发明授权
US4255529A Process for the preparation of cellular or non-cellular polyurethane resins 失效
制备细胞或非细胞聚氨酯树脂的方法

Process for the preparation of cellular or non-cellular polyurethane
resins
摘要:
This invention relates to an improved process for the preparation of formose by the condensation of aqueous formaldehyde. In the process according to this invention, tertiary amines which contain an electrophilic hetero atom in the .beta.-position to the tertiary nitrogen atom are used for controlling the pH instead of the inorganic bases which have previously been used for this purpose.
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