# US 4,394,340 A · Method of producing thin-walled endless belt > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 4,394,340 A - Document ID: US4394340A - Status: Granted - Kind: A - Application number: 06/315,963 - Filed: 1981-10-28 - Granted: 1983-07-19 - Earliest claimed: 1980-10-29 - Assignees: Konishiroku Photo Industry Co., Ltd.; Hokushin Industries, Inc. - Inventors: Noriyoshi Tarumi; Hiroshi Tsuchiya; Masakazu Kokiso; Hiroaki Ohta - Web page: https://patentgrep.com/patent/US4394340A ## CPC - B29C 41/22: Making multilayered or multicoloured articles - B29C 41/042: {by rotating a mould around its axis of symmetry (for concrete B28B21/30)} - B29K 2079/00: Use of polymers having nitrogen, with or without oxygen or carbon only, in the main chain {, not provided for in groups B29K2061/00 - B29K2077/00}, as moulding material - B29K 2083/00: Use of polymers having silicon, with or without sulfur, nitrogen, oxygen, or carbon only, in the main chain, as moulding material - B29L 2031/7094: {Driving belts} - 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 - B29L: INDEXING SCHEME ASSOCIATED WITH SUBCLASS B29C, RELATING TO PARTICULAR ARTICLES ## Abstract An improved method of producing a thin-walled endless belt by centrifugal molding, which comprises introducing a liquid curable silicone rubber dissolved in a solvent into a rotating cylindrical mold, hardening said liquid curable silicone rubber to form a mold surface on the inner surface of said cylindrical mold, and thereafter introducing a thermosetting resin dissolved in a volatile solvent onto said mold surface to form the endless belt. ## Claims ### Claim 1 A method of producing a thin-walled endless belt having a thickness between 30 and 500 microns by centrifugal molding which comprises introducing a liquid curable silicone rubber dissolved in a solvent into a rotating cylindrical mold to coat the inner surface of said mold, hardening said liquid curable silicone rubber to form a silicone rubber coated mold surface on the inner surface of said cylindrical mold, and thereafter introducing into said rotating cylindrical mold a thermosetting resin which is at least one heat resistant resin selected from the group consisting of polyimide, polyamide-imide and polybenzimidazole resins dissolved in a volatile solvent onto said inner silicone rubber coated mold surface to coat said inner silicone rubber coated mold surface, then hardening said thermosetting resin and then removing said hardened thermosetting resin from said mold to form said endless belt having a thickness between 30 and 500 microns. ### Claim 2 (depends on 1) The method according to claim 1, wherein said liquid curable silicone rubber is at least one rubber selected from the group consisting of a heat curable silicone rubber and a cold-curable silicone rubber. ### Claim 3 (depends on 2) The method according to claim 2, wherein said liquid curable silicone rubber is at least one rubber selected from the group consisting of a dimethylpolysiloxane, a methylphenylpolysiloxane and a methylvinylpolysiloxane. ### Claim 4 (depends on 1) The method according to claim 1, wherein said solvent is an organic solvent. ### Claim 5 (depends on 4) The method according to claim 4, wherein said organic solvent is at least one solvent selected from the group consisting of a silicone oil, benzene, toluene and xylene. ### Claim 6 (depends on 1) The method according to claim 1, wherein said volatile solvent is at least one solvent from the group consisting of an N-methyl-2-pyrolidone and an N,N-dimethyl acetamide. ### Claim 7 (depends on 1) The method according to claim 1, wherein said liquid curable silicone rubber solution has a concentration of from 20 to 40% and a viscosity of from 0.1 to 5 P. ### Claim 8 (depends on 1) The method according to claim 1, wherein said thermosetting resin solution has a concentration of from 30 to 70% and a viscosity of from 0.5 to 5 P. ### Claim 9 (depends on 1) The method according to claim 1, wherein said liquid curable silicone rubber solution has a concentration of from 20 to 40% and a viscosity of from 0.1 to 5 P, and said thermosetting resin solution has a concentration of from 30 to 70% and a viscosity of from 0.5 to 5 P. ### Claim 10 (depends on 9) The method according to claim 9, wherein said solvent in which said liquid curable silicone rubber is dissolved is at least one solvent selected from the group consisting of a silicone oil, benzene, toluene and xylene, and wherein said volatile solvent is at least one solvent from the group consisting of an N-methyl-2-pyrolidone and an N,N-dimethyl acetamide. ### Claim 11 (depends on 10) The method according to claim 10, wherein said liquid curable silicone rubber is at least one rubber selected from the group consisting of a dimethylpolysiloxane, a methylphenylpolysiloxane and a methylvinylpolysiloxane. ### Claim 12 (depends on 1) The method according to claim 1, wherein said solvent in which said liquid curable silicone rubber is dissolved is at least one solvent selected from the group consisting of a silicone oil, benzene, toluene and xylene, and wherein said volatile solvent is at least one solvent from the group consisting of an N-methyl-2-pyrolidone and an N,N-dimethyl acetamide.