Curable silicone composition

Abstract

To provide a curable silicone composition excellent in curing rate and hardly causing yellowing after curing.SOLUTION: The present invention relates to a curable silicone composition containing a modified silicone oil having both ends modified with a hydroxyl group or a hydrolyzable group, a crosslinking agent containing a silane having two or more hydrolyzable groups in one molecule or a partially hydrolyzed condensate of the silane, an amino group-containing organoalkoxysilane, and an acid anhydride group-containing organoalkoxysilane.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a curable silicone composition. [Background technology]

[0002] Curable silicone compositions that cure under the action of moisture in the air have been known for some time and are widely used as adhesives and sealing materials (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-17684 Summary of the Invention [Problem to be solved by the invention]

[0004] However, further improvements in the performance of the above-mentioned known curable silicone compositions are expected, such as a high cure rate and resistance to yellowing after curing.

[0005] The present invention was made to meet these expectations, and its object is to provide a curable silicone composition that has an excellent cure rate and is resistant to yellowing after curing. [Means for solving the problem]

[0006] (1) A curable silicone composition according to an embodiment of the present invention for achieving the above object comprises: a modified silicone oil whose both ends are modified with hydroxyl groups or hydrolyzable groups; a crosslinking agent containing a silane having two or more hydrolyzable groups in one molecule or a partial hydrolysis condensate of the silane; an amino group-containing organoalkoxysilane; an acid anhydride group-containing organoalkoxysilane; Includes. (2) The curable silicone composition according to another embodiment may preferably further contain a curing catalyst. (3) In a curable silicone composition according to another embodiment, the amino group-containing organoalkoxysilane may preferably be 3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-(2-aminoethylamino)propyltriethoxysilane, or 3-(2-aminoethylamino)propyltrimethoxysilane. (4) In a curable silicone composition according to another embodiment, the acid anhydride group-containing organoalkoxysilane may preferably be [3-(triethoxysilyl)propyl]succinic anhydride, [3-(trimethoxysilyl)propyl]succinic anhydride, [3-(triethoxysilyl)propyl]maleic anhydride, [3-(trimethoxysilyl)propyl]maleic anhydride, [3-(triethoxysilyl)propyl]phthalic anhydride, or [3-(trimethoxysilyl)propyl]phthalic anhydride. (5) In the curable silicone composition according to another embodiment, the amount of the amino group-containing organoalkoxysilane may preferably be greater than the amount of the acid anhydride group-containing organoalkoxysilane. [Effects of the Invention]

[0007] The present invention provides a curable silicone composition that has an excellent cure rate and is resistant to yellowing after curing. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 shows the state of the Petri dishes containing each curable silicone composition before they are placed in the thermo-humidistat chamber. [Figure 2] FIG. 2 shows the state of each Petri dish shown in FIG. 1 after 20 minutes have passed since it was placed in the thermo-humidistat chamber. [Figure 3] FIG. 3 shows the state of each Petri dish of FIG. 1 after 50 minutes have passed since it was placed in the constant temperature and humidity chamber (that is, 30 minutes have passed since FIG. 2). [Figure 4] FIG. 4 shows the state of each Petri dish of FIG. 1 after 2 hours and 50 minutes have passed since it was placed in the constant temperature and humidity chamber (ie, 2 hours after the state shown in FIG. 3). [Figure 5] FIG. 5 shows the state of each Petri dish of FIG. 1 after 4 hours and 20 minutes have passed since it was placed in the thermo-humidistat chamber (i.e., 1 hour and 30 minutes have passed since FIG. 4). [Figure 6] FIG. 6 shows the state of each Petri dish of FIG. 1 after 19 hours and 20 minutes have passed since it was placed in the constant temperature and humidity chamber (i.e., 15 hours have passed since FIG. 5). [Figure 7] FIG. 7 shows the state of each Petri dish of FIG. 1 after 3 days, 19 hours and 20 minutes have passed since it was placed in the constant temperature and humidity chamber (i.e., 3 days have passed since FIG. 6). [Figure 8] FIG. 8 shows the state of each Petri dish of FIG. 1 after 4 days, 19 hours and 20 minutes have passed since it was placed in the constant temperature and humidity chamber (i.e., one day has passed since FIG. 7). DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the embodiments described below do not limit the inventions according to the claims. Furthermore, not all of the elements and combinations thereof described in the embodiments are necessarily essential to the solution of the present invention.

[0010] The curable silicone composition according to this embodiment comprises a modified silicone oil whose both ends are modified with hydroxyl groups or hydrolyzable groups, a crosslinking agent containing a silane having two or more hydrolyzable groups per molecule or a partial hydrolysis condensate of the silane, an amino group-containing organoalkoxysilane, and an acid anhydride group-containing organoalkoxysilane. The curable silicone composition preferably further comprises a curing catalyst.

[0011] The curable silicone composition may have any plasticity or degree of polymerization. The curable silicone composition preferably has a Williams plasticity at 25°C in the range of 50 to 500. The Williams plasticity is measured using a parallel plate plasticity meter (Williams Plastometer) in accordance with the measurement method specified in JIS K 6249, "Test Methods for Uncured and Cured Silicone Rubber." The curable silicone composition according to this embodiment is a condensation reaction-type curable silicone composition, and can be cured by the simple procedure of reacting with moisture in the air by leaving it at room temperature. In other words, the curable silicone composition is preferably a moisture-curable silicone composition. The "curable silicone composition" may also be referred to as a curable silicone rubber composition or a curable silicone resin composition. The curable silicone composition will be described in detail below.

[0012] The curable silicone rubber composition mainly contains, for example, the following components:

[0013] (1-1) Modified silicone oil Modified silicone oil is the main component of the curable silicone composition. The modified silicone oil has both ends modified with hydroxyl groups or hydrolyzable groups, and is preferably an organopolysiloxane represented by the following chemical formula (1) or chemical formula (2). The chemical formula may also be referred to as an average composition formula.

[0014] [ka]

[0015] [ka]

[0016] In the above chemical formulas (1) and (2), R represents a monovalent hydrocarbon group. Examples of R include one or more hydrocarbon groups selected from alkyl groups (e.g., methyl, ethyl, propyl, butyl, 2-ethylbutyl, octyl), cycloalkyl groups (e.g., cyclohexyl, cyclopentyl), alkenyl groups (e.g., vinyl, propenyl, butenyl, heptenyl, hexenyl, allyl), aryl groups (e.g., phenyl, tolyl, xylyl, naphthyl, diphenyl), aralkyl groups (e.g., benzyl, phenylethyl), and the above hydrocarbon groups in which at least a portion of the hydrogen atoms bonded to the carbon atoms have been substituted with halogens, cyano groups, or the like (e.g., chloromethyl, trifluoropropyl, 2-cyanoethyl, 3-cyanopropyl). The number of carbon atoms in R is preferably 1 to 12, and more preferably 1 to 10. In the above chemical formulas (1) and (2), A represents an oxygen atom or —(CH2) m A is a polymethylene group (including a methylene group) represented by - (m is 1 to 8). A is preferably an oxygen atom or an ethylene group.

[0017] In the above chemical formulas (1) and (2), n is the kinematic viscosity of component (1-1) at 25°C, in the range of 100 to 1,000,000 cm 2 / s. The kinematic viscosity is an arbitrary number within the range of 500 to 500,000 cm 2 It is more preferable that the range is / s.

[0018] In the above chemical formulas (1) and (2), B is a hydrolyzable group. Examples of B include alkoxy groups (e.g., methoxy, ethoxy, propoxy, and butoxy), ketoxime groups (e.g., dimethylketoxime and methylethylketoxime), acyloxy groups (e.g., acetoxy), and alkenyloxy groups (e.g., isopropenyloxy and isobutenyloxy). In the above chemical formulas (1) and (2), x is 2 or 3.

[0019] The component (1-1) can be produced by known methods (for example, an equilibrium reaction using a cyclic siloxane or a linear oligomer with an acid catalyst or a base catalyst).

[0020] When a branched structure is introduced into the component (1-1), it is common practice to add SiO 3 / 2 Units and SiO 4 / 2 A method can be used in which a silane or siloxane containing at least one of the units is added to the modified silicone oil in an amount that does not cause gelation. In order to reduce contamination, it is preferable to remove low-molecular-weight siloxanes by washing or the like before using component (1-1).

[0021] (1-2) Crosslinking agent The crosslinking agent can be a silane having two or more, preferably three or more, hydrolyzable groups per molecule, or a partial hydrolysis condensate of the silane. Examples of the hydrolyzable group include an alkoxy group (e.g., a methoxy group, an ethoxy group, a butoxy group), a ketoxime group (e.g., a dimethylketoxime group, a methylethylketoxime group), an acyloxy group (e.g., an acetoxy group), an alkenyloxy group (e.g., an isopropenyloxy group, an isobutenyloxy group), an amino group (e.g., an N-butylamino group, an N,N-diethylamino group), and an amide group (e.g., an N-methylacetamide group). Among these, the alkoxy group, the ketoxime group, the acyloxy group, and the alkenyloxy group are preferred. Examples of preferred crosslinking agents include tetraethoxysilane and tetramethoxysilane. The amount of crosslinking agent added is preferably within a range of 1 to 70 parts by mass, more preferably within a range of 2 to 60 parts by mass, and even more preferably within a range of 5 to 55 parts by mass, per 100 parts by mass of component (1-1).

[0022] (1-3) Curing catalyst Although a curing catalyst is not essential, the use of a curing catalyst can accelerate the curing of the curable silicone composition. Examples of curing catalysts include alkyltin ester compounds (dibutyltin diacetate, dibutyltin dilaurate, dibutyltin dioctoate, etc.), titanate ester or titanium chelate compounds (tetraisopropoxytitanium, tetra-n-butoxytitanium, tetrakis(2-ethylhexoxy)titanium, diisopropoxybis(ethylacetoacetate)titanium, titanium isopropoxyoctylene glycol, etc.), other suitable organometallic compounds (zinc naphthenate, zinc stearate, zinc-2-ethyloctoate, iron-2-ethylhexoate, cobalt-2-ethylhexoate, manganese-2-ethylhexoate, cobalt naphthenate, alkoxyaluminum compounds, etc.), aminoalkyl group-substituted alkoxysilanes (3-aminopropanol), and the like. Examples of suitable silanes include propyltriethoxysilane, N-β(aminoethyl)γ-aminopropyltrimethoxysilane, etc., amine compounds or salts thereof (hexylamine, dodecylamine phosphate, etc.), quaternary ammonium salts (benzyltriethylammonium acetate, etc.), alkali metal salts of lower fatty acids (potassium acetate, sodium acetate, lithium oxalate, etc.), alkali metal salts of lower fatty acids, dialkylhydroxylamines (dimethylhydroxylamine, diethylhydroxylamine, etc.), and silanes or siloxanes having a guanidyl group (tetramethylguanidylpropyltrimethoxysilane, tetramethylguanidylpropylmethyldimethoxysilane, tetramethylguanidylpropyltris(trimethylsiloxy)silane, etc.). These may be used alone or as a mixture of two or more. The amount of the curing catalyst added is preferably within a range of 0 to 20 parts by mass, more preferably within a range of 0.001 to 10 parts by mass, and even more preferably within a range of 0.01 to 5 parts by mass, per 100 parts by mass of the component (1-1).

[0023] (1-4) Amino group-containing organoalkoxysilane Examples of amino group-containing organoalkoxysilanes include 3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropylmethyldiethoxysilane, 3-(2-aminoethylamino)propyltrimethoxysilane, 3-(2-aminoethylamino)propyltriethoxysilane, N-2(aminoethyl)-3-aminopropylmethyldimethoxysilane, N-methyl-3-aminopropyltrimethoxysilane, and N-phenyl-3-aminopropyltrimethoxysilane. More preferred amino group-containing organoalkoxysilanes are 3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-(2-aminoethylamino)propyltriethoxysilane, and 3-(2-aminoethylamino)propyltrimethoxysilane. Preferred amino group-containing organoalkoxysilanes are 3-aminopropyltriethoxysilane and 3-aminopropyltrimethoxysilane. The amount of amino group-containing organoalkoxysilane blended is preferably within the range of 2 to 65 parts by mass, more preferably within the range of 3 to 55 parts by mass, and even more preferably within the range of 5 to 50 parts by mass, per 100 parts by mass of component (1-1).

[0024] The mass ratio of the amino group-containing organoalkoxysilane to the acid anhydride group-containing organoalkoxysilane is preferably 4 to 0.5:1. The amount of the amino group-containing organoalkoxysilane is more preferably greater than the amount of the acid anhydride group-containing organoalkoxysilane. The mass ratio of the amino group-containing organoalkoxysilane to the acid anhydride group-containing organoalkoxysilane is more preferably 4 to 1.1:1, and even more preferably 2.5 to 1.5:1.

[0025] (1-5) Acid anhydride group-containing organoalkoxysilane Examples of the acid anhydride group of the acid anhydride group-containing organoalkoxysilane include succinic anhydride, maleic anhydride, phthalic anhydride, and acetic anhydride. Examples of the acid anhydride group-containing organoalkoxysilane include [3-(triethoxysilyl)propyl]succinic anhydride, [3-(trimethoxysilyl)propyl]succinic anhydride, [3-(triethoxysilyl)propyl]maleic anhydride, [3-(trimethoxysilyl)propyl]maleic anhydride, [3-(triethoxysilyl)propyl]phthalic anhydride, and [3-(trimethoxysilyl)propyl]phthalic anhydride. Preferred acid anhydride group-containing organoalkoxysilanes are [3-(triethoxysilyl)propyl]succinic anhydride and [3-(trimethoxysilyl)propyl]succinic anhydride. The amount of the acid anhydride group-containing organoalkoxysilane blended is preferably within a range of 2 to 40 parts by mass, more preferably within a range of 3 to 30 parts by mass, and even more preferably within a range of 5 to 25 parts by mass, per 100 parts by mass of component (1-1).

[0026] Amino-group-containing organoalkoxysilanes have the function of improving adhesion, but they also cause yellowing of the cured product when or after the curable silicone composition is cured. This yellowing is closely related to the amino radicals resulting from the presence of the amino-group-containing organoalkoxysilane. The curable silicone composition according to this embodiment contains an acid anhydride group-containing organoalkoxysilane in addition to the amino-group-containing organoalkoxysilane. The acid anhydride group-containing organoalkoxysilane contributes to consuming the amino radicals. As a result, yellowing of the cured product can be suppressed. Furthermore, the acid anhydride group-containing organoalkoxysilane contributes to increasing the curing speed of the curable silicone composition.

[0027] (1-6) Filler Although fillers are not essential, they can be suitably used for purposes such as reinforcement. Examples of fillers include reinforcing agents (fumed silica, precipitated silica, silica whose surface has been hydrophobized with an organosilicon compound, quartz powder, talc, zeolite, bentonite, etc.), fibrous fillers (asbestos, glass fiber, organic fiber, etc.), and basic fillers (calcium carbonate, zinc carbonate, zinc oxide, magnesium oxide, celite, etc.). Among these, silica, calcium carbonate, and zeolite are preferred, and fumed silica and calcium carbonate whose surface has been hydrophobized are even more preferred. The amount of the filler to be added can be selected depending on the purpose and type of filler, but is within the range of 1 to 90% by volume, preferably 5 to 60% by volume, of component (1-1). [Example]

[0028] Next, examples of the present invention will be described in comparison with comparative examples, but the present invention is not limited to the following examples.

[0029] 1. Materials for the curable silicone composition -Hydroxyl-modified silicone oil (Shin-Etsu Chemical Co., Ltd., product number: KF-9701) Tetraethoxysilane (Shin-Etsu Chemical Co., Ltd., product number: T0100) Diisopropoxybis(ethylacetoacetate)titanium (manufactured by Matsumoto Fine Chemical Co., Ltd., product number: TC-750) 3-Aminopropyltriethoxysilane (Shin-Etsu Chemical Co., Ltd., product number: KBE-903) [3-(Trimethoxysilyl)propyl]succinic anhydride (Tokyo Chemical Industry Co., Ltd., product number: T3360)

[0030] 2. Manufacturing method Example 1 A mixture of 10 g of hydroxyl-terminated silicone oil (KF-9701), 5 g of tetraethoxysilane (T0100), 0.2 g of diisopropoxybis(ethylacetoacetate)titanium (TC-750), 1 g of 3-aminopropyltriethoxysilane (KBE-903), and 1 g of [3-(trimethoxysilyl)propyl]succinic anhydride (T3360) was placed in a Petri dish and allowed to stand in a constant temperature and humidity chamber (Kusumoto Chemicals Co., Ltd., model number SXN-412) at a temperature of 23°C and a humidity of 50% RH. The state of cure and color change over time were examined.

[0031] Example 2 The amount of 3-aminopropyltriethoxysilane (KBE-903) was increased to 2 g, and the other materials were mixed in the same manner as in Example 1. A mixture was prepared under the same conditions as in Example 1, and the change in the curing state and color over time was examined.

[0032] Example 3 The amount of 3-aminopropyltriethoxysilane (KBE-903) was increased to 4 g, and the amount of [3-(trimethoxysilyl)propyl]succinic anhydride (T3360) was increased to 2 g, with the other materials being the same as in Example 1. A mixture was prepared under the same conditions as in Example 1, and the change in the curing state and color over time was investigated.

[0033] (Comparative Example) A mixture was prepared under the same conditions as in Example 1, except that [3-(trimethoxysilyl)propyl]succinic anhydride (T3360) was not added, and the change in the curing state and color over time was examined.

[0034] Table 1 shows the blending conditions for Examples 1 to 3 and Comparative Example. The numbers in Table 1 are in grams.

[0035] [Table 1]

[0036] 3. Experimental Results 1 to 8 show the progress of curing over time for the curable silicone compositions produced under the conditions of Examples 1 to 3 and the Comparative Example.

[0037] FIG. 1 shows the state of each Petri dish containing a curable silicone composition before it is placed in a thermo-humidistat chamber. FIG. 2 shows the state of each Petri dish of FIG. 1 after 20 minutes have elapsed since it was placed in the thermo-humidistat chamber. FIG. 3 shows the state of each Petri dish of FIG. 1 after 50 minutes have elapsed since it was placed in the thermo-humidistat chamber (i.e., 30 minutes have elapsed since it was placed in FIG. 2). FIG. 4 shows the state of each Petri dish of FIG. 1 after 2 hours and 50 minutes have elapsed since it was placed in the thermo-humidistat chamber (i.e., 2 hours have elapsed since it was placed in FIG. 3). FIG. 5 shows the state of each Petri dish of FIG. 1 after 4 hours and 20 minutes have elapsed since it was placed in the thermo-humidistat chamber (i.e., 1 hour and 30 minutes have elapsed since it was placed in FIG. 4). FIG. 6 shows the state of each Petri dish of FIG. 1 after 19 hours and 20 minutes have elapsed since it was placed in the thermo-humidistat chamber (i.e., 15 hours have elapsed since it was placed in FIG. 5). Figure 7 shows the state of each Petri dish in Figure 1 after 3 days, 19 hours, and 20 minutes have passed since it was placed in the thermo-humidistat chamber (i.e., 3 days have passed since Figure 6). Figure 8 shows the state of each Petri dish in Figure 1 after 4 days, 19 hours, and 20 minutes have passed since it was placed in the thermo-humidistat chamber (i.e., 1 day has passed since Figure 7).

[0038] (1) About the hardening state Example 1 The content had not yet hardened 20 minutes after the Petri dish was placed in the thermo-humidistat chamber (the start of the curing process) (see Figure 2), but an increase in viscosity was observed 50 minutes after the start of the curing process (see Figure 3). Two hours later, the viscosity increased and a hardened film was formed on the surface (see Figure 4). One hour and 30 minutes later, the hardened film had become thicker (see Figure 5). After 15 hours, approximately 80% of the total volume had hardened (see Figure 6). Three days later and thereafter, the contents of the Petri dish were completely hardened (see Figures 7 and 8).

[0039] Example 2 Twenty minutes after the start of the curing process, an increase in viscosity was observed (see Figure 2). Thirty minutes later, a film (cured film) was observed on the surface (see Figure 3). Two hours later, the cured film on the surface had become thicker (see Figure 4). One hour and 30 minutes later, the cured film had become even thicker (see Figure 5). After 15 hours, approximately 80% of the total volume had hardened (see Figure 6). Three days later and beyond, the contents of the Petri dish had completely hardened (see Figures 7 and 8).

[0040] Example 3 Twenty minutes after the start of the curing process, a film (hardened film) was observed over the entire surface (see Figure 2). Thirty minutes later, an increase in the thickness of the hardened film was observed (see Figure 3). Two hours later, the hardness of the hardened film had increased significantly (see Figure 4). One hour and 30 minutes later, the hardened film had become even thicker (see Figure 5). Then, 15 hours later, approximately 80% of the total volume had hardened (see Figure 6). Three days later and beyond, the contents of the Petri dish were completely hardened (see Figures 7 and 8).

[0041] (Comparative Example) No hardening was observed for 50 minutes after the start of the hardening treatment (see Figures 2 and 3). Two hours and 50 minutes after the start of the hardening treatment, a thin film (hardened film) was observed on the surface (see Figure 4). However, the thickness of the hardened film was the smallest compared to all samples, including Examples 1 to 3. One hour and 30 minutes later, the hardened film had become slightly thicker (see Figure 5). Fifteen hours later, approximately 80% of the total amount had hardened (see Figure 6). Then, three days later and thereafter, the contents of the Petri dish had completely hardened (see Figures 7 and 8).

[0042] (2) Yellowing Example 1 The contents remained transparent for 2 hours and 50 minutes after the start of the curing process (Figures 2 to 4). 1 hour and 30 minutes later, the contents were still transparent (see Figure 5). 15 hours later, some yellowing of the contents was observed (see Figure 6). After that, no significant changes in color were observed (see Figures 7 and 8).

[0043] Example 2 The contents remained transparent from the start of the curing process until complete curing (see Figures 2 to 8).

[0044] Example 3 The contents remained transparent for 2 hours and 50 minutes after the start of the curing treatment (Figures 2 to 4). After 1 hour and 30 minutes, yellowing of the contents was observed, but it was lighter than that of the comparative example (see Figure 5). After that, no significant change in color was observed (see Figures 6 to 8).

[0045] (Comparative Example) The contents remained transparent for 2 hours and 50 minutes after the start of the curing treatment (see Figures 2 to 4). After 1 hour and 30 minutes, yellowing of the contents was observed (see Figure 5). The color was the darkest of all the samples, including Examples 1 to 3. After that, no significant change in color was observed, and the most intense yellowing of all the samples was observed (see Figures 6 to 8).

[0046] (3) Summary Examples 1 to 3, in which an acid anhydride group-containing organoalkoxysilane was added, showed a higher curing rate than the comparative example, in which no acid anhydride group-containing organoalkoxysilane was added. In particular, Examples 2 and 3, in which the amount of acid anhydride group-containing organoalkoxysilane added was increased compared to Example 1, were found to have a higher curing rate than Example 1. Regarding yellowing, Examples 1 to 3 were less yellow than the comparative example, suggesting that the acid anhydride group-containing organoalkoxysilane has a yellowing-inhibiting effect. [Industrial Applicability]

[0047] The present invention can be used, for example, as an adhesive member or a sealing member.

Claims

1. a modified silicone oil whose both ends are modified with hydroxyl groups or hydrolyzable groups; a crosslinking agent containing a silane having two or more hydrolyzable groups in one molecule or a partial hydrolysis condensate of the silane; an amino group-containing organoalkoxysilane; an acid anhydride group-containing organoalkoxysilane; 1. A curable silicone composition comprising:

2. The curable silicone composition of claim 1 further comprising a curing catalyst.

3. 3. The curable silicone composition according to claim 1, wherein the amino group-containing organoalkoxysilane is 3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-(2-aminoethylamino)propyltriethoxysilane, or 3-(2-aminoethylamino)propyltrimethoxysilane.

4. 3. The curable silicone composition according to claim 1, wherein the acid anhydride group-containing organoalkoxysilane is [3-(triethoxysilyl)propyl]succinic anhydride, [3-(trimethoxysilyl)propyl]succinic anhydride, [3-(triethoxysilyl)propyl]maleic anhydride, [3-(trimethoxysilyl)propyl]maleic anhydride, [3-(triethoxysilyl)propyl]phthalic anhydride, or [3-(trimethoxysilyl)propyl]phthalic anhydride.

5. 3. The curable silicone composition according to claim 1, wherein the amount of the amino group-containing organoalkoxysilane blended is greater than the amount of the acid anhydride group-containing organoalkoxysilane blended.

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