JPS60126322A - Manufacture of blended polyurethane fiber - Google Patents

Abstract

PURPOSE:To enable the stable melt spinning of a blended polyurethane fiber, by setting the melt flow rate ratio of a thermoplastic polyurethane to polystyrene within a specific range, and carrying out the melt spinning under a specific spinning condition. CONSTITUTION:The ratio of the melt flow rate of (A) a thermoplastic polyurethane having a melt flow rate of 0.5-10 at 210 deg.C to (B) a polymer composed mainly of polystyrene and having a melt flow rate of 1-5, is set between 0.5 and 10. The melt spinning of the mixture is carried out under the spinning condition to give the ratio of the melt viscosity of the polyurethane before spinning (eta0A) to that of the polyurethane after spinning (etaA) of within 0.7-1.0. The lowering of the elastic property of the fiber can be prevented by this process.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing polyurethane fibers with excellent elastic behavior and polyurethane mixed fibers suitable for producing polyurethane molded products.

Conventionally, melt spinning of a mixed fiber of thermal 0T plastic polyurethane and polystyrene or obtaining a molded product using the mixed fiber has been disclosed in, for example, Japanese Patent Publication No. 47-3532.
No. 4, Japanese Patent Publication No. 47-36811, or Japanese Patent Application Laid-Open No. 48-73514. However, polyurethane is extremely active and unstable at high temperatures, so when attempting to produce mixed fibers by melt spinning, the relationship between the dispersed phase and dispersion medium phase that makes up the fibers is frequently reversed during spinning. Alternatively, the dispersed components may not be uniformly dispersed in the dispersion medium, making it extremely difficult to perform stable spinning.

An object of the present invention is to stably melt-spun polyurethane-based mixed fibers and to produce mixed fibers in which the viscosity of the polyurethane decreases little due to melt-spinning.

That is, the present invention provides a thermoplastic polyurethane (A) with a melt flow rate (MFR-A) of 0.5 to 10 at a temperature of 210°C and a polystyrene-based polymer (B
) Melt flow rate) (MFR-B) of 1 to 5 was selected with an MFR ratio MFR-A/MFR-B in the range of 0.5 to 10, and the polyurethane solution viscosity η- before spinning and after spinning were selected. The ratio vA/loA of polycrethane solution viscosity η4 is 0.
Polyurethane mixed fibers are produced by melt spinning under spinning conditions ranging from 7 to 1.0.

In addition, the melt flow rate (MFR) referred to in the present invention is:
It means the value obtained by converting the amount of polymer steadily extruded using a melt indexer specified in JIS K-6760 at a measurement temperature of 210°C and an extrusion load of 3252 to the amount of extrusion for 10 minutes, and Solution viscosity (η6
, ηOA) means the intrinsic viscosity value measured at 30° C. using dimethyl 7J=lumamide as a solvent.

Thermoplastic polyurethane is a polymer that has an extremely wide range of physical behaviors and exhibits a variety of thermal motions, but in the present invention, it is one of the polymers that can be stably spun by melt-mix spinning with other polymers. As an indicator, selecting a thermoplastic polyurethane with a specific MFH range and combining it with a polymer with a specific MFR range;
The purpose is to carry out melt mixing spinning while satisfying the following two conditions: and the solution viscosity of the thermoplastic polyurethane should be in a specific ratio before and after spinning.

Examples of the thermoplastic polyurethane used in the present invention include polyester glycol obtained by condensation polymerization of glycol and aliphatic dicarboxylic acid, polylactone glycol obtained by ring-opening polymerization of lactam, and aliphatic or/and aromatic polyurethane. A polymer glycol having an average molecular weight in the range of 600 to 3,500 selected from at least one of polycarbonate glycol or polyether glycol, preferably polyester glycol, polylactone glycol, or polycarbonate glycol, is used as a soft segment, and tolylene diincyanate is used as a soft segment. , 4
．． It is a polyurethane obtained by chain extension with an organic diincyanate such as 4-diphenylmethane diincyanate, inphorone diisocyanate, and 4,4'-dicyclohexylmethane diisocyanate, and a low-molecular compound having at least two active hydrogen atoms. And polyurethane (A
) A polyurethane prepared by adjusting the degree of polymerization (viscosity), branching state, type and molecular weight of soft segments, ratio of soft segments to hard segments, etc. is used so that the MFR of the polyurethane is in the range of 0.5 to 10. If the MFR is less than 0.5, the fluidity is low, while the MFR is 10'f! : If it exceeds, the fluidity is high and the stability of the mixed phase is not improved, resulting in poor spinnability.

On the other hand, the polymers mainly composed of polystyrene used in combination with thermoplastic polyurethane in the present invention include polystyrene, a copolymer of styrene and acrylonitrile,
Examples include styrene-based copolymers such as copolymers of styrene and methyl methacrylate, copolymers of styrene and butadiene, copolymers of styrene and α-methylstyrene, and styrene derivatives such as polyα-methylstyrene. It will be done. However, the MFR of the polymer must be in the range of 1-5. The MFR of this polymer may be the value of one type of polymer, or it may be a mixture of two or more types of polymers with different MFH so that the apparent MFR is within the above range.

If the MFR exceeds the above range, the dispersion state with polyurethane becomes non-uniform and spinnability becomes unstable.

The polyurethane blend fiber of the present invention is produced by melt blend spinning. That is, thermoplastic polyurethane (A)
and polystyrene-based polymer (B) in the form of chips or pellets, melted and spun in the same melting system, or melted the chipped or pelleted polymers separately in different melting systems, and then Multicomponent fibers can be produced by statically mixing or dynamically mixing molten polymers, or by forming a mixed system of polymers (A) and (B) in a spinneret and spinning them. In this case, the spinning conditions such as melt spinning temperature, polymer residence time, shear, etc. are set in advance so that the ratio ηA/η of the solution viscosity η% of the thermoplastic polyurethane (A) before spinning and the solution viscosity η4 after spinning is determined. Test conditions are set in the range of 0.7 to 1.0. Under conditions where the solution viscosity ratio is 0.7 or less, the elastic properties deteriorate when fibers are used. On the other hand, under conditions where the viscosity ratio is 1.0 or more, the fiber phase becomes unstable and the yarn quality deteriorates, which is undesirable.

The mixing ratio of the thermoplastic polyurethane (A) and the polymer (B) mainly composed of polystyrene is 30 to 80% by weight, preferably 40 to 70% by weight.
%, 70-20% polystyrene-based polymer
, preferably 60 to 30 inches. Furthermore, thermoplastic polyurethane (A) and a polymer mainly composed of polystyrene (
In the combination B), the relationship between the MFR ratios of both polymers also has a large relationship with the fiber phase and spinnability. That is, MFB- of thermoplastic polyurethane (A) is MFR-
A.

and MF of polystyrene-based polymer (B)
MFR-A/MFR-B when R is MFR-B
It is preferable to select a polymer in the range of 0.5 to 10. Outside this range, the fiber phase becomes unstable, spinnability deteriorates and yarn breakage increases, yarn quality deteriorates and fiber strength decreases.

The multicomponent fiber obtained by melt spinning may be drawn using wet heat or/and dry heat, and may be subjected to heat treatment, crimping, cutting, etc. as necessary.

Next, the embodiments of the present invention will be explained with specific examples.
The present invention is not limited to these examples. Note that parts and parts in the examples refer to weight unless otherwise specified.

Examples 1 to 6 Four types of thermoplastic polyurethanes (A) with different MFR-A were made by reacting polybutylene adipate glycol with an average molecular weight of 2000, 4.4'-diphenylmethane diisocyanate, and 1.4-buta/diol. . When melt-spinning this polyurethane and polystyrene (B), polystyrenes with different MFR-B were selected, 60 parts of thermoplastic polyurethane and 40 parts of polystyrene were mixed in chips, and using a 40%φ extruder, the spinning temperature was 210°C. Melt spinning was performed to obtain mixed fibers. M in this case
Table 1 shows the relationship between FR ratio and spinnability.

J・,・, “Margin Table 1 Furthermore, in the case of polyurethane with MFB6.o, the intrinsic viscosity η- before spinning is 0.94, and the intrinsic viscosity η4 after spinning is 0.7.
7, and its viscosity ratio ηA/77'A is 0.82,
Also MFB2. In the case of O polyurethane, the intrinsic viscosity η0A before spinning is 1.08. Intrinsic viscosity η4 after spinning is 0.9
9, and its viscosity ratio ηA/η- is 0.92, and in the case of polyurethane with Mli″■ζ or 8.6, ηOA
is 0.82 and η is 0.61, and the cross-sectional structure of the fiber obtained in the example was a stable phase in which polyurethane was not a dispersion medium component and polystyrene was a dispersion medium component. The stretchability was good even when stretched 3 times.

On the other hand, in the fibers obtained in the comparative examples, the dispersed phase was unstable, the drawability was poor, and when the fibers were drawn to double the number of yarns, there were many breakages, and the fibers were not of good quality.

Examples 7-8 IVI F R-B at measurement temperature 210°C is 3.5
When spinning 750 parts of polystere and 50 parts of polyethylene adipate polyurethane with MFR-A of 4.5 by melt mixing, the relationship between spinnability and yarn quality (stretchability) when changing the spinning temperature is shown in Table 2. Table 2 In other words, setting the spinning conditions in melt spinning causes a thickening effect on the yarn quality, and decreases the MFR ratio and viscosity ratio.
A filament with good spinnability and yarn quality can be obtained by satisfying the above conditions.

Examples 9-10 Polycarbonate glycol with average molecule-Hlsoo,
Polycarbonate polyurethane (& liquid viscosity ηA1.12, M F ) obtained by reacting inphorone diincyanate and inphorone diamine/hydrazine is also -A
3.5) 55 parts of all styrene-acrylonitrile copolymer (MFR-B 1.5) 45 parts were separately bath-melted in two extruders, statically mixed at the spinning head to form a mixed yarn, and spun. did. Table 3 shows the relationship between spinning conditions and spinnability.

Table 3 In other words, the mixed fibers spun under the conditions of the present invention had a stable fiber phase and good spinnability and drawability.

Patent applicant RiRashi Co., Ltd. Representative Patent Attorney Ken Honda

Claims (1)

[Claims] Thermoplastic polyurethane (A) Nomel) 70-v-to (MFR-A) at a temperature of 210°C
0, the melt flow rate (MFR-B) of the polymer (B) mainly composed of polystyrene is 1 to 5.
The ratio MFR-A/MFR-B is selected in the range of 0.5 to 10, and the ratio ηA/O of the polyurethane solution viscosity f before spinning and the polyurethane solution viscosity η after spinning is selected in the range of 0.7 to 1.0. A method for producing a polyurethane mixed fiber characterized by melt spinning under spinning conditions.