Electrostatic developer mix containing either MoS2, TiS2, WS.sub.2

Claim 2

A dry developer mix for developing electrostatic latent images comprising a mixture of carrier particles and pigmented thermoplastic resin toner particles and a particulate material additive selected from the group consisting of molybdenum disulfide, titanium disulfide, tungsten disulfide and graphite, and present in said developer mix in the range of from about 0.005 to about 1.0 weight percent based on the weight of said carrier particle, whereby said developer mix is capable of resisting fatigue for prolonged periods of time under high output duplicating machine conditions.

Claim 3

The developer mix as defined in claim 1 wherein said additive is molybdenum disulfide.

Claim 4

The developer mix as defined in claim 2 wherein said molybdenum disulfide is present in an amount within the range of about 0.05 to about 0.15 weight percent based on the weight of carrier particles.

Claim 5

A dry developer mix having improved fatigue resistance for developing electrostatic latent images comprising a mixture of carrier particles having an average particle size in the range of about 25 to 500 microns, toner particles having an average size smaller than that of said carrier particles, said toner particles consisting essentially of pigmented thermoplastic resin having an average size within the range of about 1 to about 10 microns, the relative proportion of carrier and toner particles being within the range of 10:1 to 100:1, and having included in said mix a particulate material additive from about 0.005 to about 1.0 weight percent selected from the group consisting of molybdenum disulfide, titanium disulfide, tungsten disulfide and graphite, based on the weight of said carrier particles.

Claim 6

A dry developer mix having improved fatigue resistance for developing electrostatic latent images comprising a mixture of carrier particles having an average particle size in the range of about 25 to 500 microns, toner particles having an average size smaller than that of said carrier particles, said toner particles consisting essentially of pigmented thermoplastic resin having an average size within the range of about 1 to about 10 microns, the relative proportion of carrier and toner particles being within the range of 10:1 to 100:1, and having included in said mix a particulate material additive from about 0.005 to about 1.0 weight percent selected from the group consisting of molybdenum disulfide, titanium disulfide, tungsten disulfide and graphite, based on the weight of said carrier particles.

Claim 7

In a dry developer mix for developing an electrostatic latent image on photoconductive, insulating material, comprising magnetic carrier particles and pigmented thermoplastic resin toner particles, the improvement resulting in a developer mix capable of resisting fatigue for prolonged periods of time under high output duplicating conditions, comprising from about 0.005 to about 1.0 weight percent of a particulate material additive selected from the group consisting of molybdenum disulfide, titanium disulfide, tungsten disulfide and graphite, based on the weight of said magnetic carrier particles.

Claim 8

In a dry developer mix for developing an electrostatic latent image on photoconductive, insulating material, comprising magnetic carrier particles and pigmented thermoplastic resin toner particles, the improvement resulting in a developer mix capable of resisting fatigue for prolonged periods of time under high output duplicating conditions, comprising from about 0.005 to about 1.0 weight percent of a particulate material additive selected from the group consisting of molybdenum disulfide, titanium disulfide, tungsten disulfide and graphite, based on the weight of said magnetic carrier particles.

Claim 9

The developer mix as defined in claim 5 wherein said additive is molybdenum disulfide and is present in an amount within the range of about 0.09 to about 0.15 weight percent based on the weight of said magnetic carrier particles.

Claim 12

The method as set forth in claim 7 wherein said additive is molybdenum disulfide and is present in an amount ranging from 0.09 to about 0.15 weight percent based on the weight of said carrier particles.

Claim 13

The method as set forth in claim 8 wherein said developer mix comprises a mixture of magnetic carrier particles having an average particle size within the range of about 25 to 300 microns, toner particles having an average size smaller than that of said magnetic carrier particles, said toner particles consisting essentially of pigmented thermoplastic resin having an average size within the range of about 1 to about 10 microns, the relative weight proportion of magnetic carrier and toner particles being in the range of 10:1 to 100:1, and from about 0.009 to about 0.2% of molybdenum disulfide based on the weight of said magnetic carrier particles.