KR101180508B1 - Polyurethane composition for high tenacity spandex fiber, and spandex fiber prepared using the polyurethane composition - Google Patents

Abstract

The present invention is to provide a spandex fiber excellent in strength, to provide a polyurethane resin composition for the spandex fiber and a fiber prepared therefrom. The polyurethane resin composition is characterized in that it comprises a polymer additive prepared by reacting an organic diisocyanate with a low molecular diol or a low molecular diamine.

Description

Polyurethane composition for spandex fiber with excellent strength and spandex prepared from the same {Polyurethane composition for high tenacity spandex fiber, and spandex fiber prepared using the polyurethane composition}

The present invention relates to a polyurethane resin composition for spandex fibers having excellent strength and to spandex fibers comprising the same.

Spandex fibers are widely known as highly stretchable polyurethane based fibers having a urethane bond of at least 85% by weight. Generally, spandex fibers extrude a spinning solution, which is a polyurethane resin composition, through a nozzle, and the solvent is dry spinning that introduces a heating gas for evaporation and drying; Wet spinning, which solidifies the polymer while eluting the solvent by passing the spinning water bath, chemical spinning, in which the prepolymer solution with isocyanate in the reaction solution containing an amine chain extender is extruded through a nozzle and subjected to chain extension reaction, or poly The urethane resin composition is prepared through melt spinning which is extruded through a nozzle in a molten state of heat and cooled.

The technology of having high strength in spandex fibers is of great importance. In order to improve the strength of spandex fibers, conventionally, diphenylmethane-4,4'-diisocyanate is used as the diisocyanate, but the diphenylmethane-2,4'-diisocyanate included therein is generally used. A method was used to contain higher than levels.

For example, Japanese Patent Application No. 1993-226050 discloses spandex fibers by including diphenylmethane-2,4'-diisocyanate in the diisocyanate used in the synthesis of polyurethaneurea polymer to produce spandex fiber. It provides a method for preparing.

However, when the spandex fiber is manufactured by such a conventional method, there is a problem that the strength of the spandex fiber is not high enough to be suitable for use in applications requiring high strength.

Accordingly, the present invention is to provide a polyurethane resin composition for forming a spandex fiber excellent in strength and a high strength spandex fiber prepared from the polyurethane resin composition.

The polyurethane resin composition for spandex fiber according to the present invention is prepared by reacting an organic diisocyanate with a polymer diol to prepare a polyurethane precursor, dissolving it in an organic solvent, and then reacting with a chain extender diamine and a chain terminator monoamine. A polyurethane resin composition prepared by mixing a polymer resin, wherein the terminal of the polymer additive is a methyl group or an amine group, and as a raw material of the polymer additive, the middle of the molecular chain is composed of carbon and hydrogen or carbon and oxygen and hydrogen, and both ends are primary At least one diamine, which is an amine, is used, and the number average molecular weight of the polymer additive is 2,000 to 50,000.

According to another preferred feature of the invention, the number average molecular weight of the polymer additive is 5,000 to 50,000.

According to another preferred feature of the present invention, the polymer additive is added so that the solid content of the polymer additive is 1 to 25% of the total solid content.

According to another preferred feature of the present invention, diamine having a molecular weight of 200 or more is used as one of the raw materials of the polymer additive.

In the present invention, the spandex fiber prepared from the polyurethane resin composition is enhanced in strength without deteriorating heat resistance, thereby improving post-processing processability such as knitting and covering using a spandex yarn.

Therefore, the reliability of the spandex fiber according to the present invention is improved, it can be usefully used in the fabric of the application that requires a function such as heat resistance, high strength.

The present invention is characterized in that it comprises a polymer additive prepared by reacting an organic diisocyanate with a diol and / or a diamine or a monoamine.

The polymer additive has at least one or more diamines whose terminal is a methyl group or an amine group and the raw material of the polymer additive is composed of carbon and hydrogen in the middle of the molecular chain or carbon and oxygen and hydrogen and both ends are primary amines. The number average molecular weight of the polymer additive is characterized in that 2,000 to 50,000.

The method for synthesizing the polymer additive includes reacting an organic diisocyanate with a diamine and / or a monoamine in an appropriate equivalent ratio such that the terminal group is an amine group or a methyl group, and reacting the organic diisocyanate and a low molecular diol in an equivalent equivalent ratio such that the terminal is an isocyanate group. Thereafter, there is a method of reacting it with diamines and / or monoamines so that the terminal group is finally an amine group or a methyl group. The reaction can be carried out in a solvent for uniform reaction.

In the polymer additive, organic diisocyanates include diphenylmethane-4,4'-diisocyanate, hexamethylene diisocyanate, toluene diisocyanate, butylene diisocyanate, isophorone diisocyanate and hydrogenated P, P-methylene diisocyanate And the like can be used.

Examples of the low molecular diols include ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, N-methyldiethanolamine, N-butyldiethanolamine, t-butyl diethanolamine, and the like.

Examples of the diamines include ethylenediamine, 1,2-diaminopropane, 1,3-diaminopropane, hexamethylenediamine, hydrazine, bis- (3-aminopropyl) -methylamine, and diamines having a molecular weight of 200 or more. May also be used. When using diamine whose molecular weight is 200 or less, there exists a problem in solubility and superposition | polymerization control.

In addition, the monoamine is used as a chain terminator, and examples thereof include diethylamine, monoethanolamine, dimethylamine, N-butylamine, dibutylamine, and the like.

The final number average molecular weight prepared in this way is 2000 to 50000. If it is lower than this, the desired effect may not be obtained by spilling in a post-processing process such as dyeing of a fabric including spandex fibers, and if it is higher than this, additives may be uneven and processability may be reduced in storage and spinning processes.

The segmented polyurethane resin composition used in the spandex fiber of the present invention is prepared by reacting an organic diisocyanate and a polymer diol to prepare a polyurethane precursor, as it is known in the art, and then dissolving it in an organic solvent, followed by low molecular diamine and low molecular mono. After reacting with an amine, it is prepared by mixing the polymer additives described above.

Here, the polymer additive is included so that the solid content of the polymer additive is 1 to 25% by weight of the total solid content. If the solid content is less than 1% by weight, there is a problem that the physical properties are not improved, and if the solid content is more than 25% by weight, there is a problem of migrating process.

In the polyurethane resin composition, as the organic diisocyanate, diphenylmethane-4,4'-diisocyanate, hexamethylene diisocyanate, toluene diisocyanate, butylene diisocyanate, isophorone diisocyanate and hydrogenated diphenylmethane-4 , 4'-diisocyanate and the like can be used.

As the polymer diol, polytetramethylene ether glycol having a molecular weight of 1500 to 3100 is preferable. If the molecular weight is less than 1500, there is a problem that the elongation of the yarn is low and the function as the spandex yarn is lowered. If the molecular weight is more than 3100, the crystallinity is too high and elasticity is not normally expressed.

The diamines are used as chain extenders, and examples thereof include ethylenediamine, 1,2-diaminopropane, 1,3-diaminopropane, hexamethylenediamine, hydrazine, bis- (3-aminopropyl) -methylamine Etc.

In addition, the monoamine is used as a chain terminator, and examples thereof include diethylamine, monoethanolamine, dimethylamine, N-butylamine, dibutylamine, and the like.

In addition, the present invention provides a spandex fiber prepared from the polyurethane resin composition.

The present invention can be well understood by the following examples, the following examples are for illustrative purposes of the present invention and are not intended to limit the protection scope of the present invention.

Preparation of Polymer Additives Solution

90 g of 1,4-butanediol and 340 g of hydrogenated diphenylmethane-4,4'-diisocyanate were charged to the reactor. The reaction was stirred at 90 ° C. for 90 minutes in a nitrogen gas stream to prepare a polyurethane precursor having an isocyanate at the sock end. 700 g of dimethylacetamide was added to the polyurethane precursor and dissolved to obtain a polyurethane precursor solution. Then, 17 g of ethylenediamine and 4 g of N-butylamine were dissolved in 100 g of dimethylacetamide, and reacted while gradually adding the precursor solution at 10 ° C. to prepare a polymer additive solution.

Preparation of Polyurethane Resin Composition

190 g of diphenylmethane-4,4 'diisocyanate and 790 g of polytetramethylene ether glycol (molecular weight 1800) were charged to a reactor. The reaction was stirred at 90 ° C. for 90 minutes in a nitrogen gas stream to prepare a polyurethane precursor having an isocyanate at the sock end. 1460 g of dimethylacetamide was added to the polyurethane precursor and dissolved to obtain a polyurethane precursor solution. 20 g of ethylenediamine and 3 g of diethylamine were dissolved in 400 g of dimethylacetamide and added to the precursor solution at 10 ° C. to obtain a polymer solution having a methyl group or an amine terminal, and the polymer additive solution was added to the solid content of the polymer additive. The polyurethane resin composition to be used in the preparation of the spandex fiber was prepared by uniformly mixing the ratio to 5%.

Preparation of Spandex Fiber

After defoaming the polyurethane resin composition, an elastic yarn of 4 filaments 40 denier, that is, spandex fibers was prepared by a dry spinning process using a spinning stock solution. Spinning temperature was adjusted to 250 ° C.

In preparing the polyurethane precursor of the polymer additive in Example 1, the molar ratio of 1,4-butanediol and hydrogenated diphenylmethane-4,4'-diisocyanate is 1: 1.5, and the rest is An elastic yarn was produced in the same manner.

First, solvent dimethylacetamide and a polyoxy-1,2-propylenediamine having a molecular weight of 2000 were added to the reactor so that the solid content concentration of the prepared polymer additive was 35%, uniformly mixed, and cooled to 10 ° C. While stirring, diphenylmethane-4,4'-diisocyanate is gradually added to react so that the molar ratio of polyoxy-1,2-propylenediamine and hydrogenated diphenylmethane-4,4'-diisocyanate is 1.3: 1. , A polymer additive solution having an amine group in the sock end was prepared, and the rest of the elastic yarn was prepared in the same manner as in Example 1.

 Comparative Example 1

Spandex fibers were prepared in the same manner as in Example 1, but the spandex fibers were prepared using only a polyurethane resin composition without including a polymer additive.

Comparative Example 2

Spandex fibers were prepared in the same manner as in Example 1, but the spandex fibers were prepared such that the solid content ratio of the polymer additive was 0.5%.

[Comparative Example 3]

Spandex fibers were prepared in the same manner as in Example 1, but the spandex fibers were prepared such that the solid content ratio of the polymer additive was 30%.

 [Evaluation example]

The strength and elongation of the elastic yarns of Examples 1 to 3 and Comparative Examples 1 to 3 were measured.

More specifically, using Instron's INSTRON 5565, the gauge length was set to 2 inches and the elastic filament long fiber sample was stretched at a constant drawing speed of 500 mm / min to break the breaking strength and elongation at break. Measured.

In the case of heat resistance, after heat treatment in an oven at 190 ° C. for 1 minute while the yarn is stretched to 300%, the breaking strength is measured by the above method, and the yarn heat resistance is measured by calculating the strength ratio before and after the heat treatment. It was.

The strength, elongation, and heat resistance measured as described above are shown in Table 1. As a result, it can be seen that the elastic yarns of Examples 1 to 3 according to the present invention had about 20% more strength than Comparative Examples 1 to 2. In Comparative Example 3, the elongation was too low to be used as a general purpose spandex.

Although the present invention has been described in connection with the above-mentioned preferred embodiments, it is possible to make various modifications or variations without departing from the spirit and scope of the invention. Accordingly, the appended claims include such modifications and variations as fall within the spirit of the invention.

Claims (6)

In a polyurethane resin composition prepared by reacting an organic diisocyanate with a polymer diol to prepare a polyurethane precursor, dissolving it in an organic solvent, reacting with a chain extender diamine and a chain terminator monoamine, and then mixing a polymer additive. At least one or more diamines of which the terminal of the polymer additive is a methyl group or an amine group, and the raw material of the polymer additive are composed of carbon and hydrogen or carbon and oxygen and hydrogen in the middle of the molecular chain and both terminals are primary amines, Polyurethane resin composition for spandex fibers, characterized in that the number average molecular weight of the polymer additive is 2,000 to 50,000. The method of claim 1,
Polyurethane resin composition for spandex fibers characterized in that the number average molecular weight of the polymer additive is 5,000 to 50,000. The method of claim 1,
Polyurethane resin composition for spandex fibers characterized in that the number average molecular weight of the polymer additive is 10,000 to 50,000. The method of claim 1,
Polyurethane resin composition for spandex fibers, characterized in that it comprises a polymer additive so that the solid content of the polymer additive is 1 to 25% of the total solid content. The method of claim 1,
Polyurethane resin composition for spandex fibers characterized in that a diamine having a molecular weight of 200 or more as one of the raw materials of the polymer additive. Spandex fiber manufactured using the polyurethane resin composition for spandex fibers of any one of Claims 1-5.