JPS5898421A - Production of polyurethane elastic yarn - Google Patents

Abstract

PURPOSE:A reaction product from a polyisocyanate and a blocking agent is added to a polyurethane elastomer and they are made into filaments and the resultant filaments are heat treated at a specific temperature to produce the titled elastic yarn with high recovery from deformation at high temperatures. CONSTITUTION:A melted thermoplastic polyurethane elastomer, preferably made from a polytetramethylene glycol of 500-6,000 molecular weight, p,p'-diphenyl- methanediisocyante and 1,4-butanediol as a chain extender, is combied with a reaction product between a polyisocyanate of 400 or more molecular weight, preferably p,p'-diphenylmethane diisocyanate adduct to polytetramethylene glycol on both terminals and a blocking agent as a compound with active hydrogens such as phenol, preferably by 5-20wt%. The resultnat mixture is spun into filaments and they are heat treated at a temperature over 80 deg.C, preferably high or than 100 deg.C to give the objective elastic yarn.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing elastic polyurethane yarn, and more particularly to a method for producing elastic polyurethane yarn with excellent heat resistance using melt-spinning methods.

In general, a warm spinning method or a dry spinning method is used to produce polyurethane elastic yarns, and there are relatively few cases where a melt spinning method is used. This is because when melt-spinning a polyurethane elastomer, it is generally difficult to operate stably for a long time because the polyurethane elastomer has poor thermal stability when #11 is used. This is thought to be due to the problem that elastic yarn has poor heat resistance and insufficient recovery from deformation at high temperatures.

Several methods have been proposed to improve the performance of urethanes obtained by melt spinning.

For example, Japanese Patent Publication No. 44-20247 proposes a method of adding a special polyfunctionalized metal during the synthesis of polyurethane. Furthermore, Japanese Patent Publication No. 7426/1983 proposes a method of synthesizing polyurethane using a polyfunctional polyol and melt-spinning the resulting polyurethane.

However, the method of improving the heat resistance of polyurethane elastic yarn by imparting cross-linking to polyurethane using these polyfunctionalized metals shows that when sufficient cross-linking is imparted to improve the heat resistance, poly! - Since the Sm temperature becomes high, it is necessary to raise the spinning temperature. As a result, polyurethane tends to undergo thermal decomposition and spinning becomes unstable, making it extremely difficult to put it into practical use industrially.

An object of the present invention is to provide an elastic polyurethane yarn with excellent recovery characteristics from deformation at high temperatures.

Another object is to provide a method for producing such polyurethane elastic threads in a stable and industrially advantageous manner.

In the method of the present invention, when melt-spinning thermoplastic polyurethane, a reaction product of a polyisocyanate compound having a molecular weight of 400 or more and a sequestering agent is added to and mixed with the polyurethane elastomer, which has been melt-spun, and nine filaments are obtained by spinning. It is characterized by heat treatment at a temperature of 80°C or higher.

The thermoplastic polyurethane elastomer used in the present invention contains a known segmented polyurethane copolymer, and includes a polyol having a p1 molecular weight of 500 to 6,000, such as dihydroxy polyether, dihydroxy polyester, dihydro cypolylactone, dihydroxy polyester ardine, etc. .

Dihydroxypolycarbonates and their polypropylene copolymers and organic diisocyanates having a molecular weight of 500 or less, such as P,P'-di7-diphenylmethane diinocyanate, tolylene diisocyanate, water-enriched p,p'-diphenylmethane diisocyanate, Tetomethelene diinocyanate, hexamethylene diisocyanate, isophorone diisocyanate, 1,5-7 ethylene diisocyanate, etc. and a chain extender having a molecular weight of 500 or less, such as water,
It is a polymer obtained by reaction with hydrazine, diamine, glycol, etc.

Among these polymers, particularly preferred are polymers using polytetramethylene glycol, polycaprolactone, or polybutylene adipate as the polyol. In addition, organic diisocyanates include P,
P'-diphenylmethane diinocyanate is preferred. Glycols are particularly suitable as the chain extender, and p, p
'-bishydroxyethoxybe/and 1,4 butanediol are preferred.

As described above, in the present invention, a polymer synthesized without using a monobranching agent or a crosslinking agent can be used as a thermoplastic polyurethane as a spinning raw material. Therefore, the spinning temperature can be kept at a low level, and thermal deterioration of polyurethane can be suppressed. Of course, IJ w- containing branched or crosslinked St, which does not cause the spinning temperature to be extremely high, can also be suitably used.

The method for synthesizing the thermoplastic polyurethane used in the present invention is to first react a polyol with an organic diisocyanate compound and then react with a chain extender. Both methods can be adopted.

Although it is possible to use a solvent or diluent during polymer synthesis, it is possible to use a solvent or diluent during polymer synthesis, but it is also possible to use a solvent or diluent during polymer synthesis. - It is more suitable to carry out bulk polymerization in order to produce berets.

Preferred methods for bulk polymerization include a method of continuously or semi-continuously collecting the polymer using an extruder, or a method of obtaining a powder or lake-like polymer by patch reaction.

In the present invention, boryl-lemene in which the polymer synthesis reaction has been fully completed can be used as a spinning raw material. In the field of polyurethane elastomer products, this is a so-called incomplete thermal cycle elastomer.

In other words, a method is known in which pellets in which some of the isocyanate groups remain and some of the active groups are used to cause crosslinking after production.However, such pellets have the problem that they are easily deteriorated by exposure to heat and temperature during storage. There is a point. In the present invention, although it is possible to use such an incompletely thermoplastic elastomer, a thermoplastic polyurethane that has undergone a complete reaction is preferably used for the above-mentioned reasons.

The reaction product of a polyisocyanate with a molecular weight of 400 or more and a capping agent applied to the present invention is stabilized by addition reaction with a NOO group Kl chaining agent of a polyinocyanate compound.

The NGO group is dissociated by heating. The polyisocyanate compound is a compound having at least two isocyanate groups in one molecule.

For example, it can be synthesized by reacting a polyol with a molecular weight of 500 to 2,500 used in the synthesis of polyurethane elastomer with an organic diisocyanate with a molecular weight of 2111 molar weight of 500 or less *1 * Having 5 or more hydroxyl groups as a polyol Compounds can also be used.

Further, as the polyinocyanate compound, a dimer of organic diisocyanate or a carposiindo-modified polyinocyanate can also be suitably used.

The number of isocyanate groups having Kt in one molecule of the polyinocyanate compound is preferably 2 to 4, and diisocyanate compounds are particularly preferred.

If the number of inocyanate groups is too large, the viscosity of the polyinocyanate compound increases, making it difficult to handle.

A suitable polyisocyanate compound has a molecular weight of 50
0-2500, such as at least one polyol selected from the group consisting of polyether, polyester, polyester amide, and polycarbonate, and an organic diisocyanate compound having a molecular weight of 500 or less added to both ends thereof.

As a polyol suitable for %, polytetramethane/
Examples include glycol, polycaprolactone or polybutylene adipate. In addition, as an organic diisocyanate,
p,p'-diphenylmethane diisocyanate is preferred. The polyisocyanate compound has a molecular weight of 400 or more, preferably 800 to 301 JLl. The molecular weight of the polyisocyanate compound used in the present invention is the apparent molecular weight calculated from the incyanate group weight measured by amine titration.

As the blocking agent to be reacted with the polyisocyanate, a heavy hydrogen compound that undergoes an addition reaction with inocyanate groups is used. For example, phenol, ε-cagrolatatum, α
-pyrrolidone, ethyl acetoacetate, diethyl malonate,
Examples include phenols, lactams, esters, aromatic secondary amines, amides, and tertiary alcohols having active hydrogen such as diphenylamine, acetamide, and C-butyl alcohol.

The reaction between these capping agents and the polyinocyanate compound is carried out using a monkey that has synthesized the polyinocyanate compound, and a reactor that is reacted once at room temperature by adding not more than twice the mole of the capping agent. The obtained reaction product may contain unreacted polyisocyanate compounds.

Addition of the blocked polyinocyanate compound (reaction product) of the present invention, 3 to 30 (weight*) is suitable, and particularly preferably 5 to 20 (by weight).

Although the amount added varies depending on the type N of the blocked polyisocyanate compound used, the amount added is not preferable because it causes uneven mixing, deterioration of yarn quality during spinning, and unstable spinning.

By using the polyinocyanate compound #dIJ in a blocked manner according to the method of the present invention, the following effects can be obtained as compared with the method using the Kyosho polyinocyanate compound.

1. Stability of polyisocyanate compounds during storage is improved.

2. Contamination of the kneading section of the spinning system and the walls of the Hyakujudobe Pass is reduced, increasing the life of the equipment**.

5. The physical properties of the mixture in bath #a during spinning become stable, so that spinning operability is improved.

The melt spinning of the present invention is preferably carried out in a spinning apparatus equipped with a section for melt extruding the thermoplastic polyurethane elastomer, a section for adding and mixing the capped polyisocyanate compound, and a spinning head. As such a spinning device.

Known equipment used to add modifiers during spinning can be used.

In the part where the polyincyanate compound is added to and mixed with the molten polyurethane, there is a WLT that covers the rotating part.
-Although it is possible to use, it is more preferable to use a mixing device with static crosstalk elements. A known mixing device having a static crosstalk element can be used. The shape and number of elements of the static kneading element will vary depending on the conditions of use, but it is important to ensure that the polyurethane elastomer and the blocked polyinocyanate compound are sufficiently mixed at 1 mK before being discharged from the spinneret. It is important to trace it.

An example of the form of the main #4 disbursement will be explained below.

A pellet of thermoplastic polyurethane elastomer is fed from a hopper and heated and melted in an extrusion-like manner.

The melt 1111 temperature is preferably in the range of 190 to 23CJC. On the other hand, the sealed polyisocyanate compound should be defoamed in advance at a temperature of 100°C or less in the supply tank.If the temperature is too high for the melting temperature, deformation of the sealed polyisocyanate compound is likely to occur, so it must be melted within the range that can be melted. A lower temperature is preferable, and a temperature between 100°C and 100°C is used as appropriate.

The melted tllJ chain isocyanate compound eyelid was weighed using a weighing bonder and weighed 1g! Then, it is filtered through a filter and added to the molten polyurethane in a condenser section provided at the tip of the extruder. The capped polyisocyanate compound and the polyurethane are mixed by a mixing device having static kneading elements, and the mixture is metered by a bong and spun into yarn.

There are 4 people in the room @The spinning head is equipped with normal synthetic fiber spinning equipment.
may be used, but it is preferable to arrange the mixture in a shape with as little ura and w capital as possible.

After removing the S material by Flit of gold or glass beads in one layer provided in the spinning head, the μ mixture is discharged from the spinneret, cooled in air, and coated with oil. Normally 500-1500 wa/ll1
n is used.

In the present invention, since the spun urethane yarn does not have sufficient crosslinking as it is, recovery from elongation at high temperatures is insufficient. By heat-treating the fixed-length yarn after spinning at a temperature of 80°C or higher without tension, the crosslinking density increases and a urethane yarn with excellent heat resistance can be obtained.The heat treatment temperature must be 80°C or higher, especially 100°C. The above is preferable ◎ The higher the temperature, the faster the effect can be obtained, but urethane threads will stick at temperatures above 150°C, so temperatures above 150°C are inappropriate and inappropriate. Mouth heat treatment time is preferably at least 10 minutes, and particularly preferably at least KSO minutes. It is.

The heat treatment of the present invention can be carried out continuously or discontinuously.

For example, the objective can be achieved by processing the spinning bobbin as it is in a heated atmosphere. In this case, processing time is required until the inner and outer layers of the bobbin reach the same temperature. The present invention will be explained below with reference to Examples. Parts in the examples represent parts by weight unless otherwise specified.

The quality of the urethane thread was determined using a constant speed elongation type tensile tester (tensile elongation at 1, 500% stress) using a sample length of 5-1 and a tensile speed of 1000.
%/win, the O elongation flea recovery rate is the recovery rate after 100% elongation using a constant speed elongation type tensile tester, immediately removing the bamboo weight and leaving it for 5 minutes. performance t-represented.

The 160° C. heat setting rate is the setting rate when a 100% elongated sample is left in a thermostatic chamber at 130° C. for 10 minutes. The smaller this value is, the better the heat resistance is.

Example 1 5548 parts of dehydrated polytetramethylene glycol having a hydroxyl value of 102 (all parts below refer to coulometric parts t).
and 1,4-bis(I-hydroxyethoxy)benzene 4
99 parts of P, P,
1,953 parts of p'-diphenylmethane diisocyanate was added and reacted with continued stirring for about 30 minutes to obtain powdered polyurethane, which was formed into pellets by extrusion using dimethylformamide at a humidity adjusted at 25°C. tj! /100CC
A polyurethane elastomer having a relative viscosity of 2.50 was obtained.

On the other hand, 1000 parts of polytetramethylene glycol having a hydroxyl group @ti 112 and 500 parts of p,p/-diphenylmeth-7 diincyanate were reacted at 80° C. for minutes under SO to obtain a viscous polyinocyanate compound. The isocyanate group content of this product was 560%, and the molecular weight calculated from this was 1,500. 150P of ε-cabrolactate was added to 100P of this polyinocyanated metal material and reacted at 80° C. for 30 minutes to block the incyanate groups.

Using the thus obtained pellets of the Kyunetsu-cho Higashi polyurethane elastomer and the blocked polyisocyanate compound as spinning raw materials, a spinning machine equipped with a blocked polyisocyanate compound supply device and a machine having a kneading layer with a tight kneading layer is used. The yarn was spun using a direct @ L Ow* nozzle as the spinneret.

A monofilament of 40 denier was spun at a ms speed of 50G-7mln, and the amount of #chained polyinocyanate food added to the urethane yarn was varied.Table 1 shows the results of spinning. After that, the yarn was left at room temperature for S days, and the yarn quality was then determined. Heat treatment: Immediately after spinning, the #insect bobbin was treated in hot air at 11150° C. for S hours, and then the yarn quality was measured.

Table 1 shows that when the blocked polyinocyanate compound of the present invention is not added, the heat resistance at 130°C and the F rate are large, and the heat resistance is poor. By adding a polyisocyanate compound, making cocoon threads, and further heat-treating, the strength of A can be improved.
It is found that heat resistance is improved.

In addition, if the amount of blocked polyisocyanate compounds is large, the urethane yarn discharged from the spinneret tends to become soft, and the yarn left unused tends to be soft (300%
Although the stress (indicated by stress) also decreased, the heat resistance improvement effect of heat treatment m* also became large.

Yoke Example 2 Ureta 74 obtained in Example 1-5 was heat treated under different conditions and the results are shown in the 2nd INK.The heat treatment was carried out in a fixed length in hot air.

From Table 2, it can be seen that the higher the heat treatment ffl temperature is, the more effective it is in improving the 1wI resistance, but if the temperature is too high, the urethane threads will stick.

Example 6 Water 11! 7000 parts of dihydroxypolyε-kabupfucton with a base value of 56, 1,4-bis(β-hydroxyethyl?)
) Using 921 parts of benzene and 2079 parts of p,p'-diphenylmethane diisocyanate, a reaction was carried out in the same manner as in Example 1, and the resulting polymer powder was pelletized using an extruder to produce polyurethane with a relative viscosity of 'L98! A tetrameric beret was obtained.

Further, 1500 parts of dihydroxybolyε-caprolactone having a hydroxyl value of 150 and 1000 parts of p,p'-diphenylmethane diisocyanate were reacted at 80°C to obtain a viscous polyisocyanate compound. The isocyanate content of this product was 6.74% and the molecular weight was 1250. 1 phenol to 2500 g of this polyisocyanate compound
88 parts were added and stirred at 80° C. for 30 minutes to @ chain the inocyanate groups.

The thus obtained nine thermoplastic 1m polyurethane elastic pellets and the chained polyisocyanate compound t-
As a spinning raw material, spinning was performed in the same manner as in Kyouse 1.
Spinning copper thread by changing the amount of polyisocyanate compound added and V! The results are shown in Table 3.The results are shown in Table 3.The results are shown in Table 3. Starting materials are polyurethane and polyester diol with polyester as a soft segment from yarn S6. 4. By the combination of sword chain polyisocyanate metal products. It can be seen that the urethane yarn is heat-treated after spinning and that the urethane yarn has excellent heat resistance.

Actual mψ114 1555 parts of polybutylene adipate with a hydroxyl value of 112,
1.4-butanediol 31 tons 4 parts 1 HiP, P'-
-) 7 x Elmethane diino V anate ttva@ was reacted to obtain a pellet of polyurethane with a relative viscosity of 2.05, and the polyurethane/elastomer, the polyincyanate compound shown in Table 4, and the equimolar amount of the binding agent were reacted. Spinning was carried out in the same manner as in Example 1 using the reaction mixture as the spinning raw material. After heat-treating the obtained urethane thread at 120°C for 2 hours, the quality of the thread is shown in Table 5 and Table 5. If a polyinocyanate compound with a molecular weight of 400 or less is used, the resulting urethane group will be straightened. It can be seen that the width is smaller and the width of the JL becomes thicker.

Applicant Kanebo Co., Ltd. Kanebo Gosen Co., Ltd.

Claims (1)

[Claims] (1) K11iL melt-spun a thermoplastic polyurethane elastic material, and the melted polyurethane elastic material has a molecular weight of 4.
A method for producing polyurethane elastic yarn, which comprises adding and mixing a reaction product of a polyisocyanate compound of 0.00 or higher and a capping agent, and heat-treating the filament obtained by spinning at a temperature of 80° C. or higher. (2) The sequestering agent is phenol, ε-cabroctam,
α-pyrrolidone, ethyl acetoacetate, diethyl malonate, diphenyl acetate, acedeamide, t-butyral 1
The method according to claim 1, wherein the compound is at least one strain selected from the group consisting of Cole. (5) The method according to claim 1, which is carried out using an apparatus equipped with a crystalline alloy static kneading element. (4) Polynato 2 mesolene gelicol, polycaprolactone, polybutylene adipate, in which the polyol forming the thermoplastic polyurethane elastomer has a number average molecular weight of 500 to 1,000. Claims in which the organic diisocyanate forming the thermoplastic polyurethane elastomer is pp'-diphenylmethane diinocyanate aS@method described in item 1 (6) The molecular weight of the polyisocyanate compound is 8o. The method according to claim 1, where the amount of a of claim 11 and the reaction product is 5 to 30 weight X.