KR20190063669A - Thermoplastic polyester resin composition having good color and heat resistance - Google Patents

Abstract

The present invention relates to a composition for manufacturing a polyester resin having excellent color and heat resistance. More particularly, the present invention relates to the composition for manufacturing the polyester resin having high transparency, excellent color, and a high viscosity index suitable for use in molding a container. According to the present invention, when conducting polyester polymerization, by comprising a polyfunctional compound as a diol compound, it is possible to provide polyester having remarkably improved an intrinsic viscosity, color characteristics, and heat resistance.

Description

TECHNICAL FIELD [0001] The present invention relates to a composition for producing a polyester resin excellent in color and heat resistance,

The present invention relates to a composition for producing a polyester resin having excellent color and heat resistance, and more particularly, to a composition for producing a polyester resin having a high transparency and color and a high IV suitable for use in molding a container will be.

(Sb2O3) and 5.0 to 50 ppm (based on the amount of P element) of a diol compound relative to a dicarboxylic acid compound as a raw material of a polyester resin. , 10 to 40 ppm of cobalt compound (based on the amount of Co element), and the like have been proposed.

However, conventional polyester resins have a disadvantage of insufficient heat resistance, and attempts have been made to solve this problem by using isosorbide as a monomer for improving heat resistance. However, when yellowish beads are included in the production of polyester resin, there is a problem that the yellowing of the resin color is deteriorated and the speed of the solid-state polymerization is lowered at the same time as the chromaticity coordinates defect due to pyrolysis during the production of the molded product by using the polyester resin.

Specifically, U.S. Patent Application Publication No. 10 / 293,605 discloses a method for improving the heat resistance of polyester. Hereinafter, a method for introducing a thermosetting resin into a thermosetting resin is disclosed. According to this method, But there is a disadvantage that yellowing occurs due to oxygen present in the isosorbide molecule.

Disclosure of Invention Technical Problem [8] Accordingly, the present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to solve the problems such as the reaction rate in solid phase polymerization, intrinsic viscosity suitable for container molding, heat resistance, yellowing phenomenon by including a polyfunctional compound as a diol compound in polyester polymerization To provide a composition for producing a polyester resin.

In order to solve the above problems, the present invention provides a composition in which the molar ratio of the diol compound to the dicarboxylic acid or the ester compound thereof is 1.05 to 1.4, and the diol compound is a composition comprising 1 to 15 mol% Wherein the composition is a polyester resin comprising 10 to 40 ppm of phosphorus compounds (based on the amount of P element), 1 to 40 ppm of a color improver, and 5 to 30 ppm of a polyester polycondensation catalyst (based on the amount of a metal element) Lt; / RTI >

Wherein the polyester polycondensation catalyst comprises a titanium composite metal oxide represented by Chemical Formula 1 or Chemical Formula 2 below.

[Chemical Formula 1]

(2)

(Wherein n is an integer of 2 to 20)

And the titanium composite metal oxide catalyst is mixed with ethylene glycol and then introduced.

The dicarboxylic acid compound may be at least one selected from the group consisting of phthalic acid, terephthalic acid, isophthalic acid, dibromoisophthalic acid, sodium sulfoisophthalic acid, phenylenedioxydicarboxylic acid, 4,4'-diphenyldicarboxylic acid, '-Diphenyltetradicarboxylic acid, 4,4'-diphenyl ketone dicarboxylic acid, 4,4'-diphenoxyethane dicarboxylic acid, 4,4'-diphenylsulfone dicarboxylic acid And 2,6-naphthalene dicarboxylic acid. The present invention also provides a composition for the production of a polyester resin.

And the dicarboxylic acid compound comprises 90 to 100 mol% of the terephthalic acid and 0 to 10 mol% of the isophthalic acid.

The diol compound is at least one selected from the group consisting of monoethylene glycol, diethylene glycol, 1,3-propylene diol, 1,4-butylene diol, 1,4-cyclohexanedimethanol and neopentyl glycol By weight based on the total weight of the composition.

The phosphorus compound may also be phosphoric acid, trimethyl phosphate, triethyl phosphate, tri-n-butyl phosphate, trioctyl phosphate, triphenyl phosphate, tricresyl phosphate, methyl acid phosphate, ethyl acid phosphate, isopropyl phosphate, Wherein the color improving agent is at least one selected from the group consisting of diethyl phosphate, monobutyl phosphate, dibutyl acid phosphate, dioctyl phosphate, triethyleneglycolic acid phosphate and triethylphosphonoacetate, Or a mixed dye of a violet dye and a red dye, and to provide a composition for producing a polyester resin.

The present invention also provides a composition for producing a polyester resin, wherein the polyfunctional compound is a polyfunctional alcoholic compound.

Also provided is a polyester resin composition having a glass transition temperature (Tg) of 80 ° C or higher, a color coordinate L value of 77.0 or more and a color coordinate b value of 2.0 or less, of the polyester resin produced using the composition.

According to the present invention, when a polyfunctional compound is contained as a diol compound in the polyester polymerization, the glass transition temperature is elevated, and thus a polyester having an intrinsic viscosity, color property and heat resistance can be remarkably improved.

Hereinafter, preferred embodiments of the present invention will be described in detail. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. Throughout the specification, when an element is referred to as "including " an element, it means that it can include other elements, not excluding other elements, unless specifically stated otherwise.

The present inventors have observed that there is a problem that isosorbide used for improving the heat resistance of a conventional composition for producing a polyester resin causes color defects due to thermal decomposition during the production of a molded article, As a result of intensive researches for solving the problems, it has been confirmed that when a polyfunctional compound is included in a polyester polymerization, it can have improved intrinsic viscosity, heat resistance and color as compared with conventional polyester resins, and the present invention has been completed .

Accordingly, the present invention has been made in view of the above problems, and an object of the present invention is to solve the problems of yellowing of resin color occurring in the production of polyester resin, defect of chromaticity coordinate due to pyrolysis during molding, Content.

Specifically, the present invention relates to a composition comprising a diol compound having a molar ratio of 1.05 to 1.4 with respect to a dicarboxylic acid or an ester compound thereof, wherein the diol compound is a polyfunctional compound having at least 3 hydroxyl groups of 1 to 15 mol% , Said composition comprising a polyester resin composition comprising 10 to 40 ppm of phosphorus compound (based on the amount of P element), 1 to 40 ppm of color improving agent, and 5 to 30 ppm of polyester polycondensation catalyst (based on the amount of metal element) do.

In the present invention, the L value of the color coordinate of the polyester resin is a value indicating brightness of the resin, and a brighter and more transparent color is obtained. Therefore, the color coordinate L value is preferably 77 or more, more preferably 80 or more, still more preferably 81.5 or more, and most preferably 82 or more.

The color coordinate b value is a value indicating the degree of yellow and blue of the color, and the lower the value is, the higher the color is. Therefore, the color coordinate b value is preferably 2.0 or less, more preferably 1.0 or less, still more preferably 0.5 or less, and most preferably 0.0 or less.

In the present invention, it is preferable that the polyester resin has an intrinsic viscosity (I.V) of 0.74 to 1.00 dl / g, but it can be adjusted depending on the use place and the type of the final product. And more preferably 0.760-0.850 dl / g.

The composition for preparing a polyester resin according to the present invention is composed of a dicarboxylic acid or an ester compound thereof and a diol compound as a main raw material. The dicarboxylic acid compound includes aromatic molecules as a main component of the diacid compound. In the present invention, the dicarboxylic acid compound is not limited to phthalic acid, terephthalic acid, isophthalic acid, dibromoisophthalic acid, sodium sulfoisophthalate, phenyl Diphenyl dicarboxylic acid, 4,4'-diphenyl ketone dicarboxylic acid, 4,4'-diphenyldicarboxylic acid, 4,4'-diphenyldicarboxylic acid, Diphenoxyethane dicarboxylic acid, 4,4'-diphenylsulfone dicarboxylic acid, 2,6-naphthalene dicarboxylic acid and the like, and preferably terephthalic acid or its ester compound and other dicar Mixtures of the carboxylic acid compounds may be used. When the mixture is used, the terephthalic acid content is preferably at least 90 mol%, more preferably at least 95 mol%, and most preferably at least 99 mol% of the total dicarboxylic acid compound. The most preferred composition of the mixture is a mixture of terephthalic acid and isophthalic acid.

The diol compound may be, but is not limited to, monoethylene glycol, diethylene glycol, 1,3-propylene diol, 1,4-butylene diol, 1,4-cyclohexanedimethanol, neopentyl glycol, May be monoethylene glycol alone, monoethylene glycol or diethylene glycol and / or mixtures of other diol compounds. When the mixture is used, the content of the monoethylene glycol or diethylene glycol is preferably at least 95 mol%, more preferably at least 98 mol%, of the total diol compound. The most preferred composition of the mixture is a mixture of monoethylene glycols or diethylene glycol and neopentyl glycol.

In the present invention, the content ratio of the diol compound to the dicarboxylic acid or its ester compound is 1.05 to 1.4 on a molar basis. At this time, in order to improve the color and intrinsic viscosity of the composition for preparing polyester resin according to the present invention and to prevent deterioration of properties of the prepolymerized polymer, the content ratio is preferably 1.1 to 1.3.

The phosphorus compound is used as a heat stabilizer to prevent changes in the physical and chemical properties of the resin due to heat, and it is contained in an amount of 10 to 40 ppm (based on the amount of P element) based on the total weight of the polyester resin composition to be finally produced. Preferably 10 to 35 ppm. If the content of the phosphorus compound is less than 10 ppm, the thermal stability may be deteriorated and yellowing may occur. If it exceeds 35 ppm, the production cost may be deteriorated. A phenomenon may occur, which may adversely affect the reaction.

Such phosphorus compounds include, but are not limited to, trimethyl phosphate, triethyl phosphate, tri-n-butyl phosphate, trioctyl phosphate, triphenyl phosphate, tricresyl phosphate, methyl acid phosphate, ethyl acid phosphate, isopropyl phosphate, Diethylphosphate, monobutylphosphate, dibutylphosphate, dioctylphosphate, triethylene glycol acid phosphate and the like can be used, and preferably phosphoric acid, triethylphosphate, and ethylphosphate can be used, more preferably phosphoric acid And triethylphosphonoacetate can be used.

The cobalt compound serving as a coloring agent in the present invention is restricted in its use due to human toxicity such as pulmonary vascularization and classification of human carcinogens, and a color improving agent which is harmless to the human body can be used as a cobalt compound in general. The color improving agent is used for improving the color of a container or the like molded using a polyester resin, and 1.0 to 40 ppm is included based on the total weight of the polyester resin composition to be finally produced. And preferably 5 to 40 ppm. If the color improving agent content is less than 5 ppm, the color improving effect may be insufficient. If the color improving agent content is more than 40 ppm, the color may be somewhat darkened.

The color improving agent is not limited, but it is preferable to use a mixture of a blue dye and a red dye, or a mixture of a violet dye and a red dye.

The kind of the catalyst used in the production of the composition for preparing a polyester resin according to the present invention is not specifically limited and an alkali metal, an alkaline earth metal, antimony, titanium, manganese, cobalt, cerium, germanium or a mixture thereof can be used, A titanium-based composite metal oxide may be used.

Specifically, in the present invention, in order to improve the yellowing phenomenon of the polymer and the deterioration of the productivity due to the increase in the solid state viscosity of the polymer which is intensified in the use of the conventional titanium catalyst compound in the composition for producing polyester resin, the decrease in catalytic activity due to phosphorus (P) A titanium-based composite metal oxide can be used which can be used in excess of the conventional phosphorus so that pyrolysis is reduced, yellowing phenomenon is improved, and high viscosity can be maintained.

The catalyst composition of the present invention includes a composite metal oxide including titanium (Ti), aluminum (Al), and magnesium (Mg). The titanium-based composite metal catalyst composition of the present invention may be represented by the following general formula (1) or (2).

[Chemical Formula 1]

(2)

(Wherein n is an integer of 2 to 20)

The titanium composite metal oxide catalyst is stable to moisture and easy to store, and unlike the antimony catalyst, the toxicity of the metal itself is relatively low, and thus it is unlikely to cause human and environmental problems.

The composite metal oxide catalyst is preferably a solution formed by dissolving in ethylene glycol.

In the present invention, the titanium composite metal oxide catalyst is contained in an amount of 5 to 30 ppm (based on the amount of Ti element) based on the total weight of the polyester resin composition to be finally produced. Preferably 8 to 15 ppm, and more preferably 10 to 15 ppm. The titanium composite metal oxide catalyst content is a result obtained by grasping the best range of improvement in hue and intrinsic viscosity of the polyester resin prepared from the composition for preparing polyester resin according to the present invention. Specifically, when the titanium content is less than 5 ppm, the reaction may not be performed or may be slowed. If the titanium content exceeds 30 ppm, the color of the polymer may not be good due to high activity of the titanium catalyst.

In the present invention, the diol compound may contain a polyfunctional compound in an amount of 1 to 15 mol% in order to impart heat resistance in a composition for producing a polyester resin. The polyfunctional compound improves the thermal properties of the polyester by allowing the polyester to have a higher glass transition temperature. Further, the effect of shortening the liquid phase polymerization time through the branched structure of the polyfunctional compound is shown, which can contribute to the increase of the viscosity and the improvement of the melt strength in the solid phase polymerization.

The polyfunctional compound may be a bifunctional to hexafunctional compound, preferably a trifunctional to pentafunctional compound.

The polyfunctional compound may be an alcohol compound, and non-limiting examples thereof include 4-amino-4- (3-hydroxypropyl) -1,7-heptanediol (4-amino- hydroxypropyl) -1,7-heptanediol, 1,5-dihydroxy anthraquinone, 1,2-benzene dimethanol, 1,2,4- Benzene triol, 2-benzyloxy-1,3-propanediol, 2,2'-biphenyl dimethanol (2,2 ' -biphenyldimethanol, 2,2'-bipyridine-3,3'-diol, 2,2-bisbromomethyl-1,3-propanediol N-bis (2-hydroxyethyl) -1,3-propanediol, 1- [N, N-bis (2-hydroxyethyl) ) amino] -2-propanol, N, N-bis (2-hydroxyethyl) isonicotinamide, bis (2- (2-hydroxyethyl) terephthalate, 2,2-bis (hydroxymethyl) butyric 4-bromo-3,5-dihydroxybenzoic acid, 2- (bromomethyl) -2- (hydroxymethyl) -1,3-propane Bromomethyl-1,3-propanediol, 3-bromo-1,2-propanediol, tert-butyl hydroquinone, tert- -Butylhydroquinone, chlorohydroquinone, 5-chloro-2,3-pyridinediol, 1,2-cyclohexanediol, cis, Cis-1,3,5-cyclohexanetriol dihydrate, 3-cyclohexene-1,1-dimethanol (3-cyclohexane- ), Cis-1,2-cyclopentanediol, 1,2-decanediol, 2,3-dibromo-1,4-butanediol (2 , 3-dibromo-1,4-butanediol, trans-2,3-dibromo-2-butene-1,4-diol, 2,5-dibromohydroquinone, 2,3-dichloro-5,8-dihydroxy-1,4-naphthoquinone (2,3-dichlo ro-5,8-dihydroxy-1,4-naphthoquinone, diethyl bis (hydroxymethyl) malonate, diethyl 2,5-dihydroxy terephthalate (diethyl 2,5 dihydroxyterephthalate, 3,5-dihydroxyacetophenone, 4,4'-dihydroxybenzophenone, 2,5-dihydroxy-1, 2,5-dihydroxy-1,4-benzoquinone, 2,2-dihydroxy-5-methoxy-1,3-indanedione hydrate, 1,3-indanedione hydrate, 2,6-dihydroxy-4-methyl-3-pyridinecarbonitrile, tris (2-hydroxyethyl) iso Tris (2-hydroxyethyl) isocyanurate, 1,1,1-tris (4-hydroxyphenyl) ethane, (2,4,6-trihydroxybenzoic acid), 3,3,3 ', 3'-tetramethyl-1,1'-spirobiindane-5,5', 6,6'-tetraol 3,3,3 ', 3'-tetramethyl-1,1'-spirobiindane-5,5', 6,6'-tetraol) or (N, N, N ', N'-tetrakis (2-hydroxypropyl) ethylenediamine), and the like, 1,1,1-tris (4-hydroxyphenyl) ethane, THPE).

In the present invention, the polyfunctional compound may be contained in an amount of 1 to 15 mol%, preferably 1 to 10 mol%, more preferably 3 to 10 mol%, and most preferably 5 to 10 mol% Mol%. ≪ / RTI > When the content of the polyfunctional compound in the diol compound is less than 1 mol%, the improvement of the glass transition temperature of the polyester resin does not occur and the improvement of heat resistance may be insufficient, and the polymerization time becomes longer, intrinsic viscosity decreases, Can be a problem. When the content of the polyfunctional compound is more than 15 mol%, the gel may be formed under the influence of the polyfunctional alcohol, and polymerization of the resin may be difficult.

The composition for preparing a polyester resin according to the present invention may further contain an antioxidant, an ultraviolet screening agent, an antistatic agent, a flame retardant, a surfactant and the like, if necessary.

 The method for producing a polyester resin using the composition for preparing a polyester resin according to the present invention may be based on a method commonly used in the technical field to which the present invention belongs, and the method is not particularly limited. For example, it can be produced by the following method using a batch type reactor. Of course, it may be carried out continuously and is not particularly limited.

That is, the method for producing a polyester resin of the present invention comprises the steps of (A) mixing a dicarboxylic acid compound and a diol compound in the above-mentioned amounts to prepare a slurry, (B) adding a polyesters polycondensation catalyst to the slurry (C) the compound (B) is added in any steps before the slurry step and the esterification step so as to be polymerizable, (D) the phosphorus compound and the color improving agent are added after the esterification reaction, (E) condensation polymerization of the resultant product; (F) discharging the condensation polymerization product to produce a molten chip; And (G) crystallizing the molten chip to perform solid phase polymerization.

More preferably, the present invention relates to a process for producing a slurry by reacting a dicarboxylic acid or its ester compound and a diol as a main component in a reactor equipped with a titanium composite metal oxide catalyst to prepare a slurry and transferring the slurry to an esterification reactor, 80% or more, preferably 90% or more, and then a thermal stabilizer and a color improver are added to the condensation polymerization reactor to carry out condensation polymerization. Thereafter, the reaction is carried out at a polymerization degree of 100 or more in the condensation polymerization reaction, followed by cutting in water to produce a molten chip having an intrinsic viscosity (IV) of 0.5-0.7 (dl / g). The cut molten chips are transferred to a solid phase polymerization (SSP) machine to produce a polyester resin for forming a container having an intrinsic viscosity of 0.7-1.0 (dl / g).

In the present invention, the esterification reaction can be carried out at a temperature of 245 to 265 ° C and a pressure of 0.5 to 3.0 kg / cm 2. In addition, the system constitutes such that the water during the esterification reaction can be removed immediately.

The polycondensation reaction can be carried out at a temperature of 270-290 ° C and a pressure of 0.1-2.0 torr. The ethylene glycol and by-products resulting from the condensation polymerization are configured to be readily removable.

The catalyst and the phosphorus compound as the heat stabilizer and the color improving agent may be added at any stage of the slurry preparation step, the esterification step, and the polycondensation step.

The solid state polymerization may be carried out at a temperature of 195 to 230 ° C and a pressure of 0.2 to 2.0 torr or under a nitrogen atmosphere.

The polyester resin of the present invention prepared using the above composition and method may have an intrinsic viscosity (IV) of 0.74 to 1.0 dl / g, a Color L value of 77 or more, a Color b value of 2.0 or less, a glass transition temperature Tg) of 80 占 폚 or higher is suitable for use in the production of various containers as a polyester resin.

Hereinafter, the present invention will be described in more detail with reference to specific production examples, examples and comparative examples.

Manufacturing example

The molten polymerizer used in the production of the polyester resin used was a batch type polymerizer. The reactor contained one esterification reactor, one condensation polymerization reactor, and a reactor equipped with a cutting system. The esterification reaction was conducted for 3 to 4 hours, The polycondensation reaction was carried out for 2 to 4 hours, and the temperature was raised to 285 DEG C while the pressure was reduced so that the final degree of vacuum was 1.0 torr or less to prepare a polyester resin. In the solid phase polymerization reactor, a batch type reactor in which solid phase polymerization was carried out at a reaction temperature of 225 ° C. and a pressure of 0.4 torr or less for 6 to 8 hours was used.

Example  One

87 mol% of monoethyleneglycol and 1 mol% of 1,1,1-tris (4-hydroxyphenyl) ethane (1,1,1-tetramethylphenol) were added to the dicarboxylic acid compound consisting of 97 mol% of terephthalic acid and 3 mol% 13 mol% of tris (4-hydroxyphenyl) ethane, THPE) was added at a molar ratio of 1.2, and 20 ppm of triethyl phosphate (based on the amount of P element) phosphoric acid compound based on the total weight of the polyester resin 30 ppm of cobalt acetate as a compound (based on the amount of Co element) and 20 ppm of a titanium composite metal oxide catalyst (based on the amount of Ti element) of formula (1) were quantitatively dissolved in ethylene glycol and then added to the slurry production step. The esterification reaction temperature is 260 ° C. When the tower temperature sensor for measuring the temperature of distilled water generated in the reaction process is lowered to 95 ° C, the reaction is stopped and the oligomer produced by the esterification reaction is introduced into the polycondensation reactor .

The pressure of the polycondensation reactor was reduced to 1.0 torr or less for 60 minutes and the polycondensation reaction was carried out by increasing the temperature from 260 ° C to 280 ° C. The reacted reaction product was pulverized through a waterbath, And then a transparent chip-type polyester resin was prepared.

Example  2

A polyester resin was prepared in the same manner as in Example 1 except that 13 mol% of THPE was added in the first stage of the polycondensation (PC) reaction.

Example  3

A polyester resin was prepared in the same manner as in Example 1 except that 10 mol% of THPE was added to the slurry in Example 1 above.

Example  4

A polyester resin was prepared in the same manner as in Example 1 except that 10 mol% of THPE was added in the first stage of the polycondensation (PC) reaction.

Example  5

A polyester resin was prepared in the same manner as in Example 1, except that 5 mol% of THPE was added to the slurry in Example 1.

Example  6

A polyester resin was prepared in the same manner as in Example 1 except that 5 mol% of THPE was added in the first stage of the polycondensation (PC) reaction.

Example  7

A polyester resin was prepared in the same manner as in Example 1 except that 3 mol% of THPE was added to the slurry in Example 1 above.

Example  8

A polyester resin was prepared in the same manner as in Example 1 except that 3 mol% of THPE was added in the first stage of the polycondensation (PC) reaction.

Comparative Example  One

A polyester resin was prepared in the same manner as in Example 1, except that 100 mol% of monoethylene glycol in Example 1 (THPE was not added) into the slurry.

Comparative Example  2

A polyester resin was prepared in the same manner as in Example 1 except that 2 mol% of THPE was added to the slurry in Example 1.

Comparative Example  3

A polyester resin was prepared in the same manner as in Example 1 except that 17 mol% of THPE was added to the slurry in Example 1.

Test Example

(PC) reaction time, intrinsic viscosity (liquid phase, solid phase and intrinsic viscosity increase value? IV), color (L, b) value, glass transition temperature (Tg) The results are shown in Table 1 below.

(1) Intrinsic Viscosity (I.V, ASTM 4603)

Phenol and 1,1,2,2-tetrachloroethanol in a weight ratio of 6: 4, 0.4 g of the polyester resin to be measured was put in a reagent, and after dissolving for 90 minutes, a solution of Ubbelohde Transfer it to a viscometer and keep it in a 30 ° C thermostat for 10 minutes. Use a viscometer and an aspirator to determine the number of drops of solution. The number of drops of the solvent was also found by the same method, and then R.V. Value and I.V. Values were calculated. In the following equation, C represents the concentration of the sample.

[Equation 1]

R.V. = Samples falling in water / solvent drops in seconds

&Quot; (2) "

I.V. = 1/4 (R.V.-1) / C + 3/4 (In R.V./C)

(2) Color evaluation

L * a * b * (CIE 1976) in the colorimetric system by using a colorimeter (SA-2000) after filling the glass cell with the chip after removing moisture in the air of 50 g of the polyester resin to be measured. And b * were measured.

(3) Glass transition temperature (Tg)

The polyester polymer was annealed in a differential scanning calorimeter (DSC) at 300 DEG C for 5 minutes, cooled to room temperature, and then heated at a rate of 10 DEG C / min to measure a glass transition temperature (Tg).

Referring to Table 1, in the case of the polyester prepared using the composition containing THPE in a specific content range (Examples 1 to 8), the polymerization time was shortened by forming a polyester having a branch structure other than the conventional linear structure The color value was improved (the color coordinate L value increased and the color coordinate b value decreased), and the melt viscosity was increased. This increase in melt viscosity has an advantage in that it can be molded to an equivalent degree with a low intrinsic viscosity as compared to conventional linear structure polyesters. In addition, it was confirmed that the glass transition temperature was extremely high and the heat resistance was excellent. On the other hand, these effects were independent of the timing and position of THPE injection during polymerization.

On the other hand, it was confirmed that when THPE was not contained (Comparative Example 1) and THPE content was too low (Comparative Example 2), the heat resistance was increased and the color improving effect was insufficient. In addition, when the THPE content was excessively high (Comparative Example 3), normal polymerization could not be performed due to gel formation, and it was impossible to evaluate the properties of the process.

The preferred embodiments of the present invention have been described in detail above. It will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

Accordingly, the scope of the present invention is defined by the appended claims rather than the foregoing detailed description, and all changes or modifications derived from the meaning, range, and equivalence of the claims are included in the scope of the present invention Should be interpreted.

Claims (8)

Wherein the molar ratio of the diol compound to the dicarboxylic acid or ester compound thereof is 1.05 to 1.4,
The diol compound is replaced by a multifunctional compound having at least 3 hydroxyl groups of 1 to 15 mol%
Wherein the composition comprises 10 to 40 ppm of a phosphorus compound (based on the amount of the P element), 1 to 40 ppm of a color improving agent, and 5 to 30 ppm of a polyester polycondensation catalyst (based on the amount of a metal element). The method according to claim 1,
Wherein the polyester polycondensation catalyst comprises a titanium composite metal oxide represented by the following formula 1 or 2:
[Chemical Formula 1]

(2)

(In the formula (2), n is an integer of 2 to 20) 3. The method of claim 2,
Wherein the titanium composite metal oxide catalyst is mixed with ethylene glycol. The method according to claim 1,
The dicarboxylic acid compound may be at least one selected from the group consisting of phthalic acid, terephthalic acid, isophthalic acid, dibromoisophthalic acid, sodium sulfoisophthalic acid, phenylenedioxy dicarboxylic acid, 4,4'-diphenyldicarboxylic acid, 4,4'-diphenyl ketone dicarboxylic acid, 4,4'-diphenoxyethane dicarboxylic acid, 4,4'-diphenyl sulfone dicarboxylic acid, and 4,4'-diphenyl sulfone dicarboxylic acid. 2,6-naphthalenedicarboxylic acid, and 2,6-naphthalenedicarboxylic acid. 3. The method of claim 2,
Wherein the dicarboxylic acid compound comprises 90 to 100 mol% of the terephthalic acid and 0 to 10 mol% of the isophthalic acid. The method according to claim 1,
The diol compound is at least one selected from the group consisting of monoethylene glycol, diethylene glycol, 1,3-propylene diol, 1,4-butylene diol, 1,4-cyclohexane dimethanol and neopentyl glycol By weight based on the total weight of the composition. The method according to claim 1,
The phosphorus compound may be phosphoric acid, trimethyl phosphate, triethyl phosphate, tri-n-butyl phosphate, trioctyl phosphate, triphenyl phosphate, tricresyl phosphate, methyl acid phosphate, ethyl acid phosphate, isopropyl phosphate, At least one member selected from the group consisting of ethyl phosphate, monobutyl phosphate, dibutyl acid phosphate, dioctyl phosphate, triethylene glycol acid phosphate and triethyl phosphonoacetate,
Wherein the color improving agent is a mixed dye of a blue dye and a red dye or a mixed dye of a violet dye and a red dye. The method according to claim 1,
Wherein the polyester resin has a glass transition temperature (Tg) of 80 DEG C or more, a color coordinate L value of 77.0 or more, and a color coordinate b value of 2.0 or less.