The invention concerns the use of cross-linkable silicone compositions for fast, economical and simple impregnation and/or varnishing of flat joints (e.g. cylinder head gaskets). More precisely it concerns the use of silicone compositions cross-linkable under UV radiation, by cationic process and in the presence of specific phoinitiators selected among onium borates or organometallic complexes, of which the borate counter-anions contain at least a boron bound to at least a substituted phenyl (Me, F). The silicone liquid precursor is a polydimethylsiloxane (PDMS) substituted by cross-linking functional groups, by cationic process (G
f
p
) under UV of the epoxy or vinyloxy type. These G
f
p
are present at the rate of 0.15 to 2.0 pr kg of PDMS. The invention also relates to the method for impregnating/varnishing flat joints (e.g. cylinder head gaskets) using the specific PDMS composition+photoinitiator of borate type as well as the treated joints and the composition themselves.
本发明涉及使用可交联的有机
硅组合物,对平面接头(如汽缸盖垫片)进行快速、经济和简单的浸渍和/或上光。更确切地说,它涉及在紫外线辐射下,通过阳离子工艺,在特定的
硼酸鎓或有机
金属络合物(其中
硼酸反离子至少含有一个与至少一个取代苯基(Me,F)结合的
硼元素)存在的情况下,使用可交联的有机
硅组合物。
硅酮液前驱体是由交联官能团取代的聚二甲基
硅氧烷(P
DMS),通过阳离子工艺(G
f
p
)在紫外线下进行环氧或
乙烯基氧基类型的交联。这些 G
f
p
的含量为 0.15 至 2.0 pr kg P
DMS。本发明还涉及使用特定 P
DMS 组合物和
硼酸盐型光
引发剂浸渍/上光平面接头(如气缸盖垫片)的方法,以及处理过的接头和组合物本身。