# US 8,787,722 B2 · Optical waveguide > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,787,722 B2 - Document ID: US8787722B2 - Status: Granted - Kind: B2 - Application number: 13/119,800 - Filed: 2009-09-18 - Published: 2011-10-27 - Granted: 2014-07-22 - Earliest claimed: 2008-09-19 - Assignees: Hitachi Chemical Company, Ltd. - Applicants: Toshihiko Takasaki; Masatoshi Yamaguchi; Toshihiro Kuroda; Tatsuya Makino; Masami Ochiai; Atsushi Takahashi - Inventors: Toshihiko Takasaki; Masatoshi Yamaguchi; Toshihiro Kuroda; Tatsuya Makino; Masami Ochiai; Atsushi Takahashi - Web page: https://patentgrep.com/patent/US8787722B2 ## CPC - G02B 6/1221: {made from organic materials} - B29D 11/00663: {Production of light guides} - B29D 11/00673: {Supports for light guides} - G02B 6/122: Basic optical elements, e.g. light-guiding paths - G02B 6/125: Bends, branchings or intersections - B29L 2011/0075: {Light guides, optical cables} - G02B 2006/12097: {Ridge, rib or the like} - G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS - B29D: PRODUCING PARTICULAR ARTICLES FROM PLASTICS OR FROM SUBSTANCES IN A PLASTIC STATE (making granules B29B9/00; making preforms B29B11/00) - B29L: INDEXING SCHEME ASSOCIATED WITH SUBCLASS B29C, RELATING TO PARTICULAR ARTICLES ## Abstract An optical waveguide contains a lower cladding layer, a patterned core layer, an upper cladding layer and an upper low elasticity layer, which are laminated in this order, in which a film formed by curing a resin composition for forming the upper low elasticity layer has a tensile elastic modulus of from 1 to 2,000 MPa at 25° C., and a cured film having a thickness of 110 μm formed by curing a resin composition for forming the upper cladding layer has a total light transmittance of 90% or more. An optical waveguide that has good flexural resistance and good optical characteristics can be provided. ## Claims ### Claim 1 An optical waveguide comprising a lower cladding layer, a patterned core layer having peripheral surfaces and a thickness from 30 to 70 μm, an upper cladding layer having portions disposed to surround the peripheral surfaces of the patterned core layer and having an average thickness of 3 to 20 μm, and an upper low elasticity layer, which are laminated in this order, wherein a film formed by curing a resin composition for forming the upper low elasticity layer has a tensile elastic modulus of from 1 to 2,000 MPa at 25° C., and wherein the upper cladding layer is formed from a resin composition that has a total light transmittance of 90% or more when cured to form a film having a thickness of 110 μm. ### Claim 2 (depends on 1) The optical waveguide according to claim 1, wherein the optical waveguide further comprises a lower low elasticity layer, wherein the lower low elasticity layer, the lower cladding layer, the patterned core layer, the upper cladding layer and the upper low elasticity layer are laminated in this order, and wherein a film formed by curing a resin composition for forming the lower low elasticity layer has a tensile elastic modulus of from 1 to 2,000 MPa at 25° C. ### Claim 3 (depends on 1) The optical waveguide according to claim 1, wherein the optical waveguide has a relative refractive index difference between the core layer and the cladding layer of from 1 to 10%. ### Claim 4 (depends on 1) The optical waveguide according to claim 1, wherein a film formed by curing a resin composition for forming the upper low elasticity layer has a tensile yield elongation of from 5 to 600% at 25° C. ### Claim 5 (depends on 1) The optical waveguide according to claim 1, wherein the resin composition for forming the upper low elasticity layer contains a rubber component. ### Claim 6 (depends on 5) The optical waveguide according to claim 5, wherein the rubber component is acrylic rubber and/or acrylonitrile-butadiene rubber. ### Claim 7 (depends on 1) The optical waveguide according to claim 1, wherein the upper low elasticity layer has an average thickness of from 5 to 100 μm. ### Claim 8 (depends on 2) The optical waveguide according to claim 2, wherein the lower low elasticity layer has an average thickness of from 5 to 100 μm. ### Claim 9 (depends on 1) The optical waveguide according to claim 1, wherein the portions of the upper cladding layer disposed to surround the peripheral surfaces of the patterned core layer are embedded in the upper low elasticity layer. ### Claim 10 An optical waveguide, comprising: a lower cladding layer; a patterned core layer above the lower cladding layer, the patterned core layer having peripheral surfaces; an upper cladding layer above the lower cladding layer, the upper cladding layer having portions disposed upon the peripheral surfaces of the patterned core layer, and the upper cladding layer formed from a resin composition that has a total light transmittance of 90% or more when cured to form a film having a thickness of 110 μm; and an upper low elasticity layer in which the portions of the upper cladding layer disposed upon the peripheral surfaces of the patterned core layer are embedded, wherein a film formed by curing a resin composition for forming the upper low elasticity layer has a tensile elastic modulus of from 1 to 2,000 MPa at 25° C. ### Claim 11 (depends on 10) The optical waveguide according to claim 10, wherein the patterned core layer has a thickness and the upper cladding layer has a thickness less than the thickness of the core layer. ### Claim 12 (depends on 11) The optical wave guide according to claim 11, wherein the patterned core layer has a thickness of 30 to 70 μm, and wherein the upper cladding layer has an average thickness of 3 to 20 μm. ### Claim 13 (depends on 10) The optical waveguide according to claim 10, wherein the optical waveguide further comprises, a lower low elasticity layer below the lower cladding layer, wherein a film formed by curing a resin composition for forming the lower low elasticity layer has a tensile elastic modulus of from 1 to 2,000 MPa at 25° C. ### Claim 14 (depends on 10) The optical waveguide according to claim 10, wherein the optical waveguide has a relative refractive index difference between the core layer and the cladding layer of from 1 to 10%. ### Claim 15 (depends on 10) The optical waveguide according to claim 10, wherein a film formed by curing a resin composition for forming the upper low elasticity layer has a tensile yield elongation of from 5 to 600% at 25° C. ### Claim 16 (depends on 10) The optical waveguide according to claim 10, wherein the resin composition for forming the upper low elasticity layer contains a rubber component. ### Claim 17 (depends on 16) The optical waveguide according to claim 16, wherein the rubber component is acrylic rubber and/or acrylonitrile-butadiene rubber. ### Claim 18 (depends on 10) The optical waveguide according to claim 10, wherein the upper low elasticity layer has an average thickness of from 5 to 100 μm. ### Claim 19 (depends on 13) The optical waveguide according to claim 13, wherein the lower low elasticity layer has an average thickness of from 5 to 100 μm.