Cementitious construction material containing magnesium oxychloride crystals
The present invention generally relates to cementitious material that is a precursor of a magnesium oxychloride cement (MOC) and comprises treated carbon fibers comprising a dispersing agent at least partially coating the carbon fibers and processes for the preparation thereof. The present invention is also related to cementitious material that is a precursor of a magnesium oxychloride cement (MOC) and comprises siliconate and processes for the preparation thereof. The present invention further relates to cementitious material (e.g., pourable, extrudable, moldable and formable cementitious material) and cementitious construction material (e.g., boards, structural laminates, etc.) formed from curing the cementitious material.
1 . A cementitious construction material, the cementitious construction material comprising magnesium oxychloride crystals and treated carbon fibers comprising a dispersing agent at least partially coating the carbon fibers, wherein the carbon fibers have a length of from about 4 mm to about 12 mm and an aspect ratio of at least about 250.
2 . The cementitious construction material of claim 1 , wherein the carbon fibers are hydrophobic carbon fibers and the dispersing agent is a dispersing agent suitable for wet-lay applications and capable of compatibilizing the hydrophobic carbon fibers in a hydrophilic matrix.
3 . The cementitious construction material of claim 1 , wherein the dispersing agent is selected from the group consisting of a nonionic component, an anionic component or a blend of non-ionic and anionic components.
4 . The cementitious construction material of claim 1 , wherein the carbon fibers are grade A fibers, grade B fibers, standard modulus fibers, intermediate modulus fibers, high modulus fiber, ultra-high modulus fibers, recycled fibers, or a mixture thereof.
5 . The cementitious construction material of claim 1 , wherein the cementitious construction material is characterized by one or more of the following:
from about 5 wt % to about 50 wt % of a phosphorus-containing amorphous layer, as determined by X-Ray Diffraction; and/or
a magnesium oxychloride crystal content, after a 24-hour soak in water having a temperature of 60° C., of from about 40 wt % to about 90 wt %, as determined by X-Ray Diffraction; and/or
a BET surface area of from about 20 m 2 /g to about 30 m 2 /g.
6 . A cementitious construction material of claim 1 , the construction material in the form of a board having a first surface, a second surface and at least one edge extending between the first surface and second surface.
7 . A cementitious construction material of claim 1 , the construction material in the form of a board having a first surface, a second surface and at least one edge extending between the first surface and second surface, the board further comprising a first layer covering the first surface and a second layer covering the second surface.
8 . A board having a length, a width, and a thickness, wherein the board is constructed from a cementitious construction material of claim 1 , and wherein the board is characterized by one or more of the following:
a cured board density of from about 0.6 to about 1.3 g/mL;
a flexural strength of at least about 2 MPa;
a specific flexural strength of at least about 4 MPa/(g/cm 3 );
a lateral screw pull strength of at least about 40 lbf/inch; and/or
a specific lateral screw pull strength of at least about 150 lbf/in/(g/cm 3 ).
9 . A flooring laminate, the laminate comprising:
a core layer having a first surface having a length and a width, a second surface having a length and a width, and at least one edge extending between the first surface and the second surface, wherein the core layer comprises a cementitious construction material of claim 1 , wherein the cementitious board has a density of from about 0.6 g/mL to about 1.3 g/mL; and
a decorative layer secured to the first surface of the core layer.
10 . A decorative board, the board having a first surface, a second surface, and at least one edge extending between the first surface and second surface, wherein the board comprises a cementitious construction material as set forth in claim 1 .
11 . A flooring material, wherein the flooring material is selected from vinyl tile and vinyl plank and comprises a cementitious construction material as set forth in claim 1 .
12 . The cementitious construction material of claim 1 , wherein the dispersing agent constitutes from about 0.5 wt. % to about 5 wt. % of the total weight of the treated carbon fibers.
13 . The cementitious construction material of claim 1 , wherein the material further comprises a stabilizing material selected from the group consisting of phosphorous acid (H 3 PO 3 ), phosphoric acid (H 3 PO 4 ) and combinations thereof.
14 . The cementitious construction material of claim 1 , wherein the carbon fibers constitute from about 0.1 wt % to about 1.0 wt % of the material.
15 . The cementitious construction material of claim 13 , wherein the magnesium oxychloride crystals are at least partially surrounded by a phosphorus-containing layer.
16 . The cementitious construction material of claim 15 , wherein the phosphorus-containing amorphous layer is substantially free of crystalline silica.
17 . The cementitious construction material of claim 15 , wherein the phosphorus-containing amorphous layer is in the form of a nano-molecular veneer comprising non-crystalline, phosphorus-containing species identifiable by elemental analysis utilizing a scanning electron microscope (SEM).
18 . A multi-layer structural construction material, the material comprising:
a first layer constructed of cementitious construction material comprising magnesium oxychloride crystals and having an outer surface, an inner surface, and at least one edge between the outer surface and inner surface;
a second layer constructed of cementitious construction material comprising magnesium oxychloride crystals and treated carbon fibers comprising a dispersing agent at least partially coating the carbon fibers having a first inner surface, a second inner surface and at least one edge between the inner surfaces; and
a third layer constructed of cementitious construction material comprising magnesium oxychloride crystals and having an outer surface, an inner surface and at least one edge between the outer surface and the inner surface, wherein:
the second layer is disposed between the first layer and the third layer;
the inner surface of the first layer covers the first inner surface of the second layer and the inner surface of the third layer covers the second inner surface of the second layer; and
the cured density of the cementitious construction material of the second layer is less than the cured density of the cementitious construction material of the first layer and the third layer.