CA2202270A1 - Imaging apparatus and intermediate transfer blanket therefor - Google Patents

Abstract

Imaging apparatus including an imaging surface having a toner image formed thereon and an intermediate transfer member (30, 102, 104), which receives the toner image from the imaging surface and from which it is subsequently transferred. The intermediate transfer member (30, 102, 104) includes a drum (30) having mounting recesses formed therein and an intermediate transfer blanket (104) mounted on the drum (30). The blanket (104) has a layered transfer portion having a transfer surface (109) on one face thereof which receives the toner image and optionally an adhesive layer (126) on the opposite face thereof and a mounting fixture (106), attached to one edge of the layered transfer portion and adapted to mate with the mounting recesses in the drum, whereby the transfer blanket (104) is fixedly and removably mounted on the drum (30).

Description

WO96/11426 PCT~n95/00188 1 IMAGING APPARATUS AND INTERMEDIATE TRANSFER BLANKET ~ O~2 FI~LD OF THE INVENTION
3 The present invention relates to image forming and 4 image transfer apparatus especially for use in electrostatic 5 imaging using an intermediate transfer blanket.

7 The use of an intermediate transfer member in 8 electrostatic imaging is well known.
9 Various types of intermediate transfer members are 10 known and are described, for example in U.S. Patents 11 3,862,848, 4,684,238, 4,690,539 and 4,531,825 and in the 12 RELATED APPLICATIONS listed above, the specifications of all 13 of which are incorporated herein by reference.
14 Belt-type intermediate transfer members for use in 15 electrophotography are known in the art and are described, 16 inter alia, in U.S. Patents 3,893,761, 4,684,238 and 17 4,690,539, the specifications of which are incorporated 18 herein by reference.
19 The use of intermediate trans~er members and members 20 including transfer blank(ets for offset ink printing is also 21 well known. Such blankets have characteristics which are 22 suitable for ink transfer but are generally not usable, per 23 se, for liquid toner imaging.

The present invention seeks to provide, in one aspect 26 thereof, improved image transfer apparatus using an ; ,loved 27 intermediate transfer member.
28 The present invention further seeks to provide, in a 29 second aspect thereof, an improved image transfer member for 30 use in imaging apparatus, especially in image forming 31 apparatus using electrostatically charged toner.
32 The present invention further seeks to provide, in a 33 third aspect thereof, an improved image transfer blanket for 34 use as part of the image transfer member in imaging 35 apparatus, especially in image forming apparatus using 36 electrostatically charged toner.

W O96/11426 PCT~NL95/00188 1 There is thus provided in accordance with a preferred 2 embodiment of the invention, imaging apparatus comprising:

3 an imaging surface having an image, preferably a toner 4 image formed thereon; and an intermediate transfer member, which receives the 6 toner image from the imaging surface and from which it is 7 subsequently transferred, comprising:
8 a drum having mounting recesses formed therein;
9 and an intermediate transfer blanket mounted on the 11 drum, the blanket comprising:
12 a layered transfer portion having a transfer 13 surface on one face thereof which receives the toner image 14 and preferably an adhesive layer on an opposite surface 15 thereof; and 16 a mounting fixture, attached to only one 17 edge of the layered transfer portion and adapted to mate 18 with the mounting recesses in the drum, 19 whereby the transfer blanket is removably mounted on 20 the drum.
21 In a preferred embo~;~ent of the invention at least a 22 portion of a surface of the layered transfer portion 23 opposite to the transfer surface is bonded to the drum.
24 Preferably, the layered transfer portion comprises an 25 electrically conductive layer underlying the transfer 26 surface; and the mounting fixture comprises an electrically 27 conductive element, attached to one edge of the transfer 28 portion, which is electrically connected to the electrically 29 conductive layer.
In a preferred embodiment of the invention, the 31 electrically conductive element, which preferably comprises 32 at least one "L" shaped finger-like extension extending 33 therefrom, that contacts the drum, wherein the drum is 34 electrified to a voltage which is operative to transfer the 35 toner image from the imaging surface to the transfer 36 surface. Preferably, said at least one "L" shaped extension WO96/11426 PCT~n95/00188 PCNS ~ 3 ~

l has a first portion ext~n~; ng in a direction perpendicular 2 to the layered transfer portion and a second portion 3 attached and substantially perpendicular to the first 4 portion and extending substantially parallel to and away 5 from the layered transfer portion.

6 Prefera~ly, the mounting recesses further comprise 7 recesses therein which receive said second portion.

8 There is further provided in accordance with a 9 preferred embodiment of the invention, a substantially lO rectangular intermediate transfer blanket comprising:
ll a layered transfer portion having a transfer surface on 12 one face thereof; and 13 a mounting fixture, adapted for mounting the blanket on 14 a drum, attached to only one edge of the layered transfer 15 portion.
16 Preferably, the layered transfer portion comprises an 17 electrically conductive layer underlying the transfer 18 surface; and the mounting fixture comprises an electrically l9 conductive element, attached to one edge of the transfer 20 portion, which is electrically connected to the electrically 21 conductive layer.
22 Preferably, the electrically conductive element 23 comprises at least one "L" shaped finger-like extension 24 exten~;ng therefrom, which extension preferably has a first 25 portion extending in a direction perpendicular to the 26 layered transfer portion and a second portion attached and 27 substantially perpendicular to the first portion and 28 extending substantially parallel to and away from the 29 layered transfer portion.
In a preferred embodiment of the invention the layered 31 transfer portion comprises a conformal layer formed of a 32 material having a Shore A hardness of less than 65, 33 preferably less than about 50 and more than about 30.
34 Preferably, the transfer surface is a release layer for 35 toner.
36 There is further provided in accordance with a W O96/~1426 PCT~L95/00188 1 preferred embodiment of the invention, a substantially 2 rectangular intermediate transfer blanket comprising:
3 a layered transfer portion having a transfer surface on 4 one face and including a conductive layer underlying the 5 transfer surface; and 6 a conductive element, attached to one edge of the 7 transfer portion, which is electrically connected to the 8 conducting layer.
9 There is further provided in accordance with a 10 preferred embodiment of the invention, a layered 11 intermediate transfer member and blanket comprising:

12 a transfer surface on one face; and 13 a conforming layer having a shore A hardness of less 14 than about 65, preferably less than about 50 and preferably 15 more than about 30.

16 There is further provided in accordance with a 17 preferred embodiment of the invention, a layered 18 intermediate transfer blanket comprising:

19 a transfer surface on one face of the blanket; and an adhesive layer on the opposite face of the blanket 21 which is stable at a temperature of at least 80C, 22 preferably above 100C, more preferably above 120C, most 23 preferably above 150C.
24 There is further provided in a preferred embodiment of 25 the invention, a layered intermediate transfer blanket 26 comprising:
27 an transfer surface on one face of the blanket; and 28 a soft layer on the opposite face of the blanket which 29 has a Shore A hardness of less than 90, more preferably less 30 than 45, most preferably less than 25.
31 In a preferred embodiment of the invention the soft 32 layer comprises an acrylic polymer.
33 In a preferred embodiment of the invention the layered 34 transfer portion comprises an adhesive layer on a side 35 thereof opposite to the transfer surface.
36 There is further provided in accordance with a W O96/11426 PCTA~L95100i88 1 preferred embodiment of the invention, imaging apparatus for2 performing an imaging process, comprising:
3 an imaging surface having a liquid toner image 4 comprising toner particles and carrier liquid formed 5 thereon; and 6 an intermediate transfer member, which receives the 7 toner image from the imaging surface and from which it is 8 subsequently transferred, comprising:
9 a layered transfer portion having a transfer 10 surface on one face thereof which receives the toner image;
11 a resilient layer underlying the transfer surface 12 which comprises a material which is at least partly 13 leachable by the carrier liquid, and 14 a barrier layer, preferably comprising at least 15 partially hydrolyzed polyvinyl alcohol, that is 16 substantially impervious to the carrier liquid and is 17 situated intermediate the resilient layer and the transfer 18 surface.
l9 There is further provided, in a preferred embodiment of 20 the invention a layered intermediate transfer member 21 comprising:

22 a transfer surface;

23 a resilient layer underlying the transfer surface which 24 comprises a material which is at least partly leachable by a 25 liquid hydrocarbon; and 26 a barrier layer, preferably comprising at least 27 partially hydrolyzed polyvinyl alcohol, that is 28 substantially impervious to the liquid hydrocarbon and is 29 situated intermediate the resilient layer and the transfer 30 surface.

31 There is further provided, in accordance with a 32 preferred embodiment of the invention, a layered 33 intermediate transfer member for receiving liquid toner 34 images comprising toner particles and carrier liquid 35 comprising:

36 a transfer surface;

W O96111426 PCT~L95/00188 1 a resilient layer underlying the transfer surface which 2 comprises a material which is at least partly leachable in 3 the carrier liquid; and 4 a barrier layer, preferably comprising at least 5 partially hydrolyzed polyvinyl alcohol, that is 6 substantially impervious to the carrier liguid and is 7 situated intermediate the resilient layer and the transfer 8 surface.
9 There is further provided, in accordance with a 10 preferred embodiment of the invention, imaging apparatus for ll performing an imaging process, comprising:
12 an imaging surface having a liquid toner image 13 comprising toner particles and carrier liquid formed 14 thereon; and an intermediate transfer member, which receives the 16 toner image from the imaging surface and from which it is 17 subsequently transferred, comprising:
18 a layered transfer portion having a transfer 19 surface on one face thereof which receives the toner image;
a resilient layer underlying the transfer surface 21 which comprises a material which interferes with the 22 operation of the imaging process;
23 a barrier layer, preferably comprising at least 24 partially hydrolyzed polyvinyl alcohol, that is 25 substantially impervious to the interfering material 26 comprised in the resilient layer and is situated 27 intermediate the resilient layer and the transfer surface.
28 In a preferred embodiment of the invention, the 29 material is a gas and the barrier layer is a barrier layer 30 for gasses.
31 There is further provided, in accordance with a 32 preferred embodiment of the invention, a layered 33 intermediate transfer member, comprising:
34 a transfer surface;
a resilient layer underlying the transfer surface; and 36 a barrier layer, preferably comprising at least 1 partially hydrolyzed polyvinyl alcohol, that is2 substantially impervious to liquid hydrocarbons and is 3 situated intermediate the resilient layer and the transfer 4 surface.
There is further provided, in accordance with a 6 preferred embodiment of the invention, a layered 7 intermediate trans~er member, comprising:
8 a transfer surface;
9 a resilient layer underlying the transfer surface which 10 releases gases, and 11 a barrier layer, preferably comprising at least 12 partially hydrolyzed polyvinyl alcohol, that is 13 substantially impervious to the gasses and is situated 14 intermediate the resilient layer and the transfer surface.
There is further provided, in accordance with a 16 preferred embodiment of the invention, a layered 17 intermediate transfer member for receiving liquid toner 18 images comprising toner particles and carrier liquid 19 comprising:
a transfer surface;
21 a resilient layer underlying the transfer surface 22 comprising a material which is at least partly l~.h~hle in 23 the carrier liquid, and 24 a barrier layer, preferably comprising at least 25 partially hydrolyzed polyvinyl alcohol, that is 26 substantially impervious to the carrier liquid and is 27 situated intermediate the resilient layer and the transfer 28 surface.

36 .

.

2 The present invention will be understood and 3 appreciated more fully from the following detailed 4 description, taken in conjunction with the drawings in 5 which:
6 Fig. 1 is a simplified sectional illustration of 7 electrostatic imaging apparatus constructed and operative in 8 accordance with a preferred embodiment of the present 9 invention;
Fig. 2 is a simplified enlarged sectional illustration 11 of the apparatus of Fig. l;
12 Fig. 3A is a simplified, cross-sectional side view of 13 an intermediate transfer member, including a removable 14 intermediate transfer blanket mounted on a drum, in 15 accordance with a preferred embodiment of the invention;
16 Fig. 3B is a partially cut-away top view of the 17 intermediate transfer member of Fig. 3A, 18 Figs. 4A and 4B are respective top and side views o~ an 19 intermediate transfer blanket in accordance with a preferred 20 embodiment of the invention;
21 Fig. 4C shows details of the layered construction of 22 the intermediate transfer blanket in accordance with a 23 preferred embodiment of the invention;
24 Fig. 4D is a cut-away expanded view of a securing 25 mechanism on the intermediate transfer blanket of Figs 4A
26 and 4B; and 27 Fig. 5 is a simplified cross-sectional illustration of 28 a portion of an intermediate transfer member, including a 29 removable intermediate transfer blanket mounted on a drum in 30 accordance with another preferred embodiment of the 31 invention.

WO96/11426 PCT~n95/00188 PCNS - g -2 Reference is now made to Figs. 1 and 2 which illustrate 3 a multicolor elec~rostatic imaging system constructed and 4 operative in accordance with a preferred embodiment of the 5 present invention. As seen in Figs. 1 and 2 there is 6-provided an imaging sheet, preferably an organic 7 photoreceptor 12, typically mounted on a rotating drum 10.
8 Drum 10 is rotated about its axis by a motor or the like 9 (not shown), in the direction of arrow 18, past charging 10 apparatus 14, preferably a corotron, scorotron or roller 11 charger or other suitable charging apparatus known in the 12 art and which is adapted to charge the surface of sheet 13 photoreceptor 12. The image to be reproduced is focused by 14 an imager 16 upon the charged surface 12 at least partially 15 discharging the photoconductor in the areas struck by light, 16 thereby forming the electrostatic latent image. Thus, the 17 latent image normally includes image areas at a first 18 electrical potential and background areas at another 19 electrical potential.
Photoreceptor sheet 12 may use any suitable 21 arrangement of layers of materials as is known in the art, 22 however, in the preferred embodiment of the photoreceptor 23 sheet, certain of the layers are removed from the ends of 24 the sheet to facilitate its mounting on drum 10.
This preferred photoreceptor sheet and preferred 26 methods of mounting it on drum 10 are described in a co-27 pending U.S. Patent application of Belinkov et al., IMAGING
28 APPARATUS AND PHOTORECEPTOR THEREFOR, filed September 7, 29 1994, assigned serial number 08/301,775, and on applications 30 filed in other countries claiming priority therefrom, the 31 disclosure of which is incorporated herein by reference.
32 Alternatively, photoreceptor 12 may be deposited on the drum 33 10 and may form a continuous surface. Furthermore, 34 photoreceptor 12 may be a non-organic type photoconductor 35 based, for example, on a compound of Selenium.
36 Imaging apparatus lG may be a modulated laser beam W O96/11426 PCT~L95/00188 1 sCAnn; ng apparatus, an optical focusing device for imaging a 2 copy on a drum or other imaging apparatus such as is known 3 in the art.
4 Also associated with drum 10 and photoreceptor sheet 5 12, in the preferred embodiment of the invention, are a 6 multicolor liquid developer spray assembly 20, a developing 7 assembly 22, color specific cleaning blade assemblies 34, a 8 background cleaning station 24, an electrified squeegee 26, 9 a background discharge device 28, an intermediate transfer 10 member 30, cleaning apparatus 32, and, optionally, a ll neutralizing lamp assembly 36.
12 Developing assembly 22 preferably includes a 13 development roller 38. Development roller 38 is preferably 14 spaced from photoreceptor 12 thereby forming a gap 15 therebetween of typically 40 to 150 micrometers and is 16 charged to an electrical potential intermediate that of the 17 image and background areas of the image. Development roller 18 38 is thus operative, when maint~;ne~ at a suitable voltage, 19 to apply an electric field to aid development of the latent 20 electrostatic image.
21 Development roller 38 typically rotates in the same 22 sense as drum 10 as indicated by arrow 40. This rotation 23 provides for the surface of sheet 12 and development roller 24 38 to have opposite velocities at the gap between them.
Multicolor liquid developer spray assembly 20, whose 26 operation and structure is described in detail in U.S.
27 Patent 5,117,263, the disclosure of which is incorporated 28 herein by reference, may be mounted on axis 42 to allow 29 assembly 20 to be pivoted in such a manner that a spray of 30 liquid toner containing electrically charged pigmented toner 31 particles can be directed either onto a portion of the 32 development roller 38, a portion of the photoreceptor 12 33 or directly into a development region 44 between 34 photoreceptor 12 and development roller 38. Alternatively, 35 assembly 20 may be fixed. Preferably, the spray is directed 36 onto a portion of the development roller 38.

W O 96111426 PCT~NL95100188 1 Color specific cleaning blade assemblies 34 are 2 operatively associated with developer roller 38 for separate3 lell-oval o~ residual amounts of each colored toner r~m~ n~ ng 4 thereon after development. Each of blade assemblies 34 is 5 selectably brought into operative association with developer 6 roller 38 only when toner of a color corresponA~ng thereto 7 is supplied to development region 44 by spray assembly 20.
8 The construction and operation of cleaning blade assemblies 9 is described in PCT Publication W0 90/14619 and in US patent 10 5,289,238, the disclosures of which are incorporated herein 11 by reference.
12 Each cleaning blade assembly 34 includes a toner 13 directing member 52 which serves to direct the toner 14 removed by the cleaning blade assemblies 34 from the 15 developer roller 38 to se~arate collection containers 54, 16 56, 58, and 60, for each color to prevent cont~m~n~tion of 17 the various developers by mixing of the colors. The toner 18 collected by the collection containers is recycled to a 19 corresponding toner reservoir (55, 57, 59 and 61). A final 20 toner directing member 62 always engages the developer 21 roller 38 and the toner collected thereat is supplied into 22 collection cont~; ner 64 and thereafter to reservoir 65 via 23 separator 66 which is operative to separate relatively clean 24 carrier liquid from the various colored toner particles. The 25 separator 66 may be typically of the type described in U.S.
26 Patent 4,985,732, the disclosure of which is incorporated 27 herein by reference.
28 In a preferred embodiment of the invention, as 29 described in U.S. Patent 5,255,058, the disclosure of which 30 is incorporated herein by reference, where the imaging speed 31 is very high, a background cleaning station 24 typically 32 including a reverse roller 46 and a fluid spray apparatus 48 33 is provided. Reverse roller 46 which rotates in a direction 34 indicated by arrow 50 is electrically biased to a potential 35 intermediate that of the image and background areas of 36 photoconductive drum 10, but different from that of the CA 02202270 l997-04-09 W O96/11426 PCT~YL9S/00188 1 development roller. Reverse roller 46 is preferably spaced 2 apart from photoreceptor sheet 12 thereby forming a gap 3 therebetween which is typically 40 to 150 micrometers.
4 Fluid spray apparatus 48 receives liquid toner from 5 reservoir 65 via conduit 88 and operates to provide a supply 6 of preferably non-pigmented carrier liquid to the gap 7 between sheet 12 and reverse roller 46. The liquid supplied 8 by fluid spray apparatus 48 replaces the liquid removed from 9 drum 10 by development assembly 22 thus allowing the 10 reverse roller 46 to remove charged pigmented toner 11 particles by electrophoresis from the background areas of 12 the latent image. Excess fluid is removed from reverse 13 roller 46 by a liquid directing member 70 which continuously 14 engages reverse roller 46 to collect excess liquid 15 containing toner particles of various colors which is in 16 turn supplied to reservoir 65 via a collection container 64 17 and separator 66.
18 The apparatus embodied in reference numerals 46, 48, 50 19 and 70 is not required for low speed systems, but is 20 preferably included in high speed systems.
21 Preferably, an electrically biased squeegee roller 26 22 is urged against the surface of sheet 12 and is operative to 23 remove liquid carrier from the background regions and to 24 compact the image and remove liquid carrier therefrom in the 25 image regions. Squeegee roller 26 is preferably formed of 26 resilient slightly conductive polymeric material as is well 27 known in the art, and is preferably charged to a potential 28 of several hundred to a few thousand volts with the same 29 polarity as the polarity of the charge on the toner 30 particles.
31 In a first preferred ~ hoA;m~nt the squeegee roller is 32 made by molding a soft polyurethane rubber coating onto a 33 metal core, coating the molded core with a conductive 34 lacquer and coating the lacquer with a low conductivity 35 elastomer. Alternatively, in a second embodiment, the molded 36 coating can be made of an elastomer with a controlled WO96/114~6 PCT/NI~5/00188 1 conductivity and the lacquer can be omitted. In a third 2 embodiment, a sir~gle coating of controlled conductivity 3 elastomer is used and the outer layer is omitted.
4 In the first sgueeg~e embodiment the metal core is 5 cleaned, and coated with a rubber to metal adhesive, such 6 as, for example CILBOND 49 SF (Compounding Ingredients 7 Limited, UK) dissolved in an equal amount of methyl ethyl 8 ketone, which is dried at 110C for one hour. An outer mold 9 having a diameter about 9.5 mm greater than that of the core lO is dip coated with a release agent, such as, for example, a 11 mixture of 10 parts Syl-0f~f 7600 (Dow Corning), 1 part Syl-12 Off 7601 and 150 parts n-hexane which is then cured for one 13 hour at 110C. The space between the core and the mold (pre-14 heated to 70-80C) is filled with polyurethane rubber for 15 casting (CIL A 20, Compounding Ingredients Limited, UK) 16 which is preheated under vacuum at 80C for 16 hours and 17 then at 120C for an additional hour. The polyurethane is 18 cured at 135C for 8 hours. After cooling and le".o~,al of the 19 coated core from the mold (which removal may be aided by a 20 solvent, such as Isopar), the cast material is ground to 21 size to approximately +5 micrometers. The preferred hardness 22 of the coating is about 20 Shore A, although this hardness 23 may vary from 15-40 Shore A depending on the amount of 24 liquid removal desired.
The ground surface is cleaned with acetone and 26 preferably dip coated with a conductive lacquer (preferably, 27 3 parts H322 (Lord Corporation, USA) and 1 part ethyl 28 acetate) which has been prefiltered through a lint free 29 cloth to give a thickness (after drying) of about 30 30 micrometers.
31 A top layer of 50 parts Fomrez 50 (Witco. Corp., USA) 32 dissolved in 75 parts ethyl acetate to which is added 3 33 parts of DC193 (Dow Corning) and about 6 parts of di-phenyl 34 methane 4,4' di-isocyanate (MDI) (Desmodor 44V20 35 manufactured by Bayer, Germany) is filtered and dip coated 36 onto the lacquer coating a plurality of times to achieve a W O96/11~26 PCTANL95/00188 1 coating thickness of 60-70 micrometers. The coated squeegee 2 is dried at room temperature and cured at 140C for 2 hours.
3 The preferred hardness of the material forming the outer 4 layer is about 30-35 Shore A and this hardness can be 5 controlled by changing the proportion of MDI in the coating.
6 The coating has a resistivity in the range of 108 to 101 7 ohm-cm, with a preferred value of 1-3x108 to 2-3xlO9 ohm-cm.
8 In the second embodiment of the squeegee roller, the 9 cast covering for the core is preferably an elas~- - r having 10 the proper combination of hardness (15-30 Shore A, 11 preferably 20 Shore A) and resistivity (l-lOx106 ohm-cm).
12 ~his material can be polyurethane, nitrile or other oil 13 resistant rubber. Polyurethane with selectable resistivity 14 and hardness is available from Merthane Products (USA).
15 After casting as described above, the coating is ground to 16 size and finish and coated with a top layer which is made in 17 the same ~nne~ as the top layer of the first embodiment.
18 In the third embodiment of the squeegee roller, the top 19 layer is omitted and the conductive elastomer is preferably 20 cast to exact size.
21 Discharge device 28 is operative to flood the sheet 12 22 with light which discharges the voltage remaining on sheet 23 12, mainly to reduce electrical breakdown and improve 24 transfer of the image to intermediate transfer member 30.
25 Operation of such a device in a write black system is 26 descri~ed in U.S. Patent 5,280,326, the disclosure of which 27 is incorporated herein by reference.
28 Figs. 1 and 2 further show that multicolor toner spray 29 assembly 20 receives separate supplies of colored toner 30 typically from four different reservoirs 55, 57, 59 and 61.
31 Figure 1 shows four different colored toner reservoirs 55, 32 57, 59 and 61 typically containing the colors Yellow, 33 Magenta, Cyan and, optionally, Black respectively. Pumps 90, 34 92, 94 and 96 may be provided along respective supply 35 conduits 98, 101, 103 and 105 for providing a desired amount 36 of pressure to feed the colored toner to multicolor spray _ _ _ _ _ _ _ _ W O96/11426 PCTA~L95/00188 1 assembly 20. Alternatively, multicolor toner spray assembly2 20, which is preferably a three level spray assembly, 3 receives supplies of coloxed toner from up to six different 4 reservoirs (not shown) which allows for custom colored toner 5 in addition to the standard process colors.
6 A preferred type of toner for use with the present 7 invention is that described in Example 1 of U.S. Patent 8 4,794,651, the disclosure of which is incorporated herein by 9 reference or variants thereof as are well known in the art.
10 For colored liguid developers, carbon black is replaced by 11 color pigments as is well known in the art. Other toners may 12 alternatively be employed, including liquid toners and, as 13 indicated above, including powder toners.
14 Another preferred embodiment of the toner for use in 15 the invention is prepared using the following method:
16 1) Solubilizing 1400 grams of Nucrel 925 (ethylene 17 copolymer by Dupont) and 1400 g of Isopar L (Exxon) are 18 thoroughly mixed in an oil heated Ross Double Planetary 19 Mixer at least 24 RPM for 1.5 hours, with the oil 20 temperature at 130C. 1200 g of preheated Isopar L is added 21 and mixing is continued for an additional hour. The mixture 22 is cooled to 45C, while stirring is continued over a period 23 of several hours, to form a viscous material.
24 2) Milling and Grin~;ng 762 grams of the result of the 25 Solubilizing step are ground in a lS attritor (Union Process 26 Inc. Akron Ohio), charged with 3/16" carbon steel balls at 27 250 RPM, together with 66.7 grams of Mogul L carbon black 28 (Cabot), 6.7 grams of BT 583D (blue pigment produced by 29 Cookson), 5 grams of all~m;nl tri stearate and an additional 30 1459.6 grams of Isopar L for eight hours at 30C.
31 3) Continuation of Grinding 34.5 grams of ACumist A-12 32 (a micronised polyethylene wax produced by Allied Signal) is 33 added and gr; n~ i ng is continued for an additional 4 hours.
34 The resulting particles are fibrous particles have a 35 measured diameter in the range of 1-3 micrometers.
36 The resulting material is diluted with additional W O 96/11426 PCTA~L95/00188 1 Isopar L and Marcol 82 to give a working developer in which 2 the dry solids portion is about 1.7% and in which the 3 overall ratio of Isopar L to Marcol is between about 50:1 4 and 500:1, more preferably between about 100:1 and 200:1.
5 Charge director as described in US patent application 6 07/915,291 (utilizing lecithin, BBP and ICIG3300B) and in WO
7 94/02887, in an amount equal to 40 mg/gm of solids, is added 8 to charge the toner particles. Other charge directors and 9 additional additives as are known in the art may also be 10 used.
11 The above described process produces a black toner.
12 Cyan, magenta and yellow toners can be produced by using a 13 different mix of materials for step 2). For Cyan toner, 822g 14 of the solubilized material, 21.33 grams each of BT 583D and 15 BT 788D pigments (Cookson), 1.73 grams of D1355DD pigment 16 (BASF), 7.59 grams of aluminum tri stearate and 1426 grams 17 of Isopar L are used in step 2. For Magenta toner, 810 grams 18 of solubilized material, 48.3 grams of Finess Red F2B, 6.81 19 grams of aluminum tri-stearate and 1434.2 grams of Isopar L
20 are used in step 2. For yellow toner 810 grams of 21 solubilized material, 49.1 grams of D1355DD pigment, 6.9 22 grams of aluminum tri-stearate and 1423 grams of Isopar L
23 are used in step 2.
24 Intermediate transfer member 30, an especially 25 preferred embodiment of which is described in detail below 26 (in conjunction with Figs. 3 and 4), may, for some 27 embodiments of the invention, be any suitable intermediate 28 transfer member having a multilayered transfer portion such 29 as those described below or in US Patents 5,089,856 or 30 5,047,808 or in the applications of which this application 31 is a continuation in part, the disclosures of which are 32 incorporated herein by reference and by other structures 33 known in the art. Member 30 is maintained at a suitable 34 voltage and temperature for electrostatic transfer of the 35 image thereto from the image bearing surface. Intermediate 36 transfer member 30 is preferably associated with a pressure W O96/11426 PCTA~L95100188 1 roller 71 for transfer of the image onto a final substrate 2 72, such as paper, preferably by heat and pressure. For the 3 especially preferred toner described above, an image 4 temperature of about 95~ at the inception of fusing is 5 preferred.
6 Certain aspects of the present invention, especially 7 the method of mounting a lransfer blanket on a drum are of 8 general applicability and are applicable to a wide range of 9 blanket types for ink, liquid toner or powder toner as are lO known in the art.
11 Cleaning apparatus 32 is operative to scrub clean the 12 surface of photoreceptor 12 and preferably includes a 13 cleaning roller 74, a sprayer 76 to spray a non-polar 14 cleaning liquid to assist in the scrubbing process and a 15 wiper blade 78 to complete the cleaning of the 16 photoconductive surface. Cleaning roller 74 which may be 17 formed of any synthetic resin known in the art for this 18 purpose is driven in the same sense as drum 10 as indicated l9 by arrow 80, such that the surface of the roller scrubs the 20 surface of the photoreceptor. Any residual charge left on 21 the surface of photoreceptor sheet 12 may be removed by 22 flooding the photoconductive surface with light from 23 optional neutralizing lamp assembly 36, which may not be 24 required in practice.
In accordance with a preferred embodiment of the 26 invention, after developing each image in a given color, the 27 single color image is transferred to intermediate transfer 28 member 30. Subsequent iimages in different colors are 29 sequentially transferred in alignment with the previous 30 image onto intermediate transfer member 30. When all of the 31 desired images have been transferred thereto, the complete 32 multi-color image is transferred from transfer member 30 to 33 substrate 72. Impression roller 71 only produces operative 34 engagement between intermediate transfer member 30 and 35 substrate 72 when transfer of the composite image to 36 substrate 72 takes place. Alternatively, each single color W O96/11426 PCT~NL95/00188 1 image is separately transferred to the substrate via the 2 intermediate transfer member. In this case, the substrate is 3 fed through the ~chine once for each color or is held on a 4 platen and contacted with intermediate transfer member 30 5 for composite image transfer. Alternatively, the 6 intermediate transfer member is omitted and the developed 7 single color images are transferred sequentially directly 8 from drum 10 to substrate 72.
9 Figs. 3A, 3B and 4A-4D illustrate a preferred 10 embodiment of intermediate transfer member 30 in accordance 11 with a preferred embodiment of the invention. Fig 3A shows 12 an intermediate transfer blanket 100 mounted on a drum 102.
13 Transfer blanket 100 (whose details are shown in Figs. 4C
14 and 4D) comprises a preferably layered transfer portion 104 15 and a mounting fitting 106.
16 As shown most clearly in Fig. 4C, transfer portion 104 17 comprises a release layer 109 which is outermost on the 18 blanket when it is mounted on drum 102. Underlying layer 109 19 is a conforming layer 111 preferably of a soft elastomer, 20 preferably of polyurethane and preferably having a Shore A
21 hardness of less than about 65, more preferably, less than 22 about 55, but preferably more than about 35. A suitable 23 hardness value is between 45-55, preferably about 50.
24 Underlying layer 111 is a conductive layer 114 which 25 overlays a thin barrier layer 115. Barrier layer 115 26 overlays a blanket body 116 comprising a top layer 118, a 27 compressible layer 120 and a fabric layer 122. Underlying 28 the fabric layer is preferably an adhesive layer 126 which 29 is in contact with drum 102.
Drum 102 is preferably heated by an internal halogen 31 lamp heater or other heater to aid transfer of the image to 32 and from the release layer 109 to a final substrate as is 33 well known in the art. Other heating methods, or no heating 34 at all, may also be used in the practice of some aspects of 35 the invention. The degree of heating will depend on the 36 characteristics of the toner and or ink used in conjunction .

W O96111426 PCT~L95/00188 PCNS - 1.9 -1 with the invention.
2 As shown in Figs. 4A, 4B and 4D, mounting fitting 106 3 comprises an elongate electrically conducting bar 108, for 4 example of a metal such as al~ nllm formed with a series of S L-shaped mounting legs 110 tin the form of finger-like 6 extensions) which are also conducting, preferably of the 7 same material as bar 108, and preferably formed integrally 8 therewith. In particular, bar 108 is formed with a slot into 9 which the end of layered transfer portion 104 is inserted.
10 Preferably, the end of the layered portion which is inserted ll into the mounting bar does not have a release layer lO9 or 12 conforming layer 111, whereby conducting layer 114 is 13 exposed and is therefore in electrical contact with bar 108.
14 Alternatively, the bar 108 can be formed with sharp internal 15 projections which pierce the outer layers of the blanket and 16 contact the conducting layer.
17 Optionally, each of the layers beneath the conducting 18 layer 114 may be partially conducting (for example, by the 19 addition of conductive carbon black or metal fibers) and the 20 adhesive layer may be conductive, such that current also 21 flows directly from the drum surface to the conducting 22 layer.
23 In one preferred embodiment of the invention, fitting 24 106 is formed of a single sheet of metal, wherein the legs 25 are partially cut from the metal which is bent into a 26 shape to form the slot into which the layered portion is 27 inserted. After insertion, the outer walls of the slot are 28 forced against the layered portion to secure the layered 29 portion in the slot. The partially cut out portion is bent 30 to form the mounting legs.
31 In the preferred embo~;m~nt of the invention shown in 32 Figs. 1-3, drum 102 is maintained at a potential suitable 33 for transferring images to the intermediate transfer member, 34 for example at 500 volts, which voltage is applied, via 35 mounting fitting 106 to conductive layer 114. Thus, the 36 source of transfer voltage is very near the outer surface of CA 02202270 l997-04-09 W 096/11426 PCT~NL95/00188 1 portion 104 which allows for a lower transfer potential on 2 the drum.
3 In a preferred embodiment of the invention, Transfer 4 portion 104 is fabricated by the following procedure:
1- The starting structure for blanket construction is a 6 blanket body 116 generally similar to that generally used 7 for printing blankets. One suitable body is MCC-1129-02 8 manufactured and sold by Reeves SpA, Lodi Vecchio (Milano), 9 Italy. Other preferred blanket types are described in US
10 Patents 5,047,808; 4,984,025; 5,335,054 and PCT publications 11 W0 91/03007; W0 91/14393; W0 90/14619; and WO 90/04216, 12 which are incorporated herein by reference. In a preferred 13 embodiment of the invention, body 116 comprises a fabric 14 layer 122, preferably of woven NOMEX material and having a 15 thickness of about 200 micrometers, a compressible layer 16 120, preferably comprising about 400 micrometers of 17 saturated nitrile rubber loaded with carbon black to 18 increase its thermal conductivity. Layer 120 preferably 19 contains small voids (about 40 - 60 % by volume) and a top 20 layer 118 preferably comprised of the same material as the 21 compressible layer, but without voids. Layer 109 is 22 preferably about 100 micrometers thick. The blanket body is 23 produced by manufacturing methods as are generally used for 24 the production of offset printing blankets for ink offset 25 printing.
26 Blanket body 116 is preferably sized to a relatively 27 exact thickness by abrading portions of the surface of top 28 layer 118. A preferred thickness for the finished body 116 29 is about 700 micrometers, although other thicknesses are 30 useful, depending on the geometry of the printing system in 31 which it is used and the exact materials used in the blanket 32 body.
33 2- The fabric side of blanket body 116 is preferably 34 coated with a 30 micrometer thick coating of silicone based 35 adhesive (preferably, Type D 66 manufactured by Dow 36 Corning). The adhesive is covered with a sheet of mylar W O96/11426 PCTA~L9S/00188 1 coated with a fluorosilicone material, such as DP 5648 2 Release Paper (one side coat) distributed by H.P. Smith 3 Inc., Bedford Park, IL. This adhesive is characterized by 4 its good bond to the surface of drum 102 and is resistant to 5 ~he carrier liquid used in the liquid toner. The blanket may 6 be removed from the drum, when its replacement is desired, 7 by cutting the blanket along the edge of fitting 106 and 8 removing the blanket and fitting.
9 An adhesive is used to assure good thermal contact 10 between the back of the blanket and the drum on which it is 11 mounted. A silicone adhesive is used since adhesives 12 normally used in attachment of blankets deteriorate under 13 the heat which is generated in the underlying drum in the 14 preferred apparatus. While the temperature of the drum 15 varies, depending on the thermal resistance of the blanket 16 and the desired surface temperature of the blanket (which in 17 turn depends on the toner used in the process and the 18 details of transfer of the toner to the final substrate), 19 the drum temperature may reach 80C, 100C, 120C or 150C
20 or more.
21 3- Top layer 118 is preferably coated with a sub-micron 22 layer of primer before being coated with additional layers.
23 A preferred primer is Dow Corning 1205 Prime Coat. The type 24 of primer depends on the properties of the top layer and of 25 the conductive layer. Preferably, 0.3 micron of primer is 26 coated onto a clean top layer with a No. 0 bar in a wire-rod 27 coating apparatus and is allowed to dry before applying the 28 conductive layer.
29 4- Since blanket body 116 may contain materials such as 30 anti-oxidants, anti-ozonants or other additives which may 31 migrate through the upper layers of the blanket, for example 32 as a gas when the blanket is heated during the imaging 33 process and/or in the presence of carrier liquid such as 34 Isopar L, barrier layer 115 is preferably coated onto top 35 layer 118 (or more exactly onto the primer). This barrier 36 layer should be substantially impervious to such materials W O 96/11426 PCT~YL95/00188 1 in the blanket body which may migrate and/or to the carrier 2 liquid which is used.
3 If this layer is omitted, under certain circumst~n~-~4 the additive materials can cause deterioration of the 5 photoreceptor. In particular, it was found that the imaging 6 process may become humidity dependent.
7 In a preferred embodiment of the invention, a 4-11 8 micrometer layer of polyvinyl alcohol (88% hydrolyzed) is 9 coated onto the primer layer covering top layer 118.
Polyvinyl alcohol, 88% hydrolyzed, having an average 11 molecular weight preferably between 85,000 and 145,000 12 (Aldrich Chemical Co. Inc., Milwaukee, WI) is dissolved in 13 water at 90C by continuously stirring the mixture in a 14 reflux system for 30 minutes. After 30 minutes, a quantity 15 of ethanol equal to twice the quantity of water is added to 16 the solution, the resulting polyvinyl alcohol concentration 17 being preferably less than 10%. Higher concentration 18 solutions can be used; however, they give a more viscous 19 solution which is hard to spread evenly.
The solution is deposited on layer 118 of body 116 21 using a fine wire rod or knife inclined at 30-45 to the 22 direction of movement of the knife or body. The solvent is 23 evaporated either by drying at room temperature or by 24 blowing hot air on the layer.
One or more coating passes are employed to give the 26 required thickness.
27 Too thin a layer will result in some transfer of 28 material from body 116, which has been correlated with 29 reduced transfer efficiency from the photoreceptor to the 30 intermediate transfer blanket, which is believed to be 31 caused by photoreceptor deterioration. While four 32 micrometers of material appears to be sufficient to avoid 33 l~,hing, a somewhat larger thickness is preferably used.
34 Other barrier materials and other thicknesses may be 35 used depending on the carrier liquid used for the toner or 36 the gasses omitted by body 116. Other barrier materials may _ _ _ _ _ _ _ _ _ _ W O96/11426 PCT~L95/00188 1 require lesser or greater thickness depending on their 2 resistance to the carrier liquid or the yasses released by 3 body 116. Alternatively, i body 116 resists l~hi~g by the 4 carrier liquid or does not contain materials which are 5 released (especially when body 116 is heated) or any anti-6 oxidants and/or anti-ozonants, layer 115 may be omitted.
7 Polyvinyl alcohol is a thermoplastic crystalline 8 material having a melting point which is higher than the 9 temperature of the blanket during operation. Polyvinyl 10 alcohol is also believed to form a layer which is impervious 11 to gasses and to the hydrocarbon carrier liquid used in the 12 liquid toner.
13 5- Conductive layer 114 i5 preferably formed of acrylic 14 rubber loaded with conducl,ive carbon black. In a preferred 15 embodiment of the invention, only 2-3 micrometers of 16 conductive coating are reguired. The conductive layer is 17 formed by first compoundin~ 300 grams of Hytemp 4051EP (Zeon 18 Chemicals) with 6 grams of Hytemp NPC 50 and 9 grams of 19 sodium stearate in a two-roll mill for 20 minutes; and then 20 dissolving 150 grams of the compounded material in 2000 21 grams of methyl ethyl ketone (MEK) by stirring for 12 hours 22 at room temperature.
23 40 grams of conductive carbon black, such as, for 24 example, Printex XE2 (Degussa) are added to the solution and 25 the mixture is ground in a 01 attritor (Union Process) 26 loaded with 3/16" steel balls. Gr;n~1ng proceeds at 10C for 27 4 hours after which time the material is diluted by the 28 addition of MEK to a concentration of 7.5-8% solids and 29 discharged from the grinder in the form of a conductive 30 lacquer.
31 The blanket (after step 3 or step 4) is overcoated with 32 about 3 micrometers of the conductive lac~uer (three passes 33 using a No. 0 rod) and allowed to dry for 5 minutes at room 34 temperature.
An additional coating of primer is added over the 36 conductive lacquer (except: for the portion which is to be 1 inserted into bar 108) before the soft elastomeric 2 conforming layer is applied.
3 The resistance of the conductive layer should 4 preferably be more than about 20 kohmsJs~uare and preferably 5 less than about 50 kohm/square. This value will depend on 6 the resistivity of the layers above the conducting layer and 7 on the aspect ratio of the blanket. In general, the 8 resistance should be low enough so that the current flowing 9 on the conducting layer (to supply leakage current through 10 the overlying layers) should not cause a substantial 11 variation of voltage along the surface of the blanket. The 12 resistance of the conducting layer and, more importantl~, 13 the resistance of the overlying layers control the current 14 flowing through the overlying layers. Generally speaking, 15 the conductive layer has a relatively low resistance and 16 resistivity, the conforming layer (layer 111) has a higher 17 resistivity and the overl~ing release layer (layer 109) has 18 a still higher resistivity.
19 6- One kg of pre-filtered Fomrez-50 polyester resin 20 (Hagalil Company, Ashdod, Israel) is dehydrated and degassed 21 under vacuum at 60C. 600 grams of the degassed material is 22 mixed with 1.4 grams of di-butyl-tin-diluarate (Aldrich) and 23 degassed at room temperature for 2 hours. 30 grams of the 24 resulting material, 3.15 grams of RTV Silicone 118 (General 25 Electric) and 4.5 grams of Polyurethane cross-linker, 26 DESMODUR 44V20 (Bayer) are stirred together. A 100 27 micrometer layer of the material is coated over the primed 28 conductive layer using a No. 3 wire rod with several passes 29 under clean conditions, preferably, class 100 conditions.
30 The coating is cured for two hours at room temperature under 31 a clean hood to form a polyurethane layer.
32 Other methods of forming suitable conforming layers are 33 shown and described in the parents of this application.
34 Alternatively, the conductive layer may be omitted and layer 35 118 made conductive.
36 Layer 111 which is thus formed should have a resistance _ _ _ _ _ _ W O 96/11426 PCT~L95/00188 PCNS - 2~ -1 of the order of about 109 ohm-cm, good thermal stability at 2 the working temperature of the blanket surface, which is 3 preferably about 100C or less.
4 The function of the conforming layer is to provide good 5 conformation of the blanket to the image forming surface 6 (and the image on the image forming surace) at the low 7 pressures used in transfer of the image from the image 8 forming surface to the blanket. The layer should have a 9 Shore A hardness preferabl~ of between 25 or 30 and 65, more 10 preferably about 50. While a thickness of 100 micrometers is 11 preferred, other thicknesses, between 50 micrometers and 300 12 micrometers can be used, with 75 to 125 micrometers being 13 preferred.
14 7- 12 grams of RTV silicone 236 (Dow Corning) release 15 material preferably diluted with 2 grams of Isopar L (Exxon) 16 and 0.72 grams of Syl-off 297 (Dow Corning) are mixed 17 together. A wire rod (ba~ No. 1) coating system is used, 18 with five or six passes, under clean conditions to achieve 19 an 8 micrometer release layer thickness. The material is 20 cured at 140C for two hours. The cured release material h~s 21 a resistivity of approximately 1014 to I015 ohm-cm.
22 In order to mount bl~nket 100 on drum 102, mounting 23 legs 110 are inserted into a plurality of mounting holes 130 24 formed in drum 102, preferably without removing the mylar 25 sheet from the adhesive layer (the back of the blanket). As 26 can be seen most clearly in Fig. 3A, 3B and 4D, mounting 27 legs 110 each have a tip portion 132 and a back portion 134.
28 Tips 132 are inserted into slots formed in the far sidewalls 29 of mounting holes 130 and the back portion 134 rests against 30 the opposite sidewall of the hole. In this way the end of 31 the blanket is accurately positioned. The edge of the mylar 32 sheet closest to the legs is removed and the remainder of 33 the mylar sheet is progressively removed while making sure 34 that the successive portions of the blanket which are thus 35 attached to the drum by the adhesive lie flat against the 36 drum.

_ _ W O96/11426 PCTn~L95/00188 1 The present inventors have found that this method of 2 mounting is far superior to either adhesive mounting alone 3 or to grippers at both ends of the blanket in providing a 4 stable transfer surface.
As an alternative to, or additional to, the adhesive 6 layer 126, a very soft conforming layer may be used at the 7 back of the blanket. A soft layer of this type will allow 8 for good thermal contact between the blanket and the heated 9 drum 102 so that the temperature of the drum need not be 10 excessive in order for the outer surface of the blanket to 11 reach its operating temperature. Furthermore, such a very 12 soft layer will cause the blanket to "cling" to the drum 13 obviating the use of adhesive under certain circumstances.
14 Furthermore, when the blanket is replaced there is no 15 adhesive residue on the drum to be removed.
16 A very soft layer may be produced by the following 17 method:
18 1- lOOg of Hi-Temp 4051 EP (Zeon) acrylic resin is 19 mixed with 2g NPC-50 crosslinker (Zeon) and 3g sodium 20 stearate and dissolved in toluene to give a solution of 15%
21 non-volatile solids. Optionally, up to about 40g of carbon 22 black Pearls 130 (Cabot) is added.
23 2- A thin layer of the solution is coated onto release 24 coated mylar and dried. This process is repeated several 25 times until a thickness of preferably 20-30 micrometers is 26 achieved.
27 3- The uncured resin is laminated to the adhesive 28 layer of a blanket produced in accordance with the 29 invention, or directly to the fabric layer. This step is 30 preferably carried out prior to the cure of the release 31 layer.
32 4- The lAminAted structure is cured together with the 33 release layer and the release coated mylar is removed.
34 The layer has a Shore A hardness of about 20-24 35 without carbon black and about 40-45 with carbon black.
36 Softer materials are also suitable; however, substantially W O96/11426 PCTA~L9S/00188 1 harder materials do not adhere well to the drum surface.
2 Optionally, the adhesive :Layer at the trailing end of the 3 blanket is not coated with the very soft layer to improve 4 coherence of the blanket and the drum. This is especially 5 desirable for harder layers.
6 The acrylic material may be replaced by other soft 7 elastomer materials such as soft polyurethane or nitrile 8 rubber. Other heat improving filler~ which have a smaller 9 effect on the hardness of the final product may be used 10 instead of carbon black, such as Fe203 or alpha aluminum 11 oxide.
12 Fig. 5 shows an alternative, preferred embodiment of 13 the invention in which somewhat different shaped holes 130' 14 are used. In this embodiment the back portion 134 rests 15 against a protrusion 150 formed on one side of the hole 16 while a surface 154 of leg 110 rests against the bottom 156 17 of a protrusion formed on the other side of the hole.
18 While the preferred electrical connection between the 19 conductive layer and the mounting bar is preferably achieved 20 by removing (or not forming) the layers which overlay an end 21 portion of the conductive layer, piercing the overlying 22 layers, for example, by crimping and/or piercing the 23 mounting bar, for example, at points marked 160 in Fig. 4D.
24 Crimping can also be used to hold the blanket in the 25 mounting bar.
26 While the adhesive layer preferably covers the back of 27 the blanket, alternatively the adhesive layer may cover only 28 a portion of the back such as the edge farthest away from 29 the bracket (the trailing edge of the blanket); or may, for 30 some embodiments of the invention and under certain 31 circumstances, be omitted.
32 It should be underst;ood that some aspects of the 33 invention are not limited to the specific type of image 34 forming system used and some aspects of the present 35 invention are also useful with any suitable imaging system 36 which forms a liquid toner :Lmage on an image forming surface W O 96111426 PCT~L95/00188 1 and, for some aspects of the invention, with powder toner 2 systems. Some aspects of the invention are also useful in 3 systems such as those using other types of intermediate 4 transfer members such as belt or continuous coated drum type 5 transfer members. Some aspects of the invention are suitable 6 for use with offset printing systems. The specific details 7 given above for the image forming system are included as 8 part of a best mode of carrying out the invention; however, 9 many aspects of the invention are applicable to a wide range 10 of systems as known in the art for electrophotographic and 11 offset printing and copying.
12 It will be appreciated by persons skilled in the art 13 that the present invention is not limited by the description 14 and example provided hereinabove. Rather, the scope of this 15 invention is defined only by the claims which follow:

~4

Claims (47)

1. Imaging apparatus comprising:
an imaging surface having a toner image formed thereon;
and an intermediate transfer member, which receives the toner image from the imaging surface and from which it is subsequently transferred, comprising:
a drum having mounting recesses formed therein; and an intermediate transfer blanket mounted on the drum, the blanket comprising:
a layered transfer portion having a transfer surface on one face thereof which receives the toner image; and a mounting fixture, attached to only one edge of the layered transfer portion and adapted to mate with the mounting recesses in the drum, whereby the transfer blanket is removably mounted on the drum.

2. Apparatus according to claim 1 wherein at least a portion of a surface of the layered transfer portion opposite to the transfer surface is bonded to the drum.

3. Apparatus according to claim 1 or claim 2 wherein the layered transfer potion comprises an adhesive layer on a second face thereof opposite the transfer surface.

4. Apparatus according to any of the preceding claims wherein the layered transfer portion comprises an electrically conductive layer underlying the transfer surface; and wherein the mounting fixture comprises an electrically conductive element, attached to one edge of the transfer portion, which is electrically connected to the electrically conductive layer other than via the conduction of the transfer surface.

5. Apparatus according to claim 4 wherein the electrically conductive element contacts the drum and wherein the drum is electrified to a voltage which is operative to transfer the toner image from the imaging surface to the transfer surface.

6. Apparatus according to claim 4 wherein the electrically conductive element comprises at least one "L" shaped finger-like extension extending therefrom.

7. Apparatus according to claim 6 wherein said at least one "L" shaped extension has a first portion extending in a direction perpendicular to the layered transfer portion and a second portion attached and substantially perpendicular to the first portion and extending substantially parallel to and away from the layered transfer portion.

8. Apparatus according to claim 7 wherein said mounting recesses further comprise recesses therein which receive said second portion.

9. A substantially rectangular intermediate transfer blanket comprising:
a layered transfer portion having a transfer surface on one face thereof; and a mounting fixture, adapted for mounting the blanket on a drum, attached to only one edge of the layered transfer portion.

10. An intermediate transfer blanket according to claim 9 wherein the layered transfer portion comprises an electrically conductive layer underlying the transfer surface; and wherein the mounting fixture comprises an electrically conductive element, attached to one edge of the transfer portion, which is electrically connected to the electrically conductive layer.

11. A substantially rectangular intermediate transfer blanket comprising:
a layered transfer portion having a transfer surface on one face thereof and including an electrically conductive layer underlying the transfer surface; and an electrically conductive element, attached to one edge of the transfer portion, which is electrically connected to the conducting layer other than via conduction of the transfer surface.

12. An intermediate transfer blanket according to claim 10 or claim 11 wherein the electrically conductive element comprises at least one "L" shaped finger-like extension extending therefrom.

13. An intermediate transfer blanket according to claim 12 wherein said at least one "L" shaped extension has a first portion extending in a direction perpendicular to the layered transfer portion and a second portion attached and substantially perpendicular to the first portion and extending substantially parallel to and away from the layered transfer portion.

14. An intermediate transfer member according to any of claims 9-13 and including;
a resilient layer underlying the transfer surface; and a barrier layer that is substantially impervious to liquid hydrocarbon and is situated intermediate the resilient layer and the transfer surface.

15. A layered intermediate transfer member comprising:
a transfer surface;
a resilient layer underlying the transfer surface; and a barrier layer that is substantially impervious to liquid hydrocarbon and is situated intermediate the resilient layer and the transfer surface.

16. An intermediate transfer member according to claim 14 or claim 15 wherein the resilient layer comprises a material which is at least partly leachable by the liquid hydrocarbon.

17. An intermediate transfer member according to any of claims 14-16 wherein the member is adapted for the transfer of liquid toner images comprising toner particles and carrier liquid and wherein the liquid hydrocarbon is the carrier liquid.

18. An intermediate transfer member according to any of claims 9-13 and including:
a resilient layer underlying the transfer surface; and a barrier layer that is substantially impervious to gases and is situated intermediate the resilient layer and the transfer surface.

19. A layered intermediate transfer member comprising:
a transfer surface;
a resilient layer underlying the transfer surface which releases gases; and a barrier layer that is substantially impervious to gases and is situated intermediate the resilient layer and the transfer surface.

20. An intermediate transfer member according to any of claims 14-19 wherein the barrier layer comprises at least partially hydrolyzed polyvinyl alcohol.

21. An intermediate transfer blanket according to any of claims 9-20 wherein the layered transfer portion comprises a conformal layer formed of a material having a Shore A

hardness of less than 65.

22. An layered intermediate transfer member comprising:
an outermost transfer surface;
a conforming layer operatively associated with the transfer surface and having a shore A hardness of less than about 65; and a resilient layer, having a resilient deformation to a compressive force, underlying the conforming layer.

23. A substantially rectangular intermediate transfer blanket in accordance with claim 22.

24. An intermediate transfer blanket according to any of claims 21-23 wherein the material has a Shore A hardness of less than about 50.

25. An intermediate transfer member according to any of claims 21-24 wherein the material has a Shore A hardness of more than about 30.

26. An intermediate transfer member according to claim 18 21,24 wherein the material has a Shore A hardness of more than about 35.

27. An intermediate transfer blanket according to any of claims 9-26 wherein the layered transfer portion comprises a soft layer, having a Shore A hardness of less than 90, on the surface of the layered transfer portion opposite to the transfer surface.

28. An layered intermediate transfer member comprising:
a transfer surface on one face of the blanket; and a soft layer, having a Shore A hardness of less than 90, on the surface of the layered transfer portion opposite to the transfer surface.

29. An intermediate transfer member according to claim 27 or claim 28 wherein the soft layer has a Shore A hardness of less than about 45.

30. An intermediate transfer member according to claim 27 or claim 28 wherein the soft layer has a Shore A hardness of less than about 25.

31. An intermediate transfer member according to claim 27 or claim 28 wherein the soft layer has a Shore A hardness of about 45.

32. An intermediate transfer blanket according to any of claims 27-31 wherein the soft layer comprises an acrylic elastomer.

33. An intermediate transfer blanket according to any of claims 9-32 wherein the layered transfer portion comprises an adhesive layer on a face thereof opposite to the transfer surface.

34. An intermediate transfer blanket according to claim 33 wherein the adhesive layer is stable at a temperature of at least 80°C.

35. A layered intermediate transfer blanket comprising:
an transfer surface on one face of the blanket; and an adhesive layer on a face thereof opposite the transfer surface which layer is stable at a temperature of at least 80°C.

36. An intermediate transfer blanket according to any of claims 33-35 wherein the adhesive layer is stable at a temperature above 100°C.

37. An intermediate transfer blanket according to claim 36 wherein the adhesive layer is stable at a temperature above 120°C.

38. An intermediate transfer blanket according to claim 36 wherein the adhesive layer is stable at a temperature above 150°C.

39. An intermediate transfer member comprising:
a conductive layer having a relatively low electrical resistivity;
an outer layer having a relatively high electrical resistivity; and a third layer intermediate the conductive and outer layers having an electrical resistivity intermediate the relatively low and relatively high electrical resistivities.

40. An intermediate transfer member according to claim 39 wherein the third layer is a conforming layer having a Shore A hardness of less than about 65.

41. An intermediate transfer member according to claim 39 or claim 40 wherein the outer layer is a transfer layer.

42. An intermediate transfer member according to any of claims 9-38 or 41 wherein the outer layer is a release layer for toner.

43. Imaging apparatus for performing an imaging process, comprising:
an imaging surface having a liquid toner image comprising toner particles and carrier liquid formed thereon; and an intermediate transfer member according to any of claims 9-31, which receives the toner image from the imaging surface and from which it is subsequently transferred.

44. Imaging apparatus for performing an imaging process, comprising:
an imaging surface having a liquid toner image comprising toner particles and carrier liquid formed thereon; and an intermediate transfer member, which receives the toner image from the imaging surface and from which it is subsequently transferred, comprising:
a layered transfer portion having a transfer surface on one face thereof which receives the toner image;
a resilient layer underlying the transfer surface which interferes with the operation of the imaging process;
and a barrier layer that is substantially impervious to the interfering material comprised in the resilient layer and is situated intermediate the resilient layer and the transfer surface.

45. Imaging apparatus according to claim 44 wherein the barrier layer comprises at least partially hydrolyzed polyvinyl alcohol.

46. Imaging apparatus according to claim 44 or claim 4 wherein the barrier layer is a barrier layer for gases.

47. Imaging apparatus according to any of claims 44-46 wherein the barrier layer is a barrier layer for the carrier liquid.