Liquid composition, hard coat layer, eyeglass lens

Abstract

The present invention addresses the problem of providing a liquid composition capable of forming a hard coat layer having excellent toughness. A liquid composition according to the present invention includes a polymer obtained by performing cationic polymerization of cation polymerizable groups in a compound having cationic polymerizable groups selected from the groups consisting of epoxy groups and oxetanyl groups.

Description

[Technical Field]

[0001] This disclosure relates to a liquid composition, a hard coat layer, and an eyeglass lens. [Background technology]

[0002] An epoxy resin molded article is known, which is formed by curing a composition comprising at least epoxy resin and inorganic oxide particles (for example, claim 1 of Patent Document 1). [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2004-250521 [Overview of the project]

[0004] This disclosure relates to a liquid composition comprising a polymer obtained by cationic polymerization of a cationic polymerizable group in a compound having a cationic polymerizable group selected from the group consisting of epoxy groups and oxetanyl groups. [Brief explanation of the drawing]

[0005] [Figure 1] This is a cross-section of an eyeglass lens. [Figure 2] This is a diagram showing the scratch marks used in the toughness evaluation of Example 1. [Figure 3] This is a diagram showing the scratch marks used in the toughness evaluation of Example 2. [Figure 4] This is a diagram showing the scratch marks in the toughness evaluation of Comparative Example 1. [Figure 5] This is a diagram showing the scratch marks in the toughness evaluation of Comparative Example 2. [Modes for carrying out the invention]

[0006] The liquid compositions of this disclosure will be described in detail below. The hard coat layer of eyeglass lenses is required to have excellent toughness. The layer formed using the liquid composition of this disclosure can be used as a hard coat layer having the above-mentioned properties. In this specification, "~" is used to mean that the numbers before and after it are included as the lower and upper limits, respectively. In this specification, "boiling point" means the boiling point at 1 atmosphere. In this specification, the solid content of a liquid composition refers to the components that constitute the film (hard coat layer) after the curing process, and does not include the solvent. Furthermore, any component that constitutes the film is included in the calculation of solid content, even if it is liquid at room temperature and pressure (25°C, 101.3 kPa). The solid content also includes components that undergo chemical changes during the hard coat layer formation process.

[0007] The liquid composition will be described in detail below.

[0008] <Liquid composition> The liquid composition of this disclosure comprises a polymer (hereinafter also referred to as "specific polymer") obtained by cationic polymerization of a cationic polymerizable group (hereinafter also referred to as "specific cationic polymerizable group") selected from the group consisting of epoxy groups and oxetanyl groups (hereinafter also referred to as "specific cationic polymerizable group") in a compound (hereinafter also referred to as "compound A").

[0009] A liquid composition means that the composition itself is in a liquid state. To be a liquid composition, the specific polymer itself may be liquid, or the composition obtained by adding a liquid medium (e.g., a liquid compound, organic solvent, and water) to the specific polymer may be made liquid. Note that "liquid" means being in a liquid state at 1 atmosphere and 25°C. In other words, the liquid composition may consist solely of a specific polymer, or it may be a liquid composition containing a specific polymer and other components other than the specific polymer (in particular, a liquid medium).

[0010] (Specific polymers) The specific polymer is a polymer obtained by cationic polymerization of a specific cationic polymerizable group in compound A.

[0011] The specific polymer preferably has a specific cationic polymerizable group. As the number of the specific cationic polymerizable groups contained in the specific polymer, a plurality are preferred. The specific polymer is a polymer obtained by cationically polymerizing Compound A, and is a so-called prepolymer. It is preferable to cationically polymerize Compound A so that the specific cationic polymerizable group remains without completely consuming the specific cationic polymerizable group possessed by Compound A through cationic polymerization, thereby obtaining a specific polymer having a specific cationic polymerizable group.

[0012] The specific polymer is preferably obtained by cationically polymerizing the cationic polymerizable group in Compound A in a solution containing a protic solvent. That is, when cationically polymerizing Compound A, it is preferable to carry out cationic polymerization in a solvent containing a protic solvent, and more preferably to carry out cationic polymerization in a solution containing a solvent selected from the group consisting of water and an alcohol solvent.

[0013] The specific polymer may be used alone or in combination of two or more. The content of the specific polymer with respect to the total solid content of the liquid composition is not particularly limited and can be adjusted as appropriate.

[0014] (Inorganic particles) The liquid composition may contain inorganic particles. When the liquid composition contains inorganic particles, the resulting film can have a higher hardness. The inorganic particles are particles different from Compound A described later.

[0015] Examples of the inorganic particles include one or more metal particles selected from the group consisting of Ti, Zr, Si, Al, Sn, Sb, Ta, Ce, La, Fe, Zn, W, and In, and composite particles thereof. One or more metal particles selected from the group consisting of Ti, Zr, Si, Al, and Sn, and composite particles thereof are preferred. The composite particles are particles of a metal containing two or more metals (metal atoms). Also, Si (silicon) is regarded as a metal.

[0016] As the inorganic particles, inorganic oxide particles are preferred. The inorganic oxide particles can function as a cationic polymerization initiator. Although the details of the reason why the inorganic oxide particles can function as a cationic polymerization initiator are unclear, it is considered that proton cations are supplied from the surface of the inorganic oxide particles, and cationic polymerization can proceed by these proton cations. The inorganic oxide particles can function as a cationic polymerization initiator when cationically polymerizing compound A, similar to a cationic polymerization initiator. In addition, the inorganic oxide particles can exhibit the same effect (hardening of the film to a high degree) as a cationic polymerization initiator. Examples of the inorganic oxide particles include one or more metal oxide particles selected from the group consisting of Ti, Zr, Si, Al, Sn, Sb, Ta, Ce, La, Fe, Zn, W, and In, and composite oxide particles thereof. The composite oxide particles are particles of an oxide containing two or more metals (metal atoms). As the inorganic oxide particles, one or more metal oxide particles selected from the group consisting of SiO2 (silicon oxide), Al2O3 (aluminum oxide), SnO2 (tin oxide), ZrO2 (zirconium oxide), and TiO2 (titanium oxide) are preferred, and one or more metal oxide particles selected from the group consisting of SiO2 and ZrO2 are more preferred. Examples of the inorganic oxide particles include sols in which one or more inorganic oxide particles selected from the group consisting of titanium oxide, zirconium oxide, silicon oxide, tin oxide, aluminum oxide, and composite oxides thereof are dispersed in water or an organic solvent. Further, the inorganic oxide particles may be core-shell type particles.

[0017] The inorganic particles may be surface-treated. Examples of the surface treatment include introduction of various functional groups and treatment using known surface modifiers.

[0018] The average particle size of the inorganic particles is often in the range of 0.5 to 70 nm, and preferably 1 to 50 nm. One method for measuring the average particle size is to use a laser-based particle size analyzer. Alternatively, the average particle size can be determined by measuring the diameters of 20 or more inorganic particles using a transmission electron microscope and then taking their arithmetic mean. If the inorganic particles are not perfectly round, the major axis is used as the diameter.

[0019] Inorganic particles may be used individually or in combination of two or more types. The inorganic particle content is preferably 10 to 70% by mass, more preferably 20 to 65% by mass, and even more preferably 30 to 60% by mass, relative to the total solid content of the liquid composition.

[0020] (Protic solvent) The liquid composition may contain a protic solvent. The protic solvent preferably includes a solvent selected from the group consisting of water and alcohol solvents. The protic solvent used in the cationic polymerization step in the method for producing the liquid composition described later may be the same as or different from the one used in the method.

[0021] Alcohol solvents are solvents that have one or more hydroxyl groups. As the alcohol solvent, primary to tertiary alcohol solvents are preferred, primary to secondary alcohol solvents are more preferred due to their high performance as chain transfer agents, and primary alcohol solvents are even more preferred. Examples of alcoholic solvents include methanol, ethanol, 1-propanol, isopropanol, and 1-butanol.

[0022] Alcohol solvents may be used individually or in combination of two or more types. The alcohol solvent content is preferably 10 to 70% by mass, more preferably 15 to 65% by mass, and even more preferably 20 to 60% by mass, based on the total mass of the liquid composition.

[0023] (Compound B) The liquid composition may contain compound B. Compound B is one or more compounds selected from the group consisting of curing agents and polymerization initiators.

[0024] Examples of curing agents include amine-based curing agents (e.g., jER Cure ST-11 manufactured by Mitsubishi Chemical Corporation) and acid anhydrides (e.g., jER Cure YH306 manufactured by Mitsubishi Chemical Corporation).

[0025] Examples of polymerization initiators include photopolymerization initiators and thermal polymerization initiators, with thermal polymerization initiators being preferred. Furthermore, the polymerization initiator may be any of radical polymerization initiators, cationic polymerization initiators, or anionic polymerization initiators, with cationic polymerization initiators being preferred. If the liquid composition contains a cationic polymerization initiator, the cationic polymerization initiator may be the same as the one used when cationic polymerization of compound A. In other words, the cationic polymerization initiator used when cationic polymerization of compound A may remain in the liquid composition, and a polymerization initiator different from the above-mentioned cationic polymerization initiator may be newly added to the liquid composition.

[0026] Examples of polymerization initiators include: Cyracure UVI-6992 and UVI-6974 (manufactured by Dow Chemical Japan); Adeka Optomer SP150, SP152, SP170 and SP172 (manufactured by ADEKA); IRGACURE 250 (manufactured by Ciba Specialty Chemicals); CI-5102 and CI-2855 (manufactured by Nippon Soda Co., Ltd.); and Sun-Aid SI-60L, SI-80L, and SI-10. 0L, SI-110L and SI-180L (manufactured by Sanshin Chemical Industry Co., Ltd.); CPI-100P and CPI-100A (manufactured by Sunapro Co., Ltd.); thermal cationic polymerization initiators such as WPI-069, WPI-113, WPI-116, WPI-041, WPI-044, WPI-054, WPI-055, WPAG-281, WPAG-567 and WPAG-596 (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.); Omnirad Examples include photoradical polymerization initiators such as 127, 184, 907, 651, 1700, 1800, 819, 369 and TPO (manufactured by IGM Resins BV); DAROCUR 1173 (manufactured by Sigma-Aldrich); Ezacure KIP 150 and TZT (manufactured by Nippon Siber Hegner Co., Ltd.); and Kayacure BMS and Kayacure DMBI (manufactured by Nippon Kayaku Co., Ltd.). As cationic polymerization initiators, SP150 (manufactured by ADEKA Corporation), a phosphorus-based photopolymerization initiator, or SI-100L (manufactured by Sanshin Chemical Industry Co., Ltd.), an antimony-based thermal polymerization initiator, are preferred. Furthermore, inorganic particles with low catalytic activity, as described above, may be used as cationic polymerization initiators because they allow for easier control of the reaction. Acid groups that may be present on the surface of inorganic particles can function as cationic polymerization initiators.

[0027] Compound B may be used alone or in combination of two or more compounds. The content of compound B is preferably 0.001 to 5% by mass, and more preferably 0.01 to 1% by mass, relative to the total solid content of the liquid composition.

[0028] (Surfactants) The liquid composition may contain a surfactant. Examples of surfactants include silicone compounds such as silicone oil (e.g., DOWSIL series from DOW Corporation). Surfactants may be used individually or in combination of two or more types. The surfactant content is preferably 0.001 to 5% by mass, and more preferably 0.01 to 0.5% by mass, relative to the total solid content of the liquid composition.

[0029] (Sensitizer) The liquid composition may contain a sensitizer. Examples of sensitizers include the Anthracure series manufactured by Kawasaki Chemical Industries, Ltd. Sensitizers may be used individually or in combination of two or more. The sensitizer content is preferably 0.001 to 5% by mass, and more preferably 0.05 to 2% by mass, relative to the total solid content of the liquid composition.

[0030] (UV absorber) The liquid composition may contain an ultraviolet absorber. Examples of ultraviolet absorbers include triazine compounds and benzotriazole compounds. UV absorbers may be used individually or in combination of two or more types. The amount of ultraviolet absorber is preferably 0.01 to 5% by mass, and more preferably 0.1 to 3% by mass, relative to the total solid content of the liquid composition.

[0031] (Other ingredients) The liquid composition may contain other components in addition to the above-mentioned components. Other components include, for example, compound A described later, other solvents other than protic solvents, other chain transfer agents other than protic solvents, and compounds having one or two specific cationic polymerizable groups from the viewpoint of controlling the crosslinking density. Other ingredients may be used individually or in combination of two or more.

[0032] Other preferred solvents include organic solvents that can be mixed with water or alcoholic solvents in any ratio. Examples of organic solvents include ketone solvents, ether solvents, ester solvents, amide solvents, sulfone solvents, and sulfoxide solvents. Examples of ketone solvents include methyl ethyl ketone, methyl butyl ketone, and propylene glycol monomethyl ether acetate.

[0033] Other chain transfer agents include, for example, thiol compounds, thioether compounds, thioester compounds, and phosphate ester compounds. Specifically, examples include the Karens® series (manufactured by Showa Denko Corporation, such as PE1, BD1, NR1, and TPMB). Other chain transfer agents include epoxy compounds. Epoxy compounds act as chain transfer agents for oxetanyl groups and can also be copolymerized.

[0034] Examples of compounds having one or two specific cationic polymerizable groups include the Aronoxetane® series (manufactured by Toagosei Co., Ltd., e.g., OXT-101, OXT-212, OXT-121, and OXT-221) and the Denacol series (manufactured by Nagase ChemteX Corporation, e.g., EX-121, EX-146, EX-171, EX-810, and EX-211).

[0035] The viscosity of the liquid composition (at 20°C) can be adjusted as appropriate. The viscosity of the liquid composition is often 100,000 cP or less, but may also be 10,000 cP or less, or even 1,000 cP or less. The lower limit is often 0.5 cP or higher. The viscosity described above can be measured using a known measuring device (for example, a cone-plate viscometer).

[0036] The method for producing the liquid composition will be described in detail below.

[0037] <Method for producing a liquid composition> The method for producing the liquid composition is not particularly limited, as long as it involves cationic polymerization of a specific cationic polymerizable group in compound A. The method for producing the liquid composition preferably includes a cationic polymerization step in which a specific cationic polymerizable group of compound A is cationically polymerized in a solution containing a protic solvent. By cationic polymerization of compound A in a solution containing a protic solvent, the hydroxyl groups of the protic solvent act as chain transfer agents, allowing control of the cationic polymerization reaction of compound A and preventing gelation. Furthermore, the specific polymer obtained by the above method tends to possess specific cationic polymerizable groups. The following describes in detail the method for producing a liquid composition, using the cationic polymerization process using the above-mentioned protic solvent as an example. Regarding protic solvents, please refer to the information provided above.

[0038] (Cationic polymerization process) The cationic polymerization process involves cationic polymerization of specific cationic polymerizable groups of compound A in a solution containing a protic solvent. By performing this process, a specific polymer can be synthesized.

[0039] Examples of methods for cationic polymerization of compound A include known cationic polymerization methods, and a method using a specific polymer synthesis composition described later is preferred. A specific polymer synthesis composition can be produced, for example, by mixing various components that may be included in the specific polymer synthesis composition. When mixing, the various components that may be included in the specific polymer synthesis composition may be added in separate portions or all at once. When adding in separate portions, the same components may be added in separate portions, or different components may be added in separate portions. One method of mixing is, for example, using a known agitator.

[0040] When performing cationic polymerization, heating is preferable to accelerate the polymerization reaction (especially when using compound A, which has an oxetanyl group). The heating method is not particularly limited and includes known methods. The heating temperature can be appropriately adjusted depending on the solvent and heating conditions that may be included in the specific polymer synthesis composition. For example, it is often between 40 and 120°C. The heating time for the heat treatment can be appropriately adjusted depending on the solvent and heating conditions that may be included in the specific polymer synthesis composition. For example, it is often between 10 minutes and 7 hours. The pressure used during heating may be atmospheric pressure, reduced pressure, or pressurized pressure. Furthermore, heating may be carried out in a sealed or reflux state.

[0041] -Composition for specific polymer synthesis- The composition for specific polymer synthesis is a composition used in the cationic polymerization step described above. The composition for specific polymer synthesis preferably comprises compound A, a solution containing a protic solvent, and a cationic polymerization initiator or inorganic particles, and more preferably consists substantially only of compound A, a protic solvent, and a cationic polymerization initiator or inorganic particles. Specifically, the total content of compound A, the protic solvent, and the cationic polymerization initiator or inorganic particles is preferably 80% by mass or more, more preferably 90% by mass or more, and even more preferably 95% by mass or more, based on the total mass of the composition for specific polymer synthesis. The upper limit is preferably 100% by mass or less, based on the total mass of the composition for specific polymer synthesis. The above-mentioned protic solvent, cationic polymerization initiator, and inorganic particles are as described above. The inorganic particles described above may remain in some form and be included in the liquid composition. The cationic polymerization initiator described above may also be a cationic polymerization initiator for compound B, which may remain in some form and be included in the liquid composition.

[0042] The composition for specific polymer synthesis preferably contains compound A. Compound A is a compound having a specific cationic polymerizable group.

[0043] The number of specific cationic polymerizable groups in compound A is one or more, preferably two or more, more preferably three or more, and even more preferably four or more. Compound A may have other functional groups in addition to the specific cationic polymerizable group. Examples of other functional groups include cationic polymerizable groups other than the specific cationic polymerizable group, acryloyl groups, methacryloyl groups, vinyl groups, and ethylenically unsaturated groups such as styryl groups.

[0044] Compound A is preferably silsesquioxane or a derivative thereof. Silsesquioxane or its derivatives are silane compounds having a basic skeleton represented by formula (Q) obtained by hydrolysis of trifunctional silane compounds such as alkoxysilanes, chlorosilanes, and silanols. Examples of structures of silsesquioxane or its derivatives include irregular forms such as random structures, ladder structures, cage-type (fully condensed cage-type) structures, and incomplete cage-type structures (partially cleaved cage-type structures in which some silicon atoms are missing from the cage-type structure, and structures in which some silicon-oxygen bonds of the cage-type structure are broken).

[0045] R b -SiO 3 / 2 (Q) In formula (Q), R b This represents a monovalent organic group. However, silane compounds having the basic skeleton represented by formula (Q) have a specific cationic polymerizable group.

[0046] Examples of the monovalent organic groups mentioned above include specific cationic polymerizable groups, as well as ethylenically unsaturated groups such as acryloyl groups, methacryloyl groups, vinyl groups, and styryl groups, with specific cationic polymerizable groups being preferred. A silane compound having a basic skeleton represented by formula (Q) has specific cationic polymerizable groups, preferably having three or more specific cationic polymerizable groups, and more preferably having four or more specific cationic polymerizable groups.

[0047] The average particle size of silsesquioxane or its derivatives is often 0.5 to 200 nm, and preferably 1 to 50 nm. One example of a method for measuring the average particle size is the method for measuring the average particle size of inorganic particles, which will be described later.

[0048] Examples of compound A include silsesquioxane or its derivatives, such as the SQ series (manufactured by Toagosei Co., Ltd., e.g., OX-SQ TX-100, OX-SQ SI-20, OX-SQ HDX, AC-SQ series and MAC-SQ series); and, other than silsesquioxane and its derivatives, the Showfree® series (manufactured by Showa Denko Corporation, e.g., PETG, CDMDG and BATG); the Denacol series (manufactured by Nagase ChemteX Corporation, e.g., EX-614B, EX-313, EX-512, EX-321 and EX-321L); and KR-470 (manufactured by Shin-Etsu Chemical Co., Ltd.).

[0049] Compound A may be used alone or in combination of two or more compounds. From the viewpoint of preventing gelation, the content of compound A is preferably 5 to 60% by mass, more preferably 10 to 50% by mass, and even more preferably 15 to 40% by mass, relative to the total solid content of the specific polymer synthesis composition.

[0050] (Mixing process) The method for producing the liquid composition may also preferably include a mixing step after the cationic polymerization step. The mixing step is the process of mixing various components that the liquid composition may contain. A preferred mixing step is to mix the liquid composition obtained in the cationic polymerization step with compound B. Compound B is as described above. One example of the above mixing method is a method of mixing various components of a specific polymer synthesis composition.

[0051] (Other processes) The method for producing the liquid composition may include other steps in addition to the steps described above. Other processes include, for example, solvent removal and filtration.

[0052] The solvent removal step is a step in which the solvent is removed from the liquid composition. The solvent removal step may be performed before or after each step, and it is preferable that the step be performed after the cationic polymerization step and before the mixing step to remove the protic solvent from the liquid composition.

[0053] The liquid composition is suitably used as a composition for forming a hard coat layer on a substrate. When used as a composition for forming the hard coat layer, the liquid composition preferably contains a specific polymer, inorganic particles, an alcohol solvent, and compound B. Examples of substrates include plastic substrates such as plastic eyeglass lens substrates and plastic films. The following describes in detail one embodiment in which the above liquid composition is applied to a plastic spectacle lens substrate.

[0054] <Eyeglass Lenses> The liquid composition is suitably used in the manufacture of eyeglass lenses. Examples of the above-mentioned eyeglass lens include an eyeglass lens substrate (for example, a plastic eyeglass lens substrate) and a film (hard coat layer) formed using the above-mentioned liquid composition, which is disposed on the eyeglass lens substrate. Figure 1 is a cross-sectional view of one embodiment of an eyeglass lens. The spectacle lens 10 shown in Figure 1 includes a plastic spectacle lens substrate 12 and a hard coat layer 14 disposed on both sides of the plastic spectacle lens substrate 12. The hard coat layer 14 is a layer formed using the liquid composition described above. In Figure 1, the hard coat layer 14 is positioned in direct contact with the plastic spectacle lens substrate 12, but other layers (e.g., a primer layer) may be placed between the plastic spectacle lens substrate 12 and the hard coat layer 14. In other words, the hard coat layer 14 may be placed directly on the plastic spectacle lens substrate 12, or it may be placed indirectly on the plastic spectacle lens substrate 12 via other layers. Furthermore, although the hard coat layer 14 is arranged on both sides of the plastic spectacle lens substrate 12 in Figure 1, the hard coat layer 14 may be arranged on only one side of the plastic spectacle lens substrate 12. The following describes in detail each component included in the eyeglass lens 10.

[0055] (Plastic eyeglass lens base material) Examples of plastic spectacle lens substrates include finished lenses, which are optically finished on both convex and concave surfaces and molded to the desired prescription. Examples of plastics (e.g., resins) that make up the base material of plastic eyeglass lenses include acrylic resins, methacrylic resins, thiourethane resins, allyl resins, episulfide resins, polycarbonate resins, polyurethane resins, polyester resins, polystyrene resins, polyethersulfone resins, poly-4-methylpentene-1 resins, diethylene glycol bisallyl carbonate resins (e.g., CR-39), and polyvinyl chloride resins.

[0056] The thickness of the base material for plastic eyeglass lenses is often between 1 and 30 mm for ease of handling. The refractive index of plastic eyeglass lens substrates is often between 1.60 and 1.74. The plastic spectacle lens base material is preferably translucent and may be either transparent or opaque. It may also be colored.

[0057] (Hard coat layer) The hard coat layer is a layer placed on the plastic spectacle lens substrate and provides scratch resistance to the plastic spectacle lens substrate. The hard coat layer is a layer formed using the liquid composition described above.

[0058] One method for forming the hard coat layer is to apply the above-mentioned liquid composition onto a plastic spectacle lens substrate to form a coating film, and then perform a curing treatment such as heat treatment or light irradiation on the coating film. Alternatively, a drying treatment such as heat treatment may be performed after the coating film has been formed.

[0059] Methods for applying a liquid composition onto a plastic spectacle lens substrate include, for example, known methods such as dipping coating, spin coating, spray coating, inkjet coating, and flow coating. For example, when using the dipping coating method, a plastic spectacle lens substrate is immersed in a liquid composition, and then the plastic spectacle lens substrate is removed and dried to form a coating film of a predetermined thickness on the plastic spectacle lens substrate. The film thickness of the coating formed on the plastic spectacle lens substrate can be appropriately selected to match the film thickness of the hard coat layer.

[0060] The conditions for heat treatment and light irradiation treatment can be appropriately selected to suit the type of polymerization initiator. The heating temperature is often between 40 and 120°C. Examples of light used in light irradiation processing include ultraviolet light and visible light. Examples of light sources include high-pressure mercury lamps. The cumulative light intensity during light irradiation should be 100-3000 mJ / cm² in terms of productivity and coating film curing properties. 2 In many cases, the reading is 100-1500 mJ / cm². 2 It is preferable.

[0061] The thickness of the hard coat layer is often 1 μm or more, preferably 4 μm or more, and more preferably 10 μm or more. The upper limit is often 50 μm or less. The above film thickness refers to the average film thickness. Methods for measuring the average film thickness include, for example, measuring the film thickness at five arbitrary points in the hard coat layer and calculating the arithmetic mean, and using an optical film thickness gauge.

[0062] (Primer layer) The primer layer is a layer placed between the substrate and the hard coat layer, and its purpose is to improve the adhesion of the hard coat layer to the substrate. Examples of materials that make up the primer layer include known materials such as resins. Examples of resins include urethane resins, epoxy resins, phenolic resins, polyimide resins, polyester resins, bismaleimide resins, and polyolefin resins.

[0063] Examples of methods for forming the primer layer include known methods. For example, one method involves applying a primer layer-forming composition containing a predetermined resin onto a plastic spectacle lens substrate and then performing a curing treatment as necessary.

[0064] The thickness of the primer layer is often between 0.3 and 2 μm. The above film thickness refers to the average film thickness. One method for measuring the average film thickness is to measure the film thickness at five arbitrary points in the primer layer and then calculate the arithmetic mean of these measurements.

[0065] (Anti-reflective film) The plastic spectacle lens may further include an anti-reflective coating disposed on the hard coat layer. An anti-reflective coating is a layer that prevents the reflection of incident light. When a plastic eyeglass lens has an anti-reflective coating, it can have low reflectivity (broadband low reflectivity) across the entire visible light region with wavelengths of 400 to 700 nm.

[0066] The anti-reflective coating may have either a single-layer or multi-layer structure. As the anti-reflective coating, an inorganic anti-reflective coating is preferred. An inorganic anti-reflective coating is an anti-reflective coating composed of an inorganic compound. When the anti-reflective coating has a multilayer structure, a structure in which low refractive index layers and high refractive index layers are alternately stacked is preferred. Examples of materials that make up the high refractive index layers include metal oxides such as titanium, zircon, aluminum, niobium, tantalum, and lanthanum. Examples of materials that make up the low refractive index layers include silica. Examples of methods for manufacturing anti-reflective coatings include dry methods such as vacuum deposition, sputtering, ion plating, ion beam-assisted deposition, and CVD. [Examples]

[0067] The liquid compositions will be described in more detail below with reference to examples and comparative examples, but this embodiment is not limited in any way by these examples.

[0068] <Liquid compositions X1-X2, comparative compositions x1-x2> Each liquid composition was prepared according to the following procedure.

[0069] (Liquid composition X1) Compound A (manufactured by Toagosei Co., Ltd.: OX-SQ TX-100) (100.00 g), which has three or more oxetanyl groups, and colloidal silica (manufactured by JGC Catalysts & Chemicals Co., Ltd.: OSCAL-1432E, isopropanol dispersion, solid content 30% by mass) (326.80 g) were added to a glass container equipped with a stirring bar to form a mixture. The mixture was heated and stirred on a hot plate for 5 hours while boiling. The temperature of the mixture was 83°C, the boiling point of isopropanol. The glass container was sealed with a lid, and the isopropanol condensed on the inner wall of the container and refluxed. After heating, the mixture was cooled to room temperature overnight. Then, butyl cellosolve (161.11 g) was added as a solvent for film formation, and isopropanol was removed by distillation in a 40°C warm bath under reduced pressure using a rotary evaporator for 2 hours to obtain liquid composition X1.

[0070] (Liquid composition X2) Compound A (Showa Denko: Showfree PETG) (4.00 g), which has four epoxy groups, colloidal zirconia (Nissan Chemical: NanoYouth OZ-S30K, methyl ethyl ketone dispersion, 30% solids by mass) (13.37 g), and methanol (6.49 g) were added to a glass container equipped with a stirring bar to form a mixture. The mixture was heated and stirred on a hot plate for 5 hours while boiling. The temperature of the mixture was 65°C, the boiling point of methanol. The glass container was sealed with a lid, and methanol condensed on the inner wall of the container and refluxed. After heating, the mixture was cooled to room temperature overnight. Then, the container lid was removed, and the mixture was heated again until boiling, and stirred for 30 minutes to remove methanol, thereby obtaining liquid composition X2.

[0071] (composition for comparison x1) Compound A (manufactured by Toagosei Co., Ltd.: OX-SQ TX-100) (5.00 g), which has three or more oxetanyl groups, and colloidal silica (manufactured by JGC Catalysts & Chemicals Co., Ltd.: OSCAL-1432E, isopropanol dispersion, solid content 30% by mass) (16.34 g) were added to a glass container equipped with a stirring bar to obtain comparative composition x1. Furthermore, no specific polymer was detected in comparative composition x1 (the cationic polymerization reaction of compound A had not proceeded).

[0072] (composition for comparison x2) A comparative composition x2 was obtained by adding a compound having four epoxy groups (Showa Denko: Showfree PETG) (4.00 g) and colloidal zirconia (Nissan Chemical: NanoYouth OZ-S30K, methyl ethyl ketone dispersion, solid content 30% by mass) (13.37 g) to a glass container equipped with a stirring bar. Furthermore, no specific polymer was detected in comparative composition x2 (the cationic polymerization reaction of compound A did not proceed).

[0073] <Viscosity changes during the preparation of liquid compositions> The viscosity changes of each liquid composition during preparation were observed. Liquid compositions X1 and X2 had a higher viscosity than the mixture before the cationic polymerization reaction proceeded (before heat treatment). This was presumed to be because the heat treatment caused the inorganic particles (colloidal silica or colloidal zirconia) to function as cationic polymerization initiators, and compound A underwent cationic polymerization to synthesize a specific polymer.

[0074] <Viscosity of each composition> The viscosity (cP) of the obtained liquid composition X1 was measured at 20°C using a cone-plate viscometer. The viscosity (20°C) of liquid composition X1 was 157 cP.

[0075] <Liquid compositions Y1-Y2, comparative liquid compositions y1-y2> Each liquid composition was prepared according to the following procedure.

[0076] (Liquid composition Y1) Liquid composition X1 (2.00 g), a 22% by mass isopropanol solution of polyether-modified silicone (manufactured by Toray Dow Corning: DOWSIL L-7001) (0.05 g) as a leveling agent, and a thermal cationic polymerization initiator (manufactured by Sanshin Chemical Industry Co., Ltd.: San-Aid SI-100L) (0.02 g) were added to a glass container equipped with a stirring bar and mixed to obtain liquid composition Y1.

[0077] Liquid composition Y2 and comparative compositions y1 to y2 were obtained by mixing the various components and their contents as shown in Table 1, in the same manner as liquid composition Y2.

[0078] The numerical units in the columns for each component in the table below are parts by mass.

[0079] [Table 1]

[0080] <Example 1> A plastic spectacle lens substrate made of a thiourethane resin with a refractive index of 1.60 (manufactured by Nikon Essilor, Nikon Lite 3AS, size 75φ, center thickness 2 mm) was coated with the liquid composition Y1 on its convex surface using a spin coater, and then cured by heating at 100 °C for 40 minutes to obtain a plastic substrate 1 with a hard coat layer.

[0081] <Example 2> A plastic substrate 2 with a hard coat layer was obtained in the same procedure as in Example 1, except that the liquid composition Y1 was changed to the liquid composition Y2 and heated at 120 °C for 60 minutes.

[0082] For Comparative Examples 1 and 2, plastic substrates 3 to 4 with hard coat layers were obtained by referring to Examples 1 and 2, except that the compositions and curing conditions shown in the following table were changed.

[0083] <Toughness> Using a friction and wear tester (manufactured by Shinato Scientific Co., Ltd.: Tribogear TYPE40), a sapphire scratching needle with a tip radius of 0.05 mm and an apex angle of 60° (manufactured by Shinato Scientific Co., Ltd.: BH0001-06) was vertically contacted with the convex surface of each plastic substrate with a hard coat layer. While applying a vertical load of 300 g to the scratching needle, it was moved once at a speed of 600 mm / min for a length of 20 mm. Using a digital microscope (manufactured by Keyence Corporation: VHX-1000), the scratching needle marks on the convex surface of each plastic substrate with a hard coat layer were observed. Also, the scratching needle marks on the convex surface during the toughness evaluation of each example and each comparative example are shown in Figures 2 to 5. Toughness was evaluated according to the following evaluation criteria. A: Few or no cracks B: Many cracks C: The convex surface of the substrate was broken into pieces.

[0084] <Appearance of the hard coat layer> The hard coat layer of each plastic substrate with a hard coat layer was visually observed.

[0085] <FT-IR measurement> The hard coat layers of the obtained plastic substrates 1 to 4 with each hard coat layer were subjected to FT-IR measurement using a Fourier transform infrared spectrophotometer (JASCO FT / IR-6600, using diamond ATR). In Example 1 compared with Comparative Example 1, the absorption of the oxetanyl group near 980 cm -1 was less, and the absorption of the hydroxyl group near 3388 cm -1 was more. The difference in these absorption intensities suggested the formation of a polyether chain due to the polymerization of the oxetanyl group. Also, in Example 2 compared with Comparative Example 2, the absorption of the epoxy group near 980 cm -1 was less, and the absorption of the hydroxyl group near 3410 cm -1 was more. In Example 2, new absorption bands appeared near 1455 cm -1 and near 1195 cm -1 , and these were derived from the CH bonds of the polyether structure.

[0086] The film thickness of the hard coat layer in the table is the value measured by an optical film thickness meter.

[0087]

Table 2

[0088] As shown in Table 2, it was confirmed that a hard coat film excellent in toughness can be obtained by using the liquid composition of the present embodiment. While linear scratch marks occurred in the hard coat layer of the example, the hard coat layer of the comparative example was broken into pieces. That is, as also shown in the results of the FT-IR measurement, the hard coat layer using the specific polymer produced by prepolymerization of Compound A as in the example is presumed to have a higher crosslink density in the hard coat layer, and as a result, the hardness and toughness were improved.

Explanation of Signs

[0089] 10 Eyeglass lens 12 Plastic eyeglass lens substrate 14 Hard coat layer

Claims

1. A liquid composition comprising a polymer obtained by cationic polymerization of a cationic polymerizable group selected from the group consisting of epoxy groups and oxetanyl groups in a compound having such cationic polymerizable group, The viscosity of the liquid composition at 20°C is 1000 cP or less. A liquid composition in which the compound having the cationic polymerizable group is silsesquioxane or a derivative thereof.

2. The liquid composition according to claim 1, wherein the compound having the cationic polymerizable group has three or more of the cationic polymerizable groups.

3. The liquid composition according to claim 1 or 2, wherein the polymer has the cationic polymerizable group.

4. Furthermore, it contains inorganic particles, The inorganic particles are SiO ２ Al ２ O ３ , SnO ２ , ZrO ２ and TiO ２ The liquid composition according to claim 1 or 2, comprising one or more metal oxide particles selected from the group consisting of the following.

5. A hard coat layer formed using the liquid composition according to claim 1 or 2.

6. An eyeglass lens comprising an eyeglass lens substrate and a hard coat layer according to claim 5, disposed on the eyeglass lens substrate.

7. A method for producing a liquid composition according to claim 1 or 2, A method for producing a liquid composition, wherein the polymer is obtained by cationic polymerization of the cationic polymerizable group in the compound having the cationic polymerizable group in a solution containing a protic solvent.

8. The method for producing a liquid composition according to claim 7, wherein the protic solvent comprises a solvent selected from the group consisting of water and alcohol solvents.

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