JP2010102024A - Ester wax and binder resin for toner containing the same, and the toner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve low temperature fixability, blocking resistance and printing durability of toner, to provide a binder resin containing an ester wax for improving low temperature fixability, blocking resistance and printing durability, and to provide toner containing the binder resin and having excellent low temperature fixability, blocking resistance and printing durability. <P>SOLUTION: The following polyglycerin fatty acid ester is used as an ester wax improving low temperature fixability, blocking resistance and printing durability of a toner. The polyglycerin fatty acid ester contains a saturated fatty acid having 16 to 22 carbon atoms as a structural fatty acid and has a hydroxyl number of 12 to 30 mgKOH/g. By compounding the polyglycerin fatty acid ester with the toner, the low temperature fixability, blocking resistance and printing durability of the toner are improved. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention contains a polyglycerol fatty acid ester having an effect of improving low-temperature fixability, blocking resistance and printing durability of a toner used for developing an electrostatic image in electrophotography and the like, and the polyglycerol fatty acid ester The present invention relates to a toner binder resin and toner.

  Toner is used as a developer for electrophotographic plain paper copiers, laser printers, and the like. The toner production methods include a mechanical pulverization method, a polymerization method, a powder fog drying method, and the like, each having its own characteristics. However, in terms of safety, quality stability, and production efficiency, 80% to 90% of the total toner is produced by a mechanical grinding method. The mechanical pulverization method is a method in which each component such as a binder resin and a colorant is melted and kneaded in a binder resin, and pulverized and classified to produce a toner. Therefore, the toner particles are not uniform in particle size because they are finely divided by mechanical force. If the particle size is not uniform, the fluidity and frictional chargeability of the toner are deteriorated, so that it is difficult to obtain a good fine image. On the other hand, the polymerization method is a method capable of improving the uniformity of particles, and since a uniform spherical toner can be obtained, it has been widely used in recent years as a method capable of producing a toner having higher performance than conventional pulverized toner. Yes. The polymerization method is a method of obtaining a toner by polymerizing a monomer mixture containing a polymerizable monomer, a colorant, a charge control agent, a release agent and the like in an aqueous dispersion medium containing a dispersion stabilizer. In the case of a styrene-acrylic resin, production methods such as an emulsion polymerization method and a suspension polymerization method are known. In the case of a polyester resin, an ester elongation polymerization method, a dissolution suspension method, CM ( Chemical milling method) is known.

  By the way, with the spread of personal computers recently, as toner for laser printers and digital multifunction devices, it can contribute to energy saving, it can respond to high speed printing and copying, it can respond to full color, it is required for toner such as being environmentally friendly The items that are being made are becoming more sophisticated. The most energy consuming part of a copier or printer is the process of fixing toner to paper. Generally, in this fixing process, heat and pressure are passed between a fixing roller containing a heater and a pressure roller through a transfer material. A heat roller fixing method is used in which fixing is performed in combination. However, in the heat roller fixing system, the toner on the transfer material is pressed against the roller, so that a so-called offset phenomenon that the molten toner adheres to the roller surface and stains the subsequent transfer material is likely to occur.

  Further, in the fixing process employing the heat roller fixing method, it is usually necessary to set the temperature of the fixing roller to 150 ° C. or higher, and a large amount of power is consumed as an energy source. In recent years, there has been a demand for lowering the temperature of the fixing roller (fixing temperature) at the time of fixing due to an increase in demand for reduction in power consumption and increase in printing speed and copying speed in image forming apparatuses.

  In response to the demand for reduction in power consumption and speedup of the image forming apparatus, the design of toner (low temperature fixing toner) that can be fixed on a transfer material even when the temperature of the fixing roller is low is being studied. For example, attempts have been made to use a resin having a low molecular weight component, a resin having a low melting point component, etc. as the resin constituting the toner.

  However, if the molecular weight or melting point of the resin constituting the toner is excessively lowered, the toner can be fixed at a low temperature in the toner fixing step, but the offset phenomenon is not improved. Further, when the toner is stored, a so-called blocking phenomenon in which the toner particles are fused to each other is caused, resulting in a problem that the storage stability of the toner is deteriorated.

  For this reason, during toner storage, toner storage stability (blocking resistance) is maintained, and in the toner fixing process, low-temperature fixing is possible (low-temperature fixability), and no offset phenomenon occurs (offset resistance) The development of a toner having excellent printing performance such as no fogging (printing durability) even when a large amount of printing is performed is required.

  As a wax that solves such a problem, Patent Document 1 uses a polyfunctional ester wax having an acid value of 1 mgKOH / g or less and a hydroxyl value of 10 mgKOH / g or less. In Patent Document 2, a polyglycerin fatty acid ester having an acid value of 3 mgKOH / g or less and a hydroxyl value of 5 mgKOH / g or less is used. Further, in Patent Document 3, a diglycerin fatty acid ester having an acid value of 10 mgKOH / g or less and a hydroxyl value of 10 mgKOH / g or less is used. Although these ester waxes with extremely low acid and hydroxyl values have improved heat melting properties, the ester wax may be slightly incorporated into the resin due to poor adhesion to paper or because the polarity is too low. There were cases where it was difficult to disperse. Moreover, in order to obtain polyglycerin fatty acid esters of these qualities, it is difficult to obtain only by esterification reaction of the raw material polyglycerin and fatty acid, unreacted free fatty acid components remaining in the esterification reaction product, In order to remove the partial ester component, it was necessary to carry out a purification step such as a water separation treatment. There has been concern about an increase in manufacturing cost due to the implementation of this purification step. On the other hand, in patent document 4, the partial ester of polyglycerol and a fatty acid is used. Since these partial esters have a higher polarity than the above-described ester wax having a very small hydroxyl value, they may be dissolved in the resin and may significantly reduce the glass transition temperature of the resin. Therefore, it cannot be said that the improvement in low-temperature fixing property, blocking resistance and printing durability is sufficient.

JP 2006-276293 A JP 2008-89909 A JP 2006-268056 A Japanese Patent No. 2697953

  Therefore, the object of the present invention is to achieve excellent effects of reducing the fixing temperature of the toner and preventing blocking, regardless of the toner production method and the type of resin, in which the wax is finely dispersed in the binder resin. An object of the present invention is to provide an ester wax that improves low-temperature fixability, blocking resistance, and printing durability, and to produce the ester wax inexpensively and easily. Furthermore, the present invention provides a binder resin containing an ester wax that improves low-temperature fixability, blocking resistance, and printing durability, and a toner having excellent low-temperature fixing properties, blocking resistance, and printing durability. The purpose is to do.

  In order to solve the above-mentioned problems, the present inventor has conducted extensive research, and as a result, the constituent fatty acid is a polyglycerol fatty acid ester composed of a saturated fatty acid having 16 to 22 carbon atoms, and the hydroxyl value of the polyglycerol fatty acid ester is as follows. The present inventors have found that the above-mentioned problems can be solved by setting the ratio to 12 to 30 mgKOH / g.

  The toner to which the polyglycerin fatty acid ester of the present invention is added has an excellent improvement effect in any of low-temperature fixability, blocking resistance, and printing durability because the ester wax is highly finely dispersed in the resin. Therefore, by blending a specific amount of the polyglycerin fatty acid ester of the present invention, a toner excellent in low-temperature fixability, blocking resistance and printing durability can be obtained, and can be suitably used for an image forming apparatus for high-speed printing.

  The present invention is described in detail below.

  The polyglycerol fatty acid ester used in the present invention includes palmitic acid, stearic acid, and behenic acid as constituent fatty acids. These may be used alone or in combination of two or more.

The polyglycerol of the polyglycerol fatty acid ester used in the present invention has an average degree of polymerization calculated from the hydroxyl value of 2 to 20, preferably 2 to 10. Moreover, the polyglycerol of this range may be used independently, or 2 or more types may be used together. Here, the average degree of polymerization is the average degree of polymerization (n) of polyglycerin calculated from the hydroxyl value by end group analysis. Specifically, the average degree of polymerization is calculated from the following formulas (Formula 1) and (Formula 2).
(Formula 1) Molecular weight = 74n + 18
(Formula 2) Hydroxyl value = 56110 (n + 2) / Molecular weight The hydroxyl value in the above (Formula 2) is a numerical value that is an index of the number of hydroxyl groups contained in polyglycerin, and is free contained in 1 g of polyglycerin. The number of milligrams of potassium hydroxide required to neutralize the acetic acid required to acetylate the hydroxyl group. The number of milligrams of potassium hydroxide is calculated according to the Japan Oil Chemists 'Society edited by “The Japan Oil Chemists' Society, Standard Oil Analysis Test Method (I), 2003 edition”.

  Further, the esterification rate of the polyglycerol fatty acid ester needs to be 80% to 92%, preferably 85% to 92%. When the esterification rate is less than 80% or exceeds 92%, the dispersibility for the resin is lowered. As a result, the low temperature fixing property and blocking resistance of the toner are deteriorated, and a desired performance cannot be obtained, or the amount used is likely to be limited. Here, the esterification rate is the average degree of polymerization of polyglycerol (n) calculated from the hydroxyl value by end group analysis, the number of hydroxyl groups (n + 2) of this polyglycerol, and the fatty acid added to the polyglycerol. When the number of moles is (M), (M / (n + 2)) × 100 = value calculated by esterification rate (%). The hydroxyl value is a value calculated in the same manner as the hydroxyl value described above.

  Furthermore, the hydroxyl value of polyglycerol fatty acid ester is 12-30 mgKOH / g, Preferably it is 12-25 mgKOH / g. When the hydroxyl value is out of the range of 12 to 30 mgKOH / g, the dispersibility with respect to the resin is reduced or the resin is compatible with the resin. As a result, the low temperature fixing property and blocking resistance of the toner are deteriorated, and a desired performance cannot be obtained, or the amount used is likely to be limited. Here, the hydroxyl value is a value calculated in the same manner as the hydroxyl value described above.

  Examples of the binder resin in the present invention include, but are not limited to, a styrene / acrylic copolymer resin, an epoxy resin, a polystyrene resin, a polyester resin, a polycarbonate resin, a polyurethane resin, and a resin that combines several of these.

  The toner of the present invention may be either dry toner or liquid toner. In the case of a dry toner, a colorant, a charge control agent, a release agent and the like are generally dispersed in a binder resin, and may be a one-component toner or a two-component toner. Furthermore, it may be magnetic or non-magnetic. Further, if necessary, additives for toner such as silicon dioxide, metal soap, and polyolefin wax may be blended. Similarly, in the case of a liquid toner, in addition to a colorant and a charge control agent, a hydrocarbon oil or vegetable oil as a carrier, and a dispersant for dispersing a resin in these are generally blended. Yes, it does not matter whether it is a one-component toner, two-component toner, magnetic or non-magnetic.

  Further, although the method for producing a toner can use the polyglycerin fatty acid ester of the present invention, it can be applied without being limited to a mechanical pulverization method, a powder mist drying method, a polymerization method, a microcapsule method and the like.

  EXAMPLES Next, although an Example and a comparative example demonstrate this invention in detail, this invention is not limited only to these Examples. The polyglycerin used this time is diglycerin S, polyglycerin # 500, and # 750 (both manufactured by Sakamoto Yakuhin Kogyo Co., Ltd.), and the average degree of polymerization calculated from the hydroxyl value is 2, 6 and 10, respectively. . Examples of the present invention and comparative examples are shown below. However, parts and% are based on weight unless otherwise specified.

(Synthesis of polyglycerol fatty acid esters of WAX 1-6 and 9-14)
100 g of diglycerin S and 571 g of palmitic acid are placed in a reaction vessel and reacted at 240 ° C. under a catalyst and a nitrogen stream. Diglycerin palmitate (WAX1) having an average esterification rate of about 92% and a hydroxyl value of 18 mgKOH / g Got. Similarly, WAX 2-6 and 9-14 were produced by changing the types of polyglycerol and fatty acid, and the molar ratio of fatty acid to polyglycerol, and are shown in Table 1.

(Synthesis of purified product of polyglycerol fatty acid ester of WAX7-8)
100 g of diglycerin S and 704 g of stearic acid were put in a reaction vessel and reacted at 240 ° C. under a catalyst and a nitrogen stream. Next, after the obtained reaction product was diluted in a mixed solvent of toluene and ethanol, an aqueous sodium hydroxide solution was added and stirred at 70 ° C. for 30 minutes. Then, it left still for 30 minutes and removed the water layer part. Furthermore, after adding ion-exchanged water and stirring at 70 ° C. for 30 minutes, the operation of leaving for 30 minutes and removing the aqueous layer was repeated 4 times, and the solvent was distilled off from the resulting ester layer under reduced pressure conditions. A purified diglycerin stearate (WAX7) having an average esterification rate of about 100%, an acid value of 0.3 mgKOH / g, and a hydroxyl value of 1.5 mgKOH / g was obtained. Moreover, WAX8 which changed the kind of fatty acid was manufactured similarly, and was shown in Table 1.

Example 1
Core monomer consisting of 80.5 parts of styrene and 19.5 parts of n-butyl acrylate, 7 parts of carbon black, 1 part of antistatic agent, 0.3 part of divinylbenzene, 0.5 part of polymethacrylate macromonomer Part and 15 parts of diglycerin palmitate (WAX1) were added, mixed and dissolved to obtain a polymerizable monomer composition for the core. All adjustments of the polymerizable monomer composition for the core were performed at room temperature.

  On the other hand, an aqueous solution in which 5.8 parts of magnesium hydroxide is dissolved in 50 parts of ion-exchanged water is gradually added with stirring to an aqueous solution in which 9.5 parts of magnesium chloride is dissolved in 250 parts of ion-exchanged water at room temperature. A magnesium oxide colloidal dispersion was prepared. All of the dispersions were adjusted at room temperature. When the particle size distribution of the colloid was measured with a laser diffraction scattering method particle size distribution analyzer (manufactured by Beckman Coulter, Inc.), the volume average particle diameter corresponding to 50% of the volume average particle diameter Dv50 (unit: μm) was 0. .30 μm.

  To the magnesium hydroxide colloidal dispersion obtained as described above, the above-mentioned core polymerizable monomer composition was charged at room temperature and stirred until the droplets were stabilized. After adding 6 parts of t-butylperoxyneodecanoate as a polymerization initiator, the mixture was stirred at high shear for 30 minutes at 15,000 rpm using an in-line type disperser, and droplets of the monomer mixture were formed. Granulated. This granulated monomer mixture aqueous dispersion was put into a 10 L reactor, and a polymerization reaction was started at 60 ° C. Next, 3 parts of methyl methacrylate and 30 parts of ion-exchanged water were finely dispersed with an ultrasonic emulsifier at room temperature to obtain an aqueous dispersion of a polymerizable monomer for shell. This shell polymerizable monomer and 0.3 part of ammonium persulfate as a water-soluble initiator are dissolved in 65 parts of distilled water, put into a reactor, polymerization is continued for 4 hours, the reaction is stopped, and toner particles An aqueous dispersion was obtained.

  While stirring the aqueous dispersion of the core-shell type polymer particles obtained above at room temperature, acid washing with sulfuric acid, separating the water by filtration, and then adding 500 parts of ion-exchanged water to make a slurry, Water washing was performed. Thereafter, dehydration and water washing were repeated again several times at room temperature, the solid content was filtered, and then dried at 45 ° C. for a whole day and night in a dryer to obtain polymer particles. To 100 parts of the polymer particles, 0.6 part of colloidal silica hydrophobized at room temperature was added and mixed using a Hensyl mixer to obtain a polymerization method toner.

(Example 2)
The diglycerin palmitate (WAX1) used in Example 1 was replaced with diglycerin stearate (WAX2). Otherwise, the toner was obtained in the same manner as in Example 1.

(Example 3)
The diglycerin palmitate (WAX1) used in Example 1 was replaced with diglycerin behenate (WAX3). Otherwise, the toner was obtained in the same manner as in Example 1.

Example 4
Diglycerin palmitate (WAX1) used in Example 1 was replaced with hexaglycerin behenate (WAX4). Otherwise, the toner was obtained in the same manner as in Example 1.

(Example 5)
The diglycerin palmitate (WAX1) used in Example 1 was replaced with decaglycerin stearate (WAX5). Otherwise, the toner was obtained in the same manner as in Example 1.

(Example 6)
The diglycerin palmitate (WAX1) used in Example 1 was replaced with decaglycerin behenate (WAX6). Otherwise, the toner was obtained in the same manner as in Example 1.

(Comparative Example 1)
The diglycerol palmitate (WAX1) used in Example 1 was replaced with a purified diglycerol stearate (WAX7). Otherwise, the toner was obtained in the same manner as in Example 1.

(Comparative Example 2)
The diglycerin palmitate (WAX1) used in Example 1 was replaced with a purified diglycerin behenate product (WAX8). Otherwise, the toner was obtained in the same manner as in Example 1.

(Comparative Example 3)
The diglycerin palmitate (WAX1) used in Example 1 was replaced with diglycerin palmitate (WAX9). Otherwise, the toner was obtained in the same manner as in Example 1.

(Comparative Example 4)
The diglycerin palmitate (WAX1) used in Example 1 was replaced with decaglycerin behenate (WAX10). Otherwise, the toner was obtained in the same manner as in Example 1.

(Comparative Example 5)
The diglycerin palmitate (WAX1) used in Example 1 was replaced with diglycerin behenate (WAX11). Otherwise, the toner was obtained in the same manner as in Example 1.

(Comparative Example 6)
Diglycerin palmitate (WAX1) used in Example 1 was replaced with hexaglycerin stearate (WAX12). Otherwise, the toner was obtained in the same manner as in Example 1.

(Comparative Example 7)
Diglycerin palmitate (WAX1) used in Example 1 was replaced with hexaglycerin behenate (WAX13). Otherwise, the toner was obtained in the same manner as in Example 1.

(Comparative Example 8)
The diglycerin palmitate (WAX1) used in Example 1 was replaced with decaglycerin stearate (WAX14). Otherwise, the toner was obtained in the same manner as in Example 1.

(Example 7)
By a conventional method of pulverized toner, a vinyl copolymer composed of 80% styrene component, 5% methyl methacrylate, 15% n-butyl acrylate, and 0.2% divinylbenzene as a crosslinking monomer was produced. 25 parts of this vinyl copolymer, 10 parts of diglycerin palmitate (WAX1), 60 parts of magnetite, 2 parts of polypropylene wax, 2 parts of carbon black and 1 part of an antistatic agent were pulverized and mixed with a ball mill. Thereafter, the mixture was melt-kneaded with a roll mill, cooled, coarsely pulverized, and finely pulverized with a jet mill to obtain a toner composition. Furthermore, 0.3 part of hydrophobic silica fine powder was added to this toner composition to prepare a pulverized toner.

(Example 8)
The diglycerin palmitate (WAX1) used in Example 7 was replaced with diglycerin stearate (WAX2). Except for this, a toner was obtained in the same manner as in Example 7.

Example 9
The diglycerin palmitate (WAX1) used in Example 7 was replaced with diglycerin behenate (WAX3). Except for this, a toner was obtained in the same manner as in Example 7.

(Example 10)
Diglycerin palmitate (WAX1) used in Example 7 was replaced with hexaglycerin behenate (WAX4). Except for this, a toner was obtained in the same manner as in Example 7.

(Example 11)
The diglycerin palmitate (WAX1) used in Example 7 was replaced with decaglycerin stearate (WAX5). Except for this, a toner was obtained in the same manner as in Example 7.

Example 12
Diglycerin palmitate (WAX1) used in Example 7 was replaced with decaglycerin behenate (WAX6). Except for this, a toner was obtained in the same manner as in Example 7.

(Comparative Example 9)
The diglycerin palmitate (WAX1) used in Example 7 was replaced with a purified diglycerin stearate (WAX7). Except for this, a toner was obtained in the same manner as in Example 7.

(Comparative Example 10)
The diglycerin palmitate (WAX1) used in Example 7 was replaced with a purified diglycerin behenate product (WAX8). Except for this, a toner was obtained in the same manner as in Example 7.

(Comparative Example 11)
The diglycerin palmitate (WAX1) used in Example 7 was replaced with diglycerin palmitate (WAX9). Except for this, a toner was obtained in the same manner as in Example 7.

(Comparative Example 12)
The diglycerin palmitate (WAX1) used in Example 7 was replaced with decaglycerin behenate (WAX10). Except for this, a toner was obtained in the same manner as in Example 7.

(Comparative Example 13)
The diglycerin palmitate (WAX1) used in Example 7 was replaced with diglycerin behenate (WAX11). Except for this, a toner was obtained in the same manner as in Example 7.

(Comparative Example 14)
Diglycerin palmitate (WAX1) used in Example 7 was replaced with hexaglycerin stearate (WAX12). Except for this, a toner was obtained in the same manner as in Example 7.

(Comparative Example 15)
Diglycerin palmitate (WAX1) used in Example 7 was replaced with hexaglycerin behenate (WAX13). Except for this, a toner was obtained in the same manner as in Example 7.

(Comparative Example 16)
The diglycerin palmitate (WAX1) used in Example 7 was replaced with decaglycerin stearate (WAX14). Except for this, a toner was obtained in the same manner as in Example 7.

(Test method)
In this example and comparative example, evaluation was performed by the following method, and the test results of the polymerization toner are shown in Table 2. Table 3 shows the test results of the pulverized toner.

(Wax dispersion state)
The toner particles were coated with metal and covered with an epoxy resin, and then an ultrathin section was prepared. Next, after dyeing with ruthenium tetroxide, the dispersion state of the wax with respect to the toner resin was observed using a TEM (transmission electron microscope). The results of measuring the dispersed particle diameter (μm) of the wax are shown in Table 2 and Table 3.

(Minimum fixing temperature, hot offset temperature)
A fixing test was conducted using a commercially available non-magnetic one-component developing type printer (eight sheets) modified so that the temperature of the fixing roll portion could be changed. The fixing test was performed by changing the temperature of the fixing roll of the modified printer, measuring the toner fixing rate at each temperature, and determining the relationship between the temperature and the fixing rate. The fixing rate was calculated from the ratio of the image density before and after the tape peeling operation in the black solid area of the test paper printed with the modified printer. That is, if the image density before tape peeling is before ID and the image density after tape peeling is after ID, the fixing rate can be calculated from the following equation.
Fixing rate (%) = (after ID / before ID) × 100
Here, the tape peeling operation is a series of operations in which an adhesive tape is applied to a measurement portion of a test paper, adhered at a constant pressure, and then peeled off in a direction along the paper at a constant speed. The image density was measured using a reflection type image density measuring device. In this fixing test, the fixing roll temperature at a fixing rate of 80% was evaluated as the minimum fixing temperature of the developer. The hot offset was measured up to a fixing roller temperature of 230 ° C. with the temperature at which printing smear due to hot offset could be confirmed on the printed paper as the hot offset temperature. The results are shown in Tables 2 and 3.

(Blocking resistance)
After the toner is put in a sealable container and sealed, the container is submerged in a constant temperature water bath maintained at a temperature of 55 ° C. After 8 hours, the container is taken out from the constant temperature water tank, and the toner in the container is transferred onto a 42 mesh sieve. At this time, the toner is gently taken out of the container and carefully transferred onto a sieve so as not to destroy the toner aggregation structure in the container. Then, using a powder measuring machine, after vibrating for 30 seconds under the condition of strength 4.5, the state of the toner remaining on the sieve was observed. The case where no aggregation (cake formation) was observed in the toner particles was indicated by ◯, the case where slight aggregation was observed was indicated by Δ, and the case where aggregation was observed was indicated by ×. The results are shown in Tables 2 and 3.

(Print durability)
400 g of toner is put in a toner cartridge, and the above-mentioned modified printer is used to perform continuous printing from the initial stage to 16,000 sheets in an environment of 23 ° C. and 50 RH%, and the print density measured by a reflective image density measuring machine is Durability of image printing with toner was determined by examining the number of continuous prints that can maintain an image quality of 15% or less with non-image area fogging measured by a whiteness meter (made by Nippon Denshoku Industries Co., Ltd.) at least Was tested. The results are shown in Tables 2 and 3.

(Print durability after leaving at high temperature)
400 g of toner is put in a toner cartridge, this cartridge is sealed with an aluminum bag, and then submerged in a constant temperature water tank maintained at a temperature of 50 ° C. After 5 days, the cartridge was taken out of the constant temperature water tank, and thereafter the printing durability was tested in the same manner as described above. The results are shown in Tables 2 and 3.

  It has been found that the toner added with the polyglycerin fatty acid ester of the present invention is excellent in low-temperature fixability, blocking resistance, and printing durability. Therefore, by blending a specific amount of the polyglycerin fatty acid ester of the present invention, a toner excellent in low-temperature fixability, blocking resistance and printing durability can be obtained, and image formation for high-speed printing requiring high image quality and high speed is required. It can be suitably used for an apparatus.

Claims (3)

  The constituent fatty acid is a polyglycerin fatty acid ester composed of a saturated fatty acid having 16 to 22 carbon atoms, wherein the polyglycerin fatty acid ester has a hydroxyl value of 12 to 30 mgKOH / g. Ester wax that improves blocking and printing durability.   A binder resin for toner containing the ester wax according to claim 1.   A toner using the binder resin according to claim 2.