JP7570920B2 - Optical articles - Google Patents

Description

The present invention relates to an optical article, such as an optical lens, that has a primer layer containing silica particles and a hard coat layer on a plastic substrate.

In recent years, plastic substrates have come to replace inorganic glass substrates as the primary optical lens material. This is due to the fact that plastic substrates have superior impact resistance, workability, dyeability, etc.

Traditionally, polycarbonate resin substrates have been used primarily as plastic substrates for optical lenses due to their high transparency, but because they are easily scratched, a hard coat layer is provided on the surface to prevent scratches. In addition, because the hard coat layer does not adhere well to the plastic substrate, a primer layer is provided between the two to improve adhesion.

Such optical articles having a plastic substrate, a primer layer, and a hard coat layer are disclosed in many documents, such as Patent Documents 1 and 2.

JP 2010-150309 A International Publication No. 2007/026529

However, conventional optical articles including a plastic substrate, a primer layer, and a hard coat layer have room for further improvement in terms of hardness (hardness of the surface on the hard coat layer side).
In view of the above problems, an object of the present invention is to provide an optical article having high hardness (particularly pencil hardness) comprising a primer layer and a hard coat layer on a plastic substrate.

The present invention relates to, for example, the following [1] to [4].
[1]
An optical article comprising a plastic substrate, a primer layer provided on at least a portion of a surface of the plastic substrate, and a hard coat layer provided on a surface of the primer layer opposite to the plastic substrate,
the primer layer comprises a resin matrix and silica particles 1 having an average particle diameter of 20 to 100 nm measured by a dynamic light scattering method and determined by a cumulite analysis method;
the hard coat layer comprises a silica-based matrix and silica particles 2 having an average particle diameter of 3 to 20 nm measured by a dynamic light scattering method and determined by a cumulite analysis method;
the ratio of the average particle size of the silica particles 1 to the average particle size of the silica particles 2 is 2.5 to 20;
Optical objects.

[2]
The optical article according to [1] above, wherein the resin matrix is formed from a polyurethane having an ethylenically unsaturated bond-containing group.

[3]
The optical article according to [1] or [2], wherein the resin matrix has an elongation in the range of 150 to 200% as measured in accordance with JIS K7161.

[4]
The optical article according to any one of [1] to [3] above, wherein the plastic substrate is a polycarbonate resin substrate, a polyamide resin substrate, or a polycellulose resin substrate.

The optical article according to the present invention has high hardness. The optical article according to the present invention also has excellent appearance (transparency) and adhesion between the plastic substrate and the primer layer and hard coat layer.

The optical article according to the present invention will now be described in further detail.
The optical article of the present invention comprises a plastic substrate, a primer layer provided on a surface of the plastic substrate, and a hard coat layer provided on the surface of the primer layer opposite the plastic substrate, and there is a predetermined relationship between the particle size of the silica particles contained in the primer layer and the particle size of the silica particles contained in the hard coat layer.

The optical article according to the present invention can be produced, for example, by forming a primer layer on the surface of the plastic substrate from a primer layer-forming paint, and then forming a hard coat layer on the surface of the primer layer opposite the plastic substrate from a hard coat layer-forming paint.

First, the paint for forming the primer layer and the paint for forming the hard coat layer will be described in detail.
[Paint for forming primer layer]
The primer layer forming paint may be, for example, a primer layer forming paint composition (hereinafter also referred to as "primer paint composition") containing (A) a resin matrix forming component, (B) silica particles 1, (C) a solvent, and optionally (D) an additive (hereinafter also referred to as component (A), component (B), component (C), and component (D), respectively). As the primer layer forming paint composition, a conventionally known one may be used.

Each component will be described in detail.
(A) Resin matrix forming component
Resin matrix-forming component (A) includes, for example, polyurethanes and polyesters, with polyurethanes being preferred.

Polyurethane may be used in the form of one-component or two-component urethane paint, water-based polyurethane dispersion, etc., of which water-based polyurethane dispersion (polyurethane particles dispersed in water) is preferred.

Among the aqueous polyurethane dispersions, a self-emulsifying polyurethane emulsion is preferred. The average particle size of the emulsion particles is preferably 80 nm or less.
The water-based polyurethane dispersion is preferably anionic.

From the viewpoint of obtaining optical articles with high hardness, the polyurethane contained in the aqueous polyurethane dispersion is preferably emulsion particles of polyurethane having an ethylenically unsaturated bond-containing group.

The ethylenically unsaturated bond-containing group is preferably a (meth)acryloyl group, more preferably an acryloyl group.
As the resin matrix-forming component (A), a component conventionally known for forming a resin matrix of a primer layer, such as the polyurethane resin described in JP-A-6-337376 and the anionic emulsion fine particles of a polycarbonate-based polyurethane compound having a crosslinked structure described in JP-A-2011-99074, may be used.

The elongation of the film formed from the resin matrix-forming components, measured in accordance with JIS K7161, is preferably in the range of 150 to 200%. When the elongation is in the above range, an optical article having high hardness can be produced.
Examples of commercially available aqueous polyurethane dispersions include NeoPac R-9699 manufactured by Kusumoto Chemical Industries, Ltd. and Superflex 110 manufactured by Daiichi Kogyo Seiyaku Co., Ltd.

(B) Silica particles 1
The silica particles 1 are silica particles having an average particle size in the range of 20 to 100 nm, preferably 20 to 90 nm, as measured by dynamic light scattering and calculated by cumulant analysis.

By using silica particles 1 having an average particle size within the above range, an optical article having high hardness and high transparency can be manufactured. On the other hand, if the average particle size is below the above lower limit, the silica particles will have difficulty in withstanding impact or pressure on the optical article, and the hardness of the optical article is thought to decrease. Also, if the average particle size exceeds the above upper limit, the dispersibility of the silica particles will decrease when the primer layer forming coating composition is applied to a plastic substrate, and the hardness of the optical article is thought to decrease.

The silica particles 1 may be particles made of only silica (but may contain unavoidable impurities), or may be particles made of an oxide of silicon and at least one metal element M selected from the group consisting of Ti, Fe, Zn, W, Sn, Ta, Zr, Sb, Nb, In, Ce, Al, Y, Pb, and Mo. The amount of this metal element M is preferably small enough not to impair the effects of the present invention, and is, for example, 1.5% by mass or less, preferably 1.4% by mass or less in silica particles 1, calculated as the oxide of metal element M.

Specific examples of commercially available spherical silica particles 1 include Cataloid (registered trademark) SI-50, SI-45P, and SI-80P (all manufactured by JGC Catalysts and Chemicals Co., Ltd., in the form of silica sol).

Examples of the non-spherical (for example, irregular, linked, chain-like) silica particles 1 include those produced by a conventionally known method described in JP-A-2005-186435 and the like.
The silica particles 1 are preferably silica particles that have not been surface-treated.

(C) Solvent The solvent (C) is water and/or an organic solvent, and preferably contains water.
The organic solvent may be
Alcohols such as methanol, ethanol, 1-propanol, 2-propanol, butanol, diacetone alcohol, furfuryl alcohol, tetrahydrofurfuryl alcohol, ethylene glycol, hexylene glycol, and isopropyl glycol;
Esters such as methyl acetate, ethyl acetate, and butyl acetate;
Ethers such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, ethylene glycol isopropyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, propylene glycol monomethyl ether, and propylene glycol monoethyl ether:
Ketones such as acetone, methyl ethyl ketone, and methyl isobutyl ketone can be used.
These may be used alone or in combination of two or more.

The primer layer-forming coating composition may contain an additive (D) (hereinafter also referred to as "component (D)") that may be normally contained in a primer layer-forming coating. Examples of the additive (D) include surfactants, and other examples include ultraviolet absorbers, light stabilizers, antioxidants, crosslinking agents, and colorants (dyes, pigments, etc.).

Proportion of Each Component The proportion of each component in the coating composition for forming a primer layer is appropriately adjusted so that the proportion of the silica particles 1 in the primer layer falls within the range described below.

[Paint for forming hard coat layer]
The coating material for forming a hard coat layer may be, for example, a coating composition for forming a hard coat layer (hereinafter also referred to as a "hard coat coating composition") containing (E) a silica-based matrix forming component, (F) silica particles 2, (G) a solvent, and optionally (H) an additive (hereinafter also referred to as component (E), component (F), component (G), and component (H), respectively).

Each component will be described in detail.
(E) Silica-Based Matrix-Forming Component
Examples of the silica-based matrix forming component (E) include organosilicon compounds contained in paints for forming a hard coat layer that are conventionally known as components for forming the silica-based matrix of the hard coat layer, such as the organosilicon compounds described in paragraphs [0022] to [0030] of JP2009-197078A.

More specifically, the organosilicon compound may be at least one component selected from the group consisting of organosilicon compounds represented by the following general formula (I) (hereinafter also referred to as "organosilicon compound (e)"), their hydrolysates, and partial condensates of the hydrolysates.

R ¹ R ² _a Si(OR ³ ) _3-a ...(I)
In formula (I), R ¹ represents an organic group having a vinyl group, an epoxy group, or a methacryloxy group, and preferably an organic group having an epoxy group. The number of carbon atoms in the organic group is preferably 8 or less, and more preferably Preferably, it is 6 or less.

^R2 represents a hydrocarbon group having 1 to 4 carbon atoms.
R ³ represents a hydrocarbon group having 1 to 8 carbon atoms, an alkoxyalkyl group having up to 8 carbon atoms, or an acyl group having up to 8 carbon atoms.

a represents 0 or 1.
The organic silicon compound (e) is typically an alkoxysilane compound, and specific examples thereof include vinyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, α-glycidoxymethyltrimethoxysilane, α-glycidoxyethyltrimethoxysilane, β-glycidoxyethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, β-(3,4-epoxycyclohexyl)-ethyltrimethoxysilane, β-(3,4-epoxycyclohexyl)-ethyltriethoxysilane, and the like. Among these, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, β-(3,4-epoxycyclohexyl)-ethyltrimethoxysilane, and the like are preferred. These compounds may be used alone or in combination of two or more.

The hydrolysate of the organosilicon compound (e) and the partial condensate of the hydrolysate are respectively those obtained by partially hydrolyzing or hydrolyzing the organosilicon compound (e) in the absence of a solvent or in a polar organic solvent such as an alcohol (e.g., methanol) in the presence of an acid and water (e.g., hydrochloric acid), and those obtained by further partially condensing the hydrolysate. A part or all of these organic solvents and water may be used as they are as the solvent (G) described below when preparing the coating composition for forming the hard coat layer.

When the silica particles 2 (F) are blended as a silica sol (described later) in preparing the coating composition for forming the hard coat layer, the hydrolysis and/or partial condensation may be carried out in a state where the organosilicon compound (e) is mixed with the sol of the silica particles 2 (F) or may be carried out before mixing.

(F) Silica particles 2
The silica particles 2 are silica particles having an average particle size in the range of 3 to 20 nm, preferably 4 to 15 nm, as measured by dynamic light scattering and calculated by cumulant analysis.

The silica particles 2 may be particles made of only silica (but may contain unavoidable impurities), or may be particles made of an oxide of silicon and at least one metal element M selected from the group consisting of Ti, Fe, Zn, W, Sn, Ta, Zr, Sb, Nb, In, Ce, Al, Y, Pb, and Mo. The amount of this metal element M is preferably small enough not to impair the effects of the present invention, and is, for example, 1.5% by mass or less, preferably 1.4% by mass or less in the silica particles 2, calculated as the oxide of the metal element M.

The silica particles 2 can be produced by a conventional method described in, for example, JP 2009-197078 A. Specific examples of commercially available products of the silica particles 2 include Cataloid SI-550, SI-30, and SI-40 (all manufactured by JGC Catalysts and Chemicals, in the form of silica sol).
The silica particles 2 are preferably silica particles whose surfaces have been treated with a silane coupling agent or the like.

(G) Solvent Specific examples of the solvent (G) include the solvents exemplified as specific examples of the solvent (C).

The coating composition for forming a hard coat layer may contain an additive (H) (hereinafter also referred to as "component (H)") that can be usually contained in a coating composition for forming a hard coat layer. Examples of the additive ( H) include a curing agent, a surfactant, an ultraviolet absorber, a light stabilizer, an antioxidant, and a colorant (dye, pigment, etc.).

Examples of the curing agent include curing agents that can be contained in conventionally known coating materials for forming hard coat layers, such as the curing agents described in [0033] to [0036] of JP2009-197078A.

Proportion of Each Component The proportion of each component in the coating composition for forming a hard coat layer is appropriately adjusted so that the proportion of the silica particles 2 in the hard coat layer falls within the range described below.

[Optical article]
The optical article according to the present invention (for example, an optical lens such as a spectacle lens, or an optical film) comprises a plastic substrate, a primer layer, and a hard coat layer.

The primer layer is provided on at least a portion of the surface of the plastic substrate. For example, the primer layer may be provided on one surface of the plate- or film-shaped plastic substrate, or on both surfaces of the plastic substrate.

The hard coat layer is provided on the surface of the primer layer opposite to the plastic substrate.
The optical article according to the present invention may further include an optional layer such as an anti-reflection film, an antistatic film, an antifouling film, etc. on the surface of the hard coat layer opposite to the primer layer, depending on the purpose of use. The optional layer may be one layer or multiple layers.

Plastic Substrates:
The refractive index of the plastic substrate is preferably 1.45 to 1.65.
Examples of the plastic substrate include polycarbonate resins, polyamide resins, and polycellulose resins (such as triacetyl cellulose).

Primer layer and hard coat layer:
The primer layer contains a resin matrix and the silica particles 1. The silica particles 1 are dispersed in the resin matrix.

The proportion of the silica particles 1 in the primer layer is preferably 10 to 70% by mass, and more preferably 15 to 60% by mass.
The thickness of the primer layer is preferably in the range of 0.5 to 5.0 μm, more preferably 0.5 to 4.0 μm.

The primer layer can be formed, for example, by applying the primer layer-forming paint to the surface of the plastic substrate and curing it. The resin matrix is formed from the resin matrix-forming components by curing.

The resin matrix is preferably formed from a polyurethane having an ethylenically unsaturated bond-containing group. The ethylenically unsaturated bond-containing group is preferably a (meth)acryloyl group, more preferably an acryloyl group.

The hard coat layer contains a silica-based matrix and the silica particles 2. The silica particles 2 are dispersed in the silica-based matrix.
The content of the silica particles 2 in the hard coat layer is preferably 10 to 70% by mass, and more preferably 15 to 60% by mass.
The thickness of the hard coat layer is preferably in the range of 3.0 to 10.0 μm, and more preferably in the range of 3.0 to 8.0 μm.

The hard coat layer can be formed, for example, by applying the coating material for forming the hard coat layer to the surface of the primer layer and curing the coating material. The silica-based matrix is formed from the silica-based matrix-forming components by curing.

When curing each coating, for example, the coating material for forming the primer layer may be applied to the surface of the plastic substrate and pre-cured by heating at 60 to 120°C for 3 to 30 minutes, and the coating material for forming the hard coat layer may be applied to the surface of the pre-cured coating film and pre-cured by heating at 80 to 130°C for 0.5 to 5 hours.

Silica particle size:
As described above, the silica particles 1 contained in the primer layer are preferably silica particles having a large area for receiving impacts and pressures from above (toward the hard coat layer), and taking into consideration the transparency of the primer layer, the average particle size of the silica particles 1 is 20 to 100 nm, preferably 20 to 90 nm.

As described above, the silica particles 2 contained in the hard coat layer are preferably silica particles with a large surface area, easy to densify, and small particle size, so the average particle size of the silica particles 2 is 3 to 20 nm, and preferably 4 to 15 nm.

In the optical article according to the present invention, the relationship between the average particle size of the silica particles 1 contained in the primer layer and the average particle size of the silica particles 2 contained in the hard coat layer is important, and the value of the average particle size of the silica particles 1/the average particle size of the silica particles 2 (hereinafter also referred to as the "particle size ratio") is 2.5 to 20, and preferably 2.5 to 18. When the particle size ratio is within this range, for the above-mentioned reasons, the optical article according to the present invention has high hardness on the surface of the hard coat layer.

The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples.

[Measurement method and evaluation test method]
The measurement methods and evaluation test methods employed in the examples and other sections are as follows.
(1) Average particle size of silica particles:
A sample with a solid content of 0.15% prepared by mixing a water-dispersed sol of silica particles with pure water was placed in a quartz cell with a length of 1 cm, a width of 1 cm, and a height of 5 cm, and the particle size distribution of the particle group was measured using an ultrafine particle size analyzer (manufactured by Otsuka Electronics Co., Ltd., model ELS-Z2) using a dynamic light scattering method. From the measurement results, the average particle size was calculated by the cumulant method.

(2) Adhesion between primer layer and hard coat layer:
On the hard coat layer side surface of a plastic lens substrate with a primer layer and a hard coat layer produced in an Example or Comparative Example, 100 1 mm square grids were formed by cutting with a knife at 1 mm intervals down to the substrate, and a cellophane adhesive tape with the product name "NICHIBAN" was pressed against the grids and then pulled in a direction at 90 degrees to the in-plane direction of the lens substrate. This operation was repeated a total of 10 times, and the number of grids that did not peel off was counted.

(3) Appearance of coating film (cloudy):
The haze of the plastic lens substrate with the primer layer and hard coat layer prepared in the Examples or Comparative Examples was measured using a color and turbidity simultaneous measuring instrument COH 400 (manufactured by Nippon Denshoku Industries Co., Ltd.).

(4) Pencil hardness of optical article:
The hardness of the surface of the hard coat layer of each of the plastic lens substrates with a primer layer and a hard coat layer prepared in the Examples or Comparative Examples was measured using a pencil hardness tester in accordance with JIS K5600.

[Production of optical articles]
(Preparation of primer coating composition)
[Production Example P1]
While stirring 124.5 g of urethane acrylic copolymer dispersion (Kusumoto Chemical Co., Ltd., NeoPac R-9699, elongation: 160%, average particle size: 77 nm, solid content concentration: 40 mass%), 252.1 g of pure water (Takasugi Pharmaceutical Co., Ltd.), 496.4 g of methanol (Hayashi Pure Chemical Industries Co., Ltd.), 123.0 g of silica particles (JGC Catalysts and Chemicals Co., Ltd., Cataloid SI-45P, average particle size: 45 nm, solid content concentration: 40.5 mass%), and 4.0 g of leveling agent (10% methanol dilution of L-7604 (Toray Dow Corning Co., Ltd.)) were added, and the mixture was stirred at room temperature for one day and night to prepare a primer coating composition (P1).
The amounts of each component in the primer coating composition (P1) (expressed as relative amounts with the total amount of each component taken as 100 parts by mass) are shown in Table 1.

[Production examples P2 to P3, C1 to C4]
Primer coating compositions (P2), (P3), (C1) to (C4) were prepared in the same manner as in Production Example P1, except that the types and amounts of each component were changed as shown in Table 1. The amounts of each component in these coating compositions are shown in Table 1.

(Preparation of hard coat coating composition)
[Production Example H1]
131.9 g of γ-glycidoxypropyltrimethoxysilane (A-187, manufactured by Momentive Performance Materials Japan, LLC, solid content concentration: 98.5% by mass or more) was mixed with 17.3 g of methanol (manufactured by Hayashi Pure Chemical Industries, Ltd.), and 38.9 g of a 0.01 N aqueous hydrochloric acid solution was added dropwise to this solution while stirring. Furthermore, this solution was stirred overnight at room temperature to hydrolyze the silane compound.

Next, to this hydrolyzed liquid, 3.08 g of methanol, 643.5 g of silica particles (Cataloid SI-550 manufactured by JGC Catalysts and Chemicals Co., Ltd., average particle size: 5 nm, solid content concentration: 20.5 mass%, dispersion medium: water), 134.5 g of propylene glycol monomethyl ether (manufactured by Dow Chemical Japan Co., Ltd.), 11.3 g of 1,2,3,4-butanetetracarboxylic acid (manufactured by Kanto Chemical Co., Ltd., purity: 98 mass% or more), 8.1 g of dicyandiamide (manufactured by Kishida Chemical Co., Ltd., purity: 98 mass% or more), 7.6 g of a leveling agent (DOWSIL ^™ L-7001 Fluid (manufactured by Dow Toray Co., Ltd.) diluted with 10% methanol), and a leveling agent (DOWSIL ^™ SH 28 Paint To the mixture was added 3.8 g of Additive (a 10% dilution of propylene glycol monomethyl ether available from Dow Toray Industries, Inc.), and the mixture was stirred overnight at room temperature to prepare a coating composition (H1).
The amounts of each component in the hard coat coating composition (H1) (expressed as relative amounts assuming the total amount of each component to be 100 parts by mass) and the evaluation results are shown in Table 1.

[Production Examples H2, H3, C5]
Hard coat coating compositions (H2), (H3), and (C5) were prepared in the same manner as in Preparation Example H1, except that the types and amounts of each component were changed as shown in Table 2. The amounts of each component in the coating composition are shown in Table 2.

(Manufacture of optical articles)
[Example 1]
(Formation of primer layer)
Etching was performed by immersing a plastic lens (made of polycarbonate resin) for 3 minutes in a 5% aqueous NaOH solution heated to 40° C., after which sodium hydroxide adhering to the lens was thoroughly washed away with water and dried with hot air at 50° C. The primer coating composition (P1) produced in Production Example P1 was applied by dipping to the surface of the plastic lens (made of polycarbonate resin) substrate thus pretreated to form a coating film.

Next, the coating film was heat-treated at 80°C for 10 minutes to harden the coating film (primer layer). The thickness of the primer layer thus formed after hardening was 0.9 μm.

(Formation of hard coat layer)
The hard coat coating composition (H1) was applied by dipping onto the surface of the primer layer formed on the plastic lens substrate to form a coating film.

Next, the coating film was dried at 100°C for 10 minutes, and then heat-treated at 120°C for 1 hour to harden the coating film (hard coat layer), thereby obtaining a lens substrate with a coating film (hereinafter also referred to as an "optical article"). The hard coat layer thus formed had a thickness of 5.2 μm after hardening.

[Examples 2 to 6, Comparative Examples 1 to 5]
Optical articles were produced in the same manner as in Example 1, except that the primer coating composition and hard coat coating composition shown in Table 3 were used. In Example 4, the thickness of the primer layer was adjusted by increasing the lifting speed in the dipping method. The evaluation results of the optical articles are shown in Table 3.

Claims (4)

An optical article comprising a plastic substrate, a primer layer provided on at least a portion of a surface of the plastic substrate, and a hard coat layer provided on a surface of the primer layer opposite to the plastic substrate,
the primer layer comprises a resin matrix and silica particles 1 having an average particle diameter of 20 to 100 nm measured by a dynamic light scattering method and determined by a cumulite analysis method;
The silica particles 1 are particles consisting of silica only (however, unavoidable impurities may be contained), or particles consisting of an oxide of silicon and at least one metal element M selected from the group consisting of Ti, Fe, Zn, W, Sn, Ta, Zr, Sb, Nb, In, Ce, Al, Y, Pb and Mo, in which the amount of the metal element M is 1.5 mass% or less in terms of the oxide of the metal element M,
the hard coat layer comprises a silica-based matrix and silica particles 2 having an average particle diameter of 3 to 20 nm measured by a dynamic light scattering method and determined by a cumulite analysis method;
the ratio of the average particle size of the silica particles 1 to the average particle size of the silica particles 2 is 2.5 to 20;
Optical objects. The optical article according to claim 1, wherein the resin matrix is formed from a polyurethane having an ethylenically unsaturated bond-containing group. The optical article according to claim 1 or 2, wherein the resin matrix has an elongation in the range of 150 to 200% as measured in accordance with JIS K7161. The optical article according to any one of claims 1 to 3, wherein the plastic substrate is a polycarbonate resin substrate, a polyamide resin substrate, or a polycellulose resin substrate.