摘要:
Stable NCO prepolymers are produced from polyisocyanates having a melting point greater than 70° C., preferably, naphthalene diisocyanate, having advantageous physical properties. An important feature of the process of the present invention is the rapid cooling of the prepolymer. The process of the present invention may be carried out on a continuous or batch basis. The prepolymers of the present invention are particularly suitable for the production of cast polyurethane elastomers.
摘要:
Stable NCO prepolymers are produced from polyisocyanates having a melting point greater than 70° C., preferably, naphthalene diisocyanate, having advantageous physical properties. An important feature of the process of the present invention is the rapid cooling of the prepolymer. The process of the present invention may be carried out on a continuous or batch basis. The prepolymers of the present invention are particularly suitable for the production of cast polyurethane elastomers.
摘要:
The present invention relates to polyester polyols with low functionality and a process for their production, to prepolymers prepared from these polyester polyols and a process for their production, and to polyurethanes prepared from these polyester polyols and/or from these prepolymers, and to processes for their production. These polyester polyols are produced in a two-step process. In the second step of this two-step process, one or more cyclic ester monomers is reacted with one or more polyester polyols at low temperatures.
摘要:
The present invention relates to polyester polyols with low functionality and a process for their production, to prepolymers prepared from these polyester polyols and a process for their production, and to polyurethanes prepared from these polyester polyols and/or from these prepolymers, and to processes for their production. These polyester polyols are produced in a two-step process. In the second step of this two-step process, one or more cyclic ester monomers is reacted with one or more polyester polyols at low temperatures,
摘要:
The present invention relates to a method for preparing oligomeric aliphatic diols, polycarbonatediols based thereon and NCO-terminated prepolymers obtainable therefrom. The inventive compounds may find use in the preparation of polyurethanes.
摘要:
The present invention relates to a process for producing polyether polyols having primary hydroxyl end groups, comprising the steps of reacting a starter compound containing active hydrogen atoms with an epoxide under double metal cyanide catalysis, reacting the resulting product with a cyclic carboxylic anhydride and reacting this resulting product with ethylene oxide in the presence of a catalyst containing at least one nitrogen atom per molecule, excluding non-cyclic, identically substituted tertiary amines. The invention further relates to polyether polyols obtainable by this process, compositions containing said polyols and polyurethane polymers based on said polyols.
摘要:
Polyester polyols are produced from at least one carboxylic acid hydride and diethylene glycol by a process in which the formation of 1,4-dioxane is suppressed. These polyester polyols are useful for producing polyurethane (PUR) and polyisocyanurate (PIR) foams and metal composite elements containing these PUR or PIR foams.
摘要:
The present invention relates to polymer dispersions in polyester polyols, a process for producing them and their use for the production of polyurethanes, in particular microcellular polyurethanes. These polyester polyols have sulfur atoms and are free of olefinically unsaturated groups.
摘要:
The present invention relates to polymer dispersions in polyester polyols, to a process for their preparation, and to the preparation of polyurethanes, especially microcellular polyurethanes, from these polymer dispersions.