Classifications

• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C303/00—Preparation of esters or amides of sulfuric acids; Preparation of sulfonic acids or of their esters, halides, anhydrides or amides
  • C07C303/02—Preparation of esters or amides of sulfuric acids; Preparation of sulfonic acids or of their esters, halides, anhydrides or amides of sulfonic acids or halides thereof
  • C07C303/04—Preparation of esters or amides of sulfuric acids; Preparation of sulfonic acids or of their esters, halides, anhydrides or amides of sulfonic acids or halides thereof by substitution of hydrogen atoms by sulfo or halosulfonyl groups
  • C07C303/06—Preparation of esters or amides of sulfuric acids; Preparation of sulfonic acids or of their esters, halides, anhydrides or amides of sulfonic acids or halides thereof by substitution of hydrogen atoms by sulfo or halosulfonyl groups by reaction with sulfuric acid or sulfur trioxide

Definitions

• This invention relates to the production of alkyl benzene sulphonic acid having the general formula
• R denotes an alkyl group of six to 20 carbon atoms
• the soluble salts of alkyl benzene sulphonic acid have been commercially very important as anionic detergents for many years.
• the customary method of production starts with the appropriate alkyl benzene which is sulphonated and then subsequently neutralised.
• the sulphonation reaction can be carried out in various ways. In the past, the reaction has been carried out using concentrated sulphuric acid or oleum, in either case using an excess of acid. At the end of the sulphonation the surplus acid and the desired product must be separated. Alternatively the entire mixture can be neutralised leading to a product containing a substantial proportion of an inorganic sulphate salt, e.g. sodium sulphate.
• an inorganic sulphate salt e.g. sodium sulphate.
• the sulphur trioxide is normally diluted with some other gas which does not react. Air can be used for this.
• the relative proportions of unconverted alkyl benzene and sulphone impurity vary. They are affected by the reaction conditions employed and by the mole ratio of sulphur trioxide to alkyl benzene. Although it is possible to vary the relative proportions of unreacted alkyl benzene and sulphone it is not possible to avoid both of them simultaneously by control of reaction conditions or mole ratio of reactants. Thus if the mole ratio of sulphur trioxide to alkyl benzene is increased so as to minimise the percentage of unconverted alkyl benzene, the percentage of sulphone increases.
• a method of manufacturing alkyl benzene sulphonate by contacting, as reactants, alkyl benzene with sulphur trioxide using a molar ratio of alkyl benzene to sulphur trioxide in a range from 1:0.9 to 1:1.3, characterised by incorporating sulphuric acid into the reaction mixture after bringing the reactants into contact, the amount of sulphuric acid being not more than 10% by weight of the reaction mixture, and then allowing reaction in the mixture to continue for at least 30 minutes.
• the sulphur trioxide is preferably diluted with another gas, as is conventional.
• This other gas may well be air.
• the ratio of sulphur trioxide to other gas may desirably lie in a range from 3% to 10% by volume.
• the molar ratio of alkyl benzene to sulphur trioxide is preferably in a range from 1:0.9 to 1:1. better 1:0.95 to 1:1.
• the alkyl benzene which is sulphonated may have a straight or branched alkyl group which preferably contains from 10 to 15 carbon atoms.
• branched alkyl benzene has been extensively used for detergent manufacture it is nowadays usually preferred to employ a linear alkyl benzene, that is to say alkyl benzene in which the alkyl group has a straight carbon chain.
• this invention could be employed when it is a mixed feedstock which undergoes reaction.
• the invention is particularly significant when the alkyl benzene feedstock is not mixed with a substantial quantity of any other material so that the feedstock contains in excess of 90% by weight alkyl benzene.
• the sulphuric acid which is added may be in the form of conventional concentrated sulphuric acid containing 98% of sulphuric acid itself. It would also be possible, although it is not preferred, to employ sulphuric acid which is not quite so concentrated. Alternatively it would be possible to employ fuming sulphuric acid containing some oleum.
• the amount of sulphuric acid which is employed is preferably at least 1% and more preferably at least 1.5% by weight of the reaction mixture.
• the amount is preferably not more than 5% of the weight of the reaction mixture and quite possibly not more than 4% by"weight of the reaction mixture.
• Ageing of the reaction mixture after addition of the sulphuric acid preferably takes place with some agitation of the reaction mixture and at a temperature somewhat above normal room temperature, e.g. in the range from 30 to 70°C.
• the ageing period will generally not exceed 12 hours although longer periods may be employed if desired. An ageing period in the range from 2 to 8 hours is preferred. At the end of this ageing period some water may be added to the reaction mixture to hydrolyse any remaining sulphur trioxide and stabilise the reaction mixture, in accordance with conventional practice for sulphonation.
• Alkyl benzene having a molecular weight of approximately 218 corresponding to a formula in which the average value of x is 10 was sulphonated in a commercial sulphonation plant with a multi-tube falling film reactor. Sulphonation was effected using sulphur trioxide and air in an approximate ratio of 1.00.

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• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
• Detergent Compositions (AREA)

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ID=10731993

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Citations (2)

• 1991
  • 1991-03-09 IN IN8594BO1991 patent/IN179248B/en unknown
• 1993
  • 1993-03-11 GB GB939305173A patent/GB9305173D0/en active Pending
• 1994
  • 1994-03-07 JP JP6519582A patent/JPH08507301A/ja active Pending
  • 1994-03-07 CA CA002153488A patent/CA2153488C/en not_active Expired - Fee Related
  • 1994-03-07 DE DE69405553T patent/DE69405553T2/de not_active Expired - Fee Related
  • 1994-03-07 CZ CZ951955A patent/CZ195595A3/cs unknown
  • 1994-03-07 BR BR9405990A patent/BR9405990A/pt not_active IP Right Cessation
  • 1994-03-07 AU AU62830/94A patent/AU6283094A/en not_active Abandoned
  • 1994-03-07 ES ES94910372T patent/ES2107818T3/es not_active Expired - Lifetime
  • 1994-03-07 SK SK1109-95A patent/SK110995A3/sk unknown
  • 1994-03-07 EP EP94910372A patent/EP0690838B1/en not_active Expired - Lifetime
  • 1994-03-07 WO PCT/EP1994/000665 patent/WO1994020458A1/en not_active Ceased
  • 1994-03-07 PL PL94310521A patent/PL310521A1/xx unknown
  • 1994-03-07 HU HU9502630A patent/HUT72425A/hu unknown

Patent Citations (2)

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