KR101699342B1 - Method for preparing Improved heat adhesive Polyester and Polyester Binder Fiber Using Same - Google Patents

Abstract

The present invention relates to a process for the preparation of terephthalic acid or an ester forming derivative thereof and an acidic component comprising maleic anhydride (MA) or acid component consisting of terephthalic acid and isophthalic acid or an ester forming derivative thereof and maleic anhydride (MA), ethylene glycol or ethylene glycol The present invention relates to a method for producing a copolymerized polyester for a binder having improved thermal adhesiveness during the esterification reaction, and a method for producing the polyester binder conjugated fiber using the same, wherein the diol having a boiling point is synthesized from a copolymerized polyester as a diol component, will be.

Description

TECHNICAL FIELD [0001] The present invention relates to a method for producing a copolymerized polyester for a binder having improved thermal adhesiveness and a polyester binder composite fiber using the same,

The present invention relates to a method for producing a copolymerized polyester for a binder having improved thermal adhesiveness and a polyester binder conjugate fiber using the same, and a binder having an excellent thermal adhesive strength and having no adhesion during the process, And a polyester binder conjugated fiber using the same.

Polyester has excellent mechanical properties, heat resistance and chemical resistance, and is used in fiber and engineering plastic materials. However, since it has semicrystalline properties due to its molecular structure, it has a high melting point and requires high temperature and pressure for use in binder applications. There are a lot of difficulties on the board.

The thermally fusible binder fibers used to bond the filaments or staple fibers constituting the web or sheet of the nonwoven fabric should have a glass transition temperature close to that of a regular polyethylene terephthalate fiber with a heat bonding temperature of 140 to 150 ° C To do this, it is necessary to eliminate the crystal structure in the polymer and make the polymer structure into an amorphous form.

For this purpose, it is typical to copolymerize terephthalic acid with isophthalic acid as a copolymerization component in the synthesis of polyester resin, wherein isophthalic acid is added in an amount of 20 to 45 mol% based on the ester molar amount, and the polyester resin thus synthesized is amorphous And has a final melting point ranging from 145 to 180 ° C and can be used as a polyester fiber for a binder. However, in the polyester resin for a binder using isophthalic acid, a cyclic compound having a degree of polymerization of 2 to 3 is formed when synthesized, and the melting point of the cyclic compound is about 325 DEG C and is not melted at the polyester spinning temperature, Thereby shortening the cycle of exchanging the pack, and the price of isophthalic acid is usually high. In addition, diethylene glycol can be used as a copolymerization material. Polyester resin synthesized by copolymerization of diethylene glycol has a high glass transition temperature, which is problematic in the stretching process, product fusing between fibers during product transportation or dropping, Strength is low.

U.S. Patent No. 4,129,675 discloses a low melting point polyester binder based on terephthalic acid and isophthalic acid, but it is uneconomical because it requires a temperature of 190 ° C or more in thermal bonding.

U.S. Patent No. 4,166,896 discloses a method for producing an unsaturated polyester by copolymerizing unsaturated dicarboxylic acid or the like with a low-molecular-weight water having depolymerized polyester, but the fiber according to the patent also has low economic efficiency, There is a disadvantage that it is excessively high melting point and high crystallinity.

U.S. Patent No. 4,065,439 discloses a low melting point polyester obtained using terephthalic acid / isophthalic acid / adipic acid (or sebacic acid) and ethylene glycol / neopentyl glycol, but the melting point of the binder is 45 ° C to 60 ° C It is not only difficult to use as a garment wick but also has low dimensional stability under high temperature conditions.

On the other hand, Korean Patent Laid-Open Publication No. 2001-11548 discloses a polyester resin composition comprising a dicarboxylic acid component of terephthalic acid and a phthalic anhydride, and a diol component of ethylene glycol and diethylene glycol, which are excellent in adhesion to polyester, Although the binder for ester-based fibers is provided, the binder is complicated in the reaction mechanism by directly using anhydrous phthalic acid, and thus has a disadvantage in that the condensation polymerization temperature must be lowered in order to prevent the problem of poor color of the copolymer polyester. In addition, such a low temperature polycondensation reaction has a problem in that the productivity is lowered.

That is, the copolyester synthesized using the phthalic anhydride of Korean Patent Laid-Open No. 2001-11548 is obtained under the same condition as the polyethylene terephthalate polycondensation step in which the copolymer polyester is heated to 270 ° C to 290 ° C under a reduced pressure of 1 mmHg or lower There is a disadvantage that the color of the polymer becomes poor. This is because the phthalic anhydride charged in the composition of the reaction system under the high temperature and high vacuum polymerization conditions participates in the reaction in the state where the ring-opening reaction, the direct esterification reaction and the transesterification reaction are mixed in the reaction process to generate pyrolysis and side reactions, Because.

The present invention has been made to solve the problems of the prior art as described above and provides a method for producing a copolymerized polyester for a binder having an excellent thermal adhesion at a low process temperature of 140 to 160 ° C and an adhesive property at a high temperature, .

Further, it is possible to polymerize an amorphous polyester for binder, which is resistant to thermal decomposition by using maleic anhydride (MA), and the rate of change of the fiber due to a low glass transition temperature is delayed in the drawing process after spinning of the binder fiber It is an object of the present invention to provide a polyester binder fiber with reduced productivity due to occurrence of adhesion between adjacent fibers in a drawing process.

The present invention relates to a terephthalic acid or an ester-forming derivative thereof, an acidic component comprising maleic anhydride (MA) of the following formula (1) or maleic anhydride (MA) of terephthalic acid and isophthalic acid or ester- Characterized in that ethylene glycol or ethylene glycol and a diol having a boiling point of less than 300 ° C. are synthesized as a copolymerized polyester as a diol component and the maleic anhydride (MA) is introduced during the esterification reaction, A method for producing a polyester is provided.

[Chemical Formula 1]

The maleic anhydride (MA) of the acid component is added in an amount of 1 to 30 mol% based on the molar amount of the copolymer polyester.

The diol component having a boiling point of less than 300 ° C. is added in an amount of 1 to 30 mol% based on the molar amount of the copolymerizable polyester. The method for producing a copolymerized polyester for a binder having improved thermal adhesiveness, to provide.

The maleic anhydride (MA) is added when the reaction rate of the esterification reaction is 92 to 98%. The present invention also provides a method for producing a copolymerized polyester for a binder having improved thermal adhesiveness.

The diol having a boiling point of less than 300 ° C may be at least one selected from the group consisting of 1,4-cyclohexane dimethanol, neopentyl glycol, diethylene glycol, 1,4-butanediol, and 1,3- The present invention also provides a method for producing a copolymerized polyester for a binder having improved thermal adhesiveness.

Further, there is provided a copolymer polyester for a binder, which is produced by the above-mentioned production method.

Also provided is a polyester-based binder fiber characterized by containing the above-mentioned copolymer polyester for a binder.

As described above, the copolymer polyester for binder and the polyester binder conjugate fiber using the same, which have improved thermal adhesiveness according to the present invention, are excellent in low-temperature adhesiveness and maintain the adhesive strength even at high temperatures.

In addition, the copolymer polyester for binder having improved thermal adhesiveness of the present invention has a small difference in glass transition temperature from that of ordinary polyester, so that it has an excellent effect on the bonding strength and shape stability of nonwoven fabric during the production of nonwoven fabric.

Hereinafter, a preferred embodiment of the present invention will be described in detail. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted so as to avoid obscuring the subject matter of the present invention.

As used herein, the terms " about, " " substantially, " " etc. ", when used to refer to a manufacturing or material tolerance inherent in the stated sense, Accurate or absolute numbers are used to help prevent unauthorized exploitation by unauthorized intruders of the referenced disclosure.

The present invention relates to a method for producing a copolymerized polyester for binder having improved thermal adhesiveness, which is produced through an esterification process in which an oligomer is produced by esterification using an acid component and a diol component, and oligomers produced by a condensation polymerization process.

The acid component may be terephthalic acid or an ester forming derivative thereof, maleic anhydride (MA) represented by the following formula (1), terephthalic acid or isophthalic acid or an ester forming derivative thereof and maleic anhydride (MA) represented by the following formula (1).

[Chemical Formula 1]

The diol component may use a diol component such as ethylene glycol or ethylene glycol and a diol having a boiling point of less than 300 占 폚.

The maleic anhydride (MA) may preferably be copolymerized during the esterification reaction.

As described above, in the present invention, when maleic anhydride (MA) is used, when polyester is produced by using maleic anhydride (MA), it has an aromatic ring structure to widen the free space between main chains and to react with ester and the diol component And has a higher reactivity than that of isophthalic acid due to its aromatic structure.

Therefore, it functions very effectively in lowering the melting temperature of the polyester and destroying the crystallinity.

On the other hand, the lower the effect of lowering the melting temperature compared with the amount of the injection, the less effective the lowering effect of the glass transition temperature. In the case of the maleic anhydride (MA), the effect of lowering the melting temperature is large, And a glass transition temperature of 65 ° C or higher is exhibited even when a high content is introduced into the amorphous polymer.

Therefore, as described above, it is preferable that the acidic maleic anhydride (MA) used in the present invention is added in the range of 1 to 30 mol% based on the molar amount of the copolymer polyester.

If the amount of the maleic anhydride (MA) is less than 1 mol%, the effect of lowering the melting temperature of the polyester may be small. If the amount of the maleic anhydride (MA) is more than 30 mol% On the contrary, when the amount is excessively increased, excessive melting point lowering may cause adverse effects such as fusion and adhesion between adjacent fibers.

The maleic anhydride (MA) is added during the esterification reaction. When the maleic anhydride (MA) is initially charged, the acidic component and the diol component affect the main chain of the molecular structure formed by the esterification reaction, . Therefore, it is desirable to add maleic anhydride (MA) when the reaction rate of the esterification reaction is 92 to 98%.

The diol having a boiling point of less than 300 캜 of the diol component lowers the melting point and the glass transition temperature of the polyester so that the amount of the diol component to be controlled should be controlled. The diol having a boiling point of less than 300 캜 of the diol component, It is preferable to be charged in the range of 1 to 30 mol%.

If the amount of the diol having a boiling point of less than 300 캜 of the diol component is less than 1 mol%, it is impossible to obtain a polyester which inhibits the melting point and the formation of the cyclic compound. When the amount exceeds 30 mol%, the glass transition temperature It may cause a problem of change of the fiber with time at the time of spinning.

The diol having a boiling point of less than 300 캜 may be selected from at least one member selected from the group consisting of 1,4-cyclohexane dimethanol, neopentyl glycol, diethylene glycol, 1,4-butanediol, and 1,3-propanediol It will be possible.

The copolymer polyester for a binder having improved thermal adhesiveness according to the present invention produced as described above has a glass transition temperature of 65 ° C or higher and has a small difference as compared with that of ordinary polyester and its copolymer at a level of 65 to 80 ° C .

When the glass transition temperature is low, the rate of change of the fiber over time in the spinning and drawing process of the binder fiber is accelerated, and the productivity is deteriorated due to the occurrence of adhesion between adjacent fibers during the process And the bonding strength and shape stability of the nonwoven fabric at high temperature may be deteriorated. However, the copolymer polyester of the present invention has an advantage of hardly causing such a problem.

The polyester-based binder fiber can be produced by using the copolymerized polyester for binder having improved thermal adhesiveness according to the present invention.

The polyester-based binder fiber may be produced in the form of a composite fiber of a sheath-core type or a silica-bead type using a general polyester and a copolymer polyester for a binder of the present invention.

When the composite fiber is produced into a sheath-core type, it is preferable that the copolymer polyester for a binder of the present invention is formed into a sheath portion and the general polyester is formed into a core portion.

As described above, the polyester-based binder fiber containing the copolymer polyester for a binder of the present invention not only enables thermal bonding between fibers even at a low process temperature, but also has excellent shape stability at a high temperature of 100 to 130 ° C after the production of the nonwoven fabric .

Hereinafter, examples of the method for producing the copolymer polyester for a binder having improved thermal adhesiveness according to the present invention are shown, but the present invention is not limited to the examples.

Examples 1 to 4

Terephthalic acid as an acid component and ethylene glycol as a diol component were fed into an esterification reaction vessel and reacted at a temperature of 258 ° C by a conventional method to obtain maleic anhydride (MA) with a reaction rate of 96% The transesterification reaction was carried out at 250 DEG C in the presence of an exchange reaction catalyst. The esterification oligomer thus obtained was charged with a conventional polycondensation catalyst, and then the polycondensation reaction was carried out by raising the temperature to 280 DEG C while gradually reducing the pressure to 0.1 mmHg.

The maleic anhydride (MA) was prepared in the same manner as in Example 1, except that the amount of the maleic anhydride (MA) was changed as shown in Table 1 based on the mole of the copolymerized polyester.

The ester reaction rate was measured by the following equation.

Ester reaction rate = [Saponification Value - Acid Value] / SN (Saponification Value) × 100

The SN value is a value indicating the amount of KOH or NaOH required to titrate COOH, and has a value of meq./g.

The Acid Value is a value indicating the oligomer terminated with COOH in the TPA + EG reaction and has a value of meq./g.

Examples 5 to 8

Diol diethylene glycol (hereinafter, referred to as 'DEG') having a boiling point of less than 300 ° C. as a diol component was prepared in the same manner as in Examples 1 to 4, and 10 mol% 5 to 8 binder copolymers were prepared.

Comparative Examples 1 to 4

Were prepared in the same manner as in Examples 1 to 4 except that isophthalic acid was added in place of maleic anhydride (MA) to prepare the copolyesters for binders of Comparative Examples 1 to 4.

Comparative Examples 5 to 8

Were prepared in the same manner as in Examples 5 to 8 except that isophthalic acid was added in place of maleic anhydride (MA) to prepare copolyesters for binders of Comparative Examples 5 to 8.

division MA (mol%) IPA (mol%) DEG (mol%) Example 1 One 0 0 Example 2 10 0 0 Example 3 30 0 0 Example 4 40 0 0 Example 5 One 0 10 Example 6 10 0 10 Example 7 30 0 10 Example 8 40 0 10 Comparative Example 1 0 One 0 Comparative Example 2 0 10 0 Comparative Example 3 0 30 0 Comparative Example 4 0 40 0 Comparative Example 5 0 One 10 Comparative Example 6 0 10 10 Comparative Example 7 0 30 10 Comparative Example 8 0 40 10

MA: maleic anhydride, IPA: isophthalic acid, DEG: diethylene glycol

The physical properties of the copolyester for binders prepared in Examples 1 to 8 and Comparative Examples 1 to 8 were measured and shown in Table 2.

1. Measurement of melting point (Tm) / glass transition temperature (Tg) and softening behavior (SP)

(Perkin Elmer, DMA-7; TMA mode) when there is no heat absorption peak, that is, when no melting point is present, by using a thermal differential scanning calorimeter (Perkin Elmer, DSC-7) The softening behavior was measured.

3. Intrinsic viscosity (IV) measurement

The copolymerized polyester was dissolved in phenol / tetrachloroethane (weight ratio 50/50) to make a 0.5 wt% solution, and then measured at 35 캜 with a Ubbelohde viscometer.

4. Adhesion at room temperature

The heat-sealable nonwoven fabric thus prepared was fixed at a density of 2 g / 100 cm 2, and the low temperature bonding strength was measured at a temperature of 75 ° C. by the method of ASTM D1424.

division IV Tg Tm SP Adhesion at room temperature dl / g ℃ kg Example 1 0.643 78.9 245.7 - - Example 2 0.642 73.7 204.8 - - Example 3 0.647 69.7 - 128 78 Example 4 0.641 62.1 - 125 73 Example 5 0.643 68.3 230.1 - - Example 6 0.649 63.6 190.4 - - Example 7 0.647 58.8 - 118 65 Example 8 0.640 54.1 - 114 67 Comparative Example 1 0.640 78.8 247.2 - - Comparative Example 2 0.644 74.2 232.2 - - Comparative Example 3 0.642 60.1 208.6 - - Comparative Example 4 0.643 58.4 - 121 62 Comparative Example 5 0.641 68.7 233.6 - - Comparative Example 6 0.646 60.2 191.7 - - Comparative Example 7 0.643 57.8 - 121 56 Comparative Example 8 0.643 55.3 - 122 58

As shown in Table 2, intrinsic viscosities are similar to each other in Examples 1 to 4 using maleic anhydride (MA) and Comparative Examples 1 to 4 using isophthalic acid, and Examples 1 to 4 are comparative examples 1 to 4 and the glass transition temperatures of Examples 1 to 4 are mostly at least 65 ° C.

Also, as can be seen from the results of the room temperature adhesion, Examples 3 to 4, in which maleic anhydride (MA) was used in a certain amount, showed better adhesive strength than Comparative Examples.

In Examples 5 to 8 and Comparative Examples 5 to 8 using diethylene glycol, the drop in the glass transition temperature was large, indicating that the adhesive strength at room temperature was relatively low. In this case, in Examples 5 to 8 using maleic anhydride (MA) 8 have relatively higher adhesion strength than Comparative Examples 5 to 8 using isophthalic acid.

Therefore, it is understood that the use of maleic anhydride (MA) as a copolymerization component has the effect of improving the physical properties of polyester for binder and reducing the production cost.

Claims (7)

Terephthalic acid or an ester-forming derivative thereof, and an acidic component comprising maleic anhydride (MA) of the following formula (1) or maleic anhydride (MA) of terephthalic acid and isophthalic acid or ester-
Ethylene glycol or ethylene glycol and a diol having a boiling point of less than 300 ° C are synthesized as a co-polyester with a diol component,
Wherein the maleic anhydride (MA) is added during the esterification reaction and when the reaction rate of the esterification reaction is 92 to 98%, the copolymerization polyester is produced.
[Chemical Formula 1]

The method according to claim 1,
Wherein the acidic maleic anhydride (MA) is added in an amount of 1 to 30 mol% based on the molar amount of the copolymerized polyester. The method according to claim 1,
Wherein the diol having a boiling point of less than 300 캜 is added in an amount of 1 to 30 mol% based on the molar amount of the copolymer polyester. delete The method according to claim 1,
The diol having a boiling point of less than 300 ° C is one or more selected from the group consisting of 1,4-cyclohexane dimethanol, neopentyl glycol, diethylene glycol, 1,4-butanediol, and 1,3-propanediol Wherein the thermosetting property is improved. A copolymer polyester for a binder, which is produced by the production method of any one of claims 1, 2, 3 and 5. 7. A polyester-based binder fiber comprising the copolymerized polyester for a binder according to claim 6.