JPS63145439A - Production of coated elastic yarn - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION As a method for manufacturing a vR elastic yarn in which a bulky multifilament is wound as a covering yarn and a twisted yarn is wound as a covering yarn, a method using a covering machine using a hollow spindle;
There are methods such as pulling them together and twisting them together.

However, in these methods, there is a natural limit to the spindle rotation speed, and the bulky textured yarn must be manufactured separately by false twisting mK, resulting in high production costs due to slow production speed and multifaceted processes. There are flaws that cannot be ignored.

Furthermore, a method is known in which polyurethane elastic yarn is aligned with filaments to be covered yarn and simultaneously subjected to Kffl twisting, and is highly productive in that it can be processed at a speed of about 5.100 m/min. However, it is difficult to uniformly coat the polyurethane elastic yarn, and when the polyurethane elastic yarn passes through the false twisting heater in a stretched state, it is heat set or partially heat embrittled, resulting in a decrease in elastic properties. When passing through guides, tensors, etc. during the process,
Since the polyurethane elastic yarn and the bulky textured yarn of the covered yarn separate, there is a drawback that additional twisting is required after false twisting.

Therefore, as a method to improve the coating properties, Japanese Patent Publication No. 50-28586 describes a method in which a groove-shaped guide is provided near the heating start point and the coating threads are aligned under low tension. It is hard to say that the sex is sufficient. Japanese Patent Publication No. 56-5850 describes a method of increasing the false-twisting temperature during the false-twisting process and adhering or fusing polyurethane elastic yarns so that they do not easily separate. There is a risk that the elastic yarn will become thermally brittle and its elastic properties will be significantly impaired.

Furthermore, Japanese Patent Publication No. 10288/1988 describes a composite filament in which a fiber-forming polyamide and an elastic polyurethane are bonded in parallel and crimped into a spiral shape. However, the elasticity of such a wound net is extremely weak compared to that of polyurethane elastic filaments, making it unsuitable for use in fields that require high stretching power. We proposed a method for producing covered elastic yarns in which a mixed yarn obtained by melt-spinning a polyurethane elastic material from the center of a plate and a thermoplastic fiber-forming polymer from the outer periphery is drawn and false-twisted. However, the polyurethane elastic filament has uneven thickness in the longitudinal direction and has a fine denier, for example, a single yarn of 15 d.
There still remained the problem that the following items could not be manufactured with good operability.

The purpose of the present invention is to eliminate the drawbacks of such conventional methods, and to easily and efficiently produce coated elastic yarns having polyurethane elastic filaments with fine denier and excellent uniformity, and having excellent covering properties and elastic properties. After melt-spinning a polyurethane elastomer component and a polyurethane elastomer component mixed with polyorganosiloxane or a modified product thereof if necessary, the resulting composite yarn is aligned with a thermoplastic multifilament and subjected to a drawing false twisting process. This is a method for producing a covered elastic yarn consisting of a bulky multifilament and a polyurethane elastic filament, which involves splitting the composite yarn into two components and performing composite spinning.

The thermoplastic polyurethane elastomer applied to the present invention contains a known segmented polyurethane copolymer, and contains polyols having a molecular weight of 500 to 6,000, such as dihydroxy polyether, dihydroxy polyester, dihydroxy boricton, dihydroxy polyester amide, dihydroxy carbonate, and the like. block copolymers, etc., and organic diisocyanates with a molecular weight of 50 Q or less, such as P, P-diphenylmethane diisocyanate, tolylene diisocyanate, hydrogenated P, ? diphenylmethane diisocyanate, tetofumethylene diisocyanate,
It is a polymer obtained by reacting hexamethylene diisocyanate, isophorone diisocyanate, P,5-naphthylene diisocyanate, etc. with a chain extender such as water, hydrazine, diamine, glycol, etc. Among these polymers, particularly preferred are a polyether type using polytetramethylene ether glycol as the polyol, a polycabrolactone type using polycaprolactone glycol, and a reaction product of 1,6-hexanediol and phosgene. The polyurethane elastomer is a polycarbonate type used, a polyester type using polybutylene adipate, or a copolymer or mixture thereof.

Moreover, P,P-diphenylmethane diincyanate is suitable as the organic diisocyanate. Glycols are preferred as the chain extender, with 1,4-bis(β-hydroxyethoxy)benzene and 1,4-butanediol being particularly preferred.

As described above, the thermoplastic polyurethane elastomer used in the present invention is, in principle, a polymer synthesized without using a branching agent or a crosslinking agent. Therefore, the spinning temperature can be kept at a low level, and thermal deterioration of polyurethane can be suppressed.

Of course, polymers containing branching or crosslinking to the extent that the spinning temperature is not extremely high can also be suitably used.

Generally speaking, melt-spun polyurethane elastic yarns often have insufficient elastic properties at high temperatures, but in the method of the present invention, the molecules are By adding and mixing a polyisocyanate compound having a molecular weight of 400 or more, a polyurethane elastic yarn with improved elastic properties can be obtained.

The amount of the polyisocyanate compound of the present invention added is preferably 8 to 20% (by weight), particularly preferably 5 to 15% (11i )%.

If the amount added is less than 8%, the expansion and contraction properties at high temperatures will be insufficient, while if it exceeds 20%, the melt viscosity of the polyurethane elastomer component will decrease significantly, resulting in unstable spinning, which is not preferable.

Although it is possible to use a mixer having a rotating part in the part where the polyisocyanate compound is added to the molten thermoplastic polyurethane elastomer, it is more preferable to use a mixer having stationary trackside elements. That's true. A known mixing device having a static crosstalk element can be used. It is important that the shape and number of elements of the static kneading element be designed so that mixing of the polyurethane elastomer and the polyincyanate compound is sufficiently completed before they are discharged from the nozzle.

When the polyisocyanate compound is added and mixed, by leaving the wound undrawn yarn at room temperature for one day or more, the branching due to allophanate bonds between the polyurethane and the polyisocyanate compound or the formation reaction of a crosslinked polymer progresses and is completed. The quality and thermal performance of the elastic yarn are improved.

The polyisocyanate compound with a molecular weight of 400 or more applied to the above method includes a polyol with a molecular weight of 800 to 2,500, such as at least one polyol selected from the group consisting of polyether, polyester, polyester amide, and polycarbonate, and an organic compound with a molecular weight of 500 or less. Examples include incyanate-terminated compounds obtained by addition reaction with diincyanate. Particularly suitable polyols include polytetramethylene ether glycol, polycablocktone or polybutylene adipate. Further, as the organic diincyanate, P,P-diphenylmethane diisocyanate is preferable.

In addition, polyurethane elastic yarn produced by melt spinning often causes yarn breakage due to poor unwinding due to the threads sticking together on the bobbin, so in the method of the present invention, if necessary, organic siloxane Alternatively, an undrawn yarn with improved unwinding property can be obtained by combining the parent substance and waxes and then performing composite melt spinning.

Suitable organic siloxanes include polyorganosiloxanes such as dimethylpolysiloxane, methylphenylpolysiloxane, and diphenylpolysiloxane, and polyether-modified products, alkyl-modified products, and alcohol-modified products thereof. The addition amount of the polyorganosiloxane or modified product thereof of the present invention is preferably 0.1 to 5% by weight, particularly preferably 0.5 to 8.0% by weight. If it is less than 0.1% by weight, the desired anti-sticking properties will be insufficient, while if it exceeds 6% by weight, the thread will become too slippery and the yarn will break on the winding grain bin. This is not preferable since the resulting particles also deteriorate the homogeneity and dispersibility, resulting in unstable spinning.

Thermoplastic fiber-forming polymers applicable to the present invention include polyamides such as nylon 6, nylon 66, nylon 6101, nylon 11, nylon 12, and copolymers containing these as main components, polyethylene terephthalate, polybutylene terephthalate, Polyesters such as polyoxyethylene benzoate and copolymers based on these, polyolefins such as polypropylene, polyethylene and copolymers based on these, thermoplastics that can be melt extruded and have fiber-forming molecules. Examples include main polymers and copolymers.

Usually, the melting temperature of thermoplastic polyurethane elastomer is 190
-240°C, especially 200-280°C is preferred. Therefore, the melting temperature of the thermoplastic fiber-forming main body that is simultaneously discharged is also 1.
It is desirable that the temperature be 90 to 240°C. From this point of view,
Thermoplastic fiber-forming polymers include nylon 6, polypropylene, polybutylene terephthalate with a relatively low melting point, or copolymers whose main components are nylon 6, nylon 66, polyethylene terephthalate, polybutylene terephthalate, and polypropylene with a melting point. is preferably 220°C or less, particularly 210°C or less.

Melt spinning in the method of the present invention is carried out using a composite spinning apparatus equipped with the same equipment as for adding and mixing the polyisocyanate compound, which optionally adds and mixes organosiloxane or its modified product to the polyurethane elastomer component in a molten state. It can be applied by +. If it is necessary to melt extrude the thermoplastic fiber-forming polymer at high temperatures, the heating temperature up to the spinning head is set high, e.g. 275-290°C for polybutylene terephthalate; The melting temperature of the thermoplastic polyurethane elastomer is 240℃.
It is necessary to set the temperature so that the temperature does not exceed 0.degree. C. and the thermoplastic fiber-forming polymer does not solidify. For example, in the case of polybutylene terephthalate, the heating temperature of the spinning head is preferably 286 to 250°C. Furthermore, the residence time until the molten polymer is discharged from the spinning head,
It is preferable to decide the shape of the eye pack by taking into consideration the heating method and the like. When discharging from a nozzle while maintaining a temperature difference between both molten polymers, it is preferable to use a fence with a length that allows the residence time in the nozzle pack. For example, it is effective to provide a filter for the molten polymer before it enters the spinning head, rather than in the die pack.

The composite yarn of the present invention can be spun using a known side-by-side type or radial type composite spinneret. In order to stably discharge the polymer from the spinneret, it is preferable to compositely spin the two components so that the composite shape has an axis of rotational symmetry. In cases where the composite yarns stick to each other after being spun and wound, it is advantageous for the polyurethane elastomer component to occupy a surface weight ratio of 15% or less on the fiber surface of the composite yarn. In composite yarns, for example, first to
In Figure 3, the polyurethane elastic component exposed on the fiber surface is thin (it is easy to do so), and the surface area ratio is 10.
% or even more preferable composite yarns of 5% or less can actually be obtained.

The composite yarn discharged from the nozzle is air-cooled, applied with an oil agent, and then wound up by a known method. In order to reduce mutual adhesion and unwinding resistance of the composite yarns, it is a good idea to apply a known oil agent having anti-adhesion properties.

Particularly suitable oil agents include mineral oil or silicone oil such as dimethylpolysiloxane or methylphenylpolysiloxane, which is supplemented with polyether-modified silicone G (0.5 to 2% by weight). and/or a /L13 agent containing a diamine represented by formula 11 (0.1 to 101%).

(R1, 几2, 几8 are alkyl groups having 1 to 5 carbon atoms; (represents an optional alkylene group or an alkyl ether group having 4 to 5 carbon atoms).

In the method of the present invention, the composite yarn obtained by composite spinning is aligned with a thermoplastic multifilament and subjected to a drawing/false twisting process). An elastic yarn consisting of polyurethane elastic filaments is produced.

In order to obtain a uniform coated elastic yarn in which the polyurethane elastic yarn is arranged in the center and the covered yarn in the outer periphery, a bulky multifilament (including split filaments of a thermoplastic fiber-forming polymer component) to be the covered yarn is used. ) is preferably 10 or more filaments, and the denier ratio to the covered elastic yarn denier is 60% or more.

In the stretch false-twisting process of the method of the present invention, a conventional out-of-the-way one-type stretch false-twisting apparatus can be used as is. However, the polyurethane elastic filament of the present invention is produced by melt spinning, and the heat resistance limit of the drawn Ni properties is lower than that of those produced by dry spinning or dry spinning, so it is necessary to set the false twisting temperature low. The false twisting temperature is preferably 180° C. or lower, and can be determined by taking into account the composite shape of the composite yarn and the false twist crimp characteristics of the covered yarn.

The conventional method of producing coated elastic yarn by aligning polyurethane elastic yarn and coated yarn and false twisting requires active feeding of the polyurethane elastic yarn, which makes the equipment complicated and difficult to operate. It becomes strange.

In particular, the feeding speed of polyurethane elastic yarn is 150 m/
If it exceeds 1 minute, it becomes extremely difficult to start. On the other hand, in the present invention, the polyurethane elastic component is already covered with composite yarn and thermoplastic multifilament before stretching and false twisting. It is possible to process at higher speeds.

(Effects of the Invention) According to the method of the present invention, fine deniers, for example, single yarns of 15 deniers, which have not been put to practical use in conventional single melt spinning,
A coated elastic yarn having polyurethane elastic filaments of 10 denier or 7 denier can be produced with good operability.

Secondly, according to the conventional method, the presence of thickness unevenness in the fiber diameter in the longitudinal direction of the fiber was unavoidable in fine denier polyurethane elastic filaments, but with the method of the present invention, the presence of thickness unevenness in the fiber diameter is unavoidable. It is possible to obtain uniform polyurethane elastic filaments without any cracks, and it is possible to reduce troubles such as thread breakage in post-processing. In addition, defects such as warp lines are reduced in knitted fabrics, and products of excellent quality can be provided.

Eighth, the polyurethane elastomer component is protected by a thermoplastic fiber-forming polymer component in the composite yarn,
Therefore, it is possible to produce a 14L elastic yarn of JJij, which has excellent elastic properties, since there is less embrittlement during stretching and temporary processing.

Fourth, what previously required separate melt-spinning bags for polyurethane elastic filaments and coated yarns can be replaced with a single melt-spinning device.

Furthermore, there is no need for a feeding device for the polyurethane elastic filament (a special pulling device such as a gong or a tension adjustment device), and normal stretching and false twisting processing can be applied as is.

Fifth, compared to conventional single spinning of polyurethane elastic filaments, the spinning speed can be increased to 60%, which is similar to that of nylon or polyester.
The speed can be increased to 00 to 1500 m/min. This also greatly reduces the residence time of the polymer in the spinning bag [4], which has a large difference in the appropriate melting temperature between the two.
Works advantageously in spinning component polymers.

In the method of the present invention, the process is greatly simplified and the speed can be increased, so the production cost is also extremely low compared to the conventional method. Further, the obtained covered elastic yarn has the advantage of having excellent properties not found in the past.

(Example) The present invention will be explained below with reference to Examples. Part in Examples, %
represents approximately parts by weight or % by weight.

The unwinding property of the spun and wound composite yarn is determined by the unwinding yarn breakage rate (unwinding fitl
k, 9). Shin! ! Elastic modulus is JISL1090
-1970 method. Operability is the yarn breakage rate (weight Ill) in the drawing false twisting process.

(However, unraveling thread breakage was excluded).

Example 1 Number average molecule! After reacting 1500 polycarbonate glycol and 4.4-diphenylmethane diisocyanate at a molar ratio of 1:8.5, NCO and OH
fi(7) 1,4-butanediol having a ratio of i and oa was reacted to obtain a polycarbonate polyurethane elastic body U1 having a hardness of 94.

Using a melt composite spinning device equipped with a section for adding polyorganosiloxane and kneading with a static mixer, 28
The polyurethane elastic body U1 melted at 0°C and 260°C
Nylon 6 (relative viscosity 2.4) melted at 286℃
A composite yarn of 2 filaments of 70 denier was spun at a winding speed of 800 m/min. The single yarn has a shape as shown in Fig. 1 and is made of polyurethane elastic material component (4) equivalent to lθ denier and nylon 6 equivalent to 14 denier.
It was a composite yarn in which two components (1) were joined, and the surface area ratio of the polyurethane elastic component was 5%. Further, as a spinning oil agent, an oil agent (segmentation 16%) prepared by mixing 10% polyethylene oxide-modified silicone (80° C., 100CS) in mineral oil with a viscosity of 50 seconds was applied, and 1.2% was applied to the composite yarn.

Next, nylon 6 (relative viscosity 2.4) was rolled up at a speed of 80
Multi-fiftment undrawn yarn 170 spun at 0 m/min
The denier 24 filament and the above composite yarn are drawn and drawn and false twisted.The conditions are a draw ratio of 8.4G and a false twisting temperature of 15.
0℃, false twist feed rate +0.8%, spindle rotation speed 2
A coated elastic yarn (invention 1) was produced at 76,000 rpm (false twist number: 8,800 T/m).

Example 2.8 In Example 1, polycaprolactone glycol was converted to polytetofumethylene glycol with molecule ff 11500 (
(i.e., using a polyether-based polyurethane elastomer) and a polycarbonate glycol having a molecule of mt6oo (i.e., using a polycarbonate-based polyurethane elastomer) to produce a coated elastic yarn (invention 2.8) in the same manner. did.

Example 4 Polycarbonate glycol having a number average molecular weight of 1 soo was reacted with 4,4-diphenylmethane diisocyanate at a molar ratio of 1:2, and the viscosity of 11 was reduced to 10
Coated elastic yarn (invention 8
) was manufactured.

Example 5.6 In Example 8, 0.8% of polydimethylsiloxane (viscous & 1000cs) was added to the polyurethane elastomer component.
A coated elastic yarn (invention 4.5) was produced in the same manner except that 1.5% was added and mixed.

Comparative Example 1 A 20-denier monofilament of the polyurethane elastic body U1 used in Example 1 was spun according to a conventionally known method, but the spun yarn breakage rate was poor at 18%. Then,
As in Example 1, 170 denier 24 filaments of nylon 6 were aligned and drawn and false twisted to produce a covered elastic yarn (Comparative Example 1).

Next, an attempt was made to spin 20 denier 2 filaments using the polyurethane elastic body U1, but the spun yarn breakage rate was extremely poor at 21%, and the unraveled yarn breakage rate was 46%.

The drawing and false twisting conditions, unwinding properties, workability, and yarn properties of these coated elastic yarns are the first! l! Shown below.

The coated elastic yarn of the present invention had excellent unwinding properties and workability, as well as less breakage of polyurethane elastic filaments and excellent stretch elasticity, compared to comparative examples made by conventionally known methods.

1st Surface Projection Example 7 Using the coated elastic yarns of inventions 1 to 6, 100 pieces of tights were made on a stocking knitting machine with 400 stitches, a valley diameter of 88/4 inches, and a rotation speed of 800 times/min. I made a prototype of the legs. All of the obtained tights had no swelling and had good stretching power.

On the other hand, using the covered elastic yarn of Comparative Example 1, 100 pairs of tights were knitted in the same manner as above. The obtained tights had not only visible breakouts with the naked eye, but also core thread breakage of the polyurethane elastic yarn at an average rate of 1.52 pieces/foot, and the stretching power was insufficient. It is presumed that this is because the U-exposed portions of the polyurethane elastic yarns were severely damaged by the false twisting heater, and the polyurethane elastic yarns were broken or damaged during the knitting process.

[Brief explanation of the drawing]

1 to 8 are cross-sectional views of a two-component composite yarn suitable for the It elastic yarn of the present invention. In the figure, A indicates a polyurethane elastomer component, and B indicates a thermoplastic & thin-forming polymer component.

Claims (9)

[Claims] (1) After melt-spinning a thermoplastic fiber-forming polymer component and a polyurethane elastomer component mixed with polyorganosiloxane or its modified product if necessary, the resulting composite yarn is pulled together with a thermoplastic multifilament. A method for producing a covered elastic yarn comprising a bulky multifilament and a polyurethane elastic filament, the method comprising dividing the composite yarn into two components by drawing and false twisting the yarns together. (2) The thermoplastic fiber-forming polymer is nylon 6, polypropylene, polybutylene terephthalate, or a copolymer mainly composed of nylon 6, nylon 66, polyethylene terephthalate, polybutyterephthalate, or polypropylene, and has a melting point of 220°C or less The method according to claim 1. (3) The method according to claim 1, wherein the polyorganosiloxane or a modified product thereof is dimethylpolysiloxane, methylphenylpolysiloxane, or a polyether modified product of polyorganosiloxane. (4) The method according to claim 1, in which the polyurethane elastomer component occupies a surface area ratio of 15% or less on the fiber surface of the composite yarn. (5) The method according to claim 1, wherein the two components are composite-spun so that a rotational symmetry axis exists in the cross-sectional shape of the composite yarn. (6) The method according to claim 1, wherein the thermoplastic multifilament is made of the same polymer as the thermoplastic fiber-forming polymer. (7) The method according to claim 1, wherein the false-twisting temperature in the stretch false-twisting process is 180°C or less. (8) The method according to claim 1, wherein the polyurethane elastic filament has a single yarn fineness of 15 deniers or less. (9) Bulky multifilament (
The method according to claim 1, wherein the number of filaments of the thermoplastic fiber-forming polymer component (including split filaments) is 10 or more, and the denier ratio to the denier of the covered elastic yarn is 60% or more.