KR102003888B1 - Crystalline low melting Polyester binder resin with improved heat resistance - Google Patents

Abstract

The present invention is formed of a terephthalic acid or an ester-forming derivative thereof, an acid component consisting of succinic acid and a diol component consisting of ethylene glycol (Ethylene Glycol), wherein the succinic acid contains 20-40 mol% of the acid component. The present invention relates to a crystalline low melting polyester binder resin having improved heat resistance.

Description

Crystalline low melting polyester binder resin with improved heat resistance

The present invention relates to a crystalline low melting point polyester binder resin having improved heat resistance and to a crystalline low melting point polyester binder resin having heat resistance that does not lower the adhesive force at a high temperature.

As the heat-sealing binder fiber used to bond the filaments or short fibers constituting the web or sheet of the nonwoven fabric, a low-melting polyester binder fiber having a heat bonding processing temperature of 160 to 200 ° C is mainly used.

These low melting polyester binder fibers are prepared by synthesis of acid components such as terephthalic acid, isophthalic acid and aliphatic dicarboxylic acids having 30 or less carbon atoms, and diol components such as diethylene glycol, tetramethylene glycol, neopentyl glycol, and polyethylene glycol. The physical properties such as melting point can be controlled depending on the type and content of the powder and diol components, and thus the properties such as processability and adhesiveness of the polyester binder fiber may be greatly influenced.

The most commonly used low melting polyester binder fiber is copolymerized with terephthalic acid using isophthalic acid. At this time, isophthalic acid is added as 20 ~ 45 mol% of acid component. It has a final melting point in the range of 145 ~ 180 ℃ can be used as a polyester fiber for the binder.

However, polyester resins for binders using isophthalic acid form a cyclic compound having a polymerization degree of 2 to 3 when synthesized, and the melting point of the cyclic compound is not melted at a polyester spinning temperature of about 325 ° C. This has the disadvantage of shortening the pack replacement cycle, and is usually also expensive for isophthalic acid.

In addition, diethylene glycol may be used as a copolymerization material, and polyester resins synthesized by copolymerizing diethylene glycol have a large drop in glass transition temperature, which causes problems in fusion between fibers during stretching process, product transportation, or dropping. Strong adhesive strength

In addition, U.S. Patent Invention No. 44065439 introduces a low melting point polyester using terephthalic acid, isophthalic acid, adipic acid, ethylene glycol, and neopentyl glycol, but the melting point is too low at 45 to 60 ° C, which may cause strength and fusion problems. There is.

In addition, Korean Patent Publication No. 2001-11548 uses terephthalic acid and phthalic anhydride as acid components and ethylene glycol and diethylene glycol as diol components, but high temperature (270-290 ° C.) and high vacuum, which are general polyethylene terephthalate copolymerization conditions Pyrolysis and side reactions occur at less than 1torr, causing polymer color defects.

Korean Patent No. 1099023 polycondensates an acid component including terephthalic acid, isophthalic acid and adipic acid and a diol component including ethylene glycol and 1,4-butanediol to have no melting point, and a softening temperature of 80 to 100 ° C. Melting point polyester binder resin has a heat resistance, but due to the use of 1,4-butanediol has a problem that the thermal stability and the radiation yield is lowered due to the generation of a large amount of tetrahydrofuran (THF) during the polycondensation reaction.

The present invention has been invented to solve the problems of the prior art as described above, and an object of the present invention is to provide a crystalline low melting point polyester-based binder resin having excellent adhesive strength and improved heat resistance that does not degrade at high temperatures.

In addition, an object of the present invention is to provide a crystalline low melting polyester binder resin having improved heat resistance and high economical efficiency due to no high side yield due to no side reactions caused by side reactions when the low melting polyester binder resin is polycondensed.

The present invention is formed of a terephthalic acid or an ester-forming derivative thereof, an acid component consisting of succinic acid and a diol component consisting of ethylene glycol (Ethylene Glycol), wherein the succinic acid contains 20-40 mol% of the acid component. Provided is a crystalline low melting polyester binder resin having improved heat resistance.

In addition, the low melting polyester binder resin provides a crystalline low melting polyester binder resin with improved heat resistance, characterized in that the melting point of 160 ~ 200 ℃.

In addition, the low-melting polyester-based binder resin provides a crystalline low-melting polyester-based binder resin with improved heat resistance, characterized in that the intrinsic viscosity (IV) is 0.6 ~ 0.8dl / g.

In addition, the low-melting point polyester-based binder resin provides a crystalline low-melting point polyester-based binder resin with improved heat resistance, characterized in that the heat resistance (ΔH) is 7.0 ~ 8.0J / g.

In addition, there is provided a fiber which is formed of the low-melting-point polyester-based binder resin.

In addition, the low-melting point polyester-based binder resin when provided with fibers to provide a fiber, characterized in that the yield is 95% or more.

As described above, the crystalline low melting polyester binder resin having improved heat resistance according to the present invention has excellent heat resistance by using terephthalic acid or its ester-forming derivative and succinic acid as an acid component.

In addition, the succinic acid contained as an acid component does not produce side reactions by side reactions in the condensation polymerization process, so the radiation yield is high, economic efficiency is high, and physical properties are improved.

Hereinafter, a preferred embodiment of the present invention will be described in detail. First, in describing the present invention, a detailed description of related known functions or configurations will be omitted so as not to obscure the subject matter of the present invention.

As used herein, the terms 'about', 'substantially', and the like, are used at, or in close proximity to, numerical values when manufacturing and material tolerances inherent in the stated meanings are set forth, and an understanding of the present invention may occur. Accurate or absolute figures are used to assist in the prevention of unfair use by unscrupulous infringers.

The present invention relates to a crystalline low melting polyester binder resin having improved heat resistance formed from a terephthalic acid or an ester-forming derivative thereof, an acid component consisting of succinic acid, and a diol component consisting of ethylene glycol (Ethylene Glycol). .

The succinic acid used in the present invention is a dicarboxylic acid called succinic acid, succinic acid, butanediic acid, and has a chemical formula as shown below.

[Formula 1]

The succinic acid acts as an acid component when preparing a polyester resin, and in addition to the effect of lowering the melting point of the polyester as a fatty acid, the succinic acid maintains the crystallinity of the polyester to improve heat resistance.

Generally, 1,4-butanediol is used as a diol component to impart heat resistance while lowering the melting point of a polyester resin, but the 1,4-butanediol generates a large amount of tetrahydrofuran (THF) during the condensation polymerization process. There is a problem of lowering the thermal stability and lowering the yield of the polyester resin, but the succinic acid used in the present invention does not generate the side reactions as described above can improve the heat resistance of the polyester resin and improve the yield.

In addition, the succinic acid has the advantage of not lowering the intrinsic physical properties of the polyester resin, even if the succinic acid is contained in the polyester resin and does not lower the intrinsic viscosity of the polyester resin.

The content of the succinic acid may be adjusted according to the physical properties of the low melting polyester binder resin to be prepared, but it may be preferable to contain 20 to 40 mol% of the acid component in order to satisfy the low melting point properties and heat resistance.

When the succinic acid is contained less than 20 mol% of the acid component, the melting point of the polyester resin produced is not more than 200 ℃ low melting point characteristics, when the succinic phase is contained more than 40 mol% of the acid component Melting | fusing point of a polyester resin becomes low too much and heat resistance may fall.

As described above, the low melting polyester binder resin of the present invention formed using succinic acid as an acid component may have a melting point of 160 to 200 ° C. and an intrinsic viscosity (IV) of 0.6 to 0.8 dl / g.

In addition, the crystalline low melting point polyester-based binder resin of the improved heat resistance of the present invention will be able to prevent the adhesive force from deteriorating even at high temperatures with a heat resistance (ΔH) of 7.0 to 8.0 J / g.

When the fiber is manufactured by using the crystalline low melting point polyester-based binder resin having improved heat resistance according to the present invention, the fiber may be used alone, and the sheath-core composite fiber may be used for economy and convenience. It will be preferable to form and use.

In the case of forming the sheath-core composite fiber, a crystalline low melting point polyester-based binder resin having improved heat resistance according to the present invention may be formed of a sheath portion.

Fiber having a yield of at least 95% when the fiber is formed of the low melting point polyester-based binder resin.

Hereinafter, an embodiment of a method for producing a crystalline low melting polyester binder resin having improved heat resistance according to the present invention is shown, but the present invention is not limited to the examples.

EXAMPLE  1 to 5

Terephthalic acid (TPA) and ethylene glycol (EG) were added to an ester reactor, and a general polymerization reaction was performed at 258 ° C. to prepare a polyethylene terephthalate polymer (PET oligomer) having a reaction rate of about 96%. Sintered acid (SA) was mixed in the prepared polyethylene terephthalate (PET) in the content ratio shown in Table 1 below, and a transesterification reaction was performed at 250 ± 2 ° C. by adding a transesterification catalyst. Then, the polycondensation reaction catalyst was added to the obtained reaction mixture, and the polycondensation reaction was carried out while controlling the final temperature and pressure in the reaction tank to be 280 ± 2 ° C. and 0.1 mmHg, respectively.

Comparative example  1 to 4

A low melting polyester binder resin was prepared in the same manner as in Example 1, but 1,4-butanediol (BD) was used in the diol component instead of succinic acid in the content ratio shown in Table 1 below.

division Acid Diol component TPA (mol%) SA (mol%) EG (mol%) BD (mol%) Example 1 95 5 100 - Example 2 90 10 100 - Example 3 80 20 100 - Example 4 70 30 100 - Example 5 60 40 100 - Comparative Example 1 100 - 70 30 Comparative Example 2 100 - 60 40 Comparative Example 3 100 - 50 50 Comparative Example 4 100 - 40 60

◈ Measurement of physical properties of Examples and Comparative Examples

Melting point, intrinsic viscosity, heat resistance, and tetrahydrofuran (THF) content of the low melting point polyester-based binder resins prepared in Examples 1 to 5 and Comparative Examples 1 to 4 were measured. The spinning yield was calculated by single spinning the melting point polyester-based binder resin. The measured physical properties are shown in Table 2.

(1) Melting point, heat resistance measurement

It was measured using a thermodifferential scanning calorimeter (Perkin Elmer, DSC-7).

(2) Intrinsic viscosity (IV) measurement

The polyester resin was dissolved at a concentration of 0.5% by weight in a solution in which phenol and tetrachloroethane were mixed at a 1: 1 weight ratio, and then an intrinsic viscosity (I.V) was measured at 35 ° C using a Uberod viscometer.

(3) THF content measurement

The content of EG, BD, H2O, and THF in the sample was measured by Gas Chromatography (area ratio by peak)

Esterification sample: distillation column bottom reaction effluent

-Polycondensation sample: Ejector pass-through reaction effluent

(4) radiation yield

The yield was calculated by the following formula by measuring the amount of polyester resin used and the amount of fiber spun.

 Emissivity (%) = (amount of spun fiber (kg) / amount of PET resin used (kg)) * 100

division IV
(dl / g) Tm
(℃) Heat resistance
(ΔH, J / g) Emission yield
(%) THF content
(wt%) Example 1 0.641 239.8 8.1 97.3 0 Example 2 0.647 215.3 7.4 97.3 0 Example 3 0.638 198.7 7.7 97.5 0 Example 4 0.643 183 7.3 97.1 0 Example 5 0.642 161.7 7.3 97.0 0 Comparative Example 1 0.639 191 5.1 93.1 19.8 Comparative Example 2 0.642 186 5.9 92.7 25.6 Comparative Example 3 0.641 177 6.5 85.4 28.7 Comparative Example 4 0.643 169 6.3 81.7 33.1

As shown in Table 2, Examples 1 to 4 of the crystalline low melting polyester binder resin having improved heat resistance of the present invention can be seen that the heat resistance of all 7J / g is superior to the comparative examples.

When succinic acid (SA) is contained in less than 20 mol% of the acid component as in Examples 1 and 2, the melting point is 200 ℃ or more, and in the case of 40 mol% of the acid component as in Example 5, the melting point is 160 ℃ early When the melting point of the crystalline low melting polyester binder resin with improved heat resistance is adjusted to 160 ~ 200 ℃ it will be preferable that the succinic acid is contained 20 to 40 mol% of the acid component.

In addition, although the THF was not contained in the low melting point polyester-based binder resins of Examples 1 to 5, Comparative Examples 1 to 4 using 1,4-butanediol (BD) contained a large amount of THF. have.

The content of THF and the THF has a great effect on the spinning yield when the low melting point polyester-based binder fiber is fiberized. Examples 1 to 5 of the present invention showed that the spinning yield was very high as 97% or more. Examples 1 to 4 can be seen that the lower the radiation yield than the embodiment. In particular, it can be seen that the higher the yield of 1,4-butanediol (BD), the lower the yield.

As shown in the results shown in Table 2, the low-melting-point polyester-based binder resin according to the present invention using succinic acid may be more economically superior to Comparative Examples 1 to 4 using 1,4-butanediol having high heat resistance and high emissivity. will be.

Claims (6)

Terephthalic acid or its ester-forming derivative, an acid component consisting of succinic acid and a diol component consisting of ethylene glycol (Ethylene Glycol),
The succinic acid is a low-melting polyester-based binder resin containing 30 to 40 mol% of an acid component and does not contain tetrahydrofuran (THF) and has a heat resistance (ΔH) of 7.0 to 8.0 J / g. Improved crystalline low melting polyester binder resin. The method of claim 1,
The low melting point polyester binder resin is a crystalline low melting point polyester binder resin having improved heat resistance, characterized in that the melting point of 160 ~ 200 ℃. The method of claim 1,
The low-melting polyester-based binder resin is crystalline low-melting polyester binder resin with improved heat resistance, characterized in that the intrinsic viscosity (IV) of 0.6 ~ 0.8dl / g. delete Fiber formed from the low-melting-point polyester-type binder resin in any one of Claims 1-3. The method of claim 5,
Fiber with a low melting point polyester-based binder resin, the fiber yield of 95% or more when forming a fiber.