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

Abstract

To provide a thermosetting composition that is excellent in flame retardancy and can achieve both a high glass transition temperature and low viscosity, a method for manufacturing a molded article, and a cured product.SOLUTION: A thermosetting composition contains (A) a compound represented by formula (A) in the figure, (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; and n is 1 or 2. When n is 2, the two R1 may be the same or different, and the two R2 may be the same or different.)SELECTED DRAWING: None

Description

[Technical Field]

[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 point and a low viscosity, a method for producing a molded article, and a cured product. [Background technology]

[0002] In recent years, the density and integration of electric and electronic components has increased, and there is a demand for improved reliability for each component. In order to improve the reliability of each component, attempts have been made to suppress the effects of external environments such as physical factors such as vibration and dropping, and chemical factors such as ultraviolet rays, moisture, and salt, by, for example, sealing the entire printed circuit board on which electrical and electronic components are soldered to form circuits with resin, or by sealing individual electrical components such as coils with resin. Thermosetting materials are used as materials for forming such sealing materials. As thermosetting resins, it has been proposed to use polymers having silicone, polyether, and isocyanate functional groups, and urethane resins (see, for example, Patent Documents 1 to 4). Furthermore, as a technique for improving productivity, it has been proposed to subject a thermosetting material containing an acrylic resin to injection molding (see, for example, Patent Documents 5 and 6). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 08-272208 [Patent Document 2] Japanese Patent Application Laid-Open No. 2008-280414 [Patent Document 3] International Publication No. 2009 / 107301 [Patent Document 4] Japanese Patent Application Laid-Open No. 2003-34709 [Patent Document 5] International Publication No. 2022 / 215708 [Patent Document 6] International Publication No. 2022 / 215716 Summary of the Invention [Problem to be solved by the invention]

[0004] However, it has been found that there is room for further improvement in the thermosetting compositions according to the prior art, 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. [Means for solving the problem]

[0006] As a result of extensive research, 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) A compound represented by the following formula (A): (B) a thermal polymerization initiator, and (C) Brominated flame retardants A thermosetting composition comprising: [ka] (In formula (A), R 1 are each independently a hydrogen atom or a methyl group. R 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 1and two R 2 may be the same or different.) 2. The thermosetting composition according to 1, further comprising (D) a flame retardant synergist. 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 article. 8. The cured product according to 6 or 7, which is a sealing material. [Effects of the Invention]

[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. [Brief explanation of the drawings]

[0009] [Figure 1] 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 product according to one embodiment. [Figure 2] FIG. 1 is a schematic cross-sectional view of a mold that can be used in a method for manufacturing a molded product according to one embodiment. [Figure 3] FIG. 2 is a graph showing an example of the relationship between the viscosity of a thermosetting composition and time. DETAILED DESCRIPTION OF THE INVENTION

[0010] The thermosetting composition, the method for producing a molded article, and the cured product of the present invention will be described in detail below. In this specification, "x to y" represents a numerical range of "not less than x and not more than y." The upper and lower limits of the numerical ranges can be combined in any way. Furthermore, among the individual embodiments of the aspects of the present invention described below, it is possible to combine two or more embodiments that are not mutually contradictory, and an embodiment that combines 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 XX to YY atoms" refers to the number of atoms when the ZZ group is unsubstituted, and does not include the number of 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 greater.

[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, and an acryloyloxy group. 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), and a hexyl group. 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, and a hexyloxy group. Examples of the halogen atom include a fluorine atom, a bromine atom, and an iodine atom.

[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 groups 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) Thermal polymerization initiator (C) Brominated flame retardants

[0017] [ka]

[0018] In formula (A), R 1 are each independently a hydrogen atom or a methyl group. R 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. Thermosetting compositions have excellent heat resistance due to their high glass transition temperature. In addition, despite containing a flame retardant, they have low viscosity, which not only provides excellent flame retardancy but also allows for excellent processing precision (molding precision). 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 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 high-density, 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. In one embodiment, R 1 is a hydrogen atom. 1 It is a methyl group. R 2 are each independently a single bond or an alkylene group having 1 to 20 carbon atoms. In one embodiment, R 2 is a single bond. Also, in one embodiment, R 2 It is an alkylene group having 1 to 20 carbon atoms. The number of carbon atoms in the alkylene group can 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] [ka]

[0025] [ka]

[0026] In formulas (I) to (VIII), R 1 and R 2 is the same as in formula (A), and the explanation given for formula (A) is applicable. 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) other than 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 to a carbon atom in the alicyclic hydrocarbon group of the compounds represented by formulae (I) to (VIII) by removing two hydrogen atoms from the same carbon atom. Examples of the alkyl group having 1 to 4 carbon atoms represented by U include a methyl group, an ethyl group, a propyl group (for example, an n-propyl group, an isopropyl group), and a butyl group (for example, 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), stable molded products 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 thereof 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 (peroxyesters) 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] As component (B), a thermal polymerization initiator having a one-hour half-life temperature of 30 to 130°C is preferred from the viewpoint of the heat resistance of the insert.

[0039] Specifically, among the above compounds, diacyl peroxides, peroxycarbonates, peroxyesters, and peroxyketals are preferred. The component (B) may be used alone 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 is a flame retardant containing a bromine atom (Br). By including component (C) as the flame retardant, even a small amount of component (C) can efficiently improve the flame retardancy of the thermosetting composition containing component (A). 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 comprises component (D), a flame retardant coagent. Component (D) is not particularly limited, and 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 Inc., "CN2283"), ethoxylated (3) trimethylolpropane triacrylate (manufactured by Arkema Inc., "SR454 TFN"), ethoxylated (6) trimethylolpropane triacrylate (manufactured by Arkema Inc., "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 blending standard is 100 parts by mass of the total of components (A) and (F).

[0052] (Other ingredients) The thermosetting composition of this embodiment may further contain components (other components) other than the above-mentioned components (A) to (F), such as various additives, within the scope of not impairing the effects of the present invention. 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, antifoaming agents, etc. Known additives can be used.

[0053] Examples of the antioxidant include phenol-based antioxidants, phosphorus-based antioxidants, sulfur-based antioxidants, vitamin-based antioxidants, lactone-based antioxidants, and amine-based antioxidants. The antioxidants may be used alone or in combination of two or more. 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 the components (A) and (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-based light stabilizer, but a hindered amine-based light stabilizer is preferred. The light stabilizers may be used alone or in combination of two or more. 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 bromine-based 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. The plasticizers can be used alone or in combination of two or more. When a plasticizer is contained, the content of the plasticizer is, for example, 1 to 50 parts by mass, preferably 10 to 35 parts by mass, and more preferably 15 to 30 parts by mass, per 100 parts by mass of the total of component (A) and component (B), from the viewpoint of not impairing the effects of the present invention.

[0057] Examples of the mold release agent include an internal mold release agent. Although there is no particular specification for the internal mold release agent, an aliphatic compound is preferable. 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. Examples of the release agent include magnesium stearate and zinc stearate. The release agent 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 relative to 100 parts by mass of the total of the components (A) and (B).

[0058] In one embodiment, for example, 40% by weight or more, 50% by weight or more, 60% by weight or more, 70% by weight or more, 80% by weight or more, 90% by weight or more, 95% by weight or more, 99% by weight or more, or substantially 100% by weight of the thermosetting composition of this aspect is Component (A), component (B) and component (C) Is it component (A), component (B), component (C) and component (D)? Components (A), (B), (C) and (E), Component (A), component (B), component (C), component (D) and component (E), The components are component (A), component (B), component (C), component (D), component (E) and component (F). In addition, in the case of "substantially 100% by mass", unavoidable impurities may be contained.

[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. Furthermore, mixing can be performed at room temperature, under cooling, or under heating, and under normal pressure, reduced pressure, or increased pressure.

[0060] 2. Manufacturing method of molded products A method for producing a molded article according to one aspect of the present invention includes subjecting the thermosetting composition according to one aspect of the present invention to molding. According to the method for producing a molded article of this embodiment, the low viscosity of the thermosetting composition allows for excellent processing accuracy (molding accuracy), and the molded article obtained has excellent flame retardancy and a high glass transition point (excellent heat resistance).

[0061] In one embodiment, the 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, a method for producing a molded product includes the steps of: supplying the above-mentioned thermosetting composition into a plunger (supplying step); filling the supplied thermosetting composition using the plunger into a molded product portion of a mold having a molded product 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, or 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 in the molded product portion (curing step). The method for producing a molded product may include a step (mold release step) of extruding the thermosetting resin from the molded product portion (cavity).

[0062] In one embodiment, from the viewpoint of preventing only the resin component of 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-mentioned 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 liquid transfer molding machine G-Line) 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 carried out, 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 can be used, and molding can be performed, for example, with 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 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 an embodiment of a filling device of a molding machine capable of carrying out an injection molding method in the method for producing a molded article of the present invention. The molding machine in Figure 1 is an injection molding machine having a plunger mechanism that extrudes a thermosetting composition into a mold, and is equipped with a filling device 10 having a plunger 11 shown in Figure 1 and a mold 20 having a cavity 21 shown in Figure 2(A), and although not shown, is also equipped with a pressure reducing device as degassing means connected to a fine hole for degassing cavity 21 in mold 20, a heating device as heating means connected to mold 20, and a cooling device. The molding material is the thermosetting composition of the present invention. In another embodiment, the molding machine may include an inert gas replacement device as means connected to the aperture for replacing 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, it is preferable to fill the cavity in the mold with the thermosetting composition 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 passage) between the plunger and the cavity to block the flow of the curing liquid and the exchange of heat in the step 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 Figure 2. 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, causing the thermosetting composition introduced into the introduction path 221 to remain in the cooling section 22B, thereby 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 is a device that heats the heating portion 22A and the movable mold 23. By these heating devices, the temperature inside the cavity (also called "cavity temperature") can be set to a predetermined temperature. In the method of the present invention, the temperature of the mold 232 that constitutes the cavity portion is preferably set to 40°C or higher and 150°C or lower. The cooling device is a device for cooling 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 a temperature of 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.

[0071] The feeding process is shown in FIG. 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 the filling device 10 shown in Figure 1 through an inlet (not shown). The injected thermosetting composition is pushed out into the check valve 12, and then a predetermined amount is measured out by the plunger 11. After measurement is complete or before injection, the check valve 12 moves forward, functioning as a check valve when the 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 that is connected to a pressure reducing device such as the pressure reducing pipe 240 in Figure 2 and allows the pressure inside the cavity to be reduced. The reason for this is that the vent is used to release air from the cavity during the process of injecting the thermosetting composition into the cavity and completely filling it, and reducing the pressure inside the cavity is used to create an airless 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. From the viewpoint of preventing poor curing, it is preferable that the gauge pressure in the cavity when injecting the thermosetting composition into the cavity is -90 kPa or less (vacuum pressure 10 kPa) and the amount of oxygen in the cavity is 0.2 × cavity volume / 22.4 mol or less, or that the gauge pressure in the cavity is -90 kPa or less (vacuum pressure 10 kPa) and the amount of oxygen in the cavity is 0.2 × cavity volume / 22.4 mol or less. A preferred method for reducing the amount of oxygen in the cavity to 0.2 x cavity volume / 22.4 mol or less is to degas the cavity in the mold using a pressure reducing device connected to a fine hole for degassing the cavity, and then to replace the cavity in the mold with an inert gas using an inert gas replacement device connected to a fine hole for replacing the cavity in the mold with an inert gas. Furthermore, the method for reducing the pressure inside the cavity is preferably sprueless. 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 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 parts 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 or higher and 150°C or lower, and particularly preferably 50°C or higher and 120°C or lower. When using an injection molding machine, when starting injection from the injection section into the cavity, the shut-off nozzle (or in some cases the valve gate) is opened, the plunger of the injection section is moved, and the thermosetting component is injected into the cavity.When using a transfer molding machine, the entire area from the inside of the plunger to the cavity is cured, so it is sufficient for the material to be able to flow into the cavity, and there is no need to block the exchange of heat.

[0074] The curing step is shown, for example, in FIG. 2(C). When the filling of the cavity 21 with the thermosetting composition is completed, the thermosetting composition simultaneously begins to harden. To improve the transferability of the molded product, it is preferable to harden the composition by applying a predetermined pressure. 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 the transferability is called a holding pressure. The curing process preferably involves dwelling (increasing the pressure applied to the thermosetting composition) after the start of thermal curing but before the completion of curing, and then closing the gate of the gate system 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. At this time, the entire flow path is preferably maintained at a temperature of 10°C or higher and 50°C or lower, and particularly preferably set to 30°C or lower.

[0075] The following describes the holding pressure applied by the plunger 11 and the timing of when the holding pressure starts. 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 when heat is applied and until it is completely hardened, and a late curing stage P3, when curing is complete. The viscosity of the thermosetting composition remains low and unchanged during the induction period P1, shows a significant viscosity change from low to high during the early curing stage P2, and gradually increases at a high viscosity during the late curing stage P3.

[0076] In the initial stage P2 of curing, the thermosetting composition not only changes in viscosity as it changes from liquid to solid, but also in volume, causing it to shrink. Therefore, if pressure is not applied to the thermosetting composition in actual molding, 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 from the gate portion. However, when pressure is applied to the thermosetting composition of this embodiment in a low-viscosity state, problems such as material leaking from the gap between the fixed mold 22 and the movable mold 23 and curing (burrs) can occur, or the thermosetting composition can seep into gaps around the ejector pin, causing the ejector pin to malfunction. On the other hand, applying pressure when the viscosity is high in the early curing stage P2 or in the late curing stage P3 cannot improve transferability because the thermosetting composition is too viscous to undergo compressive deformation. Therefore, to obtain a molded product with high transferability, it is preferable to time the start of dwell pressure (dwell pressure start time T) to coincide with the transition from the induction period P1 to the early curing stage P2 of the curing process.

[0077] Here, if the viscosity of the thermosetting composition in the cavity 21 can be detected, the time T at which pressure retention begins can be determined. Since the thermosetting composition in this embodiment begins to shrink at the same time as it thickens in the initial curing stage P2, it is preferable to detect the time when the shrinkage begins, thereby making it possible to appropriately determine the dwell start time T.

[0078] In the curing step, by maintaining 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 maintained for a certain period of time, the needle 223 is advanced to close the opening 222 as shown in FIG. 2(C), and the thermosetting composition is completely cured by heating for a certain period of time to prevent any uncured portions from occurring. 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. When filling is complete, the plunger 11 stops. Furthermore, as the curing of the thermosetting composition begins, the thermosetting composition simultaneously contracts, and the plunger 11, which had stopped after the filling step was completed, resumes advancing. The time required from the completion of the filling step until the plunger 11 resumes advancing 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 step and the thermosetting step) is preferably 0.2 to 3 minutes, and more preferably 0.2 to 2 minutes. A time of 0.2 minutes or less may result in incomplete curing, and a time of 3 minutes or more is undesirable from the perspective of mass productivity.

[0079] The demolding step is shown, for example, in FIG. 2(D). The cured product in the cavity can be removed by separating the movable mold 23 from the fixed mold 22. If mold releasability is poor, an ejector mechanism may be provided in the mold as appropriate.

[0080] 3.Cured product A cured product according to one embodiment of the present invention is produced using a thermosetting composition according to one embodiment of the present invention. The cured product according to this embodiment has excellent processing accuracy (molding accuracy) due to the low viscosity of the thermosetting composition, and the resulting molded article has excellent flame retardancy and a high glass transition point (excellent heat resistance). In one embodiment, the cured product is a molded article. In one embodiment, the cured product is an encapsulant. The cured product can be suitably used, for example, as a sealant for electronic circuit devices, a sealant for electronic circuit boards, and the like, although there are no particular limitations thereon. [Example]

[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. <Monomer> Component (A) (a compound represented by formula (A)) Tricyclodecane dimethanol dimethacrylate (manufactured by Shin-Nakamura Scientific Industrial Co., Ltd., "NK Ester DCP") Tricyclodecane dimethanol acrylate ("SR833 NS" manufactured by Arkema Co., Ltd.) 1-Isobornyl methacrylate (Kyoeisha Chemical Co., Ltd., "Light Ester IB-X") 1-Adamantyl methacrylate (Osaka Organic Chemical Industry Ltd., "ADMA")

[0083] Component (F) (Non-alicyclic acrylate) 2,3-Epoxypropyl methacrylate (NOF Corporation, "Blenmer GH") 2-Hydroxyethyl methacrylate (Kyoeisha Co., Ltd., "Light Ester HO-250(N)") Tetrahydrofurfuryl methacrylate (Kyoeisha Co., Ltd., "Light Ester THF (1000)") Lauryl acrylate (Kyoeisha Co., Ltd., "Light Acrylate LA") 1,9-Nonanediol diacrylate (Kyoeisha Co., Ltd., "Light Acrylate 1.9ND-A") 1,10-Decanediol diacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd., "NK Ester A-DOD-N") Difunctional ethoxylated bisphenol A-diacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd., "NK Ester BPE-80N") Polyester acrylate oligomer (Arkema Co., Ltd., "CN2283") Ethoxylated (3) trimethylolpropane triacrylate (Arkema Co., Ltd., "SR454 TFN") Ethoxylated (6) trimethylolpropane triacrylate (Arkema Co., Ltd., "SR499 NS")

[0084] Component (B) (thermal polymerization initiator) 1,1,3,3-Tetramethylbutylperoxyneodecanoate (NOF Corporation, "Perocta ND") Di-2-ethylhexyl peroxycarbonate (NOF Corporation, "Perloyl OPP") Dilauramiperoxide (NOF Corporation, "Perloyl L") 1,1-Di(t-amylperoxy)cyclohexane (Arkema Co., Ltd., "Luperox 531")

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

[0086] Component (D) (flame retardant auxiliary) Antimony trioxide (manufactured by Nihon 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 composition The raw materials were mixed by stirring to obtain the compositions shown in Tables 1 to 6. Specifically, a stirring device 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) Manufacturing of Molded Product 1 The thermosetting composition (1) above was subjected to LIM (Liquid Injection Molding) under the following conditions to obtain a cured product, Molded Product 1. The cavity size of the mold was 125 mm long, 13 mm wide, and 3 mm thick. Molding machine: Liquid thermosetting resin injection molding machine LA-40S (manufactured by Sodick Co., Ltd.) Weighed by the plunger of the molding machine: 1.1g Low temperature flow path temperature: 15℃ Flow path and heat blocking method: Uses shut-off nozzle Curing temperature: Temperatures shown in Tables 1 to 6 Filling pressure: 10MPa or less Pressure retention time: 15 seconds Holding pressure: 15MPa Curing time: Times shown in Tables 1 to 6

[0089] (3) Manufacture of Molded Product 2 The thermosetting composition (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] <Testing and evaluation methods> (1) Material viscosity Measurement was carried out 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 Flammability Test Chamber, manufactured by Atlas). If the molded article was judged to be V-0 grade, it was rated as "A", and if not, it was rated as "B". (3) Glass transition temperature (Tg) The viscoelasticity of the cured product of molded article 2 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 filler (silica) content.

[0092] [Table 1]

[0093] [Table 2]

[0094] [Table 3]

[0095] [Table 4]

[0096] [Table 5]

[0097] [Table 6]

[0098] Tables 1 to 3 show that the Examples can achieve 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.

Claims

1. (A) A compound represented by the following formula (A): (B) a thermal polymerization initiator, and (C) Brominated flame retardants A thermosetting composition comprising: 【Transformation 5】 (In formula (A), R １ are each independently a hydrogen atom or a methyl group. R 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 article 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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