Patent Description:
<CIT> discloses an insulating material and a method of producing it.

The invention is defined in the appended claims <NUM>-<NUM>. The present invention provides a method for manufacturing an insulating material comprising the steps of:.

In addition, the present disclosure provides an insulating material, which is not claimed, formed from a mixture that includes cement in an amount of about <NUM> to <NUM>% of weight wet, water in an amount of about <NUM> to <NUM>% of weight wet, and a foaming agent. The foaming agent can be an aluminum powder in an amount of about <NUM> to <NUM>% by weight of the cement or a surfactant in an amount of about <NUM> to <NUM>% by weight of the water. The insulating material has a maximum use temperature of about <NUM> degrees Celsius or more, a density in the range of about <NUM> to <NUM>/cm3, a thermal conductivity in the range of about <NUM> to <NUM> W/(m·K), a compressive strength in the range of about <NUM> to <NUM> PSI, and a flexural strength in the range of about <NUM> to <NUM> PSI.

Moreover, the present disclosure provides a method for manufacturing an insulating materia, which is not claimed, by mixing a cement with water, foaming the cement-water mixture using a foaming agent, pouring the foamed cement-water mixture into a mold and allowing the foamed cement-water mixture to rise to form the insulating material, removing the insulating material from the mold and curing the insulating material. The insulating material has a maximum use temperature of about <NUM> degrees Celsius or more.

The above and further advantages of the invention may be better understood by referring to the following description in conjunction with the accompanying drawings, in which:
None.

While the making and using of various embodiments of the present invention are discussed in detail below, it should be appreciated that the present invention provides many applicable inventive concepts that can be embodied in a wide variety of specific contexts. The specific embodiments discussed herein are merely illustrative of specific ways to make and use the invention and do not delimit the scope of the invention.

Ordinary Portland cement (OPC), calcium aluminate cement (CAC), Sorel cement (magnesium oxide and magnesium chloride cements), CSA cement (calcium sulphate aluminate cement), phosphate cement, geo-polymer cement or other cement type known in the State-of-the-Art, in its wet state with water added before setting, can be foamed up with reacting aluminum powder or the use of a surfactant. The more the wet material is foamed by adding higher amounts of aluminum or surfactant, the lighter weight and lower density it will be and as a result the more insulating the set and dried material will be. Following setting and drying, when based on OPC, the insulating material can be used below freezing, minimum -<NUM> degrees Celsius, or have a maximum use temperature up to approximately <NUM> degrees Celsius, and when based on CAC, Sorel cement, CSA cement, phosphate cement, geo-polymer cement or other cement types, the insulating material will have a maximum use temperature up to approximately <NUM> degrees Celsius.

The cementitious binder can be used in combination with a multitude of additive materials such as sand, gypsum, silica fume, fumed silica, plaster of Paris, fly ash, slag, rock, glass fiber, plastic fiber, etc. Moreover, the insulating material can be strengthened by adding a strength increasing admixture, such as fumed silica (e.g., Cab-O-Sil EH-<NUM> or similar by Cabot Corporation).

To make the foamed cement-water mixture, the water to cement ratio by weight is typically in the range of about <NUM> to <NUM>. When foaming mixtures with lower water to cement ratios in the range of about <NUM> to <NUM> these are as an option made more fluid by adding a conventional plasticizer or high range water reducer (HRWR) in an amount of <NUM> to <NUM>% of the cement weight.

As one embodiment, the cement-water-based foam is sometimes stabilized by the addition of a rheology modifying agent. The rheology modifying agent will typically be added in an amount of <NUM> to <NUM>% of the cement weight.

The rheology-modifying agents fall into the following categories: (<NUM>) polysaccharides and derivatives thereof, (<NUM>) proteins and derivatives thereof. Polysaccharide rheology-modifying agents can be further subdivided into (a) cellulose-based materials and derivatives thereof, (b) starch based materials and derivatives thereof, and (c) other polysaccharides.

Suitable cellulose-based rheology-modifying agents include, for example, methylhydroxyethylcellulose, hydroxymethylethylcellulose, carboxymethylcellulose, methylcellulose, ethylcellulose, hydroxyethylcellulose, hydroxyethylpropylcellulose, etc..

Suitable starch based materials include, for example, wheat starch, pre-gelled wheat starch, potato starch, pre-gelled potato starch, amylopectin, amylose, seagel, starch acetates, starch hydroxyethyl ethers, ionic starches, long-chain alkylstarches, dextrins, amine starches, phosphate starches, and dialdehyde starches.

The currently preferred rheology-modifying agent is hydroxypropylmethylcellulose, examples of which are Methocel <NUM> and Methocel <NUM>.

When using aluminum as a foaming agent, the aluminum is typically in a particle size below <NUM> microns. The aluminum can be added as a dry powder, or as a paste in a mixture with water or diethyleneglycol and for some applications can also be used in a retarded version. The preferred aluminum is purchased from the company Eckart (a German company). Typically, the aluminum is added in an amount of about <NUM> to <NUM>% by weight of the cement weight. When foaming OPC cement based mixes, the water and cement are typically mixed first for about <NUM> to <NUM> minutes where after the aluminum is added and mixed for about <NUM> seconds to <NUM> minute. When foaming CAC cement based mixes and most other cement types, the water, cement and rheology modifying agent are typically mixed first for about <NUM> to <NUM> minutes, where after calcium oxide, calcium hydroxide, sodium hydroxide or similar pH increasing agent is added in an amount of about <NUM> to <NUM>% of the water weight and mixed for about <NUM> seconds to <NUM> minute, and finally the aluminum is added and mixed for about <NUM> seconds to <NUM> minute.

When using surfactant as a foaming agent, it is preferred that the water and rheology modifying agent are mixed first to make a viscous water phase that is then mixed with the cement, fiber, and foaming agent. The typical mixing time is about <NUM> to <NUM> minutes depending on the type of mixer. Alternatively, the surfactant can be premixed with <NUM>-<NUM>% of the water to prepare a foam that is then added, or the water mixture can be foamed by passing through a venture-type foaming aggregate nozzle (similar to making shaving foam) that is added to the fiber mixture. The rheology modifying agent is used to stabilize the foam stability and also helps in developing a smaller cell structure in the foam.

By adding a reinforcement fiber to the material increased foam stability will be achieved before setting of the cement, which is especially important when making materials with a dry density in the range of about <NUM> to <NUM>/cm<NUM>. Further, the fiber addition has been found to reduce or eliminate material shrinkage and drying shrinkage cracks during the drying phase of the production process, and further provide increased flexural strength and toughness of the dry material. The preferred type of fiber is cellulose (hardwood or softwood), plastic (based on poly vinyl alcohol or acrylic) and glass fiber; cellulose and plastic fiber is primarily used for insulation intended for below freezing or ambient temperatures, whereas glass fiber is primarily used for insulation intended for temperatures above ambient or where fire resistance is required. Also, combinations of fiber types can be applied. The preferred fiber length is from about <NUM> to <NUM> for the cellulose fiber, about <NUM> to <NUM> for the plastic fiber and about <NUM> to <NUM> for the glass fiber. The preferred fiber diameter is about <NUM> to <NUM> microns.

Following mixing, the mixture is poured into a mold system, which can be in the shape of a pipe, half-pipe, block, panel, sheet or other desired shape. For example, a large mold box (e.g., <NUM> to <NUM> meters long by <NUM> to <NUM> meters wide by <NUM> to <NUM> meters tall, etc.) can be used. When using aluminum powder as a foaming agent, the mixture is allowed to rise (due to the formation of hydrogen bubbles as the aluminum reacts with the hydroxyl ions) and fill the mold over the next <NUM> to <NUM> hours.

When using a surfactant as the foaming agent, the surfactant is specially chosen to have a high degree of foam stability and to generate the right bubble size. One such air entraining agent is sold by the company Sika. The surfactant is typically added in an amount of about <NUM> to <NUM>% of the weight of water. The water, cement, surfactant and rheology modifying agent are typically mixed for about <NUM> to <NUM> minutes to foam up the mixture. Following mixing, the foamed mixture is poured into the mold system and is allowed to set.

Following hardening, the wet material will be de-molded and cut to size, trimmed, etc. For example, a block of the hardened material can be cut into panels, sheets or other desired shapes.

To develop the final <NUM> days strength of products made from OPC cement, the product is either allowed to sit around for <NUM> days in a humid environment, or the strength development can be accelerated within <NUM>-<NUM> hours by heating either by its own internal (exothermic) heat development or by steam curing such as is conventional in the State-of-the-Art.

Products made from CAC cement, Sorel cement, CSA cement, phosphate cement, geo-polymer cement or other cement types will achieve its final strength in <NUM> hours and does not necessarily require additional curing.

After achieving the final strength development, the product is dried to generate the finished lightweight insulating composite.

In one embodiment, the finished product can be made water repellent by spraying the product with water or solvent based silane. Such product, Protectosil BHN, is typically sold by BASF. The finished product can also be sprayed with anti-fungal or anti-microbial coatings. Moreover, the finished product can be painted, stained or textured.

The finished lightweight cement based insulating composite will have a density in the range of about <NUM>-<NUM>/cm<NUM>, a compressive strength in the range of about <NUM>-<NUM> PSI, a flexural strength in the range of about <NUM> to <NUM> PSI, and a heat conductance in the range of about <NUM>-<NUM> W/mK.

The compositional ranges are shown below:.

The cement can be <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>% or <NUM>% by weight or other incremental percentage between.

The water can be <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>% or <NUM>% by weight or other incremental percentage between.

The secondary material can be <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>% or <NUM>% by weight or other incremental percentage between.

The strength increasing admixture can be <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>% or <NUM>% by weight or other incremental percentage between.

The reinforcement fiber can be <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>% or <NUM>% by weight or other incremental percentage between.

The rheology modifying agent can be <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>% or <NUM>% by weight or other incremental percentage between.

The aluminum powder of cement can be <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>% or <NUM>% by weight or other incremental percentage between.

The pH increasing agent can be <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, by weight or other incremental percentage between.

The surfactant of water can be <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>%, <NUM>% or <NUM>% by weight or other incremental percentage between.

Claim 1:
A method for manufacturing an insulating material comprising the steps of:
mixing a cement in an amount of <NUM> to <NUM>% of weight wet with water in an amount of <NUM> to <NUM>% of weight wet and a rheology modifying agent in an amount of <NUM> to <NUM>% of a weight of the cement, wherein the cement comprises a calcium aluminate cement (CAC), a Sorel cement, a CSA cement, a phosphate cement, or a geo-polymer cement and the rheology modifying agent is selected from the group consisting of polysaccharides, polysaccharide derivatives, proteins, and protein derivatives;
foaming the cement-water-rheology modifying agent mixture using a foaming agent comprising an aluminum powder in an amount of <NUM> to <NUM>% by weight of the cement or a surfactant in an amount of <NUM> to <NUM>% by weight of the water;
pouring the foamed cement-water mixture into a mold and allowing the foamed cement-water mixture to rise to form the insulating material;
removing the insulating material from the mold; and
the insulating material having a maximum use temperature of <NUM> degrees Celsius, a density in the range of <NUM> to <NUM>/cm<NUM>, a thermal conductivity in the range of <NUM> to <NUM> W/(m·K), a compressive strength in the range of <NUM> to <NUM> kPa (<NUM> to <NUM> PSI), and a flexural strength in the range of <NUM> to <NUM> kPa (<NUM> to <NUM> PSI).