Calcium silicate board and method of manufacturing same

A method of manufacturing a light-weight calcium silicate board comprising;

• a step of forming a material slurry into a prescribed shape of a molded body, said material slurry comprising, as a solid component, 17 to 50 wt % of calcareous material, 15 to 45 wt % of silica containing material, 2 to 8 wt % of fiber material and 5 to 40 wt % of inorganic fillers;
• and
• a step of hydrothermally reacting the obtained molded body in a pressure container, wherein 2 to 20 wt % of at least one kind of amorphous silica containing material or silica material, each having a specific surface area of 1 m.sup.2 /g or more, is used as a portion of said silica containing material;
• and, before said hydrothermal reaction, said molded body is subjected to primary curing under conditions represented by a formula (curing temperature--15).times.curing time.gtoreq.120.degree. C..multidot.hr.

A method of manufacturing a calcium silicate board having a bulk specific gravity of 0.70 or less comprising:

• a step of forming a material slurry in layers by a sheet machine process and forming a molded body therefrom, said material slurry comprising, as a solid component, 5 to 35 wt % of calcareous material, 5 to 40 wt % of silica containing material, 2 to 8 wt % of fiber material, 5 to 40% of inorganic fillers, and a gel obtained from 2 to 20 wt % of calcareous material for gelation and 3 to 25 wt % of silica containing material for gelation;
• and
• a step of a hydrothermally reacting the obtained molded body in a pressure container, wherein 2 to 20 wt % of at least one kind of amorphous silica containing material or silicate material, each having a specific surface area of 1 m.sup.2 /g or more, is used as a portion of said silica containing material;
• and, before said hydrothermal reaction, said molded body is subjected to primary curing under conditions represented by a formula (curing temperature--15).times.curing time.gtoreq.120.degree. C..multidot.hr. so that a flexural strength of said molded body under a wet condition is 7 kg/cm.sup.2 or more and is 1.3 times higher than that before primary curing.

A method of manufacturing a calcium silicate board having a bulk specific gravity of 0.70 or less comprising;

• a step of forming a material slurry in layers by a sheet machine process and forming a molded body therefrom, said material slurry comprising, as a solid component, 5 to 35 wt % of calcareous material, 5 to 40 wt % of silica containing material, 2 to 8 wt % of fiber material, 5 to 40% of inorganic fillers, and a gel obtained from 2 to 20 wt % of calcareous material for gelation and 3 to 25 wt % of silica containing material for gelation;
• and
• a step of a hydrothermally reacting the obtained molded body in a pressure container, wherein 2 to 20 wt % of at least one kind of amorphous silica containing material or silicate material, each having a specific surface area of 1 m.sup.2 /g or more, is used as a portion of said silica containing material;
• further, said material slurry contains 20 wt % or less of a curing agent selected from the group consisting of Portland cement, alumina cement and granulated blast furnace slag;
• and, before said hydrothermal reaction, said molded body is subjected to primary curing under conditions represented by a formula (curing temperature--10).times.curing time.gtoreq.120.degree. C..multidot.hr. so that a flexural strength of said molded body under a wet condition is 7 kg/cm.sup.2 or more and is 1.3 times higher than that before primary curing.

A method of manufacturing a calcium silicate board having a bulk specific gravity of 0.70 or less comprising;

• a step of forming a material slurry in layers by a sheet machine process and forming a molded body therefrom, said material slurry comprising, as a solid component, 5 to 35 wt % of calcareous material, 5 to 40 wt % of silica containing material, 2 to 8 wt % of fiber material, 5 to 40 wt % of inorganic fillers, and a gel obtained from 2 to 20 wt % of calcareous material for gelation and 3 to 25 wt % of silica containing material for gelation;
• and
• a step of a hydrothermally reacting the obtained molded body in a pressure container, wherein said material slurry contains 20 wt % or less of a curing agent selected from the group consisting of Portland cement, alumina cement and granulated blast furnace slag;
• and, before said hydrothermal reaction, said molded body is subjected to primary curing under conditions represented by a formula (curing temperature--10).times.curing time.gtoreq.120.degree. C..multidot.hr. so that a flexural strength of said molded body under a wet condition is 7 kg/cm.sup.2 or more and is 1.3 times higher than that before primary curing.