Receptor sheet for a toner developed electrostatic imaging process

Claim 1

An electrographic process for producing multicolored toned images in an electrostatic printer, comprising the steps of a) providing a flexible imaging sheet having at least one surface exhibiting dielectric properties and toner release properties characterized by a surface energy between 14 ergs/cm² and 20 ergs/cm², said surface energy comprising not more than 5% polar component, b) moving said imaging sheet at a substantially steady rate through the printer, c) producing on said surface of said imaging sheet a first electrostatic latent image corresponding to a first color by imagewise deposition of charges, d) developing said first latent image by means of a rotating applicator bar with a first toner corresponding to said first color to produce a first toned image, said first toned image then exhibiting a scratch test strength of not less than 40 g and a surface energy of not more than 50 ergs/cm², e) drying said first toned image, f) repeating steps c), d), and e) in sequence using toners corresponding to at least one more color to complete said multicolored toned image, so that where a later developed toner overlays an earlier developed toner the interface created between said earlier toner and said later toner has a work of adhesion value greater than the largest of work of adhesion values of interfaces created between said toners and said imaging sheet surface, and g) bringing said multicolor toned image deposited on said surface of said imaging sheet in contact with a receptor sheet surface under pressure and at an elevated temperature, so that said multitoned image is transferred to said receptor sheet surface without distortion, said receptor sheet surface having a surface energy greater than the surface energy of said imaging sheet surface, and said receptor sheet surface having a T g value between 10°C and 105°C and is at least 5°C below said elevated temperature, said receptor having a flexible substrate carrying said surface, said substrate comprising a polymer selected from the group consisting of acrylics, polyolefins, polyvinyl acetals, polyvinyl chloride film and polyurethane film, said film having a haze value of greater than 30% and a thickness of 30 to 500 micrometers.