JP4575201B2 - Antibacterial / water-absorbing thermoplastic resin foam, production method thereof and use thereof - Google Patents

Description

  The present invention relates to an antibacterial / water-absorbing thermoplastic resin foam and a method for producing the same. The antibacterial / water-absorbing thermoplastic resin foam of the present invention is used for bathroom components, foot-wiping mats, heat insulating materials for homes, wallpaper, condensation water-absorbing tape, and the like.

  Polystyrene resins are easy to produce in various forms such as foamed sheets, boards, and boxes, and the resulting foamed molded products have heat insulation properties, light weight and appropriate rigidity. Because it has, it is widely used in various fields. However, the polystyrene resin foam has water repellency and does not absorb moisture. For this reason, problems such as generation of mold and bad odor occur in an environment where water droplets are generated. Thus, attempts have been made to impart water absorbency as a further function addition while taking advantage of the excellent properties of polystyrene resin foam (see, for example, Patent Documents 1 to 5).

Patent Document 1 discloses an open cell styrene resin foam layer having a density of 0.3 to 0.03 g / cm ³ and an open cell ratio of 50 to 95%, and a density of 0.2 to 0.05 g / cm 2. There is disclosed a styrene resin foam laminated sheet characterized by laminating a closed cell styrene resin foam layer having a cm ³ and an open cell ratio of 40% or less. In this Patent Document 1, it is preferable to make a small hole in the surface skin in order to increase the water absorption capability, and in order to break the skin, the needle roll or the metal rotation is made while the sheet is rolled up in a roll shape. It is described that the skin is continuously broken by arranging a brush or the like.

  Patent Document 2 discloses a container lid made of a polystyrene-based resin foam sheet having an open cell ratio of 50% or more, and a skin layer of the foam sheet itself formed at the time of manufacture on the side facing the container and optionally laminated. A container lid is disclosed in which a moisture passage is formed by breaking or removing at least a part of the coated layer.

  In Patent Document 3, 0.5 to 5 mass of surfactant is added to 100 mass parts of a mixed resin composition obtained by adding a hydrogenated copolymer of styrene and conjugated diene and a polyolefin resin to a polystyrene resin. A foam having an open cell ratio of 60% or more and a water absorption of 10% or more obtained by foaming a resin composition containing a part of the hydrogenated product of the copolymer of styrene and conjugated diene. A foam having a durometer type A hardness (HDA) value of 20 to 90 described in JIS K 7215 is disclosed.

  Patent Document 4 discloses a polystyrene resin foam sheet laminate in which a non-foamable resin is laminated on one surface of a base made of a polystyrene resin foam sheet containing a water-absorbent resin, and the non-foamed resin is laminated. The ratio of the propagation speed of the longitudinal wave of 14 kHz between the direction of extrusion of the surface layer on the surface of the substrate opposite to the surface and the direction perpendicular to the direction of extrusion becomes 0.8 to 0.9 or 1.1 to 1.2. And the surface of the base is provided with a plurality of cuts at a depth of ½ to 2/3 of the thickness of the base. A laminate is disclosed.

Patent Document 5 is a lid that covers a top surface of a food container that contains a food containing moisture, and the lid has a large number of fine recesses on the inner surface side of the food container. A food container lid is disclosed.
JP 9-254294 A JP-A-10-129743 JP 2004-352927 A JP-A-10-202802 Japanese Utility Model Publication No. 6-16250

However, the above-described conventional technique has the following problems.
The prior art described in Patent Document 1 describes the improvement in water absorption by drilling with a pin. However, if the surface tension is strong like a water droplet, a water droplet gets on the top of the hole just by making a small hole. It has been found that when the force becomes equal in such a state, it may not be absorbed.
In the prior art described in Patent Document 2, it is described that a cut is made or a small hole is made, but the cut reduces the physical strength in a certain direction, and the surface layer is to avoid this. When an incision was made as thinly as possible, a sufficient water absorption effect could not be obtained due to the repulsion of the surface skin.
In the prior art described in Patent Document 3, it is described that the surface layer of the foam is damaged in addition to providing the small holes. However, this has a risk that a large amount of shavings may be generated or the strength may be significantly reduced.
In the prior art described in Patent Document 4, there is a description of making a cut similarly to Patent Document 2, and there is a description of a preferable cutting shape and a cutting depth. However, there is a drawback that bending strength is extremely lowered in a certain direction in which cutting is made.
Patent Document 5 describes that, regarding the recessed portion, the cross-sectional area may gradually increase toward the inside of the food container, or may gradually decrease, or the cross-sectional area may not be changed. Has been. However, in such a simple hole (concave part), if the surface tension is strong like a water drop as in the above-mentioned Patent Document 1, if the force is equalized in a state where the water drop is on the top of the hole, it will not be absorbed There is a problem that occurs.

  Furthermore, each of the above-described conventional techniques only provides a water absorbing function to the foam. When the water absorbent foam is used for a long period of time, for example, bathroom components, foot cleaning mats, residential insulation, wallpaper, condensation When used for a water-absorbing tape or the like, there is a problem that mold and bacteria propagate in the foam and become unsanitary, and a bad odor is generated.

  The present invention has been made in view of the above circumstances, and can easily absorb water adhering to water droplets while maintaining excellent mechanical strength, and can also prevent the growth of mold and bacteria for a long period of time. It aims at provision of a plastic resin foam and its manufacturing method.

In order to achieve the above-mentioned object, the present invention has an antibacterial / antibacterial agent which has a large number of small holes communicating from the surface of at least a part of the thermoplastic resin foam body to the inside, and an antibacterial agent is contained at least around the small holes A water absorbent thermoplastic resin foam, wherein the small hole has at least a small hole upper portion and a small hole lower portion having different inclination angles, and the small hole upper portion has an inclined shape whose diameter is expanded toward the surface. And providing an antibacterial / water-absorbing thermoplastic resin foam, wherein the thermoplastic resin foam main body is a polystyrene resin foam .

  In the antibacterial / water-absorbing thermoplastic resin foam of the present invention, the small hole lower part is preferably bottomed.

  In the antibacterial / water-absorbing thermoplastic resin foam of the present invention, it is preferable to have a crease between the small hole upper part and the small hole lower part.

  In the antibacterial / water-absorbent thermoplastic resin foam of the present invention, it is preferable that an inclination angle formed by an inclined surface of the upper portion of the small hole with respect to the surface is in a range of 20 ° to 70 °.

  In the antibacterial / water-absorbing thermoplastic resin foam of the present invention, the lower end diameter of the small hole upper part / the distance of the inclined surface of the small hole upper part is preferably in the range of 0.2 to 1.

  In the antibacterial / water-absorbing thermoplastic resin foam of the present invention, the open cell ratio of the thermoplastic resin foam body is preferably 50 to 80%.

  In the antibacterial / water-absorbing thermoplastic resin foam of the present invention, it is preferable that a thermoplastic resin foam having an open cell ratio of 30% or less is laminated on the thermoplastic resin foam main body.

  In the antibacterial / water-absorbing thermoplastic resin foam of the present invention, it is preferable that a non-foamed resin layer is laminated on at least a part of the surface of the thermoplastic resin foam main body, and the small holes are provided therein.

  In the antibacterial / water-absorbing thermoplastic resin foam of the present invention, the antibacterial agent is preferably any one of a silver antibacterial agent, a copper antibacterial agent and an iodine antibacterial agent.

  The present invention also provides a V-shaped or pyramid having a tip angle of 30 ° to 150 ° on at least a part of the surface of a thermoplastic resin foam body obtained by foaming a thermoplastic resin containing an antibacterial agent and a foaming agent. At least a small hole upper portion and a small hole lower portion having different inclination angles, and the small hole upper portion is provided with a large number of small holes having an inclined shape whose diameter is expanded toward the surface. Provided is a method for producing an antibacterial / water-absorbing thermoplastic resin foam, which is characterized by obtaining the antibacterial / water-absorbing thermoplastic resin foam according to the present invention.

  The present invention also provides a small hole upper portion and a small hole having different inclination angles by pressing a V-shaped or cone-shaped pressing blade having a tip angle of 30 ° to 150 ° on at least a part of the surface of the thermoplastic resin foam main body. The upper portion of the small hole is provided with a large number of small holes having an inclined shape whose diameter is expanded toward the surface, and then the liquid containing the antibacterial agent is absorbed from the small hole and dried. Provided is a method for producing an antibacterial / water-absorbing thermoplastic resin foam, which is characterized by obtaining the antibacterial / water-absorbing thermoplastic resin foam according to the present invention.

  Further, the present invention presses a V-shaped or cone-shaped pressing blade having a tip angle of 30 ° to 150 ° with a liquid containing an antibacterial agent attached to at least a part of the surface of the thermoplastic resin foam main body, It has at least a small hole upper part and a small hole lower part having different inclination angles, and the small hole upper part is provided with a large number of small holes having an inclined shape whose diameter is expanded toward the surface. Provided is a method for producing an antibacterial and water-absorbent thermoplastic resin foam characterized by obtaining a thermoplastic resin foam.

  The present invention also provides an antibacterial / water-absorbing thermoplastic resin foam according to the present invention described above, wherein the foam is an antibacterial / water-absorbing thermoplastic resin foam.

  The present invention also provides an antibacterial / water-absorbing thermoplastic resin foam sheet molded article obtained by molding the antibacterial / water-absorbing thermoplastic resin foam sheet according to the present invention.

  The present invention also provides an antibacterial / water-absorbing thermoplastic resin foam board according to the present invention, characterized in that it has a thick plate shape.

  Moreover, this invention provides the bathroom component which consists of an antibacterial and water absorbing thermoplastic resin foam concerning this invention mentioned above.

  The present invention also provides a foot-wiping mat comprising the antibacterial / water-absorbing thermoplastic resin foam according to the present invention.

  The antibacterial / water-absorbing thermoplastic resin foam of the present invention has at least a small hole upper portion and a small hole lower portion having different inclination angles on the surface of the thermoplastic resin foam main body, and the small hole upper portion faces the surface. Since a large number of small holes having an inclined shape with an enlarged diameter are provided, if water droplets adhere to the opening above the small holes, the water drops enter the opening above the wide small holes even if surface tension is applied. , Absorbed into the small holes. Moreover, even if many small holes are provided on the surface of the thermoplastic resin foam main body, the mechanical strength such as the bending strength of the thermoplastic resin foam main body does not decrease so much. Furthermore, since an antibacterial agent is contained around the small holes, it is possible to prevent mold and bacteria from proliferating for a long period of time even in a state where moisture is accumulated in the small holes and the thermoplastic resin foam main body. Therefore, according to the present invention, an antibacterial and water-absorbing thermoplastic resin that can be easily absorbed by water adhering to water droplets while maintaining excellent mechanical strength, and can prevent the growth of mold and bacteria for a long period of time. A foam can be provided.

  The method for producing an antibacterial / water-absorbing thermoplastic resin foam of the present invention presses a V-shaped or cone-shaped pressing blade having a tip angle of 30 ° to 150 ° on at least a part of the surface of the thermoplastic resin foam main body. The antibacterial / water-absorbing thermoplastic resin foam according to the present invention described above can be obtained by a simple operation, so that water adhering to water droplets can be easily absorbed while maintaining excellent mechanical strength. Moreover, it is possible to provide an antibacterial / water-absorbent thermoplastic resin foam that can prevent the growth of mold and bacteria for a long period of time at low cost and with high production efficiency.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
1 and 2 show an embodiment of the antibacterial / water-absorbing thermoplastic resin foam of the present invention, and FIG. 1 shows an electron microscope observation image of a cross section of the main part of the antibacterial / water-absorbing thermoplastic resin foam 1. FIG. 2 and FIG. 2 are schematic views of the antibacterial / water-absorbing thermoplastic resin foam 1, FIG. 2 (a) is a schematic cross-sectional view of the main part, and FIG. 2 (b) is a plan view of the main part.

  The antibacterial / water-absorbent thermoplastic resin foam 1 of the present embodiment has a large number of small holes 3 communicating from at least a part of the surface of the thermoplastic resin foam main body 2 to the inside, and the small holes 3 have an inclination angle. It has at least a different small hole upper part 4 and a small hole lower part 5, and the small hole upper part 4 has an inclined surface 6 whose diameter is expanded toward the surface.

  Examples of the thermoplastic resin that is the material of the thermoplastic resin foam body 2 include polystyrene resins, polyethylene resins, polypropylene resins, and polyethylene terephthalate (PET) resins. Among these, heat insulation is achieved at a high expansion ratio. Polystyrene resins are preferred because they can produce a foam molded article having excellent strength and good moldability. Examples of polystyrene resins include styrene monomers such as styrene, methyl styrene, ethyl styrene, isopropyl styrene, dimethyl styrene, paramethyl styrene, chlorostyrene, bromostyrene, vinyl toluene, vinyl xylene homopolymer, or the styrene. A copolymer of a vinyl monomer and another monomer such as acrylonitrile, methacrylonitrile, acrylic acid, methacrylic acid, methyl methacrylate, maleic anhydride, butadiene and other vinyl monomers can be used. . Among them, polystyrene resin, styrene-maleic anhydride copolymer, styrene-acrylic acid copolymer, high impact polystyrene resin (HIPS), styrene-acrylonitrile copolymer, acrylonitrile-butadiene-styrene terpolymer, etc. Is preferably used. These can be used alone or in combination.

  A small amount of a rubbery material may be added to the polystyrene resin for modification. Rubber-like materials include styrene-butadiene block copolymers, styrene-butadiene random copolymers, styrene-isoprene block copolymers, styrene-isoprene random copolymers, low cis-polybutadiene, and hydrogenated copolymers thereof. A coalescence or the like can be used.

As the foaming agent used in the production of the thermoplastic resin foam main body 2, any conventionally known foaming agent in the field of thermoplastic resin foam production can be used, and a decomposable foaming agent, a gas or a volatile foaming agent can be used. . Examples of the decomposable foaming agent include inorganic decomposable foaming agents such as ammonium carbonate, sodium bicarbonate, ammonium bicarbonate, ammonium nitrite, calcium azide, and sodium azide, azodicarbonamide, azobissulfonylamide, azobisisobutyrate. Azo compounds such as ronitrile and diazoaminobenzene, nitroso compounds such as N, N′-dinitrosopentanemethylenetetramine and N, N′-dimethyl-N, N′-dinitrosotephthalamide, benzenesulfonyl hydrazide, p-toluene Sulfonyl hydrazide and p, p′-oxybisbenzenesulfonyl semicarbazide, p-toluenesulfonyl semicarbazide, trihydrazinotriazine, barium azodicarboxylate and the like can be used. These foaming agents may be used alone or in combination. Furthermore, a known foaming aid can be added to adjust the decomposition temperature, the amount of gas generated and the decomposition rate.
Nitrogen, carbon dioxide, propane, n-butane, i-butane, methyl ether, etc. can be used as the gas blowing agent. Here, the gas means a gas at normal temperature (25 ° C.) and normal pressure (1 atm). On the other hand, examples of the volatile blowing agent include ether, petroleum ether, acetone, pentane, isopentane, hexane, isohexane, heptane, isoheptane, benzene, toluene and the like. Water can also be used. These can also be used in combination. Of the above blowing agents, butane is preferred.

  The antibacterial agent used in the present invention is preferably one that can prevent mold and bacteria from proliferating over a long period of time even when the thermoplastic resin foam main body 2 is in a state of containing moisture. More preferably, it is one of an antibacterial agent and an iodine antibacterial agent. Among these antibacterial agents, silver antibacterial agents are preferable. Examples of the silver antibacterial agent include silver / hydroxyapatite, silver complex salt / silica gel, silver / zeolite, silver / calcium phosphate, and the like. These silver-based antibacterial agents can be newly prepared and used, or appropriate commercial products can be used.

  The antibacterial agent may be contained at least around the small holes 3, may be a part of the periphery of the thermoplastic resin foam main body 2 small holes 3, or may be included in the entire thermoplastic resin foam main body 2. An antibacterial agent may be included. Further, in the case of the thermoplastic resin foam body 2 obtained by laminating the open cell layer 8 and the closed cell layer 9, the open cell layer 8 alone can contain an antibacterial agent.

The manufacturing method of the thermoplastic resin foam main body 2 can be appropriately selected depending on the shape of the thermoplastic resin foam main body 2. As a method for producing the sheet-like thermoplastic resin foam main body 2, a thermoplastic resin and an additive that is added as necessary are put into an extruder, heated and melted in the extruder, and the volatile foaming agent is used. It can be produced by mixing, kneading and extruding from a circular die attached to the tip of the extruder, foaming, immediately cooling with a cooling mandrel, cutting into a sheet, and winding up the obtained sheet. As a method for producing the board-like thermoplastic resin foam main body 2, a thermoplastic resin and an additive that is added as necessary are put into an extruder, and the mixture is heated and melted in the extruder, and the volatile foaming agent is used. It can be produced by mixing, kneading and extruding from a T-die attached to the tip of the extruder, foaming, cooling with a cooling roll, and cutting.
Moreover, as a method of laminating a non-foamed resin layer on at least a part of the surface of the thermoplastic resin foam main body 2, a method of laminating a non-foamed resin film by an adhesive or heat fusion, A method of laminating by a coextrusion method performed in a die can be applied. The strength is improved by laminating a non-foamed resin layer on the surface of the thermoplastic resin foam main body 2.

  In the case of manufacturing a thermoplastic resin foam body 2 such as a box shape, expandable thermoplastic resin resin particles (also referred to as expanded beads) made of a thermoplastic resin impregnated with a foaming agent are used. The particles are heated and foamed by steam heating or the like to form pre-foamed particles. The mold is filled with the pre-foamed particles in a cavity having a cavity that matches the target shape to be manufactured, and then the mold is molded by steam heating or the like. The pre-expanded particles can be foamed, and the surfaces of the adjacent pre-expanded particles can be fused together, and then cooled to take out the foam-molded product from the mold.

  The antibacterial / water-absorbing thermoplastic resin foam 1 of the present embodiment has a small hole having the shape shown in FIGS. 1 and 2 on at least a part of the surface of the thermoplastic resin foam main body 2 obtained as described above. 3 is provided. In the present embodiment, the small hole 3 has a small hole upper portion 4 and a small hole lower portion 5 having different inclination angles, and the small hole lower portion 5 has a bottom. The small hole upper portion 4 has an inclined surface 6 whose diameter is expanded toward the surface.

  The inclination angle θ formed by the inclined surface of the small hole upper portion 4 with respect to the surface of the thermoplastic resin foam main body 2 is preferably in the range of 20 ° to 70 °. If the inclination angle θ is less than 20 °, the inclination of the inclined surface 6 is too gentle, and when water droplets adhere to the small hole openings, it becomes difficult for the water droplets to flow into the small holes 3 and the water absorption performance deteriorates. In addition, when the inclination angle θ exceeds 70 °, the inclined surface 6 is so inclined that, like a needle hole opened perpendicularly to the surface, when a water droplet adheres to the small hole opening, Becomes difficult to flow into the small holes 3 and the water absorption performance deteriorates.

  In the present embodiment, the small hole 3 has a narrowed portion 10 having a reduced diameter between the small hole upper portion 4 and the small hole lower portion 5. The small hole lower part 5 below the squeezed part 10 is a bottomed cavity part 5a. The hollow portion 5a stores the absorbed water and causes the open cell layer 8 of the thermoplastic resin foam body 2 to absorb the water.

  In the small hole 3 shown in FIG. 2, the small hole depth A, the distance B of the inclined surface, the lower end diameter D of the small hole upper part, the width E of the small hole upper part 4 and the upper end diameter F of the small hole lower part 5 are particularly limited. However, it is preferable that the value of D / B, which is the ratio of the lower end diameter D of the small hole upper portion 4 and the distance B of the inclined surface, is in the range of 0.2 to 1. More preferably, it is the range of 0.3-0.7. If the value of D / B is less than 0.2, B will be too large for D, leading to a decrease in strength. If the value of D / B exceeds 1, B will be too small for D. The effect of providing an inclined surface is reduced. The small hole depth A is preferably in the range of 0.5 to 5 mm, the distance B of the inclined surface is preferably in the range of 0.1 to 10 mm, and the lower end diameter D of the small hole upper portion is in the range of 0.1 to 7 mm. Preferably, the width E of the small hole upper portion 4 is preferably in the range of 0.5 to 10 mm, and the upper end diameter F of the small hole lower portion 5 is preferably in the range of 0.5 to 10 mm.

  In the present embodiment, the small hole 3 has a substantially arrow shape with a skirt spread as shown in FIG. 2A and a planar shape formed in a rectangular shape as shown in FIG. 2B. Yes. The shape of the small hole 3 includes at least a small hole upper part 4 and a small hole lower part 5 having different inclination angles, and the small hole upper part 4 has an inclined surface 6 whose diameter is expanded toward the surface. What is necessary is just and it is not limited to this illustration.

3 to 9 illustrate other shapes of the small holes 3.
As shown in FIG. 3A, the small hole 3 illustrated in FIG. 3 has a substantially arrow shape with a skirt spread like the small hole 3 shown in FIG. As shown, it is formed concentrically.
The small hole 3 illustrated in FIG. 4 includes a small-diameter lower part 5 formed in a vertical square hole shape and a small hole upper part 4 having an inclined surface 6 only on one side of the upper part.
The small hole 3 illustrated in FIG. 5 includes a small-diameter lower part 5 formed in a vertical square hole shape, and a small-hole upper part 4 having inclined surfaces 6 on both sides of the upper part.
The small hole 3 illustrated in FIG. 6 includes a small-diameter lower part 5 having a V-shaped cross section and a small hole upper part 4 having an inclined surface 6 on the upper part.
The small hole 3 illustrated in FIG. 7 includes a small-diameter lower part 5 having a hollow part 5a having a substantially square shape in cross section, a small-hole upper part 4 having an inclined surface 6 on the upper part, and a bend part 10 provided therebetween. It is made up of.
The small hole 3 illustrated in FIG. 8 includes a small diameter lower part 5 provided through the thermoplastic resin foam main body 2, and a small hole upper part 4 having an inclined surface 6 on the upper part of the small diameter lower part 5 on one surface side. It is made up of.
The small hole 3 illustrated in FIG. 9 includes a small-diameter lower part 5 provided through the thermoplastic resin foam main body 2 and a small-hole upper part 4 having an inclined surface 6 on the opening side of the small-diameter lower part 5 on both sides. It is made up of.

  In the antibacterial / water-absorbent thermoplastic resin foam 1 of the present embodiment, the thermoplastic resin foam main body 2 preferably has an open cell ratio of 50 to 80%. A foam having an open cell ratio of 50 to 80% allows water and other liquids to circulate in the narrow bubble passage and absorbs water droplets on one side communicated by capillary action to the other side. It is preferable as a base material for the antibacterial / water-absorbing thermoplastic resin foam 1. When the open cell ratio is less than 50%, the water absorption performance of the small holes 3 is deteriorated. On the other hand, when the open cell ratio exceeds 80%, the mechanical strength of the thermoplastic resin foam main body 2 is decreased and the container or the like Since it becomes difficult to manufacture this, it is not preferable.

  One method for producing the thermoplastic resin foam main body 2 having an open cell ratio of 50 to 80%, particularly a polystyrene resin foam sheet (hereinafter referred to as an open cell sheet) is a polystyrene resin in an extruder. And injecting a foaming agent composed of aliphatic or alicyclic hydrocarbons such as butane and pentane from the middle of the extruder at a rate of 0.3 to 1.0 mol per kg of polystyrene resin, An open cell sheet can be obtained by setting and extruding a resin temperature about 10 ° C. higher than the resin temperature at the time of extrusion at which a polystyrene resin foam sheet having an open cell ratio of 30% or less is obtained. As the foaming agent, an inorganic foaming agent composed of nitrogen, carbon dioxide, air, water, or a mixture thereof may be mixed with the above-mentioned foaming agent.

  This open cell type sheet has a large water absorption capacity, and it is preferable that this water absorption capacity is large. This water absorption capacity can be expressed quantitatively as water absorption in accordance with JIS A 9511. Specifically, a 100 × 100 mm square sample is cut out from the open cell type sheet as it is, this sample is immersed in water at room temperature for 24 hours, and the attached surface water is wiped off with gauze, etc. The weight of the sample is measured, the rate of increase with respect to the original weight of the sample is calculated, and this rate of increase is taken as the water absorption rate. The open cell sheet preferably has a water absorption of 30% or more. This is because if the water absorption is less than 30%, moisture cannot be effectively taken into the open cell sheet through the small holes 3.

Moreover, in order to improve the water absorption capacity of the open cell type sheet, it is preferable to contain 1.0 to 20.0% by mass of inorganic powder in the open cell type sheet. If the inorganic powder is less than 1.0% by mass, there is no effect in improving the water absorption capacity, and if it exceeds 20.0% by mass, the water absorption capacity is improved, but the appearance of the sheet is remarkably deteriorated. As the inorganic powder used for this, calcium carbonate, talc or the like is preferably used. The inorganic powder is also effective as a bubble regulator. Further, increasing the water absorption capacity of the open cell type sheet can also be achieved by including 1.0 to 20.0% by mass of a water-absorbing polymer in the open cell type sheet.
It can also be achieved by adding a surfactant to the surface or inside of the open cell sheet.

  As a further preferred embodiment of the thermoplastic resin foam main body 2, the open-cell type sheet described above and a thermoplastic resin foam sheet having an open cell ratio of 30% or less (hereinafter referred to as a closed-cell type sheet) are laminated. A laminated sheet. A method for producing a thermoplastic resin foam main body 2 (hereinafter referred to as a foamed laminated sheet) having an open cell layer made of an open cell type sheet and a closed cell layer made of a closed cell type sheet and having a sheet shape. For example, the method described in Patent Document 1 (Japanese Patent Laid-Open No. 9-254294) can be used. That is, a polystyrene resin is introduced into an extruder, a foaming agent is mixed into the polystyrene resin melted in the extruder, and a resin containing the foaming agent is extruded into the atmosphere from a die attached to the tip of the extruder. Can be made by However, as described above, consideration should be given to the formation of open cells in the part where the open cell layer is formed, and care must be taken so as to generate closed cells in the part where the closed cell layer is formed. Don't be. The extrusion foaming is preferably performed by coextrusion performed in one mold. Alternatively, a continuous cell type sheet and a closed cell type sheet can be prepared separately, and both can be overlapped and integrated by an adhesive or heat fusion to form a foam laminated sheet.

  The antibacterial / water-absorbing thermoplastic resin foam 1 shown in FIG. 1 uses a foamed laminated sheet produced by the coextrusion method described above as the thermoplastic resin foam main body 2 and has the aforementioned small holes 3 provided on the surface thereof. It is. In the thermoplastic resin foam main body 2 shown in FIG. 1, reference numeral 8 is an open cell layer, and 9 is a closed cell layer. Moreover, the surface skin layer 7 formed by rapidly cooling the surface at the time of manufacturing the foamed laminated sheet is formed on the upper and lower surfaces of each laminated layer. The surface skin layer 7 formed on the surface of the open cell layer 8 may have finer bubbles than the open cell layer 8 and the open cell rate may be reduced. The small holes 3 are provided on the open cell layer 8 side, and are provided through the surface skin layer 7 and the open cell layer 8.

  The antibacterial / water-absorbing thermoplastic resin foam 1 shown in FIG. 1 has a water-absorbing surface on the side where the small holes 3 are provided. When water droplets adhere to this surface, the water droplets flow into the inclined surface 6 of the small hole 3. Without this inclined surface 6, even if a water droplet adheres to the opening of the small hole 3, it is difficult to flow into the small hole due to the surface tension of the water droplet. On the other hand, the antibacterial / water-absorbing thermoplastic resin foam 1 shown in FIG. 1 has an inclined surface 6 at the opening portion (small hole upper portion 4) of the small hole 3, so that water droplets entering the inclined surface 6 The inclined surface 6 enters the small hole 3 against the surface tension and is absorbed by the open cell layer 8. At the time of water absorption, since the drooping portion 10 is provided between the small hole upper portion 4 and the small hole lower portion 5, water droplets adhering to the inclined surface 6 are caused by the capillary phenomenon generated in the drowning portion 10, and the small hole upper portion 4. To the small hole lower part 5 is promoted. Moisture that has flowed into the small hole lower portion 5 side accumulates in the cavity 5a and is quickly diffused into the open cell layer 8 through thin open cells of the open cell layer 8 communicating with the cavity 5a. As described above, the antibacterial / water-absorbing thermoplastic resin foam 1 shown in FIG. 1 can exhibit excellent water absorption performance on the surface on the side where the small holes 3 are provided.

  In addition, the antibacterial / water-absorbing thermoplastic resin foam 1 shown in FIG. 1 is a thermoplastic resin obtained by laminating a foam-laminated sheet in which a closed cell layer 9 excellent in mechanical strength and an open-cell layer 8 excellent in water absorption are laminated. Since it is used as the foam body 2 and the small holes 3 described above are provided on the surface of the open cell layer 8, the small holes 3 and the open cell layer 8 can exhibit excellent water absorption performance, and the closed cell layer 9. Can be applied to applications that require a certain level of mechanical strength, such as bathroom components and foot-wiping mats. Become. Further, by adding an antibacterial agent to the open cell layer 8 side, when the small holes 3 are provided on the open cell layer 8 side to absorb water, water remains in the small holes 3 or the open cell layer 8. In addition, the antibacterial agent can prevent the growth of mold and bacteria over a long period of time, and can prevent the generation of malodor and deterioration of the appearance due to mold growth.

  Next, an example of a method for producing the antibacterial / water-absorbent thermoplastic resin foam 1 will be described with reference to FIGS. In this example, the above-mentioned foamed laminated sheet is used as the thermoplastic resin foam main body 2, and the small pores 3 are provided on the surface of the open cell layer 8 side, and the antibacterial / water-absorbing thermoplastic resin foam 1 shown in FIG. The case of manufacturing the is illustrated. FIG. 10 is a cross-sectional view showing a state in which a triangular pressing blade 11 is pressed on the surface of the thermoplastic resin foam main body 2 made of a foamed laminated sheet on the open cell layer 8 side. 11 shows a gear set in a drilling jig used for drilling to form the small hole 3, FIG. 11 (a) is a side view of the gear 12a of the first example, (b) is a front view, and (c). Is a side view of the gear 12b of the second example, and (d) is a front view. FIG. 12 is an external view of a drilling jig 13 used for drilling to form the small holes 3. FIG. 13 is a perspective view showing a drilling process for forming the small holes 3 in the foamed laminated sheet 15. FIG. 14 is a cross-sectional view showing a state in which the small holes 3 are formed after making holes in the foamed laminated sheet 15.

  In the manufacturing method of this example, a foamed laminated sheet 15 is used as the thermoplastic resin foam main body 2, and the foamed laminated sheet 15 is continuously passed between the punching jig 13 and the roller 14 as shown in FIG. Then, a V-shaped or cone-shaped pressing blade having a tip angle of 30 ° to 150 ° is pressed against the surface of the foamed laminated sheet 15 on the side of the open cell layer 8 so that at least a small hole upper portion and a small hole lower portion having different inclination angles are provided. The small hole upper portion is provided with a large number of small holes 3 having an inclined shape whose diameter is expanded toward the surface to produce an antibacterial / water absorbent foam sheet 16 (antibacterial / water absorbent thermoplastic resin foam 1). The antibacterial / water-absorbent foam sheet 16 that has finished drilling is wound around a roller.

  As shown in FIG. 12, the drilling jig 13 used in this drilling process has a structure in which a plurality of gears 12A and 12B are fixed to a shaft at equal intervals or randomly. As shown in FIG. 11, the gears 12 </ b> A and 12 </ b> B have a substantially disk shape in which a large number of pressing blades 11 are provided on the outer periphery. The pressing blade 11 has a V shape or a cone shape with tip angles θ1 and θ2 of 30 ° to 150 °. The dimensions of each part of the gears 12A and 12B are not limited, but the cutting edge outer diameters G1 and G2 are 100 to 300 mm, the base outer circumferences H1 and H2 are 5 to 20 mm smaller than G1 and G2, and the thicknesses I1 and I2 are 0. About 5-10 mm is preferable.

  When the pressing blade 11 is pressed against the surface of the foamed laminated sheet 15 (thermoplastic resin foam main body 2) on the open cell layer 8 side, the pressing blade 11 becomes the surface of the thermoplastic resin foam main body 2 as shown in FIG. The skin layer 7 and the open cell layer 8 are penetrated, and the tip reaches the closed cell layer 9. When the surface skin layer 7 and the open cell layer 8 are pierced by the pressing blade 11, they are separated from each other due to the difference in mechanical strength between the two layers. That is, since the surface skin layer 7 is denser than the open cell layer 8, the mechanical strength is high, and when these layers are pierced by the pressing blade 11, the open cell layer 8 is easily pierced. Whereas the surface skin layer 7 resists the pressing, the boundary between the two layers peels off.

  When the pressing blade 11 is separated, in the V-shaped small holes formed on the surface of the thermoplastic resin foam main body 2, the bottom of the small holes rises due to the repulsion of the closed cell layer 9, as shown in FIG. The surface skin layer 7 is raised to form the bent portion 10, and the small hole 3 having the shape shown in FIGS. 1 and 2 is formed.

  The number and arrangement of the small holes 3 provided on the surface of the foam laminated sheet 15 (thermoplastic resin foam main body 2) are the number of press blades 11 formed on the gears 12A and 12B, the tip angle, and the gear 12A to the drilling jig 13. , 12B can be easily changed by appropriately setting the mounting interval. For example, a large number of small holes 3 can be provided on the surface of the thermoplastic resin foam main body 2 in a lattice shape, a staggered shape, or at random. Further, a plurality of types of gears 12A and 12B having different numbers of formed pressing blades 11 and tip angles may be alternately attached to the drilling jig 13, and the small holes 3 having different sizes and shapes may be provided in the foamed laminated sheet 15.

  In the method for producing an antibacterial / water-absorbing thermoplastic resin foam of the present invention, the following (1) to (3) are methods for containing an antibacterial agent at least around the small holes 3 of the thermoplastic resin foam main body 2. This method is preferable.

(1) On the surface of a thermoplastic resin foam body 2 obtained by foaming a thermoplastic resin containing an antibacterial agent and a foaming agent, a V-shaped or cone-shaped pressing blade 11 having a tip angle of 30 ° to 150 °. The small hole upper part 4 and the small hole lower part 5 having different inclination angles are provided, and the small hole upper part 4 is provided with a large number of small holes 3 having an inclined shape whose diameter is expanded toward the surface.
The antibacterial agent used in the method (1) is preferably a powder such as silver or zeolite, and an antibacterial agent having an average particle size of 1.0 μm or less so as to be uniformly dispersed in the thermoplastic resin. The addition amount of the antibacterial agent is preferably in the range of 0.3 to 1.5 parts by mass with respect to 100 parts by mass of the thermoplastic resin. In the method (1) in which the antibacterial agent is contained in the thermoplastic resin foam main body 2, the antibacterial agent can be contained in both the open cell layer 8 and the closed cell layer 9 of the thermoplastic resin foam main body 2, An antibacterial agent can be contained only in the open cell layer 8 side where the small holes 3 are provided. In this method (1), since the thermoplastic resin foam body 2 itself contains an antibacterial agent, not only the small holes 3 but also the local area of the thermoplastic resin foam body 2 that may come into contact with moisture for a long time. Prevents mold and bacteria from breeding. Further, since the thermoplastic resin foam main body 2 itself contains an antibacterial agent, the antibacterial agent hardly flows out, and the antibacterial power can be maintained for a long time.

(2) A small hole upper portion 4 and a small hole lower portion 5 having different inclination angles by pressing a V-shaped or conical pressure blade 11 having a tip angle of 30 ° to 150 ° against the surface of the thermoplastic resin foam body 2. The small hole upper part 4 is provided with a large number of small holes 3 having an inclined shape whose diameter is expanded toward the surface, and then a liquid containing an antibacterial agent is absorbed from the small holes 3 and dried.
As a liquid containing an antibacterial agent used in the method (2), for example,
(A) a liquid in which an antibacterial agent, a dispersion medium such as water, and a surfactant are mixed and dispersed;
(B) A solution obtained by adding a polymer such as an acrylic resin or a water-soluble polymer or a thickener to the antibacterial agent to the foam wall surface,
Etc. can be used. After providing the small holes 3, the liquid is brought into contact with the small holes 3 by a method such as spray coating of this liquid or immersing the thermoplastic resin foam main body 2 in the liquid. Thereafter, by drying the thermoplastic resin foam main body 2, the antibacterial agent in the liquid is left attached to the foam wall surface of the open cell layer 3 around the small holes 3. At this time, when the liquid (b) is used, the antibacterial agent particles can be adhered to the foam wall surface by a polymer or the like, so that the outflow of the antibacterial agent can be suppressed. In this method (2), an antibacterial agent can be contained in the entire open cell layer 8 through the small holes 3, but the antibacterial agent can be easily contained only around the small holes 3, and the antibacterial agent is wasted. Can be eliminated.

(3) Press the V-shaped or cone-shaped pressing blade 11 having a tip angle of 30 ° to 150 ° with a liquid containing an antibacterial agent attached to the surface of the thermoplastic resin foam main body 2, and the inclination angles are different. A method of providing a plurality of small holes 3 each having at least a small hole upper portion 4 and a small hole lower portion 5 and having an inclined shape in which the small hole upper portion 4 is expanded in diameter toward the surface.
The liquid to be attached to the pressing blade 11 by the method (3) preferably has a higher viscosity than the liquids (a) and (b) used in the method (2). It is preferable to use a liquid prepared by appropriately blending an agent, a film-forming agent, a thickener and the like, for example, to have a viscosity equivalent to that of printing ink or adhesive. The method of attaching the liquid to the pressing blade 11 is not particularly limited, and any one of liquid dropping by spraying the spraying blade 11 at a timing other than drilling by the pressing blade 11, spray coating, and liquid supply by bringing the liquid supply roller into contact with the pressing blade 11. It can apply | coat by the method of. The liquid adhering to the pressing blade 11 adheres to the surface of the formed small hole by punching with the press 11 (see FIG. 11), adheres in a film shape and remains in the small hole 3, and silver ions, etc. The antibacterial component is released over a long period of time, thereby preventing the growth of mold and bacteria in the small holes 3 and the open cell layer 8 which are water passages. In the method (3), the antibacterial agent can be easily contained only around the small holes 3, and the waste of the antibacterial agent can be eliminated.

  According to this manufacturing method, excellent mechanical strength is maintained by a simple operation of pressing the V-shaped or cone-shaped pressing blade 11 having a tip angle of 30 ° to 150 ° on the surface of the thermoplastic resin foam main body 2. As it is, it can easily absorb water adhering in the form of water droplets, and even if water remains in the small holes 3 or the open cell layer 8, the antibacterial agent can prevent the growth of mold and bacteria over a long period of time. The antibacterial / water-absorbent thermoplastic resin foam 1 described above that can prevent appearance deterioration due to generation or mold growth can be provided at low cost and with high production efficiency.

  The present invention is not limited to the above-described embodiments, and various modifications and changes can be made. For example, a non-foamed resin layer may be laminated on at least a part of the surface of the thermoplastic resin foam main body 2, and the small holes 3 may be provided thereon.

  The antibacterial / water-absorbing thermoplastic resin foam of the present invention can be used for bathroom components, foot-wiping mats, residential heat insulating materials, wallpaper, condensed water-absorbing tape, and the like.

[Manufacture of foam sheet]
As the extruder, a tandem type extruder in which an inner diameter 90 mm extruder (first stage extruder) and a 150 mm extruder (second stage extruder) are connected is used, and a polystyrene resin (trade name HRM-26, manufactured by Toyo Styrene Co., Ltd.) 100 is used. Extruded compounded raw material with 0.5 parts by mass of Biocide 300R (manufactured by Taisho Technos) as an antibacterial agent and 1.5 parts by mass of Talpet 40GS (manufactured by Sowa Chemical Co., Ltd.) as talc MB with respect to parts by mass The mixture was put into a machine, melted and kneaded at a maximum temperature of 230 ° C., and then 4.2 parts by mass of butane (iso / normal = 50/50) was added as a foaming gas. Thereafter, the resin was cooled to around 165 ° C. suitable for foaming having open cells.

Further, the resin is extruded and foamed from a circular die set to a diameter of 105 mm and a slit clearance of 0.5 mm attached to the tip, and this foamed sheet is passed through a cooling mandrel having an outer diameter of 414 mm and a length of 500 mm to simultaneously cool the inner surface. Air at a cooling temperature of 30 ° C. was blown to cool the outer periphery, and then the sheet was cut into two sheets and wound into a roll. The obtained foamed sheet had a thickness of 2.5 mm and a density of 0.09 g / m ² .

As a result of measuring the open cell rate of the obtained foamed sheet, the open cell rate was 70.1%.
The open cell ratio was measured according to the measurement method described in ASTM D2856-87. That is, five test specimens (25 mm cubes) composed of sections so as to be 25 mm or more were cut out from the sample, the apparent volume was measured using a caliper, and then an air comparison hydrometer 1000 (manufactured by Tokyo Science Co., Ltd.). ) And the volume was measured by the 1-1 / 2-1 atmospheric pressure method, and the open cell ratio was calculated by the following formula.
Open cell ratio (%) = (apparent volume−volume measured with an air-based hydrometer) / apparent volume × 100

[Example 1]
The foamed sheet produced as described above was passed through a punching jig shown in FIG. 12, and small holes were provided on the surface of the foamed sheet to produce an antibacterial / water-absorbent foamed sheet. This drilling jig is constructed by attaching a gear having a tip angle of 30 ° shown in FIG. 11 to a paper roll and passing a foam sheet between the drilling jig and the roller as shown in FIG. Opened. The bending length and the opening length of the small holes were measured by an electron micrograph of the surface of the formed small holes. Further, in order to measure the tilt angle at which the internal cell was broken, the cross section was cut in a direction in which the tilt angle was clearly understood, the cross-section of the small hole was taken with an electron micrograph, and the tilt angle with the sheet surface was measured. At that time, a small hole shape was also observed. The electron micrograph was measured with a scanning electron microscope S-3000N (manufactured by Hitachi, Ltd.) at an appropriate magnification. FIG. 15 shows the surface shape of the small holes. The shape of the small holes obtained was such that the distance B between the inclined surfaces was 0.55 mm, the lower end diameter D of the upper portion of the small holes was 0.30 mm, and the inclination angle θ was 50 °. The small hole upper width E was 0.75 mm. The small hole depth A was 1.5 mm. The lower end diameter D of the upper portion of the small hole / the distance B of the inclined surface was 0.55. 169 small holes were provided per 100 cm ² of the foam laminated sheet. The cross-sectional shape of the small hole was the shape shown in FIG.

(Evaluation of water absorption)
The obtained antibacterial / water-absorbent foam sheet was examined for water absorption.
After seeing the water droplets, it was visually confirmed whether or not one drop of water was dropped into one small hole for 5 mL of Komagome pipette. It was judged that there was water absorption when water droplets were dropped on 10 small holes and water was absorbed at 5 or more locations within 10 seconds.
In the antibacterial / water-absorbent foam sheet of Example 1, 10 out of 10 small holes absorbed water, and the water absorption was determined as ◯.

[Example 2]
Small holes were provided in the foamed sheet in the same manner as in Example 1 except that the tip angle of the gear attached to the drilling jig was set to 60 °, thereby producing an antibacterial / water absorbent foamed sheet.
The shape of the obtained small hole was such that the distance B of the inclined surface was 0.67 mm, the lower end diameter D of the upper part of the small hole was 0.35 mm, and the inclination angle θ was 45 °. The small hole upper width E was 0.75 mm. The small hole depth A was 1.5 mm. The lower end diameter D of the upper portion of the small hole / the distance B of the inclined surface was 0.52. The cross-sectional shape of the small hole was the shape shown in FIGS. 169 small holes were provided per 100 cm ² of the foam laminated sheet.
The obtained antibacterial / water-absorbent foam sheet was examined for water absorption in the same manner as in Example 1. As a result, 10 of the 10 small holes absorbed water, and the water absorption was determined as ◯.

[Example 3]
Except that the tip angle of the gear attached to the drilling jig was 90 °, small holes were provided in the foamed sheet in the same manner as in Example 1 to produce an antibacterial / water absorbent foamed sheet.
As for the shape of the obtained small hole, the distance B of the inclined surface was 0.90 mm, the lower end diameter D of the upper part of the small hole was 0.45 mm, and the inclination angle θ was 40 °. The small hole upper width E was 0.75 mm. The small hole depth A was 1.5 mm. The lower end diameter D of the upper portion of the small hole / the distance B of the inclined surface was 0.50. The shape of the small hole surface is shown in FIG. The cross-sectional shape of the small hole was the shape shown in FIG. 169 small holes were provided per 100 cm ² of the foam laminated sheet.
The obtained antibacterial / water-absorbent foam sheet was examined for water absorption in the same manner as in Example 1. As a result, 10 of the 10 small holes absorbed water, and the water absorption was determined as ◯.

[Example 4]
A polystyrene foam sheet (made by Oishi Sangyo Co., Ltd.) having a thickness of 25 μm is superposed on the polystyrene foam sheet produced as described above, passed through a dielectric heating roll having a heating temperature of 170 ° C. and a diameter of 300 mm, and then the tip angle of the pressing blade is 60 °. An antibacterial / water-absorbent foam sheet was prepared by drilling using a drilling jig equipped with a gear and providing a large number of small holes. The obtained small hole had a distance B of the inclined surface of 0.67 mm, a lower end diameter D of the upper part of the small hole of 0.38 mm, and an inclination angle θ of 55 °. The small hole upper width E was 0.75 mm. The small hole depth A was 1.5 mm. The lower end diameter D of the upper portion of the small hole / the distance B of the inclined surface was 0.57. 169 small holes were provided per 100 cm ² of the foam laminated sheet. The cross-sectional shape of the small hole was the shape shown in FIGS.
The obtained antibacterial / water-absorbent foam sheet was examined for water absorption in the same manner as in Example 1. As a result, 10 of the 10 small holes absorbed water, and the water absorption was determined as ◯.

[Example 5]
As the extruder, a tandem type extruder in which an inner diameter 90 mm extruder (first stage extruder) and a 150 mm extruder (second stage extruder) are connected is used, and a polystyrene resin (trade name HRM-26, manufactured by Toyo Styrene Co., Ltd.) 100 is used. Extruded compounded raw material with 0.5 parts by mass of Biocide 300R (manufactured by Taisho Technos) as an antibacterial agent and 1.5 parts by mass of Talpet 40GS (manufactured by Sowa Chemical Co., Ltd.) as talc MB with respect to parts by mass The mixture was put into a machine, melted and kneaded at a maximum temperature of 230 ° C., and then 4.2 parts by mass of butane (iso / normal = 50/50) was added as a foaming gas. Thereafter, the resin was cooled to around 165 ° C. suitable for foaming having open cells.
On the other hand, using a 120 mm inner diameter extruder (B), Talpet 40GS (Sowa Chemical Co., Ltd.), which is talc MB, was added to 100 parts by mass of polystyrene resin (trade name G-13-50B, manufactured by Toyo Styrene Co., Ltd.). The compounded raw material added with 5 parts was put into an extruder, melted and kneaded at a maximum temperature of 230 ° C., and then 3.7 parts by mass of butane (iso / normal = 50/50) was added as a foaming gas. Thereafter, the resin was cooled to around 155 ° C. suitable for foaming having closed cells.
The extruder (A) and the extruder (B) are joined together by a joining die and laminated. Further, the resin is extruded from a circular die set to a diameter of 105 mm and a slit clearance of 0.5 mm attached to the tip, and foamed. The foamed sheet was passed through a cooling mandrel having an outer diameter of 440 mm and a length of 500 mm to cool the inner surface, and at the same time, air at a cooling temperature of 30 ° C. was blown to cool the outer periphery, and then the sheet was cut into two sheets and wound into a roll. The obtained foamed laminated sheet had a thickness of 2.8 mm and a density of 0.075 g / m ² .
The foam layer on the extruder (A) side was an open cell layer having an open cell rate of 68.5%.
The foam layer on the extruder (B) side was a closed cell layer having an open cell ratio of 10.5%.

The obtained foamed laminated sheet was punched using a drilling jig with a gear having a tip blade angle of 60 °, and a large number of small holes were provided to produce an antibacterial / water-absorbent foam sheet. The obtained small hole had a distance B of the inclined surface of 0.67 mm, a lower end diameter D of the upper part of the small hole of 0.35 mm, and an inclination angle θ of 45 °. The small hole upper width E was 0.75 mm. The small hole depth A was 1.8 mm. The lower end diameter D of the upper portion of the small hole / the distance B of the inclined surface was 0.52. 169 small holes were provided per 100 cm ² of the foam laminated sheet. The cross-sectional shape of the small hole was the shape shown in FIGS. FIG. 1 shows the cross-sectional shape of the small hole.
The obtained antibacterial / water-absorbent foam sheet was examined for water absorption in the same manner as in Example 1. As a result, 10 of the 10 small holes absorbed water, and the water absorption was determined as ◯.

[Example 6]
Except not adding a bactericidal agent, the foaming lamination sheet which laminated | stacked the open cell layer and the closed cell layer which do not contain an antibacterial agent on the conditions similar to manufacture of the foaming sheet in Example 5 was manufactured.
In the same way as in Example 5, the obtained foamed laminated sheet was subjected to drilling using a drilling jig equipped with a gear having a tip angle of 60 °, and a large number of small holes were provided to produce a water absorbent foamed sheet. did. 169 small holes were provided per 100 cm ² of the foam laminated sheet.
Next, as an antibacterial agent, a halo coat (manufactured by Get Co., Ltd.) was spray-applied on the surface of the water absorbing sheet on the small pore side (open cell layer side) at a rate of 0.5 g / 100 cm ² . Thereafter, the sheet was dried to prepare an antibacterial / water-absorbent foam sheet.

[Comparative Example 1]
A needle having a diameter of 1 mm was pressed on the foamed sheet produced in Example 5 to provide a small hole, thereby producing an antibacterial / water-absorbent foamed sheet. The obtained small hole had no inclined surface (B = 0 mm) in the opening portion, the hole-opening portion was a circle having a diameter of 0.65 mm, and the inclination angle θ was 90 °. The small hole depth A was 1.5 mm. 169 small holes were provided per 100 cm ² of the foam laminated sheet. The cross-sectional shape of this small hole is shown in FIG.
The obtained antibacterial / water-absorbent foam sheet was examined for water absorption in the same manner as in Example 1. As a result, only 3 of the 10 small holes absorbed water, and the water absorption was determined as x.

[Comparative Example 2]
The same foamed laminated sheet as used in Example 6 in which an open cell layer containing no antibacterial agent and a closed cell layer is used, and as in Example 5, the tip angle of the pressing blade is 60 °. Drilling was performed using a drilling jig equipped with a gear to provide a large number of small holes, and a water-absorbent foam sheet containing no antibacterial agent was produced. 169 small holes were provided per 100 cm ² of the foam laminated sheet.

<Antimicrobial test>
About each sheet | seat of Examples 1-6 and Comparative Examples 1 and 2, antibacterial power was investigated.
Procured kitchen corners and bathroom foot mats from multiple households. Select several items that are soiled by mold, cut them into small pieces, put them in physiological saline, and magnetically. The mixture was stirred for 3 hours using a stirrer to obtain contaminated water for antibacterial testing.
Each sheet of Examples 1 to 6 and Comparative Examples 1 and 2 is cut into a 5 cm × 5 cm square, placed in a petri dish, poured with 5 mL of the contaminated water for antibacterial test, the petri dish lid is closed, and placed in a thermostatic bath at 25 ° C. Cultured for 1 week.
As a result, generation | occurrence | production of mold | fungi etc. was not recognized in each sheet | seat (antibacterial and water absorbing foam sheet) of Examples 1-6 and Comparative Example 1 in which the antibacterial agent was contained. On the other hand, the sheet of Comparative Example 2 containing no antibacterial agent (water-absorbent foam sheet containing no antibacterial agent) was confirmed to have a large number of stains on which mold had propagated.

It is a figure which shows the microscope observation image of the cross section of the small hole part of the antibacterial and water absorbing thermoplastic resin foam produced in Example 5 which concerns on this invention. BRIEF DESCRIPTION OF THE DRAWINGS The small hole of the antibacterial and water absorbing thermoplastic resin foam concerning this invention is represented schematically, (a) is sectional drawing, (b) is a top view. The 2nd example of the shape of a small hole is shown, (a) is sectional drawing, (b) is a top view. The 3rd example of the shape of a small hole is shown, (a) is sectional drawing, (b) is a top view. It is sectional drawing which shows the 4th example of the shape of a small hole. It is sectional drawing which shows the 5th example of the shape of a small hole. It is sectional drawing which shows the 6th example of the shape of a small hole. It is sectional drawing which shows the 7th example of the shape of a small hole. It is sectional drawing which shows the 8th example of the shape of a small hole. It is a figure explaining the manufacturing method which concerns on this invention, and is sectional drawing which shows the state which pressed the press blade against the thermoplastic resin foam main body. It is a figure which shows the gearwheel used for drilling, (a) is a side view of the 1st example of a gearwheel, (b) is a front view, (c) is a side view of the 2nd example of a gearwheel, (d) is a front view. It is. It is an external view which illustrates a drilling jig. It is a perspective view explaining the manufacturing method which concerns on this invention. It is sectional drawing explaining the process in which the small hole of the shape of FIG. 1 is formed after the press blade is pressed. It is a figure which shows the microscope observation image of the surface of the small hole part of the antibacterial and water absorbing thermoplastic resin foam produced in Example 1 which concerns on this invention. It is a figure which shows the microscope observation image of the surface of the small hole part of the antibacterial and water absorbing thermoplastic resin foam produced in Example 3 which concerns on this invention. It is a figure which shows the microscope observation image of the cross section of the small hole part of the antibacterial and water absorbing thermoplastic resin foam produced by the comparative example 1. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Antibacterial / water-absorbing thermoplastic resin foam, 2 ... Thermoplastic resin foam main body, 3 ... Small hole, 4 ... Small hole upper part, 5 ... Small hole lower part, 5a ... Hollow part, 6 ... Inclined surface, 7 ... Surface skin layer, 8 ... open cell layer, 9 ... closed cell layer, 10 ... twisted part, 11 ... pressing blade, 12A, 12B ... gear, 13 ... drilling jig, 14 ... roller, 15 ... foam laminated sheet, 16 ... Antibacterial / water-absorbent foam sheet (antibacterial / water-absorbent thermoplastic resin foam).

Claims (17)

An antibacterial / water-absorbing thermoplastic resin foam having a large number of small holes leading from at least a part of the surface of the thermoplastic resin foam body to the inside, and containing an antibacterial agent at least around the small holes, The small hole has at least a small hole upper part and a small hole lower part having different inclination angles, the small hole upper part has an inclined shape whose diameter is expanded toward the surface, and the thermoplastic resin foam main body is made of polystyrene. antibacterial water absorbing thermoplastic resin foam which is a system resin foam.   The antibacterial / water-absorbent thermoplastic resin foam according to claim 1, wherein the small hole lower portion has a bottom.   The antibacterial / water-absorbing thermoplastic resin foam according to claim 1, further comprising a crease between the small hole upper part and the small hole lower part.   The antibacterial / water-absorbing thermoplastic resin foam according to any one of claims 1 to 3, wherein an inclination angle formed by an inclined surface of the upper portion of the small hole with respect to the surface is in a range of 20 ° to 70 °. body.   The antibacterial / water-absorbing thermoplastic resin foam according to any one of claims 1 to 4, wherein the lower end diameter of the small hole upper portion / the distance of the inclined surface of the small hole upper portion is in the range of 0.2 to 1. body.   The antimicrobial / water-absorbing thermoplastic resin foam according to any one of claims 1 to 5, wherein an open cell ratio of the thermoplastic resin foam main body is 50 to 80%.   The antibacterial / water-absorbing thermoplastic resin foam according to claim 1, wherein a thermoplastic resin foam having an open cell ratio of 30% or less is laminated on the thermoplastic resin foam main body. body.   The antibacterial / water-absorbing device according to any one of claims 1 to 7, wherein a non-foamed resin layer is laminated on at least a part of the surface of the thermoplastic resin foam main body, and the small holes are provided in the non-foamed resin layer. Thermoplastic foam. Wherein the antimicrobial agent is a silver-based antimicrobial agent, copper-based antibacterial agents, antibacterial water absorbing thermoplastic according to any one of claims 1 to 8, characterized in that any one of iodine antimicrobials Resin foam. A V-shaped or cone-shaped pressing blade having a tip angle of 30 ° to 150 ° is provided on at least a part of the surface of a thermoplastic resin foam body obtained by foaming a thermoplastic resin containing an antibacterial agent and a foaming agent. pressed, the inclination angle has at least a different small hole portion and small hole bottom, the small hole top provided a large number of small holes having an inclined shape which is enlarged towards the surface, any of claim 1-9 A method for producing an antibacterial / water-absorbing thermoplastic resin foam, comprising obtaining the antibacterial / water-absorbing thermoplastic resin foam according to claim 1. At least a part of the surface of the thermoplastic resin foam body is pressed with a V-shaped or cone-shaped pressing blade having a tip angle of 30 ° to 150 ° to have at least a small hole upper portion and a small hole lower portion having different inclination angles. and, said small hole top provided a large number of small holes having an inclined shape which is enlarged toward the surface, allowed thereafter to absorb the liquid containing the antimicrobial agent from the stoma, by drying, any claim 1-9 A method for producing an antibacterial / water-absorbing thermoplastic resin foam, comprising obtaining the antibacterial / water-absorbing thermoplastic resin foam according to claim 1. A small V-shaped or cone-shaped pressing blade having a tip angle of 30 ° to 150 ° with a liquid containing an antibacterial agent adhered to at least a part of the surface of the thermoplastic resin foam main body and having a different inclination angle. 10. The antibacterial / water-absorbing property according to any one of claims 1 to 9 , comprising at least a hole upper part and a small hole lower part, wherein the small hole upper part is provided with a large number of small holes having an inclined shape expanded toward the surface. A method for producing an antibacterial and water-absorbing thermoplastic resin foam, characterized by obtaining a thermoplastic resin foam. The antibacterial / water-absorbing thermoplastic resin foam according to any one of claims 1 to 9, wherein the foamed antibacterial / water-absorbing thermoplastic resin is a sheet. An antibacterial / water-absorbing thermoplastic resin foam sheet formed by molding the antibacterial / water-absorbing thermoplastic resin foam sheet according to claim 13 .   The antibacterial / water-absorbing thermoplastic resin foam board according to any one of claims 1 to 9, wherein the foamed antibacterial / water-absorbing thermoplastic resin foam board is a thick plate. A bathroom component comprising the antibacterial / water-absorbent thermoplastic resin foam according to any one of claims 1 to 9 . A foot-wiping mat comprising the antibacterial / water-absorbing thermoplastic resin foam according to any one of claims 1 to 9 .

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