JPH05508880A - Azeotrope-like composition of 1,1-dichloro-1-fluoroethane; ethanol; and nitromethane - Google Patents

Abstract

Azeotrope-like compositions comprising 1,1-dichloro-1-fluoroethane; ethanol; and nitromethane are stable and have utility as degreasing agents and as solvents in a variety of industrial cleaning applications including cold cleaning and defluxing of printed circuit boards and dry cleaning.

Description

[Detailed description of the invention] The present invention provides 1,1-dichloro-1-fluoroethane: ethanol: and nitromethane. The present invention relates to an azeotrope-like composition of tan. These mixtures can be mixed with various types of steam. For degreasing, cold cleaning and solvent cleaning applications, flux It is useful in applications including defluxing.

Background of the invention Vapor degreasing and solvent cleaning with fluorocarbon solvents are widely used in industry. It is widely used for degreasing and other cleaning of solid surfaces, especially complex parts and difficult-to-remove dirt. It is often used.

Vapor degreasing or solvent cleaning, in its simplest form, is a cleaning solution. It consists of aNing a room temperature object into boiling solvent vapor. condense on an object The steam provides a clean distilled solvent that washes away grease or other contaminants. Ru. If the object is simply cleaned in a liquid solvent, the final evaporation of the solvent from the object There is no residue left behind as with other cases.

Difficult-to-remove soils that require elevated temperatures to improve the cleaning action of solvents or for cleaning metal parts and assemblies effectively and quickly. For high-volume assembly line operations that require The device is operated by immersing the parts to be cleaned in a boiling solvent pool, which generally cleans the parts. Remove any loose dirt, then add to a reservoir containing freshly distilled solvent at room temperature. The part is immersed and finally the part is exposed to solvent vapor above a boiling pool and this vapor is removed. This consists of air condensing on the cleaned parts. In addition, the distilled solvent is It can also be sprayed onto the parts before final rinsing.

Vapor degreasing equipment suitable for the above operations is well known in the art. For example, Shelli U.S. Pat. Therefore, suitable steam degreasing equipment of this kind consisting of a water separator and other auxiliary equipment is indicated. I have a desk.

Cold cleaning is another application that uses multiple solvents. most calls In dry cleaning applications, dirty parts are immersed in a fluid or exposed to a solvent. Wipe with a soaked cloth or similar and air dry.

Fluorocarbon solvents, such as trichlorotrifluoroethane, are used in degreasing applications. Effective, non-toxic and non-flammable materials useful in and other solvent cleaning applications. It has become widely used in recent years. Trichlorotrioleoethane is It has been recognized that it has sufficient solvent power against bases, oils, waxes, etc.

Therefore, this includes motors, compressors, heavy metal parts, delicate precious metal parts, and printed circuits. Plates, gyroscopes, guidance equipment, equipment for spacecraft and missiles, aluminum It is widely used for cleaning system parts, etc.

The technology is based on the target fluorocarbon component, such as trichlorotritrifluoride. an azeotrope or azeotrope-like composition containing fluoroethane, further comprising: Ingredients that contribute to desired properties, such as polar functionality, increased solvency, and stability. It is intended for those containing agents. An azeotrope or azeotrope-like composition is This is desirable because it does not need to be separated during storage. This behavior is similar to that described above using these solvents. The redistilled material in the vapor degreaser is used for final rinsing and cleaning. It is desirable because it generates The distillation degreasing system thus acts as a still.

If the solvent composition does not exhibit a constant boiling point, i.e. is not azeotrope-like, the fractionation potential for undesired solvent distribution to disrupt cleaning and processing safety. There is. If the more volatile components of the solvent mixture evaporate preferentially, m-so m-, the more undesirable properties that would occur if they were not azeotrope-like. For example, metals, plastics, etc. less inertness to metal or elastomer parts, and non-flammable and toxic A mixture of altered composition will result, with increased .

The industry is currently developing new and specialized applications for steam degreasing and other cleaning applications. Novel fluorocarbon-based azeotrope-like mixtures are emerging that offer viable alternatives. Recommended. What is currently of particular interest is the complete hardware currently in use. A stratospherically safe alternative to loginated chlorofluorocarbons It is a fluorocarbon azeotrope-like mixture that is thought to be. The former is the earth suspected of causing environmental problems with respect to the ozone layer that protects the ozone layer. hydrochlorofur Orocarbons, such as 1,1-cyclo-1-fluoroethane (HCFC-1 41b) has no adverse effects on atmospheric chemistry compared to fully halogenated ones. contribution to ozone depletion and global warming due to the greenhouse effect. It was proved by a mathematical model that it is possible to ignore . HCFC-1 41b is known to be useful as a solvent. HCFC-141b is approximately 3 It has a boiling point of 2°C.

The aerosol packaging concept is a simple and cost-effective means of dispensing solvents. It has long been recognized that there is. Aerosol products must be used when the aerosol valve is opened. sufficient to drive the active ingredients, i.e., product concentrates such as solvents, out of the container when of a propellant gas or propellant gas mixture, preferably a compressed gas, which generates sufficient pressure. Rather than the liquid state, use the liquefied gas state. The propellant is normally used in most aerosol It may be in direct contact with the solvent, as in the case of barrier-type air systems. It may be separated from the solvent as in the case of sol systems.

Co-assigned U.S. Pat. No. 4,836,947 discloses 1,1-cyclo An azeotrope-like mixture of rho-1-fluoroethane and ethanol is shown. . Commonly assigned U.S. Pat. No. 4,842,764 includes 1.1-sic. An azeotrope-like mixture of Rolow 1-fluoroethane and methanol is shown. Ru. Commonly assigned U.S. Pat. No. 4,816,174 includes 1.1-di An azeotrope-like mixture of chloro-1-fluoroethane, methanol and nitromethane Compounds are shown. Same-assignee U.S. Pat. No. 4.863.630 1,1-dichloro-1-fluoroethane: dichlorotrifluoroethane: An azeotrope-like mixture of and ethanol is shown.

JP-A-1-103.686, published on April 20, 1989, No. 55-80 wt% dichlorotrifluoroethane and 20-45 wt% 1,1-dichloro An azeotropic composition of rho-1-fluoroethane is shown. JP-A-1-136.98 Publication No. 1, published on May 30, 1989, contains 25% by weight of ethanol and 2 5% by weight of 1,1-cyclo-1-fluoroethane and 50% by weight of 1,1- Cycloro 2. 2. Consisting of 75% by weight of an azeotropic composition of 2-trifluoroethane A degreasing cleaning agent is shown.

JP-A-1-136.982, published on May 30, 1989, contains ethanol. 25% by weight, and 25% by weight of 1,1-dichloro-1-fluoroethane and and 50% by weight of 1,1-dichloro-2,2,2-trifluoroethane azeotropic composition A puff abrasive cleaning agent is shown comprising 75% by weight of a powder. Japanese Patent Publication No. 1-13 Publication No. 7.25.3, published on May 30, 1989, contains 25% by weight of ethanol, and 25% by weight 1,1-dichloro-1-fluoroethane and 50% by weight 75% by weight of an azeotropic composition of 1,1-dichloro-2,2,2-trifluoroethane A resist developer consisting of the following is shown.

JP-A-1-137.259, published on May 30, 1989, contains ethanol. 15% by weight, 10% by weight of alkylbenzenesulfonic acid, and 25% by weight of 1 ．． 1-cyclo-1-fluoroethane and 50% by weight of 1,1-cyclo-2 , 2. Resist component consisting of 75% by weight of an azeotropic composition of 2-trifluoroethane A release agent is shown. JP-A-1-138.300, May 31, 1989 In the publication, 25% by weight of methanol and 25% by weight of 1,1-cyclo1 - fluoroethane and 50% by weight of 1,1-dichloro-2,2,2-triflue A flux screening agent consisting of 75% by weight of an azeotropic composition of oroethane is shown. ing.

JP-A-1-439.104, published on May 31, 1989, contains trichloro 5% by weight of ethylene, 20% by weight of ethanol, and 25% by weight of 1,1-dichloromethane. Lolo-1-fluoroethane and 75% by weight of 1,1-dichloro-2,2,2- A solvent consisting of 75% by weight of an azeotropic composition of trifluoroethane is shown. Special publication Publication No. 1-439.861, published on June 1, 1989, contains 25 parts of ethanol. % by weight, and 25% by weight of 1,1-dichloro-1-fluoroethane and 75 % by weight of 1,1-dichloro0-2. 2. Azeotropic Mi formation of 2-trifluoroethane A dry cleaning agent consisting of 5% by weight of acid is shown.

The object of the present invention is to provide liquids that are liquid at room temperature and that cannot be substantially fractionated under distillation or evaporation operations. and vapor degreasing and other solvent cleaning applications and flux removal applications. HCFC-, which is useful as a solvent for applications including dry cleaning and The object of the present invention is to provide new azeotrope-like mixtures based on 1,4lb.

Another object of the invention is to provide a new environmentally acceptable solvent for the above applications. It is to provide.

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

description of the invention According to the present invention, 1,1-dichloro-1-fluoroethane, ethanol, and A new mixture consisting of tromethane has been found. Also 1, ff-dichloro-1, -Fluoroethane: a novel azeotrope consisting of ethanol and nitromethane Compositions with similar or constant boiling points were found.

Preferably the novel azeotrope-like composition comprises an effective amount of 1,1,-dichloro-1-fluor. Consisting of oloethane: ethanol: and nitromethane. 'Effective amount used here The term ``indicates the azeotrope-like composition of the present invention when combined with other components. means the amount of each component.

Preferably the novel azeotrope-like composition is 1,1-dichloro-1-fluoroethane , ethanol: and nitromethane, 760 mmHg (101 kPa ) boils at about 32.8°C.

Preferably the novel azeotrope-like compositions contain from about 95.5 to about 99.49% by weight of 1 ．． 1-cyclo-1-fluoroethane; about 0.5 to about 3.5% by weight ethanol ; and about 0.01 to about 1.0% by weight of nitromethane, and 760 mmHg. Boiling at about 32.8°C in (LOlkPa), more preferably 760mm Hg (101kPa): approx. 32.8℃, approx. 0. Boil at 5℃.

More preferably, the azeotrope-like M composition of the present invention has a weight of about 96.1 to about 99.05 wt. % 1,1-dichloro-1-fluoroethane, approx. 9- About 3,0% by weight of E tanol, and about 0.05 to about 0.9% by weight nitromethane.

Most preferably, the azeotrope-like compositions of the present invention have a weight of about 97.1 to about 98.75 wt. % by weight of 1,1-dichloro-1-fluoroethane: from about 1,2 to about 2.0% by weight of ethane. Tanol: and about 0.05 to about 19% by weight nitromethane.

1.1-dichloro-1-fluoroethane, pure from ethanol and nitromethane Although it is unlikely that an azeotrope system of 1. ]-]dichloro1-f The composition of fluoroethaneethanol and nitromethane is in the proportions indicated in the claims. has a constant boiling point or an essentially constant boiling point and is not completely known Because of the presence or adhesion within the vapor degreasing equipment, the present invention's mixtures are The term ``azeotrope system'' is used for the substance.

As will be detailed later, all M acids within the above range may be used in specific compositions outside the above range. It is similar to an azeotrope.

Although the exact azeotropic mixture has not been determined, it was confirmed that it was within the above range.

As will be detailed later, the above ranges, regardless of where the true azeotrope lies. All compositions within are azeotrope-like, as are certain compositions outside the above ranges.

These azeotrope-like compositions are generally non-flammable liquids, i.e. Oven Cup Test Method - Flammable when tested according to ASTM D 1310-86 It was found that no points were shown.

From basic principles, the thermodynamic state of a fluid is determined from four aspects: pressure, temperature, liquid composition, and evaporation. It is determined by the gas composition, namely P-T-X-Y. The azeotrope is X and Y is a system of two or more components in which P and T have the same specific properties.

In practice, this means that the components of the mixture cannot be separated during distillation and are therefore This means that it is useful for the vapor compatibilizer cleaning described above.

For the purpose of this discussion, an azeotrope-like composition is one whose composition is similar to that of an azeotrope. behaving similarly, i.e. with constant boiling properties, or upon boiling or evaporation It shall mean having a tendency not to discriminate. Therefore their composition odor The composition of the vapor formed during boiling or evaporation is equal to the initial liquid composition. or substantially equal. Therefore, the liquid composition may change during boiling or evaporation. Even if it does occur, it will be minimal or negligible. this is a non-azeotrope-like mixture whose liquid composition changes to a substantial degree upon boiling or evaporation. should be contrasted with the composition.

Therefore, whether or not the candidate mixture is an 'azeotrope system' within the meaning of the present invention. One method for determining the predicted under the conditions (i.e. resolution - number of shelves) that The process is to distill the sample. If the mixture is non-azeotrope-like, the mixture A substance is fractionated, that is, separated into its various components, and the component with the lowest boiling point is determined first. , and so on. If the mixture is azeotrope-like, it contains all the components of the mixture. an initial quantity of a certain amount that has a constant boiling point or behaves like a single substance A fraction will be obtained. This phenomenon occurs when the mixture is non-azeotrope-like. , that is, it cannot occur if it does not behave like an azeotrope. Of course azeotropic If a mixture-like composition is distilled, for example in a vapor degreaser, a true azeotrope tend to form and concentrate.

From the above, other properties of azeotrope-like compositions include containing the same components in different proportions. , there will be a range of azeotrope-like or constant boiling compositions. these pairs All compounds are included in the term azeotrope-like or constant boiling point as used herein. shall be. For example, at different pressures, just as the boiling point of a composition changes. It is well known that the composition of azeotrope-like compositions of . Therefore, the azeotrope-like composition of A and B will vary depending on temperature and/or pressure. Outside of compositional variation, it shows a peculiar type of relationship. 1.1-dichloro-1-fluoro loethane, ethanol: and for nitromethane, these mixtures have boiling points Within the range of 32.8℃±about 0.5℃ (about 760mmHg (10LkPa)) boil). As is obvious to those skilled in the art, the boiling point of an azeotrope-like composition depends on the pressure. It will change accordingly.

The azeotrope-like M acid of the present invention can be used in various steam degreasing, cold cleaning and Useful for solvent cleaning applications including flux removal. be.

In one treatment form of the invention, the azeotrope-like composition of the invention cleans a solid surface. in any manner well known in the art, such as by dipping or spraying. or by processing using conventional degreasing equipment.

The azeotrope-like composition of the present invention applies the composition to a solid surface for cleaning the surface. When used by spraying, preferably the azeotrope-like composition contains a propellant. sprayed onto the surface using Preferably the propellant is a hydrocarbon, chlorofluorocar carbon, hydrochlorofluorocarbon, hydrofluorocarbon, dimethyl ether carbon dioxide, nitrogen, nitrous oxide, methylene oxide, air, and selected from the group consisting of a mixture of

Useful hydrocarbon propellants include isobutane, butane, propane and mixtures thereof. Compounds included: Commercially available isobutane, butane and propane can be used in the present invention. . Useful lorofluorocarbon propellants include trichlorofluoromethane (currently known in the industry as CFC-11), dichlorodifluoromethane c L L, L 2-trichloro-1-tri, known in the industry as CFC-12 fluoroethane (known in the art as CFC-1,13), and 1 ゜2-Cycloro 1. 1. 2. 2-tetrafluoroethane (in the industry, C FC-114); commercially available CFC-11, CFC-1 2, CFC-113 and CFC-114 can be used in the present invention.

Useful hydrochlorofluorocarbon propellants include dichlorofluoromethane ( HCFC-21), chlorodifluoromethane (known in the industry as HCFC-21), (known in the industry as HCFC-22), 1-chloro-1,1,2,2- Tetrafluoroethane (known in the art as HCFC-124), 1 ゜1-dichloro-2,2-difluoroethane (also known as HCFC-132a in the industry) (known as known in the art as HCFC-133), and 1-chloro-1,1 - difluoroethane (known in the art as HCFC-142b) Rare; commercially available HCFC-21, HCFC-22 and HCFC-142b It can be used clearly. HCFC-124 can be prepared by known methods, e.g. ．． 843°181 can be produced by the method taught by No. , HCFC-133 by known methods, e.g. It can be manufactured by the method taught by No. 3.

Useful hydrofluorocarbon propellants include trifluoromethane (known in the industry as (known as HFC-23), 1. 1. 2. 2-tetrafluoroe (known in the industry as HFC-134a), and 1,1-diphthalate Contains fluoroethane (known in the industry as RFC-1528), Commercially available RFC-23 and HFC-152a are used in the present invention. RFC-13 Until 4a is available in commercial quantities, HFC-134a can be produced using known methods. For example, the method taught by U.S. Pat. No. 4,851,595 It can be manufactured by More preferred propellants include hydrochlorofluorocarbons. carbons, hydrofluorocarbons and mixtures thereof. extremely preferred New propellants include chlorodifluoromethane and 1. 1. 2. 2-tetrough Contains fluoroethane.

Components of the azeotrope-like composition which is the novel solvent of the present invention 1.1-dichloro-1-phthalate Luoroethane: ethanol: and nitromethane are known substances. Preferably These substances do not introduce any adverse effects on the desired properties or constant boiling properties of the system. should be used in high enough purity to avoid

The compositions of the present invention can be supplemented to form novel azeotrope-like or constant boiling compositions. It should be understood that it can contain a certain amount. whether their composition is constant boiling or as long as they are qualitatively constant boiling and contain all essential components listed herein. are considered to be within the scope of this invention.

The invention is explained in more detail by the following non-limiting examples.

Corridor cause 1 The following describes the constant boiling point property of the mixture of the present invention under actual usage conditions in vapor phase degreasing operations. About 98.5% by weight HCFC-141b, about 1°2 % ethanol by weight, and about 0. The present invention consists of 3% by weight of nitromethane. Loaded with preferred mixture. Evaluate this mixture for its constant boiling or non-separating properties. I valued it. The vapor phase degreasing equipment used was a small water-cooled three-tank vapor phase degreasing equipment. This is a comparable system to current models that provides the most demanding solvent separation behavior testing. It corresponds to the structure. In detail, the degreasing equipment used to develop the present invention was equipped with two overflow rinse basins and one boiling basin. .

The boiling liquid sump and still are electrically heated and each has a low level cut-off switch. I was prepared. The solvent vapor in both the degreaser and distiller is water-cooled stainless steel. Condensed on a steel coil. The still was fed by gravity from the boiling liquid sump. distillation Condensate from the vessel was also returned by gravity to the first rinse reservoir. This unit The capacity of the tank was approximately 1.5 gallons. This degreasing equipment is a degreaser commonly used in commercial equipment. It was very similar to the device.

Condensate sump containing refluxing solvent charge and clear condensate from the still, condensate Working fluid reservoir containing overflow from the fluid reservoir, overflow from the working fluid reservoir The boiling liquid sump, which brings the flow to the boiling point of the mixture, and the composition in the distiller, - Measured using an Elmer Sigma Type 3 gas chromatograph. In all reservoirs The temperature of the liquid was measured by a thermocouple temperature measuring device of ±0. Monitored at 2°C. The reflux is approx. The composition of the boiling liquid sump and condensate sump continued for 30 hours, and the composition of the boiling liquid sump and condensate sump was I monitored it. The maximum concentration difference between reservoirs for any mixture component is ± the mean value. If 2 sigma, the mixture was considered constant boiling or non-separable. Sig m is the unit of standard deviation, and commercially available “azeotrope-like” vapor phase degreasing solvents decrease over time. It exhibits a compositional variation of at least ±2 sigma, and yet has extremely satisfactory non-separating properties. Based on observations of the performance of numerous vapor phase degreasing devices, the present invention has a purifying behavior. This is the experience they have gained.

If the mixture is not azeotrope-like, the high-boiling components will concentrate very quickly in the still. and the rinse fluid will decrease from the sump. This didn't happen. Also, each liquid reservoir The concentration of each component within the solution remained well within ±2 sigma. These results indicate that the present invention compositions that do not segregate in any type of large commercial vapor phase degreasing equipment; Therefore, potential safety, performance and handling issues will be avoided. and Preferred compositions tested were tested according to the recommended method ASTM D 1310- It was also found that it did not have a flash point according to 86 (tag oven cup). Each reservoir The composition of the solution is shown in Table I below.

Stability test of composition in degreasing equipment condensate sump initial ”L 24 hours 48 hours HCFC-141b 98.5 98.5 98.6 Ethanol 1.2 1. 3 1.3 Nitromethane 0.3 0.1 0.1 Temperature ('C) -23,222,5 Barometer pressure (mmHg) -748,8745,5 (kPa) (100) ( 99) boiling liquid reservoir initial Composition 24 hours 48 hours HCFC-141b 98.5 98.2 98.1 Ethanol 1.2 0. 9 0.9 Nitromethane 0.3 0.8 0.9 Temperature (℃) 32. 3 32. 4 Barometer pressure (mmHg) -748,8745,5 Temperature ('C) 32. 8 32. 9 Pressure 60mmHg Corrected to (101kPa) Haruan Book Su Example 1 is repeated except that about 97.7% by weight HCFC-14 is added to the vapor phase degreaser. 1b1 about 2.0% by weight of ethanol, and about 0.1% by weight of ethanol. 3% by weight nitromethane? Other preferred mixtures of the invention were loaded.

If the mixture is not azeotrope-like, the high-boiling components will concentrate very quickly in the still. and the rinse fluid will decrease from the sump. This didn't happen. Also, each liquid reservoir The concentration of each component within the solution remained well within ±2 sigma. These results indicate that the present invention compositions that do not segregate in any type of large commercial vapor phase degreasing equipment; Therefore, potential safety, performance and handling issues will be avoided. and Preferred compositions tested were tested according to the recommended method ASTM D 1310- It was also found that it does not have a flash point according to 86 (tag open cup). Each reservoir The composition of the solution is shown in Table II below.

Table II Stability test of composition in degreasing equipment condensate sump initial Composition 24 hours 48 hours HCFC-141b 97.7 98.0 91.0 Ethanol 2.0 1. 8 L8 Nitromethane 0.3 0.1 0.1 temperature 1f (“C) 21. 3 21. 3 barometer pressure (mmHg) -746,4753,0 (kPa) (99) ( 100) boiling liquid reservoir initial Composition 24 hours 48 hours HCFC-141b 97.7 96.5 96.0 Ethanol 2.0 2. 7 3.0 Nitromethane 0.3 0.8 0.9 Temperature ('C) 31. 9 32. 6 Barometer pressure (mmHg) -746,4753,0 (kPa) (99) (1 00) Temperature ('C) 32. 4 33. 1 pressure 60mmHg Corrected to (101kPa) Example 3 Examples of this include 1,1-cyclo-1-fluoroethane:ethanol: and nitro The presence of a constant boiling point or azeotrope-like composition of methane is confirmed by distillation. Ru. This also indicates that these mixtures do not fractionate during distillation.

5-shelf Olders with cold water condensing automatic liquid separation head haw) A distillation column was used in this example. Table III below is used as the starting material for this distillation column. The amounts of HCFC-141b, ethanol, and nitromethane were loaded.

Each composition was heated under full reflux for approximately 1 hour to ensure equilibration. This distillation A flow ratio of 5:1 was used. Approximately 50% of the initial charge material is added to four similar amounts of overfill. was collected in the de-distillate fraction. The composition of these fractions was determined by gas chromatography. analyzed. The mean and overhead temperatures of the fractions account for the uncertainties associated with measuring composition. is extremely constant within the range of Indicate that you are a kind person.

Table 12 Starting materials (wt%) Distillate composition (wt%) boiling point Boiling point Barometer pressure 760-s+Hg (101kPa) Example -(Go; No- Corrected to Horin fig (kPa) 3 30, 8 740. 87 (99) 3 1. 6 From the above examples, other constant boiling point or essentially constant boiling point mixtures of the same components It is obvious that those skilled in the art can easily confirm the above-described method. At constant boiling point No attempt has been made to fully elucidate the compositional cycle and determine its outer limits. Current No manufacturer shall purchase any other constant boiling point or essentially constant boiling point mixture containing the same components. can be easily confirmed.

Example 4 Performing performance tests to evaluate the solvent properties of the azeotrope-like compositions of the present invention . Specifically, the azeotrope-like composition of Example 1 according to the present invention was used as a solvent to The genus coupon was cleaned. By staining metal coupons with various oils 1, the presence of these oils to 93°C to partially simulate the temperatures reached when machining and polishing under Heated.

The metal coupons thus treated were degreased in a simulated vapor phase degreaser. condenser is held around the lip of the cylindrical vessel to condense the solvent vapor, which is then Drip into container. The metal coupon is kept in the solvent vapor and depending on the oil chosen, 1 Rinse for a period of 5 seconds to 2 minutes.

The cleaning ability of the azeotrope-like composition is determined by visual inspection of the coupon. Example 1 Azeotrope-like compositions of are effective as solvents.

Example 5 Example 4 is repeated using the azeotrope-like composition of Example 2. Azeotrope mixture of Example 2 Compound-like compositions are effective as solvents.

Example 6 Example 4 is repeated using the azeotrope-like composition of Example 3. Azeotrope of Example 3 Compound-like compositions are effective as solvents.

Example 7 A 6 oz. 3 piece aerosol can is used. Conducted on tared and weighed aerosol cans Weigh out the azeotrope-like composition of Example 1. Tie the can to eliminate air inside the container. After purging with trafluoroethane, mechanically crimp the valve onto the can.

Liquid chlorodifluoromethane is then added through the valve using a pressure billet.

It has an area of 37.95 square inches, with densely integrated immersion sockets, resistors and A printed circuit board with capacitors and capacitors is improvised using flow soldering. Pre-clean by rinsing with water. Then the circuit board is treated with 7 lux. However, Hollis TDL flow soldering is performed by a machine.

Next, a printing cycle is carried out using an aerosol can filled with the azeotrope-like composition described above. Clean the road board by spraying. Check the cleanliness of the circuit board visually and Tested using an omega meter that measures oxidative contamination. Azeotrope-like group of Example 1 The composition is particularly useful as a solvent for spray cleaning applications.

Example 8 Example 7 is repeated, but using the azeotrope-like composition of Example 2. Example 2 Azeotrope-like compositions are particularly useful as spraying solvents for cleaning applications. Ru.

Example 9 Example 7 is repeated, but using the azeotrope-like composition of Example 3. Example 3 Azeotrope-like compositions are particularly useful as spraying solvents for cleaning applications. Ru.

The azeotrope-like compositions of the present invention include: to suppress decomposition of the composition; to react with unwanted decomposition products; and/or to prevent corrosion of metal surfaces. To stop this, an inhibitor is added. The present invention includes the following 1! ! f inhibitor Any or all can be used: epoxy compounds such as propylene oxides: ethers, e.g. 1,4-dioxane: unsaturated compounds, e.g. 1,4-Butynediol: acetal or ketal, e.g. dipropoxy Methane, ketones such as methyl ethyl ketone; alcohols such as t- Amyl alcohol: esters, such as triphenyl phosphite: and amino such as triethylamine. Other suitable inhibitors will be apparent to those skilled in the art.

Although the invention has been described in detail with reference to its preferred form, the present invention has been described in detail with reference to its preferred form. It will be obvious that changes and modifications may be made without departing from the scope of the invention. cormorant.

abstract 1.1-dichloro-1-fluoroethane: from ethanol: and nitromethane The azeotrope-like composition is stable and can be used as a vapor degreaser and as a cold cream. cleaning and dry cleaning of printed circuit boards It is useful as a solvent in a variety of industrial cleaning applications, including cleaning.

Submission of translation of written amendment (Article 184-8 of the Patent Act)

Claims (14)

[Claims] 1. an effective amount of 1,1-dichloro-1-fluoroethane; ethanol; and nitrate. An azeotrope-like composition consisting of lomethane. 2. about 95.5 to about 99.49% by weight of 1,1-dichloro-1-fluoroethane , about 0.5 to about 3.5% by weight ethanol, and about 0.01 to about 1.0% by weight. 2. The azeotrope-like composition of claim 1, comprising nitromethane. 3. about 96.1 to about 99.05% by weight 1,1-dichloro-1-fluoroethane , about 0.9 to about 3.0% ethanol, and about 0.05 to about 0.9% by weight. 2. The azeotrope-like composition of claim 1, comprising nitromethane. 4. about 97.1 to about 98.75% by weight 1,1-dichloro-1-fluoroethane , about 1.2 to about 2.0% by weight of ethanol, and about 0.05 to about 0.9% by weight. 2. The azeotrope-like composition of claim 1, comprising nitromethane. 1,1-dichloro-1- boils at about 32.8°C at 5.760 mmHg. An azeotrope-like composition consisting of fluoroethane, ethanol and nitromethane. 6. about 95.5 to about 99.49% by weight of 1,1-dichloro-1-fluoroethane , about 0.5 to about 3.5% by weight ethanol, and about 0.01 to about 1.0% by weight. 6. The azeotrope-like composition of claim 5, comprising nitromethane. 7. about 96.1 to about 99.05% by weight of 1,1-dichloro-1-fluoroethane , about 0.9 to about 3.0% ethanol, and about 0.05 to about 0.9% by weight. 6. The azeotrope-like composition of claim 5, comprising nitromethane. 8. about 97.1 to about 98.75% by weight 1,1-dichloro-1-fluoroethane , about 1.2 to about 2.0% by weight ethanol, and about 0.05 to about 0.9% by weight. 6. The azeotrope-like composition of claim 5, comprising nitromethane. Boiling at about 32.8°C ± about 0.5°C at 9.760 mmHg. The azeotrope-like composition according to clause 5. 10. Treating a solid surface with the azeotrope-like composition according to claim 5. A method of cleaning a solid surface comprising: 11. Treating a solid surface with the azeotrope-like composition according to claim 6. A method of cleaning a solid surface comprising: 12. Treating a solid surface with the azeotrope-like composition according to claim 7. A method of cleaning a solid surface comprising: 13. Treating a solid surface with the azeotrope-like composition according to claim 8. A method of cleaning a solid surface comprising: 14. Treating a solid surface with the azeotrope-like composition according to claim 9. A method of cleaning a solid surface comprising: