Composition for forming a primer layer

Abstract

This invention provides a composition capable of forming a base coating with high transparency and high refractive index. The invention relates to a composition for forming a base coating comprising a zirconium-containing metal oxide (A) and an aqueous urethane resin (B), wherein the zirconium-containing metal oxide (A) has an average particle size of 1-20 nm as determined by dynamic light scattering, a pH of 8-11 for a 30% by mass aqueous dispersion of the zirconium-containing metal oxide (A), and a silicon content of 20 mol% or less relative to 100 mol% of zirconium in (A).

Description

Technical Field

[0001] This invention relates to compositions for forming a base coating. More specifically, it relates to compositions for forming a base coating useful for use in lenses such as eyeglasses. Background Technology

[0002] In recent years, plastic lenses, with their superior lightweight, impact resistance, and processability, have become the mainstream choice for eyeglass lenses. However, plastic lenses are easily scratched due to the presence of a hard coating on the lens substrate. Poor adhesion between the lens substrate and the hard coating can lead to cracking and reduced impact resistance. Therefore, attempts have been made to improve adhesion and impact resistance by adding an undercoat layer between the lens substrate and the hard coating. However, when the refractive index of the undercoat layer does not match that of the lens substrate, interference fringes can occur due to light interference, damaging the appearance. Therefore, a technique has been proposed to match the refractive index of the undercoat layer with that of the lens substrate.

[0003] For example, in Patent Document 1, a coating liquid for use as a base coating is proposed, which contains surface-modified inorganic composite oxide particles. These particles are obtained by surface modification of the inorganic composite oxide particles with an organosilicon compound A (expressed by a given formula) or a partial hydrolysate thereof and an organosilicon compound B (expressed by a given formula) or a partial hydrolysate thereof having a boiling point of 120°C or less at 1 atmosphere. The carbon atom content is 2 to 10 by weight.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2014-152226 Summary of the Invention

[0007] The problem the invention aims to solve

[0008] As mentioned above, although techniques for forming a base coating on lenses have been developed, the increasing demand for thinner / lighter lenses has led to the continuous development of higher refractive index plastic lens substrates. If the surface of inorganic composite oxide particles is coated with other elements such as silicon as in Patent Document 1, the refractive index of the inorganic composite oxide particles will decrease, which presents a problem that makes it difficult to match the high refractive index of plastic lens substrates. Therefore, there is a need for a composition for forming a base coating with high refractive index and high transparency.

[0009] The present invention was made in view of the above-mentioned situation, and its object is to provide a composition capable of forming a base coating with high transparency and high refractive index.

[0010] Problem Solving Methods

[0011] The inventors conducted various studies on compositions for forming base coatings for lenses, etc., and found that by using a zirconium-containing metal oxide in a composition comprising a zirconium-containing metal oxide and an aqueous urethane resin, wherein the silicon content is 20 mol% or less relative to 100 mol% of zirconium in (A), the average particle size is within a given range, and the pH of the 30% by mass aqueous dispersion is 8 to 11, a base coating with high transparency and high refractive index can be formed on a lens. Thus, the above-mentioned problems were effectively solved, and the present invention was completed.

[0012] The present invention includes compositions for forming a base coating layer, etc.

[0013] [1] A composition for forming a base coating, comprising a zirconium-containing metal oxide (A) and an aqueous urethane resin (B), wherein,

[0014] The average particle size of the zirconium-containing metal oxide (A), as determined by dynamic light scattering, is 1-20 nm. The pH of a 30% by mass aqueous dispersion of the zirconium-containing metal oxide (A) is 8-11. The content of silicon is less than 20 mol% relative to 100 mol% of zirconium in (A).

[0015] [2] According to the composition for forming the base coating layer described in [1] above, wherein,

[0016] The content of the zirconium-containing metal oxide (A) is 40 to 80% by mass relative to 100% by mass of the solid components in the composition for forming the base coating.

[0017] [3] The composition for forming the base coating layer according to [1] or [2] above, wherein,

[0018] The solid content of the above-mentioned waterborne urethane resin (B) is 20 to 60% by mass relative to 100% by mass of the solid content in the composition for forming the base coating.

[0019] [4] The composition for forming a base coating according to any one of [1] to [3] above, wherein,

[0020] The above-mentioned composition for forming the base coating is used for lens applications.

[0021] [5] A lens having a base coating forming composition as described in any one of [1] to [3] above.

[0022] [6] A method for manufacturing a composition for forming a base coating, the method comprising: a step of mixing a zirconium-containing metal oxide (A) with an aqueous urethane resin (B),

[0023] The average particle size of the zirconium-containing metal oxide (A), as determined by dynamic light scattering, is 1–20 nm, and the pH of the 30% by mass aqueous dispersion is 8–11.

[0024] The effects of the invention

[0025] The composition for forming a base coating of the present invention has the above-described structure and is capable of forming a base coating with high transparency and high refractive index. Therefore, it can be suitably used for base coatings of lenses and the like. Detailed Implementation

[0026] The preferred embodiments of the present invention will be described in detail below. However, the present invention is not limited to the following description and can be appropriately modified and applied without changing the spirit of the invention. It should be noted that combinations of two or more preferred embodiments of the present invention described below are also preferred embodiments of the present invention.

[0027] [Composition for forming a base coating]

[0028] The primer coating composition of the present invention is a primer coating composition comprising a zirconium-containing metal oxide (A) and an aqueous urethane resin (B), wherein the zirconium-containing metal oxide (A) has an average particle size of 1 to 20 nm as determined by dynamic light scattering, the pH of a 30% by mass aqueous dispersion of the zirconium-containing metal oxide (A) is 8 to 11, and the content of silicon is 20 mol% or less relative to 100 mol% of zirconium in (A).

[0029] For the composition for forming the base coating of the present invention, since the pH of the 30% by mass aqueous dispersion of the zirconium-containing metal oxide (A) which is added to the composition as a raw material is within the above range, and the average particle size of the zirconium-containing metal oxide (A) is within the above range, the transparency is excellent, and since the silicon content is within the above range, the refractive index is high.

[0030] Because the composition for forming the base coating of the present invention has the above-described structure, the base coating formed thereon on lenses or the like has excellent solvent resistance, adhesion, weather resistance, and impact resistance.

[0031] In the composition for forming the base coating of the present invention, the content of silicon is 20 mol% or less relative to 100 mol% of zirconium in the zirconium-containing metal oxide (A). This sufficiently improves the refractive index. The silicon content is preferably 10 mol% or less, more preferably 5 mol% or less, further preferably 1 mol% or less, particularly preferably 0.1 mol% or less, and most preferably 0 mol%.

[0032] For the above-mentioned primer coating forming composition, the content of zirconium-containing metal oxide (A) is preferably 40 to 80% by mass relative to 100% by mass of the solid components (non-volatile components) in the primer coating forming composition. More preferably, it is 43 to 75% by mass, even more preferably, it is 44 to 73% by mass, and particularly preferably, it is 45 to 70% by mass.

[0033] For the above-mentioned primer coating composition, the content of the solid component in the aqueous urethane resin (B) is preferably 20 to 60% by mass relative to 100% by mass of the solid component in the primer coating composition. More preferably, it is 25 to 57% by mass, even more preferably, it is 27 to 56% by mass, and particularly preferably, it is 30 to 55% by mass.

[0034] For the above-mentioned composition for forming the base coating, the content of the solid component in the aqueous urethane resin (B) is preferably 25 to 150% by mass relative to 100% by mass of the zirconium-containing metal oxide (A). More preferably, it is 30 to 145% by mass, even more preferably, it is 35 to 140% by mass, and particularly preferably, it is 40 to 130% by mass.

[0035] The above-mentioned primer coating forming composition preferably incorporates a solvent to adjust the solid content concentration of the primer coating forming composition. The solid content concentration of the primer coating forming composition is not particularly limited, but is preferably 5-50% by mass. More preferably, it is 5-45% by mass, even more preferably 6-40% by mass, and particularly preferably 7-30% by mass.

[0036] The proportion of solvent in the above-mentioned primer coating composition is preferably obtained by subtracting the concentration of the above-mentioned solid components from 100% by mass of the composition.

[0037] The primer coating forming composition of the present invention may contain a zirconium-containing metal oxide (A), an aqueous urethane resin (B), and other components besides a solvent. The proportion of these other components is not particularly limited, but is preferably 0-30% by mass, more preferably 0-28% by mass, further preferably 0-25% by mass, and particularly preferably 0-20% by mass, relative to 100% by mass of the solid content in the primer coating forming composition.

[0038] For the composition for forming the base coating of the present invention, it is preferable that the refractive index is 1.55 to 1.74 when the composition is formed into a cured film with a thickness of 1 μm. Preferably, the refractive index is 1.58 to 1.70.

[0039] The refractive index of the cured film can be determined using the method described in the examples.

[0040] Regarding the composition for forming the base coating of the present invention, it is preferable that the total light transmittance is 94.0 to 100.0% when the composition is formed into a cured film with a thickness of 3 μm. As for the total light transmittance, it is preferably 95.0 to 100.0%.

[0041] The total light transmittance of the cured film can be measured using the method described in the examples.

[0042] The essential and optional components contained in the primer coating composition of the present invention will be further described below.

[0043] <Zirconium-containing metal oxides (A)>

[0044] The aforementioned zirconium-containing metal oxide (A) is not particularly limited in that it contains zirconium and oxygen atoms, and may include elements other than zirconium and oxygen atoms. Other elements, besides silicon mentioned above, include at least one stabilizing element selected from sodium, magnesium, aluminum, potassium, titanium, hafnium, and rare earth elements. By including the aforementioned stabilizing elements in the zirconium-containing metal oxide (A), the thermal stability of the metal oxide (A) is further improved.

[0045] Specific examples of the aforementioned rare earth elements include Y, La, Ce, Pr, Nd, Sm, Eu, Tb, Dy, and Ho.

[0046] The content of the other elements in the zirconium-containing metal oxide (A) is not particularly limited as long as the content of the other elements in the composition is 20 mol% or less relative to 100 mol% of zirconium, and is preferably 0 to 20 mol% relative to 100 mol% of zirconium. More preferably, it is 0 to 10 mol%, and even more preferably, it is 0 to 5 mol%.

[0047] In one embodiment, the content of the other elements mentioned above can be greater than 0 mol%.

[0048] The average particle size (D50) of the zirconium-containing metal oxide (A) measured by dynamic light scattering is 1 to 20 nm in the dispersion state. When the average particle size is 1 nm or more, the aggregation of primary particles can be sufficiently suppressed. Furthermore, when the average particle size is 20 nm or less, the reduction in transparency of the base coating can be sufficiently suppressed. More preferably, it is 1 to 19 nm, more preferably 1 to 18 nm, and even more preferably 2 to 17 nm. Furthermore, the D50 / D90 ratio of the zirconium-containing metal oxide is more preferably 0.2 to 1.0, and even more preferably 0.3 to 1.0. Thus, by using a zirconium-containing metal oxide with such a small average particle size (D50) and narrow particle size distribution, the resulting composition for forming the base coating has higher transparency.

[0049] Furthermore, the aforementioned zirconium-containing metal oxide (A) can be surface-treated with inorganic or organic compounds. Examples of inorganic compounds include silicon oxide and aluminum oxide. Examples of organic compounds include silane coupling agents, titanate coupling agents, and surfactants with acidic groups such as phosphate groups, carboxylic acid groups, and phosphonic acid groups.

[0050] For the zirconium-containing metal oxide (A) mentioned above, the pH of the 30% by mass aqueous dispersion added before the composition is 8 to 11. This improves the transparency of the resulting base coating. A pH of 8.5 to 11 is more preferred, and 9 to 11 is even more preferred.

[0051] The pH value mentioned above can be measured at room temperature (25°C) using a pH meter with a glass electrode.

[0052] The morphology of the zirconium-containing metal oxide (A) is not particularly limited, but crystallinity is preferred. As a crystal structure, cubic, tetragonal, monoclinic, etc., are preferred, but various crystal structures are also possible. By incorporating the above-mentioned crystal structure into the morphology of the zirconium-containing metal oxide (A), the refractive index and hardness of the zirconium-containing metal oxide (A) are further improved.

[0053] The manufacturing method of the aforementioned zirconium-containing metal oxide (A) is not particularly limited. For example, the following methods can be used: heating and hydrolyzing an aqueous solution of zirconium salt (hydrolysis method); adding an alkali to an aqueous solution of zirconium salt to prepare zirconium hydroxide and then deflocculating it (neutralization coprecipitation method); adding acid and alkali to zirconium hydroxide and then performing hydrothermal treatment (hydrothermal synthesis method), etc.

[0054] As a method for manufacturing the aforementioned zirconium-containing metal oxide (A), a preferred method is to perform the following steps: a neutralization co-precipitation step in which an alkali is added to an aqueous solution of a zirconium salt to form a hydroxide, and the hydroxide is deflocculated; and a hydrothermal step in which an acid or its salt is added to the product obtained in the neutralization co-precipitation step and hydrothermally treated.

[0055] The zirconium salt used in the above-mentioned neutralization and co-precipitation process is not particularly limited as long as it contains zirconium, and is preferably a chloride, chloride, sulfate, nitrate, etc. Chloride and chloride are more preferred. Examples of zirconium compounds used as raw materials in the manufacture of slurries containing zirconium compounds include hydroxides, hydroxide oxides, chlorides, sulfides, sulfates, nitrates, carbonates, bicarbonates, acetates, phosphates, oxalates, butyrates, selenates, iodates, fluorides, and chloride oxides. Among these, water-soluble zirconium compounds suitable for manufacturing are preferred, namely chloride oxides, chlorides, sulfates, nitrates, and acetates.

[0056] When the aforementioned zirconium-containing metal oxide (A) contains elements other than zirconium and oxygen atoms, it is preferable to add a salt of other elements during the aforementioned neutralization and co-precipitation process. Examples of other element salts include chlorides, chlorides, sulfates, nitrates, and acetates.

[0057] There are no particular restrictions on the alkali used in the above-mentioned neutralization and co-precipitation process. Examples include hydroxides of alkali metals and alkaline earth metals such as sodium hydroxide, potassium hydroxide, and calcium hydroxide; ammonia; and organic amines. Among these, hydroxides of alkali metals such as sodium hydroxide and potassium hydroxide are preferred.

[0058] The amount of alkali used in the above-mentioned neutralization and co-precipitation process is not particularly limited, but is preferably 10 to 1000 mol% relative to the total of zirconium and the other elements mentioned above.

[0059] There are no particular limitations on the acids or their salts used in the above-mentioned hydrothermal process, and examples 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, and their salts. Among these, organic acids and their salts are preferred.

[0060] The amount of acid or its salt used in the above-mentioned hydrothermal process is not particularly limited, but is preferably 50 to 1000 mol% relative to the total of zirconium and the other elements mentioned above, and more preferably 100 to 500 mol%.

[0061] There are no particular limitations on the hydrothermal temperature used in the above-mentioned hydrothermal process, but it is preferably 170~230℃. More preferably, it is 175~220℃.

[0062] There is no particular limitation on the hydrothermal treatment time in the above-mentioned hydrothermal process, but it is preferably 1 to 10 hours, and more preferably 1.5 to 6 hours.

[0063] The method for manufacturing the zirconium-containing metal oxide (A) preferably includes a cleaning step after the neutralization and co-precipitation step and / or the hydrothermal step.

[0064] The cleaning method used in the above cleaning process is not particularly limited and can be carried out by commonly used methods. For example, after the above neutralization and co-precipitation process, a cleaning method based on filtration / washing is preferred. In addition, after the hydrothermal process, an ultrafiltration membrane is preferred.

[0065] When a zirconium-containing metal oxide (A) is manufactured by the above manufacturing method, it can be obtained in the form of an aqueous dispersion. Therefore, when used in the composition for forming the base coating of the present invention, it can be replaced by an organic solvent.

[0066] There are no particular limitations on the organic solvents mentioned above. Examples include: alcohols such as methanol, ethanol, and isopropanol; ketones such as acetone; esters such as ethyl lactate; and polyols and their ethers such as ethylene glycol, ethylene glycol monomethyl ether, ethylene glycol monobutyl ether, propylene glycol monomethyl ether, and propylene glycol monomethyl ether acetate. Solvents such as alkanes and tetrahydrofurans, which are cyclic ethers, have good compatibility with water. These can be used alone or in combination. Additionally, 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 also have good compatibility with these organic solvents, can be used in appropriate combinations.

[0067] Preferably, it is a lower alcohol with 1 to 3 carbon atoms, and more preferably methanol.

[0068] <Waterborne carbamate resin (B)>

[0069] The aqueous urethane resin (B) included in the primer coating forming composition of the present invention can be any polymer containing water and having urethane bonds, without particular limitation. Examples include: self-emulsifying aqueous urethane resins having hydrophilic groups such as anionic, cationic, and nonionic groups; and forced-emulsifying aqueous urethane resins that are forcibly dispersed in water using an emulsifier. Among these, self-emulsifying aqueous urethane resins are preferred. The average particle size of the aqueous urethane resin is preferably 0.06 μm or less. It should be noted that commercially available products can also be used as the aqueous urethane resin. Examples of commercially available products include the EVAFANOL series manufactured by Nichika Chemical Co., Ltd., the Superflex series manufactured by Daiichi Kogyo Pharmaceutical Co., Ltd., and the ADEKABONTIGHTER series manufactured by ADEKA Corporation.

[0070] Examples of the aforementioned waterborne urethane resin (B) include: non-yellowing isocyanate-polyester waterborne urethane resin, non-yellowing isocyanate-polyether waterborne urethane resin, non-yellowing isocyanate-polycarbonate waterborne urethane resin, non-yellowing isocyanate-polyester / ether waterborne urethane resin, non-yellowing isocyanate-polyester / polycarbonate waterborne urethane resin, aromatic isocyanate-polyester waterborne urethane resin, aromatic isocyanate-polycarbonate waterborne urethane resin, aromatic isocyanate-polyester / ether waterborne urethane resin, and aromatic isocyanate-polyester / polycarbonate waterborne urethane resin. Among these, a non-yellowing waterborne urethane resin is preferred, as it exhibits superior solvent resistance and weather resistance. As described above, the waterborne urethane resin (B) is more preferably a non-yellowing isocyanate-polyester waterborne urethane resin, a non-yellowing isocyanate-polyester / ether waterborne urethane resin, or a non-yellowing isocyanate-polycarbonate waterborne urethane resin.

[0071] There are no particular limitations on the solvents that can be used in the composition for forming the base coating of the present invention, and water and organic solvents are examples. There are no particular limitations on the types of organic solvents, and examples include alcohol solvents, ketone solvents, ether solvents, ester solvents, hydrocarbon solvents, halogenated hydrocarbon solvents, amide solvents, sulfone solvents, and sulfoxide solvents.

[0072] The solvent is preferably water and / or a water-soluble organic solvent, and may be a mixture of water and a water-soluble organic solvent. More preferably, the solvent is water, methanol, ethanol, isopropanol, or propylene glycol monomethyl ether.

[0073] The aforementioned water-soluble organic solvent is an organic solvent that is compatible with water. More specifically, it refers to an organic solvent that has a solubility of 10% by mass or more, preferably 50% by mass or more, in water at 25°C.

[0074] Examples of water-soluble organic solvents 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 hexanediol; polyols and their ethers such as ethylene glycol monomethyl ether, ethylene glycol monoisopropyl ether, ethylene glycol monoethyl ether, ethylene glycol monon-propyl ether, ethylene glycol monon-butyl ether, ethylene glycol monotert-butyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether (1-methoxy-2-propanol), propylene glycol monon-propyl ether, and propylene glycol monomethyl ether acetate; ketones such as acetone, diacetone alcohol, and acetylacetone; and amides such as N-methyl-2-pyrrolidone.

[0075] The composition for forming the base coating of the present invention may contain a zirconium-containing metal oxide (A), an aqueous urethane resin (B), and other components besides a solvent. There are no particular limitations on these other components, and examples include oxides of metals other than zirconium, dispersants, surface treatment agents, leveling agents, crosslinking agents, chelating agents, antistatic agents, defoamers, flame retardants, ultraviolet absorbers, anti-aging agents, coating conditioners, light stabilizers, antioxidants, colorant inhibitors, dyes, and various other additives.

[0076] Examples of 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 include oxides of titanium oxide, antimony oxide, zinc oxide, and cerium oxide, or composite oxides thereof. These are commercially available products, such as sols containing particles of these metal oxides dispersed in water or organic solvents.

[0077] Examples of such dispersants include anionic surfactants of the sulfate ester type, carboxylic acid type, and phosphate ester type, cationic surfactants of the quaternary ammonium type, nonionic surfactants of the alkyl ether type, amphoteric surfactants of the alkyl betaine type, and polymeric surfactants.

[0078] Examples of leveling agents include silicone leveling agents, fluorinated leveling agents, acrylic leveling agents, and acrylic silicone leveling agents.

[0079] [Method for manufacturing composition for primer coating]

[0080] The present invention is also a method for manufacturing a composition for forming a base coating, the method comprising: mixing a zirconium-containing metal oxide (A) with an aqueous urethane resin (B), wherein the zirconium-containing metal oxide (A) has an average particle size of 1 to 20 nm as determined by dynamic light scattering and the pH of the 30% by mass aqueous dispersion is 8 to 11.

[0081] For the mixing process of the zirconium-containing metal oxide (A) and the aqueous urethane resin (B) mentioned above, it is not particularly limited to simply mixing the zirconium-containing metal oxide (A) and the aqueous urethane resin (B), but it is preferable to mix by stirring or the like.

[0082] The zirconium-containing metal oxide (A) used in the above mixing process has an average particle size of 1-20 nm as determined by dynamic light scattering, and the pH of the 30% by mass aqueous dispersion is 8-11.

[0083] The method for manufacturing the zirconium-containing metal oxide (A) is as described above. It is sufficient to prepare a 30% by mass aqueous dispersion of the zirconium-containing metal oxide (A) before mixing with the aqueous urethane resin (B) with a pH of 8 to 11. When mixing with the aqueous urethane resin (B), a substance that has been replaced with an organic solvent such as methanol can be used.

[0084] There are no particular limitations on the amount of zirconium-containing metal oxide (A) and waterborne urethane resin (B) used in the above mixing process, but they are preferably added in the above-mentioned preferred proportions in the composition for forming the base coating.

[0085] [Use of the composition for forming the primer coating]

[0086] The composition for forming the base coating of the present invention can be suitably used as a base coating (base film) between a lens substrate and a hard coating in optical plastics such as lenses.

[0087] The present invention is also a lens coated with the above-mentioned base coating forming composition, that is, a lens with a base coating provided using the above-mentioned base coating forming composition.

[0088] There are no particular limitations on the method used to form the aforementioned base coating; known methods such as dip coating, spin coating, flow coating, and spray coating can be used. The base coating applied to the lens surface using such methods can then be cured by heat energy (heat transfer, convection, radiation). For example, when curing is carried out in a hot air convection environment, the preferred curing conditions are treatment at an atmospheric temperature of 80°C to 130°C for 5 to 180 minutes.

[0089] There are no particular limitations on the above-mentioned lenses as long as they are lenses with a base coating film provided by the above-mentioned base coating forming composition. Preferably, a lens is a lens with a base coating film provided on the lens substrate and a hard coating film containing a coating composition applied to its outer layer.

[0090] The aforementioned lenses are preferably further laminated with an anti-reflective film and an anti-fouling coating.

[0091] As for the above-mentioned coating composition, there are no particular limitations as long as it is a commonly used composition. Examples include compositions containing inorganic particles such as inorganic oxide microparticles, organosilicon compounds (silane coupling agents) containing hydrolyzable groups, their hydrolysates, or their hydrolysates.

[0092] Examples of organosilicon compounds containing hydrolyzable groups include γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, tetraethoxysilane, methyltriethoxysilane, 1,2-bis(triethoxysilyl)ethane, vinyltrimethoxysilane, and (meth)acryloyloxypropyltrimethoxysilane.

[0093] Examples of inorganic oxide particles include oxide particles of zirconium, silicon, tin, titanium, cerium, etc., or composite particles thereof.

[0094] The refractive index of the above-mentioned lens is preferably 1.50~1.74, more preferably 1.60~1.67.

[0095] The haze of the above-mentioned lens, as measured by a haze meter, is preferably 0.5% or less, more preferably 0.4% or less.

[0096] Plastic lenses with molecular structures of resins such as aliphatic allyl carbonates, polyamides, polyureas, methacrylates, aromatic allyl carbonates, polycarbonates, polyurethanes, polysulfides, cyclic sulfides, and thioepoxys are commercially available and can be used appropriately as raw materials for the aforementioned lenses.

[0097] The use of the undercoat forming composition of the present invention for use in plastic lenses is one of the preferred embodiments of the present invention.

[0098] There are no particular restrictions on the use of the aforementioned lenses, but they are preferably used for eyeglasses.

[0099] The use of spectacle lenses as described above is one of the preferred embodiments of the present invention.

[0100] Example

[0101] The present invention will be described in more detail below with reference to specific embodiments, but the present invention is not limited to these embodiments. It should be noted that, unless otherwise specified, "parts" means "parts by mass" and "%" means "% by mass".

[0102] <Physical Property Evaluation>

[0103] The physical properties of the obtained zirconium-containing metal oxide (A) and the composition for forming the base coating were evaluated through the following steps.

[0104] <Average particle size of zirconium-containing metal oxides>

[0105] The average particle size of the zirconium-containing metal oxide in the dispersion was determined by dynamic light scattering method (UPA-UT manufactured by Nikkiso Co., Ltd.), and the values ​​of D50, D90 and Dmax were calculated.

[0106] pH of dispersions of zirconium-containing metal oxides

[0107] A 30% by mass aqueous dispersion of zirconium-containing metal oxides was determined at room temperature (25°C) using a pH meter with a glass electrode.

[0108] <Weight change rate (%) of waterborne polyurethane resin before and after solvent resistance test>

[0109] The weight change rate (%) of the resin before and after the solvent resistance test was determined by the following steps 1) to 7).

[0110] 1) Measure the tare weight (W0) of a glass slide substrate with dimensions of 76×26mm and a thickness of 1.2~1.5mm.

[0111] 2) Apply resin to the glass slide substrate by impregnation at a speed of 130 mm / min.

[0112] 3) Heat the resin-coated glass slide substrate at 90°C for 10 minutes.

[0113] 4) After heating, measure the tare weight (W1) of the glass slide substrate.

[0114] 5) Immerse in a liquid of methanol:propylene glycol monomethyl ether = 3:1 at 25°C for 10 minutes.

[0115] 6) After impregnation, measure the tare weight (W2) of the glass slide substrate.

[0116] 7) Substitute the values ​​of W1 and W2 obtained above into the following formula to calculate the rate of change of weight.

[0117] Rate of change of weight = [(W2-W1) / (W1-W0)] × 100

[0118] <Haze and total light transmittance of the cured film of the composition for forming the primer>

[0119] The haze and total light transmittance of the cured film of the primer coating composition were measured using a haze meter (NDH4000 manufactured by Nippon Denshoku Kogyo Co., Ltd.).

[0120] Samples for measuring the haze and total light transmittance of the cured film of the primer coating composition are prepared by following steps 1) to 3).

[0121] 1) In the method for preparing the primer coating forming composition described in the examples and comparative examples, the amount of water added is reduced and the concentration of the solid components of the primer coating forming composition is adjusted to 22.5% by mass.

[0122] 2) The composition for forming the base coating obtained in step 1) above was applied to a glass slide substrate by an immersion method at a speed of 130 mm / min.

[0123] 3) After coating, the glass slide substrate is heated at 90°C for 10 minutes to cure it, and a cured film of the undercoat layer forming composition with a thickness of 3μm for measuring haze and total light transmittance is formed on the glass slide substrate.

[0124] <Refractive index of the cured film (base coat) of the composition for forming the base coat>

[0125] The refractive index of the cured film (base coat) of the base coat forming composition obtained in the examples and comparative examples was measured using a spectrophotometer (Filmetrics F20).

[0126] <Confirmation of contamination of the hard coating (HC) liquid by the cured film of the primer coating composition>

[0127] The presence or absence of contamination of the hard coating liquid by the cured film of the primer coating composition was confirmed through the following steps 1) to 5).

[0128] 1) A composition for forming a base coating was applied to a lens substrate by an immersion method at a speed of 130 mm / min.

[0129] 2) The lens substrate coated with the composition for forming the primer coating was pre-cured by heating at 90°C for 10 minutes, and a primer coating with a film thickness of 1 μm was formed on the lens substrate.

[0130] 3) The hard coating liquid described in Manufacturing Example 6 was applied to a lens substrate coated with a primer coating forming composition by an immersion method at a speed of 130 mm / min.

[0131] 4) After pre-curing the lens substrate coated with hard coating liquid at 90°C for 10 minutes, it was then formally cured at 120°C for 2 hours, forming a hard coating with a film thickness of 3μm.

[0132] 5) The appearance of the lens substrate coated with the base coat and hard coat was evaluated by visual inspection according to the following criteria.

[0133] ○: No fog or turbidity; ×: Fog or turbidity.

[0134] <Adhesion of the cured film of the composition for forming the primer>

[0135] On the surface of the lens substrate coated with a base coat and a hard coat, cuts are made at 1mm intervals to form 100 grids of 1 square millimeter. Cellophane adhesive tape is pressed firmly onto these grids, and then pulled sharply in a direction of 90 degrees relative to the in-plane direction of the lens substrate. This operation is performed a total of 10 times. The number of grids that are not peeled off is counted, and the evaluation is carried out according to the following criteria.

[0136] ○: The number of unstripped cells is 95 or more; ×: The number of unstripped cells is less than 95.

[0137] Impact resistance of the cured film of the composition for forming the primer coating.

[0138] An anti-reflective layer was formed on a lens substrate coated with a base coat and a hard coat. The formation of the anti-reflective layer was outsourced to Nidek.

[0139] A 16.2g steel ball was dropped from a height of 127cm onto the center of a lens substrate coated with a base layer, a hard layer, and an anti-reflective layer. The breakage was evaluated by visual inspection according to the following criteria.

[0140] ○: The lens substrate and coating are free from cracks or fissures; ×: The lens substrate and coating are damaged.

[0141] <Appearance of the cured film of the primer coating composition after weather resistance test>

[0142] For lens substrates coated with a base coat and a hard coat, the appearance of the lens substrates after 40 hours was evaluated by visual inspection using a xenon lamp testing machine (ATLAS Ci4000) according to ISO 4892-2 and based on the following criteria.

[0143] ○: No change in transparency, and no color change was observed; ×: Transparency decreased.

[0144] <Adhesion of the cured film of the primer coating composition after weather resistance test>

[0145] For lens substrates coated with a base coat and a hard coat, the adhesion of the lens substrates after 40 hours was evaluated using a xenon lamp testing machine (ATLAS Ci4000) according to ISO 4892-2, based on the following criteria.

[0146] ○: The number of unstripped cells is 95 or more; ×: The number of unstripped cells is less than 95.

[0147] (Example 1: Preparation of an aqueous dispersion (A) of a zirconium-containing metal oxide)

[0148] 0.76 L of a mixed aqueous solution of 0.6 mol / L zirconium oxychloride and 0.03 mol / L yttrium chloride, and 0.53 L of a 1.9 mol / L sodium hydroxide aqueous solution were prepared. The above-mentioned mixed aqueous solution of zirconium oxychloride and yttrium chloride and the sodium hydroxide aqueous solution were simultaneously injected into a precipitation reactor pre-filled with 0.74 L of pure water. Simultaneous neutralization caused co-precipitation of zirconium oxychloride and yttrium chloride, resulting in a slurry of co-precipitate particles of zirconium oxide and yttrium. The obtained slurry was filtered and washed to achieve a solid content of 5.6% by mass (calculated based on the conversion of zirconium oxide and yttrium oxide), and then re-slurried with pure water to obtain 1 L of slurry. The conductivity of this slurry was 235 μS / cm. 140.8 g of sodium citrate dihydrate (1 mole relative to the total molar amount of zirconium and yttrium in the above slurry) was added to the slurry, and the mixture was hydrothermally treated at 200 °C for 3 hours to obtain a translucent dispersion. The semi-transparent dispersion was washed and concentrated using an ultrafiltration membrane to obtain an aqueous dispersion (A) of zirconium-containing metal oxide with a zirconium content of 30% by mass. The zirconium-containing metal oxide is a solid solution containing 5.0 mol% yttrium.

[0149] (Example 2: Preparation of methanol dispersion (B) of zirconium-containing metal oxide)

[0150] 10 kg of the aqueous dispersion (A) of zirconium-containing metal oxide obtained above was concentrated using an ultrafiltration membrane. An equal amount of methanol as the filtrate was added to the concentrated dispersion. The concentration and methanol-based dilution of the dispersion were carried out continuously and simultaneously. Thus, while maintaining the content of zirconium-containing metal oxide in the dispersion at 30% by mass, the dispersion medium of the dispersion was replaced from water to methanol, resulting in a methanol dispersion (B) of zirconium-containing metal oxide with a content of 30% by mass.

[0151] (Example 3: Preparation of an aqueous dispersion (C) of a zirconium-containing metal oxide)

[0152] 0.76 L of a 0.6 mol / L zirconium oxychloride aqueous solution and 0.53 L of a 1.9 mol / L sodium hydroxide aqueous solution were prepared. The zirconium oxychloride aqueous solution and sodium hydroxide aqueous solution were simultaneously injected into a precipitation reactor pre-filled with 0.74 L of pure water. Simultaneous neutralization caused co-precipitation of zirconium oxychloride, resulting in a slurry of zirconium oxide co-precipitate particles. The obtained slurry was filtered and washed, and then re-slurried with pure water to achieve a solid content of 5.6% by mass (calculated as zirconium oxide), yielding 1 L of slurry. The conductivity of this slurry was 235 μS / cm. 140.8 g of sodium citrate dihydrate (1 mole relative to 1 mole of zirconium in the slurry) was added to the slurry, and the mixture was hydrothermally treated at 200 °C for 3 hours to obtain a semi-transparent dispersion. This semi-transparent dispersion was washed and concentrated using an ultrafiltration membrane to obtain an aqueous dispersion (C) containing 30% by mass of zirconium-containing metal oxides.

[0153] (Example 4: Preparation of an aqueous dispersion (D) of a zirconium-containing metal oxide)

[0154] 90 L of a mixed aqueous solution of 0.6 mol / L zirconium oxychloride and 0.03 mol / L yttrium chloride, and 68 L of a 1.9 mol / L sodium hydroxide aqueous solution were prepared. The above-mentioned mixed aqueous solution of zirconium oxychloride and yttrium chloride and the sodium hydroxide aqueous solution were simultaneously injected into a precipitation reactor pre-filled with 82 L of pure water. Simultaneous neutralization caused co-precipitation of zirconium oxychloride and yttrium chloride, yielding a first aqueous slurry of zirconium oxide and yttrium co-precipitate particles. This first aqueous slurry was filtered and washed, and then re-slurried with pure water to achieve a solid content of 11% by mass (calculated based on the conversion of zirconium oxide and yttrium oxide), yielding 60 L of a second aqueous slurry. The conductivity of this second aqueous slurry was 70 μS / cm. 4.2 kg of acetic acid (1.3 moles relative to the total molar amount of zirconium and yttrium in the above slurry) was added to the second aqueous slurry, and the mixture was hydrothermally treated at 190 °C for 3 hours to obtain a transparent aqueous dispersion. The transparent dispersion was washed and concentrated using an ultrafiltration membrane to obtain an aqueous dispersion (D) of zirconium-containing metal oxide with a content of 30% by mass. The zirconium-containing metal oxide is a solid solution containing 4.8 mol% yttrium.

[0155] (Example 5: Preparation of methanol dispersion (E) of zirconium-containing metal oxide)

[0156] The aqueous dispersion (D) of zirconium-containing metal oxide obtained above was concentrated using an ultrafiltration membrane. An equal amount of methanol as the filtrate was added to the concentrated dispersion. The concentration and methanol-based dilution of the dispersion were carried out continuously and simultaneously. Thus, while maintaining the content of zirconium-containing metal oxide in the dispersion at 30% by mass, the dispersion medium of the dispersion was replaced from water to methanol, resulting in a methanol dispersion (E) of zirconium-containing metal oxide with a content of 30% by mass.

[0157] Table 1 shows the pH of the aqueous or methanol dispersions of the zirconium-containing metal oxides obtained in Examples 1-5 and the particle size of the zirconium-containing metal oxides. Regarding pH, in the case of the methanol dispersion, the pH of the aqueous dispersion before ultrafiltration is shown.

[0158]

[0159] (Manufacturing Example 6: Preparation of Hard Coating Liquid)

[0160] Hydrolysis was performed for 48 hours by adding 52.3 g of methanol and 16.0 g of dilute hydrochloric acid (0.1N) dropwise to 69.7 g of γ-epoxypropoxypropyltrimethoxysilane. Then, 45.3 g of propylene glycol monomethyl ether, 115.1 g of a methanol dispersion (E) containing zirconium metal oxide, 1.40 g of tris(2,4-pentanedione)aluminum(III) as a curing catalyst, and 0.11 g of surfactant (manufactured by NEOS, trade name "Ftergent 222F") were added, and the mixture was stirred for 24 hours to prepare a hard coating solution.

[0161] <Example 1>

[0162] A 100.0 g aqueous dispersion (A) of zirconium-containing metal oxide (30% by mass) was mixed with 220.21 g of water, 79.79 g of waterborne polyurethane resin (manufactured by Nichika Chemical Co., Ltd., trade name "EVAFANOL HA-170") (37.6% by mass of non-volatile components), and 0.20 g of leveling agent (manufactured by DOW TORAY Co., Ltd., trade name "L-7604") to obtain a primer coating forming composition. The proportion of zirconium-containing metal oxide in the solid components of the primer coating forming composition is 50% by mass.

[0163] (Formation of the base coating)

[0164] Two commercially available plastic lens substrates (MR-8: manufactured by Mitsui Chemicals Co., Ltd., with a refractive index of 1.60; MR-7: manufactured by Mitsui Chemicals Co., Ltd., with a refractive index of 1.67) were prepared. The primer coating composition (15% by mass solids) described in Example 1 was applied to each lens substrate by dip-coating at a speed of 130 mm / min. The lens substrates coated with the primer coating composition were pre-cured at 90°C for 10 minutes, and then formally cured at 120°C for 2 hours, forming a primer coating with a thickness of 1 μm on the lens substrates. Additionally, a primer coating with a thickness of 3 μm was formed on a glass slide substrate using the same method as described above.

[0165] (Formation of primer layer + hard coating layer)

[0166] Two commercially available plastic lens substrates (MR-8: manufactured by Mitsui Chemicals Co., Ltd., with a refractive index of 1.60; MR-7: manufactured by Mitsui Chemicals Co., Ltd., with a refractive index of 1.67) were prepared. The primer coating forming composition (solid component concentration 15% by mass) described in Example 1 was applied to each lens substrate by dip-coating at a speed of 130 mm / min. The lens substrate coated with the primer coating forming composition was pre-cured by heating at 90°C for 10 minutes, forming a primer coating with a film thickness of 1 μm. The hard coating liquid described in Manufacturing Example 6 was then applied to the lens substrate coated with the primer coating forming composition by dip-coating at a speed of 130 mm / min. After pre-curing the lens substrate coated with the hard coating liquid by heating at 90°C for 10 minutes, it was then fully cured by heating at 120°C for 2 hours, forming a hard coating with a film thickness of 3 μm.

[0167] <Example 2>

[0168] A primer coating composition was obtained by using the same method as in Example 1, comprising 100.0 g of a methanol dispersion (B) of zirconium-containing metal oxide at a concentration of 30% by mass of zirconium-containing metal oxide. The proportion of zirconium-containing metal oxide in the solid components of the primer coating composition was 50% by mass.

[0169] The base coat and the base coat + hard coat were formed using the same method as in Example 1.

[0170] <Example 3>

[0171] A 100.0 g aqueous dispersion (A) of zirconium-containing metal oxide (30% by mass) was prepared relative to the concentration of zirconium-containing metal oxide. 220.21 g of water, 6.0 g of surfactant (manufactured by BYK-Chemie Japan, trade name "DISPERBYK-180"), 79.79 g of waterborne polyurethane resin (manufactured by Nichika Chemical Co., Ltd., trade name "EVAFANOL HA-170") with 37.6% by mass of non-volatile components, and 0.20 g of leveling agent (manufactured by DOW TORAY, trade name "L-7604") were added, and the mixture was stirred to obtain a primer coating composition. The proportion of zirconium-containing metal oxide in the solid components of the primer coating composition was 45% by mass.

[0172] The base coat and the base coat + hard coat were formed using the same method as in Example 1.

[0173] <Example 4>

[0174] A methanol dispersion (B) of zirconium-containing metal oxide (30% by mass) containing zirconium element was prepared by adding 216.17g of water, 63.83g of waterborne polyurethane resin (manufactured by Nichika Chemical Co., Ltd., trade name "EVAFANOL HA-170") containing 37.6% by mass of non-volatile components, and 0.20g of leveling agent (manufactured by DOW TORAY Co., Ltd., trade name "L-7604"), and the mixture was stirred to obtain a composition for forming a primer coating. The proportion of zirconium-containing metal oxide in the solid components of the primer coating forming composition was 60% by mass.

[0175] The base coat and the base coat + hard coat were formed using the same method as in Example 1.

[0176] <Example 5>

[0177] A 100.0 g aqueous dispersion (A) of zirconium-containing metal oxide (30% by mass) was mixed with 210.71 g of water, 89.29 g of aqueous polyurethane resin (manufactured by Daiichi Kogyo Pharmaceutical Co., Ltd., trade name "Superflex 170") (33.6% by mass of non-volatile components), and 0.20 g of leveling agent (manufactured by DOW TORAY Co., Ltd., trade name "L-7604") to obtain a primer coating forming composition. The proportion of zirconium-containing metal oxide in the solid components of the primer coating forming composition is 50% by mass.

[0178] The base coat and the base coat + hard coat were formed using the same method as in Example 1.

[0179] <Example 6>

[0180] A composition for forming a base coating was obtained by using 100.0 g of an aqueous dispersion (C) of zirconium-containing metal oxide at a concentration of 30% by mass, following the same method as in Example 1. The proportion of zirconium-containing metal oxide in the solid components of the composition for forming the base coating was 50% by mass.

[0181] The base coat and the base coat + hard coat were formed using the same method as in Example 1.

[0182] <Comparative Example 1>

[0183] For 100.0 g of an aqueous dispersion (D) of a zirconium-containing metal oxide with a concentration of 30% by mass, an attempt was made to prepare a composition for forming a base coat using the same method as in Example 1, but agglomerates were produced and the composition for forming a base coat could not be prepared.

[0184] The results of various physical property evaluations for Examples 1-6 and Comparative Example 1 are shown in Table 2.

[0185]

[0186] Based on the results in Table 2, it can be confirmed that by using a zirconium-containing metal oxide with a silicon content of less than 20 mol% relative to 100 mol% of zirconium in (A), an average particle size within a given range, and a pH of 8 to 11 for a 30 mol% aqueous dispersion, a composition capable of forming a base coating with high transparency and high refractive index can be obtained.

Claims

1. A composition for forming a base coating, comprising a zirconium-containing metal oxide (A) and an aqueous urethane resin (B), wherein, The average particle size of the zirconium-containing metal oxide (A), as determined by dynamic light scattering, is 1-20 nm. The pH of a 30% by mass aqueous dispersion of the zirconium-containing metal oxide (A) is 8-11. The content of silicon is less than 20 mol% relative to 100 mol% of zirconium in (A).

2. The composition for forming a base coating according to claim 1, wherein, The content of the zirconium-containing metal oxide (A) is 40 to 80% by mass relative to 100% by mass of the solid components in the composition for forming the base coating.

3. The composition for forming a base coating according to claim 1, wherein, The solid content of the aqueous urethane resin (B) is 20 to 60% by mass relative to 100% by mass of the solid content in the composition for forming the base coating.

4. The composition for forming a base coating according to any one of claims 1 to 3, wherein, The composition for forming the base coating is used for lens applications.

5. A lens coated with the composition for forming an undercoat layer as described in any one of claims 1 to 3.

6. A method for manufacturing a composition for forming a primer coating, the method comprising: The process of mixing a zirconium-containing metal oxide (A) with an aqueous urethane resin (B) The average particle size of the zirconium-containing metal oxide (A), as determined by dynamic light scattering, is 1–20 nm, and the pH of the 30% by mass aqueous dispersion is 8–11.

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