Title of Invention

MANUFACTURING PROCESS FOR THE PREPARATION OF α, α-BRANCHED ALKANE CARBOXYLIC ACIDS

Abstract

The present invention relates to a manufacturing process for the preparation of a, a- branched alkane carboxylic acids, by reacting a mono-olefin consisting of a dimmer (C<sub>8</sub>) or trimer (C<sub>12</sub>) of n-butene comprising predominantly 2-butene, with carbon monoxide in the presence of a strong acid catalyst characterized in that the starting n-butene dimer or n-butene dimer olefm feed has not been fractioned and that the acid catalyst ,is composed of BF<sub>3</sub>/H<sub>3</sub>PO<sub>4</sub> in a molar ratio of BF<sub>3</sub>/H<sub>3</sub>PO<sub>4</sub> in the range of from 0.5:1.0 to 5.0:1.0, or ofCF<sub>3</sub>SO<sub>3</sub>H, that the weight ratio of the catalyst relative to the mono-olefm is in the range of from 1: 1 to 10: 1, that the reaction is carried out at a temperature in the range of from 60 to 140°C, and with an initial water content in the catalyst system in the range of from 8 to 25 wt%.

Full Text

The present invention relates to a manufacturing process for the preparation of a,ct-branched alkane carboxylic acids providing esters with an improved softness. More in particular the invention relates to the preparation of aliphatic tertiary saturated carboxylic acids or a, cc-branched alkane carboxylic acids, which contain 9 or 13 carbon atoms and which provide eaters with an improved softness. It is generally known from e.g. US 2,831,877, US 2,876,241, US 3,053,869, US 2,967,873 and US 3,061,621 that mixtures of From e.g. H van Hoorn and G C Vegter, Dynamic modulus measurements as a tool in the development of paint base materials FATIPEC, Euro Continental Congress 9, Pleniere p. 51-60 (1968); Rheol, Acta 10, p. 208-212 (1971); H van Hoorn, the influence of side group structure on the glass transition temperature of isomeric vinyl ester polymers, the relation between the final coating film properties and the isomer distribution in starting branched carboxylic acids, was known. In such mixtures of a,a-branched alkane carboxylic acids, significant proportions of blocking 6-methyl- branched carboxyiic acid isomers were found, the properties of which have been found to antagonize the attractive properties of other a, ex-branched saturated carboxyiic acid constituents of said mixtures, when applied in the form of derivatives such as glycidyl esters or vinyl esters in the coating industry, requiring more and more so-called softer acid derivatives. More in particular the conventionally produced a,a-branched carboxyiic acid mixtures had been found to cause a too high hardness of the final coating of films, which was disadvantageous and therefore undesired for certain applications, due to the presence of significant proportions of blocking (J-alkyl-branched isomers. One of the more recent remedies has been disclosed in EP 1033360A1. The problem of providing better softening derivatives of a,ct-branched acids, manufactured from alkenes, carbon monoxide and water and an acid catalyst was solved therein by a process, which actually comprised: (a) oligomerisation of n-butene, comprising predominantly 2-butene; (b) separation of butene dimers and/or trimers from the oligomerisate; (c) conversion of the butene dimers and/or trimers into carboxyiic acids; (d) conversion of the carboxyiic acids into the corresponding vinyl esters showing attractive softening properties when mixed into other polymers or if used as comonomers in coatings. These attractive properties were shown only to be reached by application of a specifically selected wOCTOL" oligomerisation process, as known from e.g. Hydrocarbon Processes Int. fid. (1966), 65 (2, sect.l), pages 31-33, whereas said attractive properties of the final vinyl esters could not be reached by prior art alternatives, i.e. oligomerisation processes using acid Montmorillonite catalyst or a DIMERSOL process, known from e.g. Cornils, Hermann, Applied Homogeneous Catalysis with Organoiaettalic Compounds, p261-263, Verlsg Chemie 1996. Said OCTOL process uses a so called Raffinate III fraction, which was rich of 2-butene, and the obtained specific dimers or trlmers were subsequently converted into carboxylic acids by means of a process using as catalyst a strong acid such as sulfonic acids or a complex of boron fluoride, and water: and Cu+ ions as co-catalyst and temperatures in the range of from 20 to 35 °C and a CO pressure of at least 30 bar. With the term "predominantly comprising 2-butene" as used throughout the present specification is meant that the starting n-butene feed comprises at least 70 wt% of 2-butene and preferably at least 85 wt%. More in particular, it was known from said EP 1033360A1 that vinyl esters with significantly improved softening properties could be reached depending on the branching degree in the starting olefin, to be used for the manufacture of a,cc-branched carboxylic acids. This disclosure taught that the Tg of the homopolymer of vinyl esters of carboxylic acids derived from a n-butene feed predominantly comprising 2-butene feed, by acid catalysed (Montmorillonite) oligomerisation of butene is +38°C and is therefore a "hard" comonomer. The Tg of the homopolymer of the vinyl ester of carboxylic acids derived from a dibutene obtained by the DIMERSOL oligomerisation process of a n-butene, predominantly comprising 2-butene, is considerably lower, i.e. +1°C. The object of the process of EP 1 033 360 Al were branched carboxylic acids, which were prepared from butene dimers, obtainable by the OCTOL oligomerisation process from a n-butene starting material, predominantly comprising 2~butene and containing not more than 35 wt% of mult!-branched olefins, such as diraethylhexene, and preferably at most 25 wtft. Moreover said carboxylic acids, having a significantly increased content of 2,2-dimethyl heptanoic acid and 2-ethyl,2-methyl hexanoic acid, and a decreased content of 2,3-dimethyl-2-ethyl pentanoic acid, could provide the presently required attractive properties of the corresponding vinyl esters, such as a Tg of -3°C at the lowest for the homopolymer of said Cg vinyl ester. Another object of the disclosed process in said EP 1 033 360 Al were branched Cu carboxylic acids, which were prepared from butene trimers obtainable by the OCTOL oligomerisation process. Moreover said carboxylic acids, could only provide the presently required attractive properties of the corresponding vinyl esters, such as a Tg of -13°C at the lowest for the homopolymer of said C13 vinyl ester. A further improved embodiment could be reached by application of a process disclosed in EP 1 029 839 A disclosing a process for fractionation of the dibutene mixtures from the OCTOL process, i.e. mixtures of Ca olefins, in order to obtain branched carboxylic acids of which the homopolymer of the corresponding vinyl C9 esters show a still lower Tg, i.e. -12"C. In said publication there is not any teaching to a skilled person as to the effects of fractionation of tributene oligomers, in order to reach softer branched. C13 alkane carboxylic acids It will be appreciated that said disclosures taught to a person skilled in the art that vinyl esters of o,a-branched c9 alfcane carboxylic acids, having homopolymers with a Tg as low as -12°C, could only be obtained by a process comprising oligomerisation of n-butene predominantly comprising 2-butene, by means of the OCTOL process, followed by diatIllative fractionation of the oligomer mixture, conversion of the bottom fraction into a,a-branched alJcane carboxylic acids, and subsequently conversion to the corresponding vinyl ester, which will increase the coat price per unit as compared with conventional processes. It will be appreciated that there is a still growing need for aliphatic tertiary saturated carboxylic acids, which gives rise to softer coating films, formed from their derivatives, such as glycidyl esters or vinyl esters, and which will be further referred to as "soft a, a-branched alkane carboxylic acids" and which can be simultaneously be manufactured without additional fractionation of the olefin feed and therefore at lower manufacturing costs. An object of the present invention is to provide such soft a,a-branched alkane carboxylic acids in order to attain more attractive properties of coatings derived therefrom. With the term *soft a,a-branched alkane carboxylic acids", as used throughout the gpecification, are meant those acids of which the homopolymer of the corresponding vinyl esters show a Tg of -3°C or lower in the case of C9 acids and a 1g of -13°C or lower in the case of C13 acids. As a result of extensive research and experimentation a process giving the branched carboxylic acids aimed at, has surprisingly been found. Accordingly, the invention relates to a manufacturing process for the preparation of a,a-branched alkane carboxylic acids, the vinyl esters of which can provide homopolymers with a Tg of -3°C or lower in case of C9 acids and a Tg of -13°c or lower in case of C13 acids, by reacting a mono-olefin or a precursor thereof, with carbon monoxide in the presence of a strong acid catalyst characterized in that the starting olefin is a dimer or trimer derived from n-butene, comprising predominantly 2-butene, that the acid catalyst is composed of BF3/H3PO4 in a molar ratio of BF3:H3PC>4 in the range of from 0.5:1.0 to 5.0:1.0, or of CF3S03H, that the weight ratio of the catalyst relative to the mono-olefin is in the range of from lsl to 10:1, that the reaction is carried out at a temperature in the range of from 60 to 140 "C, and with an initial water content in the catalyst system in the range of from 8 to 25 wt%. According to a more preferred embodiment, using a BF3/H3PO4 catalyst, the molar ratio between BF3 and H3PO4 is in the range of from 1:1 to 3:1 and the carbon monoxide pressure is in the range of from 20 to 100 bar. Preferably the reaction temperature is in the range of from 80 to 140 *C and the carbon monoxide pressure is in the range of from 30 to 90 bar. The preferred initial water content in the catalyst system is in the range from 6 to 25 wt%. Wore preferably the preferred initial water content is in the range of from 12 to 25 wt%. Preferably the weight ratio of the catalyst relative to the mono-olefin is in the range of from 2:1 to 6:1. The starting mono-olefin is a mixture of oligomers of butene. It will be appreciated that the starting mono-olefins actually consist of several olefin isomers in varying proportions. It will also be appreciated that the water content of the reaction mixture changes throughout the reaction since 1 mole of water is reacted on every mole of mono-olefin fed. Usual reaction times of the present process are within the range of from 15 to 120 minutes. Preferred reaction times are within the range of from 20 to 90 minutes. More preferred reaction times are within the range of from 30 to 60 minutes. It will be appreciated that the process of the present invention can be carried out as batch process, semi-batch and preferably as continuous process and that the starting olefins can be formed in situ from precursors. Precursors for olefins which can be suitably used are e.g. alcohols, esters, or carboxylic acids. It will be appreciated that in case of application of e.g. an alcohol precursor for an olefin, the co-produced water forms a part of the total water amount as specified hereinbefore. It will also be appreciated that the continuous process can be carried out as described by e.g. US 3,068,256 and in "New Syntheses with Carbon Monoxide" J. Falbe, New York 1980, pages 406-408 and references cited therein. The acid mixtures initially obtained can be purified by methods known per se, such as distillation. It will be appreciated that the "softer" a,a-branched saturated carboxylic acids can be converted by known methods in their derivatives such as salts, eaters, acid halides and more in particular glycidyl esters or vinyl esters, which can be used as attractive starting inaterials in the coating industry. It has been surprisingly found that mixtures of a,cc-branched alkane carboxylic acids, comprising higher proportions of soft isomers, could be prepared in a reproducible, preferably continuous way and starting from relatively cheap feedstock, preferably butene dimers or trimera derived from n-butene, predominantly comprising 2-butene. It will be appreciated that, according to the process of the present invention, a,a-branched alkane carboxylic acids can be prepared of which the horaopolymers of the corresponding vinyl esters have a Tg lower than -3"C in the case of Cs acids and lower than -13°C in the case of Ci3 acids, and said a,ct~branched alkane carboxylic acids can be obtained from butene dimer CB or butene trisier Cia olefins, using the "D1MERSOL" process or the "Montmorillonite catalyst"(OCTOL) process as oligomerisation process and without further fractionation of the butene dinver or butene triiaer olefin feed, which will be regarded as very surprising to people skilled in the art. Another aspect of the present invention is formed by the a,a~branched alkane carboxylic acids, obtainable by the hereinbefore defined process. Still another aspect of the present invention is formed by esters, such as vinyl or glycidyl esters of said carboxylic acids e.g. by conversion of them with acetylene, e.g. as known from. WO 96/16494, EP0512656B1 or EP0729448B1, or with epichlorohydrin, e.g. as known from WO/OO/17179 (PCT/EP99/07393), in the presence of a suitable catalyst. The invention is further illustrated by the following examples, however without restricting its scope to these embodiments. Examples Example 1 A 250 ml Hastelloy C autoclave is continuously fed with 5.8 g/minute of a catalyst system, which consists of BF3/H3PO4/water in a BF3/R3PO4 molar ratio 1.5/1 and 1.1 g/minute butene trimer {BT3) obtained by the DIMERSOL type process. The water content of the catalyst system is set to 13.0 wt%. The autoclave is equipped with a manometer, a mechanically driven stirrer, a heating mantel, inlets for CO, olefins, fresh catalyst {for start-up), catalyst recycle stream, and a dip-tube for the continuous withdrawing of the product/catalyst mixture. The water recycle is returned to the reaction mixture just before the settling vessel. The temperature in the autoclave is 112°C and the carbon monoxide pressure of 80 bar is regulated via a back-pressure. Subsequently the reaction ruiKture is separated in a settling vessel. The lower catalyst rich layer is recycled to the reactor and the upper organic layer is continuously washed, in a packed column, in counter current with water. The water layer from the washing column is recycled to the reactor outlet and the fresh water flow to the column is set a such a rate that the water concentration in the settling vessel maintains at a constant level. The organic layer contains the crude carboxylic acid mixture. The organic layer contains the crude carboxylic acid mixture in a yield of 89 wt% as determined by Gas Chromatography. After removal of the light ends and heavy ends from the organic layer by distillation, the "soft" o,a-branched C13 alkane carboxylic acid mixture is obtained. Example 2 The mixture of a,a-branched alkane carboxylic acids as obtained from Example 1 is converted with acetylene at atmospheric pressure in the presence of the zinc salt of the starting a,a-branched alkane carboxylic acid mixture according to the method as described in e.g. W098/16494. 'he Tg of the homopolymer of thus obtained vinyl ester ras measured to be -32°C. 'or comparison, the Tg of the homopolymer of the C13 ■inyl ester of the a,a-branched saturated carboxylic acid dxture as obtained by example 15 of EP 1033360 Al of ixeno Olefinchemie GmbH was determined to be ~13°C). ixample 3 A 250 ml Hastelloy C autoclave is continuously fed ■ith 3.7 g/minute of a catalyst system, which consists of 1F3/H3P04/water in a BF3/H3PO4 molar ratio 1.5/1 and .54 g/minute butene diraer, obtained by the "DIMERSOL" .ype process (BD2), 32% 3,4-dimethylhexene, 58.8% 3- lethylheptene, 7.2% n-octene, 2% others. The water tontent of the catalyst system is set to 16.3 wt%. The autoclave is eguipped with a manometer, a lechanically driven stirrer, a heating mantel, inlets for 10, olefins, fresh catalyst (for start-up), catalyst •ecycle stream, and a dip-tube for the continuous ■ithdcawing of the product/catalyst mixture. The water ■ecycle is returned to the reaction mixture just before he settling vessel. The temperature in the autoclave is 112°C and the :arbon monoxide pressure of 80 bar is regulated via a >ack-pressure. Subsequently the reaction mixture is separated in a ettling vessel. The lower catalyst rich layer is ■ecycled to the reactor and the upper organic layer is .ontinuously washed, in a packed column, in counter :urrent with water. The water layer from the washing column is recycled to the reactor outlet and the fresh water flow to the column is set a such a rate that the water concentration in the settling vessel maintains at a constant level. The organic layer contains the crude carboxylic acid mixture in a yield of 87 wt% as determined by Gas Chromatography. After removal of the light ends and heavy ends from the organic layer by distillation, the "soft" a,a-branched C9 alkane carboxylic acid mixture is obtained. Example .4 The mixture of a,a-branched alkane carboxylic acids as obtained from Example 3 is converted with acetylene at atmospheric pressure in the presence of the zinc salt of the starting a,t*-branched alkane carboxylic acid mixture according to the method as described in e.g. W098/16494. The Tg of the homopolymer of thus obtained vinyl ester was measured to be -8°C. For comparison, the Tg of the homopolymer of the C9 vinyl ester of the cc,a-branched saturated carboxylic acid mixture as obtained by example 14 of EP 1033360 Al of Oxeno Olefinchemie GmbH was determined to be -3°C). WE CLAIM: 1. A manufacturing process for the preparation of a, a- branched alkane carboxylic acids, by reacting a mono-olefin consisting of a dimmer (Cg) or trimer (C|2) of n-butene comprising predominantly 2-butene, with carbon monoxide in the presence of a strong acid catalyst characterized in that the starting n-butene dimer or n-butene dimer olefin feed has not been fractioned and that the acid catalyst is composed of BF3/H3PO4 in a molar ratio of BF3/H3PO4 in the range of from 0.5:1.0 to 5.0:1.0, or of CF3S03H, that the weight ratio of the catalyst relative to the mono-olefin is in the range of from 1:1 to 10:1, that the reaction is carried out at a temperature in the range of from 60 to 140°C, and with an initial water content in the catalyst system in the range of from 8 to 25 wt%. 2. The manufacturing process as claimed in claim 1, wherein a BF3/H3PO4 catalyst is used, wherein the molar ratio between BF3 and H3PO4 is in the range of from 1: 1 to 3: 1. 3. The manufacturing process as claimed in claims 1 to 2, wherein the carbon monoxide pressure is in the range of from 20 to 100 bar. 4. The manufacturing process as claimed in claims 1 to 3, wherein the reaction temperature is in the range of from 80 to 140°C and the carbon monoxide pressure is in the range of from 30 to 90 bar. 5. The manufacturing process as claimed in claims 1 to 4, wherein the weight ratio of the catalyst relative to the mono-olefin is in the range of from 2: 1 to 6: 1. 6. The manufacturing process as claimed in claims 1 to 5, wherein the manufacturing process is continuous. 7. The manufacturing process as claimed in claims 1 to 6 for the preparation of a, a- branched saturated carboxylic acids, obtained from dimer Cs or trimer Cl2 of n-butene, which predominantly comprise 2-butene, using the nickel catalyzed DIMERSOL or acid catalyzed Montmorillonite oligomerisation process. 8. The manufacturing, process as claimed in claim 7, wherein the acid catalysed Montmorillonite oligomerisation process is used. 9. The manufacturing process for the preparation of a, a- branched alkane carboxylic acids as claimed in any one of claims 1 to 8, wherein the a,a- branched alkane carboxylic acids are further converted to glycidyl esters. 10. A manufacturing process for the preparation of a, a- branched alkane carboxylic acids as claimed in any one of claims 1 to 8, wherein the a, a- branched alkane carboxylic acids are further converted to vinyl esters wherein a homopolymer of the vinyl esters converted from the a,a- branched alkane carboxylic acids having the nine carbon atoms has a Tg lower that -3°C: and wherein a homopolymer of the vinyl esters converted from the a,a- branched alkane carboxylic acids having the thirteen carbon atoms has a Tg lower that -13°C.

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0187-chenp-2004 abstract-duplicate.pdf

0187-chenp-2004 abstract.pdf

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0187-chenp-2004 claims.pdf

0187-chenp-2004 correspondences others.pdf

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0187-chenp-2004 description (complete).pdf

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0187-chenp-2004 petition.pdf