JPH0682604A - Optical element - Google Patents

Abstract

PURPOSE:To improve weatherability and to eliminate interference even if a high-refractive-index org. glass is used by interposing a primer layer formed with a specified coating material between the org. glass and a silicone cured coating layer. CONSTITUTION:A silicone cured coating film (hard coat) and an inorg. antireflection coating are laminated on the surface of an org. glass. A primer layer is interposed between the org. glass and hard coat. The primer layer consists of the coating material with a urethane elastomer, an inorg. fine particle and the hydrolysate of an organoalkoxysilane as the essential components. The urethane elastomer should be thermoplastic. A reactive component such as a polyamine is preferably added and partially crosslinked after coating. Metal oxides such as silicon oxide, iron oxide and titanium oxide are preferably used for the inorg. fine particle. Consequently, the refractive index of the primer layer is controlled to 1.40-1.70, and the primer layer is applicable to any org. glass.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to an organic glass surface,
The present invention relates to an optical element in which a silicone cured coating film (hard coat) and an inorganic antireflection film are laminated.

Here, the optical element means a lens, a cover for lighting equipment, a reflecting mirror, which is manufactured based on organic glass.
It is a concept that includes a prism, a filter, and the like.

The following description will be made by taking a spectacle lens as an example, but the present invention is not limited to this.

[0004]

2. Description of the Related Art In recent years, as a material for spectacle lenses, organic glass, which is lighter and less fragile than inorganic glass, has become widespread. However, in general, organic glass has markedly lower scratch resistance than inorganic glass.

Therefore, the surface of the lens usually has a silicone-based cured coating film (hereinafter referred to as "hard coat"). In addition, in the case of spectacle lenses, an inorganic antireflection film formed by dry plating such as vapor deposition of an inorganic substance has come to be provided on the lens for aesthetic reasons.

However, the lens having both the hard coat and the inorganic antireflection film on the organic glass substrate as described above has a problem that the impact resistance is poor.

Therefore, in order to improve the impact resistance of the hard coat, a technical idea of interposing a primer layer made of a polyurethane-based paint between the base material and the hard coat is disclosed (JP-A-63-87223).・ 63-141
001, JP-A-3-109502, etc.).

On the other hand, in recent years, an organic glass-based material is an aliphatic allyl carbonate type (CR-39, refractive index 1.5).
0) is being replaced by higher-refractive aromatic allyl carbonate type (refractive index 1.57), polythiourethane type (refractive index 1.60 to 1.70) and the like. In this case, the refractive index of the hard coat also prevents interference from light,
It should have the same refractive index as the base material.

[0009]

However, the refractive index of the primer layer made of the above urethane-based paint is 1.
Since it is around 50, light interference is inevitable even if the refractive index of the hard coat is made close to that of the base material. Further, in general, the urethane coating film is inferior in weather resistance even if it is a non-yellowing type, which is not desirable in the case of a spectacle lens which is often used outdoors.

In view of the above, an object of the present invention is to provide an optical element having a hard coat and an antireflection film, which has excellent weather resistance and causes optical interference even when the organic glass substrate has a high refractive index. It is to provide an optical element having a primer layer which is not allowed to be present between the organic glass and the hard coat.

[0011]

The inventors of the present invention have made extensive efforts to solve the above problems, and as a result, have completed the present invention having the following constitution.

In an optical element in which a hard coat and a single-layer or multi-layer inorganic antireflection film are laminated on the surface of an organic glass, the following components are essential active ingredients between the organic glass and the hard coat. An optical element having a primer layer formed of a paint interposed.

(A) Urethane elastomer (b) Inorganic fine particles (c) Hydrolyzate of organoalkoxysilane

[0014]

Detailed Description of Means Each means of the present invention will be described in detail below. In the following description, the mixing unit is a weight unit unless otherwise specified.

A. The optical element of the present invention is premised on that a hard coat and an inorganic antireflection film are laminated on the surface of organic glass.

(1) The organic glass substrate is not particularly limited as long as it is transparent and has a refractive index of 1.40 to 1.70. Examples of the base material include polymethyl methacrylate, polycarbonate, aliphatic allyl carbonate-based, aromatic allyl carbonate-based, and polythiourethane.

(2) The hard coat (silicone-based cured coating film) is not particularly limited as long as it is of silicone type. For example, a catalyst and metal oxide fine particles / composite fine particles are added to a hydrolyzate of an organoalkoxysilane, and a hard coat solution is prepared so that the viscosity can be appropriately applied with a diluting solvent. Further, agents such as an interfacial slip agent (leveling agent) and an ultraviolet absorber can be added to the hard coat liquid. The hard coat solution thus prepared is applied to a substrate by a conventional means and dried and cured to obtain a hard coat. The thickness of this hard coat is usually
It is 0.5 to 20 μm.

As the above-mentioned organoalkoxysilane, specifically, those represented by the general formula can be used.

R ¹ _a R ² _b Si (OR ³ ) _{4- (a + b)} (wherein R ¹ is an alkyl group having 1 to 6 carbon atoms, a vinyl group, an epoxy group, a methacryloxy group, a phenyl group, R
² is an alkyl group having 1 to 6 carbon atoms, a halogenated alkyl group, R ³ is an alkyl group having 1 to 4 carbon atoms, an alkoxyalkyl group, and a and b are 0, 1, 2 , A + b = 1, 2, or 3. ), More specifically, methyltrimethoxysilane, glycidoxymethyltrimethoxysilane, α-gilicidoxyethyltrimethoxysilane, β-glycidoxyethyltrimethoxysilane, γ-glycosideoxypropyltrimethoxysilane, etc. Can be mentioned. These may be used alone or in combination of two or more.

Examples of the catalyst include organic carboxylic acids such as trimellitic acid and trimellitic anhydride, titanium alkoxides, zirco alkoxides, silica alkoxides,
And the like, nitrogen-containing organic compounds such as methyl imidazole and dicyandiamide, metal complexes such as acetylacetone aluminum, and alkali metal organic carboxylates such as sodium acetate and potassium acetate.

As the above-mentioned diluent solvent, alcohols,
Of ketones, esters, ethers, and cellosolves (monoalkyl ethers of ethylene glycol), 1
It is possible to use one kind or a mixture of two or more kinds. As the metal oxide, mainly, silicon oxide, iron oxide (III), titanium oxide (IV), cerium (IV) oxide, tin oxide (IV), tungsten oxide (VI), tantalum oxide (V),
Antimony (III) oxide, zirconium oxide, aluminum oxide and the like can be used. In addition to the single use, two or more kinds may be used in combination, or may be used as composite fine particles.

The above hydrolyzate of metal oxide 100
The compounding amount with respect to parts is 0.2 to 5 parts. The particle size is 1 to 100 nm.

As the above-mentioned coating method, brush coating /
Immersion coating, roller coating, spray coating, spin coating, etc. can be mentioned. The conditions for dry curing are, for example, 80 to 120 ° C. × 2 hours.

(3) The antireflection film is formed by a dry plating method such as vacuum deposition, sputtering or ion plating of inorganic powder such as metal, metal oxide or metal fluoride.

The above oxides include silicon dioxide, titanium oxide (IV), tantalum oxide (V), antimony oxide (III).
, Zirconium oxide, aluminum oxide and the like, and metal fluorides include magnesium fluoride and the like.

B. A primer layer made of a polyurethane-based primer coating is interposed between the organic glass substrate of the present invention and the hard coat.

(1) The above-mentioned primer coating contains each component of (a) urethane elastomer, (b) inorganic fine particles, and (c) hydrolyzate of organoalkoxysilane as essential active ingredients. Then, a catalyst is usually added and used, and if necessary, a leveling agent, an ultraviolet absorber and an antioxidant are added.

(A) The urethane elastomer may be added in the form of a solution type, but is preferably added in the form of an aqueous emulsion.

Such a urethane elastomer is usually a thermoplastic elastomer composed of a soft phase (soft segment) composed of a long chain polyol and polyisocyanate, and a hard phase (hard segment) composed of a short chain polyol and polyisocyanate. Is desirable. Moreover,
It is desirable that a reactive component such as polyamine is added to these so that they can be partially crosslinked after coating.

The long-chain polyol forming the soft phase is polyalkylene glycol (PTMG).
Etc.), a polyester type such as a polyalkylene adipate, a polycaprolactone, a polycarbonate or the like, or a polyether polyester type in which both are mixed. Of these, polyester / polyether polyester is preferable from the viewpoint of impact resistance.

Examples of the above short-chain polyols include ethylene glycol, 1.2-propylene glycol, 1.3-butanediol, 1.4-butanediol, 1.6 hexanediol, neopentyl glycol and diethylene glycol. You can

Examples of the above polyisocyanates include aromatic diisocyanates such as tolylene diisocyanate, 4,5'-diphenylmethane diisocyanate (MDI) and 1,5-naphthalene diisocyanate, 1,6-hexamethylene diisocyanate, isophorone diisocyanate and hydrogenated M.
Examples thereof include aliphatic and alicyclic compounds such as DI. From the viewpoint of weather resistance, a non-yellowing type aliphatic / alicyclic system is preferable.

(B) It is presumed that the above-mentioned inorganic fine particles have the functions of adjusting the refractive index and improving the weather resistance. The particle size of the inorganic part particles is usually 1 to 100 nm, preferably 10 to 50 nm.
nm. If it is less than 10 nm, it is difficult to expect improvement in the refractive index of the coating film, and if it exceeds 50 nm, the coating film tends to diffusely reflect,
Cloudy phenomenon is likely to occur.

The blending amount of the inorganic fine particles varies depending on the kinds of salts and oxides and the required refractive index, but is usually 10 to 100 parts per 100 parts of polyurethane.
If it is less than 10 parts, it is difficult to achieve the effect of adding the metal compound (increasing the refractive index). If it exceeds 100 parts, the coating film tends to become cloudy.

The above-mentioned inorganic fine particles can be appropriately selected and used as a single or composite fine particles from the metal oxides exemplified in the above description of the silane-based cured coating film. In addition, nitrides such as boron nitride, aluminum nitride, and silicon nitride, and boride, sulfide, fluoride, metal salt, and the like can be appropriately selected and used. It is usually desirable to mix in the form of an aqueous sol.

(C) The above-mentioned organoalkoxysilane is presumed to have a function of ensuring adhesion with the hard coat. The blending amount of the component with respect to 100 parts of polyurethane is usually 1 to 10 parts, preferably 3 to 7 parts.
If it is less than 1 part, the effect of addition of this component (securing the adhesiveness with the hard coat) is difficult to be exhibited, and if it exceeds 10 parts, the effect of improving impact resistance may be impaired. As the organoalkoxysilane, those exemplified in the above description of the silane-based cured coating film can be used.

(D) As the catalyst, various amines, organic tin compounds, organic zinc compounds, etc. can be used.

(E) In the above, when the solution type is used, examples of the solvent include hydrocarbons, halides, alcohols, ketones, esters, ethers and the like.

(F) In the case of an aqueous emulsion, the method for preparing the primer coating material is as follows.

After mixing the urethane elastomer and the inorganic fine particles and stirring, a hydrolyzate of organoalkoxysilane is added. The organoalkoxysilane is hydrolyzed by adding water so that the molar ratio becomes equimolar and then refluxing for 2 hours or more.

(2) The thickness of this primer layer is 0.01
˜50 μm. If it is 0.01 μm or less, the effect of impact resistance cannot be expected so much, and if it is 50 μm or more, surface accuracy (leveling property) is deteriorated. The refractive index of the primer layer depends on the kind and amount of the inorganic fine particles, but is 1.40 to 1.
70.

The coating method is selected from known methods such as a dipping method and a spin coating method. The curing condition is in the range of 80 ° C to 120 ° C for 1 minute to 60 minutes.

[0043]

In the optical element (plastic lens) of the present invention, the primer layer having the above-described structure is interposed between the hard coat and the organic glass, so that the optical layer has a resistance equal to or higher than the conventional one. Not only can the impact resistance be imparted to the optical element having the antireflection film formed on the hard coat, but the refractive index of the primer layer can be freely adjusted within the range of 1.40 to 1.70. Can also be applied. Further, weather resistance is also improved as compared with conventional primer layers made of urethane resin.

[0044]

EXAMPLES In order to confirm the effects of the present invention, examples carried out together with comparative examples will be described below.

A. Preparation of primer coating <Example 1> Commercially available aqueous emulsion polyurethane "Superflex 150" (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.,
Solid content concentration 30%, non-yellowing type, ether / ester type)
100 parts, pure water 200 parts, 60 parts of an aqueous sol of Fe ₂ O ₃ / TiO ₂ composite (Fe ₂ O ₃ / TiO ₂ = 2/97, average particle diameter 30 nm, solid content concentration 10%), γ- A mixture of 8 parts of glycidoxypropyltrimethoxysilane hydrolyzed with 5 parts of pure water is mixed.

Example 2 Fe ₂ O ₃ / Ti in Example 1
An CeO ₂ / TiO ₂ composite aqueous sol (CeO ₂ / TiO ₂ = 20/80, average particle size 30 nm, solid content concentration 10%) is used instead of the O ₂ composite aqueous sol.

<Example 3> In Example 1, Fe ₂ O ₃ / T was used.
An aqueous sol of SnO ₂ (average particle size 30 nm, solid content concentration 10%) is used instead of the aqueous sol of iO ₂ complex.

Comparative Example 1 Fe ₂ O ₃ / Ti in Example 1
No aqueous sol of O ₂ complex is added.

Comparative Example 2 The hydrolysis product of γ-glycidoxypropyltrimethoxysilane in Example 1 was not added.

<Example 4> Commercially available aqueous emulsion polyurethane "Superflex 300" (manufactured by Daiichi Kogyo Seiyaku Co., Ltd., solid content concentration 30%, non-yellowing type, ether.
Ester) 100 parts, pure water 300 parts, WO ₃ aqueous sol (average particle size 20 nm, solid content concentration 10%) 60 parts,
A mixture of 10 parts of methyltrimethoxysilane hydrolyzed with 8 parts of pure water is mixed.

<Example 5> Commercially available aqueous emulsion polyurethane "Superflex 150" (manufactured by Daiichi Kogyo Seiyaku Co., Ltd., solid content concentration 30%, non-yellowing type, ether.
Ester-based) 100 parts, pure water 110 parts, Sb ₂ O ₃ aqueous sol (average particle size 20 nm, solid content concentration 10%) 150
Γ-glycidoxypropyltrimethoxysilane 8
And 5 parts of deionized water are mixed.

Example 6 100 parts of a commercially available aqueous emulsion polyurethane "Superflex 100", 60 parts of pure water, 200 parts of an aqueous sol of CeO ₂ (average particle size 20 nm, solid content concentration 10%) were mixed with γ-gly. 8 parts of cidoxypropyltrimethoxysilane hydrolyzed with 5 parts of pure water are mixed.

Example 7 In Example 6, SnO ₂ aqueous sol (average particle size 20 nm, solid content concentration 10%) is used instead of CeO ₂ aqueous sol. .

<Example 8> 100 parts of commercially available aqueous emulsion polyurethane "Superflex 100", Ce
Aqueous sol of O ₂ / TiO ₂ composite (CeO ₂ / TiO ₂
= 20/80, average particle size 30 nm, solid content concentration 10%)
To 260 parts, 10 parts of methyltrimethoxysilane and 8 parts of pure water
Mix what is hydrolyzed in parts.

<Example 9> CeO ₂ / TiO in Example 8
An aqueous sol of Sb ₂ O ₃ (average particle size 20 nm, solid content concentration 10%) is used instead of the aqueous sol of ₂ composites.

B. Preparation of hard coat liquid <Hard coat liquid a> 100 parts of γ-glycidoxypropyltrimethoxysilane, 200 parts of MeoH, 10 ^-2 NH
After hydrolyzing 100 parts of Cl at reflux for 2 hours, 1200 parts of methanol silica sol, 7 parts of acetylacetone aluminum, and 0.4 part of "Fc430" (a fluorine-based interfacial lubricant manufactured by Sumitomo 3M, the same applies hereinafter) are added.

<Hard coat liquid b> γ-glycidoxyp
100 parts of ropyltrimethoxysilane, 15 parts of ethyl silicate
Parts, methanol 20 parts, 10^-2Mix 25 parts of N HCl
And hydrolyzed at room temperature for 24 hours, Fe₂ O₃ / TiO
₂ Alcoholic sol of complex (Fe₂ O₃ / TiO ₂ =
2/98, average particle size 30 nm, solid content concentration 30%) 10
0 part, acetylacetone aluminum 20 parts, "FC-
430 "4 parts were mixed.

<Hard Coat Liquid c> In the hard coat liquid b, SnO ₂ alcohol sol (average particle size 30) was used instead of the alcohol sol of Fe ₂ O ₃ / TiO ₂ composite.
nm, solid content concentration 30%).

<Hard coating solution d> 100 parts of γ-glycidoxypropyltrimethoxysilane, 15 parts of ethyl silicate
Parts, 20 parts of methanol and 25 parts of 10 ^-2 NHcl are mixed and hydrolyzed at room temperature for 24 hours, and WO ₃ alcoholic sol (average particle size 30 nm, solid content concentration 30%) 150
Part, 20 parts acetylacetone aluminum, "FC-4
30 "4 parts were mixed.

<Hard Coat Solution e> In the hard coat solution d, Sb ₂ O ₃ alcoholic sol (average particle size 30 nm, solid content concentration 30%) is used instead of WO ₃ sol.

C. Preparation of Test Piece (1) Formation of Primer Layer The base material shown in Table 1 was coated with the primer coating material of each of the examples shown by the dipping method (pulling speed 100 mm / sec), and the conditions were 100 ° C. × 10 minutes. Cured. The specifications of the base material used are as follows. In addition, the test piece 12 did not form a primer coating film.

CR-39: Polyglycol bisallyl carbonate lens, refractive index 1.50 1.57 lens: diallyl isophthalate / allyl benzoate / benzyl methacrylate copolymer, refractive index 1.5
7 1.6 Lens: diallyl diphenate / urethane acrylate / diisopropyl peroxydicarbonate copolymer, refractive index 1.6 1.66 Lens: polythiourethane lens, refractive index 1.66 (2) Formation of hard coat On the base material on which the primer coating film has been formed, the hard coat liquid shown is applied by a dipping method (pulling speed 100 mm /
sec) and then cured at 100 ° C. × 2 hours or 110 ° C. × 2 hours.

(3) Formation of Antireflection Film On the base material on which the above hard coat is formed, a vapor deposition film is formed by vacuum vapor deposition with an inorganic substance having the following constitution.

SiO ₂ / ZrO ₂ : 1/4 λ, ZrO ₂ :
1/4 λ, SiO ₂ : 1/4 λ D. Test Items Each test item prepared as described above was subjected to the tests of the following items.

(1) Adhesion test between primer layer and silicone-based cured coating film A cellophane adhesive tape was prepared by forming 100 squares in 1 cm square at 1 mm intervals on a test piece before forming an antireflection film. After pressing strongly, the film was rapidly peeled in the 90 ° direction, and the number of squares that did not peel was counted.

(2) Scratch resistance test A 600 g load of steel wool (# 0000) was applied to the surface of the antireflection film of each test piece to rub the surface 30 times, and the degree of scratching was judged according to the following criteria. Did.

○ The scratched area is within 10%.

△ The scratched area is more than 10% and less than 30%. Χ The area with scratches exceeds 30%.

(3) Impact resistance test A steel ball (20 g) was dropped from a height of 127 cm to the center of the test piece and judged by whether or not it cracked.

(4) Appearance Place a fluorescent lamp (tri-wavelength medium white) "trade name; Lupica Ace 15W manufactured by Mitsubishi Electric Corporation" in the blackened background.
The light of a fluorescent lamp was reflected on the surface of the antireflection film of the test piece, and the presence or absence of the light interference color (rainbow pattern) formed on the surface of the object was judged.

(5) Weather resistance test Accelerated weather resistance test (Suga Shinken Co., Ltd. "Sign Shine Super Long Life Weather Ometer") 200h
After exposure, the presence or absence of the above-mentioned appearance was visually judged.

E. Test Results and Evaluation From Table 1 showing the test results, it can be seen that each example of the present invention is good in all items. On the other hand, in the case of the test piece 4 using the primer (Comparative Example 1) containing no inorganic fine particles, it can be seen that interference fringes do not appear in the appearance, but the weather resistance is poor. In addition, in the case of the test piece 5 using the primer (Comparative Example 2) containing no organoalkoxysilane, it can be seen that the adhesion between the hard coat and the substrate is poor. Further, it can be seen that the test piece 12 having no primer coating is inferior in impact resistance.

[0073]

[Table 1]

Claims (4)

[Claims] 1. An optical element in which a silicone cured coating film and an inorganic antireflection coating are laminated on the surface of an organic glass, wherein the following components are essential active ingredients between the organic glass and the silicone cured coating film. An optical element having a primer layer formed of a paint interposed. (a) Urethane elastomer (b) Inorganic fine particles (c) Hydrolyzate of organoalkoxysilane 2. The optical element according to claim 1, wherein the urethane elastomer is thermoplastic and the inorganic fine particles are metal oxides. 3. A primer coating for forming a primer layer between an organic glass and a silicone cured coating film, wherein the following components are essential active ingredients. (a) Urethane elastomer (b) Inorganic fine particles (c) Hydrolyzate of organoalkoxysilane 4. The primer coating composition according to claim 3, wherein the urethane elastomer is added in the form of an aqueous emulsion of a thermoplastic elastomer, and the inorganic fine particles are added in the form of an aqueous sol.