JPH07331531A - Method for producing modified polyester fiber - Google Patents

Abstract

(57) [Abstract] [Purpose] To stably obtain modified polyester fibers with highly dispersed marbling dyeing properties. [Structure] Crystalline polyamide as a modifier supplied from a twin-screw extruder having deaeration holes capable of depressurizing to 20 Torr or less in a polymer melt stream of polyester containing ethylene terephthalate as a main repeating unit supplied from a main extruder The melt stream is combined with an addition amount of polyamide of 2% by weight or more and less than 10% by weight with respect to polyester to form a composite stream, which is immediately passed through a static mixing and stirring element and spun from a spinneret to produce fibers.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a modified polyester fiber having a modified dyeing property.

[0002]

2. Description of the Related Art Conventionally, various modifiers have been added to polyester to improve fiber performance, impart special functions, and improve texture and dyeability. The method of adding the modifier is roughly classified into the following three methods. A method of adding a modifier during polyester polymerization or before chip formation. A method in which a masterbatch containing a high concentration of a modifier is prepared in advance, blended with a base polymer during spinning, and spun. During melt spinning, in the polymer melt stream after exiting the extruder,
A method in which a melted modifier stream is separately mixed and spun.

Among these methods, the most efficient method suitable for multi-product production is the method. This is also a preferable method from the viewpoint of preventing thermal deterioration of the modifier because the modifier has the least heat history. However, in the method (1), since the difference in melt viscosity between the polymer and the modifier is large and the compatibility is generally low, both are uniformly mixed and fibers having no mixed spots are stably spun. The problem is that it is difficult. Further, when the modifier is separately melted, the viscosity of the meltable modifier is limited, so that there is a problem that a high-viscosity modifier cannot be added.

[0004]

DISCLOSURE OF THE INVENTION The present invention uses a twin-screw extruder to mix and supply a modifier having a high melt viscosity with different dyeing properties when the modifier is mixed in a molten state in polyester. An object of the present invention is to stably obtain a modified polyester fiber having a highly dispersed marbling dyeability, which is highly dispersed by using a static mixing and stirring element.

[0005]

The present invention provides a polymer melt stream of polyester containing ethylene terephthalate as a main repeating unit, which is supplied from a main extruder, at 20 Tor.
The modifier melt streams supplied from a twin-screw extruder having deaeration holes capable of reducing the pressure to r or less are combined to form a composite stream, immediately passed through a static mixing and stirring element, and spun from a spinneret to improve. A method for producing a polyester fiber mixed with a denaturing agent, which comprises using crystalline polyamide as a modifier, and adding the polyamide to the polyester in an amount of 2% by weight or more and less than 10% by weight. It is in the method for producing polyester fibers.

[0006] Preferably, when the composite flow is passed through the static mixing and stirring element, the number of divisions D per element and the total number of steps n
A method for producing a modified polyester fiber using a static mixing and stirring element having a total fluid division number S = D ⁿ of 16,000 or more defined by

The present invention will be described in more detail. FIG. 1 is a schematic diagram showing an example of a melt spinning apparatus for carrying out the present invention.
As shown in FIG. 1, a crystalline polyamide as a modifier, which is supplied from a twin-screw extruder 4 from a screw feeder 2 through a vibration feeder 3 to a polymer melt flow of polyester supplied from a main extruder 1. The polymer melt flow of
At the confluence point 7 via the metering pump 6, they are merged into a combined flow. At this time, the polyamide was melted and kneaded by the two screws in the twin-screw extruder 4 while being mixed at 20 Torr.
It is degassed under reduced pressure below r.

Immediately after the polyester polymer melt stream and the polyamide polymer melt stream are combined into a combined stream at the confluence point 7, the combined stream is passed through a static mixing and stirring element 8.
After being weighed by the metering pump 9, it is supplied to the spinning pack 10, and the polyester fiber mixed with polyamide is spun from the spinneret of the spinning pack.

In the present invention, by using a twin-screw extruder capable of degassing under reduced pressure as a side-feed process, it becomes possible to mix a highly viscous polyamide, which has been difficult to use in the past, with a polyester. It becomes possible to stably melt-spin fibers in which and are highly dispersed and mixed.

In the present invention, the polyester used for feeding from the main extruder is a polyester having ethylene terephthalate as a main repeating unit. For example, terephthalic acid or its dimethyl ester is used as a dicarboxylic acid component and ethylene glycol is used as a diol component. Polyethylene terephthalate is a typical polyester, but a part of the dicarboxylic acid component or the diol component may be replaced by the third component, or the third component may be added. Needless to say, the replacement or addition of the third component may impart disperse dye easy dyeability and cationic dye dyeability other than the disperse dye dyeability originally possessed by the polyester fiber.

Examples of the third component used to replace or add a part of the constituent components of the polyester include isophthalic acid, adipic acid, sebacic acid, 5-sodium sulfoisophthalic acid, diphenyl sulfone dicarboxylic acid,
Dicarboxylic acids such as 1,4-cyclohexanedicarboxylic acid and azelaic acid, diols such as diethylene glycol, tetramethylene glycol and hexamethylene glycol, oxycarboxylic acids such as p-oxybenzoic acid and p-β-oxyethoxybenzoic acid, and bisphenol A. Bis glycol ether, polyalkylene glycol and the like. Further, if the polyester is substantially linear, it may contain polyol such as trimellitic acid, pentaerythritol, monohydric polyalkylene oxide, phenylacetic acid and the like.

The polyester may be synthesized by any known method, for example, obtained by polycondensing a product by a direct esterification method, a transesterification method, an ethylene oxide addition method, or the like. In obtaining the polyester, known catalysts, antioxidants, anti-coloring agents, flame retardants, etc. are appropriately used.

In the present invention, the crystalline polyamide used as a modifier is a polyamide obtained by polycondensing a diamine component and a dicarboxylic acid component, or a lactam or an amino acid, for example, hexamethylenediamine and adipic acid. Nylon 66 by polycondensation,
Examples thereof include nylon 6 obtained by ring-opening polymerization of ε-caprolactam, nylon 612 obtained by polycondensation of hexamethylenediamine and sebacic acid, and nylon 12 obtained by polycondensation of ω-laurolactam or 12-aminododecanoic acid.
In the present invention, nylon 1 is used as the crystalline polyamide.
2 is particularly preferably used.

In the present invention, the polyamide is added in an amount of 2% by weight or more and less than 10% by weight, preferably 4% by weight or more and 8% by weight or less, based on the polyester as a main component. If the amount of polyamide added is less than 2% by weight,
If the difference in dyeability is not obtained and the amount is 10% by weight or more, not only the stability during spinning becomes significantly poor, but also uneven mixed spots occur.

In the present invention, the polyester polymer melt stream and the polyamide polymer melt stream are combined to form one composite stream, and this composite stream is immediately passed through the static mixing and stirring element, which is used in the present invention. The static mixing and stirring element is a mixing device that does not have a drive unit, and an element that is placed in the flow channel and converts the flow channel repeats the action of dividing, reversing, and converting the flow of the fluid, and Mixing is performed. By repeatedly dividing, reversing and converting the flow, the number of divisions of the flow increases exponentially to increase the mixing degree.

Assuming that the number of divisions per stage of the static mixing and stirring element is D and the number of total stages is n, the total number of fluid divisions S is S = D ⁿ
In the present invention, in order to highly disperse the highly viscous polyamide in the polymer stream, it is passed through a static mixing and stirring element having a total fluid division number S = D ⁿ of 16,000 or more. It is necessary, and the total number of divided fluids is preferably 65,000 or more, and particularly preferably 260,000 or more. If the total number of fluid divisions is less than 16,000, the polyamide dispersion is rough and the stability during spinning becomes poor, and the dispersion of polyamide is insufficient, and a satisfactory marbling effect can be obtained for the obtained fiber. Disappear.

A well-known spinneret is applied to the melt spinning in the present invention, and spinning and drawing are performed by a well-known spinning method.
Heat treated to form fibers. The obtained fiber, if necessary,
In order to exert the effect of the fiber of the present invention by shaping it into a processed yarn or the like, or in the form of a woven fabric or a knitted product, or after subjecting it to an alkali weight reduction process, etc., and dyeing it by any means. You can

In the modified polyester fiber according to the present invention, due to the difference in dyeability of its constituent polymers, for example, when dyed with a disperse dye, the polyamide remains white, and when dyed with a disperse dye and a dissimilar acid dye, the polyamide is a polyester. It gives a highly dispersed marbling effect that is different from.

[0019]

EXAMPLES The present invention will be specifically described below with reference to examples. Each property in the examples was measured and evaluated by the following methods. In addition, ◎, ○, △, × of the evaluation in Table 1
Represents extremely good, good, slightly good, and bad, respectively.

Intrinsic viscosity: A sample was dissolved in a phenol / tetrachloroethane (50/50 weight ratio) mixed solvent and measured at 25 ° C. with an Ubbelohde viscometer. Fineness unevenness: The cross section of the drawn yarn was observed with an optical microscope at a magnification of 300 times and visually determined.

Marbled pattern: A woven fabric woven from sample threads was dyed with a 1% by weight dye bath of Terra Seal Blue (Ciba Geigy disperse dye), and the state of dye adsorption was visually determined.

Example 1 Using the melt-spinning apparatus shown in FIG. 1, 2 polyethylene terephthalates having an intrinsic viscosity of 0.71 containing 0.5 wt% of titanium oxide were introduced from the main extruder 1.
Melt-extruded at 90 ° C., while nylon 12 (Daicel Huls Co., Ltd., Daiamide L2140) as a modifier was melt-extruded at 260 ° C. from the twin-screw extruder 4 and supplied from the main extruder 1 by a metering pump 6. The melt flow of nylon 12 was combined with the melt flow of polyethylene terephthalate so that the added amount of nylon 12 was 7 wt% with respect to the polyethylene terephthalate. The composite stream immediately passed through a static mixing and stirring element 8 having 22 stages of two-divided elements per stage, and then this composite stream was supplied to a spinning pack 10 via a metering pump 9.

Thereafter, 24 circular holes each having a hole diameter of 0.25 mm are formed.
After spinning at 272 ° C. through a spinneret having a plurality of spinnerets and cooling the spun yarn with cooling air, an oil agent is added to
It was wound at a winding speed of 0 m / min. Then, it was stretched and heat-treated by a conventional method to obtain a modified polyester fiber of 75 denier / 24 filament. Table 1 shows the evaluation results of the stability during melt spinning when obtaining fibers and the fiber characteristics of the obtained fibers.

(Example 2) A modified polyester fiber of 75 denier / 24 filaments was obtained in the same manner as in Example 1 except that the addition amount of nylon 12 was changed to 3 wt% and the spinning temperature was changed to 275 ° C. Got Table 1 shows the evaluation results of the stability during spinning and the fiber characteristics of the obtained fiber.

Example 3 A modified polyester fiber of 75 denier / 24 filament was obtained in the same manner as in Example 1 except that the number of stages of the static mixing and stirring element was changed to 16. Table 1 shows the evaluation results of the stability during spinning and the fiber characteristics of the obtained fiber.

Comparative Example 1 75 Denier / 24 in the same manner as in Example 1 except that the amount of nylon 12 added was changed to 1.0 wt% and the spinning temperature was changed to 280 ° C.
A modified polyester fiber of filament was obtained. Table 1 shows the evaluation results of the stability during spinning and the fiber characteristics of the obtained fiber.

Comparative Example 2 75 denier / 2 was used in the same manner as in Example 1 except that the amount of nylon 12 added was changed to 15.0 wt% and the spinning temperature was changed to 280 ° C.
A modified polyester fiber of 4 filaments was obtained. Table 1 shows the evaluation results of the stability during spinning and the fiber characteristics of the obtained fiber.
It was shown to. In addition, it was difficult to obtain the fiber stably, and it was not evaluated.

Comparative Example 3 A modified polyester fiber of 75 denier / 24 filament was obtained in the same manner as in Example 1 except that the number of stages of the static mixing and stirring element was changed to 12. Table 1 shows the evaluation results of the stability during spinning and the fiber characteristics of the obtained fiber. It was difficult to obtain the fiber stably.

[0029]

[Table 1]

[0030]

EFFECTS OF THE INVENTION According to the present invention, a crystalline polyamide having a high melt viscosity is supplied in a uniform molten state and highly dispersed in a polyester polymer. It is possible to stably obtain a modified polyester fiber having a marbling tone dyeing property. When the modified polyester fiber obtained by the present invention is dyed, a highly dispersed marbling effect can be obtained.

[Brief description of drawings]

FIG. 1 is a schematic view showing an example of a melt spinning apparatus for carrying out the present invention.

[Explanation of symbols]

 1 Main Extruder 2 Screw Feeder 3 Vibration Feeder 4 Twin Screw Extruder 5 Degassing Hole 6 Metering Pump 7 Confluence Point 8 Static Mixing and Mixing Element 9 Metering Pump 10 Spinning Pack

Claims (2)

[Claims] 1. A melt flow of a modifier supplied from a twin-screw extruder having deaeration holes capable of depressurizing to 20 Torr or less to a polymer melt flow of polyester containing ethylene terephthalate as a main repeating unit supplied from a main extruder. , To form a composite flow, immediately pass through a static mixing and stirring element, spinning from a spinneret to produce a polyester fiber mixed with a modifier, the modifier,
A method for producing a modified polyester fiber, which comprises using a crystalline polyamide and adding the polyamide to the polyester in an amount of 2% by weight or more and less than 10% by weight. 2. A total fluid division number S defined by a division number D per one stage and a total stage number n as a static mixing and stirring element.
= Production method of the modified polyester fiber according to claim 1, wherein the use of static mixing stirring device D ⁿ is 16,000 or more.