# US 8,771,825 B2 · Photo paper > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,771,825 B2 - Document ID: US8771825B2 - Status: Granted - Kind: B2 - Application number: 13/881,702 - Filed: 2010-10-29 - Published: 2013-08-22 - Granted: 2014-07-08 - Earliest claimed: 2010-10-29 - Assignees: Hewlett-Packard Development Company, L.P. - Applicants: Xulong Fu; Christine E. Steichen; Lokendra Pal; Ronald J. Selensky - Inventors: Xulong Fu; Christine E. Steichen; Lokendra Pal; Ronald J. Selensky - Web page: https://patentgrep.com/patent/US8771825B2 ## CPC - B41M 5/52: Macromolecular coatings - B32B 15/08: of synthetic resin - B32B 27/08: of synthetic resin - B32B 27/32: comprising polyolefins {(comprising vinyl (co)polymers or acrylic (co)polymers B32B27/30)} - B41M 5/502: {characterised by structural details, e.g. multilayer materials (supports, backcoats or intermediate layers for thermal dye transfer donor and receiver sheets B41M5/41, B41M5/42)} - B41M 5/506: {Intermediate layers} - B41M 5/5218: {characterised by inorganic additives, e.g. pigments, clays} - C04B 41/52: Multiple coating or impregnating {multiple coating or impregnating with the same composition or with compositions only differing in the concentration of the constituents, is classified as single coating or impregnation} - C08J 5/18: Manufacture of films or sheets - G03G 7/0013: {Inorganic components thereof} - B41M 2205/38: Intermediate layers; Layers between substrate and imaging layer - Y10T 428/24802: Discontinuous or differential coating, impregnation or bond [e.g., artwork, printing, retouched photograph, etc.] - Y10T 428/24851: Intermediate layer is discontinuous or differential - Y10T 428/24893: including particulate material - Y10T 428/252: Glass or ceramic [i.e., fired or glazed clay, cement, etc.] [porcelain, quartz, etc.] - B41M: PRINTING, DUPLICATING, MARKING, OR COPYING PROCESSES; COLOUR PRINTING, (correction of typographical errors B41J; processes for applying transfer pictures or the like B44C1/16; fluid media for correction of typographical errors by coating C09D10/00; printing textiles D06P) - B32B: LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM - C04B: LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE {(roofing granules E04D7/005)}; CERAMICS (devitrified glass-ceramics C03C10/00); REFRACTORIES; TREATMENT OF NATURAL STONE - C08J: WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H (working, e.g. shaping, of plastics B29) - G03G: ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract A sheet of photo paper comprises a substrate, a top coat deposited on the image receiving side of the substrate, a polyethylene coating deposited on the top coat, and an image receiving coating deposited on the polyethylene coating. A method of making a sheet of photo paper, comprising layering a pre-coat onto a substrate, layering a top coat onto the pre-coat, layering a polyethylene coating onto the top coat, and layering an image receiving coating onto the polyethylene coating. ## Claims ### Claim 1 Photo paper comprising: a substrate; a pre-coat deposited on the image receiving side of the substrate in which the pre-coat comprises ground calcium carbonate (GCC); a top coat deposited on the pre-coat; a polyethylene coating deposited on the top coat; and an image receiving coating deposited on the polyethylene coating. ### Claim 2 (depends on 1) The photo paper of claim 1, in which the pre-coat further comprises pigment having an average particle size of 1.5 μm or less. ### Claim 3 (depends on 1) The photo paper of claim 1, in which coat weight for the pre-coat has a coat weight of up to 25 gsm. ### Claim 4 (depends on 1) The photo paper of claim 1, in which the pre-coat further comprises a water dispersible binder, a water soluble binder, an optical brightener, a dye, or combinations thereof. ### Claim 5 (depends on 1) The photo paper of claim 1, in which the top coat further comprises a pigment having an average particle size of 0.5 μm or less. ### Claim 6 (depends on 5) The photo paper of claim 5, in which the pigment is a clay, calcium carbonate, plastic pigment, or combinations thereof. ### Claim 7 (depends on 1) The photo paper of claim 1, in which the top coat has a coat weight of up to 20 gsm. ### Claim 8 (depends on 1) The photo paper of claim 1 in which the polyethylene coating has a polyethylene (PE) weight of up to 30 grams per square meter. ### Claim 9 (depends on 1) The photo paper of claim 1 in which the surface roughness after the top coat has been deposited is less than 1.5 μm as measured by the Parker Print Surf method. ### Claim 10 A sheet of photo paper comprising: a substrate; a pre-coat deposited on the image receiving side of the substrate; a top coat deposited on the image receiving side of the substrate the top coat comprising precipitated calcium carbonate (PCC); a polyethylene coating deposited on the top coat; and an image receiving coating deposited on the polyethylene coating. ### Claim 11 (depends on 10) The photo paper of claim 10, in which the top coat further comprises a pigment having a particle size of 0.5 μm or less. ### Claim 12 (depends on 10) The photo paper of claim 10, in which the surface roughness after the top coat has been deposited is less than 2.5 μm as measured by the Parker Print Surf method. ### Claim 13 (depends on 10) The photo paper of claim 10, in which normalized distinctness of image (DOI) is greater or equal to 0.14 mm−1/gsm polyethylene (PE) weight. ### Claim 14 (depends on 10) The photo paper of claim 10, in which the polyethylene coating has coat weight of between 12 and 30 grams per square meter. ### Claim 15 (depends on 1) A method of making a sheet of the photo paper of claim 1, the method comprising: layering the pre-coat onto the substrate; layering the top coat onto the pre-coat; layering the polyethylene coating onto the top coat; and layering the image receiving coating onto the polyethylene coating.