IP Library Granted Patent US 10,254,457
Granted Patent B2
US 10,254,457 · App. 14/387,070 · Granted Apr 9, 2019

Stretched laminate, method of manufacturing thin polarizer, thin polarizer manufactured by the method, and polarizing plate including the thin polarizer

Inventors: Sung-Hyun Nam (Daejeon, KR); Jong-Hyun Jung (Daejeon, KR); Kyun-Il Rah (Daejeon, KR); Hye-Min Yu (Daejeon, KR)
Assignee: LG CHEM, LTD.
G02B5/305B29C55/005B29C55/023B32B7/12B32B27/08B32B27/306B32B27/40B29K2029/00B29K2075/00B29L2011/0066B32B37/12B32B43/006B32B2038/0028B32B2274/00B32B2307/4026B32B2307/414B32B2307/42B32B2307/514B32B2307/54B32B2307/582B32B2307/732B32B2309/105B32B2551/00
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Quick Facts
Patent No.
US 10,254,457
App. No.
14/387,070
Granted
Apr 9, 2019
Kind
B2
Abstract

There is provided a stretched laminate formed by stretching a laminate including: a non-stretched thermoplastic polyurethane film; and a non-stretched polyvinyl alcohol-based film attached to at least one surface of the thermoplastic polyurethane film, wherein the polyvinyl alcohol-based film has a thickness of 10 μm or less after stretching. In addition, there are provided a method of manufacturing a thin polarizer using the stretched laminate, a thin polarizer manufacturing by the method, and a polarizing plate including the thin polarizer.

Claims (14)

1. A method of manufacturing a thin polarizer, the method comprising:

forming a laminate by attaching a non-stretched polyvinyl alcohol-based film to at least one surface of a non-stretched thermoplastic polyurethane film while unwinding a roll of the non-stretched thermoplastic polyurethane film and a roll of the non-stretched polyvinyl alcohol-based film; and

stretching the laminate until the polyvinyl alcohol-based film has a thickness of 10 μm or less, and

separating the stretched polyvinyl alcohol-based film from the stretched thermoplastic polyurethane film by applying a peel force in a range of 0.1 to 2N/2 cm,

wherein the forming of the laminate comprises attaching together the non-stretched thermoplastic polyurethane film and the non-stretched polyvinyl alcohol-based film by using attractive force therebetween or an adhesive, and

wherein after the stretching of the laminate, adhesive force between the stretched polyvinyl alcohol-based film and the stretched thermoplastic polyurethane film is 2 N/2 cm or less,

wherein the stretching of the laminate is performed within a temperature range of 40° C. to 60° C. at a stretching ratio of 6 times to 9 times,

wherein the thickness of the thermoplastic polyurethane film is 30 μm to 60 μm before stretching,

wherein the non-stretched thermoplastic polyurethane film has a glass transition temperature of 30° C. to 50° C.,

wherein the non-stretched thermoplastic polyurethane film has a modulus of 200 MPa to 1500 MPa, and

wherein the non-stretched thermoplastic polyurethane film has a breaking force of 5N to 40N.

2. The method of claim 1 , wherein the stretching of the laminate is performed in an aqueous boric acid solution having a boric acid concentration of 1 wt % to 5 wt %.

3. The method of claim 1 , wherein after the stretching of the laminate, a width of the thermoplastic polyurethane film measured in a direction perpendicular to a stretching direction is reduced by 30% to 80% as compared to that of the thermoplastic polyurethane film measured before the stretching, and a thickness of the thermoplastic polyurethane film is reduced by 30% to 80% as compared to that of the thermoplastic polyurethane film measured before the stretching.

4. The method of claim 1 , wherein before the stretching of the laminate, the method further comprises dyeing the non-stretched polyvinyl alcohol-based film with one or more of iodine and a dichroic dye.

Assignments (2)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Mar 26, 2025
From: LG CHEM LTD.
To: SHANJIN OPTOELECTRONICS (SUZHOU) CO., LTD.
Reel/Frame 070629/0281 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Sep 22, 2014
From: NAM, SUNG-HYUN; JUNG, JONG-HYUN; RAH, KYUN-IL; YU, HYE-MIN
To: LG CHEM, LTD.
Reel/Frame 033789/0809 →
Priority Claims (2)
KR 10-2013-0069832 · Jun 18, 2013 · national
KR 10-2014-0071686 · Jun 12, 2014 · national
Continuity (1)
Related Publication 20160085005A1 · Mar 24, 2016