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

Patent metadata

Field	Value
Publication number	US-2016243774-A1
Application number	US-201414387192-A
Country	US
Kind code	A1
Filing date	Jun 16, 2014
Priority date	Jun 18, 2013
Publication date	Aug 25, 2016
Grant date	—

Abstract

There is provided a stretched laminate having superior optical characteristics, easily separable from a base film, and usable for manufacturing a thin polarizer. In addition, there are provided a method of manufacturing a thin polarizer having superior optical characteristics by using the stretched laminate, a thin polarizer manufactured by the method, and a polarizing plate including the thin polarizer.

First claim

1 . A stretched laminate formed by stretching a laminate comprising: a non-stretched polymer film; and a non-stretched polyvinyl alcohol-based film attached to at least one surface of the polymer film,
wherein both the polymer film and the polyvinyl alcohol-based film satisfy Formula 1 below in case of
x = film   thickness   after   stretching film   thickness   before   stretching   and   y = film   width   after   stretching film   width   before   stretching : y≦− 0.175 x+ 0.675  [Formula 1]

where 0.16≦x<1, and 0<y<1.

2 . The stretched laminate of claim 1 , wherein both the polymer film and the polyvinyl alcohol-based film further satisfy Formula 2 below:
−1.350 x+ 0.830≦ y   [Formula 2]
where 0.16≦x<1, and 0<y<1.

3 . The stretched laminate of claim 1 , wherein the polymer film comprises at least one selected from the group consisting of a high-density polyethylene film, a polyurethane film, a polypropylene film, a polyolefin film, an ester-based film, a film formed by coextruding high-density polyethylene and low-density polyethylene, a copolymerization resin film in which ethylene vinyl acetate is included in high-density polyethylene, an acrylic film, a polyethylene terephthalate film, a polyvinyl alcohol-based film, and a cellulose-based film.

4 . 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 polymer film; and stretching the laminate such that both the polymer film and the polyvinyl alcohol-based film satisfy Formula 1 below in case of below in case of
x = film   thickness   after   stretching film   thickness   before   stretching   and   y = film   width   after   stretching film   width   before   stretching : y≦− 0.175 x+ 0.675  [Formula 1]

where 0.16≦x<1, and 0<y<1.

5 . The method of claim 4 , wherein the stretching of the laminate is performed such that both the polymer film and the polyvinyl alcohol-based film satisfy Formula 2 below:
−1.350 x+ 0.830≦ y   [Formula 2]
where 0.16≦x<1, and 0<y<1.

6 . The method of claim 4 , wherein the forming of the laminate comprises attaching the non-stretched polymer film and the non-stretched polyvinyl alcohol-based film to each other by using attractive force therebetween or an adhesive.

7 . The method of claim 4 , wherein the stretching of the laminate is performed such that the polyvinyl alcohol-based film has a thickness of 60 μm or less before the stretching and a thickness of 10 μm or less after the stretching.

8 . The method of claim 4 , wherein the stretching of the laminate is performed within a temperature range of 20° C. to 80° C. at a stretching ratio of 5 times to 15 times.

9 . The method of claim 4 , wherein the stretching of the laminate is performed in an aqueous boric acid solution having a boric acid content of 1 wt % to 5 wt %.

10 . The method of claim 4 , wherein after the stretching of the laminate, an adhesive force between the stretched polyvinyl alcohol-based film and the stretched polymer film is 2 N/2 cm or less.

11 . The method of claim 4 , 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.

12 . The method of claim 4 , wherein after the stretching of the laminate, the method further comprises separating the stretched polyvinyl alcohol-based film from the stretched polymer film.

13 . The method of claim 12 , wherein the separating of the stretched polyvinyl alcohol-based film from the stretched polymer film is performed by applying peel force of 2 N/2 cm or less.

14 . (canceled)

15 . (canceled)

16 . (canceled)

Assignees

• Lg Chemical Ltd

Inventors

• Nam Sung-Hyun
• Jung Jong-Hyun
• Rah Kyun-Ii
• Yu Hye-Min

Classifications

• B32B2551/00

  Optical elements · CPC title

• B32B2457/206

  Organic displays, e.g. OLED · CPC title

• B32B27/32

  comprising polyolefins {(comprising vinyl (co)polymers or acrylic (co)polymers B32B27/30)} · CPC title

• B32B27/36

  comprising polyesters · CPC title

• B32B27/308

  comprising acrylic (co)polymers · CPC title