WO2002064716A1

WO2002064716A1 - Microemulsion typed detergent aqueous composition for liquid crystal display panel

Info

Publication number: WO2002064716A1
Application number: PCT/KR2002/000218
Authority: WO
Inventors: Mi-Sun Ryu; Young-Ku Kang; Hyuk-Jin Cha; Jae-Hwan Lee; Sook-Young Choi; Seong-Jae Hong; Tae-Yeong Kim; Young-Keun Kim; Chun-Woo Yoo; Dae-Woo Lee; Keun-Joo Lee; Yong-Man Jung; Dong-Kun Koo; Yoo-Li Bae; Woong Kim; Chang-Jin Lee; Moo-Hyun Kwon; Chul-Woo Lee; Sang-Il Yoon
Original assignee: Adms Technology Co., Ltd.; Korea Research Institute Of Chemical Technology
Priority date: 2001-02-13
Filing date: 2002-02-09
Publication date: 2002-08-22

Abstract

The present invention relates to a microemulsion typed detergent aqueous composition for liquid crystal panel comprising 10 to 60 parts by weight of a mixture of nonionic surfactant of alkylene oxide adduct to aromatic alcohol with nonionic surfactant of alkylene oxide adduct to hydrocarbon alcohol in the ratio of 10:90 to 90:10 by weight; 1 to 30 parts by weight of nonionic surfactant of alkylene oside adduct to secondary alcohol having 4 to 20 carbon atoms; and 0.1 to 10 parts by weight of organic hydrocarbon solvent selected from the group consisting paraffinic hydrocarbon having 8 to 18 carbon atoms, olefinic hydrocarbon having 8 to 18 carbon atoms and their mixture. Because the aqueous detergent composition is microemulsion typed solution, the composition not only has excellent cleaning ability and rinsibility to the residual liquid crystal thanks to good affinity with liquid crystal, but also has excellent stability, and has little corrosiveness to the metal pad part, further can minimize the environmental pollution.

Description

MICROEMULSION TYPED DETERGENT AQUEOUS COMPOSITION FOR LIQUID CRYSTAL DISPLAY PANEL

TECHNICAL FIELD The present invention relates to a microemulsion typed detergent aqueous

composition for liquid crystal display panel, more particularly, to an aqueous detergent

composition not only has excellent cleaning ability and rinsibility to the residual liquid

crystal thanks to good affinity with liquid crystal, but also has excellent stability against

fire because of low flammability, and has little corrosiveness to the metal pad part, further can minimize the environmental pollution.

BACKGROUND ART

Generally, liquid crystal display is manufactured by the steps of laying out two substrates facing each other, forming a certain distance between the substrates with

spacer, dipping into liquid crystal after folding the substrates each other and then

injecting the liquid crystal with vacuum. Here, if the liquid crystal remains on the outer

surfaces of the substrates in which the liquid crystal was injected, it is difficult to obtain

highly clear display and badness may also occur when packaging, so the residual liquid

crystal on the substrate should be removed by cleaning.

Commercially, such as trichlorotrifluoroethane, 1,1 ,1-trichloroethane, etc., are

used as detergents for removal of the residual liquid crystal. But, the use of such α -

halogenhydrocarbon compounds are restricted because they release harmful materials and bring about environmental pollutions such as depletion of ozone layer.

In order to solve these problems, Japanese patent laid-open No. 4-170500 and

Japanese patent laid-open No. 4-318100 disclose alkylene oxide adducts containing short-chain or long-chain alkyl group, and Japanese patent laid-open No. 11-92791

discloses an aqueous detergent composition comprising benzylic or phenylic nonionic

surfactants of short-chain or long-chain alkylene oxide adduct and alkylene glycol.

However, when such nonionic surfactants of alkylene oxide adduct to primary alcohol

having linear alkyl group are used, the surfactants do not show sufficient detergency

because the viscosity of the detergent composition is high and the permeability is

lowered, and the cleaning ability and emulsifying ability is poor because the affinity with

liquid crystal having large alkyl chain is insufficient.

To improve the cleaning ability to liquid crystal, Japanese patent laid-open No.

7-133496 discloses a detergent composition comprising nonionic surfactant of

paraffinic or olefinic hydrocarbon made by adding alkylene oxide to primary alcohol

having long-chain alkyl group of 8 to 16 carbon atoms and organic solvent. But, this

detergent has problems in that it induces the environmental pollutions because of the excess use of organic solvent for the purpose of improvement of the cleaning ability

and that it is highly flammable. Further, Japanese patent laid-open No. 10-251216

discloses an aqueous ionic detergent containing alkylether sulfuric ester salt to improve

the cleaning ability, but it also suffers a problem in that the ions contained to this

detergent corrode the metal pad loaded to liquid crystal display panel. Besides,

cleaning methods of liquid crystal using saccarides or alcohols was also utilized.

Though these materials are not harmless to environment, the cleaning ability to liquid

crystal is not sufficient.

DISCLOSURE OF THE INVENTION

Accordingly, it is an object of the present invention to provide an aqueous detergent composition not only has excellent cleaning ability and rinsibility to the

residual liquid crystal thanks to good affinity with liquid crystal, but also has excellent

stability against fire because of low flammability, and has little corrosiveness to the

metal pad part, further can minimize the environmental pollution.

To achieve the object above-mentioned, the present invention provide a

comprising:

10 to 60 parts by weight of a mixture of nonionic surfactant represented by

following general formula 1 with general formula 2 in the ratio of 10:90 to 90:10 by weight;

1 to 30 parts by weight of nonionic surfactant represented by following general

formula 3; and 0

0.1 to 10 parts by weight of organic hydrocarbon solvent selected from the

group consisting paraffinic hydrocarbon having 8 to 18 carbon atoms, olefinic

hydrocarbon having 8 to 18 carbon atoms and their mixture:

[general formula 1]

wherein R1 is one selected from the group consisting of hydrogen atom, alkyl

group having 1 to 12 carbon atoms and alkenyl group having 2 to 12 carbon atoms, R2

is one selected from the group consisting of hydrogen atom, methyl, formyl and acetyl,

AO represents oxyethylene or oxypropylene, m is an integer ranging 0 to 4 and n is an

integer ranging 1 to 10 (wherein each of AO may be the same or different when n is not less than 2); [general formula 2]

R3— O— (AO)— R4

wherein R3 is one selected from the group consisting of alkyl group having 8 to 18 carbon atoms and alkenyl group having 14 to 24 carbon atoms, R4 is one selected from the group consisting of hydrogen atom, methyl, formyl and acetyl, AO represents oxyethylene or oxypropylene and p is an integer ranging 1 to 20 (wherein each of AO may be the same or different when p is not less than 2); [general formula 3]

R5

HC — 0 — (AO)qH

I

R6

wherein, R5 is methyl, R6 represents the secondary alcohol having alkyl group of 4 to 20 carbon atoms, AO represents oxyethylene or oxypropylene, q is an integer ranging 1 to 20 (wherein each of AO may be the same or different when q is not less than 2). Further, to achieve the object above mentioned, the present invention provides a microemulsion typed detergent aqueous composition for liquid crystal display panel comprising:

10 to 60 parts by weight of a mixture of nonionic surfactant represented by following general formula 1 with general formula 2 in the ratio of 10:90 to 90:10 by weight;

2 to 50 parts by weight of glycol ether solvent represented by following general

formula 4; and

0.1 to 10 parts by weight of organic hydrocarbon solvent selected from the

group consisting paraffinic hydrocarbon having 8 to 18 carbon atoms, olefinic

hydrocarbon having 8 to 18 carbon atoms and their mixture:

[general formula 1]

wherein R1 is one selected from the group consisting of hydrogen atom, alkyl

integer ranging 1 to 10 (wherein each of AO may be the same or different when n is not

less than 2);

[general formula 2]

R3— O— (AO)— R₄

wherein R3 is one selected from the group consisting of alkyl group having 8 to

18 carbon atoms and alkenyl group having 14 to 24 carbon atoms, R4 is one selected

from the group consisting of hydrogen atom, methyl, formyl and acetyl, AO represents oxyethylene or oxypropylene and p is an integer ranging 1 to 20 (wherein each of AO

may be the same or different when p is not less than 2); [general formula 4]

R7— O - (AO) — R8

wherein, R7 represents alkyl group having 1 to 6 carbon atoms or alkenyl group

having 2 to 6 carbon atoms, R8 is one selected from the group consisting of alkyl group

having 1 to 6 carbon atoms, alkenyl group having 2 to 6 carbon atoms and acyl group having 1 to 6 carbon atoms, AO represents oxyethylene or oxypropylene and r is an

integer ranging 1 to 4 (wherein each of AO may be the same or different when r is not

less than 2).

According to the aqueous detergent composition, it is preferable that the

content of pure water is 5 to 70 parts by weight. And, an α -olefin having 10 to 16

carbon atoms is preferably used as the organic hydrocarbon solvent.

The details of the present invention will be described as follows.

Liquid crystal used for liquid crystal display (LCD) is commonly a compound

containing polar part consisting of aromatic or cyclic hydrocarbon and nonpolar part

consisting of long alkyl chain simultaneously. To clean such liquid crystal, solvents

having high affinity with liquid crystal compound should be used. Therefore, paraffinic

or olefinic organic hydrocarbon solvent is commonly used, but such organic solvents

are immiscible with water, so surfactant must be added for preparing aqueous

detergents.

To obtain superior cleaning ability and rinsibilty, microemulsion typed solution is

more advantageous than normal emulsion typed solution. The surfactants commonly

used for preparing microemulsion typed solution are ionic surfactants such as alkane sulfonate salt and alkane phosphate salt. But, such sulfonate salts or phosphate salts

are remained at the cleaning solution and corrode the metal part of liquid crystal panel

as well as cause to pollute water because they are not easily decomposed when

discharged to waste water, so their use is gradually limited.

Therefore, the aqueous detergent composition according to the present

invention comprises nonionic surfactants represented by the following general formula

1 and 2 that show highly excellent affinity respectively with the polar and nonpolar parts of liquid crystal compounds containing both polar part composed of aromatic or cyclic

hydrocarbon and nonpolar part composed of long alkyl chain. Further, because the

composition is microemulsion-typed aqueous detergent containing paraffinic or olefinic

organic hydrocarbon solvent which are highly friendly with liquid crystal, the cleaning

ability and rinsibility are excellent. Furthermore, the nonionic surfactants of alkylene

oxide adduct as represented by the general formula 1 and 2 are easily decomposed by

such as bacteria when discharged to waste water, thus can minimize the environmental

pollution by the waste water,

[general formula 1]

Wherein R1 is one selected from the group consisting of hydrogen atom, alkyl

integer ranging 1 to 10 (wherein each of AO may be the same or different when n is not less than 2).

Examples of the alkyl group having 1 to 10 carbon atoms include methyl, ethyl, isopropyl, butyl, isobutyl, amyl, nonyl, and the like. Considering the cleaning ability and rinsibility, the alkyl group having 1 to 5 is preferred for use. And, examples of the alkenyl group having 2 to 12 carbon atoms include vinyl, 1-prophenyl, aryl, 1-butenyl,

2-penthenyl, and the like. In consideration of the deterioration of cleaning ability due to lowering of solubility to water, the preferred for use is alkenyl group having 2 to 5 carbon atoms, more preferably 2 or 3. Further, to maximize the cleaning ability, R1 is preferably hydrogen atom. And, considering the cleaning ability, R2 is preferably hydrogen atom. Furthermore, m is preferably an integer ranging 0 to 4 considering the facility of purchasing the raw material and preventing lowering of solubility to water. And, n is preferably an integer ranging 1 to 4 as a factor to control the solubility to water and the cleaning ability.

Examples of compound represented by the general formula 1 include ethylene oxide adduct or propylene oxide adduct to various alcohols such as phenolic alcohols such as phenol, methylphenol, ethylphenol, isopropylphenol or vinylphenol, benzylicalcohols such as benzylalcohol, methylbenzylalcohol, ethylbenzylalcohol or isopropylbenzylalcohol and aromatic alcohol such as phenylethylalcohol. Moreover, other examples include methylether, formylether or acetylether thereof. These compounds can be used alone or in combination of two or more thereof. Among them, alkylene oxide adduct to phenol, methylphenol, ethylphenol, benzylalcohol and phenylethylalcohol are more preferable for use in order to enhance the cleaning ability and rinsibility.

[general formula 2] R3— O— (AO)— R4

Wherein R3 is one selected from the group consisting of alkyl group having 8 to

from the group consisting of hydrogen atom, methyl, formyl and acetyl, AO represents

oxyethylene or oxypropylene and p is an integer ranging 1 to 20 (wherein each of AO

may be the same or different when p is not less than 2).

Examples of the alkyl group having 8 to 18 carbon atoms include octyl, 2-

ethylhexyl, decyl, lauryl, cetyl, stearyl, isodecyl, tridecyl, isotridecyl and the like. In

consideration of the cleaning ability and rinsibility, octyl, decyl, lauryl or tridecyl is

preferred for use. Further, an example of the alkenyl group having 8 to 18 carbon

atoms is nonyl, and, the examples of the alkylphenyl group having 14 to 24 carbon

atoms include octylphenyl, nonylphenyl, dodecylphenyl and the like. Considering the

cleaning ability, the more preferred R3 for use is alkenyl having 8 to 14 carbon atoms.

In order to improve the rinsibility, R4 is preferably hydrogen atom. Furthermore, p is

preferably an integer ranging 4 to 12 in consideration of the rinsibility and lowering of

the cleaning ability due to increase of viscosity.

Examples of compound represented by the general formula 2 include ethylene

oxide adduct or propylene oxide adduct to various alcohols such as octyl alcohol, 2-

ethylhexyl alcohol, decyl alcohol, lauryl alcohol, high molecular weight alcohols of 11 to

15 carbon atoms having primary or secondary hydroxide functional group and linear or

branched alkyl or alkenyl group, such as undecylalcohol, dodecyl alcohol, cetyl alcohol,

stearyl alcohol or oleyl alcohol, and phenolic alcohol such as octylphenol, nonylphenol or dodecylphenol, and methylether or acylether thereof. These compounds are

produced in the name of OTA-2, OTA-3, OTA-4, OTA-5, OTA-8, OTA-10, etc., by IC

Chem Co., LTD, the manufacturer of surfactants, in Korea. These surfactants may be

used alone or in combination of two or more thereof.

Among them, akylene oxide adduct to alcohols having alkyl of 8 to 14 carbon

atoms are advantageously used in order to improve the rinsibility and cleaning ability.

The mixing ratio of above mentioned general formula 1 and general formula 2

(the weight ratio of compound of general formula 1 / compound of general formula 2) is

10/90 to 90/10, preferably from 30/70 to 80/20. In consideration of the cleaning ability

and rinsibility, the content of the mixture of nonionic surfactant mixed in the ratio above

mentioned is preferably 10 to 60 parts by weight. Because the detergent composition

having higher flash point than 80 to 100^°C according to the mixing ratio of such

surfactants with pure water can be prepared, the stability against fire become higher.

As an organic hydrocarbon solvent contained in the aqueous detergent solution

according to the present invention, paraffinic or olefinic hydrocarbon having 8 to 18

carbon atoms of high flash point is used in order to prevent ignition. Especially, α -

olefin having 10 to 16 carbon atoms is preferable for use. Examples of organic

hydrocarbon solvent include decene, undecene, octadecene, hexadecene and the like.

These compounds may be used alone or in combination of two or more thereof. The

content of organic solvent is 0.1 to 10 parts by weight, preferably 0.1 to 5 parts by

weight to improve the cleaning ability and to prevent environmental pollution.

The detergent composition according to present invention is aqueous solution,

and the water improves the stability against flammability and the cleaning ability of the composition. The water for the aqueous detergent composition according to the

present invention is preferably purified water such as deionized or distilled water. And

the content of water is preferably 5 to 70 parts by weight, and more preferably 10 to 60

parts by weight in consideration of the stability against flammability and the cleaning

ability.

The detergent composition according to present invention comprises nonionic

surfactant represented by the following general formula 3, which is an alkylene oxide

adduct to secondary alcohol having alkyl of 4 to 20 carbon atoms. Or, the detergent

composition comprises glycol ether solvent represented by following general formula 4.

The nonionic surfactant represented by general formula 3 lowers the viscosity of the

detergent composition to improve the cleaning ability and rinsibility more and to

minimize generation of air bubble. Further, glycol ether solvent of general formula 4

improves the cleaning ability of the detergent composition more,

[general formula 3]

R5

I

HC — O — (AO)qH

R6

Wherein R5 is methyl, R6 represents the secondary alcohol having alkyl group of 4 to 20 carbon atoms, AO represents oxyethylene or oxypropylene, q is an integer

ranging 1 to 20 (wherein each of AO may be the same or different when q is not less

than 2). Examples of R6 include sec-butyl, sec-hexyl, sec-dodecyl and the like, and

among them, glycol ether solvent having alkyl of 5 to 14 carbon atoms is preferable for use from the point of view of improvement of the cleaning ability. And, because the

cleaning ability of oxyethylene or oxypropylene group is lowered as the hydrophilicity

become stronger, q is preferably an integer ranging 1 to 20, more preferably 5 to 12.

The content of the nonionic surfactant represented by general formula 3 is 1 to 30 parts

by weight considering the cleaning ability of the detergent composition to liquid crystal, preferably 5 to 20 parts by weight,

[general formula 4]

R7— O - (AO) —

Wherein R7 represents alkyl group having 1 to 6 carbon atoms or alkenyl group

having 1 to 6 carbon atoms, alkenyl group having 2 to 6 carbon atoms and acyl group

having 1 to 6 carbon atoms, AO represents oxyethylene or oxypropylene and r is an

integer ranging 1 to 4 (wherein each of AO may be the same or different when r is not less than 2).

Examples of the alkyl group having 1 to 6 carbon atoms include methyl, ethyl,

n-propyl, isopropyl, n-butyl, isobutyl, amyl, n-hexyl, and the like. Considering the

cleaning ability, the alkyl group having 2 to 4 is preferred for use. And, examples of the

alkenyl group having 2 to 6 carbon atoms include vinyl, 1-prophenyl, aryl, 1-butenyl, 2- penthenyl, and the like. In consideration of the cleaning ability, the preferred for use is

alkenyl having 2 to 4 carbon atoms.

Examples of such glycol ether solvent include ethylene oxide or propylene

oxide adduct to methylalcohol, ethylalcohol, n-propanol, isopropanol, n-butanol, iso-

butanol, amylalcohol, n-hexanol, vinylalcohol, and the like, and alkylether, alkenylether or acylether thereof. More precisely, diethylene glycol diethylether, diethylene glycol

dibutylether, diethylene glycol ethylbutylether, diethylene glycol methylbutylether,

triethylene glycol dimethylether, dipropylene glycol dimethylether and the like could be

advantageously used in order to improve the cleaning ability to liquid crystal. Such

glycol ether solvent may be used alone or in combination of two or more thereof, and

the content of such glycolether solvent is 2 to 50 parts by weight in consideration of the

cleaning ability of the detergent composition to the liquid crystal, preferably 5 to 30

parts by weight.

To the microemulsion typed detergent aqueous composition for liquid crystal

display panel according to the present invention, other additives such as anticorrosion

agent to minimize corrosion of metal and anti-foaming agent to prevent occurrence of

air bubble may be added in the amount of 0.01 to 2 parts by weight.

The microemulsion typed detergent aqueous composition for liquid crystal

display panel according to the present invention can be prepared by general

preparation method of microemulsion. And the prepared detergent composition may be

used for cleaning glass substrate as well as for cleaning the tools. Such aqueous

detergent composition could be easily removed by rinsing with water if the detergent

composition for liquid crystal is remained on the surface of the subjects after cleaning.

The cleaning method of liquid crystal using the detergent aqueous composition

according to the present invention is, not for particular limitation, ultrasonic cleaning

method, vibration method, spraying method and rinsing method with solvent or hot water after dipping and cleaning may be available. Among them, vibration method or

spraying method is appropriately used for the present method. Brief description of figures

Fig. 1 a is a photograph of SEM (scanning electron microscope) taken in

nonpolarized state before cleaning of liquid crystal cell.

Fig. 1 b is a photograph of SEM (scanning electron microscope) taken in

polarized state before cleaning of liquid crystal cell.

Fig. 2a is a photograph of SEM (scanning electron microscope) taken in

nonpolarized state after cleaning using the detergent composition in accordance with

an embodiment of the present invention.

Fig. 2b is a photograph of SEM (scanning electron microscope) taken in

polarized state after cleaning using the detergent composition in accordance with an

embodiment of the present invention.

Embodiments

The more detail description of the present invention is best understood with

reference to the preferred embodiments. But the preferred embodiments of the present

invention can be variously modified, and, the range of the present invention should not

be limited to the following embodiments. The embodiments of the present invention are

provided for illustrating the present invention more completely to those skilled in the art.

Embodiment 1 to 20

To the mixer in which agitator is installed, the components and contents

described as following table 1 and 2 are added consecutively, then they are agitated for

0.5 to 3 hours at room temperature in the speed of 200 to 600 rpm to prepare

microemulsion typed detergent aqueous compositions.

Comparative example 1 to 10

Detergent compositions are prepared in the same method of embodiment 1 except that the components and contents are varied as described as following table 3.

Embodiment 21 to 40

To the mixer in which agitator is installed, the components and contents

described as following table 4 and 5 are added consecutively, then they are agitated for

0.5 to 3 hours at room temperature in the speed of 200 to 600 rpm to prepare

microemulsion typed detergent aqueous compositions.

Comparative example 1 to 20

Detergent compositions are prepared in the same method of embodiment 1

except that the components and contents are varied as following table 6.

The cleaning ability, rinsibility, flammability and anti-corrosiveness of the

detergent composition prepared as above-described embodiments and comparative

examples are evaluated by the following method. Particularly, in order to observe the

effect of low foamibility and lowering of viscosity, the foamibility and the viscosity of the

detergent compositions in accordance of embodiments 1 to 20 and comparative

examples 1 to 10 was measured and compared.

After setting 10 μ of spacer on a glass plate, another glass plate of the same

size was put on it. And, a cell was manufactured by injecting liquid crystal to the gap

between the two glass plates. Then, the edge of the cell was sealed with thermosetting

epoxy adhesive to prevent the liquid crystal leaking. Thus, prepared cell was observed

to discern the amount of alien substances on the outer surface of glass plates by

polarized microscope before cleaning. Next, the manufactured cell was inputted into

700mL of the detergent composition according to the embodiments and comparative

examples maintaining 40 ^°C, and ultrasonic cleaning was performed with ultrasonic cleaner for 10 minutes. And then the cell was taken out and rinsed with deionized water of 40 °C using ultrasonic cleaner for 5 minutes. Next, the cell was dried after rinsing

twice times in the same method. Then, the cleaned cell was observed with polarized microscope. The cleaning ability was evaluated on the basis of the following criteria by estimating the amount of remaining liquid crystal comparing the state of liquid crystal cell before and after cleaning.

O : the gap is cleaned for the most part.

Δ : small amount of liquid crystal is remained at the gap.

x : large amount of liquid crystal is remained at the gap.

The rinsibility of the cell manufactured by the same method of said evaluation method of the cleaning ability was estimated on the basis of the following criteria by comparing the state of liquid crystal cell before and after cleaning. © : the detergent composition for liquid crystal is not at all attached on the

surface of the glass.

O : the detergent composition for liquid crystal is not attached on the surface of

the glass for the most part. Δ : small amount of the detergent composition for liquid crystal is attached on

the surface of the glass.

x : large amount of the detergent composition for liquid crystal is attached on

the surface of the glass.

<Evaluation of the flammability> The flammability of the detergent composition according to embodiments and

comparative examples are estimated by the method, KS M 2010 of Korean Industrial

Standard on the basis of 1 clause, 12 article of the Enforcement Ordinance of the Fire

Services Act in Korea.

The composition is expressed as 'None' of flammability when it corresponds to

the non-dangerous material, and 'Being' of flammability when it corresponds to the

dangerous material.

The anti-corrosiveness was evaluated by measuring the electroconductivity of

the surface of the metal after dipping the metal into the detergent composition

according to embodiments and comparative examples and taking it out. When the

electroconductivity is maintained as the same that of the start, the anti-corrosiveness

was evaluated as 'Good', and when the electroconductivity decreased to a certain

amount, the anti-corrosiveness was evaluated as 'Normal', and when the

electroconductivity wasn't measured, the anti-corrosiveness was evaluated as 'Bad'.

The foamibility was evaluated by measuring the height of generated bubble

after inputting 1 mL of the detergent composition according to embodiments and

comparative examples into 10 mL glass tube, and bubbling with nitrogen gas for 1

minute at a certain pressure.

The foamibility was estimated to 3 levels as bellows.

O : 5 to 10 mm. x : not les than 11 mm.

Further, the foamibility of the detergent composition was evaluated by measuring the height of bubble after letting as it is for 10 minutes.

The viscosity of the detergent composition according to embodiments and comparative examples was evaluated using UL-adaptor(manufactured by Brookfield Co.) at room temperature (25 °C), at the speed of 30 rpm.

[TABLE 1 ]

[ TABLE 2]

[ TABLE 3]

[ TABLE 4]

[ TABLE 5]

[ TABLE 6]

** In above Table 1 and 2, BZE-102A is a product produced by Hannong Chemicals Inc., Monopol LE-1017 is a product produced by Dongnam Chemicals Ind., LTD., and OTA-5 is a product produced by IC Chem Co., LTD., all the manufacturers are in Korea.

Referring above Table 1 to 6, the microemulsion typed detergent aqueous composition for liquid crystal display panel of the present invention shows excellent cleaning ability and rinsibility to liquid crystal remained on the gap part of glasses around the cell, and is nonflammable, and is non-corrosive to metal. Particularly, the aqueous detergent composition containing nonionic surfactant having alkyl of secondary alcohol (embodiment 1 to 20) is more excellent of the cleaning ability and rinsibility to liquid crystal thanks to low viscosity and low foamibility of the detergent composition.

Fig. 1a is a photograph of SEM(scanning electron microscope) taken in

nonpolarized state before cleaning of liquid crystal cell, and Fig. 1 b is a photograph of

SEM(scanning electron microscope) taken in polarized state before cleaning of liquid

crystal cell.

And, Fig. 2a is a photograph of SEM(scanning electron microscope) taken in

an embodiment of the present invention, and Fig. 2b is a photograph of SEM(scanning

electron microscope) taken in polarized state after cleaning using the detergent

composition in accordance with an embodiment of the present invention. As shown at

Fig. 2a and Fig. 2b, it can be ascertained that when being cleaned by the detergent

composition according to the present invention, the liquid crystal is finely cleaned in

comparison with before cleaning (referring to the liquid crystal (1 ) of Fig. 1 a and Fig.

1 b). As mentioned above, thanks to high affinity with liquid crystal, the

microemulsion typed detergent aqueous composition for liquid crystal display panel of

the present invention shows excellent cleaning ability and rinsibility to liquid crystal and

shows remarkable stability against fire because of low flammability. Further, it is little

corrosive to metal pad, and can minimize the environmental pollution. Therefore, the

aqueous detergent composition according to the present invention can be used to

clean the pollutant such as liquid crystal attached on the surface of substances such as

glass substrate and tools, and can also be easily rinsed.

Claims

What is claimed is:

1. A microemulsion typed detergent aqueous composition for liquid crystal display panel comprising:

10 to 60 parts by weight of a mixture of nonionic surfactants represented by following general formula 1 and following general formula 2 in the ratio of 10:90 to

90:10 by weight;

1 to 30 parts by weight of nonionic surfactant represented by following general formula 3; and

0.1 to 10 parts by weight of organic hydrocarbon solvent selected from the group consisting paraffinic hydrocarbon having 8 to 18 carbon atoms, olefinic hydrocarbon having 8 to 18 carbon atoms and mixtures thereof: [general formula 1]

wherein R1 is one selected from the group consisting of hydrogen atom, alkyl group having 1 to 12 carbon atoms and alkenyl group having 2 to 12 carbon atoms, R2 is one selected from the group consisting of hydrogen atom, methyl, formyl and acetyl, AO represents oxyethylene or oxypropylene, m is an integer ranging 0 to 4 and n is an

R3— O— (AO)— R wherein, R3 is one selected from the group consisting of alkyl group having 8

to 18 carbon atoms and alkenyl group having 14 to 24 carbon atoms, R4 is one

selected from the group consisting of hydrogen atom, methyl, formyl and acetyl, AO represents oxyethylene or oxypropylene and p is an integer ranging 1 to 20 (wherein

each of AO may be the same or different when p is not less than 2);

[general formula 3]

R5

HC — O — (AO)qH

I

R6

wherein, R5 is methyl, R6 represents the secondary alcohol having alkyl group

of 4 to 20 carbon atoms, AO represents oxyethylene or oxypropylene, q is an integer

than 2).

2. A microemulsion typed detergent aqueous composition for liquid crystal

display panel comprising: 10 to 60 parts by weight of a mixture of nonionic surfactants represented by

following general formula 1 and following general formula 2 in the ratio of 10:90 to

90:10 by weight;

formula 4; and 0.1 to 10 parts by weight of organic hydrocarbon solvent selected from the

group consisting paraffinic hydrocarbon having 8 to 18 carbon atoms, olefinic hydrocarbon having 8 to 18 carbon atoms and their mixture:

[general formula 1]

wherein R1 is one selected from the group consisting of hydrogen atom, alkyl

less than 2); [general formula 2]

R3— O— (AO)— R4

wherein, R3 is one selected from the group consisting of alkyl group having 8

to 18 carbon atoms and alkenyl group having 14 to 24 carbon atoms, R4 is one

selected from the group consisting of hydrogen atom, methyl, formyl and acetyl, AO

represents oxyethylene or oxypropylene and p is an integer ranging 1 to 20 (wherein

each of AO may be the same or different when p is not less than 2);

[general formula 4]

R7— O - (AO) — R8

wherein, R7 represents alkyl group having 1 to 6 carbon atoms or alkenyl

group having 2 to 6 carbon atoms, R8 is one selected from the group consisting of alkyl group having 1 to 6 carbon atoms, alkenyl group having 2 to 6 carbon atoms and acyl group having 1 to 6 carbon atoms, AO represents oxyethylene or oxypropylene and r is an integer ranging 1 to 4 (wherein each of AO may be the same or different when r is not less than 2).

3. The composition according to claim 1 or 2, wherein the content of pure water is 5 to 70 parts by weight.

4. The composition according to claim 1 or 2, wherein the organic hydrocarbon solvent is an α -olefin having 10 to 16 carbon atoms.