申请人:AGFA-GEVAERT
公开号:EP1217010A1
公开(公告)日:2002-06-26
A method has been disclosed of preparing ultrafine hydrophobic latex particles of polymers and copolymers by free radical emulsion polymerization in a water-based system, making use therefor, in order to polymerize or copolymerize monomers or monomer mixtures respectively, of at least one compound selected from the group consisting of dimers and cobalt complexes, acting as a chain transfer agent (CTA), wherein said latex particles have an average particle size of less than 100 nm, being more than 10 % lower than if prepared in the absence of said CTA, characterized in that said polymerization is conducted in a water-based reaction in the presence of a chain transfer agent and of a surfactant, wherein said surfactant is present in a concentration versus said monomer or monomer mixture of from 5 up to 25 % by weight for a non-ionic surfactant or from 0.05 up to 10 % by weight for an ionic surfactant. Particularly preferred is a surfactant concentration below twice its critical micelle concentration.
Moreover use of ultrafine hydrophobic latex particles of polymers and copolymers, prepared according to the claimed method has been described and illustrated in the examples, in printing plates for computer-to-plate or computer-to-press applications, in silver halide based graphic, medical, cinematographic and micrographic film materials, in photoresist applications and in ink-jet media.
本发明公开了一种在水基体系中通过自由基乳液聚合法制备聚合物和共聚物的超细疏水性胶乳颗粒的方法,该方法利用至少一种选自由二聚体和钴络合物组成的组中的化合物作为链转移剂(CTA),分别聚合或共聚单体或单体混合物、其中所述胶乳颗粒的平均粒径小于 100 nm,比不使用所述 CTA 的情况下的粒径小 10%以上,其特征在于所述聚合反应是在链转移剂和表面活性剂存在下的水基反应中进行的,其中所述表面活性剂相对于所述单体或单体混合物的浓度为:非离子表面活性剂为 5%至 25%(按重量计),或表面活性剂为 0.05 至 10%(按重量计)。特别优选的是表面活性剂浓度低于其临界胶束浓度的两倍。
此外,根据上述方法制备的聚合物和共聚物的超细疏水性胶乳颗粒的用途已在实施例 中进行了描述和说明,如用于计算机直接制版或计算机直接印刷的印版,基于卤化银的 图形、医疗、电影和显微摄影胶片材料,光刻胶应用和喷墨介质。