Pulverulent aminoplast adhesive resin for wood-base materials having a low formaldehyde emission, its preparation, and a formulated pulverulent aminoplast adhesive resin

摘要

In the proposed pulverulent aminoplast adhesive resin for wood- base materials having a low formaldehyde emission, the resin is a mixture ofPP(a) from 40 to 90 parts by weight of a urea/formaldehyde resin having a molar ratio of urea to formaldehyde of from 1:1.4 to 1:2,PP(b) from 2 to 20 parts by weight of melamine, some or all of which may have been reacted with the urea/formaldehyde resin component,PP(c) from 2 to 20 parts by weight of urea andPP(d) if required, from 0.1 to 10 parts by weight of an agent for increasing the shelf life,P Ptogether with not more than 10 parts by weight of water and, if required, not more than 10 parts by weight of other additives, the numbers of parts by weight of the components summing to 100.P PIn the process for the preparation of the pulverulent aminoplast adhesive resin, powdered melamine is stirred into a solution of the urea/formaldehyde resin, urea is added and the solution is spray dried. The aminoplast adhesive resins are suitable in the manufacture of particle board, plywood board and as paper adhesives.