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US 12,565,572 B2Granted
Method for preparing polyisocyanate composition
AssigneeHanwha Solutions Corporation
InventorsYujin Sim, Juyoung Park, Byeong Hyeon Lee, Sanghyun Cho
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Abstract
There is provided a method for preparing a polyisocyanate composition capable of improving transparency of a product, by mixing a phenol-based stabilizer in an amount of 1 to 1000 ppmw, based on the total weight of aromatic diisocynate, and then, introducing polyhydric alcohol to conduct a polymerization reaction, thereby inhibiting coloration and whitening due to oxygen or moisture during synthesis and purification processes.
Claims7
A method for preparing a polyisocyanate composition comprising the steps of:
- mixing aromatic diisocyanate and a phenol-based stabilizer to prepare a monomer composition;
- and
- adding polyhydric alcohol having two or more hydroxyl groups in the molecule to the monomer composition and conducting a polymerization reaction,
- wherein a mole ratio of hydroxyl groups in the polyhydric alcohol to isocyanate groups in the aromatic diisocyanate is 0.1 to less than 1, based on 1 mole of isocyanate group in the aromatic diisocyanate, and
- wherein the phenol-based stabilizer comprises a mixture of phenol and dibutylhydroxytoluene at a weight ratio of 10:1 to 5:3 and is used in an amount of 600 to 1000 ppmw, based on the total weight of the aromatic diisocyanate.
2 more elements
Dependencies are inferred from the claim text.