JPH04245916A - Fiber having excellent deodorizing performance - Google Patents

Abstract

PURPOSE:To obtain the subject fiber, composed of polyacrylic acid and PVA in a specific proportion, excellent in removal of malodor such as ammonia or amines and useful as sanitary materials, etc. CONSTITUTION:The objective fiber is composed of polyacrylic acid and PVA at (1/99)-(95/5), preferably (1/99)-(70/30) weight ratio of the aforementioned polyacrylic acid to PVA. The above-mentioned fiber has >=70, preferably >=80 deodorizing index and further >=3g/d tensile strength and >=30% water retention ratio.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to fibers having excellent deodorizing properties, particularly to fibers having excellent deodorizing properties against bad odors such as ammonia and amines.

0002

BACKGROUND OF THE INVENTION In recent years, people have become more affluent and are seeking a more comfortable living environment. One of these is the desire for a living environment free of bad odors, and as a result, demand for technology that removes bad odors is increasing.

[0003] There are many types of bad odors, but the main ones are ammonia, amines, and hydrogen sulfide. These odors not only make people uncomfortable, but in many cases can even act as neurotoxins.

Conventionally, various studies have been made to eliminate these bad odors. One example is the use of substances with deodorizing properties such as activated carbon, metal complexes (catalysts) such as metal-porphyrins, and metal oxides in powder form, mainly in diaper covers and bedding products for the elderly. The surface of the fiber fabric was coated with resin. Also, JP-A-60-6984 and JP-A-60-6985
The publication discloses that metal-phthalocyanine compounds are supported on polyvinyl alcohol fibers or acrylic fibers, and Japanese Patent Publication No. 2-44952 discloses that metal-porphyrin compounds are supported on polyvinyl alcohol fibers through special treatment. It has been disclosed that a deodorizing effect can be imparted to fibers through the oxidizing action of metal complexes.

However, although the deodorizing performance of these textile products is quite satisfactory, there are limitations due to the use of powder, coating techniques, and special treatments to support metal complexes on the fibers. There were drawbacks such as the need for

[0006] Therefore, it is thought that if the fiber matrix itself had deodorizing ability, the above-mentioned drawbacks would be overcome and the demands of people who desire a comfortable life free of bad odors would be met.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to provide fibers that have excellent deodorizing performance, particularly against ammonia, amines, etc., by modifying the fiber matrix itself.

[0008]

[Means for Solving the Problems] The above-mentioned object of the present invention consists of polyacrylic acid and polyvinyl alcohol (hereinafter abbreviated as PVA), and the weight ratio of the polymers is 1/99 to 95/5.
This problem can be solved by using fibers that have an excellent deodorizing performance and have a deodorizing index of 70 or more, which will be described later.

That is, first, the fiber of the present invention contains polyacrylic acid and PVA in a weight ratio of 1/99 to 95/5, preferably 1/99 to 80/20, more preferably 1/99 to 95/5.
Consists of a 70/30 blend of polymers.

[0010] At this time, if the polyacrylic acid content in the blend polymer is less than 1% by weight, sufficient deodorizing properties cannot be obtained, whereas if the polyacrylic acid content exceeds 95% by weight, the strength of the resulting fibers decreases. In addition, the water resistance decreases, making it difficult to handle in high-order processing.

Furthermore, the fiber of the present invention has a deodorizing index of 70 or more, preferably 80 or more, as described below. If the deodorizing index is less than 70, the deodorizing ability, especially the quick effect, will not be sufficient during use, and the product will be extremely unsatisfactory in eliminating the discomfort caused by bad odors. The deodorizing index here is defined as follows. That is, 3 g of fiber sample was placed in a container (volume: 500 cc) whose initial concentration was adjusted to 100 ppm of ammonia and 5 ppm of trimethylamine.
), and after 20 minutes, the residual gas concentration in the container was measured using the detection tube method. From this measurement method, the deodorizing index of each component was determined using the following formula.

0012

[Math 1]

[0013] Furthermore, the tensile strength of the obtained fibers may be required to be higher than a certain level for ease of handling in subsequent high-order processing steps or for stress support such as in industrial material applications, and is 3 g/d. It is desirable that it is above, and more desirably it is 4 g/d or more.

The degree of polymerization of PVA is not particularly limited, but is preferably from 500 to 5,000. In addition, in order to increase the strength of the obtained fibers, generally speaking, as the polymerization degree of the polymer increases, the strength also tends to increase.
The degree of polymerization is more preferably from 1,000 to 5,000, and even more preferably from 1,500 to 5,000.

[0015] The fibers of the present invention desirably have water absorption performance with a water retention rate of 30% or more. Having this kind of water-absorbing ability allows it to absorb and retain not only bad odors but also excreted body fluids and sewage, such as diaper covers and industrial sewage treatment, making cleanup and post-treatment very efficient. It has the advantage of being easy to perform.

Next, an example of manufacturing the fiber of the present invention will be explained. First, the weight ratio of polyacrylic acid and PVA is 1/9.
Dissolve in a solvent so that the ratio is 9 to 95/5. The polymer concentration at this time can be appropriately selected depending on the spinning method and spinnability, but it is preferably 10 to 50 wt%, and at this time, a buffer may be added as appropriate to adjust the pH of the stock solution for the purpose of stabilizing the stock solution. . Any polymer solvent may be used as long as it has sufficient solubility for PVA or polyacrylic acid, and examples thereof include water, dimethyl sulfoxide, and a mixed solvent thereof.

[0017] As a spinning method for the above-mentioned spinning dope, wet spinning, dry spinning, dry-wet spinning, etc. can be applied. Among these, dry spinning is preferred from the viewpoint of productivity, and dry-wet spinning is preferred from the standpoint of increasing the strength of the resulting fibers.

[0018] That is, in dry spinning, there is no bath liquid resistance in a coagulation bath as seen in wet spinning or dry-wet spinning, so that high speed spinning is possible. In this dry spinning, the above-mentioned spinning stock solution is discharged into the air at an ambient temperature of 80 to 150° C. through a spinneret, the solvent is removed, and an undrawn yarn is obtained.

On the other hand, in wet-dry spinning, the spindle is placed above the surface of the coagulating liquid, so the spinning dope can be kept at a high temperature, and at the same time
Be able to handle polymers with a high degree of polymerization. Therefore, it is possible to obtain an undrawn yarn with a dense structure. When the fiber is then stretched to a high magnification in the stretching process, the molecular chains are highly oriented and a high strength fiber is obtained.

In this dry-wet spinning, the above-mentioned spinning dope is discharged into the coagulation bath from a nozzle placed 3 to 50 mm above the surface of the coagulation bath. The coagulation bath liquid is compatible with the polymer solvent, but non-solvents such as methanol, ethanol, acetone, etc., and mixed solvents of these with dimethyl sulfoxide and water are suitable for the polymer. used.

[0021] Thereafter, the coagulated undrawn yarn is thoroughly extracted and washed with methanol or acetone, and then cold-stretched 2 to 6 times as needed, followed by drying.

Next, the yarn thus obtained is subjected to hot drawing. Hot stretching methods include heating tubes and heating rollers.
Any method such as a hot plate, heating pin, heating liquid, etc. may be used. However, if the stretching temperature is too high, the hydroxyl groups of PVA and the carboxyl groups of polyacrylic acid will form crosslinks through an esterification reaction due to the heat during stretching, reducing the number of carboxyl groups necessary for deodorization. . Therefore, especially in the fiber of the present invention, it is desirable to control the stretching temperature so as to suppress this, in order to impart deodorizing performance against bad odors. That is, in order to orient the molecular chains of the fibers by stretching and suppress the esterification reaction, it is preferably 230°C or lower, more preferably 180°C or lower.
It is preferable to stretch at a temperature of .degree. C. to 220.degree. In an atmosphere at a temperature of 220° C. or higher, unreacted carboxyl groups are reduced due to the esterification reaction due to heat, and sufficient deodorizing performance may not be obtained, which is not preferable.

[0023]

[Examples] The present invention will be specifically explained below with reference to Examples. Note that the tensile strength, elongation, and water retention rate of the fibers in this example are values determined as follows.

(1) Tensile strength, elongation JIS-L-1
The measurement was carried out in accordance with the measurement method specified in 017. That is, after leaving the fiber sample in a room whose temperature and humidity are adjusted to 20°C and 65% RH for 48 hours, "Tensilon" DTM
-4L type tensile testing machine (manufactured by Toyo Baldwin Co., Ltd.)
The measurement was carried out using a sample length of 25 cm and a tensile speed of 30 cm/min.

(2) Water retention rate (WR) After drying a fiber sample at 80°C for 60 minutes, its weight (
W1) is measured. Then, the weight (W2) after immersing the sample in water for 60 minutes and centrifugal dehydration at 1000 G for 15 minutes is measured, and the water retention rate (WR) is calculated using the following formula.

[0026]

[Math 2]

Examples 1 to 6 A 25 wt % aqueous solution of PVA with a degree of polymerization of 3300 and polyacrylic acid with a degree of polymerization of 400 was prepared at a polymer weight ratio of 98/2 (Examples 1 and 5), 70/30 (Example 2, 6), 60/4
0 (Example 3) and 40/60 (Example 4), and each was dispersed and dissolved in dimethyl sulfoxide so that the total polymer concentration was 15 wt% to prepare a spinning dope.

Next, each spinning stock solution was mixed with a pore size of 0.08 to 0.
．． The thread is discharged from a 10 mm diameter mouthpiece with 50 holes through a 5 mm gas phase into a methyl alcohol bath containing 2 to 8 wt% dimethyl sulfoxide to form a coagulated thread, and then thoroughly extracted and washed in methyl alcohol. The yarn was then cold-stretched by about 3 times at room temperature to obtain a primary drawn yarn.

Subsequently, after drying the methanol in the yarn, 1
Dry heat stretching was performed at an ambient temperature of 90 to 240°C. Table 1 shows the physical properties of the obtained fibers. Table 2 also shows the results of the evaluation of the odor deodorizing performance of the obtained fibers and the water retention rate. All samples showed excellent deodorizing index against ammonia and amines, and also had excellent water retention.

Examples 7 and 8 A 25 wt % aqueous solution of PVA with a degree of polymerization of 2400 and polyacrylic acid with a degree of polymerization of 400 was mixed in a polymer weight ratio of 70/30 (
Example 7) and 10/90 (Example 8) were mixed to give a total polymer concentration of 32wt% and 25w, respectively.
A spinning dope was prepared by dispersing and dissolving in water such that the concentration was t%.

[0031] Next, the spinning dope was prepared using a pore size of 0.10 mmφ.
After removing the solvent and obtaining an undrawn yarn by discharging it into the air at an ambient temperature of 130°C from a nozzle with 50 holes, it was cold-stretched about 3 times, and then dried in an ambient temperature of 220°C. Table 1 shows the physical properties of the fibers obtained by hot drawing. Also,
Table 2 also shows the results of the evaluation of the bad odor deodorizing performance of the obtained fibers and the water retention rate. All samples showed excellent deodorizing index against ammonia and amines, and also had excellent water retention.

Comparative Example 1 A 25 wt % aqueous solution of PVA with a degree of polymerization of 3300 and polyacrylic acid with a degree of polymerization of 400 was prepared in a polymer weight ratio of 99.5/0.
．． Table 1 shows the physical properties of the fibers obtained by spinning and drawing under the same conditions as in Example 1, except that the fibers were mixed so that the results were 5. Table 2 shows the results of the odor deodorizing performance evaluation and the water retention rate. Ta. Although the tensile strength of the fiber is high, ammonia,
The deodorizing index for amines was extremely low, and the water retention was also poor.

Comparative Example 2 PVA with a degree of polymerization of 2400 and a 25 wt% aqueous solution of polyacrylic acid with a degree of polymerization of 400 were mixed at a polymer weight ratio of 2/98, and the total polymer concentration was 22 w.
A spinning dope was prepared by dispersing and dissolving in water such that the concentration was t%. Next, the spinning stock solution was passed through a tube with a hole diameter of 0.12 mmφ and a number of holes of 50.
The material was discharged from the nozzle into air at an ambient temperature of 140° C. for dry spinning, but stable spinning could not be achieved.

[0034]

[Table 1]

[0035]

[Table 2]

[0036]

Effects of the Invention The fiber of the present invention, which is made of polyacrylic acid and PVA, has a deodorizing index of 70 or more against bad odors, especially ammonia and amines, and the fiber matrix itself has excellent deodorizing performance. It can exhibit excellent effects in fields such as air purifiers.

Claims (2)

[Claims] Claim 1: An excellent deodorizer comprising polyacrylic acid and polyvinyl alcohol, the weight ratio of the polymers being 1/99 to 95/5, and having a deodorizing index of 70 or more as described in the text. Fiber with performance. 2. The fiber according to claim 1, which has excellent deodorizing performance and has a tensile strength of 3 g/d or more and a water retention rate of 30% or more.