JPH07266028A - Cleaning liquid composition for soldering flux - Google Patents

Abstract

(57) [Summary] [Purpose] In addition to having a good cleaning effect, it can be sufficiently dried without rinsing the object to be cleaned and at a low temperature for a short time, and is free from stains such as scale. Provided is a cleaning liquid composition for soldering flux, which also has safety. [Structure] (A) N-methyl-2-pyrrolidone, (B)
Water, and (C) 3-methoxy-3-methylbutanol,
A cleaning liquid composition for a soldering flux containing at least one compound selected from 2-ethoxyethanol, 2-methoxyethanol acetate and 1-methoxy-2-propanol acetate.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cleaning liquid composition suitable for cleaning soldering flux adhered to a printed wiring board or electronic parts.

[0002]

2. Description of the Related Art Conventionally, fluorocarbon solvents and chlorine solvents have been used for cleaning soldering flux, but these solvents are substances that destroy the ozone layer, and their production is banned in the near future. In addition, chlorine-based solvents are highly toxic and prevent water pollution, so their regulations are strict.

Petroleum-based solvents such as hydrocarbons, terpene-based solvents, alcohol-based solvents, acetone and the like can be used, but these solvents have poor detergency against inorganic ions and polar compounds, and their flash points. Is relatively low and has toxicity and other safety problems.

Aqueous detergents containing surfactants and inorganic alkalis, and aqueous solutions such as phosphates have poor detergency,
Moreover, a large space is required for the wastewater treatment facility, which is not preferable from the economical aspect. In addition, there is also a problem that after the cleaning, a rinsing step is required to remove scales, additive components, etc. that cause stains.

Japanese Unexamined Patent Publication No. 4-68095 discloses (1)
A flux detergent containing a nonionic surfactant and (2) one or more selected from N-methylpyrrolidone, 2-pyrrolidone, γ-butyrolactone, dimethylsulfoxide, sulfolane, and propylene carbonate is disclosed. . However, there is a problem that a rinsing step is required as in the above.

Japanese Unexamined Patent Publication (Kokai) No. 3-243698 is effective for removing flux residues containing tetrahydrofurfuryl alcohol and pyrrolidone substituted with C ₁ -C ₆ alkyl or C ₁ -C ₆ alkenyl. Detergents are disclosed. However, in the detergent,
Further, there is a problem that a step of washing with a washing solvent such as water, alcohol or fluorinated hydrocarbon is required.

US Pat. No. 4,983,224 discloses a cleaning liquid composition containing a terpene / terpenol, a surfactant, N-methylpyrrolidone and optionally water.
A method of cleaning the soldering flux is disclosed. However, there is a problem that it is preferable to finally perform water washing.

Further, the present applicant has already applied for a cleaning liquid composition containing 70 to 85 parts by weight of N-methyl-2-pyrrolidone and 30 to 15 parts by weight of water, which is a good cleaning liquid for soldering flux (Japanese Patent Application No. Hei 10 (1999) -135242). 5-208490).

[0009]

The present invention has a good cleaning effect and can be sufficiently dried without rinsing the object to be cleaned and at a low temperature for a short time, and stains such as scales can be removed. The present invention provides a cleaning liquid composition for soldering flux, which does not exist and also has excellent safety.

[0010]

The present invention provides (1)
(A) N-methyl-2-pyrrolidone, (B) water, and (C) 3-methoxy-3-methylbutanol, 2-ethoxyethanol, 2-methoxyethanol acetate and 1-methoxy-2-propanol A cleaning liquid composition for a soldering flux containing at least one compound selected from acetic acid ester.

In a preferred embodiment, (2) (A) 20
To 72 parts by weight, (B) 18 to 50 parts by weight, and (C) 1
The cleaning liquid composition for soldering flux according to (1) above, which contains 0 to 45 parts by weight, and the total of these is 100 parts by weight, and (3) (C) is 3-methoxy-3-methylbutanol. 1) or the cleaning solution composition for soldering flux according to (2), (4) (A) N-methyl-
2-pyrrolidone 40-60 parts by weight, (B) water 20-
25 parts by weight and 20 to 40 parts by weight of (C) 3-methoxy-3-methylbutanol, the total amount of which is 10
0 parts by weight of a soldering flux cleaning liquid composition,
Etc. can be mentioned.

The cleaning liquid composition of the present invention has a good cleaning effect and a good drying property at low temperature. Therefore, even if the rinsing step is omitted or greatly simplified, the object to be cleaned can be easily dried. In addition, no scale remains on the surface of the object to be cleaned, and wastewater treatment is easy. Furthermore, the cleaning liquid composition of the present invention has low flammability and is very excellent in terms of safety. In addition, since the organic compounds such as N-methyl-2-pyrrolidone contained in the cleaning liquid composition have a high boiling point, there is little loss due to evaporation, and they can be reused by distillation, which is also economically advantageous. .

In the cleaning liquid composition for soldering flux of the present invention, (A) N-methyl-2-pyrrolidone (hereinafter sometimes abbreviated as NMP), (B) water, and (C)
3-methoxy-3-methylbutanol (hereinafter sometimes abbreviated as MMB) 2-ethoxyethanol (hereinafter E
EO), 2-methoxyethanol acetate (hereinafter sometimes abbreviated as MEA) and 1-
Acetate of methoxy-2-propanol (hereinafter M
The compounding ratio of at least one compound selected from (may be abbreviated as PA) is preferably 20 to 72 parts by weight of (A),
(B) 18 to 50 parts by weight, and (C) 10 to 45 parts by weight, and the total of these is 100 parts by weight. here,
As (C), MMB is preferably used. (C)
When MMB is used as the composition, the compounding ratio of (A), (B) and (C) is 40 to 60 parts by weight of (A), (B) 2
0 to 25 parts by weight, and (C) 20 to 40 parts by weight,
It is particularly preferred that the total of these is 100 parts by weight. When the compounding ratio of (A), (B) and (C) is within the above range, the cleaning liquid composition has excellent cleaning power and dryness, and JIS K2274 using a Cleveland open type flash point measuring device. When the flash point is measured according to the method, it exhibits substantially no flammability, which is preferable.

When (A) is less than the above range, the detergency of the cleaning liquid composition is deteriorated. When (A) exceeds the above range, the drying property at low temperature is deteriorated and the risk of ignition occurs, which is not preferable in terms of safety. If the content of (B) is less than the above range, the cleaning liquid composition causes a risk of ignition.
When (B) exceeds the above range, the detergency of the cleaning liquid composition is deteriorated. Further, when (C) is less than the above range, the drying property at low temperature is deteriorated, and when (C) exceeds the above range, there is a risk of ignition, which is not preferable in terms of safety.

In the cleaning liquid composition of the present invention, a surfactant, an antioxidant, and
Conventional additives such as ultraviolet absorbers and rust preventives may be included. Here, the surfactant as an optional substance is used for improving the permeability to the soldering flux and the dissolution rate. The surfactant is preferably a nonionic surfactant, for example, higher alcohol ethylene oxide adduct, alkylphenol ethylene oxide adduct, fatty acid ethylene oxide adduct, higher alkylamine ethylene oxide adduct, sorbitol and sorbitan fatty acid ester, Any of sucrose fatty acid ester, silicon type, fluorine type and the like can be used. Also,
Other optional substances such as UV absorbers and antioxidants help improve stability for long-term storage of liquids, and as UV absorbers, for example, benzotriazole-based, benzophenone-based, hindered amine-based, etc. can be used, and As the inhibitor, for example, any of those that are soluble in the cleaning liquid composition of the present invention, such as phenol-based, amine-based, sulfur-based, and phosphorus-based, can be used.

The method for producing the cleaning liquid composition of the present invention is not particularly limited, and commonly known means can be adopted, and the components can be produced by mixing them in any order.

The washing method itself with the washing liquid composition of the present invention is not particularly limited, and any known method can be used.
For example, it is preferable to carry out by wiping with a sponge impregnated with the cleaning liquid composition, dipping in the cleaning liquid composition and / or spraying. In the cleaning by immersion, it is more preferable to combine stirring, shaking, ultrasonic waves, air bubbling and the like at the same time in order to enhance the cleaning effect. In this case, it is preferable that the ultrasonic wave is used under an oscillation frequency of 20 to 100 kHz and an oscillation output of 10 to 200 W / l. In air bubbling, fine air bubbles are preferably aerated at a gas: liquid volume ratio of about 1: 1 to 5: 1 to raise insoluble dirt in the cleaning liquid composition together with the air bubbles and also separate insoluble dirt. can do.
In cleaning by spraying, the pressure is, for example, 0.
5 to 10 kg / cm ² G is preferable. In any case, the cleaning time is preferably 15 seconds to 2 hours, particularly preferably 30 seconds to 20 minutes. If the amount is less than the above range, the cleaning is insufficient and the attached dirt cannot be sufficiently removed. On the other hand, if the amount exceeds the above range, the cleaning effect is not particularly improved. The washing temperature is preferably 20 to 80 ° C. Particularly preferably 4
It is 0 to 60 ° C., and the cleaning effect can be remarkably increased by treating at a high temperature. Below the above range,
Washing tends to be insufficient. Exceeding the above range is not preferable because the electronic components installed on the substrate are likely to deteriorate, and the evaporation rate of water is large, and the control of the water concentration of the cleaning liquid composition is complicated.

In order to control the water content of the cleaning liquid composition of the present invention, for example, a gravimetric method by distillation separation described in ASTM D95-83, ASTM E203-7.
The titration method using the Karl Fischer reagent described in 5 above, quantification by near-infrared spectroscopy, quantification using refractive index, or the like can be used.

The object to be cleaned, which has been cleaned using the cleaning liquid composition of the present invention, can be dried by a generally known method. For example, it is possible to easily dry the printed wiring board after washing by blowing hot air. The temperature of the warm air is preferably 30 to 70 ° C, and the drying time is preferably 5 to 15 minutes.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples.

[0021]

EXAMPLES In the Examples and Comparative Examples, the following soldering flux, and the water-based cleaning liquid and the petroleum-based cleaning liquid as the cleaning liquid for comparison were used. <Soldering Flux> ・ Rosin type: Sparkle flux PO-F-1010
S (Trademark, manufactured by Senju Metal Industry Co., Ltd.) ・ Water solubility: Sparkle Flux WF-2060 (trademark, manufactured by Senju Metal Industry Co., Ltd.) <Comparative cleaning liquid> ・ Water-based cleaning liquid: Toyosol SS-20 (trademark, Toyota Chemical Co., Ltd.) 5% by weight aqueous solution of water) Petroleum-based cleaning liquid: ACTREL 1178L (trademark, manufactured by Exxon Chemical Co., Ltd.)

[0022]

Examples 1 to 6 and Comparative Examples 1 and 2 Ultrasonic Cleaning Test 5 cm × 7 cm 100 mesh stainless steel wire mesh was dipped in each of the above soldering fluxes and then pulled up.
The solution was drained by leaving it on a metal bat lined with filter paper at room temperature for 1 hour, and the weight of each soldering flux attached to the wire net was measured. Next, in a 150 ml sample bottle, 100 ml of the wire mesh and the cleaning liquid composition to which each of the soldering fluxes described above was attached was placed in an ultrasonic cleaner (oscillation frequency 28 kHz, oscillation output 80 W /
Washing was carried out for 30 seconds at 40 ° C. with 1). The cleaning liquid compositions used are as shown in Table 1. After washing
The wire net was taken out, dried at 90 ° C. for 30 minutes, allowed to cool at room temperature for 30 minutes, and then weighed to determine the removal rate of each soldering flux. The results are shown in Table 1.

[0023]

[Table 1] In Examples 1 to 4, (A), (B) and (C) were used at the same mixing ratio, respectively, and the type of the component (C) was changed, and the water-soluble soldering flux was washed and removed. Regardless of the type of component (C), the removal rate of the water-soluble soldering flux was extremely good in all cases. Example 5 is
Compared with Example 1, the blending amount of water was decreased and the blending amount of MMB was increased. The removal rate of the water-soluble soldering flux was remarkably good as in Example 1.
In Example 6, the cleaning liquid composition having the same composition as in Example 1 was used to clean and remove the rosin-based soldering flux. The removal rate was remarkably good regardless of the type of soldering flux.

On the other hand, in Comparative Examples 1 and 2, the rosin-based soldering flux was cleaned and removed using an aqueous cleaning solution or a petroleum-based cleaning solution, respectively. The removal rate of each of them is remarkably poor as compared with Example 6.

[0025]

Examples 7 to 11 and Comparative Examples 3 and 4 Cleaning Test by Swinging The above-mentioned soldering flux was applied to each dot printed circuit board of 4 cm × 6 cm, and then left for 5 minutes. next,
After drying at 90 ° C. for 10 minutes using a hot air circulation oven, the weight of the soldering flux attached to each substrate was measured. Next, 500 ml of each cleaning liquid composition shown in Table 2 was placed with the substrate to which the soldering flux adhered in a direction in which the substrate surface was perpendicular to the liquid surface. Then amplitude 2
It was washed by rocking vertically at 20 ° C. for 10 minutes at a rate of 5 mm and 50 cycles per minute. After washing
The substrate was taken out, dried at 90 ° C. for 30 minutes, then allowed to cool at room temperature for 30 minutes, and then weighed to determine the soldering flux removal rate. The results are shown in Table 2.
Shown in.

[0026]

[Table 2] In Examples 7, 8 and 9, the cleaning liquid composition of the present invention was used to clean and remove the rosin-based soldering flux. In Comparative Examples 3 and 4, the rosin-based soldering flux was cleaned and removed using a cleaning liquid composition containing water and MMB or NMP and water. Examples 7, 8 and 9 are compared with Comparative Examples 3 and 4,
The removal rates were all better. Example 8 is the same as Example 7 in that the blending amount of water is constant, the blending amount of NMP is decreased, and the blending amount of MMB is increased. Although the removal rate of Example 8 is slightly lower than that of Example 7,
The effects of the present invention can be sufficiently achieved. Example 9 is the same as Example 8 except that Component (C) was added from MMB to MEA.
It has been changed to. Example 9 is different from Example 8 in that
Almost the same removal rate was obtained. Examples 10 and 11
In both cases, the water-soluble soldering flux was washed and removed. The removal rate of the water-soluble soldering flux was extremely good. Further, when the NMP content was reduced and the MMB content was increased, the removal rate tended to decrease somewhat.

[0027]

Examples 12 to 18 and Comparative Examples 5 to 14 Dryability Test As the article to be cleaned, a mounting board used in a Sartorius electronic balance was cut into about 8 cm × 4 cm. Two ICs, 18 resistors, and 2 sockets were installed on the object to be cleaned. The article to be cleaned was previously dried with hot air at 80 ° C. for 30 minutes with hot air. Next, the article to be cleaned is dipped in each cleaning solution composition shown in Table 3 heated to 50 ° C., and an ultrasonic cleaner (oscillation frequency 28 kHz) is used.
z, oscillation output 80 W / l) for 3 minutes. After that, the solution was drained at room temperature for 1 minute and dried with hot air at 50 ° C. for 9 minutes using a hot dryer. Then, the dry state was visually evaluated.

The evaluation results are shown in Table 3.

[0029]

[Table 3] Here, the symbols in Table 3 indicate the following contents. ○: Even if filter paper is inserted into the gap of the socket of the object to be washed,
The liquid is not absorbed by the filter paper because there is no liquid Δ: No droplet is observed on the appearance of the object to be cleaned, but the liquid is absorbed by the filter paper when the filter paper is inserted into the gap of the socket, etc. A state in which droplets are visually observed in a gap or the like of the washed product. In Examples 12 to 15, (A), (B), and (C) have the same mixing ratio, and the drying time is 12 minutes. The type of C) is changed. The dry conditions were all good. Example 16 is different from Example 12 in N
The amount of MMB is reduced while the amount of MP is fixed, and the amount of water is increased. Even if the drying time was shortened to 10 minutes, a good dried state was obtained. Example 17 is
As compared with Example 12, the amount of MMB was reduced and the amount of NMP was increased while the amount of water was kept constant. As in Example 12, a good dry state was obtained after a drying time of 12 minutes. In addition, in Example 18, the drying time was shortened to 9 minutes as compared with Example 13. Although the dry state was slightly lowered, the effects of the present invention could be sufficiently achieved. Thus, the cleaning liquid composition of the present invention shows a good dry state. On the other hand, Comparative Examples 5 to 8 use cleaning liquid compositions composed of NMP and water. NMP
When the compounding ratio of is reduced to 20 parts by weight, the dry state is improved. However, the cleaning effect is remarkably reduced and it is not practical. Comparative Examples 9 to 14 use cleaning liquid compositions containing the component (C) and water. All showed almost good dry conditions. However, as shown in Comparative Example 3, for example, the cleaning effect is extremely low and not suitable.

[0030]

EFFECTS OF THE INVENTION The cleaning liquid composition of the present invention has a good cleaning effect and can be sufficiently dried without rinsing an object to be cleaned and at a low temperature for a short time, and stains such as scales can be removed. It also has excellent safety. It is also economically superior. Therefore, it is industrially extremely useful as a substitute for the conventional cleaning liquid.

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Claims (1)

[Claims] 1. (A) N-methyl-2-pyrrolidone,
(B) water, and (C) at least one compound selected from 3-methoxy-3-methylbutanol, 2-ethoxyethanol, acetic acid ester of 2-methoxyethanol and acetic acid ester of 1-methoxy-2-propanol. A cleaning liquid composition for soldering flux containing.