JPH09217098A - Cleaning composition and cleaning method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a cleaning composition composed of n-heptane and an alcohol solvent containing ethyl alcohol as a main component, having low toxicity and high dryability and exhibiting excellent degreasing performance, etc., in the cleaning of an optical glass, etc. SOLUTION: This cleaning composition is composed of (A) 50-90wt.% of n-heptane and (B) 10-50wt.% of an alcohol solvent composed mainly of ethyl alcohol. The component B preferably contains >=85wt.% of ethyl alcohol and contains isopropyl alcohol and n-propyl alcohol as the other components. The composition takes a pseudo-azeotropic state in the above mixing range. A composition composed of 55.7±2wt.% of the component A and 44.3±2wt.% of the component B has azeotropic nature. The composition is impregnated in a fibrous material and the surface of a cleaning object is wiped with the material to remove the stain from the surface.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cleaning composition which exhibits excellent degreasing and drying properties when cleaning an optical glass, a plastic molded article or the like as an object to be cleaned, and a cleaning method using the cleaning composition. Regarding

[0002]

2. Description of the Related Art In industrial cleaning, as described on page 33 of the publication "Precision Cleaning Manual" (Tsujitaka, published in 1986), it is nonflammable, less toxic, chemically and thermally extremely Highly stable chlorofluorocarbons, especially 1,
1,2-Trichloro-1,2,2-trifluorocarbon (CFC-113) is widely used, and this compound is used in methods such as steam cleaning and hand cleaning. On the other hand, in the case of hand-wiping cleaning, there is a case where the stain removability is required in addition to the excellent drying property. For this, against the above, an azeotropic mixed solvent of CFC-113 and ethanol or JP-A-1-18094. As described in Japanese Patent Publication No.
A mixed solvent with an organic solvent such as -113, isopropyl alcohol and methyl ethyl ketone is applied. If higher stain removal and drying properties are required, acetone, lower alcohol, ethanol.
Hand-cleaning is performed with an organic solvent having a good drying property such as a mixed solvent of diethyl ether. In addition to such washing, conventionally, an alternative CFC as described in JP-A-2-289693 or an azeotropic mixed solvent of an alternative CFC and various organic solvents is also used.

[0003]

[Problems to be Solved by the Invention] However, CFC
Specified CFCs such as -113 will destroy the ozone layer and cause environmental pollution, so that the amount used will be reduced, and future use in cleaning will be unfavorable. Further, the CFC substitute and the mixed solvent of the CFC substitute and the organic solvent are not completely free from the influence on the ozone layer, and it is stipulated that the use thereof will be stopped in the future.

On the other hand, lower alcohols such as acetone, alcohol, methanol, isopropanol, and mixed solvents of ethanol / diethyl ether are legally regulated by the Industrial Safety Law and the organic solvent poisoning prevention regulations. , It has been suggested to be harmful to the human body. For this reason, in application to washing, especially hand-washing, since it is often used in direct contact with the human body, it is necessary to pay close attention to safety and hygiene management in the washing process. In addition, lower alcohols such as ethanol and isopropyl alcohol have a high latent heat of vaporization and a low boiling point, but the drying property is poor and it is difficult to quickly obtain a dry surface. Further, in the case of acetone, the latent heat of vaporization is very high and the acetone is dried quickly, but there is a problem that the object to be cleaned is excessively cooled and dew condensation occurs. In addition to the above, in the case of a wide variety of stains in a wide range, it is difficult to easily remove with the above-mentioned cleaning agent, and therefore, it is necessary to replace the cleaning agent or perform hand-wash cleaning many times.

The above-mentioned ethanol / diethyl ether mixed solvent is often used as a hand-wiping solution in the optical field. However, this mixed solvent has a very low flash point of about -45 ° C. and is easily ignited, which is dangerous for work. Have problems with sex. Furthermore, since this mixed solvent does not have an azeotropic composition, there is a change in the composition over time (that is, diethyl ether evaporates earlier than ethanol), which causes the detergency and dryness to change with time. Is unstable. In addition, since ethyl alcohol is subject to liquor tax in a pure state and is relatively expensive, there is an additional problem that cleaning costs increase.

The present invention has been made in consideration of the above problems, and the invention of claim 1 uses an alcohol solvent containing n-heptane and ethyl alcohol as main components, and It is an object of the present invention to provide a cleaning composition which has low toxicity, has no influence on the global environment, and can exhibit higher drying properties than the state of the raw material.

It is an object of the present invention to provide a cleaning composition which is industrially easily available and can be manufactured at low cost by using an alcohol solvent.

According to the third aspect of the invention, the drying property and the stain removing property are excellent, and it is possible to obtain a high cleaning quality.
It is an object of the present invention to provide a cleaning composition which is stable in composition and has no change in detergency and drying property over time, and which is capable of avoiding a danger in work by suppressing a flash point.

It is an object of the invention of claim 4 to provide a cleaning method capable of removing strong dirt by using the above cleaning composition.

[0010]

The cleaning composition of the present invention comprises:
It is characterized by comprising 50 to 90% by weight of n-heptane and 10 to 50% by weight of an alcohol solvent containing ethyl alcohol as a main component. The cleaning composition having this composition ratio is in an azeotropic state in which its boiling point is lower than the boiling point of each single composition. In this case, as the alcohol solvent, one containing 85% by weight or more of ethyl alcohol and the other components being isopropyl alcohol and normal propyl alcohol can be used.

Since the above-mentioned n-heptane and alcohol solvents do not contain a halogen element that causes ozone layer depletion, they do not destroy the ozone layer even if they are volatilized into the atmosphere during cleaning and drying. Highly safe for the global environment.

One of the constituents of this cleaning composition, n-heptane, is a saturated hydrocarbon having 7 carbon atoms, its permissible concentration is 500 ppm, and its toxicity is relatively weak. On the other hand, the alcohol solvent, which is the other component, contains 85% by weight or more of ethyl alcohol, and therefore the characteristics as an alcohol solvent are almost the same as those of ethyl alcohol. As well known, alcohols such as ethyl alcohol have relatively low toxicity and oral toxicity is 13.7 ml / kg in LD ₅₀ (rat).
And the allowable concentration is 1000 ppm. It is clear from this value that the alcohol solvent has low toxicity.

Further, the composition comprises a cleaning composition of n-heptane and ethyl alcohol, and the flash point in the azeotropic and azeotrope-like manner is about -4 ° C from the flash points of the respective constituents. The flammability is controlled. From the above, the cleaning composition of the present invention composed of these two components is highly safe for the human body.

Further, ethyl alcohol, isopropyl alcohol, and normal propyl alcohol have improved solubility in polar stains, and n-heptane improves solubility in nonpolar stains. The mixed cleaning composition can exert detergency on a wide range of stains.

In the present invention, as a result of investigations by the present inventors, it was found that n-heptane and an alcohol solvent exhibit higher vapor pressure at the same temperature when they are mixed than when they are single. It has been put out. This revealed that an azeotropic compound was formed by mixing the two constituent components in the composition ratio described below.

On the other hand, 50-90% by weight of n-heptane,
In the mixed range of 10 to 50% by weight of the alcohol solvent, the boiling point under normal atmospheric pressure (about 740 to 760 mmHg) is 70 to 76 ° C., which is lower than that of the single component. As a result, the cleaning composition having this mixing ratio is in an azeotrope-like state and has a drying property having a significant difference as compared with the case of a single component.

The mixed composition ratio in the azeotropic state is 55.7 ± 2% by weight of n-heptane and 44.3 ± 2% by weight of the alcohol solvent. In this azeotropic state, the boiling point is the lowest, and the drying property is also the best. Generally, the lower the boiling point, the higher the volatility (dryability) of the composition,
The drying property is superior to that of a simple substance of n-heptane or a simple substance of an alcohol solvent containing a lower alcohol.
Therefore, when this cleaning composition is used for cleaning purposes, a good dry state can be obtained. Further, in the composition ratio in the azeotropic state, the composition ratio in the vapor-liquid equilibrium is exactly the same, so that the composition does not change even if volatilization occurs over time. This makes it possible to maintain a constant composition ratio and always maintain stable cleaning performance and drying performance, and to secure stable cleaning quality.

It should be noted that, while a cleaning agent consisting of ethyl alcohol alone is subject to liquor tax, a cleaning agent obtained by adding isopropyl alcohol or normal propyl alcohol to ethyl alcohol is not subject to taxation. It is relatively inexpensive and can be easily obtained industrially.

In the cleaning method of the present invention, the above cleaning composition is impregnated into a fibrous material, and the surface of the object to be cleaned is rubbed with the fibrous material to scrape off dirt. It is also possible to deal with strong dirt. As the fibrous material, an appropriate material such as a wiper, a cotton cloth, or a non-woven cloth can be selected.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION

(Embodiment 1) n-heptane (Maruzen Petrochemical Co., Ltd.)
And a trade name "Solmix AP-7 (manufactured by Nippon Kasei Co., Ltd.)" as an alcohol solvent containing ethyl alcohol as a main component, the mixed composition ratio is changed to prepare 200 g of each mixed composition. did. In this case, Solmix AP-7 is an alcohol solvent having a composition ratio of 85.5% by weight of ethyl alcohol, 4.9% by weight of isopropyl alcohol, and 9.6% by weight of normal propyl alcohol. The composition ratio of the adjusted mixed composition is such that the weight ratio of n-heptane: Solmix AP-7 is 9: 1 to 5: 5.

Single distillation is carried out for each of the prepared mixed compositions, and the boiling point in the initial distillation in the mixed state,
The composition ratio of the initial distillation composition (hereinafter referred to as gas phase composition ratio) and the composition ratio of the mixed composition in the distillation container when the initial distillate was obtained (hereinafter referred to as liquid phase composition ratio) were determined. Here, the initial distillation composition is a distillation composition collected when the boiling point shows a constant value after the distillation composition starts to flow out. The results are shown in Table 1.

As shown in Table 1, Solmix AP-7
In the range of the liquid phase composition ratio of 7.01 to 50.31% by weight, the boiling point of Solmix AP-7 alone is about 80 ° C and n
-It was confirmed that the boiling point was lower than the boiling point of heptane of 98.4 ° C, and that it was in an azeotropic state. The boiling points in Table 1 are normal atmospheric pressure (740 to 760).
mmHg).

Further, the XY line characteristic diagram of the gas-liquid equilibrium at the mixed composition ratio (liquid phase, gas phase) is shown by the calibration curve which is obtained by GC (gas chronograph) of the adjusted mixed composition in advance. Was produced. The conditions of the used GC are "Shimadzu GC-14B" for the model and J & W DB- for the column.
1, diameter 0.53, length 30m, injection temperature is 210
° C., detector FID temperature 230 ° C., 5 min column temperature conditions at a constant temperature analysis 40 ° C., the split ratio 10: 1, sample volume is on the order of 1μ l, range 10 ^3.

FIG. 1 shows this XY line characteristic diagram. The liquid phase composition ratio of Solmix AP-7 is on the X axis (horizontal axis), and the gas phase composition ratio of Solmix AP-7 is on the Y axis (vertical axis). Axis). From this FIG. 1, the azeotropic composition ratio in the mixed system of n-heptane and Solmix AP-7 was calculated.

In the azeotropic state, the composition state of the liquid phase and that of the gas phase are the same, so the intersection of this XY line characteristic diagram and the function Y = X (the point where the composition of the liquid phase and that of the gas phase are equal) is determined. When obtained, the liquid phase composition ratio of Solmix AP-7 was 44.3% by weight. Further, 100 g of a mixed composition having the obtained composition ratio of Solmix AP-7 of 44.3% by weight and n-heptane of 55.7% by weight was prepared and subjected to simple distillation to collect the distilled composition over time. Then, the composition change was determined. As a result, the weight percentage of Solmix AP-7 at the early stage of distillation was 44.
Since it is 3% by weight, n-heptane and Solmix A
The azeotropic composition ratio of P-7 is 55.7% by weight of n-heptane,
Solmix AP-7 was 44.3% by weight. Incidentally, this composition ratio can be varied within a range in which the physical properties of the cleaning composition in the above simple distillation do not change.
As a result of examining this width, n-heptane, Solmix A
All of P-7 were ± 2% by weight.

The azeotropic composition obtained above was used to apply 0.5 g of ink onto a slide glass (trade name "ma").
(JIC INK ”, oiliness), the stain removability and the dry state did not change over time, and were in a stable state even after performing hand-washing several times.

Thus, the azeotropic composition ratio was 55.7% by weight of n-heptane and 44.3% by weight of Solmix AP-7, and this azeotropic composition maintained a constant composition ratio. , Can always maintain stable cleaning performance and drying performance,
It is possible to stably obtain good cleaning quality without dew condensation.

[0028]

[Table 1]

(Embodiment 2) The n-heptane of Embodiment 1 is 55.7% by weight, and Solmix AP-7 is 44.
It was mixed as 3% by weight and stirred for 1 hour to prepare an azeotropic cleaning agent. On the other hand, ink (trade name "majic"
INK ", oiliness), pitch (Kuju Electric Co., Ltd., trade name" K3 "), and pine resin were applied on a slide glass in an amount of 0.5 g to prepare a cleaning object. Then, the cleaning agent described above is wiped with a wiper paper (trade name “Pure Leaf M
210 "made by OZU CORPORATION), and the object to be cleaned was hand-washed.

Similarly, when n-heptane is 50, 70 or 90,
A mixture having a mixing ratio of 50% by weight, 50% by weight, 30% by weight, and 10% by weight of Solmix AP-7 was prepared, and the mixture was stirred for 1 hour to prepare an azeotropic cleaning agent. I went.

The results of this hand-washing are shown in Tables 2 and 3.
Shown in Table 2 shows the cleaning results of the azeotropic composition, and Table 3 shows the cleaning results of the azeotropic composition. Hand-washing was performed, and the evaluation of the washing result was performed visually. “◯” is a level where the stain is completely removed, “Δ” is a level where the stain is slightly left but is almost removed, and “x” is a level where the stain is not removed. From these tables, both the azeotropic and azeotrope-like compositions were able to remove most of the dirt.

[0032]

[Table 2]

[0033]

[Table 3]

Further, the above-mentioned azeotropic and azeotrope-like composition is impregnated in a wiper paper to obtain 100 mm × 15 mm ×
4mm polystyrene, polymethylmethacrylate, ABS (acrylonitrile-butadiene-)
Each test piece of styrene resin) and polycarbonate was rubbed 10 times continuously, and the attack property of each material was visually observed. The results are shown in Table 4. In the table, “◯” is the level without change.

[0035]

[Table 4]

As described above, when the azeotropic composition containing 55.7% by weight of n-heptane and 44.3% by weight of Solmix AP-7 was used for washing, it was more than when it was used in each component unit. The range of applicable stains is widened, and it is possible to apply various stains with the same detergent without changing the detergent. Further, the attacking property is not found in all materials, and since the attacking property is small, it is possible to perform cleaning regardless of the material.

(Embodiment 3) The n-heptane of Embodiment 1 is 55.7% by weight, and Solmix AP-7 is 44.
It was prepared at a mixing ratio of 3% by weight and sufficiently stirred to prepare an azeotropic mixed solvent, and a volatilization performance test was conducted on this mixed solvent, each component of n-heptane and Solmix AP-7.

The volatility test was carried out using an azeotropic mixture solvent, AP-
Put 2 ml of each of 7 and n-heptane in a petri dish,
It was carried out in an atmosphere of 25 ° C./60%, and a change in the residual volume ratio% of each solvent was confirmed in the elapsed time from 0 minute to 20 minutes. The results are shown in FIG.

From FIG. 2, 55.7% by weight of n-heptane,
When the azeotropic composition containing 44.3% by weight of Solmix AP-7 is volatilized, the volatility is improved as compared with the individual components of Solmix AP-7 containing n-heptane and a lower alcohol.

[0040]

The cleaning composition according to claim 1 has low toxicity to the human body and does not affect the global environment. Furthermore, by controlling the flash point, it is possible to avoid work hazards.

In addition to this effect, the cleaning composition of claim 2 is industrially easily available and can be manufactured at low cost.

The cleaning composition of the third aspect is excellent in good drying property (volatility) and stain removability, and is improved in cleaning property as compared with cleaning with a single component, and high cleaning quality can be obtained.

A cleaning method according to a fourth aspect is such that the above cleaning composition is impregnated into a fibrous material such as a wiper, cotton cloth, non-woven cloth,
By rubbing and washing, strong dirt can be removed.

[Brief description of drawings]

FIG. 1 is an XY line characteristic diagram of vapor-liquid equilibrium of Solmix AP-7.

FIG. 2 is a characteristic diagram of a volatility test.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical display location C11D 7:26 7:50)

Claims (4)

[Claims] 1. 50 to 90% by weight of n-heptane and 10 to 50 alcohol solvent containing ethyl alcohol as a main component.
%, And a cleaning composition. 2. The cleaning composition according to claim 1, wherein the alcohol solvent contains 85% by weight or more of ethyl alcohol, and the other components are isopropyl alcohol and normal propyl alcohol. 3. A cleaning composition comprising 55.7 ± 2% by weight of n-heptane and 44.3 ± 2% by weight of the alcohol solvent according to claim 2. 4. A cleaning method comprising impregnating a fibrous material with the cleaning composition according to claim 1 and wiping the surface of the object to be cleaned with the fibrous material.