JP2891625B2 - Room temperature curable organopolysiloxane composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a room-temperature curing method in which a rubber elastic material is cured at room temperature by the action of moisture in the atmosphere, while it is stored in a fluid state under airtight conditions. The present invention relates to a water-soluble organopolysiloxane composition.

[0002]

2. Description of the Related Art Conventionally, room temperature-curable organopolysiloxane compositions as described above have been widely used as sealing materials, coating materials, adhesives, etc. in the fields of the building industry, the machinery industry, the electric industry and the like. . However, the cured rubber elastic body formed from this composition is liable to contaminate its surface and its surroundings. For example, when it is used for the above-mentioned applications, it has a drawback such as impairing the aesthetics of the building, and has an improvement. Is desired.

[0003]

Various additives have been studied to improve this drawback. For example, a surfactant having a polyoxyethylene group, a sorbitan residue or a disaccharide residue (Japanese Patent Application Laid-Open No. JP-A-76452, JP-A-56-76453), a method of incorporating a surfactant having at least one fluorine atom in a molecule (see JP-A-58-167647) into a composition, A method in which a surfactant having at least one fluorine atom in the molecule and an organosilicon compound having an amino group are combined and blended (Japanese Patent Laid-Open No. 61-340 / 1986)
No. 62) have been proposed, but these have not been able to prevent contamination of the surface of the cured product or its vicinity for a long period of time.

Accordingly, an object of the present invention is to provide a room-temperature-curable organopolysiloxane composition which can form a cured product without contaminating the surface and its vicinity for a long period of time.

[0005]

SUMMARY OF THE INVENTION The present invention provides a fluorine-containing organosilicon compound having a (meth) acrylic group and a (meth) acrylic group and a hydrolyzable group in a conventional room temperature-curable organopolysiloxane, and By adding a photopolymerization initiator, the above problem has been successfully solved.

That is, according to the present invention, (A) a diorganopolysiloxane in which both ends of a molecular chain are blocked with a hydroxyl group,
(B) an organosilicon compound having at least three hydrolyzable groups bonded to silicon atoms in one molecule or a partial hydrolyzate thereof, (C) the following general formula (1) or (2):

[0007]

Embedded image

[0008]

Embedded image

Wherein Me is a methyl group, Rf ¹ is a perfluoroalkyl group or a perfluorooxyalkyl group,
Rf ² is a perfluoroalkylene group or a perfluorooxyalkylene group, R ¹ and R ⁴ may be the same or different and are divalent organic groups, and R ² and R ³ are the same or different An unsubstituted or substituted monovalent hydrocarbon group, R ⁵ is a hydrogen atom or a methyl group, X is a hydrolyzable group, a, c, and e are integers of 0 to 2, b, d, and f, respectively. Is
A + b, c + d, e + f
Is 3 or less, and a room temperature-curable organopolysiloxane composition comprising a fluorine-containing organosilicon compound represented by the following formula (D) and a photopolymerization initiator:

The composition of the present invention is cured by moisture in the air to form a cured product of a rubber elastic body, and the component (C) contained in the cured product contains a fluorine-containing organosilicon compound. , (Meth) acrylic group, so that it has photocurability. Therefore, when the composition of the present invention is used outdoors as a sealing material or the like, the component (C) distributed on the surface of the cured product is cured by sunlight, and the cured product of the previously formed rubber elastic body is cured. Contaminants, such as coated and uncured components, are prevented from seeping out of the interior, thereby making it possible, for example, to prevent contamination of the sealant surface or its surroundings.

Component (A) The diorganopolysiloxane of the component (A) is one in which both terminals of the molecular chain are blocked with hydroxyl groups, which is conventionally used as a base component of a room temperature-curable organopolysiloxane composition. It is used from. That is, the hydroxyl group at the molecular end of the polysiloxane is condensed with a hydrolyzable group contained in the component (B) described later, and a cured rubber-like elastic body is formed.

The diorganopolysiloxane has, for example, the following general formula (3):

Embedded image In the formula, R ⁶ and R ⁷ may be the same or different,
Is an unsubstituted or substituted monovalent hydrocarbon group, and n is a positive integer.

In the above general formula (3), R ⁶ and R ⁷
Examples of the monovalent hydrocarbon group include a methyl group, an ethyl group,
Alkyl group such as propyl group; cycloalkyl group such as cyclohexyl group; alkenyl group such as vinyl group and allyl group;
Aryl groups such as a phenyl group and a tolyl group; aralkyl groups such as a benzyl group and a phenylethyl group; and groups obtained by substituting at least a part of the hydrogen atoms of these groups with a halogen atom, for example, a chloromethyl group, Examples thereof include a 3-trifluoropropyl group.

Further, the diorganopolysiloxane is
The viscosity at 25 ° C. is preferably in the range of 1,000 to 10,000 cSt, and therefore, n in the general formula (3) is 10
It is preferably an integer of the above.

Component (B) The organosilicon compound (B) is a compound having at least three hydrolyzable groups bonded to a silicon atom in one molecule or a partially hydrolyzed product thereof. As described above, it is a component that acts as a crosslinking agent. That is, in the presence of moisture (for example, moisture contained in air), the hydrolyzable group condenses with the hydroxyl group in the component (A) to form a cured product. Examples of the hydrolyzable group include an alkoxy group, a ketoxime group, an acyloxy group,
An amide group, an aminoxy group, an alkenyloxy group and the like can be mentioned.

In the present invention, the organosilicon compound may be either a silane or a siloxane compound.
Specifically, the following compounds can be used alone or in combination of two or more. Alkoxysilanes such as methyltrimethoxysilane, vinyltriethoxysilane, and 3-chloropropyltrimethoxysilane;
Ketoxime silanes such as methyltris (dimethylketoxime) silane, methyltris (methylethylketoxime) silane, vinyltris (methylethylketoxime) silane and tetra (methylethylketoxime) silane. Acyloxysilanes such as vinyltriacetoxysilane, methyltriacetoxysilane, and phenyltriacetoxysilane; Phenyltris (N-methylacetamido) silane, vinyltris (N-methylacetamido)
Amidosilanes such as silane. Aminooxysilanes such as methyltris (N, N-dimethylaminoxy) silane and vinyltris (N, N-diethylaminoxy) silane. Alkenyloxysilanes such as vinyltriisopropenoxysilane, methyltriisobutenoxysilane, and phenyltricyclohexanoxysilane. One or two of the above silanes
More than one kind of partial hydrolyzate.

The component (B) is usually added in an amount of 0.5 to 30 parts by weight per 100 parts by weight of the component (A). If the amount is less than 0.5 part by weight, gelation may occur during the production or storage of the composition, or the resulting cured product of the elastic body may not exhibit the desired physical properties. If the amount is more than the amount of the component, the shrinkage of the composition at the time of curing increases, and the elasticity of the obtained cured product may decrease.

Component (C) The fluorine-containing organosilicon compound of the component (C) is represented by the general formula (1) or (2), and is a compound having a property of being cured by light irradiation.

In the general formulas (1) and (2), R ¹ and R
⁴ is a divalent organic group, specifically, a methylene group,
Alkylene groups such as ethylene group and propylene group, cycloalkylene groups such as cyclopentylene group and cyclohexylene group, arylene groups such as phenylene group, -ROR-, -R
An ether bond-containing group such as SR-, -RCO ₂ R-, -R
Ester bond-containing groups such as SO ₃ R-, ketone bond-containing groups such as -RCOR-, -RCON (R ') R-, -RS
An amide bond-containing group such as O ₂ N (R ′) R— can be exemplified. In the above, R is a divalent hydrocarbon group, for example, an alkylene group such as a methylene group, an ethylene group or a propylene group, a cycloalkylene group such as a cyclopentylene group or a cyclohexylene group, or an arylene group such as a phenylene group. R ′ is a monovalent hydrocarbon group, for example, an alkyl group such as a methyl group, an ethyl group or a propyl group, a cycloalkyl group such as a cyclopentyl group or a cyclohexyl group, an alkenyl group such as a vinyl group or an allyl group, a phenyl group, a tolyl group. And a group in which at least a part of the hydrogen atoms of these groups is substituted with a halogen atom or the like.

R ² and R ³ are an unsubstituted or substituted monovalent hydrocarbon group, for example, an alkyl group such as a methyl group, an ethyl group or a propyl group; a cycloalkyl group such as a cyclohexyl group; a vinyl group or an allyl group Alkenyl groups such as isopropenoxy group; aryl groups such as phenyl group and tolyl group; aralkyl groups such as benzyl group and phenylethyl group;
And a group in which some of the hydrogen atoms of these groups are substituted with halogen atoms or the like, for example, 3,3,3-trifluoropropyl group, 6,6,6,5,5,4,4,3, Examples thereof include a 3-nonafluorohexyl group, a chloromethyl group, and a 3-chloropropyl group.

R ⁵ is a hydrogen atom or a methyl group, and X is a hydrolyzable group. The hydrolyzable group is the same group as that exemplified for the hydrolyzable group in the component (B), and specific examples include those represented by the following formula.

[0022]

Embedded image

In the above formula, R ⁸ and R ⁹ are a hydrogen atom or a monovalent hydrocarbon group. Examples of the monovalent hydrocarbon group include an alkyl group such as a methyl group, an ethyl group, and a propyl group,
Examples thereof include a cycloalkyl group such as a cyclopentyl group and a cyclohexyl group, and an aryl group such as a phenyl group and a tolyl group.

Further, in the general formula (1), Rf ¹ is a monovalent fluorine-containing group, and is a perfluoroalkyl group or a perfluorooxyalkyl group. Examples of the perfluoroalkyl group include those represented by the following formula (1a): C _n F _{2n + 1} − (1a) wherein n is a positive integer, preferably an integer of 1 to 16. Can be exemplified.

The perfluorooxyalkyl group includes the following formulas (1b) to (1d):

Embedded image Wherein Y is F or CF ₃ and p, q, r and s
Are positive integers, respectively. Here, p is 1 to 30, and q is 1 to 1.
5, r is preferably an integer in the range of 1 to 20, and s is preferably an integer in the range of 1 to 20.

In the general formula (2), Rf ² is a divalent fluorine-containing group, and is a perfluoroalkylene group or a perfluorooxyalkylene group.

As the perfluoroalkylene group, for example, the following formula (2a): —C _m F _2m — (2a) In the formula, m is a positive integer, preferably an integer of 1 to 16. Can be exemplified.

As the perfluorooxyalkylene group,
Formulas (2b) to (2d) below:

Embedded image In the formula, Y is F or CF ₃ , and p, q, r, s, and t are positive integers, respectively. Here, p is 1 to 30, and q is 1 to
15, r is an integer of 1 to 8, s is an integer of 1 to 20, and t is an integer of 1 to 20.

In the general formulas (1) and (2), a
A to c are integers of 0 to 2 respectively, and b, d, and f are integers of 1 to 3, provided that a + b, c + d, and e + f are each 3 or less. . Therefore, the fluorine-containing organosilicon compound of the component (C) does not necessarily have the hydrolyzable group X,
When the compound has a hydrolyzable group X, the compound also has condensation curability, so that the component (C) is incorporated into and retained in the cured product, thereby preventing contamination by stable photocuring. Is stably expressed.

In the component (C), the fluorine-containing organosilicon compound represented by the general formula (1) or (2) may be used alone or in combination of two or more. Is also good. This component (C)
Is usually added in an amount of 0.5 to 5 parts by weight per 100 parts by weight of the component (A). If the amount is less than 0.1 part by weight, a sufficient coating layer cannot be formed on the surface of the condensed cured product even when exposed to light, so that contamination cannot be effectively prevented. Also, if it is mixed in more than 15 parts by weight,
Not only does the physical properties of the obtained cured product of the elastic body deteriorate, but it is economically disadvantageous.

The fluorine-containing organosilicon compound represented by the general formula (1) is represented by the following formula (4):

Embedded image In the formula, Rf ¹ , R ¹ , R ² , X and a are, as shown in the general formula (1), a hydrolyzable silane compound represented by the following general formula (5):

Embedded image By reacting with a silane compound represented by the following formula in the presence of a condensation catalyst.

The fluorine-containing organosilicon compound represented by the general formula (2) is represented by the following formula (6):

Embedded image In the formula, R ¹ , R ² , Rf ² , X and c, e represent a hydrolyzable silane compound represented by the general formula (2), for example, represented by the general formula (5). By reacting with the silane compound to be produced in the presence of a condensation catalyst.

When the fluorine-containing organosilicon compound represented by the general formula (1) or (2) is produced in accordance with the above-mentioned method, the general formula (5) ) May be used in excess of the hydrolyzable silane compound represented by the general formula (4) or (6).

The above condensation reaction is carried out at room temperature to 80 ° C.
Degree, normal pressure or under reduced pressure (for example, 20mmHg ~ 200mmHg)
It is preferable to perform the above. The condensation reaction is carried out using a condensation catalyst, and any known catalyst may be used, for example, lead-2-ethyl octoate, dibutyltin diacetate, dibutyltin dilaurate,
Butyltin tri-2-ethylhexoate, iron-2-ethylhexoate, cobalt-2-ethylhexoate, manganese-2-ethylhexoate, zinc-2-ethylhexoate, caprylic acid Metal salts of organic carboxylic acids such as tin, tin naphthenate, tin oleate, tin butylate, titanium naphthenate, zinc naphthenate, cobalt naphthenate, zinc stearate; tetrabutyl titanate, tetra-2-ethylhexyl titanate, tri Organic titanates such as ethanolamine titanate and tetra (isopropenyloxy) titanate; organic titanium compounds such as organosiloxytitanium and β-carbonyltitanium; lower fatty acids of alkali metals such as potassium acetate, sodium acetate and lithium oxalate; dimethyl Hydroxyamine, A dialkylhydroxylamine such as ethylhydroxylamine; tetramethylguanidine, and a guanidyl compound such as a guanidyl group-containing silane or siloxane represented by the following formulas (7) and (8) are used alone or in combination of two or more. be able to. The addition amount of these condensation catalysts is determined by the general formula (4)
Alternatively, it is used in an amount of about 0.001 to 5.0 parts by weight per 100 parts by weight of the hydrolyzable silane compound (6).

[0035]

Embedded image

(D) Component The photopolymerization initiator of the component (D) is for promoting the photopolymerization of the acrylic group, and for promoting the photopolymerization of the fluorine-containing organosilicon compound of the component (C). It is to be blended. As the photopolymerization initiator, a known compound conventionally used can be used. For example, acetophenone, propiophenone, benzophenone, xanthol, fluorein, benzaldehyde,
Anthraquinone, triphenylamine, 4-methylacetophenone, 3-pentylacetophenone, 4-methoxyacetophenone, 3-bromoacetophenone, 4-allylacetophenone, p-diacetylbenzene, 3-methoxybenzophenone, 4-methylbenzophenone,
-Chlorobenzophenone, 4,4-dimethoxybenzophenone, 4-chloro-4-benzylbenzophenone,
-Chloroxantone, 3,9-dichloroxantone, 3-chloro-8-nonylxantone, benzoin, benzoin methyl ether, benzoin butyl ether, bis (4-dimethylaminophenyl) ketone, benzylmethoxyketal, 2-chlorothio Xanthone, diethylacetophenone, 1-hydroxycyclohexyl phenyl ketone, 2-methyl [4- (methylthio) phenyl] 2-morpholino-1-propanone,
Examples thereof include 2,2-dimethoxy-2-phenylacetophenone and diethoxyacetophenone.

The amount of component (D) is desirably in the range of 0.01 to 10 parts by weight, particularly 0.1 to 5 parts by weight, per 100 parts by weight of the organopolysiloxane of component (A). When the amount is less than 0.01 part by weight, the component (C)
If the photopolymerization does not proceed effectively, and if the amount is more than 10 parts by weight, there is a tendency that the strength of the cured product of the obtained elastic material becomes low.

Other Ingredients In the present invention, in addition to the essential components (A) to (D) described above, the components themselves may be used as long as the purpose of preventing contamination of the surface of the cured product or its surroundings is not impaired. Known additives can be appropriately compounded. For example, in order to accelerate the condensation curing reaction between the hydroxyl group in the component (A) and the hydrolyzable group in the component (B), an organometallic compound;
A condensation catalyst such as a titanium chelate compound and a guanidyl group-containing compound (specifically, the same one as the condensation catalyst for producing the component (C)) can be used. Further, in order to adjust the physical properties of the rubber-like elastic body of interest, fumed silica, precipitated silica, titanium dioxide, aluminum oxide,
Quartz powder, reinforcing agents such as talc and bentonite, and fibrous fillers such as asbestos, glass fibers and organic fibers can be used. In addition, an oil resistance improving agent such as potassium methacrylate; a coloring agent; a heat resistance improving agent such as red iron oxide and cerium oxide; a cold resistance improving agent; a thixotropic agent such as polyether; a dehydrating agent; , Depending on the purpose.

Room Temperature Curable Organopolysiloxane Composition The composition of the present invention can be obtained as a one-part room temperature curable composition by uniformly mixing the above-mentioned components in a dry atmosphere. When this composition is exposed to the air, the crosslinking reaction proceeds due to the moisture in the air, and the composition cures to a rubber elastic body. When the cured product is exposed to light, for example, when left outdoors, the component (C) The protective coating is formed by the curing of ()), and contamination due to seepage of unreacted components from the inside of the cured product is effectively prevented. Therefore, since the cured product is non-staining, the composition of the present invention is very effectively used particularly for applications such as sealing materials and coating materials for building exteriors.

[0040]

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

Examples 1 to 3 and Comparative Example 1 100 parts of dimethylpolysiloxane (viscosity: 20,200 cSt), both ends of which are blocked by a hydroxyl group, fumed silica whose surface was treated with hexamethyldisilazane (specific surface area: 150m ² / g) 12 parts, 1.5 parts of titanium dioxide, were mixed, after passed once through a three-roll, further, anhydrous methyl tributyl Tano oxime silane 7 parts, 0.1 parts of dibutyltin dioctoate, and By defoaming and mixing in the state described above, a base composition (Comparative Example 1) was obtained.

This base composition has the following formula:

Embedded image Each of the fluorine-containing organosilicon compounds represented by 1.
0 parts (Example 1), 3.0 parts (Example 2), and 5.0 parts (Example 3) were blended, and further, 2.0 parts of diethoxyacetophenone was added, and a room temperature curable composition was added. Was prepared.

Next, two square granites (dimensions 300
× 300 × 15 mm) are arranged so as to face each other with a gap of 15 mm, and after filling each of the curable compositions of Examples 1 to 3 prepared above (filling dimension 300 × 300 × 15m
m), the composition was cured to prepare a test body. Also,
As Comparative Example 1, a test piece was prepared in the same manner using only the base composition not containing the above-mentioned fluorine-containing organosilicon compound.

The test specimen obtained above was allowed to stand outdoors for 3 months, 6 months, and 12 months, and the surface of the cured product and its surroundings were examined for stain generation. The result was obtained.

Example 4, Comparative Example 2 100 parts of dimethylpolysiloxane (viscosity: 20,500 cSt), both ends of which are blocked by a hydroxyl group, fumed silica whose surface is treated with hexamethyldisilazane (specific surface area: 150 m ²⁾ / g) 12 parts and 1.5 parts of titanium dioxide were mixed and passed through a triple roll once, and then 6 parts of vinyltriisopropenoxysilane and a guanidyl-containing silane represented by the above formula (7). A base composition (Comparative Example 2) was prepared by defoaming and mixing .5 parts in an anhydrous state.

The base composition has the following formula:

Embedded image A fluorine-containing organosilicon compound (3.0 parts) and diethoxyacetophenone (2.0 parts) were added to prepare a room-temperature curable composition (Example 4).

Using this curable composition, a test specimen was prepared in the same manner as in Example 1, and the occurrence of dirt was examined. Further, for the above-mentioned base composition (Comparative Example 2), the occurrence of stains was similarly examined. Table 1 shows the results.

Example 5 As a fluorine-containing organosilicon compound, the following formula:

Embedded image A curable composition at room temperature was prepared in exactly the same manner as in Example 4 except that 3.0 parts of the compound represented by the formula (1) were used, and a test piece was prepared to examine the occurrence of dirt. Table 1 shows the results.

Example 6 As a fluorine-containing organosilicon compound, the following formula:

Embedded image A curable composition at room temperature was prepared in exactly the same manner as in Example 4 except that 3.0 parts of the compound represented by the formula (1) were used, and a test piece was prepared to examine the occurrence of dirt. Table 1 shows the results.

Example 7 100 parts of dimethylpolysiloxane (viscosity: 21,200 cSt), both ends of which are blocked by a hydroxyl group, fumed silica whose surface is treated with hexamethyldisilazane (specific surface area: 120 m ² / g) 12 , 1.5 parts of titanium dioxide, and once passed through a three-roll mill, and then 7 parts of methyltributanoxime silane and 0.1 part of dibutyltin dioctoate were defoamed and mixed in an anhydrous state. By doing so, a base composition was prepared.

The base composition has the following formula:

Embedded image A fluorine-containing organosilicon compound (3.0 parts) and diethoxyacetophenone (2.0 parts) were added to prepare a room-temperature curable composition.

Using this curable composition, a test specimen was prepared in the same manner as in Example 1, and the occurrence of dirt was examined by an outdoor exposure test. Table 1 shows the results.

Example 8 The fluorine-containing organosilicon compound used in Example 7 was different from the compound represented by the following formula:

Embedded image A room temperature-curable composition was prepared in the same manner as in Example 7, except that 3.0 parts of a 1: 1 mixture with the compound represented by the formula (1) was used. The occurrence situation was examined. Table 1 shows the results.

[0054]

[Table 1] ：: No dirt is observed. Δ: Slight dirt is generated. X: Quite dirt is generated.

[0055]

According to the present invention, contamination of the surface of or near the surface of the cured product formed from the condensation-curable room temperature-curable organopolysiloxane composition can be effectively prevented. Accordingly, this composition is extremely useful as a sealant or an adhesive, especially in the construction field.

──────────────────────────────────────────────────の Continued on the front page (72) Inventor Koji Matsuda 1-10 Hitomi, Matsuida-machi, Usui-gun, Gunma Prefecture Inside the Silicone Electronics Materials Research Laboratory, Shin-Etsu Chemical Co., Ltd. (72) Inventor Hirokazu Yamada Usui, Gunma Prefecture Shin-Etsu Chemical Co., Ltd. Silicone Electronic Materials Technology Research Laboratory (72) Inventor: Tsuneo Kimura Tsuneo Kimura Matsuda-cho, Hiroshima 1-chome, Shinjuku Chemical Industry Co., Ltd. Inside the laboratory (72) Inventor Masatoshi Arai 1-10 Hitomi, Matsuida-machi, Usui-gun, Gunma Prefecture Shin-Etsu Chemical Co., Ltd. Silicone Electronics Materials Research Laboratory (58) Fields investigated (Int.Cl. ⁶ , DB name) C08L 83/06 C08L 83/07 C08L 83/08

Claims (1)

(57) [Claims] 1. A diorganopolysiloxane in which both ends of a molecular chain are blocked with hydroxyl groups; and B. an organosilicon compound having at least three hydrolyzable groups bonded to silicon atoms in one molecule, or a part thereof. Hydrolyzate, (C) the following general formula (1) or (2): Embedded image In the formula, Me is a methyl group, Rf ¹ is a perfluoroalkyl group or a perfluorooxyalkyl group, Rf ² is a perfluoroalkylene group or a perfluorooxyalkylene group, and R ¹ and R ⁴ are the same or different. R ² and R ³ may be the same or different; an unsubstituted or substituted monovalent hydrocarbon group; R ⁵ is a hydrogen atom or a methyl group; and X is a divalent organic group. A, c, and e are integers of 0 to 2, b, d, and f are integers of 1 to 3, and a + b, c + d, and e + f are each 3 or less. A room temperature curable organopolysiloxane composition comprising: a fluorine-containing organosilicon compound; and (D) a photopolymerization initiator.