JPH09302184A - Antimicrobial vinyl chloride resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an antimicrobial vinyl chloride resin composition which can surely develop the antimicrobial activity that the microbial agent intrinsically has and shows excellent thermal stability during the processing by adding an organotin compound, a silver-containing inorganic antimicrobial agent and less than a specific amount of a sulfur-containing organotin compound to a vinyl chloride resin. SOLUTION: This antimicrobial vinyl chloride resin composition comprises (A) a vinyl chloride resin, (B) an organotin compound as a stabilizer and (C) a silver-containing inorganic antimicrobial agent, for example, a phosphate salt antimicrobial agent represented by the formula: Aga Ab M2 (PO4 )3 .nH2 O [A is an alkali or alkaline earth metal ion, ammonium ion, hydrogen ion; M is a tetravalent metal ion; n is 0-6; a and b are positive numbers satisfying the relation of the formula: a+bm=1 (m is the valence number of A) in which sulfur-containing organotin compound is contained in an amount of 1 or less pt.wt. per 100 pts.wt. of this composition.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to an antibacterial vinyl chloride resin composition having excellent antibacterial properties. From the composition of the present invention, it is possible to easily obtain an antibacterial vinyl chloride resin molded product exhibiting an excellent antibacterial effect, and this molded product is useful as various plastic products which require antifungal, antialgal or antibacterial properties. Is.

[0002]

2. Description of the Related Art Conventionally, activated carbon has been used as an inorganic antibacterial agent.
It is known that apatite or zeolite is supported with silver ions. These are more safe than organic antibacterial agents, have a long lasting antibacterial effect because they do not volatilize and 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-like or pellet-like forms and used for various purposes.

Further, a specific phosphate compound has been proposed as an inorganic antibacterial agent (Japanese Patent Laid-Open No. 3-83905), and this antibacterial agent is mixed with various polymers to have an antibacterial effect for a long time. A resin composition and a molded article thereof that last can be easily obtained, and these resin composition and a molded article thereof have the feature that they do not undergo discoloration or deterioration during preparation, storage or use. are doing.

On the other hand, it is known to use an organotin compound as a stabilizer for a vinyl chloride resin, and a stabilizer composed of an organotin compound is used particularly in applications such as food-related applications where toxicity to the human body must be eliminated. It is widely used as an extremely effective ingredient.

However, when a vinyl chloride resin containing a stabilizer composed of an organotin compound is mixed with a silver-based inorganic antibacterial agent and molded, the resin molded product has excellent antibacterial properties originally possessed by the silver-based inorganic antibacterial agent. There is a problem that it may not be able to be exerted, and its improvement is desired.

[0006]

SUMMARY OF THE INVENTION The present invention is applicable not only to a vinyl chloride resin containing a stabilizer composed of an organic tin compound containing a silver-based inorganic antibacterial agent, but also to a molded article formed by molding the same. Also, it is an object of the present invention to provide an antibacterial vinyl chloride resin composition capable of reliably exhibiting the original excellent antibacterial properties of a silver-based inorganic antibacterial agent and having excellent thermal stability during processing. Is.

[0007]

Means for Solving the Problems As a result of intensive studies to solve the above problems, the present inventors have blended a silver-based inorganic antibacterial agent into a vinyl chloride resin containing a stabilizer composed of an organotin compound. In the antibacterial vinyl chloride resin composition, it is extremely effective to keep the content ratio of the sulfur-containing organic tin compound at a specific concentration or less, which allows the properties of the silver-based inorganic antibacterial agent and the stabilizer to be sufficiently exhibited. The inventors have found that it is possible to obtain a resin molded product having extremely excellent antibacterial properties and excellent thermal stability during processing, and completed the present invention.
That is, the present invention is an antibacterial vinyl chloride resin composition containing a stabilizer composed of an organotin compound, a silver-based inorganic antibacterial agent and a vinyl chloride resin or these three components and a desired additive,
The antibacterial vinyl chloride resin composition is characterized in that the content ratio of the stabilizer comprising a sulfur-containing organic tin compound is 1 part by weight or less per 100 parts by weight of the antibacterial vinyl chloride resin composition.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below. ○ Silver-based inorganic antibacterial agent The silver-based inorganic antibacterial agent in the present invention is an inorganic substance carrying silver ions, and preferred specific examples thereof include zeolite, aluminosilicate, activated carbon and apatite, and zirconium phosphate. Some phosphate-based inorganic ion exchangers carry silver ions. As a preferred antibacterial agent in which a phosphate-based inorganic ion exchanger carries silver ions, there is a phosphate-based antibacterial agent represented by the following formula [1] (hereinafter abbreviated as antibacterial agent [1]). _{Ag a A b M 2 (PO} 4) 3 · nH 2 O (1) (A is an alkali metal ion, alkaline earth metal ions,
At least one ion selected from ammonium ions or hydrogen ions, M is a tetravalent metal ion,
n is a number satisfying 0 ≦ n ≦ 6, and a and b are both positive numbers satisfying a + mb = 1. Here, m is the valence of A. )

When the antibacterial agent [1] is used as the silver-based inorganic antibacterial agent, the antibacterial agent [1] has excellent chemical and physical stability, and therefore most of the antibacterial metal is eluted even in an acidic solution. Since it does not have hygroscopicity, the antibacterial resin composition of the present invention is extremely excellent in processability. In addition, when mixed with a silver-based inorganic antibacterial agent and resin, and without subsequent deterioration during storage or use of the antibacterial resin composition, even under severe conditions such as high temperature, high humidity, and ultraviolet exposure, The antibacterial agent [1] and the vinyl chloride resin are not discolored or deteriorated at all, and the resin composition of the present invention and the molded article thereof have antibacterial, antialgal, and antifungal properties for a long period of time.

The antibacterial agent [1] is a space group.

[0011]

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It is a crystalline compound belonging to the category III, in which each constituent ion forms a three-dimensional network structure. A in the above formula [1] 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. Preferred specific examples thereof include alkali metals such as lithium, sodium and potassium. There are ions, alkaline earth metal ions such as magnesium or calcium, and hydrogen ions, and among these, lithium, sodium, ammonium ions and hydrogen ions are preferable ions in view of the stability of the compound and availability at low cost.

M in the above formula [1] is a tetravalent metal ion, and preferred specific examples thereof are zirconium ion, titanium ion or tin ion. Considering the safety of the compound, zirconium ion and titanium ion are A more preferable and particularly preferable tetravalent metal ion is zirconium ion.

In order to exhibit antifungal, antibacterial and antialgal properties, the larger the value of a in the above formula [1] is, the better.
When the value of is 0.001 or more, it is possible to sufficiently exhibit antifungal properties, antibacterial properties, and antialgal properties. However, if the value of a is less than 0.01, it may be difficult to exert antifungal, antibacterial and antialgal properties for a long time.
The value of is preferably 0.01 or more. Also, in consideration of economy, it is appropriate that the value of a is 0.7 or less.

The silver-based inorganic antibacterial agent in the present invention is usually obtained in the form of powder, and the preferable average particle size is 0.01 to 20 μm.
m, more preferably 0.05 to 5 μm, most preferably 0.1 to 2 μm.

A preferred blending ratio of the silver-based inorganic antibacterial agent is 100 parts by weight (hereinafter, simply referred to as "parts") of the vinyl chloride resin composition of the present invention (including the desired components, if any). (Abbreviated) per 0.01 to 10 parts.
If it is less than 0.01 part, the antibacterial property of the vinyl chloride resin composition is not sufficient, while if it is compounded in an amount of more than 10 parts, the antibacterial property is hardly improved, and the original physical properties of the vinyl chloride resin may be deteriorated. is there.

In the present invention, by using a silver-based inorganic antibacterial agent in combination with a specific metal oxide, the antibacterial properties of the resin composition of the present invention and the resin molded product obtained therefrom can be enhanced, and When the antibacterial agent [1] is used as the inorganic antibacterial agent, the effect of preventing discoloration of the resin can be further enhanced. -Metal oxide A preferable metal oxide that can be used in the present invention is at least one compound selected from zinc oxide and titanium dioxide. Zinc oxide is represented by a chemical formula of ZnO and is also called zinc white, and may be a natural product or a synthetic product. The titanium dioxide may be either a natural product or a synthetic product, and may be either amorphous or crystalline.
Titanium dioxide is classified into anatase, rutile, and brookite according to the crystal system.In the present invention, any crystal system may be used, and anatase and rutile are preferred because they can be easily obtained industrially. Things. There is no particular limitation on the particle size of the metal oxide and the shape of the particles, but in consideration of dispersibility in the resin, the average particle size is preferably 0.01 to 10 μm or less, and the shape of the particles is spherical rather than acicular. preferable. Those generally used as white pigments can be used.

When the silver-based inorganic antibacterial agent and the metal oxide are used in combination, the preferable combination ratio of the metal oxide is 5 to 90% of the metal oxide based on 100 parts by weight of the total of the silver-based inorganic antibacterial agent and the metal oxide. It is a department. If the mixing ratio of the metal oxide is less than 5 parts, it may be difficult to exert the effect of improving the antibacterial activity due to the coexistence of the metal oxide and the silver inorganic antibacterial agent, and the metal oxide is more than 90 parts. Then, it may be difficult to exert the antibacterial effect of the silver inorganic antibacterial agent. The preferable blending ratio of the metal oxide in the vinyl chloride resin composition of the present invention is such that the total weight of the silver-based inorganic antibacterial agent and the metal oxide is 0.01 to 10 parts per 100 parts of the vinyl chloride resin composition. Is. If it is less than 0.01 part, the antibacterial properties of the vinyl chloride resin composition may not be sufficiently obtained, while if it is compounded in more than 10 parts, the antibacterial activity is hardly improved. May decrease. Furthermore, in order to exert a sufficient antibacterial effect, the silver ion concentration is preferably 0.5% by weight or more, preferably 2% by weight or more, based on the total weight of the silver-based inorganic antibacterial agent and the metal oxide. More preferably.

○ Stabilizer The stabilizer in the present invention comprises an organic tin compound. Organotin compounds are known as stabilizers for vinyl chloride resins and are classified into fatty acid salt-based compounds, maleate-based compounds and sulfur-containing compounds. The type of the stabilizer in the present invention is not particularly limited as long as it is an organotin compound, but when it is a sulfur-containing organotin compound, its content ratio is 0 per 100 parts of the antibacterial vinyl chloride resin composition of the present invention. It is necessary to make up to 1 part, preferably 0 to 0.5 part. When preparing a vinyl chloride resin composition in which initial coloring is suppressed, a sulfur-containing organic tin compound is usually added as a stabilizer, but in order to exhibit the original excellent antibacterial properties of the silver-based inorganic antibacterial agent, The use of sulfur-based organotin compounds must be suppressed below the above specified concentration.

The preferred stabilizer in the present invention is an organotin compound represented by the following general formula [2]. R _m SnY _4-m [2] (wherein m is 1 or 2, R is an alkyl group,
When m is 2, they may be the same as or different from each other, and Y is at least one selected from the residue of maleic acid or its ester and the residue of fatty acid. ) Preferred R in the above general formula [2] has 1 to 1 carbon atoms.
5 alkyl group, methyl group, n-butyl group, n-
Octyl and dodecyl groups are particularly preferred.
The stabilizer in the present invention is Y in the general formula [2].
Is a maleic acid or its ester residue, it is an organotin maleate compound, and when Y is a fatty acid residue, it is an organotin fatty acid salt compound. The following compounds are preferable organic tin maleate compounds. That is, dialkyltin maleate polymer represented by the following general formula and di -n- octyl-tin maleate polymer, - ^{[Sn (R 1) (R 2} ) -OOCCH = CHCOO ]
_p − (wherein R ¹ and R ² are alkyl groups which may be the same or different from each other, and p is a positive integer.) Dialkyltin bis (alkyl maleate) represented by the following general formula. Ester) salt

[0021]

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(However, R is an alkyl group, and R ³ and R ⁴ are groups which may be the same or different from each other and are selected from an alkyl group, an alkoxyalkyl group, a benzyl group and a cycloalkyl group. Preferred R ³ and R ⁴
Examples thereof include a butyl group, a 2-ethylhexyl group, an isooctyl group and a cyclohexyl group. ) And bis (dialkyltin maleic acid alkyl ester) maleate represented by the following general formula.

[0023]

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(Wherein R is an alkyl group, and R ⁵ and R ⁶ are the same or different and are selected from an alkyl group, an alkoxyalkyl group, a benzyl group and a cycloalkyl group. Preferred R ⁵ and R ⁶
Examples thereof include a butyl group, a 2-ethylhexyl group, an isooctyl group and a cyclohexyl group. ) Further, the following compounds are preferred as organic tin fatty acid salt compounds. That is,
Examples thereof include dialkyltin dilaurate such as dibutyltin dilaurate, dialkyltin distearate such as dibutyltin distearate, dialkyltin dilaurate such as dimethyltin dilaurate, and dialkyltin distearate such as dimethyltin distearate. As the stabilizer in the present invention, two or more kinds selected from the above-mentioned organic tin maleate compound and organic tin fatty acid salt compound can be used in combination.

The preferred blending ratio of the stabilizer in the present invention is 0.3 to 10 parts, more preferably 0.5 to 5 parts, per 100 parts of vinyl chloride resin. If it is less than 0.3 part, the effect of suppressing the thermal decomposition of the vinyl chloride resin composition may not be sufficiently exerted, while if it is compounded in an amount of more than 10 parts, there is almost no effect of improving the thermal stability. There is a possibility that the original physical properties of the vinyl chloride resin composition may be deteriorated.

Vinyl chloride resin The vinyl chloride resin in the present invention may be either a hard type or a soft type, and a plasticizer may be optionally added. Preferable plasticizers include phthalic acid esters represented by dioctyl phthalate, aliphatic dibasic acid esters, phosphoric acid esters, fatty acid esters, polyhydric alcohol esters, etc. Alternatively, two or more kinds can be used. Further, the vinyl chloride resin in the present invention may be a homopolymer or a copolymer, and may have an arbitrary degree of polymerization depending on the application. Examples of the copolymerizable monomer include vinyl esters such as vinyl acetate, vinyl alcohol, (meth) acrylic acid and α-olefin.
It is also possible to use one or more copolymers. In the resin composition of the present invention, polyolefin, various rubbers (for example, polybutadiene, polyisoprene, polychloroprene, fluororubber, styrene-butadiene rubber, acrylonitrile-butadiene rubber, styrene-butadiene-styrene block copolymer, styrene) -Isoprene-
Styrene block copolymer, styrene-ethylene-butylene-styrene block copolymer, styrene-propylene-butylene-styrene copolymer, etc.) or thermoplastic synthetic resin (for example, polystyrene, styrene-acrylonitrile copolymer, acrylonitrile-butadiene-). A styrene copolymer, polyamide, polyethylene terephthalate, polycarbonate, polyvinyl chloride, fluororesin, etc.), a lubricant, an ultraviolet absorber, and the like can be appropriately blended.

Molding An antibacterial vinyl chloride resin molded product can be easily obtained using the composition of the present invention, and mixing, mixing, kneading, etc. at an appropriate temperature or pressure according to the characteristics of various components to be blended, etc. Can be mixed by the method of. After uniform mixing in this way, it can be formed into various forms using any known processing techniques and machines. Examples of specific molding methods include extrusion molding, injection molding, calendering, vacuum molding and foam molding.

○ Uses The antibacterial vinyl chloride resin molded product molded by using the composition of the present invention requires antibacterial properties, algae-proof and antifungal properties, and various fields in which the vinyl chloride resin molded product is used. Is effective in. Specific applications include, for example, various molded products such as pipes and plates, flooring materials, wall materials, furniture materials, building materials such as pipes and piping covers, films, sheets, synthetic leather, coating materials for electric wires. , For light electrical, mixer, V
There are various containers, sports equipment, daily necessities, kitchenware such as tableware for TR, TV housings, clocks, cameras, stereos, tape recorders, OA equipment, telephones, FAX equipment, etc. For stationery, mechanical pencil, ballpoint pen, eraser,
There are clips, staples, clear cases, etc.

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

【Example】

<Reference Example 1> (Preparation of antibacterial agent) A-type zeolite [composition: 0.94 Na ₂ O.Al ₂ O ₃ .1.
9 SiO ₂ · xH ₂ O] (x = 1 to 4) was added to an aqueous solution of silver nitrate, stirred at room temperature for 10 hours, washed thoroughly with water, and dried at 110 ° C. to obtain an antibacterial zeolite [a] Got The obtained antibacterial agent is a white powder represented by the following composition formula and having an average particle diameter of 2.6 μm. 0.04Ag ₂ O / 0.9Na ₂ O / Al ₂ O ₃ / 1.9SiO ₂ / 2.2H ₂ O [a]

<Reference Example 2> (Preparation of antibacterial agent) An aqueous solution of zirconium sulfate and an aqueous solution of ammonium dihydrogen phosphate were mixed so that the ratio of zirconium to phosphorus was 2: 3 to form a precipitate, After adjusting the pH to 2 using an aqueous solution of sodium hydroxide, crystalline zirconium phosphate was obtained by heating under hydrothermal condition at 150 ° C. for 24 hours. The phosphate compound obtained above was added to an aqueous solution of silver nitrate and stirred at room temperature for 4 hours,
After thoroughly washing with water, drying, and lightly pulverizing, an antibacterial agent [B] represented by the following composition formula and having an Ag content of 11% by weight was obtained. The obtained antibacterial agent has an average particle size of 0.47 μm.
m is a white powder. Ag _0.53 Na _0.13 H _0.34 Zr ₂ (PO ₄ ) ₃ [B]

<Reference Example 3> (Preparation of antibacterial agent) 30 parts of the antibacterial agent [b] and 70 parts of zinc oxide were put in a small pulverizer and mixed to obtain an antibacterial agent [c] containing a metal oxide. .

<Reference Example 4> (Preparation of antibacterial agent) An antibacterial agent containing a metal oxide [d] in the same manner as in Reference Example 3 except that titanium dioxide was used instead of zinc oxide in Reference Example 3. Got

Example (molding of antibacterial vinyl chloride resin composition) Vinyl chloride resin mixed with various additives in the proportions shown in Table 1 below (various stabilizers A to C shown in Table 2 below are already mixed) ) 100 parts and various antibacterial agents of the above [a] to [d] 1.
0 parts were blended in the proportions shown in Table 3 below, kneaded with a heating roll at 160 ° C for 5 minutes, and then pressed (180 ° C, 1
Thickness of 2 mm, length x width = 120 x 10 depending on 00 kg / cm ² )
It was molded into a plate shape of 0 mm and further cut into a size of 3 cm square to obtain a plate for evaluating antibacterial performance. However, the units of the numerical values in Table 3 are all parts.

[0034]

[Table 1] Vinyl chloride resin formulation table

[0035]

[Table 2] Stabilizer component table

Comparative Example 1 A plate was prepared in the same manner as in Example except that di-n-octyltin maleate polymer (A in Table 2) was used as a stabilizer and no silver-based inorganic antibacterial agent was added. And left blank.

Comparative Examples 2 and 3 Sulfur-containing organotin compounds (C in Table 2) as stabilizers
A plate was prepared by using the above and the same operation as in the example (the content ratio of the sulfur-containing organic tin compound was 1.7 parts per 100 parts of the vinyl chloride resin composition).

[0038]

[Table 3]

Test Example 1 (antibacterial property test) The antibacterial activity of each plate prepared in Examples 1 to 6 and Comparative Examples 1 to 3 was evaluated by the following method. Escherichia coli was used as the test bacteria, the antibacterial 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 ⁵ to 10 ⁶ . Stored at 27 ° C. After 0 hours from the start of storage (initial number of bacteria) and after storage 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. For this test solution, the pour plate culture method (37
The viable cell count is measured at 2 ° C for 2 days, and the plate is 3 cm
It was converted into the number of viable bacteria per 3 cm. In addition, the same operation was performed without using the test piece, which was used as a control. The results of the antibacterial test obtained as described above are shown in Table 4.

[0040]

[Table 4]

From the results shown in Table 4, the following is clear. That is, even if a silver-based inorganic antibacterial agent is added to the vinyl chloride resin, if the content ratio of the stabilizer containing the sulfur-containing organic tin compound is more than 1 part per 100 parts of the vinyl chloride resin composition, the vinyl chloride resin composition In the product, the antibacterial property of the silver-based inorganic antibacterial agent can hardly be exhibited (Comparative Examples 2 and 3), but as the stabilizer, not the sulfur-containing organic tin compound but the maleate organic tin compound or fatty acid salt. When an organic tin compound is added, the original antibacterial properties of the silver-based inorganic antibacterial agent can be exhibited (Examples 1 to 1).
6).

[0042]

The original excellent antibacterial property of the silver-based inorganic antibacterial agent can be exhibited not only in the composition of the present invention but also in a molded product obtained by molding the composition. The molded product obtained from the composition of the present invention requires antibacterial properties, antifungal properties or antialgal properties, and is useful in various fields where vinyl chloride resin molded products are used.

Claims (3)

[Claims] 1. An antibacterial vinyl chloride resin composition comprising an organotin compound as a stabilizer, a silver-based inorganic antibacterial agent, and a vinyl chloride resin, wherein the sulfur-containing organotin compound is contained in the antibacterial vinyl chloride resin. 0 to 1 per 100 parts by weight of composition
An antibacterial vinyl chloride resin composition, characterized in that it is part by weight. 2. The silver-based inorganic antibacterial agent is a phosphate-based antibacterial agent represented by the following general formula [1].
The antibacterial vinyl chloride resin composition described. _{Ag a A b M 2 (PO} 4) 3 · nH 2 O (1) (A is an alkali metal ion, alkaline earth metal ions,
At least one ion selected from ammonium ions or hydrogen ions, M is a tetravalent metal ion,
n is a number satisfying 0 ≦ n ≦ 6, and a and b are both positive numbers satisfying a + mb = 1. Here, m is the valence of A. ) 3. The antibacterial vinyl chloride resin composition according to claim 1 or 2, which contains at least one metal oxide selected from zinc oxide and titanium dioxide.