JP4498100B2 - Yellow toner - Google Patents

Description

  The present invention relates to a yellow toner used in an image forming method such as an electrophotographic method, an electrostatic recording method, an electrostatic printing method, and a toner jet method, an image forming apparatus using the yellow toner, and a toner manufacturing method. The present invention is particularly suitable for an image forming method using an oilless fixing method.

  In full-color copying machines and printers, cyan toner, magenta toner, yellow toner, black toner, etc. are used and developed by superimposing each color toner using the subtractive color mixing action, and each color toner image formed by development The toner image is finally superimposed and transferred onto a transfer material such as an OHP sheet or plain paper, and a toner image superimposed on the transfer material is fixed to the transfer material, thereby forming a desired color image. For this reason, it is necessary for the color toner to have transparency so that the upper toner layer does not interfere with the color of the lower toner layer when the colors are mixed. When the transparency of the toner is poor, an image is formed on a sheet for an overhead projector (OHP), and when this image is projected by OHP, the chromaticity of the projected image changes, and the target color cannot be obtained. When the toners are superposed, the color reproduction range becomes narrow, for example, the color of the lower toner does not appear. Also, from the viewpoint of ecology in recent years, on-demand fixing that uses almost no electric power during standby is preferably used, but on-demand fixing tends to be light pressure fixing compared to normal roller fixing, and transparency When bad toner is used, the color reproduction range tends to be further narrowed.

  In recent years, copiers and printers have been sought to be smaller, lighter, faster, and more reliable due to demands for space and energy savings, and machines are simpler elements in various ways. It is coming to be composed. As a result, the performance required for the toner becomes higher, and if the improvement in the performance of the toner cannot be achieved, superior image formation cannot be realized. For example, with respect to the power source, which is an important part of the main body configuration, if the development bias for developing each color can be made common, the number of necessary power sources can be reduced. It is necessary to control gender in the same way.

  In the above color and chargeability studies, among yellow color toners, especially yellow toner has high human sensitivity to changes in hue angle, and changes in chromaticity of transmitted light are easily felt. In addition, the charging property is considerably higher than that of cyan toner and magenta toner, and it is necessary to improve the device by reducing the amount of yellow colorant added to the toner as much as possible. Therefore, in order to solve such problems, the monoazo yellow pigment represented by the following formula (1) is excellent in reflected color and coloring power, so that it is desired to use it for a color toner. However, when dried or heated after the synthesis, the primary particles of the pigment are likely to grow in crystals, and the transparency tends to be problematic. Therefore, there has been a problem of how to disperse the pigment in the toner while suppressing the aggregation of the pigment and the growth of the primary particles and keeping the pigment particle size small.

  For such pigment dispersion problems, in general, after pigment synthesis, after mixing with resin in a water-containing state (paste pigment) without powder, it is dried into pellets, or after powder pigment is heated and mixed with water and resin Techniques for improving pigment dispersibility by making dry pellets have been proposed (see, for example, Patent Documents 1 to 4).

  In addition, it has been proposed to improve the pigment dispersibility by adding an additive to the pigment, or to add an additive during the kneading of the pigment and the resin (see, for example, Patent Documents 5 to 7).

However, according to the study by the present inventors, the method used as a paste pigment form as described above, the method of adding water at the time of kneading the resin and pigment, or the method of using an additive at the time of kneading the resin and pigment, The growth of the primary particles of the pigment cannot be sufficiently suppressed, and there is still room for improvement in terms of permeability and hue. In addition, it was not possible to control charging so that the rising of charging was poor or the chargeability was aligned with other colors. In addition, in the method of mixing different raw materials (additives) with the pigment to improve the dispersibility, the dispersibility is improved, but the color of the pigment itself changes or filming on the photosensitive drum occurs. There were problems such as.
Japanese Patent No. 2910945 JP-A-6-148937 JP-A-6-161154 JP 2002-129089 A JP-A-7-128911 Japanese Patent Laid-Open No. 7-28277 JP-A-9-258487

The present invention has been made in view of the above-described problems in the prior art. The transparency of an image formed on an OHP sheet is good, and the color reproducibility is excellent even when a fixing means for light pressure fixing is used. Another object of the present invention is to provide a yellow toner that has good coloring power and chargeability and that suppresses the occurrence of filming.
Another object of the present invention is to provide a yellow toner excellent in durability that can contribute to simplification and downsizing of the configuration of an image forming apparatus.

Another object of the present invention is to provide an image forming apparatus suitable for providing the yellow toner.
Furthermore, the present invention is to provide a toner production method capable of producing the yellow toner.

The present invention is as follows.
(1) A yellow toner having toner particles containing a binder resin and a colorant,
The binder resin contains at least a polyester unit;
The colorant is C.I. I. Pigment Yellow 74,
When the toner particles have a binder resin and a colorant in the presence of water and the softening point temperature of the binder resin is Tm (° C.), the temperature of the kneaded product immediately after being discharged from the kneader is It is melt-kneaded under the condition of Tm + 10 ° C. or less,
The toner yellow toner lightness ^{L *} in the powder state satisfy ^{L *} ≧ 89.2, and chromaticity ^{b *} is characterized by satisfying the 110.2 ≦ b ^* <120.
(2) The colorant has a median particle size D of 40 to 100 nm and a particle size of 150 nm in the particle size distribution based on the number of colorants when the binder resin and the colorant are mixed during the production of the toner. The yellow toner according to (1) , wherein the particle frequency D150 is 12% or less.

According to the present invention, the transparency of the image formed on the OHP sheet is good, the color reproducibility is excellent even when a light pressure fixing means is used, the coloring power and the charging property are good, and the film It is possible to provide a yellow toner in which occurrence of ming is suppressed.
In addition, according to the present invention, it is possible to provide a yellow toner having excellent durability that can contribute to simplification and downsizing of the configuration of the image forming apparatus, and an image forming apparatus capable of achieving simplification and downsizing of the configuration. it can.

  As a result of intensive investigations to solve the above problems, the present inventors have used a specific binder resin, and by setting the brightness and chromaticity of the toner in a powder state to a specific range, excellent transparency In other words, the toner has the properties and coloring power and can contribute to simplification and downsizing of the configuration of the image forming apparatus.

The yellow toner of the present invention (hereinafter sometimes simply referred to as “toner”) satisfies the lightness L ^* in the powder state of L ^* > 87 and the chromaticity b ^* of 106 <b ^* <120. Satisfied. The configuration of the image forming apparatus main body naturally has a great influence on the toner. With regard to color in particular, various reflections such as a glossy or non-glossy, bright or dark image using the same toner, depending on the fixing system, for example, fixing temperature, fixing pressure, fixing speed, material hardness of the fixing roller, etc. An image is obtained. That is, even when the same toner is used, it is difficult to always obtain the same fixed image because it is affected by external factors such as the configuration and environment of the apparatus used for image formation. Therefore, the evaluation of the expressive power related to the color of the toner itself is effective by directly measuring the color of the toner itself rather than using the fixed image of the toner.

There is an L ^* a ^* b ^* color system in which colors are expressed numerically (color space). This L ^* a ^* b ^* color system is composed of lightness L ^* and a ^* and b ^* indicating chromaticity, where a ^* indicates the chromaticity in the red direction and b ^* indicates the chromaticity in the yellow direction. Important items regarding yellow toner are L ^* and b ^* . That is, in yellow toner, L ^* can be regarded as a parameter related to transparency, and b ^* can be regarded as a parameter related to coloring power. The yellow toner of the present invention has 87 <L ^* in the powder state and 106 <b ^* <120. By specifying L ^* and b ^* within the above ranges, a yellow toner having excellent transparency and coloring power can be obtained. In order to further exhibit the effects of the present invention, the lightness L ^* is preferably 88 <L ^* , more preferably 90 <L ^* , and the chromaticity b ^* is preferably 108 <b ^* <120. Preferably 112 <b ^* <120.

If 87 ≧ L ^* , the transparency is insufficient, so that the color mixing when colors are superimposed is inferior and the color reproduction range is narrowed. Regarding b ^* , the higher the numerical value, the higher the coloring power. Therefore, focusing attention only on the reproduction of yellow on the image, it is preferable that b ^* is high, but if b ^* ≧ 120, In some cases, too little yellow toner is required to produce a color image, and the color mixture with other color toners becomes unbalanced, resulting in color unevenness. For example, when expressing green, green is expressed by mixing yellow and cyan. At that time, the amount of yellow used is very small compared to cyan, and yellow toner is sparsely present in cyan toner. Cyan dots may occur.

Therefore, regarding L ^* and b ^* , it is important to satisfy 87 <L ^* and 106 <b ^* <120 simultaneously in terms of color mixing and color unevenness.

  The yellow toner in the present invention is a toner used for forming a full color image using, for example, three colors of cyan, magenta, and yellow or four colors including black. It can also be used in combination with toner.

In order to obtain a yellow toner having a powder state of 87 <L ^* and 106 <b ^* <120, the dispersion state of the yellow colorant in the toner must be finer and more uniform than before. is required.

Conventionally, as a toner production method, a part of a binder resin and a colorant are premixed to prepare a colorant dispersion resin having a high colorant concentration, a so-called “colorant masterbatch”. A method for improving the dispersibility of the colorant in the toner by mixing the colorant masterbatch with the remaining binder resin and other components has been known. Preparation of the colorant masterbatch is, for example, after the colorant synthesis, the water-containing colorant (paste colorant) that has not passed through the powder state (not dried) and the resin are heated and mixed, and then dried into pellets and mastered. The method by the flushing process which prepares a batch, prepares a masterbatch by heat-mixing powder colorant, water, and resin, and making dry pellets is mentioned. Although the dispersibility of the colorant is improved by performing the flushing treatment, there is a problem that the yellow colorant particles are grown by the amount of heat for drying and pelletizing after heat mixing with the resin. In addition, there was a problem that the yellow colorant particles were further grown by giving more heat than necessary in the kneading step of mixing the colorant masterbatch, resin, charge control agent, and release agent. .

In order to produce the yellow toner of the present invention, for example, the following production method can be mentioned.
First, when preparing the colorant masterbatch, the resin and the colorant are heated and mixed in the presence of water by using a paste colorant or adding water, and the colorant is dispersed in the resin. Let After that, if the water usually evaporates and the colorant masterbatch is dried, only the minimum amount of heat is applied, and the water in the colorant masterbatch is not evaporated completely. Leave it as it is and use it in the next step (usually the melt-kneading step). By giving as little heat as possible to the yellow colorant, it is possible to suppress the growth of the colorant and to disperse the fine colorant in the toner particles.

  The water content of the water-containing colorant masterbatch (water-containing colorant masterbatch) has a great influence on the toner quality. The water content of the desired colorant master batch in the present invention is 5 to 25% by mass, preferably 8 to 20% by mass. When the water content is reduced to less than 5% by mass, an excessive amount of heat is imparted to the yellow colorant, and as a result, the particle growth may be adversely affected. On the other hand, if the water content is more than 25% by mass, adhering to the apparatus wall surface and non-uniform agglomerates may occur during mixing of the toner raw materials, or the stability of charging to the kneader may be reduced. Therefore, it is difficult to satisfactorily disperse the colorant in the toner particles, and color uniformity and charging uniformity are likely to be lowered.

  That is, in the present invention, at least the step of heating and mixing the colorant and a part of the binder resin in the presence of water to obtain a water-containing colorant master batch having a water content of 5 to 25% by mass; The toner is preferably manufactured through a melt-kneading step of melt-kneading the water-containing colorant master batch and the remaining binder resin to obtain a kneaded product; and a pulverizing step of pulverizing the kneaded product to obtain a toner.

  In the melt-kneading step of the water-containing colorant master batch and other toner materials (binder resin, release agent, charge control agent, etc.), the kneading resin temperature Tmix (° C.) is set to the softening point temperature of the binder resin. For Tm (° C.), a range satisfying Tmix ≦ Tm + 20 is preferable. By setting the kneading resin temperature Tmix to the above value, it is possible to prevent an excessive amount of heat from being imparted to the yellow colorant, and to suppress particle growth of the yellow colorant. When kneading with other toner materials using a commonly used dry colorant masterbatch, it is extremely difficult to control the kneading resin temperature Tmix so as to satisfy Tmix ≦ Tm + 20. As the temperature continues, the temperature may rise and Tmix> Tm + 20. If the temperature is set too low, the resin viscosity is high and kneading itself becomes difficult. On the other hand, when a colorant masterbatch having an appropriate water content as described above is used, kneading control at a low temperature can be achieved by setting the kneading temperature and adjusting the screw rotation speed and the heat of vaporization of water.

  The “kneading resin temperature (Tmix)” in the present invention is the resin temperature immediately after the end of the melt-kneading process, and is obtained by measuring the resin temperature immediately after being discharged from the kneader.

  If the softening point temperature Tm (° C.) of the binder resin is too high, the fixability is inferior, and if it is too low, the storage stability of the toner is deteriorated, so 90 ≦ Tm ≦ 140 is preferable, and 95 ≦ Tm ≦ 130 is more preferable. It is.

  Furthermore, when kneading the binder resin and the colorant, or when producing a colorant masterbatch when passing through the colorant masterbatch, it has been described above by controlling the particle size distribution of the colorant used. It has been found that the effect of not growing the colorant particles is further enhanced. In the particle size distribution of the colorant when kneaded with the resin in the present invention, the median diameter D in the number-based particle size distribution is preferably 100 nm or less, and the particle frequency D150 having a particle size of 150 nm or more is preferably 12% or less. By using a colorant having such a particle size distribution as a starting material, the effect of suppressing the particle growth of the colorant in the masterbatch preparation step and the toner material melt-kneading step can be further exhibited. In order to further emphasize such an effect of the present invention, it is more preferable that the median diameter D in the particle size distribution is 40 to 90 nm and the particle frequency D150 is 8% or less. When D150> 12%, a large number of large particles exist, so these large particles may become the nucleus of growth and form considerably large colorant particles. For this reason, the thing which does not contain the particle | grains of as large a particle size as possible is preferable. On the other hand, when the median diameter D exceeds 100 nm, the particle diameter of the colorant itself is too large, so that the transparency and coloring power are inferior. Conversely, when D is 40 nm, the weather resistance tends to be inferior, which is not preferable.

In the yellow toner produced as described above, the dispersion state of the yellow colorant in the toner particles is finer and more uniform than in the past, so that it has a high coloring power as 106 <b ^*. In addition, the amount of the yellow colorant in the toner itself can be reduced. In general, yellow colorants have higher chargeability than other colorants, so development using yellow toner should be performed with the same development contrast as the other colors and the same development bias as the other colors. However, since the yellow toner of the present invention can provide sufficient coloring power even if the yellow colorant content is reduced, the yellow colorant content is reduced to minimize the influence on charging. Can be suppressed. As a result, substantially the same development contrast as that of the other colors can be achieved. As a result, the development bias applied by the development bias supply means common to the other colors can be used, and the configuration of the image forming apparatus can be simplified and miniaturized. It becomes possible.

  In order to control the chargeability of the toner, it is also important to control the chargeability of the binder resin, which is the majority of the toner. In particular, since the binder resin is largely involved in the rise of charging, it is effective to use a binder resin containing a polyester unit having excellent rise characteristics. The binder resin containing the polyester unit used in the toner of the present invention has (a) a polyester resin and (b) a polyester unit and a vinyl copolymer unit because of the rising property of charge and the dispersibility of the release agent. Chemically bonded hybrid resin, (c) a mixture of hybrid resin and vinyl copolymer, (d) a mixture of polyester resin and vinyl copolymer, (e) a mixture of hybrid resin and polyester resin, Or (f) Resins selected from any of polyester resins, hybrid resins, and mixtures with vinyl copolymers are preferred.

Furthermore, the binder resin used in the present invention has a main peak in the molecular weight region of 3,500 to 30,000 in the molecular weight distribution of THF (tetrahydrofuran) soluble matter measured by gel permeation chromatography (GPC). More preferably in the region of molecular weight 5,000 to 20,000, weight average molecular weight Mw and number average molecular weight M
The n ratio Mw / Mn is preferably 5.0 or more.

  When the main peak is in a region having a molecular weight of less than 3,500, the hot offset resistance of the toner tends to be insufficient. On the other hand, when the main peak is in the region of molecular weight exceeding 30,000, sufficient low-temperature fixability cannot be obtained, and application to high-speed fixing becomes difficult. Moreover, when Mw / Mn is less than 5.0, it becomes difficult to obtain good offset resistance.

  In the present invention, “polyester unit” refers to a portion derived from polyester, and “vinyl copolymer unit” refers to a portion derived from a vinyl copolymer. Examples of the polyester monomer constituting the polyester unit include a polyvalent carboxylic acid component and a polyhydric alcohol component.

  When a polyester resin containing a polyester unit is used as the binder resin, a polyhydric alcohol and a polyvalent carboxylic acid, carboxylic acid anhydride, carboxylic acid ester, or the like can be used as a raw material monomer. Specifically, for example, as the dihydric alcohol component, polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene (3.3) -2,2-bis ( 4-hydroxyphenyl) propane, polyoxyethylene (2.0) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene (2.0) -polyoxyethylene (2.0) -2,2 -Bis (4-hydroxyphenyl) propane, polyoxypropylene (6) -2,2-bis (4-hydroxyphenyl) propane and other alkylene oxide adducts of bisphenol A, or ethylene glycol, diethylene glycol, triethylene glycol, 1 , 2-Propylene glycol, 1,3-propylene glycol, 1,4-butanedio , Neopentyl glycol, 1,4-butenediol, 1,5-pentanediol, 1,6-hexanediol, 1,4-cyclohexanedimethanol, dipropylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, bisphenol A, hydrogenated bisphenol A and the like.

  Examples of trihydric or higher alcohol components include sorbitol, 1,2,3,6-hexanetetrol, 1,4-sorbitan, pentaerythritol, dipentaerythritol, tripentaerythritol, 1,2,4-butanetriol, 1,2,5-pentanetriol, glycerol, 2-methylpropanetriol, 2-methyl-1,2,4-butanetriol, trimethylolethane, trimethylolpropane, 1,3,5-trihydroxymethylbenzene, etc. Can be mentioned.

  Examples of the acid component include aromatic dicarboxylic acids such as phthalic acid, isophthalic acid and terephthalic acid or anhydrides thereof; alkyl dicarboxylic acids such as succinic acid, adipic acid, sebacic acid and azelaic acid or anhydrides thereof; Succinic acid substituted with an alkyl group or an anhydride thereof; unsaturated dicarboxylic acids such as fumaric acid, maleic acid and citraconic acid or anhydrides thereof;

  Among them, in particular, a bisphenol derivative represented by the following general formula (2) as a diol component, a carboxylic acid component (for example, fumaric acid) composed of a divalent or higher carboxylic acid or an acid anhydride thereof, or a lower alkyl ester thereof. A polyester resin obtained by polycondensation using acid, maleic acid, maleic anhydride, phthalic acid, terephthalic acid, trimellitic acid, pyromellitic acid, etc.) as an acid component is preferable because it has good charging characteristics as a color toner.

（式中、Ｒはエチレン又はプロピレン基を示し、ｘ、ｙはそれぞれ１以上の整数であり、且つｘ＋ｙの平均値は２〜１０である。）

(In the formula, R represents an ethylene or propylene group, x and y are each an integer of 1 or more, and the average value of x + y is 2 to 10.)

  Moreover, when using a polyester resin as binder resin used by this invention, this resin may have a crosslinked structure. Examples of the trivalent or higher polyvalent carboxylic acid component for forming a polyester resin having a crosslinking site include 1,2,4-benzenetricarboxylic acid, 1,2,5-benzenetricarboxylic acid, 1,2,4, and the like. -Naphthalene tricarboxylic acid, 2,5,7-naphthalene tricarboxylic acid, 1,2,4,5-benzenetetracarboxylic acid, and anhydrides and ester compounds thereof. The amount of the trivalent or higher polyvalent carboxylic acid component used is preferably 0.1 to 1.9 mol% based on all monomers constituting the polyester resin.

  Furthermore, when a hybrid resin having a polyester unit and a vinyl copolymer unit is used as the binder resin, further improved wax dispersibility, low-temperature fixability, and offset resistance can be expected. The “hybrid resin” used in the present invention means a resin obtained by chemically bonding a vinyl copolymer unit and a polyester unit. Specifically, a polyester unit and a vinyl copolymer unit obtained by polymerizing a monomer having a carboxylic acid ester group such as (meth) acrylic acid ester are formed by a transesterification reaction. A graft copolymer (or block copolymer) in which the copolymer unit is a trunk polymer and the polyester unit is a branch polymer is formed. In the present invention, the “hybrid resin component” refers to a component constituting the hybrid resin (that is, a resin component having a structure in which a vinyl copolymer unit and a polyester unit are chemically bonded).

The following are mentioned as a vinyl-type monomer for producing | generating a vinyl-type copolymer unit and a vinyl-type copolymer. Styrene; o-methylstyrene, m-methylstyrene, p-methylstyrene, α-methylstyrene, p-phenylstyrene, p-ethylstyrene, 2,4-dimethylstyrene, pn-butylstyrene, p-tert- Butyl styrene, pn-hexyl styrene, pn-octyl styrene, pn-nonyl styrene, pn-decyl styrene, pn-dodecyl styrene, p-methoxy styrene, p-chloro styrene, 3, Styrene derivatives such as 4-dichlorostyrene, m-nitrostyrene, o-nitrostyrene, p-nitrostyrene; styrene unsaturated monoolefins such as ethylene, propylene, butylene and isobutylene; unsaturated polyenes such as butadiene and isoprene Vinyl chloride, vinyl chloride, vinyl bromide, vinyl fluoride Which vinyl halides; vinyl esters such as vinyl acetate, vinyl propionate, vinyl benzoate; methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-octyl methacrylate, Α-methylene aliphatic monocarboxylic acid esters such as dodecyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, phenyl methacrylate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate; methyl acrylate, ethyl acrylate, acrylic Propyl acid, n-butyl acrylate, isobutyl acrylate, n-octyl acrylate, dodecyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, 2-chlore acrylate , Acrylic esters such as phenyl acrylate; vinyl ethers such as vinyl methyl ether, vinyl ethyl ether, vinyl isobutyl ether; vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone, methyl isopropenyl ketone; N-vinyl pyrrole, N-vinyl compounds such as N-vinyl carbazole, N-vinyl indole and N-vinyl pyrrolidone; vinyl naphthalenes; acrylic acid or methacrylic acid derivatives such as acrylonitrile, methacrylonitrile and acrylamide.

  Further, unsaturated dibasic acids such as maleic acid, citraconic acid, itaconic acid, alkenyl succinic acid, fumaric acid, mesaconic acid; maleic anhydride, citraconic anhydride, itaconic anhydride, alkenyl succinic anhydride, etc. Unsaturated dibasic acid anhydride; maleic acid methyl half ester, maleic acid ethyl half ester, maleic acid butyl half ester, citraconic acid methyl half ester, citraconic acid ethyl half ester, citraconic acid butyl half ester, itaconic acid methyl half ester, Unsaturated dibasic acid half esters such as alkenyl succinic acid methyl half ester, fumaric acid methyl half ester, mesaconic acid methyl half ester; dimethylmaleic acid, dimethyl fumaric acid, etc .; acrylic acid, methacrylate Α, β-unsaturated acids such as phosphoric acid, crotonic acid and cinnamic acid; α, β-unsaturated acid anhydrides such as crotonic acid anhydride and cinnamic acid anhydride, the α, β-unsaturated acid and lower fatty acids And monomers having a carboxyl group, such as alkenylmalonic acid, alkenylglutaric acid, alkenyladipic acid, acid anhydrides and monoesters thereof.

  Furthermore, acrylic acid or methacrylic acid esters such as 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate; 4- (1-hydroxy-1-methylbutyl) styrene, 4- (1-hydroxy-1) -Methylhexyl) Monomers having a hydroxy group such as styrene.

  In the toner of the present invention, the vinyl copolymer unit of the binder resin may have a crosslinked structure crosslinked with a crosslinking agent having two or more vinyl groups. Examples of the crosslinking agent used in this case include divinylbenzene and divinylnaphthalene as aromatic divinyl compounds; examples of diacrylate compounds linked by an alkyl chain include ethylene glycol diacrylate and 1,3-butylene glycol diene. Examples include acrylate, 1,4-butanediol diacrylate, 1,5-pentanediol diacrylate, 1,6 hexanediol diacrylate, neopentyl glycol diacrylate and those obtained by replacing acrylate of the above compounds with methacrylate; ether Examples of diacrylate compounds linked by an alkyl chain containing a bond include diethylene glycol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, polyethylene, and the like. Glycol # 400 diacrylate, polyethylene glycol # 600 diacrylate, dipropylene glycol diacrylate and the above compounds in which acrylate is replaced by methacrylate; di-linked by a chain containing an aromatic group and an ether bond Examples of acrylate compounds include polyoxyethylene (2) -2,2-bis (4-hydroxyphenyl) propane diacrylate, polyoxyethylene (4) -2,2-bis (4-hydroxyphenyl) propane diacrylate and What replaced the acrylate of the above compound with the methacrylate is mentioned.

  Polyfunctional cross-linking agents include pentaerythritol triacrylate, trimethylol ethane triacrylate, trimethylol propane triacrylate, tetramethylol methane tetraacrylate, oligoester acrylate, and acrylates of the above compounds replaced with methacrylate; triallylcia Examples include nurate and triallyl trimellitate.

Examples of the polymerization initiator used when producing a vinyl polymer in the present invention include 2,2′-azobisisobutyronitrile and 2,2′-azobis (4-methoxy-2,4-dimethylvalero). Nitrile), 2,2′-azobis (-2,4-dimethylvaleronitrile), 2,2′-azobis (-2methylbutyronitrile), dimethyl-2,2′-azobisisobutyrate, 1, 1′-azobis (1-cyclohexanecarbonitrile), 2- (carbamoylazo) -isobutyronitrile, 2,2′-azobis (2,4,4-trimethylpentane), 2-phenylazo-2,4-dimethyl- 4-methoxyvaleronitrile, 2,2'-azobis (2-methyl-propane), methyl ethyl ketone peroxide, acetylacetone peroxide, cyclohexa Ketone peroxides such as N-peroxide, 2,2-bis (t-butylperoxy) butane, t-butyl hydroperoxide, cumene hydroperoxide, 1,1,3,3-tetramethylbutyl hydroperoxide, Di-t-butyl peroxide, t-butyl cumyl peroxide, di-cumyl peroxide, α, α'-bis (t-butylperoxyisopropyl) benzene, isobutyl peroxide, octanoyl peroxide, decanoyl peroxide , Lauroyl peroxide, 3,5,5-trimethylhexanoyl peroxide, benzoyl peroxide, m-trioyl peroxide, di-isopropyl peroxydicarbonate, di-2-ethylhexyl peroxydicarbonate, di-n Propyl peroxydicarbonate, di-2-ethoxyethyl peroxycarbonate, di-methoxyisopropyl peroxydicarbonate, di (3-methyl-3-methoxybutyl) peroxycarbonate, acetylcyclohexylsulfonyl peroxide, t-butyl peroxy Oxyacetate, t-butyl peroxyisobutyrate, t-butyl peroxyneodecanoate, t-butyl peroxy 2-ethylhexanoate, t-butyl peroxylaurate, t-butyl peroxybenzoate, t-butylperoxyisopropyl carbonate, di-t-butylperoxyisophthalate, t-butylperoxyallyl carbonate, t-amylperoxy 2-ethylhexanoate, di-t-butylperoxyhexahydride Terephthalate, di -t- butyl peroxy azelate and the like.

  As the acid component and alcohol component used when synthesizing the polyester unit in the hybrid resin, the acid component and alcohol component used when synthesizing the polyester resin can be used.

  Examples of the production method capable of preparing the hybrid resin used in the toner of the present invention include the following production methods (1) to (6).

  (1) A vinyl copolymer and a polyester resin are produced separately, then dissolved and swollen in a small amount of an organic solvent, an esterification catalyst and an alcohol are added, and the ester exchange reaction is performed by heating to synthesize. it can.

  (2) A method for producing a polyester unit and a hybrid resin component in the presence of a vinyl copolymer unit in the presence of the vinyl copolymer unit. The hybrid resin component is produced by a reaction between a vinyl copolymer unit (a vinyl monomer can be added if necessary) and a polyester monomer (alcohol, carboxylic acid) and / or polyester. Also in this case, an organic solvent can be appropriately used.

  (3) A method for producing a vinyl copolymer unit and a hybrid resin component in the presence of the polyester unit after the production. The hybrid resin component is produced by a reaction between a polyester unit (a polyester monomer can be added if necessary) and a vinyl monomer and / or vinyl copolymer unit.

(4) After producing the vinyl copolymer unit and the polyester unit, a hybrid resin component is produced by adding a vinyl monomer and / or a polyester monomer (alcohol, carboxylic acid) in the presence of these polymer units. Also in this case, an organic solvent can be appropriately used.

  (5) After production of the hybrid resin component, a vinyl monomer unit and / or a polyester monomer (alcohol, carboxylic acid) are added to perform addition polymerization and / or polycondensation reaction, whereby the vinyl copolymer unit and the polyester unit are Manufactured. In this case, as the hybrid resin component, those produced by the production methods (2) to (4) can be used, and those produced by a known production method can be used as necessary. Furthermore, an organic solvent can be appropriately used.

  (6) A vinyl copolymer unit, a polyester unit and a hybrid resin component are produced by mixing an vinyl monomer and a polyester monomer (alcohol, carboxylic acid, etc.) and continuously performing an addition polymerization and a condensation polymerization reaction. . Furthermore, an organic solvent can be appropriately used.

  In the production methods of (1) to (5) above, a polymer unit having a plurality of different molecular weights and crosslinking degrees can be used as the vinyl copolymer unit and / or the polyester unit.

  The binder resin contained in the yellow toner of the present invention includes a mixture of the polyester and a vinyl copolymer, a mixture of the hybrid resin and a vinyl copolymer, and the polyester resin and the hybrid resin. A mixture, or a mixture of the above polyester resin, hybrid resin and vinyl copolymer may be used. Preferably, a hybrid resin is contained.

  The glass transition temperature of the binder resin contained in the toner of the present invention is preferably 40 to 90 ° C, more preferably 45 to 85 ° C. The acid value of the resin is preferably 1 to 40 mgKOH / g.

  A known charge control agent can also be used in the yellow toner of the present invention. For example, organic metal complexes, metal salts, and chelate compounds such as monoazo metal complexes, acetylacetone metal complexes, hydroxycarboxylic acid metal complexes, polycarboxylic acid metal complexes, and polyol metal complexes. Other examples include carboxylic acid derivatives such as metal salts of carboxylic acids, carboxylic acid anhydrides, esters, and condensates of aromatic compounds. In addition, phenol derivatives such as bisphenols and calixarene are also used. Among these charge control agents, a metal compound of an aromatic carboxylic acid is preferably used from the viewpoint of charge rise.

  The charge control agent used in the present invention is preferably used so that the content with respect to 100 parts by mass of the binder resin is 0.2 to 10 parts by mass, preferably 0.3 to 7 parts by mass. This is because if the amount is less than 0.2 parts by mass, the effect of charging rise cannot be obtained, and if the amount is more than 10 parts by mass, environmental fluctuation increases.

  The yellow toner of the present invention may contain a release agent as described below. Aliphatic hydrocarbon waxes such as low molecular weight polyethylene, low molecular weight polypropylene, olefin copolymers, microcrystalline wax, paraffin wax, and Fischer-Tropsch wax; oxides of aliphatic hydrocarbon waxes such as oxidized polyethylene wax; aliphatic carbonization Block copolymer of hydrogen-based wax; wax mainly composed of fatty acid ester such as carnauba wax, behenyl behenate, and montanic acid ester wax; and deoxidized part or all of fatty acid ester such as deoxidized carnauba wax Etc.

  Examples thereof include partially esterified products of fatty acids and polyhydric alcohols such as behenic monoglyceride; methyl ester compounds having a hydroxyl group obtained by hydrogenating vegetable oils and the like. Particularly preferred waxes are aliphatic hydrocarbon waxes such as paraffin wax, polyethylene, and Fischer-Tropsch wax, which have a short molecular chain and little steric hindrance and excellent mobility.

  In the molecular weight distribution of the release agent, the main peak is preferably in the region of molecular weight 350-2,400, and more preferably in the region of 400-2,000. By giving such a molecular weight distribution, preferable thermal characteristics can be imparted to the toner.

  The endothermic curve in the differential thermal analysis (DSC) measurement of the release agent used in the present invention has one or a plurality of endothermic peaks in the temperature range of 30 to 200 ° C., and the temperature of the maximum endothermic peak in the endothermic peak. Tsc is preferably in the range of 60 ° C. <Tsc <110 ° C., more preferably in the range of 70 ° C. <Tsc <90 ° C. When Tsc is 60 ° C. or lower, toner blocking properties are poor, and when it is 110 ° C. or higher, low-temperature fixing desired from the viewpoint of energy saving cannot be performed sufficiently.

  The addition amount of the release agent used in the present invention is 1 to 10 parts by mass, preferably 2 to 8 parts by mass, with respect to 100 parts by mass of the binder resin. This is because when the amount is less than 1 part by mass, the amount of addition is small, so that a considerable amount of heat and pressure must be applied in order for the release agent to come out on the toner surface during melting and to exhibit its release properties. On the other hand, if the amount exceeds 10 parts by mass, the amount of the release agent in the toner is too large, which may be inferior in transparency and charging characteristics.

  As described above, the binder resin, the colorant, and the release agent are different from each other in chargeability. Therefore, by controlling the chargeability of the binder resin, which is a major part of the toner, charging of the toner is performed. It is important to control sex. At the same time, it is effective to make the addition amount of the yellow colorant as small as possible so that the influence of the yellow colorant on the chargeable toner is minimized to make it equal to the chargeability of other color toners. Therefore, as the colorant for the yellow toner used in the present invention, those having a high coloring power and a monoazo group having a small particle size due to a relatively low molecular weight immediately after pigment synthesis are suitable. For example, C.I. I. Pigment yellow 1, 2, 3, 5, 6, 65, 73, 74, 75, 97, 98, 120, 151, 168, 169, 191, 194, and the like. Among them, one having a structure represented by the following formula (3), such as C.I. I. Pigment Yellow 74, 97, and 194 are preferable.

（式中、Ｒ_１〜Ｒ_５のうち少なくとも１つは−ＯＣＨ_３であり、残りは−Ｈ、−ＮＯ_２、−ＣＨ_３、−Ｃｌ、−ＳＯ_３Ｈ及び−ＳＯ_２ＮＨＣ_６Ｈ_５から選ばれる基を示す。Ｒ_６〜Ｒ_１０は−Ｈ、−ＣＨ_３、−ＯＣＨ_３、−ＯＣ_２Ｈ_５、−ＮＯ_２、−Ｃｌ及び−ＳＯ_３Ｈから選ばれる基を示す。また、Ｒ_８とＲ_９で−ＮＨ−ＣＯ−ＮＨ−を形成してもよい。）

(Wherein at least one of R _{1 to} R ₅ is —OCH ₃ , and the rest are —H, —NO ₂ , —CH ₃ , —Cl, —SO ₃ H and —SO ₂ NHC ₆ H _5. R _{6 to} R ₁₀ each represents a group selected from —H, —CH ₃ , —OCH ₃ , —OC ₂ H ₅ , —NO ₂ , —Cl and —SO ₃ H. ₈ and R ₉ may form —NH—CO—NH—.)

  Among the colorants represented by the above formula (3), C.I. I. Pigment Yellow 74.

  In addition, the usage-amount of a coloring agent is 1-10 mass parts with respect to 100 mass parts of binder resin, Preferably it is 3-8 mass parts.

  Further, as described above, when the toner of the present invention is manufactured, when the colorant master batch is prepared and mixed with other toner materials, the powder state of the colorant as a starting material and the water-containing paste state It is preferable that the median particle size at 100 nm or less (more preferably 40 to 90 nm) and the particle frequency D150 of the particle size 150 nm or more in the number particle size distribution is 12% or less (more preferably 8% or less).

That is, as one of suitable methods for producing the yellow toner of the present invention in which the lightness L ^* in the powder state satisfies L ^* > 87 and the chromaticity b ^* satisfies 106 <b ^* <120, Examples thereof include a method for producing a toner by using the above-mentioned pigment having a monoazo group (monoazo pigment) as an agent and through a specific master batch process. The masterbatch process at this time is to suppress the particle growth of the colorant by keeping the amount of heat applied to the material to a minimum during heating and mixing in which the colorant is uniformly dispersed in a part of the binder resin. It is to produce a water-containing masterbatch having a water content (5 to 25% by mass, preferably 8 to 20% by mass).

Next, a procedure for producing the yellow toner of the present invention will be described.
The yellow toner of the present invention is a raw material mixing step for mixing toner raw materials (internal additives), melting and kneading the raw materials mixed in the raw material mixing step, and obtaining a colored resin composition by dispersing a colorant and the like. It can be preferably manufactured by a manufacturing method including a kneading step, a cooling step for cooling the obtained colored resin composition, and a pulverizing step for pulverizing the cooled resin composition to a predetermined particle size.

  First, in the raw material mixing step, as a toner internal additive, at least a resin and the above-mentioned water-containing colorant master batch are weighed and mixed in a predetermined amount and mixed. Examples of the mixing apparatus include a double-con mixer, a V-type mixer, a drum-type mixer, a super mixer, a Henschel mixer, and a Nauter mixer.

  Next, by melting and kneading the toner raw material mixed in the raw material mixing step, the resins are melted, and the colorant and the like are dispersed therein. In this melt-kneading step, for example, a batch kneader such as a pressure kneader or a Banbury mixer, or a continuous kneader can be used. In recent years, single-screw or twin-screw extruders have become mainstream due to the advantage of being capable of continuous production. For example, KTK type twin screw extruder manufactured by Kobe Steel, TEM type twin screw extruder manufactured by Toshiba Machine Co., Ltd. In general, a twin-screw extruder manufactured by Kay Sea Kay, a co-kneader manufactured by Buss, or the like is used. At this time, as described above, the kneading resin temperature Tmix is set to [binder resin softening point temperature Tm + 20 ° C.] in order to suppress the colorant particle growth and improve the colorant dispersion state in the toner. It is preferable to set the following. Furthermore, the colored resin composition obtained by melt-kneading the toner raw material is rolled by a two-roll roll after melt-kneading, and then cooled through a cooling step of cooling by water cooling or the like.

  Next, the cooled product of the colored resin composition obtained in the cooling step is generally pulverized to a desired particle size in the pulverization step. In the pulverization step, first, coarse pulverization is performed by a crusher, a hammer mill, a feather mill or the like, and further pulverization is performed by a kryptron system manufactured by Kawasaki Heavy Industries, Ltd., a super rotor manufactured by Nissin Engineering Co., Ltd. or the like. After that, if necessary, classification is performed using a classifier such as an inertia class elbow jet (manufactured by Nippon Steel & Mining Co., Ltd.) or a centrifugal class turbo turbo (manufactured by Hosokawa Micron Co., Ltd.), and the weight average particle diameter Gives a classified product of 3 to 11 μm. At this time, if necessary, a classified product may be obtained by performing a surface modification, that is, a spheronization treatment in a surface modification step. Examples of the apparatus used for such surface modification include a hybridization system manufactured by Nara Machinery Co., Ltd. and a mechano-fusion system manufactured by Hosokawa Micron Corporation. Further, if necessary, a sieving machine such as a wind-type sieve high voltor (manufactured by Shin Tokyo Machine Co., Ltd.) may be used.

  The obtained pulverized product or classified product, that is, toner particles, is mixed with a known external additive as necessary to obtain the toner of the present invention. The method of externally adding the external additive to the toner particles is as follows. A high-speed stirrer that gives a shearing force to the powder, such as a Henschel mixer or a super mixer, is used as an external additive, by mixing a predetermined amount of external additives such as silica and titanium oxide into the pulverized or classified toner particles. The toner can be obtained by stirring and mixing.

  As the external additive to be mixed with the toner particles, conventionally known additives can be used, and are not particularly limited. Among them, a fluidizing agent is preferably used in the present invention. Any fluidizing agent can be used as long as it can be added to the toner particles and its fluidity can be increased compared to that before the addition. For example, fluororesin powder such as vinylidene fluoride fine powder, polytetrafluoroethylene fine powder, titanium oxide fine powder, alumina fine powder, wet process silica, fine powder silica such as dry process silica, silane coupling agent, Any surface treated with a titanium coupling agent, silicone oil, etc. can be used.

For example, dry process silica is a fine powder produced by vapor phase oxidation of a silicon halogen compound, which is called so-called dry process silica or fumed silica, and is manufactured by a conventionally known technique. For example, a thermal decomposition oxidation reaction of silicon tetrachloride gas in an oxyhydrogen flame is used, and the basic reaction formula is as follows.
SiCl ₂ + 2H ₂ + O ₂ → SiO ₂ + 4HCl

  In this production process, it is also possible to obtain a composite fine powder of silica and other metal oxides by using other metal halogen compounds such as aluminum chloride or titanium chloride together with silicon halogen compounds. . The particle size is preferably within the range of 0.001 to 2 μm, more preferably 0.002 to 0.2 μm, as the average primary particle size. In particular, silica fine powder having an average primary particle size of 0.002 to 0.2 μm is preferable.

  Furthermore, it is more preferable to use a treated silica fine powder obtained by subjecting a silica fine powder produced by vapor phase oxidation of the silicon halogen compound to a hydrophobic treatment. Among the treated silica fine powders, those obtained by treating the silica fine powder so that the degree of methanol hydrophobicity is in the range of 30 to 80 are particularly preferable. Examples of the hydrophobizing method include a method of chemically treating with an organosilicon compound that reacts or physically adsorbs with silica fine powder.

Examples of such organosilicon compounds are hexamethyldisilazane, trimethylsilane, trimethylchlorosilane, trimethylethoxysilane, dimethyldichlorosilane, methyltrichlorosilane, allyldimethylchlorosilane, allylphenyldichlorosilane, benzyldimethylchlorosilane. , Bromomethyldimethylchlorosilane, α-chloroethyltrichlorosilane, β-chloroethyltrichlorosilane, chloromethyldimethylchlorosilane, triorganosilylmercaptan, trimethylsilylmercaptan, triorganosilylacrylate, vinyldimethylacetoxysilane, dimethylethoxysilane, dimethyl Dimethoxysilane, diphenyldiethoxysilane, hexamethyldisiloxane, 1,3-divinyltetramethyldisiloxane 1,3-diphenyltetramethyldisiloxane, and dimethylpolysiloxane having 2 to 12 siloxane units per molecule and containing hydroxyl groups bonded to one Si at each terminal unit. These are used by 1 type, or 2 or more types of mixtures. In the present invention, an amino group-containing coupling agent or silicone oil can also be used as the treating agent.

The fluidizing agent used in the present invention has good results when the specific surface area by nitrogen adsorption measured by the BET method is 30 m ² / g or more, preferably 50 m ² / g or more. The fluidizing agent is used in an amount of 0.01 to 8 parts by weight, preferably 0.1 to 4 parts by weight, based on 100 parts by weight of the toner.

  When the toner of the present invention is used as a two-component developer, the toner is used by mixing with a magnetic carrier. Examples of the magnetic carrier include surface oxidized or unoxidized iron, lithium, calcium, magnesium, nickel, copper, zinc, cobalt, manganese, chromium, rare earth metal particles, alloy particles thereof, oxide particles, ferrite and the like. Can be used. The coated carrier obtained by coating the surface of the magnetic carrier particles with a resin is particularly preferable in a developing method in which an AC bias is applied to the developing sleeve. Coating methods include a method in which a coating solution prepared by dissolving or suspending a coating material such as a resin in a solvent is adhered to the surface of the magnetic carrier core particles, and a method in which the magnetic carrier core particles and the coating material are mixed with powder. A conventionally known method can be applied.

  Examples of the coating material on the surface of the magnetic carrier core particle include silicone resin, polyester resin, styrene resin, acrylic resin, polyamide, polyvinyl butyral, and aminoacrylate resin. These may be used alone or in combination. The treatment amount of the coating material is preferably 0.1 to 30% by mass (preferably 0.5 to 20% by mass) with respect to the carrier core particles. These carriers have a weight average particle diameter of 10 to 100 μm, preferably 20 to 70 μm.

  When a two-component developer is prepared by mixing the toner of the present invention and a magnetic carrier, the mixing ratio is usually 2 to 15% by mass, preferably 4 to 13% by mass, as the toner concentration in the developer. Good results are obtained. If the toner concentration is less than 2% by mass, the image density tends to decrease, and if it exceeds 15% by mass, fogging or in-machine scattering tends to occur.

  The yellow toner described above can be suitably used for nonmagnetic one-component development.

  The yellow toner of the present invention can be used in a conventionally known image forming apparatus such as an electrophotographic apparatus, and is not particularly limited, but is not limited to an image carrier that carries an electrostatic latent image, and charging that charges the image carrier. A latent image forming means for forming an electrostatic latent image on the image carrier charged by the charging means, and developing for forming a toner image by developing the electrostatic latent image formed on the image carrier. An image forming apparatus having at least a developing unit, wherein the developing unit applies a developing unit that develops using yellow toner, a developing unit B that develops using toner other than yellow toner, and a developing bias applied during development. An image form having a developing bias supply means, and a developing bias at the time of development by the developing means A and a developing bias at the time of development by the developing means B are applied by a common developing bias supply means It is preferably applied to the method.

  Since the yellow toner of the present invention is a color toner, it can be suitably used in a full-color image forming apparatus together with magenta, cyan, and, if necessary, black toner. Here, the full-color image forming apparatus has a unit including a latent image carrier, a charging unit, a latent image forming unit, and a developing unit for each color toner, and a toner image of each color is placed on each color latent image carrier. A so-called tandem system may be used in which a full-color image is obtained by forming the image and transferring and fixing the image on a transfer material. In addition, using a plurality of developing means corresponding to the number of toners used for one latent image carrier, toner images of each color are created on the latent image carrier, and these images are sequentially superimposed on the intermediate transfer member and transferred. In addition, a full color image may be obtained by transferring the toner image transferred onto the intermediate transfer member onto a transfer material. Needless to say, the toner may be used together with toners of colors other than those described above.

  Here, since the yellow toner of the present invention can have the same chargeability as that of other color toners, the developing bias used for the developing means for each color can be shared, and the required power source can be reduced. That is, as described above, each color developing unit can perform development with the developing bias applied from the common developing bias supply unit. Therefore, the configuration of the image forming apparatus can be simplified and reduced in size, which is preferable.

  Further, an image carrier that carries an electrostatic latent image, a charging unit that charges the image carrier, a latent image forming unit that forms an electrostatic latent image on the image carrier charged by the charging unit, and the image carrier Developing means for developing an electrostatic latent image formed on a body with yellow toner to form a yellow toner image, transfer means for transferring the yellow toner image to a transfer material, a rotating heating member, and a pressure contact with the rotating heating member An image forming apparatus including a fixing unit that heat-presses and fixes the yellow toner image on a transfer material, wherein the rotary pressing member is configured to transfer the transfer material to the transfer material. Therefore, it can be suitably used for an image forming apparatus that is pressed against the rotary heating member with a linear pressure of 490 to 980 N / m. That is, the yellow toner of the present invention can form an image with excellent color reproducibility even when a light pressure fixing fixing unit is used. Therefore, the fixing unit having a relatively low linear pressure as described above is used. It can also be suitably used for an image forming apparatus.

Various methods for measuring physical properties used in the present invention will be described below.
1) Measurement of Maximum Endothermic Peak of Release Agent and Toner The maximum endothermic peak of toner is measured using a differential scanning calorimeter (DSC measuring device), DSC-7 (manufactured by PerkinElmer) or DSC2920 (manufactured by TA Instruments Japan). , Measured according to ASTM D3418-82.

  The sample to be measured is precisely weighed 5 to 20 mg, preferably 10 mg. It is put in an aluminum pan, an empty aluminum pan is used as a reference, and measurement is performed at normal temperature and humidity with a measurement range of 30 to 200 ° C. and a temperature increase rate of 10 ° C./min. The temperature curve at the time of measurement is as follows. The maximum endothermic peak of the toner is the peak having the highest height from the base line in the region above the endothermic peak indicating the glass transition temperature Tg of the binder resin in the process of temperature increase II.

Temperature curve: Temperature increase I (30 ° C. to 200 ° C., temperature increase rate 10 ° C./min)
Temperature drop I (200 ° C-30 ° C, temperature drop rate 10 ° C / min)
Temperature increase II (30 ° C to 200 ° C, temperature increase rate 10 ° C / min)

2) Molecular weight measurement of release agent Device: GPC-150C (Waters)
Column: GMH-HT 30 cm, 2 stations (manufactured by Tosoh Corporation)
Temperature: 135 ° C
Solvent: o-dichlorobenzene (0.1% by mass ionol added)
Flow rate: 1.0 ml / min
Sample: 0.4 ml of 0.15 mass% wax was injected.

  The molecular weight calibration curve prepared with the monodisperse polystyrene standard sample is used for the measurement of the molecular weight of the wax under the above conditions. Furthermore, the molecular weight of the release agent is calculated by converting to polyethylene based on a conversion formula derived from the Mark-Houwink viscosity formula.

3) Measurement of molecular weight distribution by GPC of toner and binder resin The molecular weight distribution by GPC in the resin component of toner and binder resin is as follows. Measured by GPC using dissolved components.

That is, the toner is put in THF, left for several hours, and then sufficiently shaken to mix well with THF (until the sample is no longer united), and then left to stand for 12 hours or more. At this time, the standing time in THF is set to be 24 hours or longer. Thereafter, a sample processing filter (pore size 0.45 to 0.5 μm, for example, Mysori Disc H-25-5 manufactured by Tosoh Corporation, Excro Disc 25CR manufactured by Gelman Science Japan Co., Ltd., etc.) can be used. A sample of GPC is used. The sample concentration is adjusted so that the resin component is 0.5 to 5 mg / ml.

The GPC of the sample prepared by the above method is measured as follows. The column is stabilized in a 40 ° C. heat chamber, and tetrahydrofuran (THF) is allowed to flow through the column at this temperature as a solvent at a flow rate of 1 ml per minute, and about 50 to 200 μl of sample is injected for measurement. In measuring the molecular weight of a sample, the molecular weight distribution of the sample is calculated from the relationship between the logarithmic value of a calibration curve prepared from several types of monodisperse polystyrene standard samples and the number of counts (retention time). Examples of standard polystyrene samples for preparing a calibration curve include those manufactured by Tosoh Corporation or Pressure Chemical Co. The molecular weights made are 6 × 10 ² , 2.1 × 10 ³ , 4 × 10 ⁴ , 1.75 × 10 ⁴ , 5.1 × 10 ⁴ , 1.1 × 10 ⁵ , 3.9 × 10 ⁵ , 8 It is suitable to use a standard polystyrene sample of at least about 10 points, using .6 × 10 ⁵ , 2 × 10 ⁶ , 4.48 × 10 ⁶ . An RI (refractive index) detector is used as the detector.

As a column, in order to accurately measure a molecular weight region of 1 × 10 ³ to 2 × 10 ⁶ , it is preferable to combine a plurality of commercially available polystyrene gel columns. For example, shodex GPC KF-801, 802 manufactured by Showa Denko KK , 803, 804, 805, 806, and 807, and combinations of μ-styragel 500, 10 ³ , 10 ⁴ , and 10 ⁵ manufactured by Waters.

4) Measurement of toner particle size distribution In the present invention, the average particle size and particle size distribution of the toner are measured using a Coulter Counter TA-II type (manufactured by Coulter), but it is also possible to use a Coulter Multisizer (manufactured by Coulter). It is. As the electrolytic solution, a 1% NaCl aqueous solution prepared using primary sodium chloride is used. As such an electrolytic solution, for example, ISOTON R-II (manufactured by Coulter Scientific Japan) can be used. As a measuring method, 0.1 to 5 ml of a surfactant, preferably alkylbenzene sulfonate, is added as a dispersant to 100 to 150 ml of the electrolytic aqueous solution, and 2 to 20 mg of a measurement sample is further added. The electrolytic solution in which the sample is suspended is subjected to a dispersion treatment with an ultrasonic disperser for about 1 to 3 minutes, and the volume and number of toner particles having a particle diameter of 2.00 μm or more are measured using the 100 μm aperture as the aperture by the measuring device. The volume distribution and the number distribution are calculated. Then, the weight average particle diameter (D4) obtained from the volume distribution according to the present invention (the median value of each channel is used as the representative value for each channel) is obtained.

  As channels, 2.00 to 2.52 μm; 2.52 to 3.17 μm; 3.17 to 4.00 μm; 4.00 to 5.04 μm; 5.04 to 6.35 μm; 6.35 to 8. 00 μm; 8.00 to 10.08 μm; 10.08 to 12.70 μm; 12.70 to 16.00 μm; 16.00 to 20.20 μm; 20.20 to 25.40 μm; 25.40 to 32.00 μm; 13 channels of 32.00-40.30 μm are used.

5) Measurement of L ^* and b ^{* in} the powder state L ^* and b ^* in the yellow toner in the powder state are the spectral color difference meter “SE-2000” (manufactured by Nippon Denshoku Industries Co., Ltd.) in accordance with JIS Z-8722. ) And the light source is measured with a C light source with a 2-degree field of view. The measurement is performed according to the attached instruction manual. For standardization of the standard version, it is preferable to perform the measurement through a glass having a thickness of 2 mm and a diameter of 30 mm in an optional powder measurement cell. More specifically, the measurement is performed in a state in which a cell filled with the sample powder is placed on the sample table (attachment) for the powder sample of the spectroscopic color difference meter. Before placing the cell on the sample table for powder sample, fill the powder sample with 80% or more with respect to the internal volume of the cell, and apply vibration once per second for 30 seconds on the vibration table. Then, L ^* and b ^* are measured.

6) Method for measuring softening point of resin This refers to that measured by Koka flow tester in accordance with JIS K 7210. A specific measurement method is shown below. While a 1 cm ³ sample was heated at a heating rate of 6 ° C./min using a Koka type flow tester (manufactured by Shimadzu Corporation), a load of 1960 N / m ² (20 kg / cm ² ) was applied by a plunger, and the diameter was 1 mm. , A nozzle with a length of 1 mm is pushed out, thereby drawing a plunger descending amount (flow value) -temperature curve, where the height of the S-shaped curve is h, the temperature corresponding to h / 2 (resin Is the softening point (Tm) of the resin.

7) Particle size measuring method of colorant A pigment is mixed and dispersed in a ratio of 4: 6 with a nonionic surfactant between glass plates (Hoovermarler) (JIS K 5101). This mixed dispersion of surfactant and pigment was diluted with water so that the pigment concentration would be 5% by mass, mixed with ultrasonic waves for 5 minutes, and then subjected to dynamic light scattering particle size distribution measurement ((stock ) HORIBA, Ltd. (LB-500) is performed to determine the median diameter and particle size distribution (number basis). When measuring the particle size of the paste pigment, a dry pigment is used as a measurement sample by vacuum degassing at 60 ° C. so as not to apply heat as much as possible.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated further more concretely, this invention is not limited only to these Examples.

<Example of hybrid resin production>
As monomers for forming a vinyl copolymer unit, styrene: 2.0 mol, 2-ethylhexyl acrylate: 0.21 mol, fumaric acid: 0.14 mol, α-methylstyrene dimer: 0.03 mol, dialkyl Millperoxide: 0.05 mol was placed in a dropping funnel. Moreover, as a monomer for forming the polyester resin unit, polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane: 7.0 mol, polyoxyethylene (2.2) -2, 2-bis (4-hydroxyphenyl) propane: 3.0 mol, terephthalic acid: 3.0 mol, trimellitic anhydride: 1.9 mol, fumaric acid: 5.0 mol and 0.2 g of dibutyltin oxide in 4 liters made of glass The flask was placed in a four-necked flask, and a thermometer, a stirring rod, a condenser and a nitrogen introduction tube were attached and placed in a mantle heater. Next, after the inside of the flask was replaced with nitrogen gas, the temperature was gradually raised while stirring, and the vinyl monomer and the polymerization initiator were dropped over 4 hours from the previous dropping funnel while stirring at a temperature of 145 ° C. did. This was heated to 200 ° C. and reacted for 4 hours to obtain a hybrid resin (Tm = 110 ° C.). The results of molecular weight measurement by GPC are shown in Table 1.

<Examples of polyester resin production>
Polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane: 3.6 mol, polyoxyethylene (2.2) -2,2-bis (4-hydroxyphenyl) propane: 1. 6 mol, terephthalic acid: 1.7 mol, trimellitic anhydride: 1.4 mol, fumaric acid: 2.4 mol, and dibutyltin oxide: 0.12 g were put into a glass 4-liter four-necked flask, a thermometer and stirred A rod, condenser and nitrogen inlet tube were attached and placed in the mantle heater. The mixture was reacted at 215 ° C. for 5 hours under a nitrogen atmosphere to obtain a polyester resin (Tm = 105 ° C.). The results of molecular weight measurement by GPC are shown in Table 1.

<Examples of styrene-acrylic resin production>
-70 parts by mass of styrene-24 parts by mass of n-butyl acrylate-6 parts by mass of monobutyl maleate-1 part by mass of di-t-butyl peroxide While stirring 200 parts by mass of xylene in a four-necked flask, the inside of the container is adequate After replacing with nitrogen and raising the temperature to 120 ° C., the above components were added dropwise over 3.5 hours. Furthermore, the polymerization was completed under reflux of xylene, and the solvent was distilled off under reduced pressure to obtain a styrene-acrylic resin (Tm = 105 ° C.). The results of molecular weight measurement by GPC are shown in Table 1.

<Example 1>
70 parts by mass of hybrid resin; Y. (Pigment yellow) 74 from a pigment slurry containing 74 to a certain extent, and after synthesis, a paste-like pigment having a solid content of 30% by mass (the remaining 70% by mass is water) obtained without any drying process 100 masses A hydrous yellow masterbatch was prepared using a part (first kneading step).

  First, the above raw materials were charged into a kneader type mixer, and the temperature was raised under no pressure while mixing. When reaching the maximum temperature (necessarily determined by the boiling point of the solvent in the paste. In this case, about 80 to 100 ° C.), the pigment in the aqueous phase (pigment slurry) is distributed or transferred to the molten resin phase, After confirming this, the mixture was further melted and kneaded at 90 to 100 ° C. for 15 minutes to sufficiently transfer the pigment in the paste to the molten resin phase. Thereafter, the mixer was stopped once, the hot water was discharged, mixed without heating for 10 minutes to distill off the water, cooled, and pulverized to about 1 mm by pin mill pulverization to obtain a hydrous yellow master batch. This water-containing yellow masterbatch had a water content of 15% by mass, a pigment content of 30% by mass and a resin content of 55% by mass.

Next, the mixture is sufficiently preliminarily mixed with a Henschel mixer with the following formulation, and melt kneaded so that the temperature of the kneading resin immediately after being discharged from the kneader becomes 120 ° C. (= Tm + 10 ° C.). Second kneading).
-86.25 parts by mass of the above hybrid resin (Tm = 110 ° C)-4 parts by mass of purified normal paraffin (maximum endothermic peak temperature 78 ° C)-2 parts by mass of 3,5-di-t-butylsalicylic acid aluminum compound-The above water-containing yellow Master batch (pigment content 30% by mass) 25 parts by mass

  The obtained kneaded product was cooled, coarsely pulverized to a particle size of about 1 to 2 mm using a hammer mill, and then finely pulverized to a particle size of 20 μm or less with an air jet type fine pulverizer. Further, yellow toner base particles 1 (classified product) were obtained from the resulting finely pulverized product using a classifier (elbow jet classifier). The charge rising rate of the obtained classified product was evaluated as follows.

[Measurement of charge rise rate in classified products]
3.5 g of the classified product and 46.5 g of magnetic ferrite carrier particles (Mn-Mg ferrite; average particle size 45 μm) surface-coated with a silicone resin are weighed and placed in a 50 ml plastic bottle under a normal temperature and low humidity environment (23 ° C. / 5%) for 18 hours or more. Then, what was shaken at 200 rpm for 2 minutes with the Yayoi type shaker (model: YS-LD) and what was shaken for 30 minutes were made. The swinging angle was set so that the swinging strut moved 15 degrees forward and 20 degrees backward when the top (vertical) of the shaker was 0 degree. The polybin was fixed to a fixing holder (with the sample bottle lid fixed on the extension of the center of the column) attached to the tip of the column. Each of the prepared samples was measured with the apparatus for measuring the triboelectric charge amount shown in FIG. 1 in the same manner as the method for measuring the triboelectric charge amount of the toner described later, and the charge rising rate was calculated by the following equation.

Charge rise rate (%)
= {(Triboelectric charge amount of sample shaken for 2 minutes)
/ (Triboelectric charge amount of sample shaken for 30 minutes)} × 100

The obtained charge rising rate was evaluated according to the following evaluation items.
A: 75% or more B: 65% or more and less than 75% C: 55% or more and less than 65% D: 40% or more and less than 55% E: Less than 40%

  The evaluation results are shown in Table 3. Thus, the charge rising of the yellow toner base particles 1 was good.

1.2 parts by mass of acicular titanium oxide fine powder (MT-100T: manufactured by Teica, BET = 62 m ² / g, treated with 10% by mass of isobutyltrimethoxysilane) with respect to 100 parts by mass of the yellow toner base particles 1 Was added externally by a Henschel mixer to make yellow toner 1. The weight average particle diameter of the yellow toner 1 was 7.0 μm. The obtained yellow toner 1 was measured for L ^* and b ^{* in} a powder state.

  Further, the yellow toner 1 and magnetic ferrite carrier particles (Mn—Mg ferrite: weight average particle size 45 μm) surface-coated with a silicone resin are mixed so that the toner concentration becomes 7.0% by mass. Developer 1 was obtained.

This two-component developer 1 is filled in a remodeling machine from which the oil application mechanism of the fixing unit of the color copying machine CLC-1000 (manufactured by Canon Inc.) is removed, and is in a single color mode at room temperature and low humidity (N / L environment) , 23 ° C./5% RH), and an original document having an image area ratio of 5% was subjected to a printing test of 10,000 sheets. Then, changes in the charge amount before and after the printing test, filming at the end of the printing test, and evaluation of fogging were performed as follows. In addition, OHP transmittance and color unevenness were evaluated as follows.

[Filming]
After printing 10,000 sheets in a normal temperature and low humidity environment (23 ° C / 5%), 5 consecutive yellow solid images (density 1.6) are printed on the entire surface of A3 paper. And the average number per A3 sheet was calculated and evaluated according to the following evaluation criteria.

A: None at all B: 1 or less C: 1 or more and 3 or less D: More than 3 or less than 5 E: More than 5

[Change in frictional charge]
FIG. 1 is an explanatory diagram of an apparatus for measuring the triboelectric charge amount. About 0.5 to 1.5 g of two-component developer collected from the developing sleeve of a copying machine or printer is placed in a metal measuring container 52 having a screen 53 having a 500 mesh (25 μm opening) at the bottom. The lid 54 was attached. At this time, the entire weight of the measurement container 52 was weighed, and this was designated as W1. Next, in the suction machine 51 (at least the part in contact with the measurement container 52 is an insulator), the pressure of the vacuum gauge 55 is set to 4 kPa by suction from the suction port 57 and adjusting the air volume control valve 56. In this state, suction was performed preferably for 2 minutes, and the two-component developer was removed by suction. At this time, the potential of the electrometer 59 is set to V. Here, 58 is a capacitor and the capacity is C. Moreover, the weight of the whole measurement container after aspiration is weighed and this is set to W2. The triboelectric charge amount (mC / kg) of this sample was calculated from the following equation.
Sample triboelectric charge (mC / kg) = C x V / (W1-W2)
(However, the measurement conditions are 23 ° C. and 60% RH)

  The same measurement was performed at the start and after the end of the printing test for 10,000 sheets, and the change in charge before and after the test was obtained and evaluated according to the following evaluation criteria.

A: Less than 2 mC / kg B: 2 mC / kg or more and less than 4 mC / kg C: 4 mC / kg or more and less than 6 mC / kg D: 6 mC / kg or more and less than 8 mC / kg E: 8 mC / kg or more

[Fog]
After the endurance test, fog was evaluated as follows. As a method for measuring fog, in the case of a yellow image, the average reflectance Dr (%) of plain paper before image printing is measured using a reflectometer equipped with a blue filter (“REFLECTOMETER MODEL TC-6DS manufactured by Tokyo Denshoku Co., Ltd.). )). On the other hand, a solid white image was drawn on plain paper, and then the reflectance Ds (%) of the solid white image was measured. The fog (%) was calculated from the following formula and evaluated according to the following evaluation criteria.
Fog (%) = Dr-Ds

A: Less than 0.7% B: 0.7 or more and less than 1.2% C: 1.2 or more and less than 1.5% D: 1.5 or more and less than 2.0% E: 2.0% or more

[OHP permeability]
Using a color copier CLC-1000 (made by Canon), an unfixed image of A4 half yellow solid image was created on an OHP sheet, and the fixing machine of iRC3200 (made by Canon Inc.) was set to a linear pressure of 784 N / m. Used to fix. At that time, an image was created by adjusting the development contrast so that the yellow solid portion of the OHP fixed image had an image density satisfying the following formula.

D (on solid paper) −D (on REF paper) = 1.6
[D (on solid paper): a value obtained by placing an OHP sheet on plain paper and measuring the reflection density of the yellow solid image portion D (on REF paper): placing an OHP sheet on plain paper and reflecting the solid white portion (non-image portion) Concentration measured value)

For reflection density measurement, X-rite 504 was used, and yellow density was measured.
The value of OHP transmittance was calculated from the following equation using the above yellow OHP image.

OHP permeability (%) = {D (yellow solid) / D (REF)} × 100
[D (Yellow Solid): An OHP sheet placed on the black portion of the calibration plate of X-rite 404 and the reflection density as a black density in the yellow solid image portion was measured. D (REF): Black of the calibration plate of X-rite 404 (Measurement of reflection density as black density in a solid white part (non-image part) with an OHP sheet on the part)

  X-rite 504 was used for reflection density measurement. The obtained OHP permeability was evaluated according to the following evaluation criteria. In this evaluation, when the transmittance of the yellow solid image is high, the black density of the black portion of the calibration plate is strongly observed. On the other hand, when the transmittance of the yellow solid image is low, the black portion of the calibration plate is observed. This is based on the fact that the black density is observed to be weak.

A: 90% or more B: 80% or more and less than 90% C: 70% or more and less than 80% D: 50% or more and less than 70% E: Less than 50%

[Color unevenness]
A color copying machine CLC-1000 (manufactured by Canon) was used to create a superimposed image of yellow and cyan images on A4 paper. At this time, for the formation of a cyan image, a comparative cyan toner used for measurement of a development contrast difference described later was used. The toner amount on each colored paper is overlapped by 0.3 mg / cm ² to create an unfixed image. In the fixing machine of iRC3200 (manufactured by Canon Inc.), the linear pressure of the rotary pressure member with respect to the rotary heating member is 784 N / Adjusted to m and fixed. The green image obtained by fixing was evaluated according to the following evaluation criteria.

A: Uniform green and excellent.
B: Good with almost no cyan color tone.
C: Cyan and green gradations are partially observed.
D: Cyan and green gradations can be seen on the entire surface.
E: Cyan and green gradations are clearly visible on the entire surface.

[Measurement of development contrast difference between yellow toner and cyan toner]
The cyan toner to be compared was prepared as follows. 70 parts by mass of hybrid resin; B. (Pigment blue) 30% by weight of a pigment slurry containing 30 parts by weight of water was removed to some extent, and a paste-like pigment with a solid content of 30% by weight obtained without passing through a drying process (the remaining 70% by weight A water-containing colorant master batch was prepared using 100 parts by weight of water.

  First, the above raw materials were charged into a kneader type mixer, and the temperature was raised under no pressure while mixing. When the temperature reaches about 80 to 100 ° C., the pigment in the aqueous phase is distributed or transferred to the molten resin phase. After confirming this, the mixture is heated and melt-kneaded for 15 minutes at 90 to 100 ° C. To the molten resin phase. Then, once the mixer was stopped and the hot water was discharged, the water was removed by heating and mixing at 120 ° C. for 15 minutes, and the dried cyan master batch (water content 0) was pulverized to about 1 mm by pin milling. 0.7% by mass).

-Hybrid resin 86 parts by mass-Refined normal paraffin (maximum endothermic peak temperature 78 ° C) 4 parts by mass-3,5-di-t-butylsalicylic acid aluminum compound 2 parts by mass-Dry cyan master batch (pigment content 30% by mass) 20 Part by mass A cyan toner was obtained by the same method as the production method of the yellow toner 1 except that the above formulation was used.

  A two-component developer containing a yellow toner is allowed to stand for 18 hours or more in a normal temperature and low humidity environment (23 ° C./5%), and then used with a color copying machine CLC-1000 (manufactured by Canon Inc.). An unfixed image of A4 half-colored yellow solid image was formed on paper and fixed using a fixing machine of iRC3200 (manufactured by Canon Inc.). The development contrast was adjusted so that the reflection density of the yellow solid portion was 1.6, and the development contrast at this time was V (yellow). Similarly, the cyan toner was mixed with a carrier to obtain a two-component developer, and a cyan solid image with adjusted development contrast was prepared. When the development contrast for the cyan toner at this time was V (cyan), the development contrast difference (V) was determined as {V (yellow) −V (cyan)}, and evaluated according to the following evaluation criteria.

A: Less than 10V B: 10V or more, less than 20V C: 20V or more, less than 30V D: 30V or more, less than 40V E: 40V or more

The evaluation results are shown in Table 3. As shown in Table 3, both the L ^* and b ^* values in the toner powder state were high, and the OHP permeability was very good. Further, there was no color unevenness and the initial development contrast was almost the same as that of cyan toner. Further, even after 10,000 sheets were printed, a yellow image was obtained that faithfully reproduced an original document with no fogging, little filming, and no fogging.

<Example 2>
In Example 1, a yellow toner 2 was obtained using the same method as in Example 1 except that the formulation in the second kneading step was changed as follows. As in Example 1, the resulting yellow toner 2 and carrier were mixed to prepare a two-component developer, and various evaluations were made in the same manner as in Example 1. As shown in Table 3, the color unevenness was inferior. It was a good result.

・ Hybrid resin 83.5 parts by mass ・ Purified normal paraffin (maximum endothermic peak temperature 78 ° C.) 4 parts by mass ・ 3,5-di-t-butylsalicylic acid aluminum compound 2 parts by mass ・ Water-containing yellow masterbatch (pigment content 30% by mass) ) 30 parts by mass

<Example 3>
In Example 1, a yellow toner 3 was produced using the same method as in Example 1 except that the first kneading step was changed as follows.
55 parts by mass of hybrid resin and P.I. Y. 74 was charged into a kneader type mixer using 30 parts by mass and further 20 parts by mass of distilled water, and the temperature was raised under no pressure while mixing. Thereafter, a water-containing yellow masterbatch was produced in the same manner as in Example 1. This water-containing yellow masterbatch had a water content of 15% by mass, a pigment content of 30% by mass and a resin content of 55% by mass.

  A yellow toner 3 was obtained in the same manner as in Example 1 except that the water-containing yellow masterbatch was used. When various evaluations were made in the same manner as in Example 1, good results were obtained although the OHP permeability was slightly inferior, as shown in Table 3.

< Reference Example 4>
In Example 3, as shown in Table 2, a polyester resin was used instead of the hybrid resin in the first kneading step, and 56.25 parts by mass of the polyester resin and styrene-acrylic resin were used instead of the hybrid resin in the second kneading step. A yellow toner 4 was obtained in the same manner as in Example 3 except that 30 parts by mass, a pigment having a different particle diameter was used, and the kneading resin temperature was Tm + 20 ° C. When various evaluations were performed in the same manner as in Example 1, good results were obtained although the OHP permeability was inferior as shown in Table 3.

< Reference Example 5>
A yellow toner 5 was obtained in substantially the same manner as in Reference Example 4 except that the colorant was changed to Pigment Yellow 73 having the following structure in Reference Example 4. When various evaluations were performed in the same manner as in Example 1, good results were obtained although the OHP permeability was inferior as shown in Table 3.

<Comparative example 1>
As shown in Table 2, a dry masterbatch was prepared as follows using a dry pigment without using water in the first kneading step. 70 parts by mass of hybrid resin and P.I. Y. 30 parts by mass of 73 was charged into a kneader-type mixer, heated while being not pressurized while being mixed, and melted and kneaded at 90 to 110 ° C. for 30 minutes to sufficiently transfer the pigment. Then, it was cooled and pulverized to about 1 mm by pin mill pulverization to obtain a dry yellow masterbatch. A yellow toner 6 was obtained in substantially the same manner as in Reference Example 5 except that this dry yellow masterbatch was used and the kneading resin temperature was Tm + 40 ° C. The obtained yellow toner 6 was evaluated in the same manner as in Example 1. As shown in Table 3, the difference in OHP transmittance and development contrast was considerably poor.

<Comparative example 2>
In Reference Example 5, as shown in Table 2, a styrene-acrylic resin was used instead of the polyester resin in the first kneading step, and a styrene-acrylic resin was used instead of the mixed resin in the second kneading step. Otherwise, yellow toner 7 was obtained in substantially the same manner as in Reference Example 5. The obtained yellow toner 7 was evaluated in the same manner as in Example 1. As shown in Table 3, the charge rise rate of the classified product, the charge change before and after the endurance use, and fogging were considerably poor.

<Comparative Example 3>
In Reference Example 5, yellow toner 8 was obtained in substantially the same manner as Reference Example 5 except that pigments having different particle diameters were used as shown in Table 2. The obtained yellow toner 8 was subjected to various evaluations in the same manner as in Example 1. As shown in Table 3, the OHP transmittance was poor.

<Comparative example 4>
Reference Example 5, except that to prepare a dried masterbatch dry pigment without using water as shown in Table 2 were prepared and by adding a second 10 parts of water in the kneading step, substantially the later Similarly, yellow toner 9 was obtained. The same dry masterbatch as that obtained in Comparative Example 1 was used. The obtained yellow toner 9 was subjected to various evaluations in the same manner as in Example 1. As shown in Table 3, the OHP transmittance and the development contrast difference were poor.

<Comparative Example 5>
As shown in Table 2, the first kneading step was not carried out, and the second kneading step was carried out with the following formulation to produce yellow toner 10. At this time, the kneading resin temperature was Tm + 20 ° C.

-Polyester resin 70 parts by mass-Styrene-acrylic resin 30 parts by mass-Purified normal paraffin (maximum endothermic peak temperature 78 ° C) 4 parts by mass-3,5-di-t-butylsalicylic acid aluminum compound 2 parts by mass Y. No. 73 paste pigment (solid content 30% by mass) 25 parts by mass

  When the obtained yellow toner 10 was visually observed, color unevenness was confirmed, and it was considered that poor dispersion of the colorant occurred. In addition, since the color unevenness was so remarkable that it can be visually judged, no other evaluation was performed.

<Comparative Example 6>
In Comparative Example 1, as shown in Table 2, yellow toner 11 was prepared in substantially the same manner as Comparative Example 1 except that 3 parts by mass of dehydroabiethylamine was added as an additive to the first kneading step. Obtained. The obtained yellow toner 11 was subjected to various evaluations in the same manner as in Example 1. As shown in Table 3, the filming and the charge rising rate of the classified product, and the charge change and fogging after durability were worsened. became.

<Comparative Example 7>
In Reference Example 5, as shown in Table 2, Pigment Ye having the following structure was used as a pigment.
A yellow toner 12 was obtained in substantially the same manner as in Reference Example 5 except that the color toner was changed to low 174. When various evaluations were made in the same manner as in Example 1, as shown in Table 3, the difference in OHP transmission and development contrast was poor.

<Example 6>
An image was formed by a one-component development method using yellow toner 1 and cyan toner, and evaluated. The device used was LBP-2510 (manufactured by Canon Inc.). The OHP transmittance, color unevenness, filming, and development contrast difference were good in the A evaluation as in Example 1. In addition, the change in charge and fogging after the durability of 3000 sheets were good in the B evaluation.

<Example 7>
A magenta toner was prepared in the same manner as the cyan toner except that the pigment was changed to Pigment Red 57: 1 in the method for producing the cyan toner for comparison used in the measurement of the development contrast difference. Using the obtained magenta toner, cyan toner and yellow toner 1 and with the same power supply for each color developer, an unfixed image was created with CLC-1000 (Canon Inc.), and iRC3200 (Canon Inc.) When the toner was fixed by the fixing machine ()), the reflection density of each color was 1.6 ± 0.05, and there was no problem with the same power source.

Explanatory drawing of the device that measures the triboelectric charge

Explanation of symbols

52 Measuring Container 53 Screen 54 Lid 51 Suction Machine 55 Vacuum Gauge 56 Air Volume Control Valve 57 Suction Port 58 Condenser 59 Electrometer

Claims (2)

A yellow toner having toner particles containing a binder resin and a colorant,
The binder resin contains at least a polyester unit;
The colorant is C.I. I. Pigment Yellow 74,
When the toner particles have a binder resin and a colorant in the presence of water and the softening point temperature of the binder resin is Tm (° C.), the temperature of the kneaded product immediately after being discharged from the kneader is It is melt-kneaded under the condition of Tm + 10 ° C. or less,
The toner yellow toner lightness ^{L *} in the powder state satisfy ^{L *} ≧ 89.2, and chromaticity ^{b *} is characterized by satisfying the 110.2 ≦ b ^* <120. The colorant has a median particle size D of 40 to 100 nm or less and a particle frequency D150 having a particle size of 150 nm or more in a particle size distribution based on the number of colorants when the binder resin and the colorant are mixed. The yellow toner according to claim 1, wherein the yellow toner is% or less.

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