US 11,717,879 B2
Use of closed-pore microspheres of expanded pearlite as a filler for the production of mouldings for the foundry industry
Sandra Lehmann, Potsdam (DE); Klaus Riemann, Wunstorf (DE); Nils Zimmer, Garbsen (DE); Hermann Lieber, Langenhagen (DE); and Jürgen Hübert, Langenhagen (DE)
Assigned to HÜTTENES-ALBERTUS CHEMISCHE WERKE GESELLSCHAFT MIT BESCHRÄNKTER HAFTUNG, Düsseldorf (DE)
Appl. No. 16/92,115
Filed by HÜTTENES-ALBERTUS CHEMISCHE WERKE GESELLSCHAFT MIT BESCHRÄNKTER HAFTUNG, Düsseldorf (DE)
PCT Filed Apr. 10, 2017, PCT No. PCT/EP2017/058584
§ 371(c)(1), (2) Date Oct. 8, 2018,
PCT Pub. No. WO2017/174826, PCT Pub. Date Oct. 12, 2017.
Claims priority of application No. 10 2016 205 960.2 (DE), filed on Apr. 8, 2016.
Prior Publication US 2019/0118244 A1, Apr. 25, 2019
Int. Cl. B22C 1/16 (2006.01); B22C 1/22 (2006.01); B22C 1/18 (2006.01); B22C 1/02 (2006.01); B22C 9/08 (2006.01); C04B 35/634 (2006.01); C04B 35/63 (2006.01); C04B 38/08 (2006.01); C04B 38/00 (2006.01)
CPC B22C 1/167 (2013.01) [B22C 1/02 (2013.01); B22C 1/183 (2013.01); B22C 1/2253 (2013.01); B22C 1/2273 (2013.01); B22C 9/088 (2013.01); C04B 35/6303 (2013.01); C04B 35/63404 (2013.01); C04B 35/63476 (2013.01); C04B 38/0061 (2013.01); C04B 38/085 (2013.01); C04B 2235/3427 (2013.01)] 10 Claims
OG exemplary drawing
 
1. A molding for the foundry industry, produced using
closed-pore microspheres of expanded perlite, having a closed foam structure with pores separated from one another, and wherein the microspheres are closed on their surface;
wherein the microspheres have a particle size d50 of 200 to 250 μm;
expanded glass;
wherein a weight ratio of perlite to expanded glass ranges from 1:1 to 1:2;
and an organic or inorganic binder or a mixture of organic and inorganic binder, wherein the binder is selected from the group consisting of water glass, phenol-formaldehyde resins, two-component systems comprising as reactants a polyisocyanate and a polyol component containing free hydroxyl groups (OH groups), and starch
wherein the closed-pore microspheres of expanded perlite have a bulk density from 200 to 500 kg/m3.