KR20160115422A - Method of manufacturing superabsorbent yarn - Google Patents

Abstract

According to the present invention, a high absorbent monomer mixed liquid including an ionic bond cross-linking agent is applied to a yarn, the yarn is heat-treated, and thus the monomer mixed liquid is polymerized and crosslink-reacted to manufacture a high absorptive yarn. According to the present invention, an ionic bond cross-linking agent is contained in the high absorbent monomer mixed liquid to significantly improve the adhesive strength between a yarn and a high absorbent monomer mixed liquid. Therefore, when the yarn passing through a guide during a manufacturing process, a coating layer of a high absorbent monomer mixed liquid with which the yarn is applied (coated) is effectively prevented from being separated, thereby further improving absorbent properties of a high absorptive yarn. According to the present invention, as a coating liquid for applying high absorbent properties, a high absorbent monomer mixture including an ionic bond cross-linking agent instead of a conventional polymerized polymer dispersion liquid or an aqueous solution is used to simplify a manufacturing process and to make manufacturing cost effective. In addition, according to the present invention, due to a reaction heat generated when a monomer inside the high absorbent monomer mixture is polymerized and cross-linked in a heat treatment process, the drying speed is increased to improve productivity.

Description

TECHNICAL FIELD The present invention relates to a method of manufacturing a superabsorbent yarn,

More specifically, the present invention relates to a method for producing a superabsorbent yarn, which comprises applying a mixture of a superabsorbent monomer containing an ionic crosslinking agent to a yarn and then subjecting the resultant mixture to heat treatment to polymerize and crosslink the superabsorbent monomer mixture, By manufacturing a superabsorbent yarn by a method of forming a coating layer, it is possible to improve adhesion between a yarn and the coating layer to prevent peeling of the coating layer coated on the yarn during a production process, thereby improving water absorption, Absorbent yarn in which the production cost is low and the productivity is improved due to the rapid drying rate due to the heat of reaction during polymerization and crosslinking reaction.

Recent rapid development of information and telecommunication has demanded the development of new design and performance of optical cable along with increase of demand of optical cable. One of them is to block the water penetrating into the optical cable. The optical cable is buried mainly in the underground, and a gap is formed in the plastic insulator surrounding the outer portion of the optical cable due to the impact or force exerted from the outside, thereby causing the problem that the surrounding water penetrates into the optical cable. Such water intrusion results in short-circuiting between the wires resulting in damage to the optical cable. When such a problem occurs, the damaged part of the cable must be found and then replaced. However, since the optical cable is installed underground, or placed under water where a large amount of water such as sea or river is placed along the water, The work is time consuming and costly. One way to effectively prevent this is to coat the outside of the wire with a superabsorbent polymer so that the infiltrated water is absorbed from the outside of the wire to enhance the function of protecting the wire. Currently, the method of applying the superabsorbent polymer is very diverse, ranging from sprinkling the superabsorbent polymer particles onto the cable to winding the cable with a tape coated with a superabsorbent polymer.

Highly absorptive yarns coated with a superabsorbent material on aramid fibers can be used in the manufacture of optical communication cables, which in this case act as reinforcing members and water blocking members.

As one of the methods for producing the superabsorbent yarn, there is a method in which a water-insoluble superabsorbent material dispersed in water is impregnated in a yarn and then a drying process is performed. However, according to this method, it is impossible to produce a yarn having satisfactory absorbency due to impregnation property deterioration due to high viscosity.

Methods for improving impregnability are disclosed in U.S. Patent No. 5,635,569 and U.S. Patent No. 5,264,251. According to this method, a yarn coated with a superabsorbent material is prepared by impregnating a yarn in a water-in-oil emulsion containing a superabsorbent material in an aqueous phase and then performing a drying process. However, this method also has serious drawbacks. That is, since the environment-causing substances such as isohexadecane are released during the drying process, additional equipment and costs are required for the treatment of such harmful substances.

In order to solve the above problems, U.S. Patent Nos. 5,100,397, 6,319,558, and 6,284,367 disclose a method of coating an aqueous solution comprising a water-soluble crosslinkable polymer on a substrate, And the water-soluble polymer is crosslinked through a heat treatment process after impregnation to convert it into a water-insoluble superabsorbent material.

This method requires that the yarn be subjected to a high temperature heat treatment process for a long time in order to crosslink the water-insoluble polymer, which is not crosslinked at all, to a degree sufficient to form a water-insoluble substance having a high level of water absorbency. However, when a high-temperature heat treatment is performed for a long time, damage to the yarn is caused, which causes a decrease in the strength and elongation of the yarn. Decreasing the strength and elongation of the yarn used as the reinforcing material of the optical cable is fatal. Further, as the heat treatment time of the high temperature becomes longer, the productivity is lowered and the energy use is increased, which is economically disadvantageous.

The object of the present invention is to solve the problems of the prior arts described above and to solve the problems of the prior arts so that the drying speed of the absorbent material applied to the yarn is increased to improve the productivity, the manufacturing process is simplified, the manufacturing cost is low, And a method of manufacturing a highly absorbent seal capable of effectively preventing peeling of a coating layer.

In order to achieve the above objects, the present invention uses a superabsorbent monomer mixture containing an ionic crosslinking agent instead of the conventional polymeric polymer dispersion or aqueous solution as a material for imparting water absorbency.

Specifically, in the present invention, a superabsorbent yarn is produced by applying a mixture of a superabsorbent monomer to a yarn and then heat-treating the mixture to polymerize and cross-link the superabsorbent monomer mixture.

The present invention uses a highly water-absorbing monomer mixture instead of the polymeric polymer dispersion or aqueous solution in the prior art, thereby simplifying the manufacturing process and reducing the manufacturing cost.

In addition, since the ionic crosslinking agent is contained in the mixture of the superabsorbent monomers, the adhesion between the coating layer of the mixture of superabsorbent monomers coated on the yarn and the yarn is improved, thereby effectively preventing the separation of the yarn and the coating layer So that the absorbency is improved.

In addition, the present invention improves the productivity by increasing the drying speed due to the heat of reaction occurring when the monomers in the superabsorbent monomer mixture are polymerized and crosslinked in the heat treatment step.

Hereinafter, a method for producing a superabsorbent chamber according to the present invention will be described in detail.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit and scope of the invention. Therefore, the present invention encompasses all changes and modifications that come within the scope of the invention as defined in the appended claims and equivalents thereof.

The present invention relates to (i) a process for producing a superabsorbent monomer mixture comprising a water-soluble ethylenically unsaturated compound containing acrylic acid, a polymerization initiator, an ionic crosslinking agent and an aqueous solvent; (Ii) a step of impregnating the mixture of the superabsorbent monomer mixture with the yarn to apply the superabsorbent monomer mixture to the yarn; And (iii) heat-treating the yarn coated with the superabsorbent monomer mixture to polymerize and crosslink the superabsorbent monomer mixture applied to the yarn.

Specifically, in the present invention, a monomer mixture containing a water-soluble ethylenically unsaturated compound containing acrylic acid, a polymerization initiator, a crosslinking agent and an aqueous solvent is prepared.

The present invention is characterized in that an ionic crosslinking agent is contained in the mixture of superabsorbent monomers.

The ionic cross-linking agent is a metal-based cross-linking agent, for example, ammonia dicrononium carbonate or zinc oxide. The ionic crosslinking agent improves the adhesion between the coating layer and the yarn of the mixed solution of the water-absorbing monomer mixture applied to the yarn, thereby effectively preventing the separation between the yarn and the coating layer when the superabsorbent yarn passes through the guide during the production process, do.

The monomer superabsorbent mixture may further contain other additive components such as a water-soluble ethylenically unsaturated compound, a polymerization initiator, a crosslinking agent, and an aqueous solvent as well as a surfactant.

As an example of the preparation, the monomer mixture is prepared by mixing the water-soluble ethylenically unsaturated compound, the polymerization initiator, the ionic crosslinking agent and the aqueous solvent.

The water-soluble ethylenically unsaturated compound containing acrylic acid is acrylic acid, a salt of acrylic acid, methacrylic acid, a salt of methacrylic acid, acrylamide, or a mixture thereof.

As an example of the polymerization initiator, persulfate compounds such as ammonium persulfate and the like are used.

Next, the monomer mixture solution is impregnated with a yarn to apply a mixture of a superabsorbent monomer to the yarn.

The thread is an aramid multifilament or glass fiber.

Next, the yarn to which the mixture of the superabsorbent monomer mixture is applied is heat-treated to polymerize and cross-link a mixture of the superabsorbent monomers coated on the yarn to produce a superabsorbent yarn.

Preferably, the heat treatment is performed for 10 to 80 seconds while passing the yarn having the superabsorbent monomer mixture liquid through the heat treatment unit at a temperature of 260 to 350 ° C.

Meanwhile, in the present invention, a process may be further performed in which a portion of the mixture of superabsorbent monomers mixed with the superabsorbent monomer mixture is passed through the micropores before heat treatment, and a portion of the excess superabsorbent monomer mixture is removed.

In the present invention, since the ionic crosslinking agent is contained in the superabsorbent monomer mixture, the adhesion between the yarn and the superabsorbent monomer mixture is greatly improved, and the coating layer of the superabsorbent monomer mixture liquid applied (coated) The absorbency of the high-absorptive yarn can be further improved.

The present invention uses a highly water-absorbing monomer mixture instead of the polymeric polymer dispersion or aqueous solution in the prior art, thereby simplifying the manufacturing process and reducing the manufacturing cost.

In addition, the present invention improves the productivity by increasing the drying speed due to the heat of reaction occurring when the monomers in the superabsorbent monomer mixture are polymerized and crosslinked in the heat treatment step.

Hereinafter, the effects of the present invention will be described in more detail through examples and comparative examples. The embodiments illustrated below are for illustrative purposes only and do not limit the scope of the present invention.

Example  One

A mixture of 247 g of acrylic acid, 23 g of acrylamide, 0.8 g of ammonium zirconium carbonate (ionic crosslinking agent), 0.8 g of ammonium persulfate (initiator), 120 g of sodium hydroxide and 500 g of water was mixed to prepare a superabsorbent monomer mixture having a monomer concentration of 10% Respectively.

Next, an aramid filament having a fineness of 2,840 deniers was impregnated into the prepared superabsorbent monomer mixture, and the excess impregnation solution (monomer mixture) was removed while passing through fine holes, so that the impregnation amount of the superabsorbent monomer mixture was 10% by weight Respectively.

Next, the aramid filaments impregnated with the superabsorbent monomer mixture were heat-treated for 20 seconds while passing through the heat treatment unit at 300 캜 to prepare a superabsorbent yarn.

The results of evaluating various physical properties of the prepared superabsorbent yarn were as shown in Table 1.

Example  2

A superabsorbent yarn was prepared in the same manner as in Example 1, except that 0.8 g of zinc oxide was used instead of ammonium zirconium carbonate as an ionic crosslinking agent in the preparation of the superabsorbent monomer mixture in Example 1.

The results of evaluating various physical properties of the prepared superabsorbent yarn were as shown in Table 1.

Comparative Example  One

The procedure of Example 1 was repeated except that 0.8 g of ethylene glycol diglycidyl ether was replaced with 0.8 g of ammonium zirconium carbonate (ion-crosslinking agent) in the preparation of the superabsorbent monomer mixture in Example 1, Absorbent yarn was produced. The results of evaluating various physical properties of the prepared superabsorbent yarn were as shown in Table 1.

Comparative Example  2

In the same manner as in Example 2 except that 0.8 g of ethylene glycol di-methacrylate was replaced with 0.8 g of zinc oxide (ion-crosslinking agent) in the preparation of the superabsorbent monomer mixture in Example 2, a superabsorbent yarn . The results of evaluating various physical properties of the prepared superabsorbent yarn were as shown in Table 1.

division Absorbency (%) Strong (kgf) Example 1 595 64.39 Example 2 530 64.15 Comparative Example 1 580 63.05 Comparative Example 2 590 64.05

Various physical properties of the superabsorbent yarn shown in Table 1 were measured by the following methods.

Absorbency measurement of yarn

2 g of the sample was taken and cut to a uniform length of about 2 cm, and then immersed in 500 ml of distilled water at 20 캜 for 2 minutes each. Excess water was removed from fully wetted samples by centrifugation (2000 rpm, 1 min). After measuring the weight of the samples with excess water removed, the samples were hot air dried in an oven at 110 DEG C for 24 hours. After the weights of the dried samples were measured, the absorbency of the yarn was calculated using Equation 1 below.

Equation 1: Absorbency (%) of yarn = [(A-B) / B] x 100

Where A is the weight of the sample measured in the state of excess water removed after being immersed in distilled water and B is the weight of the sample measured after hot air drying.

Strength measurement of yarn

The specimen was stretched until a specimen of 25 cm length was broken in an Instron Engineering Corp. (Canton, Mass.) According to ASTM D885, and the strength at the breaking point was determined. At this time, the tensile speed was 300 mm / min and the super load was the fineness x 1/30 g. This process was repeated 5 times and the average value was obtained.

The superabsorbent yarn produced in Examples 1 and 2 did not peel off the coating layer of the superabsorbent material coated on the yarn even though it was passed through the guide during the production process. However, in Comparative Example 1 and Comparative Example When the superabsorbent yarn made in Example 2 was passed through the guide during the production process, the coating layer of the superabsorbent material applied to the yarn was peeled off from the yarn.

Claims (8)

(I) a step of producing a mixture of a water-soluble ethylenically unsaturated compound containing acrylic acid, a polymerization initiator, an ionic crosslinking agent and an aqueous solvent;
(Ii) a step of impregnating the mixture of the superabsorbent monomer mixture with the yarn to apply the superabsorbent monomer mixture to the yarn; And
(Iii) heat-treating the yarn coated with the superabsorbent monomer mixture to polymerize and crosslink the superabsorbent monomer mixture liquid applied to the yarn. The method according to claim 1, wherein the ionic crosslinking agent is a metal-based crosslinking agent. The method according to claim 1, wherein the ionic crosslinking agent is one selected from the group consisting of ammonium zirconium carbonate and zinc oxide. The process according to any one of claims 1 to 3, further comprising the step of passing a high-absorptive monomer mixture liquid through the fine holes before heat treatment and removing a portion of the superabsorbent monomer mixture, Gt; The process according to claim 1, wherein the water-soluble ethylenically unsaturated compound containing acrylic acid is at least one selected from the group consisting of acrylic acid, acrylic acid salt, methacrylic acid, methacrylic acid salt and acrylamide. The method according to claim 1, wherein the polymerization initiator is a persulfate compound. The method according to claim 1, wherein the yarn is one selected from the group consisting of aramid multifilament and glass fiber. 2. The method of claim 1, wherein heat treatment is performed for 10 to 80 seconds while passing the yarn having the superabsorbent monomer mixed solution passed through the heat treatment unit at a temperature of 260 to 350 占 폚.