KR100616188B1 - Polyester copolymer and preparation thereof - Google Patents

Abstract

The present invention copolymerizes the modifying components used to prepare the di- and basic dye-soluble polyesters in much larger amounts than usual to obtain an initial copolymerized polyethylene terephthalate, which is blended with polyethylenetephthalate in a hot melt state. / Reaction to produce a final copolyester in which the modifying components are contained in a suitable amount for modification, the copolyester of the present invention not only has high productivity and low manufacturing cost, but also has excellent dyeing characteristics, There are advantages such as excellent radiation characteristics.

Description

Polyester copolymer and preparation method thereof             

The present invention relates to a polyester copolymer, and more particularly, a polyester copolymer copolymerized by melting and kneading polyethylene terephthalate (PET) and copolymerized polyethylene terephthalate and having excellent spinning properties and easily dyeing with a basic dye. It is about.

In general, polyester, in particular polyethylene terephthalate (PET) is widely used in fibers, films, containers, general molded products, etc. due to its excellent physical and chemical properties.

PET fibers are highly oriented and hydrophobic, so they are poorly dyed, so they have to be dyed only by using a high temperature high pressure dyeing method of 120 ° C. or higher, or a carrier dyeing method using a carrier. However, these dyeing methods not only consume energy, but also It causes problems such as waste water treatment and deterioration of working environment. In addition, the fibers are damaged due to severe dyeing conditions when blending and blending with fibers such as acetate, wool and nylon.

Therefore, many studies have been conducted in the art for improving the dyeability of polyester, and various methods have been proposed. These methods can be classified into (1) modifying by copolymerizing a component having a functional group capable of imparting an amorphous component or causing steric hindrance, or a component having a group having an affinity with an ionic dye, to the polyester main chain, or (2) The complex obtained by mixing the components is processed, (3) physicochemical treatment is carried out in the spinning and subsequent processes, or (4) these methods are mixed to obtain dye dyeing.

However, the copolymerization method using an acid and an alcohol among these conventional methods has a disadvantage in terms of cost because of low productivity and high production cost because of producing a copolyester by a batch polymerization method. In addition, due to the components added in order to have affinity with the ionic dye, the melt viscosity rises, causing problems with the radioactivity, such as shortening the spin pack replacement cycle occurs.

Therefore, a technical object of the present invention is to provide a polyester having excellent radioactivity and easily dyeing with a basic dye at a low production cost.

In the research for solving the above problems, the present inventors have found that the copolyester reacted by melt blending a polyethylene terephthalate and a specific polyethylene terephthalate copolymer copolymerized at a high molar ratio may have excellent spinning properties and dyeing properties for basic dyes. In addition, the present invention was found to be able to produce a higher productivity and a lower manufacturing cost than a batch polymerization method of copolymerizing copolymerization components in each batch.

Therefore, according to the present invention, in the polyester copolymer,

(a) 3.5 to 10 mol% of 5-sodiumsulfodimethylisophthalate, 5-sodiumsulfo-β-dihydroxyethylisophthalate or mixtures thereof on an acid basis and 3.5 to 10 polyalkylene glycol on a copolymer basis 15 to 50 weights of copolymerized polyethylene terephthalate (hereinafter referred to as "initial copolymerization PET") in which 3.5 to 10 mol% of aliphatic dicarboxylic acids are copolymerized and have an intrinsic viscosity of 0.35 to 0.7 dl / g. %Wow;

(b) Polyethylene terephthalate having an intrinsic viscosity of 0.4 to 0.9 dl / g (hereinafter referred to as "initial polymerization PET") A copolymer in which 50 to 85 wt% is melted and kneaded and reacted (hereinafter referred to as "final copolymer PET" ),

The intrinsic viscosity of the final copolymer PET is 0.35 to 0.7 dl / g, and 1.0 to 5.0 mol% of 5-sodium sulfodimethylisophthalate, 5-sodium sulfo β-dihydroxyethyl isophthalate or a mixture thereof in the final copolymer PET. A polyester copolymer is contained, 1.0-5.0 wt% of polyalkylene glycol or 1.0-5.0 mol% of aliphatic dicarboxylic acid is contained.

According to the present invention, the initial copolymer (a) and polyethylene terephthalate (b) are melted at a high temperature, and kneaded at a temperature of 265 to 300 ° C. for 5 to 30 minutes in a single or twin screw kneader to prepare the final copolymer PET. A method is provided.

Hereinafter, the present invention will be described in more detail.

The present invention copolymerizes the components used to prepare the di- and basic dye-soluble polyesters (hereinafter referred to as " modifiers ") in much larger amounts than usual to obtain this initial copolymerized PET, which It is the main feature to obtain a final copolymerized PET that is blended / reacted with extreme viscosity polyethylenetephthalate in a hot melt state so that the modified components are contained in a suitable amount for modification. Not only the cost is low, but also the dyeing characteristics are excellent and the spinning characteristics are excellent.

In the present invention, the initial copolymerization PET (a) and the initial polymerization PET (b) can be produced by a conventional melt polymerization method.

For example, the initial copolymerization PET (a) is 90 to 96.5 mol% ethylene terephthalate oligomer; 3.5-10 mol% of 5-sodiumsulfodimethylisophthalate, 5-sodiumsulfo-β-dihydroxyethylisophthalate or mixtures thereof; 3.5-10% by weight of polyalkylene glycol on the basis of copolymer or 3.5-10 mol% of aliphatic dicarboxylic acid on the basis of acid component; And it can manufacture by making it condensate-polymerize under vacuum after making required amount of ethylene glycol react. Wherein 5-sodiumsulfodimethylisophthalate or 5-sodiumsulfo-β-dihydroxyethylisophthalate is added to impart salting resistance to basic dyes, and polyalkylene glycols or aliphatic dicarboxylic acids can be used to improve dyeability. It is added to lower the melt viscosity during the polymerization. At this time, if the content of the above modified components is less than the lower limit, the modification effect of the final copolymerized PET is insufficient, and if it exceeds the upper limit, it is difficult to achieve the desired ultimate viscosity by the rise of melt viscosity during synthesis. .

Initially polymerized PET can also be prepared in a similar manner.

According to the present invention a method of blending these initial polymers (a, b) in a single screw or twin screw extruder is used to melt blend at high temperatures to produce the final copolymerized PET. In this case, the prepared initial polymer chips are mixed together. Each initial polymer fed to the melt kneader is melt kneaded and reacted at a temperature of 265 to 300 ° C. for 5 to 30 minutes to form a copolyester.

If the kneading temperature is less than 265 ° C., the difference in melting point with the polymer becomes small, resulting in insufficient kneading and reaction, making it difficult to obtain a uniform final copolymer PET, and if it exceeds 300 ° C., thermal decomposition occurs, which is undesirable. In addition, when the kneading time is less than 5 minutes, sufficient kneading with the reaction is not performed, and uniform copolyester is hardly obtained, and when 30 minutes or more, thermal decomposition causes undesirable.

The ratio of melt blending is preferably 50 to 85% by weight of the initial polymerization PET (a) and 15 to 50% by weight of the initial copolymerization PET (b).

The final copolymerized PET in the form of a mixture obtained after melt kneading may be prepared in the form of chips or pellets after solidification, or may be spun, crimped and stretched using a conventional PET fiber production apparatus in a molten state. The final copolymerized PET of the present invention not only has excellent dyeing properties but also blends different materials in a molten state during spinning, so that the pack exchange cycle is long because of excellent spinning properties. The main reason why the radiation characteristics are individual is that the melt viscosity is lowered when blending different materials in the molten state during spinning.

Features and other advantages of the present invention as described above will become more apparent from the following examples. However, it should be understood that the present invention is not limited to the following examples.

The measurement of the evaluation item shown in the following Example is as follows.

* Measurement of mole% of 5-sodiumsulfodimethylisophthalate: Mole% of 5-sodiumsulfodimethylisophthalate of the copolymerized polyester was dissolved in acetic acid with trifluoroacetic acid, followed by proton nuclear magnetic resonance apparatus (1H NMR) (Bruker It measured using DRX-300).

Melting point measurement: The melting point was measured using a differential differential scanning calorimeter (Perkin Elmer DSC-7).

* Intrinsic Viscosity (IV): The chip was dissolved in spent phenol / tetrachloroethane (weight ratio 50/50) to make 0.5 wt% solution, and measured at 25 ° C. with a Uberod viscometer.

* Measurement of absorption rate during dyeing: The dyeing rate by basic dye is Kayakryl Red (basic dye) 1.5% owf acetic acid 0.2 g / l, bath ratio 50: 1, after 60 minutes dyeing at 98 ℃ before and after dyeing The salt absorbance was quantified using an ultraviolet-visible spectrometer and determined by the following equation.

Absorption rate = 100 (A-B) / A

Where A = concentration of the saline solution before dyeing                     

        B = concentration of saline solution after dyeing

* Radioactivity measurement: Radioactivity was judged as the number of cuts during winding for 60 hours at a constant spinning speed (1000 m / min). The smaller the number of cuttings, the better the radioactivity.

* Pack change cycle measurement: The filter replacement cycle is defined as 5 meshes of 2cm in diameter and the flow rate is 50 g / min, and the pressure is more than twice the initial pressure.

EXAMPLES 1-4

In Example 1, 7 mol% of 5-sodiumsulfodimethylisophthalate and 7 wt% of polyethylene glycol having a molecular weight of 1000 were added to synthesize initial copolymerized PET, and melt blended by mixing 22 wt% of the initial copolymerized PET and 78 wt% of polyester. And was carried out in the same manner as in Example 2 except that 7 mol% of 5-sodiumsulfo β-dihydroxyethylisophthalate was used instead of 7 mol% of 5-sodiumsulfodimethylisophthalate of Example 1.

In Example 3, 7 mol% of 5-sodiumsulfodimethylisophthalate, 5 wt% of polyethylene glycol having a molecular weight of 1000, and 5 mol% of sebacic acid were added to synthesize an initial copolymerized PET, and 22 wt% of the initial copolymerized PET and 78 weight of polyester. % Was blended and melt blended to spin,

In Example 4, 5 mol% of 5-sodiumsulfodimethylisophthalate and 5 wt% of polyethylene glycol having a molecular weight of 1000 were added to synthesize an initial copolymerized PET, and the initial copolymerized PET was mixed with 30% by weight of 70% by weight of polyester. Melt blended and spun.

Confirmation that the initial polymers formed into a homogeneous final copolymerized PET was performed using a nuclear magnetic resonance apparatus (1H NMR). The final copolymer PET melt-spun at 280 ° C. at a rate of 1,000 m / min is stretched under the conditions of drawing temperature of 75 to 85 ° C., drawing ratio of 3.4 to 3.7 and heat setting temperature of 190 to 230 ° C. to obtain 80 denier / 24 filament fibers. Prepared.

Comparative Example 1

As a general method for preparing a dibasic and basic dye salting polyester, 1.5 mol% of 5-sodiumsulfodimethylisophthalate and 1.5 wt% of polyethylene glycol were added to terephthalic acid and ethylene glycol, and spun in the same manner as in Example 1. . At this time, the radioactivity and workability were significantly worsened by high melt viscosity, and the pack change cycle and the removal rate were also low.

Comparative Example 2

In Comparative Example 2, 15 mol% of 5-sodiumsulfodimethylisophthalate and 15% by weight of polyethylene glycol were polymerized into a high molar ratio of copolymerized polyester prepolymer. 10% by weight of this initial polymer and 90% by weight of polyester were melt blended and spun. When the high molar ratio copolymerized polyester prepolymer was polymerized with 15 mol% of 5-sodiumsulfodimethylisophthalate and 15% by weight of polyethylene glycol, the melt viscosity increased and the ultimate viscosity could not be increased as desired. Significantly poor radioactivity and workability and low rate of absorption.

Comparative Example 3

In Comparative Example 3, only 7 mol% of 5-susdiumsulfodimethylisophthalate was added, and no copolyester was added without any other polyalkylene glycol or aliphatic dicarboxylic acid, followed by melt blending in the same manner as in Example 1. Spinning. In this case, too, the melt viscosity increased, so that the ultimate viscosity could not be increased as desired. As a result, the melt-blended polymer showed significantly poor radioactivity and workability, and a low absorption rate.

 division Intrinsic Viscosity of Prepolymer (g / g) Final PET  PET Initial Copolymer PET DMS mole% Intrinsic viscosity (㎗ / g) Melting Point (℃) Dust removal rate (%) Radioactive Pack change interval (hours) Example 1 0.64 0.50 1.49 0.47 249 98.0 0 10 Example 2 0.64 0.49 1.48 0.47 249 97.5 0 10 Example 3 0.64 0.53 1.48 0.49 248 98.3 0 11 Example 4 0.64 0.53 1.49 0.47 248 98.1 0 10 Comparative Example 1 - 0.55 1.47 0.49 245 91.5 3 4 Comparative Example 2 0.64 0.32 1.47 0.33 247 89.2 4 6 Comparative Example 3 0.64 0.37 1.48 0.38 250 90.6 2 6

As shown in Table 1, the PET initial polymer and the copolymerized polyethylene terephthalate prepolymer polymerized at a high molar ratio were prepared, respectively, and the samples were spun and stretched after obtaining the copolymerized polyester by melt blending and reacting at a high temperature. When the subsequent radioactivity, workability, pack change cycle, and reduction rate were measured, better results were obtained than the di- and basic dye-based dyes obtained through the conventional batch polymerization process, and the dyeing properties were improved through the present invention. Productivity can be increased, manufacturing costs can be lowered, and radioactivity and workability are improved and pack change intervals are expected to be extended.

Claims (2)

In the polyester copolymer, (a) 3.5 to 10 mol% of 5-sodiumsulfodimethylisophthalate, 5-sodiumsulfo-β-dihydroxyethylisophthalate or mixtures thereof on an acid basis and 3.5 to 10 polyalkylene glycol on a copolymer basis 15 to 50% by weight of copolymerized polyethylene terephthalate (initial copolymerized PET) having 3.5 to 10 mol% of aliphatic dicarboxylic acid copolymerized on the basis of weight% or acid component and having an intrinsic viscosity of 0.35 to 0.7 dl / g; (b) a copolymer (final copolymer PET) in which 50 to 85% by weight of polyethylene terephthalate (initial polymerization PET) having an intrinsic viscosity of 0.4 to 0.9 dl / g is melted and kneaded and reacted; The intrinsic viscosity of the final copolymer PET is 0.35 to 0.7 dl / g, and 1.0 to 5.0 mol% of 5-sodium sulfodimethylisophthalate, 5-sodium sulfo β-dihydroxyethyl isophthalate or a mixture thereof in the final copolymer PET. It is contained, 1.0-5.0 weight% of polyalkylene glycols, or 1.0-5.0 mol% of aliphatic dicarboxylic acid is contained, The polyester copolymer characterized by the above-mentioned. In the method for producing a polyester copolymer, (a) 3.5 to 10 mol% of 5-sodium sulfodimethylisophthalate, 5-sodium sulfo-β-dihydroxyethyl isophthalate or a mixture thereof on the acid component basis, and air Copolymerized polyethylene terephthalate (initial copolymerized PET) having 3.5-10% by weight of polyalkylene glycol on the basis of copolymerization or 3.5-10 mol% of aliphatic dicarboxylic acid on the basis of acid component and having an intrinsic viscosity of 0.35 to 0.7 dl / g. 50 wt%; (b) 50 to 85% by weight of polyethylene terephthalate (initial polymerization PET) having an intrinsic viscosity of 0.4 to 0.9 dl / g is melted at a high temperature and kneaded at a temperature of 265 to 300 ° C. for 5 to 30 minutes in a single or twin screw kneader. Method for producing a polyester copolymer, characterized in that it comprises the steps of.