JPH10168755A - Finishing agent for fiber - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject finishing agent, feedable to a spinning process or a nonwoven process with slight trouble and capable of imparting the smoothness and antistatic properties by including an alkylimidazolium ethosulfate and a sorbitan ester of a fatty acid in a specific proportion therein. SOLUTION: This finishing agent for a polyvinyl alcohol-based fiber consists essentially of (A) an alkylimidazolium ethosulfate represented by formula I (R1 is a 10-30C alkyl) and (B) a sorbitan ester of a fatty acid represented by formula II (R2 is a 10-30C alkyl) such as sorbitan monooleate at (30/70) to (80/20) ratio of the components A to B. The polyvinyl alcohol-based fiber is preferably treated with the finishing agent for the polyvinyl alcohol-based fiber to impart the coherency thereto.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a finishing agent for polyvinyl alcohol-based fibers, in particular, a finishing agent for polyvinyl alcohol-based fibers having excellent water solubility (hereinafter abbreviated as PVA fiber) and PVA to which the finishing agent is applied. About fibers.

[0002]

2. Description of the Related Art Conventionally, as a method for obtaining PVA fiber, a method of dissolving polyvinyl alcohol (hereinafter abbreviated as PVA) in water and discharging the solution into an aqueous solution or air to solidify it is generally performed. . PVA fibers obtained by these methods are called water-based PVA fibers because water is used as a solvent for the spinning dope, and these fibers are hardly soluble or insoluble in water at low or normal temperatures. Generally, an oil agent or a finishing agent (hereinafter collectively referred to as a finishing agent) is applied to the fiber surface for the purpose of improving the processability during spinning and the texture of the fiber. ing.
It is generally practiced to apply a finishing agent to the PVA fibers as well, and these PVA fibers are hardly soluble or unnecessary in water. It is usually prepared and applied in a dispersed form.

[0003] As an alternative to the conventional water-based PVA fiber, a method for obtaining PVA fiber using an organic solvent instead of water has been recently researched and developed, and a technique for obtaining water-soluble PVA fiber using an organic solvent has been proposed. Has also been proposed.
For example, JP-A-7-90714 discloses that PVA soluble in water at 100 ° C. or lower is dissolved in an organic solvent represented by dimethyl sulfoxide, and the resulting spinning solution is wet-spun in an organic coagulation solution such as methanol or acetone. Alternatively, a water-soluble PVA fiber having excellent dimensional stability even under high humidity can be obtained by dry-wet spinning, wet-drawing, extracting and removing the undiluted solvent from the fiber, drying and heat-shrinking the fiber. Have been described.

When such a method using an organic solvent is used, a PVA fiber can be obtained without contact with water.
A fiber can be obtained. Such fibers are then spun into a water-soluble spun yarn, for example, or used in the form of a water-soluble nonwoven fabric through a carding process. Alternatively, a water-soluble woven fabric, a water-soluble knitted fabric, or a water-soluble nonwoven fabric obtained from these fibers may be used as a base fabric of a chemical lace.

[0005]

However, all of the conventional finishes have been developed and used for PVA fibers which are hardly soluble or insoluble in water at ordinary temperature or low temperature. Cannot be used for PVA fibers of This is because the conventional finish is applied as an aqueous solution or an aqueous dispersion, and a part or all of the water-soluble fiber to which the finish is applied is dissolved in the applied finish. Attempts have been made to dissolve or disperse the main components of the currently used finishing agents in organic solvents (solvents that do not dissolve easily water-soluble PVA fibers) instead of water, and to apply the finishing agents. Unfortunately, as it is, it has been found that a solvent that does not dissolve the water-soluble PVA fiber has insufficient solubility and cannot be used.

The finishing agent used for the conventional PVA fiber obtained from an aqueous system is insufficient in terms of antistatic property and smoothness, and the obtained fiber is slightly easily charged and has creaking. Due to the large size (because the smoothness is small), there is a problem that the passability of a processing step for a card or the like is not sufficient. Therefore, there is a strong demand for improvements in finishing agents including these improvements. As described above, the present invention is to develop a novel finishing agent capable of imparting excellent antistatic properties and smoothness to extremely water-soluble PVA fibers, whereby new spun yarns and nonwoven fabrics can be produced. It is intended for development.

[0007]

Means for Solving the Problems The inventors of the present invention have intensively studied the development of a novel finishing agent with the aim of solving these problems. It is possible to apply a finishing agent to PVA fiber which is easily soluble in water, without dissolving or partially dissolving the PVA fiber, without impairing the fiber properties, and using the conventional finish. Develop new finishing agent and PVA fiber to which the finishing agent is applied, which is excellent in antistatic property and excellent in smoothness even more than the agent, and can be supplied with less trouble to the spinning process and the non-woven fabric process including the card. did.

Specifically, the present invention mainly comprises (A) an alkyl imidazolium ethosulfate and (B) a sorbitan fatty acid ester, and a weight ratio of (A) to (B) is 30 /.
A finishing agent for polyvinyl alcohol-based fiber having a ratio of 70 to 80/20 and a PVA fiber provided with such a finishing agent. In particular, the PVA fiber of the present invention has a water dissolution temperature of 100
It is below ° C. Various finishing agents have been conventionally known as finishing agents for PVA fibers, and the present invention is directed to a combination of the above-mentioned compounds (A) and (B) in a specific amount among these known finishing agents. Has been found to exhibit a remarkably excellent effect, especially in the case of water-soluble PVA fibers, the fibers are hardly dissolved or swelling and sticking by being applied, and the applied finishing agent Excellent effects can be obtained.

Hereinafter, the present invention will be described in detail. First, (A) alkyl imidazolium ethosulfate constituting the finish of the present invention is a compound represented by the following structural formula (1), and is a component which is mainly effective for improving antistatic properties.

[0010]

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In the formula (1), R ₁ represents an alkyl group having 10 to 30 carbon atoms, particularly those having 15 to 22 carbon atoms. The chemical properties of the alkyl imidazolium ethosulfate represented by the general formula (1) are slightly acidic, have good heat resistance, and are quasi-negative by Kawai method for skin damage. More preferred specific compounds include stearyl imidazolium ethosulfate and palmitin imidazolium ethosulfate.

The (B) sorbitan fatty acid ester (also referred to as sorbitan ester) used in combination with the compound of the above general formula (1) is a compound represented by the following structural formula (2), and mainly has a fiber bunching property. It is a compound that is effective for improving the friction and the friction between the fiber and the metal.

[0013]

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In the above formula, R ₂ represents an alkyl group having 10 to 30 carbon atoms, and particularly those having 15 to 22 carbon atoms are suitable. The chemical properties of the compound represented by the compound (2) are neutral, excellent in heat resistance, and skin damage is quasi-negative by Kawai method. Monoesters are more preferable compounds, and sorbitan monooleate and sorbitan monolinoleate are particularly preferable.

As described above, it is necessary to use both of these components in combination with the physical properties of the fiber.
By using (A) and (B) together, (A) and (B)
Has improved compatibility, and as a result, the stability as a finishing agent is improved, long-term storage is possible, and further, it is possible to prevent the finishing agent from being denatured during use, and (A) and (B) Coexistence makes it possible to keep the solution viscosity low, excellent in handleability, and to adhere the fiber to the fiber in a very uniform film form. As described above, the ratio of (A) / (B) is 30/70 to 80/20 by weight. Outside this range, the synergistic effect of using both (A) and (B) is reduced, and if the ratio of (A) is less than 30/70, static electricity is likely to be generated, and
If the ratio of (A) is larger than 20, the thermal stability and the like in the production process decrease. In general, better results can be obtained by increasing the proportion of alkyl imidazolium ethosulfate having a high antistatic effect. More preferably, (A) / (B) is 40
/ 60 to 65/35.

In addition to these components (A) and (B), various other compounds which do not adversely affect the basic physical properties can be added and used. Compounds that can be used in combination include, for example, alkylamide compounds such as oleic acid diethanolamide, which have excellent antistatic properties and focusing properties, and polyoxyethylene nonylphenyl ether compounds that improve slickness, focusing properties, and metal friction resistance. It is. These compounds are used in an amount of 0 to 3 based on the total amount of (A) and (B).
It can be added at a ratio of about 0% by weight.

The finishing agent of the present invention can be made into an aqueous solution. However, when the fiber to be applied is an easily water-soluble PVA fiber, it is dissolved in a non-aqueous solvent which does not dissolve the fiber at the application temperature. Alternatively, it is necessary to apply in a dispersed state or as a finish component. Above all, a method of dissolving in a non-aqueous solvent is preferable. As a solvent used in this method, the finish component of the present invention is dissolved, and the water-soluble PVA fiber is not dissolved or the fiber properties are not deteriorated, and Anything that is safe can be used. Examples of solvents that can be used safely include lower monoalcohols such as methanol and ethanol, polyhydric alcohols such as ethylene glycol, propylene glycol, hexamethylenediol, and glycerin, polyoxyethylene lauryl ether, and polyoxyethylene octyl ether. Such as polyoxyethylene compounds and ether compounds thereof, ethylene glycol monoethyl ether,
Examples include ethylene glycol monobutyl ether. Particularly, the above-mentioned polyhydric alcohols are preferable. A small amount of water can be added to these, to such an extent that the fibers are not affected. The amount of the solvent used is 10 to 200% by weight based on the total weight of the above (A) and (B).

The finishing agent of the present invention is applied to PVA fibers in a required amount. Specifically, the range is preferably 0.1 to 3% by weight based on the weight of the fiber. Also, from the standpoint of raw cotton production, considering the conditions and method of application, it is desirable that the finishing agent be applied to the entire fiber as much as possible after the application process. , Heat treatment, or an aging step to make the application uniform. In the present invention, in order to omit the steps after the application as much as possible, it is desirable to provide the application before the dry heat stretching.
Therefore, the higher the concentration of the finish, the better the result. This is because the time and effort for removing the solvent used for dilution in a subsequent step can be reduced. Therefore, the solution containing the finish is usually heated to a temperature above room temperature and below the boiling point of the solvent. This temperature is determined depending on the viscosity of the solution containing the finishing agent, the handling property in the process, and the like, but it is usually 300 centipoise or less, preferably 100 centipoise or less.

As a method of applying the method, a method of attaching a finishing agent to a rotating roller and continuously touching the running yarn, a method of passing the yarn through a chamber in which the finishing agent is sprayed, and the like. Various methods can be used, but the method of applying with a rotating roller is the simplest. An object of the present invention is to obtain a PVA fiber provided with 0.1 to 3% by weight of a finishing agent mainly composed of alkyl imidazolium ethosulfate and sorbitan fatty acid ester. The adhering amount of the finishing agent is suitably from 0.1 to 3% by weight, preferably from 0.2 to 1% by weight, whereby a fiber having desired excellent physical properties can be obtained. If the amount of adhesion is small, there is a problem particularly in the antistatic property, and if it is too large, it causes troubles such as winding in the card process.

The PVA fiber to which the finishing agent is applied is preferably one having a degree of polymerization of 500 to 5,000. In particular, in the case of a water-soluble PVA fiber, the degree of polymerization is 700 to 2,500.
Having a saponification degree of 80 to 98 mol% is preferred. From such PVA, a water-soluble fiber having a dissolution temperature in water of 100 ° C. or less can be obtained, and among them, P having a saponification degree of 80 to 96 mol% is obtained.
From VA, water-soluble PVA fibers having a dissolution temperature in water of 60 ° C. or less particularly suitable for the present invention are obtained, and such low-temperature water-soluble PVA fibers are particularly preferred. Of course, modified copolymer units other than vinyl alcohol units and vinyl acetate units may be introduced into PVA, and specific examples thereof include ethylene, allyl alcohol, itaconic acid, acrylic acid, maleic anhydride, vinyl pivalate, And vinylpyrrolidone. The ratio of these modified copolymer units is 20
It is preferably at most mol%. The PVA fibers may contain polymers other than PVA, and these polymers are preferably water-soluble polymers.

The PVA fiber which is the object of the present invention is prepared by dissolving the above-mentioned PVA in an organic solvent such as dimethyl sulfoxide, dimethylacetamide, dimethylformamide, glycerin, ethylene glycol and the like, and having a PVA concentration of 6 to 6;
The spinning solution is 0% by weight. The spinning solution is discharged into a coagulation bath to form fibers. The undiluted solution temperature at the time of discharging is preferably 40 to 170 ° C. The spinning method may be a wet spinning method or a dry-wet spinning method. Coagulation baths include methanol, ethanol, acetone, methyl ethyl ketone,
Examples include methyl isobutyl ketone, methyl acetate, benzene, toluene and the like. A solvent of the stock solution may be added to these coagulation baths. The temperature of the coagulation bath is -20 to 20
20 ° C. is preferred. The obtained fiber is preferably subjected to wet stretching by 2 to 8 times. After wet drawing, the PVA fiber is immersed in a solidification bath to remove as much of the stock solution solvent contained in the fiber as possible, and the fiber is dried. If necessary, dry heat stretching or heat treatment may be performed. By the above method, a water-soluble PVA fiber suitable for the present invention is obtained.

The fiber obtained in this manner is at 20 ° C. ×
The specific resistance at 45% RH is 9 × 10 ⁹ or less, which is on the order of 10 ⁸ under appropriate conditions. Usually 20 ° C x 6
Under the 5% RH condition, an order of 10 ⁸ or less is maintained.
The amount of static electricity generated during the card process is 20 ° C x 45% R.
-0.3 KV or more under H condition,-
0.1 KV or more can be maintained. Many of the conventional finishing agents for PVA fibers have an order of 10 ⁸ or more at 20 ° C. × 45% RH, and the static electricity in the card process is −0.1 KV.
Was less than. The finish of the present invention has a greater effect when applied to easily water-soluble fibers. However, this effect is applicable not only to easily water-soluble fibers, but also to general vinylon fibers, and can be widely used as a general-purpose finish.

[0023]

EXAMPLES The present invention will be described below with reference to examples. In Examples,% is a value based on weight unless otherwise specified. In addition, the dissolution temperature in water referred to in the present invention means that a 2 mg / d load is suspended on a fiber having a test length of 4 cm, and the fiber is immersed in water at 0 ° C.
This refers to the temperature at which the fibers melt when water is heated at a rate of 2 ° C./min.

Examples 1 to 4 Partially saponified PV having a degree of polymerization of 1370 and a degree of saponification of 93.6%
A dissolved in dimethyl sulfoxide, PVA concentration 26%
Was obtained. This spinning dope was kept at 90 ° C. and wet-spun into a coagulation bath of methanol / dimethylsulfoxide = 75/25 at 3 ° C. through a nozzle having 400 holes and a hole diameter of 0.08 mm. The film was stretched 6-fold in a wet stretching bath at 40 ° C. consisting of sulfoxide = 96/4, and further brought into countercurrent contact with heated methanol to completely extract and remove dimethyl sulfoxide. Twenty of the spun yarns are bundled, and a finishing agent solution having various compositions shown in Table 1 is dissolved in ethylene glycol to give a finishing agent concentration of 80% and a viscosity of 90 centipoise at 60 ° C. Was applied so that the amount of adhesion (final content of the finishing agent) had the value shown in Table 1, and the obtained fiber was subjected to dry heat drawing at 140 ° C. and 170 ° C. in two stages and a total draw ratio of 2 times.
Shrinkage treatment was performed in a hot blast stove consisting of two sections at 0 ° C and 180 ° C. A shrinkage treatment with a total shrinkage of 25% was performed.
The dissolution temperature of the obtained fiber in water was 23 ° C. After the drawn yarn was further bundled, it was mechanically crimped to obtain a crimped fiber. This crimped fiber was placed on a small roller card, and various process characteristics were measured. The results are summarized in Table 1.

Comparative Examples 1 and 2 Various crimped fibers were obtained in the same manner as in the above Examples, except that the finishing agents were changed to the compounds shown in Table 1. Table 1 shows the results. Both have high specific resistance,
Focusing was also a step forward.

[0026]

[Table 1]

Examples 5 to 6 and Comparative Examples 3 to 4 The same procedure as in the above example was carried out except that the ratio of (A) alkyl imidazolium ethosulfate and sorbitan monooleate was changed as shown in Table 2, A compressed fiber was obtained. Table 2 shows the results.

[0028]

[Table 2]

[0029]

The finishing agent of the present invention, when applied to a water-soluble PVA fiber, imparts excellent antistatic properties and convergence without impairing the fiber performance, and thus requires a spinning or carding process. In the manufacturing process of the nonwoven fabric to be performed, excellent processability can be given. Further, the PVA fiber obtained in the present invention has excellent water-solubility and passability through a processing step as compared with conventional water-based PVA fiber, and thus is useful for producing good products at low cost.

Claims (3)

[Claims] 1. A composition comprising (A) an alkyl imidazolium ethosulfate and (B) a sorbitan fatty acid ester, wherein the weight ratio of (A) to (B) is 30/70 to 80/20.
Finishing agent for polyvinyl alcohol-based fibers. 2. A polyvinyl alcohol fiber to which the finishing agent according to claim 1 is provided. 3. The fiber according to claim 2, wherein the dissolution temperature of the polyvinyl alcohol fiber in water is 100 ° C. or lower.