JPH08217977A - Mildew-proofing organopolysiloxane composition reduced in discoloration - Google Patents

Abstract

PURPOSE: To obtain an organopolysiloxane composition which has mildew- proofing properties, heat resistance, and weatherability and is useful as a sealing material, etc., by compounding a specific organopolysiloxane with a specific silane compound and a specific triazole compound. CONSTITUTION: This composition comprises 100 pts.wt. organopolysiloxane (1) represented by formula I (wherein R<1> is a 1-10C unsubstituted monovalent hydrocarbon group optionally partly substituted with one or more halogen atoms; n is an integer of 10 or larger; X is a hydroxy or a hydrolyzable group; and 2<=a<=4), 0.1-30 pts.wt. silane compound having a hydrolyzable group and represented by the formula, R<1> b SiX(4-b) (wherein R<1> and X are the same as in (1) and 0<=b<=1.9) or a partial hydrolyzate thereof (2), and 0.1-5 pts.wt. 1,2,4- triazole compound (3) represented by formula II (wherein R<2> and R<3> each is a monovalent hydrocarbon group; R<4> and R<5> each is H or an alkyl; and Y is a hydroxy or nitrile group).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an organopolysiloxane composition which is used as a sealing material and has excellent antifungal properties and excellent weather resistance such as heat resistance and ultraviolet resistance.

[0002]

2. Description of the Related Art RTV silicone rubber, which is cross-linked by moisture, is easy to handle and has excellent weather resistance and electrical characteristics, so it has been applied in various fields such as sealing materials for building materials and adhesives in the electric and electronic fields. There is. In particular, RTV silicone rubber, which adheres well to various adherends around water and has excellent weather resistance, is widely used. On the other hand, in recent years, the housing construction technology has improved and the airtightness has also improved, and the water around the house has become a suitable habitat for microorganisms such as mold. In particular, fungi often insert hyphae into the inside of RTV silicone rubber, making it difficult to remove it with a chemical as well as wipe it off, often impairing the appearance. This solution can be solved by kneading an antibacterial agent into the sealing material. In particular, benzimidazole compounds, zinc pyrithione and the like are often used in silicone sealing materials from the viewpoint of antibacterial property and safety. However, the sealing material containing these compounds has a problem that it yellows due to heating and exposure to ultraviolet rays, and therefore, there is a drawback in that the added amount cannot be increased until the effect is surely exerted on all molds.

[0003]

Based on such a background, the inventors have developed a fungicide-resistant sealing material which is excellent in antibacterial properties and weather resistance such as heat resistance and ultraviolet resistance and does not discolor. It was found that these objects can be achieved by using a certain antifungal agent.

[0004]

That is, the present invention is a fungicidal organopolysiloxane composition comprising the following (1), (2), and (3) with less discoloration. (1) 100 parts by weight of organopolysiloxane represented by the following general formula (Formula 3),

Embedded image (Here, R ¹ is an unsubstituted monovalent hydrocarbon group having 1 to 10 carbon atoms or a group in which a hydrogen atom of these groups is partially substituted with a halogen atom or the like, and R ¹ is the same as each other. N may be an integer of 10 or more, X represents a hydroxyl group or a hydrolyzable group, and 2 ≦ a ≦ 4.) (2) Hydrolysis represented by the following general formula Silane compound having possible groups and / or partial hydrolyzate thereof
0.1 to 30 parts by weight, R ¹ _b SiX _(4-b) [R ¹ and X represent the same groups as in the above (1), and 0 ≦ b ≦ 1.9. ] (3) 0.1 to 5 parts by weight of a 1,2,4-triazole compound represented by the following general formula (Formula 4),

[Chemical 4] (Here, R ² and R ³ represent a substituted or unsubstituted monovalent hydrocarbon group, R ⁴ and R ⁵ each represent a hydrogen atom or a monovalent alkyl group, and Y represents a hydroxyl group or a nitrile group.) Another invention of the present invention is that the compound of (3) in the composition of (claim 1) is α- [2- (4-chlorophenyl) ethyl] -α- (1,1-dimethylethyl)-.
It contains 0.1 to 5 parts by weight of 1H-1,2,4-triazol-1-yl-ethanol (generic name debuconazole).

In the general formula (Formula 1) of the organopolysiloxane of (1), R ¹ is a substituted or unsubstituted monovalent hydrocarbon group having 1 to 10 carbon atoms, such as methyl group, ethyl group and propyl group. Alkyl groups such as groups; cycloalkyl groups such as cyclohexyl groups; alkenyl groups such as vinyl groups and allyl groups; aryl groups such as phenyl groups and tolyl groups, or the hydrogen atoms of these groups are partially substituted with halogen atoms, etc. It is a group that has been R ¹ may be the same group or different groups, and n in the formula is such that the viscosity of the diorganopolysiloxane at 25 ° C. is in the range of 25 to 500,000 cSt, preferably 1,000 to 100,000. Since it is in the range of cSt, it is an integer of 10 or more. X represents a hydroxyl group or a hydrolyzable group, and examples of the hydrolyzable group include an alkoxy group, a ketoxime group, an acyloxy group, an amino group, an amido group, an aminoxy group and an alkenyloxy group. Further, a represents a number in the range of 2 ≦ a ≦ 4 on average.

In the general formula (2), R ¹ and X represent the same groups as in (1). The value of b has an average value of 0≤b≤1.9, and a plurality of hydrolyzable silanes may be mixed and used. Examples of hydrolyzable silanes are alkoxysilanes such as methyltrimethoxysilane, vinyltriethoxysilane, 3-chloropropyltrimethoxysilane, and 3-aminopropyltriethoxysilane; methyltris (dimethylketoxime) silane, methyltris (methylethylketo). Oxime) silane, vinyltris (methylethylketoxime) silane, tetra (methylethylketoxime) silane and other ketoxime silanes; vinyltriacetoxysilane, methyltriacetoxysilane,
Acyloxysilanes such as phenyltriacetoxysilane; amide silanes such as phenyltris (N-methylacetamido) silane and vinyltris (N-methylacetamido) silane; vinyltris (N-butylamino)
Silanes, aminosilanes such as phenyltris (N, N-diethylamino) silane; aminotrisilanes such as methyltris (N, N-dimethylaminoxy) silane, vinyltris (N, N-diethylaminoxy) silane; vinyltriisopropenoxysilane And alkenyloxysilanes such as methyltriisobutenoxysilane and phenyltricyclohexanoxysilane. The above compound is used in the range of 0.1 to 30 parts by weight with respect to 100 parts by weight of (1), and if it is less than 0.1, sufficient cross-linking cannot be obtained, and a composition having the desired rubber elasticity cannot be obtained. On the other hand, if it exceeds 30, the mechanical properties will be inferior. The preferred range is 1 to 15 parts by weight.

The 1,2,4-triazole compound (3) is an important constituent element in the present invention and is added to the composition of the present invention in order to impart heat resistance, ultraviolet resistance and mildew resistance. is there. In the general formula (Formula 2), R ² and R ³ represent a substituted or unsubstituted monovalent hydrocarbon group, for example, an alkyl group such as a methyl group, an ethyl group, a propyl group; a cycloalkyl group such as a cyclohexyl group; vinyl. Group, an alkenyl group such as an allyl group; an aryl group such as a phenyl group and a tolyl group, or a group in which a hydrogen atom of these groups is partially substituted with a halogen atom or the like. R ² and R ³ may be the same group or different groups. R ⁴ and R
⁵ represents a hydrogen atom or a monovalent alkyl group, which may be the same group or different groups. Y represents a hydroxyl group or a nitrile group. Specific examples of these 1,2,4-triazole compounds include hexaconazole and microbutanyl. The amount added is in the range of 0.1 to 5 parts by weight, particularly 0.3 to 1 part by weight, relative to 100 parts by weight of (1). If it is less than 0.1 part by weight, the above effect is insufficient, and if it is added in excess of 5 parts by weight, the effect does not change and there is a risk that the discoloration resistance is impaired.
Of the 1,2,4-triazole compounds, debuconazole (claim 2) is particularly effective.

In addition to the above-mentioned components, generally known fillers, additives, catalysts and the like may be used in the present invention. Examples of the filler include ground silica, fumed silica, calcium carbonate, zinc carbonate, and wet silica. Examples of the additive include polyether as a thixotropy improving agent, aminosilanes such as γ-aminopropyltriethoxysilane as an adhesion aid, and epoxysilanes such as γ-glycidylpropyltrimethoxysilane. Examples of the catalyst include organic tin compounds and alkoxy titanium. Further, other fungicides may be used in combination as long as the discoloration resistance is not impaired.

[0009]

EXAMPLES The present invention will be described below with reference to examples. (Example 1) 10 parts by weight of fumed silica whose surface was treated with dimethyldichlorosilane, and 0.5 parts by weight of debuconazole were added to 100 parts by weight of polydimethylsiloxane having a silanol-terminated end having a viscosity of 20,000 cSt at 25 ° C. After mixing in a machine, 8 parts by weight of methyltributanoxime silane, 1 part by weight of γ-aminopropyltriethoxysilane,
0.1 part by weight of dibutyltin dioctate was added and thoroughly mixed under reduced pressure to obtain sample 1. (Example 2) 10 parts by weight of fumed silica whose surface was treated with dimethyldichlorosilane and 1.5 parts by weight of debuconazole were added to 100 parts by weight of polydimethylsiloxane having a silanol-terminated end having a viscosity of 20,000 cSt at 25 ° C. After mixing with a mixer, 8 parts by weight of methyltributanoxime silane, 1 part by weight of γ-aminopropyltriethoxysilane,
0.1 part by weight of dibutyltin dioctate was added and thoroughly mixed under reduced pressure to obtain sample 2. (Example 3) 10 parts by weight of fumed silica whose surface was treated with dimethyldichlorosilane and 1 part by weight of debuconazole were added to 100 parts by weight of polydimethylsiloxane having a silanol-terminated end having a viscosity of 20,000 cSt at 25 ° C. After mixing with a mixer, 8 parts by weight of methyltrimethoxysilane, γ
-Aminopropyltriethoxysilane (1 part by weight) and dibutyltin dioctate (0.1 part by weight) were added and thoroughly mixed under reduced pressure to obtain sample 3.

(Comparative Example 1) Viscosity at 25 ° C is 20,000c
100 parts by weight of polydimethylsiloxane whose ends of St were blocked with silanol, 10 parts by weight of fumed silica whose surface was treated with dimethyldichlorosilane, 2- (4-thiazolyl)
-0.5 parts by weight of benzimidazole was added and mixed in a mixer, then 8 parts by weight of methyltrimethoxysilane, 1 part by weight of γ-aminopropyltriethoxysilane, and 0.1 parts by weight of dibutyltin dioctate were added and thoroughly mixed under reduced pressure. Then, a sample 4 was obtained. (Comparative Example 2) 10 parts by weight of fumed silica whose surface was treated with dimethyldichlorosilane and 0.5 part by weight of zinc pyrithione were added to 100 parts by weight of polydimethylsiloxane having a silanol capped end with a viscosity of 20,000 cSt at 25 ° C. After mixing with a mixer, 8 parts by weight of methyltributanoxime silane, 1 part by weight of γ-aminopropyltriethoxysilane, and 0.1 part by weight of dibutyltin dioctate were added and thoroughly mixed under reduced pressure to obtain sample 5.

Comparative Example 3 Debuconazole was added in an amount of 0.08
Sample 6 was obtained in the same manner as in Example 1 except that the weight part was used. (Comparative Example 4) Sample 7 was obtained in the same manner as in Example 1 except that the amount of debuconazole added was changed to 6 parts by weight. Table 1 shows the configurations of the samples in each of the above Examples and Comparative Examples. The numbers in the table represent parts by weight.

Test samples were prepared for each of Samples 1 to 7 in the above Examples and Comparative Examples, and a color change test and a fungicide test were conducted by the following methods, and the results are shown in Table 2. Test method (Discoloration test) The obtained sample was molded into a sheet with a thickness of 2 mm and cured in an atmosphere of 20 ± 2 ° C and 55 ± 10% RH for one week,
The following discoloration test was performed using this sheet. 1 Thermal discoloration test A molded and cured sheet is a color difference meter CR manufactured by Minolta Camera
After measuring the initial color difference at -300, it was left in a circulating dryer at 90 ° C for 500 hours. The color difference of the aged sample was measured to confirm the degree of yellowing (Δb). (The larger the value of Δb is, the more the color changes.) 2 UV discoloration test A molded and cured sheet is manufactured by Minolta Camera Co. Color difference meter CR
After measuring the initial color difference at -300, the distance from the germicidal lamp to the sample was adjusted to 10 cm using a medical germicidal lamp, and ultraviolet rays were irradiated for 24 hours for deterioration. The color difference of the aged sample was measured to confirm the degree of yellowing (Δb). (Antifungal test) The same test sample as that used in the discoloration test was used and measured according to JIS Z 2911. The following method was used for the evaluation of mold resistance. Evaluation method (The rank of mold resistance is defined as follows.) Mold resistance 1: When the area of fungal hyphae of a mold inoculated on a sample or test piece in a certain amount exceeds 1/3 of the total area. Antifungal property 2: When the area of fungal hyphae that has been inoculated in a fixed amount on a sample or test piece does not exceed 1/3 of the total area. Antifungal property 3: When the growth of fungal hyphae of a certain amount of a sample or test piece is not observed.

[0013]

[Table 1]

[0014]

[Table 2]

From the results of (Table 2), the sheet produced from the composition of the present invention as a raw material has the same mildew resistance as the sheet produced from the conventional composition as well as the heat resistance,
It can be seen that the weather resistance such as ultraviolet resistance is far superior to the conventional products.

[0016]

INDUSTRIAL APPLICABILITY According to the present invention, an organopolysiloxane composition having excellent antifungal properties, heat resistance, and UV resistance can be obtained when it is used as a fungicide-resistant sealing material.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical indication location C09K 3/10 C09K 3/10 G (72) Inventor Keio Inoue Matsuida, Usui-gun, Gunma Prefecture Address 1 Shin-Etsu Chemical Co., Ltd. Silicone Electronic Materials Research Laboratory

Claims (2)

[Claims] 1. An antifungal organopolysiloxane composition comprising the following items (1), (2), and (3) with little discoloration. (1) 100 parts by weight of an organopolysiloxane represented by the following general formula (Formula 1), (Here, R ¹ is an unsubstituted monovalent hydrocarbon group having 1 to 10 carbon atoms or a group in which a hydrogen atom of these groups is partially substituted with a halogen atom or the like, and R ¹ is the same as each other. N may be an integer of 10 or more, X represents a hydroxyl group or a hydrolyzable group, and 2 ≦ a ≦ 4.) (2) Hydrolysis represented by the following general formula Silane compound having possible groups and / or partial hydrolyzate thereof
0.1 to 30 parts by weight, R ¹ _b SiX _(4-b) [R ¹ and X represent the same groups as in the above (1), and 0 ≦ b ≦ 1.9. ] (3) 1, 2, shown by the following general formula (Formula 2)
4-triazole compound 0.1 to 5 parts by weight. Embedded image (Here, R ² and R ³ represent a substituted or unsubstituted monovalent hydrocarbon group, R ⁴ and R ⁵ each represent a hydrogen atom or a monovalent alkyl group, and Y represents a hydroxyl group or a nitrile group.) 2. The compound of (3), α- [2- (4-
Chlorophenyl) ethyl] -α- (1,1-dimethylethyl) -1H-1,2,4-triazol-1-yl-
The antifungal organopolysiloxane composition according to claim 1, which contains 0.1 to 5 parts by weight of ethanol (generic name debuconazole).