JPH0296182A - Electrophotographic cyan toner - Google Patents

Abstract

PURPOSE:To obtain an electrophotographic cyan toner having improved chargeability, spectral reflection characteristics, and color miscibility by incorporating a specified compd. as charge controlling agent and a copper phthalocyanine pigment as coloring pigment into a binder resin for the toner. CONSTITUTION:C.I. Solvent Blue 14 and a compd. classified into copper phthablocyanine pigment both of which are dissolved satisfactorily in a binder resin for toner as constituting components of an electrophotographic toner are used in combination. Both components are melted and kneaded, and granulated. Thus, a distribution of the charge controlling component in individual fine toner particles prepd. thereby is made unform, and uneveness of charge is not resulted. Thus, an electrophotographic cyan toner haivng uniform chargeability as well as superior spectral reflection characteristics, and high color miscibility, is obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to a color toner for electrophotography, and more particularly to a cyan toner for electrophotography that provides a clear colored image.

(Prior Art) Conventionally, in a copying machine using an electrophotographic method, an electrostatic latent image formed on a photoreceptor having a photosensitive layer containing an inorganic or organic photoconductive substance is visualized by a dry developing method. Various powder toners containing colorants, binder resins, etc. are used.

In the electrophotographic method, an electrostatic latent image formed on the photoreceptor by charging and exposure to light is developed with the toner, and a toner image formed corresponding to the electrostatic latent image is transferred to a support such as transfer paper. At the same time as the transfer, the toner image is fixed on the support by a fixing means such as a heating roller or a pressure roller, thereby making the electrostatic latent image visible. Further, after the toner image is transferred to the support, the residual toner on the photoreceptor is removed by a cleaning blade in order to clean the toner remaining on the photoreceptor.

Currently, a black toner whose main components are a black pigment and a fixing binder resin is generally used as the toner.
Furthermore, various color toners are manufactured by using chromatic pigments as pigments. The color toner, like the black toner, must have excellent charging properties, and a method that utilizes frictional charging of a resin, which is a component of the toner, has been known as a method for imparting an electric charge to the toner during the development. ing. However, in such a method, since the amount of charge of the toner is small, C, I, Solvent Red 177 (Japanese Patent Application Laid-open No. 58118654), 1-(2-hydroxy 3, 5-') nitrophenyl a'/' )-3-phenylcarbamoyl-2-naphthol 1:A charge control agent composed of dyes and pigments such as type 2 chromium complex salts, naphthenic acid metal salts, and fatty acid metal soaps is added to the toner as an additive that imparts chargeability. Something has been proposed.

On the other hand, as properties specific to the color toner, it is necessary to have excellent spectral reflection characteristics and color mixing properties, and conventionally C.
01, Pigment Red48 and C, 1, Pi
Toner containing gment-Red81 (Japanese Unexamined Patent Application Publication No. 62
As shown in Japanese Patent Publication No. 49359), various types of materials using limited materials such as coloring agents have been proposed.

(Problems to be Solved by the Invention) However, many of the dyes and pigments conventionally used as charge control agents have low compatibility with resins, and all require dispersion in a binder resin. There were problems with the dispersion method, stability of the dispersion, etc.

That is, it is difficult to uniformly disperse insoluble pigments and dyes with low compatibility in the binder resin, which complicates the dispersion process. Moreover, due to the low compatibility with the resin, the components in the individual toner particles manufactured become non-uniform, and the charge imparted to the toner varies. Large or small particles may be formed, and in some cases, fine particles consisting only of dyes or pigments may also be present.

As a result, the image obtained by development may become foggy and unclear, or even if it shows good developability at the beginning of use, the developing ability may deteriorate with continued use, or the copying may become difficult due to increased toner scattering. There were problems such as contamination inside the aircraft.

Furthermore, since pigments are aggregates, differences in the conditions of the pigment manufacturing process greatly affect the characteristics of the manufactured toner, and it is extremely difficult to control the physical properties of pigments to solve this problem.

In addition, in color toners, the color of the charge control agent itself greatly affects the color mixing properties, spectral reflection characteristics, etc. of the toner even when the amount contained in the toner is small. Therefore, there is a continuing need for a suitable combination of color pigments and charge control agents, which are constituent components of color toners, with respect to the hue of the toner.

Therefore, an object of the present invention is to solve the above-mentioned drawbacks of conventional electrophotographic toners, and to provide electrophotographic toners that are uniformly charged, have excellent charging ability, and have good spectral reflection characteristics and color mixing properties. The purpose is to provide cyan toner.

(Means and effects for solving the problems) The present invention has the following features:
The above object was achieved by configuring a cyan toner for electrophotography containing a compound classified as C, 1, Solvent Blue 14 as a charge control agent in a binder resin for toner, and a copper phthalocyanine pigment as a coloring pigment. .

As a result of intensive research, the inventors of the present invention discovered that the oil-soluble dyes classified as C, I, and Solvent Blue 14 dissolve extremely well in the binder resin for toners, and that the oil-soluble dyes classified as copper phthalocyanine pigments dissolve extremely well in the binder resin for toner. It was discovered that the compound gives a clear cyan color with extremely good spectral reflection characteristics.

Furthermore, as a result of intensive research, it was found that c
It has been discovered that by combining Solvent Blue 14 with a compound classified as a copper phthalocyanine pigment, a clear cyan toner with particularly excellent color mixing properties can be obtained.

Therefore, since the cyan toner for electrophotography of the present invention uses the above-mentioned components, the charge control agent component in each fine toner particle produced by melt-kneading and granulating the same becomes uniform. As a result, it is possible to obtain a cyan toner for electrophotography which has extremely uniform charging properties without uneven charging, and also has good spectral reflectivity and color mixing properties.

In addition, 20C, 1, Solvent Blue 14 shows little change in moisture absorption even when the humidity is changed, and the relationship between the moisture absorption conditions and the moisture content is as follows for C11, Solvent Blue 14.
Blue 14 (Number - Moisture per strip Moisture content 1%) 20°C 260% RHO, 0255 35°C 185% RHO, 4943 It can be seen that the moisture content in the dye has very little dependence on humidity. This means that toners using the above-mentioned oil-soluble dyes have little variation in moisture content that affects the properties of the toner, regardless of changes in atmospheric humidity, temperature, etc., and in other words, this toner does not tend to deteriorate over time. This means that stable development characteristics can be obtained.

Furthermore, the amount of charge of C0I, Solvent Blue 14 is,
For example, when measured by blow-off after mixing with a ferrite carrier, the following C,1, Solvent Blue 14 was on the order of about -14,1 μc/g, indicating that the above compound functions satisfactorily as a charge control agent.

(Preferred Embodiment of the Invention) As the toner binder which is a component of the present invention, a wide variety of binders including those known in the art can be used, and examples thereof include polystyrene, chloropolystyrene, poly-α-methylstyrene, styrene- Chlorostyrene copolymer, styrene-propylene copolymer, styrene-butadiene copolymer, styrene-vinyl chloride copolymer, styrene-vinyl acetate copolymer, styrene-maleic acid copolymer, styrene-acrylic acid ester copolymer Polymers, (styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer, styrene-butyl acrylate copolymer, styrene-
octyl acrylate copolymer, styrene-phenyl acrylate copolymer, etc.), styrene-methacrylate ester copolymer (styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, styrene-butyl methacrylate) copolymers, styrene-octyl methacrylate copolymers, styrene-phenyl methacrylate copolymers, etc.), styrene-α-methyl chloroacrylate copolymers, styrene-acrylonitrile-acrylic acid ester copolymers, etc. Resin (unipolymer or copolymer containing styrene or styrene substitute), vinyl chloride resin, styrene-vinyl acetate copolymer, methacrylate-acrylate copolymer, rosin-modified maleic acid resin, phenol resin, epoxy resin, polyester There are resins, low molecular weight polyethylene, low molecular weight polypropylene, ionomer resins, polyurethane resins, silicone resins, ketone resins, ethylene-ethyl acrylate copolymers, xylene resins, polyvinyl butyral resins, etc., but particularly preferred resins for carrying out this invention are is polyester resin,
Examples include styrene-acrylic resin, acrylic resin, and the like.

Any polyester resin can be used as the above polyester resin, but from the viewpoint of non-offset property and fixing property, the following polyester resin: H3 (wherein R is an ethylene group or a propylene group, m
and n is a positive integer) and a polyhydric carboxylic acid, its acid anhydride, or its derivative as an acid component. .

The diol component represented by the above-mentioned shipman includes polyoxypropylene-2,2-bis(4-hydroxyphenyl)propane, polyoxyethylene-2,2-bis(4-hydroxyphenyl)propane, and polyoxypropylene-2,2-bis(4-hydroxyphenyl)propane.
Examples include polyoxyethylene-2,2-bis(4-hydroxyphenyl)propane.

Carboxylic acid components include maleic acid, fumaric acid, mesaconic acid, citraconic acid, itaconic acid, glutaconic acid, phthalic acid, isophthalic acid, terephthalic acid, cyclohexanedicarboxylic acid, succinic acid, adipic acid, sepacic acid, malonic acid, Riluic acid, 1,2.4 benzenetricarboxylic acid, 1.2.5 benzenetricarboxylic acid, 1,
2.4 cyclohexanetricarboxylic acid, 2.5.7 naphthalenetricarboxylic acid, 1,2.4 naphthalenetricarboxylic acid, 1,2.5 hexanetricarboxylic acid, 1,2.
4-butanetricarboxylic acid, 1,3-dicarboxy-2-methylcarboxypropane, 1,3-dicarboxy-2-
Mention may be made of methyl-2-methylcarboxypropanetetra(methylenecarboxy)methane, 1,2,7.8 octanetetracarboxylic acid, embol trimer, and acid anhydrides thereof.

Conophoryester resin is produced by condensation polymerization of the diol component and polyhydric carboxylic acid component,
At this time, the number of carboxyl groups in the carboxylic acid component is 1.2 to 0.0 relative to the number of hydroxyl groups in the diol component.
8, particularly preferably from 1.1 to 0.9,
Further, as the catalyst, tin oxide, zinc oxide, titanium oxide, dibutyltin oxide, dibutyltin diurarate, etc. are used. Furthermore, in addition to the etherified bisphenol shown in the above-mentioned ``Shipin'', other diol components such as ethylene glycol and bisphenol A can be used in combination within a range of 10 mol%.

Any styrene-acrylic resin can be used, but from the viewpoint of anti-blocking properties, fixing properties, and development properties, (i) styrene, (ii) acrylic ester or methacrylic ester, and (iii) ethylene A styrene-acrylic resin containing an unsaturated carboxylic acid or its anhydride as a constituent monomer and having an acid value in the range of 0.2 to 30 is preferred. As a styrenic monomer,
Represented by the following formula (wherein R1 is a hydrogen atom, a lower alkyl group, or a halogen atom, R2 is a substituent such as a lower alkyl group or a halogen atom, and n is an integer of 2 or less including O) Examples of such monomers include styrene, vinyltoluene, α-chlorostyrene, vinylxylene, and vinylnaphthalene. Among these, styrene is preferred.

As the acrylic monomer which is another component, CH,=C -0-R4 〇 (wherein R3 is a hydrogen atom or a lower alkyl group,
R4 is an alkyl group having up to 18 carbon atoms), such as ethyl acrylate, methyl methacrylate, butyl acrylate, butyl methacrylate, 2-
Examples include ethylhexyl acrylate and 2-ethylhexyl methacrylate.

On the other hand, examples of ethylenically unsaturated carboxylic acids or anhydrides thereof that give the styrene-acrylic resin an acid value in the above-mentioned range include acrylic acid, methacrylic acid, crotonic acid, fumaric acid, maleic acid, maleic anhydride, and itaconic acid. , itaconic anhydride, tetrahydrophthalic anhydride, and the like.

As the acrylic resin, any resin can be used, but a methacrylate-acrylate copolymer is exemplified from the viewpoint of transparency that is effective in electrophotographic color toners and the like. The main monomer components of this methacrylate-acrylate copolymer are methacrylic esters such as methyl methacrylate (MMA), ethyl methacrylate, and butyl methacrylate, and acrylic esters such as methyl acrylate, ethyl acrylate, and butyl acrylate. , if desired, is a copolymer containing a small amount of an ethylenically unsaturated carboxylic acid such as acrylic acid, methacrylic acid, crotonic acid, fumaric acid, maleic anhydride, itaconic acid, or an anhydride thereof as a copolymerization component.

The copolymerization ratio of methacrylate and acrylate can be varied within a range that satisfies transparency, refractive index, melting properties, melt leveling properties, etc., but generally the former is 60%
95% by weight, especially 70% to 90% by weight, the latter being 5% by weight.
A range of from 10 to 30% by weight is preferred, particularly from 10 to 30% by weight. As the methacrylate, methyl methacrylate (MMA) is most suitable in terms of economy and transparency.
Ethyl acrylate (EA) is most suitable as the acrylate in terms of melt leveling properties.

(The following is a blank space) As the copper phthalocyanine pigment which is a constituent component of the present invention, any one can be used, but for example, in the following - Shipman formula, R1 to R4 are the same or different and are represented by a hydrogen atom, and R5 and R5 are Represents an alkylene group having 1 to 5 carbon atoms.

The above-mentioned coloring pigments, including the copper phthalocyanine pigment represented by the formula, are used in an amount of 1 to 15 parts by weight per 100 parts by weight of the toner binder resin. If the amount is less than the above range, the color tone of the cyan toner will not be maintained, and if the amount is more than the above range, the chargeability will be seriously affected, which is not preferable.

In the present invention, C is used as a charge control agent together with a color pigment.
01, Solvent Blue 14 is preferably used in an amount of 0.5 to 10% by weight, especially 1 to 5% by weight, based on the binder resin for toner.If it is less than the above range, there is no charge control effect; When the amount exceeds the above range, the stability of the toner deteriorates and problems such as carrier contamination occur.

In the electrophotographic toner of the present invention, toner compounding agents known per se can be blended according to known formulations.

The toner is manufactured by blending a predetermined amount of the above-mentioned composition, melting and kneading it in a roll mill, and granulating the mixture. For molding, the above-mentioned kneaded composition is cooled, then coarsely pulverized with a hammer mill, and further finely pulverized with a jet mill. Of course, mechanical stirring or rapid stirring may be used to round off irregularly shaped particles. The particle size of the toner particles may be related to resolution, etc., but is generally preferably within the range of 5 to 35 microns.

(Effects of the Invention) The toner of the present invention has C9I and Solvent Blue 14, which are extremely compatible with the toner binder resin.
The toner is uniformly charged, and has stable charging properties even after repeated development through continuous use.Furthermore, by combining copper phthalocyanine pigments as coloring pigments, it has good spectral reflection characteristics and color mixing properties. Able to maintain clear images.

(Example) Hereinafter, the present invention will be explained in Examples.

100 parts by weight of polyester resin as a binder, 8.5 parts by weight of copper phthalocyanine pigment (product name: Cyanine Blue FBK, manufactured by Dezumi Shiki), as a charge control agent, C, R, Solvent Blue. 14 (manufactured by Hodogaya Chemical Industry Co., Ltd., product name SOT BLUE2)
A mixture of 2 parts by weight of the above toner materials is melt-kneaded, cooled, pulverized, and further classified to produce the toner of the present invention, and further 5 parts by weight of the above toner and a carrier (manufactured by Nippon Tetsuko Co., Ltd., trade name 5FC150) 95 A developer sample was prepared by mixing parts by weight.

Example 1 A developer sample was produced in the same manner as in Example 1, except that a styrene-acrylic copolymer was used as the binder resin in place of the polyester resin used in Example 1.

Example 1 except that the polyester resin used in Example 1 was replaced with an MMA+EA copolymer as the actual flame-working binder resin.
A developer sample was produced in the same manner.

Comparison top C and I used in Example 1 as charge control agents.

C, I in place of Solvent Blue 14 (manufactured by Hodogaya Chemical Industry Co., Ltd., trade name SOT BLUE2).

Solvent Blue 8 (manufactured by Hodogaya Chemical Industry Co., Ltd., product name S
A developer sample was produced in the same manner as in Example 1 except that OT BLUEI) was used.

comparison lieutenant C8I used in Example 2 as a charge control agent.

C0I instead of Solvent Blue 14 (manufactured by Hodogaya Chemical Industry Co., Ltd., trade name SOT BLUE2).

Solvent Blue 8 (manufactured by Hodogaya Chemical Industry Co., Ltd., product name S
A developer sample was produced in the same manner as in Example 2 except that OT BLtJEl) was used.

comparative officer C0I used in Example 3 as a charge control agent.

C, I in place of Solvent Blue 14 (manufactured by Hodogaya Chemical Industry Co., Ltd., trade name SOT BLUE2).

Solvent Blue 8 (manufactured by Hodogaya Chemical Industry Co., Ltd., product name S
A developer sample was produced in the same manner as in Example 3, except that OT BLUEI) was used.

Hokkaido±Sat C and I used in Example 1 as charge control agents.

C, I in place of Solvent Blue 14 (manufactured by Hodogaya Chemical Industry Co., Ltd., trade name SOT BLUE2).

A developer sample was produced in the same manner as in Example 1 except that Solvent Blue 67 (manufactured by Hodogaya Chemical Industry Co., Ltd., trade name 5PILON BLUE GNH) was used.

Comparison i C and I used in Example 2 as charge control agents.

C0T instead of Solvent Blue 14 (manufactured by Hodogaya Chemical Industry Co., Ltd., trade name SOT BLUE2).

A developer sample was produced in the same manner as in Example 2 except that Solvent Blue 67 (manufactured by Hodogaya Chemical Industry Co., Ltd., trade name 5PILON BLUE GNH) was used.

Beibian charcoal■ C8I used in Example 3 as a charge control agent.

C, I in place of Solvent Blue 14 (manufactured by Hodogaya Chemical Industry Co., Ltd., trade name SOT BLIJE2).

A developer sample was produced in the same manner as in Example 3, except that Solvent Blue 67 (manufactured by Hodogaya Chemical Industry Co., Ltd., trade name 5PILON BLUE GNH) was used.

Hokki Plate 1 Instead of the copper phthalocyanine pigment used in Example 1 as a colorant, C,1,Pigment-B1ue60 (
A developer sample was produced in the same manner as in Example 1 except that a thread-based pigment) was used.

Comparative development ■ Instead of the copper phthalocyanine pigment used in Example 2 as a colorant, C01, Pigment-B1ue60 (
A developer sample was produced in the same manner as in Example 2 except that a thread-based pigment) was used.

Comparison ■ Instead of the copper phthalocyanine pigment used in Example 3 as a colorant, C,1,Pigment-BIue60 (
A developer sample was produced in the same manner as in Example 3, except that a threne-based pigment) was used.

Each developer obtained in the above example was used in a copying machine manufactured by Sandako Co., Ltd.
-Continuously copied 20,000 sheets in A2 paper. the result,
When the developers of Examples 1 to 3 were used, yellow images with very good spectral reflection characteristics without fog were obtained, with almost no image deterioration and almost no toner scattering through 20,000 sheets. Ta. On the other hand, when the developers of Comparative Examples 1 to 6 were used, significant fogging occurred and clear images could not be obtained.

Further, when the developers of Comparative Examples 7 to 9 were used, the color tone was dull and the copy quality was dull.

Table 1 shows the types of dyes and binder resins used in the experiment and the results of measuring their solubility.

Table 1

Claims (2)

[Claims] (1) C.I. as a charge control agent in a binder resin for toner. I.
A cyan toner for electrophotography characterized by containing a compound classified as Solvent Blue 14 and a copper phthalocyanine pigment as a coloring pigment. (2) The cyan toner for electrophotography according to claim 1, wherein the toner binder resin is a polyester resin, a styrene-acrylic resin, or an acrylic resin.