JP4966154B2 - Toner manufacturing method, toner, developer, image forming apparatus, and process cartridge - Google Patents

Description

  The present invention relates to a method for producing an image forming toner used as a developer for developing an electrostatic image in electrophotography, electrostatic recording, electrostatic printing, and the like, and the obtained toner. The present invention further relates to an image forming apparatus and a process cartridge that use the toner.

In recent years, as a toner used for image formation in an electrostatic copying process, a reduction in particle size and a spherical shape have been promoted due to an increasing demand for high image quality. The reproducibility of dot-like images and the like is improved by reducing the particle size, and the developability and transferability can be further improved by making the particles spherical.
Conventionally, the toner by the kneading and pulverization method, which has been used as a toner production method, is very difficult to produce such a toner having a small particle size and a spherical shape. The use of polymerized toners by polymerization methods manufactured by a combination method, a dispersion polymerization method, etc. has been expanded.

However, some problems to be solved still remain for the polymerized toner, such as insufficient physical properties of the toner. For example, various toners are used to improve powder flowability and transferability by reducing the particle size and sharpening the particle size distribution, as well as having excellent heat storage stability, low-temperature fixability, and hot offset resistance. Consideration has been made. One of them is a pulverized toner, not a so-called polymerized toner, and a toner production method for forming toner particles by making the weight average molecular weight, particle size, and structure of resin fine particles within an appropriate range, and an invention of a toner, etc. Is disclosed (see Patent Document 1).
In addition, since the toner particles generated by the reaction as described above are greatly affected by the emulsified state, in the case of negatively charged toners, by adjusting the acid value and amine value of the toner to an appropriate range, In addition, a toner production method and a toner invention that can stably obtain the negative chargeability of the toner by improving the balance between the negatively chargeable component and the positively chargeable component are disclosed (patents). Reference 2).

  Patent Document 3 discloses a toner, a manufacturing method thereof, and an invention of an image forming method. This document obtains a toner with a small particle size and a narrow particle size distribution that has a uniform material composition among toner particles, excellent charging stability, little fog and toner scattering, and high image quality. Therefore, the toner material is dissolved or dispersed in an organic solvent to prepare a solution or dispersion of the toner material, and the dissolved or dispersed liquid is dispersed as dispersed particles having a volume average particle size of 0.1 to 3 μm in an aqueous medium. An invention such as a method for producing a toner is described, in which an oil-in-water dispersion is prepared and then the volume average particle size of the dispersed particles is increased to 3 to 9 μm, and then the toner is granulated. (Claims) However, in the aqueous medium phase, the average particle size of the fine particles is 0.1 to 3 μm, which is greatly different from the production method of the present invention.

  Patent Documents 4 to 6 also disclose the invention of the same toner, a method for producing the same, and an image forming method. The toners of these inventions are also granulated by a polymerization method as in Patent Document 3, and Patent Documents 4 and 5 describe that organic fine particles having a volume average particle diameter of 55 nm are used. In Patent Document 6, a toner material is dissolved or dispersed in an organic solvent to prepare a solution or dispersion of the toner material. The dissolved or dispersed liquid is dispersed in an aqueous medium that does not contain organic resin fine particles. Preparing an oil-in-water dispersion by dispersion, adding organic resin fine particles to the oil-in-water dispersion, and granulating toner in the presence of the organic resin fine particles, A method for producing a toner is disclosed, in which the glass transition temperature (Tg) of the fine particles is 80 to 100 ° C., and the weight average molecular weight (Mw) is 5,000 to 20,000.

JP 2005-55498 A JP 2005-265886 A JP 2006-184829 A JP 2006-209094 A JP 2006-243510 A JP 2006-330666 A

  An object of the present invention is to solve the conventional problems described above and achieve the following objects. That is, the present invention improves powder flowability and transferability by reducing the particle size and sharpening the particle size distribution, and is excellent in all of charging characteristics, heat-resistant storage stability, low-temperature fixability, and hot offset resistance. An object is to provide a toner.

The features of the present invention, which is a means for solving the above problems, are listed below.
1. At least, a polymer having a site reactive with a compound having an active hydrogen group, a toner set Narueki having a polyester and a colorant, an aqueous dispersion obtained by dispersing resin fine particles in water of water, organic solvents and surfactants A method for producing toner in which an aqueous medium prepared by mixing with a liquid mixture is brought into contact and granulated by performing at least one of a crosslinking reaction or an elongation reaction,
The volume average particle diameter of the resin particles in the aqueous dispersion rather smaller than larger 60nm than 41 nm, and an acid value of the aqueous dispersion is smaller than a greater than 58mgKOH / g 42mgKOH / g.
2 . In the manufacturing method of the first toner, characterized by having a step of dispersing the toner composition liquid in the aqueous medium
3 . In the method for producing toner of 1 or 2 , the toner composition liquid further contains a release agent, and the release agent is at least one selected from carnauba wax, rice wax, and ester wax. It is characterized by that.
4 . In the method for producing a toner according to any one of 1 to 3, the binder resin of the toner composition liquid includes at least a polymer having a site capable of reacting with a compound having an active hydrogen group, and polyester. The toner composition liquid is subjected to at least one reaction of a crosslinking reaction or an extension reaction in an aqueous medium containing the resin fine particles.
5 . In addition, the present invention is a toner obtained by the method for producing a toner described in any one of 1 to 4 above.
6 . The toner described in 5 above has a volume average particle diameter of 3 to 8 μm and a ratio (Dv / Dn) of the volume average particle diameter (Dv) to the number average particle diameter (Dn) is 1.25 or less. It is characterized by.
7 . The toner described in 5 or 6 is a negatively charged toner.
8 . The toner according to any one of 5 to 7 has an average circularity of 0.94 or more.
9 . The developer of the present invention is a developer for developing an electrostatic latent image, and the developer is a one-component developer using the toner according to any one of 5 to 8. To do.

According to the toner manufacturing method of the present invention, the powder flowability and transferability are improved by reducing the particle size and sharpening the particle size distribution, as well as charging characteristics, heat resistant storage stability, low temperature fixability, and hot offset resistance. In any of these cases, an excellent toner can be provided.
In addition, a process cartridge using the toner obtained by the production method of the present invention as a developer or an image forming apparatus can provide a high-quality image with no abnormal image and excellent fixability. .

  The toner obtained by the production method of the present invention contains at least a binder resin and a colorant and forms particles in an aqueous medium in which resin fine particles are dispersed. In the resulting toner, the toner has a volume The average particle diameter is 3 to 8 μm, and the ratio (Dv / Dn) of the volume average particle diameter (Dv) to the number average particle diameter (Dn) is 1.25 or less. The volume average particle size of the resin fine particles is larger than 41 nm and smaller than 60 nm, preferably 45 to 55 nm, and the acid value of the dispersion of the resin fine particles (the aqueous medium in which the resin fine particles are dispersed). Is greater than 42 mg KOH / g, less than 58 mg KOH / g, preferably 45-55 mg KOH / g.

As will be described in detail in the examples described later, the present inventors have determined the particle size of the resin fine particles and the dispersion of the resin fine particle dispersion (aqueous dispersion in which the resin fine particles are dispersed in water) used for the preparation of the aqueous medium. It was found that a toner having a small particle size and a sharp particle size distribution can be obtained by adjusting the acid value of the toner to an appropriate range. As a result, a toner having excellent developability and transferability can be obtained.

  The effect of the present invention can be obtained if the volume average particle diameter of the resin fine particles is larger than 41 nm and smaller than 60 nm, and the acid value of the dispersion of the resin fine particles is larger than 42 mgKOH / g and smaller than 58 mgKOH / g. However, when it is less than 45 nm and the acid value of the resin fine particle dispersion is less than 45 mg KOH / g, the emulsified oil droplets are likely to be small, and the resulting toner increases in fine powder, resulting in a volume average particle size ( The ratio (Dv / Dn) between Dv) and the number average particle diameter (Dn) deteriorates. Further, when the particle size of the resin fine particles exceeds 55 nm and the acid value of the resin fine particle dispersion exceeds 55 mgKOH / g, the emulsified oil droplets tend to be large, the coarse powder increases, and the volume average particle size (Dv) of the toner increases. ) And the number average particle diameter (Dn) (Dv / Dn) deteriorates.

The binder resin in the organic solvent composition of the present invention (a solution or dispersion obtained by dissolving or dispersing the toner composition in an organic solvent: toner composition liquid) preferably contains a polyester resin. The polyester resin is easier to lower the molecular weight than the styrene acrylic resin, excellent in low-temperature fixability, preferable for energy saving, modified polyester having a functional group containing a nitrogen atom, polyester, colorant, A solution or dispersion in which a toner composition containing at least a nitrogen-containing compound is dissolved or dispersed in an organic solvent is dispersed in an aqueous medium, and at least one of a crosslinking reaction or an extension reaction in the solution or dispersion. It can be produced by carrying out two reactions. In the present specification, “at least one reaction of cross-linking reaction or extension reaction” is referred to as “cross-linking and / or extension reaction”.
Hereinafter, the toner material used in the toner production method of the present invention will be described in detail.

[Organic solvent phase]
<Organic solvent>
The organic solvent is not particularly limited as long as it is a solvent capable of dissolving or dispersing the toner composition to form a toner composition liquid. As a preferable thing, it is preferable that the boiling point of a solvent is less than 150 degreeC from the point that the removal of an organic solvent is easy. For example, toluene, xylene, benzene, carbon tetrachloride, methylene chloride, 1,2-dichloroethane, 1,1,2-trichloroethane, trichloroethylene, chloroform, monochlorobenzene, methyl acetate, ethyl acetate, methyl ethyl ketone, acetone, tetrahydrofuran, etc. alone Or two or more types can be used in combination. Among these, methyl acetate and ethyl acetate are particularly preferable in that they volatilize easily after the toner particles are formed. The amount of the organic solvent used is usually 40 to 300 parts by weight, preferably 60 to 140 parts by weight, and more preferably 80 to 120 parts by weight with respect to 100 parts by weight of the toner solid component.

<Functional group-containing polyester resin>
In the present invention, a polyester prepolymer having an isocyanate group can be used as the modified polyester resin. This prepolymer is included in the “polymer having a site capable of reacting with a compound having an active hydrogen group”. As the polyester prepolymer (A) having such an isocyanate group, a polyester having an active hydrogen group and a polycondensate of polyol (1) and polycarboxylic acid (2) is further reacted with polyisocyanate (3). Examples. Examples of the active hydrogen group possessed by the polyester include hydroxyl groups (alcoholic hydroxyl groups and phenolic hydroxyl groups), amino groups, carboxyl groups, mercapto groups, and the like. Among these, alcoholic hydroxyl groups are preferred.

  Examples of the polyol (1) include a diol (1-1) and a tri- or higher valent polyol (1-2). (1-1) alone or (1-1) and a small amount of (1-2) Mixtures are preferred.

  Diol (1-1) includes alkylene glycol (ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1,6-hexanediol, etc.); alkylene ether glycol (diethylene glycol) , Triethylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene ether glycol, etc.); alicyclic diols (1,4-cyclohexanedimethanol, hydrogenated bisphenol A, etc.); bisphenols (bisphenol A, bisphenol) F, bisphenol S, etc.); alkylene oxide (ethylene oxide, propylene oxide, butylene oxide, etc.) adduct of the above alicyclic diol; Alkylene oxide phenol compound (ethylene oxide, propylene oxide, butylene oxide, etc.), etc. adducts. Among them, preferred are alkylene glycols having 2 to 12 carbon atoms and alkylene oxide adducts of bisphenols, and particularly preferred are alkylene oxide adducts of bisphenols and alkylene glycols having 2 to 12 carbon atoms. It is a combined use.

  The trihydric or higher polyol (1-2) includes 3 to 8 or higher polyhydric aliphatic alcohols (glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, sorbitol, etc.); trihydric or higher phenols (Trisphenol PA, phenol novolak, cresol novolak, etc.); and alkylene oxide adducts of the above trivalent or higher polyphenols.

  Examples of the polycarboxylic acid (2) include dicarboxylic acid (2-1) and trivalent or higher polycarboxylic acid (2-2). (2-1) alone and (2-1) with a small amount of ( The mixture of 2-2) is preferred. Dicarboxylic acid (2-1) includes alkylene dicarboxylic acid (succinic acid, adipic acid, sebacic acid, etc.); alkenylene dicarboxylic acid (maleic acid, fumaric acid, etc.); aromatic dicarboxylic acid (phthalic acid, isophthalic acid, terephthalic acid) And naphthalenedicarboxylic acid). Of these, preferred are alkenylene dicarboxylic acids having 4 to 20 carbon atoms and aromatic dicarboxylic acids having 8 to 20 carbon atoms.

  Examples of the trivalent or higher polycarboxylic acid (2-2) include aromatic polycarboxylic acids having 9 to 20 carbon atoms (trimellitic acid, pyromellitic acid, and the like). In addition, as polycarboxylic acid (2), you may make it react with polyol (1) using the acid anhydride or lower alkyl ester (methyl ester, ethyl ester, isopropyl ester, etc.) of the above-mentioned thing.

  In order to prepare a polyester having an alcoholic hydroxyl group at the terminal by polycondensation reaction, the ratio of the polyol (1) to the polycarboxylic acid (2) is equivalent to the equivalent ratio [OH] / [hydroxyl group [OH] and carboxyl group [COOH]. COOH] is usually 2/1 to 1/1, preferably 1.5 / 1 to 1/1, and more preferably 1.3 / 1 to 1.02 / 1.

  Examples of the polyisocyanate (3) used for preparing the polyester prepolymer by reacting with the alcoholic hydroxyl group of the polyester include aliphatic polyisocyanates (tetramethylene diisocyanate, hexamethylene diisocyanate, 2,6-diisocyanatomethyl carbonate). Proate, etc.); alicyclic polyisocyanates (isophorone diisocyanate, cyclohexylmethane diisocyanate, etc.); aromatic diisocyanates (tolylene diisocyanate, diphenylmethane diisocyanate, etc.); Xylylene diisocyanate); isocyanurates; the polyisocyanate blocked with a phenol derivative, oxime, caprolactam, etc .; and Use of two or more types of these can be cited.

  The use ratio of the polyisocyanate is usually 5/1 to 1/1, preferably 4/1 as the equivalent ratio [NCO] / [OH] of the isocyanate group [NCO] and the hydroxyl group [OH] of the polyester having a hydroxyl group. 1.2 / 1, more preferably 2.5 / 1 to 1.5 / 1. When [NCO] / [OH] exceeds 5, low-temperature fixability deteriorates. When the molar ratio of [NCO] is less than 1, the amount of isocyanate groups contained in the polyester prepolymer (A) is too small, and a crosslinking and / or extension reaction with a compound containing an active hydrogen group described later is performed. I can't.

  The number of isocyanate groups contained per molecule in the polyester prepolymer (A) having an isocyanate group is usually 1 or more, preferably 1.5 to 3 on average, more preferably 1.8 to 2.5 on average. It is. When the number is less than 1 per molecule, the molecular weight of the modified polyester resin after the crosslinking and / or elongation reaction becomes low, and the hot offset resistance of the toner cannot be sufficiently obtained.

<Combination of non-reactive polyester>
In the toner of the present invention, it is important not only to use the polyester prepolymer (A) alone, but also to contain a non-reactive polyester (C) that is not modified as a binder resin component together with this (A). By using (C) in combination, the low-temperature fixability and the glossiness when used in a full-color apparatus are improved.

  Examples of the non-reactive polyester not modified in (C) include polycondensates of polyol (1) and polycarboxylic acid (2) similar to the polyester component in (A). Same as (A). (C) is not limited to unmodified polyester, but may be modified with a chemical bond other than a urea bond, and may be modified with, for example, a urethane bond.

  The polyester prepolymer (A) and the non-modified non-reactive polyester (C) are preferably at least partially compatible with each other in terms of low-temperature fixability and hot offset resistance. Accordingly, a similar composition is preferred for the polyester component (A) and the unmodified non-reactive polyester (C).

  The amount of the polyester prepolymer (A) and the unmodified non-reactive polyester (C) in the case of containing the non-modified non-reactive polyester (C) is usually 5 / It is 95 to 75/25, preferably 10/90 to 25/75, more preferably 12/88 to 25/75, and particularly preferably 12/88 to 22/78. When the weight ratio of the polyester prepolymer (A) is less than 5%, the hot offset resistance of the toner deteriorates, and it is disadvantageous in terms of both heat-resistant storage stability and low-temperature fixability.

  The peak molecular weight measured by gel permeation chromatography (GPC) of the non-reactive polyester (C) is usually 1000 to 30000, preferably 1500 to 10000, more preferably 2000 to 8000. If it is less than 1000, the heat-resistant storage stability of the toner deteriorates, and if it exceeds 30000, the low-temperature fixability deteriorates.

<Active hydrogen group-containing compound>
As will be described later, the above-mentioned polyester prepolymer (A) having an isocyanate group generates a higher molecular weight modified polyester resin by causing at least one reaction of an active hydrogen group-containing compound and a crosslinking reaction or an extension reaction. .
As the active hydrogen group-containing compound, amines can be used. As amines (B), diamine (B1), trivalent or higher polyamine (B2), aminoalcohol (B3), aminomercaptan (B4), amino acid (B5), and amino acids B1-B5 blocked (B6) etc. are mentioned.

Examples of the diamine (B1) include aromatic diamines (phenylenediamine, diethyltoluenediamine, 4,4′-diaminodiphenylmethane, etc.); alicyclic diamines (4,4′-diamino-3,3′-dimethyldicyclohexylmethane, diamines). Cyclohexane, isophoronediamine, etc.); and aliphatic diamines (ethylenediamine, tetramethylenediamine, hexamethylenediamine, etc.) and the like.
Examples of the trivalent or higher polyamine (B2) include diethylenetriamine and triethylenetetramine.
Examples of amino alcohol (B3) include ethanolamine and hydroxyethylaniline.
Examples of amino mercaptan (B4) include aminoethyl mercaptan and aminopropyl mercaptan.
Examples of the amino acid (B5) include aminopropionic acid and aminocaproic acid.
Examples of (B6) obtained by blocking the amino group of (B1) to (B5) include ketimine compounds and oxazoline compounds obtained from the amines of B1 to B5 and ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, etc.) Is mentioned.
Among these amines (B), preferred are B1 and B1 and a small amount of B2 (one or more of (B1), at least one selected from (B1) and at least one selected from a small amount (B2)) It is a mixture of

  The ratio of amines (B) is equivalent to the equivalent ratio [NCO] / [NHx] of isocyanate groups [NCO] in the polyester prepolymer (A) having isocyanate groups and amino groups [NHx] in amines (B). Is usually 1/2 to 2/1, preferably 1.5 / 1 to 1 / 1.5, more preferably 1.2 / 1 to 1 / 1.2. When [NCO] / [NHx] is greater than 2 or less than 1/2, the molecular weight of the urea-modified polyester resin obtained by the crosslinking and / or elongation reaction is lowered, and the hot offset resistance of the toner is deteriorated.

  Furthermore, if necessary, the molecular weight of the modified polyester after completion of the reaction can be adjusted by using a terminator for the crosslinking and / or extension reaction. Examples of the terminator include monoamines (diethylamine, dibutylamine, butylamine, laurylamine, etc.), and those blocked (ketimine compounds).

<Nitrogen-containing compounds>
The nitrogen-containing compound is contained in the toner composition in an organic solvent and serves to bring the acid value of the toner composition liquid into an appropriate range. In the production process of the toner of the present invention, if there is too much acid component in the toner composition due to the presence of the non-reactive polyester (C), the polyester prepolymer (A) and amines (B) are crosslinked and / Or the extension reaction is difficult to proceed. Therefore, by mixing the nitrogen-containing compound, particularly by forming a salt with the non-reactive polyester (C), the influence of the acid component contained in the toner composition is eliminated, and crosslinking and / or elongation reaction is performed. Promote. Further, by adjusting the addition amount of the nitrogen-containing compound, the acid value of the toner composition or the toner composition liquid is set within the above appropriate range, and a toner having a desired particle size and particle size distribution is stably produced.

As the nitrogen-containing compound, a tertiary amine compound can be preferably used. Examples of the tertiary amine compound include amines, amino alcohols, amino mercaptans, and amidines.
Examples of amines include aromatic amines (such as triphenylamine and triallylamine), alicyclic amines (such as N-methylpiperidine); and aliphatic amines (such as triethylamine and trimethylamine).
Examples of amino alcohols include triethanolamine and dihydroxyethylaniline.
Examples of amino mercaptans include triethanethiolamine and trimethanethiolamine.
Examples of amidine include DBU (1,8-diaza-bicyclo [5.4.0] undecene-7) and DBN (1,5-diaza-bicyclo [4.3.0] nonene-5). It is done.
Among these tertiary amine compounds, both the solubility in organic solvents and the salt formation with the non-reactive polyester (C) are favorable, so the compounds represented by the following structural formula (1) are more preferable. .

  The amount of the tertiary amine compound added is preferably 0.05% by weight or more with respect to the weight of the toner composition in order to make the acid value of the toner composition within the proper range. Further, in order to make the amine value of the toner composition within the proper range, it is preferably 3% by weight or less based on the weight of the toner composition.

<Binder resin component>
As described above, the present invention is characterized in that a urea-modified polyester resin obtained by a reaction between a polyester prepolymer (A) and an amine (B) is used as a toner binder resin component, and a non-reactive polyester ( Other components such as C) (including a resin used for producing a colorant master batch) are also used in combination.

  In the present invention, the glass transition point (Tg) of the toner binder resin component is usually 40 to 70 ° C., preferably 45 to 55 ° C. If it is less than 40 ° C., the heat-resistant storage stability of the toner deteriorates, and if it exceeds 70 ° C., the low-temperature fixability becomes insufficient. Due to the coexistence of the urea-modified polyester resin obtained by at least one of the crosslinking reaction or the extension reaction, the toner of the present invention has good heat resistance even when the glass transition point is low as compared with the known polyester resin-based toner. Shows preservability.

  As the storage elastic modulus of the toner, the temperature (TG ′) at which the measurement frequency is 20 Hz becomes 1000 Pa is usually 100 ° C. or higher, preferably 110 to 200 ° C. If it is less than 100 ° C., the resistance to hot offset deteriorates. As the viscosity of the toner, the temperature (Tη) at 100 Pa · s at a measurement frequency of 20 Hz is usually 180 ° C. or lower, preferably 90 to 160 ° C. If it exceeds 180 ° C., the low-temperature fixability deteriorates. That is, TG ′ is preferably higher than Tη from the viewpoint of achieving both low temperature fixability and hot offset resistance. In other words, the difference between TG ′ and Tη (TG′−Tη) is preferably 0 ° C. or more. More preferably, it is 10 degreeC or more, Most preferably, it is 20 degreeC or more. The upper limit of the difference is not particularly limited. Further, from the viewpoint of achieving both heat-resistant storage stability and low-temperature fixability, the difference between Tη and Tg is preferably 0 to 100 ° C. More preferably, it is 10-90 degreeC, Most preferably, it is 20-80 degreeC.

[Aqueous medium phase]
<Aqueous medium>
As the aqueous medium, water alone may be used, but a solvent miscible with water may be used in combination. Examples of miscible solvents include alcohols (methanol, isopropanol, ethylene glycol, etc.), dimethylformamide, tetrahydrofuran, cellosolves, and lower ketones (acetone, methyl ethyl ketone, etc.). These can be used alone or in combination of two or more.

<Resin fine particles>
In the step of granulating toner particles in an aqueous medium, resin fine particles are added for the purpose of controlling the final toner shape (circularity, particle size distribution, etc.). As will be described later, the resin fine particles are considered to be bonded to the surface portion when an organic solvent phase and an active hydrogen group-containing compound (amines) are dispersed in an aqueous medium to form organic dispersed particles. As a result, like the external additive described later, it is considered that the toner base particles obtained are unevenly distributed mainly on the surface portion.

The resin fine particles are prepared in advance by preparing an aqueous dispersion in which resin fine particles are dispersed in water, and mixing this with a mixed liquid of water, an organic solvent and a surfactant to obtain an aqueous medium . Any resin that can form an aqueous dispersion can be used, and it may be a thermoplastic resin or a thermosetting resin. Examples thereof include vinyl resins, polyurethane resins, epoxy resins, polyester resins, polyamide resins, polyimide resins, silicon resins, phenol resins, melamine resins, urea resins, aniline resins, ionomer resins, and polycarbonate resins. As the resin fine particles, two or more of the above resins may be used in combination.

  Of these, vinyl resins, polyurethane resins, epoxy resins, polyester resins, and combinations thereof are preferred because an aqueous dispersion of fine spherical resin particles is easily obtained. Vinyl resins are polymers obtained by homopolymerization or copolymerization of vinyl monomers, such as styrene- (meth) acrylic acid ester resins, styrene-butadiene copolymers, (meth) acrylic acid-acrylic acid ester copolymers. Styrene-acrylonitrile copolymer, styrene-maleic anhydride copolymer, styrene- (meth) acrylic acid copolymer, and the like.

In the toner of the present invention, the amount of resin fine particles contained in the obtained toner particles after the external additive treatment is set in the range of 0.5 to 5.0 wt%.
When the content is less than 0.5 wt%, the heat-resistant storage stability of the toner is deteriorated, and blocking occurs during storage and in the developing machine. On the other hand, if the content exceeds 5.0 wt%, the resin fine particles inhibit the exudation of the wax as a release agent contained in the toner in the toner fixing step, so that the release effect cannot be obtained, and hot offset Occurs.
The content of the resin fine particles can be measured by analyzing a substance caused by the resin fine particles, not by the toner particles, using a pyrolysis gas chromatograph mass spectrometer, and calculating from the peak area. The detector is preferably a mass spectrometer, but is not particularly limited.

The dispersion / blending amount of the resin fine particles in the aqueous medium may be set so as to satisfy the above-described conditions relating to the content, but is usually within a range of about 0.5 to 10 wt%.
The glass transition point (Tg) of the resin fine particles is preferably 40 to 100 ° C., and the weight average molecular weight is preferably 9000 to 200,000. When the Tg of the resin fine particles is less than 40 ° C. and / or the weight average molecular weight is less than 9000, the heat-resistant storage stability of the toner deteriorates, and blocking occurs during storage and in the developing machine. Further, if the Tg of the resin fine particles exceeds 80 ° C. and / or the weight average molecular weight exceeds 200,000, the resin fine particles inhibit the adhesion of the toner to the fixing paper in the toner fixing step, and the fixing minimum temperature is decreased. An increase is seen.
Furthermore, when the particle diameter of the resin fine particles is in the range of 45 to 55 nm, the particle diameter of the emulsified oil droplets can be stabilized, and the particle size distribution of the finally obtained toner can be narrowed.

[Other ingredients]
<Colorant>
Known dyes and pigments can be used as the colorant. For example, carbon black, nigrosine dye, iron black, naphthol yellow S, Hansa yellow (10G, 5G, G), cadmium yellow, yellow iron oxide, ocher , Yellow lead, titanium yellow, polyazo yellow, oil yellow, Hansa yellow (GR, A, RN, R), pigment yellow L, benzidine yellow (G, GR), permanent yellow (NCG), Vulcan fast yellow (5G, R), Tartrazine Lake, Quinoline Yellow Lake, Anthrazan Yellow BGL, Isoindolinone Yellow, Bengala, Red Dan, Lead Zhu, Cadmium Red, Cadmium Mercury Red, Antimon Zhu, Permanent Red 4R, Para Red, Phi Sayred, Parachlor Ortonito Aniline Red, Resol Fast Scarlet G, Brilliant Fast Scarlet, Brilliant Carmine B, Permanent Red (F2R, F4R, FRL, FRLL, F4RH), Fast Scarlet VD, Belkan Fast Rubin B, Brilliant Scarlet G, Resol Rubin GX, Permanent Red F5R , Brilliant Carmine 6B, Pigment Scarlet 3B, Bordeaux 5B, Tolujing Maroon, Permanent Bordeaux F2K, Helio Bordeaux BL, Bordeaux 10B, Bon Maroon Light, Bon Maroon Medium, Eosin Lake, Rhodamine Lake B, Rhodamine Lake Y, Alizarin Lake, Thioindigo red B, thioindigo maroon, oil red, quinacridone red, pyrazolone red Polyazo Red, Chrome Vermillion, Benzidine Orange, Perinone Orange, Oil Orange, Cobalt Blue, Cerulean Blue, Alkaline Blue Lake, Peacock Blue Lake, Victoria Blue Lake, Metal Free Phthalocyanine Blue, Phthalocyanine Blue, Fast Sky Blue, Indanthrene Blue (RS, BC), indigo, ultramarine blue, bitumen, anthraquinone blue, fast violet B, methyl violet lake, cobalt purple, manganese purple, dioxane violet, anthraquinone violet, chrome green, zinc green, chromium oxide, pyridian, emerald green, pigment Green B, Naphthol Green B, Green Gold, Acid Green Lake, Malachite Green Lake, Lid Russian nin green, anthraquinone green, titanium oxide, zinc white, litbon and mixtures thereof can be used. The content of the colorant is usually 1 to 15 wt%, preferably 3 to 10 wt% in the toner base.
The colorant can also be used as a master batch combined with a resin.

  As binder resin kneaded with manufacture of a masterbatch or a masterbatch, for example, in addition to the above urea-modified polyester resin (A) and non-reactive polyester resin (C), polystyrene, poly p-chlorostyrene, polyvinyltoluene, etc. Styrene and substituted polymers thereof: styrene-p-chlorostyrene copolymer, styrene-propylene copolymer, styrene-vinyltoluene copolymer, styrene-vinylnaphthalene copolymer, styrene-methyl acrylate copolymer Styrene-ethyl acrylate copolymer, styrene-butyl acrylate copolymer, styrene-octyl acrylate copolymer, styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, styrene-methacrylic acid Butyl copolymer, styrene-α Chloromethyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-acrylonitrile-indene copolymer, styrene-malein Styrenic copolymers such as acid copolymers and styrene-maleic ester copolymers; polymethyl methacrylate, polybutyl methacrylate, polyvinyl chloride, polyvinyl acetate, polyethylene, polypropylene, polyester, epoxy resins, epoxy polyol resins, Polyurethane, polyamide, polyvinyl butyral, polyacrylic acid resin, rosin, modified rosin, terpene resin, aliphatic or alicyclic hydrocarbon resin, aromatic petroleum resin, chlorinated paraffin, paraffin wax, etc. These can be used alone or in admixture.

The master batch can be obtained by mixing and kneading the binder resin for the master batch and the colorant under a high shear force. At this time, an organic solvent can be used to enhance the interaction between the colorant and the binder resin. In addition, the so-called flushing method, which is a method of mixing and kneading an aqueous paste containing water of a colorant together with a resin and an organic solvent, transferring the colorant to the resin side, and removing moisture and organic solvent components, Since the wet cake can be used as it is, it does not need to be dried and is preferably used. For mixing and kneading, a high shearing dispersion device such as a three-roll mill is preferably used.
The colorant or masterbatch can be dissolved or dispersed in the organic solvent phase, but is not limited thereto.

<Release agent>
Further, a wax may be contained as a release agent together with the toner binder resin component and the colorant. Known waxes can be used, such as polyolefin wax (polyethylene wax, polypropylene wax, etc.); long chain hydrocarbon (paraffin wax, sasol wax, etc.); carbonyl group-containing wax. Of these, carbonyl group-containing waxes are preferred.
Carbonyl group-containing waxes include polyalkanoic acid esters (carnauba wax, montan wax, trimethylolpropane tribehenate, pentaerythritol tetrabehenate, pentaerythritol diacetate dibehenate, glycerin tribehenate, 1,18. -Octadecanediol distearate, etc.); polyalkanol esters (tristearyl trimellitic acid, distearyl maleate, etc.); polyalkanoic acid amides (ethylene diamine dibehenyl amide, etc.); polyalkylamides (trimellitic acid tristearyl amide, etc.) And dialkyl ketones (such as distearyl ketone). Among these carbonyl group-containing waxes, polyalkanoic acid esters are preferred.
The melting point of the wax is usually 40 to 160 ° C, preferably 50 to 120 ° C, more preferably 60 to 90 ° C. A wax having a melting point of less than 40 ° C. has an adverse effect on heat resistant storage stability, and a wax having a melting point of more than 160 ° C. tends to cause a cold offset when fixing at a low temperature.

Further, the melt viscosity of the wax is preferably 5 to 1000 cps, more preferably 10 to 100 cps as a measured value at a temperature 20 ° C. higher than the melting point. Waxes exceeding 1000 cps have poor effects for improving hot offset resistance and low-temperature fixability.
The amount of the wax used is usually 0 to 40% by weight, preferably 3 to 30% by weight as the content in the toner base. The wax can be dissolved or dispersed in the organic solvent phase, but is not limited thereto.

<Charge control agent>
The toner of the present invention may contain a charge control agent as necessary. All known charge control agents can be used, such as nigrosine dyes, triphenylmethane dyes, chromium-containing metal complex dyes, molybdate chelate pigments, rhodamine dyes, alkoxy amines, quaternary ammonium salts (fluorine-modified). Quaternary ammonium salts), alkylamides, phosphorus simple substances or compounds, tungsten simple substances or compounds, fluorine-based activators, salicylic acid metal salts, and metal salts of salicylic acid derivatives. Specifically, Nitronine-based dye Bontron 03, quaternary ammonium salt Bontron P-51, metal-containing azo dye Bontron S-34, oxynaphthoic acid metal complex E-82, salicylic acid metal complex E- 84, E-89 of a phenol-based condensate (manufactured by Orient Chemical Industry Co., Ltd.), TP-302 of a quaternary ammonium salt molybdenum complex, TP-415 (manufactured by Hodogaya Chemical Industry Co., Ltd.), quaternary ammonium Copy charge PSYVP2038 of salt, copy blue PR of triphenylmethane derivative, copy charge of quaternary ammonium salt NEG VP2036, copy charge NX VP434 (manufactured by Hoechst), LRA-901, LR-147 which is a boron complex ( Nippon Carlit), copper phthalocyanine, perylene, quinacridone, Examples thereof include azo pigments and other polymer compounds having a functional group such as a sulfonic acid group, a carboxyl group, and a quaternary ammonium salt.

  The amount of charge control agent used is determined by the type of binder resin, the presence or absence of additives used as necessary, and the toner production method including the dispersion method, and is not limited to a specific one. Preferably, it is used in the range of 0.1 to 10 parts by weight with respect to 100 parts by weight of the binder resin. The range of 0.2 to 5 parts by weight is preferable. When the amount exceeds 10 parts by weight, the chargeability of the toner is too high, the effect of the main charge control agent is reduced, the electrostatic attractive force with the developing roller is increased, the flowability of the developer is reduced, and the image density is reduced. Incurs a decline. These charge control agents can be dissolved and dispersed after being melt-kneaded with a masterbatch and resin, and of course, they may be added directly when dissolved and dispersed in an organic solvent. It is preferable to make it.

[Preparation of toner particles]
The toner of the present invention can be produced by the following method, but is not limited thereto.

<Toner production method in aqueous medium>
In the aqueous medium in which the resin fine particles are dispersed as described above, the organic solvent phase is dispersed as shown below to form toner particles.

<Dispersion and reaction of organic solvent phase>
As described above, the toner particles are prepared by dispersing the organic solvent phase containing the polyester prepolymer (A) in the aqueous medium phase together with the amines (B) and the tertiary amine compound, and performing an extension reaction or the reaction in the aqueous medium. It is formed through a process of causing at least one reaction of a crosslinking reaction to form a urea-modified polyester.
As a method for stably forming a dispersion comprising a polyester prepolymer (A) in an aqueous medium phase, a composition of a toner raw material comprising a polyester prepolymer (A) dissolved or dispersed in an organic solvent in an aqueous medium phase (Hereinafter referred to as “toner raw material”) and a method of dispersing by shearing force. A polyester prepolymer (A) dissolved or dispersed in an organic solvent and other toner composition colorant, colorant masterbatch, release agent, charge control agent, non-reactive polyester resin (C), etc. It may be mixed when the dispersion is formed in the aqueous medium phase, but it is better to mix the toner raw material in advance and then dissolve or disperse it in an organic solvent, and then add the mixture to the aqueous medium phase and disperse it. preferable. In the present invention, other toner raw materials such as a colorant, a release agent, and a charge control agent do not necessarily have to be mixed when forming particles in the aqueous medium phase, but after the particles are formed. , May be added. For example, after forming particles containing no colorant, the colorant can be added by a known dyeing method.
The dispersion method is not particularly limited, and known equipment such as a low-speed shear method, a high-speed shear method, a friction method, a high-pressure jet method, and an ultrasonic wave can be applied. In order to make the particle size of the dispersion 2 to 20 μm, a high-speed shearing type is preferable. When a high-speed shearing disperser is used, the rotational speed is not particularly limited, but is usually 1000 to 30000 rpm, preferably 5000 to 20000 rpm. The dispersion time is not particularly limited, but in the case of a batch method, it is usually 0.1 to 5 minutes. The temperature during dispersion is usually 0 to 150 ° C. (under pressure), preferably 40 to 98 ° C. Higher temperatures are preferred in that the dispersion of the polyester prepolymer (A) has a low viscosity and is easy to disperse.

The usage-amount of the aqueous medium with respect to 100 parts of solid components contained in the organic solvent phase of a polyester prepolymer (A) is 50-2000 weight part normally, Preferably it is 100-1000 weight part. If the amount is less than 50 parts by weight, the dispersion state of the toner composition is poor, and toner particles having a predetermined particle diameter cannot be obtained. If it exceeds 20000 parts by weight, it is not economical. Moreover, a dispersing agent can also be used as needed. It is preferable to use a dispersant because the particle size distribution becomes sharp and the dispersion is stable.
As a dispersant for emulsifying and dispersing the organic solvent phase containing the polyester prepolymer (A), an anionic surfactant such as alkylbenzene sulfonate, α-olefin sulfonate, phosphate ester, alkylamine salt, Amine salt types such as amino alcohol fatty acid derivatives, polyamine fatty acid derivatives, imidazoline, and quaternary ammonium such as alkyltrimethylammonium salt, dialkyldimethylammonium salt, alkyldimethylbenzylammonium salt, pyridinium salt, alkylisoquinolinium salt, benzethonium chloride Nonionic surfactants such as salt-type cationic surfactants, fatty acid amide derivatives, polyhydric alcohol derivatives, such as alanine, dodecyldi (aminoethyl) glycine, di (octylaminoethyl) glycine and N-al Le -N, amphoteric surfactants such as N- dimethyl ammonium betaine.

  Further, by using a surfactant having a fluoroalkyl group, the effect can be obtained in a very small amount. Examples of the anionic surfactant having a fluoroalkyl group preferably used include fluoroalkylcarboxylic acids having 2 to 10 carbon atoms and metal salts thereof, disodium perfluorooctanesulfonyl glutamate, 3- [omega-fluoroalkyl (6 carbon atoms). -11 omega-fluoroalkyl) oxy] -1-alkyl (C3-C4 alkyl) sodium sulfonate, 3- [omega-fluoroalkanoyl (C6-C8 omega-fluoroalkanoyl) -N-ethyl Amino] -1-propanesulfonate sodium, fluoroalkyl (fluoroalkyl having 11 to 20 carbon atoms) carboxylic acid and metal salt, perfluoroalkylcarboxylic acid (perfluoroalkylcarboxylic acid having 7 to 13 carbon atoms) and metal salt thereof , Perfluoroalkyl (carbon 4 to 12 perfluoroalkyl) sulfonic acid and its metal salt, perfluorooctanesulfonic acid diethanolamide, N-propyl-N- (2-hydroxyethyl) perfluorooctanesulfonamide, perfluoroalkyl (6 to 10 carbon atoms) Perfluoroalkyl) sulfonamidopropyltrimethylammonium salt, perfluoroalkyl (C6-C10 perfluoroalkyl) -N-ethylsulfonylglycine salt, monoperfluoroalkyl (C6-C16 monoperfluoroalkyl) Examples thereof include ethyl phosphate.

  Product names include Surflon S-111, S-112, S-113 (Asahi Glass Co., Ltd.), Florard FC-93, FC-95, FC-98, FC-129 (Sumitomo 3M Co., Ltd.), Unidyne DS-101. DS-102 (Daikin Kogyo Co., Ltd.), Mega-Fac F-l0, F-l20, F-113, F-191, F-812, F-833 (Dainippon Ink Co., Ltd.), Xtop EF-102 , 103, 104, 105, 112, 123A, 123B, 306A, 501, 201, 204 (manufactured by Tochem Products), and Fagento F-100, F150 (manufactured by Neos).

  In addition, as cationic surfactants, aliphatic primary, secondary or tertiary amino acids (or amino acids) having a fluoroalkyl group, perfluoroalkyl (perfluoroalkyl having 6 to 10 carbon atoms) sulfonamidopropyltrimethylammonium salt Aliphatic quaternary ammonium salts such as benzalkonium salt, benzethonium chloride, pyridinium salt, imidazolinium salt, trade names such as Surflon S-121 (Asahi Glass Co., Ltd.), Florard FC-135 (Sumitomo 3M Co., Ltd.), Unidyne DS-202 (manufactured by Daikin Industries, Ltd.), MegaFuck F-150, F-824 (manufactured by Dainippon Ink, Inc.), Xtop EF-132 (manufactured by Tochem Products), and Footgent F-300 (manufactured by Neos) ) And the like.

Moreover, tricalcium phosphate, calcium carbonate, titanium oxide, colloidal silica, hydroxyapatite, etc. can be used as an inorganic compound dispersant which is hardly soluble in water.
Further, the dispersed droplets may be stabilized by a polymer protective colloid. For example, acrylic acid, methacrylic acid, α-cyanoacrylic acid, α-cyanomethacrylic acid, itaconic acid, crotonic acid, fumaric acid, maleic acid or maleic anhydride and other (meth) acrylic monomers containing hydroxyl groups Such as β-hydroxyethyl acrylate, β-hydroxyethyl methacrylate, β-hydroxypropyl acrylate, β-hydroxypropyl methacrylate, γ-hydroxypropyl acrylate, γ-hydroxypropyl methacrylate, 3-chloroacrylate 2-hydroxypropyl, 3-chloro-2-hydroxypropyl methacrylate, diethylene glycol monoacrylate, diethylene glycol monomethacrylate, glycerol monoacrylate, glycerol monomethacrylate, N-methylol acrylamide, N-methylol methacrylamide, etc., vinyl alcohol or ethers with vinyl alcohol, such as vinyl methyl ether, vinyl ethyl ether, vinyl propyl ether, or esters of compounds containing vinyl alcohol and a carboxyl group, For example, vinyl acetate, vinyl propionate, vinyl butyrate, acrylamide, methacrylamide, diacetone acrylamide or their methylol compounds, acid chlorides such as acrylic acid chloride, methacrylic acid chloride, vinyl pyridine, vinyl pyrrolidone, vinyl imidazole, ethyleneimine Homopolymers or copolymers such as those having a nitrogen atom, or a heterocyclic ring thereof, polyoxyethylene, polyoxypropylene, Reoxyethylene alkylamine, polyoxypropylene alkylamine, polyoxyethylene alkylamide, polyoxypropylene alkylamide, polyoxyethylene nonylphenyl ether, polyoxyethylene lauryl phenyl ether, polyoxyethylene stearyl phenyl ester, polyoxyethylene nonylphenyl Polyoxyethylenes such as esters, celluloses such as methyl cellulose, hydroxyethyl cellulose, and hydroxypropyl cellulose can be used.
In addition, when an acid such as calcium phosphate salt or an alkali-soluble material is used as the dispersion stabilizer, the calcium phosphate salt is dissolved from the toner particles by a method such as washing with water after dissolving the calcium phosphate salt with an acid such as hydrochloric acid. Remove. It can also be removed by operations such as enzymatic degradation.

  When a dispersant is used, the dispersant can remain on the surface of the toner particles. However, it is preferable from the charged surface of the toner that the dispersant is washed and removed after the crosslinking and / or elongation reaction.

  The crosslinking and / or elongation reaction time is selected depending on the reactivity of the isocyanate group structure of the polyester prepolymer (A) and the amines (B), but is usually 10 minutes to 40 hours, preferably 2 to 24 hours. It is. The reaction temperature is usually 0 to 150 ° C., preferably 40 to 98 ° C. Moreover, a well-known catalyst can be used as needed. Specific examples include dibutyltin laurate and dioctyltin laurate.

  In order to remove the organic solvent from the obtained emulsified dispersion, a method in which the temperature of the entire system is gradually raised to completely evaporate and remove the organic solvent in the droplets can be employed. Alternatively, it is possible to spray the emulsified dispersion in a dry atmosphere to completely remove the water-insoluble organic solvent in the droplets to form toner fine particles, and to evaporate and remove the aqueous dispersant together. . As a dry atmosphere in which the emulsified dispersion is sprayed, a gas obtained by heating air, nitrogen, carbon dioxide gas, combustion gas, or the like, in particular, various air currents heated to a temperature equal to or higher than the boiling point of the highest boiling solvent used is generally used. A spray dryer, belt dryer, rotary kiln, etc. can be used, and the desired quality can be obtained in a short time.

In addition, the obtained toner particles can be classified as necessary to adjust the particle size distribution. In the classification operation, the fine particle portion can be removed in the liquid by a cyclone, a decanter, centrifugation, or the like. Of course, the classification operation may be performed after obtaining the powder after drying, but it is preferably performed in a liquid in terms of efficiency. The unnecessary fine particles or coarse particles obtained can be returned to the kneading step and used for the formation of particles. At that time, fine particles or coarse particles may be wet.
It is preferable to remove the used dispersant from the obtained emulsified dispersion as much as possible, but it is preferable to carry out it simultaneously with the above classification operation.

Mixing or giving mechanical impact force to the powder mixture after drying with different types of particles such as release agent fine particles, charge control fine particles, fluidizing agent fine particles, and colorant fine particles By immobilizing and fusing on the surface, it is possible to prevent detachment of foreign particles from the surface of the resulting composite particle.
Specific means include a method of applying an impact force to the mixture by blades rotating at high speed, a method of injecting and accelerating the mixture in a high-speed air stream, and causing particles or composite particles to collide with an appropriate collision plate, etc. is there. As equipment, Ong mill (manufactured by Hosokawa Micron Co., Ltd.), I-type mill (manufactured by Nippon Pneumatic Co., Ltd.) has been modified to lower the pulverization air pressure, hybridization system (manufactured by Nara Machinery Co., Ltd.), kryptron System (manufactured by Kawasaki Heavy Industries, Ltd.), automatic mortar, etc.

[Application of external additives]
As the external additive for assisting the fluidity, developability and chargeability of the toner, inorganic fine particles can be preferably used. The primary particle diameter of the inorganic fine particles is preferably 5 mμ to 2 μm, and particularly preferably 5 mμ to 500 mμ. Moreover, it is preferable that the specific surface area by BET method is 20-500 m < ² > / g. The proportion of the inorganic fine particles used is preferably 0.01 to 5% by weight of the toner, and particularly preferably 0.01 to 2.0% by weight.

Specific examples of the inorganic fine particles include, for example, silica, alumina, titanium oxide, barium titanate, magnesium titanate, calcium titanate, strontium titanate, zinc oxide, tin oxide, silica sand, clay, mica, wollastonite, diatomaceous earth. Examples include soil, chromium oxide, cerium oxide, pengala, antimony trioxide, magnesium oxide, zirconium oxide, barium sulfate, barium carbonate, calcium carbonate, silicon carbide, and silicon nitride.
In addition, polymer fine particles such as polystyrene obtained by soap-free emulsion polymerization, suspension polymerization and dispersion polymerization, methacrylic acid ester and acrylic acid ester copolymer, polycondensation system such as silicone, benzoguanamine and nylon, thermosetting resin And polymer particles.

  Such a fluidizing agent can be surface-treated to increase hydrophobicity and prevent deterioration of flow characteristics and charging characteristics even under high humidity. For example, silane coupling agents, silylating agents, silane coupling agents having an alkyl fluoride group, organic titanate coupling agents, aluminum coupling agents, silicone oils, modified silicone oils and the like are preferable surface treatment agents. .

(Particle size of resin fine particles)
The particle size of the resin fine particles was measured using a laser diffraction / scattering particle size distribution measuring apparatus. For example, a measurement method using a laser diffraction / scattering particle size distribution measuring apparatus LA-920 manufactured by Horiba Ltd. will be described.
The measurement uses a flow cell, puts a dispersion medium in the sample bath, removes bubbles after circulation, and adjusts the optical axis. Increase the circulation speed, put the resin fine particle dispersion into the sample bath so that the transmittance is in the range of 85 to 90%, perform ultrasonic treatment for 5 minutes, then adjust the optical axis once more, data Measurement is carried out at 10-15 times. As the particle diameter of the resin fine particles, a median diameter which is a particle diameter corresponding to a cumulative 50% was used.

(Acid value, amine value)
The acid value of the resin fine particle dispersion and the toner can be measured according to the standard of JISK 0070, and the amine value of the toner can be measured according to the standard of ASTM D 2074.

(Average circularity)
It is important for the toner of the present invention to have a specific shape and shape distribution, and with an irregularly shaped toner having an average circularity of less than 0.90 and far away from a sphere, satisfactory transferability and dust No high quality images can be obtained. As a method for measuring the shape, an optical detection band method is suitable in which a suspension containing particles is passed through an imaging unit detection band on a flat plate, and a particle image is optically detected and analyzed by a CCD camera. .
A toner having an average circularity of 0.90 to 0.98, preferably 0.975 to 0.900, which is a value obtained by dividing the perimeter of an equivalent circle having the same projected area obtained by this method by the perimeter of the actual particle. It has been found that the method is effective for forming a high-definition image having a reproducibility with an appropriate density. More preferably, particles having an average circularity of 0.970 to 0.950 and a circularity of less than 0.94 are 15% or less. Further, when the average circularity is 0.975 or more, in a system that employs blade cleaning or the like, a cleaning failure occurs on the photosensitive member or the transfer belt, causing stain on the image. For example, development / transfer with a low image area ratio results in a small amount of residual toner and poor cleaning does not become a problem. The image-formed toner may be generated as a transfer residual toner on the photosensitive member, and if accumulated, the image may be soiled. In addition, the charging roller that contacts and charges the photosensitive member is contaminated, and the original charging ability cannot be exhibited.

(Volume average particle diameter and Dv / Dn value)
The toner for image formation of the present invention has a volume average particle diameter (Dv) of 3.0 to 8.0 μm, and a ratio (Dv / Dn) of the volume average particle diameter (Dv) to the number average particle diameter (Dn). Is preferably 1.25 or less. By using a toner having such a particle size and particle size distribution, it is excellent in heat-resistant storage stability, low-temperature fixability, and hot offset resistance, and particularly when used in a full-color copying machine, etc. Sex is obtained. On the other hand, when the Dv / Dn value exceeds 1.25, the distribution from the small particle size to the large particle size becomes wide. As a result, the charge amount distribution is widened, so that developability and transferability become non-uniform, Image graininess and sharpness deteriorate.

In general, it is said that the smaller the particle size of the toner, the more advantageous it is to obtain a high-resolution and high-quality image, but it is disadvantageous for transferability and cleaning properties. is there. In addition, when the volume average particle size is smaller than the range of the present invention, in the case of a two-component developer, the toner is fused to the surface of the magnetic carrier during a long period of stirring in the developing device, and the charging ability of the magnetic carrier is reduced. When used as a developer, toner filming on the developing roller and toner fusion to a member such as a blade for thinning the toner are likely to occur.
On the contrary, when the volume average particle diameter of the toner is larger than the range of the present invention, it becomes difficult to obtain a high-resolution and high-quality image, and when the balance of the toner in the developer is performed. In many cases, the variation in toner particle size becomes large.
On the other hand, if Dv / Dn exceeds 1.25, the charge amount distribution becomes wide and the resolving power decreases, which is not preferable.

(Two-component developer)
The toner of the present invention can be mixed with a magnetic carrier and used as a two-component developer. In this case, the carrier to toner content ratio in the developer is preferably 1 to 10 parts by weight of toner with respect to 100 parts by weight of carrier.
As the magnetic carrier, conventionally known ones such as iron powder, ferrite powder, magnetite powder, magnetic resin carrier having a particle diameter of about 20 to 200 μm can be used. Examples of the coating material include amino resins such as urea-formaldehyde resin, melamine resin, benzoguanamine resin, urea resin, polyamide resin, and epoxy resin. Polyvinyl and polyvinylidene resins such as acrylic resins, polymethyl methacrylate resins, polyacrylonitrile resins, polyvinyl acetate resins, polyvinyl alcohol resins, polyvinyl butyral resins, polystyrene resins and styrene acrylic copolymer resins, Halogenated olefin resins such as vinyl, polyester resins such as polyethylene terephthalate resin and polybutylene terephthalate resin, polycarbonate resins, polyethylene resins, polyvinyl fluoride resins, polyvinylidene fluoride resins, polytrifluoroethylene resins, polyhexafluoro Propylene resin, copolymer of vinylidene fluoride and acrylic monomer, copolymer of vinylidene fluoride and vinyl fluoride, tetrafluoroethylene and vinylidene fluoride and non- Monomers including a fluoro terpolymers such, and silicone resins. Moreover, you may contain electrically conductive powder etc. in coating resin as needed. As the conductive powder, metal powder, carbon black, titanium oxide, tin oxide, zinc oxide or the like can be used. These conductive powders preferably have an average particle diameter of 1 μm or less. When the average particle diameter is larger than 1 μm, it becomes difficult to control electric resistance.

(Single component developer)
The toner of the present invention can also be used as a one-component magnetic developer that does not use a carrier or a non-magnetic developer.
In addition, when preparing the developer, in order to improve the fluidity, storage stability, developability, and transferability of the developer, the hydrophobic silica fine particles listed above are further listed in the developer produced as described above. Inorganic fine particles such as powder may be added and mixed. For mixing external additives, a general powder mixer is used, but it is preferable to equip a jacket or the like to adjust the internal temperature. In order to change the load history applied to the external additive, the external additive may be added in the middle or gradually.
Of course, you may change the rotation speed of a mixer, rolling speed, time, temperature, etc. A strong load may be given first, then a relatively weak load, and vice versa.
Examples of the mixing equipment that can be used include a V-type mixer, a rocking mixer, a Ladige mixer, a Nauter mixer, a Henschel mixer, and the like.

An image forming apparatus using the image forming toner of the present invention as a developer will be described.
FIG. 1 is a schematic configuration diagram illustrating an example of an image forming apparatus according to the present invention. In the figure, reference numeral 100 is a copying apparatus main body, 200 is a paper feed table on which the copying apparatus is placed, 300 is a scanner mounted on the copying apparatus main body 100, and 400 is an automatic document feeder (ADF) mounted thereon.
The copying apparatus main body 100 has a tandem type in which four image forming units 18 each having various units for performing an electrophotographic process such as charging, developing, and cleaning are arranged in parallel around a photosensitive member 40 as a latent image carrier. An image forming apparatus 20 is provided. Above the tandem image forming apparatus 20, there is provided an exposure apparatus 21 that exposes the photoreceptor 40 with laser light based on image information to form a latent image. Further, an intermediate transfer belt 10 made of an endless belt member is provided at a position facing each photoconductor 40 of the tandem type image forming apparatus 20. A primary transfer unit 62 for transferring the toner images of the respective colors formed on the photoconductor 40 to the intermediate transfer belt 10 is disposed at a position facing the photoconductor 40 via the intermediate transfer belt 10.

A secondary transfer device 22 that collectively transfers the toner images superimposed on the intermediate transfer belt 10 onto transfer paper conveyed from the paper feed table 200 is disposed below the intermediate transfer belt 10. The secondary transfer device 22 is configured by spanning a secondary transfer belt 24 that is an endless belt between two rollers 23, and is disposed by pressing against the support roller 16 via the intermediate transfer belt 10. The toner image on 10 is transferred onto a transfer sheet. A fixing device 25 for fixing the image on the transfer paper is provided beside the secondary transfer device 22. The fixing device 25 is configured by pressing a pressure roller 27 against a fixing belt 26 that is an endless belt.
The secondary transfer device 22 described above also has a sheet transport function for transporting the transfer paper after image transfer to the fixing device 25. Of course, a transfer roller or a non-contact charger may be arranged as the secondary transfer device 22, and in such a case, it is difficult to provide this sheet conveyance function together.
In the illustrated example, a reversing device 28 for reversing the transfer paper so as to record images on both sides of the transfer paper is provided below the secondary transfer device 22 and the fixing device 25 in parallel with the tandem image forming device 20 described above. .
The developing device 4 of the image forming unit 18 uses a developer containing the above toner. In the developing device 4, the developer carrying member carries and conveys the developer, and an alternating electric field is applied at a position facing the photoconductor 40 to develop the latent image on the photoconductor 40. By applying the alternating electric field, the developer is activated, the charge amount distribution of the toner can be narrowed, and the developability can be improved.
Further, the developing device 4 can be a process cartridge that is integrally supported together with the photoreceptor 40 and is detachably formed on the main body of the image forming apparatus. In addition, the process cartridge may include a charging unit and a cleaning unit.

The operation of the image forming apparatus is as follows.
First, a document is set on the document table 30 of the automatic document feeder 400, or the automatic document feeder 400 is opened and a document is set on the contact glass 32 of the scanner 300, and the automatic document feeder 400 is closed. Hold it down.
When a start switch (not shown) is pressed, when the document is set on the automatic document feeder 400, the document is transported and moved onto the contact glass 32, and then the document is set on the other contact glass 32. At that time, the scanner 300 is immediately driven to travel the first traveling body 33 and the second traveling body 34. Then, the first traveling body 33 emits light from the light source and further reflects the reflected light from the document surface toward the second traveling body 34 and reflects by the mirror of the second traveling body 34 and passes through the imaging lens 35. The document is placed in the reading sensor 36 and the original content is read.
When a start switch (not shown) is pressed, one of the support rollers 14, 15 and 16 is rotationally driven by a drive motor (not shown), the other two support rollers are driven to rotate, and the intermediate transfer belt 10 is rotated and conveyed. To do. At the same time, the individual image forming means 18 rotates the photoconductor 40 to form black, yellow, magenta, and cyan monochrome images on each photoconductor 40. Then, along with the conveyance of the intermediate transfer belt 10, the monochrome images are sequentially transferred to form a composite color image on the intermediate transfer belt 10.
On the other hand, when a start switch (not shown) is pressed, one of the paper feed rollers 42 of the paper feed table 200 is selectively rotated, and the sheet is fed out from one of the paper feed cassettes 44 provided in multiple stages in the paper bank 43, so Then, the sheets are separated one by one into the paper feed path 46, transported by the transport roller 47, guided to the paper feed path 48 in the copying machine main body 100, and abutted against the registration roller 49 and stopped.
Alternatively, the sheet feed roller 50 is rotated to feed out the sheets on the manual feed tray 51, separated one by one by the separation roller 52, put into the manual feed path 53, and abutted against the registration roller 49 and stopped.
Then, the registration roller 49 is rotated in synchronization with the composite color image on the intermediate transfer belt 10, the sheet is fed between the intermediate transfer belt 10 and the secondary transfer device 22, and is transferred by the secondary transfer device 22. A color image is recorded on the sheet.

The image-transferred sheet is conveyed by the secondary transfer device 22 and sent to the fixing device 25. The fixing device 25 applies heat and pressure to fix the transferred image, and then the switching roller 55 is used to switch the discharge image. The paper is discharged at 56 and stacked on the paper discharge tray 57. Alternatively, it is switched by the switching claw 55 and put into the sheet reversing device 28, where it is reversed and guided again to the transfer position, and an image is recorded also on the back surface, and then discharged onto the discharge tray 57 by the discharge roller 56.
On the other hand, the intermediate transfer belt 10 after the image transfer is removed by the intermediate transfer belt cleaning device 17 to remove residual toner remaining on the intermediate transfer belt 10 after the image transfer, so that the tandem image forming apparatus 20 can prepare for the image formation again.

  EXAMPLES The present invention will be further described below with reference to examples, but the present invention is not limited to these examples. Hereinafter, unless otherwise specified, “part” means part by weight, and “%” means percent by weight (wt%).

<Example 1>
Hereinafter, the production of the toner of the present invention will be described step by step.
-Synthesis of resin particles-
In a reaction vessel equipped with a stir bar and a thermometer, 683 parts of water, 11 parts of sodium salt of ethylene oxide methacrylate adduct sulfate (Eleminol RS-30, manufactured by Sanyo Chemical Industries), 80 parts of styrene, 83 parts of methacrylic acid, When 110 parts of butyl acrylate, 12 parts of butyl thioglycolate and 1 part of ammonium persulfate were added and stirred for 15 minutes at 500 rpm, a white emulsion was obtained. The system was heated to raise the system temperature to 75 ° C. and reacted for 5 hours. Further, 30 parts of a 1% ammonium persulfate aqueous solution was added, and the mixture was aged at 75 ° C. for 4 hours, and an aqueous vinyl resin (a copolymer of styrene-methacrylic acid-butyl acrylate-methacrylic acid ethylene oxide adduct sulfate sodium salt). A dispersion was obtained. This is designated as [resin fine particle dispersion 1].
When this [resin fine particle dispersion 1] was measured with a laser diffraction / scattering particle size distribution analyzer (LA-920, manufactured by Horiba, Ltd.), the volume average particle size was 46 nm and was determined by the method described above. The acid value was 45 mgKOH / g.
A portion of [resin fine particle dispersion 1] was dried to isolate the resin component. The glass transition temperature (Tg) of this resin was 42 ° C., and the weight average molecular weight was 30,000.

~ Preparation of aqueous phase ~
990 parts of water, 65 parts of [resin fine particle dispersion 1], 37 parts of 48.5% aqueous solution of sodium dodecyl diphenyl ether disulfonate (Eleminol MON-7: manufactured by Sanyo Chemical Industries), and 90 parts of ethyl acetate were mixed and stirred. A liquid was obtained. This is designated [Aqueous Phase 1].

~ Synthesis of low molecular weight polyester ~
In a reaction vessel equipped with a condenser, a stirrer and a nitrogen inlet tube, 229 parts of bisphenol A ethylene oxide 2-mole adduct, 529 parts of bisphenol A propylene oxide 3-mole adduct, 208 parts terephthalic acid, 46 parts adipic acid and dibutyl Add 2 parts of tin oxide, react for 8 hours at 230 ° C. under normal pressure, and further react for 5 hours under reduced pressure of 10-15 mmHg, then add 44 parts of trimellitic anhydride to the reaction vessel, 180 ° C. under normal pressure for 2 hours. The reaction yielded [low molecular weight polyester 1]. [Low molecular weight polyester 1] had a number average molecular weight of 2500, a weight average molecular weight of 6700, a Tg of 43 ° C., and an acid value of 25 mgKOH / g.

~ Synthesis of intermediate polyester ~
In a reaction vessel equipped with a cooling pipe, a stirrer and a nitrogen introduction pipe, 682 parts of bisphenol A ethylene oxide 2-mole adduct, 81 parts of bisphenol A propylene oxide 2-mole adduct, 283 parts of terephthalic acid, trimellitic anhydride 22 And 2 parts of dibutyltin oxide were added, reacted at 230 ° C. under normal pressure for 8 hours, and further reacted under reduced pressure of 10 to 15 mmHg for 5 hours to obtain [Intermediate Polyester 1]. [Intermediate Polyester 1] had a number average molecular weight of 2,100, a weight average molecular weight of 9,500, a Tg of 55 ° C., an acid value of 0.5 mgKOH / g, and a hydroxyl value of 51 mgKOH / g.

~ Synthesis of a modified polyester resin (prepolymer 1) capable of reacting with a compound having at least an active hydrogen group ~
In a reaction vessel equipped with a cooling tube, a stirrer and a nitrogen introduction tube, 410 parts of the above [intermediate polyester 1], 89 parts of isophorone diisocyanate, and 500 parts of ethyl acetate were added and reacted at 100 ° C. for 5 hours. ] Was obtained. [Prepolymer 1] had a free isocyanate of 1.53%.

~ Synthesis of ketimine ~
In a reaction vessel equipped with a stirrer and a thermometer, 170 parts of isophoronediamine and 75 parts of methyl ethyl ketone were charged and reacted at 50 ° C. for 5 hours to obtain [ketimine compound 1]. The amine value of [ketimine compound 1] was 418 mgKOH / g.

~ Preparation of oil phase ~
In a container in which a stir bar and a thermometer are set, 400 parts of the above [low molecular weight polyester 1], 110 parts of carnauba wax and 947 parts of ethyl acetate are charged, heated to 80 ° C. with stirring, and kept at 80 ° C. for 5 hours. After holding, it was cooled to 30 ° C. at 1 hour. Next, 160 parts of carbon black (Regal 400R, manufactured by Cabot) and 500 parts of ethyl acetate were charged in a container and mixed for 1 hour to obtain [Raw material solution 1].
[Raw material solution 1] 1324 parts are transferred to a container, and using a bead mill (Ultra Visco Mill, manufactured by Imex Co., Ltd.), a liquid feeding speed is 1 kg / hr, a disk peripheral speed is 6 m / sec, and 0.5 mm zirconia beads are 80% by volume. The wax was dispersed under conditions of 3 passes. Next, 1324 parts of a 65% ethyl acetate solution of [low molecular weight polyester 1] was added, and one pass was performed with a bead mill under the above conditions to obtain [Pigment / Wax Dispersion 1]. The solid content concentration of [Pigment / Wax Dispersion 1] (130 ° C., 30 minutes) was 50%.

~ Emulsification ~
[Pigment / Wax Dispersion 1] 648 parts, [Prepolymer 1] 154 parts, [Ketimine Compound 1] 8.5 parts, tertiary amine compound (U-CAT 660M) represented by the structural formula (1) above 0.9 part) (San Apro Co., Ltd.) is placed in a container and mixed with a TK homomixer (made by Tokushu Kika Co., Ltd.) at 5,000 rpm for 1 minute, and then 1200 parts of [Aqueous Phase 1] is added to the container. [Emulsification slurry 1] was obtained by mixing with a mixer at a rotational speed of 10,000 rpm for 20 minutes.
That is, the aqueous medium containing the resin fine particles and the toner composition liquid are brought into contact with each other and dispersed, and an elongation reaction is performed. In this case, the contact between the aqueous medium and the toner composition liquid may be performed by adding the aqueous medium to the toner composition liquid, or the toner composition liquid may be added to the aqueous medium. Regardless of the order of contact between the aqueous medium and the toner composition liquid, either the aqueous medium or the toner composition liquid can be added by adding the other while stirring. In the case of this contact, it can be carried out by a commonly used mixer. For example, as described above, after the first stirring step, it may have a two-step process of emulsifying by applying high shear. it can. The toner composition liquid includes at least a polymer having a site capable of reacting with a compound having an active hydrogen group, a polyester and a colorant, and may further contain a wax as described above. In this case, the above-mentioned organic solvent can be used as the toner liquid.

~ Solvent removal ~
[Emulsion slurry 1] was put into a container equipped with a stirrer and a thermometer, and after removing the solvent at 30 ° C. for 8 hours, aging was carried out at 45 ° C. for 4 hours to obtain [Dispersion slurry 1].

~Washing~
After filtering 100 parts of the [dispersed slurry 1] under reduced pressure, the following treatments (1) to (4) were performed to obtain [filter cake 1].
(1): 100 parts of ion-exchanged water was added to the filter cake, mixed with a TK homomixer (10 minutes at 12,000 rpm), and then filtered.
(2): 1O parts of 10% sodium hydroxide aqueous solution was added to the filter cake of (1), mixed with a TK homomixer (30 minutes at 12,000 rpm), and then filtered under reduced pressure.
(3): 100 parts of 10% hydrochloric acid was added to the filter cake of (2), mixed with a TK homomixer (rotation speed: 12,000 rpm for 10 minutes), and then filtered.
(4): 300 parts of ion-exchanged water was added to the filter cake of (3), mixed with a TK homomixer (rotation speed: 12,000 rpm for 10 minutes), and then filtered twice to obtain a cake. . This is designated as [Filter cake 1].

~ Drying process ~
[Filter cake 1] was dried at 45 ° C. for 48 hours using a circulating dryer.
Thereafter, the mixture was sieved with a mesh having an opening of 75 μm to obtain toner base particles. this,
[Toner base particle 1].

~ External additive treatment ~
To 100 parts of the above [toner base particle 1], 0.7 part of hydrophobic silica and 0.3 part of hydrophobized titanium oxide were added as external additives and mixed using a Henschel mixer to obtain a toner. This is referred to as [Toner 1]. Table 1 shows each physical property value of [Toner 1].

-Adjustment of developer-
[Toner 1] 5% and [Developer 1], a two-component developer composed of 95% copper-zinc ferrite carrier coated with a silicone resin and having an average particle diameter of 40 μm, were prepared. Using this [Developer 1], using Ricoh's imgio Neo 450 modified machine capable of printing 45 sheets of A4 size paper per minute, continuous printing was performed and evaluated by the following evaluation method. It shows in Table 2.

<Example 2>
The “resin fine particle dispersion 2” was prepared by carrying out “~ synthesis of resin fine particles” in Example 1 as described in the following “Synthesis of resin fine particles (2)”. Was used in the same manner as in Example 1 to obtain [Toner 2].
~ Synthesis of resin fine particles (2) ~
In a reaction vessel equipped with a stir bar and a thermometer, 683 parts of water, 11 parts of sodium salt of ethylene oxide methacrylate adduct sulfate (Eleminol RS-30, manufactured by Sanyo Chemical Industries), 80 parts of styrene, 83 parts of methacrylic acid, When 110 parts of butyl acrylate, 12 parts of butyl thioglycolate and 1 part of ammonium persulfate were added and stirred for 15 minutes at 500 rpm, a white emulsion was obtained. The system was heated to raise the system temperature to 75 ° C. and reacted for 5 hours.
Further, 30 parts of a 1% ammonium persulfate aqueous solution was added, and the mixture was aged at 75 ° C. for 6 hours, and then an aqueous vinyl resin (a copolymer of styrene-methacrylic acid-butyl acrylate-methacrylic acid ethylene oxide adduct sulfate sodium salt). A dispersion was obtained. This is designated as [resin fine particle dispersion 2]. The volume average particle diameter of this [resin fine particle dispersion 2] measured with a laser diffraction particle size distribution analyzer (LA-920, manufactured by Horiba, Ltd.) was 53 nm, and the acid value was 54 mgKOH / g.
A portion of [resin fine particle dispersion 2] was dried to isolate the resin component. The Tg of the resin was 42 ° C., and the weight average molecular weight was 30,500.

<Comparative Example 1>
The “Resin fine particle dispersion 3” was prepared by performing “Synthesis of resin fine particles” in Example 1 as described in the following “Synthesis of resin fine particles (ratio 1)”. [Toner 3] was obtained in the same manner as in Example 1.
-Synthesis of resin fine particles (ratio 1)-
In a reaction vessel equipped with a stir bar and a thermometer, 683 parts of water, 11 parts of sodium salt of ethylene oxide methacrylate adduct sulfate (Eleminol RS-30, manufactured by Sanyo Chemical Industries), 80 parts of styrene, 83 parts of methacrylic acid, When 110 parts of butyl acrylate, 12 parts of butyl thioglycolate and 1 part of ammonium persulfate were charged and stirred at 600 rpm for 15 minutes, a white emulsion was obtained. The system was heated to raise the system temperature to 75 ° C. and reacted for 4 hours.
Further, 30 parts of a 1% ammonium persulfate aqueous solution was added, and the mixture was aged at 75 ° C. for 4 hours, and an aqueous vinyl resin (a copolymer of styrene-methacrylic acid-butyl acrylate-methacrylic acid ethylene oxide adduct sulfate sodium salt). A dispersion was obtained. This is designated as [resin fine particle dispersion 3]. The volume average particle size of the [resin fine particle dispersion 3] measured by a laser diffraction particle size distribution analyzer (LA-920, manufactured by Horiba, Ltd.) was 42 nm, and the acid value was 38 mgKOH / g. A portion of [resin fine particle dispersion 3] was dried to isolate the resin component. The Tg of the resin was 41 ° C. and the weight average molecular weight was 28,500.
[Toner 3] was obtained in the same manner as in Example 1 except that [Resin fine particle dispersion 3] was used.

<Comparative example 2>
“Resin fine particle dispersion 4” was prepared by performing “Synthesis of resin fine particles” in Example 1 as described in “Synthesis of resin fine particles (ratio 2)” below. [Toner 4] was obtained in the same manner as in Example 1.
-Synthesis of resin fine particles (ratio 2)-
In a reaction vessel in which a stir bar and a thermometer were set, 683 parts of water, 11 parts of sodium salt of ethylene oxide methacrylate adduct sulfate (Eleminol RS-30, manufactured by Sanyo Chemical Industries), 80 parts of styrene, 83 parts of methacrylic acid, When 110 parts of butyl acrylate, 12 parts of butyl thioglycolate and 1 part of ammonium persulfate were added and stirred for 15 minutes at 400 rpm, a white emulsion was obtained. The system was heated to raise the system temperature to 75 ° C. and reacted for 5 hours.
Further, 30 parts of a 1% ammonium persulfate aqueous solution was added, and the mixture was aged at 75 ° C. for 4 hours, and an aqueous vinyl resin (a copolymer of styrene-methacrylic acid-butyl acrylate-methacrylic acid ethylene oxide adduct sulfate sodium salt). A dispersion was obtained. This is designated as [resin fine particle dispersion 4]. The volume average particle diameter of this [resin fine particle dispersion 4] measured by a laser diffraction particle size distribution analyzer (LA-920, manufactured by Horiba Seisakusho) was 58 nm, and the acid value was 60 mgKOH / g.
A portion of [resin fine particle dispersion 4] was dried to isolate the resin component. The resin content had a Tg of 42 ° C. and a weight average molecular weight of 31,000.
[Toner 4] was obtained in the same manner as in Example 1 except that this [resin fine particle dispersion 4] was used.

<Comparative Example 3>
In the resin fine particle synthesizing step of Example 1, 683 parts of water and sodium salt of ethylene oxide methacrylate adduct sulfate (Eleminol RS-30, manufactured by Sanyo Chemical Industries) were placed in a reaction vessel equipped with a stirring bar and a thermometer. 11 parts, 80 parts of styrene, 133 parts of methacrylic acid, 60 parts of butyl acrylate, 12 parts of butyl thioglycolate and 1 part of ammonium persulfate were charged and stirred at 600 rpm for 15 minutes. An emulsion was obtained. The system temperature was raised to 75 ° C. by heating to react for 4 hours. Further, 30 parts of a 1% ammonium persulfate aqueous solution was added, and the mixture was aged at 75 ° C. for 4 hours to form a vinyl resin (a copolymer of styrene-methacrylic acid-butyl acrylate-methacrylic acid ethylene oxide adduct sulfate sodium salt). An aqueous dispersion was obtained. This is designated as [resin fine particle dispersion 5]. The obtained [resin fine particle dispersion 5] was measured by a laser diffraction particle size distribution analyzer (LA-920, manufactured by Horiba Seisakusho), the volume average particle diameter was 42 nm, and the acid value was 60 mgKOH / g. .
A portion of [resin fine particle dispersion 5] was dried to isolate the resin component. The Tg of the resin was 39 ° C., and the weight average molecular weight was 25,300. [Toner 5] was obtained in the same manner as in Example 1 except that this [resin fine particle dispersion 5] was used.

<Comparative example 4>
In the resin fine particle synthesizing step of Example 1, 683 parts of water and sodium salt of ethylene oxide methacrylate adduct sulfate (Eleminol RS-30, manufactured by Sanyo Chemical Industries) were placed in a reaction vessel equipped with a stirring bar and a thermometer. 11 parts, 80 parts of styrene, 53 parts of methacrylic acid, 140 parts of butyl acrylate, 12 parts of butyl thioglycolate and 1 part of ammonium persulfate were charged and stirred for 15 minutes at 400 rpm. An emulsion was obtained. The system temperature was raised to 75 ° C. and the reaction was allowed to proceed for 5 hours. Further, 30 parts of a 1% ammonium persulfate aqueous solution was added, and the mixture was aged at 75 ° C. for 4 hours to give a vinyl resin (a copolymer of styrene-methacrylic acid-butyl acrylate-methacrylic acid ethylene oxide adduct sulfate sodium salt). An aqueous dispersion was obtained. This is designated as [resin fine particle dispersion 6]. The volume average particle diameter of this [resin fine particle dispersion 6] measured by a laser diffraction particle size distribution analyzer (LA-920, manufactured by Horiba, Ltd.) was 59 nm, and the acid value was 41 mgKOH / g.
A portion of [resin fine particle dispersion 6] was dried to isolate the resin component. The resin content had a Tg of 41 ° C. and a weight average molecular weight of 29,400. [Toner 6] was obtained in the same manner as in Example 1 except that this [resin fine particle dispersion 6] was used.

<Comparative Example 5>
In the resin fine particle synthesizing step of Example 1, 683 parts of water and sodium salt of ethylene oxide methacrylate adduct sulfate (Eleminol RS-30, manufactured by Sanyo Chemical Industries) were placed in a reaction vessel equipped with a stirring bar and a thermometer. 11 parts, 80 parts of styrene, 108 parts of methacrylic acid, 85 parts of butyl acrylate, 12 parts of butyl thioglycolate and 1 part of ammonium persulfate were charged and stirred at 600 rpm for 15 minutes. An emulsion was obtained. The system temperature was raised to 75 ° C. and the reaction was allowed to proceed for 4 hours. Further, 30 parts of a 1% ammonium persulfate aqueous solution was added, and the mixture was aged at 75 ° C. for 4 hours to give a vinyl resin (a copolymer of styrene-methacrylic acid-butyl acrylate-methacrylic acid ethylene oxide adduct sulfate sodium salt). An aqueous dispersion was obtained. This is designated as [resin fine particle dispersion 7]. The volume average particle diameter of this [resin fine particle dispersion 7] measured by a laser diffraction particle size distribution analyzer (LA-920, manufactured by Horiba, Ltd.) was 41 nm, and the acid value was 52 mgKOH / g. A portion of [resin fine particle dispersion 7] was dried to isolate the resin component. The resin content had a Tg of 40 ° C. and a weight average molecular weight of 27,100. [Toner 7] was obtained in the same manner as in Example 1 except that [Resin fine particle dispersion 7] was used.

<Comparative Example 6>
In the resin fine particle synthesizing step of Example 1, 683 parts of water and sodium salt of ethylene oxide methacrylate adduct sulfate (Eleminol RS-30, manufactured by Sanyo Chemical Industries) were placed in a reaction vessel equipped with a stirring bar and a thermometer. 11 parts, 80 parts of styrene, 73 parts of methacrylic acid, 120 parts of butyl acrylate, 12 parts of butyl thioglycolate and 1 part of ammonium persulfate were charged and stirred at 500 rpm for 15 minutes. An emulsion was obtained. The system temperature was raised to 75 ° C. and the reaction was allowed to proceed for 5 hours. Further, 30 parts of a 1% ammonium persulfate aqueous solution was added, and the mixture was aged at 75 ° C. for 5 hours to obtain an aqueous vinyl resin (a copolymer of sodium salt of styrene-methacrylic acid-butyl acrylate-methacrylic acid ethylene oxide adduct sulfate). A dispersion was obtained. This is designated as [resin fine particle dispersion 8]. The obtained [resin fine particle dispersion 8] was measured with a laser diffraction / scattering particle size distribution analyzer (LA-920, manufactured by HORIBA, Ltd.), the volume average particle diameter was 49 nm, and the acid value was 38 mgKOH / g. It was. A portion of [resin fine particle dispersion 8] was dried to isolate the resin component. The Tg of this resin was 41 ° C. and the weight average molecular weight was 28,300. [Toner 8] was obtained in the same manner as in Example 1 except that [Resin fine particle dispersion 8] was used.

[Evaluation methods]
(Evaluation item)
(1) Measurement of volume average particle diameter and (Dv / Dn) Volume average particle diameter (Dv) and number average particle diameter (Dn) can be measured by a Coulter counter method. Examples of the measuring device for the particle size distribution of toner particles by the Coulter counter method include Coulter Counter TA-II and Coulter Multisizer II (both manufactured by Coulter). The measurement method is described below.
First, 0.1 to 5 ml of a surfactant (preferably alkyl benzene sulfonate) is added as a dispersant to 100 to 150 ml of the electrolytic aqueous solution. Here, the electrolytic solution is a solution prepared by preparing a 1% NaCl aqueous solution using primary sodium chloride. For example, ISOTON-II (manufactured by Coulter) can be used. Here, 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. Volume distribution and number distribution are calculated.
From the obtained distribution, the volume average particle diameter (Dv) and the number average particle diameter of the toner can be obtained.
As channels, 2.00 to less than 2.52 μm; 2.52 to less than 3.17 μm; 3.17 to less than 4.00 μm; 4.00 to less than 5.04 μm; 5.04 to less than 6.35 μm; 6 Less than 35 to 8.00 μm; less than 8.00 to less than 10.08 μm; less than 10.08 to less than 12.70 μm; less than 12.70 to less than 16.00 μm; less than 16.00 to less than 20.20 μm; Uses 13 channels of less than 40 μm; 25.40 to less than 32.00 μm; 32.00 to less than 40.30 μm, and targets particles having a particle size of 2.00 μm to less than 40.30 μm. Further, (Dv / Dn) was automatically calculated from the above value.

(2) Average circularity The circularity can be measured by using a flow particle image analyzer (Flow Particle Image Analyzer). A measurement method using a flow particle image analyzer (Flow Particle Image Analyzer) will be described below.
The measurement of toner, toner particles and external additives using a flow particle image analyzer can be performed using, for example, a flow particle image analyzer FPIA-2000 manufactured by Toa Medical Electronics Co., Ltd.
The measurement is performed by removing fine dust through a filter, and as a result, in 10 ^-3 cm ³ of water having a measurement range (for example, an equivalent circle diameter of 0.60 μm or more and less than 159.21 μm) in 10 ml of water having 20 or less particles. Add a few drops of a nonionic surfactant (preferably Contaminone N manufactured by Wako Pure Chemical Industries, Ltd.), add 5 mg of the measurement sample, and use a UH-50 manufactured by STM Ultrasonic Disperser under the conditions of 20 kHz and 50 W / 10 cm ³ . Dispersion treatment is performed for 1 minute, and further, dispersion treatment is performed for a total of 5 minutes, and a sample dispersion liquid in which the particle concentration of the measurement sample is 4000 to 8000 pieces / 10 ⁻³ cm ³ (targeting particles in the equivalent circle diameter range). The particle size distribution of particles having an equivalent circle diameter of 0.60 μm or more and less than 159.21 μm is measured.

The sample dispersion liquid is passed through a flow path (expanded along the flow direction) of a flat and flat transparent flow cell (thickness: about 200 μm). In order to form an optical path that passes across the thickness of the flow cell, the strobe and the CCD camera are mounted on the flow cell so as to be opposite to each other. While the sample dispersion is flowing, strobe light is irradiated at 1/30 second intervals to obtain an image of the particles flowing through the flow cell, so that each particle has a certain range parallel to the flow cell. Photographed as a two-dimensional image. From the area of the two-dimensional image of each particle, the diameter of a circle having the same area is calculated as the equivalent circle diameter.
In about 1 minute, the equivalent circle diameter of 1200 or more particles can be measured, and the number based on the equivalent circle diameter distribution and the ratio (number%) of particles having a prescribed equivalent circle diameter can be measured. As shown in Table 1, the results (frequency% and cumulative%) can be obtained by dividing the range of 0.06 to 400 μm into 226 channels (divided into 30 channels for one octave). In actual measurement, particles are measured in the range where the equivalent circle diameter is 0.60 μm or more and less than 159.21 μm.

(3) Charge amount 6 g of developer was weighed and charged in a metal cylinder that could be sealed, and the charge amount was measured by the blow-off method.

(4) Cleanability Using RICOH's imagio MP C4500 remodeled machine as an evaluation machine, the transfer residual toner on the photoconductor that passed the cleaning process after outputting 100 sheets is blank with Scotch tape (Sumitomo 3M Co., Ltd.). Measured with a Macbeth reflection densitometer RD514 type, ◎ if the difference from the blank is less than 0.005, ◯ 0.005-0.010, 0.011-0.02 Was evaluated as Δ and Δ exceeding 0.02.

(5) Image density The imagio MP C4500 remodeled machine manufactured by Ricoh was used as an evaluation machine, and after running 150,000 image charts of 50% image area in single color mode, the solid image was printed on 6000 paper manufactured by Ricoh. After image output, the image density was measured by X-Rite (manufactured by X-Rite). This was performed for four colors alone, and the average was obtained. If this value is less than 1.2, x, if it is 1.2 or more and less than 1.4, △, if it is 1.4 or more and less than 1.8, ○, if it is 1.8 or more and less than 2.2 ◎.

(6) Image graininess and sharpness Using a modified imagio MP C4500 machine manufactured by Ricoh as an evaluation machine, a photographic image was output in a single color, and the degree of graininess and sharpness was visually evaluated. From the good ones, the evaluation was made in four stages: ◎, ○, Δ, ×. ◎ is equivalent to offset printing, ◯ is slightly worse than offset printing, Δ is much worse than offset printing, and × is about the conventional electrophotographic image, which is very bad.

(7) Stain on the background Using a modified imagio MP C4500 machine manufactured by Ricoh as an evaluation machine, after running 30,000 image charts with a 50% image area in monochrome mode, the blank image is stopped during development and developed. The developer on the subsequent photoconductor was transferred to a tape, and the difference from the image density of the untransferred tape was measured with a 938 spectrocytometer (manufactured by X-Rite). The smaller the difference in image density, the better the background stains, and the higher the rank in the order of x, Δ, ○, ◎.

(8) White spots inside character images Ricoh's imagio MP C4500 remodeled machine is used as an evaluator, and after running 30,000 image charts with 50% image area in monochromatic mode, the character image is converted to Ricoh. Four colors were overlaid on an OHP sheet of type DX and output, and the toner non-transfer frequency at which the inside of the line image of the character portion was lost was compared with a step sample. Rank 1 is the lowest and rank 5 is the highest. In case of rank 1 or 2, it was rated as “X”, in case of rank 3, “△”, in case of rank 4, “ラ ン ク”, in case of rank 5.

(9) Toner fluidity A powder tester (PT-N type, manufactured by Hosokawa Micron) is loaded with meshes of 75 μm, 45 μm, and 22 μm openings in order from the top, and 2 g of the toner base is put on the uppermost 75 μm mesh. Then, a vibration of 1 mm in the vertical direction was applied for 10 seconds, and the fluidity (cohesion degree) of the toner base was calculated from the residual amount of toner on each mesh.
Aggregation degree (%) = (5 × (remaining toner amount (g) on 75 μm mesh))
+ 3 × (residual toner amount on 45 μm mesh (g))
+ (Residual toner amount on 22 μm mesh (g))) × 10
When the degree of aggregation was 8% or less, ◎, when it was 8 to 16%, ◯, when it was 16 to 25%, Δ, and when it was 25% or more, ×.

(10) Fixing Using a modified imagio MP C4500 machine manufactured by Ricoh as an evaluation machine, a solid image and a thick paper transfer paper (Ricoh, type 6200 and NBS Ricoh copy printing paper <135>) with a solid image of 0 Fixing evaluation was performed with a toner adhesion amount of 85 ± 0.1 mg / cm 2. A fixing test was performed by changing the temperature of the fixing belt, and an upper limit temperature at which hot offset did not occur on plain paper was defined as an upper limit fixing temperature. Further, the minimum fixing temperature was measured with a thick paper. The lower limit fixing temperature was determined as the fixing lower limit temperature at the fixing roll temperature at which the residual ratio of the image density after rubbing the obtained fixed image with a pad was 70% or more. The upper limit fixing temperature was ◎ for 190 ° C or higher, ○ for 190-180 ° C, △ for 180-170 ° C, and x for 170 ° C or lower. The lower limit fixing temperature was ◎ for 135 ° C. or less, ◯ for 135 to 145 ° C., Δ for 145 to 155 ° C., and × for 155 ° C. or more.

As can be seen with reference to Tables 1 and 2, toners 1 and 2 of the present invention shown in Examples 1 and 2 have a toner particle size distribution (Dv / Dn) smaller than 1.26. 25 or less (preferably less than 1.2), the acid value of the resin fine particles is in the range of more than 41 and less than 60, and the particle size of the resin fine particles is also in the range of more than 42 and less than 58. As a result, the charging property and the cleaning property were good, and no abnormal images such as background stains, white spots in the character portions, and fixing offset were generated.
On the other hand, in Comparative Example 1, the acid value and particle size of the resin fine particles are low. As can be seen from Tables 1 and 2, the toner of Comparative Example 2 has a high toner particle size distribution (Dv / Dn), image density, and image granularity. Occurrence of abnormal images such as the degree of sharpness, sharpness of characters, white spots of characters, and fixing offsets were observed.

1 is a schematic configuration diagram illustrating an example of an image forming apparatus according to the present invention.

Explanation of symbols

Developing device 10 Intermediate transfer belt (intermediate transfer member)
18 Image forming means 21 Exposure device 25 Fixing device 40 Photosensitive member (latent image carrier)
22 Secondary transfer device 62 Primary transfer means 100 Copier main body 200 Paper feed table 300 Scanner 400 Automatic document feeder

Claims (9)

At least, a polymer having a site reactive with a compound having an active hydrogen group, a toner set Narueki having a polyester and a colorant, an aqueous dispersion obtained by dispersing resin fine particles in water of water, organic solvents and surfactants A method for producing toner in which an aqueous medium prepared by mixing with a liquid mixture is brought into contact and granulated by performing at least one of a crosslinking reaction or an elongation reaction,
A toner production method , wherein the volume average particle size of resin fine particles in the aqueous dispersion is larger than 41 nm and smaller than 60 nm, and the acid value of the aqueous dispersion is larger than 42 mgKOH / g and smaller than 58 mgKOH / g. . The method for producing a toner according to claim 1, further comprising a step of dispersing the toner composition liquid in the aqueous medium. 3. The toner composition liquid according to claim 1 or 2, wherein the toner composition liquid further contains a release agent, and the release agent is at least one selected from carnauba wax, rice wax, and ester wax. A method for producing the toner according to the description. The binder resin of the toner composition liquid includes at least a polymer having a site capable of reacting with a compound having an active hydrogen group and polyester, and the toner composition liquid is contained in an aqueous medium containing the resin fine particles. method for producing a toner according to any one of claims 1 to 3, characterized in that at least one reaction of cross-linking reaction or elongation reaction in. A toner obtained by the method for producing a toner according to claim 1 . The toner has a volume average particle diameter of 3 to 8 μm, and a ratio (Dv / Dn) of volume average particle diameter (Dv) to number average particle diameter (Dn) is 1.25 or less. The toner according to claim 5 . The toner according to claim 5 , wherein the toner is a negatively charged toner. The toner according to claim 5 , wherein the toner has an average circularity of 0.94 or more. A developer for developing an electrostatic latent image, wherein the developer is a one-component developer using the toner according to claim 5 .

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