Carrier and developer
AssigneeXerox Corporation
InventorsBernard A. Kelly, Thomas C. Dombroski, Brian S. Giannetto, Brian E. Moore, Lloyd D. Spencer, Richard P. N. Veregin, Karen A. Moffat, Thomas E. Enright, Valerie M. Farrugia, Michael S. Hawkins, Wafa F. Bashir
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Abstract
Disclosed is a carrier suitable for use with an electrophotographic developer and an electrophotographic developer containing the carrier. In particular, the carrier is powder coated and comprises a copolymer of cyclohexylmethacrylate and dimethylaminoethylmethacrylate.
Claims18
A powder coated carrier for an electrophotographic developer comprising:
- (a) a ferrite core;
- and
- (b) a coating comprising:
- (i) a copolymer of cyclohexylmethacrylate and dimethylaminoethylmethacrylate, wherein the copolymer contains from about 0.8 to about 1.0 wt % dimethylaminoethylmethacrylate;
- (ii) a melamine-formaldehyde resin;
- and
- (iii) carbon black present in an amount of from about 9.2 to about 9.7 wt % of the coating;
- said coating being present in an amount of from about 0.85 to about 1.25 wt % of the carrier;
- said coated carrier having a conductivity of from about 8.9 to about 9.5 [log(mho/cm)], wherein the carrier core has a surface roughness of from about 0.163 to about 0.167 m2/g as measured by the BET (Brunauer Emmett Teller) method.
A developer composition comprising:
- (a) an emulsion aggregation toner comprising:
- (i) an amorphous polyester resin;
- (II) a crystalline polyester resin;
- (iii) a wax;
- and
- (iv) a colorant;
- and
- (b) a powder coated carrier comprising
- (i) a ferrite core;
- and
- (ii) a coating comprising:
- (A) a copolymer of cyclohexylmethacrylate and dimethylaminoethylmethacrylate, wherein the copolymer contains from about 0.8 to about 1.0 wt % dimethylaminoethylmethacrylate;
- (B) a melamine-formaldehyde resin;
- and
- (C) carbon black present in an amount of from about 9.2 to about 9.7 wt % of the coating;
- said coating being present in an amount of from about 0.85 to about 1.25 wt % of the carrier;
- said coated carrier having a conductivity of from about 8.9 to about 9.5 [Log(mho/cm)], wherein the carrier core has a surface roughness of from about 0.163 to about 0.167 m2/g as measured by the BET (Brunauer Emmett Teller) method, and further wherein the carrier exhibits a triboelectric (Q/m) at 8% Toner Concentration of at least about 32 microCoulombs/gram (μC/g).
A carrier for an electrophotographic developer made by a process which comprises:
- (a) preparing a latex copolymer of cyclohexylmethacrylate and dimethylaminoethylmethacrylate, wherein the copolymer contains from about 0.8 to about 1.2 wt % dimethylaminoethylmethacrylate;
- (b) preparing dry particles of the copolymer having a particle size of from about 80 to about 120 nm;
- (c) preparing a carrier coating by mixing the dry copolymer particles with:
- (i) carbon black, present in an amount of from about 9.2 to about 9.7 wt % of the carrier coating;
- and
- (ii) a melamine-formaldehyde resin;
- (d) mixing the carrier coating with ferrite cores;
- (e) heating the mixture of carrier coating and ferrite cores at a temperature of from about 385 to about 405° F. for a period of from about 20 to about 30 minutes, thereby fusing the carrier coating to the ferrite core;
- and
- (f) screening the coated carrier particles;
- said coated carrier particles having:
- (1) a coating weight of from about 0.85 to about 1.25 wt %;
- and
- (2) a conductivity of from about 8.9 to about 9.5 [Log(mho/cm)];
- and
- wherein the cores have a surface roughness of from about 0.163 to about 0.167 m2/q as measured by the BET (Brunauer Emmett Teller) method.
Dependencies are inferred from the claim text.