| 摘要 |
The invention relates to a multifunctional acrylic product having a number-average functionality f of acrylate groups greater than 2.1, which is the product of reaction by esterification and by etherification, via Michael addition reaction, between a) a polyol or a mixture of polyols R(OH)m having a functionality m of at least 3 for a polyol alone or having an average functionality greater than 2.1 for a mixture of polyols, and b) the acrylic acid (ROH) in the presence of c) at least one cyclic polycarboxylic anhydride or its polyacid form having a carboxy functionality z of at least 2 and up to 4, the ratio r1 of number of carboxy groups of said anhydride or polyacid c) with respect to those of the acrylic acid b) r1 = CO2Hc/CO2Hb being from 0.01 to 0.4 with overall r = CO2H/OH < 1, said acrylic product comprising in its composition both: - units A) of oligoether-ester acrylate that are derived from a) and b) and - units B) of oligoester acrylate that are derived from c), said acrylic product being a mixture of acrylic products comprising at least one acrylic product p1 chemically linking, in its molecular structure, the two types of units A) and B) as defined above. The invention also relates to a process for preparing said product, to crosslinkable compositions comprising same and to the use thereof in coatings, sealing, moulding or composite compositions, chemical sealing compositions, 3D printing compositions or compositions for 3D objects produced layer-by-layer. One particular advantage of these compositions is the low shrinkage thereof despite the high functionality thereof. |
