A composition in accordance with an aspect of the present invention includes: composite fibers composed of inorganic particles and fibers; and at least one of (i) different-type inorganic particles which are different in type from the inorganic particles, (ii) different-type fibers which are different in type from the fibers, and (iii) organic particles.

A composition in accordance with an aspect of the present invention includes: composite fibers composed of inorganic particles and fibers; and at least one of (i) different-type inorganic particles which are different in type from the inorganic particles, (ii) different-type fibers which are different in type from the fibers, and (iii) organic particles.

Disclosed herein are processes for producing precipitated calcium carbonate. In one embodiment, the process comprises the steps of a) providing an aqueous slurry of calcium hydroxide; b) adding a polysaccharide to the slurry of calcium hydroxide; and c) carbonating the slurry of calcium hydroxide. The polysaccharide comprises poly alpha-1,3-glucan, a poly alpha-1,3-glucan ester compound as disclosed herein, or a poly alpha-1,3-glucan ether compound as disclosed herein. The precipitated calcium carbonate produced by the process can be useful in making paper.

The present invention aims to provide techniques for preparing complexes of a hydrotalcite and a fiber. The complexes of a hydrotalcite and a fiber can be synthesized efficiently by synthesizing the hydrotalcite in an aqueous system in the presence of the fiber.

The present invention aims to provide techniques for preparing complexes of a hydrotalcite and a fiber. The complexes of a hydrotalcite and a fiber can be synthesized efficiently by synthesizing the hydrotalcite in an aqueous system in the presence of the fiber.

The invention provides a method of producing a filler comprising calcium carbonate (PCC), preferably to be used in paper or paper board production or in fibre based composites. The method of the invention comprises the steps of; —providing fly ash generated in paper or paper board production; —fractionating said fly ash in at least one step, whereby a coarser fraction is separated from a finer fraction; —forming a suspension of said coarser fraction; —adding carbon dioxide to said suspension to form precipitated calcium carbonate. The method of the invention avoids problems with high amounts of arsenic and heavy metals in the production of filler comprising PCC, when using ash generated in paper or paper board production as a raw material. It has been shown that harmful elements, such as arsenic and heavy metals, are primarily accumulated in the finer fractions of the fly ash. Thus, by using the coarser fraction in the step of carbonation, the amount of arsenic and heavy metals in the final product is reduced.

The invention provides a method of producing a filler comprising calcium carbonate (PCC), preferably to be used in paper or paper board production or in fibre based composites. The method of the invention comprises the steps of; —providing fly ash generated in paper or paper board production; —fractionating said fly ash in at least one step, whereby a coarser fraction is separated from a finer fraction; —forming a suspension of said coarser fraction; —adding carbon dioxide to said suspension to form precipitated calcium carbonate. The method of the invention avoids problems with high amounts of arsenic and heavy metals in the production of filler comprising PCC, when using ash generated in paper or paper board production as a raw material. It has been shown that harmful elements, such as arsenic and heavy metals, are primarily accumulated in the finer fractions of the fly ash. Thus, by using the coarser fraction in the step of carbonation, the amount of arsenic and heavy metals in the final product is reduced.

A method comprising providing a sol comprising a solvent; contacting the sol with a precipitation initiator to initiate precipitation of the sol, wherein the precipitation initiator is different to the solvent; and applying the precipitating sol to a product. The methods of the invention may be used with sols comprising a solvent, a metal alkoxide, and optionally a biopolymer and/or a catalyst, with alkoxides comprising metals, organically modified alkoxides comprising metals, alkoxides comprising metalloids, and organically modified alkoxides comprising metalloids all being encompassed by the term ‘metal alkoxide’. Also disclosed is an apparatus for use in the method comprising a first storage vessel; a second storage vessel; one or more pumps; and one or more delivery means.

The present invention aims to provide complex fibers comprising a cellulose fiber strongly covered by a lot of inorganic particles on its surface. In the present invention, an excellent complex fiber of a cellulose fiber with inorganic particles can be prepared on the basis of the value of (D50−D10)/D50 calculated from the particle size distribution of (a) or (b) below: (a) the filtrate obtained by filtering an aqueous suspension of the complex fiber at a solids content of 0.1% through a 60-mesh sieve (having an opening of 250 μm); or (b) the fraction corresponding to an effluent volume (L) of 18.51 to 19.50 and an efflux time (sec) of 37.4 to 48.0 when an aqueous suspension of the complex fiber at a solids content of 0.3% is classified using a fiber classification analyzer under the conditions of a flow rate of 5.7 L/min, a water temperature of 25±1° C., and a total effluent volume of 22 L.

The present invention aims to provide complex fibers comprising a cellulose fiber strongly covered by a lot of inorganic particles on its surface. In the present invention, an excellent complex fiber of a cellulose fiber with inorganic particles can be prepared on the basis of the value of (D50−D10)/D50 calculated from the particle size distribution of (a) or (b) below: (a) the filtrate obtained by filtering an aqueous suspension of the complex fiber at a solids content of 0.1% through a 60-mesh sieve (having an opening of 250 μm); or (b) the fraction corresponding to an effluent volume (L) of 18.51 to 19.50 and an efflux time (sec) of 37.4 to 48.0 when an aqueous suspension of the complex fiber at a solids content of 0.3% is classified using a fiber classification analyzer under the conditions of a flow rate of 5.7 L/min, a water temperature of 25±1° C., and a total effluent volume of 22 L.