TWO-STAGE METHOD FOR PRODUCING MOLDED PRODUCT
Molded articles are produced in a two-stage process. In the first stage, an organic polyisocyanate is reacted with an organic compound containing at least two epoxide groups (NCO: epoxide equivalent ratio of 1.2:1 to 500:1) in the presence of a tertiary amine catalyst. This reaction is stopped when...
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Zusammenfassung: | Molded articles are produced in a two-stage process. In the first stage, an organic polyisocyanate is reacted with an organic compound containing at least two epoxide groups (NCO: epoxide equivalent ratio of 1.2:1 to 500:1) in the presence of a tertiary amine catalyst. This reaction is stopped when no more than 65% of the isocyanate groups have reacted by adding an alkylating sulfonic acid alkyl ester of methyl iodide and/or of dimethyl sulfate in an amount equivalent to the amount of tertiary amine catalyst present. A latent catalyst capable of being activated by heat is subsequently added to the intermediate product and the resultant mixture is heated in a mold to complete the crosslinking of the intermediate product and to form the molded article. |
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