JPH076086B2 - Method for producing shrinkable polyvinyl alcohol-based filament - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to the production of a polyvinyl alcohol (hereinafter abbreviated as PVA) -based filament having excellent shrinkability which exhibits a high shrinkage ratio in a short time in hot water at 36 ° C. It is about the method.

(Prior Art) Conventionally, a method for producing a shrinkable PVA fiber is disclosed in Japanese Examined Patent Publication No.
It is known from Japanese Patent No. 652 and Japanese Patent Laid-Open No. 60-2709. These known methods are methods for producing fibers by a wet spinning method, but after spinning and drawing, drying and heat treatment are performed in a state of containing salts in the coagulation bath, and then in order to further remove salts. It is washed with water, and then dried.

(Problems to be solved by the invention) However, in the conventional method as described above, there are many production steps in which fibers are stuck or adhered in the drying step after washing and removing salts in the coagulation bath, which is economically disadvantageous. Inferiority, and in terms of the performance of the obtained fiber, there are problems that it takes a long time to start shrinking even if it is immersed in warm water because it has many drying steps.

Therefore, an object of the present invention is to provide a method for economically producing a PVA-based fiber which is free from fiber sticking and adhesion and has excellent shrinkability in water.

(Means for Solving the Problems) The inventors of the present invention have conducted extensive studies to achieve the above-mentioned object, and as a result, have found that the coagulation bath adhered to the filament remains in the filament shape having a specific thickness. The present invention has been achieved by finding that the above object can be achieved by washing salts with water and then hot-drawing under specific conditions.

That is, according to the present invention, an aqueous solution of PVA is wet-spun to cause shrinkage.
When producing PVA fiber, after spinning, spinning and wet heat treatment so that the total denier during washing with water becomes 300 to 6600 denier, wash the salt adhering to the fiber with water, rinse with oil, and dry and When immersed in hot water at 36 ℃, which is characterized by performing 1.5 times or more hot drawing at 165 ℃
The gist is a method for producing a shrinkable PVA filament which shrinks by 50% or more within 10 seconds.

The spinning, spin-drawing and wet heat treatment of the PVA type filament in the present invention can be carried out by a conventionally known method and apparatus. The spinning in the present invention needs to be carried out so that the total denier of the filament at the time of washing with water (denier measured by a usual method after collecting the filament after washing with water) is 300 to 6600 denier, preferably 600 to 3000 denier. Is. In the present invention, the spin drawing is 2
It is preferable to carry out at least twice.

In the present invention, the salt adhering to the filament is washed with water after the moist heat treatment. In the present invention, it is desirable to completely remove salts by washing with water. In the present invention, the filament is washed as it is, but since the thickness of all filaments at the time of washing is 300 to 6600 denier,
Even if the filament is under tension, it is possible to completely remove salts by washing with water. When the thickness of all filaments when washed with water is less than 300 denier, adhesion between filaments is slightly seen and productivity is inferior, which is not preferable. On the other hand, when it exceeds 6600 denier, salts are completely removed under stress. Since it is difficult to do so, the heat drawability is inferior, and as a result, the shrinkage characteristics of the filament are degraded, which is not preferable. For the washing with water, a known washing method and apparatus for filament can be appropriately adopted. In the present invention, oil washing, drying and hot drawing are performed after washing with water. The oil treatment may be performed by a known method. Drying after the oil treatment is preferably performed at a low temperature of 60 to 90 ° C. In the present invention, after the filament is dried, it is necessary to perform hot stretching at 120 to 165 ° C. at a rate of 1.5 times or more.

When trying to perform 1.5 times the heat drawing, the heat drawing temperature is 105 ℃.
In that case, it is difficult to stretch and there is a problem in operability. At 120 ° C
When the filament that has been drawn 1.5 times is immersed in warm water at 36 ℃, the shrinkage is 52% after 10 seconds and 53% after 60 seconds.
It showed 53% after 2 seconds and reached equilibrium in a short time. Similarly 165 ° C
The contraction rate of filaments that had been heat-stretched by 1.5 times was 50% after 10 seconds, 50% after 30 seconds, and 51% after 60 seconds, and reached equilibrium in a short time. However, the shrinkage rate of filaments subjected to 1.5 times heat drawing at 180 ° C was 3% after 10 seconds, 28% after 30 seconds, 37% after 60 seconds and 38% after 3 minutes. Thus, as the stretching temperature increases, the shrinkage rate decreases, the shrinkage rate decreases, and it tends to take time to reach equilibrium.

On the other hand, in the case of hot drawing at 150 ° C, the shrinkage ratio when the filament drawn by 2.2 times was immersed in hot water at 36 ° C was 64% after 10 seconds, 65% after 30 seconds, and 60% after 60 seconds. It showed 66% and reached equilibrium in a short time. However, the shrinkage rate of filaments that had been heat-stretched only 1.4 times was 40% after 10 seconds and 42% after 30 seconds.
%, 43% after 60 seconds. Thus, as the draw ratio decreases, the shrinkage ratio tends to decrease.

As described above, when immersed in hot water at 36 ° C, 50
The stretching temperature is 120 to obtain filaments that shrink more than 100%.
It is necessary that the heat draw ratio is 1.5 times or more, preferably 1.6 times or more, at 165 ° C, preferably 130 ° C to 160 ° C.
As described above, according to the present invention, it becomes possible to easily manufacture various filaments having different shrinkage ratios only by changing the hot stretching conditions.

The filament obtained by the method of the present invention can be used in the filament-like shape as it is, and can be directly sewn or attached to an object requiring contraction. Further, the filament can be used as a twisted yarn, and can be mixed and twisted with a high-strength type filament in accordance with the application, for example, for those requiring strength. The filament can also be used as a cloth. Applications of filaments obtained by the method of the present invention include: Molton rollers for printing, ham,
There are applications such as tightening tie cords for meat, crafts, paper, cloth thighs and abdomen, sanitary napkins, etc. that require contraction by water. For example, in the case of disposable diapers,
When attaching, it is easier to attach if the thigh is not contracted, and it is preferable that it fits around the thigh immediately after attachment due to sweat or urine discharged from the body. It is desirable to have filaments that shrink 50% or more within 10 seconds when immersed in warm water. In the case of a paper diaper, conventionally, the problem of urine leaking from the abdomen and back due to the large amount of urine discharged at bed time and the problem of urine leaking from the thigh due to slow fiber contraction are obtained by the method of the present invention. By using the filament, the filament is contracted immediately after the urine is discharged and fits the body so that the structure does not leak urine to the outside.

(Example) Hereinafter, the present invention will be described in more detail with reference to examples.

The contraction rate in hot water at 36 ° C in the example is measured by measuring the length of the filament after immersing it in the hot water at 36 ° C with an initial load of 1 mg per denier. It is what I asked for.

Examples 1 to 4, Comparative Examples 1 and 2 PVA having an average degree of polymerization of 1680 was dissolved in water to a concentration of 15.7% by weight to prepare spinning dope. This spinning dope was spun into a coagulation bath with a Glauber's salt concentration of 426 g / l and spun and drawn 2.4 times between the first and second rollers, then the Glauber's salt concentration was 230 g / l.
The total denier is 975 by performing the wet heat treatment at 95 ℃ in the bath of 1
Got a denier filament. Then, this filament was washed with water at 30 ° C under tension, further treated with an oil agent, and dried at 60 to 90 ° C. Then, the thermal draw ratio was kept constant at 1.5 times, and only the hot draw temperature was 120 ° C. ℃ (Example 1), 135 ℃ (Example 2), 150 ℃ (Example 3), 165 ℃ (Example 4), 105 ℃ (Comparative Example 1), 180 ℃ (Comparative Example 2), Heat drawing was performed. The filament obtained was 250 filament and the total denier was 650 denier. However, when the hot drawing temperature was 105 ° C. (Comparative Example 1), the filament was cut during the drawing, so that no sample was obtained.

In each of Examples 1 to 4 and Comparative Example 2, the operability was good, and neither stickiness nor adhesion was observed in the filaments obtained.

Table 1 shows the results of measuring the shrinkage ratio of the obtained multifilament in hot water at 36 ° C.

Examples 5 to 9 and Comparative Examples 3 to 8 A drying process was performed under the same conditions as in Example 1, and then a second step was performed.
11 kinds of filaments with different hot drawing conditions were obtained by hot drawing at various hot drawing temperatures and hot draw ratios shown in the table.
The filament obtained was 250 filament, and the total denier when washed with water was 975 denier.

In each of Examples 5 to 9 and Comparative Examples 3 to 8, the operability was good, and the filaments obtained did not show sticking or adhesion.

Table 2 shows the results of measuring the shrinkage ratio of the obtained multifilament in warm water at 36 ° C.

Example 10, Comparative Examples 9, 10 Total denier at the time of washing with water was 200 denier (Comparative Example 9),
A filament was obtained in the same manner as in Example 3 except that 3000 denier (Example 10) or 7500 denier (Comparative Example 10) was used.

In the case of Example 10, the stretchability was good, and no sticking or adhesion was observed in the filament obtained. On the other hand, in the case of Comparative Example 9, the stretchability was poor and cutting occurred, and the obtained filament was also observed to have adhesion, and in the case of Comparative Example 10, the washing in the water washing step was not sufficient, so Not only was the drying insufficient, but the stretchability was also poor and fluffing was observed.

Reference Example 1 A paper diaper was prepared by using a polyester nonwoven fabric as a surface material, a cotton-like pulp and a polymer absorbent as an absorbent material, and a polyethylene film as a waterproof material, similarly to a commercially available paper diaper. 2 rows of multifilaments were sewn on the thighs of the disposable diaper with two rows.
When 150 cc of hot water at 36 ° C was added to this disposable diaper, the circumference of the thigh contracted 60% after 10 seconds.

(Effects of the Invention) According to the present invention, it is possible to economically produce a PVA-based filamentment having no sticking or adhesion of fibers and having excellent shrinkability in water. Further, according to the present invention, the shrinkage ratio of filament can be adjusted only by changing the conditions of hot stretching. The filament obtained by the method of the present invention has a characteristic that it shrinks by 50% or more within 10 seconds when immersed in warm water at 36 ° C. Therefore, for example, a printing Molton roller, a tightening tie, a diaper or a sanitary product is used. It is preferably used for napkins and the like.

Claims (1)

[Claims] 1. When a shrinkable polyvinyl alcohol fiber is produced by wet spinning an aqueous solution of polyvinyl alcohol, the fiber is formed by spinning, spinning, and moist heat treatment so that the total denier during washing with water is 300 to 6600 denier. Wash the adhering salt with water, then oil treatment, dry and
A method for producing a shrinkable polyvinyl alcohol-based filament which shrinks by 50% or more within 10 seconds when immersed in hot water at 36 ° C., which is characterized by carrying out hot stretching at a ratio of 0 to 165 ° C. of 1.5 times or more.