treatment. The wax E was not dissolved in the monomer, but was finely pulverized and dispersed by a wet pulverization process using a media-type wet pulverizer. The test results are shown in Table 2.

  The physical properties of the wax A obtained in the above production examples and the commercially available wax B, wax C, wax D, and wax E used in Examples or Comparative Examples of the present invention are shown in Table 1 below.

  Table 2 shows the results of Examples and Comparative Examples of the present invention.

(Summary of results)
From the test results described in Table 2, the following can be understood.
The toner of Comparative Example 1 using only wax A was excellent in storage stability and low-temperature fixability, but was inferior in offset resistance.
Further, in the toner of Comparative Example 2 using only wax B, the minimum fixing temperature was higher than that of Comparative Example 1, the printing durability was slightly deteriorated, and both the low temperature fixing property and the printing durability were insufficient.
Furthermore, the toner of Comparative Example 3 using both wax B and wax D, which is a paraffin wax, was insufficient in all of the characteristics of storage stability, low-temperature fixability, and printing durability.
In addition, the toner of Comparative Example 4 in which the wax C and the Fischer-Tropsch wax E are used in combination has a minimum fixing temperature higher than that of the toner of Comparative Example 1, and the printing durability tends to be slightly deteriorated. It was insufficient.
In contrast, the toners of the examples using the specific aliphatic hydrocarbon polymer and the low molecular weight wax specified in the present invention are excellent in offset resistance and excellent in storage stability, low-temperature fixability, and printing durability. Met.

  The electrostatic image developing toner obtained by the present invention can be used as a developer in an electrophotographic image forming apparatus such as a facsimile, a copying machine, and a printer.

Claims (6)

In an electrostatic charge image developing toner comprising colored resin particles containing a binder resin, a colorant, and a release agent,
The release agent is
(1) An aliphatic hydrocarbon polymer having a peak top molecular weight of 10,000 or more and a melting point of 70 ° C. or less, and (2) a low molecular weight wax having a peak top molecular weight of 5,000 or less. Toner for developing electrostatic image.   2. The electrostatic image developing toner according to claim 1, wherein the low molecular weight wax is an ester wax.   The toner for developing an electrostatic charge image according to claim 1, wherein the aliphatic hydrocarbon polymer has a melting point (TmD) equal to or lower than the melting point (TmD) of the low molecular weight wax.   The static hydrocarbon according to any one of claims 1 to 3, wherein the aliphatic hydrocarbon polymer is an α-olefin polymer obtained by polymerizing an α-olefin monomer having 10 or more carbon atoms. Toner for charge image development.   The content ratio of the aliphatic hydrocarbon polymer to the low molecular weight wax (aliphatic hydrocarbon polymer content / low molecular weight wax content) is 98/2 to 25/75. The toner for developing an electrostatic charge image according to any one of claims 1 to 4.   6. The electrostatic image developing toner according to claim 1, wherein the colored resin particles are produced by a wet method.