The present invention relates to a method for producing a gypsum-containing foamed prefabricated building material and to a gypsum-containing foamed prefabricated building material.

The present invention relates to a method for producing a gypsum-containing foamed prefabricated building material and to a gypsum-containing foamed prefabricated building material.

The present invention relates to a method for producing a gypsum-containing foamed prefabricated building material and to a gypsum-containing foamed prefabricated building material.

A method of making paper or paperboard using a composition made by the hydrogenation or partial hydrogenation of an alkyl ketene dimer, alkenyl ketene dimer, or ketene multimer (collectively labeled H.sub.2-AKD). Also, relates to a paper or paperboard having increased water and water vapor resistance while maintaining good recyclability and repulpability.

A method of making paper or paperboard using a composition made by the hydrogenation or partial hydrogenation of an alkyl ketene dimer, alkenyl ketene dimer, or ketene multimer (collectively labeled H.sub.2-AKD). Also, relates to a paper or paperboard having increased water and water vapor resistance while maintaining good recyclability and repulpability.

Device and method for continuously preparing high-purity AKD without solvent includes a reactor making continuous mixing of raw materials. The process includes: the tertiary amine feeding into the reactor and the continuously feeding acyl chloride from three to ten line; under operating state, the motor rotates the internal cylinder in relation to external cylinder, forcing the fed materials to convey and stir in the conveying section of annular column passage, forcing the materials to shear and mix by movement of shearing and kneading blades. Arrangement of conveying and mixing sections along the axial direction of annular column passage, causes sufficient reaction of materials and controls the material temperature through internal and external heat exchange systems until the reaction products are discharged from outlet. The device and process disperse reaction heat and sufficient material mixture and complete reaction to control the reaction temperature, viscosity and decrease the generation of side reaction.

Device and method for continuously preparing high-purity AKD without solvent includes a reactor making continuous mixing of raw materials. The process includes: the tertiary amine feeding into the reactor and the continuously feeding acyl chloride from three to ten line; under operating state, the motor rotates the internal cylinder in relation to external cylinder, forcing the fed materials to convey and stir in the conveying section of annular column passage, forcing the materials to shear and mix by movement of shearing and kneading blades. Arrangement of conveying and mixing sections along the axial direction of annular column passage, causes sufficient reaction of materials and controls the material temperature through internal and external heat exchange systems until the reaction products are discharged from outlet. The device and process disperse reaction heat and sufficient material mixture and complete reaction to control the reaction temperature, viscosity and decrease the generation of side reaction.

Device and method for continuously preparing high-purity AKD without solvent includes a reactor making continuous mixing of raw materials. The process includes: the tertiary amine feeding into the reactor and the continuously feeding acyl chloride from three to ten line; under operating state, the motor rotates the internal cylinder in relation to external cylinder, forcing the fed materials to convey and stir in the conveying section of annular column passage, forcing the materials to shear and mix by movement of shearing and kneading blades. Arrangement of conveying and mixing sections along the axial direction of annular column passage, causes sufficient reaction of materials and controls the material temperature through internal and external heat exchange systems until the reaction products are discharged from outlet. The device and process disperse reaction heat and sufficient material mixture and complete reaction to control the reaction temperature, viscosity and decrease the generation of side reaction.