Epoxy resin composition

Abstract

To provide a novel epoxy resin composition and the like. Provided is an epoxy resin composition that contains silicone elastomer particles and silicone resin-coated silicone elastomer particles containing a silicone resin coating covering all or part of the surface of the silicone elastomer particles. The silicone elastomer particles have a structure in which at least two silicon atoms are crosslinked by a C2-20 silalkylene group. The silicone resin coating contains one or more silicone resins selected from one or a combination of two or more silicone resins selected from i) M siloxane units represented by R3SiO1 / 2 (R is a monovalent organic group), ii) D siloxane units represented by R2SiO2 / 2 (R is a monovalent organic group), iii) T siloxane units represented by RSiO3 / 2 (R is a monovalent organic group), and iv) Q siloxane units represented by SiO4 / 2 (however, excluding silicone resins comprising only T siloxane units), and the epoxy resin composition is free of volatile solvents.

Description

Epoxy resin composition

[0001] The present invention relates to an epoxy resin composition, a cured product of the epoxy resin composition, a semiconductor device including the cured product, and a method for producing a semiconductor device.

[0002] In recent years, electronic devices such as mobile phones, smartphones, ultra-thin LCD displays, plasma TVs, and lightweight laptop computers have become increasingly miniaturized. This has led to increased integration and packaging density of electronic components, such as semiconductor devices, used in these electronic devices. Demand for encapsulation of large-area devices, such as wafer-level packages and panel-level packages, is also increasing. Resin materials used in these electronic components have issues with warping after molding and delamination between components during the solder reflow process, necessitating the reduction of thermal stress during manufacturing and use. Thermal stress is generated by residual strain caused by volumetric changes in the encapsulating resin composition. To reduce this residual strain, it is necessary to suppress both the cure shrinkage caused by volumetric reduction due to the polymerization / crosslinking reaction of the encapsulating resin composition and the thermal shrinkage caused by cooling after encapsulation. To reduce thermal stress, for example, Patent Document 1 (Patent Document 1) discusses increasing the filler content of epoxy resins. While increasing the filler content can reduce the thermal expansion coefficient of the epoxy resin, the effect of suppressing warpage may not be sufficient when the support is large, as in wafer-level packages and panel-level packages. Furthermore, the cured product's elastic modulus increases and its strength decreases, potentially resulting in damage to Si chips or substrates during heat cycle tests during manufacturing processes such as solder reflow or during use. Patent Document 2 discloses another method for reducing thermal stress: adding an epoxy-modified silicone to an epoxy resin to reduce its elastic modulus. While this method is effective in reducing thermal stress, it does not sufficiently reduce the coefficient of thermal expansion. In particular, it does not sufficiently reduce the coefficient of thermal expansion in temperatures lower than the glass transition temperature. Furthermore, when a redistribution layer (RDL) is formed after encapsulation with an encapsulating resin composition, a material for forming the RDL is applied to the cured product of the encapsulating resin composition. In this case, a varnish prepared by diluting polyimide with a solvent is used, and the polyimide must have excellent wettability (hereinafter also referred to as "polyimide wettability") with respect to the cured product of the encapsulating resin composition.However, when a liquid additive such as an epoxy-modified silicone is used, if it has poor compatibility with the resin composition, it bleeds out onto the surface of the cured product, impairing the wettability of the polyimide.

[0003] JP 2013-010940 A International Publication No. 2021 / 149727

[0004] Under these circumstances, the present invention provides a novel epoxy resin composition and the like.

[0005] The present invention provides the following epoxy resin composition etc.: [1] An epoxy resin composition comprising silicone elastomer particles and silicone resin-coated silicone elastomer particles comprising a silicone resin coating that coats a part or all of the surface of the silicone elastomer particles, wherein the silicone elastomer particles have a structure in which at least two silicon atoms are crosslinked by a silalkylene group having 2 to 20 carbon atoms, and the silicone resin coating comprises: i) R ３ SiO １／２ (R is a monovalent organic group) ２ SiO ２／２ (R is a monovalent organic group), and iii) a D siloxane unit represented by RSiO ３／２ (R is a monovalent organic group), and iv) SiO ４／２ [2] An epoxy resin composition comprising one or more silicone resins selected from silicone resins consisting of one or a combination of two or more selected from the group consisting of Q siloxane units represented by the formula: and (excluding silicone resins consisting only of T siloxane units), wherein the epoxy resin composition does not contain a volatile solvent. ４ / ２The epoxy resin composition according to [1], which contains a Q siloxane unit represented by the following formula: [3] The epoxy resin composition according to [1] or [2], which has an average primary particle diameter of 0.1 to 100 μm as measured by a laser diffraction scattering method. [4] The epoxy resin composition according to any one of [1] to [3], in which the silicone resin-coated silicone elastomer particles do not contain an ionic surfactant. [5] The epoxy resin composition according to any one of [1] to [4], in which the silicone elastomer particles in a state not coated with the silicone resin coating have a JIS-A hardness of 80 or less and a JIS-E hardness of 1 or more, as measured after curing a crosslinkable composition for forming silicone elastomer particles into a sheet before curing. [6] The silicone resin coating is １ ２ SiO ２／２ (R １ are independently a D siloxane unit represented by an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, an alkyl group having 1 to 20 carbon atoms and an epoxy group, or an aryl group having 6 to 20 carbon atoms and an epoxy group), and SiO ４／２and a Q siloxane unit represented by the formula: [7] The epoxy resin composition according to any one of [1] to [5], wherein the crosslinkable composition for forming silicone elastomer particles before curing, for silicone elastomer particles not coated with the silicone resin coating, comprises: (a) an organopolysiloxane having at least two alkenyl groups having 2 to 20 carbon atoms per molecule, (b) an organohydrogenpolysiloxane having at least two hydrogen atoms bonded to silicon atoms per molecule, and (c) a hydrosilylation reaction catalyst, wherein the molar ratio of the content of alkenyl groups (Alk (mol)) in component (a) to the content of hydrogen atoms bonded to silicon atoms (H (mol)) in component (b) is in the range of H / Alk = 0.5 to 1.5. [8] A cured product obtained by curing the epoxy resin composition according to [7]. [9] A semiconductor device comprising the cured product according to [8].

[10] A method for manufacturing a semiconductor device, comprising curing the epoxy resin composition according to [7].

[0006] According to one aspect of the present invention, there is provided an epoxy resin composition in which the support after encapsulation maintains sufficient strength, thermal expansion is suppressed, and molding shrinkage is unlikely to occur, thereby suppressing warpage of semiconductors and the like comprising the cured product, and the epoxy resin composition has excellent polyimide wettability.

[0007] The upper and lower limit values ​​of the numerical ranges described herein can be arbitrarily combined. For example, when a numerical range is described as "preferably 30 to 100, more preferably 40 to 80," the ranges "30 to 80" and "40 to 100" are also included in the numerical ranges described herein. Furthermore, when a numerical range is described as "preferably 30 or more, more preferably 40 or more, and preferably 100 or less, more preferably 80 or less," the ranges "30 to 80" and "40 to 100" are also included in the numerical ranges described herein. In addition, when a numerical range described herein as "60 to 100," for example, means a range of "60 or more and 100 or less."

[0008] 1. Epoxy Resin Composition One aspect of the present invention provides an epoxy resin composition (hereinafter also referred to as "the composition of the present invention"). The composition of the present invention is an epoxy resin composition comprising silicone elastomer particles and silicone resin-coated silicone elastomer particles comprising a silicone resin coating that coats part or all of the surface of the silicone elastomer particles, wherein the silicone elastomer particles have a structure in which at least two silicon atoms are crosslinked by a silalkylene group having 2 to 20 carbon atoms, and the silicone resin coating comprises: i) R ３ SiO １／２ (R is a monovalent organic group) ２ SiO ２／２ (R is a monovalent organic group), and iii) a D siloxane unit represented by RSiO ３／２ (R is a monovalent organic group), and iv) SiO ４／２ and one or more silicone resins selected from silicone resins consisting of one or a combination of two or more selected from the group consisting of Q siloxane units represented by the formula: and wherein the epoxy resin composition does not contain a volatile solvent (excluding silicone resins consisting only of T siloxane units). The composition of one embodiment of the present invention may contain, in addition to the silicone resin-coated silicone elastomer particles (hereinafter also referred to as "component (A)"), an epoxy resin (B) (hereinafter also referred to as "component (B)"), a curing agent (C) (hereinafter also referred to as "component (C)"), and an inorganic filler (D) (hereinafter also referred to as "component (D)"). The composition of one embodiment of the present invention may also contain additives other than these components, as long as they do not impair the effects of the present invention.

[0009] The composition of the present invention does not contain a volatile solvent. Specifically, in a composition according to one embodiment of the present invention, the content of the volatile solvent may be less than 0.5 mass %, less than 0.1 mass %, less than 0.05 mass %, less than 0.01 mass %, or less than 0.001 mass %, based on 100 mass % of the total solids content of the composition. Such volatile solvents are not particularly limited, and include organic solvents such as alcohols such as methanol and ethanol; ketones such as acetone, methyl ethyl ketone, and methyl isobutyl ketone; esters such as ethyl acetate, butyl acetate, and cellosolve acetate; amides such as N,N-dimethylformamide; olefins such as hexane, heptane, and octane; and aromatic hydrocarbons such as toluene and xylene. Because the composition of the present invention does not contain these volatile solvents, it is particularly suitable for use as a sealant or the like in the manufacture of semiconductor devices, as described below.

[0010] In one embodiment of the present invention, the composition contains silicone resin-coated silicone elastomer particles that do not contain an ionic surfactant. Specifically, the surfactant content in this composition may be less than 0.5%, less than 0.1%, less than 0.05%, less than 0.01%, or less than 0.001% by mass, based on 100% by mass of the total solids content of the composition. While the epoxy resin composition according to one embodiment of the present invention is primarily used in semiconductor applications, when the ionic surfactant content is less than the above-mentioned lower limit, it is particularly suitable for use in electronic materials. This is because it is possible to prevent a decrease in electrical reliability due to ionic components in the surfactant. Such ionic surfactants include anionic surfactants, cationic surfactants, and amphoteric surfactants. More specific examples of these surfactants include those described in JP 2013-035758 A. Since the silicone resin-coated silicone elastomer particles according to one embodiment of the present invention do not contain a surfactant, they are particularly suitable for use as sealants in the manufacture of semiconductor devices, as described below. The type and amount of ionic surfactant in the particles can be identified using known techniques such as high-performance liquid chromatography. Each component constituting the composition of the present invention will be described in detail below.

[0011] <Component (A): Silicone Resin-Coated Silicone Elastomer Particles>

[0012] The silicone resin-coated silicone elastomer particles of one embodiment of the present invention are silicone resin-coated silicone elastomer particles comprising a silicone elastomer particle and a silicone resin coating that coats a part or all of the surface of the silicone elastomer particle. The silicone resin-coated silicone elastomer particles of one embodiment of the present invention further comprise a silicone elastomer particle having a structure in which at least two silicon atoms are crosslinked by a silalkylene group having 2 to 20 carbon atoms, and the silicone resin coating comprises: i) R ３ SiO １／２ (R is a monovalent organic group), ii) M siloxane units represented by R ２ SiO ２／２ (R is a monovalent organic group), and iii) a D siloxane unit represented by RSiO ３／２ (R is a monovalent organic group), and iv) SiO ４／２ and one or more silicone resins (excluding silicone resins consisting only of T siloxane units) selected from silicone resins consisting of one or a combination of two or more Q siloxane units represented by the following formula: Furthermore, in one embodiment of the present invention, the silicone resin has an epoxy group-containing hydrocarbon group in a siloxane unit selected from the siloxane units i) to iii) of the silicone resin.

[0013] [Silicone elastomer particles before coating] The silicone elastomer particles have a structure in which at least two silicon atoms are crosslinked by a silalkylene group having 2 to 20 carbon atoms. Such a silalkylene crosslinked structure is preferably formed between different siloxane molecules by the hydrosilylation reaction of an alkenyl group having 2 to 20 carbon atoms with a silicon-bonded hydrogen atom. In one embodiment of the present invention, the silalkylene group bridging the silicon atom with another silicon atom in the siloxane constituting the silicone elastomer particles is preferably a silalkylene group having 2 to 16 carbon atoms, more preferably 2 to 8 carbon atoms, and particularly preferably an ethylene group, propylene group, butylene group, or hexylene group.

[0014] The silicone elastomer particles according to one embodiment of the present invention are not particularly limited in terms of the average primary particle size before being coated with a silicone resin, but preferably have an average primary particle size of 0.1 to 99 μm as measured by a laser diffraction scattering method. Such silicone elastomer particles can be further coated on part or all of their surfaces with a silicone resin and further classified as necessary to finally give silicone resin-coated silicone elastomer particles having an average primary particle size of 0.1 to 100 μm as measured by a laser diffraction scattering method. Needless to say, after coating, the average primary particle size of the particles increases compared to the silicone elastomer particles before coating.

[0015] The shape of the silicone elastomer particles according to one aspect of the present invention can be, for example, spherical, spherical, ellipsoidal, or irregular, and is particularly preferably spherical or spherical.In one aspect of the present invention, by emulsifying hydrolyzable silanes together with a crosslinking reactive silicone raw material, an aqueous suspension containing spherical silicone elastomer particles coated with silicone resin can be obtained in a single reaction vessel.In addition, spherical silicone resin-coated silicone elastomer particles can be directly produced by drying the aqueous suspension using a vacuum dryer, a hot air circulation oven, or a spray dryer.Therefore, it is not necessarily necessary to separately produce uncoated silicone elastomer particles and coat their surfaces.

[0016] The silicone elastomer particles according to one embodiment of the present invention are elastomer particles having elasticity from the viewpoint of technical effects such as stress relaxation when blended into a material to which they are added, such as an epoxy resin. Preferably, when the crosslinkable composition for forming silicone elastomer particles before the silicone elastomer particles is cured into a sheet, the cured product has a JIS-A hardness of 80 or less and a JIS-E hardness of 1 or more. The JIS-A hardness is measured using a JIS-A hardness tester as specified in JIS K6253, and the JIS-E hardness is measured using a JIS-E hardness tester as specified in JIS K6253. When the JIS-A hardness and JIS-E hardness of the rubber sheet obtained by curing the crosslinkable composition for forming silicone elastomer particles into a sheet are measured within the above-mentioned ranges, the resulting silicone elastomer particles are likely to have sufficiently reduced agglomeration and are therefore rich in fluidity, dispersibility, silky feel, smoothness, and softness. In particular, from the standpoint of designing soft silicone elastomer particles, the JIS-A hardness of the cured product may be 45 or less, and the JIS-E hardness may be 1 or more. Furthermore, by setting the JIS-A hardness and JIS-E hardness within the above ranges, stress relaxation properties can be further improved when blended with various materials such as epoxy resins, and excellent handling and workability can be achieved after coating with the silicone resin. The JIS-A hardness, which corresponds to the upper limit of the hardness of the elastomer particles, is 80 or less, preferably 50 or less, more preferably 40 or less, and even more preferably 30 or less. Similarly, the JIS-E hardness, which corresponds to the lower limit of the hardness of the elastomer particles, is preferably 1 or more, and, from a practical standpoint, more preferably 2 or more or 3 or more.

[0017] In one embodiment of the present invention, the upper limit of the hardness of the cured product is specified in JIS-A hardness and the lower limit in JIS-E hardness because when the hardness of the cured product of the composition is in a relatively high range, the level of hardness can be easily expressed by JIS-A hardness, and when the hardness of the cured product is in a relatively low range, the level of hardness can be easily expressed by JIS-E hardness. In addition, when the crosslinkable composition for forming silicone elastomer particles is cured into a sheet, the cured product may have a JIS-E hardness of 50 when the JIS-A hardness is 25, and a JIS-E hardness of 37 when the JIS-A hardness is 8, and a JIS-E hardness of 23.

[0018] The silicone elastomer particles according to one embodiment of the present invention may further have a silicon-bonded hydrogen atom (hereinafter also referred to as silicon-bonded hydrogen) content per unit mass of 300 ppm or less. The silicon-bonded hydrogen content is preferably 250 ppm or less, and even more preferably 200 ppm or less. It is further preferably 150 ppm or less, more preferably 100 ppm or less, even more preferably 50 ppm or less, and even more preferably 20 ppm or less. If the silicone elastomer particles according to one embodiment of the present invention have a high content of silicon-bonded hydrogen, crosslinking reactions with reactive functional groups remaining in other silicone elastomer particles may proceed, resulting in aggregation of the silicone elastomer particles or silicone resin-coated silicone elastomer particles over time. Furthermore, in one embodiment of the present invention, reducing the silicon-bonded hydrogen in the silicone elastomer particles can adequately suppress the generation of hydrogen gas that may occur during long-term storage of these particles.

[0019] A typical method for measuring silicon-bonded hydrogen in silicone elastomer particles is to contact the particles with an alkali and then use gas chromatography (headspace method). For example, an ethanol solution of 40% potassium hydroxide in an amount equal to the unit mass of the silicone elastomer particles is added, the mixture is allowed to stand for one hour, and the hydrogen gas evolved up to the end of the reaction is collected. Then, the amount of the collected hydrogen is measured and quantified using headspace gas chromatography (TCD is preferred as the detector), which makes it possible to identify the content (ppm) of silicon-bonded hydrogen per unit mass.

[0020] [Crosslinkable Composition for Forming Silicone Elastomer Particles] The silicone elastomer particles have a structure in which at least two silicon atoms in a molecule are crosslinked by a silalkylene group having 2 to 20 carbon atoms, and can be obtained by curing, through a hydrosilylation reaction, a crosslinkable composition containing the following components: (a) an organopolysiloxane having at least two alkenyl groups having 2 to 20 carbon atoms in each molecule, (b) an organohydrogenpolysiloxane having at least two hydrogen atoms bonded to silicon atoms in each molecule, and (c) a hydrosilylation reaction catalyst.

[0021] Component (a) is an organopolysiloxane having at least two alkenyl groups having 2 to 20 carbon atoms per molecule. Its structure is not particularly limited and may be one or more structures selected from linear, cyclic, network, and partially branched linear structures. Linear organopolysiloxanes are particularly preferred as component (a). The viscosity of component (a) is preferably within a range that allows the crosslinkable composition to be dispersed in water or dispersible using a spray dryer or the like. Specifically, the viscosity at 25°C is preferably within a range of 1 to 100,000 mPa·s, and particularly preferably within a range of 1 to 10,000 mPa·s.

[0022] From the viewpoint of dispersibility of the silicone elastomer particles, component (a) is a compound represented by the formula: -(CH ３ ) ２Preferably, the organopolysiloxane is a linear organopolysiloxane in which the content of dimethylsiloxane units represented by SiO- is 90 mol% or more of all siloxane units other than siloxane units at the molecular terminals. Similarly, from the standpoint of improving contact failures in electronic components and the like equipped with resin components after blending the resulting silicone elastomer particles, it is also preferable to remove in advance from component (a) any cyclic or linear organopolysiloxanes with a low degree of polymerization (degree of polymerization 3 to 20) other than intentionally added low polymers by solvent washing, stripping, thin-film distillation, or the like. Furthermore, component (a) may be used alone or in combination with two or more organohydrogenpolysiloxanes.

[0023] Examples of alkenyl groups having 2 to 20 carbon atoms in component (a) include vinyl, allyl, butenyl, pentenyl, hexenyl, heptenyl, octenyl, nonenyl, decenyl, undecenyl, dodecenyl, tridecenyl, tetradecenyl, pentadecenyl, hexadecenyl, heptadecenyl, octadecenyl, nonadecenyl, and icocenyl groups. From the standpoints of reactivity and cohesion, the alkenyl group preferably has 2 to 16 carbon atoms, or 2 to 8 carbon atoms, with vinyl or hexenyl being particularly preferred. Furthermore, the alkenyl groups are preferably located at the molecular chain terminals of the organopolysiloxane, but may also be located in side chains or both. Examples of groups bonded to silicon atoms other than alkenyl groups include unsubstituted or substituted monovalent hydrocarbon groups such as alkyl groups such as methyl, ethyl, propyl, and butyl; cycloalkyl groups such as cyclopentyl and cyclohexyl; aryl groups such as phenyl, tolyl, and xylyl; aralkyl groups such as benzyl, phenethyl, and 3-phenylpropyl; and halogenated alkyl groups such as 3-chloropropyl and 3,3,3-trifluoropropyl.

[0024] Preferably, component (a) is a linear organopolysiloxane represented by the following chemical formula (1).

[0025] In formula (1), R １１are each independently an unsubstituted or halogen-substituted alkyl group having 1 to 20 carbon atoms (e.g., methyl group), an aryl group having 6 to 22 carbon atoms (e.g., phenyl group), or a hydroxyl group, and are preferably a methyl group or a phenyl group industrially. ａ is an alkenyl group having 2 to 20 carbon atoms, and is particularly preferably a vinyl group or a hexenyl group. １１ or R ａ where m is a number of 0 or more, and n is a number of 1 or more. Here, m, n, and R represent the vinyl (CH ２ The number is such that the content of (═CH—) moieties is 0.02 to 5.0 mass %, preferably 0.03 to 3.0 mass %, and the viscosity of component (a) is 1 to 10,000 mPa·s at 25° C.

[0026] Component (a) may be an organopolysiloxane represented by the following structural formula (2) having hexenyl groups at both molecular chain terminals and in side chains, or may be an organopolysiloxane in which some or all of the hexenyl groups in structural formula (2) are vinyl groups. (In formula (2), m1 is a number of 0 or more, n1 is a positive number, and m1 is a hexenyl group (-(CH ２ ) ４ CH=CH ２ ) in vinyl (CH ２ m1+n1 is a number such that the content of (═CH-) moieties falls within a range of 0.5 to 3.0 mass%, more preferably 1.0 to 2.0 mass%. Furthermore, m1+n1 is a number such that the viscosity of the organopolysiloxane represented by formula (2) at 25°C is 20 mPa·s or more, more preferably 100 to 500 mPa·s.

[0027] In addition, component (a) is (R ａ R １１ ２ SiO) ４ The organopolysiloxane may be a branched organopolysiloxane having an alkenyl group at the molecular chain terminal, represented by the formula: ａis an alkenyl group having 2 to 20 carbon atoms, and R １１ are each independently an unsubstituted or halogen-substituted alkyl group having 1 to 20 carbon atoms (e.g., methyl group), an aryl group having 6 to 22 carbon atoms (e.g., phenyl group), or a hydroxyl group. More specifically, ２ SiO) ４ Si, and (HexMe ２ SiO) ４ The organopolysiloxane may be a branched organopolysiloxane represented by Si 1 , where Vi represents a vinyl group, Me represents a methyl group, and Hex represents a hexenyl group.

[0028] Examples of component (a) include linear, cyclic, or branched organopolysiloxanes represented by the following formula, in which some or all of the vinyl groups may be hexenyl groups. (In the above formula, b and c are integers from 0 to 3 such that b+c=3, d is a positive number, e is 0 or a positive number, and 2b+e≧2. R １１ is the same as the above formula (1). (In the above formula, f is a positive number of 2 or more, g is 0 or a positive integer, and f+g is 4 to 8. R １１ is the same as the above formula (1). (In the above formula, h is 1, 2, or 3, i is 0, 1, or 2, and h+i=3; j, k, and L are positive numbers. R １１ is the same as the formula (1) above.) However, b and e in the formula representing the linear organopolysiloxane, f in the formula representing the cyclic organopolysiloxane, and h in the formula representing the branched organopolysiloxane represent vinyl (CH ２ The values ​​of b, e, f, and h in each formula are numbers that result in the content of (═CH—) moieties being in the range of 0.5 to 3.0 mass%, and more preferably in the range of 1.0 to 2.0 mass%. Furthermore, b, e, f, and h in each formula are numbers that result in the viscosity of the organopolysiloxane represented by each formula being 20 mPa s or more at 25° C., and are more preferably numbers that result in the viscosity being 100 to 500 mPa s.

[0029] Component (b) is an organohydrogenpolysiloxane having at least two silicon-bonded hydrogen atoms (hereinafter also referred to as silicon-bonded hydrogen atoms) per molecule, and serves as a crosslinking agent for component (a). It more preferably has at least three silicon-bonded hydrogen atoms per molecule, and the bonding positions of the hydrogen atoms within the molecule are not particularly limited. From the standpoint of improving contact failures in electronic components and other devices equipped with resin components after blending the resulting silicone elastomer particles, it is also preferable to remove in advance, with the exception of intentionally added low polymers, cyclic or linear organopolysiloxanes with low degrees of polymerization (3 to 20) from component (b) by solvent washing, stripping, thin-film distillation, or the like. Furthermore, component (b) may be used alone, or two or more types of organohydrogenpolysiloxanes may be used.

[0030] Examples of organic groups other than hydrogen atoms that are bonded to silicon atoms contained in component (b) include alkyl groups such as methyl, ethyl, propyl, butyl, and octyl groups, and aryl groups such as phenyl groups, with methyl groups being preferred.Furthermore, examples of the molecular structure of the organohydrogenpolysiloxane of component (b) include linear, branched, and branched cyclic structures, or a combination of one or more of these.Note that the number of silicon-bonded hydrogen atoms in one molecule is the average value of all molecules.

[0031] Examples of component (b) include linear, cyclic, or branched polyorganohydrogensiloxanes represented by the following formula: (wherein m' is 0 or 1, n2 is 2 or 3, and m'+n'=3, p is 0 or a positive number, q is 0 or a positive number, and 2m'+q≧2. R １１ is the same as the above formula (1). (wherein r is a positive number of 2 or more, s is 0 or a positive number, and r+s is 4 to 8. R １１ is the same as the above formula (1). (wherein t is 1, 2, or 3, u is 0, 1, or 2, and (t+u)=3; v, w, and x are positive numbers. R １１is the same as the above formula (1). Component (b) is (HSiO ３ / ２ ) units or (R １１ SiO ３ / ２ T-branched polyorganohydrogensiloxane (R １１ is the same as the above formula (1).

[0032] The viscosity of component (b) at 25°C is 1 to 1,000 mPa·s, preferably 5 to 500 mPa·s. When the viscosity of component (b) at 25°C is 1 mPa·s or more, volatilization of component (b) from the crosslinkable composition containing it can be effectively prevented. Furthermore, when the viscosity of component (b) at 25°C is 1,000 mPa·s or less, the curing time of the crosslinkable composition containing such component (b) can be prevented from being too long and the occurrence of curing defects can be suppressed. Examples of such component (b) include, but are not limited to, a dimethylsiloxane-methylhydrogensiloxane copolymer both ends of which are capped with trimethylsiloxy groups, a dimethylsiloxane-methylhydrogensiloxane copolymer both ends of which are capped with dimethylhydrogensiloxy groups, a dimethylpolysiloxane both ends of which are capped with dimethylhydrogensiloxy groups, a methylhydrogenpolysiloxane both ends of which are capped with trimethylsiloxy groups, a cyclic methylhydrogenpolysiloxane, a cyclic methylhydrogensiloxane-dimethylsiloxane copolymer, and a T-branched polymethylhydrogensiloxane.

[0033] Here, the molar ratio (=reaction ratio in the hydrosilylation reaction) of the content of alkenyl groups (Alk (mol)) in component (a) to the content of silicon-bonded hydrogen atoms (H (mol)) in component (b), H / Alk, is preferably in the range of 0.5 to 1.5. The lower limit of H / Alk is preferably 0.60 or more, and the upper limit is 1.50 or less, and more preferably 1.30 or less. If the upper limit of H / Alk exceeds the above value, unreacted silicon-bonded hydrogen atoms are likely to remain after the reaction. Because these are curing reactive groups, if a large amount remains in the particles, they can cause crosslinking reactions between particles over time, resulting in aggregation and poor dispersion of the resulting silicone elastomer particles or silicone resin-coated silicone elastomer particles. Furthermore, if reactive hydrogen atoms remain, they can cause hydrogen gas generation over time. Particularly preferably, when the H / Alk value is in the range of 0.6 to 1.30, the curing reactive groups are completely consumed, the crosslinking reaction is terminated, and aggregation between particles over time can be effectively suppressed.

[0034] Component (c) is a hydrosilylation catalyst that promotes the addition reaction (hydrosilylation reaction) between silicon-bonded alkenyl groups present in the crosslinkable composition and silicon-bonded hydrogen atoms. Preferred hydrosilylation catalysts are those containing platinum-based metals, and specific examples include chloroplatinic acid, alcohol-modified chloroplatinic acid, olefin complexes of chloroplatinic acid, complexes of chloroplatinic acid and ketones, complexes of chloroplatinic acid and vinylsiloxanes, platinum tetrachloride, platinum fine powder, solid platinum supported on an alumina or silica carrier, platinum black, olefin complexes of platinum, alkenylsiloxane complexes of platinum, carbonyl complexes of platinum, and platinum catalysts containing these platinum catalysts in powders of thermoplastic organic resins such as methyl methacrylate resins, polycarbonate resins, polystyrene resins, and silicone resins. In particular, platinum alkenylsiloxane complexes such as a complex of chloroplatinic acid and divinyltetramethyldisiloxane, a complex of chloroplatinic acid and tetramethyltetravinylcyclotetrasiloxane, a platinum divinyltetramethyldisiloxane complex, and a platinum tetramethyltetravinylcyclotetrasiloxane complex are preferably used. Note that non-platinum metal catalysts such as iron, ruthenium, and iron / cobalt may also be used as catalysts for promoting the hydrosilylation reaction.

[0035] The amount of component (c) added to the crosslinkable composition may be any catalytic amount, and typically, the amount is preferably such that the amount of platinum-based metal contained in component (c) is in the range of 1 to 1,000 ppm, more preferably in the range of 5 to 500 ppm, relative to the total mass of the crosslinkable composition. The platinum content in the silicone elastomer particles may be reduced by washing the silicone elastomer particles with an aqueous solution (preferably at 30°C to 99°C) of one or more surfactants, such as polyoxyethylene alkyl ether or diethylhexyl sodium sulfosuccinate.

[0036] The timing of adding component (c) to the crosslinkable composition can be selected depending on the method for forming the silicone elastomer particles, and it may be added to the composition in advance, or component (a) or component (b) may be supplied from different spray lines and added to either one of them and mixed during spraying. Similarly, when the silicone elastomer particles are formed via an aqueous suspension formed by emulsifying them in water, component (c) may be added to the crosslinkable composition in advance, or an emulsion containing component (c) may be added separately to the water.

[0037] The crosslinkable composition may contain a cure retarder, typically a hydrosilylation reaction inhibitor. Examples of such cure retarders include acetylene compounds, enyne compounds, organic nitrogen compounds, organic phosphorus compounds, and oxime compounds. Specific compounds include alkyne alcohols such as 2-methyl-3-butyn-2-ol, 3,5-dimethyl-1-hexyn-3-ol, 3-methyl-1-pentyn-3-ol, 2-phenyl-3-butyn-2-ol, and 1-ethynyl-1-cyclohexanol (ETCH); 3-methyl-3-trimethylsiloxy-1-butyne, 3-methyl-3-trimethylsiloxy-1-pentyne, 3,5-dimethyl-3-trimethylsiloxy-1-hexyne, and 3-methyl-3-penten-1-yne. and 3,5-dimethyl-3-hexen-1-yne; and alkenylsiloxanes such as 1-ethynyl-1-trimethylsiloxycyclohexane, bis(2,2-dimethyl-3-butynoxy)dimethylsilane, methyl(tris(1,1-dimethyl-2-propynyloxy))silane, 1,3,5,7-tetramethyl-1,3,5,7-tetravinylcyclotetrasiloxane, and 1,3,5,7-tetramethyl-1,3,5,7-tetrahexenylcyclotetrasiloxane. The amount added is within a range of 0.001 to 5 parts by mass per 100 parts by mass of component (a), but can be appropriately determined depending on the type of cure retarder used, the properties and amount of the hydrosilylation reaction catalyst used, and the like.

[0038] The crosslinkable composition may contain components other than those described above, provided that the technical effects of the present invention are not impaired. For example, the crosslinkable composition may contain 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; ketones such as acetone, methyl ethyl ketone, and methyl isobutyl ketone; organic solvents such as polydimethylsiloxane and polydimethyldiphenylsiloxane. The crosslinkable composition may contain a non-reactive organopolysiloxane (including a linear or cyclic organopolysiloxane having a low viscosity of about 0.5 to 10 mPa·s at 25°C); an antioxidant such as a phenol, quinone, amine, phosphorus, phosphite, sulfur, or thioether; a light stabilizer such as a triazole or benzophenone; a flame retardant such as a phosphate ester, halogen, phosphorus, or antimony; one or more antistatic agents such as a cationic surfactant, anionic surfactant, or nonionic surfactant; a dye; a pigment, etc. The crosslinkable composition for forming silicone elastomer particles may or may not contain a component such as a silane for forming a silicone resin coating.

[0039] [Coating with Silicone Resin] The silicone resin-coated silicone elastomer particles of one embodiment of the present invention contain a silicone resin coating that coats a part or the whole of the surface of the silicone elastomer particles. Specifically, the silicone resin coating comprises: i) R ３ SiO １／２ (R is a monovalent organic group) ２ SiO ２／２ (R is a monovalent organic group), and iii) a D siloxane unit represented by RSiO ３／２ (R is a monovalent organic group), and iv) SiO ４／２and one or more silicone resins (excluding silicone resins consisting only of T siloxane units) selected from silicone resins consisting of one or a combination of two or more selected from the group consisting of Q siloxane units represented by:

[0023] Furthermore, in the silicone resin-coated silicone elastomer particles of one embodiment of the present invention, the silicone resin has an epoxy group-containing hydrocarbon group in a siloxane unit selected from the siloxane units i) to iii) of the silicone resin.

[0040] In one aspect of the present invention, the silicone resin coating contains the above-mentioned silicone resin, which contributes to stress relaxation of the material to which it is added while maintaining dispersibility in the material to which it is added, and also provides degradation resistance. More specifically, by coating part or all of the surface of the silicone elastomer particles with the silicone resin coating, secondary aggregation between particles is effectively suppressed, thereby improving dispersibility, handling, and compounding stability. In one aspect of the present invention, the silicone resin contained in the silicone resin coating does not include a silicone resin consisting only of T siloxane units. However, when silicone elastomer particles are coated with a silicone resin consisting only of T siloxane units, they tend to be prone to gelation during production or aggregation after production. Furthermore, when silane undergoes a condensation reaction on the surface of the silicone elastomer particles, the condensation reaction is difficult to control, or the condensation reaction tends to result in problems such as solidification. Furthermore, silicone elastomer particles containing a silicone resin consisting of epoxy groups and T siloxane units tend to have difficulty in fully exhibiting the properties of silicone rubber particles due to the T siloxane units, and may be insufficient in improving thermal stress. Furthermore, when the silicone resin contains an epoxy group-containing hydrocarbon group in a siloxane unit selected from siloxane units i) to iii), when the silicone resin-coated silicone elastomer particles are mixed with a material to which they are to be added, the epoxy groups of the silicone resin-coated silicone elastomer particles serve as reaction sites with the material, improving adhesion to the resin. This prevents the particle-resin interface from peeling when the added resin is subjected to external or internal impact or strain, allowing the impact or strain to be absorbed within the added elastomer particles. Even when the powder particles break, the internal stress is absorbed, contributing to crack resistance and toughness. Furthermore, the improved adhesion effectively reduces molding shrinkage, the thermal expansion coefficient, or the elastic modulus, contributing to stress relaxation in the material. Furthermore, the improved adhesion also imparts resistance to deterioration, making the additive less likely to affect the material's degradation over long-term use.

[0041] In one embodiment of the present invention, the amount of silicone resin other than the above is preferably less than 5% by mass, more preferably less than 3% by mass, and even more preferably less than 1% by mass, based on the total amount of silicone resin used in the silicone resin coating. Most preferably, no components that provide other silicone resins are intentionally added, and it is most preferred that no other silicone resins are present on the surface of the silicone elastomer particles. Other silicone resins (e.g., RSiO ３／２

[0033] If the silicone resin-coated silicone elastomer particles contain a silsesquioxane resin represented by the formula (2), the resulting silicone resin-coated silicone elastomer particles may be prone to scattering or adhesion to containers during handling, or the problem of aggregation may not be sufficiently resolved, resulting in poor handling and workability and work efficiency. Furthermore, the silicone resin coating preferably contains less than 5% by mass of resins other than the silicone resin, based on the entire silicone resin coating, more preferably less than 3% by mass, and particularly preferably less than 1% by mass. Most preferably, no resins other than the silicone resin are intentionally added, and it is most preferred that no other silicone resins are contained on the surfaces of the silicone elastomer particles.

[0042] In one embodiment of the present invention, examples of the silicone resin contained in the silicone resin coating include a silicone resin composed of M siloxane units and T siloxane units, a silicone resin composed of M siloxane units and Q siloxane units, a silicone resin composed of D siloxane units and T siloxane units, a silicone resin composed of D siloxane units and Q siloxane units, a silicone resin composed of T siloxane units and Q siloxane units, a silicone resin composed of Q siloxane units, a silicone resin composed of M siloxane units, D siloxane units and T siloxane units, a silicone resin composed of M siloxane units, T siloxane units and Q siloxane units, a silicone resin composed of M siloxane units and Q siloxane units, a silicone resin composed of D siloxane units, T siloxane units and Q siloxane units, and a silicone resin composed of M siloxane units, D siloxane units, T siloxane units and Q siloxane units. Among these, in one embodiment of the present invention, DQ silicone resins consisting of D siloxane units and Q siloxane units, DT silicone resins consisting of D siloxane units and T siloxane units, TQ silicone resins consisting of T siloxane units and Q siloxane units, and DTQ silicone resins consisting of D siloxane units, T siloxane units, and Q siloxane units are preferred. This is because the silanols generated by hydrolysis of the Q units form a three-dimensional structure, increasing the reaction efficiency with the silanols of the D units and T units, thereby allowing for efficient introduction of functional groups, reducing unreacted silane remaining in water, and suppressing aggregation. From the same perspective, DQ silicone resins consisting of D siloxane units and Q siloxane units are more preferred.

[0043] In one embodiment of the present invention, the siloxane unit having an epoxy group-containing hydrocarbon group in the siloxane unit is selected from i) to iii) the M, D, and T siloxane units (in other words, the monovalent organic group contained in the M, D, and T siloxane units is the epoxy group-containing hydrocarbon group). If the silicone resin is a DQ silicone resin, the epoxy group-containing hydrocarbon group is contained in the D siloxane unit. If the silicone resin is a TQ silicone resin, the epoxy group-containing hydrocarbon group may be contained in the T siloxane unit, and if the silicone resin is a DTQ silicone resin, the epoxy group-containing hydrocarbon group may be contained in the D or T siloxane unit.

[0044] In one embodiment of the present invention, the epoxy group-containing organic group is not particularly limited, and examples thereof include an epoxy group, a glycidyl ether group, a glycidyl ester group, a glycidylamino group, and groups in which these groups are bonded to a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms. More specifically, examples of the epoxy group-containing organic group include a 3-glycidoxypropyl group and an alicyclic epoxy group such as a 2-(3,4-epoxycyclohexyl)ethyl group.

[0045] In one embodiment of the present invention, the epoxy equivalent of the silicone resin-coated silicone elastomer particles is not particularly limited, but from the viewpoint of compatibility with and adhesion to the material to which they are added, the epoxy equivalent of the particle surface is preferably 1,000 to 100,000 g / mol, and more preferably 2,000 to 50,000 g / mol. The epoxy equivalent is determined using potentiometric titration.

[0046] In one embodiment of the present invention, the silicone resin coating is preferably １ ２ SiO ２／２ (R １ are independently a D siloxane unit represented by an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, an alkyl group having 1 to 20 carbon atoms and an epoxy group, or an aryl group having 6 to 20 carbon atoms and an epoxy group), and SiO ４／２ and a DQ silicone resin comprising a Q siloxane unit represented by the formula: １ ２ SiO２／２ (R １ are independently a D siloxane unit represented by an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, an alkyl group having 1 to 20 carbon atoms and an epoxy group, or an aryl group having 6 to 20 carbon atoms and an epoxy group; and R １ ３ SiO １／２ (R １ is the same as above), and SiO ４／２ and Q siloxane units represented by the formula: １ ２ SiO ２／２ (R １ are independently a D siloxane unit represented by an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, an alkyl group having 1 to 20 carbon atoms and an epoxy group, or an aryl group having 6 to 20 carbon atoms and an epoxy group), and SiO ４／２ and a DQ silicone resin comprising a Q siloxane unit represented by the formula:

[0047] Furthermore, in the DQ silicone resin, the ratio of the amount of substance of D siloxane units to Q siloxane units is more preferably within the range of 8:2 to 0.8:9.2. Furthermore, in the DQ silicone resin, the ratio of the amount of substance of D siloxane units to Q siloxane units is even more preferably within the range of 7:3 to 5:5. Furthermore, in the DTQ silicone resin, the ratio of the amount of substance of D siloxane units to the total amount of substance of T siloxane units and Q siloxane units is more preferably within the range of 8:2 to 0.8:9.2, and even more preferably within the range of 7:3 to 5:5. Furthermore, in the R １ ２ SiO ２／２ The D siloxane unit represented by one R １ is an alkyl group or an aryl group having an epoxy group, the other R １ is more preferably an alkyl group or an aryl group that does not have an epoxy group. １ ３ SiO ２／２ The T siloxane unit represented by１ is an alkyl group or aryl group having an epoxy group, other R １ is more preferably an alkyl group or aryl group that does not have an epoxy group. The D siloxane units that constitute the silicone resin form two siloxane bonds to form a linear siloxane bond, while the Q siloxane units form four siloxane bonds to form a highly branched network or reticulated siloxane bond. Therefore, when the amount of D siloxane units is within the above range, a large amount of a moderately flexible polydiorganosiloxane structure is contained in the silicone resin, which improves the smoothness, flexibility, and conformability of the silicone resin coating on the surface of the silicone elastomer particles and particularly effectively suppresses the formation of secondary aggregate particles.

[0048] The above silicone resin can be obtained by subjecting a silane compound or its condensation product that provides these siloxane units to a hydrolysis reaction or a dehydration / dealcoholization condensation reaction on the surface of silicone elastomer particles.

[0049] More specifically, the silicone resin is R ２ Si(OA) ２ (wherein R is independently a monovalent organic group, and A is independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or a phenyl group) or a hydrolyzable silane or a condensation reaction product thereof, RSi(OA) ３ (wherein R is a monovalent organic group, and A is independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or a phenyl group) or a hydrolyzable silane or a condensation reaction product thereof, and Si(OA) ４ (wherein A independently represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or a phenyl group), or a condensation reaction product thereof. Here, the condensation reaction product of the silane compound used for coating is preferably an oligomer or a mixture of oligomers having an average of 20-mer, 2-10-mer, or 2-8-mer, and may be, for example, tetraethoxysilane or its condensation reaction product, ethyl silicate, or a mixture thereof.

[0050] In the formula, R represents a monovalent organic group, and examples thereof include alkyl groups such as methyl, ethyl, propyl, and butyl; cycloalkyl groups such as cyclopentyl and cyclohexyl; alkenyl groups such as vinyl, allyl, butenyl, pentenyl, hexenyl, heptenyl, octenyl, nonenyl, and decenyl; aryl groups such as phenyl, tolyl, and xylyl; aralkyl groups such as benzyl, phenethyl, and 3-phenylpropyl; halogenated alkyl groups such as 3-chloropropyl and 3,3,3-trifluoropropyl; and monovalent hydrocarbon groups such as acryloxy, methacryloxy, epoxy, glycidyl ether, glycidyl ester, and glycidylamino groups, as well as groups formed by bonding these groups to a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms. Industrially, it is preferable to use hydrolyzable silanes in which R represents a methyl or phenyl group. In the hydrolyzable silane, for example, all of the R's may be methyl groups, or they may each be a different substituent. The silicone resin may contain the monovalent organic group exemplified above in the siloxane unit.

[0051] In the formula, "OA" is a hydrolyzable hydroxyl group, alkoxy group, or phenoxy group, and each A is independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or a phenyl group. From the standpoint of condensation reactivity to give a silicone resin, OA is preferably a hydroxyl group, or an alkoxy group having 1 to 4 carbon atoms, such as a methoxy group, ethoxy group, propoxy group, or butoxy group, and in the above hydrolyzable silane, OA is particularly preferably an alkoxy group having 1 to 4 carbon atoms.

[0052] In one embodiment of the present invention, the silicone resin coating preferably contains a silicone resin composed of a condensation product of one or a combination of two or more hydrolyzable silanes selected from triorganoalkoxysilanes, diorganodialkoxysilanes, organotrialkoxysilanes, and tetraalkoxysilanes (excluding condensation products of tetraalkoxysilanes alone). In particular, some or all of the tetraalkoxysilanes may be condensation products (oligomers / oligomer mixtures), or the condensation product forming the DQ silicone resin may be a condensation product of a combination of some or all of the condensation products (oligomers / oligomer mixtures) of tetraalkoxysilanes and diorganodialkoxysilanes. Furthermore, when the condensation product contains any of triorganoalkoxysilanes, diorganodialkoxysilanes, and organotrialkoxysilanes, at least some of the silanes contained in the triorganoalkoxysilanes, diorganodialkoxysilanes, and organotrialkoxysilanes have epoxy group-containing hydrocarbon groups. In one embodiment of the present invention, the silicone resin coating comprises a DQ silicone resin formed from a condensation reaction product of a diorganodialkoxysilane and a tetraalkoxysilane, wherein at least a portion of the silane in the diorganodialkoxysilane preferably has an epoxy group-containing hydrocarbon group. In this case, the molar ratio of the D units derived from the diorganodialkoxysilane to the Q units derived from the tetraalkoxysilane is preferably within a range of 8:2 to 0.8:9.2, and particularly preferably within a range of 7:3 to 5:5. A particularly preferred example is a DQ silicone resin formed from a condensation reaction product of dimethyldimethoxysilane and tetraethoxysilane.

[0053] The coating of the surface of silicone elastomer particles using the condensation reaction product of hydrolyzable silane is not particularly limited, but may be obtained by hydrolyzing and condensing the hydrolyzable silane in water in the presence of the silicone elastomer particles and an alkaline substance, thereby coating the surface of the silicone elastomer particles with a silicone resin.The timing of adding the alkaline substance or acidic substance is arbitrary, but from the viewpoint of uniformly coating the surface of the silicone elastomer particles, it is preferable to emulsify the crosslinkable reactive silicone raw material and the hydrolyzable silane that form the silicone elastomer particles in water to form an emulsion, and then add the alkaline substance to the emulsion after or together with the hydrosilylation reaction of the crosslinkable reactive silicone.

[0054] Preferably, the hydrolyzable silane is added to the crosslinkable reactive silicone raw material that forms the silicone elastomer particles, and the mixture is emulsified in water while being uniformly mixed using a conventional agitator such as a propeller blade or flat blade.

[0055] In the above-described emulsified state, from the viewpoint of uniformly coating the surfaces of the silicone elastomer particles, the temperature of the aqueous reaction solution containing the silicone elastomer particles and the alkaline substance is preferably 5 to 60°C, more preferably 10 to 60°C. Within this temperature range, the hydrolysis and condensation reaction of the hydrolyzable silane proceeds gently on the surfaces of the silicone elastomer particles, resulting in a uniform coating with the silicone resin. The reaction solution is continued to be stirred until the desired coating reaction with the silicone resin is completed, and may be stirred at a temperature higher than the above temperature (for example, under heating to 40°C or higher) to complete the reaction.

[0056] The alkaline or acidic substance acts as a catalyst for the hydrolysis and condensation reaction of the hydrolyzable silane. In one embodiment of the present invention, an alkaline substance is preferred, and one type may be used alone, or two or more types may be used in combination. The alkaline substance may be added as is or as an alkaline aqueous solution. The amount of alkaline substance added is an amount such that, for an aqueous reaction liquid containing silicone elastomer particles and an alkaline substance, the pH of the aqueous dispersion containing the alkaline substance falls within the range of 10.0 to 13.0, preferably 10.5 to 12.5. If the pH is outside this range, the silicone elastomer particles may not be sufficiently coated with the silicone resin composed of the M, D, T, and Q siloxane units derived from each hydrolyzable silane.

[0057] The alkaline substance is not particularly limited, and examples thereof include alkali metal hydroxides such as potassium hydroxide, sodium hydroxide, and lithium hydroxide; alkaline earth metal hydroxides such as calcium hydroxide and barium hydroxide; alkali metal carbonates such as potassium carbonate and sodium carbonate; ammonia; tetraalkylammonium hydroxides such as tetramethylammonium hydroxide and tetraethylammonium hydroxide; and amines such as monomethylamine, monoethylamine, monopropylamine, monobutylamine, monopentylamine, dimethylamine, diethylamine, trimethylamine, triethanolamine, and ethylenediamine. Among these, ammonia is the most suitable because it can be easily removed from the resulting silicone microparticle powder by volatilization. As the ammonia, commercially available aqueous ammonia solutions can be used.

[0058] After the hydrolysis and condensation reaction, the silicone resin-coated silicone elastomer particles of one embodiment of the present invention obtained may be used as an aqueous dispersion (aqueous suspension) as is, but preferably, the silicone resin-coated silicone elastomer particles are isolated by removing water from the reaction solution.Methods for removing water from the aqueous dispersion include, for example, drying using a vacuum dryer, a hot air circulation oven, or a spray dryer.In addition, as a pretreatment for this operation, the dispersion may be concentrated by methods such as thermal dehydration, filtration separation, centrifugation, and decantation, and if necessary, the dispersion may be washed with water.

[0059] In the silicone resin-coated silicone elastomer particles according to one embodiment of the present invention, the amount of silicone resin coating is not particularly limited. The amount of silicone resin coating is preferably in the range of 5.0 to 40.0 parts by mass, and more preferably in the range of 5.0 to 30.0 parts by mass, per 100 parts by mass of the silicone elastomer particles. By ensuring that the coating amount is equal to or greater than the lower limit, the silicone elastomer particles can be effectively coated with the silicone resin coating, and technical effects such as uniform dispersion in materials such as epoxy resins can be effectively achieved. Furthermore, if the coating amount is too large, the SiO in the silicone resin, in particular, can be reduced. ４／２ Q siloxane units represented by the formula: and RSiO ３／２The hard physical properties derived from the T siloxane units represented by the formula (2) are strongly reflected, which may impair the elasticity and elastic properties derived from the silicone elastomer particles. Furthermore, the coated powder may aggregate during production, resulting in the formation of coarse aggregates. However, by keeping the coating amount below the above-mentioned upper limit, the elasticity and elastic properties derived from the silicone elastomer particles are sufficiently maintained, effectively achieving technical effects such as stress relaxation when incorporated into materials such as epoxy resins. Furthermore, in one aspect of the present invention, the silicone resin coating layer may contain any amount of T siloxane units. However, it is preferable that the silicone resin coating layer contains both T siloxane units and Q siloxane units, and that the mass of the T siloxane units does not exceed the mass of the Q siloxane units. It is particularly preferable that the mass ratio of the T siloxane units to the Q siloxane units is in the range of 4:6 to 0:10. When the mass ratio of the T siloxane units to the Q siloxane units is within the above-mentioned range, aggregation and gelation can be suppressed. Furthermore, if the silicone resin coating layer is substantially free of T siloxane units and contains only Q siloxane units (the content of T siloxane units is generally within the range of 0.0 to 0.5% by mass), this has the advantage of most favorably suppressing aggregation and gelation.

[0060] The amount of the silicone resin coating can be easily controlled by controlling the amount of the hydrolyzable silane that forms the silicone resin added to the crosslinkable composition for forming silicone elastomer particles.

[0061] When the JIS-E hardness is 20 or less, the amount of silicone resin coating is preferably in the range of 20.0 to 40.0 parts by mass, and more preferably in the range of 22.5 to 30 parts by mass, per 100 parts by mass of the silicone elastomer particles. Even when the particles have a JIS-E hardness of 20 or less, by setting the coating amount to 20.0 parts by mass or more, the silicone resin-coated silicone elastomer particles can maintain high dispersibility even when dried.

[0062] [Coating State of Silicone Elastomer Particles with Silicone Resin] The silicone resin-coated silicone elastomer particles according to one embodiment of the present invention can be uniformly and smoothly coated with a silicone resin coating in which epoxy groups are dispersed on the surface, particularly by employing the preferred manufacturing process described in the next section, thereby achieving a coating state with very few protrusions or irregularities on the silicone resin surface. In particular, when spherical silicone elastomer particles are uniformly coated with the silicone resin coating, the smooth particle surface suppresses secondary aggregation between particles, suppressing an increase in secondary particle size, while reducing the occurrence of surface friction, thereby achieving stress relaxation and lubricity. In one embodiment of the present invention, the silicone resin coating may cover only a portion of the surface of the silicone elastomer particles, but preferably covers the entire surface. "Coating a portion of the surface of the silicone elastomer particles" means that there may be exposed portions of the silicone elastomer particles that are not covered by the silicone resin coating.

[0063] [Formation of Silicone Resin-Coated Silicone Elastomer Particles] A method for producing silicone resin-coated silicone elastomer particles according to one embodiment of the present invention comprises: Step (I): emulsifying in water a mixture comprising: (a) an organopolysiloxane having at least two alkenyl groups having 2 to 20 carbon atoms in its molecule; (b) an organohydrogenpolysiloxane having at least two silicon-bonded hydrogen atoms in its molecule; and (d) a silane-based compound; Step (II): curing the emulsion obtained in Step (I) in the presence of (c) a hydrosilylation reaction catalyst to obtain silicone elastomer particles; and Step (III): simultaneously with or after Step (II), coating part or all of the surfaces of the silicone elastomer particles with the (d) silane-based compound and, optionally, with a silicone resin containing the (e) silane-based compound added during Step (III). This manufacturing method makes it possible to suitably manufacture the silicone resin-coated silicone elastomer particles according to one aspect of the present invention.

[0064] The above components (a), (b), and (c) may be the same as those described above. When components (d) and (e) contain a hydrolyzable silane, the hydrolyzable silane may be the same as those described above.

[0065] More specifically, in step (I) of one embodiment of the manufacturing method of the present invention, a mixture containing a crosslinkable composition for forming silicone elastomer particles, including components (a) and (b), and a silane-based compound (d) is emulsified in an aqueous surfactant solution. The particle size can be easily controlled by adjusting the particle size of the emulsified particles. Examples of surfactants include nonionic, anionic, cationic, and betaine surfactants. However, for the purpose of improving electrical reliability, it is possible and sometimes preferable to emulsify the silicone elastomer particles using only a nonionic surfactant without using an ionic surfactant. The particle size of the resulting silicone elastomer particles varies depending on the type and content of the surfactant. To prepare silicone elastomer particles with a small particle size, the amount of surfactant added is preferably within a range of 0.5 to 50 parts by mass per 100 parts by mass of the crosslinkable composition. On the other hand, to prepare silicone elastomer particles with a large particle size, the amount of surfactant added is preferably within a range of 0.1 to 10 parts by mass per 100 parts by mass of the crosslinkable composition. The amount of water added as a dispersion medium is preferably within a range of 20 to 1,500 parts by mass, or 50 to 1,000 parts by mass, per 100 parts by mass of the crosslinkable composition. Also, it is preferable that the component (d), the silane-based compound, contains a hydrolyzable silane.

[0066] To uniformly disperse the crosslinkable composition for forming silicone elastomer particles and the silane compound in water, it is preferable to use an emulsifier, such as a homomixer, paddle mixer, Henschel mixer, homodisper, colloid mill, propeller agitator, homogenizer, in-line continuous emulsifier, ultrasonic emulsifier, or vacuum kneader.

[0067] In step (II), the emulsion obtained in step (I) is cured in the presence of a hydrosilylation reaction catalyst (c) to obtain silicone elastomer particles. Specifically, the aqueous dispersion of the crosslinkable composition for forming silicone elastomer particles containing a silane compound, prepared by the above method, is heated or allowed to stand at room temperature to cure the crosslinkable silicone elastomer composition in the aqueous dispersion, thereby preparing an aqueous dispersion of silicone elastomer particles. When the aqueous dispersion of silicone elastomer particles is heated, the heating temperature is preferably 100°C or less, and more preferably 10 to 95°C. Methods for heating the aqueous dispersion of the crosslinkable silicone elastomer composition include, for example, directly heating the aqueous dispersion or adding the aqueous dispersion to hot water.

[0068] In step (III), simultaneously with or after step (II), part or all of the surface of the silicone elastomer particles is coated with a silicone resin containing (d) a silane compound and (e) a silane compound added optionally during step (III). Specifically, simultaneously with the formation of the aqueous dispersion of the silicone elastomer particles (simultaneously with step (II)), or after the formation of the aqueous dispersion of the silicone elastomer particles (after step (II)), the surfaces of the silicone elastomer particles can be coated with the silicone resin by a hydrolysis condensation reaction of the silane compound contained in the aqueous dispersion. The conditions for coating with the silicone resin are as described above.

[0069] In step (III), the silane-based compound contained in the aqueous dispersion may be present in its entirety in the step of emulsifying in water (step (I)), or may be present in the system in multiple steps (steps (I) and (III)). That is, the silane-based compound contained in the aqueous dispersion may be a silane derived from the silane-based compound (d) in the mixture of step (I), and may further contain the silane-based compound (e) added in step (III). By adding the silane-based compound in multiple steps in this manner, the silanols contained in the silane-based compound added and reacted in the previous step are more likely to be uniformly present on the particle surface, which allows the silane-based compound present earlier to react with the silane-based compound added later to react efficiently, suppressing aggregation and increasing the amount of functional groups introduced. When the silane compound is added in multiple portions in this manner, the temperature when the subsequent silane compound is added is preferably 5 to 15° C., and from the viewpoint of effectively completing the condensation reaction after the addition of the silane compound, the reaction is preferably carried out at 50 to 75° C. When the silane compound (e) is added in step (III), it is preferable that the silane compound (e) contains a hydrolyzable silane.

[0070] In step (III), a portion or all of the surface of the silicone elastomer particles is coated with a silicone resin containing a silane compound. The "silane compound" includes not only hydrolyzable silanes (organotrialkoxysilanes, diorganodialkoxysilanes, triorganoalkoxysilanes, tetraalkoxysilanes, etc.), but also compounds that form M siloxane units, D siloxane units, T siloxane units, and Q siloxane units in the silicone resin, such as oligomers (e.g., tetramers or pentamers) formed by condensation of multiple hydrolyzable silane molecules. Examples of such silane compounds other than hydrolyzable silanes include oligomers formed by condensation of multiple tetraalkoxysilane molecules. The oligomer or oligomer mixture is preferably an average dimer to 20-mer, average dimer to 10-mer, or average dimer to octamer, and may be, for example, tetraethoxysilane or its condensation product, ethyl silicate, or a mixture thereof.

[0071] In one embodiment of the present invention, the silicone resin-coated silicone elastomer particles produced may contain epoxy groups. In this case, in the production method of one embodiment of the present invention, a silane compound having an epoxy group-containing hydrocarbon group (hereinafter also referred to as epoxy group-containing silane) may be included as part of the silane compounds contained in the aqueous dispersion. The epoxy group-containing silane may be present in its entirety in the stage of emulsification in water (step (I)), or may be present in the system when the surfaces of the silicone elastomer particles are coated with the silicone resin (step (III)), or may be present in the system in multiple stages (steps (I) and (III)). In other words, when a silane compound (e) is added in step (III), at least one of the silane compound (d) and the silane compound (e) may contain an epoxy group-containing carbon silane. Furthermore, when a silane compound (e) is not added, the silane compound (d) may contain an epoxy group-containing silane. When a silane compound (e) is added in step (III), the silane compound (e) may contain an epoxy group-containing silane (the silane compound (d) may also contain an epoxy group-containing silane).

[0072] Furthermore, from the viewpoint of obtaining silicone resins including DQ silicone resins, it is preferable to use the following specific silanes as each silane compound: (d) The silane compound contains a tetraalkoxysilane or a condensation product thereof (in other words, it is preferable that at least a tetraalkoxysilane or a condensation product thereof is present in the step of emulsifying in water (step (I))), in which case the (d) silane compound may further contain a diorganodialkoxysilane (in other words, not only a tetraalkoxysilane or a condensation product thereof but also at least a diorganodialkoxysilane may be present in the step of emulsifying in water (step (I))), or the (e) silane compound may further contain a diorganodialkoxysilane (in other words, a tetraalkoxysilane or a condensation product thereof may be present in step (I) and a diorganodialkoxysilane may be added in step (III)). Here, the silane compound used for coating may be a condensation reaction product of a silane compound, and is preferably an oligomer or oligomer mixture having an average of 20-20, 2-10, or 2-8, such as tetraethoxysilane or its condensation reaction product ethyl silicate, or a mixture thereof.

[0073] Furthermore, when the silicone resin-coated silicone elastomer particles to be produced contain epoxy groups, the following silanes may be used as the silane compounds, specifically, from the viewpoint of obtaining a silicone resin containing a DQ silicone resin having epoxy groups. The (d) silane compound preferably contains a tetraalkoxysilane or a condensation product thereof, and the epoxy group-containing silane preferably contains a diorganodialkoxysilane having an epoxy group-containing hydrocarbon group (in other words, it is preferable that at least a tetraalkoxysilane or a condensation product thereof is present in the step of emulsifying in water (step (I)), and it is preferable to use at least a diorganodialkoxysilane having an epoxy group-containing hydrocarbon group as the epoxidation component). In this case, the (d) silane compound may further contain a diorganodialkoxysilane (in other words, it is preferable that not only a tetraalkoxysilane but also at least a diorganodialkoxysilane is present in the step of emulsifying in water (step (I))). In this way, excess silanol generated from the hydrolyzable silane of the Q siloxane unit reacts with the D siloxane unit, thereby reducing the amount of residual silanol groups and reducing aggregation.

[0074] By coating with the silicone resin, an aqueous dispersion of silicone resin-coated silicone elastomer particles can be obtained. This aqueous dispersion is stable at room temperature and can be used as is as a cosmetic ingredient or an additive for aqueous paints and coatings.

[0075] Furthermore, silicone resin-coated silicone elastomer particles can be prepared by removing water from an aqueous dispersion of silicone resin-coated silicone elastomer particles. Methods for removing water from the aqueous dispersion include, for example, drying using a vacuum dryer, a hot air circulation oven, or a spray dryer. The heating and drying temperature of the spray dryer must be appropriately set based on the heat resistance, crosslinking temperature, etc. of the silicone resin-coated silicone elastomer particles. To prevent secondary aggregation of the obtained microparticles, it is preferable to control the temperature of the silicone resin-coated silicone elastomer particles to below the glass transition temperature of the silicone resin coating their surfaces. The silicone elastomer particles obtained in this manner can be recovered using a cyclone, a bag filter, or the like. As mentioned above, the silicone resin-coated silicone elastomer particles can be free of ionic surfactants depending on the surfactant used for emulsification, or the ionic surfactant can be removed by known methods such as washing with water.

[0076] [Crushing / Classification Operation] The silicone resin-coated silicone elastomer particles of one embodiment of the present invention are obtained by the above-mentioned method, but when the silicone resin-coated silicone elastomer particles obtained by removing moisture or the like are aggregated, they can be mechanically crushed using a crusher such as a jet mill, a ball mill, or a hammer mill, and are preferred.Furthermore, they can be classified using a sieve or an airflow classifier so as to have a specific particle size or less.In particular, by using mechanically crushing the silicone resin-coated silicone elastomer particles containing aggregates, it is possible to obtain uniform functional particles that do not contain coarse particles, and the dispersibility in materials such as epoxy resins, stress relaxation properties, etc. can be improved.

[0077] [Average Primary Particle Diameter] The average primary particle diameter of the silicone resin-coated silicone elastomer particles of one embodiment of the present invention is not particularly limited, but the average primary particle diameter measured by laser diffraction scattering is preferably 0.1 to 100 μm, more preferably 0.1 to 50 μm, even more preferably 0.2 to 30 μm, and most preferably 0.5 to 10 μm. The particle diameter of the silicone resin-coated silicone elastomer particles is controlled depending on the silicone elastomer particles before coating, the coating amount, and the above-mentioned crushing / classification process. By having an average primary particle diameter equal to or less than the above upper limit, for example, when the silicone resin-coated silicone elastomer particles of one embodiment of the present invention are added to a resin for producing a thin film layer, the particle diameter can be adjusted to correspond to the thickness of the thin film layer.

[0078] [Advantages of producing silicone resin-coated silicone elastomer particles] When the silicone resin-coated silicone elastomer particles of one embodiment of the present invention are obtained by the above-mentioned production method, the surface of the silicone elastomer particles is uniformly and smoothly coated with the silicone resin, secondary aggregation of the silicone resin-coated silicone elastomer particles is effectively suppressed, and handling problems such as an increase in aggregate particle size over time are unlikely to occur. Furthermore, this production method may involve emulsifying a mixture containing a crosslinkable composition for forming silicone elastomer particles and a hydrolyzable silane to form an aqueous dispersion, and carrying out the curing reaction and surface coating with the silicone resin in the same container (i.e., one pod).

[0079] [Content of Silicone Resin-Coated Silicone Elastomer Particles] In the composition of one embodiment of the present invention, the content of the silicone resin-coated silicone elastomer particles is, for example, 0.1% by mass or more, preferably 0.5% by mass or more, more preferably 1% by mass or more, and even more preferably 3% by mass or more, based on 100% by mass of the total solids content of the composition. This allows the cured product of the composition to be endowed with excellent heat resistance and / or a favorable low coefficient of thermal expansion. Furthermore, in the composition of one embodiment of the present invention, the content of the silicone resin-coated silicone elastomer particles is, for example, 20% by mass or less, preferably 15% by mass or less, and more preferably 10% by mass or less, based on 100% by mass of the total solids content of the composition. It is generally used in the range of 0.1 to 15% by mass, or 0.1 to 10% by mass, based on 100% by mass of the total solids content of the composition. This allows the composition to maintain an appropriate modulus of elasticity without excessively reducing strength.

[0080] <Component (B): Epoxy Resin> The composition of one embodiment of the present invention contains an epoxy resin (B). The epoxy resin (B) is a curable resin having an epoxy group, and specific examples thereof include bixylenol-type epoxy resins, bisphenol A-type epoxy resins, bisphenol F-type epoxy resins, bisphenol S-type epoxy resins, bisphenol AF-type epoxy resins, dicyclopentadiene-type epoxy resins, trisphenol-type epoxy resins, naphthol novolac-type epoxy resins, phenol novolac-type epoxy resins, tert-butyl-catechol-type epoxy resins, naphthalene-type epoxy resins, naphthol-type epoxy resins, anthracene-type epoxy resins, and glycidylamine-type epoxy resins. Examples of epoxy resins include epoxy resins, glycidyl ester type epoxy resins, cresol novolac type epoxy resins, phenol aralkyl type epoxy resins, biphenyl type epoxy resins, linear aliphatic epoxy resins, epoxy resins having a butadiene structure, alicyclic epoxy resins, heterocyclic epoxy resins, spiro ring-containing epoxy resins, cyclohexane type epoxy resins, cyclohexane dimethanol type epoxy resins, naphthylene ether type epoxy resins, trimethylol type epoxy resins, tetraphenylethane type epoxy resins, isocyanurate type epoxy resins, phenolphthalimidine type epoxy resins, etc. One type of epoxy resin may be used alone, or two or more types may be used in combination.

[0081] Furthermore, from the viewpoint of obtaining a cured product having excellent heat resistance, the epoxy resin (B) preferably contains an epoxy resin containing an aromatic structure. The aromatic structure is a chemical structure generally defined as aromatic, and also includes polycyclic aromatics and aromatic heterocycles. Specific examples of epoxy resins containing an aromatic structure include bisphenol A type epoxy resins, bisphenol F type epoxy resins, bisphenol S type epoxy resins, bisphenol AF type epoxy resins, dicyclopentadiene type epoxy resins, trisphenol type epoxy resins, naphthol novolac type epoxy resins, phenol novolac type epoxy resins, tert-butyl-catechol type epoxy resins, naphthalene type epoxy resins, naphthol type epoxy resins, anthracene type epoxy resins, bisphenolol type epoxy resins, and glycidylamine type epoxy resins having an aromatic structure. resins, glycidyl ester type epoxy resins having an aromatic structure, cresol novolac type epoxy resins, biphenyl type epoxy resins, linear aliphatic epoxy resins having an aromatic structure, epoxy resins having a butadiene structure having an aromatic structure, alicyclic epoxy resins having an aromatic structure, heterocyclic epoxy resins, spiro ring-containing epoxy resins having an aromatic structure, cyclohexanedimethanol type epoxy resins having an aromatic structure, naphthylene ether type epoxy resins, trimethylol type epoxy resins having an aromatic structure, tetraphenylethane type epoxy resins having an aromatic structure, and the like.

[0082] The content of the epoxy resin (B) is, for example, 1% by mass or more, preferably 2% by mass or more, relative to 100% by mass of the total solid content of the composition. This allows the fluidity of the composition during molding to be appropriately set, improving filling properties. The content of the epoxy resin (B) is, for example, 15% by mass or less, preferably 10% by mass or less, more preferably 5% by mass or less, relative to 100% by mass of the total solid content of the composition. Typically, the thermal expansion coefficient of a resin is greater than that of the inorganic filler (D) described below. Therefore, it is believed that thermal shrinkage can be further reduced by relatively reducing the amount of the epoxy resin (B). In other words, it is believed that warpage of the substrate can be further reduced. The total solid content of the composition refers to the sum of all components contained in the composition of one embodiment of the present invention, excluding the solvent.

[0083] <Component (C): Curing Agent> The composition of one embodiment of the present invention contains a curing agent (C). The curing agent (C) is not particularly limited as long as it has the property of curing an epoxy resin. The curing agent (C) preferably contains a phenolic curing agent. Phenol-based curing agents are preferred in terms of the balance of flame resistance, moisture resistance, electrical properties, curability, storage stability, etc. Phenolic curing agents include monomers, oligomers, polymers, etc. having two or more phenolic hydroxyl groups in the molecule. The molecular weight, molecular structure, etc. are not particularly limited. More specifically, the phenolic curing agent includes novolac-type phenolic resins such as phenol novolac resin, cresol novolac resin, bisphenol novolac, and phenol-biphenyl novolac resin; polyvinylphenol; multifunctional phenolic resins such as trisphenylmethane-type phenolic resin; modified phenolic resins such as terpene-modified phenolic resin and dicyclopentadiene-modified phenolic resin; phenol aralkyl-type phenolic resins such as phenol aralkyl resins having a phenylene skeleton and / or biphenylene skeleton, and naphthol aralkyl resins having a phenylene and / or biphenylene skeleton; and bisphenol compounds such as bisphenol A and bisphenol F.

[0084] Examples of the curing agent (C) other than the phenol-based curing agent include amine-based curing agents, acid anhydride-based curing agents, mercaptan-based curing agents, and catalyst-based curing agents. Specific examples of the amine-based curing agents include aliphatic polyamines and aromatic polyamines. Specific examples of the acid anhydride-based curing agents include alicyclic acid anhydrides such as hexahydrophthalic anhydride (HHPA) and methyltetrahydrophthalic anhydride (MTHPA), and aromatic acid anhydrides such as trimellitic anhydride (TMA), pyromellitic anhydride (PMDA), and benzophenonetetracarboxylic acid (BTDA). Specific examples of the mercaptan-based curing agents include polymercaptan compounds such as polysulfides, thioesters, and thioethers. Specific examples of the catalyst-based curing agents include tertiary amine compounds such as benzyldimethylamine (BDMA) and 2,4,6-trisdimethylaminomethylphenol; imidazole compounds such as 2-methylimidazole and 2-ethyl-4-methylimidazole; and BF ３ The curing agent (B) may be used singly or in combination of two or more kinds.

[0085] The content of the curing agent (C) is, for example, 0.5% by mass or more, preferably 1% by mass or more, more preferably 1.5% by mass or more, based on 100% by mass of the total solid content of the composition. This provides excellent fluidity during molding, improving filling and moldability. The content of the curing agent (C) is, for example, 9% by mass or less, preferably 8% by mass or less, more preferably 7% by mass or less, based on 100% by mass of the total solid content of the composition. This can contribute to further suppressing warpage of the substrate.

[0086] <Component (D): Filler> The composition of one embodiment of the present invention contains a filler (D). The filler (D) may be an inorganic filler or an organic filler. Specific examples of inorganic fillers include silica, alumina, silicon nitride, aluminum nitride, boron nitride, titanium oxide, silicon carbide, titanium white, aluminum hydroxide, magnesium hydroxide, talc, clay, mica, glass fiber, and carbon allotropes such as diamond, graphite, carbon nanotubes, and graphene. Specific examples of organic fillers include rubber powders such as styrene-type, butadiene-type, and acrylic-type, silicone resin powders, silicone elastomer particles, silicone elastomer composite particles, silicone resin-coated silicone elastomer particles (excluding those corresponding to component (A) of the present invention), and resins such as acrylic core-shell particles. One type of filler (D) may be used alone, or two or more types may be used in combination. The particle shape is preferably as spherical as possible, and the loading amount can be increased by mixing particles of different sizes. Furthermore, from the viewpoint of heat dissipation, it is also possible to partially or completely replace silica with alumina, silicon nitride, aluminum nitride, boron nitride, etc. Among these, the filler (D) preferably contains an inorganic filler, more preferably silica. Examples of silica include fused crushed silica, fused spherical silica, crystalline silica, and secondary agglomerated silica.

[0087] As described above, the filler (D) is typically particulate, and the particle shape may be, but is not limited to, a spherical shape. The average particle size of the filler (D) is not particularly limited, but is typically 0.1 to 100 μm, 1 to 100 μm, preferably 0.5 to 50 μm, 1 to 50 μm, and more preferably 1 to 20 μm. Having an average particle size within the above range can ensure appropriate fluidity during curing. Furthermore, by making the average particle size relatively small (e.g., 1 to 20 μm) and combining particles of different average particle sizes, it is possible to improve the filling ability into narrow gaps in cutting-edge wafer-level packages, for example. The average particle size of the filler (D) can be determined by acquiring volumetric particle size distribution data using a laser diffraction / scattering particle size distribution analyzer and processing the data. Measurement is typically performed wet.

[0088] When the filler (D) is an inorganic filler such as silica, it may be surface-modified with a coupling agent such as a silane coupling agent or a titanium-based coupling agent. This suppresses aggregation of the inorganic filler, resulting in better fluidity. Furthermore, the affinity between the inorganic filler and other components is increased, improving the dispersibility of the inorganic filler. This is thought to contribute to improving the mechanical strength of the cured product and suppressing the occurrence of microcracks. The coupling agent for surface modification will be described later in the section on coupling agent (E).

[0089] The content of the filler (D) is, for example, 45% by mass or more, 55% by mass or more, preferably 70% by mass or more, and more preferably 85% by mass or more, relative to 100% by mass of the total solids content of the composition. By appropriately increasing the content of the filler (D), warpage of the chip or substrate can be further reduced. In addition, by appropriately increasing the content of the filler (D) and relatively reducing the resin component, thermal expansion change after the composition is cured can be reduced. Small thermal expansion change makes it easier to suppress deterioration of warpage. In addition, the content of the filler (D) is, for example, 98% by mass or less, preferably 95% by mass or less, and more preferably 92% by mass or less, relative to 100% by mass of the total solids content of the composition. By appropriately reducing the content of the filler (D), it is possible to suppress deterioration of moldability due to reduced fluidity during molding.

[0090] <Component (E): Coupling Agent> The composition of one embodiment of the present invention may optionally contain a coupling agent (E) (hereinafter also referred to as "component (E)"). By containing the coupling agent (E), for example, it is possible to further improve adhesion to the substrate and improve the dispersibility of the filler (D) in the composition. The improved dispersibility of the filler (D) improves the homogeneity of the final cured product, which can contribute to improving the mechanical strength of the cured product.

[0091] Examples of the coupling agent (E) include known coupling agents such as epoxysilane, mercaptosilane, aminosilane, alkylsilane, ureidosilane, alkenylsilane such as vinylsilane or hexenylsilane, various silane compounds such as acrylic silane and methacrylic silane, titanium compounds, aluminum chelates, and aluminum / zirconium compounds. The coupling agent (E) may be used alone or in combination of two or more. Also, known surface treatment agents such as silazane may be used in combination.

[0092] The content of the coupling agent (E) is, for example, 0.1% by mass or more, preferably 0.2% by mass or more, based on the total mass of the composition. The coupling agent (E) is generally used in a treatment amount ranging from 0.01 to 2% by mass, based on the total mass of the filler (D) taken as 100% by mass. The content of the coupling agent (E) is, for example, 2.0% by mass or less, preferably 1.0% by mass or less, based on the total mass of the composition.

[0093] <Other Components> The composition of one embodiment of the present invention may contain other optional components as needed. Examples of such optional components include various additives such as pH adjusters, ion scavengers, flame retardants, colorants, release agents, stress reducing agents (excluding those corresponding to the silicone resin-coated silicone elastomer particles of one embodiment of the present invention), antioxidants, and heavy metal deactivators. Specific examples of such additives include those listed in JP 2020-023643 A (see paragraphs

[0070] to

[0075] ), WO 2024 / 202136 A (

[0083] to

[0086] ), and WO 2021 / 149727 A (

[0090] to

[0093] ). When these optional components are contained, the content of each component varies depending on the type and application, but may be within a range that does not impair the effects of the present invention, and is, for example, in the range of 0.1 to 5.0 mass%, preferably 0.1 to 3.0 mass%, and more preferably 0.2 to 1.5 mass%.

[0094] 2. Methods for Producing the Composition of the Present Invention, Methods for Forming a Cured Product, and Uses The composition of one embodiment of the present invention can be produced by uniformly mixing components (A) to (D) and optional components such as component (E). Mixing can be performed using appropriate equipment such as a mixer or blender. The resulting mixture can be melt-kneaded using a kneader, heated rolls, or the like, preferably at a temperature of 40°C to 130°C, and then cooled and solidified to produce a composition of one embodiment of the present invention (specifically, a liquid, solid, or hot-melt (also known as B-stage) curable epoxy resin composition). The composition may be pulverized into powder or granules. Alternatively, a powder / granular composition may be compressed into tablets. Furthermore, a sheet-like composition can be produced by placing the mixture of the composition on a pallet, cooling it, and then applying a press roll, roll rolling, or coating it with a solvent mixture to form a sheet.

[0095] The composition of one embodiment of the present invention can be melted by heating or the like, and then finally cured by heating to form a cured product of the composition of one embodiment of the present invention. In this case, the curing reaction temperature is, for example, in the range of 100 to 300°C, preferably 150 to 250°C, more preferably 150 to 200°C, and even more preferably 170 to 180°C.

[0096] The cured product of one embodiment of the present invention has heat resistance and / or a low coefficient of thermal expansion, making it suitable for use in the manufacture of semiconductor devices. More specifically, the cured product can be used, for example, as an encapsulant for semiconductor elements, IC chips, and the like, as a pressure-sensitive adhesive for semiconductor devices, adhesives, underfill agents, insulating materials, and build-up materials for package substrates and the like. Furthermore, a comparison of the dielectric constants (Dk [5-10 GHz]) of the blank of Comparative Example 1, the silicone resin of Comparative Example 2, and the silicone elastomer particles of Comparative Example 5 in Table 1 of paragraph 0090 of JP 2023-034257 indicates that the silicone elastomer particles are also expected to have a low dielectric effect. This property also allows for application to package substrates and the like.

[0097] 3. Semiconductor Device and Method for Producing a Semiconductor Device As one aspect, the present invention provides a semiconductor device (hereinafter also referred to as "the semiconductor device of the present invention") comprising the cured product described above in "2. Method for Producing the Composition of the Present Invention, Method for Forming a Cured Product, and Uses." Specific examples of the semiconductor device include those described above in "2. Method for Producing the Composition of the Present Invention, Method for Forming a Cured Product, and Uses."

[0098] Furthermore, as one aspect, the present invention provides a method for manufacturing a semiconductor device (hereinafter also referred to as "the method for manufacturing a semiconductor device of the present invention"), which includes curing the composition of one embodiment of the present invention.

[0099] Furthermore, as described above, the epoxy resin composition of the present invention, particularly the curable epoxy resin composition (powder, tablet, granule, etc.), can be suitably used as a heat-melting (B-stage material) encapsulating material for encapsulating semiconductor elements. The encapsulation method for semiconductor elements is not particularly limited, and can be performed by known methods such as conventional transfer molding and compression molding. The semiconductor package to which the cured product of the present invention can be applied is also not particularly limited, and can be used to encapsulate various semiconductor packages described, for example, in JP-A-2020-063338, JP-A-2019-085514, JP-A-2020-023643, etc.

[0100] The method for producing a semiconductor device of the present invention is not particularly limited as long as it includes a step of curing the composition of the present invention at any stage in the production process of the semiconductor device. The method for producing a semiconductor device of the present invention may also include a step of encapsulating a semiconductor element with the cured product of one aspect of the present invention.

[0101] For example, a laminate having a large number of semiconductor elements such as ICs mounted thereon is placed in a cavity of a mold, and then the cavity is filled with a composition according to one embodiment of the present invention, which is then heated and cured, thereby producing a semiconductor device in which the semiconductor elements are encapsulated with the cured product according to one embodiment of the present invention.

[0102] The molding conditions can be appropriately selected depending on the molding method, the curability of the curable resin composition, the mold temperature, and the like. For example, the conditions for transfer molding using the curable epoxy resin composition of the present invention can be appropriately set depending on the type of material in the composition of one embodiment of the present invention and the type of semiconductor device to be manufactured. Typically, the mold temperature is 170 to 180°C, and the molding time can be selected depending on the mold temperature and curability, but is generally set to 10 to 600 seconds, or 30 to 120 seconds. After the initial curing, post-curing or heat treatment can be carried out for a period ranging from several seconds to several hours to complete the curing reaction.

[0103] Furthermore, the sheet-like composition described above can be used to manufacture a semiconductor device by flip-chip mounting, for example, as follows: That is, the sheet-like composition is placed on the electrode surface side of a semiconductor element having bonding bumps or on the bump bonding side of a circuit board, and the semiconductor element and the circuit board are bump-bonded and adhesively sealed with a resin, thereby manufacturing a semiconductor device by flip-chip mounting.

[0104] The silicone resin-coated silicone elastomer particles of the present invention and their production method will be explained in detail using examples and comparative examples. However, the present invention is not limited to these examples. The viscosity values ​​in the examples are values ​​at 25°C. The properties of each silicone particle were measured as follows. Unless otherwise specified in the examples, silicone particles are a general term for particles made of a silicone cured product (cured silicone particles) and do not include emulsions.

[0105] <Preparation of Silicone Resin-Coated Silicone Elastomer Particles> Preparation Examples 1 to 13 Silicone resin-coated silicone elastomer particles were prepared using the raw materials shown below. Each property was measured by the following methods.

[0106] [JIS-A Hardness and JIS-E Hardness of Silicone Elastomer Particles] The crosslinkable composition for forming silicone elastomer particles, which is the raw material for the silicone elastomer particles, was heated in a heating oven at 150°C for 1 hour to harden it into a sheet. The hardness of this sheet was measured using a JIS-A hardness tester or a JIS-E hardness tester specified in JIS K 6253.

[0107] [Average Primary Particle Diameter of Silicone Elastomer Particles] Emulsion particles before the addition of the platinum catalyst were measured using a laser diffraction particle size distribution analyzer (Beckman Coulter LS-230 or Malvern Mastersizer 3000), and the median diameter (particle size corresponding to 50% of the cumulative distribution, 50% particle size) was taken as the average primary particle size of the silicone elastomer particles. It is also possible to measure the particle size of cured silicone particles of dried silicone elastomer particles using ethanol as a dispersion medium using a laser diffraction particle size distribution analyzer (Malvern Mastersizer 3000). It has been confirmed that the median diameter (particle size corresponding to 50% of the cumulative distribution, D90, μm) and the average primary particle size based on arithmetic dispersity (indicating the degree of dispersion of the particle size distribution, SD, μm2) of cured silicone particles in ethanol nearly coincide with the average primary particle size based on the above-mentioned emulsion particle size measurement.

[0108] [Silicone elastomer particle forming components] The average formulas of the various polyorganosiloxanes used in Preparation Examples 1 to 13 are listed below. In the following formulas, Vi represents CH ２ =CH-, Me is a vinyl group ３ - represents a methyl group, and Hex represents a hexenyl group represented by CH2=CH-C4H8-. The alkenyl group content is determined by the ratio of the vinyl group (CH ２ =CH-) molecular weight ratio. [Chemical formula 1-1] Me ２ HexSiO-(Me ２ SiO) ５７ -(MeHexSiO) ３ -SiHexMe ２ The alkenyl group content is 2.7% by mass. The viscosity is 100 mPa·s. [Chemical Formula 1-2] Me２ HexSiO-(Me ２ SiO) １１０ -(MeHexSiO) １．５ -SiHexMe ２ The alkenyl group content is 1.0% by mass. The viscosity is 420 mPa·s. [Chemical Formula 1-3] Me ２ ViSiO-(Me ２ SiO) １５０ -SiViMe ２ The alkenyl group content is 0.47% by mass. The viscosity is 350 mPa·s. [Chemical Formula 1-4] Me ２ HexSiO-(Me ２ SiO) １３０ -(MeHexSiO) １５ -SiHexMe ２ The alkenyl group content is 4.0% by mass. The viscosity is 500 mPa·s. [Chemical Formula 2-1] (Me ３ SiO １／２ ) ２ (Me ２ SiO ２／２ ) ７ (HMeSiO ２／２ ) １２ (MeSiO ３／２ ) １ The silicon-bonded hydrogen atom content is 0.84% ​​by mass. The viscosity is 15 mPa·s. [Chemical Formula 2-2] Me ２ HSiO-(Me ２ SiO ２／２ ) １４ -SiHMe ２ The silicon-bonded hydrogen atom content is 0.12% by mass. The viscosity is 10 mPa·s. [Chemical Formula 2-3] Me ２ HSiO-(Me ２ SiO ２／２ ) ６０ -SiHMe ２ The silicon-bonded hydrogen atom content is 0.039% by mass. The viscosity is 70 mPa·s. [Chemical Formula 2-4] Me ２ HSiO-(Me ２ SiO ２／２ ) １８７ -SiHMe ２The silicon-bonded hydrogen atom content is 0.015% by mass. The viscosity is 500 mPa·s. [Chemical Formula 3-1] Dimethylpolysiloxane (XIAMETER manufactured by Dow-Toray Industries, Inc.) ＴＭ PMX-200 Silicone Fluid 100 cSt) Viscosity is 100 mPa·s.

[0109] [Preparation Example 1] 84 parts by mass of a polyorganosiloxane represented by the average formula [Chemical Formula 1-4] and 16 parts by mass of a polyorganosiloxane represented by the average formula [Chemical Formula 2-1] were uniformly mixed at room temperature. 14 parts by mass of a condensation reaction product of tetraethoxysilane (an oligomer mixture with an average pentamer) and 6 parts by mass of dimethyldimethoxysilane were added and further mixed. Next, this composition was dispersed in an aqueous solution at 25°C consisting of 1.7 parts by mass of polyoxyethylene sorbitan laurate, 0.3 parts by mass of polyoxyalkylene alkyl ester, and 20 parts by mass of pure water, and further uniformly emulsified using a colloid mill. The average primary particle size was 2.1 μm. Subsequently, 370 parts by mass of pure water was added to dilute the mixture to prepare an emulsion. Next, an isopropyl alcohol solution of chloroplatinic acid (in an amount that would result in 10 ppm platinum metal by mass in the composition) was added to the emulsion to form an aqueous dispersion with polyoxyethylene sorbitan laurate and pure water, and after stirring, the emulsion was allowed to stand at 50°C for 1 hour to carry out a hydrosilylation reaction. Subsequently, 17.5 parts by mass of 28% aqueous ammonia was added. The pH of the solution at this point was 11. The mixture was stirred for an additional 5 hours to carry out the condensation reaction, producing a uniform aqueous suspension of silicone resin-coated silicone elastomer particles. This aqueous suspension was then dried in an airflow dryer (Seishin Enterprise, model number: FJD-2B) to yield silicone resin-coated silicone elastomer particles. The resulting silicone elastomer particles had a JIS-A hardness of 70 and a JIS-E hardness of 74.

[0110] [Preparation Example 2] 93.7 parts by mass of a polyorganosiloxane represented by the average formula [Chemical Formula 1-1] and 6.3 parts by mass of a polyorganosiloxane represented by the average formula [Chemical Formula 2-1] were mixed uniformly at room temperature. 14 parts by mass of a condensation reaction product of tetraethoxysilane (an oligomer mixture with an average pentamer) and 6 parts by mass of dimethyldimethoxysilane were added and further mixed. Next, this composition was dispersed in an aqueous solution at 25°C consisting of 1.9 parts by mass of polyoxyethylene sorbitan laurate, 0.3 parts by mass of polyoxyalkylene alkyl ester, and 22 parts by mass of pure water, and further uniformly emulsified using a colloid mill. The average primary particle size was 1.6 μm. Subsequently, 640 parts by mass of pure water was added to dilute the mixture to prepare an emulsion. Next, an isopropyl alcohol solution of chloroplatinic acid (in an amount that would result in 10 ppm platinum metal by mass in the composition) was added to the emulsion to form an aqueous dispersion using polyoxyethylene sorbitan laurate and pure water. After stirring, the emulsion was allowed to stand at 50°C for 1 hour to carry out a hydrosilylation reaction. Subsequently, 17.5 parts by mass of 28% aqueous ammonia was added. The pH of the solution at this stage was 11. The mixture was stirred for an additional 5 hours to carry out the condensation reaction, yielding a uniform aqueous suspension of silicone resin-coated silicone elastomer particles. This aqueous suspension was then dried in an airflow dryer (Seishin Enterprise, model number: FJD-2B) to yield silicone resin-coated silicone elastomer particles. The resulting silicone elastomer particles had a JIS-A hardness of 40 and a JIS-E hardness of 49.

[0111] [Preparation Example 3] 97.4 parts by mass of a polyorganosiloxane represented by the average formula [Chemical Formula 1-2] and 2.6 parts by mass of a polyorganosiloxane represented by the average formula [Chemical Formula 2-1] were uniformly mixed at room temperature. 14 parts by mass of a condensation reaction product of tetraethoxysilane (an oligomer mixture with an average pentamer) and 6 parts by mass of dimethyldimethoxysilane were added and further mixed. Next, this composition was dispersed in an aqueous solution at 25°C consisting of 1.9 parts by mass of polyoxyethylene sorbitan laurate, 0.3 parts by mass of polyoxyalkylene alkyl ester, and 22 parts by mass of pure water, and further uniformly emulsified using a colloid mill. The average primary particle size was 1.9 μm. The emulsion was then diluted with 440 parts by mass of pure water to prepare an emulsion. Next, an isopropyl alcohol solution of chloroplatinic acid (in an amount that would result in 10 ppm platinum metal by mass in the composition) was added to the emulsion to form an aqueous dispersion using polyoxyethylene sorbitan laurate and pure water. After stirring, the emulsion was allowed to stand at 50°C for 1 hour to carry out a hydrosilylation reaction. Subsequently, 17.5 parts by mass of 28% aqueous ammonia was added. The pH of the solution at this stage was 11. The mixture was stirred for an additional 5 hours to carry out the condensation reaction, yielding a uniform aqueous suspension of silicone resin-coated silicone elastomer particles. This aqueous suspension was then dried in an airflow dryer (Seishin Enterprise, model number: FJD-2B) to yield silicone resin-coated silicone elastomer particles. The resulting silicone elastomer particles had a JIS-A hardness of 25 and a JIS-E hardness of 35.

[0112] [Preparation Example 4] 97.4 parts by mass of a polyorganosiloxane represented by the average formula [Chemical Formula 1-2] and 2.6 parts by mass of a polyorganosiloxane represented by the average formula [Chemical Formula 2-1] were mixed uniformly at room temperature. 16 parts by mass of a condensation reaction product of tetraethoxysilane (an oligomer mixture with an average pentamer) and 4 parts by mass of dimethyldimethoxysilane were added and further mixed. Next, this composition was dispersed in an aqueous solution at 25°C consisting of 1.9 parts by mass of polyoxyethylene sorbitan laurate, 0.3 parts by mass of polyoxyalkylene alkyl ester, and 22 parts by mass of pure water, and further uniformly emulsified using a colloid mill. The average primary particle size was 2.3 μm. Subsequently, 440 parts by mass of pure water was added to dilute the mixture to prepare an emulsion. Next, an isopropyl alcohol solution of chloroplatinic acid (in an amount that would result in 10 ppm platinum metal by mass in the composition) was added to the emulsion to form an aqueous dispersion using polyoxyethylene sorbitan laurate and pure water. After stirring, the emulsion was allowed to stand at 50°C for 1 hour to carry out a hydrosilylation reaction. Then, 12 parts by mass of 28% aqueous ammonia was added. The pH of the solution at this point was 11. The mixture was stirred for an additional 5 hours to carry out the condensation reaction, producing a uniform aqueous suspension of silicone resin-coated silicone elastomer particles. This aqueous suspension was then dried in an airflow dryer (Seishin Enterprise, model number: FJD-2B) to yield silicone resin-coated silicone elastomer particles. The resulting silicone elastomer particles had a JIS-A hardness of 25 and a JIS-E hardness of 35.

[0113] [Preparation Example 5] 97.4 parts by mass of a polyorganosiloxane represented by the average formula [Chemical Formula 1-2] and 2.6 parts by mass of a polyorganosiloxane represented by the average formula [Chemical Formula 2-1] were mixed uniformly at room temperature. 12.6 parts by mass of a condensation reaction product of tetraethoxysilane (an oligomer mixture with an average pentamer) and 5.4 parts by mass of dimethyldimethoxysilane were added and further mixed. Next, this composition was dispersed in an aqueous solution at 25°C consisting of 1.4 parts by mass of polyoxyethylene sorbitan laurate, 0.2 parts by mass of polyoxyalkylene alkyl ester, and 30 parts by mass of pure water, and further uniformly emulsified using a colloid mill. The average primary particle size was 4.2 μm. Subsequently, 380 parts by mass of pure water was added to dilute the mixture to prepare an emulsion. Next, an isopropyl alcohol solution of chloroplatinic acid (in an amount that would result in 10 ppm platinum metal by mass in the composition) was added to the emulsion with polyoxyethylene sorbitan laurate and pure water to form an aqueous dispersion. After stirring, the emulsion was allowed to stand at 50°C for 1 hour to carry out a hydrosilylation reaction. The aqueous suspension was then cooled to 10-15°C, and 60 parts by mass of 28% aqueous ammonia was added. The pH of the solution at this time was 11. While cooling and stirring, 9.0 parts by mass of glycidoxypropyl(methyl)dimethoxysilane was slowly added dropwise over 20 minutes or more, and the mixture was stirred at this temperature for a total of 3 hours. The liquid temperature was then raised to 50°C, and the mixture was stirred for 5 hours to carry out a condensation reaction, producing a uniform aqueous suspension of silicone rubber particles coated with silicone resin. This aqueous suspension was then dried in an airflow dryer (Seishin Enterprise, FJD-2B) to obtain silicone resin-coated silicone elastomer particles. The resulting silicone elastomer particles had a JIS-A hardness of 25 and a JIS-E hardness of 35.

[0114] [Preparation Example 6] 97.4 parts by mass of a polyorganosiloxane represented by the average formula [Chemical Formula 1-2] and 2.6 parts by mass of a polyorganosiloxane represented by the average formula [Chemical Formula 2-1] were uniformly mixed at room temperature. 14 parts by mass of a condensation reaction product of tetraethoxysilane (an oligomer mixture with an average pentamer) and 6 parts by mass of dimethyldimethoxysilane were added and further mixed. Next, this composition was dispersed in an aqueous solution at 25 ° C consisting of 1.4 parts by mass of polyoxyethylene sorbitan laurate, 0.2 parts by mass of polyoxyalkylene alkyl ester, and 30 parts by mass of pure water, and further uniformly emulsified using a colloid mill. The average primary particle diameter was 4.2 μm. Then, 400 parts by mass of pure water was added to dilute the emulsion. Next, an isopropyl alcohol solution of chloroplatinic acid (in an amount that would result in 10 ppm platinum metal by mass in the composition) was added to the emulsion with polyoxyethylene sorbitan laurate and pure water to form an aqueous dispersion, which was then stirred. The emulsion was then allowed to stand at 50°C for 1 hour to carry out a hydrosilylation reaction. The aqueous suspension was then cooled to 10-15°C, and 50 parts by mass of 28% aqueous ammonia was added. The pH of the solution at this time was 11. While cooling and stirring, 4.5 parts by mass of glycidoxypropyl(methyl)dimethoxysilane was slowly added dropwise over 20 minutes or more, and the mixture was stirred at this temperature for a total of 3 hours. The liquid temperature was then raised to 50°C, and the mixture was stirred for 5 hours to carry out a condensation reaction, producing a uniform aqueous suspension of silicone rubber particles coated with silicone resin. This aqueous suspension was then dried in an airflow dryer (Seishin Enterprise, FJD-2B) to obtain silicone resin-coated silicone elastomer particles. The resulting silicone elastomer particles had a JIS-A hardness of 25 and a JIS-E hardness of 35.

[0115] [Preparation Example 7] 97.4 parts by mass of a polyorganosiloxane represented by the average formula [Chemical Formula 1-2] and 2.6 parts by mass of a polyorganosiloxane represented by the average formula [Chemical Formula 2-1] were uniformly mixed at room temperature. 14 parts by mass of a condensation reaction product of tetraethoxysilane (an oligomer mixture with an average pentamer) and 6 parts by mass of dimethyldimethoxysilane were added and further mixed. Next, this composition was dispersed in an aqueous solution at 25 ° C consisting of 1.4 parts by mass of polyoxyethylene sorbitan laurate, 0.2 parts by mass of polyoxyalkylene alkyl ester, and 20 parts by mass of pure water, and further uniformly emulsified using a colloid mill. The average primary particle diameter was 3.6 μm. Then, 410 parts by mass of pure water was added to dilute the emulsion. Next, an isopropyl alcohol solution of chloroplatinic acid (in an amount that would result in 10 ppm platinum metal by mass in the composition) was added to the emulsion with polyoxyethylene sorbitan laurate and pure water to form an aqueous dispersion, and the resulting mixture was stirred. The emulsion was then allowed to stand at 50°C for 1 hour to carry out a hydrosilylation reaction. The aqueous suspension was then cooled to 10-15°C, and 50 parts by mass of 28% aqueous ammonia was added. The pH of the resulting solution was 11. While cooling and stirring, 9 parts by mass of glycidoxypropyl(methyl)dimethoxysilane was slowly added dropwise over 20 minutes or more, and the mixture was stirred at this temperature for a total of 3 hours. The liquid temperature was then raised to 50°C, and the mixture was stirred for 5 hours to carry out a condensation reaction, producing a uniform aqueous suspension of silicone rubber particles coated with silicone resin. This aqueous suspension was then dried in an airflow dryer (Seishin Enterprise, FJD-2B) to obtain silicone resin-coated silicone elastomer particles. The resulting silicone elastomer particles had a JIS-A hardness of 25 and a JIS-E hardness of 35.

[0116] [Preparation Example 8] 28 parts by weight of a polyorganosiloxane represented by the average formula [Chemical Formula 1-2] and 72 parts by weight of a polyorganosiloxane represented by the average formula [Chemical Formula 2-4] were mixed uniformly at room temperature. 15 parts by weight of a condensation reaction product of tetraethoxysilane (an oligomer mixture with an average pentamer) and 5 parts by weight of dimethyldimethoxysilane were added and further mixed. Next, this composition was dispersed in an aqueous solution at 25°C consisting of 1.8 parts by weight of polyoxyethylene sorbitan laurate, 0.3 parts by weight of polyoxyalkylene alkyl ester, and 16 parts by weight of pure water, and further uniformly emulsified using a colloid mill. The average primary particle size was 1.3 μm. The emulsion was then diluted with 450 parts by weight of pure water to prepare an emulsion. Next, an isopropyl alcohol solution of chloroplatinic acid (in an amount that would result in 10 ppm platinum metal by mass in the composition) was added to the emulsion to form an aqueous dispersion using polyoxyethylene sorbitan laurate and pure water, and after stirring, the emulsion was allowed to stand at 50°C for 1 hour to carry out a hydrosilylation reaction. Subsequently, 15 parts by mass of 28% aqueous ammonia was added. The pH of the solution at this stage was 11. The mixture was stirred for an additional 5 hours to carry out a condensation reaction, yielding a uniform aqueous suspension of silicone resin-coated silicone elastomer particles. This aqueous suspension was then dried in an airflow dryer (Seishin Enterprise, model number: FJD-2B) to yield silicone resin-coated silicone elastomer particles. The resulting silicone elastomer particles had a JIS-A hardness of 10 and a JIS-E hardness of 25.

[0117] [Preparation Example 9] 28 parts by weight of a polyorganosiloxane represented by the average formula [Chemical Formula 1-2] and 72 parts by weight of a polyorganosiloxane represented by the average formula [Chemical Formula 2-4] were mixed uniformly at room temperature. 19 parts by weight of a condensation reaction product of tetraethoxysilane (an oligomer mixture with an average pentamer) and 1 part by weight of dimethyldimethoxysilane were added and further mixed. Next, this composition was dispersed in an aqueous solution at 25°C consisting of 1.8 parts by weight of polyoxyethylene sorbitan laurate, 0.3 parts by weight of polyoxyalkylene alkyl ester, and 17 parts by weight of pure water, and further uniformly emulsified using a colloid mill. The average primary particle size was 2.6 μm. The emulsion was then diluted with 450 parts by weight of pure water to prepare an emulsion. Next, an isopropyl alcohol solution of chloroplatinic acid (in an amount that would result in 10 ppm platinum metal by mass in the composition) was added to the emulsion to form an aqueous dispersion using polyoxyethylene sorbitan laurate and pure water, and after stirring, the emulsion was allowed to stand at 50°C for 1 hour to carry out a hydrosilylation reaction. Subsequently, 12 parts by mass of 28% aqueous ammonia was added. The pH of the solution at this stage was 11. The mixture was stirred for an additional 5 hours to carry out a condensation reaction, yielding a uniform aqueous suspension of silicone resin-coated silicone elastomer particles. This aqueous suspension was then dried in an airflow dryer (Seishin Enterprise, model number: FJD-2B) to yield silicone resin-coated silicone elastomer particles. The resulting silicone elastomer particles had a JIS-A hardness of 10 and a JIS-E hardness of 25.

[0118] [Preparation Example 10] 31 parts by mass of a polyorganosiloxane represented by the average formula [Chemical Formula 1-2], 29 parts by mass of a polyorganosiloxane represented by the average formula [Chemical Formula 2-3], and 40 parts by mass of a dimethylpolysiloxane represented by [Chemical Formula 3-1] were uniformly mixed at room temperature. 12.6 parts by mass of a condensation reaction product of tetraethoxysilane (an oligomer mixture with an average pentamer) and 5.4 parts by mass of dimethyldimethoxysilane were added and further mixed. Next, this composition was dispersed in an aqueous solution at 25 °C consisting of 1.7 parts by mass of polyoxyethylene sorbitan laurate, 0.3 parts by mass of polyoxyalkylene alkyl ester, and 60 parts by mass of pure water, and further uniformly emulsified using a colloid mill. The average primary particle diameter was 5.3 μm. Subsequently, 370 parts by mass of pure water was added to dilute the emulsion. Next, an isopropyl alcohol solution of chloroplatinic acid (in an amount that would result in 10 ppm platinum metal by mass in the composition) was added to the emulsion with polyoxyethylene sorbitan laurate and pure water to form an aqueous dispersion, and the resulting mixture was stirred. The emulsion was then allowed to stand at 50°C for 1 hour to allow for a hydrosilylation reaction. The aqueous suspension was then cooled to 10-15°C, after which 35 parts by mass of 28% aqueous ammonia was added. The pH of the resulting solution was 11. While cooling and stirring, 6.2 parts by mass of glycidoxypropyl(methyl)dimethoxysilane was slowly added dropwise over 20 minutes or more, and the mixture was stirred at this temperature for a total of 3 hours. The liquid temperature was then raised to 50°C, and the mixture was stirred for 5 hours to allow for a condensation reaction, resulting in the preparation of a uniform aqueous suspension of silicone rubber particles coated with silicone resin. This aqueous suspension was then dried in an airflow dryer (Seishin Enterprise, Model: FJD-2B) to obtain silicone resin-coated silicone elastomer particles. The resulting silicone elastomer particles had a JIS-A hardness of 8 and a JIS-E hardness of 23.

[0119] [Preparation Example 11] 90.7 parts by mass of a polyorganosiloxane represented by the average formula [Chemical Formula 1-3], 0.4 parts by mass of a polyorganosiloxane represented by the average formula [Chemical Formula 2-1], and 8.9 parts by mass of a polyorganosiloxane represented by the average formula [Chemical Formula 2-2] were uniformly mixed at room temperature. 24.5 parts by mass of a condensation reaction product of tetraethoxysilane (an oligomer mixture with an average pentamer) and 10.5 parts by mass of dimethyldimethoxysilane were added and further mixed. Next, this composition was dispersed in an aqueous solution at 25 ° C. consisting of 2.1 parts by mass of polyoxyethylene sorbitan laurate, 0.3 parts by mass of polyoxyalkylene alkyl ester, and 40 parts by mass of pure water, and further uniformly emulsified using a colloid mill. The average primary particle diameter was 4.2 μm. Then, 680 parts by mass of pure water was added to dilute the mixture to prepare an emulsion. Next, an isopropyl alcohol solution of chloroplatinic acid (in an amount that would result in 10 ppm platinum metal by mass in the composition) was added to the emulsion with polyoxyethylene sorbitan laurate and pure water to form an aqueous dispersion, and the resulting dispersion was stirred. The emulsion was then allowed to stand at 50°C for 1 hour to allow for a hydrosilylation reaction. The aqueous suspension was then cooled to 10-15°C, after which 40 parts by mass of 28% aqueous ammonia was added. The pH of the resulting solution was 11. While cooling and stirring, 7.0 parts by mass of glycidoxypropyl(methyl)dimethoxysilane was slowly added dropwise over 20 minutes or more, and the mixture was stirred at this temperature for a total of 3 hours. The solution temperature was then raised to 50°C, and the mixture was stirred for 5 hours to allow for a condensation reaction, resulting in a uniform aqueous suspension of silicone rubber particles coated with silicone resin. This aqueous suspension was then dried in an airflow dryer (Seishin Enterprise, Model: FJD-2B) to obtain silicone resin-coated silicone elastomer particles. The resulting silicone elastomer particles had a JIS-A hardness of less than 8 and a JIS-E hardness of 7.

[0120] [Preparation Example 12] 88.2 parts by mass of a polyorganosiloxane represented by the average formula [Chemical Formula 1-3], 0.1 parts by mass of a polyorganosiloxane represented by the average formula [Chemical Formula 2-1], and 11.7 parts by mass of a polyorganosiloxane represented by the average formula [Chemical Formula 2-2] were uniformly mixed at room temperature. 24.5 parts by mass of a condensation reaction product of tetraethoxysilane (an oligomer mixture with an average pentamer) and 10.5 parts by mass of dimethyldimethoxysilane were added and further mixed. Next, this composition was dispersed in an aqueous solution at 25 ° C. consisting of 2.1 parts by mass of polyoxyethylene sorbitan laurate, 0.3 parts by mass of polyoxyalkylene alkyl ester, and 40 parts by mass of pure water, and further uniformly emulsified using a colloid mill. The average primary particle diameter was 3.9 μm. Then, 630 parts by mass of pure water was added to dilute the mixture to prepare an emulsion. Next, an isopropyl alcohol solution of chloroplatinic acid (in an amount that would result in 10 ppm platinum metal by mass in the composition) was added to the emulsion with polyoxyethylene sorbitan laurate and pure water to form an aqueous dispersion, and the resulting dispersion was stirred. The emulsion was then allowed to stand at 50°C for 1 hour to allow for a hydrosilylation reaction. The aqueous suspension was then cooled to 10-15°C, after which 30 parts by mass of 28% aqueous ammonia was added. The pH of the resulting solution was 11. While cooling and stirring, 7.0 parts by mass of glycidoxypropyl(methyl)dimethoxysilane was slowly added dropwise over 20 minutes or more, and the mixture was stirred at this temperature for a total of 3 hours. The liquid temperature was then raised to 50°C, and the mixture was stirred for 5 hours to allow for a condensation reaction, resulting in the preparation of a uniform aqueous suspension of silicone rubber particles coated with silicone resin. This aqueous suspension was then dried in an airflow dryer (Seishin Enterprise, Model: FJD-2B) to obtain silicone resin-coated silicone elastomer particles. The resulting silicone elastomer particles had a JIS-A hardness of less than 8 and a JIS-E hardness of 3. [Preparation Example 13] 95.8 parts by mass of a polyorganosiloxane represented by the average formula [Chemical Formula 1-3] and 4.2 parts by mass of a polyorganosiloxane represented by the average formula [Chemical Formula 2-1] were uniformly mixed at room temperature. Next, this composition was dispersed in a 25°C aqueous solution consisting of 0.5 parts by mass of polyoxyalkylene alkyl ester and 33 parts by mass of pure water, and further uniformly emulsified using a colloid mill. The average primary particle size was 5.0 μm.The emulsion was then diluted with 600 parts by weight of pure water to prepare an emulsion. Next, an isopropyl alcohol solution of chloroplatinic acid (in an amount that would result in 10 ppm platinum metal by weight in the composition) was added to polyoxyethylene sorbitan laurate and pure water to prepare an aqueous dispersion. This dispersion was then added to the emulsion and stirred. The emulsion was then allowed to stand at 25°C for 3 hours to allow for the hydrosilylation reaction, after which the aqueous suspension was heated to 65°C and aged for 1 hour. After aging, the suspension was further heated to 85°C and held for an additional hour to complete the hydrosilylation and residual SiH reaction, producing a uniform aqueous suspension of silicone rubber particles. The aqueous suspension was then dried in an airflow dryer (Seishin Enterprise, FJD-2B) to obtain silicone elastomer particles. The resulting silicone elastomer particles had a JIS-A hardness of 33 and a JIS-E hardness of 43.

[0121]

[0122] <Preparation of Epoxy Resin Compositions> Examples 1 to 12 and Comparative Examples 1 to 3: A mixture was obtained by mixing the components in the amounts (parts by mass) shown in Table 2 at room temperature using a mixer. The mixture was then heated and kneaded at a temperature of 70°C or higher and 110°C or lower. The mixture was then cooled to room temperature to obtain a curable epoxy resin composition. Details of each raw material component are as follows: (Epoxy resins) Epoxy resin 1: biphenyl-type epoxy resin (Mitsubishi Chemical Corporation, product number: YX-4000H) Epoxy resin 2: mixture of trisphenylmethane-type epoxy resin (75% by mass) and biphenyl-type epoxy resin (25% by mass) (Mitsubishi Chemical Corporation, product number: YL6677) (Curing agent) Curing agent 1: trisphenylmethane-type phenolic resin (Air Water Inc., HE910-20) (Inorganic filler) Inorganic filler 1: spherical silica with an average particle size of 19 μm (Nippon Steel Sumikin Materials Co., Ltd., Micron Company, product number: S430-5) Inorganic filler 2: spherical silica with an average particle size of 0.5 μm (Admatechs Co., Ltd., product number: SC-2500-SQ) Inorganic filler 3: spherical silica with an average particle size of 1.5 μm (Admatechs Co., Ltd., product number: SC-5500-SQ) (Coupling agent) Coupling agent 1: N-phenyl-3-aminopropyltrimethoxysilane (Dow-Toray Industries, Inc., Z-6883) (curing accelerator) Curing accelerator 1: 2,3-dihydroxynaphthalene (Tokyo Chemical Industry Co., Ltd.) Curing accelerator 2: triphenylphosphine (Tokyo Chemical Industry Co., Ltd.) (mold release agent) Mold release agent 1: glycerin trimontanic acid ester (Clariant Japan Co., Ltd., Ricorb WE-4) (silicone compound) Silicone resin-coated silicone elastomer particles of Preparation Examples 1 to 13 DOWSIL (registered trademark) FZ-3736 (epoxy polyether-modified silicone manufactured by Dow-Toray Industries, Inc.)

[0123]

[0124] <Evaluation of Mechanical Properties of Cured Products> The prepared curable epoxy resin compositions of each Example and Comparative Example were cured by the following method, and the mechanical properties of the obtained cured products were evaluated. The results are shown in Table 3.

[0125] [Preparation of Cured Products (Compression Molding)] Cured products were prepared using each curable epoxy resin composition listed in Table 2. A mold consisting of upper, middle, and lower molds was used for molding. The middle mold was cut out to a size of 100 mm x 10 mm x 4 mm or 50 mm x 50 mm x 1 mm. An amount of curable epoxy resin composition corresponding to the volume of the cutout in the middle mold placed on the lower mold was placed and sandwiched between the upper mold and molded using a manual hydraulic heating press at a mold temperature of 175°C, 2.4 MPa, and a curing time of 10 minutes to obtain test specimens measuring 100 mm long x 10 mm wide x 4 mm thick or 50 mm x 50 mm x 1 mm. The obtained test specimens were then heat-treated at 175°C for 4 hours and then allowed to cool. Cured products measuring 4 mm x 4 mm x 10 mm were obtained by cutting the long sides of 100 mm x 10 mm x 4 mm cured compositions using a microcutter to a 4 mm width. Cured products for evaluation were prepared in this manner. Unless otherwise specified below, test specimens were prepared under these conditions (compression molding).

[0126] [Linear expansion coefficient of cured product] The linear expansion coefficient of a cured product measuring 4 mm x 4 mm x 10 mm was measured using a thermomechanical analyzer (TMA7100, manufactured by Hitachi High-Tech Science Corporation). The measurement was carried out under conditions of a temperature rise rate of 5°C / min from -30°C to 300°C. The measurement data was analyzed, and the average linear expansion coefficient [ppm / °C] between 0°C and 140°C was defined as CTE1.

[0127] [Bending Strength of Cured Product] A cured product measuring 100 mm in length, 10 mm in width, and 4 mm in thickness was measured for bending strength [MPa (N / mm ２ ) was evaluated.

[0128]

[0129] <Evaluation of wettability of cured products> The cured products of the curable epoxy resin compositions prepared in Examples 1, 5 to 7, 10 to 12, and Comparative Examples 1 and 2 were further subjected to a wettability test by the following method to evaluate their wettability. The results are shown in Table 4.

[0130] [Wettability Test] Pyre-ML (registered trademark) RC-5019 (Sigma-Aldrich) was used as the polyimide varnish. A 5 cm square cured product was molded into a square shape with a thickness of 1 mm, and the surface was polished with a #400 grinding edge. The polyimide varnish was applied to the cured product by spin coating, and after drying at room temperature for one day, the polyimide wettability was evaluated according to the following criteria.

[0131] -Evaluation criteria- A: No repellency B: 5 or fewer defective areas such as repellency C: 5 or more defective areas

[0132]

[0133] <Evaluation of molding shrinkage of cured products> The molding shrinkage of the cured products of the curable epoxy resin compositions prepared in Examples 4 and 5 and Comparative Examples 1 and 3 was further evaluated by the following method. The results are shown in Table 5.

[0134] [Molding Shrinkage] Using a transfer molding machine, a curable epoxy resin composition was injected into a mold cavity under conditions of a mold temperature of 175°C, a molding pressure of 9.8 MPa, and a curing time of 4 minutes to prepare a disk-shaped first test piece. The first test piece was then cooled to 25°C. The molding shrinkage S was calculated as follows from the inner diameter of the mold cavity at 175°C and the outer dimensions of the first test piece at 25°C. １ (%) was calculated. １ = {(inner diameter dimension of mold cavity at 175°C) - (outer diameter dimension of first test piece at 25°C)} / (inner diameter dimension of mold cavity at 175°C) × 100

[0135] The first test piece was then post-cured in an oven at 175°C for 4 hours to prepare a second test piece. The second test piece was then cooled to 25°C. The mold shrinkage S was calculated from the inner diameter of the mold cavity at 175°C and the outer dimensions of the second test piece at 25°C as follows: ２ (%) was calculated. ２ = {(inner diameter dimension of mold cavity at 175°C) - (outer diameter dimension of second test piece at 25°C)} / (inner diameter dimension of mold cavity at 175°C) × 100

[0136]

[0137] As shown in Table 3, when curable epoxy resin compositions containing silicone elastomer particles coated with a silicone resin (Examples 1 to 12) were evaluated, CTE1 was reduced without sacrificing flexural strength compared to a curable epoxy resin composition without a silicone additive (Comparative Example 1). This is thought to be due to the inherent flexibility of the silicone elastomer particles, which suppressed the thermal expansion and contraction of the curable epoxy resin composition through deformation of the silicone elastomer particles. On the other hand, when a curable epoxy resin composition containing a co-modified silicone compound (Comparative Example 2) was used, CTE1 was slightly reduced, but flexural strength was significantly reduced. Furthermore, as shown in Table 4, when polyimide wettability was evaluated using curable epoxy resin compositions containing silicone elastomer particles coated with a silicone resin (Examples 1, 5 to 7, and 10 to 12), no repellency of polyimide varnish was observed, as with the curable epoxy resin composition without a silicone additive (Comparative Example 1). On the other hand, the curable resin composition containing a co-modified silicone compound (Comparative Example 2) exhibited repellency of polyimide varnish. This is thought to be because, unlike co-modified silicone compounds, the silicone elastomer particles do not bleed out onto the surface of the curable epoxy resin composition. Furthermore, as shown in Table 5, in the evaluation of mold shrinkage, the curable resin compositions containing silicone elastomer particles coated with silicone resin (Examples 4 and 5) had lower mold shrinkage S1 and S2 than Comparative Examples 1 and 3, achieving favorable results. On the other hand, the curable resin composition containing existing silicone elastomer particles not coated with silicone resin (Comparative Example 3) and the curable epoxy resin composition not containing a silicone additive (Comparative Example 1) showed insufficient reductions in mold shrinkage S1 and S2. Note that while the evaluation of each example was intended to seal semiconductor packages and the like, the results are also applicable to underfills and other resin compositions.

[0138] According to the present invention, an epoxy resin composition is provided which, after encapsulation, allows the support to maintain sufficient strength while suppressing thermal expansion and making it less susceptible to molding shrinkage, thereby suppressing warpage of semiconductors and other products comprising the cured product, and which has excellent polyimide wettability. Because the epoxy resin composition does not contain a volatile solvent, it is useful for the production of various semiconductor devices, such as for encapsulating semiconductor packages.

Claims

1. An epoxy resin composition comprising silicone elastomer particles and silicone resin-coated silicone elastomer particles comprising a silicone resin coating that coats a portion or all of the surface of the silicone elastomer particles, wherein the silicone elastomer particles have a structure in which at least two silicon atoms are crosslinked by a silalkylene group having 2 to 20 carbon atoms, and the silicone resin coating comprises: i) R ３ SiO １／２ (R is a monovalent organic group) ２ SiO ２／２ (R is a monovalent organic group), and iii) a D siloxane unit represented by RSiO ３／２ (R is a monovalent organic group), and iv) SiO ４／２ and one or more silicone resins selected from the group consisting of one or a combination of two or more Q siloxane units represented by the following formula (excluding silicone resins consisting only of T siloxane units), wherein the epoxy resin composition does not contain a volatile solvent.

2. The silicone resin coating is SiO ４ / ２ 2. The epoxy resin composition of claim 1, comprising a Q siloxane unit represented by:

3. The epoxy resin composition according to claim 1, wherein the average primary particle size measured by a laser diffraction scattering method is 0.1 to 100 μm.

4. The epoxy resin composition according to claim 1, wherein the silicone resin-coated silicone elastomer particles do not contain an ionic surfactant.

5. The epoxy resin composition according to claim 1, wherein the silicone elastomer particles in a state not coated with the silicone resin coating have a JIS-A hardness of 80 or less and a JIS-E hardness of 1 or more, as measured by curing the uncured crosslinkable composition for forming silicone elastomer particles into a sheet.

6. The silicone resin coating is R １ ２ SiO ２／２ (R １ are independently a D siloxane unit represented by an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, an alkyl group having 1 to 20 carbon atoms and an epoxy group, or an aryl group having 6 to 20 carbon atoms and an epoxy group), and SiO ４／２ and a DQ silicone resin comprising a Q siloxane unit represented by the formula:

7. The epoxy resin composition according to claim 1, wherein the crosslinkable composition for forming silicone elastomer particles before curing, for silicone elastomer particles not coated with the silicone resin coating, comprises: (a) an organopolysiloxane having at least two alkenyl groups having 2 to 20 carbon atoms per molecule; (b) an organohydrogenpolysiloxane having at least two hydrogen atoms bonded to silicon atoms per molecule; and (c) a hydrosilylation reaction catalyst; and the molar ratio of the content of alkenyl groups (Alk (mol)) in component (a) to the content of hydrogen atoms bonded to silicon atoms (H (mol)) in component (b) is in the range of H / Alk = 0.5 to 1.

5.

8. A cured product obtained by curing the epoxy resin composition according to claim 7.

9. A semiconductor device comprising the cured product according to claim 8.

10. A method for manufacturing a semiconductor device, comprising curing the epoxy resin composition according to claim 7.

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