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US 10,534,282 B2Granted
Charge roller
AssigneeHewlett-Packard Development Company, L.P.
InventorsYi Feng, Stanley J. Kozmiski, Shao-Wei Li
Life of this patent
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Abstract
The present disclosure discloses a charge roller (1) particularly but not exclusively for charging a photoconductor in a liquid electro-photograph (LEP) image-forming apparatus. The charge roller includes a cured composition of an epichlorohydrin/ethylene oxide/allyl glycidyl ether terpolymer, a lithium salt and carbon black.
Claims13
A charge roller comprising a rubber, said rubber being obtainable by curing a composition comprising:
- a terpolymer of epichlorohydrin/ethylene oxide/allyl glycidyl ether which has:
- an epichlorohydrin content which results in a terpolymer chlorine content comprised between about 18 and 20% by weight over the weight of the terpolymer, an allyl glycidyl ether content comprised between about 6.2 and 8.2% by weight over the weight of the terpolymer, the balance being ethylene oxide, and
- a Mooney viscosity comprised between about 40 and 54 when expressed as ML (1′+4′) and measured using ASTM D-1646 method,
- lithium(bis)trifluoromethanesulfonimide,
- carbon black,
- a curing activator comprising:
- stearic acid in an amount of 0.5 weight parts per 100 terpolymer weight parts, and zinc oxide in powder form in an amount of 3 weight parts per 100 terpolymer weight parts,
- a curing accelerator comprising:
- a dispersion of 75% w/w of zinc dimethylthiocarbamate in a polymer-based binder in an amount of 1.2 weight parts per 100 terpolymer weight parts, tetramethylthiuram monosulfide in an amount of 0.4 weight parts per 100 terpolymer weight parts, and 2, 2′-dithiobis(benzothiazole) in an amount of 1 weight parts per 100 terpolymer weight parts, and
- a sulfur donor comprising:
- a dispersion in the form of beads of 70% w/w 4,4′-dithiodimorpholine in an amount of 1.75 weight parts per 100 terpolymer weight parts,
- wherein the amount of lithium(bis)trifluoromethanesulfonimide in the composition is comprised between 1 and 4 expressed as weight parts per 100 weight parts of said terpolymer,
- wherein the amount of carbon black in the composition is comprised between 1 and 4 expressed as weight parts per 100 weight parts of said terpolymer, and
- wherein the rubber has an impedance at 8 KHz comprised between 10 and 20 KΩ and a DC resistance comprised between 30 and 50 KΩ when both impedance and resistance are measured by using an electrode of 323 mm long and 2 mm wide and an electrical source of 100V, in a rubber stabilized at 50% relative humidity and 23° C.
11 more elements
A method of using a combination of carbon black and a lithium salt as conductive agent in a rubber composition containing an epichlorohydrin/ethylene oxide/allyl glycidyl ether terpolymer, a sulfur donor, a curing activator, and a curing accelerator, the method comprising:
- mixing the carbon black, the lithium salt, the epichlorohydrin/ethylene oxide/allyl glycidyl ether terpolymer to form the rubber composition,
- wherein the lithium salt is lithium(bis)trifluoromethanesulfonimide,
- wherein the epichlorohydrin/ethylene oxide/allyl glycidyl ether terpolymer comprises:
- an epichlorohydrin content which results in a terpolymer chlorine content comprised between about 18 and 20% by weight over the weight of the terpolymer, an allyl glycidyl ether content comprised between about 6.2 and 8.2% by weight over the weight of the terpolymer, the balance being ethylene oxide, and
- a Mooney viscosity comprised between about 40 and 54 when expressed as ML (1′+4′) and measured using ASTM D-1646 method,
- wherein the amount of lithium(bis)trifluoromethanesulfonimide in the composition is comprised between 1 and 4 expressed as weight parts per 100 weight parts of said terpolymer,
- wherein the amount of carbon black in the composition is comprised between 1 and 4 expressed as weight parts per 100 weight parts of said terpolymer
- wherein the curing activator comprises:
- stearic acid, which is present in an amount of 0.5 weight parts per 100 terpolymer weight parts, and zinc oxide in powder form, which is present in an amount of 3 weight parts per 100 terpolymer weight parts,
- wherein the curing accelerator comprises:
- a dispersion of 75% w/w of zinc dimethylthiocarbamate, which is present in a polymer-based binder in an amount of 1.2 weight parts per 100 terpolymer weight parts, tetramethylthiuram monosulfide, which is present in an amount of 0.4 weight parts per 100 terpolymer weight parts, and 2,2′-dithiobis(benzothiazole), which is present in an amount of 1 weight parts per 100 terpolymer weight parts, and
- wherein the sulfur donor comprises:
- a dispersion in the form of beads of 70% w/w 4,4′-dithiodimorpholine, which is present in an amount of 1.75 weight parts per 100 terpolymer weight parts;
- and
- curing the rubber composition,
- wherein the rubber has an impedance at 8 KHz comprised between 10 and 20 KΩ and a DC resistance comprised between 30 and 50 KΩ when both impedance and resistance are measured by using an electrode of 323 mm long and 2 mm wide and an electrical source of 100V, in a rubber stabilized at 50% relative humidity and 23° C.
13 more elements
Dependencies are inferred from the claim text.