Process for the preparation of cocondensates which form a weatherproof adhesive bond

    公开(公告)号:DE3145328A1

    公开(公告)日:1983-06-01

    申请号:DE3145328

    申请日:1981-11-14

    Applicant: BASF AG

    Abstract: A further embodiment of the process for the preparation of aqueous solutions of products of the condensation of formaldehyde and at least urea, melamine and phenol, in which the molar proportion of phenol, based on the sum of melamine and urea, is from 0.05 to 0.25, and the molar ratio between urea and melamine is from 0.2:1 to 1:0.2, at a total molar ratio between formaldehyde and the sum of melamine, urea and phenol of from about 1.1 to 2, the condensation products being usable as adhesive resins, in which, in each case in a manner known per se, phenol, formaldehyde and up to 0.35 mol of an alkali metal bisulphite per mol of phenol are reacted to form a phenol-formaldehyde condensate, and formaldehyde and urea are reacted in a molar ratio of 2.5 or less to form a urea-formaldehyde condensate, and the reaction products are themselves reacted with melamine and formaldehyde in such a ratio that the molar ratios between melamine, urea, phenol and formaldehyde mentioned at the outset are either produced directly or after a further reaction with up to 75% of the total intended amount of urea, in accordance with Patent Application P 3125874.3, characterised in that an effective amount of phenol of less than 0.05, based on the sum of melamine and urea, is proposed.

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