JPH08151599A - Composition for finish washing and method for finish washing - Google Patents

Abstract

PURPOSE: To obtain the subject composition, containing hexamethyldisiloxane of controlled purity as one of principal components, excellent in safety, permeability and drying properties without any corrosiveness for materials, capable of providing clean surfaces without any stains, residues, etc., after drying and useful for cleaning optical elements, electronic parts, etc. CONSTITUTION: This composition contains hexamethyldisiloxane as one of principal, components and has <50ppm content of dodecamethylpentasiloxane without substantially containing a compound having a higher boiling point than that of the dodecamethylpentasiloxane. For example, hexamethyldisiloxane commercially available for general industrial uses is distilled and purified with a still having 30 theoretical plate number to provide the purified hexamethyldisiloxane. The resultant purified hexamethyldisiloxane in an amount of 63.3-64.3 pts.wt. is stirred and mixed with 35.7-36.7 pts.wt. first class grade reagent ethanol to afford 100 pts.wt. composition.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention can be applied to optical elements such as glass lenses and plastic parts, mold parts, metal parts, ceramic parts, electronic parts and the like for hand-wiping cleaning and final finishing cleaning so that stains, residues, etc. TECHNICAL FIELD The present invention relates to a finish cleaning composition and a finish cleaning method, which can provide a clean surface without scratches. In particular, the present invention relates to a finish cleaning composition and a finish cleaning method that do not require the use of CFCs.

[0002]

2. Description of the Related Art Generally, optical elements and molded parts are subjected to simple cleaning by hand-wiping with a solvent-impregnated cotton paper or cloth as a final finishing cleaning for removing fingerprints, dust, and the like after manufacturing. On the other hand, industrial parts such as optical elements, electric parts, and electronic parts are subjected to precision cleaning, and after this precision cleaning, they are dried using a drying solvent. As a solvent used for such washing and drying treatment, 1,1,2-trichloro-1,
2,2-trifluoroethane (Freon 113) is used. The chlorofluorocarbon 113 is non-flammable, has low toxicity to living organisms, and has a fast drying rate. In addition, it has a selective dissolution characteristic that it does not corrode polymer materials such as plastic and rubber but dissolves fats and oils. Therefore, it has been widely used as an industrial washing and drying solvent. On the other hand, a large number of mixed solvents and azeotropic compositions have been developed to reduce the amount of CFC 113 used and to degrease factories.
For example, JP-A-59-17328 describes that a solvent obtained by mixing Freon 113, trichloroethane and dichloromethane is effective for degreasing. Further, JP-A 1-318094 discloses a solvent in which CFC 113, isopropyl alcohol and methyl ethyl ketone are mixed, and JP-A-2-289693 discloses.
An azeotropic composition of dichlorotetrafluoropropane (CFC 234) and a defatted lower alcohol such as ethanol is described. Furthermore, the use of aliphatic lower alcohols such as isopropyl alcohol and ethanol, ketones such as acetone, and ethers has been studied.

[0003]

However, the CFC 11
Since perhaloethanes such as 3 are chemically stable, they have a long life in the troposphere and diffuse to reach the stratosphere.
Here, it is decomposed by sunlight to generate halogen radicals. This halogen radical causes a chain reaction with ozone in the ozone layer and destroys the ozone layer, so that it is necessary to reduce the use of these. Therefore, as described above, we are trying to reduce the usage amount by developing a mixed solvent of CFC 113 and an organic solvent other than perhaloethane, but since CFC 113 is essential, the usage amount is above a certain level. There is a problem that cannot be reduced. Further, as described above, a mixed solvent with CFCs 234, which has a relatively low ozone layer destructiveness as compared with CFC 113, has been developed, but the destruction of the ozone layer cannot be completely eliminated. On the other hand, a mixed solvent using an aliphatic lower alcohol type, a ketone type, or an ether type has many compounds that are highly toxic to the living body, and therefore has a problem of adversely affecting the health of workers during use.

In addition, when an organic solvent such as a CFC alternative solvent or an alcohol is applied to finish cleaning and precision cleaning as described above, an organic solvent that is not strictly controlled in purity has a high boiling point component with poor volatility. It is often contained, and the high boiling point remains in the cleaning application, causing spots and the like after drying. Therefore, an organic solvent whose purity is not strictly controlled cannot be used for finish cleaning.

The present invention has been made in consideration of the above circumstances, and is a composition for finish cleaning, which is excellent in safety to living organisms without destroying the ozone layer and can be used for final finish cleaning, and An object is to provide a finish cleaning method. In addition, the present invention has the above-mentioned characteristics, and also has excellent cleaning properties and drying properties, and particularly finishing cleaning by hand-wiping of various industrial parts that require a highly cleaned surface and further finishing that can be suitably used for drying It is an object to provide a cleaning composition and a finishing cleaning method.

[0006]

The finish cleaning composition of the present invention comprises hexamethyldisiloxane as a main component and a dodecamethylpentasiloxane content of 50 p.
It is less than pm and does not substantially contain a high boiling point compound than dodecamethylpentasiloxane. Also,
The method of the present invention comprises hexamethyldisiloxane as a main component and a dodecamethylpentasiloxane content of 50 pp.
It is less than m, and the object to be cleaned is immersed in a cleaning composition that does not substantially contain a high boiling point compound than dodecamethylpentasiloxane, and after cleaning, it is pulled up. Furthermore, in the method of the present invention, the above-mentioned cleaning composition is soaked in a hand-wiping tool such as a hand-wiping cleaning cloth or a hand-wiping cleaning paper, and the object to be cleaned is wiped up. Here, the state of “substantially not containing” means a concentration that is not detected in gas chromatography.

Generally, siloxane compounds are known to be inactive substances in the living body, and since hexamethyldisiloxane used in the present invention is also a siloxane compound, it is similarly inactive to living organisms. Therefore, it is highly safe with almost no toxicity to the human body. Further, this hexamethyldisiloxane has almost no effect on solid materials such as plastics, rubbers, metals, glasses, and ceramics, and even if applied to cleaning, the materials are not damaged. Table 1
Shows the results of immersing test pieces of various materials (size 5 × 50 × 2 mm, the surface of which is mirror finished) in 200 cc of hexamethyldisiloxane at room temperature for 2 hours. "○" in the evaluation indicates a weight change of less than 1%. Further, in the visual observation of each test piece 2 hours after immersion in Table 1 by a stereoscopic microscope,
There was no change from before immersion, and no haze, cracks, discoloration, etc. were observed.

[0008]

[Table 1]

Hexamethyldidyloxane is soluble in oils and fats such as cutting oils and hand oils, and therefore has a cleaning action by dissolution on oils and fats which are stains adhering to the object to be washed. Is obtained. In addition, hexamethyldisiloxane has a low surface tension of about 16 dyne / cm and a low viscosity of 0.65 cSt, so it has high permeability, and can be applied to cleaning even a portion requiring permeability such as a narrow gap. Hexamethyldisiloxane has a low boiling point of 100 ° C and a latent heat of vaporization of about 40 cal / g, and is highly volatile. It can be carried out. The hexamethyldisiloxane used in the final cleaning composition of the present invention is one in which a compound having poor volatility such as dodecamethylpentasiloxane is removed by a purification treatment such as distillation / rectification and / or adsorption with activated carbon. . That is, the content of dodecamethylpentasiloxane, which has poor volatility, should be 5
It has a high purity of less than 0 ppm and substantially does not contain a substance having a boiling point higher than that of dodecamethylpentasiloxane.
For this reason, even after drying at room temperature after cleaning, there is no component remaining on the surface of the object to be cleaned, so that it is possible to obtain a highly accurate clean surface free from stains and residues.

The following will show how a trace amount of poorly volatile components affect the finish state after finish cleaning. 0.003% of dodecamethylpentasiloxane was added to hexamethyldisiloxane having a purity of 99.999% or more obtained by a highly accurate distillation apparatus having a theoretical plate number of 30 or more.
Add 1% by weight each, soak and pull up the slide glass with clean stains on each concentration solution, dry it at room temperature and immediately observe the surface with a binocular stereomicroscope. The exhalation test which evaluates was carried out. The results are shown in Table 2. In the evaluation, in each evaluation method, no stains / residues were observed, “◯”, slightly recognized stains were evaluated as “Δ”, and clear ones were evaluated as “×”.

[0011]

[Table 2]

Table 3 shows the results when the concentration of tetradecahexasiloxane, which has a higher boiling point than dodecamethylpentasiloxane, was changed by the same procedure. From this result, the concentration of dodecamethylpentasiloxane was 50p.
The generation of spots / residues started to be slightly observed at pm or more, and the formation of spots / residues was observed when a small amount of tetradecamethylhexasiloxane having a higher boiling point than dodecamethylpentasiloxane was contained. This shows that in order to obtain a clean surface free from stains and residues, the concentration of dodecamethylpentasiloxane should be less than 50 ppm, and components having a boiling point higher than this should not be contained.

[0013]

[Table 3]

As described above, the finish cleaning composition of the present invention is highly safe for the human body and is made of plastic,
It can wash various materials such as metal, glass and ceramics with almost no effect, has excellent penetrability and dryness, and has high precision washing without stains and residues after drying. It becomes possible to obtain the surface.

[0015]

[Example 1] Glass grinding processing oil (manufactured by Yushiro Chemical Co., Ltd.,
20m after centering with the product name Yusilon CG)
m-diameter glass lens (glass material FSL5 made by OHARA CORPORATION)
Was washed in each tank by the washing process shown in FIG. 1 for 3 minutes / finally, after finally permeating into hexamethyldisiloxane, it was pulled up and dried at room temperature. Here, in the water-based cleaning agent,
Product name EE-11 containing nonionic surfactant as main component
10 (manufactured by Olympus Optical Co., Ltd.) diluted 16 times and an alkaline water-based detergent, trade name EE-112
0 (manufactured by Olympus Optical Co., Ltd.) was diluted 32 times, and pure water having an electric resistance of about 1 MΩ was used. Also, 2-propanol (IPA) for water replacement
Used a general industrial grade. The hexamethyldisiloxane used here was obtained by distilling and refining a commercially available product for industrial use with a highly accurate distillation machine. When this distillation-purified hexamethyldisiloxane was analyzed by gas chromatography, the purity was found to be 9
It was 8.7%, and the content rate of dodecamethylpentasiloxane was 48 ppm. In addition, the analysis by gas chromatography did not detect a component having a longer retention time than dodecamethylpentasiloxane.
The content of dodecamethylpentasiloxane is n-
It was determined by the internal standard method using ratradecane. The conditions of the gas chromatography here are that the gas chromatography body has a product name of GC14B (manufactured by Shimadzu Corporation),
The column is a capillary column equivalent to OV-1, and the detector is F
Using ID, injection part temperature 210 ℃, detection part temperature 230
The column temperature was increased from 50 ° C to 200 ° C at a temperature increase of 10 ° C / min.

The glass lens 100 washed by this washing
When the individual pieces were evaluated by the breath test and the visual test after the optical thin film deposition, no spots or residues were found. In the same washing process, when the content of dodecamethylpentasiloxane in hexamethyldisiloxane was 75 ppm, slight spots were found in the breath test and the visual test, and a sufficiently clean washing result was obtained. I couldn't do it.

[0017]

EXAMPLE 2 Hexamethyldisiloxane distilled and purified in Example 1 is soaked in dust-free wiper paper (Bencot, trade name, manufactured by Asahi Kasei Corp.) to form a transparent plate made of PMMA (polymethylmethacrylate). It was rubbed once and washed by hand. The PMMA transparent plate was adhered after fingerprints by hand oil, but as a result of hand-wiping, fingerprint marks on the transparent plate were removed and a cleaned surface was obtained.

[0018]

Example 3 Hexamethyldisiloxane commercially available for general industry was purified by distillation using a distiller having about 30 theoretical plates, the purity was 99.0%, the content of dodecamethylpentasiloxane was 37 ppm, Hexamethyldisiloxane was obtained in which a higher boiling point component than dodecamethylpentasiloxane was not detected. 63.5 parts by weight of this purified hexamethyldisiloxane and ethanol of a first grade reagent (purity 9
9.5% or more) and 36.5 parts by weight were stirred and mixed to obtain a mixed composition containing hexamethyldisiloxane as a main component. This was impregnated with dust-free wiper paper in the same manner as in Example 2, and the compact camera body made of polycarbonate containing glass filler was hand-washed. As a result, a clean surface was obtained without stains on the surface.

Further, the composition of hexamethyldidyloxane and ethanol is in an azeotropic state at the above-mentioned mixing ratio and has a boiling point of 71.4 ° C., which is lower than that of the single composition, and is more dry. There was an improvement. Hexamethyldisiloxane 63.3-64.3% by weight, ethanol 35.
A boiling point of 71.4 ° C. was observed in the range of 7 to 36.7% by weight, and an azeotropic state was achieved in the range of this compounding ratio, and the boiling point was lowered and the composition ratio was stabilized. As a result, by using this mixture in the azeotropic state as the finishing hand-wiping cleaning liquid, better stability of drying property and cleaning property can be obtained.

Further, in the mixed system of hexamethyldisiloxane and ethanol, the boiling point is 72.4 to 7 in the range of 35% by weight or more and 99% by weight or less of hexamethyldisiloxane.
It becomes 2.2 ° C., which shows better drying property as a cleaning solution, and the composition change when hexamethyldisiloxane is distilled in the range of 55 to 70% by weight is within 5% by weight. Stability of cleaning performance is obtained with the ratio composition. Further, dodecamethylpentasiloxane was added to the mixed composition of hexamethyldisiloxane and ethanol used in this example so that the content thereof was 80 ppm, and the same washing was performed. A slight stain was observed on the surface.

[0021]

Example 4 59.1 parts by weight of hexamethyldisiloxane purified in Example 3 and reagent grade 1 methanol (purity 9
9.5% or more) and 40.9 parts by weight were stirred and mixed to obtain a mixed-type hand-cleaning cleaning composition containing hexamethyldisiloxane as a main component. This was impregnated with dust-free wiper paper in the same manner as in Example 2, and the aluminum camera lens barrel was washed by hand wiping. As a result, a clean surface was obtained without stains on the surface.

Further, the composition of hexamethyldisiloxane and methanol is in an azeotropic state at the above-mentioned blending ratio, and has a boiling point of 58.7 ° C., which is lower than that of a single composition, so that the drying property is further improved. Was seen. Hexamethyldisiloxane 58.9-59.3% by weight, methanol 40.
A boiling point of 58.7 ° C. was observed in the range of 7 to 41.1% by weight, and an azeotropic state was achieved in the range of this compounding ratio, and the boiling point was lowered and the composition ratio was stabilized. By using this mixture in the azeotropic state as the finishing hand-wiping cleaning liquid, better drying property and stable cleaning property can be obtained. In the mixed system of hexamethyldisiloxane and methanol,
Even in the range of 30 to 95% by weight of hexamethyldisiloxane, the boiling point is lower than that of the simple substance composition, and the drying property as a cleaning liquid is better. Therefore, by applying the composition in the mixing ratio range described above to the finish cleaning, good drying property can be obtained.

[0023]

Example 5 Hexamethyl was prepared by stirring and mixing 54.3 parts by weight of hexamethyldisiloxane purified in Example 3 and 45.7 parts by weight of reagent primary 2-propanol (purity 99.5% or more). A mixed-type hand-cleaning finishing cleaning composition containing disiloxane as a main component was obtained. This was soaked in a dust-free wiper paper in the same manner as in Example 2, and the glass optical lens was hand-washed. As a result, a clean surface was obtained without stains on the surface.

Further, this hexamethyldisiloxane and 2
The propanol composition was in the azeotropic state at the above-mentioned blending ratio and had a boiling point of 76.4 ° C., which was a lower boiling point than in the case of the single composition, and the drying property was further improved. Hexamethyldisiloxane 54.1 to 54.5% by weight, 2-propanol 45.5 to 45.9% by weight in the range of 76.4
A boiling point of ℃ was observed, and an azeotropic state was achieved in the range of this mixing ratio, and the boiling point was lowered and the composition ratio was stabilized. By using the mixture in this state as the finishing hand-wiping cleaning liquid, better drying property and stable cleaning property can be obtained. In the mixed system of hexamethyldisiloxane and 2-propanol, the boiling point becomes lower than that of the simple substance composition even in the range of 25 to 95% by weight of hexamethyldisiloxane, and the drying property as a cleaning liquid is better. Therefore, even if the composition in the above-mentioned blending ratio range is applied to finish cleaning, good drying property can be obtained.

[0025]

EFFECTS OF THE INVENTION The finish cleaning composition of the present invention is highly safe for the human body and can be used for cleaning various materials such as plastic, metal, glass and ceramics with almost no effect. It has excellent penetrability and dryness, and it is possible to obtain a highly accurate clean surface without stains and residues after drying.

The finish cleaning method of the present invention can perform cleaning without stains and residues.

[Brief description of drawings]

FIG. 1 is a flowchart of a cleaning process of Example 1.

Claims (3)

[Claims] 1. Hexamethyldisiloxane is one of the main components, and the content of dodecamethylpentasiloxane is 5
A finishing cleaning composition, which is substantially free of a compound having a boiling point of less than 0 ppm and higher than that of dodecamethylpentasiloxane. 2. Hexamethyldisiloxane as one of the main components, and the content of dodecamethylpentasiloxane is 5
A final cleaning method comprising immersing an object to be cleaned in a composition for final cleaning which does not substantially contain a compound having a boiling point of less than 0 ppm and higher than that of dodecamethylpentasiloxane, and pulling the object after cleaning. 3. Hexamethyldisiloxane as one of the main components, and the content of dodecamethylpentasiloxane is 5
A finishing cleaning composition substantially free of a compound having a boiling point of less than 0 ppm and a boiling point higher than that of dodecamethylpentasiloxane is soaked in a hand-wiping tool, A finishing cleaning method characterized by wiping up an object to be cleaned with a tool.