JPH05124992A - Azeotropy-like composition - Google Patents

Abstract

PURPOSE:To obtain the subject composition comprising a highly brominated hydrocarbon as a base, having azeotropic behavior or a behavior close to azeotropic behavior and excellent characteristics as a detergent by blending decafluoropentane with 2,3-dimethylbutane. CONSTITUTION:70-99wt.1,% 1,1,2,3,4,4,5,5,5-decafluoropentane is mixed with 30-1wt.% 2,3-dimethylbutane and optionally a stabilizer such as a nitroalkane (preferably 0.05-0.5wt.%) to give the objective composition.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a highly fluorinated hydrofluorocarbon-based composition exhibiting azeotropic or similar behavior. More specifically, it is preferably used for degreasing and cleaning of grease and processing oil used for metal parts for processing and rust prevention, and flux removal during semiconductor manufacturing, as well as a foaming agent, working medium,
The present invention relates to an azeotropic composition capable of substituting for applications such as electrical insulating agents.

[0002]

BACKGROUND OF THE INVENTION Chlorofluorocarbons are widely used as solvents, foaming agents, refrigerants, etc. for cleaning semiconductor products such as flux removal, because chlorofluorocarbons are less toxic, flame retardant, and chemically and thermally stable. Is a chlorofluorocarbon-based solvent, 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113, boiling point about 48 ° C), or a chlorine-based solvent, 1,1,1-
Trichloroethane etc. were used.

[0003]

[Problems to be Solved by the Invention] However, from the perspective of protecting the ozone layer, CFC-11 (trichlorofluoromethane) and CFC-12 (dichlorodifluoromethane) are also used in Japan based on the Vienna Convention (1985) and the Montreal Protocol (1987). For chlorofluorocarbons such as methane), CFC-113, CFC-114, CFC-115, etc., production volume reduction and usage restrictions were implemented. In addition, it has been pointed out that the chlorine-based solvent is also carcinogenic, and there are problems such as groundwater pollution, and its use is being regulated. Therefore, the present invention aims to provide a composition which does not have a risk of depleting the ozone layer, does not have a problem of carcinogenicity, and is azeotropic or has a behavior close to that based on a novel chlorine-free hydrofluorocarbon. And

[0004]

The azeotrope-like composition according to the present invention comprises decafluoropentane and 2,3-dimethylbutane, especially 70 to 99% by weight of 1,1,1,2,3, 4,4,5,5,5-decafluoropentane (hereinafter referred to as HFC-43-10mee) and 30 to 1
It is characterized in that it consists of wt.% 2,3-dimethylbutane.

HFC-43-10mee used in the examples has a boiling point of 54.7
It was ℃. As 2,3-dimethylbutane, a commercially available solvent grade can be used.

When HFC-43-10mee having a boiling point of 54.7 ° C. is used,
The composition of the invention showed a minimum boiling point of 44.0 ° C. in a composition consisting of 84.6% by weight HFC-43-10mee and 15.4% by weight 2,3-dimethylbutane, as will be apparent from Example 1 below. .

Since the composition of the present invention is a composition that behaves azeotropically or behaves in a manner similar to that of the composition, the composition of the composition can be maintained in a small amount even if a distillation operation is carried out in the use process, so that the characteristics of the composition can be maintained. It is convenient for the recovery and reuse of substances, and the solubility of hydrocarbons is improved as compared with the case of decafluoropentane alone.

In the azeotrope-like composition of the present invention, nitroalkanes, epoxides, furans, which have been conventionally used as stabilizers for chlorofluorocarbons,
At least one selected from benzotriazoles, phenols, amines, and phosphates may be contained. The amount of stabilizer blended is based on the azeotropic composition
It is 0.01 to 5% by weight, preferably 0.05 to 0.5% by weight.

The flammability of the azeotropic composition of the present invention is 2,
Greatly increased against the flash point of 3-dimethylbutane alone,
Safety is improved. From the perspective of flammability, 2,3-
A composition containing 20% by weight or less of dimethylbutane is HFC-43-10m
It is desirable because the dilution effect of ee can be expected.

Specifically, as a cleaning agent application, a cleaning agent for metal parts, plastic parts, rubber products, precision machine parts and electronic parts combining these parts for removing contaminants such as flux, oil and buffing agent. Also used as a cleaning agent for dry cleaning. When used as a cleaning agent, wipe with normal temperature cleaning method, dip, brush wash,
Flashing, spraying, ultrasonic cleaning, immersion in a boiling state by a heating cleaning method, steam rinsing, steam cleaning, etc. can be applied, and it is more effective to combine them.

The azeotrope-like composition of the present invention can be used for various purposes such as a foaming agent, a working medium, a solvent for fluoropolymer polymerization, an electric insulating agent, etc., as well as a conventional CFC.

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

[0013]

Example 1 HFC-43-10mee (boiling point 54.7 ° C.) 90% by weight and
2,3-Dimethylbutane (Wako Pure Chemical Industries: Boiling point: 58 ℃) 10% by weight
400 g of a mixed solution containing the above was placed in a flask (500 ml), and distillation was performed under atmospheric pressure at a reflux ratio of 50 using an Oldershaw type distillation column having 30 theoretical plates. As a result, the column top temperature corresponds to about 33% of the initial weight at a constant temperature of 44.0 ° C. 13
2 g of distillate could be obtained. The azeotrope-like fraction at this constant temperature of 44.0 ° C was analyzed by gas chromatography (GC-14A manufactured by Shimadzu Corporation).
The composition was 84.6% by weight of -10mee and 15.4% by weight of 2,3-dimethylbutane.

[0014]

[Example 2] HFC-43-10mee8.46 in a sample bottle (20 ml)
g and 1.54 g of 2,3-dimethylbutane and mixed at room temperature,
Refrigerating machine oil (Atmos HAB15F: made by Nippon Oil) 0.1
g was added, and the mixture was shaken by hand at room temperature and stirred. Refrigerating machine oil was uniformly dissolved in the mixed composition.

[0015]

Example 3 85% by weight of HFC-43-10mee and 15% by weight of 2,3-
The composition of dimethylbutane was measured according to JIS: K-2265. The flash point of this composition was found to be significantly higher than that of a single 2,3-dimethylbutane product.

[0016]

[Comparative Example 1] HFC-43-10mee was added to a sample bottle (20 ml).
10 g was weighed, and 0.1 g of the same refrigerating machine oil used in Example 2 was placed therein, and the mixture was shaken by hand at room temperature and stirred, and after standing, two layers were separated. Solubility in oils and fats is HFC-43-1
The azeotrope-like composition of the present invention is clearly superior to 0mee alone.

[0017]

The composition of the present invention (minimum boiling point 44.0 ° C.) is
As is clear from the examples, the boiling point is close to that of CFC-113 (boiling point: about 48 ° C.), the conventional equipment can be used as it is, and the behavior is azeotropic or close to it, so that liquid management is easy. Further, since it has a higher solubility in oils and fats than HFC-43-10mee alone, it is useful for degreasing and cleaning grease and processing oils used for metal parts for processing and rust prevention, and flux removal during semiconductor manufacturing.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location C23G 5/028 7308-4K // H05K 3/26 6736-4E

Claims (2)

[Claims] 1. An azeotropic composition comprising decafluoropentane and 2,3-dimethylbutane. 2. A method comprising 70 to 99% by weight of 1,1,1,2,3,4,4,5,5,5-decafluoropentane and 30 to 1% by weight of 2,3-dimethylbutane. Item 1. The azeotropic-like composition according to item 1.