CA1064969A

CA1064969A - Organo-chalcogen compositions

Info

Publication number: CA1064969A
Application number: CA213,827A
Authority: CA
Inventors: Wolfgang H.H. Gunther
Original assignee: Xerox Corp
Current assignee: Xerox Corp
Priority date: 1973-12-13
Filing date: 1974-11-15
Publication date: 1979-10-23
Also published as: NL7416314A; GB1478870A

Abstract

ABSTRACT OF THE DISCLOSURE
Photoconductive composition comprising an organo-chalcogen polymer of the formula:
?Se - A - Se - Tem?n wherein A is a member selected from the group consisting of an alkylene radical having from about 9 to about 20 carbon atoms, a divalent aromatic radical having from about 6 to about 50 carbon atoms and a divalent heterocyclic radical;
m is at least 1; and n is at least 2.
-or-?B - Sea-x - Tem - Sex?b wherein B is a member selected from the group consisting of divalent hydrocarbylene radicals and divalent heterocyclic radicals;
a is a positive integer of at least 2;
x is a positive integer of at least 1 but less than a;
m is a positive integer in excess of 1; and b is a positive integer in excess of 1.
This composition possesses enhanced spectral response and electrophotographic speed over compositions containing selenium alone. Compositions of this type are, thus, especially suitable for use in high speed electrophotographic imaging systems wherein rapid cycling of the photoresponsive member is essential.

Description

1064g69 BACXGROIJND OF THE INVENTION
Field of the Invention This invention relates to a photoconductive composition, articles prepared from this composition and methods of use of said articles. More specifically, this invention involves organo-chalcogen compositions, electrophotographic imaging members wherein the photocohductive insulating layer comprises an organo-chalcogen composition, and an electrophotographic imaging process employing said imaging member.
Description of the Prior_Art. The formation and development o~ images on the imaging surfaces of photoconduc~ive materials by electrostatic means is well known. The best known of the commercial processes, more commonly known as xerography, involves forming a latent electrostatic image on the imaging layer of an imaging member by first uniformly electrostati~ally charging the surface of said layer and then exposing this electrostatically charged surface to a light and shadow image. The light struck areas o the imaging layer are thus rendered conductive and the electrostatic charge selectively dissipated in these irradiated areas. After the photoconductor is exposed, the latent electrostatic image on this image bearing layer i~ rendered visible by development with a inely divided colored electroscopic material, known in the art as "toner".
This toner will be principally attracted to those areas on the sur~ace of the ima~ing layex which retain the electrostatic charge and thus render visible the latent image.
~ he developed image can then be read or permanently afixed to the photoconductor where the imaging surface is ~ot to be reused. This ~atter practice is usually followed with respect to the binder type photoconductive fil~s (e.g. zinc oxide -4- ~

13~64~69 pi~ment disperse~ in a film forming insulating resin) where'the photoconductive imaging layer is also an integral part of the finished copy.
In so-called "plain paper~ copying systems, the latent image can be developed on a reusable photoconductive layer or transferred to another surfaee, such as a sheet of paper, and thereafter developed. When the latent image is developed on the imaging surface of a reusable photoconductive layer, it is subsequently transferred to another substrate and then permanently afixed thereto. Any one of a variety of well known techniques can be used to permanently affix the toner image to the copy sheet, including overcoating with transparent films, and solvent or thermal fusion of the toner particles to the supportive substrate.
In the above "plain paper" copying systems, the materials used in the photoconductive layer should preferably be capable of rapid switching from insulative to conductive to insulative state in order to permit cyclic use of the imaging layer. The failure of a material to return to its relatively insulative state prior to the succeeding charging sequence will result in an increase in the rate of dark decay of 'the photoreceptor. This phenomenon, commonly re~erred to in the art as "fatigue", has in the past been avoided by the selection of photoconductive materials possessing rapid switching capacity.
~ypical of the materials suitdble for use in such a rapidly cycling imaging system inc}ude anthracene, sulfur, selenium '-and mixtures thereof (U. S. Patent 2,297,691); selenium being preferred because of its superior photosensitivity.
In order to further enhance the spectral range and/or electro-.

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~LO~ii4~9 photographic response of selenium, selenium has been alloyed with materials such as tellurium and arsenic, U. S. Patents 2,745,327 (Te/Se); and 2,803,542 (As/Se); 2,822,300 (~s/Se); 3,312,54 (As/Se ~ halogen).
Although selenium and selenium alloys probably are the most desirable materials from which to fashion the imaging layer of a photoconductive imaging member, imaging layers of these materials do have some serious physical limitations.
For example, imaging layers of amorphous selenium and selenium alloys are sensitive to abrasion. Moreover, the adhesion of vaccuum deposited selenium on many of the conductive substrates used in electrophotography is relatively poor. Poor adhesion of imaging layers prepared from such materials does not, however, cause impairment of the 1ntegrity of the imaging member so long as the conductive substrate bearing this imaging layer i5 inflexible. Recently, there has been increasing interest in the use of flexible photoconductors due to the greater freedom in machine design and increased speed in copier through-put permitted by the use of such flexible imaging members.
Unfortunately, because of the briktle nature of amorphous selenium and s~lenium alloy imaging layers, coupled with relatively poor adhesion to most conventional conductive 9ubstrates, such materials do not readily lend themselves to ~abrication of flexible imaging members since repeated flexure of the member can result in cracking and separation o~ the imagitlg layer from the conductive substrate.
. One technique suggested for the resolution of this problem is the provision of an interfacial layer intermediate between the conductive substrate and an imaging layer of amorphous selenium or selenium alloy, U. S. patent 3,713,821 . .

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and 3,677,467. These interfacial layers reportedly provide improved adhesion between the imaging layer and the conductive substrate. The interlayer disclosed in '467 comprises a poly-meric seleno-organic material having recurring units of the formula ~

~Se - A - Se~ I

wherein A is a member selected from the group consisting of an alkylene radical having from 9 to 50 carbon atoms, a divalent ; aromatic or a substituted aromatic radical having from 6 to 50 carbon atoms and heterocyclic radicals.
. -or-..
~B - Sea~b II
~, , ` ' . .
wherein B is a member selected from the group consisting of a divalent hydrocarbylene radical and a divalent heterocyclic radical;
. . .
a is a positive integer of at least 3; and b is a positive integer greater than 1.
Although many of the polymers having recurring units ~f formula I and all of the polymers having recurring units of formula II are reportedly intrinsically photoconductive, the spectral response and electrophotographic speed of such materîals is somewhat limited.

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By one aspect of the present invention there is provided an organo chalcogen composition comprising recurring units of the formula tSe - A - Se - Te tn wherein A is a member selected from the group consisting of an alkylene radical having from about 9 to about 20 carbon atoms, a divalent aromatic radical -having from about 6 to about 50 carbon atoms and a divalent heterocyclic radical; m is at least l; and n is at least 2.
By another aspect of the.present invention there is provided an electrophotographic imaging member comprising a conductive substrate having operatively disposed in relation to at least one surface thereof a photoconductive insulating layer comprising recurring units of the formula tSe - A -Se - Te~tn wherein A is a member selected from the group consisting of an alkylene radical having from about g to about 20 carbon atoms, a divalent aromatic radical having from about 6 to about 50 carbon atoms and a divalent heterocyclic radical; m is at least l; and n is at least 2.
By yet another aspect of the invention there is provided an organo chalcogen composition comprising recurring units of a-x Tem ~ Sextb wherein B is a member selected from the group consisting of a divalent hydrocarbylene radicals and divalent heterocyclic radicals; a is a positive integer of at least 2; x is a positive integer at least 1 but less than a; m is a positive integer in excess of l; and b is a positive integer in excess of 1.
By still another aspect of the present invention there is provided an electrophotographic imaging member comprising a conductive substrate having operatively disposed in relation to at least one surface thereof a photoconductive insulating layer comprising recurring units of the formula tB - Sea x Tem ~ Sextb wherein B is a member selected from the group consisting of divalent hydrocarbylene radicals and divalent heterocyclic ~ -8-1!D64969 radicals; a is a positive integer of at least 2; x is a positive integer of at least 1 but less than a; m is a positive integer in excess of l; and b is a positive integ~r in excess of 1.
Yet another aspect of the present invention there is provided a method for controlling the photoresponsiveness of compounds ~
S e wherein R is selected from divalent hydrocarbylene radicals of from 5 to 50 carbon atoms, divalent heterocyclic, alicyclic and aromatic radicals having from 3 to 50 àarbon atoms; n is a positive integer; and x is the radical -Se-R-Se-; or linear polymers comprising recurring units represented by the ormula:
~Se - A - Set wherein A is selected from the group consisting of divalent alkylene radicals having at from 9 to 20 carbon atomsj divalent aromatic radicals having from 6 to 50 carbon atoms and divalent heterocyclic radicals -or~ ~B - Sea)b wherein B is selected from the group consisting of divalent hydrocarbylene radicals and divalent heterocyclic radicals, a is a positive integer of at least 3 and b is a positive integer greater than 1 comprising fusion an intimate mixture o~ said compounds and tellurium.
SUMMARY OF TIIE INVEN'rION
-The above and related aspects may be achieved by providing an oryano-chalcogen photoconductive composition comp-rising a polymer having recurring units of the formula:

-8a-49~;9 ~se - ~ - se - Temtn wherein A is a member selected from the group consisting of an alkylene radical having from about 9 to about 20 carbon atoms, a di~alent aromatic radical having from about 6 to about 50 carbon atoms and a divalent heterocyclic radical; t m is at least l; and n is at least 2.
-or-~B - Sea_x ~ Tem ~ Sex~b w~erein B is a member selected ~from the group consisting of a divalent hydrocarbylene radical and a divalent heterocyclic radical a. is a positive integer of at least 2;
x is a positive integer of at least 1 but less than a: .
m is a positive integer in excess o~ l; and b i9 a posi~ive integer in excess of 1.
DESCRIPTION OF THE INVENTION
XNCLUDXNG P~EE'ERRED EMBODIMENTS
The polymeric organo-chalcogen compositions of this invention can be prepared by fusing an intimate mixture of tellurium with at least one o~ the compounds having the following formulae:

"R~
. ~ ~ e \ X / III

1a~6~96~ I

wherein.R is selected ~rom divalent hydrocarbylene radicals of from 5 to 50 carbon atoms, divalent heterocyclic, alicyclic and aromatic radicals having from 3 to 50 carbon atoms;
n is a positive intege~ and X is the radical -Se-R-Se-; or linear polymers comprising recurring units represented by the formula:

~Se - A - Se~ I

wherein A is selected from the group consisting of divalent alkylene radicals having at ~rom 9ito 20 carbon atoms, divalent aromatic radicals having from 6 to 50 carbon atoms and divalent heterocyclic radicals or-, .
~ B - Seatb II
;~ ~
wherein B is selected irom the group consisting of divalent h~drocarbylene radicals and divalent heterocyclic radicals, a is a positive integer of at leas`t 3 and b is a positive integer greater than 1.
Subsequent to introduction o~ tellurium into the polymer backbone, said polymer can be cast or coated on an appropriate ~pre~erably flexible) substrate. Alternatively, the polymeric LO- ' ' ::
'~ .

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chalcogen composition can be formed directly on the substrate and once in the molten state evenly spread so as to provide a layer of substantially uniform thic~ness.
Compounds I and III can be prepared by reacting a difunctional organic compou~d of the formula:
, Y - D - Y

wherein D is selected from a member of the group consisting of a divalent hydrocarbylene . and a divalent heterocyclic radical, and Y is readily displaceable member selected from the group co~sisting of halides, epoxy or sulonate esters and diazonium halides in which both reac~ive sites are capable of forming a covalent bond with a molecule con~aining a diselenide (-Se - Se -) precursor. Represe~tative diselenide precursors include bis(selenosulfate), bis(selenocyanate), bis(selenols), and bis~selenoesters). Compound II can be prepared simply by fusion of elemental selenium with compound I and III
wherein the organic divalent radicals R and A o~ said compounds are de~ined as the divalent radical B o~ compound II. .
Com,pounds I, II and III used in preparation of the organo~chalcogen compo~itions of this invention are disclosed and methods for their preparation described in U. S. patent 3,67~,467, 'Preliminary to forming a melt from the tellurium ~h~reinafter al~o referred to as "i~organic .

:~IL064969 ingredient") with one or more of compounds I, II and III
(hereinafter also referred to as ~organic ingredients"), the ingredients of the melt are physically ground toge~her until ormation of an intimate admixture therebetween. Ordinarily, the relative concentration of inorganlc ingredients to organic ingredients in such admixture can range from about 1:1 to about 12:1. The conductive substrate upon which such polymer is coa~ed or formed can be almost virtually any of the materials presently in use in electrophotographic imaging members, provided such materials are thermally stable at temperatures required to render the organo-chalcogen composition molten. In organo-chalcogen compositions having relatively low loadings of inorganic materials, traditional solvent casting techniques can be used in forming photocon-ductive ~ilms from such compositions. With regard to these latter materials, the thermal stability of the substrate is not a critical feature, thus, enabling use of many of the conductive substrates, such as plastics and paper, traditionally used in formation of electrophotographic imaging members.
The amount of polymeric organo-chalcogen composition imparted to said substrate should be suf~icient to provide a substantial uniform layer having a dry ~ilm thickness o~
from about 1 to about 200 microns. The ability to incor-porate tellurium into organo-selenium polymers provides a unique method for reducing the rate o~ dark dis~harge of tellurium while simultaneously increasing the rate of light discharge and range of spectral response of organo-selenium polymers. The organo-chalcogen polymeric composition resulting ~rom the introduction of tellurium into organo-selenium polymers is a highly responsive photoconductor having excellent adhesion to flexible conductive substrates and is also suitable~in providing an adhesive rectifying interface ' 3' between a photoconductive insulating layer of selenium or selenium alloy and such conductive substrate.
- In another embodiment of this invention, the organ~o-chalcogen composition can be employed as a binder for other photoconductive pigments. A number of the organo-chalcogen comp~sitions of this invention possess extensive aromatic functionality and are, thus, capable of rapid and efficient transport of charge carriers generated within the bulk of this material. Any one of a number of photoconductive pigments can be dispersed in the polymeric organo-chalcogen composition of this invention and the resulting dispersion cast or coated on a conductive substrate. The relative concentration of such pigment within the organo-chalcogen binder will vary depending upon its carrier generating efficiency and the degree of aromatic ~unctionality of the organo-chalcogen binder. In the preferred binder-photoconductive insulating layer systems o~ this invention, the photoconductive pigment is primarily responsive to acti-vating electromagnetic radiation beyond the range of sub-stantial photoresponse o~ the organo-chalcogen binder and the organo-chalcogen binder has a high degree o~ aromatic functionaIity. In such a pre~erred system, the concentra-tion of photoconductive pigment generally need not exceed about 10 weight percent in order to provide a photoconductive composition having satis~actory electrophotographic speed.
In yet another alternative embodiment, this polymeric organo chalcogen composition can be overcoated .

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on a photoconductive insulating layer. The favorable charge transport properties of this material permits separation of carrier generation and transport functions in the same manner described above. Moreover, because of the superior durability of these polymeric chalcogen compositions, they can provide a hiyhly effective abrasion resistant shield for some of the more abrasion prone photoconductive insulating layers.
The Examples which follow further define, describe and illustrate preparation and use of the polymeric organo-chalcogen compositions of this invention. Techniques and apparatus used in preparation and evaluation of such com-positions are standard or as hereinbefore described. parts and percentages appearing in such Examples are by weight unless otherwlse stipulated.

~XAMPLE I
, About 1.5 parts tellurium ana 0.5 parts m-xylene-d~ diselenide cyclic dimer are placed in a mortar cavity and ground together into a fihe powdery mixture with a pestle.
This powder is transferred to the surface of a ball grained aluminum plate and the plate gradually heated to about 250C
until the powdery mix~ure becomes uniformly mo1ten. This melt is then evenly distributed on the surface of the plate with the assistance of a glass rod. This plate is rapidly cooled to avoid crystallization of the molten coating by contacting the uncoated surface of the aluminum plate with a heat sink. Upon cooling, the photoelectric properties of the dark red homogenous argano chalcogen coating are evaluated by simply charging the coating , ~064969 in the dark to a positive potential by means of a Xerox Model D
processor followed by bLanket exposure of the sensitized surace of the coating with a 100 Watt incandescent lamp from a distance o 20 centimeters. Substantially complete discharge of the plate is observed within less than 15 seconds from the onset of such exposure. Repeated charging and blanket exposure of the plate gave the following recorded voltage drops:

2 540 540

3 530 530

4 540 540 The above data demonstrate the good cycling capacity of the photoconductive insulating layers prepared ~rom the polymeric organo chalcogen composition of this Example.
The organo chalcogen coating is again sensitized as described above and exposed to image information through a Xerox Model A camera at f/10, ~exposure time 7.5 seconds). The lakent ; - 15 -~6~L96~

image thus produced is developed by cascading X~rox 2400 toner and carrier onto the imaging bearing surface of the plate, the toner image trans~erred to a sheet of paper and fused thereto. The plate is then fully discharged and cleaned of residual toner, where-upon the imaging/development procedure is repeated for several addi-tional cycles; the only variation being the extension of the ex-posure time from 7.5 seconds up to about 60 seconds. Print quality is acceptable in each instance and some slight decrease in contrast is noted as the exposure time become more prolonged, apparently due to change of the latent image contrast. Comparison of the photoresponse of this organo-chalcogen coated plate with a standard selenium plate indicates that both plates are substantially equiv-alent (optimum print quality for the selenium plate re~uiring ex~
posure at ~/16 for 12 seconds).
EXAMPLE II
An organo-chalcogen composition is prepared rom equal parts tellurium and poly(para phenylene) diseLenide in the same manner described in Example I. Evaluation of cycling and imaging capability yields results comparable to those reported in Example 1~ .
, ~X~PI,E~lII
An organo-chalcogen composition is prepared from equal parts tellurium and poly(l,4-napthalenej diselenide in the same manner described in Example I. Evaluation of cycling and imaging capability yields results comparable to those reported in Exam~le I.

.

,, _ _ , , .

EXAMPLE IV
An organo-chalcogen composition is prepared from equal parts tellurium and poly(9,10-anthracene) diselenide in the same manner described in Example I. Evaluation o~ cycling and imaging capability yields results comparable to those reported in Example I.

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..... , ,.. ~ . . .. .. . . . . _ _

Claims

WHAT IS CLAIMED IS:

1. An organo chalcogen composition comprising recurring units of the formula ?Se - A - Se - Tem?n wherein A is a member selected from the group consisting of an alkylene radical having from about 9 to about 20 carbon atoms, and a divalent aromatic radical having from about 6 to about 50 carbon atoms;

m is at least 1; and n is at least 2.

2. The composition of Claim 1, wherein A is a divalent aromatic radical.

3. The composition of Claim 1, wherein A is a divalent radical of benzene.

4. The composition of Claim 1, wherein A is a divalent radical of xylene.

.

5. A composition of Claim 1, wherein A is a divalent radical of naphthalene.

6. The composition of Claim 1, wherein A is a divalent radical of anthracene.

7. An electrophotographic imaging member comprising a conductive substrate having operatively disposed in relation to at least one surface thereof a photoconductive insulating layer comprising recurring units of the formula ?Se - A - Se - Tem?n wherein A is a member selected from the group consisting of an alkylene radical having from about 9 to about 20 carbon atoms, and a divalent aromatic radical having from about 6 to about 50 carbon atoms;

m is at least 1; and n is at least 2.

8. The imaging member of Claim 7, wherein A is a divalent aromatic radical.

9. The imaging member of Claim 7, wherein A is a divalent radical of benzene.

10. The imaging member of Claim 7, wherein A is a divalent radical of xylene.

11. The imaging member of Claim 7, wherein A is a divalent radical of napthalene.

12. The imaging member of Claim 7, wherein A is a divalent radical of anthracene.

13. An electrophotographic imaging member comprising a conductive substrate, a photoconductive insulating layer com-prising selenium or selenium alloy and an adhesion promoting barrier layer disposed intermediate between the conductive sub-strate and the photoconductive insulating layer, said adhesion promoting layer comprising an organo chalcogen composition having recurring units of the formula ?Se - A - Se - Tem?n wherein A is a member selected from the group consisting of an alkylene radical having from about 9 to about 20 carbon atoms, and a divalent aromatic radical having from about 6 to about 50 carbon atoms;

m is at least 1; and n is at least 2.

14. The imaging member of Claim 13, wherein A is a divalent aromatic radical.

15. The imaging member of claim 13, wherein A is a divalent radical of benzene.

16. The imaging member of Claim 13, wherein A is a divalent radical of xylene.

17. The imaging member of Claim 13, wherein A is a divalent radical of napthalene.

18. The imaging member of Claim 13, wherein A is a divalent radical of anthracene.

19. An organo chalcogen composition comprising recurring units of the formula ?B - Sea-x - Tem - Sex?b wherein B is a divalent hydrocarbylene radical;

a is a positive integer of at least 2;
x is a positive integer at least 1 but less than a;
m is a positive integer in excess of 1; and b is a positive integer in excess of 1.

20. The composition of Claim 19, wherein B is a divalent aromatic radical.

21. The composition of claim 19, wherein B is a divalent radical of benzene.

22. The composition of Claim 19, wherein B is a divalent radical of xylene.

23. THe composition of claim 19, wherein B is a divalent radical of napthalene.

24. The composition of Claim 19, wherein B is a divalent radical anthracene.

25. An electrophotographic imaging member comprising a conductive substrate haying operatively disposed in relation to at least one surface thereof a photoconductive insulating layer comprising recurring units of the formula ?B - Sea-x-Yem - Sex?b wherein B is a divalent hydrocarbylene radical;

.

a is a positive integer of at least 2;
x is a positive integer of at least 1 but less than a;
m is a positive integer in excess of 1; and b is a positive integer in excess of 1.

26. The imaging member of Claim 25, wherein B is a divalent aromatic radical.

27. The imaging member of Claim 25, wherein B is a divalent radical of benzene.

28. The imaging member of Claim 25, wherein B is a divalent radical of xylene.

29. The imaging member of claim 25, wherein B is a divalent radical of napthalene.

30. The imaging member of Claim 25, wherein B is a divalent radical of anthracene.

31. An electrophotographic imaging member comprising a conductive substrate, a photoconductive insulating layer com-prising selenium or selenium alloy and an adhesion promoting barrier layer disposed intermediate between the conductive sub-strate and the photoconductive insulating layer, said adhesion promoting layer comprising an organo chalcogen composition having recurring units of the formula ?B - Sea-x - Tem - Sex?b wherein B divalent hydrocarbylene radical;

a is a positive integer of at least 2;
x is a positive integer of at least 1 but less than a;
m is a positive integer in excess of 1; and b is a positive integer in excess of 1.

32. The imaging member of Claim 31, wherein B is a divalent aromatic radical.

33. The imaging member of Claim 31, wherein B is a divalent radical of benzene.

34. The imaging member of Claim 31, wherein B is a divalent radical of xylene.

35. The imaging member of Claim 31, wherein B is a divalent radical of napthalene.

36. The imaging member of Claim 31, wherein B is a divalent radical of anthracene.

37. A method for controlling the photoresponsiveness of tellurium comprising fusion of intimate mixture of tellurium with at least one compound of the formula:

wherein R is selected from divalent hydrocarbylene radicals of from 5 to 50 carbon atoms, alicyclic and aromatic radicals having from 3 to 50 carbon atoms;
n is a positive integer; and X is the radical -Se-R-Se-; or linear polymers comprising recurring units represented by the formula:

?Se - A - Se? I

wherein A is selected from the group consisting of divalent alkylene radicals having at from 9 to 20 carbon atoms, and divalent aromatic radicals having from 6 to 50 carbon atoms.

38. The method of Claim 37, wherein the relative weight ratio of tellurium to cyclic diselenide in the intimate mixture can range from about 1:1 to about 12.1.

39. A method for controlling the photoresponsiveness of tellurium comprising fusion of an intimate mixture of tellurium with at least one compound of the formula:

?B - Sea?b wherein B is a divalent hydrocarbylene radical;

a is a positive integer of at least 3 and b is a positive integer greater than 1.

40. The method of Claim 45, wherein the relative weight ratio of tellurium to polyselenide in the intimate mixture can range from about 1:1 to about 12:1.

41. A method for controlling the photoresponsiveness of tellurium comprising fusion of an intimate mixture of tellurium with at least one compound of the formula selected from the group;

wherein R is selected from divalent hydrocarbylene radicals of from 5 to 50 carbon atoms, alicyclic and aromatic radicals having from 3 to 50 carbon atoms;
n is a positive integer; and X is the radical -Se-R-Se-; or linear poly-mers comprising recurring units represented by the formula:

?Se - A - Se?

wherein A is selected from the group consisting of divalent alkylene radicals having at from 9 to 20 carbon atoms, and divalent aromatic radicals having from 6 to 50 carbon atoms - and -?B - Sea?b wherein B is a divalent hydrocarbylene radical;

a is a positive integer of at least 3 and b is a positive integer greater than 1 comprising fusion an intimate mixture of said compounds and tellurium.
.

42. The method of Claim 41, wherein the relative weight ratio of tellurium to the above compounds in said intimate mixture can range from about 1:1 to about 12:1.

43. An organo chalcogen composition comprising recurring units of a formula selected from the group;

?Se - A - Se - Tem?n wherein A is a member selected from the group consisting of an alkylene radical having from about 9 to about 20 carbon atoms, and a divalent aromatic radical having from about 6 to about 50 carbon atoms;
m is at least 1; and n is at least 2.

- and -?B - Sea - x - Tem - Sex?b wherein B is a divalent hydrocarbylene radical;
a is a positive integer of at least 2;
x is a positive integer at least 1 but less than a;
m is a positive integer in excess of 1; and b is a positive integer in excess of 1

44. An electrophotographic imaging member comprising a conductive substrate having operatively disposed in relation to at least one surface thereof a photoconductive insulating layer comprising recurring units of a formula selected from the group:

?Se - A - Se - Tem?n wherein A is a member selected from the group consisting of an alkylene radical having from about 9 to about 20 carbon atoms, and a divalent aromatic radical having from about 6 to about 50 carbon atoms;
m is at least 1; and n is at least 2.

- and -?B - Sea-x - Tem - Sex?b wherein B is a divalent hydrocarbylene radical;
a is a positive integer of at least 2;
x is a positive integer of at least 1 but less than a;
m is a positive integer in excess of 1; and b is a positive integer in excess of 1.