JPH08113859A - Nonwoven fabric comprising antistatic network structure fiber and its production - Google Patents

Abstract

PURPOSE: To obtain nonwoven fabric comprising network fibers having excellent antistatic properties and tenacity and improved handle, by wholly and thermally bonding a web prepared by subjecting a mixed solution of at least an ethylene vinyl alcohol-based polymer and an ester-based polymer to flash spinning. CONSTITUTION: An ester-based polymer obtained by subjecting an adduct of bisphenol A with ethylene oxide to block copolymerization is mixed with an ethylene vinyl alcohol-based polymer and a polyethylene terephthalate and dissolved in methylene chloride as a solvent within 90 minutes dissolution time to give a uniform spinning solution having 5-30wt.% polymer concentration. The solution is subjected to flash spinning at 160-220 deg.C and piled on a net conveyor to form a web of three-dimensional network structure composed of the adduct of bisphenol A with ethylene oxide amounting to 0.3-35wt.% of constituent fibers. Then the web is wholly and thermally bonded by a thermal calendering roll to give nonwoven fabric comprising antistatic network structure fibers.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a nonwoven fabric composed of fibers having an antistatic ultrafine mesh structure and a method for producing the same.

[0002]

2. Description of the Related Art Conventionally, as a method for producing a non-woven fabric having ultrafine fibers as constituent fibers, the non-woven fabric obtained by a spunbond method using a modified nozzle is subjected to a mechanical process or high-pressure water flow to break the constituent fibers. Known methods include a method of fiberizing, a so-called melt blown method in which a molten polymer is extruded from a spinning nozzle, and drawn and thinned by a heated fluid. However, in the method using the odd-shaped nozzle, the nozzle cost becomes high and the process becomes complicated. Although the melt blown method can surely obtain extremely fine fibers, it has the drawbacks that stretchability and crystallization are small and the strength of the obtained nonwoven fabric is extremely low because the fibers are thinned at the stage of the molten polymer.

On the other hand, there is a so-called flash spinning method as a method for obtaining a nonwoven fabric made of ultrafine fibers from a solution spinning state. The flash spinning method is, as described in US Pat. No. 30,815,19, a solution of a low-boiling solvent and a polymer is extruded from a spinning nozzle and the solvent is instantaneously vaporized. However, since the non-woven fabric obtained by this formulation is composed of a single polymer component for all the materials, there are inherent disadvantages of the polymer, and there is a problem that the application of the product is limited. For example, an olefin polymer is excellent in lightness, but has a low modulus and a unique slimy feel. The ester-based polymer is originally a polymer suitable for high-strength fiber formation and has a high modulus, but it has not been put into practical use because a high-strength nonwoven fabric has not been obtained under flash spinning. Further, since these non-woven fabrics do not have antistatic property, they are electrically charged and various troubles occur when they are used as they are.

Regarding the antistatic non-woven fabric which copes with the obstacle due to this electrification, in a general melt spinning method, a polyalkylene oxide component is blended into the fiber to provide a durable antistatic property. It is known to be the best for obtaining electric yarn. However, an attempt by the solution spinning method such as the flash spinning method for the antistatic nonwoven fabric was made by the present inventors in Japanese Patent Application Nos. 6-071180 and 6-07.
There is only 1177 and Japanese Patent Application No. 6-071178. In other cases, it is general to apply an antistatic agent as an auxiliary process after forming fibers into a cloth to impart antistatic property. However, due to the increase in incidental processing costs,
There is a problem in that the antistatic agent is peeled off from the cloth, and the antistatic performance deteriorates with the lapse of use, so that the antistatic agent does not have durability.

[0005]

DISCLOSURE OF THE INVENTION The present invention is intended to solve the above-mentioned problems and to provide a non-woven fabric composed of ultrafine antistatic network-structured fibers having improved antistatic performance as compared with conventional ones. is there.

[0006]

The present inventors have arrived at the present invention as a result of extensive studies to solve the above problems. That is, the present invention is characterized in that (1) a web of fibers having a three-dimensional network structure composed of mixed fibers composed of at least an ethylene vinyl alcohol polymer and an ester polymer is heat-bonded over the entire surface. And (2) at least an ethylene vinyl alcohol-based polymer and an ester-based polymer are mixed to form a spinning mixed solution of this mixture and a solvent, and thereafter, the mixture is spontaneously grown. Flash spinning from a pressure or higher to a temperature and pressure range substantially lower than that, and at the time of this flash spinning, the concentration of the polymer in the spinning mixed solution is 5 to 30% by weight, and the spinning temperature is 160-2
A method for producing a non-woven fabric composed of antistatic reticulated structure fibers, characterized in that the temperature is 20 ° C., the dissolution time of the polymer is within 90 minutes, and the resulting web is heat-bonded over the entire surface. Is.

According to the present invention, the ethylene vinyl alcohol-based copolymer improves hydrophilicity, so that antistatic property is imparted. Furthermore, when the ester-based polymer is a block copolymerized ester containing a polyalkylene oxide component, a very good antistatic effect is exhibited due to the hydrophilic properties of these two polymers.

Next, the present invention will be described in detail. The non-woven fabric composed of the network structure fibers referred to in the present invention is 0.01 to 10
A fibril fiber corresponding to μm consists of a fiber group in a three-dimensional reticulated state and is endlessly configured in the longitudinal direction of the yarn, and this fiber group is a non-woven fabric to which the entire surface is heat-bonded.

An ethylene vinyl alcohol polymer is required as one of the fiber components constituting the nonwoven fabric of the present invention. The ethylene vinyl alcohol-based polymer refers to a crystalline polymer composed of a known random copolymer of ethylene and vinyl alcohol. The amount of the copolymerization is not particularly limited, but it is preferable that the proportion of the repeating unit composed of ethylene is 20 to 70 mol%. The remainder is preferably vinyl alcohol alone, but may be composed of repeating units of vinyl alcohol and other vinyl monomers. The proportion of the repeating unit composed of ethylene is more preferably 30 to 50 mol%. When the proportion of ethylene units in the copolymer is less than 20 mol%,
That is, when the proportion of vinyl alcohol units is more than 80 mol%, the resulting nonwoven fabric lacks flexibility. On the other hand, when the proportion of ethylene units exceeds 70 mol%, the proportion of vinyl alcohol units, that is, hydroxyl groups is inevitably small, and the affinity of the nonwoven fabric for water is lowered. The ethylene vinyl alcohol-based polymer can be obtained by saponifying the vinyl acetate portion, and the saponification degree in that case is preferably about 95% or more. When the saponification degree is low, the crystallinity of the copolymer is lowered, so that the copolymer is likely to be softened, which causes a trouble in the subsequent heat bonding step. As the ethylene vinyl alcohol-based copolymer, it is usually preferable to use one having a number average molecular weight of about 8,000 to 30,000.

Examples of the ester polymer include polyethylene terephthalate and polybutylene terephthalate. Furthermore, with these as the main components, isophthalic acid,
Phthalic acid, glutaric acid, adipic acid, sulfoisophthalic acid, diethylene glycol, propylene glycol,
Those containing 1,4-butanediol, 2,2-bis (4-hydroxyethoxyphenyl) propane, etc. in the range of up to 40 mol% as a copolymerization component may be equivalently used. The viscosity in this case is such that the relative viscosity ηrel measured at a mixing ratio of tetrachloroethane and phenol of 1/1 (weight ratio), 20 ° C. and a concentration of 0.5% by weight is 1.3 to 1.
It can be applied from fiber grade of about 6 to high viscosity resin (relative viscosity 1.7) produced by solid state polymerization. The higher the viscosity of the polymer, the higher the strength of the nonwoven fabric, which is in a preferable direction.

Among the ester-based polymers constituting the fiber of the present invention, the use of a block copolymer ester containing a polyalkylene oxide component may further enhance the antistatic effect. In this case, the polyalkylene oxide component-containing block copolymerized ester is polyethylene oxide,
It means a block copolymer containing a polyalkylene oxide component such as polypropylene oxide or ethylene oxide-propylene oxide copolymer. In particular,
Preferred is one obtained by adding a polyalkylene oxide compound having one or more (preferably two) ester functional groups such as a hydrosyl group, a carboxyl group, an alkoxycarbonyl group, and an amino group when synthesizing a polyester. is there. Specific examples of the component forming the polyester include dicarboxylic acid components such as sebacic acid, terephthalic acid, isophthalic acid, phthalic acid, glutaric acid, adipic acid, 5-sodium sulfoisophthalic acid, and naphthalic acid,
Examples include diol components such as ethylene glycol, diethylene glycol, propylene glycol, 1,4-butanediol, neopentyl glycol, 1,4-cyclohexanedimethanol and xylylene glycol.
The polyalkylene oxide component has a molecular weight of 400 to 20,000, preferably 800 to 10,000, and the content in the polyalkylene oxide component-containing block copolymer ester is 10 to 90% by weight, preferably 20 to 70% by weight. % Is good.

As the polyalkylene oxide, a modified polyalkylene oxide such as bisphenol A,
A compound obtained by adding an alkylene oxide to bisphenols such as bisphenol S is preferable from the viewpoint of improving heat resistance and antistatic property. Further, as a polyester-forming component, 5-alkali metal sulfoisophthalic acid, N,
The use of a hydrophilic component such as N'-bis (amino-n-propyl) piperazine, or the incorporation of an organic or inorganic electrolyte or other ionic compound into the block copolymer can improve the antistatic activity of the block copolymer. It has the advantage of increasing the amount, and is particularly preferable.

In the nonwoven fabric according to the present invention, the proportion of the polyalkylene oxide component in the constituent fibers is preferably 0 to 35% by weight, and when the proportion is 0.3 to 35% by weight, the antistatic performance is improved. It is more preferable because it can be caused. Most preferred is 2 to 25% by weight.

If it exceeds 35% by weight, the antistatic performance is sufficiently satisfied, but the strength of the nonwoven fabric is lowered and the heat resistance is also lowered, which is not preferable. Further, when the block copolymerized ester containing a large amount of polyalkylene oxide component is polymerized and discharged, it becomes difficult to solidify the strand by cooling, and it may not be possible to cut into pellets, which makes it impossible to apply the polymer as it is. Problems also arise. In addition, if a recipe for mixing and diluting another crystalline polymer is adopted, the mixing ratio of the ethylene vinyl alcohol-based polymer is reduced and the characteristics of the polymer are lost, which is not preferable. That is, when the mixing ratio of the ethylene vinyl alcohol-based polymer is small, the lightness and the strength of the nonwoven fabric are deteriorated.

On the other hand, the proportion of polyalkylene oxide is 0.
Even if it is in weight%, the ethylene vinyl alcohol polymer has antistatic properties, so there is no problem with antistatic properties when it is used as a nonwoven fabric, but if more antistatic properties are required, polyalkylene oxide should be mixed. Is preferred.

The polyalkylene oxide component in the constituent fibers is present if the fibers are dyed with osmic acid, the polyethylene terephthalate portion is dissolved with o-chlorophenol, and then taken with an electron microscope at a magnification of 60,000. Can be confirmed.

The mixing ratio of the ethylene vinyl alcohol polymer and the ester polymer is not particularly limited, but the ethylene vinyl alcohol polymer / ester polymer is 1/99 to 99/1% by weight. Is preferred. Further, mixing at least an ethylene vinyl alcohol-based polymer and an ester-based polymer means that a crystalline polymer other than these may be contained. In that case, the ethylene vinyl alcohol-based polymer and the ester-based polymer may be mixed and added within any range as long as the individual characteristics of the polymer are not changed.

The nonwoven fabric of the present invention is one in which at least the above-mentioned ethylene vinyl alcohol-based polymer and ester-based polymer are mixed in the constituent fibers, and these are basically incompatible with each other. Therefore, fibrillation can be promoted. This incompatibility with each other means that the mixed polymer components are present independently and thus have the essential fiber properties of the individual polymers. Generally, it is known that mixed fibers of polymers which are incompatible with each other are easily divided into their components by physical force, so that the fibers constituting the nonwoven fabric are compatible with each other in the present invention. Therefore, the fibril fibers of extremely fine polymer alone are mainly constituted.

Next, a typical method for producing a nonwoven fabric made of the network-structured fiber of the present invention will be described. But,
It goes without saying that the nonwoven fabric of the present invention can be manufactured by other methods.

In order to produce the nonwoven fabric of the present invention, a generally known flash spinning method can be applied. That is, a mixed polymer of an ethylene vinyl alcohol-based polymer and an ester-based polymer is not dissolved in any of these polymers at a low temperature, and a solvent that dissolves under a high temperature and a high pressure is used to Dissolve under high temperature and high pressure to form one bath phase. Then, the polymer and the solvent are phase-separated, spun out from a nozzle, formed into a web, and then heat-bonded on the entire surface, whereby it can be produced.

Examples of the solvent include generally known aromatic hydrocarbons such as benzene and toluene, aliphatic hydrocarbons such as butane, pentane and isomers and homologs thereof, and alicyclic hydrocarbons such as cyclohexane. Unsaturated hydrocarbons, halogenated hydrocarbons such as trichloromethane, methylene chloride, carbon tetrachloride, chloroform, 1,1
-Dichloro-2,2-difluoroethane, 1,2-dichloro-1,1-difluoroethane, methyl chloride, ethyl chloride, etc., alcohols, ethers, ketones, nitriles, amides, fluorocarbons, and these And a mixture of the above solvents. In recent years, the use of solvents that deplete the ozone layer must be avoided as global environmental issues have been clamored for. Including this environmental problem, preferred solvents for the present invention include methylene chloride, 1,1-dichloro-2,2-difluoroethane, 1,2-dichloro-
1,1-difluoroethane and the like can be mentioned.

The concentration range of the polymer cannot be unconditionally limited depending on the degree of polymerization of the polymer, the kind of the solvent and the pressurized state, but in the present invention, the polymer concentration in the spinning mixed solution is 5 to 30% by weight. It is necessary to be. When the concentration of the polymer is less than 5% by weight, it is difficult to obtain continuous long fibers. On the other hand, if it exceeds 30% by weight, it becomes a tubular fiber which is not fibrillated and contains bubbles, and the ultrafine high-strength fibril reticulated fiber cannot be obtained, resulting in a non-woven fabric having an extremely poor texture.

The solvent concentration is preferably 70 to 95% by weight. When the solvent concentration is less than 70% by weight, the viscosity of the spinning mixed solution becomes too high and the dissolution of the polymer is less likely to be uniform, so that ultrafine fibril fibers are not formed,
The fibers tend to have cavities. On the other hand, if it exceeds 95% by weight, the net-structured fibers made of fibril fibers do not become continuous and, as a result, the strength of the resulting nonwoven fabric becomes low, which is not preferable.

The proportion of the polyalkylene oxide component in the mixed polymer is preferably adjusted to be 0 to 35% by weight, and the proportion of 0.3 to 35% by weight improves the antistatic performance. It is more preferable because it is obtained. Most preferred is 2 to 25% by weight.

If it exceeds 35% by weight, the antistatic property is sufficiently satisfied, but the strength is lowered and the heat resistance is lowered, which is not preferable. When applying a polymer containing a large amount of polyalkylene oxide component as it is, when the polyalkylene oxide component-containing block copolymerized ester is polymerized and discharged, it becomes difficult to solidify the strand by cooling, which makes it impossible to cut pellets. Occurs.
Furthermore, the performance of the three-dimensional reticulated fiber is deteriorated and the cost is increased, which is not preferable. In addition, if a recipe for mixing and diluting another crystalline polymer is adopted, the mixing ratio of the ethylene vinyl alcohol-based polymer is reduced, the spinnability is lowered, and the characteristics of the polymer are lost. Absent.

It is very desirable to add and inject nitrogen, such as an inert gas, carbon dioxide, before or after preparing the spinning mixed solution in order to increase the spinning pressure. In particular, the addition of an inert gas before the temperature rise prevents the deterioration of the polymer, promotes the temperature rise property, promotes the solubility of the polymer in a solvent, improves the productivity of extremely fine fibril network fibers, etc. Which results in a non-woven fabric with a very good texture.

In producing the network-structured fibers constituting the nonwoven fabric of the present invention, the stretching and orientation of the fibers are made by the explosive force associated with the vaporization of the solvent, and the strength of the nonwoven fabric and the fibers is that the fibers are sufficiently stretched and oriented. It is often determined by whether or not This explosive force is the vaporization force due to the instantaneous speed, and the solvent vaporizes at once in a time of 0.1 seconds or less, and in the process, the concentration of the polymer increases in the short time, and finally the mixture is mixed. Only the polymer precipitates. The mixed polymer precipitated by vaporization of the solvent is cooled to form ultrafine fibers. This cooling process is most important for the tenacity of the fibers and the non-woven fabric, and in order to obtain the fibers and the non-woven fabric of high tenacity, the cooling by the flash flow and the stretching orientation depending on the speed must be sufficiently performed. In the present invention, since the ethylene vinyl alcohol-based polymer and the ester-based polymer are not compatible with each other and are composed of mixed fibers thereof, the fibrillation is sufficiently promoted by this flush flow. Thus, extremely fine fibril fibers can be formed, and thus a nonwoven fabric having an extremely good texture can be obtained.

In the production of the non-woven fabric of the present invention, since the constituent fibers are made of polymers having no compatibility with each other, the polymers are easily separated from each other even if the polymers are dissolved in the solvent. Is preferably added. This surface-active agent is effective for keeping the spinning mixed solution stable in an emulsified state, and generally, a nonionic surface-active agent can be applied. Examples thereof include monoesters of lauric acid, stearic acid and oleic acid, and polyoxyethylene adducts of lauryl alcohol, stearyl alcohol and oleyl alcohol. The more uniform the mixed solution, the more a non-woven fabric composed of extremely fine fibril network fibers can be obtained.

The melting and spinning temperatures of the spinning mixture for obtaining the fibers constituting the nonwoven fabric of the present invention must be 160 to 220 ° C. In particular, the block copolymerized ester containing a polyalkylene oxide component has a large decrease in viscosity in the presence of a solvent, and the polyalkylene oxide component is easily eluted in the solvent. Therefore, if the temperature exceeds 220 ° C., the fibers may be colored or the decomposition may be promoted, so that a nonwoven fabric having high strength and antistatic property may not be obtained. Also,
If it is less than 160 ° C., it does not become ultrafine fibril fiber, but becomes tubular fiber having a hollow portion.

In general, the dissolution time of a polymer in flash spinning cannot be unconditionally defined because of the balance with the above-mentioned dissolution and spinning temperature. That is, when the temperature is high, the dissolution time needs to be as short as possible, and when the temperature is relatively low, the dissolution time may be long.

The dissolution time of the spinning mixture for obtaining the nonwoven fabric of the present invention must be 90 minutes or less and as short as possible. If it exceeds 90 minutes, the polyalkylene oxide component-containing block copolymer ester may be colored or thermally decomposed, or the strength of the nonwoven fabric may be reduced. Further, if the dissolution time is too short, the dissolution of the polymer becomes insufficient, which may cause a problem of clogging in the filter and a problem in producing a nonwoven fabric having a uniform fiber and a good texture. Not good because there is.

The pressure during spinning of the mixed solution in which the polymer is dissolved is not limited to any particular value depending on the amount of the solvent, the concentration of the polymer and the amount of the inert gas added, but is usually preferably 40 kg / cm ² or more. If it is less than 40 kg / cm ² , the explosive force at the time of flash spinning is lowered, the orientation of the fibers is lowered, and high tenacity fibers cannot be obtained. In addition, the discharge becomes uneven,
There arises a problem that it becomes impossible to spin out fibers in a stable high fibril state. The upper limit pressure is not particularly limited, but is 12 from the viewpoint of suppressing the decrease in the viscosity of the polymer.
0 kg / cm ² is preferred.

In carrying out flash spinning, the spinning mixture solution is flash-spun from a pressure of autogenous pressure or higher to a temperature and pressure region substantially lower than that through a pressure drop chamber. A generally known nozzle can be applied to the spinning nozzle.

In the polymer or the spinning mixed solution, a matting agent, a lightproofing agent, a heatproofing agent, a pigment, an opening agent, a weatherproofing agent, a UV absorber, a heat storage agent, and a stabilizer which are usually used for fibers are used. Etc., if the effect of the present invention is not impaired,
Can be added.

Next, a description of making a non-woven fabric will be added.
The non-woven fabric of the present invention can be obtained by using the reticulated fiber obtained by the above method as a web and thermally adhering it over the entire surface. The specific method is explained below,
It is not limited to this.

That is, an extremely fine reticulated fiber is spun in the horizontal direction from the nozzle, and this fiber is hit against a rotating plate rotated by a motor at a position horizontally separated from the tip of the nozzle by about 30 mm and traversed. The web is formed on the net conveyor installed directly below the rotating plate while performing the width setting. Then, after that, the entire surface of the web is heat-bonded.

Examples of the method for heat-bonding the entire surface include, for example, a calendering method in which a resin roll is temporarily pressed and then heat-bonding is performed using a calendering roll, a method in which a cotton roll is wound around a calendering roll,
There is a multi-stage calendering method in which several calender rolls are combined and gradually bonded. However, it is not limited to these.

As an example, when the embossing method is used,
The use temperature is preferably (melting point of low melting point polymer of fiber components constituting the nonwoven fabric −40 ° C.) or higher and lower than or equal to the melting point. If the temperature is lower than (melting point of low-melting polymer −40 ° C.), adhesive strength is poor,
The resulting non-woven fabric has many fluffs and has extremely low strength. On the other hand, if the temperature exceeds the melting point,
The nonwoven fabric is colored or formed into a film, which is not preferable as a product.

The linear pressure at that time is 1.0 to 10 kg / c.
m is preferred. If it is less than 1.0 kg / cm, there is a problem that the fibers constituting the obtained nonwoven fabric are poorly adhered to each other and the surface of the nonwoven fabric is fluffy or cannot be formed into a nonwoven fabric. On the other hand, if it exceeds 10 kg / cm, film formation occurs and the nonwoven fabric becomes inferior, which is not preferable.

[0040]

According to the present invention, it is possible to obtain a non-woven fabric using a fiber having a reticulated structure composed of at least an ethylene vinyl alcohol polymer and an ester polymer, and having an extremely high degree of ultrafine fibril fiber. This non-woven fabric is superior to conventional products in antistatic performance and has high strength. Therefore, it is suitable for use in floppy disk sleeves, bags, synthetic paper, house wraps and the like. Further, since it contains an ester polymer, it has a great effect that not only coloring with a pigment but also appropriate dyeing in a later step can be performed.

[0041]

EXAMPLES Next, the present invention will be specifically described based on Examples. In addition, measurement and evaluation of various characteristics in the following examples were performed by the following methods. Melt index value: ASTM D 1238
The measurement was carried out at a temperature of 210 ° C. according to the method described in (E). -Melting point of polymer: The temperature that gives the extreme value of the melting absorption curve measured at a temperature rising rate of 20 ° C / min using a differential scanning calorimeter DSC-2 type manufactured by Perkin Elmer was taken as the melting point.・ Specific surface area of non-woven fabric: "BELSO" manufactured by Nippon Bell Co., Ltd.
The specific surface area of the fiber was measured by the BET nitrogen adsorption method using "RP28" and determined in m ² / g. -Apparent density of non-woven fabric: sample width 10 cm, sample length 10 c
After preparing a total of 5 sample pieces of m and measuring the basis weight of each sample, a load of 4.5 g / cm ² is applied for 10 seconds using a thickness measuring instrument manufactured by Daiei Kagaku Seiki Seisakusho. Measure the thickness after leaving, calculate the apparent density by the following formula,
The average value was used as the apparent density of the nonwoven fabric.

Apparent density (g / cm ³ ) = Basis weight (g / m ² ) / Thickness (mm) / 1000-Strength and elongation of nonwoven fabric: Tensilon UTM-4-1-100 manufactured by Toyo Baldwin Co., Ltd. JISL 109
According to the strip method described in 6 above, 10 sample pieces having a sample length of 20 cm and a sample width of 5 cm were prepared, and the gripping interval was 10 c.
The maximum strength and the elongation were measured under the conditions of m and a pulling speed of 10 cm / min, and the average value was converted into a basis weight of 100 g / m ² for evaluation. Tear strength of non-woven fabric: Measured using an Elmendorf type tear strength tester according to the Pendulum method described in JIS L 1096. -Moisture permeability of nonwoven fabric: According to JIS L 1099-A-1, moisture permeability (g / m ² / h) under the conditions of temperature 40 ° C and humidity 90%.
r) was measured. -Antistatic property: in accordance with JIS L 1094 A method, 4.
Prepare 5 pieces of 5 cm x 4.5 cm sample piece and
After pre-drying for 20 hours, 20 ° C. × 40% R. H. The sample was adjusted by leaving it at room temperature for one day. Then, it was attached to a static Honest meter, the half-life time (second) was measured under the following conditions, and the average value was shown.

Discharge voltage between electrodes: 10000 V Distance between electrodes: 20 mm for receiving electricity, 20 mm for discharging Turntable rotation speed: 1730 rpm Discharging time: 30 seconds ・ Dyeing property of nonwoven fabric: After the following dispersion dyeing, reduction dyeing was performed, and further After washing with water and drying, the following evaluation was made.

◎ Extremely good ○ Good △
Somewhat good × poor ・ Dispersion dyeing: Disperse dye Blue E-FBL (Sumitomo Chemical Co., Ltd.) 1% owf, Dispersant Disper-TL (Meisei Chemical Co., Ltd.) 1 g / liter, formic acid 0.1 g as an auxiliary agent
/ L, bath ratio 1:50, and boil-dyed for 60 minutes. -Reduction dyeing: 1 mol / liter of Sanmor FL-100 (manufactured by Nichika Chemical Co., Ltd.) as a refining agent, 2 g / liter of hydrosulfite, 1 g / liter of caustic soda, and a bath ratio of 1:50 at 80 ° C for 20 minutes. Processed. Example 1 64 parts by weight of an oligomer (number average degree of polymerization: 4) obtained by an esterification reaction of terephthalic acid and ethylene glycol, 33 parts by weight of an ethylene oxide adduct of bisphenol [A] (average molecular weight: 6000), 3 parts by weight of bisethylene glycol ester of sodium sulfoisophthalic acid and 0.02 parts by weight of antimony trioxide (used as a 2% solution of ethylene glycol) were charged into a reactor, and the conditions were 0.1 ton, 270 ° C. and 4 hours. Was polycondensed to obtain a block copolymer.

With this block copolymer, the repeating unit of ethylene is 44 mol%, the saponification degree is 98%, the melting point is 165 ° C., the density is 1.14 g / cm ³ , and the melt index value is 13 g / 10 minutes. Ethylene vinyl alcohol polymer, melting point 256 ℃, the mixing ratio of tetrachloroethane and phenol is 1/1 (weight ratio), 20 ℃
And the relative viscosity ηrel measured at a concentration of 0.5% is 1.38.
Polyethylene terephthalate which was No. 3 and 300 g of methylene chloride as a solvent were charged into a 500 cc autoclave. Further, as a surface active agent, polyoxyethylene 3 mol% of lauryl ether and tridecyl stearate were added in an amount of 0.2% by weight to the mixed polymer.

After closing the autoclave, nitrogen was injected into the autoclave so as to have a pressure of 50 kg / cm ² , stirring was started at an appropriate speed, and heating was started. The solution concentration of each component was such that the polymer concentration was 18% by weight and the solvent concentration was 82% by weight. The polymer ratio of each component is
Ethylene vinyl alcohol polymer / block copolymer / polyethylene terephthalate = 40/30/30
% By weight. This composition corresponds to a proportion of polyalkylene oxide component in the polymer of about 10% by weight.

It took 25 minutes to reach the temperature of 180 ° C. after reaching the temperature of 80 ° C., and stirring was continued for 10 minutes after reaching the temperature of 180 ° C. to obtain a uniform solution. The dissolution time at this time was 35 minutes. The pressure showed a gauge pressure of 95 kg / cm ² .

Immediately after opening the valve, it was spun into the atmosphere through a nozzle having a pressure drop chamber and a hole diameter of 0.75 mmφ and L / D = 1. The pressure in the pressure drop chamber is 85 kg / cm.
^{Was 2} .

Subsequently, the spun fiber was applied to a rotary plate to form a non-woven web on a net conveyor, which was then calendered with a calender roll having a temperature of 120 ° C. and a linear pressure of 1.5 kg / cm to obtain 50 g / m ^2. A corresponding non-woven fabric was created. When the antistatic performance of this non-woven fabric was investigated, it was found that the half-life was 15 seconds and the antistatic performance was sufficient. Even when this non-woven fabric was repeatedly washed 10 times in home laundry, there was almost no change in antistatic performance. When this non-woven fabric was dyed with a disperse dye, it was also confirmed that clear dyeing was possible. Other properties of this non-woven fabric are shown below.

Apparent density: 0.40 g / cm ³ Specific surface area: 31 m ² / g KGSM Strength (MD / CD): 38.8 / 39.4 kg / 5 cm Width elongation (MD / CD): 18/21% Tear Strength (MD / CD): 0.7 / 0.5 kg Moisture vapor transmission rate: 250 g / m ² / hr Examples 2 to 5, Comparative Examples 1 to 4 In Example 1, the polymer concentration and the solvent concentration in the solution, The polymer ratio of each component and the ratio of the polyalkylene oxide component in the polymer were changed to the conditions shown in Table 1. Otherwise, flash spinning was performed under the same conditions as in Example 1 to obtain a nonwoven fabric. Table 1 shows the results.

[0051]

[Table 1]

In Examples 2 to 5, the non-woven fabrics obtained were not colored, had a good texture, and were satisfactory in both strength and tear strength. Subsequently, when the antistatic performance of this non-woven fabric was investigated, it was found that Examples 2 to 5 have sufficient antistatic performance. These non-woven fabrics are
Even after repeatedly washing 10 times with the Mulandry, there was almost no change in the antistatic performance. When this non-woven fabric was dyed with a disperse dye, it was confirmed that it could be dyed clearly.

In Comparative Example 1, since the constituent fibers were only the ethylene vinyl alcohol polymer, there was no dyeing property and the tenacity was slightly inferior. In Comparative Example 2, since the constituent fibers were only polyester, no antistatic property was observed. In Comparative Example 3, since the polymer concentration in the solution was too low, short fibers containing powdery fibers were formed, and a nonwoven fabric of long fibers could not be obtained.
In Comparative Example 4, the concentration of the polymer in the solution was too high, the solution viscosity increased, and the fiber did not become a three-dimensional reticulated fiber, but a fiber having a tubular shape, and only a non-woven fabric having an extremely poor texture was formed. Could not be manufactured. Examples 6 to 7 and Comparative Examples 5 to 7 In Example 1, the spinning temperature and the dissolution time were changed to the conditions shown in Table 2. The other conditions are the same as in Example 1,
A flash-spun nonwoven fabric was obtained. The results are shown in Table 2.

[0054]

[Table 2]

In Examples 6 and 7, the obtained non-woven fabric was not colored and was satisfactory in both strength and tear strength. Then, when the antistatic performance of the Korira non-woven fabric was investigated, it was found that it had a sufficient antistatic performance. Even when this non-woven fabric was repeatedly washed with a homeland 10 times, there was almost no change in antistatic performance. When this non-woven fabric was dyed with a disperse dye, it was confirmed that it could be dyed clearly.

In Comparative Example 5, since the spinning temperature was too low, the polymer was not dissolved and spinning was not possible. Comparative Example 6
In the above, since the spinning temperature was too high, the polymer used was colored and decomposed, and the target non-woven fabric composed of three-dimensional reticulated fibers could not be obtained. In Comparative Example 7, the dissolution time of the polymer was too long, so that the copolymer ester mainly containing the polyalkylene oxide component was decomposed to give a strange odor and only a colored nonwoven fabric was obtained. The non-woven fabric had a strong decrease in strength and could not be used. Examples 8 to 9 Table 3 shows the calendering temperature and the linear pressure in Example 1.
The condition was changed to. A flash spun nonwoven fabric was obtained under the same conditions as in Example 1 except for the above. Table 3 shows the results. In Examples 8 and 9, there was no coloring, and the strength and antistatic property were sufficiently satisfactory.

[0057]

[Table 3]

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Claims (3)

[Claims] 1. A static electricity preventing characterized in that a web of fibers having a three-dimensional network structure and comprising a mixed fiber composed of at least an ethylene vinyl alcohol polymer and an ester polymer is heat-bonded over the entire surface. A non-woven fabric made of natural reticulated structure fibers. 2. The ester-based polymer is a block copolymerized ester containing a polyalkylene oxide component, and the proportion of the polyalkylene oxide component in the constituent fibers is 0.3 to 35.
The non-woven fabric made of the antistatic network-structured fiber according to claim 1, wherein the non-woven fabric has a weight%. 3. At least an ethylene vinyl alcohol-based polymer and an ester-based polymer are mixed to form a spinning mixed solution of this mixture and a solvent, and thereafter, a self-generated pressure or a pressure higher than that is applied thereto. Is flash-spun to a substantially low temperature and pressure region, and during this flash-spinning, the concentration of the polymer in the spinning mixed solution is 5 to 30% by weight, the spinning temperature is 160 to 220 ° C., and the dissolution time of the polymer is For 90 minutes or less, and further, heat-bonding the obtained web over the entire surface thereof, the method for producing a non-woven fabric comprising antistatic network-structured fibers.