KR20040096190A - Thermal adhesive co-polyester, preparing method thereof and binder fiber including the same - Google Patents

Abstract

PURPOSE: A thermal adhesive co-polyester polyester, its preparation method and a binder fiber containing the polyester are provided, to improve adhesive strength and the touch of adhered region. CONSTITUTION: The method comprises the step of copolymerizing a dicarbonic acid component which comprises 50-95 mol% of terephthalic acid and/or its ester derivative, and 5-50 mol% of a phthalic anhydride ester derivative represented by the formula 1; a diol component which comprises 70-100 mol% of ethylene glycol and 0-30 mol% of a diol having a boiling point below 300 deg.C; and a multifunctional component, by esterification and polycondensation, wherein R' and R'' are identical or different each other and are an ethylene glycol or a diol having a boiling point below 300 deg.C. Some of the ethylene glycol and the diol having a boiling point below 300 deg.C are added during the esterification of copolymeric polyester of the phthalic anhydride ester derivative formed through the esterification with phthalic anhydride.

Description

Thermal adhesive copolyester, preparation method thereof and binder fiber containing the same {Thermal adhesive co-polyester, preparing method etc and binder fiber including the same}

The present invention relates to a heat-adhesive copolyester, a method for preparing the same, and a binder fiber containing the same, and more particularly, an efficient ester by processing and adding a polyester modifier in the form of an ester-forming derivative during the polymerization reaction process. The heat-adhesive copolyester which not only has excellent color of the polymer finally obtained by copolymerization through exchange reaction but also shows high adhesion and excellent touch when thermally bonding the heat-adhesive fibers to each other, and a method for preparing the same It relates to a binder fiber.

Copolyesters can be used in adhesive binder fibers used in the manufacture of nonwoven products that are applicable to a variety of materials, including padding and molding.

In general, various nonwoven materials including nonwoven fabrics and padding products are carded with short fibers to laminate several carding web products in the machine direction and the semi-machine direction, and then have interfiber adhesion between fibers as an adhesive material (binder). The method is widely known.

The method of manufacturing such a nonwoven fabric can be broadly classified into two types. 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. The second method is as in the present invention. Binder fibers prepared by complex spinning of matrix fibers in a homogeneous or sheath-core type or side-by-side type having a low melting point are mixed during carding, and then subjected to heat treatment. By bonding the constituent fibers.

However, the first 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 causes the environmental pollutants caused by the solvent, Due to the low compatibility of the adhesiveness is also low and has a disadvantage of poor touch.

On the other hand, as in the present invention, the heat-adhesive adhesive which does not use a solvent has a great advantage that the adhesion is completed instantaneously by heating, and also contributes to the rationalization, personnel reduction, and speedup of the adhesion process in the field of fiber adhesion. Many are being developed and marketed.

Generally, as binders for adhesive fibers such as nonwoven fabric binders and padding products, conventional polyethylene, polypropylene, polyamides, ethylene-vinyl acetate copolymers and the like are known, but these adhesive strengths, in particular, adhesive strength to polyester-based synthetic fibers This is not enough, and it 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 high temperature dependence of melt viscosity, a decrease in adhesive strength during use, and a poor feel of the adhesive part. There are disadvantages such as yellowing phenomenon 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 fiber known to date is a method using terephthalic acid, dimethyl terephthalate, isophthalic acid, aliphatic dicarboxylic acid having 30 or less carbon atoms as aromatic dicarboxylic acid component, and diethylene glycol, tetramethylene glycol as diol component. , Neopentylglycol, polyethylene glycol, 1,4-butanediol and the like are mostly composed.

For example, Japanese Patent Application Laid-Open No. 48-96631 discloses a method for producing a low melting polyester based on dimethyl terephthalate, 1,4-butanediol and diethylene glycol, but the glass of the polyester resin used Since the transition temperature is lower than 50 ℃ shows a sharp change over time during the fiber manufacturing process has a technical disadvantage.

U.S. Patent No. 4,166,896 discloses a process for preparing unsaturated polyesters by copolymerizing unsaturated dicarboxylic acids and the like on low molecular weight polymerized depolymerized polyesters. However, the fiber according to the patent is not only economically low, but also has a disadvantage of being too high a melting point and high crystallinity for use as an adhesive.

In addition, US Pat. 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, in which case the melting point of the adhesive obtained It is too low at 45-60 degreeC, and there exists a problem that it is difficult to use with a wick for clothing.

Therefore, in the present invention, extensive research has been conducted to solve the problems described above. Instead of using phthalic anhydride directly during copolymerization polyester polymerization, ethylene glycol and / or dicarboxylic acid are easily added to the end of the phthalic anhydride. Using the phthalic anhydride ester-forming derivative obtained by reacting various diols showing one esterification reactivity, it was possible to improve the scattering loss and color defect problems of the copolymerization raw materials generated in the polycondensation process of the copolyester. Completed on the basis of

Therefore, the object of the present invention is not only excellent adhesion to the polyester to be adhered and the touch of the adhesion site after adhesion, but also to suppress the loss of the copolymerization raw material scattered during the polymerization production of the product to the maximum, and good color It is to provide a method for producing a heat-adhesive copolyester suitable for producing a high quality polyester nonwoven fabric.

Another object of the present invention is to provide a heat-adhesive copolyester prepared according to the above method.

Still another object of the present invention is to provide a high quality heat adhesive copolyester-based binder fiber containing the heat-adhesive co-polyester.

The method for producing a heat-adhesive copolyester according to the present invention for achieving the above object is (a) 50 to 95 mol% of terephthalic acid and / or its ester-forming derivative, and phthalic anhydride ester-forming formula represented by the following formula (1) A dicarboxylic acid component consisting of 5-50 mol% of a derivative, (b) 70-100 mol% of ethylene glycol and a diol component consisting of 0-30 mol% of a diol having a boiling point of less than 300 ° C, and (c) a polyfunctional component It is prepared by copolymerization through an esterification reaction and a polycondensation reaction, wherein a part of the ethylene glycol and a diol having a boiling point of less than 300 ° C are in the form of a phthalic anhydride ester-forming derivative through an esterification reaction with phthalic anhydride. It is characterized in that it is added during the esterification reaction of the copolyester:

Wherein R 'and R "are the same or different from each other ethylene glycol or diols having a boiling point below 300 ° C.

The heat-adhesive copolyester according to the present invention for achieving the above another object is prepared according to the above method.

The heat-adhesive copolyester-based binder fiber according to the present invention for achieving the above another object is composed by containing at least a part of the heat-adhesive copolyester.

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

As described above, in the present invention, the color of the polymer is excellent, the adhesive strength with the polyester to be adhered is excellent, and the touch of the adhesive site after the adhesion is also good, the heat-adhesive copolyester, a method for preparing the binder and the same Fiber is provided.

The present inventors have focused on the fact that the molecular structure of phthalic anhydride has a very effective function 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 (polymer Lowers the melting temperature and destroys crystallinity), the adhesion processing temperature in the range of 110 to 210 ° C, and the structure and physical properties of the copolyester that can satisfy the feel of the bonding site. The copolyester of the specific composition synthesized from the dicarboxylic acid component consisting of phthalic acid, the diol component consisting of various diols showing easy esterification reactivity with ethylene glycol and dicarboxylic acid was made to exhibit excellent fiber adhesion function.

According to the prior art, when the ester derivative is synthesized using terephthalic acid and isophthalic acid as an acid component, a cyclic oligomer compound having a polymerization degree of 2 is generated. Since its melting point is about 325 ° C., it is higher than the spinning temperature of general polyester fiber and thus it is packed during the spinning process. There was a tendency to shorten the exchange cycle and lower productivity.

On the other hand, when the resin is prepared using the acid component as terephthalic acid and phthalic anhydride, low-molecular-weight cyclic compounds are also generated, but the melting point of the low-molecular-weight cyclic compounds is about 198 ° C., which hardly affects the pack life during the spinning process. Productivity can be improved. In addition, unlike the dicarboxylic acid component of the existing isophthalic acid in the meta position around the benzene ring, the dicarboxylic acid component of the phthalic anhydride is present in the ortho position around the benzene ring, so the crystal structure of the existing polyester It also has the advantage of increasing the melt flowability during thermal bonding by further increasing the irregularity of.

However, polyester binders produced using phthalic anhydride are also not the best ideal levels and there is plenty of room for improvement. That is, the copolyester synthesized using phthalic anhydride is usually melted or melted at a temperature of 330 ° C. or higher in terephthalic acid and isophthalic acid under the same conditions as the polyethylene terephthalate polycondensation step of heating to 270 to 290 ° C. under a reduced pressure of 1 mmHg or less. In contrast to the sublimation, phthalic anhydride has a low melting point of 130 to 135 ° C and a boiling point of 285 to 295 ° C, which is then scattered together with the diol component having a boiling point of less than 300 ° C. There is a disadvantage that less residual amount is detected in the obtained copolymerized polyester polymer composition.

In addition, there is a problem in that the color of the finally obtained polymer is poor, which is a state in which the ring-opening reaction, the direct esterification reaction, and the transesterification reaction of the phthalic anhydride introduced in the composition of the reaction system are mixed at high temperature and high vacuum polymerization conditions. Participation in the furnace reaction causes thermal decomposition and side reactions to be produced to produce colored material.

In order to solve the above-mentioned problems, in the present invention, the molecular weight of the compound obtained by using the ester-forming derivative of phthalic anhydride represented by the following formula (1) is increased, and the diol component having a boiling point of less than 300 ° C. and phthalic anhydride is added alone. In addition to reducing the scattering during the condensation polymerization process, the reaction mechanism can be simplified to improve the color of the obtained copolyester.

Formula 1

Wherein R 'and R "are the same or different from each other ethylene glycol or diols having a boiling point below 300 ° C.

Therefore, the heat-adhesive copolyester according to the present invention is (a) 50 to 95 mol% of terephthalic acid and / or its ester forming derivatives, and 5 to 50 mol% of the phthalic anhydride ester forming derivatives represented by the general formula (1). Esterification and condensation polymerization reaction of the dicarboxylic acid component (b) consisting of 70-100 mol% of ethylene glycol and 0-30 mol% of diol having a boiling point of less than 300 ° C, and (c) the polyfunctional component. It is prepared by copolymerization through.

The dicarboxylic acid component of the copolyester according to the present invention is composed of 50 to 95 mol% of terephthalic acid and / or its ester forming derivative, and phthalic anhydride ester forming derivative represented by the formula (1). When the content ratio of the dicarboxylic acid component of the copolyester is out of the above range, the softening temperature, the adhesion performance, and the color of the obtained polymer cannot be satisfied. That is, if the content of the phthalic anhydride ester-forming derivative of the formula (1) is less than 5 mol%, it causes a rise in the adhesion processing temperature of the prepared copolymerized polyester, and if it exceeds 50 mol%, the softening temperature lowering effect becomes weak while copolymerizing. It becomes the cause of the fall of the physical property of a polyester and a color defect.

On the other hand, the diol component of the copolymerized polyester according to the present invention is composed of 70 to 100 mol% of ethylene glycol and 0 to 30 mol% of diol having a boiling point of less than 300 ℃, a part of the ethylene glycol and the boiling point of less than 300 ℃ The diol having is introduced in the esterification reaction of the copolyester in the form of a phthalic anhydride ester-forming derivative via esterification with phthalic anhydride.

More specifically, as the diol component according to the present invention, ethylene glycol is used alone, or a diol component having a boiling point of less than 300 ° C. and ethylene glycol optionally added in the preparation of the phthalic anhydride ester-forming derivative of Chemical Formula 1 above. This mixture can be used. That is, diols having a boiling point of less than 300 ° C. and some ethylene glycols are added during the preparation of the phthalic anhydride ester forming derivative and added during the esterification reaction of the copolyester in the form of the phthalic anhydride ester forming derivative, and the remaining ethylene glycol is added to the above. It is added directly during the esterification reaction of the copolyester.

At this time, the content of the diol having a boiling point of less than 300 ℃ to be added in the form of the ester-forming derivative of phthalic anhydride of the formula (1) is 0 to 30 mol% of the diol component of the finally provided thermal adhesive copolyester When the content of the diol is more than 30 mol%, the softening temperature lowering effect is weakened, which causes a decrease in physical properties and color defects of the copolyester.

Diols having a boiling point of less than 300 ° C used in the present invention include diethylene glycol, neopentyl glycol, 1,4-cyclohexanedimethanol, 1,4-butanediol, 1,3-propanediol and the like.

As the multifunctional component used in the present invention, trimethylolpropane, 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, sorbitol and the like.

In this case, the amount of the polyfunctional component used is preferably 10 to 10,000 ppm, preferably 50 to 3,000 ppm with respect to the copolyester, and when the amount of the multifunctional component is less than 10 ppm, it is insufficient to serve as a desired crosslinking agent. On the other hand, if the content exceeds 10,000 ppm, a problem occurs during polymerization, spinning, and stretching due to rapid crosslinking. That is, by using the polyfunctional component within the above-described range, it is possible to reduce the reaction temperature and shorten the reaction time during the polycondensation polymerization of the heat-adhesive polyester of the present invention, to improve color defects and to spin and stretch the fiber. Workability can be improved at the time.

The heat-adhesive copolyester of the present invention prepared as described above may 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 the copolyester of the present invention as a single component or by complex spinning with other fiber-forming components. The form of the fiber by the composite spinning can also be in the form of a side-by-side, or in the form of a sheath-core having the copolyester of the present invention as a sheath component.

Preferably, the heat-adhesive copolyester-based binder fiber according to the present invention exhibits softening behavior at an adhesive processing temperature in the range of 110 to 210 ° C., has excellent adhesive strength, soft touch, and excellent color. Thereby, in particular, it can be effectively applied to the production of products such as polyester nonwoven or padding, molding.

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

The measurement of the evaluation item shown to the following Example and the comparative example was as follows.

1. Measurement of copolymer composition and evaluation of residual amount in polymer composition

The copolymerization composition of the copolyester was measured by dissolving the copolyester in trifluoroacetic acid using a proton nuclear magnetic resonance apparatus ( ¹ H NMR, model name DRX-300) manufactured by Bruker. At this time, the residual amount of phthalic anhydride and diol component added to the copolyester was evaluated as follows.

Residual amount (%) = amount of additive detection in the polymer (mol%) / polymerization input (mol%) x 100

2. Melting point and softening behavior

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

3. Ultimate Viscosity (IV)

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

4. Adhesion Measurement

A cis-core polyester binder fiber having a 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 mechanical crimps together. 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 a conventional polyethylene terephthalate, and thermally bonded at 190 ° C. for 1 minute, and then the adhesive force was measured by the method of ASTM D1424. .

Hereinafter, the present invention will be specifically described based on Examples and Comparative Examples.

Example 1

According to the composition ratio (mol%) shown in Table 1 below in the ester reactor containing polyethylene terephthalate oligomer obtained by direct esterification of terephthalic acid and ethylene glycol, the dicarboxylic acid component of the copolyester was 85 mol% of terephthalic acid and PA- Ethyl phthalic anhydride derivative (hereinafter referred to as PA-Es) represented by Chemical Formula 1 was added so as to have a ratio of 15 mol% of Es, and 1,000 ppm of trimethylolpropane was added thereto, followed by 1 at a reaction temperature of 245 ° C. The transesterification reaction was completed for a time.

Here, the PA-Es is phthalic anhydride, ethylene glycol and 1,4-cyclone such that the content of 1,4-cyclohexanedimethanol in the diol component of the copolyester is 15 mol% according to the composition ratio shown in Table 1 below. The molar ratio of nucleic acid dimethanol was 1.0: 1.0: 1.0, which was prepared separately by reacting the reaction rate to 95% at a reaction temperature of 150 to 200 DEG C, and then added during the transesterification reaction.

After the transesterification reaction was completed, the anticondensation reaction was carried out by adding an antimony trioxide, which is a common condensation polymerization catalyst, and raising the temperature to 280 ° C while reducing the final vacuum degree to 1 mmHg or less. The residual amount (%) and the physical properties of phthalic anhydride and 1,4-cyclonucleic acid dimethanol in the copolyester obtained therefrom were measured and the results are shown in Table 2 below. The adhesive force measured according to the adhesive force measuring method described above was good.

[Examples 2 to 4 and Comparative Examples 1 to 4]

As shown in Table 1, it was carried out in the same manner as in Example 1 except for changing the copolymer composition ratio of terephthalic acid, PA-Es, phthalic anhydride, isophthalic acid, 1,4-cyclohexane dimethanol, neopentyl glycol. The residual amount (%) and the physical properties of phthalic anhydride and 1,4-cyclonucleic acid dimethanol in the copolyester obtained therefrom were measured and the results are shown in Table 2 below.

TPA content in acid components Copolymerized diols PA-Es PA IPA Dior ² TMP (mole%) Acid content (mol%) PA: EG: diol (molar ratio) Diol Component Polymerization Diol Content ₁ (mol%) (mole%) (mole%) (mole%) (ppm) One 85 CHDM 15 1.0: 1.0: 1.0 15 - - - 1,000 room 2 70 - 30 1.0: 2.0: 0.0 0 - - - 1,000 city 3 75 DEG 25 1.0: 1.5: 0.5 12.5 - - - 1,000 Yes 4 80 NPG 20 1.0: 1.0: 1.0 20 - - - 1,000 One 45 - 55 1.0: 2.0: 0.0 0 - - - - ratio 2 70 - - - - 30 - - - School 3 85 CHDM - - - 15 - 16 - Yes 4 80 NPG - - - - 20 10 -

¹ Content of diol added in the form of phthalic anhydride ester-forming derivative during esterification of copolyester among all diol components

² Content of diol directly added during esterification of copolyester among all diol components

* TPA: terephthalic acid, CHDM: 1,4-cyclohexanedimethanol, DEG: diethylene glycol, NPG: neopentyl glycol, PA-Es: ester-forming derivative of phthalic anhydride, PA: phthalic anhydride, EG: ethylene glycol, IPA: isophthalic acid, TMP: trimethylolpropane

IV Survival rate (%) color Melting point Softening temperature Adhesion PA, IPA Dior (b is) (℃) (℃) (kg) One 0.59 96.3 95.3 2.5 171 2.5 room 2 0.60 95.5 - 3.5 - 120 2.4 city 3 0.60 95.7 101.2 2.3 - 113 2.3 Yes 4 0.60 95.9 93.9 4.5 - 108 2.2 One 0.58 93.0 - 15.0 - 92 2.0 ratio 2 0.59 90.5 - 9.8 - 125 2.2 School 3 0.60 91.8 87.8 6.1 175 - 2.2 Yes 4 0.59 97.1 71.0 2.0 182 - 1.3

As can be seen from the results of Table 2, in Examples 1 to 4 according to the present invention, diethylene glycol is excellent in color and adhesive strength and is a diol component having a boiling point of less than 300 ° C. and phthalic anhydride added to the copolyester. Comparative Example 1 in which the residual amount of neopentyl glycol and 1,4-cyclohexanedimethanol showed a high value, while the amount of the ester-forming derivative of phthalic anhydride exceeded the scope of the present invention and the polyfunctional component was not added. In the case of Comparative Examples 2 and 3, in which phthalic anhydride and 1,4-cyclohexanedimethanol were used directly and no polyfunctional component was added, color was poor. In addition, in Comparative Examples 2 and 3 in which phthalic anhydride and 1,4-cyclohexanedimethanol were used directly, the residual amount of phthalic anhydride and diol component added to the copolyester was also detected low. In Comparative Example 4 in which isophthalic acid and neopentyl glycol were directly used, the adhesion was poor, and the residual amount of neopentyl glycol was also detected low.

As described above, according to the present invention, the structure of phthalic anhydride constituting the ester-forming derivative of phthalic anhydride used in the present invention is dicarboxylic acid in the ortho position, compared to terephthalic acid having dicarboxylic acid in the para position of the benzene ring. It is very effective in destroying the structural regularity of the polyester polymer backbone due to the fact that it has a boiling point of less than 300 DEG C input during the copolymerization process by using it in the polymerization process in the form of an ester-forming derivative instead of directly using phthalic anhydride. It is possible to achieve economical effect by suppressing the scattering with the diol component as much as possible, and to prepare a heat-adhesive copolyester having excellent color of the finally obtained polymer with an efficient transesterification reaction and a binder fiber containing the same. Make it possible.

Claims (6)

(a) a dicarboxylic acid component consisting of 50 to 95 mol% of terephthalic acid and / or its ester forming derivative, and 5 to 50 mol% of an phthalic anhydride ester forming derivative represented by the following formula (1), (b) a diol component consisting of 70-100 mol% of ethylene glycol and 0-30 mol% of diol having a boiling point of less than 300 ° C, and (c) is prepared by copolymerizing the polyfunctional component through an esterification reaction and a polycondensation reaction, Here, a part of the ethylene glycol and the diol having a boiling point of less than 300 ℃ is introduced during the esterification reaction of the copolyester in the form of a phthalic anhydride ester-forming derivative through the esterification reaction with phthalic anhydride. Process for preparing heat adhesive copolyester: Formula 1 Wherein R 'and R "are the same or different from each other ethylene glycol or diols having a boiling point below 300 ° C. According to claim 1, wherein the diol having a boiling point of less than 300 ℃ 1 from the group consisting of 1,4-cyclohexane dimethanol, neopentyl glycol, diethylene glycol, 1,4-butanediol and 1,3-propanediol And at least one species is selected. The method of claim 1, wherein the multifunctional component is trimethylolpropane, trimellitic acid, trimesic acid, 3,3 ', 4,4'-benzophenonetetracarboxylic acid, 1,2,3,4-butanetetracar At least one selected from the group consisting of a main acid and derivatives thereof, glycerin, pentaerythritol, and sorbitol. The method of claim 1 wherein the multifunctional component is added in an amount of 10 to 10,000 ppm relative to the copolyester. Heat-adhesive copolyester prepared according to the method of any one of claims 1 to 4. A heat-adhesive co-polyester-based binder fiber containing at least part of the heat-adhesive co-polyester according to claim 5.