JPWO2014119424A1 - Curable composition for wafer level lens, method for producing wafer level lens, wafer level lens, and optical apparatus - Google Patents

Abstract

It is an object of the present invention to suppress problems such as cracking, deformation, and misalignment in a wafer level lens molding process, and to efficiently obtain a wafer level lens excellent in physical characteristics, optical characteristics, and mechanical characteristics. An object of the present invention is to provide a curable composition for a wafer level lens. The curable composition for wafer level lenses of this invention is characterized by including the curable compound (A) represented by following formula (1). In formula (1), X 1 and X 2 are the same or different and each represents a sulfur atom or an oxygen atom. Y1 and Y2 are the same or different and each represents a sulfur atom or an oxygen atom. R1 represents a methylene group, a sulfur atom, or an oxygen atom in which one or two hydrogen atoms may be substituted with an alkyl group having 1 to 5 carbon atoms. R2 and R3 are the same or different and each represents an alkylene group. R4 and R5 are the same or different and each represents a hydrogen atom or a methyl group. m and n are the same or different and represent an integer of 0 or more. However, m + n is an integer of 1 or more. [Chemical 1]

Description

  The present invention relates to a curable composition suitable for molding a wafer level lens (a curable composition for a wafer level lens), a method for producing a wafer level lens using the curable composition for a wafer level lens, and the method. The present invention relates to a wafer level lens and an optical apparatus. This application claims the priority of Japanese Patent Application No. 2013-017819 for which it applied to Japan on January 31, 2013, and uses the content here.

  Radical curable compositions are used in mechanical component materials, electrical / electronic component materials, automotive component materials, civil engineering and building materials, molding materials, paints, adhesives, sealants, etc. It attracts attention as a material for optical members.

  In recent years, electronic products typified by mobile phones, mobile computers, personal digital assistants (PDAs), digital still cameras (DSC), and the like have been dramatically reduced in size, weight, and performance. Along with these market trends, there is a strong demand for miniaturization, thinning, and weight reduction of camera lenses mounted on electronic products, and wafer level lenses have come to be used. Furthermore, in terms of performance enhancement, at least a resolution corresponding to an image sensor of about 8 to 10 million pixels is required, and a cemented lens (laminated wafer level lens) in which two or more lenses are laminated is used. Is done.

  Here, since the refractive index of a lens generally differs depending on the wavelength of light, a phenomenon (chromatic aberration) in which an image is shifted (bleeding or blurring) occurs. In order to reduce the influence of this chromatic aberration, a normal lens has a structure in which a high Abbe number lens and a low Abbe number lens are combined to correct chromatic aberration. As for glass of a lens used for a camera, generally, a glass having an Abbe number of 50 or less is called flint glass, and a glass having a Abbe number of 50 or more is called crown glass.

  As a curable composition for forming a low Abbe number lens, a curable composition mainly composed of a (meth) acrylic acid ester having a fluorene ring is known (Patent Document 1). However, a lens formed from a curable composition mainly composed of a (meth) acrylic acid ester having a fluorene ring exhibits a high storage elastic modulus in a low temperature environment, but rapidly exhibits a storage elastic modulus in a high temperature environment. It has been a problem to cause a decrease in shape and a significant decrease in light transmittance.

Molding of a wafer level lens generally includes the following steps 1 to 3.
Step 1: Pour the curable composition into a mold Step 2: Cure by heating and / or light irradiation Step 3: Remove from the mold and perform annealing treatment

  As described above, in the molding of the wafer level lens by the mold, the curable composition is compression molded in the mold, and the heat treatment and / or the light irradiation treatment are performed in that state. Therefore, stress remains in the cured product (molded product) taken out from the mold, causing distortion, cracking, deformation, etc. Especially in the production of a laminated wafer level lens, there is a displacement (position displacement) of the center position of each lens. There was a problem that occurred.

  On the other hand, in order to relieve the stress remaining in the molded cured product, annealing is performed after taking out from the mold. However, even if the annealing treatment is performed, the stress cannot be sufficiently relaxed, and it is difficult to solve problems such as distortion, cracking and deformation. In addition, if annealing is applied, the lens shape will “sag” and the center position of the lens will shift, causing problems such as blurring of the image on the wafer-level cemented lens obtained by stacking multiple lenses. However, there has been a problem that the yield decreases.

  For this reason, it is possible to suppress problems such as cracking, deformation, and misalignment in the wafer level lens molding process, and it is possible to efficiently obtain a wafer level lens excellent in physical characteristics, optical characteristics, and mechanical characteristics. At present, a curable composition (a curable composition for a wafer level lens) has not yet been obtained.

JP 2009-235196 A

Accordingly, an object of the present invention is to efficiently suppress a wafer level lens having excellent physical characteristics, optical characteristics, and mechanical characteristics, which can suppress problems such as cracking, deformation, and positional deviation in the wafer level lens molding process. An object of the present invention is to provide a curable composition for a wafer level lens.
Another object of the present invention is to provide a method for producing a wafer level lens using the above curable composition for a wafer level lens, and excellent physical properties, optical properties, mechanical properties, and productivity obtained by the method. Another object of the present invention is to provide a wafer level lens and an optical device including the wafer level lens.

  As a result of intensive studies to solve the above problems, the present inventors have found that a curable compound having a specific structure (having two each of an aromatic ring and a (meth) acryloyl group, having at least an oxyalkylene structure or a thioalkylene structure. When a curable composition containing a compound having a compound) as an essential component is used, problems such as cracking, deformation and misalignment in a wafer level lens molding process are suppressed, and a wafer level lens excellent in physical properties, optical properties, and mechanical properties. Has been found to be efficiently obtained, and the present invention has been completed.

［式（１）中、Ｘ¹、Ｘ²は、同一又は異なって、硫黄原子又は酸素原子を示す。Ｙ¹、Ｙ²は、同一又は異なって、硫黄原子又は酸素原子を示す。Ｒ¹は、水素原子の１個若しくは２個が炭素数１〜５のアルキル基で置換されていてもよいメチレン基、硫黄原子、又は酸素原子を示す。Ｒ²、Ｒ³は、同一又は異なって、アルキレン基を示す。Ｒ⁴、Ｒ⁵は、同一又は異なって、水素原子又はメチル基を示す。ｍ、ｎは、同一又は異なって、０以上の整数を示す。但し、ｍ＋ｎは１以上の整数である。］That is, this invention provides the curable composition for wafer level lenses containing the curable compound (A) represented by following formula (1).

[In Formula (1), X < ¹ >, X < ² > is the same or different and shows a sulfur atom or an oxygen atom. Y ¹ and Y ² are the same or different and each represents a sulfur atom or an oxygen atom. R ¹ represents a methylene group, a sulfur atom, or an oxygen atom in which one or two hydrogen atoms may be substituted with an alkyl group having 1 to 5 carbon atoms. R ² and R ³ are the same or different and each represents an alkylene group. R ⁴ and R ⁵ are the same or different and each represents a hydrogen atom or a methyl group. m and n are the same or different and represent an integer of 0 or more. However, m + n is an integer of 1 or more. ]

［式（２）中、Ｒ¹¹は、水素原子の１個若しくは２個が炭素数１〜５のアルキル基で置換されていてもよいメチレン基、硫黄原子、又は酸素原子を示す。Ｒ¹²、Ｒ¹³は、同一又は異なって、水素原子又はメチル基を示す。Ｘ¹¹、Ｘ¹²は、同一又は異なって、硫黄原子又は酸素原子を示す。］Furthermore, the said curable composition for wafer level lenses containing the sclerosing | hardenable compound (B) represented by following formula (2) is provided.

[In Formula (2), R ¹¹ represents a methylene group, a sulfur atom, or an oxygen atom in which one or two hydrogen atoms may be substituted with an alkyl group having 1 to 5 carbon atoms. R ¹² and R ¹³ are the same or different and each represents a hydrogen atom or a methyl group. X ¹¹ and X ¹² are the same or different and each represents a sulfur atom or an oxygen atom. ]

［式（３）中、環Ｚ¹、環Ｚ²は、同一又は異なって、芳香族炭素環を示す。Ｒ¹⁴、Ｒ¹⁶は、同一又は異なって、炭素数１〜１０のアルキレン基を示す。Ｒ¹⁵、Ｒ¹⁷は、同一又は異なって、水素原子又はメチル基を示す。ｐ１、ｐ２は、同一又は異なって、０以上の整数を示す。］Furthermore, the said curable composition for wafer level lenses containing the sclerosing | hardenable compound (C) represented by following formula (3) is provided.

[In Formula (3), Ring Z ¹ and Ring Z ² are the same or different and represent an aromatic carbocyclic ring. R ¹⁴ and R ¹⁶ are the same or different and each represents an alkylene group having 1 to 10 carbon atoms. R ¹⁵ and R ¹⁷ are the same or different and each represents a hydrogen atom or a methyl group. p1 and p2 are the same or different and represent an integer of 0 or more. ]

Further, the curable compound (A) includes at least one compound selected from the following formulas (a1) to (a10) [in formulas (a1) to (a10), m and n are as defined above]: A curable composition for a wafer level lens is provided.

Furthermore, the said curable composition for wafer level lenses containing the at least 1 compound selected from following formula (b1)-(b12) as a sclerosing | hardenable compound (B) is provided.

Furthermore, the said curable composition for wafer level lenses whose storage elastic modulus in 160 degreeC of the hardened | cured material obtained by heating at 150 degreeC for 30 minutes is 0.1 * 10 < ⁹ > Pa or more is provided.

  Furthermore, the said curable composition for wafer level lenses which contains 0.05-10 weight part of organic sulfur compounds as a yellowing inhibitor with respect to 100 weight part of whole quantity of a radical curable compound is provided.

  Furthermore, the said curable composition for wafer level lenses which contains 0.05-5 weight part of hardening retarders with respect to 100 weight part of whole quantity of a radical curable compound is provided.

  Moreover, this invention provides the manufacturing method of the wafer level lens characterized by attaching | subjecting the said curable composition for wafer level lenses to the casting molding method or the injection molding method.

Furthermore, the casting molding method provides the method for manufacturing the wafer level lens including the following steps.
Step 1a: Step of preparing a wafer level lens molding die having one or more lens molds Step 2a: Contacting a curable composition for wafer level lenses with the wafer level lens molding step Step 3a: Wafer level The step of curing the curable composition for lenses by heating and / or light irradiation

Furthermore, the casting molding method further provides the method for producing the wafer level lens further including the following steps.
Step 4a: A step of annealing the cured curable composition for a wafer level lens

Furthermore, the casting molding method further provides the method for producing the wafer level lens further including the following steps.
Step 5a: Cutting the cured curable composition for a wafer level lens

Furthermore, the said injection molding method provides the manufacturing method of the said wafer level lens including the following process.
Step 1b: Step of preparing a wafer level lens molding die having one or more lens molds Step 2b: Step of injecting a curable composition for wafer level lenses onto the wafer level lens molding die Step 3b: Wafer level The step of curing the curable composition for lenses by heating and / or light irradiation

Furthermore, the said injection molding method provides the manufacturing method of the said wafer level lens further including the following process.
Step 4b: A step of annealing the cured curable composition for a wafer level lens

  Moreover, this invention provides the wafer level lens sheet obtained by the manufacturing method of the said wafer level lens.

  Moreover, this invention provides the wafer level lens obtained by the manufacturing method of the said wafer level lens.

  The present invention also provides an optical device equipped with the wafer level lens.

  The present invention is also a laminate of a plurality of wafer level lenses, and is obtained by curing and molding the above curable composition for wafer level lenses as a wafer level lens constituting the laminate. A laminated wafer level lens is provided.

Moreover, this invention is a manufacturing method of the said laminated wafer level lens, Comprising: The manufacturing method of the laminated wafer level lens including the following process is provided.
Step 1c: Step of preparing a wafer level lens molding die having one or more lens molds Step 2c: Contacting the wafer level lens curable composition with the wafer level lens molding die Step 3c: A step of obtaining a wafer level lens sheet by curing the curable composition for wafer level lens by heating and / or light irradiation Step 4c: A wafer level lens obtained by laminating a plurality of wafer level lens sheets including the wafer level lens sheet. Step of obtaining a sheet laminate Step 5c: Step of cutting the wafer level lens sheet laminate

Furthermore, the manufacturing method of the said laminated wafer level lens including the following process between the process 3c and the process 4c is provided.
Step 6c: A step of annealing the wafer level lens sheet

  The present invention also provides a wafer level lens sheet laminate obtained by laminating a plurality of wafer level lens sheets including the wafer level lens sheet.

  The present invention also provides an optical device on which the laminated wafer level lens is mounted.

［式（１）中、Ｘ¹、Ｘ²は、同一又は異なって、硫黄原子又は酸素原子を示す。Ｙ¹、Ｙ²は、同一又は異なって、硫黄原子又は酸素原子を示す。Ｒ¹は、水素原子の１個若しくは２個が炭素数１〜５のアルキル基で置換されていてもよいメチレン基、硫黄原子、又は酸素原子を示す。Ｒ²、Ｒ³は、同一又は異なって、アルキレン基を示す。Ｒ⁴、Ｒ⁵は、同一又は異なって、水素原子又はメチル基を示す。ｍ、ｎは、同一又は異なって、０以上の整数を示す。但し、ｍ＋ｎは１以上の整数である。］
［２］さらに、下記式（２）で表される硬化性化合物（Ｂ）を含有する［１］に記載のウェハレベルレンズ用硬化性組成物。

［式（２）中、Ｒ¹¹は、水素原子の１個若しくは２個が炭素数１〜５のアルキル基で置換されていてもよいメチレン基、硫黄原子、又は酸素原子を示す。Ｒ¹²、Ｒ¹³は、同一又は異なって、水素原子又はメチル基を示す。Ｘ¹¹、Ｘ¹²は、同一又は異なって、硫黄原子又は酸素原子を示す。］
［３］さらに、下記式（３）で表される硬化性化合物（Ｃ）を含有する［１］又は［２］に記載のウェハレベルレンズ用硬化性組成物。

［式（３）中、環Ｚ¹、環Ｚ²は、同一又は異なって、芳香族炭素環を示す。Ｒ¹⁴、Ｒ¹⁶は、同一又は異なって、炭素数１〜１０のアルキレン基を示す。Ｒ¹⁵、Ｒ¹⁷は、同一又は異なって、水素原子又はメチル基を示す。ｐ１、ｐ２は、同一又は異なって、０以上の整数を示す。］
［４］硬化性化合物（Ａ）として、下記式（ａ１）〜（ａ１０）［式（ａ１）〜（ａ１０）中、ｍ、ｎは前記に同じ］から選択される少なくとも１つの化合物を含む［１］〜［３］のいずれか１つに記載のウェハレベルレンズ用硬化性組成物。

［５］硬化性化合物（Ｂ）として、下記式（ｂ１）〜（ｂ１２）から選択される少なくとも１つの化合物を含む［２］〜［４］のいずれか１つに記載のウェハレベルレンズ用硬化性組成物。

［６］硬化性化合物（Ｃ）として、下記式（ｃ１）及び（ｃ２）から選択される少なくとも１つの化合物を含む［３］〜［５］のいずれか１つに記載のウェハレベルレンズ用硬化性組成物。

［７］硬化性化合物（Ａ）の含有量が、硬化性組成物の全量（１００重量％）に対して、２〜５０重量％である［１］〜［６］のいずれか１つに記載のウェハレベルレンズ用硬化性組成物。
［８］硬化性化合物（Ｂ）の含有量が、硬化性組成物に含まれるラジカル硬化性化合物の全量（１００重量％）に対して、１０重量％以上である［２］〜［７］のいずれか１つに記載のウェハレベルレンズ用硬化性組成物。
［９］硬化性化合物（Ｃ）の含有量が、硬化性組成物に含まれるラジカル硬化性化合物の全量（１００重量％）に対して、１０〜７５重量％である［３］〜［８］のいずれか１つに記載のウェハレベルレンズ用硬化性組成物。
［１０］硬化性化合物（Ｂ）と硬化性化合物（Ｃ）の配合比（前者／後者（重量比））が、１／０．２〜１／４である［３］〜［９］のいずれか１つに記載のウェハレベルレンズ用硬化性組成物。
［１１］さらに、３官能以上の（メタ）アクリル酸エステルを含む［１］〜［１０］のいずれか１つに記載のウェハレベルレンズ用硬化性組成物。
［１２］ラジカル硬化性化合物の全量（１００重量％）に対する３官能以上の（メタ）アクリル酸エステルの含有割合が、４５重量％以下である［１１］に記載のウェハレベルレンズ用硬化性組成物。
［１３］分子内に脂環を有する（メタ）アクリル酸エステルを含む［１］〜［１２］のいずれか１つに記載のウェハレベルレンズ用硬化性組成物。
［１４］１５０℃で３０分間加熱して得られる硬化物の１６０℃における貯蔵弾性率が０．１×１０⁹Ｐａ以上である［１］〜［１３］のいずれか１つに記載のウェハレベルレンズ用硬化性組成物。
［１５］さらに、黄変抑制剤として有機硫黄化合物を、ラジカル硬化性化合物の全量１００重量部に対して０．０５〜１０重量部含有する［１］〜［１４］のいずれか１つに記載のウェハレベルレンズ用硬化性組成物。
［１６］有機硫黄化合物が、常圧での沸点が１００℃以上の有機硫黄化合物である［１５］に記載のウェハレベルレンズ用硬化性組成物。
［１７］さらに、硬化遅延剤を、ラジカル硬化性化合物の全量１００重量部に対して０．０５〜５重量部含有する［１］〜［１６］のいずれか１つに記載のウェハレベルレンズ用硬化性組成物。
［１８］硬化遅延剤が、α−メチルスチレン二量体である［１７］に記載のウェハレベルレンズ用硬化性組成物。
［１９］さらに、黄変抑制剤として酸化防止剤を、硬化性組成物に含まれるラジカル硬化性化合物の全量１００重量部に対して０．０５〜５重量部含有する［１５］〜［１８］のいずれか１つに記載のウェハレベルレンズ用硬化性組成物。
［２０］硬化性組成物の全量（１００重量％）に対する酸化防止剤の含有量が０．０５〜５重量％である［１９］に記載のウェハレベルレンズ用硬化性組成物。
［２１］さらに、ラジカル重合開始剤を含み、該ラジカル重合開始剤の含有量が、硬化性組成物に含まれるラジカル硬化性化合物の全量１００重量部に対して、０．０５〜１０重量部である［１］〜［２０］のいずれか１つに記載のウェハレベルレンズ用硬化性組成物。
［２２］硬化させることにより得られる硬化物の４００ｎｍにおける内部透過率が４０％以上である［１］〜［２１］のいずれか１つに記載のウェハレベルレンズ用硬化性組成物。
［２３］硬化させることにより得られる硬化物の屈折率（２５℃、５８９ｎｍ）が１．５８以上である［１］〜［２２］のいずれか１つに記載のウェハレベルレンズ用硬化性組成物。
［２４］硬化させることにより得られる硬化物のアッベ数が３５以下である［１］〜［２３］のいずれか１つに記載のウェハレベルレンズ用硬化性組成物。
［２５］［１］〜［２４］のいずれか１つに記載のウェハレベルレンズ用硬化性組成物をキャスティング成型法又は射出成型法に付すことを特徴とするウェハレベルレンズの製造方法。
［２６］前記キャスティング成型法が、下記工程を含む［２５］に記載のウェハレベルレンズの製造方法。
工程１ａ：１つ以上のレンズ型を有するウェハレベルレンズ成型用型を準備する工程
工程２ａ：ウェハレベルレンズ用硬化性組成物を前記ウェハレベルレンズ成型用型に接触させる工程
工程３ａ：前記ウェハレベルレンズ用硬化性組成物を加熱及び／又は光照射により硬化させる工程
［２７］前記キャスティング成型法が、さらに下記工程を含む［２６］に記載のウェハレベルレンズの製造方法。
工程４ａ：硬化したウェハレベルレンズ用硬化性組成物をアニール処理する工程
［２８］前記キャスティング成型法が、さらに下記工程を含む［２６］又は［２７］に記載のウェハレベルレンズの製造方法。
工程５ａ：硬化したウェハレベルレンズ用硬化性組成物を切断する工程
［２９］前記射出成型法が、下記工程を含む［２５］に記載のウェハレベルレンズの製造方法。
工程１ｂ：１つ以上のレンズ型を有するウェハレベルレンズ成型用型を準備する工程
工程２ｂ：ウェハレベルレンズ用硬化性組成物を前記ウェハレベルレンズ成型用型に射出する工程
工程３ｂ：前記ウェハレベルレンズ用硬化性組成物を加熱及び／又は光照射により硬化させる工程
［３０］前記射出成型法が、さらに下記工程を含む［２９］に記載のウェハレベルレンズの製造方法。
工程４ｂ：硬化したウェハレベルレンズ用硬化性組成物をアニール処理する工程
［３１］［２６］又は［２７］に記載のウェハレベルレンズの製造方法により得られるウェハレベルレンズシート。
［３２］［２５］〜［３０］のいずれか１つに記載のウェハレベルレンズの製造方法により得られるウェハレベルレンズ。
［３３］レンズ中心位置のズレが±２μｍ以下である［３２］に記載のウェハレベルレンズ。
［３４］［３２］又は［３３］に記載のウェハレベルレンズを搭載した光学装置。
［３５］複数枚のウェハレベルレンズの積層体であって、該積層体を構成するウェハレベルレンズとして［１］〜［２４］のいずれか１つに記載のウェハレベルレンズ用硬化性組成物を硬化かつ成型して得られるウェハレベルレンズを少なくとも有する積層ウェハレベルレンズ。
［３６］構成するウェハレベルレンズの枚数が２〜５枚である［３５］に記載の積層ウェハレベルレンズ。
［３７］［３５］又は［３６］に記載の積層ウェハレベルレンズの製造方法であって、下記工程を含む積層ウェハレベルレンズの製造方法。
工程１ｃ：１つ以上のレンズ型を有するウェハレベルレンズ成型用型を準備する工程
工程２ｃ：［１］〜［２４］のいずれか１つに記載のウェハレベルレンズ用硬化性組成物を前記ウェハレベルレンズ成型用型に接触させる工程
工程３ｃ：前記ウェハレベルレンズ用硬化性組成物を加熱及び／又は光照射により硬化させてウェハレベルレンズシートを得る工程
工程４ｃ：前記ウェハレベルレンズシートを含む複数枚のウェハレベルレンズシートを積層してウェハレベルレンズシート積層体を得る工程
工程５ｃ：前記ウェハレベルレンズシート積層体を切断する工程
［３８］さらに、工程３ｃと工程４ｃの間に、下記工程を含む［３７］に記載の積層ウェハレベルレンズの製造方法。
工程６ｃ：前記ウェハレベルレンズシートをアニール処理する工程
［３９］［３１］に記載のウェハレベルレンズシートを含む複数枚のウェハレベルレンズシートを積層して得られるウェハレベルレンズシート積層体。
［４０］［３５］又は［３６］に記載の積層ウェハレベルレンズを搭載した光学装置。That is, the present invention relates to the following.
[1] A curable composition for a wafer level lens, comprising a curable compound (A) represented by the following formula (1).

[In Formula (1), X < ¹ >, X < ² > is the same or different and shows a sulfur atom or an oxygen atom. Y ¹ and Y ² are the same or different and each represents a sulfur atom or an oxygen atom. R ¹ represents a methylene group, a sulfur atom, or an oxygen atom in which one or two hydrogen atoms may be substituted with an alkyl group having 1 to 5 carbon atoms. R ² and R ³ are the same or different and each represents an alkylene group. R ⁴ and R ⁵ are the same or different and each represents a hydrogen atom or a methyl group. m and n are the same or different and represent an integer of 0 or more. However, m + n is an integer of 1 or more. ]
[2] The curable composition for wafer level lenses according to [1], further comprising a curable compound (B) represented by the following formula (2).

[In Formula (2), R ¹¹ represents a methylene group, a sulfur atom, or an oxygen atom in which one or two hydrogen atoms may be substituted with an alkyl group having 1 to 5 carbon atoms. R ¹² and R ¹³ are the same or different and each represents a hydrogen atom or a methyl group. X ¹¹ and X ¹² are the same or different and each represents a sulfur atom or an oxygen atom. ]
[3] The curable composition for wafer level lenses according to [1] or [2], further comprising a curable compound (C) represented by the following formula (3).

[In Formula (3), Ring Z ¹ and Ring Z ² are the same or different and represent an aromatic carbocyclic ring. R ¹⁴ and R ¹⁶ are the same or different and each represents an alkylene group having 1 to 10 carbon atoms. R ¹⁵ and R ¹⁷ are the same or different and each represents a hydrogen atom or a methyl group. p1 and p2 are the same or different and represent an integer of 0 or more. ]
[4] The curable compound (A) includes at least one compound selected from the following formulas (a1) to (a10) [in formulas (a1) to (a10), m and n are as defined above]. The curable composition for wafer level lenses according to any one of [1] to [3].

[5] Curing for a wafer level lens according to any one of [2] to [4], including at least one compound selected from the following formulas (b1) to (b12) as the curable compound (B): Sex composition.

[6] The curing for a wafer level lens according to any one of [3] to [5], including at least one compound selected from the following formulas (c1) and (c2) as the curable compound (C): Sex composition.

[7] The content of the curable compound (A) is 2 to 50% by weight with respect to the total amount (100% by weight) of the curable composition, according to any one of [1] to [6]. Curable composition for wafer level lenses.
[8] The content of the curable compound (B) is 10% by weight or more with respect to the total amount (100% by weight) of the radical curable compound contained in the curable composition. The curable composition for wafer level lenses according to any one of the above.
[9] The content of the curable compound (C) is 10 to 75% by weight with respect to the total amount (100% by weight) of the radical curable compound contained in the curable composition [3] to [8]. The curable composition for wafer level lenses as described in any one of the above.
[10] Any of [3] to [9], wherein the blending ratio of the curable compound (B) and the curable compound (C) (the former / the latter (weight ratio)) is 1 / 0.2 to 1/4. The curable composition for wafer level lenses as described in any one of the above.
[11] The curable composition for wafer level lenses according to any one of [1] to [10], further comprising a trifunctional or higher functional (meth) acrylic acid ester.
[12] The curable composition for a wafer level lens according to [11], wherein the content ratio of the trifunctional or higher functional (meth) acrylic acid ester to the total amount (100% by weight) of the radical curable compound is 45% by weight or less. .
[13] The curable composition for a wafer level lens according to any one of [1] to [12], comprising a (meth) acrylic acid ester having an alicyclic ring in the molecule.
[14] The wafer level according to any one of [1] to [13], wherein a cured product obtained by heating at 150 ° C. for 30 minutes has a storage elastic modulus at 160 ° C. of 0.1 × 10 ⁹ Pa or more. A curable composition for lenses.
[15] The organic sulfur compound as a yellowing inhibitor is further contained in an amount of 0.05 to 10 parts by weight with respect to 100 parts by weight of the total amount of the radical curable compound, according to any one of [1] to [14]. Curable composition for wafer level lenses.
[16] The curable composition for wafer level lenses according to [15], wherein the organic sulfur compound is an organic sulfur compound having a boiling point of 100 ° C. or higher at normal pressure.
[17] The wafer level lens as described in any one of [1] to [16], further containing 0.05 to 5 parts by weight of a curing retarder with respect to 100 parts by weight of the total amount of the radical curable compound. Curable composition.
[18] The curable composition for wafer level lenses according to [17], wherein the curing retarder is an α-methylstyrene dimer.
[19] Further, an antioxidant as a yellowing inhibitor is contained in an amount of 0.05 to 5 parts by weight with respect to 100 parts by weight of the total amount of radical curable compounds contained in the curable composition [15] to [18]. The curable composition for wafer level lenses as described in any one of the above.
[20] The curable composition for a wafer level lens according to [19], wherein the content of the antioxidant is 0.05 to 5% by weight relative to the total amount (100% by weight) of the curable composition.
[21] Further, a radical polymerization initiator is included, and the content of the radical polymerization initiator is 0.05 to 10 parts by weight with respect to 100 parts by weight of the total amount of the radical curable compounds contained in the curable composition. The curable composition for wafer level lenses according to any one of [1] to [20].
[22] The curable composition for wafer level lenses according to any one of [1] to [21], wherein an internal transmittance at 400 nm of a cured product obtained by curing is 40% or more.
[23] The curable composition for a wafer level lens according to any one of [1] to [22], wherein a cured product obtained by curing has a refractive index (25 ° C., 589 nm) of 1.58 or more. .
[24] The curable composition for wafer level lenses according to any one of [1] to [23], wherein the Abbe number of a cured product obtained by curing is 35 or less.
[25] A method for producing a wafer level lens, comprising subjecting the curable composition for a wafer level lens according to any one of [1] to [24] to a casting molding method or an injection molding method.
[26] The method for producing a wafer level lens according to [25], wherein the casting molding method includes the following steps.
Step 1a: Step of preparing a wafer level lens molding die having one or more lens molds Step 2a: Contacting a curable composition for wafer level lenses with the wafer level lens molding step Step 3a: Wafer level The step of curing the curable composition for lenses by heating and / or light irradiation [27] The method for producing a wafer level lens according to [26], wherein the casting molding method further includes the following steps.
Step 4a: A step of annealing the cured curable composition for a wafer level lens [28] The method for producing a wafer level lens according to [26] or [27], wherein the casting molding method further includes the following steps.
Step 5a: Step of cutting the cured curable composition for a wafer level lens [29] The method for producing a wafer level lens according to [25], wherein the injection molding method includes the following steps.
Step 1b: Step of preparing a wafer level lens molding die having one or more lens molds Step 2b: Step of injecting a curable composition for wafer level lenses onto the wafer level lens molding die Step 3b: Wafer level The step of curing the curable composition for lenses by heating and / or light irradiation [30] The method for producing a wafer level lens according to [29], wherein the injection molding method further comprises the following steps.
Step 4b: Step of annealing the cured curable composition for a wafer level lens [31] A wafer level lens sheet obtained by the method for producing a wafer level lens according to [26] or [27].
[32] A wafer level lens obtained by the method for producing a wafer level lens according to any one of [25] to [30].
[33] The wafer level lens according to [32], wherein the deviation of the lens center position is ± 2 μm or less.
[34] An optical device including the wafer level lens according to [32] or [33].
[35] A laminated body of a plurality of wafer level lenses, wherein the curable composition for wafer level lenses according to any one of [1] to [24] is used as a wafer level lens constituting the laminated body. A laminated wafer level lens having at least a wafer level lens obtained by curing and molding.
[36] The laminated wafer level lens according to [35], wherein the number of wafer level lenses to be configured is 2 to 5.
[37] A method for producing a laminated wafer level lens according to [35] or [36], comprising the following steps.
Step 1c: Step of preparing a mold for molding a wafer level lens having one or more lens molds Step 2c: The wafer level lens curable composition according to any one of [1] to [24] is used as the wafer. Step of contact with level lens molding die Step 3c: Step of obtaining the wafer level lens sheet by curing the curable composition for wafer level lens by heating and / or light irradiation Step 4c: Plural including the wafer level lens sheet Step of obtaining a wafer level lens sheet laminate by laminating one wafer level lens sheet Step 5c: Step of cutting the wafer level lens sheet laminate [38] Further, the following steps are performed between Step 3c and Step 4c. A method for producing a laminated wafer level lens according to [37].
Step 6c: Step of annealing the wafer level lens sheet [39] A wafer level lens sheet laminate obtained by laminating a plurality of wafer level lens sheets including the wafer level lens sheet according to [31].
[40] An optical device on which the laminated wafer level lens according to [35] or [36] is mounted.

  Since the curable composition for a wafer level lens of the present invention has the above-described configuration, by using the curable composition, without impairing physical properties such as linear expansion coefficient and storage elastic modulus, transparency, refractive index, A cured product (wafer level lens) excellent in optical properties such as Abbe number can be obtained. Further, the curable composition for wafer level lens of the present invention is quickly relieved of internal stress caused by curing shrinkage and the like when the curable composition is heat-treated. Problems such as displacement can be suppressed, and a wafer level lens having excellent mechanical properties can be obtained efficiently.

  In this specification, the “wafer level lens” is a lens used when manufacturing a camera used for a mobile phone or the like at a wafer level, and the size thereof is, for example, about 1 to 10 mm in diameter. Preferably it is about 3-5 mm. Moreover, the thickness is about 100-1500 micrometers, for example, Preferably it is about 500-800 micrometers.

<Curable composition for wafer level lens>
The curable composition for a wafer level lens of the present invention (sometimes simply referred to as “the curable composition of the present invention”) is a compound represented by the following formula (1) (“curable compound (A)”). It is a curable composition containing as an essential component. The curable composition of the present invention may further contain components other than the curable compound (A) (for example, a curable compound (B) and a curable compound (C) described later). The curable composition of the present invention is a curable composition particularly suitable for obtaining a wafer level lens. The curable composition of the present invention includes a thermosetting composition that is cured by heating to give a cured product (resin cured product) and a photocurable composition that is cured by light irradiation to give a cured product. included.

[Curable compound (A)]
The curable compound (A) in the curable composition of the present invention is a compound represented by the above formula (1). The curable compound (A) is a radical curable compound (a curable compound having radical polymerizability) including a (meth) acryloyl group having a radical polymerizability (either one or both of an acryloyl group and a methacryloyl group).

In said formula (1), X < ¹ >, X < ² > is the same or different and shows a sulfur atom or an oxygen atom. Y ¹ and Y ² are the same or different and each represents a sulfur atom or an oxygen atom.

In the above formula (1), R ¹ represents a methylene group, a sulfur atom, or an oxygen atom in which one or two hydrogen atoms may be substituted with an alkyl group having 1 to 5 carbon atoms. As said C1-C5 alkyl group, linear or branched alkyl groups, such as a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a pentyl group, are mentioned, for example. In the case of a methylene group in which two hydrogen atoms are substituted with an alkyl group having 1 to 5 carbon atoms, the two alkyl groups having 1 to 5 carbon atoms in the methylene group may be the same. , May be different. Specific examples of the methylene group in which one or two hydrogen atoms are substituted with an alkyl group having 1 to 5 carbon atoms include a dimethylmethylene group and a methylmethylene group.

In said formula (1), R < ² >, R < ³ > is the same or different and shows an alkylene group. Examples of the alkylene group include linear or branched alkylene groups having 1 to 10 carbon atoms such as a methylene group, an ethylene group, a propylene group, a trimethylene group, a tetramethylene group, and a hexamethylene group. Among these, an alkylene group having 2 to 6 carbon atoms such as an ethylene group, a propylene group and a trimethylene group is preferable, and an alkylene group having 2 or 3 carbon atoms such as an ethylene group and a propylene group is more preferable.

In said formula (1), R < ⁴ >, R < ⁵ > is the same or different and shows a hydrogen atom or a methyl group.

In the above formula (1), m and n are the same or different and represent an integer of 0 or more. Especially, the integer of 0-4 is preferable at a point with low viscosity and excellent fluidity, More preferably, it is an integer of 1-3. However, the number (m + n) obtained by adding m and n in the formula (1) is an integer of 1 or more. That is, the curable compound (A) is a compound having at least a structural unit (oxyalkylene structure or thioalkylene structure) represented by —Y ¹ —R ² — (or —R ³ —Y ² —) in the molecule. is there.

Representative examples of the curable compound (A) include compounds represented by the following formulas (a1) to (a10). M and n in the formulas (a1) to (a10) are the same as those in the formula (1).

  As the curable compound (A), a curable composition that gives a cured product (wafer level lens) excellent in optical properties such as a low Abbe number, transparency, and a high refractive index can be obtained. Compounds represented by a1) to (a6) are preferred, more preferably compounds represented by the above formulas (a1) to (a4), and still more preferably compounds represented by the above formula (a3) or (a4). is there.

  In the curable composition of this invention, a sclerosing | hardenable compound (A) can also be used individually by 1 type, and can also be used in combination of 2 or more type.

  Although content (content ratio) of a curable compound (A) is not specifically limited, 2-50 weight% is preferable with respect to the whole quantity (total amount) (100 weight%) of a curable composition, More preferably, 3 -30% by weight, more preferably 4-20% by weight. By containing the curable compound (A) in the above proportion, transparency, refractive index, Abbe number (for example, 35 or less, preferably 30 or less), etc. without impairing physical properties such as linear expansion coefficient and storage elastic modulus. It is possible to obtain a cured product (wafer level lens) excellent in the optical characteristics. Furthermore, since the internal stress caused by curing shrinkage when heat-treating the curable composition is quickly relieved, problems such as cracks, deformation, and misalignment in the wafer level lens molding process are suppressed, and the mechanical properties are excellent. A wafer level lens can be obtained efficiently.

[Curable compound (B)]
The curable composition of the present invention may further contain a compound represented by the following formula (2) (sometimes referred to as “curable compound (B)”). The curable compound (B) is a radical curable compound containing a (meth) acryloyl group having radical polymerizability (a curable compound having radical polymerizability). When the curable composition of the present invention contains the curable compound (B), a cured product having a high storage elastic modulus, excellent shape retention in a high temperature environment, and excellent optical properties can be obtained.

In the above formula (2), R ¹¹ represents a methylene group, a sulfur atom, or an oxygen atom in which one or two hydrogen atoms may be substituted with an alkyl group having 1 to 5 carbon atoms. R ¹² and R ¹³ are the same or different and each represents a hydrogen atom or a methyl group. X ¹¹ and X ¹² are the same or different and each represents a sulfur atom or an oxygen atom.

Examples of the methylene group in which one or two hydrogen atoms in R ¹¹ may be substituted with an alkyl group having 1 to 5 carbon atoms include, for example, a methylene group (unsubstituted methylene group) and a hydrogen atom. Examples include a methylene group in which one or two are substituted with a group selected from a linear or branched alkyl group such as a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, and a pentyl group. . When two hydrogen atoms in the methylene group are substituted with the alkyl group having 1 to 5 carbon atoms, the two alkyl groups having 1 to 5 carbon atoms may be the same or different. Also good. Specific examples of the methylene group in which one or two hydrogen atoms are substituted with an alkyl group having 1 to 5 carbon atoms include a dimethylmethylene group and a methylmethylene group.

Typical examples of the curable compound (B) include compounds represented by the following formulas (b1) to (b12).

  Among the curable compounds (B), the curable composition of the present invention has a higher storage elastic modulus and excellent shape retention in a high temperature environment, and more excellent optical properties (particularly, low Abbe number and transparency). The compounds represented by the above formulas (b1) to (b6), the formula (b11), and the formula (b12) are preferable in that a cured product having a high refractive index can be formed. In particular, the compounds represented by the above formulas (b1) to (b4), the formula (b11), and the formula (b12) (most preferably, the compounds represented by the above formula (b2), the formula (b4), and the formula (b12). Compound).

  In the curable composition of this invention, a sclerosing | hardenable compound (B) can also be used individually by 1 type, and can also be used in combination of 2 or more type.

  The content (content ratio) of the curable compound (B) is the total amount (100 of radical curable compounds [curable compounds (A) to (C) and other radical curable compounds) contained in the curable composition]. 10% by weight or more, more preferably 10 to 60% by weight, further preferably 10 to 50% by weight, particularly preferably 15 to 45% by weight, and most preferably 20 to 40% by weight. is there. When content of a sclerosing | hardenable compound (B) is less than the said range, there exists a tendency for the shape retainability in the high temperature environment of the hardened | cured material obtained by hardening | curing a curable composition to fall. If the content of the curable compound (B) exceeds the above range, the stress remaining in the cured product cannot be sufficiently relaxed, and problems such as cracking, deformation, and misalignment tend to occur.

[Radical curable compound (C)]
The curable composition of the present invention may further contain a compound represented by the following formula (3) (sometimes referred to as “curable compound (C)”). The curable compound (C) is a radical curable compound containing a (meth) acryloyl group having radical polymerizability (a curable compound having radical polymerizability). When the curable composition of the present invention contains the curable compound (C), the cured product obtained by curing the curable composition has more excellent optical properties (particularly, low Abbe number and transparency). , High refractive index).

In the above formula (3), the ring Z ¹ and the ring Z ² are the same or different and represent an aromatic carbocyclic ring (aromatic hydrocarbon ring). R ¹⁴ and R ¹⁶ are the same or different and each represents an alkylene group having 1 to 10 carbon atoms. R ¹⁵ and R ¹⁷ are the same or different and each represents a hydrogen atom or a methyl group. p1 and p2 are the same or different and represent an integer of 0 or more.

Examples of the aromatic carbocycle in the ring Z ¹ and the ring Z ² include about 1 to 4 aromatic carbocycles such as a benzene ring, a naphthalene ring, and an anthracene ring. Among these, as the aromatic carbocycle, a benzene ring, a naphthalene ring and the like are preferable.

Examples of the alkylene group in R ¹⁴ and R ¹⁶ include linear or branched alkylene groups having 1 to 10 carbon atoms such as a methylene group, an ethylene group, a propylene group, a trimethylene group, a tetramethylene group, and a hexamethylene group. Is mentioned. Especially, as said alkylene group, C2-C6 alkylene groups, such as ethylene group, a propylene group, and a trimethylene group, are preferable, More preferably, it is a C2-C3 alkylene group.

  p1 and p2 are each an integer of 0 or more, preferably an integer of 0 to 4, and more preferably an integer of 1 to 4 in terms of lower viscosity and excellent fluidity.

In the formula (3), the fluorene ring, ring Z ¹ and ring Z ² may have a substituent. Examples of the substituent that the fluorene ring, ring Z ¹ , and ring Z ² may have include, for example, an alkyl group such as a methyl group, an ethyl group, a propyl group, and an isopropyl group (for example, a C _1-6 alkyl group, preferably Is a methyl group); a cycloalkyl group such as a cyclopentyl group or a cyclohexyl group (eg, a C _5-8 cycloalkyl group); an aryl group such as a phenyl group or a naphthyl group (eg, a C _6-15 aryl group); An aralkyl group such as a group (eg C _7-16 aralkyl group); an acyl group such as an acetyl group, a propionyl group or a benzoyl group (eg a C _1-10 acyl group); a methoxy group, an ethoxy group or a propyloxy group an alkoxy group such as isopropyl group (e.g., C _1-6, etc. alkoxy group); a methoxycarbonyl group, an alkoxy such as ethoxy carbonyl group Carbonyl group (e.g., C _1-4 alkoxy - carbonyl group), cyano groups, carboxyl groups, nitro groups, amino group, substituted amino group (e.g., a mono- or di-C _1-4 alkylamino group); a fluorine atom, And halogen atoms such as chlorine atom.

Specific examples of the curable compound (C) include compounds represented by the following formulas (c1) and (c2).

  In the curable composition of this invention, a curable compound (C) can also be used individually by 1 type, and can also be used in combination of 2 or more type.

  The content (content ratio) of the curable compound (C) in the curable composition of the present invention is not particularly limited, but with respect to the total amount (100% by weight) of the radical curable compound contained in the curable composition. It is preferably 10 to 75% by weight, more preferably 15 to 70% by weight, particularly preferably 20 to 65% by weight, and most preferably 25 to 60% by weight.

  When the curable composition of the present invention contains both the curable compound (B) and the curable compound (C), the mixing ratio of the curable compound (B) and the curable compound (C) (the former / the latter ( The weight ratio)) is, for example, about 1 / 0.2 to 1/4, preferably 1 / 0.3 to 1/3, and particularly preferably 1 / 0.5 to 1/2.

  By containing the curable compound (C) in the above range, the optical properties superior to the cured product [particularly, low Abbe number (for example, 35 or less, particularly 30 or less), excellent transparency, and high refractive index. When the content ratio of the curable compound (C) exceeds the above range, the fluidity of the curable composition is lowered and it becomes difficult to fill the mold, and the molding workability tends to be lowered. Moreover, there exists a tendency for the shape retainability in a high temperature environment to fall. On the other hand, when the content rate of a sclerosing | hardenable compound (C) is less than the said range, there exists a tendency for the improvement effect of an optical characteristic to become difficult to be acquired.

[Other radical curable compounds]
The curable composition of the present invention contains a radical curable compound other than the above-described curable compounds (curable compounds (A) to (C)) (sometimes referred to as “other radical curable compounds”). It may be.

  As said other radical curable compound, the well-known thru | or usual compound which has a radical curable group (radically polymerizable group) in a molecule | numerator can be used, It does not specifically limit. More specifically, for example, a curable compound having a (meth) acryloyl group or a vinyl group in the molecule can be preferably used.

  Examples of the other radical curable compounds include, for example, radical curable compounds having an aromatic ring in the molecule, and compounds other than the above-described curable compounds (curable compounds (A) to (C)) (hereinafter simply referred to as “radical curable compounds”). A radical curable compound having an alicyclic ring (aliphatic cyclic skeleton) in the molecule (hereinafter simply referred to as a “radical curable compound having an alicyclic ring”). And a radical curable compound having a chain aliphatic group in the molecule (hereinafter sometimes simply referred to as a “radical curable compound having a chain aliphatic group”).

  Examples of the aromatic ring of the radical curable compound having an aromatic ring include a benzene ring, a biphenyl ring, a naphthalene ring, a fluorene ring, an anthracene ring, a stilbene ring, a dibenzothiophene ring, and a carbazole ring. The aromatic ring may be any of an aromatic carbocyclic ring and an aromatic heterocyclic ring, but preferably contains at least an aromatic carbocyclic ring.

  Examples of the radical curable compound having an aromatic ring include a (meth) acrylic acid ester having an aromatic ring and a vinyl compound having an aromatic ring. Examples of (meth) acrylic acid ester having an aromatic ring and vinyl compound having an aromatic ring include (meth) acrylic acid ester having one (meth) acryloyloxy group in the molecule and one vinyl in the molecule. Vinyl compounds having a group, polyfunctional (meth) acrylic acid esters having two or more (meth) acryloyloxy groups in the molecule, polyfunctional vinyl compounds having two or more vinyl groups in the molecule, etc. Can be mentioned. As the (meth) acrylic acid ester having an aromatic ring, a compound in which an aromatic ring and a (meth) acryloyloxy group are directly bonded is preferable in that a high storage elastic modulus can be maintained.

  Representative examples of the (meth) acrylic acid ester having an aromatic ring include, for example, mono (meth) acrylic acid esters of bisphenols such as benzyl acrylate and bisphenol S; addition of ethylene oxide and / or propylene oxide of the bisphenols Mono (meth) acrylic acid esters of the body; (meth) acrylic acid esters in which hydrogen atoms of two hydroxyl groups of biphenol are substituted with (meth) acryloyloxy groups.

  Typical examples of the vinyl compound having an aromatic ring include divinylbenzene.

  Examples of the radical curable compound having an alicyclic ring include (meth) acrylic acid ester having an alicyclic ring in the molecule. The (meth) acrylic acid ester having an alicyclic ring in the molecule is not particularly limited as long as it is a compound having an alicyclic ring and a (meth) acryloyloxy group in the molecule. The (meth) acrylic acid ester having an alicyclic ring in the molecule preferably does not have an aromatic ring. In particular, the (meth) acrylic acid ester having an alicyclic ring in the molecule is preferably a polyfunctional (meth) acrylic acid ester having two or more (meth) acryloyloxy groups in the molecule.

Examples of the alicyclic ring of the radical curable compound having the alicyclic ring include monocyclic alicyclic rings (3 to 15 members, preferably about 5 to 6 members) such as cyclopentane ring, cyclohexane ring, cyclooctane ring and cyclododecane ring. Cycloalkane ring, etc.); decalin ring (perhydronaphthalene ring), perhydroindene ring (bicyclo [4.3.0] nonane ring), perhydroanthracene ring, perhydrofluorene ring, perhydrophenanthrene ring, perhydro Acenaphthene ring, perhydrophenalene ring, norbornane ring (bicyclo [2.2.1] heptane ring), isobornane ring, adamantane ring, bicyclo [3.3.0] octane ring, tricyclo [5.2.1. 0 ^2,6 ] decane ring, tricyclo [6.2.1.0 ^2,7 ] undecane ring, and other polycyclic (about 2 to 4 ring) alicyclic rings (bridges) Carbocyclic ring).

In the (meth) acrylic acid ester having an alicyclic ring in the molecule, the alicyclic ring and the (meth) acryloyloxy group may be directly bonded or may be bonded via a linking group. Examples of the linking group include a divalent hydrocarbon group, a carbonyl group (—CO—), an ether bond (—O—), an ester bond (—COO—), an amide bond (—CONH—), and a carbonate bond ( -OCOO-) and a group in which a plurality of these are bonded. Examples of the divalent hydrocarbon group include a linear or branched alkylene group such as a methylene group, an ethylidene group, an isopropylidene group, an ethylene group, a propylene group, a trimethylene group, and a tetramethylene group (for example, a C _1-10 alkylene group). Group, preferably C _1-6 alkylene group); 1,2-cyclopentylene group, 1,3-cyclopentylene group, cyclopentylidene group, 1,2-cyclohexylene group, 1,3-cyclohexene A divalent alicyclic hydrocarbon group (particularly a divalent cycloalkylene group) such as a xylene group, 1,4-cyclohexylene group or cyclohexylidene group; a group in which a plurality of these are bonded.

As typical examples of (meth) acrylic acid ester having an alicyclic ring in the molecule, for example, 1,4-cyclohexanediol di (meth) acrylate, 1,4-cyclohexanedimethanol di (meth) acrylate, bicyclo [2 2.1] heptane dimethanol di (meth) acrylate, 1,3-adamantanediol di (meth) acrylate, 1,3-adamantane dimethanol di (meth) acrylate, tricyclo [5.2.1.0 ^{2, 6} ] Polyfunctional (meth) acrylic acid ester such as decanedimethanol di (meth) acrylate; cyclohexyl (meth) acrylate, cyclohexane methanol (meth) acrylate, 1-adamantanol (meth) acrylate, 1-adamantane methanol (meth) ) Acrylate, isobornyl (meth) Acrylate, tricyclo [5.2.1.0 ^{2, 6]} decane methanol (meth) acrylate [= dicyclopentanyl (meth) acrylate, dicyclopentenyl oxyethyl (meth) monofunctional, such as acrylates (meth ) Acrylic acid ester.

  As the radical curable compound having a chain aliphatic group, a chain aliphatic group such as an alkyl group, an alkenyl group, an alkylene group, an alkenylene group (for example, about 1 to 20 carbon atoms, preferably And (meth) acrylic acid ester having an aliphatic group having about 1 to 12 carbon atoms.

  Representative examples of (meth) acrylic acid ester having a chain-like aliphatic group in the molecule include trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, di Polyfunctional (meth) acrylic acid esters such as pentaerythritol hexa (meth) acrylate; monofunctional (meth) acrylates such as methyl (meth) acrylate, ethyl (meth) acrylate, ethylene glycol (meth) acrylate, propylene glycol (meth) acrylate And (meth) acrylic acid alkyl ester.

  Examples of the other radical curable compounds include trifunctional or higher functional (meth) acrylic acid esters (for example, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate), A compound selected from dipentaerythritol hexa (meth) acrylate and the like) is preferable, and a tetrafunctional or higher functional (meth) acrylic acid ester is most preferable, and a hexafunctional or higher functional (meth) acrylic acid ester is particularly preferable. By using these trifunctional or higher functional (meth) acrylic acid esters alone or in combination of two or more thereof, there is a tendency that the crosslinking density is improved and the shape retention in a high temperature environment can be further improved. .

  The content ratio of the trifunctional or higher functional (meth) acrylic acid ester with respect to the total amount (100% by weight) of the radical curable compound (the total amount when containing two or more types) is not particularly limited, but is preferably 45% by weight or less. More preferably, it is 40% by weight or less, further preferably 35% by weight or less, particularly preferably 5 to 35% by weight, and most preferably 5 to 20% by weight. By adding the trifunctional or higher functional (meth) acrylic acid ester within the above range, there is a tendency that the shape retention in a high temperature environment can be further improved without deteriorating the optical properties.

  In addition, as the other radical curable compounds, monofunctional radical curable compounds (for example, (meth) acrylic acid ester having one (meth) acryloyloxy group in the molecule such as benzyl acrylate, Viscosity at 25 ° C. of about 200 mPa · s or less (particularly about 100 mPa · s or less, especially about 50 mPa · s or less) among bifunctional (meth) acrylic acid esters, such as vinyl compounds having one vinyl group) ) Can be used alone or in combination of two or more as a diluent. These include a curable compound (A) (particularly a compound represented by the formula (a3)) and a curable compound (B) (particularly a compound represented by the above formula (b1) and / or (b2)) and By mixing, the curable compound (A) and the curable compound (B) can be dissolved, the viscosity of the curable composition can be remarkably reduced, and fluidity that facilitates work can be imparted.

  The content ratio of the monofunctional radical polymerizable compound and / or the bifunctional (meth) acrylic acid ester with respect to the total amount (100% by weight) of the radical curable compound (the total amount when containing two or more types) is not particularly limited. However, it is preferably 45% by weight or less, more preferably 40% by weight or less, still more preferably 30% by weight or less, particularly preferably 5 to 30% by weight, and most preferably 5 to 20% by weight. By adding within the above range, the fluidity of the curable composition can be further improved without deteriorating the shape retention and optical characteristics in a high temperature environment.

[Yellowing inhibitor]
The curable composition of the present invention preferably contains a yellowing inhibitor. Examples of the yellowing inhibitor include organic sulfur compounds such as thiol compounds, dithiol compounds, sulfide compounds, and disulfide compounds. By mix | blending such a yellowing inhibitor, yellowing under the high temperature of the hardened | cured material obtained by hardening | curing the curable composition of this invention can be suppressed. In addition, the above-mentioned curable compound (especially curable compound (A), curable compound (B)) shall not be contained in the said organic sulfur compound.

  Generally, when a cured product of a radical curable compound having an aromatic ring is placed at a high temperature, radicals are generated in a polymer chain forming the cured product by the generated peroxide. This radical pulls out a hydrogen atom of the polymer chain to form a conjugated unsaturated bond, which may cause yellowing. When the organic sulfur compound is blended with the curable composition of the present invention, the organic sulfur compound captures peroxide generated at a high temperature, and enethiol reaction with a conjugated unsaturated bond formed in the polymer chain, Has the function of eliminating conjugated unsaturated bonds. For this reason, it is estimated that the yellowing of the hardened | cured material under high temperature can be suppressed effectively. In addition, radicals generated from organic sulfur compounds such as thiol compounds are electron-withdrawing radicals, and radical species involved in radical polymerization are also electron-withdrawing radicals. Generally, since the chain transfer ability between electron-withdrawing radicals is not high, when using an organic sulfur compound such as a thiol compound, unlike using a phenolic antioxidant as a yellowing inhibitor, It is presumed that inhibition of radical polymerization is prevented. For this reason, the curing reaction proceeds smoothly, and excellent yellowing resistance is exhibited. For example, even when exposed to a high temperature of about 260 ° C., it is possible to form a cured product that can suppress the degree of yellowing to an extremely low level. .

  The organic sulfur compound does not cause volatilization or foaming when the curable composition (a composition containing a curable compound as a monomer) is crosslinked and cured, and is contained in a cured product (resin cured product). Even when heated in a reflow process, which is a short time high-temperature heat treatment in a state as it is, it is preferable that it does not volatilize or foam, for example, a boiling point of 100 ° C. or higher (more preferably 150 ° C. or higher, further An organic sulfur compound (preferably 180 ° C. or higher) is preferable. In addition, from the viewpoint of the optical properties and the like of the cured product to be obtained, it is preferable to have a high compatibility with the curable compound and to obtain a uniform curable composition. In the present specification, the simple term “boiling point” means the boiling point at normal pressure.

  Examples of the thiol compound include 1-hexanethiol (boiling point 150 ° C.), 1-heptanethiol (boiling point 177 ° C.), 1-octanethiol (boiling point 200 ° C.), tert-octanethiol (boiling point 156 ° C.), 1- Nonanethiol, 1-decanethiol (boiling point 241 ° C), 1-undecanethiol (boiling point 104 ° C / 3mmHg), 1-dodecanethiol (boiling point 143 ° C / 16mmHg), 1-tetradecanethiol (boiling point 310 ° C), 1-hexadecane Examples thereof include linear or branched alkanethiols having about 6 to 30 carbon atoms (preferably about 6 to 20 carbon atoms) such as thiol and 1-octadecanethiol.

  Examples of the dithiol compound include 1,4-butanedithiol (boiling point 195 ° C.), 2,3-butanedithiol (boiling point 87 ° C./50 mmHg), 1,5-pentanedithiol (108 ° C./15 mmHg), 1,6 -Hexanedithiol (boiling point 237 ° C), 1,7-heptanedithiol, 1,8-octanedithiol, 1,9-nonanedithiol, 1,10-decanedithiol (boiling point 297 ° C), 1,12-dodecanedithiol, , 14-tetradecanedithiol, 1,16-hexadecanedithiol, 1,18-octadecanedithiol, etc., and a linear or branched alkanedithiol having about 4 to 30 carbon atoms (preferably about 4 to 20 carbon atoms). It is done.

  Examples of the sulfide compound include dihexyl sulfide (boiling point 260 ° C.), diheptyl sulfide (boiling point 298 ° C.), dioctyl sulfide (boiling point 309 ° C.), didecyl sulfide (boiling point 217 ° C./8 mmHg), didodecyl sulfide, ditetradecyl sulfide. , Dihexadecyl sulfide, dioctadecyl sulfide, etc., a straight or branched dialkyl sulfide (alkyl sulfide) having about 6 to 40 carbon atoms (preferably about 10 to 40 carbon atoms); diphenyl sulfide (boiling point 296 ° C.), Aromatic sulfide having about 12 to 30 carbon atoms such as phenyl-p-tolyl sulfide (boiling point 312 ° C.), 4,4-thiobisbenzenethiol (boiling point 148 ° C./12 mmHg); 3,3′-thiodipropionic acid ( Boiling point 409 ° C.), 4,4′-thiodibuta Such thiodicarboxylic acids such as acid. Of these, dialkyl sulfide is preferable.

  Examples of the disulfide compound include dipropyl disulfide (boiling point 193 ° C.), diisopropyl disulfide (boiling point 177 ° C.), dibutyl disulfide (boiling point 226 ° C.), diisobutyl disulfide (109 ° C./13 mmHg), di-tert-butyl disulfide (boiling point). 142 ° C./17 mmHg), dihexyl disulfide (boiling point 229 ° C.), diheptyl disulfide, dioctyl disulfide, didecyl disulfide (boiling point 208 ° C./2 mmHg), didodecyl disulfide, ditetradecyl disulfide, dihexadecyl disulfide, dioctadecyl disulfide, etc. And linear or branched dialkyl disulfides having about 4 to 40 carbon atoms (preferably about 6 to 40 carbon atoms).

  Among the organic sulfur compounds, thiol compounds, dithiol compounds, and disulfide compounds are preferable from the viewpoint of yellowing suppression effect, and thiol compounds and disulfide compounds are particularly preferable.

  In addition, in the curable composition of this invention, an organic sulfur compound can also be used individually by 1 type, and can also be used in combination of 2 or more type.

  The content (usage amount) of the organic sulfur compound in the curable composition of the present invention can be used within a range that does not impair the curability of the curable composition of the present invention, and depending on the type of the organic sulfur compound. Although not particularly limited, for example, 0.05 to 10 parts by weight is preferable, more preferably 0.1 to 5 parts by weight with respect to 100 parts by weight of the total amount of radical curable compounds contained in the curable composition. More preferably, it is 0.2 to 3 parts by weight. When there is too much quantity of an organic sulfur compound, sclerosis | hardenability of a curable composition may be impaired. On the other hand, when the amount of the organic sulfur compound is too small, it may be difficult to obtain the yellowing suppression effect of the cured product.

  As said yellowing inhibitor, antioxidant can also be used together with the said organic sulfur compound, for example. As the antioxidant, known or commonly used antioxidants (for example, phenolic antioxidants, hindered amine antioxidants, etc.) can be used. In addition, in the curable composition of this invention, antioxidant can also be used individually by 1 type and can also be used in combination of 2 or more type. The content (use amount) of the antioxidant is not particularly limited, but is preferably 0.05 to 5 parts by weight, more preferably 100 parts by weight of the total amount of radical curable compounds contained in the curable composition. Is 0.1 to 3 parts by weight. Alternatively, the content (use amount) of the antioxidant with respect to the total amount (100% by weight) of the curable composition is preferably 0.05 to 5% by weight, more preferably 0.1 to 3% by weight. When the usage-amount of antioxidant exceeds the said range, hardening reaction (for example, radical polymerization reaction) may be inhibited.

[Radical polymerization initiator]
The curable composition of the present invention preferably contains a radical polymerization initiator. As said radical polymerization initiator, what can raise | generate radical polymerization, such as well-known thru | or usual heat | fever radical polymerization initiator and a photo radical polymerization initiator, can be used, It does not specifically limit.

  Examples of the thermal radical polymerization initiator include organic peroxides such as hydroperoxides, dialkyl peroxides, peroxyesters, diacyl peroxides, peroxydicarbonates, peroxyketals, and ketone peroxides. An oxide etc. are mentioned. Of the thermal radical polymerization initiators, compounds that generate a gas component with the generation of radicals such as azo radical polymerization initiators are not preferable because bubbles remain in the cured product.

  Specific examples of the thermal radical polymerization initiator include, for example, t-hexyl peroxyneodecanoate [trade name “Perhexyl ND”, manufactured by NOF Corporation], t-butyl peroxyneodecanoate [product] Name “Perbutyl ND”, manufactured by NOF Corporation, t-butyl peroxyneoheptanoate [trade name “Perbutyl NHP”, manufactured by NOF Corporation], t-hexylperoxypivalate [trade name “ Perhexyl PV ", manufactured by NOF Corporation], di (3,5,5-trimethylhexanoyl) peroxide [trade name" PAROIL 355 ", manufactured by NOF Corporation], dilauroyl peroxide [trade name" Parroyl L ", manufactured by NOF Corporation, 1,1,3,3-tetramethylbutyl peroxy-2-ethylhexanoate [trade name" Perocta O ", JP Manufactured by Yushi Co., Ltd.], disuccinic acid peroxide [trade name “Perroyl SA”, manufactured by Nippon Yushi Co., Ltd.], 2,5-dimethyl-2,5-di (2-ethylhexanoylperoxy) hexane [product Name “Perhexa 250”, manufactured by NOF Corporation, t-hexylperoxy-2-ethylhexanoate [trade name “Perhexyl O”, manufactured by NOF Corporation], di (4-methylbenzoyl) par Oxide [trade name “Nyper PMB”, manufactured by Nippon Oil & Fats Co., Ltd.], t-butyl peroxy-2-ethylhexanoate [Product name “Perbutyl O”, manufactured by Nippon Oil & Fats Co., Ltd.], dibenzoyl peroxide [ Product name "Nyper BW", manufactured by NOF Corporation, 1,1-di (t-butylperoxy) -2-methylcyclohexane [trade name "Perhexa MC", manufactured by NOF Corporation 1,1-di (t-hexylperoxy) -3,3,5-trimethylcyclohexane [trade name “Perhexa TMH” manufactured by NOF Corporation], 1,1-di (t-hexylperoxy) Cyclohexane [trade name “Perhexa HC”, manufactured by NOF Corporation], 1,1-di (t-butylperoxy) cyclohexane [trade name “Perhexa C”, manufactured by NOF Corporation], 2,2- Di (4,4-di (t-butylperoxy) cyclohexyl) propane [trade name “Pertetra A”, manufactured by NOF Corporation], t-hexyl peroxyisopropyl monocarbonate [trade name “Perhexyl I”, Japan Manufactured by Yushi Co., Ltd.], t-butyl peroxylaurate [trade name “Perbutyl L”, manufactured by Nippon Yushi Co., Ltd.], t-butyl peroxyisopropyl monocarbonate [trade name “ Perbutyl I "manufactured by NOF Corporation], 2,5-dimethyl-2,5-di (benzoylperoxy) hexane [trade name" Perhexa 25Z "manufactured by NOF Corporation], t-butylperoxy Acetate [trade name “Perbutyl A”, manufactured by NOF Corporation], 2,2-di- (t-butylperoxy) butane [trade name “Perhexa 22”, manufactured by NOF Corporation], etc. .

  The photo radical polymerization initiator is a compound that initiates a radical polymerization reaction by radicals generated by decomposition by light irradiation (particularly, ultraviolet irradiation). Specific examples of the photo radical polymerization initiator include acetophenone, acetophenone benzyl ketal, anthraquinone, 1- (4-isopropylphenyl) -2-hydroxy-2-methylpropan-1-one, carbazole, xanthone, 4-chlorobenzophenone, 4,4′-diaminobenzophenone, 1,1-dimethoxydeoxybenzoin, 3,3′-dimethyl-4-methoxybenzophenone, thioxanthone compound, 2-methyl-1- [4- (methylthio) phenyl ] -2-morpholino-propan-2-one, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butan-1-one, triphenylamine, 2,4,6-trimethylbenzoyldiphenyl Phosphine oxide, bis (2,6-dimethyl) Xylbenzoyl) -2,4,4-tri-methylpentylphosphine oxide, benzyldimethyl ketal, 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, fluorenone, fluorene, Benzaldehyde, benzoin ethyl ether, benzoin propyl ether, benzophenone, Michler ketone, 3-methylacetophenone, 3,3 ′, 4,4′-tetra (t-butylperoxycarbonyl) benzophenone (BTTB), and BTTB and xanthene, thioxanthene , Coumarin, ketocoumarin and other dye sensitizer combinations. Among them, benzyldimethyl ketal, 1-hydroxycyclohexyl phenyl ketone (trade name “Irgacure 184”, manufactured by BASF), 2,4,6-trimethylbenzoyldiphenylphosphine oxide (trade name “Darocur TPO”, manufactured by BASF) 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butan-1-one and the like are particularly preferable.

  In addition, in the curable composition of this invention, a radical polymerization initiator can also be used individually by 1 type, and can also be used in combination of 2 or more type. Among these, as the radical polymerization initiator, a thermal radical polymerization initiator is preferable in that a highly accurate metal mold can be used. That is, the curable composition of the present invention is preferably a thermosetting composition that is cured by heating to give a cured product.

  The content (blending amount) of the radical polymerization initiator in the curable composition of the present invention is not particularly limited, but is 0.05 to 100 parts by weight with respect to 100 parts by weight of the total amount of radical curable compounds contained in the curable composition. 10 weight part is preferable, More preferably, it is 0.1-5 weight part, More preferably, it is 0.5-3 weight part.

[Curing retarder]
The curable composition of the present invention preferably contains a curing retardant. Examples of the curing retarder include organic compounds such as α-methylstyrene dimer, terbinolene, myrcene, limonene, α-pinene, and β-pinene. By blending such a curing retarder, the radical curing rate of the curable composition of the present invention is moderately delayed, and the curable composition at any site in the mold is cured at a substantially constant rate. It is possible to easily obtain a molded product having no ripple pattern such as “sink” or “pulse separation”.

  In general, the surface of a cured product of a radical curable composition is likely to have a ripple-like pattern called “sink” or “pulse separation”. In a radical curable system, the curable composition cures very quickly. This is thought to be due to the tendency to progress. In particular, in the case of a curable composition having a too high curing rate, the curing rate is likely to vary depending on the location in the mold, and it is considered that the above problem becomes apparent when unevenness in curing shrinkage occurs. Such a problem often occurs remarkably in casting molding using a radical curing system. When such a striped pattern is generated on the surface of an optical member such as a lens, the optical characteristics of the product cannot be exhibited uniformly, and the commercial value is significantly reduced. When a curing retarder is added to the curable composition (radical curable compound) of the present invention, the curing speed is moderately delayed, and the curing reaction proceeds uniformly at any location of the cured product, and curing is performed regardless of location. Since the functional compound is cured at a constant speed, a cured product in which generation of a wrinkle pattern such as “sink” or “pulse separation” on the surface of the molded product made of the resin cured product is suppressed can be formed.

  As the curing retarder, those which are sufficiently compatible with the curable composition and can maintain high transparency without causing haze such as cloudiness in the curable composition or the cured product are preferable. Of these, α-methylstyrene dimer is preferable.

  The content (blending amount) of the curing retarder in the curable composition of the present invention is not particularly limited, but is 0.05 to 5 with respect to 100 parts by weight of the total amount of radical curable compounds contained in the curable composition. Part by weight is preferable, more preferably 0.1 to 3 parts by weight, and still more preferably 0.5 to 2 parts by weight.

[Other ingredients]
The curable composition of the present invention may contain other components as required in addition to the above-described curable compound, yellowing inhibitor, radical polymerization initiator, and curing retardant. Examples of other components include a cationic curable compound, a cationic polymerization initiator, a curing agent, a curing accelerator, and various additives.

  Examples of the cationic curable compound include an epoxy compound having an aromatic ring, an oxetane compound, and a vinyl ether compound. Specifically, an epibis type glycidyl ether type epoxy compound, an epoxy compound having a bisarylfluorene skeleton, and the like. Is mentioned. By containing a cationic curable compound, the viscosity of a curable composition may be reduced or the curing shrinkage of a cured product may be suppressed. The content (blending amount) of the cationic curable compound in the curable composition of the present invention is not particularly limited, but is 0 to 50% by weight (for example, 5%) with respect to the total amount (100% by weight) of the curable composition. -50% by weight) is preferable, more preferably 0-30% by weight (for example, 5-30% by weight), still more preferably 0-15% by weight.

  When the curable composition of the present invention contains a cationic curable compound, the curable compound having a radical curable group and a cationic curable group in the molecule (referred to as “radical-cation curable compound”). In some cases). There exists a tendency which can improve the heat resistance of hardened | cured material by using the said cation curable compound and a radical cation curable compound together. Examples of the radical-cation curable compound include (meth) acrylic acid ester having an epoxy group in the molecule such as (meth) acrylic acid ester having an alicyclic epoxy group and (meth) acrylic acid ester having a glycidyl group. Etc.

  A cationic polymerization initiator, a curing agent, and a curing accelerator are used particularly when a cationic curable compound is blended in the curable composition of the present invention. As these cationic polymerization initiators, curing agents, and curing accelerators, known or conventional ones can be used.

  As the additive, known or commonly used additives can be used and are not particularly limited. Examples thereof include organosiloxane compounds, metal oxide particles, rubber particles, silicone-based and fluorine-based antifoaming agents, and silane cups. Examples thereof include a ring agent, a filler, a plasticizer, a leveling agent, an antistatic agent, a release agent, a flame retardant, a colorant, an antioxidant, an ultraviolet absorber, an ion adsorbent, and a pigment. The content (blending amount) of these various additives is not particularly limited, but is preferably 5% by weight or less, for example, with respect to the total amount (100% by weight) of the curable composition. Further, the curable composition of the present invention may contain a solvent, but if it is too much, bubbles may be generated in the cured product, so that it is 10% with respect to the total amount (100% by weight) of the curable composition. % Or less is preferable, and more preferably about 1% by weight or less.

  The curable composition of the present invention can be prepared by a known or conventional method, and is not particularly limited. However, a predetermined amount of the curable compound, if necessary, a yellowing inhibitor, a radical polymerization initiator, a curing delay, An agent, other components, and the like are blended, and then, for example, prepared by stirring and mixing, for example, while excluding bubbles under vacuum. Although the temperature at the time of stirring and mixing is not specifically limited, About 10-60 degreeC is preferable. For stirring and mixing, a known or conventional device such as a rotation / revolution mixer, a single or multi-screw extruder, a planetary mixer, a kneader, or a dissolver can be used.

Since the curable composition of this invention has the said structure, the hardened | cured material obtained by hardening this curable composition shows the outstanding heat resistance. Specifically, the storage elastic modulus at 160 ° C. of the cured product obtained by heating the curable composition of the present invention at 150 ° C. for 30 minutes is not particularly limited, but preferably 0.1 × 10 ⁹ Pa or more, More preferably 0.3 × 10 ⁹ to 10 × 10 ⁹ Pa, still more preferably 0.3 × 10 ^{9 to} 4.0 × 10 ⁹ Pa, and particularly preferably 0.3 × 10 ^{9 to} 2.0 × 10 ⁹ Pa. Pa.

  Moreover, since the curable composition of this invention has the said structure, the hardened | cured material obtained by hardening this curable composition is excellent in an optical characteristic. Specifically, the internal transmittance at 400 nm of the cured product obtained by curing the curable composition of the present invention is not particularly limited, but is preferably 40% or more, more preferably 50% or more, and still more preferably. 80% or more, particularly preferably 85% or more. Moreover, the refractive index (25 degreeC, 589 nm) of the said hardened | cured material is although it does not specifically limit, 1.58 or more are preferable, More preferably, it is 1.60 or more. Furthermore, although the Abbe number of the said hardened | cured material is not specifically limited, 35 or less is preferable, More preferably, it is 30 or less.

<Method for manufacturing wafer level lens>
By curing and molding the curable composition of the present invention, a wafer level lens (sometimes referred to as “wafer level lens of the present invention”) is obtained. Specifically, the wafer level lens of the present invention is obtained by a method of subjecting the curable composition of the present invention to a casting molding method or an injection molding method (sometimes referred to as “a method for producing a wafer level lens of the present invention”). can get.

  In addition, the material of the metal mold | die (wafer level lens shaping | molding die) used for shaping | molding of a wafer level lens is not specifically limited, For example, any, such as a metal, glass, a plastics, may be sufficient.

[Casting molding method]
Examples of the casting molding method include a method including the following steps 1a to 3a.
Step 1a: Step of preparing a wafer level lens molding die having one or more lens molds Step 2a: After Step 1a, contacting the curable composition of the present invention with the wafer level lens molding die Step 3a : After step 2a, the step of curing the curable composition of the present invention by heating and / or light irradiation (either heating or light irradiation or both)

  Curing of the curable composition of the present invention is performed by heat treatment and / or light irradiation (step 3a). When performing the heat treatment, the temperature can be appropriately adjusted according to the components used in the reaction, the type of catalyst, and the like, and is not particularly limited, but is preferably 100 to 200 ° C, more preferably about 120 to 160 ° C. It is. When light irradiation is performed, as the light source, for example, a mercury lamp, a xenon lamp, a carbon arc lamp, a metal halide lamp, sunlight, an electron beam source, a laser light source, or the like can be used. Moreover, after light irradiation, you may heat-process at the temperature of about 50-180 degreeC, for example, and may advance hardening reaction.

The casting molding method may further include the following step 4a after step 3a.
Step 4a: A step of annealing the cured curable composition of the present invention

  Although the said annealing process is not specifically limited, For example, it is performed by heating at the temperature of 100-200 degreeC for about 30 minutes-1 hour. The annealing process can be performed after removing the wafer level lens molding die, or can be performed without removing the mold.

  When the above casting molding method is carried out by the simultaneous molding method described later, normally, a sheet-like curing formed in a state where one or a plurality of wafer level lenses are connected by the above step 3a or step 4a. An object (wafer level lens sheet) is obtained. When the wafer level lens sheet has a plurality of wafer level lenses, these wafer level lenses may be regularly arranged (aligned) or may be randomly arranged. The wafer level lens of the present invention is obtained by cutting the wafer level lens sheet and removing the excess portion.

That is, when the casting molding method is performed by the simultaneous molding method described later, the casting molding method may further include the following step 5a after step 3a or step 4a.
Step 5a: Cutting the cured curable composition of the present invention (usually a wafer level lens sheet)

  Cutting of the cured curable composition of the present invention can be performed by known or conventional processing means.

More specifically, the casting molding method includes a simultaneous molding method including the following steps 1-1 to 1-3, an individual molding method including the following steps 2-1 and 2-2, and the like. .
(Simultaneous molding method)
Step 1-1: A step of pouring the curable composition of the present invention into a mold for molding a wafer level lens having a shape in which a plurality of lens molds are aligned in a certain direction, and curing by heating and / or light irradiation. 2: After step 1-1, the wafer level lens molding die is removed and annealed to obtain a cured product (wafer level lens sheet) having a shape in which a plurality of wafer level lenses are combined. Step 1-3: After step 1-2, the obtained cured product is cut to obtain a wafer level lens (single piece molding method)
Step 2-1: A step of pouring the curable composition of the present invention into a mold for molding a wafer level lens having one lens mold, and curing by heating and / or light irradiation Step 2-2: Step 2-1 After that, the wafer level lens forming mold is removed and an annealing process is performed to obtain a wafer level lens.

[Injection molding method]
Examples of the injection molding method include a method including the following steps 1b to 3b.
Step 1b: Step of preparing a wafer level lens molding die having one or more lens molds Step 2b: After step 1b, a step of injecting the curable composition of the present invention into the wafer level lens molding die Step 3b : The process of hardening the curable composition of this invention by heating and / or light irradiation after the process 2b.

  Curing of the curable composition of the present invention in the injection molding method is performed by heat treatment and / or light irradiation, and more specifically, can be performed in the same manner as the curing in the casting method described above.

The injection molding method may further include the following step 4b after step 3b.
Step 4b: Step of annealing the cured curable composition of the present invention

  Although the said annealing process is not specifically limited, For example, it is performed by heating at the temperature of 100-200 degreeC for about 30 minutes-1 hour. The annealing process can be performed after removing the wafer level lens molding die, or can be performed without removing the mold.

  The injection molding method may further include a step of removing burrs after the step 3b or the step 4b.

  In the simultaneous molding method in the above casting molding method, it is preferable that the curable composition of the present invention has a low viscosity and excellent fluidity from the viewpoint of excellent filling property to a wafer level lens molding die. Although it does not specifically limit as a viscosity at 25 degrees C of the curable composition of this invention used in the said simultaneous molding method, 5000 mPa * s or less is preferable, More preferably, it is 2500 mPa * s or less. By adjusting the viscosity of the curable composition of the present invention to the above range, fluidity is improved, bubbles are less likely to remain, and filling into a wafer level lens molding die is performed while suppressing an increase in injection pressure. be able to. That is, applicability and fillability can be improved, and workability can be improved over the entire molding operation of the curable composition of the present invention.

  The cured product of the curable composition of the present invention has excellent heat resistance even in a high temperature environment of about 100 to 200 ° C., and is excellent in shape retention. For this reason, even if it anneals after removing from a wafer level lens shaping type | mold, the wafer level lens which has the outstanding lens center position accuracy can be manufactured efficiently. As the lens center position accuracy, the deviation of the lens center position is preferably about ± 2 μm or less, and more preferably about ± 1 μm or less. The wafer level lens obtained by the wafer level lens manufacturing method of the present invention forms a cemented lens (laminated wafer level lens) having an extremely high number of pixels and excellent optical characteristics by laminating and bonding a plurality of wafer level lenses. be able to.

  In addition, since the cured product of the curable composition of the present invention has excellent shape retention even in a high temperature environment as described above, there is no deviation in the lens pitch even when annealing is performed, and the above simultaneous molding In step 1-3 of the method, a plurality of cured products are stacked, and the position of the cutting line is determined and cut based on the uppermost cured product, thereby separating the plurality of wafer level lenses without damaging them. The cost can be reduced and the work efficiency can be improved.

  The wafer level lens of the present invention can also be used as a component of a laminate of a plurality of wafer level lenses (sometimes referred to as a “laminated wafer level lens”). That is, the laminated wafer level lens of the present invention is a laminated wafer level lens having at least the wafer level lens of the present invention as a wafer level lens constituting the laminated wafer level lens. The wafer level lenses constituting the laminated wafer level lens of the present invention may all be the wafer level lens of the present invention, or the wafer level lens of the present invention and other wafer level lenses. The number of wafer level lenses constituting the laminated wafer level lens of the present invention is not particularly limited, but is, for example, 2 to 5 (particularly 2 to 3).

  The laminated wafer level lens of the present invention can be produced by a known or conventional method, and is not particularly limited. For example, the laminated wafer level lens is produced by laminating a plurality of wafer level lenses including the wafer level lens of the present invention. Or after obtaining a wafer level lens sheet laminate (lamination of wafer level lens sheets) by laminating a plurality of wafer level lens sheets including the wafer level lens sheet obtained by the above-mentioned simultaneous molding method. It can also be produced by cutting the wafer level lens sheet laminate. In the laminated wafer level lens of the present invention (or the wafer level lens sheet laminate), the wafer level lenses (or between the wafer level lens sheets) may be joined by a known or conventional adhesive means. And it does not need to be joined.

More specifically, the laminated wafer level lens of the present invention can be manufactured, for example, by a method including at least the following steps 1c to 5c.
Step 1c: Step of preparing a wafer level lens molding die having one or more lens molds Step 2c: After Step 1c, a step of bringing the curable composition of the present invention into contact with the wafer level lens molding die Step 3c : After step 2c, the curable composition of the present invention is cured by heating and / or light irradiation to obtain a wafer level lens sheet. Step 4c: After step 3c, a plurality of wafers including the wafer level lens sheet. Step of obtaining a wafer level lens sheet laminate by laminating level lens sheets Step 5c: Step of cutting the wafer level lens sheet laminate after step 4c

The method for manufacturing a laminated wafer level lens may further include the following steps between step 3c and step 4c.
Step 6c: Step of annealing the wafer level lens sheet

  The wafer level lens or laminated wafer level lens of the present invention has excellent heat resistance and optical characteristics, can exhibit excellent shape retention even when exposed to a high temperature environment, and has excellent optical characteristics. Can be maintained. For this reason, for example, as an imaging lens, a spectacle lens, a light beam condensing lens, a light diffusing lens, etc. for cameras (vehicle cameras, digital cameras, PC cameras, mobile phone cameras, surveillance cameras, etc.) in various optical devices It can be preferably used. The above-described optical device equipped with the wafer level lens or laminated wafer level lens of the present invention has high quality.

  Furthermore, when the wafer level lens or the laminated wafer level lens of the present invention is mounted on a circuit board, it can be soldered by reflow. For this reason, the camera module equipped with the wafer level lens or the laminated wafer level lens of the present invention is mounted on a PCB (Printed Circuit Board) substrate such as a cellular phone by the same solder reflow process as the surface mounting of other electronic components. It can be mounted directly and very efficiently, and an extremely efficient optical device can be manufactured.

  EXAMPLES Hereinafter, although an Example demonstrates this invention more concretely, this invention is not limited by these Examples.

Preparation Example 1 (Preparation of OSOM (= bis (4-methacryloyloxyphenyl) sulfide))
Triethylamine (1.3 equivalents) was added to a toluene solution obtained by diluting bis (4-hydroxyphenyl) sulfide to a concentration of 10% by weight, cooled to 0 to 5 ° C., and then methacrylic acid chloride (1.1 Equivalent) was added dropwise in the range of 0 to 5 ° C. for reaction.
After completion of the dropwise addition of methacrylic acid chloride, the mixture was further stirred for about 1 hour at room temperature, and then extracted with an aqueous hydrochloric acid solution for the purpose of removing by-produced salts. Extraction was performed using an aqueous sodium hydrogen carbonate solution for the purpose of removing raw methacrylic acid.
Thereafter, toluene was distilled off from the toluene layer under reduced pressure, and the resulting concentrated solution was subjected to column purification to obtain bis (4-methacryloyloxyphenyl) sulfide represented by the above formula (b12) (consistently). Yield: 58%).

Examples 1-6, Comparative Examples 1-3
Each component listed in Table 1 is blended according to the blending composition listed in Table 1 (numerical values are in parts by weight), and stirred and mixed at room temperature with a rotation / revolution mixer to obtain a uniform and transparent curable composition ( Radical curable composition) was obtained. The viscosity of the obtained radical curable composition was measured using a rheometer (trade name “PHYSICA UDS200”, manufactured by Paar Physica) as a viscosity at 25 ° C. and a rotation speed D = 20 / s (mPa · s). It was measured.

Abbreviations in Table 1 will be described.
[Curable compound]
B1662: Bis (4-methacryloylthiophenyl) sulfide represented by the following formula (b2), product code “B1662”, OSOM manufactured by Tokyo Chemical Industry Co., Ltd .: Bis (4-methacryloyloxyphenyl) obtained in Preparation Example 1 ) Sulfide Bis-A dimethacrylate: Bisphenol A dimethacrylate represented by the following formula (b4) EA-F5503: Compound represented by the following formula (c1) diluted with benzyl acrylate (represented by the following formula (c1) 73% by weight of the compound and 27% by weight of benzyl acrylate), trade name “Ogsol EA-F5503”, Osaka Gas Chemical Co., Ltd. EA-0200: 95% of the compound represented by the following formula (c2) %)), Trade name “Ogsol EA-0200”, Osaka Gas Chemical Co., Ltd. DPHA: Dipentaerythritol hexaacrylate represented by the formula (d1), trade name “DPHA”, manufactured by Daicel Cytec Co., Ltd. IRR-214K: tricyclo [5.2.1.0 represented by the following formula (d2) ^2,6 ] decanedimethanol diacrylate, trade name “IRR-214K”, manufactured by Daicel-Cytec, Inc. ABE-300: a compound represented by the following formula (a3) (m and n in formula (a3)) Total [m + n] is 3), trade name “ABE-300”, manufactured by Shin-Nakamura Chemical Co., Ltd. [Additives]
Dodecanethiol: yellowing inhibitor α-methylstyrene dimer: curing retarder IN1010 (IRGANOX 1010): hindered phenol antioxidant, trade name “IRGANOX 1010”, manufactured by BASF [thermal radical polymerization initiator]
Perhexa C-80: 80% by weight of 1,1-di (t-butylperoxy) cyclohexane, trade name “Perhexa C-80”, manufactured by NOF Corporation [photo radical polymerization initiator]
Irgacure 184: 1-hydroxycyclohexyl phenyl ketone, trade name “Irgacure 184”, manufactured by BASF Darocur TPO: 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide, trade name “Darocur TPO”, manufactured by BASF

Next, the curable compositions obtained in Examples and Comparative Examples were cured by the following heat treatment method or UV irradiation method to obtain a cured product. In the preparation of the lens displacement evaluation sample, a mold having seven aspherical lens shapes is used at the center of the mold, and in the other evaluation samples, a flat mold having no lens shape is used. It was.
<Heat treatment method>
Using an imprint molding machine (trade name “NANOIMPRINTER NM-0501”, manufactured by Myeongchang Kiko Co., Ltd.), with the following molding profile, cured and molded at a thickness of 0.5 mm, cooled to 80 ° C., and then released. Further, it was heated in an oven preheated to 160 ° C. for 30 minutes and annealed to obtain cured products (5 each).
Molding profile: A curable composition was applied to a mold at 25 ° C., the press shaft position was adjusted to a predetermined thickness, the mold was pressed, and the temperature was increased to 150 ° C. at 20 ° C./min. Hold at 150 ° C. for 5 minutes <UV irradiation method>
Using an imprint molding machine (trade name “NANOIMPRINTER NM-0501”, manufactured by Myeongchang Kiko Co., Ltd.), with the following molding profile, it is cured and molded at a thickness of 0.5 mm, then released, and heated to 160 ° C. in advance. The cured product was obtained by heating in an oven for 30 minutes to obtain a cured product (5 each).
Molding profile: A curable composition is applied to a mold at 25 ° C., and then the mold is pressed by adjusting the press shaft position to a predetermined thickness, and UV irradiation (irradiation intensity = 10 to 50 mW / cm, integrated irradiation) Amount = 2500-5000 mJ / cm ² )

  The following evaluation was performed about the obtained hardened | cured material.

[Lens misalignment]
The center positions of the seven lenses formed on the obtained cured product (molded product) were respectively measured with an image dimension measuring device (trade name “IM-6020”, manufactured by Keyence Corporation), and the mold The deviation of the center position of the lens from the design value was measured, and the average value was calculated.

[Glass transition temperature: Tg]
The glass transition temperature of the cured product is raised at a rate of 20 ° C./min from −50 ° C. to 250 ° C. in a nitrogen stream using a differential scanning calorimeter (trade name “Q2000”, manufactured by TA Instruments). Then, the temperature was decreased from 250 ° C. to −50 ° C. at −20 ° C./min), and then measured under a nitrogen stream at a temperature rising rate of 20 ° C./min and a measurement temperature range of −50 ° C. to 250 ° C. .

[Linear expansion coefficient]
The linear expansion coefficient of the cured product was measured using a TMA measuring device (trade name “TMA / SS100”, manufactured by SII Nanotechnology) under a nitrogen stream, at a heating rate of 5 ° C./min, and a measurement temperature range of 30 ° C. to 250 ° C. The coefficient of thermal expansion was measured at 0 ° C., and the slope of the straight line on the low temperature side was expressed as the coefficient of linear expansion. Α1 is a linear expansion coefficient (ppm / ° C.) below the glass transition temperature, and α2 is a linear expansion coefficient (ppm / ° C.) above the glass transition temperature.

[Storage modulus]
The storage elastic modulus (Pa) at 25 ° C. and 160 ° C. of the cured product was determined by a dynamic viscoelasticity measurement method (under the following measurement conditions) based on JIS K7244-7.
<Measurement conditions>
Measuring device: Solid viscoelasticity measuring device (RSA-III / TA Instruments)
Atmosphere: Nitrogen Temperature range: -30 ° C to 270 ° C
Temperature increase rate: 5 ° C / min

[Internal transmittance]
The internal transmittance of the cured product was calculated by the following formula.
Internal transmittance at 400 nm = Light transmittance at 400 nm / (1-r) ²
r = {(n−1) / (n + 1)} ²
The light transmittance at 400 nm was measured using a spectrophotometer (trade name “U-3900” manufactured by Hitachi High-Technologies Corporation). n is the refractive index at 400 nm, and the value of the refractive index at 400 nm measured by the following method was used. The internal transmittance at 450 nm was also calculated according to the above.

[Refractive index]
As the refractive index of the cured product, a refractive index of 589 nm at 25 ° C. was measured by a method based on JIS K7142 using a refractometer (trade name “Model 2010”, manufactured by Metricon).

[Abbe number]
The Abbe number of the cured product was calculated by the following formula.
Abbe number = (n _d −1) / (n _f −n _c )
In the formula, n _d represents a refractive index at 589.2 nm, n _f represents a refractive index at 486.1 nm, and n _c represents a refractive index at 656.3 nm. In addition, the value of the refractive index in each wavelength measured by the said method was used for the refractive index.

[Yellow rate]
About the hardened | cured material, after performing the heat resistance test based on the reflow temperature profile (maximum temperature: 270 degreeC) of a JEDEC specification continuously using the table | top reflow furnace made from a Shinapec company, 400 nm by the said method, and The light transmittance and refractive index at 450 nm were measured, the internal transmittance after the heat resistance test was determined, and the yellowing rate (%) was determined from the change in the internal transmittance before and after the heat resistance test by the following formula.
Yellowing rate (%) = {(Internal transmittance before heat resistance test) − (Internal transmittance after heat resistance test)} / (Internal transmittance before heat resistance test) × 100

[Phase difference]
The phase difference (nm) of the cured product is obtained by first curing the sample piece (20 mm × 20 mm × 0.5 mm) using a two-dimensional birefringence evaluation system (manufactured by Photolatice, “PA-100”). The phase difference at 25 ° C. after secondary curing (secondary curing conditions: 180 ° C., 30 minutes) is measured, and the center part of the sample piece (10 mm × 10 mm). ) Was measured by averaging the measured values at the four corners.

The evaluation results are summarized in Table 2 below.

  The wafer level lens of the present invention can be obtained by curing and molding the curable composition of the present invention. The wafer level lens of the present invention is, for example, an imaging lens, a spectacle lens, a light beam condensing lens, a light for a camera (vehicle camera, digital camera, PC camera, mobile phone camera, surveillance camera, etc.) in various optical devices. It can be preferably used as a diffusing lens.

Claims (22)

A curable composition for a wafer level lens, comprising a curable compound (A) represented by the following formula (1).

[In Formula (1), X < ¹ >, X < ² > is the same or different and shows a sulfur atom or an oxygen atom. Y ¹ and Y ² are the same or different and each represents a sulfur atom or an oxygen atom. R ¹ represents a methylene group, a sulfur atom, or an oxygen atom in which one or two hydrogen atoms may be substituted with an alkyl group having 1 to 5 carbon atoms. R ² and R ³ are the same or different and each represents an alkylene group. R ⁴ and R ⁵ are the same or different and each represents a hydrogen atom or a methyl group. m and n are the same or different and represent an integer of 0 or more. However, m + n is an integer of 1 or more. ] Furthermore, the curable composition for wafer level lenses of Claim 1 containing the sclerosing | hardenable compound (B) represented by following formula (2).

[In Formula (2), R ¹¹ represents a methylene group, a sulfur atom, or an oxygen atom in which one or two hydrogen atoms may be substituted with an alkyl group having 1 to 5 carbon atoms. R ¹² and R ¹³ are the same or different and each represents a hydrogen atom or a methyl group. X ¹¹ and X ¹² are the same or different and each represents a sulfur atom or an oxygen atom. ] Furthermore, the curable composition for wafer level lenses of Claim 1 or 2 containing the sclerosing | hardenable compound (C) represented by following formula (3).

[In Formula (3), Ring Z ¹ and Ring Z ² are the same or different and represent an aromatic carbocyclic ring. R ¹⁴ and R ¹⁶ are the same or different and each represents an alkylene group having 1 to 10 carbon atoms. R ¹⁵ and R ¹⁷ are the same or different and each represents a hydrogen atom or a methyl group. p1 and p2 are the same or different and represent an integer of 0 or more. ] The curable compound (A) includes at least one compound selected from the following formulas (a1) to (a10) [in formulas (a1) to (a10), m and n are as defined above]: 4. The curable composition for a wafer level lens according to any one of 3 above.

The curable composition for wafer level lenses according to any one of claims 2 to 4, comprising at least one compound selected from the following formulas (b1) to (b12) as the curable compound (B).

6. The curable composition for a wafer level lens according to claim 1, wherein the cured product obtained by heating at 150 ° C. for 30 minutes has a storage elastic modulus at 160 ° C. of 0.1 × 10 ⁹ Pa or more. object.   Furthermore, 0.05-10 weight part of organic sulfur compounds are contained as a yellowing inhibitor with respect to 100 weight part of whole quantity of a radical curable compound, For wafer level lenses of any one of Claims 1-6. Curable composition.   Furthermore, 0.05-5 weight part of hardening retarders are contained 0.05 to 5 weight part with respect to 100 weight part of whole quantity of a radical curable compound, The curable composition for wafer level lenses of any one of Claims 1-7.   A method for producing a wafer level lens, comprising subjecting the curable composition for a wafer level lens according to any one of claims 1 to 8 to a casting molding method or an injection molding method. The method for manufacturing a wafer level lens according to claim 9, wherein the casting molding method includes the following steps.
Step 1a: Step of preparing a wafer level lens molding die having one or more lens molds Step 2a: Contacting a curable composition for wafer level lenses with the wafer level lens molding step Step 3a: Wafer level The step of curing the curable composition for lenses by heating and / or light irradiation The method for producing a wafer level lens according to claim 10, wherein the casting molding method further includes the following steps.
Step 4a: A step of annealing the cured curable composition for a wafer level lens The method for producing a wafer level lens according to claim 10, wherein the casting molding method further includes the following steps.
Step 5a: Cutting the cured curable composition for a wafer level lens The method of manufacturing a wafer level lens according to claim 9, wherein the injection molding method includes the following steps.
Step 1b: Step of preparing a wafer level lens molding die having one or more lens molds Step 2b: Step of injecting a curable composition for wafer level lenses onto the wafer level lens molding die Step 3b: Wafer level The step of curing the curable composition for lenses by heating and / or light irradiation The method for manufacturing a wafer level lens according to claim 13, wherein the injection molding method further includes the following steps.
Step 4b: A step of annealing the cured curable composition for a wafer level lens   The wafer level lens sheet obtained by the manufacturing method of the wafer level lens of Claim 10 or 11.   The wafer level lens obtained by the manufacturing method of the wafer level lens of any one of Claims 9-14.   An optical device on which the wafer level lens according to claim 16 is mounted.   A laminate of a plurality of wafer level lenses, wherein the wafer level lens curable composition according to any one of claims 1 to 8 is cured and molded as a wafer level lens constituting the laminate. A laminated wafer level lens having at least the obtained wafer level lens. The method for producing a laminated wafer level lens according to claim 18, comprising the following steps.
Step 1c: Step of preparing a mold for molding a wafer level lens having one or more lens molds Step 2c: The wafer-level lens curable composition according to any one of claims 1 to 8 is used as the wafer-level lens. Step of contacting with mold for molding Step 3c: Step of obtaining wafer level lens sheet by curing the curable composition for wafer level lens by heating and / or light irradiation Step 4c: Plural sheets including the wafer level lens sheet Step of laminating wafer level lens sheets to obtain a wafer level lens sheet laminate Step 5c: Step of cutting the wafer level lens sheet laminate Furthermore, the manufacturing method of the lamination | stacking wafer level lens of Claim 19 including the following process between the process 3c and the process 4c.
Step 6c: A step of annealing the wafer level lens sheet   A wafer level lens sheet laminate obtained by laminating a plurality of wafer level lens sheets including the wafer level lens sheet according to claim 15.   An optical device on which the laminated wafer level lens according to claim 18 is mounted.