Ube Industries, Inc.

Hideki Noguchi

Tomohiko Yamamoto

Yukio Inaba

Joji Funatsu

Genji Koga

Oxamide is produced in a high purity by a process comprising (A) melting a starting material comprising 70 to 100 wt % of an oxalic acid diester of an aliphatic alcohol and 0 to 30 wt % of the same aliphatic alcohol as mentioned above, (B) feed-mixing an ammonia-containing gas to the starting material melt, while stirring, to produce oxamide and the aliphatic alcohol (by-product), (C) continuing the ammonia-feed-mixing procedure while controlling a feed rate of ammonia to an extent such that a content of the aliphatic alcohol in the reaction mixture is maintained at a level of 3 to 45% by weight, to produce a wetted solid reaction product comprising the resultant oxamide and the aliphatic alcohol, and then (D) collecting the oxamide from the reaction product by evaporating away the aliphatic alcohol.

Process for producing oxamide

Oxamide granules are produced by (A) feed-mixing ammonia to a starting material comprising 60 to 100 weight % of a diester of oxalic acid with a C.sub.1-6 aliphatic alcohol, and 0 to 40 weight % of the same aliphatic alcohol as mentioned above, to produce oxamide and the aliphatic alcohol as by-product, while controlling the aliphatic alcohol content to 5 to 40% based on the weight of the reaction mixture to provide the resultant oxamide wetted by the aliphatic alcohol; (B) granulating the wetted product while maintaining the content of the aliphatic alcohol at a level of 5 to 40% based on the weight of the wetted reaction product; (C) heat-evaporating away the aliphatic alcohol from the wetted granules; and optionally (D) re-wetting the resultant dry oxamide granules with water in an amount of 5 to 20% based on the weight of the dry oxamide granules; and (E) re-drying the re-wetted oxamide granules, to provide oxamide granules having an enhanced mechanical strength and form-stability in water.

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Ube, Japan

Hideki Noguchi