KR20040058190A - Process for producing composite mixed ester - Google Patents

Abstract

Although plasticizers have been used in large quantities with excellent properties as general purpose plasticizers, plasticizers having improved economics and performance of equivalent production without improving the volatility of dibasic acid diesters pointed out as environmental hormones are required. The production method of the present invention relates to a method and composition for producing a heterocomplex ester in order to correspond to the object. The dibasic diester volatilizes in response to the vapor pressure, but the polymer has no volatility in response to the molecular weight, and the toxicity is also reduced. However, the performance also worsens as a plasticizer. Although the composite ester which becomes an intermediate molecular weight will correspond, it is difficult to manufacture and it is economically bad. Using an acid, a diol, and a terminal alcohol, followed by a dehydration esterification reaction followed by a transesterification of an excess alcohol, advantageously presenting a method for producing a heterocomplex ester, the preparation method and two dibasic acids, each 1 to 1 Provided are heterocomplex esters of two alternating compositions (R (PX) _1-2 (AX) _0-1 AR).

Description

Process for producing hetero complex ester {PROCESS FOR PRODUCING COMPOSITE MIXED ESTER}

Hereinafter, in the present specification, R and O represent monohydric alcohols (eg, octanol), A and P represent dibasic acids (eg, A is adipic acid, P is phthalic acid), and X is diol. (For example, it is ethylene glycol and propylene glycol.), In this case, description of an ester bond may be abbreviate | omitted in unreacted terminal group (hydrogen group and carboxyl group), and the product to which they were ester-bonded.

Complex esters are generally obtained by the reaction of monohydric alcohols at the diol dibasic acid end of the composition, prepared as a mixture of compounds with different degrees of polymerization of n = 1-7, the proportions of which are proportionally reduced with increasing degree of polymerization. It is prepared as a positive mixing composition. As for the composition, the distribution varies depending on the manufacturing method, and therefore, the complex ester prepared by controlling the distribution should be considered to be a different composition from that produced without consideration. have.

The present invention is particularly a by-product by adopting a method (Japanese Patent Application No. 2001-119252) which has already improved the method for producing a heterologous ester (Japanese Patent Application Laid-open No. Hei 7-330684), which has already been filed, and narrowed its distribution. A method for producing a diester RAR or RPR of dibasic acid is completely prevented or produced for the purpose of producing a trace amount, and the other two kinds of dibasic acids, adipic acid, HOCOACOOH and phthalic anhydride thus prepared are proposed. P (CO) ₂ O or other succinic anhydride S (CO) ₂ by using the O or the like, the composition formula _{R (PX) 1 ~ 2 (} AX) method and heterologous production in this way to create a _{0 ~ 1} AR It relates to a complex ester.

Regarding the control of the molecular weight distribution of the ester and the production of the diester, first consider the ester reaction of the three components (R, A, X):

2 {R + A + X + A + R} → 2 RAXAR (1)

{R + A + X + A + X + A + R} + {R + A + R} → R {AX} ₂ AR + RAR (2)

4 moles of acid A, monoalcohol R, and 2 moles of diol X according to formula (1) result in 2 moles of n = 1 product (1), but in the same mole number of reactions, n = 2, 1 mol and 1 mol diester are produced. Since the reactions of (1) and (2) occur at the same time, even if reacted for the purpose of (1), an amount of RAR corresponding to the number of n is necessarily generated. The by-product diester generates only an amount away from the degree of polymerization of the objective, and conversely, one having a degree of polymerization corresponding to the diester is produced. Therefore, the control of the molecular weight distribution, therefore, if it is possible to suppress and eliminate the production of the diester, it is possible to obtain a product having a desired molecular weight polymerization degree, and has already applied for a method for producing a polyester having a polymerization degree distribution of 2 or less (Japanese Patent) Application 2001-119252.

In the method, the amount of alcohol used excessively in the esterification together with the reaction mode is a problem. When ROH is used in excess, the ester exchange reaction proceeds simultaneously with the esterification reaction. RAR is generated in the reaction of, and as a result, the degree of target polymerization cannot be obtained. The present invention has been made by limiting the amount of ROH used, the polymerization degree can be controlled, and the production of polyester having a molecular weight distribution of 2 or less by causing esterification under the same conditions as the complex ester and ester alcohol coexist. Has become possible.

On the other hand, in the complex ester, although the value of n is small and it is possible to reduce the by-product of RAR, it was thought that it was impossible to prevent it completely. However, by controlling the reaction molar ratio well, the reaction is carried out using the above-mentioned active catalyst, When the product of the desired degree of polymerization was produced according to the manufacturing method which does not use ROH mentioned above, it was thought that the by-product of RAR can be prevented.

In the above patent application, the excess amount is defined as 0.2 to 2 times the theoretical amount. However, even when the active catalyst (Japanese Patent Application No. 2000-147554) is used even at a low ratio, the reaction proceeds sufficiently to produce a useful ester. This also relates to the use of the present invention. Regarding the prevention of by-product diesters, in the prior art, for the reason already described, low-polymerization esters are produced in large quantities to the extent that they are intended, and they cannot be completely eliminated. As a formula, the method which can manufacture a heterogeneous ester by the following method was proposed (Japanese Patent Application 2000-147554).

ROH + P (CO) ₂ 0 → RPH → + HOXOH → RPXOH

2ROH + HOCOACOOH → mRAR → + RPXOH → R (PX) nAR + ROH ↑ + RAR (3)

That is, in the above reaction scheme, phthalic anhydride and monoalcohol are reacted, and then diol is reacted to form an ester alcohol of phthalic acid, which also partially contains a complex ester. It is added to the excess adipic acid diester produced separately, a dealcohol transesterification reaction is carried out to obtain a product, and a heterogeneous ester can be obtained by distilling off the remaining excess diester RAR (formula (3) )). At this time, when the amount of RAR in the transesterification reaction is small, the degree of polymerization of the product is increased and the viscosity is high. When the purpose of the superior plastic ester is about 2.5 mol, for example, the diol component is 1,2-propane. If it is a diol, the heteropolymer product of the low viscosity 450 centipoise of about 1.4 degree of polymerization of the product is prepared.

The component formula from the preparation method is described as O (PX _P ) _1.4 AO if the terminal alcohol ROH is octanol OOH, but as a component of the polymer, incorporation of R (PXPX) AR and RPXPR due to the preparation method can be considered. have. In addition, the inventors of the present invention could not prevent byproducts of the diester in the dehydration esterification reaction in the hetero-complex ester. However, the composition was produced under the premise, so that the composition was different from the purpose, but various kinds of hetero-complex esters were prepared. It was found that they had excellent properties by evaluating their performance, and a patent application for use as a plasticizer was filed (Japanese Patent Laid-Open No. 7-330674). However, since there is still a large amount of RAR removal required, a manufacturing technique for reducing the amount of by-product RAR is required.

Problems to be Solved by the Invention

Since the conventional complex ester is obtained as a composition having a polymerization degree distribution and contains a high polymerization composition, especially in the phthalic acid complex ester, the viscosity is high and the plasticizing efficiency is extremely poor, and when used as a plasticizer, an excellent plasticizer having a low viscosity For this purpose, a complex ester having a PXAX composition corresponding to the copolymerization of phthalic acid and adipic acid has been studied.However, a production method that does not contain a high degree of polymerization by-product is not possible, and in particular, a dibasic acid diester is used as a high degree of polymerization by-product. It is necessary to remove the diester, and there is a deterioration of the product acid value due to thermal decomposition for the removal of the phthalate, and the removal of the adipate causes the manufacturing cost to increase. Above all, although it is used as an excellent plasticizer and a low viscosity additive processing aid, it is a problem as an environmental hormone, and a plasticizer which does not contain it is required. In the preparation of these complex esters, in the preparation of a composition containing no polymer oligomer of n = 3 or more, when the terminal alcohol is efficiently reacted, a low polymerization composition is obtained, but the ester is additionally transesterified by the terminal alcohol in the ester. If this occurs, it becomes a high polymer, and it is conceivable to use terminal alcohol as an ester with an acid. In esterification, when the catalyst function was insufficient, excess control was not possible. The reaction was understood by the use of a particularly good catalyst, the reaction mode was determined, and the method of producing an excellent composition was obtained.

The present invention relates to a method for producing heterocomplex esters. Here, a composite ester is represented by the composition formula of R (AX) nAR (n represents an integer greater than or equal to 1). In this formula, COMPOSITE is compared with COMPLEX ESTER (RAXAR) which is a composite ester corresponding to n = 1. ESTER is thought to be another concept.

That is, the present invention, the first step of reacting the first dibasic acid, excess diol and monohydric alcohol at a reaction temperature of 160 ° C or less (in this step, the main reaction proceeds about 1/2 to 2/3 The second step of reacting the second dibasic acid and the monohydric alcohol at an equivalent ratio of about 1: 1 (this step is preferably performed under reduced pressure of 0.2 to 10 mmHg in order to remove excess diol). ), The third step of reacting the product of the first step and the second step (this step, the dehydration esterification reaction using an excess of alcohol to the acid using an additional diol in accordance with the molar equivalent of the reaction, It is preferable to lower the acid value sufficiently to perform esterification.), And a fourth step of transesterification of the product of the third step (in this step, remaining in the product of the third step corresponding to the excess amount, Consisting of the ester alcohol is produced furnace and an object thereof is that the main component and the reaction), composition formula _{R (PX) 1 ~ 2 (} AX) 0 ~ 1 AR ( wherein R is a monovalent alcohol, A and P are dibasic acids, X is It represents a diol and the description of ester bond is abbreviate | omitted.). This hetero-complex ester causes a dehydration ester reaction between an excess of an alcohol component and an acid to lower the acid value by reducing the acid value, and between the ester alcohol and the main product produced or remaining by a diol component corresponding to the excess amount. It is produced by causing a transesterification reaction at. In addition, the composition formula of the heterocomplex ester indicates the ratio of components, and does not indicate the arrangement of the components.

In addition, this invention is composition formula R (PX) _1-2 (AX) _0-1 AR (In formula, R is monohydric alcohol, A and P are dibasic acids, X represents diol, and description of an ester bond is abbreviate | omitted.) As a hetero complex ester represented by these, it is a hetero complex ester which does not contain a PXPX structure. In addition, the heterocomplex ester may not contain RAR, RPR, and RAX or may contain only a small amount.

Preferably, the first dibasic acid is adipic acid, and the second dibasic acid is phthalic acid. Moreover, it is preferable that the said diol is C2-C6 bifunctional alcohol or C6 or less polyalkylene glycol, For example, a propanediol, 12,13,14-butanediol, and mixed diol of dipropylene glycol.

Embodiment of invention

The manufacturing method of this invention is described in each step.

First step: When the first dibasic acid (A such as adipic acid) is dehydrated in the presence of excess diol (X) at a lower temperature than usual (160 ° C. or less, preferably 140 to 150 ° C.) , AX is generated a lot. Under these conditions, the reaction is proceeded by adding a small amount of monohydric alcohol (R). After the reaction of 2/3 to 3/4 proceeded, a catalyst was added, the temperature was increased, ester dehydration esterification was carried out at 190 to 210 ° C, the acid value was completely lowered, and the first dibasic acid (adipic acid) A mixed product consisting of diol diester (XAX) and ester alcohol (RAX) which does not contain diester (RAR) is obtained. At this stage, since the pressure is usually reduced, unreacted diol (X) or monohydric alcohol (R) is removed.

In this step, R reacts preferentially with X, and the composition of the product is determined according to the amount of use thereof. However, X used in excess is removed at a low temperature and under a reduced pressure of 0.2 to 20 mmHg. The temperature is determined according to the pressure, and the lower the pressure is, the more effective it is. However, when the complete removal of X is attempted, XAX becomes de-XAXAX, and the degree of polymerization is increased. Under normal conditions, the product becomes X (AX) _{1.05 to 1.4} . Not desirable

Second Step: Separately, the second dibasic acid (P, for example phthalic anhydride) and the terminal alcohol (R) are reacted anhydride almost 1: 1 to obtain a monoester (RP) of the second dibasic acid (phthalic acid). .

Step 3: Adding the product of the second stage to the reaction system of the first stage to continue the reaction, or adding the product of the first stage to the reactant of the second stage and continuing the reaction, The esterification reaction by reaction of the monoester (RP) of a carboxylic acid (phthalic acid) and ester alcohol (RAX) and diol diester (XAX) of a 1st dibasic acid (adipic acid) advances.

Although this reaction is a dehydration esterification reaction, acid and alcohol are used as the reaction amount suitable for the desired composition, but the total alcohol equivalent is preferably 0.5 to 20% more than the acid equivalent, and the excess alcohol content is transesterified in the next step. It is blown into the reaction system in the reaction. At this stage, the alcohol added in order to lower the acid value (the second method of a further embodiment of the diol) is substantially esterified in the reaction with the acid, and the ester alcohol RPX or RAX produced instead of the amount used in excess of Likewise remaining in the eserlation product. With respect to the acid equivalent, the dehydration esterification reaction, which is an excess of alcohol equivalent, proceeds at an excellent reaction rate even at the end of the reaction, especially with an active catalyst, and the acid reacts quantitatively. In the ester mixture where the acid value is not low enough, the next transesterification reaction is not extremely advanced.

Step 4: Following the third step, the reaction system is depressurized to obtain the main product of the third step (RAXPR and RPXAXPR) and the ester alcohol remaining in the third step (RAX and the ester alcohol produced in the reaction (RPXAX and X addition). In this case, all of them are combined with RPX)) to produce a product, but the reaction is mainly considered to be the site of RA. In this way, hetero-mixed esters (Formula R (PX) _{1 to 2} (AX) _{0 to 1} AR) are obtained, most of which are main products, but the ester alcohol of the transesterification reaction corresponds to an excess of alcohol content. As a result, the amount is smaller than that of the main product. The products which are expected to be produced are RAXAXPR, RPXAXAXPR, RPX (AX) _{0 to 1} AXPR, RAXPXAR, RPXAXPXAR, RPXPXAXPR and the like. It is prepared as a mixture having a composition of 1 to 2, such as finic acid. In particular, the compounds of the final by-product of the by-product of the PXPX structure rapidly increase in viscosity depending on their production, but in the transesterification reaction, the reaction with RP has a high reaction temperature and the RA structure in contrast to the reaction with RA. Since it reacts preferentially, the more the ratio of RAXPR in the said main product which participates in a reaction, the lower viscosity composition becomes.

Any of these compositions can be produced by changing the composition ratio of phthalic acid and adipic acid. However, phthalic acid is cheaper than adipic acid, and it is desirable to have as many phthalic acid units in the molecule as possible in response to viscosity.

According to the method of the present invention, it is possible to produce hetero-complex esters, but by combining two acids alternately to form hetero-complex esters mainly of PXAX structure, it does not contain a polyester structure having a high degree of polymerization and furthermore, steric hindrance such as phthalic acid It was proved that the viscosity was a low-viscosity complex ester of about 400 to 600 centipoise by producing a very small amount of heterocomplex esters having no or no PXPX structure. In the straight-chain dibasic acid ester with many phthalic acid units, the large volatility corresponding to the molecular weight of the phthalic acid diester at the time of using as a plasticizer is completely solved, although the viscosity is quite high, plasticity performance improves due to a structure, and is equivalent to diester The flexibility of adipic acid of straight-chain dibasic acid was combined, the water resistance was greatly improved, and the weather resistance by phthalic acid was combined, and it was possible to use it as an excellent plasticizer.

The present invention is made of four components of phthalic acid, adipic acid, difunctional diol and monohydric alcohol, which is expected to have excellent performance as a plasticizer, and is mainly formed by alternating two kinds of acids in general formula R (PX) _{1 ~ 2 (} AX ) Relates to a hetero complex ester represented by _{0 to 1} AR. That is, a hetero-complex ester in reaction with a monoester obtained by dibasic acid anhydride, using an ester alcohol prepared by partially reacting a diol diester of adipic acid and a terminal monoalcohol and adding a diol corresponding to the reaction molar amount. And ester alcohol is made and it is set as the desired heterocomplex ester by transesterification reaction. This method provides an efficient production method having a very small amount of acid diester, which is a by-product, which is not possible with complex esters.

General formula R (PX) _1-2 (AX) _{0-1 For} AR, R (PX) _1-2 A0 means arbitrary mixture of RPXAXPA and RPXAO, and (AX) _0-1 are demonstrated in the Example However, since 100% purity production of XAX is practically impossible, it is a number calculated as the mixing ratio of AXAXA corresponding to the degree of purity polymerization, and correspondingly, the unit of (AX) increases. Zero is a fully 100% theoretical value and is a value expressed as an increase in the AX ratio in the ester mixture.

Although this composition contains a very high amount of high polymer, it means the composition which consists of 1 or more of phthalic acid and 2 or more of adipic acid in a molecule | numerator as a whole composition, and is a composition which hardly contains PXPX from the manufacturing method. Such a composition is also possible by the other methods described in this patent, in particular according to the reaction ratio and the method, and the method is not particularly limited. RPX made from phthalic acid and terminal alcohols and diols has previously been filed for obtaining a product containing a PXPX structure in a transesterification reaction but containing no more than (PX) ₃ (Japanese Patent Application 2000-147554). In addition, as a hetero-complex ester, as a substrate of the same type as the present application, a composition having R (PX) m (AX) nAO m = 0.3 or more and n = 0.3 or less is applied (Japanese Patent Laid-Open No. 7-330684), and the composition of the (PX) It is shown that it has the outstanding performance water resistance by evaluating the performance of the composition which averages a total composition ratio 0.3 or more as a mixture with the thing which does not contain at all. The compositions herein are likely to fall in the range from numbers as heterologous esters, but as a complete heterocomplex ester containing at least one with respect to (PX), in contrast to the former being a random polymer described as a polymer, The composition herein relates to a composite ester composition which is predominantly an alternating polymer. By-products of adipic acid esters could not be completely prevented by the method of dehydration esterification followed by the transesterification of excess alcohol in accordance with the same method as using the RPX. (PX) _1-2 (AX) _0-1 The manufacturing method in which AR is manufactured is not specifically limited, either.

EXAMPLES Hereinafter, the present invention will be illustrated by way of examples, but it is not intended to limit the present invention. The reaction at the laboratory scale is described below by way of example for the purpose of producing O (PX _P ) _1.5 AO using 2-ethylhexanol (denoted by octanol, O or OOH) as the terminal alcohol.

1 mole (146 g) of adipic acid and 2.5 mole (190 g, 1 mole excess of required amount) of 1,2-propanediol (propylene glycol, abbreviated as HOX _P OH) were placed in a 1 L three-necked reactor for dehydration ester reaction and Nitrogen substitution was carried out under the following, toluene was added as a small amount of 20 ml of an adjuvant, and it stirred with heat at 140-160 degreeC, and started the dehydration esterification reaction. Between the outflow of 9 ml of water and the outflow of 27 ml of water, 0.5 mole (65 g) of 2-ethylhexanol was added little by little to proceed with the esterification reaction, and the diol flowing out was reacted while flowing back into the reactor. . Since propylene glycol flows out as an azeotrope with water, 1 mole amount is excess and water which flows out at an azeotropy is 30 to 40% of aqueous solution. The addition was complete | finished, and the outflow of 27 ml of water was confirmed, 2 millimoles (0.7 g of tetrabutoxy titanium) of the titanium catalyst separately adjusted were added, the reaction temperature was raised to 180-190 degreeC, and dehydration esterification reaction was continued. After 1 to 2 hours, the reaction was stopped and the reaction of the next step was carried out.

In 190 ℃ so-propanediol is distilled off the excess, if possible, simultaneously with the measurement of the acid value at the same time as the purity of a high-performance liquid chromatography (HPLC), component a diol ester HOX _P AX _P OH, ester alcohol OAX _P OH of HOX _P OH The remaining amount is measured to obtain basic calculation data for the next step reaction. The desired product is 0.5 mole of diol diester and 0.5 mole ester alcohol. In this reaction, since the reaction of the octanol is rapid and rapidly added, the diester DOA is by-produced, so it is necessary to add it to the extent that DOA does not produce. In addition, since AX, which is a reaction product of adipic acid and diol, generates AXA or AXAX in the next reaction, it is necessary to react in the presence of an excess of X. For this control it is necessary to lower the temperature and select a temperature between 140 and 160 ° C. at which the reaction proceeds slowly. This reaction is a 2-4 hour reaction without a catalyst in adipic acid. Propanediol is rapidly distilled off at an azeotropy with water if it exceeds 150 ° C, and the excess is changed according to the reaction temperature. If the amount of over-write down the rapid progress of the reaction, the obtained polymer is a diol diester HO (X _P A) nX _P OH, n value is increased about 1.4, can be confirmed by HPLC. On the other hand, the diol is removed under reduced pressure, and the value of n degree of polymerization can be calculated by calculating from the weight of the remaining product. The theoretical weight of the residual product was approximately 289 g by vacuum concentration, but the approximate product was obtained at 285 g, but the composition was calculated as a mixture of 0.5 OAXOH and 0.447 HO (XA) _1.12 XOH.

Production reaction of OPH (second step reaction): 150 g of toluene was added to 1.5 mole (222 g) of phthalic anhydride and 1.5 mole (195 g) of 2-ethylhexanol as a diluting solvent, followed by stirring at a temperature of 100 ° C. or lower for 3 hours. I was. This reaction is an exothermic reaction, the product of which is monooctylphthalate (abbreviated as OPH). The reaction temperature rises rapidly due to the exothermic heat in the middle, and depending on the amount of the reaction, especially when there is no diluent, it may be up to 140 ° C or more. In the reaction at such a high temperature, dioctylphthalate DOP is by-produced and the purity of phthalic anhydride is affected, but anhydride and phthalic acid remain. Residual anhydrides cause deterioration of catalytic activity, but especially in the reaction with diol, phthalic acid diol diester HOXPXOH is formed, and PXPX is formed in the next step reaction, which can be considered as a cause of viscosity increase. It is desirable to obtain a high OPH. The reaction amount of OPH is determined according to the purity of the diol diester and ester alcohol.

Using 1.30 molar amount (490 g) of OPH reaction solution, it was put in a 2 L three-necked reactor, and 1 mole of adipic acid was added and stirred to make the remaining anhydride and the catalyst pure. Catalyst solution is added. As the activation catalyst, a catalyst which is dissolved by dissolving tetraalkoxy titanium in toluene, a small amount of propanediol or octanol, and adding and reacting a mixture solution of a water-soluble diol having a molar amount of 4 to 20 times the molar amount of titanium with water is activated (Japan Patent Application 2000-147554). When the dehydration esterification reaction is carried out at 190 to 210 ° C, the acid value decreases in the first reaction, and its half life is 15 to 25 minutes. If the rate of decrease of the acid amount is slow and the reaction rate is stagnant, the degree of polymerization is high during the preparation of the diol diester, and the remaining diol is removed to lower the total alcohol concentration. As theoretical amount, OH amount is 0.1 mol excess from reaction amount, reaction advances reliably and it becomes a low acid value ester mixture. The product having a lower acid value closes the reflux opening and gradually depressurizes the inside of the apparatus to remove the effluent. After the addition of the toluene, the remaining volatiles and 2-ethylhexanol produced in the transesterification reaction are removed. The transesterification reaction proceeds in response to this removal, and at the end, the reaction is terminated at a reactor temperature of 210 ° C. and a reduced pressure of 2 to 10 mmHg. However, in order to complete the reaction, the reaction is preferably lowered to 0.2 mmHg including the removal of byproduct DOA. By mixing with heating under reduced pressure conditions, the amount of volatile matter is mixed.

The theoretical amount of the octanol to be produced is an amount corresponding to the excess of OH by diol, in which case it is 0.1 mol and 13 g is removed.

The reaction of 1.30 OPH + 0.45 HOX (AX) _1.1 OH + 0.50 OAXOH

0.35 OPX (AX) _1.1 PO + 0.50 OPXAO + 0.10 OPX (AX) _1.1 OH →

0.35 OPX (AX) _1.1 PO + 0.40 OPXAO + 0.1 OPX (AX) _1.1 AXPO

Ii) 0.45 OPX (AX) _1.1 PO + 0.40 OPXAO + 0.1 OAXOH →

0.45 OPX (AX) _1.1 PO + 0.30 OPXAO + 0.1 OPXAXAO

Two reactions of are expected. Therefore, the product is a mixture of at least 5 to 6 heterologous esters described, and when the transesterification reaction proceeds sufficiently, the ester alcohol which causes the volatilization of the product disappears completely.

On the other hand, according to the esterification reaction of adipic acid, DOA may by-produce, but it can be prevented by said reaction conditions, and DOP can also prevent its production on reaction conditions with high purity anhydride. However, once reacted in the terminal ester of the octanole product produced in the transesterification reaction, it is a byproduct of DOP or DOA. Therefore, it is necessary to quickly remove the ROH obtained in the transesterification reaction so as not to react with the product again. It is necessary to enforce. In this transesterification reaction, it was found that the reaction proceeds preferentially at the site of the ester alcohols and the AX or PX of the ester, and also the reaction at the site of AX is easier, and the viscosity of the product is correspondingly produced as a low viscosity product. It is possible.

After cooling the reaction product to 100 DEG C, a small amount of diluent and a small amount of water are added and stirred, the titanium is hydrolyzed, adsorbed by addition of activated clay and filtered, and the catalyst residue is removed. Thereafter, the volatiles were removed under reduced pressure to obtain 622 g of the product at a viscosity of 420 centipoise at 21 ° C. The esters produced are expressed as moles of adipic acid and n as moles of adipic acid if there are no by-products of DOA and DOP, and n is represented as moles of phthalic acid / moledipic acid. PX) _1.3 AO. Since the number of moles of diol diester is small, the composition formula of O (PX) _1.37 (AX) _0.05 AO, molecular weight 661, and number of moles of 0.95 mol is calculated.

The heterogeneous esters produced are predominantly alternating complex esters, the bonds of which are linked with the acid being the structure of PXA as the heteroacids, especially in the complex ester bonds of phthalic acid alone, represented by PXP, being at least 700 centipoise esters By actively inhibiting, the increase in the viscosity of the product can be suppressed, making it a useful ester. On the other hand, especially in the production of diol diesters, OPXOH may be by-produced in the reaction with the remaining diols, and OPXPX is generated in the transesterification reaction, and therefore it is preferable to mix with a complex ester having an OAX end. It becomes OPXAX and can suppress a raise of a viscosity. Therefore, the ratio of diol ester and ester alcohol of adipic acid to be used was 1: 1, but may be from 9: 1 to 1: 9, and the reaction amount of OPH in that case was used as a composition of the product using a different stoichiometric amount. The degree of polymerization of (PX) 1 to 2 becomes a factor for obtaining a useful low viscosity product of the present invention.

On the other hand, in the degree of polymerization of (PX) n, the monoester of linear dibasic acid cannot be selectively produced in a product of 1 or less, diesters are by-produced, and a removal step is required. Although OPH can partially replace linear fatty acids, it becomes possible to use it as a monoester even if anhydride is used. In this way, diol diester and ester alcohol 1: 9 were prepared for the purpose of 0.1 HOXAXOH and 0.9 OAXOH, and the reaction with 1 mole of OPH

0.1 OPXAXPO + 0.8 OPXAO + 0.1 OAXOH →

0.1 OPXAXPO + 0.7 OPXAO + 0.1 OPXAXAO or,

0.1 OPXAXOH + 0.9 OPXAO → 0.1 OPXAXAXPO + 0.8 OPXAO

The product of this reaction is a mixture of products of 4-6, the composition of which is close to 0 (PX) _1.0 AO. In the actual reaction, in the production of adipic acid ester alcohol, even if the addition reaction of the terminal alcohol is strictly prevented, partial production of DOA cannot be prevented, and the removal is not necessary, and the number of moles of the reaction of the product is higher than the theoretical amount. As a result, the value of n is increased to greater than 1, so that the amount of OPH reaction needs to be reduced. DOA needs to be removed, which is a condition for the preparation of products containing volatiles.

As a 2nd method, the method of using the OPH usage-amount used excessively, adding the diol HOXOH corresponding to an excess amount, and performing a dehydration esterification reaction is employ | adopted. Illustrating according to the above reaction, 1.6 mole of phthalic anhydride OPH was prepared using 1.6 mole (237 g) of phthalic anhydride and 2-ethylhexanol (208 g), and the adipic acid ester prepared in the above manner was used. A 1: 1 mixed reaction solution of diol ester 0.424 HO (X _P A) with _1.18 X _P OH and 0.5 ester alcohol OAX _P OH was added (degree of polymerization according to the gravimetric method) to start the dehydration esterification reaction in a 2 L reactor. In addition, 0.16 mol (12.2 g) of 1,2-propanediol was added as an amount corresponding to the excess of OPH, but 0.1 mol 7.6 g of propanediol was further reacted with the production of the activation catalyst. That is, 1.7 g (5 mmol) of tetrabutoxy titanium was added to 7.6 g to dissolve it, and a mixed solution of 1 g of ethylene glycol and 1 g of water was added and stirred, followed by addition of an activated catalyst to produce dehydration esterification at 160 to 210 ° C. After the addition of 6.1 g of propanediol in the last time in accordance with the lowering of the acid value, and esterification, the reaction proceeds at a half-life rate of 15 to 25 minutes and the acid value can be 0.1 or less after 2 to 3 hours.

Subsequently, the reactor was depressurized to finally reach 2 to 0.2 mmHg, the volatiles were removed, and the octanol produced in the transesterification reaction was removed, and the reaction was terminated by confirming that there was no DOA. The product was cooled at 100 ° C, stirred with a small amount of water and a diluent, and then activated clay was adsorbed to adsorb the catalyst residue, filtered to remove the catalyst together with the clay, and the volatiles were further removed by heating under reduced pressure to give 675 g of the product. The viscosity of the resulting heterocomplex ester is estimated to be 50 to 52 as compared to its plasticization efficiency DOP50 when used as a plasticizer of polyvinyl chloride as a low-viscosity product of 520 centipoise at 20 ° C. The phthalate adipate has excellent water resistance and weather resistance, and can be used as a nonvolatile plasticizer with little volatile loss. It is also judged from the results previously reported (Japanese Patent Laid-Open No. 7-330684).

This reaction

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

As esterification

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

As the next exchange reaction

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

As esterification

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

+ 0.1 OPXPO →

As the next exchange reaction

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

+ 0.1 OPXPO

In the following reactions estimated according to the above, a product having a structure of (PXP) is produced, and the reaction cannot be ignored, and the amount of application of excess OPH or HOXOH is limited. When theoretically reacted, the product is a reaction of 1.6 moles and 1 mole, the composition of which is O (PX) _1.5 AO, but from the diol polymerization degree correction, the composition is 0 (PX) _1.73 (AX _P ) _0.08 AO, molecular weight 740, 0.92 mol. The amount of OPH used depends on the amount of alcohol added during the production of adipic acid ester alcohol, and when OAX is large, the amount of OPH and HOXOH corresponding to the excess of OPX is naturally larger than 0.1 molar. However, it is necessary to increase the product of the PXPX structure so that the viscosity does not increase rapidly.

When 1 mole of complex ester and 0.6 mole of ester alcohol are added by adding a product of diol diester and ester alcohol 2: 8 made from 1 mole adipic acid and 0.6 mole of diol corresponding to 1.8 mole phthalate monoester, dehydration esterification is performed. The reaction is in excess of 0.6 molar amount of alcohol, so that the acid is fully esterified, followed by transesterification (O (PX) _1.8 AO). The desired product becomes OPXAXPO, but partly OPXPXAXPO, so the viscosity of the product is quite high.

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

0.2 OPXAXPO + 0.8 OPXAO + 0.6 OPX → 0.8 OPXAXPO + 0.2 OPXAO

Heterocomplex esters represented by the composition formula R (PX) _1-2 AR of the present invention, which require partial removal of by-products such as DOA or DOP at the time of PXP or manufacturing, are adipine according to the formula (3) described. It is possible to make the acid diester by transesterification with RPX, and in this case (PXPX) is a by-product, it is necessary to use a lot of excess diester, but the recovery cost becomes a problem. Although the present invention is not capable of diesters, there are features that can be made in a very small amount. The production of monoesters of adipic acid can be carried out strictly, although it is also produced by the method described below using the method of the present invention. And even by the desired reaction, it becomes a mixture of diester and unreacted adipic acid, so that byproducts of the diester cannot be prevented. In the reaction of adipic acid of 1: 1 and monohydric alcohol which becomes a terminal alcohol in normal conditions, a product is about 1/3 mol of monoester, diester, and unreacted acid. From the above results, although there is no specific condition for the product, the compound of the formula R (PX) _{1 to 2} AR as the desired product is subjected to the transesterification reaction of the ester alcohol which is esterified by the method of the present invention according to the following equation. Esters can be prepared.

About the first stage adipic acid

3 HOCO (CH ₂ ) ₄ COOH + 3 ROH → HOCOACOOH (abbreviated as A) + RAH + RAR

About the Second Stage Phthalic Acid

P (CO) ₂ O + ROH → RPH

RPH + HOXOH → RPXOH (or RPX)

(3) Dehydration ester using phthalate ester alcohol obtained by excess alcohol removal under reduced pressure (0.3 mmHg) for the purpose of preventing the formation of R (PXPX) OH according to the deROH of RPXOH according to the formula If you react

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

Then transesterification,

→ RPXAXPR + 0.7 RPXAR + 0.3 RPXAXPR + RAR

The above reaction produces a mixture of 1.3 RPXAXPR and 0.7 RPXAR of R (PX) _1.65 AR 2 moles and 1 mole RAR.

In addition, this reaction may react with a diol first, and may produce RPX using excess alcohol, and since any method produces partial trace amount of PXPX, the viscosity of a product will become quite high. On the other hand, when the temperature is changed in order to suppress the by-product of the RAR diester in the first step reaction, it is impossible to completely prevent the by-product of the RAR diester, but it is possible to reduce the by-product amount of the RAR diester.

The present invention mainly relates to a method for producing a heterologous ester having a structure in which adipic acid and phthalic acid are alternately bonded. The composition is mainly a method for producing a composition having O (PX) _{1 to 2} AO, but in the vicinity of the upper and lower limits, In the reaction of adipic acid, it is difficult to quantitatively prepare diol diesters and ester alcohols, so that the product composition varies depending on the reaction conditions, temperature conditions and reaction amounts, and the volatility of the diol component during production is greatly influenced. . 1,2-propanediol is the most industrially inexpensive and useful, but azeotropically distilled and difficult to control the composition of the product. In contrast, dipropylene glycol, 2-ethyl-1,3-hexanediol, and 1,6-hexanediol have low volatility and are easy. 1,2-, 1,3-, and 1,4-butanediol need to consider volatility, and ethylene glycol requires a lot of excess use such as propanediol. The diol component can also be mixed and used in actuality according to the purpose of use. The use of the terminal alkyl alcohol is not particularly limited to 2-ethylhexanol, and various alcohols and mixed compositions prepared by the oxo method may be used. The method of this reaction is a method which effectively used the dibasic acid monoester using phthalic anhydride, can also be implemented with respect to other maleic acid, succinic acid, and hydrophthalic acid, and there exists a possibility to mix and use a fatty acid partially.

In using a plasticizer, DOA volatilizes easily, but it adds and uses as a low viscosity specification. In addition, DOP volatilizes for 4 weeks at 70 to 80 ° C, and volatilizes about half a year as an outdoor specification film, but it has been used as a useful plasticizer. It may be used also as a diluent for processing a polyester plasticizer. Partial mixing of DOA and DOP when used as a nonvolatile plasticizer increases the amount of volatile loss in actual use, but most of them remain and can be used as a nonvolatile plasticizer. Since there is no problem in practical use, it is not limited to the product obtained by using a small amount of ROH together as an excess content and controlling reaction molar ratio strictly. However, when DOA and DOP are not only volatile but also have a great influence on the biological environment as an environmental hormone, the heterocomplex esters of the present invention have a high molecular weight, and thus bioactivity such as volatility and permeability is high in molecular weight, and thus does not have any action. It is considered to be weak and is useful as a plasticizer that does not contain any environmental hormones, and is considered to be an excellent nonvolatile plasticizer having plasticizer equivalent to DOP, water resistance and weather resistance.

Claims (6)

A first step of reacting the first dibasic acid, excess diol and monohydric alcohol at a reaction temperature of 160 ° C. or lower, and a second step of separately reacting the second dibasic acid and monohydric alcohol in a molar ratio of about 1: 1. A compositional formula R (PX) _{1 to 2} (AX) _{0 to 1} AR, comprising a third step of reacting the first step with the product of the second step and a fourth step of transesterifying the product of the third step under reduced pressure. (Wherein R represents a monohydric alcohol, A and P represent a dibasic acid, X represents a diol, and descriptions of ester bonds are omitted). The method of claim 1, wherein the first dibasic acid is adipic acid and the second dibasic acid is phthalic acid. The method for producing a heterogeneous complex ester according to claim 1 or 2, wherein the diol is a C 2-6 difunctional alcohol or a C 6 or less polyalkylene glycol. The method for producing a heterogeneous complex ester according to any one of claims 1 to 3, wherein the reaction temperature is 140 to 150 ° C. The method for producing a heterogeneous complex ester according to any one of claims 1 to 4, wherein the second step is performed under a reduced pressure of 0.2 to 10 mmHg. Heterogeneous represented by the formula R (PX) _1-2 (AX) _0-1 AR (wherein R represents a monohydric alcohol, A and P represent a dibasic acid, X represents a diol, and descriptions of ester bonds are omitted.) Complex esters, wherein the complex compound does not contain a PXPX structure.