JPH0776654A - Mildew proofing silicone rubber composition and silicone rubber - Google Patents

Abstract

PURPOSE:To obtain the silicone rubber composition capable of providing stable mildew proofing effects over a long period and free from color change. CONSTITUTION:This composition is obtained by blending (A) 100 pts.wt. of a silicone rubber composition, preferably a room temperature-curable silicone rubber composition consisting of (i) 100 pt.wt. of a diorganopolysiloxane of formula I, formula II, etc. [(n) is integer, preferably of 50-2000; (a+b)=n], etc., (ii) 0.2-30 pts.wt. of an organosilicone compound such as methyltrimethoxysilane, (iii) 0-10 pts.wt. of a condensation catalyst with (B) 0.1-10 pts.wt., especially preferably 0.2-5 pts.wt. of an organic mildew proofing agent (preferably parbendazole, 2-methoxycarbonylaminobenzimidazole, etc.) and (C) 0.1-100 pts.wt., especially preferably 0.2-70 pts.wt. of an inorganic antimicrobial agent (especially preferably carrying a silver-based antimicrobial agent on a support).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an antifungal silicone rubber composition capable of giving a silicone rubber having excellent antifungal properties and a silicone rubber.

[0002]

2. Description of the Related Art Conventionally, the problems to be solved by the invention
Room-temperature-curable organopolysiloxane compositions, which are easily cured by moisture to become elastic bodies, are widely used as adhesives, coating materials, electrical insulating sealing materials, and sealing materials for construction. However, when a composition of this kind is used for a long period of time, molds often adhere to the surface of the composition, propagate, and spoil the appearance.

In order to prevent this, some methods are known in which an organic fungicide is added to suppress the growth of fungi. For example, a method of adding 2,3,5,6-tetrachloro-4-methylsulfonylpyridine (JP-A-51-10).
6158), and a method of adding 2- (4-thiazolyl) -benzimidazole (JP-A-54-127960).
JP-A-56-38348), and a method of adding an N-substituted benzimidazolyl carbamate derivative (JP-A-56-38348).
Are known.

However, with these fungicides, it is impossible to prevent the reproduction of all kinds of fungi and maintain their effects for a long period of time, and it is impossible to suppress the growth of the mold for a long period of time. It was In addition, the surface of the mold-grown silicone rubber is discolored, stains cannot be removed by washing, etc., resulting in poor appearance.

As a result of various studies on the cause of the problem, the present inventor has found that the mold mycelia entering the silicone rubber is the main cause of discoloration, which is an organic substance that is incompatible with the silicone rubber over time. It was found that the fungicide bleeds out on the rubber surface.

The present invention has been made to solve the above problems, and provides a silicone rubber composition that exhibits stable antifungal properties for a long period of time and that prevents discoloration due to mold growth. And to provide the silicone rubber.

[0007]

Means and Actions for Solving the Problems As a result of intensive studies for achieving the above-mentioned object, the present inventor has found that by combining an organic antifungal agent with an inorganic antibacterial agent, Inorganic antibacterial agents can suppress the growth of mold that has invaded, and the growth of Escherichia coli and staphylococci, which could not be prevented by the use of organic fungicides alone, can be suppressed and stable control can be achieved over a long period of time. The present inventors have completed the present invention by discovering that a silicone rubber exhibiting a mildew effect and having no discoloration due to mildew can be obtained.

Therefore, the present invention provides a silicone rubber composition and a silicone rubber containing an organic antifungal agent and an inorganic antibacterial agent.

The present invention will be described in more detail below. As the organic fungicides used in the present invention, known compounds such as benzimidazole, binazine, methylsulfonylpyridine, and benzimidazolylcarbamate compounds can be used. Specifically, 2- (thiocyanomethylthio) benzimidazole, 4,5,6-tetrachloro-2-trifluoromethylbenzimidazole (TT
FB), 5,6-dichloro-1-phenoxycarbonyl-2-trifluoromethylbenzimidazole, 2-benzimidazole methyl cabbamate, 4-methylsulfonyltetrachloropyridine, 10,10′-oxybisphenoxyarsine, 2- (4-thiazolyl) benzimidazole (TBZ) and the like can be mentioned. Among them, N is N from the viewpoint of antifungal effect and discoloration by ultraviolet rays.
Preferred are -substituted benzimidazole compounds, specifically perbendazole, 2-methoxycarbonylaminobenzimidazole and the like. Commercially available products can be used as these organic fungicides.

On the other hand, the inorganic antibacterial agent may be any of tin-based, zinc-based, copper-based, silver-based, and arsenic-based ones, and tricarganotin, cuprous oxide, the above-mentioned metal or metal ion is zeolite. , Silica, and ceramics of calcium compounds such as hydroxyapatite, calcium phosphate, calcium hydrogen phosphate, calcium carbonate, and calcium silicate (for example, JP-A-4-13605) can be used. Among these, silver-based antibacterial agents, particularly those containing silver or silver ions alone or in combination with other metals or metal ions, ammonium ions, etc., on the above-mentioned carrier have physical properties, weather resistance, and safety. It is preferably used from the viewpoint of. Commercially available products can also be used as these inorganic antibacterial agents.

The amount of the above organic antifungal agent to be blended is 100 parts by weight of silicone rubber composition (parts by weight; the same applies hereinafter).
1 to 10 parts, particularly preferably 0.2 to 5 parts,
On the other hand, the compounding amount of the inorganic antibacterial agent is 0.1 to 100 parts, especially 0.2 to 70 parts based on 100 parts of the silicone rubber composition.
It is preferable to set it as a part.

The silicone rubber composition to which the above-mentioned antifungal agent and antibacterial agent are added is not particularly limited, but a room temperature curable silicone rubber composition is effectively used, and the silicone rubber obtained therefrom is effectively antifungal. Can be given.

Such room temperature curable silicone rubber compositions include (a) the following general formula (1)

[0014]

[Chemical 1] (In the formula, R ¹ is the same or different unsubstituted monovalent hydrocarbon group, and n is an integer.) 100 parts of the diorganopolysiloxane (b) at least a hydrolyzable group in one molecule An organosilicon compound having two 0.2 to 30 parts (c) a condensation catalyst 0 to 10 parts is used.

In the component (a), R ¹ in the formula (1) is an alkyl group such as a methyl group, an ethyl group or a propyl group, an aryl group such as a phenyl group or a tolyl group, a vinyl group, From an alkenyl group such as an allyl group, a cycloalkyl group such as a cyclohexyl group, or a chloromethyl group obtained by substituting a part or all of hydrogen atoms of these groups with a halogen atom, a cyano group, a trifluoropropyl group, a cyanoethyl group, etc. The same or different selected substituted or unsubstituted, preferably 1 to 10 carbon atoms
Examples of the monovalent hydrocarbon group include n, and n is a natural number of 1 or more. However, n is preferably 50 to 2000 in terms of viscosity and workability.

Examples of such a diorganopolysiloxane include the following.

[0017]

[Chemical 2]

Next, the organosilicon compound having at least two hydrolyzable groups in one molecule of the component (b) is an essential component for the above composition to cure at room temperature in the presence of moisture. In this case, as the hydrolyzable group, methoxy group, ethoxy group, propoxy group, alkoxy group such as butoxy group, enoxy group such as propenoxy group, acetoneoxy group, ketoxime group such as butanoneoxy group,
Acetoxy group, acyloxy group such as benzoyl group, amino group such as diethylamino group, cyclohexylamino group, amide group such as N-methylacetamide group, dimethylaminoxy group, aminoxy group such as diethylaminoxy group, isocyanate group, α- Examples thereof include a silyl ester group. Although a halogen atom such as a chlorine atom can be used, it is not preferable because the hydrogen halide generated by hydrolysis has severe corrosiveness and toxicity. In addition to the above-mentioned hydrolyzable groups, the group bonded to the silicon atom is a substituted or unsubstituted hydrocarbon group, but an alkyl group having 1 to 8 carbon atoms and a carbon number of 2 for ease of synthesis. -10
Alkenyl groups and phenyl groups are preferred. Specifically, the following compounds may be mentioned.

Alkoxysilanes such as methyltrimethoxysilane, vinyltrimethoxysilane, phenyltrimethoxysilane, methyltriethoxysilane, tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane and 3-chloropropyltrimethoxysilane, and methyltriisoproline. Enoxysilanes such as penoxysilane, vinyltriisopropenoxysilane, phenyltriisopropenoxysilane, methyltris (methylethylketoxime) silane, vinyltris (methylethylketoxime) silane, phenyltris (methylethylketoxime) silane, methyltris (dimethylketoxime) silane , Tetratris (methylethylketoxime) and other ketoxime silanes, methyltriacetoxysilane, vinyltria Alkoxysilanes such as toxysilane, phenyltriacetoxysilane, tetraacetoxysilane, methyltris (N-butylamino) silane, vinyltris (N-hexylamino) silane, aminosilanes such as phenyltris (N, N-diethylamino) silane, methyltris (N -Methylacetamide)
Silanes, amidosilanes such as vinyltris (N-ethylacetamido) silane, aminoxysilanes such as methyltris (N, N-diethylaminoxy) silane, vinyltris (N, N-diethylaminoxy) silane, and partial hydrolysis of these organosilicon compounds. A thing etc. are illustrated.

The amount of component (b) used is preferably 0.2 to 30 parts per 100 parts of component (a). If the amount of this component (b) is too small, the composition will not cure, and if it is too large, the cured physical properties may become hard and brittle.

Further, the component (c) is for accelerating the curing of the composition. For this purpose, compounds conventionally used in this type of composition can be used. A compound is illustrated.

Organic tin compounds such as dibutyltin dimethoxide, dibutyltin diacetate, dibutyltin dioctoate, dibutyltin dilaurate, dimethyltin dimethoxide and dimethyltin diacetate, tetrapropyl titanate, tetrabutyl titanate, tetra-2-ethylhexyl titanate. , Organic titanium compounds such as dimethoxytitanium diacetylacetonate, amine compounds such as hexylamine, 3-aminopropyltrimethoxysilane, tetramethylguanidylpropyltrimethoxysilane and salts thereof.

The amount of component (c) used is 0 to 10 parts per 100 parts of component (a). If the amount of this component (c) is too large, curing failure will occur and sufficient performance as a sealing material will not be obtained. Moreover, in this use, it is not limited to one kind and may be used as a mixture of two kinds or more.

If desired, known components such as a filler may be added to the above composition at a usual dose.

The above-mentioned composition can be prepared by a known method, and the antifungal agent and the antibacterial agent can be mixed with other components.

[0026]

According to the present invention, it is possible to provide a silicone rubber which has a stable antifungal effect for a long period of time and which is not discolored by mold.

[0027]

EXAMPLES The present invention will be specifically described below by showing Examples and Comparative Examples, but the present invention is not limited to the following Examples.

[Example 1] α, ω having a viscosity of 20000 cs
-100 parts of dihydroxydimethylpolysiloxane, 10 parts of fumed silica surface-treated with dimethyldichlorosilane having a specific surface area of 180 m ² / g, 1 part of 2-methoxycarbonylaminobenzimidazole, silver-zinc-loaded hydroxyapatite ceramic antibacterial agent ( Sangi Co., Ltd.
Made of hydroxyapatite ceramics with silver 0.1
%, Zinc 1%) and anatase type titanium oxide 2 parts by a universal mixer to form a base compound. 100 parts by weight of this base compound and 5 parts by weight of methyltriacetoxysilane are mixed under reduced pressure. , Composition 1
It was created.

Example 2 α, ω having a viscosity of 20000 cs
100 parts of dihydroxydimethylpolysiloxane, 10 parts of fumed silica surface-treated with dimethyldichlorosilane having a specific surface area of 180 m ² / g, 1 part of 2-methoxycarbonylaminobenzimidazole, 2-pyridinethiol 1 oxide zinc salt (ZPT ) 1 part and 2 parts of anatase type titanium oxide are mixed with a universal mixer to form a base compound, and 100 parts by weight of this base compound are added with 5 parts by weight of methyltris (methylethylketoxime) silane and 0.1 part of dibutyltin dimethoxide under reduced pressure. And mixed to prepare a composition 2.

Example 3 α, ω having a viscosity of 20000 cs
-100 parts of dihydroxydimethylpolysiloxane, 10 parts of fumed silica surface-treated with dimethyldichlorosilane having a specific surface area of 180 m ² / g, 1 part of 2-methoxycarbonylaminobenzimidazole, silver-ammonium ion-supporting zeolite antibacterial agent (Shinagawa Fuel Co., Ltd., containing ammonium ion 0.5%, silver ion 5%) 1 part and anatase type titanium oxide 2 parts are mixed by a universal mixer to form a base compound, and this base compound 10
5 parts by weight of methyltrimethoxysilane and 0.1 part of dibutyltin dimethoxide were mixed with 0 parts by weight under reduced pressure to obtain a composition 3
It was created.

Comparative Example 1 A composition was prepared in the same manner as in Example 1 except that the silver-zinc-supporting hydroxyapatite ceramic antibacterial agent was removed, and this was designated as Composition 4.

Comparative Example 2 A composition was prepared in the same manner as in Example 2 except that 2-methoxycarbonylaminobenzimidazole and 2-pyridinethiol 1-oxide zinc salt (ZPT) were omitted. It was set to 5.

Next, the mold resistance of the above composition was evaluated.
In this case, the antifungal test method is JIS-Z-2911.
Compliant with. That is, after the composition prepared as described above is molded into a sheet having a thickness of 2 mm and cured at room temperature,
The sample was immersed in warm water of 50 ° C. for 7 days to obtain a sample. On the other hand, potato dextrose agar was filled in a glass petri dish having a diameter of 9 cm, and the above-treated sample was placed in the center. The culture conditions were 28 ° C and 56 days. As the test bacterial species, Aspergillus terreus (AT), Penicillium funiculosum (PF), Cladosporium cladsporioides (CC), and Ketomium globosum (CG) were used. The evaluation standard was in accordance with JIS-Z-2911, and after the test, the surface and cross section of the sample were observed with a microscope (× 100) to examine the presence or absence of hyphae. The results are shown in Table 1.

[0034]

[Table 1]

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Reference number within the agency FI Technical display location C09J 183/04 JGG C09K 3/10 G (72) Inventor Tokuo Sato Ototo, Matsuida-cho, Usui-gun, Gunma Prefecture Mi No. 1 10 Shin-Etsu Chemical Co., Ltd. Silicone Electronic Materials Research Laboratory

Claims (3)

[Claims] 1. An antifungal silicone rubber composition comprising an organic antifungal agent and an inorganic antibacterial agent. 2. The composition according to claim 1, wherein the silicone rubber composition is a room temperature curable silicone rubber composition. 3. A silicone rubber comprising an organic antifungal agent and an inorganic antibacterial agent dispersed therein.