JPH07331290A - Aerosol composition for cleaning braking device - Google Patents

Abstract

PURPOSE:To provide an aerosol composition having a specific composition, especially suitable for the cleaning of a rotor such as automotive disk brake, etc., exhibiting excellent cleaning effect without destructing global environment and having low toxicity, excellent dryability and low odor. CONSTITUTION:This aerosol composition contains (A) a stock liquid composed of (a) 35-90 pts.wt. of a 6C naphthenic hydrocarbon (preferably cyclohexane), (b) 5-10 pts.wt. of a 9-10C saturated hydrocarbon having a boiling point of 150-179 deg.C (preferably a mixture of naphthenic hydrocarbon and isoparaffinic or n-paraffinic hydrocarbon) and (c) 1-10 pts.wt. of a 1-3C aliphatic monohydric alcohol (preferably ethanol, etc.) and (B) a propellant (preferably liquefied petroleum gas). The weight ratio of A:B is preferably 90:10 to 60:40.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aerosol composition for cleaning a brake device, which is suitable as a cleaning agent for a rotating body of a disc brake or a drum brake device of an automobile and which is excellent in safety and cleanability.

[0002]

2. Description of the Related Art A friction brake device, particularly an automobile friction brake device, usually has a structure in which a brake shoe having a brake lining acts on a rotating body such as a brake disc or a brake drum as a brake element. Normally, asbestos is used for this brake lining, and as the brake is used, the asbestos becomes dust and adheres to the brake discs and the like, which eventually adversely affects braking of the brake.

As a method for removing the asbestos dust, the following has been conventionally adopted. 1. High pressure air from a compressor is blown to scatter asbestos. 2. Rinse with water. 3. Aromatic hydrocarbons such as toluene and xylene, hydrocarbons having 6 to 10 carbon atoms such as aliphatic saturated hydrocarbons such as n-hexane and isooctane, and aliphatic monohydric alcohols and aliphatic dihydric alcohol mono-lower alkyl ethers The mixture is washed as a washing liquid (Japanese Patent Publication No. 58-44118). 4. A mixture of chlorinated aliphatic hydrocarbon such as 1,1,2-trichloroethane and an aliphatic monohydric alcohol or an aliphatic dihydric alcohol mono-lower alkyl ether is washed as a washing liquid (Japanese Patent Publication No. 58-44118). . 5. A mixture of freon such as freon 113 and an aliphatic monohydric alcohol is washed as a washing liquid.

[0004]

In the method of 1, the asbestos dust is scattered, and it is said that if the asbestos dust pierces the inner wall of the lungs of the human body, the carcinogenicity is increased, which is a problem in occupational health. . Therefore, the above-mentioned method 2 has been proposed, but this method has a problem that the working time becomes extremely long.

Therefore, the methods 3, 4, and 5 have been proposed to solve these problems. However, in the above methods 3 and 4, there are many cases in which there are problems in the working environment, such as the substances used in the cleaning liquid being subject to the organic solvent poisoning prevention rule. Further, if a composition that clears this problem is used, it often takes 4 to 10 minutes or more for drying, and in recent years, the brake device is immediately assembled after cleaning the brake device, which is a very problematic task. Further, the substances used in these methods often have a peculiar odor, which causes a problem in workability.

Further, although the above-mentioned problems have been solved by the above-mentioned method 5, it was discovered from the results of recent research that chlorofluorocarbon released into the atmosphere destroys the ozone layer, and the production amount is stepwise. Have been reduced. 1,1,2-Trichloroethane and the like used in the above-mentioned method 4 have the same problem and have been reduced in the same manner. Therefore, a new cleaning device for a brake device that solves these problems is desired.

It is an object of the present invention to prevent the scattering of asbestos dust or the like adhering to the rotating body of the brake disc or the brake drum in the braking device, and to adjust the drying speed, to make the ozone layer safe, simple and quick. It is an object of the present invention to provide an aerosol composition for cleaning a brake device, which can be washed without destroying the above, and which eliminates the above-mentioned drawbacks in the known art.

[0008]

The aerosol composition for cleaning a brake device according to the present invention is a saturated naphthenic hydrocarbon having 6 to 6 carbon atoms in an amount of 35 to 90 parts by weight, a carbon number of 9 to 10 and a boiling point of 150 to 179 ° C. It is characterized by comprising a propellant and a stock solution comprising 5 to 10 parts by weight of a hydrocarbon and 1 part by weight or more and less than 10 parts by weight of an aliphatic monohydric alcohol having 1 to 3 carbon atoms.

The naphthenic hydrocarbon having 6 carbon atoms which is the main component of the brake device cleaning aerosol composition of the present invention is
It has the following features. 1. Does not correspond to the organic solvent poisoning prevention regulations and has little effect on the human body. 2. Does not destroy the ozone layer. 3. The odor is weak. 4. High drying speed.

However, the naphthenic hydrocarbons alone have a low flash point (for example, -20 ° C. for cyclohexane), a higher melting point that belongs to Daiichi Petroleum (for example, 6.5 ° C. for cyclohexane), and are outdoors in winter. Then there is the drawback of freezing. Examples of the naphthenic hydrocarbon having 6 carbon atoms used in the present invention include cyclohexane and methylcyclopentane, preferably cyclohexane.

If a naphthene hydrocarbon having 5 or less carbon atoms is used instead of the naphthene hydrocarbon, the naphthene hydrocarbon having 7 or more carbon atoms has high volatility, a low flash point and is dangerous in handling. When used, the drying rate becomes low depending on the composition ratio with the mixed solvent. The saturated hydrocarbon having 9 to 10 carbon atoms and the boiling point of 150 to 179 ° C. used in the present invention has the same characteristics as the above 1 to 3 like the above-mentioned naphthenic hydrocarbon, and further belongs to the second petroleum group. Many of them have the property of being highly soluble in oils and fats. However, the saturated hydrocarbon alone has a drawback that the drying rate is low.

The carbon number used in the present invention is 9 to 10 and the boiling point is 150.
As saturated hydrocarbons having a temperature of up to 179 ° C, there are isoparaffinic hydrocarbons having 9 to 10 carbon atoms, normal paraffinic hydrocarbons, and naphthene hydrocarbons, and particularly naphthene hydrocarbons and isoparaffinic hydrocarbons or normal paraffin hydrocarbons. A mixture with hydrogen is preferred. If an aromatic hydrocarbon is used instead of the saturated hydrocarbon, it causes deterioration of the rubber and is subject to the organic solvent poisoning prevention rule.

When a saturated hydrocarbon having 8 or less carbon atoms is used instead of the saturated hydrocarbon, the drying speed becomes too fast, and when a saturated hydrocarbon having 11 or more carbon atoms is used, the drying speed becomes slow. Examples of the aliphatic monohydric alcohol having 1 to 3 carbon atoms used in the present invention include methanol, ethanol, normal propyl alcohol, and isopropyl alcohol. The composition obtained by blending these aliphatic monohydric alcohols with the saturated hydrocarbon is a mineral. System grease and synthetic oil are well dissolved, and the content of the aliphatic monohydric alcohol in ethanol, normal propyl alcohol and other organic solvents is 5
If less than% isopropyl alcohol is used, it is not regulated by the organic solvent poisoning prevention rule.

In the present invention, 35 to 90 parts by weight of the naphthenic hydrocarbon, 5 to 10 parts by weight of the saturated hydrocarbon and 1 part by weight or more of the aliphatic monohydric alcohol are used as a stock solution of the aerosol composition for cleaning a brake device. An undiluted solution of less than 1 part by weight is used to provide an aerosol composition for cleaning a brake device, which is excellent in safety and cleanability. If the blending ratio of the naphthenic hydrocarbon is less than the lower limit, sufficient detergency cannot be exerted, and if it exceeds the upper limit, it freezes outdoors in winter and becomes unusable. If the blending ratio of the saturated hydrocarbon is less than the lower limit, it freezes outdoors in winter, and if it exceeds the upper limit, sufficient detergency cannot be exhibited. When the blending ratio of the aliphatic monohydric alcohol is less than the lower limit, the cleaning liquid has rubber lubricity, and the cleaning power for brake fluid becomes low, and when the upper limit is exceeded, the cleaning liquid has tar-like substances. Degreasing ability becomes insufficient.

The mixing ratio of each component in the stock solution is preferably 55 to 90 parts by weight of the naphthenic hydrocarbon, 5 to 10 parts by weight of the saturated hydrocarbon and 3 to 9 parts by weight of the aliphatic monohydric alcohol. . In the brake device cleaning aerosol composition of the present invention, the weight ratio of the stock solution to the propellant is
It is preferably 95: 5 to 40:60. If the mixing ratio of the undiluted solution is less than the lower limit, there are many splatters by injection,
If the adhesion of the undiluted solution becomes poor and exceeds the upper limit, a strong injection pressure by the propellant cannot be obtained. More preferably, the weight ratio of the stock solution to the propellant is 90:10 to 60:40.

As the propellant component, liquefied petroleum gas, dimethyl ether, tetrafluoroethane (HFC-134a), monochlorodifluoromethane (HCFC-22), monochlorodifluoroethane (HCFC-142b), dichloromonofluoroethane
Liquefied gases such as (HCFC-141b) and difluoroethane (HFC-152a); compressed gases such as carbon dioxide gas, nitrogen gas and laughing gas can be mentioned, and these may be used alone or as a mixture.

[0017]

EXAMPLES The present invention will be described in more detail below with reference to examples and comparative examples, but the scope of the present invention is not limited to these examples. The test methods performed for the following examples and comparative examples are as follows.

(1) Solubility 50 ml of stock solutions of various compositions shown in Examples and Comparative Examples are placed in an Erlenmeyer flask, 5 ml of the oils shown below are added to each stock solution, and shaken to visually check the compatibility. Observe. Judgment Clearly compatible ○ Comparable but turbid △ Not completely compatible × Test specimen 1) Engine oil mineral 2) Engine oil synthetic oil 3) Brake fluid 4) Gear oil

(2) Effect of stock solution on rubber (rubber swelling property) A test piece of rubber was weighed 30 × 30 × 2 mm, and the test piece was placed in a stock solution of various aerosol compositions shown in Examples and Comparative Examples at room temperature. Immerse at (25 ° C.) for 1 hour, take out after that, wipe the stock solution completely with paper, weigh the test piece, and calculate the rate of weight change by the following formula. X = (B−A) / A × 100, where X: weight change rate A: weight of test piece before immersion B: weight of test piece after immersion 1) Natural rubber 2) Styrene-butadiene rubber (SBR) ) 3) Acrylonitrile-butadiene rubber (NBR)

(3) Effect of undiluted solution on plastic (plastic swelling property) The same as (2) except that the following plastic is used instead of the rubber of (2). Specimen 1) Polyethylene 2) Polypropylene 3) Vinyl chloride resin

(4) Dryability With the lining surface of the brake lining facing upward, 20 g of various aerosol compositions are uniformly applied over the entire surface of the lining. After that, the time until the entire surface is dried is measured.

(Examples 1 to 4 and Comparative Examples 1 to 3) Cleaning agents having the following compositions were prepared. (Example 1) Cyclohexane 68 parts by weight Naphthesol-LL 6 parts by weight (Nippon Petrochemical Co., Ltd., mixture of naphthene hydrocarbons having 9 to 10 carbon atoms and isoparaffin hydrocarbons, boiling point 150)
~ 179 ℃) Solmix AP-7 6 parts by weight (Nippon Kasei Co., Ltd., a mixture of ethanol, normal propyl alcohol, isopropyl alcohol; isopropyl alcohol content 4.9%) Liquefied petroleum gas 20 parts by weight

Example 2 Cyclohexane 76 parts by weight Naphthesol-LL 7 parts by weight Solmix AP-7 7 parts by weight Carbon dioxide 10 parts by weight

(Example 3) Cyclohexane 72 parts by weight Naphthesol-LL 7 parts by weight Solmix AP-7 6 parts by weight Liquefied petroleum gas 10 parts by weight Carbon dioxide gas 5 parts by weight (Example 4) Cyclohexane 57 parts by weight Naphthesol-LL 5 Parts by weight Solmix AP-7 3 parts by weight Tetrafluoroethane 35 parts by weight

Comparative Example 1 Toluene 25 parts by weight Isopropyl alcohol 55 parts by weight Liquefied petroleum gas 20 parts by weight

(Comparative Example 2) 1,1,2-trichloroethane 65 parts by weight Solmix AP-7 24 parts by weight Carbon dioxide gas 11 parts by weight (Comparative Example 3) Toluene 50 parts by weight Xylene 34 parts by weight Liquefied petroleum gas 10 parts by weight Carbon dioxide 6 parts by weight

[0027]

[Table 1]

[0028]

Industrial Applicability The aerosol composition for cleaning a brake device according to the present invention has an excellent cleaning effect, and since it uses a non-chlorine solvent, it does not damage the global environment, has low toxicity, and protects the working environment. However, it achieves a drying property comparable to that of a cleaning agent that uses a chlorine-based solvent, does not deteriorate rubber or plastic, has a low odor, and its cleaning effect is liquefied petroleum gas, which is an aerosol propellant, It is further enhanced by the strong injection pressure of carbon dioxide gas.

Claims (8)

[Claims] 1. 35 to 90 parts by weight of a naphthenic hydrocarbon having 6 carbon atoms, 5 to 10 parts by weight of a saturated hydrocarbon having 9 to 10 carbon atoms and a boiling point of 150 to 179 ° C., and an aliphatic having 1 to 3 carbon atoms. An aerosol composition for cleaning a brake device, comprising a stock solution of 1 part by weight or more and less than 10 parts by weight of a monohydric alcohol and a propellant. 2. The aerosol composition for cleaning a brake device according to claim 1, wherein the naphthenic hydrocarbon having 6 carbon atoms is cyclohexane. 3. The brake according to claim 1, wherein the saturated hydrocarbon having 9 to 10 carbon atoms and a boiling point of 150 to 179 ° C. is a mixture of a naphthene hydrocarbon and an isoparaffin hydrocarbon or a normal paraffin hydrocarbon. Aerosol composition for device cleaning. 4. The brake device cleaning aerosol composition according to claim 1, wherein the aliphatic monohydric alcohol is methanol, ethanol, normal propyl alcohol and / or isopropyl alcohol. 5. The aerosol composition for cleaning a brake device according to claim 1, wherein the propellant is a liquefied gas or a compressed gas. 6. The liquefied gas is liquefied petroleum gas, dimethyl ether, tetrafluoroethane, monochlorodifluoromethane, monochlorodifluoroethane, dichloromonofluoroethane and / or difluoroethane.
An aerosol composition for cleaning a brake device as described above. 7. The aerosol composition for cleaning a brake device according to claim 5, wherein the compressed gas is carbon dioxide gas, nitrogen gas and / or laughing gas. 8. The weight ratio of undiluted solution and propellant is 95: 5 to 40:60.
The aerosol composition for cleaning a brake device according to any one of claims 1 to 7.