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AssigneeRicoh Company, Ltd.
InventorsYuji Sawai, Hisayuki Ushiyama, Tsuiki, deceased Harunobu, by Noriko Tsuiki, a legal representative, Tomohiro Tsuiki, legal representive, Manami Tsuiki, legal representive, Tadashi Fujii, Eiichi Akutsu, Itsuo Ikeda
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A pressure sensitive adhesive toner for use in electrostatic photography which consists essentially of porous aggregates. Each aggregate consists essentially of a cluster of a multiplicity of individual granules of pressure sensitive adhesive substance, each granule being encapsulated by a coating film of a film-forming material. Particles of an inorganic or organic pigment and/or a magnetic substance are contained within the aggregate in the interstices between the granules and deposited on the surfaces of the encapsulated granules. The toner aggregates are free from a tendency to cohere, cake and agglomerate to each other. The toner can be readily pressure fixed, using a low impression pressure, onto a surface bearing an electrostatic latent image without causing any contamination thereon, thereby forming a distinct visible image.
A pressure-sensitive adhesive toner for use in electrostatic photography consisting essentially of porous particles having a mean particle size of about 5 to 30 microns, each of said porous particles consisting essentially of a cluster of a plurality of granules wherein each of said granules has a core of pressure-sensitive adhesive substance encapsulated by a thin coating film of encapsulating material, said pressure-sensitive adhesive substance being solid at room temperature, having a modulus of elasticity of less than 10.sup.10 dyne/cm.sup.2 and a blocking-initiating temperature of lower than 50.degree. C., said encapsulating material having a blocking-initiating temperature of higher than 50.degree. C., said granules being adhered together to form said porous particle, said granules also containing a material selected from the group consisting of inorganic pigment particles, organic pigment particles, magnetic particles and mixture thereof, said toner having been prepared by spray-drying an aqueous dispersion of said granules containing said material, whereby said toner can be fixed by mechanically pressing and thereby breaking said porous particles.
A pressure-sensitive adhesive toner for use in electrostatic photography consisting essentially of approximately spherical porous particles having a rough surface, a mean particle size of about 5 to 30 microns, a porosity of about 5 to 50% and a specific gravity of about 0.9 to 2.9, each of said porous particles consisting essentially of a cluster of a multiplicity of individual granules wherein each of said granules has a core of pressure-sensitive adhesive substance encapsulated by a thin frangible coating film of encapsulating material, said pressure-sensitive adhesive substance being solid at room temperature, having a modules of elasticity of less than 10.sup.10 dyne/cm.sup.2 and a blocking-initiating temperature of lower than 50.degree. C., said encapsulating material having a blocking-initiating temperature of higher than 50.degree. C., the surfaces of said granules being adhered together at the locations where they contact each other with spaces being formed where said granules are not in contact with each other whereby said porous particle is unitary and shape-retaining but is crushable when a fixing pressure is applied thereon, said porous particle having a material selected from the group consisting of inorganic pigment particles, organic pigment particles, magnetic particles and mixture thereof randomly dispersed in said spaces and adhered to the encapsulating films of said granules, the ratio of said pressure-sensitive adhesive substance to said material being in the range of 1/20 to 20/1 parts by weight, said toner having been prepared by spray-drying an aqueous dispersion of said granules containing said material, whereby said toner can be fixed by mechanically pressing and thereby breaking said porous particles into separate granules and the encapsulating films of said granules are also broken to release said pressure-sensitive adhesive, said pressure-sensitive adhesive substance being selected from the group consisting of the following (1) to (7),
Dependencies are inferred from the claim text.