Abstract: An accelerator for accelerating the rate of hydration of calcined gypsum is disclosed. The accelerator comprises calcium sulfate dihydrate particles and a starch. The starch has a cold water solubility of at least about 25% (e.g., at least about 35%) and a viscosity of about 25 Brabender Units (BU) or less when the starch is in a 30% aqueous slurry at 92° C. Also disclosed are a method of preparing an accelerator, method of hydrating stucco to form set gypsum, slurry, and method of making gypsum board.

Abstract: A modified gypsum set accelerator and a method of preparing the same is provided, which includes dry loose finely ground particles of a mixture of ground dry calcium sulfate dihydrate and a grinding aid selected from one or more of beta-naphthalene sulfonate formaldehyde condensate, trimetaphosphate phosphate salt, tripolyphosphate salt, tetra-pyrophosphate salt, and pregelatinized starch.

Abstract: A slurry for manufacturing gypsum board is disclosed. The slurry comprises calcined gypsum, water, a foaming agent, and a thickening agent. The thickening agent of the present disclosure acts to improve the cohesiveness of the slurry without adversely affecting the setting time of the slurry, the paper-to-core bond (wet and dry), or the head of the slurry by acting as a defoaming agent or coalescing agent. Examples of suitable thickening agents include cellulose ether and co-polymers containing varying degrees of polyacrylamide and acrylic acid. A gypsum board and method of forming the slurry and the gypsum board are also disclosed. The gypsum board comprises a gypsum layer formed from the slurry.

Abstract: The invention describes a composite material for heat storage comprising a thermochemical material (TCM) encapsulated in a water vapor permeable polymeric material. The thermochemical material preferably comprises at least one salt, at least one salt hydrate or a mixture of these, wherein the salt is preferably capable of binding water in an exothermic reaction, such as calcium chloride. Encapsulation in a water vapor permeable polymeric material results in an improved stability, cyclability of the thermochemical material, a reduced regeneration temperature and reduced corrosion of the environment. The composite according to the invention is particularly suitable for energy storage, preferably in the field of building and construction, and more preferably in the seasonal storage of solar energy.

Abstract: An aqueous tape joint compound including: an inorganic filler; an emulsion polymer binder; cellulose ether thickener; water; and from 0.01 to 1.3% by weight based on the weight of the aqueous joint compound, water-soluble polymer or salts thereof, the water-soluble polymer selected from the group consisting of (a) polymer consisting essentially of, as polymerized units, from 50% to 100%, by weight based on the weight of the polymer, acrylic acid, and from 0% to 50%, by weight based on the weight of the polymer, second monoethylenically unsaturated acid monomer, (b) diisobutylene-maleic anhydride polymer, and (c) mixtures thereof; the water-soluble polymer having a weight average molecular weight of from 1500 to 75,000 and a calculated Tg of from 80° C. to 250° C.; the aqueous tape joint compound being substantially free from calcium sulfate hemihydrate is provided.

Abstract: Embodiments of a process for manufacturing a paper-based malleable dough for moulding and sculpting applications are described herein that include: soaking and mixing shredded paper in water, yielding a paper dough; and adding and mixing at least one setting-type joint compound with the paper dough. The at-least one setting type compound is added in a weight ratio of setting type compound to shredded paper of between about 11:8 to 17:8. The paper-based malleable dough allows creating objects that are ecological, durable, malleable and lightweight and that brings out the creative side of the user.

Abstract: Provided are an additive for skim coat mortar and a skim coat mortar composition including the same, and the additive is a blend of cellulose ether having hydroxyalkylalkyl cellulose cross-linked with an aldehyde compound and hydroxyalkyl cellulose cross-linked with an aldehyde compound. By applying the additive to a skim coat mortar composition, it is possible to improve workability, surface luster, and a creamy property while maintaining a water retention property.

Abstract: A gypsum panel that incorporates a plant fiber other than paper is disclosed. The plant fiber material may be in the form of a facing material adhered to at least one side of the gypsum panel or in the form of loose fibers integrated with the gypsum panel as a matrix or both. Further, the plant fiber may be combined with conventional gypsum panel additives, is fully recyclable and environmentally sustainable. The present invention further relates to a method of making such a gypsum panel.

Abstract: A composite panel is made from wood and cementitious binders, with flat surfaces and several possible colors. The panel comprises 35 to 85% of grey or white Portland cement; 10 to 30% of debarked resinous wood particles; 5 to 20% of semi-hydrated calcium sulphate; 0 to 10% of a surface accelerator; 0 to 10% of aluminum sulphate solution; 0 to 30% of calcium carbonate; and 0 to 15% of pigments. The process of preparation for the existing VIROC panel is adjusted to the new material. This panel, in addition to being very resistant and showing high performances in terms of resistance to impact, humidity, temperature variation, noise and fungi, as well as other microorganisms, also complies with all the requirements of the associated product standard.

Abstract: An inorganic material board, which is a cured mat formed by dehydrating a slurry including 30 to 53 wt % of blast furnace slag, 2 to 5 wt % of gypsum having an average particle size of 200 to 2000 ?m, 5 to 11 wt % of alkaline material, 5 to 15 wt % of reinforcing fibers, and 31 to 50 wt % of inorganic admixture with respect to a total solid content, and in which a weight ratio of the blast furnace slag to the gypsum to the alkaline material is 1:0.05 to 0.15:0.15 to 0.35. It is desirable that the blast furnace slag has a specific surface area of 3000 to 5000.

Abstract: An inorganic board contains, in a solid content ratio, 30 to 70 mass % of hydraulic material, 5 to 15 mass % of reinforcing fiber, and 1 to 30 mass % of wollastonite having a wet volume (after being allowed to stand for 30 minutes) of 15 to 45 ml. Also, a method includes: step of producing a slurry containing hydraulic material, reinforcing fiber, and wollastonite; step of producing a sheet by dehydrating the slurry; and step of pressing and curing the sheet; wherein, in the step of producing a slurry, a composition of the slurry is set so as to contain, in a solid content ratio, 30 to 70 mass % of hydraulic material, 5 to 15 mass % of reinforcing fiber, and 1 to 30 mass % of wollastonite having a wet volume (after being allowed to stand for 30 minutes) of 15 to 45 ml.

Abstract: An aqueous gypsum plaster-cement composition comprises a hydraulic binder consisting of calcined gypsum and hydraulic cement in a weight ratio of from about 4:1 to about 2:1, an aggregate which comprises sand, a foam, a perlite, rice hulls or a mixture thereof, a superplasticizer comprising an air entraining agent, a retarder, and water in an amount of from about 0.4 to about 0.75 parts by weight per part of binder, with the proviso that the gypsum plaster-cement composition contains essentially neither a pozzolana nor lime. The use thereof, a method of constructing buildings using this composition and the buildings obtainable in this way are also described.

Abstract: A method of curing cementitious material comprising added a carboxylated bleached wood pulp fiber to the material during mixing. The fiber has a carboxyl content of from 10 to 70 meq/100 g cellulose fiber. The fibers are 0.1 to 5% by weight of the dry weight of the cementitious material. The structure produced by the method. The autogenous shrinkage of the cementitious material is reduced.

Abstract: A cement product incorporating nanocrystalline cellulose and cellulose fiber throughout the product and a method of making the product.

Abstract: A cement product incorporating nanocrystalline cellulose and cellulose fiber throughout the product and a method of making the product.

Abstract: The present invention relates to an extrudable hydraulic or non-hydraulic binding composition with improved properties with respect to crack formation and a method of making such a composition. The invention further relates to a method of decreasing or avoiding the formation of cracks of an extruded hydraulic or non-hydraulic binding composition and to a method of making an extruded article having less or no cracks. Furthermore, the invention is directed to a cellulose ether providing an extrudable hydraulic or non-hydraulic binding composition with improved properties with respect to crack formation.

Abstract: The present invention relates to polysaccharide derivatives having an adjusted particle morphology for use in the preparation of a hydrolytically setting composition having an adjusted lump rating. The invention further relates to a method of adjusting the lump rating of a hydrolytically setting composition comprising adjusting the particle morphology of a particulate polysaccharide derivative. Furthermore, the invention is directed to a hydrolytically setting composition comprising a particulate polysaccharide derivative having an adjusted particle morphology. The invention is also directed to various uses of the particulate polysaccharide derivative having an adjusted particle morphology.

Abstract: The present invention relates in general to implantable compositions, and method for preparing same, containing a calcium salt-containing component, optionally demineralized bone, a plurality of discrete fibers, optionally a flow additive, and optionally continuous reinforcing fibers or an array of organized fibers in the form of mesh. Advantageously, the discrete fibers have a specific aspect ratio (length/diameter) from about 50:1 to about 1000:1. The addition of a small amount of discrete fibers and/or the continuous reinforcing fibers or fiber mesh can cause drastic increases in certain mechanical properties including flexural strength, flexural toughness, and/or screw pullout strength.

Abstract: The present invention relates to the preparation of methylhydroxypropylcellulose (MHPC) and the use thereof in mineral-bound building material systems, preferably in gypsum-bound building material systems, particularly preferably in gypsum machine plaster.

Abstract: The present invention describes a fire resistant building material composition, useful for example as a fire door core and to a method of making this composition where the building material of the present invention is prepared from an aqueous slurry of calcined gypsum, paper fibers, a water insoluble organic binder, fiber reinforcement and a set retarder.

Abstract: An energy efficient method for making a gypsum cellulose fiberboard comprising adding a first portion of cellulose fiber to gypsum before the gypsum and cellulose fiber are co-calcined in a reactor, adding a second portion of cellulose fiber to the slurry after it leaves the reactor to form a second slurry, depositing the slurry to form a mat, dewatering the mat, rehydrating the mat and then finishing the mat to form a final gypsum cellulose fiberboard. A reduction of up to about 40% to 50% of steam energy used can be achieved when the second portion of added cellulose fiber is 50% or more of the total cellulose fiber used in the final board compared to gypsum cellulose board made with the same ingredients but when all of the fiber is added to the gypsum prior to the reactor.

Abstract: A joint compound system includes a set-inhibited, pre-wetted, setting-type, ready-mix joint compound and a set initiator. The set-inhibited, pre-wetted, setting-type joint compound includes a ready-mixed, setting-type joint compound base with a calcium-free phosphate set preventing agent that impedes chemical hydration of a gypsum component of the setting-type joint compound. The joint compound base is free of calcium carbonate. The set initiator includes alum to reinitiate the chemical hydration reactions.

Abstract: The present invention relates in general to implantable compositions, and method for preparing same, containing a calcium salt-containing component, optionally demineralized bone, a plurality of discrete fibers, optionally a flow additive, and optionally continuous reinforcing fibers or an array of organized fibers in the form of mesh. Advantageously, the discrete fibers have a specific aspect ratio (length/diameter) from about 50:1 to about 1000:1. The addition of a small amount of discrete fibers and/or the continuous reinforcing fibers or fiber mesh can cause drastic increases in certain mechanical properties including flexural strength, flexural toughness, and/or screw pullout strength.

Abstract: Hydraulic compositions comprising a setting accelerator, a water-soluble cellulose ether having a degree of alkyl substitution of 1.6 to 2.5 which is a water-soluble alkyl cellulose or a water-soluble hydroxyalkyl alkyl cellulose, and water are useful as self-leveling compositions having an excellent self-leveling capability, a minimal change with time of fluidity, and a short setting time, or as cement mortar compositions having a long open time and a short setting time.

Abstract: A carbohydrate-gypsum composite for use as a bonding agent in manufacturing gypsum construction materials is disclosed. The composite includes a carbohydrate substituted with sulfate moieties such as cellulose sulfate and a crystalline calcium sulfate dihydrate. The composite may be used in bonding paper cover sheets to a gypsum core to form a gypsum wallboard. Also disclosed are methods of making the composite and methods of making gypsum wallboard with the composite.

Abstract: The invention is a composition of an architectural papier-mâché, and articles made therewith. Articles formed from using the architectural papier-mâché have excellent weather resistance, and can be used outdoors, as well as indoors. The composition is comprised of cellulose insulation and a joint compound. Cellulose insulation is a paper-based material, like newsprint or phonebook paper that is shredded and chemically treated with boric acid, which imparts resistance to mold, mildew, fungus, insects, moisture and flammable combustion.

Abstract: A method for forming a gypsum slurry comprises the steps of combining gypsum and water to form a slurry, combining cellulose ether with at least a second material configured to delay solubilization of the cellulose ether, and adding the combined cellulose ether and at least a second material to the slurry.

Abstract: A wall repair compound useful for filling and repairing cracks, holes, and other imperfections in a wall surface includes a conventional filler material, a conventional binder material, and a dust reducing additive which reduces the quantity of airborne dust particles generated when sanding the hardened joint compound. Airborne dust reducing additives include oils, surfactants, solvents, waxes, and other petroleum derivatives. The additive can be added to conventional ready-mixed joint compounds and to setting type joint compounds. A method of reducing the quantity of airborne dust generated when sanding a fully hardened joint compound includes mixing a sufficient quantity of the dust reducing additive with the joint compound prior to when the joint compound has been applied to the wall.

Abstract: The preparation of gypsum parts (dihydrate calcium sulfate) with high mechanical resistance is obtained with the aid of water layers with nanometric thickness. Calcium sulfate is used, dihydrate as well as hemihydrate, to obtain parts from these two materials, pure or mixed, especially to use in construction work, where the parts are prepared by compressing their slightly humidified powders.

Abstract: The object of the invention is a drying compound comprising from 50 to 85% of FGD gypsum and/or natural or processed gypsum, in mass percentages based on the total mass of the compound, presenting the following particle size characteristics: (i) a d50 from 35 to 70 ?m and (ii) a span (d90?d10/d50) lower than 2. The object of the invention is also a preparation process of the compound according to the invention. Finally, the object of the invention is a building process of a structure using this compound.

Abstract: Hydraulic compositions comprising a setting accelerator, a water-soluble cellulose ether having a degree of alkyl substitution of 1.6 to 2.5 which is a water-soluble alkyl cellulose or a water-soluble hydroxyalkyl alkyl cellulose, and water are useful as self-leveling compositions having an excellent self-leveling capability, a minimal change with time of fluidity, and a short setting time, or as cement mortar compositions having a long open time and a short setting time.

Abstract: Articles, including fiberboard, are made from a pumpable, flowable slurry including alpha-calcined calcium sulfate hemihydrate anchored in pores of host particles, alpha-calcined calcium sulfate hemihydrate, a silicone compound, magnesium oxide, and water. The magnesium oxide catalyzes the reaction of the silicone compound into a silicone resin. In a preferred method of making a water resistant fiberboard calcium sulfate dihydrate is combined with the host particles and water to form a slurry which is heated under pressure to calcine the calcium sulfate dihydrate to form alpha-calcined calcium sulfate hemihydrate. After relieving the pressure, a silicone compound and magnesium oxide are added to the slurry. The slurry is dewatered to form a filter cake, which is then formed into a desired shape and allowed to set.

Abstract: Gypsum products and method for the preparation thereof are disclosed. The gypsum products comprise an interlocking matrix of set gypsum that is formed from a composition comprising calcined gypsum, water and acoustical tile.

Abstract: In conjunction with water, a mixture can be used to prepare a sprayable slurry that hydrates to form a machinable plaster composition. The mixture includes from about 80% to about 98% by weight calcium sulfate hemihydrate, from about 1% to about 5% by weight adhesive binder for adhering said plaster mixture to a substrate and from about 0.001% to about 10% of a polysaccharide. The mixture is made into a slurry by the addition of from 10% to about 50 weight water based on the weight of the mixture.

Abstract: A composition comprising cellulose ether, a superplasticizer and defoamer suitable for use as an additive in extruding inorganic compositions is disclosed. The inventive composition functions as a water retention agent, plasticizer and lubricant in the extrusion of inorganic compositions. The use of the inventive composition in the extrusion of building materials leads to improved processing properties, to a higher surface quality and product properties of the extruded article.

Abstract: In at least one embodiment, the present invention relates to a gypsum composition suitable for use in the manufacture of construction materials comprising a) gypsum, b) water, and c) a water repellancy composition comprising a hydroxy-based cellulose and a siliconate.

Abstract: An alternative cover for landfill may be formed from a slurry mixture of water, cementitious binder, adhesion enhancing admixture and fiber. These constituents may be mixed and applied to cover landfilled wastes, granular material piles or for soil erosion control. The cover will harden to minimize water infiltration, wind blown dust, odor and affinity to birds, flies and other insects. The water may include tap water, landfill leachate and wastewater. The binder may include Portland cement, blended cement, cement kiln dust, class C fly ash, and/or calcium sulphate hemihydrate. The adhesion enhancing admixture includes water-dispersible polymers. The fibers may comprise shredded paper or wood or plastic fibers.

Abstract: A conformable coating for application to a soil substrate for barrier, adhesive, and planting properties includes a mixture of recycled or virgin materials, including organic fibrous material from wood based material and cotton based material, and gypsum bearing materials to which an effective amount of psyllium and its processes derivatives are added to form a solids mixture, which is diluted with an amount of water sufficient to provide a flowable consistency.

Abstract: CMC with CMDS greater than or equal to 0.76, optionally with a non-ionic co-thickener or a CMC with CMDS less than 0.75 is used as both the rheology modifier and partial clay substitute in tape joint compounds. This significant reduction of clay level is sufficient to eliminate most of the negative characteristics of clay in joint compound.

Abstract: An in situ ionic interaction between two additives, one a cationic strength enhancing additive and one an anionic crosslinking additive, is used to improve the mechanical properties of an article formed from a composite material. The composite has a discrete phase bound together with a film of the additives, such as gypsum crystals bound together by a film of substituted starch or cellulose ether.

Abstract: A mixture composition of a cellulose ether made from raw cotton linters and at least one additive is used in a ready mixed joint compound composition wherein the amount of the cellulose ether in the joint compound composition is significantly reduced. When this joint compound composition is mixed with water and applied to a substrate, the water retention, sag resistance, and workability of the wet joint compound are comparable or improved as compared to when using conventional similar cellulose ethers.

Abstract: A wall repair compound useful for filling and repairing cracks, holes, and other imperfections in a wall surface includes a conventional filler material, a conventional binder material, and a dust reducing additive which reduces the quantity of airborne dust particles generated when sanding the hardened joint compound. Airborne dust reducing additives include oils, surfactants, solvents, waxes, and other petroleum derivatives. The additive can be added to conventional ready-mixed joint compounds and to setting type joint compounds. A method of reducing the quantity of airborne dust generated when sanding a fully hardened joint compound includes mixing a sufficient quantity of the dust reducing additive with the joint compound prior to when the joint compound has been applied to the wall.

Abstract: An inorganic-organic composite comprises an inorganic phase, such as gypsum crystals, and a film forming organic phase. The film forming organic phase is selected from substituted starches having a degree of polymerization; degree of substitution and viscosity such that the substituted starches are insoluble in water during mixing but dissolve at a higher processing temperature during forming, setting or drying of the composite. Thus, excessive migration of the substitute starch is prevented and the composite is substantially strengthened.

Abstract: A method of preparing construction material systems is described. The process includes extruding a composition of construction materials and an irreversibly crosslinked cellulose derivative that is prepared by a particular process.

Abstract: The invention concerns the use of water-soluble polysaccharide derivatives as dispersing agents for mineral binder suspensions. A partially hydrolyzed cellulose containing carboxyl groups and optionally hydroxyalkyl and/or sulfate groups and/or a partially hydrolyzed amylose-rich starch which also has sulfoalkyl groups with 1 to 4 carbon atoms is used as the polysaccharide derivative. These polysaccharide derivatives have a low viscosity and an excellent plasticizing effect in mineral binder suspensions, especially in those based on cement, lime and/or gypsum.

Abstract: A novel gypsum board having antifungal properties is disclosed. The board comprises a gypsum core, front and back paper facings and an antifungal agent effective at inhibiting fungal growth. A preferred antifungal agent is cetyl pyridinium chloride. The antifungal agent can be present in the gypsum core and/or on one or both of the paper facings. In addition, the antifungal agent may be encapsulated in a material that releases the antifungal agent over time and/or upon exposure to moisture. Also disclosed are methods for preparing the aforementioned antifungal gypsum board.

Abstract: Gypsum wallboard made lighter and less dense, without sacrificing strength, by adding to the gypsum slurry used in making the board a styrene butadiene polymer latex substantially stable against divalent ions in which the styrene butadiene polymer latex substantially stable against divalent ions in which the styrene butadiene polymer includes at least 0.25 wt. % of an ionic monomer.

Abstract: An admixture comprising a nonionic water-soluble cellulose ether having an average particle size of 120-500 &mgr;m is suited for hydraulic compositions. The admixture does not form clumps even in the presence of a large amount of water. The hydraulic composition having a proper amount of the admixture added is effectively extrudable.

Abstract: The invention concerns the use of water-soluble polysaccharide derivatives as dispersing agents for mineral binder suspensions. A partially hydrolyzed cellulose containing carboxyl groups and optionally hydroxyalkyl and/or sulfate groups and/or a partially hydrolyzed amylose-rich starch which also has sulfoalkyl groups with 1 to 4 carbon atoms is used as the polysaccharide derivative. These polysaccharide derivatives have a low viscosity and an excellent plasticizing effect in mineral binder suspensions, especially in those based on cement, lime and/or gypsum.

Abstract: Methods of cementing in subterranean zones, improved cement compositions and improved additives are provided. The compositions are basically comprised of a hydraulic cement, sufficient water to form a slurry and an additive for providing improved rheology, fluid loss control and set retardation comprised of carboxymethylhydroxyethylcellulose having in the range of from about 0.62 to about 2.21 moles of hydroxyethyl substitution and in the range of from about 0.44 to about 0.52 degrees of carboxymethyl substitution and a 2% by weight aqueous solution of the carboxymethylhydroxyethylcellulose has a Höppler viscosity in the range of from about 55 mPa.s to about 359 mPa.s.