JPH067610A - Solvent composition for removing stuck water - Google Patents

Abstract

PURPOSE:To provide a new solvent compsn. for removing stuck water having an ability of hydro-extraction for drying, not needing a post-treatment and having no fear of destracting the ozone stratosphere due to no chlorine contained therein, without losing desirable properties such as low toxicity, incombustibility, low corrosion, provided in chlorofluorocarbon series solvent compsn. such as CFC-113, etc. CONSTITUTION:This solvent compsn. for removing stuck water consists of a hydrofluorocarbon having the formula, CnHmF2n+2-m (4<=n<=6; 1<=m<=4) contg. dimethoxymethane therein.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is a solvent for removing adhered water for substituting solvent for drying after drying metal parts, plastic parts, glass parts, etc. It relates to a composition.

[0002]

2. Description of the Related Art Recently, in the production of precision metal parts, optical parts and electronic parts, the number of processes using water or washing with water is increasing, and it is necessary to remove the adhered water as a post-treatment of this process. is there. In order to remove this adhered water, it usually has excellent properties of low toxicity, noncombustibility, and low corrosiveness without invading the object to be treated, and also has a boiling point suitable for the process of removing adhered water, such as a surfactant or methanol. A chlorofluorocarbon-based solvent composition containing a lower alcohol such as
CFC-113: boiling point about 48 ° C) has been used.

However, the surfactant contained in the conventional solvent composition for removing adhered water tends to remain on the surface of the object to be treated even after this treatment step, and post-treatment or the like is required to remove it. There was a drawback that became. In addition, a composition mixed with alcohol cannot be used when the object to be treated is attacked by alcohol, and when the water removed from the object to be treated is removed from the solvent composition, the alcohol is easily extracted in water to control the liquid concentration. It took a lot of work.

From the perspective of ozone layer protection, CFC-11 (trichlorofluoromethane), CFC-12 (dichlorodifluoromethane) and CFC- are also used in Japan based on the Vienna Convention (1985) and the Montreal Protocol (1987). 113
The production volume of chlorofluorocarbons such as CFC-114, CFC-114 and CFC-115 are regulated and their use is regulated.

[0005]

DISCLOSURE OF THE INVENTION The present invention has a water displacement drying property without losing the low toxicity, nonflammability, and low corrosive properties of a chlorofluorocarbon solvent composition such as CFC-113, and a post-treatment. It is an object of the present invention to provide a novel solvent composition for removing adhered water, which does not require chlorine and does not contain chlorine and therefore does not damage the ozone layer.

[0006]

[Means for Solving the Problems]

The solvent composition for removing adhered water according to the present invention comprises
The hydrofluorocarbon represented by the general formula C _n H _m F _{2n + 2-m} (4 ≦ n ≦ 6; 1 ≦ m ≦ 4) contains dimethoxymethane.

Examples of the hydrofluorocarbon represented by the above general formula include octafluorobutane, nonafluoropentane, decafluoropentane, undecafluorohexane and dodecafluorohexane. More specifically, 1,1,2,2,3,3,4,4-octafluorobutane (C ₄ H ₂ F ₈ : HFC-338pcc), 1,1,1,2,4,4, 5,5,5 nonafluorobutyl pentane _{(C 5 H 3 F 9:} HFC-449mef), 1,1,1,3,4,4,5,
5,5-nonafluoropentane (C ₅ H ₃ F ₉ : HFC-449mfe),
1,1,1,2,3,4,4,5,5,5-decafluoropentane (C ₅ H ₂ F ₁₀ :
HFC-43-10mee), 1,1,1,2,2,3,3,4,4,6,6-undecafluorohexane (C ₆ H ₃ F ₁₁ : HFC-54-11pf), 1, 1,1,2,2,3,
3,4,4,6,6,6-dodecafluorohexane (C ₆ H ₂ F ₁₂ : HFC-53
-12 mf), etc., and also 2-trifluoromethyl-
1,1,1,4,4,5,5,5-octafluoropentane (C ₆ H ₃ F ₁₁ : HF
C-54-11mmzf) or 2-trifluoromethyl-1,1,1,3,4,4,5,
It may have a side chain group such as 5,5-nonafluoropentane (C ₆ H ₂ F ₁₂ : HFC-54-11 mmze).

The content of dimethoxymethane (CH ₃ OCH ₂ OCH ₃ : boiling point about 42 ° C.) is preferably 5 to 20% by weight, more preferably 8 to 16% by weight. If the content of dimethoxymethane is 20% by weight or more, the rubber or plastic of the composition may be affected or the flame retardancy may be lost. If it is 1% by weight or less, the compatibility with water is lowered and the effect of removing the adhered water is difficult to be exhibited.

In the solvent composition for removing adhered water of the present invention, the material to be treated is immersed in this to transfer the water adhering to the material to be treated to the solvent composition, and then the water content is changed by the difference in specific gravity. It is useful for a so-called displacement drying method in which the water to be adhered is removed from the object to be treated by floating and then the solvent composition is removed by drying the object to be treated at a temperature lower than that for removing the water.

The solvent composition for removing adhered water of the present invention may further contain at least one selected from nitroalkanes, epoxides, furans, benzotriazoles, phenols and amines as a stabilizer. Absent.
The amount used is usually preferably 0.1 to 5% by weight based on the solvent composition for removing adhered water of the present invention.

Specific applications of the solvent composition for removing adhered water of the present invention include washing metal parts, plastic parts, optical parts, etc. with water in the precision machinery industry, electronic industry, etc., and then heating the object to be treated to a high temperature. It is preferably used for drying by substituting the solvent for the water remaining without being deposited.

When used as a solvent for removing the adhered water as described above, methods such as dipping, submerged spraying and ultrasonic waves can be applied.

The present invention will be specifically described below with reference to examples.

[0015]

[Examples 1 to 5] 3 ml of pure water in a 25 ml graduated cylinder
And 0.4 mm glass beads were added up to the marked line of 8 ml. Then, a mixed composition of 90% by weight of hydrofluorocarbon shown in Table 1 and 10% by weight of dimethoxymethane as a solvent composition for removing adhered water was added up to the mark line of 25 ml. The amount of water floating above was measured 5 minutes after the start of the addition, and the ratio was defined as the dehydration rate. Table 1 shows the dehydration rate
Shown in.

Table 1 Example 1 HFC-338pcc (C ₄ H ₂ F ₈ ) / DMM = 90/10 27% Example 2 HFC-449mef (C ₅ H ₃ F ₉ ) / DMM = 90/10 26% Example 3 HFC-43-10mee (C ₅ H ₂ F ₁₀ ) / DMM = 90/10 24% Example 4 HFC-43-10mee (C ₅ H ₂ F ₁₀ ) / DMM = 95/57% Example 5 HFC-54-11pf (C ₆ H ₃ F ₁₁ ) / DMM = 90/10 30% Example 6 HFC-53-12mf (C ₆ H ₂ F ₁₂ ) / DMM = 90/10 27% Comparative example 1 HFC- 338pcc (C ₄ H ₂ F ₈ ) / DMM = 100/00% Comparative Example 2 HFC-449mef (C ₅ H ₃ F ₉ ) / DMM = 100/00% Comparative Example 3 HFC-43-10mee (C ₅ H ₂ F ₁₀ ) / DMM = 100/00% Comparative Example 4 HFC-54-11pf (C ₆ H ₃ F ₁₁ ) / DMM = 100/00% Comparative Example 5 HFC-53-12mf (C ₆ H ₂ F ₁₂ ) / DMM = 100/00%

[0017]

Comparative Examples 1 to 5 The same operation as in Example 1 was carried out without containing dimethoxymethane in the above hydrofluorocarbon. The results are shown in Table 1.

[0018]

Comparative Example 6 Same as Examples 1 to 5 using Freon (R) T-DFC (Mitsui-Dyupon Fluorochemical Co., Ltd.) which is a chlorofluorocarbon-based solvent composition containing a conventionally used surfactant. When the dehydration rate was measured by various operations, it was 30%.

[0019]

EFFECTS OF THE INVENTION The solvent composition for removing adhered water of the present invention has the ability of removing and displacing water from the object to be treated, as is clear from the examples, and has no residual surfactant so that the ozone layer does not remain. It has been used as an award since it does not adversely affect
The solvent composition for removing adhered water using CFC-113 or the like can be replaced.

Claims (3)

[Claims] 1. The general formula C _n H _m F _{2n + 2-m} (4 ≦ n ≦ 6; 1 ≦
A solvent composition for removing adhered water, which comprises dimethoxymethane in the hydrofluorocarbon represented by m ≦ 4). 2. The solvent composition for removing adhered water according to claim 1, wherein the content of dimethoxymethane is 5 to 20% by weight. 3. The solvent composition for removing adhered water according to claim 1, wherein the hydrofluorocarbon is at least one selected from octafluorobutane, nonafluoropentane, decafluoropentane, undecafluorohexane, and dodecafluorohexane.