# US 6,719,940 B2 · White, biaxially oriented polyester film with cycloolefin copolymer and process for producing the film > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 6,719,940 B2 - Document ID: US6719940B2 - Status: Granted - Kind: B2 - Application number: 09/805,532 - Filed: 2001-03-13 - Published: 2002-03-21 - Granted: 2004-04-13 - Earliest claimed: 2000-03-16 - Assignees: Mitsubishi Polyester Film GmbH - Inventors: Jeffrey R. Rounsley - Web page: https://patentgrep.com/patent/US6719940B2 ## CPC - B29C 55/005: {characterised by the choice of materials} - B29C 55/06: parallel with the direction of feed - B29K 2023/38: {Polymers of cycloalkenes, e.g. norbornene or cyclopentene} - B29K 2067/00: Use of polyesters {or derivatives thereof}, as moulding material - B29K 2995/0022: Bright, glossy or shiny surface - B29C: SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING (making preforms B29B11/00; making laminated products by combining previously unconnected layers which become one product whose layers will remain together B32B37/00 - B32B41/00) - B29K: INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR {MOULDS, } REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS ## Abstract A method of controlling the gloss of a white biaxially oriented polyester film. The film will include at least one layer containing a cycloolefin copolymer at a concentration of about 4 to about 60% by weight of that layer. The method includes the step of stretching the film in a machine direction to a ratio of about 2.3 to about 3.4 to obtain desired gloss characteristics. ## Claims ### Claim 1 A method of controlling the gloss of a white, biaxially oriented polyester film, wherein said film comprises at least one layer containing a cycloolefin copolymer at a concentration of about 4 to about 60% by weight of said layer, said method including the step of: stretching said film in a machine direction to a ratio of about 2.3 to about 3.4. ### Claim 2 (depends on 1) The method of claim 1, wherein said film is stretched to a ratio of about 2.3 to about 2.6. ### Claim 3 (depends on 1) The method of claim 1, wherein said film is stretched to a ratio of about 2.6 to about 3.4. ### Claim 4 (depends on 1) The method of claim 1, wherein said film is stretched to a ratio of about 3.0 to about 3.4. ### Claim 5 (depends on 1) The method of claim 1, wherein a glass transition temperature of said cycloolefin copolymer is about 70 to about 270 degrees Celsius. ### Claim 6 (depends on 1) The method of claim 1, wherein said film has an opacity greater than about 60%. ### Claim 7 (depends on 1) The method of claim 1, wherein said film has a whiteness greater than about 70%. ### Claim 8 A method of forming a white, biaxially oriented polyester film having a gloss on at least one face of greater than about 70 at 20 degrees Celsius, wherein said film comprises at least one layer containing a cycloolefin copolymer at a concentration of about 4 to about 60% by weight of said layer, where the glass transition temperature of the cycloolefin copolymer is within the range from about 70 to about 270 degrees Celsius, said method including the step of: stretching said film in a machine direction to a ratio of about 3.0 to about 3.4. ### Claim 9 (depends on 8) The method of claim 8, wherein said film has a gloss on at least one face of greater than about 100 at 60 degrees Celsius. ### Claim 10 (depends on 8) The method of claim 8, wherein said film has a gloss on at least one face of greater than about 95 at 85 degrees Celsius. ### Claim 11 (depends on 1) The method of claim 1, wherein a machine direction draw ratio is selected to achieve a desired gloss of said film. ### Claim 12 A method of forming a white, biaxially oriented polyester film having a gloss on at least one face of less than about 50 at 20 degrees Celsius, wherein said film comprises at least one layer containing a cycloolefin copolymer at a concentration of about 4 to about 60% by weight of said layer, where the glass transition temperature of the cycloolefin copolymer is within the range from about 70 to about 270 degrees Celsius, said method including the step of: stretching said film in a machine direction to a ratio of about 2.3 to about 2.6. ### Claim 13 (depends on 12) The method of claim 12, wherein said film has a gloss on at least one face of less than about 20 at 20 degrees Celsius. ### Claim 14 (depends on 12) The method of claim 12, wherein said film has a gloss on both faces of less than about 20 at 20 degrees Celsius. ### Claim 15 (depends on 12) The method of claim 12, wherein said film has a gloss on at least one face of less than about 30 at 60 degrees Celsius.