KR102675032B1 - Polyester resin and preparation method of the same - Google Patents

Abstract

The present invention relates to a polyester resin that exhibits excellent heat resistance due to a high residual rate of isosorbide, and has excellent mechanical properties such as tensile strength and Young's modulus, appearance characteristics, and transparency, and a method for producing the same.

Description

Polyester resin and its manufacturing method {POLYESTER RESIN AND PREPARATION METHOD OF THE SAME}

The present invention relates to polyester resins and methods for producing the same. More specifically, it relates to a polyester resin that exhibits excellent physical properties such as high heat resistance and impact resistance, and has excellent appearance properties, high transparency, and molding properties, and a method of manufacturing the same.

Polyester resins, which are generally manufactured from aromatic and/or aliphatic dicarboxylic acids and diols of appropriate structure, have excellent physical and chemical properties, as well as solubility and flexibility in general solvents, adhesion to a wide range of materials, and coating workability. It is widely used for a variety of purposes, including fibers, films, and adhesives.

In order to improve the physical properties of such polyester resins, polyester resins copolymerized with two or more diol or dicarboxylic acid components are widely used commercially. In particular, a method of using isosorbide (1,4:3,6-dianhydroglucitol), an eco-friendly diol compound derived from starch, as one of the monomers is known. Polyester resin containing isosorbide exhibits a high glass transition temperature and can be applied to a variety of items requiring heat resistance.

Meanwhile, in the production of polyester resin, the proportion of each raw material present in the main chain of the final polyester resin varies depending on the reactivity of each raw material in the esterification reaction or transesterification reaction, and the degree of vaporization of each raw material in the polycondensation reaction. You lose. The diol component represented by alkylene glycol is less reactive to secondary or tertiary alcohols than to primary alcohols, and is less reactive to tertiary alcohols than secondary alcohols. Therefore, when secondary or tertiary alcohols are included as raw materials, their main chain There are problems such as low residual rate, greatly increased reaction time, or significantly reduced reaction yield.

Isosorbide, a secondary alcohol, also has a low residual rate in the polyester main chain due to its low reactivity, and as a result, there is a problem in that the desired physical properties such as heat resistance and impact resistance are not sufficiently achieved. Therefore, there is a need for a polyester resin with a new composition and a method for producing the same that can overcome the problem of low residual ratio of isosorbide.

The present invention is intended to solve the above problem, and the residual rate of isosorbide is improved, showing physical properties such as excellent heat resistance, chemical resistance, and impact resistance, and a polyester resin having excellent appearance properties, high transparency, and molding properties, and manufacturing thereof. The purpose is to provide a method.

The present invention relates to residues of dicarboxylic acid components including terephthalic acid; and

Contains residues of diol components including isosorbide and 1,2-propanediol,

A polyester resin is provided wherein, out of 100 mol% of the residues of the diol component, the residues derived from isosorbide are at least 5 mol% and the residues derived from 1,2-propanediol are at least 10 mol%.

Preferably, the residues of the diol component may include 5 to 70 mol% of isosorbide-derived residues and 30 to 95 mol% of 1,2-propanediol-derived residues.

Preferably, the polyester resin may have a glass transition temperature (Tg) of 80°C or higher.

According to one embodiment of the present invention, the diol component is one or more diol compounds selected from the group consisting of aromatic diols with 8 to 40 carbon atoms and aliphatic diols with 2 to 20 carbon atoms, in addition to isosorbide and 1,2-propanediol. It may further include.

In one embodiment, the diol component may further include 1,4-cyclohexanedimethanol in addition to isosorbide and 1,2-propanediol, where the residue of the diol component is 5 to 45 mol%. of isosorbide-derived residues, 10 to 50 mol% of 1,2-propanediol-derived residues, and the remaining amount of 1,4-cyclohexanedimethanol-derived residues.

In addition to terephthalic acid, the dicarboxylic acid component may further include at least one acid component selected from the group consisting of an aromatic dicarboxylic acid component having 8 to 20 carbon atoms and an aliphatic dicarboxylic acid component having 4 to 20 carbon atoms.

In addition, the polyester resin of the present invention may further include the residue of a polyfunctional carboxylic acid component having 6 to 20 carbon atoms.

Additionally, the present invention provides a dicarboxylic acid component including terephthalic acid; and subjecting a diol component including isosorbide and 1,2-propanediol to an esterification or transesterification reaction at an applied pressure of 0.2 to 3.0 kg/cm2 and a temperature of 200 to 300°C; and

A method for producing a polyester resin comprising subjecting the reaction product to a polycondensation reaction under reduced pressure conditions of 400 to 0.1 mmHg and a temperature of 240 to 300°C,

A method for producing a polyester resin is provided, wherein the residual rate of isosorbide in the polyester is 40% or more.

In the method for producing a polyester resin according to an embodiment of the present invention, the diol component is 5 to 70 mol% of isosorbide and 30 to 95 mol% of 1,2-propanediol based on a total of 100 mol% of the diol component. It can be included.

Alternatively, the diol component may further include 1,4-cyclohexanedimethanol, wherein the diol component is 5 to 50 mol% of isosorbide and 1,2-propanediol based on a total of 100 mol% of the diol component. It may contain 10 to 75 mol% and the balance of 1,4-cyclohexanedimethanol.

In the method for producing a polyester resin according to an embodiment of the present invention, the molar ratio of the dicarboxylic acid component and the diol component may be 1:1 to 1:3.

In addition, according to one embodiment of the present invention, a polyfunctional carboxylic acid component having 6 to 20 carbon atoms may be further included in the esterification or transesterification reaction step.

The polyester resin of the present invention exhibits excellent heat resistance due to a high residual rate of isosorbide, and has excellent mechanical properties such as tensile strength and Young's modulus, appearance characteristics, and transparency.

Hereinafter, the present invention will be described in detail.

polyester resin

The present invention relates to residues of dicarboxylic acid components including terephthalic acid; and

Contains residues of diol components including isosorbide and 1,2-propanediol,

A polyester resin is provided in which, out of 100 mol% of the residues of the diol component, the isosorbide-derived residues are at least 5 mol% and the 1,2-propanediol-derived residues are at least 10 mol%.

In general, polyester resin mainly uses ethylene glycol as a diol component, and may further contain diols other than ethylene glycol to improve physical properties. Isosorbide (1,4:3,6-dianhydroglucitol) improves heat resistance when added to polyester resin and has the effect of improving physical properties such as chemical resistance and chemical resistance, so it is used as a diol along with ethylene glycol. It is used as an ingredient. However, since isosorbide is a secondary alcohol, its reactivity is very low compared to ethylene glycol, which is a primary alcohol, and it is difficult to obtain a high molecular weight resin due to the low degree of polymerization. The residual rate of isosorbide in the polyester resin is low, so it is not possible to achieve the desired level. There was a problem that sufficient heat resistance effect could not be obtained.

The present inventors studied various aspects to solve the above problem, and as a result, when 1,2-propanediol is used instead of the commonly used ethylene glycol, the reaction rate of isosorbide increases, and a high molecular weight resin can be obtained. It was confirmed that the residual rate of isosorbide in the main chain of the polyester resin being manufactured increased. Accordingly, the polyester resin of the present invention exhibits improved heat resistance and chemical resistance due to an increase in the residual rate of isosorbide. In addition, the polyester resin of the present invention exhibits mechanical properties such as tensile strength and Young's modulus at an equal or superior level compared to a polyester resin containing ethylene glycol and having a similar isosorbide content. Therefore, the polyester resin of the present invention can be preferably applied to food containers and packaging materials through injection and extrusion molding, packaging materials and materials for medical purposes, construction materials, automobile interior materials, and electronic product materials.

In this specification, the residual ratio refers to the content of monomer contained in the final polyester after the polymerization process compared to the input amount of each raw material (monomer). For example, the residual rate of isosorbide can be calculated using Equation 1 below.

[Equation 1]

Isosorbide residual rate (%) = (mol% of isosorbide-derived residues in 100 mol% of residues of diol component of polyester resin)/(number of moles of isosorbide added during polyester resin production) * 100

In this specification, 'residue' refers to a certain part or unit derived from a specific compound and included in the result of the chemical reaction when a specific compound participates in a chemical reaction. For example, each of the 'residue' of the dicarboxylic acid component or the 'residue' of the diol component is a portion derived from the dicarboxylic acid component or from the diol component in the polyester formed through an esterification reaction or condensation polymerization reaction. It means the part from which it originated.

The dicarboxylic acid component is a dicarboxylic acid such as terephthalic acid, its alkyl ester (lower alkyl ester with 1 to 4 carbon atoms such as monomethyl, monoethyl, dimethyl, diethyl or dibutyl ester), and/ Alternatively, it is used to include their acid anhydrides, and may react with the diol component to form dicarboxylic acid moiety such as terephthaloyl moiety.

As the dicarboxylic acid component used in the synthesis of the polyester includes terephthalic acid, the heat resistance, chemical resistance, or weather resistance of the produced polyester resin (e.g., prevention of molecular weight reduction or yellowing phenomenon due to UV), etc. The physical properties can be improved.

The dicarboxylic acid component may further include an aromatic dicarboxylic acid component, an aliphatic dicarboxylic acid component, or a mixture thereof as other dicarboxylic acid components. At this time, ‘other dicarboxylic acid components’ refers to components other than terephthalic acid among the dicarboxylic acid components.

The aromatic dicarboxylic acid component may be an aromatic dicarboxylic acid having 8 to 20 carbon atoms, preferably an aromatic dicarboxylic acid having 8 to 14 carbon atoms, or a mixture thereof. Examples of the aromatic dicarboxylic acids include naphthalenedicarboxylic acids such as phthalic acid, isophthalic acid, and 2,6-naphthalenedicarboxylic acid, diphenyl dicarboxylic acid, 4,4-stilbendicarboxylic acid, 2 , 5-furandicarboxylic acid, 2,5-thiophenedicarboxylic acid, etc., but specific examples of the aromatic dicarboxylic acid are not limited thereto.

The aliphatic dicarboxylic acid component may be an aliphatic dicarboxylic acid component having 4 to 20 carbon atoms, preferably 4 to 12 carbon atoms, or a mixture thereof. 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. , linear, branched or cyclic aliphatic dicarboxylic acids such as fumaric acid, adipic acid, glutaric acid and azelaic acid, but specific examples of the aliphatic dicarboxylic acids are not limited thereto. Since these aliphatic dicarboxylic acids can lower the glass transition temperature of the resin compared to aromatic dicarboxylic acids, they should be used in as small a quantity as possible, for example, so that the aliphatic dicarboxylic acid-derived residues among the dicarboxylic acid-derived residues are less than 30 mol%. It is desirable to use

The residue of the dicarboxylic acid component is 50 to 100 mol%, preferably 70 to 100 mol%, of terephthalic acid-derived residue; and 0 to 50 mol%, preferably 0 to 30 mol%, of residues derived from one or more dicarboxylic acids selected from the group consisting of aromatic dicarboxylic acids and aliphatic dicarboxylic acids. If the content of terephthalic acid-derived residues among the residues of the dicarboxylic acid component is too low, polyester The physical properties of the resin, such as heat resistance, chemical resistance, or weather resistance, may decrease.

Additionally, in the present invention, polyfunctional carboxylic acids can be additionally used in addition to dicarboxylic acids. The polyfunctional carboxylic acid refers to a carboxylic acid having three or more carboxyl groups. The polyfunctional carboxylic acid is an aromatic or aliphatic polyfunctional carboxylic acid component having 6 to 20 carbon atoms, preferably 6 to 9 carbon atoms, such as trimellitic acid, trimellitic anhydride, hemimellitic acid, and hemi anhydride. It includes, but is not limited to, melitic acid, trimesic acid, tricarbalic acid, etc.

The polyfunctional carboxylic acid has the advantage of improving processability during extrusion molding by increasing the melt viscosity of the resin through crosslinking. However, when used in large quantities, the melt viscosity of the resin is increased too much, which reduces processability and causes the resin to brittle, resulting in shock. Physical properties such as strength may decrease. Therefore, the polyfunctional carboxylic acid is used selectively when necessary, and the residue of the polyfunctional carboxylic acid component is preferably used in the range of 0 to 5 mol% based on 100 mol% of the residue of the dicarboxylic acid component.

The diol component included in the polyester resin of the present invention includes isosorbide and 1,2-propanediol, and may further include other diol compounds.

The isosorbide is included as one of the diol components to improve the physical properties such as heat resistance, chemical resistance, and chemical resistance of the resin. According to one embodiment of the present invention, the isosorbide-derived residue is preferably contained in an amount of 5 mol% or more, specifically in the range of 5 mol% to 70 mol%, in 100 mol% of the residues of the diol component, and 10 to 60 mol%. It is more preferable to include it in a % range. If the content of the isosorbide-derived residue is less than 5 mol%, the heat resistance properties of the polyester resin cannot be secured, and if it exceeds 70 mol%, the appearance characteristics of the polyester resin may deteriorate or yellowing may occur, so the above range It is desirable to satisfy.

The 1,2-propanediol is a diol component included in place of ethylene glycol, and is included to increase the fluidity and mechanical strength of the polyester resin and to increase the residual rate of isosorbide. Typically, ethylene glycol is mainly used as the diol component of polyester resin, but when 1,2-propanediol is used instead of ethylene glycol, the residual rate of isosorbide in the main chain is improved, and the polyester produced accordingly The heat resistance and durability of ester resin can be improved. In addition, the polyester resin containing 1,2-propanediol exhibits equivalent or improved heat resistance and mechanical strength at the same isosorbide content compared to the polyester resin containing ethylene glycol.

In order to ensure the above effect, the residue derived from 1,2-propanediol is 10 mol% or more, 20 mol% or more, or 30 mol% or more, and 95 mol% or less, or 90 mol%, out of 100 mol% of the residues of the diol component. It is preferable to include the following.

Specifically, the polyester resin of the present invention may include 5 to 70 mol% of isosorbide-derived residues and 30 to 95 mol% of 1,2-propanediol-derived residues in 100 mol% of residues of the diol component, Alternatively, it may include 10 to 60 mol% of isosorbide-derived residues and 40 to 90 mol% of 1,2-propanediol-derived residues.

Meanwhile, other diol compounds that can be included in addition to isosorbide and 1,2-propanediol in the present invention are not particularly limited as long as they are diol compounds commonly used in the production of polyester, for example, aliphatic diol, aromatic diol or It may be a mixture of these.

The aromatic diol may include an aromatic diol compound having 8 to 40 carbon atoms, preferably 8 to 33 carbon atoms. Examples of such aromatic diol compounds include polyoxyethylene-(2.0)-2,2-bis(4-hydroxyphenyl) propane, polyoxypropylene-(2.0)-2,2-bis(4-hydroxyphenyl) Propane, polyoxyethylene-(2.2)-polyoxyethylene-(2.0)-2,2-bis(4-hydroxyphenyl)Propane, polyoxyethylene-(2.3)-2,2-bis(4-hydroxyphenyl) Phenyl)propane, polyoxypropylene-(6)-2,2-bis(4-hydroxyphenyl)propane, polyoxypropylene-(2.3)-2,2-bis(4-hydroxyphenyl)propane, polyoxy Propylene-(2.4)-2,2-bis(4-hydroxyphenyl)propane, polyoxypropylene-(3.3)-2,2-bis(4-hydroxyphenyl)propane, polyoxyethylene-(3.0)- Bisphenol A derivatives to which ethylene oxide and/or propylene oxide are added, such as 2,2-bis(4-hydroxyphenyl)propane and polyoxyethylene-(6)-2,2-bis(4-hydroxyphenyl)propane. (polyoxyethylene-(n)-2,2-bis(4-hydroxyphenyl)propane, polyoxypropylene-(n)-2,2-bis(4-hydroxyphenyl)propane or polyoxypropylene-( n)-polyoxyethylene-(n)-2,2-bis(4-hydroxyphenyl)propane, etc., but specific examples of the aromatic diol compound are not limited thereto, where n is polyoxyethylene or poly. It means the number of oxypropylene units.

The aliphatic diol may include an aliphatic diol compound having 2 to 20 carbon atoms, preferably 2 to 12 carbon atoms. Examples of such aliphatic diol compounds 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-cyclohexane Linear, branched, or cyclic aliphatic diol components such as diol, 1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, and tetramethylcyclobutanediol may be included. Specific examples of aliphatic diol compounds are not limited thereto.

When the other diol compounds described above are further included as diol components, the residues derived from other diol compounds are preferably included in less than 70 mol%, less than 60 mol%, or less than 50 mol% in 100 mol% of the residues of the diol component. , the lower limit of the content is not limited, but may specifically include 0 mol% or more, 5 mol% or more, or 10 mol% or more. If the content of residues derived from other diol compounds among the residues of the diol component exceeds 70 mol%, the content of residues derived from isosorbide and 1,2-propanediol is relatively reduced, so heat resistance, chemical resistance, tensile strength, etc. The effect may not be sufficiently secured. In particular, diethylene glycol, triethylene glycol, 1,3-propanediol, 1,4-butanediol, 2,3-butanediol, 1,3-butanediol, pentanediol (1,5-pentanediol, etc.), hexanediol (1,5-pentanediol, etc.) , 6-hexanediol, etc.), neopentyl glycol (2,2-dimethyl-1,3-propanediol) can lower the glass transition temperature of the resin compared to other aliphatic diols, so use the diol component in as small a quantity as possible, for example. Of the 100 mol% of residues, it is preferable that the residues derived from the aliphatic diol are included in an amount of 30 mol% or less, or in the range of 0 to 10 mol%.

Meanwhile, according to one embodiment of the present invention, 1,4-cyclohexanedimethanol can be used as another diol compound to improve the impact resistance of polyester resin. In this way, the polyester resin further containing 1,4-cyclohexanedimethanol is specifically composed of 5 to 45 mol% of isosorbide-derived residues and 10 to 10 to 1,2-propanediol-derived residues out of 100 mol% of the residues of the diol component. It may contain 50 mol% and the balance of residues derived from 1,4-cyclohexanedimethanol, or 5 to 40 mol% of residues derived from isosorbide, 20 to 45 mol% of residues derived from 1,2-propanediol, and the balance. It may contain a residue derived from 1,4-cyclohexanedimethanol. When the residue of the diol component satisfies the above content range, it is preferable to ensure effects such as heat resistance, chemical resistance, and impact resistance.

The polyester resin of the present invention described above contains isosorbide as a diol component and exhibits excellent heat resistance and strength. Specifically, the polyester resin of the present invention may have a glass transition temperature (Tg) of 80 ℃ or higher, 90 ℃ or higher, 95 ℃ or higher, or 100 ℃ or higher, and a Young's modulus of 1350 MPa or higher, 1400 MPa or higher, Or it may be 1450 MPa or more. The method of measuring the glass transition temperature and Young's modulus may be specified in examples to be described later.

In addition, the polyester resin of the present invention has an intrinsic viscosity (IV) of 0.45 or more, 0.50 or more, or 0.52 or more, and shows a high molecular weight even though it contains isosorbide.

As it exhibits such high molecular weight, excellent heat resistance and strength characteristics, the polyester resin of the present invention is used in fields such as food containers and packaging materials, medical packaging and devices, automobiles and electronic materials, and construction materials that require heat resistance and rigidity. It can be used appropriately.

Manufacturing method of polyester resin

Meanwhile, the present invention provides a method for producing the polyester resin of the present invention described above. Specifically, the present invention provides a dicarboxylic acid component including terephthalic acid; and subjecting a diol component including isosorbide and 1,2-propanediol to an esterification or transesterification reaction at an applied pressure of 0.2 to 3.0 kg/cm2 and a temperature of 200 to 300°C; and

A method for producing a polyester resin is provided, comprising subjecting the reaction product to a polycondensation reaction under reduced pressure conditions of 400 to 0.1 mmHg and a temperature of 240 to 300°C.

According to the production method of the present invention, which includes 1,2-propanediol instead of the existing ethylene glycol as the diol component, the problems of lowering the degree of polymerization due to the low reactivity of isosorbide and lowering the residual rate of isosorbide in the polyester main chain are solved. Accordingly, a polyester resin with excellent heat resistance properties, mechanical properties, appearance properties, and moldability can be manufactured.

In the method for producing a polyester resin of the present invention, the dicarboxylic acid component is terephthalic acid, its alkyl ester, and/or their acid anhydride in an amount of 1 to 100 mol%, or 30%, based on a total of 100 mol% of the dicarboxylic acid component. to 100 mol%, and may include the remaining aromatic and/or aliphatic dicarboxylic acid components described above.

When only isosorbide and 1,2-propanediol are used as the diol components, isosorbide is 5 to 70 mol% and 1,2-propanediol is 30 to 95 mol% based on a total of 100 mol% of diol components. May be included.

On the other hand, when the diol component includes the other diol compounds described above in addition to isosorbide and 1,2-propanediol, the other diol compounds are less than 80 mol%, or less than 70 mol%, based on the total 100 mol% of the diol component. Alternatively, it is preferably used in less than 60 mol%.

More specifically, when 1,4-cyclohexanedimethanol is further included as another diol compound, the diol component is 5 to 50 mol% of isosorbide and 1,2-propanediol based on a total of 100 mol% of diol components. It is preferred that it contains 10 to 75 mol% and the balance of 1,4-cyclohexanedimethanol.

When the above input amounts of the dicarboxylic acid component and diol component are satisfied, a polyester resin having the residue of the dicarboxylic acid component and the residue of the diol component in an appropriate content range can be produced as described above.

In addition, the molar ratio of the dicarboxylic acid component and the diol component is preferably in the range of 1:1 to 1:3, or 1:1.05 to 1:2.05. 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 resin. If it exceeds 1:3, the speed of the polymerization reaction may decrease. It is desirable to satisfy the above range because it may become too slow and the productivity of the resin may decrease.

During the esterification reaction or transesterification reaction, in addition to the dicarboxylic acid component and the diol component, the above-described polyfunctional carboxylic acid having 6 to 20 carbon atoms may be further included. In this case, the processability of the polyester resin manufactured as described above can be improved, but if used in excessive amounts, processability may decrease and physical properties such as impact strength may decrease. Therefore, it is preferable that the polyfunctional dicarboxylic acid is used in the range of 0 to 5 mol% based on 100 mol% of the dicarboxylic acid component.

The esterification reaction or transesterification reaction (hereinafter referred to as esterification reaction) may be performed in a batch or continuous manner, and each raw material may be separately added to the reactor, but the dicarboxylic acid component and diol It may be desirable to add the ingredients in the form of a mixed slurry. At this time, additional water can be added to increase the solubility of diol components that are solid at room temperature, such as isosorbide, or the slurry can be prepared at 60°C or higher so that the solid content can be melted.

The esterification reaction is carried out at a temperature of 200 to 300°C, preferably 220 to 280°C, more preferably 235 to 265°C, and a pressure of 0.1 to 3.0 kg/cm2, preferably 0.2 to 3.0 kg/cm2. You can. 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 (average residence time) is usually 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. there is.

The esterification reaction may be carried out without a catalyst, but may be carried out by adding an appropriate reaction catalyst to shorten the reaction time. Catalysts that can be used at this time include titanium, aluminum, tin, germanium, and antimony-based catalysts, and these catalysts can also serve as catalysts for the subsequent polycondensation reaction.

Useful titanium-based catalysts include tetraethyl titanate, acetyltripropyl titanate, tetrapropyl titanate, tetrabutyl titanate, polybutyl titanate, 2-ethylhexyl titanate, octylene glycol titanate, and lactate 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. there is. In addition, germanium-based catalysts include germanium dioxide and copolymers using it, and tin-based catalysts include tetrabutyldibutoxytin oxide, dibutyltin oxide, and dibutyltin dilaurate. These catalysts can be used alone or in combination.

The catalyst is preferably used in an amount of 10 to 500 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, and if it exceeds 500 ppm, side reactions may occur or the catalyst may remain in the polyester resin being manufactured, so it is preferable to satisfy the above range. .

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 30ppm, the stabilizing effect is insufficient, and the color of the polyester resin may turn yellow. If it exceeds 500ppm, 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 polycondensation reaction is performed. The polycondensation 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 400 to 0.1 mmHg. The reduced pressure conditions of 400 to 0.1 mmHg are used to remove diols and oligomers that are by-products of the polycondensation reaction. The polycondensation reaction is carried out for the time required to reach the desired intrinsic viscosity, for example, for an average residence time of 1 to 10 hours.

When the polyester resin is produced according to the production method of the present invention, the residual rate of isosorbide is as high as 40% or more, or 45% or more, or 50% or more. Therefore, the polyester resin produced by the above method can exhibit excellent heat resistance, chemical resistance, and mechanical properties. The residual rate refers to the content of monomer included in the final polyester after the polymerization process compared to the input amount of raw materials (monomer).

In addition, according to the production method of the present invention, the reactivity of isosorbide is improved and the degree of polymerization can be increased, and the polyester resin produced accordingly has a high intrinsic viscosity (IV) of 0.45 or more, 0.50 or more, or 0.52 or more.

Hereinafter, the operation and effects of the invention will be described in more detail through specific examples of the invention. However, these examples are merely presented as examples of the invention, and the scope of the invention is not determined by them.

The evaluation methods of the polyester resin and tensile specimens of the following examples and comparative examples are as follows.

(1) Analysis of residues of diol components in resin

The residue content of the diol component in the resin was analyzed using nuclear magnetic resonance (NMR). Specifically, the peak integral value of dicarboxylic acid and polyfunctional carboxylic acid among the NMR peaks of the polyester resin was set to 100, and the relative value of the hydrogen peak of oxymethylene of each diol was derived to calculate the molar concentration. At this time, 600 MHz NMR (JEOL) was used as the instrument, and CDCl ₃ was used as the solvent.

(2) Intrinsic viscosity (IV)

After dissolving the polyester resin at a concentration of 0.12% in ortho-chlorophenol at 150°C, it was measured using an Ubbelrod-type viscometer in a constant temperature bath at 35°C.

(3) Number average molecular weight (Mn)

The number average molecular weight was measured using gel permeation chromatography (GPC, Tosoh) by the following method. Shodex LF804

A sample was prepared by dissolving 0.03 g of polyester resin in 3 mL of ortho-chlorophenol at 150°C for 15 minutes, and then adding 9 mL of chloroform at room temperature. Using 12 ml of ortho-chlorophenol:chloroform = 1:3 (v/v) solution as an eluent, the sample was injected and measured at a flow rate of 0.7 ml/min at a temperature of 40°C. The Mn value was derived using a calibration curve formed using a polystyrene standard.

(4) Heat resistance (Tg)

The polyester resin was annealed at 300°C for 5 minutes, cooled to room temperature, and then the Tg temperature during a second scan was measured at a temperature increase rate of 10°C/min.

(5) Color b

It was measured using Pacific Scientific's Colorgard System.

(6) Haze (%)

A film sample of the copolymerized polyester resin composition was aged for 24 hours in an atmosphere of 23˚C and 65%RH humidity, and then tested with a haze meter (Device name: NDH2000, Manufacturer: JIS) in accordance with JIS (Japanese Industrial Standards) K7136. The haze (%) was measured at three different positions of the film sample using Nippon Denshoku (Japan), and the average value of each measurement result was calculated as the result.

(7) Tensile strength and Young’s modulus

Using a baby injection machine, polyester resin was made into a tensile specimen (width 0.4 mm) under the conditions of a barrel temperature of 230˚C and a pressure of 600 kgf/㎠, a mold temperature of 30˚C, an injection time of 3 seconds, a holding pressure time of 5 seconds, and a cooling time of 10 seconds. cm, 3 cm in height, 0.2 cm in thickness, ISO 527-21 BB type), and then measured the tensile strength and Young's modulus using UTM.

Examples 1 to 7

Raw materials, namely dimethyl terephthalic acid (DMT), isosorbide (ISB), 1,4-cyclohexanedimethanol (CHDM), and 1,2-propanediol, were placed in a 5L reactor equipped with a stirrer and effluent condenser at the contents shown in Table 1 below. (1,2-PD) was added. Here, triethyl phosphate (TEP), a phosphorus stabilizer, and dibutyltin oxide (DBTO), a catalyst, were added in the amounts shown in Table 1 for the total weight of the raw materials based on the content of the central atom, respectively, and then pressured with nitrogen. After increasing the temperature to 2.0 kg/cm2, the reaction was performed while raising the temperature of the reactor to 220 to 250˚C.

At this time, the methanol generated at this time is discharged out of the system for a transesterification reaction. Once the generation and discharge of methanol is completed, the reactant is transferred to a polycondensation reactor equipped with a stirrer, cooling condenser, and vacuum system, and the polycondensation reaction is performed. When the viscosity reached the maximum, polymerization was terminated.

Comparative Examples 1 to 7

Polyester resin was prepared in the same manner as in Examples 1 to 7, except that ethylene glycol (EG) was used instead of 1,2-propanediol, and the raw materials were added in the amounts shown in Table 2 below.

ingredient Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 input
ratio Diacid DMT (mol) 100 100 100 100 100 100 100 Diol ISB (mol) 12 20 40 50 60 80 100 CHDM (mol) 45 45 45 50 45 45 45 1,2-PD (mol) 143 135 115 100 95 75 55 reaction catalyst DBTO (ppm) 300 300 300 250 300 250 250 stabilizator TEP (ppm) 200 200 200 200 200 200 200 Experiment
result dior
Furtherance ISB (mol%) 7 12 19 20 25 33 40 CHDM (mol%) 47 47 46 50 45 45 46 1,2-PD (mol%) 46 41 35 30 30 22 14 ISB Retention Rate (%) 58.3 60.0 47.5 40.0 41.7 41.3 40.0 IV(dl/g) 0.61 0.62 0.64 0.63 0.64 0.58 0.59 Number average molecular weight (Mn) 22,000 22,100 22,400 22,300 22,000 18,000 20,600 Heat resistance, Tg(℃) 94 99 103 104 110 114 121 color b 1.5 1.5 1.5 1.5 2 2.5 2.5 Haze (%) <1 <1 <1 <1 <1 <1 <1 Tensile strength (MPa) 44 45 46 47 48 49 50 Young's modulus (MPa) 1440 1420 1470 1400 1440 1590 1550

ingredient Comparative Example 1 Comparative example 2 Comparative Example 3 Comparative example 4 Comparative Example 5 Comparative Example 6 Comparative example 7 input
ratio Diacid DMT (mol) 100 100 100 100 100 100 100 Diol ISB (mol) 20 40 50 60 80 100 120 CHDM (mol) 45 45 50 45 45 45 45 EG (mol) 135 115 100 95 75 75 55 reaction catalyst DBTO (ppm) 300 300 250 300 300 300 300 stabilizator TEP (ppm) 200 200 200 200 200 200 200 Experiment
result dior
Furtherance ISB (mol%) 7 13 12 21 29 33 41 CHDM (mol%) 45 45 47 45 45 46 45 EG (mol%) 48 42 41 34 26 21 14 ISB Retention Rate (%) 35.0 32.5 24.0 35.0 36.3 33.2 34.4 IV(dl/g) 0.66 0.64 0.58 0.60 0.58 0.45 0.32 Number average molecular weight (Mn) 23,100 22,300 19,400 21,800 20,600 11,900 9,400 Heat resistance (℃) 88 96 95 104 110 110 108 color b 1.5 1.5 One 2 2 3 3 Haze (%) <1 <1 <1 <1 <1 <1 <1 Tensile strength (MPa) 43 43 43 45 45 Not measurable Not measurable Young's modulus (MPa) 1360 1370 1430 1430 1480 Not measurable Not measurable

Example 8 to 13

Excluding 1,4-cyclohexanedimethanol as the diol component, raw materials such as dimethyl terephthalic acid, isosorbide, and 1,2-propanediol were added in the amounts shown in Table 3 below. Here, triethyl phosphate (TEP), a phosphorus stabilizer, and tetrabutyldibutoxytin oxide (TBT), a catalyst, are added in the amounts shown in Table 1 relative to the total weight of the raw materials based on the content of the central atom, respectively, and then converted to nitrogen. After increasing the pressure to 2.0 kg/cm2, the reaction was performed while raising the temperature of the reactor to 220 to 250˚C.

At this time, the methanol generated is discharged out of the system to undergo a transesterification reaction. Once the generation and discharge of methanol is completed, the reactant is transferred to a polycondensation reactor equipped with a stirrer, cooling condenser, and vacuum system to proceed with the polycondensation reaction, and the intrinsic viscosity is reduced. When the maximum value was reached, polymerization was terminated.

Comparative Examples 8 to 13

Polyester resin was prepared in the same manner as in Examples 8 to 13, except that ethylene glycol (EG) was used instead of 1,2-propanediol and the raw materials were added in the amounts shown in Table 4 below.

ingredient Example 8 Example 9 Example 10 Example 11 Example 12 Example 13 input
ratio Diacid DMT (mol) 100 100 100 100 100 100 Diol ISB (mol) 20 40 60 80 100 120 1,2-PD (mol) 180 160 140 120 100 80 reaction catalyst TBT (ppm) 250 250 250 200 200 200 stabilizator TEP (ppm) 100 100 100 100 100 100 Experiment
result dior
Furtherance ISB (mol%) 15 27 41 48 59 66 1,2-PD (mol%) 85 73 59 52 41 34 ISB Retention Rate (%) 75.0 67.5 68.3 60.0 59.0 55.0 IV(dl/g) 0.52 0.57 0.58 0.60 0.55 0.58 Number average molecular weight (Mn) 17,800 19,700 20,600 21,800 20,100 19,900 Heat resistance (℃) 93 106 126 132 141 150 color b 5 4.5 4.5 5 4.5 4.5 Haze (%) <2 <2 <2 <2 <2 <2 Tensile strength (MPa) 48 48 50 57 58 57 Young's modulus (MPa) 1480 1520 1550 1690 1660 1700

ingredient Comparative example 8 Comparative Example 9 Comparative Example 10 Comparative Example 11 Comparative Example 12 Comparative Example 13 input
ratio Diacid DMT (mol) 100 100 100 100 100 100 Diol ISB (mol) 20 40 60 80 100 120 EG (mol) 180 160 140 120 100 80 reaction catalyst TBT (ppm) 250 250 250 200 250 250 stabilizator TEP (ppm) 100 100 100 100 100 100 Experiment
result dior
Furtherance ISB (mol%) 7 16 25 34 42 57 EG (mol%) 93 84 75 66 58 43 ISB Retention Rate (%) 35.0 40.0 41.7 42.5 42.0 47.5 IV(dl/g) 0.57 0.60 0.58 0.54 0.54 0.31 Number average molecular weight (Mn) 17,800 19,700 20,600 21,800 20,100 10,500 Heat resistance (℃) 86 93 101 112 121 115 color b 4 5 4.5 4.5 5 5 Haze (%) <2 <2 <2 <2 <2 <2 Tensile strength (MPa) 45 47 48 47 48 Not measurable Young's modulus (MPa) 1480 1520 1580 1550 1500 Not measurable

Comparing Tables 1 and 2, Tables 3 and 4 above, respectively, when producing a polyethylene resin containing 1,2-propanediol instead of ethylene glycol, the residual rate of isosorbide is significantly improved, and the resin has excellent heat resistance. You can see that it represents . In addition, polyethylene resin containing 1,2-propanediol exhibits similar appearance characteristics and transparency compared to polyethylene resin containing conventional ethylene glycol, while exhibiting tensile strength and Young's modulus at the same or improved level, and thus mechanical strength properties as well. It was confirmed to be excellent.

Claims (13)

residues of dicarboxylic acid moieties including terephthalic acid; and
Contains the residue of a diol component comprising isosorbide and 1,2-propanediol and not including ethylene glycol,
A polyester resin in which, out of 100 mol% of the residues of the diol component, the residues derived from isosorbide are 5 mol% or more, and the residues derived from 1,2-propanediol are 10 mol% or more. According to paragraph 1,
A polyester resin wherein the residues of the diol component include 5 to 70 mol% of isosorbide-derived residues and 30 to 95 mol% of 1,2-propanediol-derived residues. According to paragraph 1,
A polyester resin having a glass transition temperature (Tg) of 80° C. or higher. According to paragraph 1,
In addition to isosorbide and 1,2-propanediol, the diol component further includes at least one diol compound selected from the group consisting of aromatic diols having 8 to 40 carbon atoms and aliphatic diols having 2 to 20 carbon atoms. According to paragraph 1,
The diol component further includes 1,4-cyclohexanedimethanol in addition to isosorbide and 1,2-propanediol,
The residues of the diol component include 5 to 45 mol% of isosorbide-derived residues, 10 to 50 mol% of 1,2-propanediol-derived residues, and the balance of 1,4-cyclohexanedimethanol-derived residues. Polyester resin. According to paragraph 1,
The dicarboxylic acid component, in addition to terephthalic acid, further includes at least one acid component selected from the group consisting of an aromatic dicarboxylic acid component having 8 to 20 carbon atoms and an aliphatic dicarboxylic acid component having 4 to 20 carbon atoms. profit. According to paragraph 1,
A polyester resin further comprising the residue of a polyfunctional carboxylic acid component having 6 to 20 carbon atoms. Dicarboxylic acid components including terephthalic acid; And the diol component containing isosorbide and 1,2-propanediol and not containing ethylene glycol is subjected to an esterification or transesterification reaction at an applied pressure of 0.2 to 3.0 kg/cm2 and a temperature of 200 to 300 ° C. step, and
A method for producing a polyester resin comprising subjecting the product obtained after the esterification reaction or transesterification reaction to polycondensation under reduced pressure conditions of 400 to 0.1 mmHg and a temperature of 240 to 300°C,
A method for producing a polyester resin, wherein the residual rate of isosorbide in the polyester is 40% or more. According to clause 8,
The diol component includes 5 to 70 mol% of isosorbide and 30 to 95 mol% of 1,2-propanediol based on a total of 100 mol% of the diol component. According to clause 8,
A method for producing a polyester resin, wherein the diol component further includes 1,4-cyclohexanedimethanol. According to clause 10,
The diol component is a polyester containing 5 to 50 mol% of isosorbide, 10 to 75 mol% of 1,2-propanediol, and the remaining amount of 1,4-cyclohexanedimethanol based on a total of 100 mol% of the diol component. Resin manufacturing method. According to clause 8,
A method for producing a polyester resin, wherein the molar ratio of the dicarboxylic acid component to the diol component is 1:1 to 1:3. According to clause 8,
A method for producing a polyester resin, further comprising a polyfunctional carboxylic acid component having 6 to 20 carbon atoms in the esterification or transesterification reaction step.