JPH08269495A - Detergent for screen printing plate - Google Patents

Abstract

PURPOSE: To obtain a detergent for a screen printing plate, improved in stability, having usual detergency independent of the types of ink, free from environmental destruction since it is non-chlorinated, having low toxicity and satisfactory from the viewpoint of odor by blending a quaternary ammonium hydroxide with a detergent for screen printing plate. CONSTITUTION: A quaternary ammonium hydroxide represented by formula I (wherein R1 to R4 are each 1-6C alkyl) is added usually in an amount of 0.1-10wt.% to a detergent. In addition, the use of a compound represented by formula II (wherein R1 is 1-8C alkyl; R2 is H or 1-8C alkyl; n is 2 to 3; and m is 1 to 4) (e.g. an alkylene glycol monoalkyl ether) therewith is desirable since it enhances a cleaning effect. To clean a screen printing plate by using this detergent, the printing plate is immersed in the detergent heated from room temperature to 100 deg.C, preferably to 30-70 deg.C, subjected to ultrasonic cleaning and dried, or rinsed in water or warmed water and then dried. Or the plate is cleaned by spraying and then dried.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cleaning agent for ink attached to a screen printing plate. More specifically, it relates to a cleaning agent that exhibits an excellent cleaning effect by adding an alkaline component.

[0002]

2. Description of the Related Art Conventionally, chlorine-based solvents such as trichloroethane and dichloroethylene are used for cleaning to remove ink adhering to a screen printing plate. These chlorine-based solvents are cleaned depending on the type of ink adhered. It will not be usable in the future because it is regulated due to insufficient strength and environmental damage. Therefore, various alternative cleaning agents have been proposed in recent years, and one example is a cleaning agent in which an inorganic alkali is added to a solvent such as glycol ether.

[0003]

However, a cleaning agent prepared by adding an inorganic alkali to an organic solvent such as a glycol ether-based solvent has problems such as separation during heating and precipitation of the inorganic alkali in a concentrated solution. Have a point. An object of the present invention is to provide a cleaning agent for a screen printing plate which solves these problems, is excellent in cleaning power for various inks, and is satisfactory in environmental characteristics, toxicity, odor and the like.

[0004]

Means for Solving the Problems As a result of intensive studies conducted by the present inventors in order to achieve the above object, the use of quaternary ammonium hydroxide as an alkaline component in a cleaning agent meets this object. That is, the present invention has been completed. That is, the present invention is a cleaning agent for a screen printing plate containing quaternary ammonium hydroxide.

In the present invention, examples of the alkyl group having 1 to 6 carbon atoms of R _{1 to} R _{4 in} the general formula (1) of (A) include a methyl group, an ethyl group, a propyl group, a butyl group and an isopropyl group. And a tert-butyl group, a hexyl group and the like. Of these, preferred are alkyl groups having 1 to 4 carbon atoms, and particularly preferred are alkyl groups having 1 to 2 carbon atoms.

Specific examples of (A) include tetramethylammonium hydroxide, tetraethylammonium hydroxide,
Tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, trimethylethylammonium hydroxide, trimethylpropylammonium hydroxide, trimethylbutylammonium hydroxide, trimethylpentylammonium hydroxide, trimethylhexylammonium hydroxide, dimethyldiethylammonium hydroxide, hydroxide Methyltriethylammonium, a mixture thereof and the like can be mentioned.

In addition to the above-mentioned quaternary ammonium hydroxide as an alkaline component, the detergent composition of the present invention contains organic alkali such as alkanolamine, sodium hydroxide,
Inorganic alkalis such as potassium hydroxide, sodium carbonate and potassium carbonate can be added. In order to impart permeability and wettability, for example, ethylene oxide adducts of nonylphenol, ethylene oxide adducts of octylphenol, and surface active agents such as fluorochemical surfactants (eg, perfluoroalkylcarboxylic acid salts, perfluoroalkylethylene oxide adducts) Agents can be added. Preferred is a fluorosurfactant.

The cleaning agent of the present invention contains quaternary ammonium hydroxide as an essential component, but when the compound (B) represented by the following general formula (2) is used in combination, the cleaning effect is enhanced. preferable. R ₁ (C _n H _2n O) _m R ₂ (2) (In the formula, R ₁ is an alkyl group having 1 to 8 carbon atoms, R ₂ is hydrogen or an alkyl group having 1 to 8 carbon atoms, and n is 2 to 3 The integer of m
Represents an integer of 1 to 4. )

Examples of the alkyl group having 1 to 8 carbon atoms represented by R _{1 in} the general formula (2) of the compound (B) include methyl group, ethyl group, propyl group, butyl group, isopropyl group and te group.
Examples thereof include rt-butyl group, hexyl group, and octyl group. Among these, methyl group and ethyl group are preferable from the viewpoint of cleaning effect. If the number of carbon atoms in the alkyl group exceeds 8, detergency deteriorates. Examples of the alkyl group having 1 to 8 carbon atoms for R ₂ include a methyl group, an ethyl group, a propyl group, a butyl group, an isopropyl group and a tert-butyl group, a hexyl group, and an octyl group. Among R ₂ , preferred are hydrogen and an alkyl group having 1 to 4 carbon atoms, and hydrogen, a methyl group, and an ethyl group are particularly preferred because they exhibit an excellent cleaning effect. C8 alkyl group
If it exceeds the range, the detergency deteriorates. C _n H _2n O in the formula represents an oxyethylene group and / or oxypropylene groups. From the viewpoint of cleaning effect, it is preferable that at least an oxyethylene group is contained. m is ethylene oxide and /
Or the number of moles of propylene oxide added, usually 1
It is an integer of -4, preferably 2-3. When m exceeds 2, the addition form of ethylene oxide and / or propylene oxide may be single or may be random addition or block addition. If m exceeds 4, cleaning properties will be poor.

Specific examples of (B) include alkylene glycol monoalkyl ethers (diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monopropyl ether, diethylene glycol monobutyl ether, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, Triethylene glycol monopropyl ether, triethylene glycol monobutyl ether, ethylene propylene glycol monomethyl ether, ethylene propylene glycol monoethyl ether, ethylene propylene glycol monopropyl ether, ethylene propylene glycol monobutyl ether, diethylene propylene glycol monomethyl ether, diethylene Ropylene glycol monoethyl ether, diethylene propylene glycol monopropyl ether, diethylene propylene glycol monobutyl ether, triethylene propylene glycol monomethyl ether, triethylene propylene glycol monopropyl ether, triethylene propylene glycol monobutyl ether, tetraethylene propylene glycol monoethyl ether, ethylene Dipropylene glycol monomethyl ether, ethylene dipropylene glycol monoethyl ether, ethylene dipropylene glycol monopropyl ether, ethylene dipropylene glycol monobutyl ether, ethylene propylene glycol mono tert-butyl ether, dipropylene glycol monomethyl ether, dipropylene Glycol monoethyl ether, dipropylene glycol monobutyl ether, etc.), alkylene glycol dialkyl ethers (diethylene glycol dimethyl ether, diethylene glycol diethyl ether, triethylene glycol dimethyl ether, triethylene glycol diethyl ether, diethylene glycol methyl ethyl ether, etc.) and mixtures thereof. To be

The amount of quaternary ammonium hydroxide in the detergent of the present invention is usually 0.1 to 10% by weight, preferably 1 to 5%. Quaternary ammonium hydroxide is 0.1
If it is less than 10%, the detergency is insufficient, and if it exceeds 10%, it tends to precipitate as crystals.

To clean the screen printing plate with the cleaning agent of the present invention, the temperature is from room temperature to 100 ° C., preferably 30 to
After immersing in the cleaning agent of the present invention at 70 ° C. and washing with ultrasonic waves, the screen plate is pulled out and dried as it is, or rinsed with water or warm water and then dried. Further, the screen printing plate is sprayed with the cleaning agent of the present invention, washed, and then dried, or rinsed with water or warm water and then dried.

[0013]

【Example】
Hereinafter, the present invention will be described in detail with reference to Examples, but the present invention is not limited thereto. In the examples,% means% by weight unless otherwise specified.

A cleaning agent was prepared according to the following formulation. Example 1 Tetraethylammonium hydroxide 1% Diethylene glycol monobutyl ether 40% Water 59% Example 2 Tetraethylammonium hydroxide 2% Diethylene glycol monobutyl ether 40% Triethylene glycol diethyl ether 6% Water 52% Example 3 Tetraethylammonium hydroxide 2% Diethylene glycol monobutyl ether 10% Triethylene glycol diethyl ether 5% Water 83% Example 4 Tetraethylammonium hydroxide 5% Diethylene glycol monobutyl ether 60% Triethylene glycol diethyl ether 5% Water 30% Example 5 Tetraethylammonium hydroxide 1% Diethylene glycol diethyl Ether 80% Diethylene glycol monoethyl ether 8% Water 11%

Comparative Example 1 Methyltriethylammonium carbonate 1% Diethylene glycol monobutyl ether 40% Water 59% Comparative example 2 Sodium carbonate 2% Diethylene glycol monobutyl ether 10% Butyl cellosolve 5% Water 83% Comparative example 3 Sodium carbonate 2% Diethylene glycol monobutyl ether 40% Triethylene glycol diethyl ether 6% Water 52% Comparative example 4 1,1,1-trichloroethane 100% Comparative example 5 Hexaethylene glycol monomethyl ether 100%

<Cleanability Test> The following inks A to F were separately applied to a 250 mesh mesh polyester screen printing plate and air-dried at 25 ° C. for 30 minutes to give a contaminated plate. Ink A: Acrylic ink B: Polyester ink C: Epoxy ink D: Urethane ink E: Vinyl ink F: Acrylic Each of the cleaning agents of Examples 1 to 5 and Comparative Examples 1 to 5 was used. Ultrasonic cleaning was performed for 60 seconds at 40 ° C. in the agent, and the ink adhesion state of the screen plate was visually observed, and the following 5 grades were evaluated. The results are shown in Table 1. Evaluation criteria ◎: Ink completely washed ○: Ink remained very slightly △: Ink remained thin on the film form ×: A large amount of ink remained XX: No cleaning effect was observed

<Comparison of Stability> The cleaning agents of Examples 1 to 5 and Comparative Examples 1 to 5 were allowed to stand at 40 ° C. for 60 minutes and their external appearances were compared. The results are shown in Table 1. Evaluation criteria ○: No change in appearance, good stability ×: Separation occurred, poor stability

[0018]

[Table 1]

[0019]

The cleaning agent of the present invention contains quaternary ammonium hydroxide and is strong alkali, but does not have the problems such as poor stability found in conventional inorganic alkaline cleaning agents. In addition, regardless of the type of ink, it has the same or higher detergency as conventional chlorine-based cleaning agents, and because it is a non-chlorine-based cleaning agent, there is no risk of environmental damage, low toxicity, and sufficient odor. And is extremely useful as a cleaning agent for cleaning the ink attached to the screen printing plate.

Claims (2)

[Claims] 1. A cleaning agent for a screen printing plate containing quaternary ammonium hydroxide. 2. The cleaning agent according to claim 1, wherein the quaternary ammonium hydroxide is a compound (A) represented by the following general formula (1). General formula: (In the formula, R ₁ , R ₂ , R ₃ , and R ₄ represent an alkyl group having 1 to 6 carbon atoms.)