Method for producing plasticizers
AssigneeChisso Corporation
InventorsFumio Sagara, Hiroshi Kawabata, Kiyonori Shiiba
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Abstract
A method for producing plasticizers which contain titanium in only a very small amount is provided. According to this method, the amount of waste water is very small. This method comprises reacting phthalic anhydride with an alcohol having 4-18 carbon atoms in the presence of, as a catalyst, a tetraalkyl titanate or a polymer thereof, and has a feature in the treatment of the resultant ester with a solid alkali and adsorbing agent(s) in the absence of water.
Claims5
In a method for producing dialkyl phthalate plasticizer by esterification in the presence of a tetraalkyl titanate, followed by treatment of the resulting ester with adsorbent(s) and filtration,
- the improvement which comprises:
- (1) reacting phthalic anhydride with an alkanol having 4-18 carbon atoms at a temperature of 150.degree. C.-250.degree. C., for 3-6 hours, in the presence of a tetraalkyl titanate or its polymer to obtain a dialkyl phthalate having an acid value of 0.1 or lower and distilling off the remaining unreacted alkanol from the resulting phthalate at a high temperature and under a reduced pressure;
- (2) subjecting the dialkyl phthalate obtained from the step (1), without the conventional treatment of blowing steam into said dialkyl phthalate after said distilling off, to a contact treatment with a solid alkali selected from the group consisting of sodium carbonate, sodium bicarbonate, calcium carbonate, barium carbonate, sodium hydroxide and potassium hydroxide, in the absence of water, at a temperature of 100.degree. C. to 200.degree. C.;
- (3) treating the resulting liquid obtained in said contact treatment, with adsorbent(s);
- and
- (4) separating the dialkyl phthalate from the resulting material by filtration.
Dependencies are inferred from the claim text.