WO2015076309A1

WO2015076309A1 - Curable composition, cured product, camera module and method for manufacturing imaging device

Info

Publication number: WO2015076309A1
Application number: PCT/JP2014/080676
Authority: WO
Inventors: 賢太関川; 研一江畑; 海田　由里子; 陽介網野; 脩本間
Original assignee: 旭硝子株式会社
Priority date: 2013-11-21
Filing date: 2014-11-19
Publication date: 2015-05-28
Also published as: TW201525614A; JP2017014303A

Abstract

Provided is a curable composition which has low viscosity and provides a cured product having good heat resistance and good mold releasability. A curable composition which contains curable components including: 20-80% by mass of a compound (A) having (meth)acryloyloxy groups at both ends of an alkylene group; 5-50% by mass of a compound (B) having three (meth)acryloyloxy groups; 5-50% by mass of a compound (C) having four (meth)acryloyloxy groups; 0.1-20% by mass of a compound (D) having one or more (meth)acryloyloxy groups and a fluorine atom; 0-10% by mass of a compound (E) having one (meth)acryloyloxy group (excluding the compound (D)); and 0-40% by mass of a compound (F) having a fluorene skeleton and two (meth)acryloyloxy groups. The total of the compound (D) and the compound (E) is 0.1-20% by mass.

Description

Curable composition, cured product, camera module, and method of manufacturing imaging device

The present invention relates to a curable composition, a cured product of the curable composition, a camera module using the cured product, and a method of manufacturing an imaging device including the camera module.

Nanoimprint Lithography as a method for manufacturing optical articles with fine patterns on the surface (wire grid polarizing elements with fine line-and-space patterns, anti-reflection members with a moth-eye structure, etc.) The law is known.
For example, a curable composition is applied to the surface of a substrate, and light is irradiated in a state where the curable composition is sandwiched between a mold having a reverse pattern of a target fine pattern on the surface and the substrate. After curing the curable composition, the mold can be separated to produce a “molded body in which a cured resin layer having a desired fine pattern is formed on a substrate”.
In addition to performing the nanoimprint lithography method using such a molded body as a replica mold, the molded body itself may be an optical article.

As a curable composition used in the nanoimprint lithography method, Patent Document 1 discloses an aromatic compound having two or more rings or an alicyclic compound having two or more rings and 2 (meth) acryloyloxy groups. A compound (A) having a fluorine atom and one or more carbon-carbon unsaturated double bonds (excluding compound (A)), (meth) acryloyloxy A curable composition containing a compound (C) having one group (excluding the compound (B)) and a photopolymerization initiator (D) is described.
Furthermore, compound (E) having two (meth) acryloyloxy groups (excluding compound (A) and compound (B)), or compound (F) having three or more (meth) acryloyloxy groups ( However, it is described that compound (B) may be included.
In paragraph 0045 of Patent Document 1, many examples of the compound (E) having two (meth) acryloyloxy groups are listed, but the compound (E) used in the examples is only diethylene glycol dimethacrylate, There is no example using “a compound having a (meth) acryloyloxy group at both ends of an alkylene group”.

International Publication No. 2008/155928

In the curable composition used for the nanoimprint lithography method, it is required that the viscosity is low, the applicability is good, and the mold releasability is good.
Further, when the above-mentioned “molded body in which a cured resin layer having a desired fine pattern is formed on a base material” itself is an optical article mounted on a camera module, for example, in the assembly process of the camera module The molded body passes through a high-temperature process such as a solder reflow process. For this reason, the heat resistance after becoming a hardened material is requested | required of the curable composition used for manufacture of this molded object.
However, according to the knowledge of the present inventors, the curable composition specifically described in Patent Document 1 does not necessarily have sufficient heat resistance of the cured product. Moreover, there is no description regarding heat resistance in Patent Document 1, and it is unclear how heat resistance can be improved.

The present invention relates to a curable composition having a low viscosity and good heat resistance and releasability of a cured product, a cured product of the curable composition, a camera module using the cured product, and the camera module. It is an object of the present invention to provide a method for manufacturing an imaging apparatus provided.

The present invention includes the following [1] to [6].
[1] 20 to 80 mass% of the following compound (A), 5 to 50 mass% of the following compound (B), 5 to 50 mass% of the following compound (C), and 0.1 to 20 mass of the following compound (D) %, A curable component containing 0 to 10% by mass of the following compound (E) and 0 to 40% by mass of the following compound (F), and the total of the compound (D) and the compound (E) is 0.1 A curable composition of ˜20% by weight.
Compound (A): A compound having (meth) acryloyloxy groups at both ends of an alkylene group.
Compound (B): A compound having three (meth) acryloyloxy groups.
Compound (C): A compound having four (meth) acryloyloxy groups.
Compound (D): A compound having at least one (meth) acryloyloxy group and containing a fluorine atom.
Compound (E): Compound having one (meth) acryloyloxy group (excluding compound (D)).
Compound (F): A compound having a fluorene skeleton and two (meth) acryloyloxy groups.

[2] The curable composition according to [1], further including 1 to 10 parts by mass of the photopolymerization initiator (G) with respect to 100 parts by mass of the curable component.

[3] The above [1], wherein the photopolymerization initiator (G) is an alkylphenone photopolymerization initiator, an acylphosphine oxide photopolymerization initiator, a benzoin photopolymerization initiator, or a benzophenone photopolymerization initiator. The curable composition according to [2].
[4] A curable composition containing the following compound (A), the following compound (B), the following compound (C), and the following compound (D), and a photopolymerization initiator (G). A thing,
A curable composition having a film thickness maintenance ratio of 98% or more when a 2 μm-thick cured film obtained by irradiating the coating film comprising the curable composition with ultraviolet rays is heated at 260 ° C. for 20 minutes. .
Compound (A): Compound having (meth) acryloyloxy groups at both ends of an alkylene group.
Compound (B): A compound having three (meth) acryloyloxy groups.
Compound (C): A compound having four (meth) acryloyloxy groups.
Compound (D): A compound having at least one (meth) acryloyloxy group and containing a fluorine atom.
[5] The curable composition according to the above [4], wherein the curable component further comprises the following compound (E) and / or the following compound (F).
Compound (E): Compound having one (meth) acryloyloxy group (excluding compound (D)).
Compound (F): A compound having a fluorene skeleton and two (meth) acryloyloxy groups.
[6] The curable composition according to any one of [1] to [5] above, wherein the viscosity at 25 ° C. is 100 mPa · s or less.

[7] A cured product of the curable composition according to any one of [1] to [6].
[8] The cured product according to [7], wherein the surface has an uneven structure.
[9] The cured product according to the above [8], wherein the period of the convex part or the concave part is not more than the wavelength of visible light.
[10] The cured product according to [9], which is an antireflection film for a camera module.
[11] The cured product according to [10], which is an antireflection film formed on the surface of the cover glass on the solid-state imaging device.
[12] A camera module including an antireflection film made of the cured product according to [9].

[13] A step of manufacturing a camera module including a photographic lens and a solid-state imaging device that converts an optical image formed by the photographic lens into an electrical imaging signal;
A method of manufacturing an imaging apparatus including a step of mounting the camera module on a printed circuit board by a solder reflow method,
In the step of manufacturing the camera module, the curable composition according to any one of the above [1] to [6] is disposed on the surface of the cover glass of the solid-state imaging device, and the surface is made uneven by nanoimprint lithography. A method for manufacturing an imaging device, including a step of forming an antireflection film.

The curable composition of the present invention has a low viscosity, and the cured product formed from the curable composition has good heat resistance and releasability.
In addition, the camera module of the present invention has good heat resistance of the antireflection film, and performance degradation due to passing through a high-temperature process in the manufacturing process is suppressed.
Furthermore, the manufacturing method of the imaging device of the present invention has good heat resistance of the antireflection film of the camera module, and performance degradation due to passing through a high-temperature process such as solder reflow treatment is suppressed.

In the present specification, the curable component means a compound having a functional group having a polymerizable unsaturated bond (for example, a (meth) acryloyloxy group).
In the present specification, the (meth) acryloyloxy group means an acryloyloxy group or a methacryloyloxy group.
In the present specification, (meth) acrylate means acrylate or methacrylate.

<Curable composition>
The curable composition of the present invention contains a curable component. The curable component contains the following compound (A), the following compound (B), the following compound (C), and the following compound (D) as essential components. In addition, the following compound (E) and / or the following compound (F) can be included.
The curable composition of this invention contains an initiator (for example, photoinitiator (G)) as needed in addition to the curable component. Furthermore, other components (fluorine-containing surfactant (H), additive (I), etc.) can be included as necessary.
Compound (A): A compound having (meth) acryloyloxy groups at both ends of an alkylene group.
Compound (B): A compound having three (meth) acryloyloxy groups.
Compound (C): A compound having four (meth) acryloyloxy groups.
Compound (D): A compound having at least one (meth) acryloyloxy group and containing a fluorine atom.
Compound (E): Compound having one (meth) acryloyloxy group (excluding compound (D)).
Compound (F): A compound having a fluorene skeleton and two (meth) acryloyloxy groups.

The viscosity at 25 ° C. of the curable composition of the present invention is preferably 100 mPa · s or less, more preferably 80 mPa · s or less, and further preferably 50 mPa · s or less. If the viscosity of a curable composition is below the said upper limit, favorable applicability | paintability will be obtained.
The lower limit of the viscosity of the curable composition of the present invention is not particularly limited, but it is preferably 1 mPa · s or more, in terms of easy handling or easy maintenance of the shape of the coating film, and 5 mPa · s or more. Is more preferable.

The curable composition of the present invention preferably contains substantially no solvent. If the curable composition does not substantially contain a solvent, the curable composition can be used without performing a special operation (such as an operation of removing the solvent by heating the curable composition to a high temperature) excluding light irradiation. It is easy to cure the product.
A solvent is a compound having the ability to dissolve a curable component, and is a compound having a boiling point of 170 ° C. or less at normal pressure.
The solvent preferably has an ability to dissolve any of the initiator, the fluorine-containing surfactant (H) and the additive (I).
The phrase “substantially free of solvent” means that the solvent is 1% by mass or less in the curable composition (100% by mass). In the present invention, the solvent used in preparing the curable composition may be included as a residual solvent, but the residual solvent is preferably removed as much as possible, and the curable composition (100% by mass) Of these, 0.7% by mass or less is more preferable.

[Compound (A)]
The compound (A) is a compound having (meth) acryloyloxy groups at both ends of the alkylene group. By containing a compound (A) in a photocurable composition, the viscosity of a photocurable composition can be reduced, without impairing the heat resistance of hardened | cured material.
The alkylene group may be linear or may have a branched chain. Since the molecular chain is easily entangled and highly reactive, it is preferably linear. When molecular chains are entangled with each other, the number of physical crosslinking points increases, and the mobility of molecules can be suppressed even in a high temperature region, which is considered to exhibit high heat resistance. When the reactivity is high, the cured product is easily polymerized, and therefore, it is considered that high heat resistance is exhibited.
The alkylene group preferably has 4 to 12 carbon atoms, more preferably 6 to 10 carbon atoms. When the carbon number is 4 or more, the molecular chains are easily entangled, and when it is 12 or less, the crosslinking point density can be sufficiently increased.
Examples of the compound (A) include the following di (meth) acrylates.
1,6-hexanediol di (meth) acrylate, 1,9-nonanediol di (meth) acrylate, 1,10-decanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, 1,3-butane Diol di (meth) acrylate, 1,4-butanediol di (meth) acrylate, 3-methyl-1,5-pentanediol diacrylate, 2-methyl-1,8-octanediol diacrylate and the like.
Of these, 1,6-hexanediol di (meth) acrylate, 1,9-nonanediol di (meth) acrylate, or 1,10-decanediol di (meth) acrylate is preferable.

A compound (A) may be used individually by 1 type, and may use 2 or more types together.
The content of the compound (A) is 20 to 80% by mass in a total of 100% by mass of the curable components. 30 mass% or more is preferable and 40 mass% or more is more preferable. 70 mass% or less is preferable and 60 mass% or less is more preferable.
If content of a compound (A) is 20 mass% or more, the effect of reducing the viscosity of a photocurable composition will fully be acquired. Heat resistance can be sufficiently secured when the content is 80% by mass or less.

[Compound (B)]
Compound (B) is a compound having three (meth) acryloyloxy groups. A compound (B) contributes to the improvement of the heat resistance of hardened | cured material.
Examples of the compound (B) include the following tri (meth) acrylates.
Trimethylolpropane tri (meth) acrylate, trimethylolpropane ethoxytri (meth) acrylate, polyether tri (meth) acrylate, glycerin propoxytri (meth) acrylate, pentaerythritol tri (meth) acrylate, ethoxylated isocyanuric acid triacrylate, Ethoxylated trimethylolpropane triacrylate, propoxylated trimethylolpropane triacrylate and the like.
The compound (B) is preferably tetraol tri (meth) acrylate, particularly pentaerythritol tri (meth) acrylate.

A compound (B) may be used individually by 1 type, and may use 2 or more types together.
The content of the compound (B) is 5 to 50% by mass in a total of 100% by mass of the curable components. 8 mass% or more is preferable and 10 mass% or more is more preferable. 40 mass% or less is preferable and 30 mass% or less is more preferable.
If content of a compound (B) is 5 mass% or more, the heat resistant improvement effect of hardened | cured material will fully be acquired. If content of a compound (B) is 50 mass% or less, the viscosity of a curable composition can be restrained low.

[Compound (C)]
Compound (C) is a compound having four (meth) acryloyloxy groups. The compound (C) contributes to the improvement of the heat resistance of the cured product.
Examples of the compound (C) include the following tetra (meth) acrylates.
Pentaerythritol tetra (meth) acrylate, pentaerythritol ethoxytetra (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, propoxylated pentaerythritol tetraacrylate and the like.
The compound (C) is preferably tetraol tetra (meth) acrylate, particularly pentaerythritol tetra (meth) acrylate.
A compound (C) may be used individually by 1 type, and may use 2 or more types together.
The content of the compound (C) is 5 to 50% by mass in a total of 100% by mass of the curable components. 6 mass% or more is preferable and 8 mass% or more is more preferable. 40 mass% or less is preferable and 30 mass% or less is more preferable.
If content of a compound (C) is 5 mass% or more, the heat resistant improvement effect of hardened | cured material will fully be acquired. If content of a compound (C) is 50 mass% or less, the viscosity of a curable composition can be restrained low.
Of the total 100% by mass of the curable components, the total content of the compound (B) and the compound (C) is preferably 10% by mass or more, and more preferably 15% by mass or more. 60 mass% or less is preferable and 50 mass% or less is more preferable. The mass ratio of compound (B) / compound (C) is preferably 10/1 to 1/10, more preferably 5/1 to 1/5.

[Compound (D)]
The compound (D) is a compound having at least one (meth) acryloyloxy group and containing a fluorine atom. The compound (D) contributes to improvement of the release property of the cured product.
Examples of the compound (D) include the following fluoro (meth) acrylates.
3- (perfluoro-3-methylbutyl) -2-hydroxypropyl (meth) acrylate,
2,2,2-trifluoro-1- (trifluoromethyl) ethyl (meth) acrylate,
_{_{_{CH 2 = CHCOO (CH 2)}}} 2 (CF 2) 10 F,
_{_{_{CH 2 = CHCOO (CH 2)}}} 2 (CF 2) 8 F,
_{_{_{CH 2 = CHCOO (CH 2)}}} 2 (CF 2) 6 F,
_{_{_{CH 2 = CHCOO (CH 2)}}} 3 (CF 2) 10 F,
_{_{_{CH 2 = CHCOO (CH 2)}}} 3 (CF 2) 8 F,
_{_{_{CH 2 = CHCOO (CH 2)}}} 3 (CF 2) 6 F,
_{_{_{_{CH 2 = C (CH 3)}}}} COO (CH 2) 2 (CF 2) 10 F,
_{_{_{CH 2 = C (CH 3)}}} COO (CH 2) 2 (CF 2) 8 F,
_{_{_{CH 2 = C (CH 3)}}} COO (CH 2) 2 (CF 2) 6 F,
_{_{_{_{CH 2 = C (CH 3)}}}} COO (CH 2) 3 (CF 2) 10 F,
_{_{_{CH 2 = C (CH 3)}}} COO (CH 2) 3 (CF 2) 8 F,
_{_{_{CH 2 = C (CH 3)}}} COO (CH 2) 3 (CF 2) 6 F,
_{_{_{CH 2 = CHCOOCH 2 (CF 2}}} ) 6 F,
_{_{_{CH 2 = C (CH 3)}}} COOCH 2 (CF 2) 6 F,
_{_{_{CH 2 = CHCOOCH 2 (CF 2}}} ) 7 F,
_{_{_{CH 2 = C (CH 3)}}} COOCH 2 (CF 2) 7 F,
CH ₂ = CHCOOCH ₂ CF ₂ CF ₂ H,
_{_{_{CH 2 = CHCOOCH 2 (CF 2}}} CF 2) 2 H,
_{_{_{CH 2 = CHCOOCH 2 (CF 2}}} CF 2) 4 H,
_{_{_{CH 2 = C (CH 3)}}} COOCH 2 (CF 2 CF 2) H,
_{_{_{CH 2 = C (CH 3)}}} COOCH 2 (CF 2 CF 2) 2 H,
_{_{_{CH 2 = C (CH 3)}}} COOCH 2 (CF 2 CF 2) 4 H,
_{_{_{CH 2 = CHCOOCH 2 CF 2 OCF}}} 2 CF 2 OCF 3,
_{_{_{CH 2 = CHCOOCH 2 CF 2 O}}} (CF 2 CF 2 O) 3 CF 3,
_{_{_{_{CH 2 = C (CH 3)}}}} COOCH 2 CF 2 OCF 2 CF 2 OCF 3,
_{_{_{_{CH 2 = C (CH 3)}}}} COOCH 2 CF 2 O (CF 2 CF 2 O) 3 CF 3,
_{_{_{CH 2 = CHCOOCH 2 CF (CF}}} 3) OCF 2 CF (CF 3) O (CF 2) 3 F,
_{_{_{CH 2 = CHCOOCH 2 CF (CF}}} 3) O (CF 2 CF (CF 3) O) 2 (CF 2) 3 F,
_{_{_{_{CH 2 = C (CH 3)}}}} COOCH 2 CF (CF 3) OCF 2 CF (CF 3) O (CF 2) 3 F,
_{_{_{_{CH 2 = C (CH 3)}}}} COOCH 2 CF (CF 3) O (CF 2 CF (CF 3) O) 2 (CF 2) 3 F,
_{_{_{CH 2 = CFCOOCH 2 CH (OH}}} ) CH 2 (CF 2) 6 CF (CF 3) 2,
_{_{_{CH 2 = CFCOOCH 2 CH (CH}}} 2 OH) CH 2 (CF 2) 6 CF (CF 3) 2,
_{_{_{CH 2 = CFCOOCH 2 CH (OH}}} ) CH 2 (CF 2) 10 F,
_{_{_{CH 2 = CFCOOCH 2 CH (CH}}} 2 OH) CH 2 (CF 2) 10 F , and the like.

As the fluoro (meth) acrylates, a compound (D1) represented by the following formula (D1) is preferable from the viewpoint of compatibility and environmental characteristics.

However, R ¹ represents a hydrogen atom or a methyl group, R ² and R ³ each independently represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and R ⁴ and R ⁵ each independently A fluorine atom, a C 1-4 perfluoroalkyl group or a C 1-4 perfluoroalkoxy group, R ⁶ represents a hydrogen atom or a fluorine atom, and m represents an integer of 1 to 4. , N represents an integer of 1-16.
R ² and R ³ are each independently preferably a hydrogen atom or a methyl group.
R ⁴ and R ⁵ are each independently preferably a fluorine atom or a trifluoromethyl group.
R ⁶ is preferably a fluorine atom.
n is preferably an integer of 1 to 10 from the viewpoint of compatibility, and more preferably an integer of 3 to 6 from the viewpoint of environmental characteristics.
Among the compounds (D1), those in which m is 2 to 3 and n is 4 to 6 are particularly preferable in terms of releasability.

A compound (D) may be used individually by 1 type, and may use 2 or more types together.
The content of the compound (D) is 0.1 to 20% by mass in a total of 100% by mass of the curable components. 1 mass% or more is preferable and 5 mass% or more is more preferable. 15 mass% or less is preferable and 12 mass% or less is more preferable.
If content of a compound (D) is 0.1 mass% or more, the improvement effect of mold release property will fully be acquired. If it is 20 mass% or less, good compatibility with other compounds can be obtained.

[Compound (E)]
The curable composition of the present invention may contain a compound (E) having one (meth) acryloyloxy group other than the compound (D). That is, the compound (E) is a compound having one (meth) acryloyloxy group and having no fluorine atom.
The compound (E) is a component that dissolves other components, contributes to improving the compatibility of the other components, and can also be used to adjust the refractive index.
Examples of the compound (E) include the following mono (meth) acrylates.
Phenoxyethyl (meth) acrylate, phenoxyethylene glycol (meth) acrylate, benzyl (meth) acrylate, methoxytriethylene glycol (meth) acrylate, stearyl (meth) acrylate, lauryl (meth) acrylate, 3- (trimethoxysilyl) propyl (Meth) acrylate, butyl (meth) acrylate, ethoxyethyl (meth) acrylate, glycidyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, N, N-diethylaminoethyl (meth) acrylate, dimethylaminoethyl (meth) Acrylate, 2-methyl-2-adamantyl (meth) acrylate, 3-hydroxy-1-adamantyl (meth) acrylate, 1-adamantyl (meth) acrylate, isovo Sulfonyl (meth) acrylate, beta-carboxyethyl (meth) acrylate, octyl (meth) acrylate, n- butyl (meth) acrylate, 4-tert-butylcyclohexyl (meth) acrylate. Among these, 2-methyl-2-adamantyl (meth) acrylate, phenoxyethylene glycol (meth) acrylate, 1-adamantyl (meth) acrylate, or isobornyl (meth) acrylate is preferable.
A compound (C) may be used individually by 1 type, and may use 2 or more types together.

Further, the unreacted monomer remaining after the synthesis of the compound (B) or the compound (C) corresponds to the compound (E). Such unreacted monomer may be contained in the curable composition as the compound (E).
Content of a compound (E) is 10 mass% or less among the total 100 mass% of a sclerosing | hardenable component, 4 mass% or less is preferable, 1 mass% or less is more preferable, and zero is especially preferable. If content of a compound (E) is 10 mass% or less, there will be little influence on heat resistance.
Further, the total of the compound (D) and the compound (E) is 0.1 to 20% by mass, preferably 1 to 17% by mass, more preferably 1 to 14% by mass, out of the total 100% by mass of the curable components. preferable.

[Compound (F)]
The compound (F) is a compound having a fluorene skeleton and two (meth) acryloyloxy groups. The compound (F) contributes to improvement of heat resistance and contributes to reduction of shrinkage during curing. Moreover, a compound (F) contributes to the improvement of the refractive index of hardened | cured material.
For example, when the curable composition of the present invention is used as a material for an antireflection film formed on a glass article, reflection at these interfaces can be highly prevented if the refractive index difference between the glass and the antireflection film is small. It is possible to improve the performance (oblique incidence characteristic) that does not reflect when light is incident from an oblique direction. The refractive index of glass is often as high as around 1.52. For example, the refractive index of borosilicate glass is 1.51 to 1.53. When the compound (F) is contained in the curable composition, the refractive index of the cured product is increased, so that the difference in refractive index from the glass can be reduced.

Examples of the fluorene skeleton include fluorene (fluorene skeleton having no substituent at the 9-position) and 9-substituted fluorene (for example, fluorene having a hydrocarbon group at the 9-position such as 9,9-bisarylfluorene). Note that the fluorene skeleton may have a substituent in fluorene or a substituent substituted at the 9-position of fluorene.

The substitution position (bonding position) of the group containing the (meth) acryloyloxy group or the (meth) acryloyloxy group with respect to the fluorene skeleton is not particularly limited, and may be bonded to the fluorene skeleton itself, which is the 9th position of the fluorene. It may be bonded to the substituent located.
Examples of the compound (F) include 9,9-bisarylfluorenes having two (meth) acryloyloxy groups), for example, a compound represented by the following formula (F1).

(In the formula, ring Z is an aromatic hydrocarbon ring, R ¹¹ is a substituent, R ¹² is an alkylene group, R ¹³ is a hydrogen atom or a methyl group, R ¹⁴ is a substituent, and k is (An integer of 0 to 4, s is an integer of 0 or more, and t is an integer of 0 or more.)

As the compound represented by the formula (F1), 9,9-bis ((meth) acryloyloxyaryl) fluorenes and 9,9-bis ((meth) acryloyloxy (poly) alkoxyaryl) fluorenes are preferable, 9,9-bis ((meth) acryloyloxy (poly) alkoxyaryl) fluorenes are more preferred.
The 9,9-bis ((meth) acryloyloxy (poly) alkoxyaryl) fluorenes include 9,9-bis ((meth) acryloyloxyalkoxyphenyl) fluorene [for example, 9,9-bis (4- (2 9,9-bis ((meth) acryloyloxy (C2-C4 alkoxy) phenyl) fluorene etc.] such as-(meth) acryloyloxyethoxy) phenyl) fluorene.

A compound (F) may be used individually by 1 type, and may use 2 or more types together.
Content of a compound (F) is 40 mass% or less among 100 mass% of total of a sclerosing | hardenable component, 30 mass% or less is preferable and its 25 mass% or less is more preferable. If content of a compound (F) is 40 mass% or less, a viscosity can fully be lowered | hung and favorable applicability | paintability can be maintained.
In addition, the content of the compound (F) is preferably 5% by mass or more out of a total of 100% by mass of the curable components, in that the effect of improving the heat resistance and the effect of improving the refractive index are sufficiently obtained. More preferably, it is more preferably 15% by mass or more.

[Other curable components]
The curable composition contains other curable components that are not included in any of the above compound (A), compound (B), compound (C), compound (D), compound (E), and compound (F). May be included.
The content of other curable components is 10% by mass or less, preferably 5% by mass or less, and more preferably 3% by mass or less, out of a total of 100% by mass of the curable components.

[Photoinitiator (G)]
As photopolymerization initiator (G), alkylphenone photopolymerization initiator, acylphosphine oxide photopolymerization initiator, titanocene photopolymerization initiator, oxime ester photopolymerization initiator, oxyphenyl acetate photopolymerization initiator Agent, benzoin photopolymerization initiator, benzophenone photopolymerization initiator, thioxanthone photopolymerization initiator, benzyl- (o-ethoxycarbonyl) -α-monooxime, glyoxyester, 3-ketocoumarin, 2-ethylanthraquinone, Examples include camphorquinone, tetramethylthiuram sulfide, azobisisobutyronitrile, benzoyl peroxide, dialkyl peroxide, tert-butylperoxypivalate, and the like. From the viewpoint of sensitivity and compatibility, alkylphenone photopolymerization initiator, acylphosphine Oxide system Polymerization initiator, a benzoin-based photopolymerization initiator or a benzophenone photopolymerization initiator is preferred.

A photoinitiator (G) may be used individually by 1 type, and may use 2 or more types together.
The content of the photopolymerization initiator (G) is 1 to 10 parts by weight, preferably 2 to 7 parts by weight, based on 100 parts by weight of the curable components. If the content of the photopolymerization initiator (G) is not less than the lower limit of the above range, a good cured product can be obtained by irradiating light to the curable composition without performing an operation such as heating. Easy to obtain. If it is below the upper limit of the said range, the fall of the transmittance | permeability by coloring can be prevented.

[Fluorine-containing surfactant (H)]
The fluorine-containing surfactant (H) has the effect of eliminating the bubbles when the curable composition is applied and the effect of improving the releasability of the cured product. Furthermore, there is also an effect of holding the coating film.
As the fluorine-containing surfactant (H), a fluorine-containing surfactant having a fluorine content of 10 to 70% by mass is preferable, and a fluorine-containing surfactant having a fluorine content of 10 to 40% by mass is more preferable. The fluorine-containing surfactant may be water-soluble or fat-soluble, and is preferably fat-soluble from the viewpoint of compatibility in the curable composition and dispersibility in the cured product.

The fluorine-containing surfactant (H) is preferably a nonionic fluorine-containing surfactant from the viewpoints of compatibility in the curable composition and dispersibility in the cured product.
As the nonionic fluorine-containing surfactant, polyfluoroalkylamine oxide or polyfluoroalkyl alkylene oxide adduct is preferable.

Specific examples of the nonionic fluorine-containing surfactant include Surflon S-242, Surflon S-243, Surflon S-386, Surflon S-420, Surflon S-611, Surflon S-650, Surflon S-651, Surflon S -145, Surflon S-393, Surflon KH-20, Surflon KH-40 (above are trade names of AGC Seimi Chemical), Florado FC-170, Florado FC-430 (above are trade names of Sumitomo 3M) , Mega Fuck F-552, Mega Fuck F-553, Mega Fuck F-554, Mega Fuck F-556 (the above is the product name of DIC), and the like.

A fluorine-containing surfactant (H) may be used individually by 1 type, and may use 2 or more types together.
The content of the fluorine-containing surfactant (H) is preferably 0.1 to 10 parts by mass, and more preferably 0.5 to 5 parts by mass with respect to 100 parts by mass as the total of the curable components. If content of a fluorine-containing surfactant (H) is more than the lower limit of the said range, the mold release improvement effect will be fully easy to be acquired. If it is below the upper limit of the said range, inhibition of hardening of a curable composition will be suppressed and the phase separation of hardened | cured material will be easy to be suppressed.

[Additive (I)]
The curable composition may include an additive (I) that is not included in any of the curable component, the photopolymerization initiator (G), the fluorine-containing surfactant (H), and the solvent.
Additives (I) include antioxidants (heat stabilizers), thixotropic agents, antifoaming agents, light-resistant stabilizers, anti-gelling agents, photosensitizers, resins, metal oxide fine particles, carbon compounds, metals Examples thereof include fine particles and other organic compounds.

Antioxidants include pentaerythritol tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate, thiodiethylenebis [3- (3,5-di-tert-butyl-4-hydroxy Phenyl) propionate], trade names of BASF, IRGANOX 1076, IRGANOX 1135, IRGANOX 1035, IRGANOX 1098, IRGANOX 1010, IRGANOX 1520L, trade names of ADEKA, ADK STAB AO-20, ADK STAB AO-30, ADK STAB AO-30, O -50, Adeka stub AO-60, Adeka stub AO-80, Adeka stub AO-330 and the like. By adding an antioxidant, the heat resistance is improved and yellowing is difficult to occur.

One type of additive (I) may be used alone, or two or more types may be used in combination.
The proportion of the additive (I) is preferably 10% by mass or less, more preferably 5% by mass or less, and may be zero in the photocurable composition (100% by mass). When the amount is not more than the upper limit of the above range, the influence on the viscosity is small.

[Function and effect]
In the curable composition of the present invention described above, the compound (A), the compound (B), the compound (C), the compound (D), and the photopolymerization initiator (G) are essential components. Therefore, the composition has a low viscosity, and a cured product obtained by curing the composition has good heat resistance and excellent releasability from the mold.

<Hardened product>
The curable composition of the present invention can be cured by irradiating light to obtain a cured product. The wavelength of light is preferably 200 to 500 nm. Curing may be accelerated by heating when irradiating light.
The temperature of the curable composition when irradiated with light is preferably 0 to 100 ° C, more preferably 10 to 60 ° C.
The light irradiation amount (integrated light amount) can be selected from a range of, for example, about 50 to 20000 mJ / cm ² , preferably 100 to 10000 mJ / cm ² , and more preferably 200 to 8000 mJ / cm ² .

By curing the curable composition of the present invention, as shown in the examples below, the film thickness retention rate during heating is high and heat resistance is high, and the contact angle is high and the mold release property is excellent. Cured product is obtained. A high film thickness maintenance ratio during heating means that there is little film loss due to heating and thermal deformation is small.
Specifically, the film thickness maintenance rate when a 2 μm thick cured film (cured product) obtained by irradiating a coating film made of the curable composition of the present invention with ultraviolet rays is heated at 260 ° C. for 20 minutes. A cured product having excellent heat resistance with a level of 98% or more can be obtained.
The film thickness maintenance rate when the cured film (cured product) is heated at 260 ° C. for 20 minutes is 98% or more, so that thermal deformation hardly occurs even after a reflow process for solder melting. Means having high heat resistance.

The curable composition of the present invention is suitable for producing a cured product having irregularities on the surface by the nanoimprint lithography method because the composition has a low viscosity and good coatability and is excellent in releasability of the cured product. .

As the nanoimprint lithography method, a known method can be used.
For example, it can be performed by the following method (a), (b) or (c) using a mold in which a reverse pattern of a fine pattern to be obtained is formed.
Method (a): First, a curable composition is disposed on the surface of a substrate, and the curable composition is cured by irradiating the curable composition with light in a state where the reversal pattern of the mold is pressed against the curable composition. By separating the mold from the product, a cured product having a target fine pattern on the surface can be obtained.
Examples of the arrangement method of the curable composition include an inkjet method, a potting method (dispensing method), a spin coating method, a roll coating method, a casting method, a dip coating method, a die coating method, a Langmuir projet method, and a vacuum deposition method. It is done. A spin coating method, a roll coating method, or a die coating method is preferable.
The curable composition may be disposed on the entire surface of the substrate or may be disposed on a part of the surface of the substrate.

Method (b): A curable composition is disposed on the surface of the reversal pattern of the mold, and the cured product is cured by irradiating the curable composition with light in a state where the substrate is pressed against the curable composition. By separating the mold from the substrate, a cured product having a target fine pattern on the surface can be obtained.
Method (c): The substrate and the mold are brought close to or in contact with each other so that the reversal pattern of the mold is on the substrate side, the curable composition is filled between them, and the curable composition is irradiated with light. After curing, the mold is separated from the cured product to obtain a cured product having a target fine pattern on the surface of the substrate.

(substrate)
Examples of the substrate include an inorganic material substrate and an organic material substrate.
Inorganic materials include silicon wafer, glass, quartz glass, metal (aluminum, nickel, copper, etc.), metal oxide (sapphire, indium tin oxide (hereinafter referred to as ITO), etc.), silicon nitride, aluminum nitride, niobium Examples include lithium acid. Preferably, it is glass, quartz glass, or sapphire.
Organic materials include fluorine resin, silicone resin, acrylic resin, polycarbonate, polyester (polyethylene terephthalate (hereinafter referred to as PET)), polyamide, polyimide, polypropylene, polyethylene, nylon resin, polyphenylene sulfide, triacetyl cellulose (hereinafter referred to as “polyethylene terephthalate”). , TAC)), cyclic polyolefin and the like. Acrylic resin, polycarbonate, or PET is preferable.

(mold)
Examples of the mold include a non-translucent material mold or a translucent material mold.
Examples of the non-translucent material include a silicon wafer, nickel, copper, stainless steel, titanium, SiC, mica and the like. Preferably, it is a silicon wafer or nickel.
Examples of the light transmitting material include quartz, glass, polydimethylsiloxane, cyclic polyolefin, polycarbonate, polyethylene terephthalate, and transparent fluororesin.
At least one of the substrate and the mold is preferably a material that transmits 40% or more of light having a wavelength on which the photopolymerization initiator (G) acts.

In addition, a mold made of these materials is used as a parent mold, and a child mold (also referred to as a replica mold) having a fine pattern on the surface of the cured resin transferred from the parent mold by a nanoimprint lithography method using a photocurable composition. Can be used as a mold for mass production.
Since the material of the parent mold is relatively expensive, it is preferable to use the child mold because the manufacturing cost can be reduced. In general, the material of the child mold is harder to release than the parent mold, but the curable composition of the present invention is excellent in releasability, so that it can be suitably used for the imprint lithography method using the child mold. it can.

The mold has a reverse pattern on the surface. The reverse pattern is a reverse pattern corresponding to the target fine pattern.
The reverse pattern has fine convex portions and / or concave portions. As a convex part, the elongate protruding item | line extended on the surface of a mold, the processus | protrusion scattered on the surface, etc. are mentioned. Examples of the recess include a long groove extending on the surface of the mold and holes scattered on the surface.

Examples of the shape of the ridge or groove include a straight line, a curved line, a bent shape, and the like. A plurality of ridges or grooves may exist in parallel and have a stripe shape.
Examples of the cross-sectional shape of the ridge or groove in the direction perpendicular to the longitudinal direction include a rectangle, a trapezoid, a triangle, and a semicircle.
Examples of the shape of the protrusion or hole include a triangular prism, a quadrangular prism, a hexagonal prism, a cylinder, a triangular pyramid, a quadrangular pyramid, a hexagonal pyramid, a cone, a hemisphere, and a polyhedron.

The width of the protrusion or groove is preferably 1 nm to 100 μm, more preferably 1 nm to 10 μm, and particularly preferably 10 to 500 nm. The width of the ridge means the length of the base in the cross section in the direction orthogonal to the longitudinal direction. The width of the groove means the length of the upper side in the cross section in the direction orthogonal to the longitudinal direction.

The width of the protrusion or hole is preferably 1 nm to 100 μm, more preferably 1 nm to 10 μm, and particularly preferably 10 to 500 nm. The width of the protrusion means the length of the bottom side in a cross section perpendicular to the longitudinal direction when the bottom surface is elongated, and otherwise means the maximum length of the bottom surface of the protrusion. The width of the hole means the length of the upper side in the cross section perpendicular to the longitudinal direction when the opening is elongated, and otherwise means the maximum length of the opening of the hole.

The height of the convex portion is preferably 1 nm to 100 μm, more preferably 1 nm to 10 μm, still more preferably 10 to 500 nm.
The depth of the recess is preferably 1 nm to 100 μm, more preferably 1 nm to 10 μm, and even more preferably 10 to 500 nm.

By setting the period of the convex part (or concave part) to be equal to or less than the wavelength of visible light, a cured product having an antireflection function is obtained. The period of a convex part means the average value of the distance from the terminal end of the cross section of a convex part to the terminal end of the base of the cross section of an adjacent convex part.
The period of the recess means the average value of the distance from the end of the upper side of the cross section of the recess to the end of the upper side of the cross section of the adjacent recess. Specifically, 50 points are observed with an electron microscope, and the average of these values is taken as the period value.
The period of the convex part (or concave part) is preferably 10 to 1000 nm, more preferably 50 to 500 nm.

<Method for Manufacturing Camera Module / Imaging Device>
In the curable composition of the present invention, since the cured product formed is excellent in heat resistance, for example, in the manufacturing process of an imaging device such as a digital camera, an optical article of a camera module mounted on a printed circuit board by a reflow method, etc. It can be suitably used as a material for articles requiring heat resistance.
For example, as a method for mounting a camera module including a photographic lens and a solid-state imaging device that converts an optical image formed by the photographic lens into an electrical imaging signal, on a printed circuit board terminal portion, A soldering method (solder reflow method) can be used by applying solder and passing through the reflow furnace in a state where the input / output terminals of the camera module are placed on the solder. .
The temperature inside the reflow furnace is 220 to 230 ° C. when the common eutectic solder containing lead is used, and the temperature at the time of melting and heating is 250 to 260 ° C. with lead-free solder. To reach.

For example, an antireflection film provided on a camera module that requires such heat resistance can be produced using the curable composition of the present invention.
For example, a cover glass provided coaxially with the photographic lens is used as a substrate, the curable composition of the present invention is disposed on the surface of the cover glass, and the surface has a concavo-convex shape by a nanoimprint lithography method. By forming a cured product in which the period of the recesses is equal to or less than the wavelength of visible light, a camera module having an antireflection film made of the cured product of the present invention can be obtained.
For example, by forming the antireflection film on a cover glass of a solid-state imaging device such as a CCD (Charge Coupled Device) image sensor or a CMOS (Complementary Metal Oxide Semiconductor) image sensor, a solid-state imaging device having an antireflection film can be obtained. It is done. A solid-state image sensor such as a CCD or CMOS is generally disposed on the inner bottom of a base having a box shape with a bottom without a lid made of ceramic so as not to be affected by the use environment (for example, alpha rays and dust). Used sealed with a cover glass. Quartz, aluminosilicate glass, borosilicate glass, or the like is used as the cover glass. By forming an antireflection film on one side or both sides of these cover glasses, not only light incident perpendicularly to the solid-state imaging device but also light incident obliquely (for example, 45 degrees) can be reflected. Can be prevented.
Since the camera module provided with such an antireflection film has good heat resistance, the antireflection film is prevented from being deformed by heat even after a high temperature process such as solder reflow treatment.
Therefore, in the manufacturing method of the imaging device, the use of the camera module provided with such an antireflection film prevents the performance from being deteriorated due to the solder reflow process.
Examples of the imaging device include a digital camera, a video camera, a mobile phone, a mobile device, and the like.

The present invention will be described below with reference to examples, but the present invention is not limited to these examples. Examples 1 to 9 are examples, and examples 11 to 17 are comparative examples.
[viscosity]
The viscosity at 25 ° C. of the curable composition was measured using a viscometer (manufactured by Toki Sangyo Co., Ltd., TV-20). The viscometer has been calibrated with a standard solution (JS50 (33.17 mPa · s at 25 ° C.)).
The viscosity of the curable composition is preferably 100 mPa · s or less.

[Method for producing cured product]
The curable composition was applied onto a glass substrate by a spin coating method to form a coating film having a thickness of 2 μm. This coating film was irradiated with ultraviolet rays under a nitrogen atmosphere using a high-pressure mercury lamp (manufactured by Toshiba Lighting & Technology Co., Ltd., product name: TOSCURE 1404) so that the integrated light amount was 6000 mJ / cm ² to obtain a cured product.

[Thickness maintenance rate (heat resistance)]
What formed the hardened | cured material on the glass substrate by "the manufacturing method of hardened | cured material" was heated on the hotplate. The heating conditions were 20 minutes at a heating temperature at which the temperature of the glass on which the cured product was formed was 260 ° C. The film thickness of the cured product was measured before and after heating, and the film thickness maintenance ratio (unit:%) was determined by the following formula (I). The larger this value, the less the film loss due to heating, and the better the heat resistance.
Film thickness maintenance ratio = film thickness after heating / film thickness before heating × 100 (I)
The film thickness is measured by removing a part of the cured product formed on the glass substrate and providing a region where the glass substrate is exposed, and a stylus type surface shape measuring instrument (product name: DEKTAK150, manufactured by Veeco). ).

[Contact angle]
About the hardened | cured material manufactured by "the manufacturing method of hardened | cured material", the water contact angle was measured according to the sessile drop method of JISR3257. Specifically, 1 μL of water was deposited on the surface of the cured product, and the water contact angle was measured using a contact angle meter (product name: CA-X150 type, manufactured by Kyowa Interface Science Co., Ltd.).
The contact angle is a measure of the releasability of the cured product. The larger the contact angle value, the better the releasability. The contact angle is preferably 75 degrees or more, and more preferably 80 degrees or more.

[Releasability]
The curable composition was applied onto a glass substrate by a spin coating method to form a coating film having a thickness of 2 μm. Using this same high pressure mercury lamp from the glass substrate side with a resin mold prepared in advance pressed at 0.5 MPa (gauge pressure) on this coating film by the following method, the integrated light quantity is 6000 mJ / A cured product was obtained by irradiating cm ² ultraviolet rays.
When the resin mold is peeled from the cured product, a cured product having a convex structure on the surface, which is a reverse of the concave structure of the resin mold, is formed on the glass substrate.
The case where there was no adhesion of the curable composition to the peeled resin mold was determined to be acceptable (◯), and the case where adhesion was observed was determined to be unacceptable (x).

The resin mold was manufactured by the following method. That is, a UV curable resin ((Hitachi Chemical Co., Ltd .: Hitaroid HA7981F47) was dropped onto the PET film and spin-coated to obtain a PET film uniformly coated with the UV curable resin.
A state in which a Ni mold (parent mold) having a plurality of concavo-convex structures (a moth-eye structure with a recess depth of 250 nm and a recess period of 350 nm) on the surface is pressed against an ultraviolet curable resin on a PET film at 0.5 MPa (gauge pressure) Then, from the PET film side, the same high pressure mercury lamp as above was used to cure by irradiating with an ultraviolet ray having an integrated light quantity of 2000 mJ / cm ² . The Ni mold was peeled from the cured product (resin mold) on the PET film to obtain a resin mold (child mold) having a concave structure on the surface in which the convex structure of the Ni mold was inverted.

[Refractive index]
A curable composition is applied onto a glass substrate by a spin coating method, and ultraviolet light is applied to the coating film under a nitrogen atmosphere using the same high-pressure mercury lamp as described above so that the integrated light amount becomes 6000 mJ / cm ^2. Was irradiated to obtain a cured product. About the obtained hardened | cured material, the refractive index in wavelength 589nm was measured at 25 degreeC using the Abbe refractive index measuring apparatus (The product made from ATAGO, product name: 2T type).

[Compound (A)]
Compound (A-1): 1,6-hexanediol diacrylate, manufactured by Shin-Nakamura Chemical Co., Ltd., A-HD-N (product name).
Compound (A-2): 1,9-nonanediol diacrylate, manufactured by Shin-Nakamura Chemical Co., Ltd., A-NOD (product name).
Compound (A-3): 1,10-decanediol diacrylate, manufactured by Shin-Nakamura Chemical Co., Ltd., A-DOD-N (product name).
Compound (A-4): Neopentyl glycol diacrylate, manufactured by Kyoeisha Chemical Co., Ltd., NP-A (product name).
Compound (A-5): 3-methyl-1,5-pentanediol diacrylate, manufactured by Kyoeisha Chemical Co., Ltd., MPD-A (product name).

[Compounds (B) and (C)]
Commercial product containing compound (B-1) and compound (C-1): A-TMM-3LM-N (product name, pentaerythritol triacrylate (compound (B-1)), manufactured by Shin-Nakamura Chemical Co., Ltd.) % And a mixture of 42% by mass of pentaerythritol tetraacrylate (compound (C-1)).
Compound (C-1): Pentaerythritol tetraacrylate, manufactured by Nakamura Chemical Co., Ltd., A-TMMT (product name).

[Compound (D)]
Compound (D-1): perfluorohexyl ethyl methacrylate, manufactured by Asahi Glass Co., Ltd., C6FMA (product name).
[Compound (E)]
Compound (E-1): Lauryl acrylate, manufactured by Kyoeisha Chemical Co., Ltd., light acrylate LA (product name).
Compound (E-2): Methoxy-polyethylene glycol acrylate, manufactured by Kyoeisha Chemical Co., Ltd., Light Acrylate 130A (product name, average number of repeating —C ₂ H ₄ O— is 9).
Compound (E-3): Isobornyl acrylate, manufactured by Kyoeisha Chemical Co., Ltd., IB-XA (product name).

[Compound (F)]
Compound (F-1): 9,9-bis [4- (2-acryloyloxyethoxy) phenyl] fluorene, manufactured by Shin-Nakamura Chemical Co., Ltd., A-BPEF (product name).
[Comparative Compound (Z)]
Compound (Z-1): Polyethylene glycol diacrylate, manufactured by Shin-Nakamura Chemical Co., Ltd., A-BPEF (product name, —C ₂ H ₄ O— average repeat number is 4).
Compound (Z-2): Dipropylene glycol diacrylate, manufactured by Shin-Nakamura Chemical Co., Ltd., A-BPEF (product name, average repeat number m of —CH (CH ₃ ) CH ₂ O—, —CH ₂ CH (CH ₃ ) Average number of repetitions of O−, m + n = 2).

[Photoinitiator (G)]
Photopolymerization initiator (G-1): manufactured by BASF, Irgagua 907 (product name), 2-methyl-1- (4-methylthiophenyl) -2-morpholinopropan-1-one.
[Fluorine-containing surfactant (H)]
Fluorine-containing surfactant (H-1): Nonionic fluorine-containing surfactant, manufactured by AGC Seimi Chemical Co., Surflon S-386.

[Examples 1 to 9, 11 to 17]
Each compound, photopolymerization initiator (G), and fluorine-containing surfactant (H) were mixed at 25 ° C. for 5 hours using a mix rotor in the formulations shown in Tables 1 to 3 (unit: parts by mass). Thus, a curable composition was prepared.
The viscosity of the obtained curable composition was measured by the above method.
Hardened | cured material was manufactured by said method and the film thickness maintenance factor (heat resistance), the contact angle, and the mold release property were evaluated.
When the refractive index of the hardened | cured material of the curable composition obtained in Example 2 and Example 9 was measured by said method, Example 2 was 1.5241 and Example 9 was 1.5072.
These results are shown in Tables 1 to 3.

As shown in Table 1, Examples 1 to 5 are examples containing compounds (A), (B), (C), (D), and (F) but not (E). The viscosity of the curable composition is low, the film thickness retention rate of the cured product is high, the heat resistance is excellent, the contact angle is high, and the mold release property is excellent.
Examples 11 to 15 do not use compound (A) in Examples 1 to 5, but instead have compound (E) having one (meth) acryloyloxy group, or two (meth) acryloyloxy groups This is a comparative example containing a comparative compound (Z) which is a glycol.
In Examples 11 to 15, the film thickness retention rate of the cured product is low and the heat resistance is inferior to Examples 1 to 5. Particularly in Examples 13 to 15 in which the compound (E) was used in place of the compound (A), the film thickness maintenance rate was remarkably low.

Example 6 is an example in which the content of the compound (A) in Example 2 was reduced and the compound (E) was newly added. In Example 6, the viscosity of the curable composition is low, the film thickness retention rate of the cured product is high, the heat resistance is excellent, the contact angle is high, and the mold release property is excellent.

Examples 7 and 8 in Table 2 are examples in which the content of the compound (D) was reduced in Example 2. Although the value of the contact angle was somewhat low, the viscosity of the curable composition was low, the film thickness retention rate of the cured product was high, the heat resistance was excellent, and good release properties were obtained.
Example 16 is a comparative example in which compound (D) was not used in Example 2. The value of the contact angle is remarkably low and the releasability is poor.
Example 17 is a comparative example in which compound (A) and compound (D) were not used in Example 2. The viscosity of the curable composition is remarkably high, the value of the contact angle is remarkably low, and the releasability is poor.

As shown in Table 3, Example 9 is an example in which the content of compound (B) and compound (C) was increased in Example 2 without using compound (F). In Example 9, the refractive index of the cured product was lower than that in Example 2.
From these results, it can be seen that the refractive index of the cured product can be increased by using the compound (F).

The cured product obtained from the curable composition of the present invention is useful as a material for articles that require heat resistance, and is an imaging device equipped with an optical component such as a camera module. It can be used for telephones and mobile devices.
It should be noted that the entire contents of the specification, claims and abstract of Japanese Patent Application No. 2013-240907 filed on November 21, 2013 are incorporated herein as the disclosure of the specification of the present invention. Is.

Claims

The following compound (A) 20 to 80% by mass, the following compound (B) 5 to 50% by mass, the following compound (C) 5 to 50% by mass, the following compound (D) 0.1 to 20% by mass, It contains a curable component containing 0 to 10% by mass of the following compound (E) and 0 to 40% by mass of the following compound (F), and the total of the compound (D) and the compound (E) is 0.1 to 20% by mass. % Curable composition.
Compound (A): A compound having (meth) acryloyloxy groups at both ends of an alkylene group.
Compound (B): A compound having three (meth) acryloyloxy groups.
Compound (C): A compound having four (meth) acryloyloxy groups.
Compound (D): A compound having at least one (meth) acryloyloxy group and containing a fluorine atom.
Compound (E): Compound having one (meth) acryloyloxy group (excluding compound (D)).
Compound (F): A compound having a fluorene skeleton and two (meth) acryloyloxy groups.
The curable composition according to claim 1, further comprising 1 to 10 parts by mass of the photopolymerization initiator (G) with respect to 100 parts by mass of the curable component.
The photopolymerization initiator (G) is an alkylphenone photopolymerization initiator, an acylphosphine oxide photopolymerization initiator, a benzoin photopolymerization initiator, or a benzophenone photopolymerization initiator according to claim 1 or 2. Curable composition.
A curable composition containing the following compound (A), the following compound (B), the following compound (C), and the following compound (D), and a photopolymerization initiator (G). And
A curable composition having a film thickness maintenance ratio of 98% or more when a 2 μm-thick cured film obtained by irradiating the coating film comprising the curable composition with ultraviolet rays is heated at 260 ° C. for 20 minutes. .
Compound (A): A compound having (meth) acryloyloxy groups at both ends of an alkylene group.
Compound (B): A compound having three (meth) acryloyloxy groups.
Compound (C): A compound having four (meth) acryloyloxy groups.
Compound (D): A compound having at least one (meth) acryloyloxy group and containing a fluorine atom.
The curable composition according to claim 4, wherein the curable component further comprises the following compound (E) and / or the following compound (F).
Compound (E): Compound having one (meth) acryloyloxy group (excluding compound (D)).
Compound (F): A compound having a fluorene skeleton and two (meth) acryloyloxy groups.
The curable composition according to any one of claims 1 to 5, wherein the viscosity at 25 ° C is 100 mPa · s or less.
A cured product of the curable composition according to any one of claims 1 to 6.
The cured product according to claim 7, wherein the surface has an uneven structure.
The hardened | cured material of Claim 8 whose period of a convex part or a recessed part is below the wavelength of visible light.
The cured product according to claim 9, which is an antireflection film for a camera module.
The cured product according to claim 10, which is an antireflection film formed on the surface of the cover glass on the solid-state imaging device.
A camera module comprising an antireflection film made of the cured product according to claim 9.
Manufacturing a camera module including a photographic lens and a solid-state imaging device that converts an optical image formed by the photographic lens into an electrical imaging signal;
A method of manufacturing an imaging apparatus including a step of mounting the camera module on a printed circuit board by a solder reflow method,
The step of manufacturing the camera module includes disposing the curable composition according to any one of claims 1 to 6 on a surface of a cover glass of a solid-state imaging device, and having an uneven shape on the surface by a nanoimprint lithography method. A method for manufacturing an imaging device, including a step of forming an antireflection film.