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

Abstract

[Problem] To provide a curable silicone composition suitable for use as an encapsulant for semiconductor devices, the composition having good hot-melt properties and low melt viscosity, thus allowing for excellent handling workability and curing properties during encapsulation, as well as yielding a cured product having excellent mechanical strength and substrate adhesion strength. [Solution] A curable silicone composition and a use thereof, the composition being characterized by comprising (A) a hot-melt organopolysiloxane resin containing a certain proportion of M and T units and having an alkenyl group, (B) an organosiloxane compound containing a specific siloxane unit and at least 10 mass% of an alkenyl group, (C) an organohydrogensiloxane compound, (D) a hydrosilylation catalyst, and (E) 400-3000 parts by mass of a functional inorganic filler with respect to 100 parts by mass in total of components (A) to (D), and being solid at 25°C and having hot-melt properties at a temperature of 200°C or lower.

Description

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

[0001] The present invention relates to a curable silicone composition that has good hot-melt properties and forms a cured product that is particularly excellent in mechanical strength and bonding strength to substrates. The present invention also relates to a cured product made from the silicone composition, a method for molding the cured product, and a semiconductor device comprising the cured product.

[0002] Curable silicone compositions are used in a wide range of industrial fields because they cure to form cured products with excellent heat resistance, cold resistance, electrical insulation, weather resistance, water repellency, and transparency. Cured products of such curable silicone compositions are generally less susceptible to discoloration than other organic materials, and also suffer less deterioration in physical properties, making them suitable as sealants for optical materials and semiconductor devices. Meanwhile, in recent years, from the standpoint of ease of handling and workability, hot-melt curable silicone compositions have been widely used as sealants for optical materials and semiconductor devices.

[0003] Epoxy-based sealants are commonly used in the semiconductor device industry, but epoxy-based materials are known to have inferior heat resistance compared to silicone-based materials, and the mechanical strength of the cured products obtained from silicone-based materials may be inferior to that of epoxy-based materials.

[0004] Amid the recent trend toward smaller semiconductor devices and higher output, the applications of silicone-based sealants with excellent heat resistance have expanded, and the present applicant has proposed hot-melt curable silicone compositions for molding that contain resinous silicone as the main component and can be used for the above-mentioned applications in Patent Documents 1 to 3. Similarly, Patent Document 4 discloses a hot-melt curable composition that mixes an organic skeleton with a silicone component, and Patent Documents 5 and 6 disclose white curable compositions that use resinous silicones with specific structures.

[0005] However, when these silicone-based curable compositions are used as sealants, the mechanical strength of the cured product may be inferior to that of cured products produced using epoxy-based sealants. Therefore, there is a demand for hot-melt curable silicone compositions that provide superior mechanical strength in addition to ease of handling and heat resistance of the cured product.

[0006] International Publication No. 2018 / 030288 Pamphlet International Publication No. 2018 / 235491 Pamphlet Japanese Patent Application Laid-Open No. 2001-19933 International Publication No. 2013 / 051600 Pamphlet Japanese Patent Application Laid-Open No. 2015-74751 Japanese Patent Application Laid-Open No. 2013-221075

[0007] An object of the present invention is to provide a curable silicone composition that has good hot-melt properties, melting characteristics, and curing properties, making it easy to handle during encapsulation, and that provides excellent mechanical strength and bonding strength to substrates in the cured product, making it suitable as an encapsulant for semiconductor devices. Furthermore, the present invention also provides a cured product obtained by curing the curable silicone composition, a semiconductor device component made of the cured product, a semiconductor device comprising the cured product, and a method for molding the cured product.

[0008] As a result of extensive research, the present inventors have discovered that the above-mentioned problems can be solved by a hot-melt curable silicone composition that contains a high content of functional inorganic filler and that is based on a hot-melt organopolysiloxane resin composed of specific siloxane units, as described below, and an organosiloxane compound containing at least a certain amount of alkenyl groups in its molecule, which functions as a crosslink density adjuster.

[0009] More specifically, the above problem is solved by: (A) (R １ ３ SiO １／２ ) ａ (R ２ ２ SiO ２／２ ) ｂ (R ２ SiO ３／２ ) ｃ (SiO ４／２ ) ｄ (R ３ O １／２）ｅ (In the formula, each R １are independently monovalent hydrocarbon groups having 1 to 10 carbon atoms, provided that all R １ At least two of R are alkenyl groups, and each R ２ are independently monovalent hydrocarbon groups having 1 to 10 carbon atoms, not including alkenyl groups; each R ３ is a hydrogen atom or an alkyl group having 1 to 10 carbon atoms; and a, b, c, d, and e are numbers that satisfy the following: 0.10≦a≦0.40, 0≦b≦0.05, 0.30≦c≦0.90, 0≦d≦0.20, 0≦e≦0.05, with the proviso that a+b+c+d=1; １ ３ SiO １／２ ) ａ´ (R ２ ２ SiO ２／２ ) ｂ´ (R ２ SiO ３／２ ) ｃ´ (SiO ４／２ ) ｄ´ (R ３ O １／２）ｅ´ (In the formula, each R １ are independently monovalent hydrocarbon groups having 1 to 10 carbon atoms, provided that all R １ At least two of R are alkenyl groups, and each R ２ are independently monovalent hydrocarbon groups having 1 to 10 carbon atoms, not including alkenyl groups; each R ３is a hydrogen atom or an alkyl group having 1 to 10 carbon atoms; and a', b', c', d', and e' are numbers that satisfy the following: 0.40≦a'≦0.80, 0≦b'≦0.90, 0≦c'≦0.60, 0≦d'≦0.50, 0≦e'≦0.05, with the proviso that a'+b'+c'+d'=1; (C) an organohydrogensiloxane compound having at least two silicon-bonded hydrogen atoms per molecule; (D) a hydrosilylation catalyst in an amount sufficient to carry out a hydrosilylation reaction of the reactive silicone composition; and (E) a functional inorganic filler in an amount of 400 to 3,000 parts by weight per 100 parts by weight of the total of components (A) to (D), This problem can be solved by providing a curable silicone composition that is solid at 25°C and has hot-melt properties at temperatures of 200°C or less.

[0010] The composition may further contain an organosiloxane compound composed of specific siloxane units and containing 10 mass% or more of alkenyl groups, and may contain other optional components. The composition may be in the form of particles, granules, pellets, or a sheet.

[0011] The above problems are also solved by a cured product of the above curable silicone composition, its use as a semiconductor device component, and a method for molding the cured product.

[0012] The curable silicone composition of the present invention has good hot-melt properties and curing characteristics, and the cured product of the composition of the present invention has high hardness from room temperature to high temperatures, a low coefficient of linear expansion, and excellent mechanical strength, as exemplified by high flexural strength, making it tough and providing excellent bonding strength to substrates, making it suitable as an encapsulant for semiconductor devices. Furthermore, the use of the above-mentioned component (B) in combination with the composition provides excellent melting properties, which offers the advantages of excellent gap-filling properties when melted, ease of handling during encapsulation, and curing characteristics. The curable silicone composition of the present invention, which has these properties, can be suitably applied to semiconductor devices in which semiconductor elements are encapsulated together by mold underfill or overmolding.

[0013] Furthermore, such curable silicone compositions have the advantage of being produced efficiently by a simple mixing process alone. Furthermore, the cured products of the present invention are useful as components for semiconductor devices, and the molding method of the present invention has the advantage of being able to efficiently produce these cured products tailored to the intended use.

[0014] [Curable Silicone Composition] The curable silicone composition of the present invention comprises: (A) (R １ ３ SiO １／２ ) ａ (R ２ ２ SiO ２／２ ) ｂ (R ２ SiO ３／２ ) ｃ (SiO ４／２ ) ｄ (R ３ O １／２）ｅ (In the formula, each R １ are independently monovalent hydrocarbon groups having 1 to 10 carbon atoms, provided that all R １ At least two of R are alkenyl groups, and each R ２ are independently monovalent hydrocarbon groups having 1 to 10 carbon atoms, not including alkenyl groups; each R ３ is a hydrogen atom or an alkyl group having 1 to 10 carbon atoms; and a, b, c, d, and e are numbers that satisfy the following: 0.10≦a≦0.40, 0≦b≦0.05, 0.30≦c≦0.90, 0≦d≦0.20, 0≦e≦0.05, with the proviso that a+b+c+d=1; １ ３ SiO １／２ ) ａ´ (R ２ ２ SiO ２／２ ) ｂ´ (R ２ SiO ３／２ ) ｃ´ (SiO ４／２ ) ｄ´ (R ３ O １／２）ｅ´ (In the formula, each R １are independently monovalent hydrocarbon groups having 1 to 10 carbon atoms, provided that all R １ At least two of R are alkenyl groups, and each R ２ are independently monovalent hydrocarbon groups having 1 to 10 carbon atoms, not including alkenyl groups; each R ３ represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms; and a', b', c', d', and e' are numbers that satisfy the following: 0.40≦a'≦0.80, 0≦b'≦0.90, 0≦c'≦0.60, 0≦d'≦0.50, 0≦e'≦0.05, with the proviso that a'+b'+c'+d'=1; (C) an organohydrogensiloxane compound having at least two silicon-bonded hydrogen atoms per molecule; (D) a hydrosilylation catalyst in an amount sufficient to carry out a hydrosilylation reaction of the reactive silicone composition; and (E) a functional inorganic filler in an amount of 400 to 3,000 parts by weight per 100 parts by weight of the total of components (A) to (D). The composition is characterized by being solid at 25°C and having hot-melt properties at temperatures of 200°C or less, and may contain other optional components. Each component of the composition and optional components will be explained below. In the present invention, "average particle size" refers to the average primary particle size of the particles unless otherwise defined.

[0015] In the present invention, unless otherwise specified, "having hot-melt properties" means that the softening point is 50°C or higher, the melt viscosity at 180°C (preferably a melt viscosity of less than 1000 Pa s), and the property of flowing. On the other hand, if the softening point is 200°C or higher, this is above the general use temperature for molding applications, and is therefore defined as "not having hot-melt properties."

[0016] [Component (A)] Component (A) is one of the main components of the present composition and has the average unit formula: (R １ ３ SiO １／２ ) ａ (R ２ ２ SiO ２／２ ) ｂ (R ２ SiO ３／２ )ｃ (SiO ４／２ ) ｄ (R ３ O １／２）ｅ The organopolysiloxane (A) is solid at room temperature but softens as the temperature rises, exhibiting hot-melt properties. １ ３ SiO １ / ２ Siloxane units (hereinafter sometimes referred to as "M units") represented by the formula: １ ３ SiO １ / ２ The MT-type hot-melt organopolysiloxane resin component has at least two alkenyl groups bonded to M units within the molecule, and is characterized in that the values ​​of a and c, which are the proportion of siloxane units (hereinafter sometimes referred to as "T units") represented by the formula: are within a specific range. Note that component (A) may also contain small amounts of other siloxane units such as D units.

[0017] In the formula, each R １ are independently monovalent hydrocarbon groups having 1 to 10 carbon atoms, provided that all R １ At least two of R are alkenyl groups. １ is preferably selected from alkyl groups such as methyl groups, in which a hydrocarbon group may be partially substituted with a halogen atom such as fluorine, aryl groups such as phenyl groups, aralkyl groups such as benzyl groups, and alkenyl groups such as vinyl groups, and is industrially preferably selected from methyl groups, phenyl groups, and alkenyl groups described below. ２ are independently monovalent hydrocarbon groups having 1 to 10 carbon atoms, not including alkenyl groups, and are exemplified by alkyl groups such as methyl, aryl groups such as phenyl, and aralkyl groups such as benzyl, with methyl or phenyl being preferred from an industrial perspective. Furthermore, from the viewpoint of imparting suitable hot melt properties to this component, R ２ It is particularly preferred that at least a portion of each R is an aryl group, more preferably a phenyl group. ３ is a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, and is preferably a hydrogen atom, a methyl group, an ethyl group or a propyl group.

[0018] From the viewpoint of the curability of the present composition, R in component (A) １ At least two of the groups are alkenyl groups, and all silicon-bonded monovalent hydrocarbon groups (i.e., R １ and R ２ R in the range of 10 to 20 mol % relative to １ It is preferable that an alkenyl group is contained therein. When the content of alkenyl groups in component (A) is within the above range, the strength of the cured product is sufficiently improved, and a tough cured product without brittleness is obtained. Examples of alkenyl groups in component (A) include vinyl groups, allyl groups, butenyl groups, pentenyl groups, and hexenyl groups.

[0019] Component (A) is a hot-melt organopolysiloxane resin component containing M units and T units in specific ranges, and specifically, in the formula, a is a group represented by the general formula: R １ ３ SiO １ / ２ is a number that indicates the proportion of siloxane units represented by the formula: R ２ ２ SiO ２ / ２ and is a number that satisfies the relationship 0≦b≦0.05. This is because good hot melt properties can be obtained when b is equal to or less than the upper limit of the above range. Furthermore, c is a number that indicates the proportion of siloxane units represented by the general formula: R ２ SiO ３ / ２ is a number that indicates the proportion of siloxane units represented by the general formula: SiO ４ / ２and is a number that satisfies 0≦d≦0.20, preferably 0≦b≦0.10. This is because when d is equal to or less than the upper limit of the above range, the mechanical strength of the resulting cured product is good. Furthermore, e is a number that satisfies the ratio of the siloxane units represented by the general formula: R ２ O １ / ２ is a number indicating the proportion of units represented by the formula a, b, c, and d, and satisfies the condition 0≦e≦0.05. This is because when e is equal to or less than the upper limit of the above range, the hardness of the resulting cured product at room temperature is good. In the formula, the sum of a, b, c, and d is 1.

[0020] Component (A) itself exhibits hot-melt properties and is preferably non-flowable 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-flowable" means that it does not flow under no load, and refers to a state below the softening point measured by the ring and ball softening point test method for hot-melt adhesives specified in JIS K 6863-1994 "Softening Point Test Method for Hot-Melt Adhesives." In other words, to be non-flowable at 25°C, the softening point must be higher than 25°C.

[0021] Furthermore, as mentioned above, component (A) is a solid at room temperature. Therefore, from the viewpoint of ease of handling when mixed with other components, it is preferable to make it a particulate resin or to dissolve it in other components required for the present composition and use it as a liquid mixture.

[0022] When component (A) is used in the form of fine particles, the particle size is not limited, but the average primary particle size is preferably within the range of 1 to 5,000 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 fine particle (A) component is not limited, and examples include spherical, spindle-shaped, plate-shaped, needle-shaped, and irregular shapes. Spherical or true spherical shapes are preferred because they melt uniformly. In particular, by forming component (A) into true spherical fine particles, the process of producing the present composition by powder mixing or melt-kneading, as described below, can be carried out efficiently.

[0023] When component (A) is microparticulated, the method for producing it is not limited, and known methods can be used. When obtaining microparticulate component (A), a hydrosilylation reaction catalyst, which is component (C) described below, may also be microparticulated together with component (A), and this is preferred.

[0024] Specific methods for microparticulating component (A) include pulverizing component (A), which is solid at room temperature, using a pulverizer, and directly microparticulating component (A) in the presence of a solvent. The pulverizer is not limited, and examples include a roll mill, a ball mill, a jet mill, a turbo mill, and a planetary mill. Alternatively, component (A) may be directly microparticulated in the presence of a solvent, for example, by spraying with a spray dryer, or by microparticulation with a twin-screw kneader or belt dryer. When microparticulating component (A), it is preferable to obtain spherical hot-melt organopolysiloxane resin microparticles by spraying with a spray dryer.

[0025] By using a spray dryer or the like, it is possible to produce component (A) that is spherical and has an average primary particle size of 1 to 500 μm. The heating and drying temperature of the spray dryer must be appropriately set based on the heat resistance, etc., of the organopolysiloxane resin microparticles. In order to prevent secondary aggregation of the organopolysiloxane resin microparticles, it is preferable to control the temperature of the organopolysiloxane resin microparticles below their glass transition temperature. The organopolysiloxane resin microparticles obtained in this manner can be recovered using a cyclone, bag filter, or the like.

[0026] To obtain a uniform component (A), a solvent may be used in the above step as long as 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 monomethyl ether acetate; and ketones such as acetone, methyl ethyl ketone, and methyl isobutyl ketone.

[0027] Component (A) may be used by dissolving it in component (B) or component (C), which will be described later. These components are silicone compounds and are liquid at room temperature, so they exhibit a certain degree of mutual solubility with component (A). Component (A) can be dissolved by adding 10 to 50 parts by mass of component (B) or (C) per 100 parts by mass of component (A). By liquefying component (A), the present composition, which will be described later, can be efficiently produced by powder mixing or melt kneading.

[0028] [Component (B)] Component (B) is one of the characteristic components of the present invention. It is an organosiloxane compound containing at least a certain amount of alkenyl groups in the molecule, and functions as a crosslink density adjuster. Specifically, when used in combination with the above-mentioned component (A), it increases the crosslink density of the cured product of this composition, improving its mechanical strength, and also reduces the melt viscosity of the hot-melt curable silicone composition obtained by the specific molecular structure shown below, improving handling, workability, and gap filling properties.

[0029] Specifically, the component (B) is (R １ ３ SiO １／２ ) ａ´ (R ２ ２ SiO ２／２ ) ｂ´ (R ２ SiO ３／２ ) ｃ´ (SiO ４／２ ) ｄ´ (R ３ O１／２）ｅ´ (In the formula, each R １ are independently monovalent hydrocarbon groups having 1 to 10 carbon atoms, provided that all R １ At least two of R are alkenyl groups, and each R ２ are independently monovalent hydrocarbon groups having 1 to 10 carbon atoms, not including alkenyl groups; each R ３ is a hydrogen atom or an alkyl group having 1 to 10 carbon atoms) in one molecule, and the alkenyl group is 10 mass % or more of the organosiloxane compound.

[0030] In the formula, each R １ , R ２ , R ３ are independently the same groups as defined above, and similar groups are exemplified. a', b', c', d', and e' are numbers that satisfy the following: 0.40≦a'≦0.80, 0≦b'≦0.90, 0≦c'≦0.60, 0≦d'≦0.50, 0≦e'≦0.05, with the proviso that a'+b'+c'+d'=1.

[0031] From the viewpoint of improving the mechanical strength of the cured product obtained by curing the present composition, R １ At least two of these groups are alkenyl groups, and 10% by mass or more, preferably 10 to 40% by mass of R １ It is preferable that an alkenyl group is contained therein. When the content of alkenyl groups in component (B) is within the above range, the strength of the cured product is sufficiently improved, and a tough cured product without brittleness is obtained. Examples of alkenyl groups in component (B) include vinyl groups, allyl groups, butenyl groups, pentenyl groups, and hexenyl groups.

[0032] In the formula, a′ represents the general formula: R １ ３ SiO １ / ２ is a number that indicates the proportion of siloxane units represented by the formula: R ２ ２ SiO２ / ２ and is a number that satisfies the relationship 0≦b′≦0.50. This is because when b′ is equal to or less than the upper limit of the above range, the effect of improving the strength of the resulting cured product is sufficient. ２ SiO ３ / ２ is a number that indicates the proportion of siloxane units represented by the general formula: SiO ４ / ２ and is a number that satisfies the relationship 0≦d′≦0.50. This is because when d′ is equal to or less than the upper limit of the above range, the mechanical strength of the resulting cured product is good. Furthermore, e′ is a number that indicates the proportion of siloxane units represented by the general formula: R ２ O １ / ２ is a number indicating the proportion of units represented by the formula a', b', c', and d', and is a number satisfying the condition 0≦e'≦0.05. This is because when e' is equal to or less than the upper limit of the above range, the hardness of the resulting cured product at room temperature is good. In the formula, the sum of a', b', c', and d' is 1.

[0033] Because of the above structure, component (B) is liquid at room temperature, and it is particularly preferred that the viscosity at 25°C is 10,000 mPa·s or less.

[0034] [Component (C)] Component (C) is a crosslinking agent for the composition, and is an organohydrogensiloxane compound having at least two silicon-bonded hydrogen atoms per molecule. There are no particular restrictions on its structure, and it may be linear, branched, cyclic, or resinous. However, from the viewpoint of excellent curing properties of the resulting composition, it is preferable that the component (C) has an HR group at the end. ２ SiO １／２ Hydrogen diorganosiloxy units (M Ｈ Preferably, the organohydrogenpolysiloxane has a unit (R) independently representing a monovalent organic group.

[0035] Preferably, component (C) is an organopolysiloxane having two or more silicon-bonded hydrogen atoms per molecule, with phenyl groups accounting for 20 to 70 mol % of all silicon-bonded organic groups. Component (C) has two or more silicon-bonded hydrogen atoms per molecule, which ensures sufficient crosslinking for curing and good hardness of the resulting cured product. Furthermore, when the phenyl group content is at or above the lower limit of the above range, the resulting cured product has good mechanical strength at high temperatures, while when it is at or below the upper limit of the above range, the resulting cured product also has good mechanical strength.

[0036] Examples of silicon-bonded organic groups in component (C) 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 aralkyl groups such as benzyl and phenethyl groups, and other monovalent hydrocarbon groups that do not contain aliphatic unsaturated bonds. Of these, phenyl and alkyl groups having 1 to 6 carbon atoms are preferred.

[0037] Examples of such component (C) include: (C-1) a compound represented by the general formula: HR ４ ２ SiO(R ４ ２ SiO) ｎ SI ４ ２ and (C-2) a linear organopolysiloxane represented by the average unit formula: (R ４ SiO ３／２ ) ｐ (R ４ ２ SiO ２／２ ) ｑ (HR ４ ２ SiO １／２ ) ｒ (SiO ４／２ ) ｓ (XO １／２ ) ｔ It is preferable to use a combination of these two types of component (B).

[0038] In the formula, R ４are the same or different and are phenyl groups or alkyl groups having 1 to 6 carbon atoms. ４ Examples of the alkyl group of R include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a cyclopentyl group, and a cyclohexyl group. ４ The content of phenyl groups is in the range of 30 to 70 mol %.

[0039] In the formula, n is an integer in the range of 5 to 1,000. 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, q / p is a number in the range of 0 to 10, r / p is a number in the range of 0.1 to 5, s / (p+q+r+s) is a number in the range of 0 to 0.3, and t / (p+q+r+s) is a number in the range of 0 to 0.4.

[0040] In this type of component (C), it is preferable to use a combination of components (C-1) and (C-2) from the viewpoint of easy control of the curing rate of the composition and the crosslink density of the resulting cured product. The preferred ratio of the two components is (C-1):(C-2) = 0.05-0.6:0.4-0.95, preferably 0.05-0.5:0.5-0.95, more preferably 0.05-0.4:0.5-0.95, per alkenyl group in the entire composition. [Component (D)] Component (D) is a hydrosilylation catalyst that initiates the curing reaction of the present composition. Examples include platinum-based catalysts, rhodium-based catalysts, and palladium-based catalysts, with platinum-based catalysts being preferred due to their ability to significantly accelerate the curing of the present composition. Examples of the platinum catalyst include platinum fine powder, chloroplatinic acid, an alcohol solution of chloroplatinic acid, a platinum-alkenylsiloxane complex, a platinum-olefin complex, a platinum-carbonyl complex, and catalysts in which these platinum catalysts are dispersed or encapsulated in a thermoplastic resin such as a silicone resin, a polycarbonate resin, or an acrylic resin, with platinum-alkenylsiloxane complexes being particularly preferred. Examples of the alkenylsiloxane include 1,3-divinyl-1,1,3,3-tetramethyldisiloxane, 1,3,5,7-tetramethyl-1,3,5,7-tetravinylcyclotetrasiloxane, alkenylsiloxanes in which some of the methyl groups of these alkenylsiloxanes have been substituted with ethyl groups, phenyl groups, or the like, and alkenylsiloxanes in which the vinyl groups of these alkenylsiloxanes have been substituted with allyl groups, hexenyl groups, or the like. In particular, 1,3-divinyl-1,1,3,3-tetramethyldisiloxane is preferred because of the good stability of this platinum-alkenylsiloxane complex. Note that non-platinum metal catalysts such as iron, ruthenium, and iron / cobalt may also be used as catalysts to promote the hydrosilylation reaction.

[0041] In addition, from the viewpoint of improving the stability, handling, and pot life of the composition during production, component (D) preferably contains platinum-based catalyst-containing thermoplastic resin microparticles, which may be either microparticles in which the platinum-based catalyst is dissolved or dispersed in the thermoplastic resin, or microcapsule microparticles in which the platinum-based catalyst is contained as a core in the shell of the thermoplastic resin. Examples of platinum-based catalysts include platinum black, platinum-supported carbon micropowder, platinum-supported silica micropowder, chloroplatinic acid, alcohol-modified chloroplatinic acid, platinum olefin complex, and platinum alkenylsiloxane complex. In addition, the thermoplastic resin is not particularly limited as long as it does not substantially allow the platinum-based catalyst to penetrate at least during production and storage of the composition and does not substantially dissolve in the organopolysiloxane, the main component of the composition. However, the softening point or glass transition point of this thermoplastic resin is preferably 80°C or higher, more preferably 120°C or higher. Specifically, silicone resins, polysilane resins, epoxy resins, acrylic resins, and methylcellulose polycarbonate resins are preferably used. The softening point is the temperature at which the resin begins to flow under its own weight or its own surface tension. It can be measured by observing pulverized particles under a microscope while increasing the temperature at a constant rate. The glass transition point can also be measured using a differential scanning calorimeter (DSC). In the present invention, either the softening point or the glass transition point is preferably 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 risk that the platinum component will begin to leach out during the process of homogenizing the composition, as described below. The average particle size of the platinum-based catalyst-containing thermoplastic microparticles is not limited, but is preferably within the range of 0.1 to 500 μm, and more preferably within the range of 0.3 to 100 μm. This is because it is difficult to prepare platinum-based catalyst-containing thermoplastic resin microparticles with an average particle size below the lower limit of the range, while dispersibility in the curable silicone resin composition is reduced if the average particle size exceeds the upper limit of the range.

[0042] The method for preparing such platinum-based catalyst-containing thermoplastic resin microparticles is not limited, and examples include conventionally known chemical methods such as interfacial polymerization and in-situ polymerization, as well as physical and mechanical methods such as coacervation and submerged drying. Submerged drying and vapor-phase drying are particularly desirable because they allow for the relatively easy production of microcapsule microparticles with a narrow particle size distribution. While the microparticles obtained by these methods can be used as is, it is desirable to wash them with an appropriate 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 dissolves 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 catalyst to the thermoplastic resin varies significantly depending on the method for producing the granules, so no particular limitation can be placed on it. However, it is preferable for the platinum-based catalyst content to be 0.01% by mass or greater relative to the thermoplastic resin. This is because if the platinum catalyst content is less than 0.01% by mass, the physical properties of the cured product will be impaired unless the composition contains a large amount of platinum catalyst-containing thermoplastic resin particles.

[0043] The amount of the hydrosilylation catalyst added is a catalytic amount, and is preferably an amount that results in a metal atom concentration, by mass, of 0.01 to 500 ppm, 0.01 to 100 ppm, or 0.01 to 50 ppm, relative to the entire composition.

[0044] [Component (E)] Component (E) is a functional inorganic filler that can provide a curable silicone composition that cures to give a cured product with excellent hardness and toughness from room temperature to high temperatures. In the present invention, from the viewpoint of achieving a low average linear expansion coefficient and mechanical strength (particularly, bending strength, etc.) in the resulting cured product, the component (E) is contained in an amount ranging from 400 to 3,000 parts by mass, preferably from 500 to 3,000 parts by mass, or even from 800 to 3,000 parts by mass, per 100 parts by mass of components (A) to (D). Furthermore, from the viewpoint of achieving a low average linear expansion coefficient in the cured product, the content of component (E) 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.

[0045] In order to achieve the above blending amounts and a low average linear expansion coefficient for the resulting cured product, it is preferable that component (E) be treated with a specific surface treatment agent, particularly a surface treatment agent in an amount of 0.1 to 2.0 mass%, 0.1 to 1.0 mass%, or 0.2 to 0.8 mass%, relative to the total mass of component (E). Treating component (E) with the above treatment amount of surface treatment agent has the advantage of allowing a high volume percentage of component (E) to be stably blended into the composition. Furthermore, any surface treatment method can be used, and any desired method can be used, such as a homogeneous mixing method using mechanical force (dry method) or a wet mixing method using a solvent.

[0046] Examples of these surface treatment agents include fluorine compounds such as methylhydrogenpolysiloxane, silicone resin, metal soap, silane coupling agent, perfluoroalkylsilane, and perfluoroalkyl phosphate ester salt, among others, but the silicone surface treatment agents described below are particularly preferred. Note that, if a silane surface treatment agent such as methyltrimethoxysilane or phenyltrimethoxysilane is selected as the surface treatment agent for component (E), the hot melt properties of the entire composition may be impaired, and component (E) may not be stably blended up to the above-mentioned volume % content. Furthermore, if an alkyltrialkoxysilane having a long-chain alkyl group such as an octyl group is selected as the surface treatment agent, the hot melt properties of the composition and the blending stability of component (E) tend to be maintained, but the strength of the cured product obtained by curing the composition of the present invention may be reduced, which may cause cracks or molding defects.

[0047] Here, examples of the organosilicon compound that is the surface treatment agent include low molecular weight organosilicon compounds such as silane, silazane, siloxane, or the like, and organosilicon polymers or oligomers such as polysiloxane, polycarbosiloxane, or the like.Preferred examples of silanes are so-called silane coupling agents.Representative examples of such silane coupling agents include alkyltrialkoxysilanes (methyltrimethoxysilane, vinyltrimethoxysilane, hexyltrimethoxysilane, octyltrimethoxysilane, decyltrimethoxysilane, or the like), and organofunctional group-containing trialkoxysilanes (glycidoxypropyltrimethoxysilane, epoxycyclohexylethyltrimethoxysilane, methacryloxypropyltrimethoxysilane, aminopropyltrimethoxysilane, or the like). Preferred siloxanes and polysiloxanes include hexamethyldisiloxane, 1,3-dihexyl-tetramethyldisiloxane, trialkoxysilyl single-terminated polydimethylsiloxane, trialkoxysilyl single-terminated dimethylvinyl single-terminated polydimethylsiloxane, trialkoxysilyl single-terminated organofunctional group single-terminated polydimethylsiloxane, trialkoxysilyl doubly-terminated polydimethylsiloxane, organofunctional group doubly-terminated polydimethylsiloxane, or the like. When siloxanes are used, the number n of siloxane bonds preferably ranges from 2 to 150. Examples of preferred silazanes include hexamethyldisilazane, 1,3-dihexyl-tetramethyldisilazane, or the like. Examples of preferred polycarbosiloxanes are polymers having Si-C-C-Si bonds within the polymer backbone.

[0048] Particularly preferred examples of silicone-based surface treatment agents include silicone-based surface treatment agents having at least one polysiloxane structure and a hydrolyzable silyl group in the molecule. Most preferred is the use of a silicone-based surface treatment agent having at least one polysiloxane structure and a hydrolyzable silyl group in the molecule, represented by the structural formula (1): R' ｎ (RO) ３－ｎ SiO—(R′ ２SiO) ｍ -SiR' ｎ (RO) ３－ｎ or structural formula (2): R' ３ SiO—(R′ ２ SiO) ｍ -SiR' ｎ (RO) ３－ｎ Examples include organopolysiloxanes having a linear alkoxysilyl end group represented by the formula: In this formula, R is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms (= methyl, ethyl, or propyl), and 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 alkenyl group having 2 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, examples of which are the same as those described above. n is a number ranging from 0 to 2, and m is a number ranging from 2 to 200, and may also be a number ranging from 2 to 150.

[0049] Component (E) is preferably at least one inorganic filler that does not have a softening point between room temperature and 200°C. It may also be a component that improves the handling and workability of the composition and imparts mechanical and other properties to the cured product of the composition. Examples of inorganic fillers that constitute component (E) include reinforcing fillers, white pigments, thermally conductive fillers, electrically conductive fillers, phosphors, and mixtures of at least two of these. To achieve a high volume percent loading, it is preferable to contain a reinforcing filler with an average particle size of 10.0 μm or more. Examples of organic fillers that can be used in combination with component (E) 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, fibrous, spindle-shaped, flat, acicular, plate-shaped, amorphous, etc.

[0050] Preferably, 50% or more of the total component (E) is an inorganic filler having an average particle size of 10.0 μm or more. In particular, spherical inorganic fillers having an average particle size of 10.0 μm or more are preferred because they provide a small rate of change in hardness and storage modulus from room temperature to high temperatures. Such inorganic fillers can be blended or filled in relatively large amounts relative to components (A) to (D), and offer practical benefits such as improving the mechanical strength of the cured product and reducing the average linear expansion coefficient. On the other hand, inorganic or organic fillers having an average particle size of 5 μm or less may be blended in order to impart or improve the light reflectance, electrical conductivity, thermal conductivity, fluorescent properties, stress relaxation properties, etc., of the composition of the present invention.

[0051] When the present composition is used as a sealant, protective agent, adhesive, light reflector, or the like, it is preferable to incorporate a reinforcing filler as component (E) to impart mechanical strength to the cured product and improve protective or adhesive properties. Examples of 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, 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 an organoalkoxysilane such as methyltrimethoxysilane; an organohalosilane such as trimethylchlorosilane; an organosilazane such as hexamethyldisilazane; or a siloxane oligomer such as an α,ω-silanol group-blocked dimethylsiloxane oligomer, an α,ω-silanol group-blocked methylphenylsiloxane oligomer, or an α,ω-silanol group-blocked methylvinylsiloxane oligomer. Furthermore, as the reinforcing filler, 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 fiber, calcium carbonate whiskers, titanium oxide whiskers, and ceramic fiber; and fibrous fillers such as aramid fiber, polyimide fiber, and polyparaphenylene benzobisoxazole fiber may be used.Furthermore, plate-like fillers or granular fillers such as talc, kaolin clay, calcium carbonate, zinc oxide, calcium silicate hydrate, mica, glass flakes, glass powder, magnesium carbonate, silica, titanium oxide, 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, and pulverized products of the above-mentioned fibrous fillers may also be used.

[0052] In particular, from the viewpoint of imparting hardness to the present composition at room temperature to high temperatures in the cured product, it is preferred that 50 mass % or more of the total component (E) be spherical silica or aluminum oxide (alumina) having an average particle size of 10.0 μm or more.

[0053] Component (E) may contain silicone microparticles to improve or, if desired, adjust stress relaxation properties, etc. Examples of silicone microparticles include non-reactive silicone resin microparticles and silicone elastomer microparticles, with silicone elastomer microparticles being preferred from the standpoint of improving flexibility or stress relaxation properties.

[0054] Silicone elastomer microparticles are crosslinked products of linear diorganopolysiloxanes primarily composed of diorganosiloxy units (D units). Silicone elastomer microparticles can be prepared by crosslinking diorganopolysiloxanes through hydrosilylation reactions or silanol group condensation reactions. Among these, they are preferably obtained by crosslinking an organohydrogenpolysiloxane having silicon-bonded hydrogen atoms in the side chain or at the end with a diorganopolysiloxane having unsaturated hydrocarbon groups such as alkenyl groups in the side chain or at the end in the presence of a hydrosilylation catalyst. Silicone elastomer microparticles can take various shapes, such as spherical, flat, and irregular, but spherical is preferred from the perspective of dispersibility, and true spheres are even more preferred. Examples of commercially available silicone elastomer microparticles include the "Trefil E Series" and "EP Powder Series" manufactured by Dow Corning Toray Co., Ltd., and the "KMP Series" manufactured by Shin-Etsu Chemical Co., Ltd. The silicone elastomer particles may be surface-treated. The elastomer particles may be made of acrylonitrile butadiene rubber, isoprene, styrene butadiene rubber, ethylene propylene rubber, or the like.

[0055] Furthermore, when the present composition is used as a wavelength conversion material for LEDs, a phosphor may be blended as component (E) to convert the wavelength of light emitted from an optical semiconductor element. The phosphor is not particularly limited, and examples thereof include yellow-, red-, green-, and blue-emitting phosphors composed of oxide-based phosphors, oxynitride-based phosphors, nitride-based phosphors, sulfide-based phosphors, oxysulfide-based phosphors, and the like, which are widely used in light-emitting diodes (LEDs). Examples of oxide-based phosphors include yttrium-, aluminum-, and garnet-based YAG-based green- to yellow-emitting phosphors containing cerium ions; terbium-, aluminum-, and garnet-based TAG-based yellow-emitting phosphors containing cerium ions; and silicate-based green- to yellow-emitting phosphors containing cerium and europium ions. Examples of oxynitride-based phosphors include silicon-, aluminum-, oxygen-, and nitrogen-based sialon-based red- to green-emitting phosphors containing europium ions. Examples of nitride-based phosphors include calcium, strontium, aluminum, silicon, and nitrogen-based red-emitting phosphors containing europium ions. Examples of sulfide-based phosphors include ZnS-based green-emitting phosphors containing copper ions or aluminum ions. Examples of oxysulfide-based phosphors include YS-based phosphors containing europium ions. ２ O ２ S-based red-emitting phosphors are exemplified. In the present composition, two or more of these phosphors may be used in combination.

[0056] Furthermore, the present composition may contain a thermally conductive filler or an electrically conductive filler to impart thermal conductivity or electrical conductivity to the cured product. Examples of such thermally conductive fillers or electrically conductive fillers include fine metal powders such as gold, silver, nickel, copper, aluminum, tin, lead, zinc, bismuth, and antimony; fine powders obtained by vapor-depositing or plating metals such as gold, silver, nickel, and copper on the surface of fine powders such as ceramic, glass, quartz, and organic resin; 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 present composition, metal oxide powders or metal nitride powders are preferred, and aluminum oxide powder, zinc oxide powder, and aluminum nitride powder are particularly preferred.

[0057] Furthermore, the composition may contain a colorant to impart color to the cured product. Examples of such colorants include black titanium oxide, pitch (the residue obtained by distilling tar obtained by dry distillation of organic substances such as petroleum, coal, and wood), carbon black, acetylene black, and red iron oxide. Acetylene black is preferably used when the content of metal impurities is to be reduced. Black dyes such as anthraquinone dyes (sometimes written as "anthraquinone"), azine dyes, azo dyes, disazo dyes, and chromium complex dyes may also be contained. When used in combination with yellow dyes such as methine dyes, disazo dyes, azocobalt complex dyes, and azochromium complex dyes, the color can be closer to that of a black pigment.

[0058] Furthermore, the composition may optionally contain a thermally expandable filler. The incorporation of a thermally expandable filler can improve the volumetric expansion coefficient of the composition of the present invention and may reduce uneven dispersion of the composition. Preferably, the thermally expandable filler has a core-shell structure, containing a volatile expanding agent within the shell of the core-shell structure. Here, a volatile expanding agent refers to a substance that generates gas at temperatures below the softening point of the shell. The thermally expandable filler has a structure in which a volatile expanding agent is encapsulated as a core agent within a shell with gas barrier properties. Therefore, the volatile expanding agent becomes gaseous upon exposure to heat, and the shell softens and expands. Examples of such components are exemplified in, for example, JP 2020-084094 A, and are available from Matsumoto Yushi Seiyaku Co., Ltd., such as FN-100SSD and FN-80GSD.

[0059] When the cured product obtained by curing the composition is used in magnetic components such as dust magnetic needles, coils, and electromagnetic wave shielding materials, magnetic particles may be included as component (C). Such magnetic particles contain one or more elements selected from the group consisting of Fe, Cr, Co, Ni, Ag, and Mn. In particular, soft magnetic particles may include magnetic particles made of iron (Fe), Fe—Si alloys, Fe—Al alloys, Fe—Ni alloys, Fe—Co alloys, Fe—Si—Al alloys, Fe—Si—Cr alloys, Fe—Cr alloys, carbonyl iron, stainless steel, etc. From the standpoint of availability, magnetic particles made of carbonyl iron may also be used. These magnetic particles may be surface-treated with a silane compound, titanate compound, aluminate compound, or a partial hydrolyzate thereof, as with the inorganic fillers described above, which may prevent deactivation of the curing catalyst or crosslinking agent and improve storage stability. In addition, these magnetic particles may have a surface coating layer containing a siloxane polymer, for example, by the method described in JP-A-2021-036013.

[0060] The present composition may also contain other optional components, such as (F) a cure retarder, (G) an adhesion promoter, and (H) an organic wax, as long as the object of the present invention is not impaired.

[0061] [Component (F)] Component (F) is a cure retarder that effectively suppresses side reactions, particularly when the present composition is cured by a hydrosilylation reaction, and may further improve the storage stability and usable life of the composition when heated and melted.

[0062] Usable cure retarders are not particularly limited in structure or type, and can be selected from known hydrosilylation reaction inhibitors. Examples include alkyne alcohols such as 2-methyl-3-butyn-2-ol, 3,5-dimethyl-1-hexyn-3-ol, 2-phenyl-3-butyn-2-ol, and 1-ethynyl-1-cyclohexanol; eneyne compounds such as 3-methyl-3-penten-1-yne and 3,5-dimethyl-3-hexen-1-yne; alkenyl group-containing low-molecular-weight siloxanes such as tetramethyltetravinylcyclotetrasiloxane and tetramethyltetrahexenylcyclotetrasiloxane; and alkynyloxysilanes such as methyl-tris(1,1-dimethyl-2-propynyloxy)silane and vinyl-tris(1,1-dimethylpropynyloxy)silane.

[0063] It is particularly preferable to use a compound with a boiling point of 200°C or higher at atmospheric pressure as component (F). From the standpoint of compositional homogenization, the composition of the present invention can be produced through a process involving heating, such as melt-kneading of the composition. However, if a compound with a low boiling point is used as a delayed curing agent, some or all of the cure retarder may volatilize during the melt-kneading step, and the desired cure retardation effect in the final curable silicone composition may not be achieved. Note that methyl-tris(1,1-dimethyl-2-propynyloxy)silane has a boiling point of 245°C at atmospheric pressure and is an example of a suitable component (F).

[0064] The amount of component (F) used is not limited, but is preferably within the range of 1 to 10,000 ppm by mass relative to the total composition.

[0065] [Component (G)] Component (F) is an adhesion promoter, and is exemplified by an organosilicon compound containing at least one alkoxy group bonded to a silicon atom per molecule. Examples of this alkoxy group include methoxy, ethoxy, propoxy, butoxy, and methoxyethoxy groups, with methoxy being particularly preferred. Examples of groups bonded to silicon atoms in the organosilicon compound other than the alkoxy group include halogen-substituted or unsubstituted monovalent hydrocarbon groups such as alkyl, alkenyl, aryl, aralkyl, and halogenated alkyl groups; glycidoxyalkyl groups such as 3-glycidoxypropyl and 4-glycidoxybutyl; epoxycyclohexylalkyl 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-containing monovalent organic groups such as 3-methacryloxypropyl; and a hydrogen atom. The organosilicon compound preferably has a group capable of reacting with an alkenyl group or a silicon-bonded hydrogen atom in the composition, and more specifically, a silicon-bonded hydrogen atom or an alkenyl group. Furthermore, since this provides good adhesion to various substrates, the organosilicon compound preferably has at least one epoxy-containing monovalent organic group per molecule. Examples of such organosilicon compounds include organosilane compounds, organosiloxane oligomers, and alkyl silicates. Examples of the molecular structure of the organosiloxane oligomer or alkyl silicate include linear, partially branched linear, branched, cyclic, and network structures, with linear, branched, and network structures being particularly preferred.Examples of organosilicon compounds include silane compounds such as 3-glycidoxypropyltrimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, and 3-methacryloxypropyltrimethoxysilane; siloxane compounds having in one molecule at least one silicon-bonded alkenyl group or one silicon-bonded hydrogen atom, and one silicon-bonded alkoxy group; a mixture of a silane compound or siloxane compound having in one molecule at least one silicon-bonded alkoxy group and a siloxane compound having in one molecule at least one silicon-bonded hydroxy group and one silicon-bonded alkenyl group; a reaction mixture of an amino-containing organoalkoxysilane and an epoxy-containing organoalkoxysilane; an organic compound having in one molecule at least two alkoxysilyl groups and containing a bond other than a silicon-oxygen bond between the silyl groups; and compounds represented by the general formula: R. ａ ｎ Si(OR ｂ ) ４－ｎ (In the formula, R ａ is a monovalent epoxy group-containing organic group, and R ｂ is an alkyl group having 1 to 6 carbon atoms or a hydrogen atom. n is a number ranging from 1 to 3), or a partial hydrolysis condensate thereof; a reaction mixture of a vinyl group-containing siloxane oligomer (including those with a linear or cyclic structure) with an epoxy group-containing trialkoxysilane; methyl polysilicate, ethyl polysilicate, and epoxy group-containing ethyl polysilicate. This adhesion promoter is preferably a low-viscosity liquid, and although there are no limitations on its viscosity, it is preferably in the range of 1 to 500 mPa·s at 25°C. Furthermore, there are no limitations on the content of this adhesion promoter, but it is preferably in the range of 0.01 to 10 parts by mass per 100 parts by mass of the total composition.

[0066] In the present invention, a particularly suitable adhesion promoter is a reaction mixture of an amino-containing organoalkoxysilane and an epoxy-containing organoalkoxysilane. This component improves the initial adhesion of the curable silicone composition to various substrates that it comes into contact with during curing, and in particular the low-temperature adhesion of the composition to unwashed substrates. Such reaction mixtures are disclosed in Japanese Patent Publication No. 52-8854 and Japanese Patent Laid-Open Publication No. 10-195085.

[0067] Examples of alkoxysilanes having an amino group-containing organic group that constitute such a component 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.

[0068] Examples of epoxy group-containing organoalkoxysilanes include 3-glycidoxyprolyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, and 2-(3,4-epoxycyclohexyl)ethylmethyldimethoxysilane.

[0069] The molar ratio of these alkoxysilanes having an amino group-containing organic group to those having an epoxy group-containing organic group is preferably within the range of (1:1.5) to (1:5), and particularly preferably within the range of (1:2) to (1:4). This component can be easily synthesized by mixing the above-mentioned alkoxysilanes having an amino group-containing organic group and alkoxysilanes having an epoxy group-containing organic group and reacting them at room temperature or under heat.

[0070] In particular, in the curable hot-melt silicone composition of the present invention, when an alkoxysilane having an amino group-containing organic group is reacted with an alkoxysilane having an epoxy group-containing organic group by the method described in JP-A-10-195085, a compound having the general formula: {In the formula, R 1 is an alkyl group, an alkenyl group, or an alkoxy group, and R 2 are the same or different general formula: (In the formula, R 4 is an alkylene group or an alkyleneoxyalkylene group, and R 5 is a monovalent hydrocarbon group, and R 6 is an alkyl group, and R 7 is an alkylene group, and R 8 is an alkyl group, an alkenyl group, or an acyl group, and a is 0, 1, or 2; 3 are the same or different hydrogen atoms or alkyl groups.} Examples of such carbasilatrane derivatives include carbasilatrane derivatives having a silicon-bonded alkoxy group or a silicon-bonded alkenyl group in one molecule, as shown in the following structure: (wherein Rc is a group selected from a methoxy group, an ethoxy group, a vinyl group, an allyl group, and a hexenyl group.)

[0071] In the present invention, a silatrane derivative represented by the following structural formula may also be used as an adhesion promoter. R in the formula 1 are the same or different hydrogen atoms or alkyl groups, and in particular, R 1 is preferably a hydrogen atom or a methyl group. 2 represents a hydrogen atom, an alkyl group, or a group represented by the general formula: -R 4 -Si(OR 5 ) x R 6 (3-x) are the same or different groups selected from the group consisting of alkoxysilyl group-containing organic groups represented by the formula:2 At least one of R is an alkoxysilyl group-containing organic group. 2 Examples of the alkyl group of R include a methyl group. 2 In the alkoxysilyl group-containing organic group, R 4 is a divalent organic group, and examples thereof include an alkylene group or an alkyleneoxyalkylene group, and particularly preferably an ethylene group, a propylene group, a butylene group, a methyleneoxypropylene group, or a methyleneoxypentylene group. 5 is an alkyl group having 1 to 10 carbon atoms, and is preferably a methyl group or an ethyl group. 6 is a substituted or unsubstituted monovalent hydrocarbon group, preferably a methyl group, and x in the formula is 1, 2, or 3, preferably 3.

[0072] Such an R 2 Examples of the alkoxysilyl group-containing organic group include the following groups: -(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(OCH３ ) 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

[0073] R in the above formula 3 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, oxiranylalkyl groups, and acyloxyalkyl groups; R 3 Examples of the monovalent hydrocarbon group of R include alkyl groups such as methyl groups. 3 Examples of the alkoxy group of R include a methoxy group, an ethoxy group, and a propoxy group. 3 An example of the glycidoxyalkyl group of R is a 3-glycidoxypropyl group. 3 Examples of the oxiranylalkyl group of R include a 4-oxiranylbutyl group and an 8-oxiranyloctyl group. 3 Examples of the acyloxyalkyl group include an acetoxypropyl group and a 3-methacryloxypropyl group. 3 is preferably an alkyl group, an alkenyl group, or an alkoxy group, more preferably an alkyl group or an alkenyl group, and particularly preferably a group selected from a methyl group, a vinyl group, an allyl group, and a hexenyl group.

[0074] The amount of component (G) used is not particularly limited, but from the viewpoint of improving adhesion to poorly adhesive substrates, it is preferably in the range of 0.1 to 1.0 mass % of the entire composition, and more preferably in the range of 0.2 to 1.0 mass %. Furthermore, the amount of component (G) blended may be in the range of 5 to 50 mass parts, or may be in the range of 5 to 40 mass parts, per 100 mass parts of the total of components (A) and (B).

[0075] [Component (H)] Component (H) is a hot-melt fine particle other than component (A). Specifically, it is an organic wax having a melting point in the range of 30 to 160°C. Component (H) can be one or more selected from various hot-melt synthetic resins, waxes, fatty acid metal salts, etc. The wax component exhibits low kinematic viscosity at high temperatures (150°C) and forms a melt with excellent fluidity. Furthermore, when used in combination with components (A) to (C), the wax component in the melt of the present composition rapidly spreads throughout the composition at high temperatures, thereby reducing the viscosity of the substrate surface to which the molten composition is applied and the entire composition, rapidly reducing the surface friction between the substrate and the molten composition, and significantly increasing the fluidity of the entire composition. Therefore, adding only a small amount of component (H) relative to the total amount of the other components can significantly improve the viscosity and fluidity of the molten composition.

[0076] The wax component may be a petroleum wax such as paraffin, a natural wax such as carnauba wax, or a synthetic wax such as Montan acid ester wax, as long as it satisfies the above-mentioned conditions of dropping point and kinematic viscosity when melted. However, from the viewpoint of the technical effects of the present invention, a hot-melt component comprising a fatty acid metal salt or a fatty acid ester of an erythritol derivative is preferred, with metal salts of higher fatty acids such as stearic acid, palmitic acid, oleic acid, and isononanoic acid, as well as pentaerythritol tetrastearate, dipentaerythritol adipate stearate, glycerin tri-18-hydroxystearate, and pentaerythritol frustearate being particularly preferred. The type of fatty acid metal salt is not particularly limited, but suitable examples include alkali metal salts such as lithium, sodium, and potassium; alkaline earth metal salts such as magnesium, calcium, and barium; and zinc salts.

[0077] Particularly preferred wax components are fatty acid metal salts or erythritol derivatives with a free fatty acid content of 5.0% or less, and particularly preferably 4.0% or less, and 0.05 to 3.5%. Examples of such components include at least one metal stearate. Specifically, it is most preferred to use a hot-melt component with a melting point of 150°C or less, selected from calcium stearate (melting point 150°C), zinc stearate (melting point 120°C), magnesium stearate (melting point 130°C), pentaerythritol tetrastearate (melting point 60-70°C), pentaerythritol adipate stearate (melting point 55-61°C), pentaerythritol full stearate (melting point 62-67°C), etc.

[0078] The amount of wax component used, based on 100 parts by mass of the entire composition, is in the range of 0.01 to 5.0 parts by mass, or alternatively 0.01 to 3.5 parts by mass, or 0.01 to 3.0 parts by mass. If the amount of wax component used exceeds the upper limit, the adhesiveness and mechanical strength of the cured product obtained from the granular curable silicone composition of the present invention may be insufficient. If the amount used is less than the lower limit, sufficient fluidity may not be achieved when heated and melted.

[0079] Furthermore, the present composition may contain other optional components, as long as they do not impair the object of the present invention, such as heat resistance agents such as iron oxide (red iron oxide), cerium oxide, cerium dimethylsilanolate, fatty acid cerium salts, cerium hydroxide, and zirconium compounds; dyes, pigments other than white, flame retardants, heat retardants such as aluminum hydroxide, magnesium hydroxide, zinc borate, zinc molybdate, and phosphazene; ion scavengers and pH adjusters such as hydrotalcite, bismuth oxide, and yttrium oxide; flame retardants such as magnesium chloride, zinc borate, zinc molybdate, phosphazene, etc.; antioxidants such as hindered phenol compounds, hindered amine compounds, thioether compounds, etc.; soft magnetic particles such as pure iron, silicon steel, iron-cobalt alloys, iron-nickel alloys, iron-chromium alloys, iron-aluminum alloys, carbonyl iron, stainless steel, or composite materials containing one or more of these; inorganic flame retardants (for example, hydrated metal compounds such as aluminum hydroxide), halogen-based flame retardants, phosphorus-based flame retardants, organic metal salt-based flame retardants, Silicone oil, silicone rubber, polyisoprene, polybutadienes such as 1,2-polybutadiene and 1,4-polybutadiene, styrene-butadiene rubber, acrylonitrile-butadiene rubber, carboxyl group-terminated butadiene acrylonitrile rubber, thermoplastic elastomers such as polychloroprene, poly(oxypropylene), poly(oxytetramethylene) glycol, polyolefin glycol and 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 ３ , also 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), silicon carbide (SiC), barium calcium zirconate titanate (also known as BCTZ), polyvinylidene fluoride or other dielectric ceramics; metal salt stabilizers such as copper chloride, cupric 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; ultraviolet absorbers, weathering agents, and light stabilizers such as benzophenones, salicylates, and benzotriazoles.

[0080] [Use of the present composition] The present composition can be in any of the forms of granules, pellets, and sheets depending on the manufacturing process. Here, the granular or granular composition can be further tableted by a known method to be used in the form of a pellet-shaped product or a tablet-shaped product.

[0081] Here, "pellets" and "tablets" are general names or common names for granular tablet-molded products made from a resin composition. The shape of the pellets / tablets is not limited, but is usually spherical, oval-spherical, or cylindrical. The size of the pellets is also not limited, but may have, for example, an average particle diameter or equivalent circle diameter of 500 μm or more, and may have an average particle diameter or equivalent circle diameter of 1 mm or more.

[0082] [Method for Producing Curable Silicone Composition] The present composition can be produced as a granular composition by powder mixing components (A) through (E) and any other optional components at a temperature of 100°C or less. There are no limitations on the powder mixer used in this production method, and examples include a single- or double-screw continuous mixer, a two-roll mill, a Ross mixer, a Hobart mixer, a dental mixer, a planetary mixer, a kneader mixer, a laboratory mill, a small grinder, and a Henschel mixer, with laboratory mills, small grinders, and Henschel mixers being preferred. A powdered curable silicone composition can be produced using these mixers, and this granular composition can be compressed using a tablet press or the like to produce a curable tablet composition for transfer molding.

[0083] In particular, when it is desired to use the present composition in compression molding or the like, it is preferable to go beyond simple mechanical mixing and melt-knead the composition at a temperature of 150°C or less using a single- or double-screw continuous mixer, a twin-roll mill, a Ross mixer, a kneader mixer, or the like, thereby molding the composition into a compositionally homogenized granular or sheet-like form for use.

[0084] This is because compression molding involves minimal material movement, and therefore requires a completely homogenized composition, unlike transfer molding. For example, a sheet made of a curable silicone composition with an average thickness of 100 to 1,000 μm possesses hot-melt properties and is heat-curable at high temperatures, making it advantageous in terms of ease of handling and melting characteristics, particularly when used in compression molding or vacuum lamination. Granules made of a curable silicone composition with a particle size of 0.1 to 10 mm possess hot-melt properties and are heat-curable at high temperatures, making them particularly suitable for compression molding, where large areas are sealed or bonded. Such sheet- or granular compositions can be produced by melt-kneading the curable granular composition obtained by the above-described method in a continuous kneader, or by separately feeding the components of the composition into a continuous kneader at a constant rate and melt-kneading them, followed by forming them into a sheet or granulating them using the method described below.

[0085] [Method for producing a curable silicone sheet] The curable silicone sheet of the present invention is characterized by containing components (A) to (E) as essential components, with other components contained as optional components, and its production method comprises the following steps 1 to 3. Step 1: Kneading the components of the curable silicone composition while heating and melting them Step 2: Laminating the heated and melted mixture obtained in step 1 between at least one film equipped with a release surface Step 3: Stretching the laminate obtained in step 2 between rolls to form a curable silicone sheet with a specific thickness Here, "having hot melt properties" means having a softening point in the range of 50°C to 200°C and having the property of softening or flowing when heated.

[0086] [Step 1] Step 1 described above involves kneading the components of the curable silicone composition of the present invention while heating and melting them. By heating and kneading the heat-meltable mixture at a temperature above its softening point, preferably in the range of 50°C to 150°C, and more preferably in the range of 50°C to 120°C, the entire composition melts or softens, allowing components (A) to (E) and any optional components to be uniformly dispersed throughout.

[0087] The mixing device used in step 1 is not particularly limited, and may be a batch type heat-kneading device equipped with heating and cooling functions, such as a kneader, Banbury mixer, Henschel mixer, planetary mixer, two-roll mill, three-roll mill, Ross mixer, or Laboplastomill, or a continuous type heat-kneading device equipped with heating and cooling functions, such as a single-screw extruder or twin-screw extruder, and is selected based on the efficiency of processing time and the ability to control shear heat generation. From the perspective of processing time, the device may be a continuous type heat-kneading device such as a single-screw extruder or twin-screw extruder, or a batch type mixer such as a Laboplastomill. However, from the standpoint of production efficiency of the curable silicone sheet, a continuous type heat-kneading device such as a single-screw extruder or twin-screw extruder is preferably used.

[0088] When the mixture is pressure-molded into a sheet in step 3 after step 2, a uniform, thin-layer molded sheet can be formed with a single press, which has the practical benefit of preventing molding defects and cracks in the sheet. On the other hand, if the temperature is below the lower limit, softening may be insufficient, making it difficult to obtain a molten or softened mixture in which the components are uniformly dispersed throughout, even with mechanical force. Even if such a mixture is pressure-molded into a sheet in step 4 after step 3, a uniform, thin-layer molded sheet cannot be formed, which may result in damage or cracks in the sheet. Conversely, if the temperature exceeds the upper limit, the curing agent may react during mixing, resulting in significant thickening or hardening of the entire mixture, resulting in loss of hot-melt properties and the formation of a cured product, which is undesirable. For this reason, it is preferable to use a platinum-containing hydrosilylation catalyst in the form of fine particles dispersed or encapsulated in a thermoplastic resin whose softening point is above the kneading temperature as component (D).

[0089] The components of the present invention can be fed into the kneading device described above by either feeding each component separately into the kneading device at a constant rate, or by mixing all of the components in powder form to form a granular curable silicone composition, which can then be fed into the kneading device.

[0090] [Step 2] Step 2 is a step in which the heat-melted mixture obtained in Step 1 is laminated between films having at least one release surface, and is a preliminary step for pressure molding in Step 3. By forming a laminate in which the mixture obtained in Step 1 is sandwiched between films, pressure molding by roll stretching can be performed from above the film to obtain a sheet-like molded product, and after molding, only the film can be removed from the sheet-like molded product using the release surface.

[0091] Depending on the form of use of the resulting curable silicone sheet, it is preferable that both of the two films have a release surface, and it is particularly preferable that the mixture obtained in step 1 be laminated between the release surfaces of the respective films in step 2. By adopting such a laminated form, after pressure molding in step 3 and subsequent optional cutting, it is possible to obtain a laminated sheet that can be peeled off from both sides, in which a thin layer of curable silicone sheet is sandwiched between release films, and when in use, the films on both sides can be peeled off to expose just the curable silicone sheet without concern for damaging the formed curable silicone sheet.

[0092] The substrate of the film used in step 2 is not particularly limited, and examples include paperboard, corrugated cardboard, clay-coated paper, polyolefin-laminated paper, particularly polyethylene-laminated paper, synthetic resin film / sheet, natural fiber cloth, synthetic fiber cloth, artificial leather cloth, and metal foil. Synthetic resin film / sheet is particularly preferred, and examples of synthetic resin include polyimide, polyethylene, polypropylene, polystyrene, polyvinyl chloride, polyvinylidene chloride, polycarbonate, polyethylene terephthalate, and nylon. When heat resistance is particularly required, films of heat-resistant synthetic resins such as polyimide, polyether ether ketone, polyethylene naphthalate (PEN), liquid crystal polyarylate, polyamide imide, and polyether sulfone are suitable. On the other hand, for applications requiring visibility, such as display devices, transparent substrates, specifically transparent materials such as polypropylene, polystyrene, polyvinylidene chloride, polycarbonate, polyethylene terephthalate, and PEN are suitable.

[0093] The thickness of the film is not particularly limited, but is usually about 5 to 300 μm.

[0094] The film preferably has at least one release layer, and this release layer is in contact with the mixture obtained in step 1. This allows the pressure-molded hot-melt curable silicone sheet to be easily released from the film via steps 2 and 3. The release layer is also called a release liner, separator, release layer, or release coating layer, and is preferably a release layer with release coating capability such as a silicone-based release agent, a fluorine-based release agent, an alkyd-based release agent, or a fluorosilicone-based release agent, or a substrate itself that forms physical microscopic irregularities on the surface of the substrate or that is difficult to adhere to the hot-melt curable silicone sheet of the present invention.

[0095] In step 2, the mixture obtained in step 1 is laminated between two films. There are no particular restrictions on the process, but the mixture obtained in step 1 is supplied by being discharged or applied onto the release layer of one of the films, and the release layer of the other film is then attached onto the mixture to form a laminate. During this process, in the continuous process for producing curable silicone sheets, each film is transported via a rotating roll to the position where the mixture from step 1 was supplied, and the lamination operation between the films is carried out.

[0096] The amount of the mixture obtained in step 1 that is supplied between the films in step 2 can be designed according to the production speed and scale. As an example, the mixture obtained in step 2 can be supplied between the films at a supply rate of 1 to 10 kg / hour, but it goes without saying that this is not limited to this. However, the amount of the mixture obtained in step 1 that is laminated between the films in step 2 must be determined according to the average thickness of the curable silicone sheet that is designed in step 3, and must be a thickness that allows for rolling processing in step 3.

[0097] When the mixture obtained in step 1 has a low heat-melt viscosity and is highly fluid, it is preferable that the heat-melted mixture obtained in step 1 is extruded while being molded into a film using a die and laminated between films in step 2. Here, the die is used to pre-mold the mixture, and the type and thickness at the time of pre-mold are not particularly limited, but a T-type die can be used to pre-mold into a substantially sheet-like shape having a thickness in the range of 100 to 2000 μm (= 2 mm), and this is preferable.

[0098] If the mixture obtained in step 1 has a low heat-melt viscosity and is highly fluid, it is preferable to include a step of cooling or temperature-adjusting the entire laminate obtained in step 2 after the pre-molding, either as a step prior to step 3 or in step 3. This is because cooling the heat-melt material to solidify it allows for effective pressure molding in step 3. The cooling step is not particularly limited, but can be carried out by cooling the mixture supplied or laminated on a film using a cooling roll or the like to a temperature within the range of -50°C to room temperature using air cooling or a cooling solvent or other cooling means. Details of the temperature adjustment will be described in step 3.

[0099] On the other hand, if the mixture obtained in step 1 has a high melt viscosity and poor fluidity, in step 2, the semi-solid mixture may be supplied onto a film and laminated without being pre-molded.

[0100] [Step 3] Step 3 is a step in which the laminate obtained in step 2 above is stretched between rolls to form a curable silicone sheet having a specific thickness, and in this step, the mixture obtained in step 1 is stretched from above the film under pressure to form a uniform curable silicone sheet.

[0101] The rolling process in step 3 can be carried out on the laminate obtained in step 2 using a known rolling method such as roll rolling. Roll rolling, in particular, has the advantage that a curable silicone sheet of the desired thickness can be designed by adjusting the gap between the rolls. For example, by rolling while adjusting the gap between the rolls to a constant value so that the average thickness is in the range of 10 to 2000 μm, a curable silicone sheet with excellent flatness and very few defects on the surface and inside the sheet can be obtained. More specifically, in the case of roll rolling, it is particularly preferable to adjust the gap between the rolls to a value in the range of 1.5 to 4.0 times the average thickness of the desired organopolysiloxane cured film.

[0102] A substantially flat curable silicone sheet having a thickness of 10 to 2000 μm can be obtained by performing the stretching in step 3. The mixture after heating and melting in step 1 can be roll-stretched in step 2 while laminated between release films to obtain a release laminate containing a curable silicone sheet with hot-melt properties that has few defects and excellent handling properties when peeled.

[0103] [Temperature Adjustment in Step 3] When the laminate obtained in Step 2 is stretched between rolls in Step 3, it is preferable that the rolls further have a temperature adjustment function, and adjust the temperature of the entire laminate during roll rolling, and heat or cool it as needed. This temperature adjustment has the practical benefit of maintaining a stable gap between the rolls and improving the flatness and uniformity (uniformity of film thickness) of the resulting hot-melt curable silicone sheet. The specific temperature adjustment range can be designed appropriately depending on the heat resistance of the film, the thickness (design thickness) of the curable silicone sheet, its reactivity, etc., but is generally within the range of 5 to 150°C.

[0104] [Cutting step] Step 3 can be used to obtain a release laminate in which a hot-melt curable silicone sheet is sandwiched between release films, but an optional step of cutting the laminate containing the curable silicone sheet may also be included. The curable silicone sheet may also be wound up using a winding device. This allows a release laminate containing a hot-melt curable silicone sheet of the desired size to be obtained.

[0105] [Laminate] The laminate obtained by the above steps is a laminate comprising components (A) to (E) of the present invention and any optional components, and has a structure in which a substantially flat, curable silicone sheet having hot melt properties and a thickness of 10 to 2000 μm is laminated between films having at least one release surface. Note that both of the films may and preferably have a release surface.

[0106] [Curable Silicone Sheet] The curable silicone sheet obtained by the production method of the present invention has hot-melt properties and exhibits tackiness and adhesiveness when heated and melted, and therefore has excellent formability, gap-filling properties, and adhesive strength, and can be used as a die attach film, film adhesive, or film sealant. It can also be suitably used as a curable silicone sheet for compression molding, press molding, and vacuum lamination.

[0107] Specifically, the curable silicone sheet obtained by the production method of the present invention is peeled from the release film and then placed in the desired location on a semiconductor or the like, and a film adhesive layer that takes advantage of its gap-filling properties for unevenness and gaps is formed on the adherend, and the adherends are temporarily fixed, positioned, and bonded together, and the curable silicone sheet may then be heated to 150°C or higher to bond the adherends together with the cured product of the curable silicone sheet. The release film may be peeled off after the curable silicone sheet has been heated to form a cured product, and the timing of peeling may be selected depending on the application and method of use of the curable silicone sheet.

[0108] Because the curable silicone sheet has hot-melt properties, it can be softened or fluidized by heating it before final curing, and even if the adherend surface is uneven, the unevenness or gaps can be filled without gaps to form an adhesive surface. As a heating means for the curable silicone sheet, for example, various thermostatic baths, hot plates, electromagnetic heating devices, heating rolls, etc. can be used. In order to perform lamination and heating more efficiently, for example, an electric heating press, a diaphragm-type laminator, a roll laminator, etc. are preferably used.

[0109] [Method for producing a granular curable silicone composition] The present composition is in the form of granules in which the entire composition containing at least the above components (A) to (E) has been homogenized in terms of composition beyond the extent of simple mechanical mixing. Such a granular composition is preferably obtained by melt-kneading the entire composition accompanied by heating. More specifically, components (A) to (E) and any other optional components are melt-kneaded in a single- or twin-screw continuous mixer, twin-roll mill, Ross mixer, kneader mixer, or the like at a temperature range of 50°C to 150°C, more preferably 50 to 120°C, and then molded into granules for use. Specific examples of production methods are given below.

[0110] The method for producing a granular curable silicone composition of the present invention comprises the steps of melt-kneading a curable silicone composition comprising the above-described components (A) to (E) and any other optional components, wherein the content of component (E) is in the range of 400 to 3,000 parts by mass per 100 parts by mass of the total of components (A) to (D), at a temperature range of 50 to 150°C, more preferably 50 to 120°C, and then molding the composition into granules having an average particle size in the range of 0.1 to 10.0 mm. The method is not particularly limited as long as the composition is molded into granules after melt-kneading, but it may, for example, include the following steps 1 to 3: Step 1: Kneading the components of the curable silicone composition while heating and melting them at a temperature range of 50 to 150°C, more preferably 50 to 120°C; Step 2: Cooling the heated and melted mixture obtained in step 1 while discharging it; and Step 3: Cutting or breaking the mixture obtained in step 2 to mold a granular curable silicone composition.

[0111] [Step 1] Step 1 described above involves kneading the components of the curable silicone composition of the present invention while heating and melting them at a temperature in the range of 50°C to 150°C, and more preferably 50 to 120°C. By heating and kneading the heat-meltable mixture at a temperature above its softening point, preferably in the range of 50°C to 120°C, the entire composition melts or softens, allowing components (A) to (E) and any optional components to be uniformly dispersed throughout.

[0112] The mixing device used in step 1 is not particularly limited, and may be a batch type heat-kneading device equipped with heating and cooling functions, such as a kneader, Banbury mixer, Henschel mixer, planetary mixer, two-roll mill, three-roll mill, Ross mixer, or Laboplastomill, or a continuous type heat-kneading device equipped with heating and cooling functions, such as a single-screw extruder or twin-screw extruder, and is selected based on the efficiency of processing time and the ability to control shear heat generation. From the perspective of processing time, the device may be a continuous type heat-kneading device such as a single-screw extruder or twin-screw extruder, or a batch type mixer such as a Laboplastomill. However, from the standpoint of production efficiency of the granular curable silicone composition, continuous type heat-kneading devices such as a single-screw extruder or twin-screw extruder are preferably used.

[0113] This mixture is then granulated in step 3 after passing through step 2, but if the temperature is below the lower limit, softening will be insufficient, making it difficult to obtain a molten or softened mixture in which the components are uniformly dispersed throughout, even when mechanical force is used; such a mixture may not have excellent uniformity among the components, and when the resulting granular curable silicone composition is used in a 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 significantly thicken or harden, losing its hot-melt properties and forming a cured product, which is undesirable. For this reason, it is preferable to use, as component (D), a fine particle hydrosilylation reaction catalyst dispersed or encapsulated in a thermoplastic resin whose softening point is above the kneading temperature.

[0114] The components of the present invention can be fed into the kneading device described above by either feeding each component separately into the kneading device at a constant rate, or by mechanically or other means powder-mixing all of the components to form a granular curable silicone composition, which can then be fed into the kneading device.

[0115] [Step 2] Step 2 is a step in which the mixture melted and kneaded in step 1 is discharged from the kneader. The mixture may be discharged in any shape, but since the mixture is cut and broken into granules in step 3, it is preferable that the mixture be in a shape that allows for easy cutting and breaking. Examples include a rod shape (strand shape) with a diameter of about 0.5 to 5.0 mm or a sheet shape with a thickness of about 0.5 to 5.0 mm. Since the mixture is preferably a non-sticky solid for granulation in step 3, the temperature of the discharged mixture must be lowered to near room temperature by natural cooling or rapid cooling. Examples of rapid cooling methods include a method using a cooler or water cooling.

[0116] [Step 3] Step 3 is a step in which the mixture discharged in step 2 is cut or broken to form granules. If the mixture is hard enough to be broken by shear stress alone at room temperature, it can be broken and granulated by passing it through a two-roll mill or the like. The size and shape of the granules obtained in step 3 can be adjusted to some extent by controlling the dimensions of the mixture discharged in step 2 and the gap between the rolls, and in the present invention, the average particle size of the granular molded product must be in the range of 0.1 to 10.0 mm. Furthermore, if the mixture cannot be broken down using a roll or the like, it is also possible to obtain granules by discharging the mixture as a rod-shaped mixture in step 2 and cutting it to a predetermined size using a rotary cutter or the like while cooling.

[0117] The granular curable silicone composition obtained by the manufacturing method of the present invention is highly uniform in composition, and is therefore less likely to become non-uniform or physically shift during molding, such as compression molding, press molding, or lamination. This has the advantage that the entire composition can be easily molded uniformly, and it can be suitably applied even to molding processes that do not generate shear pressure. Furthermore, since the above advantages are not lost even when the granular composition is subjected to secondary molding, the granular curable silicone composition can be compressed or tableted using a tablet press or the like and used as tablets or pellets for transfer molding.

[0118] [Cured Product] The curable silicone composition described above has hot-melt properties, and in addition to exhibiting excellent flowability during melting (hot-melt), ease of handling, and curing properties, it also exhibits high hardness at room temperature to high temperatures upon curing, and exhibits excellent mechanical strength, typified by a low coefficient of linear expansion and high bending strength, resulting in a tough cured product with excellent bonding strength to substrates, making it suitable for semiconductor components and the like. In view of the molding method described below, the composition is preferably cured by heat curing 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, bending strength, and hardness, can be easily designed to fall within the following preferred ranges based on the type of component (A) and component (E) and the quantitative range of component (D).

[0119] [Linear Expansion Coefficient of Cured Product] The cured product obtained by curing the composition has an average linear expansion coefficient of 30 ppm / °C or less, preferably 20 ppm / °C or less, and more preferably 15 ppm / °C or less, in the temperature range of 25°C to 200°C. Within this range, the difference in average linear expansion coefficient from the substrate to be used is small, so that residual stress in the obtained integrally molded product can be reduced, and device reliability can be improved.

[0120] [Flexural Strength of Cured Product] Furthermore, since the cured product is suitable as an encapsulant for semiconductors, which requires high hardness and strength, the flexural strength of the cured product measured by the method specified in JIS K 6911-1995 "General Testing Methods for Thermosetting Plastics" is preferably 15 MPa or more, or 20 MPa or more.

[0121] [Hardness of the Cured Product] Because the composition is suitable for use as a protective material for semiconductors, etc., the cured product obtained by curing the composition preferably has a Type D durometer hardness at 25°C of at least 20. The Type D durometer hardness is determined using a Type D durometer in accordance with JIS K 6253-1997 "Testing method for hardness of vulcanized rubber and thermoplastic rubber."

[0122] [Method for molding a cured product] The composition can be cured by a method comprising 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 obtained in step (I) into a mold, or a step of spreading the curable silicone composition obtained in step (I) throughout the mold by clamping the mold; and (III) a step of curing the curable silicone composition injected in step (II).

[0123] The present composition can be suitably used in a molding method including a coating step (so-called mold underfill method) in which overmolding and underfilling of semiconductor elements are performed simultaneously. Furthermore, due to the above-mentioned properties, the present composition can be suitably used in a molding method including a coating step (so-called wafer molding) in which the surface of a semiconductor substrate (including a wafer substrate) carrying a single or multiple semiconductor elements is covered and overmolded so that gaps between the semiconductor elements are filled with the cured product.

[0124] In the above steps, a transfer molding machine, a compression molding machine, an injection molding machine, an auxiliary ram molding machine, a slide molding machine, a double ram molding machine, a low-pressure encapsulation molding machine, a vacuum lamination machine, etc. In particular, the composition of the present invention is suitable for use in obtaining a cured product by transfer molding and compression molding.

[0125] Finally, in step (III), the curable silicone composition injected (applied) in step (II) is cured.

[0126] Since the composition is suitable for use as a protective material for semiconductors and the like, it is preferable that the cured product obtained by curing the composition have a Type D durometer hardness at 25°C of at least 20. The Type D durometer hardness is determined using a Type D durometer in accordance with JIS K 6253-1997 "Testing method for hardness of vulcanized rubber and thermoplastic rubber."

[0127] [Uses of the Composition] The composition has hot-melt properties and excellent flowability, handling, and curing properties during melting (hot-melt). Therefore, it is suitable for use as an encapsulant or underfill agent for semiconductors; an encapsulant or underfill agent for power semiconductors such as SiC or GaN; an encapsulant or light-reflecting material for optical semiconductors such as light-emitting diodes, photodiodes, phototransistors, and laser diodes; and an adhesive, potting agent, protective agent, and coating agent for electrical and electronic applications. Furthermore, because the composition has hot-melt properties, it is also suitable as a material for transfer molding, compression molding, or injection molding. It is particularly suitable for use as an encapsulant for semiconductors that use mold underfill or wafer molding methods during molding. Furthermore, sheets of the composition can be used as curable film adhesives or as stress buffer layers between two substrates with different linear expansion coefficients.

[0128] As described above, the present composition is suitable as a sealant for semiconductors, and by using the composition to replace part or all of a conventionally known sealant in the process of sealing semiconductors and the like by molding methods such as an overmolding method using a conventionally known sealant (including non-silicone hot-melt sealants such as epoxy sealants), an underfill method, a mold underfill method in which these are performed at the same time, or a wafer molding method, it is possible to produce semiconductor / optical components such as 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 optical waveguides connected to electrical wiring boards and connectors. For example, the curable silicone composition according to the present invention is disclosed in Japanese Patent Application Laid-Open No. 2021-097123, Japanese Patent Application Laid-Open No. 2021-024945, Japanese Patent Application Laid-Open No. 2020-132771, Japanese Patent Application Laid-Open No. 2020-132750, Japanese Patent Application Laid-Open No. 2020-125399, Japanese Patent Application Laid-Open No. 2020-123670, Japanese Patent Application Laid-Open No. 2020-084094, Japanese Patent Application Laid-Open No. 2020-088055, Japanese Patent Application Laid-Open No. 2019-006905, Japanese Patent Application Laid-Open No. 2018-188494, Japanese Patent Application Laid-Open No. 2017-179185, Japanese Patent Application Laid-Open No. 2020-023643, Japanese Patent Application Laid-Open No. 2020-063459, Japanese Patent Application Laid-Open No. 2020-090634, Japanese Patent Application Laid-Open No. 2020-088055, It can be used in place of some or all of the sealants (especially silicone elastomer sealants, pastes containing functional fillers, and hot-melt sealants) described in JP 2020-107767, JP 2021-080411, JP 2021-036013, JP 2020-152844, JP 2020-158684, JP 2021-019031, JP 2021-059741, JP 2020-057775, JP 2021-015985, JP 2015-114390, JP 2016-177106, etc. If necessary, the technical elements applied to these sealant compositions may be applied to the present invention, and the composition of the present invention may be adjusted in terms of its composition, physical properties and melting characteristics of the cured product, etc., and is preferred.

[0129] [Uses of the cured product] The uses of the cured product of the present invention are not particularly limited, but the composition of the present invention has hot-melt properties and excellent moldability, and the cured product has excellent adhesive properties, a high modulus of elasticity, and a low coefficient of linear expansion. Therefore, the cured product obtained by curing the composition of the present invention can be suitably used as a member for semiconductor devices, and can be suitably used as an encapsulant for semiconductor elements, IC chips, etc., or as a light reflector for optical semiconductor devices.

[0130] The semiconductor device having a member made of the cured product of the present invention is not particularly limited, but is preferably a semiconductor device mounted on a power semiconductor device, an optical semiconductor device, or a flexible semiconductor device that is stretchable or deformable.

[0131] The hot-melt curable silicone composition of the present invention and its production method are described in detail below using examples and comparative examples. In the formula, Me, Ph, and Vi represent methyl, phenyl, and vinyl groups, respectively. The softening point and melt viscosity of the curable silicone composition of each example and comparative example were measured using the following methods. The curable silicone composition was heated at 180°C for 2 hours to produce a cured product, and the adhesive strength to various substrates was measured using the following method. The results are shown in Table 1.

[0132] [Softening Point of Curable Silicone Composition] The curable silicone composition was molded into a cylindrical pellet measuring φ14 mm x 22 mm. This pellet was 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 the load was removed, the deformation of the pellet was measured. The softening point was determined as the temperature at which the deformation in the height direction reached 1 mm or more.

[0133] [Melt Viscosity] The melt viscosity of the curable silicone composition at 180°C was measured using a 1.0 mm diameter nozzle under a pressure of 100 kgf using a high-performance flow tester CFT-500EX (manufactured by Shimadzu Corporation). [Cure Properties] The curable silicone composition was vulcanized for 600 seconds at the molding temperature (180°C) using a Curelastometer (registered trademark) (PREMIER MDR manufactured by Alpha Technologies) in accordance with the method specified in JIS K 6300-2:2001 "Unvulcanized rubber - Physical properties - Part 2: Determination of vulcanization properties using an oscillatory vulcanization tester," and the cure properties were measured. The measurement was performed by weighing out approximately 5 g of a block of the curable hot-melt silicone composition, sandwiching it between 50 μm-thick PET films, and placing it on the lower die. The measurement began when the upper die closed. Measurements were made using an R-type rubber die with an amplitude angle of 0.53°, a frequency of 100 rpm, and a maximum torque range of 230 kgf cm. The measurement result was the time (ts-1) required for the torque value to exceed 1 dNm, read in seconds. [Storage Stability] The curable silicone composition was aged in an oven at 40°C for one week, and the curing characteristics were measured using the method described above, and the ts-1 value was read.

[0134] [Flexural Strength of Cured Product] A cured product was produced by heating the curable silicone composition for 2 hours at 180° C. The flexural strength of this cured product was measured according to the method specified in JIS K 6911-1995 "General Testing Methods for Thermosetting Plastics."

[0135] [Die Shear Strength] Approximately 500 mg of the curable silicone composition was placed in four locations on various 25 mm x 75 mm substrates. Next, a 10 mm square glass chip with a thickness of 1 mm was placed over the composition, and the composition was cured by heating for 2 hours at a temperature of 180°C while thermocompressing it with a 1 kg plate. The composition was then cooled to room temperature, and the die shear strength was measured using a shear strength measuring device (Bond Tester SS-100KP, manufactured by Seishin Shoji Co., Ltd.). [Linear Expansion Coefficient Curve of the Cured Product] The curable silicone composition was cured using the method described above to produce a cured product. The linear expansion coefficient of the cured product was measured over a temperature range of 20°C to 200°C using a TM9200 manufactured by Shinku Riko Co., Ltd.

[0136] Organopolysiloxane resins containing a hydrosilylation catalyst were prepared by the methods shown in Reference Examples 1 and 2 below, and organopolysiloxane resin microparticles were prepared by the methods shown in Reference Examples 3 and 4. The presence or absence of hot-melt properties was evaluated based on the presence or absence of softening point / melt viscosity. In the Reference Examples, 1,1,3,3-tetramethyl-1,3-divinyldisiloxane used in the platinum complex serving as the hydrosilylation catalyst is referred to as "1,3-divinyltetramethyldisiloxane."

[0137] [Reference Example 1] In a 1 L flask, a white solid having the average unit formula: (PhSiO ３ / ２ ) ０.８０ (Me ２ ViSiO １ / ２ ) ０.２０ A toluene solution of resinous organopolysiloxane (1) was prepared by dissolving 550 g of a resinous organopolysiloxane represented by the formula: (PhSiO) in 450 g of toluene. The softening point of this resinous organopolysiloxane (1) was 100°C, and its viscosity at 150°C, as measured with a rotational viscometer, was 30 Pa s. [Reference Example 2] A white solid having the average unit formula: (PhSiO) was added to a 1 L flask at 25°C. ３ / ２ ) ０.８０ (Me ２ ViSiO １ / ２ ) ０.２０ A toluene solution of resinous organopolysiloxane (2) containing 10 ppm by mass of platinum metal was prepared by adding 270.5 g of a 55% by mass toluene solution of a resinous organopolysiloxane represented by the formula (I) and 0.034 g of a 1,3-divinyltetramethyldisiloxane solution of a platinum 1,3-divinyltetramethyldisiloxane complex (platinum metal content = approximately 4000 ppm) and stirring uniformly at room temperature (25°C). The softening point of this resinous organopolysiloxane (2) was 100°C, and its viscosity at 150°C, as measured by a rotational viscometer, was 30 Pa s.

[0138] Reference Example 3: Hot-melt organopolysiloxane resin microparticles (1) A toluene solution of the resinous organopolysiloxane (1) prepared in Reference Example 1 was spray-dried at 40°C to remove the toluene, thereby producing spherical hot-melt silicone microparticles (1). When the microparticles were observed under an optical microscope, they had a particle size of 5 to 10 μm, with an average particle size of 7.9 μm.

[0139] Reference Example 4: Hot-melt organopolysiloxane resin microparticles (2) A toluene solution of the platinum-containing dendritic organopolysiloxane (2) prepared in Reference Example 2 was atomized by spray drying at 40°C while removing the toluene, to prepare spherical hot-melt silicone microparticles (2). When the microparticles were observed under an optical microscope, they had a particle size of 5 to 10 μm, with an average particle size of 7.8 μm.

[0140] [Reference Example 5: Resinous organopolysiloxane solution] (A1) 57.2 g of the resinous organopolysiloxane fine particles obtained in Reference Example 3 was mixed with a solution of a compound represented by the formula: (C1) ２ SiO(Ph ２ SiO)SiMe ２ 2.9 g of a diphenylsiloxane (C2) having an average unit formula of (PhSiO) and having a viscosity of 5 mPa s and a molecular chain end-blocked with dimethylhydrogensiloxy groups (content of silicon-bonded hydrogen atoms = 0.6 mass%), represented by H ３ / ２ ) ０.４ (HMe ２ SiO １ / ２ ) ０.６A transparent resinous organopolysiloxane solution 1 was prepared by adding 22.3 g of a branched-chain organopolysiloxane having two or more silicon-bonded hydrogen atoms per molecule (silicon-bonded hydrogen atom content=0.65% by mass) represented by the formula: and stirring at 60° C. for 30 minutes. [Examples 1 to 12, Comparative Examples 1 to 4] The following components were used in the examples and comparative examples of the present application. (E) Inorganic filler (E1) Fused silica having an average particle size of 14.5 μm (S6105P manufactured by Nippon Steel Materials Micron Co., Ltd.) (E2) Fused silica having an average particle size of 0.7 μm (SPH507M manufactured by Nippon Steel Materials Micron Co., Ltd.) (E3) Fused silica having an average particle size of 17.0 μm (S6050P manufactured by Nippon Steel Materials Micron Co., Ltd.) (E4) Carbon black having an average particle size of 35 nm (Denka Black Pressed product manufactured by Denka Co., Ltd.) (es) Treatment agent for inorganic filler (es-1) Me ２ ViSiO(Me ２ SiO) ２９ Si(OMe) ３ Dimethylpolysiloxane (viscosity 23 mPas) represented by (es-2)Me ３ SiO(Me ２ SiO) １１０ Si(OMe) ３ (H) Wax (H) Calcium stearate (manufactured by Kawamura Chemicals) (A) Hot-melt organopolysiloxane resin (A1) Hot-melt organopolysiloxane resin microparticles (1) of Reference Example 3 (A2) Hot-melt organopolysiloxane resin microparticles (2) of Reference Example 4 *Containing a platinum catalyst (A3) Resinous organopolysiloxane solution 1 of Reference Example 5 (a mixture of components (A1), (C1), and (C2)) (B) Organosiloxane compound (B1) Formula: (ViMe ２ SiO １／２ ) ０．７５ (PhSiO ３／２ ) ０．２５ (B2) A branched organopolysiloxane containing vinyl groups at the molecular terminals and having a viscosity of 5 mPa·s (vinyl group content=23% by mass), represented by the formula: (ViMe ２ SiO) ２ SiPh２ (B3) A linear organopolysiloxane containing vinyl groups at the molecular terminals and having a viscosity of 8 mPa·s (vinyl group content=16% by mass), represented by the formula: (ViMe ２ SiO １／２ ) ０．８０ (SiO ４／２ ) ０．２０ (B4) A branched organopolysiloxane containing vinyl groups at the molecular terminals and having a viscosity of 3 mPa·s (vinyl group content=27% by mass), represented by the formula: (Me ２ Visio １ / ２ ) ０.５５ (Me ３ SiO １ / ２ ) ０.０５ (SiO ４ / ２ ) ０.４０ (B'1) A branched organopolysiloxane containing vinyl groups at the molecular terminals (vinyl group content = 19% by mass) having a viscosity of 300 mPa·s, represented by the formula: ViMe ２ SiO(MePhSiO) １７.５ SiViMe ２ (B'2) A linear organopolysiloxane containing vinyl groups at the molecular terminals (vinyl group content = 1.5 mass%) having a viscosity of 900 mPa s, represented by the formula: ViMe ２ SiO(MePhSiO) ９２ SiViMe ２ (B'3) A linear organopolysiloxane containing vinyl groups at the molecular terminals and having a viscosity of 15,000 mPa·s (vinyl group content=0.6% by mass), represented by the formula: (MeViSiO) ４ (C) SiH siloxane (C1) Formula: HMe ２ SiO(Ph ２ SiO)SiMe ２ Diphenylsiloxane capped at both molecular chain ends with dimethylhydrogensiloxy groups, having a viscosity of 5 mPa s and represented by H (content of silicon-bonded hydrogen atoms = 0.6 mass%) (C2) average unit formula: (PhSiO ３ / ２ ) ０.４ (HMe ２ SiO １ / ２ )０.６ (D) Hydrosilylation reaction catalyst: (D1) Thermoplastic polycarbonate resin containing 4000 ppm of platinum in a 1,3-divinyl-1,1,3,3-tetramethyldisiloxane complex of Pt (0 valent) (softening point of thermoplastic resin: 150°C) *Platinum metal amount shown in ppm in Table 1. (F) Inhibitor: (F1) Methyltris-1,1-dimethyl-2-propynyloxysilane (boiling point: 245°C (1013.25 hPa, an amount equivalent to 300 ppm by mass of the composition)). (F2) 1-ethynyl-1-cyclohexanol (an amount equivalent to 300 ppm by mass of the composition). (G) Adhesion promoter (G1) Bis(trimethoxysilylpropoxymethyl)vinylsilatrane (G2) Bis(trimethoxysilylpropoxymethyl)allylsilatrane (G3) Formula: (Me ２ Visio １ / ２ ) ０.２ (MeEpSiO ２ / ２ ) ０.２５ (PhSiO ３ / ２ ) ０.５５ (HO １ / ２ ) ０.００５ An epoxy group-containing polysiloxane represented by the formula:

[0141] For Examples 1 to 5, 7 to 12, and Comparative Examples 1 to 4, uniform granular white or black curable silicone compositions were prepared using the procedure shown below. For Example 6, on the other hand, all components were added to a small grinder at once using the following procedure. The composition, number of parts, and SiH / Vi ratio of each composition are shown in Table 1. Furthermore, the softening viscosity, melt viscosity, TS-1, flexural strength, linear expansion coefficient, and die shear values ​​for each composition are shown in Table 2.

[0142] Examples 1 to 5, 7 to 12, Comparative Examples 1 to 4 (E) inorganic filler, (H) wax, and (es) inorganic filler treatment agent were all charged into a small pulverizer and stirred for 1 minute at 100° C. The inorganic filler (E) was surface-treated, and the pulverizer temperature was then returned to 25° C. Next, (A) hot-melt organopolysiloxane resin, (B) organopolysiloxane compound, (C) SiH siloxane (an amount such that the number of moles of silicon-bonded hydrogen atoms in component (C) would satisfy the SiH / Vi ratio shown in the table per 1.0 mole of vinyl groups in the composition), (F) inhibitor, (G) adhesion promoter, and (D) hydrosilylation reaction catalyst were added to the small pulverizer and stirred for 1 minute at room temperature (25° C.) to prepare a uniformly granular white or black curable silicone composition.

[0143] Example 6 (A) hot-melt organopolysiloxane resin, (B) organopolysiloxane compound, (C) SiH siloxane (an amount such that the number of moles of silicon-bonded hydrogen atoms in component (C) per 1.0 mole of vinyl groups in the composition satisfies the SiH / Vi ratio shown in the table), (F) inhibitor, (G) adhesion promoter, (D) hydrosilylation reaction catalyst, (E) inorganic filler, (H) wax, and (es) inorganic filler treatment agent were added to a small grinder and stirred at room temperature (25°C) for 1 minute, yielding a uniform, granular white curable silicone composition.

[0144]

[0145]

[0146] [Summary] It was found that the curable silicone compositions of Examples 1 to 12 according to the present invention possess good hot-melt properties and cure rates, and that the cured products have a low coefficient of linear expansion and exhibit practically sufficient mechanical strength, including bending strength and die shear strength. Furthermore, in all Examples except Example 6, a low melt viscosity was achieved.

[0147] On the other hand, in Example 6, it was found that pre-treatment of the inorganic filler (E) with a specific treatment agent was preferable in terms of the melt viscosity of the final composition. Furthermore, the results of Examples 7 and 8 indicate that a specific compound is preferable for the optional component (F), and that a specific catalyst is also preferable for component (D). The results of Example 9 indicate that the use of a specific crosslinking agent in combination with component (C) is effective, and the results of Example 10 confirm that the use of a specific carbasilatrane compound as component (G) further improves adhesive strength.

[0148] On the other hand, the results of Comparative Examples 1 to 4 show that compositions lacking the component (B) of the present invention did not fully achieve the technical effects of the present invention. Specifically, Comparative Examples 1 to 3, which did not contain the component (B) of the present invention or used an organosiloxane component with a different structure, were unable to achieve both a low melt viscosity in the hot-melt composition and mechanical strength of the cured product. Furthermore, Comparative Example 4 was unable to achieve a practical curing rate, and curing was extremely slow, making it difficult to apply to processes such as encapsulation of semiconductors.

[0149] <Preparation Example 1> A granulated curable silicone composition such as that from Example 1 above is heated to 80°C and melt-kneaded using a twin-screw extruder, and the resulting semi-solid softened material is fed onto a release film (Biwa Liner, manufactured by Takaline Corporation) at a feed rate of 5 kg / hour and laminated between two release films. The laminate is then stretched between rolls to form a laminate in which a 500 μm-thick hot-melt curable silicone sheet is laminated between two release films, and the entire structure is cooled using a cooling roll set to -15°C. By separating the release film from the laminate, a flat and uniform hot-melt curable silicone sheet can be obtained.

[0150] Production Example 2 A granulated curable silicone composition such as that from Example 1 above was heated to 80°C, melt-kneaded using a twin-screw extruder, and molded into a roughly sheet-like shape using a T-die (opening dimensions: 800 μm × 100 mm, heated to 80°C). The resulting composition was then fed onto a release film (Biwa Liner, manufactured by Takaline Corporation) at a rate of 5 kg / hour. The entire composition was cooled using a cooling roll set to −15°C, and then laminated between two release films. The laminate was then stretched between the rolls to form a laminate in which a 500 μm-thick hot-melt curable silicone sheet was laminated between two release films. Separating the release films from the laminate afforded a flat, uniform hot-melt curable silicone sheet.

Claims

1. (A) １ ３ SiO １／２ ) ａ (R ２ ２ SiO ２／２ ) ｂ (R ２ SiO ３／２ ) ｃ (SiO ４／２ ) ｄ (R ３ O １／２）ｅ (In the formula, each R １ are independently monovalent hydrocarbon groups having 1 to 10 carbon atoms, provided that all R １ At least two of R are alkenyl groups, and each R ２ are independently monovalent hydrocarbon groups having 1 to 10 carbon atoms, not including alkenyl groups; each R ３ represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms; and a, b, c, d, and e are numbers that satisfy the following: 0.10≦a≦0.40, 0≦b≦0.05, 0.30≦c≦0.90, 0≦d≦0.20, 0≦e≦0.05, with the proviso that a+b+c+d=1. A hot-melt organopolysiloxane resin represented by the formula: (B)(R １ ３ SiO １／２ ) ａ´ (R ２ ２ SiO ２／２ ) ｂ´ (R ２ SiO ３／２ ) ｃ´ (SiO ４／２ ) ｄ´ (R ３ O １／２）ｅ´ (In the formula, each R １ are independently monovalent hydrocarbon groups having 1 to 10 carbon atoms, provided that all R １ At least two of R are alkenyl groups, and each R ２ are independently monovalent hydrocarbon groups having 1 to 10 carbon atoms, not including alkenyl groups; each R ３ represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms; and a', b', c', d', and e' are numbers that satisfy the following: 0.40≦a'≦0.80, 0≦b'≦0.90, 0≦c'≦0.60, 0≦d'≦0.50, 0≦e'≦0.05, with the proviso that a'+b'+c'+d'=1. an organosiloxane compound containing 10 mass % or more of alkenyl groups in one molecule, represented by the formula: (C) an organohydrogensiloxane compound having at least two silicon-bonded hydrogen atoms per molecule; (D) a hydrosilylation catalyst in an amount sufficient to effect a hydrosilylation reaction of the reactive silicone composition; and (E) Functional inorganic filler: 400 to 3,000 parts by mass per 100 parts by mass of the total of components (A) to (D). and A curable silicone composition that is solid at 25°C and has hot-melt properties at temperatures up to 200°C.

2. The curable silicone composition according to claim 1, further comprising, as component (F), 1 to 5,000 ppm, based on the total mass of the composition, of a hydrosilylation reaction cure retarder having a boiling point of 200°C or higher at atmospheric pressure.

3. 2. The curable silicone composition according to claim 1, further comprising, as component (G), one or more adhesion promoters selected from silatrane derivatives and carbasilatrane derivatives.

4. The curable silicone composition according to claim 1, further comprising, as component (H), an organic wax component (different from component (A)) having a melting point in the range of 30 to 160°C.

5. The component (C) is a compound represented by the general formula: HR ４ ２ SiO(R ４ ２ SiO) ｎ SiR ４ ２ H A linear organopolysiloxane represented by the formula: (C-2) Average unit formula: (R ４ SiO ３／２ ) ｐ (R ４ ２ SiO ２／２ ) ｑ (HR ４ ２ SiO １／２ ) ｒ (SiO) ４／２ ) ｓ (XO １／２ ) ｔ A branched-chain organopolysiloxane represented by (In the formula, R ４ are the same or different, phenyl groups or alkyl groups having 1 to 6 carbon atoms, and all R ４ wherein the phenyl group content is within the range of 30 to 70 mol %; n is an integer ranging from 1 to 50, 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, q / p is a number ranging from 0 to 10, r / p is a number ranging from 0.1 to 5, s / (p+q+r+s) is a number ranging from 0 to 0.3, and t / (p+q+r+s) is a number ranging from 0 to 0.

4. wherein the ratio of (C-1):(C-2) per alkenyl group in the entire composition is in the range of 0.05-0.6:0.4-0.

95.

6. The curable silicone composition according to claim 1, wherein component (D) is platinum-based catalyst-containing thermoplastic resin fine particles having a glass transition temperature of 80°C or higher (in an amount such that the platinum metal in the fine particles is 0.1 to 2,000 ppm by mass relative to the composition).

7. 2. The curable silicone composition according to claim 1, wherein component (E) has been treated with a silicone-based surface treatment agent that contains at least one polysiloxane structure and a hydrolyzable silyl group within the molecule.

8. 2. The curable silicone composition according to claim 1, which upon curing gives a cured product having an average coefficient of linear expansion of 30 ppm / °C or less in the range of 25°C to 200°C.

9. The curable silicone composition according to claim 1, wherein upon curing, the composition gives a cured product having a flexural strength of at least 15 MPa, as measured according to the method specified in JIS K 6911-1995 "General Testing Methods for Thermosetting Plastics."

10. 2. The curable silicone composition according to claim 1, wherein component (E) is a reinforcing filler, a pigment, a thermally conductive filler, an electrically conductive filler, a phosphor, or a mixture of at least two of these.

11. 2. The curable silicone composition according to claim 1, which is in the form of particles, granules, pellets, or a sheet.

12. A cured product obtained by curing the curable silicone composition according to any one of claims 1 to 11.

13. A member for a semiconductor device, comprising the cured product of claim 12.

14. A semiconductor device comprising the cured product of claim 12.

15. A method for molding a cured product, 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 11 to a temperature of 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) throughout the mold; and (III) A step of curing the curable silicone composition injected in the step (II).

16. A method for molding the cured product according to claim 15, comprising a coating step in which overmolding and underfilling of a semiconductor element are carried out simultaneously with the cured product obtained by curing the curable silicone composition according to any one of claims 1 to 11.

17. A method for molding a cured product according to claim 15, comprising a covering step of covering the surface of a semiconductor substrate carrying one or more semiconductor elements with a cured product obtained by curing the curable silicone composition according to any one of claims 1 to 11, and overmolding the surface so that gaps between the semiconductor elements are filled with the cured product.