JP2010217434A - Toner and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a toner which is excellent in low-temperature fixability and does not cause void abnormality image in a black solid image due to filming of the toner on a photoreceptor. <P>SOLUTION: The toner contains at least a binder resin and inorganic fine powder, the binder resin contains at least a crystalline polyester resin and an amorphous resin, the inorganic powder contains at least silicon carbide fine powder, a roundness of the silicon carbide fine powder is 0.94 to 0.96, and a number-average particle size is 0.5 to 1.5 μm. Successive centrifugal forces are actuated on uncharged toner on an image carrier at the prescribed number of revolutions in the direction vertical to attachment surface, and an average value F of the centrifugal forces at the number of revolutions before and after detachment of the toner is set to be an attachment force. A rate (F/D) of the average value F(nN) to the volume-average particle size D(μm) of detached toner is 0.06 to 0.20 nN/μm. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a toner, a two-component developer, and an image forming apparatus that have excellent low-temperature fixability and do not cause abnormal images due to toner filming on a photoreceptor.

  In recent years, there has been a general demand for higher speed and higher image quality in the electrophotographic imaging industry. In particular, the toner fixability, which is one of the factors that have an important influence on the image quality, deteriorates as the image forming speed, that is, the system speed of the image forming apparatus increases, so that both high speed and toner fixability are achieved. This is an issue.

The unfixed toner image on the paper is fixed by heat and pressure in the fixing device, and the toner image is fixed to the paper. However, when the system speed increases, the unfixed toner image on the paper cannot receive a sufficient amount of heat in the fixing device. In other words, the toner with poor fixing is peeled off from the paper.
It is conceivable to increase the fixing temperature in order to increase the system speed and not to deteriorate the fixing property. However, there are limitations in terms of various side effects due to the increase in the in-machine temperature, shortening of the life of fixing member consumption, and energy saving. It is not enough as a countermeasure for improvement. Therefore, particularly in an ultra-high speed machine, improvement in the fixing performance of the toner itself is required, and there is a need for a toner design that has high-speed image formation with a fixing device and good fixability even with a low heat quantity.

Various studies have been made to improve the fixing property of the toner.
For example, in order to improve the fixing performance of the toner itself, a method of controlling the thermal characteristics of the resin itself is known. However, lowering the Tg (glass transition temperature) of the resin will cause deterioration in heat-resistant storage stability and fixing strength, and if the softening outflow temperature (F _1/2 ) temperature decreases due to the lower molecular weight of the resin, hot offset will occur. And problems such as too high gloss (gloss controllability). For this reason, by controlling the thermal characteristics of the resin itself, it has not yet been possible to obtain a toner having excellent low-temperature fixability and excellent heat-resistant storage stability and offset resistance.

  In order to cope with such low-temperature fixing, attempts have been made to use polyester resins that are excellent in low-temperature fixing properties and relatively good in heat-resistant storage, instead of the conventionally used styrene-acrylic resins (for example, patent documents). 1-6: JP-A-60-90344, JP-A-64-15755, JP-A-2-82267, JP-A-3-229264, JP-A-3-41470, JP-A-11- No. 305486). Also, an attempt to add a specific non-olefinic crystalline polymer having a sharp melt property at a glass transition temperature in a binder for the purpose of improving low-temperature fixability (for example, Patent Document 7: JP-A-62-63940). However, it cannot be said that the molecular structure and molecular weight are optimized.

  There are also attempts to use crystalline polyester having sharp melt properties (Patent Document 8: Japanese Patent No. 2931899, Patent Document 9: Japanese Patent Laid-Open No. 2001-222138). The acid value and the hydroxyl value of the resin are as low as 5 or less and 20 or less, respectively, and since the affinity between paper and crystalline polyester is low, sufficient low-temperature fixability cannot be obtained. Also, in Patent Document 9, the molecular structure and molecular weight of the crystalline polyester are not optimized, and the release roller is not applied to the fixing roller while having an appropriate gloss, or the amount of oil applied is very small. Even with the fixing method, the toner has sufficient low-temperature fixing property and sufficient offset prevention property, and at the same time, it is not a toner excellent in toner storage stability, transferability, durability, charging stability against humidity, and pulverization property.

  Further, in the technique described in Patent Document 10 (Japanese Patent Application Laid-Open No. 2002-214833), an incompatible and island-like phase separation structure between a crystalline polyester resin and an amorphous polyester resin, or a difference in THF insolubles in the resin. By specifying the maximum peak temperature that appears on the endothermic side in the DSC curve measured by a scanning calorimeter, both the lower limit of fixability and storage stability are achieved. In the case of image print density, it has been found that it is not possible to obtain a quality that sufficiently clears the problems including, for example, a toner filming on the photoconductor and a blackout image being generated when a black solid image is output. .

The technique described in Patent Document 12 (Japanese Patent Application Laid-Open No. 2005-338814) describes a prescription system containing a large amount of crystalline polyester resin, although improvement in fixability in an ultrahigh-speed image forming system is recognized. The filming property of the toner on the photosensitive member remained inferior, and the reliability of the image quality was not sufficient.

  The present invention has been made in order to solve the problems in the image forming apparatus having the above ultra-high speed system speed, and has excellent low-temperature fixability and blackout abnormality in a black solid image due to toner filming on the photosensitive member. An object of the present invention is to provide a toner and an image forming apparatus that do not generate an image.

Moreover, this invention includes the following aspect.
(S1) “At least a developing step for visualizing the electrostatic latent image formed on the surface of the image carrier using a developer containing toner; and Alternatively, an image forming method including a transfer step of transferring onto a recording medium, a cleaning step of cleaning transfer residual toner remaining on the surface of the image carrier, and a fixing step of fixing a visible image on the recording medium,
The toner contains at least a binder resin and an inorganic fine powder, the binder resin contains at least a crystalline polyester resin and an amorphous resin, and the inorganic fine powder is at least a silicon carbide fine powder ( A) and the remaining inorganic and / or organic fine powder (B), the circularity of the silicon carbide fine powder is 0.94 to 0.96, and the number average particle diameter is 0.00. An image forming method characterized by being 5 to 1.5 μm ”;
(S2) “In the above (S1), the inorganic and / or organic fine powder (B) is selected from the group consisting of hydrophobic silica fine particles, hydrophobic titanium oxide fine particles, and resin fine particles. Described image forming method ";
(S3) “The toner has an average adhesion force (F) calculated as it is based on an average centrifugal force (F) when the unfixed toner is separated from the rotating image bearing surface by centrifugal separation and the volume average of the toner. The image according to (S1) or (S2), wherein the toner is a low adhesion toner having a ratio (F / D) to a particle size D (μm) of 0.06 to 0.20 nN / μm. Forming method ";
(Here, the “average toner adhesion force (F)” is obtained by applying a centrifugal force to the image bearing member to which the uncharged toner is adhered at a predetermined rotational speed, so that the adhesion surface (the bearing surface) is applied. The toner is released in the vertical direction, and each released toner at each rotational speed is collected on the surface of the image carrier facing the toner adhesion surface, and the average value of the centrifugal force at the rotational speed before and after the toner is released ( F) is calculated by the following formula (1), the centrifugal force (Fc) at each rotation speed f (rpm) of the centrifugal separation is calculated, and the arithmetic average value of Fc at the rotation speed before and after the toner detachment is calculated as the adhesion force of each toner. The average value F = 10 A of the toner adhesion force is obtained from the arithmetic logarithm A of the common logarithm regarding the adhesion force of all the measured toners, and the adhesion force (F) is obtained.

（ただし、ρ：トナーの真比重（ｋｇ／ｍ^３）、ｄ：トナーの粒径（ｍ）、ｒ：回転半径（ｍ）を表わす。）
（Ｓ４） 「前記炭化珪素の量（Ａ）に対する前記その余の外添微粒子の量（Ｂ）の比（Ｂ：Ａ）が（９０〜１０：１０〜９０）であることを特徴とする前記（Ｓ１）乃至（Ｓ３）のいずれかに記載の画像形成方法」；
（Ｓ５） 「少なくとも結着樹脂と、無機微粉末とを含有し、前記結着樹脂が少なくとも結晶性ポリエステル樹脂と、非晶質樹脂とを含有し、前記無機微粉末が少なくとも炭化珪素微粉末（Ａ）と、これより硬度の小さい無機及び/又は有機微粉末（Ｂ）とを含有するものであり、該炭化珪素微粉の円形度が０．９４〜０．９６であり、個数平均粒径が０．５〜１．５μｍであり、
少なくとも、像担持体表面に形成された静電潜像をトナーを含む現像剤を用いて可視像化する現像工程と、像担持体表面の可視像を被転写体及び／又は記録媒体上に転写する転写工程と、像担持体表面に残った転写残留トナーをクリーニングするクリーニング工程と、記録媒体上の可視像を定着させる定着工程を有する画像形成方法の用いられることを特徴とする静電潜像現像用トナー」；
（Ｓ６） 「前記（Ｓ５）に記載のトナーと、キャリアとを含むことを特徴とする二成分現像剤」；
（Ｓ７） 前記（Ｓ５）に記載のトナー又は前記（Ｓ６）に記載の現像剤を搭載していることを特徴とする画像形成装置。」
前記その余の微粒子（Ｂ）としては、微粒子（Ａ）より硬度の小さいものを好適に使用できる。

(Where ρ represents the true specific gravity of the toner (kg / m ³ ), d represents the particle size (m) of the toner, and r represents the radius of rotation (m).)
(S4) “The ratio (B: A) of the amount (B) of the additional external fine particles to the amount (A) of the silicon carbide is (90 to 10:10 to 90)” The image forming method according to any one of (S1) to (S3);
(S5) “At least a binder resin and an inorganic fine powder are contained, the binder resin contains at least a crystalline polyester resin and an amorphous resin, and the inorganic fine powder is at least a silicon carbide fine powder ( A) and inorganic and / or organic fine powder (B) having a lower hardness than this, the circularity of the silicon carbide fine powder is 0.94 to 0.96, and the number average particle diameter is 0.5 to 1.5 μm,
At least a developing step for visualizing the electrostatic latent image formed on the surface of the image carrier using a developer containing toner, and a visible image on the surface of the image carrier on the transfer medium and / or recording medium An image forming method comprising: a transfer step for transferring the toner image onto the surface of the image carrier; a cleaning step for cleaning residual toner remaining on the surface of the image carrier; and a fixing step for fixing the visible image on the recording medium. Toner for developing an electrostatic latent image ";
(S6) “Two-component developer comprising the toner according to (S5) and a carrier”;
(S7) An image forming apparatus comprising the toner according to (S5) or the developer according to (S6). "
As the remaining fine particles (B), those having a smaller hardness than the fine particles (A) can be preferably used.

  According to the present invention, the above-mentioned problems in an image forming apparatus with an ultra-high system speed are solved, and excellent low-temperature fixability and occurrence of an abnormal white-out image on a black solid image due to toner filming on the photoreceptor. Provided are a toner that does not occur, a developer, and an image forming apparatus using these.

Sectional drawing of an example of the image forming apparatus of this invention The X-ray-diffraction result of the crystalline polyester resin (by the synthesis example 1) in this invention. Example of X-ray diffraction result of toner of the present invention

Use of a crystalline polyester resin for the toner has an effect of improving low-temperature fixability. However, in a toner system using a crystalline polyester resin, a white-out problem occurs in a black solid image derived from filming in which the toner adheres to the photoreceptor in an ultra-high speed machine.
The filming problem is considered to be mainly caused by the crystalline polyester resin itself in the toner particles, and the mechanism is not clear. However, the crystalline polyester resin oozes out on the toner particle surface, and the oozing out causes the photoreceptor. It is estimated that filming occurs due to contamination.

In the present invention, by using the characteristic silicon carbide inorganic fine particles in combination with the characteristic toner base, the effect of clearing the filming problem is exhibited well. Conventionally, silicon carbide fine particles known under the trade name “Carborundum” generally have a high hardness (Mohs hardness of 13 or more, which is much higher than the Mohs hardness 9 of alumina grains frequently used as abrasives. As a commercial product, the particle size is 0.4 to 0.7 μm (as opposed to the particle size in the present invention, small) by laser diffraction, and the pressure (1 t / cm ³ ) bulk specific gravity is 1.6. The silicon carbide fine particles in the present invention are externally added to the toner particles, but are not embedded in the toner particles, but are separated from the toner particles and mixed in the toner particles. The filming effect is higher: the weaker the adhesion of the toner particles themselves (the lower the surface energy), the easier the silicon carbide particles are released from the toner particles when they are added, and they are mixed in the toner and developer. On photoconductor Remove the Irumingu toner material in the polishing effect, a mechanism that can be suppressed filming problem is estimated.

  One of the important characteristics of silicon carbide required is that the circularity of silicon carbide fine particles is 0.94 to 0.96. When the circularity is less than 0.94, the silicon carbide particles are angular and damage the photoconductor, and the life of the photoconductor is shortened and abnormal image problems are likely to occur. When the circularity exceeds 0.96, the silicon carbide fine particles are too round and the effect of polishing and removing the filming substance on the photoreceptor is inferior.

  Another important feature of silicon carbide that is required is that the number average particle diameter is 0.5 to 1.5 μm. When the number average particle diameter is less than 0.5 μm, the particles themselves are too small, and the effect of polishing and removing the filming substance is inferior. When the number average particle diameter exceeds 1.5 μm, it is good for filming, but the photoconductor is easily scratched, the photoconductor life is shortened, and an abnormal image is easily generated.

[Toner adhesion force (F)]
The required characteristic of toner particles is toner adhesion (F). The toner adhesion force (F) in the present invention is defined as follows.
That is, the toner adhesion force (F) in the present invention is determined when the unfixed toner on the image carrying surface is centrifuged at various rotational speeds for the convenience of practical use. From the centrifugal force (Fc), the average centrifugal force (F) calculated by the following equation (1) is directly used as the toner adhesion force (F).

  Specifically, uncharged toner adheres to a substrate on which a surface of the same quality as the image carrier is formed, and the toner receiving surface of the substrate is separated from the toner adhesion surface of the substrate via a spacer so as to face the surface. The mounted measurement cell is configured, and the measurement cell is mounted on the centrifugal separator so that the centrifugal force acts in the direction perpendicular to the toner adhesion surface, and then the receiving of the measurement cell after each set rotation while increasing the rotation speed. After replacing the substrate and centrifuging for all the set rotation speeds, the particle diameter d of each toner adhering is measured for a partial region of each receiving substrate, and the rotation speed f (rpm) before and after toner desorption is measured. ) Is calculated by the following formula (1), and the arithmetic average value of the centrifugal force (Fc) at the number of revolutions before and after the toner detachment is defined as the adhesive force of each toner. Common logarithm From surgery Average A, determined by the method for obtaining an average value F = 10A of toner adhesion.

（ただし、ρ：トナーの真比重（ｋｇ／ｍ^３）、ｄ：トナーの粒径（ｍ）、ｒ：回転半径（ｍ）を表わす。）

(Where ρ represents the true specific gravity of the toner (kg / m ³ ), d represents the particle size (m) of the toner, and r represents the radius of rotation (m).)

  As described above, in the present invention, when the average value (F) of the centrifugal force at the rotational speed before and after the toner is desorbed is the adhesion force (F) of the toner, the average value F (nN) and the desorption are calculated. It is important that the ratio (F / D) to the volume average particle diameter D (μm) of the toner is 0.06 to 0.20 nN / μm. When the F / D ratio is smaller than 0.06, the adhesive force is too small, and it is difficult to add external additives other than silicon carbide to the toner particles, and the fluidity and chargeability of the toner are not stabilized. When the F / D ratio is larger than 0.20, silicon carbide is fixed to the toner particles and is difficult to be released, so that the filming problem cannot be prevented.

  Such control of the amount of C-Pes on the toner particle surface and the amount of WAX is greatly affected by the compatibility between the crystalline polyester resin and the amorphous resin, the degree of recrystallization, and the like, and special manufacturing conditions are required. In the present invention, the knowledge of optimizing manufacturing conditions such as a kneading step, a pulverizing step, an additive mixing step, etc. by means of quality engineering has been found to control two parameters.

  For example, when the toner was left for a long time from kneading to pulverization, the C-Pes amount tended to increase. When the kneading temperature was lowered, the extrusion speed was lowered, and the cooling gap was narrowed, the values of the C-Pes amount and the WAX amount tended to decrease.

  By controlling the important parameters in the present invention within a preferable range based on the above special manufacturing means, it was possible to realize both low-temperature fixing property and filming property in the ultrahigh-speed image forming system.

As the polycondensation polyester resin constituting the toner binder of the present invention, a polyester resin (AX) (unmodified) which is a polycondensate of polyol and polycarboxylic acid, polyepoxide (C) is added to the unmodified polyester resin (AX). ) And the like, and modified polyester resin (AY) obtained by reacting. Unmodified polyester resin (AX), modified polyester resin (AY) and the like may be used alone or in combination of two or more.
Examples of the polyol include a diol (g) and a trivalent or higher polyol (h), and examples of the polycarboxylic acid include a dicarboxylic acid (i) and a trivalent or higher polycarboxylic acid (j). You may use together.
Examples of the unmodified polyester resin (AX) and the modified polyester resin (AY) include the following, and these can also be used in combination.

Unmodified polyester resin (AX1): A linear polyester resin using (g) and (i).
Modified polyester resin (AX2): A non-linear polyester resin using a trivalent or higher polyol (h) and / or a trivalent or higher polycarboxylic acid (j) together with a diol (g) and a dicarboxylic acid (i).
Modified polyester resin (AY1): A modified polyester resin obtained by further reacting the modified polyester resin (AX2) with a polyepoxide (c).

  As the diol (g), those having a hydroxyl value of 180 to 1900 (mg KOH / g, the same applies hereinafter) are preferable. Specifically, alkylene glycol having 2 to 36 carbon atoms (ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butylene glycol, 1,6-hexanediol, etc.); 4 to 36 alkylene ether glycols (such as diethylene glycol, triethylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, and polypropylene glycol); alicyclic diols having 6 to 36 carbon atoms (1,4-cyclohexanedimethanol and hydrogen) Bisphenol A and the like); alkylene oxides having 2 to 4 carbon atoms of the above alicyclic diol [ethylene oxide (hereinafter abbreviated as EO), propylene oxide (hereinafter abbreviated as PO) and butylene oxide (hereinafter referred to as BO) Adducts (addition mole number 1-30); adducts (additions) of bisphenols (bisphenol A, bisphenol F, bisphenol S, etc.) having 2 to 4 carbon atoms alkylene oxides (EO, PO, BO, etc.) Mole number 2-30) etc. are mentioned.

Among these, preferred are alkylene glycols having 2 to 12 carbon atoms, alkylene oxide adducts of bisphenols, and combinations thereof. Particularly preferred are alkylene oxide adducts of bisphenols, alkylene glycols having 2 to 4 carbon atoms. And a combination of two or more of these.
In the above and below, the hydroxyl value and the acid value are measured by the method defined in JIS K 0070.

As the trivalent or higher (3 to 8 or higher) polyol (h), those having a hydroxyl value of 150 to 1900 are preferable. Specifically, an aliphatic polyhydric alcohol having 3 to 36 or more carbon atoms having 3 to 8 or more carbon atoms (an alkane polyol and an intramolecular or intermolecular dehydrate thereof such as glycerin, triethylolethane, trimethylolpro / te , Pentaerythritol, sorbitol, sorbitan, polyglycerin, and dipentaerythritol; saccharides and derivatives thereof such as sucrose and methylglucoside; and the like; alkylene oxides having 2 to 4 carbon atoms of the above aliphatic polyhydric alcohols (EO, PO) And BO)) adduct (addition mole number 1-30); trisphenol (trisphenol PA etc.) alkylene oxide (EO, PO, BO etc.) adduct (addition mole number 2-30). ); Novolac resin (phenol novolac and cresol novo) Click like: average polymerization degree of 3 to 60 alkylene oxide (EO 2-4 carbon atoms), PO, BO, etc.) adducts (added mole number 2 to 30) are exemplified.
Among these, preferred are 3 to 8 or higher aliphatic polyhydric alcohols and alkylene oxide adducts of novolac resins (addition mole number: 2 to 30), and particularly preferred are alkylene oxide adducts of novolak resins. It is.

  As the dicarboxylic acid (i), those having an acid value of 180 to 1250 (mg KOH / g, the same applies hereinafter) are preferable. Specifically, alkane dicarboxylic acids having 4 to 36 carbon atoms (such as succinic acid, adipic acid, and sebacic acid) and alkenyl succinic acids (such as dodecenyl succinic acid); alicyclic dicarboxylic acids having 4 to 36 carbon atoms [dimer acid] (Dimerized linoleic acid) etc.]; C4-C36 alkene dicarboxylic acid (maleic acid, fumaric acid, citraconic acid, mesaconic acid, etc.); C8-36 aromatic dicarboxylic acid (phthalic acid, isophthalic acid) , Terephthalic acid, and naphthalenedicarboxylic acid). Of these, preferred are alkene dicarboxylic acids having 4 to 20 carbon atoms and aromatic dicarboxylic acids having 8 to 20 carbon atoms. As (i), acid anhydrides or lower alkyl (carbon number 1 to 4) esters (methyl ester, ethyl ester, isopropyl ester, etc.) described above may be used.

  The trivalent or higher (3 to 6 or higher) polycarboxylic acid (j) preferably has an acid value of 150 to 1250 mg. Specifically, an aromatic polycarboxylic acid having 9 to 20 carbon atoms (trimellitic acid, pyromellitic acid, etc.); vinyl polymer of unsaturated carboxylic acid [number average molecular weight (hereinafter referred to as Mn, gel permeation chromatography) (By GPC): 450-10000] (styrene / maleic acid copolymer, styrene / acrylic acid copolymer, α-olefin / maleic acid copolymer, styrene / fumaric acid copolymer, etc.), and the like. . Among these, preferred are aromatic polycarboxylic acids having 9 to 20 carbon atoms, and particularly preferred are trimellitic acid and pyromellitic acid. As the trivalent or higher polycarboxylic acid (j), acid anhydrides or lower alkyl (1 to 4 carbon atoms) esters (methyl ester, ethyl ester, isopropyl ester, etc.) described above may be used.

Further, together with the above (g), (h), (i) and (j), an aliphatic or aromatic hydroxycarboxylic acid (k) having 4 to 20 carbon atoms and a lactone (l) having 6 to 12 carbon atoms are copolymerized. You can also
Examples of the hydroxycarboxylic acid (k) include hydroxystearic acid and hydrogenated castor oil fatty acid. Examples of the lactone (l) include caprolactone.

  Examples of the polyepoxide (c) include polyglycidyl ether [ethylene glycol diglycidyl ether, tetramethylene glycol diglycidyl ether, bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, glycerin triglycidyl ether, pentaerythritol tetraglycidyl ether, phenol novolac ( Average polymerization degree 3 to 60) glycidyl etherified compound, etc.]; diene oxide (pentadiene dioxide, hexadiene dioxide, etc.) and the like. Among these, polyglycidyl ether is preferable, and ethylene glycol diglycidyl ether and bisphenol A diglycidyl ether are more preferable.

The number of epoxy groups per molecule of the polyepoxide (c) is preferably 2 to 8, more preferably 2 to 6, and particularly preferably 2 to 4.
The epoxy equivalent of the polyepoxide (c) is preferably 50 to 500. The lower limit is more preferably 70, particularly preferably 80, and the upper limit is more preferably 300, particularly preferably 200. When the number of epoxy groups and the epoxy equivalent are within the above ranges, both developability and fixability are good. It is more preferable if the above-mentioned ranges of the number of epoxy groups per molecule and the epoxy equivalent are satisfied at the same time.

  The reaction ratio of the polyol and the polycarboxylic acid is preferably 2/1 to 1/2, more preferably 1.5 / 1, as an equivalent ratio [OH] / [COOH] of the hydroxyl group [OH] and the carboxyl group [COOH]. ˜1 / 1.3, particularly preferably 1.3 / 1 to 1 / 1.2. The types of polyol and polycarboxylic acid to be used are selected in consideration of molecular weight adjustment so that the glass transition point of the polyester toner binder to be finally adjusted is 45 to 85 ° C.

  In the present invention, the amorphous polyester resin used as the toner binder can be produced in the same manner as in the usual polyester production method. For example, the reaction temperature is preferably 150 to 280 ° C, more preferably 160 to 250 ° C, particularly preferably 170 to 240 ° C in the presence of a titanium-containing catalyst (a) in an inert gas (nitrogen gas or the like) atmosphere. It can be performed by reacting. The reaction time is preferably 30 minutes or longer, particularly 2 to 40 hours from the viewpoint of reliably performing the polycondensation reaction. It is also effective to reduce the pressure (for example, 1 to 50 mmHg) in order to improve the reaction rate at the end of the reaction.

The addition amount of the titanium-containing catalyst (a) is preferably 0.0001 to 0.8%, more preferably 0.0002 to 0.6 based on the weight of the polymer obtained from the viewpoint of polymerization activity and the like. %, Particularly preferably 0.0015 to 0.55%.
Moreover, another esterification catalyst can also be used together in the range which does not impair the catalytic effect of a titanium containing catalyst (a). Examples of other esterification catalysts include tin-containing catalysts (eg, dibutyltin oxide), antimony trioxide, titanium-containing catalysts other than titanium-containing catalyst (a) (other than titanium complex catalysts) (eg, titanium alkoxide, potassium titanyl oxalate, And titanium terephthalate), zirconium-containing catalysts (eg zirconyl acetate), germanium-containing catalysts, alkali (earth) metal catalysts (eg alkali metal or alkaline earth metal carboxylates: lithium acetate, sodium acetate, potassium acetate, acetic acid) Calcium, sodium benzoate, potassium benzoate and the like), zinc acetate and the like. The addition amount of these other butterflies is preferably 0 to 0.6% based on the weight of the polymer obtained. By making it within 0.6%, the coloration of the polyester resin is reduced, which is preferable for use in color toners. The content of the titanium-containing catalyst (a) in all the added catalysts is preferably 50 to 100%.

  As a method for producing the linear polyester resin (AX1), for example, 0.0001 to 0.8% of butterfly (a) with respect to the weight of the obtained polymer, and optionally in the presence of another catalyst, Examples include a method in which the diol (g) and the dicarboxylic acid (i) are heated to 180 ° C. to 260 ° C. and subjected to dehydration condensation under normal pressure and / or reduced pressure conditions to obtain (AX1).

  As a method for producing the non-linear polyester resin (AX2), for example, 0.0001 to 0.8% of a titanium-containing catalyst (a) with respect to the weight of the obtained polymer and, if necessary, the presence of another catalyst The diol (g), the dicarboxylic acid (i), and the trihydric or higher polyol (h) are heated to 180 ° C. to 260 ° C. and dehydrated and condensed under normal pressure and / or reduced pressure conditions, and then further trivalent. A method of reacting the above polycarboxylic acid (j) to obtain (AX2) can be mentioned. (J) can also be reacted simultaneously with (g), (i) and (h).

As a method for producing the modified polyester resin (AY1), a polyepoxide (c) is added to the non-linear polyester resin (AX2), and a molecular extension reaction of the polyester is performed at 180 ° C. to 260 ° C. to obtain (AY1). Is mentioned.
The acid value of the non-linear polyester resin (AX2) to be reacted with the polyepoxide (c) is preferably 1 to 60, more preferably 5 to 50. When the acid value is 1 or more, the polyepoxide (c) remains unreacted and does not adversely affect the performance of the resin, and when it is 60 or less, the thermal stability of the resin is good.
The amount of the polyepoxide (c) used for obtaining the modified polyester resin (AY1) is preferably 0.01 with respect to the non-linear polyester resin (AX2) from the viewpoint of low-temperature fixability and hot offset resistance. -10%, more preferably 0.05-5%.

In addition to the above polycondensed polyester resin, the resin binder of the present invention may contain other resins as required.
Other resins include styrene resins (such as copolymers of styrene and alkyl (meth) acrylate, copolymers of styrene and diene monomers), epoxy resins (such as bisphenol A diglycidyl ether ring-opening polymer), Examples thereof include urethane resins (diols and / or polyaddition products of trivalent or higher polyols and diisocyanates, etc.).
The content of the other resin in the toner binder is preferably 0 to 40% by weight, more preferably 0 to 30% by weight, and particularly preferably 0 to 20% by weight.

(Crystalline polyester A)
The crystalline polyester resin (A) used in the present invention comprises a crystalline aliphatic polyester resin containing at least 60 mol% of an ester bond represented by the following general formula (1) in its molecular main chain. And

(In the general formula (1), R represents a linear unsaturated aliphatic divalent carboxylic acid residue, and is a linear unsaturated aliphatic group having 2 to 20 carbon atoms, preferably 2 to 4 carbon atoms. n is an integer of 2 to 20, preferably 2 to 6.)
The presence of the structure of the general formula (1) can be confirmed by solid C ¹³ NMR.
Specific examples of the linear unsaturated aliphatic group include linear unsaturated divalent carboxylic acids such as maleic acid, fumaric acid, 1,3-n-propene dicarboxylic acid, and 1,4-n-butene dicarboxylic acid. Mention may be made of linear unsaturated aliphatic groups derived from acids.

In the general formula (1), (CH ₂ ) n represents a linear aliphatic dihydric alcohol residue. Specific examples of the linear aliphatic dihydric alcohol residue in this case include linear aliphatic 2 such as ethylene glycol, 1,3-propylene glycol, 1,4-butanediol, and 1,6-hexanediol. Those derived from dihydric alcohols can be indicated. Since the polyester resin (A) uses a linear unsaturated aliphatic dicarboxylic acid as the acid component, the polyester resin (A) exhibits an effect that a crystal structure is easily formed as compared with the case where an aromatic dicarboxylic acid is used.

The polyester resin (A) is a polyvalent carboxylic acid comprising (i) a linear unsaturated aliphatic divalent carboxylic acid or a reactive derivative thereof (an acid anhydride, a lower alkyl ester having 1 to 4 carbon atoms, an acid halide, etc.). It can be produced by subjecting an acid component and a polyhydric alcohol component comprising (ii) a linear aliphatic diol to a polycondensation reaction by a conventional method.
In this case, a small amount of other polyvalent carboxylic acid can be added to the polyvalent carboxylic acid component as necessary. In this case, the polyvalent carboxylic acid includes (ia) an unsaturated aliphatic divalent carboxylic acid having a branched chain, (ib) a saturated aliphatic divalent carboxylic acid, a saturated aliphatic trivalent carboxylic acid, and the like. In addition to polyvalent carboxylic acids, (ic) aromatic polyvalent carboxylic acids such as aromatic divalent carboxylic acids and aromatic trivalent carboxylic acids are included. The addition amount of these polyvalent carboxylic acids is usually 30 mol% or less, preferably 10 mol% or less, based on the total carboxylic acid, and is appropriately added within the range where the resulting polyester has crystallinity.

  Specific examples of polyvalent carboxylic acids that can be added as needed include malonic acid, succinic acid, glutaric acid, adipic acid, suberic acid, sebacic acid, citraconic acid, phthalic acid, isophthalic acid, terephthalic acid, etc. A divalent carboxylic acid of: trimetic anhydride, 1,2,4-benzenetricarboxylic acid, 1,2,5-benzenetricarboxylic acid, 1,2,4-cyclohexanetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid, And trivalent or higher polyvalent carboxylic acids such as 1,2,5-hexanetricarboxylic acid, 1,3-dicarboxyl-2-methylenecarboxypropane, 1,2,7,8-octanetetracarboxylic acid, etc. it can.

A trivalent or higher polyhydric alcohol can be added to the polyhydric alcohol component (ii), if necessary, in addition to a small amount of an aliphatic branched dihydric alcohol or cyclic dihydric alcohol. The addition amount is 30 mol% or less, preferably 10 mol% or less, based on the total alcohol, and is appropriately added within the range in which the resulting polyester has crystallinity.
Examples of polyhydric alcohol added as needed include 1,4-bis (hydroxymethyl) cyclohexane, polyethylene glycol, bisphenol A ethylene oxide adduct, bisphenol A propylene oxide adduct, glycerin and the like.

In the polyester resin (A), the molecular weight distribution is preferably sharp from the viewpoint of low-temperature fixability, and the molecular weight is preferably a relatively low molecular weight. As for the molecular weight of the polyester resin (A), the weight average molecular weight (Mw) is 5500-6500, the number average molecular weight (Mn) is 1300-1500 and The Mw / Mn ratio is preferably 2-5.
The molecular weight distribution of the polyester resin (A) is based on a molecular weight distribution diagram in which the horizontal axis is log (M: molecular weight) and the vertical axis is weight%. In the case of the polyester resin (A) used in the present invention, in this molecular weight distribution diagram, it is preferable to have a molecular weight peak in the range of 3.5 to 4.0 (wt%), and the half width of the peak is 1. 5 or less is preferable.

In the polyester resin (A), the glass transition temperature (Tg) and softening temperature [T (F _1/2)] is desirably low to the extent that the heat-resistant storage stability of the toner is not deteriorated, in general, the Tg is 80 to 130 ° C., preferably 80 to 125 ° C., and T (F _1/2 ) is 80 to 130 ° C., preferably 80 to 125 ° C. When Tg and T (F _1/2 ) are higher than the above ranges, the lower limit fixing temperature of the toner is increased, so that the low temperature fixing property of the toner is deteriorated.

Whether or not the polyester resin in the present invention has crystallinity can be confirmed by whether or not there is a peak in the X-ray diffraction pattern by the powder X-ray diffractometer. The polyester resin (A) having crystallinity used in the present invention has at least one diffraction peak in the position where the Bragg angle 2θ is 20 ° to 25 ° in the diffraction pattern, and preferably the 2θ is at least It is characterized in that diffraction peaks exist at positions (i) 19 ° to 21 °, (ii) 21 ° to 23 °, (iii) 23 ° to 25 °, and (iv) 25 ° to 28 °.
The powder X-ray diffraction measurement was performed using a Rigaku Electric RINT1100, using a wide-angle goniometer with a tube of Cu and a tube voltage-current of 50 kV-30 mA (FIG. 2: the crystalline polyester resin of Synthesis Example 1). X-ray diffraction results, FIG. 3: An example of X-ray diffraction results of the toner of the present invention).

When two or more kinds of polyester resins are used in combination, and when at least one kind of polyester resin and another resin are mixed, powder mixing or melt mixing may be performed in advance, or they may be mixed at the time of toner formation. The temperature at the time of melt mixing is preferably 80 to 180 ° C, more preferably 100 to 170 ° C, and particularly preferably 120 to 160 ° C.
If the mixing temperature is too low, sufficient mixing cannot be achieved, which may result in non-uniformity. When two or more kinds of polyester resins are mixed, if the mixing temperature is too high, averaging due to transesterification occurs, so that the resin physical properties necessary as a toner binder may not be maintained.

The mixing time in the case of melt mixing is preferably 10 seconds to 30 minutes, more preferably 20 seconds to 10 minutes, and particularly preferably 30 seconds to 5 minutes. When two or more kinds of polyester resins are mixed, if the mixing time is too long, averaging due to the transesterification occurs as described above, so that the resin physical properties required as a toner binder may not be maintained.
Examples of the mixing device in the case of melt mixing include a batch type mixing device such as a reaction tank and a continuous mixing device. In order to mix uniformly in a short time at an appropriate temperature, a continuous mixer is preferable. Examples of the continuous mixing device include an extruder, a continuous kneader, and a three roll. Of these, extruders and container kneaders are preferred.
In the case of powder mixing, it can be mixed with normal mixing conditions and mixing equipment.
As mixing conditions in the case of powder mixing, the mixing temperature is preferably 0 to 80 ° C, more preferably 10 to 60 ° C. The mixing time is preferably 3 minutes or more, more preferably 5 to 60 minutes. Examples of the mixing device include a Henschel mixer, a Nauter mixer, and a bumper mixer. A Henschel mixer is preferred.

  The acid value of the crystalline polyester resin (A) is preferably 20 mgKOH / g or more in order to achieve the desired low-temperature fixability from the viewpoint of the affinity between paper and resin. On the other hand, in order to improve hot offset property, it is preferable that it is 45 mgKOH / g or less.

  Further, the hydroxyl value of the crystalline polyester resin (A) is preferably 5 to 50 mgKOH / g in order to achieve a predetermined low-temperature fixability and good charging characteristics.

It was confirmed that the fixing is remarkably improved by containing a fatty acid amide compound in the toner of the present invention. Although the principle is not clear, the silicone oil applied to the fixing roll during fixing is transferred to the image surface, and the nucleating agent prevents the oil from penetrating the image, resulting in the oil remaining on the image surface for a long time. Is presumed to have. If the oil is on the surface of the fixed image for a long time, it will be resistant to rubbing and the like, and the image fixing property immediately after fixing is at the best level.
Since there is a need for improvement in fixability immediately after fixing, for business environments in which a system with a linear speed of 500 to 1700 mm / sec, which is an object of the present invention, is frequently used, especially for users using roll paper, fatty acid is required. There is a need for the combined effect of amide compounds.

As the fatty acid amide ^compound, a compound represented by ^R 1 ^-CO-NR 2 R ³ is applied. In the formula, R ₁ is an aliphatic hydrocarbon group having 10 to 30 carbon atoms, and R ₂ and R ₃ are each independently a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, and an aryl group having 6 to 10 carbon atoms. Or an aralkyl group having 7 to 10 carbon atoms. Here, the alkyl group, aryl group, and aralkyl group of R ₂ and R ₃ may be substituted with a generally inactive substituent such as a fluorine atom, a chlorine atom, a cyano group, an alkoxy group, or an alkylthio group. However, it is more preferably unsubstituted.
Examples of preferred compounds include bis stearamide, stearic acid methylamide, stearic acid diethylamide, stearic acid benzylamide, stearic acid phenylamide, behenic acid amide, behenic acid dimethylamide, myristic acid amide, palmitic acid amide and the like.
In the present invention, among the fatty acid amide compounds, alkylene bis fatty acid amides are particularly preferably used. The alkylene bis fatty acid amide is a compound represented by the following general formula (II).

(Wherein R ₁ and R ₃ represent an alkyl group or alkenyl group having 5 to 21 carbon atoms, and R ₂ represents an alkylene group having 1 to 20 carbon atoms.)

Examples of the alkylene bis saturated fatty acid amide represented by the general formula (II) include methylene bis stearic acid amide, ethylene bis stearic acid amide, methylene bis palmitic acid amide, ethylene bis palmitic acid amide, methylene bis behenic acid amide, ethylene bis Examples thereof include behenic acid amide, hexamethylene bisstearic acid amide, hexaethylene bispalmitic acid amide, and hexamethylene bisbehenic acid amide. Of these, ethylene bis stearamide is most preferred.
These fatty acid amide compound, a softening point Tm (Tsp) is at lower than the surface temperature T _H during use of the fixing member, a fixing member surface, can serve effectively as a release agent.

  Specific examples of alkylene bis fatty acid amide compounds that can be used in addition to the above include propylene bis stearic acid amide, butylene bis stearic acid amide, methylene bis oleic acid amide, ethylene bis oleic acid amide, propylene bis oleic acid amide, Butylene bis oleic acid amide, methylene bis lauric acid amide, ethylene bis lauric acid amide, propylene bis lauric acid amide, butylene bis lauric acid amide, methylene bis myristic acid amide, ethylene bis myristic acid amide, propylene bis myristic acid amide, butylene bis Myristic acid amide, Propylene bispalmitic acid amide, Butylene bispalmitic acid amide, Methylene bispalmitoleic acid amide, Ethylene bispalmitoleic acid amide, Propylene vinyl Palmitoleic acid amide, butylene bispalmitoleic acid amide, methylene bisarachidic acid amide, ethylene bisarachidic acid amide, propylene bisarachidic acid amide, butylene bisarachidic acid amide, methylene biseicosenoic acid amide, ethylene biseicosenoic acid Amide, Propylene biseicosenoic acid amide, Butylene biseicosenoic acid amide, Methylene bis behenic acid amide, Ethylene bis behenic acid amide, Propylene bis behenic acid amide, Butylene bis behenic acid amide, Methylene bis Mention may be made of alkylene bis fatty acid amide compounds of saturated or monovalent unsaturated fatty acids such as erucic acid amide, ethylene biserucic acid amide, propylene biserucic acid amide, butylene biserucic acid amide.

  Moreover, you may use the wax as a mold release agent, and it is preferable that melting | fusing point of a wax is 70-150 degreeC. When the temperature is lower than 70 ° C., the heat resistant storage stability of the toner is poor. When it is higher than 150 ° C., there is a possibility that the releasability cannot be sufficiently achieved.

  As the wax, conventionally known waxes can be used. For example, low molecular weight polyethylene wax, low molecular weight polyolefin wax such as polypropylene, synthetic hydrocarbon wax such as Fischer-Tropsch wax, natural wax such as beeswax, carnauba wax, candelilla wax, rice wax, montan wax, Examples include petroleum waxes such as paraffin wax and microcrystalline wax, higher fatty acids such as stearic acid, palmitic acid, and myristic acid, metal salts of higher fatty acids, higher fatty acid amides, synthetic ester waxes, and various modified waxes thereof.

Of these, carnauba wax and its modified wax, polyethylene wax, and synthetic ester wax are preferably used. In particular, the synthetic ester wax pentaerythritol tetrabehenate is most preferred. The reason for this is that carnauba wax and its modified wax and synthetic ester wax are appropriately finely dispersed with respect to the polyester resin and polyol resin, so that the toner has excellent offset prevention, transferability and durability as described later. This is because it is easy.
These waxes can be used alone or in combination of two or more. The amount of these release agents used is preferably 2 to 15% by weight based on the toner. If it is less than 2% by weight, the effect of preventing offset is insufficient, and if it exceeds 15% by weight, transferability and durability are deteriorated.

As the colorant, known pigments and dyes capable of obtaining yellow, magenta, cyan, and black toners can be used.
For example, the yellow pigments include cadmium yellow, pigment yellow 155, benzimidazolone, mineral fast yellow, nickel titanium yellow, navel yellow, naphthol yellow S, Hansa yellow G, Hansa yellow 10G, benzidine yellow GR, quinoline yellow lake, Permanent yellow NCG, tartrazine lake and the like can be mentioned.

  Examples of the orange pigment include molybdenum orange, permanent orange GTR, pyrazolone orange, Vulcan orange, indanthrene brilliant orange RK, benzidine orange G, indanthrene brilliant orange GK and the like.

  Examples of red pigments include Bengala, Quinacridone Red, Cadmium Red, Permanent Red 4R, Risor Red, Pyrazolone Red, Watching Red Calcium Salt, Lake Red D, Brilliant Carmine 6B, Eosin Lake, Rhodamine Lake B, Alizarin Lake, Brilliant Carmine 3B, etc. Is mentioned.

Examples of purple pigments include fast violet B and methyl violet lake.
Examples of blue pigments include cobalt blue, alkali blue, Victoria blue lake, phthalocyanine blue, metal-free phthalocyanine blue, phthalocyanine blue partially chlorinated, first sky blue, and indanthrene blue BC.

Examples of the green pigment include chrome green, chromium oxide, pigment green B, and malachite green lake.
Examples of black pigments include azine dyes such as carbon black, oil furnace black, channel black, lamp black, acetylene black, and aniline black, metal salt azo dyes, metal oxides, and composite metal oxides.
These can use 1 type (s) or 2 or more types.

  The toner for image formation according to the present invention may contain a charge control agent in the toner, if necessary. For example, nigrosine, azine dyes containing an alkyl group having 2 to 16 carbon atoms (Japanese Patent Publication No. 42-1627), basic dyes such as C.I. I. Basic Yellow 2 (C.I. 41000), C.I. I. Basic Yellow 3, C.I. I. Basic Red 1 (C.I. 45160), C.I. I. Basic Red 9 (C.I. 42500), C.I. I. Basic Violet 1 (C.I. 42535), C.I. I. Basic Violet 3 (C.I. 42555), C.I. I. Basic Violet 10 (C.I. 45170), C.I. I. Basic Violet 14 (C.I. 42510), C.I. I. Basic Blue 1 (C.I. 42025), C.I. I. Basic Blue 3 (C.I. 51005), C.I. I. Basic Blue 5 (C.I. 42140), C.I. I. Basic Blue 7 (C.I. 42595), C.I. I. Basic Blue 9 (C.I. 52015), C.I. I. Basic Blue 24 (C.I. 52030), C.I. I. Basic Blue 25 (C.I. 52025), C.I. I. Basic Blue 26 (C.I. 44045), C.I. I. Basic Green 1 (C.I. 42040), C.I. I. Lake pigments of these basic dyes, such as Basic Green 4 (C.I. 42000), C.I. I. Solvent Black 8 (CI. 26150), quaternary ammonium salts such as benzoylmethyl hexadecyl ammonium chloride, decyl trimethyl chloride, or dialkyl tin compounds such as dibutyl or dioctyl, dialkyl tin borate compounds, guanidine derivatives, containing amino groups Polyamine resins such as vinyl polymers, condensation polymers containing amino groups, Japanese Patent Publication No. 41-20153, Japanese Patent Publication No. 43-27596, Japanese Patent Publication No. 44-6397, Japanese Patent Publication No. 45-26478 Metal complex salts of the monoazo dyes described, salicylic acid, dialkylsalicylic acid, naphthoic acid, dicarboxylic acid Zn, Al, Co, Cr described in Japanese Patent Publication No. 55-42752 and Japanese Patent Publication No. 59-7385 , Fe, etc. Metal complex, a copper phthalocyanine pigment obtained by sulfonation, organic boron salts, fluorine-containing quaternary ammonium salts, calixarene compounds, and the like. Naturally, color toners other than black should avoid the use of charge control agents that impair the desired color, and white metal salts of salicylic acid derivatives are preferably used.

In the image forming toner of the present invention, in addition to the silicon carbide, inorganic fine particles such as silica, titanium oxide, alumina, silicon nitride, boron nitride, silicon carbide that does not satisfy the above requirements, and resin fine particles are externally added to the base toner particles. It is preferable to do. Such external addition can further improve transferability and durability.
The ratio (B: A) of the amount (B) of these additional external fine particles to the amount (A) of the silicon carbide in the present invention is usually (90 to 10:10 to 90), preferably (80 to 20: 20 to 80), more preferably (70 to 25:30 to 75).

  A further improved effect can be obtained by covering the wax that lowers transferability and durability with these external additives and reducing the contact area due to the toner surface being covered with fine particles. The surface of these inorganic fine particles is preferably subjected to a hydrophobic treatment, and metal oxide fine particles such as silica and titanium oxide subjected to the hydrophobic treatment are preferably used. As the resin fine particles, polymethyl methacrylate or polystyrene fine particles having an average particle size of about 0.05 to 1 μm obtained by a soap-free emulsion polymerization method are suitably used. In addition, the combination of hydrophobized silica and hydrophobized titanium oxide increases the amount of hydrophobized titanium oxide externally added compared to the amount of hydrophobized silica externally charged. The toner is excellent in the stability of the toner, and can be improved in toner transfer rate and the main problem of the present invention, which is good in filming resistance.

In combination with the above-mentioned inorganic fine particles, silica having a specific surface area of 20 to 50 m ² / g and resin fine particles having an average particle diameter of 1/100 to 1/8 of the average particle diameter of the toner are conventionally used. The durability can be improved by externally adding an external additive having a particle size larger than that of the additive to the toner. This is because the metal oxide particles externally added to the toner tend to be embedded in the base toner particles in the process where the toner is mixed and stirred with the carrier in the developing device, charged, and used for development. This is because it is possible to prevent the metal oxide fine particles from being embedded by externally adding an external additive having a particle size larger than that of the oxide fine particles to the toner.

  The above-mentioned inorganic fine particles and resin fine particles are contained (internally added) in the toner, but the effect is reduced as compared with the case of external addition, but the effect of improving transferability and durability can be obtained and the pulverization property of the toner can be improved. Can do. In addition, since external addition and internal addition can be used together to suppress embedding of externally added fine particles, excellent transferability can be stably obtained and durability can be improved.

  In addition, the following are mentioned as a typical example of the hydrophobization processing agent used here. Dimethyldichlorosilane, trimethylchlorosilane, methyltrichlorosilane, allyldimethyldichlorosilane, allylphenyldichlorosilane, benzyldimethylchlorosilane, bromomethyldimethylchlorosilane, α-chloroethyltrichlorosilane, p-chloroethyltrichlorosilane, Chloromethyldimethylchlorosilane, chloromethyltrichlorosilane, p-chlorophenyltrichlorosilane, 3-chloropropyltrichlorosilane, 3-chloropropyltrimethoxysilane, vinyltriethoxysilane, vinylmethoxysilane, vinyl-tris (β-methoxyethoxy) ) Silane, γ-methacryloxypropyltrimethoxysilane, vinyltriacetoxysilane, divinyldichlorosilane, dimethylvinylchlorosilane, octyl Trichlorosilane, decyl-trichlorosilane, nonyl-trichlorosilane, (4-t-propylphenyl) -trichlorosilane, (4-t-butylphenyl) -trichlorosilane, dipentyl-dichlorosilane, dihexyl-dichlorosilane, dioctyl-dichlorosilane, dinonyl -Dichlorosilane, didecyl-dichlorosilane, didodecyl-dichlorosilane, dihexadecyl-dichlorosilane, (4-t-butylphenyl) -octyl-dichlorosilane, dioctyl-dichlorosilane, didecenyl-dichlorosilane, dinonenyl-dichlorosilane, di-2-ethylhexyl-dichlorosilane, di- 3,3-dimethylpentyl-dichlorosilane, trihexyl-chlorosilane, trioctyl-chlorosilane, tridecyl-chlorosilane Dioctyl-methyl-chlorosilane, octyl-dimethyl-chlorosilane, (4-t-propylphenyl) -diethyl-chlorosilane, octyltrimethoxysilane, hexamethyldisilazane, hexaethyldisilazane, diethyltetramethyldisilazane, hexaphenyldisilazane , Hexatolyl disilazane and the like. In addition, titanate coupling agents and aluminum coupling agents can also be used.

  In addition, as an external additive for the purpose of improving the cleaning property, a lubricant such as an aliphatic metal salt or a fine particle of polyvinylidene fluoride can be used in combination.

  When the toner of the present invention is used for a two-component developer, it is used by mixing with carrier powder. As the carrier in this case, a known carrier can be used, and examples thereof include iron powder, ferrite powder, magnetite powder, nickel powder, glass beads, and the like whose surface is coated with a resin, etc. The diameter is preferably a volume average particle diameter of 25 to 200 μm.

  As the toner container of the present invention, a developer containing the image forming toner of the present invention is filled, and a conventionally known shape can be used.

  The method for producing the toner of the present invention is not particularly limited, and includes a melt-kneading pulverization method and a polymerization method, a polyaddition reaction method using an isocyanate group-containing prepolymer, a solvent dissolution method, a solvent removal method, and a pulverization method. In addition, it can be produced by a melt spray method. Among these production methods, a melt kneading method, a polymerization method in which a monomer composition containing a specific crystalline polymer and a polymerizable monomer is directly polymerized in an aqueous phase (suspension polymerization method / emulsification method). Polymerization method), a polyaddition reaction method in which a composition containing a specific crystalline polymer material and an isocyanate group-containing prepolymer is directly extended / crosslinked with amines in an aqueous phase, dissolved in a solvent, desolvated and pulverized. It is preferable to employ a method for the production, and a conventionally known production method can be used.

  As an apparatus for melt-kneading the toner, a batch type twin roll, a Banbury mixer and a continuous type twin screw extruder, for example, KTK type twin screw extruder manufactured by Kobe Steel, TEM type twin screw extruder manufactured by Toshiba Machine Co., Ltd. , KCK's twin screw extruder, Ikegai Iron Works 'PCM type twin screw extruder, Kurimoto Iron Works' KEX type twin screw extruder, continuous single screw kneader, such as Bush's co-kneader Preferably used.

  In the polymerization method and the polyaddition reaction method using an isocyanate group-containing prepolymer, the emulsification (formation of droplets) treatment is mandatory by applying mechanical energy in the aqueous phase. Examples of the mechanical energy applying means include strong stirring such as homomixer, ultrasonic wave, and manton gorin, or ultrasonic vibration energy applying means.

  For pulverization, coarse pulverization can be performed using a hammer mill, a rotoplex, or the like, and a fine pulverizer using a jet stream or a mechanical pulverizer can be used. The average particle size is 3 to 15 μm. It is desirable to do so. Further, the pulverized product is adjusted in particle size to 5 to 20 μm by a wind classifier or the like.

  The external additive is externally added to the base toner by mixing and stirring the base toner and the external additive using a mixer to coat the toner surface while the external additive is being crushed. At this time, it is important in terms of durability that external additives such as inorganic fine particles and resin fine particles are uniformly and firmly attached to the base toner.

  An example of a developing device using the toner of the present invention as a developer will be described with reference to FIG.

In this apparatus, the electrostatic latent image is visualized by the developing device (3), and a toner image is formed on the photoreceptor (1).
The developing device (3) includes a reverse developing roller (11) that rotates in a direction opposite to the moving direction (rotating direction) of the photoconductor (1), and a moving direction (rotating direction) of the photoconductor (1). On the other hand, it has a center-feed type structure in which a forward developing roll (12) rotating in the forward direction is arranged to face. The toner (9) is supplied from the storage part (20) onto the auger-like stirring member (14b) by the toner replenishing means (21) and is conveyed to the front side of the paper while being mixed and stirred with the developer (13). While being further mixed and stirred by the auger-like stirring member (14a), it is conveyed to the back side of the paper. While being conveyed by the auger-like stirring member (14a), the developer (13) is supplied to the developing rolls (11) and (12) and contributes to development. Although FIG. 1 shows a case where one reverse developing roll (11) and one forward developing roll (12) are provided, the number of rolls installed can be increased as necessary.

  The toner concentration sensor (16) is attached to a position at an appropriate distance from the auger-like stirring member (14a) just below the auger-like stirring member (14a). A temperature sensor (18) for detecting the temperature of the developing device (3) is attached in the vicinity of the developing machine in the electrophotographic apparatus. The controller (19) is separately provided in the electrophotographic apparatus, compares the toner density detected by the toner density sensor (16) with the set toner density, and if the toner density is insufficient, the toner replenishing means. (21) is driven to supply toner.

  The toner image on the photoreceptor (1) is transferred onto the recording medium (4) by the transfer device (5), and the toner remaining on the photoreceptor (1) is cleaned cleanly by the cleaning device (7) equipped with a cleaning blade. On the other hand, the toner image transferred onto the recording medium (4) is fixed by the fixing device (6) to obtain a recorded image.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further, this invention is not limited to this. In the following, “part” means part by weight, and “%” means weight%.

<Synthesis example of crystalline polyester resin>
[Synthesis Example 1]
<Crystalline polyester resin No. Synthesis of 1>
A 5-liter four-necked flask equipped with a nitrogen introduction tube, a dehydration tube, a stirrer and a thermocouple was added to 25 mol of 1,4-butanediol, 23.75 mol of fumaric acid, 1.65 mol of trimellitic anhydride, hydroquinone After adding 5.3 g and reacting at 160 ° C. for 5 hours, the temperature was raised to 200 ° C. and reacted for 1 hour, and further reacted at 8.3 KPa for 1 hour, so that crystalline polyester resin No. 1 was reacted. 1 was obtained. The results of X-ray diffraction are shown in FIG. The structural formula of the ester moiety is shown.

<Synthesis Example of Amorphous Polyester Resin>
[Synthesis of Titanium-Containing Catalyst (a)]
A 80% aqueous solution of titanium dihydroxybis (triethanolaminate) is placed in a reaction vessel equipped with a cooling pipe, a stirrer, and a nitrogen introducing pipe capable of bubbling in liquid, and up to 90 ° C under liquid bubbling with nitrogen. Titanium dihydroxybis (triethanolamate) was obtained by gradually raising the temperature and reacting (hydrolyzing) at 90 ° C. for 4 hours.
In the following examples, the titanium-containing catalyst (a) used in the present invention can be obtained by the same synthesis method.

[Synthesis of Linear Polyester Resin (AX1-1)]
In a reactor equipped with a cooling pipe, a stirrer and a nitrogen introduction pipe, 430 parts of PO2 molar adduct of bisphenol A, 300 parts of PO3 molar adduct of bisphenol A, 257 parts of terephthalic acid, 65 parts of isophthalic acid, maleic anhydride 10 parts of acid and 2 parts of titanium dihydroxybis (triethanolaminate) were added as a condensation catalyst, and the reaction was carried out for 10 hours while distilling off the water produced at 220 ° C. under a nitrogen stream. Subsequently, it was made to react under the reduced pressure of 5-20 mmHg, and when the acid value became 5, it took out, cooled to room temperature, and grind | pulverized, and the linear polyester resin (AX1-1) was obtained.
(AX1-1) contained no THF-insoluble matter, and had an acid value of 7, a hydroxyl value of 12, Tg of 60 ° C., Mn of 6940, and Mp of 19100. The ratio of components having a molecular weight of 1500 or less was 1.2%.

[Synthesis of Non-Linear Polyester Resin (AX2-1)]
In a reaction vessel equipped with a condenser, a stirrer and a nitrogen inlet tube, 350 parts of EO2 molar adduct of bisphenol A, 326 parts of PO3 molar adduct of bisphenol A, 278 parts of terephthalic acid, 40 parts of phthalic anhydride and condensation As a catalyst, 2 parts of titanium dihydroxybis (triethanolaminate) was added and reacted at 230 ° C. for 10 hours while distilling off the water generated in a nitrogen stream. Next, the reaction is carried out under reduced pressure of 5 to 20 mmHg. When the acid value becomes 2 or less, the mixture is cooled to 180 ° C., added with 62 parts of trimellitic anhydride, taken out after reaction for 2 hours under sealed at normal pressure, and cooled to room temperature. To obtain a non-linear polyester resin (AX2-1). (AX2-1) contained no THF-insoluble matter, and its acid value was 35, the hydroxyl value was 17, Tg was 69 ° C., Mn was 3920, and Mp was 11200. The ratio of components having a molecular weight of 1500 or less was 0.9%.

[Synthesis of Amorphous Polyester Resin A]
400 parts of (AX1-1) and 600 parts of (AX2-1) were melt-mixed with a continuous kneader at a jacket temperature of 150 ° C. and a residence time of 3 minutes. The molten resin was cooled to 30 ° C. for 4 minutes using a steel belt cooler and pulverized to obtain the amorphous polyester resin A of the present invention.

<Measurement method>
(1) Measuring method of toner adhesion The toner adhesion force (F) is that uncharged toner adheres to a substrate on which a surface of the same quality as the image carrier is formed, and the toner adhesion surface of the substrate faces the receiving substrate. Then, the measurement cell is configured through a spacer, and then the measurement cell is attached to the centrifugal separator so that the centrifugal force acts in the direction perpendicular to the toner adhesion surface. After replacing the receiving substrate of the measurement cell and centrifuging for all the set rotation speeds, the particle diameter d of each toner adhering to a partial region of each of the receiving substrates is measured, and the rotation speeds before and after the toner detachment The centrifugal force (Fc) at f (rpm) is calculated by the following formula (1), and the arithmetic average value of Fc at the number of rotations before and after the toner detachment is used as the adhesive force of each toner, and the common use for the measured adhesive force of all toners is used. Logarithmic arithmetic From the average A, the average value F = 10A of toner adhesion is obtained.

（ただし、ρ：トナーの真比重（ｋｇ／ｍ^３）、ｄ：トナーの粒径（ｍ）、ｒ：回転半径（ｍ）を表す。）

(However, [rho: true specific gravity of the toner ^{(kg / m 3), d} : Toner particle size (m), r: represents the rotation radius (m).)

(2) Measuring method of WAX amount (3) Measuring method of external additive silica content in toner indicated by external additive (4) Measurement of resin acid value and hydroxyl value The measuring method of acid value and hydroxyl value of resin is JIS According to the method specified in K0070. However, when the sample did not dissolve, a solvent such as dioxane or THF, o-dichlorobenzene was used as the solvent.

(5) Measurement of wax melting point A TG-DSC system TAS-100 manufactured by Rigaku Corporation was used. First, about 10 mg of a sample is placed in an aluminum sample container, which is placed on a holder unit and set in an electric furnace. Heat from 25 ° C. to 180 ° C. at a heating rate of 10 ° C./min. The melting point was calculated from the contact point between the tangent line of the endothermic curve near the melting point and the base line using the analysis system in the TAS-100 system.

(6) Measurement of system speed A4 paper, longitudinal direction paper (length of paper passing direction is 297 mm), continuous 100 sheets, output by the corresponding image forming apparatus, the output time from the start to the end is A second, the system When the speed was B, the system speed was determined by the following formula.

Formula:
<Production of toner by kneading and grinding>
The following toner composition was sufficiently mixed with a blender and then melt-kneaded (kneading temperature: 140 ° C., extrusion speed: 10 kg / hour, rolling gap: 2 mm, standing time until pulverization: 72 hours) with a twin screw extruder. Thereafter, this was pulverized and classified to obtain a base toner having a volume average particle diameter of about 7.6 μm. For 100 parts of the base toner, 0.4 parts of hydrophobic silica (surface-treated product with hexamethyldisilazane, average particle size of primary particles is 0.02 μm) and silicon carbide fine particles 0.5 as external additives. Parts were mixed with a Henschel mixer to obtain a cyan toner. The mixing conditions were 1500 rpm and 8 cycles. In 1 cycle, the mixture was stirred for 60 seconds and then stopped for 60 seconds.

-Crystalline polyester resin No. 1 4 parts Amorphous polyester resin A 96 parts Polypropylene wax (melting point: 151 ° C) 5 parts Charge control agent (metal salt of salicylic acid derivative) 2 parts Colorant (copper phthalocyanine blue pigment) 6 parts Hydrophobic Silica 0.4 parts, silicon carbide 0.5 parts

The evaluation results are shown in Table 1.
<Evaluation>
(1) Filming evaluation
[Carrier production]
・ Silicone resin solution 132.2 parts [Solid content 23% by weight (SR2410: manufactured by Toray Dow Corning Silicone)]
Aminosilane 0.66 part [solid content 100% by weight (SH6020: manufactured by Toray Dow Corning Silicone)]
Conductive particle 1 31 parts [Substrate: alumina, surface treatment; lower layer = tin dioxide / upper layer = tin oxide containing tin oxide, particle size: 0.35 μm, particle powder specific resistance: 3.5 Ω · cm]
-300 parts of toluene was dispersed with a homomixer for 10 minutes to obtain a silicone resin coating film forming solution. Volume average particle size: 70 μm calcined ferrite powder is used as the core material, and the temperature inside the coater is 40 ° C. by a Spira coater (Okada Seiko Co., Ltd.) so that the coating film forming solution has a film thickness of 0.15 μm on the core material surface. And dried. The obtained carrier was fired in an electric furnace at 300 ° C. for 1 hour. After cooling, the ferrite powder bulk was pulverized using a sieve having an opening of 125 μm to obtain [Carrier 1].

(Image evaluation)
A modified prototype using the image forming apparatus shown in FIG. 1 using the two-component developer obtained by mixing 4% by weight of the toner prepared as described above and 96% by weight of the prototype carrier. The film was developed and evaluated after running 100,000 sheets at 50,000 sheets / day. Three black solids (A3) were output, and the degree of white-out image portions (corresponding to filming portions on the photoreceptor) was visually evaluated. The drum was visually evaluated for scratch rank.

The evaluation conditions for the evaluation prototype machine were a linear velocity of 1700 mm / sec, a development gap of 1.26 mm, and a doctor blade gap of 1.6 mm.
Transfer current 1.6 mA.

The evaluation results were visually expressed as the number of white spots on the whole solid image, and ranked as follows.
◎: No whiteout image part ○: There are few whiteout image parts, but there is no problem with visual inspection ×: There are many whiteout image parts

(2) Drum scratch evaluation rank ◎: No scratch ○: There is a scratch, but there is no problem with visual observation on the solid image ×: Many abnormal images on the solid image due to scratch

In Example 1, it evaluated similarly to Example 1 except having changed the following content.
Silicon carbide particle size modified product (Refer to Table 1 for details)

In Example 1, it evaluated similarly to Example 1 except having changed the following content.
The mixing conditions were 1000 rpm and 5 cycles.

In Example 2, it evaluated similarly to Example 2 except having changed the following content.
The mixing conditions were 1000 rpm and 5 cycles.

In Example 1, it evaluated similarly to Example 1 except having changed the following content.
Silicon carbide circularity change product (Refer to Table 1 for details)

In Example 5, it evaluated similarly to Example 5 except having changed the following content.
Silicon carbide circularity change product (Refer to Table 1 for details)

In Example 5, it evaluated similarly to Example 5 except having changed the following content.
The mixing conditions were 1000 rpm and 5 cycles.

In Example 6, it evaluated similarly to Example 6 except having changed the following content.
The mixing conditions were 1000 rpm and 5 cycles.

(Comparative Example 1)
In Example 1, it evaluated similarly to Example 1 except having changed the following content.
Silicon carbide circularity change product (Refer to Table 1 for details)

(Comparative Example 2)
In Example 1, it evaluated similarly to Example 1 except having changed the following content.
Silicon carbide circularity change product (Refer to Table 1 for details)

(Comparative Example 3)
In Example 1, it evaluated similarly to Example 1 except having changed the following content.
Silicon carbide particle size modified product (Refer to Table 1 for details)

(Comparative Example 4)
In Example 1, it evaluated similarly to Example 1 except having changed the following content.
Silicon carbide particle size modified product (Refer to Table 1 for details)

(Comparative Example 5)
In Example 1, it evaluated similarly to Example 1 except having changed the following content.
The mixing conditions were 1600 rpm and 10 cycles.

(Comparative Example 6)
In Example 1, it evaluated similarly to Example 1 except having changed the following content.
The mixing conditions were 900 rpm and 4 cycles.

JP 60-90344 A JP-A 64-15755 Japanese Patent Laid-Open No. 2-82267 JP-A-3-229264 JP-A-3-41470 JP-A-11-305486 JP 62-63940 A Japanese Patent No. 2931899 JP 2001-222138 A JP 2002-214833 A Japanese Examined Patent Publication No. 62-45552 JP 2005-338814 A

DESCRIPTION OF SYMBOLS 1 Photoconductor 2 Charging device 3 Developing device 4 Recording medium 5 Transfer device 6 Fixing device 7 Cleaning device 8 Optical device 9 Toner 10 Carrier 11 Reverse developing roller 12 Forward developing roller 13 Developer 14a Auger-like stirring member 14b Auger-like stirring member Member 15 regulating member 16 toner density sensor 17 paper transport guide plate 18 temperature sensor 19 control unit 20 toner storage part 21 toner replenishing means

Claims (2)

At least a developing step for visualizing the electrostatic latent image formed on the surface of the image carrier using a developer containing toner, and a visible image on the surface of the image carrier on the transfer medium and / or recording medium An image forming method comprising: a transfer step of transferring to a surface; a cleaning step of cleaning transfer residual toner remaining on the surface of the image carrier; and a fixing step of fixing a visible image on a recording medium,
The toner contains at least a binder resin and an inorganic fine powder, the binder resin contains at least a crystalline polyester resin and an amorphous resin, and the inorganic fine powder includes at least a silicon carbide fine powder. The circularity of the silicon carbide fine powder is 0.94 to 0.96, the number average particle size is 0.5 to 1.5 μm,
A centrifugal force is sequentially applied to the uncharged toner on the image carrier at a predetermined rotation speed in a direction perpendicular to the adhesion surface, and an average value F of the centrifugal force at the rotation speed before and after the toner is detached is determined as the adhesion force. The ratio (F / D) of the average value F (nN) to the volume average particle diameter D (μm) of the desorption toner is 0.06 to 0.20 nN / μm, and the F is An uncharged toner is adhered on a substrate on which a surface of the same quality as the image carrier is formed, and a measurement cell is configured through a spacer so that the toner adhesion surface of the substrate faces the receiving substrate, and then the toner adhesion surface Attach the measurement cell to the centrifuge so that the centrifugal force acts in the vertical direction of, and replace the receiving substrate of the measurement cell after each set rotation while increasing the rotation speed, and centrifuge at all the set rotation speeds. After that, each adhered to a partial area of each receiving substrate While measuring the particle diameter d of the toner, the centrifugal force (Fc) at the rotational speed f (rpm) before and after the toner detachment is calculated by the following formula (1), and the arithmetic average value of Fc at the rotational speed before and after the toner detachment is calculated. Is obtained by a method of obtaining an average value F = 10 A of toner adhesion force from the arithmetic average A of the common logarithm regarding the adhesion force of all the measured toners.

(Where ρ represents the true specific gravity of the toner (kg / m ³ ), d represents the particle size (m) of the toner, and r represents the radius of rotation (m).)   An image forming apparatus using the toner.

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