WO1992011350A1

WO1992011350A1 - Dewatering compositions comprising 1,1-dichloro-1-fluoroethane; dichlorotrifluoroethane; and alkanol having 1 to 4 carbon atoms

Info

Publication number: WO1992011350A1
Application number: PCT/US1991/009001
Authority: WO
Inventors: Ellen Louise Swan; Rajat Subhra Basu; Gary J. Zyhowski
Original assignee: Allied-Signal Inc.
Priority date: 1990-12-18
Filing date: 1991-11-27
Publication date: 1992-07-09

Abstract

The present invention provides compositions comprising about 0.4 to about 79.6 weight percent 1,1-dichloro-1-fluoroethane, about 0.4 to about 79.6 weight percent dichlorotrifluoroethane selected from the group consisting of 1,1-dichloro-2,2,2-trifluoroethane, 1,2-dichloro-1,1,2-trifluoroethane, and mixtures thereof, and from about 5 to about 20 weight percent of alkanol having 1 to 4 carbon atoms. These compositions are useful in dewatering non-absorbent articles such as made from metallic, ceramic, or polymeric materials.

Description

DEWATERING COMPOSITIONS COMPRISING

1.1-DICHLORO-1-FLUOROETHANE: DICHLOROTR FLUOROETHANE;

AND ALKANOL HAVING 1 TO 4 CARBON ATOMS

FIELD OF THE INVENTION

The present invention relates to improved compositions for removal of water from the surface of 0 non-absorbent articles. More particularly, the invention involves a water removal composition comprising 1,1-dichloro-l-fluoroethane, dichlorotrifluoroethane, and alkanol having 1 to 4 carbon atoms.

5 BACKGROUND OF THE INVENTION

Many commercial operations involve the removal of water from or drying of non-absorbent articles such as made from metallic, ceramic including glass, or polymeric _Q materials. Currently used drying compositions contain l,l,2-trichloro-l,2,2-trifluoroethane (known in the art as CFC-113), which is one isomer of trichlorotrifluoroethane, as one component. One example of such a drying or dewatering composition is a composition of about 85 weight percent 1,1,2-trichloro-l,2,2-trifluoroethane and about 15 weight percent 2-propanol; the l,l,2-trichloro-l,2,2-trifluoroethane acts as a water-immiscible component while the 2-proρanol acts as a water-miscible component. 0 Fully halogenated chlorofluorocarbons are suspected of causing environmental problems in connection with the earth's protective ozone layer. Thus, the art is seeking new compounds which do not contribute to environmental 5 problems but yet provide the dewatering properties of CFC-113. Currently, of particular interest, are fluorocarbon based mixtures which are considered to be stratospherically safe substitutes for presently used fully halogenated chlorofluorocarbons. Mathematical _Q models have substantiated that hydrochlorofluorocarbons, such as 1,1-dichloro-l-fluoroethane (known in the art as HCFC-141b) and dichlorotrifluoroethane (two isomers: known in the art as HCFC-123 or HCFC-123a), will not adversely affect atmospheric chemistry, being negligible _e contributors to ozone depletion and to green-house global warming in comparison to the fully halogenated species.

Commonly assigned U.S. Patent 4,836,947 discloses azeotrope-like mixtures of 1,1-dichloro-l-fluoroethane and ethanol. Commonly assigned U.S. Patent 4,842,764 discloses azeotrope-like mixtures of 1,1-dichloro-l-fluoroethane and methanol. Commonly assigned U.S. Patent 4,960,535 discloses azeotrope-like mixtures of 1,1-dichloro-l-fluoroethane; dichlorotrifluoroethane; and a mono- or di-chlorinated

C. or C~ alkane. Commonly assigned U.S. Patent

4,965,011 discloses azeotrope-like mixtures of

1,1-dichloro-l-fluoroethane; dichlorotrifluoroethane; and nitroraethane.

Kokai Patent Publication 103,686, published April 20, 1989, discloses an azeotropic mixture of 55 to 80 weight percent dichlorotrifluoroethane and 20 to 45 weight percent 1,1-dichloro-l-fluoroethane. Kokai Patent Publication 136,981, published May 30, 1989, discloses a degreasing cleaning agent of an azeotropic mixture of 67 weight percent l,l-dichloro-2,2,2-trifluoroethane and 33 weight percent 1,1-dichloro-l-fluoroethane, plus hydrocarbons, alcohols, ketones, chlorinated hydrocarbons, and esters.

Kokai Patent Publication 136,982, published May 30, 1989, discloses a buff-grinding cleaning agent of an azeotropic mixture of 67 weight percent l,l-dichloro-2,2,2-trifluoroethane and 33 weight percent 1,1-dichloro-l-fluoroethane, plus hydrocarbons, alcohols, ketones, chlorinated hydrocarbons, and esters. Kokai Patent Publication 137,253, published May 30, 1989, discloses a resist developing agent of an azeotropic composition of 67 weight percent l,l-dichloro-2,2,2-trifluoroethane and 33 weight percent 1,1-dichloro-l-fluoroethane, plus hydrocarbons, alcohols, ketones, chlorinated hydrocarbons, and esters.

Kokai Patent Publication 137,259, published May 30, 1989, discloses a resist separating agent of an azeotropic composition of 67 weight percent

1,l-dichloro-2,2,2-trifluoroethane and 33 weight percent 1,1-dichloro-l-fluoroethane, plus hydrocarbons, alcohols, ketones, chlorinated hydrocarbons, aromatics, and esters. Kokai Patent Publication 138,300, published May 31, 1989, discloses a flux cleaning agent of an azeotrope of 67 weight percent l,l-dichloro-2,2,2-tri£luoroethane and 33 weight percent 1,1-dichloro-l-fluoroethane, plus hydrocarbons, alcohols, ketones, and chlorinated hydrocarbons.

Kokai Patent Publication 139,861, published June 1, 1989, discloses a dry-cleaning agent of 67 weight percent l,l-dichloro-2,2,2-trifluoroethane and 33 weight percent 1,1-dichloro-l-fluoroethane, plus hydrocarbons, alcohols, ketones, chlorinated hydrocarbons, and surfactants. Commonly assigned U.S. Patent 4,894,176 discloses azeotrope-like mixtures of 1,1-dichloro-l-fluoroethane; dichlorotrifluoroethane; and methanol wherein the methanol is present up to about 4.7 weight percent. The reference does not teach or suggest the present dewatering compositions.

Commonly assigned U.S. Patent 4,863,630 discloses azeotrope-like mixtures of 1,1-dichloro-l-fluoroethane; dichlorotrifluoroethane; and ethanol wherein the ethanol is present up to about three weight percent. The reference does not teach or suggest the present dewatering compositions.

Kokai Patent Publication 139,104, published May 31, 1989, discloses a solvent of an azeotropic mixture of 67 weight percent l,l-dichloro-2,2,2-trifluoroethane and 33 weight percent 1,1-dichloro-l-fluoroethane, plus hydrocarbons, alcohols, ketones, chlorinated hydrocarbons, and surfactants. The reference teaches the following compositions: 75 percent azeotrope and 25 percent methanol; 75 percent azeotrope, 5 percent acetone, and 20 percent isopropanol; and 75 percent azeotrope, 5 percent trichloroethylene, and 20 percent ethanol but the reference does not teach the present compositions. Also, because the reference teaches that the azeotrope alone removes water as effectively as the azeotrope with another component, the reference would not lead one to the present dewatering compositions. Because the use of l,l,2-trichloro-l,2,2-trifluoroethane is being phased out in the future, the industry and especially the optical industry is looking for an acceptable replacement for dewatering compositions of l,l,2-trichloro-l,2,2-trifluoroethane and 2-propanol. As such, a need in the art exists for an environmentally acceptable composition which dewaters as effectively as l,l,2-trichloro-l,2,2-trifluoroethane and 2-proρanol.

We tried to dewater glass slides by using

2-propanol alone and found that 2-ρropanol does not dewater. We then tried to dewater glass slides by using

1,1-dichloro-l-fluoroethane alone and found that 1,1-dichloro-l-fluoroethane also does not dewater. We then tried to dewater glass slides by using l,l-dichloro-2,2,2-trifluoroethane alone and found that l,l-dichloro-2,2,2-trifluoroethane also does not dewater.

We then attempted to dewater glass slides by using a composition of 80 percent by weight

1,1-dichloro-l-fluoroethane and 20 percent by weight l,l-dichloro-2,2,2-trifluoroethane and found that this composition does not dewater.

SUMMARY OF THE INVENTION

We were then surprised to find that compositions of 1,1-dichloro-l-fluoroethane, dichlorotrifluoroethane, and alkanol having 1 to 4 carbon atoms dewater non-absorbent articles. We were even more surprised to find that compositions comprising about 0.4 to about 79.6 weight percent 1,1-dichloro-l-fluoroethane, about 0.4 to about 79.6 weight percent dichlorotrifluoroethane selected from the group consisting of 1,l-dichloro-2,2,2-trifluoroethane, l,2-dichloro-l,l,2-trifluoroethane, and mixtures thereof, and from about 5 to about 20 weight percent of alkanol having 1 to 4 carbon atoms dewater as effectively as compositions of about 85 weight percent

1,1,2-trichloro-l, 2,2-trifluoroethane and about 15 weight percent 2-propanol.

As such, the present invention fulfills the need in the art for an environmentally acceptable composition which dewaters as effectively as 1,1,2-trichloro-l,2,2-trifluoroethane and 2-ρropanol.

Thus, it is an object of this invention to provide novel compositions based on 1,1-dichloro-l-fluoroethane and dichlorotrifluoroethane which are liquid at room temperature and which are useful for dewatering.

Another object of the invention is to provide novel environmentally acceptable dewatering compositions for use in the aforementioned applications.

Other objects and advantages of the invention will become apparent from the following description.

DESCRIPTION OF THE INVENTION

Preferably, novel compositions comprise about 40 to about 79.6 weight percent 1,1-dichloro-l-fluoroethane, about 0.4 to about 40 weight percent dichlorotrifluoroethane, and from about 5 to about 20 weight percent of alkanol having 1 to 4 carbon atoms. The dichlorotrifluoroethane component can be one of its isomers: l,l-dichloro-2,2,2-trifluoroethane (known in the art as HCFC-123); l,2-dichloro-l,l,2-trifluoroethane

(known in the art as HCFC-123a); or mixtures thereof in any proportions. The preferred isomer of dichlorotrifluoroethane is HCFC-123. Preferably, "commercial HCFC-123" which is available as "pure" HCFC-123 containing about 90 to about 95 weight percent of HCFC-123, about 5 to about 10 weight percent of HCFC-123a, and impurities such as trichloromonofluoromethane, trichlorotrifluoroethane, and methylene chloride which due to their presence in insignificant amounts, have no deleterious effects on the properties of the azeotrope-like compositions, is used. "Commercial HCFC-123" is also available as "ultra-pure" HCFC-123 which contains about 95 to about 99.5 weight percent of HCFC-123, about 0.5 to about 5 weight percent of HCFC-123a, and impurities as listed above.

More preferably, the compositions comprise about 48 to about 79.6 weight percent 1,1-dichloro-l-fluoroethane, about 0.4 to about 32 weight percent dichlorotrifluoroethane selected from the group consisting of 1,l-dichloro-2,2,2-trifluoroethane, l,2-dichloro-l,l,2-trifluoroethane, and mixtures thereof, and from about 5 to about 20 weight percent of alkanol having 1 to 4 carbon atoms.

Even more preferably, the compositions comprise about 53.6 to about 79.6 weight percent

1,1-dichloro-l-fluoroethane, about 0.4 to about 26.4 weight percent dichlorotrifluoroethane selected from the group consisting of l,l-dichloro-2,2,2-trifluoroethane, l,2-dichloro-l,l,2-trifluoroethane, and mixtures thereof, and from about 5 to about 20 weight percent of alkanol having 1 to 4 carbon atoms. Even more preferably, the compositions comprise about 56 to about 79.6 weight percent

1,1-dichloro-l-fluoroethane, about 0.4 to about 24 weight percent dichlorotrifluoroethane selected from the group consisting of l,l-dichloro-2,2,2-trifluoroethane, l,2-dichloro-l,l,2-trifluoroethane, and mixtures thereof, and from about 5 to about 20 weight percent of alkanol having 1 to 4 carbon atoms.

Even more preferably, the compositions comprise about 62.4 to about 79.6 weight percent 1,1-dichloro-l-fluoroethane, about 0.4 to about 17.6 weight percent dichlorotrifluoroethane selected from the group consisting of l,l-dichloro-2,2,2-trifluoroethane, l,2-dichloro-l,l,2-trifluoroethane, and mixtures thereof, and from about 5 to about 20 weight percent of alkanol having 1 to 4 carbon atoms.

Most preferably, the compositions comprise about 5 to about 15 weight percent of alkanol having 1 to 4 carbon atoms.

Examples of commercially available alkanols having

1 to 4 carbon atoms include methanol; ethanol; 1-propanol;

2-ρroρanol; 1-butanol; 2-butanol; 2-methyl-l-ρropanol; and

2-methyl-2-propanol. The preferred alkanols are methanol; ethanol; 2-proρanol; and 2-methyl-2-propanol.

In one process embodiment of the invention, the present compositions comprising about 0.4 to about 79.6 weight percent 1, -dichloro-l-fluoroethane, about 0.4 to about 79.6 weight percent dichlorotrifluoroethane selected from the group consisting of

1,l-dichloro-2,2,2-trifluoroethane, l,2-dichloro-l,l,2-trifluoroethane, and mixtures thereof, and from about 1 to about 20 weight percent of alkanol having 1 to 4 carbon atoms may be used to dewater non-absorbent surfaces by treating the surfaces with the compositions in any manner well known to the art such as by dipping or spraying or use of conventional dewatering apparatus such as taught by commonly assigned U.S. Patents 3,589,023 and 3,559,297 which are incorporated herein by reference.

The present compositions are useful in dewatering non-absorbent articles made from metallic, ceramic including glass, or polymeric materials. Examples of metallic materials which may be dewatered by the present compositions include ferrous metals, copper, nickel, chromium, stainless steel, aluminum, and alloys. Examples of ceramic materials which may be dewatered by the present compositions include clay products; cement; silicate glasses; pure oxide ceramics such as based on alumina, zirconia, thoria, beryllia, magnesia, spinel, and forsterite; ceramic nitrides such as aluminum nitride, silicon nitride, and boron nitride; and ceramic carbides. Examples of polymeric materials which may be dewatered by the present compositions include polyamides such as those prepared by polymerization of epsilon-caprolactam, polyesters such as polyethylene terephthalate, polyolefins such as polypropylene, polycarbonates, polyimides, and polyurethanes.

The present dewatering compositions may be prepared in any known manner including weighing each component and then mixing the components. The 1,1-dichloro-l-fluoroethane; dichlorotrifluoroethane; and alkanol components of the novel compositions of the invention are known materials and are commercially available. Preferably, except for 5 "commercial HCFC-123" and its impurities, the materials should be used in sufficiently high purity so as to avoid the introduction of adverse influences upon the desired properties of the system.

_Q The present invention is more fully illustrated by the following non-limiting Examples.

COMPARATIVES

■, c Each of the compounds or compositions listed in

Table 1 below was tested for its ability to dewater. For each Comparative, 100 milliliters of each of the compounds or compositions were placed into a beaker. The percentages of the components are in weight percent. A glass slide was then dipped into water. The glass slide was then removed from the water and had a film of water thereon. The glass slide with the water film was then immersed into the beaker containing the potential dewatering agent for 10 seconds with slight agitation of the glass slide. The slide was then removed from the 5 beaker.

IA£ £_i

2-proρanol 0

1,1-dichloro-l-fluoroethane

1,l-dichloro-2,2,2-trifluoroethane

80% HCFC-14lb/20% HCFC-123

5 We determined if a compound or composition dewatered by observing the glass slide for water. Not one of the compounds or compositions listed in Table 1 dewatered the glass slide effectively.

The above procedure was repeated with a composition of 87 weight percent l,l,2-trichloro-l,2,2-trifluoroethane and 13 weight percent 2-propanol. We knew that the glass slide was dewatered because we observed a water break in the slide; the organic solvent evaporated in 90 seconds.

The above procedure was repeated with a composition of 87 weight percent 1,1,2-trichloro-l,2,2-trifluoroethane and 13 weight percent 2-propanol except that a stainless steel coupon was used instead of a glass slide. We knew that the metal coupon was dewatered because we observed a water break in the slide; the organic solvent evaporated in 60 seconds.

EXAMPLES 1-6

Each of the compounds or compositions listed in Table 2 below was tested for its ability to dewater glass slides. The procedure of the Comparatives was repeated.

In Table 2, each component is in weight percent.

IΔE E_2

Each slide came out of the beaker with a thin film of the organic dewatering agent on it but did not have any water on it because a clear break of the water layer on the surface indicated that the water layer did not exist on the slides. The organic dewatering agent then evaporated in less than two minutes.

EXAMPLES 7-8

Each of the compounds or compositions listed in Table 3 below was tested for its ability to dewater polished stainless steel coupons. The procedure of the Comparatives was repeated. In Table 3, each component is in weight percent.

_____________!

__X_________Z HCFC-Ulb HCFC-123 EIH&HΩIi 2-PROPANOL

72 18 10

8 76 19

Each slide came out of the beaker with a thin film of the organic dewatering agent on it but did not have any water on it because we observed a clear water break on the surface. The organic dewatering agent then evaporated in less than 30 seconds which is better than the 60 seconds reported above for a composition of 87 weight percent

1,1,2-trichloro-l,2,2-trifluoroethane and 13 weight percent 2-propanol. EXAMPLES 9-24

The procedure for Examples 1 through 6 is repeated with the compositions in Table 4 below.

TABLE 4

HCFC-123

20

19

17

18

16

17

15

18 - 6

18 - 7

17 - 8

16 - 10

16 - 11

15 - 12

14 - 14

EXAMPLES 25-40

The procedure for Examples 7 and 8 is repeated for the compositions in Table 4 above.

EXAMPLES 41-62

The procedure for Examples 1 through 6 and 9 through 24 is repeated except that a polymeric strip is used instead of a glass slide. EXAMPLES 63-124

The procedure of Examples 1 through 62 is repeated except that methanol is used.

EXAMPLES 125-186

The procedure of Examples 1 through 62 is repeated except that 2-methyl-2-propanol is used.

Having described the invention in detail and by reference to preferred embodiments thereof, it will be apparent that modifications and variations are possible without departing from the scope of the invention defined in the appended claims.

Claims

WHAT IS CLAIMED IS:

1. Compositions consisting essentially of from about 0.4 to about 79.6 weight percent 1,1-dichloro-l- fluoroethane, about 0.4 to about 79.6 weight percent dichlorotrifluoroethane selected from the group consisting of l,l-dichloro-2,2,2-trifluoroethane, 1,2- dichloro-1,1,2-trifluoroethane, and mixtures thereof, and from about 5 to about 20 weight percent of alkanol having 1 to 4 carbon atoms.

2. The compositions of claim 1 consisting essentially of from about 40 to about 79.6 weight percent said 1,1-dichloro-l-fluoroethane, about 0.4 to about 40 weight percent said dichlorotrifluoroethane, and from about 5 to about 20 weight percent of said alkanol.

3. The compositions of claim 1 consisting essentially of from about 62.4 to about 79.6 weight percent said 1,1-dichloro-l-fluoroethane, about 0.4 to about 17.6 weight percent said dichlorotrifluoroethane, and from about 5 to about 20 weight percent said alkanol.

4. The compositions of claim 1 consisting essentially of from about 5 to about 15 weight percent said alkanol.

5. The compositions of claim 1 wherein said alkanol is methanol.

6. The compositions of claim 1 wherein said alkanol is 2-methyl-2-propanol.

7. The compositions of claim 1 wherein said alkanol is ethanol.

8. The compositions of claim 1 wherein said alkanol is 2-propanol.

9. A method of dewatering a non-absorbent article which comprises treating said non-absorbent article with compositions consisting essentially of from about 0.4 to about 79.6 weight percent 1,1-dichloro-l- fluoroethane, about 0.4 to about 79.6 weight percent dichlorotrifluoroethane selected from the group consisting of 1,l-dichloro-2,2,2-trifluoroethane, 1,2- dichloro-1,1,2-trifluoroethane, and mixtures thereof, and from about 1 to about 20 weight percent of alkanol having 1 to 4 carbon atoms.

10. The method of claim 9 wherein said compositions consist essentially of from about 40 to about 79.6 weight percent 1,1-dichloro-l-fluoroethane, about 0.4 to about 40 weight percent said dichlorotrifluoroethane, and from about 1 to about 20 weight percent of said alkanol.