JP2007017962A - Toner for heat fixing and image forming apparatus using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a toner for heat fixing excellent in low-temperature fixability, hot-offset resistance, blocking resistance, etc., and capable of high-speed printing. <P>SOLUTION: The toner for heat fixing is obtained by coating core particles comprising a binder resin (a) and a colorant with a shell comprising a binder resin (b) and a silicone wax having repeating units (p) and (q), wherein the highest endothermic peak of the silicone wax obtained when its endothermic property is measured with a differential scanning calorimeter is at a temperature in a range of 30-120°C, and in its endothermic property measured with the differential scanning calorimeter, an endothermic peak area at ≤50°C is ≤45% of a total endothermic peak area. In the formula, R<SP>3</SP>s each represent a 1-6C linear or branched alkyl group or a 6-12C aryl group and may be different from each other, and R<SP>4</SP>represents a 6-100C linear or branched alkyl group. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a heat fixing toner used in electrophotographic copying machines, printers, and the like. More specifically, the present invention is excellent in low temperature fixing property, high temperature offset resistance, blocking resistance, etc., and obtains a high quality image at high speed. The present invention relates to a heat fixing toner that can be used.

  In recent years, electrophotographic technology is widely used not only in the field of copying machines but also in various printer fields in terms of immediacy and high image quality. The formation of a visible image by electrophotography is generally performed by first forming an electrostatic latent image on a photosensitive drum, then developing it with toner, transferring it to transfer paper, etc., and fixing it with heat or the like. . As a developing method at this time, a two-component developing method in which a carrier and a toner are mixed is generally used, or a one-component developing method in which a carrier is not used.

  In addition to the conventional melt kneading and pulverization method, a toner production method using a suspension polymerization method or an emulsion polymerization aggregation method has been proposed. According to these production methods called polymerization methods, it is easy to control the particle size of the toner, so it is possible to obtain a toner having a small particle size and a narrow particle size distribution, and an image with superior image quality compared to the toner obtained by the pulverization method. Obtainable.

  On the other hand, in recent years, with the widespread use of electrophotographic copying machines and printers, there has been a demand for high-speed image formation, and accordingly, low-temperature fixability is required for toner. Certainly, if a binder resin having a low softening point is used, the low-temperature fixability can be improved. However, although the low-temperature fixability can be improved by simply using a binder having a low softening point, a toner that is satisfactory in terms of high-temperature offset resistance and blocking resistance has not been obtained.

  As another method for improving the low-temperature fixability, a method of adding a wax to the toner is generally used. However, when a large amount of wax is added, the toner obtained has a wax even in the outermost layer, and there is a problem that the apparatus is soiled in the process of image formation. This is a problem common to the pulverization method and the polymerization method, and none of the production methods has been sufficiently solved.

  In order to solve such a problem, a toner is proposed in which the surface of wax-containing toner particles obtained by an emulsion polymerization aggregation method is coated with resin particles not containing wax (see, for example, Patent Document 1). In addition, in order to improve the fixing property and the stain resistance of the apparatus, an attempt has been made to co-add waxes having different properties to the toner (for example, see Patent Document 2).

  However, even with such a toner, when it is attempted to fix at a lower temperature, sufficient releasability cannot be obtained, and there is a problem in high temperature offset resistance and the like.

  On the other hand, as a toner for pressure fixing rather than heat fixing, a toner having a two-layer structure is known, and a toner containing a silicone resin in an outer layer is also known (for example, see Patent Document 3). However, the offset phenomenon in pressure fixing and the high temperature anti-offset phenomenon in heat fixing are completely different in mechanism, and the technology of pressure fixing toner is changed to a heat fixing roller for toner droplets melted at high temperature in heat fixing. Could not be diverted to prevent offset.

  Further, it is known that a silyl isocyanate compound is used in order to facilitate the formation of a two-layer structure in a heat fixing toner (see, for example, Patent Document 4). Therefore, the toner oil droplets can be prevented from being coalesced in the aqueous phase, and the construction of the produced toner is completely different. In other words, this technique reduces the variation in the charge amount while maintaining the dispersibility of the colorant, and facilitates the production of a toner having a uniform particle diameter. The silyl isocyanate compound is effective as a wax in the first place. Therefore, a toner for heat fixing having improved high temperature offset resistance and device contamination resistance while achieving low temperature fixing has not been achieved.

Japanese Patent Laid-Open No. 2002-082487. JP2003-043732A. JP-A-58-150968. Japanese Patent Laid-Open No. 06-175388.

  The present invention has been made in view of such background art, and its object is to provide a heat fixing toner that is excellent in low temperature fixability, high temperature offset resistance, blocking resistance and the like and is capable of high speed printing. It is in.

  As a result of intensive studies to solve the above problems, the present inventor obtains a heat fixing toner that solves the above problems by coating the core particles with a shell containing a specific wax and a binder resin. The present invention has been found.

  The present invention comprises the first invention and the second invention. 1st this invention has binder resin (b) and the following repeating unit (p) and (q) in the core particle containing binder resin (a) and a coloring agent, and is endothermic with a differential scanning calorimeter. In the endothermic characteristics obtained when measuring the endothermic characteristics with a differential scanning calorimeter, the endothermic peak area obtained when measuring the endothermic maximum peak temperature in the range of 30 to 120 ° C. is the total endothermic peak area. The present invention provides a heat fixing toner characterized in that a shell containing a silicon-based wax that is 45% or less is coated.

［式中、Ｒ^３は、互いに異なっていてもよい炭素数１〜６の直鎖若しくは分岐のアルキル基又は炭素数６〜１２のアリール基を表し、Ｒ^４は炭素数６〜１００の直鎖若しくは分岐のアルキル基を表す。］

[Wherein R ³ represents a linear or branched alkyl group having 1 to 6 carbon atoms which may be different from each other or an aryl group having 6 to 12 carbon atoms, and R ⁴ is a linear chain having 6 to 100 carbon atoms. Alternatively, it represents a branched alkyl group. ]

  In the second aspect of the invention, the core particles containing the binder resin (a) and the colorant are coated with the binder resin (b) and the shell containing the silicon wax represented by the general formula (1). The present invention provides a heat fixing toner characterized by the following.

［式中、Ｒ^１は炭素数２〜１０のアルキル基を示し、Ｒ^２は、炭素数１１以上のアルキル基を示す。ｋ＋ｍ＋ｎは１０〜１５０の整数であり、０≦ｍ／（ｋ＋ｍ＋ｎ）≦０．２、０．１≦ｎ／（ｋ＋ｍ＋ｎ）≦１を満たす。］

[Wherein, R ¹ represents an alkyl group having 2 to 10 carbon atoms, and R ² represents an alkyl group having 11 or more carbon atoms. k + m + n is an integer of 10 to 150, and satisfies 0 ≦ m / (k + m + n) ≦ 0.2 and 0.1 ≦ n / (k + m + n) ≦ 1. ]

  The present invention also provides an image forming apparatus using such a heat fixing toner.

  According to the present invention, it is possible to provide a thermal fixing toner that is excellent in low-temperature fixability, high-temperature offset resistance, blocking resistance, and the like and can obtain a high-quality image at high speed.

  The heat-fixing toner of the present invention has a configuration in which core particles are covered with a shell, and the core particles include at least a binder resin (hereinafter, the binder resin contained in the core particles is referred to as “binder resin (a)”). (Abbreviated) and a colorant.

  As the binder resin (a) for the heat fixing toner of the present invention, various known resins for toner can be used. For example, styrene resin, polyester resin, epoxy resin, polyurethane resin, vinyl chloride resin, polyethylene , Polypropylene, ionomer resin, silicone resin, rosin-modified maleic resin, phenol resin, ketone resin, ethylene-ethyl (meth) acrylate copolymer, polyvinyl butyral resin, and the like, and a mixture thereof may be used. Preferred binder resins (a) include styrene resins and polyester resins.

  The styrene resin is not particularly limited. For example, polystyrene, chloropolystyrene, poly-α-methylstyrene, styrene-chlorostyrene copolymer, styrene-propylene copolymer, styrene-butadiene copolymer, styrene-chloride. Vinyl copolymer, styrene-vinyl acetate copolymer, styrene-maleic acid copolymer, styrene-acrylic acid ester copolymer (styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer, styrene- Butyl acrylate copolymer, styrene-octyl acrylate copolymer, styrene-phenyl acrylate copolymer, etc.), styrene-acrylic ester-acrylic acid copolymer (styrene-methyl acrylate-acrylic acid copolymer) Styrene-ethyl acrylate-acrylic acid copolymer, Len-butyl acrylate-acrylic acid copolymer, styrene-octyl acrylate-acrylic acid copolymer, styrene-phenyl acrylate-acrylic acid copolymer, etc.), styrene-acrylic acid ester-methacrylic acid copolymer ( Styrene-methyl acrylate-methacrylic acid copolymer, styrene-ethyl acrylate-methacrylic acid copolymer, styrene-butyl acrylate-methacrylic acid copolymer, styrene-octyl acrylate-methacrylic acid copolymer, styrene- Phenyl acrylate-methacrylic acid copolymer, etc.), styrene-methacrylic acid ester copolymer (styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, styrene-butyl methacrylate copolymer, styrene- Octyl methacrylate copolymer, styrene-meta Phenyl acrylate copolymer), styrene-methacrylic acid ester-acrylic acid copolymer (styrene-methyl methacrylate-acrylic acid copolymer, styrene-ethyl methacrylate-acrylic acid copolymer, styrene-butyl methacrylate) -Acrylic acid copolymer, styrene-octyl methacrylate-acrylic acid copolymer, styrene-phenyl methacrylate-acrylic acid copolymer, etc.), styrene-methacrylic acid ester-methacrylic acid copolymer (styrene-methyl methacrylate) -Methacrylic acid copolymer, styrene-ethyl methacrylate-methacrylic acid copolymer, styrene-butyl methacrylate-methacrylic acid copolymer, styrene-octyl methacrylate-methacrylic acid copolymer, styrene-phenyl methacrylate-methacrylic acid Acid copolymer, etc.), steel Emissions -α- chloromethyl methyl acrylate copolymer, styrene - acrylonitrile - homopolymers or copolymers of styrene or styrene derivatives such as acrylic acid ester copolymer. These may be a mixture thereof.

  Further, a part or all of the acrylic acid and methacrylic acid may be substituted with substituted monocarboxylic acids such as α-chloroacrylic acid and α-bromoacrylic acid, fumaric acid, maleic acid, maleic anhydride, monobutyl maleate and the like. Those substituted with saturated dicarboxylic acids, anhydrides thereof or half esters thereof can also be suitably used.

  Among them, styrene-acrylic acid ester copolymer, styrene-acrylic acid ester-acrylic acid copolymer, styrene-acrylic acid ester-methacrylic acid copolymer, styrene-methacrylic acid ester copolymer, styrene-methacrylic acid ester- An acrylic acid copolymer, a styrene-methacrylic acid ester-methacrylic acid copolymer, and the like are preferable. In particular, styrene-acrylic acid ester-acrylic acid copolymer, styrene-acrylic acid ester-methacrylic acid copolymer, styrene-methacrylic acid ester-acrylic acid copolymer, styrene-methacrylic acid ester-methacrylic acid copolymer, etc. Those having an acid group as described above are more preferable because they are excellent in terms of toner fixability and durability, and the charge stability (particularly negative chargeability) of the toner is improved. Here, the ester group in the acrylic ester or methacrylic ester is not particularly limited, and examples thereof include alkyl esters having 1 to 8 carbon atoms such as methyl ester, ethyl ester, butyl ester, octyl ester, and phenyl ester.

  When the binder resin (a) is a styrene resin, the number average molecular weight in gel permeation chromatography (hereinafter abbreviated as “GPC”) is preferably 2000 or more, more preferably 2500 or more, and still more preferably. It is 3000 or more, preferably 50,000 or less, more preferably 40,000 or less, and further preferably 35,000 or less. The weight average molecular weight determined by GPC is preferably 10,000 or more, more preferably 30,000 or more, still more preferably 50,000 or more, preferably 200,000 or less, more preferably 120,000 or less, and still more preferably 8 It is desirable to be 10,000 or less. When the number average molecular weight and the weight average molecular weight of the styrenic resin are in the above ranges, the durability, storage stability, fixing property and the like of the toner are improved.

  The polyester resin used as the binder resin (a) is not particularly limited, but those obtained by polycondensation with a polyhydric alcohol component and a polycarboxylic acid component as main components are preferred.

  Among the polyhydric alcohol components, examples of the dihydric alcohol component include ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, neopentyl glycol, 1 Diols such as 1,4-butenediol, 1,5-pentanediol, 1,6-hexanediol, 1,4-cyclohexanedimethanol, dipropylene glycol, polyethylene glycol, polytetramethylene glycol; bisphenol A, hydrogenated bisphenol A, etherified bisphenols such as polyoxyethylenated bisphenol A and polyoxypropylenated bisphenol A, alkylene oxide adducts thereof, and other alcohol monomers. Those containing phenol A is preferably used.

  Among the polyvalent carboxylic acid components, examples of the divalent carboxylic acid component include maleic acid, fumaric acid, citraconic acid, itaconic acid, glutaconic acid, phthalic acid, isophthalic acid, terephthalic acid, naphthalenedicarboxylic acid, and diphenic acid. , Cyclohexanedicarboxylic acid, succinic acid, adipic acid, sebacic acid, azelaic acid, malonic acid, n-dodecenyl succinic acid, isododecenyl succinic acid, n-dodecyl succinic acid, isododecyl succinic acid, n-octenyl succinic acid, isooctenyl succinic acid Examples thereof include divalent carboxylic acid compounds such as acids, n-octyl succinic acid and isooctyl succinic acid; anhydrides or lower alkyl esters of these acids.

  Furthermore, the polyester resin may contain a trivalent or higher alcohol component and / or a trivalent or higher carboxylic acid component as a polycondensation component.

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

  Examples of the trivalent or higher carboxylic acid component include 1,2,4-benzenetricarboxylic acid (trimellitic acid), 1,2,5-benzenetricarboxylic acid, naphthalenetricarboxylic acid, butanetricarboxylic acid, hexanetricarboxylic acid, 1 , 3-dicarboxyl-2-methyl-2-methylenecarboxypropane, cyclohexanetricarboxylic acid, tetra (methylenecarboxyl) methane, octanetetracarboxylic acid, pyromellitic acid, embol dimer acid, and anhydrides of these acids, And lower alkyl esters.

  These trivalent or higher alcohol components and / or trivalent or higher carboxylic acid components are contained in an amount of 0.01 to 30 mol%, preferably 0.1 to 5 mol% in the total polymerizable monomer component constituting the polyester resin. It is preferable that The inclusion of a trivalent or higher alcohol component and / or a trivalent or higher carboxylic acid component is preferable because both low-temperature fixability required for low-energy fixing and durability required for image stability during continuous shooting are compatible.

  Further, the polycondensation component of the polyester resin may include monofunctional alcohols such as benzoic acid, salicylic acid, myristic acid, palmitic acid, stearic acid, and monofunctional carboxylic acids. Moreover, it can also have the segment which has chains other than ester bonds, such as a urethane bond and an amide bond, in the structure of a polyester-type resin.

  When the binder resin (a) is a polyester resin, the acid value is preferably 2 to 50 KOHmg / g, more preferably 3 to 30 KOHmg / g. When the acid value is less than the above range, the dispersibility of the colorant and the charge control agent may be lowered. If the acid value exceeds the above range, the stability of the toner charge amount may be impaired.

  When the binder resin (a) is a polyester resin, the number average molecular weight determined by GPC is preferably 2000 or more, more preferably 3000 or more, still more preferably 5000 or more, preferably 15000 or less, more preferably 13000. In the following, it is more desirable that it is 10,000 or less. The weight average molecular weight determined by GPC is preferably 10,000 or more, more preferably 30,000 or more, still more preferably 50,000 or more, preferably 200,000 or less, more preferably 120,000 or less, and still more preferably 8 It is desirable to be 10,000 or less. When the number average molecular weight and the weight average molecular weight of the polyester resin are in the above ranges, the durability, storage stability, fixability and the like of the toner are good.

  In the heat fixing toner of the present invention, various known colorants suitable for the toner can be used as the colorant contained in the core particles. For example, metal powder such as iron powder and copper powder, metal oxide such as bengara, etc. , Inorganic pigments such as carbons typified by carbon black such as furnace black and lamp black, azo-based pigments such as benzidine yellow and benzidine orange, precipitates with dye precipitants such as quinoline yellow, acid green and alkali blue And dyes such as rhodamine, magenta, and macalite green, acidic dyes such as precipitates with tannic acid, phosphomolybdic acid, etc., mordant dyes such as metal salts of hydroxyanthraquinones, phthalocyanine blue, copper phthalocyanine sulfonate, etc. Phthalocyanine, quinacridone red, quinacridone violet, etc. Examples include organic pigments such as quinacridone and dioxane, aniline black, azo dyes, naphthoquinone dyes, indigo dyes, nigrosine dyes, phthalocyanine dyes, polymethine dyes, and synthetic dyes such as di- and triarylmethane dyes. More than one species can be used in combination.

  When the heat fixing toner of the present invention is used as a full-color toner, an azo pigment (insoluble monoazo, insoluble disazo, condensed azo, etc.) or polycyclic pigment (isoindoline, isoindolinone) is used for yellow. Azolene (azo lake, insoluble monoazo, insoluble disazo, condensed azo, etc.), polycyclic pigment (quinacridone pigment, perylene pigment, etc.), etc. Examples of cyan pigments include phthalocyanine pigments and selenium pigments. The combination of the colorants may be appropriately selected in consideration of the hue and the like. I. Pigment yellow 74, C.I. I. Pigment yellow 93, C.I. I. At least one selected from CI Pigment Yellow 155 is C.I. I. Pigment red 238, C.I. I. Pigment red 269, C.I. I. Pigment red 57: 1, C.I. I. Pigment red 48: 2, C.I. I. At least one selected from CI Pigment Red 122 is C.I. I. Pigment blue 15, C.I. I. At least one selected from CI Pigment Blue 15: 3 is preferable as furnace black carbon as the black colorant. It is preferable to use a colorant that contains as little volatile impurities as possible.

In addition, the colorant may have magnetism, and as such a magnetic colorant, a ferromagnetic material exhibiting ferrimagnetism or ferromagnetism at around 0 to 60 ° C., which is a use environment temperature of a printer, a copying machine, etc. Specifically, for example, magnetite (Fe ₃ O ₄ ), maghemite (γ-Fe ₂ O ₃ ), an intermediate or mixture of magnetite and maghemite, M _x Fe _3-x O ₄ (where M is , Mg, Mn, Fe, Co, Ni, Cu, Zn, Cd)), hexagonal ferrite such as BaO.6Fe ₂ O ₃ , SrO.6Fe ₂ O ₃ , Y ₃ Fe ₅ O ₁₂ , garnet-type oxide such as _Sm 3 _Fe 5 _{O 12,} rutile-type oxide such as CrO _2, and, Cr, Mn, Fe, Co, among such metal or their ferromagnetic alloys such as Ni 0-6 ℃ it can be mentioned those exhibiting magnetism in the vicinity of, among others, magnetite, intermediates maghemite or magnetite and maghemite are preferred.

  The content of the colorant with respect to the entire core particles is not particularly limited as long as the obtained heat fixing toner is an amount sufficient to form a visible image by development. The content is preferably 1 to 20% by mass, more preferably 2 to 15% by mass, and particularly preferably 3 to 10% by mass. When two or more colorants are used in combination, the total amount is preferably within the above range.

  The toner for heat fixing of the present invention preferably contains a wax in the core particles (hereinafter, the wax contained in the core particles is abbreviated as “wax (A)”). By including the wax (A), the low-temperature fixability is improved, and a high-quality image can be obtained at high speed.

  The wax (A) is not particularly limited, but preferably has a surface tension of 28 mN / m or more, particularly preferably 29 mN / m or more, and more preferably 30 mN / m or more. Moreover, what is 40 mN / m or less is preferable, what is 38 mN / m or less is especially preferable, and what is 35 mN / m or less is still more preferable. The surface tension can be measured by appropriately selecting from general measuring methods such as Wilhelmi method (plate method), pendant drop method, bubble pressure method, contact angle method, etc. according to the properties of the wax.

  The molecular weight of the wax (A) is not particularly limited and may be a monomer, an oligomer, or a polymer. In the case of an oligomer or polymer, the weight average molecular weight is usually 500 or more, preferably 1000 or more, more preferably 2000 or more. It is usually 60,000 or less, preferably 30,000 or less, and more preferably 10,000 or less. When the weight average molecular weight of the wax (A) is less than the above range, the wax (A) is likely to bleed out (leak) from the toner and may cause filming to the photoconductor. In this case, the low-temperature fixability of the toner may be impaired.

  The position of the endothermic peak by DSC of the wax (A) is not particularly limited as long as it is easy to produce a toner containing the wax and the toner can be fixed at a sufficiently low temperature, but preferably 30 to 100 ° C., particularly preferably May have at least one of 40 to 90 ° C, more preferably 50 to 80 ° C. When the endothermic peak temperature of the wax (A) is less than the above range or does not have an endothermic peak, the wax may be exposed to the surface after fixing, causing stickiness, and the endothermic peak temperature is over the above range. And low temperature fixability may be inferior.

  The average dispersed particle size of the wax (A) in the core particles is usually 100 nm or more, preferably 120 nm or more, more preferably 150 nm or more, and usually 400 nm or less, preferably 300 nm or less, more preferably 250 nm or less. Is desirable. The dispersed particle diameter of the wax (A) in the core particles is measured by observation with a transmission electron microscope and is defined thereby. Specifically, the wax dispersion particle diameters reflected in 10 transmission electron micrographs at different observation locations are measured and all of them are averaged, and defined as such measurement. When the average dispersed particle size of the wax (A) is less than the above range, the heat resistance may deteriorate, and when it exceeds the above range, the low temperature fixability may deteriorate. Further, as a means for setting the average dispersed particle size of the wax (A) within the above range, it can be particularly suitably obtained if the core particles are produced by an emulsion polymerization aggregation method described later.

  The chemical structure of the wax (A) is not particularly limited, and specifically, olefin waxes such as low molecular weight polyethylene, low molecular weight polypropylene, and copolymerized polyethylene; paraffin wax; behenyl behenate, montanate ester, stearyl stearate Esters having a long-chain aliphatic group such as; esters or partial esters obtained from polyhydric alcohols such as glycerin, pentaerythritol, trimethylolpropane and long-chain fatty acids; higher fatty acids such as stearic acid; long eicosanols Chain aliphatic alcohols; Ketones having long chain alkyl groups such as distearyl ketone; Plant waxes such as hydrogenated castor oil and carnauba wax; Higher fatty acid amides such as oleic acid amide and stearic acid amide; Low molecular weight polyester It is done. The wax (A) may be used alone or in combination of two or more.

  Of these, hydrocarbon waxes such as olefin wax and paraffin wax; ester waxes such as esters having long chain aliphatic groups, esters obtained from polyhydric alcohols and long chain fatty acids, or partial esters are preferred.

  Among these hydrocarbon waxes, those having 20 to 100 carbon atoms are preferable, and those having 30 to 90 carbon atoms are particularly preferable. As the ester wax, those having 20 to 100 carbon atoms are preferable, and those having 30 to 90 carbon atoms are particularly preferable.

  Among esters having a long-chain aliphatic group, particularly preferred compounds include behenyl behenate and stearyl stearate. Further, among esters or partial esters obtained from polyhydric alcohols and long chain fatty acids, particularly preferred compounds include pentaerythritol tetrastearate or partial ester thereof, glycerin trimontanate ester or partial ester thereof, and the like. Can be mentioned.

  The content of the wax (A) is usually 1 part by weight or more, preferably 2 parts by weight or more, more preferably 4 parts by weight or more, and usually 40 parts by weight or less, preferably 35 parts by weight with respect to 100 parts by weight of the core particles. Or less, more preferably 30 parts by weight or less. When the content of the wax (A) in the core particle is less than the above range, the high temperature offset resistance may not be sufficient, and when it is above the range, the blocking resistance may not be sufficient. (A) may bleed out (leak).

  In the heat fixing toner of the present invention, the core particles may contain a charge control agent for imparting charge amount and charge stability. As the charge control agent, conventionally known compounds are used. For example, as the positive charge control agent, nigrosine dyes, quaternary ammonium salt compounds, triaminotriphenylmethane compounds, imidazole compounds, polyamine resins, etc. Negative charge control agents include azo complex compound dyes containing atoms such as Cr, Co, Al, Fe, and B, salicylic acid or alkylsalicylic acid complex compounds, curixarene compounds, metal salts or metal complexes of benzylic acid , Amide compounds, phenol compounds, naphthol compounds, phenolamide compounds, hydroxynaphthalene compounds such as 4,4′-methylenebis [2- [N- (4-chlorophenyl) amido] -3-hydroxynaphthalene], and the like.

  In a full color toner, it is necessary to select a colorless or light color tone of the charge control agent in order to avoid a color tone trouble as a toner. For the purpose of use, among the above, as a positive charge control agent Are preferably quaternary ammonium salt compounds, imidazole compounds, etc., and negative charge control agents include salicylic acid or alkylsalicylic acid complex compounds containing atoms such as Cr, Co, Al, Fe, B, and Zn, curix An allene compound or the like is preferable. Moreover, these mixtures may be sufficient. When the charge control agent is contained, the content is preferably from 0.01 to 10% by mass, and preferably from 0.1 to 5% by mass, based on the entire toner particles.

  In the heat fixing toner of the present invention, when magnetic powder is added to give magnetism from the viewpoints of scattering prevention and charge control while maintaining the characteristics as a non-magnetic toner, the magnetic powder (magnetic The content of the (colorant) is 0.2 to 10% by mass, preferably 0.5 to 8% by mass, and more preferably 1 to 5% by mass. When used as a magnetic toner, the content of the magnetic powder in the toner is usually 15% by mass or more, preferably 20% by mass or more, and usually 70% by mass or less, preferably 60% by mass or less. It is desirable. If the content of the magnetic powder is less than the above range, the magnetic force required for the magnetic toner may not be obtained, and if it exceeds the above range, it may cause poor fixing properties.

  In order to impart conductivity to the heat fixing toner of the present invention, conductive carbon black as the colorant component and other conductive materials may be added. The content of the conductive substance is preferably about 0.05 to 5% by mass in the toner.

  The toner for heat fixing of the present invention has a core containing at least a binder resin (hereinafter, the binder resin contained in the shell is abbreviated as “binder resin (b)”) and a silicon wax in the core particle having the above-described configuration. It is coated.

  The binder resin (b) is not particularly limited, and various known resins suitable for the binder resin contained in the core particle can be used. For example, those exemplified as the binder resin (a) constituting the core particle The same resin is preferably used. In the present invention, the binder resin (b) can be the same resin as the binder resin (a), but is 0.5 ° C. or higher than the Tg of the binder resin (a), preferably 1.5 ° C. or higher. More preferably, it has a Tg higher by 2 ° C. or more in terms of blocking resistance, storage stability and the like.

  Although it does not specifically limit as binder resin (b), Specifically, a styrene-acrylic acid ester copolymer, a styrene-acrylic acid ester-acrylic acid copolymer, a styrene-acrylic acid ester-methacrylic acid copolymer. At least one selected from styrene-methacrylic acid ester copolymer, styrene-methacrylic acid ester-acrylic acid copolymer, and styrene-methacrylic acid ester-methacrylic acid copolymer is preferable.

  The shell coated with the heat fixing toner of the first invention has the following repeating units (p) and (q), and has a maximum endothermic peak temperature obtained when the endothermic characteristics are measured with a differential scanning calorimeter. In the endothermic characteristics obtained when measuring the endothermic characteristics with a differential scanning calorimeter in the range of 30 to 120 ° C., a silicon wax having an endothermic peak area of 50 ° C. or less of 45% or less of the total endothermic peak area is an essential component. Contained as.

［式中、Ｒ^３は、互いに異なっていてもよい炭素数１〜６の直鎖若しくは分岐のアルキル基又は炭素数６〜１２のアリール基を表し、Ｒ^４は炭素数６〜１００の直鎖若しくは分岐のアルキル基を表す。］

[Wherein R ³ represents a linear or branched alkyl group having 1 to 6 carbon atoms which may be different from each other or an aryl group having 6 to 12 carbon atoms, and R ⁴ is a linear chain having 6 to 100 carbon atoms. Alternatively, it represents a branched alkyl group. ]

In the repeating units (p) and (q), R ³ represents a linear or branched alkyl group having 1 to 6 carbon atoms or an aryl group having 6 to 12 carbon atoms, which may be different from each other. A linear or branched alkyl group having 1 to 4 carbon atoms or an aryl group having 6 to 10 carbon atoms, which may be different from each other. Of these, those in which a part of R ³ is a methyl group are particularly preferred. The ratio in which R ³ is a methyl group is preferably 60% or more, more preferably 70% or more, particularly preferably 75% or more, and still more preferably 80% or more with respect to all R ³ .

In the repeating unit (q), R ⁴ represents a linear or branched alkyl group having 6 to 100 carbon atoms, preferably a linear or branched alkyl group having 12 to 80 carbon atoms, particularly preferably A linear or branched alkyl group having 18 to 60 carbon atoms.

  The silicon wax contained in the shell has a maximum endothermic peak temperature obtained when the endothermic characteristics are measured with a differential scanning calorimeter in the range of 30 to 120 ° C, but in the range of 40 to 110 ° C. Is preferable, and it is especially preferable that it exists in the range of 50-100 degreeC.

  Further, the silicon-based wax contained in the shell has an endothermic peak area of 50 ° C. or lower in the endothermic characteristics obtained when measuring the endothermic characteristics with a differential scanning calorimeter, but 45% or less of the total endothermic peak area, It is preferably 30% or less, and particularly preferably 25% or less.

  Furthermore, the copolymerization molar ratio of the repeating units (p) and (q) in the silicon-based wax contained in the shell is not particularly limited, but the repeating unit (p) with respect to the repeating units (p) and (q). The molar ratio preferably satisfies 1/10 to 4/5, and particularly preferably 1/4 to 2/3.

  The shell covered with the heat fixing toner of the second aspect of the invention contains a silicon wax represented by the general formula (1) as an essential component. By incorporating the silicon-based wax represented by the general formula (1) in the shell, the high-temperature offset resistance, blocking resistance, etc. can be improved even if the low-temperature fixability is improved by adjusting the composition and composition of the core particles. It is possible to provide a heat fixing toner that does not deteriorate the toner.

［式中、Ｒ^１は炭素数２〜１０のアルキル基を示し、Ｒ^２は、炭素数１１以上のアルキル基を示す。ｋ＋ｍ＋ｎは１０〜１５０の整数であり、０≦ｍ／（ｋ＋ｍ＋ｎ）≦０．２、０．１≦ｎ／（ｋ＋ｍ＋ｎ）≦１を満たす。］

[Wherein, R ¹ represents an alkyl group having 2 to 10 carbon atoms, and R ² represents an alkyl group having 11 or more carbon atoms. k + m + n is an integer of 10 to 150, and satisfies 0 ≦ m / (k + m + n) ≦ 0.2 and 0.1 ≦ n / (k + m + n) ≦ 1. ]

In the general formula (1), R ¹ represents an alkyl group having 2 to 10 carbon atoms, preferably an alkyl group having 2 to 7 carbon atoms, and particularly preferably an alkyl group having 3 carbon atoms, that is, n- A propyl group or an isopropyl group. In the general formula (1), R ² represents an alkyl group having 11 or more carbon atoms, preferably an alkyl group having 12 to 100 carbon atoms, and particularly preferably an alkyl group having 12 to 80 carbon atoms. .

R ¹ and R ² may have a branched structure, a cyclic structure, a network structure, that is, a partially crosslinked structure, in addition to a linear structure.

  Although k + m + n which is the number of repeating units shows the integer of 10-150, Preferably it is an integer of 15-120, Most preferably, it is an integer of 20-100.

The ratio of the repeating unit to which R ¹ is bonded in all repeating units, that is, m / (k + m + n) is 0.2 or less. m = 0, that is, those having no repeating unit to which R ¹ is bonded are also included in the silicon-based wax in the present invention. That is, in the general formula (1), 0 ≦ m / (k + m + n) ≦ 0.2. Preferably, 0.01 ≦ m / (k + m + n) ≦ 0.2, and particularly preferably 0.01 ≦ m / (k + m + n) ≦ 0.17. More preferably, m / (k + m + n) is 0.1 or less.

About the ratio which the repeating unit which R2 ^couple | bonded among all the repeating units, ie, n / (k + m + n), is 0.1 <= n / (k + m + n) <= 1. Preferably 0.2 ≦ n / (k + m + n) ≦ 0.8, and particularly preferably 0.3 ≦ n / (k + m + n) ≦ 0.7.

  The silicon wax of the second invention preferably has at least one endothermic peak due to DSC at 30 to 100 ° C, preferably 40 to 90 ° C, more preferably 50 to 80 ° C. When the endothermic peak temperature of the silicon-based wax is less than the above range or has no endothermic peak, the wax tends to be sticky by being exposed to the surface after fixing, and if the endothermic peak temperature exceeds the above range, the temperature is low. The fixability tends to be inferior.

  Hereinafter, the “present invention” including the first present invention and the second present invention will be described. The following description is common to the first invention and the second invention unless otherwise specified. The surface tension of the silicon-based wax in the present invention is not particularly limited, but is preferably 35 mN / m or less, particularly preferably 30 mN / m or less, and further preferably 28 mN / m or less. Moreover, 15 mN / m or more is preferable, 18 mN / m or more is especially preferable, and 20 mN / m or more is still more preferable. By covering the core particles with a shell containing a silicon wax having a surface tension in the above range, the fixing temperature range is widened and the fixing property is improved.

  The form of the silicon-based wax is not particularly limited as long as it is contained in the shell, but is preferably contained in a dispersed state in the binder resin (b). As for the dispersed state, the average dispersed particle size of the dispersed particles is preferably 100 nm or more, particularly preferably 120 nm or more, and further preferably 150 nm or more. Further, it is preferably 400 nm or less, particularly preferably 300 nm or less, and further preferably 250 nm or less. Here, the measurement method and the definition of the average dispersed particle size of the dispersed particles are the same as those described above for the wax (A), which is performed by observation with a transmission electron microscope. When the dispersed particle diameter of the silicon-based wax is less than the above range, the fixability may be lowered, and when it is over the above range, the blocking resistance may be lowered.

  The content of the silicon-based wax is not particularly limited, but is preferably 0.01% by mass or more, particularly preferably 0.05% by mass or more, and further preferably 0.08% by mass or more based on the entire toner particles. Further, it is preferably 2% by mass or less, particularly preferably 1% by mass or less, and further preferably 0.5% by mass or less, based on the whole toner particles.

  Further, the content of the silicon-based wax is preferably 0.5% by mass or more, particularly preferably 0.8% by mass or more, and further preferably 1% by mass or more with respect to the entire shell. Moreover, it is preferably 15% by mass or less, particularly preferably 10% by mass or less, and further preferably 8% by mass or less, based on the whole shell. When the content of the silicon-based wax is less than the above range, the releasability may be lowered, and when it is over the above range, the blocking resistance may be lowered.

  The shell of the present invention may further contain components other than the binder resin (b) and the silicon wax within a range not impairing the effects of the present invention. Although such components are not limited, for example, there are a colorant contained in the core particles, a charge control agent and various internal additives that can be contained in the core particles as necessary. Can be mentioned.

  Further, the shell of the present invention may contain a wax other than the silicon-based wax, and examples thereof include those mentioned for the wax (A). However, when a large amount of wax other than silicon-based wax is contained in the shell, the releasability and blocking resistance may decrease. 6 mass% or less is preferable and it is especially preferable that it is 3 mass% or less.

  The method for producing the heat fixing toner of the present invention will be described in detail below.

  The method for producing the core particles of the heat fixing toner of the present invention is not limited, and dry methods such as melt kneading and pulverization methods, polymerization methods such as suspension polymerization methods and emulsion polymerization aggregation methods, and wet methods such as resin dissolution suspension methods. Any manufacturing method can be used. Among these, from the viewpoint of easy control of the particle size distribution and circularity of the toner to be obtained, and further from the viewpoint of ease of subsequent shell coating, it is preferably produced by a polymerization method or a wet method. It is particularly preferable to prepare by an emulsion polymerization aggregation method.

  The method for covering the core particles with the shell is not particularly limited, but it is preferable to carry out by causing a dispersion of resin fine particles containing the binder resin (b) and the silicon wax to act on the dispersion of the core particles.

  Hereinafter, it explains in detail for every manufacturing method of core particles. When the core particles of the heat fixing toner of the present invention are produced by a melt-kneading pulverization method, the production can be performed according to a conventionally known method. That is, usually, the binder resin (a), the colorant, and the wax (A) added as necessary, the charge control agent, the internal additive and the like are uniformly dispersed and mixed in a mixer, Melt and knead the mixture with a Banbury mixer, CM mixer, closed kneader, or single or twin screw extruder, etc., cool, coarsely pulverize with a crusher, hammer mill, etc., and finely pulverize with a jet mill, high-speed rotor rotary mill, etc. It can be obtained by a classifying method using an air classifier (for example, an inertia class elbow jet, a centrifugal class microplex, a DS separator, etc.). At this time, the raw materials may be dispersed and blended at the same time, but may be dispersed and blended in multiple stages by changing the blending timing of some raw materials. Furthermore, you may add a part of raw materials in the process in the middle of melt-kneading.

  There is no particular limitation on the method of coating the shell on the core particles obtained by the melt-kneading pulverization method. For example, after the core particles are dispersed in water in the presence of a surfactant or the like, emulsion polymerization described later is performed. The method of coating | covering by the method similar to the coating method in the aggregation method is mentioned. Alternatively, the components constituting the shell are dissolved or dispersed in an organic solvent, and the solution or dispersion is applied to the core particles by dip coating, spray coating, etc., and then dried by spray drying, fluidized bed, air flow transfer, or the like. Methods and the like.

  When the core particles of the heat fixing toner of the present invention are produced by suspension polymerization, they can be produced according to a conventionally known method. That is, usually, the polymerizable monomer, the polymerization initiator, the colorant, the wax (A) constituting the binder resin (a) in the aqueous medium, the charge control agent added as necessary, and the inner A component such as an additive can be obtained by suspending and dispersing an appropriate particle size using a disperser such as a disperser and then polymerizing the polymerizable monomer.

  The method for coating the shell onto the core particles obtained by the suspension polymerization method is not limited, but, for example, the core particles are dispersed in water and the same method as the coating method in the emulsion polymerization aggregation method described later is adopted. Can do. Alternatively, after the core particles are once filtered, the same coating method as that for the core particles obtained by the melt-kneading pulverization method can be employed.

  When the core particles of the heat fixing toner of the present invention are produced by the resin dissolution suspension method, they can be produced according to a conventionally known method. In the resin dissolution suspension method, the binder resin (a), the polymerization initiator, the colorant, the wax (A), and components such as a charge control agent and an internal additive that are added as necessary are used in an organic solvent. In this method, core particles are produced by dissolving or dispersing, dispersing the solution or dispersion in a poor solvent such as water to the size of toner particles, and distilling off the organic solvent in that state.

  The method for coating the core on the core particles obtained by the resin dissolution suspension method in this way is not limited. For example, for the dispersion of the core particles obtained by distilling off the organic solvent, A similar method can be taken. Alternatively, after the core particles are once filtered, the same coating method as that for the core particles obtained by the melt-kneading pulverization method can be employed.

  In the present invention, the emulsion polymerization aggregation method means a production method having a step of aggregating the polymer primary particles after obtaining an emulsion containing the polymer primary particles as a binder resin by the emulsion polymerization method. A method for producing the core particles of the heat fixing toner of the present invention by the emulsion polymerization aggregation method is described below.

  In the emulsion polymerization aggregation method, usually, a polymerizable monomer constituting the polymer primary particles is emulsified in an aqueous medium containing a polymerization initiator and an emulsifier, and the polymerizable monomer is polymerized with stirring. Then, a colorant and, if necessary, a charge control agent are added to the obtained polymer primary particle emulsion to aggregate the polymer primary particles to form aggregates of primary particles, Use core particles.

  Here, the addition method of the wax (A) is a method of adding it as a seed at the time of emulsion polymerization to contain it in the polymer primary particles, a method of adding it at the time of agglomeration of the polymer primary particles, and co-aggregating them. Any of the methods may be used. Among these, it is particularly preferable to add substantially all of the wax (A) as a seed during emulsion polymerization. By adding the wax (A) as a seed at the time of emulsion polymerization, the wax (A) is finely and uniformly dispersed in the toner, so that deterioration of chargeability and heat resistance of the toner can be suppressed.

  As a method of coating the shell with the core particles, a resin fine particle (hereinafter simply referred to as “resin fine particle”) emulsion constituting the shell is produced by the same method as the method of producing the polymer primary particles, Is mixed with core particles, which are aggregates of primary particles, the surface of the core particles is coated with resin fine particles, and the aggregate is heated to produce a heat fixing toner in which the core particles are coated with a shell. Is done.

  Here, as a method of containing the silicon-based wax in the shell, a method of preliminarily containing the resin fine particles in the resin fine particles by adding them as seeds during the emulsion polymerization of the resin fine particles, or coating (aggregating) the resin fine particles on the core particles. The method of adding and coaggregating at the time etc. is mentioned, Any of them may be mentioned. Among these, it is preferable to use silicon wax as a seed during emulsion polymerization of resin fine particles. That is, the resin fine particles are preferably fine particles containing the binder resin (b) obtained by emulsion polymerization using silicon wax as a seed. By adding silicone wax as a seed during emulsion polymerization, the silicone wax is finely and evenly dispersed in the binder resin (b), that is, in the shell, thus preventing deterioration of blocking resistance and equipment contamination. can do.

  Hereinafter, a method for obtaining the core particles by the emulsion polymerization aggregation method will be described in more detail.

  In the polymer primary particles, the polymerizable monomer used as the raw material for the binder resin is the polymerizable monomer mentioned as the raw material for the styrenic resin in the binder resin (a), as long as it is suitable for emulsion polymerization. Although there is no particular limitation, for example, styrenes such as styrene, methylstyrene, chlorostyrene, dichlorostyrene, p-tert-butylstyrene, pn-butylstyrene, pn-nonylstyrene, methyl acrylate, acrylic acid Ethyl, propyl acrylate, n-butyl acrylate, isobutyl acrylate, hydroxyethyl acrylate, ethyl hexyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, hydroxy methacrylate Ethyl, methak Examples include (meth) acrylic acid esters such as ethylhexyl sulfate, acrylamide, N-propylacrylamide, N, N-dimethylacrylamide, N, N-dipropylacrylamide, N, N-dibutylacrylamide, and acrylic acid amide. Styrene, butyl acrylate and the like are particularly preferable. These polymerizable monomers may be used alone or in combination.

  In addition, the polymerizable monomer constituting the polymer primary particles is a polymerizable monomer having a Bronsted acidic group (hereinafter abbreviated as “acidic monomer”) together with or in place of the polymerizable monomer, and It is also preferable to use a polymerizable monomer having a Bronsted basic group (hereinafter abbreviated as “basic monomer”) as a raw material polymerizable monomer. Examples of acidic monomers include polymerizable monomers having a carboxyl group such as acrylic acid, methacrylic acid, maleic acid, fumaric acid and cinnamic acid, polymerizable monomers having a sulfonic acid group such as sulfonated styrene, and vinylbenzenesulfonamide. Examples thereof include polymerizable monomers having a sulfonamide group. In addition, as the basic monomer, an aromatic vinyl compound having an amino group such as aminostyrene, a nitrogen-containing heterocyclic ring-containing monomer such as vinylpyridine or vinylpyrrolidone, or an amino group such as dimethylaminoethyl acrylate or diethylaminoethyl methacrylate ( And (meth) acrylic acid esters. These acidic monomers and basic monomers may be used alone or in combination, and may exist as a salt with a counter ion.

  When an acidic monomer or a basic monomer is used as the polymerizable monomer constituting the polymer primary particle, the total amount of the acidic monomer and the basic monomer is based on 100 parts by weight of the total polymerizable monomer constituting the polymer primary particle. The amount is preferably 0.05 parts by weight or more, more preferably 0.5 parts by weight or more, still more preferably 1 part by weight or more, preferably 10 parts by weight or less, more preferably 5 parts by weight or less. Thus, by using an acidic monomer or a basic monomer, the dispersion stability of the polymer primary particles may be improved.

  Furthermore, a polyfunctional monomer can also be used as the polymerizable monomer constituting the polymer primary particles. Examples of the multifunctional monomer include divinylbenzene, hexanediol diacrylate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, neopentyl glycol dimethacrylate, neopentyl glycol acrylate, diallyl phthalate, and the like. It is also possible to use a polymerizable monomer having a reactive group in a pendant group, such as glycidyl methacrylate, methylol acrylamide, acrolein and the like. Among these, radical polymerizable bifunctional monomers are preferable, and divinylbenzene and hexanediol diacrylate are particularly preferable. These polyfunctional monomers may be used alone or in combination.

  When a polyfunctional monomer is used as the polymerizable monomer constituting the polymer primary particles, the content thereof is preferably 0.005 parts by weight with respect to 100 parts by weight of the total polymerizable monomers constituting the polymer primary particles. More preferably, it is 0.1 parts by weight or more, more preferably 0.2 parts by weight or more, preferably 5 parts by weight or less, more preferably 3 parts by weight or less, and even more preferably 1 part by weight or less. preferable. By using a polyfunctional monomer in this way, the fixability may be improved.

  Examples of polymerization initiators include, for example, hydrogen peroxide; persulfates such as potassium persulfate, sodium persulfate, and ammonium persulfate; and a redox initiator that combines these persulfates as a component with a reducing agent such as acidic sodium sulfite. A water-soluble polymerization initiator such as 4,4′-azobiscyanovaleric acid, t-butyl hydroperoxide, cumene hydroperoxide, etc., and a reducing agent such as ferrous salt containing these water-soluble polymerizable initiators as one component; Combined redox initiators; organic peroxides such as benzoyl peroxide, lauroyl peroxide; 2,2'-azobisisobutyronitrile, 2,2'-azobis (2,4-dimethylvaleronitrile), etc. 1 type or 2 types or more of azo compounds etc. are 0.1 to 3 weight part normally with respect to 100 weight part of polymerizable monomers. Used. Of these, hydrogen peroxide, organic peroxides, and azo compounds are preferable as the initiator. These polymerization initiators may be added to the polymerization system before, simultaneously with, or after the addition of the polymerizable monomer, and these addition methods may be combined as necessary.

  Any of the polymerization initiators may be added to the polymerization system before, simultaneously with, or after the addition of the polymerizable monomer, and these addition methods may be combined as necessary.

  In addition, a known chain transfer agent can be used as necessary. Specific examples of the chain transfer agent include t-dodecyl mercaptan, 2-mercaptoethanol, diisopropyl xanthogen, carbon tetrachloride, trichlorobromomethane, and the like. Is mentioned. The chain transfer agent may be used alone or in combination of two or more, and is usually used in a range of 5% by mass or less based on the total polymerizable monomer.

  The emulsifier used in the emulsion polymerization is not particularly limited and known ones can be used. One or more emulsifiers selected from a cationic surfactant, an anionic surfactant, and a nonionic surfactant are used. Can be used in combination.

  Examples of the cationic surfactant include dodecyl ammonium chloride, dodecyl ammonium bromide, dodecyl trimethyl ammonium bromide, dodecyl pyridinium chloride, dodecyl pyridinium bromide, hexadecyl trimethyl ammonium bromide, and examples of the anionic surfactant include And fatty acid soap such as sodium stearate and sodium dodecanoate, sodium dodecyl sulfate, sodium dodecylbenzenesulfonate, sodium lauryl sulfate and the like. Nonionic surfactants include, for example, polyoxyethylene dodecyl ether, polyoxyethylene hexadecyl ether, polyoxyethylene nonyl phenyl ether, polyoxyethylene lauryl ether, polyoxyethylene sorbitan monooleate ether, monodecanoyl sucrose, etc. Is mentioned. Of these, alkali metal salts of linear alkylbenzene sulfonic acids such as sodium dodecylbenzene sulfonate are preferred.

  The amount of the emulsifier is usually 0.1 to 10 parts by weight with respect to 100 parts by weight of the polymerizable monomer, and these emulsifiers include, for example, partially or completely saponified polyvinyl alcohols such as polyvinyl alcohol. One type or two or more types of cellulose derivatives such as hydroxyethyl cellulose can be used in combination as protective colloids.

  In addition, the addition of the polymerizable monomer to the reaction system in the emulsion polymerization may be any of batch addition, continuous addition, and intermittent addition, but from the viewpoint of reaction control, continuous addition is preferable. Moreover, when using a several polymerizable monomer, the addition of each polymerizable monomer may be added separately, or a plurality of polymerizable monomers may be mixed in advance and added simultaneously. Furthermore, it is also possible to change the polymerizable monomer composition during the addition of the polymerizable monomer. The addition of the emulsifier to the reaction system may be any of batch addition, continuous addition, and intermittent addition. In addition to the emulsifier and the polymerization initiator, a pH adjuster, a polymerization degree adjuster, an antifoaming agent, and the like can be appropriately added to the reaction system.

  In the present invention, when the wax (A) is used as a seed during emulsion polymerization, the volume average particle diameter of the seed wax is usually 100 nm or more, preferably 120 nm or more, more preferably 150 nm or more, and usually 400 nm or less, preferably It is 300 nm or less, more preferably 250 nm or less.

  In emulsion polymerization, the above polymerizable monomers are polymerized in the presence of a polymerization initiator, and the polymerization temperature is usually 50 to 120 ° C, preferably 60 to 100 ° C, and more preferably 70 to 90 ° C.

  The volume average particle diameter of the polymer primary particles obtained by emulsion polymerization is usually 100 nm or more, preferably 120 nm or more, more preferably 150 nm or more, and usually 400 nm or less, preferably 300 nm or less, more preferably 250 nm or less. It is desirable. The volume average particle diameter is measured using Microtrack UPA manufactured by Nikkiso Co., Ltd. If the particle size is less than the above range, it may be difficult to control the aggregation rate in the aggregation process. If the particle size exceeds the above range, the particle size of the toner obtained by aggregation tends to be large. It may be difficult to obtain.

  In the present invention, Sp and Tg of the binder resin (a) contained in the polymer primary particles are preferably in the range described in the general item of the binder resin (a), and the number average molecular weight measured by GPC in terms of styrene. The weight average molecular weight is preferably in the range described in the styrenic resin.

  Furthermore, at least one of the peak molecular weights in GPC of the polymer primary particles in the present invention is preferably 3000 or more, more preferably 10,000 or more, still more preferably 30,000 or more, preferably 100,000 or less, more preferably It is preferably 70,000 or less, more preferably 60,000 or less. When the peak molecular weight is in the above range, the durability, storage stability, and fixability of the toner are good. Here, as the peak molecular weight, a value converted to polystyrene is used, and components insoluble in a solvent are excluded in measurement.

  The polymer primary particles in the present invention can be used in combination with a plurality of different polymer primary particles obtained as described above. Furthermore, in the production method of the present invention, a resin obtained by a polymerization method different from emulsion polymerization can be used in combination as polymer primary particles, and the volume average particle size of such a resin is usually 0.00. It is desirable to use a film having a thickness of 02 μm or more, preferably 0.05 μm or more, more preferably 0.1 μm or more, and usually 3 μm or less, preferably 2 μm or less, more preferably 1 μm or less. Examples of such particles include, in addition to particles having the same composition as that obtained by emulsion polymerization, vinyl monomers such as vinyl acetate, vinyl chloride, vinyl alcohol, vinyl butyral, and vinyl pyrrolidone. Homopolymers or copolymers, saturated polyester resins, polycarbonate resins, polyamide resins, polyolefin resins, polyarylate resins, polysulfone resins, polyphenylene ether resins, and other thermoplastic resins, and unsaturated polyester resins, phenol resins, epoxies Examples thereof include particles made of a thermosetting resin such as a resin, a urethane resin, and a rosin-modified maleic resin, and two or more of these may be used in combination.

  In the production of toner particles by the emulsion polymerization aggregation method, an additive such as a colorant and, if necessary, an emulsion of a wax (A) and a charge control agent are added to the emulsion of the primary polymer particles obtained by the emulsion polymerization. Addition and then stirring and mixing with a disperser, mixer, etc., for example, heating, electrolyte addition, pH adjustment, addition of a curing agent, etc., to reduce the dispersion stability of the polymer primary particles as an emulsion, primary particles A process for aggregating each other is performed to form an aggregate, and subsequently, primary particles in the aggregate are aged (fused) and stabilized by heat treatment.

  The colorant is preferably used in the state of being emulsified in water in the presence of an emulsifier, and the volume average particle diameter of the colorant particles is preferably 0.01 to 3 μm.

  In the present invention, when the wax (A) is added as an emulsion during aggregation, the volume average particle size of the wax (A) is usually 100 nm or more, preferably 120 nm or more, more preferably 150 nm or more, usually 400 nm or less, preferably It is desirable that the thickness is 300 nm or less, more preferably 250 nm or less.

  When the charge control agent is incorporated in the toner in the emulsion polymerization aggregation method, the charge control agent is added together with the polymerizable monomer during emulsion polymerization, or is added in the aggregation step together with the polymer primary particles and the colorant. The blended primary particles, the colorant, and the like can be blended by a method of adding them after agglomeration to obtain a particle size suitable for a toner. Of these, it is preferable to emulsify and disperse the charge control agent in water using an emulsifier, and add it as a dispersion having a volume average particle size of 0.01 to 3 μm to the aggregation step.

The electrolyte in the case of agglomerating by adding an electrolyte may be either an organic salt or an inorganic salt, but a monovalent or divalent or higher polyvalent metal salt is preferably used. Specifically, NaCl, KCl, LiCl, Na ₂ SO ₄ , K ₂ SO ₄ , Li ₂ SO ₄ , MgCl ₂ , CaCl ₂ , MgSO ₄ , CaSO ₄ , ZnSO ₄ , Al ₂ (SO ₄ ) ₃ , Fe ₂ (SO ₄ ) ₃ , CH ₃ COONa, C ₆ H ₅ SO ₃ Na, and the like. Of these, inorganic salts having a divalent or higher polyvalent metal cation are preferred.

  The amount of the electrolyte to be added varies depending on the type of the electrolyte, but is usually 0.05 to 25 parts by weight, preferably 0.1 to 15 parts by weight, and more preferably 0.8 to 100 parts by weight of the solid component of the mixed dispersion. 1 to 10 parts by weight. When the electrolyte is added and the amount of electrolyte added is less than the above range, the progress of the agglomeration reaction is slow, and a fine powder of 1 μm or less remains after the agglomeration reaction, or the average of the obtained particle aggregates If the particle size does not reach the target particle size, the particle size may exceed the above range. If the particle size exceeds the above range, rapid aggregation tends to occur, making it difficult to control the particle size. May cause problems such as the inclusion of undefined or irregular shapes.

  In addition, 20-60 degreeC is preferable and 30-55 degreeC is more preferable when the aggregation temperature in the case of adding electrolyte and performing aggregation.

  In the present invention, the binder resin (b) and the silicon-based wax in the resin fine particles for constituting the shell are as described above, but the production method also includes the polymer primary particles for producing the core particles. A method similar to the manufacturing method can be applied. In the following, it is distinguished from “polymer primary particles” at the time of core particle production, and the corresponding one is called “resin fine particles” in shell production.

  In the preparation of the shell of the present invention, when a silicon wax is used as a seed during the emulsion polymerization of the binder resin (b), the volume average particle diameter of the seed wax is preferably 100 nm or more, particularly preferably 120 nm or more. Preferably, it is 150 nm or more. Further, it is preferably 400 nm or less, particularly preferably 300 nm or less, and further preferably 250 nm or less. When the particle size is too small, the fixability may be lowered, and when the particle size is too large, the blocking resistance may be lowered.

  The volume average particle size of the resin fine particles obtained by emulsion polymerization is usually 100 nm or more, preferably 120 nm or more, more preferably 150 nm or more, and usually 400 nm or less, preferably 300 nm or less, more preferably 250 nm or less. . If the particle size is less than the above range, it may be difficult to control the aggregation rate in the aggregation process. If the particle size exceeds the above range, the particle size of the toner obtained by aggregation tends to be large. It may be difficult to obtain.

  In the present invention, when a silicone wax emulsion is added during coating of the shell component, the volume average particle size of the silicone wax is usually 100 nm or more, preferably 120 nm or more, more preferably 150 nm or more, and usually 400 nm or less. The thickness is preferably 300 nm or less, and more preferably 250 nm or less, for the same reason as when silicon wax is used as a seed.

  Further, as a method of coating the core particles with resin fine particles, and if necessary, silicon wax and other coating components, a core component obtained by agglomeration as described above is added to the core particles, and the core particles are added. The same aggregating treatment as in the particle production method can be performed.

  Heating is preferably performed in order to fuse and stabilize the particles having the core particles and the resin fine particles that have undergone the aggregation process in this way (hereinafter, this process is abbreviated as “aging process”). The temperature of the aging step is preferably higher than the higher Tg of the binder resin (a) and the binder resin (b), and more preferably 5 ° C. higher than the higher Tg. Moreover, the temperature below 80 degreeC temperature higher than this Tg is preferable, and the temperature below 50 degreeC temperature is especially preferable. The heating time is not particularly limited, but is preferably 1 to 6 hours. By such heat treatment, the polymer primary particles and other primary particles in the aggregate are fused and integrated, and the particle shape of the toner in which the core particles are coated with the resin fine particle layer is also close to a sphere.

  The core particles may be subjected to an aging step in advance before the core particles are coated by aggregation of the resin fine particles. Also in this case, it is preferable that the aging process is performed again after the resin particles are coated on the core particles. It is preferable to ripen the core particles in advance, since the circularity of the core particles is increased, so that the resin particles can be uniformly coated on the core particles, so that the blocking resistance, the fixing property and the like are improved.

  In addition to the general description of the average dispersed particle size of the wax (A) in the core particles described above, in the emulsion polymerization aggregation method, the average dispersed particle size of the wax (A) in the core particles after the aging process in particular. Is preferably 0.1 μm or more, particularly preferably 0.5 μm or more, more preferably 0.8 μm or more, preferably 3 μm or less, particularly preferably 2.5 μm or less, more preferably 2 μm or less. Here, the measurement method and the definition of the average dispersed particle diameter are those obtained by observation with a transmission electron microscope as described above. If it is less than this range, the fixability may be lowered, and if this range is exceeded, blocking resistance and storage stability may be lowered.

  The average particle size of the toner particles thus obtained is preferably from 3 to 15 μm, particularly preferably from 4 to 10 μm. Here, in the present invention, the average particle diameter of the toner particles is a value measured using a multisizer (manufactured by Coulter).

  The heat fixing toner of the present invention is preferably a heat fixing toner by further blending and adhering externally added fine particles to the surface of the toner particles produced as described above. As the externally added fine particles used in the present invention, known inorganic and organic fine particles can be used, which may be negatively charged or positively charged, and these may be used in combination. The toner is preferably negatively charged. Among these, at least one kind of negatively chargeable externally added fine particles is preferable.

  Examples of negatively charged externally added fine particles include metal oxides and hydroxides such as alumina, silica, titania, zinc oxide, zirconium oxide, cerium oxide, talc, hydrotalcite, calcium titanate, strontium titanate, Acrylic acid containing inorganic fine particles such as metal titanate such as barium titanate, nitrides such as titanium nitride and silicon nitride, carbides such as titanium carbide and silicon carbide, and acrylic acid and its derivatives as main components And negatively charged organic fine particles such as methacrylic acid resins, methacrylic acid resins mainly composed of methacrylic acid and derivatives thereof, tetrafluoroethylene resins, trifluoroethylene resins, polyvinyl chloride, polyethylene, polyacrylonitrile, etc. It is done.

  Among the inorganic fine particles, silica, titania, and alumina are preferable, and those treated with a silane coupling agent, silicon oil, or the like are more preferable. As the organic fine particles, acrylic acid resins such as polymethyl acrylate and methacrylic acid resins such as polymethyl methacrylate are preferable, and polymethyl methacrylate is particularly preferable.

  The positively charged externally added fine particles include, for example, tricalcium phosphate, calcium dihydrogen phosphate, calcium monohydrogen phosphate, calcium phosphate compounds such as substituted calcium phosphate in which a part of phosphate ion is replaced by an anion, and Examples thereof include those whose surfaces have been subjected to a hydrophobic treatment with fatty acids and the like, surface-treated silica such as aminosilane-treated silica, and alumina.

  The externally added fine particles preferably have an average particle size of preferably 0.001 μm or more, more preferably 0.005 μm or more, preferably 0.1 μm or less, more preferably 0.05 μm or less. Further, a plurality of externally added fine particles having different materials and different average particle diameters can be blended. As the average particle diameter of the externally added fine particles, a method of measuring from an image obtained by an electron microscope, or a value converted as a particle diameter when the particle is assumed to be spherical from the value of the specific surface area measured by the BET method can be used.

  In the present invention, the method of blending and adhering the external fine particles to the surface of the toner particles is not limited, and a mixer generally used for toner production can be used. For example, a Henschel mixer, a V-type blender, a ready It is made by stirring and mixing uniformly with a mixer such as a Gemixer.

  The 50% circularity of the heat fixing toner of the present invention thus obtained is not particularly limited, but is preferably 0.92 or more, more preferably 0.94 or more, preferably 0.99 or less, more preferably It is desirable that it is 0.98 or less, more preferably 0.96 or less. If the circularity is less than the above range, the transfer efficiency may be poor and the dot reproducibility may be deteriorated. If the circularity exceeds the above range, the untransferred toner remaining on the photoreceptor is not completely scraped off by the blade and causes an image defect. There is a case.

  The volume median diameter of the heat fixing toner of the present invention is preferably from 3 to 15 μm, particularly preferably from 4 to 8 μm.

  The chargeability of the heat fixing toner of the present invention is not limited, but a negatively chargeable developer is desirable, and the charge amount at 23 ° C. and 50% relative humidity is preferably −10 μC / g or less, more preferably Is −20 μC / g or less, preferably −90 μC / g or more, more preferably −70 μC / g or more. When the heat fixing toner of the present invention has a charge amount in the above range, it is preferable because the image quality is high with less fog. The charge amount of the toner can be adjusted by the resin as the main component of the developer, the charge control agent added as necessary, the selection and blending ratio of the externally added fine particles, the blending method or the adhesion method. It is effective to select the externally added fine particles and optimize the adhesion amount. In the present invention, the toner charge amount is measured by first weighing 19.2 g of a non-coated ferrite carrier (P100 manufactured by Powdertech) and 0.8 g of particles to be measured, and stirring for 5 minutes with a reciprocating shaker (stir strength 500 rpm). ) And then measured with a blow-off measuring device (manufactured by Toshiba Chemical).

  The heat fixing toner of the present invention can be used for any of black toner, color toner, and full color toner, but when used as a color toner or full color toner, the effects of the present invention can be exhibited more remarkably.

  The heat fixing toner of the present invention may be used in any form of a two-component developer or a non-magnetic one-component developer. When used as a two-component developer, known carriers such as magnetic substances such as iron powder, magnetite powder, and ferrite powder, or mono or magnetic carriers with their surfaces coated with a resin coating can be used as the carrier. As the coating resin of the resin coating carrier, generally known styrene resin, acrylic resin, styrene acrylic copolymer resin, silicone resin, modified silicone resin, fluororesin, or a mixture thereof can be used.

  Hereinafter, the image forming apparatus and the image forming method of the present invention will be described by taking non-magnetic one-component development as an example. The image forming apparatus used in the present invention includes a member selected from a toner supply roller, a layer thickness regulating member, a developing roller, a toner stirring member, and the like, and the heat fixing toner of the present invention. Also, the image forming apparatus of the present invention is preferably a cartridge type.

  When performing non-magnetic one-component development, the layer thickness of the developer on the developing roller is usually regulated by a layer thickness regulating member, and the developer and the layer thickness regulating member at this time are brought into contact friction so that the developer Charge. Note that the layer thickness regulating member may be a member that presses the developing roller or a non-contact member, but the member that presses the developing roller efficiently charges the developer. This is preferable. In addition, the developing roller of the present invention may be used in a developing system that is not in contact with the photosensitive member or in a developing system that is in contact with the photosensitive member, but the contact system is preferable in terms of increasing the development efficiency.

  As described above, the heat fixing toner of the present invention has excellent low-temperature fixability and high-temperature offset resistance, and is excellent for high-speed printing. In particular, the effects of the present invention are remarkably exhibited in a region where the printing speed is 100 mm / s or more, further 150 mm / s or more, particularly 200 mm / s or more.

  In addition, the image forming apparatus having the heat fixing toner of the present invention can prevent the toner from dropping or leaking from the developing device such as the developing roller even in the long-time development processing, and can suppress contamination in the image forming apparatus. A high-quality image without density unevenness can be obtained.

  Hereinafter, the present invention will be described more specifically with reference to examples and the like. However, the present invention is not limited to the following examples unless it exceeds the gist. In the following examples, “parts” means “parts by weight” and “%” means “mass%”.

<Preparation of Wax (A) Dispersion AW1>
A dispersion of wax (A) contained in the core particles was prepared as follows.
Demineralized water: 224 parts,
Pentaerythritol tetrastearate (Unistar H476, manufactured by NOF Corporation): 100 parts,
Sodium dodecylbenzenesulfonate (Neogen S-20A, Daiichi Kogyo Seiyaku Co., Ltd., active ingredient 20%): 9.2 parts are mixed, emulsified by applying high-pressure shear at 90 ° C. using a homogenizer, and ester system A wax dispersion was obtained. The volume average particle diameter of the dispersed wax by the following measuring method was 220 nm. The obtained dispersion is designated as “wax (A) dispersion AW1”.

<Preparation of Silicone Wax Dispersion SW1>
A dispersion of silicon wax contained in the shell was prepared as follows.
Demineralized water: 224 parts,
Silicon wax (in the general formula (1), R ¹ is a propyl group, R ² is an alkyl group having 18 to 60 carbon atoms, k + m + n is 75, and m / (k + m + n) is 0.03 to 0.08. N / (k + m + n) is 0.30 to 0.58, R ⁴ is an alkyl group having 18 to 60 carbon atoms, the endothermic maximum peak is 72 ° C., and the endothermic peak area of 50 ° C. or less is the total endothermic. Alkyl-modified silicone wax which is 20% of the peak area): 100 parts sodium dodecylbenzenesulfonate (Neogen S-20A, Daiichi Kogyo Seiyaku Co., Ltd., active ingredient 20%): 9.2 parts are mixed, and a homogenizer is used. The mixture was emulsified by applying high-pressure shearing at 90 ° C. to obtain a silicone wax dispersion. The volume average particle diameter of the dispersed silicon wax according to the following measuring method was 265 nm. The obtained dispersion is designated as “silicone wax dispersion SW1”.

<Method for producing the above silicon wax>
The alkyl-modified silicone wax used for the preparation of the silicone wax dispersion SW1 was synthesized as follows. That is, 32 g of hexamethyldisiloxane, 434 g of tetramethylcyclotetrasiloxane, 534 g of octamethylcyclotetrasiloxane, and 30 mL of sulfuric acid were charged into a 2 L flask and stirred at 25 ° C. for 8 hours. This was neutralized and then filtered to obtain a raw material hydromethylpolysiloxane. Next, 21 g of the previously obtained hydromethylpolysiloxane, 79 g of an alpha olefin mixture (alpha olefin mixture having 18 to 60 carbon atoms), 100 g of xylene, and a platinum catalyst were added to a four-necked flask, and nitrogen was added. It stirred at 100 degreeC under the airflow for 6 hours. When 80% of the hydrosilyl group was consumed, propylene was bubbled through the system for reaction. After the reaction, xylene was removed under reduced pressure to obtain the above alkyl-modified silicon wax.

<Preparation of polymer primary particle P1 dispersion>
In a reactor equipped with a stirrer (three blades), a heating / cooling device, a concentrating device, and each raw material / auxiliary charging device, 42 parts of the wax (A) dispersion AW1 described above as a solid content and 340 parts of demineralized water Was heated to 70 ° C. under a nitrogen stream, and 3.2 parts of an 8% aqueous hydrogen peroxide solution and 3.2 parts of an 8% aqueous ascorbic acid solution were added. Thereafter, a mixture of the following polymerizable monomers and the following aqueous emulsifier solution was added over 5 hours from the start of polymerization, and at the same time, the following aqueous initiator solution was added over 8 hours from the start of polymerization, and further maintained for 1 hour.

[Polymerizable monomers]
Styrene 76.8 parts butyl acrylate 23.2 parts acrylic acid 1.5 parts bromotrichloromethane 1.0 part hexanediol diacrylate 2.0 parts [emulsifier aqueous solution]
20 parts of 20% neogen S-20A aqueous solution 68 parts demineralized water 68 parts [initiator aqueous solution]
25% 8% aqueous hydrogen peroxide solution 25 parts 8% aqueous ascorbic acid solution

  After completion of the polymerization reaction, the mixture was cooled to obtain a milky white polymer primary particle P1 dispersion. The concentration of the wax (A) in the polymer primary particles is 12%. The polymer had a weight average molecular weight of 52,000 in THF-soluble matter.

<Preparation of resin fine particle P2 dispersion>
In a reactor equipped with a stirrer (three blades), a heating / cooling device, a concentrating device, and each raw material / auxiliary charging device, 16.3 parts of the above-described silicon-based wax dispersion SW1 as a solid content, demineralized water 319 Then, the temperature was raised to 70 ° C. under a nitrogen stream, and 3.2 parts of an 8% aqueous hydrogen peroxide solution and 3.2 parts of an 8% ascorbic acid aqueous solution were added.

  Thereafter, a mixture of the following polymerizable monomers and the following emulsifier aqueous solution was added over 5 hours from the start of polymerization, and at the same time, the following initiator aqueous solution was added over 6 hours from the start of polymerization, and further maintained for 1 hour.

[Polymerizable monomers]
Styrene 79 parts butyl acrylate 21 parts acrylic acid 1.5 parts bromotrichloromethane 0.5 part [emulsifier aqueous solution]
20% Neogen S-20A aqueous solution 1.5 parts Demineralized water 66.2 parts [Initiator aqueous solution]
19 parts of 8% aqueous hydrogen peroxide solution 19 parts of 8% aqueous ascorbic acid solution

  After completion of the polymerization reaction, the mixture was cooled to obtain a milky white resin fine particle P2 dispersion. The concentration of the silicon wax in the fine particles is 4.0%. This resin had a weight-average molecular weight of 55,000 in THF-soluble matter.

<Preparation of resin fine particle P3 dispersion>
In the preparation of the resin fine particle P2 dispersion, a resin fine particle P3 dispersion was prepared in the same manner as the preparation of the resin fine particle P2 dispersion except that the amount of the silicon-based wax dispersion SW1 was halved. The concentration of silicon wax in the particles is 2.0%. This resin had a weight-average molecular weight of 55,000 in THF-soluble matter.

<Preparation of resin fine particle P4 dispersion>
In the preparation of the resin fine particle P2 dispersion, a resin fine particle P4 dispersion was prepared in the same manner as the preparation of the resin fine particle P2 dispersion except that the preparation of the silicon wax dispersion SW1 was eliminated. The concentration of silicon wax in the particles is 0%. This resin had a weight-average molecular weight of 57000 in THF-soluble matter.

<Preparation of resin fine particle P5 dispersion>
In the preparation of the resin fine particle P2 dispersion, the resin fine particle P5 dispersion is prepared in the same manner as the preparation of the resin fine particle P2 dispersion except that the wax (A) dispersion AW1 is used instead of the silicon-based wax dispersion SW1. did. The concentration of wax (A) in the particles is 4.0%. The resin had a weight-average molecular weight of 51000 in THF-soluble matter.

<Colorant fine particle dispersion>
Pigment Blue 15: 3 aqueous dispersion (EP-700
Blue GA, manufactured by Dainichi Seika Co., Ltd., solid content 35%) was used. The volume average particle diameter measured by the following method was 150 nm.

<Manufacture of heat fixing toner T1>
90 parts of polymer primary particle P1 dispersion (as solid content in dispersion)
Resin fine particle P2 dispersion 10 parts (as solid content in dispersion)
Colorant fine particle dispersion 4.4 parts (as solid content in dispersion)
20 parts of 20% neogen S20 aqueous solution (as solid content in aqueous solution)

  Using each of the above components, toner T1 was produced by the following procedure. Polymer primary particle P1 dispersion and 20% Neogen S20 aqueous solution were charged into a reactor (volume 10 L, anchor blade with baffle) and mixed uniformly, and then the colorant fine particle dispersion was added and mixed uniformly. While stirring the obtained mixed dispersion, an aqueous aluminum sulfate solution was added dropwise (0.4 parts as a solid content). Thereafter, while stirring, the temperature was raised to 52 ° C. over 1 hour and held for 1 hour.

  Subsequently, resin fine particle P2 dispersion liquid and aluminum sulfate aqueous solution (0.1 part as solid content) were added in that order, and held for 1 hour. After adding 20% Neogen S20 aqueous solution (8 parts as solid content), the temperature was raised to 98 ° C. over 2 hours and maintained for 2.5 hours. Thereafter, the mixture was cooled, filtered, washed with water, and dried to obtain toner particles.

  To 100 parts of the toner particles, 2 parts of silica 1 as an external additive fine particle, 0.5 part of silica 2 and 0.1 part of titania 1 are mixed with a mixer, and a heat fixing toner T1 (volume median diameter) is mixed. 7.2 μm, 50% circularity 0.94) was produced.

[Externally added fine particles]
Silica 1: H05TD manufactured by Wacker
(Dimethylpolysiloxane treatment, average primary particle size of about 30 nm, density of 2.4 g / cm ³ )
Silica 2: H30TD manufactured by Wacker
(Dimethylpolysiloxane treatment, average primary particle size of about 7 nm, density of 2.4 g / cm ³ )
Titania 1: SMT-150ID manufactured by Teika
(Alkylsilane treatment, average primary particle size of about 15 nm, density of 4.2 g / cm ³ )

<Manufacture of toner T2 for heat fixing>
A heat fixing toner T2 (volume median diameter 7.2 μm, 50% circularity 0.95) was produced in the same manner as the heat fixing toner T1, except that the composition of each component was changed as follows.
85 parts of polymer primary particle P1 dispersion (as solid content in dispersion)
Resin fine particle P2 dispersion 15 parts (as solid content in dispersion)
Colorant fine particle dispersion 4.4 parts (as solid content in dispersion)
20 parts of 20% neogen S20 aqueous solution (as solid content in aqueous solution)

<Manufacture of heat fixing toner T3>
A heat fixing toner T3 (volume median diameter 7.2 μm, 50% circularity 0.94) was produced in the same manner as the heat fixing toner T1, except that the composition of each component was changed as follows.
95 parts of polymer primary particle P1 dispersion (as solid content in dispersion)
Resin fine particle P3 dispersion 5 parts (as solid content in dispersion)
Colorant fine particle dispersion 4.4 parts (as solid content in dispersion)
20 parts of 20% neogen S20 aqueous solution (as solid content in aqueous solution)

<Manufacture of toner T4 for heat fixing>
Heat fixing toner T4 (volume median diameter 7.2 μm, 50% circularity) in the same manner as heat fixing toner T1, except that the composition of each component is changed as follows and only the core particles are produced and no shell is formed. 0.95) was produced.
100 parts of polymer primary particle P1 dispersion (as solid content in dispersion)
Colorant fine particle dispersion 4.4 parts (as solid content in dispersion)
20 parts of 20% neogen S20 aqueous solution (as solid content in aqueous solution)

<Manufacture of heat fixing toner T5>
A heat fixing toner T5 (volume median diameter 7.2 μm, 50% circularity 0.94) was produced in the same manner as the heat fixing toner T1, except that the composition of each component was changed as follows.
95 parts of polymer primary particle P1 dispersion (as solid content in dispersion)
Resin fine particle P4 dispersion 5 parts (as solid content in dispersion)
Colorant fine particle dispersion 4.4 parts (as solid content in dispersion)
20 parts of 20% neogen S20 aqueous solution (as solid content in aqueous solution)

<Manufacture of toner T6 for heat fixing>
A heat fixing toner T6 (volume median diameter 7.2 μm, 50% circularity 0.95) was produced in the same manner as the heat fixing toner T1, except that the composition of each component was changed as follows.
90 parts of polymer primary particle P1 dispersion (as solid content in dispersion)
Resin fine particle P5 dispersion 10 parts (as solid content in dispersion)
Colorant fine particle dispersion 4.4 parts (as solid content in dispersion)
20 parts of 20% neogen S20 aqueous solution (as solid content in aqueous solution)

<Manufacture of heat fixing toner T7>
The heat fixing toner T7 (volume median diameter 7.2 μm, 50 μm) was prepared in the same manner as the heat fixing toner T1, except that each component composition was changed as follows and toner particles were produced using the resin fine particle P3 dispersion. % Circularity 0.97) was produced.
100 parts of resin fine particle P3 dispersion (as solid content in dispersion)
Colorant fine particle dispersion 4.4 parts (as solid content in dispersion)
20 parts of 20% neogen S20 aqueous solution (as solid content in aqueous solution)

Table 1 summarizes the constitution of the heat fixing toner. In Table 1, the types of wax, shell ratio, a × b, etc. are as follows.
Wax (A) in AW1: Silicon wax in pentaerythritol tetrastearate SW1: Alkyl-modified silicon wax shell ratio = weight of resin fine particles for shell / (weight of polymer fine particles for core fine particles + resin fine particles for shell weight)
Therefore, a × b indicates “weight ratio (%) of silicon-based wax in the shell to the whole toner particles”.

  In the present invention, the “maximum endothermic peak temperature” and “ratio of the endothermic peak area of 50 ° C. or less to the total endothermic peak area”, the volume average particle diameter of dispersed particles, the particle size distribution and volume average particle diameter of toner particles in the present invention. The polymer weight average molecular weight, glass transition point (Tg), 50% circularity, fixing temperature width, and anti-blocking property are evaluated by the following methods, respectively, and are defined thereby.

<Endothermic maximum peak temperature>
Using a differential scanning calorimeter DSC-6200 manufactured by Seiko Denshi Kogyo Co., Ltd., a temperature that gives the maximum endothermic peak measured in the second heating step by heating 5 mg of the sample at a heating rate of 10 ° C./min is defined. To do.

<Ratio of the endothermic peak area of 50 ° C. or less to the total endothermic peak area>
The endothermic peak area is defined as the area surrounded by the endothermic peak and the base line of the endothermic curve obtained in the same manner as in the endothermic maximum peak temperature measurement. Further, the endothermic peak area of 50 ° C. or lower is defined as the area of the endothermic peak area divided into 50 ° C. or lower. It is the ratio to the total endothermic peak area.

<Volume average particle diameter of dispersed particles>
In the present invention, the volume average particle size of the silicon wax or wax (A) in the wax dispersion, the polymer primary particles in the dispersed state, the resin fine particles in the dispersed state, and the colorant in the colorant dispersion is Nikkiso Co., Ltd. Measurement was performed with a microtrack UPA (ultraparticulate analyzer). Moreover, numerical values such as these volume average particle diameters in the present invention are defined as those measured by this apparatus.

<Volume median diameter of heat fixing toner>
In the present invention, a multisizer III (aperture diameter 100 μm, hereinafter abbreviated as multisizer) manufactured by Beckman Coulter, Inc. is used, and the dispersion medium is dispersed to a dispersoid concentration of 0.03% using Isoton II. It was measured.

<Weight average molecular weight (Mw)>
In the present invention, the weight average molecular weight (Mw) of the binder resin in the dispersion was measured by gel permeation chromatography (hereinafter abbreviated as “GPC”).
Apparatus: GPC apparatus manufactured by Tosoh Corporation HLC-8020
Column: Polymer Laboratories PL-gel Mixed-B 10μ
Solvent: Tetrahydrofuran (THF)
Sample concentration: 0.1% by mass
Calibration curve creation: Prepared from the following 13 types of standard polystyrene (manufactured by Tosoh Corporation).
Std1:
8.42 × 10 ⁶ , 1.09 × 10 ⁶ , 3.55 × 10 ⁵ , 9.64 × 10 ⁴ , 1.67 × 10 ⁴ , 5.97 × 10 ³ , 1.05 × 10 ³
Std2:
3.84 × 10 ⁶ , 7.06 × 10 ⁵ , 1.90 × 10 ⁵ , 3.79 × 10 ⁴ , 9.10 × 10 ³ , 2.63 × 10 ³
Measurement: At a temperature of 40 ° C., THF was allowed to flow at 1.0 mL / min, and 100 μL of a sample prepared in the following manner was injected into this.

Sample preparation method (1) The water in the dispersion is sufficiently dried by an appropriate method to obtain a solid content.
(2) Using an electronic balance capable of measuring up to 3 digits after the decimal point, accurately measure 1 g of solid content, dissolve in 100 g of THF at room temperature (25 ° C.), and gently stir with a stirrer for 15 minutes.
(3) The obtained solution is filtered with a syringe equipped with a chroma disk 13P manufactured by GL Sciences, and the filtrate is used as a sample.

<50% circularity of heat fixing toner>
The dispersoid is dispersed in a dispersion medium (Isoton II: manufactured by Beckman Coulter, Inc.) so as to be 5720-7140 particles / μL, and the heat fixing toner is used using a flow type particle image analyzer (“FPIA2100” manufactured by Sysmex Corporation). The value corresponding to the cumulative particle size value when the circularity value obtained by the following formula is 50%, measured in the HPF mode under the conditions of an HPF analysis amount of 0.35 μL and an HPF detection amount of 2000 to 2500. Was 50% circularity.
Circularity = circumference of the circle with the same area as the projected particle area / circumference of the particle image method

<Fixing temperature range>
A commercially available full-color laser printer using a toner T1 to T7 for heat fixing (a photoconductor is an organic photoconductor, a non-magnetic one-component development system in which the photoconductor and a developing roller are in contact with each other, and an intermediate transfer system) .) Was modified and printed on paper without fixing. For printing, a rectangular solid image having an area of 100 cm ² (5 cm × 20 cm) is printed near the upper end of A4 size plain paper (FC Dream manufactured by Kishu Paper Co., Ltd .: weight of about 80 g / m ² ), and toner adheres to each unfixed image The amount was set to ^two levels of 0.5 ± 0.02 mg / cm ² and 1.5 ± 0.03 mg / cm ² .

  A fixing device of a full color laser printer DocuPrint C3530 manufactured by Fuji Xerox Co., Ltd., which was modified so that the driving speed and fixing temperature can be changed, was used as an evaluation fixing device and evaluated at a fixing speed of 200 mm / s (nip time 45 ms).

  The fixing performance at each temperature was confirmed by inserting the unfixed image with the fixing machine reaching a predetermined speed and temperature. Fixes the temperature in the range of 130 to 190 ° C in 5 ° C increments, and does not cause cold offset. It was confirmed. The results are shown in Table 2.

<Blocking resistance>
A constant load was applied to the toner and left in an environment of 50 ° C. for 5 hours, and then the presence or absence of aggregation was confirmed to determine whether the blocking property was good or bad.
Aggregation is not confirmed and good: ○
Aggregation is confirmed and defective, impractical: ×

As can be seen from Table 2, each of the heat fixing toners T1 to T3 of the present invention has a cold offset from a low temperature regardless of whether the toner adhesion amount is 0.5 mg / cm ² or 1.5 mg / cm ^2. Fixes without causing any problems and has excellent low-temperature fixability. Further, no hot offset was observed up to 190 ° C., and the high temperature offset resistance was excellent.

On the other hand, the core particles are not formed with a shell (T4), the shell is formed, but the shell does not contain wax (T5), and the shell contains ester wax. All of the toners (T6) had no fixing temperature range when the toner adhesion amount was 1.5 mg / cm ² , and were inferior in low-temperature fixability and high-temperature offset resistance. In addition, the core particle itself containing silicon wax (T7) does not have a fixing temperature range regardless of the toner adhesion amount, has a core particle and a shell, and has a specific structure in the shell. It has been found that the inclusion of silicon wax is effective for fixing properties.

  Further, all of the heat fixing toners T1 to T3 of the present invention were excellent in blocking resistance. On the other hand, the heat fixing toners T4 and T6 were inferior in blocking resistance and did not reach a practical level.

The toner for heat fixing of the present invention is excellent in low temperature fixing property, high temperature offset resistance, blocking resistance, etc., and can obtain high quality images at high speed, so it is widely used in electrophotographic copying machines, printers, etc. It is what is done.

Claims (14)

Obtained when core resin containing binder resin (a) and colorant has binder resin (b) and the following repeating units (p) and (q), and the endothermic characteristics are measured with a differential scanning calorimeter. The endothermic peak area of 50 ° C. or less is 45% or less of the total endothermic peak area in the endothermic property obtained when the endothermic maximum peak temperature is in the range of 30 to 120 ° C. and the endothermic property is measured with a differential scanning calorimeter. A heat fixing toner comprising a shell containing a silicon wax.

[Wherein R ³ represents a linear or branched alkyl group having 1 to 6 carbon atoms which may be different from each other or an aryl group having 6 to 12 carbon atoms, and R ⁴ is a linear chain having 6 to 100 carbon atoms. Alternatively, it represents a branched alkyl group. ] 2. The heat fixing toner according to claim 1, wherein the silicon wax is one in which R ³ is a methyl group in the repeating units (p) and (q).   3. The heat fixing toner according to claim 1, wherein the silicon wax satisfies a molar ratio of the repeating unit (p) to the repeating units (p) and (q) of 1/10 to 4/5. . A core particle containing a binder resin (a) and a colorant is coated with a shell containing a binder resin (b) and a silicon wax represented by the general formula (1). toner.

[Wherein, R ¹ represents an alkyl group having 2 to 10 carbon atoms, and R ² represents an alkyl group having 11 or more carbon atoms. k + m + n is an integer of 10 to 150, and satisfies 0 ≦ m / (k + m + n) ≦ 0.2 and 0.1 ≦ n / (k + m + n) ≦ 1. ]   The thermal fixing toner according to claim 4, wherein the silicon wax further satisfies 0.2 ≦ n / (k + m + n) ≦ 0.8 in the general formula (1).   6. The thermal fixing toner according to claim 4, wherein the silicon-based wax further satisfies 0.01 ≦ m / (k + m + n) ≦ 0.17 in the general formula (1).   The heat fixing toner according to any one of claims 1 to 6, wherein the silicon wax in the shell is dispersed in the binder resin (b) in a volume average particle diameter of 100 nm to 400 nm.   The coating of the shell on the core particles is performed by causing a dispersion of resin fine particles containing the binder resin (b) and silicon wax to act on the dispersion of core particles. The heat fixing toner according to claim 1.   9. The heat fixing toner according to claim 8, wherein the resin fine particles are fine particles containing a binder resin (b) obtained by emulsion polymerization using silicon wax as a seed.   10. The heat fixing toner according to claim 1, wherein the silicon wax in the shell is contained in an amount of 0.01 to 2% by mass with respect to the whole toner particles.   11. The heat fixing toner according to claim 1, wherein the core particle is obtained by an emulsion polymerization aggregation method or a suspension polymerization method.   12. The heat fixing toner according to claim 1, wherein the core particles further contain a hydrocarbon wax or an ester wax.   The heat fixing toner according to any one of claims 1 to 12, wherein the 50% circularity is in a range of 0.92 to 0.99. An image forming apparatus using the heat fixing toner according to any one of claims 1 to 13.