Polyesterimide
AssigneeSchenectady Chemicals, Inc.
InventorDennis C. Shen
Life of this patent
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Abstract
A low molecular weight polyester-imide resin is prepared wherein there is employed as the dibasic acid either 100% of the diimide dicarboxylic prepared by reacting two moles of trimellitic anhydride with one mole of methylene dianiline (the diimide is abbreviated DID) or oxydianiline or the dibasic acid can also contain a small percent of another aromatic acid. The product is used to produce coated wires having outstanding heat shock. The product also is useful to provide a top coat to wire coated with a polyester or with another polyester-imide.
Claims77
A polyester-imide having a hydroxy to carboxy equivalent ratio of 2.65:1 to 3.67:1, a trihydric alcohol to dihydric alcohol molar ratio of 0.23:1 to 0.62:1, the polyester-imide containing 40 to 50 equivalent % of imide groups, the imide groups being from the imide dibasic acid of the formula ##STR2## the polyester having been made with the following mole percentages of ingredients:
- ______________________________________ Mol % ______________________________________ dihydric alcohol 29-56 trihydric alcohol 9-19 aromatic diamine 11-18 trimellitic anhydride 22-35 aromatic diacid or diester 0-7 ______________________________________
- wherein the dihydric alcohol is ethylene glycol, the trihydric alcohol is tris(2-hydroxyethyl) isocyanurate, the aromatic diamine is methylene dianiline, the mole ratio of trimellitic anhydride to methylene dianiline is about 2:1, the aromatic diacid is terephthalic acid and the aromatic diester is a di(lower alkyl) terephthalate, the polyester-imide has a molecular weight of 700 to 2000, the hydroxyl number of the polyester-imide is 350 to 450, said polyester-imide being capable of forming a single coat insulating coating on an electrical wire capable of withstanding heat shock at 260.degree. C.
A polyester-imide having a hydroxy to carboxy equivalent ratio of 2.65:1 to 4.0:1, a trihydric alcohol to dihydric alcohol molar ratio of 0.23:1 to 0.62:1, the polyester-imide containing 40 to 50 equivalent % of imide groups, the imide groups being from the imide dibasic acid of the formula ##STR3## where X is O or CH.sub.2, the polyester having been made with the following mole percentages of ingredients:
- ______________________________________ Mol % ______________________________________ dihydric alcohol 29-56 trihydric alcohol 9-19 aromatic diamine 11-18 trimellitic anhydride 22-35 aromatic diacid or diester 0-7 ______________________________________
- wherein the dihydric alcohol is ethylene glycol or a mixture of ethylene glycol and a minor amount of another alkanediol, the trihydric alcohol is tris(2-hydroxyethyl) isocyanurate, the aromatic diamine is methylene dianiline or oxydianiline, the mole ratio of trimellitic anhydride to methylene dianiline or oxydianiline is about 2:1, the aromatic diacid is terephthalic acid and the aromatic diester is a di(lower alkyl) terephthalate, the polyester-imide has a molecular weight of 700 to 2000, the hydroxyl number of the polyester-imide is 350 to 450, said polyester-imide being capable of forming a single coat insulating coating on an electrical wire capable of withstanding heat shock at 260.degree. C.
Dependencies are inferred from the claim text.