KR102155097B1 - Poly(cyclohexylenedimethylene terephthalate) having improved heat resistance and the method manufacturing the same with improved - Google Patents

Abstract

The present invention relates to a polycyclohexylenedimethylene terephthalate (PCT) resin having improved heat resistance compared to a conventional polycyclohexylenedimethylene terephthalate (PCT) resin and a method of manufacturing the same.
The present invention is to improve heat resistance by adding an alcohol pretreatment process to a general method for preparing a polycitrohexylenedimethylene terephthalate resin, and the polycyclohexylenedimethylene terephthalate resin prepared according to the present method is a conventional polycyclohexylene Compared to the dimethylene terephthalate resin, heat resistance is improved, and since a complex catalyst and a complex stabilizer are used in the manufacturing process of polycyclohexylene dimethylene terephthalate, reactivity deterioration and color defects can be prevented.

Description

Poly(cyclohexylenedimethylene terephthalate) having improved heat resistance and the method manufacturing the same with improved}

The present invention relates to a polycyclohexylenedimethylene terephthalate (PCT) resin with improved heat resistance and a method for manufacturing the same, and more specifically, to a polycyclohexylenedimethylene terephthalate (PCT) resin having improved physical properties than the conventional polycyclohexylenedimethylene terephthalate resin. As it can withstand very high temperatures to replace bars and metals, it can be widely used in LED reflectors, automotive connectors, electric vehicle engine rooms, high heat resistant fibers, high heat resistant films, and electric and electronic fields. In comparison, the present invention relates to a polycyclohexylenedimethylene terephthalate resin and a method of manufacturing the same, which can be applied to various industrialization, as well as being able to be applied to various industrializations by improving flexibility by further improving flexibility.

Polycyclohexylenedimethylene terephthalate resin is generally a kind of polyalkylene terephthalate-based resin, and the polyalkylene terephthalate-based resin is a polyester-based terephthalic acid (TPA), or dimethyl It refers to a polymer compound produced by esterification and polymer polymerization of terephthalate (DMT) and an alkylene diol compound as an alcohol component under a certain catalyst.

These polyalkylene terephthalate-based resins have excellent properties such as heat resistance, transparency, strength, and processability compared to polymer resins such as PP and PE.

These polyalkylene terephthalate resins are polyethylene terephthalate ("PET") resin, polytrimethylene terephthalate ("PTT") resin, and polybutylene terephthalate, depending on the type of alcohol component (diol). Phthalate (Polybutylene terephthalate, “PBT”) resin, polyethylene terephthalate glycol (“PETG”) resin, and polycyclohexylenedimethylene terephthalate (“PCT”) resin. .

PET resin uses ethylene glycol as an alcohol component (diol), PTT resin uses 1,3-propanediol as an alcohol component (diol), and PBT resin uses an alcohol component 1,4-Butanediol is used as (diol), and the PCT resin is 1,4-cyclohexane dimethanol (CHDM) as an alcohol component (diol). use. And recently developed PETG uses ethylene glycol and 1,4-cyclohexane dimethanol (CHDM) as alcohol components.

Polyalkylene terephthalate resins generally have a homopolymer form composed of a single alcohol component, but there are differences in various physical properties such as melting point, crystallinity, heat resistance, and strength of the polymer resin depending on the alcohol component. Depending on the physical properties, it is sometimes produced in the form of a polyester copolymer (Copolyester) containing two or more diols as an alcohol raw material, or a blend of two or more homopolymers.

PET has excellent physical properties, but its melting point is limited, and PBT is also too low to be suitable for use in fine chemicals or functional polymer engineering plastics.Therefore, technology for branding with high melting point resins has been developed. There is a problem in that the thermal decomposition and color may be rapidly deteriorated.

As such, polyalkylene terephthalate-based resins generally have a homopolymer form composed of a single alcohol component, but a technology that improves the crystallization rate while maintaining high heat resistance is required by selecting an appropriate alcohol and synthesizing it into a copolymer. .

Although polycyclohexylenedimethylene terephthalate has been developed for a long time, there are many restrictions on its use. In particular, a suitable use of polycyclohexylenedimethylene terephthalate has not been found, but the use thereof is gradually increasing in the field of functional engineering plastics that require a resin having high heat resistance. For example, with the development of LED TVs and electric vehicles, the need for high heat-resistant resins is increasing (for example, LED TVs are used as light reflectors, electric vehicles are used as connectors), and in fact, the demand is also rapidly increasing. Are doing.

Looking at the properties of the other resins mentioned above, based on homopolymer, which is a single component (single diol), PET resin has a high melting point (256 ℃) and has excellent physical properties such as transparency and strength, so it is widely used in plastic containers. Although widely used as a plastic, there is a limit for engineering plastics that require high crystallinity due to a relatively low crystallization rate.

PBT resin has a higher crystallization rate and superior physical properties than PET resin, making it suitable for engineering plastic applications, but its melting point is 225 ℃, which is relatively low compared to PET resin (melting point 256 ℃), so it is limited in plastic applications requiring heat resistance. have.

On the other hand, PCT resin has a melting point of 285 ℃ or higher and has excellent heat resistance compared to PBT resin (melting point 225 ℃) or PET resin (melting point 256 ℃), has a high crystallization rate, and has excellent dimensional stability. It is classified as a super engineering plastic.

The conventional PCT manufacturing method could not produce a high heat-resistant resin having a melting point of 300° C. or higher, but by using alcohol that has undergone a pretreatment process, a high heat-resistant resin having a melting point of 300° C. or more could be produced.

Here, the pretreatment process is a process in which alcohol is first added to the reactor and an appropriate amount of temperature is raised to filter impurities and moisture through a vacuum. Pretreatment of such alcohols may be carried out in an esterification reactor, or may be previously treated in another pretreatment reactor and then introduced into an esterification reactor. Such alcohols may be used in a reactor, or may be pretreated and introduced in another reactor.

Therefore, for general engineering plastics of heat-resistant resin, there is no doubt that the existing PCT is an excellent resin, but when a resin with higher heat-resistance is required, for example, in the case of LED TV, the melting point is 287 ℃ to maintain more vivid colors without discoloration for a long time. Resins above 300° C. would be much more advantageous than resins of degree. Automotive connectors also have to withstand high heat, but if metal is used, it is contrary to the current global trend of minimizing weight like electric vehicles, so instead of metal, plastic that withstands high temperatures should be used. In this case, a resin with a melting point of 300 ℃ or higher is required. will be.

High heat resistance PCT is the most ideal resin for plastics that must withstand high temperatures in all areas where firefighters wear firefighting suits made of high heat resistant PCT fibers, kitchen gloves, high temperature laboratory gloves, and plastics instead of metals. And the most important point is that it is a resin that withstands high temperatures, but the process of making this resin is easy and has little harm to the human body, and other resins (PPS: heat-resistant resin T _m 278 ℃ -> benzene are used as raw materials) when disposed of by incineration after use. Even after use and use, there is a problem when incineration or landfilling, and iodine is used as a raw material, but iodine among the products can be a bigger problem). It has the advantage of far less harmful gas than special resins. For this reason, the higher the heat resistance, the more it is expected to minimize the weight in place of metal in the future, and the application range will be endless in the field where special resins are used for electricity and electronics.

PCT resin is an esterification reaction or transesterification reaction of terephthalic acid (TPA) or dimethyl terephthalate (DMT) as an acid component and 1,4-cyclohexanedimethanol (CHDM) as an alcohol component in the presence of a titanium-based or tin-based catalyst. It can be obtained by condensation polymerization. PCT resin is a PCT resin prepared with a single component of 1,4-cyclohexanedimethanol as an acid component, as well as 1,4-cyclohexanedimethanol as a main component in the acid component, and heterogeneous alcohols such as other etherene glycols It includes a polyester copolymer containing a component as an auxiliary component.

PCT resins, particularly homopolymer PCT resins, are highly heat-resistant resins having a melting point of 285°C or higher. PCT resins have high crystallinity and high heat resistance compared to PET and PBT, but the melting point of special resins emphasized here requires more than 300℃, which is much higher than that of general PCT resins.

It is an object of the present invention to provide a method for producing a highly heat-resistant polycyclohexylenedimethylene terephthalate-based resin.

The present invention is a step of pretreating alcohol (step 1), introducing the pretreated alcohol, dicarboxylic acid, catalyst, and oxidation stabilizer into an esterification reactor (step 2), stirring and heating the esterification reactor to obtain ester A method for producing a polycyclohexylenedimethylene terephthalate resin comprising the step of performing a chemical reaction (step 3) and carrying out a condensation polymerization reaction by transferring the product of the esterification reaction to a polymer reactor (step 4). to provide.

The first step is characterized in that the pressure is reduced from 760mmHg to 0.01mmHg at a temperature of 80 to 400°C, and is performed for 60 to 240 minutes.

The dicarboxylic acid is characterized in that it contains one or two selected from the group consisting of dimethyl terephthalate and terephthalic acid.

In addition, the dicarboxylic acid further comprises one or more selected from the group consisting of isophthalic acid, naphthalene 2,6 dicarboxylic acid and dimethylisophthalic acid, and 2 to 10 mol based on the total number of moles of dicarboxylic acid It characterized in that it contains %.

According to a preferred embodiment of the present invention, the isophthalic acid may be 0.1 to 10 mol% based on the total number of moles of dicarboxylic acid.

The alcohol is one or two selected from the group consisting of 1,4-cyclohexanedimethanol, ethylene glycol, diethylene glycol, 1,4-butanediol, 1,3-propanediol, neopentyl glycol, and trimethylolpropane. It is characterized in that it is an alcohol of more than one species.

The alcohol is characterized in that it contains 90 mol% or more of 1,4-cyclohexanedimethanol based on the total number of moles of alcohol.

It is characterized in that the molar ratio of the dicarboxylic acid and the alcohol is 1:1.1 to 1:2.5.

The catalyst is titanium oxide, tetraethyl titanate, tetra-n-propyl titanate, tetra-isopropyl titanate, tetra-n-butyl titanate, tetra-isobutyl titanate, butyl-isopropyl titanate, dibutyl It is characterized in that it is one or two or more selected from the group consisting of tin oxide, manganese acetate, cobalt acetate, calcium acetate, and zinc acetate.

It is characterized in that the catalyst is added 10 to 200 ppm based on the total weight of the reactants.

The oxidation stabilizer is characterized in that it is one or two or more selected from the group consisting of trimethyl phosphate, triethyl phosphate, neopentyldiaryloxytrile phosphate, triphenyl phosphate, triethylphosphonoacetate, phosphoric acid and phosphorous acid.

The oxidation stabilizer is characterized in that 10 to 200 ppm is added based on the weight of the total reactant.

In the third step, the pre-treated alcohol, dicarboxylic acid, catalyst, and oxidation stabilizer are stirred under a nitrogen stream until completely mixed, and the final reaction temperature of the esterification reaction is 260 to 300°C. At this time, in order to completely remove oxygen in the reactor, nitrogen is introduced, pressure is applied so that the nitrogen pressure is 1 to 2 kg/cm ² , vented, pressurized again, and exhausted to completely remove oxygen in the reactor. Can be removed. Because the transesterification reaction, esterification reaction, or polymer polymerization temperature is very high, even a very small amount of oxygen is oxidized and color deteriorates or pyrolysis occurs.By completely removing oxygen in the reactor, color degradation and thermal decomposition can be prevented as much as possible. I can.

In this way, heating for the esterification reaction is performed in a state where oxygen is blocked. If heating is performed too quickly, there is a risk of scattering and color change. Conversely, if heated too slowly, the reaction rate is slowed and productivity is only reduced. In addition, the probability of not forming a polymer in the polymer reaction increases. Therefore, in the starting stage, it is effective to increase the temperature by 7 to 10 ℃ per minute, and after 20 minutes, it is ideal to raise the temperature to 3 to 5 ℃ per minute.

It is characterized in that the esterification reaction is performed by transferring 35 to 65% by weight of the product of the third step to a polymer reactor, and adding the pretreated alcohol, dicarboxylic acid, catalyst and oxidation stabilizer to the remaining amount.

The fourth step may be carried out in a vacuum of 0.001 Torr to 2.0 Torr, preferably 0.01 to 2.0 Torr, more preferably 0.05 to 1.0 Torr, after transferring the product of step 3 to a polymer reactor using nitrogen pressure. When transferring the esterified product to the polymer reactor, it must be transferred by pressurization with nitrogen. If too high pressure is applied here, 0.5 kg/cm ² is appropriate because it may cause burns or splash on the wall.

The fourth step is characterized in that it is made at 290 to 320 ℃.

The polycyclohexylenedimethylene terephthalate resin has an intrinsic viscosity of 0.4 to 1.2 dl/g.

The polycyclohexylenedimethylene terephthalate resin has a color coordinate L value (col-L) of 80 or more and a b value (col-b) of 5 or less.

In addition, an object of the present invention is to provide a polycyclohexylenedimethylene terephthalate prepared by the above production method.

The present invention has an effect of improving heat resistance by adding a pretreatment process by diversifying alcohol types to a general polycyclohexylenedimethylene terephthalate resin manufacturing method, and improving flexibility by diversifying alcohol types.

In addition, the polycyclohexylenedimethylene terephthalate resin prepared according to the present method can prevent reactivity degradation and color defects by using a flexible complex catalyst and a complex stabilizer compared to the conventional polycyclohexylenedimethylene terephthalate resin.

This makes it easy to apply to electrical and electronic connectors, sockets, SMTs, etc., which have suffered from development of uses, and can be used for heat sinks, automobile motor covers, temperature controllers, etc., and thus, its utilization is expected to increase.

In the present invention, the term "polycyclohexylenedimethylene terephthalate resin (PCT resin)" refers to polycyclohexylenedimethylene terephthalate resin as well as polycyclohexylenedimethylene terephthalate PCT polyester which is a homopolymer. Copolyesters are also included. Polycyclohexylenedimethylene terephthalate resin refers to a diol component polymerized with 1,4-cyclohexanedimethanol alone, and polycyclohexylenedimethylene terephthalate polyester copolymer is 1,4-cyclohexane In addition to dimethanol, ethylene glycol, 1,3-propanediol, 1,4-butanediol neopentyl glycol, 1,6-hexanediol, and the like are polymerized together with a multi-component polycyclohexylenedimethylene terephthalate resin.

The present invention is to improve the durability of the polycyclohexylenedimethylene terephthalate resin, improve durability, and to use it as a substitute for metals such as electric, electronic, and electric vehicles. As a result, more emphasis was placed on the selection of polyhydric alcohols, complex catalysts, and complex stabilizers that can have a good effect on reactivity or color change while using an alcohol component rather than the conventional polycyclohexylenedimethylene terephthalate monomer component.

In addition, the present invention is characterized in that an alcohol pretreatment process is applied to increase the heat resistance of polycyclohexylenedimethylene terephthalate resin so that it can be widely used in electric/electronic products, heat-resistant fibers, and automobile parts.

The polycyclohexylenedimethylene terephthalate resin of the present invention has an Intrinsic Viscosity value of 0.4 to 1.2 dl/g, a color coordinate of more than col-L 80 and less than col-b 5, and has excellent flexibility and heat resistance. Having improved characteristics, the method for preparing the polycyclohexylenedimethylene terephthalate resin of the present invention will be described in more detail below.

In the polycyclohexylenedimethylene terephthalate resin of the present invention, the step of pretreating alcohol (step 1), the step of introducing the pretreated alcohol, dicarboxylic acid, catalyst, and oxidation stabilizer into the esterification reactor (step 2) , Stirring and heating the esterification reactor to perform an esterification reaction (step 3), and transferring the product of the esterification reaction to a polymer reactor to perform a polycondensation reaction (step 4).

In the present invention, the alcohol is selected from the group consisting of 1,4-cyclohexanedimethanol, ethylene glycol, diethylene glycol, 1,4-butanediol, 1,3-propanediol, neopentyl glycol, and trimethylolpropane. It may be one or two or more polyhydric alcohols.

In a suitable example of the present invention, the alcohol includes 1,4-cyclohexanedimethanol, and additionally, ethylene glycol, diethylene glycol, 1,4-butanediol, 1,3-propanediol, neopentyl glycol, trimerol It may contain one or two or more polyhydric alcohols selected from the group consisting of propane. At this time, 1,4-cyclohexanedimethanol may be 80 mol% or more, more preferably 90 mol% or more, based on the total number of moles of alcohol. In the diol compound, the diol compounds other than 1,4-cyclohexanedimethanol are ethylene glycol, diethylene glycol, 1,4-butanediol, 1,3-propanediol, neopentyl glycol, trimethylolpropane, and 1, It may be one or more selected from the group consisting of 6-hexanediol, and the content thereof may be contained in an amount of 2 to 10 mol% or less based on the total number of moles of the diol compound.

In order to improve the heat resistance of the polycyclohexylenedimethylene terephthalate resin, the present invention is characterized in that it undergoes a first step of pretreating alcohols as raw materials. The first step is decompressed from 760 mmHg to 0.01 mmHg at a temperature of 80 to 400°C, preferably 100 to 350°C, and may be performed for 60 to 240 minutes. At this time, the pressure is more preferably 100 ~ 500mmHg close to the vacuum state.

After the first step of pretreating the alcohol, the second step of introducing the pretreated alcohol, dicarboxylic acid, catalyst, and oxidation stabilizer into the esterification reactor is performed.

According to an embodiment of the present invention, the dicarboxylic acid and the diol compound are added in a molar ratio of 1:1.1 to 1:2.5 in the esterification reactor, and based on the number of moles of the diol compound, ethylene glycol, diethylene glycol, 2 to 10 mol% of one or more alcohols selected from the group consisting of 1,4-butanediol, 1,3-propanediol, neopentyl glycol, trimethylolpropane, and 1,6-hexanediol may be added.

The dicarboxylic acid is characterized in that it contains one or two selected from the group consisting of dimethyl terephthalate and terephthalic acid. In addition, the dicarboxylic acid compound may further include one or more selected from the group consisting of isophthalic acid, naphthalene 2,6 dicarboxylic acid, and dimethylisophthalic acid in addition to dimethyl terephthalate and terephthalic acid. The content of the dicarboxylic acids included may be 2 to 10 mol% based on the total number of moles of the dicarboxylic acid compound. In addition, according to a preferred embodiment of the present invention, the isophthalic acid may be 0.1 to 10 mol% based on the total number of moles of dicarboxylic acid.

After the raw materials are added in this way, the oxidation stabilizer and the thermal stabilizer are added, and air is blocked from entering the reactor where the catalyst is added again under nitrogen purge. At this time, nitrogen is added to completely remove oxygen in the reactor, pressure is applied so that the nitrogen pressure is 2 kg/cm ² , vented, pressurized again, and exhausted, then the oxygen in the reactor will be completely removed. There can be. Because the esterification reaction or polymer polymerization temperature is very high, even if there is a very small amount of oxygen, color deterioration or pyrolysis occurs due to oxidation.By completely removing oxygen in the reactor as described above, color degradation and pyrolysis can be prevented as much as possible.

The polycyclohexanedimethylene terephthalate-based resin of the present invention may be polymerized by further containing a small amount of isophthalic acid as a dicarboxylic acid component in order to improve impact resistance. Here, the content of isophthalic acid is 0.1 to 10 mol%, more preferably 0.1 to 5 mol% and most preferably 0.1 to 1.0 mol% based on the number of moles of the dicarboxylic acid compound.

In order to obtain the polycyclohexylenedimethylene terephthalate resin of the present invention, the selection of a catalyst is very important, and the following types of catalysts are helpful in the reaction. Titanium oxide, tetraethyl titanate, tetra-n-propyl titanate, tetra-isopropyl titanate, tetra-n-butyl titanate, tetra-isobutyl titanate, butyl-isopropyl titanate titanium, dibutyl It is preferable to select one or two or more from the group consisting of tin-based tin oxide, acet manganese, acetcobalt, acet calcium, and acet zinc, and at least one or more other than titanium oxide by about 10 to 30 weight % It is effective to mix and use.

The amount of the catalyst added may be 10 to 400 ppm, more preferably 10 to 200 ppm, and most preferably 10 to 100 ppm, based on the weight of the total reactant.

If the catalyst input amount is less than 10 ppm, the reaction time is prolonged, which causes problems for productivity. If the reaction time is too long, the color changes and it may be a problem for polymerizing. If the catalyst input amount exceeds 400 ppm, the reaction time decreases instead of color. Since it is too difficult to control and there is a risk of deterioration when left at room temperature for a long time after commercialization, what kind of catalyst is selected is also an important issue.

For reference, when a catalyst is used, an oxidation stabilizer must also be used, and it is important to use a complex stabilizer as a complex catalyst is used to prevent a decrease in reactivity due to the use of polyhydric alcohol.

Types of the oxidation stabilizer include trimethylphosphate, triethylphosphate, neopentyldiaryloxytrile phosphate, triphenylphosphate, triethylphosphonoacetate, and tri-ethylphosphonoacetate. ), Phosphoric acid, Phosphorous acid may be one or more selected from the group consisting of (Phosphorous acid).

The amount of the oxidation stabilizer is preferably 10 to 500 ppm, more preferably 10 to 200 ppm, and most preferably 20 to 120 ppm based on the weight of the total reactant. If the amount of the oxidation stabilizer is less than 10 ppm, the reaction time decreases, but color control is difficult. If the amount exceeds 500 ppm, color control is possible, but the reaction time is very slow, resulting in lower productivity.

The oxidation stabilizer is more preferably used by mixing the trimethylphosphate (Tri-methylphosphate) and the phosphoric acid (Phosphoric acid), in this case, phosphoric acid (Phosphoric acid) is 10 to 30% by weight of trimethylphosphate (Tri-methylphosphate) Is suitable

After the second step of introducing the raw materials for preparing the polycyclohexylenedimethylene terephthalate resin into the reactor, the reactor is stirred and heated to undergo a third step of performing an esterification reaction. In the third step, the pre-treated alcohol, dicarboxylic acid, catalyst, and oxidation stabilizer are stirred under a nitrogen stream until completely mixed, and the final reaction temperature of the esterification reaction may be 260 to 300°C.

Heating for the esterification reaction is performed while oxygen is blocked. If the temperature is raised too rapidly to increase the temperature, the color may change or scatter before the reaction. That is, if heated too quickly, there is a risk of scattering and color change. Conversely, if heated too slowly, the reaction rate is slowed, resulting in a decrease in productivity as well as a high probability that a polymer cannot be formed in the polymer reaction. Therefore, it is desirable to increase the temperature as little as possible. In the starting stage, an increase of 7 to 10 ℃ per minute is effective, and after the lapse of 20 minutes, it is ideal to raise the temperature to about 3 to 5 ℃ per minute.

It is preferable to adjust the initial point (the point at which the by-product first appears) between 30 and 50 minutes after the start of the reaction, and the reaction time is preferably between 120 and 240 minutes from the start to the end, and the reaction temperature is 260 to 300 ℃ Between, preferably it is preferable to adjust to 270 ~ 300 ℃.

If the initial point appears at a time point less than 30 minutes, the temperature may rise too rapidly to cause scattering, and if it occurs at a time point exceeding 50 minutes, the reaction becomes longer, the monomer reaction becomes too long, and the productivity may eventually decrease.

If the total reaction time is less than 120 minutes, the reaction time is short and the acid value (COOH value) is high, so there is a possibility that the polymer will not become a polymer in the polymer reaction.If the total reaction time exceeds 240 minutes, there is a possibility that the color may change and the productivity decreases, resulting in cost. It can have a negative effect. As for the reaction pressure, when dimethyl terephthalate is selected, the reaction may be carried out at normal pressure, but when terephthalic acid is selected, a pressurized (1 kg/cm ² ) reaction may be performed.

Purging the dicarboxylic acids and alcohols mentioned above with nitrogen for 2 to 3 minutes before starting the reaction in the reactor helps to improve the color.

Transesterification reaction and esterification reaction temperature is 260 ~ 300 ℃, preferably 270 ~ 300 ℃. After the oligomer is produced by esterification at the reaction temperature, the monomer must be transferred to the polymer reactor by pressurization with nitrogen. If too high pressure is applied thereto, 0.5 kg/cm ² is required because it may be burned or splashed on the wall. It is suitable.

According to a preferred embodiment of the present invention, 35 to 65% by weight of the product of the third step is transferred to a polymer reactor, and the pretreated alcohol, dicarboxylic acid, catalyst and oxidation stabilizer are additionally added to the remaining amount for esterification. The reaction can also be carried out.

After the esterification reaction is completed, a four-step process is performed, characterized in that the transferred monomer is subjected to a condensation polymerization reaction under vacuum reaction at 290 to 320°C.

When the monomer obtained through the esterification reaction is transferred to the polymer reactor, it must be transferred as nitrogen so that there is no color change, and it is helpful for fire prevention. In order to react the transferred monomer for a certain period of time and polymerize in a short period of time, a vacuum reaction is required. Since the molecular weight is low initially, it is important to gradually perform a low vacuum reaction.

In the past, the three-way valve was manually fine-tuned, but in recent years, it can reach 760 to 20 mmHg in 30 minutes by using a solenoid valve by a computer program. After that, the polymer can be divided into 20 mmHg to full vacuum in about 10 minutes. This can be an ideal response to anger.

Here, the degree of vacuum is 0.001 to 2 Torr, more preferably 0.01 to 2 Torr, and most preferably 0.05 to 1.0 Torr to prepare a polycyclohexanedimethylene terephthalate resin is good for polymerization, and the reaction during polymer reaction The time can vary greatly depending on the type of resin, catalyst, and stabilizer, but for general polymer reactions, the total polymer reaction time is suitable between 100 and 300 minutes.

The reaction temperature is most preferably polymerized between 290 to 320 °C when preparing the polymer. If it is less than 290 °C, polymerization is difficult and there is a concern of solidification due to a high melting point, and if it exceeds 320 °C, thermal decomposition is likely to occur. Therefore, when the desired viscosity is achieved, it is high-temperature polymerization, so it must be taken out of the reactor as soon as possible after polymerization is completed to prevent pyrolysis as much as possible. If the reaction time is not taken out of the reactor within 30 minutes after the end of the reaction time, the molecular weight and color change due to thermal decomposition may make it difficult to use as a product, so it is important to discharge in a short time.

The experiment in the present invention is carried out by batch polymerization, but when entering the mass production facility, both continuous polymerization and batch polymerization (hereinafter referred to as Bx) can be carried out. Until then, the batch method is preferable, and if it is more than 2000 tons, continuous polymerization (hereinafter referred to as CP) is preferable. C.P. Although it is difficult to set conditions initially in the construction method, once the conditions are set, not only labor costs can be saved, but also quality control is easier, so the color of the C.P method is preferred over the Bx method.

Polycyclohexylenedimethylene terephthalate prepared by the above method has an intrinsic viscosity of 0.4 to 1.2 dl/g, a color coordinate L value (col-L) of 80 or more, and a b value (col-b) of 5 It is characterized by the following.

Hereinafter, the present invention will be described in detail through examples of the present invention, but the scope of the present invention is not limited thereto.

<Alcohol pretreatment process>

Pre-treated 1,4-cyclohexanedimethanol used in Examples 1 to 10 below was prepared by heating at 300° C. for 120 to 200 minutes under a pressure of 100 to 500 mmHg.

Example 1

In the esterification reactor, terephthalic acid 250 g (1.505 mol), the pretreated 1,4-cyclohexanedimethanol 303.5 g (2.105 mol), tetrabutyl titanate 0.221 g, trimethyl phosphate 0.275 g, and the like were purged with nitrogen. Then, to remove oxygen, 1 kg/cm ² pressure was applied with nitrogen, vented, nitrogen pressure was applied again, venting was repeated 3 times, and the reactor lid was covered, then 1 kg/cm ² The pressure is applied with nitrogen and the temperature is raised. The internal temperature is between about 160 ℃ and 180 ℃ so that by-products appear in about 30 to 40 minutes, and the by-products are allowed to flow out. At this time, as the temperature rises, the pressure rises with an automatic Vent system to maintain 1 kg/cm ² . The final reaction temperature of the esterification reaction is set to 260 °C, and the reaction is carried out for about 120 minutes, and when all by-products are leaked, the polymer is transferred to the polymer reactor to perform polymer polymerization. Reaction with high vacuum for about 105 minutes and discharge.

Example 2

In the esterification reactor, terephthalic acid 250 g (1.505 mol), pretreated 1,4-cyclohexanedimethanol 303.5 g (2.105 mol), tetrabutyl titanate 0.177 g, titanium oxide 0.044, trimethyl phosphate 0.275 g, etc. were purged with nitrogen After putting it under (Purge), to remove oxygen, apply 1 kg/cm ² pressure with nitrogen, vent, apply nitrogen pressure again, repeat venting 3 times, cover the reactor lid, and then 1 kg. /cm ² Pressure is applied with nitrogen and the temperature is raised. The internal temperature is between about 160 ℃ and 180 ℃ so that by-products appear in about 30 to 40 minutes, and the by-products are allowed to flow out. At this time, as the temperature rises, the pressure rises with an automatic Vent system to maintain 1 kg/cm ² . The final reaction temperature of the esterification reaction is set to 260 ℃, and the reaction is carried out for about 120 minutes. When all by-products are leaked, the polymer is transferred to the polymer reactor to perform polymer polymerization.At this time, the vacuum degree is set between 0.001 and 1.0 Torr, and the reaction temperature is 315 ℃. Reaction with high vacuum for about 105 minutes and discharge.

Example 3

In the esterification reactor, terephthalic acid 250 g (1.505 mol), pretreated 1,4-cyclohexanedimethanol 303.5 g (2.105 mol), tetrabutyl titanate 0.136 g, titanium oxide 0.084, trimethyl phosphate 0.275 g, etc. were added to nitrogen. After putting it under purge, 1 kg/cm ² pressure is applied with nitrogen to remove oxygen, vented, nitrogen pressure is applied again, venting is repeated three times, and the reactor lid is covered. The pressure of kg/cm ^{2 was} applied with nitrogen and the temperature was raised. The internal temperature is between about 160 ℃ and 180 ℃ so that by-products appear in about 30 to 40 minutes, and the by-products are allowed to flow out. At this time, as the temperature rises, the pressure rises with an automatic Vent system to maintain 1 kg/cm ² . The final reaction temperature of the esterification reaction is set to 260 ℃, and the reaction is carried out for about 120 minutes. When all by-products are leaked, the polymer is transferred to the polymer reactor to perform polymer polymerization.At this time, the vacuum degree is set between 0.001 and 1.0 Torr, and the reaction temperature is 315 ℃. Reaction with high vacuum for about 105 minutes and discharge.

Example 4

In the esterification reactor, terephthalic acid 250 g (1.505 mol), pretreated 1,4-cyclohexanedimethanol 303.5 g (2.105 mol), tetrabutyl titanate 0.088 g, titanium oxide 0.1326, trimethylphosphate 0.22 g, phosphorous acid After putting 0.015 g, etc. under a nitrogen purge, to remove oxygen, 1 kg/cm ² pressure was applied to nitrogen, vented, nitrogen pressure was applied again, venting was repeated three times, and the reactor lid was closed. After covering, 1 kg/cm ² pressure is applied with nitrogen and the temperature is raised. The internal temperature is between about 160 ℃ and 180 ℃ so that by-products appear in about 30 to 40 minutes, and the by-products are allowed to flow out. At this time, as the temperature rises, the pressure rises with an automatic Vent system so that 1 kg/cm ² is maintained. The final reaction temperature of the esterification reaction is set to 260 °C and reacted for about 120 minutes. Polymer polymerization is carried out. At this time, the degree of vacuum is set between 0.001 and 1.0 Torr, and the reaction temperature is set to 315° C., and a high vacuum reaction is performed for about 110 minutes and discharged.

Example 5

In the esterification reactor, terephthalic acid 250 g (1.505 mol), pretreated 1,4-cyclohexanedimethanol 303.5 g (2.105 mol), tetrabutyl titanate 0.044 g, titanium oxide 0.177, trimethylphosphate 0.165 g, phosphorous acid 0.11 g, etc. are put under a nitrogen purge, and then 1 kg/cm ² pressure is applied to nitrogen to remove oxygen, vented, nitrogen pressure is applied again, venting is repeated three times, and the reactor lid is closed. After covering, 1 kg/cm ² pressure is applied with nitrogen and the temperature is raised. The internal temperature is between about 160 ℃ and 180 ℃ so that by-products appear in about 30 to 40 minutes, and the by-products are allowed to flow out. At this time, as the temperature rises, the pressure rises with an automatic Vent system to maintain 1 kg/cm ² . The final reaction temperature of the esterification reaction is set to 260 ℃, and the reaction is carried out for about 120 minutes. When all by-products are leaked, the polymer is transferred to the polymer reactor to perform polymer polymerization.At this time, the vacuum degree is set between 0.001 and 1.0 Torr, and the reaction temperature is 315 ℃. Reaction with high vacuum for about 125 minutes and discharge.

Example 6

In the esterification reactor, terephthalic acid 250 g (1.505 mol), pretreated 1,4-cyclohexanedimethanol 288.4 g (2.00 mol, neopentyl glycol 10.97 g (0.105 mol), tetrabutyl titanate 0.177 g, titanium oxide 0.044 g g, 0.275 g of trimethyl phosphate, etc. are put under a nitrogen purge, and then 1 kg/cm ² pressure is applied with nitrogen to remove oxygen, vented, and nitrogen pressure was again applied and vented three times. After repeating and covering the reactor lid, 1 kg/cm ² pressure is applied with nitrogen and the temperature is raised, the internal temperature is between about 160 ℃ and 180 ℃ so that by-products come out in about 30-40 minutes, and the by-products are allowed to flow out. As the temperature rises, the pressure rises with an automatic Vent system to maintain 1 kg/cm ^2. The final reaction temperature of the esterification reaction is set to 260°C and reacts for about 120 minutes. Polymer polymerization is carried out. At this time, the degree of vacuum is set between 0.001 and 1.0 Torr, and the reaction temperature is 315° C., and a high vacuum reaction is carried out for about 105 minutes and discharged.

Example 7

In the esterification reactor, terephthalic acid 250 g (1.505 mol), the pretreated 1,4-cyclohexanedimethanol 273.14 g (1.897 mol, neopentyl glycol 21.95 g (0.211 mol), tetrabutyl titanate 0.136 g, titanium oxide Put 0.084 g, 0.275 g of trimethyl phosphate, etc. under a nitrogen purge, and then apply 1 kg/cm ² pressure with nitrogen to remove oxygen, vent, and again apply nitrogen pressure and vent. Repeated times, cover the reactor lid, apply 1 kg/cm ² pressure with nitrogen and increase the temperature, and the internal temperature is between about 160 ℃ and 180 ℃ so that by-products come out in about 30-40 minutes, and the by-products are allowed to flow out. At this time, as the temperature rises, the pressure rises with an automatic Vent system so that 1 kg/cm ² is maintained. The final reaction temperature of the esterification reaction is set to 260 °C, and the reaction is carried out for about 120 minutes. Polymer polymerization is carried out. At this time, the degree of vacuum is set between 0.001 and 1.0 Torr, and the reaction temperature is 315° C., and a high vacuum reaction is carried out for about 105 minutes and discharged.

Example 8

To the esterification reactor, terephthalic acid 250 g (1.505 mol), the pretreated 1,4-cyclohexanedimethanol 300.46 g (2.083 mol), trimethylolpropane 2.82 g (0.021 mol), tetrabutyl titanate 0.088 g, Titanium oxide 0.1326 g, trimethyl phosphate 0.222 g, phosphorous acid 0.015 g, etc., were put under a nitrogen purge, and then 1 kg/cm ² pressure was applied to nitrogen to remove oxygen, vented, and nitrogen pressure was applied again. Venting was repeated 3 times, the reactor lid was covered, and then 1 kg/cm ² pressure was applied with nitrogen and the temperature was raised. The internal temperature is between about 160 ℃ and 180 ℃ so that by-products appear in about 30 to 40 minutes, and the by-products are allowed to flow out. At this time, as the temperature rises, the pressure rises with an automatic Vent system to maintain 1 kg/cm ² . The final reaction temperature of the esterification reaction is set to 260 °C, and the reaction is carried out for about 120 minutes, and when all by-products are leaked, the polymer is transferred to the polymer reactor to perform polymer polymerization. Reaction with high vacuum for about 105 minutes and discharge.

Example 9

To the esterification reactor, terephthalic acid 250 g (1.505 mol), the pretreated 1,4-cyclohexanedimethanol 297.42 g (2.062 mol, trimethylolpropane 5.64 g (0.042 mol), tetrabutyl titanate 0.044 g, titanium 0.177 g of oxide, 0.165 g of trimethyl phosphate, 0.011 g of phosphorous acid, etc. are put under a nitrogen purge, and then 1 kg/cm ² pressure is applied to nitrogen to remove oxygen, vented, and nitrogen pressure is again applied and exhausted. Repeat (Vent) three times, cover the reactor lid, apply 1 kg/cm ² pressure with nitrogen, and increase the temperature, so that by-products come out in about 30 to 40 minutes, the inner temperature is between about 160 ℃ and 180 ℃. At this time, when the temperature rises and the pressure rises, the automatic Vent system maintains 1 kg/cm ^2. The final reaction temperature of the esterification reaction is set to 260 ℃ and reacts for about 120 minutes, When all flows out, it is transferred to the polymer reactor for polymer polymerization. At this time, the vacuum level is set between 0.001 and 1.0 Torr, and the reaction temperature is set to 315° C., and a high vacuum reaction is carried out for about 100 minutes and discharged.

Comparative Example 1

Terephthalic acid 250 g (1.505 mol), untreated 1,4-cyclohexanedimethanol 303.5 g (2.105 mol), tetrabutyl titanate 0.221 g trimethyl phosphate 0.275 g, etc. were added to the esterification reactor under nitrogen purge. After adding, to remove oxygen, 1 kg/cm ² pressure was applied with nitrogen, vented, nitrogen pressure was applied again, venting was repeated 3 times, and the reactor lid was covered, followed by 1 kg/cm ² pressure. Was added with nitrogen and the temperature was raised. The internal temperature is between about 160 ℃ and 180 ℃ so that by-products appear in about 30 to 40 minutes, and the by-products are allowed to flow out. At this time, as the temperature rises, the pressure rises with an automatic Vent system to maintain 1 kg/cm ² . The final reaction temperature of the esterification reaction is set to 260 ℃, and the reaction is carried out in about 120 minutes. When all by-products are leaked, the polymer is transferred to the polymer reactor for polymerization.At this time, the vacuum degree is set between 0.001 to 1.0 Torr and the reaction temperature is 300 ℃. Reaction with high vacuum for about 105 minutes and discharge.

Comparative Example 2

To the esterification reactor, terephthalic acid 250 g (1.505 mol), untreated 1,4-cyclohexanedimethanol 303.5 g (2.105 mol), tetrabutyl titanate 0.177 g, titanium oxide 0.044 g, trimethyl phosphate 0.275 g, etc. were added to nitrogen. After putting it under purge, 1 kg/cm ² pressure is applied with nitrogen to remove oxygen, vented, nitrogen pressure is applied again, venting is repeated 3 times, and the reactor lid is covered. The pressure of kg/cm ^{2 was} applied with nitrogen and the temperature was raised. The internal temperature is between about 160 ℃ and 180 ℃ so that by-products appear in about 30 to 40 minutes, and the by-products are allowed to flow out. At this time, as the temperature rises, the pressure rises with an automatic Vent system to maintain 1 kg/cm ² . The final reaction temperature of the esterification reaction is set to 260 ℃, and the reaction is carried out in about 120 minutes. When all by-products are leaked, the polymer is transferred to the polymer reactor for polymerization.At this time, the vacuum degree is set between 0.001 to 1.0 Torr and the reaction temperature is 300 ℃. Reaction with high vacuum for about 105 minutes and discharge.

Comparative Example 3

To the esterification reactor, terephthalic acid 250 g (1.505 mol), untreated 1,4-cyclohexanedimethanol 303.5 g (2.105 mol), tetrabutyl titanate 0.136 g, titanium oxide 0.084 g, trimethyl phosphate 0.275 g, etc. were added to nitrogen. After putting it under purge, 1 kg/cm ² pressure is applied with nitrogen to remove oxygen, vented, nitrogen pressure is applied again, venting is repeated 3 times, and the reactor lid is covered. The pressure of kg/cm ^{2 was} applied with nitrogen and the temperature was raised. The internal temperature is between about 160 ℃ and 180 ℃ so that by-products appear in about 30 to 40 minutes, and the by-products are allowed to flow out. At this time, as the temperature rises, the pressure rises with an automatic Vent system so that 1 kg/cm ² is maintained. The final reaction temperature of the esterification reaction is set to 260 ℃, and the reaction is carried out in about 120 minutes. When all by-products are leaked, the polymer is transferred to the polymer reactor for polymerization.At this time, the vacuum degree is set between 0.001 to 1.0 Torr and the reaction temperature is 300 ℃. Reaction with high vacuum for about 105 minutes and discharge.

Comparative Example 4

In the esterification reactor, terephalic acid 250 g (1.505 mol), untreated 1.4-cyclohexanedimethanol 303.5 g (2.105 mol), tetrabutyl titanate 0.088 g, titanium oxide 0.1326 g, trimethylphosphate 0.22 g, phosphoro Put 0.015 g of acid acid under a nitrogen purge, and then apply 1 kg/cm ² pressure to nitrogen to remove oxygen, vent, apply nitrogen pressure again, and repeat venting 3 times. After covering, 1 kg/cm ² pressure is applied with nitrogen and the temperature is raised. The internal temperature is between about 160 ℃ and 180 ℃ so that by-products appear in about 30 to 40 minutes, and the by-products are allowed to flow out. At this time, as the temperature rises, the pressure rises with an automatic Vent system to maintain 1 kg/cm ² . The final reaction temperature of the esterification reaction is set to 260 ℃, and the reaction is carried out in about 120 minutes. When all by-products are leaked, the polymer is transferred to the polymer reactor for polymerization.At this time, the vacuum degree is set between 0.001 to 1.0 Torr and the reaction temperature is 300 ℃. Reaction with high vacuum for about 125 minutes and discharge.

Comparative Example 5

In the esterification reactor, terephthalic acid 250 g (1.505 mol), untreated 1.4-cyclohexanedimethanol 303.5 g (2.105 mol), tetrabutyl titanate 0.044 g, titanium oxide 0.177 g, trimethyl phosphate 0.165 g, phosphorous acid 0.011 Put g, etc. under a nitrogen purge, then apply 1 kg/cm ² pressure with nitrogen to remove oxygen, vent it, apply nitrogen pressure again, repeat venting 3 times, and cover the reactor lid. Then, 1 kg/cm ² pressure was applied with nitrogen and the temperature was raised. The internal temperature is between about 160 ℃ and 180 ℃ so that by-products appear in about 30 to 40 minutes, and the by-products are allowed to flow out. At this time, as the temperature rises, the pressure rises with an automatic Vent system to maintain 1 kg/cm ² . The final reaction temperature of the esterification reaction is set to 260 ℃, and the reaction is carried out in about 120 minutes. When all by-products are leaked, the polymer is transferred to the polymer reactor for polymerization.At this time, the vacuum degree is set between 0.001 to 1.0 Torr and the reaction temperature is 300 ℃. Reaction with high vacuum for about 125 minutes and discharge.

1. Intrinsic viscosity evaluation

Intrinsic viscosity (IV) was measured for both Examples 1 to 9 and Comparative Examples 1 to 5, and is shown in Table 1.

As a measurement method, put PCT resin in o-chlorophenol at a concentration of 1.2 dl/g in a solvent, heat in a water bath at 70~80℃ for about 60~90 minutes, cool it to room temperature, and then cool it down to room temperature. In order to put it in and measure it using an Ubbelohde viscometer (Capillary Viscometer), the specific viscosity was measured and the intrinsic viscosity was measured in the following manner.

(Where, t is the time it takes for the solvent to pass through a certain section inside the viscometer; t ₀ is the measurement of the time the solution passes through the same section)

(Here, A is 0.247 as a Huggins constant, and c is 1.2 dl/g as a concentration value)

2. Melting point measurement

For both Examples 1 to 9 and Comparative Examples 1 to 5, heating at a rate of 20 °C/min from room temperature to 320 °C using a DSC (Differential Scanning Calorimeter) and the thermal history of the PCT resin (Thermal hi story) Was removed. Thereafter, the resin was cooled, and again heated from room temperature to 32CTC at a rate of 10°C/min to observe the melting point of the resin, and the results are shown in Table 1.

3. Color evaluation

For both Examples 1 to 9 and Comparative Examples 1 to 5, after removing moisture, a chip was filled in a glass cell, and a color difference meter (SA-2000) was used to use CIE-L*a*b* (CIE 1976) colorimeter. L*, and b* were measured and the results are shown in Table 1.

Terephthalic acid/CHDM/NPG/Trimethylolpropane (g) Catalyst(TBT/TiO ₂ ) Reaction time (minutes) IV COL T _m (℃) Stabilizer(TMP/PA) ES PA L/b Example 1 250/303.5/0/0 0.221/0 120 105 0.631 81/4 300 0.275/0 Example 2 250/303.5/0/0 0.177/0.044 120 105 0.639 82/4 301 0.275 Example 3 250/303.5/0/0 0.136/0.084 120 105 0.636 81/5 301 0.275 Example 4 250/303.5/0/0 0.088/0.1326 125 110 0.638 82/4 302 0.22/0.015 Example 5 250/303.5/0/0 0.044/0.177 125 110 0.622 82/4 301 0.165/0.11 Example 6 250/288.4/10.97/0 0.177/0.044 120 105 0.659 82/4 301 0.275 Example 7 250/273.14/21.95/0 0.136/0.084 120 105 0.66 81/5 301 0.275 Example 8 250/300.46/0/2.82 0.088/0.1326 125 110 0.658 82/4 300 0.22/0.015 Example 9 250/297.42/0/5.64 0.044/0.177 125 110 0.662 82/4 301 0.165/0.11 Comparative Example 1 250/303.5/0/0 0.221/0 120 105 0.631 81/5 287 0.275/0 Comparative Example 2 250/303.5/0/0 0.177/0.044 120 105 0.633 82/4 286 0.275 Comparative Example 3 250/303.5/0/0 0.136/0.084 120 105 0.629 80/4 287 0.275 Comparative Example 4 250/303.5/0/0 0.088/0.1326 125 110 0.638 81/4 288 0.22/0.015 Comparative Example 5 250/303.5/0/0 0.044/0.177 125 110 0.632 82/3 287 0.165/0.11

Table abbreviations: CHDM (1,4-Cyclohexane dimethanol), NPG (Neopentylglycol), TMP (Trimethylphosphoric acid), TBT (Tetrabutyltitanate), PA (Phosphorous Acid), COL L (White), b (Yellowish)

Reaction time: ES (Easterification), PA (Polymerization Autoclave)

For the purpose of the experiment, the reaction time was given as much as possible, and the melting point (T _m ) change was determined under the same IV (Intrinsic Viscosity).

Even with the same power value, the IV value showed a slight difference, and the minute difference of the above degree was converted into data because it was safe to treat it as the same product.

In the present invention, in order to diversify the use by preventing the strength and flexibility from falling somewhat compared to the high heat resistance, increasing the intrinsic viscosity IV (Intrinsic Viscosity) can be used for various purposes. Focused on creating.

Referring to Table 1, it can be seen that Examples 1 to 9 according to the manufacturing method of the present invention have higher melting points than Comparative Examples 1 to 5 without pretreatment with alcohol, thereby improving heat resistance.

Claims (19)

Pretreating alcohol (step 1);
Introducing the pretreated alcohol, dicarboxylic acid, catalyst, and oxidation stabilizer into an esterification reactor (step 2);
Stirring and heating the esterification reactor to perform an esterification reaction (step 3); And
Transferring the product of the esterification reaction to a polymer reactor to perform a condensation polymerization reaction (step 4),
The first step is decompressed from 760mmHg to 0.01mmHg at a temperature of 80 to 400°C, and is performed for 60 to 240 minutes,
The alcohol is 1,4-cyclohexanedimethanol,
The dicarboxylic acid is a method for producing a polycyclohexylenedimethylene terephthalate resin, characterized in that terephthalic acid.
delete delete The method of claim 1, wherein the dicarboxylic acid further comprises one or two or more selected from the group consisting of isophthalic acid, naphthalene 2,6 dicarboxylic acid and dimethylisophthalic acid, based on the total number of moles of dicarboxylic acid. A method for producing a polycyclohexylene dimethylene terephthalate resin, characterized in that it contains 2 to 10 mol%.
The method of claim 4, wherein the isophthalic acid is 0.1 to 10 mol% based on the total number of moles of dicarboxylic acid.
delete delete The method for producing a polycyclohexylenedimethylene terephthalate resin according to claim 1, wherein the molar ratio of the dicarboxylic acid and the alcohol is 1:1.1 to 1:2.5.
The method of claim 1, wherein the catalyst is titanium oxide, tetraethyl titanate, tetra-n-propyl titanate, tetra-isopropyl titanate, tetra-n-butyl titanate, tetra-isobutyl titanate, butyl-iso A method for producing a polycyclohexylenedimethylene terephthalate resin, characterized in that it is one or more selected from the group consisting of propyl titanate, dibutyl tin oxide, manganese acetate, cobalt acetate, calcium acetate, and zinc acetate.
The method of claim 1, wherein the catalyst is added 10 to 200 ppm based on the total weight of the reactants.
The method of claim 1, wherein the oxidation stabilizer is one or two or more selected from the group consisting of trimethyl phosphate, triethyl phosphate, neopentyldiaryloxytrile phosphate, triphenyl phosphate, triethylphosphonoacetate, phosphoric acid and phosphorous acid. Method for producing a polycyclohexylene dimethylene terephthalate resin, characterized in that.
The method of claim 1, wherein the oxidation stabilizer is added 10 to 200 ppm based on the total weight of the reactant.
The method of claim 1, wherein in the third step, the pretreated alcohol, dicarboxylic acid, catalyst, and oxidation stabilizer are stirred under nitrogen stream until completely mixed, and the final reaction temperature of the esterification reaction is 260 to 300°C. Method for producing a polycyclohexylene dimethylene terephthalate resin, characterized in that.
The esterification reaction according to claim 1, wherein 35 to 65% by weight of the product of the third step is transferred to a polymer reactor, and the pretreated alcohol, dicarboxylic acid, catalyst, and oxidation stabilizer are additionally added to the remaining amount. Method for producing a polycyclohexylene dimethylene terephthalate resin, characterized in that.

The polycyclohexylenedimethylene terephthalate resin according to claim 1, wherein the fourth step is carried out in a vacuum of 0.01 Torr to 2.0 Torr after transferring the product of the third step to a polymer reactor using nitrogen pressure. Manufacturing method.
The method of claim 1, wherein the fourth step is performed at 290 to 320°C.
The method of claim 1, wherein the polycyclohexylenedimethylene terephthalate resin has an intrinsic viscosity of 0.4 to 1.2 dl/g.
The polycyclohexylenedimethylene terephthalate resin of claim 1, wherein the polycyclohexylenedimethylene terephthalate resin has a color coordinate L value (col-L) of 80 or more and a b value (col-b) of 5 or less. Method for producing a phthalate resin.
Polycyclohexylenedimethylene terephthalate prepared by the method of claim 1.