KR100436722B1 - Method for preparing thermally adhesive polyester-type binder fiber - Google Patents

Abstract

The present invention relates to (a) 70 to 90 mole% of terephthalic acid and / or ester forming derivatives thereof and 10 to 30 mole% of ester forming derivative compounds of phthalic anhydride (or ortho-phthalic acid) represented by the following general formula (1): Heat-adhesive polyester-based binder fiber for polycondensation reaction of an acid component of dicarboxylic acid composed of phthalic anhydride and (b) a diol component composed of 75 to 90 mol% ethylene glycol and 10 to 25 mol% neopentyl glycol It relates to a manufacturing method of. The binder fiber according to the present invention exhibits high adhesion and excellent feel and has a high glass transition temperature, which not only reduces the occurrence of fusion yarn of short fibers, but also makes it possible to manufacture high quality polyester nonwoven fabric having good color with improved productivity. Let's do it.

Description

Method for preparing thermally adhesive polyester-based binder fiber {Method for preparing thermally adhesive polyester-type binder fiber}

The present invention relates to a method for producing a heat-adhesive polyester-based binder fiber used in the production of nonwoven fabrics and padding products, more specifically terephthalic acid and / or its ester-forming derivatives and phthalic anhydride (or ortho) -Condensation polymerization of the acid component consisting of ester-forming derivative compounds of phthalic acid and the diol component composed of ethylene glycol and neopentyl glycol results in high adhesion and excellent touch, and the high glass transition temperature significantly reduces the occurrence of fusion. Rather, the present invention relates to a method for producing binder fibers having good heat-adhesive copolyester.

In general, nonwoven fabrics and padding products for garments are widely known by carding short fibers, laminating several layers of carding web products in the machine direction and the semi-machine direction, and making interfiber adhesion between fibers as an adhesive material (binder). have. There are two main methods for manufacturing such a nonwoven fabric, and the first method is to dissolve an acrylic or polyvinyl alcohol-based resin in a solvent and apply the adhesive to the surface of the nonwoven fabric. As described above, a binder fiber prepared by complex spinning in the same system or sheath-core type having a low melting point in a matrix fiber is mixed at the time of carding and then bonded to the constituent fibers by heat treatment.

However, in the first method, the method of dissolving and spraying an acrylic or polyvinyl alcohol-based resin in a solvent is not only able to penetrate deeply into the inside of the web, but also with environmentally contaminated solvents and polyesters which form a matrix. Due to low compatibility and the like has a disadvantage of low adhesiveness and poor touch. Therefore, as in the present invention, the heat-adhesive adhesive which does not use a solvent has a great advantage that the adhesion is instantaneously completed by heating, and contributes to the rationalization of the bonding process, the reduction of personnel, and the high speed even in the field of fiber adhesion. Many bars have been developed and commercialized. In particular, it is not necessary to mention that the bonding conditions must be gentle, since in the case of adhesive sewing of clothing textile products and the like, the texture, color tone, etc. of the product are important.

Generally, as binders for adhesive fibers such as nonwoven fabric binders and padding products, conventional polyethylenes, polypropylenes, polyamides, ethylene-vinyl acetate copolymers, and the like are known. It is not enough and is not a satisfactory level in terms of the feel of the bonding portion. For example, copolymerized polyamide adhesives containing nylon 11 and nylon 12 having relatively high adhesive strength and excellent solvent resistance have a large temperature dependence of melt viscosity, and a decrease in adhesive strength during use, and also good feel of the adhesive portion. Not only is it difficult to do this, but it also has defects such as yellowing caused by sunlight. On the other hand, the polyester-based binder fiber having a high affinity with the polyester-based fiber has not only excellent adhesion but also good touch and daylight resistance.

The heat-adhesive polyester-based binder fibers known so far use terephthalic acid, isophthalic acid and aliphatic dicarboxylic acids having 30 or less carbon atoms as aromatic dicarboxylic acid components, and neopentyl glycol, tetramethylene glycol, polyethylene glycol, etc. as diol components. Most of them are.

For example, the main components of terephthalic acid and isophthalic acid include a method for producing a low melting polyester using a method such as US Pat. No. 4,129,675. In this case, a temperature of 190 ° C or higher is required for thermal bonding. There is an economic disadvantage.

U.S. Patent No. 4,166,896 introduces a process for preparing unsaturated polyesters by copolymerizing unsaturated dicarboxylic acids and the like on low molecular weight depolymerized polyesters. This fiber also has the disadvantage of low economical efficiency, too high melting point, high crystallinity to use as an adhesive.

U.S. Patent No. 4,065,439 discloses a method for preparing low melting polyester using terephthalic acid / isophthalic acid / adipic acid (or sebacic acid) and ethylene glycol / neopentyl glycol, but in this case the melting point of the obtained adhesive is 45 to Very low to 60 ℃ has a disadvantage that is difficult to use as a wick for clothing.

In British Patent No. 788,377, Japanese Patent Application Laid-Open No. 8-143,657, and Korean Patent Publication No. 96-9776, the position of the carboxyl group is another copolymer material capable of realizing an amorphous molecular structure. Attempts have been made to polymerize using more bendable phthalic acid or phthalic anhydride in the ortho position. However, in the case of phthalic anhydride, the higher the content in the copolymer, the greater the drop in glass transition temperature, which causes problems of fusion between fibers during the stretching process, product transportation, or dropping.

Therefore, in the present invention, the acid component consisting of 70 to 90 mol% of terephthalic acid and / or its ester forming derivative and 10 to 30 mol% of phthalic anhydride in ester forming derivative of phthalic anhydride (or ortho-phthalic acid) and 75 to Condensation polymerization of a diol component consisting of 90 mol% ethylene glycol and 10-25 mol% neopentyl glycol results in high adhesion and excellent touch. The high glass transition temperature significantly reduces the occurrence of fused yarn and good color. Adhesive copolyester has developed a method for producing binder fibers.

Therefore, the object of the present invention is excellent adhesion with the polyester to be adhered, good touch after the adhesion, high glass transition temperature not only significantly reduces the occurrence of fusion of fibers but also good color and high quality It is to provide a method for producing a heat-adhesive co-polyester-based binder fiber suitable for producing a polyester nonwoven fabric of.

In order to achieve the above object, the method for producing a heat-adhesive polyester-based binder fiber of the present invention is (a) 70 to 90 mol% of terephthalic acid and / or its ester-forming derivative and phthalic anhydride represented by the following formula (1) Or an acid component of dicarboxylic acid composed of 10 to 30 mol% phthalic anhydride in an ester-forming derivative compound of ortho-phthalic acid), and (b) 75 to 90 mol% ethylene glycol and 10 to 25 mol% neo The diol component composed of pentyl glycol is subjected to a polycondensation reaction, and the ester-forming derivative compound of phthalic anhydride (or ortho-phthalic acid) represented by the formula (1) is ethylene glycol at both ends of the phthalic anhydride (or ortho-phthalic acid) component. Or obtained by reacting the diol component of neopentyl glycol.

Wherein R is ethylene glycol or neopentyl glycol.

Looking at the present invention in more detail as follows.

In the present invention, the molecular structure of phthalic anhydride (or ortho-phthalic acid) is very effective compared to conventional isophthalic acid in destroying the structural regularity of the polymer backbone compared to the symmetric molecular structure of terephthalic acid constituting the usual polyethylene terephthalate. Focusing on having, phthalic anhydride was used together with terephthalic acid as the acid component. Furthermore, in order to improve color defects occurring in the polycondensation process of the copolyester using phthalic anhydride, various factors have been examined, and as a result, in the condensation polymerization process, instead of using phthalic anhydride (or ortho-phthalic acid) directly, The reaction mechanism is prepared by using an ester-forming derivative of phthalic anhydride (or ortho-phthalic acid) represented by the following formula (1) obtained by reacting ethylene glycol or neopentyl glycol at the end of the phthalic acid (ortho-phthalic acid) component. By simplifying, the color of the copolyester was improved, and the adhesiveness and the feel were expressed for the fiber, and the copolyester-based binder fiber with the high glass transition temperature, which significantly reduced the occurrence of fusion yarn, could be obtained.

Formula 1

Wherein R is ethylene glycol or neopentyl glycol.

According to the present invention, the heat-adhesive copolyester-based binder fiber is ester formed of 70 to 90 mol% of terephthalic acid and / or its ester-forming derivative and phthalic anhydride (or ortho-phthalic acid) represented by the formula (1) Acid component of dicarboxylic acid consisting of 10 to 30 mole percent phthalic anhydride (or ortho-phthalic acid) in the derivative, and diol component consisting of 75 to 90 mole percent ethylene glycol and 10 to 25 mole percent neopentyl glycol It is prepared by condensation polymerization.

At this time, the content of ethylene glycol or neopentyl glycol constituting the ester-forming derivative compound of phthalic anhydride (or ortho-phthalic acid) represented by the formula (1) is finally provided in the diol component of the heat-adhesive copolyester polyester The content of neopentyl glycol is 10 to 25 mol%.

Ester-forming derivatives of phthalic anhydride (or ortho-phthalic acid) obtained by reacting ethylene glycol and neopentyl glycol at the end of the phthalic anhydride (ortho-phthalic acid) component according to the present invention are characterized by structural regularity of the polymer main chain. It is more effective than conventional isophthalic acid in breaking down to lower the melting temperature of the polymer and destroying crystallinity. In case of using phthalic anhydride (or ortho-phthalic acid) directly, it is usually 1mmHg. Heating to 260 ° C to 290 ° C under the following reduced pressure), and phthalic anhydride (or ortho-phthalic acid) participate in the reaction with a ring-opening reaction, a direct esterification reaction, and a transesterification reaction, causing thermal decomposition and no reaction. It prevents the formation of colored material and expresses excellent color.

When the content of phthalic anhydride (or ortho-phthalic acid) in the ester-forming derivative compound of phthalic anhydride (or ortho-phthalic acid) represented by Chemical Formula 1 is less than 10 mol% in the acid component, crystallization is performed on the prepared copolyester. Is formed and the softening temperature is increased, which causes a rise in processing temperature, and when the content exceeds 30 mol% of the acid component, the softening temperature lowering effect is weakened and causes a decrease in physical properties and color defects of the copolyester. .

On the other hand, as the diol constituting the copolyester by the polycondensation reaction, ethylene glycol and neopentyl glycol are mixed and used in the preparation of an ester-forming derivative compound of phthalic anhydride (or ortho-phthalic acid) represented by the formula (1). Finally, the diol component of the heat-adhesive copolyester to be provided is composed of 10 to 25 mole% of neopentyl glycol based on the moles of dicarboxylic acid units. At this time, if the content of neopentyl glycol exceeds 25 mol% softening start temperature of the copolyester is too low below 50 ℃ causes a problem in using as a wick for clothes.

It is possible to reduce the reaction temperature and shorten the reaction time during the polycondensation of the adhesive to the copolyester reaction of the present invention to improve color defects and at the same time use a multifunctional component that improves workability during spinning and stretching into fibrous form. It is also preferred that the polyfunctional component to be added is polycarboxylic acid, polyol, polyoxycarboxylic acid, trimellitic acid, trimesic acid, 3,3 ', 4,4'-benzophenonetetracarboxylic acid, 1,2, 3,4, -butanetetracarboxylic acid and derivatives thereof, such as acid esters and acid anhydrides, glycerin, pentaerythritol and sorbitol, and the amount of 10 to 3,000 ppm can be added for each copolyester component, Preferably it is 50-1,000 ppm. At this time, if the amount of the polyfunctional component is less than 10ppm, it is insufficient to serve as a desired crosslinking agent, and if the amount of the polyfunctional component is more than 3,000ppm, on the contrary, a sharp crosslinking phenomenon causes problems during polymerization, spinning and stretching. Cause.

The heat adhesive copolyester according to the invention can be used as part or all of the binder fibers. In-situ spinning or composite spinning can be used to prepare binder fibers from the copolyester of the present invention. That is, the binder fiber may be manufactured by spinning with the copolyester single component of the present invention, or by composite spinning with other fiber-forming components. The composite spinning can take the form of a side-by-side form, and a sheath-core form comprising the copolyester of the present invention as a sheath component.

Hereinafter, the present invention will be described in more detail with reference to the following examples, but the scope of the present invention is not limited to the following examples.

In addition, the evaluation item shown in the Example and the comparative example was measured as follows.

1. Melting point, glass transition temperature and softening behavior

Measured using a differential differential scanning calorimeter (Perkin Elmer, DSC-7) and using a dynamic thermal characteristic meter (Perkin Elmer, DMA-7; TMA mode) when there is no heat absorption peak, ie, no melting point. Softening behavior was measured.

2. Intrinsic Viscosity (IV)

The copolyester was dissolved in phenol / tetrachloroethane (weight ratio 50/50) to form a 0.5 wt% solution, and then measured at 35 ° C. with a Uberod viscometer.

3. Adhesion Measurement

A cis-core polyester binder fiber having monodenia of 4 denia was prepared using the prepared copolyester chip as a cis component and a general polyethylene terephthalate chip as a core component. These fibers were cut into 51 mm of fiber length and given together with mechanical crimps. Then, in a roller carding machine, a non-woven fabric of 2 g / 100 cm 2 was mixed by carding at a weight ratio of 50:50 with conventional polyethylene terephthalate, and heat-bonded for 1 minute at a temperature of 165 ° C., and then the adhesive force was measured by the method of ASTM D1424. .

4. Touch

Relative evaluation was made by touching.

◎ (excellent), 0 (good), △ (normal), × (bad)

Example 1

Ester-forming derivative compound of phthalic anhydride represented by Formula 1 in the ratio shown in Table 1 in the ester reactor containing polyethylene terephthalate oligomer obtained by directly esterifying terephthalic acid and ethylene glycol (hereinafter referred to as 'PA-Es' Abbreviated) 70% by mole of terephthalic acid and 30% by mole of phthalic anhydride in PA-Es, and then transesterification at about 245 ° C. for 1 hour in the presence of manganese acetate, a common transesterification catalyst. Completed. The added PA-Es was used after reacting the molar ratio of phthalic anhydride, ethylene glycol, neopentylglycol to 1: 1.67: 0.33 as described in Table 1 below at a reaction temperature of 150 ° C to 200 ° C to 95%. . After adding the antimony trioxide which is a normal condensation polymerization catalyst here, it heated up to about 280 degreeC, carrying out pressure reduction so that a final vacuum might be 1 mmHg or less, and the polycondensation reaction was performed. As shown in Table 2, the physical properties of the obtained copolyester were not measured at the melting point, and only the softening behavior was measured. In addition, the adhesive strength and the touch after adhesion measured by the above-described adhesive force measuring method were good, and the results are shown in Table 2 below.

Examples 2-4 and Comparative Examples 1-5

As shown in Table 1 below, the physical properties of the copolymerized polyesters of terephthalic acid, PA-Es, phthalic anhydride, isophthalic acid, neopentylglycol, trimellitic acid, and measured adhesive strength and haptic feeling after adhesion are shown in Table 2 below.

Copolymerization composition TPA (mol%) PA-Es PA (mol%) IPA (mol%) NPG (mol%) TMA (ppm) mole% PA: EG: NPG reaction ratio Example One 70 30 1.0: 1.67: 0.33 ― ― ― 1,000 2 70 30 1.0: 2.0: 0.0 ― ― ― 1,000 3 75 25 1.0: 1.50: 0.50 ― ― ― 1,000 4 80 20 1.0: 1.0: 1.0 ― ― ― 1,000 Comparative example One 82 18 1.0: 2.0: 0.0 ― ― ― ― 2 45 55 1.0: 2.0: 0.0 ― ― ― ― 3 70 ― 30 ― ― ― 4 85 ― 15 ― 35 ― 5 80 ― 20 5 ―

* TPA: terephthalic acid, PA-Es; Ester-forming derivative compounds of phthalic anhydride,

PA; Phthalic anhydride, IPA; Isophthalic acid, NPG; Neopentylglycol, TMA; Trimellitic acid

Ultimate viscosity (IV) Color (b) Melting Point (℃) Glass transition temperature (℃) Softening Temperature (℃) Adhesive force (kg) touch Example One 0.61 2.0 ― 68.7 101 2.5 ◎ 2 0.60 2.5 ― 65.2 111 2.4 ◎ 3 0.60 1.7 ― 69.2 110 2.2 0 4 0.60 1.5 ― 70.3 104 2.1 0 Comparative example One 0.60 3.4 2.1 68.5 ― 0.5 × 2 0.58 15.0 ― 57.4 92 1.7 △ 3 0.60 12.0 ― 58.1 110 2.4 0 4 0.60 3.2 ― 68.8 50 1.2 △ 5 0.59 2.0 186 70.8 ― 0.9 ×

* Feel: ◎ (excellent), 0 (good), △ (normal), × (bad)

As can be seen from the results of Table 2, in the copolymerized polyesters of Examples 1 to 4 and the copolymerized polyesters of Comparative Examples 2, 3, and 4, melting points were not measured, and only softening behaviors characteristic of amorphous polymers appeared. Of these, Examples 1 to 4 according to the present invention are excellent in color, adhesion, and feel, and the occurrence of fused yarn is reduced due to the high glass transition temperature, while the amount of ester-forming derivatives of phthalic anhydride is used. In the case of Comparative Example 2 exceeding the scope of the invention, the color and touch were poor, and the glass transition temperature was low, and when phthalic anhydride was used, the color was poor. In the case of Comparative Example 3, phthalic anhydride is within the scope of the present invention, but the color is poor because it does not take the method of using an ester-forming derivative compound, and it does not contain neopentyl glycol, and thus the glass transition temperature is low, so that fusion is likely to occur. There is this. In the case of Comparative Example 4, the content of neopentyl glycol exceeds the range of the present invention. In this case, the glass transition temperature is high enough, there is no fusion welding problem, but the softening temperature is low, resulting in poor adhesion and touch. Also, in the case of Comparative Example 1 in which the amount of the ester-forming derivative compound of phthalic anhydride was less than the scope of the present invention, melting point appeared, adhesion and touch were very poor, and melting point was measured in Comparative Example 5 using isophthalic acid. Adhesion and touch were very poor.

As described above, the binder fiber according to the present invention has no melting point and shows softening behavior at an adhesive processing temperature in the range of 110 ° C. to 180 ° C. as compared with the binder prepared by the conventional method, and has excellent adhesion and soft touch after adhesion. In addition, there is an advantage of excellent color, high glass transition temperature, and can be particularly effective in the production of polyester-based nonwoven fabric or padding products.

Claims (6)

(a) from 10 to 30 mole% of phthalic anhydride in an ester-forming derivative of 70 to 90 mole% of terephthalic acid and / or its ester-forming derivative thereof and phthalic anhydride (or ortho-phthalic acid) Condensation polymerization reaction of the acid component of the dicarboxylic acid constituted with (b) 75 to 90 mol% of ethylene glycol and 10 to 25 mol% of neopentyl glycol is carried out by condensation polymerization reaction, and the phthalic anhydride represented by the formula (1) (or An ester-forming derivative compound of ortho-phthalic acid) is obtained by reacting a diol component of ethylene glycol or neopentyl glycol at both ends of a phthalic anhydride (or ortho-phthalic acid) component. Method of making fibers. Formula 1 Wherein R is ethylene glycol or neopentyl glycol. delete The diol component in the ester-forming derivative compound of the phthalic anhydride (or ortho-phthalic acid) is 25 mol% or less based on the moles of dicarboxylic acid units as the diol component constituting the copolyester. It is neopentyl glycol of the manufacturing method of the heat-adhesive polyester-based binder fiber characterized by the above-mentioned. The polycarboxylic acid, polyol, polyoxycarboxylic acid, trimellitic acid, trimesic acid, 3,3 ', 4,4'-benzophenonetetracarboxylic acid, 1,2, 3,4, -butanetetracarboxylic acid, or derivatives thereof, glycerin, pentaerythritol, and a method for producing a heat-adhesive polyester-based binder fiber, characterized by further adding a multifunctional component selected from the group consisting of sorbitol. The method for producing a heat-adhesive polyester-based binder fiber according to claim 4, wherein the multifunctional component is 10 to 3,000 ppm with respect to the copolyester component. The method for producing a heat-adhesive polyester-based binder fiber according to claim 4 or 5, wherein the multifunctional component is 50 to 1,000 ppm with respect to the copolyester component.