JPH0459898A - Detergent for flux - Google Patents

Abstract

PURPOSE:To provide the subject detergent containing a nonionic surfactant and a specified glycol ether-based compound as the essential components, and having detergency and finishing properties excellent enough to be substituted for chlorofluorocarbon 113 or methylchloroform. CONSTITUTION:An objective detergent containing (A) a polyoxyethylene-based nonionic surfactant, preferably composed of a polyoxyethlylene alkyl ether, a polyoxyethylene fatty acid ester, etc., preferably in an amount of 1-30wt.% and (B) a compound represented by the formula (n) is 1,2 or 3; (m) is 2 or 3; R1 is H or 1-5C alkyl or acetoxyl; R2 is H, 1-3C alkyl or acetyl), preferably in an amount of 50-99wt.% as the essential components.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a 7lux cleaning agent for removing flux applied during soldering to strengthen the bonding force between the solder and the base material after soldering. .

[Conventional technology]

Conventionally, in the field of electrical and electronic industries, flux is applied in advance in order to firmly bond solder and base material in the manufacturing process of printed circuits or printed wiring boards. If this flux remains on the printed circuit or printed wiring board, it will cause poor conductivity or corrosion. Therefore, after soldering is finished, it is usually cleaned and removed using an organic cleaning agent. Freon 113 or methyl chloroform has conventionally been used as this cleaning agent. These solvents have a great ability to dissolve flux and are nonflammable, so they are widely used.

[Problem that the invention is trying to solve]

However, as society's awareness of environmental issues increases, there is a movement to regulate the discharge of environmentally destructive substances into the atmosphere and water systems. For example, fluorocarbon solvents (5 types of specified fluorocarbons:
CFCl1, CFCl2, CFCll3, CFCll
The use of CFC115) and methyl chloroform is being restricted as they are ozone depleting substances.

Under such circumstances, industries that use Freon 113 or methyl chloroform are in need of a flux cleaning agent that can replace the solvent as soon as possible.

[Means to solve problems]

The present inventors have discovered that Freon 1 used in flux cleaning agents.
13 or as a result of repeated research on detergents to replace methyl chloroform, nonionic surfactants and the general formula (I) R, (OCm)n OR2(I) (where n is 1, 2 or 3) and when n is 1 or 2,
m is 2 or 3, R2 represents H1 an alkyl group having 1 to 5 carbon atoms or an acetoxyl group, and R2 represents H1 an alkyl group having 1 to 5 carbon atoms or an acetyl group.

Also, when n is 3, m is 2 or 3, R1 is H1 carbon number 1
-3 alkyl group or acetoxyl group, R2 is H
A composition containing as an essential component one or more substances represented by an alkyl group or an acetyl group having 1 to 3 carbon atoms is comparable to conventional flux cleaning agents (Freon 113 and methyl chloroform). We have discovered that this is a cleaning agent that exhibits moderately high cleaning performance and good finish, and based on this knowledge, we have developed the present invention.

That is, the present invention comprises (1) a nonionic surfactant, and (2) the general formula (
1) % formula %() (In the formula, n represents 1, 2 or 3, and when n is 1 or 2,
m is 2 or 3, R1 represents H1 an alkyl group having 1 to 5 carbon atoms or an acetoxyl group, and R2 represents H1 an alkyl group or acetyl group having 1 to 5 carbon atoms.

Also, when n is 3, m is 2 or 3, R1 is H1 carbon number 1
-3 alkyl group or acetoxyl group, R2 is H
This is a flux cleaning agent characterized by containing as an essential component one or more of the following substances (representing an alkyl group or acetyl group having 1 to 3 carbon atoms).

The concentration of the nonionic surfactant used in the present invention is 1 to 3.
Preferably, it is in the range of 0% by weight.

Examples of nonionic surfactants used in the present invention include polyoxyethylene alkyl ethers such as polyoxyethylene lauryl ether, polyoxyethylene cetyl ether, polyoxyethylene stearyl ether, and polyoxyethylene oleyl ether; polyoxyethylene nonylphenyl Ether, polyoxyethylene alkylphenyl ether such as polyoxyethylene octylphenyl ether; polyoxyethylene polyoxypropylene block polymer, polyoxysorbicun fatty acid ester, polyoxyethylene fatty acid ester, polyoxyethylene alkylamine, polyoxyethylene fatty acid Examples include polyoxyethylene derivatives such as amides; sorbitan fatty acid esters, glycerin fatty acid esters, and the like. Each of these can be used alone, but
Preferably, a combination of two or more types is used.

More preferably, a combination containing one or more polyoxyethylene-based nonionic surfactants such as polyoxyethylene alkyl ether or polyoxyethylene fatty acid ester is used. The number of moles of the ethylene oxide moiety added in the polyoxyethylene nonionic surfactant is preferably 3 to 40, more preferably 10 to 40.
It is 20.

General formula (I) used in the present invention R+ (OCm)n OR2(I) (wherein, n is 1
, 2 or 3, when n is 1 or 2, m is 2 or 3,
R1 represents an alkyl group or acetoxyl group in which H1 has 1 to 5 carbon atoms, and R2 represents an alkyl group or acetyl group in which H1 has 1 to 5 carbon atoms.

Also, when n is 3, m is 2 or 3, R3 is H1 carbon number 1
-3 alkyl group or acetoxyl group, R2 is H
The concentration of the substance represented by (representing an alkyl group or acetyl group having 1 to 3 carbon atoms) is preferably in the range of 50 to 99% by weight.

General formula (I) used in the present invention R+ (OCm)n OR2(I) (wherein, n represents 1.2 or 3, and when n is 1 or 2, m is 2 or 3,
R1 represents an alkyl group or acetoxyl group in which H1 has 1 to 5 carbon atoms, and R2 represents an alkyl group or acetyl group in which H1 has 1 to 5 carbon atoms.

Also, when n is 3, m is 2 or 3, R1 is H1 carbon number 1
~3 alkyl group or acetoxyl group, R2 is H1
Examples of substances represented by C1-C3 alkyl group or acetyl group include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol monomethyl ether, and diethylene glycol. Monoethyl ether, diethylene glycol dimethyl ether, diethyl glycol diethyl ether, ethylene glycol methyl ether acetate, ethylene glycol monoethyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, triethylene glycol monomethyl Examples include ether, dipropylene glycol monomethyl ether, tripropylene glycol monomethyl ether, and the like. These may be used alone or in combination of two or more.

The combination of essential components in the present invention can be arbitrarily changed depending on the material and form of the object to be washed, the type of dirt, etc. If any one of the essential components is missing, the finish will deteriorate due to poor flux cleaning performance or water rinsing performance. Moreover, only by combining two types of essential components can a practical cleaning agent that is safe for the environment and comparable in cleaning ability to conventional fluorocarbon-based and chlorine-based fluxes be obtained. Furthermore, various stabilizers and additives can be added to the composition of the present invention in order to maintain the safety of the liquid and improve the safety for the items to be washed, or to improve the dissolving power. Examples of stabilizers and additives include hydrocarbons, alcohols, ether acetals, esters, ketones, fatty acids, nitroalkanes, amines, amides, aminoethanols, benzotriazoles, etc. It will be done.

Furthermore, it is also possible to add an anionic surfactant or a cationic surfactant to the composition of the present invention, if necessary.

[Example] Hereinafter, the present invention will be specifically explained using Examples and Comparative Examples. The cleaning methods in Examples and Comparative Examples are as follows.

Cleaning method in one embodiment (Fig. 1) - Ultrasonic cleaning machine charged with the composition of the present invention [manufactured by Yamato Scientific, trade name: BRANSONC220] 2 tanks (first tank, second tank)
Two water rinsing tanks (a third tank and a fourth tank) were prepared, and the temperature of the washing tank was set to 40°C. In addition, the temperature of the water rinsing tank was set to room temperature.

■ Apply various types of flux (manufactured by Tamura Seisakusho, product name: Flux F-2) to the item to be washed (glass epoxy printed circuit board).
30V and MH-320■) and melted solder bath (
Soldering was performed at 260°C for 5 seconds.

■ The items to be washed were immersed in the first tank for 1 minute and then in the second tank for 1 minute to perform ultrasonic cleaning.

(2) Next, the items to be washed were sequentially immersed in the third tank and the fourth tank for 1 minute each, and the items to be washed were lightly shaken for water rinsing.

- Finally, the items to be washed were dried in a dryer set at 110°C (drying time: 5 minutes).

■ Ion residue on the printed circuit board was measured using an omega meter.

Cleaning method in a comparative example (Figure 2) - (when volatile solvent is used) ■ Three hard glass washers with a capacity of 1000 and equipped with cooling pipes (first tank, second tank, third tank) ), put 300 - of comparison solvent into each type, use the first tank as a boiling tank (at the boiling point of the comparison solvent), the second tank as a cooling tank (at room temperature), and the third tank as a steam tank (at the boiling point of the comparison solvent). temperature).

■ Each type of item to be washed was immersed in the bath for 1 minute in turn (however, in the third tank, the items to be washed were simply put into the steam layer).

■ Thereafter, the ion residue on the printed circuit board was measured using an omega meter.

Examples 1-8 A cleaning experiment was conducted on the compositions shown in Table 1.

The results are shown in Table 4.

Comparative examples 1 and 2 Cleaning experiments were conducted using the solvents shown in Table 2.

The results are shown in Table 4.

Comparative examples 3 to 6 Cleaning experiments were conducted using the solvents listed in Table 3.

The results are shown in Table 4.

〔Effect of the invention〕

The flux cleaning agent of the present invention has degreasing performance and finish quality comparable to conventional fluorocarbon-based and chlorinated solvents, and furthermore, it does not destroy ozone and is highly biodegradable, so it can be used in wastewater. Even if it gets mixed into the water, it can be easily decomposed by ordinary microbial treatment. Therefore, there is no need to worry about contaminating the aquatic environment due to wastewater. It is also a very safe cleaning solvent due to its low toxicity and high flash point.

Therefore, the flux cleaning agent of the present invention is practically an excellent degreasing agent that can replace conventional fluorocarbon-based and chlorinated solvents.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of a method of cleaning an object to be washed using a cleaning agent of an example, and FIG. 2 is a schematic diagram of a method of cleaning an object to be washed using a volatile solvent of a comparative example. Patent applicant: Asahi Kasei Industries, Ltd.

Claims (2)

[Claims] 1. (1) Nonionic surfactant, and (2) General formula (I) R_1-(O-Cm)n-O-R_2...(I) (In the formula, n represents 1, 2 or 3, and when n is 1 or 2, m is 2
Or 3, R_1 represents H, an alkyl group having 1 to 5 carbon atoms, or an acetoxyl group, and R_2 represents H, an alkyl group having 1 to 5 carbon atoms, or an acetyl group. Furthermore, when n is 3, m is 2 or 3, R_1 is H, an alkyl group having 1 to 3 carbon atoms, or an acetoxyl group, and R_2 is H, an alkyl group having 1 to 3 carbon atoms, or an acetyl group. A flux cleaning agent characterized by containing as an essential component one or more substances represented by: