JP2009299004A - Transparent thermoplastic resin composition excellent in antibacterial activity, and molded article composed thereof - Google Patents

Abstract

[Constitution] 100 parts by weight of a transparent thermoplastic resin (A), 0.05 to 1.5 parts by weight of an antibacterial agent (B) containing glass eluting silver ions as an essential component, and a hindered phenol antioxidant (C ) 0.05 to 1.0 parts by weight, and optionally comprises 0.05 to 1.0 parts by weight of an ultraviolet absorber (D) and 0 to 0.1 parts by weight of a brightening agent (E). A transparent thermoplastic resin composition having excellent antibacterial properties, and a molded article comprising the same.
[Effect] The molded article obtained from the transparent thermoplastic resin composition having antibacterial properties of the present invention can be suitably used for all applications requiring antibacterial properties without causing a change in hue or poor transparency. Therefore, it is suitably used for components such as home appliances and stationery that require functions such as visibility, design, comfort, cleanliness, and safety, and its practical utility value is extremely high.
[Selection figure] None

Description

  The present invention provides a transparent thermoplastic resin composition having an antibacterial property with little initial coloration and excellent transparency and thermal stability by blending a specific thermoplastic antibacterial agent and an antioxidant with a transparent thermoplastic resin. , As well as a molded article comprising the same. Furthermore, a transparent thermoplastic resin composition having antibacterial properties excellent in light resistance in addition to the above-mentioned properties by blending the resin composition with a UV absorber and optionally a fluorescent brightening agent, and the same A molded article is provided.

  Transparent thermoplastic resins are widely used in the fields of electricity, electronics, OA, automobiles, etc. because of their light transmission properties. In each field, resins that satisfy the required performance are selected and used separately. ing. Recently, household appliances such as refrigerators and vacuum cleaners and sundries such as hanging rings are required to have performance that leads to comfort, cleanliness and safety. In order to satisfy these various performances, organic or inorganic antibacterial agents are generally used for transparent thermoplastic resins.

  In order to impart antibacterial properties to thermoplastic resins, inorganic antibacterial agents have been conventionally used because of their excellent safety and thermal stability. For example, an antibacterial agent comprising a zeolite (Patent Document 1) carrying a metal ion such as silver or zinc having a strong antibacterial action against bacteria, or a soluble glass (Patent Documents 2 and 3) containing the metal ion. Can be mentioned.

  In addition, a synthetic resin molded body having antibacterial properties including a water-soluble glass that releases silver ions and a highly water-absorbent resin body are disclosed in a non-moisture permeable synthetic resin and a highly water-absorbent resin (Patent Literature). 4 and 5).

However, since the molding temperature of the thermoplastic resin varies depending on the shape of the molded product and the resin used, it may be as high as 400 ° C. In such a case, the soluble glass reacts with the transparent resin and becomes transparent. There has been a problem that it leads to a decrease in performance and thermal stability.

Registration Registration 2135769 Japanese Patent Laid-Open No. 7-25635 Japanese Patent Laid-Open No. 1-313531 Japanese Patent Laid-Open No. 1-153748

  An object of the present invention is to provide a thermoplastic resin composition having little initial coloration, excellent transparency and thermal stability, and having antibacterial properties, and a molded article comprising the same. The present invention also provides a transparent thermoplastic resin composition having antibacterial properties excellent in light resistance in addition to these various properties, and a molded product comprising the same.

That is, the first aspect of the present invention comprises 100 parts by weight of a transparent thermoplastic resin (A), 0.05 to 1.5 parts by weight of an antibacterial agent (B) containing glass that elutes silver ions as an essential component, and a hinder. The present invention provides a transparent thermoplastic resin composition excellent in antibacterial properties, characterized by comprising 0.05 to 1.0 parts by weight of a dophenol antioxidant (C), and a molded product comprising the same.
Moreover, the second aspect of the present invention comprises 100 parts by weight of a transparent thermoplastic resin (A), 0.05 to 1.5 parts by weight of an antibacterial agent (B) containing glass that elutes silver ions as an essential component, and a hinder. From 0.05 to 1.0 part by weight of a phenol-based antioxidant (C), 0.05 to 1.0 part by weight of an ultraviolet absorber (D) and 0 to 0.1 part by weight of a fluorescent brightening agent (E) The present invention provides a transparent thermoplastic resin composition having excellent antibacterial properties, and a molded article comprising the same.

  The molded product obtained from the transparent thermoplastic resin composition having antibacterial properties of the present invention is suitably used for all applications requiring antibacterial properties without causing a change in hue or poor transparency. Therefore, it is suitably used for components such as home appliances and stationery that require functions such as visibility, design, comfort, cleanliness, and safety, and its practical utility value is extremely high.

  Examples of the transparent thermoplastic resin (A) used in the present invention include polycarbonate resin, polymethyl methacrylate, polystyrene, acrylonitrile / styrene copolymer, methacrylate / styrene copolymer, acrylonitrile / butadiene / styrene copolymer, and the like. Examples thereof include styrene-based copolymers, polyesters, polyetherimides, polyimides, polyamides, modified polyphenylene ethers, polyarylate, cycloolefin polymers, and polymer alloys obtained by blending polycarbonate and polyester. In particular, one or more resins selected from polycarbonate resin, polymethyl methacrylate, styrene (co) polymer, methyl methacrylate / styrene copolymer, polyarylate and cycloolefin polymer are preferably used. The degree of transparency of the transparent thermoplastic resin (A) is determined by the observer when the molded object of the resin is interposed between the observer and the object such as a light source. The performance to the extent that can be recognized.

  The polycarbonate resin is a polymer obtained by a phosgene method in which various dihydroxydiaryl compounds and phosgene are reacted or a transesterification method in which a dihydroxydiaryl compound and a carbonic ester such as diphenyl carbonate are reacted. As the above, a polycarbonate resin produced from 2,2-bis (4-hydroxyphenyl) propane (bisphenol A) can be mentioned.

  Examples of the dihydroxydiaryl compound include bisphenol 4-, bis (4-hydroxyphenyl) methane, 1,1-bis (4-hydroxyphenyl) ethane, 2,2-bis (4-hydroxyphenyl) butane, 2, 2-bis (4-hydroxyphenyl) octane, bis (4-hydroxyphenyl) phenylmethane, 2,2-bis (4-hydroxyphenyl-3-methylphenyl) propane, 1,1-bis (4-hydroxy-3) -Tert-butylphenyl) propane, 2,2-bis (4-hydroxy-3-bromophenyl) propane, 2,2-bis (4-hydroxy-3,5-dibromophenyl) propane, 2,2-bis ( Bis (hydroxyaryl) alkanes such as 4-hydroxy-3,5-dichlorophenyl) propane, 1,1- (4-hydroxyphenyl) cyclopentane, bis (hydroxyaryl) cycloalkanes such as 1,1-bis (4-hydroxyphenyl) cyclohexane, 4,4'-dihydroxydiphenyl ether, 4,4'-dihydroxy-3 Dihydroxy diaryl ethers such as 3,3'-dimethyldiphenyl ether, dihydroxy diaryl sulfides such as 4,4'-dihydroxydiphenyl sulfide, 4,4'-dihydroxydiphenyl sulfoxide, 4,4'-dihydroxy-3,3 ' Dihydroxy diaryl sulfoxides such as dimethyldiphenyl sulfoxide, dihydroxy diary such as 4,4'-dihydroxydiphenyl sulfone, 4,4'-dihydroxy-3,3'-dimethyldiphenyl sulfone Sulfone, and the like. These are used individually or in mixture of 2 or more types. In addition to these, piperazine, dipiperidyl hydroquinone, resorcin, 4,4'-dihydroxydiphenyl, and the like may be mixed and used.

  Furthermore, the above dihydroxyaryl compound and a trivalent or higher phenol compound as shown below may be used in combination. Trihydric or higher phenols include phloroglucin, 4,6-dimethyl-2,4,6-tri- (4-hydroxyphenyl) -heptene, 2,4,6-dimethyl-2,4,6-tri- (4 -Hydroxyphenyl) -heptane, 1,3,5-tri- (4-hydroxyphenyl) -benzol, 1,1,1-tri- (4-hydroxyphenyl) -ethane and 2,2-bis- [4 4- (4,4'-dihydroxydiphenyl) -cyclohexyl] -propane and the like.

  The viscosity average molecular weight of the polycarbonate resin is usually 10,000 to 100,000, preferably 15,000 to 35,000, and more preferably 17,000 to 28,000. In producing such a polycarbonate resin, a molecular weight regulator, a catalyst and the like can be used as necessary.

  The antibacterial agent (B) containing, as an essential component, glass that elutes silver ions used in the present invention is composed of a glass composition that can elute silver ions. In particular, the composition is preferably a polyhedron including silver oxide, phosphorus oxide, and zinc oxide. When the shape is a polyhedron, since it is easy to orient in a certain direction in the resin, it can be uniformly and easily mixed and dispersed in the resin, and light scattering is suppressed, which is preferable because of excellent transparency. .

The glass composition of the antibacterial agent (B) is preferably composed of 0.2 to 5% by weight of Ag ₂ O, 30 to 80% by weight of P ₂ O ₅ and 30 to 50% by weight of ZnO. Is done. Further, this _B 2 _{O 3} may be contained a 0.1 to 15 wt% and / or CaO in the range of 0.1 to 15 wt%. In the former case, silver ions can be stably released, and the transparency of the glass can be improved. In the latter case, a glass excellent in transparency and mechanical strength can be obtained.
When CaO is contained, the weight ratio of CaO to ZnO (ZnO / CaO) is more preferably in the range of 1.1-15.

  Moreover, in order to maintain the transparency of the resin, it is preferable that the average particle size of the glass composition be in the range of 0.1 to 300 μm. The antibacterial glass is readily available as a commercial product, and examples thereof include KM10D manufactured by Sinanen Zeomic.

  As a compounding quantity of the said antibacterial agent (B), it is 0.05-1.5 weight part per 100 weight part of transparent thermoplastic resins (A). If the blending amount is less than 0.05 parts by weight, it is difficult to obtain a sufficient antibacterial effect. On the other hand, if it exceeds 1.5 parts by weight, the initial colorability and transparency are impaired, which is not preferable. More preferably, it is the range of 0.1-1.0 weight part.

  Examples of the hindered phenol antioxidant (C) used in the present invention include pentaerythrityl-tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], thio And diethylene-bis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate. In particular, a compound represented by the following structural formula is preferably used. Examples of the antioxidant (C) include Irganox 1076 manufactured by Ciba Specialty Chemicals.

  The amount of the hindered phenol-based antioxidant (C) is 0.05 to 1.0 part by weight per 100 parts by weight of the transparent thermoplastic resin (A). A blending amount of less than 0.05 parts by weight is not preferable because a sufficient antioxidant effect cannot be obtained and thermal stability is poor. On the other hand, if the amount exceeds 1.0 part by weight, the thermal stability becomes insufficient at the time of retention during the molding process, and the yellowing is not preferable. More preferably, it is 0.1-0.8 weight part.

  Although it does not specifically limit as a ultraviolet absorber (D) used by this invention, The compound whose maximum absorption wavelength is 350 nm or less is preferable, More preferably, the compound whose maximum absorption wavelength is 320 nm or less is mentioned. In order to obtain a vivid color tone, an optical brightener (D) is used in the present invention as desired. Generally, the maximum absorption wavelength of the optical brightener is often in the range of 350 to 390 nm. Therefore, when an ultraviolet absorber having an absorption wavelength in the same region is used, it may be difficult to obtain energy absorption and fluorescence effects by the fluorescent brightening agent. Examples of the ultraviolet absorber having a maximum absorption wavelength of 320 nm or less include a compound having a cyanoacrylate ester as a basic structure and a compound having an oxanilide skeleton as a basic structure. The ultraviolet absorber is readily available as a commercial product, and examples thereof include Uvinul 3030 manufactured by BASF and Sanduvor VSU manufactured by Clariant Japan.

  The compounding quantity of a ultraviolet absorber (D) is 0.05-1.0 weight part per 100 weight part of transparent thermoplastic resins (A). If the blending amount is less than 0.05 parts by weight, it is difficult to obtain sufficient light resistance. On the other hand, if the amount exceeds 1.0 part by weight, the thermal stability is deteriorated, which is not preferable. More preferably, it is the range of 0.1-0.8 weight part.

  Examples of the optical brightener (E) used in the present invention include stilbene compounds, benzimidazole compounds, benzoxazole compounds, naphthalimide compounds, rhodamine compounds, coumarin compounds, and oxazine compounds. Is mentioned. The fluorescent brightener can be used alone or in combination of two or more. Commercially available products can be used as the fluorescent whitening agent. Examples of commercially available products include Blamkophor (trade name, manufactured by Bayer Co., Ltd.), Hakkol (trade name, manufactured by Showa Chemical Co., Ltd.), Hostarux, Leucophor (manufactured by Client Japan Co., Ltd., trade name), HOSTALUX KSN (manufactured by Client Japan Co., Ltd., trade name), Illuminar (manufactured by Showa Kako Co., Ltd., trade name), Kayphor (manufactured by Nippon Kayaku Co., Ltd.) Product name), Kaycoll (Nippon Soda Co., Ltd., trade name), Mikawhite (Nippon Kayaku Co., Ltd., Mitsubishi Chemical Co., Ltd., trade name), Mikephor (Mitsui BSF Dye Co., Ltd., trade name) , Nikkabright (trade name, manufactured by Nippon Chemical Industry Co., Ltd.), Tasphor (trade name, manufactured by Bayer Corp.), Whiteex (Sumitomo Chemical Co., Ltd., trade name). Of these, HOTALUX KSN (manufactured by Client Japan Co., Ltd., trade name) can be suitably used.

  The compounding amount of the optical brightener (E) is 0 to 0.1 parts by weight, more preferably 0.00005 to 0.01 parts by weight, with respect to 100 parts by weight of the polycarbonate resin. If the blending amount of the fluorescent brightening agent (E) exceeds 0.1 parts by weight, it is not preferable because color unevenness occurs or thermal stability decreases.

  When flame retardancy is required, various known flame retardants, for example, brominated flame retardants such as tetrabromobisphenol A oligomers, monophosphate esters such as triphenyl phosphate and tricresyl phosphate, bisphenol A diesters, etc. In order to further improve the flame retardancy, phosphorous flame retardants such as phosphate-type condensed phosphates such as phosphate, resorcin diphosphate, tetraxylenyl resorcin diphosphate, ammonium polyphosphate and red phosphorus, various silicone flame retardants And metal salts of aromatic sulfonic acid and perfluoroalkanesulfonic acid, preferably 4-methyl-N- (4-methylphenyl) sulfonyl-benzenesulfonamide potassium salt, diphenylsulfone- 3- potassium sulfonate, Potassium phenyl sulfonic -3-3'- disulfonic acid, sodium para-toluene sulfonic acid, also organic metal salts such as potassium perfluorobutane sulfonate and the like may be added. Among these flame retardants, phosphorus-based flame retardants can be suitably used because they can improve not only flame retardancy but also fluidity.

  The transparent thermoplastic resin composition having excellent antibacterial properties of the present invention includes known additives other than those mentioned above, such as lubricants [paraffin wax, n-butyl stearate, synthetic beeswax, natural beeswax, glycerin monoester, montanic acid. Wax, polyethylene wax, pentaerythritol tetrastearate, etc.], colorant [eg titanium oxide, carbon black, dye], filler [calcium carbonate, clay, silica, glass fiber, glass sphere, glass flake, carbon fiber, talc, Mica, various whiskers, etc.], fluidity improver, spreading agent [epoxidized soybean oil, liquid paraffin, etc.], other thermoplastic resins and various impact modifiers (polybutadiene, polyacrylate, ethylene Add rubber such as propylene rubber, methacrylate, styrene, acrylic Rubber-reinforced resin or the like compounds such as nitriles obtained by graft polymerization is exemplified.) Can be added as required.

  Although there is no restriction | limiting in particular about the compounding method of the structural component (A), (B), (C), (D), (E) of this invention, For example, after lump-mixing with a tumbler, a ribbon blender, a high-speed mixer etc. , A method in which the mixture is melt-kneaded and pelletized using a normal single-screw or twin-screw extruder, or each component is weighed separately, charged into a extruder from a plurality of feeders, and melt mixed. (B), (C), (D) and (E) are blended at a high concentration in (A), once melt-mixed and pelletized into a master batch, and then the desired master batch and (A) are obtained. It is also possible to mix according to the ratio. Then, when these components are melt-mixed, arbitrary conditions such as a position to be introduced into the extruder, an extrusion temperature, a screw rotation speed, a supply amount, and the like can be selected and pelletized. Further, the master batch and (A) can be directly mixed into an injection molding apparatus or a sheet extruder apparatus after dry mixing at a desired ratio to obtain a molded product.

  Hereinafter, the present invention will be described with reference to examples, but the present invention is not limited to these examples. Unless otherwise specified, “%” and “part” in the examples are based on weight standards.

The raw materials used are as follows.
Polycarbonate resin:
Caliber 200-13 manufactured by Sumitomo Dow
(Viscosity average molecular weight: 21500, hereinafter abbreviated as PC)
Antibacterial glass:
KM10D manufactured by Sinanen Zeomic (hereinafter abbreviated as antibacterial agent)
Antioxidant:
Irganox 1076 manufactured by Ciba Specialty Chemicals
(Hindered phenol antioxidant, hereinafter abbreviated as AO-1)
Sandstab PEPQ made by Clariant Japan
(Phosphorus antioxidant, hereinafter abbreviated as AO-2)

  Each of the above-mentioned various raw materials was put in a tumbler at the blending ratios shown in Tables 1-2, and after dry mixing for 10 minutes, a twin-screw extruder (TEX30α manufactured by Nippon Steel Works, shaft diameter = 30 mmφ, L / D = 41) was used for kneading at a melting temperature of 250 ° C. to obtain pellets for evaluation.

  Each of the obtained pellets was dried in advance at 120 ° C. for 4 hours, and then using an injection molding machine (J100E2P manufactured by Nippon Steel), 50 mm in length and 50 mm in width at a cylinder setting temperature of 270 ° C. A flat plate test piece having a thickness of 2 mm was prepared.

  Hereinafter, various evaluation items and measurement methods in the present invention will be described.

1. Initial coloring property Using the obtained flat plate test piece, the yellowness index (YI) was measured according to ASTM D-1925 by a spectrophotometer (CMS-35SP manufactured by Murakami Color Research Laboratory). YI represents the degree of yellowness. The smaller the YI, the smaller the yellowishness and the less the initial coloring. As the evaluation criteria for YI, those with a YI value of less than 8.5 were accepted (◯), and those with a value of 8.5 or more were rejected (x).

2. Thermal stability Each of the obtained pellets was previously dried under the conditions of 120 ° C. × 4 hours, and then 15 ° C. using an injection molding machine (J100E2P manufactured by Nippon Steel Works) at a cylinder set temperature of 320 ° C. After preparing a flat plate test piece (length 50 mm, width 50 mm, thickness 2 mm) before and after a minute residence, the change in YI (ΔYI) was measured with a spectrophotometer (CMS-35SP manufactured by Murakami Color Research Laboratory). ΔYI represents the difference in yellowness before and after the stay. The smaller ΔYI, the smaller the color change and the better the thermal stability. As a criterion for the evaluation of ΔYI, a case where the value of ΔYI was less than 2.0 was judged as acceptable (◯), and a case where it was 2.0 or more was judged as unacceptable (×).

3. Transparency Haze was measured with a haze meter (HM-150, manufactured by Murakami Color Research Co., Ltd.) using a flat plate test piece obtained under the same conditions (cylinder setting temperature 270 ° C.) as in the initial colorability evaluation. As an evaluation standard, a haze value of less than 7.0 was accepted (◯), and a haze value of 7.0 or more was rejected (x).

4). Antibacterial test The antibacterial test was carried out based on JIS Z 2801 (film adhesion method). More specifically, the surface of the initial coloring properties evaluation and similar conditions flat test pieces obtained in (cylinder temperature 270 ° C.), was added dropwise a bacterial suspension containing 10 ⁵ E. coli, PE-made film thereon The cells attached to the PE film and the flat plate test piece after washing at 35 ° C. for 24 hours were washed out with an SCDLP medium, transferred to a petri dish and cultured at 35 ° C. for 45 hours. ) Was counted. The evaluation standard is log ₁₀ (when the number of viable Escherichia coli counted by the film adhesion method using a plate test piece made of a resin composition not containing the antibacterial agent (B) of the present invention is x _10. x / y) (hereinafter abbreviated as antibacterial activity value) was 2.0 or more, and was acceptable (◯), and less than 2.0 was rejected (x).
Furthermore, except that E. coli was changed to S. aureus, an antibacterial activity test was performed under the same procedures and conditions as described above to determine an antibacterial activity value, and evaluated according to the same criteria. The respective results are shown in Tables 1 and 2.

5. Comprehensive judgment In the initial colorability, thermal stability, haze, and antibacterial evaluation, those that passed were all passed (◯), and those that were not passed were rejected (×).

  As shown in Table 1, when the configuration of the present invention was satisfied (Examples 1 to 5), all the evaluation items had sufficient performance.

On the other hand, as shown in Table 2, when the configuration of the present invention was not satisfied (Comparative Examples 1 to 5), each case had some defects.
In Comparative Example 1, the antibacterial agent was inferior in antibacterial properties, although the amount of the antibacterial agent was less than the prescribed amount and the initial colorability, thermal stability and transparency passed.
Comparative Example 2 was a case where the blending amount of the antibacterial agent was larger than the specified amount, and although the antibacterial property passed, the initial colorability, thermal stability and transparency were inferior.
Comparative Example 3 was a case where the blending amount of the hindered phenol antioxidant was larger than the specified amount, and although the initial colorability, transparency and antibacterial properties passed, the thermal stability was poor.
Comparative Example 4 was a case where an antioxidant other than the hindered phenol antioxidant was used, and although the antibacterial property passed, initial colorability, thermal stability and transparency were inferior.
Comparative Example 5 was a case where no hindered phenolic antioxidant was blended, and although the initial colorability, transparency and antibacterial properties passed, the thermal stability was poor.

  The same operation as in Example 1 was performed except that an ultraviolet absorber and a fluorescent brightening agent were additionally added to the resin composition of Example 1 at the mixing ratios shown in Table 3 to obtain pellets of various resin compositions. Moreover, the flat plate test piece for evaluation was created using the pellet obtained similarly to Example 1. FIG. The ultraviolet absorbers and fluorescent brighteners used are as follows.

UV absorber:
Sanduvor VSU made by Clariant Japan
(Oxalic acid anilide ultraviolet absorber, hereinafter abbreviated as UVA)
Optical brightener:
HOSTALUX KSN (hereinafter abbreviated as FWA) manufactured by Clariant Japan

Additional evaluation items and measurement methods are as follows.
7). Light resistance Using the obtained flat plate test piece, it was irradiated for 6 hours with a super accelerated weathering tester iSuper UV tester (SUV-W13 manufactured by Iwasaki Electric Co., Ltd.). Thereafter, the yellowness index (YI) of the sample before and after irradiation was measured with a spectrophotometer (CMS-35SP manufactured by Murakami Color Research Laboratory) in accordance with ASTM D-1925. The difference in YI before and after irradiation (ΔYI) was determined. As a reference for evaluation of ΔYI, a value of ΔYI of less than 5 was accepted (◯), and a value of 5 or more was rejected (x).

8). Measurement of bluishness b * was measured with a spectrophotometer (CMS-35SP manufactured by Murakami Color Research Laboratory) using the obtained flat plate test piece. b * represents the degree from yellow to blue, and the smaller b *, the less yellow and the stronger blue.

9. Comprehensive judgment In the initial colorability, light resistance, thermal stability, haze, and antibacterial evaluation, all passed were evaluated as pass (◯), and others were rejected (x). Moreover, the bluish evaluation at the time of adding a fluorescent whitening agent was also implemented. The results are shown in Table 3.

  As shown in Table 3, when the configuration of the present invention was satisfied (Examples 6 to 8), all the evaluation items had sufficient performance.

On the other hand, when the configuration of the present invention was not satisfied (Comparative Example 6 and Comparative Example 7), each case had some drawbacks.
Comparative Example 6 was a case where the blending amount of the ultraviolet absorber was less than the specified amount, and although the initial colorability, thermal stability, transparency and antibacterial properties passed, the light resistance was inferior.
Comparative Example 7 was a case where the blending amount of the ultraviolet absorber was larger than the specified amount, and although the initial colorability, light resistance, transparency and antibacterial properties passed, the thermal stability was inferior.

Claims (9)

  100 parts by weight of a transparent thermoplastic resin (A), 0.05 to 1.5 parts by weight of an antibacterial agent (B) containing a glass eluting silver ions as an essential component, and a hindered phenol antioxidant (C) 0. A transparent thermoplastic resin composition having excellent antibacterial properties, comprising from 05 to 1.0 parts by weight.   100 parts by weight of a transparent thermoplastic resin (A), 0.05 to 1.5 parts by weight of an antibacterial agent (B) containing glass eluting silver ions as an essential component, hindered phenol antioxidant (C) 0. It was excellent in antibacterial properties characterized by comprising 0.05 to 1.0 parts by weight, 0.05 to 1.0 parts by weight of an ultraviolet absorber (D) and 0 to 0.1 parts by weight of a brightening agent (E). A transparent thermoplastic resin composition.  The transparent thermoplastic resin (A) is one or more selected from polycarbonate resin, polymethyl methacrylate, styrene (co) polymer, methyl methacrylate / styrene copolymer, polyarylate and cycloolefin polymer. 3. The transparent thermoplastic resin composition having excellent antibacterial properties according to claim 1 or 2.  The transparent thermoplastic resin composition having excellent antibacterial properties according to claim 1 or 2, wherein the shape of the glass eluting silver ions contained in the antibacterial agent (B) is a polyhedron.  The antibacterial agent according to claim 1 or 2, wherein the blending amount of the antibacterial agent (B) is 0.1 to 1.0 part by weight per 100 parts by weight of the transparent thermoplastic resin (A). Transparent thermoplastic resin composition having excellent properties. The said hindered phenolic antioxidant (C) is a compound shown by following structural formula, The transparent thermoplastic resin composition excellent in antibacterial property of Claim 1 or Claim 2 characterized by the above-mentioned.

  The amount of the hindered phenolic antioxidant (C) is 0.1 to 0.8 parts by weight per 100 parts by weight of the transparent thermoplastic resin (A). 2. A transparent thermoplastic resin composition having excellent antibacterial properties according to 2.   The antibacterial property according to claim 2, wherein the blending amount of the ultraviolet absorber (D) is 0.1 to 0.8 parts by weight per 100 parts by weight of the transparent thermoplastic resin (A). Transparent thermoplastic resin composition.   A molded article obtained by molding the antibacterial transparent thermoplastic resin composition according to any one of claims 1 to 8.