Two-pack curable silicone composition containing diyne-containing-amino-modified organopolysiloxane compound, and cured object thereof

Abstract

This two-pack curable silicone composition comprises a first liquid and a second liquid, the first liquid comprising (A) and (C) of the following (A) to (C) components but not including (B) and the second liquid comprising (B) component but not including (C) component. (A) One or more organopolysiloxanes comprising (A-1) component, which is an organopolysiloxane having at least one alkynyl or nitrile group, and / or (A-2) component, which is an organopolysiloxane represented by average empirical formula (1): (R1 3SiO1 / 2)a(R1 2SiO2 / 2)b(R1SiO3 / 2)c(SiO4 / 2)d (R1 is a monovalent hydrocarbon group, a is a number of 2 or greater, and a+b+c+d is a number of 2 or greater) and having a dynamic viscosity of 1-100,000 mm2 / s; (B) an organopolysiloxane compound having a substituent represented by general formula (2) (R2 is a hydrocarbon group or a hydrogen atom, R3 is a hydrocarbon group, and R4 is a linking group); and (C) a metal compound capable of catalyzing a [2+2+2] cycloaddition reaction.　Due to the configuration, provided is a two-pack curable silicone composition which can be stored at ordinary temperature and can be cured through a [2+2+2] cycloaddition reaction under mild conditions.

Description

Two-component curable silicone composition containing diyne-containing amino-modified organopolysiloxane compound and cured product thereof

[0001] The present invention relates to a curable silicone composition containing an amino-modified organopolysiloxane compound that has a diyne in the molecule and is curable, and to a cured product thereof.

[0002] Silicone elastomers are elastic materials based on silicone resin, and because silicone itself has excellent heat and chemical resistance, they are widely used as coating agents, sealants, and encapsulants for semiconductor elements.

[0003] Curable silicone compositions are liquid silicone compositions during use, and can cure to form silicone elastomers when triggered by heat, light, or moisture in the air. Specific curing modes include radical addition reactions, hydrosilylation addition reactions, and condensation reactions. Radical addition reactions generally use peroxides, often requiring high temperatures to generate initiating species, and can suffer from poor surface curing due to oxygen inhibition. Hydrosilylation addition reactions can be cured at room temperature or by heating, depending on the catalyst and reaction inhibitor used. However, the presence or contact of curing inhibitors such as sulfur, phosphorus, nitrogen compounds, water, and organometallic salts can result in poor curing. Condensation reactions can cure at room temperature using moisture in the air, but they generate gas during curing, resulting in volumetric shrinkage and poor deep curing.

[0004] Many curable silicone compositions are used as materials in the periphery of electrical and electronic components and semiconductor elements. However, an increasing number of electrical and electronic components are heat-sensitive and cannot be exposed to high temperatures during mounting. This has created a demand for curable silicone compositions that can be cured under mild conditions of 100°C or less.

[0005] One reaction that can be used as a curing system is the [2+2+2] cycloaddition reaction of alkynes, which uses a transition metal as a catalyst to form carbon-carbon bonds between multiple bonds. The [2+2+2] cycloaddition reaction forms an aromatic ring from three triple bonds. It is a very useful reaction, producing no by-product gases during the reaction. However, no previous reports have shown its application to organopolysiloxane compounds or their cured products. Furthermore, this reaction has a high activation barrier, and when using a catalyst stable at room temperature, high temperatures of 100°C or higher are required to drive the reaction. On the other hand, to drive the reaction under mild conditions below 100°C, a highly active catalyst is required. However, such catalysts require prior preparation and are deactivated under normal humidity conditions, making their use as compositions and long-term storage at room temperature or humidity difficult. (Non-Patent Documents 1-3)

[0006] Reppe, W. et al. Justus Liebigs Ann. , 1948, 560, 104. Vollhardt, K. P. C. Angew. Chem. Int. Ed. Engl. 1984, 23, 539. Saito, S. ; Yamamoto, Y. Chem. Rev. 2000, 100, 2901

[0007] In recent years, there has been an increase in modules containing electrical and electronic components that do not tolerate high temperatures of 100°C or higher, as well as circuit boards equipped with these components. Therefore, low-temperature curing materials that do not require high-temperature curing during assembly are in demand from the perspective of energy conservation. Furthermore, materials that can be stored at room temperature and do not require special temperature control during storage or transportation are in demand from the perspective of reducing environmental impact and the burden on users of material management. However, there are no examples of materials that can be cured at low temperatures using the above-mentioned cycloaddition reaction while taking advantage of the advantage of two-component curing materials, that is, the ability to store at room temperature.

[0008] In view of the above circumstances, an object of the present invention is to provide a curable silicone composition that can be stored at room temperature and that is capable of undergoing a [2+2+2] cycloaddition reaction under particularly mild conditions, as well as a cured silicone product thereof.

[0009] In order to solve the above problems, the present invention provides a two-component curing silicone composition, comprising: (A) an organopolysiloxane comprising the following component (A-1) and / or component (A-2): (A-1) an organopolysiloxane having at least one alkynyl group or nitrile group per molecule; and (A-2) an organopolysiloxane represented by the following average composition formula (1): (R １ ３ SiO １／２ ) ａ (R １ ２ SiO ２／２ ) ｂ (R １ SiO ３／２ ) ｃ (SiO ４／２ ) ｄ (1) (wherein, R １ are each independently an unsubstituted or substituted monovalent hydrocarbon group, a is a number of 2 or more, and a + b + c + d is a number of 2 or more. However, in the case of a linear organopolysiloxane compound, a = 2, b is 2 or more and 1,200 or less, and c = d = 0. In the case of a branched organopolysiloxane compound, a is a number of 2 or more, b is 2 or more and 1,200 or less, and c or d is 1 or more.) and the kinematic viscosity at 25°C represented by ２ (B) an organopolysiloxane compound having a substituent represented by the following general formula (2) in the molecule: (In the formula, R ２ are independently a substituted or unsubstituted monovalent hydrocarbon group or a hydrogen atom, R ３ are independently substituted or unsubstituted divalent hydrocarbon groups, R ４ is a divalent linking group.) and (C) a metal compound capable of catalyzing a [2+2+2] cycloaddition reaction. The present invention provides a two-component curable silicone composition, characterized in that, among the above-mentioned components, the first component contains (A) and (C) but does not contain (B), and the second component contains component (B) but does not contain component (C).

[0010] The curable silicone composition of the present invention can be stored at room temperature, and the [2+2+2] cycloaddition reaction can proceed under mild conditions, allowing the composition to be cured to give a cured silicone product.

[0011] Furthermore, the organopolysiloxane compound of component (A) or (B) is easy to synthesize.

[0012] In this case, in the two-component curing silicone composition of the present invention, R ３ is preferably a methylene group.

[0013] Such component (B) is represented by R in general formula (2). ３ In the case of an organopolysiloxane compound in which is a methylene group, synthesis is easy and it is possible to stably provide a curable silicone composition with suitable performance.

[0014] Furthermore, in the two-component curing silicone composition of the present invention, R ２ is preferably a hydrogen atom.

[0015] Such component (B) is represented by R in general formula (2). ２ When the organopolysiloxane compound is an organopolysiloxane compound in which is a hydrogen atom, synthesis is easy and it is possible to stably provide a curable silicone composition with suitable performance.

[0016] In the composition of the present invention, the component (B) is preferably an organopolysiloxane compound having, on average, two or more substituents represented by the general formula (2) per molecule.

[0017] Such component (B) has, on average, four or more ethynylene groups per molecule that contribute to the [2+2+2] cycloaddition and are linked to each other by nitrogen atoms, allowing the [2+2+2] cycloaddition reaction to proceed more smoothly.

[0018] In the present invention, it is preferable that the composition further contains (D) at least one inorganic or organic filler in an amount of 0.1 to 5,000 parts by mass per 100 parts by mass of the total of components (A) and (B).

[0019] Component (D) of this kind is capable of imparting various properties to the curable silicone composition of the present invention, such as thermal conductivity, heat resistance, reinforcing properties, electrical conductivity, and design properties, and is also capable of providing a homogeneous composition that is not too viscous and therefore easy to handle.

[0020] In this case, the component (D) is preferably a filler made of one or more materials selected from the group consisting of metals, metal oxides, metal hydroxides, metal nitrides, metal carbides, carbon allotropes, resins, dyes, and pigments.

[0021] With such a component (D), it is possible to obtain a composition having the desired properties depending on the material.

[0022] The present invention also provides a cured silicone product obtained by curing the above-described curable silicone composition.

[0023] The silicone cured product of the present invention is an elastic material, and since the silicone itself has excellent heat resistance and chemical resistance, it is useful as a silicone elastomer used as a coating agent, sealing agent, or encapsulant for semiconductor elements.

[0024] According to the present invention, by introducing a specific structure into an organopolysiloxane compound, it is possible to provide organopolysiloxane compounds and silane compounds useful for [2+2+2] cycloaddition reactions. In particular, it is possible to provide a silicone composition that can be cured under mild conditions below 100°C and that can be stored at room temperature. This curing performance allows curing even when using heat-sensitive components that cannot be exposed to high temperatures during assembly, making it highly useful as a material used in the periphery of electrical and electronic components and semiconductor devices. Furthermore, because the material can be stored at room temperature, it is not necessary to maintain the material at temperatures below 0°C during storage or transportation, which is also advantageous from the standpoint of environmental impact and energy consumption. Furthermore, the silicone cured product obtained by curing the composition is an elastic material, and since the silicone itself has excellent heat resistance and chemical resistance, it is useful as a silicone elastomer used as a coating agent, a sealant, an encapsulant for semiconductor devices, and the like. Furthermore, the curable silicone composition of the present invention allows for easy and efficient production of the above composition.

[0025] As described above, there has been a need for the development of a curable silicone composition that can be cured under mild conditions of 100°C or below without the use of a highly active catalyst, that does not become deactivated under normal humidity conditions, and that can be easily used as a composition or stored at normal temperature or humidity for long periods of time.

[0026] As a result of intensive research aimed at solving the above problems, the present inventors discovered that by introducing a substituent having a specific structure into an organopolysiloxane compound, a [2+2+2] cycloaddition reaction can proceed under mild conditions, leading to the present invention.

[0027] That is, the present invention provides a two-component curing silicone composition, comprising: (A) an organopolysiloxane comprising the following component (A-1) and / or component (A-2): (A-1) an organopolysiloxane having at least one alkynyl group or nitrile group per molecule; and (A-2) an organopolysiloxane having the following average composition formula (R １ ３ SiO １／２ ) ａ (R １ ２ SiO ２／２ ) ｂ (R １ SiO ３／２ ) ｃ (SiO ４／２ ) ｄ (1) (wherein, R １ are each independently an unsubstituted or substituted monovalent hydrocarbon group, a is a number of 2 or more, and a + b + c + d is a number of 2 or more. However, in the case of a linear organopolysiloxane compound, a = 2, b is 2 or more and 1,200 or less, and c = d = 0. In the case of a branched organopolysiloxane compound, a is a number of 2 or more, b is 2 or more and 1,200 or less, and c or d is 1 or more.) and the kinematic viscosity at 25°C represented by ２ (B) an organopolysiloxane compound having a substituent represented by the following general formula (2) in the molecule: (In the formula, R ２ are independently a substituted or unsubstituted monovalent hydrocarbon group or a hydrogen atom, R ３are independently substituted or unsubstituted divalent hydrocarbon groups, R ４ is a divalent linking group.) and (C) a metal compound capable of catalyzing a [2+2+2] cycloaddition reaction. Of the above-mentioned components, the first liquid contains (A) and (C) but does not contain (B), and the second liquid contains component (B) but does not contain component (C).

[0028] The present invention will be described in detail below, but the present invention is not limited thereto.

[0029] [Component (A)] As the component (A) in the present invention, the following components (A-1) and (A-2) may be used alone or in combination. When used in combination, the ratio of (A-1) to (A-2) is preferably (A-1):(A-2)=99:1 to 1:99, and more preferably (A-1):(A-2)=90:10 to 10:90.

[0030] [Component (A-1)] The component (A-1) is an organopolysiloxane having at least one alkynyl group or nitrile group in each molecule.

[0031] The alkynyl group is preferably a monovalent hydrocarbon group having 2 to 8 carbon atoms, more preferably 2 to 6 carbon atoms, and a carbon-carbon triple bond. Examples include terminal alkynes such as ethynyl and propargyl groups, and internal alkynes having a group other than a hydrogen atom on the carbon atom forming the carbon-carbon triple bond. Terminal alkynes are preferred, and ethynyl groups are particularly preferred. The nitrile group is preferably a monovalent functional group having 2 to 8 carbon atoms, more preferably 2 to 6 carbon atoms, and a carbon-nitrogen triple bond. Examples include a cyano group, a cyanomethyl group, and a cyanoethyl group, with the cyano group being preferred.

[0032] The alkynyl group or nitrile group may be bonded to either a silicon atom at the terminal of the molecular chain or a silicon atom in the middle of the molecular chain, or may be bonded to both.

[0033] The organic group other than an alkynyl group or a nitrile group bonded to a silicon atom of the organopolysiloxane is an unsubstituted or substituted monovalent hydrocarbon group having 1 to 18 carbon atoms, preferably 1 to 10 carbon atoms, and more preferably 1 to 8 carbon atoms. Examples include alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, pentyl, neopentyl, hexyl, cyclohexyl, octyl, nonyl, and decyl; aryl groups such as phenyl, tolyl, xylyl, and naphthyl; aralkyl groups such as benzyl, phenylethyl, and phenylpropyl; and groups in which some or all of the hydrogen atoms of these groups have been substituted with halogen atoms such as fluorine, bromine, or chlorine, or with cyano groups, such as chloromethyl, chloropropyl, bromoethyl, trifluoropropyl, and cyanoethyl. Methyl and trifluoropropyl groups are particularly preferred.

[0034] The organopolysiloxane has a kinematic viscosity at 25°C of, for example, 1 to 20,000,000 mm ２ / s, preferably 10 to 1,000,000 mm ２ / s, more preferably 60 to 30,000 mm ２ / s. The kinematic viscosity is 1 mm ２ / s or more, the physical properties of the curable silicone composition are good, and ２ If the viscosity is 1 / s or less, the extensibility of the curable silicone composition will be sufficient.

[0035] In the present invention, the kinematic viscosity of component (A-1) is a value measured at 25° C. using an Ostwald viscometer.

[0036] The molecular structure of the organopolysiloxane is not particularly limited as long as it has the above properties, and examples thereof include a linear structure, a branched structure, a partially branched structure, and a linear structure having a cyclic structure. A linear structure in which the main chain is composed of repeating diorganosiloxane units and both molecular chain terminals are capped with triorganosiloxy groups is particularly preferred. The linear organopolysiloxane may also have a partially branched or cyclic structure.

[0037] The organopolysiloxanes may be used alone or in combination of two or more.

[0038] Although the component (A-1) is used in the first liquid, it may also be used in the second liquid.

[0039] [Component (A-2)] The component (A-2) is a compound represented by the following average composition formula (1): (R １ ３ SiO １／２ ) ａ (R １ ２ SiO ２／２ ) ｂ (R １ SiO ３／２ ) ｃ (SiO ４／２ ) ｄ (1) (wherein, R １ are each independently an unsubstituted or substituted monovalent hydrocarbon group, a is a number of 2 or more, and a + b + c + d is a number of 2 or more. However, in the case of a linear organopolysiloxane compound, a = 2, b is 2 or more and 1,200 or less, and c = d = 0. In the case of a branched organopolysiloxane compound, a is a number of 2 or more, b is 2 or more and 1,200 or less, and c or d is 1 or more.) and the kinematic viscosity at 25°C represented by ２ The organopolysiloxane compound is

[0040] The organic group bonded to the silicon atom of the organopolysiloxane is an unsubstituted or substituted monovalent hydrocarbon group having 1 to 18 carbon atoms, preferably 1 to 10 carbon atoms, and more preferably 1 to 8 carbon atoms. Examples include alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, pentyl, neopentyl, hexyl, cyclohexyl, octyl, nonyl, and decyl; aryl groups such as phenyl, tolyl, xylyl, and naphthyl; aralkyl groups such as benzyl, phenylethyl, and phenylpropyl; and groups in which some or all of the hydrogen atoms of these groups have been substituted with halogen atoms such as fluorine, bromine, or chlorine, or with cyano groups, such as chloromethyl, chloropropyl, bromoethyl, trifluoropropyl, and cyanoethyl. Methyl, phenyl, and trifluoropropyl groups are particularly preferred.

[0041] The organopolysiloxane has a kinematic viscosity at 25°C of 1 to 100,000 mm ２ / s, preferably 10 to 50,000 mm ２ / s, more preferably 60 to 30,000 mm ２ / s. The kinematic viscosity is 1 mm ２ / s or more, the physical properties of the silicone composition are good, and ２ If the viscosity is 1 / s or less, a material with a viscosity that is easy to handle as a silicone composition can be obtained.

[0042] In the present invention, the kinematic viscosity of component (A-2) is a value measured at 25° C. using an Ostwald viscometer.

[0043] The molecular structure of the organopolysiloxane is not particularly limited as long as it has the above properties, and examples thereof include a linear structure, a branched structure, a partially branched structure, and a linear structure having a cyclic structure. A linear structure in which the main chain is composed of repeating diorganosiloxane units and both molecular chain terminals are capped with triorganosiloxy groups is particularly preferred. The linear organopolysiloxane may also have a partially branched or cyclic structure.

[0044] The organopolysiloxanes may be used alone or in combination of two or more.

[0045] Although the component (A-2) is used in the first liquid, it may also be used in the second liquid.

[0046] The blending amount of component (A) is preferably 1 to 99 mass percent of the total composition, more preferably 2 to 50 mass percent. When component (D) described below is not included, the blending amount is preferably 10 to 90 mass percent of the total composition, more preferably 20 to 50 mass percent. When component (D) is included, the blending amount is preferably 1 to 80 mass percent, more preferably 2 to 20 mass percent.

[0047] [Component (B)] The organopolysiloxane compound that is component (B) of the present invention is an organopolysiloxane compound having a substituent group represented by the following general formula (2) in the molecule: Component (B) is a compound that contains a diyne having two carbon-carbon triple bonds, and this diyne contributes to [2+2+2] cycloaddition. (In the formula, R ２ are independently a substituted or unsubstituted monovalent hydrocarbon group or a hydrogen atom, R ３ are independently substituted or unsubstituted divalent hydrocarbon groups, R ４ is a divalent linking group.

[0048] In the above formula (2), R ２are independently a substituted or unsubstituted monovalent hydrocarbon group or a hydrogen atom. Specific examples of the monovalent hydrocarbon group include alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, pentyl, hexyl, cyclohexyl, octyl, and dodecyl; aryl groups such as phenyl, 1-naphthyl, 2-naphthyl, and tolyl; aralkyl groups such as benzyl and 2-phenylethyl; and groups in which some or all of the hydrogen atoms of these groups have been substituted with halogen atoms such as fluorine, chlorine, and bromine, such as a chloromethyl group or a 3,3,3-trifluoropropyl group. From the viewpoint of ease of synthesis, etc., a methyl group, an ethyl group, a phenyl group, and a hydrogen atom are preferred, with a hydrogen atom being particularly preferred.

[0049] In the above formula (2), R ３ are independently substituted or unsubstituted divalent hydrocarbon groups. Specific examples of the divalent hydrocarbon group include alkylene groups such as methylene, ethylene, ethylidene, propylene, trimethylene, propylene, propylidene, and isopropylidene. From the viewpoint of ease of synthesis, the methylene and ethylene groups are preferred, and the methylene group is particularly preferred.

[0050] In the above formula (2), R ４ is a divalent linking group. The divalent linking group is not particularly limited, but examples thereof include linear, branched, or ring-containing aliphatic hydrocarbon groups, and aromatic hydrocarbon groups. The aliphatic hydrocarbon group or aromatic hydrocarbon group may have a substituent, and examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, and a carbonyl group. Furthermore, some of the carbon atoms or hydrogen atoms constituting the hydrocarbon group may be substituted with bonds such as an ether bond, an ester bond, a carbonyl bond, a carbonate bond, a carbamate bond, an amino bond, a urethane bond, and a urea bond. As the divalent linking group, linear aliphatic hydrocarbon groups, aromatic hydrocarbon groups, and hydrocarbon groups having an amino bond are preferred, and linear aliphatic hydrocarbon groups are particularly preferred. The linear aliphatic hydrocarbon group preferably has 1 to 20 carbon atoms, more preferably 1 to 10, and particularly preferably 1 to 3.

[0051] Specific examples of the substituent include: In the structural formulas described above, Me represents a methyl group, Et represents an ethyl group, and Ph represents a phenyl group.

[0052] Among the above substituents, the following structures are particularly preferred from the viewpoints of ease of synthesis and reactivity in the [2+2+2] cycloaddition reaction.

[0053] The component (B) preferably contains one or more substituents represented by the formula (2) in one molecule, and particularly preferably contains two or more on average. Such component (B) has at least two, more preferably four or more, ethynylene groups that contribute to the [2+2+2] cycloaddition, and these are linked to each other by nitrogen atoms, making it easy to synthesize and allowing the [2+2+2] cycloaddition reaction to proceed smoothly.

[0054] In the present invention, the component (B) is preferably an organopolysiloxane compound having, on average, two or more substituents represented by the general formula (2) per molecule. Here, "having, on average, two or more per molecule" means that if the compound of component (B) is one type, it has two or more of the above substituents per molecule, and if it is two or more types, the sum of the number of the above substituents per molecule and the molar fraction of each molecule is two or more.

[0055] Furthermore, the molecular structure of the component (B) is not particularly limited as long as it is a compound containing the substituent represented by the general formula (2), and examples thereof include a linear structure, a branched structure, a partially branched structure, or a linear structure having a cyclic structure. In particular, it is preferable that the main chain has a linear structure in which the diorganosiloxane unit is repeated and both molecular chain terminals are blocked with triorganosiloxy groups. The organopolysiloxane having such a linear structure may also have a partially branched or cyclic structure. The substituent represented by the formula (2) may be borne by the triorganosiloxy group at the molecular chain terminal, or by the partially branched or cyclic structure.

[0056] The component (B) preferably has an average molecular weight of 150 to 500,000 g / mol, particularly preferably 250 to 150,000 g / mol. The average molecular weight here means the sum of the products of the molecular weights and molar fractions of each compound, i.e., the number average molecular weight. The average molecular weight can be measured by GPC (gel permeation chromatography) using tetrahydrofuran as an eluent and polystyrene as a standard.

[0057] The kinematic viscosity of the component (B) at 25°C is preferably 1 to 100,000 mm ２ / s, more preferably in the range of 5 to 30,000 mm ２ / s, and more preferably 10 to 5,000 mm ２ / s. This kinematic viscosity is 10 to 5,000 mm ２ When the kinematic viscosity is 1 / s, the cured product obtained from the composition has excellent strength, fluidity, and workability. The kinematic viscosity is a value measured by Ostwald viscosity at 25°C.

[0058] The component (B) preferably has an amine value of 0.1 to 2000 mg KOH / g, where the amine value is the number of mg of potassium hydroxide (KOH: 56.11) equivalent to the acid required to neutralize 1 g of sample.

[0059] The organopolysiloxane compound of the present invention that satisfies the above requirements is, for example, an organopolysiloxane compound represented by the following general formula (3): (R ５ ３ SiO １／２ ) ｅ (R ５ ２ SiO ２／２ ) ｆ (R ５ SiO ３／２ ) ｇ (SiO ４／２ ) ｈ (3) (wherein, R ５ are independently unsubstituted or substituted monovalent hydrocarbon groups, provided that R ５at least one of the groups is a substituent represented by the above formula (2), and e + f + g + h is a number of 0 or greater. However, in the case of a linear organopolysiloxane compound, e = 2, f is preferably 2 or greater and 1,200 or less, and g = h = 0. In the case of a branched organopolysiloxane compound, e is a number of 0 or greater, f is preferably 2 or greater and 1,200 or less, and g or h is 1 or greater. In the case of a cyclic organopolysiloxane compound, e = 0, f is preferably in the range of 3 to 10, more preferably 3 to 6, and g or h is a number of 0 or greater.

[0060] Specific examples of the organopolysiloxane compound and silane compound include: (In the formula, i, j, or k is a number of 0 or more, and i or j is more preferably a number of 2 or more and 1,200 or less. l or m is preferably 0 or more, and l+m is preferably 20 or more and 1,200 or less.) In the structural formula described above, Me represents a methyl group, and Ph represents a phenyl group.

[0061] The metal-catalyzed [2+2+2] cycloaddition reaction is a direct and atom-efficient method for synthesizing fused polycyclic aromatic compounds. Component (A) of the present invention is a [2+2+2] cycloaddition reaction that proceeds in the presence of a metal compound capable of catalyzing the [2+2+2] cycloaddition reaction, and is characterized in that the reaction proceeds under relatively mild conditions, particularly at temperatures below 100°C.

[0062] The component (B) may be used alone or in combination of two or more.

[0063] The blending amount of component (B) is preferably 1 to 99 mass percent of the total composition, more preferably 2 to 70 mass percent. When component (D) is not included, the blending amount of component (B) is preferably 10 to 90 mass percent of the total composition, more preferably 30 to 70 mass percent. When component (D) is included, the blending amount of component (B) is preferably 1 to 80 mass percent of the total composition, more preferably 2 to 30 mass percent.

[0064] The component (B) is used in the second liquid and is not contained in the first liquid. If the component (B) is contained in the first liquid, the storage stability will be poor and the first liquid will harden during storage at room temperature. Therefore, if the component (B) is contained, the first liquid cannot be stored at room temperature.

[0065] [Component (C)] Component (C) is a metal compound capable of catalyzing a [2+2+2] cycloaddition reaction, and is blended as a catalyst for curing the curable silicone composition of the present invention. Herein, "capable of catalyzing a [2+2+2] cycloaddition reaction" means having catalytic activity for a [2+2+2] cycloaddition reaction. Hereinafter, this metal compound will also be referred to simply as a "catalyst," "metal catalyst," etc.

[0066] The metal compound of component (C) can be composed of a central metal atom, a ligand, and a counter ion. Examples of central metal atoms include those from Groups 4 to 12. Specific examples include those from Group 4 (titanium (Ti), zirconium (Zr), and hafnium (Hf)), Group 5 (vanadium (V), niobium (Nb), and tantalum (Ta)), Group 6 (chromium (Cr), molybdenum (Mo), and tungsten (W)), Group 7 (manganese (Mn), rhenium (Re)), Group 8 (iron (Fe), ruthenium (Ru), and osmium (Os)), Group 9 (cobalt (Co), rhodium (Rh), and iridium (Ir)), Group 10 (nickel (Ni), palladium (Pd), and platinum (Pt)), and Group 12 (zinc (Zn)). Among these, Ti, Nb, Ta, Co, Rh, Fe, Ru, Ir, or Pd is preferred, and Co, Rh, or Pd is more preferred. The central metal atom may be one type or two or more types, and when two or more types are used, they may all be the same metal or a combination of different metals.

[0067] The ligand is not particularly limited, and may be carbonyl (CO), ammonia, water, F － , Cl － ,Br － , I － Halide ions such as cyanide ions (CN － ), P.F. ６ － , B.F.４ － , NO ３ － , B.P.h. ４ － , ClO ４ － anions such as ammonium, sulfonium, and phosphonium; onium cations such as ammonium, sulfonium, and phosphonium; organic phosphorus compounds such as triphenylphosphine and 1,2-bis(diphenylphosphino)ethane; cyclopentadienyl (Cp) groups; pentamethylcyclopentadienyl (Cp) groups; ＊ ) group, cyclooctadiene (COD) group, cyclooctatriene (COT) group, norbornene group, norbornadiene group, and other olefins; dibenzylidene acetone, and other α,β-unsaturated ketones; acetyl group, benzoyl group, and other acyl groups; acetylacetone (acac), and other β-diketones; acetoethyl acetate, and other β-ketoesters; alkylamines; alkylenediamines; aniline; pyridine, and other amines; and alkoxy groups. Among these, carbonyl (CO), halide ions, cyclopentadienyl (Cp) group, triphenylphosphine, and dibenzylidene acetone are preferred. The ligand may be a monodentate ligand or a multidentate ligand (bidentate or higher).

[0068] The counter ion is not particularly limited, and may be a halide ion, a cyanide ion, a carbonate ion, or PF , which can also serve as a ligand. ６ － , B.F. ４ － , NO ３ － , B.P.h. ４ － , ClO ４ － and onium cations such as ammonium, sulfonium, and phosphonium. － is more preferred.

[0069] Particularly preferred metal compounds capable of catalyzing the [2+2+2] cycloaddition reaction are cyclopentadienylcobalt(I) dicarbonyl, tetrakis(triphenylphosphine)palladium(0), tris(dibenzylideneacetone)dipalladium(0), and tris(triphenylphosphine)rhodium(I) chloride.

[0070] The metal compound may be used by diluting it, for example, by dissolving or dispersing it in a solvent, as needed. As such a solvent, known solvents may be used, for example, alcohols such as methanol, ketones such as acetone, hydrocarbon solvents such as hexane, toluene, and xylene, halogenated hydrocarbon solvents such as methylene chloride, chloroform, and 1,2-dichloroethane, esters such as ethyl acetate, and solvents having a kinematic viscosity of 10 to 50,000 mm at 25°C, both ends of which are blocked with trimethylsilyl groups. ２ In particular, polysiloxanes having a kinematic viscosity at 25°C of 10,000 to 50,000 mm ２ By dispersing or diluting a metal compound in dimethylpolysiloxane of formula (I) or (II), separation and sedimentation of the metal compound during storage can be prevented.

[0071] The concentration of the metal compound in the solvent (catalyst concentration) may be set as needed, for example, to 0.01 to 10% by mass, preferably 0.1 to 5% by mass, calculated as the mass of the central metal. A desired composition can be prepared by adding the diluted solution in an amount sufficient to contain a metal compound capable of catalyzing the [2+2+2] cycloaddition reaction described below.

[0072] The amount of the metal compound capable of catalyzing the [2+2+2] cycloaddition reaction should be an effective amount as a catalyst, i.e., an effective amount necessary to promote the curing reaction and cure the curable silicone composition of the present invention. Preferably, the amount is 0.1 to 10,000 ppm, more preferably 1 to 5,000 ppm, and even more preferably 10 to 3,000 ppm by mass, calculated as the central metal atom, relative to the total composition. If the amount of catalyst is equal to or greater than the lower limit, the catalytic effect can be obtained, and if it is equal to or less than the upper limit, the catalytic effect is sufficient and economical.

[0073] The component (C) is used in the first liquid and is not contained in the second liquid.

[0074] [Component (D)] The curable silicone composition of the present invention can optionally contain an inorganic or organic filler as component (D). Component (D) can impart various properties to the curable silicone composition of the present invention, such as thermal conductivity, heat resistance, reinforcing properties, electrical conductivity, and design properties. Component (D) is preferably a filler made of at least one material selected from the group consisting of metals, metal oxides, metal hydroxides, metal nitrides, metal carbides, carbon allotropes, resins, dyes, and pigments. Examples of fillers include metals such as aluminum, silver, copper, and metallic silicon; metal oxides such as aluminum oxide (alumina), zinc oxide, magnesium oxide, silicon dioxide, cerium oxide, and iron oxide; metal hydroxides such as aluminum hydroxide and cerium hydroxide; metal nitrides such as aluminum nitride and boron nitride; metal carbides such as silicon carbide; diamond, graphite, and carbon. Examples of suitable materials include carbon allotropes such as carbon nanotubes and graphene, resins such as silicone resin powder, dyes such as indigo, and pigments such as red iron oxide. In order to impart thermal conductivity to the composition, it is preferable to use aluminum, silver, alumina, zinc oxide, and aluminum nitride. In order to impart heat resistance, it is preferable to use cerium oxide, cerium hydroxide, and iron oxide. In order to impart reinforcement, it is preferable to use silicon dioxide such as hydrophobic fumed silica. In order to impart conductivity, it is preferable to use silver, copper, and carbon allotropes. In order to impart smoothness, it is preferable to use silicone resin powder. In order to impart design properties, it is preferable to use dyes and pigments such as indigo and red iron oxide.

[0075] The average particle size of the filler is preferably 500 μm or less, more preferably 300 μm or less, and even more preferably 150 μm or less, since a more uniform composition can be obtained if the average particle size is 500 μm or less, more preferably 300 μm or less, and even more preferably 150 μm or less. It is also preferably 0.01 μm or more, particularly preferably 0.1 μm or more. The average particle size can be determined, for example, as the volume average value (or median diameter) in particle size distribution measurement by laser diffraction. The shape of the filler is not particularly limited and may be spherical, irregular, acicular, plate-like, or the like.

[0076] The amount of component (D) blended is preferably 5,000 parts by mass or less, more preferably 3,000 parts by mass or less, and even more preferably 2,000 parts by mass or less, based on 100 parts by mass of the total of components (A) and (B), because the viscosity is not too high and the composition is easy to handle and homogeneous. When component (D) is blended, the amount is preferably 0.1 part by mass or more, and even more preferably 1 part by mass or more.

[0077] [Component (E)] The curable silicone composition of the present invention may contain a hydrolyzable organopolysiloxane, various modified silicones, or a hydrolyzable organosilane for the purposes of improving the filling properties of the filler or imparting adhesive properties to the composition. Furthermore, a solvent may be added to adjust the viscosity of the composition. Furthermore, to prevent deterioration of the curable silicone composition, a conventionally known antioxidant such as 2,6-di-tert-butyl-4-methylphenol may be added as needed. Furthermore, a flame retardant, an anti-settling agent, a thixotropy improver, or the like may be added as needed. When these are added, the amount is preferably 0.1 to 10.0 mass% of the total composition.

[0078] [Method of Producing Silicone Composition] The method of producing the curable silicone composition of the present invention will now be described. The method of producing the curable silicone composition of the present invention is not particularly limited, but is a two-component curable silicone composition consisting of a first liquid containing the above-mentioned component (A) and the above-mentioned component (C) but not the above-mentioned component (B), and a second liquid containing the above-mentioned component (B) but not the above-mentioned component (C). In other words, the first liquid contains the above-mentioned components (A) and (C), and optionally also the component (D) and other components, and the second liquid contains the above-mentioned component (B), and optionally also the component (A) and / or the component (D), and the production process involves mixing the curable silicone compositions of the respective liquids.

[0079] Examples of mixing devices used in preparing the first and second liquids include mixers such as ATSUKI MIXER (registered trademark of THINKY CORPORATION), TORIMIX, TWINMIX, and PLANETARY MIXER (all registered trademarks of mixers manufactured by Inoue Seisakusho Co., Ltd.), ULTRAMIXER (registered trademarks of mixers manufactured by Mizuho Kogyo Co., Ltd.), and HIBIS DISPERMIX (registered trademarks of mixers manufactured by Tokushu Kika Kogyo Co., Ltd.), or manual mixing using a spatula or the like at 25° C. for typically 3 minutes to 24 hours, preferably 5 minutes to 12 hours, and particularly preferably 10 minutes to 6 hours. Deaeration may be performed during mixing.

[0080] In the composition of the present invention, the mixing ratio of the first liquid to the second liquid is preferably approximately equal by mass, and specifically, the ratio of the first liquid to the second liquid is preferably in the range of 1:0.5 to 1:2, more preferably 1:0.75 to 1:1.25, even more preferably 1:0.9 to 1:1.1, and particularly preferably 1:0.95 to 1:1.05. The device for mixing the first liquid and the second liquid is not limited to a static mixer such as a static mixer, and may be a known mixer such as a planetary mixer or a paddle mixer.

[0081] The curable silicone composition of the present invention preferably has an absolute viscosity measured at 25°C of 0.1 to 1,000 Pa·s, more preferably 1 to 700 Pa·s, and even more preferably 5 to 500 Pa·s. A viscosity of 0.1 Pa·s or higher improves workability, such as good shape retention. A viscosity of 1,000 Pa·s or lower improves workability, such as easy discharge and application. The above viscosity can be obtained by adjusting the blend of the above-mentioned components. In the present invention, the absolute viscosity is the value measured at 25°C using a Malcolm viscometer (rotor A at 10 rpm, shear rate 6 [1 / s]).

[0082] The cured silicone product of the present invention is obtained by curing the above-mentioned curable silicone composition. The method for producing this cured silicone product is characterized by comprising the steps of mixing a two-component curable silicone composition consisting of a first liquid containing the above-mentioned components (A) and (C) but not the above-mentioned component (B) with a second liquid containing the above-mentioned component (B) but not the above-mentioned component (C), and curing the resulting mixture.

[0083] There are no particular restrictions on the curing conditions for curing the curable silicone composition of the present invention, but the heating temperature is usually 0 to 200°C, preferably 10 to 150°C, and particularly preferably 20 to 100°C. Electrical and electronic components, which are particularly susceptible to high temperature heating, and modules containing circuit boards on which these components are mounted, can be cured at 100°C or below.

[0084] The curing time is usually 3 minutes to 72 hours, preferably 5 minutes to 48 hours, and particularly preferably 10 minutes to 24 hours. There are no particular restrictions on the state of the curable silicone composition after curing, and examples include gel, low-hardness rubber, and high-hardness rubber.

[0085] The silicone cured product of the present invention is an elastic material, and since the silicone itself has excellent heat resistance and chemical resistance, it is useful as a silicone elastomer used as a coating agent, sealing agent, or encapsulant for semiconductor elements.

[0086] The curable silicone composition of the present invention is a liquid silicone composition when used, and can be cured under mild conditions in the presence of a catalyst to form a silicone elastomer.

[0087] The present invention employs a [2+2+2] cycloaddition reaction of alkynes, which uses a metal catalyst to form carbon-carbon bonds between multiple bonds. The [2+2+2] cycloaddition reaction forms an aromatic ring from three triple bonds, and is a highly useful reaction that produces no by-product gases during the reaction. Furthermore, by selecting the appropriate catalyst, it is possible to achieve both the desired workability and curing characteristics.

[0088] In particular, the composition of the present invention cures via a catalytic [2+2+2] cycloaddition reaction, which provides superior curability and yields cured products with better properties than conventional radical-based addition reactions, hydrosilylation-based addition reactions, and condensation reactions. Specifically, the composition exhibits the following unprecedented curing properties: (I) unlike radical addition reactions, high temperatures are not required for the generation of initiating species, and the composition can be cured at room temperature or by heating. It is also resistant to curing inhibition by oxygen, resulting in excellent surface curability; (II) the composition has a different addition reaction mechanism from hydrosilylation, making it less susceptible to curing defects even when contaminated with or comes into contact with sulfur, phosphorus, nitrogen compounds, water, organometallic salts, and the like; and (III) unlike condensation reactions, the composition can be cured at room temperature without the use of moisture in the air, and does not generate gas or cause volumetric shrinkage during curing, resulting in excellent deep curing.

[0089] The curable silicone composition of the present invention can be cured under mild conditions of 100°C or below, even when using a catalyst that is stable at room temperature, and therefore can be cured even when using heat-sensitive parts that cannot be exposed to high temperatures during mounting, making it highly useful as a material used in the periphery of electric and electronic parts and semiconductor elements. If a highly active catalyst is used, smooth curing can be achieved even under milder conditions.

[0090] The present invention will be described in more detail below with reference to examples and comparative examples, but the present invention is not limited to the following examples. In the following, the kinematic viscosity at 25°C is a value measured as described above, the catalyst concentration is a mass-based value converted into the central metal atom relative to the entire composition, the average particle size is a volume-based average value obtained by measuring particle size distribution using a laser diffraction method, and in the structural formulas described in the examples, Me represents a methyl group.

[0091] First, the following components were prepared to prepare the curable silicone composition of the present invention: (A) Component A-1: ​​a silicone polymer having both ends capped with ethynyl groups and a kinematic viscosity of 600 mm at 25°C. ２ / s Dimethylpolysiloxane A-2: Both ends are blocked with trimethylsilyl groups, and the kinematic viscosity at 25 ° C is 500 mm ２ / s dimethylpolysiloxane (B) Component B-1: Dimethylpolysiloxane having a kinematic viscosity of 450 mm at 25°C represented by the following formula (4) ２ / s organopolysiloxane B-2: A kinematic viscosity at 25 ° C. represented by the following formula (5) of 80 mm ２ / s B-3: A kinematic viscosity at 25 ° C. represented by the following formula (6) of 140 mm ２ / s Component (C) C-1: a solution of tris(dibenzylideneacetone)dipalladium(0) dissolved in methylene chloride (catalyst concentration: 5% by mass); C-2: a solution of tris(dibenzylideneacetone)dipalladium(0) capped at both ends with trimethylsilyl groups and having a kinematic viscosity of 50,000 mm at 25°C; ２ / s dimethylpolysiloxane solution (catalyst concentration: 5 mass %) (D) component D-1: aluminum oxide powder having an average particle size of 10 μm D-2: zinc oxide powder having an average particle size of 0.4 μm (E) component E-1: hydrolyzable organosilane C represented by the following formula (7) １０ H ２１ Si(OMe) ３ (7)

[0092] [Examples 1 to 4, Comparative Examples 1 and 2] Preparation of Curable Silicone Compositions [1] Curable silicone compositions were prepared by manually mixing the components (A) to (C) using a spatula in the amounts shown in Table 1 below. The properties of the resulting silicone compositions were confirmed when they were cured under the temperature conditions shown in Table 1 below. The results are shown in Table 1.

[0093]

[0094] From the above results, the silicone compositions of Examples 1 to 4 of the present invention can be cured to a rubber-like state within 24 hours at a relatively low temperature of less than 100°C. Comparative Example 1 shows that when the organopolysiloxane (B), which satisfies the requirements of the present invention, is not included, curability at low temperatures is significantly poor. Furthermore, Comparative Example 2 shows that when components (B) and (C) coexist in the first liquid, the storage stability is poor and the composition cures during storage at room temperature, making it impossible to store at room temperature. Therefore, the two-component curing silicone composition of the present invention can be cured to a rubber-like state at a low temperature of 100°C or less when the first and second liquids are mixed by mixing a metal catalyst capable of catalyzing a [2+2+2] cycloaddition reaction into the first liquid and an organopolysiloxane having a specific structure into the second liquid. Each liquid can be stored at room temperature.

[0095] [Examples 5 to 10, Comparative Examples 3 and 4] Preparation of Curable Silicone Compositions [2] Curable silicone compositions were prepared by mixing the above components (A), (B), (C), (D), and (E) in the amounts shown in Tables 2 and 3 below using a Thinky Mixer. The properties of the resulting two-component curable silicone compositions were confirmed when they were cured under the temperature conditions shown in Tables 2 and 3 below. The results are shown in Tables 2 and 3.

[0096]

[0097]

[0098] From the above results, the silicone compositions of Examples 5 to 10 of the present invention can be cured to a rubber-like state within 48 hours at relatively low temperatures below 100°C. Examples 5 to 8 show that the requirements for component (A) can be met even when either (A-1) or (A-2) is used alone. Examples 9 and 10 show that the requirements can also be met when component (A) is a mixture of (A-1) and (A-2). Comparative Example 3 shows that when the organopolysiloxane component (B), which satisfies the requirements of the present invention, is not included, low-temperature curing is significantly poor. Furthermore, Comparative Example 4 shows that when component (B) and component (C) coexist in the first liquid, storage stability is poor and the composition hardens during storage at room temperature, making it impossible to store at room temperature. Therefore, even when the two-component curing silicone composition of the present invention contains a large amount of filler, by mixing a metal catalyst capable of catalyzing a [2+2+2] cycloaddition reaction into the first component and an organopolysiloxane having a specific structure into the second component, the first and second components can be mixed together and cured into a rubber-like state at low temperatures of 100°C or less, and each component can be stored at room temperature.

[0099] This specification includes the following inventions.

[0100] [1]: A two-component curing silicone composition, comprising: (A) an organopolysiloxane comprising the following component (A-1) and / or component (A-2): (A-1) an organopolysiloxane having at least one alkynyl group or nitrile group per molecule; and (A-2) an organopolysiloxane having the following average composition formula (R １ ３ SiO １／２ ) ａ (R １ ２ SiO ２／２ ) ｂ (R １ SiO ３／２ ) ｃ (SiO ４／２ ) ｄ (1) (wherein, R １are each independently an unsubstituted or substituted monovalent hydrocarbon group, a is a number of 2 or more, and a + b + c + d is a number of 2 or more. However, in the case of a linear organopolysiloxane compound, a = 2, b is 2 or more and 1,200 or less, and c = d = 0. In the case of a branched organopolysiloxane compound, a is a number of 2 or more, b is 2 or more and 1,200 or less, and c or d is 1 or more.) and the kinematic viscosity at 25°C represented by ２ (B) an organopolysiloxane compound having a substituent represented by the following general formula (2) in the molecule: (In the formula, R ２ are independently a substituted or unsubstituted monovalent hydrocarbon group or a hydrogen atom, R ３ are independently substituted or unsubstituted divalent hydrocarbon groups, R ４ is a divalent linking group.) and (C) a metal compound capable of catalyzing a [2+2+2] cycloaddition reaction. A two-component curing silicone composition, characterized in that, among the above-mentioned components, the first component contains (A) and (C) but does not contain (B), and the second component contains component (B) but does not contain component (C). [2]: R in the general formula (2) ３ [3]: The two-component curing silicone composition according to [1], wherein R in the general formula (2) is a methylene group. ２is a hydrogen atom. [4]: ​​The two-component curing silicone composition according to [1], wherein component (B) is an organopolysiloxane compound having, on average, two or more substituents represented by general formula (2) per molecule. [5]: The two-component curing silicone composition according to any one of [1] to [4], further comprising (D) at least one inorganic or organic filler in an amount of 0.1 to 5,000 parts by mass per 100 parts by mass of components (A) and (B) combined. [6]: The two-component curing silicone composition according to [5], wherein component (D) is a filler composed of one or more materials selected from the group consisting of metals, metal oxides, metal hydroxides, metal nitrides, metal carbides, carbon allotropes, resins, dyes, and pigments. [7]: A cured silicone product obtained by curing the two-component curing silicone composition according to any one of [1] to [4]. [8]: A silicone cured product obtained by curing the two-component curing silicone composition described in [5].

[0101] The present invention is not limited to the above-described embodiments. The above-described embodiments are merely examples, and anything that has substantially the same configuration as the technical idea described in the claims of the present invention and that exhibits similar effects is included within the technical scope of the present invention.

Claims

A two-component curing silicone composition, (A) an organopolysiloxane comprising the following component (A-1) and / or component (A-2): (A-1) an organopolysiloxane having at least one alkynyl group or nitrile group per molecule, and (A-2) The following average composition formula (1) (R １ ３ SiO １／２ ) ａ (R １ ２ SiO ２／２ ) ｂ (R １ SiO ３／２ ) ｃ (SiO ４／２ ) ｄ (1) (In the formula, R １ are each independently an unsubstituted or substituted monovalent hydrocarbon group, a is a number of 2 or greater, and a + b + c + d is a number of 2 or greater. However, in the case of a linear organopolysiloxane compound, a = 2, b is 2 or greater and 1,200 or less, and c = d = 0. In the case of a branched organopolysiloxane compound, a is a number of 2 or greater, b is 2 or greater and 1,200 or less, and c or d is 1 or greater. The kinematic viscosity at 25°C is 1 to 100,000 mm ２ / s organopolysiloxane, and (B) an organopolysiloxane compound having a substituent represented by the following general formula (2) in the molecule: (In the formula, R ２ are independently a substituted or unsubstituted monovalent hydrocarbon group or a hydrogen atom, R ３ are independently substituted or unsubstituted divalent hydrocarbon groups, R ４ is a divalent linking group; and (C) A metal compound capable of catalyzing a [2+2+2] cycloaddition reaction a two-component curing silicone composition, characterized in that, of the above-mentioned components, the first component contains components (A) and (C) but does not contain component (B), and the second component contains component (B) but does not contain component (C). 　 R in the general formula (2) ３ 2. The two-component curing silicone composition according to claim 1, wherein is a methylene group. 　 R in the general formula (2) ２ 2. The two-component curing silicone composition according to claim 1, wherein: is a hydrogen atom.

2. The two-component curing silicone composition according to claim 1, wherein component (B) is an organopolysiloxane compound having, on average, two or more substituents represented by general formula (2) per molecule. The two-component curing silicone composition according to any one of claims 1 to 4, further comprising (D) at least one inorganic or organic filler in an amount of 0.1 to 5,000 parts by mass per 100 parts by mass of the combined total of components (A) and (B).

6. The two-component curing silicone composition according to claim 5, wherein component (D) is a filler made of one or more materials selected from the group consisting of metals, metal oxides, metal hydroxides, metal nitrides, metal carbides, carbon allotropes, resins, dyes, and pigments. 　 A cured silicone product obtained by curing the two-component curing silicone composition according to any one of claims 1 to 4. 　 A cured silicone product obtained by curing the two-component curing silicone composition according to claim 5.

Images