KR20160052260A - Poly cyclohexylenedimethylene terephthalate and method for synthesizing thereof - Google Patents

Abstract

The process for producing the polycyclohexanedimethyl terephthalate resin of the present invention is characterized in that,
(A) a dicarboxylic acid compound composed of (a) dimethyl terephthalate, terephthalic acid or a mixture thereof and (b) a diol compound having a content of 1,4-cyclohexane dimethanol of 80 mol% or more based on the total molar amount of diol compound, Wherein the molar ratio of the carboxylic acid compound to the diol compound is from 1: 1.1 to 1: 2.0, (c) trimethylolpropane or trimellitic acid hydride based on the mole number of the dicarboxylic acid compound an oligomer is produced at a temperature of from 285 DEG C to 320 DEG C by adding an oxidizing stabilizer to an amount of 50 to 1000 mu mol% C, under reduced pressure, to provide a modified PCT resin having improved crystallization speed, melting point and intrinsic viscosity, and good color tone.

Description

TECHNICAL FIELD [0001] The present invention relates to a polycyclohexylenedimethylene terephthalate and a method for synthesizing the polycyclohexylenedimethylene terephthalate resin,

The present invention relates to a process for producing a polycyclohexanedimethyl terephthalate resin.

Polycyclohexylenedimethylene terephthalate (hereinafter referred to as "PCT resin") is a type of polyalkylene terephthalate resin.

The polyalkylene terephthalate resin is a polyester resin which is obtained by esterifying and polymerizing terephthalic acid (TPA) or dimethyl terephthalate (DMT), which is an acid component, with an alkylene diol compound as an alcohol component The polymer compound produced by the reaction is generally referred to. The polyalkylene terephthalate resin is characterized by excellent physical properties such as heat resistance, transparency, strength, processability and the like compared with polymeric resins such as PP and PE.

The polyalkylene terephthalate resin may be selected from the group consisting of polyethylene terephthalate ("PET") resin, polytrimethylene terephthalate ("PTT") resin, polybutyl terephthalate Polybutylene terephthalate ("PBT") resin, and polycyclohexanedimethylene terephthalate ("PCT") resin. The PET resin contains ethylene glycol (ethylene glycol) as the alcohol component (diol), 1,3-propanediol as the PTT resin, 1,4-butanediol as the PBT resin, , And 1,4-cyclohexane dimethanol (CHDM) is used as the PCT resin.

The polyalkylene terephthalate resin is generally in the form of a homopolymer composed of a single alcohol component. However, depending on the alcohol component, the physical properties such as the melting point, crystallinity, heat resistance, and strength of the polymer resin are different, A polyester copolymer having two or more diols as an alcohol raw material or two or more homopolymers may be blended together.

PET resin has a high melting point (256 DEG C) and is excellent in physical properties such as transparency and strength, and is widely used as a general plastic such as a plastic container. However, since the crystallization rate is relatively high There is a certain limit in the use of engineering plastics which require a high degree of crystallinity.

PBT resin is suitable for engineering plastics because of its higher crystallization rate and better physical properties than PET resin. However, it has a melting point of 225 ℃, which is relatively low compared to PET resin (256 ℃) have.

On the other hand, the PCT resin has a melting point of 290 ° C or higher and is superior to PBT resin (225 ° C) or PET resin (256 ° C), has excellent heat resistance, high crystallinity and dimensional stability and is classified as superplastic . The production cost is also low. PCT resin is used as special connector, relay (relay), surface mounting socket used for electricity and electronics, harness socket and engine room cover for automobile engine room, and backlight reflector material of LED panel.

The PCT resin is produced by subjecting terephthalic acid (TPA) or dimethyl terephthalate (DMT) as an acid component and 1,4-cyclohexanedimethanol (CHDM) as an alcohol component to an esterification reaction or an ester exchange reaction in the presence of a titanium- Are obtained.

PCT resin was first developed and produced by US EASTMAN, sold to DUPONT in 2000, and currently marketed under the trade name TRITAN ^TM , and manufactured by SK Chemicals in Korea.

The PCT resin can be prepared by using 1,4-cyclohexane dimethanol as an acid component and a PCT resin prepared by using 1,4-cyclohexane dimethanol as a single component, as well as 1,4-cyclohexane dimethanol as an acid component and a heterogeneous alcohol component such as other ethylene glycol And a polyester copolymer (co-polyester) containing as a subcomponent.

A commercially available PCTG resin (Poly Cyclohexylene dimethylene Terephthalate Glycol) is a copolymer comprising 1,4-cyclohexane dimethanol as a main component in diol in an amount of 50 mol% or more, preferably 80 mol% or more, and ethylene glycol as a subcomponent. PCTG is included in the PCT system of the present invention.

PCT resins, particularly homopolymer PCT resins, are high heat resistant resins having a melting point of 290 ° C or higher. Therefore, the PCT resin has a higher crystallization degree than PET, PBT, etc. However, since the injection molding temperature is higher than 300 ° C., the finished product does not harden quickly after the injection molding, so that the working speed can not be increased.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and it is an object of the present invention to provide a method for producing polycyclohexylenedimethylene terephthalate resin with improved crystallization speed.

The present invention relates to a process for producing a diol compound, which comprises (a) a dicarboxylic acid compound comprising (a) a dicarboxylic acid compound composed of dimethyl terephthalate, terephthalic acid or a mixture thereof, (b) a diol having a content of 1,4-cyclohexane dimethanol of 80 mol% Wherein the molar ratio of the dicarboxylic acid compound to the diol compound is from 1: 1.1 to 1: 2.0, (c) trimethylolpropane (TMP) or tri 50 to 1000 mu mol% of trimellitic anhydride (TMA) or a mixture thereof, and (d) an oxidative stabilizer are introduced, and the mixture is subjected to an esterification reaction or an ester exchange reaction at 270 DEG C to 300 DEG C under a nitrogen stream, And polycondensation reaction is carried out at a reduced pressure of 285 to 320 DEG C to obtain a polycyclohexanedimethyl terephthalate resin.

The diol compound other than 1,4-cyclohexanedimethanol may be at least one selected from ethylene glycol, 1,3-propanediol and 1,4-butanediol, and the content thereof may be determined based on the total number of moles of the diol compound Or less and 20 mol% or less.

In order to improve the impact resistance, the PCT resin of the present invention can be polymerized by adding a small amount of isophthalic acid (isophthalic acid), which is an isomer to the dicarboxylic acid component. At this time, the content of isophthalic acid is preferably 0.1 to 1.0 mol% based on the number of moles of the dicarboxylic acid compound.

The catalyst may be selected from the group consisting of titanium oxide, tetraethyl titanate, tetra-n-propyl titanate, tetra-isopropyl titanate, tetra-n-butyl titanate, tetra-isobutyl titanate, , Tin of dibutyltine oxide, manganese acetate, cobalt acetate, calcium acetate, and zinc acetate.

The oxidation stabilizer may be at least one selected from the group consisting of tri-methylphosphate, tri-ethylphosphate, neopentyldiaryloxytrilephosphate, tri-phenylphosphate, triethylphosphonoacetate, (Phosphoric acid) or phosphorous acid (phosphoric acid).

The PCT resin prepared according to the method of the present invention has an improved crystallization speed and increased viscosity as compared with the conventional PCT resin, so that it is possible not only to increase the speed of the injection molding operation under the same conditions but also to increase the melting point, Is also improved.

In the present invention, the term "polycyclohexanedimethyl terephthalate resin (PCT resin)" includes not only PCT resin as a homopolymer but also PCT polyester copolymer (Copolyester). The PCT resin means that 1,4-cyclohexane dimethanol alone is polymerized as a diol component, and the PCT polyester copolymer includes 1,4-cyclohexane dimethanol, ethylene glycol, 1,3-propanediol, 1,4 -Butanediol and the like are polymerized together. In the present invention, the ethylene glycol, 1,3-propanediol and 1,4-butanediol have a content of 20 mol% or less based on the total molar amount of diol. In the present invention, the PCT resin includes a polycyclohexylene dimethylene terephthalate glycol (PCTG) resin having a 1,4-cyclohexane dimethanol content of 80 mol% or more and an ethylene glycol content of 20 mol% or less in the diol component.

As a result of conducting a PCT resin modification study to increase the crystallization rate of the PCT resin, the present inventors have found that when synthesizing by adding a small amount of trimethylolpropane or trimellitic anhydride to a conventional PCT monomer component, It was confirmed that the crystallization rate was improved by lowering the melt index significantly compared to the conventional PCT resin to which these components were not added and the melting point and intrinsic viscosity of the modified PCT resin of the present invention were lower than those of the conventional PCT resin And the color was also good. Thus, the present invention was achieved.

The present invention relates to a process for producing a diol compound, which comprises (a) a dicarboxylic acid compound comprising (a) a dicarboxylic acid compound composed of dimethyl terephthalate, terephthalic acid or a mixture thereof, (b) a diol having a content of 1,4-cyclohexane dimethanol of 80 mol% The compound is added so that the molar ratio of the dicarboxylic acid compound to the diol compound is 1: 1.1 to 1: 2.0, (c) trimethylolpropane or trimellitic acid hydrolyzate is added, based on the mole number of the dicarboxylic acid compound, 50 to 1000 mu mol% of trimellitic anhydride or a mixture thereof, and (d) an oxidative stabilizer are introduced into an oligomer by an esterification reaction or an ester exchange reaction at 270 DEG C to 300 DEG C under a nitrogen stream and a catalyst, Wherein the polycyclohexanedimethyl terephthalate resin is subjected to polycondensation under reduced pressure at a temperature of from -20 ° C to 320 ° C.

The PCT resin of the present invention can be obtained by using dimethyl terephthalate, terephthalic acid or a mixture thereof as an acid component, a PCT homopolymer synthesized by 1,4-cyclohexane dimethanol alone as an alcohol (diol) component, -Cyclohexanedimethanol as a main component (80 mol% or more), and ethylene glycol, 1,3-propanediol, 1,4-butanediol, etc. as subcomponents (20 mol% or less) lt; / RTI > The PCT homopolymer resin has a high crystallinity and the PCT polyester copolymer also has 1,4-cyclohexane dimethanol as a main component, thus exhibiting a high crystallization property.

In order to shorten the reaction time and improve the quality of the obtained PCT polymer, the molar ratio of the carboxylic acid compound to the diol compound is preferably 1: 1.1 to 1: 2.0.

The most significant feature of the present invention is to significantly modify the PCT resin by the addition of a small amount of trimethylolpropane or trimellitic anhydride or a mixture thereof.

Since trimethylol propane has three alcohol groups in the molecule, it reacts with terephthalic acid or dimethyl terephthalate upon polymerization to form a three-dimensional branch structure or a linkage structure. The trimellitic anhydride reacts with the diol during polymerization due to the breakdown of the anhydride in the molecule and has three carboxyl groups in the molecule to form a three-dimensional branch or crosslinked structure.

The content of trimethylolpropane or trimellitic anhydride or a mixture thereof is preferably 50 to 1000 mu mol% based on the molar amount of the dicarboxylic acid compound. The above content is about 30 to 300 ppm with respect to the total weight of PCT. When these components are less than 50 mu mol%, the modifying effect is lowered, and when it is more than 1000 mu mol%, the impact strength of the rigid submarine may be lowered due to intermolecular crosslinking or branch structure.

In order to improve the impact resistance, the PCT resin of the present invention can be polymerized by adding a small amount of isophthalic acid (isophthalic acid), which is an isomer to the dicarboxylic acid component. At this time, the content of isophthalic acid is preferably 0.1 to 1.0 mol% based on the number of moles of the dicarboxylic acid compound. When the isophthalic acid is introduced at 0.1 mol% or less, the impact strength can be lowered, and when it is 1.0 mol% or more, the high crystallinity of the PCT may be deteriorated.

Examples of the oxidation stabilizer include tri-methylphosphate, tri-ethylphosphate, neopentyldiaryloxytryphosphate, tri-phenylphosphate, triethylphosphonoacetate, Phosphoric acid, phosphorous acid and the like may be used, and trimethyl phosphate is particularly preferable. The oxidation stabilizer is preferably added in an amount of 0.005 to 0.05 part by weight based on 100 parts by weight of the entire PCT component to be added, but it can be changed according to need. The introduction time of the oxidation stabilizer may be added at the beginning of the esterification reaction or the transesterification reaction or at the end of the reaction, but it is more preferable that the addition is carried out at the end of the esterification reaction.

Examples of the catalyst include titanium oxide, tetraethyl titanate, tetra-n-propyl titanate, tetraisopropyl titanate, tetra-n-butyl titanate, tetra-isobutyl titanate, and butyl- Tin of dibutyltine oxide, manganese acetate, cobalt acetate, calcium acetate, and zinc acetate. Of these, a titanium-based catalyst is preferable, and titanium oxide is more preferable. The amount of the catalyst is preferably 0.005 to 0.05 part by weight based on 100 parts by weight of the entire PCT component to be added, but it may be changed according to need. It is preferable that the introduction timing of the catalyst is introduced at the beginning of esterification or transesterification.

In the PCT polymerization method, the raw materials are put into a reactor and subjected to esterification reaction or ester exchange reaction to produce an oligomer having an appropriate molecular weight, followed by a second polycondensation reaction.

Since the reaction conditions for the esterification reaction or the transesterification reaction are different from each other, they are preferably carried out in separate reactors.

The reaction temperature of the first reaction, that is, esterification or transesterification, is preferably 270 ° C to 300 ° C. When the temperature is lower than 270 ° C, the oligomer may be solidified after the esterification reaction, There is a possibility that problems may be caused even during transportation. If the esterification reaction temperature is 300 ° C or higher, the resulting oligomer may be deteriorated or the chain connected thereto may be broken again and decomposed. The reaction temperature is more preferably 280 ° C to 290 ° C. The reaction pressure in the esterification or transesterification reaction is preferably 0.5 to 3 kg / cm ² when the reaction is carried out under pressure, and the oligomer is produced more easily and the reaction time is also shortened.

The resultant oligomer is transferred to a condensation polymerization reactor, which is a secondary reaction, and polycondensation is carried out under an appropriate amount of an oxidizing stabilizer. The condensation polymerization reaction temperature is preferably 285 ° C to 320 ° C. When the condensation reaction temperature is lower than 285 ° C, the condensation reaction may be solidified and difficulty in ejection may occur after completion of the reaction. If the condensation reaction temperature is higher than 320 ° C, the polymer may deteriorate or the flowability of the polymer may deteriorate due to too rapid flow of the polymer after completion of the reaction. In the above-mentioned condensation polymerization process, it is necessary to remove the initial overcharged alcohols and moisture and other impurities to prevent depolymerization. Therefore, the pressure in the condensation polymerization reactor is required to be as high as 0.01 to 1.0 mmHg. If it is reacted at 1.0 mmHg or more, there is a high possibility of causing depolymerization due to insufficient impurities.

The PCT polymerization method of the present invention can be carried out by batch method (batch method), but continuous polymerization method is preferable for mass production.

Hereinafter, the present invention will be described in detail by way of examples.

Example 1.

100 g (0.60 mol) of terephthalic acid, 125 g (0.87 mol) of 1,4-cyclohexanedimethanol, 0.02 g (150 mu mol) of trimethylolpropane and 0.01 g of titanium oxide catalyst were fed into the primary condensation polymerization reactor, kg / cm < ² >) was slowly heated to 280 DEG C for 6 hours while stirring under a nitrogen stream, until the water completely drained.

When the water was completely removed, 0.015 g of trimethyl phosphate (oxidative stabilizer) was diluted in 1 liter of water, transferred to a secondary condensation polymerization reactor, and slowly heated to 310 DEG C under a nitrogen stream for 3 hours. At this time, in order to remove excess alcohol component, water and other impurities, PCT condensation polymerization was completed while keeping the pressure in the reactor at 0.5 mmHg or less.

Example 2.

100 g (0.52 mol) of dimethyl terephthalate, 95 g (0.66 mol) of 1,4-cyclohexane dimethanol, 0.02 g (150 mu mol) of trimethylol propane and 0.01 g of titanium oxide catalyst were fed into the primary condensation polymerization reactor, The procedure of Example 1 was followed to complete PCT condensation polymerization.

Example 3.

(0.30 mol) of terephthalic acid, 50 g (0.26 mol) of dimethylterephthalate, 116 g (0.80 mol) of 1,4-cyclohexanedimethanol, 0.03 g (223 mu mol) of trimethylolpropane, And the polymerization was carried out in the same manner as in Example 1 to complete the PCT condensation polymerization.

Example 4.

PCT condensation polymerization was completed in the same manner as in Example 1 except that the content of trimethylol propane was doubled to 0.04 g (298 mu mol) as compared with Example 1. [

Example 5.

PCT condensation polymerization was completed in the same manner as in Example 2, except that 0.02 g (104 mu mol) of trimellitic acid hydride was added instead of trimethylol propane.

Example 6.

Compared with Example 3, PCT condensation polymerization was completed in the same manner as in Example 3, except that 0.01 g (75 mu mol) of trimethylolpropane and 0.01 g (52 mu mol) of trimellitic acid hydride were added as an additive.

Comparative Examples 1 to 3.

In order to compare with Examples 1 to 3 in which trimethylol propane and / or trimellitic acid hydride were added, it was carried out without adding trimethylol propane and trimellitic acid hydride in the above Examples to obtain PCT condensation polymerization .

The reaction components and contents of Examples 1 to 6 and Comparative Examples 1 to 3 are summarized in Table 1 below.

Example Comparative example One 2 3 4 5 6 One 2 3
mountain
ingredient TPA
(mol) 100g
(0.60) - 50g
(0.30) 100g
(0.60) - 50g
(0.30) 100g
(0.60) - 50g
(0.30) DMT
(mol) - 100g
(0.52) 50g
(0.26) - 100g
(0.52) 50g
(0.26) - 100g
(0.52) 50g
(0.26) Dior
ingredient CHDM
(mol) 125g
(0.87) 95g
(0.66) 116g
(0.80) 125g
(0.87) 95g
(0.66) 116g
(0.80) 125g
(0.87) 95g
(0.66) 116g
(0.80)
additive TMP
(μmol) 0.02 g
(150) 0.02 g
(150) 0.03 g
(223) 0.04 g
(298) - 0.01 g
(75) - - - TMA
(μmol) - - - - 0.02 g
(104) 0.01 g
(52) - - -

* DMT: dimethyl terephthalate, TPA: terephthalic acid, CHDM: 1,4-cyclic nucleic acid dimethanol, TMP: trimethylolpropane, TMA: trimellitic acid hydride

Examples 7 to 10 and Comparative Examples 4 to 6. (PCTG resin)

Unlike the PCT homopolymers produced in Examples 1 to 6 above,

To prepare a PCT polyester copolymer (PCTG) which is polymerized with 1,4-cyclohexanedic acid dimethanol (80 mol% or more based on the total molar amount of diol) and ethylene glycol (20 mol% or less based on the total molar amount of diol) The components and the contents shown in Table 2 were fed into a reactor and carried out in the same manner as in Example 1 to complete the polymerization of PCTG.

Example Comparative example 8 9 10 4 5 6
mountain
ingredient TPA
(mol) 100g
(0.60) 100g
(0.60) 100g
(0.60) 100g
(0.60) 100g
(0.60) 100g
(0.60) IPA
(mol) - - 1g
(0.006) - - 1g
(0.006)
Dior
ingredient CHDM
(mol) 105g
(0.78) 105g
(0.78) 105g
(0.78) 105g
(0.78) 105g
(0.78) 105g
(0.78) EG
(mol) 5.4 g
(0.087) 8.0 g
(0.129) 8.0 g
(0.129) 5.4 g
(0.087) 8.0 g
(0.129) 8.0 g
(0.129)
additive TMP
(μmol) 0.02 g
(150) 0.01 g
(75) - - - - TMA
(μmol) - 0.01 g
(52) 0.02 g
(104) - - -

Properties Intrinsic viscosity (cP) 0.71 0.72 0.74 0.67 0.67 0.69 Melting point (캜) 284 283 283 280 279 277 Color (L) 90 91 93 86 86 89      (b) 3.2 3.4 3.0 3.7 4.2 3.6 Melt Index 4 3 3 22 27 24

TPA: terephthalic acid, CHDM: 1,4-cyclohexane dimethanol, EG: ethylene glycol, TMP: trimethylol propane, TMA: trimellitic acid hydride

Physical property experiment

The physical properties of the PCT resin prepared in Examples and Comparative Examples of the present invention were measured by the following methods.

(1) Intrinsic viscosity measurement

The PCT resin of the present example was dissolved in an ortho-chlorophenol solvent at a concentration of 1.2 g / dl and then measured with a Ubbelohde viscometer at 30 ° C. The specific viscosity was measured according to the following formula, and the intrinsic viscosity was measured.

* Viscosity ( η _sp ) = (t - t ₀ ) / t ₀

(Where t is the time it takes for the solvent to pass through the viscometer internal time constant; t ₀ is the time it took the solution to pass through the same section)

* Intrinsic viscosity [ ? ] = {(1 + 4 A? _Sp ) ^1/2 -1} / 2 A ? C

(At this time, A is 0.247 as Huggins constant and c is 1.2 g / dl as concentration value.

(2) Crystalline melting point

The crystalline melting point was measured using a differential scanning calorimeter (Perkin Elmer, Pyris 1 DSC ^TM ) under the following conditions, and the peak value of the endothermic peak derived from the melting of the crystal was defined as a crystalline melting point.

* Measuring temperature: 0 to 300 ° C

* Heating rate: 10 ° C / min

(3) Color of resin (L value, b value)

The PCT resin was crystallized by heat treatment at 150 캜 for 60 minutes, and L value and b value were measured using a spectrophotometer (Nippon Denshoku, ASA 1 ^TM ).

(4) Melt Index

The melt index was measured using an extrusion type plastometer. The melt index was calculated by applying a load of 2160 ± 10 g (2.16 kgf) and measuring the flow rate at 300 ° C.

The physical properties measured by the above method are shown in Tables 3 and 4 below.

Example Comparative example One 2 3 4 5 6 One 2 3
mountain
ingredient TPA
(mol) 100g
(0.60) - 50g
(0.30) 100g
(0.60) - 50g
(0.30) 100g
(0.60) - 50g
(0.30) DMT
(mol) - 100g
(0.52) 50g
(0.26) - 100g
(0.52) 50g
(0.26) - 100g
(0.52) 50g
(0.26) Dior
ingredient CHDM
(mol) 125g
(0.87) 95g
(0.66) 116g
(0.80) 125g
(0.87) 95g
(0.66) 116g
(0.80) 125g
(0.87) 95g
(0.66) 116g
(0.80)
additive TMP
(μmol) 0.02 g
(150) 0.02 g
(150) 0.03 g
(223) 0.04 g
(298) - 0.01 g
(75) - - - TMA
(μmol) - - - - 0.02 g
(104) 0.01 g
(52) - - -

Properties Intrinsic viscosity (cP) 0.68 0.66 0.67 0.65 0.64 0.65 0.65 0.63 0.64 Melting point (캜) 289 287 289 290 289 292 285 283 284 Color (L) 88 87 90 92 87 90 86 86 88      (b) 3.2 3.8 3.0 3.2 3.5 3.2 4.0 4.1 3.8 Melt Index 3 4 3 2 3 2 25 30 20

* DMT: dimethyl terephthalate, TPA: terephthalic acid, CHDM: 1,4-cyclic nucleic acid dimethanol, TMP: trimethylolpropane, TMA: trimellitic acid hydride

Example Comparative example 8 9 10 4 5 6
mountain
ingredient TPA
(mol) 100g
(0.60) 100g
(0.60) 100g
(0.60) 100g
(0.60) 100g
(0.60) 100g
(0.60) IPA
(mol) - - 1g
(0.006) - - 1g
(0.006)
Dior
ingredient CHDM
(mol) 105g
(0.78) 105g
(0.78) 105g
(0.78) 105g
(0.78) 105g
(0.78) 105g
(0.78) EG
(mol) 5.4 g
(0.087) 8.0 g
(0.129) 8.0 g
(0.129) 5.4 g
(0.087) 8.0 g
(0.129) 8.0 g
(0.129)
additive TMP
(μmol) 0.02 g
(150) 0.01 g
(75) - - - - TMA
(μmol) - 0.01 g
(52) 0.02 g
(104) - - -

Properties Intrinsic viscosity (cP) 0.68 0.66 0.67 0.67 0.67 0.69 Melting point (캜) 289 287 289 280 279 277 Color (L) 88 87 90 86 86 89      (b) 3.2 3.4 3.0 3.7 4.2 3.6 Melt Index 4 4 4 22 27 24

TPA: terephthalic acid, CHDM: 1,4-cyclohexane dimethanol, EG: ethylene glycol, TMP: trimethylol propane, TMA: trimellitic acid hydride

As shown in Tables 3 and 4, the PCT resin of the present invention, in which trimethylol propane, trimellitic acid hydride, or a mixture thereof was added and polymerized according to the above example, is a conventional PCT resin polymerized without these additives The melting point was increased by about 4 ° C, and the intrinsic viscosity was also significantly improved. The results are shown in Table 1. In addition, the color L value is higher than that of the comparative example, indicating that the transparency is improved.

Claims (5)

(A) a dicarboxylic acid compound composed of (a) dimethyl terephthalate, terephthalic acid or a mixture thereof and (b) a diol compound having a content of 1,4-cyclohexane dimethanol of 80 mol% or more based on the total molar amount of diol compound, The molar ratio of the carboxylic acid compound to the diol compound is from 1: 1.1 to 1: 2.0,
(c) 50 to 1000 mu mol% of trimethylolpropane or trimellitic anhydride or a mixture thereof based on the mole number of the dicarboxylic acid compound, and (d)
An oligomer is produced by an esterification reaction or an ester exchange reaction at 270 ° C to 300 ° C under a nitrogen gas stream and a catalyst and then condensation polymerization is carried out under reduced pressure at 285 ° C to 320 ° C.
A process for producing a polycyclohexanedimethyl terephthalate resin.
3. The method according to claim 1 or 2,
In the diol compound, the diol compound other than 1,4-cyclohexane dimethanol is at least one selected from ethylene glycol, 1,3-propanediol, and 1,4-butanediol, and the content thereof is 20 Mol% or less.
A process for producing a polycyclohexanedimethyl terephthalate resin.
3. The method according to claim 1 or 2,
Characterized by further comprising 0.1 to 1.0 mol% of isophthalic acid based on the molar amount of the dicarboxylic acid compound to carry out an esterification reaction or an ester exchange reaction and a condensation polymerization reaction.
A process for producing a polycyclohexanedimethyl terephthalate resin.
3. The method according to claim 1 or 2,
The catalyst may be at least one selected from the group consisting of titanium oxide, tetraethyl titanate, tetra-n-propyl titanate, tetra-isopropyl titanate, tetra-n-butyl titanate, tetra-isobutyl titanate, butyl- And at least one member selected from the group consisting of dibutyltine oxide, manganese acetate, cobalt acetate, calcium acetate, and zinc acetate.
A process for producing a polycyclohexanedimethyl terephthalate resin.
3. The method according to claim 1 or 2,
The oxidation stabilizer may be at least one selected from the group consisting of tri-methylphosphate, tri-ethylphosphate, neopentyldiaryloxytrilephosphate, tri-phenylphosphate, triethylphosphonoacetate, Phosphoric acid, phosphoric acid, or phosphorous acid.
A process for producing a polycyclohexanedimethyl terephthalate resin.