KR20190023627A - Method for preparing polyetherester copolymer - Google Patents

Abstract

The present invention relates to a method for preparing a polyetherester copolymer having excellent color characteristics of a high molecular weight in a short time. The method comprises a step of allowing polyester and polyether to have a condensation polymerization reaction under vacuum atmosphere, wherein the condensation polymerization reaction is performed under an elevated temperature condition of a rate of 5 to 15°C/1hr in the temperature range of 230 to 250°C.

Description

METHOD FOR PREPARING POLYETHERESTER COPOLYMER [0002]

The present invention relates to a method for producing a polyetherester copolymer capable of producing a polyetherester copolymer having a high molecular weight and excellent coloring characteristics in a relatively short period of time and capable of reducing a total volatile organic compound (tVOC) .

Thermoplastic polyester elastomer is a high-performance material that combines elasticity of rubber and molding processability of plastic. It replaces vulcanized rubber and PVC (polyvinyl chloride). It is used for automobile, home appliance, IT, Which is used in a wide range of fields.

Among them, polybutylene terephtalate (PBT) - poly (tetramethylene ether glycol) (PTMEG) copolymer has the advantage of mixing the physical properties of two polymers. Specifically, PBT is a solid PTMEG plays a role of a soft segment, a soft segment, and exhibits special properties depending on the content of the two polymers.

The manufacturing process of the PBT-PTMEG copolymer is divided into two types.

The first method is to introduce dimethyl terephthalate (DMT) or terephthalic acid (TPA) together with 1,4-butanediol (BDO) and PTMEG into a raw material under atmospheric pressure, And then condensation polymerization is carried out in a vacuum atmosphere to prepare a PBT-PTMEG copolymer. In this condensation polymerization reaction, the terminal BDO (1,4-butanediol) is condensed with the condensation to extract volatile BDO.

Another method is to obtain PBT-PTMEG copolymer which is relatively expensive PBT-PTMEG with one-stage polycondensation reaction in a vacuum atmosphere with PTMEG as a raw material. In this case, the main reaction path is as follows.

Step 1) -C ₆ H ₅ COO (CH ₂ ) ₄ OCOC ₆ H ₅ - + HO [(CH ₂ ) ₄ O] _n H

Step 2) -C ₆ H ₅ COO (CH ₂ ) ₄ OH + -C ₆ H ₅ COO [(CH ₂ ) ₄ O] _n H

Step _{3) -C 6 H 5 COO [} (CH 2) 4 O] nCOC 6 H5- + HO (CH 2) 4 OH

When the PBT and PTMEG are mixed on the titanium catalyst, the intermediate BDO chain (-O (CH ₂ ) ₄ O-) of the PBT rapidly reacts with the terminal group BDO (-O (CH ₂ ) ₄ OH) and the terminal PTMEG (-O [(CH ₂ ) ₄ O] _n H). When the BDO is continuously volatilized in a vacuum atmosphere, it undergoes a condensation reaction in which the equilibrium reaction is converted from step 2) to step 3). At this time, the same amount of BDO as the input PTMEG equivalence ratio is extracted. Also, as the reaction progresses from step 2) to step 3), the viscosity of the medium is increased and mass transfer limitation is imposed. Therefore, a special stirrer or reactor is required which facilitates surface renewal.

Isothermal reaction is usually performed for ease of operation. Operating temperature is a direct variable to product properties and productivity. The higher the temperature, the faster the reaction from step 1) to step 3). On the other hand, since the chain decomposition reaction and the tetrahydrofuran (THF) production reaction also increase, the molecular weight increases and the amount of tVOC is also increased. On the other hand, the productivity lowers at a low temperature, and the longer the reaction time, the lower the color characteristic due to the yellowing.

An object of the present invention is to solve the above problems and to provide a method for producing a polyetherester copolymer capable of producing a polyetherester copolymer having a high molecular weight and excellent color characteristics in a relatively short time and capable of reducing tVOC .

According to one embodiment of the present invention, there is provided a process for producing a polyester resin composition, comprising the step of polycondensation of a polyester and a polyether, wherein the polycondensation reaction is carried out at a temperature of 230 to 250 ° C at a rate of 5 ° C / Lt; RTI ID = 0.0 > C / 1 hr. ≪ / RTI >

The polyetherester copolymer according to the present invention can reduce the tVOC and can produce a polyetherester copolymer having a high molecular weight and a good color characteristic in a relatively short time.

1 is a graph showing changes in reaction temperature with the reaction time in the production of the polyetherester copolymer according to Examples 1 and 2 and Comparative Examples 1 to 4.
2 is a graph showing changes in the number average molecular weight of the polyetherester copolymer according to the reaction time in the production of the polyetherester copolymer according to Examples 1 and 2 and Comparative Examples 1 to 4.

The terminology used herein is for the purpose of describing exemplary embodiments only and is not intended to be limiting of the invention. The singular expressions include plural expressions unless the context clearly dictates otherwise. In this specification, the terms "comprises", "comprising", or "having" are used to designate the presence of stated features, steps, components, or combinations thereof, and are not intended to preclude the presence of one or more other features, Components, or combinations thereof, as a matter of convenience, without departing from the spirit and scope of the invention.

While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and will herein be described in detail. It should be understood, however, that the invention is not intended to be limited to the particular forms disclosed, but includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.

Hereinafter, a method for producing the polyetherester copolymer according to the present invention will be described in detail.

A method for producing a polyetherester copolymer according to an embodiment of the present invention includes a step of condensation polymerization of a polyester and a polyether in a vacuum atmosphere,

The polycondensation reaction is carried out at a temperature ranging from 230 ° C to 250 ° C at a rate of 5 ° C / 1 hr to 15 ° C / 1 hr.

Conventionally, in the production of a polyetherester copolymer by the polycondensation reaction of a polyester and a polyether, the molecular weight rapidly increases at a high temperature, but the maximum molecular weight is lowered by thermal decomposition. Under a relatively low temperature condition, A high molecular weight copolymer can be produced. However, the reaction time at the time of production becomes long under the condition of low temperature, and as a result, not only the productivity is lowered but also the color is adversely affected, so that the operation temperature condition is required to obtain a high molecular weight in a short time.

On the other hand, in the present invention, it is possible to produce a high molecular weight copolymer having excellent color in a relatively short time by controlling the reaction temperature rate so that the polycondensation reaction is carried out under elevated temperature conditions and an appropriate temperature gradient is achieved during the reaction, the occurrence of tVOC can be minimized.

Further, the above-mentioned effect can be further improved by optimizing the temperature raising rate, and accordingly, the polycondensation reaction can be carried out more specifically at a temperature range of 230 to 250 DEG C at a rate of 8 DEG C / 1 hr to 15 DEG C / More specifically at a rate of 10 ° C / 1 hr to 15 ° C / 1 hr.

In addition, the above-mentioned temperature condition and the condensation polymerization reaction time may affect the color of the copolymer to be finally produced. Specifically, when the temperature during the polycondensation reaction is higher than 250 ° C. or progresses at a lower temperature of less than 230 ° C., and the polycondensation reaction time is prolonged, the color characteristics such as yellowing of the copolymer produced may be deteriorated. In the production process according to an embodiment of the present invention, the polycondensation reaction can be carried out within a temperature range of 230 to 250 ° C, more specifically, at a temperature of 230 to 250 ° C for 2.5 hours or less.

The polycondensation reaction can be carried out under vacuum conditions, more specifically under a vacuum pressure of 1 mbar or less. When the polymerization is carried out under the above-mentioned vacuum pressure, the rate of condensation polymerization reaction can be easily controlled, and as a result, a copolymer having excellent color characteristics of a high molecular weight can be produced with good yield.

Further, the polycondensation reaction can be carried out in the presence of a catalyst.

The catalysts include titanium catalysts such as tetrabutyl titanate (TBT), tetraethyl titanate or tetra (isopropyl) titanate; Or n-butylstannoic acid, octylstannoic acid, dimethyltin oxide, dibutyltin oxide, dioctyltin oxide, diphenyltin oxide, tri-n-butyltin acetate, tri- -n-butyltin fluoride, among which a titanium-based catalyst may be preferred. The catalyst may be used in an amount of 0.01 to 1% by weight based on the total weight of the polyester and the polyether, more specifically 0.03 to 0.5% by weight.

Meanwhile, the method for producing a polyetherester copolymer according to an embodiment of the present invention is characterized in that after the polycondensation reaction (first polycondensation reaction) at the elevated temperature as described above, And may further optionally include a polymerization reaction.

When the second polycondensation reaction is further performed, it is preferable that the first and second polycondensation reactions are performed within the above-described polycondensation reaction time range. More specifically, % ≪ / RTI > to 50%, more particularly 20 to 30%. When performed under the above-mentioned conditions, a copolymer having a high molecular weight can be produced with higher efficiency without deteriorating color characteristics.

In the method for producing a copolymer according to an embodiment of the present invention, a poly (alkylene terephthalate) or a copolymer thereof may be used as the polyester. Specific examples thereof include poly (ethylene terephthalate), poly (butylene terephthalate), poly (trimethylene terephthalate), poly (pentylene terephthalate), poly (hexylene terephthalate) Or a copolymer thereof, and any one or a mixture of two or more of them may be used. Since the polyester forms a hard segment in the copolymer, poly (butylene terephthalate) capable of increasing the phase separation due to crystallization of the hard segment, among the above-mentioned compounds, is more preferably used .

The molecular weight of the poly (alkylene terephthalate) or the copolymer thereof is not particularly limited. However, considering the reaction time and productivity, the number average molecular weight is preferably 20,000 g / mol or more, more specifically 30,000 to 50,000 g / mol , And even more specifically from 40,000 to 47,000 g / mol.

Meanwhile, in the present invention, the number average molecular weight (Mn) is a polystyrene reduced molecular weight analyzed by gel permeation chromatography (GPC).

As the polyether, a polyether polyol compound may be used. Specific examples thereof include polytetramethylene ether glycol, polyethylene ether glycol, polypropylene ether glycol, polyhexamethylene ether glycol, or a copolymer of tetrahydrofuran and 3-alkyltetrahydrofuran, and either or both of them The above mixture may be used. Of these, polymethylene ether glycols can be more preferably used.

The molecular weight of the polyether polyol compound is not particularly limited. However, considering the influence on the crystallinity, hardness, reactivity and thermal characteristics, the number average molecular weight is preferably 500 to 2000 g / mol, more specifically 700 to 1500 g / mol, more specifically 1000 to 1200 g / mol.

The physical properties of the copolymer may vary depending on the content of the hard segment and the soft segment in the polyetherester copolymer or the molecular weight of the copolymer. Therefore, the amount of the polyester and the polyether to be used may be appropriately determined depending on the physical properties to be implemented. Specifically, when a polyether ester having thermal properties together with excellent elastic recovery properties is to be produced, the polyester and the polyester can be used in a weight ratio of 1: 4 to 4: 1. If the weight ratio is less than 1: 4, the elastic recovery property is deteriorated. If the weight ratio is more than 4: 1, the melting point is decreased to a great extent, and sufficient thermal characteristics are hardly obtained. More specifically, the polyester and polyester may be used in a weight ratio of 2: 1 to 4: 1.

Further, at the time of the above-mentioned condensation polymerization, one or more additives may be further added because of the improvement of the efficiency of condensation polymerization and the physical properties of the polyetherester copolymer to be produced.

Specifically, a method for increasing the melt strength of a polyetherester copolymer (for example, a method in which a polyol is added to a polyol such as glycerol, sorbitol, pentaerythritol, 1,1,4,4-tetrakis (hydroxymethyl) cyclohexane, Propane, pyromellitic acid, 1,1,2,2-ethanetetracarboxylic acid and the like), a matting agent (for example, TiO2, zinc sulfide or zinc oxide) for improving color characteristics, a colorant (for example, Antioxidants, photostabilizers, extenders, processing aids or viscosity enhancers, and the like can be given as examples of the antioxidant, antioxidant, antioxidant, antioxidant, antioxidant, , Any one or a mixture of two or more thereof may be used.

These additives can be used in an appropriate amount within a range that does not deteriorate the physical properties of the polyetherester copolymer to be produced, specifically 0.1 to 10% by weight based on the total amount of polyether and polyester have.

With the above-described production method, a polyether ester copolymer having an excellent color characteristic can be produced, which can minimize the amount of tVOC generated, and is relatively high in molecular weight in a short time.

Specifically, the polyetherester copolymer may have a number average molecular weight of 40,000 g / mol or more and a degree of polymerization of 130 to 140, and more specifically, a polyether in a copolymer, specifically, a PTMEG content of 30 to 40 wt% , A number average molecular weight of 40,000 g / mol or more, and a degree of polymerization of 130 to 140. Accordingly, the polyetherester copolymer produced by the above-described production method can be used in various fields such as automobiles, home appliances, building materials, IT, everyday articles, etc. Especially useful for the production of products requiring high molecular weight and white characteristics .

According to another embodiment of the present invention, there is provided a polyether ester copolymer produced by the above-mentioned production method and having a high molecular weight and excellent color characteristics, more specifically, a PBT-PTMEG copolymer, To provide a molded article.

Hereinafter, preferred embodiments of the present invention will be described in order to facilitate understanding of the present invention. However, the following examples are provided only for the purpose of easier understanding of the present invention, and the present invention is not limited thereto.

Example  One

PBT and PTMEG having a number average molecular weight (Mn) of about 40,000 g / mol were used as raw materials and about 500 ppm by weight of tetrabutyl titanate (TBT) was used as a catalyst. PTMEG copolymer was prepared. At this time, the amount of the raw material was changed to 350 g of PBT, 166 g of PTMEG, and 0.25 g of TBT, and the reaction temperature was changed as the reaction time elapsed as shown in Fig. The yield of the obtained PBT-PTMEG copolymer was 500 g, and the content of PTMEG in the copolymer was about 33% by weight. In addition, the gas generation amount was 16 g, and the volatilized gas was mainly BDO, and THF (tetrahydrofuran) and water were included. The operating pressure was set at 1 mbar.

Example  2, and Comparative Example  1 to 4

The PBT-PTMEG copolymer was prepared in the same manner as in Example 1, except that the reaction temperature was controlled according to the progress of the reaction time as shown in FIG.

Specifically, Comparative Example 1 is isothermal reaction at 250 占 폚, Comparative Example 2 is 240 占 폚, and Comparative Example 3 is isothermal reaction at 230 占 폚. In Example 1 and Comparative Example 4, the temperature is raised from 230 占 폚 to 250 占 폚, The isothermal temperature was maintained at 250 ° C, and the rate of temperature rise was 10 ° C / hr for Example 1 and 20 ° C / hr for Comparative Example 4, respectively. In Example 2, the temperature was raised from 230 占 폚 to 250 占 폚 at a heating rate of 8 占 폚 / hr. At this time, the operating pressure was equal to 1 mbar.

Experimental Example

The degree of polymerization (DPN), Mn, color, and total amount of THF in the polymerization system of the PBT-PTMEG copolymer prepared according to Examples 1 and 2 and Comparative Examples 1 to 4 were measured, Respectively.

The change in molecular weight with respect to the reaction time was observed, and the results are shown in Fig.

Operating temperature
(See Fig. 1) Mn (g / mol) DPN color THF Emission (g) Example 1 After raising the temperature from 230 占 폚 to 250 占 폚,
(Heating rate = 10 DEG C / hr) 42209 134 White 1.02 Example 2 230 ° C to 250 ° C
(Heating rate = 8 DEG C / hr) 40993 130 White 1.26 Comparative Example 1 Isothermal at 250 < 36499 116 yellow 1.71 Comparative Example 2 Isothermal at 240 < 40643 129 White 1.28 Comparative Example 3 Isothermal at 230 ° C 37811 120 White 1.02 Comparative Example 4 After raising the temperature from 230 占 폚 to 250 占 폚,
(Heating rate = 20 DEG C / hr) 38400 122 Light-yellow 1.44

As a result of the experiment, Examples 1 and 2, in which the reaction temperature was raised during the condensation polymerization, had a number average molecular weight of 40,000 g / mol or more and a high molecular weight, and exhibited excellent color characteristics, as compared with Comparative Examples 1 to 4 .

Specifically, in the case of Comparative Example 1, the initial reaction was the fastest, but after 2 hours, the molecular weight was smaller than in other operating conditions. It was also found that the color of the PBT-PTMEG copolymer produced was not good and the total amount of THF was also the highest. When the amount of THF generated is large, the tVOC of the PBT-PTMEG copolymer is usually high. At the temperature of 250 ° C, the condensation reaction was the fastest, while the temperature-dependent chain decomposition reaction and the THF conversion of BDO accelerated together, making it difficult to produce high molecular weight, high quality polymers. In the case of Comparative Example 3, the color of the copolymer produced was good and the amount of THF generated was the smallest, but the final molecular weight was the smallest for 2 and a half hours. The reaction time can be increased to obtain high molecular weight, but in such cases the productivity is significantly reduced and the color of the copolymer becomes yellowish. In the isothermal reaction, Comparative Example 2 (240 ° C) showed the highest molecular weight, good color, and a relatively small amount of THF.

In addition, in Comparative Example 4, since the chain decomposition reaction was increased due to an excessively rapid temperature rise, the molecular weight increase width decreased after 2 hours. As a result, the final molecular weight decreased and THF generation increased.

On the other hand, in Example 1, the copolymer having the highest molecular weight was produced as compared with Comparative Examples 1 to 4 and Example 2, although the initial reaction was slow. In addition, the color of the copolymer was good, and the amount of THF generated similarly to Comparative Example 3 showed excellent tVOC. This is because the initial reaction temperature was lowered to minimize the decomposition reaction of the terminal BDO and the terminal PTMEG in the step 2). The end-group BDO and end-group PTMEG are thermally decomposed to generate THF and form a new carboxylic acid group. At this stage, the final molecular weight decreases as the production of carboxylic acid increases. This is due to the lack of the terminal carboxylic acid, BDO and terminal PTMEG, which are capable of participating in the esterification reaction with the latter carboxylic acid. Example 1 increased the rate of condensation polymerization by increasing the temperature gradually while minimizing the production of carboxylic acid at a relatively low temperature in the initial stage of the reaction and then passing through the step 2) Molecular weight increase. The reaction was terminated at 250 ° C, but the color was prevented from becoming yellowish by short thermal history as compared with Comparative Example 1.

Further, in Example 2, the molecular weight was higher than that in Comparative Examples 1 to 4, and excellent color characteristics were exhibited. However, since the temperature increase rate was slower than in Example 1, the molecular weight was relatively lower than that in Example 1, Respectively. It can be seen from the results of Examples 1 and 2 and Comparative Example 4 that the effect of the temperature increase can be further improved by optimizing the heating rate during the condensation polymerization reaction.

Claims (14)

And polycondensation of the polyester and the polyether in a vacuum atmosphere,
Wherein the polycondensation reaction is carried out under a temperature elevation condition at a rate of 5 deg. C / 1 hr to 15 deg. C / 1 hr in a temperature range of 230 deg. C to 250 deg.
The method according to claim 1,
Wherein the polycondensation reaction is carried out under elevated temperature conditions at a rate of 10 占 폚 / 1 hr to 15 占 폚 / 1 hr.
The method according to claim 1,
Wherein the polycondensation reaction is carried out for a time of 2.5 hours or less.
The method according to claim 1,
Wherein the polycondensation reaction is carried out under a vacuum pressure of 1 mbar or less.
The method according to claim 1,
Wherein at least one catalyst selected from a titanium-based catalyst and a tin-based catalyst is further added during the condensation polymerization reaction.
The method according to claim 1,
And a second polycondensation step performed under an isothermal condition at an elevated temperature after the polycondensation reaction at the elevated temperature.
The method according to claim 6,
Wherein the second polycondensation reaction is performed for a time of 20% to 50% of the total polycondensation reaction time.
The method according to claim 1,
Wherein the polyester comprises a poly (alkylene terephthalate) having a number average molecular weight of 20,000 g / mol or more, or a copolymer thereof.
9. The method of claim 8,
The poly (alkylene terephthalate) may be selected from the group consisting of poly (ethylene terephthalate), poly (butylene terephthalate), poly (trimethylene terephthalate), poly (pentylene terephthalate) Heptyleneterephthalate), and copolymers thereof. ≪ Desc / Clms Page number 24 >
The method according to claim 1,
Wherein the polyether comprises a polyether polyol compound having a number average molecular weight of 500 to 2,000 g / mol.
11. The method of claim 10,
Wherein the polyether polyol compound is selected from the group consisting of polytetramethylene ether glycol, polyethylene ether glycol, polypropylene ether glycol, polyhexamethylene ether glycol, and copolymers of tetrahydrofuran and 3-alkyltetrahydrofuran. Ether ester copolymer.
The method according to claim 1,
Wherein the polyester and the polyester are used in a weight ratio of 1: 4 to 4: 1.
The method according to claim 1,
Wherein the polyetherester copolymer has a polyether content of 30 to 40% by weight, a number average molecular weight of 38000 g / mol or more, and a polymerization degree of 120 to 140 in a copolymer.
The method according to claim 1,
Wherein the polyetherester copolymer is a polybutylene terephthalate-polytetramethylene ether glycol copolymer.

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