JPS63217362A - Toner for development electrostatic latent image containing basic organic acid-metal complex - Google Patents

Abstract

PURPOSE:To accelerate the rising of the extent of electrostatic charge of a toner and to make the distribution of the extent of electrostatic charge narrow and the electrostatic chargeability uniform on a developer transferring body by incorporating a specified basic org. acid-metal complex into the toner. CONSTITUTION:A toner is composed essentially of a resin (A), a colorant and a basic org. acid-metal complex (B) for providing negative charges to the resin A. The base polymer of the resin A has a mol.wt. distribution consisting of low and high mol.wt. components and carboxy groups in a polymer component corresponding to the low mol.wt. component have been cross-linked with multivalent metal ions in-between. The complex B is a compd. represented by formula I, the pref. absorbance in the wavelength range of 400-700nm is <=0.4 and a compd. represented by formula II may be concretely used. In the formula I, X is a neutral ligand, -O-Y-OCO- is bidentate ligand derived from salicylic acid or oxynaphthoic acid, M<+p> is a p-valent metal ion, each of (m) and (n) is coordination number and Z is a group of counter ions.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a developer used for developing an electrostatic latent image, and particularly to a toner for a developer used in dry electrophotography.

[Prior art]

In electrophotography, the developer that develops the electrostatic latent image on the photoreceptor to form a toner image is a component-based agent that imparts magnetism to the toner itself and eliminates the need for a carrier, or a substantially non-magnetic developer. There is a two-component developer consisting of toner and magnetic carrier. The toner is given a positive or negative charge depending on the polarity of the electrostatic charge of the latent image. The one-component developing agent allows easy management of the developer. On the other hand, two-component systems are indispensable for color electrophotography because triboelectrification can be easily controlled, developability is good, and any color can be imparted to the toner. In such developing agents, attempts have been made to reduce the particle size of toner and carrier in order to improve resolution, gradation reproducibility, and other image quality. For example, JP-A-59-222847, JP-A No. 59-2228
No. 51, No. 59-223467, etc., describe a technique for non-contact development using a combination of toner particles with a particle size of 20 μm or less and carrier particles with a particle size of 50 μm or less. However, when the particle size is reduced, the triboelectric charging properties, which have a fundamental effect on the phenomenon characteristics, deteriorate, and various problems tend to occur accordingly. In the past, insufficient chargeability of toners has often been a problem, and charge control agents that enhance chargeability and control charge polarity have been put into practical use. As charge control agents that give a positive charge, oil-soluble nigrosine dyes (Japanese Patent Publication No. 414427, etc.), quaternary ammonium salts (U.S. Pat. No. 3,565,654, JP-A-60-16),
9857, etc.), polyamine resin (Special Publication No. 132-1983),
84, etc.), and various dyes (Japanese Patent Publication No. 41-6397, 43-27596) that give a negative charge.
There are metal complex dyes (Japanese Patent Publication No. 45-26478, JP-A-57-104940, JP-A-59-78361, etc.). However, most of these charge control agents are colored,
``Since they are unsuitable for color electrophotography, a search was made for a substantially colorless one, and Japanese Patent Publication No. 55-42752, Japanese Patent Publication No. 57-104940, Japanese Patent Publication No. 57-111541,
It is introduced in No. 59-78361, No. 60-169857, etc. However, in general, charge control agents have poor compatibility with toner resins, deteriorate toner storage stability, cause uneven charging, and tend to generate fine powder during use. Not yet. On the other hand, recently, the developing characteristics in the development process have become a problem, and at the same time, the requirements for the fixing characteristics in the fixing process have become stricter. That is, (a) suppressing overheating deterioration of the copying machine; (b)
To prevent thermal deterioration of the photoreceptor, (c) To shorten the warm-up time required for the heat roller to rise to a temperature capable of fixing after the fixing device is activated, (d)
Due to demands such as minimizing the drop in temperature of the heat roller due to heat absorption into the transfer paper, making it possible to perform continuous copying many times, and (e) increasing thermal safety, There is a strong demand for reducing the power consumption of printers and making it possible to perform the fixing process while keeping the temperature of the heat roller lower. Therefore, toners are required to have good low-temperature fixability. Furthermore, the physical powder characteristics of the developer or toner itself up to and during the development and fixing process have become a problem.
In the storage environment, especially under high temperature and humidity conditions, it has a tendency to set, has resistance to disintegration against friction, abrasion, and impact that leads to pulverization or release of fine powder during development, and causes 1-ner adhesion (filming) to the photoreceptor or carrier. It is required to be able to provide high-quality images with non-releasable or non-adhesive properties, as well as offset resistance to avoid the offset phenomenon in which toner remaining on the heat roller during fixing is transferred to the subsequent transfer paper. . In response to these physical powder characteristics, the polymer into which carboxyl groups have been introduced in the toner particle resin is ionically crosslinked with polyvalent metal ions to improve blocking resistance, offset resistance, and the allowable range of fixing temperature. Proposals have been made to expand this (Japanese Patent Laid-open Nos. 57-178250, 61-110155 and 61-110156, etc.). However, the above-mentioned propensities regarding powder properties are often contradictory to each other, and furthermore, a comprehensive approach that incorporates development properties and fixing properties is required.

[Purpose of the invention]

The objects of the present invention are: (1) In terms of development characteristics, the charge amount rises quickly and /-1
，! ε de Iiii day h
The object of the present invention is to provide an electrostatic latent image developing toner that exhibits excellent charging properties, (2) has good low-temperature fixing properties and good offset resistance, and (3) has good powder characteristics. .

[Structure and effects of the invention]

The object of the present invention described above is to provide an electrostatic latent image developer in which the main component polymer of the toner particle resin has a molecular weight distribution divided into two groups, a low molecular weight component and a high molecular weight component, and at least the above-mentioned components. The polymer of the low molecular weight component contains a carboxyl group and is crosslinked via a polyvalent metal ion, and further contains a basic organic acid metal complex that imparts a negative charge to the toner particle resin in the charge order. This is accomplished by electrostatic latent image development. As the resin contained in the toner constituting the developer of the present invention, a resin obtained by reacting a carboxyl group present in a polymer component with a polyvalent metal compound is used. The resin contained in the toner has a molecular weight distribution that can be divided into at least two groups, a low molecular weight component and a component Y/T, and has a molecular weight distribution measured by gel permeation chromatography (PC). In the curve, the maximum value on the low molecular weight component side is 1 x 10' to 2 x 1
It is preferable to have at least two maximum values of 0' and 1xlO' to 2 x 10' on the high molecular weight side.By performing such a design, it is possible to fix at a lower temperature, and the elastic modulus at the time of melting is By making it possible to increase the offset resistance, the offset resistance can be further improved. At the same time, blocking resistance can also be improved. Furthermore, the high molecular weight components make the resin tough, suppressing the generation of fine powder due to collisions with carriers and photoreceptors.
Contamination of the carrier and photoreceptor surface can be prevented. When introducing a carboxy group to react with a polyvalent metal compound to form an ionic bond, it is sufficient that the carboxy group is introduced into at least the low molecular weight component. The fine powder that is produced is mainly caused by low molecular weight and relatively brittle components, so by cross-linking these low molecular weight components at least through metal ion bonds and making them tough, the generation of fine powder, which is a cause of filming, can be reduced. can be suppressed. The monomer for obtaining the polymer of the main component resin of the toner is a polymer containing at least one selected from styrene monomers, acrylic acids such as methacrylic acid, and ester monomers as an essential component. Preferably, it is a combination. Further, in order to obtain a polymer having a carboxyl group, in addition to the above monomers, a single substance selected from acrylic acid (including methacrylic acid and the like) and derivatives thereof may be copolymerized. A preferred monomer having a carboxyl group to be copolymerized is a half-ester compound having a structure obtained by an esterification reaction between an acrylic acid ester, a methacrylic acid ester, or a derivative thereof having a hydroxyl group and a dicarboxylic acid compound. If the carboxine group is introduced at a position that has little effect on the main chain structure as described above, the steric hindrance of the chemical structure will be reduced and the reaction with the polyvalent metal compound will proceed efficiently, achieving the objective of the present invention. It is possible to generate effective ionic bonds to achieve a good crosslinked structure. Examples of the styrene monomer include styrene, 0-
Methylstyrene, m-methylstyrene, p-methylstyrene, α-methylstyrene, p-ethylstyrene, 2.
3-dimethylstyrene, 2,4-dimethylstyrene, p
-n-butylstyrene, p-tert-butylstyrene, p-n-hexylstyrene, p-n-octylstyrene, p-n-nonylstyrene, p-n-decylstyrene, p-n-dodecylstyrene, p -methoxystyrene,
p-phenylstyrene, p-chlorostyrene, 3.4-
Examples include dichlorostyrene. Among these, styrene is particularly preferred. It is necessary for toner resins to have appropriate crushability during toner production, and if the content of the styrene component in the copolymer is less than 30% by weight, the crushability tends to decrease, so the content is usually 30% by weight or less. It is preferably at least 40% by weight, and the upper limit is generally 95% by weight. Examples of the acrylic ester and methacrylic ester include methyl acrylate, edyl acrylate, butyl acrylate, isobutyl acrylate, propyl acrylate, octyl acrylate, dodecyl acrylate, lauryl acrylate, and 2-ethylhexyl acrylate. ,
Acrylic esters such as stearyl acrylate, 2-chloroedyl acrylate, phenyl acrylate, and methyl α-chloroacrylate: methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, isobutyl methacrylate, methacrylic acid Examples include methacrylic acid esters such as octyl, dodecyl methacrylate, lauryl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, phenyl methacrylate, dimethylaminoethyl methacrylate, and diethylaminoethyl methacrylate. Examples of the carboxy group-containing compound forming the half-ester compound include aliphatic dicarboxylic acid compounds such as malonic acid, succinic acid, and glutaric acid, and aromatic dicarboxylic acid compounds such as phthalic acid, which are similar to acrylic acid having a hydroxyl group. A half-ester compound can be obtained by an esterification reaction with a derivative of methacrylic acid. The dicarboxylic acid compound may have a hydrogen atom substituted with a halogen group element, a lower alkyl group, an alkoxy group, or the like, or may be an acid anhydride. The hydroxyl group-containing derivatives of acrylic acid or methacrylic acid may be acrylic acid such as methacrylic acid to which 1 or 2 moles or more of alkylene oxide such as ethylene oxide or propylene oxide is added, or acrylic acid or methacrylic acid. It may also be a hydroxyalkyl ester obtained by subjecting a dihydric alcohol such as propylene glycol to an esterification reaction. A preferred half-ester compound has the following general formula (%), where L represents a divalent bonding group having 3 or more carbon atoms and having an ester bond in the molecular chain, and has a substituent. It's okay. R8 represents a hydrogen atom or a methyl group. More preferable compounds are represented by the following formulas (1) to (4). However, in the formula, Rt and R3 represent a hydrogen atom or a methyl group, m represents 1-14, and n represents 0-8. However, in the formula, R,, R5 is H or CH,, h is 1 to 14
X represents a hydrogen atom, a halogen group element, a lower alkyl group, or an alkoxy group. However, in the formula, R6 represents H or CH3, J represents an integer of 3 to 6, and k represents an integer of 0 to 8. However, in the formula, R7 represents T- (or CHs, ρ is an integer of 3 to 6, Y represents H, a halogen group element, a lower alkyl group, or an alkoxy group. Represented by the above formulas (1) to (4) Among the half ester compounds, those represented by formula [I] are preferred. Examples of the half ester compounds represented by formula [I] include succinic acid mono(meth)acryloyloxyethyl ester, succinic acid mono(meth)acryloyloxy Examples include propyl ester, glutaric acid mono(meth)acryloyloxyethyl ester, phthalic acid mono(meth)acryloyloxyethyl ester, phthalic acid mono(meth)acryloyloxypropyl ester, etc. The above-mentioned styrenic monomers, acrylic esters system monomerization,
A polymer obtained from a half ester compound obtained by an esterification reaction of an acrylic acid or methacrylic acid derivative having a methacrylic acid ester and a hydroxyl group with a nocarboxylic acid compound has a monomer unit content of , the styrenic monomer is 30 to 95% by weight
, preferably 40 to 95% by weight, 70 to 5% by weight, preferably 5 to 50% by weight of the acrylic ester monomer or methacrylic ester monomer, and 0.5% by weight of the half ester compound. It is desirable that the amount is 5 to 30% by weight, preferably 1 to 20% by weight. The content of the acrylic ester monomer or methacrylic ester monomer is more than 70% by weight,
Or the content of the half ester compound is 0.5% by weight
If the amount is less, the offset resistance during high-temperature fixing may deteriorate, and the blocking resistance and plasticizer resistance may also deteriorate. The metal elements of the polyvalent metal compound to be reacted with the carboxyl group-containing polymer contained in the toner resin of the present invention include Cu, Ag, Be, Mg, and Ca. Sr, Ba, Zn, Cd, Al1. Ti, Ge, Sn,
V, Cr, Mo. Examples include Mn, Fe, Ni, Co, Zr, Se, etc. Among these various elements, alkaline earth metals (Be,
Mg, Ca, Sr, Ba) and zinc group elements (
Zn, Cd) are preferred, particularly Mg and Zn. These polyvalent metal compounds include, for example, fluorides, chlorides, chlorates, bromides, iodides, oxides, hydroxides, sulfides, sulfites, sulfates, selenides,
Examples include lower alkyl metal compounds such as tellurides, nitrides, nitrates, phosphides, phosphinates, phosphates, carbonates, orthosilicates, acetates, oxalates, methylates, and ethylates. Among these, acetates and oxides are preferred. The amount of the polyvalent metal compound to be added varies depending on the type and amount of monomers constituting the polymer, and cannot be definitively stated, but for example, if the polymer contains the styrene monomer,
When a low molecular weight component and a high molecular weight component are constituted by the (meth)acrylic acid ester monomer and the half ester compound, the charged half ester compound 1
0.1 to 1 mole per mole is sufficient. To react this polyvalent metal compound and the polymer,
For example, the metal compound or a solution in which the metal compound is dispersed is mixed with a solution containing the polymer obtained by polymerization by a solution polymerization method, and the solvent is removed by raising the temperature for about 1 to 3 hours, Once the temperature in the system reaches approximately 150 to 180°C, maintain this temperature for over 1 hour to complete the reaction.
It's better to let them. In some cases, the metal compound may be present in the reaction system together with the solvent before starting the polymerization, and the polymer obtained by removing the solvent and the polyvalent metal monomer are rolled milled, Melt kneading may be performed using a kneader, extruder, or the like. The resin obtained by reacting the polymer and the polyvalent metal compound thus obtained has an ionic bond between the carboxy group contained in the polymer component and the metal atom, and this ionic bond causes a type of crosslinking cross-linking. is emerging. This ionic bond is a covalent bond.If the maximum value of the molecular weight distribution of low molecular weight components in the polymer molecular weight distribution of the toner main component resin is smaller than the above range, blocking resistance may deteriorate; If it is too large, the fixing performance may deteriorate. Further, if the maximum value of the molecular weight distribution of the high molecular weight component is smaller than the above range, offset resistance, durability,
High temperature and humidity resistance may deteriorate, and if it is larger than the above range, fixing performance may deteriorate. Furthermore, from the viewpoint of molecular weight distribution, the molecular weight distribution of a polymer consisting of a low molecular weight component and a high molecular weight component is weight average molecular weight (M W) / number average molecular weight 11 (M n)
It is desirable that the value of (hereinafter referred to as Mw/Mn) is 3.5 or more, preferably 4.0 to 40. In the resin having a bimodal molecular weight distribution with a low molecular weight portion and a high molecular weight portion, the content of the high molecular weight component is preferably 15% or more, particularly 15 to 50 wt q% of the entire resin. If the content of the high molecular weight component is less than 15% by weight, offset resistance and durability may decrease. The resin in the present invention may be produced by any method as long as it has the bimodal molecular weight distribution as described above. For example, a first stage polymerization is performed in which either a high molecular weight component or a low molecular weight component is first produced by polymerization, and then one of the produced polymer components is used to form the other polymer component. The other polymer component is produced by dissolving the constituent polymer in the monomer and performing the second stage polymerization, and as a result, a polymer having a bimodal molecular weight distribution can be obtained. It is presumed that the polymer obtained by the two-stage polymerization is a mixture of a low molecular weight component and a high molecular weight component uniformly at the molecular level. This two-stage polymerization can be carried out, for example, by a solution polymerization method, an @subtype method, an emulsion polymerization method, etc., and among them, a solution polymerization method is preferred. On the other hand, a polymer with a bimodal molecular weight distribution can be obtained by mixing a low molecular weight polymer component and a high molecular weight polymer component, but a polymer with a bimodal distribution obtained by mixing Since these may not be uniformly mixed at the molecular level, the polymer used in the present invention is particularly preferably obtained by the two-stage polymerization method. Furthermore, the toner resin in the present invention has a glass transition point of 50 to 80°C, a glass transition point of its low molecular weight component is 50°C or higher, preferably 55°C or higher, and a high molecular weight component of 65°C or higher. or less, preferably 60°C
The following is desirable. This is because blocking resistance can be improved by adjusting the glass transition point. Note that the glass transition point can be easily adjusted by appropriately selecting the type of monomer. Furthermore, the toner resin of the present invention may contain a monomer unit such as vinyl acetate, vinyl propionate, vinyl chloride, or ethylene in its molecular chain as long as the object of the present invention is not impaired. It may be a blend of polymers of the monomers mentioned above, or it may contain a polyester resin or an epoxy resin. Next, the basic organic acid metal complex according to the present invention has the following general formula [
A compound represented by [I] is preferable. General formula (1) In the formula, X is a neutral ligand, and the crane is its coordination number. -0-Y-OCO- is a bidentate ligand derived from salicylic acid or oxynaphthoic acid, and n is its coordination number, preferably 2 or more. In this case, Y may be the same or different. Y may have a substituent. Examples of the substituent include an alkyl group and a halogen atom. Also X
It is preferable that Y is a relatively small neutral molecule compared to Y, such as an aco molecule or an ammine molecule, but an aco molecule is practical. Further, 1+n takes an integer value determined by satisfying the number of coordination chambers of the +2-valent central metal ion M+p. The metal atoms include B, Zn, Cd, AQ, Mg, which forms a four-coordinated tetrahedral bond, and Co, which forms a planar bond. Ni, Pd, PL, Au, Cu, Cr that forms a six-coordinated octahedral bond. Co, Ni, Fe, Mn, Ti, Pd, P
t, Sn, 8-coordinated Zr. Examples include Mo, f, but preferably Co, Ni,
These are Fe, Cr and Zn. Further, Z forms a counter ion group, and when there are two or more, they may be the same or different. Examples of Z include hydrogen, an ammonium group, and an alkali metal atom, with hydrogen being preferred. Further, the basic organic acid metal complex has a wavelength of 400 to 700 nm.
It is preferable that the absorbance in the wavelength range is 0.4 or less. Next, specific examples of the complex will be shown. Exemplary Complex Compound Complex 1 Complex 2 Complex 3 Complex 4 Complex 5 Cθ Complex 6 Complex 7 Complex 8 The amount of the basic organic acid metal complex added to the toner particles depends on the type of toner resin, whether a carrier is used together, and Although the type and amount of the pigment that colors the toner varies, it is 0.1 to 20 wt%, preferably 0.1 to 20 wt%, based on the toner resin.
It is 3 to 10 wt%. By adding an appropriate amount of the complex, it is possible to compensate for the chargeability bias caused by the coloring pigment added to the toner, and to impart a predetermined chargeability to the toner particles, which is extremely convenient in terms of image quality control and device specifications. Furthermore, when the charge amount of the toner is defined as the amount of carrier used in combination with Q1, the value of Q/M can be increased, the rise of the charge amount becomes better, toner scattering is reduced due to improved efficiency, and the maximum charge of the toner is The above Q of charge rate (%) with respect to capacity
By narrowing the distribution width regarding /M, clear image quality can be achieved. The complex can be synthesized by a known method, and the methods described in JP-A-53-127726 and JP-A-57-104940 are referred to. The toner of the present invention contains a coloring agent in the above-mentioned specific resin.
The tree H book cover may contain a citrus-related material. As a coloring agent, carbon black, nigrosine dye (
C, 1, No. 50415B), Aniline Blue (C,
1, No. 50405), Calco Oil Blue (C, 1, No, a
zoic Blue3), chrome yellow (C, 1, N
o, 14090), ultramarine blue (C, [, N
o, 77103), DuPont Oil Red (C, 1, N
o, 26105), quinoline yellow (C, 1, No.
, 47005), methylene blue chloride (C,1,
No. 52015), Phthalocyanine Blue (C, 1,
No. 74160), malachite green oxalate (C, 1, No. 42000), lamp black (C,
1, No. 77266), A-Z Bengali (C, 1, N
o. 45435), mixtures thereof, and others. These colorants need to be contained in a sufficient proportion to form a visible image with sufficient concentration, and are usually about 1 to 20 parts by weight per 100 parts by weight of the resin. The magnetic material may be a metal or alloy that exhibits ferromagnetism such as ferrite, magnetite, iron, cobalt, or nickel, or a compound containing these elements, or a material that does not contain a ferromagnetic element but can be made by subjecting it to appropriate heat treatment. Mention may be made of alloys which become ferromagnetic, such as alloys of the type called Heusler alloys containing manganese and copper, such as manganese-copper-aluminum, manganese-copper-tin, or chromium dioxide. These magnetic substances are uniformly dispersed in the resin in the form of fine powder with an average particle size of 0.1 to 1 micron. And the content is toner 100
The amount per part by weight is 1 to 70 parts by weight, preferably 10 to 50 parts by weight. Examples of the property improver include fixability improvers such as polyolefins, fatty acid metal salts, fatty acid esters and fatty acid ester waxes, partially saponified fatty acid esters, higher fatty acids, higher alcohols, liquid or solid paraffin waxes, polyamide waxes, Polyhydric alcohol esters, silicone oils, aliphatic fluorocarbons, etc. can be used. In particular, the softening point ring and ball method JIS
Wax having a K2531) temperature of 60 to 150°C is preferred. Further, the toner of the present invention is preferably mixed with inorganic fine particles such as a fluidity improver. The inorganic fine particles used in the present invention include -
The secondary particle size is 5 μm to 2 μm, preferably 51 μm to 5 μm.
00 mμ particles. Further, the specific surface area measured by the BET method is preferably 20 to 500 m27 g. l・
The proportion of the inorganic powder mixed into the powder is 0.01 to 5 wt%, preferably 0.01 to 2.0 wt%.9 Examples of such inorganic fine powders include fine silica powder, alumina, titanium oxide, and barium titanate. , magnesium titanate, calcium titanate, strontium titanate, zinc oxide, silica sand, clay, snow n, diatomaceous earth, chromium oxide, cerium oxide, red iron oxide, antimony trioxide, magnesium oxide, zirconium oxide, barium sulfate, barium carbonate, carbonic acid Examples include calcium, silicon carbide, silicon nitride, etc., and silica fine powder is particularly preferred. The silica fine powder referred to herein is a fine powder having a 5i-0-Si bond, and includes both those manufactured by the silica method and the wet method. In addition to anhydrous silicon dioxide, aluminum silicate, thorium silicate, potassium silicate, magnesium silicate, zinc silicate, etc. may be used;
Those containing 5% by weight or more are preferable. Specific examples of these fine silica powders include various commercially available silicas, but those having hydrophobic groups on the surface are preferred, such as AEROSIL R-972, R-974゜R-
805, R-812 (manufactured by Aerosil), Taranox 500 (manufactured by Talco), and the like. In addition, silica fine powder treated with a silane coupling agent, a titanium coupling agent, silicone oil, silicone oil having an amine in its side chain, etc. can be used. To give an example of a preferred method for manufacturing the toner according to the present invention, first, a resin material for the binder or a toner component such as a colorant is added thereto as necessary is melt-kneaded using an extruder, and then cooled. After that, it is finely pulverized using a jet mill or the like, and then classified to obtain a toner having a desired particle size. Or, use a spray dryer etc. to melt and knead the product in a molten state using an extruder. + Parable/Niyu 1. -Dh&
"rJ4-X, -, 2- toner can be obtained with a desired particle size. The image forming method of the present invention involves preparing a developer using the above-mentioned specific toner and using it. A latent image is formed and developed using a regular electrophotographic copying machine, and the resulting toner image is electrostatically transferred onto a transfer paper, and then fixed by a heating roller fixing device whose heating roller temperature is set at a constant temperature to produce a copied image. The toner according to the present invention is particularly preferably used for fixing in which the contact time between the toner on the transfer paper and the heating roller is within 1 second, especially within 0.5 seconds.The carrier in the present invention It is preferable to use a magnetic material, such as a material that is strongly magnetized in the direction of a magnetic field, such as ferrite, magnetite, iron, nickel,
Ferromagnetic metals such as cobalt, or alloys or compounds containing these metals; alloys that do not contain ferromagnetic elements but become ferromagnetic through appropriate heat treatment, such as manganese-copper-aluminum or manganese-copper - A type of alloy called Heusler alloy such as tin or chromium dioxide can be used. Ferrite here is a general term for magnetic oxides containing iron, and is not limited to spinel-type ferrite represented by the chemical formula MO.FetOs (M is a divalent metal). Ferrite is particularly preferable for obtaining a carrier suitable for the purpose of the present invention because various magnetic properties can be obtained by changing the composition of the metal components contained in ferrite. In addition, since ferrite is an oxide, its specific gravity is smaller and lighter than metal powders such as iron powder and nickel powder, making it easier to mix and stir with toner, ensuring uniform toner concentration and amount of ILE in the band. This is suitable for realization. Moreover, ferrite has a higher electrical resistance than iron powder, nickel powder, cobalt powder, etc. (
108~101! Ωcm), it has the advantage that it can realize a carrier that can be fully used in a development method in which a high bias electric field is applied to the development gap. The ferrite has a saturation magnetization of LQ~4Qemu/g under an external magnetic field of 10,000e, and a coercive force of (1,1~
LG (preferably 10e, and resistivity 1X
It is preferable that the specific gravity is 4.0 to 5.5 and the porosity is 1.0 to 10%. In the present invention, in order to obtain a more preferable image, the toner particle size (weight average) is less than 20 μm. , especially 15~1μ
The range is preferably m. When the diameter exceeds 15 μm, high resolution and excellent gradation reproducibility cannot be obtained, but especially when the diameter is 20 μm or more, the resolution of fine characters decreases. If the thickness is less than 1 μm, fogging and toner scattering occur, making it impossible to obtain clear images. In order to improve resolution and gradation reproducibility, the carrier in the present invention is preferably spherical and has a weight average particle diameter of 2.
00 μm or less, particularly 5 μm or more and 100 μm or less is suitable. Here, if the carrier particle diameter exceeds 100 μm, particularly 200 μm, developability deteriorates and image quality deteriorates. If it is less than 5 μm, the developability, triboelectric chargeability, fluidity, etc. of the developer will be poor, and carrier scattering will likely occur. Note that the particle size or average particle size of the toner and carrier as used in the present invention means the weight average particle size, and the weight average particle size of the toner is a value measured with a Coulter Counter (manufactured by Coulter Co., Ltd.). The weight average particle size of the carrier particles is a value determined by actually measuring the particle size of each particle using a microscope. In addition, the specific resistance (resistivity) of the particles is 0.50c
After putting it in a container with a cross-sectional area of m” and tapping it,
A load of 1 kg/cm" was applied on the packed particles to a thickness of about 1 mm, and a 10" layer was placed between the load and the bottom electrode.
It is determined from the current value that flows when an electric field of ~10'V/cm is generated. The above-mentioned mixing ratio of toner and carrier is appropriately set such that the toner concentration (weight ratio of toner to developer) is 1 to 40 wt%, preferably 1.5 to 25 wt%. In the present invention, the glass transition point is measured using a differential scanning calorimeter 1 low-temperature DSCj (manufactured by Rigaku Denki Co., Ltd.) at a heating rate of 10°C/
When measured in minutes, the extension line of the baseline below the glass transition point of the DSC thermogram in the glass transition region and the rising edge of the peak are defined. hrn
15 yo ten zu n) concave pu n) wife↓ →=
6 for each) The value when the temperature at the intersection with the b-s line is defined as the glass transition point. The absorbance was measured by adding 10 parts of a basic organic acid metal complex to 100 parts of Kao (polyester) resin, adding 109 parts to 100 g of methyl ethyl ketone, and stirring with glass beads. This was applied to a thickness of 20 μm on a metal plate, peeled off, and the absorbance was measured using a Hitachi Model 330 spectrometer. Number average molecular weight Mn and weight average molecular weight M in the polymer
The value of w can be measured by various methods, and there is some variation depending on the measurement method. In this specification, Mn and MW are defined as values obtained by the following measurement method. That is, the weight average molecular weight M was determined by gel permeation chromatography (GPC) under the conditions described below.
Measure W and number average molecular weight Mn. At a temperature of 40°C, the solvent (tetrahydrofuran) was flowed at a flow rate of 1.2 mf2 per minute, and the concentration was 0.2 g/20 m
12 of the tetrahydrofuran sample solution as the sample weight
Inject mg and measure. When measuring the molecular weight of a sample, select measurement conditions in which the molecule 1 of the sample falls within a range where the logarithm of the molecular weight and the count number of a calibration curve created from several types of monodisperse polystyrene standard samples form a straight line. . The reliability of the measurement results is determined by the N
B S 706 boristyrene standard sample has a weight average molecular weight M W = 28.8X 10' number average molecular weight M
This can be confirmed by n = 13.7X 10'. Further, as the GPC column to be used, any Fukagawa column may be used as long as it satisfies the above conditions. Specifically, for example, TSK-GEL, GMH, (manufactured by Toyo Soda Co., Ltd.), etc. can be used.

【Example】

Next, examples of implementation of the present invention will be specifically explained. (Synthesis of resin) Synthesis example-1 Toluene 400a4 was placed in a 2Q separable flask, and the air in the flask was replaced with nitrogen. Thereafter, the toluene in the flask was heated to reflux. Next, 190 g of styrene, 50 g of n-butyl acrylate, and 1.0 g of benzoyl peroxide were placed in the flask, and the first stage polymerization reaction was carried out under reflux for 12 hours to produce a high molecular weight polymer component. . After 12 hours, styrene 17 was added to the flask.
A second stage polymerization reaction was carried out by dropping a mixture of 2 g of n-butyl acrylate, 50 g of monoacryloyloxyethyl succinate, 70 g of monoacryloyloxyethyl succinate, and 7 g of benzoyl peroxide over a period of 3 hours. After the dropwise addition of the mixture was completed, the second stage polymerization reaction was continued at reflux temperature for an additional hour to produce a low molecular weight polymer component. Then, add 8 ounces of zinc oxide into the flask.
g and stirred for 1 hour. Thereafter, the solvent toluene was distilled off under reduced pressure to obtain resin (1), which is a reaction product of a polymer having a carboxyl group-containing side chain and zinc oxide. The molecular weight distribution of this resin (1) was determined using H
As measured by LC-802UR, this resin (1) had a bimodal distribution of molecular weight with maxima at 4.4X 10' and 7.2X 103. Comparative Synthesis Example (1) Resin (2) was produced in the same manner as in Synthesis Example 1, except that 8 g of zinc oxide was not used. The molecular weight distribution of this resin (2) was investigated in the same manner as in Synthesis Example 1, and was found to be 3.8×10′ and 7.0×1
It had a maximum value at 03. (Preparation of developer) Example 1 (Toner) Weight: 100 parts of the resin (1) of Synthesis Example 1 and 12 parts of the exemplified complex The composition of the above formulation was mixed, melt-kneaded, crushed, classified,
50wt% toner particles with an average particle size of 12 μm (carrier) A spherical copper-tiny ferrite carrier. Particle size is 80 μm. The above 1-ner and carrier were mixed at a weight ratio of 4.96 to prepare a developer. Comparative Example (1)-1 A developer prepared in the same manner as in Example 1 except for Exemplary Complex 1. Comparative Example (1)-2 A developer in which the toner resin (1) of Example 1 was replaced with the resin (2) obtained in Comparative Synthesis Example [I]. Example 2 (Toner) Weight “Resin (
1) 100 parts exemplified complex 22 parts Treated under the same conditions as Example 1, 50 wt% average particle size 1
I got 2 μm of toner. ′ (Carrier) Zinc-based ferrite carrier. A developer having a composition of 4 wt% of the above toner and 96 wt% of key 1 was prepared. Comparative Example (2'')-1 A developer made in the same manner as in Example 2 except for Exemplified Complex 2. Comparative Example (2)-2 A developer in which the toner resin (1) of Example 2 was replaced with resin (2). Example 3 (Toner) Weight “Resin (
1) 100 parts of exemplified complex and 32 parts of developer. The conditions for preparing the toner and carrier and the formulation of the developer were the same as in Example 1. Comparative Example (3)-1 Same developer as Example 3 except for Exemplary Complex 3. Comparative Example (3)-2 Toner resin (1) of Example 3 was replaced with resin (2)
Elephant agent. Examples 4 to 6 - Development was carried out by changing the amount of Exemplary Complex 1 in the toner formulation of Example 1 as follows, and keeping the toner and carrier preparation conditions and developer formulation conditions the same as in Example 1. I got some medicine. In addition, as a series of addition amount of complex 1, Comparative Example (1")-1 and Example 1 are also listed. Complex 1 (part/resin<1) 100 parts) Comparative Example (1)-10 parts Example 4 1 part carried out Example 1 2 parts Example 5 3 parts Example 6 5 parts Using the above developer, an electrophotographic copying machine rU-Bix18
0J (manufactured by Konishiroku Photo Industry Co., Ltd.) to form and develop an electrostatic image, and conduct a photocopying test in which the resulting toner image was transferred onto transfer paper and then fixed using a heating roller fixing device to form a copy image. Fixing properties, anti-offset properties, transparency and durability were measured by the following methods, and image quality and toner scattering were observed. Show the results in Table 1. Further, the relationship between the amount of the complex added and MTF was determined based on Examples 4 to 6, and is shown in FIG. In addition, MTF is determined by reading the copied image of the 10 lines/am chart with a microdensitometer, and calculating its D wax and D
It is defined by the following formula using win. Dmax-Dmin MFT=D + *ax+ D m, inFixing property: 150.The image fixed by the fixing roller at set temperatures of 160 and 180°C was rubbed with a constant load using a rubbing tester to determine the microdensity. The residual rate of the image was measured using a tomometer, and the success or failure of fixing was determined. ○: Fixing at 150° C. Δ: 160° C. INOX: 180° C. 11 Offset resistance: The temperature of the fixing roller was changed, and it was visually determined based on the state of toner transfer to the white background area of the transfer paper. ○: Occurs at 250℃ or higher Δ: 230℃! X: 200℃ Durability: Printed 50,000 copies at U B 1x1800,
Evaluation was made by focusing on the toner charge amount and the variation in the rise of the charge amount. ○: No change in charge amount and rise Δ: No change in charge amount, but slight deterioration in rise ×: Deterioration in charge amount and rise. The degree of fidelity of reproduction of fine lines was visually judged. This judgment method is based on the toner charge amount distribution (Q/M
), the image quality (411 line reproducibility) changes depending on Q/
This is due to the change in M and the resulting change in image quality. Convex / Convex / M Hyakuraishi l y l rete ``△: Q /
M slightly spreads, but does not cause deterioration of image quality. Toner scattering: Based on visual judgment. As is clear from Table 1, Example 1 and Comparative Example (1)-1,
In No. 2, transparency is out of the question since carbon black is used as a coloring agent, but the Examples of the present invention all show results that are superior to the Comparative Examples. It is also more advantageous in terms of transparency than the azo organometallic compound used in Comparative Example (4). Regarding the relationship between the amount of the added complex and the MTF, the MTF of 60% when the added amount is 0 becomes saturated and improves to 80% when the added amount is around 2 parts by weight per 100 parts by weight of the toner resin.

【Effect of the invention】

By making the molecular weight distribution of toner resin a bimodal distribution and by introducing ionic crosslinking, we have proposed a solution to the problems related to the powder characteristics and fixing characteristics of toner particles, and by applying a specific charge control agent, color We were able to provide a useful means for improving development characteristics, including

[Brief Description of the Drawings] Figure 1 shows the toner resin content and MT of the complex according to the present invention.
It is a graph showing the relationship with F.

Claims (3)

[Claims] (1) In the electrostatic latent image developer, the main component polymer of the toner particle resin has a molecular weight distribution divided into two groups, a low molecular weight component and a high molecular weight component, and at least the weight of the low molecular weight component is An electrostatic latent image characterized in that the combination contains a carboxyl group and is crosslinked via a polyvalent metal ion, and further contains a basic organic acid metal complex that imparts a negative charge to the toner particle resin in the charge order. developing toner. (2) The basic organic acid metal complex has the following general formula [I]
The electrostatic latent image developing toner according to claim 1, which is a compound represented by: General formula [I] ▲Mathematical formulas, chemical formulas, tables, etc.▼ [In the formula, X is a neutral ligand, -O-Y-OCO- is a bidentate ligand derived from salicylic acid or oxynaphthoic acid,
M^+^p is a +p-valent central metal ion, m and n represent the coordination number, and m+n is an integer determined by satisfying the number of coordination loci of M^+^p. Z is a group of counter ions that neutralize the complex ions. ] (3) The basic organic acid metal complex has a wavelength of 400 to 700 nm.
3. The electrostatic latent image developing toner according to claim 1, wherein the toner has an absorbance of 0.4 or less in a wavelength range of 0.4 or less.