JP6219703B2 - toner - Google Patents

Description

  The present invention relates to a toner used for developing a latent image formed in an electrostatic image development method, an electrostatic recording method, an electrostatic printing method, or the like.

  In recent years, there has been a strong demand for resource saving and energy saving along with the promotion of miniaturization, high speed and high image quality of electrophotographic apparatuses.

  In order to meet this demand, for example, Patent Document 1 discloses a toner manufacturing method including a step of melt-kneading at least a binder resin and a release agent. The release agent specifies an α-olefin having a specific carbon number. Disclosed is a method for producing a toner containing an α-olefin polymer obtained by polymerizing a monomer containing a certain amount, and melt kneading with an open roll kneader, and reducing the amount of toner remaining in the toner cartridge. It is shown that a toner that can be obtained is obtained.

  Patent Document 2 discloses a toner containing at least a binder resin, a colorant, and an α-olefin, and the α-olefin has (1) a peak temperature of a maximum endothermic peak in a differential scanning calorimeter (DSC) of 55. The toner is characterized in that it is in the range of ~ 99 ° C, (2) the average carbon number is in the range of 20-50, and (3) the penetration at 25 ° C is in the range of 1-50. It is disclosed that an image that is uniformly dispersed in a toner, has good storage stability, has excellent low-temperature fixability, and satisfies high definition can be stably formed.

Further, Patent Document 3 discloses specific physical properties as a release agent in a color toner comprising at least a binder resin, a colorant, a release agent, and a base color particle mainly composed of a charge control agent and an external additive. A 1-olefin polymer wax comprising units derived from a 1-olefin represented by R′CH═CH ₂ , wherein R ′ is alkyl having 1 to 28 carbon atoms. The characteristic color toner for electrophotography has good and stable developability even with long-term agitation, and has good fixability, glossiness, transparency, separation without applying fixing oil to the fixing device. It is disclosed that it has formality.

JP2013-92626A JP 2006-154624 A JP 2000-352838 A

  However, with increasing speed and miniaturization, if more mechanical or thermal stress is applied, problems related to durability reduction have occurred, improving low temperature fixability to meet energy saving requirements, It is not sufficient to improve the durability to meet the demand for higher speed and smaller size.

  The present invention relates to a toner that has excellent low-temperature fixability and high-temperature offset resistance, and suppresses the generation of streaks under low temperature and low humidity and fogging under high temperature and high humidity.

The present invention
A toner comprising a binder resin, a colorant, a release agent, and a charge control agent,
The binder resin contains a resin H and a resin L having different softening points;
The resin H is a non-linear polyester having a softening point of 140 ° C. or higher and 170 ° C. or lower,
The resin L is a linear polyester having a softening point of 85 ° C. or more and 95 ° C. or less and a peak top molecular weight of 6000 or more and 8000 or less,
The mass ratio of the resin H to the resin L (resin H / resin L) is 50/50 to 80/20,
The mold release agent contains an α-olefin polymer obtained by polymerizing a monomer containing 95 mol% or more of an α-olefin having 26 to 28 carbon atoms;
The present invention relates to a toner in which the content of the α-olefin polymer is from 0.5 parts by mass to 10 parts by mass with respect to 100 parts by mass of the binder resin.

  The toner of the present invention is excellent in low-temperature fixability and high-temperature offset resistance, and has an excellent effect that generation of streaks under low temperature and low humidity and generation of fog under high temperature and high humidity are suppressed.

  In the toner of the present invention, the binder resin is a non-linear polyester resin H having a softening point of 140 ° C. or more and 170 ° C. or less, a softening point of 85 ° C. or more and 95 ° C. or less, and a peak top molecular weight of 6000 or more and 8000 or less. The resin L, which is a linear polyester, is contained in a mass ratio of 50/50 to 80/20 (resin H / resin L), and 95 α-olefin having 26 to 28 carbon atoms is used as a release agent. The α-olefin polymer obtained by polymerizing the monomer containing at least mol% contains 0.5 parts by mass or more and 10 parts by mass or less with respect to 100 parts by mass of the binder resin, and has low temperature fixability and high temperature offset resistance. And the occurrence of streaks under low temperature and low humidity and fogging under high temperature and high humidity are suppressed.

The reason for such an effect is not clear, but is considered as follows.
A resin with a high softening point improves high-temperature offset resistance and increases the dispersibility of the release agent by taking an appropriate share during melt-kneading, but is disadvantageous for low-temperature fixability. On the other hand, the low softening point resin improves the low-temperature fixability, but lowers the kneading viscosity and lowers the mixing property with the high softening point resin and the release agent. On the other hand, in this invention, the alpha-olefin type polymer obtained by superposing | polymerizing the alpha olefin of specific carbon number is contained as a mold release agent. Since the α-olefin polymer has no polar group and high side chain crystallinity, it has a low melting point and high hardness compared to other release agents, but is difficult to disperse in the binder resin. However, since this side chain has a comb structure with a specific number of carbon atoms, the mixing property is improved rather than a linear low softening point resin in a specific molecular weight range. Since the high softening point resin captures and mixes the mixture of the low softening point resin and the α-olefin polymer having improved mixing properties, the mixing property between the three components is further improved. As a result, exposure of the low softening point resin and release agent to the toner surface is suppressed, and the durability of the toner is improved, thereby suppressing the occurrence of streaks on the developing roller even when printing at low temperature and low humidity. It is considered to be done.

  In addition, since the α-olefin polymer is a structure having an extremely uniform side chain length obtained by polymerizing a monomer containing an α-olefin having 26 to 28 carbon atoms in an amount of 95 mol% or more, at the time of melt kneading The shear is applied evenly between the resins to keep the viscosity uniform, and the colorant and the charge control agent are uniformly dispersed in the toner together with the release agent. As a result, the variation in charging characteristics among the toner particles is reduced, so that the charge amount of the toner particles is improved and the toner is excellent in suppression of fog even under severe conditions such as high temperature and high humidity. .

  The toner of the present invention contains two kinds of resins having different softening points, a resin having a high softening point (resin H) and a resin having a low softening point (resin L) as binder resins.

  The softening point of the resin H is 140 ° C. or higher from the viewpoint of improving the high temperature offset resistance of the toner and suppressing the generation of streaks under low temperature and low humidity and fogging under high temperature and high humidity. Is 145 ° C. or higher, more preferably 150 ° C. or higher. Further, from the viewpoint of improving the low temperature fixability of the toner, it is 170 ° C. or lower, preferably 160 ° C. or lower, more preferably 155 ° C. or lower.

  Resin H is a non-linear material from the viewpoint of improving the high temperature offset resistance of the toner, from the viewpoint of increasing the softening point of the resin, and from suppressing the generation of streaks under low temperature and low humidity and fogging under high temperature and high humidity. Polyester. Non-linear polyester is a polyvalent monomer component that can act as a crosslinking point, that is, the content of a trihydric or higher polyhydric alcohol and a trivalent or higher polyvalent carboxylic acid component is an alcohol component and a carboxylic acid component. The total amount is 1 mol% or more. The content of the trihydric or higher polyhydric alcohol and the trihydric or higher polycarboxylic acid component is preferably 3 mol% or more, more preferably 5 mol% or more, in the total amount of the alcohol component and the carboxylic acid component. Further, from the viewpoint of improving the low-temperature fixability of the toner, it is preferably 25 mol% or less, more preferably 20 mol% or less.

  The softening point of the resin L is 85 ° C. or more from the viewpoint of improving the high temperature offset resistance of the toner and suppressing the generation of streaks under low temperature and low humidity and fogging under high temperature and high humidity. Is above 88 ° C. Further, from the viewpoint of improving the low-temperature fixability of the toner and suppressing the generation of streaks under low temperature and low humidity and fogging under high temperature and high humidity, it is 95 ° C or lower, preferably 93 ° C or lower. Preferably it is 92 degrees C or less.

  Resin L is used for improving the low temperature fixability and high temperature offset resistance of the toner, improving the dispersibility of the release agent, colorant and charge control agent in the binder resin, and streaking under low temperature and low humidity. From the viewpoint of suppressing occurrence of fog and fogging under high temperature and high humidity, it is a linear polyester. The linear polyester is a polyvalent monomer component that can act as a crosslinking point, that is, the content of the trihydric or higher polyhydric alcohol and the trihydric or higher polycarboxylic acid component is the total amount of the alcohol component and the carboxylic acid component. Among them, it means less than 1 mol%, and it is preferable that a trivalent or higher polyvalent monomer is not substantially contained.

  The peak top molecular weight of the resin L is 6000 or more, preferably 6500 or more, from the viewpoint of suppressing the generation of streaks under low temperature and low humidity and the generation of fog under high temperature and high humidity. Further, from the same viewpoint, it is 8000 or less, preferably 7800 or less.

The peak top molecular weight is the molecular weight at the peak top of the highest peak of the GPC profile obtained when the molecular weight of the resin is measured by gel permeation chromatography (GPC), and is measured by the method described in the examples. The
The present invention is characterized in that the softening point of the low-softening point resin L is in a specific range, and at the same time, the peak top molecular weight is maintained in a specific range. In general, the softening point and molecular weight of the resin are correlated, but this is the case when the average molecular weight is considered.If the peak top molecular weight indicating the main component of the molecular weight is used as an index, the softening point and the molecular weight of the resin It can be adjusted independently depending on the type and composition ratio of the component and the carboxylic acid component. According to the present invention, the durability of the toner is controlled by the peak top molecular weight rather than the average molecular weight, and the peak top molecular weight is within a specific range together with the softening point. It is possible to obtain a toner that suppresses the generation of streaks below and fogging under high temperature and high humidity.

  The polyester is obtained by polycondensation of an alcohol component and a carboxylic acid component.

  Examples of the divalent alcohol include diols having 2 to 20 carbon atoms, preferably 2 to 15 carbon atoms, and formula (I):

(In the formula, RO and OR are oxyalkylene groups, R is an ethylene and / or propylene group, x and y are the average number of moles of alkylene oxide added, each being a positive number, The average value of the sum is preferably 1 or more, more preferably 1.5 or more, and is preferably 16 or less, more preferably 8 or less, and further preferably 4 or less.
An alkylene oxide adduct of bisphenol A represented by: Specific examples of the divalent alcohol having 2 to 20 carbon atoms include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, and bisphenol. A, hydrogenated bisphenol A and the like.

  As the alcohol component, an alkylene oxide adduct of bisphenol A represented by the formula (I) is preferable from the viewpoint of suppressing generation of streaks under low temperature and low humidity and generation of fog under high temperature and high humidity. The content of the alkylene oxide adduct of bisphenol A represented by the formula (I) is preferably 50 mol% or more, more preferably 70 mol% or more, further preferably 90 mol% or more, more preferably in the alcohol component. It is substantially 100 mol%, more preferably 100 mol%.

  Examples of the trihydric or higher alcohol include trihydric or higher polyhydric alcohols having 3 to 20 carbon atoms, preferably 3 to 10 carbon atoms. Specific examples include sorbitol, 1,4-sorbitan, pentaerythritol, glycerol, trimethylolpropane, and the like.

  Examples of the divalent carboxylic acid compound include, for example, dicarboxylic acids having 3 to 30 carbon atoms, preferably 3 to 20 carbon atoms, more preferably 3 to 10 carbon atoms, and acid anhydrides thereof, carbon number 1 Derivatives such as alkyl esters of 3 or less are mentioned. Specific examples include aromatic dicarboxylic acid compounds and aliphatic dicarboxylic acid compounds. Examples of the aromatic dicarboxylic acid compound include phthalic acid, isophthalic acid, and terephthalic acid. Examples of the aliphatic dicarboxylic acid compound include fumaric acid, maleic acid, succinic acid, glutaric acid, adipic acid, sebacic acid, an alkyl group having 1 to 20 carbon atoms or an succinic group substituted with an alkenyl group having 2 to 20 carbon atoms. An acid etc. are mentioned. Specific examples of the succinic acid substituted with an alkyl group having 1 to 20 carbon atoms or an alkenyl group having 2 to 20 carbon atoms include dodecyl succinic acid, octenyl succinic acid, tetrapropenyl succinic acid, and the like.

  Examples of the trivalent or higher carboxylic acid compound include a trivalent or higher polyvalent carboxylic acid having 4 to 30 carbon atoms, preferably 4 to 20 carbon atoms, more preferably 4 to 10 carbon atoms, and the like. Examples thereof include acid anhydrides and derivatives of alkyl esters having 1 to 3 carbon atoms. Specific examples include 1,2,4-benzenetricarboxylic acid (trimellitic acid), 1,2,4,5-benzenetetracarboxylic acid (pyromellitic acid), and the like. Especially, from a reactive viewpoint, trimellitic acid and its acid anhydride are preferable, and trimellitic acid anhydride is more preferable.

  As described above, the carboxylic acid component in the non-linear polyester used for the resin H includes the viewpoint of improving the high-temperature offset resistance of the toner, the viewpoint of increasing the softening point of the resin, and the generation of streaks under low temperature and low humidity. From the viewpoint of suppressing the occurrence of fog under high temperature and high humidity, it is preferable to contain a trivalent or higher carboxylic acid compound, and in particular, trimellitic acid and its acid anhydride are more preferable from the viewpoint of reactivity. Trimellitic anhydride is more preferable. The content of the trivalent or higher carboxylic acid compound is preferably 5 mol% or more, more preferably 10 mol% or more, further preferably 15 mol% or more, more preferably 20 mol% or more in the carboxylic acid component. Further, it is preferably at most 50 mol%, more preferably at most 45 mol%, further preferably at most 40 mol%.

  As the carboxylic acid component other than the trivalent or higher carboxylic acid compound in the non-linear polyester used for the resin H, the aromatic dicarboxylic acid compound and the aliphatic dicarboxylic acid compound can be appropriately used. From the viewpoint of improving the mixability with Resin L and suppressing the generation of streaks under low temperature and low humidity and fog generation under high temperature and high humidity, terephthalic acid, fumaric acid, adipic acid, alkyl having 1 to 20 carbon atoms Preferred are derivatives such as succinic acid substituted with a group or an alkenyl group having 2 to 20 carbon atoms, and their acid anhydrides and alkyl esters having 1 to 3 carbon atoms.

  The carboxylic acid component in the linear polyester used for the resin L preferably contains an aromatic dicarboxylic acid compound from the viewpoint of improving the low-temperature fixability and high-temperature offset resistance of the toner. Among them, from the viewpoint of suppressing the generation of streaks under low temperature and low humidity and the occurrence of fog under high temperature and high humidity, derivatives such as terephthalic acid, their acid anhydrides and alkyl esters having 1 to 3 carbon atoms are included. More preferred. The content of the aromatic dicarboxylic acid compound is preferably 50 mol% or more, more preferably 55 mol% or more, more preferably 60 mol% or more, further preferably 65 mol% or more in the carboxylic acid component, Preferably it is 90 mol% or less, More preferably, it is 85 mol% or less, More preferably, it is 80 mol% or less.

  The linear polyester used for the resin L preferably contains an aliphatic dicarboxylic acid compound in addition to the aromatic dicarboxylic acid compound from the viewpoint of adjusting the softening point and peak top molecular weight of the toner. In the case of containing an aliphatic dicarboxylic acid compound, phthalic acid, adipic acid, an alkyl group having 1 to 20 carbon atoms or from the viewpoint of suppressing generation of streaks under low temperature and low humidity and generation of fog under high temperature and high humidity Derivatives such as succinic acid substituted with an alkenyl group having 2 to 20 carbon atoms, and their anhydrides, alkyl esters having 1 to 3 carbon atoms are preferred, and an alkyl group having 1 to 20 carbon atoms or a carbon number Derivatives such as succinic acid substituted with an alkenyl group having 2 to 20 carbon atoms, acid anhydrides thereof, and alkyl esters having 1 to 3 carbon atoms are more preferable. The content of the aliphatic dicarboxylic acid compound is preferably 8 mol% or more, more preferably 15 mol% or more, further preferably 20 mol% or more, and preferably less than 50 mol%, more preferably in the carboxylic acid component. Preferably it is 45 mol% or less, More preferably, it is 43 mol% or less.

  In addition, a monovalent alcohol may be appropriately contained in the alcohol component, and a monovalent carboxylic acid compound may be appropriately contained in the carboxylic acid component from the viewpoint of adjusting the softening point of the polyester.

  The polycondensation reaction between the alcohol component and the carboxylic acid component may be performed in an inert gas atmosphere at a temperature of 180 ° C. or higher and 250 ° C. or lower as necessary in the presence of an esterification catalyst or a polymerization inhibitor. it can. Examples of the esterification catalyst include tin compounds such as dibutyltin oxide and tin (II) 2-ethylhexanoate, and titanium compounds such as titanium diisopropylate bistriethanolamate. The amount of the esterification catalyst used is preferably 0.01 parts by mass or more, more preferably 0.1 parts by mass or more, and preferably 1.5 parts by mass or less, more preferably 100 parts by mass of the total amount of the alcohol component and the carboxylic acid component. Preferably it is 1.0 mass part or less. Tertiary butyl catechol is preferred as the polymerization inhibitor, and the amount used when the polymerization inhibitor is used is preferably 0.001 part by mass or more, more preferably 0.01 parts by mass with respect to 100 parts by mass of the total amount of the alcohol component and the carboxylic acid component. It is at least 0.5 parts by mass, more preferably at most 0.1 parts by mass.

  In the case of the resin H, the glass transition temperature of the polyester is preferably 55 ° C. or higher, more preferably 60 ° C. or higher, and further preferably 65 ° C. or higher, from the viewpoint of improving the high temperature offset resistance of the toner. Further, from the viewpoint of improving the low-temperature fixability of the toner, it is preferably 80 ° C. or lower, more preferably 75 ° C. or lower, and further preferably 73 ° C. or lower.

  In the case of the resin L, the glass transition temperature of the polyester is preferably 40 ° C. or higher, more preferably 45 ° C. or higher, from the viewpoint of improving the high temperature offset resistance of the toner. Further, from the viewpoint of improving the low-temperature fixability of the toner, it is preferably less than 55 ° C, more preferably 50 ° C or less.

  The glass transition temperature of the polyester can be controlled by the type and composition ratio of the alcohol component and carboxylic acid component.

  The acid value of the polyester is preferably 1 mgKOH / g or more from the viewpoint of improving the charging stability of the toner. Moreover, it is preferably 40 mgKOH / g or less, more preferably 35 mgKOH / g or less.

  The acid value of the polyester can be controlled by adjusting the types and composition ratios of the alcohol component and the carboxylic acid component, the amount of the catalyst, etc., and selecting the reaction conditions such as the reaction temperature, reaction time, and reaction pressure.

  In the present invention, the polyester may be a polyester modified to such an extent that the characteristics are not substantially impaired. Examples of the modified polyester include grafting and blocking with phenol, urethane, epoxy and the like by the methods described in JP-A-11-133668, JP-A-10-239903, JP-A-8-20636, and the like. Polyester.

  Examples of binder resins other than polyester include vinyl resins, epoxy resins, polycarbonates, polyurethanes, and the like.

  The mass ratio between the resin H and the resin L (resin H / resin L) is to improve the low-temperature fixability and high-temperature offset resistance of the toner, to generate streaks at low temperatures and low humidity, and to generate fog at high temperatures and high humidity. From the viewpoint of suppressing the above, it is 50/50 to 80/20, preferably 55/45 to 75/25, more preferably 60/40 to 70/30.

  The total amount of the resin H and the resin L is preferably 90% by mass or more, more preferably 95% by mass or more, further preferably 100% by mass, and further preferably 100% by mass in the binder resin.

  The mold release agent is obtained by polymerizing a monomer containing an α-olefin having 26 to 28 carbon atoms from the viewpoint of suppressing generation of streaks under low temperature and low humidity and generation of fog under high temperature and high humidity. -Contains an olefin polymer.

  The content of the α-olefin having 26 to 28 carbon atoms in the raw material monomer of the α-olefin polymer is from the viewpoint of suppressing generation of streaks under low temperature and low humidity and generation of fog under high temperature and high humidity. It is 95 mol% or more, and 97 mol% or more is preferable.

  As a monomer containing 95 mol% or more of an α-olefin having 26 to 28 carbon atoms, a mixture of α-olefins having 18 or more carbon atoms, for example, “Linearene 26+” (manufactured by Idemitsu Kosan Co., Ltd., mainly having 26 or more carbon atoms). A monomer obtained by extracting a uniform supernatant solution after being dissolved in a distillation and / or hydrocarbon solvent at a temperature of 50 ° C. or lower, preferably 15 to 50 ° C. be able to.

  Examples of the hydrocarbon solvent include aromatic hydrocarbon solvents such as toluene and xylene, alicyclic hydrocarbon solvents such as cyclopentane and cyclohexane, aliphatic hydrocarbon solvents such as pentane and hexane, chloroform, and dichloromethane. Halogenated hydrocarbon solvents such as can be used. These solvents may be used alone or in combination of two or more.

  The α-olefin polymer can be synthesized by the method described in International Publication No. 2007/063885. Specifically, it is obtained by dissolving an α-olefin monomer in an aromatic hydrocarbon solvent such as toluene, adding a metallocene catalyst and hydrogen, and polymerizing at 0 to 180 ° C. under normal pressure to 10 MPa. It is done.

  The melting point of the α-olefin polymer in the present invention is preferably from the viewpoint of improving the high temperature offset resistance of the toner, from the viewpoint of suppressing the generation of streaks under low temperature and low humidity and the generation of fog under high temperature and high humidity. 60 ° C. or higher, more preferably 64 ° C. or higher, more preferably 68 ° C. or higher, more preferably 72 ° C. or higher. Also, from the viewpoint of improving the low-temperature fixability of the toner, From the viewpoint of suppressing the generation of fog under humidity, the temperature is preferably 90 ° C. or lower, more preferably 85 ° C. or lower, and still more preferably 80 ° C. or lower. The melting point of the α-olefin polymer can be determined by the method described in Examples described later.

  The melt viscosity at 100 ° C. of the α-olefin polymer is preferably from the viewpoint of improving the high temperature offset resistance of the toner, from the viewpoint of suppressing the generation of streaks under low temperature and low humidity and the generation of fog under high temperature and high humidity. Is at least 100 mPa · s, more preferably at least 120 mPa · s, even more preferably at least 150 mPa · s, even more preferably at least 180 mPa · s, even more preferably at least 190 mPa · s, and the occurrence of streaks at low temperature and low humidity From the viewpoint of suppressing fogging under high temperature and high humidity, it is preferably 300 mPa · s or less, more preferably 250 mPa · s or less, and further preferably 220 mPa · s or less.

  The content of the α-olefin polymer is selected from the viewpoint of improving the high temperature offset resistance of the toner, from the viewpoint of suppressing the generation of streaks under low temperature and low humidity and the generation of fog under high temperature and high humidity. It is 0.5 parts by mass or more, preferably 1 part by mass or more, more preferably 1.5 parts by mass or more, and further preferably 2 parts by mass or more with respect to parts by mass. Further, from the viewpoint of suppressing the generation of streaks under low temperature and low humidity and fog generation under high temperature and high humidity, it is 10 parts by mass or less, preferably 8 parts by mass or less, with respect to 100 parts by mass of the binder resin. 6 parts by mass or less is more preferable, 5 parts by mass or less is more preferable, and 4 parts by mass or less is more preferable.

  Examples of mold release agents other than α-olefin polymers include polypropylene, polyethylene, polypropylene polyethylene copolymers, hydrocarbon waxes such as microcrystalline wax, paraffin wax, and Fischer-Tropsch wax, and oxides thereof, carnauba wax, Examples include ester waxes such as montan wax, sasol wax and their deoxidized wax, fatty acid amides, fatty acids, higher alcohols, fatty acid metal salts and the like.

  The content of the α-olefin-based polymer in the release agent is preferably 50% by mass or more, more preferably from the viewpoint of suppressing generation of streaks under low temperature and low humidity and generation of fog under high temperature and high humidity. It is 60% by mass or more, more preferably 65% by mass or more, more preferably 80% by mass or more, and further preferably 90% by mass or more.

  As the charge control agent, either a negatively chargeable charge control agent or a positively chargeable charge control agent can be used.

  Examples of the negatively chargeable charge control agent include metal-containing azo dyes, copper phthalocyanine dyes, metal complexes of salicylic acid alkyl derivatives, nitroimidazole derivatives, and benzyl acid boron complexes. Examples of metal-containing azo dyes include “Varifirst Black 3804”, “Bontron S-28”, “Bontron S-31”, “Bontron S-32”, “Bontron S-34”, “Bontron S-36” ( As mentioned above, “Orient Chemical Co., Ltd.”, “T-77”, “Eisenspiron Black TRH” (above, Hodogaya Chemical Co., Ltd.) and the like can be mentioned. Examples of metal complexes of alkyl derivatives of salicylic acid include “Bontron E-81”, “Bontron E-82”, “Bontron E-84”, “Bontron E-85”, “Bontron E-304” (above, Orient Chemistry) Manufactured by Kogyo Co., Ltd.). Examples of the benzyl acid boron complex include “LR-147” (manufactured by Nippon Carlit).

  Examples of the positively chargeable charge control agent include nigrosine dyes, triphenylmethane dyes, quaternary ammonium salt compounds, polyamine resins, and imidazole derivatives. Nigrosine dyes include, for example, “Nigrosine Base EX”, “Oil Black BS”, “Oil Black SO”, “Bontron N-01”, “Bontron N-07”, “Bontron N-09”, “Bontron N-11” (Above, manufactured by Orient Chemical Industry Co., Ltd.). Examples of the triphenylmethane dye include a triphenylmethane dye containing a tertiary amine as a side chain. Examples of quaternary ammonium salt compounds include “Bontron P-51”, “Bontron P-52” (manufactured by Orient Chemical Co., Ltd.), “TP-415” (Hodogaya Chemical Co., Ltd.), cetyltrimethylammonium bromide. , "COPY CHARGE PXVP435", "COPY CHARGE PSY" (manufactured by Clariant). Examples of the polyamine resin include “AFP-B” (manufactured by Orient Chemical Industry Co., Ltd.). Examples of the imidazole derivative include “PLZ-2001”, “PLZ-8001” (manufactured by Shikoku Kasei Co., Ltd.) and the like.

  The content of the charge control agent is preferably 0.2 parts by mass or more, more preferably 0.5 parts by mass or more, and more preferably 5 parts by mass or less with respect to 100 parts by mass of the binder resin from the viewpoint of improving the charging stability of the toner. Is preferable, and 3 parts by mass or less is more preferable.

  As the colorant, all of dyes and pigments used as toner colorants can be used, such as carbon black, phthalocyanine blue, permanent brown FG, brilliant first scarlet, pigment green B, rhodamine-B base, Solvent Red 49, Solvent Red 146, Solvent Blue 35, Quinacridone, Carmine 6B, Isoindoline, Disazo Yellow and the like can be used, and the toner of the present invention may be either black toner or color toner.

  The content of the colorant is preferably 1 part by mass or more and more preferably 2 parts by mass or more from the viewpoint of improving the toner image density with respect to 100 parts by mass of the binder resin. Further, from the viewpoint of improving the productivity of the toner, it is preferably 20 parts by mass or less, more preferably 10 parts by mass or less, and further preferably 5 parts by mass or less.

  The toner of the present invention further contains additives such as magnetic powders, fluidity improvers, conductivity modifiers, reinforcing fillers such as fibrous substances, antioxidants, anti-aging agents, and cleanability improvers as appropriate. It may be.

  The toner of the present invention may be a toner obtained by any conventionally known method such as a melt-kneading method, an emulsion aggregation method, or a polymerization method. However, from the viewpoint of productivity, a pulverized toner by the melt-kneading method is used. preferable. Therefore, the method for producing the toner of the present invention is preferably a method including a step of melt-kneading a toner component containing a binder resin, a release agent and a charge control agent to obtain a melt-kneaded product. A toner component containing additives such as a resin, a release agent, a charge control agent and, if necessary, a colorant is uniformly mixed in a mixer such as a Henschel mixer, then melt-kneaded, cooled, pulverized and classified. To produce a toner.

  Melting and kneading of the toner component can be performed using a known kneader such as a closed kneader, a single or twin screw extruder, and an open roll kneader. From the viewpoint of reducing the temperature at the time of melt-kneading, improving the low-temperature fixability and heat-resistant storage stability of the toner, and releasing agents and charge control agents in the binder resin without repeating kneading or using a dispersion aid. It is preferable to use a biaxial kneader from the viewpoint of efficiently and highly dispersing toner components such as the above.

  The biaxial kneader is a closed type kneader in which two kneading shafts are covered with a barrel, and a type in which the rotation directions of the shafts can rotate in the same direction is preferable. As a commercial product, from the viewpoint of improving the productivity of toner, a twin screw extruder PCM series manufactured by Ikekai Tekko Co., Ltd., which is good at high speed two-axis meshing is preferable.

  Toner components including additives such as binder resin, colorant, charge control agent, and release agent used as necessary are mixed in advance by a mixer such as a Henschel mixer or ball mill, and then supplied to the kneader. Is preferred.

  The melt kneading in the biaxial kneader is performed by adjusting the barrel set temperature (temperature of the inner wall surface of the extruder), the peripheral speed of biaxial shaft rotation, and the raw material supply speed. The barrel set temperature is preferably 80 ° C. or higher, more preferably 90 ° C. or higher, from the viewpoint of improving dispersibility in the binder resin such as a release agent and a charge control agent, and from the viewpoint of improving toner productivity. It is preferably 140 ° C. or lower, more preferably 120 ° C. or lower.

  The peripheral speed of the biaxial shaft rotation is 0.1 m / sec or more, 1 m from the viewpoint of improving the dispersibility in the binder resin such as the release agent and the charge control agent and improving the productivity of the toner. / sec or less is preferable.

The feed rate of the raw material to the biaxial kneader is appropriately adjusted according to the allowable capacity of the kneader to be used, the barrel set temperature and the peripheral speed of the shaft rotation.

  The obtained melt-kneaded product is preferably cooled to such an extent that it can be crushed, and then crushed and classified.

  The pulverization process may be performed in multiple stages. For example, the resin kneaded material may be coarsely pulverized to about 1 to 5 mm and further pulverized to a desired particle size.

  The pulverizer used in the pulverization step is not particularly limited, and examples of the pulverizer suitably used for coarse pulverization include a hammer mill, an atomizer, and a rotplex. Further, examples of the pulverizer suitably used for fine pulverization include a fluidized bed jet mill, a collision plate jet mill, and a rotary mechanical mill. From the viewpoint of pulverization efficiency, it is preferable to use a fluidized bed jet mill and a collision plate jet mill, and more preferably a fluidized bed jet mill.

  Examples of the classifier used in the classification process include a rotor classifier, an airflow classifier, an inertia classifier, and a sieve classifier. In the classification step, the pulverized product that has been removed due to insufficient pulverization may be subjected to the pulverization step again, and the pulverization step and the classification step may be repeated as necessary.

  An external additive may be added to the toner of the present invention from the viewpoint of improving the chargeability, fluidity, and transferability of the toner. Examples of the external additive include inorganic particles such as silica, alumina, titania, zirconia, tin oxide and zinc oxide, and organic fine particles such as resin particles such as melamine resin fine particles and polytetrafluoroethylene resin fine particles. Two or more kinds may be used in combination. Among these, silica is preferable, and hydrophobic silica that has been subjected to a hydrophobic treatment is more preferable from the viewpoint of improving toner transferability.

  The number average particle diameter of the external additive is preferably 10 nm or more, more preferably 15 nm or more, more preferably 250 nm or less, and more preferably 200 nm or less, from the viewpoint of improving the chargeability, fluidity, and transferability of the toner. 90 nm or less is more preferable.

  The content of the external additive is 0.05 parts by mass with respect to 100 parts by mass of toner particles (toner base particles) before being processed with the external additive, from the viewpoint of improving the chargeability, fluidity, and transferability of the toner. The above is preferable, 0.1 part by mass or more is more preferable, and 0.3 part by mass or more is more preferable. Further, it is preferably 5 parts by mass or less, more preferably 4 parts by mass or less, and further preferably 3 parts by mass or less.

  For mixing the toner base particles and the external additive, it is preferable to use a mixer equipped with a stirring tool such as a rotary blade, a high speed mixer such as a Henschel mixer or a super mixer is preferable, and a Henschel mixer is more preferable.

The volume median particle size (D ₅₀ ) of the toner of the present invention is preferably 3 μm or more, more preferably 4 μm or more, and even more preferably 6 μm or more from the viewpoint of improving the image quality of the toner. Further, it is preferably 15 μm or less, more preferably 12 μm or less, and further preferably 9 μm or less. In the present specification, the volume-median particle size (D ₅₀ ) means a particle size at which the cumulative volume frequency calculated by the volume fraction is 50% when calculated from the smaller particle size. When the toner is treated with an external additive, the volume median particle size of the toner base particles is set as the volume median particle size of the toner.

  The toner of the present invention can be used in an image forming apparatus of a one-component development system or a two-component development system as a one-component development toner as it is or as a two-component development toner mixed with a carrier.

[Softening point of resin]
Using a flow tester “CFT-500D” (manufactured by Shimadzu Corporation), a 1 g sample was heated at a heating rate of 6 ° C./min, a 1.96 MPa load was applied by a plunger, a nozzle with a diameter of 1 mm and a length of 1 mm Extrude from. The amount of plunger drop of the flow tester is plotted against the temperature, and the temperature at which half of the sample flows out is taken as the softening point.

[Glass transition temperature of resin]
Using a differential scanning calorimeter “DSC210” (manufactured by Seiko Denshi Kogyo Co., Ltd.), 0.01 to 0.02 g of sample is weighed into an aluminum pan, heated up to 200 ° C., and from that temperature to -10 ° C. at a cooling rate of 10 ° C./min. Allow to cool. Next, the sample is heated and measured at a heating rate of 10 ° C./min. The glass transition temperature is defined as the temperature at the intersection of the base line extension below the maximum peak temperature of endotherm and the tangent line indicating the maximum slope from the peak rising portion to the peak apex.

[Acid value of the resin]
Measured according to the method of JIS K0070. However, only the measurement solvent is changed from the mixed solvent of ethanol and ether specified in JIS K0070 to the mixed solvent of acetone and toluene (acetone: toluene = 1: 1 (volume ratio)).

[Peak top molecular weight of resin (Mpt)]
The molecular weight of the resin is measured by the gel permeation chromatography (GPC) method shown below.
(1) Preparation of sample solution The toner is dissolved in tetrahydrofuran so that the concentration becomes 0.04 g / 10 mL. Next, this solution is filtered using a fluororesin filter “DISMIC-25JP” (manufactured by Advantech Co., Ltd.) having a pore size of 0.45 μm to remove insoluble components to obtain a sample solution.
(2) Molecular weight measurement Using the following measuring device and analytical column, tetrahydrofuran is flowed as an eluent at a flow rate of 1 mL per minute, and the column is stabilized in a constant temperature bath at 40 ° C. Inject 100 μL of the sample solution into the sample and perform measurement. The molecular weight of the sample is calculated based on a calibration curve prepared in advance. At this time, several types of monodisperse polystyrene (A-500 (5.0 × 10 ² ), A-1000 (1.01 × 10 ³ ), A-2500 (2.63 × 10 ³ ), A- 5000 (5.97 × 10 ³ ), F-1 (1.02 × 10 ⁴ ), F-2 (1.81 × 10 ⁴ ), F-4 (3.97 × 10 ⁴ ), F-10 (9.64 × 10 ⁴ ), F- 20 (1.90 × 10 ⁵ ), F-40 (4.27 × 10 ⁵ ), F-80 (7.06 × 10 ⁵ ), F-128 (1.09 × 10 ⁶ )) prepared as standard samples are used.
Measuring device: HLC-8220GPC (manufactured by Tosoh Corporation)
Analytical column: GMHXL + G3000HXL (manufactured by Tosoh Corporation)
The molecular weight at the peak top of the highest peak of the obtained GPC profile is calculated as the peak top molecular weight.

[Melting point of release agent]
Using a differential scanning calorimeter “DSC210” (manufactured by Seiko Denshi Kogyo Co., Ltd.), 0.01 to 0.02 g of sample is weighed into an aluminum pan, heated to 200 ° C, and from that temperature to 0 ° C at a cooling rate of 10 ° C / min. Cooling. Next, the sample is heated to 180 ° C. at a heating rate of 10 ° C./min and measured. The maximum peak temperature of the endotherm observed from the melting endothermic curve thus obtained is taken as the melting point of the release agent.

[Melting viscosity of release agent]
Measurement is performed using a B-type viscometer (LVT manufactured by Japan ST Johnson Co., Ltd.) by the Brookfield method, and the measurement sample is heated and measured at 100 ° C., which is equal to or higher than the melting temperature of the release agent.

[Number average particle diameter of external additives]
The particle size (average value of major axis and minor axis) of 500 particles is measured from a scanning electron microscope (SEM) photograph, and the average value is taken as the number average particle size.

[Volume-median particle size of toner]
Measuring machine: Coulter Multisizer II (Beckman Coulter, Inc.)
Aperture diameter: 100μm
Analysis software: Coulter Multisizer AccuComp version 1.19 (Beckman Coulter)
Electrolyte: Isoton II (Beckman Coulter, Inc.)
Dispersion: Emulgen 109P (manufactured by Kao Corporation, polyoxyethylene lauryl ether, HLB: 13.6) is dissolved in the electrolyte so as to have a concentration of 5% by mass.
Dispersion conditions: 10 mg of a measurement sample was added to 5 ml of the dispersion, and dispersed for 1 minute with an ultrasonic disperser, then 25 ml of the electrolyte was added, and further dispersed for 1 minute with an ultrasonic disperser. Prepare sample dispersion.
Measurement conditions: The sample dispersion is added to 100 ml of the electrolytic solution so that the particle size of 30,000 particles can be measured in 20 seconds, and 30,000 particles are measured. Determine the median particle size (D ₅₀ ).

Resin Production Example 1 [Resin A]
Ingredients other than trimellitic anhydride shown in Table 1 and tertiary butylcatechol 5g were placed in a 5 liter four-necked flask equipped with a nitrogen inlet tube, dehydrator tube, stirrer and thermocouple, and in a nitrogen atmosphere. The temperature was raised to 180 ° C., and the temperature was raised stepwise to 210 ° C. at a rate of 10 ° C./hr. After reacting at 210 ° C. for 3 hours, the reaction was conducted at 8 kPa for 1 hour. Next, the pressure was returned to normal pressure (101.3 kPa), trimellitic anhydride was added, reacted at normal pressure for 1 hour, and then reacted at 20 kPa until the desired softening point was reached to obtain a resin. Table 1 shows the physical properties of the obtained resin.

Resin Production Example 2 [Resin B, E, F, G, I, J, M, N, O]
The raw material monomer shown in Table 1 and 40 g of tin (II) 2-ethylhexanoate were placed in a 5-liter four-necked flask equipped with a nitrogen introduction tube, a dehydration tube, a stirrer, and a thermocouple. The reaction was carried out until the reaction rate reached 80% by raising the temperature to 235 ° C., and then the reaction was carried out at 8 kPa until the desired softening point was reached to obtain a resin. Table 1 shows the physical properties of the obtained resin. The reaction rate refers to a value of the amount of generated reaction water / theoretical generated water amount × 100.

Resin Production Example 3 [Resin C, D]
Raw material monomers other than trimellitic anhydride shown in Table 1 and 40 g of tin (II) 2-ethylhexanoate were placed in a 5-liter four-necked flask equipped with a nitrogen introduction tube, a dehydration tube, a stirrer, and a thermocouple. Then, the temperature was raised to 235 ° C. in a nitrogen atmosphere until the reaction rate reached 80%, and then the reaction was performed at 8 kPa for 1 hour. Next, lower the temperature to 210 ° C and return to normal pressure (101.3 kPa), add trimellitic anhydride, react at 210 ° C and normal pressure for 1 hour, and then reach the desired softening point at 15 kPa Reaction was performed to obtain a resin. Table 1 shows the physical properties of the obtained resin.

Resin Production Example 4 [Resin K]
Raw material monomers other than fumaric acid shown in Table 1 and 40 g of tin (II) 2-ethylhexanoate were placed in a 5-liter four-necked flask equipped with a nitrogen introduction tube, a dehydration tube, a stirrer and a thermocouple, In a nitrogen atmosphere, the temperature was raised to 235 ° C. until the reaction rate reached 80%, and then the reaction was carried out at 8 kPa for 1 hour. Next, the temperature is lowered to 180 ° C. and returned to normal pressure (101.3 kPa), 5 g of fumaric acid and tertiary butyl catechol are added, and the temperature is raised stepwise up to 210 ° C. at a rate of 10 ° C./hr. After reacting at 210 ° C. and normal pressure for 2 hours, the reaction was carried out at 8 kPa until the desired softening point was reached to obtain a resin. Table 1 shows the physical properties of the obtained resin.

[Α-Olefin Polymer Production Example 1 (Releasing Agent 1)]
“Linearene 26+” (manufactured by Idemitsu Kosan Co., Ltd., mainly a mixture of α-olefins having 26 or more carbon atoms) is distilled under reduced pressure (0.1 kPa) to obtain monomer A which is a fraction having a distillation temperature of 200 to 300 ° C. It was. The composition ratio of this fraction was C (carbon number, the same applies hereinafter) 24: 1 mol%, C26: 59 mol%, C28: 38 mol%, C30: 2 mol%.

  Next, after dehydrating the monomer A and toluene with dry nitrogen and activated alumina in a nitrogen atmosphere, a uniform supernatant solution was extracted at room temperature (25 ° C.), and the monomer A toluene solution (concentration 23) Mass%).

  Into a Schlenk bottle with an internal volume of 200 ml that has been dried by heating, 50 ml of the resulting toluene solution of monomer A is added, 0.5 mmol of triisobutylaluminum, (1,2'-dimethylsilylene) (2,1'-dimethylsilylene) bis (3 -Trimethylsilylmethylindenyl) zirconium dichloride (2 μmol) and dimethylanilinium tetrakispentafluorophenylborate (8 μmol) were added, and 0.15 MPa of hydrogen was added at 85 ° C. for polymerization for 60 minutes. After the completion of the polymerization reaction, the precipitated reaction product is separated at room temperature (25 ° C.), washed with toluene and acetone, and then dried under heating and reduced pressure to produce an α-olefin copolymer (release agent). 1) was obtained. The release agent 1 obtained had a melting point of 76 ° C. and a melt viscosity at 100 ° C. of 200 mPa · s.

[Α-Olefin Polymer Production Example 2 (Releasing Agent 2)]
“Linearene 26+” was distilled under reduced pressure (0.1 kPa) to obtain monomer B which was a fraction having a distillation temperature of 190 to 250 ° C. The composition ratio of this fraction was C24: 32 mol%, C26: 43 mol%, C28: 18 mol%, and C30: 7 mol%.

  Next, after dehydrating the monomer B and toluene with dry nitrogen and activated alumina in a nitrogen atmosphere, a uniform supernatant solution was extracted at room temperature (25 ° C.), and a toluene solution of monomer B (concentration 23) Mass%).

  Into a Schlenk bottle with an internal volume of 200 ml that has been dried by heating, 50 ml of the toluene solution of monomer B obtained is placed, 0.5 mmol of triisobutylaluminum, (1,2'-dimethylsilylene) (2,1'-dimethylsilylene) bis (3 -Trimethylsilylmethylindenyl) zirconium dichloride (2 μmol) and dimethylanilinium tetrakispentafluorophenylborate (8 μmol) were added and polymerized at room temperature for 180 minutes. After the completion of the polymerization reaction, the precipitated reaction product is separated at room temperature (25 ° C.), washed with toluene and acetone, and then dried under heating and reduced pressure to produce an α-olefin copolymer (release agent). 2) was obtained. The release agent 2 obtained had a melting point of 65 ° C. and a melt viscosity at 100 ° C. of 180 mPa · s.

[Α-olefin polymer production example 3 (release agent 3)]
“Linearene 2024” (manufactured by Idemitsu Kosan Co., Ltd., mainly a mixture of α-olefins having 18 to 26 carbon atoms) is distilled under reduced pressure (0.27 to 2.00 kPa) and is a fraction having a distillation temperature of 180 to 220 ° C. C was obtained. The composition ratio of this fraction was C20: 1 mol%, C22: 67 mol%, C24: 31 mol%, and C26: 1 mol%.

  2.8 kg of the obtained monomer C and 4 l of heptane were placed in a heat-dried 1 l autoclave, and the temperature was raised to a copolymerization temperature of 60 ° C., followed by 5 mmol of triisobutylaluminum, (1,2′-dimethylsilylene) (2, 20 μmol of 1′-dimethylsilylene) bis (3-trimethylsilylmethylindenyl) zirconium dichloride and 40 μmol of dimethylanilinium tetrakispentafluorophenylborate were added, 0.1 MPa of hydrogen was introduced, and copolymerization was performed for 8 hours. After completion of the copolymerization reaction, the reaction product was precipitated with acetone at room temperature (25 ° C.) and separated, followed by drying under heating and reduced pressure to obtain an α-olefin copolymer (release agent 3). . The release agent 3 obtained had a melting point of 62 ° C. and a melt viscosity at 100 ° C. of 130 mPa · s.

Examples 1 and 3 to 11 and Comparative Examples 1 to 12
Binder resin and release agent shown in Table 3, negative charge control agent “T-77” (Hodogaya Chemical Co., Ltd.) 1.0 part by mass, and carbon black “Mogul-L” (Cabot Specialty Chemicals) (Ink Co., Ltd.) 4.0 parts by mass was stirred and mixed with a Henschel mixer for 1 minute, and then melt-kneaded under the following conditions.

A co-rotating twin screw extruder PCM-30 (manufactured by Ikekai Tekko Co., Ltd.) was used. The operating conditions of the co-rotating twin screw extruder were a barrel set temperature of 100 ° C., a shaft rotation speed of 200 r / min (shaft rotation peripheral speed of 0.30 m / sec), and a mixture supply speed of 10 kg / hr.
The obtained resin kneaded product is cooled and pulverized and classified using an IDS pulverizer / classifier (manufactured by Nippon Pneumatic Co., Ltd.) so that the volume median particle size (D ₅₀ ) is 7.5 μm. Got.

  100 parts by weight of the obtained toner base particles, 1.0 parts by weight of hydrophobic silica “RY50” (manufactured by Nippon Aerosil Co., Ltd., number average particle size 40 nm) as an external additive, hydrophobic silica “R972” (manufactured by Nippon Aerosil Co., Ltd., number A toner was obtained by mixing 0.5 part by mass of an average particle size of 16 nm) with a Henschel mixer for 3 minutes.

Example 2
Binder resin and release agent shown in Table 3, negatively chargeable charge control agent “LR-147” (manufactured by Nippon Carlit) 1.0 parts by mass, copper phthalocyanine pigment “ECB-301” (manufactured by Dainichi Seika) After mixing 4.0 parts by mass with a Henschel mixer for 1 minute, the mixture was melt kneaded, pulverized and classified in the same manner as in Example 1 to obtain toner base particles.

  100 parts by weight of the obtained toner base particles, 1.0 part by weight of hydrophobic silica “RY50” (manufactured by Nippon Aerosil Co., Ltd., average particle size 40 nm) as an external additive, hydrophobic silica “R972” (manufactured by Nippon Aerosil Co., Ltd., average particles) Toner was obtained by mixing 0.5 parts by mass (diameter 16 nm) with a Henschel mixer for 3 minutes.

Test Example 1 [low temperature fixability]
Toner is mounted on the non-magnetic one-component developing device “OKI MICROLINE 5400” (Oki Data Co., Ltd.), the toner adhesion amount is adjusted to 0.50 mg / cm ² , and a solid image of 20 mm x 30 mm is printed on “Color Copy90 paper” ( Printed on Fuji Xerox Office Supply). A solid image was taken out before passing through the fixing machine to obtain an unfixed image. The paper with the unfixed image obtained was fixed to 120 ° C with a fixing roll temperature of 130 ° C using an external fixing machine modified from the fixing machine of the non-magnetic one-component developing device "OKI COREFIDO B431dn" (Oki Data). Fixing was performed at a fixing speed of / sec. Thereafter, the fixing roll temperature was set to 135 ° C., and the same operation was performed. While this was raised to 230 ° C. by 5 ° C., an unfixed image was fixed at each temperature to obtain a fixed image.
Wrap white paper “L paper” (manufactured by Xerox) around a 1000 g weight with a bottom of 50φ, place this weight on the image area obtained at each fixing temperature, and make 5 reciprocations at the width of the image area, before and after rubbing The image density was measured using an image density measuring device “SPM-50” (Gretag), and the ratio before and after rubbing ([image density after rubbing / image density before rubbing] × 100) was initially 90%. The temperature of the fixing roll that exceeded the minimum fixing temperature was used as an index of low-temperature fixability. The smaller the value, the better the low-temperature fixability. The results are shown in Table 3.

Test Example 2 [High temperature offset resistance]
Toner is mounted on the non-magnetic one-component developing device “OKI MICROLINE 5400” (Oki Data Co., Ltd.), the toner adhesion amount is adjusted to 0.50 mg / cm ² , and a solid image of 20 mm x 30 mm is printed on “Color Copy90 paper” ( Printed on Fuji Xerox Office Supply). A solid image was taken out before passing through the fixing machine to obtain an unfixed image. The paper with the unfixed image obtained was fixed to 120 ° C with a fixing roll temperature of 130 ° C using an external fixing machine modified from the fixing machine of the non-magnetic one-component developing device "OKI COREFIDO B431dn" (Oki Data). Fixing was performed at a fixing speed of / sec. Thereafter, the fixing roll temperature was set to 135 ° C. and the same operation was performed. This was performed while increasing the temperature up to 230 ° C by 5 ° C.
The obtained fixing image at 130 ° C. to 230 ° C. was visually confirmed, and the maximum temperature of the fixing roll in which the occurrence of hot offset was not observed was defined as the maximum fixing temperature. The results are shown in Table 3. In the table, “230 <” indicates that no hot offset was observed even in a fixed image at 230 ° C.

Test Example 3 [Streaks in Low Temperature and Low Humidity Environment (LL)]
A printer with a modified non-magnetic one-component developing device "OKI COREFIDO B431dn" is filled with toner, and a character image with a printing rate of 2% is printed on A4 size (210mm x 297mm) paper at low temperature and low humidity (10 ° C, 20%). When continuously printing 9000 sheets under the above environment, the occurrence of streaks on the surface of the developing roller is visually observed after every 1000 sheets are printed, and the value obtained by dividing 1 by 1000 and subtracting 1 for the first time. It was used as an index of streak suppression. That is, when the generation of streaks is recognized for the first time after printing 6000 sheets, (6000/1000) -1 = “5”. The larger the value, the better the suppression of streaks. The results are shown in Table 3. In the table, “9” indicates that no streak was observed even after printing 9,000 sheets.

Test Example 4 [Fog in high temperature and high humidity environment (HH)]
A printer with a modified non-magnetic one-component developing device "OKI COREFIDO B431dn" is filled with toner, and a character image with a printing rate of 2% is printed on A4 size (210mm x 297mm) paper at high temperature and high humidity (32 ℃, 85%). ) When printing 9000 sheets continuously under the above environment, the toner on the organic photoconductor (OPC) with blank paper in the middle of passing is attached to the mending tape every 1000 sheets printed, and the image density measuring instrument “SPM- 50 ”(manufactured by Gretag) was used to measure the color density, determine the difference from the color density of the mending tape itself before applying the toner, and divide the number of sheets where the color density difference is 0.05 or more for the first time by dividing it by 1000. A value obtained by subtracting 1 was used as an index for suppressing fog. That is, when the occurrence of fog is recognized for the first time after printing 6000 sheets, (6000/1000) -1 = “5”. The larger the value, the better the suppression of fog. The results are shown in Table 3. In the table, “9” indicates that no fog was observed even after printing 9,000 sheets.

  From the above results, the toners of Examples 1 to 11 are excellent in both low-temperature fixability and high-temperature offset resistance as compared with the toners of Comparative Examples 1 to 12, and the generation of streaks at low temperature and low humidity and high temperature and high It can be seen that the generation of fog under humidity is suppressed.

  The toner of the present invention is suitably used for developing latent images formed in electrophotography, electrostatic recording, electrostatic printing, and the like.

Claims (5)

A toner comprising a binder resin, a colorant, a release agent, and a charge control agent,
The binder resin contains a resin H and a resin L having different softening points;
The resin H is, softening point Ri der 140 ° C. or higher 170 ° C. or less, the content of tri- or higher polyhydric alcohols and tricarboxylic or higher polycarboxylic acid components, the total amount of the alcohol component and carboxylic acid component, a non-linear polyester Ru der 1 mol% or more,
The resin L is a softening point of 85 ° C. or higher 95 ° C. or less, a peak top molecular weight of Ri der 6000 8,000 or less, the content of tri- or higher polyhydric alcohols and tricarboxylic or higher polycarboxylic acid component, the alcohol the total amount of the component and the carboxylic acid component, an der Ru linear polyester less than 1 mole%,
The mass ratio of the resin H to the resin L (resin H / resin L) is 50/50 to 80/20,
The mold release agent contains an α-olefin polymer obtained by polymerizing a monomer containing 95 mol% or more of an α-olefin having 26 to 28 carbon atoms;
A toner in which the content of the α-olefin polymer is 0.5 parts by mass or more and 10 parts by mass or less with respect to 100 parts by mass of the binder resin.   The toner according to claim 1, wherein the softening point of the resin H is 145 ° C. or higher and 160 ° C. or lower.   The toner according to claim 1, wherein the peak top molecular weight of the resin L is 6500 or more and 7800 or less.   The toner according to claim 1, wherein the melting point of the α-olefin polymer is 60 ° C. or higher and 90 ° C. or lower.   The toner according to claim 1, which is a pulverized toner obtained by a melt kneading method.