KR100996357B1 - Composition for Spandex Fibers with Excellent Stress Retention Rate - Google Patents

Abstract

The present invention provides a composition for spandex fibers comprising a polyurethane polymer, a polymer additive, and a solvent, wherein the polymer additive is prepared by reacting a polymer polyhydric alcohol with an organic isocyanate to prepare a polyurethane precursor and reacting it with a secondary amine. It relates to a composition for spandex fibers having a high stress retention.

According to the present invention, it is possible to provide an excellent spandex fiber composition having a high level of stress and high stress retention while not having high adhesiveness and high uniformity of solution, which is required for products requiring excellent resilience against repeated elongation. Can be applied.

Polyurethane Elastic Yarn, Stress, Additives

Description

Composition for spandex fiber with excellent stress retention rate {COMPOSITION FOR SPANDEX FIBER HAVING A HIGH TENSION MAINTENANCE}

The present invention relates to a composition for spandex fibers having an excellent stress retention rate, and more particularly, a composition comprising a polyurethane polymer, a polymer additive, and a solvent, wherein the polymer additive reacts a polyhydric alcohol with an organic isocyanate to make a polyurethane. The present invention relates to a composition for spandex fibers having high stress retention, which is prepared by preparing a precursor and reacting it with a secondary amine.

In general, spandex fibers are widely known as highly stretchable polyurethane fibers having a urethane bond of 85% by weight or more. Spandex fibers generally include a spinning yarn which extrudes a spinning solution containing polyurethane through a nozzle and introduces a heating gas for evaporating and drying the solvent; Wet spinning to solidify the polymer while eluting the solvent through a spinning bath; Chemical spinning for extending the chain reaction by extruding a prepolymer solution having an isocyanate through a nozzle in a reaction solution containing an amine chain extender; Or melt spinning for extruding and cooling the polyurethane through a nozzle in a molten state of heating;

It is very important that the spandex fiber has a high level of stress retention when it is repeatedly stretched and shrunk, and conventional techniques in this field use 100% polytetramethylene glycol as a polymer diol. The technique which raises a stress retention rate by using the polytetramethylene glycol of the copolymer form containing a methyl methyl tetrahydrofuran and a neopentyl group at a part is mentioned.

For example, US Pat. No. 5,000,899 describes the preparation of soft segments using copolymers of 3-methyltetrahydrofuran and tetrahydrofuran, followed by the preparation of spandex using ethylenediamine and 2-methylpentamethylenediamine as chain extenders. How to do it.

However, when the spandex is manufactured by such a conventional method, the prepared spandex has high adhesiveness and uneven solution, which causes many problems in process and products. For example, workability during dry spinning is poor, nozzles are frequently clogged, and adhesion between storage occurs due to high interadhesion, causing problems in the maritime process.

The present invention has been made to solve the above problems,

An object of the present invention is to provide a composition for spandex fibers that is not high in tackiness, has high uniformity of solution, and has good spinning workability and high stress retention.

Aspects of the present invention for solving the above technical problem is

70 to 97 parts by weight of a polyurethane polymer;

3 to 30 parts by weight of a polymer additive based on solids in the polyurethane polymer; and

A composition for spandex fibers containing 60 to 75 parts by weight of an organic solvent,

The polymer additive has three or more hydroxyl groups and has a high stress retention, characterized in that the polymer polyhydric alcohol having a molecular weight in the range of 500 to 7000 and an organic diisocyanate to make the terminal isocyanate group, and then reacted with a secondary amine It relates to a composition for spandex fibers having a.

Hereinafter, the present invention will be described in more detail.

The composition for spandex fibers of the present invention is a polymer additive prepared by reacting a polymer polyhydric alcohol having a molecular weight range of 500 to 7000 with an organic diisocyanate having three or more hydroxyl groups to make an end with an isocyanate group, and then reacting it with a secondary amine. The polyurethane polymer is included in a weight ratio of polyurethane polymer: polymer additive = 97: 3 to 70:30 based on solids content in polyurethane.

The polymer additive used in the present invention is an organic diisocyanate and a hydroxyl group: isocyanate group = 1: 1.5 to 1: 7 (equivalent ratio basis) of a polymer polyhydric alcohol having a molecular weight of 500 to 7000 having three or more hydroxyl groups It dissolves in a solvent and makes it react, and a secondary amine is added to this solution, and it reacts with an isocyanate group, and it makes it so that all the terminal may become secondary amine.

 Polyethylenetriol, polypropylenetriol, polytetramethylenetriol, and the like may be used as the polymer polyhydric alcohol, but are not limited thereto. The polymer polyhydric alcohol reacts with the organic diisocyanate to form an additive, and mixes with the polyurethane polymer to cause crosslinking. When a low molecular weight polyhydric alcohol such as glycerol is used instead of the high molecular weight polyhydric alcohol, there is no effect of increasing the stress retention.

The organic diisocyanate is also not particularly limited, but diphenylmethane-4,4'-diisocyanate, hexamethylene diisocyanate, toluene diisocyanate, butylene diisocyanate, hydrogenated P, P-methylene diisocyanate, etc. may be used. have.

In the present invention, the reaction ratio of the polymer polyhydric alcohol and organic diisocyanate for the preparation of the polymer additive is reacted by mixing a hydroxyl group: isocyanate group = 1: 1.5 to 1: 7 (equivalent ratio basis), the ratio of isocyanate groups is If it is less than this range, it is difficult to control the viscosity due to excessive crosslinking reaction, and if it exceeds this range, the effect of improving the stress retention rate of the additive is inferior.

The secondary amine used in the present invention is not particularly limited, but diethylamine, ethylmethylamine, dimethylamine and the like having a molecular weight of 200 or less may be exemplified, and the amount of the secondary amine may be added to the reactant of the polymer polyhydric alcohol and organic diisocyanate. It is preferable to make it 0.9-1.5 by equivalent ratio with respect to the isocyanate group which exists. The end of an isocyanate group turns into a secondary amine terminal by reaction with said secondary amine. When the secondary amine ends are subjected to high heat in the spinning process, the secondary amines fall off and are converted to the isocyanate ends to form crosslinks, thereby increasing the stress retention.

In the present invention, the polymer additive is added in a weight ratio of polyurethane polymer: polymer additive = 97: 3 to 70:30. If the polymer additive is added in less than a given range of content does not exhibit the effect of the present invention, if used in excess of the given content of the range can not produce a spandex fiber by an abnormal reaction such as gel formation.

The polyurethane polymer used in the present invention is prepared by reacting organic diisocyanate and polymer diol to prepare a polyurethane precursor as known in the art, and then dissolving it in an organic solvent and reacting with diamine and monoamine. do.

The organic diisocyanate that may be used in the production of the polyurethane polymer in the present invention may be selected and used the same as those used in the above-described polymer additives, the polymer diol is not particularly limited, but polytetramethylene ether Glycols, polypropylene glycols, polycarbonate diols and the like can be used.

The diamines are used as chain extenders, ethylenediamine, propylenediamine, hydrazine and the like can be exemplified, the monoamine can be used as chain terminators, diethylamine, monoethanolamine, dimethylamine and the like can be exemplified. have.

Examples of the organic solvent that can be used in the composition for spandex of the present invention include dimethylformamide, dimethylacetamide, and the like, and materials generally used as solvents of polyurethanes.

In the preparation of the spandex fiber by the composition for the spandex fiber of the present invention, the polymer additive is added to the above-mentioned amounts, and the polyurethane polymer is mixed to proceed with the reaction, and then crosslinked through the post-polymerization reaction in the storage process and the spinneret. By spinning in a conventional manner.

The present invention may be better understood by the following examples, which are intended to illustrate the present invention and are not intended to limit the protection scope of the present invention.

Example 1

Preparation of Polyurethane Polymer

200 g of diphenylmethane-4,4'-diisocyanate and 810 g of polytetramethylene ether glycol (molecular weight 1800) were added to the reactor, and reacted with stirring at 90 ° C. for 90 minutes in a nitrogen gas stream. Urethane prepolymer was prepared. After the polyurethane precursor was cooled at room temperature, 1600 g of dimethylacetamide was added thereto and dissolved to obtain a polyurethane prepolymer solution.

Subsequently, 19 g of ethylenediamine and 3 g of diethylamine were dissolved in 300 g of dimethylacetamide and added to the prepolymer solution at 5 ° C. to obtain a polyurethane polymer solution.

Preparation of Polymer Additives

250 g of diphenylmethane-4,4'-diisocyanate and 1000 g of polypropylene triol (molecular weight 3000) were charged to 750 g of dimethylacetamide in a reactor, and the mixture was reacted with stirring at 90 DEG C for 90 minutes in a nitrogen gas stream. % And isocyanates at the ends. While stirring the solution, a solution in which 225 g of diethylamine was dissolved in 725 g of dimethylacetamide was slowly added thereto to prepare a polymer additive solution having a terminal ending with a diethylamine group.

spandex  Manufacture of fibers

The polymer additive solution was mixed with the polyurethane polymer solution so as to have a solid content ratio of 80:20, and degassed to prepare a composition for spandex fibers, and the spinning temperature was adjusted to 250 ° C. in a dry spinning process using this as a spinning stock solution. An elastic yarn of filament 40 denier was prepared.

[Example 2]

A polyurethane elastic yarn was manufactured in the same manner as in Example 1 except that the polyurethane polymer solution and the polymer additive solution were added so that the solid content ratio was 90:10.

Example 3

A polyurethane elastic yarn was manufactured in the same manner as in Example 1 except that the polyurethane polymer solution and the polymer additive solution were added so that the solid content ratio was 95: 5.

Comparative Example 1

A polyurethane elastic yarn was manufactured in the same manner as in Example 1 except that the polyurethane polymer solution and the polymer additive solution were added so that the solid content ratio was 50:50.

Comparative Example 2

In preparing the polymer additive solution, a polyurethane elastic yarn was prepared in the same manner as in Example 1 except that glycerol was used instead of polypropylene triol (molecular weight 3000) as the polymer polyhydric alcohol.

[Property evaluation]

Using the INSTRON 5565 of Instron for the polyurethane elastic yarns prepared in Examples 1 to 3 and Comparative Examples 1 to 2, the gauge length was set to 2 inches and five elastic yarn long fiber samples were fixed at 500 mm / min. After 5 cycles of extension between 0 and 300% at the drawing speed, the ratio of the stress at contraction (S2) to the stress at stretching (S1) at 200% at the 5th extension is expressed as a percentage as the stress retention rate. It was.

Stress Retention Rate (%) = S2 / S1 × 100

Table 1 shows the stress retention measured as described above.

As can be seen in Table 1, it can be seen that the polyurethane elastic yarns of Examples 1 to 3 according to the present invention exhibit excellent stress retention of more than 60%. In contrast, when the polymer additive is used in excess of the weight ratio set forth in the present invention (Comparative Example 1) or when glycerol is used in the preparation of the polymer additive (Comparative Example 2), not only the stress retention rate but also the significant decrease in physical properties are caused. Able to know.

According to the present invention, it is possible to provide an excellent composition for spandex fibers having a high level of stress retention while having good spinning workability without high adhesiveness and high uniformity of solution, which requires excellent resilience against repeated elongation. Can be applied to the product being made.

Claims (5)

70 to 97 parts by weight of a polyurethane polymer; As a composition for spandex fibers containing 3 to 30 parts by weight of a polymer additive solution, The polymer additive solution is prepared by reacting a polymer polyhydric alcohol having three or more hydroxyl groups and a molecular weight ranging from 500 to 7000 with an organic diisocyanate to form an isocyanate group, and then reacting it with a secondary amine. Composition for spandex fiber having retention rate The composition of claim 1, wherein the polymer polyhydric alcohol is selected from polyethylenetriol, polypropylenetriol, and polytetramethylenetriol. The method according to claim 1, wherein the reaction ratio of the polymer polyhydric alcohol and organic diisocyanate used in the preparation of the polymer additive solution is in the ratio of 1: 1.5 to 1: 7 in an equivalent ratio of hydroxy group and isocyanate group. Composition for spandex fibers having a retention rate. The method of claim 1, wherein the secondary amine used in the preparation of the polymer additive solution is a molecular weight of 200 or less added to the equivalence ratio 0.9 to 1.5 with respect to the isocyanate group present in the reactant of the polymer polyhydric alcohol and organic diisocyanate, which is A composition for spandex fibers having an excellent stress retention rate, characterized in that the isocyanate group is reacted with the terminal of the isocyanate group to make all of the isocyanate terminals become secondary amine terminals. The spandex fiber which is 60% or more of the stress retention manufactured using the composition for spandex fibers in any one of Claims 1-4.