JP2016520164A - Polyurethane urea elastic yarn with excellent uniformity and thermosetting - Google Patents

Abstract

The present invention relates to a polyurethaneurea elastic yarn. 1) A prepolymer is produced using a mixture containing 2,4'-diphenylmethane diisocyanate in an amount of 2 to 25 mol% relative to the total weight of diisocyanate. 3) Adding a chain extender and 3) obtaining a polyurethane urea polymer having a solid content of 40 mol% or more of the final polymer, and then agitating and spinning the obtained polyurethane urea spinning solution to spin it. The present invention relates to an elastic yarn excellent in uniformity and thermosetting. [Selection figure] None

Description

  The present invention relates to a polyurethane urea elastic yarn excellent in uniformity and thermosetting. More specifically, in the production of the polyurethane prepolymer, the final polyurethane urea is used by mixing 2 to 25 mol% of 2,4′-diphenylmethane diisocyanate with one or more diisocyanates containing 4,4′-diphenylmethane diisocyanate in the diisocyanate. The present invention relates to a polyurethane urea elastic yarn excellent in uniformity and thermosetting, characterized in that a solid content of a polymer is 40% by weight or more.

  Polyurethane urea generally has a primary polymerization reaction product in which a polyol and an excess amount of a diisocyanate compound are reacted to obtain a prepolymer having isocyanate groups at both ends of the polyol, and the prepolymer is dissolved in an appropriate solvent. Then, after adding a diamine or diol chain extender to the solution and reacting with a chain terminator such as monoalcohol or monoamine, a polyurethane urea fiber spinning solution is prepared, and then dry and wet Polyurethane urea elastic yarn is obtained by spinning.

  Such polyurethane urea elastic yarns are used in various applications due to their inherent properties with excellent elasticity and elastic recovery, and new properties added to conventional fibers as the range of applications expands. Has been sought after.

  In general, polyurethane urea elastic yarn causes thermal embrittlement of the counterpart yarn due to high heat treatment for setting in post-processing performed after mixed knitting with heat sensitive counterpart yarn (nylon, silk, cotton, etc.) Problems such as yellowing of the original fabric and lowering of the touch have occurred. In order to solve these problems, the demand for polyurethane urea elastic yarns that can be heat-set even at low temperatures has increased, and in the meantime, elastic yarn manufacturers have made efforts to improve the thermosetting properties of polyurethane urea elastic yarns. Has been made continuously.

  For example, in Patent Document 1 (US Pat. No. 5,948,875), a method for improving the thermosetting property of a polyurethane urea elastic yarn by using 50 mol% or more of 2-methyl-1,5-pentanediamine as a chain extender US Pat. No. 6,472,494 discloses a method for improving the thermosetting property of polyurethane urea elastic yarn by applying the mixed 2,4-diphenyl diisocyanate content to 23 to 55 mol%. In Patent Document 2 (Domestic In-house Patent No. 0,942,359), 2 to 25 mol% of 2,4′-diphenylmethane diisocyanate is mixed and 1,2-diaminopropane is used as an auxiliary chain extender. A method of using and improving thermosetting is disclosed. However, the technology disclosed by the above patents has a disadvantage in terms of workability due to a decrease in heat resistance, an insufficient modulus and elastic recovery rate, a reduction in yarn tension during spinning, an increase in yarn flow, There is an inconvenience that the uniformity of the raw yarn is insufficient and the quality of the raw fabric becomes poor when the cross / knitted fabric is applied.

US Pat. No. 5,948,875 Korean Patent No. 0,942,359

  As described above, until now, the technology for producing polyurethane urea elastic yarn having excellent uniformity and thermosetting properties has not been completely established.

According to the embodiment of the present invention, it is a polyurethane urea elastic yarn having a cross-sectional irregularity of 1.20 or less and an HSE of 50% or more based on the following measurement method.
1) A method for measuring the cross-section deformity, in which a polyurethane urea elastic yarn is cut perpendicularly to the longitudinal direction, the lengths of W and H of the cross-section are measured with a microscope, and the cross-section deformity defined by the W / H ratio Calculate the measurement method. Here, W is the length of the longest straight line that crosses the cross section of the raw yarn, and H is the length of the shortest straight line that perpendicularly intersects the longest straight line (W) that crosses the cross section of the raw yarn. It is.

  2) HSE measurement method, in which the initial yarn L0 is 100% stretched L1 while exposed to the atmosphere, then dry heat-treated at 170 ° C. for 1 minute, cooled at room temperature, and then the length of the yarn L2 is measured, and the dry-heat treated raw yarn is wet-heated at 100 ° C. for 30 minutes in a relaxed state, dried at room temperature, and the length L3 of the raw yarn is measured. Measuring method to measure.

HSE (%) = {(L3-L0) / (L1-L0)} × 100 (Formula 1)
According to another embodiment of the present invention, in a polyurethane urea elastic yarn comprising a polyol and a diisocyanate polymer,
1) A prepolymer is produced using a mixture containing 2,4'-diphenylmethane diisocyanate in an amount of 2 to 25 mol% relative to the total weight of diisocyanate,
2) After adding a chain extender to the prepolymer to obtain a polyurethaneurea polymer,
3) To provide a polyurethane urea elastic yarn excellent in uniformity and thermosetting, characterized by producing a polyurethane urea spinning stock solution having a solid content of the final polyurethane urea polymer of 40% by weight or more and spinning it.

  According to another embodiment of the present invention, the content of the first diisocyanate is 75 to 98 mol% and the content of the second diisocyanate is 2 to 25 mol%, wherein the second diisocyanate is 2,4 It is characterized by using '-diphenylmethane diisocyanate. 2,4'-diphenylmethane diisocyanate has a steric structure compared to the existing 4,4'-diphenylmethane diisocyanate, and due to steric hindrance, the hard segment intermolecular, hydrogen bond strength and intramolecular hydrogen bond strength are weakened. As a result, the same effect as that obtained by increasing the soft segment content can be obtained.

  According to another preferred embodiment of the present invention, the final polyurethaneurea polymer has a solid content of 40% by weight or more. If the solid content is 40% by weight or more, the difference between the drying speed of the raw yarn surface and the solvent diffusion rate between the inside and the surface of the raw yarn is reduced during spinning, so that the cross section of the raw yarn becomes more circular. As a result, the value of the non-round type cross section is close to 1.0, the cross-sectional variant of the raw yarn approaches 1.0, and the cross-sectional variant of the raw yarn approaches 1.0. The uniformity of the original yarn is improved.

  The polyurethane urea elastic yarn according to the present invention has a cross-sectional profile of the raw yarn of 1.20 or less, a aster% of less than 1.0, a heat set efficiency (HSE) of 50% after treatment at a dry heat temperature of 170 ° C. It is the above.

  By producing a polyurethane urea elastic yarn having excellent uniformity and thermosetting, the quality of the original fabric is excellent because there is no decrease in uniformity, and heat setting at a low temperature is possible. By preventing thermal embrittlement of the yarn, there is no yellowing of the cross / knitted fabric, and the touch is excellent in touch.

It is a figure which shows typically the length H of the longest straight line in the cross section of a raw yarn, and the length (W) of the shortest straight line. It is a figure which shows typically the area ratio for calculating | requiring U%.

  Hereinafter, the polyurethane urea elastic yarn of the embodiment of the present invention will be described in more detail. However, the embodiments of the present invention can be modified in various forms, and the scope of the present invention is not limited to the embodiments described below. Note that, throughout this specification, unless it is stated to the contrary, “including” a certain component does not exclude other components, but can further include other components. means.

  The elastic yarn according to the embodiment of the present invention is obtained by polymerizing an excess amount of diisocyanate with a polyol to obtain a prepolymer and dissolving it in an organic solvent, and then adding a chain extender and a chain terminator to the solution. A secondary polymerization is performed to produce a spinning dope. At this time, the chain extender and the chain terminator can be added all at once, or can be added in two or more stages.

  Specific examples of the diisocyanate used in the production of the polyurethaneurea elastic yarn in the present invention include 4,4'-diphenylmethane diisocyanate, 1,5'-naphthalene diisocyanate, 1,4'-phenylene diisocyanate, hexamethylene diisocyanate, 1,4 '-Cyclohexane diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, or isophorone diisocyanate. Among these diisocyanates, 2,4'-diphenylmethane diisocyanate is added to one or more diisocyanates including 4,4'-diphenylmethane diisocyanate. In this case, the proper content of 2,4'-diphenylmethane diisocyanate is 2 to 25 mol%.

Since 2,4'-diphenylmethane diisocyanate has a steric structure compared to the existing 4,4'-diphenylmethane diisocyanate, hydrogen bonding force between hard segment molecules and intramolecular An effect similar to that obtained by weakening the hydrogen bonding force and increasing the soft segment content has an effect of improving the thermosetting property of the raw yarn.
If the content of 2,4'-diphenylmethane diisocyanate is less than 2 mol%, the effect of improving the thermosetting property is insufficient, and if it exceeds 25 mol%, the yarn modulus will be inconveniently reduced. In the invention, the content of the 2,4′-diphenylmethane diisocyanate is preferably within the above range.

  The polymer diol used in the present invention includes polytetramethylene ether glycol, polytrimethylene ether glycol, polypropylene glycol, polycarbonate diol, a mixture of alkylene oxide and lactone monomer, and a copolymer of poly (tetramethylene ether) glycol, 3 Examples thereof include, but are not necessarily limited to, one or a mixture of two or more thereof from a copolymer of -methyl-tetrahydrofuran and tetrahydrofuran.

  In the present invention, the isocyanate weight ratio of the prepolymer is preferably 1.7 to 4.1% in order to exhibit appropriate physical properties as a polyurethane urea elastic yarn. If the isocyanate weight ratio of the prepolymer is less than 1.7% or exceeds 4.1%, the physical properties of the elastic yarn are seriously deteriorated.

  Examples of chain extenders include diamines such as ethylenediamine, 1,2-diaminopropane, 1,3-diaminopropane, 1,4-diaminobutane, 2,3-diaminobutane, and 1,5-diaminopentane. , 1,6-hexamethylenediamine, and 1,4-cyclohexanediamine, or a mixture of two or more thereof.

As the chain termination agent for polyurethane urea, an amine having one functional group, for example, diethylamine, monoethanolamine, dimethylamine or the like is used.
The final polyurethaneurea polymer has a solid content of 40% by weight or more. If the solid content is 40% by weight or more, the content of the solvent with respect to the solid content is low, so that there is a deviation between the solvent drying rate on the surface of the yarn during spinning and the solvent diffusion rate between the surfaces inside the yarn. By reducing it, more uniform drying is performed, and the cross section of the polyurethane urea elastic yarn has an effect of being close to a circle, and the profile irregularity approaches 1.0. When the cross section deformity value approaches 1.0, the elastic yarn has a uniform circular cross section, and the aster% is improved. When such an elastic yarn is used for knitting and dyeing a cross / knitted fabric This has the effect of improving the quality of the original fabric.

  Further, in the present invention, in order to prevent discoloration and deterioration of physical properties of polyurethane urea due to heat treatment process associated with ultraviolet rays, atmospheric smog and spantex processing, a sterically hindered phenol compound, benzofuran-one compound, semicarbazide is added to the spinning dope. A series compound, a benzotriazole type compound, a polymeric tertiary amine stabilizer and the like can be added in appropriate combination.

Furthermore, the polyurethane urea elastic yarn of the present invention may contain additives such as titanium dioxide and magnesium stearate in addition to the above components.
Hereinafter, the superiority of the present invention will be described in detail through specific examples and comparative examples. However, such examples are only for illustrating the present invention and limit the scope of the present invention. It should not be interpreted as a thing.

The NCO% measuring method of the polymer mentioned in Examples and Comparative Examples described later and the physical properties of the polyurethane urea elastic yarn were measured as follows.
<NCO% measurement method>
NCO% = [100 × 2 × NCO chemical formula amount × (capping ratio−1) / {diisocyanate molecular weight × capping ratio) + polyol molecular weight}
In the above formula, the capping ratio is diisocyanate molar ratio / polyol molar ratio.

<Strength and elongation of raw yarn>
Using an automatic strength / elongation measuring apparatus (MEL group, Texttechno), the sample length is 10 cm and the tensile speed is 100 cm / min. In this case, the strength and elongation values at break are measured, and the load (200% modulus) applied to the yarn when the yarn is stretched 200% is also measured.

<Cross section of raw yarn>
The raw yarn is cut perpendicularly to the longitudinal direction, the length of W and H is measured on the cross section with a microscope, and the ratio is calculated. The closer to 1.0, the closer the cross section is to a circle and the better the uniformity. Determined by

<Cross-section profile = W / H>
As shown in FIG. 1, W: the length of the longest straight line that crosses the cross section of the raw yarn H: the length of the shortest straight line that intersects perpendicularly with the longest straight line (W) that crosses the cross section of the raw yarn As the length, the profile irregularity = W / H is defined.

<U% of raw yarn>
Using a Uster% measuring device (KET-QT), the speed of the Feeding Roller is set to be different depending on the original yarn “de” (20d is 30 m / min) and measured. The sensor automatically reads the thickness of the raw yarn that has been unwound at a constant speed for 20 seconds, calculates the average value, and draws a 0% reference line. Based on this value, if the thickness of the raw yarn read by the sensor per unit time is larger, a point is taken in the 0% reference line contrast (+) area, and if the thickness is smaller, the 0% reference line contrast (-) is taken. A point is drawn in the area and a graph is drawn as shown in FIG. The degree of deviation from the 0% reference line is calculated as an area to indicate U%, and the smaller the value, the better the uniformity of the raw yarn.
U% = 0% Area deviating from reference line (black portion in FIG. 2) / area under 0% reference line (rectangle in horizontal line portion in FIG. 2) × 100

<Thermosetting of raw yarn>
After the initial raw yarn L0 is stretched 100% L1 while being exposed to the atmosphere, it is subjected to a dry heat treatment at 170 ° C. for 1 minute and then cooled at room temperature, and then the length L2 of the raw yarn is measured. In a relaxed state, the dry-heat treated yarn is wet-heat treated at 100 ° C. for 30 minutes, dried at room temperature, and the length L3 of the yarn is measured (where L0, L1, L2, and L3 are each step ( Processing) says the length of the raw yarn after). Thermosetting and HSE are each obtained by the following formula.

Dry heat curability (%) = {(L2-L0) / (L1-L0)} × 100
HSE (%) = {(L3-L0) / (L1-L0)} × 100
Example 1
Capping ratio CR 1.80,4,4′-diphenylmethane diisocyanate 95 mol% and 2,4′-diphenylmethane diisocyanate 5 mol% As the chain extender, ethylenediamine and 1,2-diaminopropane were used in a ratio of 80 mol% to 20 mol%, and diethylamine was used as the chain terminator. The ratio of the chain extender to the chain terminator is 10: 1, the amine used is adjusted to a total concentration of 7 mol%, and dimethylacetamide is used as a solvent, and the final polymer has a solid content of 45% by weight. A urea spinning solution was obtained.
The spinning stock solution obtained as described above was dry-spun at a speed of 900 m / min to produce 20-denier 1-filament polyurethane urea elastic yarn. The physical properties were evaluated and are shown in Table 1.

(Example 2)
A polyurethane urea elastic yarn is produced in the same manner as in Example 1 except that the content is 85 mol% of 4,4′-diphenylmethane diisocyanate and 15 mol% of 2,4′-diphenylmethane diisocyanate. The physical properties were evaluated and shown in Table 1.

Example 3
A polyurethaneurea elastic yarn is produced in the same manner as in Example 1 except that it is prepared with a content of 75 mol% of 4,4′-diphenylmethane diisocyanate and 25 mol% of 2,4′-diphenylmethane diisocyanate, The physical properties were evaluated and shown in Table 1.

Example 4
A polyurethaneurea elastic yarn was produced in the same manner as in Example 1 except that it was produced in a content of 70 mol% of 4,4′-diphenylmethane diisocyanate and 30 mol% of 2,4′-diphenylmethane diisocyanate. The physical properties were evaluated and shown in Table 1.

(Comparative Example 1)
A polyurethane urea elastic yarn was produced in the same manner as in Example 3 except that the solid content of the final polymer was 35% by weight, and its physical properties were evaluated and shown in Table 1.

  As shown in Table 1 above, when 2,4'-diphenyl diisocyanate is used in an amount of 25 mol% or more, it can be confirmed that the uniformity and thermosetting are excellent, but the 200% modulus is lowered. Even if 2 to 25 mol% of 2,4'-diphenylmethane diisocyanate in the final polymer is used, if the solid content of the final polymer is less than 40% by weight, the thermosetting property is excellent. It can be confirmed that U% is insufficient.

  As mentioned above, although the preferable example of this invention was described concretely to some extent, it cannot be overemphasized that various changes can be made about these. To that end, it should be understood that the invention can be practiced otherwise than as specifically described herein without departing from the scope and spirit of the invention. .

Claims (4)

Polyurethane urea elastic yarn having a cross-sectional irregularity of 1.20 or less and HSE of 50% or more based on the following measurement method.
1) A method for measuring the cross-section deformity, in which a polyurethane urea elastic yarn is cut perpendicularly to the longitudinal direction, the lengths of W and H of the cross-section are measured with a microscope, and the cross-section deformity defined by the W / H ratio Calculate the measurement method. Here, W is the length of the longest straight line that crosses the cross section of the raw yarn, and H is the length of the shortest straight line that perpendicularly intersects the longest straight line (W) that crosses the cross section of the raw yarn. It is.
2) HSE measurement method, in which the initial raw yarn L0 was stretched 100% while being exposed to the atmosphere, then the length L1 was measured, and then dry heat treated at 170 ° C. for 1 minute, and then cooled at room temperature Measure the length L2 of the yarn, and heat and heat-treat the raw yarn after post-drying heat treatment at 100 ° C. for 30 minutes in the relaxed state, and measure the length L3 of the yarn after drying at room temperature. A measurement method for measuring HSE according to (Equation 1).
HSE (%) = {(L3-L0) / (L1-L0)} × 100 (Formula 1)   The polyurethane urea elastic yarn according to claim 1, wherein 2,4'-diphenylmethane diisocyanate is contained in the polyurethane urea elastic yarn in an amount of 2 to 25 mol% based on the total amount of diisocyanate.   2. The polyurethane urea elastic yarn according to claim 1, wherein the polyurethane urea elastic yarn has a solid content of 40% by weight or more immediately before passing through a spinning nozzle. In the polyurethane urea elastic yarn, the NCO% at the time of primary polymerization defined by the following (formula 2) of the polyol and diisocyanate has a range of 1.7 to 4.1%. The polyurethane urea elastic yarn described in 1.
NCO% = [100 × 2 × NCO chemical formula amount × (capping ratio−1) / {diisocyanate molecular weight × capping ratio) + polyol molecular weight} (Formula 2)
In the above (Formula 2), the capping ratio is diisocyanate molar ratio / polyol molar ratio.