JP4668828B2 - toner - Google Patents

Description

  The present invention relates to a toner used in an electrophotographic method, an electrostatic recording method, an electrostatic printing method, and the like, and a manufacturing method thereof.

There are two types of toner manufacturing methods: melt-kneading and pulverization methods, and wet-type manufacturing methods such as emulsion aggregation. Is difficult and impractical.
On the other hand, the wet manufacturing method includes, for example, toner particles composed of a resin and a colorant, and the toner particles are obtained by dispersing resin particles obtained by polyaddition reaction or polycondensation reaction in an aqueous medium. A method for producing a toner for developing an electrostatic charge image obtained through a step of salting out and fusing the resin particles in the dispersion in the aqueous medium (see Patent Document 1), a binder resin And a toner material containing a colorant are melt-kneaded, dissolved / dispersed in an organic solvent in which the binder resin can be dissolved or swelled, emulsified and dispersed in an aqueous medium, and then aggregated. Toner (see Patent Document 2) is disclosed.

JP 2004-271686 A JP 2002-296839 A

In order to improve the fixability, which is one of the important properties of toner, it is effective to add a release agent such as wax. However, when toner is produced by a wet method, the wax is soluble. Is likely to cause poor dispersion. In particular, in the emulsion aggregation method, unlike the melt-kneading method, a mechanical share is not added in the manufacturing process, so that it is generally more difficult to uniformly disperse the wax. If the dispersibility of the wax is not uniform, not only the low-temperature fixability is impaired, but also the durability is inferior, resulting in image deterioration.
In addition, since the conventional wet process toner uses an organic solvent, the organic solvent remaining in the toner is volatilized at the time of fixing, which causes an environmental problem.
An object of the present invention is to provide a toner excellent in fixability and durability even when the above releasing agent is used, and to provide a method for producing the toner excellent in environmental properties.

The present invention
(1) A step (I) of melt-kneading a toner resin containing a binder resin containing polyester and a release agent, and a step of emulsifying the melt-kneaded product obtained in step (I) in an aqueous medium ( II), a toner obtained by a method having (2), and (2) a step (I) of melt-kneading a toner material containing a binder resin containing polyester and a release agent, and the melt-kneading obtained in step (I) A method for producing a toner comprising the step (II) of emulsifying a product in an aqueous medium and the step (III) of aggregating and coalescing the emulsified particles obtained in the step (II),
About.

  According to the present invention, it is possible to provide a toner having a small particle diameter excellent in fixing property and durability even when a release agent is used. In addition, according to the present invention, it is possible to provide a toner manufacturing method that can efficiently manufacture the toner with good environmental performance.

The toner of the present invention emulsifies, in an aqueous medium, the step (I) of melt-kneading a toner material containing a binder resin containing polyester and a release agent, and the melt-kneaded product obtained in step (I). The toner obtained by the method having the step (II). Hereinafter, the toner of the present invention will be described.
The toner of the present invention is obtained through a step (I) of melt-kneading a toner raw material containing a binder resin containing polyester and a release agent.

The binder resin used in the toner of the present invention contains polyester from the viewpoints of colorant dispersibility, fixability, and durability. The content of the polyester is preferably 60% by weight or more, more preferably 70% by weight or more, still more preferably 80% by weight or more, and substantially 100% by weight from the viewpoint of fixing property and durability in the binder resin. Is more preferable.
Examples of binder resins other than polyester include known resins used in toners, such as styrene-acrylic resins, epoxy resins, polycarbonates, and polyurethanes.

The raw material monomer of the polyester is not particularly limited, and a known alcohol component and a known carboxylic acid component such as carboxylic acid, carboxylic acid anhydride, or carboxylic acid ester are used.
Examples of the alcohol component include alkylenes of bisphenol A such as polyoxypropylene-2,2-bis (4-hydroxyphenyl) propane and polyoxyethylene-2,2-bis (4-hydroxyphenyl) propane (carbon number of 2 to 3). ) Oxide (average addition mole number 1-16) adduct, ethylene glycol, propylene glycol, glycerin, pentaerythritol, trimethylolpropane, hydrogenated bisphenol A, sorbitol, or their alkylene (2-4 carbon atoms) oxide (average) Addition mole number 1-16) Additions etc. are mentioned.

The carboxylic acid component includes dicarboxylic acids such as phthalic acid, isophthalic acid, terephthalic acid, fumaric acid, maleic acid, adipic acid and succinic acid, alkyl groups having 1 to 20 carbon atoms such as dodecenyl succinic acid and octenyl succinic acid, or carbon. Trivalent or higher polyvalent carboxylic acids such as succinic acid, trimellitic acid and pyromellitic acid substituted with alkenyl groups of 2 to 20, anhydrides of these acids and alkyls of these acids (1 to 3 carbon atoms) ) Esters and the like.
The polyester can be produced, for example, by subjecting an alcohol component and a carboxylic acid component to condensation polymerization at a temperature of 180 to 250 ° C. in an inert gas atmosphere, if necessary, using an esterification catalyst.

From the viewpoint of storage stability of the toner, the softening point of the polyester is preferably 80 to 165 ° C, and the glass transition point is preferably 50 to 85 ° C. The acid value is preferably 4 to 35 mgKOH / g, more preferably 10 to 35 mgKOH / g, and still more preferably 15 to 35 mgKOH / g, from the viewpoint of manufacturability during emulsification. The desired softening point and acid value can be obtained by adjusting the condensation polymerization temperature and reaction time.
From the viewpoint of toner durability, the number average molecular weight of the polyester is preferably 1,000 to 10,000, more preferably 2,000 to 8,000.
In addition, from the viewpoint of chargeability, as an acid component, aromatic carboxylic acids such as terephthalic acid, trimellitic acid, isophthalic acid, and anhydrides thereof, fumaric acid, adipic acid, succinic acid, and derivatives and anhydrides thereof It is preferable to use a polyester obtained by using an aliphatic carboxylic acid together.

The softening point of the binder resin is preferably 80 to 165 ° C, the glass transition point is preferably 50 to 85 ° C, and the acid value is preferably 4 to 35 mgKOH / g, more preferably 10 to 35 mgKOH / g, and 15 to 35 mgKOH / g. g is more preferable.
Furthermore, it is preferable that the binder resin for toner of the present invention contains two types of polyesters having different softening points from the viewpoint of fixability and durability, and the softening point of one polyester (a) is 70. The softening point of the polyester of the other polyester (b) is preferably 115 ° C to 165 ° C.
The weight ratio (a / b) between the polyester (a) and the polyester (b) is preferably 10/90 to 90/10, and more preferably 50/50 to 90/10.

Examples of the release agent used in the toner of the present invention include solid paraffin wax, micro wax, rice wax, fatty acid amide wax, fatty acid wax, aliphatic monoketone, fatty acid metal salt wax, fatty acid ester wax, Examples thereof include partially saponified fatty acid ester waxes, silicone varnishes, higher alcohols, and carnauba waxes. Also, polyolefins such as low molecular weight polyethylene and polypropylene can be used. The above releasing agents can be used alone or in combination of two or more. The melting point of these releasing agents is preferably 60 to 90 ° C. from the viewpoint of fixability, and is preferably 65 to 90. Of these, paraffin wax having a melting point of 60 to 90 ° C. is preferable from the viewpoint of low-temperature fixing, and ester wax having a melting point of 60 to 90 ° C. is preferable from the viewpoint of compatibility with polyester. Is more preferable.

The melting point of the release agent can be determined by differential scanning calorimetry (DSC). That is, the melting peak value when a sample of several mg is ripened at a constant temperature increase rate, for example, (10 ° C./min) is defined as the melting point.
The content of the release agent is 0.5 to 20 parts by weight, preferably 1 to 18 parts by weight, more preferably 100 parts by weight of the binder resin, from the viewpoint of dispersibility in the binder resin and fixability. Is 1.5 to 15 parts by weight.

  Step (I) is a step of melt-kneading a toner raw material containing a binder resin containing polyester and a release agent. It is preferable to mix the raw materials mechanically and uniformly before the melt-kneading step of step (I). That is, the mixing step of mechanically mixing a toner component containing a binder resin and a release agent containing polyester and, if necessary, a colorant, a charge control agent, etc. is a mixer having a normal stirring blade, etc. There are no particular restrictions on the means.

The colorant is not particularly limited, and any known colorant can be used. Specifically, carbon black, inorganic composite oxide, chrome yellow, hansa yellow, benzidine yellow, sren yellow, quinoline yellow, permanent orange GTR, pyrazolone orange, vulcan orange, watch young red, permanent red, brilliantamine 3B, Brilliantamine 6B, DuPont Oil Red, Pyrazolone Red, Resol Red, Rhodamine B Lake, Lake Red C, Bengal, Methylene Blue Chloride, Phthalocyanine Blue, Phthalocyanine Green, Malachite Green Oxalate, Acridine, Xanthene, Azo Benzoquinone, azine, anthraquinone, indico, thioindico, phthalocyanine, aniline black, thiazole One of the various dyes and the like, alone or in combination of two or more can be used.
The content of the colorant is preferably 20 parts by weight or less, more preferably 0.01 to 10 parts by weight with respect to 100 parts by weight of the binder resin.

Examples of charge control agents include benzoic acid metal salts, salicylic acid metal salts, alkyl salicylic acid metal salts, catechol metal salts, metal-containing bisazo dyes, tetraphenylborate derivatives, quaternary ammonium salts, alkylpyridinium salts, and the like. Can be mentioned. These may be used individually by 1 type and may be used in combination of 2 or more type.
The content of the charge control agent is preferably 10 parts by weight or less, and more preferably 0.01 to 5 parts by weight with respect to 100 parts by weight of the binder resin.

  When the above mixing process is completed, the mixture is charged into a kneader and melt-kneaded. It is important that this melt-kneading is performed under appropriate conditions so as not to cause the molecular chains of the binder resin to be broken and the charge control agent and the release agent to be excessively dispersed. Specifically, the melt kneading temperature should be performed with reference to the softening point of the binder resin and the melting point of the release agent. If the temperature is too low from the softening point, the molecular chain is severely cut, and if it is too high, the charge control agent. And the release agent does not disperse. From this point, specifically, the heating temperature of the melt-kneading is preferably 70 to 200 ° C, more preferably 80 to 200 ° C.

  As the melt kneader for performing the melt kneading, a uniaxial or biaxial continuous kneader, a batch kneader by a roll mill, or an open roll kneader can be used. For example, KTK type manufactured by Kobe Steel, Ltd. Twin screw extruder, TEM type extruder manufactured by TOSHIBA MACHINERY CO., LTD., Twin screw extruder manufactured by K.C.K. Are preferably used. Among these, from the viewpoint of dispersibility of the release agent, a twin screw extruder and an open roll kneader are preferable, and an open roll kneader is more preferable. The twin screw extruder is preferably a PCM type twin screw extruder manufactured by Ikegai Iron Works, and the open roll type kneader is preferably an open roll type kneader manufactured by Mitsui Mining.

The open roll type kneader means a machine having at least two rolls and having an open type melt kneading unit. In the present invention, the kneader having at least two rolls of a heating roll and a cooling roll. Is preferably used. Such an open roll type kneader can easily dissipate kneading heat generated during melt kneading. The open roll kneader is preferably a continuous type from the viewpoint of production efficiency.
Further, in the open roll type kneader, the two rolls are arranged close to each other in parallel, and the gap between the rolls is preferably 0.01 to 5 mm, more preferably 0.05 to 2 mm. Further, the structure, size, material, and the like of the roll are not particularly limited, and the roll surface may be any of smooth, corrugated, uneven and the like.

The rotation speed of the roll, that is, the peripheral speed is preferably 2 to 100 m / min. The peripheral speed of the cooling roll is preferably 2 to 100 m / min, more preferably 10 to 60 m / min, and particularly preferably 15 to 50 m / min. The two rolls preferably have different peripheral speeds, and the ratio of the peripheral speeds of the two rolls (cooling roll / heating roll) is preferably 1/10 to 9/10. ˜8 / 10 is more preferable.
In order to make the kneaded material easily stick to the heating roll, the temperature of the heating roll is higher than both the softening point of the binder resin and the melting point of the release agent, and the temperature of the cooling roll is higher than the softening point of the binder resin. It is preferable that the temperature is adjusted to be lower than any temperature of the melting point of the mold. Specifically, the temperature of the heating roll is preferably 80 to 200 ° C, and the temperature of the cooling roll is preferably 20 to 140 ° C.

60-150 degreeC is preferable and the difference of the temperature of a heating roll and a cooling roll has more preferable 80-120 degreeC.
In addition, the temperature of a roll can be adjusted with the temperature of the heat medium passed through a roll inside, for example, and the inside of a roll may be divided into two or more and a heat medium having a different temperature may be passed through each roll.
The temperature of the heating roll, particularly the raw material charging side, is preferably higher than any of the softening point of the binder resin and the melting point of the release agent, and 0 to 80 ° C. higher than the higher one of them. Is more preferable, and it is still more preferable that it is 5-50 degreeC high. Further, the temperature of the cooling roll is preferably lower than any of the softening point of the binder resin and the melting point of the release agent, and is preferably 0 to 80 ° C. lower than the lower one of them. It is preferably 40 to 80 ° C. and particularly preferably.

Step (II) is a step of emulsifying the melt-kneaded product obtained in step (I) in an aqueous medium.
The aqueous medium used in this step may contain a solvent such as an organic solvent, an inorganic salt such as an alkali metal salt, etc., but preferably contains 95% by weight or more, more preferably 99% by weight or more. In particular, in the present invention, it is preferable to use only water without substantially using an organic solvent from the viewpoint of atomizing the binder resin.
In the emulsification step, from the viewpoint of improving the emulsification stability of the binder resin, the amount is preferably 5 parts by weight or less, more preferably 0.1 to 3.5 parts by weight, and still more preferably with respect to 100 parts by weight of the binder resin. Present 0.1 to 3 parts by weight of a surfactant.

Examples of the surfactant include anionic surfactants such as sulfate ester type, sulfonate type, phosphate ester type, and soap type; cationic surfactants such as amine salt type and quaternary ammonium salt type; polyethylene Nonionic surfactants such as glycol-based, alkylphenol ethylene oxide adduct-based, polyhydric alcohol-based and the like can be mentioned. Among these, ionic surfactants such as anionic surfactants and cationic surfactants are preferable. The nonionic surfactant is preferably used in combination with an anionic surfactant or a cationic surfactant. Although the said surfactant may be used individually by 1 type, you may use it in combination of 2 or more type. Specific examples of the anionic surfactant include sodium dodecyl benzene sulfonate, sodium dodecyl sulfate, sodium alkyl ether sulfate, sodium alkyl naphthalene sulfonate, sodium dialkyl sulfosuccinate and the like.
Specific examples of the cationic surfactant include alkylbenzene dimethyl ammonium chloride, alkyl trimethyl ammonium chloride, distearyl ammonium chloride and the like.

In step (II), it is preferable to add an alkaline aqueous solution equivalent to the acid group of the polyester in the binder resin to disperse the melt-kneaded product obtained in step (I).
In the dispersion of the melt-kneaded product obtained in the step (I), the alkaline aqueous solution preferably has a concentration of 1 to 20% by weight, more preferably 1 to 10% by weight, and 1.5 to 7. More preferred is a concentration of 5% by weight. As for the alkali to be used, it is preferable to use an alkali that enhances the surface activity when the polyester becomes a salt. Examples thereof include monovalent alkali metal hydroxides such as potassium hydroxide and sodium hydroxide.
After dispersion, neutralize at a temperature above the glass transition point of the binder resin, and then add water at a temperature above the glass transition point to produce a binder resin emulsion by phase inversion emulsification. Can do.

The water addition rate is preferably 0.5 to 50 g / min, more preferably 0.5 to 40 g / min, and even more preferably 0.5 to 30 g per 100 g of resin from the viewpoint of effectively emulsifying. / Min. This addition rate is generally maintained until an O / W type emulsion is substantially formed, and there is no particular limitation on the addition rate of water after the formation of the O / W type emulsion.
Further, the temperature at this time is preferably in the range of not less than the glass transition point and not more than the softening point of the binder resin from the viewpoint of preparing a fine resin emulsion. By carrying out the emulsification at a temperature within the above range, the emulsification is carried out smoothly and no special apparatus is required for heating. From this point, the temperature is preferably a glass transition point of the binder resin + 10 ° C. or more, and preferably a softening point of −5 ° C. or less.

The toner of the present invention can be obtained by subjecting the emulsion of the melt-kneaded product thus obtained to the step (III) of aggregating and coalescing the emulsified particles therein.
The volume-median particle size (D ₅₀ ) of the emulsified particles is preferably 0.02 to 2 μm, more preferably 0.05 to 1 μm, and still more preferably 0.05 to 0.05 in order to perform uniform aggregation in the aggregation process. 0.6 μm. 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.

  In the aggregation step of step (III), it is preferable to perform a step of aggregating the binder resin in the presence of a surfactant in order to control the aggregation speed and the shape of the toner. When a surfactant is added in the step (II), it is not necessary to add it further, but it can be added if necessary. In the aggregation process, the amount of the surfactant present in the system is preferably 5 parts by weight or less, more preferably 4.5 parts by weight or less, more preferably 3 parts by weight or less with respect to 100 parts by weight of the binder resin, from the viewpoint of toner chargeability. More preferable is 5 parts by weight or less. Moreover, from a viewpoint of productivity and shape control, 0.5 weight part or more is preferable and 1 weight part or more is more preferable. That is, the amount of the surfactant present in the aggregation step is preferably 5 parts by weight or less, more preferably 0.5 to 4.5 parts by weight, and more preferably 0.5 to 3.5 parts by weight with respect to 100 parts by weight of the binder resin. Part by weight is more preferred.

The solid content concentration in the system in the coagulation step can be adjusted by adding water to the emulsion of the binder resin. In order to cause uniform aggregation and sharpen the particle size distribution, it is 10 to 50% by weight. Is preferable, 15 to 50% by weight is more preferable, and 15 to 40% by weight is further preferable.
The temperature in the system in the aggregation process is preferably a softening point of the binder resin of −50 ° C. or higher and a softening point of −10 ° C. or lower, more preferably a softening point of −30 ° C. or higher and a softening point of −10 ° C. or lower.

  In the aggregation step, it is preferable to add an aggregating agent in order to effectively perform aggregation. As the aggregating agent, a quaternary salt cationic surfactant, an organic aggregating agent such as polyethyleneimine, an inorganic aggregating agent such as an inorganic metal salt, an ammonium salt or a divalent or higher metal complex is used. Examples of inorganic metal salts include metal salts such as sodium sulfate, sodium chloride, calcium chloride, calcium nitrate, barium chloride, magnesium chloride, zinc chloride, aluminum chloride, aluminum sulfate, polyaluminum chloride, polyaluminum hydroxide, Examples thereof include inorganic metal salt polymers such as calcium sulfide. Examples of ammonium salts include ammonium halide, ammonium sulfate, ammonium acetate, ammonium benzoate, and ammonium salicylate. Examples of quaternary ammonium salts include tetraalkylammonium halides.

The amount of the flocculant used is preferably 30 parts by weight or less, more preferably 0.01 to 20 parts by weight, and more preferably 0.1 to 100 parts by weight with respect to 100 parts by weight of the binder resin, from the viewpoint of the aggregation ability and the environmental resistance characteristics of the toner. More preferred is 10 parts by weight.
The flocculant is preferably added after being dissolved in an aqueous medium, and it is preferable to sufficiently stir at the time of adding the flocculant and after the addition.

Furthermore, in the present invention, from the viewpoint of aggregation control and the like, it is preferable to add a cationic or anionic hydrophilic polymer as a dispersant in the aggregation step.
Examples of the cationic polymer that can be used include cationized polyvinyl alcohol, cationized starch, cationized cellulose, polydimethylethyl methacrylate quaternary salt, and amino-modified silicone. Examples of the anionic polymer include polyacrylate, maleic acid α-olefin copolymer salt, polystyrene sulfonate, naphthalene sulfonate formalin condensate salt, and the like.
Among the above cationic polymers, cationized polyvinyl alcohol is preferable from the viewpoint of emulsification performance of the release agent and aggregation properties with the resin emulsified particles. Among the anionic polymers, polyacrylates or maleic acid α-olefin copolymer salts are preferable from the viewpoints of aggregation with the resin-emulsified particles and chargeability.

The amount of the cationic or anionic polymer used is preferably 0.01 to 10 parts by weight, more preferably 0.05 to 5 parts by weight with respect to 100 parts by weight of the binder resin.
In this invention, it is preferable to use together alkyl-modified polyvinyl alcohol and cationized polyvinyl alcohol from the viewpoint of the emulsifiability of the release agent and the aggregation property with the resin emulsified particles.

In the present invention, the agglomerated particles containing at least the polyester-containing binder resin and the release agent obtained in the aggregating step are heated and united (a uniting step).
The heating temperature for coalescing the aggregated particles is as follows: from the viewpoint of the target toner particle size, particle size distribution, shape control, and particle fusing property, the softening point of the binder resin is −55 ° C. or higher, and the softening point is +10. The softening point is preferably −50 ° C. or higher, the softening point + 10 ° C. or lower, more preferably the softening point −40 ° C. or higher, and the softening point + 10 ° C. or lower. Further, the stirring is preferably performed at a speed at which the aggregated particles do not settle.
In the present invention, the toner shape is changed from aggregated particles to coalesced particles by holding at the above temperature for a certain period of time.

A toner can be obtained by subjecting the coalesced particles obtained by the aggregation and coalescence process to a solid-liquid separation process such as filtration, a washing process, and a drying process as appropriate.
In the washing step, it is preferable to use an acid in order to remove metal ions on the toner surface in order to ensure sufficient charging characteristics and reliability as the toner. Further, it is preferable to completely remove the added nonionic surfactant by washing, and washing with an aqueous solution below the cloud point of the nonionic surfactant is preferred. The washing is preferably performed a plurality of times.
In the drying step, any method such as a vibration type fluidized drying method, a spray drying method, a freeze drying method, a flash jet method, or the like can be employed. The water content after drying of the toner is preferably adjusted to 1.5% by weight or less, more preferably 1.0% by weight or less, from the viewpoint of chargeability.

According to the present invention, a toner having a small particle size and a narrow particle size distribution suitable for high definition and high image quality can be obtained.
From the viewpoint of high image quality and productivity, the volume median particle size (D ₅₀ ) of the toner is preferably 1 to 8 μm, more preferably 2 to 8 μm, and even more preferably 3 to 7 μm.
Further, the softening point of the toner is preferably 60 to 140 ° C., more preferably 60 to 130 ° C., and further preferably 60 to 120 ° C. from the viewpoint of low-temperature fixability. Moreover, 60-140 degreeC is preferable from the same viewpoint, 60-140 degreeC is more preferable, and 60-130 degreeC is more preferable, as for the highest peak temperature of the endotherm by a differential scanning calorimeter. Here, the highest endothermic peak temperature is raised to, for example, 200 ° C. using a differential scanning calorimeter, and a sample heated from that temperature to, for example, about 0 ° C. at a rate of 10 ° C./min. It can be measured in ° C / min. Of the endothermic peaks observed, the peak temperature on the highest temperature side can be set as the highest endothermic peak temperature.

An auxiliary agent such as a fluidizing agent may be added to the toner particle surface as an external additive to the toner obtained by the present invention. External additives include known fine particles such as silica fine particles, titanium fine particles, alumina fine particles, cerium oxide fine particles, carbon black and other inorganic fine particles, and polymer fine particles such as polycarbonate, polymethyl methacrylate and silicone resin. Can be used.
The number average particle diameter of the external additive is preferably 4 to 200 nm, more preferably 8 to 100 nm, and still more preferably 8 to 50 nm. The number average particle diameter of the external additive is determined using a scanning electron microscope or a transmission electron microscope.

The amount of the external additive is preferably 1 to 5 parts by weight and more preferably 1.5 to 3.5 parts by weight with respect to 100 parts by weight of the toner before processing with the external additive. However, when hydrophobic silica is used as the external additive, the desired effect can be obtained by using 1 to 3 parts by weight of hydrophobic silica with respect to 100 parts by weight of the toner before processing with the external additive.
The toner for electrophotography obtained by the present invention can be used as a one-component developer or as a two-component developer by mixing with a carrier.

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

[Softening point and glass transition point of resin and toner]
(1) Softening point Using a flow tester (Shimadzu Corporation, CFT-500D), a 1 g sample was heated at a heating rate of 6 ° C./min. Extrude from a 1 mm nozzle. Plot the flow tester's Bwanger drop amount against temperature, and let the softening point be the temperature at which half of the sample flowed out.
(2) Glass transition point The temperature was raised to 200 ° C. using a differential scanning calorimeter (Seiko Denshi Kogyo Co., Ltd., DSC210), and the sample cooled to 0 ° C. at a temperature lowering rate of 10 ° C./min from that temperature Measured in ° C / min. When a peak is observed at a temperature 20 ° C. or more lower than the softening point, the peak temperature is measured. When a peak is not observed at a temperature 20 ° C. or higher lower than the softening point, a step is observed. The temperature at the intersection of the tangent line indicating the maximum slope of the curve and the extension line of the base line on the high temperature side of the step is read as the glass transition point. The glass transition point is a physical property peculiar to the amorphous part of the resin, and is generally observed in amorphous polyester, but is observed when amorphous part exists even in crystalline polyester. There is.

[Number average molecular weight of resin]
The molecular weight distribution is measured by gel permeation chromatography and the number average molecular weight is calculated by the following method.
(1) Preparation of sample solution Dissolve in tetrahydrofuran so that the concentration is 0.5 g / 100 ml. Subsequently, this solution is filtered using a fluororesin filter having a pore size of 2 μm (FP-200, manufactured by Sumitomo Electric Industries, Ltd.) to remove insoluble components to obtain a sample solution.
(2) Molecular weight measurement Tetrahydrofuran is allowed to flow as a solution at a flow rate of 1 ml per minute, and the column is stabilized in a constant temperature bath at 40 ° C. 100 μl of the sample solution is injected therein and measurement is performed. The molecular weight of the sample is calculated based on a calibration curve prepared in advance. The calibration curve at this time includes several types of monodisperse polystyrene (2.63 × 10 ³ , 2.06 × 10 ⁴ , 1.02 × 10 ⁵ , manufactured by Tosoh Corporation), and 2.10 × manufactured by GL Sciences, Inc. 10 ³ , 7.00 × 10 ³ , 5.04 × 10 ⁴ ) are used as standard samples.
Measuring device: CO-8010 (manufactured by Tosoh Corporation)
Analysis column: GMHLX + G3000HXL (manufactured by Tosoh Corporation)

[Particle size of resin dispersed particles]
(1) Measuring device: Laser diffraction type particle size measuring machine (LA-920, manufactured by HORIBA, Ltd.)
(2) Measurement conditions: Distilled water is added to the measurement cell, and the volume-median particle size (D ₅₀ ) is measured at a temperature at which the absorbance is in an appropriate range.

[Toner particle size]
(1) Preparation of dispersion: 10 mg of a measurement sample was added to 5 ml of dispersion [“Emulgen 109P” (Kao, polyoxyethylene lauryl ether, HLB: 13.6) 5 wt% aqueous solution] Then, 25 ml of electrolyte [“Iston II” (manufactured by Beckman Coulter, Inc.)] is added and further dispersed for 1 minute with an ultrasonic disperser to obtain a dispersion.
(2) Measuring device: “Coulter Multisizer II” (Beckman Coulter, Inc.)
Aperture diameter: 50 μm
Analysis software: “Coulter Multisizer AccuComp version 1.19” (Beckman Coulter, Inc.)
(3) Measurement conditions: 100 ml of electrolyte solution and dispersion were added to a beaker, and the volume median particle size (D ₅₀ ) of 30,000 particles at a concentration at which the particle size of 30,000 particles could be measured in 20 seconds. Ask for.

[Melting point of release agent]
Using a differential scanning calorimeter (DSC210, manufactured by Seiko Denshi Kogyo Co., Ltd.), the melting peak value when the sample is ripened at a heating rate of 10 ° C./min is defined as the melting point.

Production example 1 of polyester
8320 g of polyoxypropylene (2.2) -2, 2-bis (4-hydroxyphenyl) propane, polyoctylene (2.0) -2, 80 g of 2-bis (4-hydroxyphenyl) propane, 1592 g of terephthalic acid and dibutyltin 15 g of oxide was placed in a four-necked flask equipped with a nitrogen introduction tube, a dehydration tube, a stirrer, and a thermocouple, and stirred at 230 ° C. under a nitrogen atmosphere and normal pressure (101.3 kPa) for 5 hours. After cooling to 210 ° C., 1672 g of fumaric acid and 8 g of hydroquinone were added, reacted for 5 hours, further reacted under reduced pressure, and the reaction was stopped when the softening point measured according to ASTM D36-86 reached 110 ° C. Got. Polyester resin A had a softening point of 110 ° C., a glass transition point of 66 ° C., an acid value of 24.4 mgKOH / g, and a number average molecular weight of 3760.

Production example 2 of polyester
Polyoxypropylene (2.2) -2, 2-bis (4-hydroxyphenyl) propane 17500 g, polyoxyethylene (2.0) -2, 2-bis (4-hydroxyphenyl) propane 16250 g, terephthalic acid 11454 g, 1608 g of dodecenyl succinic anhydride, 4800 g of trimellitic anhydride and 15 g of dibutyltin oxide are placed in a four-necked flask equipped with a nitrogen introduction tube, a dehydration tube, a stirrer and a thermocouple, and stirred at 220 ° C. in a nitrogen atmosphere. The polyester resin B was obtained by reacting until the softening point measured according to ASTM D36-86 reached 120 ° C. Polyester resin B had a softening point of 121 ° C., a glass transition point of 65 ° C., an acid value of 18.5 mgKOH / g, and a number average molecular weight of 3394.

Production example 3 of polyester
12250 g of polyoxypropylene (2.2) -2, 2-bis (4-hydroxyphenyl) propane, 21125 g of polyoxyethylene (2.0) -2, 2-bis (4-hydroxyphenyl) propane, 15272 g of terephthalic acid and 15 g of dibutyltin oxide is placed in a four-necked flask equipped with a nitrogen introduction tube, a dehydration tube, a stirrer, and a thermocouple, stirred at 220 ° C. in a nitrogen atmosphere, and the softening point measured according to ASTM D36-86 is 105 ° C. It was made to react until it reached | attained and the polyester resin C was obtained. Polyester resin C had a softening point of 108 ° C., a glass transition point of 66 ° C., an acid value of 4.4 mgKOH / g, and a number average molecular weight of 4086.

Toner kneaded product production example 1
After mixing the raw materials comprising the following components for 3 minutes at a stirring speed of 1500 r / m using a 20 L Henschel mixer, it is melt-kneaded using an open roll type continuous kneader “NIDEX” (Mitsui Mining Co., Ltd.) The obtained toner kneaded product was cooled with a cooling belt and then roughly crushed with a mill having a 2 mmφ screen to obtain a toner kneaded product a. (The softening point was 114 ° C., the glass transition point was 65 ° C., and the acid value was 22.3.)
(material)
・ Polyester resin A 4550g
・ Polyester resin B 2450g
Carnauba wax No. 1 (Carnauba wax: manufactured by Kato Yoko Co., Ltd., melting point: 83 ° C.)
350g
-ECB-301 (copper phthalocyanine pigment: manufactured by Dainichi Seika Kogyo Co., Ltd.) 350 g

  The open roll type continuous kneader used has a roll outer diameter of 0.14 m and an effective roll length of 0.8 m, and the operating conditions are a heating roll (front roll) rotational speed of 33 m / min and a cooling roll (rear roll) The rotation speed of the roll) was 22 m / min, and the roll gap was 0.1 mm. The heating and cooling medium temperatures in the roll are 150 ° C. on the raw material input side of the heating roll, 130 ° C. on the kneaded material discharge side, 35 ° C. on the raw material input side of the cooling roll, and the kneaded material discharge side. Was set to 30 ° C. The feed rate of the raw material mixture was 5 kg / hour, and the average residence time was about 5 minutes.

Toner kneaded product production example 2
Toner kneaded product b was prepared in the same manner as in toner kneaded product production example 1, except that carnauba wax was changed to paraffin wax (“HNP-9: Nippon Seiki Co., Ltd., melting point: 78 ° C.)”.

Toner kneaded product production example 3
After mixing for 3 minutes using a 20 L Henschel mixer at a stirring speed of 1500 r / m with the same composition as in toner kneaded product production example 1, the barrel temperature was measured with a twin screw extruder “PCM-30” (manufactured by Ikegai Co., Ltd.). The mixture was melt kneaded at 100 ° C. and a rotation speed of 200 r / m. The obtained toner kneaded product was cooled with a cooling belt and then roughly crushed with a mill having a 2 mmφ screen to obtain a toner kneaded product c.

Toner kneaded product production example 4
Toner kneaded product d was produced in the same manner as in toner kneaded product production example 1, except that the material containing no carnauba wax was used.

Toner kneaded product production example 5
A toner kneaded product e was produced in the same manner as in the toner kneaded product production example 1 except that the polyester resin A was changed to the polyester resin C. (The softening point was 113 ° C., the glass transition point was 65 ° C., and the acid value was 9.3.)

Example 1
In a 5-liter stainless steel kettle, 1100 g of toner kneaded product a, 10.5 g of nonionic surfactant “Emulgen 430 (manufactured by Kao)” polyoxyethylene oleyl ether (HLB: 16.2), anionic surfactant “ Neoperex G-15 (manufactured by Kao) "Sodium dodecylbenzenesulfonate aqueous solution 70.0g (concentration: 15% by weight) and 420g of potassium hydroxide aqueous solution (concentration: 5% by weight) as a neutralizing agent were added. The mixture was dispersed at 95 ° C. with stirring at 150 r / min. The contents were stirred for 2 hours after reaching 95 ° C., and then 2200 g of deionized water was added dropwise at a rate of 6 g / min with stirring at 150 r / min with a Kai-type stirrer, and 200 mesh (opening: 105 μm). A finely divided resin dispersion was obtained through a wire mesh. The resin particles in the resulting resin dispersion had a volume-median particle size of 0.166 μm, a solid concentration of 30.1% by weight, and no resin component remained on the wire mesh.

450 g of the obtained resin dispersion was mixed in a 2 liter container at room temperature. Next, under stirring at 100 r / min with a Kai-type stirrer, 10.95 g of ammonium sulfate (molecular weight: 132.14) as a coagulant and cation-modified polyvinyl alcohol (K-210 (Nippon Synthesis) as a hydrophilic polymer were added to this mixture. A solution prepared by dissolving 8.3 g of a 5% by weight aqueous solution of a chemical industry)) in 502.68 g of deionized water was added dropwise at room temperature over 15 minutes. Thereafter, the mixed dispersion was heated at 1 ° C./5 min to form aggregated particles, and when the temperature reached 80 ° C., the temperature was increased to 90 ° C. at 0.25 ° C./min. Then, after fixing at 90 degreeC and stirring for 4 hours, the heating was stopped. During this time, the toner shape changed from aggregated particles to coalesced particles.
The solution was gradually cooled to room temperature, and colored resin fine particle powder was obtained through a suction filtration step, a washing step and a drying step. The volume median particle size (D ₅₀ ) of the colored fine resin particle powder was 6.0 μm, and the water content was 0.3% by weight.
To 100 parts by weight of the colored resin fine particle powder, 1.0 part by weight of hydrophobic silica (manufactured by Wacker Chemie, TS530, primary number average particle diameter: 8 nm) was externally added using a Henschel mixer to obtain a cyan toner. . With the obtained cyan toner, a good image was obtained with a commercially available full color printer. The glass transition point was 57 ° C.

Example 2
A toner was prepared in the same manner as in Example 1 except that the toner kneaded product a was changed to the toner kneaded product b. The volume median particle size of the resin particles in the obtained resin dispersion was 0.175 μm, and the solid concentration was 30.0% by weight. The volume-average particle size (D ₅₀ ) of the colored resin fine particles after aggregation and coalescence was 5.6 μm, and the water content was 0.3% by weight.
To 100 parts by weight of the colored resin fine particle powder, 1.0 part by weight of hydrophobic silica (manufactured by Wacker Chemie, TS530, primary number average particle diameter: 8 nm) was externally added using a Henschel mixer to obtain a cyan toner. . With the obtained cyan toner, a good image was obtained with a commercially available full color printer. The glass transition point was 57 ° C.

Example 3
A toner was prepared in the same manner as in Example 1 except that the toner kneaded product a was changed to the toner kneaded product c. The volume median particle size of the resin particles in the obtained resin dispersion was 0.272 μm, and the solid concentration was 30.0% by weight. The volume-average particle size (D ₅₀ ) of the colored resin fine particles after aggregation and coalescence was 6.8 μm, and the water content was 0.4% by weight.
To 100 parts by weight of the colored resin fine particle powder, 1.0 part by weight of hydrophobic silica (manufactured by Wacker Chemie, TS530, primary number average particle diameter: 8 nm) was externally added using a Henschel mixer to obtain a cyan toner. . With the obtained cyan toner, a good image was obtained with a commercially available full color printer. The glass transition point was 57 ° C.

Example 4
Using the resin dispersion obtained in Example 1 (volume median particle size is 0.166 μm, solid concentration is 30.1 wt%), cation-modified polyvinyl alcohol (K-210 (Nippon Synthetic Chemical) A toner was prepared by agglomeration and coalescence in the same manner as in Example 1 except that 8.3 g of a 5% by weight aqueous solution manufactured by Kogyo Co.) was not used. The volume-median particle size (D ₅₀ ) of the colored resin fine particles after aggregation and coalescence was 6.2 μm, and the water content was 0.3% by weight.
To 100 parts by weight of the colored resin fine particle powder, 1.0 part by weight of hydrophobic silica (manufactured by Wacker Chemie, TS530, primary number average particle diameter: 8 nm) was externally added using a Henschel mixer to obtain a cyan toner. . With the obtained cyan toner, a good image was obtained with a commercially available full color printer. The glass transition point was 57 ° C.

Example 5
A toner was prepared in the same manner as in Example 1 except that the toner kneaded material a was changed to the toner kneaded material e. The volume median particle size of the resin particles in the obtained resin dispersion was 0.311 μm, and the solid concentration was 30.6% by weight. The volume-average particle size (D ₅₀ ) of the colored resin fine particles after aggregation and coalescence was 7.7 μm, and the water content was 0.3% by weight.
To 100 parts by weight of the colored resin fine particle powder, 1.0 part by weight of hydrophobic silica (manufactured by Wacker Chemie, TS530, primary number average particle diameter: 8 nm) was externally added using a Henschel mixer to obtain a cyan toner. . With the obtained cyan toner, a good image was obtained with a commercially available full color printer. The glass transition point was 61 ° C.

Comparative Example 1
A resin dispersion was prepared in the same manner as in Example 1 except that the toner kneaded product a was changed to the toner kneaded product d. The volume median particle size of the resin particles in the obtained resin dispersion was 0.188 μm, and the solid concentration was 30.2% by weight.
435 g of the obtained resin dispersion was mixed in a 2 liter container at room temperature. Next, 15 g of carnauba wax emulsion (EMUSTAR-0413: manufactured by Nippon Seiki Co., Ltd.) was added dropwise with stirring at 100 r / min with a Kai-type stirrer. To this mixture, 10.95 g of ammonium sulfate (molecular weight: 132.14) as a flocculant and 8.3 g of a 5% by weight aqueous solution of cation-modified polyvinyl alcohol (K-210 (manufactured by Nippon Synthetic Chemical Industry)) as a water-soluble polymer were added. An aqueous solution dissolved in 502.68 g of deionized water was added dropwise at room temperature over 15 minutes. Thereafter, the mixed dispersion was heated at 1 ° C./5 min to form aggregated particles, and when the temperature reached 80 ° C., the temperature was raised to 90 ° C. at 0.25 ° C./min. Then, after fixing at 90 degreeC and stirring for 4 hours, the heating was stopped. During this time, the toner shape changed from aggregated particles to coalesced particles.

The solution was gradually cooled to room temperature, and colored resin fine particle powder was obtained through a suction filtration step, a washing step and a drying step. The volume median particle size (D ₅₀ ) of the colored resin fine particle powder was 5.8 μm, and the water content was 0.3% by weight.
To 100 parts by weight of the colored resin fine particle powder, 1.0 part by weight of hydrophobic silica (manufactured by Wacker Chemie, TS530, primary number average particle diameter: 8 nm) was externally added using a Henschel mixer to obtain a cyan toner. . The obtained cyan toner was mounted on a commercially available full color printer, but a good image was not obtained. The glass transition point was 57 ° C.

Each of the toners of Examples 1 to 5 and Comparative Example 1 was evaluated for low-temperature fixability and durability by the following method. The results are shown in Table 1.
<Minimum fixing temperature>
With respect to the obtained toner, the minimum fixing temperature was examined using an oilless fixing unit of a non-magnetic one-component electrophotographic printer capable of 23 A4 portrait printing per minute. For the minimum fixing temperature, a solid image is pasted on a mending tape, and when it is peeled off, the change in the image density is checked, and the image density after peeling is fixed at 90% or more of the original image density. It was judged that
A: Fixing is possible even at a temperature of 130 ° C. or less. ○: A temperature of 131 ° C. to 150 ° C. is the minimum fixing temperature. X: A temperature of 151 ° C. or more is the minimum fixing temperature.

<Durability>
With respect to the obtained toner, 80 g of toner is attached to the developing unit of a non-magnetic one-component electrophotographic printer, and a jig is prepared so that the developing unit can be stirred and rotated in the same manner as the actual speed, and stirred for 30 minutes. When this was done, the appearance of streaks on the developing roll was observed.
A: No more than 2 streaks and no problem with durability.
○: There are 3 to 5 streaks, and there is no problem in durability.
(Triangle | delta): There is no problem in durability in actual use at 6-10 lines.
X: There are 11 streaks or more in actual use.

以上より、実施例のトナーは、比較例のものと対比して、良好な低温定着性及び耐久性を達成できていることが分かる。

From the above, it can be seen that the toners of the examples can achieve good low-temperature fixability and durability compared with those of the comparative examples.

The toner of the present invention is excellent in fixability and durability even when a release agent is used. For electrophotography, the toner is mixed with a one-component developer or mixed with a carrier into a two-component developer. It can be preferably used.

Claims (6)

A step of melt-kneading toner materials containing a binder resin and a release agent containing a polyester (I), the step of the melt-kneaded product obtained in step (I) is emulsified in an aqueous medium (II), and step A method for producing a toner , comprising the step (III) of aggregating and coalescing the emulsified particles obtained in (II) . The method for producing a toner according to claim 1, wherein the melt kneading in the step (I) is performed using an open roll kneader. The toner production method according to claim 1, wherein the releasing agent has a melting point of 60 to 90 ° C. The method for producing a toner according to claim 1, wherein the polyester has an acid value of 4 to 35 mg KOH / mg. Step a solids concentration of 10 to 50 wt% in the system in the aggregation and coalescence steps (III), method for producing a toner according to any one of claims 1 to 4. The toner production according to any one of claims 1 to 5, wherein in the aggregation / unification step of step (III), 0.01 to 10 parts by weight of a hydrophilic polymer is added to 100 parts by weight of the binder resin. Way .