Thermosetting composition, method for producing molded article using same, and cured product

Abstract

Disclosed is a thermosetting composition which contains the components (A) to (C) described below, the component (G) described below, and one or more components selected from the group consisting of the components (D) to (F) described below.　(A) a monofunctional or polyfunctional (meth)acrylate compound which has, as an ester substituent, a group having a substituted or unsubstituted alicyclic hydrocarbon group having 6 or more ring carbon atoms, and which has a viscosity of 1-300 mPa∙s at 25°C (B) a spherical silica (C) a white pigment (D) a (meth)acrylic acid or a monofunctional (meth)acrylate compound which has, as an ester substituent, a group having a polar group (E) a monofunctional (meth)acrylate compound which has, as an ester substituent, a group other than the ester substituent of the component (A) and the ester substituent of the component (D) (F) a polyfunctional (meth)acrylate compound which has, as an ester substituent, a group other than the ester substituent of the component (A) (G) a block copolymer which contains at least one block composed of repeating units represented by formula (G1) and at least one block composed of repeating units represented by formula (G2)

Description

Thermosetting composition, method for producing molded article using same, and cured product

[0001] The present invention relates to a thermosetting composition, a method for producing a molded article using the same, and a cured product.

[0002] Light-emitting devices and displays that use optical semiconductors such as light-emitting diodes (LEDs), which have become increasingly popular in recent years, are typically manufactured by integrally molding a synthetic resin as a reflective material (reflector) onto a concave lead frame, fixing an optical semiconductor (LED) onto the resulting molded lead frame, and sealing the resulting molded body with a sealing material such as epoxy resin or silicone resin.

[0003] Patent Document 1 discloses a thermosetting composition containing a (meth)acrylate compound and a white pigment such as titanium oxide and having a predetermined shear viscosity as a material for use in reflectors for optical semiconductors. The thermosetting composition described in Patent Document 1 has high reflectance in the visible light range, excellent whiteness, excellent heat resistance and light resistance, and excellent adhesion to surrounding components (particularly lead frames). Patent Document 1 also discloses that use of the thermosetting composition can suppress the generation of burrs when forming a reflector and provides excellent continuous moldability.

[0004] In recent years, mold array packaging (MAP) using transfer molding has begun to be adopted in the manufacture of semiconductor packages. MAP molding is a manufacturing method in which multiple chips arranged in a matrix are encapsulated together and then diced into individual package pieces. MAP molding offers superior mass productivity compared to individual molding, in which the reflectors of each chip are molded into a beaded shape and the connected portions are cut to separate the individual pieces. MAP molding also allows for a significant cost reduction by increasing the number of chips per unit area of ​​the lead frame metal material integrally molded with the reflector.

[0005] However, in MAP molding, compared to the case of individual molding, warping tends to occur more easily in molded products in which the metal material for the lead frame and the reflective material (reflector) are integrally molded. For this reason, when conventional materials for reflective materials such as those disclosed in Patent Document 1 are used in MAP molding, cracks and chips are likely to occur when the molded product with the lead frame is diced into individual pieces, increasing the rate of defective products and sometimes resulting in a significantly lower number of chips being obtained per unit area of ​​the metal material for the lead frame than expected.

[0006] Japanese Patent Application Laid-Open No. 2016-8230

[0007] An object of the present invention is to provide a thermosetting composition which produces a cured product that is less prone to warping, has excellent moldability, and has high reflectivity and a good appearance, a method for producing a cured product using the same, and the cured product.

[0008] According to the present invention, the following thermosetting compositions and the like are provided: 1. A thermosetting composition comprising the following components (A) to (C) and the following component (G), and one or more selected from the group consisting of the following components (D) to (F): (A) a monofunctional or polyfunctional (meth)acrylate compound having, as an ester substituent, a substituted or unsubstituted group having an alicyclic hydrocarbon group having 6 or more ring carbon atoms, and having a viscosity at 25°C of 1 to 300 mPa·s; (B) spherical silica; (C) a white pigment; (D) a monofunctional (meth)acrylate compound having, as an ester substituent, a group having (meth)acrylic acid or a polar group; (E) a monofunctional (meth)acrylate compound having, as an ester substituent, a group other than the ester substituent of component (A) and the ester substituent of component (D); (F) one or more compounds selected from the group consisting of polyfunctional (meth)acrylate compounds having, as an ester substituent, a group other than the ester substituent of component (A); (G) a block copolymer comprising at least one block consisting of a repeating unit represented by the following formula (G1) and at least one block consisting of a repeating unit represented by the following formula (G2): (In formula (G1), R ４０１ is a hydrogen atom or a methyl group. ４０２ is a hydrogen atom or a methyl group. ４０３represents an alkyl group having 2 to 18 carbon atoms, -R ４１１ OR ４１２ , or -R ４１３ SR ４１４ It is. ４１１ and R ４１３ are each independently an alkylene group having 1 to 30 carbon atoms. ４１２ and R ４１４are each independently an alkyl group having 1 to 30 carbon atoms.) 2. The thermosetting composition according to 1, wherein the content of component (C) is 1 to 20 mass% based on 100 mass% of the total of components (A) to (G). 3. The thermosetting composition according to 1 or 2, wherein the substituted or unsubstituted alicyclic hydrocarbon group of component (A) having 6 or more ring carbon atoms is one or more groups selected from the group consisting of a substituted or unsubstituted adamantyl group, a substituted or unsubstituted norbornyl group, a substituted or unsubstituted isobornyl group, a substituted or unsubstituted tricyclodecanyl group, a substituted or unsubstituted tricyclodecanyl group, and a substituted or unsubstituted dicyclopentanyl group. 4. The thermosetting composition according to any of 1 to 3, wherein component (B) is spherical silica that has been surface-treated with an acrylsilane or a methacrylsilane. 5. 5. The thermosetting composition according to any one of 1 to 4, wherein the average particle size (D50) of component (B) is 0.1 to 100 μm. 6. The thermosetting composition according to any one of 1 to 5, wherein the content of components contained in components (A) and (D) to (F) and having a melting point of -5°C or higher is 40% by mass or more, based on a total of 100% by mass of components (A) and (D) to (F). 7. The thermosetting composition according to any one of 1 to 6, wherein the total content of components (B) to (C) is 85% by mass or less, based on a total of 100% by mass of components (A) to (G). 8. A method for producing a molded product, comprising the steps of: supplying the thermosetting composition according to any one of 1 to 7 into a plunger; filling a molded product portion of a mold with the supplied thermosetting composition using the plunger; heat-curing the filled thermosetting composition in the molded product portion; and extruding the thermoset resin. 8. The method for producing a molded article according to 8 or 9, wherein the temperature of the mold portion constituting the molded article portion is 100 to 180°C. 10. The method for producing a molded article according to 8 or 9, wherein a flow path controlled to a temperature of 50°C or less is provided between the plunger and the molded article portion, and the filling is carried out via the flow path. 11. The method for producing a molded article according to 10, wherein the flow path has a gate system that blocks the flow of the thermosetting composition and the exchange of heat.12. The method for producing a molded article according to 11, wherein the filling is carried out by opening a gate of the gate system, and the heat curing is carried out under pressure, and after the pressure is held, the gate of the gate system is closed to complete the heat curing. 13. The method for producing a molded article according to any one of 8 to 12, wherein the filling step and the heat curing step are carried out for 0.2 to 3 minutes. 14. A cured product produced using the thermosetting composition according to any one of 1 to 7. 15. The cured product according to 14, which is a molded article.

[0009] According to the present invention, there are provided a thermosetting composition which produces a cured product that is less prone to warping, has excellent moldability, and has high reflectivity and a good appearance, as well as a method for producing a cured product using the same and the cured product.

[0010] Fig. 1 is a schematic cross-sectional view of a filling device of a molding machine that can be used in a method for producing a molded article according to one embodiment of the present invention. Fig. 2 is a schematic cross-sectional view of a mold that can be used in a method for producing a molded article according to one embodiment of the present invention. Fig. 3 is a diagram showing the relationship between the viscosity of a thermosetting composition and time in an embodiment of a method for producing a molded article according to one embodiment of the present invention. Fig. 4 is a schematic cross-sectional view showing one embodiment of an optical semiconductor element mounting substrate and an optical semiconductor light emitting device that use a thermosetting composition according to one embodiment of the present invention. Fig. 5 is a schematic cross-sectional view showing another embodiment of an optical semiconductor element mounting substrate and an optical semiconductor light emitting device that use a thermosetting composition according to one embodiment of the present invention.

[0011] In this specification, the "number of carbon atoms XX to YY" in the expression "substituted or unsubstituted ZZ group having carbon atoms XX to YY" represents the number of carbon atoms when the ZZ group is unsubstituted, and does not include the number of carbon atoms of the substituent when the ZZ group is substituted. Here, "YY" is larger than "XX", and "XX" and "YY" each represent an integer of 1 or more.

[0012] In the case of "substituted or unsubstituted," "unsubstituted" means that the group is not substituted with a substituent and has a hydrogen atom bonded thereto.

[0013] In this specification, acrylate and methacrylate are collectively referred to as (meth)acrylate, acrylic acid and methacrylic acid are collectively referred to as (meth)acrylic acid, acrylo and methacrylo are collectively referred to as (meth)acrylo, acrylic and methacrylic are collectively referred to as (meth)acrylic, and acryloyl and methacryloyl groups are collectively referred to as (meth)acryloyl groups.

[0014] In this specification, "x to y" represents a numerical range of "x or more, y or less." When there are multiple lower limit values, such as "x or more," or multiple upper limit values, such as "y or less," for a single technical item, any combination of upper and lower limit values ​​may be selected from the upper and lower limit values.

[0015] 1. Thermosetting Composition A thermosetting composition according to one aspect of the present invention is characterized by comprising the following components (A) to (C) and component (G), and one or more selected from the group consisting of the following components (D) to (F): (A) a monofunctional or polyfunctional (meth)acrylate compound having, as an ester substituent, a substituted or unsubstituted group having an alicyclic hydrocarbon group having 6 or more ring carbon atoms, and having a viscosity at 25°C of 1 to 300 mPa·s; (B) spherical silica; (C) a white pigment; (D) a monofunctional (meth)acrylate compound having, as an ester substituent, a group having (meth)acrylic acid or a polar group; (E) a monofunctional (meth)acrylate compound having, as an ester substituent, a group other than the ester substituent of component (A) and the ester substituent of component (D); (F) a polyfunctional (meth)acrylate compound having, as an ester substituent, a group other than the ester substituent of component (A); (G) a block copolymer comprising at least one block consisting of a repeating unit represented by the following formula (G1) and at least one block consisting of a repeating unit represented by the following formula (G2):

[0016]

[0017] (In formula (G1), R ４０１ is a hydrogen atom or a methyl group. ４０２ is a hydrogen atom or a methyl group. ４０３represents an alkyl group having 2 to 18 carbon atoms, -R ４１１ OR ４１２ , or -R ４１３ SR ４１４ It is. ４１１ and R ４１３ are each independently an alkylene group having 1 to 30 carbon atoms. ４１２ and R ４１４ are each independently an alkyl group having 1 to 30 carbon atoms.

[0018] When the thermosetting composition of this embodiment is thermoset in a state where it is integrally molded with another material such as a metal material, the occurrence of warpage in the resulting cured product (e.g., an LED reflector) is suppressed, which reduces the rate of defective products in molded products containing the cured product (e.g., an integrally molded product of an LED reflector and a lead frame), thereby realizing high production stability.

[0019] The monofunctional (meth)acrylate compound refers to a compound having one (meth)acryloyl group, and the polyfunctional (meth)acrylate compound refers to a compound having two or more (meth)acryloyl groups.

[0020] The ester substituent is R in the following formula (a): １２ It is a group represented by the following formula: (In formula (a), R １１ represents a hydrogen atom or a methyl group.

[0021] Each component of the thermosetting composition of this embodiment will be described below.

[0022] <Component (A)> Component (A) is a monofunctional or polyfunctional acrylate compound or a monofunctional or polyfunctional methacrylate compound having, as an ester substituent, a group having a substituted or unsubstituted alicyclic hydrocarbon group having 6 or more (preferably 6 to 30, and more preferably 7 to 15) ring carbon atoms. Component (A) provides a polymer with a high glass transition point, thereby improving the heat resistance and light resistance of the resulting cured product.

[0023] From the viewpoint of enhancing the packing properties of components (B) and (C), component (A) is used in a viscoelastic composition having a shear rate of 10 s measured at a constant shear rate using a rotational viscometer (JIS K7117-2:1999). －１ The viscosity at a shear rate of 1000 kJ / cm2 at 25° C. is preferably 1 to 300 mPa·s, more preferably 2 to 200 mPa·s, and even more preferably 3 to 100 mPa·s. The viscosity is measured using a viscoelasticity measuring device.

[0024] Examples of the substituted or unsubstituted alicyclic hydrocarbon group of component (A) having 6 or more ring carbon atoms include a substituted or unsubstituted adamantyl group, a substituted or unsubstituted norbornyl group, a substituted or unsubstituted isobornyl group, a substituted or unsubstituted tricyclodecanyl group, a substituted or unsubstituted dicyclopentanyl group, and a cyclohexyl group, with a substituted or unsubstituted adamantyl group, a substituted or unsubstituted norbornyl group, a substituted or unsubstituted isobornyl group, a substituted or unsubstituted tricyclodecanyl group, and a substituted or unsubstituted dicyclopentanyl group being preferred.

[0025] As component (A), compounds represented by the following formulae (I) to (IV) are preferred.

[0026] (In formulas (I), (II), (III) and (IV), R １ each independently represents a hydrogen atom or a methyl group. Each X independently represents a single bond, an alkylene group having 1 to 4 carbon atoms (preferably 1 or 2), or an oxyalkylene group having 1 to 4 carbon atoms (preferably 1 or 2) (preferably a single bond). Each U independently represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms (preferably 1 or 2), a halogen atom, a hydroxyl group, or an ═O group. k represents an integer of 1 to 15. l represents an integer of 1 to 8. m represents an integer of 1 to 11. n represents an integer of 1 to 15. When two or more Us are present, the two or more Us may be the same or different.

[0027] Examples of the alkylene group having 1 to 4 carbon atoms for X include a methylene group, an ethylene group, a trimethylene group, a propylene group, a tetramethylene group, a butylene group, a 2-methyltrimethylene group, etc. Examples of the oxyalkylene group having 1 to 4 carbon atoms for X include an oxymethylene group, an oxyethylene group, an oxypropylene group, an oxybutylene group, etc.

[0028] The ═O group of U is a double-bonded group of an oxygen atom, and can be bonded by removing two hydrogen atoms to a carbon atom from which two hydrogen atoms can be removed in the alicyclic hydrocarbon group of the compounds represented by formulas (I) to (IV). Examples of the alkyl group having 1 to 4 carbon atoms of U include a methyl group, an ethyl group, a propyl group (e.g., an n-propyl group, an isopropyl group), and a butyl group (e.g., an n-butyl group, an isobutyl group). Examples of the halogen atom of U include a fluorine atom, a bromine atom, and an iodine atom.

[0029] From the viewpoint of heat resistance, X is preferably a single bond.

[0030] Component (A) is more preferably adamantyl methacrylate, adamantyl acrylate, cyclohexyl methacrylate, 1-norbornyl methacrylate, 1-isobornyl methacrylate, 1-isobornyl acrylate, 1-dicyclopentanyl methacrylate, adamantyl dimethacrylate, adamantyl diacrylate, tricyclodecane dimethanol dimethacrylate, or tricyclodecane dimethanol diacrylate, and even more preferably 1-adamantyl methacrylate, 1-norbornyl methacrylate, or 1-isobornyl methacrylate.

[0031] The content of component (A) may be 1.0 to 40% by mass, 2.0 to 35% by mass, 3.0 to 33% by mass, or 4.0 to 30% by mass, based on 100% by mass of the total of components (A), (D), and (G). Furthermore, the content of component (A) may be 1.0 to 20% by mass, 1.2 to 15% by mass, 1.5 to 10% by mass, or 1.8 to 8% by mass, based on 100% by mass of the total of components (A) to (G). By having the content of component (A) within the above ranges, the resulting cured product has excellent heat resistance and light resistance and also moderate flexibility. Specifically, the higher the content of component (A), the higher the heat resistance and light resistance of the cured product. Furthermore, the lower the content of component (A), the more effectively the resulting cured product can be prevented from becoming excessively hard, and moderate flexibility can be achieved.

[0032] The component (A) may be used alone or in combination of two or more.

[0033] In this specification, examples of the substituent (hereinafter also referred to as an arbitrary substituent) in the case of "substituted or unsubstituted" include an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a halogen atom, a hydroxyl group, etc. Examples of the alkyl group having 1 to 6 carbon atoms (preferably linear or branched) include a methyl group, an ethyl group, a propyl group (e.g., n-propyl group, isopropyl group), a butyl group (e.g., n-butyl group, isobutyl group, s-butyl group, t-butyl group), a pentyl group (e.g., n-pentyl), a hexyl group, etc. Examples of the alkoxy group having 1 to 6 carbon atoms include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentyloxy group, a hexyloxy group, etc. Examples of the halogen atom include a fluorine atom, a bromine atom, an iodine atom, etc.

[0034] <Component (B)> Component (B) is spherical silica (SiO ２) The inclusion of component (B) can increase the refractive index of the resulting cured product. It can also maintain the fluidity of the thermosetting composition and improve the filling properties during molding. It can also increase the content of component (C), which can further improve the material strength, reflectance, heat resistance, and light resistance.

[0035] The average particle size (D50) of component (B) is, for example, 0.1 to 100 μm, preferably 0.5 to 70 μm, more preferably 1 to 50 μm, and particularly preferably 1 to 16 μm, from the viewpoints of improving filling properties, preventing clogging of molding channels, and ensuring flexibility of the cured product. The average particle size (D50) of component (B) is measured using a laser diffraction particle size distribution analyzer. The average particle size (D50) refers to the median diameter of a cumulative distribution, and means the diameter at which, when divided into two, the larger and smaller sides are equal in amount.

[0036] From the viewpoint of improving wettability and improving the strength of the cured product, component (B) is preferably surface-treated spherical silica, and more preferably spherical silica surface-treated with an acrylsilane or methacrylsilane. The acrylsilane surface treatment or methacrylsilane surface treatment can be carried out using a silane coupling agent. Examples of silane coupling agents include 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane, and 3-acryloxypropyltrimethoxysilane. The time for the acrylsilane surface treatment or methacrylsilane surface treatment is, for example, 30 to 120 minutes.

[0037] Commercially available products that can be used as component (B) include CRS1085-SF630 (manufactured by Tatsumori Co., Ltd.), CRS1035-LER4: spherical silica having an average particle size (D50) of 2 μm (manufactured by Tatsumori Co., Ltd.), S430-5PHM (manufactured by Nippon Steel Chemical & Material Co., Ltd.), SP40HM (manufactured by Nippon Steel Chemical & Material Co., Ltd.), and FB-304HM (manufactured by Denka Company Limited).

[0038] The component (B) may be used alone or in combination of two or more.

[0039] The content of component (B) based on 100% by mass of the total of components (A) to (G) may be 30 to 80% by mass, 40 to 70% by mass, 50 to 68% by mass, or 55 to 67% by mass.

[0040] By having the content of component (B) within the above range, the thermosetting composition can have better fluidity and storage stability at room temperature. Furthermore, the strength of the cured product can be ensured and burrs can be further suppressed. Furthermore, the hardness of the cured product can be prevented from becoming excessively high, and appropriate flexibility can be obtained. When two or more types of component (B) are combined, the content of component (B) is the total of the two or more types.

[0041] <Component (C)> Component (C) is a white pigment. Specific examples of component (C) include barium titanate, zirconium oxide, zinc oxide, boron nitride, titanium dioxide (titanium oxide), alumina, zinc sulfide, magnesium oxide, potassium titanate, barium sulfate, calcium carbonate, and silicone particles. Among these, barium titanate, zirconium oxide, zinc oxide, boron nitride, and titanium dioxide are preferred from the viewpoints of high reflectance and easy availability, and titanium dioxide is preferred from the viewpoint of higher reflectance.

[0042] The crystalline form of titanium dioxide may be rutile or anatase, with the rutile form being preferred from the viewpoint of light resistance.

[0043] From the viewpoint of dispersibility, the primary average particle size of component (C) is preferably 0.01 to 20 μm, more preferably 0.05 to 10 μm, and even more preferably 0.1 to 1 μm. The primary average particle size of component (C) can be measured using a scanning electron microscope. The primary average particle size refers to the average particle size of primary particles. Primary particles are minute solids, and when they aggregate, they tend to stick together with adjacent minute solids due to forces such as static electricity. For this reason, several minute solids may stick together to form secondary particles (aggregated particles or aggregates). In a scanning electron microscope, the primary particles appear in the secondary particles as the smallest constituent units of the secondary particles, resembling millet crackers, and their maximum length can be measured.

[0044] From the viewpoint of improving the refractive index, component (C) may be hollow particles. The gas inside the hollow particles is usually air, but may be an inert gas such as nitrogen or argon, or may be a vacuum.

[0045] Component (C) may be appropriately surface-treated with a silicon compound, an aluminum compound, an organic substance, etc. Examples of surface treatments include (meth)acrylsilane treatment, alkylation treatment, trimethylsilylation treatment, silicone treatment, and treatment with a coupling agent.

[0046] The component (C) may be used alone or in combination of two or more.

[0047] The content of component (C) based on 100% by mass of the total of components (A) to (G) may be 1.0 to 30% by mass, 1 to 20% by mass, 5 to 25% by mass, 10 to 20% by mass, or 12 to 18% by mass.

[0048] By ensuring that the content of component (C) is within the above range, the flowability of the thermosetting composition can be improved, and the cured product can have a high reflectance.

[0049] <Component (D)> Component (D) is a monofunctional acrylate compound or monofunctional methacrylate compound having acrylic acid, methacrylic acid, or a group having a polar group (but other than the ester substituent of component (A)) as an ester substituent. Component (D) has a polar group, which can improve the adhesion and wettability of the resulting cured product to metal components. Obata's statement: It may be unnecessary, but I added the blue text.

[0050] Examples of the polar group include a hydroxyl group, an epoxy group, a glycidyl group, a tetrahydrofurfuryl group, an isocyanate group, a carboxyl group, an alkoxysilyl group, a phosphate ester group, a lactone group, an oxetane group, a tetrahydropyranyl group, and an amino group. Among these, a glycidyl group, a phosphate ester group, a carboxyl group, a glycidyl group, and a lactone group are preferred because they can provide higher adhesion and wettability.

[0051] Specific examples of the monofunctional (meth)acrylate compound having a group having a polar group as an ester substituent include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate (for example, trade name: 4-HBA, manufactured by Nippon Kasei Co., Ltd.), cyclohexanedimethanol mono(meth)acrylate (for example, trade name: CHMMA, manufactured by Nippon Kasei Co., Ltd.), glycidyl (meth)acrylate, 4-hydroxybutyl acrylate glycidyl ether (for example, trade name: 4-HBAGE, manufactured by Nippon Kasei Co., Ltd.), and the like. Kasei Co., Ltd.), tetrahydrofurfuryl (meth)acrylate, 2-isocyanatoethyl (meth)acrylate, 2-(meth)acryloyloxyethyl succinate, 2-(meth)acryloyloxyethyl hexahydrophthalate, 3-(meth)acryloxypropyltrimethoxysilane, 3-(meth)acryloxypropylmethyldimethoxysilane, 3-(meth)acryloxypropyltriethoxysilane, 3-(meth)acryloxypropylmethyldiethoxysilane, 2-(meth)acryloyloxyethyl phosphate, bis(2-(meth)acryloyloxyethyl)phosphate, KAYAMER PM-2 (trade name, manufactured by Nippon Kayaku Co., Ltd.), KAYAMER PM-21 (trade name, manufactured by Nippon Kayaku Co., Ltd.), γ-butyl lactone (meth)acrylate, 3-methyl-3-oxetanyl (meth)acrylate, 3-ethyl-3-oxetanyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, dimethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate, and the like.

[0052] The component (D) may be used alone or in combination of two or more.

[0053] The content of component (D) based on 100% by mass of the total of components (A), (D) to (G) may be 1.0 to 35% by mass, 5.0 to 30% by mass, 8.0 to 25% by mass, or 9.0 to 20% by mass. Furthermore, the content of component (D) based on 100% by mass of the total of components (A) to (G) may be 0.5 to 20% by mass, 1.0 to 10% by mass, 1.2 to 5% by mass, or 1.5 to 4% by mass. By having the content of component (D) within the above range, a cured product with excellent adhesion to the insert metal can be obtained.

[0054] <Component (E)> Component (E) is a monofunctional acrylate compound or monofunctional methacrylate compound having, as an ester substituent, a group other than the ester substituents of component (A) and component (D). By including component (E), the viscosity of the thermosetting composition can be adjusted, and the hardness of the obtained cured product can be adjusted and burrs can be suppressed.

[0055] Examples of component (E) include ethyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, t-butyl (meth)acrylate, 2-ethylhexyl methacrylate, isodecyl (meth)acrylate, lauryl (meth)acrylate, stearyl (meth)acrylate, methyl (meth)acrylate, butoxyethylene glycol (meth)acrylate, methoxydiethylene glycol (meth)acrylate, butoxypolyethylene glycol (meth)acrylate, methoxypolyethylene glycol (meth)acrylate, and urethane (meth)acrylate. Among these, n-butyl (meth)acrylate, isobutyl (meth)acrylate, t-butyl (meth)acrylate, 2-ethylhexyl methacrylate, isodecyl (meth)acrylate, lauryl (meth)acrylate, and stearyl (meth)acrylate are preferred from the viewpoint of ease of viscosity adjustment, and 2-ethylhexyl methacrylate, isodecyl (meth)acrylate, lauryl (meth)acrylate, and stearyl (meth)acrylate are more preferred.

[0056] From the viewpoint of suppressing discoloration to yellow or the like during heat curing, it is preferable that component (E) does not contain an aliphatic urethane structure (for example, —NH—C(═O)—O—).

[0057] Examples of component (α) that is contained in component (E) and has a melting point of −5° C. or higher include stearyl methacrylate, stearyl acrylate, and lauryl acrylate.

[0058] The component (E) may be used alone or in combination of two or more.

[0059] The content of component (E) based on 100% by mass of the total of components (A) and (D) to (G) may be 0 to 20% by mass, 0 to 15% by mass, or 1.0 to 10% by mass. Furthermore, the content of component (E) based on 100% by mass of the total of components (A) to (G) may be 0 to 10% by mass, 0 to 5% by mass, 0 to 3% by mass, or 1 to 2% by mass. By ensuring that the content of component (E) is within the above range, a cured product having excellent toughness and adhesion and appropriate flexibility can be obtained.

[0060] <Component (F)> Component (F) is a polyfunctional acrylate or methacrylate compound (preferably containing 2 to 5 functional groups) having an ester substituent other than the ester substituent of component (A). By including component (F), the resulting cured product can have high mechanical strength and excellent heat distortion resistance.

[0061] Examples of component (F) include tricyclodecane dimethanol di(meth)acrylate, 1,6-hexanediol diacrylate, 1,10-decanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, dipropylene glycol di(meth)acrylate, alkoxylated hexanediol di(meth)acrylate, alkoxylated aliphatic di(meth)acrylate, polyethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, and polyester di(meth)acrylate (for example, commercially available products such as CN2203, CN2270, CN2271, CN2272, CN2273, CN2274, and CN2283 (all manufactured by Arkema)). Among these, 1,6-hexanediol diacrylate, 1,10-decanediol di(meth)acrylate, and 1,9-nonanediol di(meth)acrylate are preferred because they are more likely to provide heat distortion resistance, and 1,10-decanediol di(meth)acrylate and 1,9-nonanediol di(meth)acrylate are more preferred.

[0062] From the viewpoint of heat resistance, it is preferable that component (F) does not contain an aliphatic urethane structure (for example, —NH—C(═O)—O—).

[0063] Examples of component (α) that is contained in component (F) and has a melting point of −5° C. or higher include 1,10-decanediol di(meth)acrylate and 1,9-nonanediol di(meth)acrylate.

[0064] The component (F) may be used alone or in combination of two or more.

[0065] The content of component (F) based on 100% by mass of the total of components (A) and (D) to (G) may be 20 to 80% by mass, 30 to 75% by mass, 35 to 70% by mass, or 40 to 68% by mass. Furthermore, the content of component (F) based on 100% by mass of the total of components (A) to (G) may be 1.0 to 30% by mass, 5.0 to 20% by mass, 7.0 to 18% by mass, or 8.0 to 16% by mass. By having the content of component (F) within the above range, a cured product having excellent mechanical strength, excellent heat distortion resistance, and appropriate flexibility can be obtained.

[0066] <Component (G)> Component (G) is a block copolymer containing at least one block composed of repeating units represented by the following formula (G1) and at least one block composed of repeating units represented by the following formula (G2).

[0067]

[0068] (In formula (G1), R ４０１ is a hydrogen atom or a methyl group. ４０２ is a hydrogen atom or a methyl group. ４０３ represents an alkyl group having 2 to 18 carbon atoms, -R ４１１ OR ４１２ , or -R ４１３ SR ４１４ It is. ４１１ and R ４１３ are each independently an alkylene group having 1 to 30 carbon atoms. ４１２ and R ４１４ are each independently an alkyl group having 1 to 30 carbon atoms.

[0069] R ４０３ The number of carbon atoms in the alkyl group of R is preferably 2 to 12, and more preferably 2 to 8. ４１１ and R ４１３ The alkylene group preferably has 2 to 18 carbon atoms. ４１２ and R ４１４ The alkyl group preferably has 2 to 18 carbon atoms.

[0070] Component (G) is a component generally known as an elastomer, and is a polymer with viscoelasticity, small intermolecular interactions, a small Young's modulus, and a large fracture strain, exhibiting highly elastic properties. Component (G) also exhibits properties that make it resistant to cure shrinkage and thermal shrinkage. By incorporating component (G), the occurrence of warpage in a cured product of the thermosetting composition (e.g., an LED reflector) is suppressed when the composition is thermoset in a state where it is integrally molded with another material, such as a metal material. This reduces the rate of defective products in molded products containing the cured product (e.g., an integrally molded product of an LED reflector and a lead frame), enabling high production stability.

[0071] The block polymer containing at least one block consisting of the repeating unit represented by formula (G1) and at least one block consisting of the repeating unit represented by formula (G2) is not limited in the number of blocks, and may be a diblock copolymer, a triblock copolymer, or a tetrablock copolymer. It may also be a radially branched star polymer containing three or more polymer chains consisting of the block copolymer. The block copolymer is preferably a diblock copolymer or a triblock copolymer, and more preferably a triblock copolymer represented by the following general formula (G3):

[0072] (In formula (G3), R ４０１ ~R ４０３ are as defined in the formulas (G1) and (G2). 1, m, and n are the average numbers of constituent units in each block.

[0073] An example of a commercially available block copolymer containing at least one block composed of repeating units represented by formula (G1) and at least one block composed of repeating units represented by formula (G2) is Kuraly, manufactured by Kuraray Co., Ltd.

[0074] From the viewpoint of suppressing warpage of a molded article and improving reflectivity, durability, toughness, and chemical resistance, it is preferable that the proportion of the repeating unit represented by formula (G1) relative to the total of the repeating unit represented by formula (G1) and the structural unit represented by formula (G2) is 10 mol % or more.

[0075] From the viewpoint of obtaining appropriate elasticity, the proportion of the structural unit represented by formula (G2) relative to the total of the structural unit represented by formula (G1) and the structural unit represented by formula (G2) in component (G) is preferably 30 to 95 mol %, more preferably 40 to 90 mol %.

[0076] The number average molecular weight (Mn) of component (G) is preferably 3,000 or more, more preferably 5,000 or more, and even more preferably 8,000 or more, and is preferably 150,000 or less, more preferably 130,000 or less, and even more preferably 110,000 or less.

[0077] The weight average molecular weight (Mw) of component (G) is preferably 5,000 or more, more preferably 8,000 or more, and even more preferably 10,000 or more, and is preferably 200,000 or less, more preferably 170,000 or less, and even more preferably 150,000 or less.

[0078] The molecular weight distribution (Mw / Mn) of component (G) is preferably 6 or less, more preferably 5 or less, and even more preferably 3 or less. The molecular weight distribution (Mw / Mn) is particularly preferably 1.

[0079] The content of component (G) relative to 100% by mass of the total of components (A) and (D) to (G) may be 3 to 50% by mass, 5 to 45% by mass, 7 to 40% by mass, or 10 to 35% by mass. Furthermore, the content of component (G) relative to 100% by mass of the total of components (A) to (G) may be 1.0 to 20% by mass, 2.0 to 15% by mass, 2.5 to 10% by mass, or 3.0 to 7.0% by mass.

[0080] The component (G) may be used alone or in combination of two or more.

[0081] In one embodiment, the thermosetting composition satisfies the following ratio I. Ratio I: The content of a component contained in the components (A) and (D) to (G) and having a melting point (Tm) of -5°C or higher (hereinafter, sometimes referred to as component (α)) is 40% by mass or higher, based on 100% by mass of the total of the components (A) and (D) to (G). Due to the above-mentioned configuration, the thermosetting composition of this embodiment has excellent storage stability.

[0082] By satisfying the above ratio I, the thermosetting composition according to this embodiment does not require the strict temperature control (for example, maintaining a state cooled to an extremely low temperature range, such as -20°C or below) that has been required to store conventional thermosetting compositions in a solidified state, thereby facilitating storage of the thermosetting composition. By maintaining the thermosetting composition in a state cooled to a higher temperature than conventionally, for example, a temperature range of -10°C or thereabouts, the resin component, such as a (meth)acrylate compound, and the inorganic component, such as a white pigment, can be uniformly mixed and maintained in a solidified state. Therefore, a stable storage state can be maintained in which solid-liquid separation, in which the resin component and the inorganic component separate within the composition, is suppressed. For this reason, the thermosetting composition according to this embodiment has excellent storage stability.

[0083] Furthermore, the thermosetting composition of this embodiment does not require the strict temperature control (for example, temperature control to maintain a state cooled to an extremely low temperature range of −20° C. or lower) that has been required to store conventional thermosetting compositions in a solidified state, thereby reducing the costs required to store the thermosetting composition. For example, the introduction of special cooling equipment and strict temperature control that have been required to maintain a state cooled to the aforementioned extremely low temperature range are no longer required, resulting in corresponding cost savings.

[0084] Component (α), which is included in components (A) and (D) to (G) and has a melting point of −5° C. or higher, includes the components described in the respective descriptions of components (A) and (D) to (G) and the components described in the Examples. The melting points of the respective components can be determined by the methods described in the Examples.

[0085] Ratio I may be 45% by mass or more, 47% by mass or more, or 70% by mass or less, 65% by mass or less, or 60% by mass or less, based on 100% by mass of the total of components (A) and (D) to (G). The higher the content of component (α), the more stable a solidified product can be obtained in which components (B) and (C) in the composition are less likely to separate when the thermosetting composition is cooled, and the better the storage stability. If the content of component (α) is low, the composition must be stored in a freezer capable of maintaining extremely low storage temperatures, resulting in poor storage stability.

[0086] In one embodiment, the thermosetting composition satisfies the following ratio II: Ratio II: The total content of the components (B) and (C) is 85% by mass or less, based on 100% by mass of the total of the components (A) to (G).

[0087] In the cured product obtained using the thermosetting composition of this embodiment, the occurrence of cracks, chips, and the like due to slight impact, which occurs in cured products with higher hardness obtained using conventional thermosetting compositions, is suppressed. Therefore, the occurrence rate of defective products can be reduced in molded products (e.g., LED reflectors) made from the cured product obtained using the thermosetting composition of this embodiment, and high production stability can be achieved. Furthermore, since the cured product obtained using the thermosetting composition of this embodiment is less likely to crack or chip due to slight impact, it has excellent handleability and can also improve production stability in the production of optical semiconductors and the like using molded products made from the cured product.

[0088] Furthermore, by satisfying the above-mentioned ratio II, the thermosetting composition of this embodiment can provide high flexibility and excellent heat resistance and light resistance in the resulting cured product. The reason why the cured product obtained from the thermosetting composition of this embodiment has excellent heat resistance and light resistance is presumably because, by making the thermosetting composition have the above-mentioned compositional ratio, an excessive increase in viscosity of the composition can be suppressed, and as a result, the curing reaction of the monomer components contained in the composition can proceed smoothly, and the amount of unreacted monomer remaining in the cured product can be reduced.

[0089] Based on a total of 100% by mass of components (A) to (G), the total content of components (B) and (C) (ratio II) can be, for example, 85% by mass or less, 80% by mass or less, 75% by mass or less, or 70% by mass or less, or 50% by mass or more, 60% by mass or more, or 65% by mass or more. The upper and lower limits can be arbitrarily combined. The lower the total content of components (B) and (C), the more likely it is that the hardness of the cured product will not increase excessively, and excellent flexibility will be obtained. The higher the total content of components (B) and (C), the more likely it is that the hardness and strength of the cured product will be ensured and the occurrence of burrs during molding processing will be suppressed.

[0090] <Component (H)> The thermosetting composition of one embodiment may further contain a plate-like filler (referred to as component (H) in the following description). By including component (H), the viscosity of the thermosetting composition can be adjusted, making it possible to adjust the hardness of the resulting cured product and suppress burrs. Furthermore, by including component (H), warpage of the resulting cured product can be suppressed. Note that while component (G) has the effect of suppressing cure shrinkage by overfilling during molding, component (H) has the effect of suppressing shrinkage in the MD and TD directions. The mechanisms for suppressing warpage are different. Furthermore, by including component (H), the rate of solid-liquid separation during storage at room temperature can be reduced.

[0091] Examples of component (H) include talc, calcined talc, kaolin, calcined kaolin, mica, clay, sericite, glass flakes, synthetic hydrotalcite, various metal foils, graphite, molybdenum disulfide, tungsten disulfide, boron nitride, plate-like iron oxide, plate-like calcium carbonate, and plate-like aluminum hydroxide. Among these, talc, calcined talc, kaolin, calcined kaolin, mica, clay, and graphite are preferred, and when these are used, a light-blocking effect can also be obtained. Talc is more preferred because it is less likely to cause a decrease in reflectance due to incorporation.

[0092] The average particle size (D50) of component (H) is preferably 0.5 to 30 μm, more preferably 0.8 to 15 μm, and particularly preferably 0.8 to 8 μm. Within the above range, molding defects and defective products can be suppressed. The average particle size (D50) of component (H) is measured using a laser diffraction particle size distribution analyzer.

[0093] The component (H) may be used alone or in combination of two or more.

[0094] <Other Optional Components> The thermosetting composition of one embodiment may further contain the following components from the viewpoints of adjusting viscosity, storage stability at room temperature, suppression of burrs, and the like.

[0095] (Filler) Examples of the filler include silver, gold, silicon, silicon carbide, copper oxide, iron oxide, cobalt oxide, titanium carbide, cerium oxide, ITO (indium tin oxide), ATO (antimony trioxide), hydroxyapatite, graphene, graphene oxide, single-walled carbon nanotubes, multi-walled carbon nanotubes, fullerene, diamond, mesoporous carbon, etc. Silicon carbide and titanium carbide are preferred, and titanium oxide and titanium carbide are more preferred in terms of being able to maintain whiteness.

[0096] The average primary particle size of the filler is preferably 0.005 to 0.1 μm, which is measured using a transmission electron microscope.

[0097] The filler may be used alone or in combination of two or more.

[0098] When a filler is contained, the content of the filler is not particularly limited, but from the viewpoint of storage stability at room temperature and the appearance of the cured product, it is, for example, 0.05 to 10 parts by mass, preferably 0.07 to 5 parts by mass, and more preferably 0.08 to 3 parts by mass, based on 100 parts by mass of the total of components (A) to (G).

[0099] In one embodiment, the thermosetting composition preferably contains the above-mentioned filler, which can reduce the rate of solid-liquid separation during storage at room temperature.

[0100] (Additives) The thermosetting composition of one embodiment may further contain additives to the extent that the effects of the present invention are not impaired. Examples of additives include polymerization initiators, antioxidants, light stabilizers, UV absorbers, plasticizers, inorganic fillers, colorants, antistatic agents, lubricants, release agents, flame retardants, leveling agents, and antifoaming agents. These additives may be known additives. In addition to these, from the viewpoint of improving the dispersibility of components (B), (C), and (H) in the mixture of components (A), (D), (E), and (F), which are liquid components, the thermosetting composition may contain a silica coupling agent, which was exemplified as a surface treatment agent for component (B) above.

[0101] A polymerization initiator may be contained to promote the polymerization reaction. The polymerization initiator is not particularly limited, but examples thereof include radical polymerization initiators. The radical polymerization initiator is not particularly limited, but examples thereof include ketone peroxides, hydroperoxides, diacyl peroxides, dialkyl peroxides, peroxyketals, alkyl peresters (peroxyesters), and peroxycarbonates.

[0102] Specific examples of ketone peroxides include methyl ethyl ketone peroxide, methyl isobutyl ketone peroxide, acetylacetone peroxide, cyclohexanone peroxide, and methylcyclohexanone peroxide.

[0103] Specific examples of hydroperoxides include 1,1,3,3-tetramethylbutyl hydroperoxide, cumene hydroperoxide, t-butyl hydroperoxide, p-menthane hydroperoxide, and diisopropylbenzene hydroperoxide.

[0104] Specific examples of diacyl peroxides include diisobutyryl peroxide, bis-3,5,5-trimethylhexanol peroxide, dilauroyl peroxide, dibenzoyl peroxide, m-toluylbenzoyl peroxide, and succinic acid peroxide.

[0105] Specific examples of dialkyl peroxides include dicumyl peroxide, 2,5-dimethyl-2,5-di(t-butylperoxy)hexane, 1,3-bis(t-butylperoxyisopropyl)hexane, t-butylcumyl peroxide, di-t-butyl peroxide, di-t-hexyl peroxide, and 2,5-dimethyl-2,5-di(t-butylperoxy)hexyne-3.

[0106] Specific examples of peroxyketals include 1,1-di-t-hexylperoxy-3,3,5-trimethylcyclohexane, 1,1-di-t-hexylperoxycyclohexane, 1,1-di-t-butylperoxy-2-methylcyclohexane, 1,1-di-t-butylperoxycyclohexane, 1,1-di(t-amylperoxy)cyclohexane, 2,2-di(t-butylperoxy)butane, and 4,4-bis-t-butylperoxybutylpentanoate.

[0107] Specific examples of alkyl peresters (peroxy esters) include 1,1,3,3-tetramethylbutyl peroxyneodecanoate, α-cumyl peroxyneodecanoate, t-butyl peroxyneodecanoate, t-hexyl peroxyneodecanoate, t-butyl peroxyneoheptanoate, t-hexyl peroxypivalate, t-butyl peroxypivalate, 1,1,3,3-tetramethylbutyl peroxy-2-ethylhexanoate, t-amyl peroxy-2-ethylhexanoate, t-butyl peroxy-2-ethylhexanoate, t-butyl peroxyisobutyrate, di-t-butylperoxyhexahydroterephthalate, 1,1,3,3-tetramethylbutyl peroxy peroxyhexane, t-hexylper ...

[0108] Specific examples of peroxycarbonates include di-n-propyl peroxydicarbonate, diisopropyl peroxycarbonate, di-4-t-butylcyclohexyl peroxycarbonate, di-2-ethylhexyl peroxycarbonate, di-sec-butyl peroxycarbonate, di-3-methoxybutyl peroxydicarbonate, di-2-ethylhexyl peroxydicarbonate, diisopropyl peroxydicarbonate, t-amyl peroxyisopropyl carbonate, t-butyl peroxyisopropyl carbonate, t-butyl peroxy-2-ethylhexyl carbonate, and 1,6-bis(t-butylperoxycarboxyloxy)hexane.

[0109] Commercially available polymerization initiators include, for example, Pertible E (manufactured by NOF Corporation) and Perhexa HC (manufactured by NOF Corporation) (both are trade names).

[0110] The polymerization initiator may be used alone or in combination of two or more. When a polymerization initiator is contained, the content of the radical polymerization initiator is preferably 0.001 to 20 parts by mass based on 100 parts by mass of the total of components (A) to (G).

[0111] Examples of the antioxidant include phenol-based antioxidants, phosphorus-based antioxidants, sulfur-based antioxidants, vitamin-based antioxidants, lactone-based antioxidants, and amine-based antioxidants.

[0112] Examples of phenolic antioxidants include tetrakis[methylene-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate]methane, β-(3,5-di-t-butyl-4-hydroxyphenyl)propionic acid stearyl ester, 1,3,5-trimethyl-2,4,6-tris(3,5-di-t-butyl-4-hydroxybenzyl)benzene, tris(3,5-di-t-butyl-4-hydroxybenzyl)isocyanurate, tris[(3,5-di-t- butyl-4-hydroxyphenyl)propionyloxyethyl]isocyanurate, 2,6-di-t-butyl-4-methylphenol, 3,9-bis[1,1-dimethyl-2-{β-(3-t-butyl-4-hydroxy-5-methylphenyl)propionyloxy}ethyl]-2,4,8,10-tetraoxaspiro[5,5]undecane, tris(2,6-dimethyl-3-hydroxy-4-t-butylbenzyl)isocyanurate, for example, IRGANOX Commercially available products such as IRGANOX 1010, IRGANOX 1076, IRGANOX 1330, IRGANOX 3114, IRGANOX 3125, and IRGANOX 3790 (all manufactured by BASF), CYANOX 1790 (manufactured by Cyanamid), SUMILIZER BHT, and SUMILIZER GA-80 (all manufactured by Sumitomo Chemical Co., Ltd.) can be used (all are trade names).

[0113] Examples of phosphorus-based antioxidants include tris(2,4-di-t-butylphenyl)phosphite, 2-[[2,4,8,10-tetrakis(1,1-dimethylethyl)dibenzo[d,f][1,3,2]dioxaphosphepin-6-yl]oxy]-N,N-bis[2-[[2,4,8,10-tetrakis(1,1-dimethylethyl)dibenzo[d,f][1,3,2]dioxaphosphepin-6-yl]oxy]-ethyl]ethanamine, cyclic neopentanetetraylbis(2,6-di-t-butyl-4-methylphenyl)phosphite, and distearyl pentaerythritol diphosphite. Examples of such antioxidants include IRGAFOS 168, IRGAFOS 12, and IRGAFOS 38 (all manufactured by BASF), ADK STAB 329K, and ADK Commercially available products such as STAB PEP36 and ADK STAB PEP-8 (manufactured by ADEKA Corporation), Sandstab P-EPQ (manufactured by Clariant), Weston 618, Weston 619G, and Weston 624 (manufactured by GE) can be used (all are trade names).

[0114] Examples of sulfur-based antioxidants include dilauryl thiodipropionate, distearyl thiodipropionate, dimyristyl thiodipropionate, laurylstearyl thiodipropionate, pentaerythritol tetrakis(3-dodecylthiopropionate), pentaerythritol tetrakis(3-laurylthiopropionate), and the like. For example, commercially available products such as DSTP "Yoshitomi", DLTP "Yoshitomi", DLTOIB, and DMTP "Yoshitomi" (all manufactured by API Corporation), Seenox 412S (manufactured by Shipro Kasei Co., Ltd.), Cyanox 1212 (manufactured by Cyanamid Co., Ltd.), and SUMILIZER TP-D (manufactured by Sumitomo Chemical Co., Ltd.) can be used (all are trade names).

[0115] Examples of vitamin-based antioxidants include tocopherol and 2,5,7,8-tetramethyl-2(4',8',12'-trimethyltridecyl)coumaron-6-ol, and commercially available products such as IRGANOX E201 (manufactured by BASF) can be used. Examples of lactone-based antioxidants that can be used include those described in JP-A-7-233160 and JP-A-7-247278. HP-136 (trade name, manufactured by BASF, compound name: 5,7-di-t-butyl-3-(3,4-dimethylphenyl)-3H-benzofuran-2-one) can also be used.

[0116] Examples of the amine-based antioxidant include commercially available products such as IRGASTAB FS 042 (manufactured by BASF) and GENOX EP (manufactured by Crompton, chemical name: dialkyl-N-methylamine oxide) (all trade names).

[0117] The antioxidant may be used alone or in combination of two or more. When an antioxidant is contained, the content of the antioxidant is preferably 0.001 to 20 parts by mass based on 100 parts by mass of the total of components (A) to (G), from the viewpoint of not impairing the effects of the present invention.

[0118] Any light stabilizer can be used, such as an ultraviolet absorber or a hindered amine light stabilizer, but a hindered amine light stabilizer is preferred. Specific examples of hindered amine light stabilizers include ADK STAB LA-52, LA-57, LA-62, LA-63, LA-67, LA-68, LA-77, LA-82, LA-87, and LA-94 (manufactured by ADEKA Corporation), Tinuvin 123, 144, 440, 662, 765, and 770DF, Tinuvin XT 850 FF, Tinuvin XT 855 FF, and Chimassorb 2020, 119, and 944 (manufactured by BASF), Hostavin N30 (manufactured by Hoechst), Cyasorb UV-3346 and UV-3526 (manufactured by Cytec), and Uval 299 (manufactured by GLC) and Sanduvor PR-31 (manufactured by Clariant) (all trade names).

[0119] Specific examples of the ultraviolet absorber include ADK STAB LA-31, ADK STAB LA-32, ADK STAB LA-36, ADK STAB LA-29, ADK STAB LA-46, ADK STAB LA-F70, and ADK STAB 1413 (all manufactured by ADEKA Corporation), Tinuvin P, Tinuvin 234, Tinuvin 326, Tinuvin 328, Tinuvin 329, Tinuvin 213, Tinuvin 571, Tinuvin 765, Tinuvin 1577ED, Chimassorb 81, and Tinuvin 120 (all manufactured by BASF). Among these, the Tinuvin series manufactured by BASF is preferred, and Tinuvin 765 is more preferred.

[0120] The light stabilizer may be used alone or in combination of two or more. When a light stabilizer is contained, the content of the light stabilizer is preferably 0.001 to 20 parts by mass based on 100 parts by mass of the total of components (A) to (G), from the viewpoint of not impairing the effects of the present invention.

[0121] Examples of the release agent include internal release agents. The internal release agent dissolves and disperses well in the (meth)acrylate compound, and when cured, it is in a low-viscosity molten state, which facilitates molecular motion. When cured, it is separated from the curing resin component and exists between the mold and the cured component, thereby providing releasability. Furthermore, when released from the mold, it is preferably low-viscosity in the molten state, which further enhances releasability. Although there is no particular specification for the internal release agent, an aliphatic compound is desirable.

[0122] The aliphatic compound used as an internal mold release agent preferably has a melting point in the range of -40°C to 180°C, more preferably in the range of -30°C to 180°C. By setting the melting point of the aliphatic compound to -40°C or higher, the compound will not vaporize during curing, causing bubbles in the product and resulting in poor appearance, and will exhibit good mold releasability. Furthermore, by setting the melting point of the aliphatic compound to 180°C or lower, the compound will have improved solubility, resulting in good appearance and mold releasability.

[0123] The aliphatic compound is preferably a compound represented by the following formula (V): (In formula (V), R ４ represents an aliphatic hydrocarbon group having 6 to 30 carbon atoms. W represents a hydrogen atom, a metal atom, or a hydrocarbon group having 1 to 8 carbon atoms. When W is a metal atom, O and W are ionic bonded.

[0124] R in formula (V) ４ The aliphatic hydrocarbon group may have a linear or branched structure, and the bonding state within the molecular chain may be single bonds only or may contain multiple bonds. Specific examples include saturated aliphatic hydrocarbon groups and unsaturated aliphatic hydrocarbon groups. The number of multiple bonds in the unsaturated aliphatic hydrocarbon group may be one or more.

[0125] R in formula (V) ４ The carbon number of the hydrocarbon group in formula (V) is 6 to 30. If the carbon number is less than 6, it may volatilize during curing, preventing the aliphatic compound from existing between the mold and the material, resulting in failure to exhibit mold releasability or the possibility of air bubbles remaining in the material. If the carbon number is more than 30, the mobility of the material decreases, and the aliphatic compound is incorporated into the material, making the material opaque or failing to exhibit mold releasability. R in formula (V) ４ The hydrocarbon group preferably has 6 to 26 carbon atoms, more preferably 8 to 22 carbon atoms.

[0126] Examples of the metal atom in W in formula (V) include alkali metals such as lithium and sodium, alkaline earth metals such as magnesium and calcium, zinc, and aluminum. When W is an alkaline earth metal or aluminum, it is divalent or more, so the formula (V) of the aliphatic compound is (R ４ —CO—O) ｑ -W, where q is 2 to 4.

[0127] The aliphatic hydrocarbon group for W in formula (V) may have a linear or branched structure, and the bonding state within the molecular chain may be single bonds only or may contain multiple bonds. Specific examples include saturated aliphatic hydrocarbon groups and unsaturated aliphatic hydrocarbon groups. The number of multiple bonds in the unsaturated aliphatic hydrocarbon group may be one or more. The aliphatic hydrocarbon group for W has 1 to 8 carbon atoms. If the carbon number is 8 or more, this may increase the melting point of the aliphatic compound or reduce its solubility, causing the aliphatic compound to be incorporated into the resin component or to be unevenly distributed during curing, resulting in a lack of mold releasability or opacity. The aliphatic hydrocarbon group for W preferably has 1 to 6 carbon atoms.

[0128] In order to exhibit good releasability, when W in the aliphatic compound represented by formula (V) is a hydrogen atom, R ４ is preferably an aliphatic hydrocarbon group having 6 to 20 carbon atoms. When W is a metal atom, R ４ is preferably an aliphatic hydrocarbon group having 6 to 18 carbon atoms. When W is an aliphatic hydrocarbon group, R ４ The total number of carbon atoms in the aliphatic hydrocarbon groups of W is preferably 7 to 30.

[0129] Examples of the release agent include magnesium stearate and zinc stearate.

[0130] When a release agent is contained, the content of the release agent is 0.001 to 20 parts by mass based on 100 parts by mass of the total of components (A) to (G). By being in this range, the transferability of the mold shape and shape stability against heat can be maintained, and good releasability can be exhibited.

[0131] In one embodiment, the thermosetting composition essentially consists of components (A) to (G), and optionally component (H), a filler, and additives, and may contain other inevitable impurities as long as the effects of the present invention are not impaired. For example, 85% by weight or more, 95% by weight or more, 99% by weight or more, or 100% by mass of the thermosetting composition may consist of components (A) to (G), or components (A) to (G), and optionally component (H), a filler, and additives.

[0132] The thermosetting composition of this embodiment can be prepared by mixing the above components in a predetermined ratio. The mixing method is not particularly limited, and any known means such as a stirrer (mixer) can be used. The components can be mixed at room temperature, under cooling, or under heating, and under normal pressure, reduced pressure, or increased pressure.

[0133] The thermosetting composition according to one embodiment has a viscosity of 10 s at 25°C. －１ The viscosity at a shear rate of 10 s is 1 to 200 Pa·s, and more preferably 5 Pa·s or more and less than 60 Pa·s. When the viscosity of the thermosetting composition is in the above range, excellent flowability and high filling ability can be obtained, and the resulting cured product can have excellent flexibility. －１ The viscosity at a shear rate of 1000 rpm can be determined by the method described in the Examples.

[0134] The thermosetting composition according to one embodiment has a 10 s 25° C. curing temperature of a mixture of components (A) and (D) to (G) among the components contained in the thermosetting composition. －１ The viscosity at a shear rate of 10 s at 25°C is 1 to 500 mPa·s, and more preferably 1 mPa·s or more and less than 100 mPa·s. When the viscosity of the mixture of components (A) and (D) to (G) is within the above range, the thermosetting composition has excellent flowability, high filling properties, and the resulting cured product has excellent flexibility. －１ The viscosity at a shear rate of 1000 rpm can be determined by the method described in the Examples.

[0135] The thermosetting composition of this embodiment suppresses warpage in a cured product (e.g., an LED reflector) of the thermosetting composition after it is heat-cured in a state where it is integrally molded with another material such as a metal material, thereby reducing the rate of defective molded products (e.g., an integrally molded product of an LED reflector and a lead frame) containing the cured product, and achieving high production stability.

[0136] Furthermore, according to the thermosetting composition of this embodiment, since the solidified state can be maintained at a cooling temperature achievable with general cooling equipment, solid-liquid separation in the thermosetting composition is suppressed, making it easy to maintain a stable storage state and providing excellent storage stability. Furthermore, the thermosetting composition of this embodiment is a suitable material, for example, as a reflector for optical semiconductors. The resulting cured product has excellent flexibility and is less likely to crack or chip due to slight impact, thereby reducing the rate of defective molded products (e.g., reflectors) and achieving high production stability. Furthermore, the resulting cured product of the thermosetting composition of this embodiment combines excellent flexibility with heat resistance and light resistance, and is less likely to suffer from defects such as yellowing after long-term exposure to light or heat, for example, when used for a long period of time as a reflector for optical semiconductors. Furthermore, the resulting cured product of the thermosetting composition of this embodiment has excellent flexibility and is less likely to warp, resulting in a cured product that combines flexibility and excellent appearance. Furthermore, according to one embodiment of the thermosetting composition using a white pigment as component (C), a cured product can be obtained that has high reflectance in the visible light region, excellent whiteness, excellent heat resistance and light resistance, and excellent adhesion to surrounding components (e.g., lead frames).

[0137] 2. Method for Producing Molded Article A method for producing a molded article according to one aspect of the present invention includes the steps of: supplying the above-described thermosetting composition into a plunger (supplying step); filling a molded article portion (cavity) of a mold with the supplied thermosetting composition by the plunger (filling step); thermosetting the filled thermosetting composition in the molded article portion (curing step); and extruding the thermoset resin (mold releasing step).

[0138] In one embodiment, from the viewpoint of preventing only the resin component from being filled, transfer molding such as LTM (Liquid Transfer Molding), compression molding, or injection molding such as LIM (Liquid Injection Molding) is preferred. Prepolymerization may be performed.

[0139] By using the above-described thermosetting composition, when filling a mold by applying pressure, or when applying excessive dwell pressure after filling, the thermosetting composition can fill even a gap of 1 μm.

[0140] In transfer molding, a transfer molding machine (e.g., a G-Line liquid transfer molding machine) can be used, for example, with a clamping force of 5 to 20 kN, a molding temperature of 100 to 190°C, and a molding time of 30 to 500 seconds, preferably a molding temperature of 100 to 180°C, and a molding time of 30 to 180 seconds. Post-curing may be performed, for example, at 150 to 185°C for 0.5 to 24 hours.

[0141] In compression molding, a compression molding machine can be used, for example, at a molding temperature of 100 to 190° C. for a molding time of 30 to 600 seconds, preferably at a molding temperature of 110 to 170° C. for a molding time of 30 to 300 seconds. Post-curing may be performed, for example, at 150 to 185° C. for 0.5 to 24 hours.

[0142] In liquid injection molding, for example, a liquid thermosetting resin injection molding machine LA-40S is used, and molding can be performed, for example, at a mold clamping force of 10 kN to 40 kN, a molding temperature of 100 to 190°C, and a molding time of 30 to 500 seconds, preferably at a molding temperature of 100 to 180°C, and a molding time of 20 to 180 seconds.

[0143] The molding machine preferably includes a plunger and a mold having a molded product portion, and further includes a shut-off nozzle.

[0144] Fig. 1 is a diagram showing an embodiment of a filling device of a molding machine capable of carrying out an injection molding method according to one embodiment of the present invention. The molding machine of Fig. 1 is an injection molding machine having a plunger mechanism for extruding the thermosetting composition of this embodiment into a mold, and includes a filling device 10 having a plunger 11 shown in Fig. 1 and a mold 20 having a cavity 21 shown in Fig. 2(A). Although not shown, the molding machine also includes a pressure reducing device as a degassing means connected to a fine hole for degassing the cavity 21 (sometimes referred to as the molded product portion 232) in the mold 20, a heating device as a heating means connected to the mold 20, and a cooling device. The molding material is the thermosetting composition of this embodiment.

[0145] A known filling device having a plunger can be used as the filling device 10. Typically, as shown in Fig. 1, the filling device 10 having a plunger 11 is provided with a feed section and a check valve function, and the material introduced from an introduction port (not shown) is fed, stirred, and mixed by moving the check valve 12 (which may be in the form of a screw) back and forth. However, in this embodiment, stirring and mixing are not necessary because the thermosetting composition introduced is a homogeneous liquid.

[0146] In the step of filling the cavity with a plunger, the thermosetting composition is preferably filled into the cavity in the mold through a flow path whose temperature is controlled to 50° C. or less. When the molding method of one embodiment of the present invention is carried out using the apparatus shown in FIG. 2 , the flow path corresponds to the flow path (not shown) of the thermosetting composition in the filling apparatus 10 and the introduction path in the mold 20.

[0147] In a method according to one embodiment of the present invention, a gate system is preferably provided in the flow path between the plunger and the cavity during the process of filling a cavity in a mold with a thermosetting composition filled in the plunger by the plunger, blocking the flow of the curing liquid and the transfer of heat. A molding method according to one embodiment of the present invention will be described below with reference to FIG. 2. When the method according to one embodiment of the present invention is performed using the apparatus shown in FIG. 2, the needle 223 and the opening 222 correspond to the gate system. As described above, the needle 223 moves toward the movable mold 23 and closes the opening 222, thereby cutting off the introduction path 221 just before the heating section 22A. The thermosetting composition introduced into the introduction path 221 remains in the cooling section 22B, blocking the flow of the thermosetting composition and the transfer of heat. Examples of systems that can block the flow of the thermosetting composition and the transfer of heat include a valve gate system and a shut-off nozzle system. The heating device heats the heating section 22A and the movable mold 23. By heating in this manner, the temperature inside the cavity (also referred to as "cavity temperature") can be set to a predetermined temperature. In a method according to one embodiment of the present invention, the temperature of the mold 23 constituting the cavity is preferably set to 100°C or higher and 180°C or lower. The cooling device is a device that cools the flow path of the thermosetting composition. Specifically, it is preferable to cool the filling device 10 and the cooling section 22B of the mold 20 to 10°C or higher and 50°C or lower. In the case of injection molding, the needle (not shown) in FIG. 1 corresponds to the needle 223 in FIG. 2, and the flow path (not shown) in FIG. 1 corresponds to the introduction path 221 in FIG. 2.

[0148] The supply process is shown in Figure 1. In the case of transfer molding or compression molding, the material can be measured by inserting an appropriate amount of material into plunger 11 using a supply device (not shown), such as a syringe. In the case of injection molding, the thermosetting composition is injected into filling device 10 shown in Figure 1 through an inlet (not shown). The injected thermosetting composition is pushed out into check valve 12, and then a predetermined amount is measured by plunger 11. After measurement is completed or before injection, check valve 12 moves forward, functioning as a check valve when plunger 11 moves. During this time, the flow path is cooled by a cooling device, so the thermosetting composition flows smoothly without hardening.

[0149] The filling process is shown, for example, in FIG. 2(B). When injecting the thermosetting composition into the cavity, it is preferable to depressurize the cavity by using a vent to release air from the cavity or by using a small hole connected to a decompression device such as the vacuum pipe 240 in FIG. 2 that allows the cavity to be depressurized. The reason for this is that during the process of injecting the thermosetting composition into the cavity and completely filling it, the vent is used to release air from the cavity, while the decompression of the cavity ensures complete filling by eliminating air. If this mechanism is not available, it is preferable to use a mechanism (e.g., a vent mechanism) that releases air from the cavity during material filling. To mold the thermosetting composition, first, the movable mold 23 is brought close to the fixed mold 22 and clamped ( FIG. 2(A) ). The movement of the movable mold 23 is temporarily stopped when the elastic member 238 of the movable mold 23 abuts against the elastic member 224 of the fixed mold 22.

[0150] The thermosetting composition is preferably filled into the cavity by opening the gate of the gate system (moving the needle 223 toward the fixed mold 22) and filling the cavity 21 in the mold with the thermosetting composition. The heating units 22A provided on the movable mold 23 and the fixed mold 22 are constantly heated, and the cavity temperature is set to, for example, 60°C or higher, preferably 100°C to 180°C, and particularly preferably 110°C to 170°C. When using an injection molding machine, when starting injection from the injection unit into the cavity, the nozzle of the shut-off nozzle (or valve gate in some cases) is opened, the plunger of the injection unit is moved, and the thermosetting component is injected into the cavity. When using a transfer molding machine, since the entire material is cured from the plunger to the cavity, it is sufficient for the material to flow into the cavity, and heat exchange does not need to be blocked.

[0151] The curing process is shown, for example, in FIG. 2(C). Once the filling of the cavity 21 with the thermosetting composition is complete, the thermosetting composition begins curing. However, to improve the transferability of the molded product, it is preferable to apply a predetermined pressure to the thermosetting composition during curing. That is, it is preferable to pressurize the plunger 11 to a pressure of 1.0 MPa or more and 30 MPa or less. This pressure applied to the thermosetting composition to improve transferability is called dwell pressure. The curing process preferably involves dwelling (increasing the pressure applied to the thermosetting composition) after the start of thermal curing and before the completion of curing. After dwelling pressure, the gate of the gate system is closed to perform thermal curing. Specifically, the gate is closed by advancing the needle 223 to close the opening 222. During the molding process, a cooling device is operated to cool the entire flow path of the thermosetting composition, i.e., the filling device 10 of the molding machine and the cooling section 22B provided in the fixed mold 22 of the mold 20. During this process, it is preferable to maintain the entire flow path at a temperature of 10°C or more and 50°C or less, and particularly preferably at 30°C or less.

[0152] The following describes the holding pressure applied by the plunger 11 and the timing of the start of holding pressure. FIG. 3 is a diagram showing the relationship between viscosity and time for the thermosetting composition of this embodiment. In FIG. 3, the period P1 from when the material is injected into the cavity until filling is complete corresponds to the induction period from when heat is applied to the material until curing begins. The curing process is divided into two stages: an early curing stage P2, which occurs after the material begins to harden upon application of heat until it is completely hardened, and a late curing stage P3, at which curing is completed. The viscosity of the thermosetting composition remains low and unchanged during the induction period P1, shows a significant change from low to high viscosity during the early curing stage P2, and gradually increases at a high viscosity during the late curing stage P3.

[0153] In the early stage of curing P2, the thermosetting composition not only changes in viscosity as it transforms from a liquid to a solid, but also in volume, causing it to shrink. Therefore, in actual molding, if pressure is not applied to the thermosetting composition, the molded product will have poor transferability. To improve transferability, it is preferable to apply pressure to the thermosetting composition (holding pressure) to adhere the thermosetting composition to the mold 20 and fill the thermosetting composition through the gate portion. However, with the thermosetting composition of this embodiment, applying pressure while the composition is in a low viscosity state can cause defects such as material leakage from the gap between the fixed mold 22 and the movable mold 23 and hardening (burrs), or malfunction of the ejector pin due to the thermosetting composition penetrating into gaps around the ejector pin. On the other hand, applying pressure when the viscosity is high in the early stage of curing P2 or in the late stage of curing P3 cannot improve transferability because the thermosetting composition is too viscous to undergo compressive deformation, and therefore cannot improve transferability. Therefore, in order to obtain a molded product with high transferability, it is preferable to synchronize the timing of the start of dwelling (dwelling start time T) with the timing of the transition from the induction period P1 to the initial stage P2 of curing in the curing process.

[0154] Here, if the viscosity of the thermosetting composition in the cavity 21 can be detected, the dwell start time T can be determined. Since the thermosetting composition according to this embodiment begins to shrink at the same time as it thickens in the initial stage P2 of curing, it is preferable to detect the time when the shrinkage starts. This allows the dwell start time T to be appropriately determined.

[0155] In the curing step, by holding the pressure under the above-mentioned conditions, sink marks and distortion of the molded product can be prevented and transferability can be improved. After the pressure has been held for a certain period of time, as shown in Figure 2 (C), the needle 223 is advanced to close the opening 222, and the thermosetting composition is heated for a certain period of time to completely cure so that no uncured portions are left. Then, the plunger 11 is advanced to fill the cavity 21 of the mold 20 with the thermosetting composition, and the time required for filling is defined as t １When the filling is completed, the plunger 11 stops. When the curing of the thermosetting composition starts, the thermosetting composition simultaneously contracts, so the plunger 11, which had stopped after the filling step was completed, starts moving forward again. The time required from the completion of the filling step until the plunger 11 starts moving forward again due to contraction is defined as t ２ The time required for further heating to completely cure the thermosetting composition is defined as t ３ In this case, t １ +t ２ +t ３ The total time required for the filling step and the heat curing step is preferably 0.2 to 3 minutes, and more preferably 0.2 to 2 minutes. If it is less than 0.2 minutes, there is a risk of the resin remaining uncured, and if it is more than 3 minutes, this is not preferable from the viewpoint of mass productivity.

[0156] The demolding step is shown in Fig. 2(D), for example. The cured product in the cavity can be removed by separating the movable mold 23 from the fixed mold 22. If demolding is difficult, an ejector mechanism may be provided in the mold as appropriate.

[0157] 3. Cured Product A cured product according to one aspect of the present invention can be produced using the above-described thermosetting composition. The cured product according to one embodiment is preferably a molded product.

[0158] The cured product of one embodiment can be suitably used, for example, as a reflective material for optical semiconductor light-emitting devices, etc. The reflective material using the cured product of one embodiment does not decrease in reflectance even after long-term use, has high reflectance in the visible light region, excellent heat resistance and weather resistance, and excellent adhesion to surrounding components.

[0159] The above-mentioned reflective material has a high reflectance in the visible light region and shows little decrease in reflectance even after long-term use. The initial light reflectance of the reflective material at a wavelength of 450 nm is preferably 85% or more, more preferably 90% or more, even more preferably 93% or more, and particularly preferably 93.5% or more. After a 1,000-hour degradation test at 150°C, the decrease in light reflectance from the initial reflectance is preferably 20% or less, more preferably 15% or less, and even more preferably 10% or less. Furthermore, after a 72-hour degradation test at 180°C, the decrease in light reflectance from the initial reflectance is preferably 9% or less, more preferably 4% or less. The light reflectance is determined by the method described in the examples.

[0160] The cured product according to one embodiment has excellent whiteness and low light transmittance. The light transmittance of the cured product is preferably 2% or less, more preferably 1% or less, and even more preferably less than 0.5%. The light transmittance is determined by the method described in the examples.

[0161] The cured product according to this embodiment has excellent flexibility, a high flexural modulus, and excellent strain resistance. The flexural modulus of the cured product is preferably 1,000 to 15,000 MPa, more preferably 2,000 to 13,000 MPa, and even more preferably 4,000 to 13,000 MPa. The cured product according to this embodiment also has excellent flexibility and a large strain at break measured in accordance with JIS K7171:2016. The strain at break of the cured product is preferably 0.5% or more, more preferably 0.7% or more, and even more preferably 0.8% or more. The flexural modulus and strain at break are determined by the methods described in the Examples.

[0162] The cured product according to this embodiment has excellent flexibility and suppressed warping. The cured product according to this embodiment has a shrinkage in the machine direction, measured in accordance with JIS K6911-1995, of preferably 3% or less, more preferably 2.5% or less, more preferably 2.2% or less, and even more preferably 2% or less.

[0163] The above-mentioned optical semiconductor light emitting device includes the above-mentioned reflector. Other configurations of the optical semiconductor light emitting device may be known. The optical semiconductor element mounting substrate and the optical semiconductor light emitting device will be further described with reference to the drawings. Figure 4 is a schematic cross-sectional view showing one embodiment of the optical semiconductor element mounting substrate and the optical semiconductor device. Figure 4(a) shows a lead frame 510.

[0164] Fig. 4(b) shows an optical semiconductor element mounting substrate 520 in which a cured material is molded as a reflector 521 on the lead frame 510 of Fig. 4(a). The optical semiconductor element mounting substrate 520 has a recess formed by a bottom surface formed by the lead frame 510 and the reflector 521 and an inner peripheral side surface formed by the reflector 521. The cured material constituting the reflector 521 is obtained by curing the thermosetting composition of this embodiment.

[0165] 4(c) shows an optical semiconductor light emitting device 530 in which an optical semiconductor element 531 is mounted on the lead frame of the optical semiconductor element mounting substrate of FIG. 4(b), the optical semiconductor element 531 is bonded to the other lead frame on which the optical semiconductor element 531 is not mounted with wire 532, and the recess is sealed with transparent resin (sealing resin) 533. The sealing resin may contain a phosphor 534 for converting emitted light such as blue light into white light.

[0166] 5A and 5B are schematic cross-sectional views showing another embodiment of an optical semiconductor element mounting substrate and an optical semiconductor light emitting device. Fig. 5A shows a lead frame 610. Fig. 5B shows an optical semiconductor element mounting substrate 620 in which a cured material is molded as a reflector 621 between the lead frames 610 of Fig. 5A. The optical semiconductor element mounting substrate 620 includes the lead frames 610 and the reflector 621 described above between the lead frames 610.

[0167] Fig. 5(c) shows an optical semiconductor light-emitting device 630 equipped with the optical semiconductor element mounting substrate of Fig. 5(b). After an optical semiconductor element 631 is mounted on a lead frame 610 and electrically connected by bonding wires 632, an encapsulating resin portion made of transparent encapsulating resin 633 is cured and molded in one go by a method such as transfer molding or compression molding to encapsulate the optical semiconductor element 631, and then the device is diced into individual pieces. The encapsulating resin may contain a phosphor 634 for converting emitted light such as blue light into white light.

[0168] The dimensions and shapes of each part of the optical semiconductor element mounting board are not particularly limited and can be set appropriately. The sealing resin (sealing material) is made of, for example, epoxy resin, silicone resin, acrylate resin, or the like.

[0169] The present invention will be explained in more detail below by way of examples, but the present invention is not limited to these examples.

[0170] Examples 1 to 27 and Comparative Examples 1 to 8 (Preparation of Thermosetting Composition) Details of each component will be described later.

[0171] Specifically, the thermosetting compositions were prepared by first weighing component (A) and components (D) to (G) in the proportions shown in Tables 1 to 7, mixing them, and stirring. Additionally, 1.0 part by weight of Perhexa HC (manufactured by NOF Corporation) was added as a polymerization initiator to the liquid components (A) and (D) to (G) shown in Tables 1 to 7. Next, component (C) and component (B) were weighed and added in the order shown in Tables 1 to 7, respectively, and finally stirring was performed to prepare the thermosetting compositions. A stirrer capable of stirring by rotation and revolution was used. The rotation speed was 1000 rpm and the revolution speed was 2000 rpm. The rotation time was 1 minute.

[0172] The proportions I and II shown in Tables 1 to 7 represent the following proportions: proportion I = (total content of component (α), which is a component contained in components (A) and (D) to (G) and has a melting point of -5°C or higher) / (total content of components (A) and (D) to (G)) x 100 proportion II = (total content of components (B) and (C)) / (total content of components (A) to (G)) x 100

[0173] The following were used as component (A): Adamantyl methacrylate (MADMA, manufactured by Osaka Organic Chemical Industry Co., Ltd., viscosity at 25°C: 5 mPa·s, melting point Tm (hereinafter sometimes simply referred to as Tm) < -15°C) Adamantyl acrylate (Adamantate M104, manufactured by Idemitsu Kosan Co., Ltd., viscosity at 25°C: 10 mPa·s, Tm < -15°C) Cyclohexyl methacrylate (Light Ester CH, manufactured by Kyoeisha Chemical Co., Ltd., viscosity at 25°C: 5 mPa·s, Tm < -15°C) 1-Isobornyl methacrylate (IB-X, manufactured by Kyoeisha Chemical Co., Ltd., viscosity at 25°C: 5 mPa·s, Tm < -15°C) 1-Isobornyl acrylate (SR506, manufactured by Arkema K.K., viscosity at 25°C: 5 mPa·s, Tm < -15°C) Adamantyl dimethacrylate (produced by the method described in paragraph 0067 of JP 2010-159410, viscosity at 25°C: 10 mPa·s, Tm<-15°C) Tricyclodecane dimethanol dimethacrylate (product name DCP, manufactured by Shin-Nakamura Chemical Co., Ltd., viscosity at 25°C: 110 mPa·s, Tm<-15°C) Tricyclodecane dimethanol diacrylate (product name A-DCP, manufactured by Shin-Nakamura Chemical Co., Ltd., viscosity at 25°C: 135 mPa·s, Tm<-15°C)

[0174] The viscosity of component (A) was measured using a melt viscoelasticity analyzer Physica MCR301 (manufactured by Anton Paar) under the following conditions at 10 s. －１ Measurement method: Coaxial cylinder rotational viscosity measurement method (based on JIS Z8803:2011) Plate diameter: 25 mmφ, Temperature: 25°C, Shear rate: 10 s －１

[0175] The melting points (Tm) of component (A) and components (D) to (F) described below were measured in accordance with JIS K7122-1987 by measuring the heat of crystallization when each component was cooled, and the peak temperature of the transition curve was taken as the melting point. A differential scanning calorimeter (DSC) (manufactured by PerkinElmer) was used as the measuring device.

[0176] The following was used as component (B): Hereinafter, methacrylsilane surface treatment was carried out using KBM-503 (3-methacryloxypropyltrimethoxysilane, manufactured by Shin-Etsu Chemical Co., Ltd.) with stirring to coat the silica surface uniformly. CRS1085-SF630: Spherical silica with an average particle size (D50) of 15 μm (surface treated with methacrylsilane) (manufactured by Tatsumori Co., Ltd.) CRS1035-LER4: Spherical silica with an average particle size (D50) of 2 μm (surface treated with methacrylsilane) (manufactured by Tatsumori Co., Ltd.) SP40HM: Spherical silica with an average particle size (D50) of 13 μm (surface treated with methacrylsilane) (manufactured by Nippon Steel Chemical & Material Co., Ltd.) S430-5PHM: Spherical silica with an average particle size (D50) of 5 μm (surface treated with methacrylsilane) (manufactured by Nippon Steel Chemical & Material Co., Ltd.) FB-304HM: Spherical silica with an average particle size (D50) of 11 μm (surface treated with methacrylsilane) (manufactured by Denka Company Limited)

[0177] The average particle size (D50) of component (B) was measured using a laser diffraction particle size distribution analyzer SALD-300V (manufactured by Shimadzu Corporation). Component (B) was dispersed in a toluene solvent, and the amount was increased from a small amount to an amount at which the scattering intensity could be measured, and the concentration was appropriately adjusted to a concentration at which particle size measurement was possible, and the weight of particles added was determined.

[0178] The following was used as component (C): PFC310: titanium oxide, average primary particle size: 0.2 μm (manufactured by Ishihara Sangyo Kaisha, Ltd.)

[0179] The average primary particle size of component (C) was determined by dispersing component (C) in ethylene glycol, preparing a frozen section, depositing gold on the section, and measuring the maximum lengths of 150 primary particles per field of view in five locations of 0.25 μm × 0.25 μm using a scanning electron microscope, and then calculating the arithmetic average.

[0180] The following were used as component (D): G: glycidyl methacrylate (manufactured by Kyoeisha Chemical Co., Ltd., Tm<-15°C) P-1M: 2-methacryloyloxyethyl acid phosphate (manufactured by Kyoeisha Chemical Co., Ltd., Tm<-15°C) SA: 2-methacryloyloxyethyl succinate (manufactured by Kyoeisha Chemical Co., Ltd., Tm<-15°C)

[0181] The following were used as component (E): Stearyl methacrylate (Light Ester S, manufactured by Kyoeisha Chemical Co., Ltd., Tm = 20°C) Stearyl acrylate (product name Light Acrylate S-A, manufactured by Kyoeisha Chemical Co., Ltd., Tm = 35°C) Lauryl acrylate (product name Light Acrylate L-A, manufactured by Kyoeisha Chemical Co., Ltd., Tm = 4°C)

[0182] The following were used as component (F): A-DON-N: 1,10-decanediol diacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd., Tm=20°C) 3000MK: epoxy ester compound represented by the following formula (i) (manufactured by Kyoeisha Chemical Co., Ltd., Tm<-15°C)

[0183] CN2283: Polyester acrylate oligomer (manufactured by Arkema, Tm<-15°C) 1,9ND-A: 1,9-nonanediol diacrylate (manufactured by Osaka Organic Chemical Industry Ltd., Tm=20°C) BPE-80N: Bifunctional ethoxylated bisphenol A-diacrylate represented by the following formula (manufactured by Shin-Nakamura Chemical Co., Ltd., average value of e+f is 2.3, Tm<-15°C)

[0184] The following MMA-Butyl-MMA terpolymer was used as component (G).LA4285: methyl methacrylate-n-butyl acrylate block copolymer manufactured by Kuraray Co., Ltd., in which, based on all structural units, the proportion of n-butyl acrylate structural units (G2) was 50 mol%, and the proportion of methyl methacrylate structural units (G1) was 50 mol%. LA2140: methyl methacrylate-n-butyl acrylate block copolymer manufactured by Kuraray Co., Ltd., in which, based on all structural units, the proportion of n-butyl acrylate structural units (G2) was 80 mol%, and the proportion of methyl methacrylate structural units (G1) was 20 mol%. LA2270: methyl methacrylate-n-butyl acrylate block copolymer manufactured by Kuraray Co., Ltd., in which, based on all structural units, the proportion of n-butyl acrylate structural units (G2) was 60 mol%, and the proportion of methyl methacrylate structural units (G1) was 40 mol%. LA2330: Kuraray Co., Ltd., methyl methacrylate-n-butyl acrylate block copolymer, with a ratio of n-butyl acrylate structural units (G2) of 80 mol% and methyl methacrylate structural units (G1) of 20 mol% based on all structural units, Mw: 85,000, Mn: 105,000, Mw / Mn: 1.2 LA3320: Kuraray Co., Ltd., methyl methacrylate-n-butyl acrylate block copolymer, with a ratio of n-butyl acrylate structural units (G2) of 80 mol% and methyl methacrylate structural units (G1) of 20 mol% based on all structural units, Mw: 130,000, Mn: 100,000, Mw / Mn: 1.3 LA3710: Kuraray Co., Ltd., methyl methacrylate-n-butyl acrylate block copolymer A5300: NOF Corporation, a graft copolymer in which a butyl acrylate-methyl methacrylate random copolymer (side chain) is graft polymerized onto an ethylene-ethyl acrylate copolymer (main chain). EB050S: Japan Polyethylene Co., Ltd., an ethylene-methyl acrylate random copolymer, in which the proportion of n-butyl acrylate structural units (G2) relative to all structural units is 0 mol%, and the proportion of methyl methacrylate structural units (G1) is 24 mol%. EB230X: Japan Polyethylene Co., Ltd., an ethylene-methyl acrylate random copolymer, in which the proportion of n-butyl acrylate structural units (G2) relative to all structural units is 0 mol%, and the proportion of methyl methacrylate structural units (G1) is 15 mol%.

[0185] [Characteristics Evaluation] The following items were measured and evaluated, and the results are shown in Tables 1 to 7. (Solubility) ○: When component (G) was added to the liquid components (A) and (D) to (F) in a proportion of 10% by mass and stirred for one day or more, no visible solubility of 1 mm was observed. ３ x: When 10% by mass of component (G) was added to the liquid components (A) and (D) to (F) and the mixture was stirred for one day or more, no insoluble component of component (G) of 1 mm or less was observed by visual inspection. ３ A certain amount of insoluble component (G) was confirmed.

[0186] (Evaluation of Storage Stability) The storage stability was measured using the following method and evaluation criteria. First, 5 kg of the obtained thermosetting composition was placed in a cylindrical container with a bottom diameter of 186 mm, and left in a freezer at −10° C. for 90 days. After 90 days, the temperature of the container was returned to room temperature, and a storage test was conducted in which the container was left for an additional 3 days. After 3 days, the thermosetting composition contained in the container was sampled from near the liquid surface, and the viscosity was measured using the same method as described in the above section "Viscosity Measurement of Thermosetting Composition." Using the viscosity measured for the thermosetting composition before the storage test as the reference, a case in which the viscosity reduction of the thermosetting composition after the storage test was within 20% was evaluated as "Good," and a case in which the reduction was greater than that was evaluated as "Poor." That is, if the decrease in viscosity of the thermosetting composition after the standing test exceeds 20%, this indicates that the resin component and the inorganic component contained in the thermosetting composition are separated during the standing test, and the content of the inorganic component contained in the supernatant of the thermosetting composition is lower than that of the thermosetting composition before the standing test.

[0187] (Production of Molded Article 1) The above-described thermosetting composition was subjected to LIM molding under the following conditions to obtain a molded article (cured product) 1. The mold used was a mold having a width of 10 mm, a length of 50 mm, and a thickness of 1 mm, and a vent portion at the flow end having a width of 5 mm, a length of 10 mm, and a thickness of 0.03 mm.

[0188] LIM molding was carried out under the following conditions: Molding machine: Liquid thermosetting resin injection molding machine LA-40S (manufactured by Sodick Co., Ltd.) Measurement with the plunger of the molding machine: 1 cm ３ Low-temperature flow path temperature: 15°C Flow path and heat blocking method: Use of shut-off nozzle High-temperature flow path temperature and cavity temperature: 135°C Filling time: 5 seconds Filling pressure: 10 MPa or less (filling time takes priority) Dwell time: 15 seconds Dwell pressure: 15 MPa Curing time: 90 seconds

[0189] (Evaluation of Filling Ability) When filling the thermosetting composition for producing the molded article 1 described above, the filling ability was visually confirmed. When no voids occurred and no unfilled areas occurred, it was evaluated as ○. When voids or unfilled areas occurred, it was evaluated as △. When voids occurred and unfilled areas occurred, it was evaluated as ×.

[0190] (Evaluation of the Presence or Absence of Burrs) The obtained molded article 1 was visually evaluated for the presence or absence of burrs. A case where there were no burrs beyond the end of the vent and no burrs were present in areas other than the vent was rated as ○. A case where there were burrs beyond the end of the vent or in areas other than the vent was rated as △. A case where there were burrs beyond the end of the vent and burrs were present in areas other than the vent was rated as ×.

[0191] (Production of Molded Article 2) The above-described thermosetting composition was subjected to LTM molding under the following conditions to obtain molded article (cured product) 2. A mold having dimensions of 50 mm length, 50 mm width, and 2 mm thickness was used. LTM molding was performed under the following conditions. Molding machine: Liquid transfer molding machine G-Line (manufactured by Apic Yamada Co., Ltd.) Measuring amount with the plunger of the molding machine: 6 cm ３ Flow path temperature in low temperature area: 25°C Flow path and blocking method: Manual blocking using a syringe Flow path temperature and cavity temperature in high temperature area: 150°C Filling time: 5 seconds Filling pressure: 15 MPa or less (filling time takes priority) Dwell time: 15 seconds Dwell pressure: 15 MPa Curing time: 90 seconds

[0192] (Measurement of Light Reflectance) The reflectance of the obtained molded article 2 was measured using an integrating sphere spectrophotometer CE-7000A (manufactured by Gretagmacbeth) in the wavelength range of 400 to 700 nm under the conditions of reflectance measurement mode, 10-degree field of view, diffused illumination / light reception in an 8-degree direction, color measurement area 5 mm × 10 mm, and including specular reflection and ultraviolet light, and the light reflectance of the molded article 2 at 450 nm was determined and evaluated according to the following criteria: ○: Light reflectance of 93.5% or more ×: Light reflectance of less than 93.5%

[0193] (Evaluation of heat resistance) After the above-mentioned measurement of light reflectance (referred to as initial reflectance), the molded article 2 was heated at 180°C for 72 hours. After heating, the reflectance was measured in the same manner as in the above-mentioned measurement of light reflectance, and the light reflectance of the molded article 2 at 450 nm (referred to as reflectance after heating) was determined. The difference between the initial reflectance and the reflectance after heating was divided by the initial reflectance, and the absolute value of the percentage was expressed as a percentage of less than 5%, whereby it was evaluated as ○, 5% or more but less than 10%, whereby it was evaluated as △, and whereby it was 10% or more, whereby it was evaluated as ×.

[0194] (Bending strain amount) The strain amount at break of the obtained molded article 2 was measured in accordance with JIS K7171:2016 and evaluated according to the following evaluation criteria: ○: The strain amount at break was 0.7% or more ×: The strain amount at break was less than 0.7%

[0195] (Bending shrinkage rate) For the obtained molded product 2 (a molded product having a length of 50 mm, a width of 50 mm, and a thickness of 2 mm), the length in the TD direction (the direction perpendicular to the molding direction) was measured using an image dimension measuring instrument (manufactured by KEYENCE Corporation, trade name "High Precision Image Dimension Meter"), and evaluated according to the following evaluation criteria. ○: The length in the TD direction is 49 mm or more ×: The length in the TD direction is less than 49 mm

[0196]

[0197]

[0198]

[0199]

[0200]

[0201]

[0202]

[0203] As shown in Tables 1 to 7, the thermosetting compositions of Examples 1 to 27 all suppressed warpage (visual observation / shrinkage rate) in the molded articles obtained after heat curing, resulting in good appearance. Furthermore, the molded articles obtained after heat curing had high reflectance and excellent heat resistance. Furthermore, the thermosetting compositions of Examples 1 to 27 exhibited no flash, good filling properties, and excellent moldability. On the other hand, the thermosetting compositions of Comparative Examples 1 to 3 exhibited warpage (visual observation or shrinkage rate) in the molded articles obtained, resulting in poor appearance. Furthermore, because component (G) used in the thermosetting compositions of Comparative Examples 4 to 8 had low solubility in components (A) and (D) to (F), it was not possible to evaluate storage stability or perform LIM molding of the thermosetting compositions.

[0204] The thermosetting composition and cured product according to one aspect of the present invention are suitable for use, for example, as a reflector for an optical semiconductor. The method for producing a molded article according to one aspect of the present invention is suitable for use, for example, in molding a reflector for an optical semiconductor.

[0205] Although several embodiments and / or examples of the present invention have been described in detail above, those skilled in the art will readily be able to make numerous modifications to these exemplary embodiments and / or examples without substantially departing from the novel teachings and advantages of the present invention. Accordingly, these numerous modifications are within the scope of the present invention. The contents of all documents cited in this specification and of the applications from which this application claims priority under the Paris Convention are incorporated by reference in their entirety.

Claims

1. A thermosetting composition comprising the following components (A) to (C), the following component (G), and one or more selected from the group consisting of the following components (D) to (F): (A) a monofunctional or polyfunctional (meth)acrylate compound having, as an ester substituent, a substituted or unsubstituted group having an alicyclic hydrocarbon group having 6 or more ring carbon atoms, and having a viscosity of 1 to 300 mPa·s at 25°C; (B) spherical silica; (C) a white pigment; (D) a monofunctional (meth)acrylate compound having, as an ester substituent, a group having (meth)acrylic acid or a polar group; (E) a monofunctional (meth)acrylate compound having, as an ester substituent, a group other than the ester substituent of component (A) and the ester substituent of component (D); (F) a polyfunctional (meth)acrylate compound having, as an ester substituent, a group other than the ester substituent of component (A); (G) a block copolymer comprising at least one block composed of a repeating unit represented by the following formula (G1) and at least one block composed of a repeating unit represented by the following formula (G2): (In formula (G1), R ４０１ In formula (G2), R is a hydrogen atom or a methyl group. ４０２ is a hydrogen atom or a methyl group. ４０３ represents an alkyl group having 2 to 18 carbon atoms; ４１１ OR ４１２ , or -R ４１３ S.R. ４１４ It is. ４１１ and R ４１３ are each independently an alkylene group having 1 to 30 carbon atoms. ４１２ and R ４１４ are each independently an alkyl group having 1 to 30 carbon atoms.

2. The thermosetting composition according to claim 1, wherein the content of said component (C) is 1 to 20 mass % based on 100 mass % in total of said components (A) to (G).

3. The thermosetting composition according to claim 1 or 2, wherein the substituted or unsubstituted alicyclic hydrocarbon group of component (A) having 6 or more ring carbon atoms is one or more groups selected from the group consisting of a substituted or unsubstituted adamantyl group, a substituted or unsubstituted norbornyl group, a substituted or unsubstituted isobornyl group, a substituted or unsubstituted tricyclodecanyl group, a substituted or unsubstituted tricyclodecanyl group, and a substituted or unsubstituted dicyclopentanyl group.

4. A thermosetting composition according to any one of claims 1 to 3, wherein the component (B) is spherical silica which has been surface-treated with an acrylsilane or a methacrylsilane.

5. The thermosetting composition according to any one of claims 1 to 4, wherein the average particle size (D50) of said component (B) is 0.1 to 100 µm.

6. A thermosetting composition according to any one of claims 1 to 5, wherein the content of components contained in said components (A) and (D) to (F) and having a melting point of -5°C or higher is 40 mass% or more based on 100 mass% of the total of said components (A) and (D) to (F).

7. A thermosetting composition according to any one of claims 1 to 6, wherein the total content of components (B) to (C) is 85 mass% or less, based on 100 mass% of the total of components (A) to (G).

8. A method for manufacturing a molded product, comprising the steps of: supplying the thermosetting composition according to any one of claims 1 to 7 into a plunger; filling a molded product section of a mold with the supplied thermosetting composition by means of the plunger; thermosetting the filled thermosetting composition within the molded product section; and extruding the thermoset resin.

9. The method for producing a molded product according to claim 8, wherein the temperature of the mold portion constituting the molded product portion is 100 to 180°C.

10. A method for manufacturing a molded product according to claim 8 or 9, in which a flow path whose temperature is controlled to 50°C or less is provided between the plunger and the molded product portion, and the filling is carried out via the flow path.

11. The method for producing a molded article according to claim 10, further comprising a gate system in the flow path for blocking the flow of the thermosetting composition and the transfer of heat.

12. The method for manufacturing a molded product according to claim 11, wherein the filling is carried out by opening a gate of the gate system, and the heat curing is completed by applying a pressure hold, and after the pressure hold, the gate of the gate system is closed.

13. The method for producing a molded product according to any one of claims 8 to 12, wherein the filling step and the heat curing step are carried out for 0.2 to 3 minutes.

14. A cured product produced using the thermosetting composition according to any one of claims 1 to 7.

15. The cured product according to claim 14, which is a molded article.