Cellulose fiber garment and method for producing cellulose fiber garment

Abstract

To provide a cellulose fiber garment with a superior moisturizing effect and a method for producing the cellulose fiber garment.SOLUTION: A cellulose fiber garment contains cellulose fibers, where at least a portion of cellulose constituting the cellulose fibers is modified by phosphate esterification.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a cellulose fiber garment having excellent moisture retention and a method for producing the same. [Background technology]

[0002] Cotton clothing products (cellulose fiber clothing) such as underwear are required to have high moisture absorption and release properties. One method for obtaining cotton clothing products (cellulose fiber clothing) with such high moisture absorption and release properties is to subject the raw cellulose fibers to a hydrophilic treatment. There are various known methods for subjecting cellulose fibers to a hydrophilic treatment, and a representative example is a method in which the hydroxyl groups of cellulose are oxidized to carboxyl groups.

[0003] A specific method for oxidizing hydroxyl groups in cellulose to carboxyl groups is known, for example, by carrying out an oxidation treatment in which raw cellulose fibers are oxidized in a reaction solution containing an N-oxyl compound such as 2,2,6,6-tetramethylpiperidine-N-oxyl (TEMPO) and a halogen-based oxidizing agent in the presence of a co-catalyst (e.g., Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2011 / 024807 Summary of the Invention [Problem to be solved by the invention]

[0005] In addition to the above-mentioned moisture absorption and release properties, the properties required for clothing products include moisture retention. However, conventional cotton clothing products do not have sufficient moisture retention, and cotton clothing products with high moisture retention are required from the viewpoint of beauty and the like.

[0006] In view of the above-mentioned current situation, an object of the present invention is to provide a cellulose fiber clothing having excellent moisture retention and a method for producing the cellulose fiber clothing. [Means for solving the problem]

[0007] The present invention includes the following Disclosures 1 to 6. The present invention will be described in detail below. [Disclosure 1] A cellulose fiber garment comprising cellulose fibers, characterized in that at least a portion of the cellulose constituting the cellulose fibers is phosphoric acid esterified. [Disclosure 2] The cellulose fiber clothing according to Disclosure 1, characterized in that the amount of phosphate ester groups introduced into the cellulose is 0.2 mmol / g or more. [Disclosure 3] 3. The cellulose fiber clothing according to Disclosure 1 or 2, characterized in that the degree of polymerization of cellulose is 800 or more. [Disclosure 4] The cellulose fiber clothing according to any one of Disclosures 1 to 3, wherein the content of cellulose fibers in the fibers contained in the cellulose fiber clothing is 10% or more. [Disclosure 5] A method for producing cellulose fiber clothing, comprising a padding step of immersing a fabric made of cellulose fibers in a reaction liquid containing urea and a phosphoric acid compound and then squeezing the fabric, an aging step of drying the fabric after the padding step, and a reaction step of heating the fabric after the aging step. [Disclosure 6] The method for producing cellulose fiber clothing according to Disclosure 5, wherein the urea content in the reaction solution is 1% owf or more.

[0008] As a result of extensive research, the present inventors have discovered that moisture retention can be improved by phosphorylating at least a portion of the hydroxy groups contained in the cellulose of cellulose fiber clothing, and have thus completed the present invention.

[0009] The cellulosic fiber garment of the present invention comprises cellulosic fibers. The raw material of the cellulose fiber may be natural cellulose fiber such as plant, animal, or bacterial gel, or may be regenerated cellulose fiber. Specifically, for example, natural cellulose fiber such as cotton, hemp, pulp, or bacterial cellulose, or regenerated cellulose fiber such as rayon or cupra can be used. Examples of the rayon include viscose rayon, cuprammonium rayon, polynosic rayon, etc. Among these, cotton is preferred from the viewpoints of strength and feel.

[0010] The cellulose fibers may be in the form of filaments, staples, strings, and other threads, as well as woven or knitted fabrics and nonwoven fabrics. The fiber structure may be mixed fibers, mixed spinning, mixed weaving, interwoven, or interknitted.

[0011] The content of cellulose fibers in the fibers contained in the cellulose fiber clothing of the present invention is not particularly limited, but is preferably 10% or more, more preferably 30% or more, and even more preferably 50% or more. The upper limit of the content of the cellulose fibers is not limited, and since the cellulose fibers have high moisture retention and do not need to be supplemented with other fibers, the content of the cellulose fibers may be 100%, for example, 100% cotton.

[0012] In the cellulose fiber clothing of the present invention, at least a portion of the cellulose constituting the cellulose fibers is phosphated. By phosphorylating at least a portion of the hydroxyl groups of the cellulose constituting the cellulose fiber, high moisture retention can be imparted to the cellulose. The hydroxyl groups of the cellulose may be phosphorylated at any position, or all of the hydroxyl groups may be phosphorylated.

[0013] The cellulose preferably has an introduction amount of phosphate ester groups of 0.2 mmol / g or more. The amount of phosphoric acid ester group introduced, that is, the amount of hydroxyl group in cellulose substituted with phosphoric acid ester group, is within the above range, so that the moisture retention can be further improved. The amount of phosphoric acid ester group introduced in the cellulose is more preferably 0.3 mmol / g or more, and even more preferably 0.5 mmol / g or more. The upper limit of the degree of substitution of the phosphoric acid ester group in the cellulose is not particularly limited. The amount of phosphoric acid ester group introduced in the cellulose can be measured by the following method. A sample of phosphate ester group-containing cellulose fiber, the dry weight of which has been precisely weighed, is placed in water, and the pH is adjusted to about 2.5 with a 0.1 M aqueous hydrochloric acid solution, after which a 0.05 M aqueous sodium hydroxide solution is dropped and the electrical conductivity is measured. Measurements are continued until the pH reaches 11. The amount of functional groups is then determined using the following formula from the amount of sodium hydroxide (V) consumed in the neutralization stage of the weak acid, where the change in electrical conductivity is gradual. This amount of functional groups is the amount of phosphate ester groups. Amount of functional group (mmol / g) = V (ml) × 0.05 / mass of cellulose (g)

[0014] The above cellulose preferably has a degree of polymerization of 800 or more. When the degree of polymerization of cellulose is within the above range, the clothing can have superior strength and durability. The degree of polymerization of the cellulose is more preferably 900 or more, and even more preferably 1000 or more. The degree of polymerization of the cellulose can be measured according to Japanese Patent No. 5406152.

[0015] Specific types of cellulose fiber clothing of the present invention include clothing for going out, sportswear, homewear, relaxation wear, pajamas, nightwear, underwear, office wear, work clothes, foodservice coats, nursing coats, patient wear, care wear, school uniforms, kitchen wear, pantyhose, tights, leggings, socks, coats, jackets, trousers, skirts, dress shirts, knit shirts, blouses, sweaters, cardigans, nightwear, supporters, belly warmers, shorts, badges, petticoats, hats, scarves, mufflers, collars, gloves, clothing linings, clothing interlinings, clothing padding, work clothes, aprons, foodservice coats, nursing coats, patient wear, care wear, kitchen wear, uniforms, school uniforms, etc., as well as products such as curtains, futon fabrics, futon batting, pillow covers, sheets, mats, carpets, towels, handkerchiefs, kotatsu covers, sofa coverings, sofa covers, cushion covers, toilet seat covers, toilet seat mats, tablecloths, etc. The above-mentioned cellulose fiber products also include those in the form of fiber products used in the industrial materials field, such as wall cloth, floor coverings, filters, etc. In particular, the cellulose fiber clothing of the present invention can be made of cotton and has excellent moisture retention, so that it is suitable for clothing that comes into direct contact with the skin, such as underwear.

[0016] The method for producing the cellulose fiber clothing of the present invention is not particularly limited, but a production method in which the cellulose fiber fabric is immersed in a reaction liquid, padded, dried, and then heat-treated is preferred, because phosphate esterification is possible after the cellulose fiber clothing is made, and a large amount of phosphate ester groups can be introduced without causing any substantial change in the shape of the cellulose fiber clothing. The present invention also provides a method for producing cellulose fiber clothing, which comprises a padding step in which a fabric made of cellulose fibers is immersed in a reaction liquid containing urea and a phosphoric acid compound and then wringed out, an aging step in which the fabric after the padding step is dried, and a reaction step in which the fabric after the aging step is heated.

[0017] The method for producing cellulose fiber clothing of the present invention first involves a padding step in which a fabric made of cellulose fibers is immersed in a reaction liquid containing urea and a phosphoric acid compound and then wrung out. By immersing the fabric in the reaction solution and then wringing it, the reaction solution can be uniformly permeated throughout the entire fabric. In addition, in the method for producing cellulose fiber clothing of the present invention, the reaction solution contains urea. By including urea in the reaction solution, the cellulose fibers are loosened, so that the reaction solution can permeate every corner of the cellulose fibers, and a sufficient amount of phosphate ester groups can be introduced in the subsequent reaction step. The method and conditions for immersing and wringing the fabric can be any conventionally known method without any particular limitations. In this case, the term "fabric" includes not only a roll of cloth but also clothing that has already been made. The specific types of the cellulose fibers and cellulose fiber clothing are the same as those of the cellulose fiber clothing of the present invention.

[0018] The urea content in the reaction solution is preferably 1% owf or more. When the urea content in the reaction solution is within the above range, the cellulose fibers are appropriately loosened, the phosphorylation reaction is further promoted, and more phosphoric acid ester groups can be introduced into the cellulose. In addition, since no strong acid or strong alkali is used in the reaction solution, the decomposition of cellulose and the yellowing of the fibers can be further suppressed. The urea content in the reaction solution is more preferably 2% owf or more, and even more preferably 5% owf or more. The upper limit of the urea content in the reaction solution is preferably 50% owf or less from the viewpoint of further suppressing the decomposition of cellulose and the yellowing of the fibers. In this specification, the unit "% owf" means weight % relative to the fabric weight.

[0019] Examples of the phosphoric acid compound include phosphoric acid, phosphorous acid, ammonium dihydrogen phosphate, diammonium phosphate, etc. Among these, diammonium phosphate is preferred because it allows the introduction of a larger number of phosphate ester groups.

[0020] The content of the phosphoric acid compound in the reaction solution is preferably 1% owf or more. When the content of the phosphoric acid compound in the reaction solution is within the above range, the phosphoric acid esterification reaction proceeds sufficiently, so that a large number of phosphoric acid ester groups can be introduced into the cellulose fibers. The content of the phosphoric acid compound in the reaction solution is more preferably 2% owf or more, and even more preferably 5% owf or more. The upper limit of the content of the phosphoric acid compound in the reaction solution is not particularly limited, but it is preferably 50% owf or less from the viewpoint of cost.

[0021] The solvent for the reaction solution is not particularly limited as long as it can dissolve the urea and phosphoric acid compound, but water is preferred from the viewpoints of cost and ease of processing.

[0022] In the method for producing cellulose fiber clothing of the present invention, an aging step is then carried out in which the fabric after the padding step is dried. From the viewpoint of removing moisture contained in the dough, the aging temperature is preferably 60° C. or higher, more preferably 65° C. or higher, and preferably 120° C. or lower, more preferably 100° C. or lower. From the same viewpoint, the aging time is preferably 3 minutes or longer, more preferably 5 minutes or longer, and preferably 120 minutes or lower, more preferably 90 minutes or lower.

[0023] In the method for producing cellulose fiber clothing of the present invention, a reaction step is then carried out in which the fabric after the aging step is heated. By heating the fabric after the aging process, the phosphoric acid compound reacts with the cellulose fibers of the fabric, and the hydroxyl groups of the cellulose in the cellulose fibers are converted to phosphoric acid esters. The heating temperature is preferably 100°C or higher, more preferably 130°C or higher, from the viewpoint of allowing the reaction to proceed sufficiently. In addition, the heating temperature is preferably 160°C or lower, from the viewpoint of suppressing damage to the fabric. From the same viewpoint, the heating time is preferably 1 minute or longer, more preferably 5 minutes or longer, preferably 60 minutes or shorter, and more preferably 30 minutes or shorter. Effect of the Invention

[0024] According to the present invention, it is possible to provide cellulose fiber clothing having excellent moisture retention and a method for producing the cellulose fiber clothing. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0025] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0026] Example 1 As the raw cellulose fiber clothing, a circular knit fabric (100% cotton) made by milling knitting 40-count cotton fibers was prepared. In addition, a reaction solution (equivalent to urea 20% owf, diammonium phosphate 10% owf) was prepared by dissolving 80g of urea and 40g of diammonium phosphate in 280g of water for 40g of circular knit fabric. First, the fabric was immersed in the reaction solution at a bath ratio of 1:5 (fabric weight: reaction solution weight) and padded with a mangle. Next, the fabric was aged for 1 hour in an incubator at 80°C, and then heated for 30 minutes in an incubator at 150°C to react the cellulose fiber with diammonium phosphate. The heated fabric was washed with water and dried to obtain cellulose fiber clothing.

[0027] (Examples 2 to 4) Cellulose fiber clothing was obtained in the same manner as in Example 1, except that the composition of the reaction solution and the immersion conditions were as shown in Table 1.

[0028] Comparative Example 1 The raw cellulose fiber clothing of Example 1 was used as it was.

[0029] <Evaluation> The cellulose fiber clothing obtained in the Examples and Comparative Examples was evaluated by the following methods. The results are shown in Table 1.

[0030] (1) Moisture absorption rate evaluation The moisture absorption rate of the resulting cellulose fiber clothing was measured according to the method of JIS L-1096 8.10.

[0031] (2) Evaluation of the amount of phosphate ester groups introduced The obtained cellulose fiber clothing was pulverized to prepare a measurement sample. The dry weight of the measurement sample was precisely weighed, placed in water, and the pH was adjusted to about 2.5 with 0.1 M hydrochloric acid solution, after which 0.05 M sodium hydroxide solution was added dropwise to measure the electrical conductivity. The measurement was continued until the pH reached 11. The amount of functional groups (amount of introduced phosphate ester groups) was determined using the following formula from the amount of sodium hydroxide (V) consumed in the neutralization stage of the weak acid, where the change in electrical conductivity is gradual. Amount of functional group (mmol / g) = V (ml) × 0.05 / mass of cellulose (g)

[0032] (3) Evaluation of the degree of polymerization of cellulose The cellulose fiber clothing used in the moisture absorption rate measurement and allowed to absorb moisture was pulverized for 30 seconds at a rotation speed of 25,000 rpm using a fine grinder (WARING J-SPEC BLENDER, manufactured by Osaka Chemical Co., Ltd.). After the crushing, 0.0400 g of a measurement sample was accurately weighed from the pulverized cellulose fiber clothing, and the weight of cellulose was calculated from the weighed value and the moisture absorption rate according to the following formula. Cellulose weight = weighed value × [1-(moisture absorption rate (%) / 100)] Thereafter, the measurement sample was placed in an Erlenmeyer flask and wrapped.

[0033] In a 1L measuring flask, 48.78g of Cu(OH)2 [MW=97.56] and about 250mL of ion-exchanged water were added, and while cooling with ice water, 67.0mL of ethylenediamine (MW=60.1, d=0.898) was added. After that, it was thoroughly stirred and dissolved, and then ion-exchanged water was added to make 1L, to prepare a 0.5mol / L copper ethylenediamine solution (Cu(EDA)2(OH)2). At this time, it was stirred under sealed conditions to avoid contact with air, and it was stored covered in a black bag to prevent deterioration due to light such as sunlight.

[0034] 20 mL of 0.5 mol / L copper ethylenediamine solution was added to the Erlenmeyer flask containing the crushed sample, and the solution was prepared by dissolving the sample with a triangular stirrer. 10 mL of the solution was poured into a Cannon-Fenske viscometer (capillary viscometer, manufactured by Sogo Rikagaku Glass Works, Ltd.), placed in a thermostatic water bath set at 25°C, and left to stand for 3 minutes until the temperature reached equilibrium, at which point the viscosity was measured. The viscosity was measured by pushing the solution up beyond the line on the globule using a pipetter, removing the pipetter, and measuring the time from when the liquid level passed the upper mark to when it passed the lower mark with a stopwatch. The degree of polymerization of cellulose was measured using the Staudinger's empirical rule from the obtained measurement time and the weight of cellulose. The viscosity measurement was repeated three times, and the average value was taken as the viscosity value.

[0035] (4) Evaluation of whiteness loss The difference in whiteness of each sample before and after drying, calculated as L*-3b* according to the CIELAB color system, was measured to evaluate the degree of whiteness loss. Note that the whiteness after drying is the whiteness after measuring the absolute dry weight based on "JIS L-0105 4.3". The measurement was performed on a small area using a Macbeth WHITE-EYE3000 manufactured by Kollmorgen Instruments Corporation.

[0036] (5) Evaluation of the rate of change in stratum corneum moisture content and water loss rate after 14 days According to the measurement method in Chapter 1, Section 3 of "Usefulness of Cosmetics - Progress in Evaluation Technology and Future Prospects" (Takeda Katsuyuki et al., Yakuji Nipposha, 2001), the stratum corneum moisture content and moisture evaporation amount were measured after 14 days, and the change rate was calculated based on the initial stratum corneum moisture content and moisture evaporation amount to evaluate the moisturizing properties of the obtained cellulose fiber clothing. The measurement position was the inside of the forearm when the cellulose fiber clothing obtained in the examples and comparative examples was worn for 14 days for 8 hours or more per day. The stratum corneum moisture content was obtained by measuring the skin surface conductance using a skin surface stratum corneum moisture content measuring device (Skicon-200, Yayoi Co., Ltd.). The moisture evaporation amount was measured using a Tewameter (registered trademark). The larger the value of the stratum corneum moisture content change rate, and the smaller the value (absolute value) of the moisture evaporation change rate, the higher the moisturizing properties.

[0037] [Table 1] [Industrial Applicability]

[0038] According to the present invention, it is possible to provide cellulose fiber clothing having excellent moisture retention and a method for producing the cellulose fiber clothing.

Claims

1. A cellulose fiber garment comprising cellulose fibers, characterized in that at least a portion of the cellulose constituting the cellulose fibers is phosphoric acid esterified.

2. 2. The cellulose fiber clothing according to claim 1, wherein the amount of phosphate ester groups introduced into the cellulose is 0.2 mmol / g or more.

3. 3. The cellulose fiber clothing according to claim 1, wherein the degree of polymerization of the cellulose is 800 or more.

4. 3. The cellulose fiber clothing according to claim 1 or 2, characterized in that the content of cellulose fibers in the fibers contained in the cellulose fiber clothing is 10% or more.

5. A method for producing cellulose fiber clothing, comprising a padding step of immersing a fabric made of cellulose fibers in a reaction liquid containing urea and a phosphoric acid compound and then squeezing the fabric, an aging step of drying the fabric after the padding step, and a reaction step of heating the fabric after the aging step.

6. 6. The method for producing cellulose fiber clothing according to claim 5, wherein the urea content in the reaction solution is 1% owf or more.

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