申请人:LOCTITE (IRELAND) LIMITED
公开号:EP0785243A2
公开(公告)日:1997-07-23
A method of sealing two abutting metal surfaces such as flanges in face-to-face contact, particularly for use on production lines in the motor industry. The method comprises the steps of:
(i) applying to at least one of the surfaces a sealing composition containing ingredients of a fast-curing anaerobic sealant comprising:
(a) an anaerobically polymerizable liquid monomer selected from acrylate and methacrylate ester monomers,
(b) a primary initiator of free-radical polymerization, and
(c) an accelerator combined with a secondary initiator of polymerization,
at least one of the primary initiator (b) and the accelerator/secondary initiator combination (c) being isolated from the monomer by microencapsulation in microcapsules having walls capable of withstanding a low load but rupturable under a high load,
(ii) bringing the surfaces into abutting relationship under a low load (e.g. less than about 0.1 kg/cm2) which does not rupture the microcapsules, the sealing composition being in contact with both metal surfaces under conditions such that a rapid anaerobic cure would be initiated if one of the ingredients (b) or (c) was not microencapsulated,
(iii) making any desired adjustments in the relationship between the two surfaces, and, if desired, holding the two surfaces in the abutting relationship,
(iv) applying high load pressure forces (e.g. greater than about 3.0 kg/cm2) to bring the surfaces together and to rupture the microcapsules, thus achieving a rapid cure of the composition.
The microcapsules have an average diameter in the range 20-100 micrometres and the microcapsule walls may be of urea/formaldehyde resin.
一种密封两个相邻金属表面(如面对面接触的法兰)的方法,尤其适用于电机行业的生产线。该方法包括以下步骤
(i) 将含有快速固化厌氧密封剂成分的密封组合物涂在至少其中一个表面上,这种密封组合物包括
(a) 可厌氧聚合的液态单体,选自丙烯酸酯和甲基丙烯酸酯单体、
(b) 自由基聚合的主引发剂,以及
(c) 结合了聚合二级引发剂的促进剂、
一级引发剂(b)和促进剂/二级引发剂组合(c)中的至少一种通过微胶囊与单体隔离,微胶囊壁能承受低负荷,但在高负荷下可破裂、
(ii) 在不使微胶囊破裂的低荷载(例如小于约 0.1 千克/平方厘米)下,使两个 金属表面相接,密封组合物与两个金属表面接触,其条件是,如果 (b) 或 (c) 成分之一未被微胶囊包封,则会启动快速厌氧固化、
(iii) 对两个表面之间的关系进行任何所需的调整,并在需要时将两个表面保持 在对接关系中、
(iv) 施加高负荷压力(例如大于约 3.0 千克/平方厘米),使两个表面相接并使微胶囊破裂,从而实现组合物的快速固化。
微胶囊的平均直径在 20-100 微米之间,微胶囊壁可以是脲/甲醛树脂。