Organic compounds and processes for their manufacture

Details Organic compounds and processes for their manufacture Organic compounds and processes for their manufacture

1999-11-24

2001-10-23

Padmanabhan, Sreeni (Department: 1621)

Organic compounds -- part of the class 532-570 series

Organic compounds

Carboxylic acid esters

C560S263000, C560S076000, C562S512000, C568S448000, C252S062200, C252S062200, C252S068000, C524S298000, C508S485000

Reexamination Certificate

active

06307093

ABSTRACT:

FIELD OF THE INVENTION
This invention relates to a process for the manufacture of aldehydes, alcohols, acids, and their derivatives. The invention also relates to the uses of the compounds, especially to the use of the alcohols and their derivatives, to the uses of the esters, both of the alcohols and acids, and of salts of the acids. More especially, the invention relates to the use of esters as synthetic lubricants and as plasticizers, to polymeric compositions plasticized by the esters, and to products made from the compositions. Certain of the compounds are novel.
BACKGROUND OF THE INVENTION
The esters of 2-ethylhexanol, especially the phthalate, are among the most commonly used plasticizers. The alcohol is obtainable by, for example, subjecting propene to hydroformylation, dimerizing the resulting butanal by the aldol reaction, a term which is used throughout this specification, including the claims, as including the subsequent dehydration to an unsaturated aldehyde, and hydrogenating the resulting aldehyde to form a saturated alcohol.
The propene, produced for example by a steam cracking plant, has to be purified before hydroformylation, and its cost as feedstock is increased as a result.
Although the plasticizer esters derived from 2-ethylhexanol are widely used, for some purposes, for example where a lower volatility, or a stronger solvator for the polymer is needed, higher molecular weight esters, for example those based on nonanol, are preferred. The C
9
esters presently available commercially are typically derived from an isomeric mixture of C
9
alcohols and the users' requirements for product consistency may result in manufacturing complexities.
These complexities result from variations in feed composition and reaction conditions in the process for the manufacture of the precursors to the alcohols. These precursors may be formed for example by oligomerizing a mixed C
3
to C
5
olefin feed, giving a mixture of linear and branched olefins, predominantly having six to ten carbon atoms, from which is distilled a mixed C
8
olefin, which is in turn hydroformylated (oxonated) and hydrogenated to form the isomeric C
9
alcohol mixture.
In other commercial processes, the C
9
alcohol precursors are typically obtained by-dimerizing butene streams and oxonating the resulting C
8
olefin fraction. The butene stream itself contains a mixture of isomers, in proportions that may vary over a period, and the cobalt oxo process causes some isomerization. Thus the alcohols resulting from hydrogenation of the aldehyde form a reaction product of variable isomer distribution together with lower and higher homologues, necessitating further treatment if customers' product specifications are to be met.
In a typical commercial process for the manufacture of a plasticizer ester, the alcohol is employed in excess over the acid, and alcohol is stripped from the ester product and recycled. Any impurities and any less reactive isomers tend to concentrate in the reaction vessel as the reaction progresses, resulting in a change in the composition over time. In turn, the downstream users' quality control inspection of the incoming product is more onerous than if it were a single isomer.
Processing of thermoplastics containing a multi-isomer plasticizer may be more difficult to control in certain applications, resulting in a greater possibility of inconsistencies in properties between different batches of the final product.
This in turn may require the user to have tighter control over process variables, e.g., oven temperature ranges in motor vehicle paintshops and flooring material lines, than would otherwise be necessary, and also complicates material recycling.
In applications employing the corresponding acids, there is an even greater requirement for purity, for example when the acids are being employed in synthetic lubricant manufacture, or in peroxide polymerization initiator manufacture.
Finally, effluent and environmental monitoring is more difficult; e.g., a single isomer material may have a minimum detectability an order of magnitude lower than a multi-isomer material.
There accordingly remains a need for an alternative route to commercially useful organic molecules, and more especially one that provides flexibility and a greater control of product structure, particularly the ability to produce single isomers if desired.
In addition there remains a need for a route sufficiently flexible to be able to use different feedstocks of varying purity, particularly feedstocks from the various natural gas sources emerging around the world.
BRIEF SUMMARY OF THE INVENTION
The present invention provides a process for the manufacture of a saturated aliphatic C
9
aldehyde which comprises subjecting a C
6
aldehyde to an aldol condensation with propanal to form an unsaturated C
9
aldehyde and hydrogenating the C
9
aldehyde to form a saturated C
9
aldehyde.
Optionally, the saturated C
9
aldehyde is hydrogenated further to the corresponding alcohol, which is optionally esterified, or the C
9
aldehyde may be oxidized to the corresponding acid. If desired, however, the unsaturated C
9
aldehyde may instead be hydrogenated in a single stage to the saturated alcohol (in which process the saturated aldehyde is typically formed as an intermediate but not isolated), to a mixture of saturated aldehyde and alcohol, or to an unsaturated alcohol.
The saturated C
6
aldehyde may be obtained, for example, as will be described in more detail below, from a composition containing a C
2
unsaturated hydrocarbon and/or synthesis gas (CO & H
2
) obtainable, for example, by conversion of a natural gas stream. A stream containing both these components may be subjected to hydroformylation conditions, and the resulting propanal-containing composition subjected to aldolization, the resulting hexenal (which is largely a single isomer) being hydrogenated to form the starting C
6
saturated aldehyde, the last-mentioned steps or the latter step being carried out, if desired, in conjunction with the aldol condensation to form a C
9
aldehyde.
As a further route to a saturated C
6
aldehyde, a synthesis gas stream may be subjected to the Fischer-Tropsch process, to yield, when a cobalt catalyst is used primary alcohols and, when an iron catalyst is used, inter alia, linear &agr;-olefins. These products may be dehydrogenated and oxonated, respectively, to give mainly normal aldehydes. Other routes include oxonation of a pentene, and the formation of Ziegler alcohols by catalytic treatment of ethylene to form a range of higher alcohols and dehydrogenation to aldehydes. Separation of the desired carbon number material may take place at any suitable stage in these processes.
The present invention also provides a process comprising
(a) subjecting a composition comprising a C
2
unsaturated hydrocarbon, carbon monoxide and hydrogen to hydroformylation conditions to form a propanal-containing composition,
(b) subjecting the propanal-containing composition to first and second aldol condensations, causing trimerization to an unsaturated C
9
aldehyde and, optionally,
(c) hydrogenating an intermediate unsaturated C6 aldehyde resulting from the first aldol condensation to a saturated C
6
aldehyde and, optionally,
(d) hydrogenating the C
9
aldehyde to a saturated aldehyde, the C
9
aldehyde being the doubly unsaturated product of step (b), the singly unsaturated product resulting from aldol condensation of the product of step
(c) with a further propanal molecule, or a mixture of the product of step (b) and the said-singly unsaturated product and, optionally,
(e) oxidizing the product of step (d) to form a C
9
acid or optionally
(f) hydrogenating the product of step (b) or step (d) to form a saturated C
9
alcohol and, optionally,
(g) esterifying the saturated C
9
alcohol resulting from step (f).
The invention further provides a process comprising
(b) subjecting a propanal-containing composition to first and second aldol condensations, causing trimerization to an unsaturated C
9
aldehyde,
(c) hydrogenating an intermedi

Affiliated with

Also associated with

Rating

Organic compounds and processes for their manufacture does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Organic compounds and processes for their manufacture, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Organic compounds and processes for their manufacture will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2594140