WO2025028480A1 - Thermosetting composition, method for producing molded article using same, and cured product - Google Patents

Abstract

Provided is a thermosetting composition which contains components (A), (B) and (C) and also contains one or more components selected from the group consisting of components (D) to (F). The content of components having a melting point of -5°C or higher among components (A) and (D) to (F) is 40 mass% or more relative to the total amount of components (A) and (D) to (F).　(A) A substituted or unsubstituted monofunctional or polyfunctional (meth)acrylate compound which has a group having an alicyclic hydrocarbon group with 6 or more ring-forming carbon atoms as an ester substituent group and which has a viscosity at 25°C of 1 to 300 mPa·s. (B) Spherical silica. (C) A pigment or dye. (D) (Meth)acrylic acid or a monofunctional (meth)acrylate compound having a polar group as an ester substituent group. (E) A monofunctional (meth)acrylate compound having a group other than the ester substituent group in component (A) and the ester substituent group in component (D) as an ester substituent group. (F) A polyfunctional (meth)acrylate compound having a group other than the ester substituent group in component (A) as an ester substituent group

Description

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

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

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

As a material used for a reflector for an optical semiconductor, Patent Document 1 discloses a thermosetting composition containing a (meth)acrylate compound and a white pigment such as titanium oxide and having a predetermined shear viscosity.
The thermosetting composition described in Patent Document 1 has high reflectance in the visible light region, excellent whiteness, excellent heat resistance and light resistance, and also has excellent adhesion to surrounding members (particularly lead frames).
According to Patent Document 1, by using the above-mentioned thermosetting composition, it is possible to suppress the generation of burrs when forming a reflector, and it is said that the composition has excellent continuous moldability.

JP 2016-8230 A

It has been found that there is room for further improvement in the storage stability of conventional reflective materials, including those described in Patent Document 1.

The object of the present invention is to provide a thermosetting composition having excellent storage stability, a method for producing a molded article using the same, and a cured product.

（式（Ｇ１）中、
　Ｒ_４０１は、水素原子又はメチル基である。
　式（Ｇ２）中、
　Ｒ_４０２は、水素原子又はメチル基である。
　Ｒ_４０３は、炭素数２～１８のアルキル基、－Ｒ_４１１ＯＲ_４１２、又は－Ｒ_４１３ＳＲ_４１４である。
　Ｒ_４１１及びＲ_４１３は、それぞれ独立に、炭素数１～３０のアルキレン基である。
　Ｒ_４１２及びＲ_４１４は、それぞれ独立に、炭素数１～３０のアルキル基である。）
８．さらに、成分（Ｈ）板状フィラーを含む１～７のいずれかに記載の熱硬化性組成物。
９．前記成分（Ａ）～（Ｈ）の合計１００質量％を基準として、前記成分（Ｂ）、（Ｃ）及び（Ｈ）の合計の含有量が８４質量％以下である８に記載の熱硬化性組成物。
１０．前記成分（Ａ）及び（Ｄ）～（Ｆ）の混合物についての２５℃で１０ｓ^－１のせん断速度での粘度が１～５００ｍＰａ・ｓである１～９のいずれかに記載の熱硬化性組成物。
１１．２５℃で１０ｓ^－１のせん断速度での粘度が１～２００Ｐａ・ｓである１～１０のいずれかに記載の熱硬化性組成物。
１２．１～１１のいずれかに記載の熱硬化性組成物を、プランジャー内に供給する工程、
　供給された前記熱硬化性組成物を、前記プランジャーにより、金型の成形品部に充填する工程、
　充填された前記熱硬化性組成物を、前記成形品部内で熱硬化する工程、及び
　熱硬化した樹脂を押し出す工程、
を含む成形品の製造方法。
１３．前記成形品部を構成する金型部分の温度が１００～１８０℃である１２に記載の成形品の製造方法。
１４．前記プランジャー及び前記成形品部の間に５０℃以下に温度制御された流動路を有し、前記流動路を介して、前記充填を行う１２又は１３に記載の成形品の製造方法。
１５．前記流動路に、前記熱硬化性組成物の流動及び熱の授受を遮断するゲートシステムを有する１４に記載の成形品の製造方法。
１６．前記充填を、前記ゲートシステムのゲートを開くことで行い、
　前記熱硬化において、保圧を行い、前記保圧後、前記ゲートシステムのゲートを閉じて熱硬化を完了する１５に記載の成形品の製造方法。
１７．前記充填工程と前記熱硬化工程を０．２～３分間で行う１２～１６のいずれかに記載の成形品の製造方法。
１８．１～１１のいずれかに記載の熱硬化性組成物を用いて作製した硬化物。
１９．成形品である１８に記載の硬化物。 According to the present invention, the following thermosetting composition and the like are provided.
1. The following components (A), (B) and (C):
One or more selected from the group consisting of the following components (D) to (F);
A thermosetting composition comprising:
A thermosetting composition, comprising the following components (A) and (D) to (F), each of which has a melting point of -5°C or higher, in an amount of 40 mass% or more based on the total amount of the following components (A) and (D) to (F):
(A) a monofunctional or polyfunctional (meth)acrylate compound having, as an ester substituent, a substituted or unsubstituted group having an alicyclic hydrocarbon group having 6 or more ring carbon atoms, and having a viscosity of 1 to 300 mPa·s at 25°C; (B) spherical silica; (C) a pigment or dye; (D) a monofunctional (meth)acrylate compound having, as an ester substituent, (meth)acrylic acid or a group having a polar group; (E) a monofunctional (meth)acrylate compound having, as an ester substituent, a group other than the ester substituent of the component (A) and the ester substituent of the component (D); (F) a polyfunctional (meth)acrylate compound having, as an ester substituent, a group other than the ester substituent of the component (A).2. 2. The thermosetting composition according to 1, wherein the substituted or unsubstituted alicyclic hydrocarbon group having 6 or more ring carbon atoms in the component (A) is one or more groups selected from the group consisting of a substituted or unsubstituted adamantyl group, a substituted or unsubstituted norbornyl group, a substituted or unsubstituted isobornyl group, a substituted or unsubstituted tricyclodecanyl group, and a substituted or unsubstituted dicyclopentanyl group.
3. The thermosetting composition according to 1 or 2, wherein the component (B) is spherical silica that has been surface-treated with an acrylsilane or a methacrylsilane.
4. The thermosetting composition according to any one of 1 to 3, wherein the average particle size (D50) of the component (B) is 0.1 to 100 μm.
5. The thermosetting composition according to any one of 1 to 4, wherein the component (C) is a white pigment.
6. The thermosetting composition according to any one of 1 to 4, wherein the component (C) is a black pigment or a black dye.
7. The thermosetting composition according to any one of 1 to 6, further comprising the following component (G):
(G) A block copolymer comprising at least one block of a repeating unit represented by the following formula (G1) and at least one block of a repeating unit represented by the following formula (G2):

(In formula (G1),
R ₄₀₁ is a hydrogen atom or a methyl group.
In formula (G2),
R ₄₀₂ is a hydrogen atom or a methyl group.
R ₄₀₃ is an alkyl group having 2 to 18 carbon atoms, —R ₄₁₁ OR ₄₁₂ , or —R ₄₁₃ SR ₄₁₄ .
R ₄₁₁ and R ₄₁₃ each independently represent an alkylene group having 1 to 30 carbon atoms.
R ₄₁₂ and R ₄₁₄ each independently represent an alkyl group having 1 to 30 carbon atoms.
8. The thermosetting composition according to any one of 1 to 7, further comprising a flake-like filler as component (H).
9. The thermosetting composition according to 8, wherein the total content of the components (B), (C) and (H) is 84 mass% or less, based on 100 mass% in total of the components (A) to (H).
10. The thermosetting composition according to any one of 1 to 9, wherein the mixture of components (A) and (D) to (F) has a viscosity of 1 to 500 mPa·s at 25° C. and a shear rate of 10 ^s −1.
11. The thermosetting composition according to any one of 1 to 10, having a viscosity of 1 to 200 Pa·s at 25° C. and a shear rate of 10 s ⁻¹ .
12. A step of supplying the thermosetting composition according to any one of 1 to 11 into a plunger;
A step of filling the supplied thermosetting composition into a molded product portion of a mold by the plunger;
a step of thermally curing the filled thermosetting composition within the molded product portion; and a step of extruding the thermoset resin.
A method for producing a molded article comprising the steps of:
13. The method for producing a molded product according to 12, wherein the temperature of the mold part constituting the molded product portion is 100 to 180°C.
14. The method for producing a molded product according to 12 or 13, further comprising providing a flow path between the plunger and the molded product portion, the temperature of which is controlled to 50° C. or less, and the filling is carried out via the flow path.
15. The method for producing a molded article according to 14, further comprising a gate system in the flow path for blocking the flow of the thermosetting composition and the transfer of heat.
16. The filling is performed by opening a gate of the gate system;
16. The method for producing a molded product according to claim 15, further comprising the steps of: performing pressure dwelling during the thermal curing; and closing a gate of the gate system after the pressure dwelling to complete the thermal curing.
17. The method for producing a molded product according to any one of 12 to 16, wherein the filling step and the heat curing step are carried out for 0.2 to 3 minutes.
18. A cured product produced using the thermosetting composition according to any one of 1 to 11.
19. The cured product according to 18, which is a molded article.

The present invention provides a thermosetting composition with excellent storage stability, a method for producing a molded product using the same, and a cured product.

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

In this specification, the "carbon number XX to YY" in the expression "substituted or unsubstituted ZZ group having carbon numbers 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 greater than "XX", and "XX" and "YY" each represent an integer of 1 or more.

In the case of "substituted or unsubstituted," "unsubstituted" means that it is not substituted with a substituent and has a hydrogen atom bonded to it.

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, and acrylic and methacrylic are collectively referred to as (meth)acrylic.
Moreover, an acryloyl group and a methacryloyl group are collectively referred to as a (meth)acryloyl group.

In this specification, "x to y" represents a numerical range of "greater than or equal to x, and less than or equal to y." When there are multiple lower limit values, such as "greater than or equal to x," or multiple upper limit values, such as "less than or equal to y," for a single technical item, any combination of upper and lower limit values may be selected at will.

1. Thermosetting composition The thermosetting composition according to one embodiment of the present invention comprises:
The following components (A), (B) and (C):
One or more selected from the group consisting of the following components (D) to (F);
A thermosetting composition comprising:
The composition is characterized in that, among the following components (A) and (D) to (F), the content of components having a melting point of -5°C or higher is 40 mass% or more based on the total content of the following components (A) and (D) to (F).
(A) a monofunctional or polyfunctional (meth)acrylate compound having, as an ester substituent, a substituted or unsubstituted group having an alicyclic hydrocarbon group having 6 or more ring carbon atoms, and having a viscosity of 1 to 300 mPa·s at 25°C; (B) spherical silica; (C) a pigment or dye; (D) a monofunctional (meth)acrylate compound having, as an ester substituent, a group having (meth)acrylic acid or a polar group; (E) a monofunctional (meth)acrylate compound having, as an ester substituent, a group other than the ester substituent of the component (A) and the ester substituent of the component (D); (F) a polyfunctional (meth)acrylate compound having, as an ester substituent, a group other than the ester substituent of the component (A).

The thermosetting composition of this embodiment has the above-mentioned configuration, and therefore has excellent storage stability and moldability.

（式（Ｇ１）中、
　Ｒ_４０１は、水素原子又はメチル基である。
　式（Ｇ２）中、
　Ｒ_４０２は、水素原子又はメチル基である。
　Ｒ_４０３は、炭素数２～１８のアルキル基、－Ｒ_４１１ＯＲ_４１２、又は－Ｒ_４１３ＳＲ_４１４である。
　Ｒ_４１１及びＲ_４１３は、それぞれ独立に、炭素数１～３０のアルキレン基である。
　Ｒ_４１２及びＲ_４１４は、それぞれ独立に、炭素数１～３０のアルキル基である。）
　（Ｈ）板状フィラー The thermosetting composition of this embodiment may further contain the following components (G) and/or (H).
(G) A block copolymer comprising at least one block of a repeating unit represented by the following formula (G1) and at least one block of a repeating unit represented by the following formula (G2):

(In formula (G1),
R ₄₀₁ is a hydrogen atom or a methyl group.
In formula (G2),
R ₄₀₂ is a hydrogen atom or a methyl group.
R ₄₀₃ is an alkyl group having 2 to 18 carbon atoms, —R ₄₁₁ OR ₄₁₂ , or —R ₄₁₃ SR ₄₁₄ .
R ₄₁₁ and R ₄₁₃ each independently represent an alkylene group having 1 to 30 carbon atoms.
R ₄₁₂ and R ₄₁₄ each independently represent an alkyl group having 1 to 30 carbon atoms.
(H) Plate-like filler

Note that a monofunctional (meth)acrylate compound refers to a compound having one (meth)acryloyl group, and a polyfunctional (meth)acrylate compound refers to a compound having two or more (meth)acryloyl groups.

（式（ａ）において、Ｒ^１１は、水素原子又はメチル基を示す。） The ester substituent is a group represented by R ¹² in the following formula (a).

(In formula (a), R ¹¹ represents a hydrogen atom or a methyl group.)

The thermosetting composition of the present embodiment has the above composition, and therefore does not require the strict temperature control that has been conventionally performed to store a thermosetting composition in a solidified state (for example, temperature control in which the composition is cooled to an extremely low temperature range, such as −20° C. or lower, and the like). This makes it easier to store the thermosetting composition.
The thermosetting composition of this embodiment can maintain a state in which the resin component such as the (meth)acrylate compound and the inorganic component such as the white pigment are uniformly mixed and solidified by maintaining the thermosetting composition in a cooled state, for example, to a temperature range of -10°C or thereabouts, which is higher than conventional temperatures. Therefore, a stable storage state can be maintained in which the solid-liquid separation phenomenon in which the resin component and the inorganic component are separated in the composition is suppressed. Therefore, the thermosetting composition according to this embodiment has excellent storage stability.

Furthermore, according to the thermosetting composition of the present embodiment, the strict temperature control that has been conventionally performed to store a thermosetting composition in a solidified state (for example, temperature control in which the composition is cooled to an extremely low temperature range of −20° C. or lower and maintained at that temperature) is no longer necessary, and therefore the cost required for storing the thermosetting composition can be reduced.
For example, the introduction of special cooling equipment and strict temperature control that have been required to maintain the temperature at the extremely low temperatures mentioned above will no longer be necessary, which will result in cost savings.

Components contained in components (A), (D) to (F) that have a melting point of -5°C or higher (hereinafter referred to as component (α)) will be described in detail in the explanation of each of components (A) and (D) to (F). The melting point of each component can be determined by the method described in the examples.

The content of component (α) which is contained in components (A), (D) to (F) and has a melting point of −5° C. or higher (hereinafter referred to as proportion I) may be, for example, 40 mass% or more, 45 mass% or more, or 50 mass% or more, and may be 90 mass% or less, 85 mass% or less, or 80 mass% or less, based on 100 mass% in total of components (A), (D) to (F).
The higher the content of component (α), the higher the temperature at which the thermosetting composition begins to solidify when cooled.
The smaller the content of component (α), the better the light reflecting properties and filling properties can be.

In one embodiment, the thermosetting composition of this embodiment preferably satisfies the following ratio II.
Ratio II: the total content of the components (B), (C) and (H) is 84 mass% or less, based on 100 mass% in total of the components (A) to (H).

By satisfying the above ratio II, the cured product obtained by using the thermosetting composition of this embodiment can obtain high flexibility. Therefore, the occurrence of cracks, chips, etc. due to slight impact, which occurred in the cured product with higher hardness obtained by using the conventional thermosetting composition, is suppressed. Therefore, the occurrence rate of defective products can be reduced in the molded product (e.g., LED reflector) made of the cured product obtained by using the thermosetting composition of this embodiment, and high production stability can be realized.
In addition, the cured product obtained using the thermosetting composition of this embodiment is unlikely to crack or chip even upon slight impact, and therefore has excellent handleability. It is also possible to improve production stability in the manufacture of optical semiconductors and the like using molded articles made of the cured product.

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

Based on 100% by mass of the total of the components (A) to (H), the total content of the components (B), (C) and (H) (ratio II) may be, for example, 84% by mass or less, 83% by mass or less, or 81% by mass or less, or 50% by mass or more, 58% by mass or more, or 63% by mass or more. The upper and lower limits may be combined in any desired manner.
The lower the total content of components (B), (C) and (H), the more the hardness of the cured product is prevented from becoming excessively high, and the more excellent flexibility is obtained.
The higher the total content of components (B), (C) and (H), the greater the hardness and strength of the cured product can be ensured and the occurrence of burrs during molding can be suppressed.

The components of this thermosetting composition are described below.

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

From the viewpoint of enhancing the filling properties of components (B) and (C), component (A) has a viscosity at 25°C at a shear rate of 10 ^s measured at a constant shear rate using a rotational viscometer (JIS K7117-2:1999) of 1 to 300 mPa·s, more preferably 2 to 200 mPa·s, and even more preferably 3 to 100 mPa·s.
The viscosity is measured using a viscoelasticity measuring device.

The substituted or unsubstituted alicyclic hydrocarbon group of component (A) having 6 or more ring carbon atoms includes a substituted or unsubstituted adamantyl group, a substituted or unsubstituted norbornyl group, a substituted or unsubstituted isobornyl group, a substituted or unsubstituted dicyclopentanyl group, and a cyclohexyl group, and the like, with a substituted or unsubstituted adamantyl group, a substituted or unsubstituted norbornyl group, a substituted or unsubstituted isobornyl group, and a substituted or unsubstituted dicyclopentanyl group being preferred.

（式（Ｉ）、（II）、（III）及び（IV）において、Ｒ^１は、それぞれ独立に、水素原子又はメチル基を示す。
　Ｘは、それぞれ独立に、単結合、炭素数１～４（好ましくは１又は２）のアルキレン基、又は炭素数１～４（好ましくは１又は２）のオキシアルキレン基を示す（好ましくは単結合）。
　Ｕは、それぞれ独立に水素原子、炭素数１～４（好ましくは１又は２）のアルキル基、ハロゲン原子、水酸基、又は＝Ｏ基を示す。ｋは１～１５の整数を示す。ｌは１～８の整数を示す。ｍは１～１１の整数を示す。ｎは１～１５の整数を示す。
　Ｕが２以上存在する場合、２以上のＵは同一でもよく、異なっていてもよい。） As the component (A), compounds represented by the following formulae (I) to (IV) are preferred.

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

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

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 formulae (I) to (IV).
Examples of the alkyl group having 1 to 4 carbon atoms for U include a methyl group, an ethyl group, a propyl group (eg, n-propyl group, isopropyl group), and a butyl group (eg, n-butyl group, isobutyl group).
Examples of the halogen atom represented by U include a fluorine atom, a bromine atom, and an iodine atom.

In terms of heat resistance, X is preferably a single bond.

Component (A) is more preferably adamantyl methacrylate, cyclohexyl methacrylate, 1-norbornyl methacrylate, 1-isobornyl methacrylate, 1-isobornyl acrylate, or 1-dicyclopentanyl methacrylate, and even more preferably 1-adamantyl methacrylate, 1-norbornyl methacrylate, or 1-isobornyl methacrylate.

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

Component (A) may be used alone or in combination of two or more types.

The content of component (A) based on 100% by mass of the total of components (A) to (F) may be 1 to 50% by mass, 2 to 40% by mass, 2.5 to 30% by mass, or 2.6 to 20% by mass.

Based on 100% by mass of the total of components (A) to (G), the content of component (A) may be 0.5 to 10% by mass, 1.5 to 5.0% by mass, 1.8 to 4.0% by mass, or 2.0 to 3.9% by mass.
When the content of component (A) is within the above range, the resulting cured product has excellent heat resistance and light resistance, and also has appropriate flexibility.
Specifically, the higher the content of component (A), the higher the heat resistance and light resistance of the cured product, while the lower the content of component (A), the more the hardness of the cured product obtained can be prevented from becoming excessively high, and the more appropriate the flexibility can be obtained.

The content of component (A) based on the total of components (A) to (H) being 100% by mass may be 2 to 10% by mass, 2 to 8% by mass, 2.2 to 7.0% by mass, or 2.2 to 6.0% by mass.

<Component (B)>
Component (B) is spherical silica (SiO ₂ ).
By including component (B), the refractive index of the obtained cured product can be increased, and the flowability of the thermosetting composition can be maintained, thereby improving the filling property during molding.
In addition, the content of component (C) can be increased, and the material strength, reflectance, heat resistance, and light resistance can be further improved.

The average particle size (D50) of component (B) is, from the viewpoints of improving filling properties, suppressing clogging of molding flow paths, and ensuring flexibility of the cured product, for example, 0.1 to 100 μm, preferably 0.5 to 70 μm, more preferably 1 to 50 μm, and particularly preferably 1 to 15 μm.
The average particle size (D50) of component (B) is measured using a laser diffraction particle size distribution measuring device.
The average particle size (D50) refers to the median diameter of a cumulative distribution, and means the diameter at which, when divided into two, the larger side and the smaller side are equal in amount.

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

Examples of component (B) include CRS1085-SF630 (manufactured by Tatsumori Co., Ltd.), CRS1035-LER4: spherical silica with an average particle size (D50) of 2 μm (manufactured by Tatsumori Co., Ltd.), S430-5PHM (manufactured by Nippon Steel Chemical & Material Co., Ltd.), SP40HM (manufactured by Nippon Steel Chemical & Material Co., Ltd.), and FB-304HM (manufactured by Denka Co., Ltd.).

Component (B) may be used alone or in combination of two or more types.

The content of component (B) based on 100% by mass of the total of components (A) to (F) may be 10 to 90% by mass, 20 to 80% by mass, 30 to 70% by mass, or 35 to 60% by mass.
Furthermore, the content of component (B) based on 100% by mass of the total of components (A) to (H) may be 10 to 80% by mass, 20 to 70% by mass, 30 to 60% by mass, or 31 to 50% by mass.

By the content of component (B) being within the above range, the flowability and storage stability at room temperature of the thermosetting composition can be improved. In addition, the strength of the cured product can be secured and burrs can be further suppressed. In addition, the hardness of the cured product can be prevented from becoming excessively high, and appropriate flexibility can be obtained.
When two or more types of component (B) are combined, the content of component (B) is the total content of the two or more types.

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

The crystal type of titanium dioxide may be either rutile or anatase. From the standpoint of light resistance, the rutile type is preferred.

From the viewpoint of dispersibility, the average primary particle size of the white pigment is preferably from 0.01 to 20 μm, more preferably from 0.05 to 10 μm, and even more preferably from 0.1 to 1 μm.
The average primary particle size of the white pigment can be measured using a scanning electron microscope.
The primary average particle size refers to the average particle size of the primary particles. Primary particles are tiny solids, and when they gather together, they tend to stick together due to static electricity and other forces. For this reason, several tiny solids may stick together to form secondary particles (aggregated particles or aggregates).
In a scanning electron microscope, primary particles appear as millet-like particles among secondary particles, being the smallest constituent unit of the secondary particles, and their maximum length can be measured.

The white pigment may be a hollow particle from the viewpoint of improving the refractive index. The gas inside the hollow particle is usually air, but it may be an inert gas such as nitrogen or argon, or it may be a vacuum.

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

The white pigment may be used alone or in combination of two or more types.

Specific examples of black pigments include metal oxide pigments or composite metal oxide pigments containing at least one metal selected from chromium (Cr), cobalt (Co), nickel (Ni), iron (Fe), manganese (Mn), copper (Cu), etc.; carbon pigments such as activated carbon and carbon black; mixed organic pigments that are black by mixing various organic pigments such as aniline black; and titanium-based black pigments represented by TiO _x (titanium oxide) or TiO _x N _y (titanium oxynitride).
Among these, from the viewpoint of stably obtaining a low reflectance in the cured product, insulating carbon black, titanium-based black pigments represented by TiO _x (titanium oxide), TiN _y (titanium nitride) or TiO _x N _y (titanium oxynitride), titanium black and titanium oxide can be preferably used. Here, x and y are integers of 0 or more. In this specification, those in which x is 3 or less are called low-order titanium oxides. In addition, black plate-like fillers such as mica can be used.

Specific examples of black dyes include nigrosine dyes and azo dyes.

Component (C) may be a black dye, but from the standpoint of light resistance, component (C) is preferably a black pigment.

The black pigment and/or black dye may be used alone or in combination of two or more types.

The crystalline form of titanium oxide may be either rutile or anatase, but there is concern that anatase has a photocatalytic function and may cause deterioration of resin. For this reason, from the standpoint of light resistance, rutile titanium oxide is preferred.

From the viewpoint of dispersibility, the average primary particle size of the black pigment is preferably from 0.01 to 20 μm, more preferably from 0.01 to 10 μm, and even more preferably from 0.02 to 1 μm.
The average primary particle size of component (C) can be measured by a scanning electron microscope according to the method described in the Examples.
The primary average particle size refers to the average particle size of the primary particles. Primary particles are tiny solids, and when they gather together, they tend to stick together due to static electricity and other forces. For this reason, several tiny solids may stick together to form secondary particles (aggregated particles or aggregates).
In a scanning electron microscope, primary particles appear as millet-like particles among secondary particles, being the smallest constituent unit of the secondary particles, and their maximum length can be measured.

The black pigment may be a hollow particle. When the black pigment is a hollow particle, visible light that passes through the outer shell of the hollow particle is absorbed in the hollow space. To increase the absorption rate in the hollow space, it is preferable that there is a large difference in refractive index between the part that constitutes the hollow particle and the gas present inside the hollow particle. The gas present inside the hollow particle is usually air, but it may be an inert gas such as nitrogen or argon, or it may be a vacuum.

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

The content of component (C) based on 100 mass% in total of components (A) to (F) may be 0.1 to 50 mass%, may be 0.1 to 40 mass%, may be 0.1 to 30 mass%, may be 0.1 to 20 mass%, or may be 5 to 20 mass%.
Furthermore, the content of component (C) based on the total of components (A) to (H) being 100% by mass, may be 0.01 to 40% by mass, may be 0.1 to 30% by mass, may be 0.1 to 20% by mass, or may be 0.1 to 15% by mass.

By having the content of component (C) within the above range, the flowability of the thermosetting composition can be improved. In addition, the whiteness of the cured product can be ensured. In addition, the hardness of the cured product can be prevented from becoming excessively high, and appropriate flexibility can be obtained.

<Component (D)>
Component (D) is a monofunctional acrylate compound or monofunctional methacrylate compound having acrylic acid, methacrylic acid, or a group having a polar group (other than the ester substituent of component (A)) as an ester substituent.
Since component (D) has a polar group, it can improve the adhesion and wettability of the resulting cured product.

Polar groups include hydroxyl groups, epoxy groups, glycidyl groups, glycidyl ether groups, tetrahydrofurfuryl groups, isocyanate groups, carboxyl groups, alkoxysilyl groups, phosphate ester groups, lactone groups, oxetane groups, tetrahydropyranyl groups, and amino groups. Among these, glycidyl ether groups, phosphate ester groups, carboxyl groups, and lactone groups are preferred because they provide higher adhesion and wettability than glycidyl groups.

Specific examples of monofunctional (meth)acrylate compounds having a group having a polar group as an ester substituent include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate (e.g., trade name: 4-HBA, manufactured by Nippon Kasei Chemical Industry Co., Ltd.), cyclohexanedimethanol mono(meth)acrylate (e.g., trade name: CHMMA, manufactured by Nippon Kasei Chemical Industry Co., Ltd.), glycidyl (meth)acrylate, 4-hydroxybutyl acrylate glycidyl ether (e.g., trade name: 4-HBAGE, manufactured by Nippon Kasei Chemical Industry Co., Ltd.), tetrahydrofurfuryl (meth)acrylate, 2-isocyanatoethyl (meth)acrylate, 2-(meth)acryloyloxyethyl succinate, 2-(meth)acryloyloxyethyl hexahydroxyethyl ether, and 2-(meth)acryloyloxyethyl hexahydroxyethyl ether. Examples of suitable acrylates include dorophthalic acid, 3-(meth)acryloxypropyltrimethoxysilane, 3-(meth)acryloxypropylmethyldimethoxysilane, 3-(meth)acryloxypropyltriethoxysilane, 3-(meth)acryloxypropylmethyldiethoxysilane, 2-(meth)acryloyloxyethyl phosphate, bis(2-(meth)acryloyloxyethyl)phosphate, KAYAMER PM-2 (trade name, manufactured by Nippon Kayaku Co., Ltd.), KAYAMER PM-21 (trade name, manufactured by Nippon Kayaku Co., Ltd.), γ-butyrolactone (meth)acrylate, 3-methyl-3-oxetanyl (meth)acrylic acid, 3-ethyl-3-oxetanyl (meth)acrylic acid, tetrahydrofurfuryl (meth)acrylate, dimethylaminoethyl (meth)acrylate, and diethylaminoethyl (meth)acrylate.

Component (D) may be used alone or in combination of two or more types.

The content of component (D) based on 100% by mass of the total of components (A) to (F) may be 0 to 40% by mass, 1 to 20% by mass, 1 to 15% by mass, or 3 to 15% by mass.
Furthermore, the content of component (D) based on 100% by mass of the total of components (A) to (H) may be 1 to 40% by mass, 1 to 30% by mass, 2 to 20% by mass, or 3 to 15% by mass.
By ensuring that the content of component (E) is within the above range, a cured product having excellent adhesion and appropriate flexibility can be obtained.

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

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

In order to prevent discoloration to yellow or the like during thermal curing, it is preferable that component (E) does not contain an aliphatic urethane structure (e.g., -NH-C(=O)-O-).

Components (α) that are included in component (E) and have a melting point of -5°C or higher include stearyl methacrylate and lauryl acrylate.

Component (E) may be used alone or in combination of two or more types.

Furthermore, the content of component (E) based on the total of components (A) to (F) being 100% by mass, may be 0 to 30% by mass, 1 to 20% by mass, or 3 to 13% by mass.
Furthermore, the content of component (E) based on the total of components (A) to (H) being 100% by mass, may be 0 to 30% by mass, 0 to 20% by mass, 0 to 10% by mass, or 1 to 10% by mass.
By ensuring that the content of component (F) is within the above range, it is possible to obtain a cured product that has excellent toughness and adhesion, as well as appropriate flexibility.

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

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

From the viewpoint of heat resistance, it is preferable that component (F) does not contain an aliphatic urethane structure (e.g., -NH-C(=O)-O-).

Components (α) that are included in component (F) and have a melting point of -5°C or higher include 1,10-decanediol di(meth)acrylate and 1,9-nonanediol di(meth)acrylate.

Component (F) may be used alone or in combination of two or more types.

The content of component (F) based on 100 mass% in total of components (A) to (F) may be 0 to 60 mass%, 0 to 50 mass%, 5 to 50 mass%, or 8 to 45 mass%.
Furthermore, the content of component (F) based on 100% by mass of the total of components (A) to (H) may be 0 to 70% by mass, 0 to 50% by mass, 1 to 45% by mass, or 5 to 45% by mass.
By ensuring that the content of component (F) is within the above range, it is possible to obtain a cured product that has excellent mechanical strength, excellent resistance to thermal distortion, and appropriate flexibility.
Furthermore, by ensuring that the content of component (F) is within the above range, the curing rate of the thermosetting composition can be adjusted within an appropriate range, allowing the curing reaction to proceed smoothly.

Among the components (A), (D) to (F) and component (α) having a melting point of -5°C or higher, the ratio of component (E) to component (F) is preferably 0.5 to 10, more preferably 0.5 to 5, in mass ratio ([component (F)]/[component (E)]).

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

(In formula (G1),
R ₄₀₁ is a hydrogen atom or a methyl group.
In formula (G2),
R ₄₀₂ is a hydrogen atom or a methyl group.
R ₄₀₃ is an alkyl group having 2 to 18 carbon atoms, —R ₄₁₁ OR ₄₁₂ , or —R ₄₁₃ SR ₄₁₄ .
R ₄₁₁ and R ₄₁₃ each independently represent an alkylene group having 1 to 30 carbon atoms.
R ₄₁₂ and R ₄₁₄ each independently represent an alkyl group having 1 to 30 carbon atoms.

Component (G) is a component generally called an elastomer, which is a polymer having viscoelasticity, small intermolecular interactions, a small Young's modulus, and a large fracture strain.
By adding component (G), the effect of improving toughness can be obtained.

The block polymer containing at least one block of repeating units represented by formula (G1) and at least one block of repeating units represented by formula (G2) may contain any number of blocks, and may be a diblock copolymer, triblock copolymer, or tetrablock copolymer. It may also be a radially branched star polymer containing three or more polymer chains made of the block copolymer. The block copolymer is preferably a diblock copolymer or triblock copolymer, and more preferably a triblock copolymer represented by the following general formula (G3).

（式（Ｇ３）中、Ｒ_４０１～Ｒ_４０３は、前記式（Ｇ１）及び（Ｇ２）で定義した通りである。ｌ、ｍ、及びｎは、各ブロックの平均構成単位数である。）

(In formula (G3), R ₄₀₁ to R ₄₀₃ are as defined in formulas (G1) and (G2) above. l, m, and n are the average numbers of constituent units in each block.)

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

From the viewpoint of suppressing warpage of the molded article and improving the reflectivity, durability, toughness, and chemical resistance, it is preferable that the ratio of the repeating units represented by formula (G1) to the total of the repeating units represented by formula (G1) and the structural units represented by formula (G2) in component (G) is 10 mol % or more.

In order to obtain a suitable degree of elasticity, the ratio of the structural unit represented by formula (G2) to the total of the structural unit represented by formula (G1) and the structural unit represented by formula (G2) in component (G) is preferably 30 to 95 mol %, and more preferably 40 to 90 mol %.

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

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

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

Component (G) may be used alone or in combination of two or more types.

The content of component (G) based on the total of components (A) to (H) being 100% by mass, may be 0 to 40% by mass, 0 to 30% by mass, 1 to 20% by mass, or 1 to 15% by mass.
Furthermore, the content of component (G) based on 100 parts by mass in total of components (A) to (F) may be 0 to 40 parts by mass, 0 to 30 parts by mass, 1 to 20 parts by mass, or 1 to 15 parts by mass.

<Component (H)>
Component (H) is a flake-like filler.
By containing component (H), the viscosity of the thermosetting composition can be adjusted, and the hardness of the obtained cured product can be adjusted and burrs can be suppressed. In addition, by containing component (H), the warping of the obtained cured product can be suppressed. In addition, by containing component (H), the solid-liquid separation rate during storage at room temperature can be reduced.

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

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

Component (H) may be used alone or in combination of two or more types.

The content of component (H) based on 100% by mass of the total of components (A) to (H) may be 0 to 30% by mass, 0 to 20% by mass, 1 to 18% by mass, or 1 to 15% by mass.
Furthermore, the content of component (H) based on 100 parts by mass in total of components (A) to (F) may be 0 to 30 parts by mass, 0 to 20 parts by mass, 1 to 20 parts by mass, or 1 to 17 parts by mass.
When two or more types of component (H) are combined, the content of component (D) is the total content of the two or more types.

By keeping the content of component (H) within the above range, warping is suppressed and a cured product with a good appearance is obtained. In addition, the hardness of the cured product is prevented from becoming excessively high, and appropriate flexibility is obtained.

In one embodiment of the thermosetting composition, the total proportion of solid components (B), (C) and (H) may be 30 to 90% by mass, or 40 to 80% by mass, based on 100% by mass of the total of components (A) to (H).

In one embodiment of the thermosetting composition, from the viewpoints of optical properties, viscosity during molding, and material mechanical properties, it is preferable that the content of component (B) is 20 to 80 mass%, the content of component (C) is 0.01 to 30 mass%, and the content of component (H) is 3 to 30 mass%, based on a total of 100 mass% of components (A) to (H).

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

(Filling material)
Examples of the filler include silver, gold, silicon, silicon carbide, copper oxide, iron oxide, cobalt oxide, titanium carbide, cerium oxide, ITO (indium tin oxide), ATO (antimony trioxide), hydroxyapatite, graphene, graphene oxide, single-walled carbon nanotubes, multi-walled carbon nanotubes, fullerene, diamond, mesoporous carbon, etc. Silicon carbide and titanium carbide are preferred, and titanium oxide and titanium carbide are more preferred in that they can maintain whiteness.

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

The filler may be used alone or in combination of two or more types.

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

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

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

In order to promote the polymerization reaction, a polymerization initiator may be contained. The polymerization initiator is not particularly limited, but examples thereof include radical polymerization initiators.
The radical polymerization initiator is not particularly limited, but examples thereof include ketone peroxides, hydroperoxides, diacyl peroxides, dialkyl peroxides, peroxyketals, alkyl peresters (peroxy esters), and peroxycarbonates.

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

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

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.

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

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-butylperoxypentanoic acid butyl.

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-butyl peroxyhexahydroterephthalate, 1,1,3,3-tetramethylbutyl peroxy Examples of peroxy compounds include 3,5,5-trimethylhexanate, t-amylperoxy 3,5,5-trimethylhexanoate, t-butylperoxy 3,5,5-trimethylhexanoate, t-butylperoxy acetate, t-butylperoxy benzoate, dibutylperoxy trimethyl adipate, 2,5-dimethyl-2,5-di-2-ethylhexanoylperoxyhexane, t-hexylperoxy 2-ethylhexanoate, t-hexylperoxy isopropyl monocarbonate, t-butylperoxy laurate, t-butylperoxy isopropyl monocarbonate, t-butylperoxy 2-ethylhexyl monocarbonate, and 2,5-dimethyl-2,5-di-benzoylperoxyhexane.

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.

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

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

Examples of antioxidants include phenol-based antioxidants, phosphorus-based antioxidants, sulfur-based antioxidants, vitamin-based antioxidants, lactone-based antioxidants, and amine-based antioxidants.

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

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

Sulfur-based antioxidants include dilauryl thiodipropionate, distearyl thiodipropionate, dimyristyl thiodipropionate, lauryl stearyl thiodipropionate, pentaerythritol tetrakis (3-dodecyl thiopropionate), pentaerythritol tetrakis (3-lauryl thiopropionate), etc. Commercially available products that can be used include, for example, DSTP "Yoshitomi", DLTP "Yoshitomi", DLTOIB, DMTP "Yoshitomi" (all manufactured by API Corporation), Seenox 412S (manufactured by Shipro Chemical Co., Ltd.), Cyanox 1212 (manufactured by Cyanamid Co., Ltd.), and SUMILIZER TP-D (manufactured by Sumitomo Chemical Co., Ltd.) (all trade names).

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

Amine-based antioxidants include commercially available products such as IRGASTAB FS 042 (manufactured by BASF) and GENOX EP (manufactured by Crompton, chemical name: dialkyl-N-methylamine oxide) (all trade names).

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

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

Specific examples of ultraviolet absorbers include ADK STAB LA-31, ADK STAB LA-32, ADK STAB LA-36, ADK STAB LA-29, ADK STAB LA-46, ADK STAB LA-F70, ADK STAB 1413 (all manufactured by ADEKA CORPORATION), Tinuvin P, Tinuvin 234, Tinuvin 326, Tinuvin 328, Tinuvin 329, Tinuvin 213, Tinuvin 571, Tinuvin 765, Tinuvin 1577ED, Chimassorb 81, Tinuvin 120 (all manufactured by BASF), etc. Among these, the Tinuvin series manufactured by BASF is preferred, with Tinuvin 765 being even more 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 is preferably 0.001 to 20 parts by mass based on 100 parts by mass in total of components (A) to (G), from the viewpoint of not impairing the effects of the present invention.

The release agent may include an internal release agent.
The internal mold release agent is preferably one that dissolves in the (meth)acrylate compound and disperses well, and is in a low-viscosity molten state when cured, which facilitates molecular motion, and is separated from the curing resin component when cured and exists between the mold and the curing component, thereby providing releasability, and is preferably one that has a low viscosity in a molten state when released, which further enhances releasability. There is no particular specification for the internal mold release agent, but an aliphatic compound is preferable.

The melting point of the aliphatic compound used as the internal release agent is preferably in the range of -40°C to 180°C, and more preferably in the range of -30°C to 180°C. By making the melting point of the aliphatic compound -40°C or higher, it is possible to achieve good release properties without vaporizing during curing and causing bubbles in the product, which would result in poor appearance. In addition, by making the melting point of the aliphatic compound 180°C or lower, the solubility is improved, resulting in good appearance and release properties.

（式（Ｖ）中、Ｒ^４は、炭素数６～３０の脂肪族炭化水素基を示す。
　Ｗは、水素原子、金属原子又は炭素数１～８の炭化水素基を示す。
　尚、Ｗが金属原子である場合、ＯとＷはイオン結合している。） The aliphatic compound is preferably a compound represented by the following formula (V).

In formula (V), R ⁴ represents an aliphatic hydrocarbon group having 6 to 30 carbon atoms.
W represents a hydrogen atom, a metal atom or a hydrocarbon group having 1 to 8 carbon atoms.
In addition, when W is a metal atom, O and W are ionic bonded.)

The aliphatic hydrocarbon group of ^R4 in formula (V) may have a straight-chain structure or a branched structure, and the bond state in the molecular chain may be only a single bond or may contain multiple bonds. Specific examples include aliphatic saturated hydrocarbon groups and aliphatic unsaturated hydrocarbon groups. The number of multiple bonds in the aliphatic unsaturated hydrocarbon group may be one or more.

The number of carbon atoms in the hydrocarbon group of R ⁴ in formula (V) is 6 to 30. If the number of carbon atoms is less than 6, it may volatilize during curing, and the aliphatic compound may not exist between the mold and the material, resulting in failure to develop releasability or air bubbles remaining in the material. If the number of carbon atoms is more than 30, the mobility of the material may be reduced, and the aliphatic compound may be incorporated into the material, making the material opaque or failing to develop releasability. The number of carbon atoms in the hydrocarbon group of R ⁴ in formula (V) is preferably 6 to 26, and more preferably 8 to 22.

The metal atom in W of formula (V) includes alkali metals such as lithium and sodium, alkaline earth metals such as magnesium and calcium, zinc, and aluminum.
When W is an alkaline earth metal or aluminum, it has a valence of 2 or more, so that the aliphatic compound represented by the formula (V) is represented by (R ⁴ --CO--O) _q --W, where q is 2 to 4.

The aliphatic hydrocarbon group in W of formula (V) may have a straight-chain structure or a branched structure, and the bond state in the molecular chain may be only a single bond or may contain multiple bonds. Specific examples include aliphatic saturated hydrocarbon groups and aliphatic unsaturated hydrocarbon groups.
The number of multiple bonds in the aliphatic unsaturated hydrocarbon group may be one or more. The carbon number of the aliphatic hydrocarbon group of W is 1 to 8. If the carbon number is 8 or more, the melting point of the aliphatic compound increases and the solubility decreases, and the aliphatic compound may be incorporated into the resin component during curing or may be unevenly distributed, resulting in failure to exhibit releasability or becoming opaque. The carbon number of the aliphatic hydrocarbon group of W is preferably 1 to 6.

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

Examples of release agents include magnesium stearate and zinc stearate.

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

In one embodiment, the thermosetting composition essentially consists of components (A) to (F), and optionally components (G) and (H), a filler, and additives, and may contain other inevitable impurities as long as they do not impair the effects of the present invention.
For example, 85% by weight or more, 95% by weight or more, or 99% by weight or more, or 100% by weight of the thermosetting composition of one embodiment is
It may consist of components (A) through (F), or components (A) through (F) and, optionally, components (G) and (H), fillers, and additives.

The thermosetting composition of this embodiment can be prepared by mixing the above components in a predetermined ratio. There are no particular limitations on the mixing method, and any known means such as a stirrer (mixer) can be used. In addition, mixing can be performed at room temperature, under cooling, or under heating, and under normal pressure, reduced pressure, or increased pressure.

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

In one embodiment, the thermosetting composition has a viscosity of 1 to 500 mPa·s at 25° C. and a shear rate of 10 s ⁻¹ for a mixture of components (A) and (D) to (F) among the components contained in the thermosetting composition, and more preferably 1 mPa·s or more and less than 100 mPa·s.
When the viscosity of the mixture of components (A) and (D) to (F) is within the above range, the thermosetting composition has excellent fluidity and high filling ability, and the resulting cured product has excellent flexibility.
The viscosity at 25° C. and a shear rate of 10 s ⁻¹ is determined by the method described in the examples.

According to the thermosetting composition of this embodiment, the solidified state can be maintained at a cooling temperature that can be realized by general cooling equipment, so that the solid-liquid separation phenomenon in the thermosetting composition is suppressed, and a stable storage state can be easily maintained, and the storage stability is excellent.
Furthermore, the thermosetting composition of this embodiment is a suitable material, for example, as a reflective material for optical semiconductors, and the resulting cured product has excellent flexibility and is less susceptible to cracking, chipping, and the like due to slight impact. This makes it possible to reduce the rate of defective molded products (e.g., reflectors) and achieve high production stability.
Furthermore, the thermosetting composition of this embodiment provides a cured product that has excellent flexibility, heat resistance, and light resistance, and is less susceptible to problems such as yellowing after long-term exposure to light or heat, for example, when used for a long period of time as a reflector for an optical semiconductor.
Furthermore, the thermosetting composition of this embodiment provides a cured product that has excellent flexibility and is suppressed from warping, thereby providing a cured product that combines flexibility with an excellent appearance.
In addition, according to one embodiment of the thermosetting composition using a white pigment as component (C), a cured product can be obtained which has high reflectance in the visible light region, excellent whiteness, excellent heat resistance and light resistance, and excellent adhesion to surrounding components (e.g., lead frames).

2. Manufacturing method of molded product A manufacturing method of a molded product according to one aspect of the present invention is characterized by including a step of supplying the above-mentioned thermosetting composition into a plunger (supplying step), a step of filling a molded product portion (cavity) of a mold having the molded product portion (cavity) with the supplied thermosetting composition by the plunger (filling step), a step of thermally curing the filled thermosetting composition in the molded product portion (curing step), and a step of pushing out the thermoset resin (mold releasing step).

In one embodiment of the method, in order to prevent only the resin component from being filled, transfer molding such as LTM (Liquid Transfer Molding), compression molding, or injection molding such as LIM (Liquid Injection Molding) is preferred. Preliminary polymerization may also be performed.

By using the above-mentioned thermosetting composition, when filling the inside of a mold with pressure, or when too much dwell pressure is applied after filling, the thermosetting composition can fill even gaps as small as 1 μm.

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

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

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

The above-mentioned molding machine preferably includes a plunger and a mold having a molded part. The above-mentioned molding machine preferably further includes a shut-off nozzle.

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

As the filling device 10, a filling device having a known plunger can be used. Normally, as shown in FIG. 1, a filling device 10 having a plunger 11 is equipped with a feed section and a check valve function, and the check valve 12 (which may be in the form of a screw) is moved back and forth to feed, stir and mix the material introduced from an inlet (not shown). However, in this embodiment, since a thermosetting composition, which is a homogeneous liquid, is introduced, stirring and mixing are not necessary.

In the process 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 carrying out the molding method of one embodiment of the present invention using the device shown in Figure 2, the above-mentioned flow path corresponds to the flow path (not shown) of the thermosetting composition in the filling device 10 and the introduction path in the mold 20.

In the method according to one embodiment of the present invention, a gate system is provided in a flow passage between the plunger and the cavity to block the flow of the curing liquid and the transfer of heat in the step of filling the cavity in the mold with the thermosetting composition filled in the plunger. Hereinafter, the molding method according to one embodiment of the present invention will be described with reference to FIG.
2 is used to carry out the method according to one embodiment of the present invention, the needle 223 and the opening 222 correspond to the gate system. As described above, the needle 223 moves to the movable mold 23 side and closes the opening 222, thereby cutting off the introduction path 221 before the heating section 22A, and 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 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 one embodiment of the present invention, the temperature of the mold 23 constituting the cavity portion is preferably set to 100°C or more and 180°C or less.
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 10° C. or more and 50° C. or less.
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.

In FIG. 1 the feeding process is shown.
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 a filling device 10 shown in Fig. 1 through an inlet (not shown). The injected thermosetting composition is pushed out into a check valve 12, and then a predetermined amount is measured by a plunger 11. After measurement is completed or before injection, the check valve 12 moves forward, and functions 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.

The filling process is shown, for example, in FIG.
When injecting the thermosetting composition into the cavity, it is preferable to reduce the pressure inside the cavity by providing a vent to release the air inside the cavity, or a hole that is connected to a pressure reducing device such as the pressure reducing pipe 240 in Fig. 2 and allows the cavity to be depressurized. The reason is that in the process of injecting the thermosetting composition into the cavity and completely filling it, the vent is for releasing the air inside the cavity, and the depressurization inside the cavity is for making it possible to completely fill it by making it airless. If there is no such mechanism, it is preferable to have a mechanism that allows the air inside the cavity to escape when the material is filled (for example, a vent mechanism).
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.

The cavity is preferably filled with the thermosetting composition 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, 60° C. or higher, preferably 100° C. or higher and 180° C. or lower, and particularly preferably 110° C. or higher and 170° C. or lower.
When using an injection molding machine, when starting injection from the injection part into the cavity, the nozzle of the shut-off nozzle (or sometimes a valve gate) is opened, the plunger of the injection part is moved, and the thermosetting component is injected into the cavity. When using a transfer molding machine, since the entire part from the inside of the plunger to the cavity is cured, it is sufficient that the material can flow into the cavity, and there is no need to block the exchange of heat.

The curing step is shown, for example, in FIG.
When the filling of the thermosetting composition into the cavity 21 is completed, the thermosetting composition starts curing at the same time, but in order to improve the transferability of the molded product, it is preferable to apply a predetermined pressure to cure the composition. That is, it is preferable that the plunger 11 is pressurized to 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.
In the curing process, pressure is preferably held (pressure applied to the thermosetting composition is increased) after the start of heat curing and before the completion of curing, and after pressure is held, the gate of the gate system is closed to perform heat curing. Specifically, the gate is closed by moving the needle 223 forward to close the opening 222. In the molding process, the 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, it is preferable to maintain the entire flow path at 10°C or higher and 50°C or lower, and it is particularly preferable to set it to 30°C or lower.

The following describes the pressure holding by the plunger 11 and the timing of starting the pressure holding. Figure 3 is a diagram showing the relationship between viscosity and time for the thermosetting composition of this embodiment. In Figure 3, the period P1 from when the material is injected into the cavity until filling is complete corresponds to the induction period until heat is applied to the material and hardening begins. The hardening process is divided into two stages: the early hardening stage P2, from when the material begins to harden when heat is applied until it is completely hardened, and the late hardening stage P3, when hardening is completed. 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 hardening stage P2, and rises gradually at a high viscosity during the late hardening stage P3.

In the initial curing stage P2, not only does the thermosetting composition change from liquid to solid, but it also changes 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. In order to improve the transferability, it is preferable to apply pressure to the thermosetting composition (holding pressure), to make the thermosetting composition adhere to the mold 20, and to fill the thermosetting composition from the gate portion.
However, in the thermosetting composition of this embodiment, when pressure is applied in a low viscosity state, there is a risk of a defect phenomenon in which the material leaks out from the gap between the fixed mold 22 and the movable mold 23 and hardens (burrs), or the thermosetting composition penetrates into the gap around the ejector pin, causing the ejector pin to malfunction. On the other hand, even if pressure is applied in a state where the viscosity is high in the early curing stage P2 or in the late curing stage P3, the thermosetting composition cannot be compressed and deformed due to its high viscosity, and transferability cannot be improved. Therefore, in order to obtain a molded product with high transferability, it is preferable to match the timing of the start of the dwell pressure (the start time T of the dwell pressure) with the timing of the transition from the induction period P1 to the early curing stage P2 of the curing process.

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 according to this embodiment begins to shrink at the same time as thickening at the initial curing stage P2, it is preferable to detect the time when the shrinkage starts, so that the dwell start time T can be appropriately determined.

In the curing step, by maintaining the pressure under the above-mentioned conditions, sink marks and distortion of the molded product can be prevented and transferability can be improved.
After the pressure has been maintained for a certain period of time, needle 223 is advanced to close opening 222 as shown in FIG. 2C, and the thermosetting composition is completely cured by heating for a certain period of time so as to prevent any uncured portions from being formed.
Here, the plunger 11 is advanced to fill the cavity 21 of the mold 20 with the thermosetting composition, and the time required for filling is t _1. When filling is completed, the plunger 11 stops. In addition, when the curing of the thermosetting composition starts, the thermosetting composition simultaneously shrinks, so the plunger 11, which had stopped after the completion of the filling step, starts advancing again. The time required from the completion of the filling step until the plunger 11 starts advancing again due to shrinkage is t _2. If the time required to completely cure the thermosetting composition by further heating is t ₃ , t ₁ + t ₂ + t ₃ (the total time required for the filling step and the thermosetting step) is preferably 0.2 to 3 minutes. More preferably, it is 0.2 to 2 minutes. If it is 0.2 minutes or less, there is a risk of uncuring, and if it is 3 minutes or more, it is not preferable from the viewpoint of mass productivity.

The demolding step is shown, for example, in FIG.
The hardened material 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.

3. Cured Product A cured product according to one embodiment of the present invention can be produced using the above-described thermosetting composition.
In one embodiment, the cured product is preferably a molded article.

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

The reflector described above has a high reflectance in the visible light region, and the reflectance does not decrease much even after long-term use. The reflector has an initial light reflectance at a wavelength of 450 nm of preferably 85% or more, more preferably 90% or more, and even more preferably 93% or more, and the amount of decrease in the light reflectance from the initial reflectance after a 1,000-hour deterioration test at 150°C is preferably 20% or less, more preferably 15% or less, and even more preferably 10% or less. In addition, the amount of decrease in the light reflectance from the initial reflectance after a 72-hour deterioration test at 180°C is preferably 9% or less, and even more preferably 4% or less.
The light reflectance is determined by the method described in the examples.

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

The cured product according to this embodiment has excellent flexibility and a small flexural modulus. The flexural modulus of the cured product is preferably 10 to 10,000 MPa, more preferably 10 to 6,000 MPa, and even more preferably 20 to 4,500 MPa.
In addition, the cured product according to this embodiment has excellent flexibility and a large amount of strain at break measured in accordance with JIS K7171: 2016. The amount of strain at break of the cured product is preferably 0.5% or more, more preferably 0.7% or more, and even more preferably 0.8% or more.
The flexural modulus and the amount of strain at break are determined by the method described in the examples.

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

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

FIG. 4(b) shows a substrate 520 for mounting optical semiconductor elements, in which a cured material is molded as a reflector 521 on the lead frame 510 of FIG. 4(a). The substrate 520 for mounting optical semiconductor elements has a recess that is composed of a bottom surface composed of the lead frame 510 and the reflector 521, and an inner peripheral side surface composed of the reflector 521. The cured material that constitutes the reflector 521 is obtained by curing the thermosetting composition of this embodiment.

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

FIG. 5 is a schematic cross-sectional view showing another embodiment of an optical semiconductor element mounting board and an optical semiconductor light emitting device.
FIG. 5( a ) shows a lead frame 610 .
Fig. 5(b) shows an optical semiconductor element mounting substrate 620 in which a cured material is molded as a reflector 621 between the lead frames 610 in Fig. 5(a). The optical semiconductor element mounting substrate 620 includes the lead frames 610 and the above-mentioned reflector 621 between the lead frames 610.

Fig. 5(c) shows an optical semiconductor light emitting device 630 equipped with the optical semiconductor element mounting substrate of Fig. 5(b). After mounting an optical semiconductor element 631 on a lead frame 610 and electrically connecting it with a bonding wire 632, the sealing resin part consisting of a transparent sealing resin 633 is hardened and molded in one go by a method such as transfer molding or compression molding to seal the optical semiconductor element 631, and then the device is diced into individual pieces. The sealing resin may contain a phosphor 634 for converting light emitted from blue or other colors to white.

The dimensions and shapes of each part of the substrate for mounting optical semiconductor elements are not particularly limited and can be set appropriately. The sealing resin (sealing material) is composed of, for example, epoxy resin, silicone resin, acrylate resin, etc.

The present invention will be explained in more detail below with reference to examples, but the present invention is not limited to these examples.

Examples 1 to 38 and Comparative Examples 1 to 8
(Preparation of Thermosetting Composition)
Thermosetting compositions were prepared by blending components (A) to (H) in the amounts shown in Tables 1 to 10. In Tables 1 to 10, the blend amounts of components (A) to (H) are shown based on 100 mass % being the total blend amounts of components (A) to (H).
Details of each component will be described later.
In addition, the liquid components (A) and (D) to (F) shown in Tables 1 to 10 each contain 1.0 part by weight of Perhexa HC (manufactured by NOF Corporation) as a polymerization initiator.

Specifically, the thermosetting composition was prepared by first weighing out the components (A) and (D) to (F), mixing and stirring them, then weighing out and adding the components (H), (C) and (B) in that order, and finally stirring to obtain the thermosetting composition.
The stirring device used was capable of stirring by rotation and revolution. The rotation speed was 1000 rpm and the revolution speed was 2000 rpm. The rotation time was 1 minute.

(Measurement of Viscosity of Monomer Components in Thermosetting Composition)
The mixture obtained by stirring and mixing the above-mentioned components (A) and (D) to (F) was subjected to viscosity measurement at a shear rate of 10 s ^-1 using a melt viscoelasticity analyzer Physica MCR301 (manufactured by Anton Paar) under the following method and conditions before being mixed with components (H), (C), and (B).
Measurement method: Coaxial cylinder rotational viscosity measurement method (based on JIS Z8803:2011)
Plate diameter: 25 mmφ, temperature: 25°C, shear rate: 10 s ^-1
A viscosity of less than 100 mPa·s was rated "◯", and a viscosity of 100 mPa·s or more was rated "×". The results are shown in Tables 1 to 10.

The ratios I and II shown in Tables 1 to 10 indicate the following ratios.
Ratio I = (total content of component (α) which is a component contained in components (A), (D) to (F) and has a melting point Tm of -5°C or higher) / (total content of components (A), (D) to (F)) x 100
Ratio II = (Total content of components (B), (C) and (H)) / (Total content of components (A) to (H)) x 100

The following was used as component (A):
Adamantyl methacrylate (MADMA, manufactured by Osaka Organic Chemical Industry Co., Ltd., viscosity at 25° C.: 5 mPa·s, melting point Tm (hereinafter sometimes simply referred to as Tm) <−15° C.)
Cyclohexyl methacrylate (Light Ester CH, manufactured by Kyoeisha Chemical Co., Ltd., viscosity at 25°C: 5 mPa·s, Tm<-15°C)
1-Isobornyl methacrylate (IB-X, manufactured by Kyoeisha Chemical Co., Ltd., viscosity at 25°C: 5 mPa·s, Tm<-15°C)
1-Isobornyl acrylate (SR506, manufactured by Arkema Co., Ltd., viscosity at 25°C: 5 mPa·s, Tm<-15°C)
Tricyclodecane dimethanol dimethacrylate (product name DCP, manufactured by Shin-Nakamura Chemical Co., Ltd., viscosity at 25°C: 110 mPa·s, Tm<-15°C)
Tricyclodecane dimethanol diacrylate (product name: A-DCP, manufactured by Shin-Nakamura Chemical Co., Ltd., viscosity at 25°C: 135 mPa·s, Tm<-15°C)

The viscosity of component (A) was measured in the same manner as described above in the section "Measurement of viscosity of monomer components in a thermosetting composition."

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

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

The average particle size (D50) of component (B) and the average particle size of component (D) described below were measured using a laser diffraction particle size distribution measuring device SALD-300V (manufactured by Shimadzu Corporation).
Each of components (B) and (D) was dispersed in a toluene solvent, and the concentration was increased from a small amount so that the scattering intensity became measurable. The concentration was appropriately adjusted to a concentration that allowed particle size measurement, and the weight of the particles added was determined.

The following was used as component (C):
PFC310: Titanium oxide, primary average particle size: 0.2 μm (manufactured by Ishihara Sangyo Kaisha, Ltd.)
MA100R: Carbon black, primary average particle size: 0.025 μm (manufactured by Mitsubishi Chemical Corporation)
TM-B: low-order titanium oxide, primary average particle size: 0.7 μm (manufactured by Ako Kasei Co., Ltd.)

The average primary particle size of component (C) was determined by dispersing component (C) in ethylene glycol, preparing frozen sections, depositing gold on them, and using a scanning electron microscope to measure the maximum lengths of 150 primary particles per field of view in five locations of 0.25 μm x 0.25 μm, and then taking the arithmetic average.

The following was used as component (D):
Glycidyl methacrylate (Kyoeisha Chemical Co., Ltd., Tm<-15°C)

The following was used as component (E):
Lauryl methacrylate (SR313, Arkema, Tm = -6°C)
Stearyl methacrylate (Light Ester S, Kyoeisha Chemical Co., Ltd., Tm = 20°C)
n-Butyl methacrylate (NB, manufactured by Kyoeisha Chemical Co., Ltd., Tm<-15°C)
Isodecyl methacrylate (ID, manufactured by Kyoeisha Chemical Co., Ltd., Tm<-15°C)
MMA: Methyl methacrylate (Hiroshima Wako Co., Ltd., Tm<-15°C)
Stearyl acrylate (product name: Light Acrylate S-A, manufactured by Kyoeisha Chemical Co., Ltd., Tm = 35°C)
Lauryl acrylate (product name: Light Acrylate LA, manufactured by Kyoeisha Chemical Co., Ltd., Tm = 4°C)

The following was used as component (F).
1,6XH-A: 1,6-hexanediol diacrylate (manufactured by Arkema, Tm<-15°C)
SR-351: Trimethylolpropane triacrylate (manufactured by Arkema, Tm<-15°C)
A-DON-N: 1,10-decanediol diacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd., Tm=20° C.)
3000MK: an epoxy ester compound represented by the following formula (i) (manufactured by Kyoeisha Chemical Co., Ltd., Tm<-15°C).

　ＣＮ２２８３：ポリエスエルアクリレートオリゴマー（アルケマ社製、Ｔｍ＜－１５℃）

CN2283: Polyester acrylate oligomer (Arkema, Tm<-15°C)

1,9ND-A: 1,9-nonanediol diacrylate (manufactured by Kyoeisha Chemical Co., Ltd., Tm=20° C.)
BPE-80N: Bifunctional ethoxylated bisphenol A-diacrylate (Kyoeisha Chemical Co., Ltd., Tm<-15°C)

As component (G), the following MMA-Butyl-MMA terpolymer was used.
LA4285 (manufactured by Kuraray Co., Ltd., repeating units (G1): 50 mol%, (G2): 50 mol%)
LA3320 (manufactured by Kuraray Co., Ltd., repeating units (G1): 20 mol%, (G2): 80 mol%)
LA3710 (manufactured by Kuraray Co., Ltd., repeating unit (G1): 10 mol%, (G2): 90 mol%)

The following was used as component (H).
FH105: Talc, average particle size (D50) 5 μm (manufactured by Fuji Talc Industry Co., Ltd.)
JM-209: Talc, average particle size (D50) 3.9±0.4 μm (manufactured by Asada Flour Milling Co., Ltd.)
ST-95: Calcined talc, average particle size 5 μm (manufactured by Nippon Talc Co., Ltd.)
A-11: Mica, average particle size 3 μm (manufactured by Yamaguchi Mica Co., Ltd.)
Satintone W: Calcined kaolin, average particle size 1.4 μm (manufactured by Takehara Chemical Industry Co., Ltd.)

[Characteristics evaluation]
The following items were measured and evaluated, and the results are shown in Tables 1 to 10.
(Viscosity Measurement of Thermosetting Composition)
The viscosity of the obtained thermosetting composition was measured at a shear rate of 10 s ⁻¹ under the following conditions using a viscoelasticity measuring device Physica MCR301 (manufactured by Anton Paar) in accordance with JIS K7117-2.
A viscosity of less than 60 Pa·s was marked as "◯", and a viscosity of 60 Pa·s or more was marked as "X".
Measurement method: Coaxial cylinder type rotational viscosity measurement method Temperature: 25°C
Shear rate range: 0.1 to 200 ^s

(Evaluation of storage stability)
The storage stability was measured by the following method and evaluation criteria.
First, 5 kg of the obtained thermosetting composition was placed in a cylindrical container having a bottom diameter of 186 mm, and left for 90 days in a freezer maintained at a temperature of −10° C. After 90 days had passed, the temperature of the container was returned to room temperature, and a storage test was performed in which the container was left for an additional 3 days.
After three days had passed, the thermosetting composition contained in the container was sampled from near the liquid surface, and the viscosity was measured in the same manner as described in the above section "Viscosity measurement of thermosetting composition."
Based on the viscosity measured for the thermosetting composition before the storage test, a case in which the decrease in viscosity of the thermosetting composition after the storage test was within 20% was marked as "O", and a case in which the decrease was greater than that was marked as "X".
In other words, if the decrease in viscosity of the thermosetting composition after the standing test exceeds 20%, this indicates that the resin component and the inorganic component contained in the thermosetting composition are separated during the standing test, and the content of the inorganic component in the supernatant of the thermosetting composition is reduced compared to that of the thermosetting composition before the standing test.

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

The LIM molding was carried out under the following conditions.
Molding machine: Liquid thermosetting resin injection molding machine LA-40S (manufactured by Sodick Co., Ltd.)
Measurement with the plunger of the molding machine: 1 ^cm3
Flow path temperature in low temperature section: 15°C
Flow path and heat blocking method: Shut-off nozzle used Flow path temperature and cavity temperature in high temperature area: 145°C
Filling time: 5 seconds Filling pressure: 10MPa or less (filling time takes priority)
Dwell time: 15 seconds Dwell pressure: 15 MPa
Curing time: 90 seconds

(Production of molded product 2)
The above-mentioned thermosetting composition was subjected to LTM molding under the following conditions to obtain a molded article (cured product) 2.
The mold used was 50 mm long, 50 mm wide, and 2 mm thick.

The LTM molding was carried out under the following conditions.
Molding machine: Liquid transfer molding machine G-Line (manufactured by Apic Yamada Co., Ltd.)
Measurement with the plunger of the molding machine: 6 ^cm3
Flow path temperature in low temperature section: 25°C
Flow path and blocking method: Manual blocking using a syringe Flow path temperature and cavity temperature in high temperature area: 150°C
Filling time: 5 seconds Filling pressure: 15MPa or less (filling time takes priority)
Dwell time: 15 seconds Dwell pressure: 15 MPa
Curing time: 90 seconds

(Evaluation of filling ability)
The filling property was visually confirmed in filling the thermosetting composition in the production of the above-mentioned molded product 1. The case where no voids were generated and no unfilled portions were generated was marked with "◯". The case where voids were generated and unfilled portions were generated was marked with "X".

(Evaluation of the presence or absence of burrs)
The obtained molded product 1 was visually evaluated for the presence or absence of burrs. A case in which there was no burr beyond the end of the vent and no burr was present in areas other than the vent was marked as "good." A case in which there was a burr beyond the end of the vent and there was a burr in areas other than the vent was marked as "bad."

(Evaluation of continuous moldability 1)
The above-mentioned production of molded product 1 was repeated 300 times in succession. After the 300 repetitions, clogging of the flow passages in the low temperature section due to the thermosetting composition was evaluated.
Furthermore, out of the 300 consecutive repetitions, the molded product 1 from the 10th repetition and the molded product 1 from the 300th repetition were weighed. The difference between the weighed value of the molded product 1 from the 10th repetition and the weighed value of the molded product 1 from the 300th repetition was divided by the weighed value of the molded product 1 from the 10th repetition to obtain a percentage, from which the weighing error due to clogging was calculated.
The case where the flow path was not clogged and the absolute value of the measurement error was 15% or less was marked as "good." The case where the flow path was clogged or the absolute value of the measurement error exceeded 15% was marked as "bad."

(Evaluation of continuous moldability 2)
The above-mentioned manufacturing process of molded product 1 was repeated 100 times. After that, the molded product was left for 24 hours, and molded 100 times. After a total of 200 times, clogging of the flow path in the low temperature section due to the thermosetting composition was evaluated. In addition, the difference between the measurement value of molded product 1 in the 10th of the first 100 times and the measurement value of molded product 1 in the 100th of the last 100 times was divided by the measurement value of molded product 1 in the 10th time to obtain a percentage, and the measurement error due to clogging was obtained.
The case where the flow path was not clogged and the absolute value of the measurement error was 15% or less was marked as "good." The case where the flow path was clogged or the absolute value of the measurement error exceeded 15% was marked as "poor."

(Measurement of Light Reflectance)
The reflectance of the obtained molded article 2 was measured using an integrating sphere spectrophotometer CE-7000A (manufactured by GretagMacbeth) in the wavelength range of 400 to 700 nm under the conditions of reflectance measurement mode, 10-degree visual field, diffuse illumination/8-degree directional light reception, color measurement area of 5 mm × 10 mm, and including specular reflection and ultraviolet light, and the light reflectance of the molded article 2 at 450 nm was obtained.

(Evaluation of light resistance (LED current test))
The above molded article 2 was fixed on an LED package equipped with a blue LED (manufactured by Genelites Co., Ltd., product name: OBL-CH2424), and electricity was passed through it for one week at an environmental temperature of 60° C. at a current value of 150 mA to cause it to emit light. After one week, the surface of the molded article 2 irradiated with the blue LED light was visually observed and evaluated according to the following criteria.
○: No discoloration compared to before irradiation ×: Discoloration turned brown compared to before irradiation

(Evaluation of heat resistance)
After the above-mentioned measurement of the light reflectance (initial reflectance), the molded product 2 was heated at 180° C. for 72 hours.
After heating, the reflectance was measured in the same manner as in the measurement of the light reflectance described above, and the light reflectance of the molded article 2 at 450 nm (reflectance after heating) was determined.
The difference between the initial reflectance and the reflectance after heating was divided by the initial reflectance, and the absolute value of the percentage was expressed as a percentage of less than 5%, which was marked as "good", "at least 5% but less than 10%" was marked as "good", and "at least 10%" was marked as "bad".

(Measurement of bending elastic modulus, measurement of strain at break)
The obtained molded product 2 was subjected to measurement of bending elastic modulus and measurement of strain at break in accordance with JIS K7171:2016, and evaluated according to the following evaluation criteria.
Good: The flexural modulus is 7 GPa or less, and the strain at break is 0.7% or more. Bad: The flexural modulus is more than 7 GPa, or the strain at break is less than 0.7%.

(Measurement of mold shrinkage in the MD direction of molded product)
The shrinkage rate in the MD direction of the obtained molded product 2 was measured in accordance with JIS K6911-1995.

As shown in Tables 1 to 8, the thermosetting compositions of Examples 1 to 38 all had excellent storage stability. In addition, the thermosetting compositions of Examples 1 to 38 had a small flexural modulus, a large amount of strain at break, and excellent flexibility, as well as excellent light resistance and heat resistance, a small shrinkage rate in the MD direction, and suppressed warping.

On the other hand, as shown in Tables 9 and 10, Comparative Examples 1 to 8 had a ratio I of less than 40%, and thus were poor in storage stability. In addition, Comparative Examples 1 to 8 had a large flexural modulus, a small amount of strain at break, and were poor in flexibility.
Among them, Comparative Examples 3 and 4 were inferior in flexibility as described above, and also inferior in heat resistance since they did not contain component (A).

The thermosetting composition and the cured product according to one aspect of the present invention are suitably used, for example, as a reflector for optical semiconductor devices.
The method for producing a molded article according to one embodiment of the present invention can be suitably used for molding, for example, a reflector for an optical semiconductor.

Although some embodiments and/or examples of the present invention have been described in detail above, those skilled in the art can easily make many modifications to these exemplary embodiments and/or examples without substantially departing from the novel teachings and advantages of the present invention, and therefore many such modifications are within the scope of the present invention.
The contents of all documents cited in this specification and of the application from which this application claims priority under the Paris Convention are incorporated by reference in their entirety.

Claims (19)

The following components (A), (B) and (C):
One or more selected from the group consisting of the following components (D) to (F);
A thermosetting composition comprising:
A thermosetting composition, comprising the following components (A) and (D) to (F), each of which has a melting point of -5°C or higher, in an amount of 40 mass% or more based on the total amount of the following components (A) and (D) to (F):
(A) a monofunctional or polyfunctional (meth)acrylate compound having, as an ester substituent, a substituted or unsubstituted group having an alicyclic hydrocarbon group having 6 or more ring carbon atoms, and having a viscosity of 1 to 300 mPa·s at 25°C; (B) spherical silica; (C) a pigment or dye; (D) a monofunctional (meth)acrylate compound having, as an ester substituent, a group having (meth)acrylic acid or a polar group; (E) a monofunctional (meth)acrylate compound having, as an ester substituent, a group other than the ester substituent of the component (A) and the ester substituent of the component (D); (F) a polyfunctional (meth)acrylate compound having, as an ester substituent, a group other than the ester substituent of the component (A). The thermosetting composition according to claim 1, wherein the substituted or unsubstituted alicyclic hydrocarbon group having 6 or more ring carbon atoms in component (A) is one or more groups selected from the group consisting of a substituted or unsubstituted adamantyl group, a substituted or unsubstituted norbornyl group, a substituted or unsubstituted isobornyl group, a substituted or unsubstituted tricyclodecanyl group, and a substituted or unsubstituted dicyclopentanyl group. The thermosetting composition according to claim 1 or 2, wherein component (B) is spherical silica that has been surface-treated with an acrylsilane or a methacrylsilane. The thermosetting composition according to any one of claims 1 to 3, wherein the average particle size (D50) of component (B) is 0.1 to 100 μm. The thermosetting composition according to any one of claims 1 to 4, wherein component (C) is a white pigment. The thermosetting composition according to any one of claims 1 to 4, wherein component (C) is a black pigment or a black dye. The thermosetting composition according to any one of claims 1 to 6, further comprising the following component (G):
(G) A block copolymer comprising at least one block of a repeating unit represented by the following formula (G1) and at least one block of a repeating unit represented by the following formula (G2):

(In formula (G1),
R ₄₀₁ is a hydrogen atom or a methyl group.
In formula (G2),
R ₄₀₂ is a hydrogen atom or a methyl group.
R ₄₀₃ is an alkyl group having 2 to 18 carbon atoms, —R ₄₁₁ OR ₄₁₂ , or —R ₄₁₃ SR ₄₁₄ .
R ₄₁₁ and R ₄₁₃ each independently represent an alkylene group having 1 to 30 carbon atoms.
R ₄₁₂ and R ₄₁₄ each independently represent an alkyl group having 1 to 30 carbon atoms. The thermosetting composition according to any one of claims 1 to 7 further comprises component (H) a flake-like filler. The thermosetting composition according to claim 8, wherein the total content of the components (B), (C) and (H) is 84% by mass or less, based on 100% by mass of the total of the components (A) to (H). The thermosetting composition according to any one of claims 1 to 9, wherein the mixture of components (A) and (D) to (F) has a viscosity of 1 to 500 mPa·s at 25°C and a shear rate of 10 ^s -1. The thermosetting composition according to any one of claims 1 to 10, which has a viscosity of 1 to 200 Pa·s at 25°C and a shear rate of 10 s ^-1 . A step of supplying the thermosetting composition according to any one of claims 1 to 11 into a plunger;
A step of filling the supplied thermosetting composition into a molded product portion of a mold by the plunger;
a step of thermally curing the filled thermosetting composition within the molded product portion; and a step of extruding the thermoset resin.
A method for producing a molded article comprising the steps of: The method for manufacturing a molded product according to claim 12, wherein the temperature of the mold part constituting the molded product portion is 100 to 180°C. The method for manufacturing a molded product according to claim 12 or 13, in which a flow path between the plunger and the molded product portion is temperature-controlled to 50°C or less, and the filling is carried out through the flow path. The method for manufacturing a molded product according to claim 14, further comprising a gate system in the flow path that blocks the flow of the thermosetting composition and the transfer of heat. The filling is performed by opening a gate of the gate system;
The method for producing a molded product according to claim 15, further comprising the steps of: performing pressure dwelling during the heat curing; and closing a gate of the gate system after the pressure dwelling to complete the heat curing. The method for manufacturing a molded product according to any one of claims 12 to 16, in which the filling step and the heat curing step are carried out for 0.2 to 3 minutes. A cured product produced using the thermosetting composition according to any one of claims 1 to 11. The cured product according to claim 18, which is a molded product.

Images