JPS62125077A - Method for discriminating dry degree of solvent washed cloth - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention is a solvent cleaning method that uses a specific solvent composition to quantitatively evaluate the degree of dehydration and dryness of clothes to be washed in a dry cleaner drying process based on changes in hue. This invention relates to a method for identifying the degree of dryness of cloth.

(Prior Art) The reality is that no method has been developed that can continuously identify the degree of dehydration and dryness during the drying process of cleaning cloth using perchlorethylene.

Originally, the drying process of dry cleaners using non-aqueous solvents such as perchlorethylene has had many practical issues such as shortening the drying time. This issue has not been explored in depth. One of the reasons for this is that there was no efficient method for continuously identifying the degree of dehydration and dryness of the washed cloth during the drying process after washing.

(Problem to be Solved by the Invention) As described above, there is no need for a special method to identify the state of dehydration and dryness during the drying process of cleaning cloth that has been conventionally washed using a solvent. Instead, the drying time is often set based on experience or determined based on the superficial dryness, which is not rational and efficient, and it is almost impossible to shorten the drying time. Furthermore, there were other problems such as difficulty in optimally drying the cloth depending on the type of cloth to be cleaned.

The present invention was made in view of these backgrounds, and as a result of research and study on solvent-added chemicals for which hue change can be used as a means of visualizable quantitative evaluation method, we have developed a solvent that is expected to be practical. The aim is to find a composition and use this to capture the hue change of a washed cloth during drying, and to rationally and efficiently understand the state of dehydration and drying.

(Means for solving the problem) Therefore, the present invention adds a predetermined amount of an indicator methyl red (color change range pH 4, 2 to 6.3) to the cleaning solvent Verchlorethylene, and then acetic acid is added so that the solution changes from yellow to yellow. A cloth to be washed is washed using a mixed solvent composition until it changes to orange color, and the degree of dehydration and dryness of the cloth to be washed is identified by a change in hue of the solvent composition during the drying process of the cloth to be washed. This configuration is intended to solve the above problems.

(Example) Examples of the present invention will be described in detail below with reference to tables and accompanying drawings.

As a method for visualizing the drying process of solvent-washed cloth, we investigated a specific agent that causes a hue change during the drying process. That is, while focusing on the possibility that the indicator methylreno-F can be used as a visualization agent for perchlorethylene, its pHfl? It has been found that acetic acid is suitable as an iJ stabilizer as an organic acid that is compatible with perchlorethylene and has almost the same evaporation properties as perchlorethylene.

The reason why acetic acid was found to be most suitable as a pH adjuster among many organic compounds is that, as shown in Table 1, acetic acid best satisfies the main properties required for the solvent composition of the present invention. There are several points that can be mentioned. That is, the evaporation property (
Boiling point, vapor pressure), solubility (SP value), toxicity, etc. should be emphasized from the viewpoint of safety and possibility of mixed use with perchlorethylene, but when viewed from these points, acetic acid is better than other similar It has the best balance and superiority in terms of performance compared to organic acids.

Table 1 Main physical property values of perchlorethylene and representative organic acids □ □ Rho': Art: Next, the identification method according to the present invention will be specifically explained in detail.

Trout, perchlorethylene 100m! ! A mixed solvent for visualization was prepared by dissolving 0.03 g of the indicator methyl red and adding acetic acid until the solution changed from yellow to orange.

On the other hand, prepare about 10 test cloths (white cotton cloth) of 10c+a, dry them in a dryer at 70° C. for about 10 minutes, and measure the ff1ffi of each.

The above mixed solvent (prepared solvent is 300 m+jl in advance! Approximately 150 mjl! is collected in an Erlenmeyer flask with a capacity of
The dry test cloth is immersed in the dry test cloth for several minutes while vibrating it, and after the liquid stops dripping, it is placed in a dryer (70° C.).

When the test cloth dries and the color begins to change, measure the weight of the test cloth (1). return.

When there is almost no change in the weight of the test cloth, the amount of residual solvent is considered to be zero (dry equilibrium state). The degree of dryness (residual solvent amount) at each stage is determined from the weight of the cloth repeatedly measured using the following formula (1). The results of residual solvent amount and hue change are fJ! It is possible to quantitatively understand the relationship between the two. Weight of the fabric (g) When using the drug-added solvent composition as a cleaning solvent,
In the drying stage after washing, discoloration (yellow to orange to red) occurs depending on the degree of dehydration and drying of the cloth to be washed, and this phenomenon is schematically shown in FIG.

That is, as the cloth progresses through the process of points A-B on the drying curve in FIG. 1, the hue gradually changes.

Then, when the dry state reaches point B, the hue suddenly begins to change from orange to red (orange-red).

(Effects of the Invention) As described in detail above, according to the present invention, it is possible to grasp the quantitative relationship between the degree of dryness of cloth and the change in hue, and it is possible to understand the quantitative relationship between the degree of dryness of cloth and the change in hue, and to do so in a rational and efficient manner regardless of the type of cloth to be washed. Deliquoring and
Inui S! It is possible to identify the degree of drying and to significantly shorten the drying time.

[Brief explanation of drawings]

Fig. 1 is a correlation diagram between residual solvent burnout change and hue change of a test cloth showing the results according to an example of the present invention, and Fig. 2 is a diagram showing the amount of residual solvent and its pl+ by a test cloth for understanding the present invention.
FIG. 3 is a schematic diagram for explaining the relationship between a change and a hue change.

Claims (1)

[Claims] A predetermined amount of the indicator methyl red (color change range pH 4.2 to 6.3) is added to the cleaning solvent perchlorethylene, and then acetic acid is added until the solution changes from yellow to orange. A method for identifying the degree of dryness of a solvent-washed cloth, which comprises washing the cloth and identifying the degree of dehydration and dryness of the cloth based on a change in the hue of the solvent composition during the drying process of the cloth.