JPH0519536A - Combination of electrostatic charge developing color toner - Google Patents

Abstract

PURPOSE:To allow the formation of bright transferred images having the colors approximate to natural colors by respectively specifying the coloring agents of the magenta toner, yellow toner, cyan toner, and black toner. CONSTITUTION:The naphthol org. pigment expressed by formula I is incorporated as a coloring agent into the magenta toner and the disazo org. pigment expressed by formula II is incorporated as a coloring agent into the yellow toner. A beta type copper phthalocyanine pigment and polychlorocopper phthalocyanine pigment are incorporated as coloring agents into the cyan toner. At least one kind selected from a group consisting of an isoindolinone yellow pigment and tetrachloroisoindolinone yellow pigment, at least one kind selected from a group consisting of a quinacridone red pigment and perylene red pigment, and a phthalocyanine blue pigment are incorporated as coloring agents into the black toner. The change in the electrostatic charge quantity value is decreased as against the change in the environmental conditions from a low temp. and low humidity to a high temp. and high humidity in this way.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color toner for developing an electrostatic image in electrophotography, electrostatic recording, electrostatic printing and the like.

[0002]

2. Description of the Related Art In electrophotography, an electrostatic latent image carrier, which is usually a photoconductive photosensitive member, is charged and exposed to form an electrostatic latent image, which is then colored in a binder resin. It is a method of forming a visible image by developing with a toner containing an agent and transferring and fixing the obtained toner image on a support such as transfer paper. Generally, a toner obtained by dispersing a black colorant such as carbon black in a binder resin is often used as a toner for obtaining such a visible image, but in recent years, a cyan color pigment, a magenta color pigment or a yellow color pigment has been used. Color toners in which pigments are dispersed in a binder are also used. Among these, there are also color toners used for obtaining a multicolor image by an electrophotographic method, and usually four color toners of cyan color, magenta color, yellow and black are used.

In the case of such a color toner, it is also required that a color image obtained by transferring and fixing on a sheet of an overhead projector (hereinafter referred to as OHP) sheet to display a clear color on the screen by the transmitted light of the OHP. ing. Generally, the composition of a color toner comprises a binder resin, a main component of a colorant, and various additives. As the binder resin, polystyrene, styrene (meth) acrylic acid ester copolymer, styrene-butadiene copolymer, polyester, epoxy resin, coumarone indene resin, etc. are generally used. In order to obtain a multicolor image of this color, an electrostatic latent image is formed by the light of each color obtained by separating the original with a color separation filter, and yellow, magenta, and A method is used in which color toner such as cyan is repeatedly developed and then transferred and fixed on paper or the like. Conventionally, many techniques have been disclosed for such color toners, and particularly for magenta or red color toners, a technique relating to a magenta toner using a quinacridone pigment in JP-A-51-24234 is disclosed. Kaisho 5
Japanese Patent Application Laid-Open No. 9-165069 and Japanese Patent Application Laid-Open No. 62-296167 disclose techniques relating to magenta toners using various monoazo pigments.

[0004]

However, it is difficult for these color toners of the prior art to maintain a stable charge amount under conditions of low temperature and low humidity, high temperature and high humidity, and image characteristics against environmental changes. Had the drawback of being extremely unstable. In addition, a transferred image obtained by repeatedly developing magenta, cyan, yellow, and black color toners and transferring the toners onto paper or the like is generally required to have an image quality close to a natural color. For that, magenta, cyan,
It is important that the yellow and black monochromatic toners have excellent tinting strength and good color reproducibility, and therefore improvements have been demanded.

An object of the present invention is to provide a good and stable transferred image quality with a small charge amount variation with respect to environmental changes from low temperature and low humidity to high temperature and high humidity, and to provide magenta toner, yellow toner, cyan toner and black. It is an object of the present invention to provide a color toner for electrostatic charge development which gives a clear transferred image quality which is extremely close to a natural color in so-called multi-color superposition using toners in combination.

[0006]

The present inventors have completed the present invention as a result of intensive studies to solve the above problems.

The present invention is a combination of four color toners for electrostatic image development capable of reproducing all colors of magenta toner, yellow toner, cyan toner and black toner, and the magenta toner is a colorant. Containing a naphthol-based organic pigment represented by the structural formula (1) as
The yellow toner contains a disazo organic pigment represented by the structural formula (2) as a colorant, the cyan toner contains a β-type copper phthalocyanine pigment and a polychlorocopper phthalocyanine pigment as a colorant, and the black toner is a colorant. As at least one selected from the group consisting of isoindolinone yellow pigment and tetrachloroisoindolinone yellow pigment, at least one selected from the group consisting of quinacridone red pigment and perylene red pigment, and phthalocyanine 4 containing a blue-based pigment
The present invention relates to a combination of color electrostatic image developing color toners.

[0008]

[Chemical 2]

Pigment Red 184 is preferable as the naphthol-based organic pigment represented by the structural formula (1) that can be used in the magenta toner according to the present invention.
Homannst Permanent as a commercial product
Rubine F-6B can be mentioned.

Pigment Yellow 17 is preferable as the disazo organic pigment represented by the structural formula (2) that can be used in the yellow toner according to the present invention.
As a commercial product, Dainippon Ink and Chemicals Co., Ltd.
Fast Yellow 8GF can be mentioned.

As a β-type copper phthalocyanine pigment that can be used in the cyan toner according to the present invention, C.I. I. Pigmen
t Blue 15: 3 is preferable, and as a commercial product, Fastogen Blue T manufactured by Dainippon Ink and Chemicals, Inc.
GR may be mentioned, and examples of the polychlorocopper phthalocyanine pigment include C.I. I. Pigment Blue 7 is preferable, and Fa manufactured by Dainippon Ink and Chemicals, Inc. is commercially available.
StogenGreen S can be mentioned. The content of the polychlorocopper phthalocyanine pigment is preferably 1 to 20 wt% with respect to the total pigment content of the β-type phthalocyanine pigment and the polychlorocopper phthalocyanine.

Examples of the isoindoline yellow pigment that can be used in the black toner according to the present invention include C.I. I. Pigm
ent Yellow 139 and 185 are preferable,
C. I. Pigment Yellow 139 is a commercially available product of BASF's Pliotol Yellow.
w L1820, and C.I. I. Pigm
BAS is a commercially available product of ent Yellow 185.
Silicone Yellow D1155 manufactured by Company F can be mentioned. Examples of the tetrachloroisoindoline yellow pigment that can be used in the black toner according to the present invention include C.I. I. Pigment 109, 110 are preferred, and C.I. I. As a commercially available product of Pigment 109, Irgazin Yellow manufactured by Ciba-Geigy
w 2GLTE, and C.I. I. Pigm
As a commercially available product of ent 110, Fastgen Yellow GRO manufactured by Dainippon Ink and Chemicals, Inc. can be mentioned. Examples of the quinacridone red pigment that can be used in the black toner according to the present invention include C.I. I. Pigme
nt Red 122 is preferable, and a commercially available product is Fastgen Super M manufactured by Dainippon Ink and Chemicals, Inc.
azenta R and HOECHST's Hostap
erm Pink E, and examples of the perylene red pigment include C.I. I. Pigment Red 1
49 is preferable, and a commercially available product is P manufactured by HOECHST
V FAST RED B can be mentioned. Examples of the phthalocyanine blue pigment that can be used in the black toner according to the present invention include C.I. I. Pigment Blue
15-1, 15-2, 15-3, 15-4 are preferable, and as a commercial product, KET manufactured by Dainippon Ink and Chemicals, Inc.
Blue 111 can be mentioned.

The magenta toner, the yellow toner, the cyan toner, and the black toner according to the present invention have a small variation in charge amount with respect to environmental changes from low temperature and low humidity to high temperature and high humidity, and give good and stable transfer images, and magenta. When a toner, a yellow toner, a cyan toner, and a black toner are used together to form a multicolor image, a clear multicolor image that is extremely close to the original multicolor image is formed.

As the binder resin used in magenta toner, yellow toner, cyan toner and black toner, polystyrene, styrene- (meth) acrylate copolymer, polyester, epoxy resin, butyral resin, xylene resin, Examples of the resin include malon indene resin. In full-color applications, the resin viscosity at the time of toner fixing is higher than that of black toner for general copying machines in order to satisfy full-color reproducibility, OHP translucency, and fixing strength. A low resin is desired, and specifically, polyester resin and epoxy resin are preferable.

However, the above polyester resins and epoxy resins have many hydrophilic groups such as carboxyl groups and hydroxyl groups in the molecule. Therefore, these resins are most commonly used in polystyrene and styrene-acrylic copolymers. Hygroscopicity tends to be higher than polymerized resins, and as a result,
The amount of charge easily fluctuates due to environmental changes. In order to avoid this, a vinyl-modified polyester obtained by graft-polymerizing a specific amount of an aromatic vinyl monomer and an amino group-containing vinyl monomer on an unsaturated polyester composed of at least an unsaturated aliphatic dibasic acid and a polyhydric alcohol is preferable.

That is, a vinyl-modified polyester resin obtained by graft-polymerizing a specific amount of an aromatic vinyl monomer and an amino-group-containing vinyl monomer onto an unsaturated polyester resin having many hydrophilic groups such as carboxyl groups and hydroxyl groups is graft-polymerized. The content of hydrophilic groups is lower than that of the previous unsaturated polyester resin, and the hygroscopicity is reduced. As a result, while maintaining good full-color reproducibility, OHP translucency, and appropriate fixing strength, which are the characteristics of the vinyl-modified polyester resin, the change in charge amount due to environmental changes is small. Also, the amino group-containing vinyl monomer is used for obtaining a stable charge amount of the toner, that is, when the content thereof is in the range of 0.1 to 2.0% by weight based on the whole vinyl modified polyester resin, The positive chargeability of the amino group is added to the negative chargeability of polyester,
The toner as a whole becomes uncharged or weakly positively charged,
Further, the combined use of the minus charge control agent brings about an advantage that a desired charge amount can be obtained.

Further, a preferable binder resin which can be used in the present invention is (1) a polyvalent carboxylic acid containing an aliphatic unsaturated dibasic acid in an amount of 0.2 to 2.0% by weight in a polyester resin. An acid and a diol having a propylidene diphenyl group in the molecule have a weight average molecular weight of 5,000.
70 to 10 parts by weight of a vinyl monomer containing (2) 50% by weight or more of an aromatic vinyl monomer and 1 to 30% by weight of an amino group-containing vinyl monomer, to 30 to 90 parts by weight of a polyester resin of 0 to 12,000. The weight average molecular weight obtained by polymerization is 8,000 to 20,000, 1
It is a graft polymer having a melt viscosity at 00 ° C of 10 ⁴ to 10 ⁶ poise and a glass transition temperature of 50 to 75 ° C.

Examples of the aliphatic unsaturated dibasic acid include maleic acid, maleic anhydride, fumaric acid, itaconic acid and citraconic acid. Other polycarboxylic acids include phthalic anhydride, terephthalic acid, isophthalic acid, orthophthalic acid, hexahydrophthalic anhydride, tetrahydrophthalic anhydride, cyclohexanedicarboxylic acid, succinic acid,
Examples thereof include dibasic acids such as malonic acid, glutaric acid, adipic acid, azelaic acid, sebacic acid, and alkyl or alkenylsuccinic acids having 4 to 18 carbon atoms.

Examples of the diol having a propylidene diphenyl group in the molecule include hydrogenated bisphenol A propylene oxide adducts and bisphenol A ethylene oxide adducts. The average addition mole number of propylene oxide and ethylene oxide in the above oxide adduct is suitably 2 to 7, and an adduct in which both propylene oxide and ethylene oxide are added can be used. Further, as a polyol component, a polyol other than the above-mentioned bisphenol type diol may be added as long as it is about 10 mol% or less in the total polyol component. Examples of such polyols include ethylene glycol, propylene glycol, neopentyl glycol, 3,3,5-trimethyl-2,4-pentanediol and the like.

In addition to the above components, it is preferable to use a trifunctional compound such as trimellitic anhydride, glycerin, and trimethylolpropane within the range in which the polyester resin does not gel. In addition, benzoic acid, para-tert-butylbenzoic acid, as a molecular weight regulator of polyester resin,
Monofunctional compounds such as cyclohexanol can also be used as appropriate. The weight average molecular weight of the polyester resin is 5,
A range of 000 to 12,000 is suitable. If the molecular weight of the resin is less than 5,000, the resin becomes too brittle and the durability as a toner deteriorates. On the other hand, if it exceeds 12,000 and becomes too large, gelation tends to occur during graft polymerization, and a suitable graft polymer cannot be obtained. Incidentally, among the components constituting the polyester resin, the aliphatic unsaturated dibasic acid is an important component in the sense that it serves as a graft active site and also introduces a partially crosslinked structure into the graft polymer.
If the amount of the aliphatic unsaturated dibasic acid is less than 0.2% by weight, it becomes difficult to carry out the graft polymerization, and if it exceeds 2% by weight, gelation tends to occur. Maleic anhydride is particularly suitable as the aliphatic unsaturated dibasic acid.

The polyester resin can be produced by polycondensing a carboxylic acid component and a diol component in an inert gas atmosphere at a temperature of 180 to 250 ° C. At this time, an esterification catalyst which is usually used for accelerating the reaction, such as zinc oxide, stannous oxide, dibutyltin oxide, dibutyltin dilaurate or the like, can be used. It can also be manufactured under reduced pressure for the same purpose. Polyester resin 30 thus obtained
The graft polymer is obtained by graft-polymerizing 70 to 10 parts by weight, preferably 50 to 10 parts by weight of a vinyl monomer with respect to 90 parts by weight, preferably 50 to 90 parts by weight. If the polyester resin is less than 30 parts by weight,
A toner exhibiting good fixability and leveling (surface activity), which is the object of the present invention, cannot be obtained. On the other hand, when the polyester resin exceeds 90 parts by weight, the negative chargeability of the polyester is strong, and it is difficult to control the toner having the vinyl-modified polyester resin and the colorant as the main components to an appropriate charge amount with the negative charge control agent.

Examples of the amino group-containing vinyl monomer which is an essential component of the vinyl monomer include methacrylic acid dimethylaminoethyl ester, methacrylic acid diethylaminoethyl ester, acrylic acid dimethylaminoethyl ester and dimethylaminopropyl methacrylamide. The amount of the amino group-containing vinyl monomer is 1 to 30% by weight, preferably 1 to 30% by weight in the vinyl monomer.
It is 20% by weight. If the amount of the amino group-containing vinyl monomer is less than 1% by weight in the vinyl monomer, the vinyl-modified polyester resin as a whole becomes negatively charged, and as described above, it becomes difficult to adjust the amount of charge by the negative charge control agent.
On the other hand, if the amount exceeds 30% by weight, the positive charging property is too strong, which makes it difficult to make the entire toner negative charging property.

Examples of the aromatic vinyl monomer which is an essential component of the vinyl monomer include styrene, α-methylstyrene, vinyltoluene and p-ethylstyrene. Other vinyl monomers include alkyl methacrylates such as methyl methacrylate, butyl methacrylate, octyl methacrylate, stearyl methacrylate, etc .; alkyl acrylates such as ethyl acrylate, propyl acrylate, butyl acrylate, octyl acrylate, etc. Esters; acrylonitrile, acrylamide and the like can be mentioned.

The graft polymerization reaction is carried out by solution polymerization or suspension polymerization. In the case of the solution polymerization method, a vinyl monomer and a polymerization initiator are added to a polyester resin dissolved in a solvent such as xylene and toluene, and polymerization is carried out at a temperature of 60 to 150 ° C. in an inert gas atmosphere. Further, in the case of suspension polymerization, a polyester resin and a polymerization initiator are dissolved in a vinyl monomer, suspended and dispersed in water containing a suspension stabilizer and polymerized in the same manner. Suitable polymerization initiators are azo-based initiators such as azobisisobutyronitrile and azobisdimethylvaleronitrile.

The weight average molecular weight of the graft polymer is 8,
000 to 20,000 is suitable, and if necessary, a chain transfer agent such as dodecyl mercaptan or thiophenol can be used. When the weight average molecular weight of such a polymer is less than 8,000, the binder resin becomes too brittle and the durability as a toner is poor,
On the other hand, when it exceeds 20,000, a toner composition which brings about a good fixing property and leveling, which is the object of the present invention, cannot be obtained.

The glass transition temperature of the graft polymer by differential thermal analysis is preferably 50 to 75 ° C, more preferably 5
5 to 70 ° C is suitable. If the glass transition temperature is too low, the toner tends to be blocked, and if it is too high, the fixability is deteriorated. The glass transition temperature represents an endothermic peak temperature in differential thermal analysis.

The melt viscosity of the graft polymer as measured by the flow tester method is 10 ⁴ to 10 ⁶ poise at 100 ° C., preferably 5 × 10 ^{4 to} 5 × 10 ⁵ poise. If the melt viscosity is too low, the offset resistance becomes poor,
On the other hand, if it is too high, when it is used for OHP, the level of the toner layer fixed on the OHP sheet is poor, and the transmitted light is scattered, resulting in a darkened, low-saturation light transmission image.

Various charge control agents can be used in the toner of the present invention, and typical examples thereof include a quaternary ammonium salt complex and a salicylic acid metal complex. Further, to the toner of the present invention, fine powder of oxide such as arsenic, titanium, and aluminum or fine powder of aliphatic metal salt which has been subjected to a hydrophobic treatment for the purpose of improving fluidity and cleaning property of the toner is added. You can also do it.

To produce the toner according to the present invention, a binder resin, a colorant, a charge control agent, a fluidity improver and the like are well mixed in advance by a ball mill or the like, and then sufficiently melted and kneaded in various kneaders and cooled. After that, finely pulverize with a jet mill or the like, and classify to a required particle size.

[0030]

EXAMPLES Examples of the present invention will be described below. In addition, "part" in a compounding quantity is a weight standard. Resin Production Example 2-2'-bis [p- (2-hydroxyethoxy) -phenyl] propane 64 parts, isophthalic acid 16 parts, terephthalic acid 16 parts, maleic anhydride 0.6 parts, dibutyltin oxide 0.06 parts Charge the flask into a flask, and under a nitrogen atmosphere,
The reaction was continued at 30 ° C. for 24 hours. The weight average molecular weight of the obtained polyester resin was 7,600. This polyester resin is hereinafter referred to as "resin A".

50 parts of this polyester resin and 50 parts of xylene were charged into a flask and dissolved. Increase the temperature until the xylene is refluxed, and add 13 parts of styrene under xylene reflux.
A solution prepared by dissolving 0.4 part of azobisisobutyronitrile in 0.3 part of diethylaminoethyl methacrylate was added dropwise in about 30 minutes under a nitrogen atmosphere. After the dropping, the temperature was kept for 3 hours, the xylol was distilled under reduced pressure, and the resin was taken out. This vinyl-modified polyester resin is hereinafter referred to as "resin B". Resin B had a weight average molecular weight of 12,000, a melt viscosity at 100 ° C. of 5 × 10 ⁴ poises, and a glass transition temperature of 62 ° C. However, the melt viscosity is Flow Tester C made by Shimadzu Corporation.
Nozzle diameter 1mm, nozzle length 1m using FT-500
m, load 30 kg, temperature rising rate 3 ° C./min.

Example 1 95 parts of the resin B, Permanent Ruby
F-6B (Hoechst) 3 parts, Bontron E-84
3 parts (manufactured by Orient Chemical Co., Ltd.) are mixed by a ball mill and melt-kneaded by a hot roll. After cooling, the mixture was finely pulverized with a jet mill and further classified to obtain a magenta toner (1) having an average particle diameter of 11 μm. Toner (1) 4 parts and carrier (Ferrite carrier F-15 manufactured by Powder Tech Co., Ltd.)
0) 96 parts by friction were mixed to prepare a developer (1).

Example 2 Instead of F-6B, SYMLER FAST YEL
Yellow toner (2) and developer (2) were obtained in the same manner as in Example 1 except that low 8GF (manufactured by Dainippon Ink and Chemicals, Inc.) was used.

Example 3 Fastogen Blue instead of F-6B3 part
2.82 parts of TGR (manufactured by Dainippon Ink and Chemicals, Inc.) and Fa
stogen Green S (manufactured by Dainippon Ink and Chemicals)
A cyan toner (3) and a developer (3) were obtained in the same manner as in Example 1 except that 0.18 part was used.

Example 4 Fastogen Super instead of F-6B3 part
Yellow GRO (isoindolinone yellow pigment manufactured by Dainippon Ink and Chemicals, Inc.) 2 parts, PVFAST RED
B (5 parts by Hoechst perylene red pigment), Fas
Black toner (4) and developer (4) were obtained in the same manner as in Example 1 except that 3.5 parts of Togen Blue TGR (phthalocyanine blue pigment manufactured by Dainippon Ink and Chemicals, Inc.) was used.

Example 5 For each of the developers obtained in Examples 1 to 4,
High temperature and high humidity (40 ° C, 90% RH), normal temperature and normal humidity (20 ° C,
50% RH), low temperature and low humidity (10 ° C., 20% RH), left for 1 hour each in different environments, then immediately measure the charge amount of each developer, charge amount against changes in environmental conditions of developer left The changes were evaluated. The results are shown in Table 1. A blow-off charge amount measuring device manufactured by Toshiba Chemical Co. was used for measuring the charge amount.

Example 6 A reproduction machine BD-3504 manufactured by Toshiba Corp. was used, and magenta toner (1), yellow toner (2) and cyan toner (3) were used.
And a full color original was copied using black toner (4). As a result, a natural color image very close to the original was obtained.

Example 7 Examples 1 and 2 except that Resin A was used in place of Resin B,
Magenta toner (1 '), yellow toner (2'), cyan toner (3 '), and black toner (4') were prepared in the same manner as 3 and 4. As a result of copying a full-color original in the same manner as in Example 6, a natural color image very close to the original was obtained.

Example 7 Example 1 was repeated except that Epiclon 4050 (epoxy resin manufactured by Dainippon Ink and Chemicals, Inc.) was used instead of Resin B.
Magenta toner (1 ″), yellow toner (2 ″), cyan toner (3 ″), and black toner (4 ″) were prepared in the same manner as 2, 3, and 4. As a result of copying a full-color original in the same manner as in Example 6, a natural color image very close to the original was obtained.

[0040]

[Table 1]

[0041]

The developer using the magenta toner, the yellow toner, the cyan toner and the black toner of the present invention has a small change in the charge amount value with respect to the change in the environmental condition from the low temperature and low humidity to the high temperature and high humidity, and various It is possible to obtain stable transfer image performance even under the use environment. Moreover, the combination of the color toners of the present invention is excellent in the reproducibility of the natural color image and can provide a very high quality full color image.

Claims (5)

[Claims] 1. A magenta toner as a colorant in a combination of four color electrostatic image developing color toners capable of reproducing all colors of magenta toner, yellow toner, cyan toner and black toner. The naphthol organic pigment represented by the formula (1) is contained, the yellow toner contains the disazo organic pigment represented by the structural formula (2) as a colorant, and the cyan toner contains the β-type copper phthalocyanine pigment as the colorant. And a polychlorocopper phthalocyanine pigment, and at least one selected from the group consisting of an isoindolinone yellow pigment and a tetrachloroisoindolinone yellow pigment as a colorant for a black toner, a quinacridone red pigment and perylene. At least one selected from the group consisting of a red pigment and a phthalocyanine blue pigment. 4-color combination of a color toner for developing electrostatic latent images which is characterized in that. [Chemical 1] 2. The magenta toner colorant is C.I. I. Pi
The full color toner combination of claim 1 which is gment Red 184. 3. The yellow toner colorant is C.I. I. Pi
The combination of full color toners of claim 1 which is gment Yellow 17. 4. The cyan toner colorant is C.I. I. Pig
ment Blue 15: 3 and C.I. I. Pigment
The full color toner combination of claim 1 which is Blue 7. 5. The full-color toner combination according to claim 1, which contains a vinyl-modified polyester obtained by graft-polymerizing an aromatic vinyl monomer and an amino group-containing vinyl monomer on an unsaturated polyester as a binder resin.