KR20220086807A - Novel Polyester rejin for binder - Google Patents

Abstract

단, m과 n은 몰%로 m+n=100%이고, a는 중합도임The present invention relates to a polyester resin of the following [Formula 1], wherein the polyester resin has a difference between a melt viscosity of 220 °C and a melt viscosity of 260 °C of 700 poise or less and relates to a new polyester resin for a binder.
[Formula 1]

However, m and n are mol%, m+n=100%, and a is the degree of polymerization

Description

Novel Polyester rejin for binder

The present invention relates to a novel polyester resin for a binder, and to a novel polyester resin for a binder suitable for a binder having a chemical structure different from that of the conventional polyester resin for a binder.

Polyester, as an eco-friendly material, has excellent mechanical properties, heat resistance and chemical resistance, and thus can be used in various fields requiring light weight and high physical properties. Recently, the role of polyester fibers represented by polyethylene terephthalate (PET) is increasing in the field of fibers such as nonwovens. Specifically, an example is that the demand for heat-adhesive fibers that can be used for adhesive cores for clothing or automobile interior materials using polyester resin as an adhesive component is increasing.

Accordingly, various efforts are being made to improve the physical properties of polyester fibers to expand their utility, and as part of these efforts, a technology to control the temperature such as softening point or glass transition temperature by modifying the structure of polyester resin are being studied For example, a technology for controlling the melting point or glass transition temperature of a polyester resin has been developed by copolymerizing dicarboxylic acids such as terephthalic acid, isophthalic acid, adipic acid, and sebacic acid with a diol compound such as ethylene glycol and neopentyl glycol. have.

In particular, when manufacturing a web or sheet of non-woven fabric with polyester fiber, the heat-sealing binder polyester fiber used to bond filaments or short fibers has a heat-bonding processing temperature of 120 to 200°C, which is a common polyethylene terephthalate. It should have a lower melting or softening point compared to phthalate fibers.

For this purpose, in synthesizing a polyester resin, copolymerization with terephthalic acid using isophthalic acid as a copolymerization component is a representative method. At this time, isophthalic acid is added in an amount of 20 to 45 mol% based on the mole of the ester, and the polyester resin synthesized in this way is amorphous It has a molecular structure in the form of a final melting point in the range of 145 ~ 180 ℃ and can be used as a polyester fiber for binder.

However, when synthesizing the polyester resin for a binder using isophthalic acid, a cyclic compound having a polymerization degree of 2 to 3 is formed. Since this cyclic compound has a melting point of about 325°C, it does not melt at the polyester spinning temperature, so it acts as a foreign material during spinning and shortens the pack exchange cycle. become a factor of

U.S. Patent No. 4,129,675 discloses a low-melting-point polyester binder containing terephthalic acid and isophthalic acid as main components, but this is uneconomical because it requires a temperature of 200° C. or higher during thermal bonding.

U.S. Patent No. 4,166,896 discloses a method for preparing unsaturated polyester by copolymerizing unsaturated dicarboxylic acid with a low molecular weight substance obtained by depolymerizing polyester. There are disadvantages in that it has an excessively high melting point and high crystallinity.

U.S. Patent No. 4,065,439 discloses a low-melting 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 too low to be used as a core for clothing, and its shape stability in high temperature conditions is also weak.

On the other hand, Korean Patent Laid-Open No. 2001-11548 discloses polycondensation polymerization of a dicarboxylic acid component of terephthalic acid and phthalic anhydride and a diol component of ethylene glycol and diethylene glycol, which has excellent adhesion to polyester and does not cause yellowing after adhesion. Although a binder for ester-based fibers is provided, the binder has a complex reaction mechanism by using phthalic anhydride directly, and thus the polycondensation temperature must be lowered to prevent the problem of poor color of the co-polyester.

In addition, Korean Patent Registration No. 1684234 uses terephthalic acid as an acid component and 2-methyl-1,3-propanediol and ethylene glycol as the main components for the diol component, so that the softening point is in the range of 110 to 130° C. for binders. It is disclosed that it can be used for polyester fibers.

As described above, polyester resins of various chemical compositions have been developed as polyester resins for binders using various copolymer compounds, but polyester resins for binders that are actually used are limited, and compounds used for copolymerization of polyester resins for binders If supply is not smooth due to various factors such as difficulties in supply and demand, sharp rise in prices, product production may be disrupted.

Therefore, various products are required through diversification of copolymer compounds used in polyester resins for binders, and there is a need to develop polyester resins for binders having binder properties similar to or superior to those of commercialized polyester resins for binders.

The present invention was invented to solve the problems of the prior art, and has a chemical structure different from that of a conventional polyester resin for a binder, but has similar or superior binder properties to that of a conventional polyester resin for a binder. It aims to provide a resin.

In addition, an object of the present invention is to provide a polyester resin for binders of various uses by controlling physical properties through molecular weight distribution.

The present invention is a polyester resin of the following [Formula 1], wherein the polyester resin has a difference between a melt viscosity of 220 ° C and a melt viscosity of 260 ° C of 700 poise or less. provides

[Formula 1]

However, m and n are mol%, m+n=100%, and a is the degree of polymerization

In addition, the polyester resin provides a novel polyester resin for a binder, characterized in that the melt viscosity of 260 ℃ 500 ~ 1,300 poise (poise).

In addition, the polyester resin provides a novel polyester resin for a binder, characterized in that the molecular weight distribution (Mw / Mn) is 2.0 ~ 3.5.

In addition, n in [Formula 1] provides a novel polyester resin for a binder, characterized in that 30 to 50 mol%.

In addition, a in [Formula 1] provides a novel polyester resin for a binder, characterized in that 50 to 100.

In addition, there is provided a fiber comprising the polyester resin for the binder.

As described above, the novel polyester resin for a binder according to the present invention has a chemical structure different from that of the conventional polyester resin for a binder, but has the effect of having similar or superior binder properties to the conventional polyester resin for a binder.

In addition, there is an effect of providing a polyester resin for a binder for various uses by controlling the physical properties through the molecular weight distribution.

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

As used herein, the terms 'about', 'substantially' and the like are used in a sense at or close to the numerical value when the manufacturing and material tolerances inherent in the stated meaning are presented, and serve to enhance the understanding of the present invention. To help, precise or absolute figures are used to prevent unfair use by unconscionable infringers of the stated disclosure.

The present invention relates to a new polyester resin for a binder, characterized in that the difference between the melt viscosity of 220 ° C and the melt viscosity of 260 ° C is 700 poise or less as the polyester resin of the following [Formula 1].

[Formula 1]

However, m and n are mol%, m+n=100%, and a is the degree of polymerization

The polyester resin for the binder is a polyester resin containing a composition that does not have a benzene ring as shown in Formula 1, and reduces the number of benzene rings compared to the polyester resin formed of terephthalic acid and ethylene glycol to increase the flowability of the entire molecular chain. increasing and the melting point is lowered.

In addition, the polyester resin for a binder of the present invention may have improved sagging properties when it is formed into fibers, films, and molded articles because packing properties increase due to reduction of benzene rings in the molecular chain.

When the n content of the polyester resin for the binder of the present invention is 30 mol% or more, the polymer becomes amorphous and has thermal properties similar to those of the conventional low-melting-point polyester resin for binders containing isophthalic acid. Due to the flexible molecular chains present in the polymer main chain, the elasticity is improved, thereby improving the tear properties during binding of the nonwoven fabric.

That is, the softening point (Ts) and / or the glass transition temperature (Tg) by inducing an increase in the degree of freedom of the main chain and a decrease in the crystallinity of the resin according to the content of the composition not having a benzene ring of the novel polyester resin for the binder of the present invention can be adjusted. This may exhibit the same effect as in the case of using isophthalic acid (IPA) containing an asymmetric aromatic ring in order to reduce the crystallinity of the conventional crystalline polyester resin.

Therefore, the n is preferably 30-50 mol%. If n is less than 30 mol%, the polyester resin has crystallinity and low melting point characteristics may not be expressed, and when n exceeds 50 mol%, the benzene ring is The content of the non-existent components may increase, thereby reducing the physical properties of the polyester resin.

In addition, when the degree of polymerization is too small, the physical properties of the polyester are reduced, and when the degree of polymerization is too large, the polymerization process is difficult and may take a long time.

The novel polyester resin for a binder of the present invention formed as described above has a low melting point poly that does not rapidly decrease the melt viscosity at high temperature with a difference between the melt viscosity of 220°C and the melt viscosity of 260°C of 700 poise or less. It is an ester resin.

The lower the difference between the melt viscosity of 220 ° C. and the melt viscosity of 260 ° C. of the polyester resin, the better the processability is improved, and it will be more preferably 500 poise or less.

The difference between the melt viscosity of 220 ° C and the melt viscosity of 260 ° C of the polyester resin reduces the drop width of the melt viscosity that is lowered as the temperature rises, so that the difference in melt viscosity can be adjusted to 700 poise or less. The melt viscosity of the polyester resin may be controlled according to the molecular weight and molecular weight distribution (Mw/Mn).

The polyester resin according to the present invention may preferably have a molecular weight distribution (Mw/Mn) of 2.0 to 4.0 so that a high melt viscosity is maintained at a high temperature.

In general, the molecular weight and molecular weight distribution of a polyester resin can increase the molecular weight and molecular weight distribution by suppressing the reverse reaction in the polymerization process. can lower

In order to prepare the molecular weight distribution to be less than 2, it is necessary to polymerize for a long time at high temperature and high pressure. Since the melt viscosity may drop rapidly at high temperatures, it would be desirable to have a molecular weight distribution of 4.0 or less.

The molecular weight distribution (Mw/Mn) of the polyester resin of the sheath portion according to the present invention is most preferably in the range of 2.0 to 3.5.

As described above, the low-melting-point polyester resin of the present invention formed by [Formula 1] has a softening temperature of 100 ° C to 150 ° C, a glass transition temperature (Tg) of 50 ° C to 90 ° C, and an intrinsic viscosity of 0.50 ㎗ / g or more. It has excellent physical properties.

As described above, the novel polyester resin for binder of the present invention can be thermally bonded at a low temperature in a range similar to the temperature applied to the existing binder resin, and processability is improved, and the glass transition temperature is higher than 50 ° C. It may be manufactured from various materials such as a film, a molded body, and the like. In particular, strong strength is maintained even when durability and shape stability are required in a high-temperature atmosphere, such as automobile interior products, and the non-woven fabric for molding has the advantage of preventing sagging in a high-temperature atmosphere. will be able

Hereinafter, examples of a method for producing a novel polyester resin for a binder according to the present invention are shown, but the present invention is not limited to the examples.

Examples 1 to 6

The polyester resin for the binder was polymerized so that n of [Formula 1] had 45 mol% by using the monomers of the following [Formula 2], [Formula 3], and [Formula 4].

As shown in Table 1 below, the polyester resin for the binder has an intrinsic viscosity of about 0.56 dl/g, and a novel polyester resin for a binder having different molecular weights and molecular weight distribution according to Examples was prepared.

[Formula 2]

[Formula 3]

[Formula 4]

division softening point
(℃) Tg
(℃) IV
(dl/g) Mn Mw molecular weight distribution degree of polymerization
(a) melt viscosity (poise) 220℃ 240℃ 260℃ Example 1 118.3 68.9 0.566 10800 45100 4.17 56.3 1037 833 461 Example 2 119.2 69.8 0.563 13000 47600 3.66 65.2 1197 892 517 Example 3 118.7 69.7 0.567 13700 45900 3.35 71.3 1234 978 813 Example 4 116.7 69.4 0.561 13200 40900 3.09 72.1 1308 1136 981 Example 5 117.1 68.9 0.565 13900 37400 2.69 73.4 1398 1232 1071 Example 6 116.1 69.5 0.563 13500 32100 2.37 78.7 1511 1371 1233

As shown in Table 1, it can be seen that the melt viscosity increases as the molecular weight distribution decreases, and through Example 3, the melt viscosity at 260°C at a polymerization degree of 3.5 or less is 800 poise or more. Able to know.

In addition, it can be seen that when the polymerization degree is increased, the molecular weight distribution is lowered. Through Examples 3 to 6, the difference between the melt viscosity of 220°C and the melt viscosity of 260°C at a polymerization degree of 3.5 or less is 200-500 poise. It can be seen that the difference is very small.

◈ Measurement of physical properties of Examples 1 to 6

After the polyester resin for the binder prepared in Examples 1 to 6 was formed into the polyester fiber for the binder, the compressive hardness was measured to measure the suitability and adhesiveness for the binder.

The polyester fiber for the binder is manufactured in a sheath-core type, and the core part uses polyethylene terephthalate, and the sheath part uses the polyester resin for the binder prepared in Example, and the weight ratio of the sheath part and the core part is 50:50, a general composite spinning process. was prepared through

(1) Measurement of softening point (or melting point) and glass transition temperature (Tg)

The glass transition temperature (Tg) of the copolymerized polyester resin was measured using a differential scanning calorimeter (Perkin Elmer, DSC-7), and the softening behavior was measured in TMA mode using a dynamic mechanical analyzer (DMA-7, Perkin Elmer). did

(2) Measurement of intrinsic viscosity (IV)

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

(3) Melt viscosity measurement

After melting the polyester resin at the measurement temperature, the melt viscosity was measured using RDA-III manufactured by Rheometric Scientific. Specifically, when measuring from the initial frequency = 1.0 rad/s to the final frequency = 500.0 rad/s under the frequency sweep condition at the set temperature, the value at 100 rad/s was calculated as the melt viscosity.

(4) Compressive hardness measurement

After opening 5 g of polyester fiber and stacking it in a circular mold with a diameter of 10 cm to a height of 5 cm, thermal bonding was performed at a set temperature for 90 seconds to prepare a cylindrical molded article. The manufactured molded article was compressed by 75% through Instron, and the load applied to the compression was measured to measure the compression hardness. In this experiment, the compression hardness was measured by thermal bonding at 140 °C, 150 °C, and 160 °C, respectively.

(5) Measurement of radiation yield (%, 24hr)

The spinning yield was calculated by the following formula by measuring the amount of polyester resin used and the amount of fibers spun for 24 hours.

Spinning yield (%) = (Amount of spun fiber (kg) / Amount of PET resin used (kg)) * 100

(6) Molecular weight measurement

The number average molecular weight (Mn) and weight average molecular weight (Mw) of the polyester resin were measured by GPC analysis.

* GPC (Gel permeation chromatograph) analysis instrument conditions

1) Analysis device: Tosoh EcoSEC HLC-8320 GPC

2) Detector: RI-Detector

3) Developing solvent: CHCl ₃ (chloroform)

4) Column: 2 X Shodex LF-804 + Shodex KF-802.5 (7.8 x 300mm)

5) Temperature: 40℃

6) Flow rate: 1.0mL/min

7) Standard material: Polystyrene

division Compressive hardness (kgf) radiation yield
(%, 24hr) 140℃ 150℃ 160℃ Example 1 1.4 2.6 3.3 97.8 Example 2 1.6 3.3 4.2 98.9 Example 3 2.4 4.2 5.1 99.2 Example 4 3.5 4.4 5.6 99.5 Example 5 3.4 4.6 5.6 99.4 Example 6 3.7 4.7 5.8 99.5

As for the compression hardness, the higher the numerical value, the better the thermal adhesiveness between the fibers of the molded article. It can be seen that the thermal adhesiveness is improved by increasing.

As described above, the molecular weight distribution of the polyester resin for the binder for the sheath according to the present invention is closely related to the spinning processability and thermal adhesiveness. It is difficult to manufacture less than 2, and the polyester resin for a binder according to the present invention preferably has a molecular weight distribution of 2 to 4, more preferably 2.0 to 3.5.

In addition, in Examples 1 to 6, it can be seen that all of the spinning yields were 97% or more, showing excellent processability when manufacturing fibers using the novel polyester resin for binders of the present invention.

Claims (6)

To the polyester resin of the following [Formula 1],
The polyester resin is a novel polyester resin for a binder, characterized in that the difference between the melt viscosity of 220 ℃ and the melt viscosity of 260 ℃ is 700 poise or less.
[Formula 1]

However, m and n are mol%, m+n=100%, and a is the degree of polymerization The method of claim 1,
The polyester resin is a novel polyester resin for a binder, characterized in that the melt viscosity of 260 ℃ 500 ~ 1,300 poise (poise). The method of claim 1,
The polyester resin is a novel polyester resin for a binder, characterized in that the molecular weight distribution (Mw / Mn) is 2.0 ~ 3.5. The method of claim 1,
n of the [Formula 1] is a novel polyester resin for a binder, characterized in that 30-50 mol%. The method of claim 1,
A of the [Formula 1] is a novel polyester resin for a binder, characterized in that 50 to 100. A fiber comprising the polyester resin for a binder according to any one of claims 1 to 5.