JP2018184690A - Method for producing inorganic particle composite fiber - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method that makes it possible to produce a polar chemical fiber containing a greater quantity of inorganic matter.SOLUTION: A method for producing an inorganic particle composite fiber includes a beating step for beating a polar chemical fiber by wetting or drying, and a composite fiber production step for synthesizing an inorganic particle in a slurry containing the chemical fiber after the beating step, and producing a composite fiber of the chemical fiber and the inorganic particle.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a method for producing an inorganic particle composite fiber.

  There is a technique for imparting a desired function to a fiber by attaching inorganic particles to the fiber. For example, Patent Document 1 describes a method of producing a composite of calcium carbonate particles and fibers by synthesizing calcium carbonate in a solution containing fibers in the presence of cavitation bubbles.

Japanese Patent Laying-Open No. 2015-199655 (published on November 12, 2015)

  If more inorganic substances can be attached to the fibers, it is useful because higher functions can be exhibited. For example, it is necessary to attach more inorganic substances to chemical fibers. In view of this, an object of one embodiment of the present invention is to provide a method capable of producing a polar chemical fiber including more inorganic substances.

  The present invention includes, but is not limited to, the following inventions.

  (1) A beating step of beating polar chemical fibers in a wet or dry manner, and synthesizing inorganic particles in a slurry containing the chemical fibers after the beating step, producing a composite fiber of the chemical fibers and the inorganic particles A method for producing an inorganic particle composite fiber.

  According to one aspect of the present invention, there is an effect that an inorganic particle composite fiber including more inorganic particles can be produced.

It is a figure which shows the observation result by the laser microscope of the lyocell (trademark) used in Example 1, (a) is a figure which shows the result of having observed the lyocell (trademark) before beating at 100 time magnification, ( b) is a diagram showing the results of observing Lyocell (registered trademark) after beating at a magnification of 100 times. It is a figure which shows the observation result by the laser microscope of the polyester fiber used in Example 2, (a) is a figure which shows the result of having observed the polyester fiber before beating by 100 time, (b) is the figure after beating It is a figure which shows the result of having observed the polyester fiber at 100 time magnification. It is a figure which shows the observation result by the scanning electron microscope of the composite fiber produced in Example 1 and Comparative Example 1, (a) is a figure which shows the result of having observed the composite fiber of Comparative Example 1 at 3000 times magnification, (B) is a figure which shows the result of having observed the composite fiber of the comparative example 1 by 10,000 times, (c) is a figure which shows the result of having observed the composite fiber of Example 1 by 3000 times, (d ) Is a diagram showing the results of observing the conjugate fiber of Example 1 at a magnification of 10,000 times. It is a figure which shows the observation result by the scanning electron microscope of the composite fiber produced in Example 2 and Comparative Example 2, (a) is a figure which shows the result of observing the composite fiber of Comparative Example 1 at 3000 times magnification, (B) is a figure which shows the result of having observed the composite fiber of the comparative example 1 by 10,000 times, (c) is a figure which shows the result of having observed the composite fiber of Example 1 by 3000 times, (d ) Is a diagram showing the results of observing the conjugate fiber of Example 1 at a magnification of 10,000 times. It is a figure which shows the observation result by the scanning electron microscope of the composite fiber produced in Example 3, (a) is a figure which shows the result of having observed the composite fiber of Example 3 by 3000 times magnification, (b) is It is a figure which shows the result of having observed the conjugate fiber of Example 3 at a magnification of 10,000 times.

  Hereinafter, embodiments of the present invention will be described in detail. However, the present invention is not limited to this, and can be implemented in a mode in which various modifications are added within the range described. Unless otherwise specified in this specification, “A to B” indicating a numerical range means “A or more and B or less”.

<Method for producing inorganic particle composite fiber>
The method for producing an inorganic particle composite fiber according to one aspect of the present invention comprises a beating step of beating a polar chemical fiber in a wet or dry manner, and synthesizing inorganic particles in a slurry containing the chemical fiber after the beating step. A composite fiber generation step of generating a composite fiber of the chemical fiber and the inorganic particles. With the above configuration, an inorganic particle composite fiber of inorganic particles and polar chemical fiber (hereinafter referred to as “polar chemical fiber”) can be generated without adding a fixing agent. Therefore, according to the method for producing an inorganic particle composite fiber according to one aspect of the present invention, the function of inorganic particles (for example, flame retardancy, deodorization / antibacterial, radiation shielding properties, etc.) is effectively imparted to polar chemical fibers can do.

  Furthermore, by using the above-described configuration, an inorganic particle composite fiber containing a larger amount of inorganic particles (high ash content inorganic particle composite fiber) is used compared to the case where non-beaten polar chemical fibers are used for the generation of composite fibers. ) Can be manufactured. Since the inorganic particle composite fiber in which a larger number of inorganic particles are combined has a greater characteristic due to the inorganic particles, it is possible to produce an inorganic particle composite fiber having a further improved desired function.

  In addition, by using the above-described configuration, compared with the case where polar chemical fibers that have not been beaten are used for the production of composite fibers, the composite efficiency of inorganic particles is improved, so the yield in the production of inorganic particle composite fibers is increased. improves. In the present specification, the “inorganic particle composite fiber” may be simply referred to as “composite fiber”.

  The method for producing an inorganic particle composite fiber according to one embodiment of the present invention can be applied to the production of inorganic particle composite fibers having various ash contents, but the high ash that cannot be produced by the conventional method. The present invention can be particularly suitably applied when producing a minute amount of inorganic particle composite fiber. For example, an inorganic particle composite fiber of polar chemical fiber having an ash content (% by weight) of 5% by weight or more, and further 10% by weight or more can be produced. The calculation method of the ash content (% by weight) of the inorganic particle composite fiber will be described in detail in Examples described later.

  Furthermore, the method for producing an inorganic particle composite fiber according to one embodiment of the present invention can be applied to the production of inorganic particle composite fibers having various coverage ratios, but cannot be produced by a conventional method. This method can be particularly suitably applied when producing a high coverage inorganic particle composite fiber. For example, an inorganic particle composite fiber of polar chemical fiber having a coverage (%) of 15% or more, and further 20% or more can be produced. The coverage (%) refers to the coverage (area ratio) of the fibers with inorganic particles. The coverage can be calculated by confirming the inorganic particle composite fiber with an electron microscope.

[1. Beating process)
In the beating process, the polar chemical fiber is beaten in a wet or dry manner. Details of the polar chemical fiber will be described later. In the beating process, a process equivalent to beating normally performed on pulp fibers may be performed on polar chemical fibers. Examples of the method for beating polar chemical fibers include mechanically (mechanically) treating polar chemical fibers using a known beating machine. As a beating machine, a beating machine usually used when beating pulp fibers can be used also when beating polar chemical fibers. For example, Niagara beater, PFI mill, disc refiner, conical refiner, ball mill , Stone mill, sand grinder mill, impact mill, high pressure homogenizer, low pressure homogenizer, dyno mill, ultrasonic mill, kanda grinder, attritor, vibration mill, cutter mill, jet mill, disaggregator, household juicer mixer, mortar. Among these, a Niagara beater, a disc refiner, or a conical refiner can be preferably used.

  In the beating process, beating can be performed by a wet method or a dry method. Here, in the present specification, the “wet” refers to the case where the object to be subjected to the beating process is a slurry of polar chemical fiber, and the “dry type” refers to the polar chemical fiber in which the object to be subjected to the beating process is not a slurry. Refers to a case. For example, “dry” beating includes a form in which a polar chemical fiber that is not present in a liquid is mechanically (mechanically) processed using the above-described beating machine or the like. In the case of “wet”, the liquid component in the slurry subjected to the beating process includes water, but it may be a liquid other than water or a mixed liquid of water and another liquid. In the present specification, the “slurry” may be a suspension containing polar chemical fibers, and the viscosity, solid content concentration, and the like are not particularly limited.

  The treatment conditions in the beating step can be applied to the case of beating the polar chemical fiber, which is usually applied when beating the pulp fiber. For example, in the case of wet processing, beating treatment is preferably performed by adding water to the polar chemical fiber so that the concentration of the polar chemical fiber in the slurry is 0.1 wt% to 50 wt%. It is more preferable to treat the concentration of the polar chemical fiber in the range of 0.5 to 40% by weight, and it is more preferable to treat the concentration as 1 to 30% by weight.

  The beating may be performed batchwise or continuously. In a preferred embodiment, the slurry containing polar chemical fibers is beaten continuously while flowing. Thereby, the beating of the polar chemical fiber can be performed efficiently.

  When beating, various auxiliaries can be added. Here, the auxiliary agent may be either an organic substance or an inorganic substance, and may be used in combination. Examples of organic substances include surfactants and softeners. Examples of inorganic substances include beads or balls made of glass, alumina, zirconia, and the like, and minerals such as calcium carbonate and magnesium carbonate. By adding these, changes in physical properties of the fiber surface or the entire fiber are promoted, so that the effect of beating can be further enhanced.

  Normally, when beating a pulp fiber, it is known that the pulp fiber after beating undergoes physical changes such as fiber cutting, fibrillation and reduced freeness compared to before beating. ing. However, in the beating process in the method of the present invention, the action of mechanically treating the polar chemical fiber is important, and as a result of this mechanical treatment, the polar chemical fiber after the beating process is physically treated as described above. It does not particularly matter whether or not a change is occurring. That is, the polar chemical fiber after the beating process may have a physical change such as a change in fiber shape, fiber cutting, fibrillation, a decrease in freeness, and a significant change on the surface. It does not have to be. For example, in the examples described later, lyocell (registered trademark), which is a polar regenerated cellulose fiber, is beaten, but when observed at the electron microscope level, lyocell (registered trademark) is fibrillated after the beating step. It was. Thus, when fibrillation occurs in the polar chemical fiber by beating, it is preferable because the surface area of the inorganic particles can be increased by increasing the surface area of the fiber. However, like the polyester fiber used in the examples described later, depending on the type of polar chemical fiber used, fibrillation does not occur by beating, and there may be no significant change in the surface area of the fiber before and after the beating process. obtain. However, even in such a case, surprisingly, the polyester fiber that has undergone the beating process was able to compound more inorganic particles than the polyester fiber that had not undergone the beating process.

  In one embodiment of the present invention, when a fiber (for example, lyocell (registered trademark), etc.) that can be fibrillated by beating is selected as the polar chemical fiber, in the beating step, a Canadian standard measured based on JIS P 8121: 1995. What is necessary is just to beat so that a freeness (Canadian Standard freeness: CSF) may become a predetermined | prescribed numerical value. As the fiber becomes more fibrillated by beating, the water drainage state of the fiber is lowered and the freeness is lowered. Since the freeness of the polar chemical fiber used for the synthesis of the composite fiber is not particularly limited, in the beating step, beating may be performed so that the freeness is less than the freeness of the unbeaten polar chemical fiber. In the present specification, even when “Canada standard freeness” or “CSF” is simply described, it indicates a value measured based on JIS P 8121: 1995.

  In a preferred embodiment, in the beating step, polar chemical fibers are beaten so that the Canadian standard freeness (CSF) is in the range of 10 mL or more and 760 mL or less. In a preferred embodiment, beaten so that the Canadian standard freeness is 50 mL or more and 760 mL or less, more preferably 100 mL or more and 760 mL or less. By beating the polar chemical fiber so that the Canadian standard freeness becomes 760 mL or less, the shape of the polar chemical fiber can be changed. Moreover, by beating the polar chemical fiber, not only the shape change but also the surface area may be increased. By beating the polar chemical fiber so that the Canadian standard freeness becomes 10 mL or more, the resulting composite fiber can be drained well, and such composite fiber is excellent in handleability.

Within the above CSF range, it is preferable to beat so that ΔCSF (mL) representing the amount of change in CSF of the polar chemical fiber before and after beating becomes a predetermined numerical value. Here, ΔCSF can be expressed as a value obtained by subtracting the freeness of the CSF of the polar chemical fiber after the beating process from the CSF of the polar chemical fiber before the beating process, and is calculated from the following formula (1):
ΔCSF (mL) = (CSF of polar chemical fiber before beating process) − (CSF of polar chemical fiber after beating process) (1)
In a preferred embodiment, in the beating step, it is preferable to beat polar chemical fibers so that ΔCSF is preferably 5 mL or more, more preferably 10 mL or more, and even more preferably 15 mL or more. The shape of the polar chemical fiber can be changed by beating the polar chemical fiber so that ΔCSF is 5 mL or more. Moreover, by beating the polar chemical fiber, not only the shape change but also the surface area may be increased.

  Moreover, although mentioned later for details, in a composite fiber production | generation process, a multiple types of raw material substance may be made to react and an inorganic particle may be synthesize | combined. In such a case, the polar chemical fiber can be beaten in the beating step before the composite fiber generating step in the presence of some kinds of raw material substances among a plurality of kinds of raw material substances. Thereby, more inorganic particles can be combined with the fiber. This is because, by beating the polar chemical fiber in the presence of the raw material used to synthesize the inorganic particles, the opportunity for physical contact between the raw material and the polar chemical fiber is increased. This is probably because the inorganic particles are synthesized using the raw material material physically attached to the core as the core.

  The method for beating the polar chemical fiber in the presence of the raw material is not particularly limited, but as one preferred embodiment, for example, some types of raw materials among a plurality of types of raw materials in a slurry containing polar chemical fibers Substances may be added and the slurry may be beaten.

  In addition, when adding some kinds of raw material substances among a plurality of kinds of raw material substances to the slurry containing polar chemical fibers, as the “partial kinds of raw material substances”, an alkaline raw material substance or an acidic raw material substance is used. At least one of the raw materials can be included. By adding either an alkaline raw material or an acidic raw material to the slurry used for the beating step, polar chemical fibers can be beaten efficiently. As a result, in the subsequent composite fiber production step, inorganic particles and Composite fibers with polar chemical fibers can be obtained. As for the “some types of raw material”, whichever of the alkaline raw material or the acidic raw material is added, an appropriate one is selected depending on the type of polar chemical fiber, the type of inorganic particles to be synthesized, etc. Just choose.

  The “alkaline raw material” is, for example, barium hydroxide used for synthesizing barium sulfate. The “acidic source material” is, for example, aluminum sulfate used for synthesizing barium sulfate. A beating step can be performed after a predetermined time has elapsed after mixing either an alkaline raw material or an acidic raw material with a slurry containing polar chemical fibers, but the beating step may be performed immediately after mixing.

[2. Composite fiber production process)
A composite fiber production | generation process is a process of producing | generating the composite fiber of a polar chemical fiber and an inorganic particle. In the composite fiber generation step, inorganic particle composite fibers are generated by synthesizing inorganic particles in a slurry containing polar chemical fibers after the beating step. In a preferred embodiment, in the composite fiber generation step, a composite fiber is generated using polar chemical fibers having a Canadian standard freeness of 10 mL or more and 760 mL or less after the beating step.

(Inorganic particles)
The type of inorganic particles synthesized in the composite fiber generation step (that is, inorganic particles combined with polar chemical fibers) can be appropriately selected according to the purpose. In the composite fiber production step, the inorganic particles may be synthesized in an aqueous system, and the composite fibers may be used in an aqueous system. Therefore, the inorganic particles are preferably insoluble or hardly soluble in water.

An inorganic particle refers to the particle | grains of an inorganic compound, for example, a metal compound is mentioned. The metal compound refers to 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 ₅ ²⁻ , SiO ₃ ²⁻ , Cl ⁻ , F ⁻ , S ^{2−, and the} like), which are generally called inorganic salts Say. Specific examples of the inorganic particles include, for example, one or more selected from the group consisting of gold, calcium, silicic acid, magnesium, barium, aluminum, titanium, copper, silver, zinc, platinum, iron, palladium, and zirconium. Compounds. Also, calcium carbonate (light calcium carbonate, heavy calcium carbonate), magnesium carbonate, barium carbonate, aluminum hydroxide, calcium hydroxide, barium sulfate, magnesium hydroxide, zinc hydroxide, calcium phosphate, zinc oxide, zinc stearate, dioxide dioxide Examples thereof include silica (white carbon, silica / calcium carbonate composite, silica / titanium dioxide composite), calcium sulfate, zeolite, and hydrotalcite produced from titanium, sodium silicate and mineral acid. 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. The inorganic particles exemplified above may be used alone or in combination of two or more in the solution containing fibers as long as they do not inhibit the reactions that synthesize each other.

  When the inorganic particles in the composite fiber are hydrotalcite, it is more preferable that at least one of magnesium and zinc is contained in an ash content of the composite fiber of hydrotalcite and polar chemical fiber by 10% by weight or more.

  In one embodiment of the present invention, the inorganic particles may include at least one compound selected from the group consisting of calcium carbonate, magnesium carbonate, barium sulfate, and hydrotalcite.

(Synthesis method of inorganic particles)
The method for synthesizing the inorganic particles is not particularly limited, and can be synthesized by a known method. Moreover, the synthesis method of inorganic particles 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. In addition, calcium carbonate can be synthesized by a carbon dioxide method in which calcium hydroxide and carbon dioxide are reacted. For example, calcium carbonate may be synthesized by a soluble salt reaction method, a lime / soda method, or a soda method. Magnesium carbonate can also be synthesized by adding sodium carbonate or potassium carbonate to an aqueous magnesium salt solution. Examples of liquid-liquid methods include reacting acid (hydrochloric acid, sulfuric acid, etc.) and base (sodium hydroxide, potassium hydroxide, etc.) by neutralization, reacting inorganic salt with acid or base, The method of making it react is mentioned. For example, barium sulfate can be obtained by reacting barium hydroxide with sulfuric acid. By reacting barium hydroxide with aluminum sulfate (sulfate band), not only barium sulfate but also aluminum compounds such as aluminum hydroxide can be obtained. Aluminum hydroxide can be obtained by reacting aluminum chloride or aluminum sulfate with sodium hydroxide. By reacting calcium carbonate and aluminum sulfate, inorganic particles in which calcium and aluminum are combined 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.

  When two or more kinds of inorganic particles are combined with polar chemical fibers, after one kind of inorganic particles is synthesized in the presence of polar chemical fibers, the synthesis reaction is stopped and another kind of inorganic particles is used. Synthetic reaction of inorganic particles may be performed, or two or more types of inorganic particles may be synthesized at the same time when the reactions do not interfere with each other or when multiple types of target inorganic particles are synthesized in one reaction. . Also, seed crystals can be added before or during the synthesis reaction. By adding seed crystals, the growth of inorganic particles can be promoted, or the particle size can be easily controlled.

The reaction conditions (temperature of the reaction solution, pH of the reaction solution, conductivity of the reaction solution, reaction time, etc.) in the composite fiber generation step are not particularly limited, and can be set as appropriate according to the type of inorganic particle synthesis reaction. . The reaction efficiency can be improved by conducting the synthesis reaction of inorganic particles while stirring the reaction solution. The synthesis reaction of the inorganic particles may be a batch reaction or a continuous reaction.
As one preferred embodiment, the average primary particle diameter of the inorganic particles in the composite fiber can be set to 5 μm or less, for example, but the average primary particle diameter is 3 μm or less, the average primary particle diameter is 1 μm or less. Inorganic particles having an average primary particle diameter of 200 nm or less, 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 diameter can be calculated from an electron micrograph.

  By adjusting the conditions for synthesizing the inorganic particles, the inorganic particles having various sizes and shapes can be made into composite fibers with fibers. For example, a composite fiber in which scale-like inorganic particles are combined with a fiber can also be used. The shape of the inorganic particles constituting the composite fiber can be confirmed by observation with an electron microscope.

  In addition, the inorganic particles may take the form of secondary particles in which fine primary particles are aggregated, and secondary particles may be generated according to the application by an aging process, and the aggregates are made fine by pulverization. May be. 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.

(Polar chemical fiber)
Chemical fiber refers to all fibers produced by chemical processes. Specific examples include conventionally known synthetic fibers and regenerated fibers (semi-synthetic fibers). A polar chemical fiber will not be specifically limited if it is a chemical fiber which has polarity, According to a use, it can select suitably. Examples of the polar chemical fiber include a polar group (for example, a hydroxyl group (—OH), a carboxyl group (—COOH), an amino group (—NH ₂ ), an aldehyde group, a phosphate group, a urea group, and a sulfo group in the molecule. , A nitro group, an amide group, a cyano group, a carbonyl group (—COO—), an ether group (—O—), a silanol group, etc.) and the surface is modified with these functional groups. Synthetic fibers (including those in which the surface of nonpolar synthetic fibers is modified with these functional groups).

  As specific examples of the polar chemical fiber, examples of the synthetic fiber include polyester fiber, polyamide fiber, acrylic fiber, polyurethane fiber, polyvinyl alcohol fiber, and polyvinyl chloride. Examples of the semisynthetic fiber include regenerated cellulose fiber and acetate. Examples of the polyester fiber include polyethylene terephthalate (PET) fiber, polytrimethylene terephthalate (PTT) fiber, and polybutylene terephthalate (PBT) fiber. Examples of polyamide fibers include nylon fibers and aramid fibers.

  In a preferred embodiment, the polar chemical fiber is one or more chemical fibers selected from the group consisting of regenerated cellulose fiber, polyester fiber, polyamide fiber, and acrylic fiber. Since these polar chemical fibers are excellent in heat resistance, strength, etc., it is useful to produce a composite fiber in which these polar chemical fibers are given the function of inorganic particles. Examples of the regenerated cellulose fiber include lyocell (registered trademark), rayon, and cupra (registered trademark). The degree of polymerization of the cellulose molecules constituting the regenerated cellulose fiber is not particularly limited and can be appropriately selected according to the purpose. Among the regenerated cellulose fibers, in particular, Lyocell (registered trademark) is excellent in strength, and can be suitably used as a nonwoven fabric material. For this reason, it is useful if a high ash content lyocell (registered trademark) composite fiber can be produced.

  About the fiber illustrated above, you may use individually or in combination of 2 or more types.

  Moreover, the fiber length of the polar chemical 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. .

The amount of polar chemical fiber contained in the slurry used in the composite fiber production process (that is, the amount of polar chemical fiber used for synthesizing the composite fiber) covers 15% or more of the surface of the polar chemical fiber with inorganic particles. It is preferable that the amount be as follows. For example, the weight ratio between the polar chemical fiber and the inorganic particles in the inorganic particle composite fiber obtained by the composite fiber generation step is preferably 5/95 to 95/5, and preferably 10/90 to 90. / 10, 20/80 to 80/20, 30/70 to 70/30, or 40/60 to 60/40.
(Other substances)
In one embodiment of the present invention, the slurry in the composite fiber production step may contain substances other than the polar chemical fiber, the inorganic particles, and the raw material used for the synthesis of the inorganic particles. For the slurry in the composite fiber production step, known various auxiliary agents (for example, chelating agents, surface treatment agents, dispersing agents, etc., flocculants, coagulants, retention agents, bleaching agents, bactericides, sizes) Agent) and the like. Various auxiliary agents can be used alone or in combination. Moreover, the timing in particular of adding various adjuvants to a slurry is not restrict | limited. Various auxiliaries can be added to the inorganic particles in an amount of preferably 0.001 wt% to 20 wt%, more preferably 0.01 wt% to 10 wt%.

<Inorganic particle composite fiber>
Inorganic particle composite fibers manufactured by the method for manufacturing inorganic particle composite fibers according to the present invention are also included in the scope of the present invention. In the inorganic particle composite fiber of the polar chemical fiber and the inorganic particles, the polar chemical fiber and the inorganic particles are not simply mixed, but the polar chemical fiber and the inorganic particles are combined by hydrogen bonding or the like. Inorganic particles are difficult to fall off from polar chemical fibers. Such a composite fiber can be suitably used for various applications because the yield of inorganic particles is high, and even if the ash content is high, powder falling is suppressed.

  The inorganic particle composite fiber manufactured by the method for manufacturing an inorganic particle composite fiber according to one embodiment of the present invention can be a composite fiber of a high ash polar chemical fiber that cannot be obtained by a conventional method. For example, the inorganic particle composite fiber produced in one embodiment of the present invention can be an inorganic particle composite fiber of polar chemical fiber having an ash content (wt%) of 5 wt% or more, and further 10 wt% or more.

  Furthermore, the inorganic particle composite fiber manufactured by the method for manufacturing an inorganic particle composite fiber according to one aspect of the present invention can be a composite fiber of a high coverage polar chemical fiber that cannot be obtained by a conventional method. For example, the inorganic particle composite fiber manufactured in one embodiment of the present invention has an inorganic particle composite of polar chemical fibers having a fiber coverage (area ratio) (%) of 15% or more, further 20% or more. Can be a fiber.

  Furthermore, since the inorganic particle composite fiber manufactured by the method for manufacturing an inorganic particle composite fiber according to one embodiment of the present invention has an improved composite ratio of the inorganic particles, a sheet of such inorganic particle composite fiber is made by paper. Yield can be improved. As a result, the sheet manufacturing speed (for example, the wire speed of the paper machine) can be improved.

  In one preferred embodiment, the inorganic particle composite fiber is a composite fiber of inorganic particles and a polar chemical fiber having a Canadian standard freeness of 10 mL or more and 760 mL or less based on JIS P 8121: 1995.

  In one preferred embodiment, the inorganic particle composite fiber is an inorganic particle composite fiber of one or more polar chemical fibers selected from the group consisting of regenerated cellulose fiber, polyester fiber, polyamide fiber and acrylic fiber.

[Use]
The inorganic particle composite fiber manufactured by the method for manufacturing an inorganic particle composite fiber according to the present invention can be used for various applications. For example, paper, non-woven fabric, fiber, cellulosic composite material, filter material, paint, plastic, other resin, rubber, elastomer, ceramic, glass, tire, building material (asphalt, asbestos, cement, board, concrete, brick, tile , Plywood, fiberboard, etc.), various carriers (catalyst carriers, pharmaceutical carriers, agricultural chemical carriers, microbial carriers, etc.), adsorbents (impurities removal, deodorization, dehumidification, etc.), wrinkle inhibitors, clays, abrasives, modifiers Repair materials, heat insulation materials, moisture proof materials, water repellent materials, water resistant materials, light shielding materials, sealants, shield materials, insect repellents, adhesives, inks, 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, insulation materials, sound insulation materials, anti-vibration materials, semiconductor encapsulants, Radiation shielding material Widely used in various applications such as products, fertilizers, feeds, fragrances, additives for paints / adhesives, flame retardant materials, sanitary products (disposable diapers, sanitary napkins, incontinence pads, breast milk pads, etc.) be able to. Moreover, it can use for articles | goods, such as various fillers and coating agents in the said use.

  The article including an inorganic particle composite fiber manufactured by the method for manufacturing an inorganic particle composite fiber according to one aspect of the present invention is also included in the scope of the present invention. Moreover, use of the said inorganic particle composite fiber for manufacture of the said article is also contained in the scope of the present invention.

[Summary]
The present invention includes, but is not limited to, the following inventions.
(1) A beating step of beating polar chemical fibers in a wet or dry manner, and synthesizing inorganic particles in a slurry containing the chemical fibers after the beating step, producing a composite fiber of the chemical fibers and the inorganic particles A method for producing an inorganic particle composite fiber.
(2) The inorganic particle composite fiber is a composite fiber of the inorganic particle and the chemical fiber having a Canadian standard freeness based on JIS P 8121: 1995 of 10 mL or more and 760 mL or less. The manufacturing method of inorganic particle composite fiber.
(3) In the said beating process, the said chemical fiber is beaten so that (DELTA) CSF calculated from following formula (1) may be 5 mL or more, The manufacturing method of the inorganic particle composite fiber as described in (1) or (2) :
ΔCSF (mL) = Canadian standard freeness of polar chemical fiber before beating process-Canadian standard freeness of polar chemical fiber after beating process (1)
(In the above formula (1), the Canadian standard freeness is a value measured based on JIS P 8121: 1995).
(4) The chemical fiber according to any one of (1) to (3), wherein the chemical fiber is one or more chemical fibers selected from the group consisting of regenerated cellulose fiber, polyester fiber, polyamide fiber, and acrylic fiber. The manufacturing method of inorganic particle composite fiber.
(5) At least a part of the inorganic particles includes one or more selected from the group consisting of calcium, silicic acid, magnesium, barium, aluminum, titanium, copper, silver, zinc, platinum, iron, palladium, and zirconium. The manufacturing method of the inorganic particle composite fiber as described in any one of (1)-(4).
(6) The manufacturing method of the inorganic particle composite fiber as described in any one of (1)-(5) whose average primary particle diameter of the said inorganic particle in the said inorganic particle composite fiber is 5 micrometers or less.
(7) The inorganic particle composite fiber according to any one of (1) to (6), wherein 15% or more of the surface of the chemical fiber is covered with the inorganic particle. Method.
(8) The inorganic particle according to any one of (1) to (7), wherein a weight ratio of the chemical fiber to the inorganic particle in the inorganic particle composite fiber is 5/95 to 95/5. A method for producing a composite fiber.
(9) In the composite fiber generation step, a plurality of types of raw materials are reacted to synthesize the inorganic particles, and in the beating step, the plurality of types used to synthesize the inorganic particles in the composite fiber generation step. The method for producing an inorganic particle composite fiber according to any one of (1) to (8), wherein the chemical fiber is beaten in the presence of a part of the raw material materials.
(10) An inorganic particle composite fiber of inorganic particles and polar chemical fiber having a Canadian standard freeness based on JIS P 8121: 1995 of 10 mL or more and 760 mL or less.
(11) The inorganic particle composite fiber according to (10), wherein the chemical fiber is one or more chemical fibers selected from the group consisting of regenerated cellulose fiber, polyester fiber, polyamide fiber, and acrylic fiber.
(12) At least a part of the inorganic particles includes one or more selected from the group consisting of calcium, silicic acid, magnesium, barium, aluminum, titanium, copper, silver, zinc, platinum, iron, palladium, and zirconium. The inorganic particle composite fiber according to (10) or (11).
(13) The inorganic particle composite fiber according to any one of (10) to (12), wherein an average primary particle diameter of the inorganic particles in the inorganic particle composite fiber is 5 μm or less.
(14) The inorganic particle composite fiber according to any one of (10) to (13), wherein 15% or more of the surface of the chemical fiber is covered with the inorganic particle.
(15) The inorganic particle according to any one of (10) to (14), wherein a weight ratio of the chemical fiber and the inorganic particle in the inorganic particle composite fiber is 5/95 to 95/5. Composite fiber.

  The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope shown in the claims, and embodiments obtained by appropriately combining technical means disclosed in different embodiments. Is also included in the technical scope of the present invention.

Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the examples.

[Example 1: Synthesis of composite fiber of barium sulfate and polar chemical fiber]
As a polar chemical fiber, Lyocell (registered trademark) (manufactured by LENZING, fiber length: 4 mm) was used. A slurry containing Lyocell (registered trademark) (fiber concentration: 1% by weight, solid content: 200 g) and barium hydroxide octahydrate (Wako Pure Chemical Industries, 368 g) were supplied to a Niagara Beater (manufactured by Kumagaya Riki Kogyo Co., Ltd.). Lyocell® was beaten for about 10 minutes at room temperature in the presence of barium oxide.

  The Canadian standard freeness (CSF) of Lyocell (registered trademark) after beating was measured based on JIS P 8121: 1995. As a result, the CSF of Lyocell (registered trademark) after beating was 748 mL. On the other hand, the CSF of unbeaten Lyocell (registered trademark) was 769 mL. ΔCSF obtained by subtracting the CSF after beating from the CSF before beating was 21 mL.

  Further, as a result of observing the shape of the fiber with a laser microscope, as shown in FIG. 1, the fiber which was linear before beating ((a) in FIG. 1) was cut short after beating and bent in some places. It was. Furthermore, it was confirmed that many external fibrils were generated ((b) of FIG. 1).

  500 g of the slurry after beating was transferred to a 1 L plastic cup, and sulfuric acid (Wako Pure Chemicals, 5% aqueous solution) was added dropwise at 1.2 g / min until pH reached 7 while stirring at a speed of 600 rpm with a three-one motor ( The pH before adding sulfuric acid was 12.8). After completion of dropping, stirring was continued for 30 minutes to obtain a composite fiber slurry of Example 1. As mentioned above, in Example 1, the composite fiber of barium sulfate and Lyocell (registered trademark) is synthesized.

[Example 2: Synthesis of composite fiber of barium sulfate and polar chemical fiber]
A composite fiber slurry of Example 2 was obtained in the same manner as Example 1 except that polyester fiber (EP043, manufactured by Kuraray Co., Ltd.) was used as the polar chemical fiber.

  As a result of CSF measurement of the polyester fiber after beating, the CSF of the polyester fiber after beating was 752 mL. On the other hand, the CSF of unbeaten polyester fiber was 773 mL. ΔCSF obtained by subtracting the CSF after beating from the CSF before beating was 21 mL.

  Also, as a result of observing the shape of the fiber with a laser microscope, as shown in FIG. 2, the shape of the fiber that was linear before beating ((a) in FIG. 2) was bent or crushed in some places after beating. (Fig. 2 (b)). Although fibrils were not generated in the beaded polyester fiber, it was considered that one reason for the decrease in CSF after beating was that the structure of the fiber was softened by beating and water retention was increased. In addition, from the observation result with a laser microscope, the shape was changed from a linear type to a bent type, so that the change in the shape of the fiber increased the entanglement between the fibers and increased the freeness. it was thought.

[Example 3: Synthesis of composite fiber of barium sulfate and polar chemical fiber]
When beating the polyester fiber, no barium hydroxide is added. After beating, the polyester fiber (500 g) is transferred to the reaction vessel and barium hydroxide octahydrate (Wako Pure Chemicals, 9.2 g) is added. The mixture was stirred at (600 rpm). Thereafter, a composite fiber slurry of Example 3 was obtained in the same manner as in Example 2.

[Comparative Example 1: Synthesis of composite fiber of barium sulfate and polar chemical fiber]
A composite fiber slurry of Comparative Example 1 was obtained in the same manner as in Example 1 except that Lyocell (registered trademark) was not beaten.

[Comparative Example 2: Synthesis of composite fiber of barium sulfate and polar chemical fiber]
A composite fiber slurry of Comparative Example 2 was obtained in the same manner as in Example 2 except that the polyester fiber was not beaten.

≪Evaluation of composite fiber≫
The obtained composite fiber was washed with ethanol, and then the surface of the composite fiber was observed using a scanning electron microscope (SEM). The results are shown in FIGS. FIG. 3 is a view showing the observation result of the composite fiber produced in Example 1 and Comparative Example 1 by a scanning electron microscope, and FIG. 4 is the scan electron of the composite fiber produced in Example 2 and Comparative Example 2. It is a figure which shows the observation result by a microscope. 3 and 4, (a) is a diagram showing the result of observing the composite fiber of the comparative example at a magnification of 3000 times, and (b) is a diagram showing the result of observing the composite fiber of the comparative example at a magnification of 10000 times. (C) is a figure which shows the result of having observed the composite fiber of the Example by 3000 times of magnification, (d) is a figure which shows the result of having observed the composite fiber of the Example by 10,000 times of magnification.

  FIG. 5 is a diagram showing the observation result of the composite fiber produced in Example 3 with a scanning electron microscope, and (a) is a diagram showing the result of observing the composite fiber of the Example at a magnification of 3000 times. (B) is a figure which shows the result of having observed the conjugate fiber of the Example at the magnification of 10,000 times.

<< Result 1: Example 1 and Comparative Example 1 >>
As shown in FIG. 3, as a result of observation, the surface of both the composite fiber of Example 1 and the composite fiber of Comparative Example 1 is covered with an inorganic substance, and the inorganic substance is self-fixed on the fiber. Was observed. Most of the inorganic particles fixed on the fiber were plate-like, and those having a small size were observed as amorphous particles. Moreover, the primary particle diameter of the inorganic particle estimated as a result of observation was 50 to 300 nm, and the average primary particle diameter was about 150 nm. In the composite fiber of Example 1, compared with the composite fiber of Comparative Example 1, an increase in fibrils due to beating was observed.

  About the obtained composite fiber, the coverage (area ratio) of the lyocell (trademark) by the inorganic particle was measured by observation by SEM. As a result, in the conjugate fiber of Example 1, the coverage was 20%. On the other hand, in the composite fiber of Comparative Example 1, the coverage was 15%.

  About the obtained composite fiber, the weight ratio of the fiber: inorganic particles was measured. The weight ratio (ash content) was determined by using a dynamic freeness tester (DDA, manufactured by Ab Akribi Kemikonsulter), stirring the composite fiber slurry (0.5 g in terms of solid content) at 800 rpm, and then a pressure of 0.3 bar. Then, the residue was dried in an oven (105 ° C., 2 hours), the organic content was burned at 525 ° C., and the weight was calculated from before and after combustion. As a result, in the composite fiber of Example 1, the weight ratio of fiber: inorganic particles was 86:14 (ash content: 14%). On the other hand, in the composite fiber of Comparative Example 1, the weight ratio of fiber: inorganic particles was 91: 9 (ash content: 9% by weight).

  From the above results, by using the lyocell (registered trademark) that has undergone the beating process for the synthesis of the composite fiber, compared to the case of using lyocell (registered trademark) that has not undergone the beating process for the synthesis of the composite fiber, It became clear that a composite fiber to which many inorganic particles were attached could be produced.

<< Result 2: Example 2 and Comparative Example 2 >>
As shown in FIG. 4, as a result of observation, both the composite fiber of Example 2 and the composite fiber of Comparative Example 2 have a fiber surface covered with an inorganic substance, and the inorganic substance is self-fixed on the fiber. Was observed. Most of the inorganic particles fixed on the fiber were plate-like, and those having a small size were observed as amorphous particles. Moreover, the primary particle diameter of the inorganic particle estimated as a result of observation was 50 to 300 nm, and the average primary particle diameter was about 150 nm. In the conjugate fiber of Example 2, as compared with the conjugate fiber of Comparative Example 2, no increase in fibrils due to beating was observed.

  About the obtained composite fiber, the coverage of the fiber by an inorganic particle (area ratio) was 85% in the composite fiber of Example 2. On the other hand, in the composite fiber of Comparative Example 2, the coverage was 10%.

  The weight ratio of fiber: inorganic particles was 91: 9 for the composite fiber of Example 2 (ash content: 9% by weight). On the other hand, in the composite fiber of Comparative Example 2, the weight ratio of fiber: inorganic particles was 96: 4 (ash content: 4% by weight).

  From the above results, more inorganic particles are attached by using polyester fibers that have undergone the beating process for synthesizing the composite fiber than when polyester fibers that have not been subjected to the beating process are used for synthesizing the composite fiber. It has been found that a composite fiber can be produced.

<< Result 3: Example 3 >>
As shown in FIG. 5, as a result of observation, it was observed that the surface of the composite fiber of Example 3 was covered with an inorganic substance, and the inorganic substance was self-fixed on the fiber. Most of the inorganic particles fixed on the fiber were plate-like, and those having a small size were observed as amorphous particles. Moreover, the primary particle diameter of the inorganic particle estimated as a result of observation was 50-300 nm, and the average primary particle diameter was 150 nm.

  About the composite fiber of Example 3, the coverage (area ratio) of the fiber by inorganic particles was 75%. The weight ratio of fiber: inorganic particles was 95: 6 for the composite fiber of Example 3 (ash content: 6% by weight).

  From the above results, in the absence of barium hydroxide, when the polyester fiber is beaten and then the composite fiber is synthesized, the polyester fiber that has not undergone the beating process is used for the synthesis of the composite fiber (Comparative Example) As compared with 2), it has become clear that a composite fiber to which more inorganic particles are attached can be produced.

  According to the manufacturing method of the inorganic particle composite fiber which concerns on 1 aspect of this invention, the fiber which adhered more inorganic substances can be manufactured. Therefore, one embodiment of the present invention is a fiber (in particular, regenerated cellulose fiber, polyester fiber, polyamide fiber, and acrylic fiber) imparted with inorganic particle functions (flame retardant, deodorant / antibacterial property, radiation shielding property, etc.). Can be suitably used in various fields using polar chemical fibers).

Claims (15)

A beating process of beating a chemical fiber of polarity with a wet type or a dry type;
A method for producing an inorganic particle composite fiber, comprising: a composite fiber generation step of generating a composite fiber of the chemical fiber and the inorganic particle, wherein the inorganic particle is synthesized in a slurry containing the chemical fiber after the beating step.   The inorganic particle according to claim 1, wherein the inorganic particle composite fiber is a composite fiber of the inorganic particle and the chemical fiber having a Canadian standard freeness based on JIS P 8121: 1995 of 10 mL or more and 760 mL or less. A method for producing a composite fiber. In the said beating process, the said chemical fiber is beaten so that (DELTA) CSF calculated from following formula (1) may be 5 mL or more: The manufacturing method of the inorganic particle composite fiber of Claim 1 or 2:
ΔCSF (mL) = Canadian standard freeness of polar chemical fiber before beating process-Canadian standard freeness of polar chemical fiber after beating process (1)
(In the above formula (1), the Canadian standard freeness is a value measured based on JIS P 8121: 1995).   The inorganic particle composite fiber according to any one of claims 1 to 3, wherein the chemical fiber is one or more chemical fibers selected from the group consisting of regenerated cellulose fiber, polyester fiber, polyamide fiber, and acrylic fiber. Manufacturing method.   The at least part of the inorganic particles includes one or more selected from the group consisting of calcium, silicic acid, magnesium, barium, aluminum, titanium, copper, silver, zinc, platinum, iron, palladium, and zirconium. The manufacturing method of the inorganic particle composite fiber of any one of 1-4.   The manufacturing method of the inorganic particle composite fiber of any one of Claims 1-5 whose average primary particle diameter of the said inorganic particle in the said inorganic particle composite fiber is 5 micrometers or less.   The said inorganic particle composite fiber is a manufacturing method of the inorganic particle composite fiber of any one of Claims 1-6 with which 15% or more of the surface of the said chemical fiber is covered with the said inorganic particle.   The manufacturing method of the inorganic particle composite fiber of any one of Claims 1-7 whose weight ratio of the said chemical fiber and the said inorganic particle in the said inorganic particle composite fiber is 5 / 95-95 / 5. . In the composite fiber generation step, the inorganic particles are synthesized by reacting a plurality of types of raw material materials,
In the beating step, the chemical fiber is beaten in the presence of some kind of raw material of the plural kinds of raw materials used to synthesize the inorganic particles in the composite fiber generation step. Item 10. A method for producing an inorganic particle composite fiber according to any one of Items 1 to 8.   An inorganic particle composite fiber of inorganic particles and a polar chemical fiber having a Canadian standard freeness based on JIS P 8121: 1995 of 10 mL or more and 760 mL or less.   The inorganic particle composite fiber according to claim 10, wherein the chemical fiber is one or more chemical fibers selected from the group consisting of regenerated cellulose fiber, polyester fiber, polyamide fiber, and acrylic fiber.   The at least part of the inorganic particles includes one or more selected from the group consisting of calcium, silicic acid, magnesium, barium, aluminum, titanium, copper, silver, zinc, platinum, iron, palladium, and zirconium. The inorganic particle composite fiber according to 10 or 11.   The inorganic particle composite fiber according to any one of claims 10 to 12, wherein an average primary particle diameter of the inorganic particles in the inorganic particle composite fiber is 5 µm or less.   14. The inorganic particle composite fiber according to claim 10, wherein 15% or more of the surface of the chemical fiber is covered with the inorganic particle.   The inorganic particle composite fiber according to any one of claims 10 to 14, wherein a weight ratio of the chemical fiber and the inorganic particle in the inorganic particle composite fiber is 5/95 to 95/5.