JPH04252299A - Detergent composition for liquid crystal cell - Google Patents

Abstract

PURPOSE:To provide the subject aqueous composition containing a specified nonionic surfactant, a silicate and a chelating agent, capable of effectively cleaning stains of a liquid crystal cell generated in encapsulation of a liquid crystal without requirement of a fluorocarbon-based solvent and excellent in environmental health. CONSTITUTION:An objective composition containing (A) a nonionic surfactant represented by the formula (R1 is 6-12C alkyl or alkenyl; n is 2-4; m is >=3) preferably in an amount of 10-60wt.% (especially 20-60wt.%), (B) a silicate such as sodium orthosilicate preferably in an amount of 1-20wt.% (especially 5-20wt.%) and (C) a chelating agent such as nitrilotriacetic acid, ethylenediaminetetraacetic acid, diethylenetriaminepentaacetic acid or hydroxyethanediphosphonic acid preferably in an amount of 0.05-20wt.% (especially 1.0-20wt.%).

Description

Description: [0001] The present invention relates to a cleaning composition for liquid crystal cells using glass substrates and the like. [Prior Art] A liquid crystal cell using a glass substrate has a thickness of 10 μm.
Two glass substrates are bonded together using an adhesive to form a hollow interior while maintaining an appropriate distance of less than m, and then a liquid crystal is sealed in the hollow portion. The inner surfaces of the two glass substrates have electrodes for displaying characters and images made of transparent conductive films, and by applying control electrical signals to these electrodes, characters, images, etc. can be displayed. [0003] Liquid crystal cells inherently consume less power, and as a result of technological improvements such as higher contrast in recent years, it has become possible to display more delicate and diverse images, such as for computer terminal displays and televisions. As time goes by, its uses are expanding. However, in order to display delicate images,
In order to apply the above-mentioned electrical control signals, several thousand electrode terminals formed on the end surface of the glass substrate must be arranged in one display cell at intervals of 3 to 10 terminals/mm.
High-density wiring is progressing. To give an example of the arrangement of these electrode terminal wirings, the conductor width of the conductor terminal part is 100 to 300 μm.
In order to electrically insulate and separate several thousand conductor terminals from one another, the terminal wiring spacing must be very narrow, 10 to 30 μm, in order to maintain image display quality. For this reason, it is not easy to maintain insulation between terminal wirings, and even the presence of even a small amount of contaminants on the terminal surface may cause image display defects due to poor insulation.
When humidity is added, electrolytic corrosion causes problems such as wire breakage and destruction of the display function of the liquid crystal cell. Particularly in a liquid crystal cell, liquid crystal sucked between the substrates outside the liquid crystal chamber when the liquid crystal cell is injected causes contamination. [0007] When manufacturing a liquid crystal cell, in order to seal liquid crystal between two substrates on which transparent electrodes are formed, a liquid crystal chamber is created by bonding the upper and lower substrates together at their peripheries with an adhesive, leaving a partial opening. form and create an empty liquid crystal cell. The opening of this empty cell is immersed in liquid crystal material in a vacuumed injection chamber, and then the injection chamber is opened to the atmosphere, which draws the liquid crystal material between the substrates (inside the liquid crystal chamber) and seals the opening. By doing so, a liquid crystal cell is formed in which a liquid crystal substance is sealed between the substrates. [0008] However, it is unavoidable that a gap is formed outside the bonded portion of the two liquid crystal cell substrates, where the liquid crystal cell substrates face each other with a small gap. Therefore, when liquid crystal is injected into the empty cell, the liquid crystal enters the gap due to capillary action. If this liquid crystal is left as is, it is likely to dissolve pollutants in the atmosphere and cause insulation failure, so it is necessary to wash and remove the liquid crystal. but,
Since the gap of this cavity is narrow, 10 μm or less, it is difficult to clean and remove the liquid crystal that has entered. [0009] For the above reasons, CFC-based solvents or chlorinated solvents, which have a high degree of cleaning ability and do not leave contaminating residues, have conventionally been used as cleaning agents for completed liquid crystal cells. . However, while these solvents have excellent cleaning performance, they have serious environmental safety problems, and in recent years, there has been an increasing demand for water-based cleaning agents. OBJECTS OF THE INVENTION The present invention provides a cleaning composition that exhibits extremely excellent cleaning performance for liquid crystal cells and does not cause environmental pollution. Structure of the Invention The cleaning agent for liquid crystal cells of the present invention has the following (a)
) to (c). (a) A nonionic surfactant represented by the following chemical formula 2. (b) Silicates. (c) Chelating agent. [0012] (R1: Alkyl group or alkenyl group having 6 to 12 carbon atoms n: 2 to 4 m: Represents the number of moles of alkylene oxide added, a number of 3 or more. However, the same alkylene oxide is The present invention will be explained in more detail below. The nonionic surfactant as component (a) is an alkylene oxide adduct of an alkyl or alkenylphenol, and the alkyl or alkenyl group preferably has 8 to 9 carbon atoms. As the alkylene oxide, ethylene oxide, propylene oxide, and butylene oxide are added, and ethylene oxide or propylene oxide is particularly preferred. These alkylene oxides may be added singly or in a mixture of two or more. In the case of mixed addition, block addition or random addition may be used. The number of moles of alkylene oxide added is 3 or more, preferably 5 to 15. As the silicate of component (b), those represented by the following chemical formula 3 are suitable. [0016] aM2O.bSiO2 (M: alkali metal salt such as Na, K, etc. a: 1 to 3, preferably 1 to 2 b: 1 to 5, preferably 1 to 2 b/a: 0.3 ~4, preferably 0.5~1) 001
7] As the chelating agent for component (c), ethylenediaminetetraacetic acid, diethylenetriaminepentaacetic acid, nitrilotriacetic acid, hydroxyethanediphosphonic acid, or salts thereof are suitable. The liquid crystal cell cleaning composition of the present invention is prepared by blending the above components (a), (b), and (c). Here, the nonionic surfactant as component (a) has a concentration of 10 to 60
It is preferable to mix it in weight%, more preferably 20~
It is 60% by weight. Component (b) silicate is 1 to 20% by weight
It is preferably blended, and more preferably 5 to 20% by weight. In addition, the chelating agent (c) component is 0.05
The content is preferably from 1.0 to 20% by weight, more preferably from 1.0 to 20% by weight. The cleaning composition for liquid crystal cells of the present invention can take various forms such as liquid and powder, but it is usually diluted with water to form a transparent composition of 5 to 70% by weight. It is prepared and diluted about 10 times with water to make a cleaning solution. At that time, liquid stabilizers such as ethylene glycol, propylene glycol, methanol, ethanol, propanol, toluene sulfonate, xylene sulfonate, etc. can be added as necessary, and rust preventive agents such as benzotriazole, Preservatives such as benzoates and the like may also be added. Effects of the Invention According to the liquid crystal cell cleaning composition of the present invention, by using a specific nonionic surfactant, silicate and chelating agent in combination, liquid crystal cells can be cleaned by an aqueous cleaning solution. Dirt can be effectively cleaned. [Example] In Examples 1 to 43 described later, each cleaning agent was prepared, and its cleaning power was evaluated using the following evaluation method. [Cleaning power evaluation method] Liquid crystal is applied to the gap of a glass substrate liquid crystal cell and left to stand for 5 minutes. Confirm that the void is filled with liquid crystal using a polarizing microscope (20x magnification) and use it as a cleaning sample. Each of the prepared cleaning agents was diluted 10 times using pure water to prepare a cleaning solution. [0024] The cleaning solution was kept at 40°C (±0.5°C) in a constant temperature bath.
Place the cell to be cleaned and soak for 5 minutes. After washing, place in pure water at 25°C, shake and rinse 10 times, and air dry. The gap portion was observed using a polarizing microscope (×20), and the degree of cleaning was evaluated using the following evaluation criteria. Pass with a score of 3 or more. 5: Completely cleaned 4: Very good 3: Fairly good 2: Poor 1: Hardly cleaned Example 1 No. 1 shown in Tables 1 and 2 below. Cleaning compositions Nos. 1 to 15 were prepared, diluted 10 times with water, and their cleaning power was evaluated. Hereinafter, nonionic surfactants are indicated by the skeletal structure (such as phenol) to which alkylene oxide is added and the number of moles of alkylene oxide added. Moreover, EOp indicates the average number of added moles of ethylene oxide. EDTA refers to ethylenediaminetetraacetic acid. [Table 1] Table 1: Common composition Nonionic surfactant (listed in Table 2)
20wt% Sodium orthosilicate

5wt% (2Na2O・SiO2・xH2O,b
/a=0.5) EDTA-2Na
5wt
% water
Remainder [Table 2] Table 2: Types of nonionic surfactants, evaluation result No.
nonionic surfactant
Cleaning power 1 Nonylphenol EOp = 3
32 Nonylphenol
EOp= 5 4 3
Nonylphenol EO
p=10 44 nonylphenol
EOp=15
45 Nonylphenol
EOp=20 36 Nonylphenol EOp=25
37 Octylphenol
EOp= 3 38
Octylphenol EOp=
5 4 9 Octylphenol EOp=10
510 Octylphenol
EOp=15 411 Octylphenol EOp=20
312 Octylphenol
EOp=25 313*
Lauryl alcohol EOp
=10 214* laurylamine
EOp=10
215* Lauryl monoethanolamide E
Op=10 2 * No. Comparative Examples Nos. 13, 14, and 15 are Nos. 1 and 2 shown in Tables 3 and 4 below in Example 2. Cleaning compositions 16 to 26 were prepared, diluted 10 times, and their cleaning power was evaluated. [Table 3] Table 3: Common composition Octylphenol EOp=10
20wt% alkaline agent (Table 4
)
5wt% EDTA-2Na
5wt%
water
remainder
[Table 4] Table 4: Types of alkaline agents, evaluation result No. alkaline agent
Cleaning power 16
Sodium orthosilicate 2Na2O・Si
O2・xH2O 517 Sodium sesquisilicate 3Na2O・2SiO2・xH2O
418 Sodium metasilicate
Na2O・SiO2・xH2O 4
19 No. 1 Sodium Silicate Na2O・
2SiO2・aq*1 320 No. 2 Sodium Silicate 2Na2O・5SiO2・
aq*1 321 No. 3 Sodium Silicate
Na2O・3SiO2・aq*1
322 No. 4 Sodium Silicate N
a2O・4SiO2・aq*1 323*
caustic soda
224* Monoethanolamine
225* Diethanolamine
226* Triethanolamine
1 *) No. 23, 24, 25, 26 are comparative examples *1)
aq indicates an aqueous solution. In addition, the compounding amount in Table 3 is the pure content (
Example 3 No. 3 shown in Tables 5 and 6 below. Cleaning compositions No. 27 to 30 were prepared, diluted 10 times with water, and their cleaning power was evaluated. [Table 5] Table 5: Common composition Octylphenol EOp=10
20wt% Sodium orthosilicate
5wt% chelating agent (listed in Table 6)
5wt
% water
Remainder [Table 6] Table 6: Types of chelating agents, evaluation result No. chelating agent
Cleaning power 2
7 Nitrilotriacetic acid-3Na
528 Diethylenetriamine pentaacetic acid-5Na 5
29 Ethylenediaminetetraacetic acid-4Na
530 Hydroxyethanediphosphonic acid-4Na 5 Example 4 No. 4 shown in Tables 7 and 8 below. Cleaning compositions Nos. 31 to 36 were prepared, diluted 10 times with water, and their cleaning power was evaluated. [Table 7] Table 7: Common composition Octylphenol EOp=10
Listed in Table 8 Sodium orthosilicate

5wt% EDTA-2Na
5w
t% water
Remainder [Table 8] Table 8: Blend amount of octylphenol EOp=10, evaluation results No. Octylphenol EOp=
Blend amount of 10 Cleaning power 31
1wt%
332
5wt%
333
10wt%
434
20wt%
535
50wt%
536
60wt%
Example 5 No. 5 shown in Tables 9 and 10 below. Cleaning compositions Nos. 37 to 41 were prepared, diluted 10 times with water, and their cleaning power was evaluated. [Table 9] Table 9: Common composition Octylphenol EOp=10
20wt% Sodium orthosilicate
Listed in Table 10 EDTA-2Na

5wt% water

Remainder [0040] [Table 10] [0041] Example 6 No. 1 shown in Table 11 and Table 12 below. Cleaning compositions Nos. 42 to 47 were prepared, diluted 10 times with water, and their cleaning power was evaluated. [Table 11] Table 11: Common composition Octylphenol EOp=10
20wt% Sodium orthosilicate
5wt% EDTA-2Na
Table 10
Water listed inside
Balance [Table 12] Example 7 No. 1 shown in Table 13 and Table 14 below. Cleaning compositions No. 48 and 49 were prepared, diluted 10 times, and their cleaning power was evaluated. [Table 13] Table 13: Common composition Nonionic surfactant
(Types and amounts are listed in Table 12) Sodium orthosilicate
5wt% EDT
A-2Na
5wt% water

Remainder [Table 14] Table 14: Types of nonionic surfactants, evaluation result No.
nonionic surfactant
Cleaning power 48 Octylphenol EOp=8 10wt%
+
5
Octylphenol EOp=10 10wt%
49 Octylphenol EOp
=15・POp=3*1 4 *1) Mixed block adduct of 15 moles of ethylene oxide and 3 moles of propylene oxide

Claims (2)

[Claims] Claim 1: (a) A nonionic surfactant represented by formula 1 (R1: alkyl group or alkenyl group having 6 to 12 carbon atoms, n: 2 to 4 m: number of moles of alkylene oxide added) (Represented by a number of 3 or more. However, the same alkylene oxide may be added alone, or two or more types of alkylene oxides may be added as a mixture.) (b) Silicate (c) A cleaning composition for liquid crystal cells, characterized by containing a chelating agent. 2. The liquid crystal cell cleaning composition according to claim 1, wherein the chelating agent is one or more of nitrilotriacetic acid, ethylenediaminetetraacetic acid, diethylenetriaminepentaacetic acid, hydroxyethane diphosphonic acid, and salts thereof. .