The invention relates to a mold material mixture for producing casting molds for metal processing, a process for producing casting molds, casting molds which can be obtained by the process and their use. The production of the casting molds is carried out using a refractory base molding material and a binder based on water glass. A proportion of a particulate metal oxide selected from the group consisting of silicon dioxide, aluminium oxide, titanium oxide and zinc oxide is added to the binder, with particular preference being given to using synthetic amorphous silicon dioxide. The mold material mixture contains a surface-active material as further significant constituent. The addition of the surface-active material enables the flowability of the mold material mixture to be improved, which makes it possible to produce casting molds having a very complicated geometry.

A structure for manufacturing a cast article includes an organic component, at least a portion thereof being an organic fiber. The structure has a mass reduction rate of 1 mass % or greater to less than 20 mass % when heated under nitrogen atmosphere at 1000 C. for 30 minutes. The cast-article-manufacturing structure includes an inorganic particle. The cast-article-manufacturing structure includes, as the inorganic particle, a first inorganic particle having a predetermined shape and/or physical property, and a second inorganic particle having a predetermined shape and/or physical property different from the first inorganic particle. In addition thereto or instead thereof, the cast-article-manufacturing structure has a maximum bending stress of 9 MPa or greater measured in conformity with JIS K7017, and a bending strain of 0.6% or greater at the maximum bending stress.

A structure for manufacturing a cast article includes an organic component, at least a portion thereof being an organic fiber. The structure has a mass reduction rate of 1 mass % or greater to less than 20 mass % when heated under nitrogen atmosphere at 1000 C. for 30 minutes. The cast-article-manufacturing structure includes an inorganic particle. The cast-article-manufacturing structure includes, as the inorganic particle, a first inorganic particle having a predetermined shape and/or physical property, and a second inorganic particle having a predetermined shape and/or physical property different from the first inorganic particle. In addition thereto or instead thereof, the cast-article-manufacturing structure has a maximum bending stress of 9 MPa or greater measured in conformity with JIS K7017, and a bending strain of 0.6% or greater at the maximum bending stress.

A structure for manufacturing a cast article includes an organic component, at least a portion thereof being an organic fiber. The structure has a mass reduction rate of 1 mass % or greater to less than 20 mass % when heated under nitrogen atmosphere at 1000 C. for 30 minutes. The cast-article-manufacturing structure includes an inorganic particle. The cast-article-manufacturing structure includes, as the inorganic particle, a first inorganic particle having a predetermined shape and/or physical property, and a second inorganic particle having a predetermined shape and/or physical property different from the first inorganic particle. In addition thereto or instead thereof, the cast-article-manufacturing structure has a maximum bending stress of 9 MPa or greater measured in conformity with JIS K7017, and a bending strain of 0.6% or greater at the maximum bending stress.

A structure for manufacturing a cast article includes an organic component, at least a portion thereof being an organic fiber. The structure has a mass reduction rate of 1 mass % or greater to less than 20 mass % when heated under nitrogen atmosphere at 1000 C. for 30 minutes. The cast-article-manufacturing structure includes an inorganic particle. The cast-article-manufacturing structure includes, as the inorganic particle, a first inorganic particle having a predetermined shape and/or physical property, and a second inorganic particle having a predetermined shape and/or physical property different from the first inorganic particle. In addition thereto or instead thereof, the cast-article-manufacturing structure has a maximum bending stress of 9 MPa or greater measured in conformity with JIS K7017, and a bending strain of 0.6% or greater at the maximum bending stress.