JP3162926B2 - Method for producing urethane elastic fiber - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a polyurethane elastic fiber by a melt spinning method.

More specifically, when the polyurethane elastic fiber is melt-spun, sticking between the yarns on a spinning bobbin is prevented, and the unwinding property of the yarn in a subsequent processing step is improved.
The present invention relates to a method for maintaining a moderate slippage of a yarn, preventing a yarn bobbin or the like from falling and breaking, and stabilizing operability in the spinning and subsequent processing steps.

[0003]

2. Description of the Related Art Melt spinning, dry spinning, wet spinning, and the like have been conventionally used as methods for obtaining polyurethane elastic fibers. Recently, in order to improve the stretchability and heat resistance of urethane yarns. A method of mixing and spinning a prepolymer having an active isocyanate group is often used. In any of these methods, when the fibers are wound during spinning, the fibers adhere to each other, and when the yarn is unwound from the bobbin in the subsequent process and pulled out, it is difficult to pull out the yarn due to the resistance of the adhesive. In this case, thread breakage occurs, and a state where smooth operation cannot be performed occurs. In particular, in the prepolymer mixed spinning method in which a large amount of active isocyanate groups are present, this agglomeration is remarkable, and if an ordinary oil agent is applied, no thread can be pulled out in the subsequent step.

[0004] As a method for preventing the sticking of polyurethane, a method of applying solid fine particles of talc, silica, colloidal alumina or the like to the fiber as an aqueous or oily slurry, a method of dispersing a metal salt powder of a higher fatty acid in water or mineral oil. Method (JP-B-41-286, JP-B-40-55)
No. 7) Methods using room temperature solid waxes such as higher aliphatic carboxylic acids, higher aliphatic alcohols, paraffins and polyethylene oxide (JP-B-43-272, JP-B-43-9955, JP-B-44-197). Many methods have been proposed, including polyalkylene oxide-modified silicon (Japanese Patent Publication No. 44-8907) and cyclic amylsiloxane (Japanese Patent Publication No. 39-24858) as liquid substances at room temperature.

[0005] However, these anti-adhesion agents mainly based on the release effect have no effect on the post-adhesion chemical reaction due to the isocyanate group described below, and cannot be said to be a sufficiently satisfactory method.

The adhesion between the yarns in the spinning of the polyurethane elastic yarn is not due to the rubbery tackiness of the polyurethane, and the active isocyanate group on the yarn surface on the yarn surface is generally referred to as self-adhesion. Agglutination (the formation of allohanate bonds and other chemical bonds) occurs due to the reaction. In this self-adhesion action, as the number of isocyanate groups present on the polymer surface increases, the chemical reaction on the yarn surface progresses, and a firm adhesion is formed. Immediately after spinning, even if the bobbin is capable of unwinding the yarn, the self-adhesion between the yarns progresses after several days, and the unwinding of the yarn becomes impossible.In extreme cases, each layer of the yarn wound on the bobbin has a plate shape. And the thread cannot be pulled out at all.

[0007] In particular, this phenomenon is severe when a polyurethane elastic yarn is produced by a melt spinning method. In a method of mixing and spinning a prepolymer having an active isocyanate group at a terminal,
This tendency is remarkable, and a sufficient anti-adhesion property cannot be obtained with only the above-mentioned releasable anti-adhesion agent.

In order to prevent sticking due to the chemical reaction of the isocyanate group, it is necessary to deactivate the isocyanate group, and a method using a deactivator having an active hydrogen group has been proposed. As a method therefor, a method of applying a mineral oil in which a monoamine is already dissolved at the time of spinning (Japanese Patent Publication No. 46-16 / 1976)
No. 312), an oil agent containing a diamine (Japanese Patent Publication No. Sho 58)
-132170) has been proposed.

This method is an effective method to deactivate the isocyanate group. However, the viscosity of the urethane polymer itself is low during melt spinning, or a low-viscosity prepolymer is mixed during spinning. When the viscosity of the polymer is lowered and the filament immediately after spinning is wound up while still soft, sticking due to the adhesion of the polyurethane appears strongly, and a sufficient anti-sticking property cannot be obtained with the deactivator of the isocyanate group alone.

[0010] As an anti-sticking agent having both properties of releasing property immediately after spinning and the effect of deactivating the active isocyanate group,
Oils already used in combination with amino-modified silicone (JP-B-44-
No. 8907).

In this method, even when the spun yarn is soft and a large amount of isocyanate groups are present on the yarn surface during melt spinning, the releasing effect of the dimethyl silicon chain and the loss of the isocyanate groups due to the active hydrogen of the amino groups are obtained. Shows excellent anti-sticking properties by active action.

However, in the amino-modified silicone having sufficient anti-sticking properties, the obtained yarn has a very low frictional force between fibers, so that the winding bobbin at the time of spinning and the winding bobbin from the spinning bobbin to another bobbin can be used. In the meantime, the rewinding yarn will fall and collapse. For this reason, the amino-modified silicon which does not have a problem in the winding property has to be used while sacrificing the anti- sticking property to some extent.

As described above, various substances have been proposed as anti-sticking agents. Although an almost satisfactory composition has been proposed from the standpoint of anti-sticking property alone, no oil has been found which has no problem in practical use, including operability in spinning and post-processing steps.

[0014]

DISCLOSURE OF THE INVENTION The present invention relates to a method for spinning polyurethane elastic yarn by a melt spinning method or the like, which suppresses the sticking of the yarn due to the active isocyanate group present on the surface of the yarn and the rise of the sticking with time, and the spinning and spinning. It is an object of the present invention to provide a method for producing a polyurethane, which prevents bobbin tearing and collapse in a subsequent step and obtains excellent operability in a subsequent step from spinning.

[0015]

Means for Solving the Problems In order to solve the above-mentioned problems, the present inventors have made intensive studies on the composition of an oil agent to be applied at the time of spinning.

Embedded image After giving an aqueous emulsion containing a polyetheramine represented by, and subsequently applying a non-aqueous oil agent,
The present invention has been achieved by winding.

The polyetheramine used in the present invention is characterized in that the active hydrogen of the amino group present in the molecule reacts with the active isocyanate group of the polyurethane exposed on the surface of the yarn, thereby eliminating the isocyanate. Agglutination due to the chemical reaction of the nato group can be suppressed.

The present invention is effective for spinning urethane alone, but is particularly effective when a large amount of isocyanate groups are present on the yarn surface, such as when a prepolymer having an active isocyanate group is mixed during spinning and spun. The effect of the present invention is well exhibited.

The polyurethane used for the conjugate fiber of the present invention can be any composition as long as it is a thermoplastic polyurethane that can be subjected to melt spinning. Further, in order to improve the elasticity and heat resistance of polyurethane, materials which have undergone some modification during spinning, such as those obtained by mixing and spinning a diisocyanate compound during spinning, can also be used.

Polyol components constituting the thermoplastic polyurethane include polyethylene glycol, polypropylene glycol, polytetramethylene glycol, polyethers such as copolymers of ethylene oxide and propylene oxide, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, and the like. Esters of a copolymer of ethylene oxide and propylene oxide with a dibasic acid such as adipic acid, polyε-caprolactone, polyhexamethylene carbonate, silicone polyol, and the like.

As the diisocyanate component, 4.
4'-diphenylmethane diisocyanate, 4.4'-
Examples include dicyclohexylmethane diisocyanate, isophorone diisocyanate, and hexamethylene diisocyanate.

The aqueous oil agent of the present invention to be applied when spinning polyurethane elastic fibers may be an aqueous solution in which only polyetheramine is dissolved, or in order to increase the permeability of the aqueous solution in consideration of uniform adhesion to the yarn. A nonionic activator having a penetrating effect may be used in combination, or a commonly used oil agent mainly composed of mineral oil, fatty acid ester and dimethylsiloxane may be mixed with polyetheramine in order to increase the smoothness of the yarn.

In order to exert the releasing effect of the polyetheramine, a high molecular weight polyetheramine is more effective, but one having a molecular weight of 200 to 10,000 is used. When the molecular weight is less than 2,000, the increase of the sticking over time can be suppressed,
If the releasing effect immediately after spinning is slightly weak, and if it exceeds 10,000, the viscosity of the aqueous solution applied at the time of spinning becomes too high, the uniform adhesion to the yarn surface is deteriorated, and sticking spinning spots occur, which is not preferable.

Any weight ratio of polyethylene glycol to polypropylene glycol of the polyetheramine can be used. However, if the polypropylene glycol portion is too large, the water solubility of the polyetheramine alone becomes poor, and the yarn is spun with an aqueous solution during spinning. Difficult to use when granting. In terms of water solubility, polyethylene glycol is 40
% Or more of polyetheramine is easy to use, but other compositions can also be used if used in combination with a surfactant having excellent dispersibility as an emulsion.

The application amount of the yarn of the polyether amines, by setting appropriately the sticking conditions of the spun yarn is applied amount of polyether A <br/> amine is too high, since the smoothness of the yarn is deteriorated , 0.5% or less, preferably 0.3% or less.

The amount of the aqueous solution of polyetheramine applied to the yarn may be any level as long as water droplets do not ooze onto the surface of the winding bobbin, but is usually limited to 20% by weight. Depending on the amount of polyetheramine applied . The concentration of the aqueous solution is appropriately determined so as to be 5% or less.

The application of polyetheramine alone results in extremely poor smoothness of the yarn. Therefore, in addition to the application of polyetheramine, the application of a non-aqueous blended oil is essential.

The non-aqueous blended oil agent subsequently applied to the water-based emulsion may be of any composition, but may be used for uniform adhesion to the yarn and for preventing the yarn from winding around the roller due to the viscous resistance of the oil agent during spinning. Therefore, the viscosity at 30 ° C is 5
-50 CST or less is preferred.

When a non-aqueous oil agent such as a mineral oil, a fatty acid ester, or dimethylsiloxane is used as a lubricant, if the viscosity is less than 5 CST, the oil agent has high volatility and volatilizes and disappears from the yarn surface after spinning. Is unfavorably caused by a decrease in smoothness.

As a method for applying the oil agent to the yarn, known methods such as a spraying method, a roller surface contact method, and a lubrication guide method can be used, but the lubrication guide method is the best considering uniform adhesion to the yarn.

[0030]

The present invention will be described in detail with reference to the following examples.
Examples of methods for evaluating the effects of the present invention include unwinding tension (immediately after spinning and after elapse of time) as a substitute property of anti-sticking property, inter-fiber friction force as a substitute property of collapse of a spinning bobbin and a rewind bobbin, and spinning bobbin winding. Collapse situation was used.

Unwinding tension 1 m / mi from spinning bobbin
n means the tension required to separate the yarn from the bobbin surface when the yarn is pulled out at a take-up speed of n (see Fig. 1). Assume tension. Measurements were taken immediately after spinning and after 7 days.

The inter-fiber friction force The spun yarns are combined so that the total denier becomes 400 denier, and the secondary tension is measured by the crossing method shown in FIG. (1) Temporary tension (initial tension) 1 gram (2) Number of yarn crossings 1 twist (360 degree rotation) (3) Yarn speed 2 cm / min (4) Measurement temperature and humidity 25 ° C, 65% RH

Spinning bobbin winding collapse A 40-denier yarn having a winding width of 80 mm (200-diameter winding bobbin) with a contact pressure of 500 g between the spinning friction roller and the winding bobbin and a winding angle of 5 degrees was wound at 500 m / min for 10 hours. The winding shape at that time is observed with the naked eye, and the one with no twill drop, collapse, or spreading of the bottom thread is regarded as good.

The polyetheramine can be produced by a method described in Experimental Chemistry Lecture Vol. 28, p. 463 using methoxy polyol synthesized using methanol as a reaction starting material.

Example 1 Polytetramethylene glycol having a molecular weight of 1500 as a polyether and 4.4 'as a diisocyanate compound
When a thermoplastic polyurethane elastomer having a Shore hardness of 90 comprising diphenylmethane diisocyanate and 1.4-butanediol as a chain extender is melted at 210 ° C. and extruded with a screw extruder, before entering a spinneret, Poly (1.4-oxybutylene) having a molecular weight of 1500
After mixing 15% by weight of the diisocyanate with respect to the polyurethane polymer, the mixture was discharged from a 0.5 mm nozzle.
It was wound on a bobbin at 00 m / min to obtain a monofilament of 40 denier.

The weight ratio of polyethylene glycol is 5 before being extruded from the spinneret and wound on a bobbin.
After adding 20% by weight of a 2% by weight aqueous solution in which 0% polyetheramine having a molecular weight of 3500 is dissolved to the yarn, 2% is applied to the non-aqueous oils of the oil A shown in Table 1 and the oil B shown in Table 2. And wound up.

[0037]

[Table 1]

[0038]

[Table 2]

As a comparative example of the present invention, as an example in which an aqueous solution of polyetheramine is not applied after spinning, oil agent A
In the case where only the non-aqueous oil agent of B and B and the oil agent C of Table 3 were used, and in the case where only polyetheramine was applied, the yarn was similarly collected and evaluated.

[0040]

[Table 3]

In each step of collecting these yarns, the evaluation results of the unwinding tension of the spinning bobbin, the frictional force between the fibers, and the winding shape of the spinning bobbin are shown in Table 4 in order to judge the superiority of the oil agent.
It is shown in Table 5.

[0042]

[Table 4]

In the comparative example to which only polyetheramine was applied, since the smoothness of the yarn was poor, the frictional resistance with the yarn guides in the rewinding process was large, and the yarn was frequently broken. Since the yarn of the present invention has excellent anti-sticking properties and moderate smoothness, the operation in the subsequent step was extremely smooth.

[0044]

[Table 5]

Among the comparative oils not using polyetheramine, oils A and B having no active hydrogen to deactivate the isocyanate group show a large increase in sticking over time and a poor unwinding property of the yarn upon rewinding. There were many cuts and the operability after the spinning process was poor. Although the oil agent C exhibited excellent anti-sticking properties, the frictional force between the fibers was too low, so that the bobbin collapsed during the winding of the spinning yarn, and the winding could not be performed for a predetermined time.

As described above, the use of the polyetheramine of the present invention did not cause collapse of the spinning bobbin as compared with the case where the present compound was not used, and the excellent anti-sticking property of the main purpose was obtained.

[0047]

According to the method for producing a urethane elastic fiber of the present invention, since the spinning bobbin has less sticking and the winding shape of the spinning bobbin is excellent, the unwinding property and the winding shape in the subsequent process are poor. A high-quality urethane elastic fiber with few yarn breaks and excellent operability can be obtained.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a method of measuring an unwinding tension.

FIG. 2 is a diagram illustrating a method of measuring a friction force between fibers.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) D01F 11/00-11/16 D01F 6/70 D01F 9/94 D06M 13/00-15/72

Claims (1)

(57) [Claims] In the case of melt-spinning a urethane polymer, a general formula is obtained after a thread coming out of a die is solidified. After giving an aqueous emulsion containing a polyetheramine represented by, and subsequently applying a non-aqueous oil agent,
A method for producing urethane elastic fiber, characterized by winding.