Synthetic mineral polymer compound of the silicoaluminates family and preparation process

A method for preparing a mineral polymer formed at a temperature of up to about 120.degree. C. and having a composition, expressed in terms of oxides, as follows:

• yK.sub.2 O:Al.sub.2 O.sub.3 :xSiO.sub.2 :wH.sub.2 O
• where, in the fully hydrated form, "w" is a value at the most equal to 4, "x" is a value in the range of about 4.0 to about 4.2, "y" is a value in the range of about 1.3 to about 1.52, and where the oxide-mole ratios of the reactant mixture from which said mineral polymer is made are as follows:
• ______________________________________ K.sub.2 O/SiO.sub.2 0.30 to 0.38 SiO.sub.2 /Al.sub.2 O.sub.3 4.0 to 4.2 H.sub.2 O/Al.sub.2 O.sub.3 14 to 20 K.sub.2 O/Al.sub.2 O.sub.3 1.3 to 1.52 ______________________________________
• said mineral polymer comprising one phase of a potassium polysilicate having the following formula:
• (y-1)K.sub.2 O:(x-2)SiO.sub.2 :(w-1)H.sub.2 O
• and one phase of a potassium polysialate polymer having the following formula:
• ##STR11## where "n" is the degree of polymerization of said potassium polysialate polymer which comprises reacting potassium silicate with potassium hydroxide and then reacting the resulting mixture with alumino-silicate oxide having the formula:
• (Si.sub.2 O.sub.5, Al.sub.2 O.sub.2).sub.n
• where the aluminum cation is in fourfold coordinated state, or reacting potassium silicate with said alumino-silicate oxide and then reacting the resulting mixture with potassium hydroxide, said mineral polymer having an x-ray diffraction pattern, determined by the Debye-Scherrer method using the K-alpha doublet of copper, substantially as follows:
• d(A) I
• 1- 11. 5 halo
• 4.49 m
• 4.27 w
• 3.52 m
• 3.33 S
• 3.23 halo to
• 2.79 p1 2.56 w
• 2.25 vw
• 2.17 vw.

A method for preparing a molded object which comprises preparing a potassium silico-aluminate/water mixture comprising potassium silicate, potassium hydroxide and alumino-silicate oxide having the formula:

• (Si.sub.2 O.sub.5, Al.sub.2 O.sub.2).sub.n
• without reacting said potassium hydroxide directly with said alumino-silicate oxide, where the molar ratios of the reactants, expressed in terms of oxides, have values in the following ranges:
• ______________________________________ K.sub.2 O/SiO.sub.2 0.30 to 0.38 SiO.sub.2 /Al.sub.2 O.sub.3 4.0 to 4.2 H.sub.2 O/Al.sub.2 O.sub.3 14 to 20 K.sub.2 O/Al.sub.2 O.sub.3 1.3 to 1.52 ______________________________________
• combining said silico-aluminate/water mixture with at least one filler;
• placing said silico-aluminate/filler mixture in a mold;
• said hardening said silico-aluminate/filler mixture in said mold at a temperature of up to about 120.degree. C. to form a solid, molded articles that includes a mineral polymer having a composition, expressed in terms of oxides as follows:
• yK.sub.2 O:Al.sub.2 O.sub.3 :xSiO.sub.2
• where "x" is a value in the range of about 4.0 to about 4.2 and "y" is a value in the range of about 1.3 to about 1.52, said mineral polymer comprising a potassium polysilicate phase, and a potassium polysialate polymer phase having the formula:
• ##STR12## where "n" is the degree of polymerization of said potassium polysialate polymer, said mineral polymer having an x-ray diffraction pattern, determined by the Debye-Scherrer method using the K-alpha doublet of copper, substantially as follows:
• d(A) I
• 1- 11. 5 halo
• 4.49 m
• 4.27 w
• 3.52 m
• 3.33 S
• 3.23 halo to
• 2.79
• 2.56 w
• 2.25 vw
• 2.17 vw.