JP2005141081A - Method for manufacturing toner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a toner by which a toner containing uniformly and finely dispersed colorant particles and having high transparency and color reproducing property is obtained. <P>SOLUTION: When the toner is manufactured, in a first melt kneading step in which a mixture including at least a first binder resin, a colorant and water is heated and kneaded to obtain a first kneaded material and the amount of free water in the first kneaded material is adjusted to a specific amount to obtain a colorant masterbatch, the colorant masterbatch is prepared as a water-containing colorant masterbatch having a water content of 2-25 mass%. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method for producing toner used for development in an image forming method such as an electrophotographic method, an electrostatic recording method, an electrostatic printing method, or a toner jet method.

  When the electrophotographic toner is produced by a pulverization method, it is obtained by mixing a binder resin, a colorant and, if necessary, a release agent, a charge control agent, etc., and melt-kneading, pulverizing and classifying. Furthermore, if necessary, a fluidity-imparting agent such as silica may be externally added, or spheronization may be performed after classification to improve fluidity, developability, and transferability.

  On the other hand, a full-color copying machine has four image carriers and an endless intermediate transfer member, and forms an electrostatic charge image on each image carrier, and the formed electrostatic charge images are cyan toner and magenta toner. , Using yellow toner and black toner, and developing by superimposing the toners of each color using the subtractive color mixing action, and finally developing the toner image of each color formed on the transfer material such as plain paper or OHP sheet The toner image superimposed on the transfer material is fixed on the transfer material to form a desired color image. In recent years, the demand for toner quality for full-color images has been increasing.

  In order to meet these requirements, it is indispensable that the components such as the colorant, the release agent, and the charge control agent are uniformly and finely dispersed in the binder resin in the toner. High dispersion of the agent is important.

  This is because when used as a full-color toner, the upper toner layer must have transparency that does not interfere with the color of the lower toner layer when the colors are mixed in order to superimpose the toner and express the desired color. Because. When the dispersion of the colorant is poor and the transparency is low, the color of the lower toner layer does not appear, so the desired color reproduction cannot be achieved, and the transparency of the toner becomes low and the image on the OHP sheet is projected. The chromaticity of the projected image changes, and the target color cannot be obtained.

  Further, if the colorant is not uniformly dispersed in the binder resin or is dispersed as a large aggregate, toners having different colorant contents are produced. In such a case, the colorant is exposed on the toner surface, filming occurs, the charge amount distribution becomes broad and developability deteriorates, and transferability and fixability are also adversely affected.

  In order to improve the dispersibility of the colorant and improve the transparency of the toner, it is necessary to reduce the average particle diameter of the colorant in the toner. When the average particle diameter of the colorant is large, the light transmittance of the obtained color image is poor, and it becomes difficult to obtain a desired color when forming the color image. In general, when a pigment is used, primary particles tend to aggregate when dried or heated after synthesis, and problems with transparency tend to occur. Based on this idea, for example, a method of preventing agglomeration by using the paste in a water-containing paste state without drying it, or a different raw material having a polar group introduced when the pigment is synthesized by a coupling reaction. A method for improving the transparency of a pigment by mixing a small amount has been proposed (see, for example, Patent Documents 1 to 3).

  However, it is not possible to completely prevent the pigment from aggregating only by using the pigment in the paste state, and the method of mixing different raw materials into which polar groups are introduced improves the dispersion, but the color of the pigment itself is improved. There is a problem because will change.

In addition, there is an example in which a water-containing paste pigment containing a large amount of water is used for melt kneading (see, for example, Patent Document 4). Therefore, there is a problem that it cannot be sufficiently mixed with other raw materials.
JP-A-6-161154 Japanese Patent Laid-Open No. 8-234489 JP 2000-63694 A JP 09-258487 A

  An object of the present invention is to provide a toner manufacturing method that solves the problems in the above-described conventional technology and enables the colorant to be uniformly and finely dispersed in the toner.

  As a result of intensive studies, the present inventors have obtained a colorant masterbatch for toner production in the step of obtaining a colorant masterbatch, and using the colorant masterbatch as a water content colorant masterbatch having a specific water content for use in toner production. Since the colorant particles can be uniformly and finely dispersed in the toner, it has been found that a toner having high transparency and color reproducibility can be obtained, and the present invention has been achieved.

That is, the present invention is as follows.
(1) A mixture containing at least a first binder resin, a colorant and water is heat-kneaded to obtain a first kneaded product, and a moisture content so that the first kneaded product has a moisture content of 2 to 25% by mass. A first melt-kneading step to obtain a water-containing colorant master batch by adjusting
A second melt-kneading step of melt-kneading a toner raw material mixture containing at least a second binder resin and the water-containing colorant master batch to obtain a second kneaded product;
And a pulverizing step of pulverizing the second kneaded product.
(2) In the first melt-kneading step, a water-containing colorant master batch is obtained by adjusting the water content so that the water content of the first kneaded product is 3 to 20% by mass (1) Toner production method.
(3) The toner production method according to (1) or (2), wherein the colorant and water in the first melt-kneading step are paste pigments.
(4) The toner production method according to (1) or (2), wherein, in the first melt-kneading step, the colorant is a dry powder pigment.
(5) In the first melt-kneading step, the temperature (Tmix ₁ ) of the first kneaded product is 80-1
The toner production method according to any one of (1) to (4), wherein the temperature is 20 ° C.
(6) The method for producing a toner according to any one of (1) to (5), wherein the colorant in the water-containing colorant master batch has a volume average particle diameter Dm of 5 to 300 nm.
(7) The method for producing a toner according to any one of (1) to (6), wherein the first binder resin has a softening point temperature (Tm ₁ ) of 80 to 120 ° C.
(8) The method for producing a toner according to any one of (1) to (7), wherein the second binder resin has a softening point temperature (Tm ₂ ) of 85 to 135 ° C.
(9) When the second kneaded material temperature in the second melt-kneading step is Tmix ₂ , the following equation is satisfied with respect to the softening point temperature (Tm ₂ ) of the second binder resin: The toner production method of any one of (1) to (8).
Tmix ₂ ≦ Tm ₂ +30 (° C.)
(10) The method for producing a toner according to any one of (1) to (9), wherein the colorant in the toner has a volume average particle diameter Dt of 10 to 500 nm.
(11) When the volume average particle diameter of the colorant in the water-containing colorant master batch is Dm and the volume average particle diameter of the colorant in the toner is Dt, the following formula is satisfied (1) The toner production method of any one of (10).
Dt / Dm <2.5
(12) In the first melt-kneading step, the ratio between the first binder resin and the colorant is 90:10 to 40:60 in terms of solid mass, (1) to ( 11) The toner production method according to any one of 11).
(13) In the first melt-kneading step, the mass of water is 6 to 400 parts by mass with respect to 100 parts by mass of the solid content of the colorant. (1) to (12) A method for producing any toner.

  According to the present invention, since the colorant particles can be uniformly and finely dispersed in the toner, it is possible to provide a toner manufacturing method in which a toner having high transparency and color reproducibility can be obtained.

In the method for producing a toner of the present invention, a mixture containing at least a first binder resin, a colorant and water is kneaded by heating to obtain a first kneaded product, and the first kneaded product has a water content of 2 to 25% by mass. A first melt-kneading step to obtain a water-containing colorant master batch by adjusting the amount of water so that
A second melt-kneading step of melt-kneading a toner raw material mixture containing at least a second binder resin and the water-containing colorant master batch to obtain a second kneaded product;
A pulverizing step of pulverizing the second kneaded product.

  The “water-containing colorant masterbatch” used in the present invention is a colorant masterbatch containing moisture. In the present invention, it is obtained by heating and kneading at least the first binder resin, the colorant, and water. It is a water-containing colorant masterbatch (hereinafter referred to as “water-containing MB”) obtained by adjusting the water content of the first kneaded product to a water content of 2 to 25% by mass.

  The water-containing MB is obtained, for example, as follows in the first melt-kneading step. A mixture containing at least a first binder resin, a colorant and water is charged into a kneader or a mixer, heated and kneaded while mixing under non-pressure or under pressure, and the first binder resin is melted and heated. The first binder resin, that is, the first kneaded product is obtained by distributing or transferring the colorant to the molten resin phase, the phase-separated water is removed by decantation, and the first binder resin and the colorant Obtained by melting and kneading and evaporating and removing moisture. In addition, about the removal method of the water | moisture content from the 1st kneaded material, although the method by the decantation and the evaporation removal of a water | moisture content was illustrated above, this invention is not limited to it.

  In the first melt-kneading step, when the first binder resin and the colorant are kneaded, the ratio of the first binder resin and the colorant in terms of solid mass is 90:10 to 40:60. The ratio is preferably 85:15 to 45:55.

  When the ratio of the colorant to the first binder resin is smaller than 10% by mass, a large amount of the first binder resin must be charged into the kneading machine with respect to the colorant, and the first kneaded product is colored. The segregation of the agent tends to occur, and in order to bring this into a uniform system, the kneading time must be set long. This is not preferable because an extra load is applied to the first binder resin, and the first binder resin characteristics may change.

  When the ratio of the colorant to the first binder resin is more than 60% by mass, the transition of the colorant particles to the first binder resin is not performed smoothly, and at the time of melt-kneading after the transition of the colorant particles. However, the kneaded product does not show a uniform molten state, and as a result, high dispersibility may not be obtained.

In the present invention, the first kneaded product temperature Tmix ₁ (° C.) in the first melt-kneading step is preferably 80 to 120 ° C., more preferably 80 to 110 ° C.

When the first kneaded material temperature Tmix ₁ (° C.) is lower than 80 ° C., the first binder resin is insufficiently melted, and the distribution or transfer of the colorant from the aqueous phase to the molten resin phase is smooth. It may be difficult to disperse a uniform colorant. When the first kneaded material temperature Tmix ₁ (° C.) is higher than 120 ° C., the colorant tends to aggregate during melt-kneading, and the colorant particle size in the water-containing MB may increase.

  In the present invention, the volume average particle diameter Dm of the colorant in the water-containing MB is preferably 5 to 300 nm, more preferably 5 to 200 nm, and still more preferably 5 to 150 nm.

  When Dm is larger than 300 nm, the dispersibility of the colorant is poor, and it may be difficult to sufficiently mix with other materials in the second melt-kneading step. As a result, the dispersibility of the colorant also decreases in the toner, making it difficult to obtain a toner having high transparency and color reproducibility.

  On the other hand, when Dm is smaller than 5 nm, the toner is excellent in dispersibility and transparency in the second melt-kneading step, but the light resistance may be lowered.

  The water content MB in the present invention has a water content of 2 to 25% by mass, preferably 3 to 20% by mass, and more preferably 5 to 18% by mass. The water-containing MB in the present invention is obtained, for example, by the above-described production method, but unlike conventional colorant master batches, the water content is not removed more than necessary, and the water-containing MB has a water content of 2 to 25% by mass. Thus, the colorant can be uniformly and finely dispersed in the toner. The reason for this is not clear, but is estimated as follows.

  First, in the step of melt-kneading the toner raw material mixture containing at least the second binder resin and the water-containing MB to obtain the second kneaded product (second melt-kneading step), a large amount of moisture is contained in the water-containing MB. Therefore, the presence of water between the colorant particles prevents aggregation of the colorant particles. Furthermore, the water that permeates the aggregates of the colorant particles that are partly present expands due to the heat in the second kneading and kneading step, breaks the aggregates, and makes a good dispersion.

  Secondly, the second kneaded product becomes high in temperature when the toner raw material mixture has a strong share during the second melt-kneading and the water-containing MB self-heats, and when necessary, is heated from the outside. Since water is removed as heat of vaporization when water evaporates, it is possible to prevent strong adhesion and aggregation due to heat between the colorant particles.

  Third, water vapor is generated during the second melt-kneading and the second kneaded product expands, increasing the pressure in the kneader to increase the shear, generating a stronger shearing force, It is very effective for dispersing all components contained in the kneaded material including the colorant particles.

  In the present invention, when the water content of the water-containing MB exceeds 25% by mass, the water content is too much, so the adhesive force of the water-containing MB is too strong, and it is fused to a manufacturing apparatus such as a Henschel mixer or the fluidity is reduced. Large aggregates may be generated in the toner raw material mixture, which is not preferable. In addition, when the water content is less than 2% by mass, the above-described effects cannot be expected. In addition, in the first melt-kneading process, in order to obtain a water-containing MB with adjusted moisture, it remained in the master batch. When heating and drying under normal pressure or reduced pressure to remove a small amount of water, the dispersed colorant particles cause strong aggregation, and in the subsequent second melt-kneading step, the colorant is again good. It is difficult and undesirable to disperse.

In the first melt-kneading step of the toner production method of the present invention, it is preferable to use a paste pigment as “colorant and water”. The “paste pigment” refers to a pigment particle in a state where the pigment particles are present without passing through the drying step in a pigment particle manufacturing step in which a pigment is previously prepared for use in the manufacture of a toner as a colorant. In this state, since the pigment particles are almost in the form of primary particles, a water-containing MB having better pigment dispersibility can be obtained after the first melt-kneading step. The paste pigment used in the present invention may have any water content, and the water content is not limited, but is preferably 40 to 95% by mass, more preferably 50 to 95% by mass. In addition, when the moisture content of the paste pigment is less than 40% by mass, water may be added so as to fall within the above range.
The water content of the paste pigment can be adjusted by a usual method.

Further, when a paste pigment is used in the first melt-kneading step, water may be further added.
In the first melt-kneading step, it is also possible to use a dry powder pigment as a colorant. In that case, water is added in addition to the first binder resin and the dry powder pigment, In the first melt-kneading step, water-containing MB is obtained as a water mixture. In order to perform kneading more sufficiently, for example, the kneading time and the number of times can be increased in the first melt-kneading step.

  In the first melt-kneading step, the mass of water is preferably 6 to 400 parts by mass, more preferably 10 to 300 parts by mass with respect to 100 parts by mass of the solid content of the colorant. In the first melt-kneading step, when the mass of water is less than 6 parts by mass with respect to 100 parts by mass of the solid content of the colorant, it may be difficult to obtain a water-containing MB containing desired moisture. Moreover, when there are more masses of water than 400 mass parts, distribution or transfer to a molten resin phase does not occur smoothly, and it may become difficult to disperse a uniform colorant.

When a dry powder pigment is used as the colorant, it is possible to improve the dispersibility of the pigment particles by increasing the number of kneading times. However, since the first binder resin is subjected to mechanical stress, The molecular chain in the binder resin is likely to be broken, so that the storage stability of the toner is lowered, and a problem that a part of the toner is easily carried to the fixing roller due to the durability of a large number of sheets also occurs. Therefore, the method using a paste pigment is more preferable than the method using a dry powder pigment from the viewpoint of durability of a large number of images.
As the “colorant and water”, a paste pigment and a dry powder pigment may be used, and water may be further added thereto. It is preferable that the ratio of the solid content of the colorant and the mass of water at this time is as described above.

  Examples of the colorant used in the present invention include the following.

  Examples of the magenta colorant include C.I. I. Pigment Red 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 21, 22, 23, 30, 31, 32, 37, 38, 39, 40, 41, 48, 49, 50, 51, 52, 53, 54, 55, 57, 58, 60, 63, 64, 68, 81, 83, 87, 88, 89, 90, 112, 114, 122, 123, 150, 163, 202, 206, 207, 209, C.I. I. Pigment violet 19, C.I. I. Examples thereof include magenta color pigments such as Vat Red 1, 2, 10, 13, 15, 23, 29, and 35.

Although the above pigment may be used alone, it is more preferable from the viewpoint of the image quality of a full color image to improve the sharpness by using a dye and a pigment together. Examples of the magenta dye include C.I. I. Solvent Red 1, 3, 8, 23, 24, 25, 27, 30, 49, 2, 881, 83, 84, 100, 109, 121, C.I. I. Disper thread 9, C.I. I. Solvent Violet 8, 13, 14, 21, 27, C.I. I. Oil-soluble dyes such as disperse violet 1, C.I. I. Basic Red 1, 2, 9, 12, 13, 14, 15, 17, 18, 22, 23, 24, 27, 29, 32, 34, 35, 36, 37, 38, 39, 40, C
. I. Basic dyes such as basic violet 1,3,7,10,14,15,21,25,26,27,28 are listed.

  Examples of cyan colorants include C.I. I. Pigment blue 2, 3, 15, 16, 17, C.I. I. Bat Blue 6, C.I. I. Acid Blue 45 or a coloring pigment for cyan such as a copper phthalocyanine pigment in which 1 to 5 phthalimidomethyl groups are substituted on the phthalocyanine skeleton.

  Examples of the colorant for yellow include C.I. I. Pigment Yellow 1, 2, 3, 4, 5, 6, 7, 10, 11, 12, 13, 14, 15, 16, 17, 23, 65, 73, 74, 83, 180, C.I. I. Examples thereof include yellow colored pigments such as vat yellow 1, 3, 20 and the like.

  The amount of the colorant used is 1 to 10 parts by mass, preferably 3 to 8 parts by mass with respect to 100 parts by mass of the binder resin in the toner.

  As the black colorant, carbon black, iron oxide, and those which are toned in black using the yellow / magenta / cyan colorant shown above can be used.

The first binder resin used in the present invention has a softening point temperature Tm ₁ (° C.) of preferably 80 to 120 ° C., more preferably 85 to 110 ° C.

When the softening point temperature Tm ₁ of the first binder resin is higher than 120 ° C., the melting of the first binder resin becomes insufficient, and the distribution or transfer of the colorant from the aqueous phase to the molten resin phase occurs smoothly. It can be difficult. When the softening point temperature Tm ₁ of the first binder resin is lower than 80 ° C., the first binder resin is sufficiently melted and the distribution or transfer of the colorant to the molten resin phase proceeds smoothly. In some cases, the blocking resistance of the resulting toner may be reduced.

  The second melt kneading step in the present invention is a step of melt kneading the toner raw material mixture containing the water-containing MB and the second binder resin.

The second binder resin used in the present invention has a softening point temperature Tm ₂ (° C.) of preferably 85 to 135 ° C., more preferably 90 to 120 ° C.

When the softening point temperature Tm2 of the _second binder resin is higher than 135 ° C., the obtained toner has excellent offset resistance, but when used in an image forming method, the fixing set temperature must be increased. Even if the degree of pigment dispersion can be controlled, the surface smoothness of the obtained toner in the image area is greatly reduced, and it is difficult to obtain high color reproducibility.

When the softening point temperature Tm2 of the _second binder resin is lower than 85 ° C., the obtained toner may cause a decrease in blocking resistance, and it is difficult to obtain high offset resistance.

Further, when the kneaded material temperature in the second melt-kneading step of the present invention is Tmix ₂ (° C.), Tmix ₂ ≦ Tm ₂ +30 with respect to the softening point temperature Tm ₂ (° C.) of the second binder resin. (° C.), more preferably Tmix ₂ ≦ Tm ₂ +25 (° C.), and further preferably Tmix ₂ ≦ Tm ₂ +20 (° C.).

In the present invention, when Tmix ₂ > Tm ₂ +30 (° C.), it is insufficient to lower the temperature of the second kneaded product only by the cooling effect due to the heat of vaporization of the water contained in the second kneaded product. . For this reason, the viscosity of the second kneaded product is lowered, and a strong share is not applied, and it is difficult to sufficiently disperse the raw materials. Furthermore, aggregation of the colorant particles may occur at a high temperature.

  In the present invention, the volume average particle diameter Dt of the colorant in the toner is preferably 10 to 500 nm, more preferably 10 to 300 nm, and still more preferably 10 to 200 nm. When Dt is larger than 500 nm, transparency is lowered and it is difficult to obtain high color reproducibility, and when Dt is smaller than 10 nm, the toner is excellent in transparency but light resistance may be lowered. .

  Further, in the present invention, Dt / Dm <2.5, more preferably Dt / Dm <2.3, where Dm and Dt are the volume average particle diameters of the colorant in the water-containing MB and in the toner, respectively. It is good to be.

In the present invention, when Dt / Dm> 2.5, in the second melt-kneading step, the colorant particles are aggregated and the dispersibility is insufficient, so that the transparency tends to decrease.
In the present invention, in the second melt-kneading step, by using the water-containing MB having a water content of 2 to 25% by mass, the volume average particle diameter Dm of the colorant in the water-containing MB is adjusted to 5 to 300 nm. Aggregation of the colorant particles can be suppressed, and the volume average particle diameter Dt of the colorant in the toner can be in the above range.

  In the present invention, known colorant dispersants can be used in the pigment production step and the first melt-kneading step. Examples of the dispersant include higher fatty acid alkali salts, alkyl sulfate salts, alkyl sulfonate salts, alkyl aryl sulfonate salts, sulfosuccinate ester salts, higher amine halogenates, alkyl pyridinium halides, quaternary ammonium salts, polyethylene glycols. There are surfactants such as alkyl ethers, polyerylene glycol fatty acid esters, sorbitan fatty acid esters, fatty acid monoglycerides, amino acids, olefinic hydrocarbons, rosin derivatives, varnishes, polymer dispersants and the like.

  Next, the second melt-kneading step will be described in detail.

  First, a predetermined amount of at least a second binder resin and the above-mentioned water-containing MB are weighed and blended as a toner raw material mixture 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.

  Further, the toner raw material mixture mixed as described above is melt-kneaded to melt the second binder resin, and a second kneaded material in which a colorant and the like are dispersed is obtained. In the second 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 (Toshiba Machine Co., Ltd.), twin screw extruder (manufactured by Kay CK Co., Ltd.), co-kneader (manufactured by Buss), etc. are generally used.

  Further, a second kneaded product (hereinafter also referred to as “colored resin composition”) obtained by melt-kneading the toner raw material mixture is rolled by a two-roll roll after the melt-kneading and cooled by water cooling or the like. It is preferable to cool through a process.

The cooled product of the colored resin composition obtained above is then pulverized to a desired particle size in the pulverization step. In the pulverization process, first, coarse pulverization is performed with a crusher, a hammer mill, a feather mill or the like, and further, an IDS type pulverizer (manufactured by Nippon Pneumatic Industry Co., Ltd.) or a crypt of a mechanical pulverizer. It is pulverized by Ron System (manufactured by Kawasaki Heavy Industries, Ltd.), Super Rotor (manufactured by Nissin Engineering Co., Ltd.), etc.

  After that, if necessary, classification is performed using a classifier such as a classifier such as an inertia class elbow jet (manufactured by Nippon Steel Mining Co., Ltd.) or a centrifugal force class turboplex (manufactured by Hosokawa Micron Co., Ltd.). Through a classification step, a classified product (toner particles) having a weight average particle size of 3 to 11 μm is obtained. Furthermore, if necessary, a surface modification (spheronization treatment) step is performed, for example, using a hybridization system (manufactured by Nara Machinery Co., Ltd.) or a mechano-fusion system (manufactured by Hosokawa Micron Corporation). To obtain a classified product (toner particles).

  Further, a classified product (toner particles) may be obtained through a sieving step using a sieving machine such as a wind-type sieving high voltor (manufactured by Shin Tokyo Machine Co., Ltd.). Further, it may include a step of externally adding an external additive, and a predetermined amount of toner particles as a classified product and an external additive such as silica and titanium oxide are blended to form a powder such as a Henschel mixer or a super mixer. A toner can be obtained by stirring and mixing using a high-speed stirrer that gives a shearing force as an external additive.

  As the binder resin for toner used in the present invention, a known thermoplastic resin can be used. In the present invention, the first binder resin and the second binder resin may be the same or different, and specific examples are shown below, but are not particularly limited. .

  For example, styrenes such as styrene, chlorostyrene, and α-methylstyrene; monoolefins such as ethylene, propylene, butylene, and isobutylene; vinyl esters such as vinyl acetate, vinyl propionate, vinyl benzoate, and vinyl butyrate; acrylic acid Esters of α-methylene aliphatic monocarboxylic acids such as methyl, ethyl acrylate, butyl acrylate, octyl acrylate, dodecyl acrylate, phenyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, dodecyl methacrylate Vinyl ethers such as vinyl methyl ether, vinyl ethyl ether and vinyl butyl ether; homopolymers or copolymers of vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone and vinyl isopropenyl ketone;

  Natural and synthetic waxes, polyester resins, polyamide resins, epoxy resins, polycarbonate resins, polyurethane resins, silicone resins, fluorine resins, petroleum resins, and the like can be used, and polyester resins are preferably used.

  When a polyester resin is used as the binder resin, those using an alcohol component and a carboxylic acid component such as a carboxylic acid, a carboxylic acid anhydride, or a carboxylic acid ester as raw material monomers can be used.

  Specifically, for example, as a divalent 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 -Alkylene oxide adducts of bisphenol A such as bis (4-hydroxyphenyl) propane, polyoxypropylene (6) -2,2-bis (4-hydroxyphenyl) propane, ethylene glycol, diethylene glycol, triethylene glycol, 1, 2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, Opentyl glycol, 1,4-butenediol, 1,5-pentanediol, 1,6-hexanediol, 1,4-cyclohexanedimethanol, dipropylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, bisphenol A And hydrogenated bisphenol A.

  Examples of the trivalent or higher alcohol component 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 carboxylic 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; And succinic acid or anhydride thereof substituted with 12 alkyl groups or alkenyl groups; unsaturated dicarboxylic acids such as fumaric acid, maleic acid and citraconic acid or anhydrides thereof.

  Moreover, in order to form the polyester resin which has a bridge | crosslinking site | part, a trivalent or more polyvalent carboxylic acid component can also be used for polyester manufacture. Examples of the trivalent or higher carboxylic acid component include 1,2,4-benzenetricarboxylic acid, 1,2,5-benzenetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid, and 2,5,7-naphthalenetricarboxylic acid. Examples thereof include acids, 1,2,4,5-benzenetetracarboxylic acid, and anhydrides and ester compounds thereof. The amount of the trivalent or higher polyvalent carboxylic acid component is preferably 0.1 to 1.9 mol% based on the total monomer.

  Among the above, as the binder resin, in particular, a bisphenol derivative represented by the following general formula (1) is used as a divalent alcohol component, and a divalent or higher carboxylic acid (for example, fumaric acid, maleic acid, maleic anhydride). Acid, phthalic acid, terephthalic acid, trimellitic acid, pyromellitic acid, etc.) or acid anhydrides thereof, or lower alkyl esters thereof as carboxylic acid components, and these polyester resins have good charging characteristics. preferable.

  In the present invention, it is also preferable to use a hybrid resin as the binder resin. The hybrid resin means a resin in which a vinyl polymer unit and a polyester resin unit are chemically bonded. Specifically, a polyester resin unit and a vinyl polymer 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 unit is a trunk polymer and the polyester resin unit is a branch polymer is formed. As the vinyl polymer unit and the polyester resin unit, a vinyl polymer obtained from a vinyl monomer and a polyester resin can be used, respectively.

  In the present invention, the hybrid resin contains a monomer capable of reacting with both in the vinyl polymer and / or polyester resin, and the polymer containing the monomer is present. It is preferable to obtain by carrying out a polymerization reaction. Among the monomers constituting the polyester resin unit, those capable of reacting with the vinyl polymer unit include, for example, unsaturated dicarboxylic acids such as phthalic acid, maleic acid, citraconic acid, and itaconic acid, or anhydrides thereof. . Among the monomers constituting the vinyl polymer unit, those capable of reacting with the polyester resin unit include those having a carboxyl group or a hydroxy group, and acrylic acid or methacrylic acid esters.

  The glass transition temperature (Tg) of the first and second binder resins used in the present invention is preferably 40 to 90 ° C, more preferably 45 to 85 ° C.

  The binder resin used in the present invention has a molecular weight distribution measured by gel permeation chromatography (GPC) having a main peak (Mp) in the region of a molecular weight of 3,500 to 30,000, particularly a molecular weight of 5 , 20,000 to 20,000, and 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 is insufficient. On the other hand, when the main peak is in the region where the molecular weight exceeds 30,000, sufficient low-temperature fixability of the toner 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 second melt-kneading step of the toner production method of the present invention, the toner raw material mixture may contain one or more waxes as a release agent, and examples thereof include the following. Low molecular weight polyethylene, low molecular weight polypropylene, low molecular weight olefin copolymer, aliphatic hydrocarbon wax such as microcrystalline wax, Fischer-Tropsch wax, paraffin wax; oxide of aliphatic hydrocarbon wax such as oxidized polyethylene wax; fat Block copolymer of aromatic hydrocarbon wax; wax mainly composed of fatty acid ester such as carnauba wax, montanic acid ester wax, behenyl behenate; and part or all of fatty acid ester such as deoxidized carnauba wax What you did.

  In addition, a partially esterified product of a fatty acid such as behenic acid monoglyceride and a polyhydric alcohol; a methyl ester compound having a hydroxyl group obtained by hydrogenating vegetable oil and the like, and the like are also used as a release agent. Particularly preferably used waxes as a release agent are paraffin wax, polyolefin wax, Fischer-Tropsch wax, carnauba wax and the like.

  The amount of the wax used in the present invention is 1 to 10 parts by weight, preferably 2 to 8 parts by weight, based on 100 parts by weight of the binder resin in the toner. When the amount is less than 1 part by mass, a considerable amount of heat and pressure must be used in order to come out on the surface of the toner at the time of melting and to exhibit releasability. On the other hand, if the amount exceeds 10 parts by mass, the amount of wax in the toner is too large, resulting in poor transparency and charging characteristics.

  The toner obtained by the production method of the present invention has one or a plurality of endothermic peaks in the temperature range of 30 to 200 ° C. in the endothermic curve in differential thermal analysis (DSC) measurement. The temperature of the endothermic peak is preferably 60 ° C. to 110 ° C., more preferably 70 ° C. to 90 ° C. When the temperature of the maximum endothermic peak is 60 ° C. or less, the blocking characteristics tend to be inferior. When the temperature is 110 ° C. or more, it is difficult to sufficiently perform low-temperature fixing desired from the viewpoint of energy saving, and a load requiring pressure is required even in the fixing configuration. Because.

In the toner of the present invention, a charge control agent of an organometallic compound described below can be used as a toner raw material mixture in the second kneading step. The charge control agent for the organometallic compound is preferably an aromatic carboxylic acid derivative selected from an aromatic oxycarboxylic acid and an aromatic alkoxycarboxylic acid, and a metal compound of the aromatic carboxylic acid derivative. Divalent or higher valent metal atoms are preferred. As divalent ^{metal, Mg 2+, Ca 2+, Sr} 2+, Pb 2+, Fe 2+, Co 2+, Ni 2+, Zn 2+, Cu 2+ , and the like, in particular Zn ²⁺ , Ca ²⁺ , Mg ²⁺ and Sr ²⁺ are preferred. Examples of the trivalent or higher metal include Al ³⁺ , Cr ³⁺ , Fe ³⁺ , Ni ³⁺ and Zr ⁴⁺ . Among these metals, Al ³⁺ and Cr ³⁺ are preferable, and Al ³⁺ and Zr ⁴⁺ are particularly preferable. Specifically, an aluminum compound of di-tert-butylsalicylic acid is particularly preferable as the charge control agent.

The charge control agent used in the present invention is used in an amount of 0.2 to 10 parts by weight, preferably 0.3 to 7 parts by weight, based on 100 parts by weight of the binder resin in the toner. 0.
This is because if the amount is less than 2 parts by mass, the effect of charging rise cannot be obtained, and if the amount is more than 10 parts by mass, the environmental fluctuation increases.

  In the present invention, it is preferable for improving the image quality that a fluidity improver is externally added to the toner particles as an external additive in the step of externally adding the external additive. The fluidity improver is an agent that can be added to the toner particles to increase the fluidity before and after the addition.

  Examples of the fluidity improver include fluorine resin powders such as vinylidene fluoride fine powder and polytetrafluoroethylene fine powder; silica fine powder such as silica fine powder by a wet process, silica fine powder such as silica fine powder by a dry process; Treated silica fine powder whose powder is surface-treated with a treatment agent such as silane coupling agent, titanium coupling agent, silicone oil, etc .; titanium oxide fine powder; alumina fine powder, treated titanium oxide fine powder, treated alumina oxide fine powder, etc. Is mentioned.

A fluidity improver having a specific surface area of 30 m ² / g or more, more preferably 50 m ² / g or more, gives good results by nitrogen adsorption measured by the BET method. The fluidity improver is preferably added in an amount of 0.01 to 8 parts by weight, more preferably 0.1 to 4 parts by weight, based on 100 parts by weight of the toner particles.

  As described above, the external addition of the fluidity improver is performed by sufficiently mixing the fluidity improver and the toner particles with a mixer such as a Henschel mixer. By such a mixing operation, a toner having a fluidity improver on the toner particle surface can be obtained.

  The toner obtained by the production method of the present invention preferably has a weight average particle diameter of 4 to 10 μm, and more preferably 5 to 9 μm.

  When the weight average particle size of the toner is larger than 10 μm, it means that there are few fine particles that can contribute to high image quality, and when used for image formation, a high image density is easily obtained and the toner fluidity is excellent. Although there is a merit, it is difficult to adhere faithfully on the fine electrostatic charge image on the photosensitive drum, the reproducibility of the highlight portion is lowered, and the resolution tends to be lowered. Also, the toner tends to overload the electrostatic charge image more than necessary, and the toner consumption tends to increase.

On the contrary, when the weight average particle diameter of the toner is smaller than 4 μm, the charge amount per unit mass of the toner becomes high, and when used for image formation, the image density is lowered, particularly at low temperature and low humidity. Becomes prominent. This is not suitable for applications with a high image area ratio such as graphic images. When the thickness is smaller than 4 μm, contact charging with a charging member such as a carrier is difficult to be performed smoothly, toner that cannot be sufficiently charged increases, and fogging due to scattering to a non-image portion becomes conspicuous. In order to cope with this, it is conceivable to reduce the diameter of the carrier in order to increase the specific surface area of the carrier. However, in the toner having a weight average particle diameter of less than 4 μm, toner self-aggregation easily occurs, and uniform mixing with the carrier can be performed in a short time. This is difficult to achieve, and fog tends to occur in the continuous toner replenishment durability.
In order to make the toner in the present invention have a weight average particle diameter of 4 to 10 μm, the particle diameter is adjusted in the pulverization step, and the toner having a weight average particle diameter in the range may be classified.

  The toner produced by the production method of the present invention can be applied to a one-component developer and a two-component developer, and the toner produced in the present invention is not limited to this. When used as an agent, the toner is used mixed with a magnetic carrier. Examples of magnetic carriers include iron or surface-oxidized iron; metal particles such as nickel, copper, zinc, cobalt, manganese, chromium, magnesium, rare earth; alloy particles thereof; oxide particles thereof; ferrites thereof; A coated carrier in which the surface of magnetic particles is coated with a resin; a magnetic particle-dispersed resin carrier in which these magnetic particles are dispersed in resin particles can be used.

  The coated carrier in which the surface of the magnetic particle is coated with a resin is particularly preferable when used in a developing method in which an AC bias is applied to the developing sleeve. As a coating method, a method of adhering a coating solution prepared by dissolving or suspending a resin as a coating material in a solvent to the surface of the magnetic particles, a method of adhering the magnetic particles and the coating material by mixing with powder, etc. Conventionally known methods can be applied.

  Examples of the resin as a coating material on the surface of the magnetic particles 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 magnetic particles.

  The 50% average particle diameter of the magnetic carrier is preferably 10 to 100 μm, and more preferably 20 to 70 μm.

  When a two-component developer is prepared by mixing the toner produced in the present invention and a magnetic carrier, the mixing ratio is usually preferably 2 to 15% by mass of the toner in the developer. It is preferable for obtaining the result, and more preferably 4 to 13% by mass.

  The image forming method for forming a color image using the toner produced according to the present invention can be realized by a known apparatus or means in this technical field. For example, an image forming method using an image forming apparatus in which a plurality of developing devices are installed on one image carrier, or a toner image formed on an image carrier with a plurality of developing devices installed on different image carriers. Examples of the image forming method include a tandem image forming apparatus in which images are sequentially transferred onto a transfer material, but are not particularly limited.

  Further, when the toner image formed on the image carrier is transferred to a transfer material, an image forming method using an image forming apparatus that directly transfers the toner image from the image carrier to the transfer material may be used. An image forming method using an image forming apparatus that transfers a toner image on a body to an intermediate transfer member and transfers the toner image from the intermediate transfer member to a transfer material may be used.

  Hereinafter, measurement methods suitable for measuring the physical properties of the resin used in the present invention and the toner in the present invention will be described below.

(1) Measurement of the molecular weight of the binder resin The column was stabilized in a 40 ° C. heat chamber, and THF was flowed through the column at this temperature as a solvent at a flow rate of 1 ml per minute, and about 100 μl of the THF sample solution was injected and measured. To do. An RI (refractive index) detector is used as the detector. As the column, it is preferable to use a combination of a plurality of commercially available polystyrene gel columns. For example, combinations of shodex GPC KF-801, 802, 803, 804, 805, 806, 807, and 800P manufactured by Showa Denko K.K. TSKgel G1000H (HXL), G2000H (HXL), G3000H (HXL), G4000H (HXL), G5000H (HXL), G6000H (HXL), G7000H (HXL), TSKguard manufactured by Tosoh Corporation
A combination of columns can be given.

  The THF sample solution is prepared as follows. Place the sample in THF and let stand for several hours, then shake well, mix well with THF (until the sample is no longer integrated), and let stand for more than 12 hours. At this time, the immersion time in THF is 24 hours or longer. Thereafter, a sample processing filter (pore size 0.2 to 0.5 μm, for example, available from Mysori Disc H-25-2 manufactured by Tosoh Corporation) can be passed to obtain a THF sample solution for GPC. The sample concentration is adjusted so that the resin component is 0.5 to 5 mg / ml.

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. As a standard polystyrene sample for preparing a calibration curve, for example, one having a molecular weight of about 10 ² to 10 ⁷ manufactured by Tosoh Corporation or Showa Denko Co., Ltd., and at least about 10 standard polystyrene samples should be used. Is appropriate.

(2) Measurement of softening point temperature Tm of binder resin For the measurement of the softening point temperature of the binder resin, a flow tester CFT-500 type (manufactured by Shimadzu Corporation) is used. The sample weighs about 1.0 g of a 60 mesh pass product. This sample is pressed with a load of 100 kg / cm ² for 1 minute using a molding machine.

The pressure sample is subjected to flow tester measurement under the following conditions under normal temperature and humidity (temperature of about 20 to 30 ° C., humidity of 30 to 70% RH) to obtain a temperature-apparent viscosity curve. From the obtained smooth curve, the temperature (= T1 / 2) when the sample flows out by 50% by volume is obtained, and this is defined as the softening point temperature Tm of the resin.

RATE TEMP 6.0 (° C / min)
SET TEMP 50.0 (° C)
MAX TEMP 180.0 (° C)
INTERVAL 3.0 (° C)
PREHEAT 300.0 (seconds)
LOAD 20.0 (kg)
DIE (Diameter) 1.0 (mm)
DIE (Length) 1.0 (mm)
PLUNGER 1.0 (cm ² )

(3) Measurement of kneaded material temperature Digital thermometer HFT-50: temperature sensor BS-21E-0
30 (manufactured by Anritsu Keiki Co., Ltd.) or radiation thermometer R-150 (manufactured by Anritsu Keiki Co., Ltd.) is used.
In the case of the kneaded material coming out from the discharge port of the kneader, the measurement is performed by directly inserting a temperature sensor and setting the kneaded material temperature to a stable value. Further, when kneading with a kneader or the like, a radiation thermometer is used, and the surface temperature is set as the kneaded material temperature.

(4) Measurement temperature curve of DSC curve of toner and binder resin: 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)

The maximum endothermic peak of the toner is measured according to ASTM D3418-82 using a differential scanning calorimeter (DSC measuring device), DCS-7 (manufactured by PerkinElmer) or DSC2920 (manufactured by TA Instruments Japan).
Weigh accurately 5 mg of the measurement sample. It is put in an aluminum pan, and an empty aluminum pan is used as a reference, and measurement is performed at a measurement range of 30 to 200 ° C., a temperature increase rate of 10 ° C./min, and normal temperature and humidity. The glass transition temperature (Tg) of the binder resin is the point of intersection between the base line midpoint and the differential heat curve before and after the endothermic peak of the main peak in the temperature range of 40 to 100 ° C. in the process of temperature rise II. And the glass transition temperature Tg in the present invention.

  The maximum endothermic peak of the toner is the one having the highest height from the base line in the region above the endothermic peak of the glass transition temperature (Tg) of the resin in the process of temperature increase II, or the endothermic peak of the resin Tg. If it is difficult to discriminate overlap with another endothermic peak, the highest endothermic peak of the toner is defined as the highest peak from the maximum peak of the overlapping peak.

(5) Measurement of water content of water-containing MB and paste pigment In the present invention, “water content” refers to the mass-based water content based on the Karl Fischer method, that is, the total weight of water-containing MB or the ratio of water mass to paste pigment, It was determined by measuring the gas at 125 ° C. heating based on the Karl Fischer method (JIS K-0068 moisture vaporization method) using a sample prepared by leaving it at 23 ° C. and 60% RH for 24 hours.

(6) Measurement of volume average particle size of water-containing MB and colorant in toner To 100 mg of sample, 5 ml of THF (tetrahydrofuran) was added and allowed to stand for 24 hours. Is dispersed in THF to prepare a sample. The particle size distribution of the obtained sample is measured using MicrotracUPA (manufactured by Nikkiso Co., Ltd.). By this measurement, the volume average particle diameter of the water-containing MB and the colorant contained in the toner can be obtained.

(7) Measurement of toner particle diameter In the present invention, the average particle diameter of the toner is measured using a Coulter Counter TA-II type (manufactured by Beckman Coulter, Inc.), but Coulter Multisizer (manufactured by Beckman Coulter, Inc.). It is also possible to use. As the electrolytic solution, a 1% NaCl aqueous solution is prepared using primary sodium chloride. For example, ISOTON R-II (manufactured by Coulter Scientific Japan Co., Ltd.) 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 of 2.00 μm or more are measured by using the 100 μm aperture as the aperture by the measuring device. Distribution and 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.

(8) Measurement of specific surface area of fluidity improver The specific surface area is determined according to the BET method by adsorbing nitrogen gas on the sample surface using a specific surface area measuring device Autosorb 1 (manufactured by Yuasa Ionics Co., Ltd.). Is used to calculate the specific surface area.

  EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention concretely, this does not limit this invention at all. In addition, “part” representing the blending amount means “part by mass”.

<Evaluation method>
The printing durability test in the examples was evaluated as follows using the following paper.
Plain paper: CLC color copy paper (basis weight 80 g / cm ² : manufactured by Canon Inc.)
OHP sheet: Transparency sheet CG3700 (manufactured by Sumitomo 3M Limited)

(1) Method for measuring charge rise rate in classified product 3.5 g of classified product and 46.5 g of magnetic ferrite carrier particles (average particle size 45 μm: Mn-Mg ferrite) surface-coated with silicone resin were weighed and 50 ml of polyethylene Place in a sample bottle and leave at room temperature and low humidity (23 ° C / 5%) for 18 hours or longer. Then, a shaker for 2 minutes at 3.3 s ^-1 and a shaker for 30 minutes are made using a Yayoi shaker (model: YS-LD, manufactured by Yayoi Co., Ltd.). At this time, the angle of shaking is such that the shaking column moves 15 degrees forward and 20 degrees backward, assuming that the vertical (vertical) of the shaker is 0 degree.

The polyethylene sample bottle is fixed to a fixing holder (the sample bottle lid is fixed on the extension of the center of the column) attached to the tip of the column. The prepared sample was measured by the apparatus for measuring the triboelectric charge amount of FIG. 1 in the same manner as the method for measuring the triboelectric charge amount of the toner, and the charge rising rate was calculated by the following equation.
Charge rise rate (%) = 2 friction charge amount for 2 minutes / tribo charge amount for 30 minutes × 100

The evaluation criteria are as follows.
A: Good at 75% or more B: 65% or more, good at less than 75% C: 55% or more, less than 65% no practical problem D: 40% or more, less than 55% practical problem E: 40% Less than bad

(2) Measuring method of OHP transmittance Using a color copier CLC-1000 (manufactured by Canon Inc.), an unfixed image of an A4 half-side solid image was created on an OHP sheet, and iRC3200 (manufactured by Canon Inc.) Fix using a fixing machine. At that time, an image is created by adjusting the development contrast so that the solid portion of the OHP fixed image has an image density satisfying the following expression.
D (on solid paper) −D (on REF paper) = 1.8
(In the above formula, D (on solid paper): OHP was placed on plain paper and the reflection density of the solid image portion was measured. D (on REF paper): OHP was placed on plain paper and the reflection density of the solid white portion was measured. )

For reflection density measurement, X-rite 504 was used, and image density was measured.
The evaluation of OHP transmittance was performed using the above OHP image, and V-570 UV / vis / NIR.
Using a transmitted light measurement mode of Spectrophotometer (manufactured by JASCO Corporation), measurement was performed at a cyan image: 490 nm, a magenta image: 722 nm, and a yellow image: 578 nm.

Evaluation criteria for OHP permeability are as follows.
A: 80% or more, good B: 70% or more, less than 80%, good C: 60% or more, less than 70%, no practical problem D: 50% or more, less than 60%, practical problem E: 50% Less than bad

(3) Fogging measurement In the endurance test, fogging is performed by measuring the average reflectance Dr (%) of plain paper before image printing by using a reflectometer equipped with a color 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 (Fog [%]) was calculated from the following formula.
Fog [%] = Dr [%] − Ds [%]
The color filter used for the measurement was calculated by performing the above measurement using an amber filter for a cyan image, a green filter for a magenta and black image, and a blue filter for a yellow image. The evaluation criteria are as follows.

A: Good at less than 0.7% B: 0.7 or more, good at less than 1.2% C: 1.2 or more, less than 1.5%, no practical problem D: 1.5 or more, 2.0 Less than% is practically problematic E: Poor at 2.0% or more

(4) Measuring method of toner triboelectric charge amount The triboelectric charge amount was measured using the apparatus shown in FIG. About 0.5 to 1.5 g of two-component developer collected from the developing sleeve of the developing device of the copying machine or printer is placed in a metallic measuring container 52 having a screen 53 having a mesh opening of 32 μm at the bottom. The lid 54 is closed. The total weight of the measurement container 52 at this time is weighed and is defined as W ₁ (g). Next, in the suction machine 51 (at least the part in contact with the measurement container 52 is suctioned), the pressure of the vacuum gauge 55 is set to 4 kPa by suctioning from the suction port 57 and adjusting the air volume control valve 56. In this state, suction is performed for 2 minutes to remove the toner by suction. The potential of the electrometer 59 at this time is set to V (volt). Here, 58 is a capacitor, and the capacity is C (mF). Further, the mass of the entire measurement container after the suction is weighed and is defined as W ₂ (g). The triboelectric charge amount (mC / kg) of this sample is calculated by the following equation.

Sample triboelectric charge (mC / kg) = C × V / (W ₁ −W ₂ )
(However, the measurement conditions are 23 ° C. and 50-60% RH)
The evaluation criteria for electrification change in the durability of 10,000 sheets from the start are as follows.
A: Good at less than 2 mC / kg B: Good at 2 mC / kg and less than 4 mC / kg C: No problem in practical use at 4 mC / kg and less than 6 mC / kg D: Practical at 6 mC / kg and less than 8 mC / kg There is a problem E: It is bad at 8mC / kg or more

(5) Color reproducibility Based on the definition of the color system standardized by the International Commission on Illumination (CIE) in 1976, the original image was copied at room temperature and low humidity (23 ° C / 5%) after 10,000 sheets of durability. The color difference (ΔE) from the image was quantitatively evaluated and evaluated based on the following evaluation criteria. Spectrolino the measurement (manufactured by Great Macbeth Co.) (measuring _{conditions: D 50} viewing angle 2 °) was used.
ΔE = {(L ₁ ^* −L ₂ ^* ) ² + (a ₁ ^* −a ₂ ^* ) ² + (b ₁ ^* −b ₂ ^* ) ² } ^1/2
L ₁ ^* : lightness a ₁ ^* , b ₁ ^{* of the} original image: chromaticity indicating hue and saturation of the original image L ₂ ^* : lightness a ₂ ^* , b ₂ ^{* of the} copied image: hue and saturation of the copied image Indicating chromaticity

The evaluation criteria are as follows.
A: ΔE ≦ 3, good B: 3 <ΔE ≦ 5, good C: 5 <ΔE ≦ 8, no practical problem D: 8 <ΔE ≦ 10, practical problem E: 10 <ΔE, bad

<Manufacture of binder resin>
(Example of hybrid resin production)
As a monomer for a vinyl polymer unit, styrene 2.0 mol, 2-ethylhexyl acrylate 0.21 mol, fumaric acid 0.14 mol, α-methylstyrene dimer 0.03 mol, a crosslinking agent and a polymerization initiator Add 0.05 mol of dicumyl peroxide into the dropping funnel. Moreover, as a monomer of the polyester resin unit, 7.0 mol of polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane, 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 dibutyltin oxide (0.2 g) were placed in a glass 4-liter four-necked flask. A thermometer, a stir bar, a condenser and a nitrogen inlet 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 while stirring at a temperature of 145 ° C., the monomer for the vinyl polymer unit, the crosslinking agent and the polymerization from the previous dropping funnel The initiator was added dropwise over 4 hours. Next, the temperature was raised to 200 ° C. and reacted for 4 hours to obtain a hybrid resin. The physical property values are shown in Table 1.

(Example of polyester resin production)
3.6 mol of polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane, 1.6 mol of polyoxyethylene (2.2) -2,2-bis (4-hydroxyphenyl) propane, 1.7 mol of terephthalic acid, 1.4 mol of trimellitic anhydride, 2.4 mol of fumaric acid and 0.12 g of dibutyltin oxide are put into a 4-liter 4-neck flask made of glass, a thermometer, a stirring rod, a condenser and a nitrogen introducing tube. Was installed in a mantle heater. Under a nitrogen atmosphere, reaction was performed at 215 ° C. for 5 hours to obtain a polyester resin. The physical property values are shown in Table 1.

(Example of styrene-acrylic resin production)
・ Styrene 70 parts ・ N-butyl acrylate 24 parts ・ Monobutyl maleate 6 parts ・ Di-t-butyl peroxide 1 part In the container while stirring each of the above components in a four-necked flask containing 200 parts of xylene Was sufficiently replaced with nitrogen, heated to 120 ° C., and then added dropwise over 3.5 hours. Further, the polymerization was completed under reflux of xylene, and then the solvent was distilled off under reduced pressure to obtain a styrene-acrylic resin. The physical property values are shown in Table 1.

<Preparation of colorant master batch>
(Production of water-containing MB1: first melt-kneading step to preparation of water-containing MB)
The first melt-kneading step was performed by the following method to prepare water-containing MB1.
・ Hybrid resin 60 parts ・ Paste yellow pigment 114 parts (P.Y.17; solid content 35 wt%, moisture 65 wt%)

First, the above raw materials are charged into a kneader-type mixer, and the temperature is raised under non-pressurization while mixing. When the maximum temperature is reached (which is inevitably 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 is distributed or transferred to the molten resin phase. after confirming, further heated and melted and kneaded for 15 minutes Tmix ₁ 90 to 100 ° C., to obtain a first kneaded product is sufficiently migrate pigment in the paste. Thereafter, the mixer was once stopped, the hot water was discharged, the water was distilled off by mixing for 5 minutes without heating, the mixture was cooled, and pulverized to about 1 mm by pin mill pulverization to obtain water-containing MB1. The water content of the water-containing MB1 was 13% by mass, and the volume average particle diameter Dm of the pigment particles was 68 nm. Table 2 shows the blending amount of the raw material of the water-containing MB1 and the obtained physical properties.

(Production of hydrous MB2, 3, 5, 11)
The heating time and temperature at the time of preparation of the water-containing MB1 were changed, and it was prepared in the same manner as the water-containing MB1, and water-containing MBs 2, 3, 5, and 11 having the water contents shown in Table 2 were prepared.

(Production of hydrous MB4)
Except for carrying out the first melt-kneading step under pressure (0.15 MPa), it was produced in the same manner as the hydrous MB1, and hydrous MB4 shown in Table 2 was produced.

(Production of hydrous MB6)
As shown in Table 2, 70 parts of a polyester resin as a first binder resin, 50 parts of a pasty yellow pigment (P.Y.17; solid content 60% by mass, moisture 40% by mass) as a pigment, and further 10 parts of water Was used to prepare water-containing MB6 having a water content of 17% by mass and a pigment particle volume average particle size of 81 nm.

(Production of hydrous MB7)
As shown in Table 2, using 60 parts of a hybrid resin as the first binder resin and 160 parts of a paste-like magenta pigment (PR 122; solid content 25% by mass, moisture 75% by mass) as the pigment, Water-containing MB7 having a water content of 16% by mass and a volume average particle size of pigment particles of 64 nm was prepared.

(Production of hydrous MB8)
As shown in Table 2, 60 parts of a hybrid resin was used as the first binder resin, and 80 parts of a pasty cyan pigment (P.B. 15: 3; solid content 50 mass%, moisture 50 mass%) was used as the pigment. Thus, water-containing MB8 having a water content of 12% by mass and a volume average particle diameter of pigment particles of 75 nm was prepared.

(Production of hydrous MB9)
As shown in Table 2, the moisture content was 8 masses using 50 parts of styrene / acrylic resin as the first binder resin, 50 parts of dry powder yellow pigment (P.Y.17) as the pigment, and 10 parts of water. %, And water-containing MB9 having a volume average particle diameter of 110 nm of pigment particles was prepared.

(Preparation of dry colorant master batch 10)
In addition to producing in the same manner as the water-containing MB1, the moisture remaining in the master batch was dried under normal pressure to produce a dry master batch 10 having a water content of 0.7% by mass and a volume average particle size of pigment particles of 132 nm. did.

(Preparation of dry colorant master batch 12)
As shown in Table 2, a masterbatch was prepared using 91 parts of a hybrid resin as a first binder resin and 9 parts of a dry powder yellow pigment (P.Y.17) as a pigment, and then dried under normal pressure. Thus, a dry master batch 12 having a water content of 0.1% by mass and a volume average particle diameter of the pigment particles of 205 nm was produced.

(Production of hydrous MB13)
As shown in Table 2, a hydrous MB was prepared using 39 parts of a hybrid resin as a first binder resin, 61 parts of a dry powder yellow pigment (P.Y.17) as a pigment, and 30 parts of water,
A water-containing MB13 having a water content of 26% by mass and a volume average particle size of 93 nm of pigment particles was produced.

[Example 1]
<Production of toner>
(Second kneading step-preparation of toner)
The second kneading step was performed by the following method to prepare toner 1.
・ Hybrid resin 89.5 parts ・ Purified normal paraffin (melting point 78 ° C.) 4 parts ・ 1,4-di-t-butylsalicylic acid aluminum compound 2 parts ・ Water-containing MB1 20.1 parts And melt-kneading the setting temperature of the twin-screw extrusion kneader at 120 ° C. (kneaded material temperature Tmix ₂ : 126 ° C.) to obtain a second kneaded material, which is cooled to about 1 to 2 mm using a hammer mill. Coarsely pulverized and then finely pulverized to a particle size of 20 μm or less by an air jet type pulverizer. Further, the obtained finely pulverized product was classified using a classifier (elbow jet classifier) to obtain yellow particles 1 (classified product). Table 3 shows the composition and physical properties of the toner.

1.0 part of acicular titanium oxide fine powder (MT-100T: manufactured by Teika Co., Ltd., BET = 62 m ² / g, treated with 10 wt% isobutyltrimethoxysilane) is added to 1,100 parts of the yellow particles. Was added to make toner 1. The volume average particle diameter Dt of the pigment particles in the toner 1 was 81 nm and Dt / Dm = 1.19, and the pigment dispersibility in the toner remained good.

  Further, the weight average diameter of the toner 1 was 7.0 μm. Further, toner 1 and magnetic ferrite carrier particles (average particle diameter 45 μm: Mn—Mg ferrite) surface-coated with a silicone resin were mixed so that the toner concentration would be 7.0% by mass to obtain a two-component developer 1. . For this two-component developer 1, a color copier CLC-1000 (manufactured by Canon Inc.) with a fixing unit from which the oil application mechanism of the fixing unit has been removed is used in a single color mode at room temperature and low humidity (N / L). An evaluation of 10,000 printing durability tests was performed using an original document (23 ° C./5%) and an image area ratio of 5%.

  As a result, as shown in Table 4, the initial OHP transmittance was very good, and a vivid high-quality image was obtained. Further, even after the endurance of 10,000 sheets, there was little change in charging from the initial stage, good color reproducibility, and a yellow image that faithfully reproduced the original with no fog was obtained.

[Example 2]
In the production of toner 1 of Example 1, toner 2 was obtained in substantially the same manner as shown in Table 3, except that 21.5 parts of water-containing MB2 was used. Table 3 shows the composition and physical properties of the toner. When various evaluations were made in the same manner as in Example 1, good results were obtained as shown in Table 4.

[Example 3]
In the production of the toner 1 of Example 1, as shown in Table 3, a toner 3 was obtained in substantially the same manner except that 18.4 parts of water-containing MB3 was used. Table 3 shows the composition and physical properties of the toner. When various evaluations were made in the same manner as in Example 1, good results were obtained as shown in Table 4.

[Example 4]
In the production of toner 1 of Example 1, toner 4 was obtained in substantially the same manner as shown in Table 3, except that 23.0 parts of water-containing MB4 was used. Table 3 shows the composition and physical properties of the toner. When various evaluations were made in the same manner as in Example 1, good results were obtained as shown in Table 4.

[Example 5]
In the production of the toner 1 of Example 1, as shown in Table 3, a toner 5 was obtained in substantially the same manner except that 17.9 parts of water-containing MB5 was used. Table 3 shows the composition and physical properties of the toner. When various evaluations were made in the same manner as in Example 1, good results were obtained as shown in Table 4.

[Example 6]
In the production of the toner 1 of Example 1, as shown in Table 3, 17.9 parts of water-containing MB5 was used, and melt-kneading (kneaded material temperature Tmix ₂ : 142 ° C.) was performed at a preset temperature of the twin-screw extrusion kneader at 130 ° C. A toner 6 was obtained in substantially the same manner except that. Table 3 shows the composition and physical properties of the toner. When various evaluations were made in the same manner as in Example 1, as shown in Table 4, good results were obtained although the OHP transmittance, fog, charge change, and color reproducibility were slightly inferior.

[Example 7]
In the production of the toner 1 of Example 1, as shown in Table 3, 17.9 parts of water-containing MB5 was used, and melt-kneading (kneaded material temperature Tmix ₂ : 151 ° C.) was performed at a set temperature of 140 ° C. of the twin-screw extrusion kneader. A toner 7 was obtained in substantially the same manner except that. Table 3 shows the composition and physical properties of the toner. When various evaluations were made in the same manner as in Example 1, Dt / Dm increased as shown in Table 4, and OH
P transmission, fogging, charge change, and color reproducibility were slightly inferior, but results with no practical problems were obtained.

[Example 8]
In the production of the toner 1 of Example 1, as shown in Table 3, the toner 8 was obtained in substantially the same manner except that 83.7 parts of the hybrid resin and 28.1 parts of the water-containing MB6 were used as the second binder resin. It was. Table 3 shows the composition and physical properties of the toner. When various evaluations were made in the same manner as in Example 1, good results were obtained as shown in Table 4.

[Example 9]
In the production of the toner 1 of Example 1, as shown in Table 3, the toner 9 was obtained in substantially the same manner except that 88.0 parts of the hybrid resin and 23.8 parts of the water-containing MB7 were used as the second binder resin. It was. Table 3 shows the composition and physical properties of the toner. When various evaluations were made in the same manner as in Example 1, as shown in Table 4, good results were obtained although the rise in charge, fogging, and change in charge of the classified product were slightly inferior.

[Example 10]
In the production of the toner 1 of Example 1, as shown in Table 3, it was almost the same except that 92.5 parts of the hybrid resin and 14.2 parts of water-containing MB8 were used as the second binder resin and no release agent was used. In the same manner, Toner 10 was obtained. Table 3 shows the composition and physical properties of the toner. Various evaluations were made in the same manner as in Example 1 using a fixing unit of a color copying machine CLC-1000 (manufactured by Canon Inc.). As a result, good results were obtained as shown in Table 4.

[Example 11]
In the production of the toner 1 of Example 1, as shown in Table 3, except that 93.0 parts of the hybrid resin and 15.2 parts of water-containing MB9 were used as the second binder resin and no release agent was used. In the same manner, Toner 11 was obtained. Table 3 shows the composition and physical properties of the toner. Using a fixing unit of a color copying machine CLC-1000 (manufactured by Canon Inc.), various evaluations were made in the same manner as in Example 1. As shown in Table 4, the charge rising of the classified product, the OHP transmittance, fog, and the change in charge Although the color reproducibility was slightly inferior, a result having no practical problem was obtained.

[Comparative Example 1]
In the production of the toner 1 of Example 1, as shown in Table 3, 89.5 parts of a hybrid resin as a second binder resin, and 17.6 of a dry colorant masterbatch (hereinafter also referred to as “dry MB”) 10 were used. Toner 12 was obtained in substantially the same manner except that part of the toner was used. Table 3 shows the composition and physical properties of the toner. When various evaluations were made in the same manner as in Example 1, as shown in Tables 3 and 4, the second kneaded material temperature Tmix ₂ was high, the pigment particle diameter Dt in the toner was considerably large, and the OHP permeability was high. The fog, durability change, and color reproducibility after durability were poor.

[Comparative Example 2]
In the production of the toner 1 of Example 1, as shown in Table 3, a toner 13 was obtained in substantially the same manner except that 89.5 parts of a hybrid resin and 24.0 parts of water-containing MB11 were used as the second binder resin. It was. Table 3 shows the composition and physical properties of the toner. When various evaluations were made in the same manner as in Example 1, as shown in Tables 3 and 4, large aggregates of the pigment in the toner were generated, and the OHP permeability and the rise of charge were very poor. . In addition, the fog and color reproducibility during the durability study were very bad and the evaluation was stopped.

[Comparative Example 3]
In the production of the toner 1 of Example 1, as shown in Table 3, a toner 14 was obtained in substantially the same manner except that 29.2 parts of a polyester resin and 77.9 parts of dry MB12 were used as the second binder resin. It was. Table 3 shows the composition and physical properties of the toner. When various evaluations were made in the same manner as in Example 1, as shown in Tables 3 and 4, the kneaded material temperature Tmix ₂ was high, and the pigment particle diameter Dt in the toner was considerably large. Met.

[Comparative Example 4]
In the production of the toner 1 of Example 1, as shown in Table 3, the toner 15 was obtained in substantially the same manner except that 95.5 parts of the hybrid resin and 15.5 parts of the water-containing MB 13 were used as the second binder resin. It was. Table 3 shows the composition and physical properties of the toner. When various evaluations were made in the same manner as in Example 1, as shown in Tables 3 and 4, large aggregates of the pigment in the toner were generated, and the OHP permeability and the rise of charge were very poor. . In addition, the fog and color reproducibility during the durability study were very bad and the evaluation was stopped.

It is the schematic of the apparatus for measuring the triboelectric charge amount used in the Example.

Explanation of symbols

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

Claims (13)

A mixture containing at least the first binder resin, the colorant and water is heat-kneaded to obtain a first kneaded product, and the water content is adjusted so that the water content of the first kneaded product is 2 to 25% by mass. A first melt-kneading step to obtain a water-containing colorant masterbatch,
A second melt-kneading step of melt-kneading a toner raw material mixture containing at least a second binder resin and the water-containing colorant master batch to obtain a second kneaded product;
And a pulverizing step of pulverizing the second kneaded product. 2. The water-containing colorant master batch is obtained by adjusting the amount of water so that the water content of the first kneaded product is 3 to 20% by mass in the first melt-kneading step. Toner manufacturing method. The method for producing a toner according to claim 1, wherein the colorant and water in the first melt-kneading step are paste pigments. 3. The toner manufacturing method according to claim 1, wherein in the first melt-kneading step, the colorant is a dry powder pigment. 5. The method for producing a toner according to claim 1, wherein in the first melt-kneading step, the temperature (Tmix ₁ ) of the first kneaded product is 80 to 120 ° C. 6. 6. The toner production method according to claim 1, wherein the colorant in the water-containing colorant master batch has a volume average particle diameter Dm of 5 to 300 nm. The method for producing a toner according to claim 1, wherein the first binder resin has a softening point temperature (Tm ₁ ) of 80 to 120 ° C. 7. The method for producing a toner according to claim 1, wherein the second binder resin has a softening point temperature (Tm ₂ ) of 85 to 135 ° C. The following formula is satisfied with respect to the softening point temperature (Tm ₂ ) of the second binder resin, where Tmix ₂ is the second kneaded material temperature in the second melt-kneading step. The method for producing a toner according to any one of 1 to 8.
Tmix ₂ ≦ Tm ₂ +30 (° C.) The toner production method according to claim 1, wherein a volume average particle diameter Dt of the colorant in the toner is 10 to 500 nm. The following formula is satisfied, where Dm is a volume average particle diameter of the colorant in the water-containing colorant master batch, and Dt is a volume average particle diameter of the colorant in the toner. The method for producing a toner according to any one of the above.
Dt / Dm <2.5 The ratio of said 1st binder resin and a coloring agent is 90: 10-40: 60 in conversion of solid content mass in said 1st melt-kneading process, The any one of Claims 1-11 characterized by the above-mentioned. The toner production method according to one item. In said 1st melt-kneading process, the mass of water is 6-400 mass parts with respect to 100 mass parts of solid content of the said coloring agent, It is any one of Claims 1-12 characterized by the above-mentioned. A method for producing the toner according to the description.

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