Room temperature-curable organopolysiloxane composition

The present invention has excellent storage stability and discoloration resistance in an uncured state, and also has excellent rubber elasticity and adhesiveness after curing, and is suitable for a sealant, an adhesive, a coating agent or a potting agent. It relates to an alcohol-type room temperature curable organopolysiloxane composition.

Condensation-curable silicone-based sealants, adhesives, coating agents, and potting agent compositions are used in numerous fields such as construction, electrical and electronic, transport aircraft, electrical components, and home appliances. Condensation-curable silicone-based sealants, adhesives, coating agents, and potting agent compositions used in these applications usually have at least three hydrolyzable groups bonded to silicon atoms in one molecule as a cross-linking agent. Organosilicon compounds and / or partial hydrolysates thereof are used. This essentially refers to trifunctional hydrolyzable silanes and / or partial hydrolysates thereof, specifically alkyltrimethoxysilanes, alkyltributanoximsilanes, alkyltriacetoxysilanes, alkyltriisopropenos. Xysilane or a partial hydrolyzate of these. Among these, there is increasing interest in a one-component de-alcohol type room temperature curable organopolysiloxane composition using a de-alcohol type cross-linking agent from the viewpoint of corrosiveness and safety.

For applications that require transparency, discoloration tends to be a problem with titanium-based catalysts, so tin-based catalysts are generally used. However, this tin compound causes decomposition of the siloxane chain by alcohol and is in an uncured state. When stored in a sealed container for a long period of time, the curability may be significantly inferior. Conventionally, it is known to use an alcohol scavenger typified by a silazane compound having a Si-N bond in order to improve this storage stability, but the use of this scavenger tends to reduce the adhesiveness. Was strong. Further, in general, for sealing material applications, it is desired to have excellent rubber elasticity as well as excellent adhesiveness.

The following are examples of prior documents related to the present invention.<patcit num="1"><text>Special Fair 4-13382 Gazette</text></patcit><patcit num="2"><text>Japanese Unexamined Patent Publication No. 1-113429</text></patcit><patcit num="3"><text>Japanese Unexamined Patent Publication No. 11-189720</text></patcit><patcit num="4"><text>Japanese Unexamined Patent Publication No. 2000-7918</text></patcit><patcit num="5"><text>Special Table 2004-535248 Gazette</text></patcit><patcit num="6"><text>Special Fair 7-81079 Gazette</text></patcit>

<p> The present invention has been made in view of the above circumstances, and is a sealant, adhesive, coating agent or a sealant, an adhesive, a coating agent, which has excellent storage stability and discoloration resistance in an uncured state, and has excellent rubber elasticity and adhesiveness after curing. An object of the present invention is to provide a dealcoholized room temperature curable organopolysiloxane composition suitable for a potting agent.</p>

<p> As a result of diligent studies to achieve the above object, the present inventor (A) has a viscosity of 500 mPa · s or more at 25 ° C, and at least two Si-OH groups or at least two Si-OH groups in one molecule. 100 parts by mass of organopolysiloxane having at least two organooxy groups, (B) 0.5 to 20 parts by mass of organosilane having at least two organooxy groups in one molecule or a partial hydrolyzate thereof, (C) organotin catalyst 0.01 to 10 parts by mass, (D) 1 to 30 parts by mass of Si-OH group-containing organopolysiloxane represented by the following average composition formula (1), with a viscosity of 300 mPa · s or less at 25 ° C.<chemistry num="1"><img file="JP2007106944A_D0001.tif" /></chemistry>(In the formula, R and R¹Are identical or heterologous unsubstituted or substituted monovalent hydrocarbon groups, where a, b, c are 0.01 &lt;a &lt;0.2, 0b &lt;0.4, 1.7 &lt;c &lt;1.9, 1.6 &lt;(a + b + c). ) &lt;2.5. ), The room temperature curable organopolysiloxane composition can be a cured product having excellent storage stability and discoloration resistance in an uncured state, and excellent rubber elasticity and adhesiveness after curing. It has been found to be effective as an adhesive, coating agent, potting agent, etc. That is, by blending the special organopolysiloxane shown by the component (D) in the dealcohol-type room temperature curable organopolysiloxane composition, while maintaining excellent storage stability and discoloration resistance in the uncured state. It has been found that a room temperature curable organopolysiloxane composition that gives a cured product having excellent rubber elasticity and adhesiveness after curing can be obtained, and the present invention has been made.</p><p> Therefore, the present invention provides the room temperature curable organopolysiloxane composition shown below.</p><p>[1] (A) 100 parts by mass of an organopolysiloxane having a viscosity at 25 ° C of 500 mPa · s or more and having at least two Si-OH groups or at least two organooxy groups in one molecule, ( B) Organosilane having at least two organooxy groups in one molecule or a partial hydrolyzate thereof 0.5 to 20 parts by mass, (C) Organic tin catalyst 0.01 to 10 parts by mass, (D) Viscosity at 25 ° C 1 to 30 parts by mass of Si-OH group-containing organopolysiloxane represented by the following average composition formula (1), which is 300 mPa · s or less.<chemistry num="2"><img file="JP2007106944A_D0002.tif" /></chemistry>(In the formula, R and R¹Are identical or heterologous unsubstituted or substituted monovalent hydrocarbon groups, where a, b, c are 0.01 &lt;a &lt;0.2, 0b &lt;0.4, 1.7 &lt;c &lt;1.9, 1.6 &lt;(a + b + c). ) &lt;2.5. ), A room temperature curable organopolysiloxane composition.</p><p>[2] The component (A) is one or more selected from the diorganopolysiloxane represented by the following general formula (2) and the polysiloxane represented by the following general formula (3) [1]. Room temperature curable organopolysiloxane composition.<chemistry num="3"><img file="JP2007106944A_D0003.tif" /></chemistry>(In the formula, R is the same or dissimilar unsubstituted or substituted monovalent hydrocarbon group, and k is an integer of 100 or more.)<chemistry num="4"><img file="JP2007106944A_D0004.tif" /></chemistry>(In the formula, R, k, X are as described above. It is an oxygen atom or an alkylene group having 2 to 5 carbon atoms, and m is an integer of 0 or 1.) [3] Further, (E) a filler is added. (A) The room temperature curable organopolysiloxane composition according to [1] or [2], which contains 1 to 500 parts by mass with respect to 100 parts by mass of the component.</p><p>[4] Furthermore, as a component (F), organosilazane represented by the following general formula (4)<chemistry num="5"><img file="JP2007106944A_D0005.tif" /></chemistry>(In the formula, R is as described above) is contained in 0.1 to 2 parts by mass with respect to 100 parts by mass of the component (A). Polysiloxane composition.</p><p>[5] The room temperature curable organopolysiloxane composition according to any one of [1] to [4] for a sealant, an adhesive, a coating agent or a potting agent.</p>

<p> The room temperature curable organopolysiloxane composition of the present invention can be a cured product having excellent storage stability and discoloration resistance in an uncured state, and also having excellent rubber elasticity and adhesiveness after curing, and can be a sealant and an adhesive. It is useful as an agent, coating agent, potting agent, etc.</p>

[(A) component]

The component (A) in the present invention is an organopolysiloxane having a viscosity at 25 ° C. of 500 mPa · s or more and having at least two Si-OH groups or at least two organooxy groups in one molecule. .. In this case, as the component (A), a diorganopolysiloxane represented by the following general formula (2) or (3) is preferable. In order to obtain particularly excellent long-term storage stability and adhesiveness, the diorganopolysiloxane represented by the formula (3) is more preferable.

<chemistry num="6"><img file="JP2007106944A_D0006.tif" /></chemistry>(In the formula, R is the same or dissimilar unsubstituted or substituted monovalent hydrocarbon group, and k is an integer of 100 or more.)

<chemistry num="7"><img file="JP2007106944A_D0007.tif" /></chemistry>(In the formula, R, k, X are as described above. It is an oxygen atom or an alkylene group having 2 to 5 carbon atoms, and m is an integer of 0 or 1.)

In the above formula (2) or (3), R is an independently unsubstituted or substituted monovalent hydrocarbon group, each of which has 1 to 20 carbon atoms, particularly an alkyl group having 1 to 6 carbon atoms and 2 to 20 carbon atoms. In particular, an alkenyl group having 2 to 6 carbon atoms, an aryl group having 6 to 20 carbon atoms, particularly an aryl group having 6 to 12 carbon atoms, or a group in which a part of their hydrogen atoms is substituted with a halogen atom is exemplified, and specifically. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, a cyclohexyl group and the like. Examples of the alkenyl group include a vinyl group, an allyl group and the like, examples of the aryl group include a phenyl group and the like, and examples of the halogen substituent include a 3,3,3-trifluoropropyl group and the like. Further, k is an integer of 100 or more, and the viscosity of this diorganopolysiloxane at 25 ° C is in the range of 500 to 100,000 mPa · s, preferably in the range of 1,000 to 50,000 mPa · s. Here, the viscosity is a value measured by a rotational viscometer.

The compound represented by the formula (3) is obtained by heating the compound represented by the formula (2) and a silane having an alkoxy group in the presence of amines such as isopropylamine, butylamine and dibutylamine, or an corresponding alkenylsiloxane. It can be easily obtained by subjecting a silane having a hydrosilyl group and an alkoxy group, or a silane having an alkenyl group and an alkoxy group to the corresponding hydrosiloxane by an addition reaction in the presence of a catalyst.

[(B) component]

Organosilane having at least two organooxy groups in one molecule of the component (B) or a partial hydrolyzate thereof is mainly used as a curing agent when the compound of the formula (2) is used as the component (A). When the compound of the formula (3) is used as the component (A), it mainly acts as a storage stabilizer. In this case, examples of the organosilane having an organooxy group of the component (B) include those represented by the following formula (5).

<chemistry num="8"><img file="JP2007106944A_D0008.tif" /></chemistry>

Where R²Is the same or dissimilar unsubstituted or substituted monovalent hydrocarbon group, and examples thereof include those having 1 to 20 carbon atoms, particularly 1 to 6 carbon atoms, and the same group as R described above. R³Is a monovalent organic group having 1 to 10 carbon atoms, preferably 1 to 6 carbon atoms, and OR³Examples thereof include an alkoxy group such as a methoxy group, an ethoxy group, a propoxy group, an n-butoxy group, an isobutoxy group and a tert-butoxy group, an asyloxy group such as an acetoxy group, an acryloxy group, a metharoxy group and a phenoxy group. Further, n is preferably 2,3 or 4, particularly 2 or 3. Examples of such an organosilane include methyltrimethoxysilane.

The blending amount of the component (B) is 0.5 to 20 parts by mass, preferably 2 to 10 parts by mass with respect to 100 parts by mass of the component (A). If it is less than 0.5 parts by mass, sufficient rubber physical characteristics cannot be obtained, the composition becomes thickened during storage, or gels. If it exceeds 20 parts by mass, the rubber elasticity of the obtained cured product decreases.

[(C) component]

The organic tin catalyst of the component (C) acts as a reaction catalyst of the component (A) and the component (B) in the composition of the present invention and as a reaction catalyst of the component (A) represented by the formula (3). is there. Examples thereof include tin ester compounds such as dioctate tin, alkyl tin ester compounds such as dibutyltin diacetate, dibutyltin dilaurate and dibutyltin dioctate, and one or more of these tins are used. By using the compound, a transparent cured product having good discoloration resistance can be provided.

Among these tin compounds, secondary or tertiary organic acid-derived dialkyls such as dioctyl tin dineodecanoate and dibutyl tin di (2-ethylhexoate) are used to obtain excellent long-term storage stability. The use of tin ester compounds is particularly preferred.

The blending amount of these organic tin catalysts is 0.01 to 10 parts by mass, preferably 0.05 to 5 parts by mass with respect to 100 parts by mass of the component (A). If it is less than 0.01 parts by mass, sufficient curing characteristics cannot be obtained, and if it exceeds 10 parts by mass, the durability of the composition is lowered.

In the present invention, in addition to the above organic tin catalyst, tetraisopropoxytitanium, tetran-butoxytitanium, tetrakis (2-ethylhexoxy) titanium, dipropoxybis (acetylacetona) titanium, and titaniumisopropoxyoctylene glycol. Titanic acid ester or titanium chelate compound, zinc naphthenate, zinc stearate, zinc-2-ethyloctate, iron-2-ethylhexoate, cobalt-2-ethylhexoate, manganese-2-ethylhe Organic metal compounds such as xoate, cobalt naphthenate, alkoxyaluminum compound, aminoalkyl group-substituted alkoxysilanes such as 3-aminopropyltriethoxysilane, N-β (aminoethyl) γ-aminopropyltrimethoxysilane, hexylamine, Amine compounds such as dodecylamine phosphate, tetramethylguanidine, diazabicyclononane and salts thereof, quaternary ammonium salts such as benzyltriethylammonium acetate, lower fatty acid salts of alkali metals such as potassium acetate, sodium acetate and lithium oxalate, Dialkyl hydroxylamines such as dimethyl hydroxylamine and diethyl hydroxylamine, guanidyl groups such as tetramethylguanidylpropyltrimethoxysilane, tetramethylguanidylpropylmethyldimethoxysilane, and tetramethylguanidylpropyltris (trimethylsiloxy) silane. Examples thereof include silane or siloxane contained. In particular, amine compounds such as tetramethylguanidine and diazabicyclononane, tetramethylguanidylpropyltrimethoxysilane, tetramethylguanidylpropylmethyldimethoxysilane, tetramethylguanidylpropyltris (trimethylsiloxy) silane and the like. Silane or siloxane containing a guanidyl group may be used in combination.

[(D) component]

In the present invention, as the component (D), a Si-OH group-containing organopolysiloxane having a viscosity at 25 ° C. of 300 mPa · s or less and represented by the following average composition formula (1) is blended.

<chemistry num="9"><img file="JP2007106944A_D0009.tif" /></chemistry>(In the formula, R and R¹Are identical or heterologous unsubstituted or substituted monovalent hydrocarbon groups, where a, b, c are 0.01 &lt;a &lt;0.2, 0b &lt;0.4, 1.7 &lt;c &lt;1.9, 1.6 &lt;(a + b + c). ) &lt;2.5. )

The component (D), contact of the compositions of the present invention improves the adhesion, it is necessary for cured rubber sheet elongation improve.

Here, R is as described above. Also, R¹Is especially the R mentioned above³The same as is suitable, OR¹As above OR³The same as is exemplified.

If a is 0.01 or less, it is insufficient to improve the adhesiveness and the elongation of the cured rubber sheet, and if a is 0.2 or more, the storage stability of the obtained composition may be lowered. If b is 0.4 or more, the elongation of the cured rubber sheet may be reduced, which is not preferable.

The viscosity of the component (D) at 25 ° C is 300 mPa · s or less, more preferably 5 to 250 mPa · s.

The blending amount of the component (D) is 1 to 30 parts by mass, preferably 2 to 15 parts by mass with respect to 100 parts by mass of the component (A). If it is less than 1 part by mass, sufficient adhesion and elongation improving effect cannot be obtained, and if it exceeds 30 parts by mass, the storage stability of the composition is lowered.

The component (D) can be obtained mainly by hydrolyzing dichlorodiorganosilane and trichloroorganosilane, or by hydrolyzing an alkoxyl derivative of these compounds.

[(E) component]

In the present invention, a filler can be blended as the component (E). The filler of the component (E) acts as a reinforcing agent and a bulking agent in the composition of the present invention. Specific examples of the filler include surface-treated or untreated fumigant silica, wet silica, precipitated silica, metal oxide, metal hydroxide, glass beads, glass balloons, resin beads, and resin balloons. In particular, fuming silica, precipitated silica, and calcium carbonate are preferably used. These can be used alone or in combination of two or more. Among the above-mentioned compounds, it is particularly preferable to use fumigant silica for the composition that gives a transparent cured product.

The blending amount of these fillers is preferably 1 to 500 parts by mass, particularly 5 to 250 parts by mass with respect to 100 parts by mass of the component (A). If it is less than 1 part by mass, the effect as a reinforcing agent or a bulking agent may not be obtained, and if it exceeds 500 parts by mass, the discharge property of the composition may be lowered and the workability may be deteriorated.

[(F) component]

In the present invention, organosilazane can be further blended as the component (F). The component (F), organosilazane, is an alcohol scavenger for improving storage stability, and specifically, a disilazan compound represented by the following formula (4) is blended.

<chemistry num="10"><img file="JP2007106944A_D0010.tif" /></chemistry>

Here, R is as described above, and more specifically, hexamethyldisilazane, divinyltetramethyldisilazane, and the like are preferable as the disilazane compound.

The blending amount is preferably 0.2 to 10 parts by mass, particularly 0.5 to 4 parts by mass with respect to 100 parts by mass of the component (A). If it is less than 0.2 parts by mass, the effect as a storage stabilizer may not be obtained, and if it exceeds 10 parts by mass, the adhesiveness of the composition may be lowered.

[Other ingredients]

When adhesiveness is required, the composition of the present invention preferably contains a silane coupling agent as an adhesiveness-imparting component. As the silane coupling agent, known ones are preferably used. In particular, as the hydrolyzable group, those having an alkoxysilyl group and an alkenoxysilyl group are preferable, and vinyltris (β-methoxyethoxy) silane, γ-methacryloxypropyltrimethoxysilane, β- (3,4-epoxycyclohexyl). ) Ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, N-β- (aminoethyl) γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane , Γ-Mercaptopropyltrimethoxysilane, γ-glycidoxypropyltriisopropenoxysilane, γ-glycidoxypropylmethyldiisopropenoxysilane and the like. In particular, it is preferable to use an amine-based silane coupling agent.

The blending amount of this silane coupling agent is preferably 0.1 to 20 parts by mass, particularly 0.2 to 10 parts by mass with respect to 100 parts by mass of the component (A). If it is less than 0.1 parts by mass, sufficient adhesiveness may not be obtained, and if it exceeds 10 parts by mass, it may be disadvantageous in terms of price.

Further, in the composition of the present invention, a generally known additive other than the above-mentioned components may be used as long as the object of the present invention is not impaired. Additives include polyether as a thixophilic improver, silicone oil as a plasticizer, isoparaffin, trimethylsiloxy units as a crosslink density improver, and SiO.₂Examples include reticulated polysiloxane consisting of units, and if necessary, pigments, dyes, colorants such as fluorescent whitening agents, antifungal agents, antibacterial agents, cockroach repellents, physiologically active additives such as marine organism repellents, etc. Add phenylsilicone oil as bleed oil, fluorosilicone oil, surface modifiers such as organic liquids incompatible with silicone, solvents such as toluene, xylene, solvent volatile oil, cyclohexane, methylcyclohexane, and low boiling isoparaffin. Can be done.

The organopolysiloxane composition of the present invention can be obtained by uniformly mixing each of the above-mentioned components and other components according to a conventional method. In this case, it may be a one-component system or a two-component system, but a one-component system is preferable.

The organopolysiloxane composition of the present invention thus obtained provides a cured product having excellent rubber elasticity and adhesiveness after curing while maintaining excellent storage stability and discoloration resistance in an uncured state. It is a room temperature curable organopolysiloxane composition and can be suitably used as a sealant, an adhesive, a coating agent, a potting agent and the like.

The curing conditions of the organopolysiloxane composition may be the same as those of a normal room temperature curable condensation-curable silicone rubber composition, and generally, the temperature is 5 to 40 ° C and the humidity is 10 to 90. It is used well in the environment of% RH.

Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples, but the present invention is not limited to the following Examples. In the following example, Me represents a methyl group. The viscosity shows the value at 25 ° C measured by a rotational viscometer. The characterization of the composition was carried out by the method shown below. Cartridges filled with each of the compositions 1 to 8 described below were cured after being left at room temperature for 2 days, and the evaluated one was defined as "initial", and the cartridge was stored in a 70 ° C dryer for 14 days and then left at room temperature for 1 day. After that, it was cured and evaluated as "70 ° C 14 days". A 2 mm thick sheet was prepared from the initial composition and stored at 70 ° C for 14 days and cured in an atmosphere of 23 ° C, 55% RH for 7 days. The physical characteristics of the obtained cured product were evaluated by a method according to JIS K 6301, and are shown in Table 1.

[Example 1]

As a component (A), 50 parts by mass of dimethylpolysiloxane having a viscosity of 50,000 mPa · s with both ends sealed with a trimethoxysilyl group, 3 parts by mass of methyltrimethoxysilane as a component (B), and dioctyltin as a component (C). Composition formula (HO) with 0.05 parts by mass of geneodecanoate, (D) component with a viscosity of 60 mPa · s and a Si-OH content of 0.06 mol / 100 g._0.05Me_1.75SiO_1.14 parts by mass of organopolysiloxane shown by, 13 parts by mass of silica R972 (trade name, manufactured by Nippon Aerodil Co., Ltd.) as component (E), 0.5 parts by mass of hexamethyldisilazane as component (F), and trimethylsilyl at both ends. Add 35 parts by mass of dimethylpolysiloxane and 0.5 parts by mass of N-β- (aminoethyl) γ-aminopropyltrimethoxysilane having a viscosity of 100 mPa · s sealed with a group and mix until uniform to prepare composition 1. did. This composition was filled in a cartridge having a capacity of 330 ml. The evaluation results of this composition are shown in Table 1.

[Example 2]

In Example 1, the composition 2 was prepared in the same manner as in Example 1 except that 3 parts by mass of methyltrimethoxysilane as the component (B) was changed to 1 part by mass of methyltrimethoxysilane and 2 parts by mass of dimethyldimethoxysilane. Was prepared. The evaluation results of this composition are shown in Table 1.

[Example 3]

In Example 1, the composition formula (HO) in which the viscosity as the component (D) is 60 mPa · s and the Si-OH content is 0.06 mol / 100 g._0.05Me_1.75SiO_1.1Composition formula (HO) with a viscosity of 16 mPa · s and a Si-OH content of 0.04 mol / 100 g instead of the organopolysiloxane shown in_0.03(MeO)_0.22Me_1.84SiO_0.96Composition 3 was prepared in the same manner as in Example 1 except that the amount was 4 parts by mass. The evaluation results of this composition are shown in Table 1.

[Comparative example 1]

In Example 1, the composition formula (HO) in which the viscosity as the component (D) is 60 mPa · s and the Si-OH content is 0.06 mol / 100 g._0.05Me_1.75SiO_1.1Composition 4 was prepared in the same manner as in Example 1 except that the organopolysiloxane shown in (1) was not added. The evaluation results of this composition are shown in Table 1.

[Comparative example 2]

In Example 1, the composition formula (HO) in which the viscosity as the component (D) is 60 mPa · s and the Si-OH content is 0.06 mol / 100 g._0.05Me_1.75SiO_1.1Instead of adding the organopolysiloxane represented by, the composition formula HO- (SiMe) has a Si-OH content of 0.22 mol / 100 g.₂O)₁₂Composition 5 was prepared in the same manner as in Example 1 except that 4 parts by mass of silanol-terminated polydiorganosiloxane represented by -H was added. The evaluation results of this composition are shown in Table 1.

[Comparative example 3]

In Comparative Example 2, the composition formula HO- (SiMe) having a Si-OH content of 0.22 mol / 100 g₂O)₁₂Composition 6 was prepared in the same manner as in Example 1 except that 1.1 parts by mass of the compound was used instead of adding 4 parts by mass of the silanol-terminated polydiorganosiloxane represented by -H. This is the same as the component (D) of Example 1 in terms of the Si-OH content in the compound addition amount. The evaluation results of this composition are shown in Table 1.

<tables num="1"><img file="JP2007106944A_D0011.tif" /></tables>

From Table 1, it was confirmed that Examples 1 to 3 were superior to Comparative Examples 1 to 3 in both the initial elongation (%) and the cohesive fracture rate (%) at both the initial stage and after storage at 70 ° C for 14 days. Was done. This indicates that it has high rubber elasticity and high adhesiveness not only at the initial stage but also after long-term storage.

[Example 4]

As a component (A), 50 parts by mass of dimethylpolysiloxane having a viscosity of 50,000 mPa · s with both ends sealed with hydroxyl groups, and as a component (B), 3 parts by mass of methyltrimethoxysilane, dibutylamine / acetic acid / methyltrimethoxysilane = Mix 1.25 parts by mass of a 2 / 0.5 / 10 mass ratio mixture, leave at 70 ° C for 2 hours, return to room temperature, and (C) a 50% toluene solution of dibutyltin di (2-ethylhexoate) as a component. Composition formula (HO) with 0.2 parts by mass, viscosity of 60 mPa · s as component (D), and Si-OH content of 0.06 mol / 100 g._0.05Me_1.75SiO_1.14 parts by mass of organopolysiloxane shown by, 13 parts by mass of silica R972 (trade name, manufactured by Nippon Aerodil Co., Ltd.) as component (E), 1 part by mass of hexamethyldisilazane as component (F), and trimethylsilyl at both ends. Add 35 parts by mass of dimethylpolysiloxane and 0.5 parts by mass of N-β- (aminoethyl) γ-aminopropyltrimethoxysilane having a viscosity of 100 mPa · s sealed with a group and mix until uniform to prepare composition 7. did. This composition was filled in a cartridge having a capacity of 330 ml. The evaluation results of this composition are shown in Table 2.

[Comparative example 4]

In Example 4, the composition formula (HO) in which the viscosity as the component (D) is 60 mPa · s and the Si-OH content is 0.06 mol / 100 g._0.05Me_1.75SiO_1.1Composition 8 was prepared in the same manner as in Example 4 except that the organopolysiloxane shown in (1) was not added. The evaluation results of this composition are shown in Table 2.

<tables num="2"><img file="JP2007106944A_D0012.tif" /></tables>

From Table 2, it was confirmed that Example 4 was superior to Comparative Example 4 in both the initial elongation (%) and the cohesive fracture rate (%) after storage at 70 ° C for 14 days. This indicates that it has high rubber elasticity and high adhesiveness not only at the initial stage but also after long-term storage.