Process for the manufacture of α, α-branched carboxylic acid vinyl esters

Abstract

The invention relates to a process for the manufacture of α,α-branched carboxylic acids vinyl esters comprising the following steps: isomerising and converting an olefin feed with CO and water under Koch reaction conditions to make an acid with a ratio of Non Blocking isomers (NB) versus Blocking isomers (B) of NB/B above 1.5, wherein a blocking isomer has always a tertiary carbon atom in alpha position of the carboxylic acid and in the beta position of the carboxylic acid, whereas a non-blocking isomer has primary carbon atoms in the beta position of the carboxylic acid converting the resulting acid into a vinyl ester.

Claims

1. A composition of α,α-branched carboxylic acid vinyl esters from propylene oligomers comprising: a vinyl ester mixture derived from neo-acids, which neo-acids are derived from a propylene oligomer olefin feed having an isomer ratio of (BR1+BR2)/BR3=Ya above 20, with BR1=weight of propylene oligomer olefin with one branching alkyl group, BR2=weight of propylene oligomer olefin with two branching alkyl groups and BR3=weight of propylene oligomer olefin with three or more branching alkyl groups, wherein the neo-acids have a ratio of Non Blocking isomers (NB) versus Blocking isomers (B) of NB/B above 1.5, where the αcarbon atom is always quaternary, the carbon atom(s) in β position can either be secondary, tertiary, or quaternary, acids with a tertiary or a quaternary carbon atoms in the β position are defined as blocking isomers.

2. The composition of claim 1 wherein the propylene oligomer olefin feed is mainly a trimer of propylene or mainly a tetramer of propylene.

3. The composition of claim 1 wherein the vinyl ester mixture is derived from the reaction of the neo-acids with acetylene in presence of a zinc catalyst.

4. The composition of claim 3, wherein the reaction has a throughput of at least 5.3 ton/hour.

5. The composition of claim 1, wherein the neo-acid is derived from the Koch reacion of a propylene oligomer that is mainly a trimer of propylene with Ya composition.

6. A copolymer comprising the vinyl esters produced according to claim 1.

7. The copolymer of claim 6, wherein the copolymer comprises vinyl ester of a C10 neo-acid and vinyl acetate.

8. The composition of claim 7 wherein the C10 acid is derived from a propylene oligomer that is mainly a trimer of propylene with Ya composition.

9. The copolymer of claim 7, wherein the copolymer comprises a 25/75 ratio of vinyl ester of the C10 neo-acid to vinyl acetate, and has a glass transition temperature of 26.5° C. or lower.

10. A polymer composition for coating, adhesive or composite applications, comprising the copolymer of claim 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

(1) The invention is described in more detail hereinafter. The invention is described with respect to propylene oligomers. However, it is to be understood that the improved process may be used with other olefin mixtures with a high content of highly branched isomers as well. Thus, the inventors have found new Koch reaction conditions that allow conversion of commercially available propylene oligomers at improved throughput into a vinyl ester of an α,α-branched carboxylic acid.

(2) The vinyl esters produced accordingly show attractive properties in coating, adhesive or composite applications. They have copolymer Tg (V10/VA: 25/75) of 26.5° C. or lower, wherein V10 represents the vinylester of a C10 acid, and VA represents vinyl acetate.

(3) A propylene oligomer composition is rather complex and variable. For example, the composition of a PT3 may contain olefins with 6, 7, 8, 9, 12 and more carbon atoms. The commercially available PT3 grades generally contain from 90 to 98 weight % of C9. However the isomeric composition within the C9 differs greatly, which has been found to influence the vinylation step.

(4) The current process of the invention comprises the determination of the isomeric composition of the olefin mixture, using KOCH reaction conditions that are adapted to the isomeric composition.

(5) Determination of the isomer composition of e.g. a PT3 stream may be done in various ways. One is by hydrogenating the olefin mixture and identification by gas chromatography. The isomers so identified may be grouped in isomers with one branching alkyl group (such as methyl octane) (BR1), with two branching alkyl groups (such as dimethyl heptane) (BR2) and with three (or more) branching alkyl groups (such as trimethyl hexane) (BR3). Table 1 reports the different isomers identified in PT3 feeds. Identification of the hydrogenated PT3 stream was done to simplify the isomer composition of the alkene content of PT3. In theory 219 C9 alkene isomers are possible and after hydrogenation only 38 C9 alkane isomers are derived there from. So for example the 2,3-dimethylheptane can be produced from 10 different “nonene” isomers by hydrogenation, see Table 1 for the complete overview.

(6) TABLE-US-00001 TABLE 1 Nonane isomers in a hydrogenated PT3 stream and identification by gas chromatography Number of Code Name alkene (1) Level branching 901 n-nonane 7 0 902 2-methyloctane 11 1 903 3-methyloctane 13 1 904 4-methyloctane 13 1 905 2,2-dimethylheptane 7 2 906 2,3-dimethylheptane 10 2 907 2,4-dimethylheptane 10 2 908 2,5-dimethylheptane 10 2 909 2,6-dimethylheptane 4 2 910 3,3-dimethylheptane 6 2 911* 3,4-dimethylheptane 16 2 911* 3,4-dimethylheptane 2 912* 3,5-dimethylheptane 7 2 912* 3,5-dimethylheptane 2 913 4,4-dimethylheptane 3 1 914 3-ethylheptane 8 1 915 3-ethylheptane 7 1 916 2,2,3-trimethylhexane 6 3 917 2,2,4-trimethylhexane 6 3 918 2,2,5-trimethylhexane 4 3 919 2,3,3-trimethylhexane 4 3 920* 2,3,4-trimethylhexane 9 3 920* 2,3,4-trimethylhexane 3 921 2,3,5-trimethylhexane 7 3 922 2,4,4-trimethylhexane 3 3 923 3,3,4-trimethylhexane 5 3 924 3-ethyl-2-methylhexane 10 2 925 3-ethyl-3-methylhexane 4 2 926 3-ethyl-4-methylhexane 8 2 927 4-ethyl-2-methylhexane 6 2 928 2-ethyl-2,2-dimethylpentane 3 3 929 2-ethyl-2,3-dimethylpentane 2 3 930 2-ethyl-2,4-dimethylpentane 4 3 *stereoisomers (1): number of alkene with this backbone structure

(7) From the complete study for the reaction cascade from the olefin oligomer up to the vinyl ester derived from; the inventors have found that ratio of (BR1+BR2)/BR3=Y will determine the throughput of vinylation reaction. When an olefin mixture is used for the Koch reaction wherein Y is above 20 (Ya) the subsequent vinylation reaction is faster than when an olefin mixture is used wherein Y is below 20 (Yb).

(8) It is hypothesized that a Ya type PT3 after the Koch reaction using mild reaction conditions (80° C., 80 bar of CO and about 18% weight water in the acid catalyst) leads to a composition of branched carboxylic acids derived from the branching level of the Ya-PT3 composition without significant isomerisation during the reaction and lead to an acid isomeric composition with a higher proportion of “non blocking” isomers (NB), as defined below, over the amount of “blocking” isomers (B).

(9) Blocking isomers of Neo-caboxvlic Acids

(10) Whereas the carbon atom in alpha position of the carboxylic acid is always a quartenary carbon atom, the carbon atom(s) in β position can either be secondary, tertiary, or quaternary. Neodecanoic acids (V10) with a tertiary or a quaternary carbon atom in the β position are defined as blocking isomers (Schemes a & b).

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(12) Blocking isomers not only comprise alkyl groups on the (alpha) carbon next to the acid group, which is therefore a quaternary carbon atom, but also one or more alkyl groups attached to the next (beta, β) atom. Non-blocking isomers on the other hand have beta atoms (β) that are secondary (i.e., without branching).

(13) Preferably, vinylation is carried out on a mixture of carboxylic acids containing both non blocking isomers and blocking isomers in a ratio NB/B that is greater than 1.5.

(14) Interestingly, by selecting more severe reaction conditions for the production of the branched carboxylic acids (by Koch reaction) starting from a type Yb PT3 feed the inventors have found that they could produce Ya-type C10 branched carboxylic acids.

(15) Isomerisation may be performed in the Koch reaction by various means. For instance, the isomerisation seems to take place under the Koch conditions when the level of water in the catalyst is below 12 wt % for a residence time of at least 30 minutes.

(16) By including an isomerisation step in the Koch reaction, resulting in a NB/B ratio of at least 1.5, it was therefore found that the throughput of the reaction improved from a 4.2-4.5 ton/hour for a type Yb PT3 feed to 5.3-5.6 ton/hour.

(17) This improvement was found, starting from the branched carboxylic acids produced according to the modified Koch reaction and reacting the same with acetylene and Zn catalyst.