Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – From phenol – phenol ether – or inorganic phenolate
Reexamination Certificate
2001-12-04
2003-12-16
Boykin, Terressa M. (Department: 1711)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
From phenol, phenol ether, or inorganic phenolate
C430S058700, C430S056000, C430S066000, C430S096000, C528S198000
Reexamination Certificate
active
06664361
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a novel diphenol compound and to a novel aromatic polycarbonate resin containing diol units from the diphenol compound. The present invention is also directed to an electrophotographic photoconductor having an electroconductive support and a photoconductive layer formed thereon and containing the above aromatic polycarbonate resin which has charge transporting properties.
2. Description of Prior Art
Recently organic photoconductors (OPC) are used in many copying machines and printers. The organic photoconductor has a layered structure comprising a charge generation layer (CGL) and a charge transport layer (CTL) which are successively overlaid on an electroconductive support. The charge transport layer (CTL) is a film-shaped layer comprising a binder resin and a low-molecular-weight charge transport material (CTM) dissolved therein. The addition of such a low-molecular-weight charge transport material (CTM) to the binder resin lowers the intrinsic mechanical strength of the binder resin, so that the CTL film is fragile and has a low tensile strength. Such lowering of the mechanical strength of the CTL causes the wearing of the photoconductor or forms scratches and cracks on the surface of the photoconductor.
Although some vinyl polymers such as polyvinyl anthracene, polyvinyl pyrene and poly-N-vinylcarbazole have been studied as high-molecular-weight photoconductive materials for forming a charge transporting complex for use in the conventional organic photoconductor, such polymers are not satisfactory from the viewpoint of photosensitivity.
In addition, high-molecular-weight materials having charge transporting properties have been also studied to eliminate the shortcomings of the above-mentioned layered photoconductor. For instance, there are proposed an acrylic resin having a triphenylamine structure as reported by M. Stolka et al., in “J. Polym. Sci., vol 21, 969 (1983)”; a vinyl polymer having a hydrazone structure as described in “Japan Hard Copy '89 p. 67”; an aromatic polycarbonate resin having a benzidine structure as disclosed in Japanese Laid-Open Patent Application 64-9964; and polycarbonate resins having a triarylamine structure as disclosed in U.S. Pat. Nos. 4,801,517, 4,806,443, 4,806,444, 4,937,165, 4,959,288, 5,030,532, 5,034,296, and 5,080,989, and Japanese Laid-Open Patent Applications Nos. 64-9964, 3-221522, 2-304456, 4-11627, 4-175337, 4-18371, 4-31404, and 4-133065. However, any materials have not yet been put to practical use.
According to the report of “Physical Review B46 6705 (1992)” by M. A. Abkowitz et al., it is confirmed that the drift mobility of a high-molecular weight charge transport material is lower than that of a low-molecular weight material by one figure. This report is based on the comparison between the photoconductor containing a low-molecular weight tetraarylbenzidine derivative dispersed in the photoconductive layer and the one containing a high-molecular polycarbonate having a tetraarylbenzidine-containing skeleton in its molecule and suggests that the photoconductor employing the high-molecular weight charge transport material produces poor results in terms of the photosensitivity and the residual potential although the mechanical strength of the photoconductor is improved.
SUMMARY OF THE INVENTION
The reason for poor results in the photosensitivity and the residual potential caused by use of the high-molecular weight charge transport material has not yet been clarified. It is, however, inferred that, in a polycarbonate having a tetraarylbenzidine-containing skeleton, the presence of electron-attracting carbonyloxy groups and electron-donating tertiary amino groups on the aryl groups causes localization of electrons, which adversely affects the hole transfer.
In accordance with one aspect of the present invention there is provided a diphenol compound comprising: at least one triarylamine group, two divalent alkane groups each having two, first and second bonds, said first bond of each of said alkane groups being bonded to respective one of the aryl groups of said at least one triarylamine group, an aryl group bonded to the second bond of each of said two alkane groups, and a hydroxyl group bonded to the aryl group linked to each of said two alkane groups.
In another aspect, the present invention provides a diphenol compound represented by the following formula (1):
wherein Ar
1
, Ar
2
, Ar
4
and Ar
5
stand, independently from each other, for an arylene group or a substituted arylene group, Ar
3
stands for an aryl group or a substituted aryl group, Z stands for an arylene group or —Ar
6
—Za—Ar
6
— where Ar
6
represents an arylene group or a substituted arylene group and Za represents —O—, —S— or an alkylene group, R and R′ stand, independently from each other, for a straight chain alkylene group or a branched alkylene group and n is an integer of 0 or 1.
The present invention also provides an aromatic polycarbonate resin comprising a main structural unit represented by the following formula (3):
wherein Ar
1
, Ar
2
, Ar
4
and Ar
5
stand, independently from each other, for an arylene group or a substituted arylene group, Ar
3
stands for an aryl group or a substituted aryl group, Z stands for an arylene group or —Ar
6
—Za—Ar
6
— where Ar
6
represents an arylene group or a substituted arylene group and Za represents —O—, —S— or an alkylene group, R and R′ stand, independently from each other, for a straight chain alkylene group or a branched alkylene group and n is an integer of 0 or 1.
The present invention further provides a polycarbonate resin comprising a recurring unit represented by the following formula (6):
wherein Ra, Rb, Rc and Rd stand for an alkyl group, Ar
3
stands for an aryl group or a substituted aryl group, Z stands for an arylene group or —Ar
6
—Za—Ar
6
— where Ar
6
represents an arylene group or a substituted arylene group and Za represents —O—, —S— or an alkylene group, R and R′ stand, independently from each other, for a straight chain alkylene group or a branched alkylene group, n is an integer of 0 or 1 and X stands for a group selected from the group consisting of divalent aliphatic groups, substituted divalent aliphatic groups, divalent alicyclic groups, substituted divalent alicyclic groups, divalent aromatic groups, substituted divalent aromatic groups, divalent groups obtained by linking at least two of the foregoing groups and groups represented by the following formulas:
wherein R
1
, R
2
, R
3
and R
4
stand, independently from each other, for an alkyl group, a substituted alkyl group, an aryl group, a substituted aryl group or a halogen atom, a and b are independently an integer of 0-4, c and d are independently an integer of 0-3, Y is selected from the group consisting of a direct bond, straight chain alkylene groups having 2-12 carbon atoms, substituted straight chain alkylene groups having 2-12 carbon atoms, branched A chain alkylene groups having 3-12 carbon atoms, substituted branched chain alkylene groups having 3-12 carbon atoms, divalent groups composed of at least one alkylene group having 1-10 carbon atoms and at least one —O— or at least one —S—, —O—, —S—, —SO—, —SO
2
—, —CO—, —COO— and groups represented by the following formulas:
wherein Z
1
and Z
2
stand independently from each other for a divalent aliphatic group, a substituted divalent aliphatic group, an arylene group or a substituted arylene group; R
5
1
R
6
and R
12
stand independently from each other for a halogen atom, an alkyl group, a substituted alkyl group, an alkoxyl group, a substituted alkoxyl group, an aryl group or a substituted aryl group, R
7
, R
8
, R
9
, R
10
and R
11
stand independently from each other for a hydrogen atom, R
6
and R
7
may form a carbocyclic ring having 5 to 12 carbon atoms together, R
13
and R
14
stand independently from each other for a direct bond or an alkylene group having 1-4 carbon atoms, R
15
and R
16
stand independently from each other an alkyl group, a substituted
Kawamura Shin'ichi
Morooka Katsuhiro
Nagai Kazukiyo
Ri Kohkoku
Sasaki Masaomi
Boykin Terressa M.
Oblon & Spivak, McClelland, Maier & Neustadt P.C.
Ricoh & Company, Ltd.
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