JP2005316142A - Binder resin composition for pulverization toner and its manufacturing method, and pulverization toner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide toner having an excellent balance in low temperature fixing property and non-offset property, and to provide a binder resin and its manufacturing method to be used for the toner. <P>SOLUTION: The resin composition is a styrene-based binder resin composition for a pulverization toner, the composition containing 0.5 to 25 parts by mass of a fatty acid ester having 70 to 90°C melting point to 100 parts by mass of vinyl monomers. The styrene-based binder resin composition is obtained by polymerizing the vinyl monomers in the presence of the fatty acid ester, and is used as a binder resin composition of the toner. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a pulverized toner binder resin and a pulverized toner binder resin used for developing an electrostatic charge image or a magnetic latent image in electrophotography, electrostatic recording method, electrostatic printing method and the like, and pulverized toner. It is about.

  The image forming process by electrophotography and electrostatic printing is performed by (1) uniformly charging a photoconductive insulating layer, exposing the insulating layer, and dissipating the charge on the exposed portion. Development process for forming a latent image and making the latent image visible by attaching a finely charged toner to the latent image, (2) Transfer for transferring the obtained visible image onto a transfer material such as transfer paper And (3) a fixing step for permanent fixing by heating or pressing.

  As a toner used in such an electrophotographic method or electrostatic printing method, various performances are required in each of the above steps. For example, in copiers and printers, blocking resistance that prevents toner from blocking during storage is required. In the fixing process using the heat roller fixing method, non-offset property in which molten toner does not adhere to the heat roller, or toner paper is applied. Is required. In recent years, energy saving and speeding-up of copiers and printers have progressed, and toners are strongly desired to have fixing properties particularly at low temperatures. As a result, the level of blocking resistance that prevents toner from blocking during storage in copiers and printers has become even higher.

  Conventionally, a styrene-acrylic resin has been widely used as a binder resin for toner, and in order to improve low-temperature fixability, an attempt has been made to lower the melting point of the toner by improving the molecular weight and molecular weight distribution of the binder resin. Has been made. However, by using a low molecular weight binder resin, the purpose of lowering the melting point of the toner and improving the low-temperature fixability could be achieved, but at the same time, the melt viscosity was lowered, thereby allowing the heat fixing roller to be used. A new problem has arisen that the phenomenon of toner adhesion, that is, the so-called offset phenomenon occurs.

  In order to prevent this offset phenomenon, studies have been made to develop non-offset properties by incorporating a release agent into the toner (for example, see Patent Documents 1 and 2).

Patent Document 1 describes a toner obtained by blending (externally adding) a wax having a branched structure represented by the general formula C (CH ₂ COOR) ₄ during melt kneading. However, although the non-offset property is manifested by adding the wax, the wax dispersibility is poor in the externally added system. As a result, a problem of contamination in the copying machine occurs and the continuous operation stability is problematic. Further, the yield after finely pulverizing and classifying the toner was low, and a sufficient effect for improving the low-temperature fixability could not be obtained.

Patent Document 2 describes a styrene-based binder resin composition (added internally) obtained by copolymerizing a vinyl-based monomer in the presence of polypropylene wax. In the wax internal addition system, the dispersibility of the wax is good, but the polypropylene wax has a problem that the low-temperature fixability is poor.
JP 2001-92174 A Japanese Patent Laid-Open No. 10-123753

  An object of the present invention is to provide a toner having an excellent balance between low-temperature fixability and non-offset property, a binder resin used therefor, and a method for producing the same.

  The present invention relates to a styrene-based binder resin composition for pulverized toner containing 0.5 to 25 parts by mass of a fatty acid ester having a melting point of 70 to 90 ° C. and a branched structure with respect to 100 parts by mass of a vinyl polymer, and production thereof And a toner containing the styrenic binder resin composition.

  By using the binder resin composition for toner of the present invention, a toner having an excellent balance between low-temperature fixability and non-offset property can be provided.

  The binder resin composition of the present invention contains a fatty acid ester having a melting point of 70 to 90 ° C. and having a branched structure. By containing the fatty acid ester having a branched structure, the sharp melt property of the toner is improved, and when the melting point of the ester is 70 to 90 ° C., the low temperature fixability is improved.

  The fatty acid ester having a branched structure is an ester obtained by reacting a monovalent fatty acid and a trihydric or higher polyhydric alcohol.

Although it does not restrict | limit especially as a monovalent fatty acid, A C12-C24 fatty acid is preferable. The lower limit of the carbon number is more preferably 18 or more, and particularly preferably 20 or more. Further, the upper limit of the carbon number is particularly preferably 22 or less. Examples thereof include fatty acids such as lauric acid myristic acid, stearic acid, and behenic acid.
Although it does not restrict | limit especially as a polyhydric alcohol more than trivalence, A C3-C10 polyhydric alcohol is preferable. The lower limit of the carbon number is particularly preferably 4 or more. Further, the upper limit value of the carbon number is preferably 8 or less, and particularly preferably 6 or less. For example, polyhydric alcohols such as glycerin, trimethylolpropane, pentaerythritol, dipentaerythritol and the like can be mentioned.

  Among these fatty acid esters having a branched structure, trimethylolpropane fatty acid monoester, trimethylolpropane fatty acid diester, trimethylolpropane fatty acid full ester, pentaerythritol fatty acid monoester, pentaerythritol fatty acid diester, pentaerythritol fatty acid triester, pentaerythritol Fatty acid full esters are preferred from the viewpoint of melting point. Among these, pentaerythritol fatty acid monoester, pentaerythritol fatty acid diester, pentaerythritol fatty acid triester, pentaerythritol fatty acid full ester is more preferable, and pentaerythritol fatty acid full ester is particularly preferable.

  The melting point of the fatty acid ester having a branched structure is 70 to 90 ° C. When the melting point is 70 ° C. or higher, the toners are not fused with each other and the storage stability tends to be good, and when the melting point is 90 ° C. or lower, the low-temperature fixability tends to be developed. The lower limit of the melting point is preferably 75 ° C. or higher, and particularly preferably 80 ° C. or higher.

  The content of the fatty acid ester having a branched structure is not particularly limited, but is in the range of 0.5 to 25 parts by mass with respect to 100 parts by mass of the vinyl polymer. When this content is 0.5 parts by mass or more, the effect as a wax tends to be sufficiently manifested and the non-offset property tends to be good. There is a tendency that no omission occurs and contamination to the blade or the like does not occur. The lower limit of this content is preferably 1 part by mass or more, more preferably 2 parts by mass or more, further preferably 3 parts by mass or more, and particularly preferably 4 parts by mass or more. Moreover, the upper limit of this content is preferably 20 parts by mass or less.

  The vinyl polymer constituting the binder resin of the present invention is a polymer obtained by polymerizing a vinyl monomer.

  The vinyl monomer is not particularly limited, and styrene monomers, acrylate monomers, other vinyl monomers, and the like can be used.

  The styrene monomer is not particularly limited. For example, styrene, o-methyl styrene, m-methyl styrene, p-methyl styrene, α-methyl styrene, p-ethyl styrene, 2,4-dimethyl styrene, pn-butyl styrene, p-tert-butyl styrene, pn-hexyl styrene, pn-octyl styrene, pn-nonyl styrene, pn-tensyl styrene, pn-dodecyl styrene, p-phenyl styrene, 3, 4- Examples include dicyclosylstyrene, and among them, styrene is preferable. These styrenic monomers can be used alone or in combination of two or more.

  In addition, the acrylate ester monomer is not particularly limited, and examples thereof include ethyl acrylate, methyl acrylate, n-butyl acrylate, isobutyl acrylate, propyl acrylate, 2-ethylhexyl acrylate, and stearyl acrylate. , Unsaturated dicarboxylic esters such as methacrylic acid, ethyl methacrylate, methyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, propyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate Etc.

  Examples of other vinyl monomers include unsaturated monocarboxylic acids such as acrylic acid, methacrylic acid and cinnamic acid, unsaturated dicarboxylic acids such as maleic acid, fumaric acid and itaconic acid, monomethyl maleate, monoethyl maleate and maleic acid. Examples thereof include carboxylic acid-containing vinyl monomers such as unsaturated monocarboxylic acid monoesters such as monobutyl acid, monomethyl fumarate, monoethyl fumarate, and monobutyl fumarate.

  The content of these monomers is not particularly limited, but the styrene monomer is the main component, that is, the styrene monomer is 50% by mass or more in the total amount of the vinyl monomer. preferable. When the styrene monomer is 50% by mass or more, the fixability tends to be good. The content of the styrene monomer is more preferably 60% by mass or more, and particularly preferably 70% by mass or more.

  Further, the molecular weight distribution of the binder resin for toner of the present invention is not particularly limited, but is preferably 2 or more in the molecular weight distribution (Mw / Mn) by GPC measurement. This is because when the molecular weight distribution (Mw / Mn) is 2 or more, the low-temperature fixability and the non-offset property tend to be balanced.

  The softening temperature of the binder resin composition of the present invention is not particularly limited, but is preferably 100 ° C. to 200 ° C. in the softening temperature by flow tester measurement. When the softening temperature of the binder resin is 100 ° C. or lower, the non-offset property and the durability tend to decrease, and when it is 200 ° C. or higher, the binder resin is sufficient in the following cases. This is because the fixing performance cannot be obtained. Low temperature fixability tends to be good.

  The method for producing the binder resin composition of the present invention is not particularly limited, and can be produced by, for example, an emulsion polymerization method, a suspension polymerization method, a bulk polymerization method, a solution polymerization method, and the like. It can also be produced by mixing resins produced by legal methods.

  For example, in the case of the emulsion polymerization method, the binder resin composition particles can be obtained by coagulation method or spray drying method after emulsion polymerization by adding the above fatty acid ester having the above branched structure to the above vinyl monomer. it can.

  In addition, for example, in the case of suspension polymerization, binder resin composition particles can be obtained by adding the above-described vinyl monomer to the fatty acid ester having the above-mentioned branched structure and performing suspension polymerization, followed by filtration. it can.

  In the bulk polymerization method, binder resin composition particles can be obtained by bulk polymerization after the fatty acid ester having the branched structure described above is contained in the vinyl monomer and then pulverized.

  Further, for example, in the case of the solution polymerization method, the above-mentioned vinyl monomer may contain the fatty acid ester having the above-mentioned branched structure, solution-polymerized, and after removing the solvent, the binder resin composition particles may be obtained by pulverization. Then, after polymerizing the above vinyl monomer, the fatty acid ester having the above branched structure is dissolved in the polymer solution, and then the solvent may be removed and pulverized to obtain binder resin composition particles.

  Among these methods, from the viewpoint of achieving both fixing property and non-offset property, a method in which the above-mentioned vinyl monomer is polymerized by containing the fatty acid ester having the above-mentioned branched structure is preferable. This is because the fixability of the toner tends to be remarkably improved by polymerizing the vinyl monomer in the presence of a fatty acid ester having a branched structure. Further, from the viewpoint of the odor of the toner, it is preferable to produce the toner and the solvent remaining in the binder resin by a method that results in 500 ppm or less.

  In addition, the initiator used for the polymerization is not particularly limited, and a polymerization initiator such as an organic peroxide or an azo initiator can be used. Each of emulsion polymerization, suspension polymerization, bulk polymerization, and solution polymerization can be used. A polymerization initiator suitable for the polymerization method may be used.

Next, the pulverized toner of the present invention will be described.
The pulverized toner of the present invention contains the styrenic binder resin described above. The content of the styrenic binder resin is not particularly limited, but is preferably 35 to 95% by mass based on the total amount of toner. When this content is 35% by mass or more, fixability tends to be good, and when it is 95% by mass or less, non-offset property and color tone tend to be good. The lower limit of the content is more preferably 40% by mass or more, and the upper limit is more preferably 90% by mass or less.

  The pulverized toner of the present invention contains the above-mentioned styrenic binder resin composition, and if necessary, a colorant, a fluidity improver, a charge control agent, a magnetic substance, and the like are blended therein. Can do.

  As the colorant, commonly used carbon black, chromatic pigments and dyes can be used, and there is no particular limitation. In the case of color toner, for example, C.I. I. Solvent Yellow 21, C.I. I. Solvent Yellow 77, C.I. I. Solvent Yellow 114, C.I. I. Pigment yellow 12, C.I. I. Pigment yellow 14, C.I. I. Pigment yellow 17, C.I. I. Pigment yellow 83, C.I. I. Solvent Red 19, C.I. I. Solvent Red 49, C.I. I. Solvent Red 128, C.I. I. Pigment red 5, C.I. I. Pigment red 13, C.I. I. Pigment red 22, C.I. I. Pigment red 48.2, C.I. I. Disperse thread 11, C.I. I. Solvent Blue 25, C.I. I. Solvent Blue 94, C.I. I. Pigment blue 60, C.I. I. And CI Pigment Blue 15.3.

  The content of the colorant is not particularly limited, but is preferably in the range of 2 to 10% by mass in the total amount of toner from the viewpoint of toner color tone, image density, and thermal characteristics. The lower limit of this content is more preferably 3% by mass or more, and the upper limit is more preferably 8% by mass or less.

  The fluidity improver is not particularly limited. For example, silica, alumina, titanium oxide, barium titanate, magnesium titanate, calcium titanate strontium titanate, zinc oxide, silica sand, clay, mica, diatomaceous earth, Examples include cerium oxide, bengara, antimony trioxide, magnesium oxide, zirconium oxide, barium sulfate, barium carbonate, calcium carbonate, silicon carbide, and silicon nitride.

  The content of the fluidity improver is not particularly limited, but is preferably in the range of 0.1 to 5 parts by mass with respect to 100 parts by mass of the toner. When the content of the fluidity improver is 0.1 parts by mass or more, filming tends to be suppressed, and when it is 5 parts by mass or less, the fixability tends to be good. The lower limit of this content is more preferably 0.2 parts by mass or more, and the upper limit is more preferably 3 parts by mass or less.

  Moreover, there is no restriction | limiting in particular as a charge control agent, The charge control agent conventionally used for electrophotography can be used. Examples of the negatively chargeable charge control agent include Bontron S-31, Bontron S-32, Bontron S-34, and Bontron S-36 manufactured by Orient Chemical Co., and Eisenspiron Black TVH manufactured by Hodogaya Chemical Co., Ltd. Metal-containing azo dyes; Quaternary ammonium salts such as Copy Charge NX VP434 manufactured by Hoechst; copper phthalocyanine dyes and the like. Examples of positively chargeable charge control agents include imidazole derivatives such as PLZ-2001 and PLZ-8001 manufactured by Shikoku Kasei; triphenylmethane derivatives such as Copy Charge BLUE PR manufactured by Hoechst; manufactured by Orient Chemical Co., Ltd. Bontron P-51, Copy Charge PXVP435 manufactured by Hoechst, quaternary ammonium salts such as cetyltrimethylammonium bromide, and polyamine resins such as AFP-B manufactured by Orient Chemical. In the present invention, one or more of the above charge control agents can be used. Moreover, it is also possible to use a main charge control agent and a charge control agent having a reverse polarity.

  The content of these charge control agents is not particularly limited, but is preferably in the range of 0.1 to 5% by mass based on the total amount of toner. When the content of the charge control agent is 0.1% by mass or more, the charge amount of the toner tends to be a sufficient level, and when it is 5% by mass or less, the decrease in the charge amount due to aggregation tends to be suppressed. .

  The pulverized toner of the present invention can be used as any one of a magnetic one-component developer, a non-magnetic one-component developer, a magnetic two-component developer, and a non-magnetic two-component developer.

  When the pulverized toner of the present invention is used as a magnetic one-component developer, the toner contains a magnetic substance. Examples of magnetic materials include ferromagnetic alloys including iron, cobalt, nickel and the like including ferrite and magnetite; so-called Heusler containing manganese and copper such as manganese-copper-aluminum and manganese-copper-tin An alloy that does not contain a compound or a ferromagnetic element, such as an alloy, but exhibits ferromagnetism by appropriate heat treatment; chromium dioxide and the like.

  The content of these magnetic materials is not particularly limited, but is preferably in the range of 30 to 70% by mass based on the total amount of toner. When the content of the magnetic material is 30% by mass or more, the charge amount of the toner tends to be a sufficient level, and when it is 70% by mass or less, the toner fixability tends to be good. The lower limit of the content of the magnetic material is more preferably 40% by mass or more, and the upper limit is more preferably 60% by mass or less.

  When the pulverized toner of the present invention is used as a magnetic two-component developer or a non-magnetic two-component developer, it is used in combination with a carrier. As the carrier, a known material such as a magnetic substance such as iron powder, magnetite powder, or ferrite powder, a resin coating on the surface thereof, or a magnetic carrier can be used. As coating resins for resin coating carriers, generally known styrene resins, acrylic resins, styrene acrylic copolymer resins, silicone resins, modified silicone resins, fluorine resins, mixtures of these resins, etc. Can be used. The amount of the carrier to be used in combination is not particularly limited, but when the amount is 900 parts by mass or more with respect to 100 parts by mass of the toner, the charge amount of the toner tends to be a sufficient level, which is preferable.

Next, the manufacturing method of the pulverized toner of the present invention will be described.
The production method of the pulverized toner of the present invention is not particularly limited, and can be produced using a known method. For example, the above-described styrene binder resin for toner and, if desired, a colorant, a flow modifier, a charge control agent, and a magnetic material are mixed, and then melt-kneaded with a twin screw extruder or the like, coarsely pulverized, finely divided It can be manufactured by pulverizing and classifying and attaching inorganic particles to the toner surface as required. Further, in the above process, a treatment such as making the toner particles spherical after fine pulverization to classification may be performed.

Hereinafter, the present invention will be described in detail with reference to examples.
The softening temperature, the molecular weight distribution (GPC) of the tetrahydrofuran (THF) soluble component, and the fixing test were evaluated by the following methods.
(1) Softening temperature Using a flow tester having a nozzle of 1.0 mmφ × 10.00 mm (manufactured by Shimadzu Corporation, CFT-500) under the conditions of a load of 294 N (30 kgf) and a temperature increase rate of 3 ° C./min, 1 g The temperature was shown when 1/2 of the sample flowed out.

(2) GPC measurement of THF soluble part The weight average molecular weight of THF soluble part was measured using GPC (the Tosoh company make, HCL-8020). The sample used was a THF solution in which 0.4% by mass of resin was dissolved and filtered through a PTFE membrane (Mishori Disc H-25-5 manufactured by Tosoh Corporation), and the column was a TSKgel / GMH _XL column (Tosoh Corporation). (Made by company) The thing comprised from 3 was used. In addition, the calibration curve was obtained from F2000 / F700 / F288 / F128 / F80 / F40 / F20 / F2 / A1000 (standard polystyrene manufactured by Tosoh Corporation) and styrene monomer, and the molecular weight was determined in terms of polystyrene. The measurement temperature was 38 ° C. and the detector was RI.

(3) Fixing test (fixing rate)
An unfixed image obtained by a commercial copying machine PREMAGE 251 (manufactured by TOSHIBA) was evaluated using a fixing tester with variable roller temperature. Here, the fixed image obtained at a roller temperature of 150 ° C. and a process speed of 400 mm / sec was rubbed nine times with a sand eraser (JIS 512), and the image density before and after that was measured with a Macbeth densitometer to measure the fixing rate.
◎ (Very good): Fixing rate of 90% or more ○ (Good): Fixing rate of 75% or more and less than 90% △ (Not satisfying the use level): Fixing rate of 60% or more and less than 75% × (Not usable at all): Fixing rate Less than 60%

(Non-offset property)
Using the same copying machine as that for fixing rate measurement, an unfixed image was passed through a fixing tester immediately after passing an unfixed image under conditions of a roller temperature of 240 ° C. and a process speed of 400 mm / sec.
○ (Good): Not dirty at all △ (Slightly less than the use level): Part of the paper is soiled × (Below the use level): Stain on the paper is remarkable

Example 1
Fatty acid ester (pentaerythritol and full ester of fatty acid, 20 parts by mass of resin having a molecular weight maximum of 500,000 by GPC obtained by copolymerizing 15 parts by mass of styrene and 5 parts by mass of n-butyl acrylate and a branched structure. Melting point 82 ° C .: 1 part by weight of “WEP-5” manufactured by NOF Corporation and 100 parts by weight of xylene were charged into a flask and dissolved. The flask was replaced with nitrogen gas and then heated to the boiling point of xylene. While stirring under reflux of xylene, a mixture of 66 parts by mass of styrene, 14 parts by mass of n-butyl acrylate, and 3.2 parts by mass of benzoyl peroxide was added dropwise over 2 hours to perform solution polymerization. It was. After completion of the dropwise addition, the solution polymerization is terminated by maintaining for 1 hour while stirring under reflux of xylene, and includes a low molecular weight polymer having a molecular weight maximum of 10,000, and a binder resin for toner having a weight average molecular weight (Mw) of 150,000. A was obtained. Thereafter, xylene was removed under reduced pressure while raising the temperature in the flask to 180 ° C., and then cooled to room temperature and pulverized to obtain a binder resin for toner. Biaxial extrusion of 94.5 parts by weight of this binder resin, 5 parts by weight of carbon black ("# 40" manufactured by Mitsubishi Chemical Corporation), and 0.5 parts by weight of a charge control agent ("Bondron S-34" manufactured by Orient Chemical Co., Ltd.) The mixture was melt kneaded at 120 ° C. in a machine. Next, the toner particle diameter was pulverized to 13 μm or less with a jet mill pulverizer, and then the toner particle diameter was removed with a zigzag classifier to obtain pulverized toner A. The fixing performance of the obtained toner at 150 ° C. was good. The non-offset performance at 240 ° C. was good.

Example 2
The same method as in Example 1 except that the amount of fatty acid ester having a branched structure (full ester of pentaerythritol and fatty acid, melting point 82 ° C .: “WEP-5” manufactured by NOF Corporation) is changed to 5 parts by mass. Binder resin B for toner was obtained. Table 1 shows the evaluation results of the obtained binder resin A for toner. Toner B was obtained in the same manner as in Example 1 except that binder resin B was used as the binder resin. Table 2 shows the evaluation results of the obtained toner.

Example 3
The toner was prepared in the same manner as in Example 1 except that the amount of fatty acid ester having a branched structure (pentaerythritol and full ester of fatty acid, melting point 82 ° C. “WEP-5” manufactured by NOF Corporation) was changed to 10 parts by mass. Binder resin C was obtained. Table 1 shows the evaluation results of the obtained binder resin C for toner. Toner C was obtained in the same manner as in Example 1 except that binder resin C was used as the binder resin. Table 2 shows the evaluation results of the obtained toner C.

Example 4
The toner was prepared in the same manner as in Example 1, except that the amount of fatty acid ester having a branched structure (full ester of pentaerythritol and fatty acid, melting point 82 ° C. “WEP-5” manufactured by NOF Corporation) was changed to 20 parts by mass. Binder resin D was obtained. Table 1 shows the evaluation results of the obtained binder resin D for toner. Toner D was obtained in the same manner as in Example 1 except that binder resin D was used as the binder resin. Table 2 shows the evaluation results of the obtained toner.

Comparative Example 1
A binder resin E for toner is obtained in the same manner as in Example 1 except that a fatty acid ester having a branched structure (full ester of pentaerythritol and fatty acid, melting point 82 ° C. “WEP-5” manufactured by NOF Corporation) is not added. It was. Table 1 shows the evaluation results of the obtained binder resin E for toner. Toner E was obtained in the same manner as in Example 1 except that binder resin E was used as the binder. Table 2 shows the evaluation results of the obtained toner.

Comparative Example 2
A fatty acid ester having a branched structure (pentaerythritol and a full ester of fatty acid, melting point 82 ° C. “WEP-5” manufactured by Nippon Oil & Fats Co., Ltd.) is changed to polyethylene wax (Sanwax 151P, melting point 107 ° C. manufactured by Sanyo Chemical Co., Ltd.) A toner binder resin F was obtained in the same manner as in Example 2. Table 1 shows the evaluation results of the obtained binder resin F for toner. Toner F was obtained in the same manner as in Example 1 except that binder resin F was used as the binder resin. Table 2 shows the evaluation results of the obtained toner.

Comparative Example 3
Other than changing the fatty acid ester having a branched structure (full ester of pentaerythritol and fatty acid, melting point 82 ° C., “WEP-5” manufactured by NOF Corporation) to polypropylene wax (viscose 550P manufactured by Sanyo Chemical Co., Ltd., melting point 150 ° C.) A toner binder resin G was obtained in the same manner as in Example 2. Table 1 shows the evaluation results of the obtained binder resin G for toner. A toner G was obtained in the same manner as in Example 1 except that the binder resin was changed to the binder resin G. Table 2 shows the evaluation results of the obtained toner.

Comparative Example 4
Implemented except changing fatty acid ester having a branched structure (full ester of pentaerythritol and fatty acid, melting point 82 ° C .: “WEP-5” manufactured by NOF Corporation) to carnauba wax (manufactured by Toyo Petrolite Co., melting point 83 ° C.) In the same manner as in Example 2, a toner binder resin H was obtained. Table 1 shows the evaluation results of the obtained binder resin H for toner. Toner H was obtained in the same manner as in Example 1 except that binder resin H was used as the binder resin. Table 2 shows the evaluation results of the obtained toner.

Comparative Example 5
The same method as in Example 1, except that the amount of fatty acid ester having a branched structure (pentaerythritol and full ester of fatty acid, melting point 82 ° C .: “WEP-5” manufactured by NOF Corporation) is changed to 30 parts by mass. To obtain a binder resin I for toner. Table 1 shows the evaluation results of the obtained binder resin I for toner. Toner I was obtained in the same manner as in Example 1 except that binder resin I was used as the binder resin. Table 2 shows the evaluation results of the obtained toner.

Comparative Example 6
90 parts by mass of binder resin E synthesized in Comparative Example 1, 5 parts by mass of carbon black (“# 40” manufactured by Mitsubishi Chemical Corporation), 0.5 part by mass of charge control agent (“Bondron S-34” manufactured by Orient Chemical Co., Ltd.) A fatty acid ester having a branched structure (pentaerythritol and full ester of fatty acid, melting point 82 ° C., “WEP-5” manufactured by NOF Corporation) was melt-kneaded at 120 ° C. with a twin screw extruder. Next, the toner particle size was pulverized to 13 μm or less by a jet mill pulverizer, and then the toner particle size was removed by a zigzag classifier to obtain toner J. Although the non-offset performance at 240 ° C. of the obtained toner was good, the fixing performance at 150 ° C. was not at the use level.

Comparative Example 7
Other than changing fatty acid ester having a branched structure (full ester of pentaerythritol and fatty acid, melting point 82 ° C .: “WEP-5” manufactured by NOF Corporation) to polypropylene wax (viscose 550P, melting point 150 ° C. manufactured by Sanyo Chemical Co., Ltd.) Obtained a toner K in the same manner as in Comparative Example 6. Table 2 shows the evaluation results of the obtained toner. Although the non-offset performance at 240 ° C. of the obtained toner was good, the fixing performance at 150 ° C. was not at the use level.

In addition, the symbol described in Table 1 and Table 2 represents the following.
St: styrene n-BA: n-butyl acrylate BPO: benzoyl peroxide WEP-5: full ester of pentaerythritol and fatty acid, manufactured by NOF Corporation, trade name “WEP-5”
151P: Polyethylene wax, manufactured by Sanyo Chemical Industries, Ltd., trade name “Sun Wax 151P”
550P: Polypropylene wax, manufactured by Sanyo Chemical Industries, trade name “Viscose 550P”
Carnauba: Carnauba wax, manufactured by Toyo Petrolite Co., Ltd. # 40: Carbon black, manufactured by Mitsubishi Chemical Corporation, trade name “# 40”
S-34: Charge control agent, manufactured by Orient Chemical Co., Ltd., trade name “Bondron S-34”

Claims (3)

  A styrene binder resin composition for pulverized toner containing 0.5 to 25 parts by mass of a fatty acid ester having a melting point of 70 to 90 ° C. and a branched structure with respect to 100 parts by mass of a vinyl polymer.   Styrene binder resin for pulverized toner, characterized by containing 0.5 to 25 parts by mass of a fatty acid ester having a melting point of 70 to 90 ° C. and a branched structure with respect to 100 parts by mass of a vinyl monomer A method for producing the composition. A pulverized toner containing the styrenic binder resin composition according to claim 1 or the styrenic binder resin composition obtained by the production method according to claim 2.