JP2005208552A - Magnetic toner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a magnetic toner providing a stable image density without dependence on environment and also providing high-grade images over a long period of time without causing scratches of latent image bearing members. <P>SOLUTION: In the magnetic toner containing at least a binder resin and a magnetic material, the binder resin is chiefly composed of a resin having a polyester unit synthesized using as a catalyst a tin compound represented by a formula (1), (RCOO)<SB>2</SB>Sn, wherein R represents a 5-15C alkyl. The magnetic material has a number-average particle diameter of 0.1-0.3 μm. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a magnetic toner used in a recording method using an electrophotographic method, an electrostatic recording method, an electrostatic printing method, or a toner jet recording method.

  Conventionally, as an electrophotographic method, a photoconductive material is used, an electric latent image is formed on a photoreceptor by various means, and then the latent image is developed with toner, and a paper sheet is used as necessary. A method is known in which a toner image is transferred to a transfer material and then fixed by heating, pressure, heating and pressurization, or solvent vapor to obtain a toner image.

  In the method of developing the toner, a magnetic one-component developing system using a magnetic toner is preferably used because it does not require a carrier and is advantageous in downsizing the apparatus. In the toner used for the magnetic one-component development system, a considerable amount of fine powdered magnetic material is mixed and dispersed, and this presence state greatly affects the fluidity and triboelectric charging property of the toner. In a magnetic toner, a magnetic material is often used as a colorant as it is, and in order to improve the coloring power of the toner, it is important to reduce the particle size of the magnetic material and to achieve uniform dispersion. However, when the magnetic material is reduced in size, it tends to be reddish, and it becomes very difficult to uniformly disperse it in the toner, so that various problems are likely to occur.

  For example, if the toner particle size is reduced in order to improve dot reproducibility in a digital machine or the like, if the dispersibility of the magnetic material is insufficient, toner containing a large amount of magnetic material accumulates on the toner carrier (developing sleeve). In some cases, however, a decrease in image density and occurrence of shading unevenness called sleeve ghost are observed. In addition, the magnetic material is easily peeled off by rubbing between the toners or the regulating member, and the detached magnetic material damages the latent image carrier to cause an image defect.

  On the other hand, proposals regarding magnetic iron oxide contained in the magnetic toner have been made, but there are still points to be improved.

  There is also a proposal regarding a magnetic toner containing magnetic iron oxide containing silicon element (see, for example, Patent Document 1). In such magnetic iron oxide, silicon element is consciously present in the magnetic iron oxide, but there is still a point to be improved in the fluidity of the magnetic toner containing the magnetic iron oxide. There is also a proposal for controlling the shape of magnetic iron oxide to be spherical by adding silicate (see, for example, Patent Document 2). The magnetic iron oxide obtained by this method uses silicate to control the particle shape, so that a large amount of silicon element is distributed inside the magnetic iron oxide, and the amount of silicon element present on the magnetic iron oxide surface is small. Since the smoothness of the magnetic iron oxide is high, the fluidity of the magnetic toner is improved to some extent, but the adhesion between the binder resin constituting the magnetic toner and the magnetic iron oxide is insufficient.

  On the other hand, examples of the binder resin contained in the toner include styrene resins, polyester resins, and epoxy resins, and polyester resins are preferably used from the viewpoint of low-temperature fixability. Recently, a method in which two or more kinds of polyester resins having different softening points are mixed to expand the fixing region has been studied. As described above, when a plurality of resins are used for the magnetic toner, it becomes more strict to uniformly disperse the magnetic material in the hot melt kneading process at the time of toner production.

  In order to improve the dispersibility of magnetic materials, several studies have been made on such problems. For example, an attempt has been made to improve dispersibility by combining a specific polyester resin and a magnetic material having carbon black adsorbed on the surface (see, for example, Patent Document 3).

However, it is still insufficient when the toner has a small particle size or when a magnetic material having a small particle size is used.
JP 62-279352 A Japanese Patent Publication No. 3-9045 JP 2001-296689 A

  An object of the present invention is to provide a toner that solves the above-described problems, and to provide a magnetic toner that can obtain a stable image density regardless of the environment.

  It is a further object of the present invention to provide a magnetic toner capable of obtaining a high-quality image over a long period of time without causing damage to the latent image carrier.

  A further object of the present invention is to provide a magnetic toner having high coloring power and low toner consumption.

The present invention is a resin having a polyester unit in which a main component of the binder resin is synthesized using a tin compound represented by the following formula (1) as a catalyst in a magnetic toner containing at least a binder resin and a magnetic substance. And a magnetic toner wherein the number average particle size of the magnetic material is 0.1 to 0.3 μm.
(RCOO) ₂ Sn Formula (1)
(Wherein R represents an alkyl group having 5 to 15 carbon atoms)

  According to the present invention, the uniform dispersibility of the small particle size magnetic material in the resin is improved, a stable image density can be obtained, and a high-quality image can be obtained over a long period of time. Further, according to the present invention, the toner having a small particle size has good dispersibility of the internal additive, has excellent low-temperature fixability, and can be obtained without contamination of the developing sleeve and the fixing roller even in long-term durability. Can do.

  According to the present invention, the uniform dispersibility of the small particle size magnetic material in the resin is improved, a stable image density can be obtained, and a high-quality image can be obtained over a long period of time. In addition, according to the present invention, a toner having good dispersibility of the internal additive and excellent low-temperature fixability even in a toner having a reduced particle diameter, and capable of suppressing development sleeve / fixing roller contamination even in a long-term durability is obtained. be able to.

In the resin having a polyester unit in the present invention, the following formula (1)
(RCOO) ₂ Sn Formula (1)
A tin compound represented by the formula (hereinafter sometimes simply referred to as “tin compound”) is used as a catalyst. This tin compound is a suitable catalyst in the esterification reaction and transesterification reaction, and it is easy to adjust the softening point and physical properties of the resin, and enables polymerization in a relatively short time. Further, the presence of the tin compound in the resin having the polyester unit after polymerization improves the dispersibility and adhesion between the resin and the magnetic substance by the effects described below in the hot melt kneading step during toner production. it is conceivable that.

  As the first effect, due to the effect of the alkyl carboxylic acid component (RCOO-) bonded to tin, the magnetic substance is easily dispersed uniformly by locally reducing the viscosity of the polyester resin during hot melt kneading, In addition, the presence of the inorganic tin compound reduces the magnetic cohesiveness of the magnetic material and improves the fine dispersion of the magnetic material in the resin. In particular, when a small particle size magnetic material having a number average particle size of 0.1 to 0.3 μm is used, the uniform dispersibility in the resin is dramatically improved, and there is little change in charging characteristics due to the environment. It is possible to obtain a toner having high coloring power without causing detachment of the magnetic substance.

  The second effect of the alkylcarboxylic acid component (RCOO-) bonded to tin used in the present invention is to improve the dispersibility of the release agent in the resin containing the polyester unit. This is because, in a resin containing a polyester unit, which is inherently disadvantageous in terms of compatibility with the release agent, an alkylcarboxylic acid component having a structure similar to that of the release agent is formed between the resin and the release agent. By acting as a compatibilizer, the release agent can be uniformly dispersed in the resin containing the polyester unit. This is particularly effective when a low melting point release agent having a melting point of 70 to 120 ° C. as used in the present invention is used.

  The low melting point release agent has good low-temperature fixability, but in order to lower the viscosity of the toner, if the dispersibility in the toner is poor, it will release when used for a long time under severe conditions such as high temperature and high humidity. The toner containing a large amount of the agent and the release agent adheres to the sleeve by heat and pressure due to friction, and the toner further adheres to the core as a result of which the contamination easily develops. In addition, since the compatibility with the resin containing the polyester unit is poor, in the toner using the resin containing the polyester unit, the dispersed particle size and the surface presence rate are likely to be non-uniform, and a sufficient release effect is obtained. It's hard to be done. However, according to the present invention, the low melting point release agent is uniformly dispersed in the toner due to the above-described effects, so that there is little change in the composition of the toner due to environmental fluctuations and long-term durability, and excellent low temperature fixability and high release effect. It can be demonstrated.

  Here, the number of carbon atoms of the alkyl group of the alkylcarboxylate tin compound used in the present invention is optimally 5 to 15 from the viewpoint of the catalytic effect on the esterification reaction.

  Further, the addition amount of the tin compound is 0.05 to 2.0 parts by mass, preferably 0.1 to 1.0 part by mass with respect to 100 parts by mass of the binder resin. If the amount is less than 0.05 parts by mass, the reaction time at the time of polyester polymerization becomes longer, and the effect of improving the dispersibility of the magnetic substance cannot be obtained. On the other hand, if the content exceeds 2 parts by mass, the charging characteristics of the toner will be affected, and the variation in the charge amount due to the environment tends to increase.

The following are mentioned as a tin compound represented by Formula (1) preferably used in this invention.
Exemplary Compound (1) Tin Hexanoate [CH ₃ (CH ₂ ) ₄ COO] ₂ Sn
Exemplary Compound (2) Tin Octanoate [CH ₃ (CH ₂ ) ₆ COO] ₂ Sn
Exemplary Compound (3) Tin 2-ethylhexanoate

Exemplary Compound (4) Tin Decanoate [CH ₃ (CH ₂ ) ₈ COO] ₂ Sn
Exemplary Compound (5) Tin Laurate [CH ₃ (CH ₂ ) ₁₀ COO] ₂ Sn

  The binder resin used in the present invention is mainly composed of a resin having a polyester unit, and a polyester resin and a hybrid resin in which the polyester unit and the styrene-acrylic resin unit are chemically bonded are preferable. Is. In the present invention, the “main component of the binder resin” is defined as a component occupying more than 50% by mass in the binder resin.

  The following are mentioned as a monomer for obtaining a polyester resin or a polyester unit.

  Examples of the divalent alcohol component include ethylene glycol, propylene glycol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, diethylene glycol, triethylene glycol, 1,5-pentanediol, 1, 6-hexanediol, neopentyl glycol, 2-ethyl-1,3-hexanediol, hydrogenated bisphenol A, bisphenol derivatives represented by the following formula (a), and diols represented by the following formula (a): Can be mentioned.

  Divalent carboxylic acids include benzene dicarboxylic acids such as phthalic acid, terephthalic acid, isophthalic acid, and phthalic anhydride, or anhydrides thereof; alkyl dicarboxylic acids such as succinic acid, adipic acid, sebacic acid, azelaic acid, or the like. An succinic acid substituted with an alkyl group or an alkenyl group having 6 to 18 carbon atoms or an anhydride thereof; an unsaturated dicarboxylic acid such as fumaric acid, maleic acid, citraconic acid, itaconic acid, or an anhydride thereof; Can be mentioned.

  Examples of other monomers for obtaining a polyester resin or polyester resin unit include glycerin, pentaerythritol, sorbit, sorbitan, and polyhydric alcohols such as oxyalkylene ethers of novolac-type phenol resins; trimellitic acid, pyro Examples thereof include polyvalent carboxylic acids such as merit acid, benzophenone tetracarboxylic acid and its anhydride.

  In the hybrid resin, examples of the vinyl monomer for producing the styrene-acrylic resin unit include the following.

  Styrene monomers include styrene, o-methyl styrene, m-methyl styrene, p-methyl styrene, p-phenyl styrene, p-ethyl styrene, 2,4-dimethyl styrene, pn-butyl styrene, p-tert. -Butyl styrene, pn-hexyl styrene, pn-octyl styrene, pn-nonyl styrene, pn-decyl styrene, pn-dodecyl styrene, p-methoxy styrene, p-chloro styrene, 3 Styrene such as 1,4-dichlorostyrene, m-nitrostyrene, o-nitrostyrene, p-nitrostyrene and derivatives thereof.

  Examples of acrylic monomers include acrylic acid, methyl acrylate, ethyl acrylate, propyl acrylate, acrylic acid-n-butyl, acrylic acid isobutyl, acrylic acid-n-octyl, acrylic acid dodecyl, acrylic acid-2- Acrylic acid and acrylic esters such as ethylhexyl, stearyl acrylate, 2-chloroethyl acrylate, phenyl acrylate, methacrylic acid, methyl methacrylate, ethyl methacrylate, propyl methacrylate, -n-butyl methacrylate, methacrylic acid Such as isobutyl acid, n-octyl methacrylate, dodecyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, phenyl methacrylate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate And α- methylene aliphatic monocarboxylic acids and esters thereof, acrylonitrile, methacrylonitrile, and the like such as acrylic acid or methacrylic acid derivatives of acrylamide.

  Furthermore, as a monomer of styrene-acrylic resin, acrylic acid or methacrylic acid esters such as 2-hydroxylethyl acrylate, 2-hydroxylethyl methacrylate, 2-hydroxylpropyl methacrylate, 4- (1-hydroxy-1-methylbutyl) Examples thereof include monomers having a hydroxyl group such as styrene and 4- (1-hydroxy-1-methylhexyl) styrene.

  In the styrene-acrylic resin unit, various monomers capable of vinyl polymerization can be used in combination as required. Such monomers include ethylene unsaturated monoolefins such as ethylene, propylene, butylene and isobutylene; unsaturated polyenes such as butadiene and isoprene; halogenated compounds such as vinyl chloride, vinylidene chloride, vinyl bromide and vinyl fluoride. Vinyls; vinyl esters such as vinyl acetate, vinyl propionate and vinyl benzoate; vinyl ethers such as vinyl methyl ether, vinyl ethyl ether and vinyl isobutyl ether: vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone and methyl isopropenyl ketone N-vinyl pyrrole, N-vinyl carbazole, N-vinyl indole, N-vinyl compounds such as N-vinyl pyrrolidone; vinyl naphthalenes; maleic acid, citraconic acid, itaconic acid, a Unsaturated dibasic acids such as kenyl succinic acid, fumaric acid and mesaconic acid; unsaturated dibasic acid anhydrides such as maleic anhydride, citraconic anhydride, itaconic anhydride, alkenyl succinic anhydride; methyl half maleate Esters, ethyl maleate half ester, butyl maleate half ester, citraconic acid methyl half ester, citraconic acid ethyl half ester, citraconic acid butyl half ester, itaconic acid methyl half ester, alkenyl succinic acid methyl half ester, fumarate methyl half ester Unsaturated basic acid esters such as mesaconic acid methyl half ester; Unsaturated basic acid esters such as dimethylmaleic acid and dimethylfumaric acid; α, β-unsaturated such as acrylic acid, methacrylic acid, crotonic acid and cinnamic acid Acid An anhydride; an anhydride of the α, β-unsaturated acid and a lower fatty acid; and monomers having a carboxyl group such as alkenylmalonic acid, alkenylglutaric acid, alkenyladipic acid, acid anhydrides and monoesters thereof. It is done.

  The styrene-acrylic resin component may be a polymer cross-linked with a cross-linkable monomer as exemplified below if necessary. Crosslinkable monomers are linked via, for example, aromatic divinyl compounds, diacrylate compounds linked by alkyl chains, diacrylate compounds linked by alkyl chains containing ether bonds, aromatic groups and ether bonds. Examples include diacrylate compounds, polyester-type diacrylates, and polyfunctional crosslinking agents.

  Examples of the aromatic divinyl compound include divinylbenzene and divinylnaphthalene.

  Examples of diacrylate compounds linked by an alkyl chain include ethylene glycol diacrylate, 1,3-butylene glycol diacrylate, 1,4-butanediol diacrylate, 1,5-pentanediol diacrylate, 1,6- Examples include hexanediol diacrylate, neopentyl glycol diacrylate, and those obtained by replacing the acrylate of the above compound with methacrylate.

  Examples of diacrylate compounds linked by an alkyl chain containing an ether bond include diethylene glycol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, polyethylene glycol # 400 diacrylate, polyethylene glycol # 600 diacrylate, and dipropylene. Examples include glycol diacrylate and those obtained by replacing acrylate of the above compound with methacrylate.

  Examples of diacrylate compounds linked by a chain containing an aromatic group and an ether bond include polyoxyethylene (2) -2,2-bis (4-hydroxyphenyl) propane diacrylate, polyoxyethylene (4)- Examples include 2,2-bis (4-hydroxyphenyl) propane diacrylate, and those obtained by replacing the acrylate of the above compound with methacrylate.

  Examples of polyester diacrylates include trade name MANDA (Nippon Kayaku).

  Examples of the polyfunctional crosslinking agent include pentaerythritol triacrylate, trimethylol ethane triacrylate, trimethylol propane triacrylate, tetramethylol methane tetraacrylate, oligoester acrylate, and those obtained by replacing the acrylate of the above compounds with methacrylate; And allyl cyanurate and triallyl trimellitate.

  These crosslinkable monomers can be used in an amount of 0.01 to 10% by mass (more preferably 0.03 to 5% by mass) with respect to 100% by mass of other monomer components. Among these cross-linkable monomers, those which are preferably used from the viewpoint of fixability and offset resistance are aromatic divinyl compounds (particularly divinylbenzene) and divalent groups connected by a chain containing an aromatic group and an ether bond. Examples include acrylate compounds.

  Moreover, when obtaining the said styrene-acrylic-type resin unit, the following polymerization initiators can be used. Examples of such a polymerization initiator include 2,2′-azobisisobutyronitrile, 2,2′-azobis (4-methoxy-2,4-dimethylvaleronitrile), 2,2′-azobis (2 , 4-dimethylvaleronitrile), 2,2′-azobis (2-methylbutyronitrile), dimethyl-2,2′-azobisisobutyrate, 1,1′-azobis (1-cyclohexanecarbonitrile), 2-carbamoylazoisobutyronitrile, 2,2′-azobis (2,4,4-trimethylpentane), 2-phenylazo-2,4-dimethyl-4-methoxyvaleronitrile, 2,2′-azobis ( 2-methylpropane), methylethylketone peroxide, acetylacetone peroxide, ketone peroxide such as cyclohexanone peroxide 2,2-bis (t-butylperoxy) butane, t-butyl hydroperoxide, cumene hydroperoxide, 1,1,3,3-tetramethylbutyl hydroperoxide, di-t-butyl peroxide, t-Butylcumyl peroxide, dicumyl peroxide, α, α′-bis (t-butylperoxyisopropyl) benzene, isobutyl peroxide, octanoyl peroxide, decanoyl peroxide, lauroyl peroxide, 3,5,5 5-trimethylhexanoyl peroxide, benzoyl peroxide, m-trioyl peroxide, diisopropyl peroxydicarbonate, di-2-ethylhexyl peroxydicarbonate, di-n-propyl peroxydicarbonate, di-2- D Xylethylperoxycarbonate, dimethoxyisopropylperoxydicarbonate, di (3-methyl-3-methoxybutyl) peroxycarbonate, acetylcyclohexylsulfonyl peroxide, t-butylperoxyacetate, t-butylperoxyisobutyrate, t-butylperoxyneodecanoate, t-butylperoxy-2-ethylhexanoate, t-butylperoxylaurate, t-butylperoxybenzoate, t-butylperoxyisopropylcarbonate, di-t -Butyl peroxyisophthalate, t-butyl peroxyallyl carbonate, t-amyl peroxy-2-ethyl hexanoate, di-t-butyl peroxy hexahydroterephthalate, di-t-butyl peroxya Rate, and the like.

  The hybrid resin is a resin in which a polyester resin unit and a styrene-acrylic resin unit are directly or indirectly chemically bonded, and the above-mentioned polyester resin component, styrene-acrylic resin component, and these resin components It is comprised from the monomer component which can react with both. Examples of monomers that can react with the styrene-acrylic resin unit among the monomers constituting the polyester resin unit include unsaturated dicarboxylic acids such as fumaric acid, maleic acid, citraconic acid, and itaconic acid, or anhydrides thereof.

  Among the monomers constituting the styrene-acrylic resin unit, those capable of reacting with the polyester resin unit include those having a carboxyl group or a hydroxyl group, and acrylic acid or methacrylic acid esters.

  As a method for obtaining a hybrid resin, a polymer containing a monomer component capable of reacting with each of the above-described polyester resin and styrene-acrylic resin is present, and either or both of the resins are polymerized. The method obtained by this is preferable.

  In order to satisfy the effects of the present invention, the polyester resin component is preferably contained in the hybrid resin component in an amount of 50 parts by mass or more, more preferably 70 parts by mass or more.

  The polyester resin and hybrid resin used in the present invention contain a resin cross-linked with a trivalent or higher polyvalent carboxylic acid or anhydride and / or a trivalent or higher polyhydric alcohol. This is preferable for achieving both high-temperature offset resistance.

  Examples of the trivalent or higher polyvalent carboxylic acid or anhydride thereof include 1,2,4-benzenetricarboxylic acid, 1,2,4-cyclohexanetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid, pyromellitic acid, and These acid anhydrides or lower alkyl esters are mentioned, and examples of the trihydric or higher polyhydric alcohol include 1,2,3-propanetriol, trimethylolpropane, hexanetriol, pentaerythritol, etc. Is 1,2,4-benzenetricarboxylic acid and its anhydride.

  In the present invention, it is preferable to use a mixture of two or more polyester resins or hybrid resins having different softening points in order to expand the fixing region.

  In the present invention, it is preferable to use a mixture of two or more resins containing polyester units having different softening points in order to enlarge the fixing region. Specifically, it is preferable to use a mixture of resins having softening points of 80 ° C. to 120 ° C. and 120 to 160 ° C.

  The binder resin used in the present invention preferably has a glass transition point of 45 ° C to 65 ° C. In this range, it is preferable from the viewpoint of achieving both low-temperature fixability and storage stability.

  The acid value of the binder resin is preferably 1 to 50 mgKOH / g. When it is in this range, it is preferable in terms of both good charging characteristics and environmental stability.

  As the magnetic material used in the toner of the present invention, a conventionally known magnetic material is used. Examples of magnetic materials contained in the magnetic toner include iron oxides such as magnetite, maghemite, and ferrite, and iron oxides including other metal oxides; metals such as Fe, Co, Ni, or these metals and Al, Co, Cu , Pb, Mg, Ni, Sn, Zn, Sb, Be, Bi, Cd, Ca, Mn, alloys with metals such as Se, Ti, W, and V; and mixtures thereof.

Conventionally, as magnetic materials, triiron tetroxide (Fe ₃ O ₄ ), iron sesquioxide (γ-Fe ₂ O ₃ ), zinc oxide (ZnFe ₂ O ₄ ), iron yttrium oxide (Y ₃ Fe ₅ O _12). ), Iron cadmium oxide (CdFe ₂ O ₄ ), iron gadolinium oxide (Gd ₃ Fe ₅ O ₁₂ ), iron oxide copper (CuFe ₂ O ₄ ), lead iron oxide (PbFe ₁₂ O ₁₉ ), iron oxide nickel (NiFe ₂₎ O ₄ ), iron neodymium (NdFe ₂ O ₃ ), iron barium oxide (BaFe ₁₂ O ₁₉ ), iron magnesium oxide (MgFe ₂ O ₄ ), iron manganese oxide (MnFe ₂ O ₄ ), iron lanthanum oxide (LaFeO ₃₎ ), Iron powder (Fe), cobalt powder (Co), nickel powder (Ni), etc. are known. In the present invention, at least magnetic iron oxide is included as the magnetic material described above. Is, it is possible to select and use any one or two or more as necessary.

The magnetic properties of these magnetic materials when 795.8 kA / m (10 k Oersted) is applied include a coercive force of 1.5 kA / m to 12 kA / m, a saturation magnetization of 50 to 200 Am ² / kg (preferably 50 to 100 Am ^2). / Kg) and a residual magnetization of ² to 20 Am ² / kg is preferable. The magnetic properties of the magnetic material can be measured using a vibration type magnetometer such as VSM P-1-10 (manufactured by Toei Kogyo Co., Ltd.) under the conditions of 25 ° C. and an external magnetic field of 769 kA / m.

  In the magnetic toner of the present invention, the magnetic material is preferably magnetic iron oxide, and examples thereof include fine powders of triiron tetroxide and γ-iron sesquioxide. Further, the magnetic iron oxide, when contained in the toner particles in an amount of 20 to 150 parts by mass with respect to 100 parts by mass of the binder resin, exhibits good magnetism to prevent toner scattering while maintaining fluidity, and sufficient It is preferable for developing coloring power.

  In the present invention, the colorant may be appropriately hydrophobized using an appropriate surface hydrophobizing agent according to the initial physical properties of the toner, the production conditions of the toner particles, and the like.

  In the present invention, the number average particle diameter of the magnetic material is 0.1 to 0.3 μm. If the thickness is less than 0.1 μm, the magnetic material itself is reddish, and the color of the toner also increases redness, and the dispersibility in the resin deteriorates, resulting in a decrease in developability due to durability and separation. It becomes easy to cause the latent image carrier to be scraped by the magnetic material. On the other hand, if it exceeds 0.3 μm, the coloring power of the toner is lowered, and an attempt to obtain a high-quality image leads to an increase in toner consumption.

  In the present invention, it is preferable that a different metal such as silicon, zinc or titanium is contained inside and / or on the surface of the magnetic material. This is because the magnetic agglomeration during melt kneading can be further reduced by the interaction of the alkylcarboxylic acid with the tin compound, and the dispersibility of the magnetic substance in the toner can be improved.

  In the present invention, other colorants may be contained as required. As the colorant, carbon black and other conventionally known pigments and dyes can be used alone or in combination.

  In the present invention, other additives may be added to the toner particles as necessary. As such other additives, various additives conventionally known to be added to the inside of toner particles can be used, and examples thereof include a release agent and a charge control agent.

  Preferred examples of the release agent include aliphatic hydrocarbon waxes such as low molecular weight polyethylene, low molecular weight polypropylene, microcrystalline wax, and paraffin wax; oxides of aliphatic hydrocarbon waxes such as oxidized polyethylene wax or the like. Block copolymers of these: waxes based on fatty acid esters such as carnauba wax, sazol wax, and montanic acid ester wax; deoxidized part or all of fatty acid esters such as deoxidized carnauba wax Saturated fatty acids such as palmitic acid, stearic acid, and montanic acid; unsaturated fatty acids such as brassic acid, eleostearic acid, and valinalic acid; stearyl alcohol, aralkyl alcohol, behenyl alcohol, carnauvyl alcohol, and seryl alcohol Saturated alcohols such as melyl alcohol, polyhydric alcohols such as sorbitol; Fatty acid amides such as linoleic acid amide, oleic acid amide, lauric acid amide; Methylene bis stearic acid amide, ethylene biscapric acid amide, ethylene bis Saturated fatty acid bisamides such as lauric acid amide and hexamethylene bis stearic acid amide; ethylene bis oleic acid amide, hexamethylene bis oleic acid amide, N, N′-dioleyl adipic acid amide, N, N′-dioleyl sebacic acid Unsaturated fatty acid amides such as amides; Aromatic bisamides such as m-xylene bis-stearic acid amide and N, N′-distearylisophthalic acid amide; Calcium stearate, calcium laurate, zinc stearate, magnesium stearate, etc. Aliphatic metal salts (generally referred to as metal soaps); waxes grafted with aliphatic hydrocarbon waxes using vinyl monomers such as styrene and acrylic acid; fatty acids such as behenic acid monoglycerides Examples include partially esterified products of monohydric alcohols; methyl ester compounds having a hydroxyl group obtained by hydrogenation of vegetable oils and fats; long-chain alkyl alcohols or long-chain alkyl carboxylic acids having 12 or more carbon atoms; and the like.

  Examples of the release agent particularly preferably used in the present invention include aliphatic hydrocarbon waxes. As such an aliphatic hydrocarbon wax, for example, a low molecular weight alkylene polymer obtained by radical polymerization of alkylene at a high pressure or a Ziegler catalyst at a low pressure; a high molecular weight alkylene polymer is thermally decomposed. Alkylene polymers obtained; synthetic hydrocarbon waxes obtained from the distillation residue of hydrocarbons obtained by the age method from synthesis gas containing carbon monoxide and hydrogen, and synthetic hydrocarbon waxes obtained by hydrogenating them; these aliphatics And hydrocarbon waxes separated by press sweating, solvent method, vacuum distillation and fractional crystallization.

  Examples of the hydrocarbon as the matrix of the aliphatic hydrocarbon wax include those synthesized by the reaction of carbon monoxide and hydrogen using a metal oxide catalyst (often a multi-component system of two or more types) (for example, Hydrocarbon compounds synthesized by the Gintor method and Hydrocol method (using a fluidized catalyst bed); Up to several hundred carbon atoms can be obtained by the Age method (using an identified catalyst bed) in which many waxy hydrocarbons are obtained Hydrocarbons; hydrocarbons obtained by polymerizing alkylene such as ethylene with a Ziegler catalyst. Among such hydrocarbons, in the present invention, it is preferable that the hydrocarbon is a linear hydrocarbon having a small number of branches and a long saturation, and particularly a hydrocarbon synthesized by a method not based on polymerization of alkylene has a molecular weight distribution. Is also preferable.

  In the present invention, the release agent is contained in the toner particles so that when the toner particles containing the release agent are measured with a differential scanning calorimeter, an endothermic main peak appears in the region of 70 to 140 ° C. in the obtained DSC curve. It is preferable from the viewpoint of low-temperature fixability and high-temperature offset resistance of the toner.

  The toner of the present invention preferably contains a release agent having a melting point of 70 to 120 ° C. as defined by the endothermic peak temperature at the time of temperature rise by differential scanning calorimeter (DSC) measurement. The melting point of the release agent is more preferably 80 to 115 ° C, still more preferably 90 to 110 ° C. When the melting point is less than 70 ° C., the toner viscosity is lowered and the releasing effect is lowered, and the developing member / cleaning member is contaminated due to durability, and when the melting point exceeds 120 ° C., the required low temperature fixability Is difficult to obtain.

  Moreover, regarding the molecular weight distribution measured by gel permeation chromatography (GPC) of the release agent, the ratio (Mw / Mn) of the number average molecular weight (Mn) to the weight average molecular weight (Mw) is 1.2 to 2.0. It is preferable that When Mw / Mn is less than 1.2, the dispersibility in the binder resin is lowered and released in the toner, and the developing member and the cleaning member are contaminated. When Mw / Mn exceeds 2.0, it is difficult to obtain the fixability required because the rapid meltability is lowered.

  The release agent is preferably added in an amount of 1 to 30 parts by mass with respect to 100 parts by mass of the binder resin. When the amount is less than 1 part by mass, the desired release effect cannot be obtained sufficiently. When the amount exceeds 30 parts by mass, the dispersion in the toner is poor, and the toner adheres to the photoreceptor, and the developing member / cleaning. There is a tendency that the surface of the member is contaminated, and the toner image is deteriorated.

  In this invention, it is preferable that the timing which adds this mold release agent is the time of binder resin manufacture. Since the effect as a compatibilizer of the alkylcarboxylic acid component used as a catalyst at the time of resin production is more easily exhibited, the low melting point wax can be more uniformly dispersed. In addition, since the release agent is dispersed in advance, the effect of dispersing the magnetic material at the time of toner melt-kneading is increased, which is preferable.

  The endothermic peak temperature can be measured according to ASTM D3418-82 using a highly accurate internal heat input compensation type differential scanning calorimeter, for example, DSC-7 manufactured by PerkinElmer, Inc. The appearing temperature can be adjusted by using a release agent in which the melting point, glass transition point, polymerization degree, and the like are appropriately adjusted. The DSC-7 is applied to the measurement of the temperature indicating the thermal physical properties of the toner particles and the toner particle material such as the glass transition point of the binder resin, the softening point, and the melting point of the wax in addition to the peak temperature. Can do.

  The release agent preferably contains 2 to 15 parts by mass per 100 parts by mass of the binder resin in the toner particles from the viewpoint of fixability and charging characteristics.

  In the toner of the present invention, a charge control agent can be used to stabilize the chargeability. The charge control agent varies depending on the type of charge control agent and the physical properties of other toner particle constituent materials, but generally 0.1 to 10 parts by mass per 100 parts by mass of the binder resin is preferably contained in the toner particles. More preferably, 0.1 to 5 parts by mass are contained. As such charge control agents, there are known ones for controlling the toner to be negatively charged and those for controlling the toner to be positively charged. One or two kinds of various kinds of charge control agents are used depending on the kind and use of the toner. The above can be used.

  For controlling the toner to be negatively charged, for example, an organometallic complex and a chelate compound are effective. Examples thereof include a monoazo metal complex; an acetylacetone metal complex; a metal compound of an aromatic hydroxycarboxylic acid or an aromatic dicarboxylic acid; Is mentioned. In addition, examples of the toner that controls the toner to be negatively charged include aromatic mono- and polycarboxylic acids and metal salts and anhydrides thereof; phenol derivatives such as esters and bisphenol;

  Examples of toners that can be positively charged include, for example, modified products of nigrosine and fatty acid metal salts; quaternary ammoniums such as tributylbenzylammonium-1-hydroxy-4-naphthosulfonate and tetrabutylammonium tetrafluoroborate. Salts, and onium salts such as phosphonium salts and analogs thereof, and lake pigments thereof; triphenylmethane dyes and lake pigments thereof (including phosphotungstic acid, phosphomolybdic acid, phosphotungstic molybdic acid, Tannic acid, lauric acid, gallic acid, ferricyanic acid, ferrocyanic compound, etc.); metal salts of higher fatty acids; diorganotin oxides such as dibutyltin oxide, dioctyltin oxide, dicyclohexyltin oxide; dibutyltin borate Dioctyl tin borate, diorgano tin borate such as dicyclohexyl tin borate; and the like. In the present invention, these can be used alone or in combination. Moreover, charge control resin can also be used and can also be used together with the above-mentioned charge control agent. Among them, charge control agents such as nigrosine compounds and quaternary ammonium salts are particularly preferably used for controlling the toner to be positively charged.

  The toner of the present invention is preferably negatively charged from the viewpoint of the physical properties of the toner material. As the charge control agent, an azo-based iron complex or an aromatic oxycarboxylic acid metal compound includes a binder resin and a magnetic substance. It is preferably used from the viewpoint of dispersibility.

The toner of the present invention preferably has a dielectric loss tangent (tan δ) measured at a frequency of 100 kHz in the range of 1 × 10 ^{−3 to} 6 × 10 ⁻³ . If the dielectric loss tangent is within this range, the dispersibility of the magnetic material in the toner will be good, the fluctuation of the charging characteristics due to the environment will be suppressed, and the latent image carrier will be effectively scraped off due to the magnetic material detachment. It becomes possible to do. The dielectric loss tangent of the toner is obtained by measuring the complex dielectric constant at a frequency of 100 kHz after calibrating the frequencies of 1 kHz and 1 MHz using a 4284A Precision LCR meter (manufactured by Hewlett-Packard).

  The toner of the present invention is used by externally adding various materials according to the type of toner to the toner particles described above. Examples of the externally added material include a fluidity improver that improves the fluidity of the toner, such as inorganic fine powder, and a conductive fine powder that adjusts the chargeability of the toner, such as metal oxide fine particles. And other external additives.

  Examples of the fluidity improver include those that can improve the fluidity of the toner by external addition to the toner particles. Examples of such fluidity improvers include fluorine resin powders such as fine vinylidene fluoride powder and polytetrafluoroethylene fine powder; fine powder silica such as wet process silica and dry process silica, fine powder titanium oxide, and fine powder. Alumina; treated silica, surface treated with silane coupling agent, titanium coupling agent, silicone oil, etc., treated titanium oxide, treated alumina; and the like.

The fluidity improver preferably has a specific surface area by nitrogen adsorption measured by the BET method of 30 m ² / g or more, and more preferably 50 m ² / g or more. Although a fluidity improver changes with kinds of fluidity improver, it is preferable to mix | blend 0.01-8 mass parts with respect to 100 mass parts of toner particles, for example, and mix | blend 0.1-4 mass parts. Is more preferable.

A preferred fluidity improver is a fine powder produced by vapor phase oxidation of a silicon halogen compound, and is referred to as dry process silica or fumed silica. Such silica utilizes, for example, a thermal decomposition oxidation reaction in oxygen and hydrogen of silicon tetrachloride gas, and the basic reaction formula is as follows.
SiCl ₄ + 2H ₂ + O ₂ → SiO ₂ + 4HCl

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

  Examples of commercially available silica fine powders produced by vapor phase oxidation of silicon halogen compounds include those sold under the following trade names: AEROSIL (Nippon Aerosil Co., Ltd.) 130, 200, 300, 380, TT600, MOX170, MOX80, COK84; Ca—O—SiL (CABOT Co.) M-5, MS-7, MS-75, HS-5, EH-5; Wacker HDK N 20 (WACKER-CHEMIE GMBH) V15, N20E, T30, T40; DC Fine Silica (Dow Corning CO.); Fransol (Fransil).

  In the present invention, the silica fine powder is preferably hydrophobized. The silica fine powder is obtained by treating the silica fine powder so that the degree of hydrophobicity measured by a methanol titration test is in the range of 30 to 80 degrees. It is particularly preferable for expression. The degree of hydrophobicity is expressed as a volume-based percentage of methanol in a liquid mixture of methanol and water at the end of sedimentation of the silica fine powder by dropping methanol onto a predetermined amount of the silica fine powder stirred in water. The

  Examples of the method for hydrophobizing silica fine powder include a method of chemically treating silica fine particles with an organosilicon compound or silicone oil that reacts with silica fine powder or is physically adsorbed on silica fine particles. More preferably, it is a hydrophobic treatment with an organosilicon compound.

  Examples of the organosilicon compound include hexamethyldisilazane, trimethylsilane, trimethylchlorosilane, trimethylethoxysilane, dimethyldichlorosilane, methyltrichlorosilane, allyldimethylchlorosilane, allylphenyldichlorosilane, benzyldimethylchlorosilane, and bromomethyl. Dimethylchlorosilane, α-chloroethyltrichlorosilane, β-chloroethyltrichlorosilane, chloromethyldimethylchlorosilane, triorganosilylmercaptan, trimethylsilylmercaptan, triorganosilylacrylate, vinyldimethylacetoxysilane, dimethylethoxysilane, dimethyldimethoxysilane, Diphenyldiethoxysilane, hexamethyldisiloxane, 1,3-divirtetramethyldisiloxane, 1, Examples thereof include 3-diphenyltetramethyldisiloxane and dimethylpolysiloxane having 2 or 12 siloxane units per molecule and having a hydroxyl group bonded to Si in a terminal unit. These may be used alone or as a mixture of two or more.

  In the hydrophobization treatment of the silica fine powder, it is possible to use one or more silane coupling agents having a nitrogen atom among the organosilicon compounds. Examples of such nitrogen-containing silane coupling agents include aminopropyltrimethoxysilane, aminopropyltriethoxysilane, dimethylaminopropyltrimethoxysilane, diethylaminopropyltrimethoxysilane, dipropylaminopropyltrimethoxysilane, dibutylaminopropyltrimethoxysilane. Methoxysilane, monobutylaminopropyltrimethoxysilane, dioctylaminopropyldimethoxysilane, dibutylaminopropyldimethoxysilane, dibutylaminopropylmonomethoxysilane, dimethylaminophenyltriethoxysilane, trimethoxysilyl-γ-propylphenylamine, trimethoxysilyl -Γ-propylbenzylamine and the like.

  In the present invention, a preferable silane coupling agent is hexamethyldisilazane (HMDS).

The silicone oil preferably used in the hydrophobization treatment of the silica fine powder preferably has a viscosity at 25 ° C. of 0.5 to 10000 mm ² / s, more preferably 1 to 1000 mm ² / s. It is still more preferable that it is 10-200 mm < ² > / s. Particularly preferred silicone oils include, for example, dimethyl silicone oil, methylphenyl silicone oil, α-methylstyrene modified silicone oil, chlorophenyl silicone oil, and fluorine modified silicone oil.

  As a method for surface hydrophobization treatment of silica fine powder using silicone oil, for example, silica fine powder treated with a silane coupling agent and silicone oil are directly mixed using a mixer such as a Henschel mixer; A method in which silicone oil is sprayed onto a silica fine powder; a method in which silicone oil is dissolved or dispersed in a suitable solvent, and then the silica fine powder is added and mixed to remove the solvent.

  When the surface of the silica fine powder is hydrophobized with silicone oil, the silica fine powder is heated to 200 ° C or higher (more preferably 250 ° C or higher) in an inert gas after the silicone oil treatment to stabilize the surface coating. More preferably.

  In the present invention, it is possible to use both the silane coupling agent and the silicone oil described above for the surface hydrophobization treatment of the silica fine powder. Examples thereof include a method of treating with a silane coupling agent and then treating with silicone oil, or a method of treating a silica fine powder simultaneously with a silane coupling agent and silicone oil.

  The production method of the toner of the present invention is not particularly limited, but the binder resin, magnetic material, and, if necessary, other additives are sufficiently mixed by a mixer such as a Henschel mixer or a ball mill, By melting, kneading and kneading using a heat kneader such as an extruder to make the resins compatible with each other, cooling and solidifying the molten kneaded product, and then crushing the solidified product and classifying the crushed product A method of obtaining toner particles is preferred. The toner particles and an external additive such as a fluidity improver can be obtained by sufficiently mixing them as necessary with a mixer such as a Henschel mixer.

  In the production of the toner of the present invention, the classification can be performed at any time after the toner particles are generated. For example, the classification may be performed after mixing with an external additive. Further, an appropriate impact such as mechanical or thermal may be applied to the generated toner particles to control the particle shape of the toner particles (more specifically, spheroidization).

  In the present invention, the method of pulverizing the solidified product is preferably a method of applying a mechanical impact force. Examples of the treatment that gives mechanical impact force include a method using a mechanical pulverizer such as a pulverizer KTM manufactured by Kawasaki Heavy Industries, Ltd., a turbo mill manufactured by Turbo Industry Co., Ltd., a mechano-fusion system manufactured by Hosokawa Micron, and Nara Machinery Co., Ltd. The method of processing with apparatuses, such as a manufactured hybridization system, is mentioned. These apparatuses can be used as they are or after being appropriately improved.

  The toner of the present invention preferably has a weight average particle diameter of 3 to 9 μm from the viewpoint of image density and resolution.

  The following are commonly used devices for toner production, but are not limited to these.

  A method for measuring physical properties of the toner of the present invention is as follows. Examples described later are also based on this method.

(I) Particle size measurement of magnetic material The average particle size of the magnetic material can be measured using, for example, a laser diffraction particle size distribution meter (manufactured by Horiba, Ltd.).

(Ii) Measuring method of softening point of resin The softening point of the resin is measured by a descending flow tester according to the measuring method shown in JIS K7210. A specific measurement method is shown below.

While a 1 cm ³ sample was heated at a heating rate of 6 ° C./min using a descent flow tester (manufactured by Shimadzu Corporation), a load of 1960 N / m ² (20 kg / cm ² ) was applied by a plunger, and the diameter was 1 mm. Then, a nozzle having a length of 1 mm is pushed out, thereby drawing a plunger descending amount (flow value) -temperature curve, where the height of the S-shaped curve is h, the temperature relative to h / 2 (half of the resin is The temperature that flows out) is taken as the softening point.

(Iii) Measurement of glass transition point (Tg) and melting point of wax As a measuring device, a differential scanning calorimeter (DSC) and MDSC-2920 (manufactured by TA Instruments) are used and measured according to ASTM D3418-82.

  The measurement sample is precisely weighed in an amount of 2 to 10 mg, preferably 3 mg. This is put into an aluminum pan, and an empty aluminum pan is used as a reference, and measurement is performed at a temperature rise rate of 10 ° C./min at a temperature rise rate of 30 ° C. to 200 ° C. at normal temperature and humidity. The analysis is performed with a DSC curve in the temperature range of 30 to 200 ° C. obtained in the second temperature raising process.

  For the glass transition point (Tg), the value analyzed by the midpoint method from the obtained DSC curve is used. For the melting point of the wax, the temperature value of the endothermic main peak of the obtained DSC curve is used.

(Iv) Measurement of particle size distribution Measuring apparatus: Coulter Multisizer IIe (manufactured by Beckman Coulter)
As the electrolytic solution, 1% NaCl aqueous solution is prepared using first grade sodium chloride. For example, ISOTON R-II (manufactured by Beckman Coulter) can be used. As a measuring method, 0.1 to 5 ml of a surfactant, preferably alkylbenzenesulfonate is added as a dispersant to 100 to 150 ml of the electrolytic aqueous solution, and 2 to 20 mg of a measurement sample is further added. The electrolytic solution in which the sample is suspended is subjected to a dispersion treatment with an ultrasonic disperser for about 1 to 3 minutes, and the measurement device is used to measure the volume and number of toners of 2 μm or more using a 100 μm aperture as an aperture. Volume distribution and number distribution were calculated. Then, the weight average particle diameter (D4) and the number average particle diameter (D1) according to the present invention (respectively, the median value of each channel is a representative value for each channel) were obtained.

(V) Measurement of molecular weight distribution of wax Gel permeation chromatography (GPC) measuring apparatus: GPC-150C (Waters)
Column: GMH-HT 30 cm 2 series (manufactured by Tosoh Corporation)
Temperature: 135 ° C
Solvent: o-dichlorobenzene (0.1% ionol added)
Flow rate: 1.0 ml / min
Sample: 0.4 ml injection of 0.15% sample A molecular weight calibration curve prepared from a monodisperse polystyrene standard sample is used for calculating the molecular weight of the sample. Furthermore, it calculates by converting into polyethylene by the conversion formula derived from the Mark-Houwink viscosity formula.

(Vi) Acid Value Measurement Method In the present invention, the acid value of the binder resin can be measured according to a conventional method. For example, 2 to 10 g of a sample is weighed into a 200 to 300 ml Erlenmeyer flask, and methanol: toluene = 30. : Add about 50 ml of 70 mixed solvent to dissolve the resin. If solubility is poor, a small amount of acetone may be added. Using a mixed indicator of 0.1% bromthymol blue and phenol red, titration with a 0.1 mol / l potassium hydroxide-alcohol solution standardized in advance, from the consumption of potassium hydroxide-alcohol solution according to the following formula Find the acid value.
Acid value = KOH (ml) × n × 56.1 / sample weight (g)
(N is a factor of 0.1 mol / l KOH)

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

(Binder Resin Production Example 1-1)
A monomer for obtaining polyester and a tin compound of alkylcarboxylic acid are charged into a four-necked flask, and equipped with a decompression device, a water separation device, a nitrogen gas introduction device, a temperature measurement device, and a stirring device, and the temperature is maintained at 230 ° C. in a nitrogen atmosphere. The reaction was carried out at an elevated temperature. After completion of the reaction, the product was taken out from the container, cooled and pulverized to obtain a binder resin 1-1 having a softening point of 138 ° C. Table 6 shows the types of monomers and tin compounds used and the physical properties of the resulting resin.

(Binder Resin Production Examples 1-2 to 1-10)
In Production Example 1, the amount and type of the monomer and the alkylcarboxylic acid tin compound were changed as shown in Table 6, and the reaction was conducted while confirming the softening point. When the softening point shown in Table 5 was reached, the reaction was performed. Binder resins 1-2 to 1-10 were obtained in the same manner as in Production Example 1-1 except that the process was terminated. Table 6 shows the physical properties of the obtained binder resin.

(Binder Resin Production Example 1-11)
A monomer for obtaining a polyester unit and a tin compound of an alkyl carboxylic acid are charged into a four-necked flask and equipped with a decompression device, a water separation device, a nitrogen gas introduction device, a temperature measurement device, and a stirring device, and 130 ° C. in a nitrogen atmosphere. A mixture of a vinyl copolymer monomer and a polymerization initiator (dicumyl peroxide) shown in Table 6 was added dropwise from a dropping funnel over 4 hours while stirring at a temperature of. This was held at 130 ° C. for 3 hours, and then heated to 230 ° C. to carry out the reaction. After completion of the reaction, the product was taken out of the container and then pulverized to obtain a binder resin 1-11 having a softening point of 140 ° C. containing a polyester resin component, a vinyl polymer component and a hybrid resin. Table 6 shows the types of monomers and tin compounds used and the softening point of the resulting resin.

(Binder Resin Production Examples 1-12 to 1-14)
In the production example 1-11 of the binder resin, except that the type and amount of the monomer and the tin compound of the alkylcarboxylic acid are changed as shown in Table 6, the same method as in Production Example 1-11 is used. Binder resins 1-12 to 1-14 shown in FIG.

(Production Examples 1-a to 1-h of comparative binder resins)
Binder resin in Production Example 1-1, except that the types and amounts of monomers and alkylcarboxylic acid tin compounds were changed as shown in Table 7, using the same method as in Production Example 1-1. Comparative binder resins 1-a to 1-h shown in FIG.

<Example 1-1>
(Example of toner production)
Binder resin 1-1 60 parts by mass Binder resin 1-6 40 parts by mass Magnetic iron oxide 1-1 90 parts by mass (average particle diameter: 0.18 μm, Hc (coercivity): 11.1 kA / m , Σs (saturation magnetization): 83.3 Am ² / kg, σr (residual magnetization): 13.9 Am ² / kg, containing 0.4% by mass of Ti in the magnetic material)
T-77 (monoazo iron complex, manufactured by Hodogaya Chemical Co., Ltd.) 2 parts by mass Polypropylene wax (melting point 140 ° C.) 3 parts by mass The above mixture was melt-kneaded with a biaxial extruder heated to 120 ° C. and cooled. Was roughly crushed with a hammer mill. The coarsely pulverized product was finely pulverized with a turbo mill (manufactured by Turbo Kogyo Co., Ltd.), and the obtained finely pulverized product was classified with an air classifier to obtain magnetic toner particles.

To 100 parts by mass of the magnetic toner particles, 1.0 part by mass of hydrophobic dry silica (BET 150 m ² / g) was externally added with a Henschel mixer to obtain toner 1-1 having a weight average particle diameter of 7.4 μm.

(Evaluation of toner)
Using a commercially available Canon digital copying machine iR3300, the toner 1-1 of the present invention was used to conduct a 50,000 sheet passing durability test in a normal temperature and humidity environment (temperature 23 ° C., humidity 60%). The original used a chart with an image ratio of 5%. Image evaluation, photosensitive drum wear evaluation, and toner consumption evaluation were performed as follows. The results of each evaluation are shown in Table 10.

(Image evaluation)
1. A copy original was prepared using an original chart having an image density of 5 mm circle (1.1 density), and the reflection density was measured before and after the durability test. The image density was measured using a Macbeth densitometer (Macbeth) and using an SPI filter.
2. Sharpness of digital image Using originals containing lines and characters, images at the beginning and after the endurance test were evaluated according to the following criteria using visual observation or a magnifying glass.
A: Both character images and line images are faithfully reproduced in detail.
B: Although some disturbance or scattering has occurred in the details, it is a level at which there is no problem with visual observation.
C: It is a level where disturbance and scattering can be seen even visually.
D: Many disturbances and scattering occur, and the original is not reproduced.

(Photosensitive drum shaving)
The photosensitive drums at the beginning, endurance and after endurance of paper passing were visually observed and image defects were observed and evaluated based on the following evaluation criteria.
A: Defects are not recognized at all on the drum surface and the image.
B: In the latter half of the durability, a slight decrease in drum surface gloss is observed, but it does not appear in the image.
C: In the latter half of the durability, some scratches are observed on the drum surface, and some unevenness occurs in the image.
D: Deep scratches are observed on the drum surface in the second half of the durability, and the image is uneven.

(Toner consumption)
In the image formation test, it was obtained from the initial developing device mass and the developing device mass after outputting 2000 sheets by the following equation.
Toner consumption = {(initial developing device mass) − (2000 developing device mass after output)} / 2000
As a result, good results were obtained as shown in Table 10.

<Examples 1-2 to 1-7>
Toners 1-2 to 1-7 were obtained in the same manner as in Example 1-1 except that the resin type and blending ratio were changed as shown in Table 8 in Example 1-1.

  The obtained toners 1-2 to 1-7 were evaluated in the same manner as in Example 1-1. Table 10 shows the evaluation results.

<Example 1-8>
Toner 1-8 was obtained in the same manner as in Example 1-2 except that the magnetic material used in Example 1-2 was changed to magnetic iron oxide 1-2.

Magnetic iron oxide 1-2 has a number average particle size of 0.12 μm, Hc of 12.0 kA / m, σs of 82.2 Am ² / kg, and σr of 15.3 Am ² / kg, and 0 in the magnetic material. .4% by mass of Ti is contained.

  The obtained toner 1-8 was evaluated in the same manner as in Example 1-1. As a result, good results were obtained as shown in Table 10.

<Example 1-9>
Toner 1-9 was obtained in the same manner as in Example 1-2 except that the magnetic material used in Example 1-2 was changed to magnetic iron oxide 1-3.

Magnetic iron oxide 1-3 has a number average particle size of 0.23 μm, Hc of 10.6 kA / m, σs of 83.9 Am ² / kg, and σr of 12.6 Am ² / kg, and 0 in the magnetic material. .4% by mass of Ti is contained.

  The obtained toner 1-9 was evaluated in the same manner as in Example 1-1. As a result, good results were obtained as shown in Table 10.

<Example 1-10>
Toner 1-10 was obtained in the same manner as in Example 1-2 except that the magnetic material used in Example 1-2 was changed to magnetic iron oxide 1-4.

Magnetic iron oxide 1-4 has a number average particle size of 0.27 μm, Hc of 9.9 kA / m, σs of 84.3 Am ² / kg, and σr of 11.1 Am ² / kg, and 0 in the magnetic material. .4% by mass of Ti is contained.

  The obtained toner 1-10 was evaluated in the same manner as in Example 1-1. As a result, good results were obtained as shown in Table 10.

<Example 1-11>
Toner 1-11 was obtained in the same manner as in Example 1-6 except that the magnetic material used in Example 1-6 was changed to magnetic iron oxide 1-5.

Magnetic iron oxide 1-5 has a number average particle size of 0.23 μm, Hc of 10.2 kA / m, σs of 82.8 Am ² / kg, and σr of 12.6 Am ² / kg, and 0 in the magnetic substance. .3% by mass of Si is contained.

  The obtained toner 1-11 was evaluated in the same manner as in Example 1-1. As a result, good results were obtained as shown in Table 10.

<Example 1-12>
Toner 1-12 was obtained in the same manner as in Example 1-6 except that the magnetic material used in Example 1-6 was changed to magnetic iron oxide 1-6.

Magnetic iron oxide 1-6 has a number average particle size of 0.23 μm, Hc of 11.0 kA / m, σs of 82.1 Am ² / kg, and σr of 12.4 Am ² / kg, and 0 in the magnetic material. .3% by mass of Zn is contained.

  The obtained toner 1-12 was evaluated in the same manner as in Example 1-1. As a result, good results were obtained as shown in Table 10.

<Example 1-13>
A toner 1-13 was obtained in the same manner as in Example 1-6 except that the magnetic material used in Example 1-6 was changed to magnetic iron oxide 1-7.

Magnetic iron oxide 1-7 has a number average particle size of 0.23 μm, Hc of 10.2 kA / m, σs of 83.0 Am ² / kg, and σr of 12.8 Am ² / kg, and 0 in the magnetic substance. .3 mass% Si, 0.3 mass% Zn is contained.

  The obtained toner 1-13 was evaluated in the same manner as in Example 1-1. As a result, good results were obtained as shown in Table 10.

<Comparative Examples 1-1 to 1-4>
Comparative toners 1-1 to 1-4 were obtained in the same manner as in Example 1-1 except that the resin shown in Table 9 was changed to Example 1-9.

  The obtained comparative toners 1-1 to 1-4 were evaluated in the same manner as in Example 1-1. Table 10 shows the evaluation results.

<Comparative Example 1-5>
Comparative toner 1-5 was obtained in the same manner as in Example 1-1 except that the magnetic material used in Example 1-4 was changed to magnetic iron oxide 1-8.

Magnetic iron oxide 1-8 has a number average particle size of 0.08 μm, Hc of 15.0 kA / m, σs of 80.0 Am ² / kg, and σr of 17.3 Am ² / kg, and 0 in the magnetic material. .4% by mass of Ti is contained.

  The obtained comparative toner 1-5 was evaluated in the same manner as in Example 1-1. Table 10 shows the evaluation results.

<Comparative Example 1-6>
A comparative toner 1-6 was obtained in the same manner as in Example 1-1 except that the magnetic material used in Example 1-4 was changed to magnetic iron oxide 1-9.

Magnetic iron oxide 1-9 has a number average particle size of 0.36 μm, Hc of 9.0 kA / m, σs of 84.8 Am ² / kg, and σr of 10.9 Am ² / kg, and 0 in the magnetic substance. .4% by mass of Ti is contained.

  The obtained comparative toner 1-6 was evaluated in the same manner as in Example 1-1. Table 10 shows the evaluation results.

(1) Binder resin production example (Binder resin 2-1 production)
Trimellitic acid: 365 g
Fumaric acid: 336 g
Bisphenol A propylene oxide adduct: 1060 g
Bisphenol A ethylene oxide adduct: 966 g
The monomer is charged into a four-necked flask together with 14 g of the exemplified compound (3) in Table 1 in the presence of wax (2) as shown in Table 12, and a pressure reducing device, a water separator, a nitrogen gas introducing device, a temperature measuring device, and stirring The apparatus was attached and the reaction was performed by raising the temperature to 230 ° C. in a nitrogen atmosphere. After completion of the reaction, the reaction mixture was taken out from the container, cooled and pulverized to obtain a binder resin 2-1.

(Production of binder resins 2-2 to 2-7)
In the method for producing the binder resin 2-1, the monomer was changed to the one shown in Table 11 and the reaction was conducted while confirming the softening point, and the reaction was completed when the softening point shown in Table 11 was reached. In the same manner, binder resins 2-2 to 2-7 were obtained.

(Manufacture of binder resin 2-8)
Terephthalic acid: 400g
Trimellitic acid: 400g
Dodecenyl succinic acid: 500 g
Bisphenol A propylene oxide adduct: 700 g
Bisphenol A ethylene oxide adduct: 300 g
The polyester monomer is charged into a four-necked flask together with the exemplified compound (3) in Table 1, and equipped with a decompression device, a water separation device, a nitrogen gas introduction device, a temperature measurement device, and a stirring device, and a temperature of 130 ° C. in a nitrogen atmosphere. A mixture of vinyl polymerization monomers (styrene 472 g, 2-ethylhexyl acrylate 103 g, divinylbenzene 0.1 g) was added dropwise from the dropping funnel over 4 hours with stirring. The mixture was aged for 3 hours while maintaining the temperature at 130 ° C., and the temperature was raised to 230 ° C. to carry out the reaction. After completion of the reaction, the reaction mixture was taken out from the container, cooled and pulverized to obtain a binder resin 2-8.

(Production of binder resins 2-9, 2-10, 2-16)
In the method for producing the binder resin 2-8, the monomer and wax are changed to those shown in Table 11, and the reaction is performed while confirming the softening point. When the softening point shown in Table 11 is reached, the reaction is terminated. Except for this, binder resins 2-9, 2-10, and 2-16 were obtained in the same manner.

(Manufacture of binder resin 2-11 to 2-15)
In the method for producing the binder resin 2-1, the types and amounts of the monomer, wax and tin compound of the alkyl carboxylic acid were changed as shown in Table 11, and the reaction was conducted while confirming the softening point. Binder resins 2-11 to 15 were obtained in the same manner except that the reaction was terminated when the softening point indicated was reached.

(2) Example of production of release agent (Production of wax (1))
A wax (1) having a melting point of 115 ° C. and Mw / Mn = 1.31 by GPC measurement was obtained from polyethylene wax POLYWAX 1000 (manufactured by Toyo Petrolite Co., Ltd.) by fractional distillation.

(Manufacture of wax (2))
A wax (2) having a melting point of 100 ° C. and Mw / Mn = 1.45 as measured by GPC was obtained from coal-based Fischer-Tropsch wax C105 (manufactured by Sasol) by a fractional distillation method.

(Production of wax (3), (4))
Wax (3) having a melting point of 75 ° C. and 60 ° C. and Mw / Mn = 1.22 and 1.00 by GPC measurement from a paraffin wax HNP-10 and HNP-5 (manufactured by Nippon Seiki Co., Ltd.), respectively. (4) was obtained.

(Manufacture of wax (5))
A wax (5) having a melting point of 110 ° C. and Mw / Mn = 1.75 by GPC measurement was obtained from Unilin Wax ES844P (manufactured by Toyo Petrolite Co., Ltd.) by fractional distillation.

(Manufacture of wax (6))
A wax (6) having a melting point of 140 ° C. and Mw / Mn = 2.33 as measured by GPC was obtained from alcohol wax Umex 1210 (manufactured by Sanyo Kasei Co., Ltd.) by fractional distillation.

<Example 2-1>
(Manufacture of toner 2-1)
Binder resin 2-1 (Table 11): 105 parts by mass Magnetic body 2-3 (Table 13): 90 parts by mass 3,5-di-t-butylsalicylic acid Al compound: 0.5 parts by mass The above mixture was mixed with a Henschel mixer. Then, the mixture was melt-kneaded with a biaxial extruder heated to 120 ° C., and the cooled mixture was coarsely pulverized with a hammer mill. The coarsely pulverized product was finely pulverized with a jet mill, and the resulting fine powder was classified with an air classifier to obtain magnetic toner particles.

To 100 parts by mass of the magnetic toner particles, 1.0 part by mass of hydrophobic oil-treated silica (BET140 m ² / g) was externally added with a Henschel mixer to obtain a toner 2-1 having a weight average particle diameter of 7.0 μm.

  Next, the obtained toner 2-1 was evaluated as follows. The evaluation results are shown in Table 15.

A) Toner Durability Test Using a Canon digital copying machine iR3300, a durable image output test of 50,000 sheets of A4 size images with an image printing ratio of 20% was performed under high temperature and high humidity (30 ° C., 80%). . The change in the toner charge amount on the sleeve before and after the endurance was evaluated. Further, after the endurance image output test, image output was advanced to 200,000 sheets, and development sleeve contamination and fixing roller contamination after durability were evaluated.

(Toner charge on sleeve)
The toner carried on the sleeve is sucked and collected by a metal cylindrical tube and a cylindrical filter. At that time, the charge amount Q stored in the condenser through the metal cylindrical tube is measured, and the collected toner mass M is measured. From the measured charge amount Q and toner mass M, the charge amount per unit mass Q / M (mC / kg) was calculated and used as the toner charge amount (Q / M).

(Sleeve contamination)
After the endurance of 200,000 sheets, the toner coat on the developing sleeve was removed by a vacuum cleaner and an air blow, and sleeve contamination was evaluated visually. In addition, the effect on images was also evaluated.
A: No problem on the sleeve and the image.
B: Although there is some contamination in the non-image area on the sleeve, there is no problem on the image.
C: Although there is contamination at the upper end of the sleeve, there is no problem on the image.
D: There is obvious contamination on the sleeve, and a low density occurs at the edge of the image.
E: There is obvious contamination on the sleeve, and thin density occurs on the entire surface of the image.

(Fixing roller contamination)
After the endurance of 200,000 sheets, the amount of toner adhered by taping on the fixing roller was visually evaluated for comparison. In addition, the toner adhesion to the back side of the image during durability was also evaluated.
A: No problem on fixing roller and image.
B: There is some toner adhesion on the fixing roller, but there is no problem on the image.
C: There is toner adhesion on the fixing roller, and there is a slight amount of toner adhesion on the back side of the image in the second half of the endurance (a ratio of about one out of several hundred sheets), but there is no practical problem.
D: Toner adheres to the fixing roller, and toner adheres to the back of the image in the latter half of the durability (a ratio of about one out of several tens of sheets).
E: Toner adheres on the fixing roller, and streaky toner adheres to the back of each image in the second half of the endurance.

B) Low-temperature fixability test After obtaining an unfixed image using a Canon digital copying machine iR3300, take out the external fixing device (take out the fixing device of iR3300, attach an external drive and fixing device temperature control device, and set the process speed to 230 mm. Fixing was performed by changing the fixing temperature. The density reduction rate was measured by measuring the density before and after rubbing when the resulting image was rubbed 5 times with a load of 4900 N / m ² (50 g / cm ² ). The temperature at which the density reduction rate was 20% or less was defined as the minimum fixing temperature, and the low temperature fixing property was evaluated according to the following evaluation criteria.
A: The minimum fixing temperature is less than 145 ° C.
B: The minimum fixing temperature is less than 145 to 150 ° C.
C: The minimum fixing temperature is less than 150 to 155 ° C.
D: The minimum fixing temperature is less than 155 to 160 ° C.
E: The minimum fixing temperature is 160 ° C. or higher.

<Examples 2-2 to 2-10>
(Production of Toners 2-2 to 2-10)
Toners 2-2 to 2-10 were obtained in the same manner except that the raw material shown in Table 14 was changed in the production method of the toner 2-1. The same evaluation as in Example 2-1 was performed. The evaluation results are shown in Table 15.

<Comparative Examples 2-1 to 2-6>
(Production of Comparative Toners 2-1 to 2-6)
Comparative toners 2-1 to 2-6 were obtained in the same manner except that the raw material shown in Table 14 was changed in the production method of the toner 2-1. The same evaluation as in Example 2-1 was performed. The evaluation results are shown in Table 15.

Claims (14)

In a magnetic toner containing at least a binder resin and a magnetic substance, the main component of the binder resin is a resin having a polyester unit synthesized by using a tin compound represented by the following formula (1) as a catalyst, and the magnetic substance A magnetic toner having a number average particle size of 0.1 to 0.3 μm.
(RCOO) ₂ Sn Formula (1)
(Wherein R represents an alkyl group having 5 to 15 carbon atoms)   The magnetic toner according to claim 1, wherein the binder resin is a resin having two or more softening points.   The resin containing the polyester unit in the binder resin is a non-linear polyester crosslinked with a trivalent or higher polyvalent carboxylic acid and / or a trivalent or higher polyhydric alcohol. Or the magnetic toner according to 2.   4. The magnetic toner according to claim 1, wherein the magnetic material contains an Si element inside and / or on the surface thereof.   The magnetic toner according to claim 1, wherein the magnetic material contains Zn element inside and / or on the surface thereof.   The magnetic toner according to claim 1, wherein the magnetic material contains a Ti element inside and / or on a surface thereof.   The magnetic toner according to claim 1, wherein the toner contains an azo-based iron complex.   The magnetic toner according to claim 1, wherein the toner contains an aromatic oxycarboxylic acid metal compound.   9. The magnetic toner according to claim 1, wherein the tin compound represented by the formula (1) is tin 2-ethylhexanoate.   10. The magnetic toner according to claim 1, wherein the toner contains a release agent having a melting point of 70 to 120.degree.   The magnetic toner according to claim 10, wherein the toner contains a release agent having a melting point of 80 to 115 ° C.   The magnetic toner according to claim 10, wherein the toner contains a release agent having a melting point of 90 to 110 ° C.   The magnetic toner according to claim 10, wherein the release agent is an aliphatic hydrocarbon wax.   14. The magnetic toner according to claim 1, wherein the binder resin has an acid value of 1 to 50 mgKOH / g.