JPH08253759A - Antibacterial sealant composition - Google Patents

Abstract

PURPOSE: To obtain an antibacterial sealant composition made proof for a long time against attack by mildews by adding a specified substance to a sealant based on an organopolysiloxane. CONSTITUTION: An antibacterial sealant composition is prepared by adding a photo-semiconductor and a conductive powder to a sealant based on an organopolysiloxane. The photo-semiconductors used are ones having a forbidden gap of 0.5-5eV and are exemplified by metal oxides, metal chalcogenides, group IV elements, group III-IV element compounds, and organic semiconductors. Among them, metal oxides, more particularly titanium oxides, are desirable. The amount of the photo-semiconductor added is preferably 0.1-50 pts.wt. per 100 pts.wt. resin. Example of the conductive powders used include carbon powders (fibers) and metallic powders (fibers). Among them, tin oxides are desirable. The amount of the conductive powder added is desirably 0.01-50 pts.wt. per 100 pts.wt. resin.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an antibacterial sealant composition capable of preventing deterioration due to mold over a long period of time.

[0002]

2. Description of the Related Art In recent years, sealing materials have been widely used for the purpose of filling joints and gaps of various construction members with watertightness and airtightness in joints. Among them, a sealing material containing a modified silicone as a main component is excellent in weather resistance and paintability and is used as a jointing agent for interiors and exteriors of buildings (Japanese Patent Laid-Open No. 2-306907). Above all,
Since the sealing material containing organopolysiloxane as a main component is excellent in weather resistance, durability, and dimensional stability, it is often used in bathrooms, bathrooms, etc. around water as a building member. However, when the sealing material is supplemented with nutrients due to the adhesion of dirt such as dust, oil and fat, and human scale,
Especially around water, a moderate temperature and humidity environment is prepared, so that molds grow easily, and the surface part is discolored due to mold generation, and there is deterioration such as peeling between the sealing material and building members and cracks. Occurred, and there was a problem of causing serious damage such as damage and water leakage.

Therefore, improvements have been made by adding an organic antibacterial agent to the sealing material to impart antibacterial properties, etc. However, the antibacterial agent flows out at places where water is likely to splash and effectively prevents the generation of mold. I couldn't. Therefore, there has been a demand for a technique capable of maintaining the antibacterial effect and protecting the sealing material from deterioration due to the generation of mold over a long period of time.

JP-A-2-306907 discloses an antibacterial property obtained by simultaneously adding parachlorometaxylenol and bis (2-pyridylthio-1-oxide) zinc salt to a sealing material containing a modified silicone as a main component. The technique of giving is disclosed. However, in this method, it is necessary to make the two compounds as fine powders as possible, and these compounds are expensive and not easily available.
The antibacterial property was not long-lasting.

[0005]

SUMMARY OF THE INVENTION In view of the above, it is an object of the present invention to provide an antibacterial sealing material composition having an antibacterial performance for a long period of time.

[0006]

The gist of the present invention is to construct an antibacterial sealing material composition by adding a photosemiconductor and a conductive powder to a sealing material containing organopolysiloxane as a main component. Exist in.

The sealant used in the present invention is a polymer silicon compound having a silicon-oxygen bond (siloxane bond) as a skeleton, and particularly, the silicon atom has an organic group such as a methyl group or a phenyl group. Is the main component of the organopolysiloxane having both inorganic and organic properties.

The above-mentioned organopolysiloxane is obtained by polymerizing an organosiloxane which is synthesized by mixing organochlorosilane or alkoxysilane alone or in an appropriate ratio and dehydrating and condensing silanol produced by hydrolysis with water. is there. Examples of the above-mentioned organosiloxane include a quadruple cyclic compound (octamethylcyclotetrasiloxane) synthesized from dimethyldichlorosilane, which is generally called D4.

Among them, liquid rubber often used as a sealing material around water is silicone RTV (Room).
Also referred to as Temperature Vulcanize) rubber, Si-OH, Si-OR, Si-H, Si
Siloxane having a reactive group such as —CH═CH ₂ is crosslinked at room temperature in the presence of a catalyst to form rubber elasticity. There are a condensation type and an addition type due to the crosslinking mechanism. The former is a dehydration condensation reaction between silanols, a dealcoholization reaction between silanols and alkoxysiloxanes, a Si-H reaction with silanols, using a catalyst such as an organic acid metal salt or an organic amine. The latter is a type that crosslinks by a dehydration condensation reaction or the like, and the latter is a type that crosslinks by an addition reaction between an unsaturated group such as a vinyl group or an allyl group and Si—H using a platinum compound as a catalyst.

In general, the sealing material containing organopolysiloxane as a main component is not a material that easily causes mold, but when it is used around water, mold growth is often observed. Most of these molds are because microorganisms adhere to the adhered substances on the surface, for example, dirt such as dust, dust, and dirt, and proliferate, and mycelia penetrate into the material. Molds that occur in the sealing part around water include, for example, Alternaria spp, Cladosporium spp,
Examples include fungi of the genus Urocladium, Exophiala, Rhodotorula and the like.

The photo-semiconductor and conductive powder used in the present invention suppress the growth of these bacteria for a long period of time by the photo-sterilizing action without elution of the drug. The optical semiconductor is not particularly limited as long as it is a semiconductor having a bandgap of 0.5 to 5 eV, and examples thereof include metal oxides such as zinc oxide, titanium dioxide, tungsten oxide, strontium titanate, and ferric oxide. Zinc sulfide, cadmium sulfide,
Metal chalcogenides such as lead sulfide, zinc selenide and cadmium selenide; Group IV elements such as silicon and germanium; Group III-IV compounds such as gallium-phosphorus, gallium-arsenic and indium-phosphorus; polyacetylene, polypyrrole, polythiophene , Organic semiconductors such as polyaniline and polyvinylcarbazole, and the like.
Metal oxides such as titanium dioxide and tungsten oxide are preferably used from a practical viewpoint, and titanium dioxide is more preferably used because it is easily available and used. The above optical semiconductors may be used alone or in combination of two or more.

The type of titanium dioxide is not particularly limited, and examples thereof include amorphous, rutile type, and anatase type. The anatase type is the most superior in terms of antibacterial activity, and anatase type titanium dioxide is used. Is the most effective. Titanium dioxide, which is generally used as a white pigment, is not preferable because it often has a photocatalytic action because it is coated with alumina or silica. If the amount of the optical semiconductor added is less than 0.1 parts by weight with respect to 100 parts by weight of the resin, the antibacterial activity is weak, and if it exceeds 50 parts by weight, the physical properties and appearance of the sealing material may be impaired. Therefore, 0.1 to 50 parts by weight is preferable.

The above-mentioned electroconductive powder is, for example, carbon powder (fiber) or metal powder (fiber) generally used for imparting electroconductivity. Examples of such electroconductive powder include carbon black, gold, Examples thereof include silver, copper, platinum, iron, aluminum, nickel, palladium, tin oxide and indium oxide. Among them, tin oxide is preferably used. Further, a conductor may be coated on the surface by using a non-conductor as a core material. Examples of such particles include silver-plated fine particles, aluminum-coated fine particles, and barium sulfate fine particles whose surface is coated with tin oxide. The above conductive powder may be used alone or in combination of two or more. The amount of conductive powder added is
If the amount is less than 0.01 parts by weight with respect to 100 parts by weight of the resin, the improvement of the optical semiconductor effect due to the addition is not observed, and
If the amount is more than 100 parts by weight, the physical properties and appearance of the sealing material may be impaired, so 0.01 to 50 parts by weight is preferable.

The antibacterial sealant composition of the present invention comprises:
Additives such as commonly used colorants, fillers, plasticizers, flame retardants and antistatic agents can be used.

[0015]

The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

Example 1 40 parts by weight of titanium oxide (anatase type, primary particle size: 0.3 μm), antimony oxide per 100 parts by weight of a commercially available one-pack type RTV silicone rubber (KE-44 manufactured by Shin-Etsu Chemical Co., Ltd.) After adding 20 parts by weight of tin oxide (primary particle size: 0.02 μm), the mixture was mixed with a roll to obtain a stable silicone composition uniformly dispersed. The obtained silicone composition was added to 2
It was applied to a sheet having a thickness of mm, air-dried at room temperature for 1 week, cut into 2 cm squares to prepare a test piece, and the test was conducted by the following method.

Table evaluation test Antibacterial performance test method On the prepared test piece, 0.05% by weight of non-sar LN-1 (manufactured by NOF CORPORATION), 0.05% by weight of non-sar TN-1 (manufactured by NOF CORPORATION) and polypeptone ( (Manufactured by DIFCO)
Place 1 ml of an aqueous solution containing 0.1% by weight and
It was dry day and night. Next, the prepared test piece was placed on a plastic petri dish containing agar, and 50 ml of a sterile aqueous solution having the same composition as the above was used to alter Alterna alte.
Rnata , Cladosporium clados
porioides , Ulocladium atr
a , Rhodotorula rubra , Exoph
One platinum loop of each bacterium of iala jeanselmei was scraped off, and 1 ml of a suspension in which spores were dispersed was sprayed. Then, it put into a thermostat (28 degreeC, 95-100%), and culture | cultivated under a fluorescent lamp for 4 weeks. From the start of the test 7, 14, 21, 2
The growth condition of the mold on the 8th day was judged according to the following criteria. The results are shown in Table 1.

The numbers in Table 1 represent the following states. 1 Mold growth was clearly observed on the test piece, and the growth area exceeded 1/3. 2 Mold growth was observed on the test piece, but the growth area did not exceed 1/3. 3 Mold growth was observed on the test piece. No growth was observed

On- site test A test was conducted on a sealing material portion of a bathroom where mold has already been generated in a general household. That is, the mold-contaminated portion of the bathroom at home was peeled off, and the sealing material obtained in the example was applied to the portion. Use the bathroom in the condition that it is used in everyday life of an ordinary household, and use it in 3, 6, 12, 24
The mold development status was examined on the following month according to the following criteria. The results are shown in Table 2.

The numbers in Table 2 represent the following states. 1 mold was found 2 mold was slightly found 3 mold was not found

Example 2 One-component RTV silicone rubber (KE, manufactured by Shin-Etsu Chemical Co., Ltd., KE
-44) 0.1 parts by weight of titanium oxide (anatase type, primary particle size 0.3 μm) and 0.1 parts by weight of antimony oxide-containing tin oxide (primary particle size 0.02 μm) were added to 100 parts by weight. A silicone composition was obtained in the same manner as in Example 1. A test piece was prepared using the obtained silicone composition and tested. The results are shown in Tables 1 and 2.

Example 3 One-component RTV silicone rubber (manufactured by Shin-Etsu Chemical Co., Ltd., KE
-44) 10 parts by weight of titanium oxide (anatase type, primary particle size: 0.3 μm) and 1 part by weight of barium sulfate fine particles (primary particle size: 0.02 μm) coated with antimony oxide-containing tin oxide were added to 100 parts by weight. A silicone composition was obtained in the same manner as in Example 1 except for the above. A test piece was prepared using the obtained silicone composition and tested. The results are shown in Tables 1 and 2.

Comparative Example 1 Example 1 except that the tin oxide containing antimony oxide was not added.
A silicone composition was obtained in the same manner as in. A test piece was prepared using the obtained silicone composition and tested. The results are shown in Tables 1 and 2.

Comparative Example 2 A silicone composition was obtained in the same manner as in Example 1 except that titanium oxide was not added. A test piece was prepared using the obtained silicone composition and tested. The results are shown in Table 1 and Table 2.
It was shown to.

Comparative Example 3 A silicone composition was obtained in the same manner as in Example 3 except that titanium oxide was not added. A test piece was prepared using the obtained silicone composition and tested. The results are shown in Table 1 and Table 2.
It was shown to.

Comparative Example 4 A test piece was prepared by using a cured product of only the one-pack type RTV silicone rubber (KE-44 manufactured by Shin-Etsu Chemical Co., Ltd.) used in Example 1 and tested. The results are shown in Tables 1 and 2.

[0027]

[Table 1]

[0028]

[Table 2]

[0029]

The antibacterial sealant composition of the present invention comprises:
With the above-mentioned structure, deterioration due to mold can be prevented for a long period of time, and it can be effectively used as a sealing material for the interior and exterior of buildings and around water.

Claims (1)

[Claims] 1. An antibacterial sealant composition comprising a sealant containing organopolysiloxane as a main component, and an optical semiconductor and a conductive powder added thereto.