A process for the preparation of composite filler particles, comprising:
(a) coating a particulate filler having a median particle size (D50) of from 1 to 1200 nm with a coating composition containing a film-forming agent forming a coating layer on the surface of the particulate filler, said coating layer displaying reactive groups on the surface of the coating layer, said reactive groups being selected from addition polymerizable groups and step-growth polymerizable groups, thereby forming a coated particulate filler; subsequently or concurrently
(b) agglomerating the coated particulate filler, optionally in the presence of a further crosslinking agent and optionally in the presence of a further particulate filler not displaying reactive groups, for providing a granulation of the coated particulate filler wherein the granulation contains the coated particulate filler particles and the optional further particulate filler particles separated from and connected to each other by at least one coating layer, whereby the at least one coating layer may be crosslinked by crosslinking groups obtained by reacting the reactive groups and optionally a further crosslinking agent;
(c) optionally milling, classifying and/or sieving the granulation of the coated particulate filler; and
(d) optionally further crosslinking the granulation of the coated particulate filler; for providing composite filler particles having a median particle size (D50) of from 1 to 70 µm, wherein reactive groups are transformed into crosslinking groups obtained by reacting reactive groups and optionally a further crosslinking agent, and wherein the particulate filler is the main component by volume of the composite filler particles.
一种制备复合填料颗粒的工艺,包括
(a) 在中值粒径(D50)为 1 至 1200 nm 的颗粒填料上涂覆含有成膜剂的涂覆组合物,在颗粒填料表面形成涂覆层,所述涂覆层表面显示反应基团,所述反应基团选自加成聚合基团和阶跃生长聚合基团,从而形成涂覆颗粒填料;随后或同时
(b) 使涂覆颗粒填料团聚,可选择在有进一步
交联剂存在的情况下,也可选择在有不显示反应基团的进一步颗粒填料存在的情况下,以提供涂覆颗粒填料的粒状物,其中粒状物包含涂覆颗粒填料颗粒和可选择的进一步颗粒填料颗粒,它们通过至少一个涂覆层相互分离和连接,其中至少一个涂覆层可通过反应基团和可选择的进一步
交联剂反应获得的交联基团交联;
(c) 可选地对涂层颗粒填料的造粒进行研磨、分级和/或筛分;以及
(d) 可选地进一步交联包覆颗粒填料的造粒;用于提供中值粒径(D50)为 1 至 70 微米的复合填料颗粒,其中反应基团转化为通过反应基团和可选的进一步
交联剂反应获得的交联基团,颗粒填料是复合填料颗粒体积的主要成分。