JPH07331017A - Antimicrobial resin composition - Google Patents

Abstract

PURPOSE:To produce an antimicrobial resin molded product useful for decorative laminates and excellent in resistances to weathering discoloration, chemicals and staining by co-extruding an acrylic resin containing an antimicrobial agent as a surface layer together with the other layers. CONSTITUTION:This antimicrobial resin molded product has the surface layer of an acrylic resin from methyl methacrylate or the like, containing an antimicrobial agent such as bis(2-pyridylthio-1oxide)zinc, preferably in an amount of 0.1-5 pts.wt. per 100 pts.wt. of the acrylic resin. The base resin to which the surface layer is laminated is preferably an acrylic, polycarbonate, vinyl chloride or ABS resin.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a coextruded resin molded product having antibacterial properties.

[0002]

2. Description of the Related Art In recent years, decorative columns have been used as indoor materials for buildings,
Extruded products of thermoplastic resins such as vinyl chloride resin are widely used as materials such as handrails. However, these resins have drawbacks such as easy discoloration due to weathering, easy stains, and hard to remove stains.

On the other hand, a resin molded product obtained by coextruding an acrylic resin on the surface layer is excellent in weathering discoloration, chemical resistance and stain resistance. Further, by coextruding an acrylic resin with an ABS resin or the like, it is also used for the purpose of imparting weatherability and at the same time, imparting a design property of providing a deep appearance.

[0004]

The above-mentioned resin material used indoors has a large chance of coming into contact with the human body in daily life, and therefore there is a high risk of infection when bacteria propagate. For example, handrails made of vinyl chloride resin produced by extrusion molding are often used at stations, hospitals and the like, but there are problems in hygiene because an unspecified number of people directly touch the handrails. Therefore, an antibacterial agent is added to vinyl chloride resin to impart antibacterial properties.

However, due to weathering discoloration resistance and stain resistance, even if a common acrylic resin is co-extruded on the surface layer, no antibacterial property is exhibited, and therefore, there is an increasing demand for imparting antibacterial performance to the surface acrylic resin layer. In addition, since it is sufficient to impart antibacterial properties only to the surface layer, it is much more economical to impart antibacterial properties only to the acrylic resin layer than to add an antibacterial agent to the entire resin.

Further, ABS resin is widely used for housings and miscellaneous goods of home electric appliances, and in this case also, there are many occasions where it comes into contact with daily life, and there is a risk of infection caused by this. Therefore, it is effective to coextrude an acrylic resin having antibacterial properties on the surface layer.

[0007]

The gist of the present invention is a coextruded resin molded product, characterized in that the surface layer is made of an acrylic resin to which an antibacterial agent is added. It is in.

The acrylic resin used in the present invention is
Although not particularly limited, methyl methacrylate, ethyl methacrylate, propyl methacrylate,
Butyl methacrylate as a main raw material, if necessary, an acrylic ester having an alkyl group having 1 to 8 carbon atoms, vinyl acetate, vinyl chloride, styrene, acrylonitrile,
A homopolymer or copolymer obtained by using methacrylonitrile or the like as a copolymerization component is used. Further, as an acrylic resin having excellent weather resistance and impact resistance, for example, Japanese Patent Publication Nos. 62-19309 and 63-63.
Acrylic resin-based multi-layered polymers such as those disclosed in JP-A-20459 and JP-A-63-77963 are used.

As the antibacterial agent added to the acrylic resin, bis (2-pyridylthio-1-oxide) zinc is preferred because of its high safety in view of toxicity to the human body. "Hokuside-ZPT" manufactured by Hokuko Kagaku Kogyo Co., Ltd.,
Or “Bioside 9” manufactured by Taisho Technos Co., Ltd.
60 "and the like.

The addition amount of the antibacterial agent is not particularly limited, but from the viewpoint of antibacterial property, it is 0.05 parts by weight or more, moldability,
From the viewpoint of appearance and economy, it is desirable that the amount is less than 20 parts by weight, preferably 0.1 part by weight or more and less than 5 parts by weight.

In the present invention, as the base resin on which the acrylic resin surface layer is laminated, known thermoplastic resins can be used, but acrylic resins, polycarbonate resins, vinyl chloride resins and ABS resins are preferred.

The antibacterial resin molded product of the present invention can be obtained by a coextrusion molding method. The co-extrusion molding method is a method in which a plurality of extrusion-molded resins are adhered in a molten state to form a multi-layer. There are a method called "manifold die" in which a plurality of resin layers are made into a sheet and then bonded, and a method called a feed block die in which a plurality of resins are spread and then spread into a sheet shape, and either method can be used.

In the present invention, the acrylic resin constituting the surface layer contains, in addition to the antibacterial agent, a general compounding agent, if necessary,
For example, stabilizers, lubricants, processing aids, plasticizers, impact resistance aids,
A foaming agent, a filler, a colorant, an ultraviolet absorber, an antifungal agent and the like can be included.

[0014]

The present invention will be described in more detail with reference to the following examples. In the examples, "parts" means "parts by weight". [Examples 1 to 4] [Comparative Examples 1 to 9] As a base material for a coextrusion molded article, 100 parts of polyvinyl chloride resin having an average degree of polymerization of 1000 and dioctyl phthalate 15 were added.
Parts, barium-zinc stabilizer 2.5 parts, phosphite stabilizer 0.5 parts, and epoxidized soybean oil 3 parts were blended using a Henschel mixer to obtain a powdery vinyl chloride resin composition. .

As an acrylic resin, 100 parts of "Hipet (trade name) HBS-001" manufactured by Mitsubishi Rayon Co., Ltd., and "Hokside-ZPT" manufactured by Kitako Chemical Co., Ltd. (trade name) as an antibacterial agent are shown in Table 1. 45m
Various evaluations were performed by shaping the pellets with an m twin-screw extruder.

Separately, as comparative examples, antibacterial agents manufactured by Taisho Technos Co., Ltd., organic nitrogen-sulfur antibacterial agents under the trade names "Bioside 905A" and "Bioside 871", and organic nitrogen-sulfur halogen antibacterial agents "Bioside" 84
3] and Kanebo Co., Ltd., which is a zeolite-silver composite antibacterial agent
13 kinds of acrylic resin compositions shown in Table 1 were obtained in the same manner for the product using the trade name "BACTEKILLER" and the simple substance of "HIPET HBS-001" which does not contain an antibacterial agent.

[0017]

[Table 1]

The vinyl chloride resin composition and the acrylic resin composition were coextruded under the following conditions to obtain 13 kinds of molded articles. As a co-extrusion device, a profile extrusion die equipped with a 45 mm twin-screw extruder and a 30 mm single-screw extruder is used,
Copolymerization was carried out by supplying the vinyl chloride resin composition of the base material with a 45 mm twin-screw extruder and the acrylic resin composition of the surface layer with a 30 mm single-screw extruder to perform coextrusion molding.
A sheet-shaped molded product having a thickness of 2 mm and a vinyl chloride resin layer of 8.0 mm was obtained. The extrusion temperature was 200 ° C. for the twin-screw extruder and 220 ° C. for the single-screw extruder. In Comparative Examples 5 to 8 using "Bioside 843" and "Bacte Killer", the appearance of the molded product was deteriorated due to the discoloration.

The obtained antibacterial co-extruded resin molded product was subjected to an antibacterial property evaluation test by a contact method and an agar plate method. [Contact method] Echerichia coli as bacteria
IFO 12734 and Staphylococcus
aureus ATTC 11522 strain was used.
Each of these strains was inoculated into trypto soya broth medium, shake-cultured at 30 ° C. for 18 hours, and then centrifuged.
After washing three times with sterile physiological saline, it was diluted to obtain a bacterial suspension.

200 μl of the above-mentioned bacterial suspension was dispensed into a petri dish, and the coextruded resin molded product cut into a square of 4 cm × 4 cm was placed so that the acrylic resin layer was on the lower side. It was crimped so as to come into contact with. The petri dish was covered with a lid, and after culturing at 30 ° C. for 24 hours, the number of viable cells in the culture was measured by the pour method. The results are shown in Tables 2 and 3.

Escherichia coli IFO
For 12734, Examples 1 and 2 and Comparative Example 4
, Staphylococcus aureus A
Regarding TTC11522, antibacterial properties were observed in Examples 1, 2, 3, 4 and Comparative Examples 3, 4.

[0022]

[Table 2]

[0023]

[Table 3]

Escherichia col as the fungus body
i IFO 12734 was used. The above-mentioned base strain was inoculated into trypto soya broth medium, shake-cultured at 30 ° C. for 18 hours, and then diluted 100 times with sterile physiological saline to obtain a bacterial suspension. 10 ml of heart infusion agar medium was poured into a sterilized petri dish, and after solidification, 4 cm x
The sample cut into a 4 cm square was placed with the acrylic resin layer facing up.

Then, the INT reagent (2- (P-
Indophenyl) -3- (P-nitrophenyl) -5-
Phenyltetrazolium chloride) 100 ppm,
10 ml of a heart infusion agar medium supplemented with 0.5% of the above-mentioned bacterial suspension was injected and overlaid. And 30 ℃
After culturing for 3 days in a thermostatic chamber, the state of color development by the INT reagent was observed. The results are shown in Table 4.

[0026]

[Table 4]

As shown in Table 4, in the examples, no growth of bacteria (red coloration) was observed on the surface of the sample, and a zone of inhibition was also observed around the sample. Bacterial growth (red coloring) was observed on the entire surface of the sample. Example 1
It was also found that Example 2 has a strong antibacterial action both in the contact method and the agar plate method.

[0028]

EFFECT OF THE INVENTION The coextruded resin product of the present invention has antibacterial properties and is also excellent in weathering discoloration resistance, chemical resistance, stain resistance and the like.

Claims (2)

[Claims] 1. An antibacterial resin molded product, which is a coextruded resin molded product, wherein the surface layer is made of an acrylic resin to which an antibacterial agent is added. 2. The antibacterial agent is bis (2-pyridylthio-1-).
Oxide) zinc, The molded antibacterial resin product according to claim 1.