JP3503129B2 - Release agent for color filter layer and method for recycling glass substrate for color filter - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stripping agent for stripping a color filter layer from a defective substrate generated in a color filter manufacturing process, and a method for reclaiming a glass substrate for a color filter using the stripping agent. Regarding

[0002]

2. Description of the Related Art There are various methods for colorizing a liquid crystal display, but at present, a method using a color filter is predominant. Since such a color filter requires high reliability and high precision, the inspection of the product must be strict and the defective rate of the product becomes high, resulting in a high yield of the color filter. The current situation is that it is decreasing. Such a reduction in the yield of color filter production accounts for a large factor in the high cost of the liquid crystal display, and there is a demand for cost reduction of color filter production.

As a means for reducing the cost of manufacturing color filters, defects caused by the inclusion of foreign matter such as dust, defects caused by pinholes or chips, defects caused by defective flatness of the glass substrate, which cause defective products, are mentioned. It is conceivable to improve the yield of color filter manufacturing by improving the above. However, it is difficult to completely eliminate these defects, and it is not industrially advantageous to strictly control the manufacturing process to completely eliminate these causes.

Further, as a means for reducing the cost of manufacturing the color filter, there is a method of separating the color filter layer from the defective substrate of the color filter and recycling the glass substrate for the color filter for reuse. As a method for recycling such a glass substrate for a color filter, there is, for example, an alkali treatment method using an aqueous solution of sodium hydroxide as a release agent. However, the alkali treatment method has a problem that it takes a long time to peel off the color filter layer, and when the color filter layer is peeled off, other materials such as a glass substrate are damaged.

[0005]

DISCLOSURE OF THE INVENTION The present invention uses a stripping agent for efficiently stripping a color filter layer from a defective substrate of a color filter without damaging other materials such as a glass substrate, and the stripping agent. It is an object of the present invention to provide a method for reclaiming a glass substrate for a color filter.

[0006]

Means for Solving the Problems As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that the above-mentioned objects can be achieved by using the following specific release agents. The invention was completed.

That is, the present invention relates to an alkanediol having 2 to 8 carbon atoms (A) of 20 to 80% by weight , an amphoteric surfactant (B) of 0.1 to 70% by weight, and an alkali compound (C).
An aqueous solution containing 0.05 to 1% by weight , and
The component (A), the component (B) and the component (C) in the aqueous solution.
The total concentration of the components is 30 to 90% by weight.
The color filter glass release agent, and the color filter glass, wherein the color filter layer release agent is brought into contact with the defective substrate of the color filter to release the color filter layer from the color filter glass substrate. The present invention relates to a method for recycling a substrate.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION As the alkane diol (A) having 2 to 8 carbon atoms, ethylene glycol, propylene glycol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 1, Examples include 5-pentanediol, hexylene glycol, 1,6-hexanediol, 1,3-octylene glycol and the like. These alkane diols (C) having 2 to 8 carbon atoms can be used alone or in combination of two or more.
If the alkanediol has more than 8 carbon atoms, the solubility in water is low and the releasability is low, which is not preferable.

Further, in the present invention, an alkali compound
Considering the excellent stability and peelability for (C),
The amphoteric surfactant (B) is essential. Both sexes
As the surface active agent (B), sodium laurylaminoacetate is used.
Mu, sodium stearylaminoacetate, laurylamino
Sodium propionate, stearylaminopropion
Amino acid type amphoteric surfactants such as sodium acid lauryl
Dimethyl betaine, stearyl dimethyl betaine, lau
Rildihydroxyethyl betaine, stearyl dihydro
Xyethyl betaine, lauryl carboxymethyl hydro
Xyethyl imidazolinium betaine, stearyl cal
Boxymethyl hydroxyethyl imidazolinium betay
Examples include betaine-type amphoteric surfactants such as amines. This
These amphoteric surfactants (B) are used alone or in combination with 2
One or more species can be used in combination. In the present invention,
Is a nonionic as long as it does not reduce the effect of the invention.
Surfactant, anionic surfactant, cationic interface
The activator can be used in combination with the amphoteric surfactant (B) as appropriate.
It

Specific examples of the above nonionic surfactants include polyalkylene glycol ether type nonionics such as polyoxyalkylene alkyl (alkyl group having 6 or more carbon atoms) ether, polyoxyalkylene phenol ether, polyoxyalkylene alkylphenol ether and the like. Surfactants; polyalkylene glycol ester type nonionic surfactants such as polyalkylene glycol monoesters and polyalkylene glycol diesters; alkylene oxide adducts of fatty acid amides; polyhydric alcohol type nonions such as sorbitan fatty acid esters and sucrose fatty acid esters. Examples thereof include fatty acid alkanolamides and polyoxyalkylene alkylamines. The polyoxyalkylene refers to polyoxyethylene, polyoxypropylene, polyoxybutylene, or a copolymer of these.

As the anionic surfactant, various known sulfuric acid ester type anionic surfactants such as sulfuric acid ester salts of higher alcohols, alkyl sulfuric acid ester salts, polyoxyethylene alkyl sulfuric acid ester salts, etc .; alkyl sulfonates, alkyl benzenes. Various known sulfonate-based anionic surfactants such as sulfonates; phosphate-based anionic surfactants such as alkyl phosphate ester salts, polyoxyethylene alkyl phosphate ester salts, and polyoxyethylene alkylphenyl phosphate ester salts Examples include surfactants.

Examples of the cationic surfactant include alkylated ammonium salt type or quaternary ammonium salts such as amino acid octyltrimethylammonium chloride, cetyltrimethylammonium chloride, lauryltrimethylammonium chloride, lauryldimethylbenzylammonium chloride and stearyltrimethylammonium chloride. Examples thereof include cationic surfactants and cationic surfactants such as polyoxyalkylene amine.

[0013]

The alkali compound (C) is not particularly limited, but for example, alkali metal hydroxides such as sodium hydroxide and potassium hydroxide can be used.

The release agent for color filter layers of the present invention is an aqueous solution containing the alkanediol (A) having 2 to 8 carbon atoms, the amphoteric surfactant (B) and the alkali compound (C), and each component. Is component (A) 20 in an aqueous solution
˜80 wt%, (B) component 0.1 to 70 wt%, and (C) component 0.05 to 1 wt%. (A)
The content of the components is within the range in which the releasability can be sufficiently exhibited, and from this viewpoint, it is more preferable that the lower limit is 40% by weight and the upper limit is 70% by weight.
The content of the component (B) also indicates a range in which peelability can be sufficiently exhibited. If the content of the component (B) becomes too large, the content of other components such as the component (A) becomes relatively small and the releasability tends to decrease (B).
The upper limit of the content of the component is more preferably 10% by weight. Further, the lower limit of the component (C) takes into consideration that the upper limit has no effect on the glass substrate so that the releasability can be sufficiently exhibited. From these viewpoints, the lower limit of the content of the component (C) is set. Is 0.1% by weight, and the upper limit is 0.1.
5% by weight is more preferred.

If desired, the color filter layer release agent of the present invention may contain additives such as antifoaming agents and antioxidants.

The color filter layer release agent of the present invention is prepared in an aqueous solution such that the total concentration of the above-mentioned components (A), (B) and (C) is about 30 to 90% by weight. Is preferred. This total concentration shows the range in which the releasability can be sufficiently exhibited, and the lower limit is 40.
%, And the upper limit is more preferably 80% by weight.

In the present invention, the color filter glass substrate is regenerated by bringing the defective substrate of the color filter into contact with the color filter layer release agent to release the color filter layer from the color filter glass substrate. The method of contacting the color filter layer release agent is not particularly limited, and examples thereof include a method of immersing a defective substrate of the color filter in the color filter layer release agent. The defective substrate of the color filter can be housed in a predetermined cassette or the like and contacted, or can be swung together with the contact. The contact temperature with the color filter layer release agent is usually about 20 to 90 ° C., and the contact time is usually several minutes to 60 minutes. After peeling the color filter layer from the color filter glass substrate, the color filter glass substrate is taken out of the release agent, thoroughly washed with water, and then drained.

[0019]

According to the present invention, a defective substrate of a color filter can be prevented from invading other materials such as a glass substrate.
The color filter layer can be efficiently peeled off. The recycled glass substrate for a color filter can be used again for the color filter production, which contributes to the cost reduction of the color filter production.

[0020]

The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. The parts in each example are based on weight.

Example 1 40 parts of hexylene glycol, a lauryl betaine-type amphoteric surfactant (manufactured by Kao Corporation, trade name "Amphitol 20")
BS ") 0.5 part, potassium hydroxide 0.1 part and water 5
A release agent of the present invention was prepared by mixing 9.4 parts.

Examples 2 to 6 and Comparative Examples 1 to 5 In the same manner as in Example 1 except that the composition ratio of the release agent or the release agent component was changed as shown in Table 1, respectively. Was prepared.

[0023]

[Table 1]

Component (B) in Table 1 (surfactant)
Is as follows. (B1): Lauryl betaine type amphoteric surfactant (manufactured by Kao Corporation, trade name "Amphitol 20")
BS "), (B2): Alkyl betaine type amphoteric surfactant (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd., trade name" Amogen K "), (B-3): Imidazolinium betaine type amphoteric surfactant (Japan Yushi Co., Ltd., trade name "Nissan Anon GLM-R").

(Reproduction of Color Filter Glass Substrate) A color filter for a liquid crystal display was immersed in the release agent prepared in the above-mentioned Examples or Comparative Examples at 70 ° C. for 30 minutes to form a color filter layer from the color filter glass substrate. After peeling, the plate was washed with water and dried to collect the glass substrate for the color filter. The following evaluations were performed on the recovered glass substrate for a color filter. The evaluation results are shown in Table 2.

(1) Peelability The degree of peeling of the color filter layer of the glass substrate for a color filter was measured with a microscope (about 50 times) based on the following criteria.
It was visually determined by. ◯: Can be peeled off satisfactorily Δ: Slightly remains ×: Remains considerably

(2) State of Glass Substrate The degree of etching of the glass portion of the glass substrate for a color filter was measured using a surface roughness meter (manufactured by Tokyo Seimitsu Co., Ltd.) and evaluated according to the following criteria. ◯: Glass etching amount is less than 10 angstroms Δ: Glass etching amount is 10 to 100 angstroms x: Glass etching amount is more than 100 angstroms

[0028]

[Table 2]

─────────────────────────────────────────────────── ─── Continuation of front page (56) Reference JP-A-7-230081 (JP, A) JP-A-8-234153 (JP, A) JP-A-6-289218 (JP, A) JP-A-63- 221179 (JP, A) JP-A-6-299112 (JP, A) JP-A-57-76065 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) C09D 9/00-9 / 04 G02B 5/20

Claims (3)

(57) [Claims] 1. An alkanediol (A) having 2 to 8 carbon atoms.
20-80% by weight , amphoteric surfactant (B) 0.1-70
Wt% and alkaline compound (C) 0.05 to 1 wt%
An aqueous solution containing , and
The total concentration of the (A) component, (B) component and (C) component is
30-90% by weight of a color filter layer release agent. 2. An alkanediol (A) having 2 to 8 carbon atoms.
40 to 70% by weight, amphoteric surfactant (B) 0.1 to 10
% By weight and 0.1 to 0.5 weight of alkaline compound (C)
% In an aqueous solution, and
The total concentration of the (A) component, (B) component and (C) component is
The release agent for a color filter layer according to claim 1, which is 40 to 80% by weight . 3. The defective substrate of the color filter according to claim 1.
Alternatively, the method for remanufacturing a glass substrate for a color filter, which comprises contacting the release agent for a color filter layer according to 2 to peel the color filter layer from the glass substrate for a color filter.