Process for production of oxymethylene copolymer
US10138321B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 1, 2015 |
| Grant date | Nov 27, 2018 |
| Priority date | — |
| Expiry date | Dec 1, 2035 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08L59/04
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
The invention provides a method for producing an oxymethylene copolymer including a polymerization step for cationically polymerizing trioxane and a comonomer at a polymerization temperature of from 135 to 300° C. in the presence of at least one salt of a protonic acid having a molecular weight of 1,000 or less, and at least one polymerization initiator selected from the group consisting of protonic acids having a molecular weight of 1,000 or less, protonic acid anhydrides having a molecular weight of 1,000 or less, and protonic acid ester compounds having a molecular weight of 1,000 or less; wherein the total concentration of metal components contained in the trioxane and comonomer used in the polymerization step is 300 ppb by mass or less.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.