JPS6366322A - Production of polyester fiber - Google Patents

Abstract

PURPOSE:To obtain a stable polyester fiber suppressing the generation of fluffing and end breakage, by extruding a polyester containing a specific amount of fine powder of an inert substance through a nozzle and subjecting to melt- spinning at a specific take-up speed. CONSTITUTION:Inert fine particles having an average diameter of <=1mu or aggregate of inert fine particles having an average aggregate diameter of <=1mu (e.g. colloidal silica, titanium oxide, alumina, etc.) are dispersed in a polyester at an amount of 0.5-10wt% to obtain a polyester containing >=5 particles or aggregates to said inert substance per 10mu<2> of the cross-section of the polyester. The polyester containing the fine particles or aggregates is extruded through a spinning nozzle and melt-spun at a take-up speed of >=1,000m/min, preferably >=3,000m/min to obtain the objective polyester fiber.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a method for producing stable polyester yarn with less fuzz, yarn breakage, etc. by incorporating a fine particulate inert substance into polyester.

<Prior Art> Polyester, represented by polyethylene terephthalate, is widely used as a material for fibers due to its many excellent physical properties. Polyester fibers are usually subjected to melt-spinning, drawing, and heat-setting processes, but from the perspective of the manufacturing process, there are two steps: winding the undrawn yarn onto a bobbin, and drawing and heat-setting it. It goes through two steps.

In recent years, a so-called spin-draw method has been proposed in which these two steps are directly connected in the same system, and the fiber is heated, stretched, and wound immediately after spinning. This type of spin-drawing method saves labor by simplifying the process as described above, and since spinning and drawing are performed in the same system, the drawing speed is significantly increased compared to the conventional method, which reduces production. Improves sex. In particular, recently, high-speed winding machines that can wind at speeds of 6,000 mm or more have appeared, making it possible to perform high-speed stretching at speeds of 6,000 mm or more, leading to further labor savings and improved productivity. Nittsuta.

However, when attempting to put these streamlining processes into practical use, the stretching speed of the spin-draw method is significantly higher than that of the conventional stretching method, so it is necessary to use the heating pins and heating rollers that have been used in the past. I can't. For example, Japanese Patent Publication No. 48-17606 describes that the feed roller's artificial side is roughened. Furthermore, JP-A-56-169806 discloses the use of rollers with grooves in the axial direction. aimed at suppression. It is widely used in the production of polyester fibers to create protrusions on the fiber surface by dispersing inert fine particles such as titanium oxide in the polyester itself, which also has a matting effect and reduces fuzz and yarn breakage. ing. For example, special public service in 1977
Publication No. 39055 states that the particle size is 10 microns to 150 microns.
Additions of 0.05-30% micron silica have been shown. Among the above methods, processing the roller surface requires special processing to suit the purpose, which increases equipment costs, and requires rounding to maintain a certain roughness of the surface processing area.Re-plating is required after a certain period of use. Maintenance costs will be higher if required. Furthermore, the above-mentioned methods of adding inert fine particles such as titanium and silica have large particle diameters and are insufficient to suppress the desired occurrence of fuzz and yarn breakage. By the way, in the process of streamlining the silk-spinning process, in addition to the above-mentioned spin-draw method, a high-speed spinning method that increases the take-up speed during spinning is already known. Spinning speed 2500~4000-
The partially oriented yarn (poy) obtained by binding is subjected to an I-drawn false twisting process (DTY) and used as a processed yarn.

Furthermore, in recent years, the spinning speed has been increased to over 4000W, and even 50W.
By setting the value to 0 - or more, fibers that can be used as raw silk and have physical properties close to those of conventional drawn yarns can be produced all at once within the spinning process. However, when attempting to put ultra-high-speed spinning as described above into practical use, yarn breakage and fuzz occur frequently during spinning, and although productivity is high, the amount of loss due to yarn breakage increases], making it difficult to put it into practical use. It is. As a countermeasure for this, the invention of JP-A No. 57-42920 has 0.001
A method of adding ~0.05 molty metal carboxylate,
The invention of JP-A-57-42922 discloses a method of adding P-hydroxybenzoic acid, and the invention of JP-A-58-144117 discloses a method of adding fatty acid polyester. All of these methods are effective to some extent in suppressing the diameter of spherulites formed during spinning, but are insufficient in reducing fuzz generation and yarn breakage.

<Problems to be Solved by the Invention> The present invention aims to reduce the occurrence of fuzz and yarn breakage that occur when using a high-speed spinning method or a spin-drawing method. is 30
High-speed spinning method exceeding 00fV5+ and winding speed of 3
The present invention provides a method that exhibits a dramatic effect on reducing fuzz and yarn breakage in spin-draw methods exceeding 000-.

<Means for Solving the Problems> The present invention provides that inert fine particles having an average diameter of 1 micron or less or aggregates of inert fine particles having an average diameter of 1 micron or less are 0.
Made of polyester dispersed in 5 to 10% by weight,
A method for producing polyester fiber, which comprises extruding a polyester in which at least 5 particles or aggregates are dispersed per 10 square microns of cross section of the polyester through a nozzle, and spinning the polyester at a take-up speed of 1000 m/min or more. This solved all of the above problems.

Japanese Patent Publication No. 59-24233 discloses that by adding fine particulate inert substances such as those mentioned above to polyester synthetic fibers, fine and complex unevenness is created on the fiber surface, resulting in excellent color development of dyed products and silk. It has been shown that fibers with excellent hand properties similar to those of This manufacturing technology has already been put into practical use and is attracting attention in the market as a unique fiber. The present invention provides an unexpected and remarkable effect in that when this technology is applied to high-speed spinning or spin-drawing, yarn breakage and fuzz generation during high-speed spinning or high-speed drawing are suppressed. This is what we discovered.

Generally, when polyester is spun at a spinning speed of around 1000 m/min, the resulting polyester fibers are poorly oriented and non-crystalline, but as the spinning speed increases, the molecules become more oriented and crystallized, resulting in ultra-high speeds of over 40001 min. In this case, crystallization proceeds rapidly (formation of spherulites) before molecular orientation progresses sufficiently, and voids or other voids may be observed within the fibers. Furthermore, due to the increase in air resistance on the fiber surface, #l! The non-uniformity of fiber cross-sectional cross-sectional director orientation, the so-called skin-core structure, becomes very large. Polyester fibers obtained by ultra-high speed spinning with these characteristics prevent yarn breakage and fuzz generation during oil supply, godet rollers, guides, winder traverse guides, etc. during the spinning process. As a countermeasure against this, in the present invention, the average diameter of 1 micron, preferably 0.
．． Inert fine particles or fine particle aggregates of 6 microns or less act as a nucleating agent to suppress oriented crystallization, and these characteristic particles or aggregates create fine and complex irregularities on the fiber surface, so guides, rollers, etc. Damage to the yarn surface due to
It is thought that the occurrence of fuzz will be reduced.

Next, it was found that the effect of such fine particles is significant even in the direct spinning drawing method, which involves high-speed drawing and heat treatment.

In the direct spinning drawing method, even if the spinning speed, that is, the first take-off speed is 1,000 frV5+, the drawing speed is 3,000 or more, usually around 4,000 W, and drawing is performed at a very high speed. In this high-speed drawing and heat treatment, as mentioned above, the fine particles not only have the effect of roughening the yarn surface, but also have the effect that these fine particles play a role like "rolls" in the stretching of molecules during high-speed stretching. It is thought that smooth stretching is possible. Currently, an ultrahigh-speed direct drawing method that combines ultrahigh-speed spinning and direct drawing is gradually being put into practical use, but it is even more important to improve spinnability and stretchability by adding fine particles such as those mentioned above. Become something. Furthermore, as described in Japanese Patent Publication No. 59-24233, the obtained polyester yarn is subjected to post-treatment to improve color development in dyeing, deep color tone, and silk-like texture. From this point of view as well, it has excellent functionality for use in clothing.

Examples of inert fine particles that exhibit the above-mentioned effects include titanium oxide, alumina, and calcium carbonate, but colloidal silica, in which silica fine particles with an average particle size of 1 mm to 100 mm exist in the form of single particles, is particularly effective. is good. This colloidal silica is one in which fine particles containing a silicic acid compound as a main component exist as a colloid in water, monohydric alcohols, diols, or a mixture thereof as a dispersion medium.

Since polyesters used for ultra-high speed spinning or high-speed drawing need to be highly homogeneous polymers,
It is necessary to disperse the fine particulate inert material of 10 weights and 1 tq6 as much as possible without causing large aggregation of single particles. In particular, when colloidal silica is added to a high-temperature melt, thermal aggregation tends to occur, and it is difficult to redisperse the resulting agglomerates. If the aggregates are large, they will accumulate in the back filter and nozzle hole during spinning, resulting in a significant disturbance in the spinning condition. The method of investigating the dispersion state of added fine particles is to slice the chips before spinning or the fibers after spinning using an ultramicrotome into a thickness of several tens of millimeters to around 100 millimeters, and then transmit the sliced ultrathin sections. The method used is magnified observation using an electron microscope. Usually, the added fine particles are not dispersed as single particles, but are observed in a state where single particles P are aggregated. This state is defined as a secondary particle in the above-mentioned Japanese Patent Publication No. 59-24233, and according to this, if the maximum distance from one end of the secondary particle to the other is the size of the secondary particle (clump diameter). , the average size of the secondary particles is 1 micron or less, preferably 0.6 micron or less, and 10
There must be at least 5 or more particles per square micron. If the size of the secondary particles exceeds 1 micron, especially exceeds 5 microns, it is not preferable because the back filter becomes severely clogged and the spinning condition becomes poor. Further, even in the case of fine particles that do not aggregate, it is essential that the average diameter and number of particles exist within the above range for the same reason as above.

The amount of inert fine particles or inert fine particle agglomerates in the polyester should also be between 0.5 and 10% by weight. If it is less than 0.5% by weight, the effect of suppressing the occurrence of fuzz and yarn breakage will be small, and if it exceeds 10% by weight, the spinnability will be poor.

The polyester fibers obtained by the method of the present invention have a fiber cross section that is not only round but also trilobal, T-shaped, quadrilobal, pentalobal,
It may have a multi-lobed shape such as an eight-lobed shape or various cross-sectional shapes.

The polyester in the present invention is a polyester having 85 moles or more of ethylene terephthalate units,
At 15%' adipate, sepacate, bipenzoate, hexahydroterephthalate, diphenoxyeta/-
It may also contain other dicarboxylates such as 4,4'-dicarboxylate and 5-sulfoisophthalate groups. In addition to ethylene glycol, glycols include
Tetramethylene glycol, hexamethylene glycol-A
/, ) IJ xf L/ glycol, tetraethylene glycol or mixtures thereof can also be used.

Other substances such as matting agents, gloss improvers, anti-tarnish agents, etc. may be added to the polymer.

The method of the present invention exhibits remarkable effects particularly in high-speed spinning methods in which the take-up speed is 3000 ry minutes or more or in spin-draw methods in which the winding speed is 3000 ry minutes or more. In particular, high-speed spinning method with a take-up speed of 4000 or more and a winding speed of 4000 at a stretching ratio of 1.05 to 4.0 times.
A spin-draw method using rrv minutes or more is preferable.

The present invention will be explained below using examples.

Example 1 An aqueous silica sol with a concentration of 20 wt% having a particle size distribution in the range of 10 to 20 millimicrons was mixed with ethylene glycol at room temperature, and after thorough stirring, the molar ratio of terephthalic acid, the ethylene glycol, and terephthalic acid was The slurry was adjusted so that the ratio was 1.2 and mixed to obtain a slurry containing silica. This slurry was heated to a temperature of 250℃ and an internal pressure of 1.2K.
Esterification was carried out by continuously feeding the mixture into an esterification tank with p/1-dG to obtain an esterified product with an esterification rate of 98 degrees, followed by polymerization at 285°C to obtain an intrinsic viscosity [η1 =
A polyester of 0.68 was obtained. The amount of silica added in this case was 3 wt% based on the polymer. The polyester was melt-spun through a 36-hole nozzle at a circumferential speed of 1500 m/s.
Immediately after heating, it is taken up by the first take-up roller at a peripheral speed of 4.
It was stretched to 2.8 times with a 200 rrv'5+ second take-up roller, heat-set, and then rolled up. The physical properties of the yarn obtained by such a direct spinning drawing method were as follows, and a polyester fiber having good yarn quality without fluff or yarn breakage was obtained.

The obtained fibers were sliced with an ultra-thin section using a transmission electron microscope, and the dispersion state of the secondary particles is shown in Table 1. 0.5μ or less, 0.
The number of particles each having a diameter of 6 to 1.0 μm and 1.0 μm or more was calculated by measuring 10 square microns. In addition, where the silica content exceeded 10 wt%, the spinnability was poor and no yarn could be collected.

Physical properties of polyester, fineness: 72.5d/36
f strength: 4.79 t/d elongation: 38.0% water production shrinkage rate (wsr): 6.7 t/d U%: 0.6
0% Example 2 Same as Example 1 except that the product denier in Example 1 was 50 d/36f, the circumferential speed of the first take-up roller was 1600 rV5 + the circumferential speed of the second take-up roller was 4000 - the binding stretch ratio was 2.5 times I went with the conditions. Product denier is 75d →
Although the length was reduced to 50 d, the result was good with no fluff or yarn breakage.

Example 3 The same conditions as in Example 2 were carried out except that the amount of silica added in Example 2 was limited to 1 wt%. As in Example 2, fluff and
It was in good condition with no thread breakage.

Comparative Examples 1 to 2 Comparative Example 1 is a case in which the amount of silica added in Example 2 is zero, so-called superbride, and Comparative Example 2 is a case in which 0.5 wt% of titanium oxide with a particle size of 200 mμ is added. are respectively shown in fC.

In the case of Comparative Example 1, fuzz was observed and many broken yarns were wound around the second take-up roller, resulting in a poor quality. 1 for comparative example 2
．． Many secondary particles of 0μ or more were observed, and although there was no yarn breakage, fluff was observed.

Comparative Example 3 The slurry containing silica in Example 1 was heated to a temperature of 2.
The same conditions as in Example 1 were used except that a polyester polymer was continuously supplied to an esterification tank at 60° C. to promote thermal aggregation.

The dispersion state of silica particles in the obtained fibers was poor and 1, θ
There were many secondary particles of μ or more, and a lot of fuzz was generated during stretching.

Comparative Example 4 The same conditions as in Example 2 were carried out except that the amount of silica added in Example 2 was changed to Q, 3 wt%. Occurrence of fuzz and yarn breakage was observed during spinning and drawing. Furthermore, the texture after alkali reduction was also poor.

Example 4-6 Polyester obtained by the same method as Example 1 was
When melt spinning from a 6-hole nozzle, the spinning speed is set to 3.
The power was changed to 200 rrv'f+, 5500-min, and 6000W, and yarn was collected. Example 4 is partially oriented yarn (poy)
The yarns were made into processed yarns after being drawn and false-twisted (DTY), and Examples 5 and 6 were so-called ultra-high-speed spinning yarns, which were very good with very little yarn breakage and fluffing compared to the conventional method.

Comparative Example 5 The same superplyte polymer as in Comparative Example 1 was wound at a spinning speed of 6000 nv'5), but the yarn was defective due to many breakages and fuzz during spinning.

Comparative Example 6 The same polyester polymer as in Comparative Example 3 was used and wound at a spinning speed of 6000 tx, but fuzz was observed in the wound cheese and the yarn quality was insufficient.

The above results are summarized in Tables 1 and 2.

Table 2

Claims (1)

[Claims] 1. Inert fine particles with an average diameter of 1 micron or less or inert fine particle aggregates with an average aggregate diameter of 1 micron or less are 0.5 to 1.
A polyester in which 0% by weight of the fine particles or aggregates are dispersed and in which at least 5 fine particles or aggregates are dispersed per 10 square microns of cross section of the polyester is extruded through a nozzle and melt-spun at a take-up speed of 1000 m/min or more. A method for producing polyester fiber, characterized by: 2. The manufacturing method according to claim 1, wherein the take-up speed is 3000 m/min or more. 3. The manufacturing method according to claim 1, which uses a direct spinning drawing method in which the yarn is taken up at a take-up speed of 1,000 m/min or more, stretched immediately without being rolled up, and then rolled up at a speed of 3,000 m/min or more.