A method is disclosed for producing products based on wood as a raw material. The method includes wood, in the form of wood particles, being subjected to an extraction treatment using an extracting agent. The extracting agent may include one or more organic solvents in an organic-aqueous mixture of the solvent or solvents with water. A content of fatty acids in the wood particles is reduced, by the extraction treatment of the wood particles using the solvent, by at least 70%, measured as hexanal content in wt. % after accelerated aging for 72 h at 90 C., while the content of cellulose, hemicelluloses and lignin is largely maintained during this extraction treatment.

A use of organofunctionalized mesoporous silica for the production of recycled paper; the organofunctionalized mesoporous silica comprises a base mesoporous silica having, on its surface, groups having the following general formula (I), wherein Si.sup.1 is a silicon atom of the base mesoporous silica, R.sup.1 is a C.sub.1-C.sub.5 aliphatic; R.sup.2 is chosen in the group consisting of: a C.sub.1-C.sub.5 aliphatic and an oxygen atom bound with a silicon atom of the base mesoporous silica; and R.sup.3 is chosen in the group consisting of: a hydroxyl, a C.sub.1-C.sub.5 aliphatic and an oxygen atom bound with a silicon atom of the base mesoporous silica (I).

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Provided is a method for producing paper and a pitch removal agent that can remove pitch efficiently. A pitch removal agent having an average polymerization degree of 300 to 2500, a saponification index of 70 to 88 mol % and satisfying, when the absorbance at a wavelength of 490 nm is designated as y (Abs) and the saponification index as x (mol %), the Numerical Formula (A) below is added to a pulp slurry during production of paper using waste paper in the step of deinking the waste paper by floatation and/or a step earlier:
y=0.0297x+b(A) (wherein, 70x88 and 2.80b3.03).

The invention relates to a method for producing products based on non-woody biomass as raw material, characterised in that non-woody biomass which contains cellulose, hemicelluloses and lignin and is in the form of particles is subjected to an extraction treatment with an extractant which comprises one or more organic solvents in an organic aqueous mixture of the solvent or solvents with water, wherein the content of fatty acids in the particles is reduced by the extraction treatment of the particles with the solvent by at least 70%, measured as hexanal content in wt. % after accelerated ageing for 72 hours at 90? C., but the content of cellulose, hemicelluloses and lignin is substantially preserved in this extraction treatment.

A method of forming an aqueous solution comprising mircrofibrillated cellulose, the method comprising the steps of providing a substantially dry composite material, comprising microfibrillated cellulose and a filler material, wherein said filler material is precipitated onto fibers or fibrils of said microfibrillated cellulose; providing an aqueous media, wherein the method further comprises the step of lowering the pH value of said aqueous media and then mixing said aqueous media with said substantially dry composite material, such that the filler material is released from said microfibrillated cellulose, thus dissolving said microfibrillated cellulose; or the step of mixing said aqueous media with said substantially dry composite material, and then lowering the pH of said mixture, such that the filler material is released from said microfibrillated cellulose, thus releasing said microfibrillated cellulose.

Disclosed is a pitch control agent including a (meth)acrylamide-based amphoteric polymer. The (meth)acrylamide-based amphoteric polymer contains 50 mol % or more of (meth)acrylamide, 0.5 to 20 mol % of a diallyldialkylammonium salt; and 0.1 to 14 mol % of an anionic monomer, as copolymerizable monomer components. This pitch control agent is less likely to be affected by a change in a surrounding environment, and therefore can exhibit excellent pitch controllability under various environments in paper production process.

Methods to reduce sticky and fluff induced rewinder breaks by reducing the adhesive character of adhesive materials, fluff and sticky contaminants in fibers are described. One method involves contacting the fibers with a composition containing at least one of each of a cellulase, a hemicellulase, a -glucosidase, a lipase, an esterase, a pectinase, a pectate lyase and a laccase for a sufficient time and in a sufficient amount to control the removal or controlling adhesive materials, fluff and sticky contaminants present in the fibers. Preferably, the fibers are recycled fibers originating from a variety of sources such as old corrugated containers, old newsprint, mixed office waste, and the like. Resulting paper products formed from the processed fibers are also described as well as methods to make them.

Disclosed is a pitch control agent including a (meth)acrylamide-based amphoteric polymer. The (meth)acrylamide-based amphoteric polymer contains 50 mol % or more of (meth)acrylamide, 0.5 to 20 mol % of a diallyldialkylammonium salt; and 0.1 to 14 mol % of an anionic monomer, as copolymerizable monomer components. This pitch control agent is less likely to be affected by a change in a surrounding environment, and therefore can exhibit excellent pitch controllability under various environments in paper production process.

This invention relates to a method for treating chemical paper pulp comprising a step of treating the pulp with ozone followed by a step of alkaline extraction, in which alkaline extraction takes place in the presence of magnesium ions (Mg.sup.2+).

The present invention provides a process for preparing a cellulose solution. NMMO with a relatively low concentration and non-activated pulp are continuously mixed online, the mixed premix is dewatered in evaporation dewatering equipment until an NMMO concentration suitable for swelling is achieved, then, sufficient swelling is carried out under this condition, and the uniformly-mixed and sufficiently swelled pre-swelling solution is subjected to depressurized evaporation dewatering and dissolving by thin-film-evaporation equipment thereby obtaining a high-concentration, uniformly-dissolved and excellently-uniformity cellulose solution. The present invention further provides continuous preparation equipment for the process for preparing a cellulose solution. According to the present invention, the conflict between uniform mixing and sufficient swelling during the preparation of a high-concentration cellulose solution is solved, and problems in storage and transportation safety caused by using high concentration NMMO in the conventional technologies are prevented.