JPH0913221A - High-strength acrylic fiber having antibacterial and antifungal properties and its production - Google Patents

Abstract

PURPOSE: To obtain a high-strength acrylic fiber provided with antibacterial and antifungal properties without deteriorating the physical properties of the fiber and useful for a general industrial material by allowing the fiber to hold an antibacterial and antifungal metal ion as a metal compound state. CONSTITUTION: A metal ion (the ion of silver, copper, zinc, etc.) having antibacterial and antifungal performances is coordinated to cyano groups in a high strength acrylic fiber having a weight-average mol.wt. of at least 200000, containing acrylonitrile as a main component, and having a tensile strength of >=8g/d. The treated fiber is subsequently treated with an anion capable of being bound to the metal ion to form a slightly water-soluble metal compound. The obtained fiber has a fiber metal ion-holding degree of >=95%, when extracted with 25 deg.C pure water for 24hr.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to an antibacterial and antifungal high-strength acrylic fiber having a high practical performance, which contains a poorly water-soluble metal compound and can be suitably used for general industrial materials. Regarding

[0002]

2. Description of the Related Art Conventionally, acrylic fibers have been produced and sold in large quantities for clothing, but they have hardly been used for industrial or industrial use because of insufficient mechanical strength. Therefore, many attempts to improve the mechanical strength of acrylic fibers have been proposed so far. In Japanese Examined Patent Publication No. 7-11086, an acrylonitrile-based polymer having an intrinsic viscosity of 2.0 or more and 3.5 or less is dissolved so as to have a polymer concentration of 10 to 15% by weight, and the spinning solution is dried and wet-spun. The primary stretching is performed 2 to 8 times under moist heat or steam heat, and after washing with water and drying, dry heat is applied to 1.5 times.
It is described that a high-strength acrylic fiber having a tensile strength of 10 g / d or more can be obtained by performing a stretching of at least twice and setting the effective total stretching ratio to at least 12 times.

However, when the acrylic fiber obtained by such means is used as an industrial sheet obtained by resin coating or resin laminating, for example, a woven fabric of the fiber is used as a reinforcing material, the hydrophilic property which is a characteristic of the acrylic fiber. Due to water migration due to water, water penetrates along the acrylic fiber from the sheet cross section. As a result, the bacteria and mold spores in the water propagate inside the sheet, so that dirt is generated along the acrylic fiber. In recent years, fashionability has been emphasized even in industrial sheets, and the number of white and pastel-colored items has been increasing, so this stain has become a serious problem.

[0004]

When high-strength acrylic fiber is used to reinforce a white or pastel color sheet,
The water that has entered along the fibers causes stains due to the growth of fungi and mold carried inside the sheet, significantly impairing the appearance of the sheet.

[0005]

Under the circumstances, the present inventors have conducted extensive studies to solve the above-mentioned problems, and as a result, by imparting antibacterial and antifungal properties to the high-strength acrylic fiber, It has been found that can also be suitably used.

That is, the present invention comprises an AN-based polymer whose main component is acrylonitrile having a weight average molecular weight of at least 200,000 and has a tensile strength of 8 g / d or more,
Also, the metal compound contained in the fiber has antibacterial and antifungal properties, and the metal ion retention rate in the fiber after extraction in pure water at 25 ° C. for 24 hours is 95% or more. A high-strength acrylic fiber having moldability is provided. Hereinafter, the present invention will be described in detail.

First, in producing the acrylic fiber having a tensile strength of 8 g / d or more, which is the object of the present invention, the molecular weight of the polymer is important, and the weight average molecular weight of the polymer is 200,000 or more, preferably 30. You need to choose more than a million. The molecular weight is the Journal of Pol.
As described in ymer Science (A-1) Vol. 6, pp. 147-159 (1968), the intrinsic viscosity [η] of a polymer in a dimethylformamide (hereinafter referred to as DMF) solvent was measured at 30 ° C. It is calculated by a formula.

[0008]

(Equation 1)

The acrylonitrile-based polymer used as the raw material for the high-strength acrylic fiber used in the present invention has an acrylonitrile ratio of 90% by weight or more, preferably 95% by weight.
There is no particular limitation so long as it is a homopolymer or a copolymer with a known monomer. When the acrylonitrile (hereinafter, also referred to as AN) ratio is less than 90% by weight, chemical resistance is lowered, and when it is used for industrial materials, hydrolysis reaction may proceed and strength may not be maintained.

The comonomer used for copolymerization is not particularly limited as long as it is copolymerizable with acrylonitrile such as other polymerizable unsaturated vinyl compounds, and examples thereof include alkyl acrylate, alkyl methacrylate, acrylic acid, methacrylic acid and methacryloyl. Nitrile, acrylamide, vinyl acetate, vinyl chloride, vinyl bromide, vinyl fluoride, vinyl alkylate, vinylidene chloride, vinylidene bromide, styrene, styrene sulfonic acid, allyl sulfonic acid, methallyl sulfonic acid, styrene sulfonate, allyl Sulfonates, methallyl sulfonates, ethylene, propylene and the like can be used.

Examples of the solvent for the AN polymer thus produced include organic solvents such as DMF, dimethylacetamide and dimethylsulfoxide, and inorganic solvents such as rhodanate, zinc chloride and nitric acid. In terms of the homogeneity of the coagulated gel yarn, the inorganic solvent is excellent, and among them, the rhodanate salt is preferable. In addition, the polymer concentration generally needs to be lowered because the molecular weight of the polymer becomes high, and depends on the type of solvent, the molecular weight of the polymer and the like, and it is difficult to unambiguously define it, but it is generally 7 to 20. Weight percent is preferred.

Either a wet method or a dry method can be adopted as the spinning method. However, since the viscosity is higher than that of an ordinary spinning dope, dry-wet spinning is preferable from the viewpoint of spinnability and is followed. In order to withstand severe drawing, it is preferable to prepare a homogeneous coagulated gel yarn, and therefore it is important to set spinning conditions so that slow coagulation occurs, and when using an inorganic solvent, Low temperature solidification below room temperature is recommended. When an organic solvent is used, it is preferable to perform multistage coagulation by gradually passing through a coagulation bath having a high nonsolvent (precipitating agent).

The gel yarn thus obtained is washed and desolvated in water and / or hot water and drawn 2 to 10 times.
Furthermore, after performing dry densification, dry heat is applied to at least 1.
Stretching is performed 5 times, and the total effective stretching ratio is 12 times, preferably 15 times or more. The dry heat stretching temperature at this time is preferably 140 ° C. or higher, and it is necessary to perform heat setting at a temperature higher than the dry heat stretching temperature by 20 ° C. or higher after the dry heat stretching. The acrylic fiber thus obtained has a tensile strength of at least 9 g / d
The above is suitable for industrial materials.

Next, the details of the antibacterial and antifungal treatment, which is the basis of the present invention, will be described. In the present invention, it is necessary to contain a metal compound formed by an ionic reaction between the metal ion coordinated to the cyano group in the high-strength acrylic fiber and another anion.

Examples of the metal ion coordinated to the cyano group include metal ions having antibacterial activity such as mercury, silver, copper, zinc, iron, lead and bismuth, but more preferably used in the present invention. From the viewpoints of safety and antibacterial effect, it is carried out by adopting at least one metal ion selected from the group consisting of silver, copper and zinc. Of course, it is also possible to use a plurality of types in combination.

Further, as an anion for performing an ionic reaction in combination with the metal ion to form a metal compound, it reacts with the metal ion coordinated to the cyano group in the above-mentioned fiber to cause water failure described later. Any anionic component having the ability to form a soluble compound may be used, but from the viewpoint of safety in use in the present invention and durability of antibacterial effect, pyrophosphoric acid, polyphosphoric acid, silicic acid, aluminate, Tungstic acid, vanadic acid, molybdic acid, antimonic acid, bromine, iodine, sulfur, chloric acid, bromic acid, iodic acid, sulfuric acid, sulfurous acid, thiosulfuric acid, thiocyanic acid, carbonic acid, oxalic acid, benzoic acid, phthalic acid, carboxylic acid It is preferable to use at least one anion component selected from the group consisting of:

The metal compound formed by an ionic reaction between the metal ion and anion and contained in the fiber and having antibacterial and anti-mite properties is required to have poor solubility in water. By having such properties, excellent antibacterial and antifungal properties can be permanently imparted without the metal compound in the fibers falling off or easily eluting. The term “poorly water-soluble” as used in the present invention means that 100 g of pure water at 25 ° C.
It means that the metal ion content of the fibers after the addition of g and stirring treatment for 24 hours, followed by washing with water and drying is 95% or more of the metal ion content of the untreated fibers.

The metal compound having antibacterial and anti-mite properties to be contained in the fiber in the present invention is not particularly limited, but more preferably 1 to 200 m · mol / kg is contained as a metal ion in the fiber. It is good to let
That is, the content of the metal compound varies depending on the required level of antibacterial and antifungal properties. If the content of the metal compound is less than the lower limit of the range, it is difficult to obtain sufficient antibacterial performance in the operating environment. The problem of remarkable coloring tends to occur in a heat treatment process such as drying. Further, within the above range, sufficient antibacterial and antifungal properties for industrial materials can be permanently obtained. Therefore, it is not industrially advantageous to add more than the above-mentioned range because the cost becomes unnecessarily high.

However, due to the feature of the present invention that means for forming and containing a metal compound in the fiber by ion exchange between the metal ion coordinated to the cyano group and another anion as described above, the cyano group is used. After re-coordinating the metal ion to the ion, it can be ion-exchanged with another anion, and the treatment can be performed multiple times instead of once.
If there is no coloring problem, the content of any metal compound can be set without depending on the content of the cyano group contained in the fiber.

The following means can be used as a suitable method for obtaining the above-mentioned antibacterial and antifungal high strength acrylic fiber. That is, the ordinary spinning of the acrylonitrile-based polymer described above is performed, and the high-strength acrylic fiber obtained by washing with water, stretching, and heat treatment as described above is treated with an aqueous metal ion solution to give a metal ion to a cyano group in the fiber. After the first treatment for binding, the second treatment of treating with an aqueous solution of a compound containing an anion capable of forming a poorly water-soluble metal compound by binding with a metal ion is carried out once or more to give a fiber. A sparingly water-soluble metal compound can be contained.

Here, in the first treatment, when treating the high-strength acrylic fiber in an aqueous solution of a compound containing a metal ion exhibiting antibacterial and antifungal properties, the treatment concentration is such that the AN fiber is dissolved or the physical properties are changed. It is not particularly limited as long as it can bond to the cyano group a metal ion that can impart a predetermined amount of a metal compound having antibacterial properties to the fiber without inhibiting it, but the concentration is generally 1 to 500 m · mol / l. Recommended. The treatment temperature may be in the range that does not impair the physical properties of the high-strength acrylic fiber, and is generally 30 to 140 ° C.
Is appropriately selected within the range of, and the processing time is set according to the processing temperature.

The pH of the aqueous solution when treated with an aqueous solution of a compound containing a metal ion exhibiting antibacterial and antifungal properties is
It is sufficient if the metal ion exhibiting antibacterial and antifungal properties is bound to the cyano group, but when the pH is high, metal hydroxide is generated, and it is difficult to introduce the metal ion into the fiber as an aqueous solution. Therefore, it is preferable to treat at about pH = 2-4.

In addition to the above-described treatment method, for example, the gel-structured fibers in the fiber-forming process after spinning may be used to continuously perform the above-mentioned treatment after the water washing step for removing the spinning solvent. Alternatively, the dried fiber after stretching may be continuously subjected to the treatment of the present invention and then subjected to dry heat stretching.

[0024]

The antibacterial and antifungal high-strength acrylic fiber according to the present invention is treated with an aqueous solution of a metal compound having specific antibacterial and antifungal properties on the cyano groups present in the fiber to bind metal ions and By treating with an aqueous solution of a compound containing an anion capable of forming a sparingly water-soluble metal compound by binding with an ion, the metal ion is desorbed from the cyano group in the fiber by an ionic reaction and is bound to the anion. Therefore, it is considered that minute water-insoluble, water-insoluble antibacterial and antifungal metal compounds are generated and retained in the fibers. Further, since the metal compound is imparted to the fiber substantially without intervening the functional group present in the fiber, it is possible to perform the treatment a plurality of times, without depending on the content of the cyano group. The metal compound content can also be set.

[0025]

EXAMPLES Examples will be shown below for facilitating the understanding of the present invention, but these are merely examples, and the gist of the present invention is not limited thereto. In the examples, parts and percentages are shown on a weight basis unless otherwise specified. The metal ion concentration and antibacterial performance described in the examples are measured by the following methods. (1) Metal ion content 0.1 gr fiber was wet decomposed with 95% concentrated sulfuric acid and 62% concentrated nitric acid solution to obtain a solution using an atomic absorption spectrometer AA855 type manufactured by Japan Jarrell Ash Co., Ltd. It was determined by measuring the absorbance. (2) Antibacterial property Based on "Textile Product Hygiene Processing Council""Processing effect test of antibacterial and deodorant processed products", the number of bacteria was measured using Staphylococcus aureus and the difference in increase / decrease value was calculated by the formula 2.

[0026]

(Equation 2)

Here, the difference between increase and decrease is the average number of bacteria immediately after inoculation of the unprocessed sample as A, the average number of bacteria after 18 hours of culture as B, and the average number of bacteria of the antibacterial processed sample after 18 hours of culture. It is calculated as C by the equation 2. Here, the number of measurements is performed three times and the average value is displayed, but it is generally considered that the antibacterial property is present if the increase / decrease value difference is 1.6 or more.

(3) Antifungal property Aspergillas niger, according to JIS Z2911 wet method.
Penicillin citrinumChaetomium globosum, Myrotheci
um verrucaria, Cladosporium cladosporioides bacterium was used for evaluation, and the result of observing the growth condition of the mold with the naked eye is shown in the mold resistance display. The mold resistance display 1 is the mycelia observed in the contacted part of the sample or test piece. Shows the case where the area of the developing part exceeds 1/3 of the whole, and the mold resistance indication 2 shows that the area of the developing part of mycelium observed in the contacted part of the sample or the test piece does not exceed 1/3 of the whole. The mold resistance display 3 shows the case where the growth of hypha was not observed in the contacted portion of the sample or the test piece.

(4) Metal Ion Retention Rate 10 g of fiber was added to 100 g of pure water at 25 ° C., stirred for 24 hours, and then the metal ion content in the fiber was measured for the fiber washed and dried and the original untreated fiber. Then, the metal ion retention rate was calculated by the following equation.

[0030]

(Equation 3)

Example 1 As a high-strength acrylic fiber which is subjected to antibacterial and antifungal treatment,
A polymer having a weight average molecular weight of 200,000 polymerized by charging 95% by weight of acrylonitrile and 5% by weight of vinyl acetate was prepared as a spinning dope by adjusting the polymer concentration to 7% using an aqueous solution of sodium rhodanate as a solvent, and after dry-wet spinning, A fiber having a tensile strength of 10 g / d, which was washed with water, wet-heat stretched, and dry-heat stretched, was obtained at a total effective stretch ratio of 15 times.

As antibacterial and antifungal processing conditions, an aqueous silver nitrate solution as a silver ion solution, a copper sulfate aqueous solution as a copper (II) ion solution, and a zinc chloride aqueous solution as a zinc ion solution are adjusted to 50 m · mol / l, respectively. The aqueous solution 100
After 0 ml of each was adjusted to pH 3 with a 1% aqueous nitric acid solution, 100 g of the fiber prepared above was added, treated at 98 ° C. for 30 minutes, washed with water and dried.

As the second treatment, sodium acid pyrophosphate as an aqueous solution of pyrophosphate ion, sodium aluminate as an aqueous solution of aluminate ion, sodium hydrosulfide as an aqueous solution of sulfur ion, sodium thiocyanate as an aqueous solution of thiocyanate, and an aqueous solution of oxalic acid ion. Sodium oxalate and potassium hydrogen phthalate as an aqueous solution of phthalate ions were adjusted to 30 m · mol / l each, and 100 ml of the aqueous solution was subjected to the above-mentioned first treatment.
Each of them was added at a rate of 0 g, treated at 98 ° C. for 30 minutes, washed with water, dried, and subjected to the first treatment and the second treatment. Nine types of fibers from 2 to 10 were produced.

The obtained fiber No. 2-No. 10 to 25
After pouring the mixture into 100 g of pure water at 100 ° C. and stirring for 24 hours, the metal ion content in the fibers of the fibers washed and dried and the original untreated fibers was measured, and the metal ion retention rate was calculated by the formula 3.

The tensile strength of the fiber, the metal ion retention rate, the difference in the increase / decrease value of the number of bacteria showing antibacterial properties, and the mold resistance showing mold resistance are indicated by the kind of the metal ion of the first treatment and the second treatment. Table 1 together with the types of anions used for
It is shown together.

[0036]

[Table 1]

No. 1 subjected to the first treatment with metal ions and the second treatment with anion treatments In the case of 2 to 10, the tensile strength is 8.0 g / d or more, the metal ion retention rate is 95% or more, and the antibacterial increase / decrease value difference and the mold resistance display are 1.6 or more and 2 or more, respectively, which is good. Antibacterial,
It has mildew-proof properties. On the other hand, the fibers not subjected to the above-mentioned first and second treatments obtained a strength of 10.0 g / d, but showed no antibacterial property or antifungal property.

[0038]

The above-mentioned antibacterial and antifungal high-strength acrylic fiber of the present invention utilizes the cyano group in the fiber for antibacterial,
After introducing a metal ion having antifungal ability, it is treated with an anion that combines with the metal ion to form a sparingly water-soluble metal compound, and thus a finely water-soluble antibacterial metal compound of molecular order is produced in the fiber. And then retained in the fiber. By such a principle, it is possible to provide a fiber that is permanent and has excellent antibacterial and antifungal properties even though it contains a small amount of a metal compound, and that does not impair the fiber physical properties, and to make the fiber industrially advantageous. It is a remarkable effect of the present invention that the method for manufacturing can be provided. The fibers of the present invention having such excellent advantages can be processed into spun yarns, long fibers, knitted fabrics, non-woven fabrics, etc., and are not only industrial materials but also comfortable clothing, bedding, interior products, daily life materials, It can be widely used in fields of application such as medical fiber materials. Of course, in the resin-processed sheet of the fiber of the present invention, despite the invasion of water along the fiber, there is no propagation of fungi or mold, no stain occurs even when used for a long period of time, and the appearance is impaired. There is no.

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Claims (4)

[Claims] 1. An AN polymer mainly composed of acrylonitrile having a weight average molecular weight of at least 200,000.
having a tensile strength of g / d or more, and having antibacterial and antifungal properties by the metal compound contained in the fiber, 25
A high-strength acrylic fiber having antibacterial and antifungal properties, characterized by having a metal ion retention rate of 95% or more in the fiber after being extracted in pure water at ℃ for 24 hours. 2. The high-strength acrylic fiber having antibacterial and antifungal properties according to claim 1, wherein the metal ion component constituting the metal compound is at least one selected from the group consisting of silver, copper and zinc. 3. The anionic component constituting the metal compound is pyrophosphoric acid, polyphosphoric acid, silicic acid, aluminate, tungstic acid,
Vanadic acid, molybdic acid, antimonic acid, bromine, iodine, sulfur, chloric acid, bromic acid, iodic acid, sulfuric acid, sulfurous acid, thiosulfuric acid, thiocyanic acid, carbonic acid, oxalic acid, benzoic acid, phthalic acid, carboxylic acid The high-strength acrylic fiber having antibacterial and antifungal properties according to claim 1 or 2, which is at least one selected from the above. 4. An AN polymer mainly composed of acrylonitrile having a weight average molecular weight of at least 200,000.
A metal capable of forming a metal compound having antibacterial properties and having a metal ion retention rate of 95% or more in the fiber after being extracted in pure water at 25 ° C. for 24 hours on a high-strength acrylic fiber having a tensile strength of g / d or more After the first treatment for coordinating the metal ion to the cyano group in the acrylic fiber with an aqueous solution containing an ion, the metal compound is formed with an aqueous solution containing an anion corresponding to the formation of the metal compound. Second
The method for producing a high-strength acrylic fiber having antibacterial and antifungal properties, characterized in that the above treatment is applied once or more.