KR20240107785A - Polyester resin and preparation method thereof - Google Patents

Abstract

The present invention relates to a polyester resin that can be suitably used in products that require high heat resistance due to its high glass transition temperature, and a method for manufacturing the same.

Description

Polyester resin and its manufacturing method {POLYESTER RESIN AND PREPARATION METHOD THEREOF}

The present invention relates to a polyester resin exhibiting high heat resistance and a method for producing the same.

Polyester resin has excellent mechanical strength, chemical stability, and gas barrier properties, and is widely used as a material for packaging containers, fibers, sheets, and films. A representative polyester resin is polyethylene terephthalate (PET), which is manufactured by polymerizing terephthalic acid and ethylene glycol. However, PET is crystalline, has poor formability, and has limitations in improving heat resistance.

In order to compensate for the shortcomings of PET, glycol-modified polyethylene terephthalate (PETG), which further contains 1,4-cyclohexanedimethanol (CHDM) as a diol component in addition to ethylene glycol, was developed. PETG has higher thermal and chemical stability and impact strength than PET due to CHDM, has excellent processability, and is non-crystalline, so transparent products can be produced without whitening due to crystallization. However, PETG has a glass transition temperature (Tg) of 80 to 88 ℃, making it difficult to use in fields that require high heat resistance.

The purpose of the present invention is to provide a new polyester resin with excellent heat resistance and a method for producing the same.

Accordingly, according to one embodiment of the present invention, a polyester resin comprising a dicarboxylic acid repeating unit and a diol repeating unit, wherein the diol repeating unit is 6,6'-dihydroxyethoxy-4,4,4 A polyester resin comprising a repeating unit derived from ',4',7,7'-hexamethyl-2,2'-spirobicroman is provided.

Additionally, according to another embodiment of the present invention, a dicarboxylic acid component; A diol component containing only 6,6'-dihydroxyethoxy-4,4,4',4',7,7'-hexamethyl-2,2'-spirobichromene; and mixing a polymerization catalyst and melting it by raising the temperature, and polymerizing the molten mixture at a pressure of 10 torr or less and a temperature of 160°C to 200°C.

Additionally, according to another embodiment of the present invention, a dicarboxylic acid component; and a diol component containing only 6,6'-dihydroxyethoxy-4,4,4',4',7,7'-hexamethyl-2,2'-spirobichromene, in the presence of a polymerization catalyst, at 700 °C. at a pressure of 800 torr and a temperature of 200 to 300 °C. A method for producing a polyester resin is provided, including carrying out an esterification reaction or transesterification reaction, and subjecting the reaction mixture to a condensation polymerization reaction at a pressure of 0.1 to 400 torr and a temperature of 240 to 300 ° C.

The polyester resin of the present invention is a repeating unit derived from 6,6'-dihydroxyethoxy-4,4,4',4',7,7'-hexamethyl-2,2'-spirobichroman It exhibits a high glass transition temperature, and therefore can be suitably used in fields that require high heat resistance.

Figure 1 shows the chemical structure of DHS diol prepared as a preparation example confirmed through ¹ H-NMR.

The terminology used herein is for the purpose of describing exemplary embodiments only and is not intended to limit the invention. Singular expressions include plural expressions unless the context clearly dictates otherwise.

In this specification, terms such as “comprise,” “comprise,” or “have” are intended to designate the presence of implemented features, steps, components, or a combination thereof, and are intended to indicate the presence of one or more other features or steps, It should be understood that the existence or addition possibility of components or combinations thereof is not excluded in advance.

Since the present invention can be subject to various changes and can take various forms, specific embodiments will be illustrated and described in detail below. However, this is not intended to limit the present invention to a specific disclosed form, and should be understood to include all changes, equivalents, and substitutes included in the spirit and technical scope of the present invention.

Hereinafter, the present invention will be described in detail.

polyester resin

According to one embodiment of the present invention, a polyester resin comprising a dicarboxylic acid repeating unit and a diol repeating unit, wherein the diol repeating unit is 6,6'-dihydroxyethoxy-4,4,4', A polyester resin comprising repeating units derived from 4',7,7'-hexamethyl-2,2'-spirobicroman is provided.

The present inventors tried to develop a polyester resin that can exhibit excellent heat resistance properties at the level of polycarbonate, and as a result, 6,6'-dihydroxyethoxy-4,4,4 was added as a diol repeating unit to the polyester resin. The present invention was completed by confirming that when a repeating unit derived from ',4',7,7'-hexamethyl-2,2'-spirobichromene was included, the glass transition temperature increased significantly, showing excellent heat resistance properties. did.

6,6'-dihydroxyethoxy-4,4,4',4',7,7'-hexamethyl-2,2'-spirobichroman (6,6'-dihydroxyethoxy-4,4, 4',4',7,7'-hexamethyl-2,2'- spirobichroman, DHS diol) is a compound having the structure of Formula 1 below:

[Formula 1]

The repeating unit derived from the DHS diol exhibits steric hindrance due to the spirobichromene ring, and the rotation of the bond is not free, thereby increasing the rigidity of the polymer chain. . As a result, the polyester resin containing DHS diol exhibits a significantly improved glass transition temperature (Tg) compared to existing polyester resins such as PETG, and is therefore suitable for use in fields requiring high heat resistance, such as heat-resistant containers for food and construction. It can be suitably used as a material for protective sheets, protective cases for electronic products, or parts for various home appliances.

In addition, the diol of the spirobichroman structure has excellent reactivity as a primary alcohol and has the advantage of having an excellent degree of polymerization, that is, a high molecular weight of the polymer.

The repeating unit derived from the DHS diol is 1.0 mol% or more, or 3.0 mol% or more, or 5.0 mol% or more, and 15.0 mol% or less, or 13.0 mol%, out of the total 100 mol% of diol-derived repeating units contained in the polyester resin. It may be preferable to include % or less, or 10.0 mol% or less. If the repeating unit derived from DHS diol among the diol repeating units is less than 1 mol%, sufficient glass transition temperature improvement effect may not be obtained, and if it exceeds 15.0 mol%, there may be a problem of low molecular weight due to low polymerization degree.

The polyester resin may further include repeating units derived from various diol compounds commonly used in the production of polyester resins in addition to repeating units derived from the DHS diol as diol repeating units.

For example, the polyester resin may include a repeating unit derived from one or more aliphatic diols having 2 to 20 carbon atoms, preferably 2 to 12 carbon atoms. Examples of the aliphatic diol include ethylene glycol, diethylene glycol, triethylene glycol, 1,3-propanediol, 1,4-butanediol, 2,3-butanediol, 1,3-butanediol, pentanediol (1,5- pentanediol, etc.), hexanediol (1,6-hexanediol, etc.), neopentyl glycol (2,2-dimethyl-1,3-propanediol), 1,2-cyclohexanediol, 1,4-cyclohexanediol , 1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, tetramethylcyclobutanediol, etc., but is not limited thereto. Additionally, 3,9-bis(1,1-dimethyl-2-hydroxyethyl)-2,4,8,10-tetraoxaspiro[5,5]undecane may be used as the diol monomer, but is not limited thereto. That is not the case.

Specifically, the diol repeating unit of the polyester resin is a repeating unit derived from ethylene glycol (EG), a repeating unit derived from 1,4-cyclohexane dimethanol (CHDM) and 3,9-bis(1,1-dimethyl-2-hydroxyethyl)-2,4,8,10-tetraoxaspiro[5,5]undecane (3,9-Bis(1,1-dimethyl It may further include one or more from the group consisting of repeating units derived from -2-hydroxyethyl)-2,4,8,10-tetraoxaspiro[5.5]undecane (BHT).

The repeating unit derived from ethylene glycol may be included in 5.0 mol% or more, 7.0 mol% or more, or 10.0 mol% or more, and 55.0 mol% or less, 30.0 mol% or less, or 23.0 mol% or less of 100 mol% of the diol repeating units. You can.

In addition, the repeating unit derived from 1,4-cyclohexanedimethanol is 10.0 mol% or more, 30.0 mol% or more, or 45.0 mol% or more, and 65.0 mol% or less, 60.0 mol% or less, out of 100 mol% of diol repeating units. , or may be included in an amount of 55.0 mol% or less.

In addition, the repeating unit derived from 3,9-bis(1,1-dimethyl-2-hydroxyethyl)-2,4,8,10-tetraoxaspiro[5,5]undecane is a diol repeating unit 100 Of the mole percent, it may be included at 10.0 mol% or more, 13.0 mol% or more, or 15.0 mol% or more, but at 30.0 mol% or less, 25.0 mol% or less, or 20.0 mol% or less.

If the ethylene glycol content is too low, the polymer may become brittle, and if it is too high, the effect of increasing the glass transition temperature may be minimal. If the content of 1,4-cyclohexanedimethanol is too low, there may be a problem of low molecular weight due to low degree of polymerization, and if it is too high, the polymer may become opaque and brittle due to high crystallinity. If the content of 3,9-bis(1,1-dimethyl-2-hydroxyethyl)-2,4,8,10-tetraoxaspiro[5,5]undecane is too low, the effect of increasing the glass transition temperature is reduced. There may be a problem that it becomes insignificant and the degree of polymerization decreases, and if it is too high, crystallization occurs and the polymer does not melt even at high temperatures, making polymerization impossible.

When the repeating unit derived from BHT is included, the molecular weight of polymerized PETG increases. In addition, when a repeating unit derived from BHT is included, the rigidity of the polymer chain is further improved and higher heat resistance characteristics can be secured. However, if too many repeating units derived from BHT are included, there may be a problem of solidification. In particular, when PETG is manufactured using a production method consisting of transesterification reaction and condensation polymerization, a problem may occur in which the product of the transesterification reaction step does not dissolve. Accordingly, it is preferred that repeat units derived from BHT are included within the ranges described above.

In a preferred embodiment, 100 mol% of the diol repeating unit of the polyester resin includes 1.0 to 15.0 mol% of the repeating unit derived from DHS diol, 5.0 to 55.0 mol% of the repeating unit derived from ethylene glycol, and 1,4- 10.0 to 65.0 mol% of repeating units derived from cyclohexanedimethanol, and the 3,9-bis(1,1-dimethyl-2-hydroxyethyl)-2,4,8,10-tetraoxaspiro[5, 5] may contain 10.0 to 30.0 mol% of repeating units derived from undecane.

The dicarboxylic acid repeating unit of the polyester resin refers to a repeating unit derived from dicarboxylic acid and/or its derivatives. Derivatives of the dicarboxylic acid include alkyl esters of dicarboxylic acid (lower alkyl esters with 1 to 4 carbon atoms such as monomethyl, monoethyl, dimethyl, diethyl, or dibutyl ester) and acid anhydrides of dicarboxylic acid ( acid anhydride), etc.

The polyester resin according to one embodiment of the present invention may include a repeating unit derived from terephthalic acid or a derivative thereof as a dicarboxylic acid repeating unit. At this time, the content of the repeating unit derived from terephthalic acid among 100 mol% of the dicarboxylic acid repeating unit is 50 mol% or more, 60 mol% or more, or 70 mol% or more, and is 100 mol% or less, 90 mol% or less, Alternatively, it may be 80 mol% or less. If the content of repeating units derived from terephthalic acid or its derivatives among dicarboxylic acid repeating units is too small (less than 50 mol%), the physical properties such as heat resistance, chemical resistance, and weather resistance of the polyester resin may be reduced.

Meanwhile, the dicarboxylic acid repeating unit may further include repeating units derived from other aromatic dicarboxylic acids, aliphatic dicarboxylic acids, or derivatives thereof, in addition to repeating units derived from terephthalic acid or derivatives thereof.

Examples of the aromatic dicarboxylic acids include naphthalenedicarboxylic acids such as phthalic acid, isophthalic acid, and 2,6-naphthalenedicarboxylic acid, diphenyl dicarboxylic acid, and 4,4'-stilbendicarboxylic acid; 2,5-furandicarboxylic acid, 2,5-thiophenedicarboxylic acid, etc. are mentioned.

Examples of the aliphatic dicarboxylic acids include cyclohexanedicarboxylic acids such as 1,4-cyclohexanedicarboxylic acid and 1,3-cyclohexanedicarboxylic acid, sebacic acid, succinic acid, isodecylsuccinic acid, and maleic acid. , fumaric acid, adipic acid, glutaric acid, and azelaic acid.

The total content of repeating units derived from the other aromatic dicarboxylic acids, aliphatic dicarboxylic acids, or derivatives thereof is less than 50 mol%, 40 mol% or less, out of the total 100 mol% of dicarboxylic acid repeating units, or It may be 30 mol% or less, 0 mol% or more, 10 mol% or more, or 20 mol% or more.

The molar ratio of the dicarboxylic acid repeating unit and the diol repeating unit of the polyester resin is not particularly limited, but may range from 1:1 to 1:3, or 1:1 to 1:2, for example.

The polyester resin described above includes a repeating unit derived from DHS diol as a diol repeating unit, and exhibits improved heat resistance compared to existing polyester resins. Specifically, the glass transition temperature (Tg) of the polyester resin according to one embodiment of the present invention is 95 ℃ or higher, 100 ℃ or higher, or 110 ℃ or higher, and 130 ℃ or lower, 125 ℃ or lower, or 120 ℃ or lower. , It exhibits excellent heat resistance properties comparable to that of polycarbonate. Accordingly, the polyester resin can be suitably used in fields that require high heat resistance.

The method for measuring the glass transition temperature of the polyester resin is explained in detail in the examples below.

Manufacturing method of polyester resin

According to one embodiment of the present invention, a method for producing the polyester resin is provided.

Specifically, the polyester resin includes a dicarboxylic acid component; A diol component including 6,6'-dihydroxyethoxy-4,4,4',4',7,7'-hexamethyl-2,2'-spirobichroman (DHS diol); and preparing a molten mixture of a polymerization catalyst, and polymerizing the molten mixture at a pressure of 10 torr or less and a temperature of 160°C to 200°C.

The melt polymerization is performed as a one-step reaction without distinction between esterification reaction and condensation polymerization reaction, can be performed using a small amount of monomer, and can be more effectively used when producing low molecular weight polyester resin.

For the melt polymerization, the dicarboxylic acid component, diol component, and polymerization catalyst are first mixed and then melted by raising the temperature.

The dicarboxylic acid component is dicarboxylic acid, its alkyl ester (lower alkyl ester with 1 to 4 carbon atoms, such as monomethyl, monoethyl, dimethyl, diethyl, or dibutyl ester), and/or their It is used to include acid anhydride. The dicarboxylic acid component reacts with the diol component to form a dicarboxylic acid repeating unit.

The dicarboxylic acid component is 50 mol% or more, 60 mol% or more, or 70 mol% or more of terephthalic acid and/or its derivatives out of 100 mol%, and 100 mol% or less, 90 mol% or less, or 80 mol% or less. and may include the remaining aromatic dicarboxylic acids, aliphatic dicarboxylic acids, or derivatives thereof as described above.

The diol component includes DHS diol, the content of which is 1 mol% or more, 10 mol% or more, or 15 mol% or more, and 50 mol% or less, 35 mol% or less, based on 100 mol% of the diol component. Alternatively, it may be 20 mol% or less.

Additionally, the diol component may include the various diol compounds described above in addition to DHS diol. Specifically, the diol component includes ethylene glycol, 1,4-cyclohexanedimethanol, and 3,9-bis(1,1-dimethyl-2-hydroxyethyl)-2,4,8,10- in addition to DHS diol. It may further include one or more species selected from the group consisting of tetraoxaspiro[5,5]undecane.

The ethylene glycol may be included in 5 mol% or more, 10 mol% or more, 15 mol% or more, or 20 mol% or more, and 40 mol% or less, 35 mol% or less, or 30 mol% or less in 100 mol% of the diol component. there is.

The 1,4-cyclohexanedimethanol is 5 mol% or more, 10 mol% or more, 15 mol% or more, or 20 mol% or more, and 40 mol% or less, 35 mol% or less, or 30 mol% or more of 100 mol% of the diol component. It may be contained in mole percent or less.

The 3,9-bis(1,1-dimethyl-2-hydroxyethyl)-2,4,8,10-tetraoxaspiro[5,5]undecane (BHT) is 5 moles out of 100 mol% of the diol component. % or more, 10 mol% or more, 15 mol% or more, or 20 mol% or more, but may be included in less than 35 mol%, or 30 mol% or less.

When the repeating unit derived from BHT is included, the molecular weight of polymerized PETG increases. In addition, when a repeating unit derived from BHT is included, the rigidity of the polymer chain is further improved and higher heat resistance characteristics can be secured. However, if too many repeating units derived from BHT are included, there may be a problem of solidification. In particular, when PETG is manufactured using a production method consisting of transesterification reaction and condensation polymerization, a problem may occur in which the product of the transesterification reaction step does not dissolve. Accordingly, it is preferred that the BHT diol monomer is included within the range described above.

In one embodiment, 100 mol% of the diol component includes 5.0 mol% to 30.0 mol% of DHS diol, 10.0 to 30.0 mol% of 1,4-cyclohexanedimethanol, 10.0 to 30.0 mol% of BHT, and the balance of ethylene glycol. It can be composed of:

The molar ratio of the dicarboxylic acid component and the diol component may be in the range of 1:1 to 1:3, preferably 1:1 to 1:2. If the molar ratio of the dicarboxylic acid component and the diol component is less than 1:1, unreacted acid components may remain during the polymerization reaction, which may reduce the transparency of the polyester resin. If it exceeds 1:3, the terminals may have hydroxyl groups. Since it exists only as a polymer and it is difficult to obtain a high molecular weight polymer, it is desirable to satisfy the above range.

The polymerization catalyst may include titanium (Ti), aluminum (Al), tin (Sn), germanium (Ge), and antimony (Sb)-based catalysts that are generally used in esterification or transesterification reactions.

Specifically, titanium-based catalysts include tetraethyl titanate, acetyltripropyl titanate, tetrapropyl titanate, tetrabutyl titanate, polybutyl titanate, 2-ethylhexyl titanate, octylene glycol titanate, and lactate. Examples include titanate, triethanolamine titanate, acetyl acetonate titanate, ethyl acetoacetic ester titanate, isostearyl titanate, titanium dioxide, titanium dioxide/silicon dioxide copolymer, titanium dioxide/zirconium dioxide copolymer, etc. can do. In addition, germanium-based catalysts include germanium dioxide and copolymers using it, and tin-based catalysts include monobutyltin hydroxide oxide, tetrabutyldibutoxytin oxide, dibutyltin oxide, and dibutyltin dilaurate. etc. can be mentioned. These catalysts can be used alone or in combination.

The catalyst is preferably used in an amount of 10 to 500 ppm, 50 to 400 ppm, or 100 to 300 ppm based on the central metal of the catalyst, based on the total weight of the dicarboxylic acid component and diol component as raw materials. If the catalyst content is less than 10 ppm, the reaction rate may be slow due to insufficient catalyst amount. In addition, if the catalyst content exceeds 500 ppm, side reactions may occur or the catalyst may remain in the polyester resin being manufactured, which may lead to yellowing of the resin, so it is preferable to satisfy the above range.

The temperature for melting each of the above components is not particularly limited. For example, a molten mixture can be prepared by mixing the dicarboxylic acid component, diol component, and polymerization catalyst, raising the temperature to 150 to 180° C., and stirring.

Next, the molten mixture is polymerized at a pressure of 10 torr or less and a temperature of 160°C to 200°C to prepare a polyester resin. Specifically, after raising the temperature of the molten mixture to the desired reaction temperature, the reactor pressure can be lowered to 10 torr or less using a vacuum pump, and then melt polymerization can be performed.

Preferably, the temperature of the polymerization step may be 160°C or higher, or 170°C or higher, or 180°C or higher, and may be 200°C or lower, or 190°C or lower, and the pressure may be 10 torr or lower, 5 torr or lower, or 1 torr or lower. However, it may be 0.05 torr or more.

The performance time of the melt polymerization step may vary depending on the reaction temperature, pressure, and composition of the raw materials, but may be performed for 1 to 15 hours, or 5 to 12 hours, for example. In addition, during the melt polymerization, it is desirable to continuously discharge water or alcohol generated as a by-product out of the reactor to increase the reaction progress rate.

Meanwhile, instead of the above melt polymerization, 1) dicarboxylic acid component; and a diol component containing only 6,6'-dihydroxyethoxy-4,4,4',4',7,7'-hexamethyl-2,2'-spirobichromene, in the presence of a polymerization catalyst, at 700 °C. carrying out an esterification or transesterification reaction at a pressure of 800 torr and a temperature of 200 to 300 ° C, and 2) subjecting the reaction mixture to a condensation polymerization reaction at a pressure of 0.1 to 400 torr and a temperature of 240 to 300 ° C. Polyester resin can be manufactured through a manufacturing method comprising: According to the above production method, the terminal OH oligomer, which is a product of the esterification or transesterification reaction step, is condensed at a relatively high temperature to increase the degree of polymerization, thereby producing a polyester resin with a higher molecular weight than when melt polymerization.

The dicarboxylic acid component, diol component, and polymerization catalyst are as described above.

The esterification reaction may be performed at a temperature of 200 to 300 °C, preferably 220 to 280 °C, more preferably 235 to 265 °C, and normal pressure of 700 to 800 torr, or 750 to 800 torr. At this time, it is desirable to continuously discharge water or alcohol generated as a by-product during the esterification reaction out of the reactor to increase the reaction progress rate.

The esterification reaction time may generally be 100 minutes to 10 hours, preferably 2 hours to 500 minutes, and may vary depending on the reaction temperature, pressure, and molar ratio of the dicarboxylic acid component and diol component used.

A phosphorus-based stabilizer such as phosphoric acid, trimethyl phosphate, or triethyl phosphate may be further added to the esterification reaction. The amount of the phosphorus-based stabilizer added may be 30 to 500 ppm, or 50 to 300 ppm, based on the amount of elemental phosphorus, relative to the total amount of raw materials. If the amount of the stabilizer added is less than 30 ppm, the stabilizing effect is insufficient, and the color of the polyester resin may turn yellow. If it exceeds 500 ppm, there is a risk that a polymer with the desired high degree of polymerization may not be obtained.

After completion of the esterification reaction, a condensation polymerization reaction is performed. The condensation polymerization reaction is carried out at a temperature of 230 to 300°C, preferably 240 to 290°C, more preferably 250 to 280°C, and reduced pressure of 0.1 to 400 torr. The reduced pressure conditions of 0.1 to 400 torr are used to remove diols and oligomers that are by-products of the condensation polymerization reaction. The condensation polymerization reaction is carried out for the required time until the desired intrinsic viscosity is reached, for example, 1 to 10 hours, or 3 to 5 hours.

Hereinafter, the present invention will be described in more detail through the following examples. However, the following examples are only for illustrating the present invention and the scope of the present invention is not limited to these only.

[Example]

<Preparation example: Preparation of 6,6'-dihydroxyethoxy-4,4,4',4',7,7'-hexamethyl-2,2'-spirobichroman (DHS diol)>

In a 250 mL one-necked round bottom flask, 6,6'-dihydroxy-4,4,4',4',7,7'-hexamethyl-2,2'-spirobichloride was added with the composition shown in Table 1 below. 6,6'-Dihydroxy-4,4,4',4',7,7'-hexamethyl-2,2'-spirobichroman (DHS), ethylene carbonate (EC), and diazabicyclo Sen (1,8-Diazabicyclo[5.4.0]undec-7-ene, DBU) was added, stirred using a magnetic bar under a nitrogen atmosphere, and refluxed at 150°C to dissolve the reactant. After all the reactants were dissolved, the temperature was raised to 190°C and the hydroxyethylation reaction was performed for 12 h.

DHS EC DBU Molecular weight (g/mol) 368.47 88.06 152.24 Input (g) 15 7.17 1.24 mol (mol) 40.71 81.42 8.14

After completion of the reaction, the reactor was cooled to room temperature (25°C), and the crude product was dissolved in acetone. The prepared solution was precipitated with distilled water, and the obtained precipitate was washed with distilled water. Next, the powder-type product was obtained through vacuum filtration and dried in a vacuum oven at 30°C. The dried product was dissolved in acetone and purified by silica column chromatography (eluent: EA:Hexane = 1:1 v/v, rf: 0.3) to obtain DHS diol. Afterwards, the solvent was removed through a rotary evaporation process, and the DHS diol was dried in a vacuum oven. The chemical structure of the synthesized DHS diol was confirmed through ¹ H-NMR (see Figure 1).

<Manufacture of polyester resin using melt polymerization>

Example 1

Dimethyl terephthalate (DMT) as an acid component and the following diol component were added to the reactor in the composition shown in Table 2 below. At this time, the acid component and diol component were added at a molar ratio of 1:1.1. Next, monobutyltin hydroxide oxide (PMC, Fascat-9100 ^® ) as a catalyst was added in an amount of 200 ppm based on the central metal (Sn) based on the total weight of the acid component and diol component, and then incubated at room temperature. It was purged with nitrogen gas for 1 hour at (25°C). Afterwards, the temperature of the reactor was raised to 160°C, and the reactants were dissolved by stirring for 1 hour using a magnetic bar.

Next, the temperature of the reactor containing the molten reactants was raised to 190°C at a rate of 5°C/30 minutes. After the reactor temperature reached 190°C, melt polymerization was performed for 12 hours while maintaining the internal pressure of the reactor at 0.1 torr using a vacuum pump to prepare a polyester resin.

DMT EG CHDM BHT DHS diol Molecular weight (g/mol) 194.19 62.07 144.21 304.38 456.58 Input (g) 5.83 0.61 1.43 3.01 1.51 mol (mmol) 30 9.9 9.9 9.9 3.3

In Table 2, EG is ethylene glycol, CHDM is 1,4-cyclohexanedimethanol, and BHT is 3,9-bis(1,1-dimethyl-2-hydroxyethyl)-2,4,8,10-tetra. Oxaspiro[5,5]undecane, DHS diol is 6,6'-dihydroxyethoxy-4,4,4',4',7,7'-hexamethyl-2,2'-spirobicro It means only

In addition, the molar ratios between diol monomers in Table 2 were 30 mol% for EG, 30 mol% for CHDM, 30 mol% for BHT, and 10 mol% for DHS diol.

Comparative Examples 1 to 3

Among the diol monomers of Example 1, BHEPF (9,9-Bis[4-(2-hydroxyethoxy)phenyl]fluorine) and TMCBD (2,2,4,4-Tetramethyl-1,3-cyclobutanediol) were used instead of DHS diol, respectively. And CHDM (1,4-cyclohexanedimethanol) was used, and polyester resins were prepared with the compositions shown in Table 3 for Comparative Example 1, Table 4 for Comparative Example 2, and Table 5 for Comparative Example 3, according to the same method.

DMT EG CHDM BHT BHEPF Molecular weight (g/mol) 194.19 62.07 144.21 304.38 438.52 Input (g) 5.83 0.61 1.43 3.01 1.45 mol (mmol) 30 9.9 9.9 9.9 3.3

DMT EG CHDM BHT TMCBD Molecular weight (g/mol) 194.19 62.07 144.21 304.38 144.21 Input (g) 5.83 0.61 1.43 3.01 0.48 mol (mmol) 30 9.9 9.9 9.9 3.3

DMT EG CHDM BHT Molecular weight (g/mol) 194.19 62.07 144.21 304.38 Input (g) 5.83 0.61 1.90 3.01 mol (mmol) 30 9.9 13.2 9.9

Experiment example

(1) Measurement of diol composition in manufactured polyester resin

The polyester resin was dissolved in a CDCl ₃ solvent at a concentration of 25 mg/mL, and then a spectrum was obtained using a 400 MHz nuclear magnetic resonance spectrometer (NMR). From the above spectrum, the diol composition in the polyester resin was quantitatively analyzed.

(2) Glass transition temperature (Tg)

The glass transition temperature of the polyester resin of each Example and Comparative Example was measured using a differential scanning calorimeter (DSC).

Specifically, the sample (resin) was filled into an aluminum pan at 30°C, the temperature was raised to 310°C at 20°C/min, held at 310°C for 10 minutes, then the temperature was lowered to 30°C at -300°C/min and held for 5 minutes. Then, the glass transition temperature (Tg) was measured from the heat flow obtained when the temperature was raised to 310°C at 10°C/min.

(3) Intrinsic viscosity (IV)

1% in hexafluoro-2-propanol (HFP) at room temperature, that is, 25°C. After dissolving the polyester resin to the correct concentration, the intrinsic viscosity was measured using an Ubbelrod-type viscometer in a constant temperature bath at 35°C.

At this time, the temperature of the viscosity tube is maintained at 35°C, the time it takes for the solvent to pass through the inner section ab of the viscosity tube (efflux time) is t, and the time it takes for the solution to pass through is t. When t ₀ , specific viscosity is defined as Equation 1 below, and intrinsic viscosity was calculated using Equation 2 below.

[Equation 1]

[Equation 2]

In Equation 2, A is the Huggins constant, which is 0.247, and c is the concentration value, which is 1.2 g/dl.

Hereinafter, the measured values of Example 1 and Comparative Examples 1 to 3 are shown in Table 6 below.

Diol Diol used in polymerization
mole ratio (%) catalyst T _g (°C) IV (dl/g) EG CHDM BHT diol Example 1 DHS diol 30 30 30 10 Fascat9100(Sn)
200ppm 112.55 0.41 Comparative Example 1 BHEPF 30 30 30 10 Fascat9100 (Sn)200ppm 104.68 0.30 Comparative Example 2 TMCBD 30 30 30 10 Fascat9100 (Sn)200ppm 94.04 0.28 Comparative Example 3 CHDM 30 40 30 - Fascat9100 (Sn)200ppm 86.28 0.21

It was confirmed that the PETG of Example 1 produced using DHS Diol had a high Tg and IV compared to the PETG of Comparative Examples 1 to 3. This was found to be due to the rigid spiro ring structure and primary alcohol structure of DHS diol.

<Production of polyester resin including esterification step and condensation polymerization step>

Comparative Example 4

(1) Transesterification reaction (ES)

Dimethyl terephthalate (DMT) as an acid component and a diol component in the composition and content shown in Table 7 below were added to a reactor equipped with a trap and cooling pipe capable of collecting alcohol by-produced during the reaction. At this time, the acid component and diol component were added at a molar ratio of 1:1.1. Next, monobutyltin hydroxide oxide (PMC, Fascat-9100 ^® ) as a catalyst was added in an amount of 200 ppm based on the central metal (Sn) based on the total weight of the acid component and diol component, and then incubated at room temperature. It was purged with nitrogen gas for 1 hour at (25°C).

The temperature of the reactor was raised to 160°C, the reactants were dissolved by stirring for 1 hour using a magnetic bar, and then the temperature was raised to 240°C at a rate of 15°C/30 minutes. After the reactor temperature reaches 240 ℃, until the volume of methanol collected in the trap reaches the theoretical production amount under the pressure condition of 760 torr. The reaction proceeded. The reaction time was 4 hours . After completion of the reaction, the reaction product was cooled to room temperature.

(2) Polycondensation reaction (PC)

The reaction product of the transesterification reaction was placed in a reactor equipped with a mechanical stirrer and a vacuum pump, heated, and purged with nitrogen gas until it reached 250°C.

When the reactor temperature reached 250°C, the polycondensation reaction was performed by adjusting the temperature and pressure of the reactor as shown in Table 8 below while stirring at 50 rpm. Each step 1 to 5 was maintained for 30 minutes, and step 6 was maintained for 3 hours. Afterwards, the final product was cooled at room temperature to obtain a polyester resin.

DMT
(194.5 g/mol) EG
(62.07 g/mol) CHDM
(144.21 g/mol) BHT
(304.38 g/mol) DHS
(456.58 g/mol) Comparative Example 4 Input (g) 19.42 2.05 4.76 11.72 2.51 mol (mmol) 100.0 33.0 33.0 38.5 5.5 Example 2 Input (g) 19.42 2.05 4.76 10.04 5.02 mol (mmol) 100.0 33.0 33.0 33.0 11.0 Example 3 Input (g) 19.42 2.05 4.76 8.37 7.53 mol (mmol) 100.0 33.0 33.0 27.5 16.5 Example 4 Input (g) 19.42 2.05 4.76 6.70 10.04 mol (mmol) 100.0 33.0 33.0 22.0 22.0

step One 2 3 4 5 6 Temperature (℃) 250 265 273 276 278 280 pressure (torr) 350 200 70~80 20 8 ＞0.1

Hereinafter, the measured values of Comparative Example 4 and Examples 2 to 4 are shown in Table 9 below. Each measurement method is the same as described in the melt polymerization method above.

Comparative Example 4 Example 2 Example 3 Example 4 catalyst Fascat9100 (Sn): (200 ppm) Dior ingredient
(mol%) EG (mol%) 30.0 30.0 30.0 30.0 CHDM (mol%) 30.0 30.0 30.0 30.0 BHT (mol%) 35.0 30.0 25.0 20.0 DSH diol (mol%) 5.0 10.0 15.0 20.0 Diol composition in resin
(mol%) EG (mol%) - 12.2 21.6 21.1 CHDM (mol%) - 59.5 51.5 48.1 BHT (mol%) - 24.4 18.7 17.7 DSH diol (mol%) - 5.8 8.2 12.1 Tg (℃) - 116.18 113.16 112.00 IV (dl/g) - 0.59 0.46 0.46

In Comparative Example 4, the content of BHT was high, so solidification occurred due to the high crystallinity of BHT, and the esterification reaction product did not melt at high temperature, making polycondensation reaction impossible. According to the results of Examples 2 to 4, DHS diol was mixed with diol. It was confirmed that highly heat-resistant PETG with a glass transition temperature of 100°C or higher was synthesized by including it as a monomer.

Claims (13)

A polyester resin comprising a dicarboxylic acid repeating unit and a diol repeating unit,
The diol repeating unit includes a repeating unit derived from 6,6'-dihydroxyethoxy-4,4,4',4',7,7'-hexamethyl-2,2'-spirobicroman. Polyester resin.
According to paragraph 1,
Among 100 mol% of the diol repeating unit, derived from 6,6'-dihydroxyethoxy-4,4,4',4',7,7'-hexamethyl-2,2'-spirobichromene A polyester resin comprising 1.0 mol% to 15.0 mol% of repeating units.
According to paragraph 1,
The diol repeating unit includes a repeating unit derived from ethylene glycol, a repeating unit derived from 1,4-cyclohexanedimethanol, and 3,9-bis(1,1-dimethyl-2-hydroxyethyl)-2,4 A polyester resin containing one or more of the group consisting of repeating units derived from ,8,10-tetraoxaspiro[5,5]undecane.
According to paragraph 1,
A polyester resin comprising 5.0 to 55.0 mol% of a repeating unit derived from ethylene glycol, based on 100 mol% of the diol repeating unit.
According to paragraph 1,
A polyester resin comprising 10.0 to 65.0 mol% of a repeating unit derived from 1,4-cyclohexanedimethanol out of 100 mol% of the diol repeating units.
According to paragraph 1,
Among 100 mol% of the diol repeat units, repeats derived from 3,9-bis(1,1-dimethyl-2-hydroxyethyl)-2,4,8,10-tetraoxaspiro[5,5]undecane A polyester resin comprising 10.0 to 30.0 mol% of the unit.
According to paragraph 1,
A polyester resin comprising 50 mol% to 100 mol% of repeating units derived from terephthalic acid or a derivative thereof, out of 100 mol% of the dicarboxylic acid repeating units.
According to paragraph 1,
A polyester resin with a glass transition temperature of 95°C or higher.
Dicarboxylic acid component; A diol component containing only 6,6'-dihydroxyethoxy-4,4,4',4',7,7'-hexamethyl-2,2'-spirobichromene; and preparing a molten mixture of the polymerization catalyst, and
A method for producing a polyester resin comprising the step of polymerizing the molten mixture at a pressure of 10 torr or less and a temperature of 160 ℃ to 200 ℃.
Dicarboxylic acid component; and a diol component containing only 6,6'-dihydroxyethoxy-4,4,4',4',7,7'-hexamethyl-2,2'-spirobichromene, in the presence of a polymerization catalyst, at 700 °C. carrying out an esterification or transesterification reaction at a pressure of from 800 torr and a temperature of 200 to 300° C., and
A method for producing a polyester resin comprising subjecting the reaction mixture to a condensation polymerization reaction at a pressure of 0.1 to 400 torr and a temperature of 240 to 300 °C.
According to claim 9 or 10,
The diol component is 6,6'-dihydroxyethoxy-4,4,4',4',7,7'-hexamethyl-2,2'-spirobichroman in 100 mol% of the total diol component. A method for producing a polyester resin comprising 1 mol% to 50 mol%.
According to claim 9 or 10,
The diol component is ethylene glycol, 1,4-cyclohexanedimethanol, and 3,9-bis(1,1-dimethyl-2-hydroxyethyl)-2,4,8,10-tetraoxaspiro[5, 5] A method for producing a polyester resin comprising at least one selected from the group consisting of undecane.
According to claim 9 or 10,
A method for producing a polyester resin, wherein the molar ratio of the dicarboxylic acid component and the diol component is 1:1 to 1:3.