WO2018097312A1

WO2018097312A1 - Composite of fiber and inorganic particles

Info

Publication number: WO2018097312A1
Application number: PCT/JP2017/042614
Authority: WO
Inventors: 直之菅原; 正淳大石; 萌渕瀬; 徹中谷; 後藤　至誠
Original assignee: 日本製紙株式会社
Priority date: 2016-11-28
Filing date: 2017-11-28
Publication date: 2018-05-31

Abstract

The present invention addresses the problem of providing products comprising a fiber composite of inorganic particles and fiber. The present invention provides products comprising a fiber composite of inorganic particles and fiber, said products being in the form of an aqueous suspension, pulp, sheet, powder, microsphere grains, granules, pellets, mold, yarn or foam.

Description

Composite of fiber and inorganic particles

The present invention relates to a product containing a composite of fibers and inorganic particles, and a method for producing the same. In particular, the present invention comprises a composite of fibers and inorganic particles and is in the form of an aqueous suspension, pulp, sheet, powder, microsphere, granule, pellet, paste, mold, yarn, or foam And a manufacturing method thereof.

In recent years, it has been found that by combining fibers and inorganic particles, a unique composite having the characteristics of both fibers and inorganic particles can be obtained.
For example, in Patent Document 1, by mixing an inorganic compound and fine fibrous cellulose, the properties of the inorganic compound (heat resistance, thermal conductivity, antibacterial property while maintaining transparency, light transmission, and light diffusibility) are disclosed. Etc.) can be provided. As for the technique for depositing inorganic particles on the fiber, Patent Document 2 describes a composite in which crystalline calcium carbonate is mechanically bonded on the fiber. Patent Document 3 describes a technique for producing a composite of pulp and calcium carbonate by precipitating calcium carbonate in a pulp suspension by a carbon dioxide method. Patent Document 4 describes a method of removing or reducing hydrogen sulfide in an absorbent product by using a particulate material attached to pulp fibers with a yield improver.

JP 2012-007247 A Japanese Patent Laid-Open No. 06-158585 US Pat. No. 5,679,220 JP-A-2005-48351

An object of the present invention is to provide a product including a composite of fibers and inorganic particles, and a method for producing the product. In particular, the present invention comprises a composite of fibers and inorganic particles and is in the form of an aqueous suspension, pulp, sheet, powder, thread, microsphere, granule, pellet, paste, mold, or foam It is an object to provide a manufacturing method thereof.

The present invention includes, but is not limited to, the following inventions.
(1) A product comprising a composite of fibers and inorganic particles and in the form of an aqueous suspension, pulp, sheet, powder, microsphere, granule, pellet, mold, thread, or foam.
(2) The product according to (1), wherein the product is an aqueous suspension.
(3) The product according to (2), wherein the water content of the aqueous suspension is 90% by mass or more and 99% by mass or less.
(4) The product according to (1), wherein the product is pulp.
(5) The product according to (4), wherein a moisture content of the pulp is 10% by mass or more and less than 90% by mass.
(6) The product according to (1), wherein the product is a sheet.
(7) The product according to (6), wherein the moisture content of the sheet is less than 10% by mass.
(8) The product according to (6) or (7), wherein the sheet is a paper containing the composite as an internal filler.
(9) The product according to (1), wherein the product is a powder.
(10) The product according to (10), wherein an average particle size of the powder is less than 100 μm.
(11) The product according to (1), wherein the product is a microspherical particle.
(12) The product according to (11), wherein an average particle diameter of the microspherical particles is 100 μm or more and less than 1000 μm.
(13) The product according to (1), wherein the product is a granule.
(14) The product according to (13), wherein an average particle diameter of the granules is 1.0 mm or more and less than 10 mm.
(15) The product according to (1), wherein the product is a pellet.
(16) The product according to (15), wherein a pellet diameter of the product is 10 mm or more and 50 mm or less.
(17) The product of claim 1, wherein the product is a mold.
(18) The product according to (17), wherein the mold has a diameter of 5 cm or more and 100 cm or less.
(19) The product according to (1), wherein the product is a yarn.
(20) The product according to (19), wherein a fiber diameter of the yarn is 1 mm or more and 10 mm or less.
(21) The product according to (1), wherein the product is a foam.
(22) The product according to (21), wherein the foam has a density of 0.01 to 0.1 g / cm ³ or less.
(23) The product according to any one of (1) to (22), wherein an average primary particle diameter of the inorganic particles is 200 nm or less.
(24) The product according to any one of (6) to (8), wherein at least a part of the inorganic particles is a metal salt of calcium, magnesium, or barium.
(25) (1) to (5), (9), wherein at least a part of the inorganic particles are metal particles containing silicic acid or an aluminum metal salt, or titanium, copper, silver, iron, manganese or zinc. ) To (23).
(26) The product according to any one of (1) to (25), wherein the fiber is a chemical fiber, a recycled fiber, or a natural fiber.
(27) The product according to (26), wherein the fiber is a cellulose fiber derived from wood.
(28) The product according to any one of (1) to (27), wherein the weight ratio of the fibers to the inorganic particles is 5/95 to 95/5.
(29) A mixture containing the product according to any one of (1) to (28).
(30) A method for producing a product containing a composite of fibers and inorganic particles,
Synthesizing inorganic particles in a solution in the presence of fibers to synthesize a composite of fibers and inorganic particles;
Adjusting the moisture content of the composite of fibers and inorganic particles,
Including the above method.
(31) A method for producing an aqueous suspension containing a composite of fibers and inorganic particles,
In the step of adjusting the moisture content of the composite of fibers and inorganic particles, the moisture content is adjusted to 90% by mass or more and 99% by mass or less.
The method according to (30).
(32) A method for producing a pulp containing a composite of fibers and inorganic particles,
In the step of adjusting the moisture of the composite of fibers and inorganic particles, the moisture content is adjusted to 10% by mass or more and less than 90% by mass;
The method according to (30).
(33) A method for producing a sheet containing a composite of fibers and inorganic particles,
In the step of adjusting the moisture in the composite of fibers and inorganic particles, the moisture content is adjusted to less than 10% by mass,
The method according to (30).
(34) A method for producing a product containing a composite of fibers and inorganic particles,
Synthesizing inorganic particles in a solution in the presence of fibers to synthesize a composite of fibers and inorganic particles;
Adjusting the particle size of the composite of fibers and inorganic particles,
Including the above method.
(35) A method for producing a powder containing a composite of fibers and inorganic particles,
In the step of adjusting the particle diameter of the composite of fibers and inorganic particles, the average particle diameter of the composite of fibers and inorganic particles is adjusted to less than 100 μm.
The method according to (34).
(36) A method for producing microspherical particles containing a composite of fibers and inorganic particles,
In the step of adjusting the particle diameter of the composite of fibers and inorganic particles, the average particle diameter of the composite of fibers and inorganic particles is adjusted to 100 μm or more and less than 1000 μm.
The method according to (34).
(37) A method for producing a granule containing a composite of fibers and inorganic particles,
In the step of adjusting the particle size of the composite of fibers and inorganic particles, the average particle size of the composite of fibers and inorganic particles is adjusted to 1.0 mm or more and less than 10 mm.
The method according to (34).
(38) A method for producing a pellet containing a composite of fibers and inorganic particles,
Synthesizing inorganic particles in a solution in the presence of fibers to synthesize a composite of fibers and inorganic particles;
A step of pelletizing a composite of fibers and inorganic particles;
Including the above method.
(39) A step of solid-liquid separation of the moisture content of the composite of fibers and inorganic particles with a solid-liquid separation device, and adjusting to 45 mass% or more and 80 mass%,
The method according to (38), comprising:
(40) A method for producing a mold containing a composite of fibers and inorganic particles,
Synthesizing inorganic particles in a solution in the presence of fibers to synthesize a composite of fibers and inorganic particles;
A step of solid-liquid separation of the moisture content of the composite of fibers and inorganic particles in a solid-liquid separator, and adjusting to 10% by mass or more and 35% by mass;
Including the above method.
(41) A method for producing a yarn containing a composite of fibers and inorganic particles,
A step of synthesizing inorganic particles in a solution in the presence of fibers to synthesize a fiber composite of fibers and inorganic particles;
A process of twisting a composite of fibers and inorganic particles,
Including the above method.
(42) slitting a sheet containing a fiber composite of inorganic fibers and fibers adjusted to a moisture content of less than 10% by mass before the step of twisting the fiber composite of inorganic fibers and inorganic particles,
The method according to (41), comprising:
(43) A method for producing a foam containing a fiber composite of fibers and inorganic particles,
A step of synthesizing inorganic particles in a solution in the presence of fibers to synthesize a fiber composite of fibers and inorganic particles;
A step of stirring the fiber composite of fibers and inorganic particles with a stirrer;
Including the above method.
(44) The method according to (43), further comprising a step of drying the foamed foam.

According to the present invention, it is possible to provide a product including a fiber composite of fibers and inorganic particles, and a manufacturing method thereof. In particular, according to the present invention, it comprises a fiber composite of fibers and inorganic particles, and is in the form of an aqueous suspension, pulp, sheet, powder, granule, microsphere, pellet, paste cake, mold, yarn, or foam. And a manufacturing method thereof.

That is, by including a fiber composite of fibers and inorganic particles, and obtaining a product in the form of an aqueous suspension, the manufacturing cost of the fiber composite of fibers and inorganic particles is low, and the manufacturing process is short, A fiber composite can be produced efficiently. In addition, by obtaining products in the form of pulp, sheets, powders, granules, microspheres, including fiber composites of fibers and inorganic particles, transfer of fiber composites of inorganic particles to other products Is easy to mix. In addition, by obtaining a product in the form of pellets, pastes, molds, threads, or foams, including a fiber composite of fibers and inorganic particles, the handling is excellent and the fiber composite of fibers and inorganic particles alone. Products with flame retardancy, opacity, radiation shielding, adsorptive properties, antibacterial properties, etc. are obtained. And a product comprising a fiber-fiber composite of fibers and inorganic particles, in the form of an aqueous suspension, pulp, sheet, powder, granule, microspherical particle, pellet, paste, mold, thread, or foam. By containing, it becomes possible to obtain a composition imparted with the function of a fiber-fiber composite of fibers and inorganic particles (such as flame retardancy and opacity, radiation shielding properties, adsorbability and antibacterial properties).

FIG. 3 is a schematic diagram showing a reaction apparatus used for production of Sample 1 in Experiment A. It is an electron micrograph of the composite_body | complex synthesize | combined in Experiment 1 (Sample 1, left: 10000 time, right: 50000 time). It is an electron micrograph of the composite_body | combination synthesize | combined in Experiment 1 (Sample 2, left: 10000 time, right: 50000 time). It is an electron micrograph of the composite_body | complex synthesize | combined in Experiment 1 (Sample 3, left: 10000 time, right: 50000 time). It is the schematic which shows the reaction apparatus used in Experiment 1 (sample 1). It is a schematic diagram which shows the ultra fine bubble generator used in Experiment 1. It is the schematic which shows the reaction apparatus used in Experiment 1 (sample 2). It is the schematic of the apparatus for manufacturing the sample 3 of Experiment 1 (P: pump). It is an external appearance photograph of the form C of Experiment 3 (left: upper surface, right: horizontal surface). It is an external appearance photograph of the form E of Experiment 3 (left: upper surface, right: horizontal surface).

The present invention relates to a product including a fiber composite of fibers and inorganic particles, and a method for producing the product. In particular, the present invention comprises a fiber composite of fibers and inorganic particles, and is in the form of an aqueous suspension, pulp, sheet, powder, granule, microsphere, pellet, paste, mold, thread, or foam. The present invention relates to a product and a manufacturing method thereof.

In the present invention, inorganic particles and fibers are formed into a fiber composite. In the present invention, the fiber composite is not simply a mixture of inorganic particles and fibers, but refers to those in which the inorganic particles are bound to the surface of the fibers by hydrogen bonds, van der Waals forces, or the like. For this reason, the inorganic particles are less likely to fall out of the fiber even by the disaggregation treatment. The strength of binding between inorganic particles and fibers in the composite can be evaluated by, for example, a numerical value such as ash yield (%, that is, ash content of the sheet ÷ ash content of the composite before disaggregation × 100). Specifically, the fiber composite is dispersed in water, adjusted to a solid content concentration of 0.2%, disaggregated for 5 minutes with a standard disintegrator specified in JIS P 8220-1: 2012, and then JIS P 8222: 1998. The ash yield when formed into a sheet using a 150 mesh wire can be used for evaluation. In a preferred embodiment, the ash yield is 20% by mass or more, and in a more preferred embodiment, the ash yield is 50% by mass or more. It is.

The fiber constituting the fiber- fiber composite is not particularly limited as long as it is a fiber. For example, natural fibers as well as regenerated fibers (semi-synthetic fibers) such as rayon and lyocell, and synthetic fibers can be used without limitation. it can. Examples of fiber raw materials include pulp fibers (wood pulp and non-wood pulp), cellulose nanofibers, bacterial cellulose, seaweed and other animal-derived cellulose, and algae. Wood pulp may be produced by pulping wood raw materials. . Wood raw materials include red pine, black pine, todomatsu, spruce, beech pine, larch, fir, tsuga, cedar, hinoki, larch, shirabe, spruce, hiba, douglas fir, hemlock, white fur, spruce, balsam fur, cedar, pine, Coniferous trees such as Merck pine, Radiata pine, etc., and mixed materials thereof, beech, hippopotamus, alder tree, oak, tab, shii, birch, broadleaf tree, poplar, tamo, dragonfly, eucalyptus, mangrove, lawan, acacia, etc. Examples are materials.

The method of pulping natural materials such as wood raw materials (woody raw materials) is not particularly limited, and examples thereof include pulping methods generally used in the paper industry. Wood pulp can be classified by pulping method, for example, chemical pulp digested by kraft method, sulfite method, soda method, polysulfide method, etc .; mechanical pulp obtained by pulping by mechanical force such as refiner, grinder; Semi-chemical pulp obtained by carrying out pulping by mechanical force after pretreatment by; waste paper pulp; deinked pulp and the like. Wood pulp may be unbleached (before bleaching) or bleached (after bleaching).

Examples of the non-wood-derived pulp include cotton, hemp, sisal hemp, manila hemp, flax, straw, bamboo, bagasse, kenaf, sugar cane, corn, rice straw, cocoon, honey and others.

The pulp fiber may be either unbeaten or beaten, and may be selected according to the physical properties of the fiber composite sheet, but it is preferable to beaten. Thereby, improvement of sheet strength and promotion of fixing of inorganic particles can be expected.

Further, these cellulose raw materials are further processed to give finely pulverized cellulose, chemically modified cellulose such as oxidized cellulose, and cellulose nanofiber: CNF (microfibrillated cellulose: MFC, TEMPO oxidized CNF, phosphate esterified CNF, carboxy Methylated CNF, mechanically ground CNF, etc.). The finely pulverized cellulose used in the present invention includes both what is generally called powdered cellulose and the above mechanically pulverized CNF. As the powdered cellulose, for example, a machined pulverized raw pulp or a bar shaft produced by a method of purifying and drying an undegraded residue obtained after acid hydrolysis, crushing and sieving Crystalline cellulose powder having a certain particle size distribution may be used, or commercially available products such as KC Flock (manufactured by Nippon Paper Industries), Theolas (manufactured by Asahi Kasei Chemicals), Avicel (manufactured by FMC), etc. Good. The degree of polymerization of cellulose in the powdered cellulose is preferably about 100 to 1500, the degree of crystallinity of the powdered cellulose by X-ray diffraction is preferably 70 to 90%, and the volume average particle size by a laser diffraction type particle size distribution analyzer. Is preferably 1 μm or less and 100 μm or less. The oxidized cellulose used in the present invention can be obtained, for example, by oxidizing in water using an oxidizing agent in the presence of a compound selected from the group consisting of N-oxyl compounds and bromides, iodides, or mixtures thereof. it can. As the cellulose nanofiber, a method of defibrating the cellulose raw material is used. As the defibrating method, for example, an aqueous suspension of chemically modified cellulose such as cellulose or oxidized cellulose is mechanically ground or beaten with a refiner, a high-pressure homogenizer, a grinder, a single or multi-screw kneader, a bead mill, or the like. A method of defibration can be used. Cellulose nanofibers may be produced by combining one or more of the above methods. The fiber diameter of the produced cellulose nanofibers can be confirmed by observation with an electron microscope or the like, and is, for example, in the range of 5 nm to 1000 nm, preferably 5 nm to 500 nm, more preferably 5 nm to 300 nm. When producing the cellulose nanofiber, before and / or after the cellulose is defibrated and / or refined, an arbitrary compound may be further added and reacted with the cellulose nanofiber to modify the hydroxyl group. it can. As functional groups to be modified, acetyl group, ester group, ether group, ketone group, formyl group, benzoyl group, acetal, hemiacetal, oxime, isonitrile, allene, thiol group, urea group, cyano group, nitro group, azo group , Aryl group, aralkyl group, amino group, amide group, imide group, acryloyl group, methacryloyl group, propionyl group, propioyl group, butyryl group, 2-butyryl group, pentanoyl group, hexanoyl group, heptanoyl group, octanoyl group, nonanoyl group , Decanoyl group, undecanoyl group, dodecanoyl group, myristoyl group, palmitoyl group, stearoyl group, pivaloyl group, benzoyl group, naphthoyl group, nicotinoyl group, isonicotinoyl group, furoyl group, cinnamoyl group, 2-methacryloyl group, etc. Isocyanate groups such as oxyethylisocyanoyl group, methyl group, ethyl group, propyl group, 2-propyl group, butyl group, 2-butyl group, tert-butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl Group, decyl group, undecyl group, dodecyl group, myristyl group, palmityl group, stearyl group and other alkyl groups, oxirane group, oxetane group, oxyl group, thiirane group, thietane group and the like. Hydrogen in these substituents may be substituted with a functional group such as a hydroxyl group or a carboxy group. Further, a part of the alkyl group may be an unsaturated bond. The compound used for introducing these functional groups is not particularly limited. For example, a compound having a phosphoric acid-derived group, a compound having a carboxylic acid-derived group, a compound having a sulfuric acid-derived group, or a sulfonic acid-derived compound And the like, compounds having an alkyl group, compounds having an amine-derived group, and the like. Although it does not specifically limit as a compound which has a phosphoric acid group, Lithium dihydrogen phosphate which is phosphoric acid and the lithium salt of phosphoric acid, Dilithium hydrogen phosphate, Trilithium phosphate, Lithium pyrophosphate, Lithium polyphosphate is mentioned. . Furthermore, sodium dihydrogen phosphate, disodium hydrogen phosphate, trisodium phosphate, sodium pyrophosphate and sodium polyphosphate which are sodium salts of phosphoric acid are mentioned. Furthermore, potassium dihydrogen phosphate, dipotassium hydrogen phosphate, tripotassium phosphate, potassium pyrophosphate, and potassium polyphosphate which are potassium salts of phosphoric acid are mentioned. Further, ammonium dihydrogen phosphate, diammonium hydrogen phosphate, triammonium phosphate, ammonium pyrophosphate, and ammonium polyphosphate which are ammonium salts of phosphoric acid are included. Of these, phosphoric acid, sodium phosphate, phosphoric acid potassium salt, and phosphoric acid ammonium salt are preferred from the viewpoint of high efficiency in introducing a phosphate group and easy industrial application. Sodium dihydrogen phosphate Although disodium hydrogen phosphate is more preferable, it is not particularly limited. The compound having a carboxyl group is not particularly limited, and examples thereof include dicarboxylic acid compounds such as maleic acid, succinic acid, phthalic acid, fumaric acid, glutaric acid, adipic acid and itaconic acid, and tricarboxylic acid compounds such as citric acid and aconitic acid. . The acid anhydride of the compound having a carboxyl group is not particularly limited, but examples thereof include acid anhydrides of dicarboxylic acid compounds such as maleic anhydride, succinic anhydride, phthalic anhydride, glutaric anhydride, adipic anhydride, and itaconic anhydride. It is done. Although it does not specifically limit as a derivative of the compound which has a carboxyl group, The derivative of the acid anhydride of the compound which has a carboxyl group and the acid anhydride imidation of a compound which has a carboxyl group are mentioned. Although it does not specifically limit as an acid anhydride imidation thing of a compound which has a carboxyl group, Imidation thing of dicarboxylic acid compounds, such as maleimide, succinic acid imide, and phthalic acid imide, is mentioned. The acid anhydride derivative of the compound having a carboxyl group is not particularly limited. For example, at least some of the hydrogen atoms of the acid anhydride of the compound having a carboxyl group, such as dimethylmaleic anhydride, diethylmaleic anhydride, diphenylmaleic anhydride, etc. are substituted (for example, alkyl group, phenyl group, etc. ) Are substituted. Among the compounds having a group derived from a carboxylic acid, maleic anhydride, succinic anhydride, and phthalic anhydride are preferred because they are easily applied industrially and easily gasified, but are not particularly limited. Further, the cellulose nanofiber may be modified in such a manner that the compound to be modified is physically adsorbed on the cellulose nanofiber without being chemically bonded. Examples of the physically adsorbing compound include surfactants, and any of anionic, cationic, and nonionic may be used. When the above-described modification is performed before cellulose is defibrated and / or pulverized, these functional groups can be removed after defibrating and / or pulverization to return to the original hydroxyl group. By performing the modification as described above, it is possible to promote the defibration of the cellulose nanofiber or to easily mix it with various substances when the cellulose nanofiber is used.

A composite fiber of synthetic fiber and fiber can also be used in the present invention. For example, a composite fiber of polyester, polyamide, polyolefin, acrylic fiber, glass fiber, carbon fiber, various metal fibers and the like can also be used. it can.

The fibers shown above may be used alone or in combination. Especially, it is preferable that wood pulp is included or the combination of wood pulp, non-wood pulp, and / or synthetic fiber is included, and it is more preferable that it is only wood pulp.

In a preferred embodiment, the fibers constituting the fiber composite of the present invention are cellulose fibers or pulp fibers. Further, for example, a fibrous substance recovered from the wastewater of a paper mill may be supplied to the carbonation reaction of the present invention. By supplying such a substance to the reaction vessel, various composite particles can be synthesized, and fibrous particles and the like can be synthesized in terms of shape.

In the present invention, in addition to the fiber, a substance that is not directly involved in the carbonation reaction but is taken into the product inorganic particles to form composite particles can be used. In the present invention, fibers such as pulp fibers are used, but these substances are further incorporated by synthesizing inorganic particles in a solution containing inorganic particles, organic particles, polymers and the like. Composite particles can be produced.

The fiber length of the fiber to be combined is not particularly limited. For example, the average fiber length may be about 0.1 μm to 15 mm, and may be 1 μm to 12 mm, 100 μm to 10 mm, 500 μm to 8 mm, and the like.

Inorganic particles In the present invention, the inorganic particles to be combined with the fiber are not particularly limited, but are preferably inorganic particles that are insoluble or hardly soluble in water. Since the inorganic particles may be synthesized in an aqueous system and the fiber composite may be used in an aqueous system, the inorganic particles are preferably insoluble or hardly soluble in water.

The inorganic particle said here means a metal or a metal compound. The metal compound is a metal cation (for example, Na ⁺ , Ca ²⁺ , Mg ²⁺ , Al ³⁺ , Ba ²⁺ ) and an anion (for example, O ²⁻ , OH ⁻ , CO ₃ ²⁻ , PO ₄ ^{3). -} , SO ₄ ²⁻ , NO ₃ −, Si ₂ O ₃ ²⁻ , SiO ₃ ²⁻ , Cl ⁻ , F ⁻ , S ^2−, etc.), which are generally called inorganic salts Say. In the present invention, at least a part of the inorganic particles is a metal salt of calcium, magnesium or barium, or at least a part of the inorganic particles is a metal salt of silicic acid or aluminum, or titanium, copper, silver, iron, manganese Or it is preferable that it is a metal particle containing zinc.

These inorganic particles can be synthesized by a known method, which may be either a gas-liquid method or a liquid-liquid method. An example of the gas-liquid method is a carbon dioxide gas method. For example, magnesium carbonate can be synthesized by reacting magnesium hydroxide and carbon dioxide gas. Examples of liquid-liquid methods include reacting an acid (hydrochloric acid, sulfuric acid, etc.) and a base (sodium hydroxide, potassium hydroxide, etc.) by neutralization, reacting an inorganic salt with an acid or base, And a method of reacting the For example, barium sulfate and sulfuric acid are reacted to obtain barium sulfate, aluminum sulfate and sodium hydroxide are reacted to obtain aluminum hydroxide, or calcium carbonate and aluminum sulfate are reacted to produce calcium and aluminum. Composite inorganic particles can be obtained. In addition, when synthesizing inorganic particles in this manner, any metal or metal compound can be allowed to coexist in the reaction solution. In this case, these metals or metal compounds are efficiently incorporated into the inorganic particles and are combined. Can be For example, when phosphoric acid is added to calcium carbonate to synthesize calcium phosphate, composite particles of calcium phosphate and titanium can be obtained by allowing titanium dioxide to coexist in the reaction solution.

In the case of synthesizing calcium carbonate, for example, calcium carbonate can be synthesized by a carbon dioxide method, a soluble salt reaction method, a lime / soda method, a soda method, etc. In a preferred embodiment, calcium carbonate can be synthesized by a carbon dioxide method. Synthesize.

In general, when calcium carbonate is produced by the carbon dioxide method, lime is used as a calcium source, water is added to quick lime CaO to obtain slaked lime Ca (OH) 2, and carbon dioxide CO 2 is added to the slaked lime. Calcium carbonate is synthesized by the carbonation step of blowing to obtain calcium carbonate CaCO3. At this time, a slaked lime suspension prepared by adding water to quick lime may be passed through a screen to remove low-solubility lime particles contained in the suspension. Further, slaked lime may be directly used as a calcium source. In the present invention, when calcium carbonate is synthesized by the carbon dioxide method, the carbonation reaction may be performed in the presence of cavitation bubbles.

Generally, a gas blowing type carbonator and a mechanical stirring type carbonator are known as reaction vessels (carbonation reactor: carbonator) for producing calcium carbonate by the carbon dioxide method. In a gas blowing type carbonator, carbon dioxide gas is blown into a carbonation reaction tank containing slaked lime suspension (lime milk) to react slaked lime with carbon dioxide gas. Is difficult to control uniformly and finely, and is limited in terms of reaction efficiency. On the other hand, in the mechanical agitator type carbonator, a stirrer is provided inside the carbonator, and carbon dioxide gas is introduced near the stirrer to make the carbon dioxide gas fine bubbles, improving the reaction efficiency between slaked lime and carbon dioxide gas. (“Cement, Gypsum, Lime Handbook”, Gihodo Publishing, 1995, 495 pages).

However, when stirring with a stirrer provided inside the carbonation reaction tank, such as a mechanical stirring type carbonator, if the concentration of the reaction liquid is high or the carbonation reaction proceeds, the resistance of the reaction liquid is large and it is difficult to sufficiently stir Therefore, it is difficult to precisely control the carbonation reaction, and in order to perform sufficient stirring, a considerable load is applied to the stirrer, which may be disadvantageous in terms of energy. In addition, the gas inlet is located at the bottom of the carbonator, and the blades of the stirrer are installed near the bottom of the carbonator to improve the stirring. Lime screen residue with low solubility is always settled at the bottom due to fast sedimentation, which may block the gas blowing port or break the balance of the stirrer. Furthermore, in the conventional method, in addition to the carbonator, a stirrer and equipment for introducing carbon dioxide into the carbonator are necessary, and the equipment is also expensive. In the mechanical stirring type carbonator, the carbon dioxide gas supplied near the stirrer is refined by the stirrer to improve the reaction efficiency between slaked lime and carbon dioxide gas. However, when the concentration of the reaction liquid is high, the carbon dioxide gas is sufficient. In view of the carbonation reaction, it is sometimes difficult to accurately control the form of calcium carbonate produced. In the present invention, by synthesizing calcium carbonate in the presence of cavitation bubbles, it becomes possible to efficiently advance the carbonation reaction and produce uniform calcium carbonate fine particles. In particular, by using jet cavitation, sufficient stirring can be performed without a mechanical stirrer such as a blade. In the present invention, conventionally known reaction vessels can be used, and of course, the above-described gas blowing type carbonator and mechanical stirring type carbonator can be used without any problem. You may combine jet cavitation using.

When calcium carbonate is synthesized by the carbon dioxide method, the solid content concentration of the aqueous suspension of slaked lime is preferably 0.1 to 40% by weight, more preferably 0.5 to 30% by weight, and still more preferably 1 to 20%. It is about wt%. If the solid content concentration is low, the reaction efficiency is low and the production cost is high. If the solid content concentration is too high, the fluidity is deteriorated and the reaction efficiency is lowered. In the present invention, since calcium carbonate is synthesized in the presence of cavitation bubbles, the reaction solution and carbon dioxide can be suitably mixed even when a suspension (slurry) having a high solid content is used.

As an aqueous suspension containing slaked lime, those generally used for calcium carbonate synthesis can be used, for example, prepared by mixing slaked lime with water, or slaked (digested) quick lime (calcium oxide) with water. Can be prepared. There are no particular restrictions on the conditions for the soaking, but for example, the concentration of CaO can be 0.1 wt% or more, preferably 1 wt% or more, and the temperature can be 20 to 100 ° C., preferably 30 to 100 ° C. . Further, the average residence time in the soaking reaction tank (slaker) is not particularly limited, but can be, for example, 5 minutes to 5 hours, and preferably 2 hours or less. Of course, the slaker may be batch or continuous. In the present invention, the carbonation reaction tank (carbonator) and the decontamination reaction tank (slaker) may be separated, and one reaction tank may be used as the carbonation reaction tank and the decontamination reaction tank. Good.

In the case of synthesizing magnesium carbonate, the method for synthesizing magnesium carbonate can be a known method. For example, magnesium bicarbonate can be synthesized from magnesium hydroxide and carbon dioxide, and basic magnesium carbonate can be synthesized from magnesium bicarbonate via normal magnesium carbonate. Magnesium carbonate can obtain magnesium bicarbonate, normal magnesium carbonate, basic magnesium carbonate, and the like by a synthesis method, but it is particularly preferable that the magnesium carbonate according to the fiber composite of the present invention is basic magnesium carbonate. This is because magnesium bicarbonate is relatively low in stability, and normal magnesium carbonate, which is a columnar (needle-like) crystal, may be difficult to fix to the fiber. On the other hand, a fiber composite of magnesium carbonate and fibers in which the fiber surface is coated in a scale or the like can be obtained by chemical reaction to basic magnesium carbonate in the presence of fibers.

In the present invention, the reaction solution in the reaction vessel can be circulated for use. By circulating the reaction solution in this manner and increasing the contact between the reaction solution and carbon dioxide, the reaction efficiency can be increased and desired inorganic particles can be easily obtained.

In the present invention, a gas such as carbon dioxide (carbon dioxide) is blown into the reaction vessel and can be mixed with the reaction solution. According to the present invention, carbon dioxide gas can be supplied to the reaction liquid without a gas supply device such as a fan or a blower, and the reaction can be efficiently performed because the carbon dioxide gas is refined by cavitation bubbles. .

In the present invention, the carbon dioxide concentration of the gas containing carbon dioxide is not particularly limited, but a higher carbon dioxide concentration is preferable. The amount of carbon dioxide introduced into the injector is not limited and can be appropriately selected. For example, it is preferable to use carbon dioxide at a flow rate of 100 to 10,000 L / hour per kg of slaked lime.

The gas containing carbon dioxide of the present invention may be substantially pure carbon dioxide gas or a mixture with other gas. For example, in addition to carbon dioxide gas, a gas containing an inert gas such as air or nitrogen can be used as a gas containing carbon dioxide. Further, as the gas containing carbon dioxide, in addition to carbon dioxide gas (carbon dioxide gas), exhaust gas discharged from an incinerator of a paper mill, a coal boiler, a heavy oil boiler, or the like can be suitably used as the carbon dioxide-containing gas. In addition, a carbonation reaction can also be performed using carbon dioxide generated from the lime baking step.

When synthesizing the barium sulfate (BaSO _4), an ionic crystalline compound consisting of barium ions and sulfate ion represented by barium sulfate (BaSO _4), often at plate-like or columnar form, in water Is sparingly soluble. Pure barium sulfate is a colorless crystal, but when it contains impurities such as iron, manganese, strontium and calcium, it becomes yellowish brown or blackish gray and becomes translucent. Although it can be obtained as a natural mineral, it can also be synthesized by chemical reaction. In particular, synthetic products by chemical reaction are used not only for pharmaceuticals (X-ray contrast media) but also widely used in paints, plastics, storage batteries, etc. by applying chemically stable properties.

When synthesizing hydrotalcite, the hydrotalcite synthesis method can be a known method. For example, the fibers are immersed in an aqueous carbonate solution containing carbonate ions constituting the intermediate layer and an alkaline solution (such as sodium hydroxide) in the reaction vessel, and then an acid solution (divalent metal ions and trivalent ions constituting the basic layer). Hydrotalcite is synthesized by adding a metal salt aqueous solution containing metal ions and controlling the temperature, pH, etc., and coprecipitation reaction. Further, in the reaction vessel, the fiber is immersed in an acid solution (metal salt aqueous solution containing divalent metal ions and trivalent metal ions constituting the basic layer), and then carbonate aqueous solution containing carbonate ions constituting the intermediate layer. Hydrotalcite can also be synthesized by dropwise addition of an alkaline solution (such as sodium hydroxide) and controlling the temperature, pH, etc. and coprecipitation reaction. Although reaction at normal pressure is common, there is also a method obtained by hydrothermal reaction using an autoclave or the like (Japanese Patent Laid-Open No. 60-6619).

In the present invention, magnesium, zinc, barium, calcium, iron, copper, cobalt, nickel, manganese chlorides, sulfides, nitrates and sulfates are used as the source of divalent metal ions constituting the basic layer. Can be used. In addition, various chlorides, sulfides, nitrates, and sulfates of aluminum, iron, chromium, and gallium can be used as a supply source of trivalent metal ions constituting the basic layer.

In the present invention, carbonate ions, nitrate ions, chloride ions, sulfate ions, phosphate ions and the like can be used as anions as interlayer anions. When carbonate ions are used as interlayer anions, sodium carbonate is used as the source. However, sodium carbonate can be replaced with a gas containing carbon dioxide (carbon dioxide gas), and may be a substantially pure carbon dioxide gas or a mixture with other gases. For example, exhaust gas discharged from an incinerator, a coal boiler, a heavy oil boiler or the like of a paper mill can be suitably used as the carbon dioxide-containing gas. In addition, a carbonation reaction can also be performed using carbon dioxide generated from the lime baking step.

Synthesis of Fiber Composite The fiber composite of the present invention can be obtained by synthesizing inorganic particles in the presence of fibers. This is because the fiber surface is a suitable place for the precipitation of inorganic particles, so that it is easy to synthesize a fiber composite of inorganic particles and fibers.

The method for synthesizing a fiber composite according to the present invention essentially synthesizes inorganic particles in a solution containing fibers. For example, a fiber composite may be synthesized by stirring and mixing a solution containing a precursor of fibers and inorganic particles in an open reaction vessel, or an aqueous suspension containing a precursor of fibers and inorganic particles. You may synthesize | combine by injecting in a reaction container. When an aqueous suspension of an inorganic precursor is injected into a reaction vessel, cavitation bubbles may be generated and inorganic particles may be synthesized in the presence thereof.

When one of the precursors of the inorganic particles is alkaline, the fibers can be swollen if the fibers are dispersed in the alkaline precursor solution in advance, so that a fiber composite of inorganic particles and fibers can be obtained efficiently. . Although the reaction can be started after promoting the swelling of the fibers by stirring for 15 minutes or more after mixing, the reaction may be started immediately after mixing. In addition, when a substance that easily interacts with cellulose, such as aluminum sulfate (sulfuric acid band, polyaluminum chloride, etc.) is used as part of the precursor of inorganic particles, the aluminum sulfate side should be mixed with the fiber in advance. In some cases, the proportion of the inorganic particles fixed to the fibers can be improved.

In the present invention, the liquid may be ejected under conditions that cause cavitation bubbles in the reaction vessel, or may be ejected under conditions that do not cause cavitation bubbles. The reaction vessel is preferably a pressure vessel in any case. In addition, the pressure vessel in this invention is a container which can apply the pressure of 0.005 Mpa or more. In the condition that does not generate cavitation bubbles, the pressure in the pressure vessel is preferably 0.005 MPa to 0.9 MPa in static pressure.

As one preferred embodiment, the average primary particle diameter of the inorganic particles in the fiber composite of the present invention can be, for example, 1 μm or less, but the average primary particle diameter is 500 nm or less, and the average primary particle diameter is 200 nm. The following inorganic particles, inorganic particles having an average primary particle diameter of 100 nm or less, and inorganic particles having an average primary particle diameter of 50 nm or less can be used. Moreover, the average primary particle diameter of the inorganic particles can be 10 nm or more. The average primary particle size can be measured with a laser diffraction particle size distribution measuring device or an electron micrograph.

When manufacturing the fiber composite of the present invention, various known auxiliary agents can be further added. For example, chelating agents can be added. Specifically, polyhydroxycarboxylic acids such as citric acid, malic acid and tartaric acid, dicarboxylic acids such as oxalic acid, sugar acids such as gluconic acid, iminodiacetic acid, ethylenediaminetetra Aminopolycarboxylic acids such as acetic acid and their alkali metal salts, alkali metal salts of polyphosphoric acid such as hexametaphosphoric acid and tripolyphosphoric acid, amino acids such as glutamic acid and aspartic acid and their alkali metal salts, acetylacetone, methyl acetoacetate, acetoacetic acid Examples include ketones such as allyl, saccharides such as sucrose, and polyols such as sorbitol. In addition, as surface treatment agents, saturated fatty acids such as palmitic acid and stearic acid, unsaturated fatty acids such as oleic acid and linoleic acid, resin acids such as alicyclic carboxylic acid and abietic acid, salts, esters and ethers thereof, alcohols Activators, sorbitan fatty acid esters, amide or amine surfactants, polyoxyalkylene alkyl ethers, polyoxyethylene nonyl phenyl ether, sodium alpha olefin sulfonate, long chain alkyl amino acids, amine oxides, alkyl amines, fourth A quaternary ammonium salt, aminocarboxylic acid, phosphonic acid, polyvalent carboxylic acid, condensed phosphoric acid and the like can be added. Moreover, a dispersing agent can also be used as needed. Examples of the dispersant include sodium polyacrylate, sucrose fatty acid ester, glycerin fatty acid ester, acrylic acid-maleic acid copolymer ammonium salt, methacrylic acid-naphthoxypolyethylene glycol acrylate copolymer, methacrylic acid-polyethylene glycol. Examples include monomethacrylate copolymer ammonium salts and polyethylene glycol monoacrylate. These can be used alone or in combination. The timing of addition may be before or after the synthesis reaction. Such additives can be added in an amount of preferably 0.001 to 20%, more preferably 0.1 to 10% with respect to the inorganic particles.

In the present invention, when the fiber composite is synthesized, the reaction conditions are not particularly limited, and can be appropriately set according to the application. For example, the temperature of the synthesis reaction can be 0 to 90 ° C., preferably 10 to 80 ° C., more preferably 50 to 70 ° C., and particularly preferably about 60 ° C. The reaction temperature can be controlled by a temperature controller, and if the temperature is low, the reaction efficiency decreases and the cost increases, whereas if it exceeds 90 ° C., coarse inorganic particles tend to increase.

In the present invention, the reaction can be a batch reaction or a continuous reaction. In general, it is preferable to perform a batch reaction step for the convenience of discharging the residue after the reaction. The scale of the reaction is not particularly limited, but the reaction may be performed on a scale of 100 L or less, or may be performed on a scale of more than 100 L. The size of the reaction vessel can be, for example, about 10 L to 100 L, or about 100 L to 1000 L.

Furthermore, the reaction can be controlled, for example, by monitoring the pH of the reaction solution. According to the pH profile of the reaction solution, for example, if it is a carbonation reaction of calcium carbonate, the reaction solution is less than pH 9, preferably less than pH 8, More preferably, the reaction can be performed until the pH reaches around 7.

On the other hand, the reaction can be controlled by monitoring the conductivity of the reaction solution. If it is a carbonation reaction of calcium carbonate, for example, it is preferable to carry out the carbonation reaction until the conductivity is reduced to 1 mS / cm or less.

Furthermore, the reaction can be controlled simply by the reaction time, and specifically, it can be controlled by adjusting the time that the reactants stay in the reaction tank. In addition, in this invention, reaction can also be controlled by stirring the reaction liquid of a reaction tank or making reaction multistage reaction.

The weight ratio of the fibers to the inorganic particles can be 5/95 to 95/5, and can be 10/90 to 90/10, 20/80 to 80/20, 30/70 to 70/30, 40/60 to It may be 60/40.

In the present invention, since the fiber composite as a reaction product is obtained as a suspension, it is stored in a storage tank or subjected to treatments such as concentration, dehydration, pulverization, classification, aging, and dispersion as necessary. be able to. These can be performed by known processes, and may be appropriately determined in consideration of the application and energy efficiency. For example, the concentration / dehydration treatment is performed using a centrifugal dehydrator, a sedimentation concentrator, or the like. Examples of the centrifugal dehydrator include a decanter and a screw decanter. When using a filter or a dehydrator, the type is not particularly limited and a general one can be used. For example, a pressure-type dehydrator such as a filter press, a drum filter, a belt press, a tube press, A calcium carbonate cake can be obtained by suitably using a vacuum drum dehydrator such as an Oliver filter. For grinding, ball mill, sand grinder mill, impact mill, high-pressure homogenizer, low-pressure homogenizer, dyno mill, ultrasonic mill, kanda grinder, attritor, stone mill, vibration mill, cutter mill, jet mill, breaker, beater Short shaft extruder, twin screw extruder, ultrasonic stirrer, household juicer mixer and the like. Examples of the classification method include a sieve such as a mesh, an outward type or inward type slit or round hole screen, a vibrating screen, a heavy foreign matter cleaner, a lightweight foreign matter cleaner, a reverse cleaner, a sieving tester, and the like. Examples of the dispersion method include a high-speed disperser and a low-speed kneader.

The fiber composite obtained according to the present invention can be blended into a filler or pigment in a suspension state without being completely dehydrated, but can also be dried into a powder. Although there is no restriction | limiting in particular also about the dryer in this case, For example, an airflow dryer, a band dryer, a spray dryer etc. can be used conveniently.

In the present invention, water is used for the preparation of the suspension. As this water, normal tap water, industrial water, ground water, well water, etc. can be used, ion-exchanged water, distilled water, Pure water, industrial waste water, and water obtained during the production process can be suitably used.

The fiber composite obtained by the present invention can be modified by a known method. For example, in an embodiment, the surface can be hydrophobized to improve miscibility with a resin or the like.

In the fiber composite of the fiber according to the present invention, 15% or more of the fiber surface is coated with inorganic particles, and when the fiber surface is coated with such an area ratio, characteristics due to the inorganic particles are greatly generated. On the other hand, the characteristic attributed to the fiber surface is reduced.

The fiber composite of the fiber and inorganic particles of the present invention is not simply a mixture of fibers and inorganic particles, but the fibers and inorganic particles are bound to some extent by hydrogen bonding or the like. Is less likely to fall off. The binding strength between fibers and inorganic particles in the fiber composite can be evaluated by, for example, a numerical value such as ash yield (%), that is, (sheet ash content ÷ fiber composite ash content before disaggregation) × 100. it can. Specifically, the fiber composite is dispersed in water, adjusted to a solid content concentration of 0.2%, disaggregated for 5 minutes with a standard disintegrator specified in JIS P 8220-1: 2012, and then JIS P 8222: 1998. The ash yield when formed into a sheet using a 150 mesh wire can be used for evaluation. In a preferred embodiment, the ash yield is 20% by mass or more, and in a more preferred embodiment, the ash yield is 50% by mass or more. It is.

Form of fiber composite The present invention includes a fiber composite of fibers and inorganic particles, and is in the form of an aqueous suspension, pulp, sheet, powder, microsphere, granule, pellet, mold, thread, or foam. Used.

In the present invention, the aqueous suspension is a mixture of a liquid and a solid and has a moisture content of 90% by mass to 99% by mass. Pulp is a mixture of a liquid and a solid, having a moisture content lower than that of an aqueous suspension, and having a moisture content of 10% by mass or more and 90% by mass. The sheet refers to a thin and wide sheet, and a sheet having a moisture content of less than 10% by mass. In addition, a moisture content can be calculated | required with a following formula.

Moisture content (%) = (weight before drying (g) −weight after drying (g)) / weight after drying (g) × 100 In the present invention, a powder is a collection of powder, particles, etc. The average particle size is less than 100 μm. The microspherical particles are particles obtained by forming a fiber composite into a spherical shape, and mean particles having an average particle diameter of 100 μm or more and less than 1000 μm. The granule means a particle having a particle size larger than that of the powder and has an average particle size of 1 mm or more and less than 10 mm.

“Pellets” refer to small-size compacts obtained by compression molding of fiber composites.

“Mold” refers to a molded body obtained by pouring a fiber composite of fibers and inorganic particles into a mold and dehydrating it.

Thread refers to a thread-like thread processed from a fiber composite. Examples of yarn processing include fiber making yarn. Textile yarn refers to yarn made from paper. Specifically, it refers to a piece of paper that has been made and wound on a roll into a piece of tape of about 1 to 30 mm that is twisted into a thread. As other means of yarn processing, the yarn can be produced by spinning, extruding from a fine hole to produce a continuous yarn, drawing, or heat processing.

“Foam” refers to a fiber composite containing bubbles.

In that case, as one preferred embodiment, a product including a fiber composite of fibers and inorganic particles is a process of synthesizing inorganic particles in a solution in the presence of fibers, and synthesizing a fiber composite of fibers and inorganic particles. The method of adjusting the water | moisture content of the fiber composite of a fiber and an inorganic particle can be manufactured by the method of including. Moreover, in one aspect of this invention, a foam can also be formed by adding a cellulose nanofiber to the slurry containing the composite_body | complex of an inorganic particle and a fiber, and stirring using a stirring apparatus. At that time, the foam obtained from the slurry of the composite of calcium carbonate and fiber has a higher viscosity and is easier to handle than the foam obtained from the composite of other inorganic particles.

The stirring speed for foaming is not particularly limited, but is preferably 1000 to 10000 rpm, more preferably 2000 to 9000 rpm, and further preferably 4000 to 7000 rpm.

The stirring device used in the present invention is preferably compatible with high-speed stirring. For example, the shape of the stirring blade is preferably a set of three. As a preferable stirring device, for example, a disperser such as a multidisperser PB95 (manufactured by SMT) can be used.

In another aspect, in the present invention, foam can be formed using an extruder or the like. That is, the kneaded material can be extruded to the outside from the nozzle of the extrusion die, and water can be evaporated under atmospheric pressure to foam the material.

In the present invention, a foam having a desired shape can be produced by using a mold (mold), and various kinds of foams can be obtained by converging them into a desired shape before the foamed bubbles are solidified. Shaped foams can also be produced.

In the present invention, the formed foam is dried to produce a foam (foam). The drying temperature is, for example, 50 to 150 ° C., more preferably 70 to 130 ° C., and further preferably 90 to 110 ° C. is there.

In a preferred embodiment of the present invention, foaming can be facilitated by adding a surfactant to the slurry containing the composite. As the surfactant to be used, any of cationic, anionic and nonionic surfactants may be used. Among these, it is preferable to use an anionic surfactant.

In the foam of the present invention, for example, light calcium carbonate or heavy calcium carbonate can be blended as inorganic powder, and the particle shape of the powder can be a regular shape such as a spherical shape, an irregular shape, a whisker shape, or the like. Either may be sufficient. The average particle size is not particularly limited, but may be 0.5 to 5 μm, for example. As the calcium carbonate, it is possible to use a surface treated with a fatty acid such as stearic acid, palmitic acid or lauric acid, or a salt of these fatty acids with an alkali metal.

In the present invention, in order to improve the yield of fine fibers and inorganic content (ash), a papermaking yield may be added to the slurry containing the composite. It is also possible to improve foam stability and foam strength by adding a retention agent. The retention agent used may be either positive or negative in surface charge, but more preferably has a positive surface charge. For example, Hymo Lock ND-300 (manufactured by Hymo Co., Ltd.).

In a preferred embodiment of the present invention, a paper strength improver can be blended with the slurry containing the composite. The paper strength improver used in the present invention may be, for example, a wet paper strength agent, a dry paper strength agent, etc., for example, WS-2024 (manufactured by Seiko PMC Co., Ltd.) Hermide C-10 (manufactured by Harima Chemicals Group Co., Ltd.) can be mentioned as a power agent. Of these, wet paper strength agents are preferred. As the paper strength improver, for example, hydrophilic polymer materials such as starch, pectin, guar gum, gum arabic and alginic acid can be preferably used.

Also, the foam of the present invention can be blended with a resin such as polyolefin resin or vinyl chloride resin. For example, polypropylene or polyethylene can be used as the polyolefin resin, and a recycled polyolefin resin can also be used in consideration of cost and recycling. As the vinyl chloride resin, low-polymerization degree PVC, high-polymerization degree PVC or the like can be suitably used, and not only virgin resin but also recycled resin (soft vinyl chloride resin etc.) may be used. Furthermore, you may mix | blend a plasticizer with the foam of this invention. As the plasticizer, for example, phthalate plasticizers, trimellitate plasticizers, fatty acid plasticizers, epoxy plasticizers, adipate plasticizers, polyester plasticizers, and the like can be preferably used.

In the step of adjusting the water content of the fiber composite of fiber and inorganic particles, a centrifugal dehydrator, a sedimentation concentrator, a solid-liquid separation device, or the like is used as a device for adjusting the water. Examples of solid-liquid separators include decanters, screw decanters, disk filters, DNT washers, FUNDABAC filters, nip washers, suction filters, etc., filter presses, compact washers, drum filters, belt presses, tube presses, etc. Or a vacuum drum dehydrator such as an oliver filter can be used.

Obtaining an aqueous suspension containing a fiber composite of fibers and inorganic particles by adjusting the water content to 90% by mass or more and 99% by mass or less in the step of adjusting the water content of the fiber composite of fiber and inorganic particles. Can do. At that time, the moisture content can be adjusted to 92% to 97% by mass, or the moisture content can be adjusted to 94% to 95% by mass.

Further, by adjusting the moisture content to 10% by mass or more and 90% by mass, a pulp containing a fiber composite of fibers and inorganic particles can be produced. At that time, the moisture content can be adjusted to 20% to 80% by mass, or the moisture content can be adjusted to 30% to 60% by mass.

Furthermore, a sheet containing a fiber composite of fibers and inorganic particles can be produced by adjusting the moisture content to less than 10% by mass. At that time, the moisture content can be adjusted to 1% by mass or more and 8% by mass or less, or the moisture content can be adjusted to 3% by mass or more and 6% by mass or less.

In the process for producing a sheet containing a fiber composite of fibers and inorganic particles, a long net paper machine, a short net paper machine, a circular net paper machine, an inclined wire type paper machine, a hybrid paper machine, or the like can be used.

Further, as one preferred embodiment, a product containing a fiber composite of fibers and inorganic particles is a process of synthesizing inorganic particles in a solution in the presence of fibers to synthesize a fiber composite of fibers and inorganic particles, fiber And a step of adjusting the particle diameter of the fiber composite of inorganic particles.

In the step of adjusting the particle diameter of the fiber composite of fiber and inorganic particles, the particle diameter can be confirmed by observation with an electron microscope or laser diffraction particle size distribution measurement. Furthermore, by adjusting the conditions for synthesizing the inorganic particles, the inorganic particles having various sizes and shapes can be made into a fiber composite with the fiber.

As a method for adjusting the particle size of the fiber composite of fibers and inorganic particles, for example, ball mill, sand grinder mill, impact mill, high pressure homogenizer, low pressure homogenizer, dyno mill, ultrasonic mill, kanda grinder, attritor, millstone mill, A vibration mill, a cutter mill, a jet mill, a disaggregator, a beating machine, a short screw extruder, a twin screw extruder, an ultrasonic stirrer, a household juicer mixer, a roller compactor and the like can be mentioned.

In the step of adjusting the particle diameter of the fiber composite of fiber and inorganic particles, the powder containing the fiber composite of fiber and inorganic particles is adjusted by adjusting the average particle diameter of the fiber composite of fibers and inorganic particles to less than 100 μm. The body can be manufactured. Preferably, the average particle diameter of the fiber composite of fibers and inorganic particles may be 1 μm or more and less than 90 μm, or the average particle diameter of the fiber composite of fibers and inorganic particles may be 10 μm or more and less than 80 μm.

In the step of adjusting the particle size of the fiber composite of fiber and inorganic particles, the fiber composite of fiber and inorganic particles is contained by adjusting the average particle size of the fiber composite of fiber and inorganic particles to 100 μm or more and less than 1000 μm. Microspheres can be produced. Preferably, the average particle diameter of the fiber composite of fiber and inorganic particles may be 200 μm or more and less than 800 μm, or the average particle diameter of the fiber composite of fiber and inorganic particles may be 300 μm or more and less than 600 μm.

In the step of adjusting the average particle diameter of the fiber composite of fiber and inorganic particles, the fiber composite of fiber and inorganic particles is adjusted by adjusting the average particle diameter of the fiber composite of fiber and inorganic particles to 1 mm or more and less than 10 mm. Can be produced. Preferably, the average particle diameter of the fiber composite of fiber and inorganic particles may be 2 mm or more and less than 8 mm, or the average particle diameter of the fiber composite of fiber and inorganic particles may be 3 mm or more and less than 6 mm.

Furthermore, as one preferable embodiment, the pellet containing the fiber composite of the fiber and the inorganic particles is obtained by synthesizing the inorganic particle in the solution in the presence of the fiber, and then synthesizing the fiber composite of the fiber and the inorganic particle. It can manufacture by pelletizing the fiber composite of an inorganic particle. Examples of the pelletizing apparatus include a pelletizer.

Moreover, the moisture content of the fiber composite of fiber and inorganic particles was solid-liquid separated by the above-described solid-liquid separator, and adjusted to 45% by mass or more and 85% by mass or less, preferably 50% by mass or more and 70% by mass or less. Later, it can be pelletized.

As one preferred embodiment, a step of synthesizing inorganic particles in a solution in the presence of fibers to synthesize a fiber composite of fibers and inorganic particles, a step of pouring the fiber composite of fibers and inorganic particles into a mold and dehydrating Thus, a mold containing a fiber composite of fibers and inorganic particles can be produced.

In one preferred embodiment, fibers are synthesized by synthesizing inorganic particles in a solution in the presence of fibers, synthesizing a fiber composite of fibers and inorganic particles, and processing a fiber composite of fibers and inorganic particles. And a yarn containing a fiber composite of inorganic particles can be produced. Examples of yarn processing include fiber making (twisting processing), spinning, drawing, thermal processing, and the like. In the case of fiber making (twisting), before the step of twisting the fiber-inorganic particle fiber composite, slitting the sheet containing the fiber-inorganic particle fiber composite adjusted to a moisture content of less than 10% by mass. It is preferable to perform a process. The yarn is preferably a yarn having a fiber diameter of 1 mm or more and 10 mm or less. A slitter etc. are mentioned as a slitting apparatus.

As one preferred embodiment, a step of synthesizing inorganic particles in a solution in the presence of fibers to synthesize a fiber composite of fibers and inorganic particles, a step of stirring the fiber composite of fibers and inorganic particles with a stirrer, fiber With the composite, a foam containing a fiber composite of fibers and inorganic particles can be produced.

Examples of the apparatus used for stirring include a homogenizer and a disperser. Moreover, as a speed | rate at the time of stirring, it can be set to 6000 rpm or more and less than 10000 rpm, or can be set to 7000 rpm or more and less than 9000 rpm.

The density of the foam is preferably in the range of 0.01 to 0.1 g / cm ³ . The density can be obtained by the following formula.

Density (g / cm ³ ) = mass of foam (g) / volume of foam (cm ³ )
There is no particular limitation on the dryer for drying the fiber composite of fibers and inorganic particles, and for example, an air dryer, a band dryer, a spray dryer, or the like can be preferably used.

Use of fiber composite The product containing the fiber composite obtained by the present invention can be mixed with other products to obtain a mixture. The product or mixture of the present invention can be used in various applications, such as paper, fiber, cellulosic composite material, filter material, paint, plastic and other resins, rubber, elastomer, ceramic, glass, tire, construction, etc. Materials (asphalt, asbestos, cement, board, concrete, brick, tile, plywood, fiberboard, etc.), various carriers (catalyst carrier, pharmaceutical carrier, agricultural chemical carrier, microbial carrier, etc.), adsorbent (impurity removal, deodorization, dehumidification) Etc.), anti-wrinkle agent, clay, abrasive, modifier, repair material, heat insulating material, moisture proof material, water repellent material, water resistant material, light shielding material, sealant, shielding material, insect repellent, adhesive, ink, cosmetics , Medical materials, paste materials, anti-discoloring agents, food additives, tablet excipients, dispersants, shape retention agents, water retention agents, filter aids, essential oil materials, oil treatment agents, oil modifiers, radio wave absorbers Insulating materials, sound insulation materials, vibration insulation materials, semiconductor sealing materials, radiation shielding materials, cosmetics, fertilizers, feeds, fragrances, additives for paints and adhesives, flame retardant materials, sanitary products (disposable diapers, sanitary napkins, incontinence It can be widely used for all uses such as a pad for a person and a breast milk pad). Moreover, it can be used for various fillers and coating agents in the above applications. The fiber composite of the present invention may be applied to papermaking applications, for example, printing paper, newspaper, inkjet paper, PPC paper, kraft paper, fine paper, coated paper, fine coated paper, wrapping paper, thin paper, color High-quality paper, cast coated paper, non-carbon paper, label paper, thermal paper, various fancy papers, water-soluble paper, release paper, process paper, base paper for wallpaper, incombustible paper, flame retardant paper, laminated board base paper, printed electronics paper, Battery separator, cushion paper, tracing paper, impregnated paper, ODP paper, building material paper, decorative paper, envelope paper, tape paper, heat exchange paper, chemical fiber paper, sterilized paper, water resistant paper, oil resistant paper, heat resistant paper, Photocatalyst paper, decorative paper (grease paper, etc.), various sanitary paper (toilet paper, tissue paper, wipers, diapers, sanitary products, etc.), tobacco paper, paperboard (liner) , Corrugating medium, such as white paperboard), paper plates base paper cup base paper, baking paper, abrasive paper, and synthetic paper. That is, according to the present invention, since a fiber composite of inorganic particles and fibers having a small primary particle size and a narrow particle size distribution can be obtained, the conventional inorganic filler having a particle size of more than 1 μm Different characteristics can be exhibited. Furthermore, unlike the case where the inorganic particles are simply blended with the fibers, if the inorganic particles are made into a fiber composite, the inorganic particles are not only easily retained on the sheet, but also a sheet in which the particles are uniformly dispersed without agglomeration. Can be obtained. In the preferred embodiment, the inorganic particles in the present invention are not only fixed on the outer surface of the fiber and the inner side of the lumen, but are also generated on the inner side of the microfibril.

Moreover, when using the fiber composite obtained by the present invention, particles generally called inorganic fillers and organic fillers and various fibers can be used in combination. For example, as inorganic filler, calcium carbonate (light calcium carbonate, heavy calcium carbonate), magnesium carbonate, barium carbonate, aluminum hydroxide, calcium hydroxide, magnesium hydroxide, zinc hydroxide, clay (kaolin, calcined kaolin, deramikaolin) ), Talc, zinc oxide, zinc stearate, titanium dioxide, silica made from sodium silicate and mineral acid (white carbon, silica / calcium carbonate fiber composite, silica / titanium dioxide fiber composite), white clay, bentonite, Examples thereof include diatomaceous earth, calcium sulfate, zeolite, an inorganic filler that regenerates and uses the ash obtained from the deinking process, and an inorganic filler that forms a fiber complex with silica or calcium carbonate in the regenerating process. As the calcium carbonate-silica composite, amorphous silica such as white carbon may be used together with calcium carbonate and / or light calcium carbonate-silica composite. Organic fillers include urea-formalin resin, polystyrene resin, phenol resin, fine hollow particles, acrylamide fiber composites, wood-derived materials (fine fibers, microfibril fibers, powdered kenaf), modified insolubilized starch, ungelatinized starch Etc. Fibers include natural fibers such as cellulose, synthetic fibers that are artificially synthesized from raw materials such as petroleum, regenerated fibers (semi-synthetic fibers) such as rayon and lyocell, and inorganic fibers. Can be used. In addition to the above, the natural fibers include protein fibers such as wool, silk thread and collagen fibers, and complex sugar chain fibers such as chitin / chitosan fibers and alginic acid fibers. Examples of the cellulose-based raw material include pulp fibers (wood pulp and non-wood pulp), animal-derived cellulose such as bacterial cellulose and sea squirt, and algae. The wood pulp may be produced by pulping the wood raw material. Wood materials include red pine, black pine, todomatsu, spruce, beech pine, larch, fir, tsuga, cedar, hinoki, larch, syrup, spruce, hiba, douglas fir, hemlock, white fur, spruce, balsam fur, cedar, pine, Coniferous trees such as Merck pine, Radiata pine, etc., and mixed materials thereof, beech, hippopotamus, alder tree, oak, tab, shii, birch, broadleaf tree, poplar, tamo, dragonfly, eucalyptus, mangrove, lawan, acacia, etc. Examples are materials. The method for pulping the wood raw material is not particularly limited, and examples thereof include a pulping method generally used in the paper industry. Wood pulp can be classified by pulping method, for example, chemical pulp digested by methods such as kraft method, sulfite method, soda method, polysulfide method; mechanical pulp obtained by pulping by mechanical force such as refiner, grinder; Semi-chemical pulp obtained by carrying out pulping by mechanical force after pretreatment by; waste paper pulp; deinked pulp and the like. Wood pulp may be unbleached (before bleaching) or bleached (after bleaching). Examples of the non-wood-derived pulp include cotton, hemp, sisal hemp, manila hemp, flax, straw, bamboo, bagasse, kenaf, sugar cane, corn, rice straw, straw, honey and so on. Wood pulp and non-wood pulp may be either unbeaten or beaten. Further, these cellulose raw materials are further processed to give finely pulverized cellulose such as powdered cellulose, chemically modified cellulose such as oxidized cellulose, and cellulose nanofiber: CNF (microfibrillated cellulose: MFC, TEMPO oxidized CNF, phosphoric acid esterified) CNF, carboxymethylated CNF, mechanically ground CNF). Synthetic fibers include polyester, polyamide, polyolefin, acrylic fiber, semi-spun fibers include rayon and acetate, and inorganic fibers include glass fiber, carbon fiber, and various metal fibers. About these, these may be used alone or in combination of two or more.

Further, various organic materials such as polymers and various inorganic materials such as pigments may be added to the fiber composite molding later.

Hereinafter, the present invention will be described in more detail with specific experimental examples, but the present invention is not limited to the following experimental examples. Unless otherwise specified in the present specification, concentrations and parts are based on weight, and numerical ranges are described as including the end points.

Experiment A
Sample 1: 140 g of an aqueous suspension containing a fiber composite of magnesium carbonate fine particles and fibers (Wako Pure Chemical Industries) and 140 g of hardwood bleached kraft pulp (LBKP, CSF: 370 ml, average fiber length: 0.75 mm) An aqueous suspension containing was prepared. The aqueous suspension 14L is placed in a 45L cavitation apparatus shown in FIG. 1, and while circulating the reaction solution, carbon dioxide gas is blown into the reaction vessel, and a fiber composite of magnesium carbonate fine particles and fibers by the carbon dioxide method. Was synthesized. The reaction temperature was about 36 ° C., the carbon dioxide gas was supplied from a commercially available liquefied gas, and the amount of carbon dioxide blown was 4 L / min. When the pH of the reaction solution reaches about 7.8, the introduction of CO ₂ is stopped (the pH before the reaction is about 9.5), and then cavitation is generated and the slurry is circulated in the apparatus for 30 minutes. Sample 1 (water content: 96% by mass) was obtained. The obtained fiber composite had a fiber: inorganic particle weight ratio of 45:55. Here, the weight ratio was calculated based on the ash content obtained from the ratio of the weight of the remaining ash to the original solid content after heating the fiber composite at 525 ° C. for about 2 hours (JIS P 8251: 2003). .

In the synthesis of the fiber composite, cavitation bubbles were generated in the reaction vessel by circulating the reaction solution and injecting it into the reaction vessel as shown in FIG. Specifically, the reaction solution was injected at high pressure through a nozzle (nozzle diameter: 1.5 mm) to generate cavitation bubbles. The jet velocity was about 70 m / s, and the inlet pressure (upstream pressure) was The outlet pressure (downstream pressure) was 7 MPa and 0.3 MPa.

Sample 2: aqueous suspension containing a fiber composite of magnesium carbonate fine particles and fibers (no CV)
A 3L stainless steel container was used as the reaction vessel, the amount of pulp charged was 20 g, the amount of carbon dioxide blown was 0.57 L / min, and the carbonation reaction was stirred (800 rpm) with a three-one motor in a 35 ° C water bath. Sample 2 (water content: 96% by mass) was obtained in the same manner as Sample 1, except that the procedure was carried out. The fiber / inorganic particle weight ratio of the obtained fiber composite was 45:55.

Sample 3: A 1% aqueous pulp slurry (LBKP / NBKP = 8/2, 500 g) containing a barium sulfate particle-fiber fiber composite and barium hydroxide octahydrate (Wako Pure Chemicals, 5 .82 g) was mixed with a three-one motor (1000 rpm), and sulfuric acid (Wako Pure Chemicals, 2.1 g) was added dropwise. After completion of dropping, stirring was continued as it was for 30 minutes to obtain Sample 3 (water content: 96.0%). In addition, it was 1.21 mm when the average fiber length of the used mixed pulp was measured with the fiber tester (Lorentzen & Wettre company). The fiber / inorganic particle weight ratio of the obtained fiber composite was 56:44.

Sample 4: A sample containing a slurry of 0.8% aramid fibers (Twaron RD-1094, Teijin, 625 g) as an aqueous suspension fiber containing a fiber composite of barium sulfate particles and aramid fibers. 1 was obtained in the same manner as in Example 1 to obtain Sample 4 (water content: 98.4%).

The obtained fiber composite slurry (3 g in terms of solid content) was suction filtered with a filter paper, the residue was dried in an oven (105 ° C., 2 hours), and the ash content was measured. The fiber of the fiber composite: inorganic particles The weight ratio was 55:45.

Sample 5: A 1% aqueous pulp slurry (LBKP / NBKP = 8/2, 500 g) containing a fiber composite of aluminum hydroxide particles and fibers and an aluminum sulfate aqueous solution (Al ₂ (SO) ₄ conversion) 11 g) was mixed with a three-one motor (1000 rpm), and an aqueous solution (concentration 5%) of sodium hydroxide (Wako Pure Chemicals, 15.4 g) was added dropwise. After completion of the dropping, stirring was continued for 30 minutes to obtain Sample 5 (water content: 98.0%).

The weight ratio of fiber: inorganic particles of the obtained fiber composite was 58:42.

Sample 6: Pulp containing a fiber composite of hydrotalcite and fibers (1) Preparation of alkali solution and acid solution A solution for synthesizing hydrotalcite (HT) was prepared. As an alkaline solution (A solution), a mixed aqueous solution of Na ₂ CO ₃ (Wako Pure Chemical Industries) and NaOH (Wako Pure Chemical Industries) was prepared. In addition, as an acid solution (B solution), a mixed aqueous solution of MgCl ₂ (Wako Pure Chemical Industries) and AlCl ₃ (Wako Pure Chemical Industries), a mixed aqueous solution of ZnCl ₂ (Wako Pure Chemical Industries) and AlCl ₃ (Wako Pure Chemical Industries) were prepared. .
・ Alkaline solution (A solution, Na ₂ CO ₃ concentration: 0.05M, NaOH concentration: 0.8M)
Acid solution (B solution, Mg-based, MgCl ₂ concentration: 0.3M, AlCl ₃ concentration: 0.1M)
Acid solution (B solution, Zn-based, ZnCl ₂ concentration: 0.3M, AlCl ₃ concentration: 0.1M)
(2) Synthesis of fiber composite An alkaline solution is put into a 10 L reaction vessel, and an acid solution (Mg-based) is dropped while stirring to add hydrotalcite fine particles (Mg ₆ Al ₂ (OH) 16 CO ₃ .4H ₂ O). ) Was synthesized. The reaction temperature was 60 ° C., the dropping rate was 15 ml / min, and dropping was stopped when the pH of the reaction solution reached about 7. After completion of the dropping, the reaction solution was stirred for 30 minutes and washed with about 10 times the amount of water to remove the salt.

Cellulose fiber was used as the fiber to be converted into a fiber composite. Specifically, it contains hardwood bleached kraft pulp (LBKP, manufactured by Nippon Paper Industries) and softwood bleached kraft pulp (NBKP, manufactured by Nippon Paper Industries) at a weight ratio of 8: 2, and is a Canadian standard drainage using a single disc refiner (SDR). Pulp fibers with a degree adjusted to 390 ml were used.

Pulp fiber was added to the alkaline solution to prepare an aqueous suspension containing pulp fiber (pulp fiber concentration: 1.56%, pH: about 12.4). This aqueous suspension (pulp solid content 30 g) is put into a 10 L reaction vessel, and while stirring the aqueous suspension, an acid solution (Mg-based) is dropped to form a fiber composite of hydrotalcite fine particles and fibers. Was synthesized. Using an apparatus as shown in FIG. 1, the reaction temperature was 60 ° C., the dropping rate was 15 ml / min, and dropping was stopped when the pH of the reaction solution reached about 7. After completion of the dropwise addition, the reaction solution was stirred for 30 minutes and washed with 10 times the amount of water to remove the salt.

A pulp was produced from the synthesized fiber composite with a filter press (manufactured by Nippon Kara Kogyo Co., Ltd.) to obtain Sample 6 (water content 62.5% by mass). The fiber / inorganic particle weight ratio of the obtained fiber composite was 56:44.

Sample 7: Pulp was produced from the synthesized fiber composite by a filter press (manufactured by Fuji Powder Co., Ltd.) using pulp sample 3 containing barium sulfate particles and fiber fiber composite , and sample 7 (water content) 65.0% by mass). The fiber / inorganic particle weight ratio of the obtained fiber composite was 56:44.

Sample 8: Sheet calcium hydroxide containing calcium carbonate particles and fiber composite (slaked lime: Ca (OH) ₂ , 300 g) and softwood bleached kraft pulp (NBKP, Canadian standard freeness CSF: 215 mL, 300 g) An aqueous suspension 30 L containing was prepared. This aqueous suspension was put into a 40 L sealed device, carbon dioxide was blown into the reaction vessel to generate cavitation, and a fiber composite of calcium carbonate particles and fibers was synthesized by the carbon dioxide method. The reaction temperature was about 25 ° C., carbon dioxide was supplied from a commercial liquefied gas, the amount of carbon dioxide blown was 12 L / min, and the reaction was stopped when the pH of the reaction solution reached about 7 (before the reaction). PH is about 12.8). The fiber / inorganic particle weight ratio of the obtained fiber composite was 45:55.

In the synthesis of the fiber composite, cavitation bubbles were generated in the reaction vessel by circulating the reaction solution and injecting it into the reaction vessel as shown in FIG. Specifically, the reaction solution is injected at high pressure through a nozzle (nozzle diameter: 1.5 mm) to generate cavitation bubbles, the jet velocity is about 70 m / s, the inlet pressure (upstream pressure) is 7 MPa, The outlet pressure (downstream pressure) was 0.3 MPa.

To the obtained fiber composite (concentration: 1%), a cationic retention agent (ND300, Hymo) and an anionic retention agent (FA230, Hymo) were added at a solid content of 100 ppm each to make a paper slurry. Was prepared. Next, a sheet was produced from this stock slurry using a long paper machine at a speed of 10 m / min. In addition, as a control, a pulp slurry (LBKP / NBKP = 8/2, CSF = 380 mL, average fiber length: 1.5 mm), a cationic retention agent (ND300, Hymo) and an anionic retention agent (FA230, Hymo) Was added at a solid content of 100 ppm each, and a sheet was produced using a long paper machine to obtain Sample 8 (moisture content of 8.0 mass%). The fiber / inorganic particle weight ratio of the obtained fiber composite was 56:44.

Sample 9: A slurry having a concentration of about 0.2% was prepared using tap water from the residue obtained by suction-filtering the sheet sample 1 containing a fiber composite of magnesium carbonate particles and fibers with a filter paper. This slurry was disaggregated for 5 minutes with a standard disaggregator specified in JIS P 8220-1: 2012, and then a handsheet having a basis weight of 60 g / m ² was prepared using a 150 mesh wire in accordance with JIS P 8222: 1998. It produced and the sample 9 (water content 8.0 mass%) was obtained. The fiber / inorganic particle weight ratio of the obtained fiber composite was 56:44.

Sample 10: Powder containing fiber composite of calcium carbonate fine particles and fiber <Synthesis of calcium carbonate / fiber fiber composite>
An aqueous suspension containing calcium hydroxide (slaked lime: Ca (OH) ₂ , Wako Pure Chemicals, 2% by weight) and fiber (0.5%, LBKP / NBKP = 8/2, 500 g)) was prepared. 9.5 L of this aqueous suspension was put into a 45 L cavitation apparatus, carbon dioxide gas was blown into the reaction vessel, and a fiber composite of calcium carbonate fine particles and fibers was synthesized by a carbon dioxide gas method. The reaction temperature was about 25 ° C., carbon dioxide was supplied from a commercial liquefied gas, the amount of carbon dioxide blown was 12 L / min, and the reaction was stopped when the pH of the reaction solution reached about 7 (before the reaction). PH is about 12.8).

The obtained fiber composite was dried by a spray dryer (manufactured by Okawara Kako Co., Ltd.) to produce a powder, and sample 10 was obtained (particle diameter: 100 μm). The weight ratio of fiber: inorganic particles was 45:55.

Sample 11: Powder as in Sample 10 except that the powdered softwood bleached kraft pulp containing a fiber composite of calcium carbonate fine particles and fibers was replaced with powdered cellulose (KC Flock W-06MG, manufactured by Nippon Paper Industries Co., Ltd.) The sample 11 was obtained. (Particle diameter: 100 μm). The weight ratio of fiber: inorganic particles was 43:57.

Sample 12: Sample 12 was obtained by preparing microspherical particles using an extrusion kneading granulator (manufactured by Kansai Kikai Seisakusho Co., Ltd.) using microspherical particle sample 1 containing a fiber composite of magnesium carbonate particles and fibers. (Particle diameter: 800 μm). The weight ratio of fiber: inorganic particles was 47:53.

Sample 13: A granule was prepared using a roller sampler (manufactured by Matsubo Co., Ltd.) using a granule sample 1 containing a fiber composite of magnesium carbonate particles and fibers to obtain a sample 13 (particle diameter: 6 mm). The weight ratio of fiber: inorganic particles was 44:56.

Fiber composites of inorganic particles and fibers with high moisture content (samples 1 to 5) are less expensive to manufacture than fiber composites of inorganic particles and fibers with low moisture content (samples 6 to 13). In addition, the manufacturing process was short and the fiber composite could be produced efficiently. On the other hand, the fiber composites (samples 6 to 13) of inorganic particles and fibers having a low water content are compared with the fiber composites (samples 1 to 5) of inorganic particles and fibers having a high water content. Compared with a fiber composite sheet having no fiber (Comparative Example 1), transfer and blending into a product were easy.

Sample 14: A pellet sample 1 containing a fiber composite of magnesium carbonate particles and fibers was pelletized by a pelletizer (Fuji Paudal Co., Ltd.) (absolutely dry 4 g, pellet diameter 35 mm).

Sample 15: Sample 15 was prepared in the same manner as Sample 14, except that the pelleted softwood bleached kraft pulp containing a fiber composite of magnesium carbonate particles and powdered cellulose was replaced with powdered cellulose (KC Flock W-06MG, Nippon Paper Industries). (Absolutely 4 g, pellet diameter: 35 mm) was obtained.

Sample 16: A sample 16 was obtained by using a mold sample 1 containing a fiber composite of magnesium carbonate particles and fibers to produce a mold using an injection molding machine (Leo Lab Co., Ltd.).

Sample 17: A sheet of the fiber-making yarn sample 9 containing a fiber composite of magnesium carbonate particles and fibers was processed into a width of 8 mm with a slitter and then processed with a twisting machine to obtain a paper-making yarn of 1 mm.

Sample 18: Calcium carbonate in the same manner as Sample 10, except that the foamed softwood bleached kraft pulp containing a fiber composite of calcium carbonate particles and fibers was replaced with powdered cellulose (KC Flock W-06MG, Nippon Paper Industries). A fiber composite of particles and powdered cellulose was obtained. The obtained fiber composite was stirred with a three-one motor at 6000 rpm for 5 minutes. Thereafter, the obtained sample (12 g) was dried in an aluminum cup with a dryer at 60 ° C. for 24 hours to produce a foam (density: 0.06 g / cm ³ ) to obtain Sample 18.

Fiber composites of inorganic particles and fibers (samples 14 to 18) in the form of pellets, molds, fiber threads, and foams (samples 14 to 18) are excellent in handling and function of fiber composites of fibers and inorganic particles alone (difficulty) A product having flammability, opacity, radiation shielding, adsorbability, antibacterial properties, etc. is obtained.

Experiment 1: Production of Composite of Inorganic Particles and Fibers A composite of inorganic particles and pulp fibers was synthesized by the following procedure and used in Experiment 3.

(Sample 1: Composite of calcium carbonate and pulp fiber, Fig. 2)
Using a reactor as shown in FIG. 5, a composite of calcium carbonate and fiber was synthesized by the carbon dioxide gas method. Ultra fine bubble generator (UFB generator, YJ-9) for 1500 L of aqueous suspension of 15 kg of calcium hydroxide (Okutama Kogyo, Tamaace U) and 15 kg of LBKP (CSF = 500 mL, average fiber length = 0.76 mm) The reaction liquid was circulated at a pump flow rate of 80 L / min using Envirovision (FIG. 6) (injection speed from nozzle: 125 L / min · cm ² ). A large amount of fine bubbles (diameter: 1 μm or less, average particle size: 137 nm) containing carbon dioxide are generated in the reaction liquid by blowing carbon dioxide from the air supply port of the ultra fine bubble generator, and calcium carbonate is formed on the pulp fiber. Particles were synthesized. The reaction was carried out at a reaction temperature of 20 ° C. and the amount of carbon dioxide blown at 20 L / min. The reaction was stopped when the pH of the reaction solution reached about 7, and sample 2 was obtained (the pH before the reaction was about 13). ). The obtained calcium carbonate and pulp fiber composite had an ash content of 53%, and the average primary particle size of the inorganic particles was 50 nm.

(Sample 2: Composite of magnesium carbonate and pulp fiber, FIG. 3)
350 g of magnesium hydroxide (Ube Materials, UD653) and 350 g of kraft pulp (LBKP / NBKP = 1/1, CSF: 370 ml, average fiber length: 0.9 mm) were added to water to prepare an aqueous suspension.

As shown in FIG. 7, 35 L of this aqueous suspension is put into a cavitation apparatus (45 L volume), and while circulating the reaction solution, carbon dioxide gas is blown into the reaction vessel and the magnesium carbonate fine particles and the fibers are separated by the carbon dioxide method. A complex was synthesized. The reaction start temperature was about 40 ° C., the carbon dioxide gas was supplied with a commercially available liquefied gas, and the amount of carbon dioxide blown was 20 L / min. When the pH of the reaction solution reached about 7.8, the introduction of CO ₂ was stopped (pH before the reaction was 10.3), and then the cavitation generation and the circulation of the slurry in the apparatus were continued for 30 minutes, A composite of magnesium carbonate fine particles and pulp fibers was obtained (average primary particle diameter of inorganic particles: 1.0 μm).

In the synthesis of the complex, cavitation bubbles were generated in the reaction vessel by circulating the reaction solution and injecting it into the reaction vessel. Specifically, the reaction solution was injected at high pressure through a nozzle (nozzle diameter: 1.5 mm) to generate cavitation bubbles. The jet velocity was about 70 m / s, and the inlet pressure (upstream pressure) was The outlet pressure (downstream pressure) was 2 MPa and 0.2 MPa.

Measured weight ratio of fiber: inorganic particles for the obtained composite was 40:60 (ash content: 60%). The weight ratio (ash content) was determined by suction-filtering the composite slurry (3 g in terms of solid content) using filter paper, then drying the residue in an oven (105 ° C., 2 hours), and burning the organic content at 525 ° C. It was calculated from the weight before and after combustion.

(Sample 3: Composite of hydrotalcite and pulp fiber, Fig. 4)
In order to synthesize Mg ₆ Al ₂ (OH) ₁₆ CO ₃ .4H ₂ O as hydrotalcite (HT), Na ₂ CO ₃ (Wako Pure Chemicals) and NaOH (Wako Pure Chemicals) are used as alkaline solutions (A solutions). As a mixed aqueous solution and an acid solution (B solution), a mixed aqueous solution of MgCl ₂ (Wako Pure Chemical Industries) and AlCl ₃ (Wako Pure Chemical Industries) was prepared.
・ Alkaline solution (A solution, Na ₂ CO ₃ concentration: 0.05M, NaOH concentration: 0.8M)
Acid solution (B solution, Mg-based, MgCl ₂ concentration: 0.3M, AlCl ₃ concentration: 0.1M)
Cellulose fibers were used as the fibers to be combined. Specifically, it contains hardwood bleached kraft pulp (LBKP, manufactured by Nippon Paper Industries) and softwood bleached kraft pulp (NBKP, manufactured by Nippon Paper Industries) at a weight ratio of 8: 2, and is a Canadian standard drainage using a single disc refiner (SDR). Pulp fibers whose degree was adjusted to 390 ml were used (average fiber length 0.8 mm).

Pulp fiber was added to the alkaline solution to prepare an aqueous suspension containing pulp fiber (pulp fiber concentration: 1.56%, pH: about 12.4). This aqueous suspension (pulp solid content 30 g) is put into a 10 L reaction vessel, and while stirring the aqueous suspension, an acid solution (Mg-based) is dropped to form a composite of hydrotalcite fine particles and fibers. Synthesized. Using an apparatus as shown in FIG. 8, the reaction temperature was 60 ° C., the dropping rate was 15 ml / min, and the dropping was stopped when the pH of the reaction solution reached about 7. After completion of the dropwise addition, the reaction solution was stirred for 30 minutes and washed with 10 times the amount of water to remove the salt, thereby obtaining Sample 3 (average primary particle size of inorganic particles: 20 nm). Sample 3 had an ash content of 50%.

Experiment 2: Production of cellulose nanofiber (cationized cellulose nanofiber: cationized CNF)
To a pulper that can stir the pulp, 200 g by dry weight of pulp (LBKP, Nippon Paper Industries) and 24 g by dry weight of sodium hydroxide were added, and water was added so that the pulp solid concentration was 15%. Thereafter, the mixture was stirred at 30 ° C. for 30 minutes, and then the temperature was raised to 70 ° C., and 190 g (converted as an active ingredient) of 3-chloro-2-hydroxypropyltrimethylammonium chloride as a cationizing agent was added. After reacting for 1 hour, the reaction product was taken out, neutralized and washed to obtain a cation-modified pulp. A 1% slurry of cationized pulp was treated with a small high-pressure filter press (YTOH2 type, manufactured by Iwata Kikai Co., Ltd.) at 2 MPa for 15 minutes to produce cationized cellulose nanofibers (solid content: 7% by mass).

(Carboxymethylated cellulose nanofiber: CCM CNF)
To a reactor capable of stirring the pulp, 112 g of a 50 wt% sodium hydroxide aqueous solution and 67 g of water were added while stirring 250 g of pulp (LBKP, manufactured by Nippon Paper Industries Co., Ltd.) in dry weight. After stirring at 30 ° C. for 30 minutes, 364 g of 35 wt% aqueous sodium monochloroacetate solution was added with stirring. Then, it stirred at 30 degreeC for 30 minutes, heated up to 70 degreeC over 30 minutes, and reacted at 70 degreeC for 1 hour. Thereafter, the reaction product was taken out, neutralized and washed to obtain carboxymethylated cellulose (carboxymethylated pulp) having a carboxymethyl substitution degree of 0.25 per glucose unit. Cellulose nanofibers were produced by treating 1% slurry of carboxymethylated pulp at 2 MPa for 15 minutes using a small high-pressure filter press (YTOH type 2, manufactured by Iwata Kikai Co., Ltd.).

(TEMPO oxidized cellulose nanofiber: TEMPO oxidized CNF)
15 g of powdered cellulose (particle size: 24 μm, manufactured by Nippon Paper Chemicals) (absolutely dried), 78 mg (0.5 mmol) of TEMPO (2,2,6,6-tetramethylpiperidine-1-oxyl, Sigma Aldrich) and bromide The mixture was added to 500 ml of an aqueous solution in which 755 mg (7 mmol) of sodium was dissolved, and stirred until the powdered cellulose was uniformly dispersed. After adding 50 ml of a sodium hypochlorite aqueous solution (effective chlorine 5%) to the reaction system, the pH was adjusted to 10.3 with a 0.5N hydrochloric acid aqueous solution to start the oxidation reaction. During the reaction, the pH in the system was lowered, but a 0.5N aqueous sodium hydroxide solution was successively added to adjust the pH to 10. After reacting for 2 hours, powdered cellulose oxidized by centrifugal operation (6000 rpm, 30 minutes, 20 ° C.) was separated and sufficiently washed with water to obtain oxidized powdered cellulose. A 2% (w / v) slurry of oxidized powdered cellulose was treated with a mixer at 12000 rpm for 15 minutes, and the powdered cellulose slurry was further treated with an ultrahigh pressure homogenizer 5 times at a pressure of 140 MPa to produce cellulose nanofibers. .

Experiment 3: Production and evaluation of foam (1) Experiment 3-1: Stability of foam (Experiment b) 395 ml of a slurry (concentration 1.0%) of calcium carbonate / inorganic composite (sample 1) synthesized in Experiment 1 In contrast, 1.3 ml of a paper strength improver (WS-2024, manufactured by Starlight PMC, concentration 3.0%) and a retention agent (ND-300, manufactured by Hymo, concentration 0.05%) were added while stirring. 6 ml of anionic surfactant (sodium dodecyl sulfate, Wako first grade, manufactured by Wako Pure Chemical Industries, Ltd.) 0.24 g was added to prepare a slurry for producing a foam. Using a multi-disperser (MULTI DISPERSER SMT, manufactured by SMT), the slurry was stirred at 6000 rpm for 10 minutes to foam.

(Experiment c) An experiment was performed in the same manner as Experiment B except that 0.4 g of the cationized cellulose nanofiber produced in Experiment 2 was further added to the slurry and then foamed, and calcium carbonate was not added. .

(result)
Comparing experiment b and experiment c, the stability of the foam could be improved by adding cellulose nanofiber (CNF). In the production of the foam, the stability of the foam (foam) becomes important, and the stability of the foam could be improved by adding CNF according to the present invention.

(2) Experiment 3-2: Production of foam (foam) (Forms B to C) The foam obtained in Experiments bc was placed in an aluminum cup (diameter: about 7 cm, height: about 2 cm), and natural convection type Using a thermostat (DSN-115S, manufactured by ISUZU), it was dried at 105 ° C. for 18 hours to obtain a foam (Form C: FIG. 9).
(Forms D to E) Foams were obtained in the same manner as in Form C except that CMized CNF or TEMPO oxidized CNF was used instead of cationized CNF (Form D: CMized CNF, Form E: TEMPO oxidized CNF) , FIG. 10).
(Forms F to G) A foam was obtained in the same manner as Form C except that the composite of Sample 2 or Sample 3 was used instead of the composite of Sample 1 (Form F: Composite of magnesium carbonate and pulp fiber) Body, Form G: a composite of hydrotalcite and pulp fibers).
(Form H) A foam was obtained in the same manner as Form G except that TEMPO oxidized CNF was used instead of cationized CNF.

(Strength of foam)
The strength of the obtained foam (foam) was evaluated by tactile sensation. Specifically, the surface of the foam was pushed in by about 5 mm with a finger, and the repulsive force at this time was evaluated in three stages according to the following criteria.
○: Feeling repulsive force, the shape of the foam does not collapse by pushing.
Δ: A certain amount of repulsive force is felt, but the shape of the foam collapses when pressed.
X: Feels almost no repulsive force, and the shape of the foam collapses when pressed.

(Foam ash)
After the foam was heated at 525 ° C. for about 2 hours, the weight ratio (ash content) of the inorganic content was calculated from the ratio between the weight of the remaining ash and the original solid content (JIS P 8251: 2003).

(Foam density)
The weight of the aluminum cup containing the foam was measured, and the weight of the aluminum cup measured in advance was subtracted therefrom to obtain the weight of the foam. The foam radius was obtained by measuring the radius and thickness of the foam and dividing the weight of the foam by the volume to obtain the density of the foam.

As shown in the above table, the strength of the obtained foam was improved by adding cellulose nanofiber (CNF) based on the present invention. As a factor of the strength improvement according to the present invention, structural strength is imparted to the foam by the interaction between CNFs or the interaction between composite pulp fibers or inorganic particles and CNF (intermolecular interaction, hydrogen bonding, etc.). It is thought that it was done.

Claims

A product that contains a fiber composite of fibers and inorganic particles and is in the form of an aqueous suspension, pulp, sheet, powder, microsphere, granule, pellet, mold, thread, or foam.
The product of claim 1, wherein the product is an aqueous suspension.
The product according to claim 2, wherein the water content of the aqueous suspension is 90% by mass or more and 99% by mass or less.
The product of claim 1, wherein the product is pulp.
The product according to claim 4, wherein the moisture content of the pulp is 10% by mass or more and less than 90% by mass.
The product according to claim 1, wherein the product is a sheet.
The product according to claim 6, wherein the moisture content of the sheet is less than 10% by mass.
The product according to claim 6 or 7, wherein the sheet is a paper containing the composite.
The product according to claim 1, wherein the product is a powder.
The product according to claim 9, wherein the powder has an average particle size of less than 100 μm.
The product according to claim 1, wherein the product is a microspherical particle.
The product according to claim 11, wherein an average particle diameter of the microspherical particles is 100 µm or more and less than 1000 µm.
The product according to claim 1, wherein the product is a granule.
The product according to claim 13, wherein the average particle diameter of the granules is 1.0 mm or more and less than 10 mm.
The product of claim 1, wherein the product is a pellet.
The product according to claim 15, wherein the pellet diameter of the product is 10 mm or more and 50 mm or less.
The product of claim 1, wherein the product is a mold.
The product according to claim 17, wherein the mold has a diameter of 5 cm or more and 100 cm or less.
The product according to claim 1, wherein the product is a yarn.
The product according to claim 19, wherein the fiber diameter of the yarn is 1 mm or more and 10 mm or less.
The product of claim 1, wherein the product is a foam.
The product according to claim 21, wherein the density of the foam is 0.01 to 0.1 g / cm 3 or less.
The product according to any one of claims 1 to 22, wherein the average primary particle diameter of the inorganic particles is 200 nm or less.
The product according to any one of claims 6 to 8, wherein at least a part of the inorganic particles is a metal salt of calcium, magnesium or barium.
At least a part of the inorganic particles are metal particles containing silicic acid or a metal salt of aluminum, or titanium, copper, silver, iron, manganese or zinc. Product listed.
The product according to any one of claims 1 to 25, wherein the fiber is a chemical fiber, a recycled fiber, or a natural fiber.
The product according to claim 26, wherein the fiber is a cellulose fiber derived from wood.
The product according to any one of claims 1 to 27, wherein the weight ratio of the fibers to the inorganic particles is 5/95 to 95/5.
A mixture containing the product according to any one of claims 1 to 28.
A method for producing a product containing a composite of fibers and inorganic particles,
Synthesizing inorganic particles in a solution in the presence of fibers to synthesize a composite of fibers and inorganic particles;
Adjusting the moisture content of the composite of fibers and inorganic particles,
Including the above method.
A method for producing an aqueous suspension containing a composite of fibers and inorganic particles,
In the step of adjusting the moisture content of the composite of fibers and inorganic particles, the moisture content is adjusted to 90% by mass or more and 99% by mass or less.
The method of claim 30.
A method for producing a pulp containing a composite of fibers and inorganic particles,
In the step of adjusting the moisture of the composite of fibers and inorganic particles, the moisture content is adjusted to 10% by mass or more and less than 90% by mass;
The method of claim 30.
A method for producing a sheet containing a composite of fibers and inorganic particles,
In the step of adjusting the moisture in the composite of fibers and inorganic particles, the moisture content is adjusted to less than 10% by mass,
The method of claim 30.
A method for producing a product containing a composite of fibers and inorganic particles,
Synthesizing inorganic particles in a solution in the presence of fibers to synthesize a composite of fibers and inorganic particles;
Adjusting the particle size of the composite of fibers and inorganic particles,
Including the above method.
A method for producing a powder containing a composite of fibers and inorganic particles,
In the step of adjusting the particle diameter of the composite of fibers and inorganic particles, the average particle diameter of the composite of fibers and inorganic particles is adjusted to less than 100 μm.
35. The method of claim 34.
A method for producing microspherical particles containing a composite of fibers and inorganic particles,
In the step of adjusting the particle diameter of the composite of fibers and inorganic particles, the average particle diameter of the composite of fibers and inorganic particles is adjusted to 100 μm or more and less than 1000 μm.
35. The method of claim 34.
A method for producing granules containing a composite of fibers and inorganic particles,
In the step of adjusting the particle size of the composite of fibers and inorganic particles, the average particle size of the composite of fibers and inorganic particles is adjusted to 1.0 mm or more and less than 10 mm.
35. The method of claim 34.
A method for producing a pellet containing a composite of fibers and inorganic particles,
Synthesizing inorganic particles in a solution in the presence of fibers to synthesize a composite of fibers and inorganic particles;
A step of pelletizing a composite of fibers and inorganic particles;
Including the above method.
A step of solid-liquid separation of the moisture content of the composite of fibers and inorganic particles in a solid-liquid separation device, and adjusting to 45 to 80% by mass;
40. The method of claim 38, comprising:
A method for producing a mold containing a composite of fibers and inorganic particles,
Synthesizing inorganic particles in a solution in the presence of fibers to synthesize a composite of fibers and inorganic particles;
A process of pouring a composite of fibers and inorganic particles into a mold to dehydrate,
Including the above method.
A method for producing a yarn containing a composite of fibers and inorganic particles,
Synthesizing inorganic particles in a solution in the presence of fibers to synthesize a composite of fibers and inorganic particles;
The said method including the process of carrying out the yarn process of the composite of a fiber and an inorganic particle.
A step of slitting a sheet containing a composite of fibers and inorganic particles adjusted to a moisture content of less than 10% by weight before the step of processing the composite of fibers and inorganic particles;
42. The method of claim 41, comprising:
A method for producing a foam containing a composite of fibers and inorganic particles,
Synthesizing inorganic particles in a solution in the presence of fibers to synthesize a composite of fibers and inorganic particles;
A step of stirring the composite of fibers and inorganic particles with a stirrer;
Including the above method.
44. The method according to claim 43, further comprising the step of drying the foamed foam.