JP3104588B2 - Method for producing cellulosic fiber subjected to internal hydrophilic treatment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cellulosic fiber which has a higher water-absorbing property than conventional cotton and other cellulosic fibers and which maintains the softness of cotton or cellulosic fiber. It is used not only as a material for ordinary clothes and underwear, but also as a material for sports clothes and work clothes, especially for sweating, or for diapers and diaper covers that require high water absorption, bed sheets for bedridden elderly people, etc. it can.

[0002]

2. Description of the Related Art Cotton is a natural fiber made of cellulose, but unlike hemp fibers such as linseed (ramie) and flax (linen), which are also made of cellulose.
Rich in hygroscopicity. This is due to the unique fiber structure of cotton.

[0003] In particular, there is a hollow portion called a lumen inside the fiber, and it is known that water molecules are absorbed through the lumen and small pores in the tissue, and the fiber has high hydrophilicity.

[0004] For these reasons, there are relatively few studies on hydrophilization of cotton fibers, and studies on the production of superabsorbent fibers / resins, superabsorbent nonwoven fabrics, ionic dye dyeable fibers, and the like have been conducted. It's just

It is known that the chemical treatment for hydrophilization is carboxymethylation with monochloroacetic acid used in the present invention.

[0006] However, hydrophilization of the fiber surface by chemical treatment is a method that has a high degree of reactivity and sacrifices the natural softness of the cellulosic fiber.

No attempt has been made to convert the cellulosic fibers described below in the present invention into garment fibers which are more water-absorbing without impairing the natural feel and fiber properties typical of cotton fibers.

[0008]

In the prior art, a high degree of hydrophilization of cellulose fibers such as cotton by chemical treatment impairs the soft feeling of the cellulosic fibers and deteriorates the touch. Externally, while maintaining the original feel and soft touch of cellulosic fiber, only improving the water absorption and moisture absorption performance and adjusting the degree of hydrophilicity slightly, especially for sports clothing materials and highly absorbent sheets The purpose is to give practicality to

[0009] For example, the superabsorbent cotton contemplated in the present invention is a fiber which exhibits a higher water absorbability by about 10 to 90% than untreated cotton.

[0010] If the hydrophilization treatment is carried out further, the mechanical strength is greatly reduced, the feeling unique to cotton fibers is impaired, and it is considered that the fibers are not suitable as clothing fibers.

In fact, a sample exhibiting a water absorption higher than that of untreated cotton by 100% or more has a remarkable change in appearance and a remarkable change in the feeling of cotton fibers.

[0012]

Means for Solving the Problems In order to achieve the above object, the present inventors have made intensive studies and, as a result, have reached the present invention.

That is, according to the present invention, cotton or other cellulosic fibers are sufficiently immersed (30 minutes or more) in a 2,3-epoxy-1-propanol (glycidol) solution or a monochloroacetic acid solution, and then the outside of the fibers is removed. 2,3-epoxy-1-propanol (glycidol) or monochloroacetic acid adhering to the part is washed and removed by immersing it in a solvent of the same kind as the used solvent for a short time of 10 seconds to 1 minute, and the same kind as it is The sample is immersed in a solution of 0.1% to 50% sodium hydroxide dissolved in the above solvent, and the degree of substitution of hydrophilic groups increases from the outside to the center of the fiber from 30 ° C to 100 ° C. Is a fiber-treated product obtained by subjecting the inside of a cellulosic fiber obtained by an addition reaction of a hydrophilic group to a position-selective hydrophilization, and the outside is the natural feeling and feel of the cellulosic fiber. Characterized in that to improve the only water absorbability without impairing.

When glycidol is used as the hydrophilizing agent, the hydrophilic group is a nonionic glycidol group, and when monochloroacetic acid is used, the hydrophilic group is an ionic carboxymethyl group.

A specific embodiment will be described below. The method of measuring the water absorption referred to here was that the sample was immersed in distilled water for about 2 hours, placed in a centrifuge, dehydrated at 4000 rpm for 4 minutes, weighed, and calculated by the following equation.

[0016]

(Equation 1) W ₁ : Weight of sample after centrifugal dehydration W ₀ : Weight of sample as constant weight in an environment of 20 ° C. and 65% RH

[0017]

Example 1 5 g of cotton sliver (25 to 35 mm in length, average fineness 1.9 d) was immersed in a 0.5% aqueous sodium hydroxide solution to remove impurities by washing.
It is immersed in 200 g of an aqueous solution having a concentration of 8.6% to 54.5% for 24 hours.

Then, glycidol attached to the fiber surface was
It was immersed in 00 cc of water for 30 seconds to remove it by washing, and was directly placed in 300 cc of a 2% aqueous sodium hydroxide solution (at a temperature of 50 ° C.).
(± 2 ° C.) for 1 hour to wash and remove unreacted substances.

The same operation can be performed with an acetone solution instead of an aqueous solution.

The water absorption of the internal hydrophilized cotton obtained in each case was as follows.

[0021]

[Table 1]

[0022]

[Table 2]

[0023]

Example 2 5 g of cotton sliver (length: 25 to 35 mm, average fineness: 1.9 d) was immersed in a 0.5% aqueous sodium hydroxide solution to remove impurities by washing, and then 200 g of a 50% glycidol / acetone solution was removed. Immerse in it for 2 hours.

After that, glycidol attached to the fiber surface was
It is immersed in 00 cc of acetone for 30 seconds for washing and removal, and is reacted as it is in 300 cc of acetone containing 20 cc of a 2% aqueous sodium hydroxide solution (at a temperature of 50 ° C. ± 2 ° C.) for 1 hour.

By repeating the same operation once to three times, three types of internally hydrophilized samples having different hydrophilization rates can be obtained.

At this time, the water absorption of the whole hydrophilized sample obtained without washing and removing the glycidol attached to the fiber surface is as shown in the table below. The overall water absorption is large, but the reaction proceeds to the surface. The feeling was hard.

[0027]

[Table 3]

[0028]

Example 3 5 g of cotton sliver (length: 25 to 35 mm, average fineness: 1.9 d) is immersed for 2 hours in 300 cc of a 33% strength monochloroacetic acid / acetone solution.

Thereafter, the monochloroacetic acid attached to the fiber surface is immersed in 300 cc of acetone for 30 seconds to be washed and removed.
As it is in 2.0 liter of acetone solution (temperature 50 ° C ± 2
C)), and then added so that the concentration of sodium hydroxide becomes 0.1% to 0.8%, and reacted for 1 hour to carboxymethylate the cotton cellulose.

Thereafter, by washing and removing the unreacted substances, five types of internally hydrophilized samples having different hydrophilization ratios could be obtained.

At this time, the water absorption of the whole hydrophilized sample obtained without washing and removing the monochloroacetic acid attached to the fiber surface is as shown in the following table. There was a difference in performance, and the hand was hard.

[0032]

[Table 4]

[0033]

Example 4 5 g of a cotton sliver (length: 25 to 35 mm, average fineness: 1.9 d) is immersed in 500 cc of a 45% concentration aqueous monochloroacetic acid solution for 2 hours.

Thereafter, the monochloroacetic acid on the fiber surface was immersed in 1000 cc of water for 30 seconds for washing and removal, and the sample was immersed in a squeezer (pickup ratio 80%) so that the weight of the cotton sliver became 9 g. Reaction at 50 ° C. for 1 hour in 20 cc of 20% aqueous sodium hydroxide solution,
Carboxymethylation of cotton cellulose.

Thereafter, by washing and removing the unreacted substances, four types of internally hydrophilized samples having different hydrophilization ratios could be obtained.

At this time, the water absorption of the whole hydrophilized sample obtained without washing and removing the monochloroacetic acid attached to the fiber surface is as shown in the following table. There was a difference in performance, and the hand was hard.

[0037]

[Table 5]

[0038]

According to the present invention, it is possible to obtain a fiber having higher water absorption without impairing the natural feeling unique to cellulosic fiber.

Continuation of the front page (56) References JP-A-3-825 (JP, A) JP-A-60-2707 (JP, A) JP-A-2-229260 (JP, A) JP-A-1-148874 (JP) , A) (58) Fields investigated (Int. Cl. ⁷ , DB name) D06M 13/00-13/535

Claims (1)

(57) [Claims] After immersing cotton or other cellulosic fibers in a 2,3-epoxy-1-propanol (glycidol) solution or a monochloroacetic acid solution for 30 minutes or more, the fibers adhere to the outer portions of the fibers. , 3-epoxy-1-propanol (glycidol) or monochloroacetic acid is washed and removed by immersing in a solvent of the same kind as the used solvent for a short time of 10 seconds to 1 minute, and then 0.1% in the same kind of solvent as it is. The sample is immersed in a solution of sodium hydroxide having a concentration of about 50%, and the hydrophilic group is added at 30 to 100 ° C. so that the degree of substitution of the hydrophilic group increases from the outside to the center of the fiber. A method for producing a cellulosic fiber, comprising: