KR102056291B1 - Process for producing 1,4-cyclohexanedimethanol - Google Patents

Abstract

The present invention relates to a method for producing 1,4-cyclohexane dimethanol having a high ratio of trans-1,4-cyclohexane dimethanol. Method for producing 1,4-cyclohexane dimethanol according to an aspect of the present invention comprises the steps of hydrogenating the 1,4-cyclohexanedicarboxylic acid dialkyl ester to obtain 1,4-cyclohexane dimethanol; And performing isomerization by heating the 1,4-cyclohexane dimethanol in the presence of a molding catalyst comprising nickel and a support.

Description

Process for producing 1,4-cyclohexane dimethanol {Process for producing 1,4-cyclohexanedimethanol}

The present invention relates to a process for the preparation of 1,4-cyclohexane dimethanol. More specifically, the present invention relates to a method for producing 1,4-cyclohexane dimethanol having a high ratio of trans-1,4-cyclohexane dimethanol.

As a method for preparing cyclohexane dimethanol (CHDM), a method of nucleating an aromatic dicarboxylic acid dialkyl ester to produce a cyclohexanedicarboxylic acid dialkyl ester (first reaction), and then hydrogenating the ester group (second reaction) It is common.

As a catalyst applied to each reaction, a catalyst such as palladium, nickel, ruthenium, and rhodium is effective in the first reaction, and copper-chromite, copper oxide / zinc oxide, copper oxide / titanium oxide in the second reaction. It is known that a copper oxide / iron oxide, and a catalyst activated by reduction after modifying these copper catalysts with oxides of barium, magnesium and zinc are effective.

As the reaction method, the fixed bed continuous reaction method is advantageous in terms of productivity and yield compared to the suspension catalyst method. Here, in the fixed-phase continuous reaction method, a molding catalyst is charged into a pressure resistant reactor, hydrogen and a raw material are supplied from the upper part of the reactor under a predetermined temperature and hydrogen pressure to extract the reaction product from the lower part (flow method) or from the lower part of the reactor. And a method of supplying a raw material and extracting a reaction product from the upper portion (ascending method). On the other hand, the suspension catalyst method is a method in which a powder catalyst is suspended in an aromatic dicarboxylic acid diester or a cyclohexanedicarboxylic acid diester and heated under hydrogen pressure.

The cis / trans ratio of CHDM generally depends on the catalyst used in the second reaction and the operating conditions.The ratio of 30/70 for copper chromite catalyst, 65/35 for ruthenium / platinum catalyst and 88/12 for ruthenium / tin catalyst ( Journal of Polymer Science Part A: Polymer Chemistry 48: 2162-2169.

In order to increase the heat resistance of the crystalline polymer when used as a raw material for polymerization, the trans ratio is increased by developing a second reaction catalyst to prepare a CHDM having a high trans content, or by changing the operating conditions in the presence of the second reaction catalyst in use. Although a method of manufacturing an improved CHDM has been developed, a method of adding a new process to an existing process by developing a new process has been studied because of difficulty in changing existing commercial process conditions.

In addition, research has been conducted to obtain a high trans content of CHDM in order to increase the heat resistance of the crystalline polymer when used as a polymerization raw material.

U.S. Patent No. 2,917,549 discloses that an alkali additive is added to CHDM and heat is applied to improve the Trans ratio of CHDM to about 80% by weight. However, the alkali additives are dissolved in CHDM, so a separate recovery process is required, and continuous processes and reuse are not possible, and hazziness occurs when the film is formed by the unrecovered alkali additives during polymer synthesis.

On the other hand, Chinese Patent Publication No. 1,806,913 discloses a content of about 80% by weight of the trans-DMH of CHDM using only the existing process, but the productivity is low and commercialization is difficult due to the batch reaction carried out in one reactor, the reaction temperature is 250 ℃ There have been disadvantages that many side reactions occur.

In addition, U.S. Patent No. 4,999,090 discloses the separation of cis-CHDM and trans-CHDM from existing CHDM by using the difference in boiling point, but the production of high trans (> 90%) CHDM is possible while yield is 50% or less. Very low, there was a problem that cis-rich (~ 60%) CHDM occurs as a residue.

As such, it was necessary to develop a method for preparing 1,4-cyclohexane dimethanol, in which a new process was developed and added to the existing process while maintaining existing commercial process conditions, and no side reactions occurred.

1. US Patent 2,917,549 2. Chinese Patent Publication No. 1,806,913 3. US Patent 4,999,090

The present invention provides a method for producing 1,4-cyclohexane dimethanol having a high ratio of trans-1,4-cyclohexane dimethanol.

Method for producing 1,4-cyclohexane dimethanol according to an aspect of the present invention comprises the steps of hydrogenating the 1,4-cyclohexanedicarboxylic acid dialkyl ester to obtain 1,4-cyclohexane dimethanol; And performing isomerization by heating the 1,4-cyclohexane dimethanol in the presence of a molding catalyst comprising nickel and a support.

In the above, nickel in the molding catalyst comprising the nickel and the support may be 5 to 75% by weight of the total catalyst.

The nickel may be in the form of nickel oxide in the molding catalyst including the nickel and the support.

The content of the molding catalyst including the nickel and the support may be 1 to 20% by weight of the total weight of the 1,4-cyclohexane dimethanol and the molding catalyst including the nickel and the support.

In addition, the support may be at least one selected from the group consisting of transition alumina, alkaline earth metals, and rare earths.

The isomerization reaction can be carried out under conditions further comprising molybdenum.

In addition, the isomerization reaction may be performed at 150 ° C. to 200 ° C., and may be performed for 30 minutes to 3 hours. In addition, the isomerization reaction may be performed at a pressure of less than 10 bar.

Isomerized 1,4-cyclohexane dimethanol according to another aspect of the present invention may be prepared according to the above method, and may comprise at least 74% by weight of trans-1,4-cyclohexane dimethanol.

The method for preparing 1,4-cyclohexane dimethanol according to the present invention has an advantage of producing 1,4-cyclohexane dimethanol having a high ratio of trans-1,4-cyclohexane dimethanol. Therefore, when 1,4-cyclohexane dimethanol having a high ratio of trans-1,4-cyclohexane dimethanol prepared according to the present invention is used as a polymerization raw material, the heat resistance of the crystalline polymer is increased. Can be.

As the invention allows for various changes and numerous embodiments, particular embodiments will be described in detail in the detailed description. However, this is not intended to limit the present invention to specific embodiments, it should be understood to include all transformations, equivalents, and substitutes included in the spirit and scope of the present invention. In the following description of the present invention, if it is determined that the detailed description of the related known technology may obscure the gist of the present invention, the detailed description thereof will be omitted.

The present invention comprises the steps of hydrogenating 1,4-cyclohexanedicarboxylic acid dialkyl ester to obtain 1,4-cyclohexane dimethanol; And it provides a method for producing 1,4-cyclohexane dimethanol comprising the step of performing the isomerization reaction by heating the 1,4-cyclohexane dimethanol in the presence of a molding catalyst comprising nickel and a support.

Hereinafter, a method for preparing 1,4-cyclohexane dimethanol according to a specific embodiment of the present invention will be described in more detail.

According to one embodiment of the invention, the step of hydrogenating 1,4-cyclohexanedicarboxylic acid dialkyl ester to obtain 1,4-cyclohexane dimethanol; And it may be provided a method for producing 1,4-cyclohexane dimethanol comprising the step of performing the isomerization reaction by heating the 1,4-cyclohexane dimethanol in the presence of a molding catalyst comprising nickel and a support.

Previously, in order to prepare 1,4-cyclohexane dimethanol having a high ratio of trans-1,4-cyclohexane dimethanol, existing commercial process conditions had to be changed or side reactions occurred.

Accordingly, the present inventors have confirmed that the addition of the isomerization reaction using a molding catalyst containing nickel and a support has a remarkable effect on improving the trans ratio at a temperature below which the side reaction becomes remarkable.

As such, when the 1,4-cyclohexane dimethanol having a high trans ratio prepared according to the present invention is used as a polymerization raw material, the heat resistance of the crystalline polymer is increased. In particular, in the case of PCT, the Tm is about 287. Increase from 캜 to about 303 캜.

As a method for preparing cyclohexane dimethanol (CHDM), a method of nucleating an aromatic dicarboxylic acid dialkyl ester to produce a cyclohexanedicarboxylic acid dialkyl ester (first reaction), and then hydrogenating the ester group (second reaction) It is common. As a catalyst applied to each reaction, a catalyst such as palladium, nickel, ruthenium, and rhodium is effective in the first reaction, and copper-chromite, copper oxide / zinc oxide, copper oxide / titanium oxide in the second reaction. It is known that a copper oxide / iron oxide, and a catalyst activated by reduction after modifying these copper catalysts with oxides of barium, magnesium and zinc are effective.

As the reaction method, the fixed bed continuous reaction method is advantageous in terms of productivity and yield compared to the suspension catalyst method. Here, in the fixed-phase continuous reaction method, a molding catalyst is charged into a pressure resistant reactor, hydrogen and a raw material are supplied from the upper part of the reactor under a predetermined temperature and hydrogen pressure to extract the reaction product from the lower part (flow method) or from the lower part of the reactor. And a method of supplying a raw material and extracting a reaction product from the upper portion (ascending method). On the other hand, the suspension catalyst method is a method in which a powder catalyst is suspended in an aromatic dicarboxylic acid diester or a cyclohexanedicarboxylic acid diester and heated under hydrogen pressure. Hereinafter, the first reaction and the second reaction will be described in detail.

As a method for producing cyclohexanedimethanol, cyclohexanedicarboxylic acid dialkyl ester can be hydrogenated in the presence of a copper-containing molding catalyst by a fixed phase continuous reaction. In addition, the cyclohexanedicarboxylic acid dialkyl ester may be obtained by nucleating the benzenedicarboxylic acid dialkyl ester using a ruthenium supported molding catalyst.

That is, by carrying out the step of hydrogenating cyclohexanedimethanol to the benzenedicarboxylic acid dialkyl ester (first reaction) and the step of hydrogenating the obtained cyclohexanedicarboxylic acid dialkyl ester in the presence of the copper-containing molding catalyst (second reaction). It is advantageous to obtain.

According to one embodiment, the CHDM is a step of obtaining a 1,4-cyclohexanedicarboxylic acid dialkyl by the fixed-phase continuous reaction, the hydrogenation of terephthalic acid dialkyl in the presence of a ruthenium support molding catalyst (first reaction), And hydrogenating the obtained 1,4-cyclohexanedicarboxylic acid dialkyl by a fixed phase continuous reaction in the presence of a copper-chromite forming catalyst (second reaction) to produce CHDM. have.

Furthermore, in the same manner as in the above embodiment, mono- (mono-), di- (di-), tri- (tri-) or tetra-alkyl esters of cyclohexanecarboxylic acid (particularly cyclohexanedicarboxylic acid dialkyl esters) Can be hydrogenated in the presence of a copper-containing molding catalyst to produce a corresponding alicyclic alcohol (especially CHDM). In this case, when the hydrogenation reaction is carried out while supplying an aliphatic alcohol to the reaction system, With a production method that is economically superior in productivity, high quality CHDM can be produced.

On the other hand, according to another embodiment, a process for obtaining a corresponding cyclohexanedicarboxylic acid dialkyl ester by hydrogenation of an aromatic dicarboxylic acid dialkyl ester using a ruthenium supported molding catalyst by a fixed phase continuous reaction (first reaction) , And the obtained cyclohexanedicarboxylic acid dialkyl ester using a copper-containing molding catalyst, the reaction temperature of 200 ~ 280 ℃, hydrogen pressure 185 ~ 300kgf / ㎠, the supply rate of hydrogen gas at the column rate Hydrogenation under a condition of 1 to 40 cm / sec to prepare a corresponding CHDM (second reaction), and using each of the reaction vessels using a multi-tube pressure reactor equipped with the predetermined catalyst; The feed water to the reactor, which is composed of hydrogen, a reaction raw material, and a reaction product or a solvent, if necessary, is supplied from the upper portion of the reaction mixture, under gas-liquid mixing conditions. By hydrogenation, excess hydrogen and reaction product can be extracted from the bottom to produce CHDM.

The step of performing the isomerization reaction by heating 1,4-cyclohexane dimethanol prepared above in the presence of a molding catalyst comprising nickel and a support is described in detail below. That is, in the present invention, in order to increase the trans ratio of CHDM to about 74% by weight or more, an isomerization step was added to the existing step after the second reaction.

The shape of the shaped catalyst including nickel and the support may be preferably tablet or noodle for the fixed phase reaction, but is not particularly limited. In addition, the surface area of nickel can use 80 m <^2> / g or more.

In the above, nickel in the molding catalyst comprising nickel and the support may be 5 to 75% by weight of the total catalyst.

The nickel may be in the form of nickel oxide in the molding catalyst including the nickel and the support. The nickel oxide is NiO, Ni ₂ O ₃ Nickel oxide forms such as may be possible.

Meanwhile, nickel in the molding catalyst including the nickel and the support may be present in the form of nickel and nickel oxide. Preferably, the content of the nickel and the nickel oxide is about 45 wt%, and the remaining about 55 wt% is the support. It can be diatomaceous earth.

In addition, the content of the molding catalyst comprising the nickel and the support, the content of the molding catalyst comprising the nickel and the support, 1 of the total weight of the molding catalyst comprising the 1,4-cyclohexane dimethanol and nickel and the support To 20% by weight. On the other hand, the content range of the catalyst may be preferable in the case of a batch reaction, the content range of the shaped catalyst is not particularly limited in the case of a continuous reaction.

In addition, the support is not particularly limited, but is preferably capable of imparting basicity to the catalyst, and may be at least one selected from the group consisting of transition alumina, alkaline earth metal, and rare earth.

The isomerization reaction can be carried out under conditions further comprising molybdenum. That is, the nickel catalyst may further contain a metal such as molybdenum as a promoter.

In addition, the isomerization reaction may be performed at 150 ° C. to 200 ° C., and may be performed for 30 minutes to 3 hours. In addition, the isomerization reaction may be performed at a pressure of less than 10 bar.

The temperature at the time of said isomerization reaction is 150-200 degreeC, Preferably 180-200 degreeC is preferable. This is because the isomerization reaction is less likely to occur when less than 150 ℃, the side reaction occurs when it exceeds 200 ℃ because of the problem of increasing the amount of impurities.

In addition, the isomerization reaction time is 30 minutes to 3 hours, preferably 1.5 to 3 hours. This is because, in less than 1.5 hours, the time is short enough for the isomerization reaction to occur, and in the case of more than 3 hours, a side reaction occurs to increase the amount of impurities. The pressure in the isomerization reaction in the above can be carried out at less than 10bar, preferably at less than 5bar for easy processing and maintenance.

Isomerized 1,4-cyclohexane dimethanol according to another aspect of the present invention may be prepared according to the method described above.

Isomerized 1,4-cyclohexane dimethanol prepared according to the method described above may comprise at least 74% by weight of trans-1,4-cyclohexane dimethanol.

That is, when isomerized 1,4-cyclohexane dimethanol containing at least 74% by weight of trans-1,4-cyclohexane dimethanol prepared according to the preparation method according to the present invention is used as a raw material of the crystalline polymer. The effect of increasing heat resistance can be obtained.

Hereinafter, preferred embodiments of the present invention will be described in detail. However, these Examples are only for illustrating the present invention, and the scope of the present invention will not be construed as being limited by these Examples.

Example  One

200m of 1,4-cyclohexanedimethanol (trans isomer 67%, cis isomer 33%) and 10 g of Ni / NiO-diatomaceous earth catalyst were added to a 500 ml autoclave and isomerized by stirring at 200 ° C. for 3 hours in a nitrogen atmosphere. The reaction was carried out to prepare 1,4-cyclohexanedimethanol containing 74.3 wt% of trans-1,4-cyclohexanedimethanol.

Example  2

1,4-cyclohexanedimethanol was prepared in the same manner as in Example 1 except that 16 g of Ni / NiO-diatomaceous earth catalyst was added. In the prepared 1,4-cyclohexanedimethanol trans-1,4-cyclohexanedimethanol was 76.8% by weight.

Example  3

1,4-cyclohexanedimethanol was prepared in the same manner as in Example 1 except that 40 g of the Ni / NiO-diatomaceous earth catalyst was added. In the prepared 1,4-cyclohexanedimethanol trans-1,4-cyclohexanedimethanol was 80.1% by weight.

Comparative example  1 to 6

200m of 1,4-cyclohexanedimethanol (trans isomer 67%, cis isomer 33%) and the catalyst shown in Table 1 were added to a 500 ml autoclave (Comparative Example 6 without a catalyst), The mixture was stirred at 200 ° C. for 3 hours in a nitrogen atmosphere.

division Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparative Example 6 catalyst CuCr SiO ₂ CuZn Ru / Al ₂ O ₃ Ni / NiO-Diatomite - Catalyst amount (g) 10 10 10 10 4 - Trans isomer (%) 71.2 70.3 69.8 67 72.6 67

As described above, the trans-1,4-cyclohexanedimethanol in the 1,4-cyclohexanedimethanol prepared according to the embodiments of the present invention is 74 wt% or more, using a catalyst containing no nickel, or It was found that the ratio of trans-1,4-cyclohexanedimethanol is small in the case of Comparative Examples which do not use or the range of the catalytic amount is outside the scope of the present invention.

The specific parts of the present invention have been described in detail above, and it is apparent to those skilled in the art that such specific descriptions are merely preferred embodiments, and thus the scope of the present invention is not limited thereto. something to do. Therefore, the substantial scope of the present invention will be defined by the appended claims and their equivalents.

Claims (11)

Hydrogenating 1,4-cyclohexanedicarboxylic acid dialkyl ester to obtain 1,4-cyclohexane dimethanol; And
And isomerizing the 1,4-cyclohexane dimethanol in the presence of a molding catalyst comprising nickel and a support to perform an isomerization reaction. The method for preparing 1,4-cyclohexane dimethanol according to claim 1, wherein nickel in the forming catalyst including nickel and the support is 5 to 75% by weight of the total catalyst. The method of claim 1, wherein the nickel in the forming catalyst including the nickel and the support is in the form of nickel oxide. The method of claim 1, wherein the content of the molding catalyst comprising nickel and the support is 1,4 to 1 to 4% by weight of the total weight of the 1,4-cyclohexane dimethanol and the molding catalyst comprising nickel and the support. A process for preparing cyclohexane dimethanol. The method of claim 1, wherein the support is at least one selected from the group consisting of transition alumina, alkaline earth metals, and rare earths. The method for producing 1,4-cyclohexane dimethanol according to claim 1, wherein the isomerization reaction is carried out under conditions further comprising molybdenum. The method for producing 1,4-cyclohexane dimethanol according to claim 1, wherein the isomerization reaction is performed at 150 ° C to 200 ° C. The method for preparing 1,4-cyclohexane dimethanol according to claim 1, wherein the isomerization reaction is performed for 30 minutes to 3 hours. The method for producing 1,4-cyclohexane dimethanol according to claim 1, wherein the isomerization reaction is performed at a pressure of less than 10 bar. delete delete