JPH06214425A - Electrophotographic toner - Google Patents

Abstract

PURPOSE:To provide the electrophotographic color toner superior in hues, various kinds of fastnesses, and stability against environmental conditions. CONSTITUTION:The electrophotographic toner is obtained by dyeing the particles having anionic groups in an aqueous solution of a xanthene type basic dye [C. I. Basic Violet 11]. Since the cationic parts of the dye forms salts with the anionic groups of the resin and no chlorine counter ion exists, the toner is enhanced in stability against environmental conditions, saturation, and fastness.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic toner used as a developer in an electrophotographic copying machine, a laser printer, etc., and more specifically, a color image forming process color. Regarding toner.

[0002]

2. Description of the Related Art The electrophotographic system has been widely used in copying machines, facsimiles, laser printers and the like. Furthermore, in recent years, colorization of electrophotographic systems has been promoted. A process toner, that is, a toner colored in three primary colors of subtractive color mixture of yellow, magenta and cyan is used as a color toner used for forming a color image in the electrophotographic system. The toner is generally produced by a so-called pulverization method in which a colorant, a charge control agent, a fluidity modifier, a pulverization auxiliary agent, and the like are added to a thermoplastic resin, kneaded, pulverized, and further classified. A pigment or dye is used as the colorant. When attention is paid particularly to magenta as a colorant, a quinacridone pigment is often used as a pigment. However, in the case of coloring with a pigment, the coloring material is simply dispersed in the binder resin of the toner, so that the transparency is poor. Therefore, the color reproducibility when a plurality of colors are overlapped is insufficient, and the reproduction range of the intermediate color is narrowed. Further, the influence of transparency is remarkable when an image is formed on a transparent sheet for an overhead projector. That is, due to the poor transparency of the toner layer, the projected image has a dim and murky color tone, which hinders not only the reproduction of intermediate colors but also the primary colors. The problem of transparency can be improved to some extent by reducing the particle size of the pigment particles to the wavelength of light or less, that is, submicron. However, it is difficult to grind the pigment to the submicron size, and the cost increases significantly. Further, it is difficult to uniformly disperse a pigment pulverized to a size of submicron into a resin, and as a practical matter, it exists as an aggregate aggregate in the resin to some extent, and the pulverization effect cannot be fully utilized. When a dye is used as a colorant, it is expected that a highly transparent and vivid color tone can be obtained, and therefore many proposals have been made to use the dye as a colorant for a color toner. Although many patent proposals have been made that are characterized by using a specific dye, most of them are oil-soluble dyes, or disperse dyes that are classified as disperse dyes and oil-soluble dyes are both water-insoluble dyes. , They are classified according to the usage method, and there is almost no essential difference. These water-insoluble dyes are originally dyes used for coloring resins, and since they are colored in a state of being solid-dissolved in the resin, transparent coloring is possible.

[0003]

As the water-insoluble dye, it has been proposed to use a dye classified as a methine type, a quinophthalone type, an anthraquinone type, an azo type or the like as a colorant. As an example, Japanese Patent Laid-Open No. 59-57256 discloses
C.I. known as a damine-based oil-soluble dye. I. Solve
nt Red 49 and anthrapyridone-based oil-soluble dye (for example, CI Solvent Red 52)
An electrophotographic toner that uses and as a colorant has been proposed. Since these oil-soluble dyes exist in a solid solution with the resin and do not have a particularly strong interaction with the resin, the toner resin is plasticized by the plasticizer contained in the vinyl chloride, the eraser and the like. In this case, there is a problem that the dye tends to bleed. Further, some dyes have a problem that they easily penetrate into the fixing silicone rubber roller, reduce the releasability of the roller surface, and easily cause an offset early.

[0004] For the purpose of solving the problems caused by penetration into fixing silicone rubber rollers, attempts have been made to use dyes other than oil-soluble dyes as colorants for color toners. Japanese Patent Application Laid-Open No. 62-15555 discloses that
Color electrophotographic magenta toner containing a damine-based dye (C.I. Basic Red 1)
Is proposed. The exemplified dyes are classified as basic dyes. Similarly, Japanese Patent Application Laid-Open No. 62-15556 discloses (CI Basic Violet 11),
Japanese Patent Laid-Open No. 62-15557 discloses (C.I. Basi
c Violet 10) is illustrated. In common with the above three proposals, in the text and examples, the basic dye (a salt of a cation portion, which is the main component of the dye, and a salt of chlorine ion) itself is directly melt-kneaded into the binder resin and pulverized and classified. It was described that the dye was not penetrated into the silicone roll as a result of the test using the toner. Certainly, if it is contained in the salt form as it is, it is merely dispersed in the binder resin and the dye does not diffuse in the resin, so that the bleeding of the dye is suppressed. However, since such a basic dye salt is originally water-soluble, it exhibits hygroscopicity, and there is a concern that the environmental stability of the charging characteristics of the toner may be adversely affected. Further, it is easily inferred that when water (sweat or the like) comes into contact with the obtained image, the dye elutes, leading to blurring of the image, contamination of fingers and the like. Furthermore, if the dye is simply dispersed in the resin, the coloring is the same as with the pigment, and the coloring is not transparent, and it cannot be said that the original characteristics of the dye are exhibited.

The Japanese Patent No. 59-26017 discloses an acid value of 5
-120 parts of resin to 100 parts by weight of basic dye 5-1
A color toner has been proposed in which a "colorant" obtained by mixing and heat-treating 00 parts by weight is "dispersed" in a binder resin having substantially no acid value. According to the text and examples, the cation moiety of the basic dye is present in the form of a resin acid salt in which the cation moiety of the basic dye is substituted with H + (proton) of the carboxyl group -COOH, which is measured as the acid value. It is said that when such toner is used, continuous copying property and storage stability are excellent. According to the toner manufacturing method illustrated in the text and examples, the basic dye salt and the resin are merely melt-kneaded directly in this case as well, and in reality, all the cation moieties of the basic dye are contained in the resin. It is unlikely that it forms a salt with the carboxyl residue of. Dye salts that are not involved in the formation of salts with carboxyl residues have the same problems as described above. If it forms a salt, the anion part of the basic dye (usually a halogen ion, mostly a chloride ion)
Halogen acid (hydrochloric acid, etc.) formed by H + and H + remains in the "colorant", resulting in contamination of production equipment, working environment, and copying machine (carrier, photoconductor, charger, fixing roller). It is easily inferred that problems such as deterioration of the fixed paper, deterioration of the fixed paper, and pollution of the use environment may occur.

As an example of using a dye other than the oil-soluble dye as one component of the toner, Japanese Patent Laid-Open No. 53-80234 discloses that:
There is a proposal of a toner for electrophotographic printing, which is obtained by "dispersing" a dye in a binder resin composed of a mixture of polyester resin and polystyrene resin. In particular, it is said that a cationic dye (another name for basic dye) is used as a toner for printing on acrylic fibers, and some commercial basic dyes are listed in the text. In electrophotographic printing, a toner image is formed on a cloth by using an electrophotographic method, and the dye contained in the toner is transferred and dyed onto the cloth side by steaming (steaming). Printing is performed by removing the. For the purpose of this invention, it is necessary that the dye contained in the toner is easily separated from the binder resin, and the binder resin of the toner and the dye are simply dispersed and mixed. Therefore, strong interaction such as ionic bond and covalent bond must not work between the toner binder resin and the dye. In the examples, mere melt mixing is used as a method of blending the dye with the toner. When such a toner is used for forming an image on ordinary paper, the same problems as described above exist. Due to these problems, although a dye is originally preferable to a pigment as a colorant for a color toner, a color toner which fully exhibits the characteristics of the dye as a colorant has not been obtained yet. is the current situation.

[0007]

In view of such circumstances, the present inventors have used a dye as a colorant to realize transparent and highly saturated coloring, which is a characteristic of the dye, and at the same time, have a suitability for an electrophotographic toner. As a result of earnest researches to realize a toner that is also satisfactory, the next invention was reached. That is, the present invention provides a xanthene-based basic dye "CI Basic Viol" in the form of forming a salt with a side chain of a polymer chain of a binder resin and / or an anionic group present at the terminal.
An electrophotographic toner characterized by containing a cation portion of a dye classified as "et 11" and substantially not containing a chloride ion as a counter ion. The present invention is particularly applicable to magenta toners among process color toners.
Can be preferably applied to. It is also easy to infer that red toner obtained by blending these dyes,
Black toner and the like are also included in the scope of the present invention. The content of such dye is 0.1 to 10.0 wt%, preferably 0.2
˜6.0 wt%, and more preferably 0.5 to 4.0 wt%. It is also possible to use other dyes together for adjusting the hue. In this case, it is preferable to use a basic dye or pigment. Such a dye generally has a structure of a water-soluble salt of a cation portion which is a main component of the dye and an anion which is a counter ion thereof (mostly a halogen ion mainly containing a chloride ion), that is, a structure shown in the following chemical formula 1. In addition, other commercially available products are blended with other inorganic salts (sodium chloride, sodium sulfate, etc.) for concentration adjustment.

[0008]

[Chemical 1]

In the present invention, only the cation portion of these basic dyes is contained in the toner only in the form of forming a salt with the side chain of the polymer chain and / or the anionic group present at the terminal, and the counter ion is contained. It is necessary that the anion is substantially not contained. Such anions, more essentially halogen ions, more specifically chloride ions (in the form of salts with hydrochloric acid or alkali metal ions such as sodium chloride, alkaline earth metal ions).
Is "substantially free of", more quantitatively 5 equivalents / 1000 kg or less, preferably 2 equivalents / 1000 k
g or less, more preferably 0.5 equivalent / 1000 kg or less, still more preferably 0.05 equivalent / 1000 kg
It shall mean the following. The anion is extracted from the toner with water and quantified by a method such as ion chromatography.

The present invention does not limit the kind of the binder resin at all, and vinyl resins such as styrene-acrylic acid ester copolymers, styrene-acrylonitrile copolymers, polyacrylic acid esters, polymethacrylic acid esters and the like. , Condensation resins such as polyester and polyamide
Alternatively, any known resin used as a toner such as an epoxy resin can be used. However, in the present invention, more preferable results can be obtained by combining with the polyester resin. As the polyester resin, either a saturated polyester resin or an unsaturated polyester resin can be used. The polyester resin in the present invention mainly comprises a polyvalent carboxylic acid resin and a glycol component. Examples of the polyvalent carboxylic acids used for the polyester resin include terephthalic acid, isophthalic acid, orthophthalic acid, 1,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, diphenic acid, sulfoterephthalic acid, 5- Sulfoisophthalic acid, 4-sulfophthalic acid, 4-sulfonaphthalene-2,7 dicarboxylic acid, 5 [4-sulfophenoxy]
Aromatic dicarboxylic acids such as isophthalic acid, sulfoterephthalic acid, and their metal salts, ammonium salts, p-oxybenzoic acid, p- (hydroxyethoxy)
Aromatic oxycarboxylic acids such as benzoic acid, succinic acid, adipic acid, azelaic acid, sebacic acid, aliphatic dicarboxylic acids such as dodecanedicarboxylic acid, fumaric acid, maleic acid, itaconic acid, hexahydrophthalic acid, tetrahydrophthalic acid Unsaturated aliphatic acids such as acids, and alicyclic dicarboxylic acids, and polyvalent carboxylic acids such as trimellitic acid, trimesic acid, and trivalent or higher polycarboxylic acids such as pyromellitic acid. It can be illustrated.

Examples of the polyvalent alcohols used for the polyester resin include aliphatic polyvalent alcohols, alicyclic polyvalent alcohols, aromatic polyvalent alcohols and the like.
Examples of the aliphatic polyhydric alcohols include ethylene glycol
, Propylene glycol, 1,3-propanedioe
2,3-butanediol, 1,4-butanediol
1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, diethylene glycol
, Dipropylene glycol, 2,2,4-trimethyl-1,3-pentanediol, polyethylene glycol
Examples include aliphatic diols such as propylene, polypropylene glycol and polytetramethylene glycol, triols such as trimethylolethane, trimethylolpropane, glycerin, pentaerythritol and tetraols. it can. Examples of the alicyclic polyvalent alcohols are 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, spiroglycol, hydrogenated bisphenol A,
Examples thereof include ethylene oxide adducts and propylene oxide adducts of hydrogenated bisphenol A, tricyclodecanediol, tricyclodecane dimethanol and the like.

As the aromatic polyhydric alcohols, para-xylene glycol, meta-xylene glycol, ortho-xylene glycol, 1,4-phenylene glycol, 1,
Examples thereof include ethylene oxide adduct of 4-phenylene glycol, bisphenol A, ethylene oxide adduct of bisphenol A, and propylene oxide adduct. Further, as polyester polyol, ε
Examples thereof include lactone-based polyester polyols obtained by ring-opening polymerization of lactones such as caprolactone. A monofunctional monomer may be introduced into polyester for the purpose of blocking polar groups at the ends of the polyester polymer and improving the environmental stability of toner charging characteristics. As the monofunctional monomer, benzoic acid, chlorobenzoic acid, bromobenzoic acid, parahydroxybenzoic acid, sulfobenzoic acid monoammonium salt, sulfobenzoic acid monosodium salt, cyclohexylaminocarbonylbenzoic acid,
n-dodecylaminocarbonylbenzoic acid, t-butylbutylbenzoic acid, naphthalenecarboxylic acid, 4-methylbenzoic acid, 3-methylbenzoic acid, salicylic acid, thiosalicylic acid,
Phenylacetic acid, acetic acid, propionic acid, butyric acid, isobutyric acid,
Use of monocarboxylic acids such as octanecarboxylic acid, lauric acid, stearyl acid, and lower alkyl esters thereof, or monoalcohols such as aliphatic alcohols, aromatic alcohols and alicyclic alcohols. You can

As more specific examples of the polyester resin in the present invention, (1) polyvalent carboxylic acids containing 80 mol% or more of an aromatic monomer, and ethylene glycol 0 to
Polyester resin obtained from 90 mol% and propylene glycol 100 to 10 mol%, (2) 8 aromatic monomers
Polycarboxylic acids containing 0 mol% or more, 2,3-butanediol 5-80 mol%, ethylene glycol 20-
Polyester resin obtained from 95 mol%, (3) polyvalent carboxylic acids containing 80 mol% or more of an aromatic monomer,
And C2 to C4 aliphatic glycols 70 to 95 mol
%, A polyester resin obtained from 5 to 30 mol% of a mono-and / or polyvalent alcohol having a tricyclodecane skeleton, (4) a polyvalent carboxylic acid containing 80 mol% or more of an aromatic monomer, , C2 to C4 aliphatic glycols 7
0-95 mol%, hydroxymethyltricyclodecane 5-
Polyester resin obtained from 30 mol%, (5) polyvalent carboxylic acids containing 80 mol% or more of an aromatic monomer,
And C2 to C4 aliphatic glycols 70 to 95 mol
%, A polyester resin obtained from 5 to 30 mol% of tricyclodecane dimethanol, and (6) 80% aromatic monomer.
polyvalent carboxylic acids containing more than mol%, C2 to C4 aliphatic wing vanes O licols 70 to 95 mol%, mono and / or polyvalent alcohols having cyclohexane skeleton 5 to 30
a polyester resin obtained from the following: (7) polyvalent carboxylic acids containing 80 mol% or more of an aromatic monomer, and C
A poly-form obtained from 70-95 mol% of 2-C4 aliphatic glycols and 5-30 mol% of cyclohexanediol.
Ester resin, (8) Polyvalent carboxylic acids containing 80 mol% or more of aromatic monomers, C2 to C4 aliphatic glycols 70 to 95 mol%, hydrogenated biphenol 5 to 30 mol
polyester resin obtained from 1%, (9) polyvalent carboxylic acids containing 80 mol% or more of an aromatic monomer, and C2
To C4 aliphatic glycols 70 to 95 mol% and hydrogenated bisphenol A 5 to 30 mol%, (10) mono and / or divalent or higher carboxylic acid having a naphthalene skeleton 1 to 8 aromatic monomers containing 20 mol%
Polyhydric carboxylic acids containing 0 mol% or more, and C2 to C4
Polyester resins obtained from 70 to 100 mol% of aliphatic glycols and polyhydric alcohols containing 0 to 30 mol% of alicyclic monomers, and the like.

Here, the "aromatic monomer" is preferably terephthalic acid and / or isophthalic acid. The ratio of terephthalic acid to isophthalic acid is preferably terephthalic acid content / isophthalic acid content = 90 to 40/10 to 60 [mol%], and further terephthalic acid content / isophthalic acid content = 80 to 50/20 ˜50 [mol%], and further terephthalic acid content / isophthalic acid content = 85-60
/ 15-40 [mol%] is preferable. In the present invention,
The aromatic monomer may contain trimellitic acid and / or trimesic acid and / or pyromellitic acid in an amount of 2 to 5 mol%. In the present invention, in addition to such polyvalent carboxylic acid,
Further, the use of a trivalent or higher polyalcohol is permitted, but the purpose is to broaden the molecular weight distribution of the polyester resin and not to gel the resin. The gelation of the resin makes it particularly difficult to take out the resin from the polyester polymerization apparatus, resulting in a marked decrease in productivity. In the present invention, it is necessary that there is substantially no gelation, and more specifically, the chloroform insoluble content is 0.5% by weight or less, preferably 0.25% by weight or less.

The polyester resin in the present invention preferably contains, as an aromatic monomer, 5 to 20 mol% of benzoic acid having a branched alkyl group as a substituent. As the benzoic acid having a branched alkyl group as a substituent, it is preferable to use tert-butylbenzoic acid. Among the polyester-based resins, a resin that is particularly preferably used is one in which an aromatic polyvalent carboxylic acid is used as an acid component and an aliphatic and / or alicyclic polyvalent alcohol is used as an alcohol component. The acid value of the resin in the present invention is preferably less than 5, particularly in the case of polyester resin,
The acid value is preferably 3 mg KOH / g or less, and 1 mg
KOH / g is more preferable, still 0.5 mg KO
It is preferable to adjust so as not to exceed H / g.

The glass transition point of the resin used in the present invention is preferably 40 ° C. or higher, more preferably 50 ° C. or higher,
Further, it is preferably 60 ° C. or higher, and further preferably 65 ° C. or higher. If the glass transition point is lower than this, there is a tendency to aggregate during handling or storage,
Storage stability may be a problem. The softening point of the resin used in the present invention is preferably in the range of 80 to 150 ° C. In a toner having a resin softening temperature lower than this, there is a tendency for the toner to aggregate during handling or storage, and the fluidity may be greatly deteriorated particularly during long-term storage. If the softening point is higher than this, the fixability is impaired. Further, since it is necessary to heat the fixing roll to a high temperature, the material of the fixing roll and the material of the substrate to be copied are limited.

In the present invention, it is preferable to use an anionic group-containing resin. The anionic group is a carboxyl group, a sulfonic acid group, a sulfuric acid group, a phosphoric acid group, or a salt thereof (hydrogen salt, metal salt) or the like, and preferably a carboxyl group or an alkali metal sulfonate base.
In the case of a vinyl polymer, an anionic group can be introduced by copolymerizing an anionic group-containing monomer such as acrylic acid, methacrylic acid or sodium styrenesulfonate. In the case of polyester resin, an anionic group can be introduced by copolymerizing an anionic group-containing monomer. Examples of the sulfonic acid metal group-containing compound copolymerizable with the polyester resin include sulfoterephthalic acid, 5-sulfoisophthalic acid, 4-sulfophthalic acid, 4-sulfonaphthalene-2,7dicarboxylic acid, 5
Examples thereof include metal salts such as [4-sulfophenoxy] isophthalic acid. When it is introduced at the polymer terminal, sulfobenzoic acid or the like can be used. Examples of the metal salt include salts of Li, Na, K, Mg, Ca, Cu, Fe and the like, and particularly preferable one is Na salt. When the resin is a polyester resin, 5-sodium sulfoisophthalic acid or sulfobenzoic acid is preferably used. Also, by introducing trimellitic acid at the final stage of polyester polymerization, a carboxyl group can be added to the polyester terminal. The content of these anionic groups is not particularly limited, but is generally 2
0-5000 equivalents / 1000000g, preferably 20
It is suitable to be in the range of to 1000 equivalents / 1000000 g, more preferably 50 to 200 equivalents / 1000000 g.

The method for specifically producing the electrophotographic toner of the present invention is not particularly limited, and an appropriate one can be appropriately selected and used from known toner production methods. However, in the present invention, the cation moiety of the basic dye is contained in a form that forms a salt with the anionic group present at the side chain and / or the end of the polymer chain, which is the preferred form, and is the counterion of the basic dye. As a specific method for realizing a state in which an anion is not substantially contained, (1) a method in which an anionic group-containing resin is heated to a glass transition temperature or higher in an aqueous medium in which a basic dye is dissolved and then washed. (2) A method of swelling and / or dissolving an anionic group-containing resin in a solvent in an aqueous medium in which a basic dye is dissolved, followed by washing and solvent removal. (3) A method in which a basic dye is mixed with an aqueous microdispersion of an anionic group-containing resin, the anionic group-containing resin is aggregated, and the obtained aggregate is washed. (4) A method of dyeing anionic group-containing resin particles with a dispersion-type basic dye. Etc. can be illustrated.

According to these methods, the anionic group contained in the resin is dissociated in the aqueous medium, and the cation (mainly hydrogen ion or alkali metal ion) contained as the counterion of the anionic group and the base. The cation portion of the basic dye substitutes to form a salt between the anionic group-containing resin and the cation portion of the basic dye. At the same time, the counter ion (hydrogen ion or alkali metal ion) contained in the anionic group-containing resin and the anion portion (: halogen ion) of the basic dye form a halogen acid or an inorganic salt. Since the halogen acid or the inorganic salt is water-soluble, it does not diffuse inside the resin and can be easily removed by washing with water. Thus, it is possible to obtain a resin in which the cation portion of the basic dye is contained in the resin in the form of a salt with the anionic group contained in the resin, and the anion which is the counterion of the basic dye is substantially not contained.

In the present invention, the dyeing temperature when the method of dyeing resin particles is adopted is generally within the range from the glass transition point of the resin to 150 ° C. Dyeing under pressure may be performed to increase the boiling point of water.
In the present invention, more than 4 is more than the glass transition point of the resin.
It is preferable to perform dyeing at a temperature as high as about 0 ° C. The ratio of the aqueous medium to the dispersed resin particles at the time of dyeing is not particularly limited, but in order to enhance the dyeing efficiency, the content ratio of the resin particles to the entire aqueous dispersion is 20% by weight or more, and further 25% or more. Preferably. In the present invention, the colored resin thus obtained is directly pulverized, or after being mixed with other resins, colorants, charge control agents, fluidizing agents, waxes, other additives, etc., pulverized and classified. By doing so, or when a colored resin is obtained as resin particles, the obtained particles can be directly used as a toner.

Here, the resin particles have an average particle size of 1 to 5
It means resin particles finely divided into a range of 0 μm. The method of miniaturization is not particularly limited, and an ordinary toner is used.
The resin particles obtained by the same pulverizing and classifying method as in the above production method, or emulsion polymerization method, suspension polymerization method, dispersion polymerization method, seed polymerization method and the like can be used. In the present invention, resin particles obtained by the method shown below can be preferably used. That is, it is a particle obtained by microdispersing an anionic group-containing resin in an aqueous medium, disrupting the stable state of the microdispersed particle in the medium, and incorporating the microdispersed particles. As a method of destroying the stable state of the micro-dispersed particles, the anionic group contained in the resin is released by photolysis, thermal decomposition, hydrolysis or the like, and the dissociation degree is controlled by scanning temperature or pH. Means such as the blocking of anionic groups by ions and the destruction of the electric double layer by adding an electrolyte can be used.

The anionic group-containing resin of the present invention exhibits water dispersibility. The aqueous dispersion of the anionic group-containing resin can be produced by any known method. That is, the anionic group-containing resin and the water-soluble organic compound are mixed in an amount of 50
Premix at ~ 200 ° C and add water to it,
Alternatively, it is produced by adding a mixture of an anionic group-containing resin and a water-soluble organic compound to water and stirring at 40 to 120 ° C. Alternatively, an anionic group-containing resin is added to a mixed solution of water and a water-soluble organic compound, and 40 to 100
It is also produced by a method of stirring and dispersing at ℃. Examples of water-soluble organic compounds include ethanol, butanol, isopropanol, ethyl cellosolve, butyl cellosolve,
Dioxane, tetrahydrofuran, acetone, methyl ethyl ketone, etc. can be used. These can be used as the above-mentioned water-based microdispersion. The resin particles obtained by these methods have an average particle diameter of D
In this case, the toner has excellent characteristics as a toner because it exhibits a sharp particle size distribution in which particles in the particle diameter range of 0.5D to 2.0D account for 70% by weight or more of the whole.

As described above, in the electrophotographic toner, the stability of the charging characteristics of the toner is very important, and the moisture absorption rate of the toner itself, which greatly affects the charging stability, is made as low as possible. Is desirable. In the present invention, the basic dye is present as a salt with the anionic group contained in the resin, and the water-soluble property of the dye FF material is lost. Moreover, the halogen acid or inorganic salt resulting from the anion part of the basic dye does not remain in the resin. Therefore, the problem that occurs when a basic dye is used in the prior art, that is, the hygroscopicity due to the use of a water-soluble dye as a coloring agent is significantly reduced. A resin having an anionic group introduced therein has a large hygroscopic property, and is generally considered to be unsuitable as a toner for electrophotography. Certainly, the hygroscopicity of the anionic group-containing resin used in the present invention is considerably higher than that of the resin having the same basic composition and containing no anionic group. Nevertheless, surprisingly, the moisture absorption rate of the anionic group-containing resin, which forms a salt with the cation portion of the basic dye as shown in the present invention, is at the same level as that of the resin containing no anionic group. The moisture absorption property is greatly improved due to the coloring form.

In the toner of the present invention, the content of the dye contained in each toner particle is uniform, and the distribution within the particle is also the same. This is a great difference from the toner colored by dispersing the pigment, and the toner obtained by the present invention has very uniform charging characteristics. Due to the above-mentioned effects, the toner of the present invention has a uniform and stable environment-free charging property for each particle constituting the toner, and has a rich hue of basic dye, saturation, and It has a transparent coloring property and is excellent in fastness to sublimation because the coloring part of the dye and the resin are strongly ionically bound to each other, and it can be applied to silicone rolls, erasers and vinyl chloride sheets. -It exhibits excellent characteristics such as occurrence of no dot.

[0025]

【Example】

(Synthesis of Polyester Resin) In an autoclave equipped with a thermometer and a stirrer, 93 parts by weight of dimethyl terephthalate, 93 parts by weight of dimethyl isophthalate, 8 parts by weight of trimellitic anhydride, ethylene glycol 159 parts by weight, tricyclodecane dimethanol 30 parts by weight, and tetrabutoxy titanate 0.1 parts by weight were charged and heated at 180 to 230 ° C. for 120 minutes to carry out a transesterification reaction. Then, the temperature of the reaction system was raised to 240 ° C., and the reaction was continued for 60 minutes at a system pressure of 1 to 10 mmHg to obtain a copolyester resin (A1). The composition, glass transition temperature, specific gravity, molecular weight, melt viscosity, outflow starting temperature, and softening temperature of the obtained copolyester resin (A1) are shown in Table 1. Shown in. The composition of polyester is N
MR analysis, glass transition temperature DSC, specific gravity float-sink method, molecular weight GPC, melt viscosity Shimadzu Flow Tester CFT-5
00, the temperature was 120 ° C., the load was 10 kg / cm ² , the capillary diameter was 1 mm, and the capillary length was 10 mm. The outflow start temperature and softening temperature are Shimadzu Flow Tester C.
FT-500, heating rate 3 ℃ / min, load 50kg / c
It was measured under the conditions of m ² , capillary diameter 0.5 mm, and capillary length 1.0 mm. Moisture absorption rate is 30% 95% for coarsely crushed resin powder
It is a value measured by a Cal-Fisher type moisture content meter after being left for 72 hours in an environment of RH.

Polymerization was performed in the same manner by changing the raw materials, and the following Table 1. Polyester resin (A2) to (A5) shown in
Got In an autoclave equipped with a thermometer and a stirrer,
70 parts by weight of an ethylene oxide adduct of bisphenol A, 19.6 parts by weight of maleic anhydride, and 0.2 parts by weight of hydroquinone were charged, and nitrogen gas was introduced into the reaction system to maintain an inert atmosphere. 1 part of dibutyltin oxide was added and the temperature was raised to 200 ° C. to carry out a stirring reaction, and when the acid value reached 15, the reaction was stopped, and Table 1. To obtain a polyester resin (A6). In the polyester resins (A1) to (A5) produced by the reduced pressure polymerization method, the moisture absorption rates of the polyester resins (A2) to (A5) having a sodium sulfonate group based on sodium sulfoisophthalic acid are higher than those of (A1). It has been shown to be high.
It is also found that the polyester (A6) obtained by the normal pressure method also shows a high moisture absorption rate due to the influence of the carboxyl group shown as the acid value. Table 1. Although not particularly shown in Table 1, the results of quantifying the halogen ions contained in each resin by the ion chromatograph method were below the detection limit in all cases, or around contamination.

Table 1. The abbreviations inside are shown below. TBBA: tertiary butyl benzoic acid NDC: 1,5-naphthalenedicarboxylic acid TPA: terephthalic acid IPA: isophthalic acid SIP: sodium sulfoisophthalic acid MA: maleic acid TMA: trimellitic acid EG: ethylene glycol PG: propylene glycol- CHD: cyclohexanediol TCDD: tricyclodecane dimethanol BPP: bisphenol A propylene glycol adduct (average molecular weight 400) Tg: glass transition temperature

(Production of Polyester Aqueous Dispersion) 340 parts by weight of polyester resin (A2), methyl ethyl ketone 1
50 parts by weight and 140 parts by weight of tetrahydrofuran at 80 ° C
After dissolution at 680 parts, 680 parts of water at 80 ° C. was added to obtain an aqueous microdispersion of a copolyester resin having a particle diameter of about 0.1 μm. Further, the obtained water-based microdispersion was placed in a distillation flask and distilled until the distillate temperature reached 100 ° C. After cooling, water was added to make the solid content concentration 30%. This was designated as polyester aqueous dispersion (E2). Similarly, polyester aqueous dispersions (E3) to (E5) were obtained from the polyester resins (A3) to (A5). The obtained polyester resin (A6) 100 was placed in a four-necked 10-liter separable flask equipped with a thermometer, a condenser, and a stirring blade.
0 parts by weight and 500 parts by weight of butyl cellosolve were added to 70 ° C.
It was dissolved in. Next, 0.1 normal ammonia water 300
After adding 0 part by weight to disperse it in water, it is distilled in a distillation flask until the distillate temperature reaches 100 ° C., and after cooling, water is added to add a polyester water dispersion (E) having a solid content of 30%.
6) was obtained.

(Production of Polyester Spherical Particles) Thermometer,
Polyester water dispersion (E2) 3 was placed in a 4-necked 1 liter separable flask equipped with a condenser and a stirring blade.
00 parts by weight were charged and the temperature was raised to 80 ° C. Next, 40 parts by weight of a 20% by weight aqueous solution of dimethylaminoethyl methacrylate was added over 60 minutes, and the mixture was further added for 80 minutes for 80 minutes.
Stirring was continued while the temperature was kept at ° C. The conductivity of the system is about 1m
Raised from S / cm to 25 mS / cm and processed pH from 10.8 to 6.7. From this, it was inferred that the added dimethylaminoethyl methacrylate was almost completely hydrolyzed later to form a salt of dimethylaminoethanol and methacrylic acid. The submicron-order particle size copolymer present in the polyester water-based microdispersion grows as a united particle over time, and the average particle size is 6.5 μm.
Polyester spherical particles (P2) having a particle diameter occupation ratio (number) of 95% and having a particle diameter in the range of 0.5D to 2D, where m is the diameter and D is the diameter, are obtained. The obtained polyester particles were filtered, washed with water, and then dispersed again in water to obtain a solid content concentration of 25 wt%.
Similarly, polyester spherical particles (P3) to (P6) were obtained from the polyester aqueous dispersions (E3) to (E6).

Example 1 A stainless steel beaker with a xanthene-based basic dye, Eisen Catillon Brilliant Pink CD-BH (CI Basic Violet)
t 11 (manufactured by Hodogaya Chemical Co., Ltd.) was added and mixed with 500 parts by weight of deionized water. Next, add 100 parts by weight of lump sugar lumps of polyester resin (A2),
After heating to 95 ° C. and holding for 300 minutes, it was cooled, and the supernatant and the resin block were taken out and the resin block was thoroughly washed. The supernatant was almost transparent, and the resin mass was colored in a bright magenta color. The obtained resin mass is jet mill PJM200
Magenta toner (M1) was obtained by pulverizing and classifying with [manufactured by Nippon Numatic Industry]. The same operation was performed with the polyester resin (A1), but the concentration of the supernatant hardly changed, and the coloration of the resin mass was about the degree of contamination. In the resin (A1) in which the anionic group was not particularly introduced, coloring was scarcely possible, and only the resin in which the anionic group was introduced was colored. It can be understood to be based on ionic bonding with the cation moiety, ie salt formation.

Example 2 Styrene / methacrylic acid ester copolymer resin (styrene / butyl methacrylate / methyl methacrylate / sodium styrenesulfonate = 4)
Magenta toner (M2) was similarly obtained by using 0/25/30/5 (mol ratio). The same operation was carried out with a homopolymer resin of styrene and a polymethylmethacrylate resin, but the concentration of the supernatant hardly changed, and the coloration of the resin lump was about the degree of contamination. It was shown that this coloring is based on salt formation between the anionic group contained in the resin and the cation portion of the basic dye, as in the case of using the polyester resin.

Example 3 Polyester Water Dispersion (E
2) 400 parts by weight was placed in a separable flask equipped with a stirrer and the temperature was raised to 80 ° C. with vigorous stirring. Next, Eisen Catillon Brilliant Pink CD-
50 parts by weight of a 10% by weight BH (CI Basic Violet 11, Hodogaya Chemical Co., Ltd.) aqueous solution was added dropwise over 60 minutes and then cooled. The polyester aqueous dispersion was aggregated to obtain colored beads having an average particle diameter of 80 μm. 100 parts by weight of the obtained colored beads are washed with water and then thoroughly dried,
Magenta toner (M3) was obtained by pulverizing and classifying with a jet mill PJM200 [manufactured by Nippon Numatic Industries].

(Example 4) Polyester water dispersion (E
4) 400 parts by weight was placed in a separable flask equipped with a stirrer, and the temperature was raised to 80 ° C. with vigorous stirring. Aizen Catillon Brilliant Pink CD-BH (C.
I. 250 parts by weight of a 10 wt% aqueous solution (Basic Violet 11, Hodogaya Chemical Co., Ltd.) was added dropwise over 60 minutes and then cooled. The polyester aqueous dispersion was aggregated to obtain colored beads having an average particle diameter of 77 μm. 100 parts by weight of the obtained colored beads are washed with water, thoroughly dried, melt-mixed with 400 parts by weight of the polyester resin (A1) by a roll mill, and pulverized by a jet mill PJM200 [manufactured by Nippon Numatic Industries]. Classification was performed to obtain magenta toner (M4).

(Example 5) 50 parts by weight of anionic dispersant Mignol 802 (formalin condensate of sodium naphthalenesulfonate [manufactured by Yatasha Yushi Kogyo]) was put in a glass beaker and placed in a magnetic stirrer. Stirring vigorously, Eisen, Catillon, Brilliant Pink C
D-BH (C.I. Basic Violet 11,
Hodogaya Chemical Co., Ltd.) Add 50 parts by weight of 20% by weight aqueous solution,
Stirring was continued for 10 minutes to obtain a dispersed basic dye. 400 parts by weight of 25% by weight of polyester spherical particles ai P2) in water dispersion was charged into a stainless pot of a dye tester Mini Color (manufactured by Texum Giken), and 50 parts by weight of the resulting dispersion type basic dye was mixed, and 80 After dyeing at 60 ° C for 60 minutes, cooling, washing with a suction funnel, dehydration, redispersion with water, and drying with a spray dryer, magenta toner (M
5) was obtained. Polyester spherical particles (P3) to (P6)
Similarly, magenta toners (M6) to (M9) were obtained.

(Comparative Example 1) Polyester resin (A6) 1
00 parts by weight and oil-soluble dye Rhodamin base FB (C.
I. Solvent Red 49, manufactured by BASF) 3
Part by weight is melt mixed in a roll mill and jet mill PJ
Magenta toner (M10) was obtained by pulverizing and classifying with M200 [manufactured by Nippon Numatic Industry].

(Comparative Example 2) Polyester resin (A6) 9
5 parts by weight and quinacridone-based magenta pigment (CIP
IGMENT RED 122) 5 parts by weight is pre-mixed in a ball mill and then melt-mixed in a roll mill to obtain a jet mill PJM200 [manufactured by Nippon Numatic Industries].
Magenta toner (M11) was obtained by pulverizing and classifying.

(Comparative Example 3) Polyester resin (A1) 1
00 parts by weight and Aizen Catillon Brilliant Pink CD-BH (CI Basic Violet 1
(1; Hodogaya Chemical Co., Ltd.) 4 parts by weight were melt mixed by a roll mill and pulverized and classified by a jet mill PJM200 [manufactured by Nippon Numatic Industrial Co., Ltd.] to obtain a magenta toner (M12). Similarly, polyester resins (A2) and (A6) were used to obtain magenta toners (M13) and (M14).

Comparative Example 4 400 parts by weight of a 25% by weight aqueous dispersion of polyester spherical particles (P2) was charged into a stainless steel pot of a dye tester Mini Color (manufactured by Texum Giken), and the disperse dye Sumikaron Brilliant Red E was further added.
-FBL (C.I. Disperse Red 60,
8 parts by weight (manufactured by Sumitomo Chemical Co., Ltd.) are dispersed, dyed at 90 ° C. for 60 minutes, cooled, washed with a suction funnel, dehydrated, redispersed in water, dried with a spray dryer, and magenta toner ( M15) was obtained.

(Evaluation) Table 2 shows the evaluation results of the toners obtained from the above Examples and Comparative Examples. Shown in. The evaluation was carried out by the method shown below. (Quantification of anion) The water-soluble component contained in the obtained toner was extracted into water and analyzed by ion chromatography. In the examples, it was below the detection limit or was only traces. Comparative example toner (M1
Chloride ions were mainly detected in 2) to (M14). (Hygroscopic rate) The obtained toner was allowed to stand in an environment of 30 ° C and 95% RH for 72 hours, and then the moisture rate was measured with a Cal-Fisher type moisture meter.

(Finger Contamination Property) 50 parts by weight of the obtained toner and 1000 parts by weight of a ferrite carrier F-100 (manufactured by Powder Tech Co., Ltd.) were charged in a ball mill and stirred for about 15 minutes to form a developer. did. The resulting developer was fixed on paper using an analog type copying machine having an amorphous silicon photosensitive drum so that the average film thickness was 7 μm.
The obtained test piece was rubbed 50 times with a bare hand, and the presence or absence of contamination of the finger was examined. Comparative Example Toner (M
In 12) to (M14), the finger was stained with the dye.
Further, as a result of immersing the test piece using these toners in water, the water was colored by the elution of the dye. The other toners were also immersed in water in the same manner but no elution of the dye was observed. (Image Transparency) Similarly, a gradation image was copied on a transparent film using a copying machine and observed by an over head projector for evaluation. The transparency of Comparative Toner (M11) using a pigment was poor. Similarly, in Comparative Examples Toners (M12) to (M14) in which the basic dye was directly kneaded, the transparency was also poor. That is, it can be understood that when the basic dye is directly mixed in the resin, the dye is only dispersed in the resin in the form of particles and cannot be said to be “dyed”.

(Continuous Copying Property) Further, 10,000 copies are continuously made by using the same copying machine to change the image quality and to fix the fixing roll.
Were observed for contamination. In each of the toners (M1) to (M9) obtained in the examples, there was no clear difference between the initial image and the copied image after copying 10,000 sheets, and clear and high-definition image transfer was possible. Further, the toner scattering in the copying machine was also slight, and the fixing roll and the like were not contaminated at all. In the toners (M11) to (M14) of the comparative example, fog and blurring occurred as the number of copies increased. When the toners (M10) and (M15) of Comparative Examples were used, the fixing roll was stained reddish purple.

(Comparative Examples 5 to 11) Polyester spherical particles (P2) were used, and a dye was used as rhodamine 6GCP (C.I.
Magenta Toner (M16) was obtained in the same manner as in Example 5 except that Basic Red 1 (manufactured by BASF) was changed. Similarly, the dye was replaced with fuchsin (CI Bas).
ic Red 9 (manufactured by Nacalai Tesque)), methyl violet (CI Basic Violet 1 [manufactured by Nacalai Tesque]), crystal violet (C.I.
I. Basic Violet 3 [manufactured by Nacalai Tesque]), Eisen Catillon Red 7BNH (C.
I. Basic Violet 27 [Hodogaya Chemical]), Eisen, Catillon, Brilliant, Red 3
BPH (CI Basic Violet 15 [Hodogaya Kagaku]), Eisen Catillon Brilliant Pink BH (CI Basic Red 36 [Hodogaya Kagaku]) Magenta Tona- (M17)-(M)
22) got. (Lightfastness) A solid image of 6 cm × 6 cm was formed with the toner (M5), and the chromaticity coordinates were measured with a colorimeter CR-210 [manufactured by Minolta]. Further, an ultraviolet exposure test was carried out for 20 hours using an ultraviolet fade meter (63 ° C.), and the color difference ΔΕ from the initial chromaticity coordinates was obtained. Toner (M
Also in 17) to (M22), the light fastness was evaluated.
The results are shown in Table 3. Shown in. It can be seen that the basic dye of the present invention exhibits good light fastness as compared with other basic dyes.

[0043]

As described above, the toner according to the present invention sufficiently exhibits transparency, which is a characteristic of dye coloring,
Moreover, since the finger and the fixing roll are not contaminated and the charging characteristic is stable and uniform, the image formation is stable even during continuous copying, and the stability of the obtained image is good. Is to have.

[0044]

[Table 1]

[0045]

[Table 2]

[0046]

[Table 3]

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yozo Yamada 2-1-1 Katata, Otsu City, Shiga Prefecture Toyobo Co., Ltd.

Claims (1)

[Claims] 1. A xanthene-based basic dye "CI Basic" in the form of forming a salt with an anionic group present at a side chain and / or at an end of a polymer chain of a binder resin.
An electrophotographic toner comprising a cation portion of a dye classified as "Violet 11" and substantially not containing a chloride ion which is a counter ion of the dye.