JPH06240125A - Antimicrobial polycarbonate resin composition - Google Patents

Abstract

PURPOSE:To obtain the subject composition, excellent in thermal stability and impact resistance and useful as daily sundries, sanitary materials, etc., by blending a thermoplastic resin consisting essentially of a polycarbonate resin with antimicrobial calcium phosphates containing antimicrobial metallic ions supported thereon and a phosphorus-based stabilizer. CONSTITUTION:This resin composition is obtained by blending (A) 100 pts.wt. thermoplastic resin containing an aromatic polycarbonate resin, composed of a dihydric phenol (preferably bisphenol A) and a carbonate precursor (e.g. phosgene) and having 18000-40000 viscosity-average molecular weight and/or <=50wt.% polyester resin, etc., with (B) 0.1-5 pts.wt. (preferably 0.5-2 pts.wt.) antimicrobial calcium phosphates composed of hydroxyapatite, etc., containing antimicrobial metallic ions (preferably ions such as silver or copper) supported in an amount of preferably 0.0001-5wt.% based on the calcium phosphate and (C) 0.01-1 pt.wt. (preferably 0.02-0.2 pt.wt.) phosphorus-based stabilizer (preferably trimethyl phosphgte).

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to an antibacterial polycarbonate resin composition. More specifically, it relates to an antibacterial polycarbonate resin composition having excellent heat stability.

[0002]

2. Description of the Related Art Conventionally, as an antibacterial thermoplastic resin composition, one in which a silver-based zeolite is kneaded with a polyolefin as a base resin is known, and it is used for daily sundries and household electric appliances. However, such an antibacterial product has an operating temperature limited by the heat resistant temperature of the base resin,
There is a problem that it cannot be used in an environment exposed to high temperatures. In order to solve this problem, an attempt was made to use a polycarbonate resin having excellent heat resistance as a base resin. However, when a silver-based zeolite is kneaded into a polycarbonate resin, the molecular weight of the polycarbonate resin is lowered, and silver is generated due to decomposition during molding, so that a practical antibacterial material cannot be obtained.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide an antibacterial polycarbonate resin composition having excellent heat stability. The present inventor has conducted extensive studies to achieve the above-mentioned object, and as a result, the use of antibacterial calcium phosphates carrying an antibacterial metal ion as an antibacterial agent, and if a phosphorus-based stabilizer is used in combination, The present invention has been accomplished by finding that an antibacterial polycarbonate resin composition having excellent heat stability can be obtained.

[0004]

According to the present invention, 100 parts by weight of a thermoplastic resin mainly composed of a polycarbonate resin is loaded with 0.1-5 parts by weight of antibacterial calcium phosphates in which antibacterial metal ions are supported and phosphorus-based stable. The present invention relates to an antibacterial polycarbonate resin composition containing 0.01 to 1.0 part by weight of an agent.

The thermoplastic resin mainly composed of a polycarbonate resin in the present invention is selected from a polycarbonate resin or 50% by weight or more of a polycarbonate resin, a polyester resin, a polyolefin resin, a vinyl resin and a rubber-reinforced vinyl resin. It is a resin mixture comprising at least 50% by weight of a thermoplastic resin.

The polycarbonate resin used in the present invention has a viscosity average molecular weight of 1 derived from dihydric phenol.
4,000-100,000, preferably 18,000
~ 40,000 aromatic polycarbonate resin,
It is usually produced by reacting a dihydric phenol with a carbonate precursor by a solution method or a melting method. Typical examples of the dihydric phenol include 2,2-bis (4-hydroxyphenyl) propane (hereinafter referred to as bisphenol A), 1,1
-Bis (4-hydroxyphenyl) ethane, 2,2-bis (4-hydroxy-3,5-dimethylphenyl) propane, 2,2-bis (4-hydroxy-3,5-dibromophenyl) propane, 2 , 2- (4-hydroxy-3
-Methylphenyl) propane, bis (4-hydroxyphenyl) sulfone and the like. Preferred dihydric phenols are bis (4-hydroxyphenyl) alkane compounds, and bisphenol A is particularly preferred.

Examples of the carbonate precursor include carbonyl halide, diaryl carbonate, haloformate and the like, and specific examples include phosgene, diphenyl carbonate and dihaloformate of dihydric phenol. In producing the polycarbonate resin, the dihydric phenol may be used alone or in combination of two or more kinds. Further, an appropriate molecular weight modifier, a branching agent, a catalyst for accelerating the reaction and the like can be used, and two or more kinds of the obtained polycarbonate resins can be mixed.

The polyester resin used in the present invention is a homo- or copolymer obtained by a condensation reaction of a dicarboxylic acid component and a diol component. Examples of the dicarboxylic acid component include aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid and naphthalenedicarboxylic acid, aliphatic dicarboxylic acids such as succinic acid, oxalic acid, adipic acid and sebacic acid, and ester-forming derivatives thereof. Examples of the diol component include ethylene glycol, 1,4-butanediol, trimethylene glycol, pentamethylene glycol, hexamethylene glycol, neopentyl glycol, diethylene glycol, and ester-forming derivatives thereof. Particularly preferred polyester resins are polyethylene terephthalate and polybutylene terephthalate, the molecular weights of which are not particularly limited, but those having an intrinsic viscosity of about 0.4 to 1.2 measured at 25 ° C. using o-chlorophenols as a solvent are preferable. . Examples of the polyolefin resin include polyethylene resin, polypropylene resin, ethylene-propylene copolymer and the like.

Examples of the vinyl resin used in the present invention include vinyl cyanide compounds such as acrylonitrile, methacrylonitrile and chloroacrylonitrile, and aromatic compounds such as styrene, α-methylstyrene, p-methylstyrene, alkoxystyrene and halogenated styrene. Examples thereof include homo- or copolymers of vinyl compounds, acrylic acid esters such as methyl acrylate, ethyl acrylate, butyl acrylate, octyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate and octyl methacrylate. Further, the rubber-reinforced vinyl-based resin is a graft copolymer obtained by copolymerizing at least one kind of the vinyl-based monomer as described above in the presence of the diene-based rubber, and as the diene-based rubber, polybutadiene and isoprene butadiene are used. Examples thereof include styrene copolymers and butadiene-acrylonitrile copolymers. These thermoplastic graft copolymers may be produced by any polymerization method such as bulk polymerization, solution polymerization, suspension polymerization and emulsion polymerization, and the grafting method may be single-stage grafting or multi-stage grafting. Further, it may be a mixture with a polymer containing only a graft component produced as a by-product during the production. Further, it may be a mixture of two or more thermoplastic graft copolymers.

Antibacterial calcium phosphate used in the present invention
Tricalcium phosphate, Ca_Ten(PO _Four )₆(OH)₂Indicated by
The hydroxyapatite or part of its OH groups
Calcium of apatite substituted with fluorine or iodine
Stabilization by replacing some of the ions with antibacterial metal ions
The molecular structure of these calcium phosphates.
Antibacterial phosphorus with antibacterial metal ions incorporated in the pores
It is a calcium acid salt.

The antibacterial metal ions mentioned here are ions of silver, copper and zinc. The amount of antibacterial metal ions supported on the antibacterial calcium phosphates is 30% by weight or less, and preferably 0.0001 to 5% by weight, based on the calcium phosphates. The amount of the antibacterial calcium phosphates used is 0.1 to 5 parts by weight, preferably 0.5 to 2 parts by weight, based on 100 parts by weight of the resin. When the amount used is less than 0.1 parts by weight, sufficient antibacterial properties cannot be obtained, and even when it is more than 5 parts by weight, the antibacterial properties are not further improved and mechanical properties are deteriorated.

The phosphorus-based stabilizer used in the present invention is an ester or partial ester of phosphoric acid, phosphorous acid or phosphonic acid, an alkaline earth metal salt, a zinc group metal salt and the like. For example, trimethyl phosphate, tributyl phosphate, tricresyl phosphate, triphenyl phosphate, trichlorophenyl phosphate, triethyl phosphate, diphenyl cresyl phosphate, diphenyl monoorthoxenyl phosphate, tributoxyethyl phosphate, phenylphosphonic acid dimethyl ester, 3,
5-ditert-butyl-4-hydroxybenzylphosphonic acid dimethyl ester, dibutyl phosphate, dioctyl phosphate, diisopropyl phosphate,
Triphenyl phosphite, trimethyl phosphite,
Tricresyl phosphite, diphenylnonylphenyl phosphite, tris (nonylphenyl) phosphite, triisooctyl phosphite, diphenylisodecyl phosphite, triisodecyl phosphite, trioleyl phosphite, trilauryl trithiophosphite, diisodecyl Examples thereof include phosphite, dilauryl phosphite, dioleyl phosphite, tris (2,4-ditertiarybutylphenyl) phosphite, and distearyl penateristhitol diphosphite.
Of these, trimethyl phosphate, tris (nonylphenyl) phosphite, and distearyl pentaerythritol diphosphite are preferable. The amount of phosphorus stabilizer used is
The amount is 0.01 to 1.0 part by weight, preferably 0.02 to 0.2 part by weight, based on 100 parts by weight of the resin. Usage is 0.
If it is less than 01 parts by weight, sufficient thermal stability cannot be obtained,
If it is more than 1.0 part by weight, resin deterioration will occur.

Any method or device can be used to produce the composition of the present invention. For example, the above-mentioned necessary components are extruders,
Examples thereof include a method of mixing with a Banbury mixer, a heating roll, etc., a method of directly molding with an injection molding machine, etc., and a method of previously mixing two arbitrary components and then mixing the remaining components. Further, the composition of the present invention, if necessary, an antioxidant,
Various stabilizers such as ultraviolet absorbers, pigments, dyes, dispersants and the like can be added.

[0014]

EXAMPLES The present invention will be further described with reference to the following examples. In addition, the part in an Example is a weight part and evaluation was based on the following method.

(A) Thermal stability: During the injection molding of a test piece for measuring impact strength and a test piece for measuring a molecular weight using pellets, the molding was once stopped, allowed to remain in the cylinder for 10 minutes, and then restarted. The impact strength of the test piece before and after the retention and the decrease in the molecular weight (viscosity average molecular weight) from the pellets before and after the retention were shown. Impact strength was measured by ASTM D-256 (with Izod notch, thickness 1/8 inch).

(B) Antibacterial activity (shake flask method): Escherichia coli was suspended in a phosphate buffer solution (pH = 7.0) to prepare 10 ml of a solution having a bacterial count of about 1.0 × 10 ⁵ cells / ml. 10 mm
Put 30 x 10mm x 2mm test pieces in 2 at 25 ℃
The cells were shaken and cultivated for 4,48 hours to measure the number of bacteria. Sterilization rate is 9
9% or more was evaluated as ◯, and 99% or less was evaluated as x.

[0017]

Examples 1 to 7 and Comparative Examples 1 to 7
C (polycarbonate resin), ABS (ABS resin), PBT (polybutylene terephthalate resin), antibacterial agent and stabilizer are mixed, and 30 mmφ vent type extruder [VSK manufactured by Nakatani Co., Ltd.]
-30] and melt-extrude at a cylinder temperature of 240 to 250 ° C. to form pellets.
Dry at 0 ° C for 5 hours with a hot air circulation dryer, and use an injection molding machine [T-series Model 150D manufactured by Fanuc Co., Ltd.] to obtain a cylinder temperature of 250 to 270 ° C and a mold temperature of 70 ° C.
A test piece for evaluation was obtained. The evaluation results are shown in Table 1.

The symbols for resins, antibacterial agents and stabilizers in Table 1 are as follows. PC: Polycarbonate resin [Teijin Kasei Co., Ltd. Panlite L-1225 WP, viscosity average molecular weight 22,500] PBT: Polybutylene terephthalate resin [Teijin Co., Ltd.
TRB-J] ABS: ABS resin [Santak UT- manufactured by Mitsui Toatsu Chemicals, Inc.]
61] A-1: Apacider A25 [manufactured by Sangi Co., Ltd. (silver 2% by weight, zinc 0.6 to 0.9% by weight)] A-2: Apacider AW [manufactured by Sangi Co., Ltd. (silver 2% by weight,
Zinc 0.6 to 0.9% by weight)] P-1: trimethyl phosphate P-2: distearyl pentaerythritol diphosphite

[0019]

[Table 1]

[0020]

INDUSTRIAL APPLICABILITY The antibacterial polycarbonate resin of the present invention is excellent in thermal stability, has a small decrease in molecular weight, does not generate silver during molding, can be used in various materials, and needs to prevent the generation and growth of bacteria. It can be used for all materials. In particular, it is useful for daily sundries, medical / sanitary materials, and the like that require heat resistance and impact resistance, and the industrial effects produced by it are exceptional.

Claims (1)

[Claims] 1. An antibacterial calcium phosphate having an antibacterial metal ion supported on 100 parts by weight of a thermoplastic resin mainly composed of a polycarbonate resin, 0.1 to 5 parts by weight, and a phosphorus stabilizer of 0.01 to 1.0. An antibacterial polycarbonate resin composition containing parts by weight.