JP5256970B2 - Melt spinning winding method and melt spinning winding device for cellulose fatty acid mixed ester fiber yarn - Google Patents

Description

  The present invention relates to a method for melt-spinning a cellulose fatty acid mixed ester fiber and a melt-spun winding, which makes it possible to stably produce a cellulose fatty acid mixed ester fiber excellent in mechanical properties, yarn quality, and yarn quality with good spinning properties. It relates to a take-off device.

Various methods have been proposed for the purpose of melt spinning and producing cellulose fatty acid mixed ester fibers having excellent mechanical properties and quality.
For example, regarding the production of cellulose fatty acid mixed ester fiber having a fineness of a single yarn (single fiber) fineness of 0.1 to 2 dtex, as shown in FIG. 3, the discharge surface of the spinneret and the blowout portion of the cooling air By defining the vertical distance Hu of the upper end of the fiber and suppressing the turbulence of the air flow directly below the spinneret, the thinning deformation behavior of the fiber yarn is stabilized, and the cross-sectional shape and fineness of the fiber (hereinafter referred to as Wooster's spot) are stabilized. (U%) is reduced, and the surface temperature of the spinneret is defined to improve not only the stability of yarn production but also the strength and elongation (Patent Document 1).

  However, the method proposed in Patent Document 1 uses a cross-flow cooling device 3b in which the cooling air crosses the fiber yarn as the cooling means as shown in FIG. When this cross-flow cooling / cooling device is used, as the number of single yarns increases, variation occurs in the way the cooling air strikes between the single yarns. As a result, the cooling air is not blown uniformly and the Wooster spots (U %) May cause variations.

  Further, for the purpose of improving the strength and elongation of the fiber, the spinning atmosphere is heated to a temperature higher than the surface temperature of the spinneret, and the atmospheric temperature 15 cm below the nozzle is heated to 260 to 340 ° C. A method is proposed in which the deformation (thinning deformation behavior) of the fiber yarn discharged from the die is moderated and the stress concentration is suppressed by reducing the deformation strain rate, thereby improving the strength and elongation. (Patent Document 2).

  However, although the method of Patent Document 2 can surely improve the strength and elongation, the means for cooling the fiber yarn uses a cross-flow cooling device, and the cooling air is blown between the single yarns. As a result, the U% is deteriorated.

  In addition, when manufacturing polyester fiber yarns, the cooling length of the annular cooling device is specified as a method for uniformly and stably cooling melt-spun fiber yarns and further improving the strength and elongation. In addition, the temperature profile of the cooling air with respect to the yarn running direction is provided with a temperature gradient (from high temperature to low temperature) from the upper part to the lower part in the yarn running direction to improve the strength and elongation by spinning orientation and to improve U% by uniform cooling. A method has been proposed (Patent Document 3).

  However, the method proposed in Patent Document 3 can obtain the desired effect as long as the molecular orientation is not hypersensitive to changes in the atmospheric temperature, such as polyester. I couldn't get any effect with the article.

As described above, melt spinning of cellulose fatty acid mixed ester fibers is not limited to the number of single yarns, and a melt spinning method that keeps U% small and high elongation is still established. There was no current situation.
JP 2007-169854 A JP 2005-248354 A JP 2007-284857 A

  In view of the above-described problems, the object of the present invention is to uniformly and stably cool the yarn discharged from the spinneret when the cellulose fatty acid mixed ester fiber is melt-spun and manufactured. It is an object of the present invention to provide a melt spinning winding method and a melt spinning winding device for cellulose fatty acid mixed ester fibers that can improve elongation.

The melt spinning winding method for cellulose fatty acid mixed ester fibers of the present invention that achieves the above-mentioned object has the following configuration (1) .
(1) When the cellulose fatty acid mixed ester fiber yarn mainly composed of the cellulose fatty acid mixed ester discharged from the spinneret is cooled and solidified, the cooling air is blown out from the annular direction toward the yarn and cooled. From the cooling air blowing part having the wind blowing length Lq, the cooling air is blown onto the fiber yarn under the conditions satisfying the following formulas (A), (B) and (C) to cool and solidify the yarn. A method for melt-spinning a cellulose fatty acid mixed ester fiber, characterized in that

Tm + 10 <= Tt <= Tm + 60 ... Formula (A)
Where Tt: cooling air temperature at the upper end of the cooling air outlet (° C)
Tm: Melting point of cellulose fatty acid mixed ester (° C.)
Td ≦ 40 Formula (B)
Where Td: cooling air temperature at the lower end of the cooling air outlet (° C.)
100 ≦ Lq ≦ 500 ......... Formula (C)
However, Lq: the length of the cooling air outlet (mm )

In addition, in the melt spinning winding method of the cellulose fatty acid mixed ester fiber of the present invention, the following (2) or (3) is preferable.
(2) The melt spinning of cellulose fatty acid mixed ester fiber according to (1), wherein the fiber yarn is discharged under the condition that the discharge surface temperature Ts of the spinneret satisfies the following formula (E): Winding method.

Tm + 25 ≦ Ts ≦ Tm + 50 (E)
Ts: Spinneret discharge surface temperature (° C)
Tm: Melting point of cellulose fatty acid mixed ester (° C.)
(3) The cellulose fatty acid mixed ester fiber according to (1) or (2) above, wherein a distance H between a discharge surface of the spinneret and an upper end surface of the cooling air blowing portion is 10 to 100 mm. Melt spinning winding method.

The melt spinning and winding device for cellulose fatty acid mixed ester fibers of the present invention that achieves the above-described object has the following configuration (4) or (5) .
(4) To cool and solidify the cellulose fatty acid mixed ester fiber yarn mainly composed of the cellulose fatty acid mixed ester discharged from the spinneret, an annular cooling device for blowing cooling air from the annular direction toward the yarn; A fiber having a take-up roller for taking up the yarn and a take-up device for taking up the yarn, wherein the annular cooling device discharges the cooling air whose flow rate is adjusted by the cooling air amount adjusting device from the spinneret; a cooling air blowing unit for blowing the yarn, and the cooling air of the upper portion of the cooling air blowing unit to a high temperature, a cooling air temperature control means for the low-temperature cooling air of a lower portion of the cooling air blowing unit a melt spinning reel device of a cellulose fatty acid mixed ester fibers mainly composed of cellulose fatty acid mixed ester, blowing length Lq of the cooling air blowing portion of the annular cooling apparatus, the following formula ( ) Melt spinning winding device of a cellulose fatty acid mixed ester fiber characterized by satisfying.
100 ≦ Lq ≦ 500 ......... Formula (F)
However, Lq: length of cooling air blowing part (mm)
(5) To cool and solidify the cellulose fatty acid mixed ester fiber yarn mainly composed of the cellulose fatty acid mixed ester discharged from the spinneret, an annular cooling device for blowing cooling air from the annular direction toward the yarn; A fiber having a take-up roller for taking up the yarn and a take-up device for taking up the yarn, wherein the annular cooling device discharges the cooling air whose flow rate is adjusted by the cooling air amount adjusting device from the spinneret; A cooling air blowing part for blowing on the yarn is provided, and the cooling air at the upper part of the cooling air blowing part is set to a high temperature satisfying the following formula (A), and the cooling air at the lower part of the cooling air blowing part is given by the following formula A melt spinning and winding device for cellulose fatty acid mixed ester fibers, the main component of which is a cellulose fatty acid mixed ester, having cooling air temperature control means for reducing the temperature to satisfy (B).
Tm + 10 <= Tt <= Tm + 60 ... Formula (A)
Where Tt: cooling air temperature at the upper end of the cooling air outlet (° C)
Tm: Melting point of cellulose fatty acid mixed ester (° C.)
Td ≦ 40 Formula (B)
Where Td: cooling air temperature at the lower end of the cooling air outlet (° C.)

In the melt spinning and winding device for cellulose fatty acid mixed ester fiber of the present invention (4) , specifically, the following (6) configuration is preferable.
(6) Cooling air temperature control means for raising the cooling air at the upper part of the cooling air outlet and lowering the cooling air at the lower part of the cooling air outlet, the cooling air at the upper part of the cooling air outlet is The cellulose fatty acid mixed ester as described in (4) above, wherein the cooling air blown from the cooling air temperature control means satisfying the equation (A) and satisfying the following equation (B): Fiber melt spinning winder.
Tm + 10 <= Tt <= Tm + 60 ... Formula (A)
Where Tt: cooling air temperature at the upper end of the cooling air outlet (° C)
Tm: Melting point of cellulose fatty acid mixed ester (° C.)
Td ≦ 40 Formula (B)
Where Td: cooling air temperature at the lower end of the cooling air outlet (° C.)

According to the melt spinning winding method of the cellulose fatty acid mixed ester fiber of claim 1 of the present invention and the melt spinning winding device of the fiber of claim 4 or 5, the cellulose fatty acid mixed ester fiber yarn is By arranging cooling air blowing holes having a specific direction of the cooling air and a specific cooling air temperature in an annular shape and cooling and solidifying, the cellulose fatty acid mixed ester fiber yarn can be cooled uniformly and stably, In addition, the strength and elongation can be improved.

  More specifically, it is possible to simultaneously improve the strength and elongation by slow cooling spinning of cellulose fatty acid mixed ester fiber yarns and to improve the U% by uniform cooling of the yarns, and the cellulose fatty acids with excellent mechanical properties. It becomes possible to stably produce mixed ester fibers in terms of both yarn production and quality.

  In the melt spinning method and melt spinning apparatus for cellulose fatty acid mixed ester fiber yarn of the present invention, the cooling air blowing part of the device for cooling and solidifying the fiber yarn blows the cooling air from the annular direction toward the yarn. It is important that the cooling air is blown in a direction intersecting the yarn running direction.

  Further, it is important that the blowing length Lq of the cooling air blowing portion having the cooling air blowing hole for the yarn discharged from the spinneret is in the range of 100 mm to 500 mm. The blowout length Lq of the cooling air blowing section here is the length in the yarn running direction of the region where the cooling air blows out. When the blowing length Lq is less than 100 mm, U% of the cellulose fatty acid mixed ester fiber deteriorates and the effect of improving the strength and elongation by slow cooling spinning becomes small. On the contrary, when the blowout length Lq exceeds 500 mm, the accompanying airflow generated after the cellulose fatty acid mixed ester fiber yarn spun from the spinneret is cooled and solidified becomes a disturbance, and the fiber yarn discharged from the spinneret is spun. The yarn is swayed directly under the base, the U% of the cellulose fatty acid mixed ester fiber is deteriorated, and the spinning tension is increased due to the effect of the accompanying air flow accompanying the running of the fiber yarn, so that the yarn forming property is remarkably deteriorated. A preferable range of the blowing length Lq is 120 to 450 mm.

  In the melt spinning method and melt spinning apparatus for cellulose fatty acid mixed ester fiber yarns according to the present invention, it is important to provide a cooling action so that the cooling air has a high temperature gradient at the upper part and a low temperature at the lower part. is there. The upper part here means a part close to the spinneret in the cooling air blowing part, and the lower part here means a part below the upper part. The upper part and the lower part are preferably divided into two equal parts of the cooling length L, but they are not necessarily divided into equal parts. For the cooling air, when the upper part is at a low temperature, uniform cooling of the cellulose fatty acid mixed ester fiber yarn is possible, but the effect of improving the strength and elongation cannot be obtained due to insufficient cooling, and conversely, when the lower part is at a high temperature, the cellulose fatty acid Since cooling of the mixed ester fiber yarn becomes insufficient, U% of the cellulose fatty acid mixed ester fiber is deteriorated.

  Since the cooling air has a temperature gradient in which the upper part has a high temperature and the lower part has a low temperature, the melting point of the cellulose fatty acid mixed ester is Tm (° C.), and the cooling air temperature Tt at the upper end of the cooling air outlet is Tm + 10 ≦ Tt It is important to be in the range of ≦ Tm + 60 (° C.).

  When the cooling air temperature at the upper end is less than Tm + 10 (° C.), the temperature of the discharge surface of the spinneret decreases, so melt fracture (a phenomenon that occurs when the polymer shear stress is high when passing through the spinneret discharge hole, is discharged The phenomenon in which the shape of the fiber yarn becomes irregular) occurs, or the spinning property of the fiber yarn is poor, so that the yarn production is remarkably deteriorated. On the other hand, if the temperature exceeds Tm + 60 (° C.), the temperature of the spinneret discharge surface becomes high, and the thermal deterioration of the polymer discharged from the spinneret advances, so that the yarn-making property is remarkably deteriorated and the fiber color tone is also deteriorated. It is not preferable from the viewpoint of equal quality. A preferable range of the cooling air temperature (Tt) at the upper end is Tm + 25 ≦ Tt ≦ Tm + 45 (° C.).

  Furthermore, it is important that the cooling air temperature Td at the lower end of the cooling air outlet is in the range of Td ≦ 40 ° C. When the cooling air temperature at the lower end exceeds 40 ° C., the yarn temperature at the oil supply position becomes high and the strength and elongation of the fiber are lowered. A preferable range of the cooling air temperature Td at the lower end is Td ≦ 30 ° C.

  Moreover, the melt spinning winding method of the cellulose fatty acid mixed ester fiber yarn of the present invention is such that the melting point of the cellulose fatty acid mixed ester is Tm (° C.) and the discharge surface temperature Ts (° C.) of the spinneret is Tm + 25 ≦ Ts ≦ Tm + 50. It is important to be in the range of (° C).

  When the discharge surface temperature (Ts) is less than Tm + 25 (° C.), melt fracture occurs, or the yarn-making property is remarkably deteriorated due to poor spinnability of the fiber yarn. On the other hand, if it exceeds Tm + 50 (° C.), thermal deterioration of the polymer discharged from the spinneret proceeds, and not only from the standpoint of quality such as deterioration of fiber color tone, but also from the viewpoint of quality.

  The cooling air used in the melt spinning method and melt spinning apparatus for cellulose fatty acid mixed ester fiber yarn of the present invention is preferably rectified. For example, by wrapping a ribbon with irregularities on its surface in a spiral shape to form a thermoset in a cylindrical shape, or by wrapping a wire mesh in a cylindrical shape to form a thermoset to make contact with the cooling air outlet, etc. There is a method of blowing the rectified cooling air, but there is no particular limitation as long as the rectified cooling air is uniformly blown onto the fiber yarn discharged from the spinneret.

  Further, the wind speed gradient of the cooling air can be adopted as shown in FIGS. 2A and 2B, and is not particularly limited. However, the cooling air speed from the cooling air blowing section is the cooling air speed. It is preferable that it is in the range of 0.05 to 1.0 m / sec at the maximum in a section of 50 mm from the upper end face of the blowing part. When the wind speed of the cooling air is less than 0.05 m / sec, cooling of the cellulose fatty acid mixed ester fiber yarn becomes insufficient, and therefore U% of the cellulose fatty acid mixed ester fiber may be deteriorated. On the other hand, if the wind speed of the cooling air exceeds 1.0 m / sec, the fiber yarn discharged from the spinneret may sway just below the spinneret and the yarn-making property may be deteriorated.

  As shown in FIG. 1, the melt spinning method and melt spinning apparatus for cellulose fatty acid mixed ester fiber yarns according to the present invention are horizontally arranged between the outermost periphery of the fiber yarn discharged from the spinneret and the upper end portion of the cooling air blowing portion. The distance (C) is preferably in the range of 5 to 20 mm. When the horizontal distance (C) is less than 5 mm, the fiber blown from the cooling air outlet and the spinneret may come into contact with each other, which may deteriorate the yarn forming property. On the contrary, if it exceeds 20 mm, cooling of the cellulose fatty acid mixed ester fiber yarn becomes insufficient, so that U% of the cellulose fatty acid mixed ester fiber may be deteriorated.

  Further, the vertical distance H between the discharge surface of the spinneret 2 shown in FIG. 1 and the upper end portion of the cooling air blowing portion 5 is preferably in the range of 10 to 100 mm. When the vertical distance H is less than 10 mm, the fiber yarn blows cooling air to the discharge surface of the spinneret. Therefore, the fiber yarn discharged from the spinneret sways directly under the spinneret, and the cellulose fatty acid mixed ester fiber As U% deteriorates, there is a possibility that the spinning tension becomes high due to the influence of the accompanying airflow accompanying the running of the fiber yarn, and the spinning performance is deteriorated. On the contrary, if it exceeds 100 mm, the fiber yarn is solidified, and U% of the cellulose fatty acid mixed ester fiber may be deteriorated. A more preferable range of the vertical distance H is 30 to 65 mm.

  The melt spinning method and melt spinning apparatus of the cellulose fatty acid mixed ester fiber yarn of the present invention may be appropriately selected according to the properties such as single yarn fineness, number of filaments, yarn cross section, and use. Among them, the varieties group exhibiting the effect particularly in the present invention is a cultivar group having a single yarn fineness of 3 dtex or less. Further, in terms of the cross-sectional shape described later, the effect is more effective when the single yarn fineness is 0.3 to 2.5 dtex in a normal circular cross-section, and the effect is more effective at 1.5 to 3 dtex in a modified cross-section.

  The cellulose fatty acid mixed ester in the present invention is one in which three hydroxyl groups present in the glucose unit of cellulose are blocked with two or more acyl groups. Specific examples of the cellulose fatty acid mixed ester are preferably cellulose acetate propionate in which an acetyl group and a propionyl group are bonded, and cellulose acetate butyrate in which an acetyl group and a butyl group are bonded. In this case, the average substitution degree of the acyl group preferably satisfies the following formula. The average degree of substitution refers to the number of acyl groups chemically bonded among the three hydroxyl groups present per glucose unit of cellulose.

2.0 ≦ (Average substitution degree of acyl group) ≦ 3.0
1.5 ≦ (average degree of substitution of acetyl group) ≦ 2.5
0.5 ≦ (average degree of substitution of propionyl group or butyl group) ≦ 1.5
The cellulose fatty acid mixed ester in the present invention is a resin composition mainly composed of a cellulose fatty acid mixed ester. The content of the cellulose fatty acid mixed ester is preferably in the range of 75 to 95% by weight. By setting it as such a range, the melt viscosity of the resin composition is lowered, and fiber formation by melt spinning can be performed stably with respect to yarn production and quality, and the strength and elongation of the obtained cellulose fatty acid mixed ester fiber are increased. The characteristics such as U% are also good. The more preferable range of the content of the cellulose fatty acid mixed ester is 78 to 92% by weight, and the most preferable range is 80 to 90% by weight.

  Further, the resin composition comprising the cellulose fatty acid mixed ester in the present invention may contain a plasticizer. As the plasticizer, a polyhydric alcohol compound is preferable. Specifically, polyalkylene glycols, glycerin compounds, caprolactone compounds, etc. that have good compatibility with cellulose fatty acid mixed esters and have a remarkable thermoplastic effect that can be melt-spun, especially polyalkylene glycols. Is most preferred. Specific examples of the polyalkylene glycol include polyethylene glycol having a weight average molecular weight of 200 to 4000, and include, but are not limited to, polypropylene glycol and polybutylene glycol. These are used alone or in combination. Can be used.

  Moreover, it is preferable that the plasticizer content in the resin composition which consists of cellulose fatty acid mixed ester exists in the range of 5 to 25 weight%. By setting the amount within this range, the heat flow characteristics of the cellulose fatty acid mixed ester can be improved, so that fiber formation by melt spinning can be performed stably in terms of both yarn production and quality. Properties such as elongation and U% are also good. The more preferable range of the plasticizer content is 8 to 22% by weight, and the most preferable range is 10 to 20% by weight.

  Furthermore, the resin composition comprising cellulose fatty acid mixed ester has a matting agent, deodorant, flame retardant, yarn friction reducing agent, anti-coloring agent, coloring pigment, dye, antistatic agent, antibacterial agent, ultraviolet absorber. In addition, inorganic fine particles and organic compounds may be included as infrared absorbers, crystal nucleating agents, fluorescent brighteners, and the like.

  The cross-sectional shape of the cellulose fatty acid mixed ester fiber in the present invention is not particularly limited, and may be a normal circular cross-section, or a multi-leaf shape such as a trilobe, five-leaf, or eight-leaf, a flat shape, An irregular cross section such as a W shape, an S shape, an X shape, an H shape, a C shape, a paddle shape, a well shape, or a hollow shape may be used. Moreover, the fiber form can take various fiber product forms, such as a long fiber, a short fiber, a nonwoven fabric, and a thermoforming body.

  The melt spinning method and melt spinning apparatus for cellulose fatty acid mixed ester fiber yarns of the present invention will be described in detail with reference to the drawings. FIG. 1 shows one embodiment of the melt spinning method for cellulose fatty acid mixed ester fiber yarns of the present invention. It is the schematic of the melt spinning apparatus which shows an aspect. The melt spinning apparatus includes a spinning pack 1, an annular cooling device 3 a, an oil supply guide 7, take-up rollers 9 and 10, and a winding device 11. The spin pack 1 has a spinneret 2, and the fiber yarn Y spun from the discharge hole of the spinneret 2 is cooled by cooling air blown from the annular cooling device 3 a, and an oil agent is supplied by an oil supply guide 7. After being applied, the interlace nozzle 8 is used for confounding. Then, it is taken up by take-up rollers 9 and 10 and taken up by a take-up device 11.

  In the melt spinning apparatus, the annular cooling device 3a has a cooling air blowing part (hole) 5, and the cooling air supplied from a temperature controller (not shown) is adjusted to an arbitrary air volume by the cooling air adjusting device 4. The cooling air is heated by passing through the annular cooling device 3a heated by the heating device 6, and is rectified by the cooling air blowing portion 5 and sprayed in a direction intersecting with the traveling direction of the fiber yarn Y. ing.

  The cooling length Lq of the cooling air blowing section 5 is divided into two equal parts, the one close to the spinneret being the upper part, and the other is divided into the lower part. The upper part is the cooling air in the channel heated to an arbitrary temperature by the heating device 6. Since the cooling air is heated by passing, the cooling air at the upper end of the cooling air blowing unit 5 reaches the highest temperature, and the cooling air blowing unit 5 that does not pass through the flow path heated to an arbitrary temperature by the heating device 6. Since the lower end portion has the lowest temperature, the upper and lower portions can have a temperature gradient, and the temperature control of the heating device 6 can control the temperature of the cooling air.

  Here, the heating device 6 is provided in the circumferential direction of the annular cooling device 3a. However, the heating device 6 is not particularly limited as long as it is a means that satisfies the temperature gradient of the present invention. For example, the spinning pack is heated. A means for heating the cooling air by applying heat from the melt spinning apparatus 12 or a heater (heating cylinder) that maintains an atmosphere directly below the spinneret (not shown) at a high temperature may be used.

  Further, FIG. 1 shows a melt spinning process of one yarn per spinneret, but there is no problem even when dealing with multiple yarns of two or more yarns per spinneret. In addition, the spinning speed (speed of the first take-up roller 9) is preferably 1000 to 4500 m / min. By setting the spinning speed to 1000 to 4500 m / min, the air resistance generated on the spinning line can be reduced, so that the spinning tension does not become extremely high and the spinning performance is improved. Furthermore, non-uniformity of the fiber internal structure due to rapid deformation of the fiber yarn discharged from the spinneret can be suppressed, and a fiber having excellent mechanical properties can be 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 The method for calculating the flatness of cellulose fatty acid mixed ester in which acetyl group and propionyl group are bonded to cellulose is as follows.

0.9 g of a cellulose fatty acid mixed ester chip having a moisture content of 500 ppm was weighed and dissolved by adding 35 ml of acetone and 15 ml of dimethyl sulfoxide, and then 50 ml of acetone was further 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− (Mwpro− (16.00 + 1.01)) × TA] × (Pro / Ace)]
DSpro = DSace × (Pro / Ace)
DSOH = 3-DSace-DSpro
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 DSpro: average substitution degree of propionyl group DSOH: average substitution degree of hydroxyl group Mwace: molecular weight of acetic acid Mwpro: molecular weight of propionic acid Pro / Ace: acetic acid (Ace) and propionic acid (Pro) Molar ratio 162.14: Molecular weight of repeating unit of cellulose 16.00: Atomic weight of oxygen 1.01: Atomic weight of hydrogen Melting point Tm (° C) of cellulose fatty acid mixed ester
A cellulose fatty acid mixed ester chip having a moisture content of 500 ppm was measured using a differential scanning calorimeter (DSC-7) manufactured by PerkinElmer Co., Ltd. under a temperature rising rate of 15 ° C./min. The temperature was the melting point Tm (° C.).
C. Cooling air temperature A thermocouple is provided in the immediate vicinity of the cooling air outlet 6 and the cooling air temperatures are measured at the positions of the upper end and the lower end of the cooling air outlet, and the respective temperatures are measured as the cooling air temperature Tt ( ° C) and the cooling air temperature Td (° C) at the lower end.
D. The discharge surface temperature of the spinneret is the discharge surface temperature adjacent to the discharge holes arranged on the outermost periphery of the discharge surface of the spinneret, and was measured by bringing a thermocouple into contact with the discharge surface.
E. Strength (Toughness)
Tensile strength (strength) and elongation (elongation) were measured according to Section 8.5 of JIS L1013 (1999). In addition, as a measurement condition, a constant speed tension type testing machine (Tensilon manufactured by Orientec Co., Ltd.) was used, and a grip interval was 50 cm and a tensile speed was 50 cm / min.

Based on strength and elongation, toughness is calculated by the following formula, and 4.4 or more is desirable.
Toughness = strength (cN / dtex) × (elongation (%)) ^1/2
F. U%
Using a USTER TESTER III manufactured by Zellweger Uster, 8 samples were measured with a sample length of 300 m, a measurement yarn speed of 100 m / min, and a setting of 12.5% HI. Note that the value of U% is a value of 1/2 inert and is preferably less than 1.0.
G. Spinning property The number of spun yarn breakage at the stage where 2 tons of fibers were collected was calculated as (times / ton). Needless to say, the smaller the number of yarn breaks, the better.
H. Production of cellulose fatty acid mixed ester chip 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 was filtered off, subsequently washed with water, and dried at 60 ° C. for 4 hours. As a result, the average substitution degrees of acetyl group and propionyl group of the obtained cellulose acetate propionate were 1.9 and 0.7, respectively, and the weight average molecular weight (Mw) was 178,000.

82% by weight of cellulose acetate propionate obtained, 17.9% by weight of polyethylene glycol (PEG 600) having an average molecular weight of 600 and bis (2,6-di-t-butyl-4-methylphenyl) as a phosphorus-based antioxidant Pentaerythritol diphosphite 0.1% by weight was kneaded at 230 ° C. using a biaxial extruder, and cut to about 5 mm to obtain a cellulose fatty acid mixed ester chip. The resulting chip had a melting point of 213 ° C. and a weight average molecular weight (Mw) of 16,000,000.
Examples 1-5
The cellulose fatty acid mixed ester chip obtained in the item H is dried until the moisture content becomes 500 ppm by weight or less, and then melted at 260 ° C., using an apparatus having the configuration shown in FIG. Per second, the horizontal distance (C) between the outermost periphery of the fiber yarn discharged from the spinneret and the upper end of the cooling air blowing portion is 20 mm, the discharge surface of the spinneret and the cooling air blowing portion of the annular cooling device Under the condition that the vertical distance Hq from the upper end is 30 mm, the cooling device, the cooling length Lq, and the temperatures Tt and Td of the upper and lower cooling winds are made different, and the spinning speed is 2500 m / min, and 100 dtex, 72 A cellulose fatty acid mixed ester fiber having a round cross-section of the filament was obtained. The obtained fibers were evaluated for toughness, U%, and yarn-making property. The results are shown in Table 1.
Comparative Example 1
Using a cross-flow cooling device, a heater 13 is provided immediately below the cooling device and the melt spinning device (dotted line frame portion in FIG. 3), and the discharge surface of the spinneret and the cooling air blow-off portion at the annular cooling device The vertical distance Hu from the upper end of the steel is 60 mm, the cooling length Lu is 1000 mm, the upper and lower cooling air temperatures Tt and Td are 38 ° C. and 20 ° C., the die surface temperature is 253 ° C., and the spinning speed is 2000 m / min. By taking-up, a cellulose fatty acid mixed ester fiber having 100 dtex and 72 filaments was obtained. The obtained fibers were evaluated for toughness, U%, and yarn-making property. The results are shown in Table 1.
Comparative Example 2
Using an annular cooling device, a spinning speed of 2500 m / min under the same conditions as in the above example except that the cooling length Lq was 90 mm, the upper temperature Tt was 120 ° C., the lower temperature Td was 50 ° C., and the base surface temperature Ts was 220 ° C. It was taken up in minutes to obtain a 100-dtex, 72-filament cellulose fatty acid mixed ester fiber. The obtained fibers were evaluated for toughness, U%, and yarn-making property. The results are shown in Table 1.
Examples 6-9
The cellulose fatty acid mixed ester chip obtained in the item H is dried until the moisture content becomes 500 ppm by weight or less, and then melted at 260 ° C., the cooling length Lq is 300 mm in the annular cooling device, and the upper cooling air temperature Tt. 250 ° C., lower cooling air temperature Td of 30 ° C., cooling air of 0.8 m / second, and the horizontal distance (C) between the outermost periphery of the fiber yarn discharged from the spinneret and the upper end of the cooling air outlet is 12 .5 mm, the vertical distance Hq between the discharge surface of the spinneret and the upper end of the cooling air blowing part in the annular cooling device is 80 mm, and the spinning speed is 1500 m / min. Differentiated 100 dtex cellulose fatty acid mixed ester fibers were obtained. The obtained fibers were evaluated for toughness, U%, and yarn-making property. The results are shown in Table 2.
Examples 10-14
The cellulose fatty acid mixed ester chip obtained in the item H is dried until the moisture content becomes 500 ppm by weight or less, and then melted at 260 ° C., the cooling length Lq is 300 mm in the annular cooling device, and the upper cooling air temperature Tt. 250 ° C., lower cooling air temperature Td 30 ° C., cooling air 0.1 m / s, horizontal distance (C) between the outermost periphery of the fiber yarn discharged from the spinneret and the upper end of the cooling air blowing portion is 5 mm. The cross-sectional shape of the 100 dtex36 filament is Y-type cellulose by changing the spinning speed under the condition that the vertical distance Hq between the discharge surface of the spinneret and the upper end of the cooling air blowing part in the annular cooling device is 20 mm. A fatty acid mixed ester fiber was obtained. The obtained fibers were evaluated for toughness, U%, and yarn-making property. The results are shown in Table 3.

As is apparent from the results in Table 1, the melt spinning winding method and melt spinning winding device of the cellulose fatty acid mixed ester fiber yarn of the present invention are compared with the conventional melt spinning winding method and melt spinning winding device. Thus, it is possible to stably produce a yarn having significantly improved yarn properties such as high elongation and U%, and it can be said that it exhibits extremely remarkable effects. As in Comparative Example 1, when the cooling air was not blown out from the annular direction and the cross flow was used, the uniformity and the yarn forming property were inferior. Further, even when the annular cooling device was used, when the upper cooling air temperature and the lower cooling air temperature were both lower than the range defined in the present invention, the toughness and the yarn forming property were inferior. On the other hand, when the cooling length, the upper cooling air temperature, and the lower cooling air temperature were set to the particularly preferable ranges among the ranges defined in the present invention, a fiber having particularly excellent uniformity and yarn forming property and excellent toughness was obtained.

  As is clear from the results in Table 2, the present invention has an effect regardless of the cross-sectional shape of the fiber.

  As is apparent from the results in Table 3, the method of the present invention can be applied over a wide range of spinning speeds.

It is a schematic process drawing which shows one embodiment of the cellulose fatty acid mixed ester multifilament melt spinning winding method of the present invention. (A), (b) is the schematic which shows one embodiment which shows the blowing gradient of the cooling air of the annular cooling device of this invention. It is a schematic process drawing which shows one embodiment of the conventional cellulose fatty acid mixed ester multifilament melt spinning winding method.

Explanation of symbols

1: Spin pack 2: Spinneret 3a: Annular cooling device 3b: Cross flow cooling device 4: Cooling air adjusting device 5: Cooling air blowing unit 6: Heating device 7: Lubrication guide 8: Interlace nozzle 9, 10: Take-up roller 11 : Winding device 12: Melt spinning device 13: Heater Y: Yarn H: Vertical distance L between the discharge surface of the spinneret and the upper end of the cooling air blow-off portion in the annular cooling device Lq: Cooling air in the annular cooling device Blowing length Hu of blow-out part: Vertical distance between discharge surface of spinneret and upper end of cooling air blowing part in crossflow cooling device Lu: Bending length of cooling air blowing part of crossflow cooling device C: From spinneret Horizontal distance between the outermost periphery of the discharged fiber yarn and the upper end of the cooling air outlet

Claims (6)

When cooling and solidifying the cellulose fatty acid mixed ester fiber yarn mainly composed of the cellulose fatty acid mixed ester discharged from the spinneret, the cooling air is blown out from the annular direction toward the yarn, and the cooling air is blown out. From the cooling air blowing part having the length Lq, the cooling air is blown onto the fiber yarn under the conditions satisfying the following formulas (A), (B) and (C) to cool and solidify the yarn. A method for melt-spinning a cellulose fatty acid mixed ester fiber, which is characterized.
Tm + 10 <= Tt <= Tm + 60 ... Formula (A)
Where Tt: cooling air temperature at the upper end of the cooling air outlet (° C)
Tm: Melting point of cellulose fatty acid mixed ester (° C.)
Td ≦ 40 Formula (B)
Where Td: cooling air temperature at the lower end of the cooling air outlet (° C.)
100 ≦ Lq ≦ 500 ......... Formula (C)
However, Lq: length of cooling air blowing part (mm) The method for melt-spinning a cellulose fatty acid mixed ester fiber according to claim 1, wherein the fiber yarn is discharged under the condition that the discharge surface temperature Ts of the spinneret satisfies the following formula (E).
Tm + 25 ≦ Ts ≦ Tm + 50 (E)
Ts: Spinneret discharge surface temperature (° C)
Tm: Melting point of cellulose fatty acid mixed ester (° C.) The method for melt-spinning a cellulose fatty acid mixed ester fiber according to claim 1 or 2, wherein a distance H between a discharge surface of the spinneret and an upper end surface of the cooling air blowing portion is 10 to 100 mm. In order to cool and solidify the cellulose fatty acid mixed ester fiber yarn mainly composed of the cellulose fatty acid mixed ester discharged from the spinneret, an annular cooling device for blowing cooling air from the annular direction toward the yarn, and a yarn A take-up roller for taking up and a take-up device for taking up the yarn; and the annular cooling device applies to the fiber yarn discharged from the spinneret the cooling air whose flow rate is adjusted by the cooling air amount adjusting device. Cellulose fatty acid mixing having a cooling air blowing part for spraying, and having cooling air temperature control means for raising the cooling air at the upper part of the cooling air blowing part and lowering the cooling air at the lower part of the cooling air blowing part a esters melt-spinning take-up device of the cellulose fatty acid mixed ester fibers mainly containing, blowing length Lq of the cooling air blowing portion of the annular cooling apparatus, the following formula (F) Melt spinning reel device of a cellulose fatty acid mixed ester fibers, characterized in that the foot.
100 ≦ Lq ≦ 500 ......... Formula (F)
However, Lq: length of cooling air blowing part (mm) In order to cool and solidify the cellulose fatty acid mixed ester fiber yarn mainly composed of the cellulose fatty acid mixed ester discharged from the spinneret, an annular cooling device for blowing cooling air from the annular direction toward the yarn, and a yarn A take-up roller for taking up and a take-up device for taking up the yarn; and the annular cooling device applies to the fiber yarn discharged from the spinneret the cooling air whose flow rate is adjusted by the cooling air amount adjusting device. The cooling air blowing portion for spraying is provided, and the cooling air at the upper portion of the cooling air blowing portion is set to a high temperature satisfying the following formula (A) , and the cooling air at the lower portion of the cooling air blowing portion is represented by the following formula (B) A melt spinning and winding device for cellulose fatty acid mixed ester fibers mainly composed of a cellulose fatty acid mixed ester, characterized in that it has cooling air temperature control means for reducing the temperature to satisfy a low temperature.
Tm + 10 <= Tt <= Tm + 60 ... Formula (A)
Where Tt: cooling air temperature at the upper end of the cooling air outlet (° C)
Tm: Melting point of cellulose fatty acid mixed ester (° C.)
Td ≦ 40 Formula (B)
Where Td: cooling air temperature at the lower end of the cooling air outlet (° C.) Cooling air temperature control means for raising the cooling air at the upper part of the cooling air blowing part to a high temperature and lowering the cooling air at the lower part of the cooling air blowing part has the following formula (A 5), and the cooling air at the lower part of the cooling air blowing section is blown from the cooling air temperature control means satisfying the following formula (B). Take-off device.
Tm + 10 <= Tt <= Tm + 60 ... Formula (A)
Where Tt: cooling air temperature at the upper end of the cooling air outlet (° C)
Tm: Melting point of cellulose fatty acid mixed ester (° C.)
Td ≦ 40 Formula (B)
Where Td: cooling air temperature at the lower end of the cooling air outlet (° C.)

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