Composition for forming primer layer

Abstract

To provide a composition capable of forming a primer layer having high transparency and a high refractive index.SOLUTION: There is provided a composition for forming a primer layer which comprises a zirconium element-containing metal oxide (A) and an aqueous urethane resin (B), wherein the zirconium element-containing metal oxide (A) has an average particle diameter of 1 to 20 nm as measured by a dynamic light scattering method, the pH of a 30 mass% aqueous dispersion of the zirconium element-containing metal oxide (A) is 8 to 11 and the elemental silicon content is 20 mol% or less with respect to 100 mol% of the elemental zirconium in (A).SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a composition for forming a primer layer. More specifically, it relates to a composition for forming a primer layer useful for lens applications such as glasses.

Background Art

[0002] In recent years, plastic lenses that are excellent in light weight, impact resistance, processability, etc. have become the mainstream for spectacle lenses. Plastic lenses have the drawback of being easily scratched, and a hard coat layer is formed on the surface of the lens substrate. If the adhesion between the lens substrate and the hard coat layer is poor, it will cause cracks and a decrease in impact resistance. Therefore, by providing a primer layer between the lens substrate and the hard coat layer, the adhesion and impact resistance are improved. However, if the refractive index of the primer layer does not match the refractive index of the lens substrate, interference fringes will occur due to light interference, damaging the appearance. Therefore, a technique for adjusting the refractive index of the primer layer to match the refractive index of the lens substrate has been proposed. For example, in Patent Document 1, inorganic composite oxide fine particles are used as a coating liquid for a primer layer, surface-modified with an organosilicon compound A represented by a predetermined formula or its partial hydrolyzate, and an organosilicon compound B represented by a predetermined formula and having a boiling point of 120°C or lower at 1 atm or its partial hydrolyzate, and a coating liquid containing surface-modified inorganic composite oxide fine particles having a carbon atom content of 2 to 10% by weight has been proposed.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] As described above, although technologies for forming a primer layer on a lens have been developed, due to the increasing need for thinning and lightening of lenses, the refractive index of plastic lens substrates has been increasing. When the surface of inorganic composite oxide fine particles is coated with other elements such as silicon as in Patent Document 1, the refractive index of the inorganic composite oxide fine particles decreases, making it difficult to cope with plastic lens substrates having a high refractive index. There has been a demand for a composition for forming a primer layer having a high refractive index and high transparency.

[0005] The present invention has been made in view of the above situation, and an object thereof is to provide a composition capable of forming a primer layer having high transparency and a high refractive index.

Means for Solving the Problems

[0006] The present inventor has conducted various studies on a composition for forming a primer layer such as a lens. As a result, in a composition containing a zirconium element-containing metal oxide and an aqueous urethane resin, the content of silicon element is 20 mol% or less with respect to 100 mol% of zirconium element in (A), the average particle diameter is in a predetermined range, and the pH of a 30 mass% aqueous dispersion is 8 to 11. By using a zirconium element-containing metal oxide, it has been found that a primer layer having high transparency and a high refractive index can be formed on a lens, and the present inventor has conceived that the above problems can be solved excellently and has reached the present invention.

[0007] The present invention includes the following composition for forming a primer layer and the like. 〔1〕A composition for forming a primer layer containing a zirconium element-containing metal oxide (A) and an aqueous urethane resin (B), wherein the zirconium element-containing metal oxide (A) has an average particle diameter measured by the dynamic light scattering method of 1 to 20 nm, the pH of a 30 mass% aqueous dispersion of the zirconium element-containing metal oxide (A) is 8 to 11, and the content of silicon element is 20 mol% or less with respect to 100 mol% of zirconium element in (A). 〔2〕The primer layer-forming composition according to the above 〔1〕, wherein the content ratio of the zirconium element-containing metal oxide (A) is 40 to 80% by mass based on 100% by mass of the solid content in the primer layer-forming composition. 〔3〕The primer layer-forming composition according to the above 〔1〕 or 〔2〕, wherein the content ratio of the solid content in the aqueous urethane resin (B) is 20 to 60% by mass based on 100% by mass of the solid content in the primer layer-forming composition. 〔4〕The primer layer-forming composition according to any one of the above 〔1〕 to 〔3〕, which is used for lens applications. 〔5〕A lens coated with the primer layer-forming composition according to any one of the above 〔1〕 to 〔3〕. 〔6〕A method for producing a primer layer-forming composition, the production method including a step of mixing a zirconium element-containing metal oxide (A) and an aqueous urethane resin (B), wherein the zirconium element-containing metal oxide (A) has an average particle diameter measured by the dynamic light scattering method of 1 to 20 nm and a pH of 8 to 11 when made into a 30% by mass aqueous dispersion, a method for producing a primer layer-forming composition.

Advantages of the Invention

[0008] The primer layer-forming composition of the present invention has the above-described configuration, has high transparency, and can form a primer layer having a high refractive index, and thus can be suitably used for primer layers such as lenses.

Modes for Carrying Out the Invention

[0009] Preferred embodiments of the present invention will be specifically described below. However, the present invention is not limited to the following description and can be appropriately modified and applied without changing the gist of the present invention. In addition, a form in which two or more of the individual preferred embodiments of the present invention described below are combined also falls within the scope of the preferred embodiments of the present invention.

[0010] 〔Primer Layer-Forming Composition〕 The composition for forming a primer layer of the present invention is a composition for forming a primer layer containing a zirconium element-containing metal oxide (A) and an aqueous urethane resin (B). The zirconium element-containing metal oxide (A) has an average particle diameter measured by the dynamic light scattering method of 1 to 20 nm, the pH of a 30% by mass aqueous dispersion of the zirconium element-containing metal oxide (A) is 8 to 11, and the content of silicon element is 20 mol% or less with respect to 100 mol% of the zirconium element in (A). In the composition for forming a primer layer of the present invention, the pH of a 30% by mass aqueous dispersion of the zirconium element-containing metal oxide (A), which is a raw material before being added to the composition, is within the above range, and the average particle diameter of the zirconium element-containing metal oxide (A) is within the above range, whereby the composition has excellent transparency, and the content of silicon element is within the above range, whereby the composition has a high refractive index. Due to the above configuration, the primer layer formed on a lens or the like from the composition for forming a primer layer of the present invention is also excellent in solvent resistance, adhesion, weather resistance, and impact resistance.

[0011] In the composition for forming a primer layer of the present invention, the content of silicon element is 20 mol% or less with respect to 100 mol% of the zirconium element in the zirconium element-containing metal oxide (A). Thereby, the refractive index can be sufficiently increased. The content of silicon element is preferably 10 mol% or less, more preferably 5 mol% or less, still more preferably 1 mol% or less, particularly preferably 0.1 mol% or less, and most preferably 0 mol%.

[0012] In the above composition for forming a primer layer, the content ratio of the zirconium element-containing metal oxide (A) is preferably 40 to 80% by mass with respect to 100% by mass of the solid content (non-volatile content) in the composition for forming a primer layer. More preferably 43 to 75% by mass, still more preferably 44 to 73% by mass, and particularly preferably 45 to 70% by mass.

[0013] In the composition for forming the primer layer, the content ratio of the solid content in the aqueous urethane resin (B) is preferably 20 to 60% by mass with respect to 100% by mass of the solid content in the composition for forming the primer layer. More preferably, it is 25 to 57% by mass, still more preferably 27 to 56% by mass, and particularly preferably 30 to 55% by mass.

[0014] In the composition for forming the primer layer, the content ratio of the solid content in the aqueous urethane resin (B) is preferably 25 to 150% by mass with respect to 100% by mass of the zirconium element-containing metal oxide (A). More preferably, it is 30 to 145% by mass, still more preferably 35 to 140% by mass, and particularly preferably 40 to 130% by mass.

[0015] It is preferable that the composition for forming the primer layer adjusts the solid content concentration of the composition for forming the primer layer by including a solvent. The solid content concentration of the composition for forming the primer layer is not particularly limited, but is preferably 5 to 50% by mass. More preferably, it is 5 to 45% by mass, still more preferably 6 to 40% by mass, and particularly preferably 7 to 30% by mass. The ratio of the solvent in the composition for forming the primer layer is preferably the value obtained by subtracting the solid content concentration from 100% by mass of the composition.

[0016] The composition for forming the primer layer of the present invention may contain other components other than the zirconium element-containing metal oxide (A), the aqueous urethane resin (B), and the solvent. The content ratio of the other components is not particularly limited, but is preferably 0 to 30% by mass with respect to 100% by mass of the solid content in the composition for forming the primer layer. More preferably, it is 0 to 28% by mass, still more preferably 0 to 25% by mass, and particularly preferably 0 to 20% by mass.

[0017] The composition for forming the primer layer of the present invention preferably has a refractive index of 1.55 to 1.74 when the composition is made into a cured film with a thickness of 1 μm. The refractive index is preferably 1.58 to 1.70. The refractive index of the cured film can be measured by the method described in the examples.

[0018] For the composition for forming a primer layer of the present invention, when the composition is made into a cured film with a thickness of 3 μm, the total light transmittance is preferably 94.0 to 100.0%. Preferably, the total light transmittance is 95.0 to 100.0%. The total light transmittance of the cured film can be measured by the method described in the examples.

[0019] Hereinafter, the essential components and optional components contained in the composition for forming a primer layer of the present invention will be further described.

[0020] <Zirconium element-containing metal oxide (A)> The zirconium element-containing metal oxide (A) is not particularly limited as long as it contains zirconium atoms and oxygen atoms, and may contain elements other than zirconium atoms and oxygen atoms. Examples of other elements include at least one stabilizing element selected from sodium, magnesium, aluminum, potassium, titanium, hafnium, rare earth elements, etc., in addition to the above-mentioned silicon. When the zirconium element-containing metal oxide (A) contains the above stabilizing element, the thermal stability of the metal oxide (A) is further improved. Specific examples of the rare earth elements include, for example, Y, La, Ce, Pr, Nd, Sm, Eu, Tb, Dy, Ho, etc.

[0021] Regarding the content of the other elements in the zirconium element-containing metal oxide (A), there is no particular limitation as long as the content of the other elements in the composition is 20 mol% or less with respect to 100 mol% of the zirconium element. However, with respect to 100 mol% of the zirconium element, it is preferably 0 to 20 mol%. More preferably, it is 0 to 10 mol%, and still more preferably, it is 0 to 5 mol%. In one aspect, the content of the other elements may be in a proportion greater than 0 mol%.

[0022] The average particle diameter (D50) of the above zirconium element-containing metal oxide (A) measured by the dynamic light scattering method is 1 to 20 nm in the state of the dispersion liquid. When the average particle diameter is 1 nm or more, aggregation of primary particles can be sufficiently suppressed. Further, when the average particle diameter is 20 nm or less, a decrease in the transparency of the primer layer can be sufficiently suppressed. More preferably, it is 1 to 19 nm, still more preferably 1 to 18 nm, and even more preferably 2 to 17 nm. Further, the D50 / D90 of the above zirconium element-containing metal oxide is more preferably 0.2 to 1.0, and even more preferably 0.3 to 1.0. By using a zirconium element-containing metal oxide having such a small average particle diameter (D50) and a narrow particle size distribution, the resulting primer layer-forming composition has higher transparency.

[0023] In addition, the above zirconium element-containing metal oxide (A) may be surface-treated with an inorganic compound or an organic compound. Examples of the inorganic compound include silicon oxide and aluminum oxide. Examples of the organic compound include silane coupling agents, titanate coupling agents, and surfactants having acidic groups such as phosphate groups, carboxylic acid groups, and phosphonic acid groups.

[0024] The pH of the 30 mass% aqueous dispersion of the above zirconium element-containing metal oxide (A) before being added to the composition is 8 to 11. Thereby, the transparency of the obtained primer layer is improved. More preferably, the pH is 8.5 to 11, and even more preferably 9 to 11. The above pH can be measured at room temperature (25 °C) with a pH meter using a glass electrode.

[0025] The form of the above zirconium element-containing metal oxide (A) is not particularly limited, but it is preferably crystalline. The crystal structure is preferably cubic, tetragonal, monoclinic, etc., and a plurality of crystal structures may be present. By including the above crystal structure in the form of the zirconium element-containing metal oxide (A), the refractive index and hardness of the zirconium element-containing metal oxide (A) are further improved.

[0026] The method for producing the zirconium element-containing metal oxide (A) is not particularly limited. For example, a method of heating and hydrolyzing an aqueous zirconium salt solution (hydrolysis method), a method of adding an alkali to an aqueous zirconium salt solution to form zirconium hydroxide and peptizing it (neutralization coprecipitation method), a method of adding an acid and an alkali to zirconium hydroxide and then performing hydrothermal treatment (hydrothermal synthesis method), etc. can be mentioned.

[0027] As the method for producing the zirconium element-containing metal oxide (A), preferably, a neutralization coprecipitation step of adding an alkali to an aqueous solution containing a zirconium salt to form a hydroxide and peptizing it, and a hydrothermal step of adding an acid or its salt to the product obtained in the neutralization coprecipitation step and performing hydrothermal treatment are performed.

[0028] The zirconium salt used in the above neutralization coprecipitation step is not particularly limited as long as it contains a zirconium element, but chlorides, oxychlorides, sulfates, nitrates, etc. are preferred. More preferably, they are chlorides and oxychlorides. Examples of the zirconium compound used as a raw material for producing a slurry containing a zirconium element-containing compound include hydroxides, oxyhydroxides, chlorides, sulfides, sulfates, nitrates, carbonates, bicarbonates, acetates, phosphates, oxalates, butyrates, selenates, iodates, fluorides, oxychlorides, etc. Among these, oxychlorides, chlorides, sulfates, nitrates, acetates, etc., which are water-soluble zirconium compounds suitable for production, are preferred.

[0029] When the zirconium element-containing metal oxide (A) contains an element other than zirconium atoms and oxygen atoms, it is preferable to add a salt of the other element in the above neutralization coprecipitation step. Examples of the salt of the other element include chlorides, oxychlorides, sulfates, nitrates, acetates, etc.

[0030] The alkali used in the neutralization coprecipitation step is not particularly limited, and examples thereof include hydroxides of alkali metals and alkaline earth metals such as sodium hydroxide, potassium hydroxide, and calcium hydroxide; ammonia; organic amines, etc. Among them, hydroxides of alkali metals such as sodium hydroxide and potassium hydroxide are preferred.

[0031] The amount of alkali used in the neutralization coprecipitation step is not particularly limited, but it is preferably 10 to 1,000 mol% with respect to a total of 100 mol% of zirconium element and the other elements.

[0032] The acid or its salt used in the hydrothermal step is not particularly limited, and examples thereof include inorganic acids such as phosphoric acid; organic acids such as formic acid, acetic acid, propionic acid, oxalic acid, malonic acid, succinic acid, fumaric acid, maleic acid, lactic acid, malic acid, tartaric acid, citric acid, gluconic acid, etc. and salts thereof. Among these, organic acids and their salts are preferred.

[0033] The amount of acid or its salt used in the hydrothermal step is not particularly limited, but it is preferably 50 to 1,000 mol% with respect to a total of 100 mol% of zirconium element and the other elements. More preferably, it is 100 to 500 mol%.

[0034] The hydrothermal temperature in the hydrothermal step is not particularly limited, but it is preferably 170 to 230 °C. More preferably, it is 175 to 220 °C.

[0035] The hydrothermal treatment time in the hydrothermal step is not particularly limited, but it is preferably 1 to 10 hours. More preferably, it is 1.5 to 6 hours.

[0036] The method for producing the zirconium element-containing metal oxide (A) preferably includes a washing step after the neutralization coprecipitation step and / or the hydrothermal step. The cleaning method in the above cleaning step is not particularly limited and can be carried out by a commonly used method. For example, after the above neutralization coprecipitation step, a cleaning method such as filtration and water washing is preferable. Further, after the hydrothermal step, it is preferable to use an ultrafiltration membrane or the like.

[0037] When producing the zirconium element-containing metal oxide (A) by the above production method, since it is obtained as an aqueous dispersion, it may be replaced with an organic solvent when used in the primer layer-forming composition of the present invention.

[0038] The above organic solvent is not particularly limited. For example, alcohols such as methanol, ethanol, and isopropanol; ketones such as acetone; esters such as ethyl lactate; polyhydric alcohols such as ethylene glycol, ethylene glycol monomethyl ether, ethylene glycol monobutyl ether, propylene glycol monomethyl ether, and propylene glycol monomethyl ether acetate and their ethers; cyclic ethers such as dioxane and tetrahydrofuran, etc., which have good compatibility with water. These can be used alone or in combination. Further, ketones such as acetylacetone, methyl ethyl ketone, and methyl isobutyl ketone, esters such as ethyl acetate and butyl acetate, and aromatic hydrocarbons such as benzene and toluene, which have good compatibility with these organic solvents, can also be appropriately used in combination. Among these, lower alcohols having 1 to 3 carbon atoms are preferable. More preferably, it is methanol.

[0039] <aqueous urethane resin (B)> The aqueous urethane resin (B) contained in the composition for forming a primer layer of the present invention is not particularly limited as long as it is a polymer having a urethane bond containing water. For example, a self-emulsifying type aqueous urethane resin having a hydrophilic group such as an anionic group, a cationic group, or a nonionic group; a forced emulsification type aqueous urethane resin forcibly dispersed in water with an emulsifier can be used. Among them, it is preferable to use a self-emulsifying type aqueous urethane resin. The average particle diameter of the aqueous urethane resin is preferably 0.06 μm or less. In addition, a commercially available product can also be used as the aqueous urethane resin. Examples of commercially available products include the Evafanol series manufactured by Nikkawa Chemical Co., Ltd., the Superflex series manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd., the Adeka Bon Titizer series manufactured by ADEKA Corporation, and the like.

[0040] Specific examples of the aqueous urethane resin (B) include a non-yellowing isocyanate-polyester-based aqueous urethane resin, a non-yellowing isocyanate-polyether-based aqueous urethane resin, a non-yellowing isocyanate-polycarbonate-based aqueous urethane resin, a non-yellowing isocyanate-polyester / ether-based aqueous urethane resin, a non-yellowing isocyanate-polyester / polycarbonate-based aqueous urethane resin, an aromatic isocyanate-polyester-based aqueous urethane resin, an aromatic isocyanate-polyether-based aqueous urethane resin, an aromatic isocyanate-polycarbonate-based aqueous urethane resin, an aromatic isocyanate-polyester / ether-based aqueous urethane resin, an aromatic isocyanate-polyester / polycarbonate-based aqueous urethane resin, and the like. Among them, a non-yellowing aqueous urethane resin is preferable, and this makes the solvent resistance and weather resistance more excellent. More preferably, the aqueous urethane resin (B) is a non-yellowing isocyanate-polyester-based aqueous urethane resin, a non-yellowing isocyanate-polyester / ether-based aqueous urethane resin, or a non-yellowing isocyanate-polycarbonate-based aqueous urethane resin.

[0041] The solvent that can be used in the composition for forming the primer layer of the present invention is not particularly limited, and examples thereof include water and organic solvents. The type of the organic solvent is not particularly limited, and examples thereof include alcohol solvents, ketone solvents, ether solvents, ester solvents, hydrocarbon solvents, halogenated hydrocarbon solvents, amide solvents, sulfone solvents, and sulfoxide solvents. Preferably, the solvent is water and / or a water-soluble organic solvent, and a mixed solvent of water and a water-soluble organic solvent may also be used. More preferably, the solvent is water, methanol, ethanol, isopropanol, or propylene glycol monomethyl ether.

[0042] The above-mentioned water-soluble organic solvent is an organic solvent that is compatible with water, and more specifically, at 25°C, it means an organic solvent having a solubility in water of 10% by mass or more, preferably 50% by mass or more. Examples of the water-soluble organic solvent include alcohols such as methanol, ethanol, isopropanol, ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, trimethylene glycol, tripropylene glycol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 1,4-butenediol, and hexylene glycol; polyhydric alcohols and their ethers such as ethylene glycol monomethyl ether, ethylene glycol monoisopropyl ether, ethylene glycol monoethyl ether, ethylene glycol mono-n-propyl ether, ethylene glycol mono-n-butyl ether, ethylene glycol mono-t-butyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether (1-methoxy-2-propanol), propylene glycol mono-n-propyl ether, and propylene glycol monomethyl ether acetate; ketones such as acetone, diacetone alcohol, and acetylacetone; and amides such as N-methyl-2-pyrrolidone.

[0043] The composition for forming a primer layer of the present invention may contain a zirconium element-containing metal oxide (A), an aqueous urethane resin (B), and other components other than the solvent. The other components are not particularly limited, but include oxides of metals other than zirconium, dispersants, surface treatment agents, leveling agents, crosslinking agents, chelating agents, antistatic agents, defoaming agents, flame retardants, ultraviolet absorbers, anti-aging agents, coating film adjusters, light stabilizers, antioxidants, anti-coloring agents, dyes, and various other additives.

[0044] Examples of the oxides of metals other than zirconium include oxides of metals such as Ti, Al, Sn, Sb, Ta, Ce, La, Fe, Zn, and W. Preferred oxides of metals other than zirconium are titanium oxide, antimony oxide, zinc oxide, and cerium oxide, and these may be composite oxides. These are available as commercial products, and examples of commercial products include sols in which particles containing these metal oxides are dispersed in water or an organic solvent.

[0045] Examples of the dispersant include anionic surfactants such as sulfate ester type, carboxylic acid type, and phosphate ester type, cationic surfactants such as quaternary ammonium type, nonionic surfactants such as alkyl ether type, amphoteric surfactants such as alkyl betaine type, and polymer type surfactants.

[0046] Examples of the leveling agent include silicone-based leveling agents, fluorine-based leveling agents, acrylic-based leveling agents, and acrylic silicone-based leveling agents.

[0047] 〔Method for producing a composition for forming a primer layer〕 The present invention is a method for producing a composition for forming a primer layer, the production method including a step of mixing a zirconium element-containing metal oxide (A) and an aqueous urethane resin (B), wherein the zirconium element-containing metal oxide (A) has an average particle diameter measured by the dynamic light scattering method of 1 to 20 nm and a pH of 8 to 11 when it is made into a 30% by mass aqueous dispersion, and it is also a method for producing a composition for forming a primer layer.

[0048] The mixing step of the zirconium element-containing metal oxide (A) and the aqueous urethane resin (B) is not particularly limited as long as the zirconium element-containing metal oxide (A) and the aqueous urethane resin (B) are mixed, and it is preferably mixed by stirring or the like.

[0049] The zirconium element-containing metal oxide (A) used in the above mixing step has an average particle diameter measured by the dynamic light scattering method of 1 to 20 nm, and a pH of 8 to 11 when it is made into a 30% by mass aqueous dispersion. The production method of the zirconium element-containing metal oxide (A) is as described above, and it is sufficient that the pH of the zirconium element-containing metal oxide (A) before mixing with the aqueous urethane resin (B) is 8 to 11 when it is made into a 30% by mass aqueous dispersion. When mixing with the aqueous urethane resin (B), those substituted with an organic solvent such as methanol may be used.

[0050] The addition amounts of the zirconium element-containing metal oxide (A) and the aqueous urethane resin (B) used in the above mixing step are not particularly limited, and it is preferable to add them so as to obtain the above-mentioned preferable ratio in the primer layer-forming composition.

[0051] 〔Use of the primer layer-forming composition〕 The primer layer-forming composition of the present invention can be suitably used for a primer layer (primer film) or the like between a lens substrate and a hard coat layer in an optical plastic such as a lens. The present invention is also a lens coated with the above primer layer-forming composition, that is, a lens provided with a primer layer using the above primer layer-forming composition.

[0052] As a method for forming the primer layer, there is no particular limitation, and known methods such as dipping method, spin coating method, flow coating, spray method, etc. can be used. The primer layer applied to the lens surface by such a method is then cured by thermal energy (heat conduction, convection, radiation). When curing under the thermal environment of hot air convection, for example, the curing conditions are preferably a treatment at an atmospheric temperature of 80°C to 130°C for 5 to 180 minutes.

[0053] The above lens is not particularly limited as long as it is provided with a primer film using the above composition for forming a primer layer. However, it is preferable that a primer film is provided on the lens substrate and a hard coat film containing a coating composition is applied to the outer layer thereof. The above lens preferably further has an antireflection film or an antifouling coat laminated thereon.

[0054] The above coating composition is not particularly limited as long as it is commonly used. For example, compositions containing inorganic particles such as inorganic oxide fine particles, hydrolyzable group-containing organosilicon compounds (silane coupling agents), their hydrolyzates, or their hydrolysis condensates can be mentioned.

[0055] Examples of the above hydrolyzable group-containing organosilicon compounds include γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, tetraethoxysilane, methyltriethoxysilane, 1,2-bis(triethoxysilyl)ethane, vinyltrimethoxysilane, (meth)acryloxypropyltrimethoxysilane, etc.

[0056] Examples of the inorganic oxide fine particles include oxide fine particles of zirconium, silicon, tin, titanium, cerium, etc., or composite fine particles thereof.

[0057] The refractive index of the above lens is preferably 1.50 to 1.74. More preferably, it is 1.60 to 1.67.

[0058] The above lens preferably has a haze of 0.5% or less as measured by a haze meter. More preferably, it is 0.4% or less.

[0059] As the material of the above lens, plastic lenses having the molecular structure of resins such as aliphatic allyl carbonate-based, polyamide-based, polyurea-based, methacrylate-based, aromatic allyl carbonate-based, polycarbonate-based, polyurethane-based, polythiourethane-based, episulfide-based, and thioepoxy-based are commercially available, and these can be preferably used. The form in which the primer layer-forming composition of the present invention is used for plastic lens applications is one of the preferred embodiments of the present invention.

[0060] The above lens is not particularly limited, but is preferably used for glasses. The form in which the above lens is an eyeglass lens is one of the preferred embodiments of the present invention.

Examples

[0061] The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to only these examples. Unless otherwise specified, "parts" means "parts by mass" and "%" means "% by mass".

[0062] <Physical Property Evaluation> The physical properties, etc. of the obtained zirconium element-containing metal oxide (A) and the primer layer-forming composition were evaluated according to the following procedure.

[0063] <Average Particle Size of Zirconium Element-Containing Metal Oxide> The average particle size of the oxide in the dispersion of the zirconium element-containing metal oxide was measured by the dynamic light scattering method (UPA-UT manufactured by Nikkiso Co., Ltd.), and the values of D50, D90, and Dmax were calculated.

[0064] <pH of Dispersion of Zirconium Element-Containing Metal Oxide> A water dispersion of a metal oxide containing 30 mass% of zirconium element was measured at room temperature (25 °C) using a pH meter equipped with a glass electrode.

[0065] <Weight change rate (%) of the water-based polyurethane resin before and after the solvent resistance test> The weight change rate (%) of the resin before and after the solvent resistance test was determined by the following procedures 1) to 7). 1) Measure the tare weight of a slide glass substrate with a size of 76 × 26 mm and a thickness of 1.2 to 1.5 mm (W 0 ). 2) Apply the resin onto the slide glass substrate at a speed of 130 mm / min by the dipping method. 3) Heat the slide glass substrate coated with the resin at 90 °C for 10 minutes. 4) After heating, measure the tare weight of the slide glass substrate (W 1 ). 5) Immerse it in a liquid of methanol:propylene glycol monomethyl ether = 3:1 at 25 °C for 10 minutes. 6) After immersion, measure the tare weight of the slide glass substrate (W 2 ). 7) Substitute the values of W 1 , W 2 into the following formula to obtain the weight change rate. Weight change rate = [(W 2 - W 1 ) / (W 1 - W 0 )] × 100

[0066] <Haze and total light transmittance of the cured film of the primer layer-forming composition> The haze and total light transmittance of the cured film of the primer layer-forming composition were measured using a haze meter (NDH4000 manufactured by Nippon Denshoku Industries Co., Ltd.). Samples for measuring the haze and total light transmittance of the cured film of the primer layer-forming composition were prepared by the following procedures 1) to 3). 1) In the method for preparing the primer layer-forming composition described in the examples and comparative examples, the amount of water added was reduced, and the solid content concentration of the primer layer-forming composition was adjusted to 22.5 mass%. 2) The primer layer-forming composition obtained in the above procedure 1) was applied onto the slide glass substrate at a speed of 130 mm / min by the dipping method. 3) After the application, the slide glass substrate was heated at 90 °C for 10 minutes to be cured, and a cured film of the primer layer-forming composition with a film thickness of 3 μm for haze and total light transmittance measurement was formed on the slide glass substrate.

[0067] <Refractive index of the cured film (primer layer) of the primer layer-forming composition> Regarding the refractive index of the cured film (primer layer) of the primer layer-forming composition obtained in the examples and comparative examples, it was measured with a spectroscopic film thickness meter (F20 manufactured by Filmetrics, Ltd.).

[0068] <Confirmation of contamination of the cured film of the primer layer-forming composition to the hard coat (HC) liquid> The presence or absence of contamination of the cured film of the primer layer-forming composition to the hard coat liquid was confirmed by the following procedures 1) to 5). 1) The primer layer-forming composition was applied onto the lens substrate at a speed of 130 mm / min by the dipping method. 2) The lens substrate coated with the primer layer-forming composition was heated at 90 °C for 10 minutes for pre-curing, and a primer layer with a film thickness of 1 μm was formed on the lens substrate. 3) The hard coat liquid described in Production Example 6 was applied onto the lens substrate coated with the primer layer-forming composition at a speed of 130 mm / min by the dipping method. 4) After the lens substrate coated with the hard coat liquid was heated at 90 °C for 10 minutes for pre-curing, it was heated at 120 °C for 2 hours for main curing to form a hard coat layer with a film thickness of 3 μm. 5) The appearance of the lens substrate coated with the primer layer and the hard coat layer was visually evaluated according to the following criteria. 〇: No cloudiness, ×: Cloudiness.

[0069] <Adhesion of the cured film of the primer layer-forming composition> On the surface of a lens substrate coated with a primer layer and a hard coat layer, cuts were made at 1 - mm intervals with a knife to form 100 meshes of 1 square millimeter each. After pressing a cellophane adhesive tape firmly onto these meshes, it was rapidly pulled in a direction 90 degrees to the in - plane direction of the lens substrate. This operation was performed a total of 10 times, and the number of meshes that did not peel off was counted and evaluated according to the following criteria. 〇: The number of meshes that did not peel off is 95 or more. ×: The number of meshes that did not peel off is less than 95.

[0070] <Impact resistance of the cured film of the primer - layer - forming composition> An antireflection layer was formed on the lens substrate coated with the primer layer and the hard coat layer. The formation of the antireflection layer was outsourced to Nidec Corporation. A 16.2 - g steel ball was dropped from a height of 127 cm onto the center of the lens substrate coated with the primer layer, the hard coat layer, and the antireflection layer, and whether it was damaged or not was visually evaluated according to the following criteria. 〇: There are no cracks or breaks in the lens substrate or the coating film. ×: The lens substrate or the coating film is damaged.

[0071] <Appearance of the cured film of the primer - layer - forming composition after the weather resistance test> The lens substrate coated with the primer layer and the hard coat layer was placed in a xenon tester (Ci4000 manufactured by ATLAS), and in accordance with ISO 4892 - 2, the appearance of the lens substrate after 40 hours was visually evaluated according to the following criteria. 〇: There is no change in transparency and no discoloration is observed. ×: The transparency has decreased.

[0072] <Adhesion of the cured film of the primer - layer - forming composition after the weather resistance test> The lens substrate coated with the primer layer and the hard coat layer was placed in a xenon tester (Ci4000 manufactured by ATLAS), and in accordance with ISO 4892 - 2, the adhesion of the lens substrate after 40 hours was evaluated according to the following criteria. 〇: The number of meshes that did not peel off is 95 or more. ×: The number of meshes that did not peel off is less than 95.

[0073] (Production Example 1: Preparation of Aqueous Dispersion (A) of Zirconium Element-Containing Metal Oxide) 0.76 L of an aqueous mixed solution of zirconium oxychloride with a concentration of 0.6 mol / L and yttrium chloride with a concentration of 0.03 mol / L and 0.53 L of an aqueous sodium hydroxide solution with a concentration of 1.9 mol / L were prepared. In advance, the above-mentioned aqueous mixed solution of zirconium oxychloride and yttrium chloride and the aqueous sodium hydroxide solution were simultaneously poured into a precipitation reactor filled with 0.74 L of pure water, and zirconium oxychloride and yttrium chloride were coprecipitated by simultaneous neutralization to obtain a slurry of particles of a coprecipitate of zirconium oxide and yttrium. The obtained slurry was filtered and washed, and repulped with pure water so that the solid content ratio of the slurry was 5.6% by mass in terms of zirconium oxide and yttrium oxide, to obtain 1 L of a slurry. The electrical conductivity of this slurry was 235 μS / cm. 140.8 g of sodium citrate dihydrate (1 mol part with respect to 1 mol part of the total amount of zirconium and yttrium in the above slurry) was added to the above slurry, and hydrothermally treated at 200 °C for 3 hours to obtain a translucent dispersion. This translucent dispersion was washed and concentrated with an ultrafiltration membrane to obtain an aqueous dispersion (A) of zirconium element-containing metal oxide with a zirconium element-containing metal oxide content of 30% by mass, which is a solid solution containing 5.0 mol% of yttrium.

[0074] (Production Example 2: Preparation of Methanol Dispersion (B) of Zirconium Element-Containing Metal Oxide) 10 kg of the aqueous dispersion (A) of zirconium element-containing metal oxide obtained above was concentrated using an ultrafiltration membrane, and an amount of methanol equal to the amount of the filtrate obtained was added to the concentrated dispersion thus obtained. By continuously and simultaneously performing the concentration of the dispersion and the dilution with methanol in parallel, while maintaining the content of the zirconium element-containing metal oxide in the dispersion at 30% by mass, the dispersion medium of the dispersion was replaced from water to methanol to obtain a methanol dispersion (B) of zirconium element-containing metal oxide with a zirconium element-containing metal oxide content of 30% by mass.

[0075] (Production Example 3: Preparation of Aqueous Dispersion (C) of Zirconium Element-Containing Metal Oxide) 0.76 L of an aqueous solution of zirconium oxychloride with a concentration of 0.6 mol / L and 0.53 L of an aqueous solution of sodium hydroxide with a concentration of 1.9 mol / L were prepared. In advance, the above aqueous solution of zirconium oxychloride and the aqueous solution of sodium hydroxide were simultaneously poured into a precipitation reactor filled with 0.74 L of pure water, and zirconium oxychloride was coprecipitated by simultaneous neutralization to obtain a slurry of particles of a coprecipitate of zirconium oxide. The obtained slurry was filtered and washed, and repulped with pure water so that the solid content of the slurry was 5.6% by mass in terms of zirconium oxide to obtain 1 L of a slurry. The electrical conductivity of this slurry was 235 μS / cm. 140.8 g of sodium citrate dihydrate (1 mol part with respect to 1 mol part of zirconium in the above slurry) was added to the above slurry, and hydrothermally treated at 200 °C for 3 hours to obtain a translucent dispersion. This translucent dispersion was washed and concentrated with an ultrafiltration membrane to obtain an aqueous dispersion (C) of a zirconium element-containing metal oxide with a zirconium element-containing metal oxide content of 30% by mass.

[0076] (Production Example 4: Preparation of Aqueous Dispersion (D) of Zirconium Element-Containing Metal Oxide) 90 L of an aqueous mixed solution of zirconium oxychloride with a concentration of 0.6 mol / L and yttrium chloride with a concentration of 0.03 mol / L and 68 L of an aqueous sodium hydroxide solution with a concentration of 1.9 mol / L were prepared. In advance, the above aqueous mixed solution of zirconium oxychloride and yttrium chloride and the aqueous sodium hydroxide solution were simultaneously poured into a precipitation reactor filled with 82 L of pure water, and zirconium oxychloride and yttrium chloride were co-precipitated by simultaneous neutralization to obtain a first aqueous slurry of particles of a co-precipitate of zirconium oxide and yttrium. This first aqueous slurry was filtered and washed, and repulped with pure water so that the solid content was 11% by mass in terms of zirconium oxide and yttrium oxide to obtain 60 L of a second aqueous slurry. The electrical conductivity of this second aqueous slurry was 70 μS / cm. 4.2 kg of acetic acid (1.3 mol parts with respect to 1 mol part of the total amount of zirconium and yttrium in the above slurry) was added to the above second aqueous slurry, and hydrothermally treated at 190 °C for 3 hours to obtain a transparent aqueous dispersion. This transparent dispersion was washed and concentrated with an ultrafiltration membrane to obtain an aqueous dispersion (D) of a zirconium element-containing metal oxide having a content of 30% by mass of a zirconium element-containing metal oxide which is a solid solution containing 4.8 mol% of yttrium.

[0077] (Production Example 5: Preparation of Methanol Dispersion (E) of Zirconium Element-Containing Metal Oxide) 10 kg of the aqueous dispersion (D) of the zirconium element-containing metal oxide obtained above was concentrated using an ultrafiltration membrane, and an amount of methanol equal to the amount of the filtrate obtained was added to the concentrated dispersion thus obtained. By continuously and simultaneously performing the concentration of the dispersion and the dilution with methanol in parallel, while maintaining the content of the zirconium element-containing metal oxide in the dispersion at 30% by mass, the dispersion medium of the dispersion was replaced from water to methanol to obtain a methanol dispersion (E) of a zirconium element-containing metal oxide having a content of 30% by mass of the zirconium element-containing metal oxide.

[0078] Table 1 shows the pH of the aqueous dispersion or methanol dispersion of the zirconium element-containing metal oxide obtained in Production Examples 1 to 5 and the particle diameter of the zirconium element-containing metal oxide. For the pH, in the case of the methanol dispersion, the pH of the aqueous dispersion before ultrafiltration is shown.

[0079]

Table 1

[0080] (Production Example 6: Preparation of Hard Coat Liquid) To 69.7 g of γ-glycidoxypropyltrimethoxysilane, 52.3 g of methanol and 16.0 g of dilute hydrochloric acid (0.1 N) were added dropwise, and hydrolysis was carried out over 48 hours. 45.3 g of propylene glycol monomethyl ether, 115.1 g of a methanol dispersion (E) of a metal oxide containing zirconium element, 1.40 g of tris(2,4-pentanedionato)aluminum(III) as a curing catalyst, and 0.11 g of a surfactant (manufactured by Neos Co., Ltd., trade name "Ftergent 222F") were added, and stirring was carried out for 24 hours to prepare a hard coat liquid.

[0081] <Example 1> To 100.0 g of an aqueous dispersion (A) of a metal oxide containing zirconium element with a zirconium element concentration of 30% by mass, 220.21 g of water, 79.79 g of an aqueous polyurethane resin (manufactured by Nihon Kayaku Co., Ltd., trade name "Evaflanol HA-170") with a nonvolatile content of 37.6% by mass, and 0.20 g of a leveling agent (manufactured by Dow Corning Toray Co., Ltd., trade name "L-7604") were added, and the mixture was stirred to obtain a composition for forming a primer layer. The ratio of the metal oxide containing zirconium element in the solid content of the composition for forming a primer layer was 50% by mass. (Formation of Primer Layer) Two types of commercially available plastic lens substrates (MR-8: manufactured by Mitsui Chemicals, Inc., refractive index of the substrate 1.60, MR-7: manufactured by Mitsui Chemicals, Inc., refractive index of the substrate 1.67) were prepared, and on each lens substrate, the primer layer-forming composition described in Example 1 (solid content concentration 15% by mass) was applied at a speed of 130 mm / min by the dipping method. The lens substrate coated with the primer layer-forming composition was heated at 90 °C for 10 minutes for pre-curing, and then heated at 120 °C for 2 hours for full curing to form a primer layer with a film thickness of 1 μm on the lens substrate. Also, a primer layer with a film thickness of 3 μm was formed on a slide glass substrate in the same manner as above.

[0082] (Formation of primer layer + hard coat layer) Two types of commercially available plastic lens substrates (MR-8: manufactured by Mitsui Chemicals, Inc., refractive index of the substrate 1.60, MR-7: manufactured by Mitsui Chemicals, Inc., refractive index of the substrate 1.67) were prepared, and on each lens substrate, the primer layer-forming composition described in Example 1 (solid content concentration 15% by mass) was applied at a speed of 130 mm / min by the dipping method. The lens substrate coated with the primer layer-forming composition was heated at 90 °C for 10 minutes for pre-curing to form a primer layer with a film thickness of 1 μm on the lens substrate. On the lens substrate coated with the primer layer-forming composition, the hard coat liquid described in Production Example 6 was applied at a speed of 130 mm / min by the dipping method. The lens substrate coated with the hard coat liquid was heated at 90 °C for 10 minutes for pre-curing, and then heated at 120 °C for 2 hours for full curing to form a hard coat layer with a film thickness of 3 μm.

[0083] <Example 2> To 100.0 g of a methanol dispersion (B) of a zirconium element-containing metal oxide with a zirconium element concentration of 30% by mass, a primer layer-forming composition was obtained in the same manner as in Example 1. The ratio of the zirconium element-containing metal oxide in the solid content of the primer layer-forming composition was 50% by mass. The formation of the primer layer and the formation of the primer layer + hard coat layer were produced in the same manner as in Example 1.

[0084] <Example 3> To 100.0 g of an aqueous dispersion (A) of a zirconium element-containing metal oxide with a zirconium element concentration of 30% by mass, 220.21 g of water, 6.0 g of a surfactant (manufactured by BYK-Chemie Japan Co., Ltd., trade name "DISPERBYK-180"), 79.79 g of an aqueous polyurethane resin with a non-volatile content of 37.6% by mass (manufactured by Nichika Chemical Co., Ltd., trade name "Evafanol HA-170"), and 0.20 g of a leveling agent (manufactured by Dow Corning Toray Co., Ltd., trade name "L-7604") were added, and then the mixture was stirred to obtain a primer layer-forming composition. The ratio of the zirconium element-containing metal oxide in the solid content of the primer layer-forming composition was 45% by mass. The formation of the primer layer and the formation of the primer layer + hard coat layer were produced in the same manner as in Example 1.

[0085] <Example 4> To 120.0 g of a methanol dispersion (B) of a zirconium element-containing metal oxide with a zirconium element concentration of 30% by mass, 216.17 g of water, 63.83 g of an aqueous polyurethane resin with a non-volatile content of 37.6% by mass (manufactured by Nichika Chemical Co., Ltd., trade name "Evafanol HA-170"), and 0.20 g of a leveling agent (manufactured by Dow Corning Toray Co., Ltd., trade name "L-7604") were added, and then the mixture was stirred to obtain a primer layer-forming composition. The ratio of the zirconium element-containing metal oxide in the solid content of the primer layer-forming composition was 60% by mass. The formation of the primer layer and the formation of the primer layer + hard coat layer were produced in the same manner as in Example 1.

[0086] <Example 5> To 100.0 g of an aqueous dispersion (A) of a zirconium element-containing metal oxide with a zirconium element concentration of 30% by mass, 210.71 g of water, 89.29 g of an aqueous polyurethane resin (manufactured by Daiichi Kogyo Seiyaku Co., Ltd., trade name "Superflex 170") with a nonvolatile content of 33.6% by mass, and 0.20 g of a leveling agent (manufactured by Dow Corning Toray Co., Ltd., trade name "L-7604") were added. After stirring the mixture, a primer layer-forming composition was obtained. The proportion of the zirconium element-containing metal oxide in the solid content of the primer layer-forming composition was 50% by mass. The formation of the primer layer and the formation of the primer layer + hard coat layer were produced in the same manner as in Example 1.

[0087] <Example 6> To 100.0 g of an aqueous dispersion (C) of a zirconium element-containing metal oxide with a zirconium element concentration of 30% by mass, a primer layer-forming composition was obtained in the same manner as in Example 1. The proportion of the zirconium element-containing metal oxide in the solid content of the primer layer-forming composition was 50% by mass. The formation of the primer layer and the formation of the primer layer + hard coat layer were produced in the same manner as in Example 1.

[0088] <Comparative Example 1> Regarding 100.0 g of an aqueous dispersion (D) of a zirconium element-containing metal oxide with a zirconium element concentration of 30% by mass, an attempt was made to prepare a primer layer-forming composition in the same manner as in Example 1, but aggregates were generated and the primer layer-forming composition could not be prepared.

[0089] The results of various physical property evaluations for Examples 1 to 6 and Comparative Example 1 are shown in Table 2.

[0090]

Table 2

[0091] From the results in Table 2, by using a zirconium element-containing metal oxide in which the content of silicon element is 20 mol% or less with respect to 100 mol% of zirconium element in (A), the average particle diameter is in a predetermined range, and the pH of a 30 mass% aqueous dispersion is 8 to 11, it was confirmed that a composition capable of forming a primer layer having high transparency and a high refractive index can be obtained.

Claims

1. A composition for forming a primer layer containing a zirconium element-containing metal oxide (A) and an aqueous urethane resin (B), wherein the zirconium element-containing metal oxide (A) has an average particle diameter measured by the dynamic light scattering method of 1 to 20 nm, and the pH of a 30% by mass aqueous dispersion of the zirconium element-containing metal oxide (A) is 8 to 11, and the content of silicon element is 20 mol% or less with respect to 100 mol% of zirconium element in (A). A composition for forming a primer layer.

2. The composition for forming a primer layer according to Claim 1, wherein the content ratio of the zirconium element-containing metal oxide (A) is 40 to 80% by mass with respect to 100% by mass of the solid content in the composition for forming a primer layer.

3. The composition for forming a primer layer according to Claim 1, wherein the content ratio of the solid content in the aqueous urethane resin (B) is 20 to 60% by mass with respect to 100% by mass of the solid content in the composition for forming a primer layer.

4. The composition for forming a primer layer according to any one of Claims 1 to 3, wherein the composition for forming a primer layer is used for lens applications.

5. A lens coated with the composition for forming a primer layer according to any one of Claims 1 to 3.

6. A method for producing a composition for forming a primer layer, wherein the production method includes a step of mixing a zirconium element-containing metal oxide (A) and an aqueous urethane resin (B), and the zirconium element-containing metal oxide (A) has an average particle diameter measured by the dynamic light scattering method of 1 to 20 nm, and the pH when it is made into a 30% by mass aqueous dispersion is 8 to 11. A method for producing a composition for forming a primer layer.