JPH0219227B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a novel method for scouring fabrics containing cotton using low-temperature oxygen plasma. More specifically, by treating greige fabrics containing cotton with low-temperature oxygen plasma to make water-repellent components such as pectin and wax, which are impurities in cotton, hydrophilic, bleaching, mercerization, and dyeing can be carried out in subsequent steps. The present invention relates to a method for scouring fabrics containing cotton, which eliminates impediments to processing caused by impurities in cotton, which are problematic in such cases. "Scouring" as used in the present invention goes beyond the conventional scouring concept of decomposing and removing water-repellent components such as pectin, wax, and fat from cotton impurities with an alkaline substance, and goes beyond the concept of bleaching and mercerization in the post-process. It is used in the broad sense of eliminating processing impediments caused by impurities in cotton, which are problems in dyeing and the like. In the present invention, the cotton-containing fabric includes 100% cotton fabric or cotton and other fibers, such as polyester fiber, vinylon fiber, nylon fiber, polyacrylonitrile fiber, acetate fiber, and rayon fiber.
It refers to a fabric mixed with fibers such as wool, hemp, and silk, and the term fabric refers to sheet-like structures such as woven fabrics, knitted fabrics, and nonwoven fabrics. In addition, the term "mixed" as used in the present invention means that cotton fibers and other fibers coexist as constituent fibers of the fabric, and the coexistence type may be in any form such as blended spinning, twisted twisting, mixed weaving, mixed knitting, etc. It's okay. The main component of produced cotton is cellulose, but it contains 4 to 5% of water-repellent impurities such as pectin, wax, and fat. These impurities had a negative effect on subsequent processing steps such as bleaching, mercerization, and dyeing, so they had to be removed. Traditionally, scouring using alkali has been commonly used as a method to remove these impurities.
There are two types of processing methods: batch type and continuous type.
The former is a pressure pot scouring method, and the latter is a continuous scouring method using J-BOX, purple range, etc., but the essential treatment conditions common to these methods are impregnating the fabric with an aqueous solution of caustic soda or soda ash and a surfactant. The fabric was allowed to stay at a temperature of around 100°C or higher for 10 minutes or more. Therefore, the conventional water-based scouring method requires water costs, energy costs for heating, and costs for scouring aids such as caustic soda or soda ash, and surfactants, and moreover, the treated effluent after scouring is alkali,
Since it contains additives such as surfactants, there is a problem of water pollution, and there are various factors that increase costs, such as high wastewater treatment costs. In addition, recently, scouring using organic solvents such as perchloromethane has been developed, but this is not common because the use of organic solvents involves problems such as the cost of the organic solvent itself and air pollution caused by the organic solvent. In view of the current situation, the present invention was made based on a novel idea that is completely different from conventional scouring methods. The purpose of this invention is to perform scouring with a scouring effect that is almost the same as that of the conventional method in a short period of time without using excessive amounts of scouring or the like. In order to achieve this object, the present invention has the following configuration. That is, the present invention is a method for scouring a fabric containing cotton, characterized in that impurities on the fiber surface are made hydrophilic by subjecting the greige fabric containing cotton to a low-temperature oxygen plasma treatment. When performing scouring with the method of the present invention, conventional scouring agents, scouring aids, scouring water, etc. are not required, and the scouring effect can be achieved in a short time, so it is extremely rational and economical. . The present invention will be explained in detail below. In the present invention, scouring is performed by subjecting a gray cloth containing cotton to low-temperature oxygen plasma treatment. The gas used for plasma treatment is 100% oxygen or a mixture of oxygen and other gases other than oxygen. Other gases that can be used include nitrogen, water vapor, helium, argon, carbon dioxide, and carbon monoxide. Of course, air can also be used. The higher the mixing ratio of oxygen, the higher the scouring effect and the faster the processing speed, but in normal industrial production it is desirable that the oxygen content be 5% or more. The degree of vacuum in the processing machine during plasma processing may be such that low-temperature plasma (or unbalanced plasma) is generated by high-frequency irradiation, and the temperature of the processing atmosphere is such that it does not damage the fabric to be processed. In general, a range of 0.1 to 10 Torr, preferably 0.5 to 2 Torr is appropriate. Reduce pressure treatment conditions to 0.1~
The reason for limiting the pressure to 10 Torr is that if the degree of vacuum exceeds 10 Torr, the generation of low-temperature plasma becomes unstable, and the temperature of the processing atmosphere increases, which may damage or wet the fabric to be processed.
This is because maintaining the degree of reduced pressure at a high degree of 0.1 Torr or less not only increases costs but also reduces the oxygen concentration, which may reduce the plasma processing effect. The frequency of the radio frequency irradiated to generate low-temperature plasma can be used in a fairly wide range from the longest wavelength to the shortest wavelength, but preferably 1KHz ~
Those in the 300MHz range are easy to use. In practice, due to regulations such as the Radio Law, 13.56MHz, 27.12MHz,
It is best to use 40.68MHz, 915MHz, or 2450MHz. 100% oxygen with reduced pressure of 0.1 to 10 Torr
Alternatively, when a mixed gas containing oxygen is irradiated with high frequency waves and high frequency energy is applied to oxygen molecules, the oxygen molecules are excited and generate low-temperature plasma, which becomes highly reactive. Process the gray fabric. The processing time depends on the weight (fabric weight) of the fabric, its density, the content of volatile components such as moisture,
Although it varies slightly depending on the amount of adhering agent/sizing agent used in cloth making, high frequency irradiation conditions, oxygen concentration, pressure, or required scouring effect, generally it is sufficient to carry out the process for about 1 to 600 seconds, and more preferably 5 to 90 seconds. It is best to process within seconds. In the method of the present invention, if volatile components such as moisture are removed to some extent by heating the fabric or using other methods before the low-temperature plasma treatment, disturbances in the degree of vacuum accompanying the introduction of the fabric will be reduced and stable operation will be possible. The higher the removal efficiency of volatile components, the better the effect. In the present invention, a particularly good scouring effect can be obtained by adjusting the moisture content of the gray cloth containing cotton to 3% or less, and then subjecting the gray cloth to a low-temperature oxygen plasma treatment. The above-mentioned low-temperature plasma treatment with oxygen oxidizes and decomposes the water-repellent impurities contained in cotton-containing fabrics, making them significantly more wettable (hydrophilic) than untreated fabrics. The permeability of water into the fabric containing it is greatly improved. When performing bleaching, mercerization, dyeing, etc. on fabrics containing cotton in such conditions, the movement of aqueous solutions of dyes and processing chemicals is not hindered by impurities in the hydrophilized cotton, so they can be used freely. cellulose fibers of cotton can be reached. In conventional scouring methods for fabrics containing cotton, scouring was performed by decomposing and removing water-repellent components such as pectin, wax, and fat, which are impurities in cotton, using an alkaline substance, but the scouring method of the present invention However, it is not necessarily necessary to remove such impurities from cotton. The present inventors investigated the impurities in cotton that inhibit post-processing, and focused on the fact that the impurity was not the impurities themselves, but the water repellency of the impurities. We have discovered the fact that as long as the components are made hydrophilic, they will not interfere with the subsequent process even if they are not removed, and we have developed the scouring method of the present invention by using low-temperature plasma of oxygen as a method for making them hydrophilic. It had come to completion. As described above, in the scouring method of the present invention, it is not necessary to intentionally remove impurities from cotton, but if the fabric is left for a long time after being treated with low-temperature oxygen plasma, some of the impurities from cotton may be removed again. It tends to become hydrophobic. Therefore, in the scouring method of the present invention, it is preferable from the viewpoint of scouring stability to subject the fabric to a wet treatment to dissolve and remove impurities from the solubilized fabric after the low-temperature oxygen plasma treatment. In this case, wet treatment includes water washing, hot water washing, scouring, bleaching, mercerization,
This can be done by any of the staining treatments. Normally, solubilized impurities are dissolved and removed by washing with water or hot water, but there is no problem at all if the wet treatment is performed by conventional alkali scouring, and in this case, a very small amount of alkali Impurities in solubilized cotton can be dissolved and removed simply by using a substance and in a short time. In addition, the above-mentioned wet treatment may be performed by post-process bleaching, mercerizing, dyeing, etc., instead of washing with water, hot water, or scouring.In this case, impurities in the solubilized cotton may be This is advantageous because it is possible to simultaneously perform the dissolution removal and bleaching, mercerization, dyeing, etc. of the fabric. In any case, the fabric that has been subjected to low-temperature plasma treatment using oxygen according to the method of the present invention usually proceeds to the next process, that is, a wet process such as bleaching or mercerization, so the process from the plasma treatment to the subsequent wet process is continuous. It is desirable to remove impurities that have been oxidized and decomposed on the fabric and become water-soluble as soon as possible. Next, the method of the present invention will be explained with reference to examples. In the examples, the scouring effect of the fabric was measured using JIS
- The water absorption was measured by the dropping method of L-1096 and the Byreck method, and the whiteness of the fabric was measured.
This was done using method C of JIS-L-1013. Example 1 A plain woven fabric (kinkin) made of 100% cotton was prepared and subjected to low-temperature oxygen plasma treatment under the conditions of Recipe 1 below. This step is the scouring step of the present invention. Prescription 1 Gas used Air Decompression degree 1 Torr High frequency frequency 13.56 MHz High frequency output 10 KW/100 cm width Processing time 1 minute The water absorption performance of the treated fabric was measured here. The results are shown in Table 1. In addition, in order to compare the above-mentioned scouring method of the present invention with a conventional scouring method, gray fabric of the same standard as the above-mentioned fabric was scoured by the conventional general continuous scouring method using a purple oven as shown below, and its water absorption The effects are shown in Table 1. [Conventional scouring method] Immediately after padding in an aqueous solution containing 3 g of caustic soda and 1 g of non-ionic surfactant using a purple microwave, steaming treatment was performed using steam at 100°C for 20 minutes, followed by washing with water. dry.

[Table] As is clear from Table 1, the scouring method of the present invention was found to have a water absorption effect comparable to that of conventional scouring methods. Subsequently, when the scouring fabric according to the method of the present invention and the scouring fabric according to the conventional method were dyed under the same dyeing conditions, both were dyed in almost the same manner, and no dyed spots were observed. This shows that the scouring method of the present invention has a sufficient scouring effect similar to the conventional scouring method. The method of the present invention does not require a scouring agent and can achieve the same scouring effect as the conventional scouring method in an extremely short period of time. Example 2 Spun yarn with a blend of 65% polyester and 35% cotton
A gray poplin fabric using 40S/1 was prepared, and after its moisture content was adjusted to 1% using a hot flu dryer, it was subjected to low-temperature oxygen plasma treatment under the conditions of Recipe 2 below. This step is the main part of the scouring step of the present invention. Prescription 2 Gas used: 100% oxygen Decompression level: 0.7 Torr High frequency frequency: 13.56 MHz High frequency output: 5 KW/100 cm width Processing time: 25 seconds After this, a continuous bleaching method using a conventional purple oven is used to perform a bleaching finish. At 100℃ after immersion in an aqueous solution of the following formulation 3.
Steaming was performed for 20 minutes, followed by neutralization, washing with water, and drying. Prescription 3 Hydrogen peroxide (35%) 10 c.c. / Caustic soda 1.5 g / Sodium silicate 1 g / Nonionic activator 1 g / In order to examine the scouring effect of the fabric obtained, the water absorption and whiteness of the fabric were measured. I went to The result is the second
Shown in the table. In addition, in order to compare the above-mentioned scouring method of the present invention with a conventional scouring method, a conventional scouring method was used for comparison in Example 1 without performing the plasma treatment of the above-mentioned recipe 2 on gray fabric of the same standard as the above-mentioned fabric. The same treatment as in Example 2 was carried out in other respects to obtain a comparative example. The scouring effects are also shown in Table 2.

[Table] As is clear from Table 2, the scouring method of the present invention was found to have a scouring effect comparable to that of conventional scouring methods. The method of the present invention does not require a scouring agent and can achieve the same scouring effect as the conventional scouring method in an extremely short period of time. Example 3 A circular knit jersey gray fabric using a blended yarn of 2/48S with a blend ratio of 50% cotton and 50% wool was prepared, and after adjusting its moisture content to 2% using a hot flu dryer, the following formulation 4 was prepared. Oxygen low-temperature plasma treatment was performed under the following conditions. This step is the main part of the scouring step of the present invention. Prescription 4 Gas used Air Decompression degree 0.5Torr High frequency frequency 13.56MHz High frequency output 5KW/100cm width Treatment time 1 minute Next, the water absorption performance of the knitted fabric after plasma treatment was measured (the measurement results are shown in Table 3). ) Also,
Next, the knitted fabric was dyed red using a dip dyeing method using a direct dye on the cotton side and an acid dye on the wool side.
It was possible to dye uniformly without any dye spots. In addition, almost no decrease in the strength of the knitted fabric was observed. For comparison with the scouring method of the present invention, a gray fabric of the same standard as the above-mentioned knitted fabric was prepared, and the knitted fabric was scoured using the conventional scouring method in Example 1 in order to first refine the cotton side. However, the wool fibers were severely damaged, and the knitted fabric showed significant shrinkage and decreased strength, and no material with commercial value could be obtained. Therefore, there was no point in conducting water absorption and dyeing tests as comparative examples.

[Table] As described above, when refining a fabric containing both cotton and wool fibers, it was impossible to scouring the wool fibers without damaging them using the conventional scouring method, but the method of the present invention According to the method, complete scouring can be carried out in a short time without damaging the wool fibers and without the need for scouring aids.

Claims (1)

[Scope of Claims] 1. A method for scouring a fabric containing cotton, characterized in that impurities on the fiber surface are rendered hydrophilic by subjecting the greige fabric containing cotton to a low-temperature oxygen plasma treatment. 2. The low-temperature plasma according to claim 1, wherein the low-temperature plasma is a low-temperature plasma generated by irradiating high frequency to oxygen or a mixed gas of oxygen and other gases at a reduced pressure of 0.1 to 10 Torr. A method of scouring fabrics including cotton. 3. A cotton fabric characterized by adjusting the moisture content of the greige fabric containing cotton to 3% or less, and then subjecting the greige fabric to a low-temperature oxygen plasma treatment to make impurities on the fiber surface hydrophilic. Fabric scouring method including. 4. The low-temperature plasma according to claim 3, characterized in that the low-temperature plasma is a low-temperature plasma generated by irradiating high frequency to oxygen or a mixed gas of oxygen and other gases at a reduced pressure of 0.1 to 10 Torr. A method of scouring fabrics including cotton. 5. Making the impurities on the fiber surface hydrophilic by subjecting the greige fabric containing cotton to a low-temperature oxygen plasma treatment, and then subjecting the fabric to a wet treatment to dissolve and remove the impurities in the solubilized fabric. Features: A method for scouring fabrics containing cotton. 6. The low-temperature plasma according to claim 5, characterized in that the low-temperature plasma is generated by irradiating high frequency to oxygen or a mixed gas of oxygen and other gases at a reduced pressure of 0.1 to 10 Torr. A method of scouring fabrics including cotton. 7. Claim 5 or A method for scouring a fabric containing cotton as described in item 6. 8 Adjust the moisture content of the greige fabric containing cotton to 3% or less, then perform low-temperature oxygen plasma treatment on the greige fabric to make the impurities on the fiber surface hydrophilic, and then subject the fabric to a wet treatment. 1. A method for scouring a fabric containing cotton, which comprises dissolving and removing impurities from the fabric solubilized. 9. The low-temperature plasma according to claim 8, characterized in that the low-temperature plasma is a low-temperature plasma generated by irradiating high frequency to oxygen or a mixed gas of oxygen and other gases at a reduced pressure of 0.1 to 10 Torr. A method of scouring fabrics including cotton. 10. Claim 8 or A method for scouring a fabric containing cotton as described in item 9.