JP2014118414A - Polycarbonate resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polycarbonate resin composition containing 100 pts.wt. of a resin component consisting of a polycarbonate resin (A) of 35 to 75 wt.% and a specific surface hardness improver (B) of 25 to 65 wt.% and 0.05 to 1.5 pts.wt. of an antibacterial agent containing a glass eluting a silver ion as an essential component (C).SOLUTION: A molded article obtained from the polycarbonate resin composition has a high surface hardness and antibacterial properties while maintaining properties which a polycarbonate resin has. Therefore it is suitably used for applications for which avoidance of scratching on a surface of a molded article and transparency are required, and applications which require functions such as comfort, cleanliness and safety, for example applications such as a display, consumer electronics or stationery.

Description

  The present invention relates to a polycarbonate resin composition excellent not only in surface hardness but also in hue and antibacterial properties.

  Polycarbonate resin is a thermoplastic resin excellent in transparency, impact resistance, heat resistance, thermal stability, and the like, and is widely used in fields such as electricity, electronics, ITE, machinery, and automobiles. However, the polycarbonate resin has a drawback that it has a low surface hardness and is easily damaged, and its use is limited. In addition, household appliances such as refrigerators and vacuum cleaners and miscellaneous goods such as hanging rings are required to have performance that leads to comfort, cleanliness and safety. In order to satisfy these various performances, generally, a technique of blending an organic or inorganic antibacterial agent with a polycarbonate resin is employed.

  In order to improve the susceptibility to scratches, a method of coating the surface of a polycarbonate resin with an ultraviolet curable resin has been proposed. However, this method has a problem that due to the flexibility derived from the polycarbonate resin, the pencil hardness required for display applications cannot be satisfied.

  On the other hand, in order to obtain a molded article excellent in surface hardness and transparency, a resin composition of a polycarbonate resin and an acrylic surface hardness improver has been proposed. However, this resin composition has a problem that the surface hardness is high but the hue is inferior.

  In order to impart antibacterial properties to polycarbonate 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 3) carrying a metal ion such as silver or zinc that exhibits a strong antibacterial action against bacteria, or a soluble glass (Patent Documents 4 and 5) 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 Documents). 6 and 7).

  However, the molding process temperature may vary depending on the shape of the molded product and the resin used, but it may be as high as 400 ° C. In such a case, the soluble glass reacts with the transparent resin, resulting in transparency and heat stability. There was a problem of causing a decline in sex.

JP 2009-280713 A JP 2010-116501 A Japanese Patent No. 3293639 Japanese Patent No. 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 polycarbonate resin composition having the above-mentioned problems, that is, high surface height, excellent hue, and antibacterial properties.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have used a specific surface hardness improver and an antibacterial agent, so that the polycarbonate resin composition is excellent not only in surface hardness but also in antibacterial properties. Has been found, and the present invention has been completed.

That is, the present invention is an antibacterial agent comprising, as an essential component, glass eluting silver ions per 100 parts by weight of a resin component comprising 35 to 75% by weight of a polycarbonate resin (A) and 25 to 65% by weight of a surface hardness improver (B). (C) A polycarbonate resin composition containing 0.05 to 1.5 parts by weight, wherein the surface hardness improver (B) is
A copolymer comprising 5 to 80% by weight of aromatic (meth) acrylate units and 20 to 95% by weight of methyl methacrylate units, and the weight average molecular weight of the copolymer being 5000 to 30000 The present invention relates to a polycarbonate resin composition.

  The molded product obtained from the polycarbonate resin composition of the present invention has high surface hardness and antibacterial properties while maintaining the properties of the polycarbonate resin. For this reason, applications where scratches on the surface of molded products are avoided and transparency is required and functions such as comfort, cleanliness, and safety are required, such as components for displays, household appliances, stationery, etc. It is suitably used for

  Hereinafter, the present invention will be described in detail.

  The polycarbonate resin (A) used in the present invention is a phosgene method in which various dihydroxydiaryl compounds and phosgene are reacted or a transesterification method obtained by reacting a dihydroxydiaryl compound and a carbonate such as diphenyl carbonate. A typical example is a polycarbonate resin produced from 2,2-bis (4-hydroxyphenyl) propane (bisphenol A).

  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 can be used alone or in admixture of two or more. 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 (A) 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 surface hardness improver (B) used in the present invention is a copolymer composed of 5 to 80% by weight of aromatic (meth) acrylate units and 20 to 95% by weight of methyl methacrylate units. The weight average molecular weight of the coalescence is 5000-30000. In the present specification, (meth) acrylate means acrylate or methacrylate.

  Examples of the aromatic (meth) acrylate include phenyl (meth) acrylate and benzyl (meth) acrylate. These can be used alone or in combination of two or more. Of these, phenyl methacrylate and benzyl methacrylate are preferable, and phenyl methacrylate is more preferable.

  If the content of the aromatic (meth) acrylate unit in the surface hardness improver (B) is 5% by weight or more, transparency is maintained, and if it is 80% by weight or less, the phase with the polycarbonate resin (A) is maintained. Since the capacity is not too high and the transferability to the surface of the molded body is not lowered, the surface hardness is not lowered, which is preferable. Moreover, if the content rate of an aromatic (meth) acrylate unit is the range of 20 to 70 weight%, it is still more preferable from expressing high surface hardness, maintaining transparency further.

  The surface hardness improver (B) may contain other monomer units other than the aromatic (meth) acrylate unit and the methyl methacrylate unit, if necessary. Examples of other monomers constituting other monomer units include methacrylates such as ethyl methacrylate, butyl methacrylate, propyl methacrylate, 2-ethylhexyl methacrylate; methyl acrylate, ethyl acrylate, butyl acrylate, propyl acrylate, 2- Acrylates such as ethylhexyl acrylate and glycidyl acrylate; vinyl cyanide monomers such as acrylonitrile and methacrylonitrile; diene monomers such as butadiene, isoprene and dimethylbutadiene; vinyl ether ethers such as vinyl methyl ether and vinyl ethyl ether Body; carboxylic acid vinyl monomers such as vinyl acetate and vinyl butyrate; olefin monomers such as ethylene, propylene and isobutylene; acrylic acid, methacrylic acid and male Ethylenically unsaturated carboxylic acid monomers such as acid and itaconic acid; vinyl halide monomers such as vinyl chloride and vinylidene chloride; maleimides such as maleimide, N-phenylmaleimide, N-cyclohexylmaleimide and N-methylmaleimide Monomers; Examples include cross-linking agents such as allyl (meth) acrylate, divinylbenzene, and 1,3-butylene dimethacrylate. Of these, methacrylate, acrylate, and vinyl cyanide monomer are preferable, and acrylate is more preferable from the viewpoint of suppressing thermal decomposition of the surface hardness improver (B). These monomers can be used alone or in combination of two or more.

  When other monomer units are contained, the constituent monomers of the surface hardness improver (B) are aromatic (meth) acrylate units of 5-79.9% by weight, methyl methacrylate units of 20-94.9% by weight. And other monomer units in the range of 0.1 to 10% by weight.

  As a polymerization method of the monomer for obtaining the surface hardness improver (B), a known method such as an emulsion polymerization method, a suspension polymerization method, a solution polymerization method, a bulk polymerization method, or the like can be used. A suspension polymerization method and a bulk polymerization method are preferable, and a suspension polymerization method is more preferable. Further, additives necessary for the polymerization can be appropriately added as necessary, and examples thereof include a polymerization initiator, an emulsifier, a dispersant, and a chain transfer agent.

  The weight average molecular weight of the surface hardness improver (B) is 5,000 to 30,000. When the weight average molecular weight is in the range of 5000 to 30000, the compatibility with the polycarbonate resin (A) is good, and the effect of improving the surface hardness is excellent. In addition, Preferably it is the range of 10,000-25000.

The weight average molecular weight is measured using gel permeation chromatography (GPC), and the detailed conditions are as follows:
As a GPC column, PLGEL 5 μm MIXED-C manufactured by Agilent Technologies was used, and THF was used as a mobile phase.

  The ratio of the surface hardness improver (B) used is in the range of 25 to 65% by weight based on the resin component comprising the polycarbonate resin (A) and the surface hardness improver (B). If the proportion of the surface hardness improver (B) used is less than 25% by weight, the effect of improving the surface hardness is lowered, and if it exceeds 65% by weight, the heat resistance and transparency are lowered. More preferably, it is in the range of 35 to 55% by weight.

  The antibacterial agent (C) containing glass that elutes silver ions used in the present invention as an essential component 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 (C) is preferably composed of Ag ₂ O in a range of 0.2 to 5% by weight, P ₂ O ₅ in a range of 30 to 80% by weight and ZnO in a range of 30 to 50% by weight. 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, the 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.

  The compounding amount of the antibacterial agent (C) is 0.05 to 1.5 per 100 parts by weight of the resin component consisting of 35 to 75% by weight of the polycarbonate resin (A) and 25 to 65% by weight of the surface hardness improver (B). Parts by weight. 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, when the amount exceeds 1.5 parts by weight, the transparency is impaired. More preferably, it is the range of 0.1-1.0 weight part.

  Furthermore, various resins, antioxidants, fluorescent brighteners, pigments, dyes, carbon black, fillers, mold release agents, ultraviolet absorbers are added to the polycarbonate resin composition of the present invention within the range not impairing the effects of the present invention. , Antistatic agents, rubber, softeners, spreading agents (liquid paraffin, epoxidized soybean oil, etc.), flame retardants, additives such as organic metal salts, polytetrafluoroethylene resin for preventing dripping, etc. .

  Examples of the various resins include polystyrene, high impact polystyrene, ABS, AES, AAS, AS, acrylic resin, polyamide, polyethylene terephthalate, polybutylene terephthalate, polyarylate, polysulfone, and polyphenylene sulfide resin. Or you may use together by 2 or more types.

  Examples of the antioxidant include phosphorus antioxidants and phenolic antioxidants. Of these, hindered phenolic antioxidants are preferably used. For example, pentaerythrityl-tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], thiodiethylene-bis [ Examples include 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 include Irganox 1076 manufactured by Ciba Specialty Chemicals.

  As a compounding quantity of a hindered phenolic antioxidant, it is 0.05-1. Per 100 weight part of resin components which consist of polycarbonate resin (A) 35-75 weight% and surface hardness improver (B) 25-65 weight%. 0 weight part is preferable, More preferably, it is the range of 0.1-0.8 weight part.

  EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples. In the examples, “parts” and “%” are based on weight unless otherwise specified.

Details of the raw materials used are as follows.
Polycarbonate resin (A):
Polycarbonate resin synthesized from bisphenol A and phosgene (manufactured by Sumika Stylon Polycarbonate, Caliber 200-20, viscosity average molecular weight 19000, hereinafter abbreviated as “PC”)
Surface hardness improver (B):
Copolymer of aromatic (meth) acrylate unit and methyl methacrylate unit (Metbrene H-880 manufactured by Mitsubishi Rayon Co., Ltd., weight average molecular weight 10,000,
Hereinafter abbreviated as “surface hardness improver”)
Antibacterial glass (C):
KM10D manufactured by Sinanen Zeomic (hereinafter abbreviated as “antibacterial agent”)
Antioxidant:
Irganox 1076 (hereinafter abbreviated as AO) manufactured by Ciba Specialty Chemicals

  In the blending ratios shown in Tables 1 and 2, each of the above raw materials was put into a tumbler and dry mixed for 4 minutes, and then a twin screw extruder (L / D = 42, Φ = 37 mm, KTX-37 manufactured by Kobe Steel) ) Was melt kneaded at a melting temperature of 240 ° C. to obtain pellets of various polycarbonate resin compositions.

(Clouding rate)
The pellets of the various resin compositions obtained above were each dried at 100 ° C. for 6 hours, and then set at a set temperature of 260 ° C. and an injection pressure of 1600 kg / cm ² using an injection molding machine (Japan Steel Works J-100E-C5). A test piece for transparency evaluation (150 × 90 × 3.0 mm) was prepared.
Using the obtained test piece, the haze value (H) was determined with a haze meter (HM150, manufactured by Murakami Color Research Laboratory Co., Ltd.) in accordance with JIS K7361. The haze value (H) was calculated according to the following formula.
Haze value H (%) = (diffuse transmittance Td / total light transmittance Tt) × 100
A haze value (H) of less than 7.0% was considered good.

(Heat-resistant)
The deflection temperature under load at 23 ° C. was measured according to ISO 75-2. 90 ° C. or higher was considered good.

(Pencil hardness)
The pellets of the various resin compositions obtained above were each dried at 100 ° C. for 6 hours, and then set at a set temperature of 260 ° C. and an injection pressure of 1600 kg / cm ² using an injection molding machine (Japan Steel Works J-100E-C5). A test piece for transparency evaluation (150 × 90 × 2.0 mm) was prepared.
Using the obtained test piece, the pencil hardness at which no scratches were observed on the surface of the test piece was determined with a pencil hardness measuring machine (Pencil scratch coating film hardness tester manufactured by Toyo Seiki Co., Ltd.) according to JISK5600-5-4. . A pencil hardness of HB or higher was considered good.

(Antibacterial)
The antibacterial test was conducted 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 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 flat plate test piece made of the resin composition not containing the antibacterial agent (B) of the present invention is x. x / y) (hereinafter abbreviated as antibacterial activity value) was 2.0 or more as good (◯), and less than 2.0 as bad (x).
Further, except for changing Escherichia coli to Staphylococcus aureus, the antibacterial activity test was carried out under the same operation and conditions as described above, the antibacterial activity value was obtained, and evaluated according to the same criteria. The respective results are shown in Tables 1 and 2.

判定： ○： 良好 ×：不良

Judgment: ○: Good ×: Bad

判定： ○： 良好 ×：不良

Judgment: ○: Good ×: Bad

As shown in Examples 1 to 4, those satisfying the constituent requirements of the present invention satisfied the required performance.
On the other hand, as shown in Comparative Examples 1 to 4, those that do not satisfy the constituent requirements of the present invention have the following drawbacks.
In Comparative Example 1, the pencil hardness was poor when the amount of the surface hardness improver was less than the specified amount.
Comparative Example 2 was a case where the blending amount of the surface hardness improver was larger than the prescribed amount, and the heat resistance and the haze ratio were poor.
In Comparative Example 3, the antibacterial property was poor when the blending amount of the antibacterial agent was less than the specified amount.
In Comparative Example 4, the amount of antibacterial agent was greater than the specified amount, and the haze value was poor.

Claims (3)

Antibacterial agent (C) 0.05 containing glass eluting silver ions per 100 parts by weight of resin component consisting of 35 to 75% by weight of polycarbonate resin (A) and 25 to 65% by weight of surface hardness improver (B) 0.05 A polycarbonate resin composition containing ~ 1.5 parts by weight, the surface hardness improver (B),
A copolymer comprising 5 to 80% by weight of aromatic (meth) acrylate units and 20 to 95% by weight of methyl methacrylate units, and the weight average molecular weight of the copolymer being 5000 to 30000 A polycarbonate resin composition.   The polycarbonate resin composition according to claim 1, wherein the resin component comprises 45 to 65% by weight of a polycarbonate resin (A) and 35 to 55% by weight of a surface hardness improver (B).   The polycarbonate resin composition according to claim 1, wherein the shape of the glass eluting silver ions contained in the antibacterial agent (C) is a polyhedron.