Abstract: A filter medium for liquid filtration of fine texture exhibiting high strength when wetted with water, which filter medium is comprised of a wet-laid nonwoven fabric. There is provided a filter medium for liquid filtration comprised of a wet-laid nonwoven fabric, characterized in that through blending of 0.5 to 40 wt. % of unbeaten natural fibers, it exhibits a very fine texture, a lowering ratio, calculated from bursting strength in ordinary state and bursting strength when wetted with water, of 30% or below, and a bursting strength, had when wetted with water, of 300 kPa or greater.

Abstract: An object of the invention is to provide a finely cut paper product exhibiting a good workability in the production of a paper-resin composition comprising a mixture of a resin and a natural fiber, and improve the fluidity of an ecologically sound paper-resin composition using the finely cut paper product, so as to improve the moldability thereof when the composition is subjected to a working such as injection molding. An other object thereof is to restrain the generation of yellowing or the generation of an odor. The finely cut paper product for use in mixing with resin according to the invention is obtained by pulverizing neutral or alkaline pigment-free coated paper which comprises 70 to 100% by mass of hardwood bleached chemical pulp, 0 to 20% by mass of softwood bleached chemical pulp and 0 to 20% by mass of an inorganic filler, and has an ISO brightness of 70% or more.

Abstract: In the process for producing kraft pulp, performing a potassium ion removal step of flowing an aqueous solution containing ashes recovered from a combustion exhaust gas generated in a black solution combustion step by a dust collector through a packed bed filled with a sodium-type cation exchange organic resin to adsorb and remove potassium ions contained in the aqueous solution; and a regeneration step of treating the cation exchange organic resin used in the potassium ion removal step with a solution consisting essentially of aqueous sodium hydroxide to regenerate the cation exchange resin, where a fraction recovered from the potassium ion removal step which is rich in sodium sulfate and sodium carbonate is recycled to the black solution concentrating step, and a sodium hydroxide effluent recovered from the regeneration step is recycled to a bleaching step and used in a bleaching process.

Abstract: A filter material take-up product and a paper winding core, which are free from secondary-contamination by an outgas while being transported or stocked. Irrespective of its application such as building air conditioner, an air cleaner or a semi-conductor factory, the amount of the outgas to be generated from the filter take-up product for the air filter can be kept at a negligible level. The filter take-up product for the air filter is produced by coating and wrapping the filter material for the air filter, as wound on the winding core, with a film wrapping material which is so made of phenolic compounds, carboxylate esters, phosphate ester or cyclic siloxance as to have an outgas generation in an amount of 100 ng/g or less by the dynamic head space method.

Abstract: It is intended to provide an air purification filter which has a high dry tensile strength, a high wet tensile strength in association with a high water resistance and a high water repellency and exhibits a bactericidal effect due to a gas phase reaction in a gas phase. Namely, an air purification filter having a high dry tensile strength, a high wet tensile strength (a high water resistance) and a high water repellency as well as a bactericidal effect which is obtained by blending a filter fiber having a functional group with a mixture of a modification enzyme which has an ionic polarity opposite to the ionic polarity of the whole filter fiber as described above and a bactericidal effect with an ionic synthetic resin binder having the opposite ionic polarity similar to the modification enzyme.

Abstract: An ink jet printing paper which has a degree of bulk equal to or higher than that of non-coated paper, retains the same quality as that of coated type sheet with respect to surface smoothness, sharpness of print images, ink absorbability and water resistance, and shows improved ink strike-through and cockling while being bulky. The ink jet printing paper has an ink receiving layer provided on the base paper with the base paper containing synthetic fiber having a branched form.

Abstract: A filter medium for an air filter, characterized in that it comprises a filter material having a glass fiber as its primary component and an alkyl ketene dimer adhered to the surface of the glass fiber; and a method for producing the filter medium which comprises a step of subjecting a dispersed slurry of a raw material fiber to a wet papermaking to form a wet paper, a step of immersing the wet paper in an aqueous dispersion or solution of the dimer or a liquid mixture of the dimer and a binder resin, or applying or spraying any of the above-mentioned liquids to the wet paper, to thereby allow the dimer to adhere onto the surface of the glass fiber, and a step of drying the resultant wet paper having the dimer adhered thereto. The filter medium exhibits a reduced amount of an out gas generated when it is used with ventilation and also exhibits high water-repellency and satisfactory strength in various applications such as air conditioning of a building and semiconductor manufacturing.

Abstract: A neutral wood containing paper can be produced by adding, to a stock slurry containing mineral filler and a large majority of high yield pulp, a cationized starch, and thereafter bentonite and colloidal silica either simultaneously or successively with a time interval of at most 60 seconds, resulting in an improved retention of fiber and filler, an improved drainage, and a decreased pitch problem.

Abstract: An aqueous dispersed solution of a substituted succinic anhydride which comprises an aqueous soluble copolymer (A) having 50 percent or more by mol of (meth)acrylamide (a) 1 percent or more by mol of N,N-dialkylamino.alkyl(meth)acrylamide (b) as monomer ingredients, aqueous soluble copolymer (B) having 50 percent or more by mol of (meth)acrylamide (a), 1 percent or more by mol of N,N-dialkylamino.alkyl(metho)acrylamide (b) and 49 percent or less by mol of other copolymer monomer (c) as monomer ingredients, or both of the dqueous soluble copolymer (A) and the aqueous soluble copolymer (B), and a process for producing an aqueous dispersed solution of a substituted succinic anhydride prepared by dispersing the aqueous soluble copolymer (A) or the aqueous soluble copolymer (B) or a mixture (C) of 99 to 99.9 percent by weight of the substituted succinic anhydride (d) and 10 to 0.

Abstract: A composition for a sizing agent comprising (a) 70-99.9 wt.% of a substituted alkyl succinic anhydride or a substituted alkenyl succinic anhydride or a mixture of these succinic anhydrides, and (b) 0.1-30 wt.% of phosphates of polyoxyethylene alkyl ether esters or phosphates of polyoxyethylene alkyl aryl ether esters of a mixture of these phosphate esters and a process for using the composition by dispersing the composition, adding the produced aqueous dispersion to pulse alurry of paper making material, and making the paper. This composition for the sizing agent has excellent storage stability and underwater self-emulsion, and accordingly exhibits an excellent sizing effect and provides paper having an excellent sizing effect.

Abstract: A composition for a sizing agent comprising (a) 70-99.9 wt. % of a substituted alkyl succinic anhydride or a substituted alkenyl succinic anhydride or a mixture of these succinic anhydrides, and (b) 0.1-30 wt. % of phosphates of polyoxyethylene alkyl ether esters or phosphates of polyoxyethylene alkyl aryl ether esters of a mixture of these phosphate esters and a process for using the composition by dispersing the composition, adding the produced aqueous dispersion to pulse slurry of paper making material, and making the paper. This composition for the sizing agent has excellent storage stability and underwater self-emulsion, and accordingly exhibits excellent sizing effect and provides paper having an excellent sizing effect.

Abstract: Static resistance of a light-sensitive silver halide photographic material is improved by treating said material with a solution or dispersion of a polymer containing quaternary ammonium groups, and which also acts as an antifoaming agent in processing solutions. The polymeric moiety of the polymer has the formula ##STR1## WHEREIN R.sub.1, R.sub.2, R.sub.3, and R.sub.4 are individually a substituted or unsubstituted alkyl group having 1 to 4 carbon atoms; A and B are individually an alkylene group having 1 to 4 carbon atoms, a hydroxymethylene group, a phenylene group or a mere bond; X.sub.1.sup..crclbar. and X.sub.2.sup..crclbar. are individually an anion; and n is an integer of 10 to 30.