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-2016377777-A1
Application number	US-201515039709-A
Country	US
Kind code	A1
Filing date	Mar 25, 2015
Priority date	Mar 26, 2014
Publication date	Dec 29, 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 or more of iodine and dichroic dye is oriented in a certain direction; partially bleaching the polyvinyl alcohol-based polarizer by bringing a bleaching solution into contact with one surface of the polyvinyl alcohol-based polarizer through a printing method; 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; partially bleaching the polyvinyl alcohol-based polarizer by bringing a bleaching solution into contact with one surface of the polyvinyl alcohol-based polarizer through a printing method; 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 bleaching solution is a strong basic solution having a pH of 11 to 14.

3 . The method for manufacturing a polarizing element including locally bleached areas of claim 2 , 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 ).

4 . The method for manufacturing a polarizing element including locally bleached areas of claim 3 , wherein a concentration of the bleaching agent in the bleaching solution is from 1% by weight to 30% by weight.

5 . The method for manufacturing a polarizing element including locally bleached areas of claim 1 , wherein the bleaching solution has viscosity of 1 cps to 2000 cps.

6 . The method for manufacturing a polarizing element including locally bleached areas of claim 1 , wherein the partially bleaching step is carried out using a method of an inkjet marking method or a gravure printing method.

7 . 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.

8 . The method for manufacturing a polarizing element including locally bleached areas of claim 7 , 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.

9 . 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.

10 . The method for manufacturing a polarizing element including locally bleached areas of claim 9 , 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.

11 . 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.

12 . 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.

13 . The method for manufacturing a polarizing element including locally bleached areas of claim 12 , wherein the drying in the washing and drying step is carried out using a heating roll having a diameter of 100Φ to 500Φ.

14 . The method for manufacturing a polarizing element including locally bleached areas of claim 13 , wherein a temperature of the heating roll is from 30° C. to 150° C.

15 . The method for manufacturing a polarizing element including locally bleached areas of claim 14 , wherein the drying in the washing and drying step is carried out by passing the polarizing element through a drying oven.

16 . 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.

17 . The method for manufacturing a polarizing element including locally bleached areas of claim 16 , 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.

18 . 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 claim 1 .

19 . 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 18 ; and cutting the polarizing element into a single sheet form.

20 . The method for manufacturing a single sheet-type polarizing element of claim 19 , wherein the cutting step is carried out using a laser.

21 . The method for manufacturing a single sheet-type polarizing element of claim 20 , 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

• B23K2103/42

  Plastics other than composite materials · CPC title

• B29D11/00644

  polarizing · CPC title

• B29D11/00865

  Applying coatings; tinting; colouring (printing, marking or copying processes B41M; identification in general G09F3/00; producing decorative effects in general B44C; positioning or marking of lenses B24B13/0055) · CPC title

• B23K26/38

  by boring or cutting · CPC title

• B23K26/402

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