Curable silicone composition, cured product thereof, and method for producing same

Abstract

[Problem] To provide a composition capable of containing a large amount of functional inorganic fillers, wherein the composition is sufficiently hard at room temperature in an uncured state, has sufficient hardness even when compression-molded into pellets or tablets, has a low melt viscosity at high temperatures, and provides a cured product having excellent hot melt properties, gap filling properties, and uniformity, characterized by high fluidity at high temperatures. [Solution] This hot-melt curable silicone composition contains: (A) a thermosetting silicone; and (B) a functional filler mix that contains three types of functional inorganic fillers respectively having average particle diameters of 0.01-1.0 μm, 1.0-10.0 μm, and more than 10.0 μm in specific mass%, and that is treated with one or more types of surface treating agents selected from a specific long-chain alkyl group-containing hydrolyzable silane and a specific straight-chain organopolysiloxane. Also provided are a molded product and uses of said composition.

Description

Curable silicone composition, cured product thereof, and method for producing the same

[0001] The present invention relates to a curable silicone composition and a method for producing the same, which has hot-melt properties, maintains sufficient hardness in the uncured state even when compressed and molded into pellets or tablets, has low melt viscosity at high temperatures, high fluidity and gap-fill properties, excellent moldability, and yields a cured product with excellent mechanical strength. The invention also relates to a cured product made from the curable silicone composition, a method for molding the cured product, and applications of semiconductor devices and the like equipped with the cured product. In this invention, the property of being solid at 25°C but exhibiting viscosity at 180°C is referred to as "hot-melt property."

[0002] Curable silicone compositions are widely used in various industrial fields because they cure to form cured products with excellent heat resistance, cold resistance, electrical insulation, weather resistance, water repellency, and transparency. These cured silicone products are generally less prone to discoloration and exhibit less deterioration in physical properties compared to other organic materials, making them suitable as encapsulants for optical materials and semiconductor devices. On the other hand, in recent years, hot-melt curable silicone compositions have become widely used as encapsulants for optical materials and semiconductor devices due to their ease of handling and other advantages.

[0003] In Patent Documents 1 and 2, the applicant has proposed a hot-melt, granular, curable silicone composition for molding, mainly composed of a resin-like silicone, which can be used for the aforementioned applications. This composition can be applied to transfer molding processes by being formed into pellets or tablets. However, when these compositions are treated as solids and molded into pellets or tablets, they lack sufficient hardness and have poor compression moldability at room temperature.

[0004] There are several methods to increase the hardness of the resulting curable silicone composition, such as reducing the amount of added liquid components or increasing the amount of functional inorganic fillers. However, generally, some material properties, such as melting properties or the mechanical strength of the resulting cured product, tend to be sacrificed, and it is not easy to increase the hardness of the composition while balancing various physical properties. In addition, if the hardness of the cured molded product and the compression moldability at room temperature are kept high, the hot melt properties deteriorate, and in particular, the melt viscosity may be impaired, resulting in insufficient fluidity at high temperatures.

[0005] International Publication No. 2018 / 030288 Brochure International Publication No. 2018 / 235491 Brochure

[0006] The object of the present invention is to provide a curable silicone composition that can contain a large amount of functional inorganic filler, has sufficient hardness in the uncured state even when compressed and molded into pellets or tablets, exhibits excellent hot-melt properties, gap-filling properties and uniformity characterized by low melt viscosity at high temperatures and high fluidity, and yields a cured product with excellent mechanical strength, which can be suitably used in molding or sealing processes such as transfer molding, compression molding, and press molding, and provides a curable silicone composition with excellent moldability, production efficiency and homogeneity thereof. Furthermore, the present invention aims to provide a cured product obtained by curing the curable silicone composition, a semiconductor device component made of the cured product, a semiconductor device having the cured product, and a method for molding the cured product.

[0007] As a result of diligent research, the present inventors have found that the present invention comprises (A) one or more thermosetting silicones selected from hydrosilyl-reactive silicones and radical-reactive silicones, and (B) (B1) a functional inorganic filler having an average particle size in the range of 0.01 to 1.0 μm; (B2) a functional inorganic filler having an average particle size in the range of 1.0 to 10.0 μm; and (B3) a functional inorganic filler having an average particle size greater than 10.0 μm, wherein when the sum of components (B1) to (B3) is 100% by mass, the content of component (B1) is in the range of 3 to 20% by mass, the content of component (B2) is in the range of 5 to 35% by mass, and the content of component (B3) is in the range of 45 to 92% by mass, and component (B) is (B') (B'1) structural formula: R Ｌ Si (RO) ３ (In the formula, R Ｌ A long-chain alkyl group-containing hydrolyzable silane represented by (where is an alkyl group having 5 to 20 carbon atoms, and R is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms), and (B'2) structural formula: (Alk)R' ２ SiO-(R') ２ SiO) ｍ -Si(RO) ３ The present invention was completed by finding that the above problems can be solved by a curable silicone composition characterized by being treated with one or more surface treatment agents selected from linear organopolysiloxanes having alkenyl groups and hydrolyzable silyl groups at the molecular termini represented by the formula (wherein Alk is an alkenyl group having 2 to 20 carbon atoms, R is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, R' is independently an alkyl group having 1 to 20 carbon atoms, a halogen-substituted alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, a halogen-substituted aryl group having 6 to 20 carbon atoms, or an aralkyl group having 7 to 20 carbon atoms, and m is a number in the range of 2 to 100), wherein the content of component (B) is 500 parts by mass or more per 100 parts by mass of component (A), and the composition as a whole exhibits hot-melt properties.

[0008] The composition further comprises (C) a polyolefin wax having a melting point of 130°C or less and a viscosity of 100 mPas or more at 140°C, (D) a wax having a melting point of 130°C or less and a viscosity of less than 100 mPas at 140°C, and (E) a RSiO having a melting point in the range of 30-150°C, not having a hydrosilyl reactive functional group containing a carbon-carbon double bond in the molecule, and having a silanol group content of 5.0 mol% or less. ３／２ The material may contain one or more organopolysiloxane resins selected from those containing at least 20 mol% or more of siloxane units represented by the formula (wherein R is a monovalent hydrocarbon group) of the total siloxane units.

[0009] The composition may be in powder form, or it may be homogenized in composition by melt-kneading at a temperature range of 50 to 150°C and then formed into granules. Furthermore, the composition according to the present invention may be further compressed (including in particular tableting) into pellet or tablet form.

[0010] Furthermore, the above-mentioned problems are solved by using the above-mentioned curable silicone composition or the cured product of the compression molded article, as a component for semiconductor devices, and by a method for molding the cured product.

[0011] The present invention provides a curable silicone composition that has a high content of functional inorganic fillers, possesses sufficient hardness in the uncured state even when compressed into pellets or tablets, exhibits low melt viscosity at high temperatures and high fluidity, and forms a cured product that is excellent in hot meltability, gap-filling ability, uniformity, and adheres firmly to a substrate. In particular, the curable silicone composition obtained by the present invention is easy to granulate, pelletize, and tabletize, and has high hardness at room temperature in the uncured compressed molded product, resulting in excellent handling workability and mass production capabilities. Furthermore, the curable silicone composition can be suitably used in molding or sealing processes such as transfer molding, compression molding, and press molding, and the present invention can provide a cured product obtained by curing the curable silicone composition, a semiconductor device component made of the cured product, a semiconductor device having the cured product, and a method for molding the cured product.

[0012] [Silicone Composition for Curing] The silicone composition for curing of the present invention has hot-melt properties as a whole due to the following compositional characteristics and those derived therefrom. The composition is solid at room temperature, but from the viewpoints of handling workability and moldability, it may be a granular composition, and may be in the form of a pellet-shaped molded product or a tablet-shaped molded product obtained by compression molding thereof, and this is preferable. In particular, the composition according to the present invention has sufficient hardness in an uncured state even when compression-molded into a pellet shape or a tablet shape, and has the advantage of low melt viscosity at high temperatures.

[0013] The silicone composition for curing of the present invention includes a combination of (A) a thermosetting silicone and (B) three functional inorganic fillers ((B1) to (B3) components) having a specific particle size range, which are surface-treated with a specific surface treatment agent (component (B')), in a specific mass percentage, and the content of component (B) is 500 parts by mass or more with respect to 100 parts by mass of component (A). The composition according to the present invention further includes (C) a polyolefin wax having a melting point of 130°C or lower and a viscosity of 100 mPa·s or more at 140°C, (D) a wax having a melting point of 130°C or lower and a viscosity of less than 100 mPa·s at 140°C, and (E) a range of 30 - 150°C in melting point, having no hydrosilyl-reactive functional group containing a carbon-carbon double bond in the molecule, and having a silanol group content of 5.0 mol% or less, and may include one or more selected from organopolysiloxane resins containing at least 20 mol% or more of siloxane units represented by RSiO ３／２ (wherein R is a monovalent hydrocarbon group) in all siloxane units, and may also include other optional components.

[0014] [Component (A)] Component (A) is the main agent of the present composition and is a silicone component showing thermosetting properties of hydrosilyl reactivity or radical reactivity. As long as it shows the above reactivity, it may be one component or a mixture of several components. Further, the reactive functional group may be one type or two or more types.

[0015] Component (A) must contain hydrosilylation-reactive groups or radical-reactive groups. Examples of hydrosilylation-reactive groups include C2-C20 alkenyl groups such as vinyl groups, allyl groups, butenyl groups, pentenyl groups, hexenyl groups, heptenyl groups, octenyl groups, nonenyl groups, decenyl groups, undecenyl groups, and dodecenyl groups, as well as silicon-bonded hydrogen atoms. Alkenyl groups are preferred as the hydrosilylation-reactive groups. These alkenyl groups may be linear or branched, and are preferably vinyl groups or hexenyl groups. Component (A) preferably has at least two hydrosilylation-reactive groups in one molecule.

[0016] Examples of groups that bond to silicon atoms other than the hydrosilylation reactive group in component (A) include C1-C20 alkyl groups such as methyl groups, C1-C20 halogen-substituted alkyl groups, C6-C20 aryl groups such as phenyl groups, C6-C20 halogen-substituted aryl groups, C7-C20 aralkyl groups, alkoxy groups, and hydroxyl groups. Methyl groups, phenyl groups, and hydroxyl groups are particularly preferred.

[0017] Furthermore, examples of radical-reactive groups in component (A) include C1-C20 alkyl groups such as methyl groups; C2-C20 alkenyl groups such as vinyl groups and hexenyl groups; acrylic-containing groups such as 3-acryloxypropyl groups and 4-acryloxybutyl groups; methacrylic-containing groups such as 3-methacryloxypropyl groups and 4-methacryloxybutyl groups; and silicon-bonded hydrogen atoms. Alkenyl groups are preferred as radical-reactive groups. These alkenyl groups may be linear or branched, and are preferably vinyl groups and hexenyl groups. It is preferable that component (A) has at least two radical-reactive groups in one molecule.

[0018] Examples of groups that bond to silicon atoms other than radical-reactive groups in component (A) include halogen-substituted alkyl groups having 1 to 20 carbon atoms, aryl groups having 6 to 20 carbon atoms, halogen-substituted aryl groups having 6 to 20 carbon atoms, aralkyl groups having 7 to 20 carbon atoms, alkoxy groups, and hydroxyl groups, and the same groups as described above are also examples. Phenyl groups and hydroxyl groups are particularly preferred. In particular, it is preferable that 10 mol% or more of the total organic groups in the molecule of component (A) are aryl groups, and especially phenyl groups.

[0019] From the viewpoint of imparting practical hot-melt properties and the aforementioned reactivity to this composition, component (A) is (A1) RSiO ３／２ Preferably, the product comprises at least an organopolysiloxane resin containing at least 20 mol% or more of the siloxane units represented by the formula (wherein R is a monovalent hydrocarbon group) and (A2) a curing agent.

[0020] [Component (A1)] Component (A1) is RSiO ３／２ The organopolysiloxane resin contains at least 20 mol% or more of siloxane units represented by the formula (wherein R is a monovalent hydrocarbon group) (hereinafter sometimes simply referred to as "T units") of the total siloxane units, and has the aforementioned thermosetting functional group in its molecule. From the viewpoint of the curing rate of the resulting composition, it is preferable that the thermosetting functional group in component (A1) is either a hydrosilylation reaction or a radical reaction, or both. Furthermore, it is preferable that component (A1) is an organopolysiloxane resin component that has a softening point of 30°C or higher and is itself hot-meltable.

[0021] [Component (A1-1)] Component (A1) is a hot-melt organopolysiloxane resin having a softening point of 30°C or higher and containing carbon-carbon double bond groups (hydrosilylation reactive groups and / or radical reactive groups) in its molecule, and RSiO ３／２It is preferable that the siloxane unit represented by (wherein R is a monovalent hydrocarbon group) is present in an amount of at least 20 mol% of the total siloxane units. Furthermore, it is preferable that component (A1) is a hot-melt organopolysiloxane resin in which at least 10 mol% of the silicon atom-bonded organic groups are aryl groups.

[0022] Examples of such (A1-1) components include MT resins, MDT resins, MTQ resins, MDTQ resins, TD resins, TQ resins, and TDQ resins, which consist of any combination of triorganosiloxy units (M units) (organo groups consisting of only methyl groups, methyl groups and the aforementioned curing-reactive functional groups or phenyl groups), diorganosiloxy units (D units) (organo groups consisting of only methyl groups, methyl groups and the aforementioned curing-reactive functional groups or phenyl groups), monoorganosiloxy units (T units) (organo groups consisting of methyl groups, the aforementioned curing-reactive functional groups, or phenyl groups), and siloxy units (Q units), wherein the content of T units is at least 20 mol% or more of the total siloxane units. Furthermore, component (A1) has a curing-reactive functional group (hydrosilylation-reactive group and / or radical-reactive group) containing at least two carbon-carbon double bonds in its molecule, and it is preferable that 10 mol% or more of all silicon atom-bonded organic groups in the molecule are aryl groups, particularly phenyl groups.

[0023] Preferably, the following (R) is used as component (A1-1). １ ３ SiO １／２ ) ａ (R ２ ２ SiO ２／２ ) ｂ (R ３ SiO ３／２ ) ｃ (SiO ４／２ ) ｄ (R ４ O １／２）ｅ This organopolysiloxane, represented by [formula], is a solid at room temperature but has hot-melt properties, softening as the temperature rises.

[0024] In the formula, each R １ , R ２ , R ３R is a monovalent hydrocarbon group having 1 to 10 carbon atoms independently, provided that at least 2 of the total R groups in one molecule are the curing-reactive functional groups described above, and 70 mol% or more of all curing-reactive functional groups are R １ It is preferable that it be located at R. ４ a is an alkyl group having a hydrogen atom or 1 to 10 carbon atoms; a, b, c, d, and e are numbers satisfying the following conditions: (0.10 ≤ a ≤ 0.40, 0 ≤ b ≤ 0.50, 0.20 ≤ c ≤ 0.90, 0 ≤ d ≤ 0.20, 0 ≤ e ≤ 0.05, where a + b + c + d = 1)

[0025] Furthermore, the preferred content of the functional group with curing reactivity is 10 to 20 mol% of the total R component. Below this range, a cured product with sufficient strength cannot be obtained, and above this range, the cured product tends to become hard and brittle. The functional group with curing reactivity is preferably an alkenyl group, and examples include vinyl group, allyl group, butenyl group, pentenyl group, and hexenyl group. Also, from the viewpoint of imparting suitable hot-melt properties to this component, R １ , R ２ , R ３ At least a portion of these groups is preferably an aryl group, and more preferably a phenyl group. Other monovalent hydrocarbon groups include methyl groups.

[0026] Furthermore, in the formula, a is the general formula: R １ ３ SiO １ / ２ This is a number that represents the proportion of siloxane units represented by the formula, and satisfies 0.10 ≤ a ≤ 0.40, preferably 0.10 ≤ a ≤ 0.30. This is because if a is below the upper limit of the above range, the resulting cured product has good hardness at room temperature, and if it is above the lower limit of the lower limit range, good hot melt properties can be obtained. In the formula, b is the general formula: R ２ ２ SiO ２ / ２ This number represents the proportion of siloxane units expressed by , and satisfies the condition 0 ≤ b ≤ 0.5. This is because good hot-melt properties can be obtained when b is below the upper limit of the above range. Also, c is given by the general formula: R ３ SiO ３ / ２c is a number representing the proportion of siloxane units represented by the formula, and satisfies 0.20 ≤ c ≤ 0.90, preferably 0.25 ≤ c ≤ 0.85. This is because if c is above the lower limit of the above range, the resulting cured product has good hardness at room temperature, while if it is below the upper limit of the above range, the resulting cured product has good mechanical strength. Also, d is a number representing the proportion of siloxane units represented by the general formula: SiO ４ / ２ e is a number representing the proportion of siloxane units represented by the formula R, and is a number that satisfies 0 ≤ d ≤ 0.20, preferably 0 ≤ d ≤ 0.10. This is because when d is below the upper limit of the above range, the mechanical strength of the resulting cured product is good. Also, e is a number that represents the proportion of siloxane units represented by the general formula: R ２ O １ / ２ This number represents the proportion of the units expressed by , and satisfies the condition 0 ≤ e ≤ 0.05. This is because when e is below the upper limit of the above range, the resulting cured product has good hardness at room temperature. In the formula, the sum of a, b, c, and d is 1.

[0027] Component (A1) exhibits hot-melt properties, specifically being non-flowing at 25°C, with a melt viscosity at 150°C of 8000 Pa·s or less, preferably 5000 Pa·s or less, and more preferably in the range of 10 to 3000 Pa·s. Non-flowing means not flowing under no load, and for example, it refers to a state below the softening point measured by the ring-and-ball method for testing the softening point of hot-melt adhesives as specified in JIS K 6863-1994 "Test Method for Softening Point of Hot-Melt Adhesives". In other words, in order to be non-flowing at 25°C, the softening point must be higher than 25°C.

[0028] Component (A), preferably component (A1), and more preferably component (A1-1), may be any organosiloxane resin of any molecular weight as long as it exhibits the aforementioned structure and melting properties. For example, a part of the curing-reactive functional groups (such as alkenyl groups) of an organopolysiloxane having the aforementioned structure may be crosslinked with component (A2) described later to increase the molecular weight, but from the viewpoint of the melting properties of the resulting composition, its molecular weight (Mw) is preferably 20,000 g / mol or less.

[0029] Since component (A1), preferably component (A1-1), is a solid at room temperature as described above, it is preferable to use it as a fine-particle resin or to dissolve it in other components necessary for this composition and use it as a liquid mixture from the viewpoint of ease of handling when mixing with other components.

[0030] When component (A1), preferably component (A1-1), is used in particulate form, the particle size is not limited, but the average primary particle size is preferably in the range of 1 to 5000 μm, 1 to 500 μm, 1 to 100 μm, 1 to 20 μm, or 1 to 10 μm. This average primary particle size can be determined, for example, by observation with an optical microscope or SEM. The shape of the particulate component (A1) is not limited, and examples include spherical, spindle-shaped, plate-shaped, needle-shaped, and irregular shapes, but it is preferable that it be spherical or perfectly spherical in shape because it melts uniformly. In particular, by using perfectly spherical fine particles of component (A1), the process of producing the composition described later by powder mixing or melt kneading can be carried out efficiently.

[0031] When micronizing component (A1), the manufacturing method is not limited, and known methods can be used. Furthermore, when obtaining component (A1) in particulate form, the hydrosilylation reaction catalyst, which is component (A2) described later, may be micronized together with component (A1), and is preferred.

[0032] Specific methods for micronizing component (A1) include pulverizing component (A1), which is solid at room temperature, using a pulverizer, or directly micronizing it in the presence of a solvent. The pulverizer is not limited, but examples include a roll mill, ball mill, jet mill, turbo mill, and planetary mill. Alternatively, component (A1) may be directly micronized in the presence of a solvent, for example, by spraying with a spray dryer, or by micronizing with a twin-screw kneader or belt dryer. When micronizing component (A1), it is preferable to obtain spherical hot-melt organopolysiloxane resin fine particles by spraying with a spray dryer.

[0033] By using a spray dryer or the like, component (A1) can be produced that is perfectly spherical and has an average primary particle size of 1 to 500 μm. The heating and drying temperature of the spray dryer should be set appropriately based on the heat resistance of the organopolysiloxane resin fine particles. In order to prevent secondary aggregation of the organopolysiloxane resin fine particles, it is preferable to control the temperature of the organopolysiloxane resin fine particles to below their glass transition temperature. The organopolysiloxane resin fine particles obtained in this way can be recovered using a cyclone, bag filter, or the like.

[0034] For the purpose of obtaining a homogeneous (A1) component, a solvent may be used in the above step, provided that it does not inhibit the curing reaction. The solvent is not limited, but examples include aliphatic hydrocarbons such as n-hexane, cyclohexane, and n-heptane; aromatic hydrocarbons such as toluene, xylene, and mesitylene; ethers such as tetrahydrofuran and dipropyl ether; silicones such as hexamethyldisiloxane, octamethyltrisiloxane, and decamethyltetrasiloxane; esters such as ethyl acetate, butyl acetate, and propylene glycol acetate monomethyl ether; and ketones such as acetone, methyl ethyl ketone, and methyl isobutyl ketone.

[0035] Furthermore, if a liquid silicone compound at room temperature is used as all or part of component (A2) described later, component (A1) may be dissolved in part of component (A2) before use. The liquid silicone compound exhibits a certain degree of mutual solubility with component (A1), and component (A1) can be dissolved by adding, for example, 10 to 50 parts by mass of a portion of component (A2) to 100 parts by mass of component (A1). By liquefying component (A1), the composition described later can be efficiently produced by powder mixing or melt kneading.

[0036] [Component (A2)] Component (A2) is a curing agent for curing component (A1), and is not limited as long as it can cure component (A1). If component (A1) has a curing-reactive functional group containing a carbon-carbon double bond such as an alkenyl group, component (A2) is an organohydrogenpolysiloxane having at least two silicon-bonded hydrogen atoms in one molecule and a catalyst for hydrosilylation. If component (A1) contains an alkenyl group and a catalyst for hydrosilylation, component (A2) may be only an organopolysiloxane having at least two silicon-bonded hydrogen atoms in one molecule, but a catalyst for hydrosilylation may be used in combination. Furthermore, if component (A1) has an alkenyl group, component (A2) may be an organic peroxide, and an organopolysiloxane having at least two silicon-bonded hydrogen atoms in one molecule may be used in combination. On the other hand, if component (A1) has a silicon-bonded hydrogen atom, component (A2) is an organopolysiloxane having a curing-reactive functional group containing at least two carbon-carbon double bonds such as alkenyl groups in one molecule, and a catalyst for the hydrosilylation reaction. If component (A1) has a silicon-bonded hydrogen atom and contains a catalyst for the hydrosilylation reaction, component (A2) may consist only of an organopolysiloxane having a curing-reactive functional group containing at least two carbon-carbon double bonds such as alkenyl groups in one molecule, but a catalyst for the hydrosilylation reaction may also be used in combination. Furthermore, if component (A1) has a reactive silanol group, a condensation catalyst may also be included. When a condensation reaction is used as the curing reaction, a known thermobase generator may be used as part of component (A2).

[0037] As described above, component (A2) contains a curing catalyst suited to the selected reaction system. However, for the purpose of compositional homogenization, the composition according to the present invention is preferably homogenized by melt kneading or the like in a temperature range of 50 to 150°C, preferably 50 to 120°C. Therefore, from the standpoint of suppressing unintended curing reactions and maintaining the curing reactivity of the curable silicone composition according to the present invention, component (A2) preferably contains a curing catalyst that does not have activity unless subjected to a certain thermal energy stimulus. Specifically, it is a curing agent containing a curing reaction catalyst that shows activity in the composition upon thermal energy stimulation of 80°C or higher, preferably 100°C or higher, and more preferably 120°C or higher, and it is particularly preferable that the curing reaction does not start below these temperatures.

[0038] More specifically, component (A2) preferably contains one or more curing catalysts selected from (A2-1) an organic peroxide with a half-life of 10 hours and a temperature of 80°C or higher, and (A2-2) thermoplastic resin fine particles containing a catalyst for hydrosilylation reactions, with a softening point or glass transition point of 80°C or higher, or a combination thereof. By using component (A2-1) or (A2-2) as part of the curing agent, even when the composition is homogenized and granulated by a heating process such as melt kneading, unintended curing reactions can be effectively suppressed, and the resulting granular composition can achieve both good hot-melt properties and high-temperature curing properties.

[0039] Component (A2-1) is a curing agent preferably used when a radical reaction is used as the curing reaction for this composition, and is an organic peroxide having a half-life of 10 hours at a temperature of 90°C or higher, or 95°C or higher. Examples of such organic peroxides include dicumyl peroxide, di-t-butyl peroxide, di-t-hexyl peroxide, t-butylcumyl peroxide, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, 1,3-bis(tert-butylperoxyisopropyl)benzene, di-(2-t-butylperoxyisopropyl)benzene, and 3,6,9-triethyl-3,6,9-trimethyl-1,4,7-triperoxonane.

[0040] The content of organic peroxides is not limited, but it is preferably in the range of 0.05 to 10 parts by mass, or 0.10 to 5.0 parts by mass, per 100 parts by mass of component (A1).

[0041] Component (A2-2) is a curing agent preferably used when a hydrosilylation reaction is used as the curing reaction for this composition, and may be either fine particles in which a platinum-based catalyst is dissolved or dispersed in a thermoplastic resin, or microcapsule fine particles in which a platinum-based catalyst is contained as a nucleus within a shell of thermoplastic resin. Examples of platinum-based catalysts include platinum black, platinum-supported carbon fine powder, platinum-supported silica fine powder, chloroplatinic acid, alcohol-modified chloroplatinic acid, platinum olefin complex, and platinum alkenylsiloxane complex. The thermoplastic resin used in component (A2-2) is not particularly limited as long as it does not substantially permeate the platinum-based catalyst at least during the production and storage of this composition, and is substantially soluble in the organopolysiloxane, the main component of this composition, but the thermoplastic resin preferably has a softening point or glass transition point of 80°C or higher, and more preferably 120°C or higher. Specifically, silicone resins, polysilane resins, epoxy resins, acrylic resins, methylcellulose resins, and polycarbonate resins can be suitably used, but they must have low solubility in this composition. The softening point is the temperature at which the resin begins to flow due to its own weight or surface tension, and can be measured by observing the pulverized particles with a microscope while raising the temperature at a constant rate. The glass transition point can be measured by a DSC (differential scanning calorimeter). In this invention, it is preferable that either the softening point or the glass transition point is 120°C or higher. This is because if the softening point or glass transition point of the thermoplastic resin is below 120°C, there is a concern that the platinum component will begin to dissolve during the process of uniformly mixing this composition, which will be described later. Furthermore, the average particle size of the platinum-based catalyst-containing thermoplastic fine particles is not limited, but is preferably in the range of 0.1 to 500 μm, and more preferably in the range of 0.3 to 100 μm. This is because it is difficult to prepare platinum-based catalyst-containing thermoplastic resin fine particles whose average particle size is below the lower limit of the above range, while exceeding the upper limit of the above range reduces dispersibility in the curable silicone resin composition.

[0042] The method for preparing such platinum-based catalyst-containing thermoplastic resin fine particles is not limited, and examples include conventionally known chemical methods such as interfacial polymerization and in-situ polymerization, and physical and mechanical methods such as coacervation and liquid-phase drying. In particular, liquid-phase drying and gas-phase drying are preferable because microcapsule fine particles with a narrow particle size distribution can be obtained relatively easily. The fine particles obtained by these methods can be used as is, but it is desirable to wash them with a suitable cleaning solvent to remove the platinum-based catalyst adhering to their surface in order to obtain a curable silicone resin composition with excellent storage stability. A suitable cleaning solvent is one that does not dissolve the thermoplastic resin but has the property of dissolving the platinum-based catalyst. Examples of such cleaning solvents include alcohols such as methyl alcohol and ethyl alcohol, and low molecular weight organopolysiloxanes such as hexamethyldisiloxane. The ratio of the hydrosilylation reaction catalyst to the thermoplastic resin varies greatly depending on the method for producing the granular material, so it is not particularly limited, but it is preferable that the content of the platinum-based catalyst relative to the thermoplastic resin is 0.01% by mass or more. This is because if the platinum-based catalyst content is less than 0.01% by mass, the physical properties of the cured product will be impaired by this composition unless a large amount of platinum-based catalyst-containing thermoplastic resin fine particles are included in the composition.

[0043] The amount of catalyst added for the hydrosilylation reaction is preferably such that the amount of metal atoms in the total composition is in the range of 0.01 to 500 ppm by mass, 0.01 to 100 ppm, or 0.01 to 50 ppm.

[0044] When a hydrosilylation reaction is used as the curing reaction for this composition, component (A2) may contain an organosiloxane component other than component (A1) as a hydrosilylation crosslinking component in addition to the hydrosilylation reaction catalyst (preferably component (A2-2) mentioned above), and it is preferable that it contains (A2-3) organohydrogenpolysiloxane. Its structure is not particularly limited and may be linear, branched, cyclic, or resinous, but from the viewpoint of excellent curing properties of the resulting composition, it is preferable that the terminals have HR ２ SiO １／２Hydrogen diorganosiloxy units (M) Ｈ It is preferable that the organohydrogenpolysiloxane has units (where R is independently a monovalent organic group).

[0045] (A2-3) The organohydrogenpolysiloxane, which is the hydrosilylated crosslinking component, is more specifically preferably an organopolysiloxane in which 20 to 70 mol% of the total silicon atom-bonded organic groups are phenyl groups. This is because if the phenyl group content is above the lower limit of the above range, the resulting cured product has good mechanical strength at high temperatures, while if it is below the upper limit of the above range, the resulting cured product has good mechanical strength.

[0046] In component (A2-3), there are two or more silicon-bonded hydrogen atoms per molecule, providing sufficient crosslinking reactivity for curing and resulting in a good hardness for the resulting cured product. Examples of silicon-bonded organic groups in component (A2-3) include alkyl groups such as methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, cyclopentyl, cyclohexyl, and cycloheptyl groups; aryl groups such as phenyl, tolyl, and xylyl groups; and monovalent hydrocarbon groups without aliphatic unsaturated bonds such as aralkyl groups such as benzyl and phenethyl groups. Preferably, the group is a phenyl group or an alkyl group having 1 to 6 carbon atoms.

[0047] Such a (A2-3) component is (A2-3-1) general formula: HR ４ ２ SiO(R ４ ２ SiO) ｎ SiR ４ ２ A linear organopolysiloxane represented by H, and (A2-3-2) average unit formula: (R ４ SiO ３／２ ) ｐ (R ４ ２ SiO ２／２ ) ｑ (HR ４ ２ SiO １／２ ) ｒ (YiO ４／２ ) ｓ(XO １／２ ) ｔ Two types of branched-chain organopolysiloxanes represented by the formulas are given as examples, and it is preferable to use these two types of (A2-3) components in combination as hydrosilylated crosslinking components.

[0048] In the formula, R ４ R is the same or different phenyl group or alkyl group having 1 to 6 carbon atoms. ４ Examples of alkyl groups include methyl, ethyl, propyl, butyl, pentyl, hexyl, cyclopentyl, and cyclohexyl groups. ４ Of these, the phenyl group content is within the range of 30 to 70 mol%.

[0049] Furthermore, in the formula, n is an integer between 5 and 1,000. Also, in the formula, p is a positive number, q is 0 or a positive number, r is a positive number, s is 0 or a positive number, t is 0 or a positive number, and q / p is a number between 0 and 10, r / p is a number between 0.1 and 5, s / (p+q+r+s) is a number between 0 and 0.3, and t / (p+q+r+s) is a number between 0 and 0.4.

[0050] In such a (A2-3) component, it is preferable to use a combination of component (A2-3-1) and component (A2-3-2) from the viewpoint of easily controlling the curing rate of the composition and the crosslinking density of the resulting cured product. A suitable ratio of the two components per alkenyl group in the entire composition is in the range of (A2-3-1):(A2-3-2) = 0.05 to 0.6:0.4 to 0.95, preferably in the range of 0.05 to 0.5:0.5 to 0.95, and even more preferably in the range of 0.05 to 0.4:0.5 to 0.95.

[0051] (A2) When the above organohydrogenpolysiloxane is used as part of component (A2), its content is not limited, but in order for the composition to cure, it is preferable that the amount is in the range of 0.5 to 20 moles or 1.0 to 10 moles of silicon-bonded hydrogen atoms per mole of alkenyl groups in the composition. The amount of hydrosilylation reaction catalyst used is as described above.

[0052] In the composition according to the present invention, a particularly preferred component (A2) includes the above-mentioned components (A2-2), (A2-3-1), and (A2-3-2), and the composition as a whole has the advantage of effectively suppressing side reactions and unintended curing reactions, and having excellent hot-melt properties and heat-curing properties at high temperatures.

[0053] [Component (B)] Component (B) of the present invention is a characteristic component of the present invention and is a functional inorganic filler mix containing three types of functional inorganic fillers (B1) to (B3) with different particle sizes, each of which is surface-treated with a surface treatment agent (B') selected from specific organosilicon compounds, in a blending ratio of a specific mass %. By using functional inorganic fillers with different particle sizes in a specific mass % (ratio) that have undergone a specific surface treatment, the composition according to the present invention will have sufficient hardness in the uncured state even when compressed into pellets or tablets, and will also have low melt viscosity and fluidity at high temperatures. If functional inorganic fillers or functional inorganic filler mixes that lack the specific surface treatment or do not meet the blending ratio of the present invention are used instead of component (B), the technical effects of the present invention may not be achieved.

[0054] The functional inorganic filler, which is component (B), can impart functionality to the cured product according to the type of inorganic filler, and in particular, it can provide a curable silicone composition that, upon curing, yields a cured product with excellent hardness and toughness at room temperature to high temperatures. In the present invention, the above-mentioned properties can be achieved by adding 500 parts by mass or more of component (B) to 100 parts by mass of component (A). If a harder and tougher cured product is desired, the amount can be blended in the range of 500 to 3000 parts by mass, 650 to 3000 parts by mass, or 800 to 3000 parts by mass. By selecting component (A) and using a combination of components selected from components (C), (D), and (E) described later, the melt viscosity and curability suitable for sealing, transfer molding, compression molding, and press molding can be further optimized when component (B) is highly filled.

[0055] With respect to the cured product of the curable silicone composition according to the present invention, from the viewpoint of achieving a low average coefficient of linear thermal expansion, the total content of component (B) is preferably 50% by volume or more of the total composition, more preferably 60% by volume or more, even more preferably 70% by volume or more, and particularly preferably in the range of 80 to 95% by volume.

[0056] The component (B) according to the present invention contains three types of functional inorganic fillers (B1) to (B3) with different particle sizes in a certain mixing ratio, but the functional inorganic filler components as a whole, including each component or mixture, are (B') (B'1) structural formula: R Ｌ Si (RO) ３ (In the formula, R Ｌ A long-chain alkyl group-containing hydrolyzable silane represented by (where is an alkyl group having 5 to 20 carbon atoms, and R is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms), and (B'2) structural formula: (Alk)R' ２ SiO-(R') ２ SiO) ｍ -Si(RO) ３ It is necessary to treat the material with one or more surface treatment agents selected from linear organopolysiloxanes having alkenyl groups and hydrolyzable silyl groups at their molecular ends, represented by the formula (wherein Alk is an alkenyl group having 2 to 20 carbon atoms, R is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, R' is independently an alkyl group having 1 to 20 carbon atoms, a halogen-substituted alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, a halogen-substituted aryl group having 6 to 20 carbon atoms, or an aralkyl group having 7 to 20 carbon atoms, n is a number in the range of 0 to 2, and m is a number in the range of 2 to 100). If this surface treatment is omitted, or if surface treatment is performed only with surface treatment agents other than component (B'), even if three types of functional inorganic fillers (B1) to (B3) with different particle sizes are used in blending ratios where each is a specific mass%, it may not be possible to achieve low melt viscosity and fluidity at high temperatures, especially when the composition is in the form of a compression molded product.

[0057] (B'1) Component has the structural formula: R Ｌ Si (RO) ３ A long-chain alkyl group-containing hydrolyzable silane represented by the formula, where RＬ is an alkyl group having 5 to 20 carbon atoms, preferably an alkyl group having 7 to 20 carbon atoms, more preferably an alkyl group having 8 to 15 carbon atoms, and particularly preferably a decyl group. R is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and may be a methyl group or an ethyl group. Specific examples of the component (B'1) include decyltrimethoxysilane.

[0058] The component (B'2) is a linear organopolysiloxane having an alkenyl group and a hydrolyzable silyl group at the molecular terminals represented by the structural formula: (Alk)R' ２ SiO-(R' ２ SiO) ｍ -Si(RO) ３ In the formula, Alk is an alkenyl group having 2 to 20 carbon atoms, and examples thereof include a vinyl group, an allyl group, and a hexenyl group. R is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and may be a methyl group or an ethyl group. Each R' is independently an alkyl group having 1 to 20 carbon atoms, a halogen-substituted alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, a halogen-substituted aryl group having 6 to 20 carbon atoms, or an aralkyl group having 7 to 20 carbon atoms. Industrially, preferably, it is a phenyl group or an alkyl group having 1 to 6 carbon atoms (particularly a methyl group). m corresponds to the average degree of polymerization of the diorganosiloxane units excluding both terminals of the linear organopolysiloxane which is the component (B'2), and from the viewpoint of surface treatment properties, it is a number in the range of 2 to 100, preferably a number in the range of 2 to 50, and particularly preferably a number in the range of 2 to 40. Note that the component (B'2) may be a mixture of two or more kinds of linear organopolysiloxanes having different values of m. Specific examples of the component (B'2) include a dimethylpolysiloxane having a viscosity of 23 mPa·s at 25°C, represented by the formula: Me ２ ViSiO(Me ２ SiO) ２９ Si(OMe) ３ (In the formula, Me is a methyl group and Vi is a vinyl group).

[0059] Component (B') consists of one or more components selected from the above-mentioned components (B'1) and (B'2), or a mixture thereof, and other surface treatment agents such as silazane, methylhydrogenpolysiloxane, silicone resin, and metal soap may be used in combination, as long as they contain the above-mentioned components.

[0060] With respect to component (B), in order to achieve the above blending amount, and to ensure that the composition maintains sufficient hardness in the form of a compression molded product, while achieving low melt viscosity and fluidity at high temperatures, and further achieving a low average coefficient of linear expansion for the resulting cured product, the amount of component (B') used (= processing amount) is preferably in the range of 0.1 to 2.0 mass%, 0.1 to 1.0 mass%, and 0.2 to 0.8 mass%, when the sum of the three types of functional inorganic fillers (B1) to (B3) with different particle sizes is taken as 100 mass%. By processing the functional inorganic fillers (B1) to (B3) or mixtures thereof with the above processing amount of component (B'), there is an advantage that component (B) can be stably blended into the composition at a high volume percent. Furthermore, the surface treatment method is arbitrary, and any desired method can be used, such as a uniform mixing method using mechanical force (dry method) or a wet mixing method using a solvent.

[0061] The present invention is characterized in that, with respect to the resulting curable silicone composition (particularly a compression molded product), while ensuring hardness at room temperature, its melting properties at high temperatures are enhanced by using a combination of three components (B1) to (B3) with different particle size distributions in component (B). Specifically, component (B) contains: (B1) a functional inorganic filler with an average particle size in the range of 0.01 to 1.0 μm; (B2) a functional inorganic filler with an average particle size in the range of 1.0 to 10.0 μm; and (B3) a functional inorganic filler with an average particle size exceeding 10.0 μm, in a specific mass ratio described later.

[0062] Component (B1) is a functional inorganic filler with an average particle size of 0.01 to 1.0 μm, represented as D50. The presence of submicron-sized particles increases the oil absorption capacity of component (B), effectively increasing the hardness of the resulting curable silicone composition. Furthermore, since the submicron-sized particles can fill in between components (B2) and (B3) described later, they can promote close packing of component (B), thereby improving the high-temperature melting properties of the resulting curable silicone composition.

[0063] The amount of component (B1) added is in the range of 3 to 20% by mass, when the sum of components (B1) to (B3) is 100% by mass. If it is below the lower limit of the above range, the curable silicone composition will not harden at room temperature, and if it is above the upper limit of the above range, the close packing of component (B) will be disrupted, and the high-temperature melting properties of the resulting curable silicone composition may be impaired.

[0064] Component (B2) is a functional inorganic filler with an average particle size of 1.0 to 10 μm, represented as D50. Component (B2) is a functional inorganic filler of a size between the submicron-sized component (B1) and the component (B3) described later. If the amount of component (B1) added is increased too much, it disrupts the close packing of component (B), significantly degrading the melting properties of the resulting curable silicone composition. Component (B2), like component (B1), has the effect of increasing the oil absorption of the entire component (B), but because its particle size is larger than that of component (B1), it can be added in relatively large quantities without disrupting the close packing of component (B). This makes it possible to effectively increase the hardness at room temperature without impairing the melting properties at high temperatures of the curable silicone composition obtained by using component (B2).

[0065] The amount of component (B2) added is in the range of 5 to 35% by mass, when the sum of components (B1) to (B3) is 100% by mass. If it is below the lower limit of the above range, the resulting curable silicone composition will not harden at room temperature, and if it is above the upper limit of the above range, the close packing of component (B) will be disrupted, and the high-temperature melting properties of the resulting curable silicone composition may be impaired.

[0066] Component (B3) is a functional inorganic filler with an average particle size of 10 μm or more, represented as D50. Component (B3) consists of relatively large particles with a small specific surface area, resulting in low oil absorption and therefore a low effect on increasing the hardness of the resulting curable silicone composition at room temperature. However, unlike components (B1) and (B2), it allows for high-filling of the composition of the present invention. High-filling of the functional inorganic filler is necessary to ensure the mechanical properties and low thermal expansion coefficient of the cured product made from the composition of the present invention; therefore, component (B3) is an essential component for the present invention.

[0067] The amount of component (B3) added is in the range of 45 to 92% by mass, preferably in the range of 45 to 90% by mass, when the sum of components (B1) to (B3) is taken as 100% by mass. If it is below the lower limit of the above range, component (B) cannot be highly packed into the composition of the present invention, and the resulting cured product cannot be given excellent mechanical properties or low thermal expansion characteristics. If it is above the upper limit of the above range, the close packing of component (B) may be disrupted, and the high-temperature melting characteristics of the resulting curable silicone composition may be impaired.

[0068] The component (B), which includes components (B1) to (B3) surface-treated with component (B'), is preferably a functional filler that does not have a softening point or does not soften below the softening point of component (A1). It may also be a component that improves the handling workability of the composition and imparts mechanical properties or other properties to the cured product of the composition. Examples of component (B) include reinforcing fillers, pigments (especially black or white pigments), thermally conductive fillers, conductive fillers, phosphors, and mixtures of at least two of these. In order to achieve a high volume percent filling amount, it is preferable that at least 40% of the total component (B) contains reinforcing fillers with an average particle size of 10.0 μm or more. Examples of organic fillers include silicone resin-based fillers, fluororesin-based fillers, and polybutadiene resin-based fillers. The shape of these fillers is not particularly limited and may be spherical, spindle-shaped, flattened, needle-shaped, plate-shaped, irregularly shaped, etc.

[0069] When this composition is used as a sealant, protective agent, adhesive, or light reflector, it is preferable to include a reinforcing filler as component (B) in order to impart mechanical strength to the cured product and improve its protective or adhesive properties. Examples of such reinforcing fillers include fumed silica, precipitated silica, fused silica, calcined silica, fumed titanium dioxide, quartz, calcium carbonate, diatomaceous earth, aluminum oxide, aluminum hydroxide, zinc oxide, zinc carbonate, glass beads, glass powder, talc, clay and mica, kaolin, silicon carbide, silicon nitride, aluminum nitride, carbon black, graphite, titanium dioxide, calcium sulfate, barium carbonate, magnesium carbonate, magnesium sulfate, barium sulfate, cellulose, and aramid. Furthermore, these reinforcing fillers may be surface-treated with organoalkoxysilanes such as methyltrimethoxysilane; organohalosilanes such as trimethylchlorosilane; organosilazanes such as hexamethyldisilazane; siloxane oligomers such as α,ω-silanol group-blocked dimethylsiloxane oligomers, α,ω-silanol group-blocked methylphenylsiloxane oligomers, and α,ω-silanol group-blocked methylvinylsiloxane oligomers. Furthermore, as reinforcing fillers, fibrous inorganic fillers such as calcium metasilicate, potassium titanate, magnesium sulfate, sepiolite, zonolite, aluminum borate, rock wool, glass fiber, carbon fiber, asbestos fiber, metal fiber, wollastonite, attapulgite, sepiolite, aluminum borate whiskers, potassium titanate fibers, calcium carbonate whiskers, titanium oxide whiskers, and ceramic fibers may be used; as well as fibrous fillers such as aramid fibers, polyimide fibers, and poly(p-phenylenebenzobisoxazole) fibers.In addition, plate-shaped or granular fillers such as talc, kaolin clay, calcium carbonate, zinc oxide, calcium silicate hydrate, mica, glass flakes, glass powder, magnesium carbonate, silica, titanium dioxide, alumina, aluminum hydroxide, magnesium hydroxide, barium sulfate, calcium sulfate, calcium sulfite, zinc borate, barium metaborate, aluminum borate, calcium borate, sodium borate, aluminum nitride, boron nitride, silicon nitride, or crushed fibrous fillers may be used.

[0070] Component (B) may include silicone microparticles that do not have hot-melt properties, which can improve or adjust stress relaxation properties as desired. Examples of silicone microparticles include non-reactive silicone resin microparticles and silicone elastomer microparticles, but silicone elastomer microparticles are preferably exemplified from the viewpoint of improving flexibility or stress relaxation properties.

[0071] Silicone elastomer nanoparticles are crosslinked linear diorganopolysiloxanes mainly composed of diorganosiloxy units (D units). Silicone elastomer nanoparticles can be prepared by crosslinking reactions of diorganopolysiloxanes, such as hydrosilylation reactions or silanol group condensation reactions. In particular, they can be preferably obtained by crosslinking an organohydrogenpolysiloxane having silicon-bonded hydrogen atoms in its side chains or terminals with a diorganopolysiloxane having unsaturated hydrocarbon groups such as alkenyl groups in its side chains or terminals under a hydrosilylation catalyst. Silicone elastomer nanoparticles can take various shapes, such as spherical, flattened, and irregular shapes, but they are preferably spherical from the viewpoint of dispersibility, and more preferably perfectly spherical. Examples of commercially available silicone elastomer nanoparticles include the "Torefil E series" and "EP Powder series" from Toray Dow Corning, and the "KMP series" from Shin-Etsu Chemical Co., Ltd. Furthermore, the silicone elastomer fine particles may be surface-treated. The surface of the silicone elastomer particles may be modified with functional groups or coated with silicone resin or the like. Additionally, the elastomer fine particles may be made of acrylonitrile butadiene rubber, isoprene, styrene butadiene rubber, ethylene propylene rubber, or the like.

[0072] Furthermore, when this composition is used as a wavelength conversion material for LEDs, a phosphor may be incorporated as component (B) to convert the emission wavelength from the photosemiconductor element. There are no particular limitations on the phosphor, and examples include yellow, red, green, and blue emitting phosphors made of oxide-based phosphors, oxynitride-based phosphors, nitride-based phosphors, sulfide-based phosphors, oxysulfide-based phosphors, etc., which are widely used in light-emitting diodes (LEDs). Examples of oxide-based phosphors include YAG-based green to yellow emitting phosphors containing cerium ions (yttrium, aluminum, garnet); TAG-based yellow emitting phosphors containing cerium ions (terbium, aluminum, garnet); and silicate-based green to yellow emitting phosphors containing cerium or europium ions. Examples of oxynitride-based phosphors include sialon-based red to green emitting phosphors containing europium ions (silicon, aluminum, oxygen, nitrogen). Examples of nitride-based phosphors include calcium, strontium, aluminum, silicon, and nitrogen-based cousin-type red phosphors containing europium ions. Examples of sulfide-based phosphors include ZnS-based green phosphors containing copper and aluminum ions. Examples of oxysulfide-based phosphors include Y-type phosphors containing europium ions. ２ O ２ Examples include S-type red light-emitting phosphors. In this composition, two or more of these phosphors may be used in combination.

[0073] Furthermore, the composition may contain a thermally conductive filler or a conductive filler to impart thermal or electrical conductivity to the cured product. Examples of such thermally conductive or conductive fillers include metal fine powders such as gold, silver, nickel, copper, aluminum, tin, lead, zinc, bismuth, and antimony; fine powders obtained by depositing or plating metals such as gold, silver, nickel, and copper onto the surface of fine powders such as ceramics, glass, quartz, and organic resins; metal compounds such as aluminum oxide, magnesium oxide, aluminum nitride, boron nitride, and zinc oxide; graphite; and mixtures of two or more of these. When electrical insulation is required for the composition, metal oxide powders or metal nitride powders are preferred, and aluminum oxide powder, zinc oxide powder, or aluminum nitride powder are particularly preferred.

[0074] Furthermore, the composition may contain pigments to give color to the cured product. Examples of such pigments include white pigments, black pigments, or other colorants.

[0075] The white pigment is a component that imparts whiteness to the cured product and improves its light reflectivity. By incorporating this component, the cured product obtained by curing the composition can be used as a light reflector for light-emitting / optical devices. Examples of this white pigment include metal oxides such as titanium dioxide, aluminum oxide, zinc oxide, zirconium oxide, and magnesium oxide; hollow fillers such as glass balloons and glass beads; and others such as barium sulfate, zinc sulfate, barium titanate, aluminum nitride, boron nitride, and antimony oxide. Titanium dioxide is preferred due to its high light reflectivity and opacity. Aluminum oxide, zinc oxide, and barium titanate are also preferred due to their high light reflectivity in the UV region. The average particle size and shape of this white pigment are not limited, but the average particle size is preferably in the range of 0.05 to 10.0 μm, or in the range of 0.1 to 5.0 μm. Furthermore, this white pigment may be surface-treated with a silane coupling agent, silica, aluminum oxide, etc.

[0076] Examples of black pigments or other colorants include black titanium dioxide, pitch (the residue obtained when tar is distilled from the dry distillation of organic materials such as petroleum, coal, and wood), carbon black, acetylene black, and red iron oxide. If the content of metal impurities needs to be reduced, acetylene black can be suitably used. In addition, black dyes such as anthraquinone dyes (sometimes written as "anthraquinone"), azine dyes, azo dyes, disazo dyes, and chromium complex salt dyes may be included, and when used in combination with yellow dyes such as methine dyes, disazo dyes, azocobalt complex dyes, and azochrome complex dyes, the color can be made to resemble that of a black pigment.

[0077] Also, when it is desired to improve the laser marking property of the resulting cured product, black titanium oxide and pitch can be suitably used. By using these, it is possible to suppress the excessive increase in the absorption of laser energy by the pigment during laser marking. For this reason, it is possible to suppress the occurrence of overly deep portions in the printing due to the disappearance of the pigment by the laser. Also, carbonization is easily suppressed. That is, it is possible to suppress the variation in the maximum depth with respect to the average depth and reduce the variation in the depth profile of the printing.

[0078] Black titanium oxide exists as Ti ｎ O （２ｎ－１） (n is a positive integer). As the black titanium oxide Ti ｎ O （２ｎ－１） used in this embodiment, it is preferable to use those in which n is 4 or more and 6 or less. By setting n to 4 or more, the dispersibility of the pigment in the resin composition can be improved. On the other hand, by setting n to 6 or less, the laser marking property can be improved. Here, the pigment preferably contains at least one of Ti ４ O ７ , Ti ５ O ９ , and Ti ６ Os １１ . Also, pitch is a residue obtained by distilling tar obtained by the dry distillation of organic substances such as petroleum, coal, and wood. Pitch as a pigment is not particularly limited, for example, it is petroleum pitch or coal pitch. Also, as pitch, isotropic pitch, mesophase pitch, or mesophase spheres generated by cooling mesophase pitch and separated as quinoline-insoluble matter can be used. Among these, from the viewpoint of improving the laser marking property and the dispersibility in the sealing resin composition, it is more preferable to use mesophase spheres.

[0079] Furthermore, the composition may optionally contain a thermally expandable filler. By incorporating a thermally expandable filler, the volume expansion rate of the composition according to the present invention can be improved, and uneven distribution of the composition can be reduced. Preferably, the thermally expandable filler has a core-shell structure, and a volatile expanding agent is contained inside the shell of the core-shell structure. Here, a volatile expanding agent is a substance that generates gas at a temperature below the softening point of the shell, and the thermally expandable filler has a structure in which the volatile expanding agent is contained as a core agent inside a shell that has gas barrier properties, so that the volatile expanding agent becomes gaseous due to heat and the shell softens and expands. Examples of such components are exemplified in, for example, Japanese Patent Application Publication No. 2020-084094, and FN-100SSD, FN-80GSD, etc. manufactured by Matsumoto Oil & Fat Pharmaceutical Co., Ltd. are available.

[0080] When a cured product obtained by curing this composition is used in magnetic components such as compacted magnetic needles, coils, and electromagnetic wave shielding materials, magnetic particles may be included as component (B). Such magnetic particles may contain one or more elements selected from the group consisting of Fe, Cr, Co, Ni, Ag, and Mn, and in particular, as soft magnetic particles, magnetic particles made of iron (Fe), Fe-Si alloy, Fe-Al alloy, Fe-Ni alloy, Fe-Co alloy, Fe-Si-Al alloy, Fe-Si-Cr alloy, Fe-Cr alloy, carbonyl iron, stainless steel, etc. may be included, and from the standpoint of availability, magnetic particles made of carbonyl iron may also be used. These magnetic particles may be surface-treated with silane compounds, titanate compounds, aluminate compounds, or partially hydrolyzed products thereof, similar to the inorganic fillers described above, which may prevent deactivation of the curing catalyst and crosslinking agent and improve storage stability. In addition, these magnetic particles may have a surface coating layer containing a siloxane polymer, for example, as described in Japanese Patent Application Publication No. 2021-036013.

[0081] [Component (C)] Component (C) is an optional component of the curable silicone composition according to the present invention, but when the content of component (B) in the composition is 500 parts by mass or more per 100 parts by mass of component (A), it is a component that improves the demolding properties of the cured product obtained by curing the composition while achieving a high content of functional inorganic filler.

[0082] Specifically, component (C) is a polyolefin-based wax having a melting point of 130°C or lower and a melt viscosity of 100 mPas or higher at 140°C. Specific examples include polyethylene wax, oxidized polyethylene wax, polypropylene wax, oxidized polypropylene wax, and mixtures thereof, but any polyolefin wax that satisfies the above melting point and melt viscosity characteristics is acceptable. Polyolefin waxes that satisfy the above characteristics are widely available commercially from companies such as Sanyo Chemical Industries, Ltd. and Clariant Chemicals Co., Ltd.

[0083] The preferred amount of component (C) will be described later. For component (C) to exhibit sufficient demolding properties, it is preferable that it be kneaded together with the composition at a temperature above or close to its melting point and uniformly dispersed. From the viewpoint of the melting and kneading conditions of the composition described later, the melting point of component (C) must be 130°C or lower, or 120°C or lower, and may be in the range of 60-130°C, 60-125°C, 60-120°C, or 60-120°C. On the other hand, if the melting point of component (C) exceeds the above upper limit, it may not be possible to improve the demolding properties during molding of the cured product. Similarly, from the viewpoint of ensuring the adhesion of the cured product made from the curable silicone composition of the present invention to the substrate, the melt viscosity of component (C) at 140°C must be 100 mPas or higher, and may be in the range of 100-10,000 mPas, 100-7,500 mPas, or 500-5,500 mPas. On the other hand, if the melt viscosity of component (C) at 140°C is below the lower limit, the release properties of the cured product may become excessive, making it impossible to adhere to the substrate or base material. Furthermore, if component (A) is a thermosetting silicone that undergoes an addition curing reaction, particularly a hydrosilylation reaction, it is preferable that the acid value of component (C) be 50 mg KOH / g or less from the viewpoint of minimizing curing inhibition.

[0084] [Component (D)] Component (D) is an optional component used alone or in combination with component (C) in the curable silicone composition according to the present invention. Specifically, component (D) is a wax having a melting point of 130°C or less and a viscosity of less than 100 mPas at 140°C, is low-temperature meltable, and has a melt viscosity at 140°C lower than that of component (C). Waxes that satisfy the above characteristics are widely available commercially from companies such as Sazol Co., Ltd., Riken Vitamin Co., Ltd., and Toa Chemical Co., Ltd.

[0085] Component (D), when used alone or in combination with component (C), allows for a balance between the flowability, demoldability, and adhesion strength of the resulting cured product to the substrate when the composition is molded. However, because component (C) has a very high melt viscosity, it may not be sufficient to adequately improve the low melt viscosity and excellent flowability of the composition when melted by itself. Nevertheless, by adding a second wax component with a melting point of 130°C or lower and a melt viscosity of less than 100 mPas at 140°C, it may be possible to achieve all three of the above properties simultaneously.

[0086] Component (D) can be any substance that satisfies its melting point and melt viscosity requirements, such as petroleum waxes like paraffin, natural waxes like carnauba wax, montanic acid ester waxes, fatty acid esters of erythritol derivatives, and synthetic waxes like Fischer-Tropsch wax. Adding even a small amount of component (D) reduces the melt viscosity of the composition and improves its flowability, but its preferred content will be described later. The melting point of component (D) must be 130°C or lower, or 100°C or lower, and may be in the range of 60-120°C, 60-100°C, 60-100°C, or 60-90°C. Furthermore, the melt viscosity of component (D) at 140°C must be less than 100 mPas, and may be in the range of 1-99 mPas, 5-95 mPas, or 5-50 mPas. Furthermore, if component (A) is an addition-curing thermosetting silicone, it is preferable that the acid value of component (D) be 50 mg KOH / g or less, from the viewpoint of minimizing curing inhibition.

[0087] [Amount of components (C) and (D)] The composition of the present invention is mainly used as a encapsulant to seal a substrate, and in this application, it is preferable that the encapsulant adheres firmly to the substrate. For this reason, if the amount of components (C) and (D) added is too large, the adhesive properties of the resulting cured product may be lost. In particular, from the viewpoint of achieving good adhesive properties, demoldability, and flowability of the composition when heated and melted, the amount of component (C) added may be in the range of 0.01 to 0.50 parts by mass, 0.01 to 0.40 parts by mass, or 0.02 to 0.30 parts by mass when the total composition is 100 parts by mass. Similarly, the amount of component (D) added may be in the range of 0.01 to 0.50 parts by mass, 0.01 to 0.40 parts by mass, or 0.02 to 0.30 parts by mass. Furthermore, when the total composition is 100 parts by mass, if the combined amount of component (C) and component (D) is too large, the adhesive strength may be impaired, so it is preferable that the amounts be 0.50 parts by mass or less, 0.40 parts by mass or less, and 0.30 parts by mass or less.

[0088] [Use as a mold release coating agent for mold surfaces] On the other hand, if the composition of the present invention contains components (C) and (D), it can also be used as a mold surface treatment composition for which a mold release coating is applied to the mold surface of a molding machine before molding the composition. In this application, the composition does not need to exhibit adhesion to the substrate, but it is necessary to form a sufficient mold release coating on the mold surface during the molding process. In this case, the suitable amount of component (C) to be added is 0.1 to 5.0 parts by mass, 0.3 to 4.0 parts by mass, or 0.5 to 3.5 parts by mass when the total composition is 100 parts by mass. Depending on the shape of the mold, component (D) may also be used in combination, and the suitable amount of component (D) to be added is 0.1 to 5.0 parts by mass, 0.3 to 4.0 parts by mass, or 0.5 to 3.5 parts by mass when the total composition is 100 parts by mass. When the amounts of components (C) and (D) are within the above ranges, a mold release coating can be effectively applied to the mold surface of the molding machine. Depending on the composition of the encapsulant composition to be actually molded and the shape of the mold, wax components other than components (C) and (D) may be used. Furthermore, by first using a composition with high amounts of component (C) and component (D) to effectively apply a release coating to the mold surface, and then molding a composition with a low total amount of component (C) and component (D) as a sealing agent composition to seal the substrate, the moldability and release properties can be further improved.

[0089] [Component (E)] Component (E) is an optional component of the curable silicone composition according to the present invention, and can effectively increase the hardness at room temperature of granules, pellets, and tablets made from the composition without impairing the melting properties of the composition or the mechanical strength of the resulting cured product, thereby improving productivity and especially mass production.

[0090] Specifically, component (E) has a melting point in the range of 30-150°C, does not contain a hydrosilyl-reactive functional group containing a carbon-carbon double bond within the molecule, and has a silanol group content of 5.0 mol% or less, RSiO ３／２This is an organopolysiloxane resin containing at least 20 mol% or more of siloxane units represented by the formula (wherein R is a monovalent hydrocarbon group) of the total siloxane units. Here, from the viewpoint of imparting suitable hot-melt properties to the component, R is an aryl group, more preferably a phenyl group.

[0091] Component (E) is characterized by not having a hydrosilyl-reactive functional group containing a carbon-carbon double bond within its molecule. This is because if it were to crosslink together with component (A), it would disrupt the balance of the designed crosslinking network, degrading the mechanical strength and heat resistance of the resulting cured product.

[0092] Furthermore, component (E) preferably contains 5.0 mol% or less of silanol groups within its molecule, more preferably 3.0 mol% or less, and even more preferably 1.0 mol% or less of all functional groups. This is because silanol groups have the effect of delaying hydrosilylation, and if their content is high, the curing rate of the resulting composition will be slower, requiring a longer time for thermosetting and molding of the composition, thus reducing productivity.

[0093] In the present invention, component (E) is preferably (E1)RSio ３／２ The organopolysiloxane resin preferably contains at least 20 mol% of the total siloxane units represented by the formula (wherein R is a monovalent hydrocarbon group) (hereinafter sometimes simply referred to as "T units"), has a softening point between 30 and 150°C, and is an organopolysiloxane resin component that is itself hot-melt. In particular, the (E1) component is preferably a hot-melt organopolysiloxane resin in which 10 mol% or more of the (E1-1) silicon atom bonded organic groups are aryl groups.

[0094] Examples of such (E1-1) components include MT resins, MDT resins, MTQ resins, MDTQ resins, TD resins, TQ resins, and TDQ resins, which consist of any combination of triorganosiloxy units (M units) (the organo group is selected from a methyl group, a phenyl group, and an epoxy group-containing group), diorganosiloxy units (D units) (the organo group is selected from a methyl group, a phenyl group, and an epoxy group-containing group), monoorganosiloxy units (T units) (the organo group is a methyl group or a phenyl group, with a phenyl group being preferred), and siloxy units (Q units), wherein the content of T units is at least 20 mol% of the total siloxane units.

[0095] Preferably, the following (R) is used as component (E1-1). １ ３ SiO １／２ ) ａ (R ２ ２ SiO ２／２ ) ｂ (R ３ SiO ３／２ ) ｃ (SiO ４／２ ) ｄ (R ４ O １／２）ｅ This organopolysiloxane, represented by [formula], is a solid at room temperature but has hot-melt properties, softening as the temperature rises.

[0096] In the formula, each R １ , R ２ , R ３ R is independently a monovalent hydrocarbon group having 1 to 10 carbon atoms, excluding hydrosilyl reactive functional groups containing carbon-carbon double bonds. ４ a is an alkyl group having a hydrogen atom or 1 to 10 carbon atoms; a, b, c, d, and e are numbers satisfying the following conditions: (0 ≤ a ≤ 0.40, 0 ≤ b ≤ 0.50, 0.20 ≤ c ≤ 0.90, 0 ≤ d ≤ 0.20, 0 ≤ e ≤ 0.05, where a + b + c + d = 1)

[0097] Furthermore, from the perspective of being able to impart suitable hot-melt properties to this component, R １ , R ２ , R ３ At least a portion of the group is preferably an aryl group, and more preferably a phenyl group. Other monovalent hydrocarbon groups include methyl groups and epoxy group-containing groups.

[0098] Furthermore, in the formula, a is the general formula: R １ ３ SiO １ / ２ This number represents the proportion of siloxane units represented by the formula, and satisfies 0 ≤ a ≤ 0.40, preferably 0 ≤ a ≤ 0.30. This is because if a is below the upper limit of the above range, the resulting cured product has good hardness at room temperature, and if it is above the lower limit of the lower limit range, good hot melt properties can be obtained. In the formula, b is the general formula: R ２ ２ SiO ２ / ２ This number represents the proportion of siloxane units expressed by , and satisfies the condition 0 ≤ b ≤ 0.5. This is because good hot-melt properties can be obtained when b is below the upper limit of the above range. Also, c is given by the general formula: R ３ SiO ３ / ２ c is a number representing the proportion of siloxane units represented by the formula, and satisfies 0.20 ≤ c ≤ 0.90, preferably 0.25 ≤ c ≤ 0.85. This is because if c is above the lower limit of the above range, the resulting cured product has good hardness at room temperature, while if it is below the upper limit of the above range, the resulting cured product has good mechanical strength. Also, d is a number representing the proportion of siloxane units represented by the general formula: SiO ４ / ２ e is a number representing the proportion of siloxane units represented by the formula R, and is a number that satisfies 0 ≤ d ≤ 0.20, preferably 0 ≤ d ≤ 0.10. This is because when d is below the upper limit of the above range, the mechanical strength of the resulting cured product is good. Also, e is a number that represents the proportion of siloxane units represented by the general formula: R ２ O １ / ２ This number represents the proportion of the units expressed by , and satisfies the condition 0 ≤ e ≤ 0.05. This is because when e is below the upper limit of the above range, the resulting cured product has good hardness at room temperature. In the formula, the sum of a, b, c, and d is 1.

[0099] Component (E) exhibits hot-melt properties, specifically being non-flowing at 25°C, with a melt viscosity at 150°C of 8000 Pa·s or less, preferably 5000 Pa·s or less, and more preferably in the range of 10 to 3000 Pa·s. Non-flowing means not flowing under no load, and for example, it refers to a state below the softening point measured by the ring-and-ball method for testing the softening point of hot-melt adhesives as specified in JIS K 6863-1994 "Test Method for Softening Point of Hot-Melt Adhesives". In other words, in order to be non-flowing at 25°C, the softening point must be higher than 25°C.

[0100] As mentioned above, component (E) is structurally similar to component (A1), except for the presence or absence of a hardening reactive group. This is because, in order to effectively reduce the melt viscosity of the composition and improve its flowability when melted at high temperatures, component (E) needs to have a certain degree of compatibility with components (A1) and (A2-3). Therefore, even if a component has a softening point of 30 to 150°C, if its compatibility with components (A1) and (A2-3) is not good, the effects of the present invention may not be obtained.

[0101] The composition according to the present invention may contain (F) a curing retarder and (G) an adhesion promoter, to the extent that it does not impair the objective of the present invention.

[0102] Component (F) is a curing retarder, and in particular when the composition is heat-cured by a hydrosilylation reaction, it can effectively suppress side reactions and may further improve the storage stability and pot life when heated and melted of the composition according to the present invention.

[0103] The available curing retarders are not particularly limited in their structure and type, and can be selected from known hydrosilylation reaction inhibitors, such as alkyne alcohols like 2-methyl-3-butyne-2-ol, 3,5-dimethyl-1-hexyne-3-ol, 2-phenyl-3-butyne-2-ol, and 1-ethynyl-1-cyclohexanol; enyne compounds like 3-methyl-3-penten-1-yine and 3,5-dimethyl-3-hexen-1-yine; alkenyl group-containing low molecular weight siloxanes like tetramethyltetravinylcyclotetrasiloxane and tetramethyltetrahexenylcyclotetrasiloxane; and methyl-tris(1,1-dimethyl-2-propynyl Examples include alkynyloxysilanes such as oxy)silane and vinyl-tris(1,1-dimethylpropynyloxy)silane, and bis(alkynyloxysilyl)alkanes such as 1-[tris(1,1-dimethyl-2-propynyloxy)silyl-6-[bis(1,1-dimethyl-2-propynyloxy)methoxysilyl]hexane, 1,6-bis[tris(1,1-dimethyl-2-propynyloxy)silyl]hexane, or mixtures thereof, as proposed by the applicants in International Publication No. 2023 / 190892 and International Publication No. 2023 / 190893, which include bis(alkynyloxysilyl)alkanes represented by the following formula. (In the formula, R １ R is an alkynyl group having 5 to 12 carbon atoms, ２ R is independently an alkyl group having 1 to 3 carbon atoms or a hydrogen atom. ３ (where a is an alkyl group having 1 to 3 carbon atoms independently, a is independently 1, 2, or 3, b is independently 0, 1, or 2, and a+b is 2 or 3, where at least one of b is 1 or 2, and n is an integer from 2 to 20.)

[0104] In the above formula, R １ The formula is: The alkynyl group represented by formula: An alkynyl group represented by the formula: It is preferable that the alkynyl group is represented by .

[0105] Component (F) is particularly preferably a compound having a boiling point of 200°C or higher at atmospheric pressure. The granular composition according to the present invention can be granulated through a heating process such as melt kneading of the composition for the sake of compositional homogenization. However, if a compound with a low boiling point is used as a curing retarder, some or all of the curing retarder may volatilize during the melt kneading process required for granulation, which may prevent the target curing retardation effect from being obtained for the final granular curable silicone composition. Methyl-tris(1,1-dimethyl-2-propynyloxy)silane and bis(alkynyloxysilyl)alkanes have boiling points of 245°C and 300°C or higher, respectively, at atmospheric pressure, and are listed as suitable examples of component (F).

[0106] The amount of component (F) used is arbitrary, but it is preferably in the range of 1 to 10,000 ppm by mass relative to the whole composition.

[0107] Component (G) is an adhesion promoter, and examples include organosilicon compounds having at least one alkoxy group bonded to a silicon atom in one molecule. Examples of this alkoxy group include methoxy, ethoxy, propoxy, butoxy, and methoxyethoxy groups, with methoxy being particularly preferred. Examples of groups other than alkoxy groups that bond to silicon atoms in organosilicon compounds include halogen-substituted or unsubstituted monovalent hydrocarbon groups such as alkyl groups, alkenyl groups, aryl groups, aralkyl groups, and halogenated alkyl groups; glycidoxyalkyl groups such as 3-glycidoxypropyl and 4-glycidoxybutyl; epoxycyclohexyl alkyl groups such as 2-(3,4-epoxycyclohexyl)ethyl and 3-(3,4-epoxycyclohexyl)propyl; epoxyalkyl groups such as 3,4-epoxybutyl and 7,8-epoxyoctyl; acrylic group-containing monovalent organic groups such as 3-methacryloxypropyl; and hydrogen atoms. The organosilicon compound preferably has an alkenyl group or a group that can react with a silicon-bonded hydrogen atom in the composition, and more specifically, it is preferable that it has a silicon-bonded hydrogen atom or an alkenyl group. Furthermore, since it can impart good adhesion to various substrates, it is preferable that the organosilicon compound has at least one epoxy-group-containing monovalent organic group in one molecule. Examples of such organosilicon compounds include organosilane compounds, organosiloxane oligomers, and alkyl silicates. Examples of molecular structures of these organosiloxane oligomers or alkyl silicates include linear, partially branched linear, branched, cyclic, and network structures, and linear, branched, and network structures are particularly preferred.Examples of organosilicon compounds include silane compounds such as 3-glycidoxypropyltrimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, and 3-methacryloxypropyltrimethoxysilane; siloxane compounds having at least one silicon-bonded alkenyl group or silicon-bonded hydrogen atom and at least one silicon-bonded alkoxy group in one molecule; silane compounds having at least one silicon-bonded alkoxy group or a mixture of a siloxane compound and a siloxane compound having at least one silicon-bonded hydroxyl group and at least one silicon-bonded alkenyl group in one molecule; reaction mixtures of amino group-containing organoalkoxysilane and epoxy group-containing organoalkoxysilane; and organic compounds having at least two alkoxysilyl groups in one molecule, with bonds other than silicon-oxygen bonds between those silyl groups, general formula: R. ａ ｎ Si(OR ｂ ) ４－ｎ (In the formula, R ａ is a monovalent epoxy group-containing organic group, R ｂ Examples include epoxy group-containing silanes or their partially hydrolyzed condensates, vinyl group-containing siloxane oligomers (including those with a linear or cyclic structure) and epoxy group-containing trialkoxysilanes, methyl polysilicate, ethyl polysilicate, and epoxy group-containing ethyl polysilicate. The adhesion-imparting agent is preferably a low-viscosity liquid, and although its viscosity is not limited, it is preferably in the range of 1 to 500 mPa·s at 25°C. The content of the adhesion-imparting agent is also not limited, but it is preferably in the range of 0.01 to 10 parts by mass per 100 parts by mass of the total composition.

[0108] In the present invention, a particularly suitable adhesion-imparting agent is a reaction mixture of an amino group-containing organoalkoxysilane and an epoxy group-containing organoalkoxysilane. Such components improve the initial adhesion of the curable silicone composition to various substrates in contact during the curing process, and especially low-temperature adhesion to unwashed substrates. Such reaction mixtures are disclosed in Japanese Patent Publication No. 52-8854 and Japanese Patent Application Publication No. 10-195085.

[0109] Examples of alkoxysilanes having an amino group-containing organic group that constitute such components include aminomethyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-aminopropylmethyldimethoxysilane, N-(2-aminoethyl)aminomethyltributoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane, and 3-anilinopropyltriethoxysilane.

[0110] Examples of epoxy group-containing organoalkoxysilanes include 3-glycidoxyprolyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, and 2-(3,4-epoxycyclohexyl)ethylmethyldimethoxysilane.

[0111] The ratio of alkoxysilanes having amino group-containing organic groups to alkoxysilanes having epoxy group-containing organic groups is preferably in the range of (1:1.5) to (1:5) in molar ratio, and particularly preferably in the range of (1:2) to (1:4). This component can be easily synthesized by mixing the alkoxysilanes having amino group-containing organic groups and the alkoxysilanes having epoxy group-containing organic groups as described above and reacting them at room temperature or under heating.

[0112] In particular, in the curable hot melt silicone composition of the present invention, when reacting an alkoxysilane having an amino group-containing organic group with an alkoxysilane having an epoxy group-containing organic group by the method described in Japanese Patent Application Publication No. 10-195085, a general formula is obtained by cyclization by an alcohol exchange reaction: {In the formula, R 1 R is an alkyl group, an alkenyl group, or an alkoxy group. 2 The same or different general formulas: (In the formula, R 4 R is an alkylene group or an alkylene oxyalkylene group, 5 R is a monovalent hydrocarbon group, 6 R is an alkyl group, 7 R is an alkylene group, 8 is an alkyl group, an alkenyl group, or an acyl group, and a is 0, 1, or 2. ) is a group selected from the group consisting of groups represented by , R 3 It is particularly preferable to contain a carbasilatran derivative represented as}, where is the same or different hydrogen atom or alkyl group. Examples of such carbasilatran derivatives include carbasilatran derivatives having a silicon atom-bonded alkoxy group or a silicon atom-bonded alkenyl group in one molecule, represented by the following structure. (In the formula, Rc is a group selected from a methoxy group, an ethoxy group, a vinyl group, an allyl group, and a hexenyl group.)

[0113] Furthermore, in the present invention, a silatoran derivative represented by the following structural formula may be used as an adhesion promoter. R in the formula 1 R is the same or different hydrogen atom or alkyl group, in particular, 1 A hydrogen atom or a methyl group is preferred as the R in the above formula. 2 is a hydrogen atom, an alkyl group, and the general formula: -R 4 -Si(OR 5 ) x R 6 (3-x) The same or different group selected from the group consisting of alkoxysilyl group-containing organic groups represented by , however, R2 At least one of these is an organic group containing an alkoxysilyl group. 2 Examples of alkyl groups include methyl groups. 2 In an alkoxysilyl group-containing organic group, R in the formula 4 R is a divalent organic group, and examples include alkylene groups or alkylene oxyalkylene groups, with ethylene groups, propylene groups, butylene groups, methylene oxypropylene groups, and methylene oxypentylene groups being particularly preferred. Also, R in the formula 5 R is an alkyl group having 1 to 10 carbon atoms, preferably a methyl group or an ethyl group. 6 x is a substituted or unsubstituted monovalent hydrocarbon group, preferably a methyl group. In the formula, x is 1, 2, or 3, preferably 3.

[0114] This kind of R 2 Examples of organic groups containing an alkoxysilyl group include the following: -(CH ２ ) ２ Si(OCH) ３ ) ２ (CH ２ ) ２ Si(OCH) ３ ) ２ CH ３ -(CH ２ ) ３ Si(OC) ２ H ５ ) ２ (CH ２ ) ３ Si(OC) ２ H ５ )(CH ３ ) ２ -CH ２ O(CH ２ ) ３ Si(OCH) ３ ) ３ -CH ２ O(CH ２ ) ３ Si(OC) ２ H ５ ) ３ -CH ２ O(CH ２ ) ３ Si(OCH)３ ) ２ CH ３ -CH ２ O(CH ２ ) ３ Si(OC) ２ H ５ ) ２ CH ３ -CH ２ OCH ２ Si(OCH) ３ ) ２ CH ２ OCH ２ Si(OCH) ３ )(CH ３ ) ２

[0115] R in the above equation 3 R is at least one group selected from the group consisting of substituted or unsubstituted monovalent hydrocarbon groups, alkoxy groups having 1 to 10 carbon atoms, glycidoxyalkyl groups, oxyranylalkyl groups, and acyloxyalkyl groups, 3 Examples of monovalent hydrocarbon groups include alkyl groups such as methyl groups, 3 Examples of alkoxy groups include methoxy, ethoxy, and propoxy groups, R 3 Examples of glycidoxyalkyl groups include the 3-glycidoxypropyl group, R 3 Examples of oxyranyl alkyl groups include 4-oxyranylbutyl group and 8-oxyranyloctyl group, R 3 Examples of acyloxyalkyl groups include acetoxypropyl group and 3-methacryloxypropyl group. In particular, R 3 The group is preferably an alkyl group, an alkenyl group, or an alkoxy group, and more preferably an alkyl group or an alkenyl group, with groups selected from methyl, vinyl, allyl, and hexenyl groups being particularly preferred examples.

[0116] The amount of component (G) used is not particularly limited, but from the viewpoint of improving adhesion to difficult-to-bond substrates, it is preferably in the range of 0.1 to 1.0% by mass of the total composition, and more preferably in the range of 0.2 to 1.0% by mass. Furthermore, the amount of component (G) blended may be in the range of 5 to 50 parts by mass, or 5 to 40 parts by mass, per 100 parts by mass of component (A).

[0117] Furthermore, the composition may contain, as long as it does not impair the purpose of the present invention, other optional components such as iron oxide (red iron oxide), cerium oxide, cerium dimethyl silanolate, cerium fatty acid salts, cerium hydroxide, zirconium compounds, and other heat-resistant agents; dyes, pigments other than white, flame retardants, heat-removing agents such as aluminum hydroxide, magnesium hydroxide, zinc borate, zinc molybdate, and phosphazene; ion-scavenging agents and pH adjusters such as hydrotalcite, bismuth oxide, and yttrium oxide; aluminum hydroxide, hydroxyl Flame retardants such as magnesium oxide, zinc borate, zinc molybdate, and phosphazene; antioxidants such as hindered phenol compounds, hindered amine compounds, and thioether compounds; soft magnetic particles such as pure iron, silicon steel, iron-cobalt alloy, iron-nickel alloy, iron-chromium alloy, iron-aluminum alloy, carbonyl iron, stainless steel, or composite materials containing one or more of these; inorganic flame retardants (e.g., hydrated metal compounds such as aluminum hydroxide); halogenated flame retardants; phosphorus-based flame retardants; organometallic salt-based flame retardants; Silicone oil, silicone rubber, polyisoprene, polybutadiene such as 1,2-polybutadiene and 1,4-polybutadiene, styrene-butadiene rubber, acrylonitrile-butadiene rubber, carboxyl-terminated butadiene acrylonitrile rubber, polychloroprene, poly(oxypropylene), poly(oxytetramethylene) glycol, polyolefin glycol, thermoplastic elastomers such as poly-ε-caprolactone, stress-reducing agents such as polysulfide rubber and fluororubber, barium titanate (BaTiO) ３ ), strontium titanate (SrTiO ３ ), lead zirconate titanate (Pb(Zr,Ti)O ３ (Also known as PZT), alumina (Al ２ O ３Also known as: aluminum oxide), zirconia (ZrO ２ (Also known as zirconium dioxide), magnesia (MgO, also known as magnesium oxide), silica (SiO ２ Also known as silicon dioxide), titania (TiO ２ Also known as titanium dioxide, aluminum nitride (AlN), silicon nitride (Si ３ N ４ It may also contain dielectric ceramics such as silicon carbide (SiC), barium zirconate titanate (also known as BCTZ), and polyvinylidene fluoride; metal salt stabilizers such as copper chloride, cuprous iodide, copper acetate, and cerium stearate; antioxidants and heat stabilizers such as hindered amines, hindered phenols, sulfur-containing compounds, acrylates, and phosphorus-based organic compounds; and ultraviolet absorbers, weather stabilizers, and light stabilizers such as benzophenones, salicylates, and benzotriazoles.

[0118] [Granular Curable Silicone Composition] The curable silicone composition according to the present invention is not particularly limited in form as long as it has the above composition, and as described later, it may be molded into pellets or tablets, but even if it contains a large amount of functional inorganic filler, it is preferable to have excellent melting properties and curing properties characterized by high fluidity at high temperatures, and less dust generation, so that the composition is homogenized by melting and kneading each component of the composition in the temperature range of 50 to 150°C and then molded into granules. In other words, the curable silicone composition according to the present invention is preferably a granular curable silicone composition. The granular curable silicone composition (granular molded product) may further be molded into pellets or tablets.

[0119] The granular composition generates less dust, offers excellent handling properties, and exhibits superior uniformity of its components. As a result, its cured product has high hardness, a low coefficient of thermal expansion, and good adhesion to the substrate, making it particularly suitable for use as a sealing, molding, and protective component for semiconductor devices. Furthermore, the granular composition (granular molded product) according to the present invention has the advantage of being able to be efficiently produced by a simple mixing process alone.

[0120] [Composition of the present invention and its compression molded product (especially tablet molded product)] As described above, the curable silicone composition of the present invention is solid at room temperature, and is preferably compositionally homogenized in order that any small amount of component (C), component (D), and component (E) is sufficient to exert its effect, and as described above, it is preferably a curable silicone composition molded in granular form. In particular, by providing a granular form having a certain average particle size, the granular composition can be easily used as a pellet-shaped molded product or a tablet-shaped molded product by compression molding using a known method.

[0121] The curable silicone composition of the present invention, by using component (B) above, is easily molded into granules and has sufficient hardness in the uncured state (hereinafter sometimes referred to as "tablet hardness") even when compressed into pellets or tablets. It also has the advantages of low melt viscosity at high temperatures and high fluidity / gap-filling properties. Due to its high tablet hardness, the curable silicone composition of the present invention can be efficiently produced in the form of a compression molded product and offers excellent handling properties.

[0122] The aforementioned compression molding can be carried out by known means, but tablet molding is particularly convenient. Unlike the case of tablet molding of granular compositions (powder mixtures) that have not undergone melt kneading, such as in Patent Document 1, the granular curable silicone composition according to the present invention has a practically sufficient tablet hardness for the compressed molded product, and compositional uniformity is achieved. Therefore, using this composition not only improves the production efficiency of the tablet molded product, but also has the advantage of being even superior in terms of hot meltability, melt viscosity, and physical properties of the cured product of the resulting tablet molded product. Furthermore, using a granular composition has the advantage of not generating much dust.

[0123] Here, "pellets" and "tablets" are general or common names for granular compressed tablets made from a resin composition. The shape of the pellets / tablets is not limited, but they are usually spherical, ellipsoidal, or cylindrical. The size of the pellets is also not limited, but they may have an average particle diameter or equivalent circle diameter of 500 μm or more, or an average particle diameter or equivalent circle diameter of 1 mm or more.

[0124] [Method for Producing Granular Curable Silicone Composition] This composition is in the form of granules in which the entire composition, including at least the above-mentioned components (A) to (B) and other optional components, is compositionally homogenized beyond the degree of mixing by mere mechanical force. Such a granular composition is preferably obtained by melt-kneading the entire composition with heating, and more specifically, it is preferable to melt-knead components (A) to (B) and other optional components in a single-screw or twin-screw continuous mixer, double-roll mixer, loss mixer, kneader mixer, etc., at a temperature range of 50 to 150°C, and then mold it into granules for use. A specific production method is exemplified below.

[0125] The present invention provides a method for producing a granular curable silicone composition comprising the above-mentioned components (A) to (B), and other optional components, wherein the content of component (B) is 500 parts by mass or more per 100 parts by mass of component (A), a curable silicone composition, which is then melt-kneaded at a temperature range of 50 to 150°C and molded into granules. Here, the average particle size of the granular composition is preferably in the range of 0.05 to 10.0 mm.

[0126] The manufacturing method is not particularly limited as long as it includes a step of forming the composition into granules after melting and kneading, but for example, it includes the following steps 1 to 3: Step 1: A step of kneading the components of the curable silicone composition while heating and melting them in a temperature range of 50 to 150°C. Step 2: A step of cooling the mixture obtained in Step 1 while extruding it. Step 3: A step of cutting or breaking the mixture obtained in Step 2 to form a granular curable silicone composition.

[0127] [Step 1] Step 1 described above is a step of kneading the components of the curable silicone composition of the present invention while heating and melting them in a temperature range of 50 to 150°C. By heating and kneading a mixture that is meltable by heating at a temperature above its softening point, preferably in a temperature range of 50°C to 120°C, the entire composition melts or softens, and components (A) to (B) and any other components can be uniformly dispersed throughout. In particular, by melting and kneading at a temperature higher than or close to the melting points of components (C), (D), and (E), these components can be uniformly dispersed in the system, and their effects can be fully realized.

[0128] The mixing apparatus in step 1 is not limited and can be any batch-type heating and kneading apparatus with heating and cooling functions, such as a kneader, Banbury mixer, Henschel mixer, planetary mixer, two-roll mill, three-roll mill, Ross mixer, or Laboplast mill, or a continuous-type heating and kneading apparatus with heating and cooling functions, such as a single-screw extruder or twin-screw extruder. It is not particularly limited, but should be selected according to the efficiency of the processing time and the ability to control shear heat generation. In terms of processing time, a continuous-type heating and kneading apparatus such as a single-screw extruder or twin-screw extruder may be used, or a batch-type mixer such as a Laboplast mill may be used. However, from the viewpoint of the production efficiency of the granular curable silicone composition, a continuous-type heating and kneading apparatus such as a single-screw extruder or twin-screw extruder is preferably used.

[0129] The mixture is made into granules in step 3 after going through step 2. However, if the temperature is below the lower limit, softening may be insufficient, making it difficult to obtain a molten or softened mixture in which each component is uniformly dispersed even with mechanical force. Such a mixture may lack uniformity of each component, and when the resulting granular curable silicone composition is used in the molding process, a uniform cured product may not be obtained. Conversely, if the temperature exceeds the upper limit, the curing agent may react during mixing, causing the entire mixture to thicken significantly or harden, losing its hot-melt properties and forming a cured product, which is undesirable. For this reason, when using a component for the hydrosilylation reaction as component (A), it is preferable to use a particulate hydrosilylation reaction catalyst (for example, component (A2-2) above) dispersed or encapsulated in a thermoplastic resin whose softening point is above the kneading temperature.

[0130] As for the method of introducing the components of the present invention into the aforementioned kneading apparatus, each component may be supplied separately to the kneading apparatus at a constant rate, or all components may be mixed together in powder form by mechanical force or the like to form a granular curable silicone composition before being introduced into the kneading apparatus.

[0131] [Step 2] Step 2 is the process of discharging the mixture that has been melted and kneaded in Step 1 from the kneader. The mixture may be discharged in any shape, but since the mixture will be cut and broken into granules in Step 3, it is preferable to discharge it in a shape that is easy to cut and break. For example, rod-shaped (strand-shaped) with a diameter of about 0.5 to 5.0 mm or sheet-shaped with a thickness of about 0.5 to 5.0 mm are examples. In order to be granulated in Step 3, it is preferable that the mixture be a non-sticky solid, so the discharged mixture needs to be cooled to around room temperature by natural cooling or rapid cooling. Examples of rapid cooling methods include using a cooler or water cooling.

[0132] [Step 3] Step 3 is a step in which the mixture extruded in Step 2 is cut or destroyed to form granules. If the mixture is hard enough to be destroyed by shear stress alone at room temperature, it can be destroyed and granulated by passing it through a double roll or hammer mill. Here, the size and shape of the granules obtained in Step 3 can be adjusted to some extent by controlling the dimensions of the mixture extruded in Step 2 and the gap between the rolls. In the present invention, there is no limit to the average particle size of the granular molded product, but it is preferable that it be in the range of 0.05 to 10.0 mm from the viewpoint of handling during tablet molding, which will be described later. If the mixture cannot be destroyed with rolls, etc., it is also possible to extrude the mixture as a rod shape in Step 2 and cut it to a predetermined size with a rotary cutter while cooling to obtain granules. By combining components (B1), (B2), and (B3), which are treated with a specific surface treatment agent (B'), which is a characteristic component of the present invention, in a specific mass ratio (%), it is possible to obtain a composition that has sufficient hardness (= tablet hardness) when molded at room temperature in an uncured state, and the productivity of Step 3 is greatly increased.

[0133] The granular curable silicone composition obtained by the manufacturing method of the present invention exhibits excellent flowability during hot melting and is highly homogeneous in composition, making it less prone to non-uniformity or physical movement of the composition during molding processes such as compression molding, press molding, and lamination. Therefore, it is easy to uniformly mold the entire composition, and it has the advantage of being suitably applicable even to molding processes where shear pressure is not generated. In addition, by using the optional components (C) and (D), it exhibits excellent demolding properties during the molding process and strong adhesion to the substrate. Furthermore, the above advantages are not lost even if the granular composition is subjected to secondary molding; therefore, the granular curable silicone composition may be compressed or tablet-molded using a tablet press or the like and used as tablets or pellets for transfer molding. Since the composition of the present invention is sufficiently hard at room temperature, it is expected that the productivity of this tablet-molding process will also increase.

[0134] As described above, the curable silicone composition of the present invention uses components (B1) to (B3), which are functional fillers with different average particle sizes treated with a specific surface treatment agent (B'), in a specific mass ratio (%) as component (B). This results in excellent production efficiency in the granulation process, sufficient tablet hardness in the uncured state even when compressed into pellets or tablets (especially by tablet molding), and low melt viscosity at high temperatures. Therefore, the above manufacturing method allows for the efficient production of pellets and tablets (molded products) with excellent hot-melt properties and curing characteristics, and also provides remarkably good handling.

[0135] [Cured product] The above curable silicone composition, in particular the granular (molded) composition or the tablet molded product thereof, has hot-melt properties, excellent flowability during melting (hot-melt), handling workability and curability, and upon curing, forms a cured product suitable for semiconductor components and the like. Depending on the type of curing agent of component (A2), it is possible to select from various thermosetting reactions, but when component (A2) is selected from a thermal radical polymerization initiator such as an organic peroxide and a hydrosilylation reaction catalyst / hydrosilylation reaction crosslinking agent, it is preferable to cure by heating in the range of 80°C to 200°C. In the present invention, the physical properties of the cured product, such as the coefficient of linear expansion, flexural strength and hardness, can be easily designed to the following preferred ranges from the type of component (A) and the quantitative range of component (B).

[0136] [Coefficient of linear expansion of the cured product] The cured product obtained by curing the above composition has an average coefficient of linear expansion of 30 ppm / °C or less in the range of 25°C to 200°C, preferably 20 ppm / °C or less. Within this range, the difference in average coefficient of linear expansion with the substrate used is low, so residual stress in the resulting integrally molded product can be reduced, and the reliability of the device can be improved.

[0137] [Flexural Strength of Cured Product] Furthermore, since it is suitable as a encapsulant for semiconductors that require high hardness and high strength, the flexural strength of the cured product measured by the method specified in JIS K 6911-1995 "General Test Methods for Thermosetting Plastics" is preferably 15 MPa or higher, or 20 MPa or higher.

[0138] [Hardness of the cured product] Since it is suitable as a protective material for semiconductors and the like, it is preferable that the hardness of the cured product obtained by curing this composition is 20 or higher at 25°C on a Type D durometer. This Type D durometer hardness is determined by a Type D durometer in accordance with JIS K 6253-1997 "Test method for hardness of vulcanized rubber and thermoplastic rubber".

[0139] [Method for molding cured product] This composition (preferably a granular composition and a pelletized or tablet-shaped molded product thereof, the same applies hereinafter) can be cured by a method consisting of at least the following steps (I) to (III): (I) A step of heating the composition to 100°C or higher to melt it; (II) A step of injecting the curable silicone composition softened in step (I) into a mold, or a step of spreading the curable silicone composition obtained in step (I) into the mold by clamping the mold; and (III) A step of curing the curable silicone composition injected in step (II).

[0140] This composition has sufficient tablet hardness for practical use and exhibits low melt viscosity at temperatures above 100°C. Therefore, it has excellent hot-melt properties, flowability, and gap-fill properties under pressure, making it suitable for use in molding methods that include a coating process (so-called mold-underfill method) in which overmolding and underfilling of semiconductor devices are performed in a single step.

[0141] Furthermore, due to the above-described properties, this composition can be suitably used in a molding method that includes a coating step (so-called wafer molding) in which the surface of a semiconductor substrate (including a wafer substrate) on which one or more semiconductor elements are mounted is covered and the gaps between the semiconductor elements are filled with the cured material. In particular, the composition according to the present invention has the advantage of excellent demoldability and adhesion to the substrate of its cured molded product.

[0142] In the above molding process, a transfer molding machine, compression molding machine, injection molding machine, press molding machine, auxiliary ram molding machine, slide molding machine, double ram molding machine, or low-pressure sealing molding machine can be used.

[0143] In step (III) described above, the curable silicone composition injected (applied) in step (II) is cured. The curing method varies depending on the type of component (A2), but when component (A2) is selected from a thermal radical polymerization initiator such as an organic peroxide and a hydrosilylation reaction catalyst / the hydrosilylation reaction crosslinking agent, it is preferable to cure by heating in the range of 80°C to 200°C, and in particular when an organic peroxide is used as component (A2), it is preferable that the heating temperature be 150°C or higher, or 170°C or higher.

[0144] [Uses of the Composition] The curable silicone composition according to the present invention (particularly including granular (molded) composition, and tablet-shaped or pellet-shaped molded products thereof) has sufficient tablet hardness for practical use, good hot-melt properties, excellent flowability during melting (hot-melt), ease of handling, and curability, as well as good demolding properties and adhesion to substrates. Therefore, it is suitable as a encapsulant or underfill agent for semiconductors; a encapsulant or underfill agent for power semiconductors such as SiC and GaN; a encapsulant or light reflector for optical semiconductors such as light-emitting diodes, photodiodes, phototransistors, and laser diodes; and an adhesive or protective agent for electrical and electronic applications. Furthermore, because this composition has hot-melt properties, it is also suitable as a material for transfer molding, compression molding, press molding, or injection molding. In particular, it is suitable for use as a encapsulant for semiconductors using the mold underfill method or wafer molding method during molding.

[0145] As described above, this composition is suitable as a encapsulant for semiconductors, and by replacing some or all of the conventionally known encapsulants (including non-silicone hot-melt encapsulants such as epoxy encapsulants) in molding methods such as overmolding, underfilling, mold-underfilling, and wafer molding, it is possible to manufacture semiconductors and the like in the process of encapsulating semiconductors, etc., by replacing some or all of the conventionally known encapsulants. This composition can be used to manufacture semiconductor packages, power semiconductor modules, MEMS, small integrated devices such as microsensors (fingerprint sensors), magnetic components such as coils containing magnetic particles, flexible substrates (stretchable wiring boards) used in wearable devices, and semiconductor / optical components such as optical waveguides connected to electrical wiring boards and connectors. For example, the curable silicone composition according to the present invention is as follows: JP 2021-097123, JP 2021-024945, JP 2020-132771, JP 2020-132750, JP 2020-125399, JP 2020-123670, JP 2020-084094, JP 2020-088055, JP 2019-006905, JP 2018-188494, JP 2017-179185, JP 2020-023643, JP 2020-063459, JP 2020-090634, JP 2020-088055, The present invention can be used to replace some or all of the encapsulants described in Japanese Patent Publication Nos. 2020-107767, 2021-080411, 2021-036013, 2020-152844, 2020-158684, 2021-019031, 2021-059741, 2020-057775, 2021-015985, 2015-114390, 2016-177106, etc. (especially including silicone elastomer encapsulants, pastes containing functional fillers, and hot-melt encapsulants). Furthermore, if necessary, the technical elements applicable to these encapsulant compositions may be applied to the present invention, and the composition according to the present invention may be adjusted in terms of its composition, the physical properties of the cured product, and its melting characteristics, etc.

[0146] [Uses of Cured Products] The uses of the cured products according to the present invention are not particularly limited, but the curable silicone composition according to the present invention (in particular, including granular (molded) compositions, and tablet-shaped molded products or pellet-shaped molded products thereof) has sufficient tablet hardness for practical use, good hot-melt properties, excellent moldability, and the resulting cured products have excellent adhesive properties, high elastic modulus, and low coefficient of linear expansion. For this reason, the cured products according to the present invention can be suitably used as components for semiconductor devices, and can be suitably used as encapsulating materials for semiconductor elements and IC chips, or as light-reflecting materials for optoelectronic devices.

[0147] The semiconductor device comprising a component made of the cured product of the present invention is not particularly limited, but it is especially preferable that it be a semiconductor device mounted on a power semiconductor device, an optoelectronic semiconductor device, or a flexible semiconductor device that can be stretched or deformed.

[0148] The hot-melt curable silicone composition and its manufacturing method of the present invention will be described in detail with reference to examples and comparative examples. In the formula, Me, Ph, Vi, and Ep represent methyl group, phenyl group, vinyl group, and epoxy group (= 3-glycidoxypropyl group), respectively. The softening point and melt viscosity of the curable silicone composition of each example and comparative example were measured by the following method. Furthermore, the curable silicone composition was heated at 180°C for 2 hours to produce a cured product, and the adhesion strength to various substrates was measured by the following method. The results are shown in Table 1.

[0149] [Softening Point of Curable Silicone Composition] The curable silicone composition was molded into cylindrical pellets measuring φ14 mm × 22 mm. These pellets were placed on a hot plate set to 25°C to 100°C, and a 100-gram load was applied from above for 10 seconds. After removing the load, the deformation of the pellets was measured. The temperature at which the deformation in the height direction was 1 mm or more was defined as the softening point.

[0150] [Melting Viscosity] The melting viscosity of the curable silicone composition at 180°C was measured using a high-pressure flow tester CFT-500EX (manufactured by Shimadzu Corporation) under a pressure of 100 kgf and with a nozzle of 1.0 mm in diameter.

[0151] [Tablet Hardness] A cylindrical tablet made of an uncured curable silicone composition was left at 25°C for 1 hour, and its hardness was measured using a ShoreD hardness tester.

[0152] A main component (silicone mixture (L1)) containing component (A) of the present invention was prepared using the method shown in Reference Example 1. Similarly, spherical hot-melt organopolysiloxane resin fine particles (P1) containing component (A) of the present invention were prepared using the method shown in Reference Example 2.

[0153] [Reference Example 1] In a 1 L flask, (A1) Component, which is a white solid at 25°C and has a melting point of 100°C, average unit formula: (PhSiO ３ / ２ ) ０.８０ (Me ２ Visio １ / ２ ) ０.２０ 100 g of resinous organopolysiloxane represented by (A2-1) component formula: HMe ２ SiO(Ph ２ SiO)SiMe ２ Diphenylsiloxane with dimethylhydrogensiloxy groups sealed at both ends of the molecular chain, represented by H, with a viscosity of 5 mPa·s (silicon atom bonded hydrogen atom content = 0.6 mass%) 3.2 g, (A2-2) Component average unit formula: (PhSiO ３ / ２ ) ０.４ (HMe ２ SiO １ / ２ ) ０.６ A viscous silicone mixture (L1) was obtained by mixing 28.0 g of a branched-chain organopolysiloxane with a viscosity of 25 mPa·s, which has two or more silicon-bonded hydrogen atoms in each molecule (silicon-bonded hydrogen atom content = 0.65 mass%), represented by [formula].

[0154] [Reference Example 2] In a 1 L flask, at 25°C, it is a white solid with the average unit formula: (PhSiO ３ / ２ ) ０.８０ (Me ２ Visio １ / ２ ) ０.２０550 g of the resinous organopolysiloxane represented by [formula] was dissolved in 450 g of toluene to prepare a toluene solution of resinous organopolysiloxane (1). The obtained toluene solution was atomized while removing the toluene by spray drying at 40°C to prepare spherical hot-melt organopolysiloxane resin fine particles (P1). When these fine particles were observed with an optical microscope, the particle size was 5 to 10 μm, and the average particle size was 7.9 μm.

[0155] The details of the components used in the examples and comparative examples are shown below. Note that the units for the amounts of each component used in Table 1 are parts by mass. (A3-1) 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane (half-life of 10 hours at a temperature of 118°C) (A3-2) Thermoplastic polycarbonate resin containing 4000 ppm of Pt(0 valence) 1,3-divinyl-1,1,3,3-tetramethyldisiloxane complex as platinum content (softening point = 150°C) (B1-1) Fused silica with an average particle size of 0.7 μm (B1-2) Sintered alumina with an average particle size of 0.5 μm (B1-3) Rutile-type titanium oxide with an average particle size of 0.3 μm (B1-4) Carbon black with an average particle size of 0.035 μm (B2-1) Fused silica with an average particle size of 1.5 μm (B2-2) Fused silica with an average particle size of 2.4 μm (B2-3) Grinding alumina with an average particle size of 3.0 μm (B3-1) Fused silica with an average particle size of 15.0 μm (B3-2) Fused silica with an average particle size of 30.0 μm (B3-3) Grinding alumina with an average particle size of 12.0 μm (B3-4) Spherical alumina with an average particle size of 38.0 μm (B'-1) Viscosity of 23 mPa·s, formula: Me ２ Visio (Me ２ SiO) ２９ Si(OMe) ３Dimethylpolysiloxane represented by (B'-2) Decyltrimethoxysilane (B'-3c) Methyltrimethoxysilane (for comparative experiment) (C) Polyethylene wax with a melting point of 100°C and a melt viscosity of 1000 mPas at 140°C (D-1) Fatty acid ester wax with a melting point of 70°C and a melt viscosity of 10 mPas at 140°C (D-2) Carnauba wax with a melting point of 80°C and a melt viscosity of 15 mPas at 140°C (E-1) White solid at 25°C with a melting point of 80°C and a silanol content of 0.5 mol%, average unit formula: (PhSiO ３ / ２ ) ０.７８ (Me ２ SiO ２ / ２ ) ０.１４ (MeEpSiO ２ / ２ ) ０.０８ The organopolysiloxane resin (E-2) represented by (PhSiO) is a white solid at 25°C, has a melting point of 100°C, and contains 0.3 mol% silanol. Average unit formula: (PhSiO) ３ / ２ ) ０.７８ (Me ２ SiO ２ / ２ ) ０.２２ The organopolysiloxane resins represented by (F-1) methyltris-1,1-dimethyl-2-propynyloxysilane (boiling point at atmospheric pressure = 245°C) (F-2) 1,6-bis[tris(1,1-dimethyl-2-butyneoxy)silyl]hexane (boiling point at atmospheric pressure = 300°C or higher) (G) bis(trimethoxysilylpropoxymethyl)allylsilatoran

[0156] [Manufacturing Examples (Examples 1-7, Comparative Examples 1-6)] Components (B), (B'), (C), and (D) were added together to a small pulverizer in the ratios shown in the table below, stirred at 100°C for 1 minute, surface-treated component (B), and the pulverizer temperature was returned to 25°C. Next, the liquid silicone mixture (L1) obtained in Reference Example 1, components (A3), (E), (F), and (G) (only in Example 6, P1 and A2-2 were used instead of L1) were added to the small pulverizer in the ratios shown in the table below, stirred at room temperature (25°C) for 1 minute, and a uniform granular curable silicone composition was prepared.

[0157] The obtained curable silicone composition was placed in a kneader mixer set to 100°C and melt-kneaded at a speed of 100 rpm for 1 minute, resulting in a unified, room-temperature solid composition. This solid was then pulverized while being cooled to 0°C to prepare an amorphous granular curable silicone composition. The obtained granular composition was then compressed into tablets to obtain a cylindrical tablet-shaped curable silicone composition. Its properties, details of each component, and the amounts added are shown in Tables 1 and 2.

[0158] *These represent the mass percentage of each component when the sum of components (B1) to (B3) is set to 100% by mass, and correspond to the mass ratio.

[0159] *These represent the mass percentage of each component when the sum of components (B1) to (B3) is set to 100% by mass, and correspond to the mass ratio.

[0160] [Summary] In Examples 1 to 6 of the present invention, by containing three types of functional fillers (B1) to (B3) with different average particle sizes, surface-treated with component (B'), in predetermined amounts, it was possible to achieve low melt viscosity while ensuring hard tablet (uncured) hardness. Furthermore, in Examples 7 and 8, it was found that by further including component (E), it was possible to achieve even lower melt viscosity without reducing tablet hardness.

[0161] On the other hand, while it is generally believed that the melting properties of a composition improve with larger average particle diameters, Comparative Example 1 showed that the composition did not melt at high temperatures with only component (B3), indicating that high filling is not possible with inorganic fillers of a single particle diameter distribution. Furthermore, Comparative Examples 2 to 6 showed that it is difficult to achieve both sufficiently low melt viscosity and tablet hardness with combinations of two functional fillers with different particle diameters, such as combinations of components (B1) and (B3), and combinations of components (B2) and (B3). In addition, Comparative Example 7 showed that even if three or more functional fillers with different average particle diameters are used, the composition will not melt at high temperatures unless it is filled in a predetermined ratio. Furthermore, as shown in Comparative Example 8, if the functional fillers are not treated with a specific surface treatment agent (B'), low melt viscosity cannot be achieved even if components (B1) to (B3) with different particle diameters are added in predetermined amounts.

Claims

(A) One or more thermosetting silicones selected from hydrosilyl-reactive silicones and radical-reactive silicones, and (B) (B1) Functional inorganic fillers having an average particle size in the range of 0.01 to 1.0 μm; (B2) Functional inorganic fillers having an average particle size in the range of 1.0 to 10.0 μm; and (B3) Functional inorganic fillers with an average particle size exceeding 10.0 μm It consists of the above, and when the sum of components (B1) to (B3) is taken as 100% by mass, (B1) The content of component is in the range of 3 to 20% by mass. (B2) The content of component is in the range of 5 to 35% by mass. (B3) Functional inorganic filler having a component content in the range of 45 to 92% by mass. It contains and (B) component is (B') (B'1) Construction formula: R Ｌ Si(RO) ３ (In the formula, R Ｌ (where R is an alkyl group having 5 to 20 carbon atoms, and R is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms.) A long-chain alkyl group-containing hydrolyzable silane represented by, (B'2) Construction formula: (Alk)R' ２ SiO-(R') ２ SiO) ｍ -Si(RO) ３ (In the formula, Alk is an alkenyl group having 2 to 20 carbon atoms, R is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, R' is independently an alkyl group having 1 to 20 carbon atoms, a halogen-substituted alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, a halogen-substituted aryl group having 6 to 20 carbon atoms, or an aralkyl group having 7 to 20 carbon atoms, and m is a number in the range of 2 to 100.) Linear organopolysiloxane having alkenyl groups and hydrolyzable silyl groups at its molecular termini, represented by [formula]. It is treated with one or more surface treatment agents selected from the following: A curable silicone composition characterized in that the content of component (B) is 500 parts by mass or more per 100 parts by mass of component (A), and the composition as a whole exhibits hot-melt properties. (A) Component (A1) RSiO ３／２ An organopolysiloxane resin containing at least 20 mol% or more of siloxane units represented by the formula (wherein R is a monovalent hydrocarbon group) of the total siloxane units, and (A2) Hardener A curable silicone composition according to claim 1, characterized in that it comprises at least [a certain component]. The curable silicone composition according to claim 2, wherein component (A2) is a curing agent containing a curing reaction catalyst that exhibits activity in the composition upon thermal energy stimulation of 80°C or higher. (A2) Component is, (A2-1) Organic peroxides with a half-life of 10 hours and a temperature of 80°C or higher, (A2-2) Thermoplastic resin fine particles containing a catalyst for hydrosilylation reaction, including a thermoplastic resin having a softening point or glass transition point of 80°C or higher. The curable silicone composition according to claim 3, comprising one or more curing agents selected from the above. (A1) At least some or all of the components are (A1-1) having a softening point of 30 °C or higher and having a curing-reactive functional group containing at least one carbon-carbon double bond in the molecule, RSiO ３／２ The curable silicone composition according to claim 2, which is a hot-meltable organopolysiloxane resin containing at least 20 mol% or more of siloxane units represented by (wherein R is a monovalent hydrocarbon group) based on all siloxane units. (A1) At least some or all of the components are (A1-1-1) It has a softening point of 30°C or higher, and has a hardening-reactive functional group containing at least one carbon-carbon double bond in its molecule, and RSiO ３／２ The curable silicone composition according to claim 2, which is a hot-melt organopolysiloxane resin containing at least 20 mol% of the total siloxane units of a siloxane unit represented by the formula (wherein R is a monovalent hydrocarbon group), and wherein 10 mol% or more of the silicon atom-bonded organic groups are aryl groups. The curable silicone composition according to claim 1, wherein component (B) is a reinforcing filler, a pigment, a thermally conductive filler, a conductive filler, a phosphor, magnetic particles, or a mixture of at least two thereof. Furthermore, the curable silicone composition according to claim 1, characterized in that (C) it contains a polyolefin wax having a melting point of 130°C or less and a viscosity of 100 mPas or more at 140°C. Furthermore, the curable silicone composition according to claim 1, characterized in that (D) it contains a wax having a melting point of 130°C or less and a viscosity of less than 100 mPas at 140°C. Furthermore, (E) RSiO has a melting point in the range of 30-150°C, does not contain a hydrosilyl reactive functional group containing a carbon-carbon double bond in its molecule, and has a silanol group content of 5.0 mol% or less. ３／２ The curable silicone composition according to claim 1, characterized by containing an organopolysiloxane resin containing at least 20 mol% or more of siloxane units represented by the formula (wherein R is a monovalent hydrocarbon group) of the total siloxane units. A curable silicone composition according to any one of claims 1 to 10, which is in powder form. A curable silicone composition according to any one of claims 1 to 10, which is in the form of granules. A pellet-shaped molded product or a tablet-shaped molded product obtained by compression molding the curable silicone composition according to claim 11 or claim 12. A cured product obtained by curing a curable silicone composition according to any one of claims 1 to 12, or a pellet-shaped molded product or tablet-shaped molded product according to claim 13. A semiconductor device component comprising the cured product of claim 14. A semiconductor device having the cured product of claim 14. A method for molding a cured product according to claim 14, comprising at least the following steps (I) to (III). (I) A step of heating the curable silicone composition according to any one of claims 1 to 12, or the pelletized molded product or tablet-shaped molded product according to claim 13, to 100°C or higher to melt it; (II) A step of injecting the curable silicone composition softened in step (I) into a mold or a step of clamping the mold to distribute the curable silicone composition obtained in step (I); and (III) A step of curing the curable silicone composition injected in step (II). A method for molding a cured product according to claim 17, comprising a coating step of performing overmolding and underfilling of a semiconductor element in a single step using a cured product obtained by curing a curable silicone composition according to any one of claims 1 to 12, or a pellet-shaped molded product or tablet-shaped molded product according to claim 13. A method for molding a cured product according to claim 17, comprising a coating step of overmolding a semiconductor substrate on which one or more semiconductor elements are mounted, using a curable product obtained by curing a curable silicone composition according to any one of claims 1 to 12, or a pellet-shaped molded product or tablet-shaped molded product according to claim 13, so as to fill the gaps between the semiconductor elements with the cured product.

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