Methods for manufacturing polarizing element, polarizing element roll and single sheet type polarizing element having local bleaching areas (as amended)

Patent metadata

Field	Value
Publication number	US-2016299271-A1
Application number	US-201515100420-A
Country	US
Kind code	A1
Filing date	Mar 25, 2015
Priority date	Mar 26, 2014
Publication date	Oct 13, 2016
Grant date	—

Abstract

The present invention relates to a method for manufacturing a polarizing element including locally bleached areas including steps of providing a polarizing element including a polyvinyl alcohol-based polarizer in which at least one of iodine and dichroic dye is oriented in a certain direction; forming a mask layer including at least one punched area on one surface of the polarizing element; partially bleaching the polarizing element formed with the mask layer by immersing the polarizing element into a bleaching solution; and correcting an appearance of the partially bleached polarizing element.

First claim

1 . A method for manufacturing a polarizing element including locally bleached areas comprising:
providing a polarizing element including a polyvinyl alcohol-based polarizer in which at least one of iodine and dichroic dye is oriented in a certain direction; forming a mask layer including at least one punched area on one surface of the polarizing element; partially bleaching the polarizing element formed with the mask layer by immersing the polarizing element into a bleaching solution; and correcting an appearance of the partially bleached polarizing element.

2 . The method for manufacturing a polarizing element including locally bleached areas of claim 1 , wherein the step of forming a mask layer includes forming a punched area on a mask film; and attaching the mask film on one surface of the polarizing element.

3 . The method for manufacturing a polarizing element including locally bleached areas of claim 2 , wherein the mask film is a polyethylene (PE) film, a polypropylene (PP) film, a polyethylene terephthalate (PET) film, an ethylene vinyl acetate (EVA) film or a polyvinyl acetate film.

4 . The method for manufacturing a polarizing element including locally bleached areas of claim 1 , wherein the step of forming a mask layer includes forming a coating layer on one surface of the polarizing element; and forming a punched area by selectively removing some areas of the coating layer.

5 . The method for manufacturing a polarizing element including locally bleached areas of claim 4 , wherein the coating layer is formed using a polymer resin composition or a photosensitive resin composition.

6 . The method for manufacturing a polarizing element including locally bleached areas of claim 4 , wherein the step of forming a punched area is carried out through laser machining

7 . The method for manufacturing a polarizing element including locally bleached areas of claim 1 , further comprising attaching a temporary protective film on the other side of the polarizing element.

8 . The method for manufacturing a polarizing element including locally bleached areas of claim 7 , wherein the temporary protective film is a polyethylene (PE) film, a polypropylene (PP) film, a polyethylene terephthalate (PET) film, an ethylene vinyl acetate (EVA) film or a polyvinyl acetate film.

9 . The method for manufacturing a polarizing element including locally bleached areas of claim 1 , wherein the bleaching solution is a strong basic solution having a pH of 11 to 14.

10 . The method for manufacturing a polarizing element including locally bleached areas of claim 9 , wherein the bleaching solution includes one or more types of bleaching agents selected from the group consisting of sodium hydroxide (NaOH), sodium hydrosulfide (NaSH), sodium azide (NaN 3 ), potassium hydroxide (KOH), potassium hydrosulfide (KSH) and potassium thiosulfate (KS 2 O 3 ).

11 . The method for manufacturing a polarizing element including locally bleached areas of claim 10 , wherein a concentration of the bleaching agent in the bleaching solution is from 1% by weight to 30% by weight.

12 . The method for manufacturing a polarizing element including locally bleached areas of claim 1 , wherein the partially bleaching step is carried out for 1 second to 60 seconds in a bleaching solution at 10° C. to 70° C.

13 . The method for manufacturing a polarizing element including locally bleached areas of claim 1 , further comprising removing the mask layer after the partially bleaching step.

14 . The method for manufacturing a polarizing element including locally bleached areas of claim 1 , wherein the step of correcting an appearance of the partially bleached polarizing element is carried out using a method of immersing the polarizing element into a crosslinking solution.

15 . The method for manufacturing a polarizing element including locally bleached areas of claim 14 , wherein the crosslinking solution includes one or more types of crosslinking agents selected from the group consisting of boric acid, borax, succinic acid, glutaric acid, and citric acid.

16 . The method for manufacturing a polarizing element including locally bleached areas of claim 1 , wherein the step of correcting an appearance of the partially bleached polarizing element is carried out by immersing the polarizing element into a neutralizing solution.

17 . The method for manufacturing a polarizing element including locally bleached areas of claim 16 , wherein the neutralizing solution includes one or more types of neutralizing agents selected from the group consisting of sulfuric acid, nitric acid, phosphoric acid, acetic acid, citric acid, hydrochloric acid, glutaric acid and succinic acid.

18 . The method for manufacturing a polarizing element including locally bleached areas of claim 1 , wherein the step of correcting an appearance of the partially bleached polarizing element is carried out by immersion into a crosslinking solution and immersion into a neutralizing solution.

19 . The method for manufacturing a polarizing element including locally bleached areas of claim 1 , further comprising washing and drying the polarizing element after the appearance correcting step.

20 . The method for manufacturing a polarizing element including locally bleached areas of claim 19 , wherein the drying in the washing and drying step is carried out using a heating roll having a diameter of 100Φ to 500Φ.

21 . The method for manufacturing a polarizing element including locally bleached areas of claim 20 , wherein a temperature of the heating roll is from 30° C. to 150° C.

22 . The method for manufacturing a polarizing element including locally bleached areas of claim 19 , wherein the drying in the washing and drying step is carried out by passing the polarizing element through a drying oven.

23 . The method for manufacturing a polarizing element including locally bleached areas of claim 1 , further comprising forming an optical layer on at least one surface of the polarizing element after the appearance correcting step.

24 . The method for manufacturing a polarizing element including locally bleached areas of claim 23 , wherein the optical layer is a protective film, a retardation film, a brightness enhancement film, a hard coating layer, an anti-reflection layer, a gluing layer, an adhesive layer or a combination thereof.

25 . A method for manufacturing a roll of a polarizing element including locally bleached areas comprising winding the polarizing element including locally bleached areas formed according to the manufacturing method of any one of claim 1 .

26 . A method for manufacturing a single sheet-type polarizing element comprising:
providing a polarizing element from the roll of the polarizing element including locally bleached areas manufactured according to the manufacturing method of claim 25 ; and cutting the polarizing element into a chip shape.

27 . The method for manufacturing a single sheet-type polarizing element of claim 26 , wherein the cutting step is carried out using a laser.

28 . The method for manufacturing a single sheet-type polarizing element of claim 27 , wherein the cutting step includes recognizing a location of a bleached area of the polarizing element; setting a cutting location based on the location of the bleached area; and carrying out the cutting at the cutting location using laser.

Assignees

• Lg Chemical Ltd

Inventors

• Lee Beom Seok
• Jang Eung Jin
• Rah Kyun Il
• Kang Hyung Koo
• Lee Byung Sun
• Choi Du Jin
• Yun Ho Jeong

Classifications

• B29K2029/04

  PVOH, i.e. polyvinyl alcohol (B29K2031/04 takes precedence) · CPC title

• B29D11/00644

  polarizing · CPC title

• B23K2103/50

  Inorganic materials other than metals or composite materials · CPC title

• B23K26/402

  involving non-metallic material, e.g. isolators · CPC title

• G02B5/3033 Primary

  in the form of a thin sheet or foil, e.g. Polaroid · CPC title