JPH0327050A - Developer for electrostatic charge image - Google Patents

Abstract

PURPOSE:To enhance chargeability characteristics of the developer and image quality by adding a specified compound powder to the outsides of toner particles containing a specified charge controller and using 2 kinds of specified carriers in combination with the powder. CONSTITUTION:This developer to be used is prepared by adding a basic powder of magnesium.aluminum bydroxycarbonate.hydrate represented by formula II (m is an optional integer and each of p - s is an integer satisfying prescribed relationships) to the outsides of the toner particles containing at least a resin, a colorant, and the charge controller of a quaternary ammonium salt represented by formula I (R<1> is 1 - 8 C alkyl; each of R<2> and R<3> is 1 - 18 C alkyl; and R<4> is 1 - 8 C alkyl or benzyl), and in combination with this toner adding the 2 kinds of carriers comprising a ferrite powder coated with a methylsilicone resin and a ferrite powder coated with a methylphenylsilicone resin.

Description

[Detailed Description of the Invention] <Prior Art> During the development process, the developer used in electronic copying machines and the like is once attached to an image carrier such as a photoreceptor on which an electrostatic image is formed. The image is then transferred from the photoreceptor to transfer paper in a transfer step, and then fixed on the copy paper surface in a fixing step.

In this case, as a developer for developing the electrostatic charge image formed on the latent image holding surface, a two-part developer consisting of a carrier and a toner and a one-part developer that does not require a carrier are used. (magnetic toner) is known.

Conventionally, charge control agents such as nigrosine dyes and quaternary ammonium salts, carrier coating agents, and the like have been known as agents that impart chargeability to developers.

Problems to be Solved by the Invention> However, these conventional chargeability imparting agents do not necessarily have a satisfactory chargeability imparting effect, and they do not have the ability to stably exhibit appropriate chargeability regardless of the environment. It is difficult to obtain a toner that exhibits a favorable change over time, and the problem is that image stains such as capri occur under low temperature and low humidity conditions, high temperature and high humidity conditions, or during continuous copying, or stable copy density cannot be obtained. It became.

As a result of intensive studies to solve this problem, the present inventors have found that toner particles containing a quaternary ammonium salt represented by a specific structural formula as a charge control agent contain basic magnesium aluminum hydroxy carbonate hydride. By mixing a toner formed by externally adding rate powder with resin-coated ferrite powder and using methyl silicone resin and methyl phenyl silicone resin together as the resin, the toner exhibits favorable charging characteristics and has excellent image quality and durability. The present inventors have discovered that a developer can be obtained, and have arrived at the present invention. That is, an object of the present invention is to provide a developer for developing electrostatic images with excellent charging characteristics and less deterioration of image quality over time and environment.

<Means for Solving the Problems> Therefore, an object of the present invention is to add basic magnesium alkali to toner particles containing at least a resin, a colorant, and a quaternary ammonium salt represented by the following general formula (1). A developer for developing electrostatic images containing a toner externally added with ξnium hydroxy carbonate hydrate powder, ferrite powder coated with methyl silicone resin, and ferrite powder coated with methyl phenyl silicone resin. This can be easily achieved by drugs.

・ ・ ・ [r] (In the formula, R' represents an alkyl group having 1 to 8 carbon atoms, and R2
and R3 each represent an alkyl group having 1 to 18 carbon atoms, and R4 represents an alkyl group having 1 to 8 carbon atoms or a benzyl group. ) (Function) The present invention will be explained in detail below.

The quaternary ammonium salt used in the present invention has the general formula (
Salt-forming compounds of quaternary ammonium salt and naphtholsulfonic acid as represented by 1) include, for example, the following compounds.・ ・ ・(11 ・ ・ ・(3) ・ ・ ・(4) ・ ・ ・(8) ・ ・ ・(9) ・ ・ ・0■ Resin components that can be used in the present invention include electrostatic charge image Various known toners suitable for developing toners can be used.For example, styrene resins, styrene-acrylic copolymer resins, polyester resins, epoxy resins, and mixed resins thereof; Among them, styrene-based or polyester-based resins are preferred.The content of the compound represented by the general formula (1) in the toner is as follows:
The amount is preferably 0.1 to 10 parts by weight, more preferably 1 to 3 parts by weight, based on 100 parts by weight of the resin.

The coloring agent used in the present invention is not particularly limited as long as it has been conventionally used in toners of various colors, and for example, carbon black or the like is used for black toners.

The content of the colorant is 3 to 20 parts by weight per 100 parts by weight of the resin.
Preferably, it is expressed in parts by weight.

Furthermore, in addition to the compound represented by the general formula (1), the toner of the developer of the present invention may contain other charge control agents, including known ones, such as polyamine resins and/or nigrosine dyes. It may also be included.

In addition, as part of the toner composition of the developer of the present invention, additives such as a low molecular weight olefin polymer or finely divided silica may be added internally or externally to improve fixing properties and fluidity.

Toner particles can be produced by kneading the above ingredients in a kneader or the like, cooling, pulverizing, and classifying. The average particle diameter of the toner particles is preferably 5 to 20 μm. .

On the other hand, basic magnesium aluminum hydroxy carbonate hydrate to be externally added to toner particles is represented by the following general formula (II), Mgp Alq (OH) r (COz ) s
・mHz ○... (II) (In the formula, p, q.r and S represent integers that satisfy 2p+.3q=r+2S, m represents any integer.) Among these, M g b A lt ( O H ) +
x C; 0 34H20 or Mga,sAl■ (
○H) 13CO33.5H! Compounds called hydrotalcites such as ○ are conveniently used.

When this basic magnesium aluminum ξnium hydroxy carbonate hydrate is treated with a fatty acid, part of it becomes a metal salt, and the hydrate powder after such treatment can also be suitably used in the present invention.

Further, the amount of the external additive is preferably 0.01 to 1 part by weight per 100 parts by weight of the binder resin. The developer of the present invention is characterized in that the toner produced as described above is mixed with two types of carriers having different types of silicone resins for coating the surface.

That is, silicone resin consists of a macromolecule in which silicon atoms are bonded to each other via siloxane bonds and spread out in a network, and the silicone resin is composed of a macromolecule in which silicon atoms are bonded to each other through siloxane bonds and are spread out in a network. Non-bonded silicon atoms usually have hydroxyl groups, and resins in which at least a portion of the hydroxyl groups are replaced with methyl groups, or methyl groups and phenyl groups are called methyl silicone resins and methylphenyl silicone resins, respectively. .

The carrier used in the developer of the present invention contains at least both ferrite powder coated with methyl silicone resin and ferrite powder coated with methyl phenyl silicone resin. There is no particular limit to the particle size of the carrier, but it is between 10 and 2.
Ferrite having an average grain size of 0.00 μm is preferred. These carriers may be used in an amount of 5 to 10 parts per part by weight of toner.
It is preferable to use 0 part by weight of the ferrite coated with methylphenyl silicone resin, and 5 to 50 wt% of the total carrier, more preferably 10 to 30 wt% of the ferrite coated with methylphenyl silicone resin.
It is preferable to set it as %. <Examples> Hereinafter, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited in any way by the following Examples unless the gist thereof is exceeded.

In addition, in the following examples, the term "r parts" means "parts by weight."

Example 1> was blended, kneaded, pulverized and classified to obtain black toner particles with an average particle size of 11 μm. 0.0 parts of fine silica powder (R-972 manufactured by Nippon Aerosil ■) per 100 parts of the black toner particles.
Part 2 and hydrotalcite compounds (MgiAlz
(OH) ・4H. O) fatty acid treated fine powder 0.
Three parts were externally added using a Henschel mixer.

4 parts of the obtained toner, 50 parts of ferrite powder coated with methyl silicone resin having an average particle size of about 100 μm, and 50 parts of ferrite powder coated with methyl phenyl silicone resin.
A developer was prepared by mixing and stirring the following parts.

Next, using this developer, a photocopying machine using an organic photoconductor as a photoconductor was used to conduct a photocopy test of 100,000 sheets under high temperature/high humidity conditions of 40"C/85-90% RH.Used for photocopying test. The supplied replenishing toner is from the same group as the toner used in the developer.

As a result of the live-copying test, it was found that there was no increase in fog, which is dirt on the white background of the copy, even after iooooo copies were made, and the black part of the copy had high uniformity and density, and it could be used under high temperature and high humidity without any decrease in density. The toner and developer had excellent durability even under harsh environments; Example 2 Hydrotalcite compound used in Example 1. Example 1 was carried out in exactly the same manner as in Example 1, except that the amount of fine powder treated with fatty acids was changed to 0.05 part. There was no increase in capri even after a test of 100,000 copies, and the black background of the copies was uniform. A toner developer with high density and excellent durability with no decrease in density was obtained.

<Example 3> The same procedure as Example 1 was carried out except that the amount of fine powder of hydrotalcite compound treated with fatty acid was 1.0 part. There was no increase in fog even after 1,000,000 sheets were photographed. A toner and developer with excellent durability and uniformity in black areas and high density were obtained. Example 4> Fine powder of a hydrotalcite compound that is not treated with fatty acids was mixed with 0. When the same procedure as in Example 1 was carried out except that 3 copies were used, a toner and developer with excellent durability with no increase in fog, uniform density, and no decrease in density even after the ioooooo sheet actual copy test was obtained. Ta.

Example 5> was blended, kneaded, pulverized and classified to obtain magenta toner particles having an average particle size of 11 am.

For each 100 parts of magenta toner particles, 0.2 parts of silicate powder (R-972 manufactured by Nippon Aerosil ■) and a hydrotalcite compound (Mg&A/!z(OH).4H.
O) 0.3 part Henschel ξ of fatty acid-treated fine powder
It was treated with external additives using a kisser. The obtained magenta toner was mixed with exactly the same carrier as used in Example 1 to prepare a developer. As in Example 1, a photo-photographing test was conducted, and even after 30,000 sheets were photo-photographed, the toner and developer were free from fog and had high density uniformity.

Comparative Example 1> A toner and developer were manufactured in exactly the same manner as in Example 1, except that the hydrotalcite i compound was not used, and a live-photographing test was conducted. From the time of about 3,000 sheets, stains on the white background, that is, fogging, were observed. This developer could not be used in practice due to problems such as increased density and decreased copy density. <Comparative Example 2> Example 5 was carried out in exactly the same manner as in Example 5 except that the fine powder of the hydrotalcite compound was not used. However, fogging increased after approximately 2,000 sheets were printed, and the copy density decreased, making it unsuitable for practical use. There was no developer.

Effects of the Invention The toner for developing electrostatic images of the present invention has good charging performance, always exhibiting appropriate and stable charging properties, and is resistant to the conventional problems of high temperature, high temperature, low temperature and low humidity, or during continuous copying. It provides a good image regardless of the conditions of use, such as less copy staining and lowering of image density, and provides great industrial benefits.

Claims (1)

[Claims] (1) At least a resin, a colorant and the following general formula (I
) A toner formed by externally adding basic magnesium aluminum hydroxy carbonate hydrate powder to toner particles containing a quaternary ammonium salt represented by
A developer for electrostatic image development comprising ferrite powder coated with methyl silicone resin and ferrite powder coated with methyl phenyl silicone resin. ▲There are mathematical formulas, chemical formulas, tables, etc.▼...[I] (In the formula, R^1 represents an alkyl group having 1 to 8 carbon atoms, and R
^2 and R_3 each represent an alkyl group having 1 to 18 carbon atoms, and R^4 represents an alkyl group having 1 to 8 carbon atoms or a benzyl group. )