DE2357851B2 - 4H-in square bracket to 1,2-square bracket for thiophen-4-one, process for their preparation and electrophotographic light-sensitive material containing them - Google Patents

Description

NO, -

(D

in which R is hydrogen or the nitro group.

2. Process for the preparation of 4H-inden- [1,2-b] thiophen-4-ones of the general formula I according to Claim I, characterized in that (1) a benzoic acid derivative is used in a manner known per se the general formula

NO,

(ID

NO ₁

: oor

in the X chlorine. Bromine or iodine and R _{denotes a C 1} -C ₄ -alkyl radical, with a thiophene derivative of the general formula

(III)

in which X has the above meaning. to a Verbin-4une the allied formula

NO,

-S \

(IVI

40

NO ₁

COOR

Ii the R has the meaning above. (2) this Combination with sodium hydroxide to form a compound of Formula V

NO,

(V)

NO,

COOH

hydrolyzed, the compound of the general formula V with the help of polyphosphoric acid to a compound of the general formula Vl

NO,

An electrophotographic photosensitive material consists of an electrically conductive support with a photoconductive layer thereon. The principle of the electrophotographic process is that there is an electrostatic latent Image is obtained by mar. imagewise exposed a charged photoconductive layer and then the image developed with a developer or toner (in liquid form or in powder form) that is electrically deposited on the latent image to form a visible image.

Usually used to form the photoconductive Layer of inorganic photoconductors, such as photoconductive zinc oxide or selenium, is used. Recently but organic photoconductive compounds such as poly-N-vinylcarbazole are also wounded.

Organic photoconductive compounds are so far advantageous as they are transparent and mechanically flexible.

They can also be easily converted into photo cables Bring in layers. On the other hand, they absorb light in the ultraviolet part of the spectrum but not sensitive to visible light.

To overcome this disadvantage, i. H. about their absorption in the visible part of the spectrum To shift, sensitizers are added to the organic photoconductive compounds.

Such sensitizers are generally not stable or fade quickly, so that the organic photoconductive compounds quickly lose their sensitivity in the visible range. the Solubility of the known sensitizers is particularly in poly-N-vinylcarbazole, which like to be organic photoconductive material is used, low. But that means that the previously known sensitizing compounds, like the one from CR. Acad. Sc. Paris, t. 271, series G. p. 311 known Nitro [2, l - b] thiophene - 8 H - indene, crystallize relatively easily from the light-sensitive material. The consequence of this is that the electrophotographic produced using such sensitizers photosensitive material has a poor shelf life and storage stability.

There is therefore a need for sensitizers. which are particularly soluble in poly-N-vinylcarbazole are.

The invention relates to new 4H-inden- [1,2-b] thiophen-4-ones the general formula

NO,

I Vl)

60

NO,

NO, -,

cyclized and optionally nitrated the compound of the general formula VI.

3. Electrophotographic, photosensitive material, consisting of an organic photo-

in which R is hydrogen or the nitro group.

The compounds of the general formula above

now surprisingly have the property of a

good solubility especially in poly-N-vinylcarbazole.

It is therefore possible to produce electrophotographic photosensitive material using the 4H-indcn [1,2-b] thiophen-4-ones according to the invention, which is distinguished by a long shelf life or great storage stability.
The invention also provides an electrophotographic light-sensitive material. The inventive electrophotographic, photosensitive material consists of an organic photoconductive monomer or polymer on an electrically conductive support material and a sensitizer and is characterized by a content of a 4H-inden [1,2-b] thiophen-4-one of the above general formula I i > marked.

The invention also relates to a process for the preparation of the 4H-indene [!. 2-b] thiophen-4-ones of the general formula 1.

The process is characterized in that (1) a benzoic acid derivative is used in a manner known per se the general formula

NO,

NO,

COOR

in the X chlorine. Bromine or iodine and R is a C ₁ -C ₄ -alkyl resi, with a thiophene derivative of the general formula

The preferred organic photoconductive polymers include poly-N-vinylcarbazole, chlorinated or brominated poly-N-vinyl carbazole. Polyvinyl pyrene. Polyvinyl naphihalin, polyvinyl anthracene. Poly-9-vinyl fluorene, poly-1-arylimidazole and poly-phenylene-1,3,4-oxadiazole.

To preferred organic photoconductive monomers include N-vinyl carbazole. N-athykarbazole. Anthracene and pyrene.

Poly-N-vinylcarbazole and chlorinated or brominated poly-N-vinylcarbazole as organic photoconductive ones Compounds are particularly preferred.

Suitable electroconductive supports are, for example Metal foils such as aluminum foils and synthetic resin foils with an aluminum layer are coated.

Electrophotographic photosensitive materials according to the invention can be produced as follows:

About 0.1 to 1 mole of a 4H-indene [1.2-b] thiophen-4-one according to the general form! 1 is mixed with 1 mole of organic photoconductive monomer or mononier unit of the organic photoconductive polymer and dissolves the mixture in one organic solvent, such as tetrahydrofuran or III-dioxin, and receives a light-sensitive solution.

Polyester resin. Novolak resin or acrylic resin may optionally be added to this solution. Polychlorobiphenyl can also be added to this solution. The resulting photosensitive solution can be applied to a surface of an electroconductive support using, for example, an air knife. They are then allowed to set ⁽ '111 and then dried.

The following examples illustrate the invention.

iii the X has the above meaning. / u a connection the general formula

NO,

NO,

COOR

(IVl

in which R has the above meaning. implements. (2) this Compound with sodium hydroxide / 11 of a compound of the general formula V

NO,

(Vl

NO,

COOH

hydrolyzed, this compound of the general formula V with the help of polyphosphoric acid to a compound of the general formula Vl

NO,

(VIl

NO,

cyclized and optionally the connection of the general Formula VI nitrided.

B e i s ρ i e! 1

A photosensitive solution with a photoconductive one The mixture for forming a photoconductive layer was made up of the following ingredients manufactured:

Poly-N-vinylcarbazole 387 mg (2 mmol)

6,8-dinitro-4H-indene

[l, 2-b] thiophen-4-one 55 mg (0.2 mmol)

Polyester glue 38 mg

Tetrahydrofuran 8.4 g

This photosensitive solution was applied as a coating on an aluminum layer on a polyester resin film (Thickness 75 μ) applied using an air knife, at a distance of 200 α from

ss left to bind and then dried. (SiIicagel was used to evaporate the solvent. Drying 10 minutes at 60 ° C and 2 minutes at 120 ° C.) A photolite layer with a thickness of 13 to 14 μ was on the aluminum layer educated.

The sensitivity of the electrophotographic light-sensitive material was evaluated as follows: The material obtained above was divided into two parts. The photoconductive layer became negative

6s or positive by means of a corona discharge of about -6kV (discharge current: 6 μ Amp.) Or + 6kV (Discharge current: 4 μA) charged for 20 seconds to form a surface electric potential Vdo

and then subjected to a dark ball for 20 seconds, whereby a remaining surface potential Vpo is obtained. This charged photosensitive material was exposed to light using a tungsten filament lamp, the luminosity brf of the surface of the photosensitive layer of which was set to 20 lux. The time (in seconds) required to reduce the surface electrical _{potential to half or V 5 of} the residue surface potential Vpo was determined using an ι ο electrometer. The exposure times, E ¹ Z ₂ (lux sec.) And EV ₅ (lux sec.), Which were required to reduce the surface electrical potential to half or Vs the Vpo, were calculated according to the equation 20 lux χ time (seconds) . The values for E '/ 2 and EV ₅ are representative of the sensitivity of the electrophotographic light-sensitive material. The smaller the value of E ¹ Ii or E ¹ Z ₅ , the higher the sensitivity of the photosensitive material. The values for Vdo, Vpo, E ¹ Z ₂ and E ¹ Zs are given in Table 1 below.

Table I.

Charge Vdo
(V)

1030
+ 960

Vpo
(V)

770
790

E ¹ /, E ¹ ,

(Lux sec.) (L'ix sec.)

26.0
19.7

72.3
49.7

Examples 2 to 5

Table II Poly- 6.8-Di Poly Tetra 2 N-vinyl nitro- ester hydro carbazole 4H- Glue furan 387 mg in the- 58 mg 8.3 g (2 mmol) [1,2-b] - thiophene 4-on 276 mg (1 mmol) Poly- 2,6,8-tri- Poly Tetra 3 N-vinyl nitro- ester hydro carbazole 4H- Glue furan 387 mg in the- 39 mg 6.5 g (2 mmol) [1,2-b] - thiophene 4-on 64 mg (0.2 mmol)

Poly-N-vinylcarbazole
mg
(1 mmol)

2,6,8-tri-

nitro-

4H-

in the-

[1,2-b] -

thiophene

4-on

160 mg

(0.5 mmol)

Polyester glue 30 mg

Tetrahydro furan

Tetrahydro furan 4.1 si

Poly 2,6,8 tri poly

N-vinyl-nitro-estercarbazole 4H- glue

mg indene- 45 mg (1 mmol) [1,2-b] -

thiophene

4-on

321mg

(1 mmol)

Vdo, Vpo, E ¹ and E ₂ Z '' _s of the photosensitive materials 2 to 5 were determined analogously to Example. 1 The values obtained are given in Table III.

Table ΠI

No charge

+
3

Electrophotographic photosensitive materials (2 to 5) were obtained in such a way that one proceeds analogously to Example 1 with the exception that poly-N-vinylcarbazole, polyester adhesive, tetrahydrofuran, 6,8-dinitro-4H-indene [1,2-b] thiophen-4-one and 2,6,8-trinitro-4H-indene [1,2-b] thiophen-4-one were used in the amounts given in Table II below.

40

4-

Vdo
(V)

710
670
880
800
840
740
990
720

Vpo
(V)

560
450
610
640
510
280
640
390

I '

(Lux · Sek.I iLu \ Sek.ι

15.7 15.4 16.9 12.9 10.3 12.6 9.7 25.4

31.4 44.3 48.0 34.6 34.3 36.6 29.1 73.4

45 Examples 6 to 9

Electrophotographic Photosensitive Materials 6 to 9 were obtained in the manner

so that one proceeded as in Example 1 with the exception that chlorinated or brominated poly-N-vinylcarbazole, Polyester glue 49,000, tetrahydrofuran and 2,6,8-trinitro-4H-indene [1,2-b] thiophen-4-one in the amounts given in Table IV were used.

Table IV 2,6,8-tri- Poly Tetra 6 chlorinating nitro- ester hydro tes poly 4H- Glue furan N-vinyl in the- 48 mg 4.4 g carbazole ¹ ) Ll, 2-b] - 228 mg thiophene (1 mmol) 4-on 321 mg (1 mmol)

continuation

7th chlorinating 2,6,8-tri- Poly Tetra tes poly- nitro- ester hydro N-vinyl 4H- Glue furan carbazole ¹ ) in the- 34 mg 3.8 g 228 mg [1,2-b] - (1 mmol) thiophene 4-on 161 mg (0.5 rnMo!) brominating 2,6,8-tri- Poly Tetra tes poly- nitro- ester hydro N-vinyl 4H- Glue furan carbazole ¹ ) in the- 48 mg 4.4 g 233 mg [1,2-b] - (1 mmol) thiophene 4-on 321mg (1 mmol)

brominated poly-N-vinylcarbazole ² )
233 mg
(1 mmol)

2,6,8-tri-

nitro-

4H-

in the-

[1,2-b] -

thiophene

4-on

161 mg

(0.5 mmol)

polyester
Glue
34 mg

Tetrahydro
furan

3.1g

') Chlorine is in the ratio of one chlorine atom per monomer Unit contain poly-N-vinylcarbazole.

² ) Bromine is contained in a ratio of one bromine alom per two monomeric units of poly-N-vinylcarbazole.

Vdo, Vpo, E ¹ Z ₂ and E ¹ Z _{5 of} the light-sensitive materials 6 to 9 were determined analogously to Example 1. In this case, the photosensitive materials were only negatively charged. The values obtained are given in Table V.

Dissolved dimethylformamide and heated the solution to a temperature of 70 ^{° C.} 20 g of active: copper powder (prepared according to the process described in the Journal of American Chemical Society, vol. 55, p. 4219 [1933]) were added to this solution within 10 minutes; the solution was stirred at a temperature of 70 ° C. for 50 minutes. After cooling, the reaction product was poured into 500 ml of cold water. The precipitate obtained in this way was filtered off and washed with water. After the water had been separated from the precipitate the precipitate was added to 500 ml of acetone. When the stirring was complete, the solution was filtered. The fillerate was treated with activated charcoal and then filtered. The filtrate was then condensed to obtain a crude product. 13.1 g of yellowish crystalline powder (melting point 134 to 135) were obtained ° C.) in 85% yield after recrystallization from ethyl alcohol.This product was methyl 2-i / -thienyl-3,5-dinitrobenzoate.

Analysis for C ₁₂ H ₈ N ₂ O ₆ S:

Calculated ... C 46.75, H 2.61, N 9.09, S 10.41;
found .... C 46.86, H 2.60, N 9.02, S 10.61.

The presence of the carbonyl group was detected by the IR spectrum at 1730 cm " ^1.

23.6 g of methyl 2-a-thienyl-3,5-dinitrobenzoate thus obtained were dissolved in 100 ml of dioxane and this solution was added to an aqueous solution of NaOH (6 g of NaOH in 200 ml of water) and stirred for 3 hours. A small amount of activated charcoal was added to this solution and the solution was filtered. Cold water was added to the filtrate, and the filtrate was neutralized with 6N HCl with cooling to obtain a yellowish crystalline product. The crystalline product was filtered off, washed with water and then dried. The crude product (melting point 171 to 172 ° C.) was obtained in a yield of 21 5 g. The yellowish crystalline product (mp 172.5 to 173.5 ° C.) was obtained after recrystallization from benzene. This product was 2- ₍ /- thienyl-3.5- dinitrobenzoic acid.

Table V Vdo Vpo EV ₂ EV ₅ charge (V) (V) (Lux sec.) (Lux sec.) 790 560 9.1 32.0 6 - 910 680 10.3 35.1 7 - 1080 760 10.6 33.5 0 1170 860 13.4 35.5 9 -

Analysis for C _n H ₆ N ₂ O ₆ S:

Calculated ... C 44.90, H 2.06, N 9.52, S 10.90;
found .... C 44.65, H 2.10, N 9.65, S 10.72.

Electrophotographic photosensitive materials having sensitivity to visible Light can be produced with organic photoconductive compounds which in themselves have no sensitivity to visible light.

Manufacture of 6,8-dinitro

4H-indene [l, 2-b] thiophen-4-one and 2,6,8-trinitro-

4 H-indene [1,2-b] thiophen-4-one

13 g (0.05 mol) of methyl 2-chloro-3,5-dinitrobenzoate (temperature: 193 to 196 ° C) and 21 g (0.1 mol) of 2-iodothiophene (boiling point 71 to 73 ° CZ16 torr) were in 100 ml The presence of the carbonyl and hydroxyl groups was detected ^{by the IR spectrum at 1730 and 3000 cm "1, respectively.}

To 2 g of 2-a-thienyl-3,5-dinitrobenzoic acid was added 60 g of polyphosphoric acid, and the mixture was heated at a temperature of 130-140 ⁰ C. After cooling, the reaction mixture was poured into 200 ml of cold water. The precipitate thus obtained was filtered off and washed with a solution of sodium carbonate and water and then dried. 18 g of crude product (mp 206 ° to 207.5 ° C.) were obtained in 95% yield. The orange-brownish crystalline product (mp 209.5 to 210.0 ° C.) was obtained after recrystallization from tetrahydrofuran. This product was 6,8-dinitro-4H ~ inden- [1,2-b] thiophen -4-one.

Analysis for C _n H ₄ N ₂ O ₅ S:

Calculated ... C 47.83, H 1.46, N 10.11, S 11.61;
Found .... C 47.65, H 1.57, N 10.01, S 11.62.

The presence of the carbonyl group was detected by the IR spectrum at 1730 cm " ^1.

1.5 g of 6,8-dinitro-4H-indene [l, 2-b] thiophen-4-one was dissolved in 30 ml of concentrated H ₂ SO ₄ . solved. To this solution was added dropwise within 30 minutes with stirring 5 ml of HNO ₃ (sp. Gravity: 1.38) at a temperature of from 5 to 1O ⁰ C. Stirring was continued for 1.5 hours at this temperature. This solution was poured into 200 ml of cold water. A yellowish crystalline product was separated from the solution. The crude product was filtered off, washed with water and then dried. 1.4 g of yellowish needle-like crystalline product (F. 223

to 223.5 ° C) was obtained in 80.5% yield after recrystallization from dioxane-ethyl alcohol. This product was 2,6,8-trinitro-4H-indene [1,2-b] thiophen-4-one.
5
Analysis for C _n H ₃ N ₃ O ₇ S:

Calculated ... C 41.16, H 0.93, N 13.08, S 9.98; found .... C 40.90, H 1.32, N 12.90, S 10.23.

ίο The presence of the carbonyl group was detected ^{by the IR spectrum at 1730 cm "1.}

Claims (1)

Patent claims: I. 4H-inden [1,2 b] thiophen-4-ones of the general formula NO, Conductive monomer or polymer on one electroconductive carrier material and a sensitizer, characterized by a content of a 4H-inden [1,2-b] thiophen-4-one according to claim 1.