JP3372275B2 - Manufacturing method of antibacterial resin molded product - Google Patents

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to an antibacterial resin molded product obtained by imparting antibacterial properties to a molded product made of a thermosetting resin or a thermoplastic resin.
The present invention relates to a method of manufacturing . In particular, the present invention relates to a method for producing an antibacterial resin molded product used for applications such as a grip of hanging leather that is touched by an unspecified number of people .

[0002]

2. Description of the Related Art Suspended leather is generally used as a method of ensuring passenger safety in transportation facilities. Thermosetting resins such as urea resin and melamine resin have been generally used as the material for the grip of hanging leather, but recently, more beautiful methacrylic resin, styrene resin, acrylonitrile-styrene resin have been used. Thermoplastic resins prepared by injection molding such as polymer resins, acrylonitrile / butadiene / styrene copolymer resins, and polycarbonate resins have also been used.

[0003] The hanging leather has sufficient mechanical strength as a safety measure for passengers, but hygiene has not been taken into consideration. That is, although the grip of the hanging leather is beautiful to the eye, it is actually unsanitary because it is used by an unspecified number of people, and in addition to contamination by sweat and hand marks, various bacteria such as molds, Escherichia coli, and Trichophyton There is a large amount of adhesion and there is a risk of infection such as skin diseases due to contact infection.

Although the doors of transportation facilities are rarely fully touched by the hands, since the hanging leather is grasped by the hands, it is unavoidable to touch it. It is also impossible to disinfect the grip of the hanging leather after each use.

The same applies to not only hanging leather but also resin moldings that are contacted by an unspecified number of people, such as bathhouse equipment, toilet seat sheets, edible knives, and bathtubs.

Therefore , various measures have been proposed for solving the above problems. For example, Actual Kaihei 1-963
Japanese Unexamined Patent Publication No. 48 proposes a hanging-skin wheel in which a member containing copper is exposed on the surface of the hanging-skin wheel. 62-59
Japanese Patent No. 028 discloses an antibacterial bath fixture to which a chlorinated phenolic compound is added and blended. Japanese Utility Model Laid-Open No. 2-13487 discloses an antibacterial toilet seat sheet in which an antibacterial sheet is inserted into the toilet seat of a Western-style toilet bowl. Japanese Utility Model Laid-Open No. 1-178876 discloses an aseptic edible product in which the surface of an edible knife is made of an antibacterial material composed of a sheet of a thermoplastic resin mixed with an antibacterial zeolite and a thermoplastic resin sheet fused or bonded to the sheet. A knife is shown. Japanese Unexamined Patent Publication (Kokai) No. 1-313531 discloses a synthetic resin molded product (bathroom curtain, bathtub, etc.) in which powdery particles of water-soluble glass containing monovalent silver are mixed and supported.

[0007]

As a method of imparting antibacterial properties to a resin molded product, pellets prepared by previously kneading an organic or inorganic antibacterial agent into the resin are mixed with the molding resin and used for molding. The masterbatch method is widely adopted, but in this case not only the antibacterial agent that has entered the resin has no effect, but also many antibacterial agents near the resin surface are wrapped in the resin film, so a sufficient effect is obtained. I can't expect.

In addition, in order to improve the antibacterial effect, it is necessary to mix a large amount of the antibacterial agent, but in the case of an inorganic antibacterial agent, the mechanical strength of the resin molded product may be deteriorated due to the mixing of the antibacterial agent fine particles. However, in the case of an organic antibacterial agent as well, the mechanical strength is adversely affected, and a strong antibacterial property is not suitable for use in contact with humans in terms of toxicity.

Under such circumstances, the present invention produces a safe antibacterial resin molded article having a large antibacterial action, which is suitable for use by an unspecified number of people such as a grip of hanging leather .
The purpose is to provide a method of

[0010]

The method for producing an antibacterial resin molded article according to the present invention comprises the steps of treating a resin molded article with an inorganic antibacterial agent dispersion liquid and reducing the pressure.
Characterized in that after being brought into contact with each other under conditions or under pressure , it is washed with water and dried to form an inorganic antibacterial agent-supporting layer on the surface of the resin molded product by permeation of the inorganic antibacterial agent dispersion liquid. Is.

The present invention will be described in detail below.

As the resin molded product, those used for the purpose of being touched by an unspecified number of people are preferably used. Examples of such a resin molded product include a resin plate, a rod, a pipe, a sheet, a film, a foam, an elastomer, other various molded products and a composite molded product, and specifically, a grip portion of a hanging leather is first mentioned. , In addition, interior materials such as telephone handsets, earphones for passengers in transportation, toilet seats, handrails, bath fixtures, stair handrails, chairs and benches in waiting rooms, faucet cocks for hand-washing, and car handles. Also,
Food packaging films and food trays in the market, construction materials such as wall materials, various hoses, dining room tables,
The operation buttons of elevators and NC devices, touch panels of automatic cashier, various keyboards, etc. are often touched by unspecified people, so they can be applied to such applications. Furthermore, even in the house, toothbrushes, earplugs, combs, shaving equipment, washbasins, sinks, cutting boards, toys,
Baby bottles, pacifiers, plastic beverage containers, garbage bags and bins, refrigerators, washing machines, vacuum cleaners, etc. are not used by an unspecified large number, but if applied to such applications, they are clean and hygienic. . Moreover, hospital crockery, syringe body, stethoscope, surgical gloves, various trays, drip bottles, and the catheter, the resin portion of the other medical device can be applied to applications to prevent nosocomial infections in hospitals such as plastic fixtures.

As the types of resins constituting the resin molded product, various thermosetting resins and thermoplastic resins can be mentioned.
If the resin molded product is the grip of the hanging leather, urea resin,
Thermosetting resin such as melamine resin, methacrylic resin,
Examples include thermoplastic resins such as styrene resin, acrylonitrile / styrene copolymer resin, acrylonitrile / butadiene / styrene copolymer resin, polycarbonate resin, and polyarylate resin. In the case of a thermosetting resin, a thermoplastic resin is produced by compression molding. In the case of 1, the holding part of the hanging leather is formed by the injection molding method.

The resin material used for other purposes is not particularly limited, but examples of the thermosetting resin include phenol resin, unsaturated polyester resin, epoxy resin, silicone resin, xylene resin, furan resin and diallyl phthalate resin. As the thermoplastic resin, polyvinyl chloride resin, vinyl chloride copolymer resin, polyvinyl butyral resin, polyvinyl formal resin, polyvinyl alcohol resin, polyvinylidene chloride resin, polyvinyl acetate resin, polyvinyl dichloride resin, chlorinated poly Ether resin,
Ethylene / vinyl acetate copolymer resin, polyethylene resin,
Polypropylene resin, polyamide resin, polyacetal resin, ethyl cellulose resin, cellulose acetate resin, acetic acid / butyric acid cellulose resin, propyl cellulose resin, cellulose nitrate resin, polyethylene terephthalate resin,
Polybutylene terephthalate resin, various fluorine resins,
Elastomers such as polyurethane resin include natural rubber, isoprene rubber, acrylonitrile rubber, butadiene rubber, butyl rubber, styrene rubber, chloroprene rubber, acrylic rubber, chlorohydrin rubber, ethylene propylene terpolymer rubber. Examples thereof include rubber, ethylene / vinyl acetate rubber, urethane rubber, polysulfide rubber, silicone rubber, fluorine rubber and fluorosilicone rubber.

As the inorganic antibacterial agent, at least one metal selected from the group consisting of silver, copper, zinc, mercury, lead, bismuth, cadmium and chromium, in addition to inorganic fine particles or inorganic ion exchanger fine particles ( In particular, an inorganic antibacterial agent supporting silver, copper or zinc) is used. By supporting these antibacterial metals alone or in combination of two or more, it is possible to design the antibacterial metal to suit the purpose of use or to exert a synergistic effect. The organic antibacterial agent is
Since it has a high migration property, it is difficult to retain it on the surface of the resin molded product for a long period of time, and since it is often toxic to the human body, it is not suitable for the purpose of the present invention.

To form the inorganic antibacterial agent-supporting layer on the surface of the resin molded article, first, an aqueous dispersion of inorganic antibacterial agent particles is prepared. In order to enhance the suspension stability of the inorganic antibacterial agent fine particles, various kinds of surfactants such as nonionic, cationic, and anionic surfactants can be added. In addition, add various protective colloids and dispersion aids as dispersion stabilizers,
It is also effective to add various polymers to enhance the fixing of fine particles, if necessary.

The particle size of the inorganic antibacterial agent in the inorganic antibacterial agent dispersion is 1 μm or less, preferably 0.7 μm or less, from the viewpoint of the permeability of the resin molded product into the fine pores and the stability of the dispersion. It is particularly desirable that the thickness is 0.5 μm or less.
Since commercially available inorganic antibacterial agents often have a particle size of several μm to several tens of μm, in such a case, they are finely pulverized before use.

An impregnation method is used to bring the resin molded product into contact with the inorganic antibacterial agent dispersion liquid. In this case, it is desirable to heat the inorganic antibacterial agent dispersion liquid. However, even if it is heated unnecessarily, it only deteriorates the resin molded product and is meaningless, so it is at most about 70 ° C, usually 40 to 60 ° C.
Moderate heating is sufficient. A treatment time of about 5 minutes to 30 minutes is sufficient.

In the above-mentioned impregnation operation , in order to make the impregnation effect more reliable, impregnation is carried out under reduced pressure condition or pressurized condition, and the inorganic antibacterial agent is deeply spread on the surface of the resin molded product and deep inside the surface. Allow it to penetrate .

After the impregnation operation is completed, the resin molded product is taken out from the aqueous dispersion of the inorganic antibacterial agent, washed with water and dried. Thereby, the inorganic antibacterial agent carrying layer is formed on the surface of the resin molded product.

The thickness of this carrier layer varies somewhat depending on the material resin of the resin molded product, but is usually several μm to several tens μm.
Reached 1 and the optimum impregnation conditions were adopted
It reaches as high as 00 μm.

[0022]

The resin molded product, whether it is a compression molded product, an injection molded product or an extrusion molded product, has fine pores on its surface (which can be confirmed by a microscope). A gap can also be formed in the crystal structure by swelling the resin. The inorganic antibacterial agent dispersion permeates into these fine pores.
The depth is promoted when impregnation is performed under reduced pressure or pressure, and when the inorganic antibacterial agent dispersion is heated,
Be promoted.

The inorganic antibacterial agent used in the present invention (inorganic microparticles or inorganic ion exchanger microparticles carrying antibacterial metal such as silver, copper or zinc) is
Unlike organic antibacterial agents that exhibit antibacterial activity by diffusing into the air or solvent due to volatilization or elution, they readily dissociate in the presence of water in the environment to form antibacterial metal ions that exhibit antibacterial effects. It exerts an antibacterial effect by "active oxygen anions" generated on the surface of the antibacterial agent due to the catalytic action of the antibacterial metal, and acts on a wide range of bacteria, mold and algae spores. It is tasteless, odorless and nontoxic. Therefore, the safety is high and the effect can be maintained for a long time.

The resin molded product on which the inorganic antibacterial agent-supporting layer is formed does not change its appearance, feel, size, mechanical strength, odorlessness, etc., as compared with the untreated resin molded product. .

[0025]

EXAMPLES The present invention will be further described with reference to examples. Hereinafter, "%" means% by weight.

Examples 1-9(Reference example) <Preparation of aqueous dispersion of inorganic antibacterial agent> The following nine types of inorganic antibacterial agent aqueous dispersions were prepared. (A)
~ (I) correspond to Examples 1 to 9, respectively.

(A) "AIS-NAZ32" manufactured by Catalyst Kasei Kogyo Co., Ltd. in which silver or the like is supported on silica type carrier fine particles.
An aqueous dispersion of an inorganic antibacterial agent having a composition of about 6% of fine particles obtained by pulverizing "0" (average particle size of 1 to 5 µm) to a particle size of 0.5 µm or less and about 94% of water.

(B) "AIS-NAC41" manufactured by Catalyst Kasei Kogyo Co., Ltd. in which copper or the like is supported on silica carrier fine particles.
An aqueous dispersion of an inorganic antibacterial agent having a composition of about 6% of fine particles obtained by pulverizing "0" (average particle size of 1 to 5 µm) to a particle size of 0.5 µm or less and about 94% of water.

(C) About 6% of fine particles obtained by crushing "Bactekiller BM101A" (average particle diameter 2 μm) manufactured by Kanebo Co., Ltd., in which fine particles of zeolite-based carrier are loaded with silver and zinc, to a particle diameter of 0.5 μm or less, and water. An inorganic antibacterial agent aqueous dispersion having a composition of about 94%.

(D) About 6% of fine particles obtained by crushing "Bactekiller BM501A" (average particle diameter 5 μm) manufactured by Kanebo Co., Ltd., in which silver and zinc are supported on zeolite-based carrier fine particles to a particle diameter of 0.5 μm or less, and water. An inorganic antibacterial agent aqueous dispersion having a composition of about 94%.

(E) A composition comprising about 6% of fine particles obtained by crushing "Zeomic AJ10D" manufactured by Sinanen Zeomic Co., Ltd. in which silver or the like is supported on fine particles of zeolite-based carrier to a particle size of 0.5 μm or less, and about 94% of water. Inorganic antibacterial agent aqueous dispersion.

(F) A composition comprising about 6% of fine particles obtained by crushing "Zeomic AG10NA" manufactured by Sinanen Zeomic Co., Ltd., in which silver or the like is carried on fine particles of zeolite-based carrier, to a particle size of 0.5 μm or less, and about 94% of water. Inorganic antibacterial agent aqueous dispersion.

(G) A composition comprising about 6% of fine particles obtained by crushing "Zeomic AW10D" manufactured by Sinanen Zeomic Co., Ltd. in which silver or the like is supported on fine particles of zeolite-based carrier to a particle size of 0.5 μm or less, and about 94% of water. Inorganic antibacterial agent aqueous dispersion.

(H) Particle size of "Apacider AW3" (particle size 1-2 μm) manufactured by Sangi Co., Ltd. in which antibacterial metal ions such as silver and zinc are exchange-adsorbed on calcium phosphate.
An inorganic antibacterial agent aqueous dispersion having a composition of about 6% fine particles pulverized to 0.5 μm or less and about 94% water.

(I) About 6% of "Novalon AG300" (particle size 0.2 to 0.5 .mu.m) manufactured by Toagosei Kagaku Kogyo Co., Ltd., in which zirconic acid-based carrier fine particles are substituted with silver ions, etc. An inorganic antibacterial agent aqueous dispersion having the following composition.

<Formation of Inorganic Antibacterial Agent-Supporting Layer for Resin Molded Article> These inorganic antibacterial agent aqueous dispersions are heated to 50 to 60 ° C. and separately molded therein to obtain a resin molded article. The grip of an example hanging leather was dipped and maintained for about 20 minutes.
Then, the holding part of the hanging leather was taken out, washed with water at room temperature, and then dried at room temperature to about 40 ° C.

As a result, a supporting layer of inorganic antibacterial agent fine particles was formed on the entire surface of the holding part of the hanging leather by permeation and fixing of the antibacterial agent dispersion, and the thickness of the supporting layer reached several μm.

<Method and Results of Antibacterial Test> In order to evaluate the antibacterial property of the antibacterial resin molded product produced above, a test piece (30 mm × 30 mm) was produced according to the above. E. coli (Escherichia coli -IFO 12734) cultivated in liquid culture at 28 ° C for 24 hours was used as a test bacterium, and a test was conducted by the drop method using sterile physiological saline as a medium. That is, place a silicone ring on the surface of each sample, add 1 ml of the bacterial solution, and leave at room temperature for 24 hours and 48 hours.
After standing for a period of time, the viable cell count was measured according to the viable cell count measuring method.
The test results are shown in Table 1.

[0039]Table 1                             After leaving for 24 hours  After standing for 48 hours               Viable count Viable count and mortality Viable count and mortality (Unit / ml) (Unit / ml) (%) (Unit / ml) (%)   Untreated area 3.7 × 10^Five      3.6 x 10^Five     2.70 2.2 x 10^Five    40.54   Example 1 3.7 × 10^Five      2.7 x 10¹    99.99 0 100   Example 2 3.7 × 10^Five      1.2 x 10¹   100 0 100   Example 3 3.7 × 10^Five      3.5 x 10¹    99.99 0 100   Example 4 3.7 × 10^Five      4.8 x 10¹    99.99 0 100   Example 5 3.7 × 10^Five      2.3 x 10¹    99.99 0 100   Example 6 3.7 × 10^Five      3.9 x 10¹    99.99 0 100   Example 7 3.7 × 10^Five      6.2 x 10¹    99.98 0 100   Example 8 3.7 × 10^Five      4.6 x 10¹    99.99 0 100Example 9 3.7 × 10 ^Five 1.8 x 10 ¹ 100 0 100

The antibacterial hanging leather grips obtained in each of the above examples showed almost no decrease in antibacterial activity even after repeated washing with water. Since the actual use condition is not to use under washing with water, the antibacterial hanging leather grip portion can withstand use almost semipermanently, and is highly practical.

[0041] To increase the thickness of Example 10 to 18 further antimicrobial carrying layer, the following experiment was performed. That is, about 6% of fine particles having a particle size of 0.5 μm or less and 94% of water in which an antibacterial metal is supported on inorganic carrier fine particles.
An inorganic antibacterial agent aqueous dispersion having the same composition as the above (A) to (I) was prepared.

These inorganic antibacterial agent aqueous dispersions are added to 50-
It was heated to 60 ° C., and a resin-made hanging leather grip portion obtained by separately molding was immersed therein and maintained for about 20 minutes. Then, the hanging leather gripping portion was kept immersed for about 20 minutes under a reduced pressure condition of about 100 Torr or less, or for about 20 minutes under a pressure of about 2 atm. After that, it was washed with water and dried in the same manner as in Examples 1 to 9.

At this time, the thickness of the impregnating / fixing layer of the inorganic antibacterial agent reached several tens of μm, which was satisfactory without falling off even after repeated washing with water.

Further, an antibacterial test of the antibacterial hanging leather grip portion produced above was carried out in the same manner as in Examples 1 to 9, and the mortality rate after 24 hours and 48 hours was 1 in both cases.
It was 00%.

Examples 19 to 27 The following experiments were conducted to stabilize the aqueous dispersions of antibacterial agents. That is, about 6% of fine particles having a particle size of 0.5 μm or less (fine particles of (A) to (I) in Examples 1 to 9) in which an antibacterial metal is supported on inorganic carrier fine particles, polyoxyethylene alkyl-based surfactant 2-5%, polyoxyethylene sorbitan surfactant 2-5%, polyoxyethylene perfluoroalkyl surfactant 0.1-2%, stabilizer 1
%, Fixing agent 1%, water 88-80%, an inorganic antibacterial agent aqueous dispersion liquid was prepared, and impregnation operation under reduced pressure condition or pressurized condition was carried out in the same manner as in Examples 10-18. went.

At this time, the thickness of the impregnating / fixing layer of the inorganic antibacterial agent reached several tens of μm, which was satisfactory without falling off even after repeated washing with water.

Further, an antibacterial test of the antibacterial hanging leather grip portion produced as described above was carried out in the same manner as in Examples 1 to 9, and the mortality rate after 24 hours and 48 hours was 1 in both cases.
It was 00%.

[0048]

According to the present invention, it is possible to impart excellent antibacterial properties to a resin molded product used for the purpose of being touched by an unspecified number of people, such as a grip of hanging leather. The obtained antibacterial resin molded product is tasteless, odorless and nontoxic, has high safety, and its effect lasts semipermanently.

The antibacterial resin molded product is no different from the untreated resin molded product in terms of appearance, feel, size, mechanical strength, odorlessness and the like.

The present invention can be used for resin molded articles of any shape, and since the processing quantity is not limited, the utility value is high.

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Claims (6)

(57) [Claims] 1. A resin molded product comprising an inorganic antibacterial agent dispersion and a pressure reducing line.
An antibacterial characterized by forming an inorganic antibacterial agent-supporting layer by permeating an inorganic antibacterial agent dispersion liquid on the surface of the resin molded product by performing water washing and drying after contacting under conditions or under pressure conditions. Method for making flexible resin moldings. 2. A process of claim 1 the particle size of the inorganic antibacterial agent in an inorganic antibacterial agent dispersion is 1μm or less. 3. The method for producing an antibacterial resin molded product according to claim 1, wherein the resin molded product and the inorganic antibacterial agent dispersion are brought into contact with each other under heating conditions. 4. The production method according to claim 1, wherein the resin molded product is used for an application in which an unspecified number of people touch it. 5. A contract in which the resin molded product (1) is a holding portion for hanging leather.
The production method according to claim 4 . 6. The inorganic antibacterial agent, process of Claim 1 in the inorganic particles or inorganic ion exchanger particles are those obtained by supporting an antibacterial metal.