EP1040179B1 - Compositions comprising perfluorobutyl methyl ether and use of said compositions - Google Patents

Abstract

Perfluorobutyl methyl ether forms azeotropic or pseudoazeotropic compositions with esters. These compositions can be used in particular as solvent for cleaning and defluxing electronic components, for degreasing metals, for removing water adsorbed at the surface of solids and for fixing a toner to a printing substrate.

Description

The invention relates to compositions comprising perfluorobutyl methyl ether (C ₄ F ₉ -O-CH ₃ ) and the use of these compositions, especially as a cleaning or drying agent for solid surfaces.

Fully halogenated chlorofluorocarbons (CFCs), particularly 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113), are widely used as solvents in industry for degreasing and surface cleaning various, particularly for solid parts of complicated shape and difficult to clean. In addition to their use in electronics, in the cleaning of solder flux to eliminate flux flux adhering to printed circuits, they are also conventionally used to degrease metal parts or to clean mechanical parts of high quality and high accuracy. In these various applications, CFC-113 is most often associated with other organic solvents, preferably in the form of azeotropic or pseudoazeotropic compositions having substantially the same composition in the vapor phase and in the liquid phase, so that they can be easily used at reflux.

Compositions based on CFC-113 are also conventionally used as a desiccant, in order to eliminate the water adsorbed on the surface of solid parts.

However, CFC-113, along with other fully halogenated chlorofluoroalkanes, is now suspected of being involved in the destruction of the stratospheric ozone layer.

As a result, there is currently an urgent need to find new compositions that do not adversely affect the ozone layer.

The hydrofluorinated chlorine-free compounds are completely inert with respect to the stratospheric ozone layer and there is an increasing use of these compounds in many applications to the detriment of compounds carrying chlorine atoms. .

For this purpose, the patent application WO 96/36689 provides azeotropic compositions of perfluorobutyl methyl ether with one or more organic solvents selected from linear or branched cyclic or acyclic alkanes comprising 6 to 8 carbon atoms, cyclic or acyclic ethers comprising 4 to 6 carbon atoms, ketones comprising 3 carbon atoms, chlorinated alkanes comprising 1.3 or 4 carbon atoms, chlorinated alkenes comprising 2 to 4 carbon atoms, 3 carbon atoms, alcohols comprising 1 to 4 carbon atoms, partially fluorinated alcohols comprising 2 to 3 carbon atoms, 1-bromopropane, acetonitrile, HCFC-225ea, and HCFC-225cb.

The document WO 96/22356 discloses compositions for cleaning and degreasing metal parts comprising mixtures based on alkoxy-substituted perfluorinated compounds and cosolvents, such as, in particular, the esters; the use of a mixture of perfluorobutyl methyl ether and methyl decanoate is specifically described therein.

The document WO 96/36688 discloses pseudo-azeotropic compositions based on perfluorobutyl ethyl ether and, inter alia, esters containing 4 carbon atoms, which can be used for the formulation of composition for surface coating.

The document WO 98/24003 prior art according to art. 54 (3) EPC discloses the use as a toner fixing agent for a recording medium of a mixture of perfluorobutyl methyl ether and 5% by weight of methyl acetate.

It is an object of the present invention to provide other compositions optionally forming azeotropes or pseudoazeotropes, which are particularly effective when used as a cleaning agent in solvent cleaning processes. The invention also relates to such compositions having properties particularly suitable for cleaning printed circuit boards. Another object of the invention is to provide such compositions devoid of destructive effect vis-à-vis the ozone layer.

The invention also relates to compositions having particularly suitable properties as a toner fixing agent to a recording medium in a printing apparatus or reproduction of documents.

The present invention therefore relates to azeotropic or pseudo-azeotropic compositions comprising at least one perfluorobutyl methyl ether of general formula C ₄ F ₉ -O-CH ₃ where C ₄ F ₉ is a linear or branched perfluorinated chain and at least one ester chosen of, methyl acetate, ethyl formate and methyl formate, said compositions containing about 21 to 52% by weight of methyl acetate or about 22 to 53% by weight of ethyl formate or about 40 to 92% by weight of methyl formate CF ₃ - (CF ₂ ) ₃ -O-CH ₃ , the (CF ₃ ) ₂ CF-CF ₂ -O-CH ₃ and mixtures thereof are the preferred perfluorobutyl methyl ethers. In the following description, the term "perfluorobutyl methyl ether" is used to designate a mixture of these 2 compounds, marketed by 3M under the name HFE-7100.

Basically, the thermodynamic state of a fluid is defined by four interdependent variables: pressure (P), temperature (T), composition the liquid phase (X) and the composition of the gas phase (Y). A true azeotrope is a particular 2 or more component system for which, at a given temperature and at a given pressure, the composition of the liquid phase X is exactly equal to the composition of the gas phase Y.
A pseudoazeotrope is a two or more component system for which, at a given temperature and at a given pressure, X is substantially equal to Y. In practice, this means that the constituents of such azeotropic and pseudo-azeotropic systems can not They can not be separated easily by distillation and therefore their composition remains substantially constant in the solvent cleaning operations, as well as in the recovery operations of solvents used by distillation.

For the purpose of the present invention, a pseudo-azeotropic mixture is understood to mean a mixture of two constituents whose boiling point (at a given pressure) differs from the boiling point of the true azeotrope of 0.5.degree. maximum. Mixtures whose boiling point differs from the boiling point of the true azeotrope of up to 0.2 ° C are preferred. Mixtures whose boiling point differs from the boiling point of the true azeotrope by up to 0.1 ° C are particularly preferred.

The contents of perfluorobutyl methyl ether and ester in the compositions according to the invention can vary widely, depending on the intended use.

Generally, the compositions according to the invention contain at least 1% by weight of perfluorobutyl methyl ether. They advantageously contain at least 5%. In a particularly preferred manner, they contain at least 10%. They can contain up to 99%. Most often, they contain at most 95%.

Particularly preferred compositions according to the invention are those which contain perfluorobutyl methyl ether and an ester in proportions in which they form a minimum boiling azeotrope or pseudoazeotrope.

The compositions of the azeotropic mixtures according to the invention were estimated on the basis of the results of the experimental measurements presented in the examples below.

Perfluorobutyl methyl ether and methyl acetate form a binary azeotrope or pseudo-azeotrope when their mixture contains about 21 to 52% by weight of methyl acetate. The binary compositions containing about 28 to 48% by weight of methyl acetate are preferred. Under a pressure of 102.3 kPa, the binary composition consisting essentially of about 61% by weight of perfluorobutyl methyl ether and about 39% by weight of methyl acetate constitutes a true azeotrope, whose boiling point is about 52.6 ° C. This composition is very particularly preferred.
Perfluorobutyl methyl ether and ethyl formate form a binary azeotrope or pseudoazeotrope when their mixture contains about 22 to 53% by weight of ethyl formate. Binary compositions containing about 26 to 46% by weight of ethyl formate are preferred. Under a pressure of 102.6 kPa, the binary composition consisting essentially of about 68% by weight of perfluorobutyl methyl ether and about 32% by weight of ethyl formate constitutes a true azeotrope, whose boiling point is about 50.2 ° C. This composition is very particularly preferred.

Perfluorobutyl methyl ether and methyl formate form a binary azeotrope or pseudoazeotrope when their mixture contains about 40 to 92% by weight of methyl formate. Binary compositions containing about 59 to 80% by weight of methyl formate are preferred. Under a pressure of 102.2 kPa, the binary composition consisting essentially of about 36% by weight of perfluorobutyl methyl ether and about 64% by weight of methyl formate constitutes a true azeotrope whose boiling point is about 31.2 ° C. This composition is very particularly preferred.

Various additives may optionally be present in the compositions according to the invention. The compositions according to the invention may thus contain stabilizers, surfactants or any other additives making it possible to improve the performance of the compositions according to the invention during their use. The nature and the quantity of these additives depend on the intended use and are easily defined by those skilled in the art. In general, the amount of additives present in the compositions according to the invention does not exceed about 20% of the weight of the composition, most often not more than 10%.

The compositions according to the invention have a boiling point suitable for replacing CFC-113-based compositions in existing cleaning apparatus. As regards its impact on the environment, perfluorobutyl methyl ether appears to be particularly interesting since it has a zero ozone destruction potential. The compositions according to the invention are further inert against the different types of surfaces to be treated, whether they are metal, plastic or glass.

The compositions according to the invention can therefore be used in the same applications and according to the same techniques as the prior compositions based on CFC-113. In particular, the compositions according to the invention can be used as a cleaning agent, solvent, degreasing agent, defluxant or desiccant.

The invention therefore also relates to the use of the compositions according to the invention as a cleaning agent, as a degreasing agent for solid surfaces, as a cleaning agent for printed circuit boards, contaminated with a stripping flux and residues thereof. as a desiccant to remove adsorbed water on the surface of solid objects.
The compositions according to the invention can also be used as a toner fixing agent for a recording medium in a printing or copying apparatus.

Perfluorobutyl methyl ether compositions useful as a toner fixing agent are compositions containing a C3-C6 hydrofluorocarbon. By C3-C6 hydrofluorocarbon is meant saturated hydrocarbons, aliphatic or alicyclic, consisting solely of carbon, fluorine and hydrogen, comprising from 3 to 6 carbon atoms, at least one fluorine atom and at least one atom hydrogen. Typical examples of C 3 -C 6 hydrofluorocarbons are hydrofluoroalkanes such as 1,1,1,3,3-pentafluoropropane (HFC-245fa), 1,1,1,3,3-pentafluorobutane (HFC-365mfc) and 1,1,1,2,2,3,4,6,6,6-decafluoropentane (HFC-43-10mee). 1,1,1,3,3-Pentafluorobutane is particularly suitable. Preferably, C3-C6 perfluorobutyl methyl ether / ester / hydrofluorocarbon terefinal compositions are used.

The invention therefore also relates to the use of the compositions according to the invention as a toner fixing agent to a recording medium in a printing device or reproduction of documents.

The following nonlimiting examples illustrate the invention in more detail.

Examples 1-3

In order to demonstrate the existence of azeotropic or pseudoazeotropic compositions according to the invention between perfluorobutyl methyl ether and an ester, a glass apparatus consisting of a 50 ml boiler flask surmounted by a reflux condenser was used. . The temperature of the liquid was measured by means of a thermometer immersed in the flask.

An accurately determined amount of perfluorobutyl methyl ether was heated under known pressure to boiling, and then small amounts of ester, accurately weighed, were gradually introduced into the vial by means of a syringe, via a syringe. lateral tubing.

The determination of the azeotropic composition was carried out by recording the evolution of the boiling point of the mixture as a function of its composition.

These measurements were made for mixtures containing perfluorobutyl methyl ether and increasing amounts of methyl acetate (Example 1), ethyl formate (Example 2) and methyl formate (Example 3).

The pressure at which the measurements were taken is mentioned. The results obtained are shown in Table I. Table 1 Example 1 Example 2 Example 3 Perfluorobutyl Methyl Ether / Methyl Acetate Composition Perfluorobutyl methyl ether / ethyl formate composition Perfluorobutyl Methyl Ether / Methyl Formate Composition (Pressure: 102.3 kPa) (Pressure: 102.6 kPa) (Pressure: 102.2 kPa) % by weight of methyl acetate T ° b (° C) % by weight of ethyl formate T ° b (° C) % by weight of methyl formate T ° b (° C) 0 60.2 0 60.2 0 60.2 1.86 58.8 1.98 58.2 0.92 57.2 2.78 58 3.40 56.8 4.49 49 3.76 57.6 4.96 55.6 7.08 44.4 4.88 56.8 6.83 54.6 8.95 42 7.29 55.6 9.26 53.4 18,55 35 9.69 54.8 12.16 52.4 22.91 33.8 13.72 53.8 13.95 52 34.50 32.4 16.74 53.4 16,07 51.6 39.66 31.8 19,03 53.3 18.74 51.2 45,22 31.6 21.44 53.1 22.24 50.8 51.69 31.4 24.26 53 26.47 50.4 63,96 31.2 33.96 52.8 31.44 50.2 79.91 31.3 39,11 52.6 40,10 50.4 87.66 31.4 44.32 52.7 49.47 50.6 90.82 31.6 48.58 52.8 54.13 50.8 93.31 31.8 52.68 53.2 67.56 51.2 95.47 32 79,09 52.2

Claims (9)

1. Azeotropic or pseudo-azeotropic composition comprising at least one perfluorobutyl methyl ether of formula C₄F₉-O-CH₃, in which C₄F₉ represents a linear or branched perfluorinated chain, and at least one ester, characterized in that the ester is chosen from methyl acetate, ethyl formate and methyl formate, said composition comprising approximately 21 to 52 % by weight of methyl acetate or approximately 22 to 53 % by weight of ethyl formate or approximately 40 to 92 % by weight of methyl formate.
2. Composition according to Claim 1, wherein the perfluorobutyl methyl ether is chosen from CF₃-(CF2)3-O-CH₃, (CF₃)₂CF-CF₂-O-CH₃ and their mixtures.
3. Composition according to Claim 1 or 2, comprising approximately 28 to 48 % by weight of methyl acetate or approximately 26 to 46 % by weight of ethyl formate or approximately 59 to 80 % by weight of methyl formate.
4. Minimum boiling point azeotropic composition according to Claim 1 or 2, composed of approximately 61 % by weight of perfluorobutyl methyl ether and of approximately 39 % by weight of methyl acetate, the boiling point of which is approximately 52.6°C under a pressure of 102.3 kPa.
5. Minimum boiling point azeotropic composition according to Claim 1 or 2, composed of approximately 68 % by weight of perfluorobutyl methyl ether and of approximately 32 % by weight of ethyl formate, the boiling point of which is approximately 50.2°C under a pressure of 102.6 kPa.
6. Minimum boiling point azeotropic composition according to Claim 1 or 2, composed of approximately 36 % by weight of perfluorobutyl methyl ether and of approximately 64 % by weight of methyl formate, the boiling point of which is approximately 31.2°C under a pressure of 102.2 kPa.
7. Use of the compositions according to any one of Claims 1 to 6 as cleaning agent, as agent for degreasing solid surfaces, as agent for cleaning printed circuit boards contaminated by a soldering flux and residues from this flux, or as drying agent for removing the water adsorbed at the surface of solid objects.
8. Composition according to any one of Claims 1 to 6, additionally comprising a C₃-C₆ hydrofluorocarbon.
9. Use of perfluorobutyl methyl ether, of the compositions comprising it and, in particular, of the compositions according to any one of Claims 1 to 6 and 8 as agent for fixing a toner to a recording substrate in a device for printing or reproducing documents.