JPH0493375A - Coating material - Google Patents

Abstract

PURPOSE:To obtain a coating material giving a coating film highly adhesive to inorg. and plastic materials without the necessity for thermal curing process by using a specified polyhydroxy-polyether resin. CONSTITUTION:A coating material is prepd. by using a polyhydroxy-polyether resin constituted of the structural units of formula I (wherein X and Y are each halogen or CH3, R is a direct linkage or a divalent group, and p and q are each 0-4), e.g. the resins of formulas II and III. The coating material can form a coating film having a high adhesion to inorg. materials and plastics without the necessity for thermal cure. It is successfully usable as optical thin film such as antireflection coating, semi-transparent film, selective absorption film and the like, or as underlying film of optical thin films, or as water absorption reducing film for optical parts, or as a hard coat.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a specific coating material. The coating material provided by the present invention is preferably used for optical thin films such as anti-reflection films, translucent films, selective absorption films, subbing films for optical thin films, low water absorption films for optical parts, etc., or hard coats. be done. Optical thin films, subbing films for optical thin films, low water absorption films for optical components, and hard coats obtained from the coating material of the present invention have excellent adhesion to inorganic materials, plastics, and the like.

[Conventional technology] Light transmittance, surface hardness, water absorption,
A thin film made of an inorganic or organic material such as a dielectric may be formed on the surface of the above-mentioned inorganic material or plastic for the purpose of improving properties such as adhesion with other materials. For example, in cameras, projection televisions, video cameras, etc., which have optical systems made up of many optical parts such as lenses and filters, the entire optical system is The light transmittance of the lens is significantly reduced, and flare and ghosting occur. To prevent these, the surfaces of optical components are coated with MgF2, S! An antireflection film made of 02, A 1201, or the like is formed. In addition, the efficiency with which solar cells utilize light rays decreases due to reflection on their surfaces. To prevent this, an antireflection film is formed on the surface of the solar cell [see Optical Thin Film, Kyoritsu Shuppan (1985)].

On the other hand, due to water absorption (moisture absorption), a low water absorption film made of an organic material such as the structure of the optical component or an inorganic material such as St, N, etc., may be formed on the surface of the optical component. Also,
In order to prevent scratches from occurring on the surface of an optical component, a hard coat made of a highly hard organic material such as melamine resin is sometimes formed on the surface.

Made from specific silane compounds that have high adhesion between a substrate made of an inorganic material such as glass or plastic and the above-mentioned antireflection film, low water absorption film, hard coat, etc. formed on the substrate. It may be coated with a subbing film.

[Problem to be solved by the invention] MgF, SiO□, used as an antireflection film, etc.
Since the coefficient of thermal expansion of inorganic materials such as AI, O, etc. is about an order of magnitude smaller than that of plastics, when a coating material made of the above-mentioned inorganic materials is formed on the surface of plastics, distortion occurs during heating. This may cause cracks in the coating material. Also,
Since the water absorption rate of the above-mentioned inorganic materials is much lower than that of plastics, cracks may similarly occur in the coating material due to changes in humidity. Usually, the above-mentioned inorganic materials are coated onto plastics by vacuum evaporation, sputtering, ion blating, etc., but these methods require expensive vacuum equipment, which can increase manufacturing costs. This is unavoidable, and plastic has low heat resistance.
It is necessary to set film formation conditions so that the temperature of the plastic does not rise during film formation. For the above reasons, it is desirable to form a coating material made of an organic material on the plastic surface.1. stomach. In addition, coating materials made of organic materials can be coated using a simple method such as spin-coating, and manufacturing costs can be lowered. It is desirable to use it as a coating material.

A high refractive index undercoating film formed between a plastic substrate and an antireflection film, which has high hardness and high adhesion to the plastic and antireflection film, is made from a specific hexamethoxymethylolmelamine. A coating material is known (see Japanese Patent Publication No. 61-48123). In order to form a coating material made of the hexamethoxymethylol melamine, the hexamethoxymethylol melamine is applied onto a plastic substrate and then heated at a high temperature of, for example, 130° C. for 4 hours.
Since a long heat curing process is required, the above-mentioned coating material cannot be used as an undercoat film on a substrate made of a plastic with poor heat resistance, such as polymethyl methacrylate.

An object of the present invention is to provide a coating material that provides a film having high adhesion to inorganic materials and plastics without requiring a heat curing step.

[Means for Solving the Problems] According to the present invention, the above object is achieved by the following general formula ([) [wherein X and Y each represent a halogen atom or a methyl group, and R represents a bond or a divalent represents a group, and p and q each represent an integer of O to 4. This is achieved by providing a coating material characterized by containing a polyhydroxypolyether resin consisting essentially of the structural unit represented by ().

Examples of the halogen atom represented by X and Y in the above general formula (I) include a chlorine atom, a bromine atom, and the like. Furthermore, examples of the divalent group represented by R include the following.

CH- CH3 CH.

CH3 CH.

Examples of the group represented by C- C to C- c, H9 C to C- include the following formulas (n) to (X
Examples include those shown in ■).

-Constituting the structural unit represented by Formula (I) Formula (E') - Hq CH9 Among these, the above formula (n) (III) (r'
The coating material of the present invention containing a polyhydroxy polyether resin having a group represented by /), (V) or (IX) as a part of the structural unit is particularly suitable for CH.

It has a high refractive index and is suitably used for optical thin films such as antireflection films, translucent films, and selective absorption films, and for subbing films for optical thin films. The above formulas (n), (III), (
The coating material of the present invention containing a polyhydroxy polyether resin having a group represented by IX), (X) or (Kl) as a part of the structural unit has particularly high hardness and is suitable for hard coats. used for. Also, the above formulas (I[), (■), (IX), (X), (XI)
The coating material of the present invention, which contains a polyhydroxy polyether resin having a group represented by , (IN) or (xl) as a part of its structural unit, has a particularly low water absorption rate, and is useful for reducing water absorption of optical components. Suitable for use in membranes.

The polyhydroxy polyether resin constituting the coating material of the present invention is produced according to a known general synthesis method for polyhydroxy polyether resin using bisphenols corresponding to the structural unit represented by general formula (1) and epichlorohydrin. Manufactured. The polyhydroxy polyether resin used in the present invention includes a copolymer obtained from two or more types of bisphenols corresponding to the structural unit represented by the general formula (1), and a copolymer obtained from the structural unit represented by the general formula (1). Also mentioned are mixtures of two or more polyhydroxy polyether resins. The polyhydroxy polyether resin used in the present invention may contain, for example, hydroquinone, within a range that does not impair its properties.
It may also contain a structural unit derived from a diol such as 2.6-naphthalenediol.

Methods for coating the surface of a substrate such as glass or plastic with the coating material of the present invention include a spin-coating method using a solution obtained by dissolving the polyhydroxy polyether resin constituting the coating material of the present invention in a solvent, and a spray method. The dry method and the dipping method are preferable because a film having a uniform thickness can be easily obtained. As the above-mentioned solvent, toluene, tetrahydrofuran, dioxane, methylene chloride, chloroform, dimethyl sulfoxide, dimethyl alumamide, ethyl acetate, acetone, cyclohexanone, methanol, ethanol, or a mixed solvent of two or more of these can be used.

The coating material of the present invention is suitably used for optical thin films such as antireflection films, subbing films for optical thin films, low water absorption films for optical components, hard coats, and the like. When using the coating material of the present invention for an antireflection film, if the substrate is made of plastic or glass and the refractive index of the substrate is 1.7 or less, the coating material of the present invention is applied on the substrate. A resin film made of polyalkyl acrylate, polyalkyl methacrylate, fluoroalkyl polyacrylate, polyfluoroalkyl methacrylate, polyalkyl vinyl ether, polyolefin, etc. having a lower refractive index than the coating material is coated on the coating material layer. By laminating them, a sufficient antireflection effect can be obtained. When the substrate is made of silicon, germanium, a compound semiconductor, etc., and the substrate has a refractive index of 3 or more, the coating material of the present invention has a high refractive index. A sufficient antireflection effect can be obtained by forming an antireflection film consisting of a coating material layer of. The polyhydroxy polyether resin constituting the coating material of the present invention is 1.5 to 1.7
By using a copolymer obtained from two or more types of bisphenols or a mixture of two or more types of polyhydroxy polyether resin as the polyhydroxy polyether resin, the desired A coating material having a refractive index that achieves an antireflection effect is obtained.

When the coating material of the present invention is used as an undercoat film for an optical thin film, it is preferable to select and use a coating material of the present invention having a refractive index similar to that of the base material. This is preferable in that flare caused by the difference in refractive index between the two is reduced.

The properties of the coating material of the present invention can be improved by adding antioxidants, stabilizers such as ultraviolet absorbers, dyes, pigments, antistatic agents, lubricants, etc., as necessary. When it is necessary to form irregularities on the surface of the coating layer made of the coating material of the present invention, it is preferable to perform heat embossing after coating.

[Example] Hereinafter, the present invention will be specifically explained with reference to Examples.

In addition, in the cross-cut cellophane tape peeling test in the examples, 11
A book cut is formed on the membrane, creating a total of 100 basic eyes,
The test was carried out by pasting Cero/X-n tape on the membrane, peeling it off rapidly, and counting the number of base lines from which the membrane was peeled off.

Example 1 Structural unit below.

polyhydroxy polyether resin (refractive index 1.
64) in tetrahydrofuran, and the resulting solution was subjected to a spin coding method to obtain a cross-linked acrylic resin plate having a transmittance of 92.3% for light with a wavelength of 550 nm [■ Paralinks TS-20 (trade name) manufactured by Kuraray: Refractive index 1.
49] to a film thickness of 85 nm. Next, polymethacrylic acid 2,2,3,3-tetrafluoropropyl (refractive index 1.40) was dissolved in toluene, and the resulting solution was coated with the polyhydroxypolyether resin using the same spin-coding method. An antireflection film was formed on the material layer by laminating the film to a thickness of 1100 nm. The cross-linked acrylic resin plate on which the anti-reflection film is formed has a transmittance of 963 for light rays with wavelengths of 550 nm and 550 m.
%Met. When the cross-linked acrylic resin plate on which the anti-reflective film was formed was left for 120 hours at 60°C and 90% RH, it was subjected to a cross-cut cellophane tape peeling test, and no peeling of the anti-reflective film was observed. Ta.

Example 2 Structural unit below.

polyhydroxy polyether resin (refractive index 1.
65) in tetrahydrofuran, and the resulting solution was coated with a film thickness of 82 nm on a silicon substrate having a reflectance of 32.7% for light with a wavelength of 830 nm using a spin coding method.
An antireflection film was formed by coating the film to a thickness of nm. Wavelength 830 possessed by the silicon substrate on which the antireflection film is formed
The reflectance for nm light was 2.2%. The silicon substrate on which the anti-reflection film was formed was heated to 60°C and 90%RH.
After being left for 120 hours under these conditions, a cross-cut cellophane tape peeling test was performed, and no peeling of the antireflection film was observed. Moreover, the antireflection film had high hardness, and the pencil hardness was 3H.

Example 3 The following structural unit xane was dissolved, and the resulting solution was coated on a polycarbonate resin substrate [manufactured by Mitsubishi Gas Chemical ■, Nipilon (trade name) layer] to a film thickness of 5 μm using a spin coding method. Formed a hard coat.

When the polycarbonate resin substrate on which the hard coat was formed was left for 120 hours at 60° C. and 90% RH and then subjected to a cross-cut cellophane tape peeling test, no peeling of the hard coat was observed. Also, coat the surface of the hard coat with #0OOO steel wool (
When the surface was observed after being rubbed 20 times under a load of 1 kg, it was found that there were only slight scratches. on the other hand,
When the surface of a polycarbonate resin not coated with a hard coat was similarly rubbed, significant scratches were observed.

Example 4 A polyhydroxy polyether resin consisting of a polyhydroxy polyether resin consisting of the following structural units was dissolved in methylene chloride, and the resulting solution was diluted to a size of 50 mm by a dipping method.
Cross-linked acrylic resin plate with dimensions of X50mmX2mm [■ Baralinks TS-40 (product name) manufactured by Kuraray]
A low water absorption film was formed by coating the entire surface of the film to a thickness of 10 μm. Water absorption rate of the crosslinked acrylic resin plate on which the low water absorption film is formed (ASTM D570.23℃
, 24 hours) was 0.14%. On the other hand, the crosslinked acrylic resin plate not coated with the low water absorption film had a water absorption rate of 0.32%.

Example 5 A polyhydroxypolyether resin consisting of the following structural units was dissolved in tetrahydrofuran, and the resulting solution was prepared using a spin code method to prepare a cross-linked ac-1-nor resin plate [#a manufactured by Kuraray Co., Ltd., Baralinks TS-20 (trade name] ) A coating material layer was formed by coating 1 to a thickness of 5 μm. The crosslinked acrylic resin plate on which the coating material layer was formed was heated at 60°C and 90°C.
%RH for 120 hours and then subjected to a cross-cut cellophane tape peeling test, and no peeling of the antireflection film was observed.

Example 6 Structural unit below.

A polyhydroxypolyether resin consisting of the
A coating material layer was formed by coating S-20 (trade name) 1 to a thickness of 5 μm. Cross-linked acrylic resin plate with coating material layer formed at 60℃, 90%R
After leaving it for 120 hours under H conditions, cross-cut
When subjected to a cellophane tape peel test, no peeling of the antireflection film was observed.

Example 7 A polyhydroxy polyether resin consisting of the following structural units and a polyhydroxy polyether resin consisting of the following structural units were dissolved in tetrahydrofuran, and the resulting solution was processed into a crosslinked acrylic resin plate [■ Made by Kuraray, Paralinks T
S-20 (trade name)] to form a coating material layer to a thickness of 5 μm. Cross-linked acrylic resin plate with coating material layer formed at 60℃, 90%R
After leaving it for 120 hours under H conditions, cross-cut
When subjected to a cellophane tape peel test, no peeling of the antireflection film was observed.

Example 8 A cross-linked acrylic resin plate [■ Baralinks TS-20 (trade name, manufactured by Kuraray) was coated to a film thickness of 5 μm. 60 pieces of cross-linked acrylic resin plate with coating material layer formed on it
After leaving it for 120 hours at ℃ and 90% RH, it was subjected to a cross-cut cellophane tape peeling test.
No peeling of the antireflection film was observed.

Comparative Example 1 Silicon oxide (film thickness 82 nm, refractive index 1.68) and magnesium fluoride (film thickness 1100 nm, refractive index 1.38) were deposited on the same crosslinked acrylic resin plate as used in Example 1 by vacuum evaporation. ) was laminated with this layer to form an antireflection film.

The cross-linked acrylic resin plate on which the anti-reflection film is formed has a high transmittance of 96.2% for light with a wavelength of 550 nm.
However, when the cross-linked acrylic resin plate on which this anti-reflection film was formed was left at 60°C and 90% RH for 120 hours and then subjected to a cross-cut cellophane tape peeling test, 75 pieces peeled off. did.

Comparative Example 2 Poly 2,6-dichlorostyrene (refractive index 1.63) was coated on the same silicon substrate as used in Example 2 to a thickness of 125 nm by spin coding to form an antireflection film. Formed. The silicon substrate on which the anti-reflection film was formed had a low reflectance for light with a wavelength of 830 nm, which was 2.6%. After being left for a certain period of time, a cross-cut cellophane tape peeling test was performed, and 85 pieces were peeled off. Further, the surface hardness of this antireflection film was low, and the pencil hardness was HB.

[Effects of the Invention] According to the present invention, a coating material that provides a film having high adhesiveness to inorganic materials and plastics without requiring a heat curing step is provided.

Patent 8 patents Kuraray Co., Ltd. Representative Patent Attorney Ken Honda

Claims (1)

[Claims] The following general formula (I) (I): ▲ Numerical formulas, chemical formulas, tables, etc. ▼ [In the formula, X and Y each represent a halogen atom or a methyl group, and R represents a bond or a divalent represents a group, and p and q each represent an integer of 0 to 4. ] A coating material characterized by containing a polyhydroxy polyether resin consisting essentially of structural units represented by the following.