JPH10317276A - Alkali thinning treatment of polyester fiber fabric - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for an alkali thinning treatment of a polyester fiber fabric capable of efficiently hydrolyzing the polyester fiber in high reproducibility even with an alkali of a lower concentration of 0.1-10%. SOLUTION: In a hydrolysis treatment of a polyester fiber fabric with an alkali, the polyester fiber is hydrolyzed using an alkali treating liquid composed of >=60 wt.% of an alkylene glycol or a polyoxyalkylene glycol as the solvent and water as another main solvent. Thus, a polyester fiber fabric is treated for alkali thinning.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for reducing the alkali content of a polyester fiber fabric.

[0002]

2. Description of the Related Art Polyester fibers are fibers that have various excellent physical properties and are mainly used in the field of clothing and the like. Sex was a major drawback in terms of hand.
This rigidity is due to the structure of the fiber having a high degree of crystallinity. In order to solve this problem, the fiber is treated in an aqueous solution of caustic soda or potassium hydroxide at a temperature of 60 ° C. or more and hydrolyzed. A so-called alkali weight reduction process for improving the texture of fibers has been developed in the United Kingdom in 1949 (UK Patent No. 652948).

[0003] In this alkali weight reduction processing, a weight reduction rate of several percent to 50% is required in order to obtain a feeling suitable for the purpose. A high-concentration aqueous solution of caustic soda is required, and the conditions differ depending on the continuous type or batch type. In any case, usually, a high concentration of 20 to 50% by weight of caustic soda is used in consideration of productivity. It is a target. As described above, when a high-concentration aqueous solution of caustic soda is used, not only does the danger of workers increase during alkali weight reduction processing, but also because of the high concentration, it is difficult to control the weight loss rate, and weight loss spots occur.
There were many problems such as inability to stably process.

In order to solve these problems, Japanese Patent Publication No. Sho 3
As disclosed in JP-A-7-3946, a method in which an amine is used in combination with an aqueous solution of caustic soda of 4% or less to promote alkali weight reduction, and a method in which a quaternary ammonium salt is used in combination as disclosed in US Pat. That is, 0.005 to 0.5% for 0.5 to 5% of alkali metal hydroxide.
%, A method of treating with an aqueous alkali solution to which a quaternary ammonium salt such as lauryldimethylbenzylammonium chloride is added. However, it has been found that in the former method, the effect of promoting hydrolysis is weak at a concentration of caustic soda of 1% or less, and the productivity is remarkably reduced particularly when a high weight loss rate of 20% or more is expected. Further, the latter method has a problem that it is extremely difficult to control the decomposition reaction rate to a constant level in actual work, because the effect of caustic soda of the quaternary ammonium salt used to promote fiber decomposition is too strong. ing.

As a method of accurately controlling the rate of weight reduction of polyester fibers, as disclosed in JP-B-61-160475, when polyester fibers are hydrolyzed in an aqueous alkali solution, alkali hydrolysis is substantially carried out. Before proceeding, determine the amount of treatment bath in the equipment and its concentration, and when the expected weight loss is reached based on the determined amount of treatment bath and caustic soda concentration, the weight of the woven or knitted fabric in the equipment, and the expected weight loss rate A method has been proposed to calculate the estimated caustic soda concentration of the treatment bath, perform statistical processing by comparing it with the actual weight loss rate, and predict the next measured caustic soda concentration to improve accuracy and reproducibility. ing. Such an alkali weight reduction method has recently been adopted in batch type weight loss machines, but if the accuracy of the titrator for caustic soda concentration is not very high, the weight loss rate cannot be controlled sufficiently, so that there is variation between lots. Therefore, there is a problem that the occurrence of the problem occurs, and it is necessary to further improve the accuracy in practical use.

[0006] On the other hand, since the productivity is inferior in the batch type weight loss method, a continuous type weight loss method has also been proposed and put into practical use. For example, according to Japanese Patent Application Laid-Open No. 57-61766, in order to enhance uniform adhesion of an alkaline aqueous solution in a dry heat atmosphere at a temperature of 50 ° C. or more and less than 100 ° C., a phosphate-based or alkyl-sulfite-based resin is used. 0.1 to 3.0% of alkaline penetrant
A method has been proposed in which the combined aqueous alkali solution is applied to the woven or knitted fabric by a so-called padding method or the like, which is squeezed with a mangle or the like, to complete the alkali hydrolysis reaction in a short time. However, in the case of the continuous type, since the weight reduction process is performed in consideration of the productivity, a high-concentration aqueous solution of caustic soda is generally required. There was a problem that management was difficult.

As described above, the decomposition of polyester fibers by alkali hydrolysis of caustic soda, etc., has its weight-reduction mechanism well established theoretically, and can be carried out by any of the batch method and the continuous method. It is a well-known method of improving the feel of polyester fiber fabrics that has been put into practical use, and any of these methods requires a high-concentration aqueous solution of caustic soda or a low-concentration quaternary ammonium salt. There are many problems such as that the alkali hydrolysis reaction is so intense that it is difficult to accurately control the rate of weight loss, and in recent years there has been no proposal for a drastic alkali weight reduction method for polyester-based fiber cloth which solves these problems.

[0008]

DISCLOSURE OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances, and is effective in reproducing polyester fibers efficiently and reproducibly even with an alkali having a low concentration of 0.1 to 10%. An object of the present invention is to provide a method for treating an alkali weight loss of a polyester fiber fabric that can be decomposed.

[0009]

The present invention attains the above object and has the following constitution. That is, the present invention relates to an alkali-treated polyester fiber cloth which contains at least 60% by weight of alkylene glycol and / or polyoxyalkylene glycol as a solvent and water as a main solvent during the hydrolysis treatment of the polyester fiber cloth with an alkali. And subjecting the polyester fibers to hydrolysis treatment using a liquid. Here, the phrase "and / or" means either one or both.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. Examples of the polyester fiber fabric used in the present invention include woven fabrics, knitted fabrics, and nonwoven fabrics mainly composed of polyester fibers such as polyethylene terephthalate and polybutylene terephthalate, and the above polyester fibers and modified polyester fibers, polyamide fibers, polyurethane fibers, and cotton. And knitted and woven knitted fabrics composed of mixed yarns, entangled yarns, and composite mixed yarns with natural fibers such as wool and wool. In the method of the present invention, the above-mentioned fiber cloth is subjected to hydrolysis treatment with an alkali. As the alkali used here, caustic soda, caustic potash, sodium carbonate, potash carbonate, or the like can be appropriately selected and used. In general, the use of caustic soda is advantageous from the viewpoint of the existing processing plant equipment. Usually, the concentration of the alkali hydrolyzing agent is suitably from 0.1 to 10% by weight, but can be appropriately determined according to the target weight loss rate.

According to the present invention, in the hydrolysis treatment with alkali, alkylene glycol and / or polyoxyalkylene glycol are used as a solvent in an amount of 60% by weight.
An alkaline treatment liquid containing water as described above and using water as another main solvent is used. Representative examples of the alkylene glycol used here include ethylene glycol and propylene glycol. Examples of the polyoxyalkylene glycol include polyethylene glycol and polypropylene glycol, and polyethylene glycol having a molecular weight of about 100 to 1,000 is preferably used from the viewpoint of simplicity in use. More preferably, polyethylene glycol in a liquid state at room temperature with a molecular weight of about 400 is used. The content of the alkylene glycol and / or the polyoxyalkylene glycol in the solvent is preferably at least 60% by weight, particularly preferably at least 80% by weight. When the content of the alkylene glycol and / or the polyoxyalkylene glycol is less than 60% by weight, the effect of promoting the alkali weight reduction is poor, and a remarkable effect cannot be expected as compared with the ordinary water-based alkali weight reduction.

Water is used as another main solvent of the above-mentioned solvents, and is used in an amount of less than 40% by weight. In the method of the present invention, the processing temperature and the processing time can be appropriately adjusted by a weight reduction rate suitable for a target feeling. Especially regarding the processing temperature, when processing at normal pressure,
Conditions vary depending on the content ratio of alkylene glycol and / or polyoxyalkylene glycol. When the content ratio of these glycols is 60 to 90% by weight, the treatment temperature is 60 to 100 ° C, preferably 80 to 100 ° C.
0 ° C. At a content ratio in this range, it is difficult to raise the temperature to 100 ° C. or more in a short period of time due to the influence of moisture in the solvent. On the other hand, the case where the processing can be performed by pressurization is not limited to this, but there is a problem that the processing apparatus becomes large-scale. The above-mentioned alkylene glycol and / or
Or when the content ratio of the polyoxyalkylene glycol is 9
When the content is 0% by weight or more, the processing temperature is about 60 to 180 ° C, and particularly preferably 80 to 140 ° C. If the temperature is lower than 80 ° C., the effect of effectively promoting the alkali weight loss is poor, and if the temperature is 140 ° C. or higher, if the treatment time is prolonged, the fibers may be melted and the strength may be extremely lowered, so care must be taken.

The processing conditions particularly recommended in the present invention are as follows: a mixed solvent of 95% by weight or more and less than 5% by weight of polyethylene glycol having a molecular weight of about 100 to 400, a bath ratio of about 1:20 to 30 and a processing temperature of 80%. As a guide, a temperature of about 140 ° C. and a processing time of about 5 to 30 minutes are guidelines. As a processing device,
Both a continuous type and a batch type can be adopted. In the case of the continuous type, an ordinary known continuous type weight loss machine can be used, and similarly to the water-based alkali weight reduction, the aging step after padding the processing liquid with a padder, that is, the adjustment of the residence time in the retention tank. is important. On the other hand, in the case of the batch type, an ordinary known liquid jet dyeing machine or a batch type weight loss machine can be used. However, the polyoxyalkylene glycol is particularly polyethylene glycol, and the content in the solvent is 95%. If it is more than 10% by weight, 10
Since processing at 0 ° C. or higher is possible, an open type processing machine can be adopted.

[0014]

The alkali hydrolysis of the polyester fiber of the present invention in an alkylene glycol and / or polyoxyalkylene glycol solution has not been clearly elucidated, but its concentration is lower than that of the conventional method. Alkali solution has a high reaction promoting effect and can consume alkaline agent in a short time, so that a weight loss rate close to the theoretical weight loss rate can be obtained efficiently, and swelling due to the high affinity of these glycols with polyester fibers. It is presumed that the alkali agent efficiently decomposes fiber molecules due to effects and the like. In addition, because of the low concentration, there is little danger in actual work, easy control of alkali hydrolysis reaction, high reproducibility, and obtaining a polyester fiber with a new feeling different from the conventional method. Can be.

[0015]

EXAMPLES Next, the present invention will be described in more detail with reference to examples. The measurement and evaluation of the weight loss rate of polyester fibers in the examples were performed by the following methods. (1) Weight loss rate The weight (S) of the sample before weight loss, which was conditioned for 2 hours at a temperature of 25 ° C. and a relative humidity of 60%, was weighed, and then subjected to alkali weight loss processing, and then under the same conditions as before weight loss. We perform humidity control in
The weight (W) after weight loss was measured and calculated by the following equation. Weight loss rate (%) = (S−W) / S × 100

Example 1 A plain fabric made of 100% polyester with ultrafine yarn was scoured and preset by a known method to obtain a fabric before weight reduction. Next, this woven fabric was cut into about 7 g, and a 12-color pot dyeing tester (manufactured by Texam Giken, MINI-COLOUR)
Using 12S), alkali reduction treatment was performed in 200 g of a treatment liquid having the following formulation 1 under three conditions of treatment temperatures of 80 ° C., 100 ° C., and 130 ° C. for 5, 10, 15, 20, and 25 minutes, respectively. Formulation 1 Polyethylene glycol 95.0% by weight (molecular weight 400) Water 4.9% by weight Caustic soda 0.1% by weight Then, after washing with hot water at 80 ° C. for 5 minutes, ordinary tumble drying (60 ° C., 20 minutes) to obtain a fabric with a reduced alkali content according to the method of the present invention.

For comparison with the present invention, a conventional water-based weight-loss formula 2 was used in place of the formula 1 used in this example.
The alkali weight reduction treatment was performed under exactly the same conditions as in this example. Formulation 2 Water 99.9% by weight Caustic soda 0.1% by weight The weight loss of the processed fabric of the present invention and the comparative sample was measured, and the results are shown in Table 1.

[0018]

[Table 1]

As is evident from Table 1, according to the alkali weight loss method of the present invention, the weight loss rate is remarkably faster than that of the ordinary aqueous weight loss method, and the alkali hydrolysis reaction is completed in a short time. Further, it can be seen that the reproducibility is high. The weight-reduced woven fabric according to the method of the present invention was a moist woven fabric having a good drape property.

Example 2 Using the same fabric as in Example 1 but cut into 7 g before the weight reduction treatment, 130 g
An alkali reduction treatment was performed at 10 ° C. for 10 minutes. Formulation 3 Polyethylene glycol 100% by weight (molecular weight 400) Water 5.0% by weight Caustic soda 0.5, 1, 2, 3, 5, 10% by weight 6 levels

For comparison with the present invention, a conventional water-based weight-loss formula 4 was used in place of the formula 3 used in the present example.
The alkali weight reduction treatment was performed under exactly the same conditions as in this example. Formulation 4 Water 100% by weight Caustic soda 0.5, 1, 2, 3, 5, 10% by weight 6 levels The weight loss rate of the present invention and the processed fabric for comparison was measured, and the results are shown in Table 2 together. . For reference, the theoretical weight loss rate was calculated by the following equation, and is shown in Table 2. Theoretical weight loss (%) = 192/80 × (weight of caustic soda) / (weight of dough) × 100

[0022]

[Table 2]

As is clear from Table 2, in the alkali weight reduction method of the present invention, the weight loss reaction is remarkably accelerated with a low-concentration alkaline solution as compared with the ordinary aqueous weight loss method, and a weight loss rate almost close to the theoretical weight loss rate is obtained. This shows that efficient alkali weight reduction treatment is possible.

[0024]

As described in the present invention, the alkali hydrolysis of polyester fibers in an alkylene glycol or polyoxyalkylene glycol solution has a high reaction promoting effect even in a low-concentration alkaline solution, so that a weight-reducing process with high reproducibility can be performed efficiently. It is possible. As a result, in actual work, the problem of uneven weight loss and the variation in the weight loss rate between lots are reduced, and stable processing can be performed. Further, in the case of the polyethylene glycol solvent of 95% or more shown in each of the examples, even at a low temperature treatment at a treatment temperature of less than 100 ° C., the alkali hydrolysis reaction is remarkably promoted, so that an energy saving effect can be expected. In addition, even under the condition of 100 ° C or more,
In the method of the present invention, processing can be performed under normal pressure, so that processing can be performed with a simple apparatus. In the method of the present invention, the decomposition reaction is accelerated in a shorter time, and the alkali hydrolysis can be carried out with good reproducibility by calculating the concentration of the alkali agent from the theoretical weight loss rate. It is possible.

Claims (1)

[Claims] 1. An alkaline treatment liquid comprising 60% by weight or more of an alkylene glycol and / or a polyoxyalkylene glycol as a solvent and water as a main solvent when the polyester fiber cloth is hydrolyzed with an alkali. A method for reducing the alkali content of a polyester fiber cloth, comprising subjecting the polyester fiber to a hydrolysis treatment.