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

Abstract

A thermosetting composition contains (A) a compound represented by formula (A), (B) a thermal polymerization initiator, and (C) a bromine-based flame retardant. (In formula (A), R1 are each independently a hydrogen atom or a methyl group. R2 are each independently a single bond or a C1-20 alkylene group. Z is a substituted or unsubstituted alicyclic hydrocarbon group having 6-12 ring carbon atoms. n is 1 or 2. When n is 2, the two R1 and the two R 2 may be the same or different.)

Description

Thermosetting composition, method for producing molded product, and cured product

[0001] The present invention relates to a thermosetting composition, a method for producing a molded article, and a cured product. Specifically, the present invention relates to a thermosetting composition that has excellent flame retardancy and is capable of achieving both a high glass transition temperature and a low viscosity, a method for producing a molded article, and a cured product.

[0002] In recent years, the density and integration of electrical and electronic components have become increasingly high, necessitating improved reliability for each component. To improve the reliability of each component, attempts have been made to suppress external environmental influences, such as physical factors (e.g., vibration and dropping) and chemical factors (e.g., ultraviolet light, moisture, and salt), by, for example, resin-encapsulating the entire printed circuit board on which electrical and electronic components are soldered to form a circuit, or by encapsulating individual electrical components such as coils with resin. Thermosetting materials are used as materials for such encapsulants. The use of polymers with silicone, polyether, and isocyanate functional groups, as well as urethane resins, has been proposed as thermosetting resins (see, for example, Patent Documents 1 to 4). Furthermore, injection molding of thermosetting materials containing acrylic resins has been proposed as a technology for improving productivity (see, for example, Patent Documents 5 and 6).

[0003] Japanese Patent Application Laid-Open No. 08-272208 Japanese Patent Application Laid-Open No. 2008-280414 International Publication No. 2009 / 107301 Japanese Patent Application Laid-Open No. 2003-34709 International Publication No. 2022 / 215708 International Publication No. 2022 / 215716

[0004] However, it has been found that there is room for further improvement in the thermosetting compositions according to conventional techniques, including those described in Patent Documents 1 to 6, from the viewpoint of achieving excellent flame retardancy and also achieving both a high glass transition point and a low viscosity.

[0005] An object of the present invention is to provide a thermosetting composition that is excellent in flame retardancy and that is capable of achieving both a high glass transition point and a low viscosity, a method for producing a molded article, and a cured product.

[0006] As a result of extensive investigations, the present inventors have found that a thermosetting composition containing a specific (meth)acrylate and a specific flame retardant has excellent flame retardancy and can simultaneously achieve a high glass transition point and a low viscosity, and have completed the present invention.

[0007] According to the present invention, the following thermosetting compositions and the like can be provided: 1. A thermosetting composition comprising: (A) a compound represented by the following formula (A), (B) a thermal polymerization initiator, and (C) a bromine-based flame retardant. (In formula (A), R １ are each independently a hydrogen atom or a methyl group. ２ are each independently a single bond or an alkylene group having 1 to 20 carbon atoms. Z is a substituted or unsubstituted alicyclic hydrocarbon group having 6 to 12 ring carbon atoms. n is 1 or 2. When n is 2, two R １ and two R ２ may be the same or different. 2. The thermosetting composition according to 1, further comprising (D) a flame retardant aid. 3. The thermosetting composition according to 1 or 2, further comprising (E) a filler. 4. A method for producing a molded article, comprising subjecting the thermosetting composition according to any one of 1 to 3 to molding. 5. The method for producing a molded article according to 4, wherein the molding is injection molding. 6. A cured product produced using the thermosetting composition according to any one of 1 to 3. 7. The cured product according to 6, which is a molded product. 8. The cured product according to 6 or 7, which is an encapsulant.

[0008] According to the present invention, it is possible to provide a thermosetting composition that has excellent flame retardancy and is capable of achieving both a high glass transition point and a low viscosity, a method for producing a molded article, and a cured product.

[0009] 1 is a schematic cross-sectional view of a filling device of a molding machine that can be used in a method for manufacturing a molded article according to an embodiment. 2 is a schematic cross-sectional view of a mold that can be used in a method for manufacturing a molded article according to an embodiment. 3 is a diagram showing an example of the relationship between the viscosity of a thermosetting composition and time.

[0010] The thermosetting composition, the method for producing a molded article, and the cured product of the present invention are described in detail below. In this specification, "x to y" represents a numerical range of "x or more and y or less." The upper and lower limits of the numerical ranges can be combined arbitrarily. Furthermore, among the individual embodiments of the aspects of the present invention described below, two or more embodiments that are not mutually exclusive can be combined, and an embodiment combining two or more embodiments is also an embodiment of the aspects 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 this specification, the "number of atoms XX to YY" in the expression "a substituted or unsubstituted ZZ group having the number of atoms XX to YY" represents the number of atoms when the ZZ group is unsubstituted, and does not include the number of atoms of substituents when the ZZ group is substituted. Here, "YY" is larger than "XX", and "XX" and "YY" each represent an integer of 1 or more.

[0013] 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, an oxirane group, a methacryloyloxy group, an acryloyloxy group, and the like. 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, and the like. 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, and the like. Examples of the halogen atom include a fluorine atom, a bromine atom, an iodine atom, and the like.

[0014] In the case of "substituted or unsubstituted," "unsubstituted" means that the group is not substituted with the above-mentioned substituents and has a hydrogen atom bonded thereto.

[0015] 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 methacryloyl and acryloyl groups are collectively referred to as (meth)acryloyl groups.

[0016] 1. Thermosetting Composition A thermosetting composition according to one embodiment of the present invention comprises the following components (A) to (C): (A) a compound represented by the following formula (A), (B) a thermal polymerization initiator, and (C) a brominated flame retardant.

[0017]

[0018] In formula (A), R １ are each independently a hydrogen atom or a methyl group. ２ are each independently a single bond or an alkylene group having 1 to 20 carbon atoms. Z is a substituted or unsubstituted alicyclic hydrocarbon group having 6 to 12 ring carbon atoms. n is 1 or 2. When n is 2, two R １ and two R ２ may be the same or different.

[0019] The thermosetting composition according to this embodiment has excellent flame retardancy and can achieve both a high glass transition point and a low viscosity. The thermosetting composition has excellent heat resistance due to its high glass transition point. Furthermore, despite containing a flame retardant, its viscosity is low, resulting in not only excellent flame retardancy but also excellent processing accuracy (molding accuracy). In particular, when the thermosetting composition is used as a sealing material, its low viscosity allows it to suitably conform to the shape of the parts to be sealed, improving sealing performance. Therefore, it can also be used to suitably accommodate miniaturization and high density of the parts to be sealed. Furthermore, because of its excellent heat resistance and flame retardancy, it is stable even in high-temperature environments, improving sealing reliability. From one perspective, according to this embodiment, even when the parts to be sealed are small or dense, high-precision sealing can be achieved using a thermosetting composition with excellent heat resistance and flame retardancy.

[0020] (Component (A)) The thermosetting composition of this embodiment contains a compound represented by the above formula (A). By containing component (A), the glass transition temperature of the thermosetting composition can be increased.

[0021] In formula (A), R １ are each independently a hydrogen atom or a methyl group. １ is a hydrogen atom. １ It is a methyl group. ２ are each independently a single bond or an alkylene group having 1 to 20 carbon atoms. ２ is a single bond. ２ and an alkylene group having 1 to 20 carbon atoms. The number of carbon atoms in the alkylene group may be, for example, 1 to 20, 1 to 15, 1 to 12, 1 to 10, 1 to 8, 1 to 5, 1 to 3, 1 to 2, or 1.

[0022] Z is a substituted or unsubstituted monovalent or divalent alicyclic hydrocarbon group having 6 to 12 ring carbon atoms. Examples of Z include a substituted or unsubstituted adamantane skeleton, a substituted or unsubstituted norbornane skeleton, a substituted or unsubstituted isobornane skeleton, and a substituted or unsubstituted dicyclopentadiene skeleton.

[0023] n is 1 or 2. When n is 2, two R １ and two R ２ may be the same or different. Preferred examples of component (A) include compounds represented by the following formulae (I) to (IV).

[0024]

[0025]

[0026] In formulas (I) to (VIII), R １ and R ２ are the same as in formula (A), and the explanation for formula (A) is incorporated herein by reference. 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. A represents an integer of 0 to 15, B represents an integer of 0 to 8, C represents an integer of 0 to 11, D represents an integer of 0 to 15, E represents an integer of 0 to 14, F represents an integer of 0 to 7, G represents an integer of 0 to 10, and H represents an integer of 0 to 14. When A to H are 0, only hydrogen atoms are bonded to the alicyclic hydrocarbon group (Z), in addition to the group in parentheses in formula (A).

[0027] 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 (VIII). 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.

[0028] The component (A) may be used alone or in combination of two or more.

[0029] (Component (B)) The thermosetting composition of this embodiment contains component (B), a thermal polymerization initiator. A thermal polymerization initiator is a compound that generates active species such as radicals or cations when heated. By including component (B), a stable molded product can be obtained (for example, the curing time can be shortened and the curing time margin can be narrowed). Component (B) is not particularly limited, but examples include radical polymerization initiators.

[0030] 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.

[0031] Specific examples of ketone peroxides include methyl ethyl ketone peroxide, methyl isobutyl ketone peroxide, acetylacetone peroxide, cyclohexanone peroxide, and methylcyclohexanone peroxide.

[0032] Specific examples of hydroperoxides include 1,1,3,3-tetramethylbutyl hydroperoxide, cumene hydroperoxide, t-butyl hydroperoxide, p-menthane hydroperoxide, and diisopropylbenzene hydroperoxide.

[0033] 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.

[0034] Specific examples of dialkyl peroxides include dicumyl peroxide, dilauroyl 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.

[0035] 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.

[0036] 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- Examples of the peroxyalkyl peroxysilane include 3,5,5-trimethylhexanate, t-amylperoxy-3,5,5-trimethylhexanoate, t-butylperoxy-3,5,5-trimethylhexanoate, t-butylperoxyacetate, t-butylperoxybenzoate, dibutylperoxytrimethyladipate, 2,5-dimethyl-2,5-di-2-ethylhexanoylperoxyhexane, t-hexylperoxy-2-ethylhexanoate, t-hexylperoxyisopropyl monocarbonate, t-butylperoxylaurate, t-butylperoxyisopropyl monocarbonate, t-butylperoxy-2-ethylhexyl monocarbonate, and 2,5-dimethyl-2,5-dibenzoylperoxyhexane.

[0037] 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.

[0038] From the viewpoint of the heat resistance of the insert, a thermal polymerization initiator having a one-hour half-life temperature of 30 to 130°C is preferred as component (B).

[0039] Specifically, among the above compounds, diacyl peroxides, peroxycarbonates, peroxyesters, and peroxyketals are preferred. Component (B) may be used singly or in combination of two or more.

[0040] In one embodiment, the content of component (B) in the thermosetting composition is, relative to 100 parts by mass of component (A), 0.01 parts by mass or more, 0.05 parts by mass or more, 0.1 parts by mass or more, 0.5 parts by mass or more, or 0.7 parts by mass or more, and is 10 parts by mass or less, 5 parts by mass or less, 3 parts by mass or less, 2 parts by mass or less, 1.8 parts by mass or less, 1.5 parts by mass or less, or 1.3 parts by mass or less.

[0041] (Component (C)) The thermosetting composition according to this embodiment includes component (C), a brominated flame retardant. A brominated flame retardant refers to a flame retardant containing a bromine atom (Br). By including component (C) as the flame retardant, even if the amount of component (C) is small, the flame retardancy of the thermosetting composition containing component (A) can be efficiently improved. Component (C) is not particularly limited, but examples thereof include ethylene bis(pentabromophenyl), tris(tribromoneopentyl)phosphate, tris-dibromopropyl isocyanurate, 2,4,6-tris(2,4,6-tribromophenoxy)-1,3,5-triazine, brominated epoxy oligomer, ethylene bis(pentabromophenyl), ethylene bis(tetrabromophthalimide), decabromodiphenyl ether, tetrabromobisphenol A, 2,2-bis[4'-(2",3"-dibromopropyloxy)-3',5'-dibromophenyl]propane, and the like.

[0042] The component (C) may be used alone or in combination of two or more.

[0043] In one embodiment, the content of component (C) in the thermosetting composition is, relative to 100 parts by mass of the total of components (A) and (B), 0.1 parts by mass or more, 0.5 parts by mass or more, 0.7 parts by mass or more, 1 part by mass or more, 2 parts by mass or more, 3 parts by mass or more, 5 parts by mass or more, 7 parts by mass or more, 10 parts by mass or more, 12 parts by mass or more, 15 parts by mass or more, or 17 parts by mass or more, and is 100 parts by mass or less, 90 parts by mass or less, 80 parts by mass or less, 70 parts by mass or less, 65 parts by mass or less, 60 parts by mass or less, or 55 parts by mass or less.

[0044] (Component (D)) In one embodiment, the thermosetting composition further contains component (D) a flame retardant aid. Component (D) is not particularly limited, but examples thereof include antimony compounds such as antimony trioxide, antimony pentoxide, and sodium antimonate; zinc borate, polytetrafluoroethylene, metal oxides, silicon dioxide, hydrotalcite, magnesium bicarbonate, zinc oxide, aluminum oxide, magnesium oxide, zirconium oxide, vanadium oxide, molybdenum oxide and surface-treated products thereof (those whose surfaces are coated with silane compounds or the like), melamine, melamine cyanurate, pentaerythritol, dipentaerythritol, tripentaerythritol, monopentaerythritol, and tris(2-hydroxyethyl)isocyanurate. Among these, antimony compounds are preferred.

[0045] The component (D) may be used alone or in combination of two or more.

[0046] In one embodiment, the content of component (D) in the thermosetting composition is 0 parts by mass, 0 parts by mass or more, 0.1 parts by mass or more, 0.2 parts by mass or more, 0.5 parts by mass or more, 0.7 parts by mass or more, or 1 part by mass or more, and is 20 parts by mass or less, 15 parts by mass or less, 13 parts by mass or less, 10 parts by mass or less, 8 parts by mass or less, or 5 parts by mass or less, relative to 100 parts by mass of the total of components (A) and (B).

[0047] (Component (E)) In one embodiment, the thermosetting composition further comprises component (E) a filler. Component (E) is not particularly limited, but examples thereof include silver, gold, silicon, silicon carbide, silica, copper oxide, iron oxide, cobalt oxide, titanium carbide, cerium oxide, ITO (indium tin oxide), hydroxyapatite, carbon black, graphene, graphene oxide, single-walled carbon nanotubes, multi-walled carbon nanotubes, fullerene, diamond, mesoporous carbon, alumina, aluminum nitride, boron nitride, zinc oxide, and magnesium oxide.

[0048] The component (E) may be used alone or in combination of two or more.

[0049] In one embodiment, the content of component (E) in the thermosetting composition is 0 parts by mass, 0 parts by mass or more, 1 part by mass or more, 5 parts by mass or more, 10 parts by mass or more, 15 parts by mass or more, or 20 parts by mass or more, and is 2000 parts by mass or less, 1500 parts by mass or less, 1000 parts by mass or less, 500 parts by mass or less, 300 parts by mass or less, or 100 parts by mass or less, relative to 100 parts by mass of the total of components (A) and (B).

[0050] (Component (F)) In one embodiment, the thermosetting composition further comprises component (F) a non-alicyclic (meth)acrylate. Component (F) is not particularly limited, but examples thereof include 2,3-epoxypropyl methacrylate, 2-hydroxyethyl methacrylate, tetrahydrofurfuryl methacrylate, lauryl acrylate, 1,9-nonanediol diacrylate, 1,10-decanediol diacrylate, bifunctional ethoxylated bisphenol A-diacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd., "NK Ester BPE-80N"), polyester acrylate oligomer (manufactured by Arkema K.K., "CN2283"), ethoxylated (3) trimethylolpropane triacrylate (manufactured by Arkema K.K., "SR454 TFN"), ethoxylated (6) trimethylolpropane triacrylate (manufactured by Arkema K.K., "SR499 NS"), and ditrimethylolpropane tetraacrylate.

[0051] In one embodiment, the content of component (F) in the thermosetting composition is 1% by mass or more, 10% by mass or more, 20% by mass or more, 30% by mass or more, or 40% by mass or more, and 50% by mass or less, 40% by mass or less, 30% by mass or less, 20% by mass or less, or 10 parts by mass or less, relative to 100% by mass of the total of component (A) and component (F). When the thermosetting composition contains component (F), the standard for blending is 100 parts by mass of the total of component (A) and component (F).

[0052] (Other Components) The thermosetting composition of this embodiment may further contain components (other components) other than the above-described components (A) to (F), as long as the effects of the present invention are not impaired. Examples of other components include various additives. Examples of additives include antioxidants, light stabilizers, flame retardants other than brominated flame retardants, ultraviolet absorbers, plasticizers, colorants, antistatic agents, lubricants, release agents, leveling agents, and antifoaming agents. Known additives can be used as these additives.

[0053] Examples of antioxidants include phenol-based antioxidants, phosphorus-based antioxidants, sulfur-based antioxidants, vitamin-based antioxidants, lactone-based antioxidants, and amine-based antioxidants. One type of antioxidant may be used alone, or two or more types may be used in combination. When an antioxidant is contained, the content of the antioxidant may be, for example, 0.001 to 20 parts by mass per 100 parts by mass of the total of component (A) and component (B), so as not to impair the effects of the present invention.

[0054] Any light stabilizer (light resistance stabilizer) can be used, such as an ultraviolet absorber or a hindered amine light stabilizer, but a hindered amine light stabilizer is preferred. A single light stabilizer may be used, or two or more types may be used in combination. When a light stabilizer is contained, the content of the light stabilizer may be, for example, 0.001 to 20 parts by mass per 100 parts by mass of the total of component (A) and component (B), so as not to impair the effects of the present invention.

[0055] Examples of flame retardants other than brominated flame retardants include phosphorus-based flame retardants, nitrogen-based compounds, metal hydroxides, silicone-based flame retardants, organic alkali metal salts, and organic alkaline earth metal salts. When a flame retardant other than a brominated flame retardant is contained, the content of the flame retardant other than a brominated flame retardant may be, for example, 0.001 to 20 parts by mass per 100 parts by mass of the total of component (A) and component (B), so as not to impair the effects of the present invention. Furthermore, when a flame retardant other than a brominated flame retardant is contained, the content of the flame retardant other than a brominated flame retardant may be, for example, 0.001 to 50 parts by mass per 100 parts by mass of component (C), so as not to impair the effects of the present invention.

[0056] The plasticizer is not particularly limited, and examples thereof include phthalate esters, adipate esters, aliphatic dibasic acid esters, phosphate esters, ricinoleate esters, polyesters, acetate esters, sulfonamides, and pyromellitic esters. A single plasticizer may be used, or two or more may be used in combination. When a plasticizer is contained, the content of the plasticizer is, from the viewpoint of not impairing the effects of the present invention, for example, 1 to 50 parts by mass, preferably 10 to 35 parts by mass, and more preferably 15 to 30 parts by mass, relative to 100 parts by mass of the total of component (A) and component (B).

[0057] Examples of release agents include internal release agents. While there are no specific specifications for the internal release agent, aliphatic compounds are desirable. The aliphatic compound used as the internal 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 aliphatic compound does not vaporize during curing, generating bubbles in the product and causing poor appearance, and exhibits good release properties. Furthermore, by setting the melting point of the aliphatic compound to 180°C or lower, the solubility is improved, resulting in good appearance and release properties. Examples of release agents include magnesium stearate and zinc stearate. The release agents may be used alone or in combination of two or more. When a release agent is contained, the content of the release agent is 0.001 to 20 parts by mass per 100 parts by mass of the total of components (A) and (B).

[0058] In one embodiment, the thermosetting composition of this aspect is, for example, 40% by mass or more, 50% by mass or more, 60% by mass or more, 70% by mass or more, 80% by mass or more, 90% by mass or more, 95% by mass or more, 99% by mass or more, or substantially 100% by mass of the composition is: component (A), component (B), and component (C); component (A), component (B), component (C), and component (D); component (A), component (B), component (C), and component (E); component (A), component (B), component (C), component (D), and component (E); or component (A), component (B), component (C), component (D), component (E), and component (F). Note that "substantially 100% by mass" may contain inevitable impurities.

[0059] The method for producing the thermosetting composition described above is not particularly limited. The thermosetting composition can be prepared by mixing the above-mentioned components in a predetermined ratio. The mixing method is not particularly limited, and any known means such as a stirrer (mixer) can be used. In addition, the components can be mixed at room temperature, under cooling, or under heating, and under normal pressure, reduced pressure, or increased pressure.

[0060] 2. Manufacturing Method of Molded Article A manufacturing method of a molded article according to one aspect of the present invention includes molding a thermosetting composition according to one aspect of the present invention. According to this manufacturing method of a molded article, the low viscosity of the thermosetting composition results in excellent processing accuracy (molding accuracy). Furthermore, the resulting molded article has excellent flame retardancy and a high glass transition point (excellent heat resistance).

[0061] In one embodiment, a method for producing a molded article according to this aspect includes subjecting the thermosetting composition according to one aspect of the present invention to injection molding. In one embodiment, the method for producing a molded article includes the steps of: supplying the above-described thermosetting composition into a plunger (supply step); filling the supplied thermosetting composition using the plunger into a molded article portion (cavity) of a mold having a gauge pressure of −90 kPa or less (vacuum pressure of 10 kPa) and an oxygen content of 0.2 × cavity volume / 22.4 mol or less; or filling the supplied thermosetting composition using the plunger into a molded article portion (cavity) having a gauge pressure of −90 kPa or less (vacuum pressure of 10 kPa) and an oxygen content of 0.2 × cavity volume / 22.4 mol or less (filling step); and thermally curing the filled thermosetting composition within the molded article portion (curing step). The method for producing a molded article may also include a step of extruding the thermoset resin from the molded article portion (cavity) (demolding step).

[0062] In one embodiment, from the viewpoint of preventing only the resin component in the thermosetting composition 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.

[0063] By using the above-described thermosetting composition, when filling the inside of a mold under pressure, or when applying excessive dwell pressure after filling, the thermosetting composition can fill even a gap of 1 μm.

[0064] 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 60 to 190°C, and a molding time of 30 to 500 seconds, preferably a molding temperature of 70 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.

[0065] 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 60 to 190°C, and a molding time of 30 to 500 seconds, preferably at a molding temperature of 70 to 180°C, and a molding time of 20 to 180 seconds.

[0066] The molding machine preferably includes a plunger and a mold having a molded product portion, and further includes a shut-off nozzle.

[0067] FIG. 1 is a diagram showing one embodiment of a filling device of a molding machine capable of carrying out the injection molding method in the method for producing a molded product of the present invention. The molding machine of FIG. 1 is an injection molding machine having a plunger mechanism for extruding a thermosetting composition into a mold. The molding machine 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 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 the present invention. In another embodiment, the molding machine may also include an inert gas replacement device as a means connected to the fine hole for replacing the air in the cavity in the mold with an inert gas.

[0068] 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.

[0069] 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 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.

[0070] In the method of the present invention, a gate system is preferably provided in the flow path (flow path) between the plunger and the cavity during the process of filling the cavity in the mold with the thermosetting composition filled in the plunger. The molding method of the present invention will be described below with reference to FIG. 2. When the method of the present invention is carried out 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, thereby blocking the flow of the thermosetting composition and the exchange of heat. Examples of systems that can block the flow of the thermosetting composition and the exchange 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 the method of the present invention, the temperature of the mold 232 constituting the cavity is preferably set to 40°C or higher and 150°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.

[0071] 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.

[0072] The filling step is shown, for example, in FIG. 2(B). When injecting the thermosetting composition into the cavity, it is preferable to reduce the pressure inside the cavity by installing a vent to release air from the cavity or by providing a small hole connected to a pressure reducing device such as the vacuum pipe 240 in FIG. 2 that allows the pressure inside the cavity to be reduced. 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, and reducing the pressure inside the cavity is used to create an air-free state so that the cavity can be completely filled with the thermosetting composition. If this mechanism is not available, it is preferable to have a mechanism (e.g., a vent mechanism) that removes air from the cavity when the material is being filled. To prevent poor curing, the gauge pressure in the cavity when injecting the thermosetting composition into the cavity is preferably −90 kPa or less (vacuum pressure 10 kPa), and the amount of oxygen in the cavity is preferably 0.2 × cavity volume / 22.4 mol or less, or −90 kPa or less (vacuum pressure 10 kPa) and the amount of oxygen in the cavity is preferably 0.2 × cavity volume / 22.4 mol or less. A method for reducing the amount of oxygen in the cavity to 0.2 × cavity volume / 22.4 mol or less is preferably a method of degassing the cavity in the mold using a pressure reducing device connected to a fine hole for degassing the cavity, and replacing the air with an inert gas using an inert gas replacement device connected to a fine hole for replacing the air in the cavity in the mold with an inert gas. Furthermore, a sprueless method is preferred for reducing the pressure in the cavity. To mold the thermosetting composition, first, the movable mold 23 is brought close to the fixed mold 22, and the mold is clamped ( FIG. 2(A) ). The movement of the movable mold 23 is temporarily stopped at a position where the elastic member 238 of the movable mold 23 abuts against the elastic member 224 of the fixed mold 22 .

[0073] 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, 50°C or higher, preferably 50°C to 150°C, and particularly preferably 50°C to 120°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.

[0074] 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. 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 a 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 the dwell 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, the entire flow path is preferably maintained at a temperature of 10°C or more and 50°C or less, and particularly preferably at 30°C or less.

[0075] 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 the viscosity of the thermosetting composition and time in 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, which occurs when curing is complete. 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.

[0076] 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 at a low viscosity can result in 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. 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.

[0077] If the viscosity of the thermosetting composition in the cavity 21 can be detected, the dwell start time T can be determined. In this embodiment, the thermosetting composition begins to shrink at the same time as it thickens in the initial curing stage P2, so it is preferable to detect the time when the shrinkage begins. This allows the dwell start time T to be appropriately determined.

[0078] In the curing process, maintaining pressure under the above-described conditions prevents sink marks and distortion in the molded product and improves transferability. After a certain period of maintaining pressure, as shown in FIG. 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 the composition without leaving any uncured portions. The plunger 11 is then advanced to fill the cavity 21 of the mold 20 with the thermosetting composition, and the time required for filling is defined as t1. Once filling is complete, the plunger 11 stops. Furthermore, as the curing of the thermosetting composition begins, the thermosetting composition simultaneously contracts, causing the plunger 11, which had stopped after the filling process, to resume its forward movement. The time required from the completion of the filling process until the plunger 11 resumes its forward movement due to contraction is defined as t2. If the time required for further heating to completely cure the thermosetting composition is defined as t3, then t1 + t2 + t3 (the total time required for the filling process and the thermosetting process) is preferably 0.2 to 3 minutes. A time of 0.2 minutes to 2 minutes is more preferable. If it is less than 0.2 minutes, there is a risk that the curing will be incomplete, and if it is more than 3 minutes, it is not preferable from the viewpoint of mass productivity.

[0079] 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.

[0080] 3. Cured Product A cured product according to one aspect of the present invention is produced using the thermosetting composition according to one aspect of the present invention. The cured product according to this aspect has excellent processing precision (molding precision) due to the low viscosity of the thermosetting composition. Furthermore, the resulting molded product has excellent flame retardancy and a high glass transition point (excellent heat resistance). In one embodiment, the cured product is a molded product. In one embodiment, the cured product is a sealant. The cured product is not particularly limited, but can be suitably used, for example, to seal electronic circuit devices, electronic circuit boards, and the like.

[0081] Examples of the present invention will be described below, but the present invention is not limited to these examples.

[0082] The raw materials used in the examples and comparative examples are as follows. <Monomers> Component (A) (compound represented by formula (A)) Tricyclodecane dimethanol dimethacrylate (manufactured by Shin-Nakamura Scientific Co., Ltd., "NK Ester DCP") Tricyclodecane dimethanol acrylate (manufactured by Arkema K.K., "SR833 NS") 1-Isobornyl methacrylate (manufactured by Kyoeisha Chemical Co., Ltd., "Light Ester IB-X") 1-Adamantyl methacrylate (manufactured by Osaka Organic Chemical Industry Ltd., "ADMA")

[0083] Component (F) (Non-alicyclic acrylate) 2,3-epoxypropyl methacrylate (manufactured by NOF Corporation, "BLEMMER GH") 2-hydroxyethyl methacrylate (manufactured by Kyoeisha Co., Ltd., "Light Ester HO-250(N)") Tetrahydrofurfuryl methacrylate (manufactured by Kyoeisha Co., Ltd., "Light Ester THF(1000)") Lauryl acrylate (manufactured by Kyoeisha Co., Ltd., "Light Acrylate L-A") 1,9-nonanediol diacrylate (manufactured by Kyoeisha Co., Ltd., "Light Acrylate 1.9ND-A") 1,10-decanediol diacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd., "NK Ester A-DOD-N") Bifunctional ethoxylated bisphenol A-diacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd., "NK Ester BPE-80N") Polyester acrylate oligomer (manufactured by Arkema K.K., "CN2283") Ethoxylated (3) Trimethylolpropane triacrylate (manufactured by Arkema, "SR454 TFN") Ethoxylated (6) Trimethylolpropane triacrylate (manufactured by Arkema, "SR499 NS")

[0084] Component (B) (thermal polymerization initiator) 1,1,3,3-tetramethylbutyl peroxyneodecanoate (manufactured by NOF Corporation, "Perocta ND") Di-2-ethylhexyl peroxycarbonate (manufactured by NOF Corporation, "Perloyl OPP") Dilauroyl peroxide (manufactured by NOF Corporation, "Perloyl L") 1,1-di(t-amylperoxy)cyclohexane (manufactured by Arkema K.K., "Luperox 531")

[0085] Component (C) (brominated flame retardant) Ethylenebis(pentabromophenyl) (manufactured by Albemarle Japan Co., Ltd., "SAYTEX 8010") Tetrabromobisphenol A (manufactured by Tosoh Corporation, "Framecut 120G") 2,4,6-tris(2,4,6-tribromophenoxy)-1,3,5-triazine (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd., "Pyroguard SR-245"), "Pyroguard SR-720N", Dai-ichi Kogyo Seiyaku Co., Ltd., 2,2-bis[4'-(2",3"-dibromopropyloxy)-3',5'-dibromophenyl]propane Other flame retardants Aluminum hydroxide (manufactured by Nippon Light Metal Co., Ltd., "BF013STM")

[0086] Component (D) (flame retardant auxiliary): diantimony trioxide (manufactured by Nippon Seiko Co., Ltd., "PATOX-MK") Component (E) (filler): silica (manufactured by Denka Co., Ltd., "FB-304HM", fused silica (spherical), average particle size d50: 11 μm)

[0087] (Examples 1 to 28 and Comparative Examples 1 to 7) (1) Preparation of Thermosetting Compositions The raw materials were mixed by stirring to obtain the compositions shown in Tables 1 to 6, to obtain thermosetting compositions. Specifically, a stirring device configured to be capable of stirring by rotation and revolution was used. The rotation speed was set to 1000 rpm and the revolution speed to 2000 rpm. The rotation time (stirring time) was set to 1 minute.

[0088] (2) Production of Molded Article 1 The thermosetting composition of (1) above was subjected to LIM (Liquid Injection Molding) under the following conditions to obtain a cured molded article 1. The mold cavity size was 125 mm in length, 13 mm in width, and 3 mm in thickness. Molding machine: Liquid thermosetting resin injection molding machine LA-40S (manufactured by Sodick Co., Ltd.) Weighing with the plunger of the molding machine: 1.1 g Flow path temperature in the low-temperature section: 15°C Flow path and heat blocking method: Use of a shut-off nozzle Curing temperature: Temperatures shown in Tables 1 to 6 Filling pressure: 10 MPa or less Dwell time: 15 seconds Dwell pressure: 15 MPa Curing time: Time shown in Tables 1 to 6

[0089] (3) Production of Molded Article 2 The thermosetting composition of (1) above was poured into a mold 50 mm long, 50 mm wide, and 1 mm thick, and heated in an oven for 1 hour at the curing temperature shown in Tables 1 to 6 to obtain Molded Article 2.

[0090] <Test Methods and Evaluation Methods> (1) Material Viscosity Measured using a viscoelasticity measuring device Physica MCR301 (manufactured by Anton Paar) based on JIS K7117-2. (2) Flame Retardancy Molded Article 1 was subjected to a vertical flame test in accordance with the UL94 standard using a flame retardancy evaluation tester (HVUL Plastic UL Flame Test Chamber, manufactured by Atlas). Cases where it was judged to be V-0 grade were rated "A", and other cases were rated "B". (3) Glass Transition Point (Tg) For Molded Article 2, the viscoelasticity of the cured product was measured using a solid viscoelasticity measuring device ("DMA7100" manufactured by Hitachi High-Tech Science Corporation), and the peak of tan δ was calculated as Tg.

[0091] The results are shown in Tables 1 to 6. Tables 1 to 3 are divided by the content of filler (silica).

[0092]

[0093]

[0094]

[0095]

[0096]

[0097]

[0098] Tables 1 to 3 show that the Examples have both a high glass transition temperature (Tg) and a low viscosity (material viscosity) compared to the Comparative Examples. The Examples also have excellent flame retardancy. These effects were maintained even when the filler content was changed.

[0099] 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: (A) a compound represented by the following formula (A); (B) a thermal polymerization initiator; and (C) a brominated flame retardant. (In formula (A), R １ are each independently a hydrogen atom or a methyl group. ２ are each independently a single bond or an alkylene group having 1 to 20 carbon atoms. Z is a substituted or unsubstituted alicyclic hydrocarbon group having 6 to 12 ring carbon atoms. n is 1 or 2. When n is 2, two R １ and two R ２ may be the same or different.) 2. The thermosetting composition of claim 1, further comprising (D) a flame retardant synergist.

3. The thermosetting composition according to claim 1 or 2, further comprising (E) a filler.

4. A method for producing a molded article, comprising subjecting the thermosetting composition according to any one of claims 1 to 3 to molding.

5. The method for producing a molded product according to claim 4, wherein the molding is injection molding.

6. A cured product produced using the thermosetting composition according to any one of claims 1 to 3.

7. The cured product according to claim 6, which is a molded article.

8. The cured product according to claim 6 or 7, which is a sealing material.

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