JP4924488B2 - Process for producing fiber comprising thermoplastic cellulose fatty acid mixed ester composition - Google Patents

Description

  In the present invention, when multi-spinning is performed with a single die, the difference in fineness between the yarns and the single fibers constituting the yarn is small, and there is no quality unevenness in the longitudinal direction of the fiber. The present invention relates to a production method capable of stably obtaining a fiber comprising a cellulose fatty acid mixed ester composition for a long time.

  Cellulose-based materials such as cellulose esters and cellulose ethers are currently attracting a great deal of attention as biomass materials that are most produced on the earth and as biodegradable materials in natural environments. Known cellulose-based fibers include regenerated cellulose fibers such as viscose rayon and cupra, and cellulose acetate fibers such as cellulose diacetate and cellulose triacetate. None of these fibers can be fiberized by a melt spinning method because the composition does not have thermoplasticity, or the temperature at which thermoplasticization occurs is equal to or higher than the thermal decomposition temperature, and a solvent is used. Manufactured by a wet or dry spinning method. On the other hand, as a novel cellulose fiber in recent years, a composition obtained by adding a plasticizer to a cellulose fatty acid mixed ester for the purpose of reducing environmental burden and improving productivity by the melt spinning method is used at a temperature lower than the thermal decomposition temperature of the composition. Techniques for improving thermal fluidity and performing melt spinning are disclosed (see Patent Documents 1 to 3).

  In melt spinning, it is usual that a large number of single fibers spun from a spinneret converge into one and wind up as a single thread, but in order to increase production efficiency, the number of discharge holes of the spinneret A method is adopted in which the number of yarns is divided into two or more yarns from one base and then wound. When performing such multi-yarn winding, if the fineness of each yarn is not accurate, when processed into a woven or knitted fabric using these yarns, there are warps, horizontal spots, glossy spots, etc. A low-grade woven or knitted fabric is not preferable. In order to suppress the fineness difference between the yarns spun from one spinneret, the fineness difference between the single fibers constituting the yarn, and the thickness unevenness in the longitudinal direction of the fiber, it is discharged from each discharge hole. It is necessary to make the amount of polymer uniform and to cool the spun single fiber uniformly.

  Patent Document 3 proposes a thermoplastic cellulose ester-based multifilament excellent in uniformity, in which the fiber longitudinal direction and the single yarn constituting the yarn are small in thickness unevenness. In this document, fibers having a small thickness unevenness between single yarns are obtained by setting the distance between discharge hole centers and the pressure on the back of the base in a specific range, but in this document, the number of single fibers constituting the yarn is When the number of yarns is at most 48 and this is a two-thread take-up, it becomes impossible to secure a specific distance between the discharge holes, resulting in occurrence of thickness unevenness in the longitudinal direction of the fiber, and the yarn operability is improved. It will get worse.

  On the other hand, with respect to a technique for winding multiple yarns from a single die using a thermoplastic polymer such as polyester or polyamide, a technique for suppressing fineness between yarns and between single fibers constituting the yarn is disclosed. (Patent Documents 4 to 6).

  Patent Document 4 discloses a method of reducing yarn breakage by suppressing gelation, reducing variation in fineness between yarns, and stably spinning two or more deformed cross-sectional yarns per die. When this method is applied to a thermoplastic cellulose fatty acid mixed ester composition, the difference in fineness between yarns can be suppressed to some extent, but the thickness variation in the longitudinal direction of the obtained yarn is very large, and stable yarn production is difficult. It is.

  Patent Document 5 discloses a multi-thread spinneret that can efficiently spin a monofilament having no fineness between filaments. When the spinneret is applied to a thermoplastic cellulose fatty acid mixed ester composition, the difference in fineness between yarns can be suppressed, but when the number of filaments is increased, the unevenness in the longitudinal direction of the fibers becomes large, and stable spinning is difficult. is there. In addition, since two or more measuring plates are installed for one nozzle plate, there is a great limitation on the development of multifilaments and multifilaments.

  Furthermore, Patent Document 6 discloses a method that can stably melt-spin fibers of good quality without causing unevenness in the thickness between fibers, with respect to the melt-spinning technique of deformed cross-section fibers having a small single yarn fineness. . When this method is applied to a thermoplastic cellulose fatty acid mixed ester composition, the difference in fineness between yarns can be suppressed to some extent, but the thickness variation in the longitudinal direction of the obtained fibers is still very large, and stable spinning is difficult. It is.

Thus, using the thermoplastic cellulose fatty acid mixed ester composition, two or more yarns are spun by a single die, the fineness between the yarns and the single fibers constituting the yarns is small, and the thickness in the longitudinal direction of the fibers. There was no method for obtaining fibers with small spots with good operability.
JP 2004-27378 A JP 2004-2111278 A JP 2006-1118060 A JP 59-47414 A JP-A-9-268419 JP 2005-60883 A

  The present invention is intended to solve the above-mentioned conventional problems, and when spinning two or more yarns with a single die, the fineness difference between yarns and the fineness unevenness between the single fibers constituting the yarn are small. Furthermore, another object of the present invention is to provide a production method in which fibers comprising a thermoplastic cellulose fatty acid mixed ester composition having excellent quality and small fine spots in the fiber longitudinal direction can be obtained stably for a long time.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have achieved excellent quality by adopting spinning conditions that satisfy specific requirements when melt spinning the thermoplastic cellulose fatty acid mixed ester composition. The inventors have found a production method capable of stably obtaining fibers for a long time, and have completed the present invention.

  That is, the gist of the present invention is as follows.

According to a first aspect of the present invention, there is provided a fiber comprising a thermoplastic cellulose fatty acid mixed ester composition, wherein the thermoplastic cellulose fatty acid mixed ester composition satisfies the following requirements when melt spinning two or more yarns per die: It is a manufacturing method.
(1) The measuring plate (B) for supplying the composition is installed immediately above the die plate (A) having a round cross-section discharge hole and / or a modified cross-section discharge hole.
(2) For the group of two or more discharge holes (A1) installed in the base plate (A), there is an introduction hole (A2) of the discharge hole group, and a measuring plate ( The discharge hole (B1) of B) is installed.
(3) The measuring plate (B) is installed at a position 5 to 30 mm above the lower surface of the base plate (A).

  The second invention comprises the thermoplastic cellulose fatty acid mixed ester composition according to the first invention, wherein the thermoplastic cellulose fatty acid mixed ester composition is cellulose acetate propionate or cellulose acetate butyrate. It is a manufacturing method of a fiber.

  According to the present invention, by adopting specific melt spinning conditions, the difference in fineness between the yarns and the fineness unevenness between the single fibers constituting the yarn are small, and further the fine unevenness in the fiber longitudinal direction is also small. It becomes possible to obtain a fiber made of a thermoplastic cellulose fatty acid mixed ester composition having an excellent quality with a good spinning maneuverability.

  Hereinafter, the manufacturing method of the fiber which consists of the thermoplastic cellulose fatty acid mixed ester composition of this invention is demonstrated in detail.

  The thermoplastic cellulose fatty acid mixed ester composition in the present invention is a composition comprising at least a cellulose fatty acid mixed ester and a plasticizer.

  Cellulose fatty acid mixed esters are those in which three hydroxyl groups present in the glucose unit of cellulose are blocked by two or more acyl groups. From the viewpoint of thermal fluidity, yarn maneuverability, cost, etc. Cellulose acetate propionate having an acetyl group and a propionyl group and cellulose acetate butyrate having an acetyl group and a butyryl group are preferred.

  The plasticizer is preferably a polyhydric alcohol compound, specifically, a polyalkylene glycol or glycerin compound having good compatibility with a cellulose fatty acid mixed ester and a remarkable thermoplastic effect capable of melt spinning. , Caprolactone compounds and the like, and polyalkylene glycol is particularly preferable.

  The thermoplastic cellulose fatty acid mixed ester composition in the present invention has a matting agent, deodorant, flame retardant, yarn friction reducing agent, anti-coloring agent, coloring pigment, dye, antistatic agent, as long as the physical properties are not impaired. As the antibacterial agent, ultraviolet absorber, infrared absorber, crystal nucleating agent, fluorescent brightener, etc., inorganic fine particles and organic compounds can be contained as required.

  In the present invention, when the thermoplastic cellulose fatty acid mixed ester composition is melt-spun by two or more yarns per die, as shown in FIGS. 1a and 1b, a die plate having round cross-section discharge holes and / or irregular cross-section discharge holes (A It is important that a measuring plate (B) is installed immediately above.

  The thermoplastic cellulose fatty acid mixed ester composition of the present invention has a characteristic that the melt viscosity is very dependent on the shear rate. The relationship between shear rate and melt viscosity is completely different from that of flexible polymers such as polyethylene terephthalate (PET) and nylon 6 (N6). Like liquid crystal polyester, the viscosity behavior changes linearly from the low shear rate region. As shown, the shear rate dependence of melt viscosity is 1.3 to 3.0 times higher than PET. Therefore, even if spinning is performed using a normal single-piece spinneret (FIG. 3), the apparent melt viscosity of the thermoplastic cellulose fatty acid mixed ester composition becomes very low, so that a sufficient back pressure cannot be secured. . In order to sufficiently secure the back pressure, there are methods of reducing the diameter of the discharge hole (A1) and increasing the length of the hole. In the former method, the present composition has a narrow spinning region, and the discharge hole Since the shear stress at the time of passing becomes high, sharkskin, melt fracture, etc. are generated on the spun yarn, making it difficult to produce a stable yarn, and clogging of discharge holes is likely to occur during operation. On the other hand, the latter technique causes a problem that the spinneret before and after use is not sufficiently cleaned. Also, when melt-spun irregular cross-section yarns, unless the processing accuracy of the discharge holes (slit width, length, hole length, etc.) (A1) is very high, the shear rate when passing through the discharge holes will vary between the discharge holes. It will change and the melt viscosity of a composition will change a lot. As a result, polymer discharge amount unevenness occurs between the discharge holes, resulting in a difference in fineness between the single fibers. There is a limit to increasing the processing accuracy, and if the processing accuracy is to be increased, the production cost of the spinneret inevitably increases. However, by adopting the above spinneret configuration, it becomes possible to individually set a predetermined back pressure for a plurality of discharge hole (A1) groups provided in the die plate (A), and to form irregular holes. Even when the melt spinning used is performed, the measurement plate (B) can ensure accurate measurement and can suppress the discharge amount unevenness of the composition in each discharge hole. As a result, the fineness unevenness of the single fiber constituting the yarn can be suppressed, and the fineness difference between the yarns can also be suppressed.

  In addition to the perfect circle, the shape of the discharge hole (A1) of the base plate is multi-leaf, flat, elliptical, W-shaped, S-shaped, X-shaped, H-shaped, C-shaped, rice-shaped, well-shaped, hollow, etc. Can be used.

  On the other hand, the shape of the discharge hole (B1) of the measuring plate is preferably a round cross section from the viewpoints of workability and uniformity of the amount of the melt spinning composition supplied to the introduction hole (A2) of the die plate.

  The discharge hole (A1) of the base plate is composed of the introduction hole (B2) of the measurement plate, the discharge hole (B1), and the introduction hole (A2) and discharge hole (A1) of the base plate following them. From the viewpoint of suppressing abnormal stagnation in the passing portion of the thermoplastic cellulose fatty acid mixed ester composition, it is preferable to use the spinneret configuration shown in FIG. 1b.

  In the present invention, it is important that the measuring plate (B) is installed at a position 5 to 30 mm above the lower surface of the base plate (A) (corresponding to L1 in the figure). The melt viscosity behavior of the thermoplastic cellulose fatty acid mixed ester composition is greatly different from that of polyester and polyamide, and is not only highly shear rate dependent but also temperature dependent. That is, the melt viscosity of PET or N6 has a small viscosity change due to a temperature change, and the temperature dependence of the melt viscosity is small. However, the melt viscosity of the thermoplastic cellulose fatty acid mixed ester composition used in the present invention has a large viscosity change due to a temperature change. Specifically, it is about 1.5 to 3.0 times larger than PET or N6. In the case of this composition, if there is a temperature spot where the composition passes during melt spinning, the melt viscosity will change greatly. Therefore, if there is a temperature spot in the place where the composition passes, the amount of the composition supplied to each discharge hole varies, which leads to a difference in fineness between single fibers and yarns.

  Even though the spinneret is heated by the spin block, the spinneret surface is in contact with the outside air. Naturally, temperature spots are generated on the spinneret surface, not at the same temperature, on the outside of the spinneret close to the spin block and on the spinneret center far from the spin block. Therefore, in the spinneret (FIG. 3) constituted by one normal sheet, the discharge amount unevenness increases due to the temperature unevenness on the base surface and the discharge hole. However, since the measuring plate (B) is installed at a position 5 mm or more above the lower surface of the base plate (A), the measuring plate itself is installed in a place with a small temperature spot (inside the spinning pack). The melt viscosity spots are also reduced. Accordingly, the uniformity of the amount of the composition supplied to the discharge hole (B1) of the measuring plate is increased, and as a result, the amount of the composition discharged from the die plate (A) is also increased. The difference in fineness between them is small, and the fineness unevenness between the single fibers constituting the yarn is also small. Further, when spinning a modified cross-section yarn, distribution spots of the composition to each hole can be suppressed with a measuring plate having a round hole that can improve the processing accuracy as compared with the modified hole, and unevenness in discharge amount can also be suppressed.

  The upper limit of the measurement plate installation position is 30 mm, and even if it is installed at this position or more, the effect of improving the fineness difference between yarns and single fibers can no longer be seen, and the thickness of the spinneret itself increases, Handling and production cost of the spinneret become impractical. The installation position of the weighing plate is more preferably 8 mm or more, and further preferably 10 mm or more.

  In the present invention, when the back pressure of the base of the base plate (A) and the measuring plate (B) is P (A) and P (B), respectively, it is preferable that P (A) + P (B) is 3 MPa or more. . By setting the pressure to 3 MPa or more, the pressure on the back surface of the die is sufficient, and the distribution of the composition is improved. The sum of the back pressures of the die is more preferably 4 MPa or more, and further preferably 5 MPa or more. On the other hand, it is preferable that the upper limit of the sum of the back pressures of the die is 20 MPa or less. The period until the pressure in the spinning pack gradually rises and reaches the pressure resistance (upper limit) value due to the influence of foreign matter trapped in the filter or filtration layer installed in the spinning pack by setting it to 20 MPa or less Is sufficient, and there is no need to change the spinning pack frequently, and productivity does not decrease. The sum of the back pressures of the die is more preferably 18 MPa or less, and further preferably 16 MPa or less.

  In the present invention, the composition is supplied to the introduction hole (A2) of the discharge hole group with respect to the discharge hole group (FIG. 4) composed of two or more discharge holes (A1) installed in the base plate (A). It is important that the discharge hole (B1) of the measuring plate (B) to be installed is installed. Even if the fineness difference between the single fibers constituting the yarns and the single fibers constituting the yarns can be suppressed, if the cooling spots of the single fibers constituting the yarns spun from the discharge holes (A1) of the base plate are generated, the fibers Thickness unevenness occurs in the longitudinal direction, and when processing into a knitted or knitted fabric, fluff or thread breakage occurs, or when dyeing is performed, it causes defects such as partially strong dyed spots and dyed streaks. Since the composition of the present invention has a large temperature dependency of the melt viscosity as described above, the cooling and solidification of the yarn spun from the spinneret rapidly proceeds. In general spinning equipment, a system (uniflow type) that cools the polymer discharged from a circular spinneret from one direction is adopted, and the single fiber on the side close to the cooling air blowing surface is uniformly cooled. On the other hand, the single fiber located on the far side is difficult to pass through the cooling air, so that it is not uniformly cooled and thick spots occur. However, because the discharge hole (A1) provided in the base plate has a county structure, the cooling air can pass smoothly between the counties, so that the single fiber far from the cooling air blowing surface can be cooled uniformly. It becomes. Therefore, the obtained fiber has no thickness unevenness in the longitudinal direction and is excellent in quality.

  The discharge hole interval (L2) in the discharge hole group (FIG. 4) provided in the base plate of the present invention is preferably 0.8 mm or more. The discharge hole interval (L2) refers to the distance from each discharge hole to the nearest other discharge hole. When the discharge hole interval (L2) is less than 0.8 mm, the composition discharged from the die hole is fused with the composition discharged from another discharge hole before being cooled and solidified, and stable yarn production is difficult. Become. The discharge hole interval (L2) is more preferably 1.0 mm or more, and still more preferably 1.2 mm or more.

  The number of discharge holes (A1) present in one discharge hole group (FIG. 4) is preferably 10 or less. By setting it to 10 or less, the discharge hole interval can be maintained at 0.8 mm or more, the single fiber can be uniformly cooled, and unevenness in the fiber longitudinal direction can be suppressed. The number of discharge holes is more preferably 9 or less, and still more preferably 8 or less. The discharge holes (A1) included in the discharge hole group are preferably arranged concentrically.

  When melt-spinning the thermoplastic cellulose fatty acid mixed ester composition of the present invention, the spinning temperature is preferably 280 ° C. or lower. Increasing the spinning temperature can reduce the shear rate dependency and temperature dependency of the melt viscosity of the composition, but increasing the spinning temperature is close to the thermal decomposition temperature of the cellulose fatty acid mixed ester in the composition. Thus, the thermal decomposition proceeds remarkably and the resulting fiber is colored, the mechanical properties are deteriorated, and the spinning operability is greatly deteriorated. Therefore, the spinning temperature is preferably 280 ° C. or lower. The lower limit of the spinning temperature may be appropriately set depending on the melting point of the cellulose fatty acid mixed ester, and is preferably (melting point + 20) ° C. or higher from the viewpoint of the thermal fluidity of the composition and the yarn-manufacturability.

The fiber comprising the thermoplastic cellulose fatty acid mixed ester composition thus obtained has the following characteristics (1) to (3). The weaving and knitting process is carried out on the weaving and knitting process using superior quality cellulose cellulose fatty acid mixed ester fibers with small differences in fineness between yarns and single fibers constituting the yarns, and also small thickness variation in the longitudinal direction of the fibers. Even in this case, it is possible to suppress the occurrence of stops and fluff due to yarn breakage. Furthermore, when it is made into a fabric form such as woven fabric or knitted fabric, straight lines and horizontal spots do not occur, and even after dyeing, no dyed spots or dyed streaks occur, and it is high quality and excellent in leveling. A fabric can be obtained.
(1) Fineness CV% between yarns is 1.0% or less. The fineness CV% between the yarns is an index representing fineness unevenness between the yarns when two or more yarns are spun with a single die. When the fineness CV% between the yarns is 1.0% or less, the difference in fineness between the yarns is small, so when these yarns are used to make a woven or knitted fabric, warp, horizontal spots, glossy spots, etc. Such a disadvantage does not occur.
(2) The fineness CV% of the single fiber constituting the yarn is 5% or less. The fineness CV% of the single fiber is an index of the diameter unevenness of the constituent fiber in the cross-sectional direction of the yarn. If this patch is large, in other words, if there is a single fiber with a fineness smaller than the average fineness, there is a problem that when processing into a woven or knitted fabric, the single fiber with a fineness is cut and becomes fluffy, and it is easy to stop. If there is a single fiber having a fineness larger than the average fineness, it tends to become dark when dyed, and stripes tend to occur. However, when the fineness CV% of the single fiber is 5% or less, such a problem does not occur, and the process passability and leveling property are improved.
(3) Fineness fluctuation value U% (half inert) is 1.2% or less. The fineness variation value is an index representing the thickness unevenness in the fiber longitudinal direction, and the smaller this value, the better the uniformity of the thickness in the fiber longitudinal direction. If U% is 1.2% or less, the single fibers constituting the yarn are uniformly cooled, so that the runnability of the spun yarn is stable and the yarn operability is good. When processing, fluff and yarn breakage do not occur, and even if dyeing is performed, defects such as partially strong dyed spots and dyed streaks do not occur, and a high-quality woven or knitted fabric is obtained.

Hereinafter, the present invention will be described in more detail with reference to examples. In addition, each characteristic value in an Example was calculated | required with the following method.
A. Average substitution degree of cellulose fatty acid mixed ester 0.9 g of dried cellulose fatty acid mixed ester dried at 80 ° C. for 8 hours was weighed and dissolved by adding 35 ml of acetone and 15 ml of dimethyl sulfoxide, and further 50 ml of acetone was added. While stirring, 30 ml of 0.5N sodium hydroxide aqueous solution was added and saponified for 2 hours. After adding 50 ml of hot water and washing the side of the flask, it was titrated with 0.5N sulfuric acid using phenolphthalein as an indicator. Separately, a blank test was performed in the same manner as the sample. The supernatant of the solution after titration was diluted 100 times, and the composition of the organic acid was measured using an ion chromatograph. From the measurement result and the acid composition analysis result by ion chromatography, the substitution degree was calculated by the following formula.

TA = (B−A) × F / (1000 × W)
DSace = (162.14 × TA) / [{1− (Mwase− (16.00 + 1.01)) × TA} + {1− (Mwacy− (16.00 + 1.01)) × TA} × (Acy / Ace)]
DSacy = DSace × (Acy / Ace)
TA: Total organic acid amount (ml)
A: Sample titration (ml)
B: Blank test titration (ml)
F: titer of sulfuric acid W: sample weight (g)
DSace: Average substitution degree of acetyl group DSacy: Average substitution degree of acyl group Mwash: Molecular weight of acetic acid Mwacy: Molecular weight of other organic acids Acy / Ace: Molar ratio of acetic acid (Ace) to other organic acids (Acy) 162 .14: Molecular weight of cellulose repeating unit 16.00: Atomic weight of oxygen 1.01: Atomic weight of hydrogen Fineness and fineness between yarns CV%
It measured using the measuring machine made from INTEC in the environment of temperature 20 degreeC and humidity 65% RH. The number of measurements was 5, and the average value was defined as the fineness.

  Further, from the fineness of the yarn obtained from the same die, the fineness CV%, which is an index of the fineness variation, was calculated by the following formula. However, X1 is an average value of the yarn, and σ1 is a standard deviation.

Fineness CV% between yarns = (σ1 / X1) × 100
C. Fineness CV% of the single fiber composing the yarn
The single yarn fineness CV% was used as an index of the fineness variation between the single yarns constituting the yarn, and the following formula was used. However, X2 is the average value of the fineness of the single fiber which comprises a thread | yarn, (sigma) 2 is a standard deviation.

Fineness CV% of single fiber = (σ2 / X2) × 100
The fineness of a single fiber is obtained by cutting the obtained yarn perpendicularly to the fiber axis direction, photographing the cut surface with an optical microscope, and measuring the diameter of each single fiber constituting the yarn from the obtained image. And the fineness of each single fiber was computed from the value.
D. Fineness variation (U%)
The U% measurement (half mode) was performed under the following conditions using a Worcester tester 4-CX manufactured by Zerbegger Worcester. The number of measurements was 5, and the average value was U%.

Measurement speed: 200 m / min Measurement time: 2.5 minutes Measurement fiber length: 500 m
Twist: S twist, 12000 / m
E. Back pressure of the base The pressure value is recorded on the recorder from the time when the thermoplastic cellulose fatty acid mixed ester composition is introduced into the spin pack until it is discharged from the spinneret, and the pressure rises when the spinneret passes from the obtained pressure chart. The measured pressure value was read and used as the back pressure of the weighing plate and the base plate.
F. Evaluation of yarn maneuverability When collecting 10 kg of one yarn, yarn maneuverability was evaluated based on the number of times of yarn breakage, and ○ was accepted.

○: Number of times of thread breakage is 0 to 1 time ×: Number of times of thread breakage is 2 times or more Synthesis Example 1
To 100 parts by weight of cellulose (cotton linter), 240 parts by weight of acetic acid and 67 parts by weight of propionic acid were added and mixed at 50 ° C. for 30 minutes. After the mixture was cooled to room temperature, 172 parts by weight of acetic anhydride cooled in an ice bath and 168 parts by weight of propionic anhydride were added as an esterifying agent, and 4 parts by weight of sulfuric acid was added as an esterification catalyst, followed by stirring for 150 minutes. An esterification reaction was performed. In the esterification reaction, when it exceeded 40 ° C., it was cooled in a water bath. After the reaction, a mixed solution of 100 parts by weight of acetic acid and 33 parts by weight of water was added as a reaction terminator over 20 minutes to hydrolyze excess anhydride. Thereafter, 333 parts by weight of acetic acid and 100 parts by weight of water were added, and the mixture was heated and stirred at 80 ° C. for 1 hour. After completion of the reaction, an aqueous solution containing 6 parts by weight of sodium carbonate was added, and the precipitated cellulose acetate propionate (CAP) was filtered off, washed with water, dried at 60 ° C. for 4 hours, and CAP (acetyl). The average degree of substitution of the group was 2.0, the average degree of substitution of the propionyl group was 0.7, and the melting point was 228 ° C.). 80% by weight of this CAP, 19.8% by weight of polyethylene glycol (PEG 600) having an average molecular weight of 600, and bis (2,6-di-t-butyl-4-methylphenyl) pentaerythritol diphosphite as a phosphorus antioxidant. 2 wt% was kneaded at 235 ° C. using a biaxial extruder and cut to about 5 mm to obtain thermoplastic cellulose fatty acid mixed ester composition pellets.

Example 1
The thermoplastic cellulose fatty acid mixed ester composition produced in Synthesis Example 1 was melted at 255 ° C., introduced into a spinning pack at a spinning temperature of 260 ° C., and the spinneret (B1: pore diameter / hole length = 0.25 / 0.75, A1: hole diameter / hole length = 0.23 / 0.46, unit: mm), and two yarns were discharged from one cap. The spun yarn is cooled and solidified with a cooling device (uniflow type) having a cooling length of 1 m with cooling air having a wind temperature of 20 ° C. and a wind speed of 0.5 m / second, and an oil supply device is placed at a position 1800 mm below the spinneret. The oil agent is applied and converged, taken up by the first godet roller (speed 2000 m / min), and wound by the winder via the second godet roller rotating at the same speed as the first godet roller. Taken (set variety 100 dtex-24 filament-round section).

  The fineness of each obtained yarn was 99.5 dtex, 100.8 dtex, the fineness CV% was 0.65%, and the fineness difference between the yarns was small. Further, the fineness CV% of the single fiber of each yarn was 3.5% and 3.7%, and the fineness unevenness between the single fibers was small and the fineness uniformity was excellent.

  Furthermore, the fineness variation values (U%) of the obtained yarns were 0.6 and 0.7, respectively, and the thickness unevenness in the fiber longitudinal direction was also small.

  When the yarn operability was evaluated, the yarn breakage was zero and the yarn operability was good.

Example 2
The thermoplastic cellulose fatty acid mixed ester composition produced in Synthesis Example 1 is melted at 255 ° C., introduced into a spinning pack at a spinning temperature of 260 ° C., and a spinneret having four discharge holes (A1) in the configuration of FIG. 1a. Using (B1: hole diameter / hole length = 0.25 / 0.75, A1: hole diameter / hole length = 0.20 / 0.60, unit: mm), two yarns were discharged from one cap. The spun yarn is cooled and solidified with a cooling device (uniflow type) having a cooling length of 1 m with cooling air having a wind temperature of 20 ° C. and a wind speed of 0.5 m / second, and an oil supply device is placed at a position 1800 mm below the spinneret. Use the oil agent to converge it, take it with the first godet roller (speed 1800 m / min), wind it with the winder via the second godet roller rotating at the same speed as the first godet roller (Set variety 100 dtex-48 filament-round section).

  The fineness of the obtained yarns was 100.5 dtex, 101.3 dtex, the fineness CV% was 0.40%, and the fineness difference between the yarns was small. Further, the fineness CV% of the single fiber of each yarn was 3.1% and 3.3%, and the fineness unevenness between the single fibers was small, and the fineness uniformity was excellent.

  Further, the fineness variation values (U%) of the obtained yarns were 0.8 and 0.8, respectively, and the thickness unevenness in the fiber longitudinal direction was small.

  When the yarn operability was evaluated, the yarn breakage was once and the yarn operability was good.

Example 3
The thermoplastic cellulose fatty acid mixed ester composition produced in Synthesis Example 1 is melted at 260 ° C., introduced into a spinning pack at a spinning temperature of 260 ° C., and a spinneret having five discharge holes (A1) in the configuration of FIG. 1b. Using (B1: hole diameter / hole length = 0.4 / 1.0, A1: slit width / slit length = 0.08 / 0.2, unit: mm), three yarns were discharged from one die. The spun yarn is cooled and solidified with a cooling device (uniflow type) having a cooling length of 1 m with cooling air having a wind temperature of 20 ° C. and a wind speed of 0.5 m / second, and an oil supply device is placed at a position 1800 mm below the spinneret. Use the oil agent to make it converge, take it up with a first godet roller (speed 1500 m / min), and wind it with a winder via a second godet roller that rotates at the same speed as the first godet roller Taken (set variety 80 dtex-20 filament-trilobal cross section).

  The fineness of each of the obtained yarns was 80.1 dtex, 79.5 dtex, 81.0 dtex, the fineness CV% was 0.77%, and the fineness difference between the yarns was small. Further, the fineness CV% of the single fibers was 3.4%, 4.0%, and 3.5%, and the fineness unevenness between the single fibers was small and the fineness uniformity was excellent.

  Further, the fineness variation values (U%) of the obtained yarns were 0.9, 0.8, and 0.9, respectively, and the thickness unevenness in the fiber longitudinal direction was small.

  When the yarn operability was evaluated, the yarn breakage was zero and the yarn operability was good.

Synthesis example 2
Eastman Chemical Cellulose Acetate Propionate (CAP482-20, acetyl group substitution degree 0.1, propionyl group substitution degree 2.5, melting point 195 ° C.) 90% by weight and average molecular weight 600 polyethylene glycol (PEG 600) 10% % Was kneaded at 210 ° C. using a biaxial extruder and cut to about 5 mm to obtain thermoplastic cellulose fatty acid mixed ester composition pellets.

Example 4
The thermoplastic cellulose fatty acid mixed ester composition produced in Synthesis Example 2 is melted at 240 ° C., introduced into a spinning pack at a spinning temperature of 245 ° C., and a spinneret having three ejection holes (A1) in the configuration of FIG. 1b. Using (B1: hole diameter / hole length = 0.35 / 0.7, A1: hole diameter / hole length = 0.08 / 0.72, unit: mm), two yarns were discharged from one cap. The spun yarn is cooled and solidified with a cooling device (uniflow type) having a cooling length of 1 m with cooling air having a wind temperature of 20 ° C. and a wind speed of 0.5 m / second, and an oil supply device is placed at a position 1800 mm below the spinneret. The oil agent is applied and converged, taken up by the first godet roller (speed 2000 m / min), and wound by the winder via the second godet roller rotating at the same speed as the first godet roller. Taken (set variety 150 dtex-36 filament-Yaba leaf cross section).

  The fineness of each obtained yarn was 150.3 dtex and 150.9 dtex, the fineness CV% was 0.2%, and the difference in fineness between yarns was small. Further, the fineness CV% of the single fibers was 2.4% and 2.7%, and the fineness irregularities between the single fibers were small, and the fineness uniformity was excellent.

  Further, the fineness variation values (U%) of the obtained yarns were 0.7 and 0.8, respectively, and the thickness unevenness in the fiber longitudinal direction was also small.

  When the yarn operability was evaluated, the yarn breakage was zero and the yarn operability was good.

Example 5
The thermoplastic cellulose fatty acid mixed ester composition produced in Synthesis Example 2 is melted at 240 ° C., introduced into a spinning pack at a spinning temperature of 240 ° C., and a spinneret having nine discharge holes (A1) in the configuration of FIG. 1b. (B1: hole diameter / hole length = 0.3 / 0.75, A1: hole diameter / hole length = 0.18 / 0.54, unit: mm), four yarns were discharged from one nozzle. The spun yarn is cooled and solidified with a cooling device (uniflow type) having a cooling length of 1 m with cooling air having a wind temperature of 20 ° C. and a wind speed of 0.5 m / second, and an oil supply device is placed at a position 1800 mm below the spinneret. Use the oil agent to make it converge, take it up with a first godet roller (speed 1500 m / min), and wind it with a winder via a second godet roller that rotates at the same speed as the first godet roller Taken (set variety 84 dtex-36 filament-round section).

  The fineness of the obtained yarns was 84.4 dtex, 83.7 dtex, 83.9 dtex, 84.8 dtex, the fineness CV% was 0.51%, and the fineness difference between the yarns was small. . Further, the fineness CV% of the single fibers was 3.8%, 4.0%, 3.9%, and 4.1%, and the fineness unevenness between the single fibers was small and the fineness uniformity was excellent.

  Moreover, U% of each obtained thread | yarn was a fineness fluctuation | variation value (U%) 0.9, 1.0, 1.1, 1.0, and the thickness unevenness in the fiber longitudinal direction was also a small thing.

When the yarn operability was evaluated, the yarn breakage was zero and the yarn operability was good.
Synthesis example 3
Eastman Chemical Cellulose Acetate Butyrate (CAB171-15, acetyl group average substitution degree 2.0, butyryl group average substitution degree 0.7, melting point = 232 ° C.) 85% by weight and an average molecular weight of 600 polyethylene glycol (PEG 600) 14.8% by weight and 0.2% by weight of bis (2,6-di-t-butyl-4-methylphenyl) pentaerythritol diphosphite as a phosphorus antioxidant at 240 ° C. using a biaxial extruder The mixture was kneaded and cut to about 5 mm to obtain CAB composition pellets.

Example 6
The thermoplastic cellulose fatty acid mixed ester composition produced in Synthesis Example 3 is melted at 260 ° C., introduced into a spinning pack at a spinning temperature of 260 ° C., and a spinneret having six discharge holes (A1) in the configuration of FIG. 1b. (B1: hole diameter / hole length = 0.25 / 0.75, A1: hole diameter / hole length = 0.16 / 0.48, unit: mm), two yarns were discharged from one cap. The spun yarn is cooled and solidified with a cooling device (uniflow type) having a cooling length of 1 m with cooling air having a wind temperature of 20 ° C. and a wind speed of 0.5 m / second, and an oil supply device is placed at a position 1800 mm below the spinneret. Use the oil agent to make it converge, take it up with a first godet roller (speed 1500 m / min), and wind it with a winder via a second godet roller that rotates at the same speed as the first godet roller Taken (set variety 150 dtex-72 filament-round section).

  The fineness of each obtained yarn was 151.1 dtex, 148.5 dtex, the fineness CV% was 0.87%, and the fineness difference between the yarns was small. Further, the fineness CV% of the single fibers was 4.8% and 4.5%, and the fineness unevenness between the single fibers was small and the fineness uniformity was excellent.

  Moreover, U% of each obtained thread | yarn was a fineness fluctuation | variation value (U%) 1.0 and 1.1, and the thickness spot in the fiber longitudinal direction was also a small thing.

  When the yarn operability was evaluated, the yarn breakage was zero and the yarn operability was good.

Comparative Example 1
Spinning was performed in the same manner as in Example 1 except that only the base plate (A1: hole diameter / hole length = 0.23 / 0.46, unit: mm) used in Example 1 was used.

  The fineness of each of the obtained yarns was 98.5 dtex, 101.6 dtex, the fineness CV% was 1.55%, and the fineness difference between the yarns was large. Moreover, the fineness CV% of the single fibers constituting each yarn was 8.4% and 9.3%, and the fineness unevenness between the single fibers was also large. On the other hand, the variation in fineness (U%) of each yarn was 0.9 and 0.8, respectively, and the thickness unevenness in the fiber longitudinal direction was small.

  When the yarn operability was evaluated, the yarn breakage was once and the yarn operability was good.

Comparative Example 2
Spinning was performed in the same manner as in Example 1 except that the thickness of the base plate was changed to 4 mm. The fineness of the obtained yarn was 98.7 dtex, 101.2 dtex, the fineness CV% was 1.25%, and the fineness difference between the yarns was large. Moreover, the fineness CV% of the single fibers constituting each yarn was 8.0% and 8.7%, and the fineness unevenness between the single fibers was also large. On the other hand, the fineness variation values (U%) of the respective yarns were 0.7 and 0.8, respectively, and the thickness unevenness in the fiber longitudinal direction was small.

  When the yarn operability was evaluated, the yarn breakage was zero and the yarn operability was good.

Comparative Example 3
Example except that the configuration of the spinneret is changed to FIG. 2 (B1: hole diameter / hole length = 0.25 / 0.75, A1: hole diameter / hole length = 0.23 / 0.46, unit: mm) Spinning was carried out in the same manner as in 1. The fineness of the obtained yarn was 99.1 dtex, 101.0 dtex, the fineness CV% was 0.95%, and the fineness difference between the yarns was small. Further, the fineness CV% of the single fibers constituting each yarn was 4.8% and 4.9%, and the fineness unevenness between the single fibers was also small.

  However, the fineness variation values (U%) of the obtained yarns were 3.8 and 4.2%, respectively, and the thickness unevenness in the fiber longitudinal direction was very large.

  As a result of evaluating the yarn operability, the running yarn was greatly swayed and the yarn breakage occurred three times, and the yarn operability was poor.

Reference example 1
Spinning was carried out in the same manner as in Comparative Example 1 except that polyethylene terephthalate having an intrinsic viscosity [η] of 0.63 (measured in orthochlorophenol at 25 ° C.) was used and the melting temperature and spinning temperature were changed to 290 ° C. The fineness of the obtained yarn was 100.3 dtex, 100.7 dtex, the fineness CV% was 0.2%, and the fineness difference between the yarns was small. The fineness CV% of the single fibers constituting each yarn was 2.0% and 1.9%, and the fineness unevenness between the single fibers was small and the fineness uniformity was excellent.

In addition, the fineness variation values (U%) of the obtained yarns were 0.4 and 0.4, respectively, and the thickness unevenness in the fiber longitudinal direction was small. Cutting was 0 times, and the yarn maneuverability was good.

Reference example 2
Spinning was carried out in the same manner as in Comparative Example 2 except that polyethylene terephthalate having an intrinsic viscosity [η] of 0.63 (measured in orthochlorophenol at 25 ° C.) was used and the melting temperature and spinning temperature were changed to 290 ° C. The fineness of the obtained yarn was 100.4 dtex and 100.7 dtex, the fineness CV% was 0.15%, and the fineness difference between the yarns was small. The fineness CV% of the single fibers constituting each yarn was 2.2% and 2.0%, and the fineness unevenness between the single fibers was small and excellent in fineness uniformity.

  Further, the fineness variation values (U%) of the obtained yarns were 0.5 and 0.4, respectively, and the thickness unevenness in the fiber longitudinal direction was small.

  When the yarn operability was evaluated, the yarn breakage was zero and the yarn operability was good.

Reference example 3
Spinning was carried out in the same manner as in Comparative Example 3 except that polyethylene terephthalate having an intrinsic viscosity [η] of 0.63 (measured in orthochlorophenol at 25 ° C.) was used and the melting temperature and spinning temperature were changed to 290 ° C. The fineness of the obtained yarn was 100.6 dtex, 100.8 dtex, the fineness CV% was 0.10%, and the fineness difference between the yarns was small. The fineness CV% of the single fibers constituting each yarn was 1.8% and 2.1%, and the fineness unevenness between the single fibers was small and the fineness uniformity was excellent.

  Further, the fineness variation values (U%) of the obtained yarns were 0.4 and 0.3, respectively, and the thickness unevenness in the fiber longitudinal direction was small.

  When the yarn operability was evaluated, the yarn breakage was zero and the yarn operability was good.

  When melt-spinning two or more yarns per die of a thermoplastic cellulose fatty acid mixed ester composition, the fineness between the yarns and between the single fibers constituting the yarn is small, and there is no thickness unevenness in the longitudinal direction of the fibers. Can be obtained stably, and can be suitably used especially for fibers comprising a cellulose acetate propionate composition and a cellulose acetate butyrate composition.

It is a longitudinal cross-sectional view of the example of the spinneret which combined the measuring plate and base plate of this invention. It is a longitudinal cross-sectional view of the example of the normal spinneret which combined the measuring plate and the nozzle | cap | die plate. It is a longitudinal cross-sectional view of the example of the spinneret which consists only of a nozzle | cap | die plate. It is the top view which showed an example of arrangement | positioning of the discharge hole in the discharge hole group of this invention.

Explanation of symbols

A: Base plate A1: Discharge hole of base plate A2: Inlet hole of base plate B: Measuring plate B1: Discharge hole of measuring plate B2: Introduction hole of measuring plate L1: Distance from bottom surface of base plate (measuring plate installation position)
L2: Discharge hole interval in the discharge hole group

Claims (2)

A method for producing a fiber comprising a thermoplastic cellulose fatty acid mixed ester composition, wherein the thermoplastic cellulose fatty acid mixed ester composition satisfies the following requirements when melt spinning two or more yarns per die.
(1) The measuring plate (B) for supplying the composition is installed immediately above the die plate (A) having a round cross-section discharge hole and / or a modified cross-section discharge hole.
(2) For the group of two or more discharge holes (A1) installed in the base plate (A), there is an introduction hole (A2) of the discharge hole group, and a measuring plate ( The discharge hole (B1) of B) is installed.
(3) The measuring plate (B) is installed at a position 5 to 30 mm above the lower surface of the base plate (A).   2. The method for producing a fiber comprising a thermoplastic cellulose fatty acid mixed ester composition according to claim 1, wherein the thermoplastic cellulose fatty acid mixed ester composition is cellulose acetate propionate or cellulose acetate butyrate.

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