申请人:Tennebroek Ronald
公开号:US20110200830A1
公开(公告)日:2011-08-18
There is described a formaldehyde-free laminating adhesive, optionally the with less than 3% by weight of co-solvent(s), the adhesive comprising: (I) a polyurethane that comprises from 30% to 65% by weight of hard segments, the polyurethane being obtained and/or obtainable from a first polyurethane dispersion (PUD) comprising the reaction product of (A) an organic isocyanate and (B) at least one chain extender reacting in a respective stoichiometric ratio (NCO to NCO reactive group) from 1:1 to 1:2.5 and; optionally the NCO reactive group(s) of the chain extender comprises one or more hydrazinyl-like group(s) (denoting isocyanate reactive groups selected from the group comprising, preferably consisting of: —NRNR
2
(hydrazinyl groups); —CONRNR
2
(hydrazidyl groups), —NRCONRNR
2
(semicarbazidyl groups); and —ONR
2
(oxyamine groups), where each R is independently selected from H or C
1-10
hydrocarbo); and (II) optionally a second polymer obtained and/or obtainable from a polymer precursor comprising at least one unsaturated moiety, preferably an ethylenically unsaturated group, and where optionally the second polymer may be iminated; with the provisos that: (α) when the first polyurethane does not comprise hydrazinyl-like group(s) then the second polymer is iminated; and (β) when the second polymer is un-iminated or is absent then the first polyurethane comprises hydrazinyl-like group(s). These adhesives may be used to adhere surface veneers to wood and/or to laminate the layers within plywood.
描述了一种无甲醛层压粘合剂,可选地含有少于3%的共溶剂,该粘合剂包括:(I)聚氨酯,其中包括30%至65%的硬段,该聚氨酯是从第一聚氨酯分散体(PUD)中获得和/或可获得的,该分散体包括(A)有机异氰酸酯和(B)至少一种链延伸剂的反应产物,在各自的化学计量比(NCO与NCO反应基)为1:1至1:2.5反应;可选地,链延伸剂的NCO反应基包括一个或多个类似肼的基团(表示从群组中选择的异氰酸酯反应基团,优选包括:-NRNR2(肼基团); -CONRNR2(肼基团),-NRCONRNR2(半脲基团); 和-ONR2(氧胺基团),其中每个R独立地选择H或C1-10烃基);以及(II)可选的第二聚合物,从至少具有一个不饱和基团,优选为乙烯基不饱和基团的聚合物前体中获得和/或可获得,可选地第二聚合物可以亚胺化;条件是:(α)当第一聚氨酯不包括类似肼的基团时,第二聚合物是亚胺化的;(β)当第二聚合物未亚胺化或不存在时,第一聚氨酯包括类似肼的基团。这些粘合剂可用于将表面薄板粘合到木材上和/或在胶合板内层之间进行层压。