WO2008095879A1

WO2008095879A1 - Method of handling compositions comprising pentafluorobutane

Info

Publication number: WO2008095879A1
Application number: PCT/EP2008/051305
Authority: WO
Inventors: Michael Marhold; Helge Rau; Karsten K. BÖRNER; Christoph Meurer
Original assignee: Solvay Fluor Gmbh
Priority date: 2007-02-06
Filing date: 2008-02-04
Publication date: 2008-08-14
Also published as: TW200835668A

Abstract

A method of using a nonflammable composition comprising 1,1,1,3,3-pentafluorobutane and trans-1,2-dichloroethylene which comprises at least one step wherein said composition is not handled under conditions required for handling of flammable products.

Description

Method of handling compositions comprising pentafluorobutane

The invention relates to a method of handling compositions comprising pentafluorobutane, especially in liquid or vapour form, for example, as solvent, as refrigerant, as propellant/solvent for sprayable compositions or as cleaning and/or drying agents for solid surfaces, e.g. for defluxing of electronic parts or for degreasing of metals, or for fixing a toner in a document, printer or copier.

Fully halogenated chlorofluorinated hydrocarbons (CFCs), in particular l,l,2-trichloro-l,2,2-trifluoroethane (CFC-113), were widely used as solvents in industry for degreasing and cleaning various surfaces, particularly for solid components of complicated shape which are difficult to clean. In addition to their use in electronics in cleaning soldering fluxes in order to remove the pickling flux which adheres to printed circuits, they were also conventionally used for degreasing metal components or for cleaning mechanical components of high quality and of high precision. In these various applications, CFC-113 was most often used in combination with other organic solvents, preferably in the form of azeotropic or pseudoazeotropic compositions having substantially the same composition in the vapour phase and in the liquid phase, so that they can be easily employed at reflux.

Compositions based on CFC-113 were also conventionally used as desiccating agents, in order to remove the water adsorbed at the surface of solid components.

However, CFC-113, as well as other fully halogenated chlorofluoroalkanes, is today suspected of being involved in the destruction of the stratospheric ozone layer, and consequently, alternatives had to be identified. Very often, these alternatives are based on hydrofluorocarbons. Such compounds which consist of carbon, hydrogen and fluorine atoms are ozone-friendly. Among these compounds, 1,1,1,3,3-pentafluorobutane (HFC-365mfc) was identified as especially useful compound. It can be used, for example, as a solvent, as a blowing agent for production of foams, or as refrigerant. It can also be used for cleaning surfaces, for example. EP patent application EP-A-O 653484 discloses compositions comprising

1,1,1,3,3-pentafluorobutane, trans- 1,2-dichloroethylene and optionally an alcohol with 1 to 3 carbon atoms. Both trans- 1,2-dichloroethylene and alcohols with 1 to 3 carbon atoms are, per se, flammable.

US patent 5,714,298 discloses toner fixing agents containing HFC-365mfc and, i.a., trans- 1,2-dichloroethylene. It is stated in table II of that patent that a mixture consisting of 70 % by weight of HFC-365mfc and 30 % by weight of trans- 1,2-dichloroethylene, has no closed cup flash point in the range of - 3O⁰C to

+ 4O⁰C. Consequently, that statement made in 1996 does not exclude the possibility that a flash point exists at a higher temperature than that tested in that example; especially if it is taken into consideration that, while at that time it was believed that HFC-365mfc was non-flammable, it was later considered flammable

(see, for example, US 6080799) even though HFC-365mfc can be ignited only with difficulty because it needs a high ignition energy.

EP-A-O 618288 discloses compositions comprising HFC-365mfc and ethanol which are suitable as cleaning or degreasing agents. It would be very advantageous if 1 , 1 , 1 ,3 ,3-pentafluorobutane, in at least one step during its use, would not need to be handled under conditions required for handling of flammable products.

The present invention provides such a method. The inventive method of using a non-flammable composition comprising 1,1,1,3,3-pentafluorobutane and trans- 1,2-dichloroethylene (TDCE) comprises at least one step wherein said composition is not handled under conditions required for handling of flammable products.

The terms "comprising" and "containing" in the context of the present invention include the meaning "consisting of. In a preferred embodiment, no fluorinated saturated or unsaturated ether, for example, nonfluoromethoxybutane, methylene chloride or

1,1,1,2,3,4,4,5,5,5-decafluoropentane is comprised in the composition. In another preferred embodiment, 1,1,1,3,3-pentafluorobutane is the only hydrofluorocarbon present in the composition. The term "step" in the present invention preferably denotes a distinct step after the mixing of HFC-365mfc and TDCE (optionally also with stabilizers) and disposal of its composition with TDCE. Of course, the method of the invention includes two or more or even substantially all steps wherein said composition is not handled under conditions required for handling of flammable products. A step according to the present invention is, for example, the transfer of the composition after its mixing into containers for transport or storage, possible steps of its purification (e.g. in a reuse concept), opening containers as a first step in transferring the composition completely or a part of it to or into other containers, to a point of use or to take test samples, applying the composition to treat articles, or recollecting the composition after its use.

The term "flammable" is meant to denote any flammability determined according to any applicable standard, for example, ASTM D93-94 according to Pensky-Martens (closed cup test), JIS K2265-1996 and preferably as defined in DIN/EN/ISO 13736. Flammability is the ability of a substance to form a mixture in air under conditions which in presence of an ignition source can undergo a self -propagating reaction. The "conditions" preferably go according to the national or supranational regulations, e.g. the regulations of the European Union, which concern the protection against hazards of flammable compounds or compositions. For example, Directive 67/548/EWG comprises in two annexes (Annex III, "Nature of special risks attributed to dangerous substances and preparations; in German shortly called "R-Satze" = R-phrases; and Annex IV, "Safety advice concerning dangerous substances and preparations"; in German shortly called "S-Satze" = S- phrases). These conditions are known to the expert in this field. These measures convey technical instructions to person using the composition handle them in a way allowing to prevent or at least to reduce fire risks and to reduce explosion hazards and measures intended to warn the public against a potential hazard of flammability which are omitted in at least one step of handling the composition of HFC-365mfc and TDCE.

Typical examples are Risk Advice R7 "May cause fire", Risk Advice R 8 "Contact with combustible material may cause fire", RlO "Flammable", R 18 "In use, may form flammable/explosive vapour-air mixture", or Safety Advices S 6.2 "Keep under Argon", S 6.2 "Keep under nitrogen", S 14 "Keep away from flammable organic compounds", S 16 "Keep away from sources of ignition - no smoking", S 17 "Keep away from combustible material".

Thus, the process of the present invention includes preferably one step which is performed not according to the Safety Advices concerning flammability of compounds and compositions, especially at least one of those mentioned above. Specific measures concern, for example, labelling containers to contain a flammable product, for example, during the step of transporting the composition or during the step of storing the composition, especially by Risk Advices given above which can be omitted since the compositions are non-flammable. The term

"labelling" is intended to include labels attached directly on the container, but also - A -

labels attached to the transport means for such containers, e.g. road tankers or railway wagons. The term "containers" includes bulk containers of, for example, designed for a capacity of equal to or greater than 10 metric tons, especially ISO containers or road tankers for a mass of 20 metric tons. The term "containers" also includes those with a medium capacity, for example, with a capacity of equal to or greater than 10 kg. For example, containers with a capacity of 5 gallons, 60 kg or 240 kg are included. The term "container" also includes those with a small capacity, for example with a capacity of 10 kg or less. While bulk containers often may be used during storing, transportation or for large-scale industrial applications, containers with smaller volume often may be used by retailers for storing and/or distribution, for example, for application of the composition in certain machinery, for example, in apparatus used for cleaning electronic parts, in copiers or printers for toner fixation, or for cleaning and degreasing metals.

The term "conditions" required for handling flammable products but which are omitted in at least one step of handling according to the present invention, includes also active precautions against hazards of flammability. Such measures which can be omitted in at least one step of handling according to the present invention include the presence of inert gas, for example, of nitrogen or argon, in the gas space above the composition of HFC-365mfc during handling, for example, during storage, transportation or application of the mixtures; the occlusion of oxygen during handling the composition, or by applying pressurised conditions to prevent oxygen or air to enter the gas space above the liquid mixture; or the provision of means for protection against the formation of electric sparks, for example, by grounding. A preferred embodiment of the present invention concerns transporting the composition in a container which is not labelled to contain a flammable product. This transportation includes the transportation over short distances, e.g. within rooms or facilities or longer distances, e.g. within cities, countries or even from one continent to another, for example, by hand, by car, by railway, ships, aeroplanes, respectively, or other means suitable to transport containers.

Another preferred embodiment comprises storing the composition in a container which is not labelled to contain a flammable product. The term "storing" is intended to include short term storage and long term storage. For example, the storing can extend to periods being equal to or longer than 1 minute. It can extend to periods being equal to or shorter than 7 days. Long term storage is also possible, for example, storing the mixture for periods which are longer than 7 days. In principle, the upper limit of long term storage is not critical. Practically, the upper limit may be equal to or shorter than some years, for example, equal to or shorter than 1 year.

According to another preferred embodiment, the method according to the present invention comprises opening a container containing HFC-365mfc and

TDCE in an environment which is not protected in particular against flammability hazards. Usually, when the container is opened, for example, to inspect its contents, to adapt it to couplings before transferring a part of it into other containers or into lines to deliver it to another location, or for its application onto an item to be treated with it (e.g. for degreasing or cleaning) a part of the gas phase in the container, or even, by spilling, a part of the liquid comprised in the container comes into contact with the surrounding atmosphere. When containers containing flammable fluids are opened, the environment must be protected against the hazards of flammability. For example, the container must be grounded. These are examples of precautions which can be omitted in at least one step of handling the compositions according to the present invention.

Another preferred embodiment of the present invention comprises transferring the composition from a first container to a second container or a surface in an environment which is not protected in particular against flammability hazards. For transferring flammable liquids from one container to another, precautions must be made. For example, a pump must be used which is especially suitable for flammable liquids. Sometimes, containers which are to be refilled are flushed with inert gas. Especially if one or both containers are located in closed rooms the rooms must be vented to remove flammable liquid from the environment, or fire extinguishers must be present. These are examples which can be omitted in at least one step when compositions according to the invention are applied.

A step of transferring the composition to a surface is performed for example when the composition is transferred from the container to the surface of an item, made for example from metal, glass or plastic, for degreasing it, for otherwise cleaning it, for drying it or for removing heat from its surface. Also in this case, the step of transferring flammable fluids is accompanied by taking precautions against the hazards of flammability as described before. Also here, such precautions can be omitted in the method of the present invention. Still another embodiment of the present invention comprises contacting a surface with the composition in an environment which is not protected in particular against flammability hazards. The surface which is contacted can be made from different materials and for different purposes.

For example, a preferred purpose for contacting the surface with the mixture comprising HFC-365mfc and TDCE is to clean or degrease it. Here, a preferred material is any metal, and the items preferably are for example, tools or construction parts, e.g. high precision parts, which comprise grease or other coatings on their surface. Such parts often have complicated surfaces and are not very easy to be cleaned, especially degreased. Alternatively, the mixtures can be applied to clean printed circuit boards contaminated by a pickling flux and residues from this flux. The purpose for contacting the surface using the method of the invention can also be meant to dry it. Articles, for example from the electronics industry, optical industry or mechanical industry in the production of high-quality precision work pieces, articles come into contact with water or moisture, be it intentionally or unintentionally. Water, for example as a moisture film, may adhere to the articles. The presence of adhering water often is undesired during further processing of the articles and/or on the serviceability and the service life of these articles. Generally, during contact of flammable compositions with such surfaces to be treated, precautions must be made to protect against the hazards of flammability. For example, the gas space surrounding the surface which is treated must be inerted, for example by adding fire preventing gases, for example nitrogen as an inerting gas. Alternatively, the intrusion of oxygen or air into the surroundings of the surfaces to be treated must be prevented. If the method according to the present invention is applied, such precautions can be omitted. According to one embodiment, the mixtures comprising HFC-365mfc and TDCE are applied in liquid form. A preferred embodiment concerns methods according to the present invention which are performed with the compositions in vapour form or liquid and vapour form. The method of the present invention is especially valuable in this preferred embodiment because flammability hazards are of especial concern if a vapour phase is concerned. A very preferred embodiment concerns a method for degreasing articles, especially when the composition is applied in vapour form.

In principle, the method according to the present invention can be performed with any non-flammable composition which comprises HFC-365mfc and TDCE. The 1,1,1,3,3-pentafluorobutane and trans- 1,2-dichloroethylene contents in the compositions according to the invention can vary within wide limits, depending on the use envisaged. The compositions applied in the method according to the invention contain HFC-365mfc and TDCE in amounts which are non-flammable. This pertains both to the liquid phase and to the vapour phase. Whether a composition is nonflammable can be checked by applicable standard methods. A preferred standard method is the method mentioned above according to DIN/EN/ISO 13736. This standard method is explained in detail in the examples. Other standards, for example, JIS K2265-1996, are known to the expert skilled in the art.

In one embodiment, the compositions which are handled according to the present invention consist of HFC-365mfc and trans- 1,2-dichloroethylene. In another embodiment, the compositions comprise a stabilizer in an amount of equal to or less than 0.5 % by weight.

It has been found that compositions containing HFC-365mfc, 95 % by weight of trans- 1,2-dichloroethylene and nearly 0.5 % by weight of isopropanol have no flashpoint. Likewise it has been found that compositions comprising only 5 % by weight of trans- 1,2-dichloroethylene have no flash point. This shows that the method of the present invention can be performed with compositions comprising HFC-365mfc and trans- 1,2-dichloroethylene in a broad range. Accordingly, the method of the invention can be applied with compositions comprising equal to or more than 2 %, preferably equal to or more than 4.5 % by weight of HFC-365mfc. Likewise, the method of the present invention can be performed with compositions comprising equal to or more than 2 %, preferably equal to or more than 4.5 % by weight of TDCE.

The method of the present invention can performed with compositions comprising equal to or less than 98 % by weight, preferably 95.5 % by weight of HFC-365mfc. It can be performed with compositions comprising equal to or less than 98 %, preferably 95.5 % by weight of TDCE.

The method of the invention can also be performed with compositions which comprise a stabilizer. In this case, the method is preferably performed with compositions in which more than 0 % by weight, preferably more than 0.05 % by weight of HFC-365mfc or TDCE, respectively, of a stabilizer is comprised.

Preferably, equal to or less than 0.5 % by weight of a stabilizer is comprised. If a stabilizer is comprised in the compositions, a respective amount of HFC-365mfc or TDCE is substituted by the stabilizer. This embodiment will be described in detail below. As is explained later in detail, the compositions may also comprise an additive. Often, the compositions contain equal to or more than 45 % by weight of 1,1,1,3,3-pentafluorobutane. They advantageously contain equal to or more than 50 % by weight thereof. In a particularly preferred way, they contain equal to or more than 60 % thereof. They often contain equal to or less than 95 % by weight thereof. Most often, they contain equal to or less than 85 % by weight thereof.

The compositions according to the invention often contain equal to or more than 5 % by weight of trans- 1,2-dichloroethylene. They preferably contain equal to or more than 15 % by weight thereof. Often, the compositions comprise equal to or less than 55 % by weight of TDCE. Preferably, they contain equal to or less than 50 % by weight of TDCE. In a particularly preferred way, they contain equal to or less than 40 % by weight of TDCE.

Various additives can optionally be present in the compositions according to the invention. The compositions according to the invention can thus contain surface-active agents or any other additives making it possible to improve the behaviour of the compositions according to the invention during their use. The nature and the amount of these additives depend on the use envisaged and are easily defined by those skilled in the art. As a general rule, the amount of additives present in the compositions according to the invention does not exceed approximately 20 % of the weight of the composition, most often not more than 10 %. Preferably, less than 5 % by of additives are comprised.

Preferably, the composition does not comprise chlorofluorocarbons, hydrochlorofluorocarbons or saturated or unsaturated fluoroether compounds.

In one embodiment, the inventive method is performed with compositions consisting of HFC-365mfc and TCDE. This embodiment is preferably performed with compositions in which HFC-365mfc and TDCE are comprised in proportions in which they form an azeotrope or pseudoazeotrope.

In another preferred embodiment, the compositions containing 1,1,1,3,3-Pentafluorobutane and/or TDCE comprise a stabilizer. For example, HFC-365mfc can be stabilized against dehydrohalogenation, or TDCE can be stabilized against polymerisation. Non-flammable compositions comprising

HFC-365mfc, TDCE and one or more stabilizers can be advantageously be applied in the methods of the present invention.

In the method according to the present invention, preferably, an alkanol is comprised in the composition as a stabilizer. An especially preferred alkanol is isopropanol. Isopropanol can stabilize both compounds against degradation and polymerisation, respectively. Its amount in the mixture of HFC-365mfc and TDCE often is equal to or higher than 0.05 % by weight. Preferably, it is equal to or higher than 0.1 % by weight. Its amount is often lower than 0.5 % by weight. Preferably, it is equal to or lower than 0.4 % by weight. Very preferably, it is equal to or lower than 0.25 % by weight. It has been found that mixtures comprising HFC-365mfc, TDCE and isopropanol also behave azeo trope-like. So, isopropanol enters the vapour phase together with HFC-365mfc and TDCE and continues its stabilizing effect. Consequently, the proportions given above for the content of HFC-365mfc, TDCE and, if comprised, which is preferably the case, isopropanol, are intended to describe the content of the compositions in the liquid phase and in the gas phase.

It must be considered especially surprising that mixtures comprising HFC-365mfc, TDCE and e.g. isopropanol are non-flammable and can be applied in the method of the present invention at all.

Fundamentally the thermodynamic state of a fluid is defined by four interdependent variables : the pressure (P), the temperature (T), the composition of the liquid phase (X) and the composition of the gas phase (Y). An azeo trope is a specific system containing at least two components in which, at a given temperature and a given pressure, X is exactly equal to Y. A pseudo-azeotrope is a system containing at least two components in which, at a given temperature and a given pressure, X is substantially equal to Y. In practice, this means that the constituents of such azeotropic or pseudo-azeotropic systems cannot be easily separated by distillation and consequently their composition remains substantially constant in solvent cleaning operations, as well as in operations for recovering spent solvents by distillation. For the purposes of the present invention, for mixtures which form an azeotrope, the term "pseudo-azeotrope" is understood to mean a mixture of two or a number of constituents whose boiling point (at a given pressure) differs from the boiling point of the azeotrope by at most 0.2⁰C.

1,1,1,3,3-Pentafluorobutane and trans- 1,2-dichloroethylene form a binary azeotrope or pseudo-azeotrope when their mixture consists essentially of 56 % to 82 % by weight of 1,1,1,3,3-pentafluorobutane and of 44 to 18 % by weight of trans- 1,2-dichoroethylene. A preferred composition forming an azeotrope or pseudo-azeotrope consists of 60 to 78 % by weight of 1,1,1,3,3-pentafluorobutane and of 40 to 22 % by weight of trans- 1,2-dichloroethylene. At a pressure of 1022 mbar, the binary composition consisting essentially of approximately 70 % by weight of 1,1,1,3,3-pentafluorobutane and of approximately 30 % by weight of trans-l,2-dichloroethylene constitutes an azeotrope whose boiling point is approximately 36.3⁰C. This composition is very advantageous.

For the ternary compositions comprising isopropanol, it has been found that the composition of the vapour phase essentially corresponds to the composition in the liquid phase. Hence, the non-flammable compositions of

1,1,1,3,3-pentafluorobutane, trans- 1,2-dichloroethylene and isopropanol form a ternary pseudo-azeotrope when their mixture consists essentially of 55.5 % to 81.5 % by weight of 1,1,1,3,3-pentafluorobutane, 44 to 18 % by weight of trans- 1,2-dichoroethylene and between > 0 and equal to or preferably less than 0.5 % by weight of isopropanol. Preferably, isopropanol is comprised in an amount of less than 0.5 % by weight of the composition, very preferably in an amount of equal to or less than 0.4 % by weight, and especially in an amount of equal to or less than 0.3 % by weight. An azeotrope formed from ternary compositions of HFC-365mfc, TDCE and isopropanol has not been identified. For compositions that do not form an azeotrope, the term "pseudo-azeotrope" in the frame of the present invention, denotes a composition of which, after evaporation at a constant temperature of 50 % of the initial liquid mass, the per cent variation of the vapor pressure between that of the initial mixture and that of the final mixture resulting is lower than about 10 %. See on the matter the paper of D. A. Didion and D. B. Bivens in Int. J. of Refrigeration 13 (1990), pages 163 to 175.

A preferred composition forming a pseudo-azeotrope consists of 59.5 to

77.5 % by weight of 1,1,1,3,3-pentafluorobutane, 40 to 22 % by weight of trans- 1,2-dichloroethylene and between > 0 and equal to or preferably less than 0.5 % by weight of isopropanol; preferably, the content of isopropanol is less than 0.5 % by weight, preferably equal to or less than 0.4 % by weight, especially preferably equal to or less than 0.3 % by weight. Very preferred compositions consist essentially of

59.6 to 77.5 % by weight 1,1,1,3,3-pentafluorobutane, 40 to 22.1 % by weight of TDCE and between more than 0 and 0.4 % by weight of isopropanol.

The method of the present invention using the non-flammable compositions described above can principally be applied to methods for which mixtures comprising HFC-365mfc and TDCE, preferably together with stabilizers, especially isopropanol, have been used heretofore. In particular, the method according to the invention can be applied when the compositions are used or intended to be used as cleaning agents, or as surface cleaning agent, e.g. for cleaning parts, for example, precision parts, made of plastics or inorganic material, for example made from metal, glass, or ceramics. The method of cleaning can be applied in an ultrasound bath. The term "cleaning" includes, for example, cleaning textiles, degreasing in general, for example, degreasing animal hides, surface cleaning, for example cleaning, especially degreasing, of metal parts, cleaning of optical lenses, cleaning of electronic devices, e.g. printed circuit boards contaminated by a pickling flux and residues from this flux, for cleaning tubes and other parts of climatisation apparatus by flushing them, cleaning solid chemicals insoluble in the composition. For example, small particles with a size of less than 10^~3 m, micro particles with a size of less than 10^~6 m and nano particles with a size of less than 10^~9 m, of carbon or inorganic compounds, can be cleaned. Solid objects can be desiccated by removing the water adsorbed at their surface. The method according to the present invention can also be applied when the compositions are used or intended to be used as solvent, for example, as solvent for chemical reactions or as a carrier fluid for transporting dissolved compounds, including their use as carrier for chromatographic purposes, or as solvent for chemicals ready to use, e.g. lacquers or paints.

A further embodiment of the present invention are containers or other containments, which are not labelled with warning signs concerning the hazards of flammability, and which comprise non-flammable compositions of HFC-365mfc and TDCE, and, preferably, a stabilizer, especially isopropanol. The finding that compositions comprising HFC-365mfc and trans- 1,2-dichloroethylene in a broad range, optionally in the presence of stabilizers, especially isopropanol, are non-flammable makes these mixtures especially valuable in the method of the present invention. It can for example be used in applications in which the initial content of HFC-365mfc and 1,2-trans-dichloroethylene, respectively, is shifted from a starting concentration to any concentration between 2 and 98 % by weight.

The invention makes advantage of the surprising finding of non-flammability of mixtures comprising HFC-365mfc and TDCE which are both flammable compounds and especially when they comprise the flammable compound isopropanol as stabilizer, the consequence being that at least in one step, its handling is simplified and less costly.

While the Safety Advices of national and regional law give a technical teaching how to handle flammable compositions, and the Risk Advices teach how to label them, the invention provides, for the non-flammable compositions explained above, a method with another technical teaching; it is contrary to what is taught by Safety andd Risk Advices. For example, one need not take precautions against flammability hazards, e.g. one need not operate under inert gas when handling the compositions, one need exclude oxygen or air from entering compartments where the composition is applied or handled, one need not ground the apparatus or containers concerned; one need not take care of warning against said hazards, e.g. one need not fix labels (and later possibly remove them) to the containers or transporting means indicating the risks of flammability, road tankers or trains can pass through regions otherwise restricted. In case of leakage, security forces must not be alarmed, and so on. A further advantage of not labelling is that people are not unnecessarily unsettled by erroneous warnings against fire hazards. The examples below, without implied limitation, illustrate the invention in a more detailed way.

Example 1 : Preparation of a mixture containing 1,1,1,3,3-pentafluorobutane (HFC-365mfc), trans- 1,2-dichloroethylene (TDCE) and isopropanol as a stabilizer Trans- 1,2-dichloroethylene which contained around 0.5 % by weight of isopropanol was mixed with 1,1,1,3,3-pentafluorobutane in a weight ratio of 30:70. The resulting mixture contained 68.99 % by weight of HFC-365mfc, 30,86 % by weight of TDCE and 0.16 % by weight (the difference of 0.01 % by weight to 100 % by weight is a result of rounding). Flammability tests : The flammability test was performed according to DIN/EN/ISO 13736. The determination was performed in a closed cup of 75 ml inner volume. The cup also comprises a stirrer and a probe to determine the temperature of the liquid to be tested. The cup also comprises means to rise the temperature. In the lid of the cup, a device is contained which allows to direct a test flame to the surface of the liquid the combustibility of which has to be determined. The apparatus used had a thermo detector which responds to fast rise of measured temperature (indicating that a flame occurred).

The stirrer rotated slowly (about 30 rpm). The liquid in the cup was slowly warmed up. Whenever the temperature rose by 0.5⁰C, the test flame was ignited and checked if the thermo sensor responded. If yes, a process of combustion in the gas phase above the liquid had occurred. Example 1.1 : Mixture of example 1

For the composition of example 1, no flash point was observed according to DIN/EN/ISO 13736. By mixing HFC-365mfc with 1,2-trans-dichloroethylene which comprised about 0.5 % by weight of isopropanol as stabilizer, further compositions were prepared and tested. The mixing ratios of HFC-365mfc and isopropanol- stabilized 1,2-trans-dichloroethylene (TDCE) and the test results are compiled in the following table (amounts given in parts by weight) :

The examples denoted as "a" were trials repeating the preceding test with the same mixing ratio to confirm the respective result.

Determination of thermodynamic properties :

The composition of example 1 was subjected to a distillation at atmospheric pressure using a Vigreux column. The boiling temperature remained constantly equal to 35.7⁰C. After 50 % by weight of the composition had been destilled, the composition of the distillate and the residual composition in the distillation vessel was analysed by gas phase chromatography. The results obtained are collated in Table I.

TABLE I

The composition of the distillate and residue in the vessel obtained shows the existence of a pseudo-azeotrope-like behaviour of the composition consisting of 1,1,1,3,3-pentafluorobutane, trans- 1,2-dichloroethylene and isopropanol. The determination of the composition of the distillate and the residue also shows that the vapour phase comprises all three compounds which are flammable per se, but non-flammable as composition. It also shows that the stabilizing effect of isopropanol is also expected for the vapour of the composition. Methods according to the present invention : Example 2 : Performing the method according to the invention

2.1. Textile cleaning

Textile articles are filled into a washing machine operating with the composition of example 1. At least one of the following steps is not performed under conditions required for handling flammable products : The step of filling in the textiles into the machine, the step of washing the textiles, the step of opening the machine and the step of drying the textiles to remove residual composition from the textiles. For example, one or more of these steps is performed without precautions against the hazard of fire, including precautions to prevent contact of the composition and the textiles with the air. Also, the washing machine is not labelled concerning hazards of flammability.

2.2. Example 2.1. is repeated, using carpets as item to be cleaned

2.3. Cleaning of complicated metal parts (vapour-degreasing)

Metal parts can be greased on the surface to protect them against corrosion. Adhering grease can also be caused by the application of drawing wax, drawing grease or drawing oil during shaping the metal parts. The step of cleaning high- precision metal parts is performed in a vapour degreaser.

A vapour immersion unit which has two solvent-filled sumps can be applied. A boil cleaning tank comprises a solvent mixture which, additional to a higher- boiling solvent component additionally comprises the non-flammable composition described above. A rinsing tank only comprises the non-flammable composition described above.

The metal parts are assembled in a basket and immersed into the boil cleaning tank to dissolve adhering grease. They are then removed and immersed into the rinsing tank wherein adhering solvent mixture from the boil cleaning tank is rinsed. The parts then are covered with the lower-boiling composition of the rinsing tank. The basket is then removed from the rinsing tank and kept in the gas space above tanks. The solvent adhering on the surface of the metal parts changes into the vapour phase. Near the top of the vapour degreaser are three sets of cooled coils where the vapor condenses before it escapes from the unit. The condensed vapour flows back to a clean condensate tank and can be reused. A part of the vapour is fed to a drying unit to remove water from it. The degreased dry metal parts can then be removed from the vapour degreaser.

At least one of the following steps is, and optionally two or more and even all flowing steps is not performed under conditions required for handling flammable products (e.g. prevention of contact with air, grounding) : opening a storage container comprising the composition of example 1; connecting a line to it; transferring the composition by means of pumps into the cold sump and into the boil sump; disconnecting the line; closing the storage container; opening the vapour degreaser to position greased metal parts on the perforated metal; removing the degreased metal parts from the perforated metal; refilling the vapour degreaser.

There also is no label warning against flammability hazards on the storage tank, the lines, the vapour degreaser, and the rooms where storage tank and vapour degreaser is located (the room did not contain flammable materials).

The composition used is not kept under nitrogen or argon, it must not be kept away from flammable organic substances, ignition sources or combustible material. This example shows that the method of the invention can be applied to the composition both in the liquid and the vapour phase.

2.4. A printed circuit manufactured by soldering electric parts onto a respective board is immersed into a container partially filled with the composition of example 1 to remove adhering solder. After the immersion and removal of the solder, the printed circuit is lifted out of the composition and dried. At least one of the following steps is, and optionally two or more or even all steps are, not performed under conditions required for handling flammable products : partially filling the container with the composition of example 1; positioning the printed circuits above the composition; immersing it into it; removing it; drying it; removing spent composition from the container and transferring it to a distillation apparatus to recover it for reuse.

2.5. Transporting the composition : around 20 metric tons of the composition of example 1 shall be transported to a site of use by means of a road tanker. Therefore, a line is connected between the container on the production site and the container carried by the road tanker. By means of a pump, the composition of example 1 is transferred. Afterwards, the line is disconnected and the road tanker leaves for its destination where the composition is transferred to a storage container. At least one of the following steps is, and optionally two or more and even all of the following steps are, not performed under conditions required for handling of flammable products : connecting the containers; transferring the composition from one container to the other at the site of production; disconnecting the containers; transporting the composition by means of the road tanker to the site of use (including passing tunnels prohibited for road tankers transporting flammable products); transferring the composition to a storage container at the site of use; connecting and disconnecting the containers for that purpose. Besides, none of the storage containers and also not the road tanker must be labelled with a warning against the hazards of flammable products. Further, no inert gas must be applied to inert the atmosphere surrounding the container or the room in which it is handled.

2.6. Neither the data sheet nor any freight documents must contain a warning against the hazards of fire. Example 3 (Comparison example) :

To the composition of example 1, methanol was added so that the resulting mixture contained 3.6 % by weight of methanol. A flash point was observed at - 21.5⁰C. Such a composition ought to be labelled according to RlO : "Flammable".

Claims

C L A I M S

1 - A method of using a nonflammable composition comprising 1,1,1,3,3-pentafluorobutane and trans- 1,2-dichloroethylene which comprises at least one step wherein said composition is not handled under conditions required for handling of flammable products.

2 - A method according to claim 1, which comprises transporting the composition in a container which is not labeled to contain a flammable product.

3 - A method according to claim 1, which comprises storing the composition in a container which is not labeled to contain a flammable product.

4 - A method according to claim 2 or 3, which comprises opening the container containing the composition in an environment which is not protected in particular against flammability hazards.

5 - A method according to claim 1, which comprises transferring the composition from a first container to a second container or a surface in an environment which is not protected in particular against flammability hazards.

6 - A method according to claim 1, which comprises contacting a surface with the composition in an environment which is not protected in particular against flammability hazards.

7 - A method according to claim 6 wherein the surface is contacted with the composition which is in the vapour state.

8 - A method according to claim 7, wherein the composition is used to remove grease from the surface.

9 - A method according to claim 1, wherein the composition is an azeotropic or pseudo-azeotropic mixture consisting essentially or consisting of 1,1,1,3,3-pentafluorobutane and trans- 1,2-dichloroethylene and optionally a stabilizer.

10 - A container containing a nonflammable composition comprising 1,1,1,3,3-pentafluorobutane and trans- 1,2-dichloroethylene, which container is not labeled to contain a flammable product. 11 - A container according to claim 10, wherein the composition is an azeotropic or pseudo-azeotropic mixture consisting essentially or consisting of 1,1,1,3,3-pentafluorobutane and trans- 1,2-dichloroethylene and optionally a stabilizer, which container is not labeled to contain a flammable product.