KR100513118B1 - Method for preparing polyester resin copolymerized with 1,4-cyclohexanedimethanol at enhanced condensation polymerization rate - Google Patents

Abstract

The present invention relates to a method for producing a polyester resin copolymerized with 1,4-cyclohexanedimethanol having excellent polycondensation reaction rate, and more particularly, to ethylene glycol and 1,4-cyclohexanedimethanol for terephthalic acid. Adding a total glycol component so as to be 1.2 to 3.0 in a molar ratio to perform esterification; And polycondensation reaction with a high polycondensation reaction rate comprising the step of using a titanium compound as a polycondensation catalyst to the esterification reactant and adding a metal soap-based lubricant to the polycondensation reaction. It relates to a method for producing an ester resin. According to the production method of the present invention, by using a metal soap-based lubricant, the productivity of the copolymer resin as a final product can be increased by improving the reaction rate of the polycondensation reaction without affecting the color of the resin.

Description

Method for preparing polyester resin copolymerized with 1,4-cyclohexanedimethanol having excellent polycondensation reaction rate {Method for preparing polyester resin copolymerized with 1,4-cyclohexanedimethanol at enhanced condensation polymerization rate}

The present invention relates to a method for preparing a polyester resin copolymerized with 1,4-cyclohexanedimethanol having excellent polycondensation reaction rate, and more particularly, to a metal soap-based lubricant in the presence of a titanium-based catalyst during polycondensation reaction. The present invention relates to a method for producing a polyester resin copolymerized with 1,4-cyclohexanedimethanol having an excellent polycondensation reaction rate that can increase productivity by adding a reaction rate.

Recently, copolymerized polyester resins copolymerized with 1,4-cyclohexanedimethanol have become commercial polyesters used as important materials in the fields of packaging materials, molded articles, films and the like. Conventionally, a method of preparing a polyester resin using an antimony catalyst has been mainly used. However, recently, a reactivity and transparency is improved by replacing a part or the entire amount of the antimony catalyst, which requires excessive use, due to its relatively low catalytic activity. Methods to improve and avoid the gray color peculiar to antimony catalysts are being actively researched. In addition, conventionally, a method of preparing a polyester resin by adding 1,4-cyclohexanedimethanol during a transesterification reaction using dimethyl terephthalate has been used. Attention is focused on the manufacturing process.

For example, US Pat. No. 5,340,907 discloses esterification of dicarboxylic acid and glycol components in the presence of catalysts and inhibitors consisting essentially of Mn, Zn, Ti, P and organic blue toning and A method for producing a colorless copolymer resin useful as a sheet material having a thickness of about 1.6 to 25.4 mm by carrying out a polycondensation reaction is disclosed.

In addition, U.S. Patent No. 5,681,918 discloses improvement of the color of the resin through esterification and polycondensation reaction of terephthalic acid, ethylene glycol and 1,4-cyclohexanedimethanol in the presence of a titanium catalyst and a phosphorus stabilizer or cobalt compound. A method for producing a copolyester resin copolymerized with 1,4-cyclohexadimethanol is disclosed.

However, in the above-described prior art, research has been mainly focused on the color and transparency of the resin, but does not specifically present a method for increasing the productivity of the final resin by improving the reactivity in manufacturing the copolyester resin. .

Meanwhile, metal soap-based lubricants are called heat stabilizers, internal lubricants, softeners, and the like, and are added in an amount of about 0.1 to 10 parts by weight in the post-processing process of various resins such as polyvinyl chloride resin and engineering plastics. It is a general additive used to increase stability.

Examples of the use of such metal soap-based lubricants are introduced in, for example, Korean Patent Publication Nos. 2002-0038499, 2001-0064935, 1999-0055612, 1997-0025948, and the like. According to the above patents, metal soap-based lubricants are not used for the polymerization of resins and are used to improve the processability of resins in post-processing processes. Particularly, these metal soap-based lubricants include barium stearate, calcium stearate, zinc stearate, and lead stearate. , Cadmium stearate, stearamide, and the like.

Therefore, in the present invention, as a result of research and review to improve the productivity compared to the production of a polyester resin according to the prior art, when the metal soap-based lubricant is added together with the titanium-based catalyst in the polycondensation reaction step, the reaction rate can be improved The present invention was completed based on this.

Accordingly, an object of the present invention is to prepare a polyester resin copolymerized with 1,4-cyclohexanedimethanol, and to improve productivity by increasing the polycondensation reaction rate, 1,4-cyclohexane having excellent polycondensation reaction rate. It is to provide a method for producing a polyester resin copolymerized with dimethanol.

In order to achieve the above object, a method for preparing a polyester resin copolymerized with 1,4-cyclohexanedimethanol of the present invention has a total glycol component including ethylene glycol and 1,4-cyclohexanedimethanol in a molar ratio of 1.2 with respect to terephthalic acid. Adding to 3.0 to make an esterification reaction; And a polycondensation reaction by using a titanium compound as the polycondensation catalyst to the esterification reactant, and adding a metal soap-based lubricant.

Hereinafter, the present invention will be described in more detail.

As described above, according to the present invention, by adding a metal soap-based lubricant during the preparation of the polyester resin copolymerized with 1,4-cyclohexanedimethanol by improving the polycondensation reaction rate without affecting the color of the resin Provided is a method for preparing a polyester resin copolymerized with 1,4-cyclohexanedimethanol having an excellent polycondensation reaction rate capable of increasing productivity.

Looking at the method for producing a polyester copolymerized with 1,4-cyclohexanedimethanol using terephthalic acid according to the present invention, first, the total glycol component including ethylene glycol and 1,4-cyclohexanedimethanol is molar ratio to terephthalic acid. 1.2 to 3.0 was added to carry out the esterification reaction. At this time, the esterification is preferably carried out under a temperature of 230 ~ 260 ℃ and pressure conditions of 1.0 ~ 3.0kg / ㎠.

After the first step of the esterification reaction is completed, the second step of the polycondensation reaction is carried out. Meanwhile, prior to starting the polycondensation reaction of the second step, a polycondensation catalyst is added to the esterification reaction product obtained from the esterification reaction, and in addition to this, a stabilizer and a colorant may be selectively added as necessary. Can be.

In general, the polycondensation catalyst may be appropriately selected from titanium, germanium and antimony compounds. In the present invention, among these, tripropyl titanate, tetrapropyl titanate and tetra are particularly suitable as catalysts for use as polycondensation catalysts of polyester resins in which 1,4-cyclohexanedimethanol is copolymerized with 15% or more by weight of terephthalic acid. It is preferable to use a titanium compound such as butyl titanate and a copolymer of titanium dioxide and silicon dioxide, and the amount of addition is preferably 10 to 100 ppm based on the amount of titanium element relative to the weight of the final polymer. In this case, the amount of catalyst added may affect the color of the final polymer and thus may vary depending on the desired color and the stabilizer and colorant used. The term 'final polymer' used in the present invention refers to 1,4-cyclohexane. It means polyester resin copolymerized with dimethanol.

Examples of the stabilizer include phosphoric acid, trimethyl phosphate, triethyl phosphate and triethyl phosphonoacetate, and the amount of the stabilizer is preferably 10 to 150 ppm relative to the weight of the final polymer based on the amount of phosphorus element. In addition, examples of the colorant added to improve the color include conventional colorants such as cobalt acetate and cobalt propionate, and the amount thereof is suitably 20 to 100 ppm relative to the final polymer weight.

In addition to the above-described titanium-based catalyst, phosphorus-based stabilizer and colorant, a metal soap-based lubricant is essentially added as an additive for improving the reactivity of the polycondensation reaction. Metal soap-based lubricants used in the present invention may be selected from the group consisting of barium stearate, calcium stearate, zinc stearate, lead stearate, cadmium stearate, stearamide, and mixtures thereof. At this time, the amount of the metal soap-based lubricant is preferably 0.1 to 1 parts by weight with respect to 100 parts by weight of the final polymer, the reaction rate of the effect of improving the reaction is negligible if the addition amount is less than 0.1 parts by weight, the reaction is greater than 1 part by weight There is a problem that adversely affects the speed improvement.

Next, the second step, which is the polycondensation step, is carried out under a temperature of 260 to 290 ° C and a reduced pressure of 400 to 0.1 mmHg. The polycondensation step is carried out for the required time until the desired intrinsic viscosity is reached, the reaction temperature is generally 260 ~ 290 ℃, preferably 270 ~ 280 ℃. In addition, the polycondensation reaction is carried out under a reduced pressure of 400 ~ 0.1mmHg in order to remove the glycol generated as a by-product can finally obtain a polyester resin copolymerized with 1,4-cyclohexanedimethanol.

As described above, according to the present invention, by adding a metal soap-based lubricant with a titanium-based catalyst in the polycondensation reaction step, there is an advantage that can increase the productivity of the resin produced therefrom by improving the reaction rate.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the scope of the present invention is not limited thereto. In addition, unless otherwise indicated in the following Example and a comparative example, a unit "part" means a "weight part."

Example 1

After adding 996 parts of terephthalic acid, 294 parts of 1,4-cyclohexanedimethanol, 618 parts of ethylene glycol, and phosphorus stabilizer to 80 ppm of the final amount of phosphorus based on the amount of phosphorus in a 3L reactor equipped with a stirrer and an outlet condenser, nitrogen After raising the pressure to 2.0 kg / cm 2, the reaction was gradually increased to 255 ° C. in the reactor. The water generated at this time was discharged out of the system to esterify, and when the generation and outflow of water were completed, the esterification reaction obtained therefrom was transferred to a polycondensation reactor equipped with a stirrer, a cooling condenser, and a vacuum system. The titanium-based catalyst was added to the esterification reactant to be 55 ppm relative to the final polymer amount based on the titanium element amount, and the cobalt-based colorant was added to be 80 ppm relative to the final polymer amount based on the cobalt element amount. Add 0.1 parts by weight of barium stearate as an additive, and increase the internal temperature from 240 ° C to 275 ° C, and remove the ethylene glycol while performing a low vacuum reaction from the normal pressure to 50mmHg for 40 minutes. After slowly depressurizing and ethylene glycol was removed under high vacuum for 150 minutes, the reaction was carried out until the intrinsic viscosity became about 0.78, and then it was discharged and cut into chips. The intrinsic viscosity, color, and reaction time of the 1,4-cyclohexanedimethanol copolyester resin thus prepared were measured as follows, and the results are shown in Table 1 below.

◎ Intrinsic Viscosity (IV): Measured by dissolving 0.1150% in 150 ° C ortho-chlorophenol using a Ubelrod viscometer in a thermostat at 35 ° C.

◎ Color: Measured using Pacific Scientific's Colorgard System.

Example 2

In the polycondensation reaction, a 1,4-cyclohexanedimethanol copolymer polyester resin was obtained in the same manner as in Example 1 except that 0.2 weight part of barium stearate was added to the titanium crab catalyst to proceed the polycondensation reaction. The intrinsic viscosity, color, and reaction time thereof were measured as described above, and the results are shown in Table 1 below.

Example 3

In the polycondensation reaction, a 1,4-cyclohexanedimethanol copolymer polyester resin was obtained in the same manner as in Example 1 except that 0.1 part by weight of calcium stearate was added to the titanium crab catalyst to proceed the polycondensation reaction. The intrinsic viscosity, color, and reaction time thereof were measured as described above, and the results are shown in Table 1 below.

Example 4

In the polycondensation reaction, 1,4-cyclohexanedimethanol copolymer polyester resin was obtained in the same manner as in Example 1, except that 0.2 parts by weight of calcium stearate was added to the titanium crab catalyst to advance the polycondensation reaction. The intrinsic viscosity, color, and reaction time thereof were measured as described above, and the results are shown in Table 1 below.

Comparative Example 1

1,4-cyclohexanedimethanol copolymer poly was carried out in the same manner as in Example 1, except that the polycondensation reaction was carried out in the polycondensation reaction without the addition of a titanium-based catalyst and a metal soap-based lubricant. An ester resin was obtained and its intrinsic viscosity, color and reaction time were measured as described above and the results are shown in Table 1 below.

Intrinsic Viscosity (dl / g) Color (Col-b) Response time (minutes) Example 1 0.78 5 146 Example 2 0.76 5 135 Example 3 0.76 6 105 Example 4 0.76 5 95 Comparative Example 1 0.78 4 198

As shown in Table 1, when the polycondensation reaction is carried out by adding barium stearate or calcium stearate as the metal soap-based lubricant according to the present invention, the reaction at the same intrinsic viscosity as compared to the case where the metal soap-based lubricant is not added It was found that the polycondensation reaction rate was further improved without any effect on the color of the resin at the end, and as a result, a greater amount of copolyester resin could be produced at the same time.

As described above, according to the present invention, by adding a metal soap-based lubricant with a titanium catalyst in the polycondensation reaction step, the reaction rate of the polycondensation reaction is improved without affecting the color of the resin. The productivity of the polyester resin copolymerized with dimethanol can be increased.

Claims (5)

Adding a total glycol component, including ethylene glycol and 1,4-cyclohexanedimethanol, to terephthalic acid at a molar ratio of 1.2 to 3.0 to perform esterification; And Using a titanium-based compound as a polycondensation catalyst to the esterification reaction, and adding a metal soap-based lubricant to the polycondensation reaction of the polyester resin copolymerized 1,4-cyclohexane dimethanol Manufacturing method. The metal soap-based lubricant is selected from the group consisting of barium stearate, calcium stearate, zinc stearate, lead stearate, cadmium stearate, stearamide, and mixtures thereof, the content of which is 1,4-cyclohexane It is 0.1-1 weight part with respect to 100 weight part of polyester resins in which dimethanol was copolymerized, The manufacturing method of the polyester resin copolymerized with 1, 4- cyclohexane dimethanol. The method of claim 1, wherein the polycondensation reaction is carried out in the presence of a stabilizer and a colorant. The method of claim 1, wherein the esterification reaction of 1, 4- cyclohexane dimethanol copolymerized polyester resin, characterized in that carried out at a temperature of 230 to 260 ℃ and pressure conditions of 1.0 to 3.0kg / ㎠ Way. The method of claim 1, wherein the polycondensation reaction is performed at a temperature of 260 to 290 ° C and a reduced pressure of 400 to 0.1 mmHg. .