WO2003024914A1

WO2003024914A1 - Manufacture of allyl esters of tertiary alkane carboxylic acids

Info

Publication number: WO2003024914A1
Application number: PCT/EP2002/009762
Authority: WO
Inventors: Jean Paul André Marie Joseph Ghislain LANGE; Dennis Humphrey Louis Pello
Original assignee: Resolution Research Nederland B.V.
Priority date: 2001-09-14
Filing date: 2002-08-30
Publication date: 2003-03-27

Abstract

A process for the manufacture of allyl esters from tertiary alkane carboxylic acids, having from 5 up through 15 carbon atoms, and propene, oxygen or an oxygen containing gas, such as air, and water, in the presence of a catalyst system comprising palladium, alkali-metal and copper on an inorganic inert carrier at an absolute pressure in the range of from 0.5 to 20 bar, and at temperatures in the range of from 200 to 300 °C which is, depending on the applied starting carboxylic acid either below or above the atmospheric boiling point of the applied starting carboxylic acid and glycidyl esters derived from said allyl esters.

Description

MANUFACTURE OF ALLYL ESTERS OF TERTIARY ALKANE CARBOXYLIC ACIDS

The invention is relating to a process for the manufacture of allyl esters of alkane carboxylic acids. More in particular the invention is relating to process for the manufacture of allyl esters of alkane carboxylic acids without the involvement of halogen and in particular chlorine.

Allyl esters of alkane carboxylic acids having from 5 to 15 carbon atoms in the acid moiety and more in particular tertiary alkane carboxylic acids, are known as important intermediates for the manufacture of the corresponding glycidyl esters, which are used in a great variety of large industrial scale applications such as the manufacture of coatings, and in particular automotive coatings, in the form of organic solvent based coatings as well as the more modern aqueous lattices . Said glycidyl esters of alkane carboxylic acids were up to now manufactured by means of the reaction of the starting carboxylic acids with epihalohydrine and in particular epichlorohydrine, which in its turn was manufactured via allylchloride, prepared from propene and gaseous chlorine, or alternatively epichlorohydrin is manufactured via allyl alcohol and chlorine. It will be appreciated that on the one hand, the last decade and in particular the last five years, has seen an increasing pressure from national or regional governmental_, regulations and requirements to the chemical process industry, in order to drastically reduce possible chlorine emissions, or even to avoid the use of chlorine completely and on the other hand, in the current manufacturing processes for the chlorination of propene in the gaseous phase to allyl chloride, there is still a need to improve the relatively low yields, and to diminish the high fouling tendency.

Moreover, during the reaction of epichlorohydrine with alkane carboxylic acids or with sodium or potassium salts thereof, it has appeared to be not possible to avoid completely that chlorine originating from epichlorohydrin is intermingled in the final product.

Therefore an object of the present invention is formed by an improved process for the manufacture of glycidyl esters of alkane carboxylic acids, which meets the requirements of present and future environmental legislation and which starts from cheap and generally available basic chemicals .

More in particular an object of the present invention is formed by an improved process for the manufacture of allyl esters of tertiary alkane carboxylic acids, having from 5 up through 15 carbon atoms in the acid moiety.

The preparation of allyl esters of low molecular carboxylic acids such as acetic acid or propionic acid and more preferably acetic acid, comprising the reaction of said acid with propylene and oxygen or an oxygen containing gas, in the gaseous phase, at temperatures in the range from 160 to 300°C and in the presence of a catalyst system, which comprises an alkali metal acetate, a salt of divalent palladium, a copper salt and an aliphatic or aromatic amine, applied on an inert carrier, was known from the German patent application DE3502.548A. Similar processes, also using palladium - copper catalyst on carriers or using palladium, potassium, bismuth and magnesium or a combination of magnesium and barium on carriers, were known from the US patents nos . 4,550,097 and 4,602,104.

More in particular US patent no. 5,011,980 disclosed a process for the preparation of allyl acetate by reacting propylene, acetic acid and oxygen in the gaseous phase at temperatures of from 140 to 260°C in the presence of a catalyst system derived from a palladium salt, as salt of at least one metal selected from copper, lead, ruthenium and rhenium and preferably copper, and an alkali metal acetate which has been impregnated on a carrier and subsequently reduced.

It will be appreciated that with said type catalyst tertiary carboxylic acids having from 5 up through 15 carbon atoms and preferably from 9 up through 13, could not be converted into their allyl esters with propene and air, in the gaseous phase and in an acceptable selectivity. It is known from Sheldon et al . (Organic Reactions, vol. 19, Wiley, 1972, p. 279) that such tertiary carboxylic acids are prone to oxidative decarboxylation at high temperatures in the presence of a redox metal. It will also be appreciated by persons skilled in the art that preparation of allyl esters of tertiary acids is not feasible via trans-esterification reactions .

As result of extensive research and experimentation it has been surprisingly found that tertiary alkane carboxylic acids, having from 5 up through 15 carbon atoms, could be converted with propene, air and water into their allyl esters, at an absolute pressure in the range of from 0.5 to 20 bar, in a temperature range of from 200 to 300°C, and in an attractive selectivity and without any significant leaching of palladium metal from the catalyst system.

Accordingly, the present invention relates to a process for the manufacture of allyl esters from tertiary alkane carboxylic acids, having from 5 up through 15 carbon atoms, and propene, oxygen or an oxygen containing gas, such as air, and water, in the presence of a catalyst system comprising palladium, alkali-metal and copper on an inorganic inert carrier at an absolute pressure in the range of from 0.5 to 20 bar, preferably in the range of from 1 to 5 bar, and at temperatures in the range of from 200 to 300°C which is, depending on the operating pressure and the applied starting carboxylic acid either below or above the actual dew point of the applied starting carboxylic acid.

According to a typical embodiment of the herein before specified process, the tertiary alkane carboxylic acid used have from 9 up to 13 carbon atoms.

According to another typical embodiment of the herein before specified process, the tertiary alkane carboxylic acid used has 5 or 6 carbon atoms.

It will be appreciated that said process is carried out under conditions which, depending on the actual dew point of the applied starting carboxylic acid, can result in liquid phase reactions contrary to the prescribed gaseous phase reactions of the low molecular weight carboxylic acids such as acetic acid, of the prior art processes. Moreover a person skilled in the art expected a significant leaching of in particular palladium metal from the catalyst system in said process when applying carboxylic acids, as starting materials, below their actual dew poin .

According to preferred embodiments of the herein before specified process, the catalyst systems used have been derived from carriers, selected from alumina, silica active carbon, silica-alumina and titanium oxide, while the starting palladium salt has been selected from the group consisting of palladium chloride, palladium sodium chloride, palladium nitrate, palladium acetate, palladium sulfate, while the copper salts have been selected from nitrates, carbonates, sulfates, acetates, citrates, lactates, and while the alkali metal salt is selected from alkali metal hydroxides, silicates, carbonates and bicarbonates .

According to a more preferred embodiment of the herein before specified process catalyst systems are used, wherein, relative to the weight of the carrier, the amount of palladium supported is from 0.1 to 5,0% by weight and preferably from 0,4 to 1,0% by weight, and the amount of copper supported is 0.01-5.0% by weight.

According to more preferred embodiments of the present process, the reaction is carried out in a gas-solid- liquid phase reactor, e.g. in a trickle flow operation applied in an isothermal plug flow reactor, while the molar ratio between propene and the tertiary alkane carboxylic acid is in the range of from 1-100 and more preferably from 5 to 40, the molar ratio between oxygen and tertiary alkane carboxylic acid is in the range of from 0.25 to 10 and preferably from 3 to 5, the molar ratio of water and tertiary carboxylic acid is in the range of from 0 to 100, although the absence of water in the feed is very satisfactory, and the contact time (1/WHSV in hours) is in the range of from 1 to 10 and more in particular from 4 to 6.

Preferred process temperatures are in the range from 225 to 275°C.

It will be appreciated that the allyl esters of the tertiary alkane carboxylic acids can be subsequently converted into their corresponding glycidyl esters by means of epoxidation with a peroxide.

Accordingly, the present invention also relates to a process for the manufacture of glycidyl esters of tertiary alkane carboxylic acids, having from 5 up through 15 carbon atoms in the acid moiety, comprising the initial manufacture of allyl esters, from tertiary alkane carboxylic acids, having from 5 up through 15 carbon atoms in the acid moiety, and propene, oxygen or an oxygen containing gas, such as air, and water, in the presence of a catalyst system comprising palladium, alkali-metal and copper on an inorganic inert carrier at an absolute pressure in the range of from 0.5 to 20 bar, preferably in the range of from 1 to 5 bar, and at temperatures in the range of from 200 to 300°C which is, depending on the operating pressure and the applied starting carboxylic acid either below or above the actual dew point of the applied starting carboxylic acid, followed by subsequent oxidation of these allyl esters into their corresponding glycidyl esters . Oxidation of said allyl esters can be performed by e.g. hydrogen peroxide, hydroperoxides, optionally catalysed by titanium catalysts, organic percarboxylic acids such as peracetic acid, and the like.

Another aspect of the present invention is formed by the glycidyl esters, produced according to said process and which are characterized by a significantly low intermingled chlorine content i.e. certainly less than 100 ppm. , and typically less than 10 ppm. , and by a low content of leached palladium metal, i.e. < 0.5 ppm.

It will be appreciated, that an advantage of the esterification process of the present invention is that the operation below the boiling point of starting carboxylic acids allows the integration of the actual reaction and the separation of formed products by applying reactive distillation or reactive stripping. Accordingly, it is possible to operate fixed bed, or slurry reactors in such a way that the liquid acid is kept or recycled onto the catalyst, while flashing the more volatile allyl ester out of the reactor, together with the unconverted propene and air.

Allyl esters of alkane carboxylic acids having from 5 to 15 carbon atoms in the acid moiety and more in particular tertiary alkane carboxylic acids, can be used as co- monomer that could polymerise with vinylic monomers such as styrene, acrylic or methacrylic esters, aliphatic alkenes or vinyl ester such as vinyl acetate. Those co- polymers could be seen as important intermediates for the manufacture of a great variety of large industrial scale applications such as the manufacture of adhesives, coatings in the form of organic solvent based coatings as well as the more modern aqueous lattices. The invention can be illustrated by the following examples, however without restricting its scope to these embodiments .

Examples

(A) A silica carrier starting material having a density of 0.5 g/ml was used for a 90% Pore Volume (PV) impregnation by dissolving 0.457 g of Na₂PdCl₄ and 0.037 g of CuCl₂ into 23.4 ml of demineralized water, and impregnation of this solution into 25.00 g of carrier material within 15 minutes.

The impregnated carrier material was homogenized on a multi-axel rotating mixer during 15 minutes . Subsequently 0.30 g NaOH were dissolved in 52 ml of demineralized water and the solution was once added to the carrier and the carrier was treated on the multi-axel rotating mixer for 20 hours. Thereafter 2.5 ml of hydrazine (80% by weight in demineralized water) were added and the carrier was treated on the multi-axel rotating mixer for 3 hours .

The impregnated carrier was washed with about 15 liter of demineralized water until all the chlorine had been removed and was dried at 110°C for 4 hours, 2.78 g of potassium acetate were dissolved in 21.7 ml of demineralized water and the solution was impregnated into the carrier material within 15 minutes and homogenized on the multi-axel rotating mixer during 15 minutes. Subsequently, the carrier material was dried (with a hair dryer) under rotation and subsequently dried in an over at 110°C.

(A) blue-white catalyst was obtained, having a (calculated) Pd load of 0.59 wt%, relative to the weight of the carrier.

(B) glass reaction tube, having length of 10 cm and a diameter of 1 cm was loaded with a mixture, obtained by mixing 1 or 2 g batches of the (Pd/Cu) /Si0₂ catalyst, which had been first dried in an oven at 110°C in air during 2 hours, and had been diluted with 5 g of SiC (0.2 mm diameter particles) .

Subsequently the reactor was heated to the desired temperature under air flow.

Two PHARMACIA LKB HPLC 2150 pumps were used to feed the liquids. Oxygen (fed as air) and propylene were fed and controlled by BROOKS 5850 TR mass flow controllers (PHARMACIA and BROOKS are trademarks) .

The propylene gas was introduced followed by air. Then the acid and water pumps were adjusted to the desired flow rate and the reaction was allowed to reach the steady-state for one hour.

The product collecting tube was placed in melting ice/water and the product was condensed at about 0°C. Two layers were obtained: an aqueous bottom layer and an organic top layer with the starting carboxylic acid and the ester product.

The products were analysed with GC on a FFAP column, using anisole as an internal standard.

For the metal content, both liquid phases were analyzed by ICP-AES. Both layers were analyzed for Pd-, Cu- and K-contents .

The results of the experiments, using different tertiary carboxylic acids, namely two VERSATIC acids, having 5 and 10 carbon atoms in the acid moiety, a secondary carboxylic acid, namely ethyl-hexanoic acid, and a primary carboxylic acid, namely n-octanoic acid, and different reaction conditions, have been listed in the Table I-V whereas the Pd, Cu, K leaching in products during the oxidative allylation of VERSATIC acid 10 have been listed in Table VI (VERSATIC is a trademark) .

From the listed data in the Tables it can be clearly, derived that the yield to the corresponding allyl esters are optimal in the temperature range of 200-250°C. Lower temperatures resulted in good selectivity but lower conversion whereas higher temperatures resulted in higher conversion but lower selectivity. It should be noticed that the optimal reaction temperature is clearly below the atmospheric boiling point of all acids exception made for VERSATIC 5. The "missing" products are mainly volatile lower hydrocarbons that result from acid decarboxylation, such as C9 and C7 hydrocarbon if VERSATIC 10 was used as starting carboxylic acid. The "rest liquid" products are those products analyzed by GC which are not carboxylic acids, esters or hydrocarbon products .

It is also very surprising to notice that the tertiary carboxylic acids are converted to the allyl esters at higher yield than do the secondary and primary carboxylic acids .

Moreover element analysis revealed that the leaching of Pd was always below the detection limit of 0.5 ppm whereas the Cu and K leached with increasing amounts as the operation temperature dropped below 200 °C.

Table I

VERSATIC 10

WHSV = 0.2 g/g cat./hr ; p=1 bar C3=/acid = 32.1 mol/mol, O_z/acid = 4.1 mol/mol, H₂0/acid = 11.4 moi/mol Entry Temp. Conversion Yields (mol% i on acid)

(°C) (%) ester hydrocarbon rest liquid missing

1 300 47 8 3 2 34 2 280 42 16 4 1 22 3 260 42 26 2 1 14 4 240 49 38 2 0 9 5 200 20 14 0 0 5 6 150 22 2 0 0 20 7 100 0 0 0 0 0

Table I I

n-Octanoic acid

WHSV = = 0.3 g/g cat./hr ; p=1 bar

C3=/acid = 26.6 mol/mol, O_z/acid = ! 3.4 mol/mol, H₂0/acid = = 9.4 mol/mc

Entry Temp. Convers ion Yields (mol% on acid)

(°C) (%) ester hydrocarbon rest liquid missing

8 300 51 4 1 2 45

9 250 52 6 0 0 45

10 200 23 10 0 0 13

11 150 19 2 0 0 17

12 100 15 0 0 0 15

Tabl e III

Pϊvalic acid

WHSV = 0.2 g/g cat./hr ; p=1 bar C3=/acid = 20.7 mol/mol, 0₂/acid = 2.7 mol/mol, H₂0/acid = 7.3 mol/mol

Entry Temp. Conversion Yields (mol% on acid)

(°C) (%) ester hydrocarbon rest liquid missing

13 300 60 27 0 0 33

14 250 79 66 0 0 12

15 200 26 19 0 1 6

16 150 7 10 0 0 -3

17 100 15 1 0 0 13

Table IV

2-Ethyl- hexanoic acid

WHSV = 0.3 g/g cat./hr ; p=1 bar C3=/acid = 25.1 mol/mol, 0₂/acid = 3.2 mol/mol, H_zO/acid = 8.9 mol/mol Entry Temp. Conversion Yields (mol°/_c i on acid)

(°C) (%) ester hydrocarbon rest liquid missing

18 300 61 2 1 9 49 19 250 32 5 0 2 24 20 200 17 5 0 1 11 21 150 14 1 0 1 12 22 100 57 0 0 1 57 Table V

C 10

!80°C, p=1 bar

WHSV C3=/acid 0,/acid H₂0/acid Convc jrsioi g/g cat./hr mol/mol mol/mol mol/mol (%) ester hydrocarbon rest liquid missing

0.2 15.2 2.0 0 33 12 6 2 14

0.2 69.0 4.1 45.5 36 20 1 2 13

1.1 13.6 0.5 10.0 15 5 1 1 8

Table VI

VERSATIC 10

WHSV = 0.2 g/g cat./hr ; p=1 bar C3=/acid = 32.1 mol/mol, 0₂/acid = 4.1 mol/mol, H_zO/acid = 11.4 mol/mol ntry Temp. Pd Pd Cu Cu K K aq. org. aq. org. aq. org.

(°C) (ppm) (ppm) (ppm) (ppm) (ppm) (ppm)

2 280 3.9 <0.5 <2 n.d. n.d. n.d.

3 260 <2 <0.5 <2 n.d. n.d. n.d.

4 240 <2 0.6 <2 <0.5 n.d. n.d.

5 200 <2 <0.5 <2 8.2 1615 450

6 150 <2 <0.5 <2 13 1285 320

7 100 <2 <0.5 <2 43 3350 100

Claims

C L A I M S

1. Process for the manufacture of allyl esters from tertiary alkane carboxylic acids, having from 5 up through 15 carbon atoms, and propene, oxygen or an oxygen containing gas, such as air, and water, in the presence of a catalyst system comprising palladium, alkali-metal and copper on an inorganic inert carrier at an absolute pressure in the range of from 0.5 to 20 bar, preferably in the range of from 1 to 5 bar, and at temperatures in the range of from 200 to 300°C which is, depending on the applied starting carboxylic acid either below or above the actual dew point of the applied starting carboxylic acid.

2. Process of claim 1 wherein the tertiary alkane carboxylic acids have from 9 up to 13 carbon atoms.

3. Process of claim 1 wherein the tertiary alkane carboxylic acids has 5 carbon atoms .

4. The process of claim 1-3 wherein the catalyst is a catalyst system derived from carriers, selected from alumina, silica active carbon, silica-alumina and titanium oxide, while the starting palladium salt is selected from the group consisting of palladium chloride, palladium sodium chloride, palladium nitrate, palladium acetate, palladium sulfate, while the copper salts is selected from nitrates, carbonates, sulfates, acetates, citrates, lactates, and while the alkali metal salt is selected from alkali metal hydroxides, silicates, carbonates and bicarbonates .

5. Process of claim 1-3 wherein, relative to the weight of the carrier, the amount of palladium supported on the catalyst is, from 0.1 to 5,0% by weight and preferably from 0,4 to 1,0% by weight, and wherein the amount of copper supported is 0.01-5.0% by weight.

6. Process of claim 1 wherein the reaction is carried out in a gas-solid-liquid phase reactor, e.g. in a trickle flow operation applied in an isothermal plug flow reactor, while the molar ratio between propene and the tertiary alkane carboxylic acid is in the range of from 1-100 and more preferably from 5 to 40, the molar ratio between oxygen and tertiary alkane carboxylic acid is in the range of from 0.25 to 10 and preferably from 3 to 5, the molar ratio of water and tertiary carboxylic acid is in the range of from 0 to 100, although the absence of water in the feed is very satisfactory, and the contact time (1/ HSV in hours) is in the range of from 1 to 10 and more in particular from 4 to 6.

7. Process of Claim 1 wherein the temperatures are in the range from 225 to 275°C.

8. Process for the manufacture of glycidyl esters of tertiary alkane carboxylic acids, comprising preparation of allyl esters from tertiary alkane carboxylic acids, having from 5 up through 15 carbon atoms, and propene, oxygen or an oxygen containing gas, such as air, and water, in the presence of a catalyst system comprising palladium, alkali-metal and copper on an inorganic inert carrier at an absolute pressure in the range of from 0.5 to 20 bar, preferably in the range of from 1 to 5 bar, and at temperatures in the range of from 200 to 300°C which is, depending on the applied starting carboxylic acid either below or above the actual dew point of the applied starting carboxylic acid, followed by subsequent oxidation of these allyl esters into their corresponding glycidyl esters .

9. Process of Claim 8 characterized by glycidyl esters having a significantly low intermingled chlorine content i.e. certainly less than 100 ppm., and typically less than 10 ppm. , and by a low content of leached palladium metal, i.e. < 0.5 ppm.

10. Glycidyl esters, obtainable by process according to Claim