JP2005336363A - Antibacterial moisture-permeable sheet - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prepare a moisture-permeable sheet having sufficient antibacterial properties, which is produced by homogeneous mixing of even a small mixing amount of an antibacterial agent into a resin. <P>SOLUTION: The antibacterial moisture-permeable sheet of the present invention is obtained by melting and kneading antibacterial agent particles each having numerous thin and long projections with a thermoplastic resin so as to crush the particles, melting the resultant product, forming a film, and then extending the film. An apparent particle diameter of the antibacterial agent particle before melting and kneading is preferably between 5 and 100 μm. The antibacterial agent particles are preferably in the shape of sea urchin or tetrapod. The antibacterial agent particles are preferably made of a cancrinite-like mineral containing metals having antibacterial properties. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a moisture-permeable sheet having antibacterial properties.

  A moisture-permeable sheet made of a porous film and having an antibacterial agent is known. For example, after melt-forming a resin composition containing 100 parts by weight of a thermoplastic resin, 100 to 400 parts by weight of an inorganic filler and 0.05 to 5 parts by weight of an antibacterial agent, the film is stretched at least 1.5 to 7 times in a uniaxial direction. An antibacterial porous film obtained in this way has been proposed (see Patent Document 1). In addition, an antibacterial having a porosity of 50% or more obtained by stretching a film or sheet of a resin composition containing 100 parts by weight of a polyolefin resin, 0.2 to 5 parts by weight of an antibacterial agent, and 5 to 20 parts by weight of a filler. A porous film has been proposed (see Patent Document 2).

  In these antibacterial porous films, the antibacterial agent is exposed on the surface by forming a large number of micropores in the film, thereby achieving sufficient antibacterial properties even when the amount of the antibacterial agent used is small. However, when the particle size of the antibacterial agent is small or the blending amount of the antibacterial agent is small, it is not easy to uniformly mix with the resin. As a result, it is not easy to expose the antibacterial agent to a uniform surface, and sufficient antibacterial properties are difficult to develop. If the particle size of the antibacterial agent is increased, it can be easily mixed with the resin, but on the other hand, perforation is likely to occur in the sheet.

JP-A-6-49253 JP-A-9-48868

  Accordingly, an object of the present invention is to provide an antibacterial moisture-permeable sheet that can eliminate the various disadvantages of the above-described prior art.

  The present invention provides an antibacterial moisture-permeable sheet obtained by melt-kneading an antibacterial agent particle having a large number of elongated protrusions with a thermoplastic resin, pulverizing the particle, then melt-forming and then stretching the particle. The above-mentioned purpose is achieved.

  The present invention also includes a mixture of particles having a number of elongated protrusions and a thermoplastic resin, the mixture amount of which is 0.05 to 5 parts by weight with respect to 100 parts by weight of the thermoplastic resin. The present invention provides a method for producing a sheet-like molded product in which the particles are pulverized by kneading and then the melt-kneaded product is melt-formed.

  In the antibacterial moisture-permeable sheet of the present invention, since the apparent particle diameter of the antibacterial agent used as a raw material is large, the antibacterial agent is easily mixed with the resin uniformly. Since this antibacterial agent is pulverized in the melt-kneading process and its particle size is reduced, it is difficult for the sheet to be perforated. As a result, even if the blending amount of the antibacterial agent is small, it is uniformly mixed with the resin, and a moisture permeable sheet having sufficient antibacterial properties can be obtained. Moreover, since it is hard to produce a hole in a sheet | seat, a moldability is favorable.

  Hereinafter, the present invention will be described based on preferred embodiments thereof. The antibacterial moisture-permeable sheet of the present invention is obtained by melt-kneading antibacterial agent particles having a large number of elongated protrusions with a thermoplastic resin to pulverize the particles, and then melt-forming and then stretching the particles. . The antibacterial moisture-permeable sheet of the present invention contains antibacterial agent particles and a thermoplastic resin as essential components, and further contains a filler used to make the sheet porous.

  There is no restriction | limiting in particular as a thermoplastic resin, The thing similar to what was conventionally used for this kind of sheet | seat can be used. A typical example of such a thermoplastic resin is a polyolefin-based resin. As the polyolefin resin, an α-olefin homopolymer, a copolymer composed of two or more α-olefins, a copolymer of an α-olefin and a monomer copolymerizable with the α-olefin, or Examples thereof include a mixture of these homopolymers and copolymers. Examples of the α-olefin include ethylene, propylene, butene, 4-methyl-1-pentene and the like. Moreover, as a monomer copolymerizable with an alpha olefin, vinyl acetate, acrylic acid, methacrylic acid etc. are mentioned, for example. This polyolefin resin has an α-olefin content of 70 mol% or more. Specific examples of these polyolefin resins include polyethylene, polypropylene, polybutene, poly-4-methyl-1-pentene, and random or block copolymers containing these as main components, ethylene-vinyl acetate copolymers, ethylene-acrylic. Examples include acid copolymers and ethylene-methacrylic acid copolymers.

  The thermoplastic resin used in the present invention has a melt flow rate of 0.01 to 15 g / 10 min in that the moldability in the production process of the antibacterial moisture-permeable film and the molding properties such as high strength and tear strength are good. In particular, 0.1 to 8 g / 10 min is preferable.

  As the filler used to make the sheet porous, the same fillers as those conventionally used for this type of moisture-permeable sheet can be used. The filler may be either an inorganic filler or an organic filler, or a combination of both. Examples of inorganic fillers include alkaline earth metals, Group III element oxides, hydroxides, carbonates, sulfates, silicates, and the like. Examples of the organic filler include cellulose powder such as wood powder and pulp, and cross-linked powder such as silicone and phenol. These can be used alone or in combination of two or more. Among these, it is preferable to use calcium carbonate or barium sulfate from the viewpoint of production cost and quality stability.

  The particle diameter of the filler is preferably about 0.1 to 8 μm, particularly about 0.5 to 5 μm from the viewpoint of improving stretchability while preventing particle aggregation.

  Thus, the type of antibacterial agent particles used in the present invention is not particularly limited as long as it has long and narrow protrusions that can be destroyed in the melt-kneading process with a thermoplastic resin. It is preferable that the antibacterial agent particles have an apparent particle diameter of 5 to 100 μm, particularly 8 to 50 μm from the viewpoint that the mixing with the thermoplastic resin can be performed uniformly. The apparent particle diameter of the antibacterial agent particles can be measured at a relative refractive index of 1.16 using, for example, a laser diffraction / scattering particle size distribution analyzer (LA-920 manufactured by Horiba, Ltd.).

  As the antibacterial agent particles having projections that are long enough to break the projections in the melt-kneading process with the thermoplastic resin, for example, antibacterial particles having a sea urchin shape or a tetrapod shape are preferably used (see Examples described later). . As the antibacterial agent particles having such a shape, a cancrinite-like mineral containing a metal having antibacterial properties is preferably used. Details of such a cancrinite-like mineral will be described later.

  In the antibacterial moisture-permeable sheet of the present invention, the antibacterial agent particles are preferably used in a small amount of 0.05 to 5 parts by weight, more preferably 0.1 to 3 parts by weight with respect to 100 parts by weight of the thermoplastic resin. Even if the blending amount of the antibacterial agent particles is so small, the antibacterial agent particles are uniformly dispersed in the sheet, so that a sufficient antibacterial effect is exhibited.

  On the other hand, there is no restriction | limiting in particular in the compounding quantity of the antimicrobial moisture-permeable sheet of this invention, It can be made to be the same as that of the filler currently mix | blended with the conventional moisture-permeable sheet. The blending amount of the filler can be appropriately increased or decreased according to the target moisture permeability. Generally, 70 to 400 parts by weight, particularly 100 to 400 parts by weight, especially 100 to 300 parts by weight of a filler is blended with 100 parts by weight of a thermoplastic resin to obtain a moisture permeable sheet having satisfactory moisture permeability. be able to.

  In addition to the various components described above, the antibacterial moisture-permeable sheet of the present invention is blended with various additives such as stabilizers, antioxidants, colorants, ultraviolet absorbers, lubricants and the like within a range that does not interfere with the effects of the present invention. be able to.

The antibacterial moisture-permeable sheet of the present invention has a Gurley air permeability (JIS P 8117) of 100 to 5000 seconds, particularly 200 to 3000 seconds. For example, the moisture-permeable sheet is used as a back sheet of an absorbent article. In the case, it is preferable from the point that the stuffiness during wearing of the absorbent article is effectively prevented. For the same reason, 40 ° C., the moisture permeability 90% (JIS P 0208) is 2000~11000g / m ² · day, it is particularly preferably 4000~10000g / m ² · day.

  As the thickness of the antibacterial moisture-permeable sheet of the present invention, an appropriate value is selected according to the specific application. In general, the thickness is preferably 5 to 100 μm, more preferably 10 to 100 μm, and particularly preferably 15 to 50 μm. In relation to the apparent particle diameter of the antibacterial agent particles described above, if an attempt is made to produce a sheet having a thickness in such a range, the antibacterial agent particles are too large and perforation is likely to occur when the unstretched film is stretched. However, since the antibacterial agent particles are pulverized by melt-kneading to reduce the particle size, there is no concern about the occurrence of pores during stretching.

  The antibacterial moisture-permeable sheet of the present invention is preferably used as a back sheet for absorbent articles as described above, and is preferably used as medical clothing, clothing sheets, clothing covers, and the like.

  Next, the preferable manufacturing method of the antimicrobial moisture-permeable sheet | seat of this invention is demonstrated. In addition, although this manufacturing method is especially preferable as a manufacturing method of the antimicrobial moisture-permeable sheet | seat of this invention, it is preferable also as a manufacturing method of other sheet-like molded products.

  First, a resin mixture is prepared. The resin mixture includes the antibacterial agent particles, the thermoplastic resin, and the filler, and further includes various additives as necessary. The blending amount of the antibacterial agent particles in this resin mixture is preferably 0.05 to 5 parts by weight, particularly 0.1 to 3 parts by weight with respect to 100 parts by weight of the thermoplastic resin. The blending amount of the filler is preferably 70 to 400 parts by weight, more preferably 100 to 400 parts by weight, and particularly preferably 100 to 300 parts by weight with respect to 100 parts by weight of the thermoplastic resin. For the preparation of the resin mixture, various types of mixers known in the art, for example, a Henschel mixer, a tumbler mixer, a super mixer, a V mixer, and the like can be used.

  In the manufacture of conventional moisture-permeable sheets containing antibacterial agents, in order to achieve uniform mixing of the antibacterial agents, a masterbatch of the antibacterial agent and thermoplastic resin is manufactured in advance, and the masterbatch is melted with other components. It was necessary to knead. On the other hand, according to the present production method, since the apparent particle size (particle size before melt kneading) of the antibacterial agent particles is large, the resin mixture can be directly supplied to the molding machine without producing a master batch. However, there is an advantage that the antibacterial agent particles and the thermoplastic resin are uniformly mixed.

  By melt-kneading the resin mixture in a molding machine, an external force is applied to the antibacterial agent particles, and the protrusions are destroyed. As a result, the antibacterial agent particles have a smaller particle size. As a result, the antibacterial particles having a small particle diameter are uniformly dispersed in the thermoplastic resin. Reducing the particle size is advantageous because the surface area of the antibacterial agent particles increases and the antibacterial activity increases. The temperature of melt kneading is generally 200 to 280 ° C. when a polyolefin resin is used, although it depends on the type of thermoplastic resin.

  The melt-kneaded product thus obtained is melt-formed to obtain an unstretched film. For melt film formation, known film formation methods such as an inflation molding method, a T-die molding method, and a calendar molding method can be used.

  Next, the unstretched film is uniaxially or biaxially stretched to form a large number of micropores, thereby obtaining a target antibacterial moisture-permeable sheet. At this time, since the antibacterial agent particles are pulverized and the particle diameter is reduced, generation of pores due to stretching is prevented. As a result, a moisture-permeable sheet can be obtained with good moldability. A roll method or a tenter method can be used for stretching. In the case of uniaxial stretching, roll stretching is usually used. In this case, the stretching may be performed in a single stage or multiple stages including two or more stages. The stretching temperature is adjusted in the range of room temperature to the melting point of the resin. The draw ratio is preferably 1.2 to 8 times, particularly 2 to 6 times, from the viewpoint of obtaining a sheet having sufficient moisture permeability, low rigidity, and good texture. In the case of biaxial stretching, simultaneous or sequential stretching is performed. The stretching temperature and the stretching ratio can be the same as in the case of uniaxial stretching. After stretching, if necessary, the sheet may be subjected to a heat setting treatment for the purpose of stabilizing the form of the micropores.

  In the above manufacturing method, particles other than antibacterial agent particles can be used as long as they have a large number of elongated protrusions. Therefore, this manufacturing method can be applied to the manufacturing method of sheet-like molded articles other than an antimicrobial moisture-permeable sheet by changing the kind of particle | grains to be used.

  Next, a cancrinite-like mineral containing a metal having antibacterial properties described above (hereinafter referred to as a metal-substituted cancrinite-like mineral) will be described. The metal-substituted cancrinite-like mineral is obtained by replacing the metal element in the cancrinite-like mineral with a metal element having antibacterial properties. A cancrinite-like mineral has a structure similar to an aluminosilicate compound. In the present invention, the cancrinite-like mineral is JCPDS (Joint Committee on Powder Diffraction Standards) No. 20-379, 20-743, 25-776, 25-1499, 25-1500, 30-1170, 31-1272, 34-176, 35-479, 35-653, 38-513, 38-514, 38- One having at least one X-ray diffraction pattern selected from the group consisting of 515 and 45-1373. In the X-ray diffraction pattern, one having a main peak at d = 0.365 ± 0.015 nm is preferable.

As the metal-substituted cancrinite-like mineral, it is preferable to use one represented by the following composition formula (1).
_{sM (1) x O y ·} tM (2) 2 O · Al 2 O 3 · uSiO 2 · vR m Q n · wH 2 O (1)
In the formula, M (1) represents a metal having antibacterial properties, M (2) represents one or more elements selected from the group consisting of Na, K and H, and R represents Na, K, Ca and Mg. Q represents one or more elements selected from the group, Q represents one or more atomic groups selected from the group consisting of CO ₃ , SO ₄ , NO ₃ , OH and Cl, and s represents 0 <s ≦ 3, t is 0 ≦ t ≦ 3 (where s + t = 0.5 to 3), u is 0.5 ≦ u ≦ 6, v is 0 <v ≦ 2, w is w ≧ 0, x is 1 ≦ x ≦ 2, y satisfies 1 ≦ y ≦ 3, m satisfies 1 ≦ m ≦ 2, and n satisfies 1 ≦ n ≦ 3.

In the formula (1), M (1) is preferably Ag, Zn or Cu, and particularly preferably Ag. M (1) may be one type or a combination of two or more types. When M (1) is a combination of two or more, the term of sM (1) _x O _y is described separately for each term corresponding to each element. For example, when M (1) is composed of metal elements D and D ′, sM (1) _x O _y is represented by s ₁ D _x1 O _y1 · s ₂ D ′ _x2 O _y2 (where x1 + x2 = x, y1 + y2 = y, s ₁ + s ₂ = s). The same applies to the other terms.

M (2) is preferably Na and / or H from the viewpoint of high antibacterial activity and economical efficiency. From the same viewpoint as M (2), R is preferably one or more metal elements selected from the group consisting of Na, Ca and Mg, and more preferably Na. Q is preferably CO ₃ and / or NO ₃ from the viewpoint of ease of particle shape control.

  s is preferably 0 <s ≦ 2, more preferably 0 <s ≦ 1, from the viewpoint of high antibacterial activity and economic efficiency. t is preferably 0 ≦ t ≦ 2, more preferably 0 ≦ t ≦ 1, from the viewpoint of maintaining a good pH of an aqueous dispersion of a metal-substituted cancrinite-like mineral (a 1 wt% aqueous dispersion described later). . s + t is preferably 0.5 to 1.8, more preferably 0.6 to 1.5. u is preferably 0.5 ≦ u ≦ 5, more preferably 0.5 ≦ u ≦ 4, from the viewpoint of high antibacterial activity. From the viewpoint of ease of particle shape control, v is preferably 0 <v ≦ 1.5, more preferably 0 <v ≦ 1. w is the content (molar ratio) of water contained in the metal-substituted cancrinite-like mineral, and varies depending on the form of the metal-substituted cancrinite-like mineral, for example, in the form of powder or slurry. x and y and m and n are arbitrarily determined according to the combination of M (1) and O and according to the combination of R and Q, respectively.

It metal-substituted cancrinite-like mineral that specific surface area is preferably less than 1 m ² / g or more 70m ² / g, more preferably from 1~65m ² / g, a 30~65m ² / g Is more preferable. If the specific surface area is within this range, a metal having antibacterial properties can be appropriately fixed or supported, and excellent antibacterial ability can be exhibited. The specific surface area of the metal-substituted cancrinite-like mineral can be adjusted to a predetermined range by appropriately acid-treating raw material aluminosilicate particles (aluminosilicate particles used as a raw material), for example, as described later. The specific surface area is measured using a flowsorb 2300 type (manufactured by Shimadzu Corporation). The sample is 0.1 g, and a mixed gas of N ₂ / He = 30/70 (volume ratio) is used as the adsorption gas.

  The metal-substituted cancrinite-like mineral preferably has a 1% by weight aqueous dispersion having a pH of 7 or higher, more preferably 8 or higher, and even more preferably 9 or higher, from the viewpoint of enhancing its antibacterial activity. preferable. The pH of a 1 wt% aqueous dispersion of metal-substituted cancrinite-like mineral is defined as the pH of the slurry after adding 1 g of sample to 99 g of ion-exchanged water (25 ° C.) and stirring for 2 minutes.

  In metal-substituted cancrinite-like minerals, antibacterial activity is manifested by the M (1) component. Therefore, from the viewpoint of developing excellent antibacterial activity, it is preferable that a large amount of M (1) component is present in the vicinity of the surface of the metal-substituted cancrinite-like mineral. The surface concentration of the M (1) component is determined by the molar ratio of the M (1) component atom to the Si atom [M (1) / Si] or the molar ratio of the M (1) component atom to the Al atom measured by ESCA [ M (1) / Al]. M (1) / Si is preferably 0.021 or more, more preferably 0.040 or more. Further, M (1) / Al is preferably 0.025 or more, more preferably 0.040 or more. The measurement by ESCA can be performed using ESCA-1000 manufactured by Shimadzu Corporation after forming a sample into a thin piece by a press. The element on the sample surface is measured [M (1) component atom, Si, Al], and the surface atom concentration ratio (molar ratio) is determined from the peak area of the obtained element.

Metal-substituted cancrinite-like mineral, for example, the composition of the anhydride, aM during _{2 O · Al 2 O 3 ·} bSiO 2 · cR m Q n ( wherein, M represents Na and / or K, R is Na, Q represents one or more elements selected from the group consisting of K, Ca and Mg, Q represents one or more atomic groups selected from the group consisting of CO ₃ , SO ₄ , NO ₃ , OH and Cl, and a represents A raw material aluminosilicate in which 0.5 ≦ a ≦ 3, b is 0.5 ≦ b ≦ 6, c is 0 <c ≦ 2, m is 1 ≦ m ≦ 2, and n is 1 ≦ n ≦ 3) In addition, it is obtained by subjecting to acid treatment using 0 to 300 meq (0 to 300 meq / 100 g) of acid per 100 g of the raw material aluminosilicate and ion exchange with antibacterial ions. preferable.

In the above formula, M is preferably Na. When M consists of Na and K, aM ₂ O is represented by a′Na ₂ O · a ″ K ₂ O (where a ′ + a ″ = a). The same applies to the other terms. R is preferably one or more elements selected from the group consisting of Na, Ca and Mg, and more preferably Na. Q is preferably CO ₃ and / or NO ₃ . a is preferably 0.5 ≦ a ≦ 2.5, more preferably 0.5 ≦ a ≦ 2. b is preferably 0.5 ≦ b ≦ 5, more preferably 0.5 ≦ b ≦ 4. c is preferably 0 <C ≦ 1.5, more preferably 0 <c ≦ 1. m and n are arbitrarily determined according to the combination of R and Q.

  The specific surface area of the raw material aluminosilicate is preferably about the same as that of the metal-substituted cancrinite-like mineral. The average particle diameter is also preferably about the same as that of the metal-substituted cancrinite-like mineral. Further, the form is not particularly limited, but for example, the same form as the metal-substituted cancrinite-like mineral is preferable.

There is no particular limitation on the method for producing the raw material aluminosilicate. For example, a method in which an alumina raw material and a silica raw material are reacted in an alkaline solution in the presence of CO ₃ ²⁻ , SO ₄ ²⁻ , NO ₃ ⁻ , Cl ^{− and the} like can be mentioned. Examples of the alumina raw material include aluminum oxide, aluminum hydroxide, and sodium aluminate. Sodium aluminate is particularly preferable. Examples of the silica raw material include silica sand, silica stone, water glass, sodium silicate, silica sol and the like. Water glass is particularly preferable. Alternatively, as a raw material for both the alumina raw material and the silica raw material, for example, clay minerals such as kaolin, montmorillonite, bentonite, mica and talc, and aluminosilicate minerals such as mullite may be used. Examples of the raw material for CO ₃ ^2- include carbon dioxide, sodium carbonate, potassium carbonate, potassium sodium carbonate, calcium carbonate, and magnesium carbonate. Sodium carbonate is particularly preferred. Examples of the raw material of SO ₄ ^2- include sulfuric acid, sodium sulfate, potassium sulfate, and potassium sodium sulfate. In particular, sulfuric acid and sodium sulfate are suitable. NO ₃ ^- as a raw material, such as nitric acid, sodium nitrate, potassium nitrate, and the like. Nitric acid and sodium nitrate are particularly suitable. Cl ^- The raw materials, for example, hydrochloric acid, sodium chloride, potassium chloride and the like. In particular, hydrochloric acid and sodium chloride are suitable. Examples of the alkali of the alkaline solution include oxides such as sodium oxide and potassium oxide; hydroxides such as sodium hydroxide and potassium hydroxide; carbonates such as sodium carbonate, potassium carbonate and potassium carbonate; sodium hydrogen carbonate and carbonate Hydrogen carbonate such as potassium hydrogen can be used. Oxides such as calcium oxide and magnesium oxide; hydroxides such as calcium hydroxide and magnesium hydroxide; carbonates such as calcium carbonate, magnesium carbonate and dolomite; bicarbonates such as calcium bicarbonate and magnesium bicarbonate Etc. may be used.

The raw material aluminosilicate can be obtained by mixing and reacting the above-mentioned various compounds in a predetermined ratio. About the ratio of a mixing | blending, it determines suitably according to the composition of the desired raw material aluminosilicate obtained. Preferably, the charge ratio of the component that is the raw material of the raw material aluminosilicate is expressed as M ₂ O, Al ₂ O ₃ , SiO ₂ , R _m Q _n based on the constituent elements of each component, As a molar ratio, M ₂ O / SiO ₂ is preferably 0.01 to 100, more preferably 0.05 to 80, and Al ₂ O ₃ / SiO ₂ is preferably 0.01 to 10, more preferably 0. 0.05 to 8, R _m Q _n / SiO ₂ is preferably 0.01 to 100, more preferably 0.05 to 80, and H ₂ O / M ₂ O is preferably 0.01 to 100, More preferably, it is 0.05-80.

  The reaction temperature at the time of producing the raw material aluminosilicate is preferably 15 to 300 ° C. from the viewpoint of increasing the crystallinity of the raw material aluminosilicate, stabilizing the form, and reducing the chemical and pressure load on the reaction vessel. More preferably, it is 60-150 degreeC, More preferably, it is 80-130 degreeC. The reaction time is preferably 2 hours or more and 48 hours or less from the viewpoint of complete crystallization reaction. As described above, the raw material aluminosilicate is usually obtained as an aqueous dispersion (slurry). The solid content concentration of the aqueous dispersion is preferably 0.1 to 50% by weight.

Subsequently, the obtained raw material aluminosilicate is acid-treated using 0 to 300 meq (0 to 300 meq / 100 g) of acid per 100 g of the raw material aluminosilicate. The acid treatment is performed to adjust the pH of the slurry when the M (1) component is fixed or supported on the raw material aluminosilicate by ion exchange. In that case, it is preferable to adjust pH of a slurry to 7 or less from a viewpoint of the expression of the ion exchange property of M (1) component. The acid treatment is also performed for adjusting the specific surface area. The acid treatment amount is preferably 6 to 300 meq / 100 g, more preferably 5 to 250 meq / 100 g, and still more preferably 20 to 140 meq / 100 g from the viewpoint of improving antibacterial activity. In addition, the case where acid treatment is performed using 0 meq / 100 g of acid means the case where acid treatment is not performed. For example, when the raw material aminosilicate has a specific surface area of 1 m ² / g or more and less than 70 m ² / g, the raw material aminosilicate may not be subjected to acid treatment. For the acid treatment, it is preferable to use a strong acid such as hydrochloric acid, sulfuric acid, or nitric acid, and it is particularly preferable to use hydrochloric acid or nitric acid. The acid treatment is performed by adding the aqueous solution containing the acid to the raw material aluminosilicate gradually or all at once and bringing the acid into contact with the raw material aluminosilicate. The addition rate is preferably 0.01 to 100 ml / min, more preferably 0.1 to 10 ml / min with respect to 100 g of the raw material aluminosilicate. In the acid treatment, the raw material aluminosilicate is preferably made into a slurry. The solid content concentration of the slurry is preferably 1 to 50% by weight from the viewpoint of ensuring the fluidity of the reaction mixture and preventing the unevenness of the acid treatment to improve the treatment efficiency. The temperature during the acid treatment is preferably 60 to 150 ° C., more preferably 80 to 120 ° C., from the viewpoint of improving the specific surface area and reducing the chemical and pressure load on the reaction vessel. The acid treatment may be performed with appropriate stirring. The acid treatment time is preferably 0.01 to 100 hours, more preferably 0.1 to 10 hours after the acid and the raw material aluminosilicate are brought into contact with each other. After the acid treatment, it is preferable that the reaction mixture is appropriately aged at, for example, 60 to 150 ° C. for about 0.1 to 10 hours.

  The raw material aluminosilicate after the acid treatment is ion-exchanged with metal ions having antibacterial properties. Alternatively, raw material aluminosilicate having a desired specific surface area may be ion-exchanged as it is without acid treatment. In the ion exchange, for example, the raw material aluminosilicate after acid treatment is suspended in water, and a compound containing the metal (hereinafter referred to as a metal-containing compound) or an aqueous solution of the compound is added thereto, or in an aqueous solution of the metal-containing compound. It can be carried out by immersing the raw material aluminosilicate in As described above, the raw material aluminosilicate does not have to be ion-exchanged after acid treatment. For example, if a metal-containing compound coexists during acid treatment, the raw material aluminosilicate is subjected to acid treatment and ion exchange at the same time. It can be carried out. The metal-containing compound is not particularly limited as long as it is a water-soluble metal-containing compound containing a desired metal, and for example, a nitrate, sulfate, chloride or the like containing a desired metal can be used. The ion exchange is usually performed with the raw material aluminosilicate suspended in water and stirring. From the viewpoint of improving the efficiency of ion exchange, the solid content concentration of the aqueous suspension of the raw material aluminosilicate is preferably 1 to 50% by weight. The temperature at the time of performing ion exchange is not particularly limited. Preferably it is 20-120 degreeC, More preferably, it is 80-110 degreeC. The ion exchange time is preferably 0.01 to 2 hours, more preferably 0.02 to 1 hour, after the raw material aluminosilicate and the metal-containing compound are brought into contact with each other. The amount ratio of the raw material aluminosilicate to the metal-containing compound in the ion exchange is preferably 0.1 to 30 parts by weight, more preferably 0.2 to 10 parts by weight, with respect to 100 parts by weight of the raw material aluminosilicate. More preferably, it is 0.5 to 5 parts by weight. After the ion exchange, it is preferable that the reaction mixture is appropriately aged, for example, at 60 to 150 ° C. for about 0.1 to 10 hours.

  Most preferably, the metal component in the metal-containing compound is fixed or supported on the cancrinite-like mineral by ion exchange as described above. However, instead of or in addition to ion exchange, the metal component in the metal-containing compound may be fixed or supported on the cancrinite-like mineral by an impregnation method or a precipitation method. In the production process of metal-substituted cancrinite-like minerals, (a) after obtaining raw material aluminosilicate, (b) after acid treatment, and (c) after ion exchange, raw material aluminosilicate is treated with impurities, etc. You may wash | clean suitably for the purpose of removing. In particular, it is preferable to wash after the final stage of the raw material aluminosilicate manufacturing process, for example, after obtaining the raw material aluminosilicate and after ion exchange. The washing can be performed by, for example, filtering and washing a water suspension of the raw material aluminosilicate. Although the filter used for filtration is not specifically limited, For example, a Nutsche type, a filter press type, etc. can be used.

  Hereinafter, the present invention will be described in more detail with reference to examples. However, the scope of the present invention is not limited to such examples.

[Preparation Example 1]
94 g of sodium hydroxide was dissolved in 1000 ml of ion-exchanged water, and 130 g of nitric acid (61%) and a sodium aluminate solution (Na ₂ O = 19.8% by weight, Al ₂ O ₃ = 25.9% by weight, H ₂ O = 54.3% by weight) 127 g of water glass (Na ₂ O = 9.8% by weight, SiO ₂ = 29.6% by weight, H ₂ O = 60.6% by weight) for 1 minute. The reaction was carried out at 100 ° C. for 8 hours. After the reaction, the produced aluminosilicate particles were washed by filtration and dried at 105 ° C. for 12 hours to obtain raw material aluminosilicate particle powders. The obtained raw material aluminosilicate particles had a porous spherical shape in which acicular crystals were assembled. As a result of performing X-ray diffraction using a powder X refraction diffractometer [RINT2500, manufactured by Rigaku Corporation], the diffraction pattern is JCPDS No. It corresponded to 38-513.

[Preparation Example 2]
103 g of sodium hydroxide was dissolved in 1000 ml of ion-exchanged water, and a sodium aluminate solution (Na ₂ O = 19.8 wt%, Al ₂ O ₃ = 25.9 wt%, H ₂ O = 54.3% wt) 259 g of water glass (Na ₂ O = 9.8 wt%, SiO ₂ = 29.6 wt%, H ₂ O = 60.6 wt%) was added to the solution mixed with 157 g over 1 minute, For 2 hours. Thereafter, a solution prepared by mixing 32 g of sodium hydroxide in 110 ml of ion transmutable water and 124 g of nitric acid (61%) was added additionally over 1 minute, and further reacted at 100 ° C. for 10 hours. After the reaction, the produced aluminosilicate particles were washed by filtration and dried at 105 ° C. for 12 hours to obtain raw material aluminosilicate particle powders. The obtained raw material aluminosilicate particles had a form in which columnar and acicular crystals were assembled and developed into a tetrabod shape. The obtained raw material aluminosilicate particles were subjected to X-fold diffraction using a powder X-fold diffractometer [RINT2500, manufactured by Rigaku Corporation]. As a result, the diffraction pattern was JCPDS No. It corresponded to 38-513.

  The composition and physical properties of the raw material aluminosilicate obtained in Preparation Examples 1 and 2 are shown in Table 1 below.

100 g of the raw material aluminosilicate particles obtained in Preparation Examples 1 and 2 were suspended in 900 ml of ion-exchanged water and kept at 100 ° C. Under stirring, 61% nitric acid was added dropwise at a rate of 1 ml / min for acid treatment. The dripping amount was 2 ml per 100 g of particles. The acid treatment amount was 26 meq / 100 g particles. Next, an aqueous silver nitrate solution in which 3.94 g of silver nitrate was dissolved in 30 g of ion-exchanged water was added, and ion exchange was performed by maintaining at 100 ° C. for 1 hour. Then, it filtered, washed with water, and dried at 105 degreeC for 12 hours, and obtained the white aluminosilicate type | system | group antibacterial agent particle. The composition, physical properties, and apparent particle diameter of the obtained aluminosilicate antibacterial particles 1 and 2 are shown in Table 2 below. Moreover, scanning electron micrographs of the antibacterial agent particles 1 and 2 are shown in FIGS.

[Examples 1 and 2]
150 parts by weight of calcium carbonate having an average particle diameter of 1.0 μm, 2.5 parts by weight of calcium stearate and 100 parts by weight of the above antibacterial agent particles with respect to 100 parts by weight of linear low density polyethylene having a melt flow rate of 2.0 g / 10 min 1 (Example 1) or antibacterial agent particles 2 (Example 2) 0.4 parts by weight were mixed using a tumbler mixer, and then uniformly melt-kneaded with a twin screw extruder, melt-extruded to produce pellets did. The obtained pellets were melt-molded at 210 ° C. using a T-die extruder to obtain an unstretched film. The unstretched film was heated to 80 ° C. by a preheating roll and uniaxially stretched at a stretch ratio of 2.5 times by a roll method. Furthermore, it was heat fixed at 80 ° C. to obtain an antibacterial moisture-permeable sheet having a thickness of 20 μm.

[Comparative Example 1]
An antibacterial moisture-permeable sheet was obtained in the same manner as in Example 1 except that silver-zirconium phosphate (manufactured by Toagosei Co., Ltd., particle diameter: 1 μm) was used as the antibacterial agent particles.

[Evaluation]
About the antimicrobial moisture-permeable sheet obtained in the Example and the comparative example, the air permeability and the moisture permeability were measured by the method described above. Moreover, the antibacterial activity value was calculated | required with the following method. Further, the formability of the sheet was evaluated. These results are shown in Table 3 below.

[Antimicrobial activity value]
JIS Z 2801 “Antimicrobial processed product—antibacterial test method / antibacterial effect” was determined by a test method for plastic products and the like.

  As is clear from the results shown in Table 3, it can be seen that the sheets of the examples have high antibacterial properties while maintaining sufficient air permeability and moisture permeability. In addition, it can be seen that there is no perforation in the molding, and the moldability is good.

2 is a scanning electron micrograph of antibacterial agent particles 1. 2 is a scanning electron micrograph of antibacterial agent particles 2.

Claims (8)

  An antibacterial moisture-permeable sheet obtained by melt-kneading an antibacterial agent particle having a large number of elongated protrusions with a thermoplastic resin, pulverizing the particle, then melt-forming and then stretching.   The antibacterial moisture-permeable sheet according to claim 1, wherein an apparent particle diameter of the antibacterial agent particles before melt kneading is 5 to 100 µm, and a thickness of the sheet is 5 to 100 µm.   The antibacterial moisture-permeable sheet according to claim 1 or 2, wherein the antibacterial agent particles before melt kneading have a sea urchin shape or a tetrapod shape.   The antibacterial moisture-permeable sheet according to any one of claims 1 to 3, wherein the antibacterial agent particles are a cancrinite-like mineral containing a metal having antibacterial properties.   A mixture containing particles having a number of elongated protrusions and a thermoplastic resin, the mixture amount of which is 0.05 to 5 parts by weight with respect to 100 parts by weight of the thermoplastic resin, is melt-kneaded, and the particles are melt-kneaded. A method for producing a sheet-like molded product, in which a melt-kneaded product is melt-formed after being pulverized.   The production method according to claim 5, wherein the apparent particle diameter of the particles before melt kneading is 5 to 100 µm, and the thickness of the sheet-like molded product is 5 to 100 µm.   The manufacturing method according to claim 5 or 6, wherein the particles before melt-kneading have a sea urchin shape or a tetrapod shape. The production method according to claim 5, wherein the particles are a cancrinite-like mineral containing a metal having antibacterial properties.