JP6791036B2 - Resin optical parts and their manufacturing methods - Google Patents

Description

The present invention relates to a resin optical component having a resin base material and a film formed on the resin base material, and a method for manufacturing the same.

Optical components such as lenses and mirrors are composed of, for example, a glass base material and a functional film formed on the base material. In recent years, replacement of a glass base material with a resin base material has been studied in order to improve the degree of freedom in shape, reduce the weight, reduce the cost of raw materials, and the like.

As an optical component having a resin base material and a film formed on the resin base material, for example, Patent Document 1 describes an antireflection film in which a plurality of layers such as a layer containing silica-based fine particles are formed on the surface of the base material film. It is disclosed.

JP-A-2009-198863

However, it cannot be said that the conventional optical component having the resin base material and the film formed on the surface thereof has sufficient adhesiveness between the base material and the film. That is, since the resin has a higher coefficient of linear expansion than glass, the resin base material is easily deformed in a high temperature region. Therefore, when a film is formed on the resin base material, a large thermal stress is applied to the film in a high temperature environment, and cracks may occur.

Further, in a high humidity environment, the resin base material may absorb water and swell. Therefore, the film may be locally subjected to tensile stress due to the swelling of the resin base material, and the film may peel off as the resin base material shrinks.

The present invention has been made in view of the above problems, and will provide a resin optical component and a method for manufacturing the same, which have high adhesion between a resin base material and a film and can prevent the film from peeling or cracking. Is to be.

One aspect of the present invention includes a resin base material (2) and
A film (3) containing a metal oxide formed on the surface of the base material and
It has a linking molecular chain (4) that connects the base material and the film.
The connecting molecular chain has a structure represented by the following formula 1, the N-terminal in the following formula 1 forms a covalent bond with the carbon atom of the hydrocarbon skeleton in the base material, and the O-terminal in the following formula 1 Is in the resin optical component (1), which forms a covalent bond with the metal atom in the film.

In the above formula 1, A represents an arbitrary divalent linking group or a direct bond, and R ¹ represents hydrogen or an alkyl group having 1 to 6 carbon atoms.

Another aspect of the present invention, a surface treatment agent containing the linking molecule (401) having a triazine ring and a an alkoxy silyl group or silanol group and an azide group having 1 to 6 carbon atoms bonded to (40) made of resin Adhere to the base material (2)
The adhering surface (21) of the surface treatment agent is irradiated with ultraviolet rays to obtain
A method for manufacturing a resin optical component (1), which forms a film (3) containing a metal oxide on the adhesion surface by dipping, spray coating, vacuum deposition, sputtering, plasma CVD method, or atomic layer deposition method. It is in.

The resin optical component has a connecting molecular chain that connects the base material and the coating film, and the connecting molecular chain forms a covalent bond with the base material and the coating film, respectively. That is, the base material and the film are bonded by a strong chemical bond called a covalent bond via a linking molecular chain. Therefore, the resin optical component has high adhesion between the base material and the film. Therefore, even if it is exposed to a high temperature environment or a high humidity environment, peeling of the film and occurrence of cracks can be prevented.

In the above production method, a surface treatment agent containing a linking molecule having the specific structure is attached to a resin base material. At this time, the linking molecule is easily sufficiently close to the hydrocarbon skeleton of the base material and can be adsorbed on the surface of the base material. It is considered that this is because the triazine ring of the linking molecule contains an electron-withdrawing nitrogen atom and has an asymmetric structure about the central vertical line in the ring plane, so that it has a complex electron uneven distribution state around the molecule. ..

Next, the surface to which the surface treatment agent is attached is irradiated with ultraviolet rays. As a result, nitrogen molecules are eliminated from the azide group bonded to the triazine ring and nitrate is generated. During the formation of nitrene, as described above, since the linking molecule is adsorbed on the surface of the base material, a covalent bond is formed between the nitrene derived from the azide group of the linking molecule and the hydrocarbon skeleton of the base material.

Next, a film containing a metal oxide is formed on the adhesion surface. As a result, a covalent bond called Si—OM is formed between the silicon in the silanol group or the alkoxysilyl group of the linking molecule and the metal atom M in the metal oxide.

As described above, in the above-mentioned production method, the base material and the film can be covalently bonded via the linking molecular chain. Therefore, it is possible to manufacture a resin optical component which has excellent adhesion between the base material and the film and can prevent the film from peeling and cracking.

As described above, according to the above aspect, it is possible to provide a resin optical component and a method for manufacturing the same, which have high adhesion between the resin base material and the film and can prevent the film from peeling or cracking.
The reference numerals in parentheses described in the scope of claims and the means for solving the problem indicate the correspondence with the specific means described in the embodiments described later, and limit the technical scope of the present invention. It's not a thing.

FIG. 5 is a cross-sectional view of the resin optical component of the first embodiment. FIG. 3 is an enlarged cross-sectional view of a main part of the resin optical component of the first embodiment. The explanatory view which shows the connecting molecular chain which connects the base material and the film in the resin optical component of Embodiment 1. FIG. In the first embodiment, (a) an enlarged cross-sectional view of a main part of a base material to which a surface treatment agent is attached, and (b) an explanatory view showing a state in which ultraviolet rays are irradiated to the adhered surface of the base material. An explanatory diagram showing (a) a base material to which a linking molecule is adsorbed, and (b) an explanatory view showing a base material to which a linking molecule is covalently bonded in the first embodiment. In the first embodiment, (a) a diagram showing one form of an uneven distribution state of electrons in an azide group in a linking molecule, (b) a diagram showing another form of an uneven distribution state of electrons in an azide group in a linking molecule, (c) a link. The figure which shows the nitrate generated from the azide group in a molecule. FIG. 5 is a cross-sectional view of a resin optical component according to a second embodiment.

(Embodiment 1)
The resin optical component and the embodiment relating to the manufacturing method thereof will be described with reference to FIGS. 1 to 6. As illustrated in FIGS. 1 and 2, the resin optical component 1 has a base material 2 and a film 3.

The base material 2 is made of resin and has a hydrocarbon skeleton. The base material 2 contains, for example, a cyclic olefin resin, an acrylic resin, a polycarbonate resin, a polyethylene resin, a polypropylene resin, an acrylonitrile butadiene styrene, and the like. The base material 2 may contain one kind of resin, or may contain two or more kinds of resins. The shape of the base material 2 is not particularly limited, and can have a shape suitable for various optical components.

The film 3 is formed on the surface of the base material 2. The film 3 may cover the entire surface of the base material 2 or may partially cover the surface of the base material 2. The film 2 is, for example, a functional film capable of imparting a specific function to the base material or enhancing the function.

The film 3 contains a metal oxide. The film 3 may have one layer or may have a multi-layer structure of two or more layers as illustrated in the second embodiment described later. In the case of two or more layers, for example, the materials may be different from each other, or the same layer may be included.

As illustrated in FIG. 3, the resin optical component 1 has a linking molecular chain 4 that connects the base material 2 and the film 3. That is, the connecting molecular chain 4 crosslinks the base material 2 and the film 4. The linking molecular chain 4 may have the structure exemplified in FIG. 3, but may have a structure represented by the following formula 1.

In formula 1, R ¹ represents hydrogen or an alkyl group having 1 to 6 carbon atoms. If the carbon number of R ¹ exceeds 6, production becomes difficult. Further, in this case, it may be difficult to dissolve the linking molecule described later in a solvent such as alcohol at the time of production. R ¹ depends on the solvent that dissolves the linking molecule during production. When, for example, ethanol is used as the solvent, R ¹ is an ethyl group, and when, for example, propanol is used, R ¹ is a propyl group.

In formula 1, A represents any divalent linking group or direct bond. When A is a direct bond, Equation 1 is represented by Equation 1a below.

Examples of the linking group include an alkylene group. The alkylene group may be linear or have a branched chain. Further, the alkylene group may contain an ether, an amine, a carboxy group, a sulfide group, a ketone and the like.

A in the formula (1) is preferably the following formula 2. In this case, the synthesis of the linking molecule becomes easy.

In formula 2, R ² is an alkylene group having 1 to 6 carbon atoms. The alkylene group may be linear or may have a branched chain. The alkylene group is preferably a propylene group having 3 carbon atoms. In this case, the synthesis of the linking molecule becomes easier.

FIG. 3 shows an example of a linked molecular chain represented by the formula 1. As illustrated in FIG. 3, in the resin optical component 1, the N-terminal of the connecting molecular chain 4 represented by the formula 1 forms a covalent bond with the carbon atom of the hydrocarbon skeleton in the base material 2. .. The N-terminus is the nitrogen atom in the amino group linked to the triazine ring. This amino group is derived from, for example, an azide group.

Further, in the resin optical component 1, the O-terminal of the connecting molecular chain 4 represented by the formula 1 forms a covalent bond with a metal atom such as Si in the film 3. The O-terminal is an oxygen atom in a silanol group or an alkoxysilyl group directly or indirectly bonded to the triazine ring.

As the metal oxide in the film 3, at least one selected from Si, Ti, Ta, Nb, Zr, Al, Mg and the like can be contained. The metal oxide may be an oxide containing one kind of metal atom or a composite oxide containing two or more kinds of metals.

Preferably, the metal oxide of the film 3 may contain at least one of Si and Ti. When the metal oxide contains Si, the film 3 and the linking molecular chain 4 are linked by a siloxane bond (that is, −Si—O—Si−). When the metal oxide contains Ti, the film 3 and the linking molecular chain 4 are linked by a −Ti—O—Si− bond. In either case, the bond between the base material 2 and the film 3 via the linking molecular chain 4 becomes stronger, and peeling and cracking of the film 3 can be further prevented. Note that FIG. 3 illustrates a case where the film 3 and the linking molecular chain 4 are linked by a siloxane bond.

The resin optical component 1 can have, for example, at least one of an antireflection film and an antireflection film as the film 3. When the film 3 made of an antireflection film is provided, the resin optical component 1 is suitable for a camera lens, a display, or the like used for, for example, various sensors. When the film 3 made of a reflective film is provided, the resin optical component 1 is suitable for, for example, a mirror.

The antireflection film can contain a metal oxide having a high bending rate of, for example, 2.0 or more. Examples of such metal oxides include Ta ₂ O ₅ , ZrO ₂ , TiO ₂ , Nb ₂ O _{5, and the} like.

The hyperreflective film can contain a metal oxide having a low bending rate of, for example, less than 2.0. Examples of such metal oxides include SiO ₂ , Al ₂ O ₃ , MgO, Y ₂ O _{3 and the} like.

Next, a method of manufacturing the resin optical component 1 will be described. First, as illustrated in FIG. 4A, the surface treatment agent 40 is attached to the surface of the resin base material 2. The surface treatment agent 40 can be adhered by dipping (that is, dipping) the base material 2 in the surface treatment agent 40, spray coating, or the like.

The surface treatment agent 40 contains a linking molecule and a solvent that dissolves the linking molecule. Linking molecule, having a triazine ring and a an alkoxy silyl group or silanol group and an azide group having 1 to 6 carbon atoms bonded. As the linking molecule, for example, a substance represented by the following formula 3 can be used. In formula 3, A and R ¹ are the same as those in formula 1 described above.

As the solvent, alcohols such as methanol, ethanol, propanol and butanol can be used. In addition, water, acetone, benzene, toluene, xylene and the like can be used. It is preferable to use a lower alcohol as the solvent.

For example, an example will be described in which ethanol is used as the solvent, and a substance in which A in the formula 3 is −NHCH ₂ CH ₂ CH ₂ − and R ¹ is an ethyl group (that is, −CH ₂ CH ₃ ) is used as the linking molecule. .. That is, an example in which a substance represented by the following formula 3a is used as the linking molecule will be described.

When the surface treatment agent 40 is attached to the base material 2, as illustrated in FIG. 5A, the linking molecule 401 contained in the surface treatment agent 40 is close to the hydrocarbon skeleton of the base material 2, and the base material It can be adsorbed on the surface of 2. This is because the triazine ring of the linking molecule 401 contains an electron-withdrawing nitrogen atom and has an asymmetric structure about the central vertical line in the ring plane, so that it has a complex electron uneven distribution state around the molecule. is there. Then, as illustrated in FIGS. 6 (a) and 6 (b), the azide group bonded to the triazine ring has polarity. Therefore, even when the base material 2 contains a resin having a small polarity such as a polyethylene resin or a polypropylene resin, the linking molecule 401 is connected to a small polar portion between the carbon atom and the hydrogen atom in the hydrocarbon skeleton. Can be adsorbed. That is, the linking molecule 401 can be adsorbed on the base material 2 having a hydrocarbon skeleton.

Next, as illustrated in FIG. 4B, the adhesion surface 21 of the surface treatment agent 40 is irradiated with ultraviolet rays Hv. As a result, as illustrated in FIG. 6 (c), nitrogen molecules are eliminated from the azide group bonded to the triazine ring and nitrate is produced. At this time, since the linking molecule 401 is adsorbed on the surface of the base material 2 as illustrated in FIGS. 5A and 5B, the hydrocarbon derived from the azide group of the linking molecule 401 and the base material 2 A covalent bond is formed with the hydrocarbon skeleton of.

FIGS. 5A and 5B show an example in which a covalent bond is formed between one azide group of the linking molecule 401 and the carbon atom of the hydrocarbon skeleton in the base material 2. The linking molecule 401 can also have both of its two azide groups forming a covalent bond with the carbon atom in the substrate 2.

Next, a film 3 containing a metal oxide is formed on the adhesion surface 21. The method for forming the film 3 is not particularly limited, and the film 3 can be formed by dipping, spray coating, vacuum deposition, sputtering, plasma CVD method, ALD (that is, atomic layer deposition) or the like. Vacuum vapor deposition is preferable.

For example, an example in which a film 3 containing silicon oxide is formed on the adhesion surface 21 will be described below. As illustrated in FIG. 5B, since the linking molecule 401 is bonded to the bonding surface 21, the film 3 is formed on the bonding surface 21 to which the linking molecule 401 is bonded. At this time, as illustrated in FIG. 3, a covalent bond such as a siloxane bond is formed between the Si atom in the silicon oxide in the film 3 and the alkoxysilyl group of the linking molecule 401.

Although not shown, when titanium oxide is used instead of silicon oxide, a Ti—O—Si bond is formed between the Ti atom of titanium oxide in the film and the alkoxysilyl group of the linking molecule. Even when the film contains an oxide of another metal atom M instead of silicon oxide or titanium oxide, an M—O—Si bond can be formed.

In this way, as illustrated in FIG. 3, the base material 2 and the film 3 are connected via the connecting molecular chain 4, and the resin optical component 1 can be obtained. Note that FIG. 3 shows an example in which the Si atom of the linking molecular chain 4 forms a covalent bond with the Si atom in the film 3 via one oxygen atom. The linked molecular chain 4 can also form a covalent bond between the Si atom and the two or more Si atoms in the film 3 via the other two or more oxygen atoms bonded to the Si atom.

In the resin optical component 1, as illustrated in FIGS. 1 to 3, the base material 2 and the film 3 are covalently bonded via the connecting molecular chain 4. Therefore, the adhesion between the base material 2 and the film 3 is excellent. Therefore, even if it is exposed to a high temperature environment or a high humidity environment, it is possible to prevent peeling and cracking of the film 3.

Such a resin optical component 1 is suitable for, for example, in-vehicle use, which is easily exposed to a high temperature environment or a high humidity environment. When the resin optical component 1 has, for example, an antireflection film as the film 3, the resin optical component 1 is suitable for a lens of an in-vehicle sensor camera. Further, when the resin optical component 1 has, for example, a reflective film as the film 3, the resin optical component 1 is suitable for an in-vehicle mirror.

(Experimental example)
This example is an example of evaluating the adhesive strength of a resin optical component. First, the resin optical component according to the embodiment was manufactured in the same manner as in the first embodiment. The resin optical component of the embodiment has the same configuration as that of the first embodiment. In the production of the resin optical component of the example, a molecule represented by the formula 3a was used as a linking molecule, and a film was formed by vacuum vapor deposition of silicon oxide.

Further, for comparison of the examples, a resin optical component in which a film containing silicon oxide was formed on the base material was produced without using a surface treatment agent. The resin optical component of this comparative example can be obtained in the same manner as in the examples except that a surface treatment agent is not used.

After the resin optical components of Examples and Comparative Examples were left to stand in a high temperature and high humidity environment with a relative humidity of 85% for 1000 hours, a tape peeling test was performed on each resin optical component. Specifically, first, three types of tapes having different adhesive strengths were attached to the coating film of the resin optical component. The adhesive surface between the tape and the film is a 5 mm square area. In addition, a push-pull gauge "SV3" manufactured by Imada Seisakusho Co., Ltd. was attached to the end of the tape. Then, the adhesion strength (unit: N / 5 mm) when the tape was peeled off from the resin optical component was measured by a push-pull gauge.

In the comparative example, the film was peeled off with all three types of tapes. Of these, the adhesion strength when the peeling test was performed using the tape having the weakest adhesion was 0.1 N / 5 mm.

On the other hand, in the examples, the film did not peel off even if any of the three types of tapes was used. Of these, the adhesion strength was 1.2 N / 5 mm when the peeling test was performed using the tape having the strongest adhesion strength.

That is, in the example having the linking molecular chain between the base material and the film, the adhesion was improved by at least 12 times as compared with the comparative example not having the linking molecular chain. Moreover, when the resin optical parts of the examples left in a high temperature and high humidity environment were visually observed, no cracks were generated or peeled off.

As described above, according to this example, it can be seen that the adhesion is improved by bringing the base material and the film into close contact with each other via the connecting molecular chain as in the first embodiment. A resin optical component having such a connecting structure can exhibit excellent adhesion even in a high temperature and high humidity environment.

(Embodiment 2)
In this embodiment, a resin optical component having a multi-layered film will be described. As illustrated in FIG. 7, the resin optical component 1 can have a film 3 having a multilayer structure. In addition, among the codes used in the second and subsequent embodiments, the same codes as those used in the above-described embodiments represent the same components and the like as those in the above-mentioned embodiments, unless otherwise specified.

When the film 3 has a multi-layer structure, the film 3 preferably contains silicon oxide or titanium oxide and has a first layer 31 facing the base material 2. That is, it is preferable that the first layer in contact with the base material 2 has silicon oxide or titanium oxide. In this case, the linking molecular chain 4 and the first layer 31 are bonded by a Si—O—Si bond or a Si—O—Ti bond, so that the adhesion is further improved.

Further, it is preferable to have the second layer 32 containing tantalum oxide. In this case, a chemically stable and amorphous film is likely to be formed, and the effect of preventing the permeation of molecules such as water into the gaps between the films can be obtained. The second layer 32 can be formed on the first layer 31. As illustrated in FIG. 7, the second layer 32 faces the first layer 31, and the first layer 31 and the second layer 32 can be brought into direct contact with each other. Further, another layer (not shown) may be provided between the first layer 31 and the second layer 32.

In the example of FIG. 7, the film 3 having a two-layer structure is shown, but the film 3 may have three or more layers. When forming a multi-layered film 3, the film 3 is, for example, an ultraviolet (that is, UV) cut filter, an infrared (that is, IR) cut filter, and hydrophilic water repellent, in addition to the above-mentioned antireflection film and antireflection film. It can contain a film, a hard coat film, and the like.

Although the embodiments of the present invention have been described above, the present invention is not limited to each of the above embodiments, and can be applied to various embodiments without departing from the gist thereof.

1 Resin optical component 2 Base material 3 Film 4 Linked molecular chain 40 Surface treatment agent 401 Linked molecule

Claims (18)

Resin base material (2) and
A film (3) containing a metal oxide formed on the surface of the base material and
It has a linking molecular chain (4) that connects the base material and the film.
The connecting molecular chain has a structure represented by the following formula 1, the N-terminal in the following formula 1 forms a covalent bond with the carbon atom of the hydrocarbon skeleton in the base material, and the O-terminal in the following formula 1 Is a resin optical component that forms a covalent bond with the metal atoms in the film.

In the above formula 1, A represents an arbitrary divalent linking group or a direct bond, and R ¹ represents hydrogen or an alkyl group having 1 to 6 carbon atoms. The resin optical component according to claim 1, wherein A in the above formula 1 is the following formula 2.

R ² in the above formula 2 is an alkylene group having 1 to 6 carbon atoms. The resin optical component according to claim 2, wherein the alkylene group in the above formula 2 is a propylene group. Claim 1 in which the metal oxide in the film contains at least one of Si and Ti, and the O-terminal of the connecting molecular chain forms a covalent bond with the Si atom or Ti atom of the metal oxide. The resin optical component according to any one of 3 to 3. The resin optical component according to any one of claims 1 to 4, wherein the film contains at least one of an antireflection film and an antireflection film. The resin optical component according to any one of claims 1 to 5, wherein the film has a multilayer structure. The resin product according to claim 6, wherein the film contains at least a first layer (31) containing silicon oxide or titanium oxide and facing the base material, and a second layer (32) containing tantalum oxide. Optical parts. The resin optical component according to any one of claims 1 to 7, wherein the resin optical component is an in-vehicle lens or mirror. Surface treatment agent (40) is attached to the resin base material (2) containing a linking molecule (401) having a triazine ring and a an alkoxy silyl group or silanol group and an azide group having 1 to 6 carbon atoms bonded ,
The adhering surface (21) of the surface treatment agent is irradiated with ultraviolet rays to obtain
A method for manufacturing a resin optical component (1), which forms a film (3) containing a metal oxide on the adhesion surface by dipping, spray coating, vacuum deposition, sputtering, plasma CVD method, or atomic layer deposition method. .. The method for manufacturing a resin optical component according to claim 9, wherein the linking molecule is represented by the following formula 3.

In the above formula 3, A represents an arbitrary divalent linking group or a direct bond, and R ¹ represents hydrogen or an alkyl group having 1 to 6 carbon atoms. The method for manufacturing a resin optical component according to claim 10, wherein A in the above formula 3 is the following formula 2.

R ² in the above formula 2 is an alkylene group having 1 to 6 carbon atoms. The method for manufacturing a resin optical component according to claim 11, wherein the alkylene group in the above formula 2 is a propylene group. The method for producing a resin optical component according to any one of claims 9 to 12, wherein the surface treatment agent contains the linking molecule and an alcohol that dissolves the linking molecule. The method for manufacturing a resin optical component according to any one of claims 9 to 13, wherein the surface treatment agent is attached to the base material by dipping or spraying. The method for manufacturing a resin optical component according to any one of claims 9 to 14, wherein at least one of an antireflection film and an antireflection film is formed as the film. The method for manufacturing a resin optical component according to any one of claims 9 to 15, wherein a film having a multilayer structure is formed as the film. Claims 9 to 16, wherein at least a first layer (31) containing silicon oxide or titanium oxide and facing the base material and a second layer (32) containing tantalum oxide are formed as the film. The method for manufacturing a resin optical component according to any one item. The method for manufacturing a resin optical component according to any one of claims 9 to 17, wherein the film is formed by vapor deposition of the metal oxide.

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