Thermosetting resin composition

Abstract

The present application provides a thermosetting resin composition, which can make the obtained cured product low-modulus even if the thermosetting resin component contains an organic solvent and / or has a high curing temperature. The thermosetting resin composition contains 1 to 35 parts by mass of (B) spherical polymethylphenylsilsesquioxane particles having a volume average particle diameter of 0.1 to 30 μm, with respect to 100 parts by mass of (A) a thermosetting resin, the polymethylphenylsilsesquioxane particles having a molar ratio of units represented by CH3SiO 3 / 2 and units represented by C6H5SiO 3 / 2 of 95:5 to 55:45. 3 / 2 units: C6H5SiO 3 / 2 units).

Description

Technical Field

[0001] This invention relates to thermosetting resin compositions, and more particularly to thermosetting resin compositions suitable as encapsulants for electronic and electrical components or for printed circuit boards. Background Technology

[0002] In recent years, the miniaturization of electronic devices such as mobile phones or smartphones, ultra-thin LCD TVs, and lightweight laptops has been a driving force. Consequently, electronic components used in these devices are moving towards higher-density integration and further higher-density packaging. Furthermore, resin materials used in these electronic components are required to have a low modulus of elasticity to prevent breakage due to stress caused by the thermal expansion of the components. Additionally, resin materials used in printed circuit boards for mobile devices also require a low modulus of elasticity to prevent breakage from impacts.

[0003] It has been disclosed that by incorporating silicone rubber particles into an epoxy resin composition, the elastic modulus of the cured composition is reduced, thereby reducing stress (Patent Document 1). However, when the thermosetting resin component contains organic solvents, there is a problem that the silicone rubber particles swell due to the organic solvents, which adversely affects the moldability. In addition, if the curing temperature of the thermosetting resin component is higher than the decomposition temperature of the silicone rubber particles, the silicone rubber particles are unsuitable for use.

[0004] On the other hand, it is combined with the structure RSiO 3 / 2 An epoxy resin composition of polyorganosilsesquioxane particles, represented by (R being an organic substituent), has been disclosed (Patent Document 2). Patent Document 2 exemplifies an example with the structural formula CH3SiO. 3 / 2 The polymethylsilsesquioxane particles described do not swell in organic solvents and have a higher decomposition temperature than silicone rubber particles, but the resin has poor low-stressing properties. Patent Document 2 illustrates a resin with the structural formula C6H5SiO. 3 / 2 The polyphenylsilsesquioxane particles represented here, although having a higher decomposition temperature than silicone rubber particles, are soluble in organic solvents. Patent Document 2 illustrates a particle composed of CH3SiO2. 3 / 2 The unit represented by C6H5SiO 3 / 2 The unit represented is composed of CH3SiO 3 / 2 Unit and C6H5SiO 3 / 2 Although polymethylphenyl silsesquioxane particles with a molar ratio of 1:1 do not swell in organic solvents and have a higher decomposition temperature than silicone rubber particles, and also have the low stress-reduction properties of resins, the high cohesiveness of these particles leads to problems such as adhering to the walls of the manufacturing equipment and poor dispersibility of the resin.

[0005] Prior Art Documents

[0006] Patent Documents

[0007] [Patent Document 1] Japanese Patent Application Laid-Open (JP A) No. 2013-104029

[0008] [Patent Document 2] Japanese Patent Application Laid-Open (JP A) No. 61-160955 SUMMARY

[0009] PROBLEMS TO BE SOLVED BY THE INVENTION

[0010] Therefore, an object of the present application is to provide a thermosetting resin composition, which can provide a cured product having a low elastic modulus even if the thermosetting resin component contains an organic solvent and / or has a high curing temperature.

[0011] METHOD FOR SOLVING THE PROBLEM

[0012] The present inventors have intensively studied to achieve the above object, and as a result, have found that the following thermosetting resin composition can achieve the above object by using a specific polymethylphenylsilsesquioxane particle having a low coagulability, thereby completing the present application. [1]

[0014] A thermosetting resin composition comprising: (A) a thermosetting resin, and

[0015] 1 to 35 parts by mass of (B) a spherical polymethylphenylsilsesquioxane particle having a volume average particle diameter of 0.1 to 30 μm, relative to 100 parts by mass of the (A) thermosetting resin;

[0016] the molar ratio of units represented by CH3SiO 3 / 2 to units represented by C6H5SiO 3 / 2 in the polymethylphenylsilsesquioxane particle is 95:5 to 55:45. 3 / 2 Units: C6H5SiO 3 / 2 Units). [2]

[0018] The thermosetting resin composition according to [1], comprising:

[0019] (A) a thermosetting resin, and

[0020] 1 to 35 parts by mass of (B) a spherical polymethylphenylsilsesquioxane particle having a volume average particle diameter of 0.1 to 30 μm, relative to 100 parts by mass of the (A) thermosetting resin. The polymethylphenylsilsesquioxane particle consists of units represented by CH3SiO 3 / 2 to units represented by C6H5SiO 3 / 2 in the polymethylphenylsilsesquioxane particle is 95:5 to 55:45.3 / 2 units and C6H5SiO 3 / 2 molar ratio of the units (CH3SiO 3 / 2 units: C6H5SiO 3 / 2 units) is 95:5 to 55:45. [3]

[0022] The thermosetting resin composition according to [1] or [2], wherein the thermal decomposition temperature of the spherical polymethylphenylsilsesquioxane particles of the component (B) is 400°C or higher, as measured using a thermogravimetric measurement device under an air atmosphere and at a temperature increase rate of 10°C / minute. [4]

[0024] The thermosetting resin composition according to any one of [1] to [3], wherein the thermosetting resin of the component (A) is one or more selected from the group consisting of an epoxy resin, a phenol resin, a cyanate ester resin, and a maleimide resin. [5]

[0026] A cured product, which is a cured product of the thermosetting resin composition according to any one of [1] to [4].

[0027] Effects of the Invention

[0028] Since the thermosetting resin in the thermosetting resin composition of the present application can be low-elastic modulus even if it contains an organic solvent and / or has a high curing temperature, the composition can be used as an encapsulant for electronic parts, electrical parts, or printed circuit boards. DETAILED DESCRIPTION

[0029] Hereinafter, the present application will be described in detail.

[0030] [Component (A)]

[0031] The component (A) is a thermosetting resin, which is not particularly limited as long as it is a component used for an encapsulant for electronic parts, electrical parts, or printed circuit boards, and examples thereof include an epoxy resin, a phenol resin, a cyanate ester resin, a maleimide resin, and the like. These resins can be used alone or in combination of two or more.

[0032] As the epoxy resin, there is no particular limitation, and examples include bisphenol A type epoxy resins, bisphenol F type epoxy resins, bisphenol E type epoxy resins, bisphenol S type epoxy resins, bisphenol Z type epoxy resins (4,4'-cyclohexanediene bisphenol type epoxy resins), bisphenol P type epoxy resins (4,4'-(l,4-phenylene diisoprene) bisphenol type epoxy resins), bisphenol M type epoxy resins (4,4'-(l,3-phenylene diisoprene) bisphenol type epoxy resins), and the like; novolak type epoxy resins, cresol novolak type epoxy resins, and the like; naphthalene skeleton-modified epoxy resins, methoxynaphthalene-modified cresol novolak type epoxy resins, methoxynaphthalene dimethylene type epoxy resins, and the like; biphenyl type epoxy resins; xylylene type epoxy resins; phenol aralkyl type epoxy resins; biphenyl aralkyl type epoxy resins; biphenyl dimethylene type epoxy resins; aralkyl type epoxy resins such as triphenol methane novolak type epoxy resins; anthracene type epoxy resins; phenoxy type epoxy resins; dicyclopentadiene type epoxy resins; norbornene type epoxy resins; adamantane type epoxy resins; fluorene type epoxy resins; halogenated epoxy resins of the above-mentioned epoxy resins, and the like. One of these can be used alone, two or more of these can be used in combination, or one or two or more of these and a prepolymer thereof can be used in combination.

[0033] As the phenol resin, there is no particular limitation, and examples include phenol novolak resins, alkylphenol novolak resins, bisphenol A novolak resins, dicyclopentadiene type phenol resins, Xylok novolak resins, terpene-modified phenol resins, and polyvinyl phenol resins, and the like. One of these can be used alone, two or more of these can be used in combination, or one or two or more of these and a prepolymer thereof can be used in combination.

[0034] As the cyanate ester resin, there is no particular limitation, and examples include novolak type cyanate ester resins, bisphenol A type cyanate ester resins, bisphenol E type cyanate ester resins, tetramethyl bisphenol F type cyanate ester resins, and the like; and naphthol aralkyl type cyanate ester resins, and the like. One of these can be used alone, two or more of these can be used in combination, or one or two or more of these and a prepolymer thereof can be used in combination.

[0035] As the maleimide resin, there is no particular limitation, and examples include N,N'-(4,4'-diphenylmethane) bismaleimide, bis(3-ethyl-5-methyl-4-maleimide phenyl)methane, 2,2-bis[4-(4-maleimide phenoxy)phenyl]propane, and the like. One of these can be used alone, two or more of these can be used in combination, or one or two or more of these and a prepolymer thereof can be used in combination. Further, one or two or more maleimide resins other than the above-mentioned maleimide resins can be used in combination.

[0036] [(B) component]

[0037] The (B) component is a spherical polymethylphenylsilsesquioxane particle having a volume average particle diameter of 0.1 to 30 μm. The volume average particle diameter is preferably 0.5 to 10 μm, more preferably 1 to 5 μm. If the volume average particle diameter is less than 0.1 μm, the coagulation property becomes high, making it difficult to produce the particle and to handle the particle, and thus it is difficult to uniformly disperse the particle in the composition. If the volume average particle diameter exceeds 30 μm, the low stress property of the cured product of the composition is reduced.

[0038] Note that, in the present specification, the volume average particle diameter (MV value) is a value measured according to the resistance method. Also, the "spherical" in the present specification means not only a true spherical shape but also a near spherical shape. It also means a deformed ellipsoid, for example, in which the length of the average longest axis / the length of the shortest axis (aspect ratio) is generally in the range of 1 to 4, preferably in the range of 1 to 2, more preferably in the range of 1 to 1.6, further preferably in the range of 1 to 1.4. The shape of the particle can be confirmed by observation under an optical microscope and an electron microscope. Also, the dispersibility of the particle diameter can be either monodisperse or polydisperse.

[0039] The molar ratio of the units represented by CH3SiO 3 / 2 and the units represented by C6H5SiO 3 / 2 in the spherical polymethylphenylsilsesquioxane particle of the (B) component (CH3SiO 3 / 2 units : C6H5SiO 3 / 2 units) is in the range of 95:5 to 55:45, more preferably in the range of 80:20 to 60:40. Also, the spherical polymethylphenylsilsesquioxane particle of the (B) component is preferably composed of the units represented by CH3SiO 3 / 2 and the units represented by C6H5SiO 3 / 2 If the CH3SiO 3 / 2 units in the (B) component exceed 95 mol%, the low stress property of the cured product of the composition is deteriorated. If the C6H5SiO 3 / 2 units in the (B) component exceed 45 mol%, the coagulation property of the particle becomes high, making it difficult to produce the particle and to handle the particle, and thus it is difficult to uniformly disperse the particle in the composition. Also, if the C6H5SiO 3 / 2 units in the (B) component exceed 50 mol%, a part or all of them are dissolved in an organic solvent such as acetone, and thus it is not possible to use in a composition containing the organic solvent.

[0040] The component (B) can also contain R 1 2SiO 2 / 2 units, R 1 3SiO 1 / 2 units, SiO 4 / 2 units, and R 2 SiO 3 / 2 units selected from R 1 2SiO 2 / 2 units, R 1 3SiO 1 / 2 units, SiO 4 / 2 units, and R 2 SiO 3 / 2 The content of one or more units in the above is preferably 0 to 20% of the component (B), more preferably 0 to 10% of the component (B), and further preferably 0 to 5% of the component (B).

[0041] R 1 in the above formula is an organic group having 1 to 20 carbon atoms. As R 1 , for example, alkyl groups such as methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl, and eicosyl; cycloalkyl groups such as cyclobutyl, cyclopentyl, cyclohexyl, and cycloheptyl; aryl groups such as phenyl, tolyl, and naphthyl; aralkyl groups such as benzyl, phenethyl, and β-phenylpropyl; alkenyl groups such as vinyl and allyl; and hydrocarbon groups obtained by substituting a part or all of the hydrogen atoms bonded to the carbon atoms of these groups with atoms such as halogen atoms (fluorine atom, chlorine atom, bromine atom, iodine atom) and / or substituents such as acryloyloxy group, methacryloyloxy group, epoxy group, glycidyl group, amino group, mercapto group, carboxyl group, and the like.

[0042] R 2 in the above formula is a monovalent organic group having 1 to 20 carbon atoms other than methyl and phenyl. As R 2 , groups other than methyl and phenyl among the groups exemplified as R 1 .

[0043] The component (B) is preferably a component having a high thermal decomposition temperature. The reason for this is that the component (B) can be used even in the case where the thermal decomposition temperature is high and the curing temperature of the component (A) is also high. Specifically, the thermal decomposition temperature of the component (B) measured using a thermogravimetric measurement apparatus is preferably 400°C or higher, and more preferably 450°C or higher under the conditions of an air atmosphere and a temperature increase rate of 10°C / minute.

[0044] The (B) component can be produced by a known method.

[0045] For example, first, in an aqueous alkaline solution, one or two or more kinds of methyltrialkoxysilane represented by the general formula CH3Si(OR 3 )3(wherein R 3 is an unsubstituted monovalent hydrocarbon group having 1 to 6 carbon atoms) and phenyltrialkoxysilane represented by the general formula C6H5Si(OR 3 )3(wherein R 3 is an unsubstituted monovalent hydrocarbon group having 1 to 6 carbon atoms) are separately added, and hydrolysis and condensation reactions are carried out, thereby obtaining an aqueous dispersion of particles.

[0046] Alternatively, in an aqueous acidic solution, hydrolysis of one or two or more kinds of methyltrialkoxysilane represented by the general formula CH3Si(OR 3 )3(wherein R 3 is an unsubstituted monovalent hydrocarbon group having 1 to 6 carbon atoms) and phenyltrialkoxysilane represented by the general formula C6H5Si(OR 3 )3(wherein R 3 is an unsubstituted monovalent hydrocarbon group having 1 to 6 carbon atoms) can be carried out, and an alkaline substance is added thereto, and condensation reactions are carried out, thereby obtaining an aqueous dispersion of particles.

[0047] Next, water and by-product alcohol are removed from the aqueous dispersion thus obtained by heating and drying, etc.

[0048] As a result, spherical polymethylphenylsilsesquioxane particles can be obtained.

[0049] In the case where the particles thus obtained are aggregated, the particles can be obtained by crushing with a pulverizer.

[0050] In the above formula, R 3 is an unsubstituted monovalent hydrocarbon group having 1 to 6 carbon atoms. As R 3 , for example, methyl, ethyl, propyl, butyl, pentyl and hexyl can be mentioned. Of these, methyl is preferred.

[0051] The step of obtaining an aqueous dispersion of particles can be produced without forming a gel-like substance, and therefore, of the above two methods, the method in which methyltrialkoxysilane and phenyltrialkoxysilane are added in an aqueous acidic solution, hydrolysis is carried out, and an alkaline substance is added thereto, and condensation reactions are carried out is preferred.

[0052] Further, more preferably, the method includes the following steps (i) to (iv):

[0053] Step (i)

[0054] a hydrolysis reaction is performed by adding methyltrimethoxysilane in water having a pH of 4.0 to 7.0, to obtain a transparent aqueous solution;

[0055] Process (ii)

[0056] a hydrolysis reaction is performed by adding phenyltrimethoxysilane in the transparent aqueous solution obtained in process (i), to obtain a transparent silane aqueous solution;

[0057] Process (iii)

[0058] a mixing solution is obtained by adjusting the temperature of the transparent silane aqueous solution obtained in process (ii) to 0 to 15°C, adding a basic substance or an aqueous solution in which a basic substance is dissolved thereto, and stirring and mixing, and

[0059] Process (iv)

[0060] a process in which the mixing solution obtained in process (iii) is left to stand to precipitate polymethylphenylsilsesquioxane particles.

[0061] In the above process (i) and process (ii), the total amount of methyltrimethoxysilane and phenyltrimethoxysilane is preferably 5 to 30 parts by mass with respect to 100 parts by mass of water.

[0062] In the thermosetting resin composition of the present application, the content of the (B) component is 1 to 35 parts by mass, preferably 2 to 25 parts by mass, and more preferably 3 to 20 parts by mass, with respect to 100 parts by mass of the (A) component. If the content of the (B) component is less than 1 part by mass with respect to 100 parts by mass of the (A) component, the low stress property of the cured product of the composition becomes low, and on the other hand, if the content of the (B) component is more than 35 parts by mass with respect to 100 parts by mass of the (A) component, the strength of the cured product decreases.

[0063] Optional Components

[0064] In the thermosetting resin composition of the present application, components other than the (A) component and the (B) component can be added as necessary without impairing the effects of the present application. Examples of the components include a curing agent (4,4'-diamino-3,3'-dimethyldiphenylmethane, etc.), an inorganic filler (silica, glass fiber, etc.), a synthetic fiber, a curing accelerator (imidazole, triphenylphosphine, quaternary phosphonium salt, etc.), a polymerization initiator, a release agent, a flame retardant, an ion trapping agent, an antioxidant, an adhesion imparting agent, a low stress agent, a colorant, a coupling agent, and an organic solvent.

[0065] It is to be noted that the total amount of the (A) component and the (B) component in the thermosetting resin composition of the present application is preferably 5 to 100 mass%, more preferably 10 to 100 mass%, and further preferably 20 to 100 mass%.

[0066] Manufacturing method

[0067] The thermosetting resin composition of the present application can be obtained by heating and treating the (A) component, the (B) component and optional components while stirring, melting, mixing and dispersing them as necessary. As the device for mixing, stirring and dispersing these components, there is no particular limitation, but a planetary mixer, a three-roll mill, a ball mill, a sand mill, a kneader and the like can be used. In addition, these devices can be used in combination as appropriate. The obtained thermosetting resin composition can be used as a molding material.

[0068] Molding method

[0069] The thermosetting resin composition of the present application can be molded by a known molding method. As the molding method, a transfer molding method or a compression molding method can be exemplified.

[0070] In the transfer molding method, it is preferable to use a transfer molding machine, and molding is performed under conditions of a molding pressure of 5 to 20 N / mm 2 , a molding temperature of 120 to 190°C, a molding time of 30 to 500 seconds, preferably a molding temperature of 150 to 185°C, and a molding time of 30 to 300 seconds.

[0071] In addition, in the compression molding method, it is preferable to use a compression molding machine, and molding is performed under conditions of a molding temperature of 120 to 190°C, a molding time of 30 to 900 seconds, preferably a molding temperature of 130 to 160°C, and a molding time of 120 to 600 seconds.

[0072] Further, in either molding method, post-curing can be performed at 150 to 225°C for 0.5 to 20 hours.

[0073] [Examples]

[0074] Hereinafter, examples and comparative examples are shown, and the present application is specifically explained, but the present application is not limited to the following examples.

[0075] The measurement method of the acetone solubility and the thermal decomposition temperature in the manufacturing example is explained.

[0076] [Measurement of acetone solubility]

[0077] A 5 g sample and 15 g of acetone were weighed out, and the sample and 3 times the amount of acetone were mixed in a 25 mL glass bottle to prepare an acetone suspension. The acetone suspension was shaken for 30 minutes with the cap on. The acetone suspension was filtered with filter paper, and about 2 g of the filtrate was weighed out into an aluminum petri dish, the weight of the dried residue was measured after drying using a dryer at 105°C, and the acetone solubility of the sample (%) was calculated from the weight of the filtrate and the weight of the dried residue. At this time, since the sample was extracted with 3 times the amount of acetone, the dried residue was increased by 3 times, and the acetone solubility (%) was calculated.

[0078] [Measurement of thermal decomposition temperature]

[0079] The thermal decomposition temperature was measured using a thermogravimetric measurement device under an air atmosphere at a temperature increase rate of 10°C / min, and was determined from the change in the weight loss rate.

[0080] [Manufacturing Example 1]

[0081] Ion exchange water was added to a 1 liter glass flask, and the water temperature was set to 20°C. The pH of the ion exchange water was 5.9 at the time of measurement. Stirring was performed by an anchor-shaped stirring blade at a blade rotation rate of 150 rpm, and the temperature rose to 24°C when 95.5 g of methyltrimethoxysilane was added to the glass flask. It became transparent after 3 minutes, and further stirring was performed for 7 minutes. Next, 62.5 g of phenyltrimethoxysilane was added to the glass flask, and stirring was continued while maintaining the temperature at 20 to 25°C, and it became transparent after 50 minutes, and further stirring was performed for 5 minutes. It took 25 minutes to cool to 5°C. Further, a mixed solution of 0.53 g of a 28 mass% ammonia water solution and 2.65 g of ion exchange water was added to the glass flask, and stirring was stopped after 30 seconds of stirring. White turbidity occurred 12 seconds after the stirring was stopped.

[0082] After standing for 3 hours, stirring was started at a blade rotation rate of 150 rpm and heating to 75°C, 38 g of a 28 mass% ammonia water solution was added to the glass flask, and further stirring was performed for 1 hour at a temperature of 73 to 77°C. After cooling to 30°C or less, liquid was removed using a pressure filter, a filter cake was formed, and the filter cake was dried in a hot air circulation dryer at a temperature of 105°C to obtain a dried product.

[0083] When the acetone solubility of the obtained dried product was measured by the above method, it was 0%.

[0084] The obtained dried product was crushed with a jet mill to obtain polymethylphenylsilsesquioxane particles.

[0085] The molar ratio of methylsilsesquioxane units to phenylsilsesquioxane units of the polymethylphenylsilsesquioxane particles obtained was 69:31, calculated from the amounts of methyltrimethoxysilane and phenyltrimethoxysilane of the raw materials.

[0086] The shape of the polymethylphenylsilsesquioxane particles was spherical with an aspect ratio of 1 when observed with an electron microscope. The volume average particle diameter of the polymethylphenylsilsesquioxane particles was 2.1 μm when measured using a resistance method particle size distribution measuring device "Multisizer 3" (manufactured by Beckman Coulter, Inc.). The thermal decomposition temperature was about 500°C when measured by the above method.

[0087] [Manufacturing Example 2]

[0088] 815 g of ion-exchanged water was charged in a 1 liter glass flask, and the water temperature was set to 20°C. The pH of the ion-exchanged water was 5.9 when measured. Stirring was performed by an anchor type stirring blade at a blade rotation speed of 150 rpm, and 77.6 g of methyltrimethoxysilane was charged in the glass flask, and heat was generated, and the temperature rose to 24°C. It became transparent after 3 minutes, and further stirring was performed for 7 minutes. Next, 66.4 g of phenyltrimethoxysilane was charged in the glass flask, and stirring was continued while maintaining the temperature at 20 to 25°C, and it became transparent after 55 minutes, and further stirring was performed for 5 minutes. It was cooled to 5°C in 25 minutes. Further, a mixed solution of 0.54 g of a 28 mass% ammonia water solution and 2.7 g of ion-exchanged water was charged in the glass flask, and stirring was stopped after 20 seconds. White turbidity occurred after 12 seconds from the stop of stirring.

[0089] After standing for 3 hours, stirring was started at a blade rotation speed of 150 rpm and heating to 75°C, and 38 g of a 28 mass% ammonia water solution was added in the glass flask, and further stirring was performed at a temperature of 73 to 77°C for 1 hour. After cooling to 30°C or less, liquid was removed using a pressure filter, a filter cake was formed, and the filter cake was dried in a hot air circulation dryer at a temperature of 105°C, to obtain a dried product.

[0090] The acetone solubility of the obtained dried product was 0% when measured by the above method.

[0091] The obtained dried product was crushed by a jet mill, to obtain polymethylphenylsilsesquioxane particles.

[0092] The molar ratio of methylsilsesquioxane units and phenylsilsesquioxane units of the polymethylphenylsilsesquioxane particles obtained was 63:37, calculated from the amounts of methyltrimethoxysilane and phenyltrimethoxysilane of the raw materials.

[0093] The shape of the polymethylphenylsilsesquioxane particles was spherical with an aspect ratio of 1 when observed with an electron microscope. The volume average particle diameter of the polymethylphenylsilsesquioxane particles was 2.1 μm when measured using a resistance method particle size distribution measuring device "Multisizer 3" (manufactured by Beckman Coulter, Inc.). The thermal decomposition temperature was about 510°C when measured by the above method.

[0094] [Manufacturing Example 3]

[0095] Ion-exchanged water of 789 g was charged in a 1 liter glass flask, and the water temperature was set to 20°C. The pH of the ion-exchanged water was 5.8 when measured. Stirring was performed by an anchor type stirring blade at a blade rotation speed of 150 rpm, and 110.5 g of methyltrimethoxysilane was charged in the glass flask, and heat was generated, and the temperature rose to 24°C. It became a transparent state after 4 minutes, and further stirring was performed for 6 minutes. Next, 59.5 g of phenyltrimethoxysilane was charged in the glass flask, and stirring was continued while maintaining the temperature at 20 to 25°C, and it became a transparent state after 45 minutes, and further stirring was performed for 5 minutes. It was cooled to 5°C over 25 minutes. Further, a mixed solution of 0.52 g of a 28 mass% ammonia water solution and 2.6 g of ion-exchanged water was charged in the glass flask, and stirring was stopped after 30 seconds of stirring. White turbidity occurred after 30 seconds of stopping the stirring.

[0096] After standing for 3 hours, stirring was started at a blade rotation speed of 150 rpm and heating to 75°C, 38 g of a 28 mass% ammonia water solution was added in the glass flask, and further stirring was performed at a temperature of 73 to 77°C for 1 hour. After cooling to 30°C or less, liquid was removed using a pressure filter, a filter cake was formed, and the filter cake was dried in a hot air circulation dryer at a temperature of 105°C, thereby obtaining a dried product.

[0097] The acetone solubility of the obtained dried product was 0% when measured by the above method.

[0098] The obtained dried product was crushed with a jet mill, and polymethylphenylsilsesquioxane particles were obtained.

[0099] The molar ratio of methylsilsesquioxane units and phenylsilsesquioxane units of the polymethylphenylsilsesquioxane particles obtained was 73:27, calculated from the amounts of methyltrimethoxysilane and phenyltrimethoxysilane of the raw materials.

[0100] The shape of the polymethylphenylsilsesquioxane particles was spherical with an aspect ratio of 1 when observed with an electron microscope. The volume average particle diameter of the polymethylphenylsilsesquioxane particles was 2.2 μm when measured using a resistance method particle size distribution measuring device "Multisizer 3" (manufactured by Beckman Coulter, Inc.). The thermal decomposition temperature was about 490°C when measured by the above method.

[0101] [Manufacturing Example 4]

[0102] 772 g of ion-exchanged water was charged in a 1 liter glass flask, and the water temperature was set to 20°C. The pH of the ion-exchanged water was 5.9 when measured. Stirring was performed by an anchor type stirring blade at a blade rotation speed of 150 rpm, and 113.1 g of methyltrimethoxysilane was charged in the glass flask, and heat was generated, and the temperature rose to 25°C. It became transparent after 3 minutes, and further stirring was performed for 7 minutes. Next, 73.9 g of phenyltrimethoxysilane was charged in the glass flask, and stirring was continued while maintaining the temperature at 20 to 25°C, and it became transparent after 45 minutes, and further stirring was performed for 5 minutes. It was cooled to 5°C in 25 minutes. Further, a mixed solution of 0.53 g of a 28 mass% ammonia water solution and 2.65 g of ion-exchanged water was charged in the glass flask, and stirring was stopped after 30 seconds. White turbidity occurred after 12 seconds from the stop of stirring.

[0103] After standing for 3 hours, stirring was started at a blade rotation speed of 150 rpm and heating was performed to 75°C, and 38 g of a 28 mass% ammonia water solution was added in the glass flask, and further stirring was performed at a temperature of 73 to 77°C for 1 hour. After cooling to 30°C or less, liquid was removed using a pressure filter, a filter cake was formed, and the filter cake was dried in a hot air circulation drier at a temperature of 105°C, and a dried product was obtained.

[0104] The acetone solubility of the obtained dried product was 0% when measured by the above method.

[0105] The obtained dried product was crushed by a jet mill, and polymethylphenylsilsesquioxane particles were obtained.

[0106] The molar ratio of methylsilsesquioxane units to phenylsilsesquioxane units of the polymethylphenylsilsesquioxane particles obtained was 69:31, calculated from the amounts of methyltrimethoxysilane and phenyltrimethoxysilane of the raw materials.

[0107] The polymethylphenylsilsesquioxane particles were spherical with an aspect ratio of 1 when observed with an electron microscope. The volume average particle diameter of the polymethylphenylsilsesquioxane particles was 3.6 μm when measured using a resistance method particle size distribution measuring device "Multisizer 3" (manufactured by Beckman Coulter). The thermal decomposition temperature was about 500°C when measured by the above method.

[0108] [Manufacture Example 5] Comparative Product

[0109] Ion exchange water was added to a 1 liter glass flask, and the water temperature was set to 20°C. The pH of the ion exchange water was 5.9 when measured. Stirring was performed by an anchor type stirring blade at a blade rotation speed of 150 rpm, and a heat was generated when 133 g of methyltrimethoxysilane was put into the glass flask, and the temperature rose to 24°C. It became a transparent state after 3 minutes, and further stirring was continued for 90 minutes while maintaining the temperature at 24°C. Next, a mixed solution of 1.0 g of a 28 mass% ammonia water solution and 5.0 g of ion exchange water was put into the glass flask, and the stirring was stopped after 30 seconds. The white turbidity occurred after 110 seconds from the stop of the stirring.

[0110] After standing for 1 hour, the stirring was started at a blade rotation speed of 150 rpm and heated to 75°C, and further 37 g of a 28 mass% ammonia water solution was added to the glass flask, and further stirring was performed at a temperature of 73 to 77°C for 1 hour. After cooling to 30°C or less, the liquid was removed using a pressure filter, a filter cake was formed, and the filter cake was dried in a hot air circulation drier at a temperature of 105°C to obtain a dried product.

[0111] The acetone solubility of the obtained dried product was 0% when measured by the above method.

[0112] The obtained dried product was crushed by a jet mill to obtain polymethylsilsesquioxane particles composed only of methylsilsesquioxane units.

[0113] The shape of the polymethylsilsesquioxane particles was observed by electron microscopy, and was found to be spherical with an aspect ratio of 1. The volume average particle diameter of the polymethylphenylsilsesquioxane particles was measured using a resistance method particle size distribution measuring device "Multisizer 3" (manufactured by Beckman Coulter, Inc.), and was found to be 2.1 μm. The thermal decomposition temperature was measured by the above method, and was found to be about 430°C.

[0114] [Comparative Example 6]

[0115] The ion exchange water was added to a 1 liter glass flask, and the water temperature was set to 20°C. The pH of the ion exchange water was 5.9. While stirring by an anchor-type stirring blade at a blade rotation speed of 150 rpm, 60.7 g of methyltrimethoxysilane was added to the glass flask, and heat was generated, and the temperature rose to 25°C. It became transparent after 2 minutes, and further stirring was performed for 8 minutes. Next, 88.3 g of phenyltrimethoxysilane was added to the glass flask, and while continuing the stirring at a temperature of 20 to 25°C, it became transparent after 45 minutes, and further stirring was performed for 5 minutes. It was cooled to 5°C over 25 minutes. Further, a mixed solution of 0.53 g of a 28 mass% ammonia water solution and 2.65 g of ion exchange water was added to the glass flask, and after stirring for 30 seconds, the stirring was stopped. White turbidity occurred 5 seconds after the stirring was stopped.

[0116] After standing for 3 hours, stirring was started at a blade rotation speed of 150 rpm and heating was performed to 75°C, and further 38 g of a 28 mass% ammonia water solution was added to the glass flask, and further stirring was performed at a temperature of 73 to 77°C for 1 hour. After cooling to 30°C or less, liquid was removed using a pressure filter, a filter cake was formed, and the filter cake was dried in a hot air circulation dryer at a temperature of 105°C, to obtain a dried product.

[0117] The amount of acetone solubles was measured for the obtained dried product by the above method, and was found to be 0%.

[0118] Although the obtained dried product was crushed by a jet mill, since the particles had high cohesiveness, it was difficult to perform the crushing treatment. Further, since the above dried product was mostly attached to the inside of the device wall, the amount of the polymethylphenylsilsesquioxane particles that could be recovered was small, and thus it could not be used for evaluation in the following comparative example.

[0119] The molar ratio of the methylsilsesquioxane units and the phenylsilsesquioxane units of the obtained polymethylphenylsilsesquioxane particles was calculated from the amounts of the raw materials, methyltrimethoxysilane and phenyltrimethoxysilane, and was found to be 50:50.

[0120] [Manufacture Example 7] Comparative Product

[0121] 801 g of ion-exchanged water and 19 g of a 28 mass% ammonia aqueous solution were added in a 1 liter glass flask, and the water temperature was set to 20°C. The pH of the ion-exchanged water was 11.4 at the time of measurement. Stirring was performed by an anchor type stirring blade under the condition that the blade rotation speed was 150 rpm, and 180 g of phenyltrimethoxysilane was added dropwise in the glass flask over a period of 3 hours while maintaining the temperature at 20 to 22°C. White turbidity occurred about 20 minutes after the start of the dropwise addition of the phenyltrimethoxysilane.

[0122] After the completion of the dropwise addition of the phenyltrimethoxysilane and after maintaining the temperature at 20 to 22°C, stirring was further performed at a temperature of 73 to 77°C for 1 hour. After cooling to 30°C or less, liquid separation was performed using a pressure filter, a filter cake was formed, and the filter cake was dried in a hot air circulation dryer at a temperature of 105°C, thereby obtaining a dried product.

[0123] Although the obtained dried product was crushed with a jet mill, since the cohesiveness of the particles was very high, it was difficult to perform the crushing treatment, and since the polyphenylsilsesquioxane particles that could be recovered were also small, it could not be used as an evaluation against the following comparative examples.

[0124] In addition, the obtained dried product was a polyphenylsilsesquioxane consisting only of phenylsilsesquioxane units, and when the amount of acetone solubles was measured by the above-described method, it was 100%. From this result, it was clear that it could not be applied to a composition containing an organic solvent.

[0125] [Examples 1 to 6, Comparative Examples 1 to 2]

[0126] Each component (g) was weighed in the composition ratio shown in Table 1, and a planetary mixer was stirred under reduced pressure for 15 minutes, thereby obtaining a thermosetting resin composition. The resin composition was cast in a mold, and cured at 150°C for 4 hours, thereby obtaining a molded product (cured product) that was 10 mm wide, 100 mm long, and 5 mm thick.

[0127] The obtained molded product was used as a test piece, and the flexural modulus and the flexural strength were measured using the method described in JIS K7171:2016. The results are shown in Table 1.

[0128] Table 1

[0129]

[0130] *1 ZX-1059: NIPPON STEEL Chemical & Material Co., Ltd.

[0131] *2 Kayahard A-A: manufactured by Nippon Kayaku Co., Ltd.

[0132] The polymethylphenylsilsesquioxane particles used in Examples 1 to 6 as the (B) component and the polymethylsilsesquioxane particles used in Comparative Example 2 as the non-(B) component did not agglomerate and were uniformly dispersed in the compositions.

[0133] In addition, the elastic modulus of Examples 1 to 6 was lower than that of Comparative Example 1 which did not contain the (B) component or Comparative Example 2 which contained the non-(B) component polymethylsilsesquioxane particles.

[0134] From the above results, it was clear that even if the thermosetting resin ((A) component) contains an organic solvent and / or has a high curing temperature, the elastic modulus of the cured product of a composition containing the (A) component and the (B) component can be reduced by using a specific polymethylphenylsilsesquioxane particle ((B) component). Thus, the thermosetting resin composition of the present application can be used as an encapsulant for electronic and electrical components or a printed circuit board.

Claims

1. A thermosetting resin composition comprising: (A) a thermosetting resin, and 1 to 35 parts by mass of (B) spherical polymethylphenylsilsesquioxane particles having a volume average particle diameter of 0.1 to 30 μm, relative to 100 parts by mass of the (A) thermosetting resin; The polymethylphenylsilsesquioxane particles contain CH3SiO 3 / 2 The unit represented by C6H5SiO 3 / 2 The molar ratio of the units represented, i.e., CH3SiO 3 / 2 Unit: C6H5SiO 3 / 2 The unit is 95:5 to 55:

45.

2. The thermosetting resin composition according to claim 1, comprising: (A) a thermosetting resin, and 1 to 35 parts by mass of (B) spherical polymethylphenylsilsesquioxane particles having a volume average particle diameter of 0.1 to 30 μm, relative to 100 parts by mass of the (A) thermosetting resin; The polymethylphenylsilsesquioxane particles consist of units represented by CH3SiO 3 / 2 and units represented by C6H5SiO 3 / 2 , and the molar ratio of CH3SiO 3 / 2 units to C6H5SiO 3 / 2 units, i.e., CH3SiO 3 / 2 units : C6H5SiO 3 / 2 units, is 95:5 to 55:

45.

3. The thermosetting resin composition according to claim 1, wherein The thermal decomposition temperature of the spherical polymethylphenylsilsesquioxane particles of the (B) component, as determined using a thermogravimetric measurement device under conditions of an air atmosphere and at a temperature increase rate of 10°C / minute, is 400°C or higher.

4. The thermosetting resin composition according to claim 1, wherein, The thermosetting resin of the (A) component is one or more selected from the group consisting of an epoxy resin, a phenol resin, a cyanate ester resin, and a maleimide resin.

5. The thermosetting resin composition according to claim 1, wherein, The volume average particle diameter of the (B) component is 0.5 to 10 μm.

6. The thermosetting resin composition according to claim 1, whose cured product has a low modulus of elasticity using the spherical polymethylphenylsilsesquioxane particles of the (B) component.

7. A cured product, which is a cured product of the thermosetting resin composition according to any one of claims 1 to 6.

8. The cured product according to claim 7, which has a low modulus of elasticity using the spherical polymethylphenylsilsesquioxane particles of the (B) component.

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