Polybutylene terephthalate
First Claim
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1. The process of carrying out a first stage polyesterification which comprises reacting a polyhydric alcohol and a polycarboxylic acid compound in a concentration of 1.1 to 4 hydroxyl equivalents per carboxyl equivalent under polyesterification conditions at about 180°
- to 250°
C. in the presence of a catalytic concentration of a tetravalent tin compound having one organo to tin linkage, per tin atom wherein 1,4-butane diol provides from 75 to 100 equivalent percent of the hydroxyl groups of the polyhydric alcohol compound, a terephthalic acid compound provides from 75 to 100 equivalent percent of the carboxyl groups of the polycarboxylic acid compound and at least 50 percent of the carboxyl equivalents are provided by terephthalic acid.
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Abstract
Reaction of terephthalic acid and butane diol using a tetravalent tin catalyst having the organo-to-tin linkage.
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Citations
20 Claims
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1. The process of carrying out a first stage polyesterification which comprises reacting a polyhydric alcohol and a polycarboxylic acid compound in a concentration of 1.1 to 4 hydroxyl equivalents per carboxyl equivalent under polyesterification conditions at about 180°
- to 250°
C. in the presence of a catalytic concentration of a tetravalent tin compound having one organo to tin linkage, per tin atom wherein 1,4-butane diol provides from 75 to 100 equivalent percent of the hydroxyl groups of the polyhydric alcohol compound, a terephthalic acid compound provides from 75 to 100 equivalent percent of the carboxyl groups of the polycarboxylic acid compound and at least 50 percent of the carboxyl equivalents are provided by terephthalic acid. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
- to 250°
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10. The process of carrying out a first stage polyesterification which comprises reacting 1,4-butane diol and terephthalic acid in a mole ratio of 1.1 to 2.0 moles of butane diol per mole of terephthalic acid at about 180°
- to 250°
C. in the presence of a tetravalent tin compound having one organo to tin linkage per tin atom. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17, 18, 19, 20)
- to 250°
Specification