JPS59129861A - Toner for use in powder developer - Google Patents

Abstract

PURPOSE:To prevent a toner from sticking and adhering to the surface of a carrier and a photosensitive plate by mixing an ethylene-acrylic acid copolymer with a toner for use in a powder developer contg. an epoxy compd. having >=one epoxy group and a colorant. CONSTITUTION:An intended powder developer toner is obtained by mixing (A) 100pts.wt. epoxycompd. having >= one epoxy group in the molecule, (B) 1- 10pts.wt. ethylene-acrylic acid copolymer expressed in the formula shown here in which n, m are each a positive integer, and X is H, methyl, or ethyl, and (C) a colorant, such as carbon black, kneading the mixture, then pulverizing and classifying it. The obtained toner has superior filming resistance due to a nonadhesive ethylene-acrylic acid copolymer incorporated in it.

Description

DETAILED DESCRIPTION OF THE INVENTION (1) Technical Field of the Invention The present invention relates to a toner for powder development, and more particularly to an improved toner for powder development that prevents adhesion and adhesion to carriers and photosensitive plate surfaces.

(2) Prior Art When a powder phenomenon is performed in an electrophotographic printer, facsimile, or copier, a mixture of colored resin powder called toner and iron powder or glass powder called carrier is used as the developer.

The toner generally used is a fine powder obtained by dispersing a coloring agent such as carden black in an adhesive resin. On the other hand, as the adhesive resin, a low polymer polymer generally called an oligomer is often used. Oligomers have low molecular weights, low melting temperatures, and good thermal stability, so they are widely used as adhesive resins for electrophotographic toners.

However, under recent circumstances where an increase in copying speed is required, the developer consisting of toner and carrier is agitated at high speed, causing the toner to stick to the surface of the carrier due to mutual frictional collisions. A phenomenon (toner filming) occurs, and as this progresses, the surface of the carrier is completely covered with a film of toner. Even when such a carrier is mixed and stirred with other toners, it does not cause triboelectric charging and completely loses its developing ability. Yet another problem is that toner adheres to the surface of the photosensitive plate, which causes changes in print density and fog.

As a method to prevent toner filming, the carrier side is considering coating the carrier surface with a non-adhesive resin for specific toner resins.
On the other hand, there is also a strong demand for measures to be taken to prevent the toner from sticking to the surface of the photosensitive plate.

(3) Object of the invention and its structure The object of the present invention is to improve the drawbacks of the conventional toner resin and to provide a toner resin which can prevent adhesion and adhesion to the surface of a carrier and a photosensitive plate.

That is, the powder developing toner of the present invention is characterized in that it consists of a nixy compound containing at least one epoxy group in the molecule as a main component and an ethylene-acrylic copolymer which is a non-adhesive resin. Particularly preferred is a toner containing 1 to 10 parts by weight of an ethylene-acrylic copolymer per 100 parts by weight of the epoxy compound. In this case, if the ethylene-acrylic copolymer is less than 1 part by weight, the filming resistance will not improve. Also, 10
Heavy vertical part? If it exceeds this, the filming resistance will not improve any further, and the viscosity will become too high, resulting in poor productivity.

Conventionally, when an epoxy resin alone is used as a binder resin, toner filming tends to occur because a relatively low molecular weight polymer must be used so that it can be melted and fixed with as little thermal energy as possible. Therefore, the present inventors developed an ethylene-acrylic copolymer that has a melting point in the low temperature range but is non-adhesive to metals etc. even in the softening temperature range, in addition to the relatively low molecular weight Epoquinsol polymer. They discovered that toner filming can be prevented without deteriorating the eyebrow consistency by mixing them, and the present invention was completed. The epoxy compound used in the present invention may be either an aromatic or aliphatic epoxy resin, such as an epoxy resin obtained from bisphenol A and epichlorohydrin, or a novolak epoxy resin obtained from a phenol resin and epichlorohydrin. , epoxy resins obtained from phthalic acid and epichlorohydrin, and epoxy resins obtained from aromatic amines such as toluidine or aniline and epichlorohydrin.

Further, the ethylene-acrylic copolymer used in the present invention has a bound ethylene content of 60% or more, preferably 80% or more, and if the bound ethylene i is 60% unvortexed, non-stick properties are lost, which is not preferable.

Furthermore, these copolymers are random copolymers and are represented by the following general formula.

H (where n, m are positive integers, X is U, CU3 or C2f
A specific example of the epoxy resin that can be used in the present invention is "Epicoat J 1001.1004.100" manufactured by Shell Co., Ltd.
7 and 1009, Ciba Geigy's [Araldite J
6071.7071.7072.608 ton 7097;
609. ．． 7 and 6099, Dow rDERJ
660.661.662.664.667.668 and 669, and Dainippon Ink's "Epicron J
1050.3050.4050 and 7050.

The toner of the present invention is prepared by adding a coloring agent to a theepoxy compound and an ethylene-acrylic copolymer and kneading them using a kneader or the like in a conventional manner. C. Crushing and classifying the obtained toner mass
The desired toner can be obtained. The present invention will be described below with reference to Examples and Comparative Examples. (4) Examples of the Invention and Effects thereof Epoxy resin (trade name [Ebicuron 4o5o4 manufactured by Inu Nippon Ink Chemical Industry Co., Ltd.] 88 parts by weight, ethylene bond J & 80
% ethylene-ethyl acrylic copolymer, 5 parts by weight, car? Black (Product name: ``Black Mother's L'')
5 parts by weight, dye (product name: Nigrosinpuji,
EXJ Orient Chemical Co., Ltd.) was kneaded for 1 hour in a kneader heated to 100° C., then crushed with a jet pulpizer and classified with an air classifier to prepare toner A.

Comparative Example No ethylene-ethyl acrylic copolymer was used. , + 93 parts by weight of resin, 5 parts by weight of carbon black
Sitner B was produced using the same manufacturing process as in the example with a composition of 2 parts by weight and 2 parts by weight of the dye.

The results are shown in Table 1. Toner A with 5 parts by weight of ethylene-acrylic resin added has less toner filming on the carrier surface than Toner B, with drum filming of 50,000 sheets compared to 5,000 sheets of Toner B.
Improved by 0 times.

Table 1 ko'i1. For Toner A and ) Toner B, adjust the developer (toner concentration 3wt%) combined with TSV 1.00/200 (manufactured by Nippon Steel Powder) using carrier, and use F6715D.
A filming test was conducted using a laser printer (Fujitsu Ltd.) under the test conditions shown in Table 2.

Table 2 Development Reversal development with magnetic brush Printing speed 2000 lines/min Photoreceptor-Se drum Initial voltage +550v Fixing method Flash fixing temperature conditions 20-23°C Humidity conditions 35-74° R, I (.

The unmeasured method is to first remove toner particles electrostatically adhered to the carrier surface from the developer using a surfactant, then dry and weigh, and wash with methyl ethyl ketone until the toner color disappears. , dry and weigh again.

The weight loss due to this methyl ethyl ketone cleaning was determined as the amount of toner filming.

Filming occurred on the drum during continuous vertical line printing, and the evaluation was based on the number of sheets printed until the filming image on the drum was offset to the paper.

patent applicant Fujitsu Limited patent application agent Patent attorney Akira Aoki Patent attorney Kazuyuki Nishidate Patent attorney 1) Yukio Patent attorney Akira Yamaguchi

Claims (1)

[Claims] 1. A toner for a powder developer comprising an epoxy compound having at least one epoxy group in one molecule, an ethylene-acrylic copolymer, and a colorant. 2. The toner according to claim 1, wherein 1 to 10 parts by weight of an ethylene-acrylic copolymer is blended with 100 parts by weight of the epoxy compound.