JPS60215863A - Fiber bleaching method - 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 The present invention relates to nickel silver for textiles using chlorite, and more specifically, to a method for bleaching textiles with good texture.

A common method for bleaching cellulose, acrylic, and polyester fibers with chlorite is to activate an aqueous solution of chlorite with an inorganic acid such as sulfuric acid or phosphoric acid, or an organic acid such as formic acid or acetic acid. The method is to activate and bleach the chlorite by adding it as a curing agent and heating it to a high temperature of 90 to 95°C.

Bleaching at such high temperatures damages the fiber structure due to the rapid reaction conditions, significantly impairing the texture and resulting in fibers with poor sewability. Furthermore, it requires a large amount of steam, which incurs a great deal of expense, and the work environment is poor because it is operated under high temperature and humidity. Furthermore, the chlorine dioxide gas generated from Xu sandalwood causes an unpleasant odor.

In order not to impair the texture of the fibers, it is desirable to keep the bleaching reaction conditions mild, but a bleaching method that simply lowers the bleaching temperature □ significantly reduces the bleaching effect and causes uneven bleaching. In other words, improving the bleaching effect and maintaining texture are mutually exclusive, and one or the other had to be sacrificed. therefore,
There has been a strong desire for a method for bleaching fibers using chlorite, which does not impair the original texture of the fibers, does not reduce the degree of fabrication by 1 degree, and does not cause uneven bleaching.

The object of the present invention is to provide for textile bleaching with chlorite,
The purpose is to obtain a sufficient bleaching effect without causing uneven bleaching without impairing the original texture of the fiber, and another purpose is to overcome the drawbacks of odor pollution and deterioration of the working environment. The goal is to save energy in the bleaching process by reducing thermal energy consumption.

The present inventors conducted various research to achieve the above objective.
As a result of extensive research, a method for bleaching textiles using chlorite was established which could overcome the above-mentioned drawbacks.

That is, in textile bleaching with chlorite, an aqueous solution containing a chlorite aqueous solution and an activator is applied to the fiber at a rate of 5%.
A step of impregnating the fiber with 0 to 150 wt%, the fiber is impregnated with 30 to 70 wt%
This is a method for bleaching fibers with good texture, which consists of heating to 10°C to 70°C for 0.5 to 20 hours in a heat-retaining tank with a hot water tank at the bottom, and washing and drying.

Activators suitable for the present invention are aldehyde compounds such as formaldehyde, acetaldehyde, glyoxal, formaldehyde pisulfite salts, dialdehyde starch, and chlorinated isocyanuric acid compounds such as trichloroisocyanuric acid and dichloroisocyanurate. C,
It can be used alone or as a mixture. Since these activators have activation ability near neutrality, they do not damage the fibers, and there is no need to worry about controlling the bleaching solution. The amount of the activator added varies depending on the type of activator and is not particularly limited, but it is preferably added in an amount of 0.025 mol to 0.5 mol per 17 mol of chlorite.

In addition, the effective amount of chlorite added is 0.5 to 2.
It is within the range of 0wt%.

If it is less than 0.5 wt%, the bleaching effect will not be sufficient, while if it is more than 2.0 wt%, no difference in bleaching effect will be recognized and it will be uneconomical.

The method of the invention involves impregnating the fibers with an aqueous solution containing 17 chlorite and an activator simultaneously at h% or ji respectively. At that time, known surfactants may be added to further improve the bleaching effect. The amount of violet to be impregnated should be 50 to 150 wt per fiber, and if it is less than 50 wt, uniform impregnation will not be possible and uneven bleaching will occur. On the other hand, 150
Even if the amount is higher than WT, the impregnating solution will drip and cause uneven bleaching. The amount of impregnation can be adjusted, for example, by adjusting the amount of impregnation using a pressure roll after being dipped in a bath, or by spraying while moving the fibers and changing the speed of movement of the fibers and the amount of spray. Fire up all the amounts. The fibers with the impregnated amount adjusted in this way are heated uniformly to 30 to 70°C to the inside of the fibers.

If the heating is not uniform, uneven bleaching will occur. Furthermore, heating to temperatures as high as 70°C damages the fibers and impairs texture, while heating as low as 30°C does not activate chlorite. The wire fibers are then kept warm at 10 DEG to 70 DEG C. in an insulating bath with a hot water bath at the bottom for the time necessary to obtain the desired daily temperature, in practice from 0.5 to 20 hours. If kept at a temperature higher than 70°C, the fibers will be washed away and wind t9 will be lost, and if kept at a temperature lower than 10°C, no bleaching effect can be expected. The thermal insulation monk is equipped with a temperature-adjustable hot water tank at the bottom, and the temperature of the entire thermal insulation tank can be adjusted by adjusting the temperature of the hot water. Furthermore, since the fibers are kept warm under saturated water vapor pressure, the fibers are prevented from drying out during the heat keeping, and uniform bleaching is possible without uneven bleaching. Preferably 2
It breaks at 5-60'C. After bleaching, the fibers are washed and dried in a conventional manner69, and may be post-treated using a desalting agent.

According to the fiber bleaching method of the present invention, it is possible to bleach the fibers without impairing the original texture of the fibers and without producing bleaching particles 2.
You can get a juicy bleaching effect. Since the fiber is highly flexible, it has good sewability and is easy to sew. In addition, since bleaching is performed at low temperatures and there is little chlorite encapsulation, less chlorine dioxide gas is generated during the bleaching process, preventing odor pollution and at the same time overcoming the deterioration of the work environment such as high temperature and humidity. Historically, it requires less thermal energy consumption such as steam, making it possible to save energy in the bleaching process, and reducing the cost of bleaching chemicals by eliminating the need to use fabric softeners.

The present invention will be explained below with reference to Examples.

Example 1.2.3.4 Sodium chlorite 15 tit, nonionic sphere-210
(Nippon Oil & Fats Surfactant) 1 f/l, and a whitening solution containing the activating agent shown in Table 1 to a degree shown in the table was prepared.

10 kg of cotton stockinette was immersed in a bleaching solution and squeezed with a pair of pressure rolls made of Hypalon rubber to remove excess bleaching solution and give an impregnated amount of 10 kg. The sealed addition amount of sodium chlorite is 1.5 wt%. The cotton knitted fabric was brought into contact with a heating roll kept at 60°C and heated uniformly, and then
A 60℃ hot water tank is installed at the bottom, and the internal temperature of the heat retention tank is set at 60℃.
It was kept warm for 2 hours in a heat insulating tank kept at ℃. The cotton knitted fabric taken out from the heat insulating tank was washed with water and dried according to a conventional method. After bleaching, the cotton knitted fabric was measured once, and its sewability was also measured as a guide for evaluating its texture. 1
The sewability was measured using a Nippon Denden Z-1001DP whiteness meter, and the sewability was measured using a J&M sewability tester manufactured by Gottlich Co., Ltd. 8
Evaluation was made by measuring the negative force. The results are shown in Table 1.

Comparative Example 1 Sodium chlorite 2.5t/L, Noni Daikyo-200
(Surfactant made by NOF) 1 f/l, formic acid 2.24
tit, ptI3.2 bleaching solution 600- was expressed as p+. Soak 1 oor of cotton knitted fabric in bleach solution and heat at 90℃ for 2 hours.
Bleached for an hour. It was washed with water and dried according to the usual method. After bleaching, the cotton knitted fabric was measured for whitening and sewability by the method described in Example 1. As a result, 1 degree is 8
2.5, and the average penetration power was 123.1. The bleached fabrics according to the invention shown in Examples 1 to 4 have an average penetration power of 51
．． 0 to 55.6, whereas the conventional bleached cloth of Comparative Example 1 had a high value of 123.1. This is because the fibers are sore and hard that it becomes difficult for the needle to penetrate, indicating that the texture is poor.

Example 5.6.7.8. Comparative Example 43 Example 2 and 3 were followed except that the concentrations of sodium chlorite and activator were changed. The results are shown in Table 2.

Comparative Example 2 Sodium chlorite 159/l, Noni quaternary-210,
If/l, sodium dichloro-lysocyanurate 7,
A bleach solution consisting of LO9/l was prepared.

10 pieces of cotton knitted fabric were soaked in a bleaching solution and crushed with a pressure roll to remove excess bleaching solution. The cotton knitted fabric was uniformly heated with a heating roll, but a 60'C hot water tank was installed at the bottom of the knitted cotton knitted fabric.It was kept at an internal temperature of 60°C for 2 hours in a heat insulating tank.

The cotton knitted fabric taken out from the heat insulating tank was washed with water and dried according to a conventional method. The polished knitted knitted fabric has original unevenness that can be discerned with the naked eye, and when one degree is measured using the method described in Example 1, the measurement points are 81.3.83.9.
It happened on the first shift with 86.0 and so on.

Comparative Example 3 Sodium chlorite 159/l, Nonion Tei-2,10
, 19/l, dichloroisozoanur-related sodium 7.
A bleach solution consisting of 1 f/l was expressed as v4.

10 kg of cotton stockinette was immersed in a bleaching solution and squeezed with a pressure roll 2 to remove excess bleaching solution to obtain 10 kg of impregnated violet. The cotton knitted fabric was brought into contact with a heating roll kept at 60°C and heated uniformly, and then kept warm for 2 hours in a heat-retaining tank kept at an internal temperature t'' of 60°C.

The heat-retaining tank does not have a hot water tank at the bottom, but is kept warm by a heat exchanger installed inside. When the cotton knitted fabric was removed from the heating tank, the moisture in the exposed areas had evaporated and dried. The degree of 1 degree in this part was low and uneven whiteness occurred.

Examples 9 and 10 Cotton knitted 10KQ was moved in a band shape with a guide roller, and 2
Example 2 was repeated, except that the aqueous solution of sodium chlorite and the aqueous solution containing the activator were sprayed separately from fixed uniform fan-shaped nozzles to vary the amount of bleaching solution impregnated on the cotton knitted fabric. Ta. The results are shown in Table 7i43 (impregnation rate = weight of bleaching solution (K9)/10 (Kψx100(1)
).

Table 3 Examples 11, 12, 13.14 The procedures were as in Examples 1 and 3 except that the temperature of the heat-retaining monk and the heat-retaining time were changed. The results are shown in Table 4.

Claims (1)

[Claims] 1. In fiber whitening with chlorite, an aqueous solution containing a chlorite aqueous solution and an activator is applied to the fibers at a concentration of 50 to 50%.
A step of impregnating the fiber with 150 wt%, a step of heating the fiber to 30 to 70°C, a step of keeping the fiber at 10 to 70°C in a heat insulating tank equipped with a hot water tank at the bottom for 0.5 to 20 hours, and a step of washing and drying. A textile bleaching method consisting of: 2. The activator is formaldehyde, acetaldehyde, glyoxal, formaldehyde pisulfite salt, aldehyde compound of dialdehyde dengue, and chlorinated incyanuric acid compound of trichlorinocyanuric acid, dichloroisocyanurate, singly or in a mixture. A fiber bleaching method according to claim 1. 3. The fiber bleaching method according to claim 1, wherein the amount of chlorite added is 0.5 to 2.0 wt%.