JP4058678B2 - Material - Google Patents

Description

【００５３】
【発明の効果】
本発明によれば、高白度吸湿性繊維を少なくとも一部に用いた資材としたことで、資材に要求される基本物性並びに吸湿性特性を維持しながら、かかる従来の吸湿性繊維が抱える色が不安定であるという欠点の改良を可能としたものである。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a material made of hygroscopic synthetic fiber. More specifically, color stability that has flame retardancy and antibacterial properties, has excellent processability, improves whiteness more than conventional products, and does not change color even after repeated exposure and washing in the dyeing process. The present invention relates to a material composed of a high whiteness hygroscopic synthetic fiber excellent in properties, in particular, a sheet, a futon side fabric, a lace curtain, a seat cover, a patch, a wallpaper, a shoe side fabric, an interlining, a towel, a puff, and a low-density fabric.
[0002]
[Prior art]
Natural fibers typified by cotton are preferred because of their texture and comfort. The main factor of this comfortable wearing feeling is that the natural fiber has an appropriate hygroscopicity. Due to such excellent characteristics, its use has spread to various fields as a living material represented by bedding. However, in order to maintain the whiteness against yellowing due to repeated exposure and washing, it is necessary to perform bleaching washing, which causes problems such as fiber deterioration and rough skin due to residual bleach. I have it.
[0003]
In addition, wool products are not only difficult to obtain the high whiteness required for materials, but also have the problem that the whiteness decreases with repeated washing, as is the case with cotton. Absent.
[0004]
On the other hand, synthetic fibers, especially low-cost polyester, are widely used for various material applications with excellent durability, but due to low hygroscopicity, discomfort due to stuffiness is noticeable when used in applications that touch the skin, The improvement is desired. In addition, humidity control functions have been demanded for applications that do not touch the skin, such as curtains and wallpaper, and the official moisture content of nylon, which is relatively excellent in hygroscopicity among synthetic fibers, is about 4-5%, and is still The feeling of stuffiness has not been eliminated.
[0005]
Various studies have been made to improve the hygroscopicity of fibers. As a means for removing moisture in the air from the fibrous material, a means of Japanese Patent Application Laid-Open No. 1-299624 in which a highly water-absorbing fiber is impregnated with a deliquescent salt has been proposed. The fibers obtained by this means are easy to process into knitted fabrics, woven fabrics, non-woven fabrics, etc., have a high moisture absorption / release rate, and have practical performance with no hygroscopic removal, but the fiber surface is hydrogel. For this reason, when it absorbs moisture, it becomes sticky, and in particular, it is difficult to apply to wallpaper and futon, and it does not satisfy the flame retardancy and antibacterial properties that are increasing as social needs recently.
[0006]
As a method for solving these problems, means disclosed in Japanese Patent Laid-Open No. 5-132858 has been proposed. However, in this method, if the amount of the salt-type carboxyl group exceeds 4.5 meq / g, the tensile strength becomes 0.9 cN / dtex or less, and the fiber properties are insufficient to withstand various processing. It was a barrier to further increase the moisture absorption rate. In addition, when the increase in nitrogen content introduced by the treatment with the hydrazine compound in order to obtain a highly hygroscopic fiber having a fiber strength of 0.9 cN / dtex or more exceeds 8.0% by weight, There was a problem that the amount of salt-type carboxyl group introduced was reduced and the hygroscopicity was lowered.
[0007]
Further, the fiber obtained by the method according to JP-A-5-132858 has a disadvantage that the field of use is limited because it exhibits a dark brown color to a dark brown color. The invention of Japanese Patent Laid-Open No. 9-158040, which has been proposed as a means for overcoming this drawback, is that the acid treatment A is performed after the crosslinking treatment with a hydrazine compound, and the acid treatment B is performed after the hydrolysis treatment with an alkali. Thus, whiteness can be improved considerably. However, even with such technology, the present situation is that it does not sufficiently satisfy a field that requires strict whiteness. Japanese Patent Application Laid-Open No. 2000-303353 discloses performing a hydrolysis treatment in an oxygen-free atmosphere as a method for improving whiteness. However, since the fiber obtained by this method is colored by repeated oxidative bleaching and washing in the dyeing process, it has the disadvantage of poor color stability.
[0008]
[Problems to be solved by the invention]
The present invention at least partially includes a fiber that has improved the disadvantage that the color of such a conventional hygroscopic fiber is unstable while maintaining the basic physical properties required for the fiber and the characteristics that the hygroscopic fiber should have. The purpose is to provide the materials used.
[0009]
[Means for Solving the Problems]
That is, this invention consists of the following structures.
1. In the display method described in JIS-Z-8729, the saturated moisture absorption at 20 ° C. and 65% RH is 10% by weight or more, and the whiteness is in the range of L * 85 or more, a * ± 6, and JIS-L0217- In the display method according to JIS-Z-8729 , the high whiteness hygroscopic synthetic fiber having a whiteness of the fibers after washing of 5 times after the washing process of 103 method is within the range of L * 85 and a * ± 6. possess at least a portion, Koshirodo hygroscopic synthetic fibers, acrylic fibers made of an acrylonitrile-based polymer is a copolymerization component (meth) acrylic acid ester compound is less than 5 wt%, cross-linking by a hydrazine compound introducing treatment, hydrolysis, materials, characterized in der Rukoto that has been subjected to reduction treatment.
2. 2. The material according to the first item, wherein the saturated water absorption of the high whiteness hygroscopic synthetic fiber is 300% by weight or less.
3 . The material according to the above 1 or 2, wherein the discoloration of the high whiteness hygroscopic synthetic fiber after washing 5 times is 3-4 grade or more as evaluated by a gray scale for JIS-L0805 contamination.
4). The first to third aspects, wherein the material is one of a sheet, a futon side, a lace curtain, a seat cover, a patch, a wallpaper, a shoe side, an interlining, a towel, a puff, or a low-density fabric. Materials listed in any one.
[0010]
The present invention is described in detail below.
The hygroscopic fiber employed in at least a part of the material of the present invention preferably has a saturated moisture absorption rate of 10% by weight or more at 20 ° C. and 65% RH. Further, the whiteness of the high whiteness hygroscopic fiber of the present invention is preferably in the range of L * 85 or more and a * ± 6 in the display method described in JIS-Z-8729. More preferably, L * is 86 or more and a * is in the range of ± 4.
[0011]
In addition, the high whiteness hygroscopic fiber employed in at least a part of the material of the present invention is characterized in that the discoloration of the whiteness is extremely small even in the washing process, that is, the point is excellent in washing durability. Specifically, in the display method described in JIS-Z-8729, the whiteness of the fiber after 5 washes washed by the JIS-L0217-103 method (detergent uses an attack made by Kao Corporation) is L * 85. As described above, it is preferable that L * is within a range of a * ± 6, preferably L * is 86 or more, and a * is within a range of ± 5. Moreover, it is preferable that the discoloration after 5 times of washing is a thing of 3-4 grade or more evaluated by the gray scale for JIS-L0805 contamination. In addition, even after washing treatment, the thing most loosened in apparel use is redness. From this, the difference (Δa *) between before and after washing of the value of a * that is a parameter representing redness It is preferably 0.7 or less, and more preferably 0.6 or less. In addition, the washing durability of the material of this invention was measured based on JIS-L0844-B method.
[0012]
The saturated water absorption of the high whiteness hygroscopic fibers employed in at least a part of the material of the present invention is preferably 300% by weight or less. When the saturated water absorption exceeds 300% by weight, the fiber surface is sticky when water is absorbed, which is not particularly preferable for use on a futon side.
[0013]
In addition, it is desirable that the high whiteness hygroscopic fiber used in at least a part of the material does not decrease in whiteness even in the treatment such as oxidative exposure in the dyeing process. Specifically, the hydrogen peroxide concentration is 0 .5% by weight, NaOH pH = 10, bath ratio 1/50, 80 ° C., and 60% exposure to hydrogen peroxide fiber discoloration after bleaching (exposure durability) evaluated on JIS-L0805 contamination gray scale Grade 3 or higher, and the discoloration (standing stability) after leaving the fiber in the presence of water exceeding the saturated water absorption at 80 ° C. for 16 hours is grade 3-4 or higher as evaluated on a JIS-L0805 contamination gray scale. It is preferable.
[0014]
Here, the value (class) of exposure durability is set so that the fiber ratio of the fiber sample to the aqueous solution is 1/50 in an aqueous solution of 0.5% by weight of hydrogen peroxide adjusted to pH 10 with NaOH. In addition, it was obtained by evaluating the degree of discoloration from the color of the fiber sample before the bleaching treatment of the fiber which had been bleached at 80 ° C. for 60 minutes using a gray scale for JIS-L0805 contamination.
[0015]
In addition, the standing stability value (class) was obtained by immersing the sample fiber in pure water and allowing it to be sufficiently water-containing, and taking out the sample fiber, and holding a sufficient amount of water to maintain water exceeding the saturated water absorption even at 80 ° C. As it is, seal the container so that more than half of the container is a space, put it in a thermostat adjusted to 80 ° C., and remove the dehydrated and dried fiber after 16 hours. Degree of discoloration from the fiber sample before processing It was obtained by evaluating with a gray scale for JIS-L0805 contamination.
The saturated water absorption is an amount obtained by subtracting the weight after drying (105 ° C. × 16 hours) of the same sample fiber from the weight after centrifugal dehydration (160 G × 5 minutes) of the sufficiently water-containing fiber. Further, the saturated water absorption is a value obtained by dividing the saturated water absorption by the weight after drying (105 ° C. × 16 hours) of the sample fiber in%.
[0016]
As a method for producing such a high whiteness hygroscopic fiber employed in at least a part of the material of the present invention, an acrylic resin comprising an acrylonitrile polymer having a (meth) acrylic acid ester compound of less than 5% by weight as a copolymerization component is used. A method for producing a high whiteness hygroscopic fiber is recommended, which is characterized by subjecting the base fiber to a cross-linking introduction treatment with a hydrazine-based compound, hydrolysis, and reduction treatment. The method will be described in detail below.
[0017]
The starting acrylic fiber (hereinafter also referred to as acrylonitrile fiber) is a fiber formed of an AN polymer containing acrylonitrile (hereinafter referred to as AN) of 40% by weight or more, preferably 50% by weight or more. , Short fibers, tows, yarns, knitted fabrics, non-woven fabrics, and the like, and may be intermediate products in the manufacturing process, waste fibers, and the like. The AN polymer may be either an AN homopolymer or a copolymer of AN and another monomer, but a (meth) acrylic acid ester compound is most preferably used as a monomer copolymerizable with AN. However, when it is unavoidable, it needs to be less than 5% by weight, more preferably 4.0% by weight or less. In addition, the description which attached | subjected (meth) represents both acrylic acid ester and methacrylic acid ester. Examples of the ester compound that may be used as a copolymer component as long as it is less than 5% by weight include, for example, methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, and (meth) acrylic acid. Examples include dimethylaminoethyl, diethylaminoethyl (meth) acrylate, and the like. Other copolymer components include sulfonic acid group-containing monomers such as methallyl sulfonic acid and p-styrene sulfonic acid and their salts; monomers such as styrene and vinyl acetate that can be copolymerized with AN Although it will not specifically limit if it is a body, It is desirable to copolymerize 5-20 weight% of vinyl ester type compounds represented by vinyl acetate. Such vinyl esters include vinyl acetate, vinyl propionate, vinyl butyrate and the like.
[0018]
The acrylic fiber is subjected to a cross-linking introduction treatment with a hydrazine compound, and a cross-link is formed in the sense that it is no longer dissolved in the solvent of the acrylic fiber, and at the same time, an increase in nitrogen content occurs. The means is not particularly limited. A means by which the increase in nitrogen content by this treatment can be adjusted to 1.0 to 10% by weight is preferable, but even if the increase in nitrogen content is 0.1 to 1.0% by weight, Any high-whiteness hygroscopic fiber that can be used at least in part can be used. In addition, as a means by which the increase in nitrogen content can be adjusted to 1.0 to 10% by weight, a means for treating within 5 hours at a temperature of 50 to 120 ° C. in an aqueous solution of a hydrazine compound concentration of 5 to 60% by weight. Is industrially preferred. In order to keep the increase in nitrogen content at a low rate, these conditions should be made milder in accordance with the teaching of reaction engineering. Here, the increase in the nitrogen content refers to the difference between the nitrogen content of the raw acrylic fiber and the nitrogen content of the acrylic fiber into which crosslinking by the hydrazine compound has been introduced.
[0019]
The hydrazine-based compound used here is not particularly limited, and hydrazine hydrate, hydrazine sulfate, hydrazine hydrochloride, hydrazine bromate, hydrazine carbonate, etc., other ethylenediamine, guanidine sulfate, guanidine hydrochloride, guanidine phosphate, Examples include compounds containing a plurality of amino groups such as melamine.
[0020]
The fiber that has undergone the crosslinking and introducing treatment step with such a hydrazine-based compound may be subjected to an acid treatment. This treatment contributes to the improvement of the color stability of the fiber. Examples of the acid used here include, but are not particularly limited to, aqueous solutions of mineral acids such as nitric acid, sulfuric acid, and hydrochloric acid, and organic acids. Prior to this treatment, the hydrazine-based compound remaining in the crosslinking introduction treatment is sufficiently removed. The conditions for the acid treatment are not particularly limited, but the treated fibers are usually immersed in an aqueous solution having an acid concentration of 5 to 20% by weight, preferably 7 to 15% by weight, at a temperature of 50 to 120 ° C. for 0.5 to 10 hours. An example is given.
[0021]
The fiber that has undergone the cross-linking and introducing treatment step with the hydrazine-based compound, or the fiber that has undergone further acid treatment, is subsequently hydrolyzed with an aqueous alkaline metal salt solution. By this treatment, the remaining CN groups without participating in the cross-linking introduction treatment by the hydrazine-based compound treatment of acrylic fibers, and some remaining CN groups when acid treatment is performed after the cross-linking treatment step The hydrolysis of the CONH ₂ group hydrolyzed by the acid treatment proceeds. These groups form a carboxyl group by hydrolysis, but since the drug used is an alkaline metal salt, a metal salt type carboxyl group is eventually formed. Examples of the alkaline metal salt used here include alkali metal hydroxides, alkaline earth metal hydroxides, and alkali metal carbonates. The concentration of the alkali metal salt to be used is not particularly limited, but the means for treating within 1 to 10 hours at a temperature of 50 to 120 degrees in an aqueous solution of 1 to 10% by weight, more preferably 1 to 5% by weight is industrial, fiber. It is also preferable in terms of physical properties.
[0022]
Examples of the type of metal salt, that is, the salt type of the carboxyl group, include alkali metals such as Li, Na, and K, and alkaline earth metals such as Mg, Ca, and Ba. The degree of hydrolysis, that is, the amount of metal salt-type carboxyl groups should be controlled to 4-10 meq / g, which can be easily done by combining the chemical concentration, temperature, and treatment time during the treatment described above. Can do. In addition, as for the fiber which passed through this hydrolysis process, CN group may or may not remain. If the CN group remains, the reactivity may be utilized to provide further functions.
[0023]
The reducing agent used in the subsequent reduction treatment is one or two selected from the group consisting of hydrosulfite salt, thiosulfate, sulfite, nitrite, thiourea dioxide, ascorbate, and hydrazine compounds. A combination of more than one type can be suitably used. The conditions for the reduction treatment are not particularly limited, but examples include immersing the treated fiber in an aqueous solution having a drug concentration of 0.5 to 5% by weight at a temperature of 50 ° C. to 120 ° C. for 30 minutes to 5 hours. . The reduction treatment may be performed simultaneously with the hydrolysis described above or after the hydrolysis.
[0024]
Thus, a high whiteness hygroscopic fiber employed in at least a part of the material of the present invention can be obtained, but in order to further stabilize the color, the fiber subjected to the above-mentioned reduction treatment step is subjected to an acid treatment, and the metal salt. The H-type carboxyl group is converted to H-type, and a part of the H-type carboxyl group is converted into a metal salt form (salt type adjustment treatment) by metal salt treatment selected from Li, Na, K, Ca, Mg, Ba, and Al. It is preferable to adjust the molar ratio of H type / metal salt type to 90/10 to 0/100.
[0025]
Examples of the acid used for the acid treatment include aqueous solutions of mineral acids such as nitric acid, sulfuric acid and hydrochloric acid, and organic acids, but are not particularly limited. The conditions for the acid treatment are not particularly limited, but the treated fibers are usually immersed in an aqueous solution having an acid concentration of 1 to 10% by weight, preferably 2 to 10% by weight, at a temperature of 50 to 120 ° C. for 2 to 10 hours. An example is given.
[0026]
Further, the metal type of the metal salt employed in the salt type adjustment treatment is selected from Li, Na, K, Ca, Mg, Ba, and Al, but Na, K, Ca, Mg, and the like are particularly recommended. The salt may be a water-soluble salt of these metals, and examples thereof include hydroxides, halides, nitrates, sulfates and carbonates. Specifically, as typical metals, NaOH, Na ₂ CO ₃ as Na salt, KOH as K salt, Ca (OH) ₂ , Ca (NO ₃ ) ₂ , CaCl as Ca salt ₂ is preferred.
[0027]
The H-type / metal salt type molar ratio of the carboxyl group is within the above-described range, but is appropriately set together with the type of metal depending on the function to be given to the fiber. In the concrete implementation of the salt mold adjustment treatment, an aqueous solution of 0.2 to 30% by weight of a metal salt is prepared in a treatment tank, and the treated fiber is immersed at about 20 to 80 ° C. for about 0.25 to 5 hours. Alternatively, there is a method of spraying the aqueous solution. In order to control to the above-mentioned ratio, the salt type adjustment treatment in the presence of a buffering agent is preferable. A buffer having a pH buffering range of 5.0 to 9.2 is suitable. The type of metal salt of the metal salt type carboxyl group is not limited to one type, and two or more types may be mixed.
[0028]
The high whiteness hygroscopic fibers employed in at least a part of the materials of the present invention described above have hygroscopicity, flame retardancy, and antibacterial properties, and are excellent in processability and have whiteness even higher than conventional products. Hygroscopic fiber with improved color stability.
[0029]
Further, when the salt type adjustment treatment is performed with a substance having low water solubility such as a metal salt compound such as Ca, Mg, Ba, etc., the molar ratio of H type / metal salt type to H type carboxyl group in the step is changed to metal There is some difficulty in increasing the salt form. In such a case, as a pretreatment of the salt type adjustment treatment after the acid treatment, the carboxyl group that has been converted to H-type in the acid treatment step is adjusted, that is, the pH indicated by the carboxyl group is adjusted with an aqueous solution such as caustic soda or caustic potash. It is recommended to perform a sum treatment (pH = 5 to 11). By this prescription, since the carboxyl group after neutralization treatment is in a state where H type and Na or K type coexist, the next salt type adjustment treatment is easily performed by exchanging Ca or the like with Na or K. As it progresses, the difficulties raised are resolved.
[0030]
In addition, the manufacturing means of the acrylic fiber which is a starting material is not specifically limited, The means employ | adopted for manufacture of the fiber for normal clothing can be used. In addition, it is preferable to use such a fiber as a starting fiber, but it is not always necessary to complete the final process, even if it is in the middle of the acrylic fiber manufacturing process, or the final fiber is subjected to a spinning process or the like. Later ones are also acceptable. Above all, as the starting acrylic fiber, the fiber before stretching after the acrylic fiber manufacturing process (prior to spinning the AN polymer spinning stock solution according to a conventional method, stretched and oriented, dry densification, wet heat relaxation treatment, etc. When fibers not subjected to heat treatment, especially wet or dry / wet spinning, stretched water-swelled gel fibers: water swelling degree 30 to 150%), the dispersibility of the fibers in the treatment liquid, into the fibers This is desirable because the permeability of the treatment liquid is improved, and the introduction of a crosslink and the hydrolysis reaction are performed uniformly and rapidly.
[0031]
Note that these starting acrylic fibers are filled in a container having a stirring function and a temperature control function, and the above steps are performed sequentially, or a plurality of containers are arranged side by side and continuously taken. However, it is desirable from the viewpoints of the device, such as safety and uniform processability. An example of such an apparatus is a dyeing machine.
[0032]
As another method for producing the high whiteness hygroscopic fiber employed in at least a part of the material of the present invention, the acrylic fiber is subjected to crosslinking introduction treatment, hydrolysis, reduction treatment, acid treatment with the hydrazine compound described above. The method of giving a process and repeating a reduction process and an acid process further is mentioned. Repeating reduction treatment and acid treatment improves whiteness and color stability, is in the range of L * 85 or higher, a * ± 6, and has high whiteness moisture absorption of 3-4 grade or higher. Fiber is obtained. According to this method, even if the (meth) acrylic acid ester compound is 5% by weight or more as a copolymerization component of the acrylonitrile-based polymer forming the acrylic fiber, it is used in at least a part of the material of the present invention. Although whiteness hygroscopic fibers can be obtained, since it is necessary to repeat reduction treatment and acid treatment, the physical properties of the fibers are lowered and the production cost is increased. Therefore, the present invention described above is recommended. It is advantageous to employ a manufacturing method.
[0033]
The fiber employed in at least a part of the material of the present invention is a high whiteness hygroscopic fiber having a high elongation enough to withstand fiber processing and excellent in color stability, and also generates heat with moisture absorption. It also has flame retardancy, antibacterial properties, deodorization properties, chemical resistance, etc. that are thought to be due to a nitrogen-containing crosslinked structure and a high moisture absorption rate.
[0034]
The material of this invention should just contain the above high whiteness hygroscopic synthetic fiber at least in part. It is also preferred to be used in combination with other fibers as necessary. It can be mixed with other staple fibers and filament fibers by methods such as blending, fine spinning and twisting, core yarn, uniform blended composite spinning, twisting, blending, knit, and weaving. However, when mixed with hydrophobic fibers such as polyester fibers, if the content of the high whiteness hygroscopic synthetic fiber is too small, the hygroscopicity becomes poor, so at least 5% by weight, more preferably 10% by weight or more. It is preferable to keep it. The material of the present invention may be a nonwoven fabric. Of course, the high whiteness hygroscopic synthetic fiber may be spun, knitted or woven, or a non-woven fabric.
[0035]
The material of the present invention uses the high whiteness hygroscopic synthetic fiber at least in part, and can be suitably used for all materials having white as a necessary color. Sheets, futon sides, lace curtains, sheets It is suitably used for covers, patch materials, wallpaper, shoe side fabrics, interlinings, towels, puffs, low density fabrics and the like.
[0036]
The reason why the high whiteness hygroscopic fibers employed in at least a part of the material of the present invention described in detail above has excellent whiteness and color stability has not been fully elucidated, but is generally as follows. Conceivable. That is, when a crosslinked structure is introduced with a hydrazine compound, if the acrylic fiber as a raw material contains 5% by weight or more of a (meth) acrylate compound as a copolymer component, the carbonyl carbon portion of the copolymer component As a result, a bond containing an oxygen molecule is introduced into the cross-linked structure due to the reaction of the hydrazine compound with the hydrazine compound, so that color development is likely to occur, that is, the color stability is inferior. It is presumed that the color development is suppressed because it is suppressed at the raw material stage, and it is difficult to develop the color even by treatment such as hydrogen peroxide exposure treatment or repeated washing. In addition, even when the (meth) acrylic acid ester compound is contained in an amount of 5% by weight or more, by repeating the reduction treatment and the acid treatment, a molecular structure that develops a color even by treatment such as hydrogen peroxide exposure treatment and repeated washing This is presumably because it has a stable molecular structure that is difficult to change.
[0037]
【Example】
The present invention will be specifically described below with reference to examples. Parts and percentages in the examples are on a weight basis unless otherwise indicated. The amount of metal salt-type carboxyl group, whiteness and moisture absorption were determined by the following methods.
[0038]
(1) Amount of metal salt type carboxyl group (meq / g)
About 1 g of the sufficiently dried fiber after hydrolysis was precisely weighed (Xg), 200 ml of water was added thereto, 1 mol / l aqueous hydrochloric acid solution was added to pH 2 while heating to 50 ° C., and then 0. A titration curve was obtained with a 1 mol / l aqueous sodium hydroxide solution according to a conventional method. From the titration curve, the consumption amount of the aqueous sodium hydroxide solution (Yml) consumed by the carboxyl groups was determined, and the carboxyl group amount (meq / g) was calculated by the following formula.
(Amount of carboxyl group) = 0.1 Y / X
Separately, a titration curve was similarly obtained without adjusting to pH 2 by adding a 1 mol / l hydrochloric acid aqueous solution during the above-described carboxyl group content measurement operation, and the amount of H-type carboxyl groups (meq / g) was determined. From these results, the metal salt type carboxyl group amount was calculated by the following formula.
(Amount of metal salt type carboxyl group) = (Amount of carboxyl group) − (Amount of H type carboxyl group)
[0039]
(2) 4.0 g of sample fiber defibrated by a whiteness card machine is filled in a rotary colorimetric cell (35 ml transparent cylindrical cell), and color difference meter TC-1500MC-88 manufactured by Tokyo Denshoku Co., Ltd. (D65 light source) ) And colorimetric while rotating at a rate of 60 times / minute. This measurement was repeated 3 times, and L * and a * values (average values) were determined.
(3) Moisture absorption rate (%)
About 5.0 g of sample fiber is dried with a hot air dryer at 105 ° C. for 16 hours, and the weight is measured (W1 g). Next, the sample is placed in a 65% RH constant humidity bath at a temperature of 20 ° C. for 24 hours. The weight of the sample thus absorbed is measured (W2g). From the above measurement results, calculation was performed according to the following equation.
(Hygroscopic rate%) = {(W2-W1) / W1} × 100
(4) Fabric whiteness Whiteness is measured using a spectrocolorimeter CM-3700d manufactured by Minolta Co., Ltd. based on ASTM E313.
JIS whiteness (W) = L * + 3 × a * -3 × b *
(5) Fabric moisture absorption According to the above-described fiber moisture absorption measurement.
[0040]
Example 1
90 parts of a 48% rhodium soda solution of 10 parts of AN polymer (intrinsic viscosity [η]: 1.2) in dimethylformamide at 30 ° C.) consisting of 96% by weight of AN and 4% by weight of methyl acrylate (hereinafter referred to as MA) After spinning and drawing (total draw ratio: 10 times) according to a conventional method, the spinning stock solution dissolved in 1 was dried and wet heat-treated in an atmosphere of dry bulb / wet bulb = 120 ° C./60° C. to obtain a single fiber fineness of 1. A raw material fiber of 7 dtex was obtained.
[0041]
The raw fiber was subjected to 98 ° C. × 5 Hr crosslinking introduction treatment in a 20 wt% aqueous solution of hydrazine hydrate. This treatment introduces cross-linking and increases the nitrogen content. The amount of increase in nitrogen was calculated from the difference between the raw material fiber and the fiber after the cross-linking introduction treatment by obtaining the nitrogen content by elemental analysis. Next, it was hydrolyzed at 90 ° C. × 2 Hr in a 3 wt% aqueous solution of caustic soda and washed with pure water. By this treatment, 5.5 meq / g of Na-type carboxyl group was generated in the fiber.
[0042]
The hydrolyzed fiber was subjected to a reduction treatment at 90 ° C. × 2 Hr in a 1 wt% aqueous solution of hydrosulfite sodium salt (hereinafter referred to as SHS) and washed with pure water.
Subsequently, a 90 ° C. × 2 Hr acid treatment was performed in a 3% by weight aqueous solution of nitric acid. As a result, the total amount of Na-type carboxyl groups produced at 5.5 meq / g was H-type carboxyl groups. The fiber after the acid treatment is put into pure water, and an aqueous caustic soda solution having a concentration of 48% is added so that the neutralization degree of Na is 70 mol% with respect to the H-type carboxyl group, thereby adjusting the salt type at 60 ° C. × 3Hr. Processed.
[0043]
The fiber after the above steps was washed with water, applied with an oil agent, dehydrated and dried to obtain a high whiteness hygroscopic fiber (2 dtex × 38 mm) of Example 1. The resulting fibers were examined for moisture absorption, whiteness, and color stability, and are shown in Table 1 together with the amount of salt-type carboxyl groups and the amount of increased nitrogen. The obtained fiber and polyester staple (1.5 dtex × 38 mm) 3: 7 40/1 blend yarn was made into a plain weave, boiled, and subjected to dry heat setting. The fabric whiteness was 64.3 and the hygroscopicity was 8.0%. The color change after washing was grade 5. When a sheet and a futon side fabric were prepared using the obtained fabric, the fabric was comfortable without stuffiness and there was almost no change in color even after repeated washing.
[0044]
Comparative Example 1
A fabric was prepared according to Example 1 using hygroscopic fibers obtained in the same manner as in Example 1 except that an AN polymer comprising 90% by weight of AN and 10% by weight of MA was used. The fabric whiteness was 60.2 and the hygroscopicity was 7.8%. The color change after washing was grade 3.
[0045]
Example 2
Except for preparing white lacey fiber (1dtex × 28mm) by adjusting the salt mold with caustic potash, mixing with polyester staple (1.5dtex × 48mm) at a ratio of 2: 8, and creating a lace. In the same manner as in Example 1, a fabric was obtained. The fabric whiteness was 68.7, and the hygroscopicity was 5.5%. When a curtain and a seat cover were prepared using the obtained fabric, the fabric had an appropriate hygroscopic property and there was almost no change in color even after repeated washing.
[0046]
Example 3
The fiber of Example 1 was treated with an aqueous solution of calcium chloride to obtain a high whiteness hygroscopic fiber (1 dtex × 44 mm) with a Na-type carboxyl group as a Ca-type carboxyl group, and a polyester staple (1.5 dtex × 1.5 mm) at a ratio of 5: 5. 48 mm), and a fabric was obtained in the same manner as in Example 1 except that a low-density fabric having a basis weight of 40 g / m 2 was prepared. The fabric whiteness was 55.7 and the hygroscopicity was 14.7%. Using the resulting fabric to create an interlining and using it as a white fabric cutter shirt, it is comfortable even when sweated, and there is almost no change in color even after repeated washing, and the interlining is transparent I didn't see it.
[0047]
Comparative Example 2
The same procedure as in Example 1 was conducted except that an AN polymer composed of 94% by weight of AN and 6% by weight of MA was used, and the acid treatment after the reduction treatment and the salt type adjustment treatment were not performed. The fabric whiteness was 60.3 and the hygroscopicity was 7.5%. The color change after washing was grade 2.
[0048]
Example 4
A high whiteness hygroscopic fiber obtained in Example 1 and cotton were blended at 3: 7 to prepare a pile fabric, which was subjected to an exposure treatment using hydrogen peroxide. The fabric whiteness was 69.5 and the hygroscopicity was 14.7%. When a towel was made using the obtained fabric, there was almost no change in color even after repeated washing.
[0049]
Example 5
A plain knitting was made from the blended yarn obtained in Example 4, and a deck shoe was made using it as a shoe side fabric. It was comfortable even when sweating, and there was almost no change in color even after repeated washing.
[0050]
Example 6
A non-woven fabric is a mixture of the high whiteness hygroscopic fibers (3 dtex × 51 mm) obtained in Example 1, polyethylene terephthalate cotton (1 dtex × 60 mm) and polypropylene cotton (1.5 dtex × 46 mm) in a 3: 5: 2 mixture. A patch was prepared. The fabric whiteness was 62.6 and the hygroscopicity was 9.6%. A non-woven type white wallpaper was created that had no problem white, moderate hygroscopicity, and did not cause rough skin. It had no problem whiteness and humidity control.
[0051]
The high whiteness hygroscopic fiber of Example 1 showed a moisture absorption rate of 35%, and the whiteness was also good at L * 88.4 and a * 0.99. Further, the fibers were excellent in color stability in terms of exposure durability, washing durability, and standing stability, respectively, as grades 3-4, 4-5, and 4-5. Examples 2 and 3, which are different from Example 1 in the type of metal salt, had slightly lower moisture absorption than Example 1, but had whiteness and color stability comparable to Example 1 fiber. .
On the other hand, the comparative example 1 used the raw material fiber which contains 10 weight% of MA which is an acrylic ester compound. Whiteness was good, but exposure durability, washing durability, and storage stability were inferior in color stability to grades 2, 3, and 3, respectively, and became problematic in the processing stage or use stage as a final product. It was a level. In Comparative Example 2, since the reduction treatment was omitted, it was colored red.
As described above, according to the present invention, hygroscopic fibers obtained by the technique of Japanese Patent Application Laid-Open No. 2000-303353 have been balanced with hygroscopic performance and whiteness. Compared to the above, it shows a marked improvement.
[0052]
[Table 1]

[0053]
【The invention's effect】
According to the present invention, the high whiteness hygroscopic fiber is used as a material at least in part, so that the color possessed by the conventional hygroscopic fiber is maintained while maintaining the basic physical properties and hygroscopic properties required for the material. This makes it possible to improve the disadvantage of being unstable.

Claims (4)

In the display method described in JIS-Z-8729, the saturated moisture absorption at 20 ° C. and 65% RH is 10% by weight or more, and the whiteness is in the range of L * 85 or more, a * ± 6, and JIS-L0217- whiteness of fibers after washing the treated washing 5 times with 103 method in the display method according to JIS-Z-8729, L * 85 or more, the Koshirodo hygroscopic synthetic fibers is in the range of a * ± 6 possess at least a portion, Koshirodo hygroscopic synthetic fibers, acrylic fibers made of an acrylonitrile-based polymer is a copolymerization component (meth) acrylic acid ester compound is less than 5 wt%, cross-linking by a hydrazine compound introducing treatment, hydrolysis, materials, characterized in der Rukoto that has been subjected to reduction treatment.   The material according to claim 1, wherein the saturated water absorption of the high whiteness hygroscopic synthetic fiber is 300% by weight or less. The material according to claim 1 or 2 , wherein the discoloration of the high whiteness hygroscopic synthetic fiber after washing 5 times is 3-4 or higher as evaluated by a gray scale for JIS-L0805 contamination. The material according to any one of claims 1 to 3, wherein the material is one of a sheet, a futon side, a lace curtain, a seat cover, a patch, a wallpaper, a shoe side, an interlining, a towel, a puff, or a low-density fabric. Materials listed in any one.