JPH0339972A - Yellow toner - Google Patents

Abstract

PURPOSE:To enhance spectral reflection characteristics and transparency by incorporating in 100pts.wt. of a thermoplastic resin 0.1 - 20pts.wt. of a colorant composed essentially of a compound classified into C.I.Pigment Yellow 95. CONSTITUTION:The colorant to be used is composed essentially of a compound (yellow pigment) classified to C.I. Pigment Yellow 95 in Color Index Third Edition and 0.1 - 20pts.wt. of it is used per 100pts.wt. of the thermoplastic resin, thus permitting spectral reflection characteristics to be enhanced, a clear yellow image free from background fogging and uneven color to be obtained, deterioration of image quality due to successive copying not to occur, transparency to be good, and light resistance to be also enhanced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a yellow toner used in color electrophotography.

[Prior art and problems to be solved by the invention] Conventional electrophotographic methods include U.S. Pat.
Various methods are described in the above publications, but in general, a photoconductive substance is used to form an electrical latent image on a photoreceptor by various means, and then the latent image is developed with toner. If necessary, a method is used in which the toner image is transferred to paper or the like and then fixed by heating, pressure, solvent vapor, or the like.

In addition, in order to obtain a multicolor image, the original is exposed using a color separation filter, and the above process is repeated multiple times using color toners such as yellow, magenta, and cyan, and the toner images are superimposed to form a color image. It is something. Such color toners are required to have various characteristics, such as excellent chargeability, low environmental dependence, and low deterioration with repeated and continuous use, just like black toner for black and white copying. On the other hand, as characteristics unique to color toners, the toner must have good spectral reflection characteristics, high transparency, and excellent light resistance as essential properties. Therefore, the selection of the colorant to be used becomes extremely important.

Conventionally, as a coloring agent for yellow toner, JP-A-49-91
Dyes and pigments such as those described in Japanese Patent Publication No. 232 and Japanese Patent Publication No. 5B-42462 have been proposed, but none of these dyes and pigments has been able to satisfy all of the above characteristics, especially in yellow. Currently, there is a constant demand for improvements in color toner systems.

The present invention is an attempt to solve the problems of the prior art, and the main object of the present invention is to provide a yellow toner that has good spectral reflection characteristics and transparency, and has excellent light resistance. .

Another object of the present invention is to provide a yellow toner having excellent properties such as chargeability and durability.

[Means to solve the problem]

The present inventors conducted intensive studies to solve the above-mentioned problems, and found that in a color toner consisting of a thermoplastic resin and a colorant, C9■ and Pigment Yellow 9 were used as the colorant.
The present invention has been completed based on the discovery that a yellow toner using a compound (yellow pigment) classified as Class 5 as a main component satisfies all of the above characteristics.

That is, the present invention provides a color toner consisting of a thermoplastic resin and a colorant, in which the colorant is a compound classified as C01, Pigment Yellow 95 as a main component, and the colorant is added to 100 parts by weight of the thermoplastic resin. The present invention provides a yellow toner for electrostatic development characterized by containing 0.1 to 20 parts by weight.

The yellow pigment used in the present invention has a color index (
Color Index Th1rd Edition
n), c, r, Pigment Yellow 95 (C, 1
, Pigment Yellow 95), specifically Chromofine Yellow 5.
900 (manufactured by Dainichiseika Chemical Co., Ltd.), Yellow 157 (manufactured by Kanmoto Chemical Co., Ltd.), Chromophthal Yellow GR (C4ba-Gei
This refers to a group of compounds exemplified by products such as (manufactured by gy). These pigments have excellent solubility and compatibility with thermoplastic resins and exhibit good spectral reflection characteristics.

C, 1, pigment yellow 9 in the yellow toner of the present invention
The content of the coloring agent whose main component is a compound classified as No. 5 is in the range of 0.1 to 20 parts by weight, more preferably 0.2 to 10 parts by weight, based on 100 parts by weight of the thermoplastic resin.

If it is less than 0.1 part by weight, the coloring power of the toner is insufficient;
This is not sufficient for the purposes of the present invention. On the other hand, if the amount exceeds 20 parts by weight, the transparency becomes unsatisfactory.

In the present invention, known dyes and pigments can be used as the coloring agent mixed with C, R, Pigment Yellow 95 within a range that does not deteriorate the performance of C, R, Pigment Yellow 95. For example, C11Disp
erse Yellow 3, C, 1, mouth 1sper
seYelloiv 22, C, 1, Pigment
Yellow 12, (:, 1.PigmentYe
low 13, C, r, Pigment Yellow
w 14, C, 1, Pigment Yellow 17
,C,r,5olvent Yellow 30,C,
1,SolvenLYellow 77,C,1,5o
lvent Yellow 94, C01, 5olve
Examples include ntYe ow 162.

In the present invention, a wide range of thermoplastic resins can be used as the toner thermoplastic resin, including known ones, such as polystyrene, chloropolystyrene, poly-α-methylstyrene, styrene-chlorostyrene copolymer, and styrene-chlorostyrene copolymer.
Propylene copolymer, styrene-butadiene copolymer,
Styrene-vinyl chloride copolymer, styrene-vinyl acetate copolymer, styrene-maleic acid copolymer, styrene-
Acrylic ester copolymer (styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer,
Styrene-butyl acrylate copolymer, styrene-octyl acrylate copolymer, styrene-phenyl acrylate copolymer, etc.), styrene-methacrylate copolymer (styrene-methyl methacrylate copolymer, styrene-methacrylate copolymer, etc.) ethyl copolymer, styrene-butyl methacrylate copolymer, styrene-phenyl methacrylate copolymer, etc.), styrene-α-methyl chloroacrylate copolymer, styrene-acrylonitrile-acrylic ester copolymer, etc. Styrenic resins (monopolymers or copolymers containing styrene or styrene substitutes), vinyl chloride resins, rosin-modified maleic acid resins, phenolic resins, epoxy resins, polyester resins, low molecular weight polyethylene,
There are low molecular weight polypropylene, ionomer resin, polyurethane resin, silicone resin, ketone resin, ethylene-ethyl acrylate copolymer, xylene resin, polyvinyl butyral resin, etc., but particularly preferred resins for the practical use of the present invention are styrene resin and polyester. Examples include resin and epoxy resin. Moreover, the above resins are not limited to being used alone, but can also be used in combination of two or more.

The charge control of the toner may be performed using the thermoplastic resin and/or the colorant itself, but if necessary, a charge control agent that does not cause problems in color reproduction may be used in combination. In the case of positive charge control agents, quaternary ammonium salts, other basic,
Electron-donating organic substances can be used, and in the case of negative charge control agents, metal chelates such as alloy dyes, acidic or electron-withdrawing organic substances, etc. can be used. In addition, inorganic particles such as metal oxides or inorganic substances whose surfaces have been treated with the above-mentioned organic substances may be used.These charge control agents may be mixed and added to the toner thermoplastic resin, or they may be added to the toner particle surface. When performing charging control with the thermoplastic resin component itself, which may be used in an attached form, when imparting positive chargeability, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate, 2-vinylpyridine,
A thermoplastic resin containing an electron-donating monomer component such as 4-vinylpyridine can be used. When using the above-mentioned monomer components, the amine portion may be filled with quaternary ammonium, and when imparting negative chargeability to the thermoplastic resin component, methacrylic acid, acrylic acid, cinnamic acid, maleic anhydride may be used. acids, vinyl sulfonic acid and fluorine-containing acrylates,
A thermoplastic resin containing an electron-withdrawing monomer component such as fluorine-containing methacrylate may be used. When using an acidic monomer, a counter cation may be added to form a salt structure.

In addition to the above-mentioned components, the toner of the present invention may contain various plasticizers (diptylphthalate, dioctyl phthalate, etc.), resistance control agents ( It is also possible to add auxiliary agents such as tin oxide, lead oxide, antimony oxide, etc.). Furthermore, in the present invention, after producing toner particles (5 to 20-), fine powders such as TiO□, AhO*, 5ift, etc. are added to the toner particles and the toner surface is coated with these particles, thereby modifying the fluidity of the toner. It is also effective to add zinc stearate, phthalic acid, etc. to prevent deterioration of the photoreceptor.

In addition, when using a carrier in the developer, conventionally known carriers can be used, such as magnetic substances such as iron, cobalt, and nickel, alloys or mixtures of these, or carriers coated on the surface of these. can be mentioned.

A general method for producing the yellow toner of the present invention is as follows.

(1) The resin and colorant (and optionally additives such as a charge control agent) are uniformly dispersed using a Henschel mixer or the like.

(2) Melt and knead the dispersion using a kneader, extruder, roll mill, or the like.

(3) After coarsely pulverizing the mixed material with a cutter mill, hammer mill, etc., finely pulverizing it with a Gencle, I-type mill, etc.

(4) The finely pulverized material is classified using a DS (dispersion classifier), a zigzag classifier, or the like.

(5) Optionally, silica or the like is dispersed in the classified material using a Henschel mixer or the like.

In addition, production by suspension polymerization is also possible as another method.

〔Example〕

EXAMPLES Hereinafter, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited to these Examples.

In addition, the polyester resin used in the following examples can be obtained by Synthesis Example 1 shown below, and styrene-based resin
The acrylic resin can be obtained by Synthesis Examples 2 and 3 shown below.

Synthesis Example 1 Polyoxypropylene (2,2) was placed in a reaction vessel equipped with a stirring device, a thermocouple for temperature control, a reflux dehydration tube for cooling and removing reaction product water (or alcohol), and a nitrogen blowing tube.
-2,2'-bis(4-hydroxyphenyl)propane 350.0 parts by weight, fumaric acid 116.0 parts by weight,
Add 0.2 parts by weight of hydroquinone monomethyl ether, gradually raise the temperature, and perform a dehydration condensation reaction at 210°C, softening point (SP) = 98.6°C, glass transition point (Tg)
= 60.5°C polyester resin was obtained. Although the resin was slightly brown and transparent, the effect on color as a binder resin for color toners was negligible.

Synthesis Example 2 60% of toluene was placed in a reaction vessel equipped with a stirring device, a thermocouple for temperature control, a reflux tube, a dropping funnel, nitrogen, and a blowing tube.
0 parts by weight and 5.0 parts by weight of dodecyl mercaptan were charged, and the temperature was raised to 90°C under a nitrogen blanket, followed by 120.0 parts by weight of styrene and 70.0 parts by weight of n-butyl methacrylate.
0 parts by weight, diethylaminoethyl methacrylate 10.0
Parts by weight, α, α゛ -Azobisisobutyronitrile 4.
0 parts by weight of the mixed solution was dropwise polymerized over 2 hours, and further 2 parts by weight of the mixed solution was added.
After the time aging reaction, the temperature was raised to 200"C and 30m
The pressure was reduced to 11 g and topped with toluene. The obtained resin is colorless and transparent, has an sp of 104°5'C, and a Tg of 62.
．． It was 3°C.

Synthesis Example 3 Into a reaction vessel similar to Synthesis Example 2, 60.0 parts by weight of toluene and 3.0 parts by weight of dodecyl mercaptan were charged, and the temperature was raised to 70''C under nitrogen sealing.
0.0 parts by weight, 2-ethylhexyl acrylate 20.0
Parts by weight, 10.0 parts by weight of acrylic acid, and 6.0 parts by weight of α,α゛-azobisdimethylvaleronitrile were dropwise polymerized over 2 hours, and further aged for 2 hours, followed by 200 parts by weight. The temperature was raised to "C", the pressure was reduced to 30mm1[g, and toluene was added to the top.The resulting resin was colorless and transparent.
p was 106.2''C and Tg was 68.8°C.

Example 1 Chromophthal Yellow GR5 weight part The above blend was mixed in a Henschel mixer, melt-kneaded in a hot roll mill, cooled, coarsely ground in a hammer mill, and further finely ground in an air jet mill. The obtained fine powder was classified to obtain a yellow toner having a particle size of 5 to 20 ρ.

A developer was prepared by mixing 5 parts by weight of this toner with 95 parts by weight of an iron powder carrier having a particle size of about 74-125. The initial blow-off charge amount of this developer is -12μC/g
Met.

When a toner image was formed using a commercially available copying machine using this developer, a clear yellow image without background fog and color unevenness was obtained. In addition, 2000 sheets were continuously copied, but no deterioration in image quality was observed.
When the image was projected using copy LOIIP onto a Mylar film for P images, a clear yellow color was reproduced in the projected image and the transparency was also good. Furthermore, when the light resistance was evaluated using a weather meter (manufactured by Suga Test Instruments Co., Ltd.), no fading was observed even after 40 hours of ultraviolet irradiation, and the film had extremely excellent light resistance.

Example 2 Chromofine Yellow 5900 7 parts by weight A yellow toner was obtained in the same manner as in Example 1 using the above formulation.

A developer was prepared using this toner in the same manner as in Example 1, and the initial blow-off charge amount was +10 μC/g.

Using this developer, a copy image was evaluated in the same manner as in Example 1, and a clear yellow image with no background capri was obtained, and the toner showed satisfactory image quality in terms of transparency, light fastness, and durability. Met.

Furthermore, when this developer was allowed to stand at a high temperature and high humidity of 35° C. and 185% RH, no deterioration in chargeability was observed.

Example 3 Styrene-acrylic acid ester copolymer obtained in Synthesis Example 3 100 parts by weight Chromophthal Yellow GR 5 parts by weight A yellow toner was obtained in the same manner as in Example 1 using the above formulation.

When a developer was prepared using this toner in the same manner as in Example 1, the initial blow-off charge amount was -14 μC/g.

Using this developer, a copy image was evaluated in the same manner as in Example 1, and a clear yellow image with no background capri was obtained, and the toner showed satisfactory image quality in terms of transparency, light fastness, and durability. Met.

Further, 5,000 copies were continuously made using a commercially available copying machine using this developer, but no deterioration in image quality was observed.

Example 4 A yellow toner was obtained in the same manner as in Example 1 using 4 parts by weight of Chromofine Yellow 5900 as described above.

A developer was prepared using this toner in the same manner as in Example 1, and the initial blow-off charge amount was +10 μC/g.

Using this developer, a copy image was evaluated in the same manner as in Example 1, and a clear yellow image with no background capri was obtained, and the toner showed satisfactory image quality in terms of transparency, light fastness, and durability. Met.

Further, this developer was left at 35° C. and 85% R1+ under high temperature and high humidity conditions, but no deterioration in chargeability was observed.

Comparative Example 1 Neoben Yellow 159 (manufactured by BASF) 3 parts by weight A yellow toner was obtained in the same manner as in Example 1 using the above formulation.

A developer was prepared using this toner in the same manner as in Example 1, and the initial blow-off charge amount was -7 μCog.

When this developer was used to evaluate a copied image in the same manner as in Example 1, only a yellow image with low brightness was obtained, and the toner was unusable in terms of the spectral reflection characteristics of the image.

Comparative example 2 A yellow toner was obtained in the same manner as in Example 1 using the above formulation.

A developer was prepared using this toner in the same manner as in Example 1, and the initial blow-off charge amount was -9 μC/g.

Using this developer, a copy image was obtained in the same manner as in Example 1,
When the light resistance of the image was evaluated, it was found that the color faded significantly after irradiation for 40 hours, which is not preferable for practical use in light of the purpose of the present invention.

Comparative Example 3 A yellow toner was obtained in the same manner as in Example 1 using the above-mentioned formulation of 1 weight of Chromophthal Yellow GR0.08.

A developer was prepared using this toner in the same manner as in Example 1, and the initial blow-off charge amount was 14 μC/g.

When this developer was used to evaluate copied images in the same manner as in Example 1, only images with low chroma and blurred colors were obtained, and the toner was not usable for practical use in terms of coloring power.

Comparative example 4 Chromophthal Yellow GR255 weight A yellow toner was obtained using the same procedure as in Example 1.

A developer was prepared using this toner in the same manner as in Example 1, and the initial blow-off charge amount was -5 μC/g.

When a copy image was evaluated using this developer in the same manner as in Example 1, the background capri of the image was significant and 0I
When the image was projected onto IP film in 1'Ii format and 011P format, the image appeared gray and it was confirmed that the transparency was low.

Claims (1)

[Claims] In color toner made of thermoplastic resin and colorant,
The colorant is C.I. I. A yellow toner for electrostatic development, characterized in that the main component is a compound classified as Pigment Yellow 95, and 0.1 to 20 parts by weight of a coloring agent per 100 parts by weight of a thermoplastic resin.