Abstract: The present invention has its object to provide a foam outstanding in electrification and heat insulating and sound insulating properties and has high compressive strength even when it has low density. The present invention relates to a foam comprising an organic polymer expanded matrix (I) and at least one kind of inorganic substance (II) selected from the group consisting of metals, metal compounds and non-metal inorganic fillers, wherein said expanded matrix (I) contains metal salt-crosslinks and the relation between the weight percentage (M) of the metal forming said metal salt-crosslinks in the expanded matrix (I) based on the total weight of the expanded matrix (I) and the inorganic substance (II) and the weight percentage (S) of the inorganic substance (II) based on the total weight of the expanded matrix (I) and the inorganic substance (II) satisfies the following expression. M≧10−S/4  (1) wherein M≦50 and S≧5.

Abstract: A foam comprising a metal salt-crosslinked cellular (co)polymer (A) obtained by polymerizing a monomer charge comprising an .alpha., .beta.-unsaturated carboxylic acid and optionally one or more other vinyl monomers, wherein at least part of said monomer charge is concurrently foamed and polymerized in the presence of a metal salt of carbonic acid, and processes for producing them. Low-density foams that are benign to the environment and can be easily produced can be provided.

Abstract: Dewatering of sludge is accomplished by adding an organic fibrous material having the bulk specific gravity increased by being pressed or being wetted with water and a high molecular weight flocculant to the sludge, adjusting the resulting flocs to a diameter of not more than 1 mm, and subjecting the flocs to vacuum or pressure filtration.

Abstract: Water-soluble copolymers of 10-30 mole % of (meth)acrylic acids, 1-10 mole % of sulfo group-containing (meth)acrylic monomers and 60-89 mole % of (meth)acrylamides, which copolymers have inherent viscosity of 10-25 dl/g, have improved mechanical shear stability and improved viscosity-increasing property even under contact with water containing impurities and are used for enhanced oil recovery.

Abstract: A water-in-oil polymer emulsion having an excellent fluidity can be obtained by a process which comprises dispersing an aqueous solution of at least one (meth)acrylic monomer containing a quaternary ammonium salt or a tertiary amine salt in a hydrophobic organic liquid in the presence of an oil-in-water type nonionic surfactant, and heating the resulting dispersion to a temperature of at least 40.degree. C. to polymerize the monomer mixture.