JPH1053918A - Polyvinyl alcohol fiber and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject fiber having high non-circularity of the cross-section and excellent mechanical properties, heat-insulation, water-absorption, dyeing and weaving performance and fastness and useful for clothes, etc., by spinning a spinning dope containing a polyvinyl alcohol polymer and a specific amount of a specific phyllosilicate. SOLUTION: This polyvinyl alcohol fiber having a circular length ratio of the cross-section of >=0.85 and a ratio of (the diameter of the maximum inscribed circle)/(the diameter of the minimum inscribed circle) of the fiber cross- section of >=0.35 is produced by spinning a spinning dope containing a polyvinyl alcohol polymer and >=0.05wt.% (based on the polymer) of a swelling phyllosilicate having a cation exchange capacity of >=40mg/100g such as synthetic fluorine mica. Preferably, a fiber structure is produced by compounding the polyvinyl alcohol fiber.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyvinyl alcohol fiber having an irregular cross section and a method for producing the same.

[0002]

2. Description of the Related Art Polyvinyl alcohol (PVA) fibers have a high strength and a high elastic modulus, are highly hydrophilic, and have excellent alkali resistance. Therefore, molding materials (cement, plastic, rubber, concrete, etc.) are used. It is effectively used as a reinforcing material. In a reinforcing fiber, it is important that the mechanical properties of the fiber itself are excellent, but it is also important that the adhesiveness to the material constituting the molded article is high, and that the fiber does not easily come off. Also in filters and the like, fibers having a high degree of irregularity have been desired. From the above, studies have been made to increase the specific surface area without impairing the mechanical performance of the fiber, and specifically, a method for flattening, deforming, or deniering the fiber cross-sectional shape has been proposed. ing.

[0003] For example, as a typical method for producing PVA-based fibers, there is a method in which a PVA spinning solution is wet-spun in a coagulation bath containing inorganic salts having a dehydrating ability. Since a dehydration is performed, a two-layer structure (a skin layer having a dense structure and a core layer having a relatively rough structure) is formed in the cross section of the fiber, and even when the fiber is discharged from the circular nozzle. It becomes a cocoon-shaped cross section as if a round shape was crushed. Although such fibers have a relatively large specific surface area (cross-sectional degree of about 50%, cross-sectional circumference ratio of about 0.8), further improvement is desired.

Although the use of nozzles having irregular cross sections such as Y-type, + -type and --type has been studied, the degree of irregularity of the fiber obtained by spinning is naturally limited, and the productivity is also limited. There was a problem. For example, in the case of the wet or dry-wet spinning method, since the concentration of the stock solution is low and the solvent is rapidly removed in the coagulation bath, when the stock solution is discharged from the nozzle, a large shrinkage occurs in the fiber cross section and the length direction. Because of the surface tension, a force for forming a circular shape is exerted, so that even if the opening is spun with a nozzle having an irregular cross section, the degree of irregularity of the fiber cross section cannot be increased so much.

[0005]

In order to prevent the cross section of the fiber from being circularized due to the surface tension, the separation tension of the undiluted solution from the coagulation bath is increased. A method of maintaining a deformed cross-sectional shape by inhibiting the cross-section from being circularized due to contraction in the discharge direction during coagulation by increasing the ratio due to the speed difference with the bath speed, or using a spinning stock solution with boric acid added Although methods for inhibiting the formation of the core structure have been studied, it was difficult to obtain a fiber having a large degree of irregularity because the fibers were distorted. In view of the above problems, an object of the present invention is to provide a PVA-based fiber having excellent mechanical properties and a high fiber cross-sectional irregularity, and an efficient method for producing the same.

[0006]

According to the present invention, a swellable layered silicate having a cation exchange capacity of 40 meq / 100 g or more is contained in an amount of 0.05% by weight or more, and a sectional circumference ratio of 0.85 or more.
Polyvinyl alcohol fiber having a diameter of a maximum inscribed circle / a minimum circumscribed circle of 0.35 or less in a cross section of the fiber and a swellable layered silicate having a cation exchange capacity of 40 meq / 100 g or more are 0.05%. % Or more, and the cross-sectional circumference ratio is 0.
A fibrous structure containing polyvinyl alcohol-based fibers having a diameter of not less than 85 and a diameter of a maximum inscribed circle / a minimum circumscribed circle of the fiber cross section of not more than 0.35, and a cation exchange capacity of 40 meq /
0.05% by weight of swellable layered silicate of 100 g or more
A fiber aggregate made of the polyvinyl alcohol-based fiber containing the above, wherein 20% or more of the fibers constituting the fiber aggregate have a cross-sectional circumference ratio of 0.85 or more and the diameter of the largest inscribed circle of the fiber cross section / A polyvinyl alcohol-based fiber aggregate having a minimum circumscribed circle diameter of 0.35 or less, wherein the fiber cross-sectional shape is different between single fibers. Alcohol spinning using a spinning solution containing a swellable layered silicate having a cation exchange capacity of 40 meq / 100 g or more with respect to the polymer and a cation exchange capacity of 0.05 wt% or more based on the polymer. The present invention relates to a method for producing a fiber.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION As the polyvinyl alcohol (PVA) polymer used in the present invention, any PVA polymer can be used.
Use of a modified PVA in which a main chain or a side chain is modified with a polymer or a monomer composed of another monomer, or a PVA-based polymer in which a syndiotactic site is contained in the same main chain, in an amount of about mol%. Can be. The average degree of polymerization of the polymer is preferably 4,000 or less from the viewpoint of handleability of the spinning stock solution for spinning and fiber properties, and is preferably about 3,000 or less,
About 0 or more is more desirable. The saponification degree is preferably 96% or more, more preferably 99% or more.

In order to increase the degree of irregularity without impairing the intrinsic properties of PVA-based fibers, a cation exchange capacity of 40 meq
/ 100 g or more of a swellable layered silicate must be blended in an amount of 0.05% by weight or more based on the PVA-based polymer.
By spinning a spinning dope containing a predetermined amount of the silicate, a PVA-based fiber having a high degree of irregularity and excellent in various performances can be produced efficiently and at low cost. That is,
When the spinning solution containing the silicate is discharged from the nozzle, P
Although VA is dehydrated in a coagulation bath, volume shrinkage occurs, but the layered silicate itself does not dissolve or shrink significantly in the coagulation bath. Therefore, if the volume shrinkage of the PVA-based polymer occurs, the dispersed phyllosilicate is also agglomerated, but if the volume is reduced to a certain volume or less, the presence of the phyllosilicate inhibits the aggregation of the PVA-based polymer. It is thought that. For this reason, the itoshino dehydrated in the coagulation bath has a non-uniform coagulation behavior occurring in the cross-sectional direction of the itoshino as compared with the case of only the PVA-based polymer, and in particular, in the present invention, the cation exchange capacity is 40 meq / Since the swellable layered silicate of 100 g or more is used, it is considered that a fiber having a large degree of irregularity in a cross section is obtained.

[0009] Even when a layered silicate having a small cation exchange capacity is used, the fiber cross section can be deformed to some extent. It is difficult to obtain fibers having a large degree of irregularity such as the diameter of the tangent circle / the diameter of the minimum circumscribed circle (tangent diameter ratio) of 0.35 or less. Not only is significantly reduced, but also the fiber properties are impaired, and the desired fibers cannot be obtained.

The swellable phyllosilicate referred to in the present invention is:
PVA solvent water, dimethyl sulfoxide (DMS
A silicate that shows swelling properties to a solution such as O), that is, the distance between layers is increased by absorbing these solvents between layers. The swellable layered silicate exhibits the property of absorbing the solvent between the layers to expand the layers or to further swell and cleave into ultrafine particles, which not only has a large deforming effect but also disperses uniformly in the fiber. Good results are obtained. When a non-swellable layered silicate is used, not only the deforming effect is hardly obtained but also the spinnability is remarkably reduced due to low dispersibility.

In order to obtain a fiber having a large degree of irregularity without substantially impairing the fiber properties, a fiber having a high cation exchange capacity (intercalating ability for intrusion of molecules and ions between layers). Having a cation exchange capacity of 40 meq / 100 g or more, preferably 50 meq / 100 g or more, and more preferably 70 meq / 100 g or more.
It is necessary to use a swellable layered silicate of q / 100 g or more. Even when a layered silicate having a small cation exchange capacity is used, the fiber cross section is deformed, but it is difficult to obtain a fiber having a large degree of deformity as in the present invention,
If a large amount of mineral is added to increase the degree of irregularity, the fiber of the present invention cannot be obtained because the fiber strength and spinnability are significantly reduced. The fiber strength is preferably at least 4 g / d, more preferably at least 5 g / d, particularly preferably at least 6 g / d. Further, since the deforming effect is high, the interlayer charge density of the layered silicate is 0.1.
It is preferably at least 25, more preferably at least 0.6, particularly preferably at least 0.9.

Cation exchange capacity 40 used in the present invention
The swellable layered silicate of meq / 100 g or more may be naturally occurring or synthesized, but the natural one generally contains impurities other than the silicate in many cases. Therefore, since the cation exchange capacity is small and it is difficult to exert the effects of the present invention, it is important to purify and use a substance having a high cation exchange capacity. Specifically, it is important to have a crystal structure of two or three layers, and to have an intercalating ability capable of inserting various molecules, ions, polymers, etc. between the layers. It is. Suitable layered silicates include layered minerals having intercalating ability and layered inorganic salts (for example, hydrotalcite, magadaite, kanemite), etc., and particularly many layered viscosity minerals are preferably used. it can. Specific layered viscosity minerals include swellable mica (mica), smectite minerals (montmorillonite, hyderite, hectorite, saponite, stevensite, etc.), vermiculite, kaolinite, halloysite, margarite, imogolite, and clint. Knight and the like. Of these, swellable synthetic fluorine mica is preferable, and a fluorinated compound obtained by heat-treating a mixture of talc and a silicide or fluoride of sodium and / or lithium is particularly preferable (Japanese Patent Application Laid-Open No. 2-149415). reference).

The composition of a preferred swellable synthetic fluoromica is as follows: αXF · β (aMgF ₂ · bMgO) · γSiO ₂ X represents sodium or lithium, α, β, γ, a and b each represent a coefficient, and 0.1 ≦ α ≦ 2, 2 ≦ β ≦ 3.
5, 3 ≦ γ ≦ 4, 0 ≦ a ≦ 1, 0 ≦ b ≦ 1, a + B = 1
It is. When swellable synthetic fluorine mica is used, spinnability is not particularly impaired, and a fiber having a larger degree of irregularity and excellent in various properties can be obtained.

The swellable layered silicate to be added to the spinning solution is finely pulverized to a side of 10 μm or less and a thickness of 0.5 μm or less, preferably 3 μm or less per side and a thickness of 0.1 μm or less. It is desirable in terms of. The method of addition is not particularly limited, but a method of first preparing a dispersion having a concentration of 5 to 150% by weight of the layered silicate and adding the necessary amount to the spinning stock solution is preferable, and a stock solution having a uniform concentration can be easily obtained. . Adding a PVA polymer to the dispersion of the layered material,
There is no problem with adjusting the spinning solution. It is also possible to add the required amount of the layered silicate powder itself to the spinning dope, but in this case, it is desirable to provide a stirrer for uniform dispersion.

The content of the swellable phyllosilicate is PVA.
0.0 based on the weight of the PVA-based polymer constituting the based fiber
It must be at least 5% by weight, preferably from 0.08 to
It is 35% by weight, particularly preferably 2 to 15% by weight. By using a swellable layered silicate excellent in deforming effect, the circumcircle diameter ratio is 0.35 or less by mixing a small amount,
Fibers having a large irregularity with a cross-sectional circumference ratio of 0.85 or more, particularly a tangent diameter ratio of 0.30 or less, and a cross-sectional circumference ratio of 0.90 or more can be obtained. The cross-sectional solidity in the fiber cross section is 70% or less,
Further, it is preferably at most 60%, particularly preferably at most 50%.

As a method for producing such a fiber, there is a method in which a spinning solution containing a polyvinyl alcohol-based polymer and a swellable layered silicate is wet-spun or dry-wet. The concentration of the PVA-based polymer in the spinning solution is not particularly limited as long as spinning is possible, but is preferably 5 to 25% by weight, particularly preferably 10 to 20% by weight. According to this method, a fiber assembly containing 20% or more of polyvinyl alcohol-based fibers having a cross-sectional circumference ratio of 0.85 or more and a diameter of the largest inscribed circle / minimum circumscribed circle of the fiber cross section of 0.35 or less. Since the cross-sectional shape of the fibers constituting the fiber assembly differs between single fibers, a fabric having a good feeling can be obtained even in the case of fabric or the like. Section circumference ratio 0.85
As described above, the ratio of the fibers having a tangent diameter ratio of 0.35 or less can be set by the amount of the swellable layered silicate and the like,
It can be 30% or more, and more preferably 50% or more, depending on the purpose and application.

The fiber assembly obtained by wet-spinning or dry-wet spinning a spinning solution containing a polyvinyl alcohol-based polymer and a swellable layered silicate has an average cross-sectional circumference ratio of 0.85 or more, and It is preferably 0.88 or more, particularly preferably 0.9 or more, and the average tangent diameter ratio is 0.35 or less, particularly 0.30 or less, and the average cross-sectional solidity is 70% or less, further 60% or less, particularly 50% or less. It is preferred that The average fiber strength of the fiber assembly is 4 g / d or more, and further 5 g / d.
/ D or more, particularly preferably 6 g / d or more. Although such fiber aggregates have different cross-sectional shapes between single fibers, the fiber strengths show almost similar values between single fibers. The values of the average cross-sectional circumference ratio and the like shown here indicate a suitable range of the fiber aggregate obtained using the spinning solution containing the swellable layered silicate. The fiber aggregate can be cut and used as a reinforcing material, or processed into a fibrous structure such as a thread (a spun yarn or the like) or a fabric (a woven or knitted fabric, a nonwoven fabric). A PVA-based fiber containing a large number of swellable layered silicates constituting a body or the like is regarded as a fiber aggregate, and the value is similarly determined. Naturally, other fibers may be used in combination with or mixed with the fiber aggregate containing the swellable layered silicate, but in this case, other than the PVA-based fibers containing the swellable layered silicate. Exclude those and calculate the value.

When the cross-sectional shape of the fiber is observed finely, when the added amount of the layered silicate is small, many are corrugated or flat, but when the added amount is increased, both ends of the flat shape are adhered. The number of hollow and Y-shaped and T-shaped members having three branches increases, and when the amount of addition is further increased, an H-shape having four branches and a multi-stem having five or more branches are obtained. A cross section is formed, and the flat shape observed at a low concentration tends to decrease. Therefore, by adjusting the addition amount of the layered substance, the behavior of solidification and the degree of irregularity can be controlled, and even when a nozzle using a round capillary is used,
Fibers with a high degree of irregularity can be obtained. In particular, when swellable synthetic fluorine mica is used, a multi-sectioned fiber is easily obtained, and a remarkable effect is obtained.

Generally, when a conventional spinning solution consisting solely of a PVA-based polymer aqueous solution is discharged from a nozzle having a round capillary and wet spinning is performed, the cross-sectional shape of the obtained yarn becomes as described above. And a cocoon-shaped section consisting of a core. On the other hand, in the present invention, when the layered substance is added to the spinning dope and the wet spinning is performed, first, the skin portion is formed in a circular shape, and then the core portion is formed by uneven solidification behavior, and the cross-sectional shape is significantly deformed. When the cross section of the obtained fiber is observed with an optical microscope, it can be observed that as the added concentration of the layered silicate increases, the skin portion gradually becomes unclear and the entire cross section becomes optically uniform.

In the following, the case of wet spinning using water as the solvent of the spinning stock solution will be described in detail as an example of the present invention. However, when the solvent is an organic solvent such as DMSO, or when the spinning method is air between the spinning nozzle coagulation baths. The same effect can be obtained in the case of a dry-wet spinning having a space (air-gap) filled with an inert gas or inert gas. First, layered silicate and PVA
A spinning dope containing the polymer is prepared as described above,
It is discharged from a nozzle into a saturated coagulation bath of inorganic salts at room temperature having dehydration ability. At this time, the nozzle to be used may be a nozzle having a circular capillary opening. However, the nozzle is not particularly limited as long as there is no major problem in spinning condition, and may be round, −, Y, +, * Nozzles having various shapes such as molds can be used.

[0021] As a substance which gives a coagulation ability to a coagulation bath,
Dehydrating salts such as sodium sulfate (Glauber's salt), ammonium sulfate, and sodium carbonate are used, and the concentration of the aqueous solution is from 100 g / l or more to a saturated concentration, and it is preferable that the concentration is as close to the saturated concentration as possible. The itoshino discharged into the coagulation bath is pulled up by a roller, but the bath draft at this time is +
200% to -120%, and + 100% to -100
%, Especially + 50% to -80%.

Further, it has been found that the addition of the layered silicate causes a specific coagulation behavior to be exhibited for Itoshino as described above, and at the same time suppresses the volume shrinkage of PVA in the coagulation bath. Was. Therefore, the bathing tension of Ishino decreases with an increase in the amount of the layered silicate added, and a larger bath draft can be obtained under the same bathing tension. Therefore, the thickness of the single fiber after bathing has been limited by the bathing tension, but according to this method, the fiber denier can be made thinner. For example, in the present invention, a capillary diameter of 0.06 to 0.02 mm can be adopted, and the bass draft at this time is reduced from -40% to +
When the content is 200%, it is possible to stably produce an ultrafine fiber having a single fiber denier of about 0.5 to 0.01 denier.
In order to obtain finer denier fibers, the amount of the layered silicate to be added to the spinning solution is 1 to 20 parts by weight, especially 3 to 20 parts by weight, based on 100 parts by weight of the discharged PVA-based polymer.
It is preferred to contain 10 parts by weight.

Thereafter, according to a standard method, each of the steps of roller stretching, wet heat stretching, drying, stretching and shrinking is carried out as required. The discharged shinoshi is still in a swollen state containing much water until it is dried. Therefore, when the roller is stretched to a high degree by the roller stretching after the bath and the subsequent wet heat stretching, the branch portions formed into irregular shapes such as the Y type and the + type are crushed on each roller by tension. Since the entire cross section may be deformed flat, the stretching ratio in a wet state before drying is 2
The stretching ratio is preferably about 8 to about 8 times, and the stretching is preferably performed so that the total stretching ratio becomes about 6 to 16 times. An ultrafine fiber having a high degree of irregularity can be obtained by stretching at a high magnification, but in this case, the degree of irregularity tends to be smaller than that of a thick denier fiber. The fiber denier may be appropriately set according to the use and purpose, but a fiber denier of about 0.01 to 100 d, particularly about 0.1 to 5 d can be used in a wide range.

In particular, a swellable silicate having a high cation exchange capacity is used in an amount of 0.1 to 100 parts by weight of the PVA-based polymer.
When a spinning dope added to about 10 parts by weight was used, a tendency was observed that stretchability was improved as compared with the case where no swellable silicate was contained. That is, the wet-spun itoshino is dried,
When the draw ratio at which the yarn breaks was measured in a drawing furnace, the draw ratio depending on the amount of the swellable silicate differs depending on the addition amount of the swellable silicate. Was improved up to about 1.5 times. The breaking stretch ratio is related to the improvement of the degree of orientation of the PVA-based polymer constituting the yarn, and is an important parameter such as improvement of fiber properties such as strength and elastic modulus and stabilization of the process during drawing.
Examination of the fiber properties of the yarn containing the layered silicate reveals that the strength and elastic modulus are increased by 10 to 30%, and that the PVA-based fiber can be made fine denier, and at the same time as having high strength and high elastic modulus. It shows the possibility that the various performances can be significantly improved.

The fiber properties of the obtained raw yarn (unacetalized yarn) were examined to find that the water resistance was lower than that of the fiber obtained without the addition of layered silicate and under the same production conditions. It turned out to be better. Specifically, when the addition of swellable synthetic fluorine mica was not added, the hot water shrinkage and the softening point in water were measured at 5% by weight and 10% by weight. The softening point in water increased to 102 ° C, 107 ° C and 110 ° C. This is probably because the layered synthetic fluorine mica exhibited an effect as a reinforcing material for the PVA-based polymer. By the way, when the longitudinal section of the original yarn to which 10% by weight of the layered synthetic fluorine mica was added was treated with a thin section and observed with a transmission electron microscope, it was confirmed that the layered material was oriented in the fiber length direction.

Since the obtained raw yarn contains the inorganic salts of the coagulation bath in itoshino, it is desirable to wash and remove it in hot water. Further, in order to improve the water resistance of Itoshino, the acetalization treatment performed on the PVA-based fiber, that is, the treatment in an aqueous solution containing an organic reducing agent such as formaldehyde that reacts with the hydroxyl group of PVA, to reduce the hydroxyl group It is also possible to make itoshino hydrophobic by blocking.

Further, it has been found that the PVA-based fiber obtained according to the present invention has excellent dyeability. PVA
Compared with other general-purpose fibers such as polyester fibers and nylon fibers, the system fibers have a higher degree of crystallinity and orientation in terms of fiber structure, and dyeability with dyes and their fastness are common. Not so expensive. In addition, cationic dyes and acid dyes cannot be dyed due to the presence of a reactive group serving as a dyeing seat in the molecular chain of the PVA-based fiber and the water resistance at the time of dyeing (under high temperature and humidity). From the above, when dyeing PVA-based fibers, direct dyes and sllen dyes are usually used, but their dyeing properties and various fastnesses are still insufficient as compared with polyester fibers and nylon fibers.

However, when the PVA fiber of the present invention containing a layered silicate is dyed, the dyeing amount,
Various robustnesses were found to be significantly improved. The reason for this is unknown, but whether the phyllosilicate has some form of binding to the dye, related to the mineral's own charge or intercalating ability, or by adding phyllosilicate. P
It is thought that a structural part capable of adsorbing and holding the dye is formed inside the VA-based fiber, and the dyeability and the fastness are improved. Further, the fiber of the present invention has a high heat resistance due to a low hot water shrinkage rate and a high softening point in water, and can be dyed at a higher temperature and for a longer time than conventional PVA-based fibers. Since the selection range of the dyes is widened, the amount of dye molecules entering the fibers can be increased (darkening).

Further, since the fiber of the present invention has an irregular cross-section, a more excellent effect can be obtained in terms of improvement of coloring properties and darkening. This is thought to lead to clear color development and darkening because light reflected on the fiber surface is irregularly reflected. In particular, since the cross-sectional shape of the PVA-based fiber of the present invention is due to the unique coagulation behavior as described above, the regularity of irregularities and the like in one fiber cross-section is poor, and the cross-section between the short fibers varies greatly. In addition, the reflection of incident light becomes more irregular, so that it is possible to improve the color developing property and enhance the deeper color.

Further, when the cross section of a conventional general PVA fiber is observed with an optical microscope, the presence of a skin portion which appears as a bright portion and a core portion which appears as a dark portion around the cross section can be confirmed. When this is dyed directly with a dye or the like, the dye is generally present in a large amount in the core portion and is dyed in a deep color, and is generally not present in the skin portion and is not dyed. For this reason, the color development of the PVA-based fiber was dull due to the skin portion, and a clear color tone was not obtained. However,
This skin / core structure is observed to become increasingly unclear as the amount of layered silicate added in the PVA fiber increases, so that the entire fiber cross section can be dyed and sharply colored It became.

As the dye that can be used, a direct dye or a slen dye conventionally used for dyeing PVA-based fibers is preferable, but other dyes such as a cationic dye or an acid dye may be used. The dyeing method may be performed by a general treatment method for each dye, and it is not necessary to adopt any particular new conditions. However, from the viewpoint of heat resistance of the PVA-based fiber under high-temperature and wet conditions,
It is desirable to perform the dyeing treatment at 100 ° C. or lower. Also,
In order to improve the dyeing properties, commonly used dyeing assistants and post-treatments for improving various fastnesses related to dyeing, for example, a fix treatment using a polyamine water-soluble resin may be performed.

According to the present invention, a fiber having an increased degree of irregularity can be produced efficiently and at low cost without impairing the intrinsic performance of PVA-based fiber. Further, the fiber of the present invention,
Can be used in any form, cut fiber
May be used, but may be used as a fibrous structure such as a yarn (filament yarn, spun yarn, etc.), a string, a cloth (woven / knitted, non-woven fabric, etc.), and mixed / used with other fibers It does not matter. The fibers that can be used in combination at this time are not particularly limited, but other PVA-based fibers containing no swellable layered silicate, polyester fibers (including wholly aromatic polyester-based fibers), polyamide-based fibers, polyolefin-based fibers, Cellulose fibers, cotton, hemp, and the like.

The fiber of the present invention can be suitably used for all purposes such as industrial use, clothing, medical use, for example, lightweight canvas,
Various filters (bag filters, filter paper, etc.), adhesive tapes
Base fabric, agricultural material paper pot, heat insulating material, highly heat-retaining clothing, moisture-permeable and water-repellent clothing, house wrapping paper,
It can be widely used for super water retention wet tissue, cleaning mop material, wiping cloth, reinforcing fiber (cement, rubber, resin, etc.). In particular, since it has a large degree of irregularity and a large specific surface area, it has excellent adhesiveness to a matrix (cement, resin, rubber, etc.), and an excellent effect as a reinforcing fiber can be obtained. Of course, it may be processed into a structure such as cloth and used as a reinforcing material. Further, when a structure such as a cloth is formed by using the fiber of the present invention, since the degree of irregularity is large and the porosity in the structure is improved, the water absorption and water divergence of water and solvent due to heat retention and capillary action are increased. In addition, since it is excellent in dyeing and weaving properties and fastness, an excellent effect for clothing can be obtained, and a remarkable effect can be obtained because it can be extremely fine.

Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited thereto.

【Example】

[Viscosity average degree of polymerization] 30 according to JIS K-6726
A certain concentration c of a diluted aqueous solution of a PVA polymer at ℃
Was measured at 5 points, and [η] = li
The intrinsic viscosity [η] is determined from m (c → 0) ηsp / c,
Further, the polymerization degree P is calculated from P = ([η] × 10 ⁴ /8.29) ^1.613 . The uncrosslinked stretched fiber of the sample was 1
The measurement is performed by dissolving under pressure with water at 140 ° C. or higher so that the concentration becomes 10 to 10 g / l. If the sample cannot be completely dissolved and a small amount of gel is generated, the gel is removed. 5
The solution was filtered through a μm glass filter, the viscosity of the filtered aqueous solution was measured, and the concentration of the aqueous solution was calculated using a correction value obtained by subtracting the residual gel weight from the sample weight.

[Cation exchange capacity (CEC) meq /
100 g] The measurement is performed by employing a method in which the method of Shomenberger ammonium acetate infiltration is reduced to one tenth. As a device, a washing liquid container graduated every 10 ml with a volume of 100 ml, a permeation tube having a length of 4 cm, a leg having a diameter of 0.3 cm, a length of 12 cm, an inner diameter of 1.3 cm, and a receiver are connected above and below. Then, the one in which the outside air is shut off and the solution permeates in a flow-down manner (FIG. 5) is used. First, a small piece of cotton wool is placed as a support layer at the bottom of the permeation tube, and filter paper pulp is packed thereon to a thickness of 5 to 10 mm to form a flat filter layer on both sides. Next, 100 ml of neutral (pH 7) 1N ammonium acetate aqueous solution is put into the purifying liquid container.
The lower end of the infiltration tube is plugged with parafilm and 2/3 of the infiltration tube
Add the same aqueous ammonium acetate solution from the washing solution container to the extent.

In this state, a fixed amount (approximately 8 to 10 g) of an analysis sample (layered clay mineral) is dropped and settled little by little so as to prevent bubbles from entering, and filled. Remove the stopper at the lower end of the permeation tube, connect it to the receiver, and start the washing by dropping the ammonium acetate solution from the washing solution container, and adjust the dripping speed so that the permeation is completed in 4 to 20 hours. After completion of the dropping of ammonium acetate, the receiver was replaced and a small amount of 8 adjusted to pH 7 with aqueous ammonia.
Wash the upper inner wall of the permeation tube with a 0% by volume aqueous ethanol solution,
50 ml of the same solution is dropped from the permeation tube to wash the analysis sample layer, and an excess ammonium acetate solution is removed. The receiver is replaced again, and the analytical sample saturated with NH ₄ ⁺ is washed by dropping 100 ml of a 10% by weight aqueous solution of potassium chloride from the washing solution container, and the adsorbed NH ₄ ⁺ is exchanged and leached. This leachate is transferred to a 200 ml volumetric flask, washed with a small amount of water, and mixed with water up to the marked line to 200 ml. A certain amount (sml) was accurately taken from this volumetric flask, and NH ₄ ⁺ was quantified by a steam distillation method.
It is calculated by the following formula as milligram equivalent per 00 g (meq). N is the normality of the NaOH standard solution,
f is the titer of the NaOH standard solution, b is the blank measurement value (m
l), t are titration values (ml) for the leachate, a is the amount of dry sample collected (g), s is the amount of extract from the leachate (g),
k is a ratio of dry sample weight / dry sample weight (dry at 105 ° C.). CEC = N × f × (bt) × (100 / a) × (20
0 / s) × k

[Cross Perimeter Ratio, Average Cross Perimeter Ratio] A fiber bundle is cut, its cross section is enlarged and photographed with an optical microscope, and then the cross section of the single fiber is about 4 to 9 cm ^2. , And then the perimeter (perimeter) L of the depiction section
Is measured using a quilvimeter or the like. Next, draw a minimum circumscribed circle (diameter B) with respect to the outer periphery of the above described descriptive cross section,
The circumference is determined, and the cross-sectional circumference ratio is calculated by the following equation. Cross-sectional circumference ratio = L / (π × B) This measurement was carried out for 20 different single fibers of the same fiber bundle. The average of the cross-sectional circumference ratios of these 20 fibers was defined as the average circumference ratio.

[Occlusal diameter ratio, average circumcircle diameter ratio] For the same single fiber whose cross-sectional circumference ratio was measured, the minimum circumscribed circle (diameter B) and the maximum inscribed circle with respect to the outer circumference of the above-described depiction cross section Draw (diameter C) and calculate by C / B. This measurement was performed for 20 different single fibers of the same fiber bundle (single fibers having the same cross-sectional circumference ratio). The average of the circumscribed diameter ratios of these 20 fibers was defined as the average circumscribed diameter ratio.

[Cross section solidity%, average cross section solidity%]
With respect to the same single fiber whose cross-sectional circumference ratio has been measured, the cross-sectional area F of the above described cross-section is determined. Next, a minimum circumscribed circle (diameter B) with respect to the outer periphery in the drawn cross section is drawn, this cross sectional area is obtained, and the degree of cross section is calculated by the following equation. Cross-sectional solidity (%) = 4F / (π × B ² ) × 100 This measurement was performed on 20 arbitrary single fibers of the same fiber bundle (single fibers having the same cross-sectional circumference ratio). Further, the average of the cross-sectional solidity of 20 of these fibers was defined as the average cross-sectional solidity.

[Fiber strength g / d] A single fiber whose temperature has been adjusted in advance is affixed to a mount so that the sample length becomes 10 cm.
C. × 60% RH for 12 hours or more, and then using a tensile tester “Instron 1122” in accordance with JIS 1-101.
The measurement is performed in accordance with No. 5, and the average number of times of measurement n ≧ 10 is shown. The denier (dr) of a single fiber is about 0.05 g / d.
Cut to a length of 90cm under r load, n ≧ 1 by weight method
The tensile test was performed using the single fiber after the denier measurement, and the strength of each single fiber was calculated in correspondence with the denier. The average is shown for 20 single fibers constituting the fiber assembly. The fiber length is short and the sample length is 10cm
If the maximum length cannot be obtained, the measurement is performed according to the above measurement conditions with the maximum length as the test length.

[Bath draft%] Calculated from the speed at which the stock spinning solution is discharged from the capillary portion of the nozzle into the coagulation bath and the first roller speed at which the yarn is removed from the bath after coagulation. Bus draft (%) = (first roller speed−discharge speed) /
Discharge speed x 100 [Hot water shrinkage%] Fiber denier is about 1000 denier
The fiber bundle is arbitrarily taken out and aligned, and a weight of 1/500 g of the fiber bundle denier is attached to one end, and the other end is fixed on a scale plate, and the length A0 of the fiber bundle is measured. This was vertically immersed in hot water at 100 ° C., immersed for 30 minutes, and then the length (A1) of the fiber bundle in the hot water was read from a scale, and A0−A1 / A0 × 100.
To calculate the contraction rate. In addition, in this example and the comparative example, the hot water shrinkage rate of the unacetalized fiber was described.

[Softening point in water ° C] Like the hot water shrinkage rate, the fiber bundle denier is arbitrarily taken out so that the denier becomes about 1000 deniers, aligned and then 1/500 of the fiber bundle denier.
g is attached at one end, and the other end is fixed on the scale plate.
This is vertically immersed in a pressurizable glass tube containing water at normal temperature. Thereafter, the water temperature is raised from room temperature at a rate of 1 ° C. for about one minute, and the temperature at which the fiber bundle contracts by 10% or melts is measured. In this example and the comparative example, the hot water shrinkage of the unacetalized fiber is described. [Distribution% of original yarn cross-sectional shape] The cross-section of the fiber assembly was taken in a micrograph, and the cross-sectional shape of any 40 fibers was observed and classified.

[Layered Clay Mineral (Swellable Synthetic Fluorine Mica)] A talc having a composition formula of Mg ₃ Si ₄ O ₁₀ (OH) ₂ and sodium silicate fluoride (Na ₂ SiF ₆ ) are obtained by heat treatment. Synthesized swellable fluoromica (manufactured by Corp Chemical Co., Ltd., “Sofushima” ME-100, NaMg _2.5
Si ₄ O ₁₀ F ₂ ) was used. The layer charge density was 1, the cation exchange capacity was 80 meq / 100 g, and the average particle size was 6 μm.

[Dyeing ratio%] The dyeing solution before and after dyeing is diluted with water, and the absorbance of the diluted aqueous solution is measured by a spectrophotometer (C
-2000 type Hitachi Color Analyzer-), and the dyeing rate was determined by the following equation. Dyeing ratio (%) = (AB) / A × 100 where A is the absorbance at the maximum absorption wavelength of the diluted dye aqueous solution before dyeing, B is the absorbance at the maximum absorption wavelength of the diluted dye aqueous solution after dyeing, A and B had the same absorption wavelength.

[Coloring K / S] The reflectance of the dyed raw cotton at the maximum absorption wavelength was measured with a spectrophotometer (C-2000 type Hitachi Color Analyzer). It was calculated by the equation. K / S = (1−R) ² / 2R where R represents the reflectance at the maximum absorption wavelength of the dyed raw cotton. [Washing fastness class] It was evaluated by the A-2 method of JIS-L-0844. That is, the discoloration and discoloration of the sample raw cotton due to the washing treatment, and at the same time, the degree of contamination of the washed cotton / rayon white cloth,
And the degree of contamination of the washing liquid is indicated by 5 grades of 1 to 5 grades, respectively. The higher the grade, the higher the robustness.

[Wet friction fastness class] JIS-L-08
It was evaluated by the 49 gakushin method. Indicated by 1st to 5th grade. A higher rating indicates a higher robustness. [Light fastness class] Evaluated by the third exposure method of JIS-L-0841. That is, the sample was transferred to a carbon arc screen.
Exposure was carried out for a predetermined time by a dometer, and the degree of discoloration was indicated by a blue scale. A higher rating indicates a higher robustness.

Examples 1 to 5 and Comparative Example 1 A synthetic swellable fluoromica was wet-pulverized to a particle size of about 1 μm to obtain a 7% by weight aqueous dispersion.
0.1 part by weight (Example 1), 1 part by weight (Example 2), 3 parts by weight (Example 3), 5 parts by weight (Example 1), 100 parts by weight of 9 mol% of PVA Example 4) The fluoromica aqueous dispersion was added so as to be 10 parts by weight (Example 5) and 0 parts by weight (Comparative Example 1), and PVA was added.
An aqueous solution having an A concentration of 16% by weight was prepared and used as a spinning dope.
This spinning stock solution was discharged from a round capillary having a diameter of 0.08 mm and a nozzle having 2,000 holes into a saturated sodium sulfate bath at room temperature by a -60% bath draft to form a thread.

Thereafter, the bath was separated at a roller speed of 6 m / min, and after stretching the roller 2.5 times, the concentration of sodium sulfate was 350 g / l.
The film was stretched by 1.5 times in wet heat at 90 ° C. in a bath. After further drying, stretching is performed so that the total stretching ratio becomes 10 times, and
% Shrinkage treatment and wound up. 10 g of the obtained spun yarn is shackled, immersed in an aqueous solution of 30 g / l of formaldehyde, 270 g / d of sulfuric acid, and 150 g / l of sodium sulfate for 20 minutes, washed with water and dried to obtain an acetate.
Was performed. The results are shown in Tables 1 and 2. Note that A in the table indicates that among 20 arbitrary fibers, the cross-sectional solidity is 0.85 or more,
It shows the ratio (%) occupied by fibers having a tangent ratio of 0.35 or less.

Example 6 An aqueous dispersion of fluorine mica was added to 30 parts by weight of synthetic swellable fluorine mica with respect to 100 parts by weight of PVA, and an aqueous solution of 12% by weight of PVA was prepared as a spinning solution. After stretching so that the total stretching ratio was 8 times, the same procedure as in Example 1 was carried out except that a treatment was performed at a shrinkage ratio of 5%. The results are shown in Tables 1 and 2. Comparative Example 2 Non-swelling muscovite (cation exchange capacity: 0 meq / 100 g) was wet-pulverized to a particle size of about 2 μm or less to obtain P having a polymerization degree of 1750 and a saponification degree of 99.9 mol%.
A raw spun yarn was obtained in the same manner as in Example 4 except that an aqueous solution having a PVA concentration of 16% by weight was prepared and used as a spinning dope in addition to 5 parts by weight with respect to 100 parts by weight of VA.
The results are shown in Tables 1 and 2.

[Embodiments 7 and 8] 0.07 mm in diameter
-30% (Example 7), + 40% from a nozzle having 6000 holes to a saturated sodium sulfate bath at room temperature from a nozzle having 6000 holes
The same procedure as in Example 4 was carried out except that the yarn was formed by discharging with the bath draft of Example 8 and then stretched to a total draw ratio of 9 and then subjected to a 5% shrinkage treatment. A spun yarn was produced. 10 g of the obtained yarn is shackled, formaldehyde 30 g / l, sulfuric acid 270 g / l, sodium sulfate 15 g / l
It was dipped in an aqueous solution of 0 g / l at 70 ° C. for 20 minutes, washed with water and dried to perform an acetalization treatment. The results are shown in Tables 3 and 4.

Comparative Example 3 A round capillary having a diameter of 0.07 mm and a nozzle having 6000 holes were discharged into a saturated sodium sulfate bath at room temperature by a + 40% bath draft to form a thread. After stretching to 9 times, 5
The same procedure as in Comparative Example 1 was carried out except that the shrinkage treatment was carried out to produce a spun yarn. However, the yarn could not be pulled out stably from the nozzle portion, and the yarn was broken in the stretching step, and the sample could not be collected.

[Comparative Example 4 and Comparative Example 5]
For PVA having a saponification degree of 99.9 mol%, boric acid 1.5
% By weight, and 0.3% by weight of acetic acid.
An aqueous solution having a concentration of 16.5% by weight was prepared and used as a spinning dope.
30 g of caustic soda was fed from a nozzle having a round capillary having a diameter of 0.08 mm and a number of holes of 1000 with this spinning stock solution.
In a coagulation bath at 80 ° C. of 340 g / l and Glauber's salt 340 g / l, the discharge amount was changed so that the bath draft became −80% (Comparative Example 4) and −60% (Comparative Example 5). Formed. After that, the shinosino was separated from the coagulation bath, roll-stretched 2.5 times, neutralized, and concentrated at a sodium sulfate concentration of 350 g / l.
Stretched by 2 times wet heat in a bath at 0 ° C, and residual boric acid was 0.3% by weight.
/ PVA. Further, a convergence process is performed to make the total stretching ratio 7 times in a wet state, and after drying, the total stretching ratio 2
The film was stretched so as to be 0 times, subjected to a shrinkage treatment of 2%, and wound up. The cross section of the fiber was almost elliptical, and the modified cross-section fiber of the present invention could not be obtained. The results are shown in Tables 3 and 4.

Example 9 About 1 swellable synthetic fluoromica was used.
After wet pulverization to a particle size of μm to obtain a 7% by weight aqueous dispersion, PV having a polymerization degree of 1750 and a saponification degree of 99.9 mol% was obtained.
Aqueous fluorine mica dispersion was added so as to be 5 parts by weight with respect to 100 parts by weight of A, and an aqueous solution having a PVA concentration of 14% by weight was prepared as a spinning dope. This spinning dope is used for a diameter of 0.0
Same as Example 4 except that a 6 mm round capillary, a nozzle having 6000 holes, was discharged into a saturated sodium sulfate bath at room temperature by a + 50% bath draft to form a shinoshi, and the total stretching ratio was 8 times. I went to. The results are shown in Tables 3 and 4.

[Example 10] Hydrophilic synthetic smectite ("Lucentite SW" manufactured by Corp Chemical Co., Ltd.)
N ", interlayer charge density 0.33, cation exchange capacity 101
An aqueous dispersion containing 2% by weight of meq / 100 g and an average particle size of 52 nm was subjected to PVA (polymerization degree 1750, saponification degree 99.
(9 mol%) Synthetic smectite was dissolved in 100 parts by weight so as to be 5 parts by weight, and the same procedure was performed as in Example 1 except that an aqueous solution having a PVA concentration of 16% by weight was used as a spinning solution. As compared with the case of using the swellable synthetic fluoromica, the degree of irregularity was small and the number of polyhedral cross sections was small, but good results were obtained. The results are shown in Tables 3 and 4.

[Examples 11 to 14, Comparative Examples 6 and 7] Each of the acetalized raw yarns obtained in Examples 4, 6 and Comparative Example 1 was made into a 20 g shackle shape for dyeing. Sample raw cotton and direct dye (Sumitomo Chemical Co., Ltd., "sumilight Vi
olet BB ”) An aqueous solution in which 2% owf and 15.0% owf were dissolved was adjusted to 70 ° C. or 90 ° C. to prepare a dye bath. The sample raw cotton is put in 1000 cc of this dyeing bath, and the bath ratio is 1: 5.
After dyeing treatment for 60 minutes, the raw cotton was washed with water. Then
Excess dye was removed from the raw cotton by immersing it in a 60 ° C. aqueous solution containing 1 g / l of the detergent “Amilazine D” for 20 minutes and dried (soaping treatment). Table 5 shows the dyeability of the obtained raw cotton.
Shown in

Examples 15 and 16 and Comparative Example 8 Each of the acetalized raw yarns obtained in Examples 4 and 6 and Comparative Example 1 was dyed by binding 20 g of each yarn. The sample raw cotton is used as sllen dye (Mikethren Chemical Co., Ltd., “Mikethren
e Brill Blue R ") 2% owf and 30% by weight of caustic
Aqueous solution 22 cc / l, sodium hydrosulfite (Na ₂ S ₂ O ₄ ) 6 g / l, dextrin 2 g / l
And adjusted to a dyeing bath at 80 ° C. This dyeing bath 1000c
c. Put the raw cotton wool into the bath at a bath ratio of 1:50.
After dyeing for 1 minute, the raw cotton was washed with water. Thereafter, it was immersed in an 80 ° C. aqueous solution containing 2 g / l of detergent “Marcel soap” and 0.5 cc / l of hydrogen peroxide solution for 20 minutes to remove excess dye from the raw cotton and dried (soaping treatment). Table 5 shows the dyeability of the obtained raw cotton.

Examples 17 to 20, Comparative Example 9 Each of the acetalized raw yarns obtained in Examples 3, 4, 6, 7 and Comparative Example 1 was dyed by binding 20 g each of the yarns. Sample raw cotton for direct dyeing (Sumitomo Chemical Co., Ltd., “Sumilight
Violet BB ") An aqueous solution in which 1.7% owf and 8% owf dissolved in Glauber's salt was adjusted to 70 ° C to prepare a dye bath. Dyeing bath 1000
Sample raw cotton was put into cc to make a bath ratio of 1:50, and after dyeing treatment for 60 minutes, the raw cotton was washed with water. Next, the dye was immersed in a 60 ° C. aqueous solution containing 1 g / l of the detergent “Amilazine D” for 20 minutes to remove the excess dye from the raw cotton and dried (soaping treatment).

[Examples 21 to 24, Comparative Example 10] Each of the acetalized raw yarns obtained in Examples 3, 4, 6, 7 and Comparative Example 1 was made into a 20 g shackle shape for dyeing. The sample raw cotton is used as sllen dye (Mikethren Chemical Co., Ltd., “Mikethren
e Gold Orange G ") A dye bath at room temperature was adjusted with 2% owf. A sample raw cotton is put in 1000 cc of this dyeing bath, and a bath ratio of 1:
After treating at room temperature for 15 minutes, 22 cc / l of a 30% by weight aqueous solution of caustic soda was added, followed by treatment for 5 minutes, and then sodium hydrosulfite (Na ₂ S).
₂ g / l of ₂ O ₄ ) was added and treated for 5 minutes, and then 2 g of sodium hydrosulfite (Na ₂ S ₂ O ₄ )
/ L and the dyeing bath is treated at 60 ° C. for 60 minutes,
The raw cotton was washed with water. Next, detergent "Marcel soap" 2 g / l
The excess dye was removed from the raw cotton by immersing it in a 60 ° C. aqueous solution containing for 30 minutes and dried (soaping treatment). Table 6 shows the results.

[0059]

[Table 1]

[0060]

[Table 2]

[0061]

[Table 3]

[0062]

[Table 4]

[0063]

[Table 5]

[0064]

[Table 6]

[Brief description of the drawings]

FIG. 1 shows a non-acetater of the present invention obtained by Example 3.
5 is a photomicrograph of a cross section of a lubricated PVA-based fiber.

FIG. 2 shows a non-acetator of the present invention obtained by Example 4.
5 is a photomicrograph of a cross section of a lubricated PVA-based fiber.

FIG. 3 shows a non-acetator of the present invention obtained by Example 5.
5 is a photomicrograph of a cross section of a lubricated PVA-based fiber.

FIG. 4 is a photomicrograph of a cross section of a non-acetalized PVA-based fiber having a conventional cocoon-shaped cross section obtained in Comparative Example 1.

FIG. 5 is a schematic diagram showing an apparatus used for measuring a cation exchange capacity (CEC).

Claims (4)

[Claims] 1. Cation exchange capacity 40 meq / 100 g
Polyvinyl containing the above swellable layered silicate in an amount of 0.05% by weight or more, a cross-sectional circumference ratio of 0.85 or more, and a diameter of a maximum inscribed circle / minimum circumscribed circle of a fiber cross section of 0.35 or less. Alcohol-based fiber. 2. Cation exchange capacity 40 meq / 100 g
Polyvinyl containing the above swellable layered silicate in an amount of 0.05% by weight or more, a cross-sectional circumference ratio of 0.85 or more, and a diameter of a maximum inscribed circle / minimum circumscribed circle of a fiber cross section of 0.35 or less. A fiber structure containing alcohol-based fibers. 3. Cation exchange capacity 40 meq / 100 g
A fiber aggregate comprising polyvinyl alcohol-based fibers containing 0.05% by weight or more of the above-mentioned swellable layered silicate, wherein 20% or more of the fibers constituting the fiber aggregate have a cross-sectional circumference ratio of 0%. A polyvinyl alcohol-based fiber having a diameter of not less than 85 and a diameter of a maximum inscribed circle / a diameter of a minimum circumscribed circle of the fiber cross section of 0.35 or less, characterized in that the fiber cross section is different between single fibers. Polyvinyl alcohol fiber aggregate. 4. A spinning dope containing a polyvinyl alcohol-based polymer and a swellable layered silicate having a cation exchange capacity of 40 meq / 100 g or more in an amount of 0.05% by weight or more based on the polymer. A method for producing a polyvinyl alcohol-based fiber to be spun.