KR20060077892A - Elastic fiber with easy setting property - Google Patents

Abstract

The present invention relates to a polyurethane elastic yarn having excellent settability and a method for manufacturing the same, wherein a mixture of polystyrene (PS) and polystyrene-acrylonitrile copolymer (SAN) is about 1 to 30 based on the weight of a conventional polyurethane polymer. The method for producing a polyurethane elastic yarn mixed and spun in a weight% ratio and the heat-resistant polyurethane elastic yarn prepared by the above method is 75% or more.

Polyurethane Elastic Yarn, Polystyrene (PS), Polystyrene-Acrylonitrile Copolymer (SAN), Thermoset, Light Resistance

Description

Elastic yarn with excellent setability and manufacturing method thereof {Elastic Fiber with Easy Setting Property}

The present invention relates to a polyurethane elastic yarn having excellent setability and a method for manufacturing the same. More specifically, the thermosetability produced by mixing a polystyrene and a polystyrene-acrylonitrile copolymer in an appropriate ratio to a conventional polyurethane polymer is high. The present invention relates to a polyurethane elastic yarn having excellent light resistance and a manufacturing method thereof.

Polyurethane generally reacts with a polyol, a high molecular weight diol compound, and an excess of diisocyanate compound to obtain a prepolymer having an isocyanate group at the end of the polyol, and dissolving the prepolymer in a suitable solvent. Thereafter, the solution is prepared by a secondary polymerization reaction in which a diamine-based or diol-based chain extender is added and reacted.

In general, polyurethane fibers may be used in combination with various other fibers such as acrylic, wool, cotton, silk, etc., depending on the application, and particularly, elastic fibers having a long chain segment content of 85 wt% or more are called spandex.

Polyurethane fibers are being actively used for various purposes because of their inherent properties with high elasticity, and as the range of their use expands, new additional characteristics of existing polyurethane fibers continue to be demanded. Until now, a number of polyurethane fibers, which have been further strengthened in heat resistance and elastic recovery, have been developed, and in recent years, the demand for polyurethane fibers having high heat setability has gradually increased.

In response, efforts have been made to improve the thermosetability of polyurethane fibers. For example, Japanese Patent Laid-Open Nos. 63-53287 and 63-53288 disclose thermoset properties of polyurethane elastic yarns using polyurethanes prepared by adding specific additives such as diisocyanate dimers or fine powder silica, respectively. A method of improving is disclosed. However, these methods have problems such as difficulty in uniformly dispersing the additives in the polyurethane polymerization product, difficulty in selecting appropriate mixing conditions, and complicated polymerization reaction itself.

Alternatively, Japanese Patent Publication No. 43-639 discloses a prepolymer having an hydroxyl group end and an isocyanate end by reacting a compound containing a diisocyanate group with a mixture of polymer diol and a low molecular weight diol of 1 to 3 moles of the polymer diol. After preparing a prepolymer having the polymer, a method of reacting both to obtain a polyurethane polymer is described. However, the polyurethane obtained by this method has a limitation that it can be applied only to melt spinning.

In addition, Korean Patent Laid-Open Publication No. 2001-5854 is characterized in that the polyurethane polymer in the fluid state obtained by reacting both isocyanate terminal prepolymer and hydroxyl terminal prepolymer having relatively close viscosity to each other and then reacted with each other is continuously extruded through a nozzle. It describes a method for producing a polyurethane elastic yarn. According to this method, since the two prepolymers have similar viscosities, it is possible to uniformly mix each component in the secondary polymerization reaction, and to improve the stirring effect and the improvement of the radiation stability. Compared to the elastic yarn manufacturing method, not only the process is very complicated, but also the improvement of the stirring effect and the spinning stability can be made relatively easily through the manipulation of the process conditions, and has a disadvantage in that the practicality is not so large.

On the other hand, Japanese Patent Laid-Open No. 7-316922 proposes a relatively simple method to improve the heat setability of polyurethane elastic yarn, which is basically a polyurethane elastic yarn produced by a conventional method, The alternative is to replace some of the urethane components with thermoplastic polyurethane. The thermoplastic polyurethane is prepared by using diol instead of diamine as a chain extender in a secondary polymerization reaction in the process of preparing a conventional polyurethane polymer. However, this method improves the heat setability of the polyurethane elastic yarn, but has a disadvantage in that elongation, which is a main feature of the polyurethane elastic yarn, is lowered and an unnecessary increase in modulus is caused. In addition, a method of using a low molecular weight styrene maleic anhydride-based copolymer having a number average molecular weight of less than 5,000 to replace a part of a polyurethane polymer prepared by a conventional method is described, but it is also possible to improve heat setability and basic properties of yarn. It is not preferable when considering the maintenance aspect.

On the contrary, Korean Patent Publication No. 2001-16788 discloses a method of improving heat setability of yarns by performing a separate heat treatment step after spinning during the process of producing polyurethane fibers by a general dry spinning method. However, this method also requires additional equipment in addition to the existing spinning equipment, and further improves the heat setability of the yarn because it causes unnecessary deterioration of the yarn, but has the disadvantage of deteriorating the basic properties such as elongation and strength.

The present invention is to solve the problems of the prior art as described above, in the production of polyurethane elastic yarn having excellent heat setability, polystyrene (PS) and polystyrene-acrylonitrile in the polymer solution required for the production of conventional polyurethane elastic yarn By dissolving and mixing the reel copolymer (SAN) in an appropriate ratio, it does not reduce the strength compared to the polyurethane elastic yarn produced in the conventional manner without changing the conventional production process conditions and equipment, and greatly increases heat setability and light resistance. An object of the present invention is to provide an improved polyurethane elastic yarn and its manufacturing method.

Hereinafter, the method of manufacturing the polyurethane elastic yarn of this invention is demonstrated in detail. The segment polyurethane used in the polyurethane production of 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 diamine and a monoamine.

Specific examples of the organic diisocyanate used in the preparation of the polyurethane elastic yarn used in the present invention include 4.4'-diphenylmethane diisocyanate, 1,5'-naphthalenediisocyanate, 1,4'-phenylenediisocyanate, hexa Methylene diisocyanate, 1,4'-cyclohexanediisocyanate, 4,4'-dicyclohexyl methane diisocyanate, isophorone diisocyanate and the like and can be exemplified by one or a mixture of two or more of these organic diisocyanates. Can be.

Polymeric diols include polytetramethylene ether glycol, polypropylene glycol, polycarbonate diol and the like. Diamines are used as the chain extender, and examples thereof include ethylenediamine, 1,2'-propylenediamine, hexamethylenediamine, xylenediamine, 4,4'-diphenylmethanediamine, hydrazine, and the like. The above mixture can be illustrated.

In order to obtain the polyurethane elastic yarn of the present invention, a polystyrene and a polystyrene-acrylonitrile copolymer having a number average molecular weight of 10,000 to 500,000 are mixed at an appropriate ratio, and then mixed into a polyurethane polymer having a number average molecular weight of 10,000 to 500,000. Radiate by If the number-average molecular weight of PS and SAN is less than 10,000, there is a problem that it may come out of the yarn during dyeing or post-processing and become a pollutant.If the number-average molecular weight exceeds 500,000, phase separation occurs when mixing with the polyurethane polymer to produce spinning and productivity. Can affect.

The mixing ratio of the mixture of the polystyrene (PS) and the polystyrene-acrylonitrile (SAN) copolymer of the present invention is preferably 1 to 30% by weight based on the weight of the polyurethane. If less than 1% by weight, the set properties of the final polyurethane elastic yarn is lowered, and if it exceeds 30% by weight, the basic physical properties of the polyurethane such as elastic modulus, strength, elongation, etc. are greatly reduced. In the present invention, the spinning method is not particularly limited, and the conventional dry spinning, wet spinning and melt spinning methods can be followed as they are except for chemical spinning.

The physical properties of the polyurethane elastic yarn of the present invention are influenced by the mixing ratio of the polystyrene and the polystyrene-acrylonitrile copolymer to be mixed, and also by the mixing ratio of the polystyrene and polystyrene-acrylonitrile copolymer and the existing polyurethane to be mixed. get affected. Therefore, by properly adjusting the mixing ratio of the appropriate polystyrene and polystyrene-acrylonitrile polymer and the existing polyurethane, it is possible to obtain a polyurethane elastic yarn having excellent heat setability and light resistance, while maintaining the basic physical properties equivalent to the existing polyurethane elastic yarn have.

Hereinafter, the present invention will be described in more detail with reference to examples, but these examples are for illustrative purposes only and should not be construed as limiting the present invention.

In Examples and Comparative Examples to be described later, the heat setability and strength of the polyurethane elastic yarn were measured as follows.

* Heat Settable

The stretched yarn was stretched 100%, and then heat-treated at 170 ° C. for 1 minute while exposed to the atmosphere. Thereafter, after cooling to room temperature, the length of the yarn was measured, and heat setability of the yarn was calculated according to the following equation.

Heat Setability (%) = {(length after heat treatment-initial length) / (height length-initial length)} x 100

* burglar

The Instron 5565 of INSTRON Corporation was used to measure the load value when the sample was cut by stretching the sample cut into 5 cm lengths of yarn at a constant speed of 500 mm / min under 20 ° and 65% humidity conditions. .

* Light resistance measurement

Ultraviolet light (UV test) stretches the yarn 100% and measures the rate of change of strength after 24 hours of sunlight treatment

Example 1

518 g of diphenylmethane-4,4'-diisocyanate and 2328 g of polytetramethylene ether glycol (molecular weight 1800) were reacted in a nitrogen gas stream with stirring for 80 to 90 minutes to prepare a polyurethane prepolymer having an isocyanate at the sock end. . After cooling the prepolymer to room temperature, 4269 g of dimethylacetamide was added to obtain a polyurethane prepolymer solution. Subsequently, 34.4 g of ethylenediamine, 10.6 g of propylenediamine, and 9.1 g of diethylamine were dissolved in 1117 g of dimethylacetamide and added to the prepolymer solution at 10 ° C. or lower to obtain a polyurethane solution.

As an additive with respect to solid content of this polymer, 1.5 weight% of ethylene bis (oxyethylene) bis- (3- (5- t -butyl-4-hydroxy m -toyl) propionate), 5,7-di- t -Butyl-3- (3,4-dimethylphenyl) -3H-benzofuran-2-one 0.5% by weight, 1,1,1 ', 1'-tetramethyl-4,4'-(methylene-di- p 1 weight% of -phenylene) dicicacarbide, 1 weight% of poly (N, N-diethyl-2-aminoethyl methacrylate), and 0.1 weight% of titanium dioxide were added and mixed to obtain a polyurethane spinning stock solution.

A polystyrene-acrylonitrile polymer having a number average molecular weight of 100,000 and a polystyrene-acrylonitrile polymer having a number average molecular weight of 50,000 were used at 50:50 wt%. After the polystyrene was completely dissolved in a dimethylacetamide (DMAC) solvent, a mixed solution was prepared by adding 50% by weight of the polystyrene-acrylonitrile.

The polystyrene and polystyrene-acrylonitrile mixture thus prepared were mixed with a polyurethane polymer prepared in a conventional manner at a ratio of 10% by weight to prepare a spinning solution, and then spinning was carried out using the spinning solution. Spinning used the conventional dry spinning method used for the manufacturing method of a polyurethane elastic yarn.

The thermal setability and basic physical properties and light resistance of the polyurethane elastic yarn thus prepared are shown in Table 2 below in comparison with the conventional polyurethane elastic yarn.

Examples 2-5 'and Comparative Examples 1-3

 Except for changing the mixing ratio (% by weight) of the mixture of the polystyrene and polystyrene-acrylonitrile polymer to be added with the polyurethane polymer prepared in a conventional manner as shown in Table 1 Urethane elastic yarn was manufactured.

The thermal setability and basic physical properties of the polyurethane elastic yarn according to each example and comparative example are shown in Table 2 below.

TABLE 1

TABLE 2

* Conventionally, Comparative Example 3, which is a conventional technology, does not add a PS + SAN mixture.

As can be seen in Table 2, the polyurethane elastic yarn produced by the method of the present invention has a high heat setability of 75% or more and also increase the light resistance by 14% or more compared with the conventional, the strength change rate compared to the conventional polyurethane elastic yarn Is very low, within 6.7%.

Polyurethane elastic yarn prepared by the manufacturing method of the present invention not only has excellent heat setability, but also has a very low rate of change in basic physical properties compared to conventional polyurethane elastic yarns, and thus, existing processes for producing products requiring excellent heat setability and light resistance. It can be applied directly and used without any change of condition.

Claims (2)

In the polyurethane elastic yarn production method, a mixture of polystyrene having a number average molecular weight of 10,000 to 500,000 and a polystyrene-acrylonitrile copolymer having a number average molecular weight of 10,000 to 500,000 is 1:99 to 30:70 weight based on the polyurethane polymer. Method for producing a polyurethane elastic yarn characterized in that the spinning by mixing in a percentage ratio. A mixture of polystyrene having a number average molecular weight of 10,000 to 500,000 and a polystyrene-acrylonitrile copolymer having a number average molecular weight of 10,000 to 500,000 is contained in an amount of 1 to 30% by weight based on the weight of the polyurethane polymer, and the heat setability is 75%. The polyurethane elastic yarn characterized by the above.