JPH0753770A - Method for producing antibacterial thermoplastic resin molding - Google Patents

Abstract

(57) [Summary] [Object] To provide a method for efficiently producing a thermoplastic resin molded article which contains a specific phosphate-based inorganic antibacterial agent and can exhibit excellent antibacterial properties. [Structure] Ag _a Na _b Zr ₂ (PO ₄ ) ₃ (a + b =
30% by weight of inorganic filler consisting of inorganic antibacterial agent such as 1)
The granular material formed by molding the thermoplastic resin (A) having a weight average molecular weight of 10,000 or more contained above is blended with the thermoplastic resin (B) which is the same as or different from the thermoplastic resin (A), and molded. To do.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing an antibacterial thermoplastic resin molded product made of a thermoplastic resin containing a specific inorganic antibacterial agent. More specifically, the present invention relates to a method for producing an antibacterial thermoplastic resin molded product that exhibits extremely little discoloration over time during processing, storage and use, and that exhibits a stable antibacterial effect. It can be used as various plastic products that require anti-algal properties and antibacterial properties.

[0002]

2. Description of the Related Art Conventionally, as an inorganic antibacterial agent, one having an antibacterial metal such as silver or copper supported on activated carbon, apatite or zeolite has been known. These are more safe than organic antibacterial agents, have a long lasting antibacterial effect because they do not volatilize or decompose, and have excellent heat resistance. Therefore, an antibacterial resin composition is prepared by mixing these antibacterial agents and various polymer compounds, and the composition is processed into fibrous, film-shaped or various shaped molded articles, and used for various purposes. . However, in general, an antibacterial resin composition comprising an inorganic antibacterial agent and a resin is discolored at the time of storage, use or processing, and not only a change in appearance but also a qualitative change in the resin itself,
There is a problem that the resin is often deteriorated.

In order to solve these problems, a specific phosphate compound has been proposed (JP-A-3-8390).
5, JP-A-3-83906). The antibacterial agent consisting of the specific phosphate compound described in the above-mentioned Japanese Patent Laid-Open can be sustained for a long time by mixing with various polymers, and further, during processing, during storage or use. Even when the resin composition is discolored or deteriorated.

However, the antibacterial resin composition to which the above-mentioned inorganic antibacterial agent composed of the specific phosphate compound is added is molded into a shape having a relatively large specific surface area such as a film or a fibrous material. Since it is highly likely that the inorganic antibacterial agent particles will be exposed on the surface of the resin molded product, it is sufficient to add about 1% by weight of the inorganic antibacterial agent to the resin composition and mold by a known method to obtain a sufficient antibacterial effect. Although it is exhibited, in a general resin molded body having a shape that is bulky and has a relatively small specific surface area obtained by injection molding, extrusion molding, etc., an inorganic antibacterial agent is directly added to the molding resin, or When a masterbatch is prepared by mixing an inorganic antibacterial agent with an appropriate resin in advance and molding is carried out by a known method such as mixing with a molding resin, the antibacterial agent is found on the surface of the resin molding. Without the anti-bacterial There is a problem that it is impossible to sufficiently exhibit the effects, its improvement is desired.

The above-mentioned problems are not limited to the injection-molded product or the extrusion-molded product, but the same tendency is observed in the thick fiber or thick film even in the fibrous or film form.

On the other hand, by mixing an inorganic antibacterial agent with waxes, and coating the inorganic antibacterial agent with the waxes melted by heat or / and heating generated by the mixing, a master for resin of inorganic antibacterial agent particles is obtained. -A method has been proposed in which a stable antibacterial activity is obtained by obtaining a batch and kneading it with a molding resin (JP-A-3-215527). However, in this method, since waxes having a lower melting point than the molding resin are used, when molding with a general apparatus such as an injection molding machine, a molded product obtained by uniformly mixing the molding resin and the waxes. There is a problem that it is difficult to obtain.

[0007]

DISCLOSURE OF THE INVENTION The present invention is a method for efficiently producing a thermoplastic resin molded article containing a specific phosphate-based inorganic antibacterial agent and capable of exhibiting excellent antibacterial properties. The challenge is to provide.

[0008]

[M ¹ is silver, copper, zinc, tin, mercury, lead, iron, cobalt,
At least one metal ion selected from nickel, manganese, arsenic, antimony, bismuth, barium, cadmium and chromium (the valence of which is 1), A
Is at least one kind of ion selected from an alkali metal ion, an alkaline earth metal ion, an ammonium ion and a hydrogen ion (the valence of which is m), M ² is a tetravalent metal, and a and b are both Is a positive number that satisfies la + mb = 1, and n is a number that satisfies 0 ≦ n ≦ 6. ]

The present invention will be described in detail below. ○ Inorganic Filler The inorganic filler in the present invention comprises a specific inorganic antibacterial agent described in detail below, and its fine powder is most suitable.

The inorganic filler in the present invention comprises an inorganic antibacterial agent or other inorganic substances, and the preferable content of the inorganic antibacterial agent is 20 wt% or more, more preferably 40 wt% or more. When the content of the inorganic antibacterial agent in the inorganic filler is low, a large amount of the inorganic filler is required to be mixed with the thermoplastic resin (B) in order to exert a predetermined antibacterial property on the resin molded body, As a result, the characteristics of the thermoplastic resin (B) may be impaired, which is not preferable. When using an inorganic filler containing a component other than the inorganic antibacterial agent, a method of mixing the inorganic antibacterial agent and other components to prepare an inorganic filler containing the inorganic antibacterial agent in advance, or a granular material There is a method of simultaneously mixing the thermoplastic resin (A), a component other than the inorganic antibacterial agent and the inorganic antibacterial agent when molding, and there is no limitation on the mixing order of the inorganic antibacterial agent and the other components. .

Inorganic antibacterial agent The inorganic antibacterial agent in the present invention is a compound represented by the following general formula. M ¹ _{a Ab} M ² ₂ (PO ₄ ) ₃ · nH ₂ O [1] (M ¹ is silver, copper, zinc, tin, mercury, lead, iron, cobalt,
At least one metal ion selected from nickel, manganese, arsenic, antimony, bismuth, barium, cadmium or chromium (the valence of which is 1), A
Is at least one ion selected from an alkali metal ion, an alkaline earth metal ion, an ammonium ion or a hydrogen ion (the valence of which is m), M ² is a tetravalent metal, and n is 0 ≦ n. Is a number that satisfies ≦ 6, and a
And b are positive numbers that satisfy la + mb = 1. )

The compound represented by the above general formula [1] is an amorphous compound or a crystalline compound belonging to the space group R3C, and each of the constituent ions forms a three-dimensional network structure. As the phosphate compound used in the present invention, a crystalline compound having a three-dimensional network structure is preferable because it is less discolored when exposed to sunlight. The above general formula [1]
M ^{1 in the above} is all known as a metal exhibiting antifungal, antibacterial and antialgal properties. Among them, silver enhances antifungal, antibacterial and antialgal properties in addition to safety. It is particularly effective as a metal that can be used.

A in the above general formula [1] is at least one ion selected from an alkali metal ion, an alkaline earth metal ion, an ammonium ion and a hydrogen ion, and preferred specific examples are lithium, sodium and potassium. There is an alkali metal ion such as, and an alkaline earth metal ion such as magnesium or calcium or a hydrogen ion, and among these, potassium, sodium, ammonium ion and hydrogen ion are preferable ions from the viewpoint of stability of the compound and availability at low cost. Is.

M ² in the above general formula [1] is a tetravalent metal, and preferred specific examples thereof include zirconium, titanium or tin. Considering the safety of the compound, zirconium and titanium are particularly preferred. It is a valent metal.

The following are specific examples of the phosphate compound represented by the general formula [1]. Ag _0.005 Li _0.995 Zr ₂ (PO ₄ ) ₃ Ag _0.01 (NH ₄ ) _0.99 Zr ₂ (PO ₄ ) ₃ Ag _0.05 Na _0.95 Zr ₂ (PO ₄ ) ₃ Ag _0.2 K _0.8 Ti ₂ (PO ₄ ) ₃ Ag _0.1 H _0.9 Zr ₂ (PO ₄ ) ₃ Ag _0.05 H _0.05 Na _0.90 Zr ₂ (PO ₄ ) ₃ Ag _0.05 H _0.55 Na _0.40 Zr ₂ (PO ₄ ) _{3 In} addition, the same charge amount as the amount of silver ion per mol of the compound. And Ag in each of the above equations is Z
There are compounds substituted with n, Mn, Ni, Pb, Hg, Sn, or Cu.

The method for synthesizing the phosphate compound used in the present invention includes a calcination method, a wet method, a hydrothermal method and the like, which can be easily obtained as follows, for example. -Synthesis of network structure phosphate When synthesized by the firing method, compounds containing alkali metal such as lithium carbonate (Li ₂ CO ₃ ) or sodium carbonate (Na ₂ CO ₃ ), zirconium oxide (ZrO ₂ ) etc. Compounds containing zirconium and ammonium dihydrogen phosphate (NH ₄ H
₂ PO ₄ ) and other compounds having a phosphoric acid group are mixed in a molar ratio of about 1: 4: 6, and the mixture is calcined at 1100-1400 ° C. to give a compound represented by the general formula [2] A ′. _x Zr ₂ (PO ₄ ) ₃ [2] (A ′ is at least one metal ion selected from an alkali metal ion, an alkaline earth metal ion or an ammonium ion, and x is when A ′ is monovalent. 1 and 1/2 when A is divalent). The compound represented by the general formula [1] is obtained by immersing this in an aqueous solution containing silver ions at an appropriate concentration at room temperature to 100 ° C. In addition, the compound whose A ion in General formula [1] is a hydrogen ion is the compound represented by the said General formula [2] from room temperature to 100.
By dipping in an aqueous solution of an inorganic acid such as nitric acid, sulfuric acid and hydrochloric acid at ℃, the general formula H _{(1-z) A'z} M ₂ (P
A compound [3] represented by O ₄ ) ₃ (z is 0 or a number less than 1) is obtained, and further immersed in an aqueous solution containing silver ions at an appropriate concentration to give a compound represented by the general formula [1]. The compound shown is obtained.

When synthesizing by a wet method, oxalic acid and phosphoric acid are added to the zirconium oxychloride aqueous solution while stirring. The pH of the reaction solution was adjusted to 3 with a caustic soda solution, heated under reflux for 10 hours,
The precipitate is filtered, washed with water, dried and pulverized to obtain reticulated zirconium phosphate [NaZr ₂ (PO ₄ ) ₃ ]. The compound represented by the general formula [1] is obtained by immersing this in an aqueous solution containing an antibacterial metal at an appropriate concentration.

In order to obtain an antibacterial agent having excellent antibacterial properties and weather resistance, hydrogen ions are supported together with the antibacterial metal ions as the tetravalent metal phosphate represented by the general formula [1]. It is preferable to prepare the above compound and further calcinate it. When the tetravalent metal phosphate salt has an ammonium ion, the ammonium ion is thermally decomposed by baking to leave a hydrogen ion, so that the tetravalent metal phosphate salt does not need to carry the hydrogen ion. On the other hand, when the tetravalent metal phosphate has no or only a very small amount of ammonium ion, a method of allowing the tetravalent metal phosphate to carry hydrogen ions is to immerse it in an acidic solution.
Preferred specific examples of the acidic solution include aqueous solutions of hydrochloric acid, sulfuric acid, nitric acid and the like. The acid concentration, temperature, and immersion time of the acidic solution are not particularly limited, but in general, the higher the acid concentration, the more quickly hydrogen ions can be supported, so the preferred acid concentration is 0.1 N or more, and The treatment temperature is 40 ° C. or higher, more preferably 60 ° C. to 100 ° C., and the immersion time is 10 minutes or longer, more preferably 60 minutes or longer.

The calcination step may be carried out after supporting the antibacterial metal ion and hydrogen ion or ammonium ion on the tetravalent metal phosphate to improve the chemical and physical stability of the antibacterial agent and discolor it. It is preferable in order to obtain an antibacterial agent with a high degree of prevention. Further, due to this baking step, the water adhering to the antibacterial agent is almost absent, so that the processability into resin is also improved. Baking temperature is 500-1300
C, preferably 600 to 1000 C, more preferably 7
It is good to bake at 00 to 900 ° C. If it is baked at a temperature lower than 500 ° C, it is insufficient to improve the chemical and physical stability of the antibacterial agent, and if it is baked at 1300 ° C or higher, the antibacterial property is lowered, or fine particles of tetravalent metal phosphate are used. There is a possibility that salt may be fused and a fine particle antibacterial agent may not be obtained. The firing time is not particularly limited, and a sufficient effect is usually obtained by firing for 1 to 20 hours. The rate of temperature increase and the rate of temperature decrease are not particularly limited, and can be appropriately adjusted in consideration of the capacity and productivity of the firing furnace.

In order to exert antifungal, antibacterial and antialgal properties, the larger the value of a in the general formula [1] is, the better.
When the value of a is 0.001 or more, it is possible to sufficiently exhibit antifungal properties and antibacterial properties and antialgal properties. However, if the value of a is less than 0.001, it may be difficult to exert the antifungal, antibacterial and antialgal properties for a long time. Therefore, the value of a is set to 0.01 or more. It is preferable.
In consideration of economy, the value of a is preferably 0.5 or less.

The phosphates used in the present invention are stable to heat and light exposure and have a temperature of 500 ° C. and in some cases 800
Even after heating at 1 ° C to 1100 ° C, the structure and composition do not change at all, and no color change occurs even when irradiated with ultraviolet rays. Further, the phosphate used in the present invention does not come into contact with water in a liquid state, and the skeleton structure is not changed even in an acidic solution. Therefore, processing and storage when obtaining various molded products, as well as conventional antibacterial agents, during use,
It is not restricted by heating temperature or light shielding conditions.

In the inorganic filler, preferred specific examples of the components other than the above-mentioned specific inorganic antibacterial agent include carbonates such as carbon, calcium carbonate and magnesium carbonate,
Sulfates such as barium sulfate, iron oxides, aluminum oxides, oxides such as titanium oxide, magnesium oxide, zinc oxide and silica, metals such as aluminum, gold, iron, zinc and tin, and hydroxides such as aluminum hydroxide and slaked lime. Substances, kaolinite, kaolin, mica, zeolite, diatomaceous earth, clay such as sericite and halloysite, basic magnesium, silicate and the like. All of these components are additives for resins, and are known as pigments, structure reinforcing materials, flame retardants, extenders and the like. The fine powder that constitutes the inorganic filler can have various shapes, and specific shapes such as spherical, columnar, disk-like, fibrous, needle-like, whisker-like, and balloon (hollow particle) -like are available. There is.

Thermoplastic resin (A) The thermoplastic resin (A) in the present invention is a resin that is mixed in advance with an inorganic filler to form a granular material, and is a natural resin, a synthetic resin or a semi-resin. It may be any of synthetic resins. Preferred specific examples are polypropylene, polyethylene, poly-4-methylpentene-1, polystyrene, polyvinyl chloride, polyvinylidene chloride, ABS resin, AS resin, methacrylic resin, polyamide, polyvinyl alcohol, EVA, and cellulose series. Examples include plastics, cellulose acetate, polyester, polycarbonate, and silicone resin. In order to efficiently obtain a granular material that is a molded product of an inorganic filler and a thermoplastic resin (A), the thermoplastic resin (A) needs to have a weight average molecular weight of 10,000 or more as measured by a viscosity method. This molecular weight is
When it is less than 10,000, a molded product obtained by uniformly mixing the thermoplastic resin (A) and the thermoplastic resin (B) cannot be efficiently obtained in the molding step. Thermoplastic resin (A)
May be the same as or different from the resin (abbreviated as the thermoplastic resin (B)) forming the molded body. When the same kind of thermoplastic resin (A) as the thermoplastic resin (B) is used, there is a characteristic that the physical properties peculiar to the thermoplastic resin (B) are not impaired. On the other hand, unlike the thermoplastic resin (B),
If the thermoplastic resin (A) having poor compatibility with the thermoplastic resin (B) is used, the thermoplastic resin (A) tends to appear on the surface of the resin molded body, resulting in the antibacterial property of the resin molded body. Can be increased. The thermoplastic resin (A) in the present invention is not particularly limited, but one having a high melt index flow tends to enhance the antibacterial property of the resin molded product according to the present invention, and therefore, as the thermoplastic resin (A), It is preferable to use a resin having a higher melt index flow than the thermoplastic resin (B).

Thermoplastic resin (B) The thermoplastic resin (B) in the present invention is mixed with a granular material which is a molded product of an inorganic filler and a thermoplastic resin (A) to form a molded product of the present invention. It is a resin compounded for molding. The types of resins that can be used in the present invention are
It is the same as the thermoplastic resin (A).

The thermoplastic resin (B) is not limited to a single resin, and may be blended with other resin or rubber. Further, various other additives may be mixed as necessary in order to adjust the physical properties of the thermoplastic resin (B). Preferable specific examples include pigments, dyes, antioxidants, light stabilizers, flame retardants, antistatic agents, foaming agents, impact resistance enhancers, glass fibers, moistureproofing agents and extenders. In addition to the inorganic antibacterial agent, an organic antibacterial / antifungal agent may be added separately to increase the immediate antibacterial effect and increase the effect. A preferred blending ratio of these additives is up to 10 parts per 100 parts by weight of the thermoplastic resin (B) (hereinafter simply referred to as "part").

Molding Method of Granules In the method of the present invention, first, an inorganic filler containing an inorganic antibacterial agent is mixed with a thermoplastic resin (A) in a specific ratio, and the mixture is granulated by a known molding method. Mold.

Mixing and Molding of Inorganic Filler and Thermoplastic Resin (A) Any known method can be adopted as a mixing method and a molding method of the inorganic filler and the thermoplastic resin (A). For example,
A method of mixing the powdery or pelletized thermoplastic resin (A) and the inorganic filler with a Henschel mixer, and then molding the mixture into granules by an extrusion molding machine, the inorganic filler and the thermoplastic resin (A) After mixing with a powder and granulating, and a method of heating and melting the thermoplastic resin (A), adding an inorganic filler to the liquefied mixture, mixing and then solidifying by cooling and granulating Etc. Further, in mixing these, a known dispersant may be further added in an appropriate amount, for example, an inorganic filler and a dispersant are mixed, and the granulated product is mixed with the thermoplastic resin (A) to be granulated. There is a way to do it.

Blending ratio of the inorganic filler in the granular material The blending ratio of the inorganic filler in the granular material is 100
It is 30 parts or more and preferably 70 parts or less per part. If the amount of the inorganic filler is less than 30 parts, it is difficult to obtain a resin molded product having excellent antibacterial properties. On the other hand, it is not easy to obtain a granular material containing more than 70 parts of the inorganic filler by a usual method. Therefore, considering the above-mentioned content of the inorganic antibacterial agent in the inorganic filler, the preferable mixing ratio of the inorganic antibacterial agent in the granular material is 6 to 70% by weight.

Shape and Size of Granular Material The shape of the granular material obtained as described above is not particularly limited, and specific shapes include a spherical shape, a prismatic shape, a cylindrical shape, and a disk shape. Further, in order to obtain a molded product that is uniformly mixed with the thermoplastic resin (B), it is desirable that the granular material and the thermoplastic resin (B) have similar shapes and sizes, and Is most preferably a cylindrical pellet having a size of 1 to 5 mm and a diameter and length within this range.

Preparation Method of Molded Body The antibacterial thermoplastic resin molded body is mixed at a suitable temperature and pressure according to the characteristics of the granular material and the thermoplastic resin (B),
It can be easily prepared by a method of mixing or kneading, and the specific operation thereof may be carried out by an ordinary method, and it can be molded into various forms. Examples of specific molding methods include extrusion molding, injection molding, calendar processing,
There are vacuum forming and foam forming, and all known processing techniques and machines can be used.

Concentration of Inorganic Antibacterial Agent in Molded Article The preferred concentration of the inorganic antibacterial agent is 0.01 to 10 parts per 100 parts of the molded article. If it is less than 0.01 part, it may be difficult to exert sufficient antibacterial properties on the molded product, and if it is added in excess of 10 parts, the antibacterial property is not significantly improved. May make things worse.

○ Mixing Ratio of Granular Material when Forming Molded Article A preferable mixing ratio of the particulate material to the thermoplastic resin (B) when manufacturing the molded article is that the content ratio of the inorganic antibacterial agent in the molded article is the above. The above range may be appropriately determined based on the blending ratio of the inorganic antibacterial agent in the granular material. still,
When the thermoplastic resin (A) and the thermoplastic resin (B) are different and their mutual compatibility is poor, the molded product may become non-uniform. In such a case, the mixing ratio of the granular material should be
20 parts or less, more preferably 10 parts per 100 parts of the molded body
It is better to make less than a part

Any known method can be adopted as a method for compounding the granular material into the thermoplastic resin (B) and for molding the compound. When the powdery thermoplastic resin (B) is used, molding may be difficult and a sufficient antibacterial effect may not be obtained. Therefore, the thermoplastic resin (B) is used in the present invention. It is preferable to mix and mold as a pellet-shaped molded product in the same manner as the granular product in.

The antibacterial resin molded product thus obtained is excellent in safety and processability because the inorganic antibacterial agent as a component thereof has excellent chemical and physical stability. . Moreover, it does not deteriorate during mixing of the antibacterial agent and the resin, and during storage or subsequent use of the antibacterial resin composition, and has antifungal, antibacterial and antialgal properties for a long time even in a severe environment. .

Uses The antibacterial thermoplastic resin molded product obtained by the present invention is effective in various fields in which a resin molded product having antifungal, antialgal and antibacterial properties is required. Specific applications include, for example, refrigerators, vacuum cleaners, washing machines, electric fans, and VTs for light electric appliances.
R, TV, tape recorders, OA equipment, vehicle interiors and exteriors, telephones, sundries related housing parts, various containers, sporting goods, daily necessities, kitchen utensils, bathroom equipment, building materials, optical equipment , Stationery, textiles, water treatment products and the like.

Hereinafter, the present invention will be described more specifically by way of examples.

【Example】

Reference Example 1 (Preparation of antibacterial agent) An aqueous solution of zirconium sulfate and an aqueous solution of phosphoric acid were mixed at a molar ratio of zirconium and phosphorus of 2: 3 to form a precipitate, and an aqueous solution of sodium hydroxide was used. After adjusting the pH to 2, 130 under hydrothermal conditions
By heating at 12 ° C. for 12 hours, crystalline zirconium phosphate [NaZr ₂ (PO ₄ ) ₃ ] was obtained. The phosphate compound obtained above was thoroughly washed with water, added to silver nitrate and a 1N aqueous nitric acid solution, stirred at 60 ° C. for 4 hours, washed thoroughly with water and dried. This was baked in a baking furnace at 750 ° C for 4 hours and then lightly crushed to give the antibacterial agent Ag _0.17 Na.
_0.29 H _0.54 Zr ₂ (PO ₄ ) ₃ was obtained. The antimicrobial agent obtained is a white powder with an average particle size of 0.72 micron.

Example 1 (Preparation of antibacterial PP resin molding) The antibacterial agent prepared in Reference Example 1 and low density polyethylene (SHOREX M221 manufactured by Showa Denko KK) were used.
The antibacterial agent was mixed at a ratio of 33.3 parts per 100 parts by weight of the total weight of the antibacterial agent and the low-density polyethylene, and a granular material (a cylinder having a diameter of about 2 mm and a length of about 3 mm) was molded by a uniaxial extruder. This granular material was mixed with polypropylene resin (trade name: polypropylene MB240 manufactured by Tokuyama Soda Co., Ltd.) at a ratio of 6 parts of granular material per 100 parts of the total amount of the mixture, which was then injection molding machine manufactured by Meiki Seisakusho Co., Ltd. M-50
Injection molding at a molding temperature of 200 ° C. using AII-DM,
A plate of 11 cm × 11 cm × 2 mm was prepared (Sample No. 1).

Example 2 (Preparation of antibacterial PP resin molded product) A high density polyethylene (Ace Polymer 5003BH manufactured by Showa Denko KK) was used in place of the low density polyethylene in the granular material of Example 1. A plate was prepared in the same manner as in Example 1 (Sample No. 2).

Example 3 (Preparation of antibacterial high-density polyethylene resin molded product) The antibacterial agent prepared in Reference Example 1 and low-density polyethylene (SHOREX M221 manufactured by Showa Denko KK) were used as an antibacterial agent and low-density polyethylene. The antibacterial agent was mixed at a ratio of 50 parts per 100 parts of the total weight, and a granular material (a cylinder having a diameter of about 2 mm and a length of about 3 mm) was molded by a uniaxial extruder. This granular material was mixed with high-density polyethylene resin (Ace Polymer 5003BH manufactured by Showa Denko KK) at a ratio of 4 parts of the total amount of 100 parts of the mixture, and injection molding machine manufactured by Meiki Seisakusho Co., Ltd. Injection-molded using M-50AII-DM at a molding temperature of 200 ° C., 11 cm × 11
A cm × 2 mm plate was prepared (Sample No. 3).

Example 4 (Preparation of antibacterial high-density polyethylene resin molded product) Instead of 50 parts of the antibacterial agent in Example 3, 25 parts of the antibacterial agent prepared in Reference Example 1 and 25 parts of calcium carbonate were used. A plate was prepared in the same manner as in Example 3 except that the mixing ratio was changed to 8 parts instead of 4 parts (Sample No. 4).

Example 5 (Antibacterial Low Density Polyethylene Resin) A plate was prepared in the same manner as in Example 1 except that the polypropylene compounded in the granular material was replaced with low density polyethylene (Sample No. 5).

Example 6 (Antibacterial Low Density Polyethylene Resin) A plate was prepared in the same manner as in Example 2 except that the polypropylene compounded in the granular material in Example 2 was replaced with low density polyethylene (Sample No. 6).

Example 7 (Preparation of antibacterial high-density polyethylene resin molding) Instead of the antibacterial agent of 50 parts in Example 3, 25 parts of the antibacterial agent prepared in Reference Example 1 and titanium oxide (Ishihara Sangyo Co., Ltd.) Using a mixture of 25 parts of company name CR-80), the mixing ratio of the granules was changed to 4 parts to 2 parts, and the high density polyethylene resin was replaced with ABS resin (product of Denki Kagaku Kogyo Co., Ltd.). A plate was prepared in the same manner as in Example 3 except that the name: GT-R-10) was used (Sample No.
7).

Comparative Example (Preparation of Antibacterial High Density Polyethylene Molded Product) For comparison, a plate containing only polypropylene resin was prepared without mixing an antibacterial agent (Sample No. 8).

Test Example (Antibacterial Evaluation Method) The antibacterial activity of the plates prepared in Examples 1 to 7 and Comparative Example was evaluated by the following method. Escherichia coli was used as the test bacteria, the plate was cut into 3 cm × 3 cm, and the bacterial solution was uniformly inoculated on the surface so that the number of bacteria per plate was 10 ⁴ to 10 ⁵ , and the temperature was 27 ° C. Saved in. After storing for 3 hours, the surviving bacteria on the test piece were washed out with a medium for measuring the number of bacteria (SCDLP liquid medium), and this washing solution was used as a test solution. The viable cell count of this test solution was measured by the pour plate culture method (37 ° C. for 2 days) using a cell count medium. The results of the antibacterial test obtained as described above are shown in Table 1 (unit is cells / ml). In addition, with these test results,
The number of bacteria in the bacterial solution used in each test (initial number of bacteria) and the number of control bacteria (the number of bacteria after storing the bacterial solution in a petri dish at 27 ° C. for 3 hours) are also shown (units are all / ml).

[0046]

[Table 1]

[0047]

INDUSTRIAL APPLICABILITY According to the present invention, an antibacterial thermoplastic resin molding exhibiting a high antibacterial effect can be efficiently obtained.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Hideki Kato 1-1 Funami-cho, Minato-ku, Nagoya-shi, Aichi Toagosei Chemical Industry Co., Ltd. Nagoya Research Institute (72) Inventor Manabu Tanase Port, Nagoya-shi, Aichi 74 Aron Kasei Co., Ltd. Technical Research Laboratory at 1 Funami-cho, Tokyo (72) Inventor Masa Hasegawa 74 Aron Kasei Co., Ltd. Technical Research Laboratory at 1 Funami-cho, Minato-ku, Nagoya, Aichi Prefecture

Claims (1)

[Claims] 1. A thermoplastic resin (A) having a weight average molecular weight of 10,000 or more containing 30% by weight or more of an inorganic filler composed of an inorganic antibacterial agent represented by the following general formula [1] is molded. And a thermoplastic resin (B) which is the same as or different from the thermoplastic resin (A), and is molded. [However, the thermoplastic resin (A) is a polyolefin resin, and the thermoplastic resin (B) is an ABS resin,
Moreover, the above-mentioned manufacturing method in which all of the inorganic fillers are the inorganic antibacterial agents is excluded. ] M ¹ _{a Ab} M ² ₂ (PO ₄ ) ₃ · nH ₂ O [1] [M ¹ is silver, copper, zinc, tin, mercury, lead, iron, cobalt,
At least one metal ion selected from nickel, manganese, arsenic, antimony, bismuth, barium, cadmium and chromium (the valence of which is 1), A
Is at least one kind of ion selected from an alkali metal ion, an alkaline earth metal ion, an ammonium ion and a hydrogen ion (the valence of which is m), M ² is a tetravalent metal, and a and b are both Is a positive number that satisfies la + mb = 1, and n is a number that satisfies 0 ≦ n ≦ 6. ]