JP2000017572A - Method for affording cellulose-based fiber or cellulose- based textile product with yellowing-suppressive function involved in wearing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To afford a cellulose-based fiber or cellulose-based textile product with excellent anti-yellowing function suitable for underwear by hydrophilicization treatment of the above fiber or textile product. SOLUTION: A cellulose-based fiber or cellulose-based textile product is afforded with yellowing-suppressive function involved in wearing by hydrophilicizing the above fiber or textile product, that is, by introducing into the fiber or textile product one or more kinds of hydrophilic group selected from COOH, NH2 and SO3 groups to afford the fiber or textile product with a moisture absorption of 71-20 wt.%, for example, by carboxymethylating at 0.1-10 mol.% the fiber or textile product to introduce COOH group thereinto, or by polymerizing a monomer such as methacrylic acid or methacrylamide in such a state that the monomer is in contact with the fiber or textile product to effect grafting the hydrophilic molecules at a graft rate of 1-30% thereto.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for imparting a function of suppressing yellowing of cellulosic fibers or cellulosic fiber products (especially cellulosic fibers or cellulosic fiber products or cellulosic fiber underwear).

The present invention relates to a cellulosic fiber or a cellulosic fiber product (especially a cellulosic fiber or cellulosic fiber product or cellulosic fiber underwear for underwear), and more particularly to a cellulosic fiber or cellulose having a function of suppressing yellowing during wearing. The present invention relates to a cellulosic fiber product (especially cellulosic fiber to be worn underwear or a cellulosic fiber product or cellulosic fiber underwear).

[0003]

2. Description of the Related Art In general, a white system (particularly, whiteness of 100 or more,
Further, cellulosic products (e.g., 120 or more), for example, cotton clothing, especially underwear (underwear, T-shirts, etc.) gradually become yellow when repeatedly worn and washed. The cause of this yellowing is considered to be mainly due to oxidation and coloring of dirt components such as sweat attached thereto, and during repeated wearing and washing,
It is considered that the increase in yellowing is a major cause because the stain component that adheres and is colored in a state that cannot be completely removed even by washing is gradually accumulated.

[0004] Therefore, in addition to the essential function of underwear, which is to absorb (temporarily absorb) sweat (dirt), the underwear does not turn yellow even when worn and washed repeatedly (wear yellowing). That is, it is required to have a prevention function), that is, to have high durability whiteness (white resistance) as a great added value.

Conventionally, as a method of preventing yellowing of underwear, various methods for preventing the adhesion of dirt to cellulosic fibers have been studied from the viewpoint of "to make dirt less likely to adhere". For example, SR (soil release) in which cellulose-based fibers are treated with a fluorine-based or silicon-based treatment agent
There is processing.

However, when SR processing is performed on cellulosic fibers, they become water-repellent, and thus have a demerit on the function of removing sweat (dirt) from the skin, which is one of the important roles of underwear. In addition, there is a disadvantage that durability is not good in SR processing.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to provide a novel method for imparting a yellowing preventing function to cellulosic fibers or cellulosic fiber products. An object of the present invention is to provide a cellulosic fiber or a cellulosic fiber product having an excellent yellowing prevention function.

[0008]

SUMMARY OF THE INVENTION The present inventor considers that the concept of "reducing dirt" has a disadvantage in removing sweat dirt from the skin, which is one of the important roles of underwear. By changing the idea of "easy to remove even when soiled", focusing on oily substances as the main cause of sweat stains, making the fibers hydrophilic makes it easier to release sweat stains In other words, it was concluded that washing should be easy to remove, and it was found that cellulosic fibers were originally hydrophilic, but it was effective to further impart hydrophilicity to them. Was completed.

The present invention resides in a method for imparting a yellowing preventing function to wear, which comprises subjecting a cellulosic fiber or a cellulosic fiber product to a hydrophilic treatment.

The present invention has a hydrophilic group and a moisture absorption of 7.1 to 2
0% of cellulosic fibers or cellulosic fiber products.

The present invention resides in a cellulosic fiber or cellulosic fiber product having a carboxymethyl group and having a moisture absorption of 7.1 to 20%.

The present invention resides in a cellulosic fiber or cellulosic fiber product having a carboxymethyl group and having a carboxymethyl group introduction rate of 0.1 to 10 mol%.

[0013] The present invention provides any one of the above-mentioned cellulosic fibers or cellulosic fibers obtained by heat-treating a cellulosic fiber or a cellulosic fiber product in contact with a treatment solution containing monochloroacetic acid or an alkali metal salt of monochloroacetic acid. In textile products.

[0014] The present invention resides in any of the above-mentioned cellulosic fibers or cellulosic fiber products having a whiteness of 100 or more (particularly 120 or more).

The cellulosic fibers or cellulosic fiber products (hereinafter also referred to as "cellulosic fibers, etc.") include monofilaments and products using monofilaments. Products made from yarn, such as cotton yarn, cotton blended yarn, etc., for example, cotton cloth, cotton sliver (bundle)
And products made from cotton cloth and the like, for example, underwear and the like.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION A method for imparting a yellowing inhibiting function to wear A cellulose fiber or a cellulosic fiber product (especially a cellulose fiber for underwear or a cellulosic fiber product for underwear or a cellulose fiber underwear) is hydrophilized. Thereby, a wearing yellowing suppressing function can be provided. In a preferred embodiment, the cellulosic fiber or the like is subjected to a hydrophilic treatment to make the moisture absorption rate 7.1% or more, preferably 7.5% or more,
20% or less, preferably 15% or less.

The cellulose fiber or the like is subjected to a hydrophilization treatment, and the moisture absorption is, for example, 110% or more, preferably 120% or more (usually 120% or more) of the moisture absorption of the cellulose fiber or the like used as a raw material.
250% or less, more preferably 200% or less, particularly 150% or less), it is possible to impart a wearing yellowing suppressing function.

The moisture absorption is a so-called official moisture percentage, which is an increase rate of the official weight with respect to the absolute dry weight, and is calculated by the following formula.

[0019] Moisture absorption (%) = ([official weight] / [absolute dry weight]-1) x 100

The absolute dry weight is measured and calculated by, for example, placing cellulosic fibers or the like in a weighing bottle, drying at 105 ° C. for 2 hours, weighing, and subtracting the weight of the weighing bottle previously weighed. can do.

The official weight is determined, for example, by measuring the absolute dry weight of a cellulose fiber or the like placed in a weighing bottle at a temperature of 20 ° C. and a humidity of 65 ° C.
The sample can be measured and calculated by leaving it in an atmosphere of% RH for 24 hours, weighing it, and subtracting the weight of the weighing bin.

For the measurement of the absolute dry weight and the official weight, for example, small pieces of cloth having a size of about 10 cm × 20 cm can be used. Weighing is repeated until the weight becomes constant.

[0023] By introducing a hydrophilic group to introduce cellulosic fibers or cellulosic fiber product of the hydrophilic group, it is possible to hydrophilic treatment. In a preferred embodiment, the hydrophilic groups are introduced into the cellulosic fibers or cellulosic fibrous products, more preferably evenly, throughout the cellulosic fibers. The hydrophilic group can be introduced, for example, in a form in which the hydroxyl group of the cellulose constituting the cellulose fiber is substituted with hydrogen.

As the hydrophilic group, for example, a COOH group, NH
Hydrophilic treatment can be performed by introducing a polar group such as _two groups, SO ₃ group, or a group having these groups. In a preferred embodiment, a group having a COOH group, specifically, a carboxymethyl group is introduced into a cellulosic fiber or a cellulosic fiber product (carboxymethylation: CM conversion).
Preferably, the carboxymethylation degree (CM degree) is set to 0.
It is at least 1 mol%, more preferably at least 1 mol%, at most 10 mol%, more preferably at most 5 mol%.

The degree of CM conversion is the percentage (%) of OH groups of the cellulose subjected to the CM reaction, that is, the OH of untreated cellulose.
The ratio (%) of the number of COO groups after CM conversion to the number of groups is shown.

The number of COO groups is determined by converting all COO groups of the cellulosic fiber or the like to COOH groups, immersing the fibers in an aqueous sodium hydroxide solution (0.1N), and quantifying the amount of Na used for the replacement. Can be. The amount of Na used for the substitution can be determined by titrating an aqueous solution of sodium hydroxide in which cellulosic fibers or the like are immersed using, for example, hydrochloric acid (0.1 N). Specifically, the following measurement method can be adopted.

(1) Cellulose fibers and the like (eg, small pieces of dough) are immersed in 0.3 N hydrochloric acid for 1 hour at a bath ratio of 1:50 and a liquid temperature of 20 ° C. to convert all COO groups to COOH groups and dehydrate. And dried to remove residual HCl, sample approximately 4 g and weigh absolute dry weight (W (g)).

(2) 50 ml of a 0.1N sodium hydroxide aqueous solution weighed accurately by weighing the absolutely weighed cellulose fibers and the like.
(B (ml)) and left overnight at a liquid temperature of 20 ° C. to replace all COOH groups with COONa.

(3) To determine the amount of Na used for the substitution, the solution was titrated with 0.1 N hydrochloric acid, and the titration value was calculated as X (m
l). Phenolphthalein can be used as the indicator.

The degree of CM conversion is determined by the absolute dry weight (W (g)) of the cellulosic fiber or the like, and the volume (B
(Ml)), the volume of hydrochloric acid required for titration (X (ml)),
It can be calculated according to the following formula.

Degree of CM conversion (mol%) = 162.14 × (BX) ÷
[10000W−59.04 × (BX)] ÷ 3 × 100

[0032] CMification by subjecting the cellulose fiber or the cellulose fiber product to a heat treatment in a state where monochloroacetic acid or a treatment solution containing an alkali metal salt of monochloroacetic acid (eg, sodium salt or potassium salt) is brought into contact with the cellulose fiber or the cellulose fiber product. Can be.

The heat treatment temperature is, for example, 40 ° C., preferably
The temperature can be set to 60 ° C. or higher, usually 150 ° C. or lower, preferably 130 ° C. or lower. For example, heat treatment can be performed by steam heating such as a pad steam method. Further, without heat treatment, the substrate may be left at room temperature by a cold pad batch method or the like.

The concentration of monochloroacetic acid or the alkali metal salt of monochloroacetic acid in the treatment liquid may be determined as appropriate under conditions of the treatment liquid so as to obtain a desired degree of processing.
/ L or more, preferably 50 g / l or more, more preferably 10 g / l or more.
0 g / l or more, for example, 500 g / l or less, preferably 30 g / l or less.
It can be 0 g / l or less, more preferably 200 g / l or less.

As the treatment liquid for contacting the cellulosic fiber or the cellulosic fiber product, for example, an alkali metal hydroxide, specifically, sodium hydroxide or the like can be used. For example, when sodium hydroxide is used, the reactivity tends to increase as the NaOH concentration increases. Usually, the NaOH concentration needs to be 20 g / l or more. Go in the direction of hardening.

As a method of bringing the treatment liquid into contact with the cellulosic fiber or the cellulosic fiber product, for example, there is a liquid flow method of rotating in the treatment liquid, or a method of padding (squeezing) after immersion. In terms of use efficiency, it is effective to lower the bath ratio (use ratio of the processing solution), and in this regard, a method of padding after immersion is effective.

The temperature conditions for immersing the cellulosic fiber or cellulosic fiber product in the treatment liquid may be room temperature,
For example, it can be in the range of 5 ° C to 50 ° C.

Grafting of hydrophilic molecules Hydrophilic treatment can be performed by grafting hydrophilic molecules to cellulose fibers or cellulosic fiber products. As a hydrophilic molecule, for example, a hydrophilic treatment can be performed by grafting a vinyl copolymer of methacrylamide.

For example, a monomer that forms a hydrophilic molecule by polymerization (eg, methacrylic acid, methacrylamide, etc.)
Is brought into contact with a cellulosic fiber or a cellulosic fiber product to carry out a polymerization reaction to obtain a cellulosic fiber or a cellulosic fiber product on which a monomer polymer (hydrophilic molecule) is grafted. .

Specifically, for example, a solution containing a monomer (eg, methacrylic acid, methacrylamide, etc.) which polymerizes to form a hydrophilic molecule and a polymerization initiator (eg, ammonium peroxodisulfate, etc.) After dipping and squeezing the cellulose-based fiber or the cellulosic fiber product, and heating, the cellulose-based fiber or the cellulosic fiber product to which the hydrophilic molecule is grafted can be obtained.

The amount of the hydrophilic molecule to be grafted can be appropriately selected in consideration of the type of the hydrophilic molecule and the characteristics (moisture absorption) required for the cellulosic fiber and the like. Or more, preferably 2% or more, usually 30% or less, further 25% or less, particularly 20%
The amount can be as follows.

The graft ratio is calculated from the absolute dry weight of the cellulosic fibers before grafting (absolute dry weight before treatment) and the absolute dry weight after grafting (absolute dry weight after treatment) according to the following formula. can do. Absolute dry weight refers to the weight of a previously weighed weighing bottle after placing cellulosic fibers and the like (eg, small pieces of dough having a size of about 10 cm × 20 cm) in a weighing bottle, drying at 105 ° C. for 2 hours, and weighing. Can be calculated by subtracting

Graft ratio (%) = ([absolute dry weight after treatment]
÷ [absolute dry weight before treatment] -1) × 100

Cellulose fiber or cellulosic fiber
Article The cellulosic fiber or cellulosic fiber product of the present invention (for example, cellulosic fiber for underwear or cellulosic fiber product for cellulosic or underwear made of cellulosic fiber) has a hydrophilic group (for example, COOH group, NH ₂ group and SO _3). One or more selected from the group consisting of a group and a group having one or more selected from these groups), and has a moisture absorption of 7.1% or more, preferably 7.5% or more; %, Preferably 15% or less.

In a preferred embodiment, it has a carboxymethyl group and has a moisture absorption of not less than 7.1%, preferably not less than 7.5%, not more than 20%, preferably not more than 15%. In another embodiment, the compound has a carboxymethyl group and has a degree of CM conversion.
It is 0.1 mol% or more, preferably 1 mol% or more, and 10 mol% or less, preferably 5 mol% or less.

Cellulose fibers or cellulosic fiber products having a carboxymethyl group are subjected to a heat treatment in a state in which the cellulose fibers or the cellulosic fiber products are brought into contact with a treatment solution containing monochloroacetic acid or an alkali metal salt of monochloroacetic acid. Can be manufactured.

In another preferred embodiment, the hydrophilic molecules are grafted and have a moisture absorption of at least 7.1%, preferably at least 7.5%, of at most 20%, preferably of at most 15%. In yet another embodiment, the hydrophilic molecules are grafted, and the graft ratio is 1% or more, preferably 2% or more, 30% or less, preferably 25% or less, more preferably 20% or less.

As the hydrophilic molecule, there is a polymer or copolymer of methacrylic acid or methacrylamide or a copolymer of at least one of methacrylic acid or methacrylamide and another monomer.

The present invention is particularly effective for cellulosic fibers or cellulosic fiber products having a whiteness of 100 or more, particularly 120 or more (usually 150 or less, and even 140 or less). Whiteness is a value calculated from the L ^* value and b ^* value of the CIELAB color system by the following formula. The L ^* value and the b ^* value can be determined, for example, by performing colorimetry with a colorimeter (Macbeth WHITE-EYE3000).

Whiteness = L ^* value−3 × b ^* value

[0051]

[Examples] [Confirmation test of hydrophilization treatment and suppression of yellowing] Examples 1 to 3 [CM conversion: liquid flow method] and Comparative Example 1 Using a normal cotton cloth (original cloth 1) as an original cloth, monochloroacetic acid After immersing in an aqueous solution [treatment liquid] of sodium (175 g / l) and sodium hydroxide (175-60 g / l) (bath ratio 1:20), heating at 60 ° C. for 1 hour, and then washing with water To remove unreacted substances.

With respect to each of the obtained hydrophilized cotton cloths, 30 g of artificial sweat containing 40.6% of oleic acid, 22.4% of triolein, 17.5% of cholesterol oleate, 3.6% of liquid paraffin, 2.3% of cholesterol and 10.0% of gelatin as main components. After being immersed in 1 solution, it was squeezed at a squeezing ratio of 130%, dried at 105 ° C. for 30 minutes, washed with ordinary households, and then dried in the sun.

The above operations of immersion in artificial sweat, squeezing, drying, washing, and sun drying were repeated five times, and the change in whiteness of each hydrophilized cotton cloth was examined (a test for confirming yellowing inhibition: Artificial wear test).

The concentration of sodium hydroxide (NaOH) in the treatment solution and the carboxymethyl (C
M) Degree of conversion, moisture absorption and whiteness (result of artificial wear test) are shown in Table 1. As Comparative Example 1, the results for the original dough 1 (untreated) are shown.

Examples 4 to 6 [Commercialization: pad steam method]
(PS method)] and Comparative Example 2 An ordinary cotton cloth (original fabric 2) was used as the original fabric, and an aqueous solution of sodium monochloroacetate (175 g / l) and sodium hydroxide (175 to 60 g / l) [treatment solution] Immersed in water (room temperature), squeezed with a padder, and then steamed (100 ° C)
After reacting by heat treatment for a minute, unreacted substances were removed by washing with water.

Table 1 shows the concentration of sodium hydroxide (NaOH) in the treatment liquid, and the degree of CM conversion, moisture absorption and whiteness (result of an artificial wear test) of the obtained hydrophilized cotton cloth. As Comparative Example 2, the results for the original dough 2 (untreated) are shown.

Example 7 [CM conversion: pad batch method (PB
Method)] Using an ordinary cotton cloth (original cloth 2) as the original cloth, immersing it in an aqueous solution [treatment liquid] of sodium monochloroacetate (175 g / l) and sodium hydroxide (75 g / l) (normal temperature)
After squeezing with a padder, the mixture was left standing at room temperature (20 ° C.) for 24 hours to react, and then washed with water to remove unreacted substances. Table 1 shows the degree of CM conversion, the moisture absorption rate, and the whiteness (results of an artificial wear test) of the obtained hydrophilized cotton cloth.

[0058]

[Table 1] CM NaOH concentration CM conversion Moisture absorption:% whiteness (decreased whiteness) method g / l mol% (ratio to untreated) Comparative example 1 5 times before test Comparative example 1 Original dough 1 (untreated) 7.0 (100) 135.4 113.8 (21.6) Example 1 Liquid flow method 175 5.7 14.9 (214) 135.3 133.5 (1.8) Example 2 Liquid flow method 100 4.2 11.4 (162) 136.0 132.2
(3.8) Example 3 Liquid Flow Method 60 2.9 7.7 (110) 132.4 122.0 (10.
4) Comparative Example 2 Original dough 2 (untreated) 7.0 (100) 134.7 112.4 (22.3) Example 4 PS method 175 4.4 13.9 (199) 131.5 131.0 (0.5) Example 5 PS method 100 3.5 10.6 (151) 132.0 127.8 (4.2) Example 6 PS method 60 2.4 7.8 (111) 132.4 120.5 (11.9) Example 7 PB method 75 2.7 9.4 (130) 134.9 124.2 (10.7)

As described above, Examples 1 to 7 and Comparative Example 1
As is clear from FIG. 2, the decrease in whiteness of the hydrophilized cotton fabric of the present invention is smaller than that of the untreated original fabric. Further, the higher the degree of processing, the greater the effect.

Example 8 [Graft processing: methacrylic acid]
And Comparative Example 3 A 100% cotton milled knitted fabric (refined dough 3) after refining and bleaching having a whiteness of 134.1 was used as the dough, and a methacrylic acid monomer (150 g / l) and ammonium peroxodisulfate [initiator] (7.5 g) / L) aqueous solution (treatment liquid) at room temperature (20
C) for 1 minute, squeezed with pu 120%,
Steaming was performed for 10 minutes, and washing with water was performed to remove unreacted substances.
Table 2 shows the graft ratio, moisture absorption rate, and whiteness (result of an artificial wear test) of the obtained hydrophilized cotton cloth. As Comparative Example 3, the results for the original dough 3 (untreated) are shown.

Example 9 [Graft processing: methacrylamide ]
C) As a treatment liquid, a methacrylamide monomer (150 g /
l) and ammonium peroxodisulfate [initiator] (7.
Example 8 was repeated except that an aqueous solution of 5 g / l) was used. Table 2 shows the results.

Example 10 [Graft processing: methacrylamide ]
C) As a treatment liquid, a methacrylamide monomer (200 g /
l) and ammonium peroxodisulfate [initiator] (10
g / l) except that an aqueous solution (g / l) was used. Table 2 shows the results.

[0063]

[Table 2] Monomer (concentration: g / l) Graph Moisture absorption rate:% whiteness (change) To rate (relative to untreated ratio) Before and after 5 tests Example 8 Methacrylic acid (150) 2.1% 7.8 (111) 131.9 121.1 (10.8) Example 9 Methacrylamide (150) 12.3% 8.0 (114) 133.7 121.9 (11.8) Example 10 Methacrylamide (200) 19.0% 9.8 (140) 132.8 126.4 (6.4) Comparative Example 3 Processing) 7.0 (100) 134.1 113.7 (20.4)

[Durability] Each of the hydrophilized cotton fabrics of Examples 1 to 10 was washed 100 times, and the degree of CM conversion or graft ratio (working degree) was measured after washing 50 times and after washing 100 times, respectively. The degree of processing did not change.

[Whiteness Test: Wearing Test] Example 11 [Carboxymethylation] The hydrophilized cotton cloth of Example 3 was used for the left half, and the untreated cotton cloth of Comparative Example 4 (original cloth 4) was used for the right half. Then, a short-sleeved shirt (underwear) for an adult man was sewn and tested for white resistance by actual wearing.

That is, 10 adult males were used as monitors for 30 wears each, washed and dried once each time they were worn, and the left half (hydrophilicized cotton cloth) and the right half (non-treated) The whiteness of the treated cotton cloth was measured.

The difference in whiteness of the 10th time between the processed part and the unprocessed part is 5 points on average, and the difference in the whiteness of the 30th time is 12 points. In this case, the reduction rate of the whiteness of the untreated portion was 53%.

[0068]

[Table 3]

Example 12 [Grafting] A hydrophilized cotton cloth (graft rate 14%, moisture absorption rate 9.1%) grafted with methacrylamide in the same manner as in Example 9 or 10 was used as the hydrophilized cotton cloth. Example 1
In the same manner as in 1, the white resistance was tested. Table 4 shows the results. As Comparative Example 5, the results for an untreated cotton cloth (base cloth 5) are shown.

[0070]

[Table 4] Whiteness (reduced whiteness) wear frequency 0 times 10 times 30 times Example 9 (grafted portion) 132.0 125.6 (6.4) 110.5 (21.5) Comparative Example 3 (untreated portion) 133.8 120.5 (13.3) 100.4 (33.4)

[Skin Damage Test] When testing the whiteness resistance, a skin damage test was performed by observing the skin damage of each monitor. As a result, there was no substantial difference between the left half and the right half. It was confirmed that there was no problem of skin damage for the hydrophilized cotton cloth.

[Distribution yellowing test] The hydrophilized cotton cloth and the untreated cotton cloth (Comparative Example 3) of Example 1 (CM conversion) and Example 9 (methacrylamide graft) were subjected to JIS0855.
A distribution yellowing test was conducted in accordance with the "Dyeing Fastness Test Method for Nitrogen Oxides".

The degree of yellowing can be measured with a colorimeter (Macbeth WHITE-EY)
E3000), and the evaluation was made based on the change (Δb ^* value) of the b ^* value of the CIELAB color system before and after the test. The larger the Δb ^* value, the greater the yellowing.

Δb ^* value = [b ^* value before test] − [b ^* value after test]

The Δb ^* value of Comparative Example 3 (untreated cotton cloth)
0.9 in Example 1 (CM conversion) and 0.9 in Example 8 (methacrylamide graft).

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Hideo Sukeda 1st Ikura Shinmachi Ishiburo, Ayabe-shi, Kyoto Gunze Co., Ltd. Research and Development Department (72) Inventor Nobuo Akida 262 Sozu, Miyazu-shi, Kyoto Gunze Apparel Within the Business Division (72) Inventor Shinobu Tabata 262, So, Miyazu-shi, Kyoto Gunze Co., Ltd.F-Term within the Apparel Business Division (Reference) 3B029 HA01 HB00 HB03 4L033 AA02 AB01 AC07 BA17 BA20 BA76 CA23

Claims (21)

[Claims] 1. A method of imparting a wearing yellowing suppressing function, comprising subjecting a cellulosic fiber or a cellulosic fiber product to a hydrophilic treatment. 2. The method according to claim 1, wherein the cellulosic fiber or the cellulosic fiber product is subjected to a hydrophilic treatment so as to have a moisture absorption of 7.1 to 20%. 3. The method according to claim 1, wherein a hydrophilic group is introduced into the cellulosic fiber or the cellulosic fiber product to perform a hydrophilic treatment.
The method described in. 4. The method according to claim 1, wherein the hydrophilic group is a COOH group, an NH ₂ group or
O ₃ group as well as method of claim 3 is one or more selected from the group consisting of one or a group having 2 or more selected from these. 5. The method according to claim 4, wherein the COOH group is introduced by carboxymethylating the cellulosic fiber or cellulosic fiber product. 6. The degree of carboxymethylation is 0.1 to 10 mol%.
The method of claim 5, wherein 7. The method according to claim 5, wherein the heat treatment is carried out in a state in which a treatment liquid containing monochloroacetic acid or an alkali metal salt of monochloroacetic acid is brought into contact with the cellulosic fiber or the cellulosic fiber product. . 8. The method according to claim 1, wherein the hydrophilic treatment is performed by grafting a hydrophilic molecule to the cellulosic fiber or cellulosic fiber product. 9. The method according to claim 8, wherein the hydrophilic molecules are grafted by polymerizing a monomer which forms a hydrophilic molecule by polymerization to make contact with the cellulosic fiber or cellulosic fiber product. . 10. The monomer which polymerizes to form a hydrophilic molecule is methacrylic acid or methacrylamide.
The method described in. 11. The cellulosic fiber or cellulosic fiber product is a cellulosic fiber or cellulosic fiber product or cellulosic fiber underwear for underwear.
11. The method according to any one of 10 above. 12. A cellulosic fiber or cellulosic fiber product having a hydrophilic group and having a moisture absorption of 7.1 to 20%. 13. The hydrophilic group is one or more selected from the group consisting of a COOH group, an NH ₂ group, and an SO ₃ group, and a group having one or more selected from these groups. Item 13. Cellulosic fiber or cellulosic fiber product according to Item 12. 14. It has a carboxymethyl group and has a moisture absorption rate
A cellulosic fiber or cellulosic fiber product of 7.1 to 20%. 15. A cellulosic fiber or cellulosic fiber product having a carboxymethyl group and having a carboxymethylation degree of 0.1 to 10 mol%. 16. The cellulosic fiber according to claim 14 or 15, wherein the cellulosic fiber or the cellulosic fiber product is subjected to a heat treatment in a state where monochloroacetic acid or a treatment solution containing an alkali metal salt of monochloroacetic acid is brought into contact with the cellulose fiber. Cellulosic fiber products. 17. A hydrophilic molecule is grafted and has a moisture absorption of 7.
Cellulose fiber or cellulosic fiber product of 1 to 20%. 18. A cellulosic fiber or cellulosic fiber product having a hydrophilic molecule grafted thereon and having a graft ratio of 1 to 30%. 19. The method according to claim 17, wherein the hydrophilic molecule is a polymer or copolymer of methacrylic acid or methacrylamide, or a copolymer of at least one of methacrylic acid or methacrylamide and another monomer. 4. The cellulosic fiber or cellulosic fiber product according to item 1. 20. The cellulosic fiber or cellulosic fiber product is a cellulosic fiber or cellulosic fiber product or cellulosic fiber underwear for underwear.
20. A cellulosic fiber or a cellulosic fiber product according to any one of items 1 to 19. 21. The whiteness degree is 100 or more.
0. The cellulosic fiber or cellulosic fiber product according to any one of the above.