# US 2013/0155362 A1 · Liquid crystal display panel, liquid crystal display device, and polymer for alignment film material > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2013/0155362 A1 - Document ID: US20130155362A1 - Status: Published application - Kind: A1 - Application number: 13/819,883 - Filed: 2011-08-23 - Published: 2013-06-20 - Earliest claimed: 2010-08-30 - Assignees: Sharp Kabushiki Kaisha - Inventors: Shinichi Terashita; Yuko Teraoka; Kouichi Matsuhashi; Akihito Jinda - Web page: https://patentgrep.com/patent/US20130155362A1 ## CPC - G02F 1/133711: {by organic films, e.g. polymeric films} - G02F 1/133723: {Polyimide, polyamide-imide} - G02F 1/133753: {with different alignment orientations or pretilt angles on a same surface, e.g. for grey scale or improved viewing angle} - G02F 1/133788: {by light irradiation, e.g. linearly polarised light photo-polymerisation} - G02F: OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS ## Abstract In a photo-alignment liquid crystal panel capable of achieving a uniform display quality and highly reliable photo-alignment properties, and excellent electro-optical properties (transmittance, contrast, viewing angle, and response) for improving a basic performance and a high image quality of a liquid crystal panel and a liquid crystal display device, a structural composition of a polymer, which is preferable as a photo-alignment film, is unclear. The invention optimizes a copolymerization ratio and a modification rate of a photopolymer in order for a compound having photo-alignment properties to be contained as the photo-alignment film so as to enable the photo-alignment film to have the photo-alignment properties, and achieves the discovery of a preferred structural composition of the polymer. An object of the invention is to efficiently produce and provide a display panel and a liquid crystal display device that have excellent electrical properties and optical properties, and have a sufficient liquid crystal display quality and reliability. ## Claims ### Claim 1 A liquid crystal display panel that has a configuration in which a liquid crystal layer containing liquid crystal molecules is interposed between a pair of substrates, and includes a photo-alignment film on a surface of at least one substrate on a liquid crystal layer side, wherein in the photo-alignment film, a film formed using an alignment film material containing a polymer is subjected to an alignment treatment by photo-irradiation, the polymer including a first constituent unit exhibiting a property of controlling alignment of the liquid crystal molecules by photo-irradiation and a second constituent unit exhibiting a property of controlling alignment of the liquid crystal molecules without photo-irradiation as essential constituent units; the first constituent unit exhibits the property of controlling alignment of the liquid crystal molecules by at least one photo-chemical reaction selected from a photo-cross-linking reaction and a photo-isomerization reaction; and an introduction ratio of a second constituent unit exceeds 4 mol % and is equal to or less than 10 mol % on the basis of 100 mol % of a total of the first constituent unit and the second constituent unit. ### Claim 2 (depends on 1) The liquid crystal display panel according to claim 1, wherein the introduction ratio of the second constituent unit is 8 mol % or less. ### Claim 3 (depends on 1) The liquid crystal display panel according to claim 1, wherein the photo-alignment film includes the film formed using the alignment film material and a film formed from a material other than the alignment film material, a surface portion of the photo-alignment film on a liquid crystal layer side is essentially composed of the film formed using the alignment film material, and in a case where a ratio of a solid-content of the material other than the alignment film material to 100 weight % of a solid-content of the alignment film material and the material other than the alignment film material is set to a modification rate, the modification rate exceeds 70 weight % and is equal to or less than 90 weight %. ### Claim 4 (canceled) ### Claim 5 (depends on 1) The liquid crystal display panel according to claim 1, wherein the photo-alignment film includes the film formed using the alignment film material and a film formed using a material other than the alignment film material, and a surface portion of the photo-alignment film on a liquid crystal layer side is essentially composed of the film formed using the alignment film material, and in a case where a ratio of a solid-content of the material other than the alignment film material to 100 weight % of a solid-content of the alignment film material and the material other than the alignment film material is set to a modification rate, when the introduction ratio of the second constituent unit exceeds 4 mol % and is equal to or less than 6 mol %, the modification rate exceeds 70 weight % and is equal to or less than 90 weight %, and when the introduction ratio of the second constituent unit exceeds 6 mol % and is equal to or less than 8 mol %, the modification rate is 83 to 90 weight %. ### Claim 6 (canceled) ### Claim 7 (depends on 1) The liquid crystal display panel according to claim 1, wherein the first constituent unit of the polymer in the alignment film material has a side chain having a photo-functional group. ### Claim 8 (depends on 1) The liquid crystal display panel according to claim 1, wherein the second constituent unit of the polymer in the alignment film material has a side chain having an alignment functional group. ### Claim 9 (depends on 1) The liquid crystal display panel according to claim 1, wherein the essential constituent unit of the polymer in the alignment film material has the same alignment control direction. ### Claim 10 (canceled) ### Claim 11 (depends on 1) The liquid crystal display panel according to claim 1, wherein the photo-alignment film is a vertical alignment film that performs a vertical alignment control of the liquid crystal molecules. ### Claim 12 (depends on 11) The liquid crystal display panel according to claim 11, wherein the second constituent unit of the polymer in the alignment film material has a side chain having a vertical alignment functional group. ### Claim 13 (depends on 11) The liquid crystal display panel according to claim 11, wherein the first constituent unit of the polymer in the alignment film material has a side chain having at least one photo-functional group selected from a group consisting of a coumarin group, a cinnamate group, a chalcone group, an azobenzene group, and a stilbene group. ### Claim 14 (depends on 11) The liquid crystal display panel according to claim 11, wherein the second constituent unit of the polymer in the alignment film material has a side chain having a steroid skeleton. ### Claim 15 (depends on 11) The liquid crystal display panel according to claim 11, wherein the second constituent unit of the polymer in the alignment film material has a side chain having a structure in which 3 to 4 rings selected from any one of 1-4-cyclohexylene and 1,4-phenylene are linearly coupled directly or through 1,2-ethylene. ### Claim 16 (depends on 11) The liquid crystal display panel according to claim 11, wherein the polymer in the alignment film material has a main chain structure of at least one selected from a group consisting of polyamic acid, polyimide, polyamide, and polysiloxane. ### Claim 17 (depends on 11) The liquid crystal display panel according to claim 11, wherein the essential constituent units of the polymer in the alignment film material are formed by diamine. ### Claim 18 (depends on 11) The liquid crystal display panel according to claim 11, wherein the polymer in the alignment film material is a copolymer of a monomer component that contains at least one of diamine, acid dianhydride, and dicarboxylic acid. ### Claim 19 (depends on 1) The liquid crystal display panel according to claim 1, wherein with regard to the polymer in the alignment film material, the monomer component of the second constituent unit exceeds 4 mol % and is equal to or less than 10 mol % on the basis of 100 mol % of a total amount of the monomer component of the first constituent unit and the monomer component of the second constituent unit. ### Claim 20 (depends on 1) The liquid crystal display panel according to claim 1, wherein the liquid crystal display panel includes pixels that are arranged in a matrix shape, each pixel having a pixel electrode disposed on one substrate on a liquid crystal layer side in a matrix shape, and a common electrode disposed on the other substrate on a liquid crystal layer side, and the pixel has two or more domains that are adjacently disposed. ### Claim 21 A liquid crystal display panel that has a configuration in which a liquid crystal layer containing liquid crystal molecules is interposed between a pair of substrates, and includes a photo-alignment film on a surface of at least one substrate on a liquid crystal layer side, wherein the photo-alignment film contains a polymer including a third constituent unit having a structure derived from a photo-functional group, and a fourth constituent unit that does not have the photo-functional group and the structure derived from the photo-functional group and has an alignment functional group as essential constituent units; and an introduction ratio of the fourth constituent unit exceeds 4 mol % and is equal to or less than 10 mol % on the basis of 100 mol % of a total of the third constituent unit and the fourth constituent unit. ### Claim 22 (canceled) ### Claim 23 (canceled) ### Claim 24 (depends on 1) A polymer for an alignment film material, the polymer comprising: a polymer including the first constituent unit and the second constituent unit as essential constituent units the polymer being contained in the alignment film material that forms the photo-alignment film provided to the liquid crystal display panel according to claim 1. ### Claim 25 (depends on 21) A polymer for an alignment film material, the polymer comprising: a polymer including the third constituent unit and the fourth constituent unit as essential constituent units, the polymer being contained in the alignment film material that forms the photo-alignment film provided to the liquid crystal display panel according to claim 21.