JP2018135440A - Antibacterial synthetic resin pellet, antibacterial synthetic resin molded product using the same, and method for producing antibacterial synthetic resin pellet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a synthetic resin pellet which is suitable for molding an inexpensive antibacterial synthetic resin product and carries metal nanoparticles, and to provide an antibacterial synthetic resin molded product using the synthetic resin pellet as a raw material and a method for producing the synthetic resin pellet.SOLUTION: There are provided a metal nanoparticle-carrying synthetic resin pellet in which 0.005-0.5 wt.% of at least one metal nanoparticles selected from Au, Pt, Ag, Zn, Cu, nickel (Ni), cobalt (Co) and Al that have average particle diameter of 1-50 nm and alloys containing at least two or more metals of the metals is deposited on the spherical or columnar synthetic resin pellet; and a method for depositing a vapor-deposited substance obtained by thermal decomposition of a vapor-deposited source on the synthetic resin pellet under the atmosphere of 130°C or lower using any physical vapor deposition method selected from a vapor deposition method, an ion plating method and a sputtering method.SELECTED DRAWING: None

Description

  The present invention relates to an antibacterial synthetic resin pellet which is a suitable raw material for an antibacterial synthetic resin molded product having antibacterial properties, antiviral properties, antifungal properties, and the like, and an antibacterial synthetic resin molded product manufactured using the pellet And an antibacterial synthetic resin pellet manufacturing method.

In developed countries, when people's material needs are satisfied, a clean and healthy living environment, that is, a living environment free from invisible odors, molds, fungi, etc., is required, and the 1900s Upon entering, we have come to have a lot of antibacterial processed products with antibacterial processing, such as household / kitchen utensils, food containers / wrapping materials, clothing, stationery / toys, electrical / electronic products, housing / building materials, etc. (Non-Patent Document 1). Moreover, electrolyzed water and disinfectant having antibacterial and antiviral properties are recognized not only at public facilities such as hospitals and schools, but also at entrances and exits of general offices (Patent Document 1).

  In particular, food is indispensable for human daily life, and ensuring food safety is a very important issue. However, mass food poisoning such as enterohaemorrhagic Escherichia coli such as Norovirus, Salmonella and O157 is reported in the summer (bacteria) and winter (virus). Expectations are rising.

  On the other hand, in developed countries rich in materiality, food is distributed excessively and surplus. In the case of food with a shelf life and expiration date, it cannot be reused like durable consumer goods such as home appliances / furnitures and automobiles, and semi-durable consumer goods such as clothing and bags. About 1.3 billion tons of food, which is a fraction, is discarded, and about 17 million tons of food waste is discharged annually in Japan. This is based on a number of different factors for food producers, food manufacturers, retail stores, restaurants, and homes, but food that has expired at retail stores is discarded without modification. There are many. In particular, foods with a short shelf life, such as lunch boxes and salads, are discarded as they are left unsold, and a large amount of food loss that can be eaten is discharged every day. It can be greatly reduced. Therefore, also from this point of view, there is an increasing expectation for an “antibacterial processed product” that protects food from molds, fungi, and the like (Non-patent Document 2).

  By the way, in modern life, various synthetic resin products put into practical use since the 1950s are excellent in molding processability, lightweight and inexpensive, and excellent in physical, chemical and electrical properties. Replaced by products, ceramic products, glass products, paper products, woodwork products, etc., it has become widely established. Therefore, there are many antibacterial processed products in which a synthetic resin product is filled or coated with an antibacterial agent, and technical development relating to the antibacterial agent suitable for the synthetic resin product and its immobilization is active.

  Such antibacterial agents can generally be broadly classified into organic and inorganic (Non-patent Document 1). As organic antibacterial agents, quaternary ammonium salts, quaternary phosphonium salts, pyridines, pyrithiones, benzimidazoles, satisfying the conditions of thermal stability and low toxicity suitable for molding of synthetic resins , Organic iodine type, isothiazoline type and the like. On the other hand, as an inorganic antibacterial agent, many metal ions such as silver, copper, and zinc are supported on an inorganic carrier by an ion exchange method. Depending on the inorganic carrier, phosphate, silicate, thiosulfide are used. It is classified as a complex salt system. Excellent physical and chemical stability, such as thermal stability and chemical resistance, and can be used as an additive for synthetic resins, so silver ions can be used in silicate, zirconium phosphate, calcium phosphate, potassium titanate, etc. Many antibacterial agents carried on various inorganic compounds are commercially available (Patent Document 2). In addition, organic complexes of the metal ions are also classified as inorganic antibacterial agents.

  However, an organic antibacterial agent is not necessarily preferable from the viewpoint of safety to the human body, but also has a low molecular weight and cannot chemically react with the surface of the synthetic resin. Even if it is dispersed inside or coated on the surface of the synthetic resin, it tends to be detached from the surface of the synthetic resin and long-term antibacterial action cannot be expected (Patent Document 3).

  Synthetic resin products are molded from a copolymer of a monomer containing an antibacterial function, for example, a quaternary ammonium salt-containing monomer and other monomers, for the problem of such organic antibacterial agents. Processing has been proposed (Patent Document 4). In addition, an antibacterial agent containing a quaternary ammonium salt and an alkoxy group has been developed, and a method of immobilizing by surface reaction of a hydroxyl group on the surface of a synthetic resin product and an alkoxy group of the antibacterial agent has been proposed (patent) Reference 5).

  On the other hand, inorganic antibacterial agents that are excellent in physical and chemical stability and can be used as additives for synthetic resins also have a problem that it is difficult to balance the addition amount and antibacterial performance. For example, in the case of synthetic resin molded products such as films that require transparency, the amount of addition that can exhibit antibacterial performance impairs transparency, and the amount of addition that maintains transparency does not exhibit antibacterial performance (Patent Document 3).

  In recent years, platinum (Pt), gold (Au), and the effects of antioxidation, antibacterial, sterilization, mold prevention, freshness maintenance, deodorization and the like have been attracting attention for the problems of such inorganic antibacterial agents, Application of noble metal nanoparticles such as silver (Ag) to synthetic resin products is being studied. This is because all of Pt, Au, and Ag are highly safe materials that are approved as existing food additives by the Food Sanitation Law, and can produce nanoparticles with extremely large surface areas. This is because it has become. For example, antibacterial linens for medical use that have excellent washing durability by immobilizing Pt nanoparticles produced using hydroxycarboxylic acid as a stabilizer on the fiber surface by a liquid phase reduction method, which is a general method for producing nanoparticles, and accommodation facilities Antibacterial linens for use, daily antibacterial clothing, and the like are disclosed (Patent Document 6). In addition, in order to form an antibacterial coating film that requires transparency, a paint in which precious metal ultrafine particles modified with a fatty acid, which is also a stabilizer produced by the liquid phase reduction method, is dispersed in a photocurable resin. (Patent Document 8). Conversely, in the case of an antibacterial synthetic resin molded product that requires a dark color, the conventional inorganic antibacterial agent is white and difficult to apply, but it is 0.01 to 0 for inorganic particles or resin particles having a particle size of 50 μm or less. It is disclosed that it can be solved by mixing injection molding by mixing a black pigment in which 5 μm Ag alloy particles or nickel (Ni) alloy particles are deposited by a physical vapor deposition (PVD) method with a synthetic resin (Patent Document 7). .

  However, the problem of antibacterial synthetic resin products using noble metal nanoparticles is to find a method for producing nanoparticles that do not contain impurities such as dispersants, have a small particle size, and a narrow distribution. In addition, noble metals are extremely expensive and are difficult to apply to general consumables.

  First, wet methods such as the liquid phase reduction method, which has been often used as a method for producing noble metal nanoparticles, require a stabilizer (dispersant) for making the noble metal nanoparticles into a stable dispersion. Therefore, the surface of the noble metal nanoparticles is coated (Patent Document 9). In addition, since the wet method undergoes processes such as nucleation, growth, and termination, it is difficult to control the particle size, it is difficult to uniformly produce fine nanoparticles of several nanometers or less, and metal nanoparticles having a large particle size. Presence of noble metal nanoparticles decreases the surface area (Patent Document 10). All of these cause the effects of anti-oxidation, anti-virus, antibacterial, antibacterial, antifungal, freshness maintenance, deodorization and the like possessed by the noble metal nanoparticles and the original properties of the resin. In addition, such a liquid phase method is suitable as a stabilizer for a water-soluble substance, and is often produced in an aqueous solution (Patent Document 10), and has been studied in a device bonding technique or the like (Non-Patent Document 3). ), When antibacterial action is intended, it is not preferable as a method for producing metal nanoparticles that are easily oxidized. Therefore, although it does not reach the antibacterial action of precious metals, it is not possible to apply inexpensive zinc (Zn), copper (Cu), aluminum (Al), etc., especially Cu, which is approved as an existing additive, to the liquid phase method. It is thought that it is not preferable (nonpatent literature 4). And the wet method cannot form metal nanoparticles on the inorganic particles and resin particles which are the raw materials of the synthetic resin molded product.

  As methods for producing metal nanoparticles that do not require a dispersant, there are gas phase methods such as the PVD method, chemical vapor deposition (CVD) method, gas phase synthesis method, and evaporation / aggregation method described above. However, in the CVD method, reactive monomers activated by plasma or the like chemically react in a heating furnace to form nanoparticles through nucleation, condensation, and aggregation, but the production efficiency and energy efficiency are poor. For this reason, there is a problem that the manufacturing cost is high and the particle size becomes non-uniform due to the process of nucleation, condensation, and aggregation. The vapor phase synthesis method is a method of generating nanoparticles by oxidation, reduction, and nitridation in a metal chloride reaction gas, but has a problem that impurities based on the raw materials are intensively mixed. The evaporation / aggregation method is a method in which a metal is once evaporated in an inert gas by a method such as laser ablation, sputtering, or vacuum deposition, and then cooled to produce nanoparticles. There's a problem.

  Furthermore, methods for producing nanoparticles that do not require a dispersant using plasma-induced cathodic electrolysis or liquid phase laser ablation of molten salts have been developed. In addition, a large number of improvements are required, and nanoparticles cannot be formed on inorganic particles or resin particles as raw materials for synthetic resin molded products (Patent Documents 11 to 14).

  Therefore, the PVD method in which vapors such as metals and metal oxides released by vacuum evaporation or sputtering are deposited as nanoparticles on a substrate or carrier is expected as a method for producing metal nanoparticles that do not require a dispersant. Yes. In this method, as described above, nanoparticles that do not contain impurities can be produced on inorganic particles and resin particles, and can be used as raw materials for synthetic resin molded products as they are. Therefore, antibacterial / sterilization is required. Use in various fields such as exhaust gas and wastewater treatment catalysts, solar battery and other electronic parts is being studied (Patent Documents 15 to 17).

  However, even in the case of the PVD method, the film formation process is controlled by the vacuum evaporation method or the sputtering method, that is, the method of generating metal nanoparticles by stopping the growth with island-shaped metal particles formed at the initial stage of film formation. Therefore, there is a problem that it is difficult to produce uniform nanoparticles (Non-Patent Document 5 and Patent Document 16). As described above, the non-uniformity of the nanoparticles having such a wide particle size distribution has the anti-oxidation, anti-virus, anti-bacterial, sterilization, anti-mold, freshness maintenance, anti-odor, and the original properties of the resin. Not only will it cause a decrease, but it will also cause problems in the production of synthetic resin products. In particular, in compression molding, calendar molding, injection molding, hollow molding, extrusion molding, and the like, if particles having a large particle diameter are included, there is a problem that the surface smoothness of the molded product is poor. Furthermore, in the case of producing a film, in most cases, a melt film-forming method, that is, a drawing method in which a sheet extruded from a T die is heated and stretched to form a film, or a sheet extruded from a ring die is expanded with air. Since the film is produced by the inflation method, not only the surface smoothness but also a problem that the film is unable to be produced due to the opening of the holes starting from the particles. In addition, the non-uniformity of the particles also impairs the transparency of the film.

  As described above, since no raw materials for antibacterial synthetic resin products that can satisfy the quality, moldability, and cost of antibacterial synthetic resin products have been found, naturally, synthesis that achieves both quality and cost is achieved. At present, resin products have not yet been obtained.

Japanese Patent No. 4712915 JP 2000-001621 A JP-A-10-245305 JP 2001-055518 A JP 2007-126557 A JP 2008-056592 A Japanese Patent Laid-Open No. 11-181327 JP2015-120896A Japanese Patent Application Laid-Open No. 2015-0675556 JP 2005-139102 A JP 2008-106309 A JP 2010-077458 A JP 2009-511754 A International Publication WO2012-150804 JP 2009-146025 A JP 2009-246025 A

Shinichiro Hatakeyama, “Antimicrobial processing of plastic products”, Journal of Textile Products Consumer Science, Vol. 40, no. 9, pp. 576-584 (1999). Ministry of Agriculture, Forestry and Fisheries (Food Industry Bureau, Biomass Environment and Resources Division, Food Industry Environment Countermeasures Office) ~ ", September 2013. Shohei Shiomi, Tomoki Maruoka, Yasumasa Kikuuchi, “Preparation of Cu Nanoparticles and Application to Device Bonding Technology—Establishment of Particle Size Control Technology for Cu Nanoparticles”, Kyoto City Industrial Technology Research Institute, Research Report, No. 4, pp. 28-33 (2014). Noriyuki Yamamoto, Shinji Sugiura, “Features and Applications of Silver-Based Inorganic Antibacterial Agent“ NOVALON ”, Toa Gosei Research Annual Report, TREND 1998, first issue, pp. 28-33. Tagung Yasunori, “Research on Thin Film Process Technology”, Integrated Engineering, Vol. 22 (2010) pp. 53-64.

  The present invention provides a synthetic resin pellet supporting metal nanoparticles, which is suitable for molding an inexpensive antibacterial synthetic resin product, and an antibacterial synthetic resin molded product using the synthetic resin pellet as a raw material, and It aims at providing the manufacturing method of this synthetic resin pellet.

  In other words, the present invention is a problem of the wet method and the PVD method that have been widely used conventionally, that is, a dispersant and impurities contained in metal nanoparticles, a wide particle size distribution, difficult to form on synthetic resin particles, and The object of the present invention is to provide a technique for solving various problems such as unsuitability for a metal that is easily oxidized and for solving problems such as surface roughness and pinholes that occur in the molding process of synthetic resin.

  The present invention provides a spherical or cylindrical synthetic resin pellet having an average particle size of 1 to 50 nm, Au, Pt, Ag, Zn, Cu, nickel (Ni), cobalt (Co), Al, and these Metal nanoparticles characterized in that at least one metal nanoparticle selected from an alloy containing at least two kinds of metals is deposited in an amount of 0.005 to 0.5% by weight with respect to the synthetic resin pellets. A particle-supporting synthetic resin pellet is provided.

  In particular, the metal nanoparticle-supported synthetic resin pellet of the present invention uses any one of the vapor deposition method, the ion plating method, and the sputtering method, and the vapor deposition material obtained by thermal decomposition of the metal deposition source is as follows. On the synthetic resin pellets to be vapor-deposited, the vapor deposition material is synthetic resin so that the vapor deposition time during which the vapor deposition material continuously deposits on the synthetic resin pellets in an atmosphere of 130 ° C. or less is at least 0.2 sec or less. It is preferable that the metal nanoparticles are intermittently deposited on the pellet and the metal nanoparticles are deposited in an average particle diameter of 1 to 50 nm and 0.005 to 0.5% by weight with respect to the synthetic resin pellet. .

  Furthermore, the average particle diameter of the metal nanoparticles is more preferably 1 to 10 nm, and still more preferably 1 to 5 nm. The metal constituting the nanoparticles is most preferably Cu in terms of performance and price.

  On the other hand, synthetic resin pellets include compression molding, calendar molding, extrusion molding, injection molding, hollow molding, inflation molding, stretch molding, T-die molding, tableware, storage containers, housings, bottles, sheets, pipes, films, etc. The thermoplastic resin is preferably a thermoplastic resin that can be easily applied to a processing method capable of molding various synthetic resin products.

  Among such thermoplastic resins, vinyl resins, acrylic resins, ABS resins, polyester resins, polyamide resins, polyether resins, polysulfone resins, polyacetal resins, polysulfide resins, and fluororesins At least one synthetic resin selected from the group consisting of polyethylene (PE) resin, polypropylene (PP) resin, polystyrene (PS) resin, polymethyl methacrylate (PMMA) resin, ABS resin, polyethylene More preferably, it is at least one synthetic resin pellet selected from terephthalate (PET) resin and nylon (NY) resin, and a polyethylene (PE) resin and polypropylene (PP) resin that can form a thin film. , Polyethylene terephthalate Preparative (PET) resins, and, more preferably more is at least one synthetic resin pellets selected from nylon (NY) based resin.

  As mentioned above, by using synthetic resin pellets carrying metal nanoparticles in the range of particle diameters having an average particle size of 1-50 nm, more preferably 1-10 nm, and even more preferably 1-5 nm, It becomes possible to produce synthetic resin molded products having excellent qualities such as antibacterial properties and surface smoothness. As for antibacterial properties and surface smoothness, metal nanoparticles having a large surface area and a small particle diameter are more preferable. Particularly, when forming a film, there is no pinhole, and the resin is thinner and excellent in transparency. A film can be stably produced without deteriorating the original characteristics.

  As a molding method for producing a synthetic resin product, compression molding, calendar molding, extrusion molding, injection molding, hollow molding, inflation molding, stretch molding, and T-die molding are preferable. According to the present invention, the average particle diameter is 1 to 50 nm. , More preferably 1 to 10 nm, still more preferably 1 to 5 nm, using as a raw material a synthetic resin pellet carrying metal nanoparticles in a particle size range, a compression molded product, a calendar molded product, an extrusion molded product, An injection molded product, a hollow molded product, an inflation film, a stretched film, and a T-die molded film can be provided. Among them, the synthetic resin pellets carrying the metal nanoparticles of the present invention have the characteristics as described above in the production of films using PE resin, PP resin, PET resin, and NY resin. It is demonstrated to the fullest.

  The present invention is also a method for producing metal nanoparticle-supported synthetic resin pellets, wherein any one of a physical vapor deposition method, a vapor deposition method, an ion plating method, and a sputtering method is used to heat the vapor deposition source that is a metal. The vapor deposition time for the vapor deposition material to continuously deposit on the synthetic resin pellets in an atmosphere of 130 ° C. or lower on the synthetic resin pellets to be deposited should be at least 0.2 sec or shorter. The vapor deposition material is intermittently deposited on the synthetic resin pellet.

  By this production method, Au, Pt, Ag, Zn, Cu, Ni, Co, Al, and at least one kind of metal nanoparticles selected from an alloy containing at least two kinds of these metals, Spherical or cylindrical synthetic resin pellets having an average particle diameter of 50 nm, more preferably 1 to 10 nm, and still more preferably 1 to 5 nm, in a proportion of 0.005 to 0.5% by weight with respect to the synthetic resin It is supported stably in the shape.

  The particle size distribution of the metal nanoparticles using the PVD method is such that the deposition material is intermittently deposited on the synthetic resin pellet so that the deposition time during which the deposition material is continuously deposited on the synthetic resin pellet is at least 0.2 sec. In addition to being deposited on the substrate, it is achieved by suppressing the atmosphere during vapor deposition to 130 ° C. or lower. In particular, it is remarkable in the thermoplastic resins generally used such as PE resin, PP resin, PS resin, PMMA resin, ABS resin and the like having a low melting point. The cause of this is not clear, but in the film formation process by the vacuum evaporation method or sputtering method of the present invention, that is, in the method of generating metal nanoparticles by stopping the growth with island-shaped metal particles formed in the initial stage of film formation. This is probably because there is a close relationship between the surface state of the interaction between the deposition material and the deposition target and the generation of uniform nanoparticles. First, this is due to the PVD method (Non-Patent Document 5 and Patent Document 16). Such metal nanoparticles are produced by depositing and gathering the vapor deposition material that has come from the evaporation source onto the deposition target on the deposition target, as represented by the Volmer-Weber style. However, it is important not to reach the subsequent film formation, and it is considered necessary to be different from the normal PVD method in which a denser and better adhesive film is formed at a higher substrate temperature. . That is, it is presumed that a preferable result was obtained as the temperature of the atmosphere for vapor deposition was lowered. Second, this is because the vapor-deposited body is a thermoplastic resin. Its melting point is approximately 80 to 180 ° C. for a general-purpose crystalline resin such as PE or PP, or an amorphous resin such as PS or PMMA, and is a PET or NY engineering plastic. Although it is ˜280 ° C., these glass transition temperatures (Tg, the temperature at which the relative position of the polymer molecule does not change, but the rotation and vibration of the molecule start) are usually 100 ° C. or less, Ultimately, it is −100 ° C. or lower. Therefore, the interaction between the vapor deposition material and the vapor deposition material that has come from the evaporation source to the vapor deposition body varies depending on the temperature, affects the diffusion and aggregation of the vapor deposition material on the vapor deposition material, and the lower the temperature, the metal nanoparticles. Is presumed to be easily generated.

  Au, Pt, Ag, Zn, Cu, Ni, Co, Al, and these metals having an average particle diameter of 1 to 50 nm, more preferably 1 to 10 nm, and still more preferably 1 to 5 nm of the present invention Synthetic resin pellets in which at least one kind of metal nanoparticles selected from an alloy containing at least two kinds is supported at a ratio of 0.005 to 0.5% by weight with respect to the synthetic resin are left as they are. Because it can be used as a raw material for molding products, tableware and storage using molding methods such as compression molding, calender molding, extrusion molding, injection molding, hollow molding, inflation molding, stretch molding, T-die molding, etc. The present invention can be applied to the production of all antibacterial synthetic resin products such as containers, casings, bottles, sheets, pipes and films.

  In particular, food packaging materials and containers can be provided with antibacterial, antiviral, antifungal and the like required for hygiene management such as cleaning, disinfection, and deodorization and for maintaining the freshness of fresh food. Furthermore, in the agricultural field, it has a sterilizing and sterilizing effect on soil and fruit trees, is excellent in transparency, and can be used as a film or sheet to which mold or the like does not adhere.

  Since the antibacterial effect of the molded article of the metal nanoparticle-supported synthetic resin pellet is fixed in the synthetic resin, a long-term antibacterial effect can be expected as compared with the organic antibacterial agent. More interestingly, in the evaluation of the antibacterial effect of a molded article from an inorganic antibacterial agent and a synthetic resin pellet in which a conventional noble metal ion is supported on an inorganic carrier by an ion exchange method, the precious metals Au, Pt, and Ag ions are evaluated. In the molded product from the metal nanoparticle-supported synthetic resin pellet of the present invention, even with inexpensive Cu particles, an effect equivalent to or better than that of Au, Pt, and Ag particles can be obtained. I understood. The cause of this is not clear, but it is presumed that it is caused by the difference between whether it is supported on an inorganic carrier as ions or exists as metal nanoparticles having an extremely large surface area. Therefore, it has been conventionally necessary to use an expensive noble metal, but an extremely important effect has been found that it has become possible to use inexpensive Cu nanoparticles.

It is the schematic of the process of manufacturing an antimicrobial packaging material using the LDPE or PP pellet in which Cu nanoparticle of this invention was carry | supported. It is a conceptual diagram of the physical vapor deposition apparatus which manufactures the LDPE or PP pellet by which Cu nanoparticle of this invention was carry | supported. It is an electron micrograph of Cu nanoparticle carry | supported on the LDPE pellet of this invention. It is a conceptual diagram of inflation molding. An apple was stored in an antibacterial packaging material (b) in which an inflation film produced using a commercially available LDPE zippered packaging material (a) and Cu nanoparticle-supporting LDPE pellets was processed at 25 ° C. for 10 days. It is a photograph showing the state. After storing the cooked rice at 25 ° C. for 10 days in the antibacterial packaging material (b) obtained by bag-making the blown film produced using the commercially available LDPE chucked packaging material (a) and Cu nanoparticle-supported LDPE pellets It is a photograph showing the state. After storing cotton tofu for 10 days at 25 ° C. with an antibacterial packaging material (b) obtained by bag-processing an inflation film produced using a commercially available LDPE zippered packaging material (a) and Cu nanoparticle-supported LDPE pellets It is a photograph which shows the state of. After storing apples at 25 ° C. for 10 days with an antibacterial packaging material (d) obtained by bag-making an inflation film produced using a commercially available PP packaging material with a chuck (c) and Cu nanoparticle-carrying PP pellets It is a photograph showing the state. After the bread was stored for 10 days at 25 ° C. with an antibacterial packaging material (d) obtained by bag-fabricating an inflation film produced using a commercially available PP zippered packaging material (c) and Cu nanoparticle-carrying PP pellets It is a photograph showing the state.

  Hereinafter, the present invention will be described in more detail using an embodiment. However, the present invention is not limited to this, and various modifications can be made without departing from the spirit of the present invention. It is possible and limited only by the technical idea described in the claims.

  FIG. 1 shows a process from the production of a metal nanoparticle-supported synthetic resin pellet according to the present invention to a packaging material obtained by bag-making a film molded using the pellet. Hereinafter, the present invention will be described according to this process.

  First, as a synthetic resin for producing a synthetic resin pellet carrying metal nanoparticles, a PP homopolymer pellet made by LOTTE CHEMICAL (HOPELEN FI-150) and a low density PE pellet made by Nippon Polyethylene (Novatech (registered trademark) LD- LF640MA) was used.

  Cu was used as the metal supported on the synthetic resin pellet. PVD method is suitable as a method for depositing the Cu nanoparticles on the synthetic resin pellet, and vacuum deposition, ion beam deposition, ion plating, and various sputtering methods can be used. In the example, an ion beam sputtering method is used as a representative example, and FIG. 2 shows a schematic diagram of a metal nanoparticle production apparatus used in this example.

  In the metal nanoparticle production apparatus of FIG. 1, in a physical vapor deposition tank 1 having at least an ion source 2, a vapor deposition source 3 that is a metal or an alloy thereof, an inert gas introduction system 8, and a vacuum exhaust system 9, the vapor deposition source 3 and vapor deposition are performed. By installing a shutter 4 provided with a slit 5 precisely rotated by a rotary motor 6 between a synthetic resin pellet 10 which is a deposition target material on which a deposition material 7 is deposited, which is provided below the source 3 The vapor deposition material 7 knocked out from the vapor deposition source 3 by the ion source 2 is intermittently vapor deposited on the surface of the synthetic resin pellet 10. Moreover, the screw 11 is connected to the stirring motor 12 at the bottom of the manufacturing apparatus so that the synthetic resin pellets 10 are evenly exposed to the vapor deposition material 7. The synthetic resin pellets 10 circulate along the moving path 14 of the synthetic resin pellets by the screw 11 rotated by the stirring motor 12. That is, the synthetic resin pellet 10-1 at the bottom of the manufacturing apparatus is lifted up like a synthetic resin pellet 10-2, and is vapor deposited intermittently with the synthetic resin pellet 10-3, to which metal nanoparticles are adhered, and then fixed. To the synthetic resin pellet 10-4 which is not exposed to the evaporation source for a period of time. Although a shutter mechanism is provided in FIG. 1, the shutter mechanism is not necessarily required, and the synthetic resin pellet 10 is deposited on the synthetic resin pellet 10 so that the metal nanoparticles can be accurately deposited on the synthetic resin pellet 10. Any mechanism can be employed as long as it can control the exposure time. For example, a method of directly controlling the ion beam emitted from the ion source 2 can be mentioned. Then, the temperature of the entire physical vapor deposition tank 1 is managed by the temperature control device 13.

  The mechanism by which the metal nanoparticles are generated on the surface of the synthetic resin pellet, which is a material to be deposited, is not clear, but is presumed as follows. Volmer-Weber (VW) growth, which is a mode of film deposition mechanism such as general vapor deposition and sputtering, that is, three-dimensional island-like nuclei are formed from the initial stage of growth, and they increase with the amount of vapor deposition. It is an “island growth mode” that grows and coalesces and becomes a continuous film, and it depends on various parameters such as the surface energy and temperature of the deposited material and the deposited material. A difference arises (nonpatent literature 5). The apparatus for producing metal nanoparticles pays attention to the initial stage of film formation of VW growth, and controls the vapor deposition material to be continuously deposited on the synthetic resin pellets so that the vapor deposition time is at least 0.2 sec. If the deposition is performed with stirring, the surface of the new synthetic resin pellet is always directed to the vapor deposition material, so that a continuous film is not formed, and the three-dimensional sea-island structure, that is, the metal nanoparticles are the synthetic resin. It is thought that it produces | generates one after another on the pellet surface.

  In order to narrow the particle size distribution of the metal nanoparticles, the synthetic resin pellet for depositing the metal nanoparticles of the present invention needs to be suppressed to 130 ° C. or lower, and the ambient temperature is controlled by the temperature controller 13 of the physical vapor deposition tank 1. Control below 130 ° C. The lower limit of the atmospheric temperature may be a room temperature of about 25 ° C., and there is no need for special cooling. The reason for the narrowing of the particle size distribution of the metal nanoparticles is not clear, but has already been described.

Specifically, granular LDPE or PP synthetic resin pellets 10 of about 3 to 5 mm are placed in the physical vapor deposition tank 1 shown in FIG. 1, and the vapor deposition source 3 is provided with Cu. Next, the inert gas Ar is introduced into the physical vapor deposition tank 1 from the inert gas introduction system 8 while exhausting from the vacuum exhaust system 9 so that the degree of vacuum of the physical vapor deposition tank 1 becomes 1 × 10 ⁻⁴ to 1 torr. . When the degree of vacuum is stable, while rotating the shutter 4 and the screw 11 with the rotation motor 6 and the agitation motor 12, the Cu of the vapor deposition source 3 with respect to the synthetic resin pellet 10 is 1 Å per unit area until it becomes 0.1% by weight. Evaporate at a rate of 10 μm / min and deposit Cu nanoparticles on the synthetic resin pellets. The evaporation rate is evaporated on a fixed flat substrate and set in advance in a preliminary experiment using a general weight method. The rotational speed corresponding to the shape of the slit 5 of the shutter 4 is such that the deposition time for Cu as the deposition material 7 to be continuously deposited on the synthetic resin pellet 10 is at least 0.2 sec or less with respect to this evaporation rate. And

  The Cu nanoparticles produced in this manner were obtained from an average particle diameter of about 500 particles observed at a photographing magnification of 500,000 in accordance with JIS H 7804: 2005 using a transmission electron microscope (TEM). Asked. FIG. 3 shows an example of a TEM photograph of a film produced by inflation molding, which will be described later, using LDPE pellets carrying Cu nanoparticles, and the average particle diameter was about 3.5 nm. Similar results were obtained when PP pellets were used.

  Then, the Cu nanoparticle-supporting LDPE and PP pellets are directly formed into a 20 μm-thick cylindrical film using a general inflation molding machine shown in FIG. 4, and then a bag making machine (not shown). Then, a packaging material was prepared by a bottom seal method. Although it was a very thin film with a film thickness of 20 μm by inflation molding, a film excellent in surface smoothness and transparency could be produced without any pinholes.

  As described above, the film can be manufactured by inflation molding because the average particle diameter of the Cu nanoparticles of the example of the present invention is 3.5 nm. On the other hand, since the conventional inorganic antibacterial agent ion-exchanged with Ag ions or the like is 500 to 10,000 nm, a film is produced by inflation molding using a mixture of a conventional inorganic antibacterial agent and resin pellets as a raw material. This was difficult due to the occurrence of pinholes by antibacterial agents. Therefore, it is difficult to produce a stretched film. Also, in the case of a film or sheet having a large film thickness by extrusion molding or T-die method, problems of surface roughness and transparency due to the antibacterial agent occur.

  Hereinafter, in order to clarify the antibacterial effect of the antibacterial packaging material of the present invention, commercially available LDPE and PP chuck type packaging materials were used as comparative examples. Put the apple, cooked rice, and tofu into the antibacterial packaging material (b) obtained by bag-making the blown film produced using the commercially available LDPE zippered packaging material (a) and Cu nanoparticle-supported LDPE pellets, The state after storage in a sealed state at 25 ° C. for 10 days was observed. The commercially available packaging material was sealed with a chuck, and the antimicrobial packaging material was sealed with heat sealing.

  An apple and bread were put in an antibacterial packaging material (d) obtained by bag-fabrication processing using a commercially available PP packaging material with a chuck (c) and a blown film made of Cu nanoparticles supported PP pellets. The state after storage in a sealed state for a day was observed. The sealing method is the same.

  These results are shown in FIGS. FIGS. 5 to 7 show an antibacterial product obtained by bag-making an inflation film manufactured using a commercially available LDPE zipper packaging material (a) and Cu nanoparticle-supporting LDPE pellets using apple, cooked rice, and tofu, respectively. It is the result of having compared the packaging material (b). FIGS. 8 and 9 show an antibacterial packaging material obtained by bag-making an inflation film produced using a commercially available PP zippered packaging material (c) and Cu nanoparticle-supporting PP pellets using apple and bread, respectively (d) ).

  As is apparent from the figure, the part that is discolored in black is a corroded part, and the antibacterial packaging material produced using Cu pellet-supporting LDPE and PP pellets is a commercially available LDPE packaging material and PP packaging material. Compared to the material, the progress of corrosion is drastically reduced. This effect is the same result as a similar experiment conducted using Ag nanoparticle-supporting synthetic resin pellets, and that safe and inexpensive metal nanoparticles such as Cu can be used instead of expensive noble metal nanoparticles. Became clear.

  As described above, since the metal nanoparticle-supported synthetic resin pellet of the present invention has a small particle size and a narrow particle size distribution, it has excellent molding processability, particularly film molding processability, antibacterial properties, surface roughness, and transparency. Synthetic resin products having excellent properties can be provided. Moreover, the present invention makes it possible to demonstrate the antibacterial properties, bactericidal properties, fungicidal properties, etc. of Cu using safe and inexpensive metal nanoparticles such as Cu instead of conventional noble metals. It was.

  The present invention is not limited to the thermoplastic resins of the examples, but can also be applied to PS resins, PMMA resins, ABS resins, Ny resins, PET resins, so that antibacterial properties, antiviral properties, bactericidal properties, The present invention can be applied to all kinds of synthetic resin products such as daily goods, home appliances, industrial products, and textile products that require sterilization and mold prevention. For example, household goods include kitchenware, bathware, food containers, etc., household appliances such as refrigerators, washing machines, air conditioners, rice cookers, toilets, and electronic equipment, and industrial products such as food packaging materials and food Examples of textile products such as containers, packaging films, non-woven fabrics, agricultural films, etc. include, but are not limited to, filters, brushes, carpets, artificial hair, clothing and the like.

DESCRIPTION OF SYMBOLS 1 Physical vapor deposition tank 2 Ion source 3 Deposition source 4 Shutter 5 Slit 6 Rotating motor 7 Vapor deposition substance 8 Inert gas introduction system 9 Vacuum exhaust system 10 Synthetic resin pellet 11 Screw 12 Stirring motor 13 Temperature control apparatus 14 Movement path of synthetic resin pellet 15 Resin pellet 16 Loading port 17 Oshida machine 18 Screw 19 Ring die 20 Air hole 21 Air 22 Cylindrical film 23 Stabilizing roll 24 Nip roll 25 Guide roll 26 Winding machine

Claims (16)

  Gold (Au), platinum (Pt), silver (Ag), zinc (Zn), copper (Cu), nickel (Ni) having an average particle diameter of 1 to 50 nm on a spherical or cylindrical synthetic resin pellet , Cobalt (Co), aluminum (Al), and at least one metal nanoparticle selected from an alloy containing at least two kinds of these metals is 0.005 to 0.005 of the synthetic resin pellet. Metal nanoparticle-supporting synthetic resin pellets characterized in that 0.5% by weight is deposited.   The physical vapor deposition method of any one of a vapor deposition method, an ion plating method, and a sputtering method is used, and the thermally decomposed vapor deposition material of the metal vapor deposition source is 130 ° C. on the synthetic resin pellet that is the vapor deposition target. Under the following atmosphere, the vapor deposition material is intermittently deposited on the synthetic resin pellets such that the vapor deposition time during which the vapor deposition material continuously vaporizes on the synthetic resin pellets is at least 0.2 sec, Metal nanoparticles supported synthetic resin pellets, wherein the metal nanoparticles are deposited in an average particle diameter of 1 to 50 nm and 0.005 to 0.5% by weight with respect to the synthetic resin pellets.   The metal nanoparticle-supporting synthetic resin pellet according to claim 1 or 2, wherein the metal is copper.   The said synthetic resin pellet is a thermoplastic resin, The metal nanoparticle carrying | support synthetic resin pellet as described in any one of Claims 1-3 characterized by the above-mentioned.   The thermoplastic resin is selected from vinyl resins, acrylic resins, ABS resins, polyester resins, polyamide resins, polyether resins, polysulfone resins, polyacetal resins, polysulfide resins, and fluororesins. The metal nanoparticle-supported synthetic resin pellet according to claim 4, which is at least one kind of synthetic resin pellet.   The thermoplastic resin is at least one synthetic resin pellet selected from polyethylene resins, polypropylene resins, polystyrene resins, polymethyl methacrylate resins, ABS resins, polyethylene terephthalate resins, and nylon resins. The metal nanoparticle carrying | support synthetic resin pellet of Claim 4 characterized by the above-mentioned.   A synthetic resin molded product using the metal nanoparticle-supported synthetic resin pellet according to any one of claims 4 to 6 as a raw material.   A compression molded article made from the metal nanoparticle-supported synthetic resin pellet according to any one of claims 4 to 6.   A calender molded article using the metal nanoparticle-supported synthetic resin pellet according to any one of claims 4 to 6 as a raw material.   An extrusion molded article using the metal nanoparticle-supported synthetic resin pellet according to any one of claims 4 to 6 as a raw material.   An injection molded article using the metal nanoparticle-supported synthetic resin pellet according to any one of claims 1 to 6 as a raw material.   A hollow molded article made from the metal nanoparticle-supported synthetic resin pellet according to any one of claims 4 to 6.   The inflation film which used the metal nanoparticle carrying | support synthetic resin pellet as described in any one of Claims 4-6 as a raw material.   The stretched film which used the metal nanoparticle carrying | support synthetic resin pellet as described in any one of Claims 4-6 as a raw material.   A T-die molded film using the metal nanoparticle-supported synthetic resin pellet according to any one of claims 4 to 6 as a raw material.   The physical vapor deposition method of any one of a vapor deposition method, an ion plating method, and a sputtering method is used, and the thermally decomposed vapor deposition material of the metal vapor deposition source is 130 ° C. on the synthetic resin pellet that is the vapor deposition target. In the following atmosphere, the vapor deposition material is intermittently deposited on the synthetic resin pellet so that the vapor deposition time during which the vapor deposition material is continuously vapor deposited on the synthetic resin pellet is at least 0.2 sec or less. The method for producing a metal nanoparticle-supported synthetic resin pellet according to any one of claims 1 to 6.

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