JP6008240B2 - Functional acrylonitrile fiber, fiber structure containing the fiber, and method for producing the same - Google Patents

Description

The present invention relates to a functional acrylonitrile fiber and a method for producing the same.

It has been conventionally practiced to add a photocatalyst such as titanium oxide to an acrylonitrile fiber to impart functions such as deodorization, antifouling, antibacterial and antifungal. However, there is a problem that the fiber itself deteriorates due to the photocatalytic action.

Regarding this problem, Patent Document 1 discloses that an acrylonitrile polymer containing 0.5 to 10% by weight of a photocatalyst as a sheath and an acrylonitrile polymer containing 0.1 to 10% by weight of an antioxidant is a core. The technique regarding the deodorant acrylic fiber characterized by having the sheath core structure made into a part and the ratio of the polymer of the sheath part being 1 to 50% by weight is disclosed. Such technology attempts to suppress degradation of physical properties of the entire fiber by localizing the photocatalyst and limiting the range affected by the photocatalytic action. However, the photocatalytic action is exerted on the fiber surface. It will be limited to only.

Regarding the effective use of the photocatalytic function, for example, Patent Document 2 discloses a technique of containing a photocatalyst in a porous fiber. According to this technology, the surface area of the fiber increases and the metal oxide present in the surface layer increases, so it seems that the photocatalytic function can be used effectively, but spinning processability (electrostatic generation), dyeability (color development) There is a problem that the metal oxide fine particles in the surface layer part easily fall off in a process such as spinning and dyeing or washing.

Patent Document 3 discloses a functional fiber characterized in that it is a multilayer structure fiber in which a porous layer and a dense layer are alternately arranged, and metal oxide fine particles having photocatalytic activity are contained in the dense layer. Techniques related to this are disclosed. Such technology suppresses dropping of the photocatalyst from the fiber by containing a photocatalyst on the dense layer side, adsorbs malodorous components and bacteria on the adjacent porous layer, and decomposes it by the photocatalytic action of the dense layer. Is. Although this technology achieves both suppression of photocatalyst dropout and improvement in utilization efficiency, the manufacturing process is also complicated because it has a multilayer structure, one is a porous layer and the other is a dense layer. And the cost will be high.

Japanese Patent Laid-Open No. 10-245721 JP-A-10-57816 JP 2006-104605 A

As described above, many proposals have been made for acrylonitrile-based fibers containing a photocatalyst. However, the fiber degradation suppression by photocatalytic action, the effective use of the photocatalyst, the photocatalyst dropout, or the simplification of the manufacturing process, etc. In that respect, it left a problem. An object of the present invention is to provide a functional acrylonitrile-based fiber that can solve these problems and can exhibit a photocatalytic action even for light in the visible light region.

The above object of the present invention is achieved by the following means.
(1) with respect to the acrylonitrile-based polymer to 100 parts by weight of a functional acrylonitrile fiber which visible light responsive photocatalyst fine particles having an average particle size of 50~200nm contain 0.5 to 3.0 parts by weight A functional acrylonitrile fiber, wherein the entire fiber is porous, the visible light responsive photocatalyst is uniformly dispersed in the fiber, and the specific surface area is 10 to 60 m ² / g.
(2) The functional acrylonitrile fiber according to (1), wherein the acrylonitrile polymer contains 40 to 90% by weight of acrylonitrile as its polymerization composition.
(3) A fiber structure containing the functional acrylonitrile fiber according to (1) or (2) .
(4) The function according to any one of (1) to (3) , wherein a spinning stock solution obtained by mixing an aqueous dispersion of visible light responsive photocatalyst fine particles with an acrylonitrile-based polymer solution is spun. For producing a conductive acrylonitrile fiber.

According to the present invention, it is possible to obtain a photocatalyst-containing acrylonitrile fiber that can suppress degradation of the fiber and the photocatalyst and that can exhibit a photocatalytic action even under visible light, by a simple method. Such a fiber makes it possible to provide a textile product having excellent deodorant properties, antifouling properties, antibacterial properties, anti-wrinkle properties and the like in clothing use and interior use.

The acrylonitrile-based polymer in the present invention is such that 40% by weight or more of the polymerization composition is acrylonitrile, preferably 50% by weight or more, and more preferably 80% by weight or more is acrylonitrile. Therefore, as the acrylonitrile-based polymer, a copolymer of acrylonitrile and another monomer can be employed in addition to the acrylonitrile homopolymer. Other monomers in the copolymer are not particularly limited, but vinyl halides and vinylidene halides; (meth) acrylic acid esters (note that (meth) is indicated with or without the word “meta”. Sulfonic acid group-containing monomers such as methallyl sulfonic acid and p-styrene sulfonic acid and salts thereof; carboxylic acid group-containing monomers such as (meth) acrylic acid and itaconic acid and salts thereof; acrylamide, styrene, Examples include vinyl acetate.

The visible light responsive photocatalyst fine particles in the present invention exhibit a photocatalytic action even when irradiated with visible light as well as ultraviolet rays. Thereby, the fiber of this invention can express the deodorizing property with respect to malodor components, such as acetaldehyde, an acetic acid, and ammonia, antifouling property, antibacterial property, etc. also in visible light irradiation. The visible light responsive photocatalyst fine particles have an average particle diameter of 50 to 200 nm, preferably 70 to 150 nm. When the average particle diameter exceeds 200 nm, the fiber strength decreases greatly, the specific surface area of the photocatalyst fine particles decreases, and the photocatalytic action also decreases. In addition, when the average particle diameter is less than 50 nm, the photocatalyst fine particles easily fall off the fibers by washing or the like. On the other hand, by setting the average particle diameter within such a range, it is possible to make it difficult for the photocatalyst fine particles to fall out of the pores even when the fiber has a porous structure described later.

Examples of the visible light responsive photocatalyst fine particles include TS-S4230 (manufactured by Sumitomo Chemical Co., Ltd.), Lunecat (registered trademark, manufactured by Toshiba Materials Co., Ltd.), iLUMiO (registered trademark, manufactured by Sumitomo Chemical Co., Ltd.), and visible light photocatalyst. And 10% sol (Osaka Titanium Technologies Co., Ltd.).

In the functional acrylonitrile fiber of the present invention, the visible light responsive photocatalyst fine particles are 0.5 to 3.0 parts by weight, preferably 1.0 parts per 100 parts by weight of the acrylonitrile polymer constituting the fiber. It is made to contain -2.0 weight part. If the content is less than 0.5 parts by weight, sufficient photocatalytic action cannot be obtained, and if it exceeds 3.0 parts by weight, the fiber strength decreases, and the amount of photocatalyst fine particles falling off in the fiber production process increases extremely. Therefore, it is not easy to produce fibers.

The internal structure of the functional acrylonitrile fiber of the present invention includes a state in which visible light responsive photocatalyst fine particles are localized in the sheath in a core-sheath structure as in the prior art, or a multilayer of a dense layer and a porous layer In the structure, it is possible to adopt a state in which visible light responsive photocatalyst fine particles are localized in the dense layer portion. However, in the present invention, not a complicated structure like this, but a simple structure in which the entire fiber has a porous structure and the visible light responsive photocatalyst fine particles are uniformly dispersed in the fiber. desirable. Such a structure facilitates production, increases the amount of visible light responsive photocatalyst fine particles that can be contained in the fiber by not localizing the photocatalyst fine particles, and provides a porous structure. As a result, not only the surface layer portion of the fiber but also the photocatalyst fine particles in the central portion can be efficiently used, so that excellent deodorizing properties, antifouling properties, antibacterial properties, antifungal properties and the like can be obtained.

According to the prior art, such a porous structure is concerned with a decrease in fiber physical properties and photocatalyst particle dropping due to ultraviolet light irradiation, but in the present invention, it has an average particle diameter in the above-mentioned range. The photocatalyst fine particles can be prevented from dropping out of the pores of the porous structure, and a conventional photocatalyst that requires irradiation with high-intensity ultraviolet light is used by adopting visible light responsive photocatalyst fine particles. Compared with the technology, since the catalytic effect can be exhibited using light having a wavelength up to the visible light region, it is possible to suppress deterioration of the fiber. Further, preventing the fiber from deteriorating can also contribute to the suppression of falling off of the photocatalyst fine particles.

The functional acrylonitrile fiber of the present invention can achieve a tensile strength of 2.0 to 3.5 cN / dtex even when it has a porous structure as described above. Further, as will be described later, it is possible to maintain a tensile strength of 90% or more of the tensile strength before irradiation even after light irradiation. Furthermore, it is possible to achieve 90% or more of the photocatalyst remaining rate described later.

Moreover, in the functional acrylonitrile fiber of the present invention, when the above-mentioned porous structure is adopted, the specific surface area is preferably 10 to 60 m ² / g, more preferably 15 to 60 m ² / g, most preferably. It is desirable to set it as 40-60 m < ² > / g. When the specific surface area exceeds 60 m ² / g, the fiber physical properties may be lowered and the practicality may be poor. On the other hand, if it is less than 10 m ² / g, a part of the photocatalyst fine particles contained in the fiber may not be sufficiently utilized.

Examples of the fiber structure containing the functional acrylonitrile fiber of the present invention include yarn, yarn (including wrap yarn), filament, woven fabric, knitted fabric, pile fabric, non-woven fabric, paper-like material, sheet-like material, laminate, and cotton. And the like (including spherical and massive ones). Specific examples include underwear, stomach wraps, supporters, gloves, socks, stockings, pajamas, bathrobes, towels, mats, rugs, carpets, and bedding. In forming the fiber structure, the functional acrylonitrile fiber of the present invention may be used alone, or a natural fiber, an organic fiber, a semi-synthetic fiber, a synthetic fiber, or an inorganic fiber that is publicly used. Further, glass fiber or the like can be used in combination. The ratio of the functional acrylonitrile fiber of the present invention in the fiber structure is derived from the photocatalytic action such as deodorizing property, antifouling property, antibacterial property and anti-wrinkle property required for the use of the fiber structure. May be selected as appropriate so as to satisfy the characteristics and mechanical characteristics.

As described above, the method for producing the functional acrylonitrile fiber of the present invention comprises mixing a visible light responsive photocatalyst fine particle into a solution in which an acrylonitrile polymer is dissolved in a solvent to prepare a spinning dope, and spinning the solution. The method of obtaining a fiber can be mentioned. Here, examples of the solvent for dissolving the acrylonitrile-based polymer include organic solvents such as dimethylformamide, dimethylacetamide, and dimethylsulfoxide, and inorganic salt solvents such as nitric acid, zinc chloride aqueous solution, and sodium thiocyanate aqueous solution.

The visible light responsive photocatalyst fine particles are preferably mixed as a dispersion liquid such as an aqueous dispersion rather than as dry fine particles. By mixing in a dispersed liquid, the visible light responsive photocatalyst fine particles are not agglomerated in the obtained fiber and can be uniformly dispersed, so that the decrease in fiber strength is suppressed and the photocatalytic action is further improved. It can be expressed efficiently.

As spinning conditions, conventionally known spinning conditions can be employed. For example, if the functional acrylonitrile fiber of the present invention having a porous structure is produced using an inorganic salt solvent such as sodium thiocyanate, the following method can be employed. First, after dissolving the above-mentioned acrylonitrile polymer in an inorganic salt solvent, a spinning stock solution in which visible light responsive photocatalyst fine particles are directly added or mixed as an aqueous dispersion is prepared, and after spinning from a nozzle, coagulation, water washing, Through each step of drawing, the moisture content of the undried fiber after drawing is 50 to 130% by weight, preferably 60 to 120% by weight. Subsequently, the functional acrylonitrile fiber of the present invention having a porous structure is obtained by performing wet heat treatment at 105 ° C. to 130 ° C., preferably 110 ° C. to 125 ° C., and then drying at or below the wet heat treatment temperature.

Here, the moisture content of the undried fiber after stretching is determined by the following method. First, the stretched undried fiber is immersed in pure water, and then dehydrated for 2 minutes under a centrifugal acceleration of 1100G (G indicates gravitational acceleration). After dehydration, the weight is measured (W3), the undried fiber is dried at 120 ° C. for 15 minutes, and the weight is measured (W2).
Moisture content of undried fiber after stretching (%) = (W3−W2) / W2 × 100

There are many methods for controlling the moisture content of the undried fiber after stretching. To control the moisture content within the above range, the coagulation bath temperature is about 1 ° C. to 15 ° C., and the stretching ratio is about 7 to 15 times. Is desirable. The spinning conditions are the same even when an organic solvent is used as the solvent. However, the coagulation bath temperature is preferably 40 ° C. or higher in order to control the moisture content of the undried fiber after stretching within the above range.

Although the fiber obtained by such a method has a porous structure, specifically, a microvoid is connected to the inside of the fiber and communicates with the surface, and the visible light responsive photocatalyst present inside the fiber The photocatalytic action can be used more effectively.

EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the scope of the present invention is not limited thereto. Parts and percentages in the examples are on a weight basis unless otherwise indicated.

(1) Average particle diameter The average particle diameter was measured by a dynamic light scattering method using ELS-Z (manufactured by Otsuka Electronics Co., Ltd.).

(2) a specific surface area fibers 10mg cut into short fibers, was evaluated by Shimadzu MICROMERITICS Auto Pore IV to mercury pressure ^{4.14 × 10 -2 ~4.14 × 10 2} MPa. Since the obtained pore surface area (A1) includes inter-fiber voids, the pore surface area of the fiber was determined by subtracting the inter-fiber void (A2) according to the following formula.
Fiber pore surface area = A1-A2
A1: pore surface area of the mercury pressure ^{4.14 × 10 -2 ~4.14 × 10 2} MPa A2: pore surface area of the mercury pressure 4.14 × ¹⁰ -2 ~1.38MPa

(3) Strength retention The tensile strength of the sample fiber is measured based on JIS-L-1015 “Chemical Fiber Staple Test Method”. Further, the tensile strength is measured in the same manner for a sample fiber using black light as a light source and irradiated at an illuminance of 300 lux for 1000 hours. The strength retention was calculated from the obtained measured value by the following formula.
Strength retention (%) = tensile strength after irradiation / tensile strength before irradiation × 100

(4) 0.1 g of deodorant sample was sealed in a 1.5 L film bag, and then 1.5 L of 50 ppm acetaldehyde gas prepared with 20 ° C. and 65% RH air was injected. A fluorescent lamp was used as a light source, and after irradiation for 24 hours at an illuminance of 500 lux, the residual gas concentration in the film bag was measured with an acetaldehyde detector tube, and the deodorization rate (%) was calculated by the following formula.
Deodorization rate (%) = [(50−residual gas concentration) / 50] × 100

(6) Photocatalyst residual rate 1 g of the sample was dissolved in 25 g of γ-butyrolactone to separate the photocatalyst contained in the fiber, and the amount of photocatalyst (W1) was measured. On the other hand, the photocatalyst amount (W2) after washing was measured in the same manner for the sample that had been treated 10 times, and the residual rate was calculated according to the following formula.
Photocatalyst residual rate (%) = (W2 / W1) × 100
Washing was performed according to JIS-L-0213 method 103 (for home use washing machines).

[Example 1]
An acrylonitrile polymer was prepared by aqueous suspension polymerization of 90% by weight of acrylonitrile, 9% by weight of methyl acrylate, and 1% by weight of sodium methallylsulfonate. TS-S4230 (Sumitomo Chemical Co., Ltd.), which is an aqueous dispersion of visible light responsive photocatalyst fine particles, is prepared by dissolving an acrylonitrile polymer in an aqueous solution of sodium thiocyanate having a concentration of 45% by weight to a concentration of 12% by weight. Were added and mixed to prepare a spinning dope with a weight ratio of acrylonitrile polymer to visible light responsive photocatalyst fine particles of 100: 3.0. The stock solution is extruded into a 15% by weight, + 1.5 ° C. sodium thiocyanate aqueous solution, then washed with water, stretched 12 times, wet-heat treated at 115 ° C. for 10 minutes, and dried with a hot air dryer at 110 ° C. The functional acrylonitrile fiber of the present invention having a texture structure and 1 dtex was prepared. The properties of the obtained fiber are shown in Table 1. Moreover, when the cross section of the obtained fiber was analyzed by EDX, it was found that the visible light responsive photocatalyst fine particles were uniformly dispersed.

[Example 2]
A functional acrylonitrile fiber was obtained in the same manner as in Example 1 except that iLUMiO (registered trademark, manufactured by Sumitomo Chemical Co., Ltd.) was used as an aqueous dispersion of visible light responsive photocatalyst fine particles. Table 1 shows the physical properties of the obtained fiber.

[Example 3]
A functional acrylonitrile fiber was obtained in the same manner as in Example 1 except that it was densified by performing hot air drying at 120 ° C. for 10 minutes before wet heat treatment at 115 ° C. for 10 minutes. Table 1 shows the physical properties of the obtained fiber.

[Example 4]
A functional acrylonitrile fiber was obtained in the same manner as in Example 1 except that the weight ratio of the acrylonitrile polymer and the visible light responsive photocatalyst fine particles was 100: 1.0. Table 1 shows the physical properties of the obtained fiber.

[Example 5]
A functional acrylonitrile fiber was obtained in the same manner as in Example 1 except that the weight ratio of the acrylonitrile polymer and the visible light responsive photocatalyst fine particles was 100: 0.5. Table 1 shows the physical properties of the obtained fiber.

[Comparative Example 1]
Functional acrylonitrile fiber in the same manner as in Example 1 except that an aqueous dispersion of an ultraviolet light responsive photocatalyst AMT-600 (manufactured by Teika Co., Ltd.) is used instead of the aqueous dispersion of visible light responsive photocatalyst fine particles. Got. Table 1 shows the physical properties of the obtained fiber.

[Comparative Example 2]
A functional acrylonitrile fiber was obtained in the same manner as in Example 1 except that the weight ratio of the acrylonitrile polymer and the visible light responsive photocatalyst fine particles was 100: 0.3. Table 1 shows the physical properties of the obtained fiber.

[Comparative Example 3]
A functional acrylonitrile fiber was obtained in the same manner as in Example 1 except that the weight ratio of the acrylonitrile polymer and the visible light responsive photocatalyst fine particles was 100: 5.0. Table 1 shows the physical properties of the obtained fiber.

As shown in Table 1, in Examples 1 and 2, if it was a visible light responsive photocatalyst, a functional acrylonitrile fiber that exhibited a photocatalytic function under visible light could be obtained regardless of the type. Further, the fiber physical properties can be sufficiently maintained, and the fiber structure can be sufficiently processed. In Example 3, densified fibers were obtained. Such a product exhibits a deodorization rate of 90% or more, but the deodorization rate was slightly lower than those of Examples 1 and 2 having a porous structure. In Example 4, the addition amount of visible light responsive photocatalyst fine particles is one third of that in Example 3, but 100% deodorizing property is exhibited, and having a porous structure exhibits the photocatalytic function. It turns out that it is advantageous. In Example 5, although the photocatalyst addition amount was reduced, it turns out that it has a deodorizing performance of 90% or more. Moreover, it can be confirmed that the decrease in fiber properties is small when the amount of the photocatalyst fine particles added is small.

On the other hand, in Comparative Example 1, a photocatalyst with a small average particle size that is not a visible light responsive type was used, but even if the addition amount is the same, performance under visible light is hardly seen. In addition, since the average particle diameter is small, it is considered that the photocatalyst fine particles dropped off from the pores of the porous structure, and the photocatalyst residual rate was lowered. Comparative Example 2 is an example in which the addition amount of the photocatalyst fine particles is reduced, and although the fiber physical properties are not impaired, it is understood that the deodorization rate is lower than that of the Examples and the performance of the photocatalyst is greatly reduced. Comparative Example 3 is an example in which the addition amount of the photocatalyst fine particles is increased. Although the function as a photocatalyst is exhibited, the fiber physical properties are extremely lowered and it is difficult to perform practical processing.

Claims (4)

A functional acrylonitrile fiber containing 0.5 to 3.0 parts by weight of visible light responsive photocatalyst fine particles having an average particle diameter of 50 to 200 nm with respect to 100 parts by weight of an acrylonitrile polymer , the entire fiber Is a porous acrylonitrile fiber, wherein the visible light responsive photocatalyst is uniformly dispersed in the fiber, and the specific surface area is 10 to 60 m ² / g. The functional acrylonitrile fiber according to claim 1, wherein the acrylonitrile polymer contains 40 to 90% by weight of acrylonitrile as a polymerization composition thereof. Claim 1 or 2 fiber structure containing the functional acrylonitrile fiber according to. The functional acrylonitrile fiber according to any one of claims 1 to 3 , wherein a spinning stock solution obtained by mixing an aqueous dispersion of visible light responsive photocatalyst fine particles with an acrylonitrile polymer solution is spun. Production method.