JP2014201844A - Fluorescent whitened highly cross-linked polyacrylate fiber, manufacturing method therefor, and fiber structure comprising the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide: a highly cross-linked polyacrylate fiber in which red is reduced and whiteness increased, and the amount of heat generated and the amount of moisture adsorbed when gas phase moisture is adsorbed have been further improved; and a fiber structure comprising the same.SOLUTION: For a fluorescent whitened highly cross-linked polyacrylate fiber of this invention, an anionic fluorescent whitener is adhered to a highly cross-linked polyacrylate fiber, which adsorbs gas phase moisture and generates heat. The fluorescent whitened highly cross-linked polyacrylate fiber is obtained by bringing a highly cross-linked polyacrylate fiber, which adsorbs gas phase moisture and generates heat, into contact with an aqueous dispersion containing an anionic fluorescent whitener and then treating for 20 seconds to 120 minutes at 10-200°C. A fiber structure of this invention comprises the fluorescent whitened highly cross-linked polyacrylate fiber. The fiber has one or more points to be convexed upward within a wavelength range of 220 to 300 nm, in an absorbance analysis of a liquid obtained after extracting the fiber with water with temperature of 90 to 95°C for 60 minutes.

Description

  The present invention relates to a highly cross-linked polyacrylate fiber to which a specific optical brightener is attached, a method for producing the same, and a fiber structure including the same.

  The exothermic fiber using heat generated when adsorbing moisture (adsorption heat) has high heat retention and is often used mainly for sports clothing such as winter clothing and mountain climbing. A typical fiber that generates heat by this heat of adsorption is a highly crosslinked polyacrylate fiber (Patent Document 1). This fiber is a fiber obtained by modifying acrylic fiber as a raw material, hydrophilizing the molecule, and at the same time highly cross-linking, and forms a fiber form with high hygroscopicity and suppressed swelling. A general highly crosslinked polyacrylate fiber can be obtained by crosslinking acrylic fiber with hydrazine or the like to suppress swelling when wet and introduce a hydrophilic group. The hydrophilic group can be introduced by hydrolyzing a part of the functional group of the fiber to form a carboxyl group (—COOH) and / or an alkali metal salt type carboxyl group (for example, —COONa).

  The conventional highly cross-linked polyacrylate fiber is tinged with red, and there is a problem that redness increases as the wearing period becomes longer. In order to solve this problem, there is a proposal that a part of the carboxyl group is a metal salt in the raw cotton manufacturing process (Patent Documents 2 and 3).

Japanese Patent Publication No. 7-59762 JP 2000-2303353 A JP 2002-294556 A

  However, the conventional highly cross-linked polyacrylate fiber is still reddish, and there is a problem that redness increases as the wearing period becomes longer, and there is still a demand for solving this problem from the market. In addition, there is a demand for further improving the amount of heat generated and the amount of moisture adsorbed when moisture in the gas phase is adsorbed.

  In order to solve the above-described conventional problems, the present invention provides a highly crosslinked polyacrylate fiber having a low red color, a high whiteness, and a further improved heat generation amount and moisture adsorption amount when moisture in the gas phase is adsorbed, and its A manufacturing method and a fiber structure including the same are provided.

  The fluorescent whitening highly cross-linked polyacrylate fiber of the present invention is characterized in that an anionic fluorescent whitening agent is attached to a highly cross-linked polyacrylate fiber that generates heat by adsorbing moisture in the gas phase.

  In the method for producing a fluorescent whitening highly crosslinked polyacrylate fiber of the present invention, a highly crosslinked polyacrylate fiber that generates heat by adsorbing moisture in a gas phase is brought into contact with an aqueous dispersion containing an anionic fluorescent whitening agent. A fluorescent whitening highly crosslinked polyacrylate fiber is obtained by treatment at 200 ° C. for 20 seconds to 120 minutes.

  The fiber structure of the present invention includes the above-described fluorescent whitening highly crosslinked polyacrylate fiber.

  The present invention relates to a highly crosslinked polyacrylate fiber having a low red color and high whiteness by attaching an anionic fluorescent whitening agent to a highly crosslinked polyacrylate fiber that generates heat by adsorbing moisture in the gas phase. Can provide clothing including Further, the amount of heat generated when moisture in the gas phase is adsorbed is higher than that of a fiber (unprocessed product) to which an anionic fluorescent whitening agent is not attached, and the amount of moisture adsorption is also increased. In the above, the effect of lowering the redness of the fiber and increasing the whiteness is a direct effect by attaching an anionic fluorescent whitening agent, but the moisture adsorption amount and the hygroscopic heat generation amount are increased. In addition to hydrophilic groups such as carboxyl groups and / or salt-type carboxyl groups possessed by acrylate fibers, hydrophilic groups such as sulfonates possessed by anionic fluorescent brighteners act synergistically to produce moisture in the gas phase. This is probably due to the increased affinity for.

FIG. 1 is an absorbance-wavelength graph of an extract from a fluorescent whitened highly crosslinked polyacrylate fiber according to an example of the present invention.

  The present inventor said that an anionic fluorescent whitening agent that is not normally used for acrylic fibers can be applied to highly crosslinked polyacrylate fibers to eliminate red color and provide fibers with high whiteness. The idea was examined. As a result, surprisingly, the red color of the highly cross-linked polyacrylate fiber disappears, and a fiber with high whiteness is obtained, and the calorific value when adsorbing gas phase moisture does not attach the anionic fluorescent whitening agent. It was found that the effect was high compared to the fiber (unprocessed product) and the moisture adsorption amount was high. Increasing the amount of heat generated and the amount of moisture adsorbed when moisture in the gas phase is adsorbed is a great advantage in creating more comfortable clothes. Moreover, if whiteness is high, the value as a product will become high.

  The highly cross-linked polyacrylate fiber used in the present invention is a fiber obtained by making the fiber hydrophilic and highly cross-linked by modifying the acrylic fiber. That is, a hydrazine compound is crosslinked and introduced into an acrylic fiber, followed by hydrolysis and reduction treatment. Thereby, it becomes a fiber which has a carboxyl group and / or a salt type carboxyl group which are hydrophilic groups. As another example of the hydrophilic group, a sulfonic acid group and / or a sulfonic acid group may be used.

  Examples of such highly cross-linked polyacrylate fibers include the product name “Breath Thermo” sold by the present applicant, the product name “Moiscare” manufactured by Toyobo Co., Ltd., and the product name “Sunburner” manufactured by Toho Textile Co., Ltd.

  The fluorescent whitening agent is a compound that absorbs light in the ultraviolet region (wavelength 330 to 380 nm) and emits fluorescence of a short wavelength (wavelength 400 to 450 nm) in the visible region, and is a dye having affinity for fibers. . Usually, cationic dyes are used for acrylic fibers (for example, “Encyclopedia of Fibers”, Maruzen, published on March 25, 2002, pages 405 and 499). Anionic optical brighteners are known in fields that differ from the technical field of the present invention. For example, there are proposals to add to paper such as ink jet recording paper, heat sensitive paper, radiographic paper, or resin (Japanese Patent Laid-Open No. 2005-238613, Japanese Patent Laid-Open No. 8-192577, Japanese Patent Laid-Open No. 8-211519, etc.).

  The anionic optical brightener is preferably a compound derived from diaminostilbene disulfonic acid. Examples of this compound include the following formulas (Chemical Formula 1) to (Chemical Formula 3).

  In the above formulas (Chemical Formula 1) to (Chemical Formula 3), R1 to R14 represent a hydrogen atom, an alkyl group, an aryl group, or a heterocyclic group. R1 and R2, R3 and R4, R5 and R6, R7 and R8, R9 and R10, R11 and R12, and R13 and R14 may be the same or different. They may be bonded to each other to form a ring. Therefore, all of R1 to R14 may be the same or different. M represents a hydrogen atom, an alkali metal, or an alkaline earth metal. What is represented by R1 to R14 is preferably an alkyl group other than a hydrogen atom, and is a substituted or unsubstituted alkyl group having 1 to 8 carbon atoms, preferably 1 to 4 carbon atoms, such as a methyl group, an ethyl group, i- Propyl group, n-propyl group, n-octyl group, 2-sulfoethyl group, 2-hydroxyethyl group, 2-hydroxypropyl group, 3-hydroxypropyl group, 2-methoxyethyl group, 2- (2-hydroxyethoxy) Examples thereof include an ethyl group, a 2,3-dihydroxypropyl group, a 3,4-dihydroxybutyl group, a carboxymethyl group, and a 2-carboxyethyl group. The aryl group represented by R1 to R14 is a substituted or unsubstituted aryl group having 6 to 10 carbon atoms, preferably 6 to 8 carbon atoms, such as a phenyl group, a 3-carboxyphenyl group, and a 4-carboxyphenyl group. 3,5-dicarboxyphenyl group, 2-sulfophenyl group, 3-sulfophenyl group, 4-sulfophenyl group, and 2,5-disulfophenyl group. The heterocyclic group represented by R1 to R14 includes one hydrogen atom from a substituted or unsubstituted 5- or 6-membered aromatic or non-aromatic heterocyclic compound having 2 to 10 carbon atoms, preferably 3 to 8 carbon atoms. Is a monovalent group from which 2-furyl group, 2-thienyl and the like are removed. Examples of those in which R1 and R2, R3 and R4, R5 and R6, R7 and R8, R9 and R10, R11 and R12, and R13 and R14 are bonded to each other to form a ring include a morpholyl group. Of the alkali metals and alkaline earth metals represented by M, Na and K are particularly preferred.

  More specifically, there are, for example, the following formulas (Chemical Formula 4) to (Chemical Formula 6), (Chemical Formula 4) is Fluorescent 90, (Chemical Formula 5) is Fluorescent 353, and (Chemical Formula 6) is Fluorescent. Known as 104.

  The following (Chemical Formula 7) to (Chemical Formula 10) can also be exemplified as useful compounds. The following (Chemical 7) is known as Fluorescent 49, the following (Chemical 8) is known as Fluorescent 223, and (Chemical 9) is known as Fluorescent 1. Although (Chemical Formula 10) is not given a fluorescent number, it is known. These compounds may be used alone or in admixture at any ratio. In addition, the anionic styrylbenzene fluorescent whitening agent (fluorescence 11) and fluorescent 351 of (Chemical Formula 11) can be used alone or mixed with the stilbene fluorescent whitening agent in an arbitrary ratio.

  The anionic optical brightener is attached to a highly crosslinked polyacrylate fiber. Here, the adhesion may be adsorption by a dyeing method or fixation using a binder together. Adsorption by a staining method is preferred. Thereby, a texture can be kept favorable and washing resistance can be improved. In the case of the dyeing method, it is immersed in an aqueous dispersion containing an anionic fluorescent whitening agent, treated at 10 to 200 ° C. for 20 seconds to 120 minutes, and adsorbed. Treatment methods include exhaust dyeing, continuous dyeing, and methods using steam.

  The anionic fluorescent whitening agent may be mixed with dyes such as green, blue, and purple for adjusting the color tone. Examples of the color tone adjusting dye (bluing agent) include a disperse dye, an acid dye, a reactive dye, a direct dye, and a basic dye.

  The anionic fluorescent whitening agent is preferably attached to 0.01 to 2% owf, more preferably 0.02 to 1.5% owf with respect to the highly crosslinked polyacrylate fiber. owf stands for on the weight of fiber.

  In the present invention, the original red color of the highly cross-linked polyacrylate fiber is lowered and whitened can be discriminated with the naked eye, but can be objectively determined by measuring the color with a spectroscopic colorimeter. This spectrocolorimeter measures L * value, a * value, and b * value (hereinafter, simply referred to as L value, a value, and b value). This color system was standardized by the CIE (International Lighting Association) in 1976 and adopted in JIS Z 8729 in Japan. Also in the field of fibers, it is commonly used to measure color differences. L * value represents lightness (brightness), a * value and b * value represent hue (hue) and saturation (brightness), + a * value represents red direction, and -a * value represents green direction. The + b * value indicates the yellow direction, and the -b * value indicates the blue direction. In the present invention, the a value is preferably 0.5 or more, more preferably 1 or more, higher than that of an untreated product. The b value is preferably 0.5 or more, more preferably 1 or more. When the a value and the b value are higher than 0.5, it is a level at which a visual difference can be judged.

Next, a test method for the degree of adhesion of the optical brightener used in the present invention will be described. The fluorescent whitening agent can be identified according to JIS L 1064 textile product fluorescent whitening tribe judgment method B method. From this measurement, if at least one of the following features is present, it can be confirmed that the fluorescent whitening agent is used in the present invention.
(1) Within a wavelength of 300-400 nm, the maximum absorption wavelength is within 330-390 nm, preferably within 340-370 nm.
(2) Within the wavelength range of 200 to 350 nm, the lowest absorption wavelength is within the range of 240 to 340 nm, preferably within the range of 250 to 320 nm.
(3) In the case of processed dough, when plotting with the horizontal axis of the wavelength and the vertical axis of absorbance, when plotting the curve differentiated within the wavelength of 220-300nm, one or more points that are convex upward is there.
(4) Preferably, in the absorbance analysis of the liquid obtained by extracting the fluorescent whitening highly crosslinked polyacrylate fiber of the present invention by the following method, there should be one or more points that are convex upward within the wavelength range of 220 to 300 nm. It is.
In accordance with JIS L 1064 textile product fluorescent whitening agent tribal determination method B, use methanol: water = 1: 1 to prepare and extract a sample solution. At this time, without performing concentration and purification operations, 5 g of treated cloth is placed in a 200 ml stainless steel pot, filled with 150 ml of the above extraction solvent, and extracted at 90 to 95 ° C. for 1 hour. Then, it cools, only a liquid is moved to a beaker, It dilutes with ion water, Then, an absorption curve is measured with a photoelectric spectrophotometer.

  The present invention can be applied at any stage of cotton, yarn, and fabric of highly crosslinked polyacrylate fibers. As the fabric, woven fabric, knitted fabric, non-woven fabric, etc. can be adopted. For example, plain weave, oblique weave, satin weave, altered plain weave, altered satin weave, altered satin weave, alter weave, crest weave, single layer weave, double structure, multiple structure, warp pile weft, weft pile weave There are tangles, etc. Examples of knitted fabrics include round knitting, weft knitting, warp knitting (including tricot knitting and Russell knitting), pile knitting, etc. There are denby tissue, cord tissue, atlas tissue, chain tissue, insertion tissue and the like. Other than the fabric, it can be used as stuffed cotton, for example, in a futon or a coat.

  The fluorescent whitening highly crosslinked polyacrylate fiber of the present invention may be mixed with other fibers. In the case of mixing, 2 to 100% by mass of fluorescent whitening highly crosslinked polyacrylate fiber and 0 to 98% by mass of other fibers may be used. Other fibers include polyester, polyolefin, nylon, polypropylene, rayon (manufactured by Lenzing, including "Tencel"), cupra, acetate, ethylene vinyl alcohol (example: Kuraray, "Sofista"), It may be any fiber such as cotton (cotton), hemp, silk, animal fiber represented by wool (wool), general acrylic fiber, and highly crosslinked polyacrylate fiber. Includes stuffing like feathers.

For example, the following method can be used for mixing with other fibers.
(1) Blending: Blending is a blending of two or more fibers at the cotton stage. For example, blending with mixed cotton, card, strips, sliver and the like. Used mainly for uniform mixing of spun yarn, non-woven fabric, and stuffed cotton.
(2) Combined yarn: Combined yarn is a mixture of two or more yarns twisted together. For example, in the case of twin yarn, it is a mixture in which the fiber yarn of the present invention and other fiber yarns are twisted together. Used for twisting spun yarns, spun yarns and filament yarns, and filament yarns.
(3) Mixed fiber: Mixed fiber is used when mixing single fibers of filament yarns.
(4) Interweaving: Interwoven is a mixture when a plurality of types of yarns constituting a woven fabric are used to form a woven fabric. For example, the warp and the weft may be different types, or a plurality of warps and wefts may be used.
(5) Knit: Knit is a mixture when multiple types of yarn are used when manufacturing a knitted fabric.
(6) A plurality of laminated fiber layers are mixed by needle punching and hydroentanglement in the production of a nonwoven fabric.

  The reason why it is preferable to mix with other fibers is to maintain the liquid phase moisture in the other fibers when wetted with a large amount of sweat or rain, and to keep the moisture absorption heat generation of the fibers of the present invention. If it does in this way, although it will be in the wet state as a whole fiber, since the hygroscopic heat_generation | fever of the fiber of this invention continues, a fiber is warm, heat retention is high, and comfort becomes favorable.

  When mixed with the other fibers to form a fiber structure, a cationic fluorescent brightener may be attached to the other fibers. That is, a fiber structure obtained by mixing a fluorescent whitening highly cross-linked polyacrylate fiber to which the anionic fluorescent whitening agent of the present invention is adhered and a fiber other than the highly cross-linked polyacrylate fiber to which a cationic fluorescent whitening agent is adhered. It can also be.

  For example, when using a polyester fiber that has been water-absorbing and quick-drying as other fibers, the moisture absorption heat generation effect of the fiber of the present invention can be obtained because the polyester fiber absorbs and dries liquid water quickly against a large amount of sweat or rain. As a result, evaporative cooling is less likely to occur and the temperature becomes warmer. Furthermore, as a synergistic effect, the heat generation persistence of the fiber of the present invention also promotes the (water absorption) drying property of the polyester fiber itself, resulting in faster drying and better comfort.

  As the fiber structure of the present invention, a yarn, a woven fabric, a knitted fabric, a non-woven fabric or a stuffing is preferable. In the case of stuffing, it may be used by mixing with feathers. Furthermore, as the fiber structure, clothes, hats, ear hooks, mufflers, gloves, socks, sleeping bags, futons, pillows, cushions, blankets, rugs, carpets, and materials related to housing-related floor materials, wall materials, tatami mats, etc. Also mentioned. It is especially suitable for sportswear such as clothing, mountain climbing and skiing in cold weather. Clothing includes underwear, underwear, shirts, jumpers, sweaters, pants, jackets, windbreakers, training wear, rainwear, tights, stomachbands, mufflers, hats, gloves, socks, and ear pads.

The fluorescent whitening highly crosslinked polyacrylate fiber of the present invention and the fiber structure containing the same also have the following advantages.
(1) When used as clothes, the heat builds up and warmth increases.
(2) Since it becomes white, it can provide white clothing suitable for sports and men.
(3) Color developability is improved in other colors than white.
(4) Since the hygroscopic property is improved, the feeling of stuffiness in the clothes is further reduced.
(5) In production, since fiber strength does not decrease, spinnability and dyeability do not decrease, and yield due to color blur is improved.

  Hereinafter, it demonstrates more concretely using an Example. In addition, this invention is limited to a following example and is not interpreted.

(Examples 1-2, Comparative Examples 1-2)
(1) Processing to highly cross-linked polyacrylate fiber (trade name “Breath Thermo”) raw cotton 0.1 kg of the raw cotton is weighed and used as an anionic fluorescent whitening agent, trade name “hakkol BS” ( A compound derived from diaminostilbene disulfonic acid) was collected so as to be 0.5% owf with respect to the raw cotton, and pure water was weighed so that the bath ratio was 1:20. Breath thermo raw cotton was put into a dyeing machine together with the above chemicals, slowly heated from room temperature (18 ° C.) and processed at 80 ° C. for 30 minutes. Then, it dehydrated and put into the ventilation drying machine and dried. This is Example 1.
(2) Processing to fabric containing highly crosslinked polyacrylate fiber (trade name “Breath Thermo”) Obtained from spun yarn blended with 10% by weight of “Breath Thermo” fiber and 90% by weight of polyester (PET) short fiber With respect to a knitted fabric having a basis weight of 150 g / m ² , the above-mentioned fluorescent whitening agent is collected so as to be 0.5% owf with respect to the knitted fabric, and pure water so that the bath ratio is 1:20 with respect to the fabric. Weighed. The dough was placed in a dyeing machine together with the above chemicals, slowly heated from room temperature (18 ° C.) and treated at 130 ° C. for 30 minutes. Then, it dehydrated and put into the ventilation drying machine and dried. This is Example 2.
(3) The raw “breath thermo fiber” raw cotton of Example 1 is referred to as Comparative Example 1.
(4) The raw fabric of Example 2 is referred to as Comparative Example 2.

<Color evaluation>
The color (L value, a value, b value) was measured using a spectroscopic color meter (manufactured by Nippon Denshoku Industries Co., Ltd., product number SE-2000).
<Fever evaluation>
The samples of Examples 1 and 2 and Comparative Examples 1 and 2 were placed in a constant temperature dryer and dried at 120 ° C. for 12 hours. The sample was placed in a desiccator and placed in an environment of 20 ° C., and the temperature was adjusted so that the sample became 20 ° C. The temperature-controlled sample was placed in an environmental test chamber set at 20 ° C. and relative humidity 90% RH, and the change in the sample surface temperature at that time was measured by thermography. The temperature was compared 3 minutes after the start of the test.

<Hygroscopic evaluation>
The samples of Examples 1 and 2 and Comparative Examples 1 and 2 were put in a constant temperature dryer and dried at 120 ° C. for 12 hours. Let A be the weight of the absolutely dried sample. Next, the sample was placed in a constant temperature and humidity chamber to absorb moisture (20 ° C., relative humidity 65% RH, 12 hours). Let B be the weight of the sample after moisture absorption. The moisture absorption rate was calculated from the following equation.
Moisture absorption rate (%) = [(BA) / A] x 100
The above results are summarized in Table 1.

<Strength evaluation>
The fibers of Example 1 and Comparative Example 1 were subjected to JIS L1015 tensile strength test. As a result, the fibers of Example 1 and Comparative Example 1 were both 0.51 cN / dtex, and there was no change in strength. The fabrics of Example 2 and Comparative Example 2 were subjected to a burst strength test of JIS L1018 8.17.1A (Mullen type). As a result, the fabrics of Example 2 and Comparative Example 2 were both 421 kPa, and there was no change in strength.

  From the above results, the fiber of Example 1 and the fabric of Example 2 are lower in red (a value) and yellow (b value) and higher in whiteness than in the comparative example, respectively, and adsorb moisture in the gas phase. It was confirmed that the calorific value was high and the hygroscopicity was also high. There was no change in strength.

  The fiber of Example 1 was prepared and extracted as a sample solution using methanol: water = 1: 1 in accordance with the method B for determining the fluorescent brightener tribe of the JIS L 1064 fiber product. At this time, without performing concentration and purification operations, 5 g of treated cloth was placed in a 200 ml stainless steel pot, filled with 150 ml of the above extraction solvent, and extracted at 90 to 95 ° C. for 1 hour. Thereafter, the mixture was cooled, and only the liquid was transferred to a beaker, diluted with ionic water, and then the absorption curve was measured with a photoelectric spectrophotometer (manufactured by Hitachi, product number U-2800A type spectrophotometer). As a result, as shown in FIG. 1, one or more points (shoulders) that protrude upward within a wavelength range of 220 to 260 nm were recognized. This confirmed the presence of the fluorescent brightening agent.

(Example 3, Comparative Example 3)
In this example, the fabric dyed black was evaluated. A knitted fabric having a basis weight of 150 g / m ² obtained from a spun yarn obtained by blending 10% by mass of “breath thermo” fiber and 90% by mass of polyester (PET) short fiber was used.
Fluorescent whitening agent: 0.5% owf of the brightening agent used in Example 1 with respect to the “breath thermo” raw cotton
Disperse dye: 2.0% owf to fabric
Auxiliary agent (dispersant): 1g / L for fabric
Bath ratio: Pure water was used so that the ratio was 1:20 with respect to the dough. The dough was placed in a dyeing machine together with the above chemicals, slowly heated from room temperature (18 ° C) and treated at 130 ° C for 30 minutes. Then, it dehydrated and put into the ventilation drying machine and dried.

  Comparative Example 3 was stained in the same manner as Example 3 except that no fluorescent brightener was added.

  Table 2 summarizes the results of the fabrics obtained in Example 3 and Comparative Example 3. Note that the dyed product was black, and the difference was not known in the L value, a value, and b value obtained by the spectral colorimeter.

  From the above results, the fabric of Example 3 has a clear color with low red (a value) and yellow (b value) compared to Comparative Example 3, and the calorific value when adsorbing moisture in the gas phase is high. It was also confirmed that the hygroscopicity was high.

Example 4
In this example, the results of a laundry test are shown. The fluorescent whitening treated fabric obtained in Example 2 was washed 10 times according to JIS L 0217 103 method. The color before and after washing was measured with a color meter. The results are shown in Table 3.

  As shown in Table 3, the L value and the a value decreased by 0.1 after washing, but the difference was not found visually. The b value has not changed, and it can be determined that the durability by washing is high.

(Examples 5 to 11 and Comparative Example 4)
In this example and comparative example, the experiment was performed in the same manner as in Example 1 except that the concentration of the fluorescent brightening agent is shown in Table 4, and the colorimetry and the moisture absorption rate were measured. The results are shown in Table 4. However, the highly cross-linked polyacrylate fiber (trade name “Breath Thermo”) used in Examples 1 and 2 and Comparative Examples 1 and 2 is used. did.

The following was found from the results in Table 4.
(1) If the optical brightener is 0.01% owf or more, the a value is lower than that of the comparative product, and redness is reduced.
(2) If the fluorescent whitening agent is 0.02% owf or more, both the a value and the b value are 0.5 or more lower than the comparative example product, and the whitening becomes brighter.
(3) If the optical brightener is 2.0% owf or less, the color becomes slightly blue.
(4) If the fluorescent whitening agent is 1.5% owf or less, there is little bluishness and whiteness stands out.
(5) If the optical brightener is 0.01% owf or more, the hygroscopicity is increased.

The fluorescent whitening highly cross-linked polyacrylate fiber of the present invention has a red color inherent to the highly cross-linked polyacrylate fiber by adhering an anionic fluorescent whitening agent to the highly cross-linked polyacrylate fiber that generates heat by adsorbing moisture in the gas phase. It is characterized by lowering and whitening .

Claims (12)

  1. A fluorescent whitening highly cross-linked polyacrylate fiber, characterized in that an anionic fluorescent whitening agent is attached to a highly cross-linked polyacrylate fiber that generates heat by adsorbing moisture in the gas phase.   The fluorescent whitening highly crosslinked polyacrylate fiber according to claim 1, wherein the anionic fluorescent whitening agent is a compound derived from diaminostilbene disulfonic acid or a styrylbenzene compound.   The fluorescent whitening highly crosslinked polyacrylate fiber according to claim 1 or 2, wherein the anionic fluorescent whitening agent is attached to 0.01 to 2% owf with respect to the highly crosslinked polyacrylate fiber.   The fluorescent whitening highly crosslinked polyacrylate fiber according to any one of claims 1 to 3, wherein the anionic fluorescent whitening agent is adsorbed on the highly crosslinked polyacrylate fiber as a dye.   The fluorescent whitening highly crosslinked polyacrylate fiber according to any one of claims 1 to 4, wherein the fluorescent whitening highly crosslinked polyacrylate fiber is whitened by lowering the original red color of the highly crosslinked polyacrylate fiber.   The fluorescent whitening according to any one of claims 1 to 5, wherein the fluorescent whitening highly crosslinked polyacrylate fiber has a higher moisture adsorption amount and a moisture absorption heat generation amount than a highly crosslinked polyacrylate fiber not subjected to fluorescent whitening. Highly cross-linked polyacrylate fiber.   2. The fluorescent whitening highly crosslinked polyacrylate fiber has one or more points that are convex upward within a wavelength range of 220 to 300 nm in an absorbance analysis of a liquid extracted with water at 90 to 95 ° C. for 60 minutes. The fluorescent whitening highly crosslinked polyacrylate fiber according to any one of -6. It is a manufacturing method of the fluorescent whitening highly crosslinked polyacrylate fiber according to any one of claims 1 to 7,
Highly cross-linked polyacrylate fibers that generate heat by adsorbing moisture in the gas phase are brought into contact with an aqueous dispersion containing an anionic fluorescent whitening agent and treated at 10 to 200 ° C. for 20 seconds to 120 minutes to form fluorescent whitening highly crosslinked poly. A method for producing a fluorescent whitening highly crosslinked polyacrylate fiber, characterized by obtaining an acrylate fiber.   The method for producing a fluorescent whitening highly crosslinked polyacrylate fiber according to claim 8, wherein the production method is an exhaust dyeing method, a continuous dyeing method, or a treatment method using steam.   A fiber structure comprising the fluorescent whitening highly crosslinked polyacrylate fiber according to any one of claims 1 to 7.   The fiber structure is a mixture of a fluorescent whitening highly crosslinked polyacrylate fiber to which an anionic fluorescent whitening agent is attached and a fiber other than a highly crosslinked polyacrylate fiber to which a cationic fluorescent whitening agent is attached. Item 11. A fiber structure according to Item 10.   The fiber constituting the fiber structure has one or more points that protrude upward in a wavelength range of 220 to 300 nm in an absorbance analysis of a liquid extracted with water at 90 to 95 ° C for 60 minutes. 11. The fiber structure according to 11.

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