JPH02163757A - Toner for developing electrostatic charge image - Google Patents

Abstract

PURPOSE:To obtain a toner positively chargeable over a long period of time without deteriorating the color of a coloring material, especially useful for a two-component dry developer and preventing offsetting phenomenon by incorporating a specified onium compd. as an electrostatic charge controller. CONSTITUTION:This toner for developing an electrostatic charge image contains an onium compd. represented by formula I as an electrostatic charge controller. In the formula I, R<1> is H, hydroxy or 1-4C alkoxy, R<2> is 1-4C alkylene, R<3> is H, 1-18C optionally substd. alkyl or aralkyl and each of R<4> and R<5> is 1-6C alkyl or a group forming a hetero ring together with N. Since the colorless or light-colored polarity controller is contained, high thermal stability and compatibility with a resin component are ensured without deteriorating the color of a coloring material and a stable image is always obtd. This toner is suitable for a one- or two-component dry developer.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a toner for developing electrostatic images, and more specifically, it can be used as a one-component dry developer, but it also contains a specific toner that is particularly useful in a two-component dry developer. The present invention relates to a toner for developing electrostatic images containing a compound as a charge control agent (polarity control agent).

[Prior art]

W formed on electrophotographic photoreceptors, electrostatic recording materials, etc.
As a means for developing an I-electronic image.

There are two methods: a method using a liquid developer (wet method), and a method using a toner in which a colorant is dispersed in a binder resin, or a one-component or two-component dry developer in which this toner is mixed with a solid carrier (dry method). Development method) is generally adopted.

Each of these methods has its advantages and disadvantages, but
Dry developing method is often used in @Japan.

As mentioned above, a dry developer is a two-component developer consisting of a mixture of (1) a carrier and a toner (a fine 1-toner with an average particle size of about 15 μm in which a colorant is dispersed in a natural or synthetic resin); .

and (2) a two-component developer consisting only of toner similar to (1) above. In addition to this, magnetic toners in which magnetic fine powder is further contained in -component dry developers are also known.

In these dry developers, the two-component developer described in (1) above achieves development by attaching the charged toner to the electrostatic latent image through friction with the carrier, and the two-component developer described in (2) above. At present, the -component type developer is charged by friction with a friction member such as a brush or plate having a similar resin instead of a carrier for development.

Two-component developers are more commonly used because they are superior in the reliability of visualization. In any case, the developing toner can have a positive or negative charge depending on the polarity of the electrostatic latent image to be developed.

In order to cause the toner to have a positive or negative charge, it is also possible to use the triboelectricity of the resin, which is the main component of the toner, but this method has a low chargeability of the toner, so the image obtained by development is is easily fogged and becomes unclear. Also, in order to have a positive charge.

Although there are resins in which certain functional groups are introduced, they have the disadvantage that the functional groups generate an unpleasant odor during heat fixing and that the amount of charge varies widely. Therefore, in order to impart desired triboelectric charging properties to the toner, it is common practice to add a charge control agent. At present, the nigrosine dyes disclosed in Japanese Patent Publication No. 41-2427, U.S. Pat.
Examples include the quaternary ammonium salt disclosed in the specification of No. 4 and the polyamine resin disclosed in Japanese Patent Publication No. 13284/1984.

However, many of the above-mentioned charge control agents that have been put into practical use are suitable for black toner compositions but not for color toner compositions, or are provided as colorless charge control agents. The quaternary ammonium salt used in the toner is water-soluble and difficult to uniformly disperse in the toner, and the applied charge tends to be non-uniform. Even if the IE conductivity is high, the IE conductivity attenuates exponentially depending on the storage conditions, and the attenuation of the IE conductivity is particularly large when the temperature or humidity is high.

As a solution to this drawback, for example, Japanese Patent Application Laid-open No.
No. 11461, JP-A-57-54953, JP-A-57
-119364, JP-A-58-9154, JP-A-5
Although various charge control agents have been proposed in publications such as No. 8-981=12, the reality is that none of them satisfies the present inventors.

〔the purpose〕

The first object of the present invention is to provide a one-component or two-component dry developer that contains a colorless or light-colored polarity control agent to positively control charge over a long period of time without impairing the original color of the coloring material. This invention provides a toner particularly useful for two-component dry developers. The second object of the present invention is to have good thermal stability and good compatibility with resin components, so that there is no deterioration during manufacturing, and not only stable images can always be obtained, but also durability and The present invention provides a toner for developing static images with excellent environmental stability.

A third object of the present invention is to provide a dry toner that does not cause offset phenomenon.

(Structure) The toner for developing an electrostatic image of the present invention has the following properties: R1 is hydrogen, C1 to CL1 substituted or unsubstituted alkyl group or aralkyl group, R4 and R5
Each of these is a C to C6 alkyl group or a group that forms a heterocycle with nitrogen. ) is characterized by containing a compound represented by the following as a charge control agent.

Incidentally, the inventor of the present invention has conducted various studies and examinations regarding the charge control of dry toner, and has confirmed that the onium compound represented by the above formula is extremely effective as a positive charge control agent. The present invention has been made based on this.

The compound represented by the above general formula used as a charge control agent in the present invention can be obtained by a well-known onium compound production method.

It is as follows.

The onium moiety in the above general formula is as follows.

N,N,N-trimethyl-N-2-(3-hydroxy-
2-Naphthamido)ethylammonium, N, N, N-
Triethyl-N-2-(3-hydroxy-2-naphthamido)ethylammonium, N,N,N-trimethyl-
N-3-(3-hydroxy-2-naphthamido)propylammonium, N,N-dimethyl-N-ethyl-N=
3-(3-hydroxy-2-naphthamido)propylammonium, N,N,N-trimethyl-N-4-(3-
hydroxy-2-naphthamido)butylammonium,
N,N-dibutyl-N-methylto-3-(3-hydroxy-2-naphthamido)propylammonium.

N-methyl-N-3-(3-hydroxy-2-naphthamido)propylmorpholinium, N-2-(3-hydroxy-2-naphthamido)ethylpyridinium.

N,N-dimethyl-N-benzyl-N-3-(3-hydroxy-2-naphthamido)propylammonium, N
, N-dimethyl-N-p-chlorobenzyl-N-3-(
3-Hydroxy-2-naphthamido)propylammonium, N,N-diethyl-N-p-nitrobenzyl-2-(3-hydroxy-2-naphthamido)ethylammonium, N,N-dimethyl-N-2',4' -dimethylbenzyl-3-(3-hydroxy-2-naphthamido)propylammonium, N,N-dimethyl-N-
P-chlorobenzyl-3-(2-naphthamido)propylammonium, N,N-dimethyl-N-ethyl-2
-(3-methoxy-2-naphthamido)ethylammonium, ,N,N-dimethyl-N-benzyl-3-(3-
ethoxy-2-naphthamido)propylammonium,
Examples include N,N-dimethyl-N(2,2,2-trifluoroethyl)-3-(3-hydroxy-2-naphthamido)propylammonium.

Here, some specific examples of the compound represented by the above general formula are as follows.

Note that the description in parentheses attached to each compound is the appearance and melting point.

(Slight yellow, 154-160°C) (Pale brown, 200-225°C) (Slight yellow, 163-181”C) (Slight yellow, 184-197°C) As the binder resin in the toner of the present invention, conventionally known binder resins are used. Styrenes such as styrene and parachlorostyrene; vinylnaphthalene; examples include vinyl chloride, vinyl bromide, vinyl fluoride, vinyl acetate, vinyl propionate, vinyl benzoate, vinyl butyrate, etc. vinyl esters such as methyl acrylate and ethyl acrylate.

n-butyl acrylate, isobutyl acrylate, dodecyl acrylate, n-octyl acrylate, acrylic acid 2
-chloro-ethyl phenyl acrylate, α-methyl chloroacrylate, methyl methacrylate, ethyl methacrylate.

Esters of α-methylene aliphatic monocarboxylic acids such as butyl methacrylate; vinyl ethers such as acrylonitrile, methacrylonitrile, acrylamide, vinyl methyl ether, vinyl isobutyl ether, vinyl ethyl ether; vinyl methyl ketone,
Vinyl ketones such as vinylhexylketone; e.g. N
- Polymers obtained by polymerizing monomers such as N-vinyl compounds such as vinylpyrrole, N-vinyllupazole, N-vinylindole, and N-vinylpyrrolidone, or a combination of two or more of these monomers. Polymerized copolymers or mixtures thereof, and/or non-vinyl thermoplastic resins such as rosin-modified phenol-formalin resins, oil-modified epoxy resins, polyurethane resins, cellulose resins, and polyether resins, or these and the above-mentioned vinyls. Examples include mixtures with other resins.

The dry toner of the present invention is usually heat-fixed during fixing, but especially when subjected to pressure fixing, polyolefin (low molecular weight polyethylene, low molecular weight polypropylene, polyethylene oxide, polytetrafluoroethylene, etc.) is used as the binder resin. , epoxy resin, polyester resin (acid value 1
0 or less), styrene-butadiene copolymer (monomer ratio 5-30:95-70), olefin copolymer (ethylene-acrylic acid copolymer, ethylene-methacrylic acid copolymer, ethylene-methacrylic acid ester copolymer) Union,
It is preferable to use ethylene-vinyl chloride copolymer, ethylene-vinyl acetate copolymer, ionomer resin), polyvinylpyrrolidone methyl vinyl ether-maleic anhydride copolymer, maleic acid-modified phenol resin, phenol-modified terpene resin, and the like.

Furthermore, in addition to the charge control agent (a compound represented by the general formula) and the binder resin, optional coloring agents such as pigments and dyes may be added to the toner of the present invention, if necessary.

, n colorants are known ones, such as carbon black, nigrosine dye, aniline blue, calco oil blue, chrome yellow ultramarine blue, DuPont oil red, quinoline yellow, methylene blue chloride, phthalocyanine blue, lamp black, oil black. , azo oil black, rose bengal and mixtures thereof.

The particle size of the toner of the present invention is suitably about 5 to 20 microns, and the compounding amount of the compound represented by the above general formula is 1/1 of the binder resin.
0.1 to 7 parts by weight, preferably 0.5 parts by weight
~4 parts by weight.

As described above, the toner of the present invention can be used as a two-component developer, but it is particularly effective to mix it with a carrier and use it as a two-component developer.

As a carrier, a core material with a particle size of about 50 to 300μI (
iron powder, nickel powder, ferrite powder, glass peas, etc.)
on the surface of styrene-acrylic ester copolymer, styrene-methacrylic ester copolymer, acrylic ester polymer, methacrylic ester polymer, silicone resin, polyamide resin, ionomer resin, polyphenylene sulfide resin, etc.

Alternatively, a coating with a mixture of these resins is used.

Next, examples and comparative examples will be shown. Parts here are by weight.

Example 1 7.0 parts of the compound represented by Specific Example &1, 6 parts of carboblack, and 100 parts of styrene-〇-butyl methacrylate copolymer are heated and kneaded. After cooling, it is roughly pulverized with a mixer, and then crushed and classified with a jet pulverizer to obtain a particle size of 1.
A powder (toner) of 0 to 20 μm was obtained. When this black toner was mixed and stirred with iron powder carrier at a weight ratio of 3:100, it became positively charged, and the charge amount by blow-off method was about 20.
It was μc/g.

Using this two-component developer, 10℃ 15% RH 130℃
When images were produced using a commercially available dry electrophotographic copying machine under conditions of 90% RH, clear images were obtained both initially and after 10,000 copies. Note that the amount of charge of the developer after copying 10,000 sheets was approximately 22.4 μc/g.

Example 2 A toner was prepared in exactly the same manner as in Example 1, except that 3.5 parts of the onium compound represented by Specific Example No. 2 and 7 parts of copper phthalocyanine pigment were used as the colorant. A developer was prepared. When this was used to produce images under the same conditions as in Example 1, a large number of good copies were obtained.

Examples 3 and 4 As an onium compound, 4.0 parts of Specific Example N113 (Example 3) or 6.5 parts of &4 (Example) were used, and 10 parts of low polymerized polypropylene (Sanyo Chemical Co., Ltd. (trade name: Viscol 550-P) and zinc stearate 1
A toner was prepared in exactly the same manner as in Example 1, except that part was newly added, and a two-component developer was prepared.

When this was used to produce images under the same conditions as in Example 1, a large number of good quality copies were obtained. Note that no change in the amount of charge of the developer was observed after copying 10,000 copies.

Comparative Example 1 The procedure was exactly the same as in Example 1, except that 6 parts of a nigrosine-based charge control agent (trade name: Bontron N-01, manufactured by Orient Chemical Industry Co., Ltd.) was used instead of 7 parts of the compound represented by NQI. When a toner was made and a two-component developer was prepared, the initial charge amount of the developer was approximately 12.8μc/
It was g. When printing 10,000 images under the same conditions as in Example 1, fogging occurred from around the 1st image, and the image became unclear.
It became a low level. Also, g, t of the developer at that time
i was approximately 30.3 μc/g.

Comparative Example 2 Instead of 3.5 parts of the compound represented by Specific Example Na 2,
A toner was prepared in exactly the same manner as in Example 2, except that 2 parts of stearyldimethylbenzylammonium-p-toluenesulfonate was used, and a two-component developer was prepared. Using this, an image was produced under the same conditions as in Example 1, and the initial charge amount of the developer was approximately 18.7 μc/g.
After 10,000 copies, the value varied greatly to about 34.1 μc/g, which was unsuitable for making a large number of copies in practice.

Claims (1)

[Claims] 1. The following formula ▲ Numerical formula, chemical formula, table, etc. ▼ (However, R^1 is hydrogen, hydroxy group, or C_1~C
_4 is an alkoxy group, R^2 is a C_1 to C_4 alkylene group, R^3 is hydrogen, C_1 to C_1_
(2) is a substituted or unsubstituted alkyl group or aralkyl group, and each of R^4 and R^5 is a C_1 to C_6 alkyl group or a group forming a heterocycle with nitrogen. ) A toner for developing an electrostatic image, characterized by containing a compound represented by: