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.
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.
摘要:
This invention relates to an improved process for the preparation of polyisocyanate mixtures containing biuret groups by the reaction of organic diisocyanates with compounds which react with isocyanate groups to form biuret groups, to the polyisocyanate mixtures obtained by this process and to the use thereof for the preparation of polyurethane resins by the isocyanate polyaddition process.
摘要:
This invention relates to a continuous or discontinuous process for the removal of catalytic quantities of lead ions from aqueous formose solutions by cationic electrodeposition. The process is preferably carried out with a constant current and in at least three stages, with lower current densities being maintained during the first and last stage than in the middle stages.
摘要:
This invention relates to an improved process for the preparation of polyisocyanate mixtures containing biuret groups by the reaction of organic diisocyanates with compounds which react with isocyanate groups to form biuret groups, to the polyisocyanate mixtures obtained by this process and to the use thereof for the preparation of polyurethane resins by the isocyanate polyaddition process.
摘要:
The present invention relates to mixtures which are suitable for use as lacquer powders or as binders for lacquer powders and which are solid and capable of being pulverized at temperatures below about 40.degree. C. and liquid at temperatures above about 150.degree. C., which mixtures comprise(a) an isocyanate component having masked isocyanate groups;(b) a polyhydroxyl component; and, optionally(c) the conventional auxiliary agents and additives;Characterized in that the substance used as component (a) is a polyisocyanate having isocyanurate groups and isocyanate groups which are masked with lactams. The present invention also relates to the use of these mixtures as lacquer powders or as binders for lacquer powders for coating any heat-resistant substrate by the conventional coating methods employed for lacquer powders.
摘要:
The present invention relates to compositions which are storage stable at room temperature and containA) at least one compound having at least two cyclic isourea groups per molecule andB) at least one compound having at least two carboxyl groups per molecule,in an amount sufficient to provide a molar ratio of isourea groups to carboxyl groups of 0.5:1 to 1.5:1.
摘要:
This invention relates to thermosetting compositions for the production of epoxide networks of very high impact strength, to a process for their preparation and to their use as polymer materials, coating compounds, adhesives and materials for electrical insulation.
摘要:
The present invention is directed to novel surface active copolymers and the use thereof in the production of polyurethane powders. More particularly, the copolymers comprise have a substantially linear structure and are obtained by copolymerization ofA) a partial reaction product of1) (meth)acrylic acid or a derivative thereof and2) a macromolecular compound substituted by at least two functional groups selected from OH and NH.sub.2, the functional groups not reacted with Al) being irreversibly blocked, withB) a urethane of 1) a long-chain alkyl isocyanate and 2) a hydroxyalkyl (meth)acrylate.
摘要:
The present invention relates to isocyanto-acylurethanes corresponding to Formula I ##STR1## wherein R has a valency of m+n and is a hydrocarbon group,R' is a hydrocarbon group andm and n may be identical or different, and each have a value of 1 or 2.The present invention also relates to a process for preparation of these isocyanato-acylurethanes which comprises reacting isocyanato-carboxylic acid chlorides with carbamic acid esters. Finally, the present invention is directed to the use of these isocyanato-acylurethanes as intermediate products for the production of thermally cross-linkable synthetic resins or synthetic resin precursors and also as intermediate products for the preparation of cross-linking agents for synthetic resins.