JP2007332495A - Thick and thin multifilament yarn of cellulose fatty acid-mixed ester and method for producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thick and thin multifilament yarn of cellulose fatty acid-mixed ester, which is capable of giving natural moire woven/knitted fabrics with dry touch feeling. <P>SOLUTION: In the thick and thin multifilament yarn, the yarn fineness variation value (U%) is 5-20%, the thick and thin variation peak value in the fiber axial direction is 20% or less, and the fineness CV% of the single filaments constituting the multifilament is 5-20%. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a cellulose fatty acid mixed ester-based thick multifilament yarn in which a thick fine portion and a fine fine portion are present in the fiber axis direction.

  Cellulose ester fibers such as cellulose acetate and cellulose triacetate fibers have properties such as elegant luster, vivid color development, natural texture that is gentle on the skin, and moderate moisture absorption. It is positioned as a clothing material with high fashionability different from textiles. However, with the diversification and upgrading of consumer needs in recent years, many attempts have been made to impart new functionality to cellulose ester fibers. For example, by adding thick spots in the longitudinal direction of the fibers, What is expressed is mentioned.

  Conventionally, many thick yarns having thick and fine spots (fineness spots) in the longitudinal direction of the fibers have been proposed, mainly polyester and polyamide fibers. Regarding polyester fibers, many methods have been proposed in which unstretched yarns are stretched incompletely under specific conditions as a method for forming thick fibers in the longitudinal direction of the fibers.

  On the other hand, with regard to the thick and thin yarn of cellulose ester fiber, the dry yarn is used to reduce the thick yarn by intermittently and randomly lowering the take-up speed (250 to 500 m / min) after take-off after specific discharge under specific conditions. An obtaining method has been proposed (see Patent Document 1). However, although the fabric using the thick yarn obtained by this method certainly has a dry texture, the effect is still insufficient. Furthermore, the thick yarn has a problem in productivity due to a low take-up speed, and these improvements have been desired.

  Regarding melt spinning of cellulose ester fibers, cellulose fatty acid mixed ester fibers having excellent mechanical properties and small fineness spots and methods for producing the same have been proposed. (Refer to Patent Document 2) In this document, a fiber having a fineness variation value (U%) of 3.2% is exemplified, but when a fabric was created using this fiber, A dry texture was hardly manifested, and only a plain color with no tone was obtained.

Thus, it has not been achieved so far to obtain a cellulose fatty acid mixed ester thick multifilament yarn having a dry texture and a natural tone due to thick fine spots with good productivity and yarn production.
JP 2001-32128 A (pages 1 to 4) Japanese Patent Laying-Open No. 2004-212278 (page 16)

  The object of the present invention is to solve the above-mentioned problems of the prior art, and when a woven or knitted fabric is obtained, a cellulose fatty acid mixed ester-based thick multifilament yarn having a dry texture and a natural tone due to thick spots is obtained. Is to provide.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have made cellulose under a specific melt spinning condition, and thereby cellulose having a fineness portion and a fineness portion in the fiber axis direction. The present invention has been completed by successfully obtaining a fatty acid mixed ester-based thick multifilament yarn.

That is, the present invention employs the following configuration.
[1] A multifilament composed of a composition mainly composed of a cellulose fatty acid mixed ester, wherein there are a thick portion and a fine portion in the fiber axis direction of the multifilament, and the following formulas (1) to (3) Cellulose fatty acid mixed ester-based thick multifilament yarns.

  (1) The fineness variation value (U%) is 5 to 20%.

  (2) The fiber thickness variation peak value in the fiber axis direction is 20% or less.

(3) The fineness CV% of the single yarn constituting the multifilament is 5 to 15%.
[2] The cellulose fatty acid mixed ester-based thick multifilament according to the above [1], wherein the number of thickness variation peaks of 5% or more in the fiber axis direction of the multifilament is 1 to 50 per 10 m yarn.
[3] The cellulose fatty acid mixed ester-based thick multifilament yarn according to the above [1] or [2], wherein the cellulose fatty acid mixed ester is cellulose acetate propionate or cellulose acetate butyrate.
[4] A cellulose fatty acid mixed ester-based thick multifilament yarn characterized by using conditions satisfying the following formulas (1) to (3) when melt spinning a composition mainly composed of a cellulose fatty acid mixed ester: Production method (1) The back pressure of the spinneret is 4 MPa or less.
(2) The relationship between the yarn speed (Vc) and the spinning speed (Vs) at the cooling start point satisfies the following formula.

(Vc / Vs) × 100 ≧ 85
(3) The distance from the spinneret surface to the cooling start point is 5 to 50 cm.
[5] A woven or knitted fabric comprising 50% by weight or more of the cellulose fatty acid mixed ester thick multifilament yarn according to any one of the above [1] to [3] in the woven or knitted fabric.

  According to the present invention, by employing specific melt spinning conditions, a cellulose fatty acid mixed ester-based thick multifilament yarn having a thick portion and a fine portion in the fiber axis direction can be obtained. By using the thick yarn, a woven or knitted fabric having a dry texture and a natural tone can be obtained.

  Hereinafter, the cellulose fatty acid mixed ester type thick multifilament yarn of the present invention will be described in detail.

  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 include 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 butyryl group are bonded. In this case, the average substitution degree of the acetyl group and the acyl group (propionyl group or butyryl group) preferably satisfies the following formula. The average degree of substitution refers to the number of chemically bonded acyl groups among the three hydroxyl groups present per glucose unit of cellulose.

2.0 ≦ (average degree of substitution of acetyl group + average degree of substitution of acyl group) ≦ 3.0
1.5 ≦ (average degree of substitution of acetyl group) ≦ 2.5
0.5 ≦ (Average substitution degree of acyl group) ≦ 1.5
A cellulose fatty acid mixed ester satisfying the above formula is preferable because it has a high heat softening temperature, moderate hygroscopicity, and good dimensional stability when it is made into a woven or knitted fabric.

  The weight average molecular weight (Mw) of the cellulose fatty acid mixed ester is preferably 50,000 to 255,000. When Mw is less than 50,000, the thermal decomposition during melt spinning becomes significant, and the mechanical properties (particularly tensile strength) of the fiber obtained by melt spinning decrease, so that the practical level is reached. Otherwise, the melt viscosity becomes very low, and the fineness CV% of the obtained single yarn is greatly deteriorated. On the other hand, if Mw exceeds 2550,000, the melt viscosity becomes very high, so that stable fiberization by melt spinning cannot be performed, and the strength and elongation characteristics of the obtained fiber are deteriorated. From the viewpoint of good mechanical properties and stable melt spinnability, Mw is more preferably 60,000 to 20,000, and even more preferably 80,000 to 20,000,000. In addition, a weight average molecular weight (Mw) means the value computed by GPC measurement, and demonstrates in detail in an Example.

  The composition containing the cellulose fatty acid mixed ester as the main component in the present invention may contain a plasticizer, and the plasticizer is preferably a polyhydric alcohol compound. Specifically, polyalkylene glycols, glycerin compounds, caprolactone compounds, etc., which have good compatibility with cellulose fatty acid mixed esters and have a remarkable thermoplastic effect that can be melt-spun, are polyalkylene glycols. Is preferred. Specific examples of the polyalkylene glycol include, but are not limited to, polyethylene glycol, polypropylene glycol, polybutylene glycol and the like having a weight average molecular weight of 200 to 4000, and these may be used alone or in combination. Can do.

  The plasticizer content is preferably 5 to 25% by weight. By making the content of the plasticizer 5 to 25% by weight, the heat flow property of the cellulose fatty acid mixed ester is improved, so that production by a melt spinning method with high production efficiency is possible, and the fiber cross section is precisely and arbitrarily specified. It can be controlled and the resulting fiber properties are also good. The plasticizer content is more preferably 8 to 22% by weight, and most preferably 10 to 20% by weight.

  The composition containing the cellulose fatty acid mixed ester as a main component in the present invention preferably contains a phosphorus-based antioxidant, and a pentaerythritol-based compound is particularly preferable. When a phosphorus-based antioxidant is contained, the thermal decomposition prevention effect is very remarkable even in the high spinning temperature range and the low discharge region, the deterioration of the mechanical properties of the fiber is suppressed, and the color tone of the resulting fiber Will be better. It is preferable that the compounding quantity of phosphorus antioxidant is 0.005 weight%-0.500 weight% with respect to a composition.

  The cellulose fatty acid mixed ester-based thick multifilament yarn of the present invention has a thick fineness portion and a fine fineness portion in the fiber axis direction, and has a specific fineness variation value (U%) and a specific thickness variation peak. Value and the fineness CV% of the single yarn constituting the multifilament.

  The fineness variation value (U%) of the cellulose fatty acid mixed ester type thick multifilament yarn of the present invention is 5 to 20%. The fineness variation value (U%: Normal mode) is an index of thickness unevenness (fineness unevenness) in the longitudinal direction of the fiber, and can be obtained by a Worcester tester manufactured by Zerbegger Worcester. The measurement conditions for the fineness variation value will be described in detail in Examples.

  By setting the fineness variation value (U%) to 5% or more, the appearance when dyed is not uniform, but has a natural tone. Further, the surface of the woven or knitted fabric has a slight unevenness, and a dry feeling is developed. On the other hand, by setting the fineness variation value (U%) to 20% or less, the shade difference is not emphasized when dyeing, so that a natural appearance can be maintained. Further, since the fluff and sagging do not occur in the multifilament, the passability of the high-order processing step does not deteriorate. Furthermore, the surface condition (quality) of the woven or knitted fabric does not deteriorate. The fineness variation value (U%) is more preferably 6 to 18%, and further preferably 7 to 15%.

  The thickness variation peak value in the fiber axis direction of the cellulose fatty acid mixed ester-based thick multifilament yarn of the present invention is 20% or less. The thickness variation peak value in the fiber axis direction is a maximum peak value of a waveform obtained by measurement of a fineness variation value (U%: Normal mode).

  By setting the thickness variation peak value to 20% or less, the variation in the fineness variation value between products does not become too large. For example, streaks such as vertical stripes do not occur, and the feeling of wrinkle is great even when used for wefts. It is possible to stably obtain a woven or knitted fabric having the same appearance without variation. The thickness variation peak value is more preferably 18% or less, and further preferably 15% or less.

  The number of thickness variation peaks of 5% or more in the fiber axis direction of the cellulose fatty acid mixed ester-based thick multifilament yarn of the present invention is 1-50 per 10 m. The number of thickness fluctuation peaks is a value obtained by drawing a line with an average thickness of 5% on a chart obtained by measuring the fineness fluctuation value and reading the number of peak tops existing above this line.

  By setting the number of thickness variation peaks to 1 or more per 10 m, a woven or knitted fabric having a dry feeling can be obtained. Further, by setting the number of thickness variation peaks to 50 or less per 10 m, the thick portion does not increase excessively, so that the resulting woven or knitted fabric has an effective contrast. The number of thickness variation peaks of 5% or more is more preferably 3 to 45, more preferably 5 to 40 per 10 m.

  The fineness CV% of the single yarn constituting the cellulose fatty acid mixed ester type thick multifilament yarn of the present invention is 5 to 15%. The fineness CV% of the single yarn is an index of the diameter unevenness of the constituent fibers in the cross-sectional direction of the multifilament. When the fineness CV% of the single yarn is large, a filament having a fineness finer than an average fineness and a filament having a fineness are present. It will be.

  When the knitted fabric is made by setting the fineness CV% of the single yarn to 5% or more, the appearance has a natural tone, and the dry feeling intended by the present invention is exhibited.

  By setting the fineness CV% of the single yarn to 15% or less, when processing into a woven or knitted fabric, there is a problem that the filament portion finer than the average fineness is likely to break and become fluffy, and the filament having a fineness larger than the average fineness When this is dyed, it is possible to prevent problems such as dark staining and strong streaks. The fineness CV% of the single yarn is more preferably 6 to 14%, and further preferably 7 to 13%. The fineness CV% of the single yarn refers to a value obtained by calculating the fineness of the single yarn constituting the multifilament according to the following equation.

Single yarn fineness CV% = (σ / X) × 100
However, X is the average value of the single yarn fineness which comprises a multifilament, and (sigma) is a standard deviation.

  The tensile strength of the cellulose fatty acid mixed ester type thick multifilament yarn in the present invention is preferably 0.9 cN / dtex or more. If the tensile strength is 0.9 cN / dtex or more, it is preferable because it is easy to pass through high-order processing steps such as weaving and knitting, and the strength of the final product is not insufficient. From the viewpoint of good tensile strength characteristics, the higher the tensile strength, the more the practical range is widened and it can be developed for various uses, but at present, the upper limit is about 2.0 cN / dtex. The tensile strength is more preferably 1.0 cN / dtex or more, and further preferably 1.1 cN / dtex or more.

  The elongation of the cellulose fatty acid mixed ester-based thick multifilament yarn in the present invention is preferably 15 to 50%. When the elongation is 15% or more, fluff does not occur in the spinning process, and fluff and yarn breakage do not occur frequently in the high-order processing process such as weaving or knitting. The passability of is improved. The elongation is preferably 50% or less. When the elongation is 50% or less, the fiber will not be deformed if the stress is low, and a dyeing defect of the final product due to wetting marks during weaving will not occur. The elongation is more preferably 18% to 45%, further preferably 20 to 40%.

  The fineness of the single yarn constituting the cellulose fatty acid mixed ester-based thick multifilament yarn in the present invention is preferably 0.5 dtex to 30.0 dtex. By setting the single yarn fineness to 0.5 dtex to 30.0 dtex, fibers can be obtained with good spinning properties by the melt spinning method, and softness is required due to the appropriate bending rigidity of the fiber structure. It can also be applied to knitted fabrics. The single yarn fineness is more preferably 1.0 dtex to 20 dtex, still more preferably 1.5 dtex to 10.0 dtex.

  The single yarn cross-sectional shape of the cellulose fatty acid mixed ester-based thick multifilament yarn in the present invention is not particularly limited, and for example, a normal circular cross-section, a polygonal cross-section such as a triangle or a quadrangle, a flat cross-section, etc. are adopted. Can do. Further, it may be a cross-section mixed multifilament yarn in which two or more types of cross-sections are mixed.

  In the present invention, after melt-molding a composition mainly composed of cellulose fatty acid mixed ester, it is contained in cellulose fatty acid mixed ester thick multifilament yarn by chemical treatment using water treatment such as warm water or hot water or organic solvent. The plasticizer that has been used may be eluted. The plasticizer content contained in the cellulose fatty acid mixed ester thick multifilament yarn in the final product is preferably 0 to 25% by weight. When the content of the plasticizer is within this range, the strength of the final product is not deficient, the product durability is improved, and the heat softening temperature is also increased, thereby improving the handleability of the product.

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

  Next, a method for producing the cellulose fatty acid mixed ester type thick multifilament yarn of the present invention will be described.

  FIG. 1 is a view showing an embodiment of an apparatus used for the method for producing a cellulose fatty acid mixed ester type thick multifilament yarn of the present invention. In FIG. 1, 1 is a spin block, 2 is a melt spinning pack, 3 is a spinneret, 4 is a cooling start point, 5 is a cooling device, 6 is a spun yarn, 7 is an oil supply device, and 8 is a first godet roller. , 9 is a second godet roller, and 10 is a winding yarn. L is the distance between the spinneret surface and the cooling start point.

  The composition containing the molten cellulose fatty acid mixed ester as a main component is extruded from the discharge hole of the spinneret 3 attached to the lower part of the melt spinning pack 2 attached to the spin block 1. The extruded spun yarn 6 is cooled to the room temperature by the cooling device 5 from the cooling start point 4, the finishing agent is applied by the oil supply device 7, and the first godet roller 8 and the second godet rotating at a predetermined speed. It is wound up by a winder through a dead roller 9. In addition, you may install apparatuses, such as a heating cylinder and a heat retention cylinder, between the spin block 1 and the cooling device 5. FIG.

In order to obtain the cellulose fatty acid mixed ester-based thick multifilament yarn of the present invention, it is important to satisfy the following formulas (1) to (3) when melt spinning the composition mainly composed of the cellulose fatty acid mixed ester. It is.
(1) The back pressure of the spinneret is 4 MPa or less.
(2) The relationship between the yarn speed (Vc) and the spinning speed (Vs) at the cooling start point satisfies the following formula.

(Vc / Vs) × 100 ≧ 85
(3) The distance from the spinneret surface to the cooling start point is 5 to 50 cm.

  In the present invention, it is important that the back pressure of the spinneret is 4.0 MPa or less. In the case of melt spinning a composition mainly composed of cellulose fatty acid mixed ester, the relationship between the back pressure of the spinneret and the fineness CV% of the single yarn has been intensively studied, and the back pressure of the spinneret is controlled to 4.0 MPa or less. Thus, it was found that the variation in the single yarn fineness constituting the multifilament was increased, and the single yarn fineness CV%, which is an essential requirement of the present invention, was 5% or more. Since the back pressure of the spinneret is related to the hole diameter and / or hole depth of the spinneret and the melt viscosity of the composition, it can be arbitrarily selected within a desired range.

  The back pressure of the spinneret surface is more preferably 3.8 MPa or less, and still more preferably 3.6 MPa or less. In order to obtain the cellulose fatty acid mixed ester-based thick multifilament yarn of the present invention with good operability by the melt spinning method, the back pressure of the spinneret is preferably 1.0 MPa or more. The back pressure of the spinneret means a pressure increase range that is increased immediately before a polymer starts to be discharged from the spinneret when a melt spinning pack preheated at the same temperature as the spinning temperature is attached to the spin block.

  In the present invention, the relationship between the yarn speed (Vc) and the spinning speed (Vs) at the cooling start point satisfies the following formula.

(Vc / Vs) × 100 ≧ 85
The cooling start point here refers to the uppermost end point of the blowing portion of the cooling air blown from the cooling device, and the spinning speed refers to the speed of the first godet roller.

  In the fiber excellent in uniformity of thickness unevenness in the fiber longitudinal direction, the final yarn diameter of the fiber wound by the winder is not reached even at the cooling start point, and the value in the above formula is 85. Is less than. In this case, only fibers with a fineness variation value of less than 5% can be obtained, and the woven or knitted fabric produced using the fibers has a very flat (solid color) and has the natural tone that is the object of the present invention. It must not be a dry texture.

  The composition used for melt spinning in the present invention has a very high temperature dependency of elongational viscosity as compared with thermoplastic polymers such as polyester and polyamide. That is, the composition discharged from the spinneret rapidly solidifies. After paying attention to this characteristic, as a result of intensive studies on the yarn speed at the cooling start point of the spun yarn discharged from the spinneret, it is important for achieving the present invention that the above formula is 85 or more. I found out.

  That is, by setting it to 85 or more, the final yarn diameter becomes close to the wound yarn before the spun yarn is uniformly cooled by the cooling air blown from the cooling device. In this case, the yarn diameter is close to the diameter of the wound yarn before the yarn is forcibly cooled uniformly by the cooling device, but in the space from the spinneret to the cooling start point, Since airflow (cold air) or the like flowing into the space enters and is in a turbulent state, uniform cooling of the single yarn constituting the multifilament becomes impossible. Accordingly, the obtained fiber has random thickness spots in the longitudinal direction of the fiber, and the specific fineness variation value (U%) and the peak thickness variation peak in the specific fiber axis direction, which are essential requirements in the present invention. It is possible to satisfy the value and the number of thickness variation peaks.

  The distance from the spinneret surface to the cooling start point is 5 to 50 cm. When the distance from the spinneret surface to the cooling start point is less than 5 cm, the spun yarn discharged from the spinneret is uniformly cooled by the cooling air, so the obtained cellulose fatty acid mixed ester thick multifilament yarn is It will become the thing excellent in the uniformity without a thickness spot in a fiber longitudinal direction. Therefore, it is not possible to obtain a cellulose fatty acid mixed ester thick multifilament yarn having a specific fineness variation value (U%), which is an essential requirement of the present invention, and having random thickness unevenness in the fiber longitudinal direction. By setting the distance between the spinneret surface and the cooling start point to 50 cm or less, an unstable melting region of the spun yarn discharged from the spinneret can be avoided, so that trouble such as yarn breakage does not occur and the yarn is produced. Operability is improved. The distance between the spinneret surface and the cooling start point is more preferably 8 to 48 cm, and still more preferably 10 to 45 cm. In the present invention, in order to adjust the distance from the spinneret surface to the cooling start point within the above range, a heating cylinder, a heat insulating cylinder, or the like may be installed between the spin block and the cooling device.

  When fiberizing a composition containing a cellulose fatty acid mixed ester as a main component by melt spinning, the spinning temperature is preferably 220 ° C to 280 ° C. By setting the spinning temperature to 220 ° C. or higher, the elongation viscosity of the yarn discharged from the spinneret is sufficiently lowered, so that the fiber microstructure of the yarn discharged from the spinneret is sufficiently developed, and the fiber mechanical Good characteristics. Furthermore, the yarn maneuverability is stabilized. Moreover, since the thermal decomposition of the thermoplastic composition can be suppressed by setting the spinning temperature to 280 ° C. or lower, it is possible to suppress poor mechanical properties due to a decrease in the molecular weight of the resulting fiber and deterioration of quality due to coloring. The spinning temperature is more preferably 230 to 270 ° C, and further preferably 240 to 260 ° C.

  The spinning speed is preferably 1000 to 4000 m / min. By setting the spinning speed to 100 to 4000 m / min, a spinning stress that sufficiently promotes the molecular orientation of the obtained fiber is applied to the spun yarn, and a fiber having excellent fiber characteristics can be obtained with good spinning maneuverability. . In addition, since the deformation of the yarn discharged from the spinneret proceeds rapidly, the obtained fiber tends to have thick spots. The spinning speed is more preferably 1200 to 3500 m / min, and further preferably 1500 to 3000 m / min.

  As described above, the cellulose fatty acid mixed ester-based thick multifilament yarn obtained in the present invention has a thick portion and a fine portion in the fiber axis direction. The woven or knitted fabric referred to in the present invention requires that the cellulose fatty acid mixed ester-based thick multifilament yarn of the present invention is used in an amount of 50% by weight or more in the woven or knitted fabric. By setting it to 50% by weight or more, it becomes possible to obtain a woven or knitted fabric having a dry texture and a natural tone due to fine spots.

  The woven or knitted fabric referred to in the present invention can take the form of a woven fabric or a knitted fabric, and fibers other than cellulose fatty acid mixed ester-based thick multifilament yarn, such as polylactic acid, polyglycolic acid, polyhydroxybutyrate, and polybutylene. Biodegradable fibers such as succinate and polycaprolactone, natural fibers such as cotton, silk, hemp, and wool, recycled fibers and chemical fibers such as rayon and acetate, polyethylene terephthalate, polypropylene terephthalate, polybutylene terephthalate, nylon, acrylic, A mixed article with synthetic fibers such as vinylon, polyolefin, and polyurethane may be used.

  When used as a woven or knitted fabric, there are no restrictions on the woven or knitted structure. In the case of a woven fabric, a plain structure, an oblique structure, a satin structure, and their applied structures, and in the case of a knitted fabric, a flat knitting (Tenji knitting) Ordinary woven and knitted structures such as rib knitted (rubber knitted), double-sided knitted, pearl knitted weft knitted structures, and denby knitted, atlas knitted, cord knitted and other knitted knitted structures can be used. There are no restrictions on the application.

  As a method for knitting or weaving the knitted or knitted fabric, a known method can be used. Specifically, weaving machines such as shuttles, rapiers, air jet looms and water jet looms, and knitting machines such as flat knitting machines, circular knitting machines and warp knitting machines can be arbitrarily used according to the purpose. Moreover, it can also be set as a composite woven / knitted fabric using another fiber. In that case, it can be arbitrarily performed with other fibers such as knitting, knitting, knitting, and blending.

  Hereinafter, the present invention will be described in more detail with reference to examples. In addition, each characteristic value in an Example is calculated | required with the following method. The present invention is not limited to these examples.

A. Average substitution degree of cellulose fatty acid mixed ester The calculation method of the average substitution degree of cellulose fatty acid mixed ester in which acetyl group and acyl group are bonded to cellulose is as follows.

  0.9 g of 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 Weight average molecular weight (Mw) measurement by GPC It was completely dissolved in tetrahydrofuran so that the concentration of the cellulose fatty acid mixed ester was 0.15% by weight, and used as a sample for GPC measurement. Using this sample, GPC measurement was performed with Waters 2690 under the following conditions, and the weight average molecular weight (Mw) was determined in terms of polystyrene.

Column: Two Tosoh TSK gel GMHHR-H connected Detector: Waters2410 Differential refractometer RI
Moving bed solvent: Tetrahydrofuran Flow rate: 1.0 ml / min Injection volume: 200 μl
C. Yarn speed at the cooling start point The yarn speed at the cooling start point was measured using LDV (MODEL LS50 PROCESSOR) manufactured by TSI. Sampling in the measurement of the yarn speed was performed 500 times, and the average value was defined as the yarn speed (m / min).

D. Back pressure of the spinneret A melt spin pack preheated at the same temperature as the spinning temperature was attached to the spin block, and the pressure range increased when the polymer started to be discharged from the spinneret was defined as the back pressure of the spinneret.

E. Fineness fluctuation value (U%: Normal mode)
The U% measurement was obtained by measuring 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: 50 m / min Measurement time: 2.5 minutes Measurement fiber length: 100 m
Twister: 3000m ^-1 , S
F. Thickness variation peak value in the fiber axis direction The maximum peak value of the waveform obtained by measuring the fineness variation value (U%: Normal mode) was read, and the value was taken as the thickness variation peak value in the fiber axis direction. The maximum peak value is a value in a fiber length of 100 m where the fineness variation value measurement was performed.
G. The number of thickness variation peaks of 5% or more in the fiber axis direction A line is drawn to the value of 5% average thickness on the chart obtained by measurement of the fineness variation value (U%: Normal mode), and exists beyond this line. The number of peak tops was defined as the number of thickness variation peaks of 5% or more in the fiber axis direction. The number of peaks was a value obtained by analyzing a measurement length of 5 m on a chart obtained by measuring the fineness variation value and dividing the number read by the measurement length.

H. Tensile strength and elongation Under an environment of temperature 20 ° C. and humidity 65%, Shimadzu Autograph AG-50NISMS type was used and a tensile test was performed under the conditions of a sample length of 20 cm and a tensile speed of 20 cm / min. The value obtained by dividing the stress (cN) at the indicated point by the fineness (dtex) was taken as the tensile strength (cN / dtex). The elongation at that time was defined as elongation (%). The number of measurements was 10 times, and the average values were taken as tensile strength and elongation.

I. Fine yarn CV%
Cellulose fatty acid mixed ester type thick multifilament yarn is cut perpendicular to the fiber axis direction, the cut surface is photographed with an optical microscope, and the single yarn diameter of each single yarn constituting the multifilament is determined from the obtained image. The fineness of each single yarn was calculated from the measured value, and the single yarn fineness CV% was calculated from the following equation.

Single yarn fineness CV% = (σ / X) × 100
However, X is the average value of the single yarn fineness which comprises a multifilament, and (sigma) is a standard deviation.

J. et al. Spinning operability evaluation Spinning was performed continuously for 6 hours, and evaluated according to the following criteria.

A: Number of times of yarn breakage is 0 to 1 (very good yarn maneuverability)
○: Number of times of yarn breakage is 2 to 3 times (good yarn operability)
X: Number of times of yarn breakage is 4 times or more (the yarn operability is poor).

K. Evaluation of feeling of sensation Fabrication was made using cellulose fatty acid ester mixed thick multifilament yarn, and the woven fabric was evaluated according to the following criteria, and ◎ and ○ were passed ◎: Natural feeling of sensation was very good O: The natural sensation effect is well expressed. X: The sensation effect is insufficient (the natural appearance is impaired or the appearance is plain).

L. Evaluation of texture Fabrics were prepared using cellulose-fatty acid mixed ester-based thick multifilament yarns, sensory evaluation was carried out by 10 panelists on the fabrics, and the following criteria were evaluated. ◎ and ○ were accepted.

  Did you feel that there was a significant difference in dryness when grasping the fabric compared to conventional products?

A: Nine or more persons are determined to have a significant difference. O: Seven to eight persons are determined to have a significant difference. X: Five persons or less are determined to have a significant difference.

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 was filtered off, subsequently washed with water, and dried at 60 ° C. for 4 hours. The average substitution degree of the acetyl group and propionyl group of the obtained cellulose acetate propionate was 1.9 and 0.7, respectively, and the weight average molecular weight (Mw) was 178,000.

Example 1
82% by weight of cellulose acetate propionate prepared in Synthesis Example 1, 17.9% by weight of polyethylene glycol (PEG 600: manufactured by Sanyo Chemical Co., Ltd.) having an average molecular weight of 600, and bis (2,6-di-t) as a phosphorus-based antioxidant -Butyl-4-methylphenyl) pentaerythritol diphosphite (manufactured by Asahi Denka Co., Ltd.) 0.1 wt% using a biaxial extruder at 240 ° C., cutting to about 5 mm, and a cellulose fatty acid mixed ester composition A pellet (Mw 150,000) was obtained.

  The pellets were vacuum dried at 80 ° C. for 10 hours, melted at a melter temperature of 260 ° C., introduced into a melt spinning pack having a spinning temperature of 260 ° C., and discharged at a discharge rate of 20.0 g / min. Spinneret specifications: hole diameter 0.18 mm, hole length 0.54 mm) were spun from a spinneret having 36 holes (spinner back pressure 3.1 MPa).

  The spun yarn is cooled by cooling air (20 ° C.) at a wind speed of 35 m / min from a distance of 20.5 cm below the spinneret surface (yarn speed 1701 m / min at the cooling start point), and an oil agent is applied. After converging, it is taken up by the first godet roller rotating at 2000 m / min, and the winding tension is 0.1 cN / dtex via the second godet roller rotating at the same speed as the first godet roller. It wound up with the winder which rotates at the speed which becomes. The resulting fiber (100 dtex-36 filament) had the properties listed in Table 1.

  Further, when continuous spinning was carried out, the yarn breakage was one time, and the spinning operability was very good.

  This fiber was used for warp and weft to form a satin woven fabric of 5 satin in an air jet loom. The satin fabric was washed with water at 60 ° C. for 5 minutes to remove the plasticizer, and further scoured to remove dirt such as oil. Furthermore, after performing an intermediate set at 160 ° C., dyeing was carried out by a conventional method in a PH5 using a liquid dyeing machine (Cibacet Scallet EL-F2G 0.5% owf (manufactured by Ciba Specialty Chemicals Co., Ltd.)). ). After dyeing, RC washing was performed under the following conditions.

Sodium carbonate 1g / l
Hydrosulfite 2g / l
Softanol EP12030 (manufactured by Nippon Shokubai Co., Ltd.) 0.2g / l
Further, after drying, a finishing set at 150 ° C. was performed.

  When the sensory evaluation of this fabric was carried out, the natural sensation effect was expressed very well, and it was of high quality with a very dry texture.

Example 2
The same pellets as in Example 1 were vacuum dried at 80 ° C. for 10 hours, melted at a melter temperature of 260 ° C., and introduced into a melt spinning pack having a spinning temperature of 260 ° C., and a discharge amount of 40.5 g / min. Spinning was performed from a spinneret having 48 holes (spinneret spec: hole diameter 0.2 mm, hole length 0.8 mm) under conditions (spinner back pressure 4.0 MPa).

  The spun yarn passes through a heating cylinder (40 cm: set temperature 260 ° C.) installed immediately below the spin block, and then from a distance of 49.5 cm below the spinneret surface (yarn speed 2760 m / min at the cooling start point). After cooling with cooling air (25 ° C.) at a wind speed of 40 m / min, applying an oil agent and converging, it is taken up by a first godet roller rotating at 3000 m / min and at the same speed as the first godet roller. It wound up with the winder which rotates at the speed | rate from which the winding tension | tensile_strength becomes 0.1 cN / dtex through the rotating 2nd godet roller. The resulting fiber (135 dtex-48 filament) had the properties listed in Table 1.

  Further, when continuous spinning was carried out, the yarn breakage was 3 times, and the spinning operability was good.

  Using this fiber, a woven fabric was prepared in the same manner as in Example 1 and sensory evaluation was performed. As a result, the natural wrinkle effect was well expressed and the fabric had a very dry texture.

Example 3
The same pellets as in Example 1 were vacuum-dried at 80 ° C. for 10 hours, melted at a melter temperature of 260 ° C., and introduced into a melt spinning pack having a spinning temperature of 260 ° C., and a discharge amount of 12.5 g / min. Spinning was carried out from a spinneret having 72 holes (spinneret spec: hole diameter 0.23 mm, hole length 0.6 mm) under conditions (spinner back pressure 1.1 MPa).

  The spun yarn is cooled by a cooling air (25 ° C.) at a wind speed of 30 m / min from a distance of 5 cm below the spinneret surface (yarn speed 1228 m / min at the cooling start point), and an oil agent is applied and converged. After that, the first godet roller that rotates at 1250 m / min is picked up, and the winding tension becomes 0.1 cN / dtex through the second godet roller that rotates at the same speed as the first godet roller. It was wound up with a winder rotating at. The resulting fiber (100 dtex-72 filament) had the properties listed in Table 1.

  Further, when continuous spinning was carried out, the yarn breakage was 3 times, and the spinning operability was good.

  Using this fiber, a woven fabric was prepared in the same manner as in Example 1 and sensory evaluation was conducted. As a result, a natural wrinkle effect was well expressed and a good dry texture was obtained.

Example 4
80% by weight of cellulose acetate propionate prepared in Synthesis Example 1, 19.9% by weight of polyethylene glycol (PEG 600: manufactured by Sanyo Chemical Co., Ltd.) having an average molecular weight of 600, and bis (2,6-di-t) as a phosphorus-based antioxidant -Butyl-4-methylphenyl) pentaerythritol diphosphite (manufactured by Asahi Denka Co., Ltd.) 0.1 wt% using a biaxial extruder at 230 ° C., cutting to about 5 mm, and a cellulose fatty acid mixed ester composition A pellet (Mw 16.1 million) was obtained. The pellets were vacuum dried at 80 ° C. for 10 hours, melted at a melter temperature of 247 ° C., introduced into a melt spinning pack having a spinning temperature of 247 ° C., and discharged at a discharge rate of 15.0 g / min. Spinneret specifications: hole diameter 0.25 mm, hole length 0.625 mm) were spun from a spinneret having 48 holes (spinneret back pressure 1.8 MPa).

  After passing this spinning yarn through a heat insulating cylinder (5.5 cm) installed immediately below the spin block, from a distance of 15.5 cm below the spinneret surface (yarn speed 1799 m / min at the cooling start point), Cooled by cooling air (20 ° C) with a wind speed of 35 m / min, applied with oil, converged, taken up by the first godet roller rotating at 2000 m / min, and rotated at the same speed as the first godet roller Winding was performed with a winder rotating at a speed at which the winding tension was 0.1 cN / dtex via the second godet roller. The resulting fiber (75 dtex-48 filament) had the properties listed in Table 1.

  Further, when continuous spinning was carried out, the yarn breakage was one time, and the spinning operability was very good.

  Using this fiber, a woven fabric was prepared in the same manner as in Example 1 and subjected to sensory evaluation. As a result, a natural feeling of wrinkle was expressed very well, and a high-grade one having an extremely dry texture was also obtained. Met.

Example 5
86% by weight of cellulose acetate propionate prepared in Synthesis Example 1, 13.8% by weight of polyethylene glycol (PEG 600: manufactured by Sanyo Chemical Co., Ltd.) having an average molecular weight of 600, and bis (2,6-di-t) as a phosphorus-based antioxidant -Butyl-4-methylphenyl) pentaerythritol diphosphite (manufactured by Asahi Denka Co., Ltd.) 0.2% by weight using a biaxial extruder at 245 ° C., cutting to about 5 mm, and a cellulose fatty acid mixed ester composition A pellet (Mw 153,000) was obtained. The pellets were vacuum dried at 80 ° C. for 10 hours, melted at a melter temperature of 270 ° C., introduced into a melt spinning pack having a spinning temperature of 270 ° C., and discharged at a discharge rate of 27.5 g / min. Spinneret specifications: hole diameter 0.23 mm, hole length 0.46 mm) were spun from a spinneret having 24 holes (spinner back pressure 2.5 MPa).

  The spun yarn is cooled by cooling air (20 ° C.) at a wind speed of 45 m / min from a distance of 8.0 cm below the spinneret surface (yarn speed 2324 m / min at the cooling start point), and an oil agent is applied. After being converged, it is taken up by a first godet roller that rotates at 2500 m / min, and the winding tension is 0.1 cN / dtex through a second godet roller that rotates at the same speed as the first godet roller. It wound up with the winder which rotates at the speed which becomes. The resulting fiber (110 dtex-24 filament) had the properties listed in Table 1.

  Further, when continuous spinning was carried out, the yarn breakage was 0 times, and the spinning operability was very good.

  Using this fiber as a weft, a plain woven fabric is made using polylactic acid fiber (84 dtex-24 filament) obtained by spinning and drawing by a known method (content of cellulose fatty acid mixed ester type thick multifilament yarn) 53%), plasticizer removal, scouring, dyeing and the like were performed in the same manner as in Example 1.

  When the sensory evaluation of the obtained plain woven fabric was performed, the natural wrinkle effect was very well expressed. Moreover, it had a dry texture.

Synthesis example 2
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, 5 parts by weight of sulfuric acid was added as an esterification catalyst, and the mixture was stirred for 180 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 90 ° 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. The average substitution degree of acetyl group and propionyl group of the obtained cellulose acetate propionate was 1.8 and 0.8, respectively, and the weight average molecular weight (Mw) was 118,000.

Example 6
90% by weight of cellulose acetate propionate produced in Synthesis Example 2 and 10% by weight of polyethylene glycol having an average molecular weight of 1000 (PEG 1000: manufactured by Sanyo Chemical Co., Ltd.) are kneaded at 245 ° C. using a biaxial extruder and cut to about 5 mm. Thus, cellulose fatty acid mixed ester composition pellets (Mw 99,000) were obtained. The pellets were vacuum-dried at 80 ° C. for 10 hours, melted at a melter temperature of 265 ° C., introduced into a melt spinning pack having a spinning temperature of 265 ° C., and discharged at a discharge rate of 20.3 g / min. Spinneret specifications: hole diameter 0.23 mm, hole length 0.30 mm) were spun from a spinneret having 36 holes (spinner back pressure 3.7 MPa).

  The spun yarn is cooled by cooling air (20 ° C.) at a wind speed of 30 m / min from a distance of 10 cm below the spinneret surface (yarn speed 1290 m / min at the cooling start point), and an oil agent is applied to converge. After that, the first godet roller that rotates at 1500 m / min is picked up, and the winding tension becomes 0.09 cN / dtex through the second godet roller that rotates at the same speed as the first godet roller. It was wound up with a winder rotating at. The resulting fiber (135 dtex-36 filament) had the properties listed in Table 1.

  Further, when continuous spinning was carried out, the yarn breakage was 3 times, and the spinning operability was good.

  Using this fiber, a woven fabric was prepared in the same manner as in Example 1 and sensory evaluation was performed. As a result, a natural wrinkle-feeling effect was expressed well, and a high-quality one with a dry texture was obtained. It was.

Synthesis example 3
To 100 parts by weight of cellulose (cotton linter), 100 parts by weight of acetic acid and 200 parts by weight of propionic acid were added and mixed at 50 ° C. for 30 minutes. After the mixture was cooled to room temperature, 150 parts by weight of acetic anhydride cooled in an ice bath and 350 parts by weight of propionic anhydride were added as an esterifying agent, 4 parts by weight of sulfuric acid was added as an esterification catalyst, and the mixture was stirred for 160 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 60 ° C. for 1.5 hours. 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. The average substitution degree of the acetyl group and propionyl group of the obtained cellulose acetate propionate was 1.5 and 0.9, respectively, and the weight average molecular weight (Mw) was 208,000.

Example 7
75% by weight of cellulose acetate propionate produced in Synthesis Example 3 and 25% by weight of polyethylene glycol having an average molecular weight of 400 (PEG 400: manufactured by Sanyo Chemical Co., Ltd.) are kneaded at 210 ° C. using a biaxial extruder and cut to about 5 mm. Thus, cellulose fatty acid mixed ester composition pellets (Mw 19.000,000) were obtained. The pellets were vacuum dried at 80 ° C. for 12 hours, melted at a melter temperature of 230 ° C., introduced into a melt spinning pack having a spinning temperature of 230 ° C., and discharged at a discharge rate of 35.0 g / min. Spinneret specifications: hole diameter 0.3 mm, hole length 0.45 mm) were spun from a spinneret having 12 holes.

  The spun yarn is passed through a cylindrical heat insulating cylinder (15 cm) installed immediately below the spin block, and then the wind speed is measured from a distance of 25 cm below the spinneret surface (yarn speed of 3080 m / min at the cooling start point). Cooled by cooling air (20 ° C.) at 30 m / min, applied with an oil agent, converged, picked up by a first godet roller rotating at 3500 m / min, and rotated at the same speed as the first godet roller It wound up with the winder which rotates at the speed | rate from which a winding tension | tensile_strength becomes 0.09 cN / dtex via the 2nd godet roller. The resulting fiber (100 dtex-12 filament) had the properties listed in Table 1.

  Further, when continuous spinning was carried out, the yarn breakage was 3 times, and the spinning operability was good.

  Using this fiber, a woven fabric was prepared in the same manner as in Example 1 and subjected to sensory evaluation. As a result, a natural feeling of wrinkle was expressed very well, and a high-grade one having an extremely dry texture was also obtained. Met.

Example 8
The fiber (75 dtex-48 filament) obtained in Example 4 was spun by a known method and entangled with polylactic acid (33 dtex-12 filament) obtained by drawing to obtain a blended yarn ( 108 dtex-60 filaments).

  Using this fiber as the warp and the weft as the fiber obtained in Example 4, a plain fabric was prepared (cellulose fatty acid mixed ester type thick multifilament yarn content 78%), and the plasticizer was removed in the same manner as in Example 1. Scouring and dyeing. When the obtained plain fabric was subjected to sensory evaluation, it was found that a natural wrinkle-feeling effect was well expressed and that it had a high quality with a dry texture.

Comparative Example 1
The same pellets as in Example 1 were vacuum-dried at 80 ° C. for 10 hours, melted at a melter temperature of 260 ° C., and introduced into a melt spinning pack having a spinning temperature of 260 ° C., and the discharge rate was 20.0 g / min. Spinning was performed from a spinneret having 36 holes (spinneret spec: hole diameter 0.18 mm, hole length 0.63 mm) under the conditions (spinner back pressure 5.2 MPa).

  The spun yarn is cooled by cooling air (20 ° C.) at a wind speed of 25 m / min from a distance of 4.5 cm below the spinneret surface (yarn speed 1563 m / min at the cooling start point), and an oil agent is applied. After converging, it is taken up by the first godet roller rotating at 2000 m / min, and the winding tension is 0.1 cN / dtex via the second godet roller rotating at the same speed as the first godet roller. It wound up with the winder which rotates at the speed which becomes. The resulting fiber (100 dtex-36 filament) had the properties listed in Table 1.

  Further, when continuous spinning was carried out, the yarn breakage was 0 times, and the spinning operability was very good.

  Using this fiber, a woven fabric was prepared in the same manner as in Example 1 and sensory evaluation was performed. As a result, the surface of the woven fabric was plain (no tone), and no dry feeling was expressed.

Comparative Example 2
The same pellets as in Example 1 were vacuum dried at 80 ° C. for 10 hours, melted at a melter temperature of 260 ° C., introduced into a melt spinning pack having a spinning temperature of 260 ° C., and discharged at a rate of 15 g / min. Spinning was performed from a spinneret having 36 holes (spinneret spec: hole diameter 0.18 mm, hole length 0.54 mm) (back pressure of spinneret 2.7 MPa).

  The spun yarn is cooled by cooling air (20 ° C.) at a wind speed of 20 m / min from a distance of 20.5 cm below the spinneret surface (yarn speed 1196 m / min at the cooling start point), and an oil agent is applied. After being converged, the take-up tension is 0.1 cN / dtex through a second godet roller that rotates at the same speed as the first godet roller. It wound up with the winder which rotates at the speed which becomes. The resulting fiber (100 dtex-36 filament) had the properties listed in Table 1.

  Further, when continuous spinning was carried out, the yarn breakage was one time, and the spinning operability was very good.

  Using this fiber, a woven fabric was prepared in the same manner as in Example 1 and sensory evaluation was performed. As a result, the surface of the woven fabric was almost plain and had no dry texture.

Comparative Example 3
The same pellets as in Example 4 were vacuum-dried at 80 ° C. for 10 hours, melted at a melter temperature of 247 ° C., and introduced into a melt spinning pack having a spinning temperature of 247 ° C., and a discharge amount of 16.9 g / min. Spinning was performed from a spinneret having 48 holes (spinneret spec: hole diameter 0.18 mm, hole length 0.63 mm) under conditions (spinner back pressure 3.1 MPa).

  The spun yarn is cooled by cooling air (20 ° C.) at a wind speed of 25 m / min from a distance of 8.0 cm below the spinneret surface (yarn speed 864 m / min at the cooling start point), and an oil agent is applied. After being converged, the take-up tension is 0.1 cN / dtex through a second godet roller that rotates at the same speed as the first godet roller. It wound up with the winder which rotates at the speed which becomes. The resulting fiber (135 dtex-48 filament) had the properties listed in Table 1.

  Further, when continuous spinning was carried out, the yarn breakage was 0 times, and the spinning operability was very good.

  Using this fiber, a woven fabric was prepared in the same manner as in Example 1 and sensory evaluation was performed. As a result, the surface of the woven fabric was plain and had no dry texture.

Comparative Example 4
The same pellets as in Example 1 were vacuum-dried at 80 ° C. for 10 hours, melted at a melter temperature of 260 ° C., and introduced into a melt spinning pack having a spinning temperature of 260 ° C., and a discharge amount of 33.8 g / min. Spinning was performed from a spinneret having 72 holes (spinneret spec: hole diameter 0.2 mm, hole length 0.6 mm) under the conditions (spinner back pressure 2.3 MPa).

  The spinning yarn is cooled by cooling air (20 ° C.) at a wind speed of 20 m / min from a distance of 51.5 cm below the spinneret surface (yarn speed 2016 m / min at the cooling start point), and an oil agent is applied. After being converged, it is taken up by the first godet roller rotating at 2250 m / min, and the winding tension is 0.1 cN / dtex via the second godet roller rotating at the same speed as the first godet roller. It wound up with the winder which rotates at the speed which becomes. The resulting fiber (150 dtex-72 filament) had the properties listed in Table 1.

  Further, when continuous yarn making was performed, yarn breakage occurred seven times, and the yarn operability was poor.

  Using this fiber, a woven fabric was prepared in the same manner as in Example 1, and sensory evaluation was performed. As a result, the woven fabric had a very dry texture. However, on the surface of the fabric, the difference in color density was too emphasized and the natural appearance was impaired, and the fabric quality was very low.

Comparative Example 5
Cellulose acetate propionate (acetyl group substitution degree: 0.1, propionyl group substitution degree: 2.6, weight average molecular weight: 16 million; CAP-482-20 manufactured by Eastman Chemical Co., Ltd.) 75% by weight A cellulose fatty acid ester composition pellet was obtained by kneading 25% by weight of glycerin diacetate monolaurate at 185 ° C. using a biaxial extruder and cutting to about 5 mm.

  The pellets were vacuum dried at 80 ° C. for 8 hours, melted at a melter temperature of 220 ° C., introduced into a melt spinning pack having a spinning temperature of 220 ° C., and discharged at a discharge rate of 13.3 g / min. (Spinner base spec: hole diameter 0.27 mm, hole length 0.54 mm) was spun from a spinneret having 48 holes (spinner back pressure 0.8 MPa).

  This spun yarn passes through a heating cylinder (15 cm: set temperature 205 ° C.) installed immediately below the spin block, and then a distance of 19.5 cm below the spinneret surface (yarn speed 567 m / min at the cooling start point). After cooling with cooling air (25 ° C) with a wind speed of 18 m / min, applying an oil agent and converging, it is taken up by the first godet roller rotating at 800 m / min, and the same speed as the first godet roller It wound up with the winder rotated at the speed | rate from which the winding tension | tensile_strength became 0.1 cN / dtex via the 2nd godet roller rotated by (1). The resulting fiber (166 dtex-48 filament) had the properties listed in Table 1.

  Further, when continuous spinning was carried out, the yarn breakage was 5 times, and the spinning operability was poor.

  Using this fiber, a woven fabric was prepared in the same manner as in Example 1 and sensory evaluation was performed. As a result, the surface of the woven fabric was nearly solid and had no dry texture.

  The resulting fiber has a thick portion and a fine portion in the fiber axis direction, and by using the thick yarn, a woven or knitted fabric having a dry texture and a natural tone can be obtained, In particular, it can be suitably used for clothing fibers.

The figure which shows one Embodiment of the melt spinning apparatus used for the manufacturing method of the cellulose-fatty-acid mixed ester type | system | group thick multifilament yarn of this invention.

Explanation of symbols

1: Spin block 2: Melt spinning pack 3: Spinneret 4: Cooling start point 5: Cooling device 6: Spinning yarn 7: Oil supply device 8: First godet roller 9: Second godet roller 10: Winding yarn

Claims (5)

A multifilament composed of a composition mainly composed of a cellulose fatty acid mixed ester, wherein the multifilament has a fineness portion and a fineness portion in the fiber axis direction, and satisfies the following formulas (1) to (3): Cellulose fatty acid mixed ester type thick multifilament yarn characterized by the above.
(1) The fineness variation value (U%) is 5 to 20%.
(2) The fiber thickness variation peak value in the fiber axis direction is 20% or less.
(3) The fineness CV% of the single yarn constituting the multifilament is 5 to 15%.   2. The cellulose fatty acid mixed ester-based thick multifilament yarn according to claim 1, wherein the number of thickness variation peaks of 5% or more in the fiber axis direction of the multifilament is 1 to 50 per 10 m.   The cellulose fatty acid mixed ester-based thick multifilament yarn according to claim 1 or 2, wherein the cellulose fatty acid mixed ester is cellulose acetate propionate or cellulose acetate butyrate. A method for producing a cellulose fatty acid mixed ester-based thick multifilament yarn characterized by using conditions satisfying the following formulas (1) to (3) when melt spinning a composition comprising a cellulose fatty acid mixed ester as a main component.
(1) The back pressure of the spinneret is 4 MPa or less.
(2) The relationship between the yarn speed (Vc) and the spinning speed (Vs) at the cooling start point satisfies the following formula.
(Vc / Vs) × 100 ≧ 85
(3) The distance from the spinneret surface to the cooling start point is 5 to 50 cm.   A woven or knitted fabric comprising 50% by weight or more of the cellulose fatty acid mixed ester type thick multifilament yarn according to any one of claims 1 to 3.

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