JP2869206B2 - Polyester / polyurethane composite elastic yarn - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a core-sheath composite elastic yarn comprising a non-elastomeric copolymerized polyester as a sheath and a polyurethane as a core.

[0002]

2. Description of the Related Art As core-sheath type composite elastic yarn, urethane-urethane type elastic yarn, for example, Japanese Patent Publication No. Sho 61-14245.
Is a polyamide-urethane type composite yarn, for example, Japanese Patent Publication No. 55-27175, Japanese Patent Publication No. 1-18661.
No. 9 is known.

Conventionally, urethane elastic yarns have been applied to various fields utilizing their unique features. However,
This urethane elastic yarn differs from ordinary synthetic filaments in that when unwinding a wound-up filament by fusing and gluing the yarns together, not only an excessive draw tension is required, but also a large tension fluctuation occurs. As an improvement, there is a method using an oil agent. The hot water shrinkage at 100 ° C. of the urethane elastic yarn is not more than 10% at most. As a method of increasing this value, there is a method of performing a stretching treatment under the presence or absence of heat.

[0004]

The urethane-urethane type composite elastic yarn previously proposed by the inventors of the present invention has an urethane sheath, so that the urethane has a sticking characteristic, a high-speed winding property, and the like.
There were difficulties in terms of touch. There was also a problem that mixing with polyester was difficult. In the case of a conventional polyamide-urethane-based composite yarn, the elasticity of the yarn is developed only by performing a crimping treatment, and the yarn itself does not have the elasticity. Furthermore, since a process of producing such a crimp-type yarn requires, for example, a stretching-relaxation treatment, there is a problem that it takes too much time to produce the product. Further, when an oil agent is used for improving the unwinding property, if a certain amount of agglutination is not given to the yarn during spinning, the yarn collapses and long-time winding becomes impossible. Conversely, when the stagnation is caused, troubles in the subsequent process continue, so that there is a problem that it is necessary to introduce a rewinding process. In other words, in order to eliminate sticking at all during spinning, to enable long-time winding, and to make handling of the yarn very easy in the post-process, it is necessary to adjust the oil agent only by using other synthetic fibers. At present, there is no need for such operability.

On the other hand, as a method of increasing the hot water shrinkage of urethane, a method of stretching heat treatment, for example, a method of heating at a temperature of 120 ° C.
When treated under conditions of ~ 3 times, the hot water shrinkage is about 30 ~
It is in the 40% range. However, in the case of a urethane yarn, when this value is measured, the urethane yarn naturally contracts at room temperature, and is hardly set like other synthetic fibers, and handling of the yarn becomes extremely difficult. In other words, there is a problem in terms of dimensional stability because the material naturally shrinks even when no temperature is applied during standing.

Accordingly, a first object of the present invention is to provide a yarn having elasticity and non-stickiness, and a novel composite elastic yarn having improved yarn handling properties in a subsequent process. To offer. Further, a second object of the present invention is to provide a urethane yarn which facilitates handling of the yarn during spinning and provides a high shrinkage by hot water treatment.

[0007]

Means for Solving the Problems The present inventors have determined that the object cannot be attained from the conventional direction, and have conducted research from a completely new direction to complete the present invention.

That is, a first aspect of the present invention is a composite yarn having a sheath made of a copolymer polyester containing ethylene terephthalate as a main component and 12 to 50 mol% of an acid component being isophthalic acid, and a polyurethane elastic body as a core. And a polyester / polyurethane composite elastic yarn, wherein the composite ratio of the sheath / core in the yarn cross section is in the range of 0.01 to 0.30.

Further, the second aspect of the present invention is that terephthalic acid 60 to
A dicarboxylic acid component containing 88 mol% and 12 to 40 mol% of isophthalic acid; 75 to 90 mol% of ethylene glycol and at least one selected from the group consisting of diethylene glycol, triethylene glycol, neopentyl glycol and butanediol; The polyester / polyurethane composite elastic yarn described above, wherein a sheath is a copolymerized polyester obtained from a diol component containing 25 mol%.

The polyester used for the sheath of the present invention comprises an ethylene terephthalate unit comprising a dicarboxylic acid component containing 50 to 88 mol% of terephthalic acid and 12 to 50 mol% of isophthalic acid, and 50 mol% or more of ethylene glycol as a diol component. It is a copolymerized polyester as a main component.

If the isophthalic acid ratio of the acid component exceeds 50 mol%, undesirably, a stiffness phenomenon occurs when the polymer is dried before spinning, and troubles such as sticking after spinning are caused. Conversely, if the isophthalic acid ratio is less than 12 mol%, it becomes difficult to balance the viscosity with the core component during spinning, which is not preferable. Therefore, the range of 15 to 45 mol% is more preferable.

It is possible to add a known polyester modifier such as a matting agent such as titanium, an antioxidant, an antibacterial agent and a dye / pigment to the copolymerized polyester.

Further, in the second aspect of the present invention, if the content of the above-mentioned diol other than ethylene glycol is less than 10 mol%, the shrinkage onset temperature is hardly lowered, so that a favorable effect is hardly obtained. On the other hand, if it exceeds 25 mol%, the decrease in the shrinkage starting temperature becomes too large, and there is a concern that spontaneous shrinkage may occur. If the content of isophthalic acid is less than 12 mol% as a dicarboxylic acid component, the heat shrinkage is not expected to improve as much as expected.
If it exceeds 0 mol%, sticking and poor biting during spinning tend to occur, which is not preferable. The polyester copolymer used in the present invention has a glass transition temperature of 55 to 80 ° C.
Are preferred. If the temperature is lower than 55 ° C., the decrease in the shrinkage starting temperature becomes too large, and there is a possibility that spontaneous shrinkage may occur. On the other hand, if it exceeds 80 ° C., the shrinkage start temperature becomes too high, and it is difficult to obtain the initial effect.

The polyurethane elastic body of the core component constituting the present invention is not particularly limited as long as it is a fiber-forming one, but is preferably a thermoplastic polyurethane or a crosslinked polyurethane. As the thermoplastic polyurethane, there is a polymer which is obtained by reacting a polymer diol with an organic diisocyanate and a chain extender and which can be melt-spun.

Examples of the high molecular diol include ether polyols such as polytetramethylene glycol and polypropylene glycol having hydroxyl groups at both ends and having a molecular weight of 500 to 5,000, polyhexamethylene glycol, polybutylene adipate, polycarbonate diol, polycaprolactone. Glycols such as ester-based polyols such as diols alone or a mixture thereof.

Examples of the chain extender include 1,4-butanediol having a molecular weight of 500 or less, ethylene glycol, propylene glycol, bishydroxyethoxybenzene and the like. Examples of the organic diisocyanate include tolylene diisocyanate (TDI), 4,4'-diphenylmethane diisocyanate (MDI), non-yellowing diisocyanate such as 1,6-hexane diisocyanate, and a mixture thereof.

The hardness of the polyurethane elastic body is 60 to
A range of 98 is preferred. If the hardness is less than 60, it is not preferable because problems such as poor recovery of the obtained composite yarn and poor spinning stability occur. Conversely, if the hardness exceeds 98, the recoverability of the polyurethane itself is inferior and the resilience of the yarn cannot be expected unless a crimped structure is used, and the optimum spinning condition range of the polyurethane having the hardness is extremely narrow. Not preferred. Therefore, the range of 65 to 95 is preferable.

Known polyurethane modifiers such as titanium oxide, dyes and pigments, ultraviolet stabilizers, ultraviolet absorbers, and antibacterial agents can be added to such polyurethanes.

If the composite yarn requires further heat resistance, further recoverability, and the like, a crosslinked polyurethane obtained by reacting a polyisocyanate with the above polyurethane may be disposed in the core component. As a crosslinking method, a method described in Japanese Patent Publication No. 58-46573 proposed by the present inventors, that is, a polyisocyanate is added to and mixed with a molten thermoplastic polyurethane to complete the allophanate crosslinking bond during or after spinning. A method may be used.

The polyisocyanate is a compound comprising a polyol component and an isocyanate component and having two or more, preferably 2-3, isocyanate groups (NCO groups) in the molecule.

As the polyol component, in addition to the above-mentioned diol having a molecular weight of 500 to 4000 used in the synthesis of polyurethane, a compound obtained by mixing a diol and a triol so that the average functionality of hydroxyl groups is 2 to 3 or a functionality of 2 to 3 The synthetic polyol of No. 3 can also be suitably used.

On the other hand, as the isocyanate component, the above-mentioned diisocyanate used in the synthesis of polyurethane, a trimer of an organic diisocyanate, a reaction product of trimethylolpropane and an organic diisocyanate, or an isocyanate having a functionality of 2 to 3 is used. (For example, carbodiimide-modified isocyanate) and the like, and mixtures thereof.

The reaction of the above two components can be carried out by a known method, but the isocyanate group content is excessive, that is, the isocyanate group (NCO group) amount in the reaction product is 2 to 1%.
The reaction is preferably performed so as to be 5% by weight. Of course,
This amount varies depending on the desired physical properties such as heat resistance and recovery properties, and the polyol used.

The amount of the polyisocyanate to be added is preferably in the range of 5 to 40% by weight based on the mixture of the polyurethane used as the core component and the polyisocyanate. The amount added is NCO of the polyisocyanate used.
40% by weight, depending on the group content and type
If the ratio is more than 1, the mixing becomes uneven and spinning becomes unstable, and only unsatisfactory mechanical properties of the yarn are obtained.
Conversely, if the amount is less than 5% by weight, the heat resistance of the desired yarn is insufficient, which is not preferable. Therefore, the range of 10 to 30% by weight is preferable.

In this way, a crosslinked structure mainly comprising allophanate crosslinks is formed in the polyurethane of the core component. In this case, when the crosslinked structure is mainly formed by burette bonding, spinnability is extremely deteriorated, which is not preferable. That is, since the formation rate of buret crosslinking is higher than that of allophanate crosslinking, the viscosity of the system increases during spinning, and stable spinning tends to be impossible.

Having described both the core and sheath components, the composite ratio of the core and sheath will now be described. The composite ratio of the sheath / core component is in the range of 0.01 to 0.30, preferably in the range of 0.01 to 0.20, in terms of the yarn cross-sectional area ratio. When the ratio of the sheath component exceeds 30%, the elastic recovery of the obtained yarn, the recovery from high temperature, the heat resistance is insufficient, and the yarn is liable to be brittle. Conversely, if this ratio is less than 1%, the sheath component is broken or the core component is easily exposed on the yarn surface, which is unfavorable because it adversely affects spinnability and light resistance.

As the composite form of the core and sheath, it is preferable that the center of gravity of both components of the core and sheath is mainly the same from the viewpoint of spinning stability and the uniformity of the obtained yarn. The cross-sectional shape of the composite yarn may be circular, irregular, such as triangular or flat.

What is important here is that if the sheath of the composite yarn completely covers the core and the center of gravity of the sheath and the core is mainly the same, the spinning can be performed even if the viscosity balance of both the core and the sheath is slightly different. Sex is very good. This is a feature not found in a yarn having an eccentric cross section.

The method of constructing a composite yarn having a crosslinked polyurethane as a core among the yarns of the present invention will be described.

A polyisocyanate is added to a portion where a thermoplastic polyurethane is melt-extruded, a portion for mixing and mixing, a portion for extruding a sheath component, and a melt composite spinning apparatus equipped with a spinning head having a known core-sheath type composite spinneret. It is preferred to carry out.

As a device used for adding the polyisocyanate during spinning, a known device can be used. It is also possible to use a kneading device having a rotating section in the portion where the polyisocyanate is added to and mixed with the polyurethane in a molten state, but it is more preferable to use a mixing device having a stationary kneading element. A well-known mixing device having a stationary kneading element can be used. The shape and the number of the static kneading elements vary depending on the conditions used, but are selected so that the thermoplastic polyurethane elastomer and the polyisocyanate are sufficiently mixed before entering the composite spinneret. It is important that 20 to 90 elements are provided.

The thus mixed polymer is used as a core component, the polyester copolymer of the sheath component is melted by another extruder, and both are guided to a core-sheath composite die and spun to obtain the composite yarn of the present invention. can get.

The composite yarn immediately after being wound after spinning has poor physical properties such as strength and heat resistance, but when left at room temperature for about 2 hours to 7 days, the physical properties are greatly improved. . The reason why the yarn quality and thermal performance of the composite yarn spun in this way changes with time is that the reaction of the polyisocyanate mixed with the thermoplastic polyurethane used as the spinning raw material is not completed during spinning, It is presumed that it proceeds even after spinning.

Further, the second yarn of the present invention can be obtained by subjecting the above-mentioned composite yarn after a lapse of time to a stretching ratio of 1.2 to 5 times under the condition with or without heat. In this case, the draw ratio and the heating temperature are determined depending on the desired amount of hot water shrinkage, and usually, the higher these conditions, the higher the shrinkage of the yarn.

[0035]

As described above, the composite elastic yarn of the present invention
Since the sheath component is polyester and the core component is polyurethane,-An ordinary emulsion for polyester fibers can be used as an oil agent during spinning, and there is almost no sticking.・ Excellent winding property during spinning, and can be rolled up.・ When spinning and winding, high speed such as 1000 m / min.
Moreover, it is also possible to wind it up on a small-diameter bobbin.・ Excellent productivity due to the melt spinning method. -Can be mixed with polyester fiber (for example, 1
It can be dyed at 30 ° C. and has excellent dyeability).・ Excellent mold resistance.・ Excellent operability in post-processes such as weaving and weaving. -In the case of a crosslinked polyurethane in which a polyisocyanate is disposed on the core side, it has excellent recoverability and heat resistance. Etc.

Surprisingly, since the yarn itself has elasticity, it can be used for various uses such as swimwear, socks, innerwear and pantyhose. At this time, the composite elastic yarn of the present invention may be used alone, or this yarn may be used as a yarn mixed with another yarn (for example, a yarn covered with nylon or the like).

[0037]

EXAMPLES Hereinafter, the present invention will be described specifically with reference to Examples, but the present invention is not limited thereto.

Example A Thermoplastic polyurethane Polyhexamethylene adipate having a molecular weight of 1950
A polyurethane was synthesized by a conventional method using 6 mol, 50.5 mol of p, p'-diphenylmethane diisocyanate, and 34.9 mol of 1,4-butanediol as a chain extender. The relative viscosity of the obtained polymer in dimethylformamide at a concentration of 1 g / 100 ml measured at 25 ° C. was 2.11.

Polyisocyanate polycaprolactone diol 2 having a number average molecular weight of 1250
A viscous compound was obtained by reacting 3.9 mol, 4.2 mol of polycaprolactone triol having a number average molecular weight of 1250, and 71.9 mol of p, p'-diphenylmethane diisocyanate. NCO weight% of this compound is 6.6 weight%
Met.

Copolyester bis-hydroxyethyl terephthalate (hereinafter referred to as BHE)
T) and bis-hydroxyethyl isophthalate (hereinafter referred to as BHEI) are appropriately mixed, and autoclaved (internal temperature 270).
C.) under vacuum stirring to prepare five types of copolymerized polyesters having a copolymerization ratio of isophthalic acid of 10, 20, 30, 50, and 60 mol%, and formed into chips.

The above thermoplastic polyurethane was melted by an extruder, and the above polyisocyanate was added in the course of the melt flow, and kneaded sufficiently with a 35 element static mixer (manufactured by Kenix). On the other hand, the above copolyester was melted by another extruder, and these melts were separately weighed and led to an 8-hole concentric composite die (nozzle orifice diameter 0.5 mm). The composite ratio of the sheath was varied in the range of 0.008 to 0.10. The spinning speed was 600 m / min, and a monofilament having a fineness of 40 d was obtained. The amount of polyisocyanate added at this time was 17
%. A 15% emulsion for polyester was used as a spinning oil.

Next, the above-mentioned thermoplastic polyurethane was spun similarly in place of the copolymerized polyester as the sheath component. The oil used in this case was a mixture of dimethyl silicon and 5% and 0.2% amino-modified silicon (Comparative Examples 1 and 2, respectively). No sticking was observed for the yarn of Comparative Example 1.

Table 1 shows the results of the operability of the polyester in the drying step and the composite spinning step. Table 2 shows the physical properties of the composite yarn.

[0044]

[Table 1]

When the copolymerization ratio of isophthalic acid was 10 mol%, the spinning temperature on the polyurethane side had to be increased, and the heat stability became poor, so that composite spinning was impossible. On the other hand, when the ratio was 60 mol%, the mixture became stiff when dried, and chips were not bitten during spinning and spinning was impossible.

[0046]

[Table 2]

In this table, the unwinding coefficient means that when the composite yarn wound on the bobbin is unwound at a speed of 50 m / min, the unwinding of the yarn becomes impossible due to sticking of the bobbin surface. And the surface speed ratio between the bobbin surface speed and the take-up roller.

The long winding time is an outer diameter of a paper tube of 83 mm.
Represents the time required for winding up without boring and breaking on a bobbin with a spinning speed of 600 m / min.

The heat resistance refers to the temperature at which the yarn is stretched by 50% when the yarn is subjected to a load of 12.5 mg / d and measured at a temperature rising rate of 70 ° C./min.

The high-pressure dyeability means that the composite yarns shown in Table 2 are knitted in a single knitting machine at a concentration of 2% owf of a blue dye at 130 ° C.
Stain under conditions of × 60 minutes, and then reduce and wash at 70 ° C. × 2
After 0 minutes, the color difference between each tubular knitted fabric and the standard polyester fabric dyed in the same bath was measured, and the color difference (ΔE) was 1.5 or less, and ○ was 12 or more.

From Table 2, it can be seen that the polyurethane-polyurethane type composite yarn (Comparative Example 1) has a good unwinding property, but has a drawback in winding property. It can be seen that although は is good, there is a problem in the unwinding property, and the high-pressure dyeing property is poor in these comparative examples.

On the other hand, in the examples of the present invention, it is understood that the unwinding property and the winding property are very good, and the high pressure dyeing property is also excellent. From Examples 1 and 2, the heat resistance greatly changes depending on the presence or absence of cross-linking in the core component, and from Examples 3, 4, and 5, when the composite ratio decreases, that is, when the ratio of the sheath component decreases, the polyurethane-polyurethane type It can also be seen that the physical properties of the composite yarn approached.

Example B The yarns of Example 2 and Comparative Example 1 were immersed in soil at 26 ° C.
The sample was buried under the condition for one month, and thereafter, each sample was washed with water and dried with air, and the strength retention was measured. The results are shown in Table 3. Table 3 shows that the strength retention of the yarn of the present invention is extremely good.

[0054]

[Table 3]

Example C Polyisocyanate A viscous compound was prepared by reacting 30.2 mol% of a polybutylene adipate polyol having a molecular weight of 953 and a functionality of 2.0 with 69.8 mol% of p, p'-diphenylmethane diisocyanate. I got The NCO weight percent of this compound is 7.
It was 2% by weight.

Copolyester A polyester was synthesized by a conventional method from 85 mol% of terephthalic acid, 15 mol% of dimethyl isophthalate, 85 mol% of ethylene glycol, and 15 mol% of diethylene glycol. Its glass transition temperature was 64 ° C. The thermoplastic polyurethane of Example A was melted by an extruder, and the above-mentioned polyisocyanate was added in the middle of the flow of the melt, and kneaded sufficiently with a 35-element static mixer (manufactured by Kenix). On the other hand, the above-mentioned copolymerized polyester was melted by another extruder, and these were separately weighed and concentrically formed into an 8-hole composite die (with a nozzle diameter of 0.1 mm).
5 mm). The spinning speed was 600 m / min, and a monofilament having a fineness of 40 d was obtained. 15 as spinning oil
% Water emulsion was used. The amount of polyisocyanate added was fixed at 18%, but the composite ratio of the sheath component was changed as shown in Table 1. Further, the yarn in the case where the polyisocyanate was not added was spun in the same manner.

Next, spinning was performed in the same manner using the above-mentioned thermoplastic polyurethane instead of the copolymerized polyester as the sheath component. The oil agent used here was a mixture of dimethyl silicon and 5% and 0.2% amino-modified silicon (Comparative Examples 3 and 4, respectively).

Table 4 shows the results.

[0059]

[Table 4]

In the table, the unwinding coefficient means that when the composite yarn wound on the bobbin is unwound at a speed of 50 m / min, the unwinding of the yarn becomes impossible due to sticking of the bobbin surface. And the surface speed ratio between the bobbin surface speed and the take-up roller.

The heat resistance refers to the temperature at which the yarn is stretched by 50% when a load of 12.5 mg / d is applied to the yarn and measured at a heating rate of 70 ° C./min.

The possible winding time is the time during which the yarn can be wound on a bobbin having an outer diameter of 83 mm at a spinning speed of 600 m / min without traversing and collapsing.

From Table 4, it can be seen that the polyurethane-polyurethane type composite yarn (Comparative Example 1) has a good unwinding property but has a drawback in winding property. It can be seen that although is better, there is a problem in the unwinding property. On the other hand, in the examples of the present invention, it is understood that the unwinding property and the winding property are excellent, and that when the core component is a crosslinked urethane, the heat resistance, strength, and the like are greatly improved. In addition, it can be seen that when the composite ratio of the sheath component is reduced, the heat resistance and the thread properties are improved.

When the yarn was spun with the sheath ratio of 50% in Example 7, the yarn obtained was very brittle and had poor drawability. Also, the knitting property was poor.

Example D The yarns of Example 2 and Comparative Example 1 were drawn at 90 ° C. at a double magnification. Then, apply an initial load of 1.0 mg / d and apply a temperature of 100
Immersed in hot water of 30 ° C. for 30 minutes, air-dried, and shrinkage L (m
m) was measured, and the heat yield was calculated by the following equation.

On the other hand, the shrinkage amount L1 (mm) was measured as the natural shrinkage amount before being immersed in hot water, and calculated by the following equation. Here, L0 is the original length.

[0067]

[Table 5]

From Table 5, it can be seen that the yarn of the present invention has a small amount of natural shrinkage and a very large amount of shrinkage due to hot water.

Next, the draw ratio was changed at 120 ° C. using the yarns of Examples 7 and 8. The results of measuring the heat yield are shown in Table 6. The natural shrinkage of these yarns is 0.5
% Or less.

[0070]

[Table 6]

From Table 6, it can be seen that when the sheath component amount increases and when the stretching ratio increases, the heat yield increases.

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-62-21820 (JP, A) JP-A-4-214413 (JP, A) WO 91/5088 (WO, A1) (58) Fields surveyed (Int.Cl. ⁶ , DB name) D01F 8/14 D01F 8/16

Claims (4)

(57) [Claims] 1. A composite yarn comprising ethylene terephthalate as a main component and a sheath made of a copolymerized polyester in which 12 to 50 mol% of an acid component is isophthalic acid, and a polyurethane elastomer as a core. A polyester / polyurethane composite elastic yarn, wherein the composite ratio in the yarn cross section is in the range of 0.01 to 0.30. 2. A dicarboxylic acid component comprising 60 to 88 mol% of terephthalic acid and 12 to 40 mol% of isophthalic acid.
75 to 90 mol% of ethylene glycol and at least one selected from the group consisting of diethylene glycol, triethylene glycol, neopentyl glycol and butanediol
2. The composite elastic yarn according to claim 1, wherein a copolyester obtained from a diol component containing 10 to 25 mol% of a seed is used as a sheath. 3. The composite elastic yarn according to claim 1, wherein the polyurethane is a crosslinked polyurethane mainly composed of allophanate bonds. 4. The composite elastic yarn according to claim 1, wherein the center of gravity of each core-sheath is the same in the cross-sectional shape of the composite yarn.