CN1608046A

CN1608046A - Process for producing composite mixed ester

Info

Publication number: CN1608046A
Application number: CNA028261569A
Authority: CN
Inventors: 松本哲
Original assignee: Japan Science and Technology Agency
Current assignee: Japan Science and Technology Agency
Priority date: 2001-12-25
Filing date: 2002-06-18
Publication date: 2005-04-20
Anticipated expiration: 2022-06-18
Also published as: JP3907470B2; TW588043B; KR20040058190A; WO2003055842A1; JP2003183372A; CN1285564C; KR100619575B1

Abstract

This invention discloses a process for producing a composite mixed ester suitable for use as a plasticizer having improved nonvolatility as compared with dibasic acid diesters which have excellent general-purpose plasticizer properties and have been used in a large amount but have come to be regarded as endocrine disruptors. The mixed ester is equal to the dibasic acid diesters in production cost and performance even when it contains none of these diesters. Also provided is a composition. Dibasic-acid diesters volatilize according to their vapor pressures, while polymers have nonvolatility and reduced toxicity according to their molecular weights. However, polymers have poor plasticizer performance. Although composite esters having an intermediate molecular weight may meet the requirement, they are difficult to produce and have poor profitability. The process comprises subjecting acids, a diol, and a terminal alcohol to dehydrating esterification and subsequently subjecting the excess alcohol to transesterification. Thus, a composite mixed ester is advantageously produced, which is a composition represented by (R(PX)1-2(AX)n-1AR) and which contains residues of the two dibasic acids bonded in such a manner that one or two residues of one of the acids and one or two residues of the other occur alternately.

Description

Process for producing heterogeneous composite ester

Technical Field

The present invention relates to a method for producing a heterogeneous complex ester. Here, the complex ester is R (AX)_nA compositional formula of AR (n represents a positive number of 1 or more) in which a COMPLEX ESTER (RAXAR) corresponding to n ═ 1 is used as a comparison, and the COMPLEX ESTER is considered as another concept.

Technical Field

In the following description, R and O represent a monohydric alcohol (e.g., octanol), a and P represent dibasic acids (e.g., adipic acid, phthalic acid (phthalic acid)), and X represents a dihydric alcohol (e.g., ethylene glycol and propylene glycol), and the description of the unreacted terminal groups (hydroxyl groups and carboxyl groups) and ester bonds in the ester bond product thereof is omitted.

The complex ester is generally prepared by reacting a monohydric alcohol at the terminal of a dibasic acid of the composition diol, and is prepared as a mixture of compounds having different degrees of polymerization, n being 1 to 7, and the ratio is defined as a proportional decrease in the amount of the compound as the degree of polymerization increases. Regarding the composition, particularly, the distribution of different compositions according to the production method varies, and the composite ester produced by controlling the distribution and the composite ester produced without consideration may be different in composition in consideration of the properties that determine the characteristics of the produced article.

The present invention is an improvement of the previously applied method for producing a different complex ester (Japanese patent application laid-open No. Hei 7-330684), and a method for reducing the distribution range (Japanese patent application laid-open No. 2001-119252) is proposed, and a method for producing a diester of a dibasic acid RAR or RPR by completely preventing the formation of a by-product or making a very small amount of the diester or RPR is proposed, and the ester is produced by the above method, and the ester is produced by using 2 different dibasic acids, adipic acid, HOCOACOOH and phthalic anhydride P (CO)₂O or other succinic anhydrides S (CO)₂O, etc. and establishing the general formula R (PX)_1-2(AX)_0-1A method for producing AR and a heterogeneous complex ester produced by the method.

Regarding the control of the molecular weight distribution of the ester and the formation of the diester, first consider the ester reaction with respect to 3 components (R, A, X):

(1)

(2)

the reaction of (1) 4 moles of the acid a and the monohydric alcohol R with 2 moles of the dihydric alcohol X can produce 2 moles of a product n-1, and if the reaction of (2) is carried out in the same number of moles as (1), 1 mole of a complex ester in which n-2 and 1 mole of a diester can be produced. Since the reactions (1) and (2) proceed simultaneously, RAR corresponding to the number of n can be obtained without fail even if the reaction (1) is the target reaction. The by-produced diester can be obtained only in an amount not corresponding to the target polymerization degree, and conversely, a product having a polymerization degree corresponding to the diester can be obtained. The control of the molecular weight distribution suppresses the formation of diesters, and if the diesters can be eliminated, the desired degree of polymerization can be obtained, and the degree of polydispersity is now controlled to 2 or less, and a process for producing polyesters is applied (Japanese patent application laid-open No. 2001-119252).

This method is problematic in that, similarly to the reaction method, the amount of alcohol used in excess during esterification, and if ROH is used in excess, the esterification reaction proceeds with the transesterification reaction, and RAR is generated by the reaction between the end of the obtained polyester and ROH, so that the desired degree of polymerization cannot be obtained as a result. The present inventors have found that the polymerization degree can be controlled by limiting the amount of ROH used, and that the production of a polyester having a molecular weight distribution of 2 or less is possible by carrying out an esterification reaction in the presence of a complex ester and an ester alcohol.

On the other hand, it is considered that the compound ester has a small n value and thus can reduce the side production of RAR but cannot completely prevent the side production of RAR, and by successfully controlling the reaction molar ratio and carrying out the reaction, particularly by using the above-mentioned activated catalyst, the product having the desired degree of polymerization is produced by a production method which does not use more than the required amount of ROH, and as considered, the side production of RAR can be prevented.

As the amount of excess in the above patent application specified as 0.2 to 2 times the theoretical amount, it was found that the reaction proceeded sufficiently to produce a useful ester even with the use of a relatively low proportion of an activating catalyst (Japanese patent application laid-open No. 2000-147554), and this was related to the utilization of the present invention. As for the prevention of the formation of by-product diesters, the prior art has proposed the formation of a large amount of target low-polymerization-degree esters for the reasons already described, and from the assumption that by-product diesters cannot be completely prevented, a method has been proposed in which a composite ester of different types can be produced by the transesterification method through the following general formula (Japanese patent application laid-open No. 2000-147554).

(3)

That is, in the above reaction formula, phthalic anhydride is reacted with a monohydric alcohol, and then reacted with a dihydric alcohol to produce an ester alcohol of phthalic acid containing a partially complex ester. These ester alcohols are added to an excess amount of adipic acid diester produced in another route to carry out dealcoholization transesterification to obtain a product, and the remaining excess diester PAR is removed by distillation, whereby a heterogeneous composite ester (formula (3)) can be produced. When the amount of RAR in the transesterification reaction is small, the degree of polymerization of the product increases and the viscosity becomes high, and an amount of about 2.5 moles is used for forming an excellent plastic ester, and for example, when the diol component is 1, 2-propanediol, a heterocomplex ester product having an excellent low viscosity of 450 cps and a degree of polymerization of the product of about 1.4 is obtained.

The composition formula obtained by thepreparation method is that the terminal alcohol ROH is octanol OOH recorded as O (PX)_p)_1.4AO, as a component of the aggregate, may be considered to be mixed with R (PXPXPXPXPX) AR and RPXPR produced by this method. The present inventors have also filed a patent for use as a plasticizer, in which the above-mentioned preparation is carried out under the premise that the side production of a diester cannot be prevented by the dehydration esterification reaction of a different complex ester, and although the composition does not meet the object, various different complex esters are prepared and the properties are evaluated to determine the excellent properties (Japanese patent laid-open No. Hei 7-330674). However, since the amount necessary for PAR removal is relatively large, a manufacturing technique for reducing the amount of by-product PAR has been sought.

Since the conventional complex ester contains a high-polymerization composition obtained as a composition having a polymerization degree distribution, particularly, a complex ester of phthalic acid has a high viscosity and the plasticizing efficiency is extremely deteriorated when used as a plasticizer, and a complex ester having a PXAX composition obtained by copolymerizing phthalic acid and adipic acid is studied for the purpose of providing a plasticizer having an excellent low viscosity, and a production method not containing a by-product having a high polymerization degree cannot be established. The use of these as plasticizers and low viscosity processing aids, both of which are excellent, is regarded as an environmental hormone problem, and products containing no plasticizer are being sought. In the production of these complex esters, it is considered that in the production of a composition containing no high molecular oligomer having n-3 or more, the terminal alcohol is efficiently reacted to have a low polymerization composition, and in the esterification, the terminal alcohol is subjected to a secondary transesterification reaction to form a high polymer, and thus the terminal alcohol is reacted with an acid to form an ester. At the time of esterification, when the catalytic function is insufficient, the remaining portion cannot be controlled. In particular, the reaction is known by using an excellent catalyst, and the reaction mode is determined, thereby forming a method for producing an excellent composition.

That is, the present invention is a process for producing a heterogeneous complex ester represented by the formula R (PX)_1-2(AX)_0-1AR (wherein R represents a monohydric alcohol, A and P represent dibasic acids, X represents a dihydric alcohol, and the ester bond is omitted.) is produced by a method comprising: a 1 st step of reacting a 1 st dibasic acid, an excess of a dihydric alcohol and a monohydric alcohol at a reaction temperature of 160 ℃ or lower (in which step the main reaction is preferably carried out to an extent of 1/2 to 2/3); a 2 nd step of reacting a 2 nd dibasic acid and a monohydric alcohol in an equivalent ratio of about 1: 1 (this step is preferably carried out under reduced pressure of 0.2 to 10mmHg for removing excess glycol); a 3 rd step of reacting the products of the steps 1 and 2 (in this step, a diol is used in addition to the reaction molar equivalents, anddehydration esterification with an alcohol in excess of acid, preferably with a sufficiently low acid number); a 4 th step of subjecting the product of the step 3 to transesterification under reduced pressure (the purpose of this step is to cause the ester alcohol remaining in the step 3 in a relatively excessive amount or produced by esterification to react as a main component). The heterogeneous complex ester is produced by subjecting an alcohol component and an acid in excess of the acid to a dehydration esterification reaction to reduce the acid value, and subjecting the ester alcohol produced from the diol component in excess orremaining ester alcohol to a transesterification reaction with a mainly produced ester. The compositional formula of the heterogeneous complex ester indicates the ratio of the components, and does not indicate the arrangement of the components.

Furthermore, the invention refers to the use of the compositional formula R (PX)_1-2(AX)_0-1The heterogeneous complex ester represented by AR (wherein R represents a monohydric alcohol, a and P represent dibasic acids, and X represents a dihydric alcohol, and an ester bond is omitted) has a heterogeneous complex ester having no PXPX structure. In addition, the heterocomplex ester cannot contain RAR, RPR and RAX or contains only trace amounts of RAR, RPR and RAX.

The first dibasic acid is preferably adipic acid, and the second dibasic acid is preferably phthalic acid. The diol is preferably a 2-functional alcohol having 2 to 6 carbon atoms or a polyalkylene glycol having 6 or less carbon atoms, for example, a mixed diol of propylene glycol and 1, 2, 1, 3, 1, 4-butanediol or dipropylene glycol.

Detailed Description

Each step is described with respect to the manufacturing method of the present invention.

The first step is as follows: the first dibasic acid (A, for example, adipic acid) is subjected to a dehydration esterification reaction in the presence of an excess of the diol (X) at a lower temperature than usual (160 ℃ or lower, preferably 140 ℃ C. and 150 ℃ C.), to produce a large amount of AX. Under such conditions, the reaction is allowed to proceed by adding a monohydric alcohol (R) in small amounts. After 2/3-3/4, the reaction was carried out, the catalyst was added, the temperature was raised, and ester dehydration esterification reaction was carried out at 190-210 ℃ to completely reduce the acid value and to obtain a mixed product composed of diol diester (XAX) and ester alcohol (RAX) without diester of 1 st dibasic acid (adipic acid) (RAR). Since the usual pressure reduction is performed in this step, the unreacted diol (X) and monool (R) can be removed.

In this step, R reacts preferentially to X, the amount used determines the composition of the product, and X used in excess is removed under reduced pressure at a low temperature of 0.2 to 20 mmHg. This temperature is determined by the pressure, and the pressure is as low as possible, and it is effective to remove X completely, XAX becomes XAXAXAXAX, and the polymerization degree increases, and it is not preferable that the product is X (AX) under normal conditions_1.05-1.4。

Step 2: in another approach, the anhydride reaction of a 2 nd dibasic acid (P, e.g., phthalic anhydride) and a terminal alcohol (R) is conducted at about 1: 1 to provide the monobasic ester (RP) of the 2 nd dibasic acid (phthalic acid).

Step 3: the reaction is continued by adding the product of the 2 nd step to the reaction system of the 1 st step, or the reaction is continued by adding the product of the 1 st step to the reaction product of the 2 nd step, and the esterification reaction is carried out by the reaction of the monoester (RP) of the 2 nd dibasic acid (phthalic acid) with the ester alcohol (RAX) of the 1 st dibasic acid (adipic acid) and the monovalent diol diester (XAX).

The reaction is carried out in the dehydration esterification reaction in the reaction amounts suitable for the target components of acid and alcohol, the total alcohol equivalent is preferably 5% to 20% more than the acid equivalent, and the alcohol used in excess is incorporated into the reaction system by the transesterification reaction in the next step. The alcohol added in this step to reduce the acid value (method 2 of the specific example of adding a diol) is esterified by reaction with an acid, and instead of substantially no acid, the produced ester alcohol RPX or RAX remains in the esterification product together with an excessively used amount. The dehydration esterification reaction in which the alcohol equivalent is in excess to the acid equivalent can be carried out at an excellent reaction rate particularly in the presence of an activated catalyst at the final stage of the reaction, and the acid is quantitatively reacted. The transesterification reaction in the next step cannot be completely carried out for the ester mixture whose acid value is not sufficiently reduced.

Step 4: further continuing to the step 3, the reaction system is depressurized to allow the main products (RAXPR and RPXAXPR) in the stage 3 and the ester alcohol (RAX and ester alcohol produced by the reaction (RPXAX and additional X) in the stage 3 to remainRPX) can form a product, and RA as a main reaction site is preferentially determined to be obtained. This gives the heterogeneous mixed ester (compositional formula R (PX))_1-2(AX)_0-1AR) which are mostly the major products, transesterificationThe ester alcohol should be present in an excess of the alcohol component, in a smaller amount than the main product. The expected products are RAXAXPR, RPXAXPR, RPX (AX)_0-1AXPR, raspxxar, RPXAXPXAR, RPXPXAXPR, etc. to form products having polymerization degrees of 2 and 3, phthalic acid in the whole molecule containing these products is 1 to 2, and adipic acid likewise has a composition of 1 to 2. In particular, since the compound finally described as a by-product of PXPX structure has a rapid increase in number viscosity according to its formation, and when the ester exchange reaction is carried out, the reaction temperature is higher in the reaction with RP and the RA structure reacts preferentially than in the reaction with RA, the ratio of raspr in the product involved in the reaction is so high that the product has a low viscosity.

The composition is an arbitrary composition produced by changing the composition ratio of phthalic acid and adipic acid, and phthalic acid is inexpensive as compared with adipic acid, and a preferable product is one having as many phthalic acid units in the molecule as possible according to the viscosity.

The method of the present invention can produce a heterogeneous composite ester, and a low viscosity composite ester having a viscosity of about 400-. The linear dibasic acid ester having a large amount of phthalic acid units completely solves the problem of volatility corresponding to the molecular weight of the phthalic acid diester when used as a plasticizer, has a slightly higher viscosity due to its structure, and thus has equivalent plasticity to an improved diester, and adipic acid, which is a linear dibasic acid, is used, and has flexibility and greatly improved water resistance, and it is possible to use phthalic acid, weather resistance, and an excellent plasticizer.

The invention relates to the use of said compounds as plasticizersTo have excellent properties, composed of 4 components of phthalic acid, adipic acid, 2-functional dihydric alcohol and monohydric alcohol, and 2 acids as main components are alternately combined and represented by the general formula R (PX)_1-2(AX)_0-1And a heterocomplex ester represented by AR. That is, after a diol diester of adipic acid and a terminal monool are partially reacted, a diol is added in accordance with the molar amount of the reaction, and the obtained ester alcohol is used, and a reaction with a monool obtained from a dibasic acid anhydride is carried out to prepare a different-type composite ester and an ester alcohol, and the desired different-type composite ester is formed by an ester exchange reaction. By this method, a complex ester is not produced, and the present invention provides a production method which forms an acid diester as a by-product in an extremely small amount and has excellent efficiency.

With respect to the general formula R (PX)_1-2(AX)_0-1AR，R(PX)_1-2AO represents an optionally mixed mixture of RPXAXPA and RPXAO, and is illustrated by way of example (AX)_0-1Preparation of XAX of 100% puritySince the production is practically impossible, the (AX) unit increases correspondingly to the number of the purity polymerization degree calculated as the mixing ratio of axaxaxa. Zero is a completely 100% theoretical value and is the value expressed as an increasing proportion of AX in the ester mixture.

The composition means a composition formed by 1 to 2 phthalic acids and 1 to 2 adipic acids in the molecule as a whole composition containing a very small amount of a high polymer, and the composition is a composition containing almost no PXPXPXPXPXPXPXPXPXPXPXPXPXPXPXPXPX obtained by the production method. Such a composition can also be produced by other methods described in the present patent, particularly by other reaction ratios and methods, and the method is not particularly limited. The use of RPX derived from phthalic acid and terminal esters and diols and the preparation of compounds containing PXPXPXPXPXPX structure but not (PX) by transesterification has been claimed₃The above method of producing a product (Japanese patent application laid-open No. 2000) 147554. Further, the application of the above-mentioned compound ester is directed to the use of R (PX) as a hetero compound ester in the same manner as described in the present application_m(AX)_nA composition (Japanese patent laid-open No. 7-330684) having an AO m of 0.3 or more and an n of 0.3 or less, wherein a mixture having a complex ester completely not containing the (PX) component ratio is evaluated so that the composition having an average total component ratio of 0.3 or more is evaluated to obtain a composition having an AO m of 0.3 or more and an n of0.3 or lessExhibit excellent properties and maintain water resistance. The composition of the present invention is a composite ester composition mainly comprising an alternating polymer, compared with an irregular polymer described by a polymer in the former case, among completely different composite esters which are necessarily contained in 1 or more (PX) as the different composite esters which are likely to fall within the range in view of figures. The method of using RPX, then conducting a dehydration esterification reaction and a transesterification reaction with an excess alcohol component in the same manner as in the present application is not described in detail since the side production of adipic diester cannot be completely prevented, and the production of R (PX) of the present application is described in detail_1-2(AX)_0-1The method for producing AR is also not particularly limited.

Examples

The present invention is illustrated below by examples, which are not intended to limit the present invention. The following example illustrates the use of the terminal alcohol 2-ethylhexanol (octanol, noted under the notation of O or OOH) and the laboratory scale production of O (PX)_p)_1.5The reaction for which AO is an object will be described.

1 mol (146g) of adipic acid and 2.5 mol (190g, 1 mol in excess of the necessary amount) of 1, 2-propanediol (propylene glycol, abbreviated as HOX)_pOH_o) The resulting mixture was charged into a 1L three-port reactor for the dehydration esterification reaction, nitrogen gas was substituted under reduced pressure, and a small amount of 20ml of toluene as an azeotropic solvent was added thereto, followed by heating and stirring at 140 ℃ to 160 ℃ to start the dehydration esterification reaction. 0.5 mol (65g) of 2-ethyl group was added in a small amount on average from 9ml of distilled water to 27ml of distilled waterHexanol continued the esterification reaction, and the esterification reaction was carried out while returning the distilled glycol to the reactor. The propylene glycol was distilled off by azeotropy with water in an amount of 1 molar excess, and the water distilled off by azeotropy was a 30-40% aqueous solution. The addition was completed and 27ml of water was confirmed to be distilled off, and 2 mmol (0.7g of titanium tetrabutoxide) obtained by other route was added and the reaction temperature was raised to 180 ℃ and 190 ℃ to continue the dehydration esterification reaction. The reaction was completed after 1 to 2 hours, and the next reaction step was carried out.

Since the excess propylene glycol is distilled off at 190 ℃, if it can be carried out simultaneously with the measurement of the acid value,by High Performance Liquid Chromatography (HPLC), with determination of the diol component HOX_pAX_pOH, ester alcohol OAX_pSimultaneous determination of HOX for OH purity_pThe residual OH content gives the basis for the calculation of the reaction time in the next step. The target products were 0.5 mole diol diester and 0.5 mole ester alcohol. In this reaction, if octanol is added rapidly at an early stage, diester DOA is by-produced, so that addition of DOA is not by-produced. Further, AX, which is a reactant of adipic acid and a diol, is converted to AXA or AXAX by a stepwise reaction, and therefore it is necessary to carry out the reaction in the presence of an excess of X. In order to achieve such control, it is necessary to lower the temperature to slowly carry out the reaction and to select a temperature of 140 ℃ to 160 ℃. The reaction is a reaction in which adipic acid takes part and takes 2 to 4 hours in the absence of a catalyst. If the temperature exceeds 150 c, propylene glycol should be distilled off as soon as possible due to the azeotropy with water, and the excess amount varies depending on the reaction temperature, and thus, is recycled to the reactor for use while being calculated with the supplement of the distillate fraction. When the excess amount is small and the reaction proceeds rapidly, a diol diester polymer HO (X) is obtained_pA)nX_pThe OH, n value increased to about 1.4 and could be confirmed by HPLC. On the other hand, the value of the degree of polymerization of n can be calculated by calculating the weight of the remaining product by removing the reactant diol under reduced pressure. The theoretical weight of the residual product obtained by concentration under reduced pressure was 289g, and 285g was a product having a composition of 0.5OAXOH and 0.447HO (XA)_1.12Calculated from a mixture of XOH.

Production reaction of OPH (step 2): to 1.5 moles (222g) of phthalic anhydride and 1.5 moles (195g) of 2-ethylhexanol were added 150g of toluene as a diluting solvent, and the mixture was stirred at a temperature of 100 ℃ or lower for 3 hours to effect an acid anhydride reaction. This reaction is an exothermic reaction, the product is monooctylphthalate (abbreviated as OPH), the reaction temperature rises rapidly due to the heat generation during the course of the reaction, and the temperature reaches 140 ℃ or higher depending on the reaction amount in the case of no diluent. Dioctyl phthalate DOP is formed as a by-product of the reaction at such a high temperature, the purity of the phthalic anhydride also affects the reaction, and the anhydride and the phthalic acid remain in the reaction. The remaining acid anhydride causes a decrease in catalytic activity, and particularly in the reaction with a diol, the formation of the phthalic acid diol diester HOXPXOH and the formation of PXPX in the next reaction are considered to cause an increase in viscosity, and it is desired to obtain OPH having a purity as high as possible. The reaction amount of OPH is determined according to the purity of the diol diester andthe ester alcohol.

A2L three-port reactor was charged with 1.30 mol (490g) of OPH reaction solution, 1 mol of the adipic acid reactant was added thereto, and the mixture was stirred to sufficiently dissolve the acid anhydride and the catalyst, followed by addition of 2 to 5 mmol of a catalyst solution. The activated catalyst is prepared by dissolving titanium tetraalkyl in toluene, a small amount of propylene glycol or octanol, and adding a mixed solution of water-soluble dihydric alcohol and water in an amount of 4-20 times the molar amount of titanium to mix and react to obtain the activated catalyst (application 2000-147554). If the dehydration esterification reaction is carried out at 190-210 ℃, the acid value is reduced to 15-25 minutes in one reaction. If the reaction rate is slow and the reaction rate is slow, that is, if the residual diol is removed by increasing the degree of polymerization in the production of the diol diester, the concentration of the whole alcohol is decreased. The OH amount is 0.1 molar excess to the reaction amount in view of theoretical amount, and the reaction proceeds accurately to form an ester mixture of low acid value. The product having a decreased acid value was obtained by closing the reflux opening and gradually depressurizing the inside of the reactor to remove the distillate. Volatile components remaining after the azeotropic addition of toluene and 2-ethylhexanol produced by the transesterification reaction were removed. The transesterification reaction was carried out in accordance with the removal, and the temperature of the final reactor was 210 ℃ and the reduced pressure was 2 to 10mmHg, in which case the reaction was terminated, and the pressure was preferably reduced to 0.2mmHg for the complete reaction including the removal of DOA formed as a by-product, and the amount of the volatile component to be mixed was confirmed by heating and stirring under reduced pressure.

The theoretical amount of octanol produced is based on the amount of diol corresponding to an excess of OH, in this case 0.1 moles, 13g removed, 1.30OPH +0.45HOX (AX)_1.1The OH +0.50 OAXOH reaction is

i)

ii)

The above 2 reactions are envisaged. Therefore, the product is at least a mixture of 5-6 different composite esters, and if the transesterification reaction is completely carried out, the ester alcohol which causes volatile components of the product is completely disappeared.

On the other hand, the esterification reaction of adipic acid can produce DOA as a by-product, and the above reaction conditions prevent DOA from producing as a by-product, and DOP from producing even under the reaction conditions with an acid anhydride having a good purity. However, when octanol is once formed during the transesterification reaction, it reacts with the terminal ester of the product, so that DOP or DOA is secondarily formed, and it is necessary to rapidly remove ROH so that ROH formed by the transesterification reaction cannot react with the product again, and it is necessary to perform the transesterification under reduced pressure. It was found that the transesterification reaction was preferentially carried out by the ester alcohol and the AX or PX site of the ester, and the reaction was more easily carried out by the AX site, and a product having a low viscosity could be produced with respect to the viscosity of the product.

After the reaction product was cooled at 100 ℃, a small amount of a diluent and a small amount of water were added thereto and stirred to hydrolyze titanium, and the residual catalyst was removed by adsorption filtration by adding activated clay. Thereafter, volatile components were removed under reduced pressure to obtain 622g of a product having a viscosity of 420 cps at 21 ℃. If the ester produced had no by-products of DOA and DOP, the moles of reactants were the moles of adipic acid and n is expressed as moles of phthalic acid per mole of adipic acid. Therefore, if the diester is not completely formed, the original reaction product composition is represented by O (PX)_1.3And (AO). Since the number of moles of diester diol was decreased, the molecular weight of 661, the number of moles of 0.95, and O (PX) were calculated by correcting_1.37(AX)_0.05AO has a compositional formula.

The heterogeneous complex ester produced is mainly an alternate complex ester, the bond next to the acid is the structure of PXA in the heterogeneous acid, and particularly the complex ester bond alone of phthalic acid represented by PXP forms a high-viscosity ester having a minimum viscosity of 700 cps, so that the increase in viscosity of the product can be prevented by suppressing the production of PXP as much as possible to form a useful ester. On the other hand, in particular, when a diol diester is produced, OPXOH may be formed as a by-product in a reaction with a residual diol, OPXPX is formed by an ester exchange reaction, and it is preferable that OPXAX is formed when mixed with a complex ester having an OAX terminal, whereby an increase in viscosity can be suppressed. Therefore, the ratio of the glycol ester of adipic acid to the ester alcohol to be used may be set to 1: 1, or from 9: 1 to 1: 9, and the OPH reaction amount in this case may be varied in accordance with the theoretical amount, so that the polymerization degree of the composition (PX) as the product becomes 1 to 2, which is a factor for obtaining the useful low-viscosity product of the present invention.

On the other hand, in (PX)_nThe linear dibasic acid monoester cannot be selectively produced in the product having a polymerization degree of 1 or less, and the diester is by-produced, which necessitates a removal step. Partial replacement of the linear fatty acids by OPH is possible, even with anhydrides as the monobasic esters. By this method, diester of dihydric alcohol to ester alcohol are reacted at a ratio of 1: 9 to produce 0.1HOXAXOHAnd 0.9OAXOH, with 1 mole of OPH

Or The product of the reaction is a mixture of 4-6 products, the composition of which is O (PX)_1.0Products in which AO is close to each other. The actual reaction is such that the addition reaction of the terminal alcohol is strictly carried out in the production of the adipate alcohol, and even then, partial formation of DOA cannot be prevented, the necessity of removing DOA cannot be relaxed, the reaction molar ratio of the product becomes smaller than the theoretical amount, and as a result, the value of n greatly deviates from 1, and the amount of OPH needs to be reduced. The necessity of removing DOA arises, and this becomes a production condition of a product containing a volatile component.

As the 2 nd method, a method of using an excess amount of OPH to be used, adding a diol HOXOH in an excess amount and carrying out a dehydration esterification reaction is employed. By way of example of the above reaction, a 1.6 molar amount of the phthalic acid monoester OPH was prepared using 1.6 moles (237g) of phthalic anhydride and 2-ethylhexanol (208g), and the same method as described above was used to prepare the reaction productAdipate of (2), glycol ester 0.42HO (X) is added_pA)_1.18X_pOH and 0.5 ester alcohol OAX_pA reaction mixture of OH and 1: 1 (polymerization degree by weight) was reacted in a 2L reactor to start a dehydration esterification reaction, 0.16 mol (12.2g) of 1, 2-propanediol was added in an amount corresponding to an excess amount of OPH, and 0.1 mol (7.6 g) of propanediol was additionally used for the reaction in the production of an activated catalyst. That is, 1.7g (5 mmol) of tetrabutoxytitanium was added to and dissolved in 7.6g of propylene glycol, a mixture of 1g of ethylene glycol and 1g of water was added thereto and stirred to produce an activated catalyst, the thus-produced catalyst was added to carry out dehydration esterification at 160-210 ℃ and finally 6.1g of propylene glycol was added in accordance with the decrease in the acid value to carry out esterification, the reaction was carried out at a rate of 15 to 25 minutes as a half-life, and the acid value could be decreased to 0.1 or less after 2 to 3 hours.

Then, the reactor was depressurized to a pressure of 2 to 0.2mmHg to remove volatile components and octanol formed by the ester exchange reaction, thereby confirming the absence of DOA and terminating the reaction. The resultant was cooled to 100 ℃ and a small amount of water and a diluting solvent were added, stirring and active clay was added, the catalyst residue was adsorbed, then, filtration was carried out to remove the catalyst together with the clay, volatile components were removed by heating again under reduced pressure and 675g of the resultant was obtained. The obtained heterogeneous composite ester had a viscosity of 520 cps at 20 ℃ and was a product having a low viscosity, and it was estimated from the conventional experimental procedures that the plasticization efficiency was 50 to 52 relative to DOP50 when used as a polyvinyl chloride plasticizer, and the characteristics as phthalate adipate ester were excellent in water resistance and weather resistance and almost no volatilization reduction amount, and thus the ester could be used as a non-volatile plasticizer, and it was also judged from the results reported previously (Japanese unexamined patent publication No. Hei 7-330684).

The reaction is

1.6OPH+0.42HOX(XA)_1.18OH+0.5OAXOH+0.26HOXOH→

By esterification

0.42OPX(AX)_1.18PO+0.5OPXAO+0.26OPXOH→

Through the next exchange reaction

0.42OPX(AX)_1.18PO +0.24OPXAO +0.26OPXAXPO or

By esterification

0.32OPX(AX)_1.18PO+0.5OPXAO+0.16OPXOH+0.1OP(AX)_1.18OH+0.1OPXPO→

Through the next exchange reaction

0.32OPX(AX)_1.18AXPO+0.24OPXAO+0.16OPXAXPO+0.1OP(AX)_1.18AXPO+0.1

OPXPO

The product having the structure (PXP) can be produced by the next reaction estimated from the above reaction, and the reaction cannot be ignored, so that there is a limit to trying the amount of excess OPH or HOXOH. In the case of the theoretical reaction, 1.6 moles and 1 mole of the reactants are reacted, and the composition of the product is O (PX)_1.5AO having a composition of O (PX) obtained by performing a supplementary correction calculation on the degree of polymerization of a diol_1.73(AX_p)_0.08AO, molecular weight 740, 0.92 mol. The amount of OPH used varies depending on the amount of alcohol added in the production of adipate alcohol, and when OAX is large, the amount of OPH monovalent HOXOH used corresponding to the excess amount of OPX is naturally much larger than the amount of 0.1 mol. However, it is necessary that the viscosity not increase sharply due to the increase of the product of PXPX structure.

Addition of a product of 2: 8 glycol diester and ester alcohol prepared from 1 mole of adipic acid and 0.6 mole of glycol corresponding to 0.6 mole of phthalic acid monoester to produce 1 mole of composite ester and 0.6 mole of ester alcohol, whereby the acid was completely esterified due to dehydration esterification reaction in excess of 0.6 mole of alcohol, followed by transesterification to obtain (O (PX)_1.8AO). Since the target product is OPXAXPO, OPXPXAXPO is partially produced, and the viscosity of the product is slightly high.

(0.2XAX+0.8OAX)+(1.2OPH+0.6OPH)+0.6HOXOH→0.2OPXAXPO+0.8OPXAO+0.6OPX→0.8OPXAXPO+0.2OPXAO

It is necessary to remove PXP containing part and by-products such as DOA or DOP during production, and the composition formula R (PX) of the present invention can be produced by the ester exchange reaction with adipic diester RPX according to the formula (3)_1-2In the case of the heterogeneous complex ester represented by AR, it is necessary to use a large excess amount of diester due to by-product (PXPXPXPXPXPXPXPXPX)The recovery cost of the diester becomes a problem. The present invention has an advantage that diesters are not produced or diesters are produced in a very small amount, and the present invention can be produced by the method described in the next step, but the production of a monobasic ester of adipic acid cannot be strictly performed, and even if the reaction is carried out in accordance with the purpose, the formation of a mixture of a diester and unreacted adipic acid prevents the side production of the diester. A monoalcohol reaction was carried out between adipic acid and a 1-valent alcohol as a terminal alcohol under ordinary conditions at a ratio of 1: 1 to obtain about 1/3 moles of a monoalcohol ester, a monoalcohol diester, and an unreacted acid, respectively, as products. From the above results, there is no specific record of the state of the product, and the target product having a composition formula of R (PX) can be produced by the method of transesterifying an ester alcohol by esterification by-product according to the following formula and the method of the present invention_1-2Complex esters of AR.

Adipic acid of step 1

Phthalic acid of step 2

Phthalate alcohol produced by removing excess alcohol under reduced pressure (0.3mmHg) according to the sequence of the process of formula (3) for the purpose of preventing the formation of R (PXPXPXPXPXPX) OH by the ROH removal of RPXOH, and the dehydration esterification reaction is carried out using the excess 1 component

3.3RPX+A+RAH+RAR→RPXAXPR+RPXAR+RAR+0.3RPX

Followed by transesterification

→RPXAXPR+0.7RPXAR+0.3RPXAXPR+RAR

Producing a mixed composition R (PX) of 2 moles of 1.3RPXAXPR and 0.7RPXAR by the above reaction_1.65A mixture of AR and 1 mole of RAR.

In addition, this reaction may be carried out by first reacting a diol, or by using an excess amount of an alcohol to produce RPX, and in any of these methods, a small amount of PXPX is partially produced, and thus the viscosity of the product becomes slightly high. On the other hand, in the first reaction, in order to prevent the side production of RAR diester, the side production of RAR diester cannot be completely prevented even if the temperature is changed, but the amount of side production of RAR diester can be reduced.

The invention mainly relates to a method for preparing a heterogeneous composite ester with a structure of alternately combining adipic acid and phthalic acid, which mainly relates to a method for preparing the heterogeneous composite esterwith the composition of O (PX)_1-2In the method for producing the AO composition, it is difficult to quantitatively produce the diol diester and the ester alcohol in a place close to the upper and lower limits, particularly in the reaction of adipic acid, and the composition of the product varies depending on the reaction conditions, temperature conditions, and reaction amount, and the volatility of the diol component during production greatly affects the reaction. 1, 2-propanediol is industrially most useful at the lowest cost, and it is easy to control the composition of the product by azeotropic distillation. In contrast, dipropylene glycol and 2-ethyl-1, 3-hexanediol, 1, 6-hexanediol are less volatile and thus easier to control. Considering the volatility of 1, 2-, 1, 3-and 1, 4-butanediol is necessary, it is necessary to use ethylene glycol in as large an excess as propylene glycol. It is also possible to mix and use the diol component according to the purpose of use of the diol component in practical use. The use of the terminal alkyl alcohol is not particularly limited to 2-ethyl-hexanol, and various alcohols and mixed components produced by the oxo process are possible. The method of the present reaction is a method of using phthalic anhydride and effectively using dibasic acid monoester, and other maleic acid, succinic acid, and hydrogenated phthalic acid may be used, or a fatty acid may be partially mixed and used.

When used as a plasticizer, DOA is easily volatilized and can be added as a method for producing a low-viscosity product. DOP volatilizes at 70-80 ℃ for 4 weeks, and almost half of DOP volatilizes in 1 year for films produced by the outdoor method, and is used as a useful plasticizer. It is also used as a processing diluent for a polyester plasticizer. In the case of using as a nonvolatile plasticizer, when the DOA and part of DOP are mixed and used in actual use, the amount of volatilization increases and most of the DOA and part of the DOP remain, and thus the nonvolatile plasticizer can be used, so that even if DOA and DOP are remaining components as trace components, there is no problem in practical use, and a small amount of ROH is used as an excessive component as a manufacturing method, and there is no limitation in the product obtained by strictly controlling the reaction molar ratio. However, if DOA and DOP have not only volatility but also a large influence on biological environment as environmental hormones, the molecular weight of the heterocomplex esters of the present invention is large, and biological activities such as volatility and permeability do not act as a polymer, and it is considered that the heterocomplex esters of the present invention are useful as plasticizers containing no environmental hormones at all by weakening the biological activities, and it is considered that a plasticizer having plasticity, water resistance and weather resistance equivalent to DOP and having excellent non-volatility is produced.

Claims

(modification according to article 19 of the treaty)

1. A process for preparing the composite ester of different types, which is prepared from the component R (PX)_1-2(AX)_0-1AR, wherein in the above formula, R represents a monohydric alcohol, A and P represent dibasic acids, X represents a dihydric alcohol, and ester bonds are omitted, said production method comprising: a 1 st step of reacting the 1 st dibasic acid, an excess of a dihydric alcohol and a monohydric alcohol at a reaction temperature of 160 ℃ or lower; a 2 nd step of reacting the 2 nd dibasic acid and the monohydric alcohol in an equivalent ratio of about 1: 1 in another route; a 3 rd step of reacting the products of the steps 1 and 2; and (4) a step of subjecting the product of the step (3) to transesterification under reduced pressure.

2. The production method according to claim1, wherein the 1 st dibasic acid is adipic acid and the 2 nd dibasic acid is phthalic acid.

3. The production process according to claim 1 or 2, wherein the diol is a 2-functional alcohol having 2 to 6 carbon atoms or a polyalkylene glycol having 6 or less carbon atoms.

4. The production method according to any one of claims 1 to 3, wherein the reaction temperature is 140 ℃ to 150 ℃.

5. The production process according to any one of claims 1 to 4, wherein the 2 nd step is carried out under reduced pressure of 0.2 to 10 mmHg.

6. A heterogeneous composite ester is represented by formula R (PX)_1-2(AX)_0-1AR represents, mainly consists of a compound represented by the formula PAXPR and a compound represented by the formula RPXAXPR, and does not contain PXPX structure, wherein in the above formula, R represents a monohydric alcohol, a and P represent dibasic acids, X represents a dihydric alcohol, and ester bonds are omitted.

Claims

1. A process for preparing the composite ester of different types, which is prepared from the component R (PX)_1-2(AX)_0-1AR, wherein in the above formula, R represents a monohydric alcohol, A and P represent dibasic acids, X represents a dihydric alcohol, and ester bonds are omitted, said production method comprising: a 1 st step of reacting the 1 st dibasic acid, an excess of a dihydric alcohol and a monohydric alcohol at a reaction temperature of 160 ℃ or lower; in another route the 2 nd dibasic acid and monohydric alcohol are present in an equivalent ratio of about 1: 1 step 2 of carrying out a reaction; a 3 rd step of reacting the products of the steps 1 and 2; and (4) a step of subjecting the product of the step (3) to transesterification under reduced pressure.

2. The production method according to claim 1, wherein the 1 st dibasic acid is adipic acid and the 2 nd dibasic acid is phthalic acid.

6. A heterogeneous composite ester is represented by formula R (PX)_1-2(AX)_0-1AR and no PXPXPXPXThe structure, wherein in the above formula, R represents a monohydric alcohol, A and P represent dibasic acids, X represents a dihydric alcohol, and the ester bond is omitted.