KR910009698B1 - Manufacturing method of polyester fiber with excellent color tone and touch - Google Patents

Abstract

No content.

Description

Manufacturing method of polyester fiber with excellent color tone and touch

FIG. 1 is a scanning electron micrograph taken at 2500 times magnification of a cross section of a polyester fiber produced by the method of Example 5 of the present invention.

FIG. 2 is a scanning electron micrograph photographing the cross section of the polyester fiber produced by the method of Comparative Example 2 of the present invention at a magnification of 2500 times.

The present invention relates to a method for producing a polyester fiber excellent in color tone and feel. More specifically, the objective of the present invention is to provide a polyester fiber having a soft touch and subtle color by adding titanium dioxide and calcium carbonate to improve the processability of the manufacturing process and reducing the weight with a caustic soda compound. have.

As well known polyester represented by polyethylene terephthalate, due to its excellent physical properties, it is a material that is used for a variety of applications, including fibers, films, polyester bottles and the like. The present invention also relates to polyester fibers, among other various applications, and is intended to increase its utility by improving problems exhibited when using polyester fibers in advanced medical fields.

In other words, when applied to high-quality medical fields, polyester fibers are slippery and shiny, placed in the desire for soft touch and soft color like natural fibers, especially silk, and the improvement efforts have been made in the four seasons. It has been tried.

Of course, the direction of improvement has been various, but for example, first, a part of the surface of the fiber is eluted with a caustic soda compound, or the fiber obtained by mixing various metal carbonates is treated in a neutral bath rather than an acid to elute the metal carbonate. Although there exists a method of making it, it only raises the problem of too high yellowness, and the effect was insignificant.

Another example is the method of containing titanium dioxide, a white anti-inflammatory agent, which is widely used due to its excellent anti-inflammatory effect, whereas wear damage to a series of devices such as spinnerets, guides, stretching, and combustors It is a cause of coating. However, since there was no suitable anti-inflammatory agent to replace titanium dioxide, research has been conducted to improve the radiosolvent, and the general reality of the industry was to take the damage of the device and treat it as a consumable. This problem is more serious in the recent trend of high speed of general technology trends such as spinning, stretching, and flammable.

On the other hand, in connection with this problem, a method of incorporating fine powdered calcium carbonate into polyethylene terephthalate is proposed in Japanese Patent Application No. 43-12013. In this proposal, a polyester fiber having a small chargeability can be obtained. In addition, it is noted that the addition of large amounts of calcium carbonate can produce significant anti-inflammatory effects. However, when adopting this method, besides the fact that a large amount of calcium carbonate is used, the color tone is remarkably different compared to ordinary fibers, so it is not suitable for medical materials, and more problematic, calcium carbonate, which is contained, is eliminated during post-processing. The color tone changes.

Accordingly, it is an object of the present invention to solve the above-mentioned various problems and to produce polyester fibers having a soft touch and soft color tone as mentioned at the outset.

Hereinafter will be described in detail the configuration of the present invention.

In the present invention, when the viscosity of the polyester polymer is 0.3 or less, 0.01 to 0.3% by weight of calcium carbonate and 2.0 to 3.0% by weight of titanium dioxide are respectively added and diluted in the form of fine powder slurry, and the polymerized polyester is melted and spun. However, the surface of the polyester fiber is treated with a caustic soda compound at any stage after the spinning is made into a knitted fabric, so as to elute 15% by weight or less.

In the present invention, the polyester is mainly made of polyethylene terephthalate or polybutylene terephthalate, but the effect of the present invention is the same for other polyesters. In addition, this invention makes only specific conditions only the addition of the predetermined amount of the above-mentioned fine powder calcium carbonate and titanium dioxide in a slurry state, and it is completely the same as that of usual in other synthesis conditions and methods.

In the present invention, the reason for limiting the addition amount of fine powder calcium carbonate to 0.01 to 0.3% by weight is that less than 0.01% by weight can not achieve the effect of preventing damage to the processing equipment, and when it exceeds 0.3% by weight, the damage prevention effect is enhanced. This may be due to the deterioration of the fiber's properties, especially its radioactivity. In addition, the calcium carbonate used in the present invention is hard and preferably has an average particle size of 1 µm or less, more preferably 0.3 µm or less, and may be further surface-treated with a heat-resistant fatty acid compound for improving dispersibility.

In addition, when titanium dioxide added after completely diluting calcium carbonate is less than 2.0% by weight, the anti-inflammatory effect is insufficient, and when the surface treatment is performed with a caustic soda compound, the degree of pore formation on the surface of the fiber is weak, resulting in an elegant color tone and It is not possible to produce polyester fibers of good hand. If the content exceeds 3.0% by weight, the physical properties and processability of the yarn deteriorate, and the degree of abrasion damage to the device also increases. Titanium dioxide is anatase type with specific gravity of 3.9 and hardness of 2.5 and 5.7, respectively, and may be treated with compounds such as aluminum, silicon, manganese and calcium to improve light resistance, thermal stability, and dispersibility.

The timing of adding these calcium carbonates and titanium dioxide to the polyester is when the viscosity of the polymer before the completion of the polyester synthesis reaction is 0.3 or less, that is, before the system is reduced to a reduced pressure at the beginning of the polycondensation reaction. Add in step. The additive is in the form of a slurry, in particular a slurry of diols represented by ethylene glycol, and the concentration of the slurry is generally 15 to 30% by weight. The most important thing in adding them is the order of their addition, which must first be completely diluted with potassium carbonate and then titanium dioxide. This is because, when the order is reversed, the effect of the present invention cannot be achieved by agglomeration of titanium dioxide in which calcium carbonate is already blended with polyester.

Another element which is an important feature of the present invention is the surface treatment with a caustic soda compound at any stage after the spinning into the final product woven fabric. Of course, it is better to do this after making it into a woven fabric, because this is not for any particular reason, but simply for handling. Caustic soda compounds include sodium hydroxide, potassium hydroxide, triethanol amine, monomethylamine, and the like. Potassium hydroxide and sodium hydroxide are more preferable. Although the aqueous solution concentration of such a caustic soda compound is of course dependent on the kind and processing method of a caustic soda compound, generally speaking, it is good if it is within the range of 40 weight%, more specifically, 10-30 weight%. It is more effective to perform the processing temperature and time within 120 degrees C. and within 2 hours in a few minutes when it is processed under normal high temperature and high pressure. If the caustic soda compound is treated under the same conditions, the polyester containing a lot of titanium dioxide and calcium carbonate has a higher loss ratio and more fine pores are formed. This is due to the fact that titanium dioxide and calcium carbonate contained in the polyester act as nucleophiles to promote the rate of hydrolysis of the ester bond molecular chain and change the dense hydrophobic structure of the polyester itself into a rather loose structure.

The chemical mechanism of hydrolysis and elution of the polyester by the caustic soda compound is described as an example of sodium hydroxide.

The degree of elution by caustic soda compound is 15% by weight or less. The higher the content, the better the feel of the fiber, but the disadvantage is industrial disadvantage due to the increase in the seeding of the solution, for example, the recovery of polyester components. . After surface treatment with a caustic soda compound, the polyester fiber can be washed with water or acidic aqueous solution such as acetic acid or phosphoric acid to neutralize the caustic soda compound to obtain the desired high quality medical material.

According to the present invention, as mentioned at the outset, in addition to preventing wear damage of the fiber manufacturing apparatus, it is possible to obtain a flame-retardant porous polyester fiber having an elegant color tone and a soft touch despite the low loss by caustic soda treatment. have. Hereinafter, the effects of the present invention will be described in more detail with reference to the following examples. However, as is well known, the examples are merely for enabling a large number of people in the same industry to reproduce the effects of the present invention, and it is natural that the entire contents of the invention cannot be included.

In the present Example, viscosity [(eta)] is the intrinsic viscosity measured with 35 degreeC oxochlorophenol solution, and the color tone of filament was shown by L value and b value of colorimeter (X-20). For reference, the larger the L value, the higher the whiteness, and the larger the b value, the higher the yellow side. In addition, melt spinning in the examples was set at a discharge amount of 36.2 g / min.end, a spinning temperature of 295 ° C., a spinning speed of 1500 m / min, a drawing ratio of 3.1, a drawing temperature of 135 ° C., and a winding amount of 2.8 kg of 75 denier 36 filaments.

On the other hand, the wear degree is obtained by chrome plating the surface of the chrome plated metal roller with a diameter of 21 mm at a contact angle of 180 degrees, a tension of 10 g / 75 denier of the driving force and a speed of 100 m / min, and a chrome plated under 10 g / 75 denier tension. The water supply was determined as follows using the wear state of the guide observed under the microscope for 30 hours at 200 m / min.

[Examples and Comparative Examples]

860 parts by weight of terephthalic acid and 390 parts by weight of ethylene glycol were placed in a pressure resistant autoclave and subjected to esterification for 3 hours at 220 to 260 ° C. under nitrogen gas pressure of 3 kg / cm 2 G. Water generated at this time flows out. A fixed amount of trimethyl phosphate is added to the obtained oligomer with antimony trioxide and a heat stabilizer as a polycondensation catalyst. When the viscosity of the low polymer is 0.3 or less, calcium carbonate is added and diluted with 15% ethylene glycol slurry, followed by dilution with titanium dioxide 20% ethylene glycol slurry, and the pressure in the reaction system is gradually reduced while gradually raising the temperature to 0.3. The polycondensation reaction proceeds by heating for 160 minutes under mmHg pressure reduction. The viscosity of the polyester thus obtained is shown in the table together with other measurement elements.

Caustic soda treatment was carried out by melt spinning the polymer to weave with a Tuffeta fabric and then surface treatment with 20 wt% sodium hydroxide and 90 ° C. aqueous solution.

As shown in the table, when carried out in accordance with the configuration of the present invention, it can be seen that an anti-inflammatory porous polyester fiber having a flexible drape and soft touch and elegant color tone while reducing damage to the manufacturing apparatus.

[table]

Claims (3)

In the polymerization of the polyester, when the viscosity of the polymer is less than 0.3, 0.01 to 0.3% by weight calcium carbonate and 2.0 to 3.0% by weight of titanium dioxide are respectively added in a fine powder slurry and diluted sequentially, followed by melt spinning the polymerized polyester. A method for producing a polyester fiber having excellent color tone and feel, which is made of a knitted fabric, and the surface is treated with a caustic soda compound to elute 15% by weight or less. The method according to claim 1, wherein the polyester is polyethylene terephthalate or polybutylene terephthalate. The method of claim 1, wherein the calcium carbonate is a fine powder having an average particle size of 1 μm or less, and titanium dioxide has a specific gravity of 3.9 and a hardness of 2.5 and 5.7, respectively. The manufacturing method of the polyester fiber excellent in the color tone and touch characterized by adding.

Images