JPH10195080A - Azeotropic composition, draining steam desiccant using the same, draining steam drying method and draining steam drying device - Google Patents

Abstract

(57) [Summary] [Problem] An azeotropic composition that is free of spots such as semiconductors, liquid crystals, glass lenses and the like, has a high drying speed, can be used for steam drying, and has easy liquid management and is renewable. The present invention provides a draining steam desiccant, a draining steam drying method, and a draining drying device using the same. SOLUTION: (a) hexamethyldisiloxane;
(B) Latent heat of vaporization is 130 cal / g or less and water is 30 ° C.
An azeotropic composition characterized in that the azeotropic composition is substantially composed of a substance having an azeotropic composition of 5 to 70% by weight when dissolved in 6 to 50% by weight and mixed with hexamethyldisiloxane.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to drainage drying of precision parts such as semiconductors, liquid crystals and glass lenses, and more particularly to an azeotropic composition exhibiting a high drying rate, excellent dry finish and regenerating ability, etc. The present invention also relates to a draining steam drying agent, a draining steam drying method and a draining steam drying apparatus using the same.

[0002]

2. Description of the Related Art Freon has been frequently used for drying electronic components such as a mounting substrate such as a semiconductor and optical components such as a lens. However, since chlorofluorocarbon has problems such as destruction of the ozone layer, various studies have been made on a desiccant and a drying method for substituting chlorofluorocarbon, while it is expected to be completely eliminated.
In recent years, especially in fields that require precision drying, such as color filters for semiconductors and liquid crystals, after alkaline cleaning and pure water rinsing,
A method of drying with a vapor of a hydrophilic organic solvent such as alcohol has come into practice.

[0003] However, the above-described cleaning method of performing steam drying with a hydrophilic organic solvent after the alkali cleaning and pure water rinsing described above has a problem in that solvent attack, that is, whitening or cracking of plastic parts and resin coatings is liable to occur. In addition to the fact that the amount of condensate generated on the surface of the object to be cleaned is small due to the large heat of condensation, drainage tends to be insufficient. However, there is a problem that a residue (dry spot) is easily generated.

[0004] Among the steam drying methods, there is "draining drying" for the purpose of drying without stains after a plating step or after using an aqueous cleaning agent. Currently such applications include alcohols, especially isopropyl alcohol (IP
A) is being used, but there is a problem that drying spots are easily generated due to a large heat of evaporation, and the drying spots become more prominent due to moisture absorption from the air.

[0005] Further, alcohols such as IPA azeotrope with water, so that they cannot be separated and regenerated by distillation and must be disposable. In addition, since the vapor density is low, volatilization loss is large. Further, since the drying speed is slower, there is a problem that hot air drying may be required even after steam cleaning.

[0006] Furthermore, since steam drying with a hydrophilic solvent having infinite compatibility with water such as IPA displaces water adhering to parts, the water concentration in IPA gradually increases. This water forms an azeotrope with the IPA, which also increases the water concentration in the steam bath. This affects the replacement of water on the surface of the component, which causes a decrease in drying properties such as generation of watermarks and particles. For this reason, it is important to control the water concentration in the IPA, and it is necessary to perform management such as liquid exchange according to the lifetime of the liquid and the number of treatments, and non-resistance of the liquid. Further, as described above, IPA in which water adhering to parts has been replaced has to be used as a waste liquid in order to maintain IPA purity, and has a problem of high consumption and high running cost.

[0007] As a method for solving the above-mentioned problem, there has been proposed a method of draining and washing with a mixed system of perfluorohexane and trifluoroethanol. However, since this mixed system contains perfluorohexane which has no hydrophilic property, it is drained. It has a problem of poor sex. In the first place, perfluorohexane and trifluoroethanol are not compatible in the liquid state, making liquid management difficult.In addition, condensed liquid leaks unevenly on the surface of the object to be dried, causing drying spots. There is a problem that it is easy.

[0008]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and it is possible to carry out high-speed steam-drying without any spots such as semiconductors, liquid crystals, and precision parts such as glass lenses. It is a further object of the present invention to provide a draining steam desiccant, a draining steam drying method, and a draining steam drying device using an azeotropic composition that is easy to manage and renew.

[0009]

The present inventors have found that (a) hexamethyldisiloxane and (b) a latent heat of vaporization of 130 c
at al / g or less, water dissolves in 6 to 50% by weight at 30 ° C., and when mixed with hexamethyldisiloxane, 5 to 7
It has been found that an azeotropic composition substantially consisting of a substance having an azeotropic composition of 0% by weight is excellent in water displacement, drying speed, drying characteristics, reproducibility and the like. The substance (b) preferably has a latent heat of vaporization of 120 cal / g or less, 8 to 40% by weight of water dissolved at 30 ° C., and an azeotropic content with hexamethyldisiloxane of 10 to 50% by weight, More preferably, the latent heat of vaporization is 110 cal / g or less, the content of water is 10 to 30% by weight dissolved at 30 ° C., and the content of azeotropic distillation with hexamethyldisiloxane is 20 to 40% by weight.

In the present invention, it has been found that an azeotropic composition composed of hexamethyldisiloxane and tert-pentyl alcohol is particularly excellent in water displacement, drying speed, drying characteristics, regenerating ability and the like. Was sent. This azeotropic composition exhibits excellent drainability with a small amount of addition, although the mutual solubility in water is low.

That is, the azeotropic composition of the present invention comprises:
It is characterized by comprising hexamethyldisiloxane and tert-pentyl alcohol. Further, the draining steam desiccant according to the present invention is characterized by being substantially composed of an azeotropic composition comprising hexamethyldisiloxane and tert-pentyl alcohol.

The constituent ratio of each component in the azeotropic composition of the present invention is from 61 to 67 parts by weight of hexamethyldisiloxane,
It is preferable that the tert-pentyl alcohol is in the range of 33 to 39 parts by weight, and an azeotropic composition having an azeotropic temperature of 362 to 369 K at such a composition ratio is obtained. The specific composition ratio of the azeotropic composition can vary depending on conditions.

Here, the azeotropic composition in the present invention is:
It means that the composition behaves like an azeotrope, ie has an azeotropic point and exhibits constant boiling characteristics and does not tend to fractionate when boiling or evaporating. Thus, in such compositions, the composition of the vapor formed during boiling or distillation is the same or substantially the same as the original liquid composition. If the liquid composition changes during boiling or evaporation, it changes only minimally or negligibly. This is in sharp contrast to non-azeotropic compositions in which the liquid composition changes to a substantial degree during boiling or evaporation. Since the azeotropic composition does not cause fractional distillation when boiling, the flammability of the combustible solvent can be eliminated in some cases. Further, there is an advantage that the cleaning agent mixed with the dirt component can be regenerated using a steam cleaning device without causing a change in composition. Further, the azeotropic composition contains components in excess of the azeotropic composition within a range that does not substantially impair the characteristics of the azeotropic composition as described above, that is, additives are added to the azeotropic composition. An azeotropic composition having a boiling point shifted by about ± 5 ° C. and exhibiting substantially the same properties as the above-mentioned azeotropic composition is also included.

As described above, the azeotropic composition of the present invention has an azeotropic composition. The azeotropic property is exhibited when the boiling point of the mixture is lower or higher than the specific boiling point of each component. Therefore, in order to obtain an azeotropic mixture, in many cases, it is not possible to obtain the azeotropic mixture simply by mixing the components, and when the boiling point of the mixture is lower than the intrinsic boiling point of each component, the components are mixed at an arbitrary ratio. Distill the liquid,
The fraction can be obtained by repeatedly distilling the fraction or by rectification with a number of stages. The azeotropic composition (mixture) thus obtained is characterized in that no substantial change in the composition of the fraction is observed even when distillation is repeated under a constant pressure. The specific composition ratio of the azeotropic composition is
It can vary depending on conditions. An azeotropic composition can be obtained in the same manner.

In the azeotropic composition of the present invention, hexamethyldisiloxane has a surface tension of 15.9 dyn / cm (293
K), which is small and excellent in permeability. In addition, the Kauributanol value (KB value), which is an index of the dissolving power, is as small as about 15, and there is almost no possibility that the object to be cleaned such as plastic is deteriorated by steam drying. Furthermore, the latent heat of evaporation is about 50
It has good drying properties due to its small cal / g. However, because hexamethyldisiloxane is hydrophobic,
Good water displacement cannot be obtained by itself.

On the other hand, tert-pentyl alcohol is
The latent heat of vaporization is 106.2 cal / g, and methanol (26
3 cal / g), ethanol (202.7 cal / g), IPA
(161 cal / g). As shown in FIG. 2, carbon atoms such as tert-pentyl alcohol have 5 carbon atoms.
Alcohols have a lower latent heat of vaporization than alcohols having 3 to 4 carbon atoms. A polar solvent having a low latent heat of vaporization is excellent in drying characteristics because the surface of the component is cooled during drying so that moisture in the atmosphere does not dew. In addition, the drying characteristics depend on the water content. Solvents with a high water content, even with low latent heat of vaporization, form dry spots on the part surface. For example, propylene glycol monomethyl ether has a low latent heat of vaporization of 107.6 cal / g and is excellent in drying characteristics, but has infinite compatibility with water, and thus is liable to form a dried stain due to mixing of water or moisture absorption. Tert-pentyl alcohol has a low latent heat of vaporization, and water is 1 to tert-pentyl alcohol.
It dissolves moderately at 4.0% by weight (30 ° C.) and contains little excess water. Table 1 shows the latent heat of vaporization of isomers of tert-pentyl alcohol and mutual solubility with water. Incidentally, the mutual solubility refers to the solubility of another liquid in each liquid when the two liquids are saturated solutions and coexist in equilibrium.

[0017]

[Table 1] Of the alcohols having 5 carbon atoms, tert-pentyl alcohol has the highest mutual solubility with water and is excellent in water displacement. It has been found that when water is replaced using a polar solvent having an appropriate mutual solubility with water such as carbon number 5, water replacement by immersion is difficult, but water can be replaced by steam. However, when used alone, the drying speed is inferior to that of methanol, ethanol and IPA.

If the object to be cleaned is plastic, solvent attack may occur depending on the type and use conditions.

The draining steam desiccant in the present invention may be any one using the azeotropic composition of the present invention, and is not limited to the azeotropic composition of the present invention alone.
ert-pentyl alcohol azeotropic composition ratio and drainage,
As long as the drying property is not impaired, for example, another organic solvent, a surfactant and / or a stabilizer may be further mixed and used. Further, a three-component azeotropic composition may be formed with hexamethyldisiloxane, tert-pentyl alcohol, and a polar solvent.

For example, the cost can be reduced by mixing a hydrocarbon such as heptane as an organic solvent. Further, perfluorocarbons such as C ₆ F ₁₄ , C ₇ F ₁₆ and C ₈ F ₁₈ and CF ₃ CF ₂ CFHFHCF ₃
A combination of hydrofluorocarbon or C ₄ F ₉ OCH hydrofluoroether or C ₃ HCl ₂ F hydrochlorofluorocarbons such fluorocarbons such as _5, such as ₃ etc. can be used, whereby the flame-retardant or nonflammable Can be provided. The mixing ratio of these hydrocarbons is 10 to 100 parts by weight of the azeotropic composition.
To 10,000 parts by weight or less, more preferably 5000 parts by weight or less. The mixing ratio of fluorocarbons is preferably in the range of 10 to 10000 parts by weight, more preferably 5000 parts by weight or less, per 100 parts by weight of the azeotropic composition. In addition, the above-mentioned hydrocarbons alone,
Alternatively, two or more kinds can be added in combination.

Examples of the draining performance improver that can be added to the composition of the present invention to improve the draining performance include polar solvents such as surfactants and hydrophilic solvents. The surfactant contributes to the improvement of the drainage property particularly by immersion. Surfactants preferably used in the present invention include polyoxyalkylene alkyl ether sulfonates, anionic surfactants such as phosphate esters, polyhydric alcohol fatty acid esters, polyoxyalkylene fatty acid esters, and polyoxyalkylene alkyl ethers. Nonionic surfactants, amphoteric surfactants such as imidazoline derivatives, cationic surfactants such as alkylamine salts and alkyl quaternary ammonium salts,
Examples thereof include surfactants based on a combination of an amine compound and a saturated fatty acid, and terpene compounds extracted from natural products, higher fatty acid esters, and the like, which are rarely present as a single substance. Further, it is also possible to use a synthetic compound in which a part of the chemical structure of each compound described above is replaced with a fluorine atom or a silicon atom.
Although the composition ratio of the surfactant is not particularly limited, it is preferably 20 parts by weight or less, more preferably 3 parts by weight or less based on 100 parts by weight of the azeotropic composition. The above-mentioned surfactants can be added alone or in combination of two or more.

The polar solvent preferably used in the present invention includes, for example, 1-butanol, 2-butanol, isobutyl alcohol, tert-butanol,
-Pentanol, 2-pentanol, 3-pentanol, 2-methyl-1-butanol, isopentyl alcohol, methyl propionate, ethyl propionate, methyl ethyl ketone, 2-pentanone, 3-pentanone, 2
-Hexanone, acetic acid, ethyl acetate, propyl acetate, isopropyl acetate, isobutyl acetate, sec butyl acetate, methyl isobutyl ketone, formic acid, propyl formate, n-butyl formate, isobutyl formate, propylene glycol monomethyl ether, propylene glycol monoethyl ether, triethyl Fluoroethanol and the like.

The composition ratio of the polar solvent is not particularly limited, but is 0.1 to 10,000 parts by weight, preferably 1,000 parts by weight or less, more preferably 100 parts by weight, based on 100 parts by weight of the azeotropic composition. Not more than parts by weight. In addition,
The polar solvents described above can be added alone or in combination of two or more.

Examples of the stabilizer which can be added to the azeotropic composition of the present invention include epoxides such as glycidol and cyclohexene oxide, 1,4-dioxene,
Ethers such as 3,5-trioxene, 1-pentene,
Unsaturated hydrocarbons such as 1-hexene; acrylates such as methyl acrylate and ethyl acrylate; These stabilizers are preferably added at a ratio of about 0.1 to 5% by weight based on the total weight of the detergent. The above stabilizers can be added alone or in combination of two or more.

The azeotropic composition of the present invention and the steam desiccant using the azeotropic composition can be applied to various objects to be cleaned, and the material of the object to be cleaned is not particularly limited. Examples include metals, ceramics, and plastic materials. For example, metals and semi-metals include iron, aluminum, silicon, copper, stainless steel, etc., ceramics include silicon nitride, silicon carbide, aluminum oxide, glass, porcelain, etc., and plastics include polyamide, polyimide, epoxy, polyolefin, and polyester. , An acrylic resin and the like, and a composite material thereof may be used. Specific examples include electronic parts such as printed circuit boards and mounting parts, electric parts, semiconductor parts, metal parts, surface treatment parts, precision equipment parts, optical parts, glass parts, ceramic parts, plastic parts, and the like.

The draining steam desiccant containing an azeotropic composition as an active ingredient has been described above. Such an azeotropic composition is not limited to a draining steam desiccant such as a solvent for coatings, a reagent, and various solvents. The application may itself be used as an azeotropic composition.

In the present invention, the above-mentioned hexamethyldisiloxane and tert-pentyl alcohol are formed into an azeotropic composition, thereby extracting the characteristics of each of these components. That is, the azeotropic composition of the present invention,
Hexamethyldisiloxane has both excellent permeability and good drying speed, and high water displacement of tert-pentyl alcohol, and is suitable for a draining steam desiccant because it contains little water and does not deteriorate plastics. It can be said that it is a composition. A substance azeotroping with hexamethyldisiloxane has a latent heat of vaporization of 130 cal /
g and less than 5 to 70% by weight of water dissolved at 30 ° C. and mixed with hexamethyldisiloxane
Azeotropic composition, and preferably has an latent heat of vaporization of 120.
When cal / g or less, water dissolves at 8 to 40% by weight at 30 ° C. and has a content of 10 to azeotrope with hexamethyldisiloxane.
To 50% by weight, more preferably 110ca.
1 / g or less, water dissolves in 10 to 30% by weight at 30 ° C., and the content of azeotrope with hexamethyldisiloxane is 20%.
To 40% by weight. More specifically, 3-methyl-
Examples thereof include alcohols such as 2-butanol, ketones such as methyl ethyl ketone, and esters such as methyl propionate.

The azeotropic composition of the present invention exhibits water-replaceability by steam. The vapor of the azeotropic composition has a large distance between the molecules of the hydrophobic hexamethyldisiloxane and the hydrophilic tert-pentyl alcohol, and the hydrophilic group of the tert-pentyl alcohol makes it easy to take in water. The entrapped water falls along with the liquid condensed on the component surface, and is repelled and separated from the azeotropic composition of condensed hexamethyldisiloxane and tert-pentyl alcohol. Since the condensate is largely affected by hydrophobic hexamethyldisiloxane, the mutual solubility with water is almost negligible, and the condensate is separated into an azeotropic composition and water. The azeotropic composition has substantially no fluctuation in the liquid composition during use, and has a water displacement property, a drying rate,
A desiccant excellent in drying characteristics, re-performance and the like can be obtained. Furthermore, since it has finger removal properties, it is possible to remove light oil and particles by steam. In addition, the composition of the present invention can be replaced with water by immersion using both ultrasonic and mechanical stirring. Water replacement with steam is effective for lenses, silicon wafers, color filters, and other flat surfaces. If the surface shape of the component is complicated, draining by immersion is effective.

Further, a draining steam drying method and a draining steam drying apparatus using a draining steam drying agent comprising the azeotropic composition of the present invention will be described with reference to FIG. The draining steam drying apparatus of the present invention is an open-top type, in which a draining drying target 7 is stored, means for storing the draining steam desiccant 1, and a circulation pump (not shown) for heating the draining steam desiccant. A draining steam drying tank 3 having a heater 2 provided therein and a receiving tray 4 for receiving condensate after the draining steam drying agent is heated, pipes 6 and 6a arranged along the draining steam drying tank 3, a draining steam drying tank A specific gravity separating mechanism 5 connected to the cooling pipe 8 connected to the drying tank 3; By using this apparatus shown in FIG. 1, it is possible to dry articles by applying steam without immersion. Since there is no need for immersion, there is no possibility that a dirt component or the like adhering to the article is mixed into the draining steam desiccant, and the article can be dried with a higher purity draining steam desiccant. Further, there is no need to reduce the pressure during steam drying.

The articles which can be treated by the draining steam drying apparatus of the present invention include those having a flat surface such as a lens, a silicon wafer and a color filter. However, when drying an article having a complicated shape, the contact area increases, so that immersion as in the past may be more effective.

As described above, according to the draining steam desiccant and the apparatus using the azeotropic composition of the present invention, the composition change during use can be suppressed as much as possible, and the water replacement property, drying speed,
It has excellent drying characteristics and reproducibility, and does not contain a chlorine-based organic solvent typified by freon as a basic component, so that it does not cause destruction of the ozone layer. Further, as described in detail in the description of the azeotropic composition, while not deteriorating the plastic, by separating water, it is possible to suppress the incorporation of moisture, so that the occurrence of stains due to the contained moisture and Corrosion of metal such as rust can be suppressed as much as possible.

[0032]

BEST MODE FOR CARRYING OUT THE INVENTION

Example 1 First, hexamethyldisiloxane having a gas chromatography purity of 99.5% and tert-pentyl alcohol having a gas chromatography purity of 99.5% were mixed at a weight ratio of 1: 1, and 200 g of this mixture was placed in a distillation flask. Distillation was performed under normal pressure using a rectification column having 30 theoretical plates. By this distillation,
An azeotropic distillate was obtained between 362 and 369K. The composition consisting of this azeotropic fraction was used as a draining steam desiccant.

The above azeotropic distillate was analyzed by gas chromatography, and the actual addition ratio was assigned based on the obtained peak area ratio. As a result, 64% by weight of hexamethyldisiloxane and 36% by weight of tert-pentyl alcohol were obtained. there were. The gas chromatography was performed under the following conditions.

[Gas chromatography conditions]
Shimadzu GD-14A (TC-D), column: sus 2
mx 3mmφ (GL Science Chromosolve Co., Ltd. WA
YDMC8, mesh 60/80), filler: Silicone
SE-30 10%, Injection temperature: 523K, TC
-D temperature: 3K, initial temperature: 323K, initial holding time: 0
Min, continuous temperature rise: 10 K / min, final temperature: 523 K, final holding time: 0 min, current: 100, FR CR H
e: 40 ml, ATTENUATION: 64 In addition, the weight ratio of the composition in the present specification is obtained by analyzing the mixed composition by gas chromatography under the above conditions, and calculating the addition ratio based on the peak area of the obtained component. Is shown.

Table 2 shows the azeotropic composition of Example 1 above, its starting components, hexamethyldisiloxane and tert.
-Pentyl alcohol, the respective surface tension (298
K) and KB values.

[0036]

[Table 2] Examples 1 and 2 and Comparative Examples 1 to 8 The azeotropic composition of the present invention (Example 1), the azeotropic composition (Example 2) and 100% by weight of IPA as a comparative example (Comparative Example 1), hexamethyldiamine Using an azeotropic composition of siloxane and a polar solvent (Comparative Examples 1, 2, 3, 4, 5, 6, and 8), and 100% by weight of hexamethyldisiloxane (Comparative Example 7), a drying rate under the following conditions: , Water displacement rate / appearance (SEM observation), and composition change due to water contamination were evaluated.

[Evaluation of Drying Speed] As an object to be cleaned, MICRO SLIDEGLASS (thickness: 0.8 to 1.0 mm, pre-cleaned, 76 × 26 m) rinsed with pure water after alkali washing.
m) was prepared.

A vapor phase was formed using a tall beaker containing Example 1 and a heater. The object to be cleaned was immersed in the boiling vapor phase for one minute and pulled up, and then the drying speed of the condensate was measured. The drying rates of the compositions of Example 2 and Comparative Examples 1 to 8 were similarly evaluated. Table 3 shows the results.

[Water Replacement Rate and Appearance] COVER GLASS was rinsed with pure water after washing with alkali as the object to be washed.
(18 × 18 mm) was prepared. COVER GL wet with pure water
The ASS was immersed in the boiling vapor phase of Example 5 and the time required for water displacement was measured visually. After that, 1
The COVER GLASSB was dried while being pulled at a pulling speed of 5 mm / sec, and the appearance (SEM observation) was evaluated. Example 2,
The respective compositions of Comparative Examples 1 to 8 were similarly evaluated for the water displacement rate and appearance. Table 3 shows the results.
Shown in

[Composition Change Due to Water Mixing] 100 g of the co-composition of Example 1 of the present invention was weighed and placed in a 200 ml glass bottle, and 10 g of water was further added thereto and the lid was closed. The glass bottle was shaken with a shaker for 3 minutes and then centrifuged for 3 minutes. It was cleanly separated into the composition (upper layer) and water (lower layer). The composition ratio of the upper layer was determined by gas chromatography. In Example 2 and Comparative Examples 1 to 8, variations in composition due to water separation were similarly evaluated. Table 3 shows the results.

[0041]

[Table 3] As is clear from Table 3, Examples 1 and 2 are excellent in the drying speed, the water replacement speed, and the drying quality, and hardly change the composition due to the mixing of water, so that the composition change during use can be suppressed as much as possible.

Example 1 and Comparative Example 1 Next, for Example 1 and Comparative Example 1, the calculation of the water removal rate and the appearance inspection after drying were performed.

200 g of the azeotropic composition of Example 1 was placed in a tall beaker, and a vapor phase was formed using a heater. The glass lens after the polishing and washing was put into this vapor phase to perform water replacement. Thereafter, the lens was dried while pulling up the lens at a pulling rate of 15 mm / sec from the vapor phase.

The water removal rate of the water-dried and steam-dried lens is determined by the following method, and the dried state (surface condition and presence or absence of dried spots) is visually observed and observed with a scanning microscope to inspect the appearance after drying. Was done. Table 4 shows the evaluation results.

The water removal rate was determined by first removing the lens after draining and drying with steam of the azeotropic composition of Example 1 into dehydrated ethanol to dissolve the remaining water, and quantifying the water by the Karl Fischer method ( Ag), while the water content of the lens not subjected to the draining and steam drying according to Example 1 was similarly determined (Bg).
Then, it was determined from these in accordance with the following formula.

[0046]

(Equation 1) Further, as a comparative example with the present invention, the same drainage drying target (glass lens) as in Example 1 was subjected to drainage steam drying by IPA (Comparative Example 1). Thereafter, in the same manner as in Example 1, calculation of the water removal rate and appearance inspection after drying were performed. Table 4 also shows the results. Example 1 is 1
00% of the water was removed, and the appearance was good both visually and by SEM observation.

[0047]

[Table 4] Example 1, Comparative Examples 1, 9 Next, the water content of Example 1 and Comparative Examples 1, 9 was examined.

The hexamethyldisiloxane of the present invention and te
An azeotropic composition of rt-pentyl alcohol (Example 1) and each component of IPA 100% (Comparative Example 1) and tert-pentyl alcohol 100% (Comparative Example 9) were placed in a thermostatic chamber (2).
(0 ° C., 60% RH), weigh 100 g into a 200 ml glass bottle, and further add water to the total weight of each component.
It was added in a ratio range of 0.1 to 50% by weight. The glass bottle was shaken for 1 minute with a shaker, and allowed to stand for 10 minutes, and the water content of each component was measured by gas chromatography. The result is shown in FIG.

As is clear from FIG. 3, the composition of Example 1 has a water content of 2.0 even when the proportion of water added is increased.
% Or less, indicating that the water content is lower than that of IPA and tert-pentyl alcohol alone, and the influence of water is small.

Example 1 and Comparative Examples 1 and 2 Further, with respect to Example 1 and Comparative Examples 1 and 2, the water removal rate was calculated and the appearance after drying was measured using the draining steam dryer according to one embodiment of the present invention. An inspection was performed. An apparatus whose configuration is shown in FIG. 1 was prepared. The draining steam drying apparatus shown in FIG. 1 contains the draining steam drying agent 1 according to the first embodiment,
There is a draining steam drying step having a draining steam drying tank 3 in which the heater 2 heats and vaporizes the draining steam desiccant 1 of the first embodiment to generate steam 1a of the draining steam desiccant 1. In the drying apparatus shown in FIG. 1, water replacement and drying are performed by the steam of the draining steam desiccant 1 according to the first embodiment. The condensate 1b of the steam 1a used for water displacement and drying is transferred from the tray 4 to the specific gravity separation mechanism 5 by a pipe 4a.
Sent to The condensate 1c condensed in the cooling pipe 8 provided to prevent the vaporization of the vapor 1a is sent to the specific gravity separation mechanism 5 by the pipe 6a. The condensed liquids 1b and 1c sent to the specific gravity separation mechanism 5 are regenerated by removing moisture, sent to the draining steam drying tank 3 and used as steam 1a.

The glass filter (10 sheets / basket) after the chromium plating treatment, which is the object 7 to be drained and dried, is continuously washed 100 times with the draining steam drying apparatus shown in FIG. 1 100 times. Was. The 100th drained and dried product was subjected to the calculation of the water removal rate and the appearance inspection after drying by the method described above. Table 5 shows the evaluation results.

Further, as a comparative example of the present invention, the same chromium plating treatment as in Example 1 was performed by using the draining steam drying apparatus shown in FIG. 1 in the same manner as in Example 1 except that IPA was used as the draining steam drying agent. The subsequent glass filter was washed with water and drained with steam and dried continuously 100 times (Comparative Example 1). Similarly, except that an azeotropic composition of hexamethyldisiloxane and ethanol was used as a draining steam desiccant, water washing and draining steam drying of the glass filter after the chromium plating treatment were continuously performed 100 times ( Comparative Example 2). Similarly, with respect to the 100th dried and dried product, the water removal rate was calculated and the appearance of the dried product was examined in the same manner as in Example 1. The results are shown in Table 5.

[0053]

[Table 5] As is clear from Table 5, according to Example 1 in which the azeotropic composition of hexamethyldisiloxane and tert-pentyl alcohol of the present invention was used as a draining steam-dried composition,
Although the water removal rate and the drying quality were both excellent in the 100 times of draining steam drying, in Comparative Example 1 using IPA, a decrease in the drying quality in which dry spots occurred was observed. This is considered to be due to the fact that water could not be removed from the IPA, the water accumulated in the IPA, and the high latent heat of vaporization of the IPA. Further, in Comparative Example 2 using an azeotropic composition of hexamethyldisiloxane and ethanol, not only the drying quality was lowered, but also the water removal rate was lowered.

Examples 3, 4, 5 and Comparative Example 1 Examples 3, 4, 5 and IPA1 which are compositions of the present invention
Using 00% by weight (Comparative Example 1), the drainage property by immersion was evaluated under the following conditions.

Miniature bearing (made of stainless steel) 5
The pieces were immersed in water, immersed in a stainless steel container containing 500 ml of Example 1 for 1 minute, and subjected to ultrasonic waves to remove water. Thereafter, the miniature bearing was dried while being pulled up at a pulling speed of 5 mm / min. Draining and drying by this immersion were continuously performed 200 times. 10
Every time the sedimented water was removed from the drain. 20
The water removal rate of the dried and dried product of the 0th time is determined by the above-mentioned method, and the condition after drying (surface condition and presence or absence of dried spots) is visually observed and the appearance is inspected after drying with a scanning electromicroscope. Was done. The drying rates of Examples 3, 4, 5 and Comparative Example 1 were similarly measured. Table 6 shows the results.

[0056]

[Table 6] As is clear from Table 6, according to the composition containing an azeotropic component of hexamethyldisiloxane and tert-pentyl alcohol of the present invention (Examples 3, 4, and 5), the water removal rate was obtained even after 200 times of drying. In comparison with Comparative Example 1 in which IPA was used, the drying quality was reduced, and the water removal rate was also reduced. this is,
In Examples 3, 4, and 5, it is considered that good drainage and drying were maintained by periodically removing the sedimented water. On the other hand, IPA cannot separate water, which is considered to be due to accumulation of water in IPA.

[Brief description of the drawings]

FIG. 1 is a diagram schematically showing a configuration of a cleaning apparatus according to one embodiment of the present invention.

FIG. 2 is a graph showing the relationship between the carbon number of alcohols and latent heat of evaporation.

FIG. 3 is a graph showing the relationship between the amount of water added and the water content.

[Description of Signs] 1 ... Draining steam desiccant, 1a ... Steam, 1b, 1c ... Condensate, 2 ... Heater, 3 ... Draining steam drying tank, 4 ... Receiving unit, 5 ... Specific gravity separation mechanism, 6 ... Cooling pipe, 4a, 6a: Piping, 7: Draining steam drying target, 8: Canister

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Shigeo Yamafuji Toshiba Silicone Corporation 6-31 Roppongi, Minato-ku, Tokyo

Claims (13)

[Claims] (1) (a) hexamethyldisiloxane,
(B) Latent heat of vaporization is 130 cal / g or less and water is 30 ° C.
An azeotropic composition characterized in that the azeotropic composition is substantially composed of a substance having an azeotropic composition of from 6 to 50% by weight when dissolved with hexamethyldisiloxane and having an azeotropic composition of from 5 to 70% by weight. 2. The azeotropic composition according to claim 1, wherein the azeotropic composition consists essentially of hexamethyldisiloxane and tertiary pentyl alcohol. 3. An azeotropic composition according to claim 1, wherein an organic solvent, a surfactant and / or a stabilizer are added. (A) hexamethyldisiloxane,
(B) Latent heat of vaporization is 130 cal / g or less and water is 30 ° C.
A azeotropic composition substantially consisting of a substance having an azeotropic composition of 6 to 50% by weight dissolved in the above and a azeotropic composition of 5 to 70% by weight when mixed with hexamethyldisiloxane. . 5. The desiccant steam desiccant according to claim 4, comprising an azeotropic composition consisting essentially of hexamethyldisiloxane and tertiary pentyl alcohol. 6. The desiccating steam desiccant according to claim 5, wherein the azeotropic composition is the hexamethyldisiloxane 61.
~ 67 parts by weight and the tertiary pentyl alcohol 33 ~
A steam desiccant for draining, comprising 39 parts by weight. 7. The steam-drying agent according to claim 4, wherein an organic solvent, a surfactant and / or a stabilizer are added. 8. (a) hexamethyldisiloxane,
(B) Latent heat of vaporization is 130 cal / g or less and water is 30 ° C.
A azeotropic composition substantially consisting of a substance having an azeotropic composition of 6 to 50% by weight dissolved in the above and a azeotropic composition of 5 to 70% by weight when mixed with hexamethyldisiloxane. Draining steam drying cleaning method using 9. A draining steam drying tank having an open top for storing a draining steam desiccant, a draining steam drying object storage means disposed above the draining steam drying tank, an elevating means of the storage means, and the draining means. A receiving portion provided in the steam drying tank for receiving the condensate of the draining steam desiccant; a specific gravity separation mechanism for returning the condensate from the receiving portion to the regenerated draining steam desiccant to the draining steam drying tank; , A pipe that connects the draining steam drying tank, the receiving portion and the specific gravity separation mechanism, and a heater that includes a circulation pump that heats the draining steam desiccant housed in the draining steam drying tank. Draining steam dryer. 10. The steam-drying steam dryer according to claim 9, wherein the steam-drying steam drying agent comprises (a) hexamethyldisiloxane, (b) a latent heat of vaporization of 130 cal / g or less, and water at 30 ° C. From 50% by weight to 5% to 70% by weight
And a azeotropic composition consisting essentially of: 11. The draining steam dryer according to claim 10, wherein the azeotropic composition consists essentially of hexamethyldisiloxane and tertiary pentyl alcohol. 12. The draining steam drying apparatus according to claim 10, wherein the azeotropic composition is the hexamethyldisiloxane 61.
~ 67 parts by weight and the tertiary pentyl alcohol 33 ~
Draining steam drying apparatus, comprising 39 parts by weight. 13. The steam dryer according to claim 10, wherein an organic solvent, a surfactant, and / or a stabilizer are added to the steam dryer.