Compositions – Humidostatic – water removive – bindive – or emissive
Reexamination Certificate
1996-03-29
2001-04-03
Gupta, Yogendra (Department: 1751)
Compositions
Humidostatic, water removive, bindive, or emissive
C510S175000, C510S412000, C252S364000, C134S012000, C134S042000
Reexamination Certificate
active
06210602
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to compositions based on 1,1,1,3,3-pentafluorobutane (HFC-365mfc) and to a process for removing water from a solid surface by means of these compositions.
TECHNOLOGY REVIEW
In the fields of the electrical, electronics, optical and mechanical industries in particular it may happen that in the course of the production of high-precision articles, some components of these articles come, intentionally or not, into contact with water or moisture. These are, for example, components of liquid crystal display devices, of electronic components, of timepiece components and of optical components such as lenses. The water may adhere to the surface of these articles and subsequently cause some detrimental effects during subsequent stages of their application or may deteriorate the quality of the articles into which these components are finally incorporated.
It is consequently indispensible, in the case of many precision components, that they should be completely freed from any water adhering to their surface, before any subsequent application. This operation of removing water at the surface can be carried out especially by displacing water by means of a water-immiscible, dense organic liquid optionally containing a surface-active agent; in this connection, compositions based on 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113) and surface-active agents have been described in U.S. Pat. No. 4,594,177. However, CFC-113 forms part of fully halogenated chlorofluorocarbons which are currently suspected of attacking or damaging stratospheric ozone.
European Patent Application EP-A-0512885 describes an azeotropic composition based on 1,1,1,3,3-pentafluorobutane and methanol for cleaning, degreasing and drying solid surfaces. This composition avoids the abovementioned disadvantage of the CFC-113-based compositions. However, the use of this known composition for displacing water from solid surfaces presents problems linked with the solubility of methanol in water; in fact, during successive uses the compositions become depleted in methanol and thus lose their properties. In addition, methanol has the disadvantage of being toxic and flammable.
Japanese Patent Application JP-A-05/168805 describes a composition for removing water adhering to a surface, including 1,1,1,3,3-pentafluorobutane and a surfactant consisting of a salt of an organic acid and of an organic base. These compositions exhibit poor dryability.
SUMMARY OF THE INVENTION
The subject of the invention is compositions including 1,1,1,3,3-pentafluorobutane, exhibiting good ability to remove water from solid surfaces, without exhibiting the abovementioned disadvantages of the known compositions.
DETAILED DESCRIPTION OF THE INVENTION
The invention consequently relates to compositions including 1,1,1,3,3-pentafluorobutane and at least one surface-active agent chosen from hydrophobic organic surface-active agents of the amine type, of the carboxylic acid diester type and of the phosphoric acid ester type. Surface-active agents of the amine type are intended to denote surface-active agents including at least one amine group. Surface-active agents of the carboxylic acid diester type are intended to denote surface-active agents including at least two carboxylic acid ester groups. Surface-active agents of the phosphoric acid ester type are intended to denote surface-active agents including at least one phosphoric acid ester group.
In the case where the surface-active agent of the compositions according to the invention is of the amine type it may be a primary, secondary or tertiary amine, for example a mono-, di- or trialkylamine in which the alkyl group may be linear or branched. Linear or branched, primary alkylamines containing at least 6, preferably at least 8 carbon atoms are preferred. 2-Ethylhexylamine, octylamine and nonylamine, as well as their mixtures, are particularly preferred.
In the case where the surface-active agent is of the carboxylic acid diester type, the latter is advantageously an aromatic diester. Diesters of phthalic acid are preferred. Dioctyl phthalate and di(2-ethylhexyl) phthalate, and their mixtures, are particularly preferred.
In the case of a surface-active agent of the phosphoric acid ester type, the latter may advantageously be a triester of phosphoric acid. Among the triesters of phosphoric acid, alkyl, aryl and alkyl aryl phosphates are recommended. Trialkyl phosphates are particularly advantageous and tributyl phosphate is very particularly preferred.
In an advantageous embodiment of the compositions according to the invention, the composition includes (a) a surface-active agent of the amine type and (b) a surface-active agent of the carboxylic acid diester type or a surface-active agent of the phosphoric acid ester type. The composition preferably includes a surface-active agent of the amine type and a surface-active agent of the phosphoric acid ester type. In a particularly preferred manner the surface-active agent of the amine type is octylamine and/or nonylamine and the surface-active agent of the phosphoric acid ester type is tributyl phosphate. In this embodiment of the invention the molar ratio (a):(b) is preferably from 0.3:1 to 1.5:1.
The compositions of the invention preferably include from 5 to 99.995% by weight of 1,1,1,3,3-pentafluorobutane and from 0.005% to 10% by weight of the surface-active agent.
In an especially advantageous embodiment of the compositions according to the invention, the latter contain from 90 to 99.995% by weight of 1,1,1,3,3-pentafluorobutane.
In addition to the compounds described above, the compositions according to the invention may contain other additives making it possible to improve the performance of the compositions when they are used, such as stabilizers, deemulsifiers and/or antifoams.
In addition to 1,1,1,3,3-pentafluorobutane and to the surface-active agent, the compositions according to the invention may contain other hydrocarbons, especially halogenated hydrocarbons. The compositions according to the invention may especially contain 1,1-dichloro-1-fluoroethane (HCFC-141b). Compositions in accordance with the invention are those including from 70 to 95% by weight of 1,1-dichloro-1-fluoroethane and from 3 to 25% by weight of 1,1,1,3,3-pentafluorobutane, especially those including the azeotrope of 1,1-dichloro-1-fluoroethane and of 1,1,1,3,3-pentafluorobutane.
Compositions consisting essentially of 1,1,1,3,3-pentafluorobutane and of at least one surface-active agent are, nevertheless, preferred.
The compositions according to the invention are liquid compositions which are particularly well suited for displacing water from solid surfaces. The compositions according to the invention satisfy the strictest criteria applicable to the compositions employed for removing water from solid surfaces by displacing it. Thus, they are particularly effective for displacing more than 75%, generally at least 99%, or even all of the water present on a solid surface. The displacement of the water is very fast. The compositions according to the invention do not form any emulsion with the water but, on the contrary, promote the formation of two phases, a lower phase consisting essentially of the composition according to the invention, in which a little water may possibly be dissolved, and an upper phase consisting essentially of the displaced water. This permits a simple subsequent separation between the displaced water and the composition. Moreover, the compositions according to the invention lend themselves to a large number of successive uses without their constitution undergoing any appreciable alteration. In fact, the surface-active agent is not significantly extracted from the compositions by the water which is displaced and subsequently separated from the latter.
The compositions according to the invention are suitable for drying a wide variety of different materials. They are suitable especially for drying articles made of metal, glass, ceramics, precious stones or plastics.
The invention consequently also relates to a process
Barthelemy Pierre
Paulus Mireille
Gupta Yogendra
Schneller Marina V.
Solvay S.A.
Venable
Webb Gregory E.
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