JPH0764334A - Electrophotographic toner - Google Patents

Abstract

PURPOSE:To obtain an electrophotographic color toner using a dye excellent in hue and transparency as a process color and ensuring a low coloring cost and excellent in light resistance by using a specified compd. as an essential component. CONSTITUTION:This electrophotographic toner contains a compd. represented by the formula as an essential component. In the formula, each of R1 and R2 is H, optionally branched alkyl, alkoxy, phenyl which may have a substituent or benzyl which may have a substituent, at least one of R1 and R2 is >=5C substituent and X is H, optionally branched alkyl or halogen. The resin binder of this toner is not especially limited but a resin based on polyester resin is preferably used. Polyols used in the polyester resin are aliphatic polyols, alicyclic polyols, arom. polyols, etc.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a toner used as a developer in electrophotographic copying machines, laser printers, facsimiles and the like.

[0002]

2. Description of the Related Art Generally, the electrophotographic method is a photoconductive material of inorganic type such as selenium, amorphous silicon, zinc oxide or the like, or organic type such as diazo compound or dye (often processed into a drum shape). (: Photosensitive drum) is uniformly charged, then an electrostatic latent image is formed by irradiating the image-modulated light, and the electrostatic latent image is developed by adhering powder by electrostatic force. Then, the powder is transferred onto a base material such as paper or film, if necessary, and then fixed by a method such as pressing or heating. The electrophotographic system is currently widely used in copiers, laser printers, facsimiles and the like. A powder that develops an electrostatic latent image on a photosensitive drum in an electrophotographic system and is finally transferred to a base material such as paper or film to form an image is called a toner. Conventionally, a toner for electrophotography is produced by a so-called pulverization method in which a coloring agent, a charge control agent, a fluidity modifier, a pulverization auxiliary agent, etc. are added to a thermoplastic resin, kneaded, pulverized, and further classified. Particles have been used. In recent years, in order to meet the demand for higher image quality, that is, higher definition and color, toners have been made finer, narrower in particle size distribution, and colorized. Colors used to form color images in electrophotography
As the toner, a process color, that is, a toner colored in three subtractive primary colors: yellow, magenta, cyan, and black is used.

[0003]

Pigments or dyes are used as coloring materials. In 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 by reducing the particle size of the pigment particles to the wavelength of light or less, that is, submicron. However, it is technically difficult to pulverize the pigment to a submicron size, and the colorant dispersion cost is significantly increased. Further, it is difficult to uniformly disperse the pigment pulverized to submicron size in the resin, and as a practical matter, it exists as an aggregate aggregate in the resin to some extent.
The crushed effect cannot be fully utilized. Further pulverization may impair the high light fastness characteristic of the pigment. Attempts have been made to use dyes for coloring color toners in order to improve the drawbacks of pigmentation. When a dye is used as a colorant, it is transparent and has a high saturation, and a hue close to an ideal process color is obtained. Further, unlike a pigment, a dispersing step is not required, which is advantageous in terms of manufacturing cost. However, many dyes are inferior in light resistance to pigments, and few are particularly satisfactory in terms of retaining color images.

For the purpose of improving the light resistance, it has been proposed to blend an ultraviolet absorber and the like into the toner. For example, in JP-A-2-264965, it is proposed to blend a benzotriazole-based ultraviolet absorber into a toner.
However, such an ultraviolet absorber has a sublimation property at a high temperature, and it bleeds when kneading a binder resin, a coloring material, each additive, etc. to contaminate the production line remarkably and fix the toner. However, there are problems such as contaminating the fixing hot roll used at the time of degrading and deteriorating the offset property.

[0005]

In view of such circumstances, the present inventors have excellent color and transparency as a process color,
As a result of repeated studies to obtain an electrophotographic color toner which is excellent in light resistance and which uses a dye having a low coloring cost, the following invention has been reached. That is, the present invention provides the general formula 1
An electrophotographic toner containing the compound represented by
Is.

The binder resin for the electrophotographic toner of the present invention is not particularly limited, and polyester resins, polystyrene resins, poly (meth) acrylic acid ester resins, styrene / (meth) acrylic acid ester copolymers are used. A resin, a polyvinyl resin, an epoxy resin, a polyurethane resin, or the like can be used. However, the resin most preferably used is a resin containing a polyester resin as a main component. Polyester resin is 40 wt% or more of binder resin,
It should preferably occupy 60 wt% or more, more preferably 80 wt% or more. 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] isophthalic acid,
Aromatic dicarboxylic acids such as sulfoterephthalic acid and / or their metal salts and ammonium salts, aromatic oxycarboxylic acids such as p-oxybenzoic acid and p- (hydroxyethoxy) 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, and other unsaturated aliphatic and alicyclic dicarboxylic acids, and other polyvalent carboxylic acids such as trimellitic acid, trimesic acid, and pyromellitic acid. The polyvalent carboxylic acid and the like can be exemplified.

Examples of the polyvalent alcohols used in 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 aromatic polyhydric alcohols, paraxylene glycol, metaxylene glycol, orthoxylene glycol, 1,4-phenylene glycol, and ethylene oxide adduct of 1,4-phenylene glycol. , Bisphenol A, ethylene oxide adduct of bisphenol A, propylene oxide adduct and the like. Further, examples of the polyester polyol include lactone polyester polyols obtained by ring-opening polymerization of lactones such as ε-caprolactone.

(Monofunctional Monomer) Polyester A monofunctional monomer may be introduced into polyester for the purpose of blocking polar groups at the polymer terminal and improving the environmental stability of toner charging characteristics. Examples of monofunctional monomers include benzoic acid, chlorobenzoic acid, bromobenzoic acid, parahydroxybenzoic acid, sulfobenzoic acid monoammonium salt, sulfobenzoic acid monosodium salt, cyclohexylaminocarbonylbenzoic acid, n-dodecylaminocarbonylbenzoic acid. Acid, tar
Char-butylbenzoic acid, naphthalenecarboxylic acid, 4-methylbenzoic acid, 3-methylbenzoic acid, salicylic acid, thiosalicylic acid, phenylacetic acid, acetic acid, propionic acid, butyric acid,
Monocarboxylic acids such as isobutyric acid, octanecarboxylic acid, lauric acid, stearyl acid, and lower alkyl esters thereof, or monoalcohols such as aliphatic alcohols, aromatic alcohols, and alicyclic alcohols. Can be used.

In the present invention, 7 of the polycarboxylic acids are used.
It is preferable that 0 mol% or more is an aromatic polycarboxylic acid. When the content of the aromatic polyvalent carboxylic acid is low, the glass transition temperature of the polyester resin may be lowered, and the storage stability of the toner may be deteriorated. As more specific examples of the polyester resin in the present invention, a) polyvalent carboxylic acids containing 80 mol% or more of an aromatic monomer, and b) ethylene glycol 0 to 90 mol%, propylene glycol 100. Polyester resin obtained from 10 to 10 mol% a) polycarboxylic acid containing 80 mol% or more of an aromatic monomer, and b) 2,3-butanediol 5 to 80 mol%, ethylene glycol 20 to Polyester resin obtained from 95 mol% a) Polycarboxylic acid containing 80 mol% or more of an aromatic monomer, b) 70 to 95 mol% of C2 to C4 aliphatic glycols, and c) tricarboxylic acid. Polyester resin obtained from 5 to 30 mol% of mono and / or polyalcohol having a cyclodecane skeleton a) Polycarboxylic acid containing 80 mol% or more of an aromatic monomer, and b) C2 to C4 aliphatic glycols 70-9 mol%, c) mono and / or polyhydric having cyclohexane skeleton alcohol -
Polyester resin obtained from 5 to 30 mol% of a) a) Polycarboxylic acid containing 80 mol% or more of an aromatic monomer containing 1 to 20 mol% of mono and / or dicarboxylic acid having a naphthalene skeleton , And b) C2 to C4 aliphatic glycols 70 to 100 mol
%, C) Polyvalent alcohol containing 0 to 30 mol% of alicyclic monomer
Examples thereof include polyester resins and the like obtained from Here, the “a) aromatic monomer” is preferably terephthalic acid and / or isophthalic acid. The ratio of terephthalic acid to isophthalic acid is terephthalic acid content / isophthalic acid content = 90 to 40/10
To 60 [mol%] is preferable, and further terephthalic acid content / isophthalic acid content = 80 to 50/20 to 50 [mo]
l%], and further terephthalic acid content / isophthalic acid content = 85-60 / 15-40 [mol%] is preferable.

In the present invention, 2 to 5 mol% of trimellitic acid and / or trimesic acid and / or pyromellitic acid can be contained as an aromatic monomer. In the present invention, in addition to such polyvalent carboxylic acid, it is acceptable to use a polyhydric alcohol having a valence of 3 or more, but the purpose is to broaden the molecular weight distribution of the polyester resin, and to gel the resin. The purpose is not to let. 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 preferable 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.

In the present invention, 1 is added to the polyester resin.
It is preferable to contain an ionic group in the range of 0 to 1000 eq./ton. The content of ionic groups is 10 to 10
00m equivalent / 1000g is preferable, and further 20-50
0 m equivalent / 1000 g, more preferably 50 to 200 m
Equivalent weight / 1000 g. As the ionic group, a sulfonic acid alkali metal salt group, and / or a sulfonic acid ammonium salt group, and / or a carboxylic acid alkali metal base, and / or a carboxylic acid ammonium salt group, a sulfuric acid group, a phosphoric acid group, a phosphonic acid group, Phosphinic acid groups or their ammonium salts, anionic groups such as metal salts,
Alternatively, a cationic group such as a primary to tertiary amine group can be used. In the present invention, as an aromatic monomer, 0.1 to 6.0 mol% of a mono-and / or dicarboxylic acid having an alkali metal sulfonate and / or an ammonium sulfonate base is contained to make the polyester resin ionic. A group can be introduced. As salts, ammonium-based ions, Li, Na, K, Mg, Ca,
Examples thereof include salts of Ba, Cu, Fe, Ni, Co, Zn and the like, and particularly preferable ones are Ca salts or Mg salts. When introducing a carboxylate alkali metal base and / or a carboxylate ammonium base, a carboxyl group is added to the polymer terminal by introducing a polyvalent carboxylic acid such as trimellitic acid into the system at the final stage of polymerization of polyester. Further, a method of exchanging it with a carboxylate group by neutralizing it with ammonia, sodium hydroxide or the like can be used. Such an ionic group has a function as a dyeing seat for a basic dye, a cationic dye, an acid dye, etc., which will be described later, and also has a function for imparting water dispersibility, which will be described later, to the polyester resin.

In the present invention, a pigment or a dye can be used as the coloring material. The coloring material preferably used in the present invention is a dye. As the dye, a disperse dye, an oil-soluble dye, a construction bath dye, a vat dye, a slene dye, a basic dye, a cationic dye, an acid dye, a reactive dye, a reactive disperse dye and the like can be used. Specific examples of the disperse dye and the oil-soluble dye include C.I. I. Disperse Yellow 42 C.I. I. Disperse Yellow 198 C.I. I. Solvent Yellow 162 C.I. I. Disperse Red 92 C.I. I. Solvent Red 49 C.I. I. Solvent Red 52 C.I. I. Disperse Violet 26 C.I. I. Disperse Violet 35 C.I. I. Disperse Blue 60 C.I. I. Disperse Blue 87 C.I. I. Solvent Blue 70 C.I. I. At least one dye selected from Solvent Black 3 is preferably used. The content of disperse dye is 0.1 to 1 with respect to the binder resin.
It is 0% by weight, preferably 0.5 to 5% by weight, more preferably 1 to 4% by weight. Specific examples of basic dyes include C.I. I. Basic Yellow 11 C.I. I. Basic Yellow 13 C.I. I. Basic Yellow 21 C.I. I. Basic Red 14 C.I. I. Basic Red 15 C.I. I. Basic Red 39 C.I. I. Basic Violet 7 C.I. I. Basic Violet 11 C.I. I. Basic Violet 28 C.I. I. Basic Violet 40 C.I. I. Basic Violet C.I. I. Basic Blue 3 C.I. I. At least one dye selected from Basic Blue 75 is preferably used. When such a basic dye is used, it is preferable that the binder resin contains an anionic group to serve as a dyeing seat, and the dye is present in the side chain and / or the end of the binder resin polymer chain. The cation moiety of the basic dye is contained in the form of forming a salt with the anionic group, and the anion (mainly halogen ion, generally chlorine ion) which is a counter ion of the basic dye is substantially not contained. preferable. More specifically, the content of halogen ions (in the form of a salt with a halogen acid or an alkali metal ion or an alkaline earth metal ion) is preferably 2 eq./ton or less. Such a preferable state is realized by dyeing the anionic group-containing resin in an aqueous medium. The dyes exemplified above are particularly excellent in fastness to light, fastness to sublimation, hue, and saturation.
It is preferable as the three primary colors. In addition, known dyes and pigments may be used in combination for fine adjustment of hue. As a pigment used in combination: C.I. I. Pigment Yellow 14 C.I. I. Pigment Yellow 17 C.I. I. Pigment Red 48 C.I. I. Pigment Red 57 C.I. I. Pigment Red 81 C.I. I. Pigment Red 122 C.I. I. Pigment Red 183 C.I. I. Pigment Red 184 C.I. I. Pigment Blue 15 C.I. I. Pigment Blue 16 is preferably used. Carbon black or the like may be used to obtain a black toner. As the carbon black, thermal black, acetylene black, channel black, furnace black, lamp black and the like can be used.

In the general formula 1, R1 and R2 are each independently hydrogen, an optionally branched alkyl group, an alkoxy group,
A phenyl group which may have a substituent and a benzyl group which may have a substituent are shown, but it is essential that at least one of them is a substituent having 5 or more carbon atoms, preferably 8 carbon atoms.
As described above, more preferably, it has 9 or more carbon atoms. Specifically, an amyl group, a tert-amyl group, an octyl group, a tert-octyl group, a benzyl group, an α, α'-dimethylbenzyl group, 3,4,5,6-tetrahydrophthalimide-
A methyl group and the like are preferable. More specifically, 2 (2'-hydroxy-5'-octylphenyl) benzotriazole,
2 [2'-hydroxy-3- (3,4,5,6-tetrahydrophthalimido-methyl) -5-methylphenyl]
Benzotriazole, 2 [2'-hydroxy-3 ', 5'-bis (α, α'-dimethylbenzyl) phenyl] -2H-benzotriazole, 2 (2'-hydroxy-3', 5'-diter -Charamylphenyl) benzotriazole, etc. are preferred. The compounding amount of the compound represented by the general formula 1 is 0.05 to 5.0 wt% with respect to the binder resin, preferably 0.1 to 2.0 wt%, more preferably 0.2 to
It is 1.0 wt%. When neither R1 nor R2 has a substituent having 5 or more carbon atoms, the sublimability of the compound is high, resulting in a problem in toner production, or a problem such as an offset due to contamination of the fixing roll. Occurs. The above are the essential requirements that characterize the electrophotographic toner of the present invention.

In the present invention, singlet oxygen quencher
In some cases, a more preferable effect may be obtained by using together. As the singlet oxygen quencher, nickel complex compounds such as diazabiscyclooctane and carotene can be used. The nickel complex compound is 2,
2'-thio-bis (4-octylphenyl) nickel,
Nickel acetylacetonate, bis (dithiobenzyl) nickel, bis (4,4'-dimethoxydithiobenzyl) nickel, tetrabutylammonium salt of bis (dithiobenzyl) nickel, bis (4,4'-dimethoxydithiobenzyl) ) Nickel tetotabutylammonium salt, 2,2'-thio-bis (4-tert-charoctylphenolate) -tert-butylamine-nickel salt, 2,2'-thio-bis (4-tert-) Charoctylphenolate) -tert-charoctylamine / nickel salt, 3,5-di-charbutyl-4-hydroxybenzylmonoethylphosphonate nickel, dimethyldicarbamate nickel, diethyldicarbamate nickel, Nickel dibutyl dicarbamate, Nickel dimethyldithiocarbamate, Diet Dithiocarbamate nickel, nickel dibutyldithiocarbamate and the like are preferably used. The content of these singlet oxygen quenchers is 0.01 to 5.0% by weight, preferably 0.02 to 1.0% by weight, more preferably 0.0 to 5.0% by weight, based on the binder resin.
It is about 5 to 0.5% by weight.

(Production Method) Electrophotographic toner according to the present invention
As a specific method for obtaining, a general binder resin, a dye, a compound represented by the general formula 1, a colorant, a wax, a charge control agent, etc. are kneaded, and then pulverized and classified. The crushing method can be used. Further, a monomer which becomes a binder resin by polymerization, an initiator, a dye, a compound represented by the general formula 1, a coloring material, a wax,
It is also possible to use a polymerization method in which a charge control agent or the like is kneaded or dissolved, and then suspended and polymerized in an aqueous medium.

(Shape / morphology) In the present invention, the shape / morphology of the electrophotographic toner is not limited, but preferably the average particle diameter (sphere equivalent diameter) D is 2 to 30.
Within the range of μm, and the coefficient of variation of particle size distribution is 25%
Or less, preferably 15% or less, more preferably 10%
The following can be used. Further, it is preferable that the ratio of the actual specific surface area to the specific surface area arithmetically calculated from the equivalent spherical diameter, that is, the specific surface area ratio is in the range of 1 to 5 and has a certain form. Average particle diameter (sphere equivalent diameter) D
Is less than 2 μm, handling as powder becomes difficult. If it is 30 μm or more, it is not suitable as a toner for high-definition images, and the resolution of the obtained image is lowered. The average particle diameter is more preferably in the range of 2 to 10 μm, and further preferably in the range of 3 to 7 μm.

(Production Method of Polyester Particles) Toner particles having such a preferable form can be preferably obtained when an ionic group-containing polyester resin is used as the binder resin. Such an ionic group-containing polyester resin exhibits water dispersibility. The aqueous fine dispersion of the ionic group-containing polyester resin of the present invention can be produced by any known method. That is, the ionic group-containing polyester resin and the water-soluble organic compound are premixed at 50 to 200 ° C. and water is added thereto, or the mixture of the ionic group-containing polyester resin and the water-soluble organic compound is added to water. In addition, it is manufactured by stirring at 40 to 120 ° C. Alternatively, an ionic group-containing polyester resin is added to a mixed solution of water and a water-soluble organic compound,
It is also produced by a method of stirring and dispersing at 0 ° C.
As the water-soluble organic compound, ethanol, butanol, isopropanol, ethyl cellosolve, butyl cellosolve, dioxane, tetrahydrofuran, acetone, methyl ethyl ketone, etc. can be used. It is not preferable to use a surfactant together, but the use is not particularly limited. The average particle size of the water-based fine dispersion thus obtained is about 0.01 to 1.0 μm. In the aqueous microdispersion of the ionic group-containing polyester resin, under conditions where the ionic group-containing polyester resin is plasticized, by means such as addition of an electrolyte or the like, the finely dispersed particles are guided to a slow aggregation region, and particle growth occurs. By doing so, polyester particles can be obtained.

(Electrolyte / Electrolyte Precursor) As the electrolyte used in the present invention, sodium sulfate, ammonium sulfate, potassium sulfate, magnesium sulfate, sodium phosphate, sodium dihydrogen phosphate, disodium hydrogen phosphate, ammonium chloride, chloride Calcium, cobalt chloride, strontium chloride, cesium chloride, barium chloride, nickel chloride, magnesium chloride, rubidium chloride, sodium chloride, potassium chloride, sodium acetate,
A general inorganic or organic water-soluble salt represented by ammonium acetate, potassium acetate, sodium benzoate and the like can be used. The concentration of these electrolytes is 0.01 to 2.0 mol / l when a monovalent electrolyte is used, and moreover, 0.1.
1-1.0 mol / l, or even 0.2-0.8 mol / l
Is preferred. Further, when a polyvalent electrolyte is used, its addition amount may be smaller. In the present invention, the objective can be sufficiently achieved by preliminarily charging the electrolyte into the system, or by post-adding it, but preferably by "electrolyzing after adding the electrolyte precursor" Further, good quality polyester resin particles can be obtained. Examples of the electrolyte precursor include salts that are sparingly soluble at low temperatures and easily soluble at high temperatures, compounds that decompose into electrolytes by pH, temperature, pressure, light irradiation, and the like.
In the present invention, ester compounds of amino alcohols and carboxylic acids can be used as preferred electrolyte precursors. Since such an ester compound has an amino group, it is water-soluble, and its aqueous solution is alkaline. When the temperature of the alkaline aqueous solution is raised, the ester bond is hydrolyzed to form a salt of amino alcohol and carboxylic acid. The amino group actually functions as a primary ammonium group or a tertiary ammonium group. Preferred amino alcohols in the present invention include amino ethanol, 1,3-amino propanol, 1,4-amino butanol, dimethylamino ethanol and 1,3-dimethylamino propanol.
, Diethylaminoethanol, diethylaminopropanol and the like can be used. Examples of the carboxylic acids include benzoic acid and its derivatives, naphthalenecarboxylic acid, and its derivatives, salicylic acid, thiosalicylic acid, phenylacetic acid, acetic acid, propionic acid, butyric acid, octanoic acid, decanoic acid, dodecanoic acid, lauric acid, stearyl acid, Acrylic acid, methacrylic acid, etc. can be used. Further, in the present invention, an ester in any combination of these amino alcohols and carboxylic acids can be preferably used as the electrolyte precursor.

(Asphericization) In the present invention, the slow aggregation is carried out within the range of the glass transition temperature of the polyester resin ± 15 ° C, preferably within the range of the glass transition temperature + 5 ° C to the glass transition temperature -15 ° C, and more preferably within the range. Glass-transition temperature~
Non-spherical particles can be obtained by realizing the glass transition temperature within the range of -10 ° C. Further, when the polyester resin is slowly aggregated at a temperature exceeding the glass transition temperature + 15 ° C, substantially spherical particles are produced. Such spherical particles are in the vicinity of the glass transition temperature, preferably + 5 ° C to-.
Non-spherical particles can be obtained by performing compression treatment in a temperature range of about 20 ° C. and then crushing.

(Pigment Incorporation by Coaggregation) (Washing / Drying) Different kinds of aqueous dispersions can be incorporated into the polyester resin particles of the present invention by heteroaggregation during the particle growth process. It is also possible to use a fine polyester microdispersion colored with a dye or the like. In this way it is possible to color and functionalize the particles. Dispersed water dispersions are, for example, pigments, latex, wax, carbon black,
It is a dispersion of a charge control agent or the like. The obtained particles are washed and dehydrated, and then taken out as a dry powder by means such as freeze-drying, spray-drying, fluidized-drying, and vacuum-drying, and subjected to a known external additive treatment such as a fluidity improver and a charge control agent. Become a toner.

The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. [Polymerization of polyester resin] In an autoclave equipped with a thermometer and a stirrer, 78 parts by weight of dimethyl terephthalate, 116 parts by weight of dimethyl isophthalate, 96 parts by weight of ethylene glycol, propylene glycol 50 parts by weight of tetrauret and 0.1 part by weight of tetrabutoxytitanate were charged and heated at 180 to 230 ° C. for 120 minutes to carry out a transesterification reaction. Next, the reaction system was heated to 250 ° C., and the reaction was continued for 60 minutes at a system pressure of 1 to 10 mmHg, and as a result, a copolyester resin (A1) was obtained. As a result of NMR analysis, the obtained copolyester resin (A1) was found to have about 4 terephthalic acid relative to the acid component.
0 mol% isophthalic acid About 60 mol% Ethanol glycol 72 mol% Propylene glycol 28 mol% as an alcohol component. In the same manner as described below, Table 1. To obtain polyester resins (A2) to (A4).

In an autoclave equipped with a thermometer and a stirrer, 136 parts by weight of dimethyl terephthalate, 56 parts by weight of dimethyl isophthalate, 68 parts by weight of ethylene glycol, and bisphenol A were added. 175 parts by weight of an ethylene oxide adduct (average molecular weight 350) and 0.1 part by weight of tetrabutoxy titanate were charged and heated at 150 to 220 ° C. for 180 minutes to carry out a transesterification reaction. Then, after raising the temperature to 240 ° C.,
Gradually reduce the system pressure to 10 mmHg after 30 minutes,
The reaction was continued for 60 minutes. After that, the atmosphere in the autoclave was replaced with nitrogen gas and the pressure was adjusted to atmospheric pressure. The temperature was kept at 200 ° C., 2 parts by weight of trimellitic anhydride was added, and the reaction was carried out for 60 minutes to obtain a copolyester resin (A5). The acid value of the obtained copolyester resin was 2.1 KOHmg. An autoclave equipped with a thermometer and a stirrer was charged with 70 parts by weight of an ethylene oxide adduct of bisphenol A, 19.6 parts by weight of maleic anhydride (MA), and 0.2 parts by weight of hydroquinone. Nitrogen gas was introduced into the reaction system to maintain an inert atmosphere, 0.05 part by weight of dibutyltin oxide was added, and the reaction was carried out at 200 ° C. to obtain a polyester resin (A6). Table 1. Medium, TBBA is tertiary butyl benzoic acid, NDC is 1,5 naphthalene dicarboxylic acid,
TPA is terephthalic acid, IPA is isophthalic acid, SIP is 5 sodium sulfoisophthalic acid, TMA is trimellitic acid,
EG is ethylene glycol, PG is propylene glycol
, CHD is cyclohexanediol, TCDD is tricyclodecane dimethanol, BPE is an ethylene oxide adduct of bisphenol A (average molecular weight 350), and Tg is a glass transition temperature.

[0023]

Example 1 (Preparation of toner 1: crushing / classifying method) (a) Polyester resin (A1) 9 as binder resin
7.0 parts by weight, (b) Yellow dye "CI Solvent Ye
"low 162" 2.0 parts by weight, 2 [2'-hydroxy-3- (3,4,5,6-tetrahydrophthalimido-methyl) -5-methylphenyl] benzotriazo-as a compound corresponding to the general formula 1. 1.0 part by weight of the resin was melt-kneaded in an extruder. The temperature during kneading was 180 ° C. Then, after coarse pulverization with a chopper mill, fine pulverization with a supersonic jet mill, and 5 μm or less and 15 μm or more were removed by dry classification. 2 parts by weight of silica fine powder (trade name Aerosil) was mixed with 100 parts by weight of the obtained finely pulverized particles in a Henschel mixer to obtain a yellow toner having an average particle size of 9.8 μm. Similarly, the dye and polyester resin are replaced in the same manner as shown in Table 2. The toner shown in FIG. Concentrated dyes were used for all the dyes. Further, no particular abnormality was observed in the equipment used for manufacturing the toner such as the extruder. Obtained toner
5 parts by weight and ferrite carrier F-100 [powder-
95 parts by weight, manufactured by Tec Co., Ltd., was stirred and mixed with a ball mill to obtain a two-component developer. Using the obtained two-component developer, a rectangular solid pattern of 7 cm × 7 cm was formed by an OPC: electrophotographic digital copying machine having an organic photosensitive drum. The thickness of the toner layer is 0. D. The (reflected optical density) was standardized to fall within the range of 1.3 to 1.7.
The obtained pattern was subjected to an ultraviolet exposure test for 60 hours using an ultraviolet fade meter (63 ° C.), and the CI before and after the exposure test was measured.
The color difference ΔE in the ELAB1976 chromaticity coordinate system is shown in Table 2 below. Shown in.

[0024]

Example 2 In addition to Example 1, a singlet oxygen quencher was added.
As 2,2'-thio-bis (4-tertiaryoctylphenolate) -tertiarybutylamine / nickel salt was added in an amount of 0.5 parts by weight to prepare a sample under the same composition and conditions. An exposure test was conducted in the same manner. The results are shown in Table 2. Shown in. No particular abnormality was observed in the equipment used for the toner production. ,

[0025]

Comparative Example 1 Examples 1 to 2 [2'-hydroxy-3-
(3,4,5,6-tetrahydrophthalimido-methyl) -5-methylphenyl] benzotriazole was added to 2
A sample was prepared under the same composition and conditions except that [2′-hydroxy-3,5dimethylphenyl] benzotriazole was used, and the same exposure test was performed. The results are shown in Table 2.
Shown in. Light yellow crystals were precipitated inside the extruder used for kneading, and as a result of analysis, it was found to be 2 [2′-hydroxy-3,5dimethylphenyl] benzotriazole. As a result of quantifying the ultraviolet absorber contained in the obtained toner, it was found that the toner contained only about 3/5 to 1/2 of the charged amount.

[0026]

Comparative Example 2 Examples 1 to 2 [2'-hydroxy-3-
Except for only (3,4,5,6-tetrahydrophthalimido-methyl) -5-methylphenyl] benzotriazole, a sample was prepared under the same composition and conditions except for the above, and an exposure test was conducted in the same manner. The results are shown in Table 2. Shown in. Toner
No particular abnormality was observed in the equipment used for production.

[0027]

Example 3 [Preparation of Polyester Water Dispersion] 100 parts by weight of a polyester resin (A2) was placed in a four-necked 10 liter separable flask equipped with a thermometer, a condenser and a stirring blade.
“2 [2′-Hydroxy-3 ′, 5′-bis (α, α′-dimethylbenzyl) phenyl] -benzotriazole” 1.
0 parts by weight and 75 parts by weight of butyl cellosolve were added and dissolved at 70 ° C. Next, after adding 500 parts by weight of ionized water at 70 ° C. to disperse the water, the distillation fraction was heated to 1 at a distillation flask.
It was distilled until it reached 00 ° C., and after cooling, water was added to make the solid content concentration 30%. The finely dispersed particles present in the obtained polyester aqueous dispersion had an average particle size of 0.2 μm and a zeta potential of −52 mV. In the same manner, fine water dispersions were obtained from the polyester resins (A3) and (A4).

100 parts by weight of polyester resin (A5),
"2 [2'-hydroxy-3 ', 5'-bis (α, α'-dimethylbenzyl) phenyl] -benzotriazole" 1.0
Parts by weight, butanol 50 parts by weight, methyl ethyl ketone 1
0 parts by weight and 20 parts by weight of isopropanol were added and dissolved at 70 ° C. Further, 1N aqueous ammonia solution was added so that the acid value of the copolyester was equal to the acid value, and the mixture was stirred at 70 ° C for 30 minutes and then 300 parts of water at 70 ° C was added to obtain an aqueous microdispersion of the copolyester. It was Further, the obtained water dispersion is put into a distillation flask and the distillation temperature is 100 ° C.
The mixture was distilled until the temperature reached, and the solid content was adjusted with deionized water to finally obtain a solvent-free aqueous dispersion of copolymerized polyester having a solid content concentration of 30%. Similarly, an aqueous fine dispersion was obtained from the polyester resin (A6).

[Preparation of Polyester Particles] The polyester aqueous dispersion 10 obtained was placed in a four-necked 5 liter separable flask equipped with a thermometer, a condenser and a stirring blade.
00 parts by weight and 65 parts by weight of dimethylaminoethyl (2,2 dimethylol) propionate as an electrolyte precursor were charged. Then, the temperature was raised to 75 ° C. and stirring was continued for 240 minutes. The finely dispersed particles present in the water-based finely dispersed body grew as a united particle to obtain polyester particles having an average particle diameter D of 6.5 μm and a coefficient of variation of particle size distribution of 9.4% by a coulter counter method. . The obtained particles are dehydrated and washed with a suction funnel and redispersed in deionized water to obtain a solid content of 2
A 5% by weight aqueous dispersion of polyester particles was obtained. 10 parts by weight of the basic dye "CI Basic Yellow 21", 30 parts by weight of a formalin condensate of sodium naphthalenesulfonate, and 200 parts by weight of deionized water were charged into a flask, boiled with stirring, and then cooled to disperse anions. A type cationic dye was obtained. 1000 parts by weight of an aqueous dispersion of polyester particles was added to the obtained anion-dispersion type cationic dye, heated to 130 ° C., held for 30 minutes, cooled and dehydrated and washed, and vacuum dried to obtain colored polyester dry particles. . 2 parts by weight of silica fine powder (trade name Aerosil) was mixed with 100 parts by weight of the obtained colored particles in a Henschel mixer to obtain a yellow toner having an average particle size of 6.5 μm.
Similarly, the dye and the polyester water microdispersion are replaced in the same manner as shown in Table 3. The toner shown in FIG. 5 parts by weight of the obtained toner and a ferrite carrier F-100 [manufactured by Powder Tech Co., Ltd.]
95 parts by weight were mixed with a ball mill with stirring to obtain a two-component developer. Using the obtained two-component developer, a rectangular solid pattern of 7 cm × 7 cm was formed by an OPC: electrophotographic digital copying machine having an organic photosensitive drum. The thickness of the toner layer is 0. D. (Reflection optical density) is 1.3 to
It was standardized to fall within the range of 1.7. The obtained pattern
The sample was subjected to an ultraviolet ray exposure test for 60 hours with an ultraviolet ray fader (63 ° C.), and the color difference ΔE in the CIELAB1976 chromaticity coordinate system before and after the exposure test is shown in Table 3 below. Shown in.

[0030]

Comparative Example 3 From Example 2, “2 [2′-hydroxy-3 ′,
5'-bis (α, α'-dimethylbenzyl) phenyl] -benzotriazol "and" 2-hydroxy-4-methoxybenzophenone "are the same except that the sample is prepared under exactly the same composition and conditions. An exposure test was conducted on. The results are shown in Table 3. Shown in. (Image forming test) Among the toners obtained in Example 1, the polyester resin (A6) and the dye "Solvent Yellow"
162 "," Solvent Red 52 ", and" Disperse Blue 60 "are used, and toners of three colors of yellow, magenta, and cyan are used, respectively, and continuous with the electrophotographic digital copying machine used in the embodiment. A color image forming test having gradation was performed. The obtained image was excellent in gradation reproducibility and intermediate color reproducibility, and had a resolution of 400 DPI or more. Among the toners obtained in Example 2, polyester resin (A
2), dye "Basic Yellow 21", "Basic Violet
A color image forming test having continuous gradation was similarly performed using toners of three colors of yellow, magenta, and cyan obtained from "7" and "Basic Blue 3", respectively. The obtained image has excellent gradation reproducibility and intermediate color reproducibility, and the resolution is 800DP.
It was I or more. Similarly, polyester resin (A3)
A color image forming test having continuous tone was similarly performed using each of the toners of three colors obtained from (A6), and all the obtained images were excellent in tone reproducibility and intermediate color reproducibility. ,
The resolution was 800 DPI or higher. Using these toners, a color image having a continuous tone was similarly formed on a transparent film for an over head projector and projected on a white screen for observation. For comparison, a commercially available color toner (a pigment is used as a coloring material) was used to form an image in the same manner, and the image was projected on a white screen and observed. When the toner of the present invention was used, a high-saturation projection image was obtained, but when the commercially available toner was used, the overall color tone was slightly dull, and especially the intermediate color portion had a slightly dark color tone.

[0031]

As described above, the toner for electrophotography of the present invention has an excellent image forming ability, the storage stability of the obtained image is high, and the production equipment is not contaminated. And so on, it has excellent properties in terms of manufacturing cost and has an extremely high value industrially.

[0032]

[Table 1]

[0033]

[Table 2]

[0034]

[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. An electrophotographic toner comprising a compound represented by the general formula 1 as an essential component. [Chemical 1] In the chemical formula 1, R1 and R2 are each independently hydrogen, an alkyl group which may be branched, an alkoxy group, a phenyl group which may have a substituent, a benzyl group which may have a substituent, but at least one of them. Represents a substituent having 5 or more carbon atoms X: hydrogen, an alkyl group which may be branched, and a halogen.