JP2007322473A - Toner for electrostatic charge image development - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a toner for electrostatic charge image development having excellent developability and thin wire reproducibility, and capable of stably forming a high definition image over a long period. <P>SOLUTION: In the toner for electrostatic charge image development at least comprising toner particles composed of a resin and a coloring agent, and an external additive, the external additive comprises inorganic particulates with the number average primary particle diameter of 5 to 30 nm, and a titanium oxide compound subjected to coupling agent treatment. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a toner for developing an electrostatic image.

  In recent years, image forming techniques such as copying machines, printers, and facsimiles have been remarkably developed, and the most frequently used one belongs to an image forming method using an electrostatic image represented by an electrophotographic system.

  This is because this image method can form high-quality images at high speed, can form not only monochrome images but also color images, and has durability and stability that can withstand long-term use. is there.

  However, the required level gradually increases, and what has been considered to be a sufficient level in the past is now required to be further improved. In particular, there is a high demand for image quality improvement, and for this reason, the tendency to make toner particles smaller is remarkable.

  It is difficult to impart a sufficient charge amount to the toner having a reduced particle size. The reason is that since the particles are small, the surface area is large, and the van der Waals force is also large, so that the particles do not sufficiently rub against the charge imparting member. For this reason, when toner having a small particle diameter is used, problems such as toner scattering and fogging often occur. Furthermore, although the resolution is expected to be improved due to the small particle size, the resolution is often not improved as expected.

  As an improvement means for such a problem, for example, as shown in Patent Document 1 and the like, resolution and durability have been improved by adding a titanate compound to sharpen the charge amount distribution as a toner. It was.

However, the stress on the developer has become stronger due to the increase in temperature in the machine accompanying further downsizing of the machine that has progressed in recent years and the pressure on the developer amount regulating part accompanying the increase in speed, etc. Under such circumstances, In addition, image problems such as toner scattering and fogging and resolution reduction have occurred. Particularly in the polymerized toner, the polar group on the toner surface is oriented and it is easy to take in water, so that there is a problem that these problems become more apparent especially in the output of an image in a high temperature and high humidity environment.
JP 2001-290302 A

  SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object thereof is to provide a toner for developing an electrostatic image that is excellent in developability and fine line reproducibility and can stably form a high-quality image over a long period of time. There is to do.

  The above object of the present invention is achieved by the following configurations.

  1. In an electrostatic charge image developing toner containing at least toner particles composed of a resin and a colorant and an external additive, the external additive is treated with inorganic fine particles having a number average primary particle size of 5 to 30 nm and a titanium treated with a coupling agent. An electrostatic charge image developing toner comprising an acid compound.

  2. 2. The electrostatic image developing toner according to 1 above, wherein the toner particles have an acid value of 5 to 30 KOHmg / g.

  3. 3. The electrostatic image developing toner according to 1 or 2 above, wherein the titanic acid compound has a number average primary particle diameter of 100 to 2000 nm.

  4). 4. The toner for developing an electrostatic charge image according to any one of 1 to 3 above, wherein the addition amount of the titanic acid compound is 0.1 to 10.0% by mass with respect to the toner particles.

  According to the present invention, it is possible to provide a toner for developing an electrostatic image that is excellent in developability and fine line reproducibility and can stably form a high-quality image over a long period of time.

  In view of the above problems, the present inventors have studied toner particles that easily contaminate the carrier, the developing sleeve, and the charge imparting member. As a result, the external additive containing inorganic fine particles having a specific particle diameter and a titanate compound treated with a coupling agent It has been found that by using an agent in combination, charging stability with a small particle size toner is ensured and the object of the present invention can be achieved, and the present invention has been completed.

  Hereinafter, the present invention will be described in detail.

[Titanate compound]
The present invention is characterized by containing a titanic acid compound treated with a coupling agent as one of external additives.

  The reason why the charge stabilizing effect of the titanic acid compound is great is not clear, but the reason is that it is a high dielectric. By using a titanic acid compound that is a high dielectric material, it is presumed that the chargeability-imparting ability of a small particle size toner can be expanded and the chargeability can be stabilized. Examples of titanate compounds include strontium titanate, barium titanate, calcium titanate, magnesium titanate and the like.

  The titanic acid compound has a number average primary particle size of 100 to 2000 nm, preferably 200 to 1000 nm. When this particle size is smaller than the above, the charge imparting ability is lowered, and the contribution to stabilization of chargeability may be lowered. On the other hand, when the particle size is larger than the above range, there is a problem that the toner particles are easily separated from the toner particles, the adhesion to the photoconductor is increased, and the photoconductor is easily damaged.

  The addition amount of the titanic acid compound is 0.1 to 10.0% by mass, preferably 0.3 to 5.0% by mass, and more preferably 0.4 to 2.0% by mass with respect to the toner particles. If the addition amount is less than this range, the effects such as charge stabilization may not occur, and if the addition amount exceeds this range, a phenomenon such as desorption of the titanate compound from the toner particles occurs, Problems such as scratches on the photoreceptor may occur.

  In addition, when the image forming process was repeated, toner particles having irregular shapes and toner particles having corner portions tended to be easily contaminated. Although the reason for this is not clear, when the toner particles are uneven in shape, the toner composition is susceptible to mechanical stress due to stirring or the like inside the developing device, and a portion to which excessive stress is applied is generated. Was transferred to the contaminated material and adhered, and the chargeability of the toner was estimated to change.

  Further, the difference in the manner in which stress is applied varies depending on the particle size of the toner particles, and the particles having a smaller particle size have a higher adhesive force, so that they are easily contaminated when subjected to stress. When the toner particle size is large, such contamination is less likely to occur, but there is a problem that the image quality such as resolution is lowered.

  Furthermore, for such contamination, the charge amount distribution of the initial electrostatic image developing toner (hereinafter also simply referred to as toner) is also important. When the charge amount distribution is wide, so-called selective development occurs in the image forming process, toner that is difficult to develop accumulates in the developing device and developability deteriorates, and the accumulated toner is stressed for a long period of time. As a result, there arises a problem that contamination occurs or the surface property of the toner changes to change the charging property, resulting in a weakly charged toner or a toner having a reverse polarity, resulting in a deterioration in image quality.

  As a result of examining the toner charge amount distribution, in order to make the toner charge amount distribution extremely sharp, it is necessary to control the variation in the particle size of the toner particles to be small and the shape variation to be small. It has been found. By making the toner charge amount distribution extremely sharp, even when the toner charge amount is set low, it is possible to obtain stable chargeability over a long period of time.

  As the toner having such characteristics, a polymerized toner can be used. However, because of the manufacturing method of the polymer toner, polar groups are easily oriented on the toner surface. Therefore, especially in a high temperature and high humidity environment, moisture in the air is adsorbed on the toner surface, so that the surface charge generation capability and charge retention The above problem has not been sufficiently improved due to a decrease in capacity.

  A stable image can be obtained by using a titanate compound subjected to the coupling agent treatment described in this patent for such toner.

  In this case, the acid value as the toner is preferably 5 to 30 KOHmg / g. When the acid value is larger than 30 KOHmg / g, image problems such as toner scattering and fogging due to a decrease in charging ability occur in a high temperature and high humidity environment.

  When the acid value is less than 5 KOHmg / g, image problems such as density reduction and halftone fading occur due to excessive charging in a low temperature and low humidity environment.

  The reason why the charge stabilizing effect of the titanic acid compound is great is not clear, but the reason is that it is a high dielectric. By using a titanic acid compound that is a high dielectric material, it is presumed that the chargeability-imparting ability of a small particle size toner can be expanded and the chargeability can be stabilized.

[Coupling agent]
As the coupling agent used for the treatment of the titanate compound coupling agent, alkylalkoxysilanes such as methyltrialkoxysilane, methyltriethoxysilane, ethyltriethoxysilane, hexyltrimethoxysilane, and octyltrimethoxysilane can be used. it can.

  Moreover, the coupling agent of following General formula (1) can also be used.

Formula _{(1) C n H 2n +} 1 -Si- (OC m H 2m + 1) 3
In the formula, n represents an integer of 4 to 12, and m represents an integer of 1 to 3. n is preferably an integer of 6 to 10, and m is preferably an integer of 1 to 2. Here, when n in the general formula (1) is smaller than 4, the treatment becomes easy, but the hydrophobicity cannot be sufficiently achieved. Moreover, when n is larger than 13, hydrophobicity is sufficient, but coalescence of titanium oxide particles increases, and fluidity imparting ability is lowered. On the other hand, if m is larger than 3, the reactivity is lowered and the hydrophobicity is not sufficiently performed.

  As a method of treating the coupling agent on the surface of the titanate compound, a general dry hydrophobization treatment method can be used.

  For example, the titanate compound is vigorously stirred in the presence of an acid or base, or under a temperature condition higher than the boiling point of the base, and the coupling agent is added as it is or diluted with a suitable solvent and added dropwise at a constant rate. In this case, an acid or base and a coupling agent may be mixed in advance and dropped together. After completion of the dropping, stirring is continued while maintaining the temperature for a while, and the coupling process ends. In addition to this method, there is a method in which a titanic acid compound, a coupling agent, an acid or base, and water vapor are co-flowed by an inert gas into a fluidized bed reaction vessel set at a high temperature to perform a coupling treatment. .

  The addition amount of the coupling agent contained on the titanic acid compound surface is preferably in the range of 0.01 to 10% by mass and more preferably in the range of 0.5 to 5% by mass with respect to the titanic acid compound amount. When the coupling agent is less than 0.01% by mass, the effect on the image quality stability under a high temperature and high humidity environment is insufficient, and when it exceeds 10% by mass, the coupling agent is liberated. There arises a problem that the chargeability is lowered.

[Inorganic fine particles]
The present invention is characterized by containing inorganic fine particles having a number average primary particle size of 5 to 30 nm as one of external additives.

  As examples of the inorganic fine particles, silica, alumina, titanium oxide and the like are preferable, and these inorganic fine particles are preferably hydrophobized with a silane coupling agent or a titanium coupling agent.

  The number average primary particle diameter of the inorganic fine particles is 5 to 30 nm. The particle diameter can be measured using a transmission electron microscope or a field effect scanning electron microscope.

〔resin〕
The resin constituting the toner according to the present invention is obtained by polyaddition or polycondensation reaction. In the present invention, the resin preferably contains 30% by mass or more.

  Here, the polycondensation reaction refers to a reaction in which a compound having a plurality of functional groups repeats the condensation reaction one after another while releasing a low molecular weight compound such as water or alcohol to form a polymer. Usually, examples of well-known polycondensation reactions include, for example, those in which water is released by the reaction of hexamethylenediamine and adipic acid to produce polyamide (66 nylon), or alcohols from ethylene glycol and terephthalic acid esters. The reaction which produces | generates polyester (polyethylene terephthalate) with elimination | elimination of is mentioned.

  On the other hand, the polyaddition reaction is a reaction in which a new bond is formed by performing an addition reaction between functional groups of a compound having a functional group, and this reaction is sequentially repeated to form a polymer. A polymer is produced without the release of a low molecular compound such as a condensation reaction.

  Further, as described above, the polyaddition reaction is different from the addition polymerization reaction such as radical polymerization because the reaction between functional groups is sequentially repeated. Usually, examples of well-known polyaddition reactions include those that form polyurethane from hexamethylene diisocyanate and tetramethylene glycol.

  As the resin (binder resin) which is a constituent material of the toner used in the present invention, any resin obtained by polyaddition or polycondensation reaction can be used as long as it can form a dispersion of resin particles in an aqueous medium. It may be a thing. For example, an amorphous polyester resin or a polyol resin can be cited as a typical example, but an amorphous polyester resin is more preferable.

(Amorphous polyester resin)
Examples of the divalent alcohol monomer for forming the amorphous polyester resin include polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane and polyoxypropylene (3.3). ) -2,2-bis (4-hydroxyphenyl) propane, polyoxyethylene (2.0) -bis (4-hydroxyphenyl) propane, polyoxypropylene (2.0) -polyoxyethylene (2.0) Etherified bisphenol such as -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene (6) -2,2-bis (4-hydroxyphenyl) propane, ethylene glycol, diethylene glycol, triethylene glycol, 1, 2-propylene glycol, 1,3-propylene glycol, 1,4-butanedio 1,4-butenediol, neopentyl glycol, 1,5-pentanediol, 1,6-hexanediol, 1,4-cyclohexanedimethanol, dipropylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, Examples thereof include bisphenol A and hydrogenated bisphenol A.

  Examples of the divalent carboxylic acid monomer include maleic acid, fumaric acid, citraconic acid, itaconic acid, glutaconic acid, phthalic acid, isophthalic acid, terephthalic acid, succinic acid, adipic acid, sebacic acid, azelaic acid, and malonic acid. , N-dodecyl succinic acid, n-dodecenyl succinic acid, isododecyl succinic acid, isododecenyl succinic acid, n-octyl succinic acid, n-octenyl succinic acid, anhydrides or lower alkyl esters of these acids, etc. Can do.

  In the present invention, a polyhydric alcohol monomer or a polycarboxylic acid monomer can be used.

  Examples of the trihydric or higher polyhydric alcohol monomer include sorbitol, 1,2,3,6-hexanetetrol, 1,4-sorbitan, pentaerythritol, dipentaerythritol, tripentaerythritol, 1,2,4. -Butanetriol, 1,2,5-pentanetriol, glycerol, 2-methylpropanetriol, 2-methyl-1,2,4-butanetriol, trimethylolethane, trimethylolpropane, 1,3,5-trihydroxy A methylbenzene etc. can be illustrated.

  Examples of the trivalent or higher polyvalent carboxylic acid monomer include 1,2,4-benzenetricarboxylic acid, 2,5,7-naphthalenetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid, 1,2,4. -Butanetricarboxylic acid, 1,2,5-hexanetricarboxylic acid, 1,3-dicarboxyl-2-methyl-2-methylenecarboxypropane, 1,2,4-cyclohexanetricarboxylic acid, tetra (methylenecarboxyl) methane, 1 2,7,8-octanetetracarboxylic acid, pyromellitic acid, emporic trimer acid, anhydrides or lower alkyl esters of these acids, and the like.

  For the purpose of blocking the polar group at the end of the polyester polymer and improving the environmental stability of the toner charging characteristics, a monofunctional monomer may be introduced into the polyester.

  Monofunctional monomers include benzoic acid, chlorobenzoic acid, bromobenzoic acid, parahydroxybenzoic acid, sulfobenzoic acid monoammonium salt, sulfobenzoic acid monosodium salt, cyclohexylaminocarbonylbenzoic acid, n-dodecylaminocarbonylbenzoic acid Acid, tertiary butylbenzoic acid, naphthalenecarboxylic acid, 4-methylbenzoic acid, 3-methylbenzoic acid, salicylic acid, thiosalicylic acid, phenylacetic acid, acetic acid, propionic acid, butyric acid, isobutyric acid, octanecarboxylic acid, lauric acid, stearyl Acids and monocarboxylic acids such as lower alkyl esters thereof, or monoalcohols such as aliphatic alcohols, aromatic alcohols and alicyclic alcohols can be used.

  Furthermore, the polyester resin used in the present invention may be modified so as to have a urethane bond in a molecular structure called urethane-modified polyester.

(Polyol resin)
Although various types of polyol resins can be used, the following are preferred as those used in the present invention.

  As a polyol resin, an epoxy resin, an alkylene oxide adduct of dihydric phenol or a glycidyl ether thereof, a compound having one active hydrogen in a molecule that reacts with an epoxy group, and an active hydrogen that reacts with an epoxy group in the molecule. It is preferable to use a polyol formed by reacting two or more compounds. Furthermore, the epoxy resin is particularly preferably at least two or more bisphenol A type epoxy resins having different number average molecular weights. This polyol resin imparts good gloss and transparency, and is effective in offset resistance.

  The epoxy resin used in the present invention is preferably obtained by binding bisphenol such as bisphenol A or bisphenol F and epichlorohydrin. The epoxy resin is at least two or more bisphenol A type epoxy resins having different number average molecular weights in order to obtain stable fixing characteristics and gloss. The low molecular weight component has a number average molecular weight of 360 to 2000, and has a high molecular weight component. The number average molecular weight is preferably 3000 to 10,000. Furthermore, it is preferable that a low molecular weight component is 20-50 mass% and a high molecular weight component is 5-40 mass%.

  In the toner according to the present invention, by using the bisphenol A type epoxy resin having the low molecular weight component and the high molecular weight component described above, a toner image having appropriate glossiness and good fixability can be obtained, and stable. A toner having the above storage performance is obtained.

  Examples of the compound used in the present invention, that is, the alkylene oxide adduct of dihydric phenol, include the following. Examples include reaction products of ethylene oxide, propylene oxide, butylene oxide, and mixtures thereof with bisphenols such as bisphenol A and bisphenol F. The resulting adduct may be used after glycidylation with epichlorohydrin or β-methylepichlorohydrin. In particular, diglycidyl ether of an alkylene oxide adduct of bisphenol A represented by the following general formula (2) is preferable.

(In the formula, n and m are the number of repeating units, each being 1 or more, and n + m = 2 to 6)
Moreover, it is preferable that 10-40 mass% of the alkylene oxide adduct of dihydric phenol or its glycidyl ether is contained with respect to polyol resin.

  When m and n as the number of repeating units have the above relationship, it was confirmed that a toner image having good gloss was obtained and that the storage stability of the toner was stabilized.

  Examples of the compound having one active hydrogen in the molecule that reacts with the epoxy group used in the present invention include monohydric phenols, secondary amines, and carboxylic acids.

  The following are illustrated as monohydric phenols. That is, phenol, cresol, isopropylphenol, aminophenol, nonylphenol, dodecylphenol, xylenol, p-cumylphenol and the like can be mentioned. Secondary amines include diethylamine, dipropylamine, dibutylamine, N-methyl (ethyl) piperazine, piperidine and the like. Examples of carboxylic acids include propionic acid and caproic acid.

  In order to obtain a polyol resin having an epoxy resin part and an alkylene oxide part in the main chain of the present invention, various raw material combinations are possible. For example, it can be obtained by reacting an epoxy resin having a glycidyl group at both ends and an alkylene oxide adduct of a dihydric phenol having both glycidyl groups with a dihalide, diisocyanate, diamine, dithiol, polyhydric phenol, or dicarboxylic acid. Among these, it is most preferable to react divalent phenol from the viewpoint of reaction stability. Moreover, it is also preferable to use polyhydric phenols and polyhydric carboxylic acids in combination with dihydric phenols as long as they do not gel. Here, the quantity of polyhydric phenols and polyhydric carboxylic acids is 15 mass% or less with respect to the whole quantity, Preferably it is 10 mass% or less.

  Examples of the compound having two or more active hydrogens in the molecule that react with the epoxy group used in the present invention include dihydric phenols, polyhydric phenols, and polycarboxylic acids. Examples of the dihydric phenol include bisphenols such as bisphenol A and bisphenol F. Examples of polyhydric phenols include orthocresol novolaks, phenol novolacs, tris (4-hydroxyphenyl) methane, and 1- [α-methyl-α- (4-hydroxyphenyl) ethyl] benzene. Examples of the polyvalent carboxylic acids include malonic acid, succinic acid, glutaric acid, adipic acid, maleic acid, fumaric acid, phthalic acid, terephthalic acid, trimellitic acid, and trimetic anhydride. In addition, when these polyester resins and polyol resins have a high crosslinking density, it becomes difficult to obtain transparency and glossiness, and preferably non-crosslinked or weakly crosslinked (THF insoluble content is 5% or less). preferable.

  Since it is not easy to adjust the acid value, the polyol resin is preferably used in combination with the polyester resin.

[Colorant]
The colorant used in the toner according to the present invention will be described.

  Examples of the black pigment used for the preparation of the black toner include carbon black such as furnace black, channel black, acetylene black, thermal black, and lamp black, and examples of the magnetic powder include magnetite and ferrite.

  These inorganic pigments can be used alone or in combination as desired. Further, the content of the inorganic pigment in the toner is preferably 2 to 20% by mass, and more preferably 3 to 15% by mass.

  When used as a magnetic toner, the above-mentioned magnetite can be added. In this case, the content in the toner is preferably 20 to 120% by mass from the viewpoint of developing predetermined magnetic characteristics.

  Conventionally known organic pigments and dyes used in the toner according to the present invention can be used, and specific organic pigments and dyes are exemplified below.

  Examples of the magenta or red organic pigment used in the magenta toner include C.I. I. Pigment red 2, C.I. I. Pigment red 3, C.I. I. Pigment red 5, C.I. I. Pigment red 6, C.I. I. Pigment red 7, C.I. I. Pigment red 15, C.I. I. Pigment red 16, C.I. I. Pigment red 48: 1, C.I. I. Pigment red 53: 1, C.I. I. Pigment red 57: 1, C.I. I. Pigment red 122, C.I. I. Pigment red 123, C.I. I. Pigment red 139, C.I. I. Pigment red 144, C.I. I. Pigment red 149, C.I. I. Pigment red 166, C.I. I. Pigment red 177, C.I. I. Pigment red 178, C.I. I. And CI Pigment Red 222.

  Examples of orange or yellow organic pigments used in yellow toner include C.I. I. Pigment orange 31, C.I. I. Pigment orange 43, C.I. I. Pigment yellow 12, C.I. I. Pigment yellow 13, C.I. I. Pigment yellow 14, C.I. I. Pigment yellow 15, C.I. I. Pigment yellow 17, C.I. I. Pigment yellow 93, C.I. I. Pigment yellow 94, C.I. I. Pigment yellow 138, C.I. I. Pigment yellow 180, C.I. I. Pigment yellow 185, C.I. I. Pigment yellow 155, C.I. I. And CI Pigment Yellow 156.

  Examples of the green or cyan organic pigment used in the cyan toner include C.I. I. Pigment blue 15, C.I. I. Pigment blue 15: 2, C.I. I. Pigment blue 15: 3, C.I. I. Pigment blue 16, C.I. I. Pigment blue 60, C.I. I. And CI Pigment Green 7.

  Examples of the dye include C.I. I. Solvent Red 1, 49, 52, 58, 63, 111, 122, C.I. I. Solvent Yellow 19, 44, 77, 79, 81, 82, 93, 98, 103, 104, 112, 162, C.I. I. Solvent Blue 25, 36, 60, 70, 93, 95 and the like. These dyes may be used alone or as a mixture of a plurality of dyes.

  The amount used is generally 1 to 20 parts by mass with respect to 100 parts by mass of the resin.

[Wax (release agent)]
In the present invention, it is preferable to include a wax in the toner in order to impart an appropriate release property to the developer. The wax has a melting point of 40 to 120 ° C., and preferably 50 to 110 ° C.

  It has been confirmed that by having the melting point within the above range, good fixability can be obtained even when the fixing temperature is set to a low temperature, and good offset resistance and durability can be obtained.

  The melting point of the wax can be obtained by differential scanning calorimetry (DSC). That is, the melting peak value when a sample of several mg is ripened at a constant temperature increase rate, for example, (10 ° C./min) is defined as the melting point.

  Examples of the release agent (wax) that can be used in the present invention include solid paraffin wax, micro wax, rice wax, fatty acid amide wax, fatty acid wax, aliphatic monoketone, coupling agent wax, and fatty acid ester. Waxes, partially saponified fatty acid ester waxes, higher alcohols, carnauba waxes and the like.

  Also, polyolefins such as low molecular weight polyethylene and polypropylene can be used. Particularly, a polyolefin having a softening point of 70 to 150 ° C. by the ring and ball method is preferable, and a polyolefin having a softening point of 120 to 150 ° C. is more preferable.

  Furthermore, the ester compound represented by following General formula (3) is mentioned.

Formula _{(3) R 1 - (OCO} -R 2) n
In the formula, each of R ₁ and R ₂ represents a hydrocarbon group having 1 to 40 carbon atoms which may have a substituent, and n represents an integer of 1 to 4.

  In the present invention, toner particles may be formed using a dispersion obtained by heating and stirring a wax in an aqueous medium using a surfactant or a dispersant. In this case, for example, a wax emulsion prepared by emulsifying wax can be prepared and added together with the colorant dispersion when the resin particles are aggregated.

  In the present invention, esters, waxes, amide waxes, carnauba waxes, and rice waxes are preferably used to prevent the wax particles from being released from the toner. Further, an acid-modified polyolefin wax is preferably used.

[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, Bontron 03 of nigrosine dye, Bontron P-51 of quaternary ammonium salt, Bontron S-34 of azo metal complex compound, E-82 of oxynaphthoic acid metal complex, E of salicylic acid metal complex -84, phenolic condensate E-89 (above, Orient Chemical Industries), quaternary ammonium salt molybdenum complex TP-302, TP-415 (above, Hodogaya Chemical Co., Ltd.), quaternary Copy charge PSY VP2038 of ammonium salt, copy blue PR of triphenylmethane derivative, copy charge NEGVP2036 of quaternary ammonium salt, copy charge NX VP434 (manufactured by Hoechst), LRA-901, LR-147 which is a boron complex (Nippon Carlit), copper phthalocyanine, perylene, quinacrid Emissions, azo pigments, sulfonate group, carboxyl group, and polymer compounds having a functional group such as a quaternary ammonium salt. Among these, azo metal complex compounds are preferable, and for example, those disclosed in paragraphs 0009 to 0012 of JP-A-2002-351150 are preferably used.

  In the present invention, the amount of charge control agent used is determined by the toner production method including the type of resin, the presence or absence of additives used as necessary, and the dispersion method, and is uniquely limited. However, it is preferably used in the range of 0.1 to 10 parts by mass with respect to 100 parts by mass of the resin. Preferably, the range of 0.2-5 mass parts is good. When the amount exceeds 10 parts by mass, the chargeability of the toner is too high, the effect of the main charge control agent is reduced, the electrostatic attraction force with the developing roller is increased, the flowability of the developer is reduced, and the image density Cause a decline.

  In the present invention, it is preferable to add a charge control agent in the vicinity of the toner particle surface. That is, by adding the toner particles in the vicinity of the toner particle surface, the toner particles can be effectively charged, and the charge control agent can be added so as not to expose the toner particle surface to ensure the fluidity of the toner. is there.

  As a specific content method, for example, there is a method of controlling the amount of charge control agent added to the resin particles constituting the toner particles. That is, a method in which a large amount of charge control agent is added to the resin particles constituting the vicinity of the surface of the toner particles, and the resin particles are aggregated so as to form the toner particle surface with the resin particles to which no charge control agent is added, And a method in which the resin particles containing the charge control agent are aggregated and then encapsulated with a resin component not containing the charge control agent on the surface of the aggregated particles.

  As a method of addition into the resin particles, it is preferable to knead together with the resin and adjust the dispersion diameter. However, when emulsified in an aqueous medium, the oil phase is eluted from the dispersed phase to the aqueous phase side or removed. In the case of separation, it may be added to the aqueous phase side and incorporated into the toner during the aggregation process or drying process.

(External additive)
As an external additive for assisting the fluidity, developability and chargeability of the toner particles obtained in the present invention, the above-mentioned inorganic fine particles having a number average primary particle diameter of 5 to 30 nm and titanic acid treated with a coupling agent are used. In addition to compounds, polymer fine particles, such as soap-free emulsion polymerization, suspension polymerization, and dispersion polymerization, polystyrene, methacrylic acid ester, acrylic acid ester copolymer, polycondensation systems such as silicone, benzoguanamine, and nylon, heat Examples thereof include polymer particles made of a curable resin.

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

  Examples of the cleaning property improver for removing the developer after transfer remaining on the photosensitive member or the primary transfer medium include coupling agents such as zinc stearate, calcium stearate, and stearic acid, such as polymethyl methacrylate fine particles, polystyrene fine particles, etc. And polymer fine particles produced by soap-free emulsion polymerization. The polymer fine particles preferably have a relatively narrow particle size distribution and a volume average particle size of 0.01 to 1 μm.

[Toner Production Method]
(Method of dispersing resin particles in an aqueous medium)
A method for producing a dispersion liquid in which resin particles are dispersed in an aqueous medium is not particularly limited, and examples thereof include the following methods.

(1) In the case of polyaddition or condensation polymerization resins such as polyester resins and polyol resins, the following methods are preferably used.
(A) Precursor (monomer, oligomer, etc.) or resin solvent solution is emulsified or dispersed in an aqueous medium in the presence of an appropriate dispersant such as an emulsifier, and then cured by heating or adding a curing agent. A method for producing an aqueous dispersion of resin particles,
(B) A suitable emulsifier is dissolved in a precursor (monomer, oligomer, etc.) or a resin solvent solution (which is preferably liquid but may be liquefied by heating), and then water is added to perform phase inversion. Emulsifying method,
(2) When a vinyl resin is used in combination, a resin is obtained by using a monomer as a starting material and generating resin particles by a polymerization reaction such as a suspension polymerization method, an emulsion polymerization method, a seed polymerization method or a dispersion polymerization method. A method for directly producing an aqueous dispersion of particles,
(3) A method in which a resin prepared in advance by a polymerization reaction (which may be any polymerization reaction mode such as polyaddition or condensation polymerization) is dispersed in an aqueous medium by the following method.
(A) The resin produced is pulverized using a mechanical pulverizer or jet type fine pulverizer and then spheroidized to obtain resin particles, which are then dispersed in water in the presence of an appropriate dispersant. Method,
(B) A method in which a resin solution obtained by dissolving the prepared resin in a solvent is sprayed in a mist to obtain resin particles, and then the resin particles are dispersed in water in the presence of a suitable dispersant,
(C) A poor solvent is added to a resin solution obtained by dissolving the prepared resin in a solvent, or a resin solution that has been heated and dissolved in a solvent in advance is cooled to precipitate resin particles, and then the solvent is removed to remove resin particles. A method of dispersing the resin particles in water in the presence of a suitable dispersant,
(D) A method in which a resin solution obtained by dissolving the prepared resin in a solvent is dispersed in an aqueous medium in the presence of an appropriate dispersant, and the solvent is removed by heating or decompression.
(E) A method in which a suitable emulsifier is dissolved in a resin solution obtained by dissolving the prepared resin in a solvent, and then water is added to perform phase inversion emulsification.
As the emulsifier or dispersant used in combination with the above method, known surfactants, water-soluble polymers and the like can be used. Moreover, a solvent, a plasticizer, etc. can be used together as an auxiliary agent for emulsification or dispersion. Specific examples include those disclosed in paragraphs 0036 to 0062 of JP-A-2002-284881.

  It is preferable to mix the materials mechanically and uniformly before the dispersion step. That is, a mixing step of mechanically mixing at least a binder resin, a colorant master batch, and, if necessary, a toner composition component including a charge control agent and a release agent is first required. This can be done under normal conditions using a normal mixer with rotating wings, and is not particularly limited.

  Resin or other toner material in an organic solvent is stirred with a normal impeller, heat-treated as necessary, dissolved and dispersed with a ball mill, sand mill, homogenizer, etc., and emulsified and dispersed in an aqueous medium. .

  At that time, an emulsifying device such as a homomixer (manufactured by Special Machine Engineering Co., Ltd.), Ebara Milder (manufactured by Ebara Seisakusho Co., Ltd.), Claremix (manufactured by M Technique Co., Ltd.) or the like is used. By controlling the concentration of the emulsifier, the concentration of the solid to the organic solvent, the ratio of the oily phase in which the aqueous medium and the solid are dispersed, the number of revolutions during the emulsification dispersion, and the time, the desired droplet size and particle size are controlled. Can be distributed. It is preferable to emulsify and disperse to 1/2 to 1/100 of the target toner particle diameter. The mass ratio between the solid and the organic solvent is preferably selected between 1:10 and 1: 1, and the mass ratio between the aqueous medium and the oily phase in which the solid is dispersed is preferably selected between 10: 1 and 1: 1. Of course, it may be outside this range.

  As an aqueous medium, organic solvents such as water, alcohols such as methanol and ethanol that can be partially mixed with water, ethanol such as ethanol, ketones such as acetone and methyl ethyl ketone, and ester solvents such as ethyl acetate are also used in combination with water. be able to.

  The organic solvent for dissolving and dispersing the solid toner component is not particularly limited as long as it is insoluble or hardly soluble in water and partially soluble and dissolves the resin. For example, toluene, xylene, Benzene, methyl acetate, ethyl acetate, methyl ethyl ketone, methyl isobutyl ketone and the like can be used alone or in combination of two or more. In particular, aromatic solvents such as toluene and xylene, tetrahydrofuran (THF), ether, and organic acid other than the above are preferred.

  Alkyl sulfates, alkyl benzene sulfonates, α-olefin sulfonates, phosphates, etc. as dispersants for emulsifying and dispersing the oily phase in which the toner component is dispersed in a liquid containing water to a desired particle size Nonionic surfactants such as anionic surfactants, fatty acid amide derivatives, and polyhydric alcohol derivatives.

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 perfluorooctanesulfonylglutamate, 3- (omega-fluoroalkyl (C _6- C ₁₁ ) oxy) -1-alkyl (C ₃ -C ₄ ) sodium sulfonate, 3- (omega-fluoroalkanoyl (C ₆ -C ₈ ) -N-ethylamino) -1-propanesulfonic acid sodium, fluoroalkyl (C ₁₁ ~C ₂₀₎ carboxylic acids and metal salts thereof, perfluoroalkyl carboxylic acids (C ₇ ~C ₁₃₎ and metal salts thereof, perfluoroalkyl (C ₄ ~C ₁₂₎ sulfonic acids and metal salts thereof, perfluorooctane Sulfonic acid diethanolamide, N-propyl-N- (2-hydroxyethyl) par Le Oro amide, perfluoroalkyl (C ₆ ~C ₁₀₎ sulfonamide propyl trimethyl ammonium salts, perfluoroalkyl (C ₆ ~C ₁₀₎ -N- ethylsulfonyl glycine salts, monoperfluoroalkyl (C ₆ -C ₁₆ ) Ethyl phosphate ester and the like.

  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 (manufactured by Taikin Kogyo Co., Ltd.), Mega-Fac F-ll0, F-120, 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 Fgentent F-100, F150 (manufactured by Neos).

  In addition, tricalcium phosphate, calcium carbonate, titanium oxide, colloidal silica, hydroxyapatite, and the like can also be used as an inorganic compound dispersant that is hardly soluble in water.

  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. At that time, it is preferable to carry out under reduced pressure because the heating temperature can be lowered. This is to prevent the wax and other toner constituents from dissolving in the organic solvent, and to prevent abnormal aggregation, association and coalescence due to heating of the emulsified dispersion. This organic solvent removal step may be performed before the aggregation step or after the aggregation step. If the organic solvent is removed before the aggregation step, fusion and coalescence of the fine particles after aggregation can be promoted.

  Another treatment method for those dissolved in an organic solvent is to spray the emulsified dispersion into a dry atmosphere to completely remove the water-insoluble organic solvent in the droplets to form toner fine particles, which are combined with an aqueous dispersion. It is also possible to evaporate and remove the agent. 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. Sufficient quality can be obtained with a short time treatment such as spray dryer, belt dryer, rotary kiln.

(Aggregating method of resin particles)
As agglomeration methods, when fine particles are dispersed in water with an electric charge, the particles are aggregated by applying an electrolyte or the like to compress the electric double layer, or a high molecular weight water-soluble polymer is By adsorbing and aggregating each other, or introducing a substance that is oppositely charged to the surfactant or dispersant used, the charge on the surface of the fine particles is neutralized and aggregated, or the adsorbed surfactant or dispersion A method is adopted in which the solubility of the surfactant or dispersant in the aqueous medium is changed by changing the counter ion of the agent or by introducing another substance into the aqueous medium to weaken the dispersion stability and cause aggregation. The

  In the present invention, the resin particles have a step of aggregating, but the resin particles used for aggregation in the present invention include those containing an organic solvent, for example, a resin solution liquid. Drops are also included in this category.

  At that time, it is agglomerated with the wax emulsion and the resin fine particles having the polar group described above to give the manufactured toner releasability at the time of fixing, to enhance the triboelectric chargeability, By disposing the high resin fine particles relatively outside the toner, blocking of the toners during high temperature storage can be prevented.

  Examples of the flocculant used include sodium sulfate, ammonium sulfate, potassium sulfate, magnesium sulfate, sodium phosphate, sodium dihydrogen phosphate, disodium hydrogen phosphate, ammonium chloride, calcium chloride, cobalt chloride, and strontium chloride. General inorganic or organic water-soluble salts represented by cesium chloride, barium chloride, nickel chloride, magnesium chloride, rubidium chloride, sodium chloride, potassium chloride, sodium acetate, ammonium acetate, potassium acetate, sodium benzoate, etc. Can be used. The concentration of these electrolytes ranges from 0.01 to 2.0 mol / l, more preferably from 0.1 to 1.0 mol / l, and even more preferably from 0.2 to 0.8 mol / l when a monovalent electrolyte is used. preferable. Furthermore, when a polyvalent electrolyte is used, the amount added may be smaller. In the case of a surfactant, those exemplified above, and in the case of a polymer-based aggregating agent, among those that form the above-mentioned polymer protective colloid, those of ultra high molecular weight are particularly suitable. In addition, as a substance to coagulate by coexisting in an aqueous medium, it is possible to use water-soluble organic compounds such as ethanol, butanol, isopropanol, ethyl cellosolve, butyl cellosolve, dioxane, tetrahydrofuran, acetone, methyl ethyl ketone, etc. it can.

  Further, by heating the dispersion liquid after aggregation, the fine particles can be fused to adjust the shape of the toner to be produced. The particles are spheroidized by the interfacial tension, but the particle shape can be arbitrarily adjusted from spherical to indeterminate depending on the heating temperature, the viscosity of the toner, the presence of an organic solvent, and the like.

  The obtained dispersion of aggregated particles is sprayed in a dry atmosphere to completely remove the water-insoluble organic solvent remaining in the aggregated particles to form toner fine particles, and the aqueous dispersant is evaporated together. It is also possible to remove it. As the dry atmosphere in which the dispersion of the aggregated particles is sprayed, a gas obtained by heating air, nitrogen, carbon dioxide gas, combustion gas, etc., especially various air currents heated to a temperature higher than the boiling point of the highest boiling solvent used are generally used. It is done. Sufficient quality can be obtained with a short time treatment such as spray dryer, belt dryer, rotary kiln. If the operation of re-dispersing (reslurry) by repeating solid-liquid separation before drying and adding washing water is repeated, the used dispersant and emulsifier can be almost removed.

  In addition, when using an acid such as calcium phosphate salt that is soluble in alkali as a dispersion stabilizer, the calcium phosphate salt is removed from the fine particles by a method such as washing with water after dissolving the calcium phosphate salt with an acid such as hydrochloric acid. To do. It can also be removed by an operation such as degradation with an enzyme.

  Generally, the particle size distribution after the agglomeration operation is narrow and can be used as a toner as it is. However, when the particle size distribution is wide and washing and drying are performed while maintaining the particle size distribution, the desired particle size distribution is classified in an air stream. Thus, the particle size distribution can be adjusted.

  In the classification operation, the fine particle portion can also 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 obtained unnecessary fine particles or coarse particles can be returned to the kneading step again and used for particle formation (re-kneading step or re-aggregation step). At that time, fine particles or coarse particles may be in a wet state. The dispersant used in the classification operation at this time can be removed simultaneously with unnecessary fine particles from the obtained dispersion.

  By mixing the obtained toner powder after drying with different kinds of particles such as release agent fine particles, charge control fine particles, fluidizing agent fine particles, and colorant fine particles, or by giving mechanical impact force to the mixed powder. By immobilizing and fusing on the surface, it is possible to prevent detachment of the 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.) is modified to reduce the grinding air pressure, hybridization system (manufactured by Nara Machinery Co., Ltd.), kryptron system (Manufactured by Kawasaki Heavy Industries, Ltd.), automatic mortar and the like.

[Physical properties and shape of toner particles]
The acid value of the toner particles of the present invention is preferably 5 to 30 KOH mg / g. In the present invention, by setting the acid value of the toner within the above-mentioned range, aggregation is performed in a state where the dispersion stability of the resin particles and the colorant particles is improved at the time of toner particle preparation, thereby solving the problems of the present invention. It is presumed that toner was obtained.

  In addition, the magnitude of the acid value can be adjusted to a desired value depending on the composition ratio of the acid component having a carboxyl group such as an acrylic acid monomer in the addition polymerization reaction, or in the multistage polymerization. . In addition, when a polycondensation reaction is used, it is obtained by introducing a polyfunctional acid such as trimellitic acid and stopping the reaction to such an extent that the crosslinking reaction does not proceed, and the ratio of the acid component to the alcohol component in the synthesis stage is obtained. Although control is possible, it can also be adjusted by changing the synthesis reaction conditions.

  In the present invention, the acid value means the number of mg of potassium hydroxide necessary to neutralize polar groups such as carboxyl groups contained in 1 g of resin and toner. The sample is dissolved in a benzene-ethanol mixed solvent or the like, and titrated with a potassium hydroxide solution with a known titer, and the neutralized amount is calculated.

  The specific measuring method can mention the method shown, for example by JIS-0070-1992.

  As for the shape of the toner of the present invention, when 2000 or more toner particles having a particle diameter of 1 μm or more are measured, the average value of circularity (shape factor) represented by the following formula is 0.95 to 0.99, more preferably 0.94 to 0.97.

Circularity = (perimeter of equivalent circle) / (perimeter of toner particle projection image)
= 2π × (particle projected area / π) ^1/2 / (periphery length of toner particle projected image)
Here, the equivalent circle is a circle having the same area as the toner particle projection image, and the equivalent circle diameter is the diameter of the equivalent circle.

  In addition, as a measuring method of the said circularity, it can measure by FPIA-2000 (made by Sysmec). At this time, the equivalent circle diameter is defined by the following equation.

Equivalent circle diameter = 2 × (projected area of particle / π) ^1/2
The toner of the present invention preferably has an average equivalent circle diameter of 2.6 to 7.4 μm and an inclination of circularity with respect to the equivalent circle diameter of −0.050 to −0.010. . More preferably, the average value of the equivalent circle diameter is 3.4 to 6.6 μm, and the inclination of the circularity with respect to the equivalent circle diameter is −0.040 to −0.020.

  The inclination of the equivalent circle diameter is measured by measuring the equivalent circle diameter of the toner particles with a flow particle image analyzer FPIA-2000, and the relationship with the corresponding circularity is represented by the horizontal axis: equivalent circle diameter (μm) -vertical. Axis: Draw as circularity, and see the linear correlation (y = αx + b), α is the slope of the equivalent circle diameter.

At this time, R ² (R squared) is preferably 0.35 to 0.95 from the viewpoint of improving charging uniformity and halftone uniformity. Here, R is represented by the following formula (I).

Formula (I) R = A / B
In the formula, A and B each represent the following formula.

A = nΣXY− (ΣXΣY)
B = (nΣX ² − (ΣX) ² ) × ((nΣY ² ) − (ΣY) ² )
X represents an equivalent circle diameter (μm), and Y represents circularity.

  In order to produce a toner having an equivalent circle diameter gradient, small-sized spherical toner particles may be mixed with irregularly large toner particles. Alternatively, when the toner particles are assembled by associating the resin particles, after adding the flocculant in the associating step, the shape of the stirring blade is appropriately selected, the stirring strength is controlled, and a condition in which shearing force is easily applied to the larger particles, A method of shifting to a filtration and drying process may also be used. Preferably, the toner production apparatus and the flow type particle image analysis apparatus described above are connected in-line, and production is performed while appropriately adjusting the conditions while monitoring the average value of the circularity and the inclination α.

  Preferably, after adding a stopping agent for stopping salting out / fusion, the toner particles are further grown by 0.2 to 1.0 μm, for example, by re-adding the salting-out agent or adding a surfactant. It can be controlled to enter.

Further, in the present invention, from the viewpoint of making the toner charge amount distribution suitable, the equivalent circle diameter d ₁₀ at 10 number% cumulatively and the equivalent circle diameter d ₉₀ at 90 number% cumulative from the small particle diameter side of the toner particles The ratio d ₉₀ / d ₁₀ is preferably 1.2 to 2.0. Especially preferably, it is 1.3-1.8. If it is within this range, it is possible to control the dustiness of the dots, and it is possible to obtain a high-quality image with high halftone uniformity.

(Developer)
The toner of the present invention can be used as a one-component developer or a two-component developer, but has a shape that easily rotates, a sufficient negative chargeability, and a high particle strength. Therefore, it is preferably used for a one-component developer. That is, in the toner according to the present invention, when an image is formed using a conventional associative toner as a one-component developer, the toner particles are not crushed by being pressed against the thin layer forming member, and are transferred to the developing roll. Stable image formation is possible without fusing or contamination by the toner pieces.

  When used as a one-component developer, a non-magnetic one-component developer or a magnetic one-component developer containing 0.1 to 0.5 μm of magnetic particles in the toner can be used. it can.

  In the present invention, it has been confirmed that the toner particles have high strength and a strong negative chargeability. From such characteristics, the toner according to the present invention is particularly useful as a non-magnetic one-component developer. Is preferred.

  The reason why the toner according to the present invention exhibits such characteristics is not clear, but is presumed to be as follows.

  First, the toner particles exhibit high strength because the resin particles (or resin solution droplets) are agglomerated while fusing at the molecular level when the toner particles are manufactured. It is presumed that high strength can be expressed.

  In addition, since the toner particles have a rounded shape close to a sphere, it is assumed that even if stress is applied to the toner particles, the toner particles are not destroyed by appropriately releasing the stress.

  Next, the reason why strong negative chargeability can be obtained is that the resin is made of a highly chargeable resin such as polyester, polyol, or polyurethane, and that the toner particles are rounded so that the toner particles are easy to rotate. This is presumed to be due to efficient charging.

  Furthermore, it has been confirmed that the resin constituting the toner particles according to the present invention is easily deformed after aggregation because of its low elastic modulus in an aqueous medium and exhibits an excellent effect on cleaning performance.

  The toner of the present invention can be mixed with a carrier that is magnetic particles and used as a two-component developer. As the carrier, conventionally known materials such as metals such as iron, ferrite, and magnetite, and alloys of these metals with metals such as aluminum and lead can be used. Among these, ferrite particles are preferable. The volume average particle diameter of the carrier is preferably 15 to 100 μm, more preferably 25 to 80 μm.

  The volume average particle diameter of the carrier can be typically measured by a laser diffraction particle size distribution measuring apparatus “Heros” (manufactured by Sympathic) equipped with a wet disperser.

  As the carrier, one obtained by coating magnetic particles with a resin, or a so-called resin-dispersed carrier in which magnetic particles are dispersed in a resin can also be used. Examples of the coating resin include olefin resins, styrene resins, styrene-acrylic resins, silicone resins, ester resins, and fluorine-containing polymer resins. Examples of the resin for constituting the resin-dispersed carrier include a styrene-acrylic resin, a polyester resin, a fluorine resin, and a phenol resin.

  EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto.

[Preparation of Toner 1]
(Preparation of toner base A)
<Preparation of latex 6HML>
(1) Preparation of core particles (first-stage polymerization): Preparation of latex 6H Anionic surfactant sodium lauryl sulfate in a 5000 ml separable flask equipped with a stirrer, temperature sensor, condenser, and nitrogen introducing device. A surfactant solution (aqueous medium) in which 08 g was dissolved in 3010 g of ion-exchanged water was charged, and the internal temperature was raised to 80 ° C. while stirring at a stirring speed of 230 rpm under a nitrogen stream.

  To this surfactant solution, an initiator solution prepared by dissolving 9.2 g of a polymerization initiator (potassium persulfate: KPS) in 200 g of ion-exchanged water was added, the temperature was adjusted to 75 ° C., and then 69.4 g of styrene, n -A monomer mixture composed of 28.3 g of butyl acrylate and 2.30 g of methacrylic acid was added dropwise over 1 hour, and polymerization (first stage polymerization) was performed by heating and stirring at 75 ° C for 2 hours. Latex (a dispersion of resin particles made of high molecular weight resin) was prepared. This is designated as “Latex 6H”.

(2) Formation of intermediate layer (second stage polymerization): Preparation of latex 6HM In a flask equipped with a stirrer, 97.1 g of styrene, 39.7 g of n-butyl acrylate, 3.22 g of methacrylic acid, n-octyl- 98.0 g of the compound A represented by the following formula is added as a crystalline substance to a monomer mixed liquid composed of 5.6 g of 3-mercaptopropionic acid ester, and the monomer is heated to 90 ° C. and dissolved. A solution was prepared.

  On the other hand, a surfactant solution in which 1.6 g of sodium lauryl sulfate was dissolved in 2700 ml of ion-exchanged water was heated to 98 ° C., and the latex (6H), which is a dispersion of core particles, was added to this surfactant solution as a solid content. After adding 28 g in terms of conversion, the monomer solution was mixed and dispersed for 8 hours by a mechanical disperser “CLEARMIX” (manufactured by M Technique Co., Ltd.) having a circulation path, and emulsified particles (oil droplets) A dispersion liquid (emulsion liquid) was prepared.

  Next, an initiator solution prepared by dissolving 5.1 g of a polymerization initiator (KPS) in 240 ml of ion exchange water and 750 ml of ion exchange water are added to this dispersion (emulsion). Polymerization (second-stage polymerization) was performed by heating and stirring for 12 hours to obtain latex (a dispersion of composite resin particles having a structure in which the surface of resin particles made of a high molecular weight resin was covered with an intermediate molecular weight resin). This is designated as “Latex 6HM”.

(3) Formation of outer layer (third stage polymerization): Preparation of latex 6HML Initiator obtained by dissolving 7.4 g of polymerization initiator (KPS) in 200 ml of ion-exchanged water in latex (6HM) obtained as described above. The monomer mixture liquid which consists of styrene 277g, n-butylacrylate 113g, methacrylic acid 9.21g, n-octyl-3-mercaptopropionic acid ester 10.4g under the temperature condition of 80 degreeC by adding a solution. It was added dropwise over time. After completion of the dropping, the mixture was heated and stirred for 2 hours to perform polymerization (third stage polymerization), and then cooled to 28 ° C. to obtain a latex. This latex is designated as “Latex 6HML”.

<Preparation of Toner Base A>
A toner base A of colored particles (black) was prepared as follows.

(1) Preparation of Colorant Dispersion 1 90 g of anionic surfactant sodium lauryl sulfate was stirred and dissolved in 1600 ml of ion-exchanged water. While stirring this solution, 400.0 g of carbon black (Regal 330R: manufactured by Cabot Corp.) was gradually added, and then dispersed using a stirring device “CLEARMIX” (manufactured by M Technique Co., Ltd.). Then, the dispersion was dispersed until the dispersed particle diameter became 200 nm or less to prepare a colorant dispersion (hereinafter referred to as “colorant dispersion 1”).

(2) (Aggregation / Fusion) Preparation of associated particles Latex 6HML 200g (converted to solid content), ion-exchanged water 3000g and "colorant dispersion 1" 71g, temperature sensor, cooling pipe, nitrogen introducing device, stirring device Was stirred in a reaction vessel (four-necked flask). After adjusting the temperature in the container to 30 ° C., 5 mol / liter sodium hydroxide aqueous solution was added to this solution to adjust the pH to 8 to 11.0. Next, an aqueous solution in which 20 g of magnesium chloride hexahydrate was dissolved in 20 ml of ion-exchanged water was added over 10 minutes at 30 ° C. with stirring. After standing for 3 minutes, heating was started, and the system was heated to 75 ° C. over 60 minutes. In this state, the particle size of the associated particles was measured with “Coulter Counter MS-II”. When the number average particle size reached 6 to 7 μm, an aqueous solution in which 29 g of sodium citrate was dissolved in 60 ml of ion-exchanged water was used. Addition was made to stop the particle growth, and the fusion was continued by heating and stirring at a liquid temperature of 90 ° C. for 6 hours as an aging treatment. Then, it cooled to 30 degreeC, hydrochloric acid was added, pH was adjusted to 2.0, and stirring was stopped. The generated salting-out, agglomeration, and fused particles are filtered, washed repeatedly with ion exchange water at 45 ° C., and then dried with hot air at 40 ° C. to obtain toner base A of colored particles (black). .

(Titanate compound treatment)
To the acid adjusted to pH 4 with 1 mol / L hydrochloric acid, strontium titanate (titanate compound) was added under a temperature condition higher than its boiling point, stirred vigorously, and 3% by mass with respect to strontium titanate diluted with toluene. Methyl trialkoxysilane (coupling agent) is added dropwise at a constant rate. After completion of the dropping, stirring was continued while maintaining the temperature for a while, and the coupling process was terminated. After sufficiently drying, the particles were sized using an airflow pulverizer to obtain a coupling-treated titanic acid compound.

(External addition processing to toner base A)
To the toner base A produced above, 2.0% by mass of a titanate compound treated with a coupling agent, 1.0% by mass of hydrophobic silica (TG-811F; manufactured by Cabosil), and NX90 (manufactured by Nippon Aerosil Co., Ltd.) 0% by mass was added and mixed with a Henschel mixer (Mitsui Mining Co., Ltd.). Thereafter, coarse particles were removed using a sieve having an opening of 45 μm, and Toner 1 was obtained.

[Production of Toners 2 to 10]
In preparation of toner 1, as shown in Table 1, toner base (type, acid value), titanic acid compound (type, number average primary particle radius, amount added to toner base) and coupling agent (type, titanic acid compound) Toners 2 to 10 were prepared in the same manner except that the addition amount was changed. The toner 10 was not treated with a coupling agent.

  A method for producing toner bases B to E used for the toners 2 to 10 will be described below.

(Preparation of toner base B)
<Preparation of latex 8HML>
(1) Preparation of core particles (first-stage polymerization): Preparation of latex 8H Anionic surfactant sodium lauryl sulfate in a 5000 ml separable flask equipped with a stirrer, a temperature sensor, a condenser tube and a nitrogen introducing device A surfactant solution (aqueous medium) in which 08 g was dissolved in 3010 g of ion-exchanged water was charged, and the internal temperature was raised to 80 ° C. while stirring at a stirring speed of 230 rpm under a nitrogen stream.

  To this surfactant solution, an initiator solution prepared by dissolving 9.2 g of a polymerization initiator (potassium persulfate: KPS) in 200 g of ion-exchanged water was added, the temperature was adjusted to 75 ° C., and then 70.3 g of styrene, n -A monomer mixture consisting of 28.7 g of butyl acrylate and 1.00 g of methacrylic acid was added dropwise over 1 hour, and this system was polymerized by heating and stirring at 75 ° C for 2 hours (first stage polymerization). And a latex (a dispersion of resin particles made of a high molecular weight resin) was prepared. This is designated as “Latex 8H”.

(2) Formation of intermediate layer (second stage polymerization): Preparation of latex 8HM In a flask equipped with a stirrer, 98.3 g of styrene, 40.2 g of n-butyl acrylate, 1.51 g of methacrylic acid, n-octyl- As a crystalline substance, 98.0 g of compound A was added to a monomer mixed solution composed of 5.6 g of 3-mercaptopropionic acid ester, and the mixture was heated to 90 ° C. and dissolved to prepare a monomer solution.

  On the other hand, a surfactant solution in which 1.6 g of sodium lauryl sulfate was dissolved in 2700 ml of ion-exchanged water was heated to 98 ° C., and the latex (5H), which is a dispersion of core particles, was added to the surfactant solution. After adding 28 g in terms of conversion, the monomer solution was mixed and dispersed for 8 hours by a mechanical disperser “CLEARMIX” (manufactured by M Technique Co., Ltd.) having a circulation path, and emulsified particles (oil droplets) A dispersion liquid (emulsion liquid) was prepared.

  Next, an initiator solution prepared by dissolving 5.1 g of a polymerization initiator (KPS) in 240 ml of ion exchange water and 750 ml of ion exchange water are added to this dispersion (emulsion). Polymerization (second-stage polymerization) was performed by heating and stirring for 12 hours to obtain latex (a dispersion of composite resin particles having a structure in which the surface of resin particles made of a high molecular weight resin was covered with an intermediate molecular weight resin). This is designated as “Latex 8HM”.

(3) Formation of outer layer (third stage polymerization): Preparation of latex 8HML Initiator obtained by dissolving 7.4 g of polymerization initiator (KPS) in 200 ml of ion-exchanged water in latex (8HM) obtained as described above. The monomer mixture liquid which consists of 283g of styrene, 115g of n-butylacrylate, 4.30g of methacrylic acid, and 10.4g of n-octyl-3-mercaptopropionic acid ester under the temperature condition of 80 degreeC is added. It was added dropwise over time. After completion of the dropping, the mixture was heated and stirred for 2 hours to perform polymerization (third stage polymerization), and then cooled to 28 ° C. to obtain a latex. This latex is designated as “Latex 8HML”.

<Preparation of Toner Base B>
Toner base B was prepared in the same manner as toner base A, except that latex 6HML was changed to latex 8HML.

(Preparation of toner base C)
<Preparation of latex 4HML>
(1) Preparation of core particles (first stage polymerization): Preparation of latex 4H Anionic surfactant sodium lauryl sulfate in a 5000 ml separable flask equipped with a stirrer, a temperature sensor, a condenser tube and a nitrogen introducing device. A surfactant solution (aqueous medium) in which 08 g was dissolved in 3010 g of ion-exchanged water was charged, and the internal temperature was raised to 80 ° C. while stirring at a stirring speed of 230 rpm under a nitrogen stream.

  To this surfactant solution, an initiator solution prepared by dissolving 9.2 g of a polymerization initiator (potassium persulfate: KPS) in 200 g of ion-exchanged water was added, the temperature was adjusted to 75 ° C., and then 74.5 g of styrene, n -A monomer mixture composed of 21.6 g of butyl acrylate and 1.93 g of acrylic acid was added dropwise over 1 hour, and the system was polymerized by heating and stirring at 75 ° C for 2 hours (first stage polymerization). And a latex (a dispersion of resin particles made of a high molecular weight resin) was prepared. This is designated as “Latex 4H”.

(2) Formation of intermediate layer (second stage polymerization): Preparation of latex 4HM In a flask equipped with a stirrer, 104 g of styrene, 30.2 g of n-butyl acrylate, 2.7 g of acrylic acid, n-octyl-3- As a crystalline substance, 98.0 g of compound A was added to a monomer mixed solution composed of 5.6 g of mercaptopropionic acid ester, and the mixture was heated to 90 ° C. and dissolved to prepare a monomer solution.

  On the other hand, a surfactant solution in which 1.6 g of sodium lauryl sulfate was dissolved in 2700 ml of ion-exchanged water was heated to 98 ° C., and the latex 4H as a dispersion of core particles was added to this surfactant solution in terms of solid content. After adding 28 g, the monomer solution was mixed and dispersed for 8 hours with a mechanical disperser “CLEARMIX” (manufactured by M Technique Co., Ltd.) having a circulation path, and emulsified particles (oil droplets) were dispersed. A dispersion (emulsion) containing was prepared.

  Next, an initiator solution prepared by dissolving 5.1 g of a polymerization initiator (KPS) in 240 ml of ion exchange water and 750 ml of ion exchange water are added to this dispersion (emulsion), and the mixture is added at 98 ° C. for 12 hours. Polymerization (second-stage polymerization) was performed by heating and stirring to obtain latex (a dispersion of composite resin particles having a structure in which the surface of resin particles made of a high molecular weight resin was coated with an intermediate molecular weight resin). This is designated as “Latex 4HM”.

(3) Preparation of latex 4HML (formation of outer layer: third stage polymerization)
An initiator solution prepared by dissolving 7.4 g of a polymerization initiator (KPS) in 200 ml of ion-exchanged water was added to the latex 4HM obtained as described above, and styrene 306 g, n- A monomer mixed solution consisting of 88.5 g of butyl acrylate, 17.4 g of acrylic acid and 10.4 g of n-octyl-3-mercaptopropionic acid ester was added dropwise over 2 hours. After completion of the dropping, the mixture was heated and stirred for 2 hours to perform polymerization (third stage polymerization), and then cooled to 28 ° C. to obtain a latex. This latex is designated “Latex 4HML”.

<Preparation of toner base C>
Toner base C was prepared in the same manner as toner base A, except that latex 6HML was changed to latex 4HML.

(Preparation of toner base D)
<Preparation of latex 12HML>
(1) Preparation of core particles (first-stage polymerization): Preparation of latex 12H Anionic surfactant sodium lauryl sulfate in a 5000 ml separable flask equipped with a stirrer, a temperature sensor, a condenser tube, and a nitrogen introducing device. A surfactant solution (aqueous medium) in which 08 g was dissolved in 3010 g of ion-exchanged water was charged, and the internal temperature was raised to 80 ° C. while stirring at a stirring speed of 230 rpm under a nitrogen stream.

  To this surfactant solution, an initiator solution prepared by dissolving 9.2 g of a polymerization initiator (potassium persulfate: KPS) in 200 g of ion-exchanged water was added, the temperature was adjusted to 75 ° C., and then 70.7 g of styrene, n -A monomer mixture composed of 28.9 g of butyl acrylate and 0.386 g of acrylic acid was added dropwise over 1 hour, and this system was polymerized by heating and stirring at 75 ° C for 2 hours (first stage polymerization). And a latex (a dispersion of resin particles made of a high molecular weight resin) was prepared. This is designated as “Latex 12H”.

(2) Formation of intermediate layer (second stage polymerization): Preparation of latex 12HM In a flask equipped with a stirrer, 99.0 g of styrene, 40.4 g of n-butyl acrylate, 0.54 g of acrylic acid, n-octyl- As a crystalline substance, 98.0 g of compound A was added to a monomer mixed solution composed of 5.6 g of 3-mercaptopropionic acid ester, and the mixture was heated to 90 ° C. and dissolved to prepare a monomer solution.

  On the other hand, a surfactant solution in which 1.6 g of sodium lauryl sulfate was dissolved in 2700 ml of ion-exchanged water was heated to 98 ° C., and the latex 12HM as a dispersion of core particles was added to this surfactant solution in terms of solid content. After adding 28 g, the monomer solution was mixed and dispersed for 8 hours with a mechanical disperser “CLEARMIX” (manufactured by M Technique Co., Ltd.) having a circulation path, and emulsified particles (oil droplets) were dispersed. A dispersion (emulsion) containing was prepared.

  Next, an initiator solution prepared by dissolving 5.1 g of a polymerization initiator (KPS) in 240 ml of ion exchange water and 750 ml of ion exchange water are added to this dispersion (emulsion). Polymerization (second-stage polymerization) was performed by heating and stirring for 12 hours to obtain latex (a dispersion of composite resin particles having a structure in which the surface of resin particles made of a high molecular weight resin was covered with an intermediate molecular weight resin). This is designated as “Latex 12HM”.

(3) Formation of outer layer (third stage polymerization): Preparation of latex 12HML An initiator solution in which 7.4 g of a polymerization initiator (KPS) was dissolved in 200 ml of ion-exchanged water in latex 12HM obtained as described above. And a monomer mixture composed of 281 g of styrene, 114.8 g of n-butyl acrylate, 1.54 g of acrylic acid, and 10.4 g of n-octyl-3-mercaptopropionic acid ester under a temperature condition of 80 ° C. It was dripped over 2 hours. After completion of the dropping, the mixture was heated and stirred for 2 hours to perform polymerization (third stage polymerization), and then cooled to 28 ° C. to obtain a latex. This latex is designated “latex 12HML”.

<Preparation of toner base D>
Toner base D was prepared in the same manner as toner base A, except that latex 6HML was changed to latex 12HML.

(Preparation of toner base E)
(1) Preparation of core particles (first stage polymerization): Preparation of latex 9H Anionic surfactant sodium lauryl sulfate in a 5000 ml separable flask equipped with a stirrer, a temperature sensor, a condenser tube, and a nitrogen introducing device. A surfactant solution (aqueous medium) in which 08 g was dissolved in 3010 g of ion-exchanged water was charged, and the internal temperature was raised to 80 ° C. while stirring at a stirring speed of 230 rpm under a nitrogen stream.

  To this surfactant solution, an initiator solution in which 9.2 g of a polymerization initiator (potassium persulfate: KPS) was dissolved in 200 g of ion-exchanged water was added, the temperature was adjusted to 75 ° C., and then 67.8 g of styrene, n -A monomer mixture composed of 27.7 g of butyl acrylate and 4.50 g of methacrylic acid was added dropwise over 1 hour, and this system was heated and stirred at 75 ° C for 2 hours to polymerize (first stage polymerization) And a latex (a dispersion of resin particles made of a high molecular weight resin) was prepared. This is designated as “Latex 9H”.

(2) Formation of intermediate layer (second stage polymerization): Preparation of latex 9HM In a flask equipped with a stirrer, 94.1 g of styrene, 38.4 g of n-butyl acrylate, 7.53 g of methacrylic acid, n-octyl- As a crystalline substance, 98.0 g of compound A was added to a monomer mixed solution composed of 5.6 g of 3-mercaptopropionic acid ester, and the mixture was heated to 90 ° C. and dissolved to prepare a monomer solution.

  On the other hand, a surfactant solution in which 1.6 g of sodium lauryl sulfate was dissolved in 2700 ml of ion-exchanged water was heated to 98 ° C., and the latex 9H as a dispersion of core particles was added to this surfactant solution in terms of solid content. After adding 28 g, the monomer solution was mixed and dispersed for 8 hours with a mechanical disperser “CLEARMIX” (manufactured by M Technique Co., Ltd.) having a circulation path, and emulsified particles (oil droplets) were dispersed. A dispersion (emulsion) containing was prepared.

  Next, an initiator solution prepared by dissolving 5.1 g of a polymerization initiator (KPS) in 240 ml of ion exchange water and 750 ml of ion exchange water are added to this dispersion (emulsion). Polymerization (second-stage polymerization) was performed by heating and stirring for 12 hours to obtain latex (a dispersion of composite resin particles having a structure in which the surface of resin particles made of a high molecular weight resin was covered with an intermediate molecular weight resin). This is designated as “Latex 9HM”.

(3) Formation of outer layer (third stage polymerization): Preparation of latex 9HML An initiator solution in which 7.4 g of a polymerization initiator (KPS) was dissolved in 200 ml of ion-exchanged water in latex 9HM obtained as described above was prepared. And a monomer mixture consisting of 269 g of styrene, 110 g of n-butyl acrylate, 21.5 g of methacrylic acid, and 10.4 g of n-octyl-3-mercaptopropionic acid ester at 80 ° C. over 1 hour. And dripped. After completion of the dropping, the mixture was heated and stirred for 2 hours to perform polymerization (third stage polymerization), and then cooled to 28 ° C. to obtain a latex. This latex is designated “latex 9HML”.

<Preparation of toner base E>
Toner base E was prepared in the same manner as in the preparation of toner base A, except that latex 6HML was changed to latex 9HML.

[Evaluation of toner]
(Measurement of acid value)
The produced toner was measured according to JIS-0070-1992.

  In addition, the produced toner was left in a high temperature and high humidity environment (30 ° C., 85% RH) for 24 hours using a full color printer Magiccolor 2300DL (manufactured by Konica Minolta Business Technologies Co., Ltd.) equipped with a non-magnetic one-component device, and then the B / W ratio. Print 5000 sheets and 10,000 sheets of 6% print pattern, leave it in a low-temperature and low-humidity environment (10 ° C, 15% RH) for 24 hours, print 10,000 sheets of print pattern with 6% B / W ratio, The image density, fog (half-tone blurring and point-like defects in a low temperature and low humidity environment) were evaluated as follows.

(Image density)
At the end of printing, the absolute density of the solid image portion on the paper was measured using a Macbeth reflection densitometer “RD-918”.

(Fog)
At the end of printing durability, the relative density to the paper was measured.

  The absolute image density at 20 locations is measured using a Macbeth reflection densitometer “RD-918” and averaged to obtain a blank paper density value. Next, the absolute density at 20 locations was similarly measured and averaged for the white background portion of the evaluation image, and the value obtained by subtracting the white paper density value from this average density background was evaluated as the fog density. If the fog density is 0.010 or less, it can be said that there is no practical problem.

(Scratch)
At the end of printing durability, the case where no blurring occurred in the halftone portion of the image was marked with ◎, the case where there was a slight occurrence but no problem in practical use was marked with ○, and the case where there was a problem was marked with ×.

(Spot defect)
At the end of printing durability, a solid image was output and image defects due to scratches on the photoreceptor were visually confirmed.

  The evaluation results are shown in Table 2.

  From the table, it can be seen that the toner of the present invention is excellent in image density, fogging, blurring, and point-like defects, and can stably form a high-quality image over a long period of time.

Claims (4)

In an electrostatic charge image developing toner containing at least toner particles composed of a resin and a colorant and an external additive, the external additive is treated with inorganic fine particles having a number average primary particle size of 5 to 30 nm and a titanium treated with a coupling agent. An electrostatic charge image developing toner comprising an acid compound. 2. The electrostatic image developing toner according to claim 1, wherein the toner particles have an acid value of 5 to 30 KOHmg / g. 3. The electrostatic image developing toner according to claim 1, wherein the titanic acid compound has a number average primary particle diameter of 100 to 2000 nm. The electrostatic image developing toner according to claim 1, wherein the addition amount of the titanic acid compound is 0.1 to 10.0 mass% with respect to the toner particles.