JP2023145995A - Manufacturing method for optical component - Google Patents

Abstract

To provide a method for manufacturing optical components that can stably obtain optical components with suppressed internal thread-like defects.SOLUTION: A method for manufacturing optical components using an injection molding apparatus, in the process of melting a resin composition containing a copolymer of ethylene or α-olefin and a cyclic olefin in a cylinder 22 of an injection unit 20, said injection unit includes a metering section 50, a compression section 60, and a supply section 70. When the cylinder setting temperature of the metering section is T1 (°C) and the cylinder setting temperatures of the supply section and the compression section are T2 (°C), the following conditions (1) to (3) are satisfied. (1) T1 is between [glass transition temperature of the resin composition (Tg)+100](°C) and [glass transition temperature of the resin composition (Tg)+180](°C), and T1 is between 180°C and 300°C. (2) T2(°C) is between [T1-25](°C) and [T1+20](°C). (3) Back pressure of injection molding equipment is 4 MPa or more and 20 MPa or less.SELECTED DRAWING: Figure 1

Description

The present invention relates to a method for manufacturing an optical member.

Cyclic olefin copolymers have excellent optical performance and are therefore used, for example, as optical members such as optical lenses.
Examples of techniques related to the method for manufacturing optical members made of cyclic olefin copolymers include those described in Patent Document 1 or 2.

Patent Document 1 discloses a method for manufacturing a cyclic olefin resin molded body using an injection molding machine equipped with a specific screw and cylinder. According to the manufacturing method, it is stated that the occurrence of black spots on the resin molded body is suppressed and the product yield during continuous operation is excellent. Note that this document does not describe cylinder temperature and back pressure.

Patent Document 2 describes an optical recording medium produced by injection molding, in which the temperature of a cyclic polyolefin thermoplastic resin and the mold temperature are set within predetermined ranges, and the shear rate and average residence time of the thermoplastic resin in a molding machine are defined. A manufacturing method is disclosed. Further, preferred injection speeds are described in Patent Document 2 (paragraph 0037, etc.). It is stated that according to the manufacturing method, the occurrence of silver streaks is suppressed and transferability is excellent. Note that this document does not describe changing the cylinder temperature setting for each position.

Japanese Patent Application Publication No. 2000-233425 Japanese Patent Application Publication No. 2001-121569

However, in the manufacturing methods described in Patent Documents 1 and 2, streak-like defects appear inside the engineering member, and a desired optical member may not be obtained.

As a result of the inventors' studies, in the process of melting the resin composition, the set temperature of the cylinder of the measuring section in the injection unit, and the set temperature of the cylinder of the supply section and compression section of the injection unit are respectively set to predetermined temperatures, At the same time, they discovered that by setting the back pressure of the injection molding device to a predetermined value during injection, it is possible to suppress the occurrence of streak-like defects inside the optical member, and that the above problems can be solved, and the present invention has been completed. Ta.
That is, the present invention can be shown below.

（上記一般式（Ｉ）において、Ｒ^３００は水素原子又は炭素原子数１～２９の直鎖状または分岐状の炭化水素基を示す。）

（上記一般式（ＩＩ）において、ｕは０または１であり、ｖは０または正の整数であり、ｗは０または１であり、Ｒ^６１～Ｒ^７８ならびにＲ^ａ１およびＲ^ｂ１は、互いに同一でも異なっていてもよく、水素原子、ハロゲン原子、炭素原子数１～２０のアルキル基、炭素原子数１～２０のハロゲン化アルキル基、炭素原子数３～１５のシクロアルキル基または炭素原子数６～２０の芳香族炭化水素基であり、Ｒ^７５～Ｒ^７８は、互いに結合して単環または多環を形成していてもよい。）

（上記一般式（ＩＩＩ）において、ｘおよびｄは０または１以上の整数であり、ｙおよびｚは０、１または２であり、Ｒ^８１～Ｒ^９９は、互いに同一でも異なっていてもよく、水素原子、ハロゲン原子、炭素原子数１～２０のアルキル基若しくは炭素原子数３～１５のシクロアルキル基である脂肪族炭化水素基、炭素原子数６～２０の芳香族炭化水素基またはアルコキシ基であり、Ｒ^８９およびＲ^９０が結合している炭素原子と、Ｒ^９３が結合している炭素原子またはＲ^９１が結合している炭素原子とは、直接あるいは炭素原子数１～３のアルキレン基を介して結合していてもよく、またｙ＝ｚ＝０のとき、Ｒ^９５とＲ^９２またはＲ^９５とＲ^９９とは互いに結合して単環または多環の芳香族環を形成していてもよい。）

（上記一般式（ＩＶ）中、ｎおよびｍはそれぞれ独立に０、１または２であり、ｑは１、２または３であり、Ｒ^１８～Ｒ^３１はそれぞれ独立に、水素原子、フッ素原子を除くハロゲン原子、またはフッ素原子を除くハロゲン原子で置換されていてもよい炭素原子数１～２０の炭化水素基であり、またｑ＝１のときＲ^２８とＲ^２９、Ｒ^２９とＲ^３０、Ｒ^３０とＲ^３１は互いに結合して単環または多環を形成していてもよく、またｑ＝２または３のときＲ^２８とＲ^２８、Ｒ^２８とＲ^２９、Ｒ^２９とＲ^３０、Ｒ^３０とＲ^３１、Ｒ^３１とＲ^３１は互いに結合して単環または多環を形成していてもよく、また上記単環または上記多環が芳香族環であってもよい。）

（上記一般式（Ｖ）において、Ｒ^１００、Ｒ^１０１は、互いに同一でも異なっていてもよく、水素原子または炭素原子数１～５の炭化水素基を示し、ｆは１≦ｆ≦１８の整数である。）

（上記一般式（ＶＩ）中、ｑは１、２または３であり、Ｒ^３２～Ｒ^３９はそれぞれ独立に、水素原子、フッ素原子を除くハロゲン原子、またはフッ素原子を除くハロゲン原子で置換されていてもよい炭素原子数１～２０の炭化水素基であり、またｑ＝１のときＲ^３６とＲ^３７、Ｒ^３７とＲ^３８、Ｒ^３８とＲ^３９は互いに結合して単環または多環を形成していてもよく、またｑ＝２または３のときＲ^３６とＲ^３６、Ｒ^３６とＲ^３７、Ｒ^３７とＲ^３８、Ｒ^３８とＲ^３９、Ｒ^３９とＲ^３９は互いに結合して単環または多環を形成していてもよく、上記単環または上記多環が二重結合を有していてもよく、また上記単環または上記多環が芳香族環であってもよい。）
［６］
上記共重合体中の前記環状オレフィン由来の繰り返し単位（ｂ）が、ビシクロ［２．２．１］－２－ヘプテン、テトラシクロ［４．４．０．１^２，５．１^７，１０］－３－ドデセンおよびベンゾノルボルナジエンからなる群から選ばれる少なくとも一種の化合物に由来する繰り返し単位を含む、上記［５］に記載の光学部材の製造方法。
［７］
上記共重合体中の前記オレフィン由来の繰り返し単位（ａ）が、エチレンに由来する繰り返し単位を含む、上記［５］または［６］に記載の光学部材の製造方法。 [1]
an injection unit consisting of a cylinder and a screw inserted into the cylinder;
a mold having a cavity for molding an optical member and a gate serving as an injection port for the resin composition from the injection unit into the cavity;
A method for manufacturing an optical member using an injection molding device, comprising:
Melting a resin composition containing a copolymer of ethylene or an α-olefin and a cyclic olefin in the cylinder;
Injecting the molten resin composition through the gate using the screw and filling the cavity,
In the step of melting the resin composition,
The injection unit includes a metering section, a compression section, and a supply section,
When the cylinder set temperature of the measuring part is T ₁ (°C), and the cylinder set temperature of the supply part and the compression part is T ₂ (°C), an optical member that satisfies the following conditions (1) to (3) is used. Production method.
(1) T ₁ is [glass transition temperature (Tg) of the resin composition + 100] (°C) or more [glass transition temperature (Tg) of the resin composition + 180] (°C) or less, and T ₁ is 180 ℃ or more and 300℃ or less (2) T ₂ (℃) is [T ₁ -25] (℃) or more and [T ₁ +20] (℃) or less (3) Back pressure of injection molding equipment is 4 MPa or more and 20 MPa or less [2]
The method for producing an optical member according to [1] above, wherein the resin composition has a glass transition temperature (Tg) of 120°C or more and 160°C or less.
[3]
The method for manufacturing an optical member according to [1] or [2] above, wherein the back pressure of the injection molding apparatus is 5 MPa or more and 20 MPa or less.
[4]
The method for producing an optical member according to any one of [1] to [3] above, wherein the T ₂ (°C) is not less than [T ₁ -20] (°C) and not more than [T ₁ +15] (°C). .
[5]
The copolymer is
At least one olefin-derived repeating unit (a) represented by the following general formula (I),
A repeating unit represented by the following general formula (II), a repeating unit represented by the following general formula (III), a repeating unit represented by the following general formula (IV), a repeating unit represented by the following general formula (V) and at least one cyclic olefin-derived repeating unit (b) selected from the group consisting of repeating units represented by the following general formula (VI);
The method for manufacturing an optical member according to any one of [1] to [4] above, comprising:

(In the above general formula (I), R ³⁰⁰ represents a hydrogen atom or a linear or branched hydrocarbon group having 1 to 29 carbon atoms.)

(In the above general formula (II), u is 0 or 1, v is 0 or a positive integer, w is 0 or 1, and R ⁶¹ to R ⁷⁸ and R ^a1 and R ^b1 are the same as each other) hydrogen atom, halogen atom, alkyl group having 1 to 20 carbon atoms, halogenated alkyl group having 1 to 20 carbon atoms, cycloalkyl group having 3 to 15 carbon atoms, or 6 carbon atoms ~20 aromatic hydrocarbon groups, and R ⁷⁵ to R ⁷⁸ may be bonded to each other to form a monocyclic or polycyclic ring.)

(In the above general formula (III), x and d are 0 or an integer of 1 or more, y and z are 0, 1 or 2, and R ⁸¹ to R ⁹⁹ may be the same or different from each other, A hydrogen atom, a halogen atom, an aliphatic hydrocarbon group which is an alkyl group having 1 to 20 carbon atoms or a cycloalkyl group having 3 to 15 carbon atoms, an aromatic hydrocarbon group having 6 to 20 carbon atoms, or an alkoxy group. The carbon atom to which R ⁸⁹ and R ⁹⁰ are bonded, the carbon atom to which R ⁹³ is bonded, or the carbon atom to which R ⁹¹ is bonded may be directly or an alkylene group having 1 to 3 carbon atoms. When y=z=0, R ⁹⁵ and R ⁹² or R ⁹⁵ and R ⁹⁹ may be bonded to each other to form a monocyclic or polycyclic aromatic ring. good.)

(In the above general formula (IV), n and m are each independently 0, 1 or 2, q is 1, 2 or 3, and R ¹⁸ to R ³¹ are each independently a hydrogen atom or a fluorine atom. A hydrocarbon group having 1 to 20 carbon atoms which may be substituted with a halogen atom excluding a fluorine atom, or a halogen atom excluding a fluorine atom, and when q=1, R ²⁸ and R ²⁹ , R ²⁹ and R ³⁰ , R ³⁰ and R ³¹ may be combined with each other to form a monocyclic or polycyclic ring, and when q=2 or 3, R ²⁸ and R ²⁸ , R ²⁸ and R ²⁹ , R ²⁹ and R ³⁰ , R ³⁰ and R ³¹ , R ³¹ and R ³¹ may be bonded to each other to form a monocyclic ring or a polycyclic ring, and the monocyclic ring or polycyclic ring may be an aromatic ring.)

(In the above general formula (V), R ¹⁰⁰ and R ¹⁰¹ may be the same or different and represent a hydrogen atom or a hydrocarbon group having 1 to 5 carbon atoms, and f is an integer of 1≦f≦18. )

(In the above general formula (VI), q is 1, 2 or 3, and R ³² to R ³⁹ are each independently substituted with a hydrogen atom, a halogen atom excluding a fluorine atom, or a halogen atom excluding a fluorine atom) When q=1, R ³⁶ and R ³⁷ , R ³⁷ and R ³⁸ , and R ³⁸ and R ³⁹ are bonded to each other to form a monocyclic or polycyclic ring. Also, when q=2 or 3, R ³⁶ and R ³⁶ , R ³⁶ and R ³⁷ , R ³⁷ and R ³⁸ , R ³⁸ and R ³⁹ , and R ³⁹ and R ³⁹ combine with each other to form a single (The monocyclic ring or the polycyclic ring may have a double bond, or the monocyclic ring or the polycyclic ring may be an aromatic ring.)
[6]
The repeating unit (b) derived from the cyclic olefin in the copolymer is bicyclo[2.2.1]-2-heptene, tetracyclo[4.4.0.1 ^2,5 . 1 ^7,10 ]-3-dodecene and benzonorbornadiene, the method for producing an optical member according to [5] above.
[7]
The method for producing an optical member according to [5] or [6] above, wherein the olefin-derived repeating unit (a) in the copolymer includes a repeating unit derived from ethylene.

According to the present invention, it is possible to stably obtain an optical member in which streak-like defects inside the optical member are suppressed.

FIG. 1 is a schematic cross-sectional view showing an example of a mold of an injection molding apparatus.

Embodiments of the present invention will be described below with reference to the drawings. Note that in all the drawings, similar components are denoted by the same reference numerals, and descriptions thereof will be omitted as appropriate. In addition, in the description of numerical ranges, the notation "a to b" means "a to b" unless otherwise specified.

The method for manufacturing an optical member according to the present embodiment includes an injection unit including a cylinder and a screw inserted into the cylinder, a cavity for molding the optical member, and a molten resin composition from the injection unit into the cavity. A method for manufacturing an optical member using an injection molding device, comprising: a mold having a gate serving as an injection port for an object, the method comprising: producing an optical member using an injection molding device; melting the resin composition, and using the screw to inject the molten resin composition through the gate and filling the cavity. In the step, the injection unit includes a metering section, a compression section, and a supply section, the cylinder set temperature of the metering section is T ₁ (° C.), and the cylinder set temperature of the supply section and the compression section is set. When is T ₂ (°C), the following conditions (1) to (3) are satisfied.
(1) T ₁ is [glass transition temperature of the resin composition +100] (°C) or more and [glass transition temperature of the resin composition +180] (°C) or less, and T ₁ is 180 °C or more and 300 °C or less ( 2) T ₂ (°C) is [T ₁ -25] (°C) or more and [T ₁ +20] (°C) or less (3) Back pressure of injection molding equipment is 4 MPa or more and 20 MPa or less

Hereinafter, the method for manufacturing the optical member of this embodiment will be described in detail.

<Injection molding equipment>
First, an injection molding apparatus used in the method for manufacturing an optical member of this embodiment will be described.

As shown in FIG. 1, the injection molding apparatus 10 of this embodiment includes an injection unit 20 and a mold 30.

The injection unit 20 includes a cylinder 22 and a screw 24 inserted into the cylinder 22, and is connected to, for example, a hopper 26 into which a resin composition is introduced. The resin composition introduced from the hopper 26 is heated and melted in the cylinder 22, and the screw 24 can transport the molten resin composition forward and inject it into the cavity 36 by a piston movement. The injection rate of the molten resin can be changed by changing the forward speed of the screw 24.

The cylinder 22 and the screw 24 inserted into the cylinder 22 include a supply section 70, a compression section 60, and a metering section 50. In the supply section 70, the resin composition that has fallen from the hopper 26 under its own weight is sent forward by the rotation of the screw 24. In the compression section 60, the resin composition sent from the supply section 70 is compressed and kneaded, and the temperature of the resin composition is increased and melted by, for example, the heat of a band heater and the frictional heat (shear heat) of rotation. The measuring section 50 is connected to, for example, the sprue 44 and injects the molten resin composition onto the sprue 44 .

Note that the preferable numerical ranges of the diameters of the cylinder 22, screw 24, nozzle, etc. are not particularly limited because they vary depending on the specifications of the injection molding apparatus and the size of the molded product.
The mold 30 includes, for example, a first mold 32 and a second mold 34, and a cavity 36 for molding an optical member having an optical surface is provided between these molds.

The cavity 36 communicates with a gate 38 that serves as an injection port for injecting molten resin from the injection unit 20 into the cavity 36 . The gate 38 communicates with, for example, a runner 40 and a sprue 44, and is configured so that the molten resin injected from the injection unit 20 can be injected and filled into the cavity 36.

The cavity 36 is an area for molding a desired optical member, and the optical member has a cross-sectional shape, for example, one-sided convex-one-sided concave, double-sided convex, double-sided concave, one-sided flat-one-sided concave, It has a one-sided flat-one-sided convex shape, one-sided flat-one-sided flat shape, etc. The optical member may have a circular shape, an elliptical shape, etc. in plan view.

The width a between the first mold 32 and the second mold 34 in the cavity 36 is, for example, 0.5 mm or more and 20 mm or less, preferably 1.5 mm or more and 15 mm or less, and more preferably 2.0 mm or more and 12 mm or less. can do.
The width of the gate 38 (the width between the first mold 32 and the second mold 34) is about 10% or more and 100% or less of the width a.

The first mold 32 has, for example, a molding surface 32a exposed in the cavity 36 for forming the optical surface of the optical member. The shape of the molding surface 32a is set according to the shape of the optical surface of the optical member, and may be a convex shape, a concave shape, or a planar shape in cross section, and may be a circular shape, an elliptical shape, etc. in a plan view. Good too. The width (or diameter in the case of a circular shape) of the molding surface 32a is indicated by b in FIG.

The area of the molding surface 32a can be, for example, 310 mm ² or more and 5030 mm ² or less, preferably 415 mm ² or more and 2850 mm ² or less, and more preferably 490 mm ² or more and 2000 mm ^{2 or} less. When the molding surface 32a is circular in plan view, the diameter b can be, for example, 20 mm or more and 80 mm or less, preferably 23 mm or more and 60 mm or less, and more preferably 25 mm or more and 50 mm or less.

The second mold 34 has, for example, a molding surface 34a exposed in the cavity 36 for forming the optical surface of the optical member. The shape of the molding surface 34a is set according to the shape of the optical surface of the optical member, and may be a convex shape, a concave shape, or a planar shape in cross section, and may be a circular shape, an elliptical shape, etc. in a plan view. Good too. The width (or diameter in the case of a circular shape) of the molding surface 34a is indicated by c in FIG.

The area of the molding surface 34a can be, for example, 310 mm ² or more and 5030 mm ² or less, preferably 415 mm ² or more and 4500 mm ² or less, and more preferably 490 mm ² or more and 4000 mm ^{2 or} less. When the molding surface 34a is circular in plan view, the diameter c can be, for example, 20 mm or more and 80 mm or less, preferably 23 mm or more and 60 mm or less, and more preferably 25 mm or more and 50 mm or less.

Note that the preferred numerical range of the widths of the runner 40, sprue 44, etc. is not particularly limited as long as the injection rate ratio b/a of the resin composition described below is ensured.

In this embodiment, a portion of the first mold 32 that constitutes the molding surface 32a is configured to be slidable, and when the portion moves toward the second mold, there is space between these molds. The injection compression molding apparatus may be configured to form the cavity by compressing the formed space.

<Method for manufacturing optical members>
The method for manufacturing an optical member according to the present embodiment uses the injection molding apparatus described above, and includes the following steps.
Step a: In the cylinder 22, a resin composition containing ethylene or a copolymer of α-olefin and cyclic olefin is melted.
Step b: Using the screw 24, the molten resin composition is injected through the gate 38 and filled into the cavity.

[Step a]
In this step, a resin composition containing ethylene or a copolymer of α-olefin and cyclic olefin is charged into the cylinder 22 via the hopper 26, and the resin composition is heated and melted within the cylinder 22. . Furthermore, by rotating the screw 24 inside the cylinder 22, it is moved to the injection nozzle.
Hereinafter, in the cylinder 22, the cylinder set temperature of the measuring section 50 of the screw will be referred to as "cylinder set temperature T ₁ of the measuring section", and the cylinder set temperature of the screw supply section 70 and compression section 60 will be referred to as "the cylinder set temperature T 1 of the screw measuring section 50". This is called the cylinder set temperature T ₂ of the compression section (excluding the temperature directly below the hopper).
Here, the "measuring part 50" is a part that quantitatively sends out the resin composition melted in the compression part 60 to a mold under a substantially constant pressure. Generally, the screw shape in the metering section 50 does not include a portion where the groove depth changes by 3% or more per L/D=1. In addition, if the boundary between the metering part 50 and the compression part 60 is difficult to distinguish, the part where the groove depth changes by 3% or more per L/D = 1 or the last part to which shear stress is applied is the exit of the compression part 60. .
The "compression section 60" is a section where the resin composition supplied from the supply section 70 is compressed, heated, and kneaded to be in a molten state and sent to the next measuring section 50. The screw shape in the compression section 60 needs to include a screw shape that applies compressive stress or shear stress to the supplied resin composition. In addition, when the boundary between the compression part 60 and the supply part 70 is difficult to distinguish, the part where the groove depth decreases by 3% or more per L/D=1 or the part where shear stress is applied is defined as the entrance of the compression part 60.
The “supply unit 70” is a unit that transports the resin composition introduced from the hopper 26 and feeds it into the compression unit 60. The shape of the screw in the supply section 70 is preferably selected such that it does not apply shear stress to the supplied resin composition.
However, if the measuring section 50, compression section 60, and supply section 70 are defined (or specified) in a commercially available injection unit, the measurement section 50, compression section 60, and supply section 70 according to this embodiment are Location shall be as defined.
Further, "the cylinder set temperature T ₁ of the measuring section" is usually the set temperature of the band heater located in the measuring section 50 of the screw, and "the cylinder set temperature T ₂ of the supply section and the compression section" is usually the set temperature of the band heater located in the measuring section 50 of the screw. This is the set temperature of the band heater located in the supply section 70 and compression section 60.
Furthermore, "excluding the area directly below the hopper" means that the set temperature of the band heater located directly below the hopper is excluded.

The lower limit of the cylinder set temperature _T1 of the measuring section in this embodiment is "glass transition temperature (Tg) + 100°C" or more, preferably "glass transition temperature (Tg) + 120°C" or more, more preferably "glass transition temperature (Tg) + 120°C" or more, (Tg)+125°C” or higher, more preferably “glass transition temperature (Tg)+130°C” or higher. When T ₁ is equal to or greater than the above lower limit, mold transferability is better, the optical member has a desired shape, and surface roughness of the optical surface can be further suppressed.
In addition, the upper limit of the cylinder set temperature _T1 of the measuring section is below the "glass transition temperature (Tg) + 180°C", preferably below the "glass transition temperature (Tg) + 160°C", more preferably below the "glass transition temperature (Tg)" ) +150°C” or lower, more preferably lower than “glass transition temperature (Tg) +140°C”. When T ₁ is below the above upper limit value, sufficient heat resistance can be obtained when the molded product is used as an optical member that requires heat resistance, such as an in-vehicle camera lens or a camera lens for a mobile device.

At the same time, the lower limit of the cylinder set temperature _T1 of the measuring section is 180°C or higher, preferably 200°C or higher, more preferably 230°C or higher, and still more preferably 250°C or higher. When T ₁ is equal to or greater than the above lower limit, mold transferability is better, the optical member has a desired shape, and surface roughness of the optical surface can be further suppressed.
Further, the upper limit of the cylinder set temperature _T1 of the measuring section is 300°C or less, preferably 290°C or less, more preferably 280°C or less. When T ₁ is below the above upper limit value, sufficient heat resistance can be obtained when the molded product is used as an optical member that requires heat resistance, such as an in-vehicle camera lens or a camera lens for a mobile device.

The lower limit of the cylinder temperature T ₂ of the supply section and the compression section in this embodiment is at least [T ₁ -25] (°C), preferably at least [T ₁ -20] (°C). When _T2 is equal to or higher than the above lower limit value, the resistance of the molten resin composition in the cylinder becomes suitable, and the additives contained in the molten resin composition can be efficiently dispersed and melted, thereby improving the resistance of the molten resin composition in the optical member. The generation of internal foreign matter can be suppressed.
Further, the upper limit of the cylinder set temperature T ₂ of the supply section and the compression section is [T ₁ +20] (°C) or less, preferably [T ₁ +15] (°C) or less, more preferably T ₁ (°C) or less, More preferably, it is [T ₁ -5] (°C) or less, even more preferably [T ₁ -10] (°C) or less, and even more preferably [T ₁ -15] (°C) or less. When T ₂ is below the above upper limit value, it is possible to suppress the occurrence of defects such as yellowing of the optical member.

In the method for manufacturing an optical member of the present embodiment, (T ₁ -T ₂ ) is preferably 30° C. or less, more preferably is 28°C or lower, more preferably 25°C or lower, even more preferably 23°C or lower.

The resin composition in this embodiment will be explained below.

(Resin composition)
The resin composition of this embodiment contains a copolymer of ethylene or an α-olefin and a cyclic olefin.

The cyclic olefin compound constituting the copolymer according to the present embodiment is not particularly limited, but examples thereof include the cyclic olefin monomers described in paragraphs 0037 to 0063 of International Publication No. 2006/118261.

The copolymer according to this embodiment has the following general formula ( A repeating unit (a) derived from at least one olefin represented by I), a repeating unit represented by the following general formula (II), a repeating unit represented by the following general formula (III), a repeating unit represented by the following general formula ( At least one cyclic olefin-derived repeating unit selected from the group consisting of a repeating unit represented by IV), a repeating unit represented by the following general formula (V), and a repeating unit represented by the following general formula (VI) (b) It is preferable to have the following.

The copolymer according to the present embodiment can further improve heat resistance and moldability while maintaining a good performance balance between transparency and refractive index of the obtained molded product, and the above-mentioned copolymer can be It is preferable that the repeating unit (a) derived from the olefin in the olefin contains a repeating unit derived from ethylene.
Moreover, the repeating unit (a) may contain two or more types, such as ethylene and propylene. The repeating unit (b) may include two or more types selected from repeating units represented by the same general formula, or may include two or more types selected from repeating units represented by different general formulas. .

In the above general formula (I), R ³⁰⁰ represents a hydrogen atom or a linear or branched hydrocarbon group having 1 to 29 carbon atoms.

In the above general formula (II), u is 0 or 1, v is 0 or a positive integer, preferably an integer of 0 to 2, more preferably 0 or 1, and w is 0 or 1, R ⁶¹ to R ⁷⁸ and R ^a1 and R ^b1 may be the same or different, and are hydrogen atoms, halogen atoms, alkyl groups having 1 to 20 carbon atoms, halogenated alkyl groups having 1 to 20 carbon atoms, It is a cycloalkyl group having 3 to 15 carbon atoms or an aromatic hydrocarbon group having 6 to 20 carbon atoms, and R ⁷⁵ to R ⁷⁸ may be bonded to each other to form a monocyclic or polycyclic ring.

In the above general formula (III), x and d are 0 or an integer of 1 or more, preferably an integer of 0 or more and 2 or less, more preferably 0 or 1, y and z are 0, 1 or 2, and R ⁸¹ to R ⁹⁹ may be the same or different from each other, and represent a hydrogen atom, a halogen atom, an aliphatic hydrocarbon group which is an alkyl group having 1 to 20 carbon atoms, or a cycloalkyl group having 3 to 15 carbon atoms; An aromatic hydrocarbon group or alkoxy group having 6 to 20 atoms, the carbon atom to which R ⁸⁹ and R ⁹⁰ are bonded, and the carbon atom to which R ⁹³ is bonded or the carbon atom to which R ⁹¹ is bonded. may be bonded directly or via an alkylene group having 1 to 3 carbon atoms, and when y=z=0, R ⁹⁵ and R ⁹² or R ⁹⁵ and R ⁹⁹ are bonded to each other. It may form a monocyclic or polycyclic aromatic ring.

In the above general formula (IV), n and m are each independently 0, 1 or 2, and q is 1, 2 or 3. m is preferably 0 or 1, more preferably 1. Preferably, n is 0 or 1, and more preferably 0. q is preferably 1 or 2, more preferably 1.

R ¹⁸ to R ³¹ are each independently a hydrogen atom, a halogen atom excluding a fluorine atom, or a hydrocarbon group having 1 to 20 carbon atoms which may be substituted with a halogen atom excluding a fluorine atom, and R ¹⁸ to Each R ³¹ is preferably independently a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms, and more preferably a hydrogen atom.

Furthermore, when q=1, R ²⁸ and R ²⁹ , R ²⁹ and R ³⁰ , and R ³⁰ and R ³¹ may be bonded to each other to form a monocyclic or polycyclic ring, and when q=2 or 3, R ²⁸ and R ²⁸ , R ²⁸ and R ²⁹ , R ²⁹ and R ³⁰ , R ³⁰ and R ³¹ , and R ³¹ and R ³¹ may be bonded to each other to form a monocyclic or polycyclic ring, and Alternatively, the polycyclic ring may be an aromatic ring.

In the above general formula (V), R ¹⁰⁰ and R ¹⁰¹ may be the same or different and represent a hydrogen atom or a hydrocarbon group having 1 to 5 carbon atoms, and f is an integer of 1≦f≦18. be.

In the general formula (VI) above, q is 1, 2 or 3, and R ³² to R ³⁹ are each independently substituted with a hydrogen atom, a halogen atom excluding a fluorine atom, or a halogen atom excluding a fluorine atom. It is a hydrocarbon group having 1 to 20 carbon atoms, and when q=1, R ³⁶ and R ³⁷ , R ³⁷ and R ³⁸ , and R ³⁸ and R ³⁹ are bonded to each other to form a monocyclic or polycyclic ring. Also, when q=2 or 3, R ³⁶ and R ³⁶ , R ³⁶ and R ³⁷ , R ³⁷ and R ³⁸ , R ³⁸ and R ^{39 , and R 39 and} R ³⁹ are bonded to each other to form a monocyclic ring. Alternatively, the monocyclic ring or the polycyclic ring may have a double bond, or the monocyclic ring or the polycyclic ring may be an aromatic ring.

Among the repeating units (b) represented by general formula (II), (III), (IV), (V) or (VI), it is preferable to have a repeating unit represented by general formula (II).
Moreover, it is preferable to include either a repeating unit represented by general formula (II) or a repeating unit represented by general formula (III), (IV), (V) or (VI).
Furthermore, it is more preferable to have repeating units represented by general formulas (II) and (VI).

The olefin monomer, which is one of the copolymerization raw materials for the copolymer according to the present embodiment, undergoes addition copolymerization to form a structural unit represented by the above general formula (I). Specifically, an olefin monomer represented by the following general formula (Ia) corresponding to the above general formula (I) is used.

In the above general formula (Ia), R ³⁰⁰ represents a hydrogen atom or a linear or branched hydrocarbon group having 1 to 29 carbon atoms. Examples of the olefin monomer represented by the above general formula (Ia) include ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 3-methyl-1-butene, 3-methyl-1-pentene, 3 -Ethyl-1-pentene, 4-methyl-1-pentene, 4-methyl-1-hexene, 4,4-dimethyl-1-hexene, 4,4-dimethyl-1-pentene, 4-ethyl-1-hexene , 3-ethyl-1-hexene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-eicosene, and the like. Among these, ethylene and propylene are preferred, and ethylene is particularly preferred, from the viewpoint of obtaining a molded product having better heat resistance, mechanical properties, and optical properties. Two or more types of olefin monomers represented by the above general formula (Ia) may be used.

When the total of the structural units constituting the copolymer according to the present embodiment is 100 mol%, the proportion of the olefin-derived repeating unit (a) is preferably 5 mol% or more and 95 mol% or less, more preferably 20 mol% or more. The content is mol% or more and 90 mol% or less, more preferably 40 mol% or more and 85 mol% or less, particularly preferably 50 mol% or more and 80 mol% or less.
Note that the proportion of repeating units (a) derived from olefin can be measured by ¹³ C-NMR.

The cyclic olefin monomer, which is one of the copolymerization raw materials of the copolymer according to the present embodiment, is subjected to addition copolymerization to form the above general formula (II), the above general formula (III), the above general formula (IV), the above general formula (V) or a repeating unit (b) derived from a cyclic olefin represented by the above general formula (VI). Specifically, the general formula (IIa) corresponding to the above general formula (II), the above general formula (III), the above general formula (IV), the above general formula (V) and the above general formula (VI), ( Cyclic olefin monomers represented by IIIa), (IVa), (Va) and (VIa) are used.

In the above general formula (IIa), u is 0 or 1, v is 0 or a positive integer, preferably an integer of 0 to 2, more preferably 0 or 1, and w is 0 or 1, R ⁶¹ to R ⁷⁸ and R ^a1 and R ^b1 may be the same or different, and are hydrogen atoms, halogen atoms, alkyl groups having 1 to 20 carbon atoms, halogenated alkyl groups having 1 to 20 carbon atoms, A cycloalkyl group having 3 to 15 carbon atoms or an aromatic hydrocarbon group having 6 to 20 carbon atoms, and R ⁷⁵ to R ⁷⁸ may be bonded to each other to form a monocyclic or polycyclic ring. .

In the above general formula (IIIa), x and d are 0 or an integer of 1 or more, preferably an integer of 0 or more and 2 or less, more preferably 0 or 1, y and z are 0, 1 or 2, and R ⁸¹ to R ⁹⁹ may be the same or different from each other, and represent a hydrogen atom, a halogen atom, an aliphatic hydrocarbon group which is an alkyl group having 1 to 20 carbon atoms, or a cycloalkyl group having 3 to 15 carbon atoms; An aromatic hydrocarbon group or alkoxy group having 6 to 20 atoms, the carbon atom to which R ⁸⁹ and R ⁹⁰ are bonded, and the carbon atom to which R ⁹³ is bonded or the carbon atom to which R ⁹¹ is bonded. may be bonded directly or via an alkylene group having 1 to 3 carbon atoms, and when y=z=0, R ⁹⁵ and R ⁹² or R ⁹⁵ and R ⁹⁹ are bonded to each other. It may form a monocyclic or polycyclic aromatic ring.

In the general formula (IVa), n and m are each independently 0, 1 or 2, and q is 1, 2 or 3. m is preferably 0 or 1, more preferably 1. Preferably, n is 0 or 1, and more preferably 0. q is preferably 1 or 2, more preferably 1.

R ¹⁸ to R ³¹ are each independently a hydrogen atom, a halogen atom excluding a fluorine atom, or a hydrocarbon group having 1 to 20 carbon atoms which may be substituted with a halogen atom excluding a fluorine atom, and R ¹⁸ to Each R ³¹ is preferably independently a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms, and more preferably a hydrogen atom.

Furthermore, when q=1, R ²⁸ and R ²⁹ , R ²⁹ and R ³⁰ , and R ³⁰ and R ³¹ may be bonded to each other to form a monocyclic or polycyclic ring, and when q=2 or 3, R ²⁸ and R ²⁸ , R ²⁸ and R ²⁹ , R ²⁹ and R ³⁰ , R ³⁰ and R ³¹ , and R ³¹ and R ³¹ may be bonded to each other to form a monocyclic or polycyclic ring, and Alternatively, the polycyclic ring may be an aromatic ring.

In the above general formula (Va), R ¹⁰⁰ and R ¹⁰¹ may be the same or different and represent a hydrogen atom or a hydrocarbon group having 1 to 5 carbon atoms, and f is an integer of 1≦f≦18. be.

In the above general formula (VIa), q is 1, 2 or 3, preferably 1 or 2, and more preferably 1.

R ³² to R ³⁹ are each independently a hydrogen atom, a halogen atom excluding a fluorine atom, or a hydrocarbon group having 1 to 20 carbon atoms which may be substituted with a halogen atom excluding a fluorine atom.
R ³² to R ³⁹ are each preferably independently a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms, and more preferably a hydrogen atom.

Furthermore, when q=1, R ³⁶ and R ³⁷ , R ³⁷ and R ³⁸ , and R ³⁸ and R ³⁹ may be bonded to each other to form a monocyclic or polycyclic ring, and when q=2 or 3, R ³⁶ and R ³⁶ , R ³⁶ and R ³⁷ , R ³⁷ and R ³⁸ , R ³⁸ and R ³⁹ , R ³⁹ and R ³⁹ may be bonded to each other to form a monocyclic or polycyclic ring, and the above monocyclic or The polycyclic ring may have a double bond, and the monocyclic ring or polycyclic ring may be an aromatic ring.

Examples of the hydrocarbon group having 1 to 20 carbon atoms include, for example, an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 15 carbon atoms, and an aromatic hydrocarbon group. It will be done. More specifically, examples of the alkyl group include methyl group, ethyl group, propyl group, isopropyl group, amyl group, hexyl group, octyl group, decyl group, dodecyl group, and octadecyl group, and examples of the cycloalkyl group include cyclohexyl group. Examples of the aromatic hydrocarbon group include aryl or aralkyl groups such as phenyl, tolyl, naphthyl, benzyl, and phenylethyl groups. These hydrocarbon groups may be substituted with halogen atoms other than fluorine atoms.

As a copolymerization component, an olefin monomer represented by the above-mentioned general formula (Ia), a cyclic olefin monomer represented by the general formula (IIa), (IIIa), (IVa), (Va) or (VIa) may be used. This further improves the solubility of the copolymer in a solvent, resulting in better moldability and improved product yield.

As specific examples of the cyclic olefin monomer represented by the general formula (IIa), (IIIa) or (Va), the compounds described in paragraphs 0037 to 0063 of International Publication No. 2006/118261 can be used.

Specifically, bicyclo-2-heptene derivatives (bicyclohept-2-ene derivatives), tricyclo-3-decene derivatives, tricyclo-3-undecene derivatives, tetracyclo-3-dodecene derivatives, pentacyclo-4-pentadecene derivatives, pentacyclo Pentadecadiene derivative, pentacyclo-3-pentadecene derivative, pentacyclo-4-hexadecene derivative, pentacyclo-3-hexadecene derivative, hexacyclo-4-heptadecene derivative, heptacyclo-5-eicosene derivative, heptacyclo-4-eicosene derivative, heptacyclo-5 -heneicosene derivative, octacyclo-5-docosene derivative, nonacyclo-5-pentacosene derivative, nonacyclo-6-hexacosene derivative, cyclopentadiene-acenaphthylene adduct, 1,4-methanol-1,4,4a,9a-tetrahydrofluorene derivative, Examples include 1,4-methano-1,4,4a,5,10,10a-hexahydroanthracene derivatives and cycloalkylene derivatives having 3 to 20 carbon atoms.

Among the cyclic olefin monomers represented by the general formula (IIa), (IIIa), (IVa), (Va) or (VIa), the cyclic olefin represented by the general formula (IIa) is preferred.

Further, it is preferable to use either a cyclic olefin represented by the general formula (IIa) or a cyclic olefin represented by the general formula (IIIa), (IVa), (Va) or (VIa).

Examples of the cyclic olefin monomer represented by the general formula (IIa) include bicyclo[2.2.1]-2-heptene (also called norbornene), tetracyclo[4.4.0.1 ^2,5 . 1 ^7,10 ]-3-dodecene (also called tetracyclododecene) is preferably used, and tetracyclo[4.4.0.1 ^2,5 . 1 ^7,10 ]-3-dodecene is more preferably used. Since these cyclic olefins have a rigid ring structure, there is an advantage that the elastic modulus of the copolymer and the molded article is easily maintained.

As the cyclic olefin monomer represented by the above general formula (VIa), it is preferable to use a monomer in which q=1 in the formula (VIa). Since these cyclic olefins have one benzene ring, they have the advantage that a resin composition that is less likely to be colored can be easily obtained compared to a case where the cyclic olefins have two or more benzene rings. In particular, it is preferable to use benzonorbornadiene. The advantage of using benzonorbornadiene is that it has an aromatic ring, so the refractive index of the resin composition can be increased.
Examples of the cyclic olefin monomer include bicyclo[2.2.1]-2-heptene, tetracyclo[4.4.0.1 ^2,5 . At least one compound selected from the group consisting of 1 ^7,10 ]-3-dodecene and benzonorbornadiene is preferred, including bicyclo[2.2.1]-2-heptene and tetracyclo[4.4.0.1 ^2,5 ．． 1 ^7,10 ]-3-dodecene is more preferred, and at least one compound selected from the group consisting of tetracyclo[4.4.0.1 ^2,5 . 1 ^7,10 ]-3-dodecene is more preferred.

When the total of the structural units constituting the copolymer according to this embodiment is 100 mol%, the proportion of the repeating unit (b) derived from the cyclic olefin monomer is preferably 5 mol% or more and 95 mol% or less, more preferably is 10 mol% or more and 80 mol% or less, more preferably 15 mol% or more and 60 mol% or less, particularly preferably 20 mol% or more and 50 mol% or less.

The copolymer type of the copolymer according to the present embodiment is not particularly limited, and examples thereof include a random copolymer, a block copolymer, and the like. In this embodiment, a random copolymer is used as the copolymer according to this embodiment from the viewpoint of being able to obtain a highly accurate optical member with excellent optical properties such as transparency, refractive index, and birefringence. It is preferable to use
The copolymer according to this embodiment can contain one or more of the above-mentioned copolymers.

The copolymer according to this embodiment includes ethylene and tetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ]-3-dodecene, random copolymers of ethylene and bicyclo[2.2.1]-2-heptene, and ethylene and tetracyclo[4.4.0.1 ^{2, 5} . 1 ^7,10 ]-3-dodecene and benzonorbornadiene, preferably a random copolymer of ethylene and tetracyclo[4.4.0.1 ^2,5 . Random copolymers with 1 ^7,10 ]-3-dodecene and ethylene with tetracyclo[4.4.0.1 ^2,5 . A random copolymer of ethylene and ^tetracyclo [4.4.0.1 ^2,5 . A random copolymer with 1 ^7,10 ]-3-dodecene is more preferred.

(Other ingredients)
In addition to the cyclic olefin copolymer, the resin composition in this embodiment can contain known additives as optional components within a range that does not impair the good physical properties of the optical member in this embodiment.

Examples of additives include hydrophilic stabilizers, hydrophilic agents, antioxidants, secondary antioxidants, lubricants, mold release agents, antifogging agents, weathering stabilizers, light stabilizers, ultraviolet absorbers, and antistatic agents. , metal deactivators, and the like.
Among the above, it is preferable that the resin in this embodiment contains a hydrophilic stabilizer. It is more preferable to include a hydrophilic stabilizer because deterioration of optical performance under high temperature and high humidity conditions can be suppressed.

The hydrophilic stabilizer is preferably a fatty acid ester of a fatty acid and a polyhydric alcohol. More preferred are fatty acid esters of fatty acids and polyhydric alcohols having one or more ether groups.

In this embodiment, the lower limit of the content of the cyclic olefin copolymer in the resin composition is preferably 70% by mass or more, more preferably 80% by mass or more when the entire resin composition is 100% by mass. , more preferably 90% by mass or more, particularly preferably 95% by mass or more. When the content of the copolymer in the resin composition is at least the above lower limit, optical performance can be further improved.
The upper limit of the content of the cyclic olefin copolymer in the resin composition is not particularly limited, but is, for example, 100% by mass or less.

The upper limit of the glass transition temperature (Tg) of the resin composition of the present embodiment is preferably 160°C or lower, more preferably 155°C or lower, even more preferably 150°C or lower, and still more preferably 145°C or lower. . If the glass transition temperature (Tg) of the resin composition is below the upper limit above, the molded product will have sufficient heat resistance when used as an optical member that requires heat resistance, such as an in-vehicle camera lens or a camera lens for a mobile device. can be obtained.
Further, the lower limit of the glass transition temperature (Tg) of the resin composition of the present embodiment is preferably 120°C or higher, more preferably 125°C or higher, and still more preferably 130°C or higher. When the glass transition temperature (Tg) of the resin composition is equal to or higher than the above lower limit, mold transferability is better, a desired shape can be obtained, and surface roughness of the optical surface can be further suppressed.

In addition, in this embodiment, when there are multiple glass transition temperatures, such as when the resin composition contains two or more types of the above-mentioned copolymers or when it contains other components having glass transition temperatures, The higher glass transition temperature is used.

The glass transition temperature (Tg) of the resin composition of the present embodiment can be determined by heating the resin composition from room temperature to 200°C at a heating rate of 10°C/min in a nitrogen atmosphere using, for example, DSC-6220 manufactured by Shimadzu Science Co., Ltd. After that, the temperature was held for 5 minutes, then the temperature was lowered to -20°C at a cooling rate of 10°C/min, held for 5 minutes, and then the glass transition temperature was measured when the temperature was raised to 200°C at a heating rate of 10°C/min. can do.

[Step b]
In this step, the melted resin composition obtained in step a is injected through the gate 38 using the screw 24 to fill the cavity 36 .

Specifically, as the nozzle at the tip of the cylinder 22 opens and the screw 24 moves forward, the molten resin composition passes through the sprue 44 and the runner 40 and is injected through the gate 38.

The lower limit of the back pressure of the injection molding apparatus in this embodiment is 4 MPa or more, preferably 5 MPa or more, more preferably 7 MPa or more, and even more preferably 10 MPa or more. By setting the back pressure to the above lower limit value or more, the resistance of the molten resin composition in the cylinder becomes suitable, and the additives contained in the molten resin composition can be efficiently dispersed and melted. The generation of internal foreign matter inside can be suppressed.
Further, the upper limit of the back pressure is 20 MPa or less, preferably 17 MPa or less, more preferably 15 MPa or less, still more preferably 13 MPa or less. By setting the back pressure to the above upper limit value or less, mold transferability is improved, the optical member has a desired shape, and surface roughness of the optical surface can be further suppressed.

From the viewpoint of the effects of this embodiment, the injection rate b (cm ^{3 /sec) of the molten resin composition inside the cavity 36 is compared to the injection rate a (cm 3 /} sec) of the molten resin composition when passing through the gate 38. ) can be set to, for example, 1.5 to 6.5, preferably 2.0 to 6.0, and more preferably 2.5 to 5.5.

By satisfying the injection rate ratio b/a, mold transferability is excellent, and optical members such as optical lenses that have a desired shape and have excellent surface smoothness with suppressed surface roughness of the optical surface can be provided. can do.

Note that the injection rate of the sprue 44 and the runner 40 is not particularly limited, but from the viewpoint of productivity, it is preferably the same as or higher than the injection rate of the molten resin composition when passing through the gate 38.

Note that the injection rate and filling speed of the molten resin can be changed by the forward speed of the screw 24, and the injection rate and filling speed of the molten resin can be determined by the forward speed.

Note that step b can also be performed using an injection compression molding device.
That is, in FIG. 1, the cavity 36 is formed by compressing the space formed between these molds by moving the first mold 32 in the direction of the second mold 34. A conventional injection compression molding apparatus can be used. Specifically, the part that constitutes the molding surface 32a of the first mold 32 is configured to be slidable, and when this part moves in the direction of the second mold 34, there is a space between these molds. The cavity 36 is formed by compressing the formed space.

In step b, when using an injection compression molding device, the screw 24 is used to inject the molten resin composition into the space through the gate 38, and the portion constituting the molding surface 32a of the first mold 32 is By moving in the direction of the second mold 34 and compressing the space into the shape of the cavity 36, the molten resin composition can be pressed and the cavity 36 can be filled with the molten resin composition.

The length compressed from the space into the cavity 36 (compression distance) varies depending on the size of the cavity 36, but can be set to, for example, 500 to 5000 μm, preferably 1000 to 4000 μm, and more preferably 1500 to 3000 μm. .
In addition to adjusting the injection rate, by applying stress to the molten resin composition through compression molding, it is possible to improve the transferability of the mold, which allows the mold to have the desired shape and further suppress the surface roughness of the optical surface. An optical member with a smooth surface can be obtained, and an optical member with smaller birefringence can also be obtained.

After step b, the resin in the mold is cooled and solidified according to a conventional method, and then the mold is opened and the resin molded product (optical member) is taken out. The cooling time is not particularly limited, but is usually 1 to 500 seconds.

[Optical member]
The resin molded body (optical member) obtained by the manufacturing method of this embodiment has, for example, a circular effective optical surface (diameter b) and a circular effective optical surface (diameter c) on the back surface thereof.
In the optical member obtained by the manufacturing method of this embodiment, streak-like defects inside the optical member are suppressed.

Since the optical member according to this embodiment contains a cyclic olefin copolymer, it has excellent optical performance. Therefore, it can be suitably used as an optical member in an optical system that needs to identify images with high precision. Optical members are parts used in optical equipment, etc., and specifically include sensor lenses, pickup lenses, projector lenses, prisms, fθ lenses, imaging lenses, light guide plates, etc. From the viewpoint of effectiveness, it can be suitably used for fθ lenses, imaging lenses, sensor lenses, prisms, or light guide plates.

Examples of lens shapes include convex lenses with spherical surfaces on both sides, concave lenses with spherical surfaces on both sides, lenses with spherical and convex surfaces on one side and aspherical surfaces on the other, and lenses with spherical and concave surfaces on one side and aspherical surfaces on the other. Examples include spherical lenses, diffractive lenses, Fresnel lenses, wafer lenses, and wafer lens arrays.

In particular, since the optical member according to this embodiment has a desired shape and has suppressed surface roughness on the optical surface, it can be used not only for the above-mentioned conventional optical member but also for automotive camera lenses. It can also be used for optical members such as camera lenses for mobile devices (mobile phones, smartphones, tablets, etc.). In-vehicle camera lenses and camera lenses for mobile devices include, for example, view camera lenses, sensing camera lenses, light convergence lenses for head-up displays, light diffusion lenses for head-up displays, personal computer cameras, and mobile phone cameras. , lenses for various optical devices such as cameras for smartphones, cameras for tablet terminals, cameras for mobile devices, digital cameras, and cameras for medical equipment. In addition, the in-vehicle camera may take visible images, infrared images, or both, and in the case of visible images, it may take black and white images. It may be a color image. Applications other than those mentioned above include automobile interior panels, automobile lamp lenses, automobile inner lenses, automobile lens protective covers, automobile light guides, and the like. The optical member according to this embodiment can be particularly suitably used for vehicle mounting.

Although the embodiments of the present invention have been described above, these are merely examples of the present invention, and various configurations other than those described above can be adopted within a range that does not impair the effects of the present invention.

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

<Manufacturing example>
<Preparation of resin composition A>
(Preparation of catalyst)
A vanadium catalyst having a vanadium concentration of 6.7 mmol/L-cyclohexane was prepared by diluting VO(OC ₂ H ₅ )Cl ₂ with cyclohexane. Ethylaluminum sesquichloride (Al(C ₂ H ₅ ) _1.5 Cl _1.5 ) was diluted with cyclohexane to prepare an organoaluminum compound catalyst having an aluminum concentration of 107 mmol/L-hexane.

(polymerization)
Ethylene and tetracyclo[4.4.0.1 ^2,5 . A copolymerization reaction with 1 ^7,10 ]-3-dodecene was carried out. Here, ethylene was supplied into the polymerization vessel together with hydrogen gas. When carrying out this copolymerization reaction, the vanadium catalyst prepared by the above method is added to the polymerization vessel in an amount such that the concentration of vanadium catalyst to cyclohexane in the polymerization vessel used as a polymerization solvent is 0.6 mmol/L. supplied within. Further, ethylaluminum sesquichloride, which is an organoaluminum compound, was supplied into the polymerization vessel in an amount such that Al/V=18.0. The copolymerization reaction was carried out continuously at a polymerization temperature of 8° C. and a polymerization pressure of 1.8 kg/cm ² G.

(Demineralization)
Ethylene and tetracyclo[4.4.0.1 ^2,5 . To the copolymer solution with 1 ^7,10 ]-3-dodecene, water and an aqueous sodium hydroxide solution having a concentration of 25% by mass as a pH adjuster were added to stop the polymerization reaction. Further, catalyst residue present in the copolymer was removed (deashed) from the copolymer solution. Ethylene and tetracyclo[4.4.0.1 ^2,5 . Pentaerythrityl- ^tetrakis [3-(3,5-di-t-butyl-4 -hydroxyphenyl)propionate] was added in an amount of 0.4 parts by mass based on 100 parts by mass of the copolymer. Next, before entering the flash drying process, the mixture was mixed for 1 hour using a stirring tank with an effective volume of 1.0 m ³ .

(Desolvation)
A copolymer concentration of 5% by mass in a cyclohexane solution was placed in a double tube heater (outer tube diameter 2B, inner tube diameter 3/4B, length 21 m) using 20 kg/cm ² G steam as a heat source. A solution of the above copolymer in cyclohexane was supplied at a rate of 150 kg/h and heated to 180°C.
The above heating was carried out using a double tube flash dryer (outer tube diameter 2B, inner tube diameter 3/4B, length 27 m) using 25 kg/cm ² G steam as a heat source and a flash hopper (volume 200 L). Most of the unreacted monomers are removed from the cyclohexane solution of the copolymer that has gone through the process, along with cyclohexane, which is the polymerization solvent, and flash-dried molten ethylene and tetracyclo[4.4.0.1 ^2,5 . A random copolymer (cyclic olefin copolymer (A-1)) with 1 ^7,10 ]-3-dodecene was obtained.The glass transition temperature Tg (°C) of the cyclic olefin copolymer was determined by the method described below. When evaluated, it was 155°C.

(extrusion)
As a fatty acid ester, EXEPAL PE-MS (manufactured by Kao Corporation) was heated at 100°C for 4 hours in a molten state, and in an amount of 2.1 parts by mass per 100 parts by mass of the cyclic olefin copolymer (A-1). The cyclic olefin copolymer (A-1) is directly charged into a vented twin-screw kneading extruder and kneaded with the cyclic olefin copolymer (A-1) charged from the resin charging section of the extruder, and an underwater pelletizer attached to the extruder outlet is used. The resulting pellets were dried with hot air at a temperature of 100° C. for 4 hours to obtain a resin composition A.

[Glass transition temperature Tg (°C)]
The glass transition temperature Tg of the resin composition was measured in an N ₂ (nitrogen) atmosphere using DSC-6220 manufactured by Shimadzu Science. The resin composition was heated from room temperature to 200°C at a temperature increase rate of 10°C/min and held for 5 minutes, and then cooled to -20°C at a cooling rate of 10°C/min and held for 5 minutes. Then, the glass transition temperature (Tg) of the resin composition was determined from the endothermic curve when the temperature was raised to 200°C at a heating rate of 10°C/min. The glass transition temperature (Tg) of resin composition A was 140°C.

<Preparation of resin composition B>
Resin composition A was prepared in the same manner as resin composition A except that cyclic olefin copolymer (B-1) (glass transition temperature (Tg): 145°C) was used instead of cyclic olefin copolymer (A-1). Resin composition B was synthesized. The glass transition temperature (Tg) of resin composition B was 130°C.

(Production of optical member)
<Example 1>
An optical member was manufactured using an injection molding device equipped with a mold having the following size.
The screw rotation speed was 30 rpm, T ₁ (set temperature of the band heater located in the measuring section 50 of the screw) was 265° C., and T ₂ (set temperature of the band heater located in the supply section 70 and compression section 60 of the screw) was 240. ℃ and a back pressure of 5 MPa, the resin composition A was melted and injected into the cavity from the injection unit through the gate. At this time, the mold temperature was 130° C., the pressure was kept at 90 MPa, the resin in the mold was cooled and solidified, and then the mold was opened to obtain a resin molded product (optical member). Further, the same operation was repeated to obtain a total of 50 optical members.
(Mold size)
- Diameter (width) b of molding surface 32a of first mold 32: φ46 mm
・Area of molding surface 32a: 1661 mm ²
- Diameter (width) c of molding surface 34a (plane) of second mold 34: φ46 mm
・Area of molding surface 34a: 3524mm ²
・Thickness a of molding area (optically effective part): 10 mm
・Width of gate 38: 2mm
- Lens shape: plano-convex lens Here, in the injection molding apparatus used in the example, the "measuring part 50" refers to a part located at the tip of the screw 24 and having a length of 15% of the total length. The "compression part 60" refers to a part of the screw 24 that exists after the metering part 50 when viewed from the tip and has a length of 25% of the total length. The "supply section 70" refers to a portion of the screw 24 that exists after the compression section 60 when viewed from the tip and has a length of 40% of the total length. "Directly below the hopper" refers to a portion of the screw 24 that exists after the supply section 70 when viewed from the tip, is located at the rearmost end of the screw 24, and has a length of 20% of the total length.

<Examples 2 to 4, Comparative Examples 1 to 3>
Fifty resin molded products (optical members) were produced in the same manner as in Example 1 except that the conditions listed in Table 1 were used.

[Evaluation method of optical members]
The obtained optical member was evaluated by the following method.

[Defect rate]
For 50 optical members of each Example and each Comparative Example, the optical members were illuminated from the side of the molded product in a dark room using a flexible light whose light source was a halogen lamp, and streak-like internal foreign substances were observed with the naked eye. Lenses in which even one streak-like internal foreign substance was observed were considered to be defective, and 50 lenses were observed for each lens to determine the defective rate. The defective rate was classified according to the following criteria.
(Judgment criteria)
◎ Defective rate: 30% or less 〇 Defective rate: 31% or more and 50% or less × Defective rate: 51% or more

In Table 1, each example in which the cylinder set temperature of the measuring section, the cylinder set temperature of the supply section and the compression section were set to a predetermined temperature, and at the same time the pressure at the time of injection was set to a predetermined value, the line-shaped inside of the optical member We were able to suppress the occurrence of defects.

10 Injection molding device 20 Injection unit 22 Cylinder 24 Screw 26 Hopper 30 Mold 32 First mold 32a Molding surface 34 Second mold 34a Molding surface 36 Cavity 38 Gate 40 Runner 44 Sprue 50 Measuring section 60 Compression section 70 Supply section

Claims (7)

an injection unit consisting of a cylinder and a screw inserted into the cylinder;
a mold having a cavity for molding an optical member and a gate serving as an injection port for the resin composition from the injection unit into the cavity;
A method for manufacturing an optical member using an injection molding device, comprising:
Melting a resin composition containing a copolymer of ethylene or an α-olefin and a cyclic olefin in the cylinder;
Injecting the molten resin composition through the gate using the screw and filling the cavity,
In the step of melting the resin composition,
The injection unit includes a metering section, a compression section, and a supply section,
When the cylinder set temperature of the measuring part is T ₁ (°C), and the cylinder set temperature of the supply part and the compression part is T ₂ (°C), an optical member that satisfies the following conditions (1) to (3) is used. Production method.
(1) T ₁ is [glass transition temperature (Tg) of the resin composition + 100] (°C) or more [glass transition temperature (Tg) of the resin composition + 180] (°C) or less, and T ₁ is 180 ℃ or more and 300℃ or less (2) T ₂ (℃) is [T ₁ -25] (℃) or more and [T ₁ +20] (℃) or less (3) The back pressure of the injection molding equipment is 4 MPa or more and 20 MPa or less The method for manufacturing an optical member according to claim 1, wherein the resin composition has a glass transition temperature (Tg) of 120°C or more and 160°C or less. The method for manufacturing an optical member according to claim 1 or 2, wherein the back pressure of the injection molding device is 5 MPa or more and 20 MPa or less. The method for manufacturing an optical member according to any one of claims 1 to 3, wherein the T ₂ (°C) is not less than [T ₁ -20] (°C) and not more than [T ₁ +15] (°C). The copolymer is
At least one olefin-derived repeating unit (a) represented by the following general formula (I),
A repeating unit represented by the following general formula (II), a repeating unit represented by the following general formula (III), a repeating unit represented by the following general formula (IV), a repeating unit represented by the following general formula (V) and at least one cyclic olefin-derived repeating unit (b) selected from the group consisting of repeating units represented by the following general formula (VI);
The method for manufacturing an optical member according to any one of claims 1 to 4, comprising:

(In the general formula (I), R ³⁰⁰ represents a hydrogen atom or a linear or branched hydrocarbon group having 1 to 29 carbon atoms.)

(In the general formula (II), u is 0 or 1, v is 0 or a positive integer, w is 0 or 1, and R ⁶¹ to R ⁷⁸ and R ^a1 and R ^b1 are the same hydrogen atom, halogen atom, alkyl group having 1 to 20 carbon atoms, halogenated alkyl group having 1 to 20 carbon atoms, cycloalkyl group having 3 to 15 carbon atoms, or 6 carbon atoms ~20 aromatic hydrocarbon groups, and R ⁷⁵ to R ⁷⁸ may be bonded to each other to form a monocyclic or polycyclic ring.)

(In the general formula (III), x and d are 0 or an integer of 1 or more, y and z are 0, 1 or 2, and R ⁸¹ to R ⁹⁹ may be the same or different from each other, A hydrogen atom, a halogen atom, an aliphatic hydrocarbon group which is an alkyl group having 1 to 20 carbon atoms or a cycloalkyl group having 3 to 15 carbon atoms, an aromatic hydrocarbon group having 6 to 20 carbon atoms, or an alkoxy group. The carbon atom to which R ⁸⁹ and R ⁹⁰ are bonded, the carbon atom to which R ⁹³ is bonded, or the carbon atom to which R ⁹¹ is bonded may be directly or an alkylene group having 1 to 3 carbon atoms. When y=z=0, R ⁹⁵ and R ⁹² or R ⁹⁵ and R ⁹⁹ may be bonded to each other to form a monocyclic or polycyclic aromatic ring. good.)

(In the general formula (IV), n and m each independently represent 0, 1 or 2, q represents 1, 2 or 3, and R ¹⁸ to R ³¹ each independently represent a hydrogen atom or a fluorine atom. A hydrocarbon group having 1 to 20 carbon atoms which may be substituted with a halogen atom excluding a fluorine atom, or a halogen atom excluding a fluorine atom, and when q=1, R ²⁸ and R ²⁹ , R ²⁹ and R ³⁰ , R ³⁰ and R ³¹ may be combined with each other to form a monocyclic or polycyclic ring, and when q=2 or 3, R ²⁸ and R ²⁸ , R ²⁸ and R ²⁹ , R ²⁹ and R ³⁰ , R ³⁰ and R ³¹ , R ³¹ and R ³¹ may be bonded to each other to form a monocyclic ring or a polycyclic ring, and the monocyclic ring or the polycyclic ring may be an aromatic ring.)

(In the general formula (V), R ¹⁰⁰ and R ¹⁰¹ may be the same or different and represent a hydrogen atom or a hydrocarbon group having 1 to 5 carbon atoms, and f is an integer of 1≦f≦18. )

(In the general formula (VI), q is 1, 2 or 3, and R ³² to R ³⁹ are each independently substituted with a hydrogen atom, a halogen atom excluding a fluorine atom, or a halogen atom excluding a fluorine atom) When q=1, R ³⁶ and R ³⁷ , R ³⁷ and R ³⁸ , and R ³⁸ and R ³⁹ are bonded to each other to form a monocyclic or polycyclic ring. Also, when q=2 or 3, R ³⁶ and R ³⁶ , R ³⁶ and R ³⁷ , R ³⁷ and R ³⁸ , R ³⁸ and R ³⁹ , and R ³⁹ and R ³⁹ combine with each other to form a single (The monocyclic ring or the polycyclic ring may have a double bond, and the monocyclic ring or the polycyclic ring may be an aromatic ring.) The repeating unit (b) derived from the cyclic olefin in the copolymer is bicyclo[2.2.1]-2-heptene, tetracyclo[4.4.0.1 ^2,5 . 1 ^7,10 ]-3-dodecene and benzonorbornadiene. The method for producing an optical member according to claim 5, comprising a repeating unit derived from at least one compound selected from the group consisting of 1 7,10 ]-3-dodecene and benzonorbornadiene. The method for producing an optical member according to claim 5 or 6, wherein the olefin-derived repeating unit (a) in the copolymer includes a repeating unit derived from ethylene.

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