JP2004107675A - Antibacterial composite resin, antibacterial composite resin composition and method for producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an antibacterial material easily and uniformly mixable with a synthetic resin, exhibiting stable antibacterial effect on the surface of the synthetic resin, hardly causing environmental pollution even if eluted from the synthetic resin and damaging no appearance of the surface of the synthetic resin. <P>SOLUTION: The antibacterial material is solubilized to prepare a solution of the antibacterial material, a colloidal inorganic oxide is compounded in the solution as a carrier particle to adsorb the antibacterial material on the surface of the carrier particle, a chlorinated polypropylene resin emulsion is mixed with the solution and the solution is dried at a temperature below the melting point of the resin to obtain an antibacterial composite resin. A resin pellet is compounded into the antibacterial composite resin solution and the solution is dried at a temperature below the melting point of the resin and the resin pellet to obtain antibacterial composite resin composition. <P>COPYRIGHT: (C)2004,JPO

Description

  The present invention relates to an antibacterial composite resin, an antibacterial composite resin composition, and a method for producing the same.

  In recent years, synthetic resins have been used in various fields, and many synthetic resin products have become widespread in our daily lives. Along with this, when synthetic resin is used in a field where attention must be paid to hygiene, such as kitchen utensils, contamination of the surface of the synthetic resin by bacteria has become a problem. In addition, when a synthetic resin is used as a caulking material for architectural materials, a problem of deterioration in appearance in addition to hygienic problems is caused by bacteria and mold contamination.

  As a countermeasure against such contamination of the surface of the synthetic resin by bacteria and mold, a synthetic resin product having an antibacterial effect by attaching an antibacterial substance to the surface of the synthetic resin has been developed and put into practical use. As a method for attaching the composition, a method is generally used in which an antimicrobial substance is mixed into a synthetic resin to expose the composition on the surface of the synthetic resin. Examples of the antibacterial substance include an organic antibacterial agent and a silver antibacterial agent using silver ions. In particular, when it is desired to provide an excellent antibacterial effect, an organic antibacterial agent such as thiabendazole is used. Products using terpene compounds extracted from plants as antibacterial substances have also been developed (see Patent Documents 1, 2 and 3).

Furthermore, since the antibacterial performance of the antibacterial agent attached to the synthetic resin product is not permanent, as another countermeasure against contamination of the synthetic resin surface by bacteria or mold, chlorine-based substances such as sodium hypochlorite should be periodically checked. Surface disinfection has been performed using bleach.
JP-A-63-30424 JP-A-61-228283 JP-A-61-268934

  However, in the conventional technique, since the antibacterial substance is used as it is, there is a problem that it is difficult to knead it with a synthetic resin. That is, in order to uniformly disperse the antibacterial substance in the synthetic resin, it is necessary to add a dispersing aid, and it is necessary to always study the temperature conditions during kneading, and it is necessary to perform several kneading operations. The kneading process is not only time-consuming but also expensive, and as a result, synthetic resins having antibacterial properties are expensive.

Furthermore, the conventional antibacterial agents have the following problems. First, the organic antibacterial agent has a problem that it is easily eluted from the synthetic resin due to its volatility, and if it is eluted, the surrounding environment is contaminated. In the case of a silver-based antibacterial agent using silver ions (Ag ⁺ ), if a bleaching agent commonly used in the kitchen is used, silver ions react with chlorine ions in a chlorine-based bleach to form insoluble silver chloride, Furthermore, since silver chloride has a high photoreaction activity, it immediately changes to metallic silver or silver oxide, which causes a problem that not only blackening occurs but also antibacterial performance decreases. Also, in the case of a silver-based antibacterial agent using silver ions, the refractive index of the carrier kneaded together in the resin to stabilize the silver salt is different from that of the kneaded resin, so that the resin is made opaque or the carrier absorbs moisture. There is also a problem such as impairing the smoothness of the molding resin surface due to the property. In the case of plant-derived antibacterial agents, most of the substances present in plants are aromatic substances and have volatility, so when these substances are mixed into resin, they are evaporated by heating during molding of the resin. Therefore, there is a problem that the effect can hardly be expected.

  The present invention solves the above-mentioned conventional problems, can be easily and uniformly mixed with a synthetic resin, exhibits a stable antibacterial effect on the surface of the synthetic resin, and does not easily cause environmental pollution even when eluted from the synthetic resin. Provided are an antibacterial composite resin which does not impair the appearance of the surface, an antibacterial composite resin composition, and a method for producing the same.

  In order to achieve the above object, the antibacterial composite resin of the present invention has a configuration in which carrier particles are dispersed in the resin, and the carrier particles carry an antibacterial substance.

  By adopting such a configuration, the conventional problem caused in the step of kneading the antibacterial substance into the synthetic resin can be solved. That is, by further dispersing the carrier particles carrying the antibacterial substance in the resin, the antibacterial substance is less likely to aggregate, and is uniformly dispersed in the synthetic resin. Further, the antibacterial composite resin is softened by heating, and by disposing the resin around the resin, uniform dispersion in the resin is facilitated without using a dispersing aid. As a result, the time required for the kneading step as in the related art can be omitted, the time of the kneading step can be shortened, and the cost of the kneading step can be reduced.

  In the present invention, the carrier particles are preferably at least one oxide colloid selected from the group consisting of colloidal silica, colloidal alumina, and colloidal titanium. In the present invention, the resin is preferably a chlorinated polypropylene resin.

  In the antibacterial composite resin composition of the present invention, the antibacterial composite resin adheres to the surface of the resin pellet.

  In the present invention, the resin pellet is preferably at least one resin pellet selected from the group consisting of a polyethylene pellet, a polypropylene pellet, and a chlorinated polypropylene pellet.

  Next, in the method for producing the antibacterial composite resin of the present invention, an antibacterial substance is solubilized to prepare an antibacterial substance solution, and carrier particles are added to the solution, and the antibacterial substance is adsorbed on the surface of the carrier particles. The solution is mixed with a resin emulsion, and then the solution is dried.

  According to this manufacturing method, by drying the solution and removing the dispersion medium, the emulsion resins further supporting the carrier particles supporting the antibacterial substance are mutually aggregated to form one resin mass. Accordingly, the antibacterial composite resin of the present invention in which the carrier particles are dispersed in the resin is formed.

  In addition, the method for producing the antibacterial composite resin composition of the present invention comprises preparing an antibacterial substance solution by solubilizing an antibacterial substance, blending carrier particles with the solution, and applying the antibacterial substance on the surface of the carrier particles. In this method, a resin emulsion is mixed with the solution, resin pellets are added to the solution, and the solution is dried.

  A preferred example of the method for producing the antibacterial composite resin of the present invention is an antibacterial substance comprising at least one metal salt selected from silver, copper, and zinc acetates, sulfates, and nitrates. The content of the metal is 0.1 to 10 parts by weight based on 100 parts by weight of the antibacterial substance prepared by adding at least one of sulfite ions and thiosulfate ions to 1 part by mole of the metal salt. An antibacterial substance solution comprising a thiosulfato metal complex solution is prepared, and an inorganic oxide colloid as a carrier particle is added to the solution at a ratio of 0.1 to 50 parts by weight in terms of solid content based on 100 parts by weight of the thiosulfato metal complex solution. And further mixed with the olefin-compatible resin emulsion based on 100 parts by weight of the thiosulfato metal complex solution in terms of resin solid content of 0.5 to 0.5 parts by weight. 0 were added at a ratio of parts by weight and then a method of drying at a melt temperature below the temperature of the resin.

  Further, a preferred example of the method for producing the antibacterial composite resin composition of the present invention is to prepare an antibacterial composite resin solution by the above-described method, and to prepare a resin having compatibility with the emulsion resin and having thermoplasticity. On the surface of the pellet, a resin pellet is applied at a rate of 200 to 10000 parts by weight based on 100 parts by weight of the thiosulfato metal complex solution, and then dried at a temperature equal to or lower than a melting temperature of the resin and the resin pellet. .

  In the present invention, for example, as an antibacterial substance, when using at least one thiosulfato metal complex selected from the group consisting of a thiosulfato silver complex, a thiosulfato zinc complex, and a thiosulfato copper complex, the thiosulfato metal complex is stable. Not only is the photostability obtained, but also the stability of chlorine is secured because the complex forms an anion, and the problem of reaction with chlorine when using a chlorine bleach is solved.

In the method for producing the antibacterial composite resin and the antibacterial composite resin composition of the present invention, the above-mentioned oxide colloid is preferable as the carrier particles.
By using such carrier particles, it is needless to say that the thermal stability of the antibacterial substance can be obtained. Even if the carrier is kneaded with the resin, the resin surface is not opaque and the smoothness of the resin surface is improved. No damage.

  In the method for producing the antibacterial composite resin and the antibacterial composite resin composition of the present invention, the emulsion resin is preferably a chlorinated polypropylene resin emulsion.

  The olefin-based resin (synthetic resin) is not compatible unless it is the same olefin-based resin, and the olefin-based resin is hardly soluble in a solvent system such as an organic solvent. Therefore, it is preferable to use a chlorinated polypropylene resin which is compatible with the olefin system and can form an emulsion. Thereby, a resin which can be molded by mixing with a soluble antibacterial substance in a solvent system and drying, that is, the antibacterial material of the present invention can be constituted.

  Furthermore, in the method for producing the antibacterial composite resin composition of the present invention, the resin pellets described above are preferably used.

  Next, the present invention will be specifically described. The antibacterial composite resin of the present invention has carrier particles dispersed in the resin, and the carrier particles carry an antibacterial substance.

  The carrier particles are not particularly limited as long as they carry and adsorb the antibacterial substance and adhere to the resin in the emulsion. Among them, inorganic oxide colloids such as colloidal silica, colloidal alumina, and colloidal titanium are preferable because they do not impair the appearance of the resin even when kneaded in the resin, as described above. The particle size of the inorganic oxide colloid used as a support is usually 0.01 to 10 μm. That is, when the thickness is 0.01 μm or less, the supporting effect is small. On the other hand, when the thickness is 10 μm or more, the surface of the resin molded product can be visually identified and causes roughness on the surface. The heat stability of the antibacterial substance is further obtained by supporting the antibacterial substance on the carrier particles.

  When kneading the antibacterial composite resin to the synthetic resin, the resin is included for facilitating kneading.Therefore, the resin is compatible with the synthetic resin, is thermoplastic, and is contained in an organic solvent. Preferably, it can be dispersed. Examples of such a resin include chlorinated polypropylene.

  The antibacterial substance is preferably a thiosulfato metal complex, particularly a thiosulfato silver complex, a thiosulfato zinc complex, a thiosulfato copper complex, or a mixture thereof, using metal acetates, sulfates, and nitrates as raw materials. This is because not only are these complexes stable, so that light stability can be obtained, but also, since the complexes form anions, stability to chlorine is ensured.

  In the antibacterial composite resin composition of the present invention, the antibacterial composite resin is attached to the surface of a resin pellet. When preparing an antibacterial synthetic resin, the antibacterial composite resin composition may be molded as it is, or may be dispersed in another synthetic resin such as polyolefin and molded. The resin pellet is preferably compatible with the resin of the antibacterial composite resin, and is particularly preferably made of a thermoplastic resin compatible with a synthetic resin such as polyolefin. Most preferably, they are polyethylene resin pellets, polypropylene resin pellets, chlorinated polypropylene resin pellets and the like.

A thiosulfato metal complex solution was prepared using silver acetate as a raw material. That is, first, silver acetate was dissolved in water at a temperature of 60 ° C. or less at 7.7 g / l, which is close to the solubility, to prepare a silver acetate aqueous solution. To this, Na ₂ SO ₃ .7H ₂ O was added at a ratio of Na ₂ SO ₃ / CH ₃ CO OAg = 2.7 g / 1 g, and after sufficient stirring, Na ₂ S ₂ O ₃ .5H ₂ O was added to Na ₂ SO ₃ .5H ₂ O. ₂ S ₂ O ₃ / CH ₃ COOAg = 6.6 g / 1 g was added. Further, the amount of zinc acetate was reduced to zinc and twice the amount of added silver was added to obtain a thiosulfato metal complex solution. This series of dissolving steps was performed under a temperature condition of 40 ° C. to room temperature.

  Boehmite colloid (solid content: about 10%, colloidal silica AS-200, manufactured by Nissan Chemical Industries, Ltd.) was added to the thiosulfato metal complex solution, and the mixture was uniformly stirred and mixed. Here, the blending ratio of the boehmite colloid was 20 parts by weight based on 100 parts by weight of the thiosulfato metal complex solution. The particle size was about 0.1 μm.

Further, an organic solvent emulsion of a chlorinated polypropylene resin is added at a ratio of 20 parts by weight with respect to 100 parts by weight of the thiosulfato metal complex solution, and the mixture is uniformly stirred and mixed. After drying, an antibacterial composite resin was obtained. The drying conditions are not limited to the above, and are usually ^10-4 to normal pressure Pa and 40-120 ° C.

  The antibacterial composite resin produced by the above method was uniformly dispersed in the resin at the time of molding the polypropylene resin to produce a resin molded product. The weight ratio of the antibacterial composite resin was 0.015 parts by weight in terms of silver in the resin molded product when the resin molded product was 100 parts by weight.

  In addition, it is also possible to replace part or all of sodium ions in the above-mentioned raw materials with potassium ions, and an antibacterial composite resin using potassium ions can be obtained, although its properties are slightly inferior but are not harmful to practical use. Have been confirmed by the present inventors.

  Furthermore, in this example, silver acetate was used as the soluble metal salt. However, even if zinc acetate, other soluble zinc salts or soluble copper salts were used, the antibacterial complex with practically no problem, although its properties were slightly inferior. A resin is obtained.

  To an antibacterial composite resin dispersion prepared in the same manner as in Example 1, 333 parts by weight of a polypropylene resin was added to 100 parts by weight of a thiosulfato metal complex, and after uniform mixing, at normal pressure and 60 ° C. The mixture was dried under the conditions to obtain an antibacterial composite resin composition.

  The antibacterial composite resin composition produced by the above method was uniformly dispersed in the resin at the time of molding the polypropylene resin to produce a resin molded article. The weight ratio of the antibacterial resin pellet was 1 part by weight based on 20 parts by weight of the polypropylene natural resin.

(Comparative example)
An antibacterial composite resin was prepared in the same manner as in Example 1 without containing an antibacterial substance, and this was uniformly dispersed in the resin during molding of the polypropylene resin to obtain a resin molded article. The weight ratio of the antibacterial material was 1 part by weight based on 20 parts by weight of the polypropylene natural resin.

  Antibacterial tests were performed on the resin molded bodies of Examples 1 and 2 and Comparative Example 1 thus produced by the following method. The results are shown in Table 1 below.

[Antibacterial test]
As test bacteria, E. coli coli, S .; aureus, B .; Using a subtilis, the viable count after 24 hours was measured according to the titration method. The evaluation was performed in comparison with the viable cell count for the resin molded article of the comparative example, and the antibacterial performance effect was determined to have been obtained in the experimental plot in which the cell count decreased by 102 or more.

  From Table 1 above, it can be seen that the antibacterial composite resin and the antibacterial composite resin composition of this example have practical antibacterial performance.

  Based on the methods described in Examples 1 and 2, resin moldings were prepared with various conditions changed as shown in Table 2 below, and their antibacterial performance, workability during production, and color tone surface condition were mainly used. The appearance of the finished molding was evaluated. The results are also shown in the table.

[Antibacterial test]
As test bacteria, E. coli coli, S .; aureus, B .; Using a subtilis, the number of viable cells after 24 hours was measured according to the titration method. The evaluation was performed in comparison with the viable cell count for the resin molded body of the comparative example.
○: 10 ² or more reduction in the number of viable cells △: 10 ² of the viable cell count decrease ×: 10 ² following the reduction in the number of viable bacteria

  The following can be seen from Table 2 above. A resin molded article to which no metal complex as an antibacterial substance is added does not exhibit antibacterial performance. In addition, a resin molded body to which no colloidal oxide is added even when an antibacterial substance is added, not only does not exhibit antibacterial performance, but also has a blackened resin surface. Also, among those containing both, the molded resin body to which chlorinated polypropylene was added as a resin emulsion exhibited antibacterial performance and improved appearance and workability. That is, when a resin molded body is manufactured using an antibacterial composite resin composed of an antibacterial substance, colloidal oxide, and chlorinated polypropylene resin, not only excellent antibacterial performance is exhibited, but also workability is improved, and resin molding is improved. It can be seen that the appearance of the body is not impaired.

  As described above, in the antibacterial composite resin of the present invention, the carrier particles are dispersed in the resin, and the carrier particles carry the antibacterial substance. That is, by adopting such a configuration, when kneading it with a synthetic resin, it can be easily and uniformly dispersed without using a dispersing aid. In addition, by adopting such a configuration, the stability of the antibacterial substance is increased, it is difficult to elute from the synthetic resin, and it is unlikely to cause environmental pollution. Further, when the stability of the antibacterial substance increases, the antibacterial performance stability of the synthetic resin surface can be expected to be improved. In addition, when an inorganic oxide colloid is used as the carrier particles, there is an effect that the transparency of the resin and the smoothness of the resin surface are not impaired and are maintained as they are. In addition, when a thiosulfato metal complex is used as an antibacterial substance, the antibacterial substance itself is stable, and thus not only exhibits a more stable antibacterial action, but also forms an outer shell coating layer on the surface of the antibacterial substance. It has a sustained release property and improved thermal stability. Further, when a thiosulfato metal complex is used as the antibacterial substance, no discoloration occurs even when used in an atmosphere having a high chlorine concentration, and a decrease in antibacterial performance is prevented. By using silver sulfate instead of silver acetate as a raw material of the thiosulfato metal complex, residual acetic acid in the produced thiosulfato metal complex solution is eliminated, and the odor of acetic acid of the antibacterial substance and the acetic acid odor at the time of resin kneading and molding of the antibacterial material are reduced. There is an effect that it can be removed.

  And in this invention, a pellet or a masterbatch is produced directly from an antibacterial composite resin. In the present invention, since a masterbatch is manufactured using a liquid antibacterial substance as a raw material and passing through a liquid antibacterial material, the number of steps in the antibacterial operation process can be reduced as compared with the conventional method. As a result, the cost in the antibacterial operation step can be reduced, and further, the cost of the synthetic resin having antibacterial performance can be expected to be reduced.

FIG. 3 is a process chart showing one embodiment of the production method of the present invention.

Claims (14)

An antibacterial composite resin in which carrier particles are dispersed in a resin, and the carrier particles carry an antibacterial substance. The antibacterial composite resin according to claim 1, wherein the carrier particles are at least one oxide colloid selected from the group consisting of colloidal silica, colloidal alumina, and colloidal titanium. 3. The antibacterial composite resin according to claim 1, wherein the resin is a chlorinated polypropylene resin. An antibacterial composite resin composition, wherein the antibacterial composite resin according to claim 1 is attached to a surface of a resin pellet. The antibacterial composite resin composition according to claim 4, wherein the resin pellet is a thermoplastic resin compatible with an olefin resin such as polyethylene, polypropylene, and chlorinated polypropylene resin. The antibacterial substance is solubilized to prepare an antibacterial substance solution, carrier particles are blended in the solution, the antibacterial substance is adsorbed on the surface of the carrier particles, a resin emulsion is mixed with the solution, and the solution is dried. For producing an antibacterial composite resin. The antibacterial substance is solubilized to prepare an antibacterial substance solution, carrier particles are blended in the solution, the antibacterial substance is adsorbed on the surface of the carrier particles, a resin emulsion is mixed with the solution, and a resin pellet is added to the solution. And then drying the solution to produce an antibacterial composite resin composition. At least one metal salt selected from the group consisting of acetate, sulfate and nitrate of at least one metal selected from silver, copper and zinc is used as an antibacterial substance, and at least one of sulfite ion and thiosulfate ion is 1 mol of the metal salt. An antibacterial substance solution comprising a thiosulfato metal complex solution having a metal content of 0.1 to 10 parts by weight with respect to 100 parts by weight of the antibacterial substance prepared by adding 2 to 15 mol of An inorganic oxide colloid is added as carrier particles to the thiosulfato metal complex solution at a ratio of 0.1 to 50 parts by weight in terms of solid content with respect to 100 parts by weight of the thiosulfato metal complex solution, and further mixed with an olefin-compatible resin emulsion. The resin was added in an amount of 0.5 to 50 parts by weight in terms of resin solid content with respect to 100 parts by weight of the solution, and then the melting temperature of the resin Method for producing an antimicrobial composite resin according to claim 6, wherein the drying at a temperature below. At least one metal salt selected from the group consisting of acetate, sulfate and nitrate of at least one metal selected from silver, copper and zinc is used as an antibacterial substance, and at least one of sulfite ion and thiosulfate ion is 1 mol of the metal salt. An antibacterial substance solution comprising a thiosulfato metal complex solution having a metal content of 0.1 to 10 parts by weight with respect to 100 parts by weight of the antibacterial substance prepared by adding 2 to 15 mol of An inorganic oxide colloid is added as carrier particles to the thiosulfato metal complex solution at a ratio of 0.1 to 50 parts by weight in terms of solid content with respect to 100 parts by weight of the thiosulfato metal complex solution. The resin particles were added at a ratio of 0.5 to 50 parts by weight in terms of resin solid content with respect to 100 parts by weight of the solution, The thiosulfato metal complex solution after addition of the fat emulsion, on the surface of the resin pellets having compatibility with the emulsion resin and having thermoplasticity, the resin pellets are 200 to 10,000 parts by weight based on 100 parts by weight of the thiosulfato metal complex solution. The method for producing an antibacterial composite resin composition according to claim 7, wherein the resin composition is applied at a rate equal to or lower than the melting temperature of the resin and the resin pellet. 9. The method for producing an antibacterial composite resin according to claim 6, wherein the carrier particles are at least one oxide colloid selected from the group consisting of colloidal silica, colloidal alumina, and colloidal titanium. The method for producing an antibacterial composite resin according to any one of claims 6, 8, or 10, wherein the resin emulsion is a chlorinated polypropylene resin emulsion. The method for producing an antibacterial composite resin composition according to claim 7 or 9, wherein the carrier particles are at least one oxide colloid selected from the group consisting of colloidal silica, colloidal alumina, and colloidal titanium. The method for producing an antibacterial composite resin composition according to any one of claims 7, 9 or 12, wherein the resin emulsion is a chlorinated polypropylene resin emulsion. The antibacterial composite resin composition according to any one of claims 7, 9, 12, and 13, wherein the resin pellet is a thermoplastic resin compatible with an olefin resin such as polyethylene, polypropylene, and chlorinated polypropylene resin. Manufacturing method.

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