Intermediate transfer member, imaging apparatus, and method
View Patent ↗An intermediate transfer member for electrophotography includes a substrate, a cured static dissipative silicone compliant layer comprising crosslinked silicone polymer formed from a UV light curable siloxane and a UV curing catalyst, and an outermost surface ceramer layer. This intermediate transfer member can be incorporated into a suitable imaging apparatus for forming a toned image on a receiver element.
1. An intermediate transfer member comprising:
a static dissipative polymeric substrate, a cured static dissipative silicone compliant layer, and an outermost surface ceramer layer formed over the cured static dissipative silicone compliant layer,
(1) wherein the cured static dissipative silicone compliant layer comprises a crosslinked silicone polymer formed from a UV light curable siloxane comprising ether forming epoxy functionalized polycyclohexane crosslinked silicone and (p-isopropylphenyl)(p-methylphenyl)iodonium tetrakis(pentafluorophenyl)borate UV photoacid catalyst,
(2) wherein the cured static dissipative silicone compliant layer includes inorganic particles of acicular electroconductive oxides present in an amount of at least 15 weight % to 30 weight % of the crosslinked silicone polymer, which electroconductive oxides consist of:
inorganic particles of acicular titanium dioxide coated with tin oxide doped with antimony and having a particle size of 5.15 μm length and 0.27 μm diameter, with a powder resistivity of 10-60 ohm-cm, and
inorganic particles of acicular electroconductive tin oxide doped with antimony and having a particle size of 0.2 to 2 μm length and 0.1 to 0.2 μm diameter, with a powder resistivity of 100 ohm-cm, and
the weight ratio of the acicular titanium dioxide particles coated with tin oxide doped with antimony to the acicular electroconductive tin oxide particles doped with antimony is 2.2, and
(3) wherein the cured static dissipative silicone compliant layer has a DC volume resistivity in the range of 10 10 to 10 11 ohm-cm, where its resistivity at 15% relative humidity divided by its resistivity at 100% relative humidity has a ratio not exceeding the value of 2, and wherein the epoxy functionalized polycyclohexane crosslinked silicone comprises a mixture of:
A) epoxycyclohexylethylmethylsiloxane-dimethylsiloxane copolymer with 3 to 4 mole % of epoxycyclohexylethylmethylsiloxane, a viscosity of 650 centipoise to 850 centipoise, and a molecular weight of 18,000 to 20,000, and
B) epoxycyclohexylethylmethylsiloxane-dimethylsiloxane copolymer having 8 to 12 mole % of epoxycyclohexylethylmethylsiloxane, a viscosity of 300 centipoise to 450 centipoise, and a molecular weight of from 10,000 to 12,000,
in a weight ratio of 0.36.
2. The intermediate transfer member of claim 1 , wherein the ceramer layer comprises a fluoroceramer.
3. The intermediate transfer member of claim 2 , wherein the ceramer layer consists essentially of a non-particulate, non-elastomeric fluoroceramer and nanosized inorganic particles that are distributed within the non-particulate fluoroceramer in an amount of at least 5 and up to and including 50 weight % of the outermost surface layer.
4. The intermediate transfer member of claim 1 that is an endless belt.
5. The intermediate transfer member of claim 1 wherein the cured static dissipative silicone compliant layer has a thickness of at least 50 μm and up to and including 500 μm.
6. The intermediate transfer member of claim 1 wherein the cured static dissipative silicone compliant layer has a thickness of at least 80 μm and up to and including 400 μm.
7. The intermediate transfer member of claim 1 wherein the cured static dissipative silicone compliant layer has a storage modulus of at least 1 and up to and including 100 MPa at 40° C.
8. The intermediate transfer member of claim 1 wherein the cured static dissipative silicone compliant layer has a storage modulus of at least 5 and up to and including 50 MPa at 40° C.