公开(公告)号：US20240116764A1

公开(公告)日：2024-04-11

申请号：US18276592

申请日：2022-01-19

Applicant: EVONIK OPERATIONS GMBH

Inventor： Mareike GIESSELER ,  Frank MENZEL ,  Alexander LYGIN ,  Rainer GOLCHERT

IPC: C01B33/18 ,  C09C1/30 ,  C09C3/12

CPC classification number: C01B33/181 ,  C09C1/3081 ,  C09C3/12 ,  C01P2004/51 ,  C01P2004/61 ,  C01P2006/11 ,  C01P2006/80

Abstract: Process for producing fumed silica powder with a decreased silanol group density, comprising subjecting a fumed surface untreated silica powder with a silanol density dSiOH of at least 1.2 SiOH/nm2 and a particle size d90 of not more than 10 μm, to thermal treatment at a temperature of 350° C. to 1250° C. for 5 min to 5 h, wherein the temperature and the duration of the thermal treatment are chosen so that dSiOH of the silica is decreased by 10%-70% relative to dSiOH of the employed thermally untreated silica, wherein the thermal treatment is carried out while the fumed silica powder is in motion, followed by optional surface treatment. Surface unmodified and modified fumed silica powders obtained by this process and the use thereof.

公开(公告)号：US20240239679A1

公开(公告)日：2024-07-18

申请号：US18560392

申请日：2022-05-03

Applicant: EVONIK OPERATIONS GMBH

Inventor： Mareike GIESSELER ,  Frank MENZEL ,  Alexander LYGIN ,  Rainer GOLCHERT

IPC: C01F7/44

CPC classification number: C01F7/44 ,  C01P2002/01 ,  C01P2002/72 ,  C01P2004/04 ,  C01P2004/51 ,  C01P2006/11 ,  C01P2006/12 ,  C01P2006/82

Abstract: Fumed alumina powder with reduced moisture content Surface unmodified fumed alumina powder comprising less than 5% by weight of alpha-Al2O3, as determined by XRD analysis, having a numerical average particle size d50 of less than 5 μm, as determined by SLS, and a ratio R150=KF150/BET of the water content KF150, as determined by Karl Fischer titration method after drying of the fumed alumina powder at 150° C. for 2 hours, to its BET surface area of not more than 0.0122 wt %×g/m2, preparation method and the use thereof.

公开(公告)号：US20220267160A1

公开(公告)日：2022-08-25

申请号：US17667727

申请日：2022-02-09

Applicant: Evonik Operations GmbH

Inventor： Mareike GIESSELER ,  Frank MENZEL ,  Alexander LYGIN ,  Rainer GOLCHERT

IPC: C01B33/141 ,  G03G9/113 ,  C09D183/04

Abstract: Surface-treated fumed silica, with a tribo-electro static charge of −500 μC/g to +500 μC/g, a ratio of the tribo-electro static charge to BET surface area of −3.5 μC/m2 to +3.5 μC/m2, a methanol wettability of at least 20% by volume methanol in methanol/water mixture, a ratio of carbon content to BET surface area of at most 0.020 wt. %*g/m2, a process for its preparation and the use thereof.

公开(公告)号：US20230062574A1

公开(公告)日：2023-03-02

申请号：US17792471

申请日：2021-01-07

Applicant: EVONIK OPERATIONS GMBH

Inventor： Frank MENZEL ,  Björn LAZAR ,  Bettina GERHARZ-KALTE ,  Alexander LYGIN ,  Mareike GIESSELER ,  Rainer GOLCHERT ,  Nina MÜHLIG ,  Wolfgang AUL ,  Tobias RENGER

IPC: C09C1/30 ,  C09C3/12

Abstract: Fumed silica powder, surface treated with a surface treatment agent selected from the group consisting of organosilanes, silazanes, acyclic polysiloxanes, cyclic polysiloxanes, and mixtures thereof, wherein the powder has: a) a number of silanol groups relative to BET surface area dSiOH of at least 0.85 SiOH/nm2, as determined by reaction with lithium aluminium hydride; b) a methanol wettability of more than 40% by volume of methanol in methanol-water mixture; c) a tamped density of not more than 200 g/L.