JPS60194464A - Carrier material - Google Patents

Abstract

PURPOSE:To improve the power to apply friction electrified charge to a toner, a life as a developer, stability in environment of a high temp. and high humidity or low temp. and low humidity, etc. by coating a carrier with a metallic complex of 8-oxyquinoline. CONSTITUTION:The metallic complex of 8-oxyquinoline expressed by the formula is incorporated into a carrier surface to obtain an intended carrier material. The more specific coating method is exemplified by a method of dissolving or dispersing the metallic complex of 8-oxyquinoline into a solvent and immersing the carrier in such soln. or dispersion, a method of mixing the powder metallic complex of 8-oxyquinoline with the carrier in a dry process or a method of dispersing the metallic complex of 8-oxyquinoline with a resin (e.g.; acrylic resin, melamine resin) at about 0.1-20pts.wt. for each 100pts.wt. the resin then mixing the same with the carrier.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to carriers used in developers for developing electrostatic latent images in electrophotography, electrostatography, and the like.

A conventional method for visualizing an electrostatic latent image using a developer is, for example, US Pat. No. 2,874.

Magnetic brush method described in Specification No. 063, No. 2
, 618,552, etc. are known.

Generally, the developer used in these developing methods is a fine powder toner in which dyes and pigments are dispersed in a binder, and this toner is applied to an electrostatic latent image formed on a 7-year-old photographic material by an appropriate means. A mixture with a solid support carrier is used to convey the . When mixed with the toner, this solid support carrier acts to impart the desired triboelectric charge to the toner, so that the toner is transported to the latent image and developed.

In a general developer, a portion of toner, which is one of its components, is lost during development, and the amount is replenished. However, the other component, the carrier, is hardly lost during development and is used over and over again, so as a large number of copies are made, the following surface changes occur.

(1) Changes in the surface condition due to carrier-carrier collisions and collisions with various members such as walls or screws in the carrier developing device (2) Fine toner or some of the toner's constituent components are transferred to the carrier. Changes in the surface condition due to adhesion or adsorption - The triboelectric charging ability of the carrier to the I/N is greatly affected by the material and shape of the carrier. Changes in condition include an increase in "padding" in non-image areas, a decrease in density in image areas,
This causes deterioration phenomena such as non-uniformity of the black background over a wide area, and the entire developer must be replaced.

The objects of the present invention are as follows.

(1) Providing a carrier material with high ability to impart triboelectric charge to toner.

(2) Providing a carrier material that has a long life as a developer.

(3) Providing a carrier material for a developer with excellent reproducibility.

(4) Providing a carrier material for a developer with high environmental stability such as high temperature and high humidity, low temperature and low humidity.

(5) Appropriate control of triboelectricity of toner.

Its special feature lies in the carrier material containing a metal complex of 8-oxyquinoline.

The 8-oxyquinoline metal complex used in the present invention has a structure as shown in the figure below.

The present invention attempts to achieve the above-mentioned object by uniformly coating a carrier with this metal complex of 8-oxyquinoline. That is, by using a carrier containing a metal complex of 8-oxyquinoline on the surface, negative i
- Can improve the ability to apply negative tripo to Gnar. On the other hand, for conventional positive toners whose positive properties are too strong and the image density decreases due to charge-up or other reasons during image development durability, the application of tripo is adjusted and appropriate tripo is applied. You can control the value.

In the present invention, the method of coating the gear core with the metal complex of 8-oxyquinoline includes a method of directly coating the metal complex of 8-oxyquinoline alone, and a method of coating the metal complex of 8-oxyquinoline by dispersing it in a resin. There is a way to do it. For direct coating, the metal complex of 8-oxyquinoline is dissolved or dispersed in a solvent, and the carrier is immersed in the solution. Alternatively, there is a method of dry mixing a powdered 8-oxyquinoline metal complex with a carrier. In addition, methods for dispersing □ in resin and coating it on the carrier are particularly limited, such as dousing or spraying the gear core in a resin solution in a tank, or using a controlled fluidized bed method. isn't it.

As the resin used for dispersing 8-oxyquinoline, those conventionally used can be used as they are. For example, natural resins, polyolefin resins/polyvinyl, polyvinylidene resins, fluorocarbon resins, polyamide resins, polyester resins, polyurethane resins, polycarbonate resins, phenolic resins, acrylic resins, melamine resins, amine resins, epoxy resins, etc., and mixtures thereof. be.

For these resins, the content of the metal complex of Coke 8-oxyquinoline varies depending on the resistivity of the resin and the state of dispersion in the resin, and the development conditions in which the coated carrier is used, but is approximately 100% of the resin. 0.1 parts by weight
~20 parts by weight is preferred.

As the carrier core used in the present invention, conventionally known carrier cores such as iron powder, ferrite, glass beads, etc. can be used as they are.

(Example 1) 70 parts by weight of thermosetting acrylic resin (in terms of solid content), 20 parts by weight of melamine resin, 10 parts by weight of epoxy resin, and 5 parts by weight of 8-oxyquinoline/Co were mixed into xylene/butanol =
The mixture was dissolved in a 7/3 mixed solvent and thoroughly mixed and dispersed using a suitable disperser to prepare a solution having a concentration of 1% in terms of resin solid content.

Dip the carrier iron powder into this solution and stir it.
Heat while stirring to remove the solvent. After removing all the solvent, a coated carrier was obtained.

88 parts by weight of this coated carrier and 12 parts by weight of toner whose main component is polyester resin were combined for 77 days and the tripo charge amount of the toner was measured by the blow-off method.
It was 10.5gc/g.

When images were produced using this developer, very good images were obtained with good reproducibility of black backgrounds over a wide range and without any practical problems.

Furthermore, when images were produced using this developer at 30°C and 85% high temperature and high humidity, the 2000th image was as good as the initial image (Comparative Example 1) A coated carrier was prepared in the same manner as in Example 1, except that the 8-oxyquinoline in Example 1 was omitted. Is this carrier 4F with toner? The tripo charge amount of the toner when combined was -3.2 μc/g. This developer was used at 30°c80 in the same manner as in (Example-1).
% environment, the fog was severe from the first image, and by about the 50th image, it exceeded the practical limit.

(Example 2) The coating resin in Example 1 was changed to 80 parts by weight of holamide resin and 20 parts by weight of phenol resin, and the amount of 8-oxyquinoline/Co added was changed to 10 parts by weight per 100 parts by weight of resin. A coated carrier was obtained by carrying out almost the same procedure as in Example 1 except for this.

88 parts by weight of the obtained carrier and styrene acrylic
When 12 parts by weight of a toner containing HMA-dimethylaminoethyl methacrylate resin as a main component was mixed and the tripo charge amount of the toner was measured using the blow-off method, it was found to be +14.
．． It was 5pc/g.

When this developer was used to produce an image, it was found to be in good condition, with the wide black areas of the character building being faithfully reproduced in the manuscript.

(Comparative Example 2) A carrier obtained in the same manner as in Example 2 except that 8-oxyquinoline in Example 2 was removed was mixed with the same toner as in Example 2, and the toner's tripo charge amount was determined in the same manner. When measured, it was +55.28 LC/g.

When I created an image using this developer, I found that it was 100%
On the 0th sheet, the image density decreased and was outside the practical limit.

(Example 3) 8-oxyquinoline C in Example 1.

The same procedure as in Example 1 was carried out except that 8-oxyquinoline Cr was used instead, and the tripo charge amount was measured in the same manner, and it was found to be -8.3 #Lc/g. Further, when the same evaluation as in Example 1 was performed, good results were obtained.

(Example 4) In place of 8-oxyquinoline Co in Example 1, 8
A similar evaluation was performed using -oxyquinoline-Zn, and good results were also obtained.

Applicant: Canon Co., Ltd.

Claims (3)

[Claims] (1) A carrier material containing a metal complex of 8-oxyquinoline. (2) The carrier material according to claim 1, wherein a metal complex of 8-oxyquinoline is contained on the surface. (3) The carrier material according to claim 1, which is coated with a resin in which a metal complex of 8-oxyquinoline is dispersed.