Process for production of polytetramethylene-ether-glycol-diester using halloysite catalyst
AssigneeKorea PTG Co., Ltd.
InventorSung-Il Kim
Life of this patent
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Abstract
An improved process for Polytetramethylene-Ether-Glycol-Diesters of the formula R—CO—O(CH2—CH2—CH2—CH2—O)n-COR1, in which R and R1 are identical or different and are alkyl radicals or derivatives thereof, by polymerization of tetrahydrofuran in the presence of a heterogeneous polymerization catalyst and in the presence of a carboxylic anhydride. The use of aluminum silicate catalyst composed of acid-activated and calcinated natural halloysite instead of the known catalytic silicates as bentonite, zeolite or kaolinite. The new catalyst with a very long lifetime produces polymers having more uniform properties and narrow molecular weight distribution even with a relative impure monomer.
Claims14
A process for the preparation of a polytetramethylene ether glycol diester of the formula
- R—CO—O(CH2—CH2—CH2—CH2—O)n-COR1
- wherein
- R and R1 are identical or different alkyl radicals having 1-4 carbon atoms;
- and
- n is an integer from 2 to 200,
- by polymerization of tetrahydrofuran in the presence of a polymerization catalyst and in the presence of a carboxylic anhydride, wherein said catalyst is halloysite mineral activated by acid treatment and calcined.
A process for the preparation of polytetramethylene ether glycol diester of the formula
- R—CO—O(CH2—CH2—CH2—CH2—O)n-COR1
- wherein
- R and R1 are identical or different alkyl radicals having 1-4 carbon atoms;
- and
- n is an integer from 2 to 200,
- by polymerization of tetrahydrofuran in the presence of a polymerization catalyst and in the presence of a carboxylic anhydride, wherein said catalyst is halloysite mineral activated by ammonium chloride treatment and calcined.
Dependencies are inferred from the claim text.