SU987566A1 - Electrographic toner - Google Patents

Description

one

This invention relates to electrography, namely, to dry electrographic toners used to visualize latent electrostatic images on photoconductive layers,

Electrographic toner is known for producing latent electrostatic images containing solid epoxy resin, a dye pigment, and an organic dye l j as a binder.

However, in the known toner, the developed image is not completely transferred from the electrophotograph to the perceiving surface, as a result of which copies have insufficient optical density

The purpose of the invention is to improve the performance properties of the electrographic toner.

In order to achieve the supplied circuit, the electrographic toner for producing

A lazy electrostatic image that contains solid epoxy resin as a binder, a dyeing pigment and an organic dye, additionally contains a polyester resin in the following ratio, wt.%: Solid epoxy resin. 70-85 Polyester resin 5-15

10 Dye pigment 6-12 Organic dye1-5 The introduction of a polyester resin, which combines well with the main component of the toner (epoxy resin), allows to increase the transfer coefficient of the powder image from the electrophotometer to the perceived

20 surface, thereby increasing the quality of the copies.

In addition, the proposed toner is capable of maintaining its efficiency, i.e. When developing, give a high-quality image with maximum resolution, good graphical density. This is due to the fact that the toner does not agglomerate and does not clog during storage. It does not migrate, its triboelectric properties do not change during storage. At the same time, the polyester resin ensures uniform distribution of the organic dye in the binder of the toner {epoxy resin), and, therefore, the required triboelectric properties.

. In the present invention, instead of low molecular weight compounds (alkyl esters, aryl amides of phthalic, benzoic and other acids, polyester resin is introduced into the toner in an amount of 5-15 wt.% |,

In tab. 1 shows the formulations of the toner obtained according to the invention.

The proposed toner is obtained by preliminary mechanical mixing of the calculated amount of the components until a homogeneous mass is formed. Then the mass is passed through an extruder.

G (ri 140-150 ° C., The melt is cooled, melted and classified according to particle size. The resulting toner can be used to work in equipment with various methods of development (for example, dust, cascade, magnetic brush).

The content of toner in the developer when developing with a magnetic brush or cascade method is 2-5% of the mass of the developer.

The properties of the proposed toners in comparison with the known are given in table 2. The toner is used in combination with magnetic media 0101 (TU 06292-79).

From the data given in Tables T and 2, it can be seen that the proposed toner, having the triboelectric properties of a known toner, has a higher transfer coefficient, as a result of which the copy quality is improved (their optical density increases and the photoconductor layer is cleared of residual powder image after repeated use. In addition, the proposed toner compared with the known much longer

maintains its performance. one

Table 1

Epoxy resin

E-05K

Epoxy resin EPOLIETHER RESIN i | -35n-71

Fat soluble indinin

Alcohol soluble Nigrosine

Soot. Dimethylmetaphthalate

77

83

85 6

5 11

3 2

2 7

12

table 2

Claims (1)

The claims ^υ Electrographic toner for developing electrostatic latent images, comprising as a binder a solid epoxy resin, a coloring pigment and the organic Kramers Sitel ^45, characterized in that, in order to improve its performance, it additionally contains a polyester resin at the following ratio of components ⁵⁰ comrade , wt.%: Solid epoxy resin 70-85 Polyester resin 5-15 Pigment coloring 6-12 Organic Beauty sifel 1-5