JPH0264651A - Toner for electrophotography - Google Patents

Abstract

PURPOSE:To uniformly execute electrostatic charge impartation and to obtain the toner for electrophotography having excellent electrostatic chargeability by combining an acrylic resin and 'C.I. Solvent Orange 40(R)'. CONSTITUTION:The compd. classified as the 'C.I. Solvent Orange 40(R)' and the acrylic resin are used as the constituting components. The oil soluble dye classified as the 'C.I. Solvent Orange 40(R)' dissolves well into the acrylic resin in a binder resin for the toner and uniformizes the charge control agent components in the individual fine toner particles. The toner having the uniform electrostatic chargeability is obtd. in this way without generating the unequal ness in the electrostatic charge impartation.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to an electrophotographic toner, and more particularly to an electrophotographic toner using a charge control agent having good compatibility with a binder resin.

(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.

In the development process, a method using frictional charging of a resin, which is a component of the toner, is conventionally known as a method of imparting an electric charge to the toner. However, in this method, since the amount of charge on the toner is small,
2-hydroxy-3,5-'; nitrophenylazo)-
A charge control agent composed of dyes and pigments such as 3-phenylcarbamoyl-2-naphthol 1:2 type chromium complex salts, naphthenic acid metal salts, naphthenic acid metal salts and fatty acid metal soaps is used as an additive that imparts chargeability. Additions to toner 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 produced 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.

Accordingly, an object of the present invention is to eliminate the above-mentioned drawbacks of conventional electrophotographic toners, and to provide an electrophotographic toner that is uniformly charged and has excellent charging ability.

(Means and effects for solving the problems) The present invention has the following features:
The above object was achieved by constructing an electrophotographic toner characterized by containing a compound classified as C,1, Solvent Orange 40 in an acrylic resin as a charge control agent.

As a result of extensive research, the present inventors have discovered that the oil-soluble dyes classified as C, I, and Solvent Orange 40 dissolve extremely well in acrylic resins among toner binder resins.

Therefore, the electrophotographic toner of the present invention has C as a component,
! Because it uses a compound classified as Solvent Orange 40 and acrylic resin, it is melt-kneaded,
By granulating this, the charge control agent component in each fine toner particle produced becomes uniform, and as a result, it is possible to obtain a toner with extremely uniform chargeability without uneven charge application. .

In addition, this C,1, Solvent Orange 40 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 described below. 20°C
260%RH2,8564 35°C985%RH3,2110 It can be seen that the humidity dependence of the moisture content in the dye is extremely small. 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, C, I, 4jF of Solvent Orange 40
The amount of charge, for example, when measured by mixing with a ferrite carrier and blowing off, is on the order of about -34.3 μc/g, and it is clear that the toner using the above C,1, Solvent Orange 40 has excellent charging properties. Recognize.

(Preferred Embodiment of the Invention) Any acrylic resin can be used as the binder resin in the present invention, but from the viewpoint of transparency, which is effective in electrophotographic color toners, methacrylate-acrylate copolymer is preferred. is exemplified. 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, it 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 its anhydride 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. Methyl methacrylate (MMA) is most suitable as a methacrylate in terms of economy and transparency, and ethyl acrylate (EA) is most suitable as an acrylate in terms of melt leveling properties.

C,! , Solvent Orange 40 contains 0.0% per acrylic resin. It is preferably used in an amount of 5 to 10% by weight, especially 1 to 5% by weight; if it is less than the above range, there is no charge control effect, while if it is more than the above range, the stability of the toner deteriorates and carrier contamination etc. The problem arises.

C, R, and Solvent Orange 40, which are the constituent components of the present invention, are themselves compatible with the binder and exhibit an orange color, so they may be used alone or in combination with other colorants, and when used alone. produces an orange toner with excellent spectral transparency and is effective for creating transparent ranges for overhead 10 diectors (OHP).Any other colorants can be used, such as black pigment carbon black, acetylene, etc. black, lamp black, aniline black.

Yellow pigment yellow lead, zinc yellow, cadmium yellow, yellow iron oxide, mineral fast yellow, nickel titanium yellow, nabels yellow, naphthol yellow S1 Hansa Yellow G1 Han + Y Yellow IOC, benzidine yellow G1 benzidine yellow GR, quinoline yellow lake , Permanent Yellow NCG, Tartrazine Lake.

Orange pigment Red Garla, Cadmium Red, Red Lead, Mercury Cadmium Sulfide, Permanent Red 4R, Lysole Red, Pyrazolone Red, Watching Red Calcium Salt, Lake Red D1 Brilliant Carmine 6B, Eosin Lake, Rhodamine Lake B, Alizarin Lake, Brilliant Carmine 3B .

Red pigment manganese purple, Fast Violet 81 Methyl Violet Lake.

Blue pigments navy blue, cobalt blue, alkali blue lake, Victoria blue lake, phthalocyanine blue, metal-free phthalocyanine blue, phthalocyanine blue partially chlorinated product, first sky blue, indanthremble-BC
.

Green pigment chrome green, chromium oxide, pigment green B1
Malachite Green Lake, Fanal Yellow Green G.

white pigment Zinc white, titanium oxide, antimony white, zinc sulfide.

etc. are exemplified.

Further, the amount of the coloring pigment to be blended can be within a wide range depending on the purpose of the toner, and can be used within a range of 115 to 300% by weight based on the binder resin for boat fishing.

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

For example, in the method of fixing the developer with a heated roll, an offset preventing agent such as silicone oil, low molecular weight olefin resins, various waxes, etc. can be used in an amount of 2 to 15% by weight based on the total amount. In addition, for applications in which the developer is fixed with a pressure roller, a pressure fixing agent such as paraffin wax, various animal/vegetable waxes, fatty acid amide, etc.
It may be used in amounts ranging from 30% by weight.

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, rapid mechanical 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 preferably within the range of -g from 5 to 35 microns.

(Effects of the Invention) The toner of the present invention has C.I. I. By combining Solvent Orange 40, the charge in the toner is uniformly applied, and even after repeated development due to continuous use, stable chargeability and clear images can be maintained.

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

100 parts by weight of MMA + EA copolymer as a soil binder 8.5 parts by weight of carbon black (manufactured by Degussa, trade name: Printex L) as a coloring agent C0I, Solvent Orange 40 as a charge control agent (Manufactured by Hodogaya Chemical Industry Co., Ltd., product name 5PILON 0RANGE
2RH3P) 2 parts by weight Polypropylene (manufactured by Sanyo Kasei, trade name: Viscol 550P) 1. A mixture of 8 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.

C, I, Solvent Orange 40 (manufactured by Hodogaya Chemical Industry Co., Ltd., trade name 5P) used as a charge control agent in Example 1.
ILON 0RANGE2RH3P) and C8!
, Solvent Yellow 61 (manufactured by Hodogaya Chemical Industry Co., Ltd., product name 5PILON YELLOW 3RH3
A developer sample was produced in the same manner as in Example 1 except that P) was used.

Stopping basis 1: C, which was used as a charge control agent in Example 1; 1. Solvent Orange 40 (manufactured by Hodogaya Chemical Industry Co., Ltd., product name 5P)
rLON 0RANGE2RH3P) instead of C,!
, Solvent Blue 117 (manufactured by Hodogaya Chemical Industry Co., Ltd.)
A developer sample was produced in the same manner as in Example 1, except that 5PILON BLUE2BNH (trade name) 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 developer of Example 1 was used, very clear black images with no fog were obtained, and there was almost no image deterioration through 20,000 sheets, and almost no toner scattering was observed. On the other hand, when the developers of Comparative Examples 1 and 2 were used, significant fogging occurred and clear images could not be obtained.

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

(Margin below) Table 1

Claims (1)

[Claims] C.I. as a charge control agent. I. An electrophotographic toner characterized by containing a compound classified as Solvent Orange 40 in an acrylic resin.