公开(公告)号：WO1996006225A1

公开(公告)日：1996-02-29

申请号：PCT/US1994009142

申请日：1994-08-23

Applicant: REYNOLDS METALS COMPANY

Inventor： REYNOLDS METALS COMPANY ,  ARMBRUST, Bernard, P., Jr.

IPC: D21H17/67

CPC classification number: D21H17/675 ,  C01P2004/03 ,  C01P2004/20 ,  C01P2004/51 ,  C01P2004/54 ,  C01P2004/61 ,  C01P2004/62 ,  C01P2006/10 ,  C01P2006/12 ,  C01P2006/60 ,  C01P2006/62 ,  C01P2006/63 ,  C01P2006/64 ,  C09C1/407 ,  D21H17/67

Abstract: A process for preparing an ultra-white alumina trihydrate having a G.E. brightness of at least about 98 %. The product is alumina trihydrate that has been rehydrated with coprecipitation, and the crystal phase of the product is primarily gibbsite in thin platelet form having a ratio of thickness to diameter of about 0.2 to about 0.3. The product is prepared by flash activation of a white initial alumina trihydrate, addition of the activated material to a purified sodium aluminate liquor having an alumina to caustic ratio of about 0.5, and rehydrating and precipitating the alumina at ambient temperature under agitation for about 48 hours, followed by washing and drying of the resulting precipitate. The material is especially useful as a filler or coating in papermaking, and it can be substituted for a portion of titanium dioxide pigment in the ratio of 1:1, and can be combined with titanium dioxide as a pigment mixture, either in slurry form or in dry form. The pigment mixture is added to the papermill machine chest to enhance optical properties beyond those achieved by either pigment alone.

Abstract translation: 一种制备具有G.E.的超白三氧化三铝的方法。 亮度至少约98％。 该产品是已经被共沉淀再水化的三水合氧化铝，并且产物的结晶相主要是薄片形式的三水铝矿，其厚度与直径之比约为0.2至约0.3。 产物通过白色初始氧化铝三水合物的快速活化制备，将活化的材料加入到具有约0.5的氧化铝至苛性碱的纯化铝酸钠溶液中，并在环境温度下再搅拌并沉淀氧化铝约48小时 ，然后洗涤并干燥所得沉淀。 该材料作为造纸中的填料或涂料是特别有用的，它可以以1:1的比例代替二氧化钛颜料的一部分，并且可以与二氧化钛作为颜料混合物以浆料形式或 干燥形式。 将颜料混合物加入到造纸机床中以增强光学性能，而不仅仅是由任一颜料实现的。

公开(公告)号：EP0788571A1

公开(公告)日：1997-08-13

申请号：EP94926497.0

申请日：1994-08-23

Applicant: REYNOLDS METALS COMPANY

Inventor： ARMBRUST, Bernard, P., Jr.

IPC: C09C1 ,  D21H17

Abstract: A process for preparing an ultra-white alumina trihydrate having a G.E. brightness of at least about 98 %. The product is alumina trihydrate that has been rehydrated with coprecipitation, and the crystal phase of the product is primarily gibbsite in thin platelet form having a ratio of thickness to diameter of about 0.2 to about 0.3. The product is prepared by flash activation of a white initial alumina trihydrate, addition of the activated material to a purified sodium aluminate liquor having an alumina to caustic ratio of about 0.5, and rehydrating and precipitating the alumina at ambient temperature under agitation for about 48 hours, followed by washing and drying of the resulting precipitate. The material is especially useful as a filler or coating in papermaking, and it can be substituted for a portion of titanium dioxide pigment in the ratio of 1:1, and can be combined with titanium dioxide as a pigment mixture, either in slurry form or in dry form. The pigment mixture is added to the papermill machine chest to enhance optical properties beyond those achieved by either pigment alone.