JP2021084869A - Dough-like particle aggregate, method for manufacturing the same, and sanitary paper - Google Patents

Abstract

To provide: a dough-like particle aggregate which is not subjected to an influence on bactericidal action from pulp that is an organic matter, and which is capable of reducing an influence on a human body as much as possible without deteriorating a bactericidal effect of medicine; and a technology of sanitary paper using the dough-like particle aggregate.SOLUTION: A bactericidal nanocapsule 1 includes: a nuclear fine particle 2 having a nanometer size containing quaternary ammonium salt; a first water-resistant coating layer 11 disposed so as to cover a surface of the nuclear fine particle 2; a second water-resistant coating layer 12 disposed so as to cover a surface of the first coating layer 11; and a third water-resistant coating layer 13 that is cationized and disposed so as to cover a surface of the second coating layer 12.SELECTED DRAWING: Figure 1

Description

The present invention relates to a grape-like fine particle aggregate in which nanocapsules of a drug having a coating layer are attached to nanofibers made of a polymer material such as PP (polypropylene), and a technique for sanitary paper using the same.

In recent years, nanofibers, which have been attracting attention in recent years, are not only used independently based on their own physical characteristics, but also in a wide range of fields such as general-purpose products, filter materials, electronic parts, automobile parts, medical / biomaterials, etc. in the field of composite materials. It is being put to practical use, and application development is being actively carried out.

The main features of nanofibers are 1) supramolecular surface area effect (high adsorptivity, strong adhesive strength, high molecular recognition), 2) nanosize effect (low pressure loss, high transparency), 3) supramolecular effect. The molecular arrangement effect (high strength, high electrical conductivity, high thermal conductivity), etc. are mentioned, and as a material supporting advanced technology, development in a wide range of fields is being actively carried out in various countries around the world (see Non-Patent Document 1). ).

There are several methods for manufacturing nanofibers (spinning method), and each has different target materials, nanofiber fiber diameter, production efficiency per hour, etc., so the spinning method is selected according to the application. Has been done.

The main spinning methods are the electrospinning method in which a polymer is dissolved in a solvent and spun by repulsion of electrostatic force, and only one type is dissolved from a mixture of two types of polymers having a sea-island structure to extract the remaining fine fibers. Examples include a composite melt spinning method, a melt blow method in which a molten resin is stretched with air, and a chemical vapor phase growth (CVD) method in which a carbon oxide and hydrogen gas are reacted in a gas phase. Of these, the melt blow method, which does not require a solvent and is highly safe, is characterized in that nanofibers can be mass-produced at low cost and various resin raw materials can be produced.

On the other hand, the technology for producing microcapsules began with the commercialization of carbonless copy paper in the 1950s, and rapidly developed in the mid-1970s.

Microcapsules are applied in a wide range of fields such as pharmaceuticals, pesticides, foods, paints, inks, and adhesives (see Non-Patent Document 2, Non-Patent Document 3, and Patent Document 1).

The main effects of microencapsulation are morphological stabilization to fix the core material such as liquid, isolation effect to prevent reaction and mixing of surrounding substances and core material, storage effect of core material, shielding of toxicity and odor, etc. It is used in the above-mentioned various applications because of its effects and the effect of suppressing the release of the core material.

Encapsulation techniques are roughly divided into three methods: mechanical method (orifice method), physical method (phase separation method, etc.), and chemical method (interfacial polymerization method, etc.). The material is used.

Conventionally, microcapsules containing bactericidal ingredients, analgesic ingredients, deodorant ingredients, fragrance ingredients, antioxidant ingredients, skin care ingredients, etc. have been used in various fields such as sanitary papers, poultices, air fresheners, deodorants, and pesticides. (Refer to Patent Documents 2 to 4 and the like).

Among the various components, a cationic surfactant (quaternary ammonium salt) is currently used as a disinfectant in a wide range of fields. The positively charged cationic surfactant has an excellent feature that the adsorption rate to the negatively charged bacterial surface is high and a rapid bactericidal effect is exhibited.

It has been reported that there are two actions as the mechanism of action of quaternary ammonium salts.

One is "physical destruction of the cell membrane", which is an action in which the cation of the ammonium molecule binds to the anion site on the bacterial surface and physically destroys the cell membrane by hydrophobic interaction (Non-Patent Document 5). .. The other is "inhibition of metabolic function of bacteria", in which quaternary ammonium salts strongly adsorb to bacteria and inhibit intracellular enzymes, thereby suppressing and inhibiting metabolic function (growth). (Non-Patent Document 6).

Conventionally, various microencapsulation techniques containing bactericidal ingredients, analgesic ingredients, deodorant ingredients, fragrance ingredients, antioxidant ingredients, skin care ingredients, etc. have been studied and put into practical use, but the main techniques have already been described. As described above, a mechanical method (opero method, etc.), a physical method (phase separation method, etc.), and a chemical method (interfacial polymerization method, etc.) can be mentioned.

Among these microencapsulation techniques, in the orifice method, a polymer solution containing various components (core substances) is dropped from a double tube into a curing liquid to prepare microcapsules.

In the phase separation method, the core material that needs to be wrapped is dispersed in an organic solution containing a wall material to wrap and cover the periphery of the core material. At that time, the pH value, concentration, temperature, etc. of the solution are determined. It is necessary to adjust the conditions and gradually deposit the wall material on the surface of the capsule core.

In the interfacial polymerization method, microcapsules are produced by causing a polymerization reaction at the interface between a hydrophobic organic solvent containing a core substance and water.

The above-mentioned microencapsulation technique has a problem that the process is complicated and mass production is difficult in industrial production.

In recent years, there has been a demand for a new functional composite material (element) using the above-mentioned nanofibers as an alternative to such microcapsules, but it has not yet been realized.

On the other hand, conventionally, as sanitary paper having a bactericidal component, wet wet paper or the like impregnated with an aqueous solution of alcohol, sodium hypochlorite or the like has been commercially available.

In the 70-year history of sanitary paper, the only product that has a bactericidal effect is wet tissue made of non-woven fabric, and no product that has a bactericidal effect of dry tissue made of pulp has ever been born. ..

The main cause is that the pulp, which is the material of the tissue, is an organic substance, so that the effectiveness of commonly used fungicides (quaternary ammonium salts, etc.) is reduced, and the concentration is also reduced by being adsorbed by the fibers ( Since Non-Patent Document 4), the bactericidal action of the bactericide is significantly reduced (the bactericidal effect is reduced by 80-90%).

A commonly used disinfectant wet tissue has a disinfectant concentration of 1000 ppm and a disinfectant rate of 90% or more.

As the wet tissue, a non-woven fabric (polypropylene or the like) having excellent chemical resistance and no hygroscopicity is used, and the non-woven fabric is produced by immersing the non-woven fabric in a chemical solution adjusted to a constant concentration (1000 ppm).

Wet wipes for disinfection are effective because the chemicals seep out of the non-woven fabric when used, so a considerable excess of the chemicals is used.

In such wet sanitary paper, for example, 1.7 tons of chemical solution (drug concentration 1000 ppm) is used for 1 ton of non-woven fabric. Although this chemical solution has a bactericidal effect, it is an unfavorable component for the human body, and although it is desired to reduce it as much as possible, it has been difficult to reduce the chemical solution.

In addition, since the chemical solution is impregnated, the weight of the product becomes heavy, and once the product provided in the sealed state is opened, the shelf life is shortened. Furthermore, since the paper is impregnated with an aqueous solution, there is a problem that a component that is insoluble in water cannot be used.

2015 Patent Application Technology Trend Survey Report "Nanofiber": Japan Patent Office "Micro-encapsulation": Wikipedia February 2008 Survey Report "Microcapsules": Toray Research Center September 2013 "Disinfectant Use Guidelines 2015", J Infection Control Network Edition "Antibacterial fungicide": Hiroki Korai 1995, Vol.23 "Chemistry of antibacterial and antifungal": Hiroshi Horiguchi, Sankyo Publishing (1982) "Drug Interaction and Mechanism": Masayasu Sugiyama, Nikkei BP (2016)

Japanese Unexamined Patent Publication No. 62-146584 Japanese Unexamined Patent Publication No. 2-3301 Japanese Unexamined Patent Publication No. 2004-324026 Japanese Unexamined Patent Publication No. 2006-291425

The present invention has been made to solve the problems of such conventional techniques, and an object of the present invention is that it is not affected by the bactericidal action from pulp, which is an organic substance, and has a bactericidal effect of a drug. It is an object of the present invention to provide a technique of a grape-like fine particle aggregate capable of reducing the influence on the human body as much as possible without lowering the amount of water, and a sanitary paper using the same.

The present invention made to achieve the above object includes nanometer-sized nuclear fine particles containing a quaternary ammonium salt and a water-resistant first coating layer provided so as to cover the surface of the nuclear fine particles. , A water resistant second coating layer provided to cover the surface of the first coating layer, and a cationized water resistant third coating layer provided to cover the surface of the second coating layer. It is a bactericidal nanocapsule having a coating layer of.
In the present invention, it is also effective when the quaternary ammonium salt is a chitosan quaternary ammonium salt.
In the present invention, the first coating layer is composed of a mixture containing 2-hydroxyethylurea, polyacrylic acid, and gelatin, and the second coating layer is a rack resin, polyvinyl alcohol, and polyacrylic. It is also effective when it is composed of a mixture containing an acid and the third coating layer is composed of a mixture of calcium carbonate and an alkyl ketene dimer.
Further, the present invention is a grape-like fine particle aggregate in which any of the above-mentioned bactericidal nanocapsules is attached to the surface of the polymer-based nanofiber aggregate.
The present invention is also effective when the constituent material of the polymer-based nanofiber aggregate is polypropylene nanofibers.
Further, the present invention has a vine-like fine particle aggregate having bactericidal nanocapsules attached to the surface of the polymer-based nanofiber, and the vine-like fine particle aggregate is blended into a paper made of wood fiber. The bactericidal nanocapsule has a nuclear fine particle containing a quaternary ammonium salt and a single coating layer provided so as to cover the nuclear fine particle, and the coating layer is a rack resin. A sanitary paper consisting of a mixture containing 2-hydroxyethylurea, polyacrylic acid, gelatin, calcium carbonate and alkylketen dimer.
Further, in the present invention, in a sealable container, the temperature inside the container is lowered to a temperature higher than 0 ° C., the pressure inside the container is reduced to a predetermined vacuum pressure, and the quaternary ammonium is rotated by rotating the container. The step of separating and dispersing the salt aqueous solution by stirring and suspending it as droplets in the container and continuing the rotation of the container to raise the temperature in the container from a temperature higher than 0 ° C to a temperature lower than 0 ° C. A step of lowering the pressure, maintaining the pressure in the container at the predetermined vacuum pressure, and irradiating the droplets of the quaternary ammonium salt aqueous solution with ultrasonic waves to vibrate the droplets to atomize the droplets. The step of producing nanometer-sized nuclear fine particles by freezing and solidifying the droplets by maintaining the temperature inside the container at a temperature lower than 0 ° C., and the water resistance that covers the surface of the nuclear fine particles. A step of sequentially providing a coating layer (1), a water-resistant second coating layer covering the first coating layer, and a cationically ionized water-resistant third coating layer covering the second coating layer. It is a method for producing a bactericidal nanocapsule having.
In the present invention, the first coating layer is composed of a mixture containing 2-hydroxyethylurea, polyacrylic acid, and gelatin, and the second coating layer is a rack resin, polyvinyl alcohol, and polyacrylic. It is also effective when it is composed of a mixture containing an acid and the third coating layer is composed of a mixture containing calcium carbonate and an alkyl ketene dimer.
Further, the present invention comprises a step of adhering a bactericidal nanocapsule obtained by any of the above methods to the surface of a polymer nanofiber whose surface has been anionized. It is a manufacturing method.
Further, in the present invention, the grape-like fine particle aggregate obtained by the above-mentioned method is dispersed in a slurry-like paper material, and the sanitary paper in a dry state is subjected to a predetermined papermaking process including a step of heating at 100 ° C. or higher. It is a manufacturing method of sanitary paper having a process of manufacturing.

Since the bactericidal nanocapsule of the present invention has a water-resistant coating layer, the quaternary ammonium salt does not come into contact with the wood fiber even when dispersed in the wood fiber, and the quaternary ammonium salt does not come into contact with the wood fiber. The high bactericidal action of the quaternary ammonium salt can be maintained.

In pharmacodynamics, a drug has a therapeutic effect and a side effect (see Non-Patent Document 7), and generally, when the therapeutic effect is large, the side effect is also considered to be large.

However, since the bactericidal nanocapsules of the present invention have a nanometer-sized size and a high bactericidal action, the amount of the bactericidal component to be blended is limited to the limit as compared with the prior art. It can be reduced, and as a result, while having the required therapeutic effect (bactericidal rate of 90% or more), the components of the drug harmful to the human body are at the level of ppm or less, and a product that does not have an adverse effect on the human body is supplied. Will be possible.

In this regard, quoting the elemental reduction principle, the bactericidal activity of a drug can be decomposed to the level of elementary particles (microsomes), and the bactericidal effect can be reduced to act on the cell wall of bacteria, and as a result, the drug. It becomes possible to suppress the blending amount of the above to the utmost limit.

Further, since the sanitary paper of the present invention has a property that the coating layer of the bactericidal nanocapsules is easily dissolved in water, the coating layer dissolves when the bactericidal nanocapsules come into contact with water during use. It breaks, the quaternary ammonium salt inside dissolves, and immediately attacks bacteria with anions, so sterilization can be performed extremely efficiently.

Further, since the sanitary paper of the present invention is a dry type, it can be reduced in weight, and since it has a water-resistant coating layer, it is not easily deteriorated in the atmosphere and can be used for a long period of time. Is.

Cross-sectional view schematically showing a configuration example of a bactericidal nanocapsule according to the present invention. A flow chart showing an example of a method for producing a sanitary paper using a bactericidal nanocapsule and a grape-like fine particle aggregate according to the present invention. (A): Front view showing the appearance of an example of the polymer nanofiber used in the present invention (b): Side view of the polymer nanofiber (c): Front view showing the appearance of the polymer nanofiber. (D): sectional view taken along line AA of FIG. 3 (c). Explanatory drawing which shows typically the grape-like fine grain aggregate which concerns on this invention. IR spectrum showing the analysis results of PP nanofibers after surface treatment Photograph showing the grape-like fine particle aggregate of this example An enlarged photograph of the sanitary paper of this example

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a cross-sectional view schematically showing a configuration example of a bactericidal nanocapsule according to the present invention.

As shown in FIG. 1, the bactericidal nanocapsule 1 of the present invention comprises a nuclear fine particle 2, a water-resistant first coating layer 11 provided so as to cover the surface of the nuclear fine particle 2, and a first coating layer. A water-resistant second coating layer 12 provided so as to cover the surface of the second coating layer 12, and a water-resistant third coating layer 13 provided so as to cover the surface of the second coating layer 12 and cationized. have.

Here, the nuclear fine particles 2 contain a quaternary ammonium salt (for example, a quaternary ammonium salt of chitosan), and are composed of nanometer-sized (about 100 nm) substantially spherical fine particles, that is, fine particles.

As used herein, the term "fine particles" refers to a composition consisting of at least two or more fine particles.
Further, the "fine particle" means a particulate matter of the smallest unit that maintains a bactericidal action, and is composed of at least two or more molecules.

The nuclear fine particles 2 in the present invention are fine particles composed of at least 60 fine particles.
The chitosan quaternary ammonium salt has a hydroxyl group as a functional group and has a good affinity with the surface-treated polypropylene nanofibers described later.

In the present invention, a quaternary ammonium salt or a carboxyl group having a hydroxyl group similar to that of a quaternary ammonium salt of chitosan, or a quaternary ammonium salt having both a hydroxyl group and a carboxyl group can be used.
The outer diameter of such nuclear fine particles 2 is 70 nm to 88 nm.

The first coating layer 11 is composed of a mixture containing 2-hydroxyethylurea, polyacrylic acid, and gelatin.
The thickness of the first coating layer 11 is 3 nm to 8 nm.

The second coating layer 12 is composed of a mixture containing a rack resin, polyvinyl alcohol, and polyacrylic acid.
The thickness of the second coating layer 12 is 4 nm to 10 nm.

The third coating layer 13 is composed of a mixture containing calcium carbonate and an alkyl ketene dimer.
The thickness of the third coating layer 13 is 5 nm to 12 nm.

[Manufacturing process of bactericidal nanocapsules]
FIG. 2 is a flow chart showing an example of a method for producing sanitary paper using the bactericidal nanocapsules and grape-like fine particle aggregates according to the present invention.
Hereinafter, an example of the method of the present invention will be described with reference to FIGS. 1 to 4.

<Preparation process of quaternary ammonium salt aqueous solution>
First, a quaternary ammonium salt aqueous solution is prepared (FIG. 2, process P1).

In this step, a quaternary ammonium salt of chitosan (2-hydroxypropyl trimethyl ammonium chloride chitosan) is used as the quaternary ammonium salt.

In the case of the present invention, the concentration of the chitosan quaternary ammonium salt aqueous solution is not particularly limited, but it is preferably set to 20 to 1000 ppm from the viewpoint of being based on the cosmetic drug addition index of each country.

<Process for making nuclear fine particles>
Next, nuclear fine particles 2 composed of chitosan quaternary ammonium salt are prepared (FIG. 2, process P2).
In the present embodiment, for example, the nuclear fine particles 2 are produced using the following processing apparatus.

This processing apparatus has a container capable of high-speed rotation (8,000 to 12,000 rpm) and can be sealed, and the chitosan quaternary ammonium salt aqueous solution is contained in the container.

The container is configured so that the air inside the container can be evacuated and the air inside the container can be introduced to adjust the pressure inside the container.

In addition, this processing device has a temperature control mechanism that controls the temperature inside the container to a predetermined temperature, and an ultrasonic oscillator that irradiates an aqueous solution of chitosan quaternary ammonium salt in the container with ultrasonic waves. ..

In order to prepare the nuclear fine particles 2 using the processing apparatus having such a configuration, first, a predetermined amount (for example, about 45 g) of a chitosan quaternary ammonium salt aqueous solution is put in the container, and the container is rotated and the container is rotated. Vacuum exhaust inside the container and introduce air into the container.

In this case, the pressure inside the container is gradually reduced by gradually increasing the rotation speed of the container, gradually increasing the amount of vacuum exhaust in the container, and gradually reducing the amount of air introduced into the container.

During this step, the temperature inside the container is controlled to be higher than 0 ° C. (for example, + 2 to + 5 ° C.).

By this step, the chitosan quaternary ammonium salt aqueous solution contained in the container is stirred, separated and dispersed, and floats as droplets in the container.

Then, when the vacuum pressure in the container reaches a predetermined value, the vacuum exhaust in the container and the introduction of air into the container are stopped.

After that, the rotation speed of the container is kept constant, for example, and the droplets of the chitosan quaternary ammonium salt aqueous solution in the container are irradiated with ultrasonic waves of constant intensity, for example.

During this step, the temperature inside the container is gradually lowered to a constant temperature lower than 0 ° C. (for example, -2 to -5 ° C).
The pressure inside the container is maintained at the above-mentioned vacuum pressure.

By this step, the particles of the chitosan quaternary ammonium salt aqueous solution in the container are gradually atomized by the vibration caused by the ultrasonic irradiation.

Then, when the diameter of the fine particles of the chitosan quaternary ammonium salt aqueous solution reaches a predetermined nanometer size (for example, 70 nm to 88 nm), the rotation speed of the container is gradually reduced, and the fine particles of the chitosan quaternary ammonium salt are gradually reduced. Gradually reduce the intensity of ultrasonic waves to the body.

On the other hand, during this step, the temperature inside the container is continuously controlled to be a constant temperature lower than 0 ° C. (for example, -2 to -5 ° C.). As a result, the fine particles of the quaternary ammonium salt of chitosan freeze and solidify.

Through the above steps, a large number of nanometer-sized nuclear fine particles 2 made of frozen chitosan quaternary ammonium salt can be obtained.

<Step of forming the first coating layer>
A water-resistant first coating layer 11 covering the surface of the nuclear fine particles 2 obtained in the above process P2 is formed (FIG. 2, process P3).

In this example, as the material of the first coating layer 11, 2-hydroxyethylurea (CAS: 2078-71-9), polyacrylic acid (CAS: 9003-01-4), and gelatin (CAS: 9000-) are used. Those consisting of a mixture containing 70-8) and are used.

In this step, a large number of nuclear fine particles 2 obtained in the above-mentioned nuclear fine particle preparation step P2 are placed in a predetermined vacuum flow tank and suspended in a vacuum at a temperature of −5 to −15 ° C. A mist-like liquid made of the material of the first coating layer 11 is sprayed onto the nuclear fine particles 2 from all sides using a sonic atomization nozzle.

Here, gelatin, which is a polymer substance, plays a role as a coagulant and a role of protecting the quaternary ammonium salt of chitosan when exposed to a high temperature (100 ° C. or higher) in the papermaking process described later. is there.
This step is carried out for about 5 to 15 minutes, depending on the amount of the nuclear fine particles 2.

<Step of forming the second coating layer>
A water-resistant second coating layer 12 that covers the surface of the first coating layer 11 of the nuclear fine particles 2 is formed (FIG. 2, process P4).

In this example, as the material of the second coating layer, rack resin (CAS: 9000-59-3), polyacrylic acid (CAS: 9003-01-4), and polyvinyl alcohol (CAS: 9002-89-5) ) And a mixture containing and.

In this step, a large number of nuclear fine particles 2 on which the first coating layer 11 is formed are placed in a predetermined vacuum flow tank, suspended in a vacuum at a temperature of −5 to −15 ° C., and a plurality of ultrafine particles 2 are formed. A mist-like liquid made of the material of the second coating layer 12 is sprayed onto the nuclear fine particles 2 from all sides using a sonic atomization nozzle.

Polyvinyl alcohol, which is a polymer substance, plays a role as a film-forming agent and, like the above-mentioned gelatin, plays a role of protecting chitosan quaternary ammonium salt when exposed to a high temperature (100 ° C. or higher) during the papermaking process. However, it evaporates due to the heat generated during this papermaking process.
This step is carried out for about 5 to 15 minutes, depending on the amount of the nuclear fine particles 2.

An easily volatile solvent such as ethylene glycol can be used instead of polyvinyl alcohol.

<Step of forming the third coating layer>
A cationized third coating layer 13 is formed over the surface of the second coating layer 12 of the nuclear fine particles 2 (process P5 in FIG. 2).

In this example, as the material of the third coating layer, a mixture (emulsified aqueous solution) containing calcium carbonate (CAS: 471-34-1) and an alkyl ketene dimer (CAS: 89489-41-31) is used. Use.

Then, a large number of nuclear fine particles 2 on which the second coating layer 12 was formed were placed in a predetermined vacuum flow tank, suspended in a vacuum at a temperature of −5 to −15 ° C., and provided in the tank. The atomized liquid of the material of the third coating layer 13 is sprayed on the nuclear fine particles 2 from all sides using an ultrasonic atomization nozzle.

Calcium carbonate used in this step has a function of cationizing fine particles, and as will be described later, a polymer-based nanocapsule is attached to the surface of an anionized polymer-based nanofiber aggregate. By ionically binding to nanofibers, it has the effect of improving the dispersion stability of the quaternary ammonium salt.
This step is carried out for about 5 to 15 minutes, depending on the amount of the nuclear fine particles 2.

[Manufacturing process of polymer nanofiber aggregate]
3 (a) to 3 (d) schematically show the polymer-based nanofibers used in the present invention, and FIGS. 3 (a) and 3 (c) show the appearance of the polymer-based nanofibers. The front view shown, FIG. 3 (b) is a side view of the polymer-based nanofiber, and FIG. 3 (d) is a sectional view taken along line AA of FIG. 1 (c).

The polymer-based nanofiber 3 used in the present invention is a nanofiber (a fibrous substance having a diameter of 1 nm to less than 1 μm) composed of a polymer material, and has openings at both ends (hereinafter, appropriately referred to as “ It is called "nanofiber").

Here, as the polymer material constituting the nanofiber 3, a material that can be produced in the form of fibers and is insoluble in water, fatty acid amide, hypochlorous acid, ethanol, isobutyltriethoxysilane, and ethyl acetate is used. Is preferable.

Examples of such a polymer material include those made of a thermoplastic resin such as PP (polypropylene), PET (polyethylene terephthalate), PE (polyethylene), and PU (polyurethane).

As the spinning method of nanofiber 3, a melt blow method that does not require a solvent, has high safety, and can be mass-produced at low cost is preferable.

In the case of the present invention, the material of the nanofiber 3 is not particularly limited, but it is made of polypropylene from the viewpoint of ease of manufacturing the fiber and obtaining softness when the aggregate is formed. Can be preferably used.

As shown in FIGS. 3A to 3D, the polymer-based nanofiber 3 used in the present invention has a hollow structure inside, that is, a hollow portion 4 formed along the longitudinal direction thereof. ing.

In this case, as the polymer-based nanofiber 3, those having an inner diameter of about 1/2 of the outer diameter can be preferably used.

Specifically, hollow nanofibers having an outer diameter of 20 to 1000 nm and an inner diameter of 10 to 500 nm are preferable, and more preferably, the outer diameter is 20 to 100 nm and the inner diameter is 10 to 50 nm.

In order to prepare a grape-like fine particle aggregate using this polymer-based nanofiber 3, first, as shown in process P6 of FIG. 2, a surface treatment (anionization treatment) step of the polymer-based nanofiber 3 is performed. ..

<Surface treatment process of polymer nanofibers>
In the present invention, for example, fatty acid amide and hypochlorous acid can be used as the surface treatment material for the nanofiber 3.

Here, the fatty acid amide is used for degreasing the surface portion of the nanofiber 3 (outer surface portion 3a and inner surface portion 3b: see FIGS. 3A to 3D).

In the case of the present invention, the type of fatty acid amide used for degreasing the surface of the nanofiber 3 is not particularly limited, but it is preferable to use coconut fatty acid diethanolamide.

Palm fatty acid diethanolamide is widely used as a nonionic surfactant in shampoos, facial cleansers and the like, and is preferable because it can be easily obtained.

Other fatty acid amides, surfactants, and the like can also be used as long as they have a degreasing effect.

On the other hand, hypochlorous acid reacts with the coconut fatty acid diethanolamide adhering to the surface of the polymer nanofiber 3 by the above degreasing treatment, and the carboxyl group and the hydroxyl group cover the surface of the nanofiber to be anionized. Therefore, the affinity with the cationically ionized bactericidal nanocapsules 1 can be improved.

In the present invention, the material to be subjected to this treatment is not particularly limited to hypochlorous acid, but from the viewpoint of being a material used for general purposes and being easily available, hypochlorous acid is used. It is preferable to use it.

When surface treatment of nanofiber 3 is performed using the above fatty acid amide and hypochlorous acid, for example, the following treatment is performed.

First, a predetermined amount of nanofibers 3 is dispersed in an aqueous solution of fatty acid amide, and boiled at a temperature of, for example, about 100 ° C. for 30 to 40 minutes.

After this boiling step, the nanofibers 3 are washed with water, dehydrated for, for example, several minutes (about 2000 rpm) using a centrifuge, and then dried at a temperature of about 60 ° C. for about 30 minutes.

A predetermined amount of the dried nanofibers 3 is dispersed in an aqueous hypochlorous acid solution (concentration: 8 g / L), and the nanofibers are stirred at a temperature of about 30 ° C. for about 1 hour while maintaining the pH at 5 to 5.5. Hypochlorous acid is reacted with the fatty acid amide adhering to the surface of No. 3.

Then, the nanofiber 3 after the reaction is completed is filtered at normal pressure, dehydrated for several minutes (about 2000 rpm) with a centrifuge, and then dried at a temperature of about 60 ° C. for about 30 minutes.

Further, the above-mentioned surface-treated nanofibers 3 are pulverized to a length of 2 to 5 mm (average 3 mm) using a fine pulverizer (FIG. 2, process P7).
As a result, for example, an aggregate of polymer nanofibers 3 made of PP is obtained.

[Manufacturing process of grape-like fine particle aggregate]
<Step of attaching bactericidal nanocapsules to the surface of polymer nanofibers>
Next, the bactericidal nanocapsules 1 obtained by the above-mentioned processes P1 to P5 are attached to the surface of the aggregate of the above-mentioned nanofibers 3 (FIG. 2, process P8).

The reason for performing this step is that if the bactericidal nanocapsules 1 are to be bonded to the wood fibers in the sanitary paper making process as they are, the bactericidal nanocapsules 1 will almost float in the processing chamber and will be bonded to the wood fibers. This is because it is difficult to do so, and by performing this step, the polymer-based nanofibers 3 to which the bactericidal nanocapsules 1 are attached can be stably dispersed in the wood fibers.

In this step, first, the negatively charged and anionized polymer nanofibers 3 are placed in the vacuum chamber, and then the above-mentioned bactericidal nanocapsules 1 are placed in the vacuum chamber.

The bactericidal nanocapsule 1 on which the third coating layer 13 containing calcium carbonate is formed is positively charged and cationized. The bactericidal nanocapsule 1 is placed in a vacuum chamber and is highly charged by electrostatic force. It is rapidly attached to the aggregate of molecular nanofibers 3.

By the above-mentioned steps, as shown in FIG. 4, a grape-like fine particle aggregate 10 in which a large number of bactericidal nanocapsules 1 containing a quaternary ammonium salt of chitosan are attached to the surface of the polymer-based nanofibers 3 is obtained. ..

As used herein, the term "grape-like" refers to a form in which a large number of particles are attached to a shaft, such as a fruit grape having a large number of fruits on the cob.

In the present invention, nanopulp fibers may be placed in a vacuum chamber instead of the polymer-based nanofibers 3 and bonded to the bactericidal nanocapsules 1.

[Making process of sanitary paper]
Using the grape-like fine particle aggregate 10, for example, a sanitary paper made of one sheet of paper is prepared by the following papermaking method (process P9 in FIG. 2).

In this example, first, a step of pulping various raw material woods is performed, and then the following adjustment steps are performed.

In the adjusting step, various pulps are mixed and beaten using a device called a refiner to disperse the above-mentioned grape-like fine particle aggregate 10 and add a predetermined chemical. The pulp that has undergone this adjustment step is in the form of a slurry and is called a paper material.

Further, the sanitary paper of the present invention can be obtained by going through a known papermaking process, coating process, finishing / processing process.

In the papermaking process described above, when the bactericidal nanocapsules 1 of the grape-like fine particle aggregate 10 are heated to 100 ° C. or higher, the following changes occur.

That is, among the materials constituting the second coating layer 12, polyvinyl alcohol and polyacrylic acid evaporate, and the remaining rack resin, 2-hydroxyethylurea and polyacrylic acid constituting the first coating layer 11 and The gelatin is mixed with calcium carbonate and the alkylketen dimer constituting the third coating layer 13 to form a single coating layer.
This coating layer has the property of dissolving and tearing immediately when it comes into contact with water.

Therefore, if the present invention is applied to a paper product such as tissue paper, a sanitary paper capable of attacking bacteria can be obtained by dissolving nuclear fine particles 2 made of chitosan quaternary ammonium salt immediately upon contact with water.

That is, when the sanitary paper of the present invention comes into contact with water, the coating layer of the bactericidal nanocapsule 1 existing on the surface or inside of the wood fiber dissolves and bursts, and the nuclear fine particles 2 composed of the quaternary ammonium salt of chitosan dissolve. put out.

At this time, the cation-bearing chitosan quaternary ammonium salt binds first to the anion-bearing bacteria (prior to the pulp anions), thereby exhibiting a bactericidal action against the bacteria.

As long as the number of cations of the chitosan quaternary ammonium salt does not exceed the number of bacterial anions, the chitosan quaternary ammonium salt will not bind to the pulp and be contaminated.

The present invention is not limited to the above embodiment, and various modifications can be made.
For example, in the above embodiment, a bactericidal component is used as a component of the bactericidal nanocapsule 1, but other analgesic components, deodorant components, fragrance components, antioxidant components, skin care components, etc. are used, and other than sanitary paper. It can also be used for applications.

The sanitary paper of the present invention is not particularly limited, but can be applied to thin paper products such as disposable paper towels and tissue paper.

In addition to sanitary paper, the bactericidal nanocapsules of the present invention include antibacterial processed plastic products, cloth products such as lab coats, rubber products such as surgical gloves, sanitary products such as masks, leather products, paints, synthetic wood, etc. It can be applied to various uses.

Hereinafter, the present invention will be illustrated in Examples, but it is not intended to limit the present invention.
Unless otherwise specified,% described below indicates% by weight.

[Creation of bactericidal nanocapsules]
First, a chitosan quaternary ammonium salt aqueous solution having a concentration of 1000 ppm was prepared.

45 g of this quaternary ammonium salt aqueous solution of chitosan was housed in the container of the above-mentioned processing apparatus to rotate the container at high speed, and vacuum exhaust in the container and air were introduced into the container.

In this case, the rotation speed of the container is gradually increased (8,000 to 12,000 rpm), the amount of vacuum exhaust in the container is gradually increased, and the amount of air introduced into the container is gradually reduced. The pressure was gradually reduced.
In addition, the temperature was controlled so that the temperature inside the container was +2 to + 5 ° C.

By this step, the chitosan quaternary ammonium salt aqueous solution contained in the container is stirred, separated and dispersed, and floats as droplets in the container.

Then, when the vacuum pressure in the container reached a predetermined value, the vacuum exhaust in the container and the introduction of air into the container were stopped.

Then, the rotation speed of the container was kept constant, and the droplets of the chitosan quaternary ammonium salt aqueous solution in the container were irradiated with ultrasonic waves of constant intensity.

During this step, the temperature inside the container was gradually lowered and controlled to be −2 to −5 ° C.
The pressure inside the container was maintained at the above-mentioned vacuum pressure.

By this step, the particles of the chitosan quaternary ammonium salt aqueous solution in the container were gradually atomized by the vibration caused by ultrasonic irradiation.

Then, when the diameter of the fine particles of the chitosan quaternary ammonium salt aqueous solution reaches a predetermined nanometer size (70 nm to 88 nm), the rotation speed of the container is gradually reduced, and the fine particles of the chitosan quaternary ammonium salt are gradually reduced. The intensity of the ultrasonic waves was gradually reduced.

During this step, the temperature inside the container was continuously controlled to be −2 to −5 ° C., and the fine particles of the quaternary ammonium salt of chitosan were frozen and solidified.

Through the above steps, a large number of nanometer-sized nuclear fine particles composed of a frozen chitosan quaternary ammonium salt were obtained.

Then, using a material composed of a mixture containing 2-hydroxyethylurea, polyacrylic acid, and gelatin, a water-resistant first coating layer was formed so as to cover the surface of the nuclear fine particles.

In this case, a large number of nuclear fine particles obtained in the above steps are placed in a predetermined vacuum flow tank, suspended in a vacuum at a temperature of −5 to −15 ° C., and a plurality of ultrasonic mist provided in the tank. A mist-like liquid made of the above-mentioned material was sprayed on the nuclear fine particles from all sides for about 5 to 15 minutes using a chemical nozzle.

Next, using a material composed of a mixture containing a rack resin, polyacrylic acid, and poly (vinyl alcohol), a second coating layer having water resistance is used so as to cover the surface of the first coating layer of the nuclear fine particles. Was formed.

In this case, a large number of nuclear fine particles on which the first coating layer is formed are placed in a predetermined vacuum flow tank, suspended in a vacuum at a temperature of −5 to −15 ° C., and provided in the tank. A mist-like liquid made of the above material was sprayed on the nuclear fine particles from all sides using an ultrasonic atomization nozzle.

Further, using a material composed of a mixture (emulsified aqueous solution) containing calcium carbonate and an alkyl ketene dimer, a cationized third coating layer was formed so as to cover the surface of the second coating layer of the nuclear fine particles. ..

In this case, a large number of nuclear fine particles on which the second coating layer is formed are placed in a predetermined vacuum flow tank, suspended in a vacuum at a temperature of −5 to −15 ° C., and provided in the tank. The atomized liquid of the material of the third coating layer was sprayed on the nuclear fine particles from all sides for about 5 to 15 minutes using an ultrasonic atomization nozzle.
Through the above steps, the bactericidal nanocapsules of this example were obtained.

[Surface treatment of PP nanofibers]
First, hollow nanofibers (manufactured by Kosuke Nanotechnology Co., Ltd.) made of PP having an outer diameter of 20 to 100 nm were prepared. This PP nanofiber has both ends open.

Then, 25 g of this PP nanofiber was dispersed in 1 L (liter) of a coconut fatty acid diethanolamide solution (1 g of Coconut Dietanol Amide RSAW 6501 manufactured by Amway, added to 1 L of water), and boiled at 100 ° C. for 30 to 40 minutes. ..

After boiling, the PP nanofibers were washed with water, dehydrated in a centrifuge for 3 minutes (2000 rpm), and then dried at 60 ° C. for 30 minutes.

After drying, 25 g of PP nanofibers was dispersed in 1 L of a hypochlorous acid aqueous solution (concentration: 8 g / L), and the mixture was stirred at 30 ° C. for 1 hour while maintaining the pH at 5 to 5.5.

After the reaction was completed, the PP nanofibers were filtered under normal pressure and dehydrated in a centrifuge for 3 minutes (2000 rpm). After dehydration, it was dried at 60 ° C. for 30 minutes.

The PP nanofibers after the surface treatment were analyzed using an infrared spectrometer (IR). The result is shown in FIG.

As shown in the IR spectrum of FIG. 5, peaks in the range of 3000 to 2500 and strong single peaks of 1770 to 1700 indicate the presence of a carboxyl group, which indicates that the PP nanos of this example are present. It was confirmed that the fiber was surface-treated.

Then, the PP nanofibers after the surface treatment described above were pulverized to a length of 2 to 5 mm (average 3 mm) using a fine pulverizer. As a result, PP nanofiber aggregates having a predetermined length were obtained.

[Creation of grape-like fine particle aggregate]
The above-mentioned bactericidal nanocapsules are placed in the above-mentioned vacuum electrostatic field device and mixed with a PP nanofiber aggregate having a diameter of 20 to 100 nm, a length of 2 to 5 mm (average 3 mm), and a total weight of 20 g to form a grape. A fine aggregate was obtained.

FIG. 6 is a photograph showing the obtained grape-like fine particle aggregates of this example.
As shown in FIG. 6, the grape-like fine particle aggregate of this example is solid and is obtained as a collection of fine components.

[Creation of sanitary paper containing grape-like fine particle aggregate]
The above-mentioned grape-like fine particle aggregate was added to the pulp slurry, and a plurality of sanitary papers (size: 210 mm × 190 mm) composed of one piece of tissue paper were prepared by the above-mentioned papermaking process.

FIG. 7 is an enlarged photograph showing the sanitary paper of this embodiment.
As shown in FIG. 7, in the sanitary paper containing the above grape-like fine particle aggregates, nanocapsules are dispersed in wood fibers.

When the sanitary paper of this example was measured using a Fourier transform infrared spectrophotometer (FTIR), the total weight of one paper was 0.55 g, and one sheet contained 0.01% of PP nanofibers. A sample of sanitary paper containing 0.000015% of the quaternary ammonium salt of chitosan contained in the above was obtained.

In addition, a sample of this sanitary paper was subjected to a sterilization test of Escherichia coli in a biochemical incubator in accordance with the Chinese sanitary standard QB / T2738-2012.

In this case, the sample was tested using three layers of sanitary paper. The results are shown in Table 1.

The above measurements and tests were carried out by CCIC Traceability CO., Ltd., a third-party analytical institution. Ltd. It is due to.

As shown in Table 1 below, the sample of the sanitary paper of the present invention has a sufficient bactericidal action by adding a very small amount (0.004%) of a quaternary ammonium salt to pulp which is a wood fiber. The result was obtained. When this sanitary paper is used, for example, three sheets are stacked and used as a set, so that an extremely high sterilizing effect (sterilization rate of 90% or more) can be exhibited.

As shown in Table 1, the effect of the present invention could be confirmed.
The sanitary paper of the present invention can be mass-produced by using, for example, the Best Former Yankee Paper Machine (BF-1000: high-speed model) manufactured by Kawanoe Zoki Co., Ltd.

Using this device, for example, sanitary paper having a paper width of 276 cm can be produced in a roll shape at a speed of 800-1000 m / min.

1 ... Sterilizing nanocapsules 2 ... Nuclear fine particles 3 ... Polymer-based nanofibers 3a ... Outer surface portion 3b ... Inner surface portion 4 ... Hollow portion 10 ... Grape-like fine particle aggregate 11 ... First coating Layer 12 ... Second coating layer 13 ... Third coating layer

Claims (10)

Nanometer-sized nuclear particles containing quaternary ammonium salts and
A water-resistant first coating layer provided so as to cover the surface of the nuclear fine particles, and
A water-resistant second coating layer provided so as to cover the surface of the first coating layer, and
A bactericidal nanocapsule having a water-resistant third coating layer provided so as to cover the surface of the second coating layer and cationized. The bactericidal nanocapsule according to claim 1, wherein the quaternary ammonium salt is a chitosan quaternary ammonium salt. The first coating layer comprises a mixture containing 2-hydroxyethylurea, polyacrylic acid, and gelatin, and the second coating layer contains a rack resin, polyvinyl alcohol, and polyacrylic acid. The bactericidal nanocapsule according to any one of claims 1 or 2, wherein the third coating layer comprises a mixture of calcium carbonate and an alkylketen dimer. A grape-like fine particle aggregate in which the bactericidal nanocapsule according to any one of claims 1 to 3 is attached to the surface of the polymer-based nanofiber aggregate. The grape-like fine particle aggregate according to claim 4, wherein the constituent material of the polymer-based nanofiber aggregate is polypropylene nanofiber. A sanitary paper having a grape-like fine particle aggregate having bactericidal nanocapsules attached to the surface of the polymer-based nanofiber, and the grape-like fine particle aggregate being blended into a paper made of wood fiber.
The bactericidal nanocapsule has a nuclear fine particle containing a quaternary ammonium salt and a single coating layer provided so as to cover the nuclear fine particle.
A sanitary paper in which the coating layer is a mixture containing a rack resin, 2-hydroxyethylurea, polyacrylic acid, gelatin, calcium carbonate and an alkyl ketene dimer. In a container that can be closed, the temperature inside the container is lowered to a temperature higher than 0 ° C., and the pressure inside the container is reduced to a predetermined vacuum pressure, and the quaternary ammonium salt aqueous solution is stirred by rotating the container. The process of separating and dispersing by means of floating in the container as droplets,
The rotation of the container is continued, the temperature inside the container is lowered from a temperature higher than 0 ° C. to a temperature lower than 0 ° C., and the pressure inside the container is maintained at the predetermined vacuum pressure, and the quaternary ammonium is used. The process of atomizing the droplets of the salt solution by irradiating the droplets with ultrasonic waves and vibrating them.
By maintaining the temperature inside the container at a temperature lower than 0 ° C., the droplets are frozen and solidified to produce nanometer-sized nuclear fine particles.
A water-resistant first coating layer covering the surface of the nuclear fine particles, a water-resistant second coating layer covering the first coating layer, and a cationic water-resistant coating layer covering the second coating layer. A method for producing a bactericidal nanocapsule, which comprises a step of sequentially providing a third coating layer. The first coating layer comprises a mixture containing 2-hydroxyethylurea, polyacrylic acid, and gelatin, and the second coating layer contains a rack resin, polyvinyl alcohol, and polyacrylic acid. The method for producing a bactericidal nanocapsule according to claim 7, wherein the third coating layer comprises a mixture, and the third coating layer comprises a mixture containing calcium carbonate and alkylketen dimer. A grape-like fine particle aggregate having a step of adhering a bactericidal nanocapsule obtained by the method according to any one of claims 7 or 8 to the surface of a polymer-based nanofiber whose surface has been anionized. Manufacturing method. The grape-like fine particle aggregate obtained by the method according to claim 9 is dispersed in a slurry-like paper material, and a dry sanitary paper is produced through a predetermined papermaking process including a step of heating at 100 ° C. or higher. A method for manufacturing sanitary paper having a process.

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