SU932456A1 - Electrophotographic material light-sensitive layer sensitizer - Google Patents

Description

one

The invention relates to the registration of color information - electrophotography, in particular the creation of sensitizers for photosensitive electrophotographic layers.

It is known that 1-electron-accepting substances are effective sensitizers of organic electrophotographic layers, and adding these compounds to poly-N-vinylcarbazole (PVC) or poly-N-epoxypropylcarbazole (PEPC) broadens the spectral sensitivity range of these layers, increases their photosensitivity D.

Fluorenone derivatives have the highest sensitizing activity with respect to carbazole-containing polymers.

Closest to the present invention is the use as a sensitizer for layers based on PVC 2, 7-trinitrofluorenone (TNP) 2.

The maximum sensitivity of this layer corresponds to the half-life of the initial potential of 200300 lx-s (for a layer containing S% TNF). The spectral range of the photosensitivity of the layer is 350 to 650 nm. These layers have unsatisfactory physicomechanical properties: high softening temperature (for a PVC layer - S% TIF) softening temperature is 1tO-l6o), poor adhesion to the substrate surface, the disadvantages of TNF as a sensitizer should also be attributed to the fact that the introduction of large quantities (more than 10%) leads to the formation of a brittle layer due to the crystallization of TNF in a separate phase.

The purpose of the invention is to create a layer sensitizer for electrophotography, the use of which makes it possible to increase the integral sensitivity of the layer, broaden the spectral range of sensitivity, improve the physicomechanical properties of the layers, reduce the softening temperature, and increase adhesion to the substrate. This goal is achieved by using as a sensitizer an organic photosensitive layer of an electrophotographic material of trinitrofluorene containing polymers of the general formula: CHz-cjH-fCHz-dH - o, where m is the mole fraction of the units containing: trinitrofluorenon fragment; n is the degree of polymerization; 1 t 0.1:; The advantage of the proposed trini-. trofluorenon-containing polymers as sensitizers of layers compared to TNF is an increase in the integral sensitivity (exposure half-life of the initial potential of 26-100 lx-s), an expansion of the sensitivity range up to 780 n with better physicomechanical characteristics of the layer: lower softening temperature layer (115-120), high adhesion to the surface of the substrate, the formation of flexible films, the possibility of creating homogeneous elastic films in combination with low molecular weight T-electron donors, for example, anthracene This is not possible with the use of low-molecular electron acceptors, such as TNF. Tests of the proposed compounds | In the electrophotographic mode in the layers show their high efficiency. Layers are obtained by pouring from a solution onto polished aluminum substrates of 20 x 20 mm in size, dried in vacuum at 0–50 ° С for 5 m. The thickness of the layer varies from 2 to 7 microns. The layers are charged with a negative corona with a corona voltage of 5 kV. When tested in integral mode, the illumination is carried out by a incandescent lamp of 100 watts. The following examples illustrate the synthesis of the sensitizer and the electrophotographic properties of the layers with its participation. Example 1 (copolymer of PTIF-V). k, 0k g of polyvinyl alcohol with a medium-viscosity molecular weight of 5.510 (dimethyl sulfoxide, 30 °) in a flat-bottomed flask equipped with a magnetic stirrer, an addition funnel and a reflux condenser is dissolved in 300 ml of dried N, N-dimethyl acetamide (DMAA) 11 ml of dried pyridine was added to the solution. With vigorous stirring, 5 g of 2,5.7-trinitrofluorenon-carboxylic acid chloride, dissolved in 170 ml of DMAA, are added to the solution under a stream of nitrogen. The reaction is carried out for 10 hours at 50. After the completion of the reaction, the polymer is precipitated into isopropyl alcohol and re-precipitated from solution in tetrahydrofuran into isopropyl alcohol three times. Purification quality is controlled by thin layer chromatography of polymer samples. The polymer yield is 43. Elemental analysis,%: C k3, H 3.95; N 7.85. The mole fraction of the units containing the trinitrofluorenone fragment calculated from the content of nitrogen in the copolymer was 2 mol. In the IR spectra of the copolymer, along with the signals corresponding to the hydroxyl group, signals appear in the 1730-1750 region corresponding to the carbonyl groups of fluorenone and ester, as well as signals 1350, 1550, corresponding to nitrogroups. In the UV spectrum of the copolymer, intense absorption appears in the 00nm Region, which is absent in polyvinyl alcohol and corresponds to the absorption of the trinitrofluorenone fragment. Example 2. (copolymer PTNF-2). To 1.61 g of polyvinyl alcohol, dissolved in 1O 1 DMAA under the conditions described in example 1, are added k, k3 ml of pyridine and 1B g of 2.5-chloride of 7-trinitrofluorone-A-carboxylic acid. The reaction is carried out at 50 for 10 hours. After the completion of the reaction, the copolymer is precipitated in isopropyl alcohol in the form of a yellow powder, after which the precipitate is washed with methanol, hexane and hot acetone. Then the copolymer is re-precipitated from solution in 1, A-dioxane (DO) to isopropyl alcohol and washed with acetone. The quality of washing from low molecular weight compounds is controlled by thin layer chromatography. Elemental analysis of the copolymer,%: C 50, tS, H 8.53, N 3 31 The degree of substitution according to the analysis for nitrogen corresponds to 29.1 mol. IR and UV spectra confirm the presence of a trinitrofluorone moiety in the copolymer (see example one). The output of the copolymer Bf2%. Example 3, 0.25 g of PTNF-1 copolymer and PVC are dissolved in 5 ml BEFORE each. The solutions are mixed in different ratios to obtain layers of varying composition. The results of measurements of the integrated photosensitivity of the layers for various POAF and PTNF-1 copolymer are given in Table. t. In tab. 2 shows the spectral distribution of photosensitivity for a layer with a mass ratio of PTNF-1 / PVC 30/70. The tables also show the electrophysical characteristics for the layer described in the prior art. PRI m "e r. According to O, -25 g of PTNF-2 copolymer and PVC are dissolved in 5 ml of DO each. The solutions are mixed in various ratios to obtain layers with varying content of components. The measurement results of the integral electrical photographic sensitivity of the PTNF-2 / PVC layers (thickness of the micron layer) are given in Table. 3 Quality of layers in all cases is good. Example 5. 0.1 g each of PTNF-1 copolymer and anthracene is dissolved in 2 ml of TO each. The solutions are mixed in different ratios to obtain layers with varying contents of the components. The results of measurements of the integra “/ radial electrophotographic characteristics of these layers are given in Table. Thus, the use of n (polymers of Trinitropfluorene-containing polymers as sensitizers in photosensitive electrophotographic layers can significantly increase their integral sensitivity and extend the spectral range of photosensitivity with the best physicomechanical characteristics of the layers. This allows the use of electrophotographic layers, which include the proposed gas sensitizers, as effective substitutes for layers on the basis of selena and its compounds in regis processes radio light information In addition, the proposed Sensi (WHO-5ilizatorami;. Preparation layers can be based on low molecular weight -elektronodonorov Table1.

Note: The quality of the layer is measured by adhesion to the substrate and. - fragility. The layer described in the prototype of the invention. PVK / PTNF-1 10.0 7.6 5.0 3.3 2 1.0 1.8 2.3 1.6, Integral sensitivity of the layers PTNF67 70 120 80 60

Table 2i

Claims (2)

Table 3 2 microns. 2.2 1.2 0.6 0.2 0.06 0, A O00O Table 1 / Anthracene. Thickness of Layer 9: Formula of the invention: Trinitrofluorenon-containing polymers of general formula f. I It -IL t WCHi - CH Jfff 7 / 1- ||| j L Oh OH GvP I gp Jtss. BUT . where m is the mole of the units containing the trinitrofluorenone fragment; 610, 1; p - degree of polymerization, as a sensitizer of an organic photosensitive layer of electrographic material. . Sources of information taken into account in the examination - Schaffert R. M. Ш1, J. of research and development, 1971, 15, N- 1, p. 75-89. 2. US Patent No. H 8 “237, cl. 96-1.5, 1970 (prototype).