JPH10245493A - Mildew-proofing antibacterial thermoplastic resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject composition kneadable and mixable into molten resins, having mildew-proofing and antibacterial activities and useful for various OA instruments, etc., by adding a mercaptobenzothiazole compound to a thermoplastic resin. SOLUTION: This composition is composed of (A) 99.9-80wt.% of a thermoplastic resin and (B) 0.1-20wt.% of a mercaptobenzothiazole compound. Preferably, the composition is composed of 99.9-30wt.% of the component A, 0.1-20wt.% of the component B and (C) 0.1-30wt.% of an alkali compound. Preferably, the component A is a styrene resin, etc., the component B is 2- mercaptobenzothiazole of the formula, etc., and the component C is dimethyl laurylamine, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a thermoplastic resin composition having excellent antifungal and antibacterial properties.

[0002]

2. Description of the Related Art Thermoplastic resins are used in a wide range of fields such as electronic and electric fields, home electric appliances, automobiles, sanitary fields such as toilet seats, kitchens and bathrooms, and miscellaneous goods.
In recent years, it has been pointed out that bacteria and molds proliferate in products used for these, and have a bad effect on human bodies.

As a method for imparting antibacterial property to a thermoplastic resin, there is a method in which an antibacterial agent is kneaded into a thermoplastic resin or a method in which an antibacterial agent is applied to the surface of a thermoplastic resin product.
The coating method is effective, but takes time and labor, and is not preferable in terms of productivity. At present, as an antibacterial agent, an inorganic antibacterial agent is mainly used for kneading, while an organic antibacterial agent is mainly applied to a product in a liquid state. Representative examples of inorganic antibacterial agents include zeolites and synthetic minerals substituted with a metal such as silver, and organic antibacterial agents include chlorohexidine and quaternary ammonium salts.
Although these antibacterial agents have antibacterial properties, they have almost no fungicidal properties and are expensive.

[0004] On the other hand, as a method for imparting antifungal property to a thermoplastic resin, there is a method of kneading an antifungal agent into the thermoplastic resin.
Representative fungicides include thiazolyl benzimidazole (TBZ) and binazine (10,10'-oxybisphenoxyarsine), but thiazolyl benzimidazole has low antibacterial properties, and binazine has antibacterial properties. Concerns about safety cannot be completely denied because they contain arsenic.

[0005] Under these circumstances, there has been a demand for a safe and inexpensive resin material having both antifungal properties and antibacterial properties.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide a thermoplastic resin composition which can be kneaded into a molten resin and has antifungal and antibacterial properties at a low cost.

[0007]

Means for Solving the Problems The present inventors have found that the addition of a mercaptobenzothiazole-based compound to a thermoplastic resin can provide fungicidal and antibacterial properties, and have reached the present invention. That is, the present invention is as follows. (1) (A) 99.9 to 80% by weight of a thermoplastic resin,
(B) Mercaptobenzothiazole compound 0.1 to 2
A thermoplastic resin composition comprising 0% by weight. (2) (A) 99.8 to 50% by weight of a thermoplastic resin,
(B) Mercaptobenzothiazole compound 0.1 to 2
A thermoplastic resin composition comprising 0% by weight and (C) 0.1 to 30% by weight of an alkali compound. (3) The resin composition according to the above (1) or (2), which has antifungal and antibacterial properties. (4) A molded article of the resin composition according to the above item 3.

Hereinafter, the present invention will be described in detail. In the present invention, the thermoplastic resin used as the component (A) can be arbitrarily selected from thermoplastic resins used as raw materials in ordinary injection molding, extrusion molding, blow molding, sheet molding, foam molding and the like. In general, a thermoplastic resin having a molding temperature of 300 ° C. or less is preferable.

Such materials include, for example, styrene resins, olefin resins, methacrylic resins, polyvinyl chloride resins, polyvinylidene chloride resins, polyamide resins, polyester resins, polyurethane resins, polycarbonate resins, polyacetal resins, Examples thereof include polyphenylene ether resin, fluororesin, and various thermoplastic elastomers. Among them, styrene resin, olefin resin, methacrylic resin, and polyvinyl chloride resin are preferable. Particularly, a styrene resin is preferable.

As the styrene-based resin, those generally used for molding, such as styrene homopolymer (PS), high impact polystyrene (HIPS), methyl methacrylate-styrene copolymer (MS) ), Methyl methacrylate / butadiene / styrene copolymer (MBS), styrene / maleic anhydride copolymer (SMA), styrene / methacrylic acid copolymer (SMAA), α-methylstyrene or maleimide A heat-resistant styrene resin, further, a styrene / acrylonitrile copolymer resin, an α-methylstyrene / acrylonitrile copolymer resin, and the like can be given.

Here, as the styrene / acrylonitrile copolymer resin, acrylonitrile / styrene copolymer (AS), acrylonitrile / styrene / butadiene copolymer (ABS), acrylonitrile / styrene / acrylic rubber copolymer (AAS) Acrylonitrile / styrene / chlorinated polyethylene copolymer (ACS), acrylonitrile / styrene / ethylene / propylene rubber copolymer (AES), acrylonitrile / styrene / ethylene / vinyl acetate copolymer, α-methylstyrene or maleimide Including α-methylstyrene / acrylonitrile copolymer resin, the styrene portion of the styrene / acrylonitrile copolymer resin is replaced by α-methylstyrene.
-Methylstyrene / acrylonitrile copolymer resin.

As the olefin resin, those generally used for molding, for example, polyethylene resins such as ultra-low-density polyethylene, low-density polyethylene, linear low-density polyethylene, medium-low-density polyethylene, and high-density polyethylene Having a vinyl acetate content of 0.1 to 25
% By weight of ethylene / vinyl acetate copolymer, 0.1 to 25% by weight of ethylene / acrylic acid copolymer, propylene homopolymer, ethylene content of 2 to 4%
0 mol% of a crystalline propylene / ethylene block copolymer, a crystalline ethylene / propylene random copolymer having an ethylene content of 0.5 to 10 mol%, polybutene, ethylene / propylene rubber, ethylene / propylene / diene rubber, etc. Can be mentioned.

Examples of the methacrylic resin include, for example, methyl methacrylate homopolymer, and other monomers such as styrene, α-methylstyrene, acrylonitrile, various acrylates and methacrylates, and the like. Methacrylic resin which has improved various performances, and furthermore, methyl methacrylate, styrene, acrylonitrile, various acrylic acid esters in polymers mainly composed of acrylates and methacrylic esters or polymers mainly composed of butadiene Impact-resistant methacrylic resin obtained by graft copolymerization of methacrylic acid ester or methacrylic acid ester.

Examples of the above polyvinyl chloride resin include, in addition to vinyl chloride homopolymer, ethylene chloride, propylene, acrylonitrile, vinylidene chloride, and vinyl chloride.
MBS resin, ABS resin, copolymer obtained by polymerizing vinyl acetate or the like as a comonomer, or polyvinyl chloride,
Examples thereof include nitrile rubber, chlorinated polyethylene, EVA-PVC graft copolymer, and modified polyvinyl chloride resin to which various plasticizers are added.

These thermoplastic resins have a weight average molecular weight (Mw) of 1,000 to 1,000,000, preferably 10,000 to 1,000,000, and more preferably 50,000 to 800,000. Those in the range are preferred. Further, these thermoplastic resins may be used alone or in combination of two or more kinds as a polymer alloy.

The (B) mercaptobenzothiazole compound used in the present invention is a compound having a 2-mercaptobenzothiazole skeleton represented by the following chemical formula 1, and a compound having a substituent on this benzene ring: -S
Includes compounds where the hydrogen of the H group is substituted.

[0017]

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For example, 2-mercaptobenzothiazole, zinc salt of 2-mercaptobenzothiazole, sodium salt of 2-mercaptobenzothiazole, N-ter
t-butyl-2-mercaptobenzothiazole, N-oxydiethylene-2-benzothiazolylsulfenamide, N, N-dicyclohexyl-2-benzothiazolylsulfenamide, cyclohexylamine salt of 2-mercaptobenzothiazole, N -Cyclohexyl-2-benzothiazolylsulfenamide, 2-mercaptomethylbenzothiazole and the like. Among these, 2-mercaptobenzothiazole is most preferred.

In general, 2-mercaptobenzothiazole is synthesized by reacting aniline with carbon disulfide and sulfur in a high-pressure kettle. It is generally called "M" and is used as a vulcanization accelerator for sulfur vulcanization of rubber. The mercaptobenzothiazole compound is 0.1 to 20% by weight, preferably 0.5 to 10% by weight, and more preferably 1 to 8% by weight.
Used. If the amount is small, the antibacterial and antifungal effects are not obtained, and if the amount is large, various problems during molding are caused, which is not preferable.

In the present invention, the use of an alkali compound (C) is more effective. The alkali compound (C) used in the present invention is a compound exhibiting alkalinity, and is added in an amount of 0.1 to 30% by weight, preferably 0.5 to 15% by weight, and more preferably 1 to 10% by weight. Examples thereof include alkali metals, alkaline earth metals, and compounds thereof, amine compounds, and quaternary ammonium compounds. Amine compounds are more preferred in terms of water resistance.

Examples of the alkali metal include Li, Na,
K, Rb, Cs and the like can be mentioned, and examples of the alkaline earth metal include Be, Mg, Ca, Sr, Ba and the like. These compounds include hydroxides, carbonates, bicarbonates, carboxylates, oxalates, salts with phenols, alkoxides, and the like. Particularly, carboxylate is preferred. Salts with strong acids are not preferred because they are no longer alkaline. Examples of specific carboxylic acids include stearic acid, montanic acid, behenic acid, lauric acid, myristic acid, palmitic acid, lactic acid, butyric acid, acetic acid, maleic acid, oleic acid, stearoyl lactic acid, pantothenic acid, succinic acid, 12 -Aliphatic carboxylic acids such as hydroxystearic acid, fumaric acid, tartaric acid, gluconic acid, cyclohexylbutyric acid, ethylenediaminetetraacetic acid, etc .; aromatic carboxylic acids such as benzoic acid, salicylic acid, aliphatic alkyl-substituted benzoic acid, phthalic acid, nicotinic acid, etc. , Alkyl ether carboxylic acids, N-acyl amino acids, acylated peptides and the like. Among these, an alkyl carboxylic acid is preferable, and a compound having 6 or more carbon atoms is more preferable.

Specific examples of the amine compound include methylamine, ethylamine, propylamine, butylamine,
Alkyl primary amines such as propylamine, pentylamine, hexylamine, heptylamine, octylamine, decylamine, laurylamine, myristylamine, palmitylamine, stearylamine, coconutamine, tallowamine, dimethylamine, diethylamine,
Dipropylamine, cybutylamine, dioctylamine, didecylamine, dilaurylamine, dimyristylamine, dipalmitylamine, methylstearylamine, distearylamine, octylated diphenylamine, N, N′-diphenyl-p-phenylenediamine,
Alkyl secondary amines such as N-phenyl-N′-isopropyl-p-phenylenediamine, trimethylamine,
Triethylamine, tributylamine, trioctylamine, dimethyloctylamine, dimethyldecylamine, dimethyllaurylamine, dimethylmyristylamine, dimethylpalmitylamine, dimethylstearyl,
Dilauryl monomethylamine, alkyl tertiary amines such as trioctylamine, stearyl propylene diamine,
Tallow propylene diamine, ethylene diamine, propylene diamine, hexamethylene diamine, polyamines such as hexamethylene tetramine, ethanolamine, diethanolamine, alkanolamines such as triethanolamine, pyridine, picoline, ethylpyridine, propylpyridine, butylpyridine, lutidine, Colludin, methylethylpyridine, diethylpyridine, methylbutylpyridine, dipropylpyridine, C8-C20 alkylpyridine, methylethylpropylpyridine, picolinamide, isonicotinamide, aminopyridine,
Diaminopyridine, triaminopyridine, aminomethylpyridine, aminoethylpyridine, aminopropylpyridine, aminodimethylpyridine, diaminomethylpyridine, dipyridyl, 2,2′-dipyridylamine, 4-dimethylaminopyridine, 4-pyrrolidinopyridine, −
Piperidinopyridine, hydroxypyridine, dihydroxypyridine, hydroxymethylpyridine, chloropyridine, cyanopyridine, pyridinemethanol, pyridinedimethanol, pyridineethanol, methylpyridineethanol, 2- (2-pyridyl) -1,3-propanediol, 2-hydroxymethyl-2- (4-pyridyl)-
1,3-propanediol, methoxyethylpyridine,
Aminomethylpyridine, pyridylacetone, bis-2-
Picolylamine, alkylaminomethylpyridine, phenylpyridine, benzylpyridine, quinoline, cyclopentenopyridine 1,3-di- (4-pyridyl) propane, 2,4,6-tri- (4-pyridyl) -s-triazine Pyridine, vinylpyridine polymer, polyhexamethylene picanide, polyallylamine, and polymer having an amino group such as polydimethylaminoethyl methacrylate. In addition, anilines, morpholines, guanidines, piguanides, and the like can also be used. Among these, amines having 6 or more carbon atoms are preferable from the viewpoint of water resistance. Further, a tertiary amine having strong basicity is most preferable, and a secondary amine and a primary amine are more preferable in this order.

The molded article in the present invention includes injection molding, extrusion molding, compression molding, inflation molding, blow molding, sheet molding, foam molding, powder molding, vacuum molding, sinter molding, calender molding, roll rolling molding, and casting. An object formed by a forming method such as forming. At this time, the final molded product may be directly obtained, or may be formed again into a desired molded product after being formed into a film, a biaxially stretched film, a sheet, a foamed sheet, a foamed bead, and the like. .

There is no particular limitation on the method for producing the thermoplastic resin composition of the present invention.
(B) Further, after mixing the component (C) at a predetermined mixing ratio with a Henschel mixer or a tumbler, a single screw or multi-screw extruder having two or more screws, a Banbury mixer, a kneader,
It can be obtained by melt-kneading using a known kneading device such as a roll. Alternatively, the mixing of the raw materials using a Henschel mixer, a tumbler or the like may be omitted, and the various raw materials may be supplied to the melt-kneading apparatus using separate feeders and supply apparatuses and kneaded.

In the present invention, if necessary, various additive components such as a plasticizer, a lubricant, a stabilizer, an antioxidant, an ultraviolet absorber, a flame retardant, a mold release agent, and the like are polymerized. It can also be added at the time of molding of the polymer molded article. Furthermore, unless it violates the purpose of the present invention,
It may be used in combination with other fungicides or antibacterial agents. The thermoplastic polymer composition of the present invention thus obtained can be obtained by a known method generally used for molding a thermoplastic polymer, for example, a method such as injection molding, extrusion molding, blow molding, inflation molding, or vacuum molding. To form various molded articles. In addition, films, biaxially stretched films, sheets,
After being molded into a foamed sheet, foamed beads, or the like, it is molded into a desired molded body.

[0026]

Hereinafter, the present invention will be described in more detail by way of examples, but the present invention is not limited to these examples. The measurement of each item is performed according to the following method. <Evaluation of mold> Penicillium phenikilosam (P. phenikilosam; IFO 6345) and Trichoderma bilde (T. viride; IFO 3113) were used as test strains.
Using 7), a test specimen was prepared by cutting a flat molded article (thickness: 2 mm) of the resin composition into 50 mm × 50 mm, and wiping the molded article surface with a gauze impregnated with ethanol to clean the specimen. And

On the other hand, a test bacterial solution is applied to a potato dextrose agar medium on a sterile petri dish made of polystyrene, and 0.1 ml of a solution containing mold spores is placed on a test sample in a volume of 20 to 100 ml.
Divide into 25 drops and place on the test specimen surface. The lid of the petri dish is placed, and the whole petri dish and the gauze soaked in water are put into a polyethylene bag with a chuck, and the state of mold generation is observed after leaving the container at 28 ° C. and a humidity of 99% for one week. A substance in which the generation of mold was not observed at all was represented by ○, a substance in which the generation was partially observed but the generation was suppressed was represented by Δ, and a substance which occurred similarly to the blank was represented by ×. <Evaluation of bacteria> A flat molded product (2 mm thick) of the resin composition
Cut into 0 mm x 50 mm, wipe the surface of the molded body with gauze soaked with ethanol, and clean it.
The sample was allowed to stand for 24 hours in a 60% relative humidity atmosphere to obtain a sample for an antibacterial test. 0.5 ml of the bacterial solution was inoculated into the test sample, and
After a polyethylene film of 5 mm × 45 mm was adhered, the film was stored at 37 ° C.
Viable bacteria are washed out with a DLP medium (manufactured by Nippon Pharmaceutical Co., Ltd.).
An agar plate culture method (37 ° C., 24 ° C.) using a standard agar medium for cell count measurement (manufactured by Nissui Co., Ltd.)
Time), the number of surviving bacteria is measured and converted to the number of surviving bacteria per sample. The test results are expressed as the logarithmic value of the difference in the number of viable bacteria from the blank. That is, the larger the value, the greater the effect.

The test bacterium was Escherichia coli (IFO3301).
Use The test bacterial solution is prepared by suspending Escherichia coli in a solution prepared by dissolving 5 mg of meat extract, 10 mg of peptone, and 5 mg of sodium chloride in 1 liter of distilled water so that the number of bacteria per ml becomes 10 ⁶ . <Raw materials> Stylon 403 manufactured by Asahi Kasei Kogyo Co., Ltd. as rubber-reinforced polystyrene (HIPS) and Styron 6 manufactured by Asahi Kasei Kogyo Co., Ltd. as polystyrene (GPPS)
80, Stylac-ABS200 manufactured by Asahi Kasei Kogyo Co., Ltd. as an acrylonitrile-butadiene-styrene copolymer (ABS resin); modified polyphenylene ether was kneaded with a polyaxial extruder in a ratio of 3: 7 of polyphenylene ether and rubber-reinforced polystyrene. As a polyacetal resin (POM), Tenac-C5520 manufactured by Asahi Kasei Kogyo Co., Ltd., as a polypropylene (PP), Show Allomer MK211 manufactured by Showa Denko KK, and as a high density polyethylene (HDPE), Suntec-HD J310 manufactured by Asahi Kasei Kogyo Co., Ltd. . 2-mercaptobenzothiazole uses Noxeller MP manufactured by Ouchi Shinko Chemical Industry Co., Ltd. Dimethyllaurylamine is manufactured by Kao Corporation. Sodium carbonate (Na ₂ C
For O ₃ ) and sodium stearate, reagent special grade manufactured by Wako Pure Chemical Industries, Ltd. is used.

[0029]

Examples 1 to 12 and Comparative Examples 1 to 3 After dry blending the compositions shown in Tables 1 and 2, a twin screw extruder (ZSK-25, WE
(RNER & PFLEIDERER, Germany)
Is melt-kneaded and pelletized to obtain a polymer composition. The pellets of the obtained polymer composition are molded into a test plate (100 mm × 100 mm × 2 mm (t)) using an injection molding machine (Autoshot 50C, manufactured by FANUC CORPORATION).

Tables 1 and 2 show the results of the mold and fungus evaluation of the obtained resin molded product.

[0031]

[Table 1]

[0032]

[Table 2]

From Tables 1 and 2, it can be seen that all of the resin molded articles of the examples show excellent fungicide resistance. Further, according to Examples 4, 5, and 6, and Comparative Examples 1, 3, and 2, a synergistic effect of fungicidal and antibacterial properties due to the addition of an alkali compound (dimethyllaurylamine, sodium carbonate, and sodium stearate) was exhibited. I understand that there is.

[0034]

The antibacterial thermoplastic resin composition of the present invention comprises:
It exhibits excellent antibacterial activity and also has excellent antifungal properties. For this reason, the thermoplastic polymer composition has a wide range of applications, for example, home appliances such as various OA equipment and refrigerators,
Or various sanitary articles such as toilet seats, wash basin parts, outer handle bezels, door handles, shift lever heads, turn indicators, steering wheel and other interior and exterior parts, wallpaper flooring and other construction materials, other vehicle parts, daily necessities, toys It is suitable for a wide range of uses such as miscellaneous goods.

Claims (4)

[Claims] (A) 99.9 to 80% by weight of a thermoplastic resin, (B) 0.1 of a mercaptobenzothiazole compound.
A thermoplastic resin composition comprising up to 20% by weight. (A) 99.8 to 50% by weight of a thermoplastic resin, (B) 0.1 of a mercaptobenzothiazole compound.
-20% by weight, and (C) an alkali compound 0.1-30
A thermoplastic resin composition consisting of% by weight. 3. The resin composition according to claim 1, which has fungicidal and antibacterial properties. 4. A molded article of the resin composition according to claim 3.