KR101520098B1 - Aqueous detergent composition - Google Patents

Abstract

The present invention relates to an aqueous cleaning composition composition not containing an alkaline compound, which comprises 0.1 to 15% by weight of C1 to C5 lower alcohols, 0.1 to 15% by weight of a water-soluble glycol ether compound, Based cleaning liquid composition.

A water system, a cleaning agent, an orientation film, a polyimide,

Description

Aqueous detergent composition < RTI ID = 0.0 >

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to an aqueous cleaning liquid composition used for semiconductors, display devices and the like. More particularly, the present invention relates to an aqueous cleaning composition for a substrate used before and after rubbing of a liquid crystal alignment film in a liquid crystal cell manufacturing process of a liquid crystal display.

Generally, in a process of manufacturing a liquid crystal cell, a polyimide is applied to two pattern substrates having an electrode pattern formed thereon so as to have the function of an alignment film and an insulation film, and an alignment film is formed by rubbing the alignment film in a predetermined direction. Thereafter, a spacer is disposed to form a container of the liquid crystal cell and to control the thickness of the seal adhesive and the liquid crystal cell, and the two substrates are bonded. At this time, if residual contaminants are present on the alignment film substrate onto which the liquid crystal is injected, it is difficult to obtain a clear display screen and also cause defects in packaging, so it is necessary to clean and remove contaminants remaining on the substrate.

The contamination path of the substrate during the manufacture of the liquid crystal cell of the liquid crystal display is a foreign material or polyimide particles which are separated from the rubbing cloth in the rubbing process before bonding the two PI substrates and they adhere to the substrate and cause defects .

Conventionally, a solvent such as an isopropanol or isopropanol aqueous solution or pure water was used in order to remove such contaminants generated during the process. However, cleaning with a solvent causes a problem of residual solvent on the substrate, leading to defects, chemical stability such as safety to the environment and flammability, and problems with the manufacturing process cost due to the rise in raw material prices . In addition, pure water does not exhibit sufficient cleaning power against contaminants, which leads to a decrease in production yield.

Further, in the case of a cleaning agent containing an alkaline compound, it causes a problem of damaging the PI alignment film.

Japanese Patent Application Laid-Open No. 3-62018 proposes a method of stably forming a high pretilt angle by ultrasonically cleaning the rubbing substrate with pure water. However, it is not easy to introduce ultrasonic waves into the display manufacturing process, and the cleaning method using pure water does not satisfy the property of the cleaning agent which is recently required.

Japanese Patent Application Laid-Open No. 3-81730 proposes a method of cleaning the surface of a rubbing substrate using a brush, but a cleaning effect can not be expected due to re-adhesion of secondary contaminants and contaminants generated from the brush to the substrate.

The above-described techniques are characterized by the use of a device that provides physical cleaning power to the cleaning process, which not only increases the cost of the cleaning process, but also increases the solvent residue, rinse defect, It is not free from problems such as re-adhesion of particles.

In this field, in order to solve the above-mentioned problems, various water-based cleaning systems having excellent safety for human body and work safety and having excellent detergency and rinsing ability by adding various surfactants have been studied .

The present invention has been made to solve the above problems of the prior art, and it is an object of the present invention to provide a liquid crystal display device which is excellent in wetting and penetration effect and not only has excellent cleaning effect against contaminants present on an alignment film substrate but also does not cause damage to an alignment film, Which is safe, environmentally friendly, and low-foaming.

The present invention relates to an aqueous cleaning composition composition not containing an alkaline compound, which comprises 0.1 to 15% by weight of C1 to C5 lower alcohols, 0.1 to 15% by weight of a water-soluble glycol ether compound, Based cleaning liquid composition.

The present invention also provides a liquid crystal cell including an alignment film cleaned with the aqueous cleaning composition and a liquid crystal display device including the liquid crystal cell.

The water-based cleaning liquid composition of the present invention has excellent wetting and penetration effect and is excellent in cleaning effect against contaminants present on an alignment film substrate. In addition, it does not cause damage to the alignment film, is not flammable, is safe and environmentally friendly, It is very advantageous in cleaning the substrate before and after the rubbing of the liquid crystal alignment film in the liquid crystal cell manufacturing process of the liquid crystal display.

The present invention relates to an aqueous cleaning composition composition not containing an alkaline compound, which comprises 0.1 to 15% by weight of C1 to C5 lower alcohols, 0.1 to 15% by weight of a water-soluble glycol ether compound, Based cleaning liquid composition.

The aqueous cleaning composition composition may be useful for cleaning substrates before and after a rubbing process of a liquid crystal alignment film during a liquid crystal cell manufacturing process of a display. In particular, the aqueous cleaning composition may be useful for cleaning polyimide alignment layers.

Alkali compounds have the ability to remove contaminants and organic substances from the atmosphere and are used in general cleaning agents. However, if they contain a small amount of alkali compounds, they may cause damage to the PI (polyimide) alignment layer. Therefore, the cleaning liquid composition of the present invention does not contain such an alkaline compound.

In the aqueous cleaning composition of the present invention, the C1 to C5 lower alcohols increase the wetting and penetrating ability of the cleaning liquid to the substrate, and improve the ability to prevent reattachment of contaminants so that contaminants can be easily removed from the substrate. Of the C1 to C5 lower alcohols, C1 to C4 lower alcohols are preferable considering water solubility. Specific examples of C1 to C4 lower alcohols include methanol, ethanol, n-propanol, isopropanol, ethylene glycol, 1,2- Propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, glycerol and 1,2,4-butanetriol. They may be used alone or in combination of two or more.

The content of the lower alcohol is preferably 0.1 to 15% by weight based on the total weight of the composition. If the content is less than 0.1% by weight, the surface tension can not be lowered and the wetting penetration can not be expected. If the content is more than 15% by weight, the solvent may remain on the substrate.

In the aqueous cleaning composition of the present invention, the water-soluble glycol ether compound serves to remove the oil component on the surface of the rubbing substrate, which is difficult to remove only with a low alcohol aqueous solution, and to improve the dissolving power to water. Among the water-soluble glycol ether compounds, C1-C10 water-soluble glycol ethers are preferably used. Representative examples thereof include ethylene glycol monomethyl ether (MG), diethylene glycol monomethyl ether (MDG), triethylene glycol monomethyl ether ), Polyethylene glycol monomethyl ether (MPG), ethylene glycol monoethyl ether (EG), diethylene glycol monoethyl ether (EDG), ethylene glycol monobutyl ether (BG), diethylene glycol monobutyl ether (BDG) Ethylene glycol monobutyl ether (BTG), propylene glycol monomethyl ether (MFG), dipropylene glycol monomethyl ether (MFDG), etc. These may be used singly or in combination of two or more.

If the content of the glycol ether is less than 0.1% by weight, it is difficult to remove the oil component on the surface of the rubbing substrate. When the content of the glycol ether is more than 15% by weight, Lt; RTI ID = 0.0 > wettability < / RTI >

Water contained in the aqueous cleaning composition of the present invention is not particularly limited, but it is preferable to use deionized water having a specific resistance value of 18 M? / Cm or more as water for semiconductor processing. The water content can be adjusted according to the content of the other constituents.

The aqueous cleaning composition of the present invention may further include conventional additives known in the art to improve cleaning performance.

The components contained in the aqueous cleaning composition of the present invention can be prepared by a generally known method, and particularly preferably have a purity for semiconductor processing.

The present invention also relates to a liquid crystal cell including an alignment film cleaned with the above-described aqueous cleaning composition and a liquid crystal display device including the liquid crystal cell. When the aqueous detergent composition of the present invention is used, since the residual contaminants present on the alignment film substrate are completely removed, the liquid crystal cell including such an alignment film has excellent quality. Further, a liquid crystal display device including such a liquid crystal cell can provide a clear display screen.

The cleaning method using the aqueous cleaning composition of the present invention is not particularly limited, and the immersion cleaning method, the oscillating cleaning method, the ultrasonic cleaning method, the shower spray cleaning method, the puddle cleaning method, and the brush cleaning method can be applied.

The cleaning liquid of the present invention is a cleaning agent for a substrate before and after rubbing of a liquid crystal alignment film in the process of manufacturing a liquid crystal cell of a liquid crystal display. The cleaning liquid is excellent not only in long-term stability against cleaning performance, The material can be sufficiently removed. In addition, there is no cleaning liquid residue, no contamination such as particles adheres on the substrate, and there is no problem of damage to the surface of the alignment film. Therefore, a safe cleaning system can be provided.

In addition, since the aqueous cleaning composition of the present invention has a low foaming property, problems such as lowering of workability due to bubbles that may occur in a process such as spraying do not occur.

Hereinafter, the present invention will be described in detail through examples and the like. However, the following examples are provided to further illustrate the present invention, and the scope of the present invention is not limited thereto.

Examples 1 to 4 and Comparative Examples 1 to 3: Preparation of cleaning liquid composition

The ingredients listed in Table 1 were added to a mixing vessel equipped with a stirrer and stirred at a speed of 500 rpm for 1 hour at room temperature to prepare a cleaning liquid composition.

Test example: Evaluation of detergency and alignment film damage

1. Evaluation of cleaning power

100 ml of the cleaning liquid composition prepared in Examples 1 to 4 and Comparative Examples 1 to 3 was placed in a 250 ml capacity beaker and ultrasonic waves were applied for 1 minute immediately after carrying the substrate (5 x 5 x 0.7 cm) rubbed with the polyimide alignment film (40 kHz, 20 캜). After the substrate was cleaned for a predetermined time, the substrate was taken out and rinsed by rinsing with ultrapure water for 30 seconds. The liquid on the substrate surface was removed with nitrogen gas and then dried in an oven at 170 ° C for 5 minutes. The substrate was inspected with a scanning electron microscope (SEM: Hitachi, Model S-4700) and the cleaning power was evaluated by the number of foreign particles remaining on the surface of the substrate. The results are shown in Table 1 and Fig. 1 and Fig. 2 below.

2. Evaluation of Damage to Polyimide Orientation Film

100 ml of the cleaning liquid composition prepared in Examples 1 to 4 and Comparative Examples 1 to 3 were placed in a 250 ml beaker and immersed for 30 minutes in a glass substrate on which a polyimide alignment film was formed. The substrate was taken out, washed with water, and water on the surface of the substrate was removed with nitrogen gas, followed by drying. The degree of damage of the polyimide alignment film was visually observed and examined with a scanning electron microscope (SEM: Hitachi, Model S-4700). The test results are shown in Table 1 below.

Alkaline component Lower alcohol Glycol ether water
Cleaning power PI damage Example 1 - IPA
5 wt% BDG
5 wt% Balance ◎ none Example 2 - IPA
5 wt% MDG
5 wt% Balance ◎ none Example 3 - IPA
1 wt% BDG
10 wt% Balance ◎ none Example
4 - ethanol
10 wt% BDG
5 wt% Balance ◎ none Comparative Example 1 TMAH
0.5 wt% - - Balance ◎ Complete exfoliation Comparative Example 2 - - BDG
20 wt% Balance △ none Comparative Example 3 - - - water
(100%) × none

[Cleaning performance]?: Very good,?: Good,?: Fair, X: Bad

IPA: isopropanol

MDG: diethylene glycol monomethyl ether

BDG: diethylene glycol monobutyl ether

TMAH: Tetra methyl ammonium hydroxide.

From the results shown in Table 1, it was confirmed that all the cleaning liquid compositions of Examples 1 to 4 of the present invention exhibit excellent cleaning power and do not cause damage to the polyimide alignment layer. On the other hand, the cleaning liquid composition of Comparative Example 1 containing a small amount of alkaline compound completely removed the PI alignment layer and was not usable. In addition, the cleaning liquid composition of Comparative Example 2 had a cleaning effect on foreign matter, but organic substances remained on the substrate to form a stain, resulting in defects. In addition, the cleaning liquid composition of Comparative Example 3 prepared with pure water did not damage the polyimide alignment film, but the cleaning power was low, resulting in defects.

FIG. 1 is a photograph of a polyimide alignment film substrate processed by the method of Test Example 1 using a cleaning liquid of Example 1 of the present invention, by a scanning electron microscope (SEM). FIG.

2 is a photograph of a polyimide alignment film substrate processed by the method of Test Example 1 using a cleaning liquid of Comparative Example 3 of the present invention by scanning electron microscope (SEM).

Claims (7)

An aqueous cleaning composition composition which does not contain an alkaline compound is characterized in that it contains 0.1 to 15% by weight of a lower alcohol of C1 to C5, 0.1 to 15% by weight of a water-soluble glycol ether compound and water in a residual amount based on the total weight of the composition By weight. The aqueous cleaning liquid composition according to claim 1, wherein the aqueous cleaning composition is used for cleaning a substrate before and after a rubbing process of an alignment layer in a liquid crystal display process. The method of claim 1, wherein the C1 to C5 lower alcohol is at least one selected from the group consisting of methanol, ethanol, n-propanol, isopropanol, ethylene glycol, 1,2-propanediol, -Butanediol, 1,4-butanediol, glycerol, and 1,2,4-butanetriol. The aqueous cleaning liquid composition according to claim 1, wherein the water-soluble glycol ether is a C1-C10 water-soluble glycol ether. The method of claim 1, wherein the water soluble glycol ether is selected from the group consisting of ethylene glycol monomethyl ether (MG), diethylene glycol monomethyl ether (MDG), triethylene glycol monomethyl ether (MTG), polyethylene glycol monomethyl ether (MPG) Ethylene glycol monoethyl ether (EG), diethylene glycol monoethyl ether (EDG), ethylene glycol monobutyl ether (BG), diethylene glycol monobutyl ether (BDG), triethylene glycol monobutyl ether (BTG) (MFG), and dipropylene glycol monomethyl ether (MFDG). The aqueous cleaning composition according to claim 1, delete delete

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