JP2519600B2 - Room temperature curable organopolysiloxane composition having antifungal properties - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a room-temperature-curable organopolysiloxane composition which is easily cured by moisture in the air to form a rubber elastic body, and a cured product thereof, and in particular, has excellent antifungal properties. Room temperature curable organopolysiloxane composition and a cured product thereof.

[0002]

2. Description of the Related Art Conventionally, room-temperature-curable organopolysiloxane compositions, which are easily cured by moisture to form rubber elastic bodies, have been widely used in applications such as adhesives, coating materials, electrical insulation sealing materials, and building sealing materials. Has been done. However, this type of composition has a problem that the mold adheres to the surface and propagates and the appearance is impaired during long-term use.

In order to prevent such mold attachment and reproduction, there is known a method of adding a fungicide to the above composition to suppress the growth of mold. For example, a method of adding 2,3,5,6-tetrachloro-4-methylsulfonylpyridine (JP-A-51-106158), a method of adding 2- (4-thiazolyl) -benzimidazole (JP-A-51158106). 54-127960 JP), N- method of adding a substituted benzimidazolyl carbamate derivative (JP 56-38348 JP), the following _{formula, R-Ph-SO 2 -C} (R 1) 2 -I ( wherein , R is hydrogen, halogen or an alkyl group having 1 to 4 carbon atoms, and R ¹ is hydrogen, iodine or an alkyl group having 1 to 4 carbon atoms). 56-127658), a method of adding a triorganotin compound (JP-A-56-133150, JP-A-57-9604).
4), a method of adding benzimidazolyl-alkyl-carbamate (JP-A-60-18693), a method of adding tetraalkylthiuram disulfide (JP-A-60-115660), etc. .

[0004]

However, with the method of adding an antifungal agent as described above, it is not possible to prevent the growth of all types of fungi, and it is difficult to maintain its effect for a long period of time. Met. Therefore, an object of the present invention is to provide a room temperature curable organopolysiloxane composition in which the growth of all kinds of mold is effectively suppressed for a long period of time, and a cured product thereof.

[0005]

According to the present invention, (a)
Following general formula _{^{(1): HO- [Si (}} R 1) 2 O] in n -H formula, ^{R 1} is a substituted or unsubstituted monovalent hydrocarbon group having same or different, n is a positive An integer, a diorganopolysiloxane represented by: (b) an organosilicon compound having at least two hydrolyzable groups in one molecule, (c) the following general formula: Ca (OH) _x (CO ₃ ). _y [where (x / 2) + y = 1] calcium carbonate hydroxide, the carbonation rate
Provided is a room temperature-curable organopolysiloxane composition having antifungal properties, which comprises calcium carbonate hydroxide having [y × 100 (%)] of 10 to 90% , and (d) a condensation catalyst. To be done.

That is, the present invention is characterized by using calcium carbonate hydroxide whose carbonation rate is controlled to 10 to 90%, which effectively suppresses the growth of all types of molds for a long period of time. It is possible.

(A) Diorganopolysiloxane In the present invention, as the base polymer, the above-mentioned general formula (1), that is, HO- [Si (R ¹ ) ₂ O] _n —H (wherein R ¹ and n Is as described above) is used. In the general formula (1), examples of the monovalent hydrocarbon group R ¹ include an alkyl group such as a methyl group, an ethyl group, a propyl group, a butyl group and a hexyl group, an aryl group such as a phenyl group and a tolyl group, and a vinyl group. , Alkenyl groups such as allyl group, butenyl group, hexenyl group, cycloalkyl groups such as cyclohexyl group, aralkyl groups such as benzyl group and 2-phenylethyl group, and a part of hydrogen atoms bonded to carbon atoms of these groups or Examples thereof include groups in which all are substituted with halogen atoms, cyano groups, etc., such as chloromethyl group, trifluoropropyl group, cyanoethyl group and the like. Among these groups,
Those having 1 to 10 carbon atoms are preferable.

In the general formula (1), n corresponds to the degree of polymerization, and is 50 from the viewpoint of viscosity and workability.
It is preferably an integer in the range of to 2000. In the present invention, specific examples of such a diorganopolysiloxane include, but are not limited to, the followings.

HO− (SiMe ₂ O) _p −H, HO− (SiMe ₂ O) _p − (SiPh ₂ O) _q −H, HO− (SiMe ₂ O) _p − [Si (Me) (C ₂ H ₄ CF ₃ ) O] _q −H,
_{HO- (SiMe 2 O) p -} [Si (Me) (CH = CH 2) O] -H ( In the formula, Me represents methyl group, Ph is phenyl group, p
And q are positive integers, respectively, and p + q is an integer corresponding to n. )

(B) Organosiliconization having a hydrolyzable group
Compound In the present invention, the organosilicon compound acts as a crosslinking agent, and the hydrolyzable group in the compound undergoes a condensation reaction with a hydroxyl group of the base polymer at room temperature in the presence of moisture to give a rubber elasticity. A cured product that is the body is formed. Therefore, this organosilicon compound needs to have at least two hydrolyzable groups.

Examples of such a hydrolyzable group include alkoxy groups such as methoxy group, ethoxy group, propoxy group, butoxy group, methoxyethoxy group and ethoxyethoxy group,
Propenoxy group, isobutenyloxy group, 1-ethyl-2-
Enoxy group such as methylvinyloxy group, dimethylketoxime group, methylethylketoxime group, diethylketoxime group, cyclopentanoxime group, ketoxime group such as cyclohexanoxime group, acetoxy group, propionoxy group, butyryloxy group, benzoyl group, etc. Acyloxy group, N-methylamino group, N-ethylamino group, N-propylamino group, N-butylamino group, N, N-dimethylamino group, N, N-diethylamino group, cyclohexylamino group, and other amino groups , N-methylacetamide group, N-ethylacetamide group, N-methylbenzamide group and other amide groups, N,
Examples thereof include aminoxy groups such as N-dimethylaminoxy group and N, N-diethylaminoxy group, isocyanate groups, α-silyl ester groups and the like. In this case, a halogen atom such as a chlorine atom may also act as a hydrolyzable group, but the hydrogen halide generated by hydrolysis has severe corrosiveness and toxicity, which is not suitable for the present invention.

In addition to the above-mentioned hydrolyzable groups, a substituted or unsubstituted hydrocarbon group is bonded to a silicon atom in the organosilicon compound used as the cross-linking agent. From the standpoint of ease of use, an alkyl group having 1 to 8 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, and a phenyl group are preferable.

Specific examples of the organosilicon compound used in the present invention are not limited to these,
It is as follows. Alkoxysilanes such as methyltrimethoxysilane, vinyltrimethoxysilane, phenyltrimethoxysilane, methyltriethoxysilane, tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane and 3-chloropropyltrimethoxysilane, methyltriisopropenoxysilane , Enoxysilanes such as vinyltriisopropenoxysilane, phenyltriisopropenoxysilane, methyltris (methylethylketoxime) silane, vinyltris (methylethylketoxime) silane, phenyltris (methylethylketoxime) silane, methyltris (dimethylketoxime)
Silane, tetrakis (ketoxime silane such as methylethylketoxime silane, methyltriacetoxysilane, vinyltriacetoxysilane, phenyltriacetoxysilane, acetoxysilane such as tetraacetoxysilane, methyltris (N-butylamino) silane, vinyltris (N-hexyl) Amino) silane, phenyltris (N, N-diethylamino) silane and other aminosilanes, methyltris (N-methylacetamido) silane, vinyltris (N-ethylacetamido) silane and other amidosilanes,
Aminoxysilanes such as methyltris (N, N-diethylaminoxy) silane and vinyltris (N, N-diethylaminoxy) silane, and partial hydrolysates of these organosilicon compounds.

The above-mentioned organosilicon compound is generally used in an amount of 0.2 to 30 parts by weight, particularly 1 to 15 parts by weight, based on 100 parts by weight of the diorganopolysiloxane of the component (a). When the amount of the organosilicon compound used is less than the above range, it becomes difficult to effectively cure the composition, and when it is used in an amount greater than the above range, the resulting cured product becomes hard and brittle and seals. Performance as a material tends to be impaired.

(C) Calcium carbonate hydroxide In the present invention, calcium carbonate hydroxide means the following general
_{Formula: Ca (OH) x (CO} 3) y [wherein, (x / 2) + y = 1 ] is a substance represented by. The carbonation rate (%) is y
× 100, that is, [1- (x / 2)] × 100
It is a defined number. In the present invention, the carbonation rate of the filler is 10 to 90%, preferably 15 to 75%.
Calcium carbonate hydroxide controlled to the range is used. By using calcium carbonate hydroxide having such a carbonation ratio within a certain range, as shown in Examples described later, the growth of all types of mold is suppressed over a long period of time. The cured product thus obtained is obtained.

In the present invention, the reason why excellent antifungal properties are exhibited by using the above calcium carbonate hydroxide is not clear, but it is presumed as follows. That is, the carbonation rate is 1 like ordinary calcium carbonate.
The 00% has a pH of the extracted water in the range of 8 to 9, and as a result, the pH of the cured product of the obtained composition is considerably lower than 10. (Here, the pH of the extracted water of calcium carbonate hydroxide is, for example, 5 g of calcium carbonate hydroxide and 20 cc of methanol are mixed, 60 cc of ion-exchanged water is added, and the mixture is stirred and allowed to stand for 20 minutes. The pH of the cured product is determined by measuring the pH of the subsequent supernatant water, and the pH of the cured product means the pH of water present on the surface of the cured product, and ion-exchanged water is dropped on the surface of the cured product.
It is determined by measuring the pH of a trace amount of water present on the surface using an appropriate device. )

However, in the calcium carbonate hydroxide used in the present invention having a carbonation rate within a certain range, the pH of the extracted water is 10 or more, and the pH of the cured product of the obtained composition is 10 or more. Become. That is, the pH of the cured product
It is considered that under the condition that the ratio is 10 or more, it becomes difficult for all molds to grow, and according to the present invention, a cured product having excellent mold resistance can be obtained.

In the present invention, when the carbonation rate of the calcium carbonate hydroxide used is higher than 90%, the pH of the above-mentioned cured product becomes lower than 10 and it is difficult to suppress the growth of mold. Becomes If the carbonation rate is lower than 10%, the stability of the resulting composition will be impaired. The above-mentioned calcium carbonate hydroxide is generally 1 to 500 parts by weight per 100 parts by weight of the diorganopolysiloxane of the component (a).
It is used in parts by weight, especially 10 to 200 parts by weight.
When the amount of this calcium carbonate hydroxide used is less than the above range, it becomes difficult to effectively suppress the growth of mold, and when it is used in a larger amount than the above range, the obtained cured product becomes hard and brittle, The performance as a sealing material tends to be impaired. Further, this calcium carbonate hydroxide can be used alone or in combination of two or more as long as the carbonation rate is within the above range,
Further, calcium carbonate hydroxide surface-treated with organic soap or the like can also be used.

Such calcium carbonate hydroxide is, for example,
It can be obtained by controlling the amount of carbon dioxide gas to a predetermined value when carbonizing a colloidal solution of calcium hydroxide with carbon dioxide gas.

(D) Condensation Catalyst In the present invention, a condensation catalyst is added to accelerate the curing of the composition. As such a condensation catalyst, conventionally,
What is used for this kind of composition can be used, for example, the following can be illustrated. Dibutyltin dimethoxide, dibutyltin diacetate, dibutyltin dioctoate, dibutyltin dilaurate,
Organotin compounds such as dimethyltin dimethoxide and dimethyltin diacetate, tetrapropyl titanate, tetrabutyl titanate, tetra-2-ethylhexyl titanate, organotitanium compounds such as dimethoxytitanium diacetylacetonate, hexylamine, 3-aminopropyltritate Amine compounds such as methoxysilane and tetramethylguanidylpropyltrimethoxysilane and salts thereof.

These condensation catalysts can be used alone or in combination of two or more, and are generally used in the above (a).
It is used in an amount of 10 parts by weight or less, particularly 0 to 1 part by weight, based on 100 parts by weight of the component diorganopolysiloxane. If the amount of the organosilicon compound used is larger than the above range, the resulting curing failure tends to occur and the performance as a sealing material tends to be impaired.

Other compounding agents In the composition of the present invention, in addition to the above-mentioned components (a) to (d), various compounding agents may be added, if necessary, as long as the mold resistance of the cured product is not impaired. For example, various fillers other than calcium carbonate hydroxide , pigments, dyes, adhesiveness-imparting agents, thixotropy improvers, rust preventives, fungicides, flame retardants and the like can be added.

Room Temperature Curable Composition The room temperature curable composition of the present invention is easily prepared by uniformly mixing the above-mentioned components. When this room temperature curable composition is exposed to the air, the room temperature curable composition is cured by the presence of moisture in the air to form a cured product of a gum elastic body. The pH of the water present on the surface of the cured product is 10 or more as described above, and this effectively suppresses the growth of mold on the surface.

[0024]

EXAMPLES In the following examples, "part" means "part by weight" and "viscosity" is a value measured at 25 ° C.

Example 1 100 parts α, ω-dihydroxydimethylpolysiloxane having a viscosity of 5,000 cSt 100 parts calcium carbonate hydroxide having a carbonation rate of 80% (surface treatment with fatty acid soap, average particle size 0.05 μm) 100 parts 1,3 -Di (ethylaminoxy) -5,7-dipropyl-1,3,5,7-tetramethylcyclotetrasiloxane 2 parts 1,3,5-tri (diethylaminoxy) -7-propyl-1,3,5 , 7-Tetramethylcyclotetrasiloxane (0.3 part) was mixed at room temperature to prepare a room temperature curable composition. This composition was molded into a sheet having a thickness of 2 mm, and the composition was heated at 20 ° C and 55
Curing was performed for 7 days at% RH to obtain a cured product. Ion-exchanged water was added dropwise to this cured product, and the pH of the water on the surface was measured and found to be 10.7. Further, the above cured product was cut into a disk shape having a diameter of 3 cm to obtain a sample piece for a mold resistance test. Diameter 9c according to JIS-Z-2911
A glass petri dish of m was filled with potato dextrose agar, and the sample piece prepared above was placed in the center.
A mold spore suspension of Aspergillus niger, Penicillium citrum, Rhizopus niglycans, Cladosporium herbalum, and Ketomium globosum was uniformly sprayed there, and the petri dish was covered. The petri dish was allowed to stand for 28 days in a thermo-hygrostat having a temperature of 28 ° C. and a relative humidity of 98%, and the test piece was examined. No mold was found.

Comparative Example 1 The same as Example 1 except that calcium carbonate surface-treated with fatty acid soap having an average particle size of 0.05 μm and a carbonation rate of 100% was used in place of the calcium carbonate hydroxide used in Example 1. Similarly, a composition was prepared and a mold resistance test was conducted. As a result, mold reproduction was observed over 1/3 or less of the total area.

Examples 2-3, Comparative Examples 2-3 α, ω-dihydroxydimethylpolysiloxane having a viscosity of 20,000 cSt 100 parts Calcium carbonate hydroxide having a carbonation rate of 65% (surface treatment with resin acid soap, average particle size) Diameter 0.04 μm) 100 parts Methyltris (methylethylketoxime) silane
5.0 parts Dibutyltin dimethoxide 0.5 parts were mixed at room temperature to prepare a room temperature curable composition (Example 2). A room temperature curable composition was prepared in the same manner as in Example 2 except that 4.0 parts of vinyltrimethoxysilane was used instead of methyltris (methylethylketoxime) (Example 3). As a comparative example, a carbonation rate of 9 was used instead of the calcium carbonate hydroxide in Examples 2 and 3 above.
5% Calcium Carbonate Hydroxide (Surface treatment with resin acid soap, average particle size 0.04 .mu.m)
Room temperature curable compositions for comparison were prepared in the same manner as in (Comparative Examples 2 and 3). A cured product was formed from these compositions in the same manner as in Example 1, and a mold resistance test was conducted. As a result, no mold was found in Examples 2 and 3, but in Comparative Examples 2 and 3 1/3 of the total area
Mold reproduction was observed over the following range. For each cured product, ion-exchanged water was dropped as in Example 1,
When the pH of the water adhering to the surface of the cured product was measured, the results were as follows. Example 2: pH 10.5 Example 3: pH 10.5 Comparative Example 2: pH 8.2 Comparative Example 3: pH 8.3

[0028]

According to the present invention, it has become possible to effectively suppress the growth of various molds on the surface of a cured product over a long period of time.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kazutoshi Fujioka 2-13-1, Isobe, Annaka-shi, Gunma Shin-Etsu Chemical Co., Ltd. Silicone Electronic Materials Research Laboratory (72) Nozomi Nawada Motomura, Chigasaki-shi, Kanagawa 2-8-1 Tochi Kikai Co., Ltd. Chigasaki Plant (72) Inventor Koji Moriyama 2-11-1, Nakajima, Kokurakita-ku, Kitakyushu, Fukuoka Prefecture (72) Inventor Hiroshi Hasuike Kanagawa 2-8-1, Motomura, Chigasaki City Tochi Kikai Co., Ltd. Chigasaki Plant (72) Inventor Kazuo Takahashi 2-8-1, Motomura, Chigasaki City Kanagawa Tochi Kikai Co., Ltd. Chigasaki Plant

Claims (2)

(57) [Claims] 1. (a) The following general formula (1): HO- [Si (R ¹ ) ₂ O] _n —H wherein R ¹ is the same or different, substituted or unsubstituted monovalent hydrocarbon group. And n is a positive integer, (b) an organosilicon compound having at least two hydrolyzable groups in one molecule, (c) the following general formula: Ca _{(OH) x (CO 3)} y [wherein, (x / 2) + y = 1 ] in carbonate calcium hydroxide represented by the charcoal carbonation ratio [y × 100 (%)] is 10-90% A room temperature curable organopolysiloxane composition having antifungal properties, which comprises calcium acid hydroxide and (d) a condensation catalyst. 2. A cured product obtained by curing the composition of claim 1.