KR102771028B1 - Stripping composition for color filter and removing method using the same - Google Patents

Abstract

The present invention relates to a stripping agent composition for a color filter and a stripping method using the same. According to the present invention, the time required for removing color resist is shortened while minimizing corrosion of a substrate when removing color resist, and since the color resist on a substrate can be removed in a relatively low-temperature process, the process is easy and the productivity of reuse of color filters can be improved.

Description

Stripping composition for color filter and method using the same {STRIPPING COMPOSITION FOR COLOR FILTER AND REMOVING METHOD USING THE SAME}

The present invention relates to a stripping composition for a color filter and a method using the same.

As we enter the information age, the demand for displays that process and display large amounts of information is increasing. Accordingly, it is necessary to develop portable displays that are low-power, lightweight, thin, and high-quality, as well as maximize space utilization.

As an example of an attempt to make a display thinner, a method of forming a color filter layer of a liquid crystal display (LCD) directly from a photosensitive composition within a TFT structure can be cited. However, up to now, when a defect occurs in a color filter manufactured on a TFT structure, it has been almost impossible to repair it by removing only the portion with an incorrect pattern. Accordingly, most substrates on which a defective color filter is formed are immediately discarded without undergoing reworking such as repair.

Accordingly, there is an increasing demand for a composition having strong stripping performance for removing color resist. In addition, when a color filter is formed on a thin film transistor of a lower substrate rather than an upper substrate, damage may occur to the lower thin film transistor, especially to the electrode formed of a metal including Al, when removing the color resist. Therefore, improved stripping performance is also required.

In the past, inorganic stripping solutions and RIE (reactive ion etching) using plasma were used to remove color resist. However, in the case of the above-mentioned inorganic stripping solutions, since sulfuric acid, nitric acid, fuming sulfuric acid, a mixture of nitric acid and hydrogen peroxide, etc. are used by heating them at high temperatures, not only does it have a negative impact on the safety of workers, but also there is an inconvenience that great care must be taken when handling them due to an increased risk of fire caused by heating. This RIE method using plasma is specifically disclosed in Patent Documents 1 to 3. However, this RIE method using plasma has the problems that not only does it require high vacuum and high energy, but also the process conditions are difficult and it is difficult to use on large areas. In addition, it has the disadvantage of requiring expensive equipment. In this way, it is difficult to stably remove large areas of color resist with the conventional method for removing organic films such as color resist, and the safety of workers is a problem or it is not commercially advantageous.

US 5756239 A US 5059500 A EP 0119337 B1

The purpose of the present invention is to provide a stripping agent composition for a color filter capable of efficiently removing a color resist and an organic insulating film in a short period of time without causing damage to a substrate, and a stripping method using the same.

Specifically, the present invention aims to provide a stripping composition for a color filter having excellent stripping and rinsing power and excellent corrosion prevention ability, and a stripping method using the same.

In detail, the present invention aims to provide a stripping agent composition for a color filter, which can be performed under relatively low-temperature process conditions and minimize corrosion of a substrate, and a stripping method using the same.

In order to solve the above-described problem, the present invention provides a stripping composition for a color filter, comprising: an inorganic base; a metal salt selected from lithium salts and zinc salts; an amine compound selected from alkanol amines and polyamines; a cyclic alcohol compound; and water.

In a stripping composition for a color filter according to one embodiment of the present invention, the inorganic base may be sodium hydroxide, potassium hydroxide, or a combination thereof.

In the stripping composition for a color filter according to one embodiment of the present invention, the metal salt may be an inorganic acid salt, an organic acid salt, a hydroxide or a halide.

A stripping composition for a color filter according to one embodiment of the present invention may include, based on the total weight, 1 to 7 wt% of the inorganic base; 0.01 to 3 wt% of the metal salt; 5 to 35 wt% of the amine compound; 3 to 20 wt% of the cyclic alcohol compound; and the remainder of water.

In a stripping composition for a color filter according to one embodiment of the present invention, the cyclic alcohol compound may be at least one selected from compounds represented by the following chemical formulas 1 and 2.

[Chemical formula 1]

[Chemical formula 2]

[In the above chemical formulas 1 and 2,

R ₁ is hydrogen, hydroxy or (C1-C4)alkyl;

A is -NR-, -S- or -O-, wherein R is hydrogen or hydroxy(C1-C5)alkyl;

a, b and c are independently selected from integers from 0 to 5, and when a or b is an integer of 0, it means a direct bond, and when c is an integer of 0, it means the case where all of the remaining substituents are hydrogen;

d and e are independently integers of 0 or 1, provided that when d is an integer of 0, A is -NR-, R is hydroxy(C1-C5)alkyl, and when e is an integer of 0, it means a direct bond.]

In the stripper composition for a color filter according to one embodiment of the present invention, the cyclic alcohol compound may be one or more selected from the group consisting of aromatic cyclic alcohols selected from phenol, cresol, xylenol, catechol, resorcinol, hydroquinone, pyrogallol, benzenetriol, salicyl alcohol, benzyl alcohol, gasrhodigenin, phenethyl alcohol, and tyrosol; and alicyclic cyclic alcohols selected from the group consisting of tetrahydrofurfuryl alcohol, pyrrolidinemethanol, pyrrolidineethanol, piperidinemethanol, and piperidineethanol.

In a stripping composition for a color filter according to one embodiment of the present invention, the amine compound may be a mixture of the alkanol amine and the poly amine, and may be a mixture in which 0.1 to 5 parts by weight of the poly amine is mixed based on 1 part by weight of the alkanol amine.

A stripping composition for a color filter according to one embodiment of the present invention may further include an alkylene glycol alkyl ether compound.

A stripping composition for a color filter according to one embodiment of the present invention may further include a nonionic surfactant.

In addition, the present invention provides a stripping method including a step of stripping a cured color resist using the stripping composition for a color filter described above.

In addition, the present invention provides a method for recycling a thin film transistor array substrate by removing a cured color resist using the above-described stripping composition for a color filter.

According to the present invention, the color resist is removed by dissolving the color resist without lifting it off from the substrate, thereby effectively removing the color resist and minimizing damage to the substrate. In addition, since the peeling power and rinsing power are excellent, the productivity of reuse of the color filter can be improved.

According to the present invention, since it can be performed at a relatively low temperature process, precipitation due to volatilization of the stripping composition or occurrence of precipitation within the solution is not caused, thereby resolving clogging of pipes or filters during the process. In addition, since deterioration of stripping performance is prevented, an efficient stripping process can be performed, and since it does not cause an irritating odor due to decomposition, it enhances the safety of workers.

According to the present invention, it is effective not only for removing a cured RGB color resist pattern, but also for removing an organic insulating film formed of an acrylic resin having a higher degree of curing and higher chemical and thermal stability. In particular, it is useful for removing a color resist and a negative-type organic insulating film formed on a thin film transistor, and has the advantage of being able to perform a stripping process without damaging the underlying thin film transistor.

Figure 1 is an image of the surface of a TFT substrate observed through an optical microscope in a removal test of an organic insulating film and a color resist using a stripping agent composition for a color filter according to Example 1 of the present invention.
Figure 2 is an image of the surface of a TFT substrate observed through an optical microscope in a removal test of an organic insulating film and a color resist using a stripping agent composition for a color filter according to Comparative Example 1 of the present invention.
Figure 3 is an image of the surface and cross-section of a substrate observed through a scanning electron microscope (SEM) in a substrate damage confirmation test for a stripping agent composition for a color filter according to Comparative Example 1 of the present invention.

Hereinafter, with reference to the attached drawings, a stripping composition for a color filter according to the present invention and a method using the same will be described in detail. The drawings introduced below are provided as examples so that those skilled in the art can sufficiently convey the idea of the present invention. Therefore, the present invention is not limited to the drawings presented below and may be embodied in other forms, and the drawings presented below may be exaggerated in order to clarify the idea of the present invention.

Unless otherwise defined, technical and scientific terms used in this specification have the meaning commonly understood by a person of ordinary skill in the art to which this invention belongs, and descriptions of well-known functions and configurations that may unnecessarily obscure the gist of the present invention are omitted in the following description and accompanying drawings.

As used herein, the singular form may be intended to include the plural form as well, unless the context clearly indicates otherwise.

In addition, units used in this specification without special mention are based on weight, and for example, units of % or ratio mean weight% or weight ratio, and weight% means the weight% that one component of the entire composition occupies in the composition unless otherwise defined.

In addition, the numerical range used in this specification includes the lower limit and the upper limit and all values within that range, the increments logically derived from the shape and width of the defined range, all double-defined values, and all possible combinations of the upper and lower limits of the numerical range defined in different shapes. Unless otherwise specifically defined in the specification of the present invention, values outside the numerical range that may occur due to experimental error or rounding of values are also included in the defined numerical range.

Additionally, the term "includes" in this specification is an open description having an equivalent meaning to expressions such as "comprises," "contains," "has," or "characterized by," and does not exclude additional elements, materials, or processes not listed.

Additionally, the term "substantially free of" in this specification means that other elements, materials or processes not listed together with the specified elements, materials or processes are present or not present at all so as not to have an unacceptably significant effect on at least one basic and novel technical idea of the invention.

In order to solve the problems of the prior art for removing color resist, the present inventors have applied for a patent (KR 10-2018-0024368 A) regarding a stripping agent composition for color filters. According to the above patent, color resist can be removed without damaging the lower film of the substrate within a short period of time, but there was a limitation that it was difficult to achieve the effect of inhibiting corrosion of the substrate at the same time.

Accordingly, the inventors of the present invention have intensified their research on a stripping composition for a color filter that can effectively suppress corrosion of the substrate as well as the underlying film while minimizing the time required for stripping the color resist formed on the substrate. As a result, they have confirmed that a synergy effect can be imparted when one or more selected from a predetermined metal salt is combined, thereby proposing the present invention.

According to the present invention, it has the advantage of being effective in removing color resist, etc., not causing damage to metal wiring such as aluminum and copper during the removal process, and simultaneously suppressing corrosion of the metal wiring and the substrate. In addition, since it has excellent peeling power and rinsing power for color resist and organic insulating film, if a defect occurs in the color filter, the defective surface can be removed within a short period of time. Accordingly, it can provide the effect of improving process yield and reducing cost.

According to the present invention, the color resist can be effectively removed by dissolving rather than by lifting off, by being used for removing an RGB color resist pattern. In addition, since it has excellent solubility for a color resist and an organic insulating film, it can be used not only for a color resist formed on an upper substrate but also for a color resist formed on a lower substrate, and can be usefully used for not only a positive type but also a negative type organic insulating film. In addition, it effectively suppresses corrosion of metal wiring and a substrate at the same time. Therefore, according to the present invention, the productivity of reuse of color filters of various aspects can be improved.

In addition, in the present invention, ammonium-based organic bases such as alkyl ammonium hydroxide, which may decompose during a stripping process of color resist, etc., and cause precipitates in the chemical solution, are not preferred. In addition, when the ammonium-based organic base is used, the chemical solution is not stable, precipitates are generated, or the chemical solution decomposes to cause an irritating odor, which is detrimental to the safety of the process. Therefore, in the present invention, it is preferred that ammonium-based organic bases, etc. are substantially not included. This provides an advantage in that it does not cause problems such as changing the composition of the chemical solution by precipitating a metal existing in the chemical solution, and provides advantages in the process.

Hereinafter, the present invention will be described in detail.

To achieve the above-described effects, the present invention provides a stripping composition for a color filter, comprising: an inorganic base; a metal salt selected from lithium salts and zinc salts; an amine compound selected from alkanol amines and polyamines; a cyclic alcohol compound; and water.

The stripping agent composition for color filters of the present invention, which satisfies the above composition, has excellent penetration ability into polymer components constituting color resist or organic insulating films, and exhibits remarkable stripping power. In addition, since the change in the composition of the chemical solution is minimal, it does not volatilize and precipitate as a solid, or cause damage to the substrate or underlying film due to a change in the composition of the chemical solution.

That is, the stripper composition for color filters according to the present invention containing a metal salt of lithium, zinc or a combination thereof is noteworthy in that it can simultaneously satisfy the effects of removing color resist and inhibiting corrosion of the substrate without damaging the lower film of the substrate in a short period of time, which was a problem in the prior art. However, in terms of such effects, the present invention corresponds to a new discovery that was completely unexpected by those skilled in the art in that such effects were not confirmed when using a metal salt containing a metal of the same group as lithium or zinc.

For example, in the case of using metal salts containing alkali metals such as sodium and potassium that can belong to the same group as lithium, corrosion inhibition of both the substrate and the underlying film was not satisfied at the same time.

In a stripping composition for a color filter according to one embodiment of the present invention, the inorganic base may be sodium hydroxide, potassium hydroxide, or a combination thereof.

In the stripping composition for a color filter according to one embodiment of the present invention, the metal salt may be an inorganic acid salt, an organic acid salt, a hydroxide or a halide.

For example, the metal salt may be one or more selected from an inorganic acid salt, an organic acid salt, a hydroxide, a halide or a combination thereof of lithium; and an inorganic acid salt, an organic acid salt, a hydroxide, a halide or a combination thereof of zinc.

The above inorganic acid salt is not limited to a conventional salt, and may be a carbonate, phosphate, sulfate or nitrate of the above-mentioned metal.

The above organic acid salts are not limited as long as they are common ones, and may be acetate, benzoate, maleate, propionate, fumarate, isethionate, citrate, lactate, gluconate, succinate, oxalate, phenylacetate, methanesulfonate, toluenesulfonate, salicylate, benzenesulfonate, sulfanilate, aspartate, glutamate, stearate, palmitate, oleate, laurate, pantothenate, tannate, ascorbate, valerate, adipate, boronic acid, alginate, aspartate, camphorate, heptanoic acid or hexanoic acid of the above metals.

The above halide is not limited to a conventional one and may be a fluoride, chloride, bromide or iodide of the above-mentioned metal.

The above hydroxide may be lithium hydroxide or zinc hydroxide.

For example, the stripping composition for the color filter preferably includes at least one or two or more metal salts selected from inorganic acid salts selected from phosphates, sulfates, nitrates, etc.; organic acid salts selected from acetates, benzoates, etc.; chlorides; and hydroxides.

For example, when the stripping composition for the color filter contains at least one zinc salt, it may be desirable for the stability of the solution, but is not limited thereto.

For example, when the stripping composition for the color filter contains two different metal salts, they can be mixed and used in a weight ratio of 1:0.1 to 1:10.

A stripping composition for a color filter according to one embodiment of the present invention may include, based on the total weight, 1 to 7 wt% of the inorganic base; 0.01 to 3 wt% of the metal salt; 5 to 35 wt% of the amine compound; 3 to 20 wt% of the cyclic alcohol compound; and the remainder of water.

For example, the stripping composition for the color filter may include 2 to 7 wt% of the inorganic base; 0.05 to 2 wt% of the metal salt; 5 to 30 wt% of the amine compound; 5 to 20 wt% of the cyclic alcohol compound; and 40 to 80 wt% of water.

For example, the stripping composition for the color filter may include 3.5 to 6 wt% of the inorganic base; 0.1 to 1.0 wt% of the metal salt; 7 to 20 wt% of the amine compound; 8 to 20 wt% of the cyclic alcohol compound; and 45 to 75 wt% of water.

As described above, the stripping composition for color filters of the present invention can be used in combinations of various amounts. At this time, it was confirmed that when the cyclic alcohol compound is used in an amount greater than that of a conventional additive, that is, in excess of 5 wt%, it is more effective in the corrosion of the underlying thin film transistor, particularly the substrate formed of a metal including Al, when removing the color resist.

The above alcohol compound may be a compound represented by the following chemical formula 1 or chemical formula 2.

[Chemical formula 1]

[Chemical formula 2]

[In the above chemical formulas 1 and 2,

R ₁ is hydrogen, hydroxy or (C1-C4)alkyl;

A is -NR-, -S- or -O-, wherein R is hydrogen or hydroxy(C1-C5)alkyl;

a, b and c are independently selected from integers from 0 to 5, and when a or b is an integer of 0, it means a direct bond, and when c is an integer of 0, it means the case where all of the remaining substituents are hydrogen;

d and e are independently integers of 0 or 1, provided that when d is an integer of 0, A is -NR-, R is hydroxy(C1-C5)alkyl, and when e is an integer of 0, it means a direct bond.]

For example, it is preferable that the stripping composition for the color filter contain at least one alicyclic ring alcohol.

For example, the alicyclic ring alcohol may be at least one selected from compounds represented by the following chemical formulas 2-1 and 2-2.

[Chemical Formula 2-1]

[Chemical Formula 2-2]

[In the above chemical formula 2-1 and chemical formula 2-2,

A' is -S- or -O-;

b is independently selected from integers 0 to 5;

e is an integer 0 or 1, independently of each other.]

Non-limiting examples of the alcohol compound include one or more selected from: aromatic cyclic alcohols selected from phenol, cresol, xylenol, catechol, resorcinol, hydroquinone, pyrogallol, benzenetriol, salicyl alcohol, benzyl alcohol, gasrhodigenin, phenethyl alcohol, tyrosol, and furfuryl alcohol; and alicyclic cyclic alcohols selected from tetrahydrofurfuryl alcohol, pyrrolidinemethanol, pyrrolidineethanol, piperidinemethanol, and piperidineethanol.

For example, the alicyclic ring alcohol may be preferably selected from tetrahydrofurfuryl alcohol, 1-pyrrolidinemethanol, 2-pyrrolidinemethanol, 1-pyrrolidineethanol, 2-pyrrolidineethanol, 1-piperidinemethanol, 2-piperidinemethanol, 1-piperidineethanol, and 2-piperidineethanol.

In the stripper composition for a color filter according to one embodiment of the present invention, the amine compound plays a role of enhancing stripping power and rinsing power, and accelerates penetration and swelling into the polymer in the color resist. For such a synergy effect, it is preferable that the amine compound simultaneously includes an alkanol amine and a poly amine, and an embodiment in which the alkanol amine or the poly amine is used alone can also exhibit the effect desired in the present invention.

The above alkanol amine may contain an alkanol group having 1 to 10 carbon atoms.

Non-limiting examples of the above alkanol amines include monomethanolamine, monoethanolamine, N-methylethanolamine, N-ethylethanolamine, N-propylethanolamine, N-butylethanolamine, diethanolamine, triethanolamine, N-methyldiethanolamine, N-ethyldiethanolamine, isopropanolamine, diisopropanolamine, triisopropanolamine, N-methylisopropanolamine, N-ethylisopropanolamine, N-propylisopropanolamine, 2-aminopropan-1-ol, N-methyl-2-aminopropan-1-ol, N-ethyl-2-aminopropan-1-ol, 1-aminopropan-3-ol, N-methyl-1-aminopropan-3-ol, N-ethyl-1-aminopropan-3-ol, 1-aminobutan-2-ol, N-Methyl-1-aminobutan-2-ol, N-Ethyl-1-aminobutan-2-ol, 2-Aminobutan-1-ol, N-Methyl-2-aminobutan-1-ol, N-Ethyl-2-aminobutan-1-ol, 3-Aminobutan-1-ol, N-Methyl-3-aminobutan-1-ol, N-Ethyl-3-aminobutan-1-ol, 1-Aminobutan-4-ol, N-Methyl-1-aminobutan-4-ol, N-Ethyl-1-aminobutan-4-ol, 1-Amino-2-methylpropan-2-ol, 2-Amino-2-methylpropan-1-ol, 1-Aminopentan-4-ol, 2-Amino-4-methylpentan-1-ol, 2-Aminohexan-1-ol, 3-Aminoheptan-4-ol, 1-Aminooctan-2-ol, 5-Aminooctan-4-ol, It may be an aliphatic alkanolamine such as 1-aminopropane-2,3-diol, 2-aminopropane-1,3-diol, tris(oxymethyl)aminomethane, 1,2-diaminopropan-3-ol, 1,3-diaminopropan-2-ol, and 2-(2-aminoethoxy)ethanol.

For example, it is preferable that the alkanolamine contains a methanol group (HO-CH ₂ -*) or an ethanol group (HO-CH ₂ CH ₂ -*).

Non-limiting examples of the above polyamines include ethylenediamine, propylenediamine, butylenediamine, trimethylenediamine, tetramethylenediamine, 1,3-diaminobutane, 2,3-diaminobutane, pentamethylenediamine, 2,4-diaminopentane, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, nonamethylenediamine, N-methylethylenediamine, N,N-dimethylethylenediamine, trimethylethylenediamine, N-ethylethylenediamine, N,N-diethylethylenediamine, triethylethylenediamine, 1,2,3-triaminopropane, tris(2-aminoethyl)amine, tetra(aminomethyl)methane, diethylenetriamine, triethylenetetramine, tetraethylenepentaamine, heptaethyleneoctaamine, and nonaethylenedecaamine.

For example, it is preferred that the polyamine contain at least three amino groups.

For example, the polyamine is preferably one or more selected from diethylenetriamine, triethylenetetramine, tetraethylenepentaamine, heptaethyleneoctaamine, and nonaethylenedecaamine.

As described above, the amine compound may be a mixture of the alkanol amine and the polyamine. In this case, the mixture may be a mixture in which 0.1 to 5 parts by weight of the polyamine is mixed based on 1 part by weight of the alkanol amine.

For example, the amine compound may be a mixture of an alkanol amine (A) and a polyamine (B), mixed at a weight ratio (A:B) of 1:0.1 to 1:3.

For example, the amine compound may be a mixture of an alkanol amine (A) and a polyamine (B), mixed at a weight ratio (A:B) of 1:0.3 to 1:2.

The stripping agent composition for a color filter according to one embodiment of the present invention may further include an alkylene glycol alkyl ether compound in order to improve the solubility of the color resist and increase the stability of the solution. In addition, since it is effective in removing uncured color resist, it may be useful in a cleaning step after a developing process, a step of removing an organic insulating film used for coating a color filter, etc.

The above alkylene glycol alkyl ether compound is not limited as long as it is a conventional one, and it is preferable if it contains an ether group and a hydroxyl group in the molecule to reduce surface tension and can be mixed with water.

The above alkylene glycol alkyl ether compound may be selected from monoalkylene glycol monoalkyl ether, dialkylene glycol monoalkyl ether, and trialkylene glycol monoalkyl ether. The alkylene or alkyl may have 1 to 4 carbon atoms.

For example, the alkylene glycol alkyl ether compound is selected from the group consisting of ethylene glycol monomethyl ether, diethylene glycol monomethyl ether, triethylene glycol monomethyl ether, propylene glycol monomethyl ether, dipropylene glycol monomethyl ether, tripropyl glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol monoethyl ether, triethylene glycol monoethyl ether, propylene glycol monoethyl ether, dipropylene glycol monoethyl ether, tripropyl glycol monoethyl ether, ethylene glycol monopropyl ether, diethylene glycol monopropyl ether, triethylene glycol monopropyl ether, propylene glycol monopropyl ether, dipropylene glycol monopropyl ether, tripropyl glycol monopropyl ether, ethylene glycol monobutyl ether, diethylene glycol monobutyl ether, triethylene glycol monobutyl ether, propylene glycol monobutyl ether, dipropylene glycol monobutyl ether, and tripropyl glycol monobutyl ether; And ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, propylene glycol dimethyl ether, dipropylene glycol dimethyl ether, tripropyl glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol diethyl ether, triethylene glycol diethyl ether, propylene glycol diethyl ether, dipropylene glycol diethyl ether, tripropyl glycol diethyl ether, ethylene glycol dipropyl ether, diethylene glycol dipropyl ether, triethylene glycol dipropyl ether, propylene glycol dipropyl ether, dipropylene glycol dipropyl ether, tripropyl glycol dipropyl ether, ethylene glycol dibutyl ether, diethylene glycol dibutyl ether, triethylene glycol dibutyl ether, propylene glycol dibutyl ether, dipropylene glycol dibutyl ether, and tripropyl glycol dibutyl ether; one or more selected from the above.

In addition, the alkylene glycol alkyl ether compound may be included in an amount of 3 to 30 wt%, specifically 3 to 25 wt%, and more specifically 5 to 20 wt%, based on the total weight of the composition.

The stripping composition for a color filter according to one embodiment of the present invention may further include a nonionic surfactant. The nonionic surfactant can be used to increase wettability for a hydrophobic interlayer organic insulating film, thereby preventing surface stains on a substrate or the like after color resist removal.

The above nonionic surfactant is not limited as long as it is a conventional one, and may be selected from polyoxyethylene alkyl ether type, polyoxyethylene alkylphenyl ether type, polyoxyethylene polyoxypropylene alkyl ether type, polyoxyethylene polyoxybutylene alkyl ether type, polyoxyethylene alkylamino ether type, polyoxyethylene alkylamido ether type, polyethylene glycol fatty acid ester type, sorbitan fatty acid ester type, polyoxyethylene sorbitan fatty acid ester type, glycerin fatty acid ester type, alkyrolamide type, and glycerin ester type.

Additionally, the nonionic surfactant may be included in an amount of 0.01 to 5 wt% based on the total weight of the composition.

In addition, in the stripping composition for a color filter according to one embodiment of the present invention, it may also be an aspect of the present invention to further include an ammonium-based organic base such as alkyl ammonium hydroxide. In this case, the amount of additive may be added to the inorganic base in order to secure stability in the liquid.

As described above, the stripping composition for a color filter according to the present invention can be used to remove a cured RGB color resist pattern of a color filter of a liquid crystal display device, and can effectively remove the color resist in a short period of time, and can protect not only metal wiring but also a substrate, thereby dramatically suppressing corrosion or damage thereof. In addition, since it has excellent stripping and rinsing powers for an organic insulating film, it can be effective in removing them simultaneously. That is, according to the present invention, damage to a substrate caused by a strongly alkaline stripping composition for a color filter is reduced, and when a defect occurs in a color filter, the defective surface can be removed in a short period of time.

Therefore, according to the present invention, a TFT array substrate can be efficiently recycled from a defective substrate, thereby providing the effects of improved process yield and cost reduction.

The present invention may include a step of stripping a cured color resist using the above-described stripping composition for a color filter.

The above-described stripping step may be a step of removing the color resist, i.e., the cured color resist, formed on the substrate by a dipping method or a spraying method using the above-described stripping composition for color filters.

In addition, the present invention provides a method for recycling a thin film transistor array substrate, including such a peeling step. At this time, the thin film transistor array substrate may be a discarded one after use and may include a color filter formed in a defective manner.

That is, the present invention can provide a method for recycling a defective substrate by removing the color resist of the defective substrate generated in the color filter process, and particularly, in the case of a color filter including an organic insulating film such as an acrylic resin or a novolak phenol resin having a high degree of curing, the color resist can be satisfactorily removed at a high removal speed.

For example, a step of removing a hardened color resist may use a dipping method, a spraying method, etc. At this time, the temperature at which the dipping or spraying is performed is not particularly limited, and may be performed at 15 to 100°C, and specifically, may be performed at 40 to 80°C. In addition, the performing time may be 30 seconds to 40 minutes, and specifically, 1 minute to 20 minutes. In this specification, a step of removing a color resist is judged to have been successfully completed when the performing time is within 10 minutes.

Hereinafter, the stripping composition for color filters and the stripping method using the same according to the present invention will be described in more detail through examples. However, the following examples are only a reference for describing the present invention in detail, and the present invention is not limited thereto, and may be implemented in various forms. In addition, unless otherwise defined, all technical terms and scientific terms have the same meaning as generally understood by one of ordinary skill in the art to which the present invention belongs. In addition, the terminology used in the description of the present invention is only for the purpose of effectively describing specific examples, and is not intended to limit the present invention.

(Evaluation method)

1. Removal test of organic insulating film and color resist

Using the stripping agent composition for color filters manufactured from the following examples and comparative examples, a removal test of an organic insulating film and a color resist was conducted.

Specifically, a TFT substrate (Glass, 5 cm × 5 cm) on which a color resist photosensitive agent including an acrylic film, which is an organic insulating film, was generated was used as a test piece. The test piece was immersed in a stripper composition for each color filter at 75°C, and the time (min) required from the beginning of immersion until the organic insulating film and the color resist were completely stripped from the substrate was observed using an optical microscope, and the results are shown in Table 3 and Figures 1 and 2 below.

In a removal test of an organic insulating film and a color resist, a preferable value of the time required for completion of their removal may be 12 minutes or less, and a more preferable value may be 10 minutes or less.

2. Test for damage to substrate (Glass)

The degree of damage to a substrate (glass) was quantitatively evaluated using the stripping agent composition for a color filter manufactured from the following examples and comparative examples.

Specifically, specimens having Poly ITO Patterned on Glass were used. Each specimen was immersed in a stripping solution composition for color filters manufactured from Examples or Comparative Examples for 60 minutes, then washed with ultrapure water for 30 seconds and dried with nitrogen for 10 seconds. The surface and cross-section of each dried specimen were observed in detail using an optical microscope and a scanning electron microscope (SEM). In order to quantitatively determine the degree of glass corrosion of each specimen, the size (nm) of the corroded portion was measured, and the results are shown in Table 3 and Fig. 3 below.

In a substrate damage verification test, a desirable evaluation value may be glass corrosion of 30 nm or less, and a more desirable value may be glass corrosion of 25 nm or less.

3. Test for damage to the substrate (lower layer)

The degree of damage to the substrate (substrate) was quantitatively evaluated using the stripping agent composition for color filters manufactured from the following examples and comparative examples.

Specifically, the specimens used in the removal test of the organic insulating film and the color resist, i.e., the specimens from which the organic insulating film and the color resist were removed, were used. The degree of substrate damage was tested under harsh environmental conditions by re-immersing each specimen in a new stripper composition for color filters having the same composition. At this time, each specimen was re-immersed in the stripper composition for color filters prepared from the examples or comparative examples for 60 minutes, and then washed with ultrapure water for 30 seconds and dried with nitrogen for 10 seconds. Each dried specimen was turned over to closely observe the lower film. In order to quantitatively determine the degree of corrosion of the lower film of each specimen, the number of lower film corrosions was quantified within a range of 1x1 cm, and the results are shown in Table 3 and Fig. 1 below.

(Examples 1 to 15)

A stripping composition (100 g) for a color filter was prepared by mixing each component in the amounts described in Table 1 below.

(Table 1)

(Comparative examples 1 to 12)

A stripping composition (100 g) for a color filter was prepared by mixing each component in the contents described in Table 2 below.

(Table 2)

(Table 3)

When examining the effect according to the presence or absence of the metal salt mentioned in Table 3 above, in all cases of Examples 1 to 15, the time for completing the removal of the organic insulating film and the color resist was confirmed to be within 10 minutes, showing good results in the removal test of the organic insulating film and the color resist. In addition, the corrosion size of the glass was confirmed to be 25 nm or less, and no defects in the lower film were confirmed at all.

On the other hand, in the case of Comparative Examples 1 and 6 that do not include the aforementioned metal salt, the time required to complete the removal of the organic insulating film and the color resist exceeded 10 minutes, and the size of the glass corrosion was also significant. In particular, the number of defects in the lower film significantly increased. In addition, in the case of Comparative Examples 11 and 12 that include a potassium salt, they were also not effective in inhibiting corrosion of the glass and the lower film.

When tetramethylammonium hydroxide, an organic base, was used, an irritating odor was generated due to decomposition of the organic base during the stripping process. In addition, in the removal test of the organic insulating film and the color resist, low stripping power was observed. Accordingly, the time required to complete the removal of the organic insulating film and the color resist was not good.

When examining the effect according to the presence or absence of the alkylene glycol alkyl ether compound in Table 3 above, it was confirmed that a faster organic insulating film and color resist removal completion time could be satisfied. This can be said to be because the alkylene glycol alkyl ether compound increases the wettability for the organic insulating film and color resist, thereby improving the removal performance.

As illustrated in the following Figure 1, when a stripping process is performed using the stripping composition for a color filter according to the present invention, it was confirmed that not only the color resist but also the acrylic film, which is an organic insulating film, can be sufficiently removed in a short period of time, and almost no damage occurs to the surface and cross-section of the substrate. On the other hand, as illustrated in the following Figure 2, in the case of Comparative Example 1, a large number of lower film defects were found. In addition, as illustrated in the following Figure 3, in the case of Comparative Example 1, glass corrosion was very significant.

In summary, it was confirmed that the stripping agent composition for color filters of the present invention can significantly improve the productivity of reuse of color filters because it has excellent stripping power of color resist and remarkable corrosion inhibition properties of glass and lower films. In addition, it can be usefully used for removing organic insulating films used for coating color filters because it has excellent stripping power of color resist as well as rinsing power for uncured residual color resist that may occur during the developing process.

As described above, the present invention has been described by specific matters and limited examples and comparative examples, but these have been provided only to help a more general understanding of the present invention, and the present invention is not limited to the above examples, and those skilled in the art to which the present invention pertains can make various modifications and variations from this description.

Therefore, the idea of the present invention should not be limited to the described embodiments, and all things that are equivalent or equivalent to the claims described below as well as the claims are included in the scope of the idea of the present invention.

Claims (12)

inorganic base;
Metal salts selected from lithium salts and zinc salts;
An amine compound selected from alkanol amines and polyamines;
Cyclic alcohol compounds; and
Containing water;
The above inorganic base is sodium hydroxide, potassium hydroxide or a combination thereof,
A stripping composition for a color filter, wherein the metal salt is one or more selected from an inorganic acid salt, an organic acid salt, or a combination thereof of lithium; and an inorganic acid salt, an organic acid salt, a hydroxide, or a combination thereof of zinc. delete delete In paragraph 1,
Based on total weight,
1 to 7 wt% of the above inorganic base;
0.01 to 3 wt% of the above metal salt;
5 to 35 wt% of the above amine compound;
3 to 20 wt% of the above cyclic alcohol compound; and
A stripping composition for a color filter, comprising a residual amount of water. In paragraph 1,
The above cyclic alcohol compound is,
A stripping agent composition for a color filter, wherein at least one compound is selected from compounds represented by the following chemical formulas 1 and 2:
[Chemical formula 1]

[Chemical formula 2]

In the above chemical formulas 1 and 2,
R ₁ is hydrogen, hydroxy or (C1-C4)alkyl;
A is -NR-, -S- or -O-, wherein R is hydrogen or hydroxy(C1-C5)alkyl;
a, b and c are independently selected from integers from 0 to 5, and when a or b is an integer of 0, it means a direct bond, and when c is an integer of 0, it means the case where all of the remaining substituents are hydrogen;
d and e are independently integers of 0 or 1, provided that when d is an integer of 0, A is -NR-, R is hydroxy(C1-C5)alkyl, and when e is an integer of 0, it means a direct bond. In paragraph 1,
The above cyclic alcohol compound is,
An aromatic cyclic alcohol selected from phenol, cresol, xylenol, catechol, resorcinol, hydroquinone, pyrogallol, benzenetriol, salicyl alcohol, benzyl alcohol, gasrhodigenin, phenethyl alcohol and tyrosol; and
A stripping composition for a color filter, comprising one or more cyclic alcohols selected from tetrahydrofurfuryl alcohol, pyrrolidine methanol, pyrrolidine ethanol, piperidine methanol and piperidine ethanol. In paragraph 1,
The above amine compound is,
A stripping composition for a color filter, which is a mixture of the above alkanol amine and the above poly amine. In Article 7,
The above mixture is,
Based on 1 part by weight of the above alkanol amine,
A stripping agent composition for a color filter, which is a mixture containing 0.1 to 5 parts by weight of the above polyamine. In paragraph 1,
A stripping composition for a color filter, further comprising an alkylene glycol alkyl ether compound. In paragraph 1,
A stripping composition for a color filter, further comprising a nonionic surfactant. A stripping method comprising a step of stripping a cured color resist using a stripping composition for a color filter according to claim 1. A method for recycling a thin film transistor array substrate by removing a cured color resist using a stripping composition for a color filter according to claim 1.