JP2013113887A - Method and device for recycling glass plate for color filter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and device for recycling a glass plate, which can remove a laminate material of a defective color filter without deteriorating a surface state by making the glass plate eroded, achieving inexpensive processing costs.SOLUTION: A method for recycling a glass plate for a color filter comprises the following steps in the course of continuously puting defective color filters in: an ultraviolet exposure step of photolyzing a resin film (positive type) made of a positive type photosensitive material; and an alkali cleaning step of removing the ultraviolet-exposed resin film (positive type).

Description

  The present invention removes an overcoat, a photo spacer, a colored pixel film, a black matrix, a transparent electrode, and the like from a color filter for display in which a colored pixel, a black matrix, an overcoat, a photo spacer, etc. are laminated on a glass plate, The present invention relates to a method for regenerating a glass plate for a color filter for recycling the glass plate.

  When producing color filters (CF) for large size liquid crystal displays, defective products that are out of specification are generated. CF is formed by forming a resin film, a conductive film, etc. on the glass plate. Defective products that deviate from the standard can be removed as a glass plate again by removing the film laminated on the glass plate surface. Used.

  As a method of easily peeling and regenerating the laminated film of the color filter in a short time without damaging the glass substrate, a step of pretreating with a pretreatment solution containing an inorganic acid, and a stripping solution containing an alkali A method for peeling a pixel on a glass substrate comprising a post-processing step is proposed (Patent Document 1).

  The color filter is a step of first forming a black matrix which is a resin film (negative type) on a glass plate, a step of applying and pre-drying a colored photoresist which is also a resin film (negative type), and drying the colored photoresist. From the pre-baking step for curing, the step of exposing, the step of developing, the step of curing the colored photoresist, the formation of the metal oxide conductive film, the patterning step, the overcoat that is a resin film (positive type), and the step of forming the photo spacer Become.

  The color filter to be manufactured must have high reliability, but as described above, there are many steps in the color filter manufacturing process, and the adhering / mixing of foreign matters such as dust and resin residue, pinholes, There is a current situation in which a defect due to a pattern defect or the like occurs, resulting in a defective substrate that does not meet quality standards, and the yield is reduced. In addition, due to the increase in size of glass substrates accompanying the recent widespread use of large-screen liquid crystal televisions, for example, glass substrates that are as thin as 1 mm or less and that have one side of 1 to 2 m or more have a risk in disposal itself.

  Thus, when a color filter manufacturing process that does not satisfy quality standards occurs, there is a need for a glass substrate recycling method that regenerates a glass substrate that is free from defects such as scratches and that can be re-entered and reused in the manufacturing process. .

  In the glass regeneration treatment, high-concentration alkali (concentration of 10% or more) is used when removing the resin film. Since alkali has an erosion action on the glass plate, using a high concentration alkali (concentration of 10% or more) for a long time will cause the surface of the glass plate to be eroded, leading to defective glass plate regeneration. Yes.

  In the CF glass plate regeneration treatment, the strength of the alkali treatment required for removing the resin film varies depending on the type of photosensitive resin (resist) used for forming the resin film and the state of the exposure treatment. When the type of resist used is negative, polymerization occurs in the exposed portion, and it cannot be removed with a low-concentration alkaline solution.

Therefore, the non-exposed portion of the negative resist can be developed with a relatively weak alkali treatment in the CF manufacturing process, but the resin film after the exposure treatment of the defective CF is removed by the glass plate regeneration treatment. Requires a strong alkali treatment. On the other hand, in the case of a positive resist, the photosensitive agent is oxidized and becomes soluble in alkali at the exposed portion.

  For this reason, the exposed resist portion of the positive resist can be developed with a relatively weak alkali treatment in the CF manufacturing process, but in order to remove the defective CF unexposed resin film by the glass plate regeneration process. A strong alkali treatment is required, and the surface of the glass plate is eroded, making it impossible to reuse the glass plate.

JP 2002-179438 A

  Chemicals such as inorganic acids and alkalis react with radicals even on glass materials, and surface conditions such as the roughness of the glass surface are deteriorated by the etching phenomenon, making it difficult to use as a liquid crystal glass substrate in many cases. . Therefore, in the end, it was discarded without being recycled. The present invention provides a glass plate regenerating method and a regenerating apparatus in which a laminated material of a color filter that is defective due to erosion of a glass plate is eliminated and a defective color filter can be removed, and the processing cost is low. There is.

  As means for solving the above-mentioned problems, the invention according to claim 1 is based on a positive photosensitive material in a color filter glass plate recycling step in which defective color filters are continuously fed. A glass plate for color filter, comprising: an ultraviolet exposure step for photodegrading a resin film (positive type) to be obtained; and an alkali cleaning step for removing the resin film (positive type) exposed to the ultraviolet ray Is the method.

  The invention according to claim 2 is the glass plate for a color filter according to claim 1, wherein the concentration of the low-concentration alkaline solution used in the alkali washing step is an alkaline solution of less than 10%. It is a playback method.

Further, the invention according to claim 3 is a glass plate regenerator for a color filter for continuously introducing defective color filters,
An ultraviolet exposure machine for irradiating ultraviolet rays onto a resin film (positive type) made of a positive photosensitive material;
An alkali washer that removes the resin film (positive type) irradiated with ultraviolet rays and ejects an alkaline solution having a concentration of less than 10%;
An etching machine for removing the conductive film;
An alkali washer that removes the resin film (negative type) and ejects an alkali solution having a concentration of 10% or more;
With water washing machine,
It is the glass plate reproduction | regeneration apparatus for color filters characterized by having.

Further, the invention according to claim 4 is connected to an alkali washer that ejects an alkali solution having a concentration of less than 10% and an alkali washer that ejects an alkali solution having a concentration of 10% or more,
The glass plate regenerator for a color filter according to claim 3, wherein a valve for introducing an alkali solution having a concentration of 10% or more is provided in an alkali washer that ejects the alkali solution having a concentration of less than 10%. It is.

  The present invention includes an ultraviolet exposure process in the glass filter regeneration process for continuously introducing defective color filters, and as a stripping solution for removing the resin film (positive type) 4, It is possible to use an alkali with a concentration (less than 10%), prevent erosion of the glass surface and reduce defects, and the use of a low concentration alkali reduces processing costs.

It is process drawing which showed the glass plate reproduction | regeneration method for color filters including the ultraviolet-ray exposure process of this invention, and the alkali washing | cleaning process using the low concentration alkaline solution which removes the color filter material which ultraviolet rays exposed and photolyzed. It is the flow which showed the glass plate reproduction | regeneration method for color filters of this invention. It is process drawing which showed the glass plate reproduction | regeneration method for color filters using the conventional high concentration alkali solution. It is the flow which showed the conventional glass plate regeneration method for color filters.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings. FIG. 1 shows a method for regenerating a glass plate for a color filter according to the present invention. The color filter is a laminate including a resin film (negative type) 2, a metal oxide conductive film 3, and a resin film (positive type) 4 on a glass plate 1. In the present invention, when the exposure lamp 5 irradiates ultraviolet rays, the resin film (positive type) 4 undergoes photolysis, and the resin of the resin film component becomes shorter, and until now, it did not dissolve unless a high concentration alkali was used. This is because it has been found that the resin film (positive type) 4 can be dissolved even in a low-concentration alkaline solution.

<UV exposure processing>
Exposure lamp: UV lamp (ultra-high pressure mercury lamp) Wavelength: 365 nm, 405 nm, 436 nm
Energy: 200 mW / cm ² or more
Exposure amount: 100 mJ / cm ² or more, exposure time: 0.5 sec or more Note that since the exposure time depends on the relationship between energy and exposure time, the exposure time increases as the energy decreases.

<Resin film (positive type)>
The layer in which the resin film (positive type) 4 is used is an overcoat (hereinafter referred to as OC) / photo spacer (hereinafter referred to as PS) layer.

  That is, for the resin film (positive type) 4 only, the resin film in the unexposed portion is exposed to an alkali treatment before the alkali treatment, so that the resin film is changed to an alkali-soluble film. It is possible to remove by weak alkali treatment. By this method, defective CF using resin film (positive type) 4 can use a relatively low concentration of alkali (concentration less than 10%), thus reducing the cost of glass plate regeneration and eroding the glass plate surface. It is possible to reduce glass plate regeneration failure by suppressing the above.

  When the low-concentration alkaline solution 7 is ejected from the shower 6 onto the light-irradiated color filter, the uppermost resin film (positive type) 4 of the defective color filter is dissolved and removed in the low-concentration alkaline solution 7. .

<Low concentration alkali treatment>
Low concentration alkaline solution: less than 5% KOH, less than 5% organic amine Temperature: 45-70 ° C. Flow rate: 150-300 L / min
As the organic amine, monoethanolamine and triethanolamine are suitable.

  Subsequently, the etching solution 8 is similarly ejected from the shower 6 to dissolve and remove the metal oxide conductive film 3.

<Metal oxide conductive film>
An ITO transparent electrode is preferred, but is not limited to this material.

<Etching treatment>
Etching solution: Ferric chloride 90% or more, nitric acid, hydrochloric acid or oxalic acid less than 10% Temperature: 45-70 ° C. Flow rate: 150-300 L / min
Subsequently, the high-concentration alkaline solution 9 is similarly ejected from the shower 6, the resin film (negative type) 2 is dissolved and removed, and finally, water 10 is ejected from the shower 6, and the resin or metal oxide conductive film 3 is removed. The residue, the etching solution 8 and the alkaline solution are removed, drained and dried to regenerate the glass plate.

<Resin film (negative type)>
The layer in which the resin film (negative type) 2 is used is a black matrix (hereinafter referred to as BM) or a colored pixel (red R, green G, blue B) (hereinafter referred to as RGB).

<High concentration alkali treatment>
High concentration alkali solution: KOH 5% or more, organic amine 5% or more Temperature: 45-70 ° C. Flow rate: 150-300 L / min
FIG. 2 is a flowchart of the method for regenerating a glass plate for a color filter according to the present invention, an ultraviolet exposure process for decomposing the resin film (positive type) 4, and a low concentration alkali process for removing the decomposed resin film (positive type) 4 3 shows a method comprising etching treatment for removing the metal oxide conductive film 3, high-concentration alkali treatment for removing the resin film (negative type) 2, and water washing treatment for washing away the residue of the crow plate.

  FIG. 3 shows a conventional method for regenerating a glass plate for a color filter. A highly concentrated alkaline solution 9 is ejected from the shower 6 to the defective color filter, the uppermost resin film (positive type) 4 is dissolved and removed, and then the etching solution 8 is also ejected from the shower 6. Then, the metal oxide conductive film 3 is dissolved and removed.

  Further, the same high-concentration alkaline solution 9 as the high-concentration alkaline solution 9 used when the resin film (positive type) 4 is dissolved is ejected from the shower 6 and the resin film (negative type) 2 is dissolved and removed. Finally, water 10 is ejected from the shower 6 to remove the residue of the resin and the metal oxide conductive film 3, the etching solution 8 and the alkaline solution, drain the water, and dry to regenerate the glass plate.

  FIG. 4 is a flowchart of a conventionally used method for regenerating a glass plate for a color filter, which is a high concentration alkali treatment for removing the resin film (positive type) 4, an etching treatment for removing the metal oxide conductive film 3, and a resin film. (Negative type) 2 Consists of a high-concentration alkali treatment to be removed and a water washing treatment for washing away the residue of the crow board. Unlike the method for regenerating a glass plate for a color filter according to the present invention, both the resin film (positive type) 4 and the resin film (negative type) 2 use the high concentration alkaline solution 9, so that the time for touching the high concentration alkali becomes longer. End up.

Alkali has the effect of eroding the glass plate, and if it is exposed to a high concentration of alkali for a long time, the glass surface tends to erode and a defective product is generated. However, resin film (positive type)
By irradiating with UV rays, it is possible to remove with low-concentration alkali that does not cause erosion of the glass surface, instead of high-concentration alkali that causes defective products. This shortens the time and reduces defects.

  The defective color filter has a different thermal history depending on the process that has become defective and removed. Depending on the color filter, the treatment with a low concentration alkali may be insufficient or the treatment time may be long, and is not applicable to all. Therefore, it is possible to cope with the conventional manner by switching the valve 11.

  High-concentration alkali is expensive and accounts for 60 to 80% of the cost for glass regeneration. It becomes possible to use a low-concentration alkali, the amount of chemicals used is reduced, and chemical costs, processing costs, etc. are reduced by 10 to 30%.

DESCRIPTION OF SYMBOLS 1 ... Glass plate 2 ... Resin film (negative type)
3 ... Metal oxide conductive film 4 ... Resin film (positive type)
5 ... exposure lamp 6 ... shower 7 ... low concentration alkaline solution 8 ... etching solution 9 ... high concentration alkaline solution 10 ... water 11 ... bulb

Claims (4)

  An ultraviolet exposure process for photodegrading a resin film (positive type) made of a positive photosensitive material in a glass plate recycling process for continuously adding the defective color filter into a color filter glass plate; A method for regenerating a glass plate for a color filter, comprising an alkali cleaning step of removing the exposed resin film (positive type).   The method for regenerating a glass plate for a color filter according to claim 1, wherein the concentration of the low-concentration alkaline solution used in the alkali cleaning step is an alkaline solution having a concentration of less than 10%. It is a glass plate regenerator for color filters that continuously introduce defective color filters,
An ultraviolet exposure machine for irradiating ultraviolet rays onto a resin film (positive type) made of a positive photosensitive material;
An alkali washer that removes the resin film (positive type) irradiated with ultraviolet rays and ejects an alkaline solution having a concentration of less than 10%;
An etching machine for removing the conductive film;
An alkali washer that removes the resin film (negative type) and ejects an alkali solution having a concentration of 10% or more;
With water washing machine,
A glass plate recycling apparatus for a color filter, comprising: Connecting an alkali washer that ejects an alkali solution having a concentration of less than 10% to an alkali washer that ejects an alkali solution having a concentration of 10% or more;
The glass plate regenerator for a color filter according to claim 3, wherein a valve for introducing an alkali solution having a concentration of 10% or more is provided in an alkali washer that ejects the alkali solution having a concentration of less than 10%. .