KR101433898B1 - Polyether Ester Elastomer with Excellent Thermal Stability and Method of Preparing Same - Google Patents

Abstract

The polyetherester elastomer according to the present invention comprises a step of esterifying ethylene glycol and butylene glycol as raw materials of a hard segment with dimethyl terephthalate in the presence of a catalyst and reacting the esterified product with polyethylene glycol as a raw material of a soft segment, A heat stabilizer, a light stabilizer, and the like, followed by condensation polymerization. In the esterification step, ethylene glycol is preferably added in an amount of 1 to 50% by weight based on the entire low molecular weight diol component. In the condensation polymerization step, the polyethylene glycol is introduced into the reactor while the condensation polymerization reactor is maintained in a vacuum state. More specifically, the polyethylene glycol forming the soft segment is specifically produced to carry out the present invention even in a state of high vacuum, particularly at a reduced pressure of 1 mmHg or less as the reaction progresses as well as the pressure of the condensation polymerization reactor below the normal pressure at the initial stage of the reaction Lt; RTI ID = 0.0 > reactor. ≪ / RTI >

Description

TECHNICAL FIELD [0001] The present invention relates to a polyether ester elastomer having excellent thermal stability,

The present invention relates to polyetherester elastomers. More specifically, the present invention relates to a polyetherester elastomer excellent in thermal stability in a process of copolymerizing polyethylene ether ester with hard segment of ethylene glycol, butylene glycol, and dimethyl terephthalate as a soft segment, and a process for producing the same.

The elastomer has unique elastic properties and is used in many applications such as packaging containers, automobile interior materials and elastic fibers. In particular, in the case of thermoplastic polyester copolymers, the use amount thereof is increasing due to a wide range of elastic properties. Unlike rubber materials, which can not be recycled, elastomers are also easily recycled, and therefore their demand is greatly increased.

Thermoplastic elastomer (TPE) is a polymer having both of two different properties: thermoplastic, which can be reformed upon heating, and elastic properties of elastomer, a rubber-like polymer. The form of TPE is a kind of block copolymer, which consists of a hard segment block, which can generally exhibit thermoplastic characteristics, and a soft segment block, which can exhibit elastic properties of the elastomer.

It is already known that polyether ester copolymers having a polybutylene terephthalate polyester as a hard segment and a polybutylene ether ester as a soft segment exhibit excellent elastic properties. In order to lower the production cost, a polyethylene ether ester Is also used as a soft segment.

U.S. Patent No. 3,023,192 discloses hard segment / soft segment copolymerized polyesters and elastomers made therefrom. The hard segment / soft segment copolymerized polyester is prepared from a dihydroxy compound selected from (1) a dicarboxylic acid or ester forming derivative, (2) a polyethylene glycol ether, and (3) a bisphenol and a lower aliphatic glycol. Examples of the polyether used as a soft segment together with polyethylene glycol include polypropylene glycol, polytetramethylene glycol, polyhexamethylene glycol and the like, and a polyether having a molecular weight of about 350 to 6,000 is used.

U.S. Patent No. 4,937,314 discloses a thermoplastic polyetherester elastomer comprising at least 70 parts by weight of a soft segment derived from poly (alkylene oxide) glycol and terephthalic acid. The hard segment constitutes 10 to 30 parts by weight of the elastomer, and the poly (1,3-propylene terephthalate) in the hard segments is 95 to 100 parts by weight. The molecular weight of the poly (alkylene oxide) glycol is from about 1,500 to about 5,000 and the carbon to oxygen ratio is from 2 to 4.3.

Thermoplastic elastomers based on those exemplified in the prior art are soft segments mainly composed of polytetramethylene glycol ethers, copolymers of tetrahydrofuran and 3-alkyltetrahydrofuran, polyethylene glycol ethers, polytrimethylene glycol ethers and copolymers thereof Lt; / RTI > The melting point and physical properties of these copolymers are determined by the molecular weight and composition ratio of the polyalkylene glycol ether used as the soft segment. When a polyalkylene glycol ether having a high molecular weight is used to develop strong physical and elastic properties, the melting point of the polyalkylene glycol ether can not be applied to a process requiring a low melting point manufacturing process. When the polyethylene glycol ether is formed into a soft segment, when the content of the soft segment is 20 wt% or more, the thermal stability sharply drops.

In order to solve the above problems, the present inventors have come to develop the present invention, which is a new method for producing a polyetherester elastomer.

An object of the present invention is to provide a novel process for producing a polyetherester elastomer which can have various melting points by controlling the melting point of the polyetherester elastomer.

Another object of the present invention is to provide a polyetherester elastomer excellent in thermal stability by using polyethylene glycol ether as a soft segment and a process for producing the same.

It is still another object of the present invention to provide a polyetherester elastomer having a short reaction time by introducing polyethylene glycol into a reactor in a state in which a condensation polymerization reactor is maintained in a vacuum state, .

These and other objects of the present invention can be achieved by the present invention which is described in detail below.

The polyetherester elastomer according to the present invention comprises a step of esterifying ethylene glycol and butylene glycol as raw materials of a hard segment with dimethyl terephthalate in the presence of a catalyst and reacting the esterified product with polyethylene glycol as a raw material of a soft segment, A heat stabilizer, a light stabilizer, and the like, followed by condensation polymerization.

In the esterification step, ethylene glycol is preferably added in an amount of 1 to 50% by weight based on the entire low molecular weight diol component.

In the condensation polymerization step, the polyethylene glycol is introduced into the reactor while the condensation polymerization reactor is maintained in a vacuum state. More specifically, the polyethylene glycol forming the soft segment is specifically produced to carry out the present invention even in a state of high vacuum, particularly at a reduced pressure of 1 mmHg or less as the reaction progresses as well as the pressure of the condensation polymerization reactor below the normal pressure at the initial stage of the reaction Lt; RTI ID = 0.0 > reactor. ≪ / RTI >

Examples of the catalyst used in the esterification reaction step include zinc acetate, sodium acetate, magnesium acetate, tetranormalbutoxy titanate, tetraisopropyl titanate, titanium oxide / silicon oxide microcopolymer, and nano titanate. The esterification reaction catalyst is preferably used in a range of 50 to 1000 ppm based on 100 parts by weight of the polyetherester elastomer.

Examples of the polymerization catalyst used in the condensation polymerization step include antimony catalysts such as antimony trioxide and antimony acetate or titanium catalysts such as tetranormalbutoxy titanate, tetraisopropyl titanate, titanium oxide / silica oxide microcopolymer and nano titanate, (Ti) -based catalyst is preferably used. The condensation polymerization catalyst is preferably used in a range of 50 to 2000 ppm based on 100 parts by weight of the elastomer.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings.

The present invention provides a polyetherester elastomer having various melting points by controlling the melting point of a polyetherester elastomer and having polyethylene glycol ether as a soft segment and having excellent thermal stability. In a state where the condensation polymerization reactor is maintained in a vacuum state The present invention has the effect of providing a process for producing a polyetherester elastomer wherein the reaction time is shortened by at least 1 hour as compared with the previous process by introducing polyethylene glycol into the reactor.

FIG. 1 is a schematic cross-sectional view of a polyethylene glycol input facility specially designed for introducing polyethylene glycol into a reactor in a state where the condensation polymerization reactor is maintained in a vacuum state in the present invention.

The present invention relates to a polyetherester elastomer. In the process of copolymerizing a polyethylene ether ester with a soft segment with ethylene glycol, butylene glycol, and dimethyl terephthalate in a hard segment, the condensation polymerization reactor is maintained in a vacuum state (PEG) into the reactor to shorten the reaction time and, as a result, to produce a polyetherester elastomer excellent in thermal stability.

The polyetherester elastomer according to the present invention comprises a step of esterifying ethylene glycol and butylene glycol as raw materials of a hard segment with dimethyl terephthalate in the presence of a catalyst and reacting the esterified product with polyethylene glycol as a raw material of a soft segment, A heat stabilizer, a light stabilizer, and the like, followed by condensation polymerization.

First, the esterification reaction step will be described as follows.

Ethylene glycol, butylene glycol, and dimethyl terephthalate are esterified to form a hard segment of the polyetherester elastomer. 1 to 50 parts by weight of ethylene glycol and 50 to 99 parts by weight of butylene glycol are added together with 100 parts by weight of a low molecular weight diol component to an heat resistant pressure vessel together with an esterification reaction catalyst and subjected to an esterification reaction to prepare an oligomer solution.

Conventional polyetherester elastomers use conventional aromatic or aliphatic dicarboxylic acids such as isophthalic acid, adipic acid and succinic acid as a copolymerization raw material in order to control the melting point, while in the present invention, the ethylene glycol is used as a diol component, It has an advantage that various melting points required in the molding process of the final product can be easily controlled while maintaining the elastic properties and physical characteristics as important characteristics. However, when the amount of ethylene glycol added is less than 1 part by weight, the desired melting point is not controlled. When the amount of ethylene glycol is more than 50 parts by weight, elastic properties and physical properties of the elastomer deteriorate. The melting point can be controlled by maintaining the physical and elastic properties of the elastomer according to the charging ratio of ethylene glycol.

Examples of the catalyst used in the esterification step include acetic acid based catalysts such as zinc acetate, sodium acetate, and magnesium acetate, and organic bases such as tetranormalbutoxy titanate, tetraisopropyl titanate, titanium oxide / silica oxide microcopolymer, Based catalyst, and these catalysts can be used alone or in combination of two or more. The esterification catalyst may be added in an amount of 50 to 1000 ppm, preferably 200 to 700 ppm, based on 100 parts by weight of the polyetherester elastomer. If the amount of the catalyst is insufficient, the esterification reaction rate is slowed and the thermal stability of the elastomer deteriorates.

The reaction temperature of the heat-resistant, pressure-resistant vessel in which the esterification reaction proceeds in order to distill methanol produced as a by-product is in the range of 100 to 240 캜, preferably in the range of 150 to 210 캜. When the reaction is carried out at a reaction temperature of 240 ° C or higher for a long period of time in the presence of an esterification reaction catalyst, an excess amount of diethylene glycol is produced by dehydration reaction of ethylene glycol. The production of diethylene glycol may result in a deterioration of the physical properties of the final elastomer.

When the esterification reaction proceeds, condensation polymerization proceeds.

The oligomer solution obtained by the esterification reaction and the soft segment polyethylene glycol, the condensation polymerization catalyst, the heat stabilizer and the photo-stabilizer were introduced into a pressure-resistant / heat-resistant reactor capable of vacuum decompression, and then subjected to a pressure of 760 to 1 Torr and a pressure of 200 to 270 ° C After the excess ethylene glycol and butylene glycol are distilled off at the temperature, the condensation polymerization is completed under a high vacuum of 1 mmHg or lower in the final degree of vacuum to prepare the thermoplastic elastomer.

Conventionally, in order to feed polyethylene glycol, the vacuum state of the condensation polymerization reactor was reduced to a normal pressure state, then polyethylene glycol was added, and the reaction was further evacuated to a vacuum state. In this case, the reaction time is lengthened and the reaction time is prolonged, resulting in a problem that the thermal stability of the finally produced chip is lowered. However, in the present invention, polyethylene glycol can be introduced under the atmospheric pressure at the initial stage of the reaction, or in a vacuum state in the course of the reaction, without returning the pressure of the reaction system to normal pressure using the apparatus of FIG. The polyethylene glycol preferably has a molecular weight in the range of 400 to 20,000, and these polyethylene glycol may be used singly or in a mixture of two or more.

FIG. 1 is a schematic cross-sectional view of a polyethylene glycol input facility specially designed for introducing polyethylene glycol into a reactor in a state where the condensation polymerization reactor is maintained in a vacuum state in the present invention. The polyethylene glycol is introduced into the facility through the upper valve. The facility is designed to heat the polyethylene glycol with a band heater and a thermal insulation material, and the polyethylene glycol is fed into the reactor through the lower valve. Using the equipment shown in FIG. 1, polyethylene glycol can be fed into the reactor at a reduced pressure of from 760 Torr at the initial stage of condensation polymerization to 1 Torr or less at high vacuum without returning the pressure of the reaction system to normal pressure.

Examples of the polycondensation catalyst include antimony catalysts such as antimony trioxide and antimony acetate or titanium catalysts such as tetranormalbutoxy titanate, tetraisopropyl titanate, titanium oxide / silica oxide microcopolymer, and nano titanate. Is preferably used. The polycondensation catalyst is added in the range of 50 to 2000 ppm based on 100 parts by weight of the elastomer, preferably in the range of 300 to 1200 ppm. If the amount of the catalyst is insufficient, the rate of the condensation polymerization becomes slow and the elastomer having high physical properties can not be obtained, and the thermal stability of the elastomer is deteriorated.

The process for producing a polyetherester elastomer having a polyethylene glycol ether as a soft segment according to the present invention is characterized in that since the ethylene glycol ether ester and the butylene glycol ether ester are copolymerized in the hard segment, the copolymerization ratio is adjusted to maintain the physical and elastic properties It is possible to improve the thermal stability of the elastomer produced by reducing the thermal history of the inserted soft segment during the polymerization process by introducing a soft segment which is insufficient in thermal stability during the polycondensation reaction.

The elastomer recycled according to the present invention can be made into various types of extrudates. In addition, the elastomer produced according to the present invention may be made of fibers. The in-situ spinning method or the combined spinning method can be used as a method of producing fibers with the elastomer of the present invention. The in-situ spinning method is a spinning method using an elastomer as a single component. In the spinning method, an elastomer is spin-spinned with another fiber forming component to produce a conjugate fiber. The composite fiber may be in the form of a side-by-side or in the form of a sheath-core having the elastomer of the present invention as a sheath component.

The features and other advantages of the present invention will become more apparent from the following description of exemplary embodiments with reference to the attached drawings.

Example  One

2.7 kg of ethylene glycol, 4.1 kg of butylene glycol, 13.3 kg of dimethyl terephthalate, and 13 g of tetranormalbutoxy titanate were added to a stirrerable 100 L reactor, and the mixture was heated and stirred at an initial temperature of 130 캜, It is confirmed that the phthalate is melted and dissolved in the low-molecular-weight diol component. After confirming that the dimethyl terephthalate was melted and dissolved, the reaction was continued for 4 hours by gradually heating and heating the internal temperature of the reactor to 205 ° C, stirring the methanol, and distilling off the methanol generated as a by-product to remove the ester from the reactor .

The oligomer solution was added to a heat resistant, internal pressure 100 liter reactor capable of vacuum decompression and stirring, and then 10.9 kg of polyethylene glycol, 100 g of a thermal stabilizer (Irganox 1010), 50 g of a light stabilizer (Tinuvin 770DF) 23 g of cittaninate are added. Condensation polymerization The condensation polymerization was completed in a high vacuum at a final temperature of 250 ° C and a final vacuum degree of 1 mmHg or less by gradually reducing pressure and heating to prepare a thermoplastic elastomer. The properties of the obtained thermoplastic elastomer were measured. The measurement results are shown in Table 1.

Example  2-6 and Comparative Example  1-2

The procedure of Example 1 was repeated except that the charging ratio of ethylene glycol, the molecular weight of polyethylene glycol, the order of introduction of polyethylene glycol, and the type of polyalkylene glycol were changed as shown in Table 1, and the order of introduction of polyethylene glycol was changed.

Example 1-4 showed changes in the physical properties such as the melting point of the thermoplastic elastomer according to the change of the charging ratio of ethylene glycol by changing the charging ratio of ethylene glycol and butylene glycol. In Example 5-6, the molecular weight of the polyethylene glycol was changed, The physical and elastic properties of the thermoplastic elastomer were determined according to the molecular weight of the thermoplastic elastomer.

Comparative Example 1 confirmed the change in the physical properties and elastic properties of the thermoplastic elastomer using polybutylene glycol as an expensive raw material instead of polyethylene glycol as a soft segment. In Comparative Example 2, the order of introduction of polyethylene glycol was changed to Example 1 -6 and Comparative Example 1, the physical properties and elastic properties of the thermoplastic elastomer according to the order of introduction of polyethylene glycol were compared.

The evaluation items shown in the above Examples and Comparative Examples were measured as follows.

Melting point: Measured using a Perkin Elmer (DSC-Diamond) and when no heat absorption peak is present (no melting point), a dynamic thermal characterizer (Perkin Elmer, DMA-7, TMA mode) The softening behavior was measured.

Intrinsic Viscosity (IV): Copolymer polyester was dissolved in phenol / tetrachloroethane (weight ratio 50/50) to make a 0.5 wt.% Solution and then measured at 35 ° C with a Uvold viscometer.

Tensile strength: Measured by Instron 4467 Series.

Tensile elongation: Measured with Instron 4467 Series.

Hardness: Measured with Handpi's Showa D durometer.

Heat stability: The specimens for tensile strength analysis were stored in an oven at 150 ° C for 2 weeks, and the tensile strength of the specimens was measured before and after heating.

* Dimethyl terephthalate, a component of the hard segment, is excluded from the table above.

As can be seen from the results of Table 1, it can be seen that the melting point of the elastomer is lowered by 1 ° C as the loading ratio of ethylene glycol is increased by 1 mol%, and the melting point of the thermoplastic elastomer And the melting point of ethylene glycol can be defined by the following equation.

Melting point (占 폚) of the elastomer = 213 - 1.02 x ethylene glycol composition (mol%)

The present invention, in which ethylene glycol is used as a diol component in comparison with a conventional method in which an aromatic or aliphatic dicarboxylic acid such as isophthalic acid, adipic acid or succinic acid is used as a copolymerization raw material in order to control the melting point of an elastomer, It is possible to easily control various melting points required in the molding process of the final product while maintaining elasticity and physical properties as characteristics. When the amount of ethylene glycol is less than 1 part by weight, the desired melting point is not controlled. When the amount is more than 50 parts by weight, the elasticity and physical properties of the elastomer deteriorate.

It is also possible to produce a thermoplastic elastomer having the same physical properties and elastic properties by using polyethylene glycol instead of expensive polybutylene glycol. The introduction sequence of the polyethylene glycol is limited to the condensation polymerization reaction, Comparative Example 2 It can be seen that it is possible to produce a thermoplastic elastomer excellent in heat resistance stability.

Claims (8)

Esterifying ethylene glycol and butylene glycol, which are raw materials of the hard segment, with dimethyl terephthalate under a catalyst; And
Introducing a polymerization catalyst, a heat stabilizer, and a light stabilizer together with polyethylene glycol as a raw material of the soft segment into the esterification reaction product to perform condensation polymerization;
≪ RTI ID = 0.0 > 1, < / RTI >
The process for producing a polyetherester elastomer according to claim 1, wherein ethylene glycol is added in an amount of 1 to 50% by weight based on the entire low molecular weight diol component in the esterification reaction step.
3. The method according to claim 1 or 2, wherein, in the condensation polymerization step, the polyethylene glycol forming the soft segment is subjected to a condensation reaction at a pressure lower than the normal pressure at the initial stage of the reaction, Of the polyetherester elastomer.
4. The method of claim 3, wherein the catalyst used in the esterification step is selected from the group consisting of zinc acetate, sodium acetate, magnesium acetate, tetranormalbutoxy titanate, tetraisopropyl titanate, titanium oxide / silicon oxide microcopolymer, Wherein the polyetherester elastomer is used in an amount of 50 to 1000 ppm based on 100 parts by weight of the polyetherester elastomer.
4. The method of claim 3, wherein the polymerization catalyst used in the condensation polymerization step is selected from the group consisting of antimony trioxide, antimony acetate, tetranormalbutoxy titanate, tetraisopropyl titanate, titanium oxide / silica oxide microcopolymer, And is used in a range of 50 to 2000 ppm based on 100 parts by weight of the elastomer.
4. The process for producing a polyetherester elastomer according to claim 3, wherein the polyethylene glycol has a molecular weight of 400 to 20,000.
Esterifying ethylene glycol and butylene glycol, which are raw materials of the hard segment, with dimethyl terephthalate under a catalyst; And
Introducing a polymerization catalyst, a heat stabilizer, and a light stabilizer together with polyethylene glycol as a raw material of the soft segment into the esterification reaction product to perform condensation polymerization;
Lt; / RTI >
In the polycondensation step, the polyethylene glycol forming the soft segment is introduced into the reactor at a reduced pressure of not more than 1 mmHg as the reaction progresses as well as the pressure of the condensation polymerization reactor below the normal pressure at the initial stage of the reaction,
Wherein the resulting polyetherester elastomer satisfies the following relational expression in terms of the melting point and the composition of ethylene glycol:
Melting point (占 폚) of elastomer = 213 - 1.02 x ethylene glycol composition (mol%).
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