Classifications

• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C51/00—Preparation of carboxylic acids or their salts, halides or anhydrides
  • C07C51/16—Preparation of carboxylic acids or their salts, halides or anhydrides by oxidation

Definitions

• the present invention provides a process for preparing saturated, high molecular weight, aliphatic monocarboxylic acids by oxidizing a-olefms having from 16 to 70 carbon atoms in the molecule or mixtures of such a-olefins in the molten state by means of aqueous chromosulfuric acid, which comprises adding to the molten olefins or mixtures of olefins prior to oxidizing of from 2 to 15% by weight, calculated on the olefins, of aliphatic monoor dialcohols having from to 40 carbon atoms in the molecule-optionally in the form of their fatty acid esters and then oxidizing with aqueous chromosulfuric acid.
• the proportion of neutral matter in the oxidation products may be reduced by 10 to 50% or even more.
• Suitable starting materials for the chromosulfuric acid oxidation according to the invention are for example a-olefins having more than carbon atoms in the molecule, for example l-hexadecene, l-octadecene and l-eicosene or a-olefins having up to about 70 carbon atoms, which may be prepared by oligomerizing ethylene. Commercial mixtures of a-olefins having from 22 to 28 or from 24 to 48 carbon atoms are preferably used.
• aliphatic alcohols are saturated monoalcohols having from 10 to 40 carbon atoms, preferably straight chain primary alcohols, as for example decyl alcohol, dodecyl alcohol, tetradecyl alcohol, cctyl alcohol and especially stearyl alcohol and behenyl alcohol, moreover glycoland polyglycol monoalkyl ethers having higher alkyl groups, such as the etheralcohol glycol-monostearyl ether.
• Synthetic monoalcohols for example those, prepared according to the known polyethylene synthesis with Ziegler catalysts followed by oxidative hydrolysis of the aluminium trialkyls are also suitable.
• Aliphatic dialcohols having from 10 to 40 carbon atoms for example a,w-diols, such as l, l0-decane-diol or 1,19mondecane-diol, and optionally polyalkylene glycols are also suitable; it should be taken into consideration however that dicarboxylic acids are generally formed in the oxidation of diols, so that the use of diols is not recommended, if the acids resulting from the oxidation shall be free from dicarboxylic acids.
• Esters of higher monoalcohols or diols with fatty acids having 2,3 or from 16 to 40 carbon atoms for example stearyl acetate, stearyl stearate and esters of the montanic acid are also suitable. They are first saponified under the oxidation conditions, so that their efficiency finally is based on the presence of the basic alcohols.
• the aliphatic monoalcohols or diols are added to the molten a-olefin or a-olefin mixture to be oxidized in an amount of from 2 to 15, preferably of from 4 to 10 by weight, calculated on the olefins.
• the oxidation is carried out in known manner.
• Chromosulfuric acid containing per liter from 50 to 140 g of CrO preferably from to 120 g and from 300 to 650 g, preferably from 400 to 550 g of H 80 is used as oxidizing agent.
• the oxidation temperature is in the range of from 60 to 180C, preferably of from to 120C.
• the quantity of oxidizing agent required is from to 250 preferably from to 200 of CrO calculated on the weight of the olefin-alcohol mixture to be oxidized.
• the oxidation is preferably carried out as follows:
• the molten olefin-alcohol mixture is introduced into the chromosulfuric acid heated to the desired oxidation temperature by small amounts or continuously and the mixture is vigorously stirred during the whole reaction. It is also possible to add the oxidizing agent to the molten mass of the product to be oxidized. According to a preferred method the reaction is carried out in a multiple-stage process, while separating the depleted oxidant after each step.
• the oxidation times are generally in the range of from 4 to 8 hours.
• the high molecular weight, aliphatic carboxylic acids or carboxylic acid mixtures obtained having a relatively low content of neural matter are colourless and thermostable and are especially suitable for preparing waxlike esters, partial esters and amides, which may be used as lubricants in the plastics processing and in the preparation of floor waxes and polishing pastes.
• synthelic alcohol according to Ziegler, having 24 carbon atoms "aarnonadecane diol molecule, or their fatty acid esters, and then oxidizing with the aqueous chromosulfuric acid at a temperature of 60 to 180C.
• aqueous chromosulfuric acid used is a chromosulfuric acid containing per liter of from 50 to g of CrO and from 300 to 650 g of H 50

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• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Engineering & Computer Science (AREA)
• Oil, Petroleum & Natural Gas (AREA)
• Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)

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Citations (4)

• 1974
  • 1974-08-15 CA CA207,125A patent/CA1028354A/en not_active Expired
  • 1974-08-19 NL NL7411058A patent/NL7411058A/nl not_active Application Discontinuation
  • 1974-08-19 US US498567A patent/US3923848A/en not_active Expired - Lifetime
  • 1974-08-22 GB GB3694274A patent/GB1452571A/en not_active Expired
  • 1974-08-22 FR FR7428797A patent/FR2241527B1/fr not_active Expired
  • 1974-08-23 JP JP49096238A patent/JPS5076017A/ja active Pending
  • 1974-08-26 BE BE147918A patent/BE819199A/xx unknown

Patent Citations (4)

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